[PATCH v5 00/16] x86-64: Stack protector and percpu improvements

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* [PATCH v5 00/16] x86-64: Stack protector and percpu improvements
@ 2024-11-05 15:57 Brian Gerst
  2024-11-05 15:57 ` [PATCH v5 01/16] x86/stackprotector: Work around strict Clang TLS symbol requirements Brian Gerst
                   ` (17 more replies)
  0 siblings, 18 replies; 67+ messages in thread
From: Brian Gerst @ 2024-11-05 15:57 UTC (permalink / raw)
  To: linux-kernel, x86
  Cc: Ingo Molnar, H . Peter Anvin, Thomas Gleixner, Borislav Petkov,
	Ard Biesheuvel, Uros Bizjak, Brian Gerst

Currently, x86-64 uses an unusual percpu layout, where the percpu section
is linked at absolute address 0.  The reason behind this is that older GCC
versions placed the stack protector (if enabled) at a fixed offset from the
GS segment base.  Since the GS segement is also used for percpu variables,
this forced the current layout.

GCC since version 8.1 supports a configurable location for the stack
protector value, which allows removal of the restriction on how the percpu
section is linked.  This allows the percpu section to be linked normally,
like other architectures.  In turn, this allows removal of code that was
needed to support the zero-based percpu section.

v5:
- Added two patches from Ard Biesheuvel to make stack protector work
  properly when compiling with clang.
- Raise minimum GCC version to 8.1 for x86.
- Drop objtool conversion code.

Ard Biesheuvel (2):
  x86/stackprotector: Work around strict Clang TLS symbol requirements
  x86/module: Deal with GOT based stack cookie load on Clang < 17

Brian Gerst (14):
  x86: Raise minimum GCC version to 8.1
  x86/stackprotector: Remove stack protector test scripts
  x86/boot: Disable stack protector for early boot code
  x86/pvh: Use fixed_percpu_data for early boot GSBASE
  x86/relocs: Handle R_X86_64_REX_GOTPCRELX relocations
  x86/stackprotector/64: Convert to normal percpu variable
  x86/percpu/64: Use relative percpu offsets
  x86/percpu/64: Remove fixed_percpu_data
  x86/boot/64: Remove inverse relocations
  x86/percpu/64: Remove INIT_PER_CPU macros
  percpu: Remove PER_CPU_FIRST_SECTION
  percpu: Remove PERCPU_VADDR()
  percpu: Remove __per_cpu_load
  kallsyms: Remove KALLSYMS_ABSOLUTE_PERCPU

 arch/x86/Kconfig                          |  11 +-
 arch/x86/Makefile                         |  19 +--
 arch/x86/boot/compressed/misc.c           |  14 +--
 arch/x86/entry/entry.S                    |  14 +++
 arch/x86/entry/entry_64.S                 |   2 +-
 arch/x86/include/asm/asm-prototypes.h     |   3 +
 arch/x86/include/asm/desc.h               |   1 -
 arch/x86/include/asm/elf.h                |   3 +-
 arch/x86/include/asm/percpu.h             |  22 ----
 arch/x86/include/asm/processor.h          |  28 +----
 arch/x86/include/asm/stackprotector.h     |  36 +-----
 arch/x86/kernel/Makefile                  |   2 +
 arch/x86/kernel/asm-offsets_64.c          |   6 -
 arch/x86/kernel/cpu/common.c              |  11 +-
 arch/x86/kernel/head64.c                  |   2 +-
 arch/x86/kernel/head_64.S                 |  20 ++-
 arch/x86/kernel/irq_64.c                  |   1 -
 arch/x86/kernel/module.c                  |  15 +++
 arch/x86/kernel/setup_percpu.c            |  12 +-
 arch/x86/kernel/vmlinux.lds.S             |  38 +-----
 arch/x86/platform/pvh/head.S              |  14 ++-
 arch/x86/tools/relocs.c                   | 147 ++--------------------
 arch/x86/xen/xen-head.S                   |  10 +-
 include/asm-generic/sections.h            |   2 +-
 include/asm-generic/vmlinux.lds.h         |  38 +-----
 include/linux/percpu-defs.h               |  12 --
 init/Kconfig                              |   5 -
 kernel/kallsyms.c                         |  12 +-
 mm/percpu.c                               |   4 +-
 scripts/gcc-x86_32-has-stack-protector.sh |   8 --
 scripts/gcc-x86_64-has-stack-protector.sh |   4 -
 scripts/kallsyms.c                        |  72 ++---------
 scripts/link-vmlinux.sh                   |   4 -
 scripts/min-tool-version.sh               |   2 +
 34 files changed, 122 insertions(+), 472 deletions(-)
 delete mode 100755 scripts/gcc-x86_32-has-stack-protector.sh
 delete mode 100755 scripts/gcc-x86_64-has-stack-protector.sh


base-commit: 4b9984799820b5b32b0ae1f3d8074886895a44e1
-- 
2.47.0


^ permalink raw reply	[flat|nested] 67+ messages in thread

* [PATCH v5 01/16] x86/stackprotector: Work around strict Clang TLS symbol requirements
  2024-11-05 15:57 [PATCH v5 00/16] x86-64: Stack protector and percpu improvements Brian Gerst
@ 2024-11-05 15:57 ` Brian Gerst
  2024-11-05 19:30   ` Nathan Chancellor
                     ` (3 more replies)
  2024-11-05 15:57 ` [PATCH v5 02/16] x86: Raise minimum GCC version to 8.1 Brian Gerst
                   ` (16 subsequent siblings)
  17 siblings, 4 replies; 67+ messages in thread
From: Brian Gerst @ 2024-11-05 15:57 UTC (permalink / raw)
  To: linux-kernel, x86
  Cc: Ingo Molnar, H . Peter Anvin, Thomas Gleixner, Borislav Petkov,
	Ard Biesheuvel, Uros Bizjak, stable, Fangrui Song,
	Nathan Chancellor, Andy Lutomirski, Brian Gerst

From: Ard Biesheuvel <ardb@kernel.org>

GCC and Clang both implement stack protector support based on Thread
Local Storage (TLS) variables, and this is used in the kernel to
implement per-task stack cookies, by copying a task's stack cookie into
a per-CPU variable every time it is scheduled in.

Both now also implement -mstack-protector-guard-symbol=, which permits
the TLS variable to be specified directly. This is useful because it
will allow us to move away from using a fixed offset of 40 bytes into
the per-CPU area on x86_64, which requires a lot of special handling in
the per-CPU code and the runtime relocation code.

However, while GCC is rather lax in its implementation of this command
line option, Clang actually requires that the provided symbol name
refers to a TLS variable (i.e., one declared with __thread), although it
also permits the variable to be undeclared entirely, in which case it
will use an implicit declaration of the right type.

The upshot of this is that Clang will emit the correct references to the
stack cookie variable in most cases, e.g.,

   10d:       64 a1 00 00 00 00       mov    %fs:0x0,%eax
                      10f: R_386_32   __stack_chk_guard

However, if a non-TLS definition of the symbol in question is visible in
the same compilation unit (which amounts to the whole of vmlinux if LTO
is enabled), it will drop the per-CPU prefix and emit a load from a
bogus address.

Work around this by using a symbol name that never occurs in C code, and
emit it as an alias in the linker script.

Fixes: 3fb0fdb3bbe7 ("x86/stackprotector/32: Make the canary into a regular percpu variable")
Cc: <stable@vger.kernel.org>
Cc: Fangrui Song <i@maskray.me>
Cc: Uros Bizjak <ubizjak@gmail.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Link: https://github.com/ClangBuiltLinux/linux/issues/1854
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Brian Gerst <brgerst@gmail.com>
---
 arch/x86/Makefile                     |  5 +++--
 arch/x86/entry/entry.S                | 16 ++++++++++++++++
 arch/x86/include/asm/asm-prototypes.h |  3 +++
 arch/x86/kernel/cpu/common.c          |  2 ++
 arch/x86/kernel/vmlinux.lds.S         |  3 +++
 5 files changed, 27 insertions(+), 2 deletions(-)

diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index cd75e78a06c1..5b773b34768d 100644
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -142,9 +142,10 @@ ifeq ($(CONFIG_X86_32),y)
 
     ifeq ($(CONFIG_STACKPROTECTOR),y)
         ifeq ($(CONFIG_SMP),y)
-			KBUILD_CFLAGS += -mstack-protector-guard-reg=fs -mstack-protector-guard-symbol=__stack_chk_guard
+            KBUILD_CFLAGS += -mstack-protector-guard-reg=fs \
+                             -mstack-protector-guard-symbol=__ref_stack_chk_guard
         else
-			KBUILD_CFLAGS += -mstack-protector-guard=global
+            KBUILD_CFLAGS += -mstack-protector-guard=global
         endif
     endif
 else
diff --git a/arch/x86/entry/entry.S b/arch/x86/entry/entry.S
index 324686bca368..b7ea3e8e9ecc 100644
--- a/arch/x86/entry/entry.S
+++ b/arch/x86/entry/entry.S
@@ -51,3 +51,19 @@ EXPORT_SYMBOL_GPL(mds_verw_sel);
 .popsection
 
 THUNK warn_thunk_thunk, __warn_thunk
+
+#ifndef CONFIG_X86_64
+/*
+ * Clang's implementation of TLS stack cookies requires the variable in
+ * question to be a TLS variable. If the variable happens to be defined as an
+ * ordinary variable with external linkage in the same compilation unit (which
+ * amounts to the whole of vmlinux with LTO enabled), Clang will drop the
+ * segment register prefix from the references, resulting in broken code. Work
+ * around this by avoiding the symbol used in -mstack-protector-guard-symbol=
+ * entirely in the C code, and use an alias emitted by the linker script
+ * instead.
+ */
+#ifdef CONFIG_STACKPROTECTOR
+EXPORT_SYMBOL(__ref_stack_chk_guard);
+#endif
+#endif
diff --git a/arch/x86/include/asm/asm-prototypes.h b/arch/x86/include/asm/asm-prototypes.h
index 25466c4d2134..3674006e3974 100644
--- a/arch/x86/include/asm/asm-prototypes.h
+++ b/arch/x86/include/asm/asm-prototypes.h
@@ -20,3 +20,6 @@
 extern void cmpxchg8b_emu(void);
 #endif
 
+#if defined(__GENKSYMS__) && defined(CONFIG_STACKPROTECTOR)
+extern unsigned long __ref_stack_chk_guard;
+#endif
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 8f41ab219cf1..9d42bd15e06c 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -2091,8 +2091,10 @@ void syscall_init(void)
 
 #ifdef CONFIG_STACKPROTECTOR
 DEFINE_PER_CPU(unsigned long, __stack_chk_guard);
+#ifndef CONFIG_SMP
 EXPORT_PER_CPU_SYMBOL(__stack_chk_guard);
 #endif
+#endif
 
 #endif	/* CONFIG_X86_64 */
 
diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index 410546bacc0f..d61c3584f3e6 100644
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -468,6 +468,9 @@ SECTIONS
 . = ASSERT((_end - LOAD_OFFSET <= KERNEL_IMAGE_SIZE),
 	   "kernel image bigger than KERNEL_IMAGE_SIZE");
 
+/* needed for Clang - see arch/x86/entry/entry.S */
+PROVIDE(__ref_stack_chk_guard = __stack_chk_guard);
+
 #ifdef CONFIG_X86_64
 /*
  * Per-cpu symbols which need to be offset from __per_cpu_load
-- 
2.47.0


^ permalink raw reply related	[flat|nested] 67+ messages in thread

* Re: [PATCH v5 01/16] x86/stackprotector: Work around strict Clang TLS symbol requirements
  2024-11-05 15:57 ` [PATCH v5 01/16] x86/stackprotector: Work around strict Clang TLS symbol requirements Brian Gerst
@ 2024-11-05 19:30   ` Nathan Chancellor
  2024-11-08 14:43   ` [tip: x86/urgent] " tip-bot2 for Ard Biesheuvel
                     ` (2 subsequent siblings)
  3 siblings, 0 replies; 67+ messages in thread
From: Nathan Chancellor @ 2024-11-05 19:30 UTC (permalink / raw)
  To: Brian Gerst
  Cc: linux-kernel, x86, Ingo Molnar, H . Peter Anvin, Thomas Gleixner,
	Borislav Petkov, Ard Biesheuvel, Uros Bizjak, stable,
	Fangrui Song, Andy Lutomirski

On Tue, Nov 05, 2024 at 10:57:46AM -0500, Brian Gerst wrote:
> From: Ard Biesheuvel <ardb@kernel.org>
> 
> GCC and Clang both implement stack protector support based on Thread
> Local Storage (TLS) variables, and this is used in the kernel to
> implement per-task stack cookies, by copying a task's stack cookie into
> a per-CPU variable every time it is scheduled in.
> 
> Both now also implement -mstack-protector-guard-symbol=, which permits
> the TLS variable to be specified directly. This is useful because it
> will allow us to move away from using a fixed offset of 40 bytes into
> the per-CPU area on x86_64, which requires a lot of special handling in
> the per-CPU code and the runtime relocation code.
> 
> However, while GCC is rather lax in its implementation of this command
> line option, Clang actually requires that the provided symbol name
> refers to a TLS variable (i.e., one declared with __thread), although it
> also permits the variable to be undeclared entirely, in which case it
> will use an implicit declaration of the right type.
> 
> The upshot of this is that Clang will emit the correct references to the
> stack cookie variable in most cases, e.g.,
> 
>    10d:       64 a1 00 00 00 00       mov    %fs:0x0,%eax
>                       10f: R_386_32   __stack_chk_guard
> 
> However, if a non-TLS definition of the symbol in question is visible in
> the same compilation unit (which amounts to the whole of vmlinux if LTO
> is enabled), it will drop the per-CPU prefix and emit a load from a
> bogus address.
> 
> Work around this by using a symbol name that never occurs in C code, and
> emit it as an alias in the linker script.
> 
> Fixes: 3fb0fdb3bbe7 ("x86/stackprotector/32: Make the canary into a regular percpu variable")
> Cc: <stable@vger.kernel.org>
> Cc: Fangrui Song <i@maskray.me>
> Cc: Uros Bizjak <ubizjak@gmail.com>
> Cc: Nathan Chancellor <nathan@kernel.org>
> Cc: Andy Lutomirski <luto@kernel.org>
> Link: https://github.com/ClangBuiltLinux/linux/issues/1854
> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
> Signed-off-by: Brian Gerst <brgerst@gmail.com>

From https://lore.kernel.org/20241016021045.GA1000009@thelio-3990X/:

Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>

> ---
>  arch/x86/Makefile                     |  5 +++--
>  arch/x86/entry/entry.S                | 16 ++++++++++++++++
>  arch/x86/include/asm/asm-prototypes.h |  3 +++
>  arch/x86/kernel/cpu/common.c          |  2 ++
>  arch/x86/kernel/vmlinux.lds.S         |  3 +++
>  5 files changed, 27 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/x86/Makefile b/arch/x86/Makefile
> index cd75e78a06c1..5b773b34768d 100644
> --- a/arch/x86/Makefile
> +++ b/arch/x86/Makefile
> @@ -142,9 +142,10 @@ ifeq ($(CONFIG_X86_32),y)
>  
>      ifeq ($(CONFIG_STACKPROTECTOR),y)
>          ifeq ($(CONFIG_SMP),y)
> -			KBUILD_CFLAGS += -mstack-protector-guard-reg=fs -mstack-protector-guard-symbol=__stack_chk_guard
> +            KBUILD_CFLAGS += -mstack-protector-guard-reg=fs \
> +                             -mstack-protector-guard-symbol=__ref_stack_chk_guard
>          else
> -			KBUILD_CFLAGS += -mstack-protector-guard=global
> +            KBUILD_CFLAGS += -mstack-protector-guard=global
>          endif
>      endif
>  else
> diff --git a/arch/x86/entry/entry.S b/arch/x86/entry/entry.S
> index 324686bca368..b7ea3e8e9ecc 100644
> --- a/arch/x86/entry/entry.S
> +++ b/arch/x86/entry/entry.S
> @@ -51,3 +51,19 @@ EXPORT_SYMBOL_GPL(mds_verw_sel);
>  .popsection
>  
>  THUNK warn_thunk_thunk, __warn_thunk
> +
> +#ifndef CONFIG_X86_64
> +/*
> + * Clang's implementation of TLS stack cookies requires the variable in
> + * question to be a TLS variable. If the variable happens to be defined as an
> + * ordinary variable with external linkage in the same compilation unit (which
> + * amounts to the whole of vmlinux with LTO enabled), Clang will drop the
> + * segment register prefix from the references, resulting in broken code. Work
> + * around this by avoiding the symbol used in -mstack-protector-guard-symbol=
> + * entirely in the C code, and use an alias emitted by the linker script
> + * instead.
> + */
> +#ifdef CONFIG_STACKPROTECTOR
> +EXPORT_SYMBOL(__ref_stack_chk_guard);
> +#endif
> +#endif
> diff --git a/arch/x86/include/asm/asm-prototypes.h b/arch/x86/include/asm/asm-prototypes.h
> index 25466c4d2134..3674006e3974 100644
> --- a/arch/x86/include/asm/asm-prototypes.h
> +++ b/arch/x86/include/asm/asm-prototypes.h
> @@ -20,3 +20,6 @@
>  extern void cmpxchg8b_emu(void);
>  #endif
>  
> +#if defined(__GENKSYMS__) && defined(CONFIG_STACKPROTECTOR)
> +extern unsigned long __ref_stack_chk_guard;
> +#endif
> diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
> index 8f41ab219cf1..9d42bd15e06c 100644
> --- a/arch/x86/kernel/cpu/common.c
> +++ b/arch/x86/kernel/cpu/common.c
> @@ -2091,8 +2091,10 @@ void syscall_init(void)
>  
>  #ifdef CONFIG_STACKPROTECTOR
>  DEFINE_PER_CPU(unsigned long, __stack_chk_guard);
> +#ifndef CONFIG_SMP
>  EXPORT_PER_CPU_SYMBOL(__stack_chk_guard);
>  #endif
> +#endif
>  
>  #endif	/* CONFIG_X86_64 */
>  
> diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
> index 410546bacc0f..d61c3584f3e6 100644
> --- a/arch/x86/kernel/vmlinux.lds.S
> +++ b/arch/x86/kernel/vmlinux.lds.S
> @@ -468,6 +468,9 @@ SECTIONS
>  . = ASSERT((_end - LOAD_OFFSET <= KERNEL_IMAGE_SIZE),
>  	   "kernel image bigger than KERNEL_IMAGE_SIZE");
>  
> +/* needed for Clang - see arch/x86/entry/entry.S */
> +PROVIDE(__ref_stack_chk_guard = __stack_chk_guard);
> +
>  #ifdef CONFIG_X86_64
>  /*
>   * Per-cpu symbols which need to be offset from __per_cpu_load
> -- 
> 2.47.0
> 

^ permalink raw reply	[flat|nested] 67+ messages in thread

* [tip: x86/urgent] x86/stackprotector: Work around strict Clang TLS symbol requirements
  2024-11-05 15:57 ` [PATCH v5 01/16] x86/stackprotector: Work around strict Clang TLS symbol requirements Brian Gerst
  2024-11-05 19:30   ` Nathan Chancellor
@ 2024-11-08 14:43   ` tip-bot2 for Ard Biesheuvel
  2024-12-06 11:51   ` [PATCH v5 01/16] " Oleg Nesterov
  2024-12-06 12:32   ` [PATCH] x86/stackprotector: fix build failure with CONFIG_STACKPROTECTOR=n Oleg Nesterov
  3 siblings, 0 replies; 67+ messages in thread
From: tip-bot2 for Ard Biesheuvel @ 2024-11-08 14:43 UTC (permalink / raw)
  To: linux-tip-commits
  Cc: Ard Biesheuvel, Brian Gerst, Borislav Petkov (AMD),
	Nathan Chancellor, stable, x86, linux-kernel

The following commit has been merged into the x86/urgent branch of tip:

Commit-ID:     577c134d311b9b94598d7a0c86be1f431f823003
Gitweb:        https://git.kernel.org/tip/577c134d311b9b94598d7a0c86be1f431f823003
Author:        Ard Biesheuvel <ardb@kernel.org>
AuthorDate:    Tue, 05 Nov 2024 10:57:46 -05:00
Committer:     Borislav Petkov (AMD) <bp@alien8.de>
CommitterDate: Fri, 08 Nov 2024 13:16:00 +01:00

x86/stackprotector: Work around strict Clang TLS symbol requirements

GCC and Clang both implement stack protector support based on Thread Local
Storage (TLS) variables, and this is used in the kernel to implement per-task
stack cookies, by copying a task's stack cookie into a per-CPU variable every
time it is scheduled in.

Both now also implement -mstack-protector-guard-symbol=, which permits the TLS
variable to be specified directly. This is useful because it will allow to
move away from using a fixed offset of 40 bytes into the per-CPU area on
x86_64, which requires a lot of special handling in the per-CPU code and the
runtime relocation code.

However, while GCC is rather lax in its implementation of this command line
option, Clang actually requires that the provided symbol name refers to a TLS
variable (i.e., one declared with __thread), although it also permits the
variable to be undeclared entirely, in which case it will use an implicit
declaration of the right type.

The upshot of this is that Clang will emit the correct references to the stack
cookie variable in most cases, e.g.,

  10d:       64 a1 00 00 00 00       mov    %fs:0x0,%eax
                     10f: R_386_32   __stack_chk_guard

However, if a non-TLS definition of the symbol in question is visible in the
same compilation unit (which amounts to the whole of vmlinux if LTO is
enabled), it will drop the per-CPU prefix and emit a load from a bogus
address.

Work around this by using a symbol name that never occurs in C code, and emit
it as an alias in the linker script.

Fixes: 3fb0fdb3bbe7 ("x86/stackprotector/32: Make the canary into a regular percpu variable")
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Cc: stable@vger.kernel.org
Link: https://github.com/ClangBuiltLinux/linux/issues/1854
Link: https://lore.kernel.org/r/20241105155801.1779119-2-brgerst@gmail.com
---
 arch/x86/Makefile                     |  5 +++--
 arch/x86/entry/entry.S                | 16 ++++++++++++++++
 arch/x86/include/asm/asm-prototypes.h |  3 +++
 arch/x86/kernel/cpu/common.c          |  2 ++
 arch/x86/kernel/vmlinux.lds.S         |  3 +++
 5 files changed, 27 insertions(+), 2 deletions(-)

diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index cd75e78..5b773b3 100644
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -142,9 +142,10 @@ ifeq ($(CONFIG_X86_32),y)
 
     ifeq ($(CONFIG_STACKPROTECTOR),y)
         ifeq ($(CONFIG_SMP),y)
-			KBUILD_CFLAGS += -mstack-protector-guard-reg=fs -mstack-protector-guard-symbol=__stack_chk_guard
+            KBUILD_CFLAGS += -mstack-protector-guard-reg=fs \
+                             -mstack-protector-guard-symbol=__ref_stack_chk_guard
         else
-			KBUILD_CFLAGS += -mstack-protector-guard=global
+            KBUILD_CFLAGS += -mstack-protector-guard=global
         endif
     endif
 else
diff --git a/arch/x86/entry/entry.S b/arch/x86/entry/entry.S
index 324686b..b7ea3e8 100644
--- a/arch/x86/entry/entry.S
+++ b/arch/x86/entry/entry.S
@@ -51,3 +51,19 @@ EXPORT_SYMBOL_GPL(mds_verw_sel);
 .popsection
 
 THUNK warn_thunk_thunk, __warn_thunk
+
+#ifndef CONFIG_X86_64
+/*
+ * Clang's implementation of TLS stack cookies requires the variable in
+ * question to be a TLS variable. If the variable happens to be defined as an
+ * ordinary variable with external linkage in the same compilation unit (which
+ * amounts to the whole of vmlinux with LTO enabled), Clang will drop the
+ * segment register prefix from the references, resulting in broken code. Work
+ * around this by avoiding the symbol used in -mstack-protector-guard-symbol=
+ * entirely in the C code, and use an alias emitted by the linker script
+ * instead.
+ */
+#ifdef CONFIG_STACKPROTECTOR
+EXPORT_SYMBOL(__ref_stack_chk_guard);
+#endif
+#endif
diff --git a/arch/x86/include/asm/asm-prototypes.h b/arch/x86/include/asm/asm-prototypes.h
index 25466c4..3674006 100644
--- a/arch/x86/include/asm/asm-prototypes.h
+++ b/arch/x86/include/asm/asm-prototypes.h
@@ -20,3 +20,6 @@
 extern void cmpxchg8b_emu(void);
 #endif
 
+#if defined(__GENKSYMS__) && defined(CONFIG_STACKPROTECTOR)
+extern unsigned long __ref_stack_chk_guard;
+#endif
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index a5f221e..f43bb97 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -2089,8 +2089,10 @@ void syscall_init(void)
 
 #ifdef CONFIG_STACKPROTECTOR
 DEFINE_PER_CPU(unsigned long, __stack_chk_guard);
+#ifndef CONFIG_SMP
 EXPORT_PER_CPU_SYMBOL(__stack_chk_guard);
 #endif
+#endif
 
 #endif	/* CONFIG_X86_64 */
 
diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index b8c5741..feb8102 100644
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -491,6 +491,9 @@ SECTIONS
 . = ASSERT((_end - LOAD_OFFSET <= KERNEL_IMAGE_SIZE),
 	   "kernel image bigger than KERNEL_IMAGE_SIZE");
 
+/* needed for Clang - see arch/x86/entry/entry.S */
+PROVIDE(__ref_stack_chk_guard = __stack_chk_guard);
+
 #ifdef CONFIG_X86_64
 /*
  * Per-cpu symbols which need to be offset from __per_cpu_load

^ permalink raw reply related	[flat|nested] 67+ messages in thread

* Re: [PATCH v5 01/16] x86/stackprotector: Work around strict Clang TLS symbol requirements
  2024-11-05 15:57 ` [PATCH v5 01/16] x86/stackprotector: Work around strict Clang TLS symbol requirements Brian Gerst
  2024-11-05 19:30   ` Nathan Chancellor
  2024-11-08 14:43   ` [tip: x86/urgent] " tip-bot2 for Ard Biesheuvel
@ 2024-12-06 11:51   ` Oleg Nesterov
  2024-12-06 14:09     ` Brian Gerst
  2024-12-06 12:32   ` [PATCH] x86/stackprotector: fix build failure with CONFIG_STACKPROTECTOR=n Oleg Nesterov
  3 siblings, 1 reply; 67+ messages in thread
From: Oleg Nesterov @ 2024-12-06 11:51 UTC (permalink / raw)
  To: Brian Gerst
  Cc: linux-kernel, x86, Ingo Molnar, H . Peter Anvin, Thomas Gleixner,
	Borislav Petkov, Ard Biesheuvel, Uros Bizjak, stable,
	Fangrui Song, Nathan Chancellor, Andy Lutomirski

On 11/05, Brian Gerst wrote:
>
> --- a/arch/x86/kernel/vmlinux.lds.S
> +++ b/arch/x86/kernel/vmlinux.lds.S
> @@ -468,6 +468,9 @@ SECTIONS
>  . = ASSERT((_end - LOAD_OFFSET <= KERNEL_IMAGE_SIZE),
>  	   "kernel image bigger than KERNEL_IMAGE_SIZE");
>
> +/* needed for Clang - see arch/x86/entry/entry.S */
> +PROVIDE(__ref_stack_chk_guard = __stack_chk_guard);

Don't we need the simple fix below?

without this patch I can't build the kernel with CONFIG_STACKPROTECTOR=n.

Oleg.

diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index fab3ac9a4574..2ff48645bab9 100644
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -472,8 +472,10 @@ SECTIONS
 . = ASSERT((_end - LOAD_OFFSET <= KERNEL_IMAGE_SIZE),
 	   "kernel image bigger than KERNEL_IMAGE_SIZE");
 
+#ifdef CONFIG_STACKPROTECTOR
 /* needed for Clang - see arch/x86/entry/entry.S */
 PROVIDE(__ref_stack_chk_guard = __stack_chk_guard);
+#endif
 
 #ifdef CONFIG_X86_64
 /*


^ permalink raw reply related	[flat|nested] 67+ messages in thread

* Re: [PATCH v5 01/16] x86/stackprotector: Work around strict Clang TLS symbol requirements
  2024-12-06 11:51   ` [PATCH v5 01/16] " Oleg Nesterov
@ 2024-12-06 14:09     ` Brian Gerst
  2024-12-06 14:28       ` Oleg Nesterov
  0 siblings, 1 reply; 67+ messages in thread
From: Brian Gerst @ 2024-12-06 14:09 UTC (permalink / raw)
  To: Oleg Nesterov
  Cc: linux-kernel, x86, Ingo Molnar, H . Peter Anvin, Thomas Gleixner,
	Borislav Petkov, Ard Biesheuvel, Uros Bizjak, stable,
	Fangrui Song, Nathan Chancellor, Andy Lutomirski

On Fri, Dec 6, 2024 at 6:52 AM Oleg Nesterov <oleg@redhat.com> wrote:
>
> On 11/05, Brian Gerst wrote:
> >
> > --- a/arch/x86/kernel/vmlinux.lds.S
> > +++ b/arch/x86/kernel/vmlinux.lds.S
> > @@ -468,6 +468,9 @@ SECTIONS
> >  . = ASSERT((_end - LOAD_OFFSET <= KERNEL_IMAGE_SIZE),
> >          "kernel image bigger than KERNEL_IMAGE_SIZE");
> >
> > +/* needed for Clang - see arch/x86/entry/entry.S */
> > +PROVIDE(__ref_stack_chk_guard = __stack_chk_guard);
>
> Don't we need the simple fix below?
>
> without this patch I can't build the kernel with CONFIG_STACKPROTECTOR=n.
>
> Oleg.
>
> diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
> index fab3ac9a4574..2ff48645bab9 100644
> --- a/arch/x86/kernel/vmlinux.lds.S
> +++ b/arch/x86/kernel/vmlinux.lds.S
> @@ -472,8 +472,10 @@ SECTIONS
>  . = ASSERT((_end - LOAD_OFFSET <= KERNEL_IMAGE_SIZE),
>            "kernel image bigger than KERNEL_IMAGE_SIZE");
>
> +#ifdef CONFIG_STACKPROTECTOR
>  /* needed for Clang - see arch/x86/entry/entry.S */
>  PROVIDE(__ref_stack_chk_guard = __stack_chk_guard);
> +#endif
>
>  #ifdef CONFIG_X86_64
>  /*

Which compiler are you using?  It builds fine with GCC 14 and clang 18.


Brian Gerst

^ permalink raw reply	[flat|nested] 67+ messages in thread

* Re: [PATCH v5 01/16] x86/stackprotector: Work around strict Clang TLS symbol requirements
  2024-12-06 14:09     ` Brian Gerst
@ 2024-12-06 14:28       ` Oleg Nesterov
  0 siblings, 0 replies; 67+ messages in thread
From: Oleg Nesterov @ 2024-12-06 14:28 UTC (permalink / raw)
  To: Brian Gerst
  Cc: linux-kernel, x86, Ingo Molnar, H . Peter Anvin, Thomas Gleixner,
	Borislav Petkov, Ard Biesheuvel, Uros Bizjak, stable,
	Fangrui Song, Nathan Chancellor, Andy Lutomirski

On 12/06, Brian Gerst wrote:
>
> On Fri, Dec 6, 2024 at 6:52 AM Oleg Nesterov <oleg@redhat.com> wrote:
> >
> > On 11/05, Brian Gerst wrote:
> > >
> > > --- a/arch/x86/kernel/vmlinux.lds.S
> > > +++ b/arch/x86/kernel/vmlinux.lds.S
> > > @@ -468,6 +468,9 @@ SECTIONS
> > >  . = ASSERT((_end - LOAD_OFFSET <= KERNEL_IMAGE_SIZE),
> > >          "kernel image bigger than KERNEL_IMAGE_SIZE");
> > >
> > > +/* needed for Clang - see arch/x86/entry/entry.S */
> > > +PROVIDE(__ref_stack_chk_guard = __stack_chk_guard);
> >
> > Don't we need the simple fix below?
> >
> > without this patch I can't build the kernel with CONFIG_STACKPROTECTOR=n.
...

> Which compiler are you using?  It builds fine with GCC 14 and clang 18.

gcc version 5.3.1 20160406 (Red Hat 5.3.1-6) (GCC)
GNU ld version 2.25-17.fc23

See also my reply to Ard

Oleg.


^ permalink raw reply	[flat|nested] 67+ messages in thread

* [PATCH] x86/stackprotector: fix build failure with CONFIG_STACKPROTECTOR=n
  2024-11-05 15:57 ` [PATCH v5 01/16] x86/stackprotector: Work around strict Clang TLS symbol requirements Brian Gerst
                     ` (2 preceding siblings ...)
  2024-12-06 11:51   ` [PATCH v5 01/16] " Oleg Nesterov
@ 2024-12-06 12:32   ` Oleg Nesterov
  2024-12-06 13:17     ` Ard Biesheuvel
  3 siblings, 1 reply; 67+ messages in thread
From: Oleg Nesterov @ 2024-12-06 12:32 UTC (permalink / raw)
  To: Brian Gerst
  Cc: linux-kernel, x86, Ingo Molnar, H . Peter Anvin, Thomas Gleixner,
	Borislav Petkov, Ard Biesheuvel, Uros Bizjak, stable,
	Fangrui Song, Nathan Chancellor, Andy Lutomirski

Add the necessary '#ifdef CONFIG_STACKPROTECTOR' into
arch/x86/kernel/vmlinux.lds.S

Fixes: 577c134d311b ("x86/stackprotector: Work around strict Clang TLS symbol requirements")
Cc: stable@vger.kernel.org
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
---
 arch/x86/kernel/vmlinux.lds.S | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index fab3ac9a4574..2ff48645bab9 100644
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -472,8 +472,10 @@ SECTIONS
 . = ASSERT((_end - LOAD_OFFSET <= KERNEL_IMAGE_SIZE),
 	   "kernel image bigger than KERNEL_IMAGE_SIZE");
 
+#ifdef CONFIG_STACKPROTECTOR
 /* needed for Clang - see arch/x86/entry/entry.S */
 PROVIDE(__ref_stack_chk_guard = __stack_chk_guard);
+#endif
 
 #ifdef CONFIG_X86_64
 /*
-- 
2.25.1.362.g51ebf55



^ permalink raw reply related	[flat|nested] 67+ messages in thread

* Re: [PATCH] x86/stackprotector: fix build failure with CONFIG_STACKPROTECTOR=n
  2024-12-06 12:32   ` [PATCH] x86/stackprotector: fix build failure with CONFIG_STACKPROTECTOR=n Oleg Nesterov
@ 2024-12-06 13:17     ` Ard Biesheuvel
  2024-12-06 14:21       ` Oleg Nesterov
  0 siblings, 1 reply; 67+ messages in thread
From: Ard Biesheuvel @ 2024-12-06 13:17 UTC (permalink / raw)
  To: Oleg Nesterov
  Cc: Brian Gerst, linux-kernel, x86, Ingo Molnar, H . Peter Anvin,
	Thomas Gleixner, Borislav Petkov, Uros Bizjak, stable,
	Fangrui Song, Nathan Chancellor, Andy Lutomirski

On Fri, 6 Dec 2024 at 13:32, Oleg Nesterov <oleg@redhat.com> wrote:
>
> Add the necessary '#ifdef CONFIG_STACKPROTECTOR' into
> arch/x86/kernel/vmlinux.lds.S
>
> Fixes: 577c134d311b ("x86/stackprotector: Work around strict Clang TLS symbol requirements")
> Cc: stable@vger.kernel.org
> Signed-off-by: Oleg Nesterov <oleg@redhat.com>
> ---
>  arch/x86/kernel/vmlinux.lds.S | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
> index fab3ac9a4574..2ff48645bab9 100644
> --- a/arch/x86/kernel/vmlinux.lds.S
> +++ b/arch/x86/kernel/vmlinux.lds.S
> @@ -472,8 +472,10 @@ SECTIONS
>  . = ASSERT((_end - LOAD_OFFSET <= KERNEL_IMAGE_SIZE),
>            "kernel image bigger than KERNEL_IMAGE_SIZE");
>
> +#ifdef CONFIG_STACKPROTECTOR
>  /* needed for Clang - see arch/x86/entry/entry.S */
>  PROVIDE(__ref_stack_chk_guard = __stack_chk_guard);
> +#endif
>
>  #ifdef CONFIG_X86_64
>  /*

This shouldn't be necessary - PROVIDE() is only evaluated if a
reference exists to the symbol it defines.

Also, I'm failing to reproduce this. Could you share your .config,
please, and the error that you get during the build?

^ permalink raw reply	[flat|nested] 67+ messages in thread

* Re: [PATCH] x86/stackprotector: fix build failure with CONFIG_STACKPROTECTOR=n
  2024-12-06 13:17     ` Ard Biesheuvel
@ 2024-12-06 14:21       ` Oleg Nesterov
  2024-12-06 14:37         ` Ard Biesheuvel
  0 siblings, 1 reply; 67+ messages in thread
From: Oleg Nesterov @ 2024-12-06 14:21 UTC (permalink / raw)
  To: Ard Biesheuvel
  Cc: Brian Gerst, linux-kernel, x86, Ingo Molnar, H . Peter Anvin,
	Thomas Gleixner, Borislav Petkov, Uros Bizjak, stable,
	Fangrui Song, Nathan Chancellor, Andy Lutomirski

[-- Attachment #1: Type: text/plain, Size: 1486 bytes --]

On 12/06, Ard Biesheuvel wrote:
>
> On Fri, 6 Dec 2024 at 13:32, Oleg Nesterov <oleg@redhat.com> wrote:
> >
> > +#ifdef CONFIG_STACKPROTECTOR
> >  /* needed for Clang - see arch/x86/entry/entry.S */
> >  PROVIDE(__ref_stack_chk_guard = __stack_chk_guard);
> > +#endif
> >
> >  #ifdef CONFIG_X86_64
> >  /*
>
> This shouldn't be necessary - PROVIDE() is only evaluated if a
> reference exists to the symbol it defines.
>
> Also, I'm failing to reproduce this. Could you share your .config,
> please, and the error that you get during the build?

Please see the attached .config

without the change above:

	$ make bzImage
	  CALL    scripts/checksyscalls.sh
	  DESCEND objtool
	  INSTALL libsubcmd_headers
	  UPD     include/generated/utsversion.h
	  CC      init/version-timestamp.o
	  KSYMS   .tmp_vmlinux0.kallsyms.S
	  AS      .tmp_vmlinux0.kallsyms.o
	  LD      .tmp_vmlinux1
	./arch/x86/kernel/vmlinux.lds:154: undefined symbol `__stack_chk_guard' referenced in expression
	scripts/Makefile.vmlinux:77: recipe for target 'vmlinux' failed
	make[2]: *** [vmlinux] Error 1
	/home/oleg/tmp/LINUX/Makefile:1225: recipe for target 'vmlinux' failed
	make[1]: *** [vmlinux] Error 2
	Makefile:251: recipe for target '__sub-make' failed
	make: *** [__sub-make] Error 2

perhaps this is because my toolchain is quite old,

	$ ld -v
	GNU ld version 2.25-17.fc23

but according to Documentation/process/changes.rst

	binutils               2.25             ld -v

it is still supported.

Oleg.

