* [PATCH RFC 0/4] stackleak: Support Clang stack depth tracking
@ 2025-05-02 19:01 Kees Cook
2025-05-02 19:01 ` [PATCH RFC 1/4] stackleak: Rename CONFIG_GCC_PLUGIN_STACKLEAK to CONFIG_STACKLEAK Kees Cook
` (3 more replies)
0 siblings, 4 replies; 5+ messages in thread
From: Kees Cook @ 2025-05-02 19:01 UTC (permalink / raw)
To: Arnd Bergmann
Cc: Kees Cook, linux-kernel, x86, linux-doc, linux-arm-kernel, kvmarm,
linux-riscv, linux-s390, linux-efi, linux-hardening, linux-kbuild,
linux-security-module, linux-kselftest, sparclinux, kasan-dev,
llvm
Hi,
As part of looking at what GCC plugins could be replaced with Clang
implementations, this series uses the recently proposed stack depth
tracking callback in Clang[1] to implement the stackleak feature.
-Kees
[1] https://github.com/llvm/llvm-project/pull/138323
Kees Cook (4):
stackleak: Rename CONFIG_GCC_PLUGIN_STACKLEAK to CONFIG_STACKLEAK
stackleak: Rename stackleak_track_stack to __sanitizer_cov_stack_depth
stackleak: Split STACKLEAK_CFLAGS from GCC_PLUGINS_CFLAGS
stackleak: Support Clang stack depth tracking
Documentation/admin-guide/sysctl/kernel.rst | 2 +-
Documentation/security/self-protection.rst | 2 +-
arch/arm/boot/compressed/Makefile | 2 +-
arch/arm/kernel/entry-common.S | 2 +-
arch/arm/vdso/Makefile | 2 +-
arch/arm64/kernel/entry.S | 2 +-
arch/arm64/kernel/pi/Makefile | 2 +-
arch/arm64/kernel/vdso/Makefile | 1 +
arch/arm64/kvm/hyp/nvhe/Makefile | 2 +-
arch/riscv/kernel/entry.S | 2 +-
arch/riscv/kernel/pi/Makefile | 2 +-
arch/riscv/purgatory/Makefile | 2 +-
arch/s390/kernel/entry.S | 2 +-
arch/sparc/vdso/Makefile | 3 +-
arch/x86/entry/calling.h | 4 +-
arch/x86/entry/vdso/Makefile | 3 +-
arch/x86/include/asm/init.h | 2 +-
arch/x86/purgatory/Makefile | 2 +-
drivers/firmware/efi/libstub/Makefile | 6 +--
drivers/misc/lkdtm/stackleak.c | 8 ++--
include/linux/init.h | 4 +-
include/linux/sched.h | 4 +-
include/linux/stackleak.h | 6 +--
kernel/Makefile | 4 +-
kernel/stackleak.c | 4 +-
lib/Makefile | 2 +-
scripts/Makefile.gcc-plugins | 13 +++---
scripts/Makefile.ubsan | 12 +++++
scripts/gcc-plugins/stackleak_plugin.c | 52 ++++++++++-----------
security/Kconfig.hardening | 25 ++++++----
tools/objtool/check.c | 2 +-
tools/testing/selftests/lkdtm/config | 2 +-
32 files changed, 105 insertions(+), 78 deletions(-)
--
2.34.1
^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH RFC 1/4] stackleak: Rename CONFIG_GCC_PLUGIN_STACKLEAK to CONFIG_STACKLEAK
2025-05-02 19:01 [PATCH RFC 0/4] stackleak: Support Clang stack depth tracking Kees Cook
@ 2025-05-02 19:01 ` Kees Cook
2025-05-02 19:01 ` [PATCH RFC 2/4] stackleak: Rename stackleak_track_stack to __sanitizer_cov_stack_depth Kees Cook
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: Kees Cook @ 2025-05-02 19:01 UTC (permalink / raw)
To: Arnd Bergmann
Cc: Kees Cook, x86, Gustavo A. R. Silva, linux-doc, linux-arm-kernel,
kvmarm, linux-riscv, linux-s390, linux-efi, linux-hardening,
linux-kbuild, linux-security-module, linux-kselftest,
linux-kernel, sparclinux, kasan-dev, llvm
In preparation for adding Clang sanitizer coverage stack depth
tracking that can support stack depth callbacks, remove "GCC_PLUGIN"
from "CONFIG_GCC_PLUGIN_STACKLEAK" and remove "PLUGIN" from
"DISABLE_STACKLEAK_PLUGIN". Rearrange the Kconfig to have a top-level
CONFIG_STACKLEAK that will depend on either GCC plugins or Clang soon.
While here, also split "prev_lowest_stack" into CONFIG_STACKLEAK_METRICS,
since that's the only place it is referenced from.
Signed-off-by: Kees Cook <kees@kernel.org>
---
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: <x86@kernel.org>
Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Cc: <linux-doc@vger.kernel.org>
Cc: <linux-arm-kernel@lists.infradead.org>
Cc: <kvmarm@lists.linux.dev>
Cc: <linux-riscv@lists.infradead.org>
Cc: <linux-s390@vger.kernel.org>
Cc: <linux-efi@vger.kernel.org>
Cc: <linux-hardening@vger.kernel.org>
Cc: <linux-kbuild@vger.kernel.org>
Cc: <linux-security-module@vger.kernel.org>
Cc: <linux-kselftest@vger.kernel.org>
---
Documentation/admin-guide/sysctl/kernel.rst | 2 +-
Documentation/security/self-protection.rst | 2 +-
arch/arm/boot/compressed/Makefile | 2 +-
arch/arm/kernel/entry-common.S | 2 +-
arch/arm64/kernel/entry.S | 2 +-
arch/arm64/kernel/pi/Makefile | 2 +-
arch/arm64/kvm/hyp/nvhe/Makefile | 2 +-
arch/riscv/kernel/entry.S | 2 +-
arch/riscv/kernel/pi/Makefile | 2 +-
arch/riscv/purgatory/Makefile | 2 +-
arch/s390/kernel/entry.S | 2 +-
arch/x86/entry/calling.h | 4 ++--
arch/x86/purgatory/Makefile | 2 +-
drivers/firmware/efi/libstub/Makefile | 6 +++---
drivers/misc/lkdtm/stackleak.c | 8 ++++----
include/linux/sched.h | 4 +++-
include/linux/stackleak.h | 4 ++--
kernel/Makefile | 4 ++--
lib/Makefile | 2 +-
scripts/Makefile.gcc-plugins | 4 ++--
security/Kconfig.hardening | 18 +++++++++++-------
tools/testing/selftests/lkdtm/config | 2 +-
22 files changed, 43 insertions(+), 37 deletions(-)
diff --git a/Documentation/admin-guide/sysctl/kernel.rst b/Documentation/admin-guide/sysctl/kernel.rst
index dd49a89a62d3..c94475661a80 100644
--- a/Documentation/admin-guide/sysctl/kernel.rst
+++ b/Documentation/admin-guide/sysctl/kernel.rst
@@ -1465,7 +1465,7 @@ stack_erasing
=============
This parameter can be used to control kernel stack erasing at the end
-of syscalls for kernels built with ``CONFIG_GCC_PLUGIN_STACKLEAK``.
+of syscalls for kernels built with ``CONFIG_STACKLEAK``.
