77 lines
2.1 KiB
C++
77 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 "atom/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/posix/eintr_wrapper.h"
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#include "base/process/launch.h"
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namespace relauncher {
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namespace internal {
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void RelauncherSynchronizeWithParent() {
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base::ScopedFD relauncher_sync_fd(kRelauncherSyncFD);
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// Don't execute signal handlers of SIGUSR2.
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sigset_t mask;
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sigemptyset(&mask);
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sigaddset(&mask, SIGUSR2);
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if (sigprocmask(SIG_BLOCK, &mask, NULL) < 0) {
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PLOG(ERROR) << "sigprocmask";
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return;
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}
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// Create a signalfd that watches for SIGUSR2.
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int usr2_fd = signalfd(-1, &mask, 0);
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if (usr2_fd < 0) {
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PLOG(ERROR) << "signalfd";
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return;
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}
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// Send SIGUSR2 to current process when parent process ends.
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if (HANDLE_EINTR(prctl(PR_SET_PDEATHSIG, SIGUSR2)) != 0) {
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PLOG(ERROR) << "prctl";
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return;
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}
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// Write a '\0' character to the pipe.
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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 the SIGUSR2 signal to happen.
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struct signalfd_siginfo si;
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HANDLE_EINTR(read(usr2_fd, &si, sizeof(si)));
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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::FileHandleMappingVector no_stdout;
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no_stdout.push_back(std::make_pair(devnull.get(), STDERR_FILENO));
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no_stdout.push_back(std::make_pair(devnull.get(), STDOUT_FILENO));
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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 = &no_stdout;
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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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