[-- Attachment #2: .config --]
[-- Type: text/plain, Size: 66066 bytes --]

#
# Automatically generated file; DO NOT EDIT.
# Linux/x86 6.13.0-rc1 Kernel Configuration
#
CONFIG_CC_VERSION_TEXT="gcc (GCC) 5.3.1 20160406 (Red Hat 5.3.1-6)"
CONFIG_CC_IS_GCC=y
CONFIG_GCC_VERSION=50301
CONFIG_CLANG_VERSION=0
CONFIG_AS_IS_GNU=y
CONFIG_AS_VERSION=22500
CONFIG_LD_IS_BFD=y
CONFIG_LD_VERSION=22500
CONFIG_LLD_VERSION=0
CONFIG_RUSTC_VERSION=0
CONFIG_RUSTC_LLVM_VERSION=0
CONFIG_CC_CAN_LINK=y
CONFIG_CC_CAN_LINK_STATIC=y
CONFIG_GCC_ASM_GOTO_OUTPUT_BROKEN=y
CONFIG_PAHOLE_VERSION=0
CONFIG_IRQ_WORK=y
CONFIG_BUILDTIME_TABLE_SORT=y
CONFIG_THREAD_INFO_IN_TASK=y

#
# General setup
#
CONFIG_INIT_ENV_ARG_LIMIT=32
# CONFIG_COMPILE_TEST is not set
# CONFIG_WERROR is not set
CONFIG_LOCALVERSION=""
CONFIG_LOCALVERSION_AUTO=y
CONFIG_BUILD_SALT="n"
CONFIG_HAVE_KERNEL_GZIP=y
CONFIG_HAVE_KERNEL_BZIP2=y
CONFIG_HAVE_KERNEL_LZMA=y
CONFIG_HAVE_KERNEL_XZ=y
CONFIG_HAVE_KERNEL_LZO=y
CONFIG_HAVE_KERNEL_LZ4=y
CONFIG_HAVE_KERNEL_ZSTD=y
CONFIG_KERNEL_GZIP=y
# CONFIG_KERNEL_BZIP2 is not set
# CONFIG_KERNEL_LZMA is not set
# CONFIG_KERNEL_XZ is not set
# CONFIG_KERNEL_LZO is not set
# CONFIG_KERNEL_LZ4 is not set
# CONFIG_KERNEL_ZSTD is not set
CONFIG_DEFAULT_INIT="1"
CONFIG_DEFAULT_HOSTNAME="(none)"
CONFIG_SYSVIPC=y
CONFIG_SYSVIPC_SYSCTL=y
CONFIG_SYSVIPC_COMPAT=y
CONFIG_POSIX_MQUEUE=y
CONFIG_POSIX_MQUEUE_SYSCTL=y
# CONFIG_WATCH_QUEUE is not set
# CONFIG_CROSS_MEMORY_ATTACH is not set
# CONFIG_USELIB is not set
# CONFIG_AUDIT is not set
CONFIG_HAVE_ARCH_AUDITSYSCALL=y

#
# IRQ subsystem
#
CONFIG_GENERIC_IRQ_PROBE=y
CONFIG_GENERIC_IRQ_SHOW=y
CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK=y
CONFIG_GENERIC_PENDING_IRQ=y
CONFIG_GENERIC_IRQ_MIGRATION=y
CONFIG_HARDIRQS_SW_RESEND=y
CONFIG_IRQ_DOMAIN=y
CONFIG_IRQ_DOMAIN_HIERARCHY=y
CONFIG_GENERIC_MSI_IRQ=y
CONFIG_GENERIC_IRQ_MATRIX_ALLOCATOR=y
CONFIG_GENERIC_IRQ_RESERVATION_MODE=y
CONFIG_IRQ_FORCED_THREADING=y
CONFIG_SPARSE_IRQ=y
# CONFIG_GENERIC_IRQ_DEBUGFS is not set
# end of IRQ subsystem

CONFIG_CLOCKSOURCE_WATCHDOG=y
CONFIG_ARCH_CLOCKSOURCE_INIT=y
CONFIG_GENERIC_TIME_VSYSCALL=y
CONFIG_GENERIC_CLOCKEVENTS=y
CONFIG_GENERIC_CLOCKEVENTS_BROADCAST=y
CONFIG_GENERIC_CLOCKEVENTS_BROADCAST_IDLE=y
CONFIG_GENERIC_CLOCKEVENTS_MIN_ADJUST=y
CONFIG_GENERIC_CMOS_UPDATE=y
CONFIG_HAVE_POSIX_CPU_TIMERS_TASK_WORK=y
CONFIG_POSIX_CPU_TIMERS_TASK_WORK=y
CONFIG_CONTEXT_TRACKING=y
CONFIG_CONTEXT_TRACKING_IDLE=y

#
# Timers subsystem
#
CONFIG_TICK_ONESHOT=y
CONFIG_NO_HZ_COMMON=y
# CONFIG_HZ_PERIODIC is not set
CONFIG_NO_HZ_IDLE=y
# CONFIG_NO_HZ_FULL is not set
CONFIG_NO_HZ=y
CONFIG_HIGH_RES_TIMERS=y
CONFIG_CLOCKSOURCE_WATCHDOG_MAX_SKEW_US=100
# end of Timers subsystem

CONFIG_BPF=y
CONFIG_HAVE_EBPF_JIT=y
CONFIG_ARCH_WANT_DEFAULT_BPF_JIT=y

#
# BPF subsystem
#
CONFIG_BPF_SYSCALL=y
# CONFIG_BPF_JIT is not set
# CONFIG_BPF_UNPRIV_DEFAULT_OFF is not set
# CONFIG_BPF_PRELOAD is not set
# end of BPF subsystem

CONFIG_PREEMPT_BUILD=y
CONFIG_ARCH_HAS_PREEMPT_LAZY=y
# CONFIG_PREEMPT_NONE is not set
# CONFIG_PREEMPT_VOLUNTARY is not set
CONFIG_PREEMPT=y
# CONFIG_PREEMPT_LAZY is not set
# CONFIG_PREEMPT_RT is not set
CONFIG_PREEMPT_COUNT=y
CONFIG_PREEMPTION=y
CONFIG_PREEMPT_DYNAMIC=y
CONFIG_SCHED_CORE=y

#
# CPU/Task time and stats accounting
#
CONFIG_TICK_CPU_ACCOUNTING=y
# CONFIG_VIRT_CPU_ACCOUNTING_GEN is not set
# CONFIG_IRQ_TIME_ACCOUNTING is not set
# CONFIG_BSD_PROCESS_ACCT is not set
# CONFIG_TASKSTATS is not set
# CONFIG_PSI is not set
# end of CPU/Task time and stats accounting

# CONFIG_CPU_ISOLATION is not set

#
# RCU Subsystem
#
CONFIG_TREE_RCU=y
CONFIG_PREEMPT_RCU=y
# CONFIG_RCU_EXPERT is not set
CONFIG_TREE_SRCU=y
CONFIG_TASKS_RCU_GENERIC=y
CONFIG_NEED_TASKS_RCU=y
CONFIG_TASKS_RCU=y
CONFIG_TASKS_RUDE_RCU=y
CONFIG_TASKS_TRACE_RCU=y
CONFIG_RCU_STALL_COMMON=y
CONFIG_RCU_NEED_SEGCBLIST=y
# end of RCU Subsystem

CONFIG_IKCONFIG=y
CONFIG_IKCONFIG_PROC=y
# CONFIG_IKHEADERS is not set
CONFIG_LOG_BUF_SHIFT=19
CONFIG_LOG_CPU_MAX_BUF_SHIFT=12
# CONFIG_PRINTK_INDEX is not set
CONFIG_HAVE_UNSTABLE_SCHED_CLOCK=y

#
# Scheduler features
#
# end of Scheduler features

CONFIG_ARCH_SUPPORTS_NUMA_BALANCING=y
CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH=y
CONFIG_CC_HAS_INT128=y
CONFIG_GCC10_NO_ARRAY_BOUNDS=y
CONFIG_GCC_NO_STRINGOP_OVERFLOW=y
CONFIG_CC_NO_STRINGOP_OVERFLOW=y
CONFIG_ARCH_SUPPORTS_INT128=y
CONFIG_SLAB_OBJ_EXT=y
CONFIG_CGROUPS=y
CONFIG_PAGE_COUNTER=y
CONFIG_CGROUP_FAVOR_DYNMODS=y
CONFIG_MEMCG=y
# CONFIG_MEMCG_V1 is not set
# CONFIG_BLK_CGROUP is not set
CONFIG_CGROUP_SCHED=y
CONFIG_GROUP_SCHED_WEIGHT=y
CONFIG_FAIR_GROUP_SCHED=y
# CONFIG_CFS_BANDWIDTH is not set
CONFIG_RT_GROUP_SCHED=y
CONFIG_CGROUP_PIDS=y
# CONFIG_CGROUP_RDMA is not set
# CONFIG_CGROUP_FREEZER is not set
# CONFIG_CGROUP_HUGETLB is not set
# CONFIG_CPUSETS is not set
# CONFIG_CGROUP_DEVICE is not set
# CONFIG_CGROUP_CPUACCT is not set
CONFIG_CGROUP_PERF=y
# CONFIG_CGROUP_BPF is not set
# CONFIG_CGROUP_MISC is not set
# CONFIG_CGROUP_DEBUG is not set
CONFIG_NAMESPACES=y
CONFIG_UTS_NS=y
CONFIG_TIME_NS=y
CONFIG_IPC_NS=y
CONFIG_USER_NS=y
CONFIG_PID_NS=y
CONFIG_NET_NS=y
CONFIG_CHECKPOINT_RESTORE=y
CONFIG_SCHED_AUTOGROUP=y
# CONFIG_RELAY is not set
CONFIG_BLK_DEV_INITRD=y
CONFIG_INITRAMFS_SOURCE=""
CONFIG_RD_GZIP=y
# CONFIG_RD_BZIP2 is not set
# CONFIG_RD_LZMA is not set
# CONFIG_RD_XZ is not set
# CONFIG_RD_LZO is not set
# CONFIG_RD_LZ4 is not set
# CONFIG_RD_ZSTD is not set
CONFIG_BOOT_CONFIG=y
# CONFIG_BOOT_CONFIG_FORCE is not set
# CONFIG_BOOT_CONFIG_EMBED is not set
# CONFIG_INITRAMFS_PRESERVE_MTIME is not set
# CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE is not set
CONFIG_CC_OPTIMIZE_FOR_SIZE=y
CONFIG_SYSCTL=y
CONFIG_HAVE_UID16=y
CONFIG_SYSCTL_EXCEPTION_TRACE=y
CONFIG_HAVE_PCSPKR_PLATFORM=y
CONFIG_EXPERT=y
CONFIG_UID16=y
CONFIG_MULTIUSER=y
# CONFIG_SGETMASK_SYSCALL is not set
# CONFIG_SYSFS_SYSCALL is not set
# CONFIG_FHANDLE is not set
CONFIG_POSIX_TIMERS=y
CONFIG_PRINTK=y
CONFIG_BUG=y
CONFIG_ELF_CORE=y
# CONFIG_PCSPKR_PLATFORM is not set
# CONFIG_BASE_SMALL is not set
CONFIG_FUTEX=y
CONFIG_FUTEX_PI=y
CONFIG_EPOLL=y
CONFIG_SIGNALFD=y
CONFIG_TIMERFD=y
CONFIG_EVENTFD=y
CONFIG_SHMEM=y
CONFIG_AIO=y
CONFIG_IO_URING=y
CONFIG_ADVISE_SYSCALLS=y
CONFIG_MEMBARRIER=y
CONFIG_KCMP=y
# CONFIG_RSEQ is not set
CONFIG_CACHESTAT_SYSCALL=y
# CONFIG_PC104 is not set
CONFIG_KALLSYMS=y
# CONFIG_KALLSYMS_SELFTEST is not set
CONFIG_KALLSYMS_ALL=y
CONFIG_KALLSYMS_ABSOLUTE_PERCPU=y
CONFIG_ARCH_HAS_MEMBARRIER_SYNC_CORE=y
CONFIG_HAVE_PERF_EVENTS=y

#
# Kernel Performance Events And Counters
#
CONFIG_PERF_EVENTS=y
# CONFIG_DEBUG_PERF_USE_VMALLOC is not set
# end of Kernel Performance Events And Counters

# CONFIG_PROFILING is not set
CONFIG_TRACEPOINTS=y

#
# Kexec and crash features
#
CONFIG_VMCORE_INFO=y
# CONFIG_KEXEC is not set
# CONFIG_KEXEC_FILE is not set
# end of Kexec and crash features
# end of General setup

CONFIG_64BIT=y
CONFIG_X86_64=y
CONFIG_X86=y
CONFIG_INSTRUCTION_DECODER=y
CONFIG_OUTPUT_FORMAT="elf64-x86-64"
CONFIG_LOCKDEP_SUPPORT=y
CONFIG_STACKTRACE_SUPPORT=y
CONFIG_MMU=y
CONFIG_ARCH_MMAP_RND_BITS_MIN=28
CONFIG_ARCH_MMAP_RND_BITS_MAX=32
CONFIG_ARCH_MMAP_RND_COMPAT_BITS_MIN=8
CONFIG_ARCH_MMAP_RND_COMPAT_BITS_MAX=16
CONFIG_GENERIC_BUG=y
CONFIG_GENERIC_BUG_RELATIVE_POINTERS=y
CONFIG_GENERIC_CALIBRATE_DELAY=y
CONFIG_ARCH_HAS_CPU_RELAX=y
CONFIG_ARCH_HIBERNATION_POSSIBLE=y
CONFIG_ARCH_SUSPEND_POSSIBLE=y
CONFIG_AUDIT_ARCH=y
CONFIG_X86_64_SMP=y
CONFIG_ARCH_SUPPORTS_UPROBES=y
CONFIG_FIX_EARLYCON_MEM=y
CONFIG_PGTABLE_LEVELS=4
CONFIG_CC_HAS_SANE_STACKPROTECTOR=y

#
# Processor type and features
#
CONFIG_SMP=y
# CONFIG_X86_MPPARSE is not set
# CONFIG_X86_CPU_RESCTRL is not set
# CONFIG_X86_FRED is not set
# CONFIG_X86_EXTENDED_PLATFORM is not set
# CONFIG_X86_INTEL_LPSS is not set
# CONFIG_X86_AMD_PLATFORM_DEVICE is not set
# CONFIG_IOSF_MBI is not set
# CONFIG_SCHED_OMIT_FRAME_POINTER is not set
# CONFIG_HYPERVISOR_GUEST is not set
# CONFIG_MK8 is not set
# CONFIG_MPSC is not set
# CONFIG_MCORE2 is not set
# CONFIG_MATOM is not set
CONFIG_GENERIC_CPU=y
CONFIG_X86_INTERNODE_CACHE_SHIFT=6
CONFIG_X86_L1_CACHE_SHIFT=6
CONFIG_X86_TSC=y
CONFIG_X86_HAVE_PAE=y
CONFIG_X86_CMPXCHG64=y
CONFIG_X86_CMOV=y
CONFIG_X86_MINIMUM_CPU_FAMILY=64
CONFIG_X86_DEBUGCTLMSR=y
CONFIG_IA32_FEAT_CTL=y
CONFIG_X86_VMX_FEATURE_NAMES=y
# CONFIG_PROCESSOR_SELECT is not set
CONFIG_CPU_SUP_INTEL=y
CONFIG_CPU_SUP_AMD=y
CONFIG_CPU_SUP_HYGON=y
CONFIG_CPU_SUP_CENTAUR=y
CONFIG_CPU_SUP_ZHAOXIN=y
CONFIG_HPET_TIMER=y
# CONFIG_DMI is not set
# CONFIG_GART_IOMMU is not set
# CONFIG_MAXSMP is not set
CONFIG_NR_CPUS_RANGE_BEGIN=2
CONFIG_NR_CPUS_RANGE_END=512
CONFIG_NR_CPUS_DEFAULT=64
CONFIG_NR_CPUS=16
# CONFIG_SCHED_CLUSTER is not set
CONFIG_SCHED_SMT=y
CONFIG_SCHED_MC=y
# CONFIG_SCHED_MC_PRIO is not set
CONFIG_X86_LOCAL_APIC=y
CONFIG_ACPI_MADT_WAKEUP=y
CONFIG_X86_IO_APIC=y
# CONFIG_X86_REROUTE_FOR_BROKEN_BOOT_IRQS is not set
# CONFIG_X86_MCE is not set

#
# Performance monitoring
#
CONFIG_PERF_EVENTS_INTEL_UNCORE=y
CONFIG_PERF_EVENTS_INTEL_RAPL=y
CONFIG_PERF_EVENTS_INTEL_CSTATE=y
# CONFIG_PERF_EVENTS_AMD_POWER is not set
# CONFIG_PERF_EVENTS_AMD_UNCORE is not set
# CONFIG_PERF_EVENTS_AMD_BRS is not set
# end of Performance monitoring

CONFIG_X86_VSYSCALL_EMULATION=y
# CONFIG_X86_IOPL_IOPERM is not set
CONFIG_MICROCODE=y
# CONFIG_MICROCODE_LATE_LOADING is not set
# CONFIG_X86_MSR is not set
# CONFIG_X86_CPUID is not set
# CONFIG_X86_5LEVEL is not set
CONFIG_X86_DIRECT_GBPAGES=y
# CONFIG_X86_CPA_STATISTICS is not set
# CONFIG_NUMA is not set
CONFIG_ARCH_SPARSEMEM_ENABLE=y
CONFIG_ARCH_SPARSEMEM_DEFAULT=y
CONFIG_ARCH_PROC_KCORE_TEXT=y
CONFIG_ILLEGAL_POINTER_VALUE=0xdead000000000000
# CONFIG_X86_PMEM_LEGACY is not set
# CONFIG_X86_CHECK_BIOS_CORRUPTION is not set
CONFIG_MTRR=y
# CONFIG_MTRR_SANITIZER is not set
CONFIG_X86_PAT=y
# CONFIG_X86_UMIP is not set
# CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS is not set
CONFIG_ARCH_PKEY_BITS=4
CONFIG_X86_INTEL_TSX_MODE_OFF=y
# CONFIG_X86_INTEL_TSX_MODE_ON is not set
# CONFIG_X86_INTEL_TSX_MODE_AUTO is not set
# CONFIG_EFI is not set
# CONFIG_HZ_100 is not set
# CONFIG_HZ_250 is not set
CONFIG_HZ_300=y
# CONFIG_HZ_1000 is not set
CONFIG_HZ=300
CONFIG_SCHED_HRTICK=y
CONFIG_ARCH_SUPPORTS_KEXEC=y
CONFIG_ARCH_SUPPORTS_KEXEC_FILE=y
CONFIG_ARCH_SUPPORTS_KEXEC_PURGATORY=y
CONFIG_ARCH_SUPPORTS_KEXEC_SIG=y
CONFIG_ARCH_SUPPORTS_KEXEC_SIG_FORCE=y
CONFIG_ARCH_SUPPORTS_KEXEC_BZIMAGE_VERIFY_SIG=y
CONFIG_ARCH_SUPPORTS_KEXEC_JUMP=y
CONFIG_ARCH_SUPPORTS_CRASH_DUMP=y
CONFIG_ARCH_DEFAULT_CRASH_DUMP=y
CONFIG_ARCH_SUPPORTS_CRASH_HOTPLUG=y
CONFIG_PHYSICAL_START=0x1000000
# CONFIG_RELOCATABLE is not set
CONFIG_PHYSICAL_ALIGN=0x1000000
# CONFIG_ADDRESS_MASKING is not set
CONFIG_HOTPLUG_CPU=y
# CONFIG_COMPAT_VDSO is not set
# CONFIG_LEGACY_VSYSCALL_XONLY is not set
CONFIG_LEGACY_VSYSCALL_NONE=y
# CONFIG_CMDLINE_BOOL is not set
# CONFIG_MODIFY_LDT_SYSCALL is not set
# CONFIG_STRICT_SIGALTSTACK_SIZE is not set
CONFIG_HAVE_LIVEPATCH=y
CONFIG_LIVEPATCH=y
# CONFIG_X86_BUS_LOCK_DETECT is not set
# end of Processor type and features

CONFIG_FUNCTION_PADDING_CFI=11
CONFIG_FUNCTION_PADDING_BYTES=16
# CONFIG_CPU_MITIGATIONS is not set
CONFIG_ARCH_HAS_ADD_PAGES=y

#
# Power management and ACPI options
#
# CONFIG_SUSPEND is not set
# CONFIG_HIBERNATION is not set
# CONFIG_PM is not set
CONFIG_ARCH_SUPPORTS_ACPI=y
CONFIG_ACPI=y
CONFIG_ACPI_LEGACY_TABLES_LOOKUP=y
CONFIG_ARCH_MIGHT_HAVE_ACPI_PDC=y
CONFIG_ACPI_SYSTEM_POWER_STATES_SUPPORT=y
# CONFIG_ACPI_DEBUGGER is not set
# CONFIG_ACPI_SPCR_TABLE is not set
# CONFIG_ACPI_FPDT is not set
CONFIG_ACPI_LPIT=y
CONFIG_ACPI_REV_OVERRIDE_POSSIBLE=y
# CONFIG_ACPI_EC is not set
# CONFIG_ACPI_AC is not set
# CONFIG_ACPI_BATTERY is not set
# CONFIG_ACPI_BUTTON is not set
# CONFIG_ACPI_TINY_POWER_BUTTON is not set
# CONFIG_ACPI_DOCK is not set
# CONFIG_ACPI_PROCESSOR is not set
CONFIG_ARCH_HAS_ACPI_TABLE_UPGRADE=y
CONFIG_ACPI_TABLE_UPGRADE=y
# CONFIG_ACPI_DEBUG is not set
# CONFIG_ACPI_PCI_SLOT is not set
# CONFIG_ACPI_CONTAINER is not set
CONFIG_ACPI_HOTPLUG_IOAPIC=y
# CONFIG_ACPI_HED is not set
# CONFIG_ACPI_REDUCED_HARDWARE_ONLY is not set
# CONFIG_ACPI_NFIT is not set
CONFIG_HAVE_ACPI_APEI=y
CONFIG_HAVE_ACPI_APEI_NMI=y
# CONFIG_ACPI_APEI is not set
# CONFIG_ACPI_DPTF is not set
# CONFIG_ACPI_CONFIGFS is not set
# CONFIG_ACPI_PFRUT is not set
# CONFIG_ACPI_FFH is not set
# CONFIG_PMIC_OPREGION is not set
CONFIG_X86_PM_TIMER=y

#
# CPU Frequency scaling
#
# CONFIG_CPU_FREQ is not set
# end of CPU Frequency scaling

#
# CPU Idle
#
CONFIG_CPU_IDLE=y
CONFIG_CPU_IDLE_GOV_LADDER=y
CONFIG_CPU_IDLE_GOV_MENU=y
# CONFIG_CPU_IDLE_GOV_TEO is not set
# end of CPU Idle

# CONFIG_INTEL_IDLE is not set
# end of Power management and ACPI options

#
# Bus options (PCI etc.)
#
CONFIG_PCI_DIRECT=y
# CONFIG_PCI_MMCONFIG is not set
# CONFIG_PCI_CNB20LE_QUIRK is not set
# CONFIG_ISA_BUS is not set
# CONFIG_ISA_DMA_API is not set
CONFIG_AMD_NB=y
# end of Bus options (PCI etc.)

#
# Binary Emulations
#
CONFIG_IA32_EMULATION=y
# CONFIG_IA32_EMULATION_DEFAULT_DISABLED is not set
# CONFIG_X86_X32_ABI is not set
CONFIG_COMPAT_32=y
CONFIG_COMPAT=y
CONFIG_COMPAT_FOR_U64_ALIGNMENT=y
# end of Binary Emulations

CONFIG_VIRTUALIZATION=y
# CONFIG_KVM is not set
CONFIG_AS_AVX512=y
CONFIG_AS_SHA1_NI=y
CONFIG_AS_SHA256_NI=y
CONFIG_ARCH_CONFIGURES_CPU_MITIGATIONS=y

#
# General architecture-dependent options
#
CONFIG_HOTPLUG_SMT=y
CONFIG_HOTPLUG_CORE_SYNC=y
CONFIG_HOTPLUG_CORE_SYNC_DEAD=y
CONFIG_HOTPLUG_CORE_SYNC_FULL=y
CONFIG_HOTPLUG_SPLIT_STARTUP=y
CONFIG_HOTPLUG_PARALLEL=y
CONFIG_GENERIC_ENTRY=y
CONFIG_KPROBES=y
CONFIG_JUMP_LABEL=y
# CONFIG_STATIC_KEYS_SELFTEST is not set
# CONFIG_STATIC_CALL_SELFTEST is not set
CONFIG_OPTPROBES=y
CONFIG_KPROBES_ON_FTRACE=y
CONFIG_UPROBES=y
CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS=y
CONFIG_ARCH_USE_BUILTIN_BSWAP=y
CONFIG_KRETPROBES=y
CONFIG_KRETPROBE_ON_RETHOOK=y
CONFIG_HAVE_IOREMAP_PROT=y
CONFIG_HAVE_KPROBES=y
CONFIG_HAVE_KRETPROBES=y
CONFIG_HAVE_OPTPROBES=y
CONFIG_HAVE_KPROBES_ON_FTRACE=y
CONFIG_ARCH_CORRECT_STACKTRACE_ON_KRETPROBE=y
CONFIG_HAVE_FUNCTION_ERROR_INJECTION=y
CONFIG_HAVE_NMI=y
CONFIG_TRACE_IRQFLAGS_SUPPORT=y
CONFIG_TRACE_IRQFLAGS_NMI_SUPPORT=y
CONFIG_HAVE_ARCH_TRACEHOOK=y
CONFIG_HAVE_DMA_CONTIGUOUS=y
CONFIG_GENERIC_SMP_IDLE_THREAD=y
CONFIG_ARCH_HAS_FORTIFY_SOURCE=y
CONFIG_ARCH_HAS_SET_MEMORY=y
CONFIG_ARCH_HAS_SET_DIRECT_MAP=y
CONFIG_ARCH_HAS_CPU_FINALIZE_INIT=y
CONFIG_HAVE_ARCH_THREAD_STRUCT_WHITELIST=y
CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT=y
CONFIG_ARCH_WANTS_NO_INSTR=y
CONFIG_HAVE_ASM_MODVERSIONS=y
CONFIG_HAVE_REGS_AND_STACK_ACCESS_API=y
CONFIG_HAVE_RSEQ=y
CONFIG_HAVE_RUST=y
CONFIG_HAVE_FUNCTION_ARG_ACCESS_API=y
CONFIG_HAVE_HW_BREAKPOINT=y
CONFIG_HAVE_MIXED_BREAKPOINTS_REGS=y
CONFIG_HAVE_USER_RETURN_NOTIFIER=y
CONFIG_HAVE_PERF_EVENTS_NMI=y
CONFIG_HAVE_HARDLOCKUP_DETECTOR_PERF=y
CONFIG_HAVE_PERF_REGS=y
CONFIG_HAVE_PERF_USER_STACK_DUMP=y
CONFIG_HAVE_ARCH_JUMP_LABEL=y
CONFIG_HAVE_ARCH_JUMP_LABEL_RELATIVE=y
CONFIG_MMU_GATHER_MERGE_VMAS=y
CONFIG_MMU_LAZY_TLB_REFCOUNT=y
CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG=y
CONFIG_ARCH_HAVE_EXTRA_ELF_NOTES=y
CONFIG_ARCH_HAS_NMI_SAFE_THIS_CPU_OPS=y
CONFIG_HAVE_ALIGNED_STRUCT_PAGE=y
CONFIG_HAVE_CMPXCHG_LOCAL=y
CONFIG_HAVE_CMPXCHG_DOUBLE=y
CONFIG_ARCH_WANT_COMPAT_IPC_PARSE_VERSION=y
CONFIG_ARCH_WANT_OLD_COMPAT_IPC=y
CONFIG_HAVE_ARCH_SECCOMP=y
CONFIG_HAVE_ARCH_SECCOMP_FILTER=y
CONFIG_SECCOMP=y
CONFIG_SECCOMP_FILTER=y
# CONFIG_SECCOMP_CACHE_DEBUG is not set
CONFIG_HAVE_ARCH_STACKLEAK=y
CONFIG_HAVE_STACKPROTECTOR=y
# CONFIG_STACKPROTECTOR is not set
CONFIG_ARCH_SUPPORTS_LTO_CLANG=y
CONFIG_ARCH_SUPPORTS_LTO_CLANG_THIN=y
CONFIG_LTO_NONE=y
CONFIG_ARCH_SUPPORTS_AUTOFDO_CLANG=y
CONFIG_ARCH_SUPPORTS_PROPELLER_CLANG=y
CONFIG_ARCH_SUPPORTS_CFI_CLANG=y
CONFIG_HAVE_ARCH_WITHIN_STACK_FRAMES=y
CONFIG_HAVE_CONTEXT_TRACKING_USER=y
CONFIG_HAVE_CONTEXT_TRACKING_USER_OFFSTACK=y
CONFIG_HAVE_VIRT_CPU_ACCOUNTING_GEN=y
CONFIG_HAVE_IRQ_TIME_ACCOUNTING=y
CONFIG_HAVE_MOVE_PUD=y
CONFIG_HAVE_MOVE_PMD=y
CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE=y
CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD=y
CONFIG_HAVE_ARCH_HUGE_VMAP=y
CONFIG_HAVE_ARCH_HUGE_VMALLOC=y
CONFIG_ARCH_WANT_HUGE_PMD_SHARE=y
CONFIG_ARCH_WANT_PMD_MKWRITE=y
CONFIG_HAVE_ARCH_SOFT_DIRTY=y
CONFIG_HAVE_MOD_ARCH_SPECIFIC=y
CONFIG_MODULES_USE_ELF_RELA=y
CONFIG_ARCH_HAS_EXECMEM_ROX=y
CONFIG_HAVE_IRQ_EXIT_ON_IRQ_STACK=y
CONFIG_HAVE_SOFTIRQ_ON_OWN_STACK=y
CONFIG_SOFTIRQ_ON_OWN_STACK=y
CONFIG_ARCH_HAS_ELF_RANDOMIZE=y
CONFIG_HAVE_ARCH_MMAP_RND_BITS=y
CONFIG_HAVE_EXIT_THREAD=y
CONFIG_ARCH_MMAP_RND_BITS=28
CONFIG_HAVE_ARCH_MMAP_RND_COMPAT_BITS=y
CONFIG_ARCH_MMAP_RND_COMPAT_BITS=8
CONFIG_HAVE_ARCH_COMPAT_MMAP_BASES=y
CONFIG_HAVE_PAGE_SIZE_4KB=y
CONFIG_PAGE_SIZE_4KB=y
CONFIG_PAGE_SIZE_LESS_THAN_64KB=y
CONFIG_PAGE_SIZE_LESS_THAN_256KB=y
CONFIG_PAGE_SHIFT=12
CONFIG_HAVE_OBJTOOL=y
CONFIG_HAVE_JUMP_LABEL_HACK=y
CONFIG_HAVE_NOINSTR_HACK=y
CONFIG_HAVE_NOINSTR_VALIDATION=y
CONFIG_HAVE_UACCESS_VALIDATION=y
CONFIG_HAVE_STACK_VALIDATION=y
CONFIG_HAVE_RELIABLE_STACKTRACE=y
CONFIG_OLD_SIGSUSPEND3=y
CONFIG_COMPAT_OLD_SIGACTION=y
CONFIG_COMPAT_32BIT_TIME=y
CONFIG_ARCH_SUPPORTS_RT=y
CONFIG_HAVE_ARCH_VMAP_STACK=y
CONFIG_VMAP_STACK=y
CONFIG_HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET=y
# CONFIG_RANDOMIZE_KSTACK_OFFSET is not set
CONFIG_ARCH_HAS_STRICT_KERNEL_RWX=y
CONFIG_STRICT_KERNEL_RWX=y
CONFIG_ARCH_HAS_STRICT_MODULE_RWX=y
CONFIG_STRICT_MODULE_RWX=y
CONFIG_HAVE_ARCH_PREL32_RELOCATIONS=y
# CONFIG_LOCK_EVENT_COUNTS is not set
CONFIG_ARCH_HAS_MEM_ENCRYPT=y
CONFIG_HAVE_STATIC_CALL=y
CONFIG_HAVE_STATIC_CALL_INLINE=y
CONFIG_HAVE_PREEMPT_DYNAMIC=y
CONFIG_HAVE_PREEMPT_DYNAMIC_CALL=y
CONFIG_ARCH_WANT_LD_ORPHAN_WARN=y
CONFIG_ARCH_SUPPORTS_DEBUG_PAGEALLOC=y
CONFIG_ARCH_SUPPORTS_PAGE_TABLE_CHECK=y
CONFIG_ARCH_HAS_ELFCORE_COMPAT=y
CONFIG_ARCH_HAS_PARANOID_L1D_FLUSH=y
CONFIG_DYNAMIC_SIGFRAME=y
CONFIG_ARCH_HAS_HW_PTE_YOUNG=y
CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG=y
CONFIG_ARCH_HAS_KERNEL_FPU_SUPPORT=y

#
# GCOV-based kernel profiling
#
CONFIG_ARCH_HAS_GCOV_PROFILE_ALL=y
# end of GCOV-based kernel profiling

CONFIG_HAVE_GCC_PLUGINS=y
CONFIG_FUNCTION_ALIGNMENT_4B=y
CONFIG_FUNCTION_ALIGNMENT_16B=y
CONFIG_FUNCTION_ALIGNMENT=16
# end of General architecture-dependent options

CONFIG_RT_MUTEXES=y
CONFIG_MODULES=y
# CONFIG_MODULE_DEBUG is not set
CONFIG_MODULE_FORCE_LOAD=y
CONFIG_MODULE_UNLOAD=y
CONFIG_MODULE_FORCE_UNLOAD=y
# CONFIG_MODULE_UNLOAD_TAINT_TRACKING is not set
# CONFIG_MODVERSIONS is not set
# CONFIG_MODULE_SRCVERSION_ALL is not set
# CONFIG_MODULE_SIG is not set
# CONFIG_MODULE_COMPRESS is not set
# CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS is not set
CONFIG_MODPROBE_PATH="/sbin/modprobe"
# CONFIG_TRIM_UNUSED_KSYMS is not set
CONFIG_MODULES_TREE_LOOKUP=y
CONFIG_BLOCK=y
# CONFIG_BLOCK_LEGACY_AUTOLOAD is not set
# CONFIG_BLK_DEV_BSGLIB is not set
# CONFIG_BLK_DEV_INTEGRITY is not set
# CONFIG_BLK_DEV_WRITE_MOUNTED is not set
# CONFIG_BLK_DEV_ZONED is not set
# CONFIG_BLK_WBT is not set
# CONFIG_BLK_DEBUG_FS is not set
# CONFIG_BLK_INLINE_ENCRYPTION is not set

#
# Partition Types
#
# CONFIG_PARTITION_ADVANCED is not set
CONFIG_MSDOS_PARTITION=y
CONFIG_EFI_PARTITION=y
# end of Partition Types

CONFIG_BLK_MQ_PCI=y
CONFIG_BLK_MQ_VIRTIO=y

#
# IO Schedulers
#
# CONFIG_MQ_IOSCHED_DEADLINE is not set
# CONFIG_MQ_IOSCHED_KYBER is not set
# CONFIG_IOSCHED_BFQ is not set
# end of IO Schedulers

CONFIG_PADATA=y
CONFIG_UNINLINE_SPIN_UNLOCK=y
CONFIG_ARCH_SUPPORTS_ATOMIC_RMW=y
CONFIG_MUTEX_SPIN_ON_OWNER=y
CONFIG_RWSEM_SPIN_ON_OWNER=y
CONFIG_LOCK_SPIN_ON_OWNER=y
CONFIG_ARCH_USE_QUEUED_SPINLOCKS=y
CONFIG_QUEUED_SPINLOCKS=y
CONFIG_ARCH_USE_QUEUED_RWLOCKS=y
CONFIG_QUEUED_RWLOCKS=y
CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE=y
CONFIG_ARCH_HAS_SYNC_CORE_BEFORE_USERMODE=y
CONFIG_ARCH_HAS_SYSCALL_WRAPPER=y

#
# Executable file formats
#
CONFIG_BINFMT_ELF=y
CONFIG_COMPAT_BINFMT_ELF=y
CONFIG_ELFCORE=y
# CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS is not set
CONFIG_BINFMT_SCRIPT=y
# CONFIG_BINFMT_MISC is not set
CONFIG_COREDUMP=y
# end of Executable file formats

#
# Memory Management options
#
CONFIG_SWAP=y
# CONFIG_ZSWAP is not set

#
# Slab allocator options
#
CONFIG_SLUB=y
CONFIG_SLUB_TINY=y
CONFIG_SLAB_MERGE_DEFAULT=y
# end of Slab allocator options

# CONFIG_SHUFFLE_PAGE_ALLOCATOR is not set
# CONFIG_COMPAT_BRK is not set
CONFIG_SPARSEMEM=y
CONFIG_SPARSEMEM_EXTREME=y
CONFIG_SPARSEMEM_VMEMMAP_ENABLE=y
CONFIG_SPARSEMEM_VMEMMAP=y
CONFIG_ARCH_WANT_OPTIMIZE_DAX_VMEMMAP=y
CONFIG_ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP=y
CONFIG_HAVE_GUP_FAST=y
CONFIG_ARCH_ENABLE_MEMORY_HOTPLUG=y
# CONFIG_MEMORY_HOTPLUG is not set
CONFIG_ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE=y
CONFIG_SPLIT_PTE_PTLOCKS=y
CONFIG_ARCH_ENABLE_SPLIT_PMD_PTLOCK=y
CONFIG_SPLIT_PMD_PTLOCKS=y
CONFIG_MEMORY_BALLOON=y
# CONFIG_BALLOON_COMPACTION is not set
CONFIG_COMPACTION=y
CONFIG_COMPACT_UNEVICTABLE_DEFAULT=1
CONFIG_PAGE_REPORTING=y
CONFIG_MIGRATION=y
CONFIG_ARCH_ENABLE_HUGEPAGE_MIGRATION=y
CONFIG_ARCH_ENABLE_THP_MIGRATION=y
CONFIG_PCP_BATCH_SCALE_MAX=5
CONFIG_PHYS_ADDR_T_64BIT=y
# CONFIG_KSM is not set
CONFIG_DEFAULT_MMAP_MIN_ADDR=4096
CONFIG_ARCH_WANT_GENERAL_HUGETLB=y
CONFIG_ARCH_WANTS_THP_SWAP=y
CONFIG_TRANSPARENT_HUGEPAGE=y
CONFIG_TRANSPARENT_HUGEPAGE_ALWAYS=y
# CONFIG_TRANSPARENT_HUGEPAGE_MADVISE is not set
# CONFIG_TRANSPARENT_HUGEPAGE_NEVER is not set
CONFIG_THP_SWAP=y
# CONFIG_READ_ONLY_THP_FOR_FS is not set
CONFIG_PGTABLE_HAS_HUGE_LEAVES=y
CONFIG_ARCH_SUPPORTS_HUGE_PFNMAP=y
CONFIG_ARCH_SUPPORTS_PMD_PFNMAP=y
CONFIG_ARCH_SUPPORTS_PUD_PFNMAP=y
CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK=y
CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK=y
CONFIG_HAVE_SETUP_PER_CPU_AREA=y
# CONFIG_CMA is not set
CONFIG_MEM_SOFT_DIRTY=y
CONFIG_GENERIC_EARLY_IOREMAP=y
# CONFIG_DEFERRED_STRUCT_PAGE_INIT is not set
# CONFIG_IDLE_PAGE_TRACKING is not set
CONFIG_ARCH_HAS_CACHE_LINE_SIZE=y
CONFIG_ARCH_HAS_CURRENT_STACK_POINTER=y
CONFIG_ARCH_HAS_PTE_DEVMAP=y
CONFIG_ARCH_HAS_ZONE_DMA_SET=y
CONFIG_ZONE_DMA=y
CONFIG_ZONE_DMA32=y
CONFIG_ARCH_USES_PG_ARCH_2=y
CONFIG_VM_EVENT_COUNTERS=y
# CONFIG_PERCPU_STATS is not set
# CONFIG_GUP_TEST is not set
# CONFIG_DMAPOOL_TEST is not set
CONFIG_ARCH_HAS_PTE_SPECIAL=y
CONFIG_MEMFD_CREATE=y
CONFIG_SECRETMEM=y
CONFIG_ANON_VMA_NAME=y
CONFIG_HAVE_ARCH_USERFAULTFD_WP=y
CONFIG_HAVE_ARCH_USERFAULTFD_MINOR=y
CONFIG_USERFAULTFD=y
# CONFIG_PTE_MARKER_UFFD_WP is not set
# CONFIG_LRU_GEN is not set
CONFIG_ARCH_SUPPORTS_PER_VMA_LOCK=y
CONFIG_PER_VMA_LOCK=y
CONFIG_LOCK_MM_AND_FIND_VMA=y
CONFIG_EXECMEM=y

#
# Data Access Monitoring
#
# CONFIG_DAMON is not set
# end of Data Access Monitoring
# end of Memory Management options

CONFIG_NET=y
CONFIG_NET_INGRESS=y
CONFIG_NET_EGRESS=y
CONFIG_NET_XGRESS=y

#
# Networking options
#
CONFIG_PACKET=y
# CONFIG_PACKET_DIAG is not set
CONFIG_UNIX=y
CONFIG_AF_UNIX_OOB=y
# CONFIG_UNIX_DIAG is not set
# CONFIG_TLS is not set
# CONFIG_XFRM_USER is not set
# CONFIG_NET_KEY is not set
# CONFIG_XDP_SOCKETS is not set
CONFIG_INET=y
CONFIG_IP_MULTICAST=y
CONFIG_IP_ADVANCED_ROUTER=y
# CONFIG_IP_FIB_TRIE_STATS is not set
CONFIG_IP_MULTIPLE_TABLES=y
CONFIG_IP_ROUTE_MULTIPATH=y
CONFIG_IP_ROUTE_VERBOSE=y
# CONFIG_IP_PNP is not set
# CONFIG_NET_IPIP is not set
# CONFIG_NET_IPGRE_DEMUX is not set
CONFIG_IP_MROUTE_COMMON=y
CONFIG_IP_MROUTE=y
# CONFIG_IP_MROUTE_MULTIPLE_TABLES is not set
CONFIG_IP_PIMSM_V1=y
CONFIG_IP_PIMSM_V2=y
CONFIG_SYN_COOKIES=y
# CONFIG_NET_IPVTI is not set
# CONFIG_NET_FOU is not set
# CONFIG_INET_AH is not set
# CONFIG_INET_ESP is not set
# CONFIG_INET_IPCOMP is not set
CONFIG_INET_TABLE_PERTURB_ORDER=16
CONFIG_INET_DIAG=y
CONFIG_INET_TCP_DIAG=y
# CONFIG_INET_UDP_DIAG is not set
# CONFIG_INET_RAW_DIAG is not set
# CONFIG_INET_DIAG_DESTROY is not set
# CONFIG_TCP_CONG_ADVANCED is not set
CONFIG_TCP_CONG_CUBIC=y
CONFIG_DEFAULT_TCP_CONG="cubic"
# CONFIG_TCP_AO is not set
# CONFIG_TCP_MD5SIG is not set
# CONFIG_IPV6 is not set
# CONFIG_MPTCP is not set
CONFIG_NETWORK_SECMARK=y
# CONFIG_NETWORK_PHY_TIMESTAMPING is not set
CONFIG_NETFILTER=y
CONFIG_NETFILTER_ADVANCED=y

#
# Core Netfilter Configuration
#
# CONFIG_NETFILTER_INGRESS is not set
# CONFIG_NETFILTER_EGRESS is not set
CONFIG_NETFILTER_BPF_LINK=y
# CONFIG_NETFILTER_NETLINK_ACCT is not set
# CONFIG_NETFILTER_NETLINK_QUEUE is not set
# CONFIG_NETFILTER_NETLINK_LOG is not set
# CONFIG_NETFILTER_NETLINK_OSF is not set
# CONFIG_NF_CONNTRACK is not set
# CONFIG_NF_LOG_SYSLOG is not set
# CONFIG_NF_TABLES is not set
# CONFIG_NETFILTER_XTABLES is not set
# end of Core Netfilter Configuration

# CONFIG_IP_SET is not set
# CONFIG_IP_VS is not set

#
# IP: Netfilter Configuration
#
# CONFIG_IP_NF_IPTABLES_LEGACY is not set
# CONFIG_NF_SOCKET_IPV4 is not set
# CONFIG_NF_TPROXY_IPV4 is not set
# CONFIG_NF_DUP_IPV4 is not set
# CONFIG_NF_LOG_ARP is not set
# CONFIG_NF_LOG_IPV4 is not set
# CONFIG_NF_REJECT_IPV4 is not set
# CONFIG_IP_NF_IPTABLES is not set
# end of IP: Netfilter Configuration

# CONFIG_IP_DCCP is not set
# CONFIG_IP_SCTP is not set
# CONFIG_RDS is not set
# CONFIG_TIPC is not set
# CONFIG_ATM is not set
# CONFIG_L2TP is not set
# CONFIG_BRIDGE is not set
# CONFIG_NET_DSA is not set
# CONFIG_VLAN_8021Q is not set
# CONFIG_LLC2 is not set
# CONFIG_ATALK is not set
# CONFIG_X25 is not set
# CONFIG_LAPB is not set
# CONFIG_PHONET is not set
# CONFIG_IEEE802154 is not set
CONFIG_NET_SCHED=y

#
# Queueing/Scheduling
#
# CONFIG_NET_SCH_HTB is not set
# CONFIG_NET_SCH_HFSC is not set
# CONFIG_NET_SCH_PRIO is not set
# CONFIG_NET_SCH_MULTIQ is not set
# CONFIG_NET_SCH_RED is not set
# CONFIG_NET_SCH_SFB is not set
# CONFIG_NET_SCH_SFQ is not set
# CONFIG_NET_SCH_TEQL is not set
# CONFIG_NET_SCH_TBF is not set
# CONFIG_NET_SCH_CBS is not set
# CONFIG_NET_SCH_ETF is not set
# CONFIG_NET_SCH_TAPRIO is not set
# CONFIG_NET_SCH_GRED is not set
# CONFIG_NET_SCH_NETEM is not set
# CONFIG_NET_SCH_DRR is not set
# CONFIG_NET_SCH_MQPRIO is not set
# CONFIG_NET_SCH_SKBPRIO is not set
# CONFIG_NET_SCH_CHOKE is not set
# CONFIG_NET_SCH_QFQ is not set
# CONFIG_NET_SCH_CODEL is not set
# CONFIG_NET_SCH_FQ_CODEL is not set
# CONFIG_NET_SCH_CAKE is not set
# CONFIG_NET_SCH_FQ is not set
# CONFIG_NET_SCH_HHF is not set
# CONFIG_NET_SCH_PIE is not set
# CONFIG_NET_SCH_INGRESS is not set
# CONFIG_NET_SCH_PLUG is not set
# CONFIG_NET_SCH_ETS is not set
# CONFIG_NET_SCH_DEFAULT is not set

#
# Classification
#
CONFIG_NET_CLS=y
# CONFIG_NET_CLS_BASIC is not set
# CONFIG_NET_CLS_ROUTE4 is not set
# CONFIG_NET_CLS_FW is not set
# CONFIG_NET_CLS_U32 is not set
# CONFIG_NET_CLS_FLOW is not set
# CONFIG_NET_CLS_CGROUP is not set
# CONFIG_NET_CLS_BPF is not set
# CONFIG_NET_CLS_FLOWER is not set
# CONFIG_NET_CLS_MATCHALL is not set
# CONFIG_NET_EMATCH is not set
CONFIG_NET_CLS_ACT=y
# CONFIG_NET_ACT_POLICE is not set
# CONFIG_NET_ACT_GACT is not set
# CONFIG_NET_ACT_MIRRED is not set
# CONFIG_NET_ACT_SAMPLE is not set
# CONFIG_NET_ACT_NAT is not set
# CONFIG_NET_ACT_PEDIT is not set
# CONFIG_NET_ACT_SIMP is not set
# CONFIG_NET_ACT_SKBEDIT is not set
# CONFIG_NET_ACT_CSUM is not set
# CONFIG_NET_ACT_MPLS is not set
# CONFIG_NET_ACT_VLAN is not set
# CONFIG_NET_ACT_BPF is not set
# CONFIG_NET_ACT_SKBMOD is not set
# CONFIG_NET_ACT_IFE is not set
# CONFIG_NET_ACT_TUNNEL_KEY is not set
# CONFIG_NET_ACT_GATE is not set
# CONFIG_NET_TC_SKB_EXT is not set
CONFIG_NET_SCH_FIFO=y
# CONFIG_DCB is not set
# CONFIG_BATMAN_ADV is not set
# CONFIG_OPENVSWITCH is not set
# CONFIG_VSOCKETS is not set
# CONFIG_NETLINK_DIAG is not set
# CONFIG_MPLS is not set
# CONFIG_NET_NSH is not set
# CONFIG_HSR is not set
# CONFIG_NET_SWITCHDEV is not set
# CONFIG_NET_L3_MASTER_DEV is not set
# CONFIG_QRTR is not set
# CONFIG_NET_NCSI is not set
# CONFIG_PCPU_DEV_REFCNT is not set
CONFIG_MAX_SKB_FRAGS=17
CONFIG_RPS=y
CONFIG_RFS_ACCEL=y
CONFIG_SOCK_RX_QUEUE_MAPPING=y
CONFIG_XPS=y
# CONFIG_CGROUP_NET_PRIO is not set
# CONFIG_CGROUP_NET_CLASSID is not set
CONFIG_NET_RX_BUSY_POLL=y
CONFIG_BQL=y
CONFIG_NET_FLOW_LIMIT=y

#
# Network testing
#
# CONFIG_NET_PKTGEN is not set
# CONFIG_NET_DROP_MONITOR is not set
# end of Network testing
# end of Networking options

