mirror of https://github.com/electron/electron
70 lines
2.1 KiB
C++
70 lines
2.1 KiB
C++
// Copyright (c) 2016 GitHub, Inc.
|
|
// Use of this source code is governed by the MIT license that can be
|
|
// found in the LICENSE file.
|
|
|
|
#include "shell/browser/relauncher.h"
|
|
|
|
#include <fcntl.h>
|
|
#include <signal.h>
|
|
#include <sys/prctl.h>
|
|
#include <sys/signalfd.h>
|
|
|
|
#include "base/files/file_util.h"
|
|
#include "base/files/scoped_file.h"
|
|
#include "base/logging.h"
|
|
#include "base/process/launch.h"
|
|
#include "base/synchronization/waitable_event.h"
|
|
|
|
namespace relauncher::internal {
|
|
|
|
// this is global to be visible to the sa_handler
|
|
base::WaitableEvent parentWaiter;
|
|
|
|
void RelauncherSynchronizeWithParent() {
|
|
base::ScopedFD relauncher_sync_fd(kRelauncherSyncFD);
|
|
static const auto signum = SIGUSR2;
|
|
|
|
// send signum to current process when parent process ends.
|
|
if (HANDLE_EINTR(prctl(PR_SET_PDEATHSIG, signum)) != 0) {
|
|
PLOG(ERROR) << "prctl";
|
|
return;
|
|
}
|
|
|
|
// set up a signum handler
|
|
struct sigaction action;
|
|
memset(&action, 0, sizeof(action));
|
|
action.sa_handler = [](int /*signum*/) { parentWaiter.Signal(); };
|
|
if (sigaction(signum, &action, nullptr) != 0) {
|
|
PLOG(ERROR) << "sigaction";
|
|
return;
|
|
}
|
|
|
|
// write a '\0' character to the pipe to the parent process.
|
|
// this is how the parent knows that we're ready for it to exit.
|
|
if (HANDLE_EINTR(write(relauncher_sync_fd.get(), "", 1)) != 1) {
|
|
PLOG(ERROR) << "write";
|
|
return;
|
|
}
|
|
|
|
// Wait for the parent to exit
|
|
parentWaiter.Wait();
|
|
}
|
|
|
|
int LaunchProgram(const StringVector& relauncher_args,
|
|
const StringVector& argv) {
|
|
// Redirect the stdout of child process to /dev/null, otherwise after
|
|
// relaunch the child process will raise exception when writing to stdout.
|
|
base::ScopedFD devnull(HANDLE_EINTR(open("/dev/null", O_WRONLY)));
|
|
|
|
base::LaunchOptions options;
|
|
options.allow_new_privs = true;
|
|
options.new_process_group = true; // detach
|
|
options.fds_to_remap.emplace_back(devnull.get(), STDERR_FILENO);
|
|
options.fds_to_remap.emplace_back(devnull.get(), STDOUT_FILENO);
|
|
|
|
base::Process process = base::LaunchProcess(argv, options);
|
|
return process.IsValid() ? 0 : 1;
|
|
}
|
|
|
|
} // namespace relauncher::internal
|