1//===-- asan_malloc_linux.cc ----------------------------------------------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file is a part of AddressSanitizer, an address sanity checker. 11// 12// Linux-specific malloc interception. 13// We simply define functions like malloc, free, realloc, etc. 14// They will replace the corresponding libc functions automagically. 15//===----------------------------------------------------------------------===// 16 17#include "sanitizer_common/sanitizer_platform.h" 18#if SANITIZER_FREEBSD || SANITIZER_LINUX 19 20#include "sanitizer_common/sanitizer_tls_get_addr.h" 21#include "asan_allocator.h" 22#include "asan_interceptors.h" 23#include "asan_internal.h" 24#include "asan_stack.h" 25 26// ---------------------- Replacement functions ---------------- {{{1 27using namespace __asan; // NOLINT 28 29INTERCEPTOR(void, free, void *ptr) { 30 GET_STACK_TRACE_FREE; 31 asan_free(ptr, &stack, FROM_MALLOC); 32} 33 34INTERCEPTOR(void, cfree, void *ptr) { 35 GET_STACK_TRACE_FREE; 36 asan_free(ptr, &stack, FROM_MALLOC); 37} 38 39INTERCEPTOR(void*, malloc, uptr size) { 40 GET_STACK_TRACE_MALLOC; 41 return asan_malloc(size, &stack); 42} 43 44INTERCEPTOR(void*, calloc, uptr nmemb, uptr size) { 45 if (UNLIKELY(!asan_inited)) { 46 // Hack: dlsym calls calloc before REAL(calloc) is retrieved from dlsym. 47 const uptr kCallocPoolSize = 1024; 48 static uptr calloc_memory_for_dlsym[kCallocPoolSize]; 49 static uptr allocated; 50 uptr size_in_words = ((nmemb * size) + kWordSize - 1) / kWordSize; 51 void *mem = (void*)&calloc_memory_for_dlsym[allocated]; 52 allocated += size_in_words; 53 CHECK(allocated < kCallocPoolSize); 54 return mem; 55 } 56 GET_STACK_TRACE_MALLOC; 57 return asan_calloc(nmemb, size, &stack); 58} 59 60INTERCEPTOR(void*, realloc, void *ptr, uptr size) { 61 GET_STACK_TRACE_MALLOC; 62 return asan_realloc(ptr, size, &stack); 63} 64 65INTERCEPTOR(void*, memalign, uptr boundary, uptr size) { 66 GET_STACK_TRACE_MALLOC; 67 return asan_memalign(boundary, size, &stack, FROM_MALLOC); 68} 69 70INTERCEPTOR(void*, aligned_alloc, uptr boundary, uptr size) { 71 GET_STACK_TRACE_MALLOC; 72 return asan_memalign(boundary, size, &stack, FROM_MALLOC); 73} 74 75INTERCEPTOR(void*, __libc_memalign, uptr boundary, uptr size) { 76 GET_STACK_TRACE_MALLOC; 77 void *res = asan_memalign(boundary, size, &stack, FROM_MALLOC); 78 DTLS_on_libc_memalign(res, size * boundary); 79 return res; 80} 81 82INTERCEPTOR(uptr, malloc_usable_size, void *ptr) { 83 GET_CURRENT_PC_BP_SP; 84 (void)sp; 85 return asan_malloc_usable_size(ptr, pc, bp); 86} 87 88// We avoid including malloc.h for portability reasons. 89// man mallinfo says the fields are "long", but the implementation uses int. 90// It doesn't matter much -- we just need to make sure that the libc's mallinfo 91// is not called. 92struct fake_mallinfo { 93 int x[10]; 94}; 95 96INTERCEPTOR(struct fake_mallinfo, mallinfo, void) { 97 struct fake_mallinfo res; 98 REAL(memset)(&res, 0, sizeof(res)); 99 return res; 100} 101 102INTERCEPTOR(int, mallopt, int cmd, int value) { 103 return -1; 104} 105 106INTERCEPTOR(int, posix_memalign, void **memptr, uptr alignment, uptr size) { 107 GET_STACK_TRACE_MALLOC; 108 // Printf("posix_memalign: %zx %zu\n", alignment, size); 109 return asan_posix_memalign(memptr, alignment, size, &stack); 110} 111 112INTERCEPTOR(void*, valloc, uptr size) { 113 GET_STACK_TRACE_MALLOC; 114 return asan_valloc(size, &stack); 115} 116 117INTERCEPTOR(void*, pvalloc, uptr size) { 118 GET_STACK_TRACE_MALLOC; 119 return asan_pvalloc(size, &stack); 120} 121 122INTERCEPTOR(void, malloc_stats, void) { 123 __asan_print_accumulated_stats(); 124} 125 126#if SANITIZER_ANDROID 127// Format of __libc_malloc_dispatch has changed in Android L. 128// While we are moving towards a solution that does not depend on bionic 129// internals, here is something to support both K* and L releases. 130struct MallocDebugK { 131 void *(*malloc)(uptr bytes); 132 void (*free)(void *mem); 133 void *(*calloc)(uptr n_elements, uptr elem_size); 134 void *(*realloc)(void *oldMem, uptr bytes); 135 void *(*memalign)(uptr alignment, uptr bytes); 136 uptr (*malloc_usable_size)(void *mem); 137}; 138 139struct MallocDebugL { 140 void *(*calloc)(uptr n_elements, uptr elem_size); 141 void (*free)(void *mem); 142 fake_mallinfo (*mallinfo)(void); 143 void *(*malloc)(uptr bytes); 144 uptr (*malloc_usable_size)(void *mem); 145 void *(*memalign)(uptr alignment, uptr bytes); 146 int (*posix_memalign)(void **memptr, uptr alignment, uptr size); 147 void* (*pvalloc)(uptr size); 148 void *(*realloc)(void *oldMem, uptr bytes); 149 void* (*valloc)(uptr size); 150}; 151 152ALIGNED(32) const MallocDebugK asan_malloc_dispatch_k = { 153 WRAP(malloc), WRAP(free), WRAP(calloc), 154 WRAP(realloc), WRAP(memalign), WRAP(malloc_usable_size)}; 155 156ALIGNED(32) const MallocDebugL asan_malloc_dispatch_l = { 157 WRAP(calloc), WRAP(free), WRAP(mallinfo), 158 WRAP(malloc), WRAP(malloc_usable_size), WRAP(memalign), 159 WRAP(posix_memalign), WRAP(pvalloc), WRAP(realloc), 160 WRAP(valloc)}; 161 162namespace __asan { 163void ReplaceSystemMalloc() { 164 void **__libc_malloc_dispatch_p = 165 (void **)AsanDlSymNext("__libc_malloc_dispatch"); 166 if (__libc_malloc_dispatch_p) { 167 // Decide on K vs L dispatch format by the presence of 168 // __libc_malloc_default_dispatch export in libc. 169 void *default_dispatch_p = AsanDlSymNext("__libc_malloc_default_dispatch"); 170 if (default_dispatch_p) 171 *__libc_malloc_dispatch_p = (void *)&asan_malloc_dispatch_k; 172 else 173 *__libc_malloc_dispatch_p = (void *)&asan_malloc_dispatch_l; 174 } 175} 176} // namespace __asan 177 178#else // SANITIZER_ANDROID 179 180namespace __asan { 181void ReplaceSystemMalloc() { 182} 183} // namespace __asan 184#endif // SANITIZER_ANDROID 185 186#endif // SANITIZER_FREEBSD || SANITIZER_LINUX 187