From: Marco Elver <elver@google.com>
To: elver@google.com, Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>, Jakub Jelinek <jakub@redhat.com>,
linux-toolchains@vger.kernel.org,
Andrey Ryabinin <ryabinin.a.a@gmail.com>,
Alexander Potapenko <glider@google.com>,
Andrey Konovalov <andreyknvl@gmail.com>,
Dmitry Vyukov <dvyukov@google.com>,
Andrew Morton <akpm@linux-foundation.org>,
Nathan Chancellor <nathan@kernel.org>,
Nick Desaulniers <ndesaulniers@google.com>,
kasan-dev@googlegroups.com, linux-kernel@vger.kernel.org,
linux-mm@kvack.org, linux-kbuild@vger.kernel.org
Subject: [PATCH -tip v4 1/3] kasan: Emit different calls for instrumentable memintrinsics
Date: Fri, 17 Feb 2023 00:45:20 +0100 [thread overview]
Message-ID: <20230216234522.3757369-1-elver@google.com> (raw)
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
next reply other threads:[~2023-02-16 23:45 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-16 23:45 Marco Elver [this message]
2023-02-16 23:45 ` [PATCH -tip v4 2/3] kasan: Treat meminstrinsic as builtins in uninstrumented files Marco Elver
2023-02-17 11:07 ` Andrey Konovalov
2023-02-17 12:55 ` Marco Elver
2023-02-16 23:45 ` [PATCH -tip v4 3/3] kasan: test: Fix test for new meminstrinsic instrumentation Marco Elver
2023-02-17 9:11 ` Alexander Potapenko
2023-02-17 11:07 ` Andrey Konovalov
2023-02-17 11:07 ` [PATCH -tip v4 1/3] kasan: Emit different calls for instrumentable memintrinsics Andrey Konovalov
2023-02-17 12:53 ` [PATCH -tip v4 4/4] kasan, x86: Don't rename memintrinsics in uninstrumented files Marco Elver
2023-02-17 13:10 ` Andrey Konovalov
2023-02-17 17:37 ` [PATCH -tip v4 1/3] kasan: Emit different calls for instrumentable memintrinsics Naresh Kamboju
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