* Re: [PATCH 08/14] arm64: simplify access_ok()
From: Mark Rutland @ 2022-02-15 11:24 UTC (permalink / raw)
To: David Laight
Cc: Rich Felker, linux-ia64@vger.kernel.org, linux-sh@vger.kernel.org,
Peter Zijlstra, Linux Kernel Mailing List,
Linux Memory Management List, Guo Ren,
open list:SPARC + UltraSPARC (sparc/sparc64), linux-riscv,
linux-api@vger.kernel.org, Will Deacon, Christoph Hellwig,
linux-arch, open list:S390, Brian Cain,
linux-hexagon@vger.kernel.org, Helge Deller, X86 ML, Russell King,
linux-csky@vger.kernel.org, 'Ard Biesheuvel',
Linus Torvalds, Ingo Molnar, Geert Uytterhoeven,
linux-snps-arc@lists.infradead.org,
open list:TENSILICA XTENSA PORT (xtensa), Arnd Bergmann,
Heiko Carstens, linux-um, Richard Weinberger, linux-m68k,
openrisc@lists.librecores.org, Greentime Hu, Stafford Horne,
Linux ARM, Arnd Bergmann, monstr@monstr.eu, Thomas Bogendoerfer,
Nick Hu, open list:PARISC ARCHITECTURE, Max Filippov,
open list:LINUX FOR POWERPC (32-BIT AND 64-BIT), open list:MIPS,
dinguyen@kernel.org, Eric W. Biederman, alpha, Andrew Morton,
Robin Murphy, David S. Miller
In-Reply-To: <153bb1887f484ed79ce8224845a4b2ea@AcuMS.aculab.com>
On Tue, Feb 15, 2022 at 09:30:41AM +0000, David Laight wrote:
> From: Ard Biesheuvel
> > Sent: 15 February 2022 08:18
> >
> > On Mon, 14 Feb 2022 at 17:37, Arnd Bergmann <arnd@kernel.org> wrote:
> > >
> > > From: Arnd Bergmann <arnd@arndb.de>
> > >
> > > arm64 has an inline asm implementation of access_ok() that is derived from
> > > the 32-bit arm version and optimized for the case that both the limit and
> > > the size are variable. With set_fs() gone, the limit is always constant,
> > > and the size usually is as well, so just using the default implementation
> > > reduces the check into a comparison against a constant that can be
> > > scheduled by the compiler.
> > >
> > > On a defconfig build, this saves over 28KB of .text.
> > >
> > > Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> > > ---
> > > arch/arm64/include/asm/uaccess.h | 28 +++++-----------------------
> > > 1 file changed, 5 insertions(+), 23 deletions(-)
> > >
> > > diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h
> > > index 357f7bd9c981..e8dce0cc5eaa 100644
> > > --- a/arch/arm64/include/asm/uaccess.h
> > > +++ b/arch/arm64/include/asm/uaccess.h
> > > @@ -26,6 +26,8 @@
> > > #include <asm/memory.h>
> > > #include <asm/extable.h>
> > >
> > > +static inline int __access_ok(const void __user *ptr, unsigned long size);
> > > +
> > > /*
> > > * Test whether a block of memory is a valid user space address.
> > > * Returns 1 if the range is valid, 0 otherwise.
> > > @@ -33,10 +35,8 @@
> > > * This is equivalent to the following test:
> > > * (u65)addr + (u65)size <= (u65)TASK_SIZE_MAX
> > > */
> > > -static inline unsigned long __access_ok(const void __user *addr, unsigned long size)
> > > +static inline int access_ok(const void __user *addr, unsigned long size)
> > > {
> > > - unsigned long ret, limit = TASK_SIZE_MAX - 1;
> > > -
> > > /*
> > > * Asynchronous I/O running in a kernel thread does not have the
> > > * TIF_TAGGED_ADDR flag of the process owning the mm, so always untag
> > > @@ -46,27 +46,9 @@ static inline unsigned long __access_ok(const void __user *addr, unsigned long s
> > > (current->flags & PF_KTHREAD || test_thread_flag(TIF_TAGGED_ADDR)))
> > > addr = untagged_addr(addr);
> > >
> > > - __chk_user_ptr(addr);
> > > - asm volatile(
> > > - // A + B <= C + 1 for all A,B,C, in four easy steps:
> > > - // 1: X = A + B; X' = X % 2^64
> > > - " adds %0, %3, %2\n"
> > > - // 2: Set C = 0 if X > 2^64, to guarantee X' > C in step 4
> > > - " csel %1, xzr, %1, hi\n"
> > > - // 3: Set X' = ~0 if X >= 2^64. For X == 2^64, this decrements X'
> > > - // to compensate for the carry flag being set in step 4. For
> > > - // X > 2^64, X' merely has to remain nonzero, which it does.
> > > - " csinv %0, %0, xzr, cc\n"
> > > - // 4: For X < 2^64, this gives us X' - C - 1 <= 0, where the -1
> > > - // comes from the carry in being clear. Otherwise, we are
> > > - // testing X' - C == 0, subject to the previous adjustments.
> > > - " sbcs xzr, %0, %1\n"
> > > - " cset %0, ls\n"
> > > - : "=&r" (ret), "+r" (limit) : "Ir" (size), "0" (addr) : "cc");
> > > -
> > > - return ret;
> > > + return likely(__access_ok(addr, size));
> > > }
> > > -#define __access_ok __access_ok
> > > +#define access_ok access_ok
> > >
> > > #include <asm-generic/access_ok.h>
> > >
> > > --
> > > 2.29.2
> > >
> >
> > With set_fs() out of the picture, wouldn't it be sufficient to check
> > that bit #55 is clear? (the bit that selects between TTBR0 and TTBR1)
> > That would also remove the need to strip the tag from the address.
> >
> > Something like
> >
> > asm goto("tbnz %0, #55, %2 \n"
> > "tbnz %1, #55, %2 \n"
> > :: "r"(addr), "r"(addr + size - 1) :: notok);
> > return 1;
> > notok:
> > return 0;
> >
> > with an additional sanity check on the size which the compiler could
> > eliminate for compile-time constant values.
>
> Is there are reason not to just use:
> size < 1u << 48 && !((addr | (addr + size - 1)) & 1u << 55)
That has a few problems, including being an ABI change for tasks not using the
relaxed tag ABI and not working for 52-bit VAs.
If we really want to relax the tag checking aspect, there are simpler options,
including variations on Ard's approach above.
> Ugg, is arm64 addressing as horrid as it looks - with the 'kernel'
> bit in the middle of the virtual address space?
It's just sign-extension/canonical addressing, except bits [63:56] are
configurable between a few uses, so the achitecture says bit 55 is the one to
look at in all configurations to figure out if an address is high/low (in
addition to checking the remaining bits are canonical).
Thanks,
Mark.
^ permalink raw reply
* Re: [PATCH] powerpc/module_64: use module_init_section instead of patching names
From: Michael Ellerman @ 2022-02-15 11:27 UTC (permalink / raw)
To: Wedson Almeida Filho; +Cc: paulus, linuxppc-dev, linux-kernel
In-Reply-To: <CAMKQLN+Q3asVqP3MZVFZO66CvZVVfGOZn=pMXmiNqZ7t2i55wg@mail.gmail.com>
Wedson Almeida Filho <wedsonaf@google.com> writes:
> Hi Michael,
>
> On Wed, 2 Feb 2022 at 05:53, Wedson Almeida Filho <wedsonaf@google.com> wrote:
>>
>> Without this patch, module init sections are disabled by patching their
>> names in arch-specific code when they're loaded (which prevents code in
>> layout_sections from finding init sections). This patch uses the new
>> arch-specific module_init_section instead.
>>
>> This allows modules that have .init_array sections to have the
>> initialisers properly called (on load, before init). Without this patch,
>> the initialisers are not called because .init_array is renamed to
>> _init_array, and thus isn't found by code in find_module_sections().
>>
>> Signed-off-by: Wedson Almeida Filho <wedsonaf@google.com>
>> ---
>> arch/powerpc/kernel/module_64.c | 11 ++++++-----
>> 1 file changed, 6 insertions(+), 5 deletions(-)
...
>
> Would any additional clarification from my part be helpful here?
Just more patience ;)
> I got an email saying it was under review (and checks passed) but
> nothing appears to have happened since.
I actually put it in next late last week, but the emails got delayed due
to various gremlins.
cheers
^ permalink raw reply
* [PATCH] powerpc/Makefile: Don't pass -mcpu=powerpc64 when building 32-bit
From: Michael Ellerman @ 2022-02-15 11:28 UTC (permalink / raw)
To: linuxppc-dev
When CONFIG_GENERIC_CPU=y (true for all our defconfigs) we pass
-mcpu=powerpc64 to the compiler, even when we're building a 32-bit
kernel.
This happens because we have an ifdef CONFIG_PPC_BOOK3S_64/else block in
the Makefile that was written before 32-bit supported GENERIC_CPU. Prior
to that the else block only applied to 64-bit Book3E.
The GCC man page says -mcpu=powerpc64 "[specifies] a pure ... 64-bit big
endian PowerPC ... architecture machine [type], with an appropriate,
generic processor model assumed for scheduling purposes."
It's unclear how that interacts with -m32, which we are also passing,
although obviously -m32 is taking precedence in some sense, as the
32-bit kernel only contains 32-bit instructions.
This was noticed by inspection, not via any bug reports, but it does
affect code generation. Comparing before/after code generation, there
are some changes to instruction scheduling, and the after case (with
-mcpu=powerpc64 removed) the compiler seems more keen to use r8.
Fix it by making the else case only apply to Book3E 64, which excludes
32-bit.
Fixes: 0e00a8c9fd92 ("powerpc: Allow CPU selection also on PPC32")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---
arch/powerpc/Makefile | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
index ddc5a706760a..1e1ef4352f62 100644
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile
@@ -171,7 +171,7 @@ else
CFLAGS-$(CONFIG_GENERIC_CPU) += $(call cc-option,-mtune=power7,$(call cc-option,-mtune=power5))
CFLAGS-$(CONFIG_GENERIC_CPU) += $(call cc-option,-mcpu=power5,-mcpu=power4)
endif
-else
+else ifdef CONFIG_PPC_BOOK3E_64
CFLAGS-$(CONFIG_GENERIC_CPU) += -mcpu=powerpc64
endif
--
2.34.1
^ permalink raw reply related
* [PATCH v4 11/13] lkdtm: Really write into kernel text in WRITE_KERN
From: Christophe Leroy @ 2022-02-15 12:41 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
Andrew Morton, James E.J. Bottomley, Helge Deller, Arnd Bergmann,
Kees Cook, Greg Kroah-Hartman
Cc: linux-arch, linux-ia64, linux-parisc, linux-kernel, linux-mm,
linuxppc-dev
In-Reply-To: <cover.1644928018.git.christophe.leroy@csgroup.eu>
WRITE_KERN is supposed to overwrite some kernel text, namely
do_overwritten() function.
But at the time being it overwrites do_overwritten() function
descriptor, not function text.
Fix it by dereferencing the function descriptor to obtain
function text pointer. Export dereference_function_descriptor()
for when LKDTM is built as a module.
And make do_overwritten() noinline so that it is really
do_overwritten() which is called by lkdtm_WRITE_KERN().
