libsanitizer/asan/asan_malloc_linux.cc

   1 //===-- asan_malloc_linux.cc ----------------------------------------------===//
   2 //
   3 // This file is distributed under the University of Illinois Open Source
   4 // License. See LICENSE.TXT for details.
   5 //
   6 //===----------------------------------------------------------------------===//
   7 //
   8 // This file is a part of AddressSanitizer, an address sanity checker.
   9 //
  10 // Linux-specific malloc interception.
  11 // We simply define functions like malloc, free, realloc, etc.
  12 // They will replace the corresponding libc functions automagically.
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "sanitizer_common/sanitizer_platform.h"
  16 #if SANITIZER_FREEBSD || SANITIZER_LINUX
  17
  18 #include "sanitizer_common/sanitizer_tls_get_addr.h"
  19 #include "asan_allocator.h"
  20 #include "asan_interceptors.h"
  21 #include "asan_internal.h"
  22 #include "asan_stack.h"
  23
  24 // ---------------------- Replacement functions ---------------- {{{1
  25 using namespace __asan;  // NOLINT
  26
  27 static uptr allocated_for_dlsym;
  28 static const uptr kDlsymAllocPoolSize = 1024;
  29 static uptr alloc_memory_for_dlsym[kDlsymAllocPoolSize];
  30
  31 static bool IsInDlsymAllocPool(const void *ptr) {
  32   uptr off = (uptr)ptr - (uptr)alloc_memory_for_dlsym;
  33   return off < sizeof(alloc_memory_for_dlsym);
  34 }
  35
  36 static void *AllocateFromLocalPool(uptr size_in_bytes) {
  37   uptr size_in_words = RoundUpTo(size_in_bytes, kWordSize) / kWordSize;
  38   void *mem = (void*)&alloc_memory_for_dlsym[allocated_for_dlsym];
  39   allocated_for_dlsym += size_in_words;
  40   CHECK_LT(allocated_for_dlsym, kDlsymAllocPoolSize);
  41   return mem;
  42 }
  43
  44 INTERCEPTOR(void, free, void *ptr) {
  45   GET_STACK_TRACE_FREE;
  46   if (UNLIKELY(IsInDlsymAllocPool(ptr)))
  47     return;
  48   asan_free(ptr, &stack, FROM_MALLOC);
  49 }
  50
  51 INTERCEPTOR(void, cfree, void *ptr) {
  52   GET_STACK_TRACE_FREE;
  53   if (UNLIKELY(IsInDlsymAllocPool(ptr)))
  54     return;
  55   asan_free(ptr, &stack, FROM_MALLOC);
  56 }
  57
  58 INTERCEPTOR(void*, malloc, uptr size) {
  59   if (UNLIKELY(!asan_inited))
  60     // Hack: dlsym calls malloc before REAL(malloc) is retrieved from dlsym.
  61     return AllocateFromLocalPool(size);
  62   GET_STACK_TRACE_MALLOC;
  63   return asan_malloc(size, &stack);
  64 }
  65
  66 INTERCEPTOR(void*, calloc, uptr nmemb, uptr size) {
  67   if (UNLIKELY(!asan_inited))
  68     // Hack: dlsym calls calloc before REAL(calloc) is retrieved from dlsym.
  69     return AllocateFromLocalPool(nmemb * size);
  70   GET_STACK_TRACE_MALLOC;
  71   return asan_calloc(nmemb, size, &stack);
  72 }
  73
  74 INTERCEPTOR(void*, realloc, void *ptr, uptr size) {
  75   GET_STACK_TRACE_MALLOC;
  76   if (UNLIKELY(IsInDlsymAllocPool(ptr))) {
  77     uptr offset = (uptr)ptr - (uptr)alloc_memory_for_dlsym;
  78     uptr copy_size = Min(size, kDlsymAllocPoolSize - offset);
  79     void *new_ptr = asan_malloc(size, &stack);
  80     internal_memcpy(new_ptr, ptr, copy_size);
  81     return new_ptr;
  82   }
  83   return asan_realloc(ptr, size, &stack);
  84 }
  85
  86 INTERCEPTOR(void*, memalign, uptr boundary, uptr size) {
  87   GET_STACK_TRACE_MALLOC;
  88   return asan_memalign(boundary, size, &stack, FROM_MALLOC);
  89 }
  90
  91 INTERCEPTOR(void*, aligned_alloc, uptr boundary, uptr size) {
  92   GET_STACK_TRACE_MALLOC;
  93   return asan_memalign(boundary, size, &stack, FROM_MALLOC);
  94 }
  95
  96 INTERCEPTOR(void*, __libc_memalign, uptr boundary, uptr size) {
  97   GET_STACK_TRACE_MALLOC;
  98   void *res = asan_memalign(boundary, size, &stack, FROM_MALLOC);
  99   DTLS_on_libc_memalign(res, size * boundary);
 100   return res;
 101 }
 102
 103 INTERCEPTOR(uptr, malloc_usable_size, void *ptr) {
 104   GET_CURRENT_PC_BP_SP;
 105   (void)sp;
 106   return asan_malloc_usable_size(ptr, pc, bp);
 107 }
 108
 109 // We avoid including malloc.h for portability reasons.
