libmudflap/testsuite/libmudflap.c/fail40-frag.c

   1 /* Test proper lookup-uncaching of large objects */
   2 #include "../config.h"
   3
   4 #include <unistd.h>
   5 #include <string.h>
   6 #include <stdio.h>
   7 #include <stdlib.h>
   8 #ifdef HAVE_SYS_MMAN_H
   9 #include <sys/mman.h>
  10 #endif
  11
  12 int main ()
  13 {
  14 #ifndef MAP_ANONYMOUS
  15 #define MAP_ANONYMOUS MAP_ANON
  16 #endif
  17 #ifdef HAVE_MMAP
  18   volatile unsigned char *p;
  19   unsigned num = getpagesize ();
  20   unsigned i;
  21   int rc;
  22
  23   /* Get a bit of usable address space.  We really want an 2**N+1-sized object,
  24      so the low/high addresses wrap when hashed into the lookup cache.  So we
  25      will manually unregister the entire mmap, then re-register a slice.  */
  26   p = mmap (NULL, num, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, 0, 0);
  27   if (p == NULL)
  28     return 1;
  29   /* Now unregister it, as if munmap was called.  But don't actually munmap, so
  30      we can write into the memory.  */
  31   __mf_unregister ((void *) p, num, __MF_TYPE_HEAP_I);
  32
  33   /* Now register it under a slightly inflated, 2**N+1 size.  */
  34   __mf_register ((void *) p, num+1, __MF_TYPE_HEAP_I, "fake mmap registration");
  35
  36   /* Traverse array to ensure that entire lookup cache is made to point at it.  */
  37   for (i=0; i<num; i++)
  38     p[i] = 0;
  39
  40   /* Unregister it.  This should clear the entire lookup cache, even though
  41      hash(low) == hash (high)  (and probably == 0) */
  42   __mf_unregister ((void *) p, num+1, __MF_TYPE_HEAP_I);
  43
  44   /* Now touch the middle portion of the ex-array.  If the lookup cache was
  45      well and truly cleaned, then this access should trap.  */
  46   p[num/2] = 1;
  47
  48   return 0;
  49 #else
  50   return 1;
  51 #endif
  52 }
  53 /* { dg-output "mudflap violation 1.*check/write.*" } */
  54 /* { dg-output "Nearby object 1.*" } */
  55 /* { dg-output "mudflap dead object.*fake mmap registration.*" } */
  56 /* { dg-do run { xfail *-*-* } } */