That erasing reduces the information which kernel stack leak bugs
can reveal and blocks some uninitialized stack variable attacks.
diff --git a/Documentation/security/self-protection.rst b/Documentation/security/self-protection.rst
index 910668e665cb..67a266d38172 100644
--- a/Documentation/security/self-protection.rst
+++ b/Documentation/security/self-protection.rst
@@ -303,7 +303,7 @@ Memory poisoning
When releasing memory, it is best to poison the contents, to avoid reuse
attacks that rely on the old contents of memory. E.g., clear stack on a
-syscall return (``CONFIG_GCC_PLUGIN_STACKLEAK``), wipe heap memory on a
+syscall return (``CONFIG_STACKLEAK``), wipe heap memory on a
free. This frustrates many uninitialized variable attacks, stack content
exposures, heap content exposures, and use-after-free attacks.
diff --git a/arch/arm/boot/compressed/Makefile b/arch/arm/boot/compressed/Makefile
index 945b5975fce2..2da39e41e5c0 100644
--- a/arch/arm/boot/compressed/Makefile
+++ b/arch/arm/boot/compressed/Makefile
@@ -9,7 +9,7 @@ OBJS =
HEAD = head.o
OBJS += misc.o decompress.o
-CFLAGS_decompress.o += $(DISABLE_STACKLEAK_PLUGIN)
+CFLAGS_decompress.o += $(DISABLE_STACKLEAK)
ifeq ($(CONFIG_DEBUG_UNCOMPRESS),y)
OBJS += debug.o
AFLAGS_head.o += -DDEBUG
diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S
index f379c852dcb7..9921898d29a1 100644
--- a/arch/arm/kernel/entry-common.S
+++ b/arch/arm/kernel/entry-common.S
@@ -119,7 +119,7 @@ no_work_pending:
ct_user_enter save = 0
-#ifdef CONFIG_GCC_PLUGIN_STACKLEAK
+#ifdef CONFIG_STACKLEAK
bl stackleak_erase_on_task_stack
#endif
restore_user_regs fast = 0, offset = 0
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index 5ae2a34b50bd..c5456ff920d3 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -614,7 +614,7 @@ SYM_CODE_END(ret_to_kernel)
SYM_CODE_START_LOCAL(ret_to_user)
ldr x19, [tsk, #TSK_TI_FLAGS] // re-check for single-step
enable_step_tsk x19, x2
-#ifdef CONFIG_GCC_PLUGIN_STACKLEAK
+#ifdef CONFIG_STACKLEAK
bl stackleak_erase_on_task_stack
#endif
kernel_exit 0
diff --git a/arch/arm64/kernel/pi/Makefile b/arch/arm64/kernel/pi/Makefile
index 4d11a8c29181..77159298f3c6 100644
--- a/arch/arm64/kernel/pi/Makefile
+++ b/arch/arm64/kernel/pi/Makefile
@@ -2,7 +2,7 @@
# Copyright 2022 Google LLC
KBUILD_CFLAGS := $(subst $(CC_FLAGS_FTRACE),,$(KBUILD_CFLAGS)) -fpie \
- -Os -DDISABLE_BRANCH_PROFILING $(DISABLE_STACKLEAK_PLUGIN) \
+ -Os -DDISABLE_BRANCH_PROFILING $(DISABLE_STACKLEAK) \
$(DISABLE_LATENT_ENTROPY_PLUGIN) \
$(call cc-option,-mbranch-protection=none) \
-I$(srctree)/scripts/dtc/libfdt -fno-stack-protector \
diff --git a/arch/arm64/kvm/hyp/nvhe/Makefile b/arch/arm64/kvm/hyp/nvhe/Makefile
index b43426a493df..4e00a2a8ad0c 100644
--- a/arch/arm64/kvm/hyp/nvhe/Makefile
+++ b/arch/arm64/kvm/hyp/nvhe/Makefile
@@ -12,7 +12,7 @@ asflags-y := -D__KVM_NVHE_HYPERVISOR__ -D__DISABLE_EXPORTS
ccflags-y := -D__KVM_NVHE_HYPERVISOR__ -D__DISABLE_EXPORTS -D__DISABLE_TRACE_MMIO__
ccflags-y += -fno-stack-protector \
-DDISABLE_BRANCH_PROFILING \
- $(DISABLE_STACKLEAK_PLUGIN)
+ $(DISABLE_STACKLEAK)
hostprogs := gen-hyprel
HOST_EXTRACFLAGS += -I$(objtree)/include
diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S
index 33a5a9f2a0d4..d6e9903817f7 100644
--- a/arch/riscv/kernel/entry.S
+++ b/arch/riscv/kernel/entry.S
@@ -220,7 +220,7 @@ SYM_CODE_START_NOALIGN(ret_from_exception)
