[-tip,v4,1/3] kasan: Emit different calls for instrumentable memintrinsics
Commit Message
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).
Fixes: 69d4c0d32186 ("entry, kasan, x86: Disallow overriding mem*() functions")
Signed-off-by: Marco Elver <elver@google.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
v4:
* Also enable it for KASAN_SW_TAGS (__hwasan_mem*).
v3:
* No change.
v2:
* Use asan-kernel-mem-intrinsic-prefix=1, so that once GCC supports the
param, it also works there (it needs the =1).
The Fixes tag is just there to show the dependency, and that people
shouldn't apply this patch without 69d4c0d32186.
---
mm/kasan/kasan.h | 4 ++++
mm/kasan/shadow.c | 11 +++++++++++
scripts/Makefile.kasan | 8 ++++++++
3 files changed, 23 insertions(+)
Comments
On Fri, Feb 17, 2023 at 12:45 AM Marco Elver <elver@google.com> wrote:
>
> 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).
>
> Fixes: 69d4c0d32186 ("entry, kasan, x86: Disallow overriding mem*() functions")
> Signed-off-by: Marco Elver <elver@google.com>
> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> ---
> v4:
> * Also enable it for KASAN_SW_TAGS (__hwasan_mem*).
>
> v3:
> * No change.
>
> v2:
> * Use asan-kernel-mem-intrinsic-prefix=1, so that once GCC supports the
> param, it also works there (it needs the =1).
>
> The Fixes tag is just there to show the dependency, and that people
> shouldn't apply this patch without 69d4c0d32186.
> ---
> mm/kasan/kasan.h | 4 ++++
> mm/kasan/shadow.c | 11 +++++++++++
> scripts/Makefile.kasan | 8 ++++++++
> 3 files changed, 23 insertions(+)
>
> diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
> index 71c15438afcf..172713b87556 100644
> --- a/mm/kasan/kasan.h
> +++ b/mm/kasan/kasan.h
> @@ -637,4 +637,8 @@ 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 */
> diff --git a/mm/kasan/shadow.c b/mm/kasan/shadow.c
> index 98269936a5e4..f8a47cb299cb 100644
> --- a/mm/kasan/shadow.c
> +++ b/mm/kasan/shadow.c
> @@ -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;
> diff --git a/scripts/Makefile.kasan b/scripts/Makefile.kasan
> index b9e94c5e7097..fa9f836f8039 100644
> --- a/scripts/Makefile.kasan
> +++ b/scripts/Makefile.kasan
> @@ -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
> --
> 2.39.2.637.g21b0678d19-goog
>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
> 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).
> Fixes: 69d4c0d32186 ("entry, kasan, x86: Disallow overriding mem*() functions")
> Signed-off-by: Marco Elver <elver@google.com>
> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Tested Kunit tests with clang-15, clang-16 and gcc-12 the reported
issues got fixed.
ref:
https://lkft.validation.linaro.org/scheduler/job/6172341#L618
https://lkft.validation.linaro.org/scheduler/job/6172351#L618
https://lkft.validation.linaro.org/scheduler/job/6172338#L618
https://lore.kernel.org/all/CA+G9fYvZqytp3gMnC4-no9EB=Jnzqmu44i8JQo6apiZat-xxPg@mail.gmail.com/
--
Linaro LKFT
https://lkft.linaro.org
@@ -637,4 +637,8 @@ 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 */
@@ -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;
@@ -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