# CONFIG_HAMRADIO is not set
# CONFIG_CAN is not set
# CONFIG_BT is not set
# CONFIG_AF_RXRPC is not set
# CONFIG_AF_KCM is not set
# CONFIG_MCTP is not set
CONFIG_FIB_RULES=y
# CONFIG_WIRELESS is not set
# CONFIG_RFKILL is not set
CONFIG_NET_9P=y
# CONFIG_NET_9P_FD is not set
CONFIG_NET_9P_VIRTIO=y
# CONFIG_NET_9P_DEBUG is not set
# CONFIG_CAIF is not set
# CONFIG_CEPH_LIB is not set
# CONFIG_NFC is not set
# CONFIG_PSAMPLE is not set
# CONFIG_NET_IFE is not set
# CONFIG_LWTUNNEL is not set
CONFIG_NET_SOCK_MSG=y
CONFIG_PAGE_POOL=y
# CONFIG_PAGE_POOL_STATS is not set
CONFIG_FAILOVER=y
# CONFIG_ETHTOOL_NETLINK is not set

#
# Device Drivers
#
CONFIG_HAVE_EISA=y
# CONFIG_EISA is not set
CONFIG_HAVE_PCI=y
CONFIG_GENERIC_PCI_IOMAP=y
CONFIG_PCI=y
CONFIG_PCI_DOMAINS=y
CONFIG_PCIEPORTBUS=y
# CONFIG_PCIEAER is not set
# CONFIG_PCIEASPM is not set
# CONFIG_PCIE_PTM is not set
CONFIG_PCI_MSI=y
# CONFIG_PCI_QUIRKS is not set
# CONFIG_PCI_DEBUG is not set
# CONFIG_PCI_STUB is not set
CONFIG_PCI_LOCKLESS_CONFIG=y
# CONFIG_PCI_IOV is not set
# CONFIG_PCI_PRI is not set
# CONFIG_PCI_PASID is not set
# CONFIG_PCIE_TPH is not set
CONFIG_PCI_LABEL=y
# CONFIG_PCIE_BUS_TUNE_OFF is not set
CONFIG_PCIE_BUS_DEFAULT=y
# CONFIG_PCIE_BUS_SAFE is not set
# CONFIG_PCIE_BUS_PERFORMANCE is not set
# CONFIG_PCIE_BUS_PEER2PEER is not set
# CONFIG_VGA_ARB is not set
# CONFIG_HOTPLUG_PCI is not set

#
# PCI controller drivers
#
# CONFIG_VMD is not set

#
# Cadence-based PCIe controllers
#
# end of Cadence-based PCIe controllers

#
# DesignWare-based PCIe controllers
#
# CONFIG_PCI_MESON is not set
# CONFIG_PCIE_DW_PLAT_HOST is not set
# end of DesignWare-based PCIe controllers

#
# Mobiveil-based PCIe controllers
#
# end of Mobiveil-based PCIe controllers

#
# PLDA-based PCIe controllers
#
# end of PLDA-based PCIe controllers
# end of PCI controller drivers

#
# PCI Endpoint
#
# CONFIG_PCI_ENDPOINT is not set
# end of PCI Endpoint

#
# PCI switch controller drivers
#
# CONFIG_PCI_SW_SWITCHTEC is not set
# end of PCI switch controller drivers

# CONFIG_CXL_BUS is not set
# CONFIG_PCCARD is not set
# CONFIG_RAPIDIO is not set

#
# Generic Driver Options
#
# CONFIG_UEVENT_HELPER is not set
CONFIG_DEVTMPFS=y
# CONFIG_DEVTMPFS_MOUNT is not set
CONFIG_DEVTMPFS_SAFE=y
CONFIG_STANDALONE=y
CONFIG_PREVENT_FIRMWARE_BUILD=y

#
# Firmware loader
#
CONFIG_FW_LOADER=y
CONFIG_EXTRA_FIRMWARE=""
# CONFIG_FW_LOADER_USER_HELPER is not set
# CONFIG_FW_LOADER_COMPRESS is not set
# CONFIG_FW_UPLOAD is not set
# end of Firmware loader

# CONFIG_ALLOW_DEV_COREDUMP is not set
# CONFIG_DEBUG_DRIVER is not set
# CONFIG_DEBUG_DEVRES is not set
# CONFIG_DEBUG_TEST_DRIVER_REMOVE is not set
# CONFIG_TEST_ASYNC_DRIVER_PROBE is not set
CONFIG_GENERIC_CPU_DEVICES=y
CONFIG_GENERIC_CPU_AUTOPROBE=y
CONFIG_GENERIC_CPU_VULNERABILITIES=y
# CONFIG_FW_DEVLINK_SYNC_STATE_TIMEOUT is not set
# end of Generic Driver Options

#
# Bus devices
#
# CONFIG_MHI_BUS is not set
# CONFIG_MHI_BUS_EP is not set
# end of Bus devices

#
# Cache Drivers
#
# end of Cache Drivers

# CONFIG_CONNECTOR is not set

#
# Firmware Drivers
#

#
# ARM System Control and Management Interface Protocol
#
# end of ARM System Control and Management Interface Protocol

# CONFIG_EDD is not set
# CONFIG_FIRMWARE_MEMMAP is not set
# CONFIG_FW_CFG_SYSFS is not set
# CONFIG_SYSFB_SIMPLEFB is not set
# CONFIG_GOOGLE_FIRMWARE is not set

#
# Qualcomm firmware drivers
#
# end of Qualcomm firmware drivers

#
# Tegra firmware driver
#
# end of Tegra firmware driver
# end of Firmware Drivers

# CONFIG_GNSS is not set
# CONFIG_MTD is not set
# CONFIG_OF is not set
CONFIG_ARCH_MIGHT_HAVE_PC_PARPORT=y
# CONFIG_PARPORT is not set
CONFIG_PNP=y
# CONFIG_PNP_DEBUG_MESSAGES is not set

#
# Protocols
#
CONFIG_PNPACPI=y
CONFIG_BLK_DEV=y
# CONFIG_BLK_DEV_NULL_BLK is not set
# CONFIG_BLK_DEV_PCIESSD_MTIP32XX is not set
# CONFIG_ZRAM is not set
CONFIG_BLK_DEV_LOOP=y
CONFIG_BLK_DEV_LOOP_MIN_COUNT=8
# CONFIG_BLK_DEV_DRBD is not set
# CONFIG_BLK_DEV_NBD is not set
# CONFIG_BLK_DEV_RAM is not set
# CONFIG_ATA_OVER_ETH is not set
CONFIG_VIRTIO_BLK=y
# CONFIG_BLK_DEV_RBD is not set
# CONFIG_BLK_DEV_UBLK is not set

#
# NVME Support
#
# CONFIG_BLK_DEV_NVME is not set
# CONFIG_NVME_FC is not set
# CONFIG_NVME_TCP is not set
# end of NVME Support

#
# Misc devices
#
# CONFIG_DUMMY_IRQ is not set
# CONFIG_IBM_ASM is not set
# CONFIG_PHANTOM is not set
# CONFIG_TIFM_CORE is not set
# CONFIG_ENCLOSURE_SERVICES is not set
# CONFIG_HP_ILO is not set
# CONFIG_SRAM is not set
# CONFIG_DW_XDATA_PCIE is not set
# CONFIG_PCI_ENDPOINT_TEST is not set
# CONFIG_XILINX_SDFEC is not set
# CONFIG_NSM is not set
# CONFIG_MCHP_LAN966X_PCI is not set
# CONFIG_C2PORT is not set

#
# EEPROM support
#
# CONFIG_EEPROM_93CX6 is not set
# end of EEPROM support

# CONFIG_CB710_CORE is not set

#
# Altera FPGA firmware download module (requires I2C)
#
# CONFIG_INTEL_MEI is not set
# CONFIG_VMWARE_VMCI is not set
# CONFIG_GENWQE is not set
# CONFIG_ECHO is not set
# CONFIG_BCM_VK is not set
# CONFIG_MISC_ALCOR_PCI is not set
# CONFIG_MISC_RTSX_PCI is not set
# CONFIG_PVPANIC is not set
# end of Misc devices

#
# SCSI device support
#
CONFIG_SCSI_MOD=y
# CONFIG_RAID_ATTRS is not set
# CONFIG_SCSI is not set
# end of SCSI device support

# CONFIG_ATA is not set
# CONFIG_MD is not set
# CONFIG_TARGET_CORE is not set
# CONFIG_FUSION is not set

#
# IEEE 1394 (FireWire) support
#
# CONFIG_FIREWIRE is not set
# CONFIG_FIREWIRE_NOSY is not set
# end of IEEE 1394 (FireWire) support

# CONFIG_MACINTOSH_DRIVERS is not set
CONFIG_NETDEVICES=y
CONFIG_NET_CORE=y
# CONFIG_BONDING is not set
# CONFIG_DUMMY is not set
# CONFIG_WIREGUARD is not set
# CONFIG_EQUALIZER is not set
# CONFIG_NET_TEAM is not set
# CONFIG_MACVLAN is not set
# CONFIG_IPVLAN is not set
# CONFIG_VXLAN is not set
# CONFIG_GENEVE is not set
# CONFIG_BAREUDP is not set
# CONFIG_GTP is not set
# CONFIG_PFCP is not set
# CONFIG_AMT is not set
# CONFIG_MACSEC is not set
# CONFIG_NETCONSOLE is not set
# CONFIG_TUN is not set
# CONFIG_TUN_VNET_CROSS_LE is not set
# CONFIG_VETH is not set
CONFIG_VIRTIO_NET=y
# CONFIG_NLMON is not set
# CONFIG_NETKIT is not set
# CONFIG_ARCNET is not set
# CONFIG_ETHERNET is not set
# CONFIG_FDDI is not set
# CONFIG_HIPPI is not set
# CONFIG_PHYLIB is not set
# CONFIG_MDIO_DEVICE is not set

#
# PCS device drivers
#
# CONFIG_PCS_XPCS is not set
# end of PCS device drivers

# CONFIG_PPP is not set
# CONFIG_SLIP is not set

#
# Host-side USB support is needed for USB Network Adapter support
#
# CONFIG_WLAN is not set
# CONFIG_WAN is not set

#
# Wireless WAN
#
# CONFIG_WWAN is not set
# end of Wireless WAN

# CONFIG_VMXNET3 is not set
# CONFIG_FUJITSU_ES is not set
# CONFIG_NETDEVSIM is not set
CONFIG_NET_FAILOVER=y
# CONFIG_ISDN is not set

#
# Input device support
#
CONFIG_INPUT=y
# CONFIG_INPUT_FF_MEMLESS is not set
# CONFIG_INPUT_SPARSEKMAP is not set
# CONFIG_INPUT_MATRIXKMAP is not set

#
# Userland interfaces
#
# CONFIG_INPUT_MOUSEDEV is not set
# CONFIG_INPUT_JOYDEV is not set
# CONFIG_INPUT_EVDEV is not set
# CONFIG_INPUT_EVBUG is not set

#
# Input Device Drivers
#
# CONFIG_INPUT_KEYBOARD is not set
# CONFIG_INPUT_MOUSE is not set
# CONFIG_INPUT_JOYSTICK is not set
# CONFIG_INPUT_TABLET is not set
# CONFIG_INPUT_TOUCHSCREEN is not set
# CONFIG_INPUT_MISC is not set
# CONFIG_RMI4_CORE is not set

#
# Hardware I/O ports
#
# CONFIG_SERIO is not set
CONFIG_ARCH_MIGHT_HAVE_PC_SERIO=y
# CONFIG_GAMEPORT is not set
# end of Hardware I/O ports
# end of Input device support

#
# Character devices
#
CONFIG_TTY=y
# CONFIG_VT is not set
CONFIG_UNIX98_PTYS=y
# CONFIG_LEGACY_PTYS is not set
# CONFIG_LEGACY_TIOCSTI is not set
CONFIG_LDISC_AUTOLOAD=y

#
# Serial drivers
#
CONFIG_SERIAL_EARLYCON=y
CONFIG_SERIAL_8250=y
# CONFIG_SERIAL_8250_DEPRECATED_OPTIONS is not set
# CONFIG_SERIAL_8250_PNP is not set
# CONFIG_SERIAL_8250_16550A_VARIANTS is not set
# CONFIG_SERIAL_8250_FINTEK is not set
CONFIG_SERIAL_8250_CONSOLE=y
# CONFIG_SERIAL_8250_PCI is not set
# CONFIG_SERIAL_8250_EXAR is not set
CONFIG_SERIAL_8250_NR_UARTS=4
CONFIG_SERIAL_8250_RUNTIME_UARTS=4
# CONFIG_SERIAL_8250_EXTENDED is not set
# CONFIG_SERIAL_8250_PCI1XXXX is not set
# CONFIG_SERIAL_8250_DW is not set
# CONFIG_SERIAL_8250_RT288X is not set
# CONFIG_SERIAL_8250_LPSS is not set
# CONFIG_SERIAL_8250_MID is not set
# CONFIG_SERIAL_8250_PERICOM is not set

#
# Non-8250 serial port support
#
# CONFIG_SERIAL_UARTLITE is not set
CONFIG_SERIAL_CORE=y
CONFIG_SERIAL_CORE_CONSOLE=y
# CONFIG_SERIAL_JSM is not set
# CONFIG_SERIAL_LANTIQ is not set
# CONFIG_SERIAL_SCCNXP is not set
# CONFIG_SERIAL_ALTERA_JTAGUART is not set
# CONFIG_SERIAL_ALTERA_UART is not set
# CONFIG_SERIAL_ARC is not set
# CONFIG_SERIAL_RP2 is not set
# CONFIG_SERIAL_FSL_LPUART is not set
# CONFIG_SERIAL_FSL_LINFLEXUART is not set
# CONFIG_SERIAL_SPRD is not set
# end of Serial drivers

# CONFIG_SERIAL_NONSTANDARD is not set
# CONFIG_N_GSM is not set
# CONFIG_NOZOMI is not set
# CONFIG_NULL_TTY is not set
CONFIG_HVC_DRIVER=y
# CONFIG_SERIAL_DEV_BUS is not set
# CONFIG_TTY_PRINTK is not set
CONFIG_VIRTIO_CONSOLE=y
# CONFIG_IPMI_HANDLER is not set
# CONFIG_HW_RANDOM is not set
# CONFIG_APPLICOM is not set
# CONFIG_MWAVE is not set
CONFIG_DEVMEM=y
# CONFIG_NVRAM is not set
CONFIG_DEVPORT=y
# CONFIG_HPET is not set
# CONFIG_HANGCHECK_TIMER is not set
# CONFIG_TCG_TPM is not set
# CONFIG_TELCLOCK is not set
# CONFIG_XILLYBUS is not set
# end of Character devices

#
# I2C support
#
# CONFIG_I2C is not set
# end of I2C support

# CONFIG_I3C is not set
# CONFIG_SPI is not set
# CONFIG_SPMI is not set
# CONFIG_HSI is not set
# CONFIG_PPS is not set

#
# PTP clock support
#
# CONFIG_PTP_1588_CLOCK is not set
CONFIG_PTP_1588_CLOCK_OPTIONAL=y

#
# Enable PHYLIB and NETWORK_PHY_TIMESTAMPING to see the additional clocks.
#
# end of PTP clock support

# CONFIG_PINCTRL is not set
# CONFIG_GPIOLIB is not set
# CONFIG_W1 is not set
# CONFIG_POWER_RESET is not set
# CONFIG_POWER_SEQUENCING is not set
# CONFIG_POWER_SUPPLY is not set
# CONFIG_HWMON is not set
# CONFIG_THERMAL is not set
# CONFIG_WATCHDOG is not set
CONFIG_SSB_POSSIBLE=y
# CONFIG_SSB is not set
CONFIG_BCMA_POSSIBLE=y
# CONFIG_BCMA is not set

#
# Multifunction device drivers
#
# CONFIG_MFD_CGBC is not set
# CONFIG_MFD_MADERA is not set
# CONFIG_MFD_INTEL_QUARK_I2C_GPIO is not set
# CONFIG_LPC_ICH is not set
# CONFIG_LPC_SCH is not set
# CONFIG_MFD_INTEL_LPSS_ACPI is not set
# CONFIG_MFD_INTEL_LPSS_PCI is not set
# CONFIG_MFD_JANZ_CMODIO is not set
# CONFIG_MFD_KEMPLD is not set
# CONFIG_MFD_MT6397 is not set
# CONFIG_MFD_RDC321X is not set
# CONFIG_MFD_SM501 is not set
# CONFIG_MFD_SYSCON is not set
# CONFIG_MFD_TQMX86 is not set
# CONFIG_MFD_VX855 is not set
# end of Multifunction device drivers

# CONFIG_REGULATOR is not set
# CONFIG_RC_CORE is not set

#
# CEC support
#
# CONFIG_MEDIA_CEC_SUPPORT is not set
# end of CEC support

# CONFIG_MEDIA_SUPPORT is not set

#
# Graphics support
#
# CONFIG_AUXDISPLAY is not set
# CONFIG_AGP is not set
# CONFIG_VGA_SWITCHEROO is not set
# CONFIG_DRM is not set

#
# Frame buffer Devices
#
# CONFIG_FB is not set
# end of Frame buffer Devices

#
# Backlight & LCD device support
#
# CONFIG_LCD_CLASS_DEVICE is not set
# CONFIG_BACKLIGHT_CLASS_DEVICE is not set
# end of Backlight & LCD device support
# end of Graphics support

# CONFIG_SOUND is not set
# CONFIG_HID_SUPPORT is not set
CONFIG_USB_OHCI_LITTLE_ENDIAN=y
# CONFIG_USB_SUPPORT is not set
# CONFIG_MMC is not set
# CONFIG_MEMSTICK is not set
# CONFIG_NEW_LEDS is not set
# CONFIG_ACCESSIBILITY is not set
# CONFIG_INFINIBAND is not set
CONFIG_EDAC_ATOMIC_SCRUB=y
CONFIG_EDAC_SUPPORT=y
CONFIG_RTC_LIB=y
CONFIG_RTC_MC146818_LIB=y
# CONFIG_RTC_CLASS is not set
# CONFIG_DMADEVICES is not set

#
# DMABUF options
#
# CONFIG_SYNC_FILE is not set
# CONFIG_DMABUF_HEAPS is not set
# end of DMABUF options

# CONFIG_UIO is not set
# CONFIG_VFIO is not set
# CONFIG_VIRT_DRIVERS is not set
CONFIG_VIRTIO_ANCHOR=y
CONFIG_VIRTIO=y
CONFIG_VIRTIO_PCI_LIB=y
CONFIG_VIRTIO_PCI_LIB_LEGACY=y
CONFIG_VIRTIO_MENU=y
CONFIG_VIRTIO_PCI=y
CONFIG_VIRTIO_PCI_ADMIN_LEGACY=y
CONFIG_VIRTIO_PCI_LEGACY=y
CONFIG_VIRTIO_BALLOON=y
# CONFIG_VIRTIO_INPUT is not set
CONFIG_VIRTIO_MMIO=y
# CONFIG_VIRTIO_MMIO_CMDLINE_DEVICES is not set
# CONFIG_VIRTIO_DEBUG is not set
# CONFIG_VDPA is not set
# CONFIG_VHOST_MENU is not set

#
# Microsoft Hyper-V guest support
#
# end of Microsoft Hyper-V guest support

# CONFIG_GREYBUS is not set
# CONFIG_COMEDI is not set
# CONFIG_STAGING is not set
# CONFIG_GOLDFISH is not set
# CONFIG_CHROME_PLATFORMS is not set
# CONFIG_CZNIC_PLATFORMS is not set
# CONFIG_MELLANOX_PLATFORM is not set
# CONFIG_SURFACE_PLATFORMS is not set
# CONFIG_X86_PLATFORM_DEVICES is not set
CONFIG_HAVE_CLK=y
CONFIG_HAVE_CLK_PREPARE=y
CONFIG_COMMON_CLK=y
# CONFIG_XILINX_VCU is not set
# CONFIG_HWSPINLOCK is not set

#
# Clock Source drivers
#
CONFIG_CLKEVT_I8253=y
CONFIG_CLKBLD_I8253=y
# end of Clock Source drivers

# CONFIG_MAILBOX is not set
# CONFIG_IOMMU_SUPPORT is not set

#
# Remoteproc drivers
#
# CONFIG_REMOTEPROC is not set
# end of Remoteproc drivers

#
# Rpmsg drivers
#
# CONFIG_RPMSG_VIRTIO is not set
# end of Rpmsg drivers

#
# SOC (System On Chip) specific Drivers
#

#
# Amlogic SoC drivers
#
# end of Amlogic SoC drivers

#
# Broadcom SoC drivers
#
# end of Broadcom SoC drivers

#
# NXP/Freescale QorIQ SoC drivers
#
# end of NXP/Freescale QorIQ SoC drivers

#
# fujitsu SoC drivers
#
# end of fujitsu SoC drivers

#
# i.MX SoC drivers
#
# end of i.MX SoC drivers

#
# Enable LiteX SoC Builder specific drivers
#
# end of Enable LiteX SoC Builder specific drivers

# CONFIG_WPCM450_SOC is not set

#
# Qualcomm SoC drivers
#
# end of Qualcomm SoC drivers

# CONFIG_SOC_TI is not set

#
# Xilinx SoC drivers
#
# end of Xilinx SoC drivers
# end of SOC (System On Chip) specific Drivers

#
# PM Domains
#

#
# Amlogic PM Domains
#
# end of Amlogic PM Domains

#
# Broadcom PM Domains
#
# end of Broadcom PM Domains

#
# i.MX PM Domains
#
# end of i.MX PM Domains

#
# Qualcomm PM Domains
#
# end of Qualcomm PM Domains
# end of PM Domains

# CONFIG_PM_DEVFREQ is not set
# CONFIG_EXTCON is not set
# CONFIG_MEMORY is not set
# CONFIG_IIO is not set
# CONFIG_NTB is not set
# CONFIG_PWM is not set

#
# IRQ chip support
#
# CONFIG_LAN966X_OIC is not set
# end of IRQ chip support

# CONFIG_IPACK_BUS is not set
# CONFIG_RESET_CONTROLLER is not set

#
# PHY Subsystem
#
# CONFIG_GENERIC_PHY is not set
# CONFIG_PHY_CAN_TRANSCEIVER is not set

#
# PHY drivers for Broadcom platforms
#
# CONFIG_BCM_KONA_USB2_PHY is not set
# end of PHY drivers for Broadcom platforms

# CONFIG_PHY_PXA_28NM_HSIC is not set
# CONFIG_PHY_PXA_28NM_USB2 is not set
# CONFIG_PHY_INTEL_LGM_EMMC is not set
# end of PHY Subsystem

# CONFIG_POWERCAP is not set
# CONFIG_MCB is not set

#
# Performance monitor support
#
# CONFIG_DWC_PCIE_PMU is not set
# end of Performance monitor support

# CONFIG_RAS is not set
# CONFIG_USB4 is not set

#
# Android
#
# CONFIG_ANDROID_BINDER_IPC is not set
# end of Android

# CONFIG_LIBNVDIMM is not set
# CONFIG_DAX is not set
# CONFIG_NVMEM is not set

#
# HW tracing support
#
# CONFIG_STM is not set
# CONFIG_INTEL_TH is not set
# end of HW tracing support

# CONFIG_FPGA is not set
# CONFIG_TEE is not set
# CONFIG_SIOX is not set
# CONFIG_SLIMBUS is not set
# CONFIG_INTERCONNECT is not set
# CONFIG_COUNTER is not set
# CONFIG_PECI is not set
# CONFIG_HTE is not set
# end of Device Drivers

#
# File systems
#
CONFIG_DCACHE_WORD_ACCESS=y
CONFIG_VALIDATE_FS_PARSER=y
CONFIG_FS_IOMAP=y
CONFIG_BUFFER_HEAD=y
# CONFIG_EXT2_FS is not set
CONFIG_EXT3_FS=y
# CONFIG_EXT3_FS_POSIX_ACL is not set
# CONFIG_EXT3_FS_SECURITY is not set
CONFIG_EXT4_FS=y
# CONFIG_EXT4_USE_FOR_EXT2 is not set
# CONFIG_EXT4_FS_POSIX_ACL is not set
# CONFIG_EXT4_FS_SECURITY is not set
# CONFIG_EXT4_DEBUG is not set
CONFIG_JBD2=y
# CONFIG_JBD2_DEBUG is not set
CONFIG_FS_MBCACHE=y
# CONFIG_JFS_FS is not set
# CONFIG_XFS_FS is not set
# CONFIG_GFS2_FS is not set
# CONFIG_BTRFS_FS is not set
# CONFIG_NILFS2_FS is not set
# CONFIG_F2FS_FS is not set
# CONFIG_BCACHEFS_FS is not set
CONFIG_FS_POSIX_ACL=y
# CONFIG_EXPORTFS_BLOCK_OPS is not set
CONFIG_FILE_LOCKING=y
# CONFIG_FS_ENCRYPTION is not set
# CONFIG_FS_VERITY is not set
# CONFIG_DNOTIFY is not set
# CONFIG_INOTIFY_USER is not set
# CONFIG_FANOTIFY is not set
# CONFIG_QUOTA is not set
# CONFIG_AUTOFS_FS is not set
CONFIG_FUSE_FS=y
# CONFIG_CUSE is not set
# CONFIG_VIRTIO_FS is not set
# CONFIG_FUSE_PASSTHROUGH is not set
# CONFIG_OVERLAY_FS is not set

#
# Caches
#
CONFIG_NETFS_SUPPORT=y
# CONFIG_NETFS_STATS is not set
# CONFIG_NETFS_DEBUG is not set
# CONFIG_FSCACHE is not set
# end of Caches

#
# CD-ROM/DVD Filesystems
#
# CONFIG_ISO9660_FS is not set
# CONFIG_UDF_FS is not set
# end of CD-ROM/DVD Filesystems

#
# DOS/FAT/EXFAT/NT Filesystems
#
# CONFIG_MSDOS_FS is not set
# CONFIG_VFAT_FS is not set
# CONFIG_EXFAT_FS is not set
# CONFIG_NTFS3_FS is not set
# CONFIG_NTFS_FS is not set
# end of DOS/FAT/EXFAT/NT Filesystems

#
# Pseudo filesystems
#
CONFIG_PROC_FS=y
CONFIG_PROC_KCORE=y
CONFIG_PROC_SYSCTL=y
CONFIG_PROC_PAGE_MONITOR=y
CONFIG_PROC_CHILDREN=y
CONFIG_PROC_PID_ARCH_STATUS=y
CONFIG_KERNFS=y
CONFIG_SYSFS=y
CONFIG_TMPFS=y
CONFIG_TMPFS_POSIX_ACL=y
CONFIG_TMPFS_XATTR=y
# CONFIG_TMPFS_INODE64 is not set
# CONFIG_TMPFS_QUOTA is not set
CONFIG_HUGETLBFS=y
# CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP_DEFAULT_ON is not set
CONFIG_HUGETLB_PAGE=y
CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP=y
CONFIG_HUGETLB_PMD_PAGE_TABLE_SHARING=y
CONFIG_ARCH_HAS_GIGANTIC_PAGE=y
# CONFIG_CONFIGFS_FS is not set
# end of Pseudo filesystems

# CONFIG_MISC_FILESYSTEMS is not set
CONFIG_NETWORK_FILESYSTEMS=y
# CONFIG_NFS_FS is not set
# CONFIG_CEPH_FS is not set
# CONFIG_CIFS is not set
# CONFIG_SMB_SERVER is not set
# CONFIG_CODA_FS is not set
# CONFIG_AFS_FS is not set
CONFIG_9P_FS=y
# CONFIG_9P_FS_POSIX_ACL is not set
# CONFIG_9P_FS_SECURITY is not set
CONFIG_NLS=y
CONFIG_NLS_DEFAULT="iso8859-1"
# CONFIG_NLS_CODEPAGE_437 is not set
# CONFIG_NLS_CODEPAGE_737 is not set
# CONFIG_NLS_CODEPAGE_775 is not set
# CONFIG_NLS_CODEPAGE_850 is not set
# CONFIG_NLS_CODEPAGE_852 is not set
# CONFIG_NLS_CODEPAGE_855 is not set
# CONFIG_NLS_CODEPAGE_857 is not set
# CONFIG_NLS_CODEPAGE_860 is not set
# CONFIG_NLS_CODEPAGE_861 is not set
# CONFIG_NLS_CODEPAGE_862 is not set
# CONFIG_NLS_CODEPAGE_863 is not set
# CONFIG_NLS_CODEPAGE_864 is not set
# CONFIG_NLS_CODEPAGE_865 is not set
# CONFIG_NLS_CODEPAGE_866 is not set
# CONFIG_NLS_CODEPAGE_869 is not set
# CONFIG_NLS_CODEPAGE_936 is not set
# CONFIG_NLS_CODEPAGE_950 is not set
# CONFIG_NLS_CODEPAGE_932 is not set
# CONFIG_NLS_CODEPAGE_949 is not set
# CONFIG_NLS_CODEPAGE_874 is not set
# CONFIG_NLS_ISO8859_8 is not set
# CONFIG_NLS_CODEPAGE_1250 is not set
# CONFIG_NLS_CODEPAGE_1251 is not set
# CONFIG_NLS_ASCII is not set
# CONFIG_NLS_ISO8859_1 is not set
# CONFIG_NLS_ISO8859_2 is not set
# CONFIG_NLS_ISO8859_3 is not set
# CONFIG_NLS_ISO8859_4 is not set
# CONFIG_NLS_ISO8859_5 is not set
# CONFIG_NLS_ISO8859_6 is not set
# CONFIG_NLS_ISO8859_7 is not set
# CONFIG_NLS_ISO8859_9 is not set
# CONFIG_NLS_ISO8859_13 is not set
# CONFIG_NLS_ISO8859_14 is not set
# CONFIG_NLS_ISO8859_15 is not set
# CONFIG_NLS_KOI8_R is not set
# CONFIG_NLS_KOI8_U is not set
# CONFIG_NLS_MAC_ROMAN is not set
# CONFIG_NLS_MAC_CELTIC is not set
# CONFIG_NLS_MAC_CENTEURO is not set
# CONFIG_NLS_MAC_CROATIAN is not set
# CONFIG_NLS_MAC_CYRILLIC is not set
# CONFIG_NLS_MAC_GAELIC is not set
# CONFIG_NLS_MAC_GREEK is not set
# CONFIG_NLS_MAC_ICELAND is not set
# CONFIG_NLS_MAC_INUIT is not set
# CONFIG_NLS_MAC_ROMANIAN is not set
# CONFIG_NLS_MAC_TURKISH is not set
# CONFIG_NLS_UTF8 is not set
# CONFIG_UNICODE is not set
CONFIG_IO_WQ=y
# end of File systems

#
# Security options
#
# CONFIG_KEYS is not set
# CONFIG_SECURITY_DMESG_RESTRICT is not set
CONFIG_PROC_MEM_ALWAYS_FORCE=y
# CONFIG_PROC_MEM_FORCE_PTRACE is not set
# CONFIG_PROC_MEM_NO_FORCE is not set
# CONFIG_SECURITY is not set
# CONFIG_SECURITYFS is not set
# CONFIG_HARDENED_USERCOPY is not set
# CONFIG_FORTIFY_SOURCE is not set
# CONFIG_STATIC_USERMODEHELPER is not set
CONFIG_DEFAULT_SECURITY_DAC=y
CONFIG_LSM="yama,loadpin,safesetid,integrity,selinux,smack,tomoyo,apparmor"

#
# Kernel hardening options
#

#
# Memory initialization
#
CONFIG_INIT_STACK_NONE=y
# CONFIG_INIT_ON_ALLOC_DEFAULT_ON is not set
# CONFIG_INIT_ON_FREE_DEFAULT_ON is not set
# end of Memory initialization

#
# Hardening of kernel data structures
#
# CONFIG_LIST_HARDENED is not set
# CONFIG_BUG_ON_DATA_CORRUPTION is not set
# end of Hardening of kernel data structures

CONFIG_RANDSTRUCT_NONE=y
# end of Kernel hardening options
# end of Security options

CONFIG_CRYPTO=y

#
# Crypto core or helper
#
CONFIG_CRYPTO_ALGAPI=y
CONFIG_CRYPTO_ALGAPI2=y
CONFIG_CRYPTO_HASH=y
CONFIG_CRYPTO_HASH2=y
# CONFIG_CRYPTO_MANAGER is not set
# CONFIG_CRYPTO_USER is not set
CONFIG_CRYPTO_MANAGER_DISABLE_TESTS=y
# CONFIG_CRYPTO_NULL is not set
# CONFIG_CRYPTO_PCRYPT is not set
# CONFIG_CRYPTO_CRYPTD is not set
# CONFIG_CRYPTO_AUTHENC is not set
# CONFIG_CRYPTO_TEST is not set
# end of Crypto core or helper

#
# Public-key cryptography
#
# CONFIG_CRYPTO_RSA is not set
# CONFIG_CRYPTO_DH is not set
# CONFIG_CRYPTO_ECDH is not set
# CONFIG_CRYPTO_ECDSA is not set
# CONFIG_CRYPTO_ECRDSA is not set
# CONFIG_CRYPTO_CURVE25519 is not set
# end of Public-key cryptography

#
# Block ciphers
#
CONFIG_CRYPTO_AES=y
# CONFIG_CRYPTO_AES_TI is not set
# CONFIG_CRYPTO_ARIA is not set
# CONFIG_CRYPTO_BLOWFISH is not set
# CONFIG_CRYPTO_CAMELLIA is not set
# CONFIG_CRYPTO_CAST5 is not set
# CONFIG_CRYPTO_CAST6 is not set
# CONFIG_CRYPTO_DES is not set
# CONFIG_CRYPTO_FCRYPT is not set
# CONFIG_CRYPTO_SERPENT is not set
# CONFIG_CRYPTO_SM4_GENERIC is not set
# CONFIG_CRYPTO_TWOFISH is not set
# end of Block ciphers

#
# Length-preserving ciphers and modes
#
# CONFIG_CRYPTO_ADIANTUM is not set
# CONFIG_CRYPTO_CHACHA20 is not set
# CONFIG_CRYPTO_CBC is not set
# CONFIG_CRYPTO_CTR is not set
# CONFIG_CRYPTO_CTS is not set
# CONFIG_CRYPTO_ECB is not set
# CONFIG_CRYPTO_HCTR2 is not set
# CONFIG_CRYPTO_KEYWRAP is not set
# CONFIG_CRYPTO_LRW is not set
# CONFIG_CRYPTO_PCBC is not set
# CONFIG_CRYPTO_XTS is not set
# end of Length-preserving ciphers and modes

#
# AEAD (authenticated encryption with associated data) ciphers
#
# CONFIG_CRYPTO_AEGIS128 is not set
# CONFIG_CRYPTO_CHACHA20POLY1305 is not set
# CONFIG_CRYPTO_CCM is not set
# CONFIG_CRYPTO_GCM is not set
# CONFIG_CRYPTO_SEQIV is not set
# CONFIG_CRYPTO_ECHAINIV is not set
# CONFIG_CRYPTO_ESSIV is not set
# end of AEAD (authenticated encryption with associated data) ciphers

#
# Hashes, digests, and MACs
#
# CONFIG_CRYPTO_BLAKE2B is not set
# CONFIG_CRYPTO_CMAC is not set
# CONFIG_CRYPTO_GHASH is not set
# CONFIG_CRYPTO_HMAC is not set
# CONFIG_CRYPTO_MD4 is not set
# CONFIG_CRYPTO_MD5 is not set
# CONFIG_CRYPTO_MICHAEL_MIC is not set
# CONFIG_CRYPTO_POLY1305 is not set
# CONFIG_CRYPTO_RMD160 is not set
# CONFIG_CRYPTO_SHA1 is not set
# CONFIG_CRYPTO_SHA256 is not set
# CONFIG_CRYPTO_SHA512 is not set
# CONFIG_CRYPTO_SHA3 is not set
# CONFIG_CRYPTO_SM3_GENERIC is not set
# CONFIG_CRYPTO_STREEBOG is not set
# CONFIG_CRYPTO_VMAC is not set
# CONFIG_CRYPTO_WP512 is not set
# CONFIG_CRYPTO_XCBC is not set
# CONFIG_CRYPTO_XXHASH is not set
# end of Hashes, digests, and MACs

#
# CRCs (cyclic redundancy checks)
#
CONFIG_CRYPTO_CRC32C=y
# CONFIG_CRYPTO_CRC32 is not set
# CONFIG_CRYPTO_CRCT10DIF is not set
# end of CRCs (cyclic redundancy checks)

#
# Compression
#
# CONFIG_CRYPTO_DEFLATE is not set
# CONFIG_CRYPTO_LZO is not set
# CONFIG_CRYPTO_842 is not set
# CONFIG_CRYPTO_LZ4 is not set
# CONFIG_CRYPTO_LZ4HC is not set
# CONFIG_CRYPTO_ZSTD is not set
# end of Compression

#
# Random number generation
#
# CONFIG_CRYPTO_ANSI_CPRNG is not set
# CONFIG_CRYPTO_DRBG_MENU is not set
# CONFIG_CRYPTO_JITTERENTROPY is not set
# end of Random number generation

#
# Userspace interface
#
# CONFIG_CRYPTO_USER_API_HASH is not set
# CONFIG_CRYPTO_USER_API_SKCIPHER is not set
# CONFIG_CRYPTO_USER_API_RNG is not set
# CONFIG_CRYPTO_USER_API_AEAD is not set
# end of Userspace interface

#
# Accelerated Cryptographic Algorithms for CPU (x86)
#
# CONFIG_CRYPTO_CURVE25519_X86 is not set
# CONFIG_CRYPTO_AES_NI_INTEL is not set
# CONFIG_CRYPTO_BLOWFISH_X86_64 is not set
# CONFIG_CRYPTO_CAMELLIA_X86_64 is not set
# CONFIG_CRYPTO_CAMELLIA_AESNI_AVX_X86_64 is not set
# CONFIG_CRYPTO_CAMELLIA_AESNI_AVX2_X86_64 is not set
# CONFIG_CRYPTO_CAST5_AVX_X86_64 is not set
# CONFIG_CRYPTO_CAST6_AVX_X86_64 is not set
# CONFIG_CRYPTO_DES3_EDE_X86_64 is not set
# CONFIG_CRYPTO_SERPENT_SSE2_X86_64 is not set
# CONFIG_CRYPTO_SERPENT_AVX_X86_64 is not set
# CONFIG_CRYPTO_SERPENT_AVX2_X86_64 is not set
# CONFIG_CRYPTO_SM4_AESNI_AVX_X86_64 is not set
# CONFIG_CRYPTO_SM4_AESNI_AVX2_X86_64 is not set
# CONFIG_CRYPTO_TWOFISH_X86_64 is not set
# CONFIG_CRYPTO_TWOFISH_X86_64_3WAY is not set
# CONFIG_CRYPTO_TWOFISH_AVX_X86_64 is not set
# CONFIG_CRYPTO_ARIA_AESNI_AVX_X86_64 is not set
# CONFIG_CRYPTO_ARIA_AESNI_AVX2_X86_64 is not set
# CONFIG_CRYPTO_CHACHA20_X86_64 is not set
# CONFIG_CRYPTO_AEGIS128_AESNI_SSE2 is not set
# CONFIG_CRYPTO_NHPOLY1305_SSE2 is not set
# CONFIG_CRYPTO_NHPOLY1305_AVX2 is not set
# CONFIG_CRYPTO_BLAKE2S_X86 is not set
# CONFIG_CRYPTO_POLYVAL_CLMUL_NI is not set
# CONFIG_CRYPTO_POLY1305_X86_64 is not set
# CONFIG_CRYPTO_SHA1_SSSE3 is not set
# CONFIG_CRYPTO_SHA256_SSSE3 is not set
# CONFIG_CRYPTO_SHA512_SSSE3 is not set
# CONFIG_CRYPTO_SM3_AVX_X86_64 is not set
# CONFIG_CRYPTO_GHASH_CLMUL_NI_INTEL is not set
# CONFIG_CRYPTO_CRC32C_INTEL is not set
# CONFIG_CRYPTO_CRC32_PCLMUL is not set
# end of Accelerated Cryptographic Algorithms for CPU (x86)

# CONFIG_CRYPTO_HW is not set

#
# Certificates for signature checking
#
# end of Certificates for signature checking

CONFIG_BINARY_PRINTF=y

#
# Library routines
#
# CONFIG_PACKING is not set
CONFIG_BITREVERSE=y
CONFIG_GENERIC_STRNCPY_FROM_USER=y
CONFIG_GENERIC_STRNLEN_USER=y
CONFIG_GENERIC_NET_UTILS=y
# CONFIG_CORDIC is not set
# CONFIG_PRIME_NUMBERS is not set
CONFIG_RATIONAL=y
CONFIG_GENERIC_IOMAP=y
CONFIG_ARCH_USE_CMPXCHG_LOCKREF=y
CONFIG_ARCH_HAS_FAST_MULTIPLIER=y
CONFIG_ARCH_USE_SYM_ANNOTATIONS=y

#
# Crypto library routines
#
CONFIG_CRYPTO_LIB_UTILS=y
CONFIG_CRYPTO_LIB_AES=y
CONFIG_CRYPTO_LIB_BLAKE2S_GENERIC=y
# CONFIG_CRYPTO_LIB_CHACHA is not set
# CONFIG_CRYPTO_LIB_CURVE25519 is not set
CONFIG_CRYPTO_LIB_POLY1305_RSIZE=11
# CONFIG_CRYPTO_LIB_POLY1305 is not set
# CONFIG_CRYPTO_LIB_CHACHA20POLY1305 is not set
CONFIG_CRYPTO_LIB_SHA1=y
# end of Crypto library routines

# CONFIG_CRC_CCITT is not set
CONFIG_CRC16=y
# CONFIG_CRC_T10DIF is not set
# CONFIG_CRC64_ROCKSOFT is not set
# CONFIG_CRC_ITU_T is not set
CONFIG_CRC32=y
# CONFIG_CRC32_SELFTEST is not set
CONFIG_CRC32_SLICEBY8=y
# CONFIG_CRC32_SLICEBY4 is not set
# CONFIG_CRC32_SARWATE is not set
# CONFIG_CRC32_BIT is not set
# CONFIG_CRC64 is not set
# CONFIG_CRC4 is not set
# CONFIG_CRC7 is not set
# CONFIG_LIBCRC32C is not set
# CONFIG_CRC8 is not set
# CONFIG_RANDOM32_SELFTEST is not set
CONFIG_ZLIB_INFLATE=y
# CONFIG_XZ_DEC is not set
CONFIG_DECOMPRESS_GZIP=y
CONFIG_XARRAY_MULTI=y
CONFIG_HAS_IOMEM=y
CONFIG_HAS_IOPORT=y
CONFIG_HAS_IOPORT_MAP=y
CONFIG_HAS_DMA=y
CONFIG_NEED_SG_DMA_LENGTH=y
CONFIG_NEED_DMA_MAP_STATE=y
CONFIG_ARCH_DMA_ADDR_T_64BIT=y
CONFIG_SWIOTLB=y
# CONFIG_SWIOTLB_DYNAMIC is not set
CONFIG_DMA_NEED_SYNC=y
# CONFIG_DMA_API_DEBUG is not set
# CONFIG_DMA_MAP_BENCHMARK is not set
CONFIG_CPU_RMAP=y
CONFIG_DQL=y
CONFIG_GLOB=y
# CONFIG_GLOB_SELFTEST is not set
CONFIG_NLATTR=y
# CONFIG_IRQ_POLL is not set
CONFIG_DIMLIB=y
CONFIG_HAVE_GENERIC_VDSO=y
CONFIG_GENERIC_GETTIMEOFDAY=y
CONFIG_GENERIC_VDSO_TIME_NS=y
CONFIG_GENERIC_VDSO_OVERFLOW_PROTECT=y
CONFIG_VDSO_GETRANDOM=y
CONFIG_SG_POOL=y
CONFIG_ARCH_HAS_PMEM_API=y
CONFIG_ARCH_HAS_CPU_CACHE_INVALIDATE_MEMREGION=y
CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE=y
CONFIG_ARCH_HAS_COPY_MC=y
CONFIG_ARCH_STACKWALK=y
CONFIG_SBITMAP=y
# CONFIG_LWQ_TEST is not set
# end of Library routines

CONFIG_FIRMWARE_TABLE=y

#
# Kernel hacking
#

#
# printk and dmesg options
#
# CONFIG_PRINTK_TIME is not set
# CONFIG_PRINTK_CALLER is not set
# CONFIG_STACKTRACE_BUILD_ID is not set
CONFIG_CONSOLE_LOGLEVEL_DEFAULT=7
CONFIG_CONSOLE_LOGLEVEL_QUIET=4
CONFIG_MESSAGE_LOGLEVEL_DEFAULT=4
# CONFIG_BOOT_PRINTK_DELAY is not set
# CONFIG_DYNAMIC_DEBUG is not set
# CONFIG_DYNAMIC_DEBUG_CORE is not set
# CONFIG_SYMBOLIC_ERRNAME is not set
CONFIG_DEBUG_BUGVERBOSE=y
# end of printk and dmesg options

