iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

kasan: emit different calls for instrumentable memintrinsics

Browse Source 
Clang 15 provides an option to prefix memcpy/memset/memmove calls with
__asan_/__hwasan_ in instrumented functions:
https://reviews.llvm.org/D122724

GCC will add support in future:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108777

Use it to regain KASAN instrumentation of memcpy/memset/memmove on
architectures that require noinstr to be really free from instrumented
mem*() functions (all GENERIC_ENTRY architectures).

Link: https://lkml.kernel.org/r/20230224085942.1791837-1-elver@google.com
Fixes: 69d4c0d321 ("entry, kasan, x86: Disallow overriding mem*() functions")
Signed-off-by: Marco Elver <elver@google.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jakub Jelinek <jakub@redhat.com>
Cc: kasan-dev@googlegroups.com
Cc: Kees Cook <keescook@chromium.org>
Cc: Linux Kernel Functional Testing <lkft@linaro.org>
Cc: Nathan Chancellor <nathan@kernel.org> # build only
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Nicolas Schier <nicolas@fjasle.eu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Marco Elver 2023-02-24 09:59:39 +01:00 committed by Andrew Morton
parent 236b9254f8
commit 51287dcb00
3 changed files with 23 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
mm/kasan/kasan.h
View File

@ -666,4 +666,8 @@ void __hwasan_storeN_noabort(unsigned long addr, size_t size);
void __hwasan_tag_memory(unsigned long addr, u8 tag, unsigned long size);
void *__hwasan_memset(void *addr, int c, size_t len);
void *__hwasan_memmove(void *dest, const void *src, size_t len);
void *__hwasan_memcpy(void *dest, const void *src, size_t len);
#endif /* __MM_KASAN_KASAN_H */

11
mm/kasan/shadow.c
View File

@ -107,6 +107,17 @@ void *__asan_memcpy(void *dest, const void *src, size_t len)
}
EXPORT_SYMBOL(__asan_memcpy);
#ifdef CONFIG_KASAN_SW_TAGS
void *__hwasan_memset(void *addr, int c, size_t len) __alias(__asan_memset);
EXPORT_SYMBOL(__hwasan_memset);
#ifdef __HAVE_ARCH_MEMMOVE
void *__hwasan_memmove(void *dest, const void *src, size_t len) __alias(__asan_memmove);
EXPORT_SYMBOL(__hwasan_memmove);
#endif
void *__hwasan_memcpy(void *dest, const void *src, size_t len) __alias(__asan_memcpy);
EXPORT_SYMBOL(__hwasan_memcpy);
#endif
void kasan_poison(const void *addr, size_t size, u8 value, bool init)
{
void *shadow_start, *shadow_end;

8
scripts/Makefile.kasan
View File

@ -38,6 +38,11 @@ endif
CFLAGS_KASAN += $(call cc-param,asan-stack=$(stack_enable))
# Instrument memcpy/memset/memmove calls by using instrumented __asan_mem*()
# instead. With compilers that don't support this option, compiler-inserted
# memintrinsics won't be checked by KASAN on GENERIC_ENTRY architectures.
CFLAGS_KASAN += $(call cc-param,asan-kernel-mem-intrinsic-prefix=1)
endif # CONFIG_KASAN_GENERIC
ifdef CONFIG_KASAN_SW_TAGS
@ -54,6 +59,9 @@ CFLAGS_KASAN := -fsanitize=kernel-hwaddress \
$(call cc-param,hwasan-inline-all-checks=0) \
$(instrumentation_flags)
# Instrument memcpy/memset/memmove calls by using instrumented __hwasan_mem*().
CFLAGS_KASAN += $(call cc-param,hwasan-kernel-mem-intrinsic-prefix=1)
endif # CONFIG_KASAN_SW_TAGS
export CFLAGS_KASAN CFLAGS_KASAN_NOSANITIZE