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
drivers/misc/lkdtm/perms.c | 8 +++++---
kernel/extable.c | 1 +
2 files changed, 6 insertions(+), 3 deletions(-)
diff --git a/drivers/misc/lkdtm/perms.c b/drivers/misc/lkdtm/perms.c
index 60b3b2fe929d..035fcca441f0 100644
--- a/drivers/misc/lkdtm/perms.c
+++ b/drivers/misc/lkdtm/perms.c
@@ -10,6 +10,7 @@
#include <linux/mman.h>
#include <linux/uaccess.h>
#include <asm/cacheflush.h>
+#include <asm/sections.h>
/* Whether or not to fill the target memory area with do_nothing(). */
#define CODE_WRITE true
@@ -37,7 +38,7 @@ static noinline void do_nothing(void)
}
/* Must immediately follow do_nothing for size calculuations to work out. */
-static void do_overwritten(void)
+static noinline void do_overwritten(void)
{
pr_info("do_overwritten wasn't overwritten!\n");
return;
@@ -113,8 +114,9 @@ void lkdtm_WRITE_KERN(void)
size_t size;
volatile unsigned char *ptr;
- size = (unsigned long)do_overwritten - (unsigned long)do_nothing;
- ptr = (unsigned char *)do_overwritten;
+ size = (unsigned long)dereference_function_descriptor(do_overwritten) -
+ (unsigned long)dereference_function_descriptor(do_nothing);
+ ptr = dereference_function_descriptor(do_overwritten);
pr_info("attempting bad %zu byte write at %px\n", size, ptr);
memcpy((void *)ptr, (unsigned char *)do_nothing, size);
diff --git a/kernel/extable.c b/kernel/extable.c
index 394c39b86e38..bda5e9761541 100644
--- a/kernel/extable.c
+++ b/kernel/extable.c
@@ -149,6 +149,7 @@ void *dereference_function_descriptor(void *ptr)
ptr = p;
return ptr;
}
+EXPORT_SYMBOL_GPL(dereference_function_descriptor);
void *dereference_kernel_function_descriptor(void *ptr)
{
--
2.34.1
^ permalink raw reply related
* [PATCH v4 03/13] powerpc: Use 'struct func_desc' instead of 'struct ppc64_opd_entry'
From: Christophe Leroy @ 2022-02-15 12:40 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
Andrew Morton, James E.J. Bottomley, Helge Deller, Arnd Bergmann,
Kees Cook, Greg Kroah-Hartman
Cc: linux-arch, linux-ia64, linux-parisc, linux-kernel, linux-mm,
Nicholas Piggin, linuxppc-dev, Daniel Axtens
In-Reply-To: <cover.1644928018.git.christophe.leroy@csgroup.eu>
'struct ppc64_opd_entry' is somehow redundant with 'struct func_desc',
the later is more correct/complete as it includes the third
field which is unused.
So use 'struct func_desc' instead of 'struct ppc64_opd_entry'
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/include/asm/sections.h | 4 ++--
arch/powerpc/kernel/module_64.c | 10 +++++-----
2 files changed, 7 insertions(+), 7 deletions(-)
diff --git a/arch/powerpc/include/asm/sections.h b/arch/powerpc/include/asm/sections.h
index 38f79e42bf3c..baca39f4c6d3 100644
--- a/arch/powerpc/include/asm/sections.h
+++ b/arch/powerpc/include/asm/sections.h
@@ -61,10 +61,10 @@ static inline int overlaps_kernel_text(unsigned long start, unsigned long end)
#undef dereference_function_descriptor
static inline void *dereference_function_descriptor(void *ptr)
{
- struct ppc64_opd_entry *desc = ptr;
+ struct func_desc *desc = ptr;
void *p;
- if (!get_kernel_nofault(p, (void *)&desc->funcaddr))
+ if (!get_kernel_nofault(p, (void *)&desc->addr))
ptr = p;
return ptr;
}
diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c
index 6a45e6ddbe58..46e8eeb7c432 100644
--- a/arch/powerpc/kernel/module_64.c
+++ b/arch/powerpc/kernel/module_64.c
@@ -64,19 +64,19 @@ static unsigned int local_entry_offset(const Elf64_Sym *sym)
#else
/* An address is address of the OPD entry, which contains address of fn. */
-typedef struct ppc64_opd_entry func_desc_t;
+typedef struct func_desc func_desc_t;
static func_desc_t func_desc(unsigned long addr)
{
- return *(struct ppc64_opd_entry *)addr;
+ return *(struct func_desc *)addr;
}
static unsigned long func_addr(unsigned long addr)
{
- return func_desc(addr).funcaddr;
+ return func_desc(addr).addr;
}
static unsigned long stub_func_addr(func_desc_t func)
{
- return func.funcaddr;
+ return func.addr;
}
static unsigned int local_entry_offset(const Elf64_Sym *sym)
{
@@ -187,7 +187,7 @@ static int relacmp(const void *_x, const void *_y)
static unsigned long get_stubs_size(const Elf64_Ehdr *hdr,
const Elf64_Shdr *sechdrs)
{
- /* One extra reloc so it's always 0-funcaddr terminated */
+ /* One extra reloc so it's always 0-addr terminated */
unsigned long relocs = 1;
unsigned i;
--
2.34.1
^ permalink raw reply related
* [PATCH v4 01/13] powerpc: Fix 'sparse' checking on PPC64le
From: Christophe Leroy @ 2022-02-15 12:40 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
Andrew Morton, James E.J. Bottomley, Helge Deller, Arnd Bergmann,
Kees Cook, Greg Kroah-Hartman
Cc: linux-arch, linux-ia64, linux-parisc, linux-kernel, linux-mm,
linuxppc-dev
In-Reply-To: <cover.1644928018.git.christophe.leroy@csgroup.eu>
'sparse' is architecture agnostic and knows nothing about ELF ABI
version.
Just like it gets arch and powerpc type and endian from Makefile,
it also need to get _CALL_ELF from there, otherwise it won't set
PPC64_ELF_ABI_v2 macro for PPC64le and won't check the correct code.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/Makefile | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
index ddc5a706760a..4d4d8175f4a1 100644
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile
@@ -213,7 +213,7 @@ CHECKFLAGS += -m$(BITS) -D__powerpc__ -D__powerpc$(BITS)__
ifdef CONFIG_CPU_BIG_ENDIAN
CHECKFLAGS += -D__BIG_ENDIAN__
else
-CHECKFLAGS += -D__LITTLE_ENDIAN__
+CHECKFLAGS += -D__LITTLE_ENDIAN__ -D_CALL_ELF=2
endif
ifdef CONFIG_476FPE_ERR46
--
2.34.1
^ permalink raw reply related
* [PATCH v4 12/13] lkdtm: Fix execute_[user]_location()
From: Christophe Leroy @ 2022-02-15 12:41 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
Andrew Morton, James E.J. Bottomley, Helge Deller, Arnd Bergmann,
Kees Cook, Greg Kroah-Hartman
Cc: linux-arch, linux-ia64, linux-parisc, linux-kernel, linux-mm,
linuxppc-dev
In-Reply-To: <cover.1644928018.git.christophe.leroy@csgroup.eu>
execute_location() and execute_user_location() intent
to copy do_nothing() text and execute it at a new location.
However, at the time being it doesn't copy do_nothing() function
but do_nothing() function descriptor which still points to the
original text. So at the end it still executes do_nothing() at
its original location allthough using a copied function descriptor.
So, fix that by really copying do_nothing() text and build a new
function descriptor by copying do_nothing() function descriptor and
updating the target address with the new location.
Also fix the displayed addresses by dereferencing do_nothing()
function descriptor.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Kees Cook <keescook@chromium.org>
---
drivers/misc/lkdtm/perms.c | 37 ++++++++++++++++++++++++++++---------
1 file changed, 28 insertions(+), 9 deletions(-)
diff --git a/drivers/misc/lkdtm/perms.c b/drivers/misc/lkdtm/perms.c
index 035fcca441f0..1cf24c4a79e9 100644
--- a/drivers/misc/lkdtm/perms.c
+++ b/drivers/misc/lkdtm/perms.c
@@ -44,19 +44,34 @@ static noinline void do_overwritten(void)
return;
}
+static void *setup_function_descriptor(func_desc_t *fdesc, void *dst)
+{
+ if (!have_function_descriptors())
+ return dst;
+
+ memcpy(fdesc, do_nothing, sizeof(*fdesc));
+ fdesc->addr = (unsigned long)dst;
+ barrier();
+
+ return fdesc;
+}
+
static noinline void execute_location(void *dst, bool write)
{
- void (*func)(void) = dst;
+ void (*func)(void);
+ func_desc_t fdesc;
+ void *do_nothing_text = dereference_function_descriptor(do_nothing);
- pr_info("attempting ok execution at %px\n", do_nothing);
+ pr_info("attempting ok execution at %px\n", do_nothing_text);
do_nothing();
if (write == CODE_WRITE) {
- memcpy(dst, do_nothing, EXEC_SIZE);
+ memcpy(dst, do_nothing_text, EXEC_SIZE);
flush_icache_range((unsigned long)dst,
(unsigned long)dst + EXEC_SIZE);
}
- pr_info("attempting bad execution at %px\n", func);
+ pr_info("attempting bad execution at %px\n", dst);
+ func = setup_function_descriptor(&fdesc, dst);
func();
pr_err("FAIL: func returned\n");
}
@@ -66,16 +81,19 @@ static void execute_user_location(void *dst)
int copied;
/* Intentionally crossing kernel/user memory boundary. */
- void (*func)(void) = dst;
+ void (*func)(void);
+ func_desc_t fdesc;
+ void *do_nothing_text = dereference_function_descriptor(do_nothing);
- pr_info("attempting ok execution at %px\n", do_nothing);
+ pr_info("attempting ok execution at %px\n", do_nothing_text);
do_nothing();
- copied = access_process_vm(current, (unsigned long)dst, do_nothing,
+ copied = access_process_vm(current, (unsigned long)dst, do_nothing_text,
EXEC_SIZE, FOLL_WRITE);
if (copied < EXEC_SIZE)
return;
- pr_info("attempting bad execution at %px\n", func);
+ pr_info("attempting bad execution at %px\n", dst);
+ func = setup_function_descriptor(&fdesc, dst);
func();
pr_err("FAIL: func returned\n");
}
@@ -153,7 +171,8 @@ void lkdtm_EXEC_VMALLOC(void)
void lkdtm_EXEC_RODATA(void)
{
- execute_location(lkdtm_rodata_do_nothing, CODE_AS_IS);
+ execute_location(dereference_function_descriptor(lkdtm_rodata_do_nothing),
+ CODE_AS_IS);
}
void lkdtm_EXEC_USERSPACE(void)
--
2.34.1
^ permalink raw reply related
* [PATCH v4 08/13] asm-generic: Define 'func_desc_t' to commonly describe function descriptors
From: Christophe Leroy @ 2022-02-15 12:41 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
Andrew Morton, James E.J. Bottomley, Helge Deller, Arnd Bergmann,
Kees Cook, Greg Kroah-Hartman
Cc: linux-arch, linux-ia64, linux-parisc, linux-kernel, linux-mm,
linuxppc-dev
In-Reply-To: <cover.1644928018.git.christophe.leroy@csgroup.eu>
We have three architectures using function descriptors, each with its
own type and name.
Add a common typedef that can be used in generic code.
Also add a stub typedef for architecture without function descriptors,
to avoid a forest of #ifdefs.
