1// Regression test for a bug in malloc_create_zone()
2// (https://code.google.com/p/address-sanitizer/issues/detail?id=203)
3// The old implementation of malloc_create_zone() didn't always return a
4// page-aligned address, so we can only test on a best-effort basis.
5
6// RUN: %clangxx_asan %s -o %t
7// RUN: %run %t 2>&1
8
9#include <malloc/malloc.h>
10#include <stdlib.h>
11#include <string.h>
12#include <stdio.h>
13
14const int kNumIter = 4096;
15const int kNumZones = 100;
16int main() {
17  char *mem[kNumIter * 2];
18  // Allocate memory chunks from different size classes up to 1 page.
19  // (For the case malloc() returns memory chunks in descending order)
20  for (int i = 0; i < kNumIter; i++) {
21    mem[i] = (char*)malloc(8 * i);
22  }
23  // Try to allocate a page-aligned malloc zone. Otherwise the mprotect() call
24  // in malloc_set_zone_name() will silently fail.
25  malloc_zone_t *zone = NULL;
26  bool aligned = false;
27  for (int i = 0; i < kNumZones; i++) {
28    zone = malloc_create_zone(0, 0);
29    if (((uintptr_t)zone & (~0xfff)) == (uintptr_t)zone) {
30      aligned = true;
31      break;
32    }
33  }
34  if (!aligned) {
35    printf("Warning: couldn't allocate a page-aligned zone.");
36    return 0;
37  }
38  // malloc_set_zone_name() calls mprotect(zone, 4096, PROT_READ | PROT_WRITE),
39  // modifies the zone contents and then calls mprotect(zone, 4096, PROT_READ).
40  malloc_set_zone_name(zone, "foobar");
41  // Allocate memory chunks from different size classes again.
42  for (int i = 0; i < kNumIter; i++) {
43    mem[i + kNumIter] = (char*)malloc(8 * i);
44  }
45  // Access the allocated memory chunks and free them.
46  for (int i = 0; i < kNumIter * 2; i++) {
47    memset(mem[i], 'a', 8 * (i % kNumIter));
48    free(mem[i]);
49  }
50  return 0;
51}
52