compiler-rt/test/scudo/secondary.c

   1 // RUN: %clang_scudo %s -o %t
   2 // RUN: %run %t after  2>&1 | FileCheck %s
   3 // RUN: %run %t before 2>&1 | FileCheck %s
   4
   5 // Test that we hit a guard page when writing past the end of a chunk
   6 // allocated by the Secondary allocator, or writing too far in front of it.
   7
   8 #include <assert.h>
   9 #include <malloc.h>
  10 #include <signal.h>
  11 #include <stdlib.h>
  12 #include <string.h>
  13 #include <unistd.h>
  14
  15 void handler(int signo, siginfo_t *info, void *uctx) {
  16   if (info->si_code == SEGV_ACCERR) {
  17     fprintf(stderr, "SCUDO SIGSEGV\n");
  18     exit(0);
  19   }
  20   exit(1);
  21 }
  22
  23 int main(int argc, char **argv) {
  24   // The size must be large enough to be serviced by the secondary allocator.
  25   long page_size = sysconf(_SC_PAGESIZE);
  26   size_t size = (1U << 17) + page_size;
  27   struct sigaction a;
  28
  29   assert(argc == 2);
  30   memset(&a, 0, sizeof(a));
  31   a.sa_sigaction = handler;
  32   a.sa_flags = SA_SIGINFO;
  33
  34   char *p = (char *)malloc(size);
  35   assert(p);
  36   memset(p, 'A', size); // This should not trigger anything.
  37   // Set up the SIGSEGV handler now, as the rest should trigger an AV.
  38   sigaction(SIGSEGV, &a, NULL);
  39   if (!strcmp(argv[1], "after")) {
  40     for (int i = 0; i < page_size; i++)
  41       p[size + i] = 'A';
  42   }
  43   if (!strcmp(argv[1], "before")) {
  44     for (int i = 1; i < page_size; i++)
  45       p[-i] = 'A';
  46   }
  47   free(p);
  48
  49   return 1; // A successful test means we shouldn't reach this.
  50 }
  51
  52 // CHECK: SCUDO SIGSEGV