It replaces the similar 'func_desc_t' previously defined in
arch/powerpc/kernel/module_64.c
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Helge Deller <deller@gmx.de>
---
arch/ia64/include/asm/sections.h | 3 +++
arch/parisc/include/asm/sections.h | 5 +++++
arch/powerpc/include/asm/sections.h | 4 ++++
arch/powerpc/kernel/module_64.c | 8 --------
include/asm-generic/sections.h | 5 +++++
5 files changed, 17 insertions(+), 8 deletions(-)
diff --git a/arch/ia64/include/asm/sections.h b/arch/ia64/include/asm/sections.h
index 2460d365a057..3abe0562b01a 100644
--- a/arch/ia64/include/asm/sections.h
+++ b/arch/ia64/include/asm/sections.h
@@ -9,6 +9,9 @@
#include <linux/elf.h>
#include <linux/uaccess.h>
+
+typedef struct fdesc func_desc_t;
+
#include <asm-generic/sections.h>
extern char __phys_per_cpu_start[];
diff --git a/arch/parisc/include/asm/sections.h b/arch/parisc/include/asm/sections.h
index c8092e4d94de..ace1d4047a0b 100644
--- a/arch/parisc/include/asm/sections.h
+++ b/arch/parisc/include/asm/sections.h
@@ -2,6 +2,11 @@
#ifndef _PARISC_SECTIONS_H
#define _PARISC_SECTIONS_H
+#ifdef CONFIG_HAVE_FUNCTION_DESCRIPTORS
+#include <asm/elf.h>
+typedef Elf64_Fdesc func_desc_t;
+#endif
+
/* nothing to see, move along */
#include <asm-generic/sections.h>
diff --git a/arch/powerpc/include/asm/sections.h b/arch/powerpc/include/asm/sections.h
index 7728a7a146c3..fddfb3937868 100644
--- a/arch/powerpc/include/asm/sections.h
+++ b/arch/powerpc/include/asm/sections.h
@@ -6,6 +6,10 @@
#include <linux/elf.h>
#include <linux/uaccess.h>
+#ifdef CONFIG_HAVE_FUNCTION_DESCRIPTORS
+typedef struct func_desc func_desc_t;
+#endif
+
#include <asm-generic/sections.h>
extern char __head_end[];
diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c
index ff93ef4cb5a2..9abc0e783e36 100644
--- a/arch/powerpc/kernel/module_64.c
+++ b/arch/powerpc/kernel/module_64.c
@@ -32,11 +32,6 @@
#ifdef PPC64_ELF_ABI_v2
-/* An address is simply the address of the function. */
-typedef struct {
- unsigned long addr;
-} func_desc_t;
-
static func_desc_t func_desc(unsigned long addr)
{
func_desc_t desc = {
@@ -61,9 +56,6 @@ static unsigned int local_entry_offset(const Elf64_Sym *sym)
}
#else
-/* An address is address of the OPD entry, which contains address of fn. */
-typedef struct func_desc func_desc_t;
-
static func_desc_t func_desc(unsigned long addr)
{
return *(struct func_desc *)addr;
diff --git a/include/asm-generic/sections.h b/include/asm-generic/sections.h
index 3ef83e1aebee..bbf97502470c 100644
--- a/include/asm-generic/sections.h
+++ b/include/asm-generic/sections.h
@@ -63,6 +63,11 @@ extern __visible const void __nosave_begin, __nosave_end;
#else
#define dereference_function_descriptor(p) ((void *)(p))
#define dereference_kernel_function_descriptor(p) ((void *)(p))
+
+/* An address is simply the address of the function. */
+typedef struct {
+ unsigned long addr;
+} func_desc_t;
#endif
static inline bool have_function_descriptors(void)
--
2.34.1
^ permalink raw reply related
* [PATCH v4 10/13] lkdtm: Force do_nothing() out of line
From: Christophe Leroy @ 2022-02-15 12:41 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
Andrew Morton, James E.J. Bottomley, Helge Deller, Arnd Bergmann,
Kees Cook, Greg Kroah-Hartman
Cc: linux-arch, linux-ia64, linux-parisc, linux-kernel, linux-mm,
linuxppc-dev
In-Reply-To: <cover.1644928018.git.christophe.leroy@csgroup.eu>
LKDTM tests display that the run do_nothing() at a given
address, but in reality do_nothing() is inlined into the
caller.
Force it out of line so that it really runs text at the
displayed address.
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
drivers/misc/lkdtm/perms.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/misc/lkdtm/perms.c b/drivers/misc/lkdtm/perms.c
index 2dede2ef658f..60b3b2fe929d 100644
--- a/drivers/misc/lkdtm/perms.c
+++ b/drivers/misc/lkdtm/perms.c
@@ -21,7 +21,7 @@
/* This is non-const, so it will end up in the .data section. */
static u8 data_area[EXEC_SIZE];
-/* This is cost, so it will end up in the .rodata section. */
+/* This is const, so it will end up in the .rodata section. */
static const unsigned long rodata = 0xAA55AA55;
/* This is marked __ro_after_init, so it should ultimately be .rodata. */
@@ -31,7 +31,7 @@ static unsigned long ro_after_init __ro_after_init = 0x55AA5500;
* This just returns to the caller. It is designed to be copied into
* non-executable memory regions.
*/
-static void do_nothing(void)
+static noinline void do_nothing(void)
{
return;
}
--
2.34.1
^ permalink raw reply related
* [PATCH v4 06/13] ia64: Rename 'ip' to 'addr' in 'struct fdesc'
From: Christophe Leroy @ 2022-02-15 12:41 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
Andrew Morton, James E.J. Bottomley, Helge Deller, Arnd Bergmann,
Kees Cook, Greg Kroah-Hartman
Cc: linux-arch, linux-ia64, linux-parisc, linux-kernel, linux-mm,
linuxppc-dev
In-Reply-To: <cover.1644928018.git.christophe.leroy@csgroup.eu>
There are three architectures with function descriptors, try to
have common names for the address they contain in order to
refactor some functions into generic functions later.
powerpc has 'entry'
ia64 has 'ip'
parisc has 'addr'
Vote for 'addr' and update 'struct fdesc' accordingly.
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/ia64/include/asm/elf.h | 2 +-
arch/ia64/include/asm/sections.h | 2 +-
arch/ia64/kernel/module.c | 6 +++---
3 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/arch/ia64/include/asm/elf.h b/arch/ia64/include/asm/elf.h
index 6629301a2620..2ef5f9966ad1 100644
--- a/arch/ia64/include/asm/elf.h
+++ b/arch/ia64/include/asm/elf.h
@@ -226,7 +226,7 @@ struct got_entry {
* Layout of the Function Descriptor
*/
struct fdesc {
- uint64_t ip;
+ uint64_t addr;
uint64_t gp;
};
diff --git a/arch/ia64/include/asm/sections.h b/arch/ia64/include/asm/sections.h
index 3a033d2008b3..35f24e52149a 100644
--- a/arch/ia64/include/asm/sections.h
+++ b/arch/ia64/include/asm/sections.h
@@ -35,7 +35,7 @@ static inline void *dereference_function_descriptor(void *ptr)
struct fdesc *desc = ptr;
void *p;
- if (!get_kernel_nofault(p, (void *)&desc->ip))
+ if (!get_kernel_nofault(p, (void *)&desc->addr))
ptr = p;
return ptr;
}
diff --git a/arch/ia64/kernel/module.c b/arch/ia64/kernel/module.c
index 360f36b0eb3f..8f62cf97f691 100644
--- a/arch/ia64/kernel/module.c
+++ b/arch/ia64/kernel/module.c
@@ -602,15 +602,15 @@ get_fdesc (struct module *mod, uint64_t value, int *okp)
return value;
/* Look for existing function descriptor. */
- while (fdesc->ip) {
- if (fdesc->ip == value)
+ while (fdesc->addr) {
+ if (fdesc->addr == value)
return (uint64_t)fdesc;
if ((uint64_t) ++fdesc >= mod->arch.opd->sh_addr + mod->arch.opd->sh_size)
BUG();
}
/* Create new one */
- fdesc->ip = value;
+ fdesc->addr = value;
fdesc->gp = mod->arch.gp;
return (uint64_t) fdesc;
}
--
2.34.1
^ permalink raw reply related
* [PATCH v4 13/13] lkdtm: Add a test for function descriptors protection
From: Christophe Leroy @ 2022-02-15 12:41 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
Andrew Morton, James E.J. Bottomley, Helge Deller, Arnd Bergmann,
Kees Cook, Greg Kroah-Hartman
Cc: linux-arch, linux-ia64, linux-parisc, linux-kernel, linux-mm,
linuxppc-dev
In-Reply-To: <cover.1644928018.git.christophe.leroy@csgroup.eu>
Add WRITE_OPD to check that you can't modify function
descriptors.
Gives the following result when function descriptors are
not protected:
lkdtm: Performing direct entry WRITE_OPD
lkdtm: attempting bad 16 bytes write at c00000000269b358
lkdtm: FAIL: survived bad write
lkdtm: do_nothing was hijacked!
Looks like a standard compiler barrier() is not enough to force
GCC to use the modified function descriptor. Had to add a fake empty
inline assembly to force GCC to reload the function descriptor.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Kees Cook <keescook@chromium.org>
---
drivers/misc/lkdtm/core.c | 1 +
drivers/misc/lkdtm/lkdtm.h | 1 +
drivers/misc/lkdtm/perms.c | 22 ++++++++++++++++++++++
tools/testing/selftests/lkdtm/tests.txt | 1 +
4 files changed, 25 insertions(+)
diff --git a/drivers/misc/lkdtm/core.c b/drivers/misc/lkdtm/core.c
index f69b964b9952..e2228b6fc09b 100644
--- a/drivers/misc/lkdtm/core.c
+++ b/drivers/misc/lkdtm/core.c
@@ -149,6 +149,7 @@ static const struct crashtype crashtypes[] = {
CRASHTYPE(WRITE_RO),
CRASHTYPE(WRITE_RO_AFTER_INIT),
CRASHTYPE(WRITE_KERN),
+ CRASHTYPE(WRITE_OPD),
CRASHTYPE(REFCOUNT_INC_OVERFLOW),
CRASHTYPE(REFCOUNT_ADD_OVERFLOW),
CRASHTYPE(REFCOUNT_INC_NOT_ZERO_OVERFLOW),
diff --git a/drivers/misc/lkdtm/lkdtm.h b/drivers/misc/lkdtm/lkdtm.h
index d6137c70ebbe..305fc2ec3f25 100644
--- a/drivers/misc/lkdtm/lkdtm.h
+++ b/drivers/misc/lkdtm/lkdtm.h
@@ -106,6 +106,7 @@ void __init lkdtm_perms_init(void);
void lkdtm_WRITE_RO(void);
void lkdtm_WRITE_RO_AFTER_INIT(void);
void lkdtm_WRITE_KERN(void);
+void lkdtm_WRITE_OPD(void);
void lkdtm_EXEC_DATA(void);
void lkdtm_EXEC_STACK(void);
void lkdtm_EXEC_KMALLOC(void);
diff --git a/drivers/misc/lkdtm/perms.c b/drivers/misc/lkdtm/perms.c
index 1cf24c4a79e9..2c6aba3ff32b 100644
--- a/drivers/misc/lkdtm/perms.c
+++ b/drivers/misc/lkdtm/perms.c
@@ -44,6 +44,11 @@ static noinline void do_overwritten(void)
return;
}
+static noinline void do_almost_nothing(void)
+{
+ pr_info("do_nothing was hijacked!\n");
+}
+
static void *setup_function_descriptor(func_desc_t *fdesc, void *dst)
{
if (!have_function_descriptors())
@@ -144,6 +149,23 @@ void lkdtm_WRITE_KERN(void)
do_overwritten();
}
+void lkdtm_WRITE_OPD(void)
+{
+ size_t size = sizeof(func_desc_t);
+ void (*func)(void) = do_nothing;
+
+ if (!have_function_descriptors()) {
+ pr_info("XFAIL: Platform doesn't use function descriptors.\n");
+ return;
+ }
+ pr_info("attempting bad %zu bytes write at %px\n", size, do_nothing);
+ memcpy(do_nothing, do_almost_nothing, size);
+ pr_err("FAIL: survived bad write\n");
+
+ asm("" : "=m"(func));
+ func();
+}
+
void lkdtm_EXEC_DATA(void)
{
execute_location(data_area, CODE_WRITE);
diff --git a/tools/testing/selftests/lkdtm/tests.txt b/tools/testing/selftests/lkdtm/tests.txt
index 6b36b7f5dcf9..243c781f0780 100644
--- a/tools/testing/selftests/lkdtm/tests.txt
+++ b/tools/testing/selftests/lkdtm/tests.txt
@@ -44,6 +44,7 @@ ACCESS_NULL
WRITE_RO
WRITE_RO_AFTER_INIT
WRITE_KERN
+WRITE_OPD
REFCOUNT_INC_OVERFLOW
REFCOUNT_ADD_OVERFLOW
REFCOUNT_INC_NOT_ZERO_OVERFLOW
--
2.34.1
^ permalink raw reply related
* [PATCH v4 07/13] asm-generic: Define CONFIG_HAVE_FUNCTION_DESCRIPTORS
From: Christophe Leroy @ 2022-02-15 12:41 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
Andrew Morton, James E.J. Bottomley, Helge Deller, Arnd Bergmann,
Kees Cook, Greg Kroah-Hartman
Cc: linux-arch, linux-ia64, linux-parisc, linux-kernel, linux-mm,
Nicholas Piggin, linuxppc-dev
In-Reply-To: <cover.1644928018.git.christophe.leroy@csgroup.eu>
Replace HAVE_DEREFERENCE_FUNCTION_DESCRIPTOR by a config option
named CONFIG_HAVE_FUNCTION_DESCRIPTORS and use it instead of
'dereference_function_descriptor' macro to know whether an
arch has function descriptors.