#endif
bnez s0, 1f
-#ifdef CONFIG_GCC_PLUGIN_STACKLEAK
+#ifdef CONFIG_STACKLEAK
call stackleak_erase_on_task_stack
#endif
diff --git a/arch/riscv/kernel/pi/Makefile b/arch/riscv/kernel/pi/Makefile
index 81d69d45c06c..40238ed13ea1 100644
--- a/arch/riscv/kernel/pi/Makefile
+++ b/arch/riscv/kernel/pi/Makefile
@@ -2,7 +2,7 @@
# This file was copied from arm64/kernel/pi/Makefile.
KBUILD_CFLAGS := $(subst $(CC_FLAGS_FTRACE),,$(KBUILD_CFLAGS)) -fpie \
- -Os -DDISABLE_BRANCH_PROFILING $(DISABLE_STACKLEAK_PLUGIN) \
+ -Os -DDISABLE_BRANCH_PROFILING $(DISABLE_STACKLEAK) \
$(call cc-option,-mbranch-protection=none) \
-I$(srctree)/scripts/dtc/libfdt -fno-stack-protector \
-include $(srctree)/include/linux/hidden.h \
diff --git a/arch/riscv/purgatory/Makefile b/arch/riscv/purgatory/Makefile
index fb9c917c9b45..af8fa4aded5c 100644
--- a/arch/riscv/purgatory/Makefile
+++ b/arch/riscv/purgatory/Makefile
@@ -53,7 +53,7 @@ targets += purgatory.ro purgatory.chk
PURGATORY_CFLAGS_REMOVE := -mcmodel=kernel
PURGATORY_CFLAGS := -mcmodel=medany -ffreestanding -fno-zero-initialized-in-bss
-PURGATORY_CFLAGS += $(DISABLE_STACKLEAK_PLUGIN) -DDISABLE_BRANCH_PROFILING
+PURGATORY_CFLAGS += $(DISABLE_STACKLEAK) -DDISABLE_BRANCH_PROFILING
PURGATORY_CFLAGS += -fno-stack-protector -g0
# Default KBUILD_CFLAGS can have -pg option set when FTRACE is enabled. That
diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index dd291c9ad6a6..6b43318dc0cc 100644
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -124,7 +124,7 @@ _LPP_OFFSET = __LC_LPP
#endif
.macro STACKLEAK_ERASE
-#ifdef CONFIG_GCC_PLUGIN_STACKLEAK
+#ifdef CONFIG_STACKLEAK
brasl %r14,stackleak_erase_on_task_stack
#endif
.endm
diff --git a/arch/x86/entry/calling.h b/arch/x86/entry/calling.h
index d83236b96f22..790e63df94a2 100644
--- a/arch/x86/entry/calling.h
+++ b/arch/x86/entry/calling.h
@@ -369,7 +369,7 @@ For 32-bit we have the following conventions - kernel is built with
.endm
.macro STACKLEAK_ERASE_NOCLOBBER
-#ifdef CONFIG_GCC_PLUGIN_STACKLEAK
+#ifdef CONFIG_STACKLEAK
PUSH_AND_CLEAR_REGS
call stackleak_erase
POP_REGS
@@ -388,7 +388,7 @@ For 32-bit we have the following conventions - kernel is built with
#endif /* !CONFIG_X86_64 */
.macro STACKLEAK_ERASE
-#ifdef CONFIG_GCC_PLUGIN_STACKLEAK
+#ifdef CONFIG_STACKLEAK
call stackleak_erase
#endif
.endm
diff --git a/arch/x86/purgatory/Makefile b/arch/x86/purgatory/Makefile
index ebdfd7b84feb..5450d5f7fd88 100644
--- a/arch/x86/purgatory/Makefile
+++ b/arch/x86/purgatory/Makefile
@@ -35,7 +35,7 @@ targets += purgatory.ro purgatory.chk
PURGATORY_CFLAGS_REMOVE := -mcmodel=kernel
PURGATORY_CFLAGS := -mcmodel=small -ffreestanding -fno-zero-initialized-in-bss -g0
PURGATORY_CFLAGS += -fpic -fvisibility=hidden
-PURGATORY_CFLAGS += $(DISABLE_STACKLEAK_PLUGIN) -DDISABLE_BRANCH_PROFILING
+PURGATORY_CFLAGS += $(DISABLE_STACKLEAK) -DDISABLE_BRANCH_PROFILING
PURGATORY_CFLAGS += -fno-stack-protector
# Default KBUILD_CFLAGS can have -pg option set when FTRACE is enabled. That
diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile
index d23a1b9fed75..1cfdde43da02 100644
--- a/drivers/firmware/efi/libstub/Makefile
+++ b/drivers/firmware/efi/libstub/Makefile
@@ -22,15 +22,15 @@ cflags-$(CONFIG_X86) += -m$(BITS) -D__KERNEL__ -std=gnu11 \
# arm64 uses the full KBUILD_CFLAGS so it's necessary to explicitly
# disable the stackleak plugin
-cflags-$(CONFIG_ARM64) += -fpie $(DISABLE_STACKLEAK_PLUGIN) \
+cflags-$(CONFIG_ARM64) += -fpie $(DISABLE_STACKLEAK) \
-fno-unwind-tables -fno-asynchronous-unwind-tables
cflags-$(CONFIG_ARM) += -DEFI_HAVE_STRLEN -DEFI_HAVE_STRNLEN \
-DEFI_HAVE_MEMCHR -DEFI_HAVE_STRRCHR \
-DEFI_HAVE_STRCMP -fno-builtin -fpic \
$(call cc-option,-mno-single-pic-base) \
- $(DISABLE_STACKLEAK_PLUGIN)
+ $(DISABLE_STACKLEAK)
cflags-$(CONFIG_RISCV) += -fpic -DNO_ALTERNATIVE -mno-relax \
- $(DISABLE_STACKLEAK_PLUGIN)
+ $(DISABLE_STACKLEAK)
cflags-$(CONFIG_LOONGARCH) += -fpie
cflags-$(CONFIG_EFI_PARAMS_FROM_FDT) += -I$(srctree)/scripts/dtc/libfdt
diff --git a/drivers/misc/lkdtm/stackleak.c b/drivers/misc/lkdtm/stackleak.c
index f1d022160913..ab8c690a039a 100644
--- a/drivers/misc/lkdtm/stackleak.c
+++ b/drivers/misc/lkdtm/stackleak.c
@@ -11,7 +11,7 @@
#include "lkdtm.h"
#include <linux/stackleak.h>
-#if defined(CONFIG_GCC_PLUGIN_STACKLEAK)
+#if defined(CONFIG_STACKLEAK)
/*
* Check that stackleak tracks the lowest stack pointer and erases the stack
* below this as expected.
@@ -129,16 +129,16 @@ static void lkdtm_STACKLEAK_ERASING(void)
check_stackleak_irqoff();
local_irq_restore(flags);
}
-#else /* defined(CONFIG_GCC_PLUGIN_STACKLEAK) */
+#else /* defined(CONFIG_STACKLEAK) */
static void lkdtm_STACKLEAK_ERASING(void)
{
if (IS_ENABLED(CONFIG_HAVE_ARCH_STACKLEAK)) {
- pr_err("XFAIL: stackleak is not enabled (CONFIG_GCC_PLUGIN_STACKLEAK=n)\n");
+ pr_err("XFAIL: stackleak is not enabled (CONFIG_STACKLEAK=n)\n");
} else {
pr_err("XFAIL: stackleak is not supported on this arch (HAVE_ARCH_STACKLEAK=n)\n");
}
}
-#endif /* defined(CONFIG_GCC_PLUGIN_STACKLEAK) */
+#endif /* defined(CONFIG_STACKLEAK) */
static struct crashtype crashtypes[] = {
CRASHTYPE(STACKLEAK_ERASING),
diff --git a/include/linux/sched.h b/include/linux/sched.h
index f96ac1982893..f323a4d9f0ef 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1599,8 +1599,10 @@ struct task_struct {
/* Used by BPF for per-TASK xdp storage */
struct bpf_net_context *bpf_net_context;
-#ifdef CONFIG_GCC_PLUGIN_STACKLEAK
+#ifdef CONFIG_STACKLEAK
unsigned long lowest_stack;
+#endif
+#ifdef CONFIG_STACKLEAK_METRICS
unsigned long prev_lowest_stack;
#endif
diff --git a/include/linux/stackleak.h b/include/linux/stackleak.h
index 3be2cb564710..71e8242fd8f2 100644
--- a/include/linux/stackleak.h
+++ b/include/linux/stackleak.h
@@ -12,7 +12,7 @@
#define STACKLEAK_POISON -0xBEEF
#define STACKLEAK_SEARCH_DEPTH 128
-#ifdef CONFIG_GCC_PLUGIN_STACKLEAK
+#ifdef CONFIG_STACKLEAK
#include <asm/stacktrace.h>
#include <linux/linkage.h>
