compiler-rt/test/hwasan/TestCases/munmap.c

   1 // RUN: %clang_hwasan  %s -o %t
   2 // RUN: %run %t 1 2>&1
   3 // RUN: %run %t 2 2>&1
   4
   5 // REQUIRES: pointer-tagging
   6
   7 #include <sanitizer/hwasan_interface.h>
   8 #include <stdio.h>
   9 #include <stdlib.h>
  10 #include <sys/mman.h>
  11 #include <unistd.h>
  12
  13 int main(int argc, char **argv) {
  14   const size_t kPS = sysconf(_SC_PAGESIZE);
  15   const int kSize = kPS / atoi(argv[1]);
  16   const int kTag = 47;
  17
  18   // Get any mmaped pointer.
  19   void *r =
  20       mmap(0, kSize, PROT_READ | PROT_WRITE, MAP_ANON | MAP_PRIVATE, -1, 0);
  21   if (r == MAP_FAILED) {
  22     perror("Failed to mmap: ");
  23     abort();
  24   }
  25
  26   // Check that the pointer is untagged.
  27   if (r != __hwasan_tag_pointer(r, 0)) {
  28     fprintf(stderr, "Pointer returned by mmap should be untagged.\n");
  29     abort();
  30   }
  31
  32   // Manually tag the pointer and the memory.
  33   __hwasan_tag_memory(r, kTag, kPS);
  34   int *p1 = __hwasan_tag_pointer(r, kTag);
  35
  36   // Check that the pointer and the tag match.
  37   if (__hwasan_test_shadow(p1, kPS) != -1) {
  38     fprintf(stderr, "Failed to tag.\n");
  39     abort();
  40   }
  41
  42   if (munmap((char *)r + 1, kSize) == 0) {
  43     perror("munmap should fail: ");
  44     abort();
  45   }
  46
  47   if (__hwasan_test_shadow(p1, kPS) != -1) {
  48     fprintf(stderr, "Still must be tagged.\n");
  49     abort();
  50   }
  51
  52   // First munmmap and then mmap the same pointer using MAP_FIXED.
  53   if (munmap((char *)r, kSize) != 0) {
  54     perror("Failed to unmap: ");
  55     abort();
  56   }
  57
  58   if (__hwasan_test_shadow(r, kPS) != -1) {
  59     fprintf(stderr, "Shadow memory was not cleaned by munmap.\n");
  60     abort();
  61   }
  62   __hwasan_tag_memory(r, kTag, kPS);
  63   int *p2 = (int *)mmap(r, kSize, PROT_READ | PROT_WRITE,
  64                         MAP_FIXED | MAP_ANON | MAP_PRIVATE, -1, 0);
  65
  66   // Check that the pointer has no tag in it.
  67   if (p2 != r) {
  68     fprintf(stderr, "The mmap pointer has a non-zero tag in it.\n");
  69     abort();
  70   }
  71
  72   // Make sure we can access the shadow with an untagged pointer.
  73   if (__hwasan_test_shadow(p2, kPS) != -1) {
  74     fprintf(stderr, "Shadow memory was not cleaned by mmap.\n");
  75     abort();
  76   }
  77   return 0;
  78 }