To limit churn in one of the following patches, use
an #ifdef/#else construct with empty first part
instead of an #ifndef in asm-generic/sections.h
On powerpc, make sure the config option matches the ABI used
by the compiler with a BUILD_BUG_ON() and add missing _CALL_ELF=2
when calling 'sparse' so that sparse sees the same piece of
code as GCC.
And include a helper to check whether an arch has function
descriptors or not : have_function_descriptors()
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Helge Deller <deller@gmx.de>
---
arch/Kconfig | 3 +++
arch/ia64/Kconfig | 1 +
arch/ia64/include/asm/sections.h | 2 --
arch/parisc/Kconfig | 1 +
arch/parisc/include/asm/sections.h | 2 --
arch/powerpc/Kconfig | 1 +
arch/powerpc/include/asm/sections.h | 2 --
arch/powerpc/kernel/ptrace/ptrace.c | 6 ++++++
include/asm-generic/sections.h | 8 +++++++-
include/linux/kallsyms.h | 2 +-
10 files changed, 20 insertions(+), 8 deletions(-)
diff --git a/arch/Kconfig b/arch/Kconfig
index 678a80713b21..fe24174cb63c 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -205,6 +205,9 @@ config HAVE_FUNCTION_ERROR_INJECTION
config HAVE_NMI
bool
+config HAVE_FUNCTION_DESCRIPTORS
+ bool
+
config TRACE_IRQFLAGS_SUPPORT
bool
diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index a7e01573abd8..da85c3b23b16 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -35,6 +35,7 @@ config IA64
select HAVE_SETUP_PER_CPU_AREA
select TTY
select HAVE_ARCH_TRACEHOOK
+ select HAVE_FUNCTION_DESCRIPTORS
select HAVE_VIRT_CPU_ACCOUNTING
select HUGETLB_PAGE_SIZE_VARIABLE if HUGETLB_PAGE
select VIRT_TO_BUS
diff --git a/arch/ia64/include/asm/sections.h b/arch/ia64/include/asm/sections.h
index 35f24e52149a..2460d365a057 100644
--- a/arch/ia64/include/asm/sections.h
+++ b/arch/ia64/include/asm/sections.h
@@ -27,8 +27,6 @@ extern char __start_gate_brl_fsys_bubble_down_patchlist[], __end_gate_brl_fsys_b
extern char __start_unwind[], __end_unwind[];
extern char __start_ivt_text[], __end_ivt_text[];
-#define HAVE_DEREFERENCE_FUNCTION_DESCRIPTOR 1
-
#undef dereference_function_descriptor
static inline void *dereference_function_descriptor(void *ptr)
{
diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig
index 43c1c880def6..82e7ab1a9764 100644
--- a/arch/parisc/Kconfig
+++ b/arch/parisc/Kconfig
@@ -69,6 +69,7 @@ config PARISC
select HAVE_DYNAMIC_FTRACE_WITH_REGS
select HAVE_SOFTIRQ_ON_OWN_STACK if IRQSTACKS
select TRACE_IRQFLAGS_SUPPORT
+ select HAVE_FUNCTION_DESCRIPTORS if 64BIT
help
The PA-RISC microprocessor is designed by Hewlett-Packard and used
diff --git a/arch/parisc/include/asm/sections.h b/arch/parisc/include/asm/sections.h
index bb52aea0cb21..c8092e4d94de 100644
--- a/arch/parisc/include/asm/sections.h
+++ b/arch/parisc/include/asm/sections.h
@@ -9,8 +9,6 @@ extern char __alt_instructions[], __alt_instructions_end[];
#ifdef CONFIG_64BIT
-#define HAVE_DEREFERENCE_FUNCTION_DESCRIPTOR 1
-
#undef dereference_function_descriptor
void *dereference_function_descriptor(void *);
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 28e4047e99e8..23ce71367467 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -207,6 +207,7 @@ config PPC
select HAVE_EFFICIENT_UNALIGNED_ACCESS if !(CPU_LITTLE_ENDIAN && POWER7_CPU)
select HAVE_FAST_GUP
select HAVE_FTRACE_MCOUNT_RECORD
+ select HAVE_FUNCTION_DESCRIPTORS if PPC64 && !CPU_LITTLE_ENDIAN
select HAVE_FUNCTION_ERROR_INJECTION
select HAVE_FUNCTION_GRAPH_TRACER
select HAVE_FUNCTION_TRACER
diff --git a/arch/powerpc/include/asm/sections.h b/arch/powerpc/include/asm/sections.h
index baca39f4c6d3..7728a7a146c3 100644
--- a/arch/powerpc/include/asm/sections.h
+++ b/arch/powerpc/include/asm/sections.h
@@ -56,8 +56,6 @@ static inline int overlaps_kernel_text(unsigned long start, unsigned long end)
#ifdef PPC64_ELF_ABI_v1
-#define HAVE_DEREFERENCE_FUNCTION_DESCRIPTOR 1
-
#undef dereference_function_descriptor
static inline void *dereference_function_descriptor(void *ptr)
{
diff --git a/arch/powerpc/kernel/ptrace/ptrace.c b/arch/powerpc/kernel/ptrace/ptrace.c
index c43f77e2ac31..1212a812a7ab 100644
--- a/arch/powerpc/kernel/ptrace/ptrace.c
+++ b/arch/powerpc/kernel/ptrace/ptrace.c
@@ -445,4 +445,10 @@ void __init pt_regs_check(void)
* real registers.
*/
BUILD_BUG_ON(PT_DSCR < sizeof(struct user_pt_regs) / sizeof(unsigned long));
+
+#ifdef PPC64_ELF_ABI_v1
+ BUILD_BUG_ON(!IS_ENABLED(CONFIG_HAVE_FUNCTION_DESCRIPTORS));
+#else
+ BUILD_BUG_ON(IS_ENABLED(CONFIG_HAVE_FUNCTION_DESCRIPTORS));
+#endif
}
diff --git a/include/asm-generic/sections.h b/include/asm-generic/sections.h
index 690f741764e1..3ef83e1aebee 100644
--- a/include/asm-generic/sections.h
+++ b/include/asm-generic/sections.h
@@ -59,11 +59,17 @@ extern char __noinstr_text_start[], __noinstr_text_end[];
extern __visible const void __nosave_begin, __nosave_end;
/* Function descriptor handling (if any). Override in asm/sections.h */
-#ifndef dereference_function_descriptor
+#ifdef CONFIG_HAVE_FUNCTION_DESCRIPTORS
+#else
#define dereference_function_descriptor(p) ((void *)(p))
#define dereference_kernel_function_descriptor(p) ((void *)(p))
#endif
+static inline bool have_function_descriptors(void)
+{
+ return IS_ENABLED(CONFIG_HAVE_FUNCTION_DESCRIPTORS);
+}
+
/**
* memory_contains - checks if an object is contained within a memory region
* @begin: virtual address of the beginning of the memory region
diff --git a/include/linux/kallsyms.h b/include/linux/kallsyms.h
index 4176c7eca7b5..ce1bd2fbf23e 100644
--- a/include/linux/kallsyms.h
+++ b/include/linux/kallsyms.h
@@ -48,7 +48,7 @@ static inline int is_ksym_addr(unsigned long addr)
static inline void *dereference_symbol_descriptor(void *ptr)
{
-#ifdef HAVE_DEREFERENCE_FUNCTION_DESCRIPTOR
+#ifdef CONFIG_HAVE_FUNCTION_DESCRIPTORS
struct module *mod;
ptr = dereference_kernel_function_descriptor(ptr);
--
2.34.1
^ permalink raw reply related
* [PATCH v4 00/13] Fix LKDTM for PPC64/IA64/PARISC v4
From: Christophe Leroy @ 2022-02-15 12:40 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
Andrew Morton, James E.J. Bottomley, Helge Deller, Arnd Bergmann,
Kees Cook, Greg Kroah-Hartman
Cc: linux-arch, linux-ia64, linux-parisc, linux-kernel, linux-mm,
linuxppc-dev
PPC64/IA64/PARISC have function descriptors. LKDTM doesn't work
on those three architectures because LKDTM messes up function
descriptors with functions.
This series does some cleanup in the three architectures and
refactors function descriptors so that it can then easily use it
in a generic way in LKDTM.
Changes in v4:
- Added patch 1 which Fixes 'sparse' for powerpc64le after wrong report on previous series, refer https://github.com/ruscur/linux-ci/actions/runs/1351427671
- Exported dereference_function_descriptor() to modules
- Addressed other received comments
- Rebased on latest powerpc/next (5a72345e6a78120368fcc841b570331b6c5a50da)
Changes in v3:
- Addressed received comments
- Swapped some of the powerpc patches to keep func_descr_t renamed as struct func_desc and remove 'struct ppc64_opd_entry'
- Changed HAVE_FUNCTION_DESCRIPTORS macro to a config item CONFIG_HAVE_FUNCTION_DESCRIPTORS
- Dropped patch 11 ("Fix lkdtm_EXEC_RODATA()")
Changes in v2:
- Addressed received comments
- Moved dereference_[kernel]_function_descriptor() out of line
- Added patches to remove func_descr_t and func_desc_t in powerpc
- Using func_desc_t instead of funct_descr_t
- Renamed HAVE_DEREFERENCE_FUNCTION_DESCRIPTOR to HAVE_FUNCTION_DESCRIPTORS
- Added a new lkdtm test to check protection of function descriptors
Christophe Leroy (13):
powerpc: Fix 'sparse' checking on PPC64le
powerpc: Move and rename func_descr_t
powerpc: Use 'struct func_desc' instead of 'struct ppc64_opd_entry'
powerpc: Remove 'struct ppc64_opd_entry'
powerpc: Prepare func_desc_t for refactorisation
ia64: Rename 'ip' to 'addr' in 'struct fdesc'
asm-generic: Define CONFIG_HAVE_FUNCTION_DESCRIPTORS
asm-generic: Define 'func_desc_t' to commonly describe function
descriptors
asm-generic: Refactor dereference_[kernel]_function_descriptor()
lkdtm: Force do_nothing() out of line
lkdtm: Really write into kernel text in WRITE_KERN
lkdtm: Fix execute_[user]_location()
lkdtm: Add a test for function descriptors protection
arch/Kconfig | 3 +
arch/ia64/Kconfig | 1 +
arch/ia64/include/asm/elf.h | 2 +-
arch/ia64/include/asm/sections.h | 24 +-------
arch/ia64/kernel/module.c | 6 +-
arch/parisc/Kconfig | 1 +
arch/parisc/include/asm/sections.h | 16 ++----
arch/parisc/kernel/process.c | 21 -------
arch/powerpc/Kconfig | 1 +
arch/powerpc/Makefile | 2 +-
arch/powerpc/include/asm/code-patching.h | 2 +-
arch/powerpc/include/asm/elf.h | 6 ++
arch/powerpc/include/asm/sections.h | 29 ++--------
arch/powerpc/include/asm/types.h | 6 --
arch/powerpc/include/uapi/asm/elf.h | 8 ---
arch/powerpc/kernel/module_64.c | 42 ++++++--------
arch/powerpc/kernel/ptrace/ptrace.c | 6 ++
arch/powerpc/kernel/signal_64.c | 8 +--
drivers/misc/lkdtm/core.c | 1 +
drivers/misc/lkdtm/lkdtm.h | 1 +
drivers/misc/lkdtm/perms.c | 71 +++++++++++++++++++-----
include/asm-generic/sections.h | 15 ++++-
include/linux/kallsyms.h | 2 +-
kernel/extable.c | 24 +++++++-
tools/testing/selftests/lkdtm/tests.txt | 1 +
25 files changed, 155 insertions(+), 144 deletions(-)
--
2.34.1
^ permalink raw reply
* [PATCH v4 09/13] asm-generic: Refactor dereference_[kernel]_function_descriptor()
From: Christophe Leroy @ 2022-02-15 12:41 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
Andrew Morton, James E.J. Bottomley, Helge Deller, Arnd Bergmann,
Kees Cook, Greg Kroah-Hartman
Cc: linux-arch, linux-ia64, linux-parisc, linux-kernel, linux-mm,
linuxppc-dev
In-Reply-To: <cover.1644928018.git.christophe.leroy@csgroup.eu>
dereference_function_descriptor() and
dereference_kernel_function_descriptor() are identical on the
three architectures implementing them.
