1 // Copyright (c) 2012 The Chromium 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.
5 #include "sandbox/linux/seccomp-bpf/die.h"
10 #include <sys/prctl.h>
11 #include <sys/syscall.h>
16 #include "base/logging.h"
17 #include "base/posix/eintr_wrapper.h"
18 #include "sandbox/linux/seccomp-bpf/syscall.h"
22 void Die::ExitGroup() {
23 // exit_group() should exit our program. After all, it is defined as a
24 // function that doesn't return. But things can theoretically go wrong.
25 // Especially, since we are dealing with system call filters. Continuing
26 // execution would be very bad in most cases where ExitGroup() gets called.
27 // So, we'll try a few other strategies too.
28 Syscall::Call(__NR_exit_group, 1);
30 // We have no idea what our run-time environment looks like. So, signal
31 // handlers might or might not do the right thing. Try to reset settings
32 // to a defined state; but we have not way to verify whether we actually
33 // succeeded in doing so. Nonetheless, triggering a fatal signal could help
35 signal(SIGSEGV, SIG_DFL);
36 Syscall::Call(__NR_prctl, PR_SET_DUMPABLE, (void*)0, (void*)0, (void*)0);
37 if (*(volatile char*)0) {
40 // If there is no way for us to ask for the program to exit, the next
41 // best thing we can do is to loop indefinitely. Maybe, somebody will notice
43 // We in fact retry the system call inside of our loop so that it will
44 // stand out when somebody tries to diagnose the problem by using "strace".
46 Syscall::Call(__NR_exit_group, 1);
50 void Die::SandboxDie(const char* msg, const char* file, int line) {
52 LogToStderr(msg, file, line);
54 logging::LogMessage(file, line, logging::LOG_FATAL).stream() << msg;
59 void Die::RawSandboxDie(const char* msg) {
66 void Die::SandboxInfo(const char* msg, const char* file, int line) {
67 if (!suppress_info_) {
68 logging::LogMessage(file, line, logging::LOG_INFO).stream() << msg;
72 void Die::LogToStderr(const char* msg, const char* file, int line) {
75 snprintf(buf, sizeof(buf), "%d", line);
76 std::string s = std::string(file) + ":" + buf + ":" + msg + "\n";
78 // No need to loop. Short write()s are unlikely and if they happen we
79 // probably prefer them over a loop that blocks.
81 HANDLE_EINTR(Syscall::Call(__NR_write, 2, s.c_str(), s.length())));
85 bool Die::simple_exit_ = false;
86 bool Die::suppress_info_ = false;
88 } // namespace sandbox