xref: /aosp_15_r20/external/webrtc/rtc_base/zero_memory.cc (revision d9f758449e529ab9291ac668be2861e7a55c2422)
1*d9f75844SAndroid Build Coastguard Worker /*
2*d9f75844SAndroid Build Coastguard Worker  *  Copyright 2017 The WebRTC Project Authors. All rights reserved.
3*d9f75844SAndroid Build Coastguard Worker  *
4*d9f75844SAndroid Build Coastguard Worker  *  Use of this source code is governed by a BSD-style license
5*d9f75844SAndroid Build Coastguard Worker  *  that can be found in the LICENSE file in the root of the source
6*d9f75844SAndroid Build Coastguard Worker  *  tree. An additional intellectual property rights grant can be found
7*d9f75844SAndroid Build Coastguard Worker  *  in the file PATENTS.  All contributing project authors may
8*d9f75844SAndroid Build Coastguard Worker  *  be found in the AUTHORS file in the root of the source tree.
9*d9f75844SAndroid Build Coastguard Worker  */
10*d9f75844SAndroid Build Coastguard Worker 
11*d9f75844SAndroid Build Coastguard Worker #if defined(WEBRTC_WIN)
12*d9f75844SAndroid Build Coastguard Worker #include <windows.h>
13*d9f75844SAndroid Build Coastguard Worker #else
14*d9f75844SAndroid Build Coastguard Worker #include <string.h>
15*d9f75844SAndroid Build Coastguard Worker #endif
16*d9f75844SAndroid Build Coastguard Worker 
17*d9f75844SAndroid Build Coastguard Worker #include "rtc_base/checks.h"
18*d9f75844SAndroid Build Coastguard Worker #include "rtc_base/zero_memory.h"
19*d9f75844SAndroid Build Coastguard Worker 
20*d9f75844SAndroid Build Coastguard Worker namespace rtc {
21*d9f75844SAndroid Build Coastguard Worker 
22*d9f75844SAndroid Build Coastguard Worker // Code and comment taken from "OPENSSL_cleanse" of BoringSSL.
ExplicitZeroMemory(void * ptr,size_t len)23*d9f75844SAndroid Build Coastguard Worker void ExplicitZeroMemory(void* ptr, size_t len) {
24*d9f75844SAndroid Build Coastguard Worker   RTC_DCHECK(ptr || !len);
25*d9f75844SAndroid Build Coastguard Worker #if defined(WEBRTC_WIN)
26*d9f75844SAndroid Build Coastguard Worker   SecureZeroMemory(ptr, len);
27*d9f75844SAndroid Build Coastguard Worker #else
28*d9f75844SAndroid Build Coastguard Worker   memset(ptr, 0, len);
29*d9f75844SAndroid Build Coastguard Worker #if !defined(__pnacl__)
30*d9f75844SAndroid Build Coastguard Worker   /* As best as we can tell, this is sufficient to break any optimisations that
31*d9f75844SAndroid Build Coastguard Worker      might try to eliminate "superfluous" memsets. If there's an easy way to
32*d9f75844SAndroid Build Coastguard Worker      detect memset_s, it would be better to use that. */
33*d9f75844SAndroid Build Coastguard Worker   __asm__ __volatile__("" : : "r"(ptr) : "memory");  // NOLINT
34*d9f75844SAndroid Build Coastguard Worker #endif
35*d9f75844SAndroid Build Coastguard Worker #endif  // !WEBRTC_WIN
36*d9f75844SAndroid Build Coastguard Worker }
37*d9f75844SAndroid Build Coastguard Worker 
38*d9f75844SAndroid Build Coastguard Worker }  // namespace rtc
39