CONFIG_DEBUG_KERNEL=y
# CONFIG_DEBUG_MISC is not set

#
# Compile-time checks and compiler options
#
CONFIG_DEBUG_INFO=y
CONFIG_AS_HAS_NON_CONST_ULEB128=y
# CONFIG_DEBUG_INFO_NONE is not set
CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT=y
# CONFIG_DEBUG_INFO_DWARF4 is not set
# CONFIG_DEBUG_INFO_DWARF5 is not set
# CONFIG_DEBUG_INFO_REDUCED is not set
CONFIG_DEBUG_INFO_COMPRESSED_NONE=y
# CONFIG_DEBUG_INFO_SPLIT is not set
# CONFIG_GDB_SCRIPTS is not set
CONFIG_FRAME_WARN=2048
CONFIG_STRIP_ASM_SYMS=y
CONFIG_READABLE_ASM=y
# CONFIG_HEADERS_INSTALL is not set
# CONFIG_DEBUG_SECTION_MISMATCH is not set
CONFIG_SECTION_MISMATCH_WARN_ONLY=y
# CONFIG_DEBUG_FORCE_FUNCTION_ALIGN_64B is not set
CONFIG_OBJTOOL=y
CONFIG_VMLINUX_MAP=y
# CONFIG_BUILTIN_MODULE_RANGES is not set
# CONFIG_DEBUG_FORCE_WEAK_PER_CPU is not set
# end of Compile-time checks and compiler options

#
# Generic Kernel Debugging Instruments
#
CONFIG_MAGIC_SYSRQ=y
CONFIG_MAGIC_SYSRQ_DEFAULT_ENABLE=0x1
CONFIG_MAGIC_SYSRQ_SERIAL=y
CONFIG_MAGIC_SYSRQ_SERIAL_SEQUENCE=""
CONFIG_DEBUG_FS=y
CONFIG_DEBUG_FS_ALLOW_ALL=y
# CONFIG_DEBUG_FS_DISALLOW_MOUNT is not set
# CONFIG_DEBUG_FS_ALLOW_NONE is not set
CONFIG_HAVE_ARCH_KGDB=y
# CONFIG_KGDB is not set
CONFIG_ARCH_HAS_UBSAN=y
# CONFIG_UBSAN is not set
CONFIG_HAVE_ARCH_KCSAN=y
# end of Generic Kernel Debugging Instruments

#
# Networking Debugging
#
# CONFIG_NET_DEV_REFCNT_TRACKER is not set
# CONFIG_NET_NS_REFCNT_TRACKER is not set
# CONFIG_DEBUG_NET is not set
# CONFIG_DEBUG_NET_SMALL_RTNL is not set
# end of Networking Debugging

#
# Memory Debugging
#
CONFIG_PAGE_EXTENSION=y
# CONFIG_DEBUG_PAGEALLOC is not set
# CONFIG_PAGE_OWNER is not set
# CONFIG_PAGE_POISONING is not set
# CONFIG_DEBUG_PAGE_REF is not set
# CONFIG_DEBUG_RODATA_TEST is not set
CONFIG_ARCH_HAS_DEBUG_WX=y
# CONFIG_DEBUG_WX is not set
CONFIG_GENERIC_PTDUMP=y
CONFIG_PTDUMP_CORE=y
CONFIG_PTDUMP_DEBUGFS=y
CONFIG_HAVE_DEBUG_KMEMLEAK=y
# CONFIG_DEBUG_KMEMLEAK is not set
# CONFIG_PER_VMA_LOCK_STATS is not set
# CONFIG_DEBUG_OBJECTS is not set
# CONFIG_SHRINKER_DEBUG is not set
# CONFIG_DEBUG_STACK_USAGE is not set
# CONFIG_SCHED_STACK_END_CHECK is not set
CONFIG_ARCH_HAS_DEBUG_VM_PGTABLE=y
# CONFIG_DEBUG_VM is not set
# CONFIG_DEBUG_VM_PGTABLE is not set
CONFIG_ARCH_HAS_DEBUG_VIRTUAL=y
# CONFIG_DEBUG_VIRTUAL is not set
# CONFIG_DEBUG_MEMORY_INIT is not set
# CONFIG_DEBUG_PER_CPU_MAPS is not set
CONFIG_ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP=y
# CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP is not set
# CONFIG_MEM_ALLOC_PROFILING is not set
CONFIG_HAVE_ARCH_KASAN=y
CONFIG_HAVE_ARCH_KASAN_VMALLOC=y
CONFIG_CC_HAS_KASAN_GENERIC=y
CONFIG_HAVE_ARCH_KFENCE=y
# CONFIG_KFENCE is not set
CONFIG_HAVE_ARCH_KMSAN=y
# end of Memory Debugging

# CONFIG_DEBUG_SHIRQ is not set

#
# Debug Oops, Lockups and Hangs
#
# CONFIG_PANIC_ON_OOPS is not set
CONFIG_PANIC_ON_OOPS_VALUE=0
CONFIG_PANIC_TIMEOUT=0
CONFIG_LOCKUP_DETECTOR=y
CONFIG_SOFTLOCKUP_DETECTOR=y
# CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC is not set
CONFIG_HAVE_HARDLOCKUP_DETECTOR_BUDDY=y
CONFIG_HARDLOCKUP_DETECTOR=y
# CONFIG_HARDLOCKUP_DETECTOR_PREFER_BUDDY is not set
CONFIG_HARDLOCKUP_DETECTOR_PERF=y
# CONFIG_HARDLOCKUP_DETECTOR_BUDDY is not set
# CONFIG_HARDLOCKUP_DETECTOR_ARCH is not set
CONFIG_HARDLOCKUP_DETECTOR_COUNTS_HRTIMER=y
CONFIG_HARDLOCKUP_CHECK_TIMESTAMP=y
# CONFIG_BOOTPARAM_HARDLOCKUP_PANIC is not set
CONFIG_DETECT_HUNG_TASK=y
CONFIG_DEFAULT_HUNG_TASK_TIMEOUT=120
# CONFIG_BOOTPARAM_HUNG_TASK_PANIC is not set
# CONFIG_WQ_WATCHDOG is not set
# CONFIG_WQ_CPU_INTENSIVE_REPORT is not set
# CONFIG_TEST_LOCKUP is not set
# end of Debug Oops, Lockups and Hangs

#
# Scheduler Debugging
#
# CONFIG_SCHED_DEBUG is not set
# CONFIG_SCHEDSTATS is not set
# end of Scheduler Debugging

# CONFIG_DEBUG_PREEMPT is not set

#
# Lock Debugging (spinlocks, mutexes, etc...)
#
CONFIG_LOCK_DEBUGGING_SUPPORT=y
CONFIG_PROVE_LOCKING=y
CONFIG_PROVE_RAW_LOCK_NESTING=y
CONFIG_LOCK_STAT=y
CONFIG_DEBUG_RT_MUTEXES=y
CONFIG_DEBUG_SPINLOCK=y
CONFIG_DEBUG_MUTEXES=y
CONFIG_DEBUG_WW_MUTEX_SLOWPATH=y
CONFIG_DEBUG_RWSEMS=y
CONFIG_DEBUG_LOCK_ALLOC=y
CONFIG_LOCKDEP=y
CONFIG_LOCKDEP_BITS=15
CONFIG_LOCKDEP_CHAINS_BITS=16
CONFIG_LOCKDEP_STACK_TRACE_BITS=19
CONFIG_LOCKDEP_STACK_TRACE_HASH_BITS=14
CONFIG_LOCKDEP_CIRCULAR_QUEUE_BITS=12
# CONFIG_DEBUG_LOCKDEP is not set
CONFIG_DEBUG_ATOMIC_SLEEP=y
# CONFIG_DEBUG_LOCKING_API_SELFTESTS is not set
# CONFIG_LOCK_TORTURE_TEST is not set
# CONFIG_WW_MUTEX_SELFTEST is not set
# CONFIG_SCF_TORTURE_TEST is not set
# CONFIG_CSD_LOCK_WAIT_DEBUG is not set
# end of Lock Debugging (spinlocks, mutexes, etc...)

CONFIG_TRACE_IRQFLAGS=y
CONFIG_TRACE_IRQFLAGS_NMI=y
# CONFIG_NMI_CHECK_CPU is not set
# CONFIG_DEBUG_IRQFLAGS is not set
CONFIG_STACKTRACE=y
# CONFIG_WARN_ALL_UNSEEDED_RANDOM is not set
# CONFIG_DEBUG_KOBJECT is not set

#
# Debug kernel data structures
#
# CONFIG_DEBUG_LIST is not set
# CONFIG_DEBUG_PLIST is not set
# CONFIG_DEBUG_SG is not set
# CONFIG_DEBUG_NOTIFIERS is not set
# CONFIG_DEBUG_MAPLE_TREE is not set
# end of Debug kernel data structures

#
# RCU Debugging
#
CONFIG_PROVE_RCU=y
# CONFIG_RCU_SCALE_TEST is not set
# CONFIG_RCU_TORTURE_TEST is not set
# CONFIG_RCU_REF_SCALE_TEST is not set
CONFIG_RCU_CPU_STALL_TIMEOUT=60
CONFIG_RCU_EXP_CPU_STALL_TIMEOUT=0
CONFIG_RCU_CPU_STALL_CPUTIME=y
# CONFIG_RCU_TRACE is not set
# CONFIG_RCU_EQS_DEBUG is not set
# end of RCU Debugging

# CONFIG_DEBUG_WQ_FORCE_RR_CPU is not set
# CONFIG_CPU_HOTPLUG_STATE_CONTROL is not set
# CONFIG_LATENCYTOP is not set
# CONFIG_DEBUG_CGROUP_REF is not set
CONFIG_USER_STACKTRACE_SUPPORT=y
CONFIG_NOP_TRACER=y
CONFIG_HAVE_RETHOOK=y
CONFIG_RETHOOK=y
CONFIG_HAVE_FUNCTION_TRACER=y
CONFIG_HAVE_FUNCTION_GRAPH_TRACER=y
CONFIG_HAVE_FUNCTION_GRAPH_RETVAL=y
CONFIG_HAVE_DYNAMIC_FTRACE=y
CONFIG_HAVE_DYNAMIC_FTRACE_WITH_REGS=y
CONFIG_HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS=y
CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS=y
CONFIG_HAVE_DYNAMIC_FTRACE_NO_PATCHABLE=y
CONFIG_HAVE_FTRACE_MCOUNT_RECORD=y
CONFIG_HAVE_SYSCALL_TRACEPOINTS=y
CONFIG_HAVE_FENTRY=y
CONFIG_HAVE_OBJTOOL_MCOUNT=y
CONFIG_HAVE_OBJTOOL_NOP_MCOUNT=y
CONFIG_HAVE_C_RECORDMCOUNT=y
CONFIG_HAVE_BUILDTIME_MCOUNT_SORT=y
CONFIG_BUILDTIME_MCOUNT_SORT=y
CONFIG_TRACER_MAX_TRACE=y
CONFIG_TRACE_CLOCK=y
CONFIG_RING_BUFFER=y
CONFIG_EVENT_TRACING=y
CONFIG_CONTEXT_SWITCH_TRACER=y
CONFIG_RING_BUFFER_ALLOW_SWAP=y
CONFIG_PREEMPTIRQ_TRACEPOINTS=y
CONFIG_TRACING=y
CONFIG_GENERIC_TRACER=y
CONFIG_TRACING_SUPPORT=y
CONFIG_FTRACE=y
CONFIG_BOOTTIME_TRACING=y
CONFIG_FUNCTION_TRACER=y
CONFIG_FUNCTION_GRAPH_TRACER=y
CONFIG_FUNCTION_GRAPH_RETVAL=y
# CONFIG_FUNCTION_GRAPH_RETADDR is not set
CONFIG_DYNAMIC_FTRACE=y
CONFIG_DYNAMIC_FTRACE_WITH_REGS=y
CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS=y
CONFIG_DYNAMIC_FTRACE_WITH_ARGS=y
CONFIG_FPROBE=y
# CONFIG_FUNCTION_PROFILER is not set
# CONFIG_STACK_TRACER is not set
CONFIG_TRACE_PREEMPT_TOGGLE=y
CONFIG_IRQSOFF_TRACER=y
CONFIG_PREEMPT_TRACER=y
CONFIG_SCHED_TRACER=y
# CONFIG_HWLAT_TRACER is not set
# CONFIG_OSNOISE_TRACER is not set
# CONFIG_TIMERLAT_TRACER is not set
# CONFIG_MMIOTRACE is not set
CONFIG_FTRACE_SYSCALLS=y
CONFIG_TRACER_SNAPSHOT=y
CONFIG_TRACER_SNAPSHOT_PER_CPU_SWAP=y
CONFIG_BRANCH_PROFILE_NONE=y
# CONFIG_PROFILE_ANNOTATED_BRANCHES is not set
# CONFIG_PROFILE_ALL_BRANCHES is not set
# CONFIG_BLK_DEV_IO_TRACE is not set
CONFIG_FPROBE_EVENTS=y
CONFIG_KPROBE_EVENTS=y
# CONFIG_KPROBE_EVENTS_ON_NOTRACE is not set
CONFIG_UPROBE_EVENTS=y
CONFIG_BPF_EVENTS=y
CONFIG_DYNAMIC_EVENTS=y
CONFIG_PROBE_EVENTS=y
# CONFIG_BPF_KPROBE_OVERRIDE is not set
CONFIG_FTRACE_MCOUNT_RECORD=y
CONFIG_FTRACE_MCOUNT_USE_CC=y
# CONFIG_SYNTH_EVENTS is not set
CONFIG_USER_EVENTS=y
# CONFIG_HIST_TRIGGERS is not set
# CONFIG_TRACE_EVENT_INJECT is not set
# CONFIG_TRACEPOINT_BENCHMARK is not set
# CONFIG_RING_BUFFER_BENCHMARK is not set
# CONFIG_TRACE_EVAL_MAP_FILE is not set
# CONFIG_FTRACE_RECORD_RECURSION is not set
# CONFIG_FTRACE_VALIDATE_RCU_IS_WATCHING is not set
# CONFIG_FTRACE_STARTUP_TEST is not set
# CONFIG_FTRACE_SORT_STARTUP_TEST is not set
# CONFIG_RING_BUFFER_STARTUP_TEST is not set
# CONFIG_RING_BUFFER_VALIDATE_TIME_DELTAS is not set
# CONFIG_PREEMPTIRQ_DELAY_TEST is not set
# CONFIG_KPROBE_EVENT_GEN_TEST is not set
# CONFIG_RV is not set
# CONFIG_PROVIDE_OHCI1394_DMA_INIT is not set
# CONFIG_SAMPLES is not set
CONFIG_HAVE_SAMPLE_FTRACE_DIRECT=y
CONFIG_HAVE_SAMPLE_FTRACE_DIRECT_MULTI=y
CONFIG_ARCH_HAS_DEVMEM_IS_ALLOWED=y
# CONFIG_STRICT_DEVMEM is not set

#
# x86 Debugging
#
# CONFIG_X86_VERBOSE_BOOTUP is not set
CONFIG_EARLY_PRINTK=y
# CONFIG_EARLY_PRINTK_DBGP is not set
# CONFIG_EARLY_PRINTK_USB_XDBC is not set
# CONFIG_DEBUG_TLBFLUSH is not set
CONFIG_HAVE_MMIOTRACE_SUPPORT=y
# CONFIG_X86_DECODER_SELFTEST is not set
CONFIG_IO_DELAY_0X80=y
# CONFIG_IO_DELAY_0XED is not set
# CONFIG_IO_DELAY_UDELAY is not set
# CONFIG_IO_DELAY_NONE is not set
# CONFIG_DEBUG_BOOT_PARAMS is not set
# CONFIG_CPA_DEBUG is not set
# CONFIG_DEBUG_ENTRY is not set
# CONFIG_DEBUG_NMI_SELFTEST is not set
# CONFIG_X86_DEBUG_FPU is not set
# CONFIG_PUNIT_ATOM_DEBUG is not set
CONFIG_UNWINDER_ORC=y
# CONFIG_UNWINDER_FRAME_POINTER is not set
# CONFIG_UNWINDER_GUESS is not set
# end of x86 Debugging

#
# Kernel Testing and Coverage
#
# CONFIG_KUNIT is not set
# CONFIG_NOTIFIER_ERROR_INJECTION is not set
CONFIG_FUNCTION_ERROR_INJECTION=y
# CONFIG_FAULT_INJECTION is not set
CONFIG_ARCH_HAS_KCOV=y
# CONFIG_RUNTIME_TESTING_MENU is not set
CONFIG_ARCH_USE_MEMTEST=y
# CONFIG_MEMTEST is not set
# end of Kernel Testing and Coverage

#
# Rust hacking
#
# end of Rust hacking
# end of Kernel hacking

^ permalink raw reply	[flat|nested] 67+ messages in thread

* Re: [PATCH] x86/stackprotector: fix build failure with CONFIG_STACKPROTECTOR=n
  2024-12-06 14:21       ` Oleg Nesterov
@ 2024-12-06 14:37         ` Ard Biesheuvel
  2024-12-06 15:12           ` Brian Gerst
  0 siblings, 1 reply; 67+ messages in thread
From: Ard Biesheuvel @ 2024-12-06 14:37 UTC (permalink / raw)
  To: Oleg Nesterov
  Cc: Brian Gerst, linux-kernel, x86, Ingo Molnar, H . Peter Anvin,
	Thomas Gleixner, Borislav Petkov, Uros Bizjak, stable,
	Fangrui Song, Nathan Chancellor, Andy Lutomirski

On Fri, 6 Dec 2024 at 15:22, Oleg Nesterov <oleg@redhat.com> wrote:
>
> On 12/06, Ard Biesheuvel wrote:
> >
> > On Fri, 6 Dec 2024 at 13:32, Oleg Nesterov <oleg@redhat.com> wrote:
> > >
> > > +#ifdef CONFIG_STACKPROTECTOR
> > >  /* needed for Clang - see arch/x86/entry/entry.S */
> > >  PROVIDE(__ref_stack_chk_guard = __stack_chk_guard);
> > > +#endif
> > >
> > >  #ifdef CONFIG_X86_64
> > >  /*
> >
> > This shouldn't be necessary - PROVIDE() is only evaluated if a
> > reference exists to the symbol it defines.
> >
> > Also, I'm failing to reproduce this. Could you share your .config,
> > please, and the error that you get during the build?
>
> Please see the attached .config
>
> without the change above:
>
>         $ make bzImage
>           CALL    scripts/checksyscalls.sh
>           DESCEND objtool
>           INSTALL libsubcmd_headers
>           UPD     include/generated/utsversion.h
>           CC      init/version-timestamp.o
>           KSYMS   .tmp_vmlinux0.kallsyms.S
>           AS      .tmp_vmlinux0.kallsyms.o
>           LD      .tmp_vmlinux1
>         ./arch/x86/kernel/vmlinux.lds:154: undefined symbol `__stack_chk_guard' referenced in expression
>         scripts/Makefile.vmlinux:77: recipe for target 'vmlinux' failed
>         make[2]: *** [vmlinux] Error 1
>         /home/oleg/tmp/LINUX/Makefile:1225: recipe for target 'vmlinux' failed
>         make[1]: *** [vmlinux] Error 2
>         Makefile:251: recipe for target '__sub-make' failed
>         make: *** [__sub-make] Error 2
>
> perhaps this is because my toolchain is quite old,
>
>         $ ld -v
>         GNU ld version 2.25-17.fc23
>
> but according to Documentation/process/changes.rst
>
>         binutils               2.25             ld -v
>
> it is still supported.
>

We're about to bump the minimum toolchain requirements to GCC 8.1 (and
whichever version of binutils was current at the time), so you might
want to consider upgrading.

However, you are right that these are still supported today, and so we
need this fix this, especially because this has been backported to
older stable kernels too.

For the patch,

Acked-by: Ard Biesheuvel <ardb@kernel.org>

^ permalink raw reply	[flat|nested] 67+ messages in thread

* Re: [PATCH] x86/stackprotector: fix build failure with CONFIG_STACKPROTECTOR=n
  2024-12-06 14:37         ` Ard Biesheuvel
@ 2024-12-06 15:12           ` Brian Gerst
  2024-12-06 15:17             ` Ard Biesheuvel
  0 siblings, 1 reply; 67+ messages in thread
From: Brian Gerst @ 2024-12-06 15:12 UTC (permalink / raw)
  To: Ard Biesheuvel
  Cc: Oleg Nesterov, linux-kernel, x86, Ingo Molnar, H . Peter Anvin,
	Thomas Gleixner, Borislav Petkov, Uros Bizjak, stable,
	Fangrui Song, Nathan Chancellor, Andy Lutomirski

On Fri, Dec 6, 2024 at 9:37 AM Ard Biesheuvel <ardb@kernel.org> wrote:
>
> On Fri, 6 Dec 2024 at 15:22, Oleg Nesterov <oleg@redhat.com> wrote:
> >
> > On 12/06, Ard Biesheuvel wrote:
> > >
> > > On Fri, 6 Dec 2024 at 13:32, Oleg Nesterov <oleg@redhat.com> wrote:
> > > >
> > > > +#ifdef CONFIG_STACKPROTECTOR
> > > >  /* needed for Clang - see arch/x86/entry/entry.S */
> > > >  PROVIDE(__ref_stack_chk_guard = __stack_chk_guard);
> > > > +#endif
> > > >
> > > >  #ifdef CONFIG_X86_64
> > > >  /*
> > >
> > > This shouldn't be necessary - PROVIDE() is only evaluated if a
> > > reference exists to the symbol it defines.
> > >
> > > Also, I'm failing to reproduce this. Could you share your .config,
> > > please, and the error that you get during the build?
> >
> > Please see the attached .config
> >
> > without the change above:
> >
> >         $ make bzImage
> >           CALL    scripts/checksyscalls.sh
> >           DESCEND objtool
> >           INSTALL libsubcmd_headers
> >           UPD     include/generated/utsversion.h
> >           CC      init/version-timestamp.o
> >           KSYMS   .tmp_vmlinux0.kallsyms.S
> >           AS      .tmp_vmlinux0.kallsyms.o
> >           LD      .tmp_vmlinux1
> >         ./arch/x86/kernel/vmlinux.lds:154: undefined symbol `__stack_chk_guard' referenced in expression
> >         scripts/Makefile.vmlinux:77: recipe for target 'vmlinux' failed
> >         make[2]: *** [vmlinux] Error 1
> >         /home/oleg/tmp/LINUX/Makefile:1225: recipe for target 'vmlinux' failed
> >         make[1]: *** [vmlinux] Error 2
> >         Makefile:251: recipe for target '__sub-make' failed
> >         make: *** [__sub-make] Error 2
> >
> > perhaps this is because my toolchain is quite old,
> >
> >         $ ld -v
> >         GNU ld version 2.25-17.fc23
> >
> > but according to Documentation/process/changes.rst
> >
> >         binutils               2.25             ld -v
> >
> > it is still supported.
> >
>
> We're about to bump the minimum toolchain requirements to GCC 8.1 (and
> whichever version of binutils was current at the time), so you might
> want to consider upgrading.
>
> However, you are right that these are still supported today, and so we
> need this fix this, especially because this has been backported to
> older stable kernels too.
>
> For the patch,
>
> Acked-by: Ard Biesheuvel <ardb@kernel.org>

Using PROVIDES() is now unnecessary.


Brian Gerst

^ permalink raw reply	[flat|nested] 67+ messages in thread

* Re: [PATCH] x86/stackprotector: fix build failure with CONFIG_STACKPROTECTOR=n
  2024-12-06 15:12           ` Brian Gerst
@ 2024-12-06 15:17             ` Ard Biesheuvel
  2025-03-10 21:44               ` Borislav Petkov
  0 siblings, 1 reply; 67+ messages in thread
From: Ard Biesheuvel @ 2024-12-06 15:17 UTC (permalink / raw)
  To: Brian Gerst
  Cc: Oleg Nesterov, linux-kernel, x86, Ingo Molnar, H . Peter Anvin,
	Thomas Gleixner, Borislav Petkov, Uros Bizjak, stable,
	Fangrui Song, Nathan Chancellor, Andy Lutomirski

On Fri, 6 Dec 2024 at 16:12, Brian Gerst <brgerst@gmail.com> wrote:
>
> On Fri, Dec 6, 2024 at 9:37 AM Ard Biesheuvel <ardb@kernel.org> wrote:
> >
> > On Fri, 6 Dec 2024 at 15:22, Oleg Nesterov <oleg@redhat.com> wrote:
> > >
> > > On 12/06, Ard Biesheuvel wrote:
> > > >
> > > > On Fri, 6 Dec 2024 at 13:32, Oleg Nesterov <oleg@redhat.com> wrote:
> > > > >
> > > > > +#ifdef CONFIG_STACKPROTECTOR
> > > > >  /* needed for Clang - see arch/x86/entry/entry.S */
> > > > >  PROVIDE(__ref_stack_chk_guard = __stack_chk_guard);
> > > > > +#endif
> > > > >
> > > > >  #ifdef CONFIG_X86_64
> > > > >  /*
> > > >
> > > > This shouldn't be necessary - PROVIDE() is only evaluated if a
> > > > reference exists to the symbol it defines.
> > > >
> > > > Also, I'm failing to reproduce this. Could you share your .config,
> > > > please, and the error that you get during the build?
> > >
> > > Please see the attached .config
> > >
> > > without the change above:
> > >
> > >         $ make bzImage
> > >           CALL    scripts/checksyscalls.sh
> > >           DESCEND objtool
> > >           INSTALL libsubcmd_headers
> > >           UPD     include/generated/utsversion.h
> > >           CC      init/version-timestamp.o
> > >           KSYMS   .tmp_vmlinux0.kallsyms.S
> > >           AS      .tmp_vmlinux0.kallsyms.o
> > >           LD      .tmp_vmlinux1
> > >         ./arch/x86/kernel/vmlinux.lds:154: undefined symbol `__stack_chk_guard' referenced in expression
> > >         scripts/Makefile.vmlinux:77: recipe for target 'vmlinux' failed
> > >         make[2]: *** [vmlinux] Error 1
> > >         /home/oleg/tmp/LINUX/Makefile:1225: recipe for target 'vmlinux' failed
> > >         make[1]: *** [vmlinux] Error 2
> > >         Makefile:251: recipe for target '__sub-make' failed
> > >         make: *** [__sub-make] Error 2
> > >
> > > perhaps this is because my toolchain is quite old,
> > >
> > >         $ ld -v
> > >         GNU ld version 2.25-17.fc23
> > >
> > > but according to Documentation/process/changes.rst
> > >
> > >         binutils               2.25             ld -v
> > >
> > > it is still supported.
> > >
> >
> > We're about to bump the minimum toolchain requirements to GCC 8.1 (and
> > whichever version of binutils was current at the time), so you might
> > want to consider upgrading.
> >
> > However, you are right that these are still supported today, and so we
> > need this fix this, especially because this has been backported to
> > older stable kernels too.
> >
> > For the patch,
> >
> > Acked-by: Ard Biesheuvel <ardb@kernel.org>
>
> Using PROVIDES() is now unnecessary.
>

At this point, the use of -mstack-protector-guard-symbol is still
limited to 32-bit x86. However, if we drop PROVIDE() here, the 64-bit
kernel will also gain a symbol `__ref_stack_chk_guard` in its symbol
table (and /proc/kallsyms, most likely).

Not sure whether that matters or not, but I'd rather keep the
PROVIDE() as it doesn't do any harm.

^ permalink raw reply	[flat|nested] 67+ messages in thread

* Re: [PATCH] x86/stackprotector: fix build failure with CONFIG_STACKPROTECTOR=n
  2024-12-06 15:17             ` Ard Biesheuvel
@ 2025-03-10 21:44               ` Borislav Petkov
  2025-03-10 22:19                 ` Ard Biesheuvel
  0 siblings, 1 reply; 67+ messages in thread
From: Borislav Petkov @ 2025-03-10 21:44 UTC (permalink / raw)
  To: Ard Biesheuvel
  Cc: Brian Gerst, Oleg Nesterov, linux-kernel, x86, Ingo Molnar,
	H . Peter Anvin, Thomas Gleixner, Uros Bizjak, stable,
	Fangrui Song, Nathan Chancellor, Andy Lutomirski

Just to report this, bisection tomorrow unless someone figures it out in the
meantime...

This is 64-bit, allmodconfig, clang:

clang --version
Ubuntu clang version 15.0.7
Target: x86_64-pc-linux-gnu
Thread model: posix
InstalledDir: /usr/bin

This guy:

Ubuntu clang version 18.1.3 (1ubuntu1)
Target: x86_64-pc-linux-gnu
Thread model: posix
InstalledDir: /usr/bin

on the other box builds fine.

tip/master:

commit bc6bc2e1d7fa7e950c5ffb1ddf19bbaf15ad8863 (HEAD, refs/remotes/tip/master)
Merge: f00b8d0b903a 72dafb567760
Author: Ingo Molnar <mingo@kernel.org>
Date:   Mon Mar 10 21:57:15 2025 +0100

    Merge branch into tip/master: 'x86/sev'
    
     # New commits in x86/sev:
        72dafb567760 ("x86/sev: Add missing RIP_REL_REF() invocations during sme_enable()")
    
    Signed-off-by: Ingo Molnar <mingo@kernel.org>


vmlinux.o: warning: objtool: set_ftrace_ops_ro+0x30: relocation to !ENDBR: .text+0x180475
Absolute reference to symbol '__ref_stack_chk_guard' not permitted in .head.text
make[3]: *** [arch/x86/Makefile.postlink:28: vmlinux] Error 1
make[2]: *** [scripts/Makefile.vmlinux:77: vmlinux] Error 2
make[2]: *** Deleting file 'vmlinux'
make[1]: *** [/home/amd/kernel/linux/Makefile:1234: vmlinux] Error 2
make[1]: *** Waiting for unfinished jobs....
make: *** [Makefile:251: __sub-make] Error 2

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette

^ permalink raw reply	[flat|nested] 67+ messages in thread

* Re: [PATCH] x86/stackprotector: fix build failure with CONFIG_STACKPROTECTOR=n
  2025-03-10 21:44               ` Borislav Petkov
@ 2025-03-10 22:19                 ` Ard Biesheuvel
  2025-03-11 10:23                   ` Borislav Petkov
  0 siblings, 1 reply; 67+ messages in thread
From: Ard Biesheuvel @ 2025-03-10 22:19 UTC (permalink / raw)
  To: Borislav Petkov
  Cc: Brian Gerst, Oleg Nesterov, linux-kernel, x86, Ingo Molnar,
	H . Peter Anvin, Thomas Gleixner, Uros Bizjak, stable,
	Fangrui Song, Nathan Chancellor, Andy Lutomirski

On Mon, 10 Mar 2025 at 22:44, Borislav Petkov <bp@alien8.de> wrote:
>
> Just to report this, bisection tomorrow unless someone figures it out in the
> meantime...
>
> This is 64-bit, allmodconfig, clang:
>
> clang --version
> Ubuntu clang version 15.0.7
> Target: x86_64-pc-linux-gnu
> Thread model: posix
> InstalledDir: /usr/bin
>
> This guy:
>
> Ubuntu clang version 18.1.3 (1ubuntu1)
> Target: x86_64-pc-linux-gnu
> Thread model: posix
> InstalledDir: /usr/bin
>
> on the other box builds fine.
>
> tip/master:
>
> commit bc6bc2e1d7fa7e950c5ffb1ddf19bbaf15ad8863 (HEAD, refs/remotes/tip/master)
> Merge: f00b8d0b903a 72dafb567760
> Author: Ingo Molnar <mingo@kernel.org>
> Date:   Mon Mar 10 21:57:15 2025 +0100
>
>     Merge branch into tip/master: 'x86/sev'
>
>      # New commits in x86/sev:
>         72dafb567760 ("x86/sev: Add missing RIP_REL_REF() invocations during sme_enable()")
>
>     Signed-off-by: Ingo Molnar <mingo@kernel.org>
>
>
> vmlinux.o: warning: objtool: set_ftrace_ops_ro+0x30: relocation to !ENDBR: .text+0x180475
> Absolute reference to symbol '__ref_stack_chk_guard' not permitted in .head.text
> make[3]: *** [arch/x86/Makefile.postlink:28: vmlinux] Error 1
> make[2]: *** [scripts/Makefile.vmlinux:77: vmlinux] Error 2
> make[2]: *** Deleting file 'vmlinux'
> make[1]: *** [/home/amd/kernel/linux/Makefile:1234: vmlinux] Error 2
> make[1]: *** Waiting for unfinished jobs....
> make: *** [Makefile:251: __sub-make] Error 2
>

I tried building allmodconfig from the same commit using

$ clang-15 -v
Debian clang version 15.0.7
Target: x86_64-pc-linux-gnu
Thread model: posix
InstalledDir: /usr/bin

but it does not reproduce for me.

$ make LLVM=-15 bzImage -j100 -s
drivers/spi/spi-amd.o: warning: objtool: amd_set_spi_freq() falls
through to next function amd_spi_busy_wait()
vmlinux.o: warning: objtool: screen_info_fixup_lfb+0x562: stack state
mismatch: reg1[12]=-2-48 reg2[12]=-1+0
vmlinux.o: warning: objtool: set_ftrace_ops_ro+0x30: relocation to
!ENDBR: .text+0x17f535

and no error.

Could you capture the output of

objdump -dr .tmp_vmlinux2 --section .head.text

and share it somewhere please?

^ permalink raw reply	[flat|nested] 67+ messages in thread

* Re: [PATCH] x86/stackprotector: fix build failure with CONFIG_STACKPROTECTOR=n
  2025-03-10 22:19                 ` Ard Biesheuvel
@ 2025-03-11 10:23                   ` Borislav Petkov
  2025-03-11 10:37                     ` Ard Biesheuvel
  0 siblings, 1 reply; 67+ messages in thread
From: Borislav Petkov @ 2025-03-11 10:23 UTC (permalink / raw)
  To: Ard Biesheuvel
  Cc: Brian Gerst, Oleg Nesterov, linux-kernel, x86, Ingo Molnar,
	H . Peter Anvin, Thomas Gleixner, Uros Bizjak, stable,
	Fangrui Song, Nathan Chancellor, Andy Lutomirski

[-- Attachment #1: Type: text/plain, Size: 426 bytes --]

On Mon, Mar 10, 2025 at 11:19:03PM +0100, Ard Biesheuvel wrote:
> and no error.

Oh fun.

> Could you capture the output of
> 
> objdump -dr .tmp_vmlinux2 --section .head.text
> 
> and share it somewhere please?

See attached.

Now lemme try to bisect it, see what this machine says since it is magically
toolchain or whatnot-specific. :-\

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette

[-- Attachment #2: tmp_vmlinux2.disas.gz --]
[-- Type: application/gzip, Size: 28281 bytes --]

^ permalink raw reply	[flat|nested] 67+ messages in thread

* Re: [PATCH] x86/stackprotector: fix build failure with CONFIG_STACKPROTECTOR=n
  2025-03-11 10:23                   ` Borislav Petkov
@ 2025-03-11 10:37                     ` Ard Biesheuvel
  2025-03-11 11:21                       ` Borislav Petkov
  0 siblings, 1 reply; 67+ messages in thread
From: Ard Biesheuvel @ 2025-03-11 10:37 UTC (permalink / raw)
  To: Borislav Petkov
  Cc: Brian Gerst, Oleg Nesterov, linux-kernel, x86, Ingo Molnar,
	H . Peter Anvin, Thomas Gleixner, Uros Bizjak, stable,
	Fangrui Song, Nathan Chancellor, Andy Lutomirski

On Tue, 11 Mar 2025 at 11:24, Borislav Petkov <bp@alien8.de> wrote:
>
> On Mon, Mar 10, 2025 at 11:19:03PM +0100, Ard Biesheuvel wrote:
> > and no error.
>
> Oh fun.
>
> > Could you capture the output of
> >
> > objdump -dr .tmp_vmlinux2 --section .head.text
> >
> > and share it somewhere please?
>
> See attached.
>
> Now lemme try to bisect it, see what this machine says since it is magically
> toolchain or whatnot-specific. :-\
>

There are many occurrences of

ffffffff8373cb87: 49 c7 c6 20 c0 55 86 mov    $0xffffffff8655c020,%r14
ffffffff8373cb8a:         R_X86_64_32S __ref_stack_chk_guard

whereas the ordinary Clang uses R_X86_64_REX_GOTPCRELX here, which are
relaxed by the linker.

I suspect that Ubuntu's Clang 15 has some additional patches that
trigger this behavior.

We could add __no_stack_protector to __head to work around this.

^ permalink raw reply	[flat|nested] 67+ messages in thread

* Re: [PATCH] x86/stackprotector: fix build failure with CONFIG_STACKPROTECTOR=n
  2025-03-11 10:37                     ` Ard Biesheuvel
@ 2025-03-11 11:21                       ` Borislav Petkov
  2025-03-11 13:13                         ` Borislav Petkov
  0 siblings, 1 reply; 67+ messages in thread
From: Borislav Petkov @ 2025-03-11 11:21 UTC (permalink / raw)
  To: Ard Biesheuvel
  Cc: Brian Gerst, Oleg Nesterov, linux-kernel, x86, Ingo Molnar,
	H . Peter Anvin, Thomas Gleixner, Uros Bizjak, stable,
	Fangrui Song, Nathan Chancellor, Andy Lutomirski

On Tue, Mar 11, 2025 at 11:37:59AM +0100, Ard Biesheuvel wrote:
> There are many occurrences of
> 
> ffffffff8373cb87: 49 c7 c6 20 c0 55 86 mov    $0xffffffff8655c020,%r14
> ffffffff8373cb8a:         R_X86_64_32S __ref_stack_chk_guard
> 
> whereas the ordinary Clang uses R_X86_64_REX_GOTPCRELX here, which are
> relaxed by the linker.
> 
> I suspect that Ubuntu's Clang 15 has some additional patches that
> trigger this behavior.

... and then we don't know what else out there does other "additional" patches

;-\
 
> We could add __no_stack_protector to __head to work around this.

Yap, that fixes the build:

diff --git a/arch/x86/include/asm/init.h b/arch/x86/include/asm/init.h
index 0e82ebc5d1e1..6cf4ea847dc3 100644
--- a/arch/x86/include/asm/init.h
+++ b/arch/x86/include/asm/init.h
@@ -2,7 +2,7 @@
 #ifndef _ASM_X86_INIT_H
 #define _ASM_X86_INIT_H
 
-#define __head __section(".head.text") __no_sanitize_undefined
+#define __head __section(".head.text") __no_sanitize_undefined __no_stack_protector
 
 struct x86_mapping_info {
        void *(*alloc_pgt_page)(void *); /* allocate buf for page table */

Thx.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette

^ permalink raw reply related	[flat|nested] 67+ messages in thread

* Re: [PATCH] x86/stackprotector: fix build failure with CONFIG_STACKPROTECTOR=n
  2025-03-11 11:21                       ` Borislav Petkov
@ 2025-03-11 13:13                         ` Borislav Petkov
  2025-03-11 14:37                           ` Oleg Nesterov
  2025-03-12  9:28                           ` Borislav Petkov
  0 siblings, 2 replies; 67+ messages in thread
From: Borislav Petkov @ 2025-03-11 13:13 UTC (permalink / raw)
  To: Ard Biesheuvel
  Cc: Brian Gerst, Oleg Nesterov, linux-kernel, x86, Ingo Molnar,
	H . Peter Anvin, Thomas Gleixner, Uros Bizjak, stable,
	Fangrui Song, Nathan Chancellor, Andy Lutomirski

On Tue, Mar 11, 2025 at 12:21:12PM +0100, Borislav Petkov wrote:
> Yap, that fixes the build:

Lemme run randbuilds with that one, see what else breaks with it.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette

^ permalink raw reply	[flat|nested] 67+ messages in thread

* Re: [PATCH] x86/stackprotector: fix build failure with CONFIG_STACKPROTECTOR=n
  2025-03-11 13:13                         ` Borislav Petkov
@ 2025-03-11 14:37                           ` Oleg Nesterov
  2025-03-11 17:46                             ` Borislav Petkov
  2025-03-12  9:28                           ` Borislav Petkov
  1 sibling, 1 reply; 67+ messages in thread
From: Oleg Nesterov @ 2025-03-11 14:37 UTC (permalink / raw)
  To: Borislav Petkov
  Cc: Ard Biesheuvel, Brian Gerst, linux-kernel, x86, Ingo Molnar,
	H . Peter Anvin, Thomas Gleixner, Uros Bizjak, stable,
	Fangrui Song, Nathan Chancellor, Andy Lutomirski

On 03/11, Borislav Petkov wrote:
>
> On Tue, Mar 11, 2025 at 12:21:12PM +0100, Borislav Petkov wrote:
> > Yap, that fixes the build:
>
> Lemme run randbuilds with that one, see what else breaks with it.

sorry for the off-topic noise, but what about the

	[PATCH] x86/stackprotector: fix build failure with CONFIG_STACKPROTECTOR=n
	https://lore.kernel.org/all/20241206123207.GA2091@redhat.com/

fix for the older binutils? It was acked by Ard.

Should I resend it?

Oleg.


^ permalink raw reply	[flat|nested] 67+ messages in thread

* Re: [PATCH] x86/stackprotector: fix build failure with CONFIG_STACKPROTECTOR=n
  2025-03-11 14:37                           ` Oleg Nesterov
@ 2025-03-11 17:46                             ` Borislav Petkov
  2025-03-11 18:10                               ` Oleg Nesterov
  0 siblings, 1 reply; 67+ messages in thread
From: Borislav Petkov @ 2025-03-11 17:46 UTC (permalink / raw)
  To: Oleg Nesterov
  Cc: Ard Biesheuvel, Brian Gerst, linux-kernel, x86, Ingo Molnar,
	H . Peter Anvin, Thomas Gleixner, Uros Bizjak, stable,
	Fangrui Song, Nathan Chancellor, Andy Lutomirski

On Tue, Mar 11, 2025 at 03:37:25PM +0100, Oleg Nesterov wrote:
> sorry for the off-topic noise, but what about the
> 
> 	[PATCH] x86/stackprotector: fix build failure with CONFIG_STACKPROTECTOR=n
> 	https://lore.kernel.org/all/20241206123207.GA2091@redhat.com/
> 
> fix for the older binutils? It was acked by Ard.
> 
> Should I resend it?

Can you pls explain how you trigger this?

I just did a 

# CONFIG_STACKPROTECTOR is not set

build here and it was fine.

So there's something else I'm missing.

Thx.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette

^ permalink raw reply	[flat|nested] 67+ messages in thread

* Re: [PATCH] x86/stackprotector: fix build failure with CONFIG_STACKPROTECTOR=n
  2025-03-11 17:46                             ` Borislav Petkov
@ 2025-03-11 18:10                               ` Oleg Nesterov
  2025-03-11 19:01                                 ` Borislav Petkov
  0 siblings, 1 reply; 67+ messages in thread
From: Oleg Nesterov @ 2025-03-11 18:10 UTC (permalink / raw)
  To: Borislav Petkov
  Cc: Ard Biesheuvel, Brian Gerst, linux-kernel, x86, Ingo Molnar,
	H . Peter Anvin, Thomas Gleixner, Uros Bizjak, stable,
	Fangrui Song, Nathan Chancellor, Andy Lutomirski

On 03/11, Borislav Petkov wrote:
>
> On Tue, Mar 11, 2025 at 03:37:25PM +0100, Oleg Nesterov wrote:
> > sorry for the off-topic noise, but what about the
> >
> > 	[PATCH] x86/stackprotector: fix build failure with CONFIG_STACKPROTECTOR=n
> > 	https://lore.kernel.org/all/20241206123207.GA2091@redhat.com/
> >
> > fix for the older binutils? It was acked by Ard.
> >
> > Should I resend it?
>
> Can you pls explain how you trigger this?
>
> I just did a
>
> # CONFIG_STACKPROTECTOR is not set
>
> build here and it was fine.
>
> So there's something else I'm missing.

See the "older binutils?" above ;)

my toolchain is quite old,

	$ ld -v
	GNU ld version 2.25-17.fc23

but according to Documentation/process/changes.rst

	binutils               2.25             ld -v

it should be still supported.

Oleg.