Make them common and put them out-of-line in kernel/extable.c
which is one of the users and has similar type of functions.
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Helge Deller <deller@gmx.de>
---
arch/ia64/include/asm/sections.h | 19 -------------------
arch/parisc/include/asm/sections.h | 9 ---------
arch/parisc/kernel/process.c | 21 ---------------------
arch/powerpc/include/asm/sections.h | 23 -----------------------
include/asm-generic/sections.h | 2 ++
kernel/extable.c | 23 ++++++++++++++++++++++-
6 files changed, 24 insertions(+), 73 deletions(-)
diff --git a/arch/ia64/include/asm/sections.h b/arch/ia64/include/asm/sections.h
index 3abe0562b01a..8e0875cf6071 100644
--- a/arch/ia64/include/asm/sections.h
+++ b/arch/ia64/include/asm/sections.h
@@ -30,23 +30,4 @@ extern char __start_gate_brl_fsys_bubble_down_patchlist[], __end_gate_brl_fsys_b
extern char __start_unwind[], __end_unwind[];
extern char __start_ivt_text[], __end_ivt_text[];
-#undef dereference_function_descriptor
-static inline void *dereference_function_descriptor(void *ptr)
-{
- struct fdesc *desc = ptr;
- void *p;
-
- if (!get_kernel_nofault(p, (void *)&desc->addr))
- ptr = p;
- return ptr;
-}
-
-#undef dereference_kernel_function_descriptor
-static inline void *dereference_kernel_function_descriptor(void *ptr)
-{
- if (ptr < (void *)__start_opd || ptr >= (void *)__end_opd)
- return ptr;
- return dereference_function_descriptor(ptr);
-}
-
#endif /* _ASM_IA64_SECTIONS_H */
diff --git a/arch/parisc/include/asm/sections.h b/arch/parisc/include/asm/sections.h
index ace1d4047a0b..33df42b5cc6d 100644
--- a/arch/parisc/include/asm/sections.h
+++ b/arch/parisc/include/asm/sections.h
@@ -12,13 +12,4 @@ typedef Elf64_Fdesc func_desc_t;
extern char __alt_instructions[], __alt_instructions_end[];
-#ifdef CONFIG_64BIT
-
-#undef dereference_function_descriptor
-void *dereference_function_descriptor(void *);
-
-#undef dereference_kernel_function_descriptor
-void *dereference_kernel_function_descriptor(void *);
-#endif
-
#endif
diff --git a/arch/parisc/kernel/process.c b/arch/parisc/kernel/process.c
index ea3d83b6fb62..2030c77592d3 100644
--- a/arch/parisc/kernel/process.c
+++ b/arch/parisc/kernel/process.c
@@ -263,27 +263,6 @@ __get_wchan(struct task_struct *p)
return 0;
}
-#ifdef CONFIG_64BIT
-void *dereference_function_descriptor(void *ptr)
-{
- Elf64_Fdesc *desc = ptr;
- void *p;
-
- if (!get_kernel_nofault(p, (void *)&desc->addr))
- ptr = p;
- return ptr;
-}
-
-void *dereference_kernel_function_descriptor(void *ptr)
-{
- if (ptr < (void *)__start_opd ||
- ptr >= (void *)__end_opd)
- return ptr;
-
- return dereference_function_descriptor(ptr);
-}
-#endif
-
static inline unsigned long brk_rnd(void)
{
return (get_random_int() & BRK_RND_MASK) << PAGE_SHIFT;
diff --git a/arch/powerpc/include/asm/sections.h b/arch/powerpc/include/asm/sections.h
index fddfb3937868..8be2c491c733 100644
--- a/arch/powerpc/include/asm/sections.h
+++ b/arch/powerpc/include/asm/sections.h
@@ -58,29 +58,6 @@ static inline int overlaps_kernel_text(unsigned long start, unsigned long end)
(unsigned long)_stext < end;
}
-#ifdef PPC64_ELF_ABI_v1
-
-#undef dereference_function_descriptor
-static inline void *dereference_function_descriptor(void *ptr)
-{
- struct func_desc *desc = ptr;
- void *p;
-
- if (!get_kernel_nofault(p, (void *)&desc->addr))
- ptr = p;
- return ptr;
-}
-
-#undef dereference_kernel_function_descriptor
-static inline void *dereference_kernel_function_descriptor(void *ptr)
-{
- if (ptr < (void *)__start_opd || ptr >= (void *)__end_opd)
- return ptr;
-
- return dereference_function_descriptor(ptr);
-}
-#endif /* PPC64_ELF_ABI_v1 */
-
#endif
#endif /* __KERNEL__ */
diff --git a/include/asm-generic/sections.h b/include/asm-generic/sections.h
index bbf97502470c..d0f7bdd2fdf2 100644
--- a/include/asm-generic/sections.h
+++ b/include/asm-generic/sections.h
@@ -60,6 +60,8 @@ extern __visible const void __nosave_begin, __nosave_end;
/* Function descriptor handling (if any). Override in asm/sections.h */
#ifdef CONFIG_HAVE_FUNCTION_DESCRIPTORS
+void *dereference_function_descriptor(void *ptr);
+void *dereference_kernel_function_descriptor(void *ptr);
#else
#define dereference_function_descriptor(p) ((void *)(p))
#define dereference_kernel_function_descriptor(p) ((void *)(p))
diff --git a/kernel/extable.c b/kernel/extable.c
index b6f330f0fe74..394c39b86e38 100644
--- a/kernel/extable.c
+++ b/kernel/extable.c
@@ -3,6 +3,7 @@
Copyright (C) 2001 Rusty Russell, 2002 Rusty Russell IBM.
*/
+#include <linux/elf.h>
#include <linux/ftrace.h>
#include <linux/memory.h>
#include <linux/extable.h>
@@ -132,12 +133,32 @@ int kernel_text_address(unsigned long addr)
}
/*
- * On some architectures (PPC64, IA64) function pointers
+ * On some architectures (PPC64, IA64, PARISC) function pointers
* are actually only tokens to some data that then holds the
* real function address. As a result, to find if a function
* pointer is part of the kernel text, we need to do some
* special dereferencing first.
*/
+#ifdef CONFIG_HAVE_FUNCTION_DESCRIPTORS
+void *dereference_function_descriptor(void *ptr)
+{
+ func_desc_t *desc = ptr;
+ void *p;
+
+ if (!get_kernel_nofault(p, (void *)&desc->addr))
+ ptr = p;
+ return ptr;
+}
+
+void *dereference_kernel_function_descriptor(void *ptr)
+{
+ if (ptr < (void *)__start_opd || ptr >= (void *)__end_opd)
+ return ptr;
+
+ return dereference_function_descriptor(ptr);
+}
+#endif
+
int func_ptr_is_kernel_text(void *ptr)
{
unsigned long addr;
--
2.34.1
^ permalink raw reply related
* [PATCH v4 02/13] powerpc: Move and rename func_descr_t
From: Christophe Leroy @ 2022-02-15 12:40 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
Andrew Morton, James E.J. Bottomley, Helge Deller, Arnd Bergmann,
Kees Cook, Greg Kroah-Hartman
Cc: linux-arch, linux-ia64, linux-parisc, linux-kernel, linux-mm,
Nicholas Piggin, linuxppc-dev
In-Reply-To: <cover.1644928018.git.christophe.leroy@csgroup.eu>
There are three architectures with function descriptors, try to
have common names for the address they contain in order to
refactor some functions into generic functions later.
powerpc has 'entry'
ia64 has 'ip'
parisc has 'addr'
Vote for 'addr' and update 'func_descr_t' accordingly.
Move it in asm/elf.h to have it at the same place on all
three architectures, remove the typedef which hides its real
type, and change it to a smoother name 'struct func_desc'.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
---
arch/powerpc/include/asm/code-patching.h | 2 +-
arch/powerpc/include/asm/elf.h | 6 ++++++
arch/powerpc/include/asm/types.h | 6 ------
arch/powerpc/kernel/signal_64.c | 8 ++++----
4 files changed, 11 insertions(+), 11 deletions(-)
diff --git a/arch/powerpc/include/asm/code-patching.h b/arch/powerpc/include/asm/code-patching.h
index e26080539c31..409483b2d0ce 100644
--- a/arch/powerpc/include/asm/code-patching.h
+++ b/arch/powerpc/include/asm/code-patching.h
@@ -118,7 +118,7 @@ static inline unsigned long ppc_function_entry(void *func)
* function's descriptor. The first entry in the descriptor is the
* address of the function text.
*/
- return ((func_descr_t *)func)->entry;
+ return ((struct func_desc *)func)->addr;
#else
return (unsigned long)func;
#endif
diff --git a/arch/powerpc/include/asm/elf.h b/arch/powerpc/include/asm/elf.h
index b8425e3cfd81..971589a21bc0 100644
--- a/arch/powerpc/include/asm/elf.h
+++ b/arch/powerpc/include/asm/elf.h
@@ -176,4 +176,10 @@ do { \
/* Relocate the kernel image to @final_address */
void relocate(unsigned long final_address);
+struct func_desc {
+ unsigned long addr;
+ unsigned long toc;
+ unsigned long env;
+};
+
#endif /* _ASM_POWERPC_ELF_H */
diff --git a/arch/powerpc/include/asm/types.h b/arch/powerpc/include/asm/types.h
index f1630c553efe..97da77bc48c9 100644
--- a/arch/powerpc/include/asm/types.h
+++ b/arch/powerpc/include/asm/types.h
@@ -23,12 +23,6 @@
typedef __vector128 vector128;
-typedef struct {
- unsigned long entry;
- unsigned long toc;
- unsigned long env;
-} func_descr_t;
-
#endif /* __ASSEMBLY__ */
#endif /* _ASM_POWERPC_TYPES_H */
diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c
index d1e1fc0acbea..73d483b07ff3 100644
--- a/arch/powerpc/kernel/signal_64.c
+++ b/arch/powerpc/kernel/signal_64.c
@@ -936,11 +936,11 @@ int handle_rt_signal64(struct ksignal *ksig, sigset_t *set,
* descriptor is the entry address of signal and the second
* entry is the TOC value we need to use.
*/
- func_descr_t __user *funct_desc_ptr =
- (func_descr_t __user *) ksig->ka.sa.sa_handler;
+ struct func_desc __user *ptr =
+ (struct func_desc __user *)ksig->ka.sa.sa_handler;
- err |= get_user(regs->ctr, &funct_desc_ptr->entry);
- err |= get_user(regs->gpr[2], &funct_desc_ptr->toc);
+ err |= get_user(regs->ctr, &ptr->addr);
+ err |= get_user(regs->gpr[2], &ptr->toc);
}
/* enter the signal handler in native-endian mode */
--
2.34.1
^ permalink raw reply related
* [PATCH v4 05/13] powerpc: Prepare func_desc_t for refactorisation
From: Christophe Leroy @ 2022-02-15 12:41 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
Andrew Morton, James E.J. Bottomley, Helge Deller, Arnd Bergmann,
Kees Cook, Greg Kroah-Hartman
Cc: linux-arch, linux-ia64, linux-parisc, linux-kernel, linux-mm,
Nicholas Piggin, linuxppc-dev
In-Reply-To: <cover.1644928018.git.christophe.leroy@csgroup.eu>
In preparation of making func_desc_t generic, change the ELFv2
version to a struct containing 'addr' element.
