blob: 243ea1ffb5f33193dd30842c5e0c8ac4076a7ad5 [file] [log] [blame]
/*
Make sure that leak-check's pointer tracing avoids traps, i.e. tricky
memory areas where it could crash if not careful.
*/
#include <stdio.h>
#include "memcheck/memcheck.h"
#include "tests/sys_mman.h"
#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>
#if !defined(MAP_NORESERVE)
# define MAP_NORESERVE 0
#endif
int main()
{
char **volatile ptrs;
int i;
int fd;
char *map;
/* I _think_ the point of this is to fill ptrs with a pointer
to every 4th page in the entire address space, hence
guaranteeing that at least one of them points into one of
the below traps, and so checks that the leak checker
doesn't bomb when following them. That's fine on 32-bit
platforms, but hopeless for a 64-bit system. So the
following settings do achieve that on a 32-bit target but
merely make a 64-bit target give the same output without
properly testing it. */
int ptrbits, stepbits, stepsize, nptrs;
if (sizeof(void*) == 8) {
/* 64-bit machine */
ptrbits = 32; //bogus
stepbits = 14+1; //bogus
stepsize = (1 << stepbits);
nptrs = 1 << (ptrbits - stepbits);
} else {
/* 32-bit machine */
ptrbits = 32;
stepbits = 14;
stepsize = (1 << stepbits);
nptrs = 1 << (ptrbits - stepbits);
}
ptrs = malloc(nptrs * sizeof(char *));
for (i = 0; i < nptrs; i++)
ptrs[i] = (char *)((long)i << stepbits);
/* lay some traps */
/* non-RWX memory, and MAP_NORESERVE if present */
map = mmap(0, stepsize * 2, PROT_NONE, MAP_PRIVATE|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0);
if (map == (char *)-1)
perror("trap 1 failed");
/* write-only memory, and MAP_NORESERVE if supported */
map = mmap(0, stepsize * 2, PROT_WRITE, MAP_PRIVATE|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0);
if (map == (char *)-1)
perror("trap 2 failed");
/* non-zero mmap of a zero-length file -> SIGBUS */
fd = open("./pointer-trace-test-file", O_RDWR | O_CREAT | O_EXCL, 0600);
unlink("./pointer-trace-test-file");
map = mmap(0, stepsize * 2, PROT_WRITE|PROT_READ, MAP_PRIVATE, fd, 0);
if (map == (char *)-1)
perror("trap 3 failed");
//printf("trap 3 = %p-%p\n", map, map+stepsize*2);
/* unmapped memory that's marked as defined */
map = mmap(0, 256*1024, PROT_NONE, MAP_PRIVATE|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0);
if (map == (char *)-1)
perror("trap 4 failed");
else {
munmap(map, 256*1024);
VALGRIND_MAKE_MEM_DEFINED(map, 256*1024); /* great big fat lie */
}
VALGRIND_DO_LEAK_CHECK;
free(ptrs);
// We deliberately make a leak, it'll be obvious if something went
// wrong because the message won't be printed.
ptrs = malloc(1000);
return 0;
}