^ permalink raw reply	[flat|nested] 67+ messages in thread

* Re: [PATCH] x86/stackprotector: fix build failure with CONFIG_STACKPROTECTOR=n
  2025-03-11 18:10                               ` Oleg Nesterov
@ 2025-03-11 19:01                                 ` Borislav Petkov
  2025-03-11 19:24                                   ` Oleg Nesterov
  0 siblings, 1 reply; 67+ messages in thread
From: Borislav Petkov @ 2025-03-11 19:01 UTC (permalink / raw)
  To: Oleg Nesterov
  Cc: Ard Biesheuvel, Brian Gerst, linux-kernel, x86, Ingo Molnar,
	H . Peter Anvin, Thomas Gleixner, Uros Bizjak, stable,
	Fangrui Song, Nathan Chancellor, Andy Lutomirski

On Tue, Mar 11, 2025 at 07:10:57PM +0100, Oleg Nesterov wrote:
> See the "older binutils?" above ;)
> 
> my toolchain is quite old,
> 
> 	$ ld -v
> 	GNU ld version 2.25-17.fc23
> 
> but according to Documentation/process/changes.rst
> 
> 	binutils               2.25             ld -v
> 
> it should be still supported.

So your issue happens because of older binutils? Any other ingredient?

I'd like for the commit message to contain *exactly* what we're fixing here so
that anyone who reads this, can know whether this fix is needed on her/his
kernel or not...

Thx.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette

^ permalink raw reply	[flat|nested] 67+ messages in thread

* Re: [PATCH] x86/stackprotector: fix build failure with CONFIG_STACKPROTECTOR=n
  2025-03-11 19:01                                 ` Borislav Petkov
@ 2025-03-11 19:24                                   ` Oleg Nesterov
  2025-03-11 21:27                                     ` Brian Gerst
  0 siblings, 1 reply; 67+ messages in thread
From: Oleg Nesterov @ 2025-03-11 19:24 UTC (permalink / raw)
  To: Borislav Petkov
  Cc: Ard Biesheuvel, Brian Gerst, linux-kernel, x86, Ingo Molnar,
	H . Peter Anvin, Thomas Gleixner, Uros Bizjak, stable,
	Fangrui Song, Nathan Chancellor, Andy Lutomirski

On 03/11, Borislav Petkov wrote:
>
> On Tue, Mar 11, 2025 at 07:10:57PM +0100, Oleg Nesterov wrote:
> > See the "older binutils?" above ;)
> >
> > my toolchain is quite old,
> >
> > 	$ ld -v
> > 	GNU ld version 2.25-17.fc23
> >
> > but according to Documentation/process/changes.rst
> >
> > 	binutils               2.25             ld -v
> >
> > it should be still supported.
>
> So your issue happens because of older binutils? Any other ingredient?

Yes, I think so.

> I'd like for the commit message to contain *exactly* what we're fixing here so
> that anyone who reads this, can know whether this fix is needed on her/his
> kernel or not...

OK. I'll update the subject/changelog to explain that this is only
needed for the older binutils and send V2.

Oleg.


^ permalink raw reply	[flat|nested] 67+ messages in thread

* Re: [PATCH] x86/stackprotector: fix build failure with CONFIG_STACKPROTECTOR=n
  2025-03-11 19:24                                   ` Oleg Nesterov
@ 2025-03-11 21:27                                     ` Brian Gerst
  2025-03-11 21:42                                       ` Oleg Nesterov
  0 siblings, 1 reply; 67+ messages in thread
From: Brian Gerst @ 2025-03-11 21:27 UTC (permalink / raw)
  To: Oleg Nesterov
  Cc: Borislav Petkov, Ard Biesheuvel, linux-kernel, x86, Ingo Molnar,
	H . Peter Anvin, Thomas Gleixner, Uros Bizjak, stable,
	Fangrui Song, Nathan Chancellor, Andy Lutomirski

On Tue, Mar 11, 2025 at 3:24 PM Oleg Nesterov <oleg@redhat.com> wrote:
>
> On 03/11, Borislav Petkov wrote:
> >
> > On Tue, Mar 11, 2025 at 07:10:57PM +0100, Oleg Nesterov wrote:
> > > See the "older binutils?" above ;)
> > >
> > > my toolchain is quite old,
> > >
> > >     $ ld -v
> > >     GNU ld version 2.25-17.fc23
> > >
> > > but according to Documentation/process/changes.rst
> > >
> > >     binutils               2.25             ld -v
> > >
> > > it should be still supported.
> >
> > So your issue happens because of older binutils? Any other ingredient?
>
> Yes, I think so.
>
> > I'd like for the commit message to contain *exactly* what we're fixing here so
> > that anyone who reads this, can know whether this fix is needed on her/his
> > kernel or not...
>
> OK. I'll update the subject/changelog to explain that this is only
> needed for the older binutils and send V2.

With it conditional on CONFIG_STACKPROTECTOR, you can also drop PROVIDES().


Brian Gerst

^ permalink raw reply	[flat|nested] 67+ messages in thread

* Re: [PATCH] x86/stackprotector: fix build failure with CONFIG_STACKPROTECTOR=n
  2025-03-11 21:27                                     ` Brian Gerst
@ 2025-03-11 21:42                                       ` Oleg Nesterov
  2025-03-11 21:47                                         ` Brian Gerst
  0 siblings, 1 reply; 67+ messages in thread
From: Oleg Nesterov @ 2025-03-11 21:42 UTC (permalink / raw)
  To: Brian Gerst
  Cc: Borislav Petkov, Ard Biesheuvel, linux-kernel, x86, Ingo Molnar,
	H . Peter Anvin, Thomas Gleixner, Uros Bizjak, stable,
	Fangrui Song, Nathan Chancellor, Andy Lutomirski

On 03/11, Brian Gerst wrote:
>
> On Tue, Mar 11, 2025 at 3:24 PM Oleg Nesterov <oleg@redhat.com> wrote:
> >
> > OK. I'll update the subject/changelog to explain that this is only
> > needed for the older binutils and send V2.
>
> With it conditional on CONFIG_STACKPROTECTOR, you can also drop PROVIDES().

Sorry Brian, I don't understand this magic even remotely...

Do you mean

	-/* needed for Clang - see arch/x86/entry/entry.S */
	-PROVIDE(__ref_stack_chk_guard = __stack_chk_guard);
	+#ifdef CONFIG_STACKPROTECTOR
	+__ref_stack_chk_guard = __stack_chk_guard;
	+#endif

?

Oleg.


^ permalink raw reply	[flat|nested] 67+ messages in thread

* Re: [PATCH] x86/stackprotector: fix build failure with CONFIG_STACKPROTECTOR=n
  2025-03-11 21:42                                       ` Oleg Nesterov
@ 2025-03-11 21:47                                         ` Brian Gerst
  0 siblings, 0 replies; 67+ messages in thread
From: Brian Gerst @ 2025-03-11 21:47 UTC (permalink / raw)
  To: Oleg Nesterov
  Cc: Borislav Petkov, Ard Biesheuvel, linux-kernel, x86, Ingo Molnar,
	H . Peter Anvin, Thomas Gleixner, Uros Bizjak, stable,
	Fangrui Song, Nathan Chancellor, Andy Lutomirski

On Tue, Mar 11, 2025 at 5:42 PM Oleg Nesterov <oleg@redhat.com> wrote:
>
> On 03/11, Brian Gerst wrote:
> >
> > On Tue, Mar 11, 2025 at 3:24 PM Oleg Nesterov <oleg@redhat.com> wrote:
> > >
> > > OK. I'll update the subject/changelog to explain that this is only
> > > needed for the older binutils and send V2.
> >
> > With it conditional on CONFIG_STACKPROTECTOR, you can also drop PROVIDES().
>
> Sorry Brian, I don't understand this magic even remotely...
>
> Do you mean
>
>         -/* needed for Clang - see arch/x86/entry/entry.S */
>         -PROVIDE(__ref_stack_chk_guard = __stack_chk_guard);
>         +#ifdef CONFIG_STACKPROTECTOR
>         +__ref_stack_chk_guard = __stack_chk_guard;
>         +#endif
>
> ?
>
> Oleg.

Yes.  Also keep the comment about Clang.


Brian Gerst

^ permalink raw reply	[flat|nested] 67+ messages in thread

* Re: [PATCH] x86/stackprotector: fix build failure with CONFIG_STACKPROTECTOR=n
  2025-03-11 13:13                         ` Borislav Petkov
  2025-03-11 14:37                           ` Oleg Nesterov
@ 2025-03-12  9:28                           ` Borislav Petkov
  1 sibling, 0 replies; 67+ messages in thread
From: Borislav Petkov @ 2025-03-12  9:28 UTC (permalink / raw)
  To: Ard Biesheuvel
  Cc: Brian Gerst, Oleg Nesterov, linux-kernel, x86, Ingo Molnar,
	H . Peter Anvin, Thomas Gleixner, Uros Bizjak, stable,
	Fangrui Song, Nathan Chancellor, Andy Lutomirski

On Tue, Mar 11, 2025 at 02:13:56PM +0100, Borislav Petkov wrote:
> On Tue, Mar 11, 2025 at 12:21:12PM +0100, Borislav Petkov wrote:
> > Yap, that fixes the build:
> 
> Lemme run randbuilds with that one, see what else breaks with it.

Yeah, looks good.

Pls send a proper patch.

Thx.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette

^ permalink raw reply	[flat|nested] 67+ messages in thread

* [PATCH v5 02/16] x86: Raise minimum GCC version to 8.1
  2024-11-05 15:57 [PATCH v5 00/16] x86-64: Stack protector and percpu improvements Brian Gerst
  2024-11-05 15:57 ` [PATCH v5 01/16] x86/stackprotector: Work around strict Clang TLS symbol requirements Brian Gerst
@ 2024-11-05 15:57 ` Brian Gerst
  2024-12-05 11:44   ` Ard Biesheuvel
  2025-01-14 16:25   ` Borislav Petkov
  2024-11-05 15:57 ` [PATCH v5 03/16] x86/stackprotector: Remove stack protector test scripts Brian Gerst
                   ` (15 subsequent siblings)
  17 siblings, 2 replies; 67+ messages in thread
From: Brian Gerst @ 2024-11-05 15:57 UTC (permalink / raw)
  To: linux-kernel, x86
  Cc: Ingo Molnar, H . Peter Anvin, Thomas Gleixner, Borislav Petkov,
	Ard Biesheuvel, Uros Bizjak, Brian Gerst

Stack protector support on 64-bit currently requires that the percpu
section is linked at absolute address 0 because older compilers fixed
the location of the canary value relative to the GS segment base.
GCC 8.1 introduced options to change where the canary value is located,
allowing it to be configured as a standard percpu variable.  This has
already been done for 32-bit.  Doing the same for 64-bit will enable
removing the code needed to suport zero-based percpu.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
---
 scripts/min-tool-version.sh | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/scripts/min-tool-version.sh b/scripts/min-tool-version.sh
index 91c91201212c..06c4e410ecab 100755
--- a/scripts/min-tool-version.sh
+++ b/scripts/min-tool-version.sh
@@ -19,6 +19,8 @@ binutils)
 gcc)
 	if [ "$ARCH" = parisc64 ]; then
 		echo 12.0.0
+	elif [ "$SRCARCH" = x86 ]; then
+		echo 8.1.0
 	else
 		echo 5.1.0
 	fi
-- 
2.47.0


^ permalink raw reply related	[flat|nested] 67+ messages in thread

* Re: [PATCH v5 02/16] x86: Raise minimum GCC version to 8.1
  2024-11-05 15:57 ` [PATCH v5 02/16] x86: Raise minimum GCC version to 8.1 Brian Gerst
@ 2024-12-05 11:44   ` Ard Biesheuvel
  2024-12-05 16:05     ` Brian Gerst
  2025-01-14 16:25   ` Borislav Petkov
  1 sibling, 1 reply; 67+ messages in thread
From: Ard Biesheuvel @ 2024-12-05 11:44 UTC (permalink / raw)
  To: Brian Gerst
  Cc: linux-kernel, x86, Ingo Molnar, H . Peter Anvin, Thomas Gleixner,
	Borislav Petkov, Uros Bizjak

On Tue, 5 Nov 2024 at 16:58, Brian Gerst <brgerst@gmail.com> wrote:
>
> Stack protector support on 64-bit currently requires that the percpu
> section is linked at absolute address 0 because older compilers fixed
> the location of the canary value relative to the GS segment base.
> GCC 8.1 introduced options to change where the canary value is located,
> allowing it to be configured as a standard percpu variable.  This has
> already been done for 32-bit.  Doing the same for 64-bit will enable
> removing the code needed to suport zero-based percpu.
>
> Signed-off-by: Brian Gerst <brgerst@gmail.com>
> ---
>  scripts/min-tool-version.sh | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/scripts/min-tool-version.sh b/scripts/min-tool-version.sh
> index 91c91201212c..06c4e410ecab 100755
> --- a/scripts/min-tool-version.sh
> +++ b/scripts/min-tool-version.sh
> @@ -19,6 +19,8 @@ binutils)
>  gcc)
>         if [ "$ARCH" = parisc64 ]; then
>                 echo 12.0.0
> +       elif [ "$SRCARCH" = x86 ]; then
> +               echo 8.1.0
>         else
>                 echo 5.1.0
>         fi

There appears to be consensus that we can bump this to GCC 8.1.0 for
all architectures:

https://lore.kernel.org/all/20240925150059.3955569-32-ardb+git@google.com/

^ permalink raw reply	[flat|nested] 67+ messages in thread

* Re: [PATCH v5 02/16] x86: Raise minimum GCC version to 8.1
  2024-12-05 11:44   ` Ard Biesheuvel
@ 2024-12-05 16:05     ` Brian Gerst
  0 siblings, 0 replies; 67+ messages in thread
From: Brian Gerst @ 2024-12-05 16:05 UTC (permalink / raw)
  To: Ard Biesheuvel
  Cc: linux-kernel, x86, Ingo Molnar, H . Peter Anvin, Thomas Gleixner,
	Borislav Petkov, Uros Bizjak

On Thu, Dec 5, 2024 at 6:44 AM Ard Biesheuvel <ardb@kernel.org> wrote:
>
> On Tue, 5 Nov 2024 at 16:58, Brian Gerst <brgerst@gmail.com> wrote:
> >
> > Stack protector support on 64-bit currently requires that the percpu
> > section is linked at absolute address 0 because older compilers fixed
> > the location of the canary value relative to the GS segment base.
> > GCC 8.1 introduced options to change where the canary value is located,
> > allowing it to be configured as a standard percpu variable.  This has
> > already been done for 32-bit.  Doing the same for 64-bit will enable
> > removing the code needed to suport zero-based percpu.
> >
> > Signed-off-by: Brian Gerst <brgerst@gmail.com>
> > ---
> >  scripts/min-tool-version.sh | 2 ++
> >  1 file changed, 2 insertions(+)
> >
> > diff --git a/scripts/min-tool-version.sh b/scripts/min-tool-version.sh
> > index 91c91201212c..06c4e410ecab 100755
> > --- a/scripts/min-tool-version.sh
> > +++ b/scripts/min-tool-version.sh
> > @@ -19,6 +19,8 @@ binutils)
> >  gcc)
> >         if [ "$ARCH" = parisc64 ]; then
> >                 echo 12.0.0
> > +       elif [ "$SRCARCH" = x86 ]; then
> > +               echo 8.1.0
> >         else
> >                 echo 5.1.0
> >         fi
>
> There appears to be consensus that we can bump this to GCC 8.1.0 for
> all architectures:
>
> https://lore.kernel.org/all/20240925150059.3955569-32-ardb+git@google.com/

That may be, but since the scope of this series is for x86, I'd rather
not have to depend on signoffs from all other arch maintainers.


Brian Gerst

^ permalink raw reply	[flat|nested] 67+ messages in thread

* Re: [PATCH v5 02/16] x86: Raise minimum GCC version to 8.1
  2024-11-05 15:57 ` [PATCH v5 02/16] x86: Raise minimum GCC version to 8.1 Brian Gerst
  2024-12-05 11:44   ` Ard Biesheuvel
@ 2025-01-14 16:25   ` Borislav Petkov
  1 sibling, 0 replies; 67+ messages in thread
From: Borislav Petkov @ 2025-01-14 16:25 UTC (permalink / raw)
  To: Brian Gerst
  Cc: linux-kernel, x86, Ingo Molnar, H . Peter Anvin, Thomas Gleixner,
	Ard Biesheuvel, Uros Bizjak

On Tue, Nov 05, 2024 at 10:57:47AM -0500, Brian Gerst wrote:
> Stack protector support on 64-bit currently requires that the percpu
> section is linked at absolute address 0 because older compilers fixed
> the location of the canary value relative to the GS segment base.
> GCC 8.1 introduced options to change where the canary value is located,
> allowing it to be configured as a standard percpu variable.  This has
> already been done for 32-bit.  Doing the same for 64-bit will enable
> removing the code needed to suport zero-based percpu.

Unknown word [suport] in commit message.
Suggestions: ['support'...

Spellchecker please.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette

^ permalink raw reply	[flat|nested] 67+ messages in thread

* [PATCH v5 03/16] x86/stackprotector: Remove stack protector test scripts
  2024-11-05 15:57 [PATCH v5 00/16] x86-64: Stack protector and percpu improvements Brian Gerst
  2024-11-05 15:57 ` [PATCH v5 01/16] x86/stackprotector: Work around strict Clang TLS symbol requirements Brian Gerst
  2024-11-05 15:57 ` [PATCH v5 02/16] x86: Raise minimum GCC version to 8.1 Brian Gerst
@ 2024-11-05 15:57 ` Brian Gerst
  2024-11-07 13:19   ` Uros Bizjak
  2024-11-05 15:57 ` [PATCH v5 04/16] x86/boot: Disable stack protector for early boot code Brian Gerst
                   ` (14 subsequent siblings)
  17 siblings, 1 reply; 67+ messages in thread
From: Brian Gerst @ 2024-11-05 15:57 UTC (permalink / raw)
  To: linux-kernel, x86
  Cc: Ingo Molnar, H . Peter Anvin, Thomas Gleixner, Borislav Petkov,
	Ard Biesheuvel, Uros Bizjak, Brian Gerst

With GCC 8.1 now the minimum supported compiler for x86, these scripts
are no longer needed.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
---
 arch/x86/Kconfig                          | 11 +----------
 scripts/gcc-x86_32-has-stack-protector.sh |  8 --------
 scripts/gcc-x86_64-has-stack-protector.sh |  4 ----
 3 files changed, 1 insertion(+), 22 deletions(-)
 delete mode 100755 scripts/gcc-x86_32-has-stack-protector.sh
 delete mode 100755 scripts/gcc-x86_64-has-stack-protector.sh

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index aa7fac6817c5..45021d57fd9f 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -278,7 +278,7 @@ config X86
 	select HAVE_FUNCTION_ARG_ACCESS_API
 	select HAVE_SETUP_PER_CPU_AREA
 	select HAVE_SOFTIRQ_ON_OWN_STACK
-	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
+	select HAVE_STACKPROTECTOR
 	select HAVE_STACK_VALIDATION		if HAVE_OBJTOOL
 	select HAVE_STATIC_CALL
 	select HAVE_STATIC_CALL_INLINE		if HAVE_OBJTOOL
@@ -418,15 +418,6 @@ config PGTABLE_LEVELS
 	default 3 if X86_PAE
 	default 2
 
-config CC_HAS_SANE_STACKPROTECTOR
-	bool
-	default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC) $(CLANG_FLAGS)) if 64BIT
-	default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC) $(CLANG_FLAGS))
-	help
-	  We have to make sure stack protector is unconditionally disabled if
-	  the compiler produces broken code or if it does not let us control
-	  the segment on 32-bit kernels.
-
 menu "Processor type and features"
 
 config SMP
diff --git a/scripts/gcc-x86_32-has-stack-protector.sh b/scripts/gcc-x86_32-has-stack-protector.sh
deleted file mode 100755
index 9459ca4f0f11..000000000000
--- a/scripts/gcc-x86_32-has-stack-protector.sh
+++ /dev/null
@@ -1,8 +0,0 @@
-#!/bin/sh
-# SPDX-License-Identifier: GPL-2.0
-
-# This requires GCC 8.1 or better.  Specifically, we require
-# -mstack-protector-guard-reg, added by
-# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81708
-
-echo "int foo(void) { char X[200]; return 3; }" | $* -S -x c -m32 -O0 -fstack-protector -mstack-protector-guard-reg=fs -mstack-protector-guard-symbol=__stack_chk_guard - -o - 2> /dev/null | grep -q "%fs"
diff --git a/scripts/gcc-x86_64-has-stack-protector.sh b/scripts/gcc-x86_64-has-stack-protector.sh
deleted file mode 100755
index f680bb01aeeb..000000000000
--- a/scripts/gcc-x86_64-has-stack-protector.sh
+++ /dev/null
@@ -1,4 +0,0 @@
-#!/bin/sh
-# SPDX-License-Identifier: GPL-2.0
-
-echo "int foo(void) { char X[200]; return 3; }" | $* -S -x c -m64 -O0 -mcmodel=kernel -fno-PIE -fstack-protector - -o - 2> /dev/null | grep -q "%gs"
-- 
2.47.0


^ permalink raw reply related	[flat|nested] 67+ messages in thread

* Re: [PATCH v5 03/16] x86/stackprotector: Remove stack protector test scripts
  2024-11-05 15:57 ` [PATCH v5 03/16] x86/stackprotector: Remove stack protector test scripts Brian Gerst
@ 2024-11-07 13:19   ` Uros Bizjak
  0 siblings, 0 replies; 67+ messages in thread
From: Uros Bizjak @ 2024-11-07 13:19 UTC (permalink / raw)
  To: Brian Gerst
  Cc: linux-kernel, x86, Ingo Molnar, H . Peter Anvin, Thomas Gleixner,
	Borislav Petkov, Ard Biesheuvel

On Tue, Nov 5, 2024 at 4:58 PM Brian Gerst <brgerst@gmail.com> wrote:
>
> With GCC 8.1 now the minimum supported compiler for x86, these scripts
> are no longer needed.
>
> Signed-off-by: Brian Gerst <brgerst@gmail.com>

Reviewed-by: Uros Bizjak <ubizjak@gmail.com>

> ---
>  arch/x86/Kconfig                          | 11 +----------
>  scripts/gcc-x86_32-has-stack-protector.sh |  8 --------
>  scripts/gcc-x86_64-has-stack-protector.sh |  4 ----
>  3 files changed, 1 insertion(+), 22 deletions(-)
>  delete mode 100755 scripts/gcc-x86_32-has-stack-protector.sh
>  delete mode 100755 scripts/gcc-x86_64-has-stack-protector.sh
>
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index aa7fac6817c5..45021d57fd9f 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -278,7 +278,7 @@ config X86
>         select HAVE_FUNCTION_ARG_ACCESS_API
>         select HAVE_SETUP_PER_CPU_AREA
>         select HAVE_SOFTIRQ_ON_OWN_STACK
> -       select HAVE_STACKPROTECTOR              if CC_HAS_SANE_STACKPROTECTOR
> +       select HAVE_STACKPROTECTOR
>         select HAVE_STACK_VALIDATION            if HAVE_OBJTOOL
>         select HAVE_STATIC_CALL
>         select HAVE_STATIC_CALL_INLINE          if HAVE_OBJTOOL
> @@ -418,15 +418,6 @@ config PGTABLE_LEVELS
>         default 3 if X86_PAE
>         default 2
>
> -config CC_HAS_SANE_STACKPROTECTOR
> -       bool
> -       default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC) $(CLANG_FLAGS)) if 64BIT
> -       default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC) $(CLANG_FLAGS))
> -       help
> -         We have to make sure stack protector is unconditionally disabled if
> -         the compiler produces broken code or if it does not let us control
> -         the segment on 32-bit kernels.
> -
>  menu "Processor type and features"
>
>  config SMP
> diff --git a/scripts/gcc-x86_32-has-stack-protector.sh b/scripts/gcc-x86_32-has-stack-protector.sh
> deleted file mode 100755
> index 9459ca4f0f11..000000000000
> --- a/scripts/gcc-x86_32-has-stack-protector.sh
> +++ /dev/null
> @@ -1,8 +0,0 @@
> -#!/bin/sh
> -# SPDX-License-Identifier: GPL-2.0
> -
> -# This requires GCC 8.1 or better.  Specifically, we require
> -# -mstack-protector-guard-reg, added by
> -# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81708
> -
> -echo "int foo(void) { char X[200]; return 3; }" | $* -S -x c -m32 -O0 -fstack-protector -mstack-protector-guard-reg=fs -mstack-protector-guard-symbol=__stack_chk_guard - -o - 2> /dev/null | grep -q "%fs"
> diff --git a/scripts/gcc-x86_64-has-stack-protector.sh b/scripts/gcc-x86_64-has-stack-protector.sh
> deleted file mode 100755
> index f680bb01aeeb..000000000000
> --- a/scripts/gcc-x86_64-has-stack-protector.sh
> +++ /dev/null
> @@ -1,4 +0,0 @@
> -#!/bin/sh
> -# SPDX-License-Identifier: GPL-2.0
> -
> -echo "int foo(void) { char X[200]; return 3; }" | $* -S -x c -m64 -O0 -mcmodel=kernel -fno-PIE -fstack-protector - -o - 2> /dev/null | grep -q "%gs"
> --
> 2.47.0
>

^ permalink raw reply	[flat|nested] 67+ messages in thread

* [PATCH v5 04/16] x86/boot: Disable stack protector for early boot code
  2024-11-05 15:57 [PATCH v5 00/16] x86-64: Stack protector and percpu improvements Brian Gerst
                   ` (2 preceding siblings ...)
  2024-11-05 15:57 ` [PATCH v5 03/16] x86/stackprotector: Remove stack protector test scripts Brian Gerst
@ 2024-11-05 15:57 ` Brian Gerst
  2024-11-05 15:57 ` [PATCH v5 05/16] x86/pvh: Use fixed_percpu_data for early boot GSBASE Brian Gerst
                   ` (13 subsequent siblings)
  17 siblings, 0 replies; 67+ messages in thread
From: Brian Gerst @ 2024-11-05 15:57 UTC (permalink / raw)
  To: linux-kernel, x86
  Cc: Ingo Molnar, H . Peter Anvin, Thomas Gleixner, Borislav Petkov,
	Ard Biesheuvel, Uros Bizjak, Brian Gerst

On 64-bit, this will prevent crashes when the canary access is changed
from %gs:40 to %gs:__stack_chk_guard(%rip).  RIP-relative addresses from
the identity-mapped early boot code will target the wrong address with
zero-based percpu.  KASLR could then shift that address to an unmapped
page causing a crash on boot.

This early boot code runs well before userspace is active and does not
need stack protector enabled.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
---
 arch/x86/kernel/Makefile | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index f7918980667a..f42c0903ef86 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -44,6 +44,8 @@ KCOV_INSTRUMENT_unwind_orc.o				:= n
 KCOV_INSTRUMENT_unwind_frame.o				:= n
 KCOV_INSTRUMENT_unwind_guess.o				:= n
 
+CFLAGS_head32.o := -fno-stack-protector
+CFLAGS_head64.o := -fno-stack-protector
 CFLAGS_irq.o := -I $(src)/../include/asm/trace
 
 obj-y			+= head_$(BITS).o
-- 
2.47.0


^ permalink raw reply related	[flat|nested] 67+ messages in thread

* [PATCH v5 05/16] x86/pvh: Use fixed_percpu_data for early boot GSBASE
  2024-11-05 15:57 [PATCH v5 00/16] x86-64: Stack protector and percpu improvements Brian Gerst
                   ` (3 preceding siblings ...)
  2024-11-05 15:57 ` [PATCH v5 04/16] x86/boot: Disable stack protector for early boot code Brian Gerst
@ 2024-11-05 15:57 ` Brian Gerst
  2024-11-07 14:30   ` Uros Bizjak
  2024-11-05 15:57 ` [PATCH v5 06/16] x86/relocs: Handle R_X86_64_REX_GOTPCRELX relocations Brian Gerst
                   ` (12 subsequent siblings)
  17 siblings, 1 reply; 67+ messages in thread
From: Brian Gerst @ 2024-11-05 15:57 UTC (permalink / raw)
  To: linux-kernel, x86
  Cc: Ingo Molnar, H . Peter Anvin, Thomas Gleixner, Borislav Petkov,
	Ard Biesheuvel, Uros Bizjak, Brian Gerst

Instead of having a private area for the stack canary, use
fixed_percpu_data for GSBASE like the native kernel.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
---
 arch/x86/platform/pvh/head.S | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/arch/x86/platform/pvh/head.S b/arch/x86/platform/pvh/head.S
index 64fca49cd88f..b0a9a58952aa 100644
--- a/arch/x86/platform/pvh/head.S
+++ b/arch/x86/platform/pvh/head.S
@@ -159,10 +159,15 @@ SYM_CODE_START_LOCAL(pvh_start_xen)
 1:
 	UNWIND_HINT_END_OF_STACK
 
-	/* Set base address in stack canary descriptor. */
-	mov $MSR_GS_BASE,%ecx
-	leal canary(%rip), %eax
-	xor %edx, %edx
+	/*
+	 * Set up GSBASE.
+	 * Note that, on SMP, the boot cpu uses init data section until
+	 * the per cpu areas are set up.
+	 */
+	movl $MSR_GS_BASE,%ecx
+	leaq INIT_PER_CPU_VAR(fixed_percpu_data)(%rip), %rdx
+	movq %edx, %eax
+	shrq $32, %rdx
 	wrmsr
 
 	/*
@@ -232,8 +237,6 @@ SYM_DATA_START_LOCAL(gdt_start)
 SYM_DATA_END_LABEL(gdt_start, SYM_L_LOCAL, gdt_end)
 
 	.balign 16
-SYM_DATA_LOCAL(canary, .fill 48, 1, 0)
-
 SYM_DATA_START_LOCAL(early_stack)
 	.fill BOOT_STACK_SIZE, 1, 0
 SYM_DATA_END_LABEL(early_stack, SYM_L_LOCAL, early_stack_end)
-- 
2.47.0


^ permalink raw reply related	[flat|nested] 67+ messages in thread

* Re: [PATCH v5 05/16] x86/pvh: Use fixed_percpu_data for early boot GSBASE
  2024-11-05 15:57 ` [PATCH v5 05/16] x86/pvh: Use fixed_percpu_data for early boot GSBASE Brian Gerst
@ 2024-11-07 14:30   ` Uros Bizjak
  0 siblings, 0 replies; 67+ messages in thread
From: Uros Bizjak @ 2024-11-07 14:30 UTC (permalink / raw)
  To: Brian Gerst
  Cc: linux-kernel, x86, Ingo Molnar, H . Peter Anvin, Thomas Gleixner,
	Borislav Petkov, Ard Biesheuvel, Juergen Gross, Boris Ostrovsky,
	xen-devel

On Tue, Nov 5, 2024 at 4:58 PM Brian Gerst <brgerst@gmail.com> wrote:
>
> Instead of having a private area for the stack canary, use
> fixed_percpu_data for GSBASE like the native kernel.
>
> Signed-off-by: Brian Gerst <brgerst@gmail.com>
> ---

This patch looks like it could be submitted independently of the main
series and should include XEN maintainers (CC'd).

Uros.

>  arch/x86/platform/pvh/head.S | 15 +++++++++------
>  1 file changed, 9 insertions(+), 6 deletions(-)
>
> diff --git a/arch/x86/platform/pvh/head.S b/arch/x86/platform/pvh/head.S
> index 64fca49cd88f..b0a9a58952aa 100644
> --- a/arch/x86/platform/pvh/head.S
> +++ b/arch/x86/platform/pvh/head.S
> @@ -159,10 +159,15 @@ SYM_CODE_START_LOCAL(pvh_start_xen)
>  1:
>         UNWIND_HINT_END_OF_STACK
>
> -       /* Set base address in stack canary descriptor. */
> -       mov $MSR_GS_BASE,%ecx
> -       leal canary(%rip), %eax
> -       xor %edx, %edx
> +       /*
> +        * Set up GSBASE.
> +        * Note that, on SMP, the boot cpu uses init data section until
> +        * the per cpu areas are set up.
> +        */
> +       movl $MSR_GS_BASE,%ecx
> +       leaq INIT_PER_CPU_VAR(fixed_percpu_data)(%rip), %rdx
> +       movq %edx, %eax
> +       shrq $32, %rdx
>         wrmsr
>
>         /*
> @@ -232,8 +237,6 @@ SYM_DATA_START_LOCAL(gdt_start)
>  SYM_DATA_END_LABEL(gdt_start, SYM_L_LOCAL, gdt_end)
>
>         .balign 16
> -SYM_DATA_LOCAL(canary, .fill 48, 1, 0)
> -
>  SYM_DATA_START_LOCAL(early_stack)
>         .fill BOOT_STACK_SIZE, 1, 0
>  SYM_DATA_END_LABEL(early_stack, SYM_L_LOCAL, early_stack_end)
> --
> 2.47.0
>

^ permalink raw reply	[flat|nested] 67+ messages in thread

* [PATCH v5 06/16] x86/relocs: Handle R_X86_64_REX_GOTPCRELX relocations
  2024-11-05 15:57 [PATCH v5 00/16] x86-64: Stack protector and percpu improvements Brian Gerst
                   ` (4 preceding siblings ...)
  2024-11-05 15:57 ` [PATCH v5 05/16] x86/pvh: Use fixed_percpu_data for early boot GSBASE Brian Gerst
@ 2024-11-05 15:57 ` Brian Gerst
  2024-11-07 11:20   ` Uros Bizjak
  2024-11-05 15:57 ` [PATCH v5 07/16] x86/module: Deal with GOT based stack cookie load on Clang < 17 Brian Gerst
                   ` (11 subsequent siblings)
  17 siblings, 1 reply; 67+ messages in thread
From: Brian Gerst @ 2024-11-05 15:57 UTC (permalink / raw)
  To: linux-kernel, x86
  Cc: Ingo Molnar, H . Peter Anvin, Thomas Gleixner, Borislav Petkov,
	Ard Biesheuvel, Uros Bizjak, Brian Gerst

Clang may produce R_X86_64_REX_GOTPCRELX relocations when redefining the
stack protector location.  Treat them as another type of PC-relative
relocation.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
---
 arch/x86/tools/relocs.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c
index 6afe2e5e9102..7d7fc7f0a250 100644
--- a/arch/x86/tools/relocs.c
+++ b/arch/x86/tools/relocs.c
@@ -32,6 +32,11 @@ static struct relocs		relocs32;
 static struct relocs		relocs32neg;
 static struct relocs		relocs64;
 # define FMT PRIu64
+
+#ifndef R_X86_64_REX_GOTPCRELX
+#define R_X86_64_REX_GOTPCRELX 42
+#endif
+
 #else
 # define FMT PRIu32
 #endif
@@ -226,6 +231,7 @@ static const char *rel_type(unsigned type)
 		REL_TYPE(R_X86_64_PC16),
 		REL_TYPE(R_X86_64_8),
 		REL_TYPE(R_X86_64_PC8),
+		REL_TYPE(R_X86_64_REX_GOTPCRELX),
 #else
 		REL_TYPE(R_386_NONE),
 		REL_TYPE(R_386_32),
@@ -860,6 +866,7 @@ static int do_reloc64(struct section *sec, Elf_Rel *rel, ElfW(Sym) *sym,
 
 	case R_X86_64_PC32:
 	case R_X86_64_PLT32:
+	case R_X86_64_REX_GOTPCRELX:
 		/*
 		 * PC relative relocations don't need to be adjusted unless
 		 * referencing a percpu symbol.
-- 
2.47.0


^ permalink raw reply related	[flat|nested] 67+ messages in thread

* Re: [PATCH v5 06/16] x86/relocs: Handle R_X86_64_REX_GOTPCRELX relocations
  2024-11-05 15:57 ` [PATCH v5 06/16] x86/relocs: Handle R_X86_64_REX_GOTPCRELX relocations Brian Gerst
@ 2024-11-07 11:20   ` Uros Bizjak
  2024-11-07 11:27     ` Brian Gerst
  0 siblings, 1 reply; 67+ messages in thread
From: Uros Bizjak @ 2024-11-07 11:20 UTC (permalink / raw)
  To: Brian Gerst
  Cc: linux-kernel, x86, Ingo Molnar, H . Peter Anvin, Thomas Gleixner,
	Borislav Petkov, Ard Biesheuvel

On Tue, Nov 5, 2024 at 4:58 PM Brian Gerst <brgerst@gmail.com> wrote:
>
> Clang may produce R_X86_64_REX_GOTPCRELX relocations when redefining the
> stack protector location.  Treat them as another type of PC-relative
> relocation.
>
> Signed-off-by: Brian Gerst <brgerst@gmail.com>
> ---
>  arch/x86/tools/relocs.c | 7 +++++++
>  1 file changed, 7 insertions(+)
>
> diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c
> index 6afe2e5e9102..7d7fc7f0a250 100644
> --- a/arch/x86/tools/relocs.c
> +++ b/arch/x86/tools/relocs.c
> @@ -32,6 +32,11 @@ static struct relocs         relocs32;
>  static struct relocs           relocs32neg;
>  static struct relocs           relocs64;
>  # define FMT PRIu64
> +
> +#ifndef R_X86_64_REX_GOTPCRELX
> +#define R_X86_64_REX_GOTPCRELX 42
> +#endif

The next patch (7/16) introduces the above definition to
arch/x86/include/asm/elf.h. If you swap patches 6 and 7 in the series,
you won't have to introduce the above conditional definition.

Uros.

> +
>  #else
>  # define FMT PRIu32
>  #endif
> @@ -226,6 +231,7 @@ static const char *rel_type(unsigned type)
>                 REL_TYPE(R_X86_64_PC16),
>                 REL_TYPE(R_X86_64_8),
>                 REL_TYPE(R_X86_64_PC8),
> +               REL_TYPE(R_X86_64_REX_GOTPCRELX),
>  #else
>                 REL_TYPE(R_386_NONE),
>                 REL_TYPE(R_386_32),
> @@ -860,6 +866,7 @@ static int do_reloc64(struct section *sec, Elf_Rel *rel, ElfW(Sym) *sym,
>
>         case R_X86_64_PC32:
>         case R_X86_64_PLT32:
> +       case R_X86_64_REX_GOTPCRELX:
>                 /*
>                  * PC relative relocations don't need to be adjusted unless
>                  * referencing a percpu symbol.
> --
> 2.47.0
>

^ permalink raw reply	[flat|nested] 67+ messages in thread

* Re: [PATCH v5 06/16] x86/relocs: Handle R_X86_64_REX_GOTPCRELX relocations
  2024-11-07 11:20   ` Uros Bizjak
@ 2024-11-07 11:27     ` Brian Gerst
  2024-11-07 11:31       ` Uros Bizjak
  0 siblings, 1 reply; 67+ messages in thread
From: Brian Gerst @ 2024-11-07 11:27 UTC (permalink / raw)
  To: Uros Bizjak
  Cc: linux-kernel, x86, Ingo Molnar, H . Peter Anvin, Thomas Gleixner,
	Borislav Petkov, Ard Biesheuvel

On Thu, Nov 7, 2024 at 6:20 AM Uros Bizjak <ubizjak@gmail.com> wrote:
>
> On Tue, Nov 5, 2024 at 4:58 PM Brian Gerst <brgerst@gmail.com> wrote:
> >
> > Clang may produce R_X86_64_REX_GOTPCRELX relocations when redefining the
> > stack protector location.  Treat them as another type of PC-relative
> > relocation.
> >
> > Signed-off-by: Brian Gerst <brgerst@gmail.com>
> > ---
> >  arch/x86/tools/relocs.c | 7 +++++++
> >  1 file changed, 7 insertions(+)
> >
> > diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c
> > index 6afe2e5e9102..7d7fc7f0a250 100644
> > --- a/arch/x86/tools/relocs.c
> > +++ b/arch/x86/tools/relocs.c
> > @@ -32,6 +32,11 @@ static struct relocs         relocs32;
> >  static struct relocs           relocs32neg;
> >  static struct relocs           relocs64;
> >  # define FMT PRIu64
> > +
> > +#ifndef R_X86_64_REX_GOTPCRELX
> > +#define R_X86_64_REX_GOTPCRELX 42
> > +#endif
>
> The next patch (7/16) introduces the above definition to
> arch/x86/include/asm/elf.h. If you swap patches 6 and 7 in the series,
> you won't have to introduce the above conditional definition.
>
> Uros.

This is a userspace tool, so it's using the build host libc headers.

--
Brian Gerst

^ permalink raw reply	[flat|nested] 67+ messages in thread

* Re: [PATCH v5 06/16] x86/relocs: Handle R_X86_64_REX_GOTPCRELX relocations
  2024-11-07 11:27     ` Brian Gerst
@ 2024-11-07 11:31       ` Uros Bizjak
  0 siblings, 0 replies; 67+ messages in thread
From: Uros Bizjak @ 2024-11-07 11:31 UTC (permalink / raw)
  To: Brian Gerst
  Cc: linux-kernel, x86, Ingo Molnar, H . Peter Anvin, Thomas Gleixner,
	Borislav Petkov, Ard Biesheuvel

On Thu, Nov 7, 2024 at 12:27 PM Brian Gerst <brgerst@gmail.com> wrote:
>
> On Thu, Nov 7, 2024 at 6:20 AM Uros Bizjak <ubizjak@gmail.com> wrote:
> >
> > On Tue, Nov 5, 2024 at 4:58 PM Brian Gerst <brgerst@gmail.com> wrote:
> > >
> > > Clang may produce R_X86_64_REX_GOTPCRELX relocations when redefining the
> > > stack protector location.  Treat them as another type of PC-relative
> > > relocation.
> > >
> > > Signed-off-by: Brian Gerst <brgerst@gmail.com>
> > > ---
> > >  arch/x86/tools/relocs.c | 7 +++++++
> > >  1 file changed, 7 insertions(+)
> > >
> > > diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c
> > > index 6afe2e5e9102..7d7fc7f0a250 100644
> > > --- a/arch/x86/tools/relocs.c
> > > +++ b/arch/x86/tools/relocs.c
> > > @@ -32,6 +32,11 @@ static struct relocs         relocs32;
> > >  static struct relocs           relocs32neg;
> > >  static struct relocs           relocs64;
> > >  # define FMT PRIu64
> > > +
> > > +#ifndef R_X86_64_REX_GOTPCRELX
> > > +#define R_X86_64_REX_GOTPCRELX 42
> > > +#endif
> >
> > The next patch (7/16) introduces the above definition to
> > arch/x86/include/asm/elf.h. If you swap patches 6 and 7 in the series,
> > you won't have to introduce the above conditional definition.
>
> This is a userspace tool, so it's using the build host libc headers.

Ah, indeed.

Thanks,
Uros.

^ permalink raw reply	[flat|nested] 67+ messages in thread

* [PATCH v5 07/16] x86/module: Deal with GOT based stack cookie load on Clang < 17
  2024-11-05 15:57 [PATCH v5 00/16] x86-64: Stack protector and percpu improvements Brian Gerst
                   ` (5 preceding siblings ...)
  2024-11-05 15:57 ` [PATCH v5 06/16] x86/relocs: Handle R_X86_64_REX_GOTPCRELX relocations Brian Gerst
@ 2024-11-05 15:57 ` Brian Gerst
  2024-11-09  9:36   ` David Laight
  2024-11-05 15:57 ` [PATCH v5 08/16] x86/stackprotector/64: Convert to normal percpu variable Brian Gerst
                   ` (10 subsequent siblings)
  17 siblings, 1 reply; 67+ messages in thread
From: Brian Gerst @ 2024-11-05 15:57 UTC (permalink / raw)
  To: linux-kernel, x86
  Cc: Ingo Molnar, H . Peter Anvin, Thomas Gleixner, Borislav Petkov,
	Ard Biesheuvel, Uros Bizjak, Brian Gerst

From: Ard Biesheuvel <ardb@kernel.org>

Clang versions before 17 will not honour -fdirect-access-external-data
for the load of the stack cookie emitted into each function's prologue
and epilogue.

This is not an issue for the core kernel, as the linker will relax these
loads into LEA instructions that take the address of __stack_chk_guard
directly. For modules, however, we need to work around this, by dealing
with R_X86_64_REX_GOTPCRELX relocations that refer to __stack_chk_guard.