This allows using single helpers common to ELFv1 and ELFv2 and
reduces the amount of #ifdef's
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
---
arch/powerpc/kernel/module_64.c | 36 ++++++++++++++++-----------------
1 file changed, 18 insertions(+), 18 deletions(-)
diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c
index 46e8eeb7c432..ff93ef4cb5a2 100644
--- a/arch/powerpc/kernel/module_64.c
+++ b/arch/powerpc/kernel/module_64.c
@@ -33,19 +33,17 @@
#ifdef PPC64_ELF_ABI_v2
/* An address is simply the address of the function. */
-typedef unsigned long func_desc_t;
+typedef struct {
+ unsigned long addr;
+} func_desc_t;
static func_desc_t func_desc(unsigned long addr)
{
- return addr;
-}
-static unsigned long func_addr(unsigned long addr)
-{
- return addr;
-}
-static unsigned long stub_func_addr(func_desc_t func)
-{
- return func;
+ func_desc_t desc = {
+ .addr = addr,
+ };
+
+ return desc;
}
/* PowerPC64 specific values for the Elf64_Sym st_other field. */
@@ -70,14 +68,6 @@ static func_desc_t func_desc(unsigned long addr)
{
return *(struct func_desc *)addr;
}
-static unsigned long func_addr(unsigned long addr)
-{
- return func_desc(addr).addr;
-}
-static unsigned long stub_func_addr(func_desc_t func)
-{
- return func.addr;
-}
static unsigned int local_entry_offset(const Elf64_Sym *sym)
{
return 0;
@@ -93,6 +83,16 @@ void *dereference_module_function_descriptor(struct module *mod, void *ptr)
}
#endif
+static unsigned long func_addr(unsigned long addr)
+{
+ return func_desc(addr).addr;
+}
+
+static unsigned long stub_func_addr(func_desc_t func)
+{
+ return func.addr;
+}
+
#define STUB_MAGIC 0x73747562 /* stub */
/* Like PPC32, we need little trampolines to do > 24-bit jumps (into
--
2.34.1
^ permalink raw reply related
* [PATCH v4 04/13] powerpc: Remove 'struct ppc64_opd_entry'
From: Christophe Leroy @ 2022-02-15 12:40 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
Andrew Morton, James E.J. Bottomley, Helge Deller, Arnd Bergmann,
Kees Cook, Greg Kroah-Hartman
Cc: linux-arch, linux-ia64, linux-parisc, linux-kernel, linux-mm,
Nicholas Piggin, linuxppc-dev
In-Reply-To: <cover.1644928018.git.christophe.leroy@csgroup.eu>
'struct ppc64_opd_entry' doesn't belong to uapi/asm/elf.h
It was initially in module_64.c and commit 2d291e902791 ("Fix compile
failure with non modular builds") moved it into asm/elf.h
But it was by mistake added outside of __KERNEL__ section,
therefore commit c3617f72036c ("UAPI: (Scripted) Disintegrate
arch/powerpc/include/asm") moved it to uapi/asm/elf.h
Now that it is not used anymore by the kernel, remove it.
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/include/uapi/asm/elf.h | 8 --------
1 file changed, 8 deletions(-)
diff --git a/arch/powerpc/include/uapi/asm/elf.h b/arch/powerpc/include/uapi/asm/elf.h
index 860c59291bfc..308857123a08 100644
--- a/arch/powerpc/include/uapi/asm/elf.h
+++ b/arch/powerpc/include/uapi/asm/elf.h
@@ -289,12 +289,4 @@ typedef elf_fpreg_t elf_vsrreghalf_t32[ELF_NVSRHALFREG];
/* Keep this the last entry. */
#define R_PPC64_NUM 253
-/* There's actually a third entry here, but it's unused */
-struct ppc64_opd_entry
-{
- unsigned long funcaddr;
- unsigned long r2;
-};
-
-
#endif /* _UAPI_ASM_POWERPC_ELF_H */
--
2.34.1
^ permalink raw reply related
* Re: [PATCH 05/14] uaccess: add generic __{get,put}_kernel_nofault
From: Arnd Bergmann @ 2022-02-15 13:16 UTC (permalink / raw)
To: Al Viro
Cc: Mark Rutland, Rich Felker, linux-ia64, Linux-sh list,
Peter Zijlstra, open list:BROADCOM NVRAM DRIVER, Linux-MM,
Guo Ren, sparclinux, open list:QUALCOMM HEXAGON..., linux-riscv,
Will Deacon, Christoph Hellwig, linux-arch, linux-s390,
Brian Cain, Helge Deller, the arch/x86 maintainers,
Russell King - ARM Linux, linux-csky, Ard Biesheuvel, Ingo Molnar,
Geert Uytterhoeven, open list:SYNOPSYS ARC ARCHITECTURE,
open list:TENSILICA XTENSA PORT (xtensa), Arnd Bergmann,
Heiko Carstens, alpha, linux-um, linuxppc-dev, linux-m68k,
Openrisc, Greentime Hu, Stafford Horne, Linux ARM, Michal Simek,
Thomas Bogendoerfer, Parisc List, Nick Hu, Max Filippov,
Linux API, Linux Kernel Mailing List, Dinh Nguyen,
Eric W . Biederman, Richard Weinberger, Andrew Morton,
Linus Torvalds, David Miller
In-Reply-To: <Ygr0eAA+ZR1eX0wb@zeniv-ca.linux.org.uk>
On Tue, Feb 15, 2022 at 1:31 AM Al Viro <viro@zeniv.linux.org.uk> wrote:
>
> On Mon, Feb 14, 2022 at 05:34:43PM +0100, Arnd Bergmann wrote:
> > From: Arnd Bergmann <arnd@arndb.de>
> >
> > All architectures that don't provide __{get,put}_kernel_nofault() yet
> > can implement this on top of __{get,put}_user.
> >
> > Add a generic version that lets everything use the normal
> > copy_{from,to}_kernel_nofault() code based on these, removing the last
> > use of get_fs()/set_fs() from architecture-independent code.
>
> I'd put the list of those architectures (AFAICS, that's alpha, ia64,
> microblaze, nds32, nios2, openrisc, sh, sparc32, xtensa) into commit
> message - it's not that hard to find out, but...
done.
> And AFAICS, you've missed nios2 - see
> #define __put_user(x, ptr) put_user(x, ptr)
> in there. nds32 oddities are dealt with earlier in the series, this
> one is not...
Ok, fixed my bug in nios2 __put_user() as well now. This one is not nearly
as bad as nds32, at least without my patches it should work as expected.
Unfortunately I also noticed that __get_user() on microblaze and nios2
is completely broken for 64-bit arguments, where these copy eight bytes
into a four byte buffer. I'll try to come up with a fix for this as well then.
Arnd
^ permalink raw reply
* RE: [PATCH 09/14] m68k: drop custom __access_ok()
From: David Laight @ 2022-02-15 13:28 UTC (permalink / raw)
To: 'Arnd Bergmann', Al Viro
Cc: Mark Rutland, Rich Felker, linux-ia64@vger.kernel.org,
Linux-sh list, Peter Zijlstra, open list:BROADCOM NVRAM DRIVER,
Linux-MM, Guo Ren, sparclinux, open list:QUALCOMM HEXAGON...,
linux-riscv, Will Deacon, Christoph Hellwig, linux-arch,
linux-s390, Brian Cain, Helge Deller, the arch/x86 maintainers,
Russell King - ARM Linux, linux-csky@vger.kernel.org,
Ard Biesheuvel, Ingo Molnar, Geert Uytterhoeven,
open list:SYNOPSYS ARC ARCHITECTURE,
open list:TENSILICA XTENSA PORT (xtensa), Arnd Bergmann,
Heiko Carstens, alpha, linux-um, linuxppc-dev, linux-m68k,
Openrisc, Greentime Hu, Stafford Horne, Linux ARM, Michal Simek,
Thomas Bogendoerfer, Parisc List, Nick Hu, Max Filippov,
Linux API, Linux Kernel Mailing List, Dinh Nguyen,
Eric W . Biederman, Richard Weinberger, Andrew Morton,
Linus Torvalds, David Miller
In-Reply-To: <CAK8P3a0t-dnJXvXH0Mx5L-AeVQe1mYzRi0sQjYxzMQw-mVPv0Q@mail.gmail.com>
From: Arnd Bergmann
> Sent: 15 February 2022 10:02
>
> On Tue, Feb 15, 2022 at 8:13 AM Al Viro <viro@zeniv.linux.org.uk> wrote:
> > On Tue, Feb 15, 2022 at 07:29:42AM +0100, Christoph Hellwig wrote:
> > > On Tue, Feb 15, 2022 at 12:37:41AM +0000, Al Viro wrote:
> > > > Perhaps simply wrap that sucker into #ifdef CONFIG_CPU_HAS_ADDRESS_SPACES
> > > > (and trim the comment down to "coldfire and 68000 will pick generic
> > > > variant")?
> > >
> > > I wonder if we should invert CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE,
> > > select the separate address space config for s390, sparc64, non-coldfire
> > > m68k and mips with EVA and then just have one single access_ok for
> > > overlapping address space (as added by Arnd) and non-overlapping ones
> > > (always return true).
> >
> > parisc is also such... How about
> >
> > select ALTERNATE_SPACE_USERLAND
> >
> > for that bunch?
>
> Either of those works for me. My current version has this keyed off
> TASK_SIZE_MAX==ULONG_MAX, but a CONFIG_ symbol does
> look more descriptive.
>
> > While we are at it, how many unusual access_ok() instances are
> > left after this series? arm64, itanic, um, anything else?
>
> x86 adds a WARN_ON_IN_IRQ() check in there.
If is a noop unless CONFIG_DEBUG_ATOMIC_SLEEP is set.
I doubt that is often enabled.
> This could be
> made generic, but it's not obvious what exactly the exceptions are
> that other architectures need. The arm64 tagged pointers could
> probably also get integrated into the generic version.
>
> > FWIW, sparc32 has a slightly unusual instance (see uaccess_32.h there); it's
> > obviously cheaper than generic and I wonder if the trick is legitimate (and
> > applicable elsewhere, perhaps)...
>
> Right, a few others have the same, but I wasn't convinced that this
> is actually safe for call possible cases: it's trivial to construct a caller
> that works on other architectures but not this one, if you pass a large
> enough size value and don't access the contents in sequence.
You'd need code that did an access_ok() check and then read from
a large offset from the address - unlikely.
It's not like the access_ok() check for read/write is done on syscall
entry and then everything underneath assumes it is valid.
Hasn't (almost) everything been checked for function calls between
user_access_begin() and the actual accesses?
And access_ok() is done by/at the same time as user_access_begin()?
You do need an unmapped page above the address that is tested.
> Also, like the ((addr | (addr + size)) & MASK) check on some other
> architectures, it is less portable because it makes assumptions about
> the actual layout beyond a fixed address limit.
Isn't that test broken without a separate bound check on size?
I also seem to remember that access_ok(xxx, 0) is always 'ok'
and some of the 'fast' tests give a false negative if the user
buffer ends with the last byte of user address space.
So you may need:
size < TASK_SIZE && (addr < (TASK_SIZE - size - 1) || !size)
(sprinkled with [un]likely())
David
-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)
^ permalink raw reply
* Re: [PATCH v2 09/13] powerpc/ftrace: Implement CONFIG_DYNAMIC_FTRACE_WITH_ARGS
From: Naveen N. Rao @ 2022-02-15 13:36 UTC (permalink / raw)
To: Christophe Leroy, Jiri Kosina, Joe Lawrence, Josh Poimboeuf,
Miroslav Benes, Ingo Molnar, Michael Ellerman, Petr Mladek,
Steven Rostedt
Cc: live-patching@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
linux-kernel@vger.kernel.org
In-Reply-To: <875ypgo0f3.fsf@mpe.ellerman.id.au>
Michael Ellerman wrote:
> Christophe Leroy <christophe.leroy@csgroup.eu> writes:
>> Le 14/02/2022 à 16:25, Naveen N. Rao a écrit :
>>> Christophe Leroy wrote:
>>>> Implement CONFIG_DYNAMIC_FTRACE_WITH_ARGS. It accelerates the call
>>>> of livepatching.