@@ -82,7 +82,7 @@ asmlinkage void noinstr stackleak_erase_on_task_stack(void);
asmlinkage void noinstr stackleak_erase_off_task_stack(void);
void __no_caller_saved_registers noinstr stackleak_track_stack(void);
-#else /* !CONFIG_GCC_PLUGIN_STACKLEAK */
+#else /* !CONFIG_STACKLEAK */
static inline void stackleak_task_init(struct task_struct *t) { }
#endif
diff --git a/kernel/Makefile b/kernel/Makefile
index 434929de17ef..79583e3501b4 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -137,8 +137,8 @@ obj-$(CONFIG_WATCH_QUEUE) += watch_queue.o
obj-$(CONFIG_RESOURCE_KUNIT_TEST) += resource_kunit.o
obj-$(CONFIG_SYSCTL_KUNIT_TEST) += sysctl-test.o
-CFLAGS_stackleak.o += $(DISABLE_STACKLEAK_PLUGIN)
-obj-$(CONFIG_GCC_PLUGIN_STACKLEAK) += stackleak.o
+CFLAGS_stackleak.o += $(DISABLE_STACKLEAK)
+obj-$(CONFIG_STACKLEAK) += stackleak.o
KASAN_SANITIZE_stackleak.o := n
KCSAN_SANITIZE_stackleak.o := n
KCOV_INSTRUMENT_stackleak.o := n
diff --git a/lib/Makefile b/lib/Makefile
index f07b24ce1b3f..720c4846d255 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -338,7 +338,7 @@ obj-$(CONFIG_UBSAN) += ubsan.o
UBSAN_SANITIZE_ubsan.o := n
KASAN_SANITIZE_ubsan.o := n
KCSAN_SANITIZE_ubsan.o := n
-CFLAGS_ubsan.o := -fno-stack-protector $(DISABLE_STACKLEAK_PLUGIN)
+CFLAGS_ubsan.o := -fno-stack-protector $(DISABLE_STACKLEAK)
obj-$(CONFIG_SBITMAP) += sbitmap.o
diff --git a/scripts/Makefile.gcc-plugins b/scripts/Makefile.gcc-plugins
index e4deaf5fa571..e3ed92e20d16 100644
--- a/scripts/Makefile.gcc-plugins
+++ b/scripts/Makefile.gcc-plugins
@@ -32,9 +32,9 @@ gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_STACKLEAK) \
gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_STACKLEAK_VERBOSE) \
+= -fplugin-arg-stackleak_plugin-verbose
ifdef CONFIG_GCC_PLUGIN_STACKLEAK
- DISABLE_STACKLEAK_PLUGIN += -fplugin-arg-stackleak_plugin-disable
+ DISABLE_STACKLEAK += -fplugin-arg-stackleak_plugin-disable
endif
-export DISABLE_STACKLEAK_PLUGIN
+export DISABLE_STACKLEAK
gcc-plugin-$(CONFIG_GCC_PLUGIN_ARM_SSP_PER_TASK) += arm_ssp_per_task_plugin.so
ifdef CONFIG_GCC_PLUGIN_ARM_SSP_PER_TASK
diff --git a/security/Kconfig.hardening b/security/Kconfig.hardening
index 3fe9d7b945c4..8aa5c1d4794d 100644
--- a/security/Kconfig.hardening
+++ b/security/Kconfig.hardening
@@ -158,10 +158,10 @@ config GCC_PLUGIN_STRUCTLEAK_VERBOSE
initialized. Since not all existing initializers are detected
by the plugin, this can produce false positive warnings.
-config GCC_PLUGIN_STACKLEAK
+config STACKLEAK
bool "Poison kernel stack before returning from syscalls"
- depends on GCC_PLUGINS
depends on HAVE_ARCH_STACKLEAK
+ depends on GCC_PLUGINS
help
This option makes the kernel erase the kernel stack before
returning from system calls. This has the effect of leaving
@@ -179,6 +179,10 @@ config GCC_PLUGIN_STACKLEAK
are advised to test this feature on your expected workload before
deploying it.
+config GCC_PLUGIN_STACKLEAK
+ def_bool STACKLEAK
+ depends on GCC_PLUGINS
+ help
This plugin was ported from grsecurity/PaX. More information at:
* https://grsecurity.net/
* https://pax.grsecurity.net/
@@ -197,9 +201,9 @@ config STACKLEAK_TRACK_MIN_SIZE
int "Minimum stack frame size of functions tracked by STACKLEAK"
default 100
range 0 4096
- depends on GCC_PLUGIN_STACKLEAK
+ depends on STACKLEAK
help
- The STACKLEAK gcc plugin instruments the kernel code for tracking
+ The STACKLEAK options instruments the kernel code for tracking
the lowest border of the kernel stack (and for some other purposes).
It inserts the stackleak_track_stack() call for the functions with
a stack frame size greater than or equal to this parameter.
@@ -207,7 +211,7 @@ config STACKLEAK_TRACK_MIN_SIZE
config STACKLEAK_METRICS
bool "Show STACKLEAK metrics in the /proc file system"
- depends on GCC_PLUGIN_STACKLEAK
+ depends on STACKLEAK
depends on PROC_FS
help
If this is set, STACKLEAK metrics for every task are available in
@@ -219,11 +223,11 @@ config STACKLEAK_METRICS
config STACKLEAK_RUNTIME_DISABLE
bool "Allow runtime disabling of kernel stack erasing"
- depends on GCC_PLUGIN_STACKLEAK
+ depends on STACKLEAK
help
This option provides 'stack_erasing' sysctl, which can be used in
runtime to control kernel stack erasing for kernels built with
- CONFIG_GCC_PLUGIN_STACKLEAK.
+ CONFIG_STACKLEAK.
config INIT_ON_ALLOC_DEFAULT_ON
bool "Enable heap memory zeroing on allocation by default"
diff --git a/tools/testing/selftests/lkdtm/config b/tools/testing/selftests/lkdtm/config
index 7afe05e8c4d7..b9b1275c07e8 100644
--- a/tools/testing/selftests/lkdtm/config
+++ b/tools/testing/selftests/lkdtm/config
@@ -2,7 +2,7 @@ CONFIG_LKDTM=y
CONFIG_DEBUG_LIST=y
CONFIG_SLAB_FREELIST_HARDENED=y
CONFIG_FORTIFY_SOURCE=y
-CONFIG_GCC_PLUGIN_STACKLEAK=y
+CONFIG_STACKLEAK=y
CONFIG_HARDENED_USERCOPY=y
CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT=y
CONFIG_INIT_ON_FREE_DEFAULT_ON=y
--
2.34.1
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH RFC 2/4] stackleak: Rename stackleak_track_stack to __sanitizer_cov_stack_depth
2025-05-02 19:01 [PATCH RFC 0/4] stackleak: Support Clang stack depth tracking Kees Cook
2025-05-02 19:01 ` [PATCH RFC 1/4] stackleak: Rename CONFIG_GCC_PLUGIN_STACKLEAK to CONFIG_STACKLEAK Kees Cook
@ 2025-05-02 19:01 ` Kees Cook
2025-05-02 19:01 ` [PATCH RFC 3/4] stackleak: Split STACKLEAK_CFLAGS from GCC_PLUGINS_CFLAGS Kees Cook
2025-05-02 19:01 ` [PATCH RFC 4/4] stackleak: Support Clang stack depth tracking Kees Cook
3 siblings, 0 replies; 5+ messages in thread
From: Kees Cook @ 2025-05-02 19:01 UTC (permalink / raw)
To: Arnd Bergmann
Cc: Kees Cook, linux-hardening, linux-kernel, x86, linux-doc,
linux-arm-kernel, kvmarm, linux-riscv, linux-s390, linux-efi,
linux-kbuild, linux-security-module, linux-kselftest, sparclinux,
kasan-dev, llvm
The Clang stack depth tracking implementation has a fixed name for the
stack depth tracking callback, "__sanitizer_cov_stack_depth", so rename
the GCC plugin function to match.