In this case, given that this is a GOT load, the reference should not
refer to __stack_chk_guard directly, but to a memory location that holds
its address. So take the address of __stack_chk_guard into a static
variable, and fix up the relocations to refer to that.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Brian Gerst <brgerst@gmail.com>
---
 arch/x86/include/asm/elf.h |  3 ++-
 arch/x86/kernel/module.c   | 15 +++++++++++++++
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h
index 1fb83d47711f..0d6ca771549d 100644
--- a/arch/x86/include/asm/elf.h
+++ b/arch/x86/include/asm/elf.h
@@ -55,7 +55,8 @@ typedef struct user_i387_struct elf_fpregset_t;
 #define R_X86_64_JUMP_SLOT	7	/* Create PLT entry */
 #define R_X86_64_RELATIVE	8	/* Adjust by program base */
 #define R_X86_64_GOTPCREL	9	/* 32 bit signed pc relative
-					   offset to GOT */
+#define R_X86_64_GOTPCRELX	41	   offset to GOT */
+#define R_X86_64_REX_GOTPCRELX	42
 #define R_X86_64_32		10	/* Direct 32 bit zero extended */
 #define R_X86_64_32S		11	/* Direct 32 bit sign extended */
 #define R_X86_64_16		12	/* Direct 16 bit zero extended */
diff --git a/arch/x86/kernel/module.c b/arch/x86/kernel/module.c
index 837450b6e882..9929be7a76e7 100644
--- a/arch/x86/kernel/module.c
+++ b/arch/x86/kernel/module.c
@@ -19,6 +19,7 @@
 #include <linux/jump_label.h>
 #include <linux/random.h>
 #include <linux/memory.h>
+#include <linux/stackprotector.h>
 
 #include <asm/text-patching.h>
 #include <asm/page.h>
@@ -130,6 +131,20 @@ static int __write_relocate_add(Elf64_Shdr *sechdrs,
 				goto overflow;
 			size = 4;
 			break;
+#if defined(CONFIG_STACKPROTECTOR) && \
+    defined(CONFIG_CC_IS_CLANG) && CONFIG_CLANG_VERSION < 170000
+		case R_X86_64_REX_GOTPCRELX: {
+			static unsigned long __percpu *const addr = &__stack_chk_guard;
+
+			if (sym->st_value != (u64)addr) {
+				pr_err("%s: Unsupported GOTPCREL relocation\n", me->name);
+				return -ENOEXEC;
+			}
+
+			val = (u64)&addr + rel[i].r_addend;
+			fallthrough;
+		}
+#endif
 		case R_X86_64_PC32:
 		case R_X86_64_PLT32:
 			val -= (u64)loc;
-- 
2.47.0


^ permalink raw reply related	[flat|nested] 67+ messages in thread

* RE: [PATCH v5 07/16] x86/module: Deal with GOT based stack cookie load on Clang < 17
  2024-11-05 15:57 ` [PATCH v5 07/16] x86/module: Deal with GOT based stack cookie load on Clang < 17 Brian Gerst
@ 2024-11-09  9:36   ` David Laight
  0 siblings, 0 replies; 67+ messages in thread
From: David Laight @ 2024-11-09  9:36 UTC (permalink / raw)
  To: 'Brian Gerst', linux-kernel@vger.kernel.org,
	x86@kernel.org
  Cc: Ingo Molnar, H . Peter Anvin, Thomas Gleixner, Borislav Petkov,
	Ard Biesheuvel, Uros Bizjak

From: Brian Gerst
> Sent: 05 November 2024 15:58
> 
> From: Ard Biesheuvel <ardb@kernel.org>
> 
> Clang versions before 17 will not honour -fdirect-access-external-data
> for the load of the stack cookie emitted into each function's prologue
> and epilogue.
> 
> This is not an issue for the core kernel, as the linker will relax these
> loads into LEA instructions that take the address of __stack_chk_guard
> directly. For modules, however, we need to work around this, by dealing
> with R_X86_64_REX_GOTPCRELX relocations that refer to __stack_chk_guard.
> 
> In this case, given that this is a GOT load, the reference should not
> refer to __stack_chk_guard directly, but to a memory location that holds
> its address. So take the address of __stack_chk_guard into a static
> variable, and fix up the relocations to refer to that.
> 
...
> +#if defined(CONFIG_STACKPROTECTOR) && \
> +    defined(CONFIG_CC_IS_CLANG) && CONFIG_CLANG_VERSION < 170000
> +		case R_X86_64_REX_GOTPCRELX: {
> +			static unsigned long __percpu *const addr = &__stack_chk_guard;
> +
> +			if (sym->st_value != (u64)addr) {
> +				pr_err("%s: Unsupported GOTPCREL relocation\n", me->name);
> +				return -ENOEXEC;
> +			}
> +
> +			val = (u64)&addr + rel[i].r_addend;
> +			fallthrough;
> +		}
> +#endif

Doesn't this depend on the compiler used to compile the module not that
used to compile this code?
(In principle external modules should be able to use a different compiler.)

So the CLANG tests should be replaced by a comment.

	David

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)


^ permalink raw reply	[flat|nested] 67+ messages in thread

* [PATCH v5 08/16] x86/stackprotector/64: Convert to normal percpu variable
  2024-11-05 15:57 [PATCH v5 00/16] x86-64: Stack protector and percpu improvements Brian Gerst
                   ` (6 preceding siblings ...)
  2024-11-05 15:57 ` [PATCH v5 07/16] x86/module: Deal with GOT based stack cookie load on Clang < 17 Brian Gerst
@ 2024-11-05 15:57 ` Brian Gerst
  2024-11-07 13:29   ` Uros Bizjak
  2025-02-15 14:27   ` Borislav Petkov
  2024-11-05 15:57 ` [PATCH v5 09/16] x86/percpu/64: Use relative percpu offsets Brian Gerst
                   ` (9 subsequent siblings)
  17 siblings, 2 replies; 67+ messages in thread
From: Brian Gerst @ 2024-11-05 15:57 UTC (permalink / raw)
  To: linux-kernel, x86
  Cc: Ingo Molnar, H . Peter Anvin, Thomas Gleixner, Borislav Petkov,
	Ard Biesheuvel, Uros Bizjak, Brian Gerst

Older versions of GCC fixed the location of the stack protector canary
at %gs:40.  This constraint forced the percpu section to be linked at
absolute address 0 so that the canary could be the first data object in
the percpu section.  Supporting the zero-based percpu section requires
additional code to handle relocations for RIP-relative references to
percpu data, extra complexity to kallsyms, and workarounds for linker
bugs due to the use of absolute symbols.

GCC 8.1 supports redefining where the canary is located, allowng it to
become a normal percpu variable instead of at a fixed location.  This
removes the contraint that the percpu section must be zero-based.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
---
 arch/x86/Makefile                     | 20 +++++++++------
 arch/x86/entry/entry.S                |  2 --
 arch/x86/entry/entry_64.S             |  2 +-
 arch/x86/include/asm/processor.h      | 16 ++----------
 arch/x86/include/asm/stackprotector.h | 36 ++++-----------------------
 arch/x86/kernel/asm-offsets_64.c      |  6 -----
 arch/x86/kernel/cpu/common.c          |  5 +---
 arch/x86/kernel/head_64.S             |  3 +--
 arch/x86/xen/xen-head.S               |  3 +--
 9 files changed, 23 insertions(+), 70 deletions(-)

diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index 5b773b34768d..88a1705366f9 100644
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -140,14 +140,7 @@ ifeq ($(CONFIG_X86_32),y)
         # temporary until string.h is fixed
         KBUILD_CFLAGS += -ffreestanding
 
-    ifeq ($(CONFIG_STACKPROTECTOR),y)
-        ifeq ($(CONFIG_SMP),y)
-            KBUILD_CFLAGS += -mstack-protector-guard-reg=fs \
-                             -mstack-protector-guard-symbol=__ref_stack_chk_guard
-        else
-            KBUILD_CFLAGS += -mstack-protector-guard=global
-        endif
-    endif
+        percpu_seg := fs
 else
         BITS := 64
         UTS_MACHINE := x86_64
@@ -197,6 +190,17 @@ else
         KBUILD_CFLAGS += -mcmodel=kernel
         KBUILD_RUSTFLAGS += -Cno-redzone=y
         KBUILD_RUSTFLAGS += -Ccode-model=kernel
+
+        percpu_seg := gs
+endif
+
+ifeq ($(CONFIG_STACKPROTECTOR),y)
+    ifeq ($(CONFIG_SMP),y)
+	KBUILD_CFLAGS += -mstack-protector-guard-reg=$(percpu_seg)
+	KBUILD_CFLAGS += -mstack-protector-guard-symbol=__ref_stack_chk_guard
+    else
+	KBUILD_CFLAGS += -mstack-protector-guard=global
+    endif
 endif
 
 #
diff --git a/arch/x86/entry/entry.S b/arch/x86/entry/entry.S
index b7ea3e8e9ecc..fe5344a249a1 100644
--- a/arch/x86/entry/entry.S
+++ b/arch/x86/entry/entry.S
@@ -52,7 +52,6 @@ EXPORT_SYMBOL_GPL(mds_verw_sel);
 
 THUNK warn_thunk_thunk, __warn_thunk
 
-#ifndef CONFIG_X86_64
 /*
  * Clang's implementation of TLS stack cookies requires the variable in
  * question to be a TLS variable. If the variable happens to be defined as an
@@ -66,4 +65,3 @@ THUNK warn_thunk_thunk, __warn_thunk
 #ifdef CONFIG_STACKPROTECTOR
 EXPORT_SYMBOL(__ref_stack_chk_guard);
 #endif
-#endif
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 1b5be07f8669..f78ef9667c39 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -192,7 +192,7 @@ SYM_FUNC_START(__switch_to_asm)
 
 #ifdef CONFIG_STACKPROTECTOR
 	movq	TASK_stack_canary(%rsi), %rbx
-	movq	%rbx, PER_CPU_VAR(fixed_percpu_data + FIXED_stack_canary)
+	movq	%rbx, PER_CPU_VAR(__stack_chk_guard)
 #endif
 
 	/*
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index c0975815980c..a113c3f4f558 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -419,16 +419,8 @@ struct irq_stack {
 
 #ifdef CONFIG_X86_64
 struct fixed_percpu_data {
-	/*
-	 * GCC hardcodes the stack canary as %gs:40.  Since the
-	 * irq_stack is the object at %gs:0, we reserve the bottom
-	 * 48 bytes of the irq stack for the canary.
-	 *
-	 * Once we are willing to require -mstack-protector-guard-symbol=
-	 * support for x86_64 stackprotector, we can get rid of this.
-	 */
 	char		gs_base[40];
-	unsigned long	stack_canary;
+	unsigned long	reserved;
 };
 
 DECLARE_PER_CPU_FIRST(struct fixed_percpu_data, fixed_percpu_data) __visible;
@@ -443,11 +435,7 @@ extern asmlinkage void entry_SYSCALL32_ignore(void);
 
 /* Save actual FS/GS selectors and bases to current->thread */
 void current_save_fsgs(void);
-#else	/* X86_64 */
-#ifdef CONFIG_STACKPROTECTOR
-DECLARE_PER_CPU(unsigned long, __stack_chk_guard);
-#endif
-#endif	/* !X86_64 */
+#endif	/* X86_64 */
 
 struct perf_event;
 
diff --git a/arch/x86/include/asm/stackprotector.h b/arch/x86/include/asm/stackprotector.h
index 00473a650f51..d43fb589fcf6 100644
--- a/arch/x86/include/asm/stackprotector.h
+++ b/arch/x86/include/asm/stackprotector.h
@@ -2,26 +2,10 @@
 /*
  * GCC stack protector support.
  *
- * Stack protector works by putting predefined pattern at the start of
+ * Stack protector works by putting a predefined pattern at the start of
  * the stack frame and verifying that it hasn't been overwritten when
- * returning from the function.  The pattern is called stack canary
- * and unfortunately gcc historically required it to be at a fixed offset
- * from the percpu segment base.  On x86_64, the offset is 40 bytes.
- *
- * The same segment is shared by percpu area and stack canary.  On
- * x86_64, percpu symbols are zero based and %gs (64-bit) points to the
- * base of percpu area.  The first occupant of the percpu area is always
- * fixed_percpu_data which contains stack_canary at the appropriate
- * offset.  On x86_32, the stack canary is just a regular percpu
- * variable.
- *
- * Putting percpu data in %fs on 32-bit is a minor optimization compared to
- * using %gs.  Since 32-bit userspace normally has %fs == 0, we are likely
- * to load 0 into %fs on exit to usermode, whereas with percpu data in
- * %gs, we are likely to load a non-null %gs on return to user mode.
- *
- * Once we are willing to require GCC 8.1 or better for 64-bit stackprotector
- * support, we can remove some of this complexity.
+ * returning from the function.  The pattern is called the stack canary
+ * and is a unique value for each task.
  */
 
 #ifndef _ASM_STACKPROTECTOR_H
@@ -36,6 +20,8 @@
 
 #include <linux/sched.h>
 
+DECLARE_PER_CPU(unsigned long, __stack_chk_guard);
+
 /*
  * Initialize the stackprotector canary value.
  *
@@ -51,25 +37,13 @@ static __always_inline void boot_init_stack_canary(void)
 {
 	unsigned long canary = get_random_canary();
 
-#ifdef CONFIG_X86_64
-	BUILD_BUG_ON(offsetof(struct fixed_percpu_data, stack_canary) != 40);
-#endif
-
 	current->stack_canary = canary;
-#ifdef CONFIG_X86_64
-	this_cpu_write(fixed_percpu_data.stack_canary, canary);
-#else
 	this_cpu_write(__stack_chk_guard, canary);
-#endif
 }
 
 static inline void cpu_init_stack_canary(int cpu, struct task_struct *idle)
 {
-#ifdef CONFIG_X86_64
-	per_cpu(fixed_percpu_data.stack_canary, cpu) = idle->stack_canary;
-#else
 	per_cpu(__stack_chk_guard, cpu) = idle->stack_canary;
-#endif
 }
 
 #else	/* STACKPROTECTOR */
diff --git a/arch/x86/kernel/asm-offsets_64.c b/arch/x86/kernel/asm-offsets_64.c
index bb65371ea9df..590b6cd0eac0 100644
--- a/arch/x86/kernel/asm-offsets_64.c
+++ b/arch/x86/kernel/asm-offsets_64.c
@@ -54,11 +54,5 @@ int main(void)
 	BLANK();
 #undef ENTRY
 
-	BLANK();
-
-#ifdef CONFIG_STACKPROTECTOR
-	OFFSET(FIXED_stack_canary, fixed_percpu_data, stack_canary);
-	BLANK();
-#endif
 	return 0;
 }
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 9d42bd15e06c..1f33d5feb050 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -2086,8 +2086,7 @@ void syscall_init(void)
 	if (!cpu_feature_enabled(X86_FEATURE_FRED))
 		idt_syscall_init();
 }
-
-#else	/* CONFIG_X86_64 */
+#endif /* CONFIG_X86_64 */
 
 #ifdef CONFIG_STACKPROTECTOR
 DEFINE_PER_CPU(unsigned long, __stack_chk_guard);
@@ -2096,8 +2095,6 @@ EXPORT_PER_CPU_SYMBOL(__stack_chk_guard);
 #endif
 #endif
 
-#endif	/* CONFIG_X86_64 */
-
 /*
  * Clear all 6 debug registers:
  */
diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index 56163e2124cf..c3028b4df85f 100644
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -355,8 +355,7 @@ SYM_INNER_LABEL(common_startup_64, SYM_L_LOCAL)
 
 	/* Set up %gs.
 	 *
-	 * The base of %gs always points to fixed_percpu_data. If the
-	 * stack protector canary is enabled, it is located at %gs:40.
+	 * The base of %gs always points to fixed_percpu_data.
 	 * Note that, on SMP, the boot cpu uses init data section until
 	 * the per cpu areas are set up.
 	 */
diff --git a/arch/x86/xen/xen-head.S b/arch/x86/xen/xen-head.S
index 758bcd47b72d..ae4672ea00bb 100644
--- a/arch/x86/xen/xen-head.S
+++ b/arch/x86/xen/xen-head.S
@@ -53,8 +53,7 @@ SYM_CODE_START(startup_xen)
 
 	/* Set up %gs.
 	 *
-	 * The base of %gs always points to fixed_percpu_data.  If the
-	 * stack protector canary is enabled, it is located at %gs:40.
+	 * The base of %gs always points to fixed_percpu_data.
 	 * Note that, on SMP, the boot cpu uses init data section until
 	 * the per cpu areas are set up.
 	 */
-- 
2.47.0


^ permalink raw reply related	[flat|nested] 67+ messages in thread

* Re: [PATCH v5 08/16] x86/stackprotector/64: Convert to normal percpu variable
  2024-11-05 15:57 ` [PATCH v5 08/16] x86/stackprotector/64: Convert to normal percpu variable Brian Gerst
@ 2024-11-07 13:29   ` Uros Bizjak
  2025-02-15 14:27   ` Borislav Petkov
  1 sibling, 0 replies; 67+ messages in thread
From: Uros Bizjak @ 2024-11-07 13:29 UTC (permalink / raw)
  To: Brian Gerst
  Cc: linux-kernel, x86, Ingo Molnar, H . Peter Anvin, Thomas Gleixner,
	Borislav Petkov, Ard Biesheuvel

On Tue, Nov 5, 2024 at 4:58 PM Brian Gerst <brgerst@gmail.com> wrote:
>
> Older versions of GCC fixed the location of the stack protector canary
> at %gs:40.  This constraint forced the percpu section to be linked at
> absolute address 0 so that the canary could be the first data object in
> the percpu section.  Supporting the zero-based percpu section requires
> additional code to handle relocations for RIP-relative references to
> percpu data, extra complexity to kallsyms, and workarounds for linker
> bugs due to the use of absolute symbols.
>
> GCC 8.1 supports redefining where the canary is located, allowng it to
> become a normal percpu variable instead of at a fixed location.  This
> removes the contraint that the percpu section must be zero-based.
>
> Signed-off-by: Brian Gerst <brgerst@gmail.com>

Reviewed-by: Uros Bizjak <ubizjak@gmail.com>

> ---
>  arch/x86/Makefile                     | 20 +++++++++------
>  arch/x86/entry/entry.S                |  2 --
>  arch/x86/entry/entry_64.S             |  2 +-
>  arch/x86/include/asm/processor.h      | 16 ++----------
>  arch/x86/include/asm/stackprotector.h | 36 ++++-----------------------
>  arch/x86/kernel/asm-offsets_64.c      |  6 -----
>  arch/x86/kernel/cpu/common.c          |  5 +---
>  arch/x86/kernel/head_64.S             |  3 +--
>  arch/x86/xen/xen-head.S               |  3 +--
>  9 files changed, 23 insertions(+), 70 deletions(-)
>
> diff --git a/arch/x86/Makefile b/arch/x86/Makefile
> index 5b773b34768d..88a1705366f9 100644
> --- a/arch/x86/Makefile
> +++ b/arch/x86/Makefile
> @@ -140,14 +140,7 @@ ifeq ($(CONFIG_X86_32),y)
>          # temporary until string.h is fixed
>          KBUILD_CFLAGS += -ffreestanding
>
> -    ifeq ($(CONFIG_STACKPROTECTOR),y)
> -        ifeq ($(CONFIG_SMP),y)
> -            KBUILD_CFLAGS += -mstack-protector-guard-reg=fs \
> -                             -mstack-protector-guard-symbol=__ref_stack_chk_guard
> -        else
> -            KBUILD_CFLAGS += -mstack-protector-guard=global
> -        endif
> -    endif
> +        percpu_seg := fs
>  else
>          BITS := 64
>          UTS_MACHINE := x86_64
> @@ -197,6 +190,17 @@ else
>          KBUILD_CFLAGS += -mcmodel=kernel
>          KBUILD_RUSTFLAGS += -Cno-redzone=y
>          KBUILD_RUSTFLAGS += -Ccode-model=kernel
> +
> +        percpu_seg := gs
> +endif
> +
> +ifeq ($(CONFIG_STACKPROTECTOR),y)
> +    ifeq ($(CONFIG_SMP),y)
> +       KBUILD_CFLAGS += -mstack-protector-guard-reg=$(percpu_seg)
> +       KBUILD_CFLAGS += -mstack-protector-guard-symbol=__ref_stack_chk_guard
> +    else
> +       KBUILD_CFLAGS += -mstack-protector-guard=global
> +    endif
>  endif
>
>  #
> diff --git a/arch/x86/entry/entry.S b/arch/x86/entry/entry.S
> index b7ea3e8e9ecc..fe5344a249a1 100644
> --- a/arch/x86/entry/entry.S
> +++ b/arch/x86/entry/entry.S
> @@ -52,7 +52,6 @@ EXPORT_SYMBOL_GPL(mds_verw_sel);
>
>  THUNK warn_thunk_thunk, __warn_thunk
>
> -#ifndef CONFIG_X86_64
>  /*
>   * Clang's implementation of TLS stack cookies requires the variable in
>   * question to be a TLS variable. If the variable happens to be defined as an
> @@ -66,4 +65,3 @@ THUNK warn_thunk_thunk, __warn_thunk
>  #ifdef CONFIG_STACKPROTECTOR
>  EXPORT_SYMBOL(__ref_stack_chk_guard);
>  #endif
> -#endif
> diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
> index 1b5be07f8669..f78ef9667c39 100644
> --- a/arch/x86/entry/entry_64.S
> +++ b/arch/x86/entry/entry_64.S
> @@ -192,7 +192,7 @@ SYM_FUNC_START(__switch_to_asm)
>
>  #ifdef CONFIG_STACKPROTECTOR
>         movq    TASK_stack_canary(%rsi), %rbx
> -       movq    %rbx, PER_CPU_VAR(fixed_percpu_data + FIXED_stack_canary)
> +       movq    %rbx, PER_CPU_VAR(__stack_chk_guard)
>  #endif
>
>         /*
> diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
> index c0975815980c..a113c3f4f558 100644
> --- a/arch/x86/include/asm/processor.h
> +++ b/arch/x86/include/asm/processor.h
> @@ -419,16 +419,8 @@ struct irq_stack {
>
>  #ifdef CONFIG_X86_64
>  struct fixed_percpu_data {
> -       /*
> -        * GCC hardcodes the stack canary as %gs:40.  Since the
> -        * irq_stack is the object at %gs:0, we reserve the bottom
> -        * 48 bytes of the irq stack for the canary.
> -        *
> -        * Once we are willing to require -mstack-protector-guard-symbol=
> -        * support for x86_64 stackprotector, we can get rid of this.
> -        */
>         char            gs_base[40];
> -       unsigned long   stack_canary;
> +       unsigned long   reserved;
>  };
>
>  DECLARE_PER_CPU_FIRST(struct fixed_percpu_data, fixed_percpu_data) __visible;
> @@ -443,11 +435,7 @@ extern asmlinkage void entry_SYSCALL32_ignore(void);
>
>  /* Save actual FS/GS selectors and bases to current->thread */
>  void current_save_fsgs(void);
> -#else  /* X86_64 */
> -#ifdef CONFIG_STACKPROTECTOR
> -DECLARE_PER_CPU(unsigned long, __stack_chk_guard);
> -#endif
> -#endif /* !X86_64 */
> +#endif /* X86_64 */
>
>  struct perf_event;
>
> diff --git a/arch/x86/include/asm/stackprotector.h b/arch/x86/include/asm/stackprotector.h
> index 00473a650f51..d43fb589fcf6 100644
> --- a/arch/x86/include/asm/stackprotector.h
> +++ b/arch/x86/include/asm/stackprotector.h
> @@ -2,26 +2,10 @@
>  /*
>   * GCC stack protector support.
>   *
> - * Stack protector works by putting predefined pattern at the start of
> + * Stack protector works by putting a predefined pattern at the start of
>   * the stack frame and verifying that it hasn't been overwritten when
> - * returning from the function.  The pattern is called stack canary
> - * and unfortunately gcc historically required it to be at a fixed offset
> - * from the percpu segment base.  On x86_64, the offset is 40 bytes.
> - *
> - * The same segment is shared by percpu area and stack canary.  On
> - * x86_64, percpu symbols are zero based and %gs (64-bit) points to the
> - * base of percpu area.  The first occupant of the percpu area is always
> - * fixed_percpu_data which contains stack_canary at the appropriate
> - * offset.  On x86_32, the stack canary is just a regular percpu
> - * variable.
> - *
> - * Putting percpu data in %fs on 32-bit is a minor optimization compared to
> - * using %gs.  Since 32-bit userspace normally has %fs == 0, we are likely
> - * to load 0 into %fs on exit to usermode, whereas with percpu data in
> - * %gs, we are likely to load a non-null %gs on return to user mode.
> - *
> - * Once we are willing to require GCC 8.1 or better for 64-bit stackprotector
> - * support, we can remove some of this complexity.
> + * returning from the function.  The pattern is called the stack canary
> + * and is a unique value for each task.
>   */
>
>  #ifndef _ASM_STACKPROTECTOR_H
> @@ -36,6 +20,8 @@
>
>  #include <linux/sched.h>
>
> +DECLARE_PER_CPU(unsigned long, __stack_chk_guard);
> +
>  /*
>   * Initialize the stackprotector canary value.
>   *
> @@ -51,25 +37,13 @@ static __always_inline void boot_init_stack_canary(void)
>  {
>         unsigned long canary = get_random_canary();
>
> -#ifdef CONFIG_X86_64
> -       BUILD_BUG_ON(offsetof(struct fixed_percpu_data, stack_canary) != 40);
> -#endif
> -
>         current->stack_canary = canary;
> -#ifdef CONFIG_X86_64
> -       this_cpu_write(fixed_percpu_data.stack_canary, canary);
> -#else
>         this_cpu_write(__stack_chk_guard, canary);
> -#endif
>  }
>
>  static inline void cpu_init_stack_canary(int cpu, struct task_struct *idle)
>  {
> -#ifdef CONFIG_X86_64
> -       per_cpu(fixed_percpu_data.stack_canary, cpu) = idle->stack_canary;
> -#else
>         per_cpu(__stack_chk_guard, cpu) = idle->stack_canary;
> -#endif
>  }
>
>  #else  /* STACKPROTECTOR */
> diff --git a/arch/x86/kernel/asm-offsets_64.c b/arch/x86/kernel/asm-offsets_64.c
> index bb65371ea9df..590b6cd0eac0 100644
> --- a/arch/x86/kernel/asm-offsets_64.c
> +++ b/arch/x86/kernel/asm-offsets_64.c
> @@ -54,11 +54,5 @@ int main(void)
>         BLANK();
>  #undef ENTRY
>
> -       BLANK();
> -
> -#ifdef CONFIG_STACKPROTECTOR
> -       OFFSET(FIXED_stack_canary, fixed_percpu_data, stack_canary);
> -       BLANK();
> -#endif
>         return 0;
>  }
> diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
> index 9d42bd15e06c..1f33d5feb050 100644
> --- a/arch/x86/kernel/cpu/common.c
> +++ b/arch/x86/kernel/cpu/common.c
> @@ -2086,8 +2086,7 @@ void syscall_init(void)
>         if (!cpu_feature_enabled(X86_FEATURE_FRED))
>                 idt_syscall_init();
>  }
> -
> -#else  /* CONFIG_X86_64 */
> +#endif /* CONFIG_X86_64 */
>
>  #ifdef CONFIG_STACKPROTECTOR
>  DEFINE_PER_CPU(unsigned long, __stack_chk_guard);
> @@ -2096,8 +2095,6 @@ EXPORT_PER_CPU_SYMBOL(__stack_chk_guard);
>  #endif
>  #endif
>
> -#endif /* CONFIG_X86_64 */
> -
>  /*
>   * Clear all 6 debug registers:
>   */
> diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
> index 56163e2124cf..c3028b4df85f 100644
> --- a/arch/x86/kernel/head_64.S
> +++ b/arch/x86/kernel/head_64.S
> @@ -355,8 +355,7 @@ SYM_INNER_LABEL(common_startup_64, SYM_L_LOCAL)
>
>         /* Set up %gs.
>          *
> -        * The base of %gs always points to fixed_percpu_data. If the
> -        * stack protector canary is enabled, it is located at %gs:40.
> +        * The base of %gs always points to fixed_percpu_data.
>          * Note that, on SMP, the boot cpu uses init data section until
>          * the per cpu areas are set up.
>          */
> diff --git a/arch/x86/xen/xen-head.S b/arch/x86/xen/xen-head.S
> index 758bcd47b72d..ae4672ea00bb 100644
> --- a/arch/x86/xen/xen-head.S
> +++ b/arch/x86/xen/xen-head.S
> @@ -53,8 +53,7 @@ SYM_CODE_START(startup_xen)
>
>         /* Set up %gs.
>          *
> -        * The base of %gs always points to fixed_percpu_data.  If the
> -        * stack protector canary is enabled, it is located at %gs:40.
> +        * The base of %gs always points to fixed_percpu_data.
>          * Note that, on SMP, the boot cpu uses init data section until
>          * the per cpu areas are set up.
>          */
> --
> 2.47.0
>

^ permalink raw reply	[flat|nested] 67+ messages in thread

* Re: [PATCH v5 08/16] x86/stackprotector/64: Convert to normal percpu variable
  2024-11-05 15:57 ` [PATCH v5 08/16] x86/stackprotector/64: Convert to normal percpu variable Brian Gerst
  2024-11-07 13:29   ` Uros Bizjak
@ 2025-02-15 14:27   ` Borislav Petkov
  2025-02-15 17:38     ` Brian Gerst
  1 sibling, 1 reply; 67+ messages in thread
From: Borislav Petkov @ 2025-02-15 14:27 UTC (permalink / raw)
  To: Brian Gerst
  Cc: linux-kernel, x86, Ingo Molnar, H . Peter Anvin, Thomas Gleixner,
	Ard Biesheuvel, Uros Bizjak

On Tue, Nov 05, 2024 at 10:57:53AM -0500, Brian Gerst wrote:
> Older versions of GCC fixed the location of the stack protector canary
> at %gs:40.  This constraint forced the percpu section to be linked at
> absolute address 0 so that the canary could be the first data object in
> the percpu section.  Supporting the zero-based percpu section requires
> additional code to handle relocations for RIP-relative references to
> percpu data, extra complexity to kallsyms, and workarounds for linker
> bugs due to the use of absolute symbols.
> 
> GCC 8.1 supports redefining where the canary is located, allowng it to
> become a normal percpu variable instead of at a fixed location.  This
> removes the contraint that the percpu section must be zero-based.

Unknown word [contraint] in commit message.
Suggestions: ['constraint',...

Use a spellchecker for your commit messages please.

> diff --git a/arch/x86/Makefile b/arch/x86/Makefile
> index 5b773b34768d..88a1705366f9 100644
> --- a/arch/x86/Makefile
> +++ b/arch/x86/Makefile
> @@ -140,14 +140,7 @@ ifeq ($(CONFIG_X86_32),y)
>          # temporary until string.h is fixed
>          KBUILD_CFLAGS += -ffreestanding
>  
> -    ifeq ($(CONFIG_STACKPROTECTOR),y)
> -        ifeq ($(CONFIG_SMP),y)
> -            KBUILD_CFLAGS += -mstack-protector-guard-reg=fs \
> -                             -mstack-protector-guard-symbol=__ref_stack_chk_guard
> -        else
> -            KBUILD_CFLAGS += -mstack-protector-guard=global
> -        endif
> -    endif
> +        percpu_seg := fs

Any particular reason this var is not in all caps like the rest of the vars in
this file?

	PERCPU_SEG := fs

...

Thx.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette

^ permalink raw reply	[flat|nested] 67+ messages in thread

* Re: [PATCH v5 08/16] x86/stackprotector/64: Convert to normal percpu variable
  2025-02-15 14:27   ` Borislav Petkov
@ 2025-02-15 17:38     ` Brian Gerst
  2025-02-15 21:18       ` Borislav Petkov
  0 siblings, 1 reply; 67+ messages in thread
From: Brian Gerst @ 2025-02-15 17:38 UTC (permalink / raw)
  To: Borislav Petkov
  Cc: linux-kernel, x86, Ingo Molnar, H . Peter Anvin, Thomas Gleixner,
	Ard Biesheuvel, Uros Bizjak

On Sat, Feb 15, 2025 at 9:27 AM Borislav Petkov <bp@alien8.de> wrote:
>
> On Tue, Nov 05, 2024 at 10:57:53AM -0500, Brian Gerst wrote:
> > Older versions of GCC fixed the location of the stack protector canary
> > at %gs:40.  This constraint forced the percpu section to be linked at
> > absolute address 0 so that the canary could be the first data object in
> > the percpu section.  Supporting the zero-based percpu section requires
> > additional code to handle relocations for RIP-relative references to
> > percpu data, extra complexity to kallsyms, and workarounds for linker
> > bugs due to the use of absolute symbols.
> >
> > GCC 8.1 supports redefining where the canary is located, allowng it to
> > become a normal percpu variable instead of at a fixed location.  This
> > removes the contraint that the percpu section must be zero-based.
>
> Unknown word [contraint] in commit message.
> Suggestions: ['constraint',...
>
> Use a spellchecker for your commit messages please.
>
> > diff --git a/arch/x86/Makefile b/arch/x86/Makefile
> > index 5b773b34768d..88a1705366f9 100644
> > --- a/arch/x86/Makefile
> > +++ b/arch/x86/Makefile
> > @@ -140,14 +140,7 @@ ifeq ($(CONFIG_X86_32),y)
> >          # temporary until string.h is fixed
> >          KBUILD_CFLAGS += -ffreestanding
> >
> > -    ifeq ($(CONFIG_STACKPROTECTOR),y)
> > -        ifeq ($(CONFIG_SMP),y)
> > -            KBUILD_CFLAGS += -mstack-protector-guard-reg=fs \
> > -                             -mstack-protector-guard-symbol=__ref_stack_chk_guard
> > -        else
> > -            KBUILD_CFLAGS += -mstack-protector-guard=global
> > -        endif
> > -    endif
> > +        percpu_seg := fs
>
> Any particular reason this var is not in all caps like the rest of the vars in
> this file?
>
>         PERCPU_SEG := fs

The convention appears to me to be that all caps are used for global
variables used by the core build scripts and/or exported to
subdirectory makefiles, whereas lower case is for local variables.

PS.  Please comment on the most recent patch series, v6.



Brian Gerst

^ permalink raw reply	[flat|nested] 67+ messages in thread

* Re: [PATCH v5 08/16] x86/stackprotector/64: Convert to normal percpu variable
  2025-02-15 17:38     ` Brian Gerst
@ 2025-02-15 21:18       ` Borislav Petkov
  2025-02-15 22:10         ` Brian Gerst
  0 siblings, 1 reply; 67+ messages in thread
From: Borislav Petkov @ 2025-02-15 21:18 UTC (permalink / raw)
  To: Brian Gerst
  Cc: linux-kernel, x86, Ingo Molnar, H . Peter Anvin, Thomas Gleixner,
	Ard Biesheuvel, Uros Bizjak

On Sat, Feb 15, 2025 at 12:38:21PM -0500, Brian Gerst wrote:
> The convention appears to me to be that all caps are used for global
> variables used by the core build scripts and/or exported to
> subdirectory makefiles, whereas lower case is for local variables.

First time I hear of such a convention:

$ git grep -w ACCUMULATE_OUTGOING_ARGS
arch/x86/Makefile:213:  ACCUMULATE_OUTGOING_ARGS := 1
arch/x86/Makefile:217:ifeq ($(ACCUMULATE_OUTGOING_ARGS), 1)

That one should be lowercase too I guess.

> PS.  Please comment on the most recent patch series, v6.

Ok.

Thx.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette

^ permalink raw reply	[flat|nested] 67+ messages in thread

* Re: [PATCH v5 08/16] x86/stackprotector/64: Convert to normal percpu variable
  2025-02-15 21:18       ` Borislav Petkov
@ 2025-02-15 22:10         ` Brian Gerst
  2025-02-16  8:33           ` Borislav Petkov
  0 siblings, 1 reply; 67+ messages in thread
From: Brian Gerst @ 2025-02-15 22:10 UTC (permalink / raw)
  To: Borislav Petkov
  Cc: linux-kernel, x86, Ingo Molnar, H . Peter Anvin, Thomas Gleixner,
	Ard Biesheuvel, Uros Bizjak

On Sat, Feb 15, 2025 at 4:19 PM Borislav Petkov <bp@alien8.de> wrote:
>
> On Sat, Feb 15, 2025 at 12:38:21PM -0500, Brian Gerst wrote:
> > The convention appears to me to be that all caps are used for global
> > variables used by the core build scripts and/or exported to
> > subdirectory makefiles, whereas lower case is for local variables.
>
> First time I hear of such a convention:

If you want it changed, please just say so.  I don't care either way.


Brian Gerst

^ permalink raw reply	[flat|nested] 67+ messages in thread

* Re: [PATCH v5 08/16] x86/stackprotector/64: Convert to normal percpu variable
  2025-02-15 22:10         ` Brian Gerst
@ 2025-02-16  8:33           ` Borislav Petkov
  0 siblings, 0 replies; 67+ messages in thread
From: Borislav Petkov @ 2025-02-16  8:33 UTC (permalink / raw)
  To: Brian Gerst
  Cc: linux-kernel, x86, Ingo Molnar, H . Peter Anvin, Thomas Gleixner,
	Ard Biesheuvel, Uros Bizjak

On Sat, Feb 15, 2025 at 05:10:55PM -0500, Brian Gerst wrote:
> If you want it changed, please just say so.  I don't care either way.

No need to do anything now - if it turns out only trivial touchups are needed,
they can be done while applying.

Thx.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette

^ permalink raw reply	[flat|nested] 67+ messages in thread

* [PATCH v5 09/16] x86/percpu/64: Use relative percpu offsets
  2024-11-05 15:57 [PATCH v5 00/16] x86-64: Stack protector and percpu improvements Brian Gerst
                   ` (7 preceding siblings ...)
  2024-11-05 15:57 ` [PATCH v5 08/16] x86/stackprotector/64: Convert to normal percpu variable Brian Gerst
@ 2024-11-05 15:57 ` Brian Gerst
  2024-11-07 11:28   ` Uros Bizjak
  2024-11-05 15:57 ` [PATCH v5 10/16] x86/percpu/64: Remove fixed_percpu_data Brian Gerst
                   ` (8 subsequent siblings)
  17 siblings, 1 reply; 67+ messages in thread
From: Brian Gerst @ 2024-11-05 15:57 UTC (permalink / raw)
  To: linux-kernel, x86
  Cc: Ingo Molnar, H . Peter Anvin, Thomas Gleixner, Borislav Petkov,
	Ard Biesheuvel, Uros Bizjak, Brian Gerst

The percpu section is currently linked at absolute address 0, because
older compilers hardcoded the stack protector canary value at a fixed
offset from the start of the GS segment.  Now that the canary is a
normal percpu variable, the percpu section does not need to be linked
at a specific address.

x86-64 will now calculate the percpu offsets as the delta between the
initial percpu address and the dynamically allocated memory, like other
architectures.  Note that GSBASE is limited to the canonical address
width (48 or 57 bits, sign-extended).  As long as the kernel text,
modules, and the dynamically allocated percpu memmory are all in the
negative address space, the delta will not overflow this limit.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
---
 arch/x86/include/asm/processor.h |  6 +++++-
 arch/x86/kernel/head_64.S        | 19 +++++++++----------
 arch/x86/kernel/setup_percpu.c   | 12 ++----------
 arch/x86/kernel/vmlinux.lds.S    | 29 +----------------------------
 arch/x86/platform/pvh/head.S     |  5 ++---
 arch/x86/tools/relocs.c          | 10 +++-------
 arch/x86/xen/xen-head.S          |  9 ++++-----
 init/Kconfig                     |  2 +-
 8 files changed, 27 insertions(+), 65 deletions(-)

diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index a113c3f4f558..ae50d5d4fa26 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -428,7 +428,11 @@ DECLARE_INIT_PER_CPU(fixed_percpu_data);
 
 static inline unsigned long cpu_kernelmode_gs_base(int cpu)
 {
-	return (unsigned long)per_cpu(fixed_percpu_data.gs_base, cpu);
+#ifdef CONFIG_SMP
+	return per_cpu_offset(cpu);
+#else
+	return 0;
+#endif
 }
 
 extern asmlinkage void entry_SYSCALL32_ignore(void);
diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index c3028b4df85f..ffbcb0aea450 100644
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -61,11 +61,14 @@ SYM_CODE_START_NOALIGN(startup_64)
 	/* Set up the stack for verify_cpu() */
 	leaq	__top_init_kernel_stack(%rip), %rsp
 
-	/* Setup GSBASE to allow stack canary access for C code */
+	/*
+	 * Set up GSBASE.
+	 * Note that, on SMP, the boot cpu uses init data section until
+	 * the per cpu areas are set up.
+	 */
 	movl	$MSR_GS_BASE, %ecx
-	leaq	INIT_PER_CPU_VAR(fixed_percpu_data)(%rip), %rdx
-	movl	%edx, %eax
-	shrq	$32,  %rdx
+	xorl	%eax, %eax
+	xorl	%edx, %edx
 	wrmsr
 
 	call	startup_64_setup_gdt_idt
@@ -353,16 +356,12 @@ SYM_INNER_LABEL(common_startup_64, SYM_L_LOCAL)
 	movl %eax,%fs
 	movl %eax,%gs
 
-	/* Set up %gs.
-	 *
-	 * The base of %gs always points to fixed_percpu_data.
+	/*
+	 * Set up GSBASE.
 	 * Note that, on SMP, the boot cpu uses init data section until
 	 * the per cpu areas are set up.
 	 */
 	movl	$MSR_GS_BASE,%ecx
-#ifndef CONFIG_SMP
-	leaq	INIT_PER_CPU_VAR(fixed_percpu_data)(%rip), %rdx
-#endif
 	movl	%edx, %eax
 	shrq	$32, %rdx
 	wrmsr
diff --git a/arch/x86/kernel/setup_percpu.c b/arch/x86/kernel/setup_percpu.c
index b30d6e180df7..1e7be9409aa2 100644
--- a/arch/x86/kernel/setup_percpu.c
+++ b/arch/x86/kernel/setup_percpu.c
@@ -23,18 +23,10 @@
 #include <asm/cpumask.h>
 #include <asm/cpu.h>
 
-#ifdef CONFIG_X86_64
-#define BOOT_PERCPU_OFFSET ((unsigned long)__per_cpu_load)
-#else
-#define BOOT_PERCPU_OFFSET 0
-#endif
-
-DEFINE_PER_CPU_READ_MOSTLY(unsigned long, this_cpu_off) = BOOT_PERCPU_OFFSET;
+DEFINE_PER_CPU_READ_MOSTLY(unsigned long, this_cpu_off);
 EXPORT_PER_CPU_SYMBOL(this_cpu_off);
 
-unsigned long __per_cpu_offset[NR_CPUS] __ro_after_init = {
-	[0 ... NR_CPUS-1] = BOOT_PERCPU_OFFSET,
-};
+unsigned long __per_cpu_offset[NR_CPUS] __ro_after_init;
 EXPORT_SYMBOL(__per_cpu_offset);
 
 /*
diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index d61c3584f3e6..42d1c05b0207 100644
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -99,12 +99,6 @@ const_pcpu_hot = pcpu_hot;
 PHDRS {
 	text PT_LOAD FLAGS(5);          /* R_E */
 	data PT_LOAD FLAGS(6);          /* RW_ */
-#ifdef CONFIG_X86_64
-#ifdef CONFIG_SMP
-	percpu PT_LOAD FLAGS(6);        /* RW_ */
-#endif
-	init PT_LOAD FLAGS(7);          /* RWE */
-#endif
 	note PT_NOTE FLAGS(0);          /* ___ */
 }
 
@@ -199,21 +193,7 @@ SECTIONS
 		__init_begin = .; /* paired with __init_end */
 	}
 
-#if defined(CONFIG_X86_64) && defined(CONFIG_SMP)
-	/*
-	 * percpu offsets are zero-based on SMP.  PERCPU_VADDR() changes the
-	 * output PHDR, so the next output section - .init.text - should
-	 * start another segment - init.
-	 */
-	PERCPU_VADDR(INTERNODE_CACHE_BYTES, 0, :percpu)
-	ASSERT(SIZEOF(.data..percpu) < CONFIG_PHYSICAL_START,
-	       "per-CPU data too large - increase CONFIG_PHYSICAL_START")
-#endif
-
 	INIT_TEXT_SECTION(PAGE_SIZE)
-#ifdef CONFIG_X86_64
-	:init
-#endif
 
 	/*
 	 * Section for code used exclusively before alternatives are run. All
@@ -330,9 +310,7 @@ SECTIONS
 		EXIT_DATA
 	}
 
-#if !defined(CONFIG_X86_64) || !defined(CONFIG_SMP)
 	PERCPU_SECTION(INTERNODE_CACHE_BYTES)
-#endif
 
 	RUNTIME_CONST_VARIABLES
 	RUNTIME_CONST(ptr, USER_PTR_MAX)
@@ -476,16 +454,11 @@ PROVIDE(__ref_stack_chk_guard = __stack_chk_guard);
  * Per-cpu symbols which need to be offset from __per_cpu_load
  * for the boot processor.
  */
-#define INIT_PER_CPU(x) init_per_cpu__##x = ABSOLUTE(x) + __per_cpu_load
+#define INIT_PER_CPU(x) init_per_cpu__##x = ABSOLUTE(x)
 INIT_PER_CPU(gdt_page);
 INIT_PER_CPU(fixed_percpu_data);
 INIT_PER_CPU(irq_stack_backing_store);
 
