src/regression/malloc-brk-fail.c

   1 // commit 5446303328adf4b4e36d9fba21848e6feb55fab4 2014-04-02
   2 // malloc should not fail if brk fails but mmap can still allocate
   3 #include <stdlib.h>
   4 #include <errno.h>
   5 #include <string.h>
   6 #include <sys/mman.h>
   7 #include <sys/resource.h>
   8 #include "test.h"
   9
  10 #define T(f) ((f)==0 || (t_error(#f " failed: %s\n", strerror(errno)), 0))
  11
  12 int main(void)
  13 {
  14         void *p;
  15         void *q;
  16         size_t n;
  17         int r;
  18
  19         // fill memory, largest mmaped area is [p,p+n)
  20         if (t_vmfill(&p, &n, 1) < 1 || n < 2*65536) {
  21                 t_error("vmfill failed\n");
  22                 return 1;
  23         }
  24
  25         // malloc should fail here
  26         errno = 0;
  27         q = malloc(10000);
  28         if (q)
  29                 t_error("malloc(10000) succeeded after memory is filled\n");
  30         else if (errno != ENOMEM)
  31                 t_error("malloc did not fail with ENOMEM, got %s\n", strerror(errno));
  32
  33         // make space available for mmap, but ensure it's not contiguous with brk
  34         T(munmap((char*)p+65536, n-65536));
  35
  36         // malloc should succeed now
  37         q = malloc(10000);
  38         if (!q)
  39                 t_error("malloc(10000) failed (eventhough 64k is available to mmap): %s\n", strerror(errno));
  40
  41         return t_status;
  42 }