// Regression test for a bug in malloc_create_zone() // (https://code.google.com/p/address-sanitizer/issues/detail?id=203) // The old implementation of malloc_create_zone() didn't always return a // page-aligned address, so we can only test on a best-effort basis. // RUN: %clangxx_asan %s -o %t // RUN: %run %t 2>&1 #include <malloc/malloc.h> #include <stdlib.h> #include <string.h> #include <stdio.h> const int kNumIter = 4096; const int kNumZones = 100; int main() { char *mem[kNumIter * 2]; // Allocate memory chunks from different size classes up to 1 page. // (For the case malloc() returns memory chunks in descending order) for (int i = 0; i < kNumIter; i++) { mem[i] = (char*)malloc(8 * i); } // Try to allocate a page-aligned malloc zone. Otherwise the mprotect() call // in malloc_set_zone_name() will silently fail. malloc_zone_t *zone = NULL; bool aligned = false; for (int i = 0; i < kNumZones; i++) { zone = malloc_create_zone(0, 0); if (((uintptr_t)zone & (~0xfff)) == (uintptr_t)zone) { aligned = true; break; } } if (!aligned) { printf("Warning: couldn't allocate a page-aligned zone."); return 0; } // malloc_set_zone_name() calls mprotect(zone, 4096, PROT_READ | PROT_WRITE), // modifies the zone contents and then calls mprotect(zone, 4096, PROT_READ). malloc_set_zone_name(zone, "foobar"); // Allocate memory chunks from different size classes again. for (int i = 0; i < kNumIter; i++) { mem[i + kNumIter] = (char*)malloc(8 * i); } // Access the allocated memory chunks and free them. for (int i = 0; i < kNumIter * 2; i++) { memset(mem[i], 'a', 8 * (i % kNumIter)); free(mem[i]); } return 0; }