-#ifdef CONFIG_SMP
-. = ASSERT((fixed_percpu_data == 0),
-           "fixed_percpu_data is not at start of per-cpu area");
-#endif
-
 #ifdef CONFIG_MITIGATION_UNRET_ENTRY
 . = ASSERT((retbleed_return_thunk & 0x3f) == 0, "retbleed_return_thunk not cacheline-aligned");
 #endif
diff --git a/arch/x86/platform/pvh/head.S b/arch/x86/platform/pvh/head.S
index b0a9a58952aa..c931e680ef15 100644
--- a/arch/x86/platform/pvh/head.S
+++ b/arch/x86/platform/pvh/head.S
@@ -165,9 +165,8 @@ SYM_CODE_START_LOCAL(pvh_start_xen)
 	 * the per cpu areas are set up.
 	 */
 	movl $MSR_GS_BASE,%ecx
-	leaq INIT_PER_CPU_VAR(fixed_percpu_data)(%rip), %rdx
-	movq %edx, %eax
-	shrq $32, %rdx
+	xorl %eax, %eax
+	xorl %edx, %edx
 	wrmsr
 
 	/*
diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c
index 7d7fc7f0a250..8b5e2bc3d241 100644
--- a/arch/x86/tools/relocs.c
+++ b/arch/x86/tools/relocs.c
@@ -834,12 +834,7 @@ static void percpu_init(void)
  */
 static int is_percpu_sym(ElfW(Sym) *sym, const char *symname)
 {
-	int shndx = sym_index(sym);
-
-	return (shndx == per_cpu_shndx) &&
-		strcmp(symname, "__init_begin") &&
-		strcmp(symname, "__per_cpu_load") &&
-		strncmp(symname, "init_per_cpu_", 13);
+	return 0;
 }
 
 
@@ -1055,7 +1050,8 @@ static int cmp_relocs(const void *va, const void *vb)
 
 static void sort_relocs(struct relocs *r)
 {
-	qsort(r->offset, r->count, sizeof(r->offset[0]), cmp_relocs);
+	if (r->count)
+		qsort(r->offset, r->count, sizeof(r->offset[0]), cmp_relocs);
 }
 
 static int write32(uint32_t v, FILE *f)
diff --git a/arch/x86/xen/xen-head.S b/arch/x86/xen/xen-head.S
index ae4672ea00bb..1796884b727d 100644
--- a/arch/x86/xen/xen-head.S
+++ b/arch/x86/xen/xen-head.S
@@ -51,15 +51,14 @@ SYM_CODE_START(startup_xen)
 
 	leaq	__top_init_kernel_stack(%rip), %rsp
 
-	/* Set up %gs.
-	 *
-	 * The base of %gs always points to fixed_percpu_data.
+	/*
+	 * Set up GSBASE.
 	 * Note that, on SMP, the boot cpu uses init data section until
 	 * the per cpu areas are set up.
 	 */
 	movl	$MSR_GS_BASE,%ecx
-	movq	$INIT_PER_CPU_VAR(fixed_percpu_data),%rax
-	cdq
+	xorl	%eax, %eax
+	xorl	%edx, %edx
 	wrmsr
 
 	mov	%rsi, %rdi
diff --git a/init/Kconfig b/init/Kconfig
index c521e1421ad4..b374c0de5cfd 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1849,7 +1849,7 @@ config KALLSYMS_ALL
 config KALLSYMS_ABSOLUTE_PERCPU
 	bool
 	depends on KALLSYMS
-	default X86_64 && SMP
+	default n
 
 # end of the "standard kernel features (expert users)" menu
 
-- 
2.47.0


^ permalink raw reply related	[flat|nested] 67+ messages in thread

* Re: [PATCH v5 09/16] x86/percpu/64: Use relative percpu offsets
  2024-11-05 15:57 ` [PATCH v5 09/16] x86/percpu/64: Use relative percpu offsets Brian Gerst
@ 2024-11-07 11:28   ` Uros Bizjak
  2024-11-07 12:05     ` Brian Gerst
  0 siblings, 1 reply; 67+ messages in thread
From: Uros Bizjak @ 2024-11-07 11:28 UTC (permalink / raw)
  To: Brian Gerst
  Cc: linux-kernel, x86, Ingo Molnar, H . Peter Anvin, Thomas Gleixner,
	Borislav Petkov, Ard Biesheuvel

On Tue, Nov 5, 2024 at 4:58 PM Brian Gerst <brgerst@gmail.com> wrote:
>
> The percpu section is currently linked at absolute address 0, because
> older compilers hardcoded the stack protector canary value at a fixed
> offset from the start of the GS segment.  Now that the canary is a
> normal percpu variable, the percpu section does not need to be linked
> at a specific address.
>
> x86-64 will now calculate the percpu offsets as the delta between the
> initial percpu address and the dynamically allocated memory, like other
> architectures.  Note that GSBASE is limited to the canonical address
> width (48 or 57 bits, sign-extended).  As long as the kernel text,
> modules, and the dynamically allocated percpu memmory are all in the
> negative address space, the delta will not overflow this limit.
>
> Signed-off-by: Brian Gerst <brgerst@gmail.com>
> ---
>  arch/x86/include/asm/processor.h |  6 +++++-
>  arch/x86/kernel/head_64.S        | 19 +++++++++----------
>  arch/x86/kernel/setup_percpu.c   | 12 ++----------
>  arch/x86/kernel/vmlinux.lds.S    | 29 +----------------------------
>  arch/x86/platform/pvh/head.S     |  5 ++---
>  arch/x86/tools/relocs.c          | 10 +++-------
>  arch/x86/xen/xen-head.S          |  9 ++++-----
>  init/Kconfig                     |  2 +-
>  8 files changed, 27 insertions(+), 65 deletions(-)
>
> diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
> index a113c3f4f558..ae50d5d4fa26 100644
> --- a/arch/x86/include/asm/processor.h
> +++ b/arch/x86/include/asm/processor.h
> @@ -428,7 +428,11 @@ DECLARE_INIT_PER_CPU(fixed_percpu_data);
>
>  static inline unsigned long cpu_kernelmode_gs_base(int cpu)
>  {
> -       return (unsigned long)per_cpu(fixed_percpu_data.gs_base, cpu);
> +#ifdef CONFIG_SMP
> +       return per_cpu_offset(cpu);
> +#else
> +       return 0;
> +#endif
>  }
>
>  extern asmlinkage void entry_SYSCALL32_ignore(void);
> diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
> index c3028b4df85f..ffbcb0aea450 100644
> --- a/arch/x86/kernel/head_64.S
> +++ b/arch/x86/kernel/head_64.S
> @@ -61,11 +61,14 @@ SYM_CODE_START_NOALIGN(startup_64)
>         /* Set up the stack for verify_cpu() */
>         leaq    __top_init_kernel_stack(%rip), %rsp
>
> -       /* Setup GSBASE to allow stack canary access for C code */
> +       /*
> +        * Set up GSBASE.
> +        * Note that, on SMP, the boot cpu uses init data section until
> +        * the per cpu areas are set up.
> +        */
>         movl    $MSR_GS_BASE, %ecx
> -       leaq    INIT_PER_CPU_VAR(fixed_percpu_data)(%rip), %rdx
> -       movl    %edx, %eax
> -       shrq    $32,  %rdx
> +       xorl    %eax, %eax
> +       xorl    %edx, %edx

You can use cltd after "xor %eax, %eax", it is one byte shorter with
the same effect ...

>         wrmsr
>
>         call    startup_64_setup_gdt_idt
> @@ -353,16 +356,12 @@ SYM_INNER_LABEL(common_startup_64, SYM_L_LOCAL)
>         movl %eax,%fs
>         movl %eax,%gs
>
> -       /* Set up %gs.
> -        *
> -        * The base of %gs always points to fixed_percpu_data.
> +       /*
> +        * Set up GSBASE.
>          * Note that, on SMP, the boot cpu uses init data section until
>          * the per cpu areas are set up.
>          */
>         movl    $MSR_GS_BASE,%ecx
> -#ifndef CONFIG_SMP
> -       leaq    INIT_PER_CPU_VAR(fixed_percpu_data)(%rip), %rdx
> -#endif
>         movl    %edx, %eax
>         shrq    $32, %rdx
>         wrmsr
> diff --git a/arch/x86/kernel/setup_percpu.c b/arch/x86/kernel/setup_percpu.c
> index b30d6e180df7..1e7be9409aa2 100644
> --- a/arch/x86/kernel/setup_percpu.c
> +++ b/arch/x86/kernel/setup_percpu.c
> @@ -23,18 +23,10 @@
>  #include <asm/cpumask.h>
>  #include <asm/cpu.h>
>
> -#ifdef CONFIG_X86_64
> -#define BOOT_PERCPU_OFFSET ((unsigned long)__per_cpu_load)
> -#else
> -#define BOOT_PERCPU_OFFSET 0
> -#endif
> -
> -DEFINE_PER_CPU_READ_MOSTLY(unsigned long, this_cpu_off) = BOOT_PERCPU_OFFSET;
> +DEFINE_PER_CPU_READ_MOSTLY(unsigned long, this_cpu_off);
>  EXPORT_PER_CPU_SYMBOL(this_cpu_off);
>
> -unsigned long __per_cpu_offset[NR_CPUS] __ro_after_init = {
> -       [0 ... NR_CPUS-1] = BOOT_PERCPU_OFFSET,
> -};
> +unsigned long __per_cpu_offset[NR_CPUS] __ro_after_init;
>  EXPORT_SYMBOL(__per_cpu_offset);
>
>  /*
> diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
> index d61c3584f3e6..42d1c05b0207 100644
> --- a/arch/x86/kernel/vmlinux.lds.S
> +++ b/arch/x86/kernel/vmlinux.lds.S
> @@ -99,12 +99,6 @@ const_pcpu_hot = pcpu_hot;
>  PHDRS {
>         text PT_LOAD FLAGS(5);          /* R_E */
>         data PT_LOAD FLAGS(6);          /* RW_ */
> -#ifdef CONFIG_X86_64
> -#ifdef CONFIG_SMP
> -       percpu PT_LOAD FLAGS(6);        /* RW_ */
> -#endif
> -       init PT_LOAD FLAGS(7);          /* RWE */
> -#endif
>         note PT_NOTE FLAGS(0);          /* ___ */
>  }
>
> @@ -199,21 +193,7 @@ SECTIONS
>                 __init_begin = .; /* paired with __init_end */
>         }
>
> -#if defined(CONFIG_X86_64) && defined(CONFIG_SMP)
> -       /*
> -        * percpu offsets are zero-based on SMP.  PERCPU_VADDR() changes the
> -        * output PHDR, so the next output section - .init.text - should
> -        * start another segment - init.
> -        */
> -       PERCPU_VADDR(INTERNODE_CACHE_BYTES, 0, :percpu)
> -       ASSERT(SIZEOF(.data..percpu) < CONFIG_PHYSICAL_START,
> -              "per-CPU data too large - increase CONFIG_PHYSICAL_START")
> -#endif
> -
>         INIT_TEXT_SECTION(PAGE_SIZE)
> -#ifdef CONFIG_X86_64
> -       :init
> -#endif
>
>         /*
>          * Section for code used exclusively before alternatives are run. All
> @@ -330,9 +310,7 @@ SECTIONS
>                 EXIT_DATA
>         }
>
> -#if !defined(CONFIG_X86_64) || !defined(CONFIG_SMP)
>         PERCPU_SECTION(INTERNODE_CACHE_BYTES)
> -#endif
>
>         RUNTIME_CONST_VARIABLES
>         RUNTIME_CONST(ptr, USER_PTR_MAX)
> @@ -476,16 +454,11 @@ PROVIDE(__ref_stack_chk_guard = __stack_chk_guard);
>   * Per-cpu symbols which need to be offset from __per_cpu_load
>   * for the boot processor.
>   */
> -#define INIT_PER_CPU(x) init_per_cpu__##x = ABSOLUTE(x) + __per_cpu_load
> +#define INIT_PER_CPU(x) init_per_cpu__##x = ABSOLUTE(x)
>  INIT_PER_CPU(gdt_page);
>  INIT_PER_CPU(fixed_percpu_data);
>  INIT_PER_CPU(irq_stack_backing_store);
>
> -#ifdef CONFIG_SMP
> -. = ASSERT((fixed_percpu_data == 0),
> -           "fixed_percpu_data is not at start of per-cpu area");
> -#endif
> -
>  #ifdef CONFIG_MITIGATION_UNRET_ENTRY
>  . = ASSERT((retbleed_return_thunk & 0x3f) == 0, "retbleed_return_thunk not cacheline-aligned");
>  #endif
> diff --git a/arch/x86/platform/pvh/head.S b/arch/x86/platform/pvh/head.S
> index b0a9a58952aa..c931e680ef15 100644
> --- a/arch/x86/platform/pvh/head.S
> +++ b/arch/x86/platform/pvh/head.S
> @@ -165,9 +165,8 @@ SYM_CODE_START_LOCAL(pvh_start_xen)
>          * the per cpu areas are set up.
>          */
>         movl $MSR_GS_BASE,%ecx
> -       leaq INIT_PER_CPU_VAR(fixed_percpu_data)(%rip), %rdx
> -       movq %edx, %eax
> -       shrq $32, %rdx
> +       xorl %eax, %eax
> +       xorl %edx, %edx

... also here ...

>         wrmsr
>
>         /*
> diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c
> index 7d7fc7f0a250..8b5e2bc3d241 100644
> --- a/arch/x86/tools/relocs.c
> +++ b/arch/x86/tools/relocs.c
> @@ -834,12 +834,7 @@ static void percpu_init(void)
>   */
>  static int is_percpu_sym(ElfW(Sym) *sym, const char *symname)
>  {
> -       int shndx = sym_index(sym);
> -
> -       return (shndx == per_cpu_shndx) &&
> -               strcmp(symname, "__init_begin") &&
> -               strcmp(symname, "__per_cpu_load") &&
> -               strncmp(symname, "init_per_cpu_", 13);
> +       return 0;
>  }
>
>
> @@ -1055,7 +1050,8 @@ static int cmp_relocs(const void *va, const void *vb)
>
>  static void sort_relocs(struct relocs *r)
>  {
> -       qsort(r->offset, r->count, sizeof(r->offset[0]), cmp_relocs);
> +       if (r->count)
> +               qsort(r->offset, r->count, sizeof(r->offset[0]), cmp_relocs);
>  }
>
>  static int write32(uint32_t v, FILE *f)
> diff --git a/arch/x86/xen/xen-head.S b/arch/x86/xen/xen-head.S
> index ae4672ea00bb..1796884b727d 100644
> --- a/arch/x86/xen/xen-head.S
> +++ b/arch/x86/xen/xen-head.S
> @@ -51,15 +51,14 @@ SYM_CODE_START(startup_xen)
>
>         leaq    __top_init_kernel_stack(%rip), %rsp
>
> -       /* Set up %gs.
> -        *
> -        * The base of %gs always points to fixed_percpu_data.
> +       /*
> +        * Set up GSBASE.
>          * Note that, on SMP, the boot cpu uses init data section until
>          * the per cpu areas are set up.
>          */
>         movl    $MSR_GS_BASE,%ecx
> -       movq    $INIT_PER_CPU_VAR(fixed_percpu_data),%rax
> -       cdq
> +       xorl    %eax, %eax
> +       xorl    %edx, %edx

... and here.

Uros.

>         wrmsr
>
>         mov     %rsi, %rdi
> diff --git a/init/Kconfig b/init/Kconfig
> index c521e1421ad4..b374c0de5cfd 100644
> --- a/init/Kconfig
> +++ b/init/Kconfig
> @@ -1849,7 +1849,7 @@ config KALLSYMS_ALL
>  config KALLSYMS_ABSOLUTE_PERCPU
>         bool
>         depends on KALLSYMS
> -       default X86_64 && SMP
> +       default n
>
>  # end of the "standard kernel features (expert users)" menu
>
> --
> 2.47.0
>

^ permalink raw reply	[flat|nested] 67+ messages in thread

* Re: [PATCH v5 09/16] x86/percpu/64: Use relative percpu offsets
  2024-11-07 11:28   ` Uros Bizjak
@ 2024-11-07 12:05     ` Brian Gerst
  2024-11-07 13:34       ` Uros Bizjak
  0 siblings, 1 reply; 67+ messages in thread
From: Brian Gerst @ 2024-11-07 12:05 UTC (permalink / raw)
  To: Uros Bizjak
  Cc: linux-kernel, x86, Ingo Molnar, H . Peter Anvin, Thomas Gleixner,
	Borislav Petkov, Ard Biesheuvel

On Thu, Nov 7, 2024 at 6:28 AM Uros Bizjak <ubizjak@gmail.com> wrote:
>
> On Tue, Nov 5, 2024 at 4:58 PM Brian Gerst <brgerst@gmail.com> wrote:
> >
> > The percpu section is currently linked at absolute address 0, because
> > older compilers hardcoded the stack protector canary value at a fixed
> > offset from the start of the GS segment.  Now that the canary is a
> > normal percpu variable, the percpu section does not need to be linked
> > at a specific address.
> >
> > x86-64 will now calculate the percpu offsets as the delta between the
> > initial percpu address and the dynamically allocated memory, like other
> > architectures.  Note that GSBASE is limited to the canonical address
> > width (48 or 57 bits, sign-extended).  As long as the kernel text,
> > modules, and the dynamically allocated percpu memmory are all in the
> > negative address space, the delta will not overflow this limit.
> >
> > Signed-off-by: Brian Gerst <brgerst@gmail.com>
> > ---
> >  arch/x86/include/asm/processor.h |  6 +++++-
> >  arch/x86/kernel/head_64.S        | 19 +++++++++----------
> >  arch/x86/kernel/setup_percpu.c   | 12 ++----------
> >  arch/x86/kernel/vmlinux.lds.S    | 29 +----------------------------
> >  arch/x86/platform/pvh/head.S     |  5 ++---
> >  arch/x86/tools/relocs.c          | 10 +++-------
> >  arch/x86/xen/xen-head.S          |  9 ++++-----
> >  init/Kconfig                     |  2 +-
> >  8 files changed, 27 insertions(+), 65 deletions(-)
> >
> > diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
> > index a113c3f4f558..ae50d5d4fa26 100644
> > --- a/arch/x86/include/asm/processor.h
> > +++ b/arch/x86/include/asm/processor.h
> > @@ -428,7 +428,11 @@ DECLARE_INIT_PER_CPU(fixed_percpu_data);
> >
> >  static inline unsigned long cpu_kernelmode_gs_base(int cpu)
> >  {
> > -       return (unsigned long)per_cpu(fixed_percpu_data.gs_base, cpu);
> > +#ifdef CONFIG_SMP
> > +       return per_cpu_offset(cpu);
> > +#else
> > +       return 0;
> > +#endif
> >  }
> >
> >  extern asmlinkage void entry_SYSCALL32_ignore(void);
> > diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
> > index c3028b4df85f..ffbcb0aea450 100644
> > --- a/arch/x86/kernel/head_64.S
> > +++ b/arch/x86/kernel/head_64.S
> > @@ -61,11 +61,14 @@ SYM_CODE_START_NOALIGN(startup_64)
> >         /* Set up the stack for verify_cpu() */
> >         leaq    __top_init_kernel_stack(%rip), %rsp
> >
> > -       /* Setup GSBASE to allow stack canary access for C code */
> > +       /*
> > +        * Set up GSBASE.
> > +        * Note that, on SMP, the boot cpu uses init data section until
> > +        * the per cpu areas are set up.
> > +        */
> >         movl    $MSR_GS_BASE, %ecx
> > -       leaq    INIT_PER_CPU_VAR(fixed_percpu_data)(%rip), %rdx
> > -       movl    %edx, %eax
> > -       shrq    $32,  %rdx
> > +       xorl    %eax, %eax
> > +       xorl    %edx, %edx
>
> You can use cltd after "xor %eax, %eax", it is one byte shorter with
> the same effect ...

I suppose that would work, but I'm not sure it's worth it to
hyper-optimize boot code like this.  It's also confusing since the SDM
calls this instruction CDQ instead of CLTD.

Brian Gerst

^ permalink raw reply	[flat|nested] 67+ messages in thread

* Re: [PATCH v5 09/16] x86/percpu/64: Use relative percpu offsets
  2024-11-07 12:05     ` Brian Gerst
@ 2024-11-07 13:34       ` Uros Bizjak
  0 siblings, 0 replies; 67+ messages in thread
From: Uros Bizjak @ 2024-11-07 13:34 UTC (permalink / raw)
  To: Brian Gerst
  Cc: linux-kernel, x86, Ingo Molnar, H . Peter Anvin, Thomas Gleixner,
	Borislav Petkov, Ard Biesheuvel

On Thu, Nov 7, 2024 at 1:05 PM Brian Gerst <brgerst@gmail.com> wrote:
>
> On Thu, Nov 7, 2024 at 6:28 AM Uros Bizjak <ubizjak@gmail.com> wrote:
> >
> > On Tue, Nov 5, 2024 at 4:58 PM Brian Gerst <brgerst@gmail.com> wrote:
> > >
> > > The percpu section is currently linked at absolute address 0, because
> > > older compilers hardcoded the stack protector canary value at a fixed
> > > offset from the start of the GS segment.  Now that the canary is a
> > > normal percpu variable, the percpu section does not need to be linked
> > > at a specific address.
> > >
> > > x86-64 will now calculate the percpu offsets as the delta between the
> > > initial percpu address and the dynamically allocated memory, like other
> > > architectures.  Note that GSBASE is limited to the canonical address
> > > width (48 or 57 bits, sign-extended).  As long as the kernel text,
> > > modules, and the dynamically allocated percpu memmory are all in the
> > > negative address space, the delta will not overflow this limit.
> > >
> > > Signed-off-by: Brian Gerst <brgerst@gmail.com>
> > > ---
> > >  arch/x86/include/asm/processor.h |  6 +++++-
> > >  arch/x86/kernel/head_64.S        | 19 +++++++++----------
> > >  arch/x86/kernel/setup_percpu.c   | 12 ++----------
> > >  arch/x86/kernel/vmlinux.lds.S    | 29 +----------------------------
> > >  arch/x86/platform/pvh/head.S     |  5 ++---
> > >  arch/x86/tools/relocs.c          | 10 +++-------
> > >  arch/x86/xen/xen-head.S          |  9 ++++-----
> > >  init/Kconfig                     |  2 +-
> > >  8 files changed, 27 insertions(+), 65 deletions(-)
> > >
> > > diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
> > > index a113c3f4f558..ae50d5d4fa26 100644
> > > --- a/arch/x86/include/asm/processor.h
> > > +++ b/arch/x86/include/asm/processor.h
> > > @@ -428,7 +428,11 @@ DECLARE_INIT_PER_CPU(fixed_percpu_data);
> > >
> > >  static inline unsigned long cpu_kernelmode_gs_base(int cpu)
> > >  {
> > > -       return (unsigned long)per_cpu(fixed_percpu_data.gs_base, cpu);
> > > +#ifdef CONFIG_SMP
> > > +       return per_cpu_offset(cpu);
> > > +#else
> > > +       return 0;
> > > +#endif
> > >  }
> > >
> > >  extern asmlinkage void entry_SYSCALL32_ignore(void);
> > > diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
> > > index c3028b4df85f..ffbcb0aea450 100644
> > > --- a/arch/x86/kernel/head_64.S
> > > +++ b/arch/x86/kernel/head_64.S
> > > @@ -61,11 +61,14 @@ SYM_CODE_START_NOALIGN(startup_64)
> > >         /* Set up the stack for verify_cpu() */
> > >         leaq    __top_init_kernel_stack(%rip), %rsp
> > >
> > > -       /* Setup GSBASE to allow stack canary access for C code */
> > > +       /*
> > > +        * Set up GSBASE.
> > > +        * Note that, on SMP, the boot cpu uses init data section until
> > > +        * the per cpu areas are set up.
> > > +        */
> > >         movl    $MSR_GS_BASE, %ecx
> > > -       leaq    INIT_PER_CPU_VAR(fixed_percpu_data)(%rip), %rdx
> > > -       movl    %edx, %eax
> > > -       shrq    $32,  %rdx
> > > +       xorl    %eax, %eax
> > > +       xorl    %edx, %edx
> >
> > You can use cltd after "xor %eax, %eax", it is one byte shorter with
> > the same effect ...
>
> I suppose that would work, but I'm not sure it's worth it to
> hyper-optimize boot code like this.  It's also confusing since the SDM
> calls this instruction CDQ instead of CLTD.

No big deal, indeed.

Reviewed-by: Uros Bizjak <ubizjak@gmail.com>

^ permalink raw reply	[flat|nested] 67+ messages in thread

* [PATCH v5 10/16] x86/percpu/64: Remove fixed_percpu_data
  2024-11-05 15:57 [PATCH v5 00/16] x86-64: Stack protector and percpu improvements Brian Gerst
                   ` (8 preceding siblings ...)
  2024-11-05 15:57 ` [PATCH v5 09/16] x86/percpu/64: Use relative percpu offsets Brian Gerst
@ 2024-11-05 15:57 ` Brian Gerst
  2024-11-07 13:32   ` Uros Bizjak
  2024-11-05 15:57 ` [PATCH v5 11/16] x86/boot/64: Remove inverse relocations Brian Gerst
                   ` (7 subsequent siblings)
  17 siblings, 1 reply; 67+ messages in thread
From: Brian Gerst @ 2024-11-05 15:57 UTC (permalink / raw)
  To: linux-kernel, x86
  Cc: Ingo Molnar, H . Peter Anvin, Thomas Gleixner, Borislav Petkov,
	Ard Biesheuvel, Uros Bizjak, Brian Gerst

Now that the stack protector canary value is a normal percpu variable,
fixed_percpu_data is unused and can be removed.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
---
 arch/x86/include/asm/processor.h | 8 --------
 arch/x86/kernel/cpu/common.c     | 4 ----
 arch/x86/kernel/vmlinux.lds.S    | 1 -
 arch/x86/tools/relocs.c          | 1 -
 4 files changed, 14 deletions(-)

diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index ae50d5d4fa26..e1b856e2f944 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -418,14 +418,6 @@ struct irq_stack {
 } __aligned(IRQ_STACK_SIZE);
 
 #ifdef CONFIG_X86_64
-struct fixed_percpu_data {
-	char		gs_base[40];
-	unsigned long	reserved;
-};
-
-DECLARE_PER_CPU_FIRST(struct fixed_percpu_data, fixed_percpu_data) __visible;
-DECLARE_INIT_PER_CPU(fixed_percpu_data);
-
 static inline unsigned long cpu_kernelmode_gs_base(int cpu)
 {
 #ifdef CONFIG_SMP
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 1f33d5feb050..d6102e772c7e 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -2020,10 +2020,6 @@ EXPORT_PER_CPU_SYMBOL(pcpu_hot);
 EXPORT_PER_CPU_SYMBOL(const_pcpu_hot);
 
 #ifdef CONFIG_X86_64
-DEFINE_PER_CPU_FIRST(struct fixed_percpu_data,
-		     fixed_percpu_data) __aligned(PAGE_SIZE) __visible;
-EXPORT_PER_CPU_SYMBOL_GPL(fixed_percpu_data);
-
 static void wrmsrl_cstar(unsigned long val)
 {
 	/*
diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index 42d1c05b0207..859ff7c0dc02 100644
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -456,7 +456,6 @@ PROVIDE(__ref_stack_chk_guard = __stack_chk_guard);
  */
 #define INIT_PER_CPU(x) init_per_cpu__##x = ABSOLUTE(x)
 INIT_PER_CPU(gdt_page);
-INIT_PER_CPU(fixed_percpu_data);
 INIT_PER_CPU(irq_stack_backing_store);
 
 #ifdef CONFIG_MITIGATION_UNRET_ENTRY
diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c
index 8b5e2bc3d241..a661a6bab4cf 100644
--- a/arch/x86/tools/relocs.c
+++ b/arch/x86/tools/relocs.c
@@ -829,7 +829,6 @@ static void percpu_init(void)
  *	__per_cpu_load
  *
  * The "gold" linker incorrectly associates:
- *	init_per_cpu__fixed_percpu_data
  *	init_per_cpu__gdt_page
  */
 static int is_percpu_sym(ElfW(Sym) *sym, const char *symname)
-- 
2.47.0


^ permalink raw reply related	[flat|nested] 67+ messages in thread

* Re: [PATCH v5 10/16] x86/percpu/64: Remove fixed_percpu_data
  2024-11-05 15:57 ` [PATCH v5 10/16] x86/percpu/64: Remove fixed_percpu_data Brian Gerst
@ 2024-11-07 13:32   ` Uros Bizjak
  0 siblings, 0 replies; 67+ messages in thread
From: Uros Bizjak @ 2024-11-07 13:32 UTC (permalink / raw)
  To: Brian Gerst
  Cc: linux-kernel, x86, Ingo Molnar, H . Peter Anvin, Thomas Gleixner,
	Borislav Petkov, Ard Biesheuvel

On Tue, Nov 5, 2024 at 4:58 PM Brian Gerst <brgerst@gmail.com> wrote:
>
> Now that the stack protector canary value is a normal percpu variable,
> fixed_percpu_data is unused and can be removed.
>
> Signed-off-by: Brian Gerst <brgerst@gmail.com>

Reviewed-by: Uros Bizjak <ubizjak@gmail.com>

> ---
>  arch/x86/include/asm/processor.h | 8 --------
>  arch/x86/kernel/cpu/common.c     | 4 ----
>  arch/x86/kernel/vmlinux.lds.S    | 1 -
>  arch/x86/tools/relocs.c          | 1 -
>  4 files changed, 14 deletions(-)
>
> diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
> index ae50d5d4fa26..e1b856e2f944 100644
> --- a/arch/x86/include/asm/processor.h
> +++ b/arch/x86/include/asm/processor.h
> @@ -418,14 +418,6 @@ struct irq_stack {
>  } __aligned(IRQ_STACK_SIZE);
>
>  #ifdef CONFIG_X86_64
> -struct fixed_percpu_data {
> -       char            gs_base[40];
> -       unsigned long   reserved;
> -};
> -
> -DECLARE_PER_CPU_FIRST(struct fixed_percpu_data, fixed_percpu_data) __visible;
> -DECLARE_INIT_PER_CPU(fixed_percpu_data);
> -
>  static inline unsigned long cpu_kernelmode_gs_base(int cpu)
>  {
>  #ifdef CONFIG_SMP
> diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
> index 1f33d5feb050..d6102e772c7e 100644
> --- a/arch/x86/kernel/cpu/common.c
> +++ b/arch/x86/kernel/cpu/common.c
> @@ -2020,10 +2020,6 @@ EXPORT_PER_CPU_SYMBOL(pcpu_hot);
>  EXPORT_PER_CPU_SYMBOL(const_pcpu_hot);
>
>  #ifdef CONFIG_X86_64
> -DEFINE_PER_CPU_FIRST(struct fixed_percpu_data,
> -                    fixed_percpu_data) __aligned(PAGE_SIZE) __visible;
> -EXPORT_PER_CPU_SYMBOL_GPL(fixed_percpu_data);
> -
>  static void wrmsrl_cstar(unsigned long val)
>  {
>         /*
> diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
> index 42d1c05b0207..859ff7c0dc02 100644
> --- a/arch/x86/kernel/vmlinux.lds.S
> +++ b/arch/x86/kernel/vmlinux.lds.S
> @@ -456,7 +456,6 @@ PROVIDE(__ref_stack_chk_guard = __stack_chk_guard);
>   */
>  #define INIT_PER_CPU(x) init_per_cpu__##x = ABSOLUTE(x)
>  INIT_PER_CPU(gdt_page);
> -INIT_PER_CPU(fixed_percpu_data);
>  INIT_PER_CPU(irq_stack_backing_store);
>
>  #ifdef CONFIG_MITIGATION_UNRET_ENTRY
> diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c
> index 8b5e2bc3d241..a661a6bab4cf 100644
> --- a/arch/x86/tools/relocs.c
> +++ b/arch/x86/tools/relocs.c
> @@ -829,7 +829,6 @@ static void percpu_init(void)
>   *     __per_cpu_load
>   *
>   * The "gold" linker incorrectly associates:
> - *     init_per_cpu__fixed_percpu_data
>   *     init_per_cpu__gdt_page
>   */
>  static int is_percpu_sym(ElfW(Sym) *sym, const char *symname)
> --
> 2.47.0
>

^ permalink raw reply	[flat|nested] 67+ messages in thread

* [PATCH v5 11/16] x86/boot/64: Remove inverse relocations
  2024-11-05 15:57 [PATCH v5 00/16] x86-64: Stack protector and percpu improvements Brian Gerst
                   ` (9 preceding siblings ...)
  2024-11-05 15:57 ` [PATCH v5 10/16] x86/percpu/64: Remove fixed_percpu_data Brian Gerst
@ 2024-11-05 15:57 ` Brian Gerst
  2024-11-05 15:57 ` [PATCH v5 12/16] x86/percpu/64: Remove INIT_PER_CPU macros Brian Gerst
                   ` (6 subsequent siblings)
  17 siblings, 0 replies; 67+ messages in thread
From: Brian Gerst @ 2024-11-05 15:57 UTC (permalink / raw)
  To: linux-kernel, x86
  Cc: Ingo Molnar, H . Peter Anvin, Thomas Gleixner, Borislav Petkov,
	Ard Biesheuvel, Uros Bizjak, Brian Gerst

Inverse relocations were needed to offset the effects of relocation for
RIP-relative accesses to zero-based percpu data.  Now that the percpu
section is linked normally as part of the kernel image, they are no
longer needed.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
---
 arch/x86/boot/compressed/misc.c |  14 +---
 arch/x86/tools/relocs.c         | 130 +-------------------------------
 2 files changed, 2 insertions(+), 142 deletions(-)

diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c
index 0d37420cad02..1cdcd4aaf395 100644
--- a/arch/x86/boot/compressed/misc.c
+++ b/arch/x86/boot/compressed/misc.c
@@ -235,7 +235,7 @@ static void handle_relocations(void *output, unsigned long output_len,
 
 	/*
 	 * Process relocations: 32 bit relocations first then 64 bit after.
-	 * Three sets of binary relocations are added to the end of the kernel
+	 * Two sets of binary relocations are added to the end of the kernel
 	 * before compression. Each relocation table entry is the kernel
 	 * address of the location which needs to be updated stored as a
 	 * 32-bit value which is sign extended to 64 bits.
@@ -245,8 +245,6 @@ static void handle_relocations(void *output, unsigned long output_len,
 	 * kernel bits...
 	 * 0 - zero terminator for 64 bit relocations
 	 * 64 bit relocation repeated
-	 * 0 - zero terminator for inverse 32 bit relocations
-	 * 32 bit inverse relocation repeated
 	 * 0 - zero terminator for 32 bit relocations
 	 * 32 bit relocation repeated
 	 *
@@ -263,16 +261,6 @@ static void handle_relocations(void *output, unsigned long output_len,
 		*(uint32_t *)ptr += delta;
 	}
 #ifdef CONFIG_X86_64
-	while (*--reloc) {
-		long extended = *reloc;
-		extended += map;
-
-		ptr = (unsigned long)extended;
-		if (ptr < min_addr || ptr > max_addr)
-			error("inverse 32-bit relocation outside of kernel!\n");
-
-		*(int32_t *)ptr -= delta;
-	}
 	for (reloc--; *reloc; reloc--) {
 		long extended = *reloc;
 		extended += map;
diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c
index a661a6bab4cf..8d9e82748615 100644
--- a/arch/x86/tools/relocs.c
+++ b/arch/x86/tools/relocs.c
@@ -29,7 +29,6 @@ static struct relocs		relocs16;
 static struct relocs		relocs32;
 
 #if ELF_BITS == 64
-static struct relocs		relocs32neg;
 static struct relocs		relocs64;
 # define FMT PRIu64
 
@@ -90,7 +89,6 @@ static const char * const	sym_regex_kernel[S_NSYMTYPES] = {
 	"__initramfs_start|"
 	"(jiffies|jiffies_64)|"
 #if ELF_BITS == 64
-	"__per_cpu_load|"
 	"init_per_cpu__.*|"
 	"__end_rodata_hpage_align|"
 #endif
@@ -289,34 +287,6 @@ static const char *sym_name(const char *sym_strtab, Elf_Sym *sym)
 	return name;
 }
 
-static Elf_Sym *sym_lookup(const char *symname)
-{
-	int i;
-
-	for (i = 0; i < shnum; i++) {
-		struct section *sec = &secs[i];
-		long nsyms;
-		char *strtab;
-		Elf_Sym *symtab;
-		Elf_Sym *sym;
-
-		if (sec->shdr.sh_type != SHT_SYMTAB)
-			continue;
-
-		nsyms = sec->shdr.sh_size/sizeof(Elf_Sym);
-		symtab = sec->symtab;
-		strtab = sec->link->strtab;
-
-		for (sym = symtab; --nsyms >= 0; sym++) {
-			if (!sym->st_name)
-				continue;
-			if (strcmp(symname, strtab + sym->st_name) == 0)
-				return sym;
-		}
-	}
-	return 0;
-}
-
 #if BYTE_ORDER == LITTLE_ENDIAN
 # define le16_to_cpu(val)	(val)
 # define le32_to_cpu(val)	(val)
@@ -765,78 +735,8 @@ static void walk_relocs(int (*process)(struct section *sec, Elf_Rel *rel,
 	}
 }
 
-/*
- * The .data..percpu section is a special case for x86_64 SMP kernels.
- * It is used to initialize the actual per_cpu areas and to provide
- * definitions for the per_cpu variables that correspond to their offsets
- * within the percpu area. Since the values of all of the symbols need
- * to be offsets from the start of the per_cpu area the virtual address
- * (sh_addr) of .data..percpu is 0 in SMP kernels.
- *
- * This means that:
- *
- *	Relocations that reference symbols in the per_cpu area do not
- *	need further relocation (since the value is an offset relative
- *	to the start of the per_cpu area that does not change).
- *
- *	Relocations that apply to the per_cpu area need to have their
- *	offset adjusted by by the value of __per_cpu_load to make them
- *	point to the correct place in the loaded image (because the
- *	virtual address of .data..percpu is 0).
- *
- * For non SMP kernels .data..percpu is linked as part of the normal
- * kernel data and does not require special treatment.
- *
- */
-static int per_cpu_shndx = -1;
-static Elf_Addr per_cpu_load_addr;
-
-static void percpu_init(void)
-{
-	int i;
-
-	for (i = 0; i < shnum; i++) {
-		ElfW(Sym) *sym;
-
-		if (strcmp(sec_name(i), ".data..percpu"))
-			continue;
-
-		if (secs[i].shdr.sh_addr != 0)	/* non SMP kernel */
-			return;
-
-		sym = sym_lookup("__per_cpu_load");
-		if (!sym)
-			die("can't find __per_cpu_load\n");
-
-		per_cpu_shndx = i;
-		per_cpu_load_addr = sym->st_value;
-
-		return;
-	}
-}
-
 #if ELF_BITS == 64
 
-/*
- * Check to see if a symbol lies in the .data..percpu section.
- *
- * The linker incorrectly associates some symbols with the
- * .data..percpu section so we also need to check the symbol
- * name to make sure that we classify the symbol correctly.
- *
- * The GNU linker incorrectly associates:
- *	__init_begin
- *	__per_cpu_load
- *
- * The "gold" linker incorrectly associates:
- *	init_per_cpu__gdt_page
- */
-static int is_percpu_sym(ElfW(Sym) *sym, const char *symname)
-{
-	return 0;
-}
-
-
 static int do_reloc64(struct section *sec, Elf_Rel *rel, ElfW(Sym) *sym,
 		      const char *symname)
 {
@@ -847,12 +747,6 @@ static int do_reloc64(struct section *sec, Elf_Rel *rel, ElfW(Sym) *sym,
 	if (sym->st_shndx == SHN_UNDEF)
 		return 0;
 
-	/*
-	 * Adjust the offset if this reloc applies to the percpu section.
-	 */
-	if (sec->shdr.sh_info == per_cpu_shndx)
-		offset += per_cpu_load_addr;
-
 	switch (r_type) {
 	case R_X86_64_NONE:
 		/* NONE can be ignored. */
@@ -862,32 +756,21 @@ static int do_reloc64(struct section *sec, Elf_Rel *rel, ElfW(Sym) *sym,
 	case R_X86_64_PLT32:
 	case R_X86_64_REX_GOTPCRELX:
 		/*
-		 * PC relative relocations don't need to be adjusted unless
-		 * referencing a percpu symbol.
+		 * PC relative relocations don't need to be adjusted.
 		 *
 		 * NB: R_X86_64_PLT32 can be treated as R_X86_64_PC32.
 		 */
-		if (is_percpu_sym(sym, symname))
-			add_reloc(&relocs32neg, offset);
 		break;
 
 	case R_X86_64_PC64:
 		/*
 		 * Only used by jump labels
 		 */
-		if (is_percpu_sym(sym, symname))
-			die("Invalid R_X86_64_PC64 relocation against per-CPU symbol %s\n", symname);
 		break;
 
 	case R_X86_64_32:
 	case R_X86_64_32S:
 	case R_X86_64_64:
-		/*
-		 * References to the percpu area don't need to be adjusted.
-		 */
-		if (is_percpu_sym(sym, symname))
-			break;
-
 		if (shn_abs) {
 			/*
 			 * Whitelisted absolute symbols do not require
@@ -1094,7 +977,6 @@ static void emit_relocs(int as_text, int use_real_mode)
 	/* Order the relocations for more efficient processing */
 	sort_relocs(&relocs32);
 #if ELF_BITS == 64
-	sort_relocs(&relocs32neg);
 	sort_relocs(&relocs64);
 #else
 	sort_relocs(&relocs16);
@@ -1126,13 +1008,6 @@ static void emit_relocs(int as_text, int use_real_mode)
 		/* Now print each relocation */
 		for (i = 0; i < relocs64.count; i++)
 			write_reloc(relocs64.offset[i], stdout);
-
-		/* Print a stop */
-		write_reloc(0, stdout);
-
-		/* Now print each inverse 32-bit relocation */
-		for (i = 0; i < relocs32neg.count; i++)
-			write_reloc(relocs32neg.offset[i], stdout);
 #endif
 
 		/* Print a stop */
@@ -1185,9 +1060,6 @@ void process(FILE *fp, int use_real_mode, int as_text,
 	read_symtabs(fp);
 	read_relocs(fp);
 
-	if (ELF_BITS == 64)
-		percpu_init();
-
 	if (show_absolute_syms) {
 		print_absolute_symbols();
 		return;
-- 
2.47.0


^ permalink raw reply related	[flat|nested] 67+ messages in thread

* [PATCH v5 12/16] x86/percpu/64: Remove INIT_PER_CPU macros
  2024-11-05 15:57 [PATCH v5 00/16] x86-64: Stack protector and percpu improvements Brian Gerst
                   ` (10 preceding siblings ...)
  2024-11-05 15:57 ` [PATCH v5 11/16] x86/boot/64: Remove inverse relocations Brian Gerst
@ 2024-11-05 15:57 ` Brian Gerst
  2024-11-07 13:59   ` Uros Bizjak
  2024-11-05 15:57 ` [PATCH v5 13/16] percpu: Remove PER_CPU_FIRST_SECTION Brian Gerst
                   ` (5 subsequent siblings)
  17 siblings, 1 reply; 67+ messages in thread
From: Brian Gerst @ 2024-11-05 15:57 UTC (permalink / raw)
  To: linux-kernel, x86
  Cc: Ingo Molnar, H . Peter Anvin, Thomas Gleixner, Borislav Petkov,
	Ard Biesheuvel, Uros Bizjak, Brian Gerst

Now that the load and link addresses of percpu variables are the same,
these macros are no longer necessary.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
---
 arch/x86/include/asm/desc.h   |  1 -
 arch/x86/include/asm/percpu.h | 22 ----------------------
 arch/x86/kernel/head64.c      |  2 +-
 arch/x86/kernel/irq_64.c      |  1 -
 arch/x86/kernel/vmlinux.lds.S |  7 -------
 arch/x86/tools/relocs.c       |  1 -
 6 files changed, 1 insertion(+), 33 deletions(-)

diff --git a/arch/x86/include/asm/desc.h b/arch/x86/include/asm/desc.h
index 62dc9f59ea76..ec95fe44fa3a 100644
--- a/arch/x86/include/asm/desc.h
+++ b/arch/x86/include/asm/desc.h
@@ -46,7 +46,6 @@ struct gdt_page {
 } __attribute__((aligned(PAGE_SIZE)));
 
 DECLARE_PER_CPU_PAGE_ALIGNED(struct gdt_page, gdt_page);
-DECLARE_INIT_PER_CPU(gdt_page);
 
 /* Provide the original GDT */
 static inline struct desc_struct *get_cpu_gdt_rw(unsigned int cpu)
diff --git a/arch/x86/include/asm/percpu.h b/arch/x86/include/asm/percpu.h
index c55a79d5feae..1ded1207528d 100644
--- a/arch/x86/include/asm/percpu.h
+++ b/arch/x86/include/asm/percpu.h
@@ -20,12 +20,6 @@
 
