compiler-rt/test/scudo/realloc.cpp

   1 // RUN: %clangxx_scudo %s -lstdc++ -o %t
   2 // RUN: %run %t pointers   2>&1
   3 // RUN: %run %t contents   2>&1
   4 // RUN: %run %t usablesize 2>&1
   5
   6 // Tests that our reallocation function returns the same pointer when the
   7 // requested size can fit into the previously allocated chunk. Also tests that
   8 // a new chunk is returned if the size is greater, and that the contents of the
   9 // chunk are left unchanged. Finally, checks that realloc copies the usable
  10 // size of the old chunk to the new one (as opposed to the requested size).
  11
  12 #include <assert.h>
  13 #include <malloc.h>
  14 #include <string.h>
  15
  16 #include <vector>
  17
  18 #include <sanitizer/allocator_interface.h>
  19
  20 int main(int argc, char **argv) {
  21   void *p, *old_p;
  22   // Those sizes will exercise both allocators (Primary & Secondary).
  23   std::vector<size_t> sizes{1, 16, 1024, 32768, 1 << 16, 1 << 17, 1 << 20};
  24
  25   assert(argc == 2);
  26
  27   if (!strcmp(argv[1], "usablesize")) {
  28     // This tests a sketchy behavior inherited from poorly written libraries
  29     // that have become somewhat standard. When realloc'ing a chunk, the
  30     // copied contents should span the usable size of the chunk, not the
  31     // requested size.
  32     size_t size = 496, usable_size;
  33     p = nullptr;
  34     // Make sure we get a chunk with a usable size actually larger than size.
  35     do {
  36       if (p)
  37         free(p);
  38       size += 16;
  39       p = malloc(size);
  40       usable_size = __sanitizer_get_allocated_size(p);
  41       assert(usable_size >= size);
  42     } while (usable_size == size);
  43     for (int i = 0; i < usable_size; i++)
  44       reinterpret_cast<char *>(p)[i] = 'A';
  45     old_p = p;
  46     // Make sure we get a different chunk so that the data is actually copied.
  47     do {
  48       size *= 2;
  49       p = realloc(p, size);
  50       assert(p);
  51     } while (p == old_p);
  52     // The contents of the new chunk must match the old one up to usable_size.
  53     for (int i = 0; i < usable_size; i++)
  54       assert(reinterpret_cast<char *>(p)[i] == 'A');
  55     free(p);
  56   } else {
  57     for (size_t size : sizes) {
  58       if (!strcmp(argv[1], "pointers")) {
  59         old_p = p = realloc(nullptr, size);
  60         assert(p);
  61         size = __sanitizer_get_allocated_size(p);
  62         // Our realloc implementation will return the same pointer if the size
  63         // requested is lower than or equal to the usable size of the associated
  64         // chunk.
  65         p = realloc(p, size - 1);
  66         assert(p == old_p);
  67         p = realloc(p, size);
  68         assert(p == old_p);
  69         // And a new one if the size is greater.
  70         p = realloc(p, size + 1);
  71         assert(p != old_p);
  72         // A size of 0 will free the chunk and return nullptr.
  73         p = realloc(p, 0);
  74         assert(!p);
  75         old_p = nullptr;
  76       }
  77       if (!strcmp(argv[1], "contents")) {
  78         p = realloc(nullptr, size);
  79         assert(p);
  80         for (int i = 0; i < size; i++)
  81           reinterpret_cast<char *>(p)[i] = 'A';
  82         p = realloc(p, size + 1);
  83         // The contents of the reallocated chunk must match the original one.
  84         for (int i = 0; i < size; i++)
  85           assert(reinterpret_cast<char *>(p)[i] == 'A');
  86       }
  87     }
  88   }
  89   return 0;
  90 }
  91
  92 // CHECK: ERROR: invalid chunk type when reallocating address