>>>>
>>>> Also note that powerpc being the last one to convert to
>>>> CONFIG_DYNAMIC_FTRACE_WITH_ARGS, it will now be possible to remove
>>>> klp_arch_set_pc() on all architectures.
>>>>
>>>> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
>>>> ---
>>>> arch/powerpc/Kconfig | 1 +
>>>> arch/powerpc/include/asm/ftrace.h | 17 +++++++++++++++++
>>>> arch/powerpc/include/asm/livepatch.h | 4 +---
>>>> 3 files changed, 19 insertions(+), 3 deletions(-)
>>>>
>>>> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
>>>> index cdac2115eb00..e2b1792b2aae 100644
>>>> --- a/arch/powerpc/Kconfig
>>>> +++ b/arch/powerpc/Kconfig
>>>> @@ -210,6 +210,7 @@ config PPC
>>>> select HAVE_DEBUG_KMEMLEAK
>>>> select HAVE_DEBUG_STACKOVERFLOW
>>>> select HAVE_DYNAMIC_FTRACE
>>>> + select HAVE_DYNAMIC_FTRACE_WITH_ARGS if MPROFILE_KERNEL || PPC32
>>>> select HAVE_DYNAMIC_FTRACE_WITH_REGS if MPROFILE_KERNEL || PPC32
>>>> select HAVE_EBPF_JIT
>>>> select HAVE_EFFICIENT_UNALIGNED_ACCESS if !(CPU_LITTLE_ENDIAN
>>>> && POWER7_CPU)
>>>> diff --git a/arch/powerpc/include/asm/ftrace.h
>>>> b/arch/powerpc/include/asm/ftrace.h
>>>> index b3f6184f77ea..45c3d6f11daa 100644
>>>> --- a/arch/powerpc/include/asm/ftrace.h
>>>> +++ b/arch/powerpc/include/asm/ftrace.h
>>>> @@ -22,6 +22,23 @@ static inline unsigned long
>>>> ftrace_call_adjust(unsigned long addr)
>>>> struct dyn_arch_ftrace {
>>>> struct module *mod;
>>>> };
>>>> +
>>>> +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_ARGS
>>>> +struct ftrace_regs {
>>>> + struct pt_regs regs;
>>>> +};
>>>> +
>>>> +static __always_inline struct pt_regs *arch_ftrace_get_regs(struct
>>>> ftrace_regs *fregs)
>>>> +{
>>>> + return &fregs->regs;
>>>> +}
>>>
>>> I think this is wrong. We need to differentiate between ftrace_caller()
>>> and ftrace_regs_caller() here, and only return pt_regs if coming in
>>> through ftrace_regs_caller() (i.e., FL_SAVE_REGS is set).
>>
>> Not sure I follow you.
>>
>> This is based on 5740a7c71ab6 ("s390/ftrace: add
>> HAVE_DYNAMIC_FTRACE_WITH_ARGS support")
>>
>> It's all the point of HAVE_DYNAMIC_FTRACE_WITH_ARGS, have the regs also
>> with ftrace_caller().
>>
>> Sure you only have the params, but that's the same on s390, so what did
>> I miss ?
It looks like s390 is special since it apparently saves all registers
even for ftrace_caller:
https://lore.kernel.org/all/YbipdU5X4HNDWIni@osiris/
As I understand it, the reason ftrace_get_regs() was introduced was to
be able to only return the pt_regs, if _all_ registers were saved into
it, which we don't do when coming in through ftrace_caller(). See the
x86 implementation (commit 02a474ca266a47 ("ftrace/x86: Allow for
arguments to be passed in to ftrace_regs by default"), which returns
pt_regs conditionally.
>
> I already have this series in next, I can pull it out, but I'd rather
> not.
Yeah, I'm sorry about the late review on this one.
>
> I'll leave it in for now, hopefully you two can agree overnight my time
> whether this is a big problem or something we can fix with a fixup
> patch.
I think changes to this particular patch can be added as an incremental
patch. If anything, pt_regs won't have all valid registers, but no one
should depend on it without also setting FL_SAVE_REGS anyway.
I was concerned about patch 8 though, where we are missing saving r1
into pt_regs. That gets used in patch 11, and will be used during
unwinding when the function_graph tracer is active. But, this should
still just result in us being unable to unwind the stack, so I think
that can also be an incremental patch.
Thanks,
Naveen
^ permalink raw reply
* Re: [PATCH v2 09/13] powerpc/ftrace: Implement CONFIG_DYNAMIC_FTRACE_WITH_ARGS
From: Christophe Leroy @ 2022-02-15 14:28 UTC (permalink / raw)
To: Naveen N. Rao, Jiri Kosina, Joe Lawrence, Josh Poimboeuf,
Miroslav Benes, Ingo Molnar, Michael Ellerman, Petr Mladek,
Steven Rostedt
Cc: live-patching@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
linux-kernel@vger.kernel.org
In-Reply-To: <1644930705.g64na2kgvd.naveen@linux.ibm.com>
Le 15/02/2022 à 14:36, Naveen N. Rao a écrit :
> Michael Ellerman wrote:
>> Christophe Leroy <christophe.leroy@csgroup.eu> writes:
>>> Le 14/02/2022 à 16:25, Naveen N. Rao a écrit :
>>>> Christophe Leroy wrote:
>>>>> Implement CONFIG_DYNAMIC_FTRACE_WITH_ARGS. It accelerates the call
>>>>> of livepatching.
>>>>>
>>>>> Also note that powerpc being the last one to convert to
>>>>> CONFIG_DYNAMIC_FTRACE_WITH_ARGS, it will now be possible to remove
>>>>> klp_arch_set_pc() on all architectures.
>>>>>
>>>>> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
>>>>> ---
>>>>> arch/powerpc/Kconfig | 1 +
>>>>> arch/powerpc/include/asm/ftrace.h | 17 +++++++++++++++++
>>>>> arch/powerpc/include/asm/livepatch.h | 4 +---
>>>>> 3 files changed, 19 insertions(+), 3 deletions(-)
>>>>>
>>>>> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
>>>>> index cdac2115eb00..e2b1792b2aae 100644
>>>>> --- a/arch/powerpc/Kconfig
>>>>> +++ b/arch/powerpc/Kconfig
>>>>> @@ -210,6 +210,7 @@ config PPC
>>>>> select HAVE_DEBUG_KMEMLEAK
>>>>> select HAVE_DEBUG_STACKOVERFLOW
>>>>> select HAVE_DYNAMIC_FTRACE
>>>>> + select HAVE_DYNAMIC_FTRACE_WITH_ARGS if MPROFILE_KERNEL ||
>>>>> PPC32
>>>>> select HAVE_DYNAMIC_FTRACE_WITH_REGS if MPROFILE_KERNEL ||
>>>>> PPC32
>>>>> select HAVE_EBPF_JIT
>>>>> select HAVE_EFFICIENT_UNALIGNED_ACCESS if
>>>>> !(CPU_LITTLE_ENDIAN && POWER7_CPU)
>>>>> diff --git a/arch/powerpc/include/asm/ftrace.h
>>>>> b/arch/powerpc/include/asm/ftrace.h
>>>>> index b3f6184f77ea..45c3d6f11daa 100644
>>>>> --- a/arch/powerpc/include/asm/ftrace.h
>>>>> +++ b/arch/powerpc/include/asm/ftrace.h
>>>>> @@ -22,6 +22,23 @@ static inline unsigned long
>>>>> ftrace_call_adjust(unsigned long addr)
>>>>> struct dyn_arch_ftrace {
>>>>> struct module *mod;
>>>>> };
>>>>> +
>>>>> +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_ARGS
>>>>> +struct ftrace_regs {
>>>>> + struct pt_regs regs;
>>>>> +};
>>>>> +
>>>>> +static __always_inline struct pt_regs *arch_ftrace_get_regs(struct
>>>>> ftrace_regs *fregs)
>>>>> +{
>>>>> + return &fregs->regs;
>>>>> +}
>>>>
>>>> I think this is wrong. We need to differentiate between
>>>> ftrace_caller() and ftrace_regs_caller() here, and only return
>>>> pt_regs if coming in through ftrace_regs_caller() (i.e.,
>>>> FL_SAVE_REGS is set).
>>>
>>> Not sure I follow you.
>>>
>>> This is based on 5740a7c71ab6 ("s390/ftrace: add
>>> HAVE_DYNAMIC_FTRACE_WITH_ARGS support")
>>>
>>> It's all the point of HAVE_DYNAMIC_FTRACE_WITH_ARGS, have the regs
>>> also with ftrace_caller().
>>>
>>> Sure you only have the params, but that's the same on s390, so what
>>> did I miss ?
>
> It looks like s390 is special since it apparently saves all registers
> even for ftrace_caller:
> https://lore.kernel.org/all/YbipdU5X4HNDWIni@osiris/
It is not what I understand from their code, see
https://elixir.bootlin.com/linux/v5.17-rc3/source/arch/s390/kernel/mcount.S#L37
They have a common macro called with argument 'allregs' which is set to
0 for ftrace_caller() and 1 for ftrace_regs_caller().
When allregs == 1, the macro seems to save more.
But ok, I can do like x86, but I need a trick to know whether
FL_SAVE_REGS is set or not, like they do with fregs->regs.cs
Any idea what the condition can be for powerpc ?
Thanks
Christophe
^ permalink raw reply
* Re: [PATCH v2 09/13] powerpc/ftrace: Implement CONFIG_DYNAMIC_FTRACE_WITH_ARGS
From: Steven Rostedt @ 2022-02-15 14:38 UTC (permalink / raw)
To: Naveen N. Rao
Cc: Petr Mladek, Joe Lawrence, Jiri Kosina,
linux-kernel@vger.kernel.org, Ingo Molnar, Masami Hiramatsu,
Josh Poimboeuf, live-patching@vger.kernel.org, Miroslav Benes,
linuxppc-dev@lists.ozlabs.org
In-Reply-To: <1644930705.g64na2kgvd.naveen@linux.ibm.com>
On Tue, 15 Feb 2022 19:06:48 +0530
"Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com> wrote:
> As I understand it, the reason ftrace_get_regs() was introduced was to
> be able to only return the pt_regs, if _all_ registers were saved into
> it, which we don't do when coming in through ftrace_caller(). See the
> x86 implementation (commit 02a474ca266a47 ("ftrace/x86: Allow for
> arguments to be passed in to ftrace_regs by default"), which returns
> pt_regs conditionally.
I can give you the history of ftrace_caller and ftrace_regs_caller.
ftrace_caller saved just enough as was denoted for gcc mcount trampolines.
The new fentry which happens at the start of the function, whereas mcount
happens after the stack frame is set up, may change the rules on some
architectures.
As for ftrace_regs_caller, that was created for kprobes. As the majority of
kprobes were added at the start of the function, it made sense to hook into
ftrace as the ftrace trampoline call is much faster than taking a
breakpoint interrupt. But to keep compatibility with breakpoint
interrupts, we needed to fill in all the registers, and make it act just
like a breakpoint interrupt.
I've been wanting to record function parameters, and because the ftrace
trampoline must at a minimum save the function parameters before calling
the ftrace callbacks, all the information for those parameters were being
saved but were never exposed to the ftrace callbacks. I created the the
DYNAMIC_FTRACE_WITH_ARGS to expose them. I first just used pt_regs with
just the parameters filled in, but that was criticized as it could be
confusing where the non filled in pt_regs might be used and thinking they
are legitimate. So I created ftrace_regs that would give you just the
function arguments (if DYNAMIC_FTRACE_WITH_ARGS is defined), or it will
give you a full pt_regs, if the caller came from the ftrace_regs_caller. If
not, it will give you a NULL pointer.