 #define PER_CPU_VAR(var)	__percpu(var)__percpu_rel
 
-#ifdef CONFIG_X86_64_SMP
-# define INIT_PER_CPU_VAR(var)  init_per_cpu__##var
-#else
-# define INIT_PER_CPU_VAR(var)  var
-#endif
-
 #else /* !__ASSEMBLY__: */
 
 #include <linux/build_bug.h>
@@ -97,22 +91,6 @@
 #define __percpu_arg(x)		__percpu_prefix "%" #x
 #define __force_percpu_arg(x)	__force_percpu_prefix "%" #x
 
-/*
- * Initialized pointers to per-CPU variables needed for the boot
- * processor need to use these macros to get the proper address
- * offset from __per_cpu_load on SMP.
- *
- * There also must be an entry in vmlinux_64.lds.S
- */
-#define DECLARE_INIT_PER_CPU(var) \
-       extern typeof(var) init_per_cpu_var(var)
-
-#ifdef CONFIG_X86_64_SMP
-# define init_per_cpu_var(var)  init_per_cpu__##var
-#else
-# define init_per_cpu_var(var)  var
-#endif
-
 /*
  * For arch-specific code, we can use direct single-insn ops (they
  * don't give an lvalue though).
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index 4b9d4557fc94..d4398261ad81 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -559,7 +559,7 @@ void early_setup_idt(void)
  */
 void __head startup_64_setup_gdt_idt(void)
 {
-	struct desc_struct *gdt = (void *)(__force unsigned long)init_per_cpu_var(gdt_page.gdt);
+	struct desc_struct *gdt = (void *)(__force unsigned long)gdt_page.gdt;
 	void *handler = NULL;
 
 	struct desc_ptr startup_gdt_descr = {
diff --git a/arch/x86/kernel/irq_64.c b/arch/x86/kernel/irq_64.c
index ade0043ce56e..56bdeecd8ee0 100644
--- a/arch/x86/kernel/irq_64.c
+++ b/arch/x86/kernel/irq_64.c
@@ -27,7 +27,6 @@
 #include <asm/apic.h>
 
 DEFINE_PER_CPU_PAGE_ALIGNED(struct irq_stack, irq_stack_backing_store) __visible;
-DECLARE_INIT_PER_CPU(irq_stack_backing_store);
 
 #ifdef CONFIG_VMAP_STACK
 /*
diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index 859ff7c0dc02..fd1ecb1dbc1d 100644
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -450,13 +450,6 @@ SECTIONS
 PROVIDE(__ref_stack_chk_guard = __stack_chk_guard);
 
 #ifdef CONFIG_X86_64
-/*
- * Per-cpu symbols which need to be offset from __per_cpu_load
- * for the boot processor.
- */
-#define INIT_PER_CPU(x) init_per_cpu__##x = ABSOLUTE(x)
-INIT_PER_CPU(gdt_page);
-INIT_PER_CPU(irq_stack_backing_store);
 
 #ifdef CONFIG_MITIGATION_UNRET_ENTRY
 . = ASSERT((retbleed_return_thunk & 0x3f) == 0, "retbleed_return_thunk not cacheline-aligned");
diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c
index 8d9e82748615..c3124aac7ab3 100644
--- a/arch/x86/tools/relocs.c
+++ b/arch/x86/tools/relocs.c
@@ -89,7 +89,6 @@ static const char * const	sym_regex_kernel[S_NSYMTYPES] = {
 	"__initramfs_start|"
 	"(jiffies|jiffies_64)|"
 #if ELF_BITS == 64
-	"init_per_cpu__.*|"
 	"__end_rodata_hpage_align|"
 #endif
 	"_end)$"
-- 
2.47.0


^ permalink raw reply related	[flat|nested] 67+ messages in thread

* Re: [PATCH v5 12/16] x86/percpu/64: Remove INIT_PER_CPU macros
  2024-11-05 15:57 ` [PATCH v5 12/16] x86/percpu/64: Remove INIT_PER_CPU macros Brian Gerst
@ 2024-11-07 13:59   ` Uros Bizjak
  0 siblings, 0 replies; 67+ messages in thread
From: Uros Bizjak @ 2024-11-07 13:59 UTC (permalink / raw)
  To: Brian Gerst
  Cc: linux-kernel, x86, Ingo Molnar, H . Peter Anvin, Thomas Gleixner,
	Borislav Petkov, Ard Biesheuvel

On Tue, Nov 5, 2024 at 4:58 PM Brian Gerst <brgerst@gmail.com> wrote:
>
> Now that the load and link addresses of percpu variables are the same,
> these macros are no longer necessary.
>
> Signed-off-by: Brian Gerst <brgerst@gmail.com>

Reviewed-by: Uros Bizjak <ubizjak@gmail.com>

> ---
>  arch/x86/include/asm/desc.h   |  1 -
>  arch/x86/include/asm/percpu.h | 22 ----------------------
>  arch/x86/kernel/head64.c      |  2 +-
>  arch/x86/kernel/irq_64.c      |  1 -
>  arch/x86/kernel/vmlinux.lds.S |  7 -------
>  arch/x86/tools/relocs.c       |  1 -
>  6 files changed, 1 insertion(+), 33 deletions(-)
>
> diff --git a/arch/x86/include/asm/desc.h b/arch/x86/include/asm/desc.h
> index 62dc9f59ea76..ec95fe44fa3a 100644
> --- a/arch/x86/include/asm/desc.h
> +++ b/arch/x86/include/asm/desc.h
> @@ -46,7 +46,6 @@ struct gdt_page {
>  } __attribute__((aligned(PAGE_SIZE)));
>
>  DECLARE_PER_CPU_PAGE_ALIGNED(struct gdt_page, gdt_page);
> -DECLARE_INIT_PER_CPU(gdt_page);
>
>  /* Provide the original GDT */
>  static inline struct desc_struct *get_cpu_gdt_rw(unsigned int cpu)
> diff --git a/arch/x86/include/asm/percpu.h b/arch/x86/include/asm/percpu.h
> index c55a79d5feae..1ded1207528d 100644
> --- a/arch/x86/include/asm/percpu.h
> +++ b/arch/x86/include/asm/percpu.h
> @@ -20,12 +20,6 @@
>
>  #define PER_CPU_VAR(var)       __percpu(var)__percpu_rel
>
> -#ifdef CONFIG_X86_64_SMP
> -# define INIT_PER_CPU_VAR(var)  init_per_cpu__##var
> -#else
> -# define INIT_PER_CPU_VAR(var)  var
> -#endif
> -
>  #else /* !__ASSEMBLY__: */
>
>  #include <linux/build_bug.h>
> @@ -97,22 +91,6 @@
>  #define __percpu_arg(x)                __percpu_prefix "%" #x
>  #define __force_percpu_arg(x)  __force_percpu_prefix "%" #x
>
> -/*
> - * Initialized pointers to per-CPU variables needed for the boot
> - * processor need to use these macros to get the proper address
> - * offset from __per_cpu_load on SMP.
> - *
> - * There also must be an entry in vmlinux_64.lds.S
> - */
> -#define DECLARE_INIT_PER_CPU(var) \
> -       extern typeof(var) init_per_cpu_var(var)
> -
> -#ifdef CONFIG_X86_64_SMP
> -# define init_per_cpu_var(var)  init_per_cpu__##var
> -#else
> -# define init_per_cpu_var(var)  var
> -#endif
> -
>  /*
>   * For arch-specific code, we can use direct single-insn ops (they
>   * don't give an lvalue though).
> diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
> index 4b9d4557fc94..d4398261ad81 100644
> --- a/arch/x86/kernel/head64.c
> +++ b/arch/x86/kernel/head64.c
> @@ -559,7 +559,7 @@ void early_setup_idt(void)
>   */
>  void __head startup_64_setup_gdt_idt(void)
>  {
> -       struct desc_struct *gdt = (void *)(__force unsigned long)init_per_cpu_var(gdt_page.gdt);
> +       struct desc_struct *gdt = (void *)(__force unsigned long)gdt_page.gdt;
>         void *handler = NULL;
>
>         struct desc_ptr startup_gdt_descr = {
> diff --git a/arch/x86/kernel/irq_64.c b/arch/x86/kernel/irq_64.c
> index ade0043ce56e..56bdeecd8ee0 100644
> --- a/arch/x86/kernel/irq_64.c
> +++ b/arch/x86/kernel/irq_64.c
> @@ -27,7 +27,6 @@
>  #include <asm/apic.h>
>
>  DEFINE_PER_CPU_PAGE_ALIGNED(struct irq_stack, irq_stack_backing_store) __visible;
> -DECLARE_INIT_PER_CPU(irq_stack_backing_store);
>
>  #ifdef CONFIG_VMAP_STACK
>  /*
> diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
> index 859ff7c0dc02..fd1ecb1dbc1d 100644
> --- a/arch/x86/kernel/vmlinux.lds.S
> +++ b/arch/x86/kernel/vmlinux.lds.S
> @@ -450,13 +450,6 @@ SECTIONS
>  PROVIDE(__ref_stack_chk_guard = __stack_chk_guard);
>
>  #ifdef CONFIG_X86_64
> -/*
> - * Per-cpu symbols which need to be offset from __per_cpu_load
> - * for the boot processor.
> - */
> -#define INIT_PER_CPU(x) init_per_cpu__##x = ABSOLUTE(x)
> -INIT_PER_CPU(gdt_page);
> -INIT_PER_CPU(irq_stack_backing_store);
>
>  #ifdef CONFIG_MITIGATION_UNRET_ENTRY
>  . = ASSERT((retbleed_return_thunk & 0x3f) == 0, "retbleed_return_thunk not cacheline-aligned");
> diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c
> index 8d9e82748615..c3124aac7ab3 100644
> --- a/arch/x86/tools/relocs.c
> +++ b/arch/x86/tools/relocs.c
> @@ -89,7 +89,6 @@ static const char * const     sym_regex_kernel[S_NSYMTYPES] = {
>         "__initramfs_start|"
>         "(jiffies|jiffies_64)|"
>  #if ELF_BITS == 64
> -       "init_per_cpu__.*|"
>         "__end_rodata_hpage_align|"
>  #endif
>         "_end)$"
> --
> 2.47.0
>

^ permalink raw reply	[flat|nested] 67+ messages in thread

* [PATCH v5 13/16] percpu: Remove PER_CPU_FIRST_SECTION
  2024-11-05 15:57 [PATCH v5 00/16] x86-64: Stack protector and percpu improvements Brian Gerst
                   ` (11 preceding siblings ...)
  2024-11-05 15:57 ` [PATCH v5 12/16] x86/percpu/64: Remove INIT_PER_CPU macros Brian Gerst
@ 2024-11-05 15:57 ` Brian Gerst
  2024-11-05 15:57 ` [PATCH v5 14/16] percpu: Remove PERCPU_VADDR() Brian Gerst
                   ` (4 subsequent siblings)
  17 siblings, 0 replies; 67+ messages in thread
From: Brian Gerst @ 2024-11-05 15:57 UTC (permalink / raw)
  To: linux-kernel, x86
  Cc: Ingo Molnar, H . Peter Anvin, Thomas Gleixner, Borislav Petkov,
	Ard Biesheuvel, Uros Bizjak, Brian Gerst

x86-64 was the last user.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
---
 include/asm-generic/vmlinux.lds.h |  1 -
 include/linux/percpu-defs.h       | 12 ------------
 2 files changed, 13 deletions(-)

diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index eeadbaeccf88..70830a742095 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -1034,7 +1034,6 @@
  */
 #define PERCPU_INPUT(cacheline)						\
 	__per_cpu_start = .;						\
-	*(.data..percpu..first)						\
 	. = ALIGN(PAGE_SIZE);						\
 	*(.data..percpu..page_aligned)					\
 	. = ALIGN(cacheline);						\
diff --git a/include/linux/percpu-defs.h b/include/linux/percpu-defs.h
index 8efce7414fad..a28fa362d685 100644
--- a/include/linux/percpu-defs.h
+++ b/include/linux/percpu-defs.h
@@ -26,13 +26,11 @@
 #define PER_CPU_SHARED_ALIGNED_SECTION "..shared_aligned"
 #define PER_CPU_ALIGNED_SECTION "..shared_aligned"
 #endif
-#define PER_CPU_FIRST_SECTION "..first"
 
 #else
 
 #define PER_CPU_SHARED_ALIGNED_SECTION ""
 #define PER_CPU_ALIGNED_SECTION "..shared_aligned"
-#define PER_CPU_FIRST_SECTION ""
 
 #endif
 
@@ -114,16 +112,6 @@
 #define DEFINE_PER_CPU(type, name)					\
 	DEFINE_PER_CPU_SECTION(type, name, "")
 
-/*
- * Declaration/definition used for per-CPU variables that must come first in
- * the set of variables.
- */
-#define DECLARE_PER_CPU_FIRST(type, name)				\
-	DECLARE_PER_CPU_SECTION(type, name, PER_CPU_FIRST_SECTION)
-
-#define DEFINE_PER_CPU_FIRST(type, name)				\
-	DEFINE_PER_CPU_SECTION(type, name, PER_CPU_FIRST_SECTION)
-
 /*
  * Declaration/definition used for per-CPU variables that must be cacheline
  * aligned under SMP conditions so that, whilst a particular instance of the
-- 
2.47.0


^ permalink raw reply related	[flat|nested] 67+ messages in thread

* [PATCH v5 14/16] percpu: Remove PERCPU_VADDR()
  2024-11-05 15:57 [PATCH v5 00/16] x86-64: Stack protector and percpu improvements Brian Gerst
                   ` (12 preceding siblings ...)
  2024-11-05 15:57 ` [PATCH v5 13/16] percpu: Remove PER_CPU_FIRST_SECTION Brian Gerst
@ 2024-11-05 15:57 ` Brian Gerst
  2024-11-05 15:58 ` [PATCH v5 15/16] percpu: Remove __per_cpu_load Brian Gerst
                   ` (3 subsequent siblings)
  17 siblings, 0 replies; 67+ messages in thread
From: Brian Gerst @ 2024-11-05 15:57 UTC (permalink / raw)
  To: linux-kernel, x86
  Cc: Ingo Molnar, H . Peter Anvin, Thomas Gleixner, Borislav Petkov,
	Ard Biesheuvel, Uros Bizjak, Brian Gerst

x86-64 was the last user.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
---
 include/asm-generic/vmlinux.lds.h | 36 +------------------------------
 1 file changed, 1 insertion(+), 35 deletions(-)

diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index 70830a742095..f53915f4e777 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -1045,47 +1045,13 @@
 	__per_cpu_end = .;
 
 /**
- * PERCPU_VADDR - define output section for percpu area
+ * PERCPU_SECTION - define output section for percpu area
  * @cacheline: cacheline size
- * @vaddr: explicit base address (optional)
- * @phdr: destination PHDR (optional)
  *
  * Macro which expands to output section for percpu area.
  *
  * @cacheline is used to align subsections to avoid false cacheline
  * sharing between subsections for different purposes.
- *
- * If @vaddr is not blank, it specifies explicit base address and all
- * percpu symbols will be offset from the given address.  If blank,
- * @vaddr always equals @laddr + LOAD_OFFSET.
- *
- * @phdr defines the output PHDR to use if not blank.  Be warned that
- * output PHDR is sticky.  If @phdr is specified, the next output
- * section in the linker script will go there too.  @phdr should have
- * a leading colon.
- *
- * Note that this macros defines __per_cpu_load as an absolute symbol.
- * If there is no need to put the percpu section at a predetermined
- * address, use PERCPU_SECTION.
- */
-#define PERCPU_VADDR(cacheline, vaddr, phdr)				\
-	__per_cpu_load = .;						\
-	.data..percpu vaddr : AT(__per_cpu_load - LOAD_OFFSET) {	\
-		PERCPU_INPUT(cacheline)					\
-	} phdr								\
-	. = __per_cpu_load + SIZEOF(.data..percpu);
-
-/**
- * PERCPU_SECTION - define output section for percpu area, simple version
- * @cacheline: cacheline size
- *
- * Align to PAGE_SIZE and outputs output section for percpu area.  This
- * macro doesn't manipulate @vaddr or @phdr and __per_cpu_load and
- * __per_cpu_start will be identical.
- *
- * This macro is equivalent to ALIGN(PAGE_SIZE); PERCPU_VADDR(@cacheline,,)
- * except that __per_cpu_load is defined as a relative symbol against
- * .data..percpu which is required for relocatable x86_32 configuration.
  */
 #define PERCPU_SECTION(cacheline)					\
 	. = ALIGN(PAGE_SIZE);						\
-- 
2.47.0


^ permalink raw reply related	[flat|nested] 67+ messages in thread

* [PATCH v5 15/16] percpu: Remove __per_cpu_load
  2024-11-05 15:57 [PATCH v5 00/16] x86-64: Stack protector and percpu improvements Brian Gerst
                   ` (13 preceding siblings ...)
  2024-11-05 15:57 ` [PATCH v5 14/16] percpu: Remove PERCPU_VADDR() Brian Gerst
@ 2024-11-05 15:58 ` Brian Gerst
  2024-11-05 15:58 ` [PATCH v5 16/16] kallsyms: Remove KALLSYMS_ABSOLUTE_PERCPU Brian Gerst
                   ` (2 subsequent siblings)
  17 siblings, 0 replies; 67+ messages in thread
From: Brian Gerst @ 2024-11-05 15:58 UTC (permalink / raw)
  To: linux-kernel, x86
  Cc: Ingo Molnar, H . Peter Anvin, Thomas Gleixner, Borislav Petkov,
	Ard Biesheuvel, Uros Bizjak, Brian Gerst

__per_cpu_load is now always equal to __per_cpu_start.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
---
 include/asm-generic/sections.h    | 2 +-
 include/asm-generic/vmlinux.lds.h | 1 -
 mm/percpu.c                       | 4 ++--
 3 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/include/asm-generic/sections.h b/include/asm-generic/sections.h
index c768de6f19a9..0755bc39b0d8 100644
--- a/include/asm-generic/sections.h
+++ b/include/asm-generic/sections.h
@@ -39,7 +39,7 @@ extern char __init_begin[], __init_end[];
 extern char _sinittext[], _einittext[];
 extern char __start_ro_after_init[], __end_ro_after_init[];
 extern char _end[];
-extern char __per_cpu_load[], __per_cpu_start[], __per_cpu_end[];
+extern char __per_cpu_start[], __per_cpu_end[];
 extern char __kprobes_text_start[], __kprobes_text_end[];
 extern char __entry_text_start[], __entry_text_end[];
 extern char __start_rodata[], __end_rodata[];
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index f53915f4e777..889f5885e346 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -1056,7 +1056,6 @@
 #define PERCPU_SECTION(cacheline)					\
 	. = ALIGN(PAGE_SIZE);						\
 	.data..percpu	: AT(ADDR(.data..percpu) - LOAD_OFFSET) {	\
-		__per_cpu_load = .;					\
 		PERCPU_INPUT(cacheline)					\
 	}
 
diff --git a/mm/percpu.c b/mm/percpu.c
index da21680ff294..6ed8ba67d1d9 100644
--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -3098,7 +3098,7 @@ int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size,
 				continue;
 			}
 			/* copy and return the unused part */
-			memcpy(ptr, __per_cpu_load, ai->static_size);
+			memcpy(ptr, __per_cpu_start, ai->static_size);
 			pcpu_fc_free(ptr + size_sum, ai->unit_size - size_sum);
 		}
 	}
@@ -3281,7 +3281,7 @@ int __init pcpu_page_first_chunk(size_t reserved_size, pcpu_fc_cpu_to_node_fn_t
 		flush_cache_vmap_early(unit_addr, unit_addr + ai->unit_size);
 
 		/* copy static data */
-		memcpy((void *)unit_addr, __per_cpu_load, ai->static_size);
+		memcpy((void *)unit_addr, __per_cpu_start, ai->static_size);
 	}
 
 	/* we're ready, commit */
-- 
2.47.0


^ permalink raw reply related	[flat|nested] 67+ messages in thread

* [PATCH v5 16/16] kallsyms: Remove KALLSYMS_ABSOLUTE_PERCPU
  2024-11-05 15:57 [PATCH v5 00/16] x86-64: Stack protector and percpu improvements Brian Gerst
                   ` (14 preceding siblings ...)
  2024-11-05 15:58 ` [PATCH v5 15/16] percpu: Remove __per_cpu_load Brian Gerst
@ 2024-11-05 15:58 ` Brian Gerst
  2024-11-09  9:31 ` [PATCH v5 00/16] x86-64: Stack protector and percpu improvements David Laight
  2025-01-04  9:14 ` Ard Biesheuvel
  17 siblings, 0 replies; 67+ messages in thread
From: Brian Gerst @ 2024-11-05 15:58 UTC (permalink / raw)
  To: linux-kernel, x86
  Cc: Ingo Molnar, H . Peter Anvin, Thomas Gleixner, Borislav Petkov,
	Ard Biesheuvel, Uros Bizjak, Brian Gerst

x86-64 was the only user.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
---
 init/Kconfig            |  5 ---
 kernel/kallsyms.c       | 12 ++-----
 scripts/kallsyms.c      | 72 +++++++----------------------------------
 scripts/link-vmlinux.sh |  4 ---
 4 files changed, 14 insertions(+), 79 deletions(-)

diff --git a/init/Kconfig b/init/Kconfig
index b374c0de5cfd..32db844d00d1 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1846,11 +1846,6 @@ config KALLSYMS_ALL
 
 	  Say N unless you really need all symbols, or kernel live patching.
 
-config KALLSYMS_ABSOLUTE_PERCPU
-	bool
-	depends on KALLSYMS
-	default n
-
 # end of the "standard kernel features (expert users)" menu
 
 config ARCH_HAS_MEMBARRIER_CALLBACKS
diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c
index a9a0ca605d4a..4198f30aac3c 100644
--- a/kernel/kallsyms.c
+++ b/kernel/kallsyms.c
@@ -148,16 +148,8 @@ static unsigned int get_symbol_offset(unsigned long pos)
 
 unsigned long kallsyms_sym_address(int idx)
 {
-	/* values are unsigned offsets if --absolute-percpu is not in effect */
-	if (!IS_ENABLED(CONFIG_KALLSYMS_ABSOLUTE_PERCPU))
-		return kallsyms_relative_base + (u32)kallsyms_offsets[idx];
-
-	/* ...otherwise, positive offsets are absolute values */
-	if (kallsyms_offsets[idx] >= 0)
-		return kallsyms_offsets[idx];
-
-	/* ...and negative offsets are relative to kallsyms_relative_base - 1 */
-	return kallsyms_relative_base - 1 - kallsyms_offsets[idx];
+	/* values are unsigned offsets */
+	return kallsyms_relative_base + (u32)kallsyms_offsets[idx];
 }
 
 static unsigned int get_symbol_seq(int index)
diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c
index 03852da3d249..4b0234e4b12f 100644
--- a/scripts/kallsyms.c
+++ b/scripts/kallsyms.c
@@ -5,7 +5,7 @@
  * This software may be used and distributed according to the terms
  * of the GNU General Public License, incorporated herein by reference.
  *
- * Usage: kallsyms [--all-symbols] [--absolute-percpu]  in.map > out.S
+ * Usage: kallsyms [--all-symbols] in.map > out.S
  *
  *      Table compression uses all the unused char codes on the symbols and
  *  maps these to the most used substrings (tokens). For instance, it might
@@ -37,7 +37,6 @@ struct sym_entry {
 	unsigned long long addr;
 	unsigned int len;
 	unsigned int seq;
-	bool percpu_absolute;
 	unsigned char sym[];
 };
 
@@ -55,14 +54,9 @@ static struct addr_range text_ranges[] = {
 #define text_range_text     (&text_ranges[0])
 #define text_range_inittext (&text_ranges[1])
 
-static struct addr_range percpu_range = {
-	"__per_cpu_start", "__per_cpu_end", -1ULL, 0
-};
-
 static struct sym_entry **table;
 static unsigned int table_size, table_cnt;
 static int all_symbols;
-static int absolute_percpu;
 
 static int token_profit[0x10000];
 
@@ -73,7 +67,7 @@ static unsigned char best_table_len[256];
 
 static void usage(void)
 {
-	fprintf(stderr, "Usage: kallsyms [--all-symbols] [--absolute-percpu] in.map > out.S\n");
+	fprintf(stderr, "Usage: kallsyms [--all-symbols] in.map > out.S\n");
 	exit(1);
 }
 
@@ -164,7 +158,6 @@ static struct sym_entry *read_symbol(FILE *in, char **buf, size_t *buf_len)
 		return NULL;
 
 	check_symbol_range(name, addr, text_ranges, ARRAY_SIZE(text_ranges));
-	check_symbol_range(name, addr, &percpu_range, 1);
 
 	/* include the type field in the symbol name, so that it gets
 	 * compressed together */
@@ -175,7 +168,6 @@ static struct sym_entry *read_symbol(FILE *in, char **buf, size_t *buf_len)
 	sym->len = len;
 	sym->sym[0] = type;
 	strcpy(sym_name(sym), name);
-	sym->percpu_absolute = false;
 
 	return sym;
 }
@@ -319,11 +311,6 @@ static int expand_symbol(const unsigned char *data, int len, char *result)
 	return total;
 }
 
-static bool symbol_absolute(const struct sym_entry *s)
-{
-	return s->percpu_absolute;
-}
-
 static int compare_names(const void *a, const void *b)
 {
 	int ret;
@@ -455,22 +442,11 @@ static void write_src(void)
 		 */
 
 		long long offset;
-		bool overflow;
-
-		if (!absolute_percpu) {
-			offset = table[i]->addr - relative_base;
-			overflow = offset < 0 || offset > UINT_MAX;
-		} else if (symbol_absolute(table[i])) {
-			offset = table[i]->addr;
-			overflow = offset < 0 || offset > INT_MAX;
-		} else {
-			offset = relative_base - table[i]->addr - 1;
-			overflow = offset < INT_MIN || offset >= 0;
-		}
-		if (overflow) {
+
+		offset = table[i]->addr - relative_base;
+		if (offset < 0 || offset > UINT_MAX) {
 			fprintf(stderr, "kallsyms failure: "
-				"%s symbol value %#llx out of range in relative mode\n",
-				symbol_absolute(table[i]) ? "absolute" : "relative",
+				"relative symbol value %#llx out of range\n",
 				table[i]->addr);
 			exit(EXIT_FAILURE);
 		}
@@ -725,36 +701,15 @@ static void sort_symbols(void)
 	qsort(table, table_cnt, sizeof(table[0]), compare_symbols);
 }
 
-static void make_percpus_absolute(void)
-{
-	unsigned int i;
-
-	for (i = 0; i < table_cnt; i++)
-		if (symbol_in_range(table[i], &percpu_range, 1)) {
-			/*
-			 * Keep the 'A' override for percpu symbols to
-			 * ensure consistent behavior compared to older
-			 * versions of this tool.
-			 */
-			table[i]->sym[0] = 'A';
-			table[i]->percpu_absolute = true;
-		}
-}
-
 /* find the minimum non-absolute symbol address */
 static void record_relative_base(void)
 {
-	unsigned int i;
-
-	for (i = 0; i < table_cnt; i++)
-		if (!symbol_absolute(table[i])) {
-			/*
-			 * The table is sorted by address.
-			 * Take the first non-absolute symbol value.
-			 */
-			relative_base = table[i]->addr;
-			return;
-		}
+	/*
+	 * The table is sorted by address.
+	 * Take the first symbol value.
+	 */
+	if (table_cnt)
+		relative_base = table[0]->addr;
 }
 
 int main(int argc, char **argv)
@@ -762,7 +717,6 @@ int main(int argc, char **argv)
 	while (1) {
 		static const struct option long_options[] = {
 			{"all-symbols",     no_argument, &all_symbols,     1},
-			{"absolute-percpu", no_argument, &absolute_percpu, 1},
 			{},
 		};
 
@@ -779,8 +733,6 @@ int main(int argc, char **argv)
 
 	read_map(argv[optind]);
 	shrink_table();
-	if (absolute_percpu)
-		make_percpus_absolute();
 	sort_symbols();
 	record_relative_base();
 	optimize_token_table();
diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
index a9b3f34a78d2..df5f3fbb46f3 100755
--- a/scripts/link-vmlinux.sh
+++ b/scripts/link-vmlinux.sh
@@ -140,10 +140,6 @@ kallsyms()
 		kallsymopt="${kallsymopt} --all-symbols"
 	fi
 
-	if is_enabled CONFIG_KALLSYMS_ABSOLUTE_PERCPU; then
-		kallsymopt="${kallsymopt} --absolute-percpu"
-	fi
-
 	info KSYMS "${2}.S"
 	scripts/kallsyms ${kallsymopt} "${1}" > "${2}.S"
 
-- 
2.47.0


^ permalink raw reply related	[flat|nested] 67+ messages in thread

* RE: [PATCH v5 00/16] x86-64: Stack protector and percpu improvements
  2024-11-05 15:57 [PATCH v5 00/16] x86-64: Stack protector and percpu improvements Brian Gerst
                   ` (15 preceding siblings ...)
  2024-11-05 15:58 ` [PATCH v5 16/16] kallsyms: Remove KALLSYMS_ABSOLUTE_PERCPU Brian Gerst
@ 2024-11-09  9:31 ` David Laight
  2024-11-09 15:11   ` Brian Gerst
  2025-01-04  9:14 ` Ard Biesheuvel
  17 siblings, 1 reply; 67+ messages in thread
From: David Laight @ 2024-11-09  9:31 UTC (permalink / raw)
  To: 'Brian Gerst', linux-kernel@vger.kernel.org,
	x86@kernel.org
  Cc: Ingo Molnar, H . Peter Anvin, Thomas Gleixner, Borislav Petkov,
	Ard Biesheuvel, Uros Bizjak

From: Brian Gerst
> Sent: 05 November 2024 15:58
> 
> Currently, x86-64 uses an unusual percpu layout, where the percpu section
> is linked at absolute address 0.  The reason behind this is that older GCC
> versions placed the stack protector (if enabled) at a fixed offset from the
> GS segment base.  Since the GS segement is also used for percpu variables,
> this forced the current layout.
> 
> GCC since version 8.1 supports a configurable location for the stack
> protector value, which allows removal of the restriction on how the percpu
> section is linked.  This allows the percpu section to be linked normally,
> like other architectures.  In turn, this allows removal of code that was
> needed to support the zero-based percpu section.
> 
> v5:
> - Added two patches from Ard Biesheuvel to make stack protector work
>   properly when compiling with clang.
> - Raise minimum GCC version to 8.1 for x86.
> - Drop objtool conversion code.

Is there any actual need to raise the GCC level?
Isn't it enough just to disable stack protection with older compilers?
The percpu layout can then always be the new (sane) one.

Is there even a selectable CONFIG_STACK_PROTECTOR?
Can than depend on gcc >= 8.1 for x86-64?

I've a slight vested interest in that the system I test kernels on
has gcc 7.5.0 installed :-)

	David

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)


^ permalink raw reply	[flat|nested] 67+ messages in thread

* Re: [PATCH v5 00/16] x86-64: Stack protector and percpu improvements
  2024-11-09  9:31 ` [PATCH v5 00/16] x86-64: Stack protector and percpu improvements David Laight
@ 2024-11-09 15:11   ` Brian Gerst
  2024-11-09 21:27     ` David Laight
  0 siblings, 1 reply; 67+ messages in thread
From: Brian Gerst @ 2024-11-09 15:11 UTC (permalink / raw)
  To: David Laight
  Cc: linux-kernel@vger.kernel.org, x86@kernel.org, Ingo Molnar,
	H . Peter Anvin, Thomas Gleixner, Borislav Petkov, Ard Biesheuvel,
	Uros Bizjak

On Sat, Nov 9, 2024 at 4:31 AM David Laight <David.Laight@aculab.com> wrote:
>
> From: Brian Gerst
> > Sent: 05 November 2024 15:58
> >
> > Currently, x86-64 uses an unusual percpu layout, where the percpu section
> > is linked at absolute address 0.  The reason behind this is that older GCC
> > versions placed the stack protector (if enabled) at a fixed offset from the
> > GS segment base.  Since the GS segement is also used for percpu variables,
> > this forced the current layout.
> >
> > GCC since version 8.1 supports a configurable location for the stack
> > protector value, which allows removal of the restriction on how the percpu
> > section is linked.  This allows the percpu section to be linked normally,
> > like other architectures.  In turn, this allows removal of code that was
> > needed to support the zero-based percpu section.
> >
> > v5:
> > - Added two patches from Ard Biesheuvel to make stack protector work
> >   properly when compiling with clang.
> > - Raise minimum GCC version to 8.1 for x86.
> > - Drop objtool conversion code.
>
> Is there any actual need to raise the GCC level?
> Isn't it enough just to disable stack protection with older compilers?
> The percpu layout can then always be the new (sane) one.

Earlier versions of this series did make stack protector support
conditional on newer compilers.  That got rejected.  I then added
objtool support to convert the code old compilers produced.  That also
got rejected.  I guess I can't please everyone.

> Is there even a selectable CONFIG_STACK_PROTECTOR?
> Can than depend on gcc >= 8.1 for x86-64?

Yes, stack protector support is optional, but practically all distro
kernels enable it.

> I've a slight vested interest in that the system I test kernels on
> has gcc 7.5.0 installed :-)

What distro is on that system?  Is it still actively supported?

Brian Gerst

^ permalink raw reply	[flat|nested] 67+ messages in thread

* RE: [PATCH v5 00/16] x86-64: Stack protector and percpu improvements
  2024-11-09 15:11   ` Brian Gerst
@ 2024-11-09 21:27     ` David Laight
  0 siblings, 0 replies; 67+ messages in thread
From: David Laight @ 2024-11-09 21:27 UTC (permalink / raw)
  To: 'Brian Gerst'
  Cc: linux-kernel@vger.kernel.org, x86@kernel.org, Ingo Molnar,
	H . Peter Anvin, Thomas Gleixner, Borislav Petkov, Ard Biesheuvel,
	Uros Bizjak

From: Brian Gerst
> Sent: 09 November 2024 15:11
> 
> On Sat, Nov 9, 2024 at 4:31 AM David Laight <David.Laight@aculab.com> wrote:
> >
> > From: Brian Gerst
> > > Sent: 05 November 2024 15:58
> > >
> > > Currently, x86-64 uses an unusual percpu layout, where the percpu section
> > > is linked at absolute address 0.  The reason behind this is that older GCC
> > > versions placed the stack protector (if enabled) at a fixed offset from the
> > > GS segment base.  Since the GS segement is also used for percpu variables,
> > > this forced the current layout.
> > >
> > > GCC since version 8.1 supports a configurable location for the stack
> > > protector value, which allows removal of the restriction on how the percpu
> > > section is linked.  This allows the percpu section to be linked normally,
> > > like other architectures.  In turn, this allows removal of code that was
> > > needed to support the zero-based percpu section.
> > >
> > > v5:
> > > - Added two patches from Ard Biesheuvel to make stack protector work
> > >   properly when compiling with clang.
> > > - Raise minimum GCC version to 8.1 for x86.
> > > - Drop objtool conversion code.
> >
> > Is there any actual need to raise the GCC level?
> > Isn't it enough just to disable stack protection with older compilers?
> > The percpu layout can then always be the new (sane) one.
> 
> Earlier versions of this series did make stack protector support
> conditional on newer compilers.  That got rejected.  I then added
> objtool support to convert the code old compilers produced.  That also
> got rejected.  I guess I can't please everyone.

I certainly wouldn't have bothered hacking objtool.

> > Is there even a selectable CONFIG_STACK_PROTECTOR?
> > Can than depend on gcc >= 8.1 for x86-64?
> 
> Yes, stack protector support is optional, but practically all distro
> kernels enable it.

They include all sorts of stuff that slows things down :-)
But I'd rather be able to build and test kernels than have the stack protector.

> > I've a slight vested interest in that the system I test kernels on
> > has gcc 7.5.0 installed :-)
> 
> What distro is on that system?  Is it still actively supported?

The system in running Ubuntu 18.04 LTS - and still receives updates.
I do run locally build kernels on it, but I could just be building kernels.
Seems a shame to force an update for something I can just deselect.

For reference RHEL7 is still supported but has a 4.8.5 compiler.
So it is a long time since that has self-hosted kernels.
We build software for release on Centos-7 as an easy way to get an old glibc (etc),
although buildroot/busybox (x86-64) 'distribution' has to use a newer
compiler - the grub build fails well before you get to a kernel!

	David

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)

^ permalink raw reply	[flat|nested] 67+ messages in thread

* Re: [PATCH v5 00/16] x86-64: Stack protector and percpu improvements
  2024-11-05 15:57 [PATCH v5 00/16] x86-64: Stack protector and percpu improvements Brian Gerst
                   ` (16 preceding siblings ...)
  2024-11-09  9:31 ` [PATCH v5 00/16] x86-64: Stack protector and percpu improvements David Laight
@ 2025-01-04  9:14 ` Ard Biesheuvel
  17 siblings, 0 replies; 67+ messages in thread
From: Ard Biesheuvel @ 2025-01-04  9:14 UTC (permalink / raw)
  To: Brian Gerst
  Cc: linux-kernel, x86, Ingo Molnar, H . Peter Anvin, Thomas Gleixner,
	Borislav Petkov, Uros Bizjak

On Tue, 5 Nov 2024 at 16:58, Brian Gerst <brgerst@gmail.com> wrote:
>
> Currently, x86-64 uses an unusual percpu layout, where the percpu section
> is linked at absolute address 0.  The reason behind this is that older GCC
> versions placed the stack protector (if enabled) at a fixed offset from the
> GS segment base.  Since the GS segement is also used for percpu variables,
> this forced the current layout.
>
> GCC since version 8.1 supports a configurable location for the stack
> protector value, which allows removal of the restriction on how the percpu
> section is linked.  This allows the percpu section to be linked normally,
> like other architectures.  In turn, this allows removal of code that was
> needed to support the zero-based percpu section.
>
> v5:
> - Added two patches from Ard Biesheuvel to make stack protector work
>   properly when compiling with clang.
> - Raise minimum GCC version to 8.1 for x86.
> - Drop objtool conversion code.
>
> Ard Biesheuvel (2):
>   x86/stackprotector: Work around strict Clang TLS symbol requirements
>   x86/module: Deal with GOT based stack cookie load on Clang < 17
>
> Brian Gerst (14):
>   x86: Raise minimum GCC version to 8.1
>   x86/stackprotector: Remove stack protector test scripts
>   x86/boot: Disable stack protector for early boot code
>   x86/pvh: Use fixed_percpu_data for early boot GSBASE
>   x86/relocs: Handle R_X86_64_REX_GOTPCRELX relocations
>   x86/stackprotector/64: Convert to normal percpu variable
>   x86/percpu/64: Use relative percpu offsets
>   x86/percpu/64: Remove fixed_percpu_data
>   x86/boot/64: Remove inverse relocations
>   x86/percpu/64: Remove INIT_PER_CPU macros
>   percpu: Remove PER_CPU_FIRST_SECTION
>   percpu: Remove PERCPU_VADDR()
>   percpu: Remove __per_cpu_load
>   kallsyms: Remove KALLSYMS_ABSOLUTE_PERCPU
>

For the series,

Reviewed-by: Ard Biesheuvel <ardb@kernel.org>

^ permalink raw reply	[flat|nested] 67+ messages in thread

end of thread, other threads:[~2025-03-12  9:29 UTC | newest]

Thread overview: 67+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2024-11-05 15:57 [PATCH v5 00/16] x86-64: Stack protector and percpu improvements Brian Gerst
2024-11-05 15:57 ` [PATCH v5 01/16] x86/stackprotector: Work around strict Clang TLS symbol requirements Brian Gerst
2024-11-05 19:30   ` Nathan Chancellor
2024-11-08 14:43   ` [tip: x86/urgent] " tip-bot2 for Ard Biesheuvel
2024-12-06 11:51   ` [PATCH v5 01/16] " Oleg Nesterov
2024-12-06 14:09     ` Brian Gerst
2024-12-06 14:28       ` Oleg Nesterov
2024-12-06 12:32   ` [PATCH] x86/stackprotector: fix build failure with CONFIG_STACKPROTECTOR=n Oleg Nesterov
2024-12-06 13:17     ` Ard Biesheuvel
2024-12-06 14:21       ` Oleg Nesterov
2024-12-06 14:37         ` Ard Biesheuvel
2024-12-06 15:12           ` Brian Gerst
2024-12-06 15:17             ` Ard Biesheuvel
2025-03-10 21:44               ` Borislav Petkov
2025-03-10 22:19                 ` Ard Biesheuvel
2025-03-11 10:23                   ` Borislav Petkov
2025-03-11 10:37                     ` Ard Biesheuvel
2025-03-11 11:21                       ` Borislav Petkov
2025-03-11 13:13                         ` Borislav Petkov
2025-03-11 14:37                           ` Oleg Nesterov
2025-03-11 17:46                             ` Borislav Petkov
2025-03-11 18:10                               ` Oleg Nesterov
2025-03-11 19:01                                 ` Borislav Petkov
2025-03-11 19:24                                   ` Oleg Nesterov
2025-03-11 21:27                                     ` Brian Gerst
2025-03-11 21:42                                       ` Oleg Nesterov
2025-03-11 21:47                                         ` Brian Gerst
2025-03-12  9:28                           ` Borislav Petkov
2024-11-05 15:57 ` [PATCH v5 02/16] x86: Raise minimum GCC version to 8.1 Brian Gerst
2024-12-05 11:44   ` Ard Biesheuvel
2024-12-05 16:05     ` Brian Gerst
2025-01-14 16:25   ` Borislav Petkov
2024-11-05 15:57 ` [PATCH v5 03/16] x86/stackprotector: Remove stack protector test scripts Brian Gerst
2024-11-07 13:19   ` Uros Bizjak
2024-11-05 15:57 ` [PATCH v5 04/16] x86/boot: Disable stack protector for early boot code Brian Gerst
2024-11-05 15:57 ` [PATCH v5 05/16] x86/pvh: Use fixed_percpu_data for early boot GSBASE Brian Gerst
2024-11-07 14:30   ` Uros Bizjak
2024-11-05 15:57 ` [PATCH v5 06/16] x86/relocs: Handle R_X86_64_REX_GOTPCRELX relocations Brian Gerst
2024-11-07 11:20   ` Uros Bizjak
2024-11-07 11:27     ` Brian Gerst
2024-11-07 11:31       ` Uros Bizjak
2024-11-05 15:57 ` [PATCH v5 07/16] x86/module: Deal with GOT based stack cookie load on Clang < 17 Brian Gerst
2024-11-09  9:36   ` David Laight
2024-11-05 15:57 ` [PATCH v5 08/16] x86/stackprotector/64: Convert to normal percpu variable Brian Gerst
2024-11-07 13:29   ` Uros Bizjak
2025-02-15 14:27   ` Borislav Petkov
2025-02-15 17:38     ` Brian Gerst
2025-02-15 21:18       ` Borislav Petkov
2025-02-15 22:10         ` Brian Gerst
2025-02-16  8:33           ` Borislav Petkov
2024-11-05 15:57 ` [PATCH v5 09/16] x86/percpu/64: Use relative percpu offsets Brian Gerst
2024-11-07 11:28   ` Uros Bizjak
2024-11-07 12:05     ` Brian Gerst
2024-11-07 13:34       ` Uros Bizjak
2024-11-05 15:57 ` [PATCH v5 10/16] x86/percpu/64: Remove fixed_percpu_data Brian Gerst
2024-11-07 13:32   ` Uros Bizjak
2024-11-05 15:57 ` [PATCH v5 11/16] x86/boot/64: Remove inverse relocations Brian Gerst
2024-11-05 15:57 ` [PATCH v5 12/16] x86/percpu/64: Remove INIT_PER_CPU macros Brian Gerst
2024-11-07 13:59   ` Uros Bizjak
2024-11-05 15:57 ` [PATCH v5 13/16] percpu: Remove PER_CPU_FIRST_SECTION Brian Gerst
2024-11-05 15:57 ` [PATCH v5 14/16] percpu: Remove PERCPU_VADDR() Brian Gerst
2024-11-05 15:58 ` [PATCH v5 15/16] percpu: Remove __per_cpu_load Brian Gerst
2024-11-05 15:58 ` [PATCH v5 16/16] kallsyms: Remove KALLSYMS_ABSOLUTE_PERCPU Brian Gerst
2024-11-09  9:31 ` [PATCH v5 00/16] x86-64: Stack protector and percpu improvements David Laight
2024-11-09 15:11   ` Brian Gerst
2024-11-09 21:27     ` David Laight
2025-01-04  9:14 ` Ard Biesheuvel

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