 110 // man mallinfo says the fields are "long", but the implementation uses int.
 111 // It doesn't matter much -- we just need to make sure that the libc's mallinfo
 112 // is not called.
 113 struct fake_mallinfo {
 114   int x[10];
 115 };
 116
 117 INTERCEPTOR(struct fake_mallinfo, mallinfo, void) {
 118   struct fake_mallinfo res;
 119   REAL(memset)(&res, 0, sizeof(res));
 120   return res;
 121 }
 122
 123 INTERCEPTOR(int, mallopt, int cmd, int value) {
 124   return -1;
 125 }
 126
 127 INTERCEPTOR(int, posix_memalign, void **memptr, uptr alignment, uptr size) {
 128   GET_STACK_TRACE_MALLOC;
 129   // Printf("posix_memalign: %zx %zu\n", alignment, size);
 130   return asan_posix_memalign(memptr, alignment, size, &stack);
 131 }
 132
 133 INTERCEPTOR(void*, valloc, uptr size) {
 134   GET_STACK_TRACE_MALLOC;
 135   return asan_valloc(size, &stack);
 136 }
 137
 138 INTERCEPTOR(void*, pvalloc, uptr size) {
 139   GET_STACK_TRACE_MALLOC;
 140   return asan_pvalloc(size, &stack);
 141 }
 142
 143 INTERCEPTOR(void, malloc_stats, void) {
 144   __asan_print_accumulated_stats();
 145 }
 146
 147 #if SANITIZER_ANDROID
 148 // Format of __libc_malloc_dispatch has changed in Android L.
 149 // While we are moving towards a solution that does not depend on bionic
 150 // internals, here is something to support both K* and L releases.
 151 struct MallocDebugK {
 152   void *(*malloc)(uptr bytes);
 153   void (*free)(void *mem);
 154   void *(*calloc)(uptr n_elements, uptr elem_size);
 155   void *(*realloc)(void *oldMem, uptr bytes);
 156   void *(*memalign)(uptr alignment, uptr bytes);
 157   uptr (*malloc_usable_size)(void *mem);
 158 };
 159
 160 struct MallocDebugL {
 161   void *(*calloc)(uptr n_elements, uptr elem_size);
 162   void (*free)(void *mem);
 163   fake_mallinfo (*mallinfo)(void);
 164   void *(*malloc)(uptr bytes);
 165   uptr (*malloc_usable_size)(void *mem);
 166   void *(*memalign)(uptr alignment, uptr bytes);
 167   int (*posix_memalign)(void **memptr, uptr alignment, uptr size);
 168   void* (*pvalloc)(uptr size);
 169   void *(*realloc)(void *oldMem, uptr bytes);
 170   void* (*valloc)(uptr size);
 171 };
 172
 173 ALIGNED(32) const MallocDebugK asan_malloc_dispatch_k = {
 174     WRAP(malloc),  WRAP(free),     WRAP(calloc),
 175     WRAP(realloc), WRAP(memalign), WRAP(malloc_usable_size)};
 176
 177 ALIGNED(32) const MallocDebugL asan_malloc_dispatch_l = {
 178     WRAP(calloc),         WRAP(free),               WRAP(mallinfo),
 179     WRAP(malloc),         WRAP(malloc_usable_size), WRAP(memalign),
 180     WRAP(posix_memalign), WRAP(pvalloc),            WRAP(realloc),
 181     WRAP(valloc)};
 182
 183 namespace __asan {
 184 void ReplaceSystemMalloc() {
 185   void **__libc_malloc_dispatch_p =
 186       (void **)AsanDlSymNext("__libc_malloc_dispatch");
 187   if (__libc_malloc_dispatch_p) {
 188     // Decide on K vs L dispatch format by the presence of
 189     // __libc_malloc_default_dispatch export in libc.
 190     void *default_dispatch_p = AsanDlSymNext("__libc_malloc_default_dispatch");
 191     if (default_dispatch_p)
 192       *__libc_malloc_dispatch_p = (void *)&asan_malloc_dispatch_k;
 193     else
 194       *__libc_malloc_dispatch_p = (void *)&asan_malloc_dispatch_l;
 195   }
 196 }
 197 }  // namespace __asan
 198
 199 #else  // SANITIZER_ANDROID
 200
 201 namespace __asan {
 202 void ReplaceSystemMalloc() {
 203 }
 204 }  // namespace __asan
 205 #endif  // SANITIZER_ANDROID
 206
 207 #endif  // SANITIZER_FREEBSD || SANITIZER_LINUX