blob: bcd7974a4a7e0a036a28d84ce9e0f6ff111a41f3 [file] [log] [blame]
/* Copyright (c) 2014, Google Inc.
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
* OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
#include <openssl/base.h>
#if defined(__GLIBC__) && !defined(__UCLIBC__)
#define OPENSSL_GLIBC
#endif
// This file isn't built on ARM or Aarch64 because we link statically in those
// builds and trying to override malloc in a static link doesn't work. It also
// requires glibc. It's also disabled on ASan builds as this interferes with
// ASan's malloc interceptor.
//
// TODO(davidben): See if this and ASan's and MSan's interceptors can be made to
// coexist.
#if defined(__linux__) && defined(OPENSSL_GLIBC) && !defined(OPENSSL_ARM) && \
!defined(OPENSSL_AARCH64) && !defined(OPENSSL_ASAN) && \
!defined(OPENSSL_MSAN)
#include <errno.h>
#include <signal.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <new>
// This file defines overrides for the standard allocation functions that allow
// a given allocation to be made to fail for testing. If the program is run
// with MALLOC_NUMBER_TO_FAIL set to a base-10 number then that allocation will
// return NULL. If MALLOC_BREAK_ON_FAIL is also defined then the allocation
// will signal SIGTRAP rather than return NULL.
//
// This code is not thread safe.
static uint64_t current_malloc_count = 0;
static uint64_t malloc_number_to_fail = 0;
static bool failure_enabled = false, break_on_fail = false, in_call = false;
extern "C" {
// These are other names for the standard allocation functions.
extern void *__libc_malloc(size_t size);
extern void *__libc_calloc(size_t num_elems, size_t size);
extern void *__libc_realloc(void *ptr, size_t size);
}
static void exit_handler(void) {
if (failure_enabled && current_malloc_count > malloc_number_to_fail) {
_exit(88);
}
}
static void cpp_new_handler() {
// Return to try again. It won't fail a second time.
return;
}
// should_fail_allocation returns true if the current allocation should fail.
static bool should_fail_allocation() {
static bool init = false;
if (in_call) {
return false;
}
in_call = true;
if (!init) {
const char *env = getenv("MALLOC_NUMBER_TO_FAIL");
if (env != NULL && env[0] != 0) {
char *endptr;
malloc_number_to_fail = strtoull(env, &endptr, 10);
if (*endptr == 0) {
failure_enabled = true;
atexit(exit_handler);
std::set_new_handler(cpp_new_handler);
}
}
break_on_fail = (NULL != getenv("MALLOC_BREAK_ON_FAIL"));
init = true;
}
in_call = false;
if (!failure_enabled) {
return false;
}
bool should_fail = (current_malloc_count == malloc_number_to_fail);
current_malloc_count++;
if (should_fail && break_on_fail) {
raise(SIGTRAP);
}
return should_fail;
}
extern "C" {
void *malloc(size_t size) {
if (should_fail_allocation()) {
errno = ENOMEM;
return NULL;
}
return __libc_malloc(size);
}
void *calloc(size_t num_elems, size_t size) {
if (should_fail_allocation()) {
errno = ENOMEM;
return NULL;
}
return __libc_calloc(num_elems, size);
}
void *realloc(void *ptr, size_t size) {
if (should_fail_allocation()) {
errno = ENOMEM;
return NULL;
}
return __libc_realloc(ptr, size);
}
} // extern "C"
#endif /* defined(linux) && GLIBC && !ARM && !AARCH64 && !ASAN */