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author | Alexey Samsonov <samsonov@google.com> | 2012-08-22 10:12:47 +0000 |
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committer | Alexey Samsonov <samsonov@google.com> | 2012-08-22 10:12:47 +0000 |
commit | b21de9e71522a7f9ed31fd92aafe6936873a971c (patch) | |
tree | d6f97a4c013d37ab39a957e853c36493db53f7e6 /lib | |
parent | df1f2eff455d823e0f211fe3607cce7f4f17bef7 (diff) | |
download | compiler-rt-b21de9e71522a7f9ed31fd92aafe6936873a971c.tar.gz compiler-rt-b21de9e71522a7f9ed31fd92aafe6936873a971c.tar.bz2 compiler-rt-b21de9e71522a7f9ed31fd92aafe6936873a971c.tar.xz |
[ASan] make ASan malloc/free hooks weak interface functions, overridable by user. Now the user can control malloc/free hooks without recompiling ASan runtime
git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@162355 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib')
-rw-r--r-- | lib/asan/asan_allocator.cc | 49 | ||||
-rw-r--r-- | lib/asan/asan_interface.h | 11 | ||||
-rw-r--r-- | lib/asan/asan_rtl.cc | 2 | ||||
-rw-r--r-- | lib/asan/lit_tests/malloc_hook.cc | 20 |
4 files changed, 54 insertions, 28 deletions
diff --git a/lib/asan/asan_allocator.cc b/lib/asan/asan_allocator.cc index 7d00de12..1c74fc14 100644 --- a/lib/asan/asan_allocator.cc +++ b/lib/asan/asan_allocator.cc @@ -788,45 +788,38 @@ static u8 *Reallocate(u8 *old_ptr, uptr new_size, } // namespace __asan -// Malloc hooks declaration. -// ASAN_NEW_HOOK(ptr, size) is called immediately after -// allocation of "size" bytes, which returned "ptr". -// ASAN_DELETE_HOOK(ptr) is called immediately before -// deallocation of "ptr". -// If ASAN_NEW_HOOK or ASAN_DELETE_HOOK is defined, user -// program must provide implementation of this hook. -// If macro is undefined, the hook is no-op. -#ifdef ASAN_NEW_HOOK -extern "C" void ASAN_NEW_HOOK(void *ptr, uptr size); -#else -static inline void ASAN_NEW_HOOK(void *ptr, uptr size) { } -#endif - -#ifdef ASAN_DELETE_HOOK -extern "C" void ASAN_DELETE_HOOK(void *ptr); -#else -static inline void ASAN_DELETE_HOOK(void *ptr) { } -#endif +// Default (no-op) implementation of malloc hooks. +extern "C" { +SANITIZER_WEAK_ATTRIBUTE SANITIZER_INTERFACE_ATTRIBUTE +void __asan_malloc_hook(void *ptr, uptr size) { + (void)ptr; + (void)size; +} +SANITIZER_WEAK_ATTRIBUTE SANITIZER_INTERFACE_ATTRIBUTE +void __asan_free_hook(void *ptr) { + (void)ptr; +} +} // extern "C" namespace __asan { SANITIZER_INTERFACE_ATTRIBUTE void *asan_memalign(uptr alignment, uptr size, AsanStackTrace *stack) { void *ptr = (void*)Allocate(alignment, size, stack); - ASAN_NEW_HOOK(ptr, size); + __asan_malloc_hook(ptr, size); return ptr; } SANITIZER_INTERFACE_ATTRIBUTE void asan_free(void *ptr, AsanStackTrace *stack) { - ASAN_DELETE_HOOK(ptr); + __asan_free_hook(ptr); Deallocate((u8*)ptr, stack); } SANITIZER_INTERFACE_ATTRIBUTE void *asan_malloc(uptr size, AsanStackTrace *stack) { void *ptr = (void*)Allocate(0, size, stack); - ASAN_NEW_HOOK(ptr, size); + __asan_malloc_hook(ptr, size); return ptr; } @@ -834,17 +827,17 @@ void *asan_calloc(uptr nmemb, uptr size, AsanStackTrace *stack) { void *ptr = (void*)Allocate(0, nmemb * size, stack); if (ptr) REAL(memset)(ptr, 0, nmemb * size); - ASAN_NEW_HOOK(ptr, nmemb * size); + __asan_malloc_hook(ptr, nmemb * size); return ptr; } void *asan_realloc(void *p, uptr size, AsanStackTrace *stack) { if (p == 0) { void *ptr = (void*)Allocate(0, size, stack); - ASAN_NEW_HOOK(ptr, size); + __asan_malloc_hook(ptr, size); return ptr; } else if (size == 0) { - ASAN_DELETE_HOOK(p); + __asan_free_hook(p); Deallocate((u8*)p, stack); return 0; } @@ -853,7 +846,7 @@ void *asan_realloc(void *p, uptr size, AsanStackTrace *stack) { void *asan_valloc(uptr size, AsanStackTrace *stack) { void *ptr = (void*)Allocate(kPageSize, size, stack); - ASAN_NEW_HOOK(ptr, size); + __asan_malloc_hook(ptr, size); return ptr; } @@ -864,7 +857,7 @@ void *asan_pvalloc(uptr size, AsanStackTrace *stack) { size = kPageSize; } void *ptr = (void*)Allocate(kPageSize, size, stack); - ASAN_NEW_HOOK(ptr, size); + __asan_malloc_hook(ptr, size); return ptr; } @@ -872,7 +865,7 @@ int asan_posix_memalign(void **memptr, uptr alignment, uptr size, AsanStackTrace *stack) { void *ptr = Allocate(alignment, size, stack); CHECK(IsAligned((uptr)ptr, alignment)); - ASAN_NEW_HOOK(ptr, size); + __asan_malloc_hook(ptr, size); *memptr = ptr; return 0; } diff --git a/lib/asan/asan_interface.h b/lib/asan/asan_interface.h index c19dc76b..5a233299 100644 --- a/lib/asan/asan_interface.h +++ b/lib/asan/asan_interface.h @@ -175,6 +175,17 @@ extern "C" { // ASan runtime options. See asan_flags.h for details. const char* __asan_default_options() SANITIZER_WEAK_ATTRIBUTE SANITIZER_INTERFACE_ATTRIBUTE; + + // Malloc hooks that may be overriden by user. + // __asan_malloc_hook(ptr, size) is called immediately after + // allocation of "size" bytes, which returned "ptr". + // __asan_free_hook(ptr) is called immediately before + // deallocation of "ptr". + // If user doesn't provide implementations of these hooks, they are no-op. + void __asan_malloc_hook(void *ptr, uptr size) + SANITIZER_WEAK_ATTRIBUTE SANITIZER_INTERFACE_ATTRIBUTE; + void __asan_free_hook(void *ptr) + SANITIZER_WEAK_ATTRIBUTE SANITIZER_INTERFACE_ATTRIBUTE; } // extern "C" #endif // ASAN_INTERFACE_H diff --git a/lib/asan/asan_rtl.cc b/lib/asan/asan_rtl.cc index edaf580c..2e83067a 100644 --- a/lib/asan/asan_rtl.cc +++ b/lib/asan/asan_rtl.cc @@ -250,6 +250,8 @@ static NOINLINE void force_interface_symbols() { case 31: __asan_default_options(); break; case 32: __asan_before_dynamic_init(0, 0); break; case 33: __asan_after_dynamic_init(); break; + case 34: __asan_malloc_hook(0, 0); break; + case 35: __asan_free_hook(0); break; } } diff --git a/lib/asan/lit_tests/malloc_hook.cc b/lib/asan/lit_tests/malloc_hook.cc new file mode 100644 index 00000000..885fc669 --- /dev/null +++ b/lib/asan/lit_tests/malloc_hook.cc @@ -0,0 +1,20 @@ +// RUN: %clangxx_asan -O2 %s -o %t +// RUN: %t 2>&1 | FileCheck %s +#include <stdio.h> +#include <stdlib.h> + +extern "C" { +// Note: avoid calling functions that allocate memory in malloc/free +// to avoid infinite recursion. +void __asan_malloc_hook(void *ptr, size_t sz) { puts("MallocHook"); } +void __asan_free_hook(void *ptr) { puts("FreeHook"); } +} // extern "C" + +int main() { + volatile int *x = new int; + // CHECK: MallocHook + *x = 0; + delete x; + // CHECK: FreeHook + return 0; +} |