Line data Source code
1 : // Copyright 2017 the V8 project authors. All rights reserved.
2 : // Use of this source code is governed by a BSD-style license that can be
3 : // found in the LICENSE file.
4 :
5 : // PLEASE READ BEFORE CHANGING THIS FILE!
6 : //
7 : // This file contains code that is used both inside and outside the out of
8 : // bounds signal handler. Because this code runs in a signal handler context,
9 : // use extra care when modifying this file. Here are some rules to follow.
10 : //
11 : // 1. Do not introduce any new external dependencies. This file needs
12 : // to be self contained so it is easy to audit everything that a
13 : // signal handler might do.
14 : //
15 : // 2. Any changes must be reviewed by someone from the crash reporting
16 : // or security team. See OWNERS for suggested reviewers.
17 : //
18 : // For more information, see https://goo.gl/yMeyUY.
19 :
20 : #include "src/trap-handler/trap-handler-internal.h"
21 :
22 : namespace v8 {
23 : namespace internal {
24 : namespace trap_handler {
25 :
26 : THREAD_LOCAL bool g_thread_in_wasm_code = false;
27 :
28 : size_t gNumCodeObjects = 0;
29 : CodeProtectionInfoListEntry* gCodeObjects = nullptr;
30 :
31 : std::atomic_flag MetadataLock::spinlock_ = ATOMIC_FLAG_INIT;
32 :
33 2756 : MetadataLock::MetadataLock() {
34 2756 : if (g_thread_in_wasm_code) {
35 0 : abort();
36 : }
37 :
38 2756 : while (spinlock_.test_and_set(std::memory_order::memory_order_acquire)) {
39 : }
40 2756 : }
41 :
42 2756 : MetadataLock::~MetadataLock() {
43 2756 : if (g_thread_in_wasm_code) {
44 0 : abort();
45 : }
46 :
47 : spinlock_.clear(std::memory_order::memory_order_release);
48 2756 : }
49 :
50 : } // namespace trap_handler
51 : } // namespace internal
52 : } // namespace v8
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