Signed-off-by: Kees Cook <kees@kernel.org>
---
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: <linux-hardening@vger.kernel.org>
---
include/linux/stackleak.h | 2 +-
kernel/stackleak.c | 4 +-
scripts/gcc-plugins/stackleak_plugin.c | 52 +++++++++++++-------------
security/Kconfig.hardening | 4 +-
tools/objtool/check.c | 2 +-
5 files changed, 32 insertions(+), 32 deletions(-)
diff --git a/include/linux/stackleak.h b/include/linux/stackleak.h
index 71e8242fd8f2..a669574a3562 100644
--- a/include/linux/stackleak.h
+++ b/include/linux/stackleak.h
@@ -80,7 +80,7 @@ static inline void stackleak_task_init(struct task_struct *t)
asmlinkage void noinstr stackleak_erase(void);
asmlinkage void noinstr stackleak_erase_on_task_stack(void);
asmlinkage void noinstr stackleak_erase_off_task_stack(void);
-void __no_caller_saved_registers noinstr stackleak_track_stack(void);
+void __no_caller_saved_registers noinstr __sanitizer_cov_stack_depth(void);
#else /* !CONFIG_STACKLEAK */
static inline void stackleak_task_init(struct task_struct *t) { }
diff --git a/kernel/stackleak.c b/kernel/stackleak.c
index bb65321761b4..5158468968e2 100644
--- a/kernel/stackleak.c
+++ b/kernel/stackleak.c
@@ -156,7 +156,7 @@ asmlinkage void noinstr stackleak_erase_off_task_stack(void)
__stackleak_erase(false);
}
-void __used __no_caller_saved_registers noinstr stackleak_track_stack(void)
+void __used __no_caller_saved_registers noinstr __sanitizer_cov_stack_depth(void)
{
unsigned long sp = current_stack_pointer;
@@ -174,4 +174,4 @@ void __used __no_caller_saved_registers noinstr stackleak_track_stack(void)
current->lowest_stack = sp;
}
}
-EXPORT_SYMBOL(stackleak_track_stack);
+EXPORT_SYMBOL(__sanitizer_cov_stack_depth);
diff --git a/scripts/gcc-plugins/stackleak_plugin.c b/scripts/gcc-plugins/stackleak_plugin.c
index d20c47d21ad8..e486488c867d 100644
--- a/scripts/gcc-plugins/stackleak_plugin.c
+++ b/scripts/gcc-plugins/stackleak_plugin.c
@@ -9,7 +9,7 @@
* any of the gcc libraries
*
* This gcc plugin is needed for tracking the lowest border of the kernel stack.
- * It instruments the kernel code inserting stackleak_track_stack() calls:
+ * It instruments the kernel code inserting __sanitizer_cov_stack_depth() calls:
* - after alloca();
* - for the functions with a stack frame size greater than or equal
* to the "track-min-size" plugin parameter.
@@ -33,7 +33,7 @@ __visible int plugin_is_GPL_compatible;
static int track_frame_size = -1;
static bool build_for_x86 = false;
-static const char track_function[] = "stackleak_track_stack";
+static const char track_function[] = "__sanitizer_cov_stack_depth";
static bool disable = false;
static bool verbose = false;
@@ -58,7 +58,7 @@ static void add_stack_tracking_gcall(gimple_stmt_iterator *gsi, bool after)
cgraph_node_ptr node;
basic_block bb;
- /* Insert calling stackleak_track_stack() */
+ /* Insert calling __sanitizer_cov_stack_depth() */
stmt = gimple_build_call(track_function_decl, 0);
gimple_call = as_a_gcall(stmt);
if (after)
@@ -120,12 +120,12 @@ static void add_stack_tracking_gasm(gimple_stmt_iterator *gsi, bool after)
gcc_assert(build_for_x86);
/*
- * Insert calling stackleak_track_stack() in asm:
- * asm volatile("call stackleak_track_stack"
+ * Insert calling __sanitizer_cov_stack_depth() in asm:
+ * asm volatile("call __sanitizer_cov_stack_depth"
* :: "r" (current_stack_pointer))
* Use ASM_CALL_CONSTRAINT trick from arch/x86/include/asm/asm.h.
* This constraint is taken into account during gcc shrink-wrapping
- * optimization. It is needed to be sure that stackleak_track_stack()
+ * optimization. It is needed to be sure that __sanitizer_cov_stack_depth()
* call is inserted after the prologue of the containing function,
* when the stack frame is prepared.
*/
@@ -137,7 +137,7 @@ static void add_stack_tracking_gasm(gimple_stmt_iterator *gsi, bool after)
input = build_tree_list(NULL_TREE, build_const_char_string(2, "r"));
input = chainon(NULL_TREE, build_tree_list(input, sp_decl));
vec_safe_push(inputs, input);
- asm_call = gimple_build_asm_vec("call stackleak_track_stack",
+ asm_call = gimple_build_asm_vec("call __sanitizer_cov_stack_depth",
inputs, NULL, NULL, NULL);
gimple_asm_set_volatile(asm_call, true);
if (after)
@@ -151,11 +151,11 @@ static void add_stack_tracking(gimple_stmt_iterator *gsi, bool after)
{
/*
* The 'no_caller_saved_registers' attribute is used for
- * stackleak_track_stack(). If the compiler supports this attribute for
- * the target arch, we can add calling stackleak_track_stack() in asm.
+ * __sanitizer_cov_stack_depth(). If the compiler supports this attribute for
+ * the target arch, we can add calling __sanitizer_cov_stack_depth() in asm.
* That improves performance: we avoid useless operations with the
* caller-saved registers in the functions from which we will remove
- * stackleak_track_stack() call during the stackleak_cleanup pass.
+ * __sanitizer_cov_stack_depth() call during the stackleak_cleanup pass.
*/
if (lookup_attribute_spec(get_identifier("no_caller_saved_registers")))
add_stack_tracking_gasm(gsi, after);
@@ -165,7 +165,7 @@ static void add_stack_tracking(gimple_stmt_iterator *gsi, bool after)
/*
* Work with the GIMPLE representation of the code. Insert the
- * stackleak_track_stack() call after alloca() and into the beginning
+ * __sanitizer_cov_stack_depth() call after alloca() and into the beginning
* of the function if it is not instrumented.
*/
static unsigned int stackleak_instrument_execute(void)
@@ -205,7 +205,7 @@ static unsigned int stackleak_instrument_execute(void)
DECL_NAME_POINTER(current_function_decl));
}
- /* Insert stackleak_track_stack() call after alloca() */
+ /* Insert __sanitizer_cov_stack_depth() call after alloca() */
add_stack_tracking(&gsi, true);
if (bb == entry_bb)
prologue_instrumented = true;
@@ -241,7 +241,7 @@ static unsigned int stackleak_instrument_execute(void)
return 0;
}
- /* Insert stackleak_track_stack() call at the function beginning */
+ /* Insert __sanitizer_cov_stack_depth() call at the function beginning */
bb = entry_bb;
if (!single_pred_p(bb)) {
/* gcc_assert(bb_loop_depth(bb) ||
@@ -270,15 +270,15 @@ static void remove_stack_tracking_gcall(void)
rtx_insn *insn, *next;
/*
- * Find stackleak_track_stack() calls. Loop through the chain of insns,
+ * Find __sanitizer_cov_stack_depth() calls. Loop through the chain of insns,
* which is an RTL representation of the code for a function.
