b2652beceb
* refactor: fix clang-tidy vector operation warnings Fix vector population performance-inefficient-vector-operation warnings generated by clang-tidy * refactor: fix clang-tidy emplace_back warnings In cases where a temporary is created to be passed to push_back(), replace it with emplace_back(). Warning: modernize-use-emplace * refactor: fix clang-tidy loop iteration warnings When practical, use range-based for loops instead of C-style for loops. clang-tiny check: modernize-loop-convert * refactor: fix clang-tidy string initialize warning Remove redundant empty string initialization. clang-tidy check: readability-redundant-string-init
73 lines
2.1 KiB
C++
73 lines
2.1 KiB
C++
// Copyright (c) 2016 GitHub, Inc.
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// Use of this source code is governed by the MIT license that can be
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// found in the LICENSE file.
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#include "shell/browser/relauncher.h"
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#include <fcntl.h>
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#include <signal.h>
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#include <sys/prctl.h>
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#include <sys/signalfd.h>
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#include "base/files/file_util.h"
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#include "base/files/scoped_file.h"
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#include "base/logging.h"
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#include "base/process/launch.h"
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#include "base/synchronization/waitable_event.h"
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namespace relauncher {
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namespace internal {
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// this is global to be visible to the sa_handler
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base::WaitableEvent parentWaiter;
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void RelauncherSynchronizeWithParent() {
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base::ScopedFD relauncher_sync_fd(kRelauncherSyncFD);
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static const auto signum = SIGUSR2;
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// send signum to current process when parent process ends.
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if (HANDLE_EINTR(prctl(PR_SET_PDEATHSIG, signum)) != 0) {
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PLOG(ERROR) << "prctl";
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return;
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}
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// set up a signum handler
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struct sigaction action;
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memset(&action, 0, sizeof(action));
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action.sa_handler = [](int /*signum*/) { parentWaiter.Signal(); };
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if (sigaction(signum, &action, nullptr) != 0) {
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PLOG(ERROR) << "sigaction";
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return;
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}
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// write a '\0' character to the pipe to the parent process.
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// this is how the parent knows that we're ready for it to exit.
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if (HANDLE_EINTR(write(relauncher_sync_fd.get(), "", 1)) != 1) {
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PLOG(ERROR) << "write";
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return;
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}
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// Wait for the parent to exit
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parentWaiter.Wait();
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}
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int LaunchProgram(const StringVector& relauncher_args,
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const StringVector& argv) {
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// Redirect the stdout of child process to /dev/null, otherwise after
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// relaunch the child process will raise exception when writing to stdout.
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base::ScopedFD devnull(HANDLE_EINTR(open("/dev/null", O_WRONLY)));
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base::LaunchOptions options;
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options.allow_new_privs = true;
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options.new_process_group = true; // detach
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options.fds_to_remap.emplace_back(devnull.get(), STDERR_FILENO);
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options.fds_to_remap.emplace_back(devnull.get(), STDOUT_FILENO);
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base::Process process = base::LaunchProcess(argv, options);
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return process.IsValid() ? 0 : 1;
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}
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} // namespace internal
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} // namespace relauncher
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