The first user to use the args was live kernel patching, as they only need
that and the return pointer.
-- Steve
^ permalink raw reply
* Re: [PATCH v2 09/13] powerpc/ftrace: Implement CONFIG_DYNAMIC_FTRACE_WITH_ARGS
From: Christophe Leroy @ 2022-02-15 14:51 UTC (permalink / raw)
To: Naveen N. Rao, Jiri Kosina, Joe Lawrence, Josh Poimboeuf,
Miroslav Benes, Ingo Molnar, Michael Ellerman, Petr Mladek,
Steven Rostedt, Heiko Carstens, Vasily Gorbik
Cc: linux-s390@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
linux-kernel@vger.kernel.org, live-patching@vger.kernel.org
In-Reply-To: <6dc50f09-4d14-afa2-d2a1-34b72b880edf@csgroup.eu>
+ S390 people
Le 15/02/2022 à 15:28, Christophe Leroy a écrit :
>
>
> Le 15/02/2022 à 14:36, Naveen N. Rao a écrit :
>> Michael Ellerman wrote:
>>> Christophe Leroy <christophe.leroy@csgroup.eu> writes:
>>>> Le 14/02/2022 à 16:25, Naveen N. Rao a écrit :
>>>>> Christophe Leroy wrote:
>>>>>> Implement CONFIG_DYNAMIC_FTRACE_WITH_ARGS. It accelerates the call
>>>>>> of livepatching.
>>>>>>
>>>>>> Also note that powerpc being the last one to convert to
>>>>>> CONFIG_DYNAMIC_FTRACE_WITH_ARGS, it will now be possible to remove
>>>>>> klp_arch_set_pc() on all architectures.
>>>>>>
>>>>>> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
>>>>>> ---
>>>>>> arch/powerpc/Kconfig | 1 +
>>>>>> arch/powerpc/include/asm/ftrace.h | 17 +++++++++++++++++
>>>>>> arch/powerpc/include/asm/livepatch.h | 4 +---
>>>>>> 3 files changed, 19 insertions(+), 3 deletions(-)
>>>>>>
>>>>>> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
>>>>>> index cdac2115eb00..e2b1792b2aae 100644
>>>>>> --- a/arch/powerpc/Kconfig
>>>>>> +++ b/arch/powerpc/Kconfig
>>>>>> @@ -210,6 +210,7 @@ config PPC
>>>>>> select HAVE_DEBUG_KMEMLEAK
>>>>>> select HAVE_DEBUG_STACKOVERFLOW
>>>>>> select HAVE_DYNAMIC_FTRACE
>>>>>> + select HAVE_DYNAMIC_FTRACE_WITH_ARGS if MPROFILE_KERNEL ||
>>>>>> PPC32
>>>>>> select HAVE_DYNAMIC_FTRACE_WITH_REGS if MPROFILE_KERNEL ||
>>>>>> PPC32
>>>>>> select HAVE_EBPF_JIT
>>>>>> select HAVE_EFFICIENT_UNALIGNED_ACCESS if
>>>>>> !(CPU_LITTLE_ENDIAN && POWER7_CPU)
>>>>>> diff --git a/arch/powerpc/include/asm/ftrace.h
>>>>>> b/arch/powerpc/include/asm/ftrace.h
>>>>>> index b3f6184f77ea..45c3d6f11daa 100644
>>>>>> --- a/arch/powerpc/include/asm/ftrace.h
>>>>>> +++ b/arch/powerpc/include/asm/ftrace.h
>>>>>> @@ -22,6 +22,23 @@ static inline unsigned long
>>>>>> ftrace_call_adjust(unsigned long addr)
>>>>>> struct dyn_arch_ftrace {
>>>>>> struct module *mod;
>>>>>> };
>>>>>> +
>>>>>> +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_ARGS
>>>>>> +struct ftrace_regs {
>>>>>> + struct pt_regs regs;
>>>>>> +};
>>>>>> +
>>>>>> +static __always_inline struct pt_regs
>>>>>> *arch_ftrace_get_regs(struct ftrace_regs *fregs)
>>>>>> +{
>>>>>> + return &fregs->regs;
>>>>>> +}
>>>>>
>>>>> I think this is wrong. We need to differentiate between
>>>>> ftrace_caller() and ftrace_regs_caller() here, and only return
>>>>> pt_regs if coming in through ftrace_regs_caller() (i.e.,
>>>>> FL_SAVE_REGS is set).
>>>>
>>>> Not sure I follow you.
>>>>
>>>> This is based on 5740a7c71ab6 ("s390/ftrace: add
>>>> HAVE_DYNAMIC_FTRACE_WITH_ARGS support")
>>>>
>>>> It's all the point of HAVE_DYNAMIC_FTRACE_WITH_ARGS, have the regs
>>>> also with ftrace_caller().
>>>>
>>>> Sure you only have the params, but that's the same on s390, so what
>>>> did I miss ?
>>
>> It looks like s390 is special since it apparently saves all registers
>> even for ftrace_caller:
>> https://lore.kernel.org/all/YbipdU5X4HNDWIni@osiris/
>
> It is not what I understand from their code, see
> https://elixir.bootlin.com/linux/v5.17-rc3/source/arch/s390/kernel/mcount.S#L37
>
>
> They have a common macro called with argument 'allregs' which is set to
> 0 for ftrace_caller() and 1 for ftrace_regs_caller().
> When allregs == 1, the macro seems to save more.
>
> But ok, I can do like x86, but I need a trick to know whether
> FL_SAVE_REGS is set or not, like they do with fregs->regs.cs
> Any idea what the condition can be for powerpc ?
>
Finally, it looks like this change is done via commit 894979689d3a
("s390/ftrace: provide separate ftrace_caller/ftrace_regs_caller
implementations") four hours the same day after the implementation of
arch_ftrace_get_regs()
They may have forgotten to change arch_ftrace_get_regs() which was added
in commit 5740a7c71ab6 ("s390/ftrace: add HAVE_DYNAMIC_FTRACE_WITH_ARGS
support") with the assumption that ftrace_caller and ftrace_regs_caller
where identical.
Christophe
^ permalink raw reply
* Re: [PATCH v4 01/13] powerpc: Fix 'sparse' checking on PPC64le
From: Kees Cook @ 2022-02-15 16:06 UTC (permalink / raw)
To: Christophe Leroy
Cc: linux-arch, linux-ia64, linux-parisc, Arnd Bergmann,
Greg Kroah-Hartman, Helge Deller, linux-kernel,
James E.J. Bottomley, linux-mm, Paul Mackerras, Andrew Morton,
linuxppc-dev
In-Reply-To: <ac1312f2451aa558bb2a8806b4d0aa2020f0c176.1644928018.git.christophe.leroy@csgroup.eu>
On Tue, Feb 15, 2022 at 01:40:56PM +0100, Christophe Leroy wrote:
> 'sparse' is architecture agnostic and knows nothing about ELF ABI
> version.
>
> Just like it gets arch and powerpc type and endian from Makefile,
> it also need to get _CALL_ELF from there, otherwise it won't set
> PPC64_ELF_ABI_v2 macro for PPC64le and won't check the correct code.
>
> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Kees Cook <keescook@chromium.org>
--
Kees Cook
^ permalink raw reply
* Re: [PATCH v4 00/13] Fix LKDTM for PPC64/IA64/PARISC v4
From: Kees Cook @ 2022-02-15 16:07 UTC (permalink / raw)
To: Christophe Leroy
Cc: linux-arch, linux-ia64, linux-parisc, Arnd Bergmann,
Greg Kroah-Hartman, Helge Deller, linux-kernel,
James E.J. Bottomley, linux-mm, Paul Mackerras, Andrew Morton,
linuxppc-dev
In-Reply-To: <cover.1644928018.git.christophe.leroy@csgroup.eu>
On Tue, Feb 15, 2022 at 01:40:55PM +0100, Christophe Leroy wrote:
> PPC64/IA64/PARISC have function descriptors. LKDTM doesn't work
> on those three architectures because LKDTM messes up function
> descriptors with functions.
>
> This series does some cleanup in the three architectures and
> refactors function descriptors so that it can then easily use it
> in a generic way in LKDTM.
Thanks for doing this! It looks good to me. :)
-Kees
>
> Changes in v4:
> - Added patch 1 which Fixes 'sparse' for powerpc64le after wrong report on previous series, refer https://github.com/ruscur/linux-ci/actions/runs/1351427671
> - Exported dereference_function_descriptor() to modules
> - Addressed other received comments
> - Rebased on latest powerpc/next (5a72345e6a78120368fcc841b570331b6c5a50da)
>
> Changes in v3:
> - Addressed received comments
> - Swapped some of the powerpc patches to keep func_descr_t renamed as struct func_desc and remove 'struct ppc64_opd_entry'
> - Changed HAVE_FUNCTION_DESCRIPTORS macro to a config item CONFIG_HAVE_FUNCTION_DESCRIPTORS
> - Dropped patch 11 ("Fix lkdtm_EXEC_RODATA()")
>
> Changes in v2:
> - Addressed received comments
> - Moved dereference_[kernel]_function_descriptor() out of line
> - Added patches to remove func_descr_t and func_desc_t in powerpc
> - Using func_desc_t instead of funct_descr_t
> - Renamed HAVE_DEREFERENCE_FUNCTION_DESCRIPTOR to HAVE_FUNCTION_DESCRIPTORS
> - Added a new lkdtm test to check protection of function descriptors
>
> Christophe Leroy (13):
> powerpc: Fix 'sparse' checking on PPC64le
> powerpc: Move and rename func_descr_t
> powerpc: Use 'struct func_desc' instead of 'struct ppc64_opd_entry'
> powerpc: Remove 'struct ppc64_opd_entry'
> powerpc: Prepare func_desc_t for refactorisation
> ia64: Rename 'ip' to 'addr' in 'struct fdesc'
> asm-generic: Define CONFIG_HAVE_FUNCTION_DESCRIPTORS
> asm-generic: Define 'func_desc_t' to commonly describe function
> descriptors
> asm-generic: Refactor dereference_[kernel]_function_descriptor()
> lkdtm: Force do_nothing() out of line
> lkdtm: Really write into kernel text in WRITE_KERN
> lkdtm: Fix execute_[user]_location()
> lkdtm: Add a test for function descriptors protection
>
> arch/Kconfig | 3 +
> arch/ia64/Kconfig | 1 +
> arch/ia64/include/asm/elf.h | 2 +-
> arch/ia64/include/asm/sections.h | 24 +-------
> arch/ia64/kernel/module.c | 6 +-
> arch/parisc/Kconfig | 1 +
> arch/parisc/include/asm/sections.h | 16 ++----
> arch/parisc/kernel/process.c | 21 -------
> arch/powerpc/Kconfig | 1 +
> arch/powerpc/Makefile | 2 +-
> arch/powerpc/include/asm/code-patching.h | 2 +-
> arch/powerpc/include/asm/elf.h | 6 ++
> arch/powerpc/include/asm/sections.h | 29 ++--------
> arch/powerpc/include/asm/types.h | 6 --
> arch/powerpc/include/uapi/asm/elf.h | 8 ---
> arch/powerpc/kernel/module_64.c | 42 ++++++--------
> arch/powerpc/kernel/ptrace/ptrace.c | 6 ++
> arch/powerpc/kernel/signal_64.c | 8 +--
> drivers/misc/lkdtm/core.c | 1 +
> drivers/misc/lkdtm/lkdtm.h | 1 +
> drivers/misc/lkdtm/perms.c | 71 +++++++++++++++++++-----
> include/asm-generic/sections.h | 15 ++++-
> include/linux/kallsyms.h | 2 +-
> kernel/extable.c | 24 +++++++-
> tools/testing/selftests/lkdtm/tests.txt | 1 +
> 25 files changed, 155 insertions(+), 144 deletions(-)
>
> --
> 2.34.1
>
--
Kees Cook
^ permalink raw reply
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