*
* The example of a matching insn:
- * (call_insn 8 4 10 2 (call (mem (symbol_ref ("stackleak_track_stack")
- * [flags 0x41] <function_decl 0x7f7cd3302a80 stackleak_track_stack>)
- * [0 stackleak_track_stack S1 A8]) (0)) 675 {*call} (expr_list
- * (symbol_ref ("stackleak_track_stack") [flags 0x41] <function_decl
- * 0x7f7cd3302a80 stackleak_track_stack>) (expr_list (0) (nil))) (nil))
+ * (call_insn 8 4 10 2 (call (mem (symbol_ref ("__sanitizer_cov_stack_depth")
+ * [flags 0x41] <function_decl 0x7f7cd3302a80 __sanitizer_cov_stack_depth>)
+ * [0 __sanitizer_cov_stack_depth S1 A8]) (0)) 675 {*call} (expr_list
+ * (symbol_ref ("__sanitizer_cov_stack_depth") [flags 0x41] <function_decl
+ * 0x7f7cd3302a80 __sanitizer_cov_stack_depth>) (expr_list (0) (nil))) (nil))
*/
for (insn = get_insns(); insn; insn = next) {
rtx body;
@@ -318,7 +318,7 @@ static void remove_stack_tracking_gcall(void)
if (SYMBOL_REF_DECL(body) != track_function_decl)
continue;
- /* Delete the stackleak_track_stack() call */
+ /* Delete the __sanitizer_cov_stack_depth() call */
delete_insn_and_edges(insn);
#if BUILDING_GCC_VERSION < 8000
if (GET_CODE(next) == NOTE &&
@@ -340,12 +340,12 @@ static bool remove_stack_tracking_gasm(void)
gcc_assert(build_for_x86);
/*
- * Find stackleak_track_stack() asm calls. Loop through the chain of
+ * Find __sanitizer_cov_stack_depth() asm calls. Loop through the chain of
* insns, which is an RTL representation of the code for a function.
*
* The example of a matching insn:
* (insn 11 5 12 2 (parallel [ (asm_operands/v
- * ("call stackleak_track_stack") ("") 0
+ * ("call __sanitizer_cov_stack_depth") ("") 0
* [ (reg/v:DI 7 sp [ current_stack_pointer ]) ]
* [ (asm_input:DI ("r")) ] [])
* (clobber (reg:CC 17 flags)) ]) -1 (nil))
@@ -375,7 +375,7 @@ static bool remove_stack_tracking_gasm(void)
continue;
if (strcmp(ASM_OPERANDS_TEMPLATE(body),
- "call stackleak_track_stack")) {
+ "call __sanitizer_cov_stack_depth")) {
continue;
}
@@ -389,7 +389,7 @@ static bool remove_stack_tracking_gasm(void)
/*
* Work with the RTL representation of the code.
- * Remove the unneeded stackleak_track_stack() calls from the functions
+ * Remove the unneeded __sanitizer_cov_stack_depth() calls from the functions
* which don't call alloca() and don't have a large enough stack frame size.
*/
static unsigned int stackleak_cleanup_execute(void)
@@ -474,13 +474,13 @@ static bool stackleak_gate(void)
return track_frame_size >= 0;
}
-/* Build the function declaration for stackleak_track_stack() */
+/* Build the function declaration for __sanitizer_cov_stack_depth() */
static void stackleak_start_unit(void *gcc_data __unused,
void *user_data __unused)
{
tree fntype;
- /* void stackleak_track_stack(void) */
+ /* void __sanitizer_cov_stack_depth(void) */
fntype = build_function_type_list(void_type_node, NULL_TREE);
track_function_decl = build_fn_decl(track_function, fntype);
DECL_ASSEMBLER_NAME(track_function_decl); /* for LTO */
diff --git a/security/Kconfig.hardening b/security/Kconfig.hardening
index 8aa5c1d4794d..edcc489a6805 100644
--- a/security/Kconfig.hardening
+++ b/security/Kconfig.hardening
@@ -205,8 +205,8 @@ config STACKLEAK_TRACK_MIN_SIZE
help
The STACKLEAK options instruments the kernel code for tracking
the lowest border of the kernel stack (and for some other purposes).
- It inserts the stackleak_track_stack() call for the functions with
- a stack frame size greater than or equal to this parameter.
+ It inserts the __sanitizer_cov_stack_depth() call for the functions
+ with a stack frame size greater than or equal to this parameter.
If unsure, leave the default value 100.
config STACKLEAK_METRICS
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 3a411064fa34..05d0095c1384 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -1191,7 +1191,7 @@ static const char *uaccess_safe_builtin[] = {
"__ubsan_handle_shift_out_of_bounds",
"__ubsan_handle_load_invalid_value",
/* STACKLEAK */
- "stackleak_track_stack",
+ "__sanitizer_cov_stack_depth",
/* TRACE_BRANCH_PROFILING */
"ftrace_likely_update",
/* STACKPROTECTOR */
--
2.34.1
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH RFC 3/4] stackleak: Split STACKLEAK_CFLAGS from GCC_PLUGINS_CFLAGS
2025-05-02 19:01 [PATCH RFC 0/4] stackleak: Support Clang stack depth tracking Kees Cook
2025-05-02 19:01 ` [PATCH RFC 1/4] stackleak: Rename CONFIG_GCC_PLUGIN_STACKLEAK to CONFIG_STACKLEAK Kees Cook
2025-05-02 19:01 ` [PATCH RFC 2/4] stackleak: Rename stackleak_track_stack to __sanitizer_cov_stack_depth Kees Cook
@ 2025-05-02 19:01 ` Kees Cook
2025-05-02 19:01 ` [PATCH RFC 4/4] stackleak: Support Clang stack depth tracking Kees Cook
3 siblings, 0 replies; 5+ messages in thread
From: Kees Cook @ 2025-05-02 19:01 UTC (permalink / raw)
To: Arnd Bergmann
Cc: Kees Cook, x86, linux-arm-kernel, sparclinux, linux-kbuild,
linux-hardening, linux-kernel, linux-doc, kvmarm, linux-riscv,
linux-s390, linux-efi, linux-security-module, linux-kselftest,
kasan-dev, llvm
In preparation for Clang stack depth tracking for stackleak, split the
stackleak-specific cflags out of GCC_PLUGINS_CFLAGS into
STACKLEAK_CFLAGS.
Signed-off-by: Kees Cook <kees@kernel.org>
---
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: <x86@kernel.org>
Cc: <linux-arm-kernel@lists.infradead.org>
Cc: <sparclinux@vger.kernel.org>
Cc: <linux-kbuild@vger.kernel.org>
Cc: <linux-hardening@vger.kernel.org>
---
arch/arm/vdso/Makefile | 2 +-
arch/arm64/kernel/vdso/Makefile | 1 +
arch/sparc/vdso/Makefile | 3 ++-
arch/x86/entry/vdso/Makefile | 3 ++-
scripts/Makefile.gcc-plugins | 11 ++++++-----
5 files changed, 12 insertions(+), 8 deletions(-)
diff --git a/arch/arm/vdso/Makefile b/arch/arm/vdso/Makefile
index cb044bfd145d..92748e341b7d 100644
--- a/arch/arm/vdso/Makefile
+++ b/arch/arm/vdso/Makefile
@@ -26,7 +26,7 @@ CPPFLAGS_vdso.lds += -P -C -U$(ARCH)
CFLAGS_REMOVE_vdso.o = -pg
# Force -O2 to avoid libgcc dependencies
-CFLAGS_REMOVE_vgettimeofday.o = -pg -Os $(RANDSTRUCT_CFLAGS) $(GCC_PLUGINS_CFLAGS)
+CFLAGS_REMOVE_vgettimeofday.o = -pg -Os $(RANDSTRUCT_CFLAGS) $(GCC_PLUGINS_CFLAGS) $(STACKLEAK_CFLAGS)
ifeq ($(c-gettimeofday-y),)
