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authorMarco Elver <elver@google.com>2023-02-24 09:59:40 +0100
committerAndrew Morton <akpm@linux-foundation.org>2023-03-02 21:54:22 -0800
commit36be5cba99f6f9984a9a9f0454f95a38f4184d3e (patch)
tree46a3e656766dce4b37782d3c180393fbb6392626 /mm/kasan
parent51287dcb00cc715c27bf6a6b4dbd431621c5b65a (diff)
kasan: treat meminstrinsic as builtins in uninstrumented files
Where the compiler instruments meminstrinsics by generating calls to __asan/__hwasan_ prefixed functions, let the compiler consider memintrinsics as builtin again. To do so, never override memset/memmove/memcpy if the compiler does the correct instrumentation - even on !GENERIC_ENTRY architectures. [elver@google.com: powerpc: don't rename memintrinsics if compiler adds prefixes] Link: https://lore.kernel.org/all/20230224085942.1791837-1-elver@google.com/ [1] Link: https://lkml.kernel.org/r/20230227094726.3833247-1-elver@google.com Link: https://lkml.kernel.org/r/20230224085942.1791837-2-elver@google.com Fixes: 69d4c0d32186 ("entry, kasan, x86: Disallow overriding mem*() functions") Signed-off-by: Marco Elver <elver@google.com> Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Tested-by: Linux Kernel Functional Testing <lkft@linaro.org> Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) 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: Kees Cook <keescook@chromium.org> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Nicolas Schier <nicolas@fjasle.eu> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/kasan')
-rw-r--r--mm/kasan/shadow.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/mm/kasan/shadow.c b/mm/kasan/shadow.c
index 90186122b21b..c8b86f3273b5 100644
--- a/mm/kasan/shadow.c
+++ b/mm/kasan/shadow.c
@@ -38,11 +38,14 @@ bool __kasan_check_write(const volatile void *p, unsigned int size)
}
EXPORT_SYMBOL(__kasan_check_write);
-#ifndef CONFIG_GENERIC_ENTRY
+#if !defined(CONFIG_CC_HAS_KASAN_MEMINTRINSIC_PREFIX) && !defined(CONFIG_GENERIC_ENTRY)
/*
* CONFIG_GENERIC_ENTRY relies on compiler emitted mem*() calls to not be
* instrumented. KASAN enabled toolchains should emit __asan_mem*() functions
* for the sites they want to instrument.
+ *
+ * If we have a compiler that can instrument meminstrinsics, never override
+ * these, so that non-instrumented files can safely consider them as builtins.
*/
#undef memset
void *memset(void *addr, int c, size_t len)