CFLAGS_vgettimeofday.o = -O2
else
diff --git a/arch/arm64/kernel/vdso/Makefile b/arch/arm64/kernel/vdso/Makefile
index 5e27e46aa496..fb17749b93cf 100644
--- a/arch/arm64/kernel/vdso/Makefile
+++ b/arch/arm64/kernel/vdso/Makefile
@@ -37,6 +37,7 @@ ccflags-y += -DDISABLE_BRANCH_PROFILING -DBUILD_VDSO
# the CFLAGS to make possible to build the kernel with CONFIG_WERROR enabled.
CC_FLAGS_REMOVE_VDSO := $(CC_FLAGS_FTRACE) -Os $(CC_FLAGS_SCS) \
$(RANDSTRUCT_CFLAGS) $(GCC_PLUGINS_CFLAGS) \
+ $(STACKLEAK_CFLAGS) \
$(CC_FLAGS_LTO) $(CC_FLAGS_CFI) \
-Wmissing-prototypes -Wmissing-declarations
diff --git a/arch/sparc/vdso/Makefile b/arch/sparc/vdso/Makefile
index fdc4a8f5a49c..162a0235f41f 100644
--- a/arch/sparc/vdso/Makefile
+++ b/arch/sparc/vdso/Makefile
@@ -48,7 +48,7 @@ CFL := $(PROFILING) -mcmodel=medlow -fPIC -O2 -fasynchronous-unwind-tables -m64
SPARC_REG_CFLAGS = -ffixed-g4 -ffixed-g5 $(call cc-option,-fcall-used-g5) $(call cc-option,-fcall-used-g7)
-$(vobjs): KBUILD_CFLAGS := $(filter-out $(RANDSTRUCT_CFLAGS) $(GCC_PLUGINS_CFLAGS) $(SPARC_REG_CFLAGS),$(KBUILD_CFLAGS)) $(CFL)
+$(vobjs): KBUILD_CFLAGS := $(filter-out $(RANDSTRUCT_CFLAGS) $(GCC_PLUGINS_CFLAGS) $(STACKLEAK_CFLAGS) $(SPARC_REG_CFLAGS),$(KBUILD_CFLAGS)) $(CFL)
#
# vDSO code runs in userspace and -pg doesn't help with profiling anyway.
@@ -80,6 +80,7 @@ KBUILD_CFLAGS_32 := $(filter-out -mcmodel=medlow,$(KBUILD_CFLAGS_32))
KBUILD_CFLAGS_32 := $(filter-out -fno-pic,$(KBUILD_CFLAGS_32))
KBUILD_CFLAGS_32 := $(filter-out $(RANDSTRUCT_CFLAGS),$(KBUILD_CFLAGS_32))
KBUILD_CFLAGS_32 := $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS_32))
+KBUILD_CFLAGS_32 := $(filter-out $(STACKLEAK_CFLAGS),$(KBUILD_CFLAGS_32))
KBUILD_CFLAGS_32 := $(filter-out $(SPARC_REG_CFLAGS),$(KBUILD_CFLAGS_32))
KBUILD_CFLAGS_32 += -m32 -msoft-float -fpic
KBUILD_CFLAGS_32 += -fno-stack-protector
diff --git a/arch/x86/entry/vdso/Makefile b/arch/x86/entry/vdso/Makefile
index 54d3e9774d62..cd5249b6ef84 100644
--- a/arch/x86/entry/vdso/Makefile
+++ b/arch/x86/entry/vdso/Makefile
@@ -62,7 +62,7 @@ ifneq ($(RETPOLINE_VDSO_CFLAGS),)
endif
endif
-$(vobjs): KBUILD_CFLAGS := $(filter-out $(PADDING_CFLAGS) $(CC_FLAGS_LTO) $(CC_FLAGS_CFI) $(RANDSTRUCT_CFLAGS) $(GCC_PLUGINS_CFLAGS) $(RETPOLINE_CFLAGS),$(KBUILD_CFLAGS)) $(CFL)
+$(vobjs): KBUILD_CFLAGS := $(filter-out $(PADDING_CFLAGS) $(CC_FLAGS_LTO) $(CC_FLAGS_CFI) $(RANDSTRUCT_CFLAGS) $(GCC_PLUGINS_CFLAGS) $(STACKLEAK_CFLAGS) $(RETPOLINE_CFLAGS),$(KBUILD_CFLAGS)) $(CFL)
$(vobjs): KBUILD_AFLAGS += -DBUILD_VDSO
#
@@ -124,6 +124,7 @@ KBUILD_CFLAGS_32 := $(filter-out -fno-pic,$(KBUILD_CFLAGS_32))
KBUILD_CFLAGS_32 := $(filter-out -mfentry,$(KBUILD_CFLAGS_32))
KBUILD_CFLAGS_32 := $(filter-out $(RANDSTRUCT_CFLAGS),$(KBUILD_CFLAGS_32))
KBUILD_CFLAGS_32 := $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS_32))
+KBUILD_CFLAGS_32 := $(filter-out $(STACKLEAK_CFLAGS),$(KBUILD_CFLAGS_32))
KBUILD_CFLAGS_32 := $(filter-out $(RETPOLINE_CFLAGS),$(KBUILD_CFLAGS_32))
KBUILD_CFLAGS_32 := $(filter-out $(CC_FLAGS_LTO),$(KBUILD_CFLAGS_32))
KBUILD_CFLAGS_32 := $(filter-out $(CC_FLAGS_CFI),$(KBUILD_CFLAGS_32))
diff --git a/scripts/Makefile.gcc-plugins b/scripts/Makefile.gcc-plugins
index e3ed92e20d16..398b70e2d270 100644
--- a/scripts/Makefile.gcc-plugins
+++ b/scripts/Makefile.gcc-plugins
@@ -23,18 +23,19 @@ gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_STRUCTLEAK) \
+= -DSTRUCTLEAK_PLUGIN
gcc-plugin-$(CONFIG_GCC_PLUGIN_STACKLEAK) += stackleak_plugin.so
-gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_STACKLEAK) \
+gcc-plugin-stackleak-cflags-$(CONFIG_GCC_PLUGIN_STACKLEAK) \
+= -DSTACKLEAK_PLUGIN
-gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_STACKLEAK) \
+gcc-plugin-stackleak-cflags-$(CONFIG_GCC_PLUGIN_STACKLEAK) \
+= -fplugin-arg-stackleak_plugin-track-min-size=$(CONFIG_STACKLEAK_TRACK_MIN_SIZE)
-gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_STACKLEAK) \
+gcc-plugin-stackleak-cflags-$(CONFIG_GCC_PLUGIN_STACKLEAK) \
+= -fplugin-arg-stackleak_plugin-arch=$(SRCARCH)
-gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_STACKLEAK_VERBOSE) \
+gcc-plugin-stackleak-cflags-$(CONFIG_GCC_PLUGIN_STACKLEAK_VERBOSE) \
+= -fplugin-arg-stackleak_plugin-verbose
ifdef CONFIG_GCC_PLUGIN_STACKLEAK
+ STACKLEAK_CFLAGS = $(gcc-plugin-stackleak-cflags-y)
DISABLE_STACKLEAK += -fplugin-arg-stackleak_plugin-disable
endif
-export DISABLE_STACKLEAK
+export STACKLEAK_CFLAGS DISABLE_STACKLEAK
gcc-plugin-$(CONFIG_GCC_PLUGIN_ARM_SSP_PER_TASK) += arm_ssp_per_task_plugin.so
ifdef CONFIG_GCC_PLUGIN_ARM_SSP_PER_TASK
--
2.34.1
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH RFC 4/4] stackleak: Support Clang stack depth tracking
2025-05-02 19:01 [PATCH RFC 0/4] stackleak: Support Clang stack depth tracking Kees Cook
` (2 preceding siblings ...)
2025-05-02 19:01 ` [PATCH RFC 3/4] stackleak: Split STACKLEAK_CFLAGS from GCC_PLUGINS_CFLAGS Kees Cook
@ 2025-05-02 19:01 ` Kees Cook
3 siblings, 0 replies; 5+ messages in thread
From: Kees Cook @ 2025-05-02 19:01 UTC (permalink / raw)
To: Arnd Bergmann
Cc: Kees Cook, Thomas Gleixner, Ingo Molnar, Borislav Petkov,
Dave Hansen, x86, H. Peter Anvin, Masahiro Yamada,
Nathan Chancellor, Nicolas Schier, Marco Elver, Andrey Konovalov,
Andrey Ryabinin, Ard Biesheuvel, Gustavo A. R. Silva, Paul Moore,
James Morris, Serge E. Hallyn, Kai Huang, Hou Wenlong,
Kirill A. Shutemov, Andrew Morton, Peter Zijlstra (Intel),
Sami Tolvanen, Christophe Leroy, linux-kbuild, kasan-dev,
linux-hardening, linux-security-module, linux-kernel, linux-doc,
linux-arm-kernel, kvmarm, linux-riscv, linux-s390, linux-efi,
linux-kselftest, sparclinux, llvm
Wire up stackleak to Clang's proposed[1] stack depth tracking callback
option. While __noinstr already contained __no_sanitize_coverage, it was
still needed for __init and __head section markings. This is needed to
make sure the callback is not executed in unsupported contexts.
Link: https://github.com/llvm/llvm-project/pull/138323 [1]
Signed-off-by: Kees Cook <kees@kernel.org>
---
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: <x86@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nicolas Schier <nicolas.schier@linux.dev>
Cc: Marco Elver <elver@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Cc: Paul Moore <paul@paul-moore.com>
Cc: James Morris <jmorris@namei.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Kai Huang <kai.huang@intel.com>
Cc: Hou Wenlong <houwenlong.hwl@antgroup.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: Sami Tolvanen <samitolvanen@google.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: <linux-kbuild@vger.kernel.org>
Cc: <kasan-dev@googlegroups.com>
Cc: <linux-hardening@vger.kernel.org>
Cc: <linux-security-module@vger.kernel.org>
---
arch/x86/include/asm/init.h | 2 +-
include/linux/init.h | 4 +++-
scripts/Makefile.ubsan | 12 ++++++++++++
security/Kconfig.hardening | 5 ++++-
4 files changed, 20 insertions(+), 3 deletions(-)
diff --git a/arch/x86/include/asm/init.h b/arch/x86/include/asm/init.h
index 8b1b1abcef15..6bfdaeddbae8 100644
--- a/arch/x86/include/asm/init.h
+++ b/arch/x86/include/asm/init.h
@@ -5,7 +5,7 @@
#if defined(CONFIG_CC_IS_CLANG) && CONFIG_CLANG_VERSION < 170000
#define __head __section(".head.text") __no_sanitize_undefined __no_stack_protector
#else
-#define __head __section(".head.text") __no_sanitize_undefined
+#define __head __section(".head.text") __no_sanitize_undefined __no_sanitize_coverage
#endif
struct x86_mapping_info {
diff --git a/include/linux/init.h b/include/linux/init.h
index ee1309473bc6..c65a050d52a7 100644
--- a/include/linux/init.h
+++ b/include/linux/init.h
@@ -49,7 +49,9 @@
/* These are for everybody (although not all archs will actually
discard it in modules) */
-#define __init __section(".init.text") __cold __latent_entropy __noinitretpoline
+#define __init __section(".init.text") __cold __latent_entropy \
+ __noinitretpoline \
+ __no_sanitize_coverage
#define __initdata __section(".init.data")
#define __initconst __section(".init.rodata")
#define __exitdata __section(".exit.data")
diff --git a/scripts/Makefile.ubsan b/scripts/Makefile.ubsan
index 9e35198edbf0..cfb3ecde07dd 100644
--- a/scripts/Makefile.ubsan
+++ b/scripts/Makefile.ubsan
@@ -22,3 +22,15 @@ ubsan-integer-wrap-cflags-$(CONFIG_UBSAN_INTEGER_WRAP) += \
-fsanitize=implicit-unsigned-integer-truncation \
-fsanitize-ignorelist=$(srctree)/scripts/integer-wrap-ignore.scl
export CFLAGS_UBSAN_INTEGER_WRAP := $(ubsan-integer-wrap-cflags-y)
+
+ifdef CONFIG_CC_IS_CLANG
+stackleak-cflags-$(CONFIG_STACKLEAK) += \
+ -fsanitize-coverage=stack-depth \
+ -fsanitize-coverage-stack-depth-callback-min=$(CONFIG_STACKLEAK_TRACK_MIN_SIZE)
+export STACKLEAK_CFLAGS := $(stackleak-cflags-y)
+ifdef CONFIG_STACKLEAK
+ DISABLE_STACKLEAK := -fno-sanitize-coverage=stack-depth
+endif
+export DISABLE_STACKLEAK
+KBUILD_CFLAGS += $(STACKLEAK_CFLAGS)
+endif
diff --git a/security/Kconfig.hardening b/security/Kconfig.hardening
index edcc489a6805..e86b61e44b33 100644
--- a/security/Kconfig.hardening
+++ b/security/Kconfig.hardening
@@ -158,10 +158,13 @@ config GCC_PLUGIN_STRUCTLEAK_VERBOSE
initialized. Since not all existing initializers are detected
by the plugin, this can produce false positive warnings.
+config CC_HAS_SANCOV_STACK_DEPTH_CALLBACK
+ def_bool $(cc-option,-fsanitize-coverage-stack-depth-callback-min=1)
+
config STACKLEAK
bool "Poison kernel stack before returning from syscalls"
depends on HAVE_ARCH_STACKLEAK
- depends on GCC_PLUGINS
+ depends on GCC_PLUGINS || CC_HAS_SANCOV_STACK_DEPTH_CALLBACK
help
This option makes the kernel erase the kernel stack before
returning from system calls. This has the effect of leaving
--
2.34.1
^ permalink raw reply related [flat|nested] 5+ messages in thread
end of thread, other threads:[~2025-05-02 19:01 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2025-05-02 19:01 [PATCH RFC 0/4] stackleak: Support Clang stack depth tracking Kees Cook
2025-05-02 19:01 ` [PATCH RFC 1/4] stackleak: Rename CONFIG_GCC_PLUGIN_STACKLEAK to CONFIG_STACKLEAK Kees Cook
2025-05-02 19:01 ` [PATCH RFC 2/4] stackleak: Rename stackleak_track_stack to __sanitizer_cov_stack_depth Kees Cook
2025-05-02 19:01 ` [PATCH RFC 3/4] stackleak: Split STACKLEAK_CFLAGS from GCC_PLUGINS_CFLAGS Kees Cook
2025-05-02 19:01 ` [PATCH RFC 4/4] stackleak: Support Clang stack depth tracking Kees Cook
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