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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
// Copyright (c) 2008 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "base/process_util.h"
#include <fcntl.h>
#include <os/availability.h>
#include <spawn.h>
#include <sys/wait.h>
#include <unistd.h>
#include <string>
#include "base/command_line.h"
#include "base/eintr_wrapper.h"
#include "base/logging.h"
#include "mozilla/ipc/FileDescriptorShuffle.h"
#include "mozilla/ScopeExit.h"
#include "mozilla/Result.h"
#include "mozilla/ipc/LaunchError.h"
extern "C" {
// N.B. the syscalls are available back to 10.5, but the C wrappers
// only in 10.12. Fortunately, 10.15 is our current baseline.
int pthread_fchdir_np(int fd) API_AVAILABLE(macosx(10.12));
int responsibility_spawnattrs_setdisclaim(posix_spawnattr_t attrs, int disclaim)
API_AVAILABLE(macosx(10.14));
}
namespace {
static mozilla::EnvironmentLog gProcessLog("MOZ_PROCESS_LOG");
} // namespace
namespace base {
Result<Ok, LaunchError> LaunchApp(const std::vector<std::string>& argv,
LaunchOptions&& options,
ProcessHandle* process_handle) {
Result<Ok, LaunchError> retval = Ok();
char* argv_copy[argv.size() + 1];
for (size_t i = 0; i < argv.size(); i++) {
argv_copy[i] = const_cast<char*>(argv[i].c_str());
}
argv_copy[argv.size()] = NULL;
EnvironmentArray env_storage;
const EnvironmentArray& vars =
options.full_env ? options.full_env
: (env_storage = BuildEnvironmentArray(options.env_map));
posix_spawn_file_actions_t file_actions;
int err = posix_spawn_file_actions_init(&file_actions);
if (err != 0) {
DLOG(WARNING) << "posix_spawn_file_actions_init failed";
return Err(LaunchError("posix_spawn_file_actions_init", err));
}
auto file_actions_guard = mozilla::MakeScopeExit(
[&file_actions] { posix_spawn_file_actions_destroy(&file_actions); });
// Turn fds_to_remap array into a set of dup2 calls.
//
// Init() there will call fcntl(F_DUPFD/F_DUPFD_CLOEXEC) under the hood in
// so it will set errno.
mozilla::ipc::FileDescriptorShuffle shuffle;
if (!shuffle.Init(options.fds_to_remap)) {
DLOG(WARNING) << "FileDescriptorShuffle::Init failed";
return Err(LaunchError("FileDescriptorShuffle", errno));
}
for (const auto& fd_map : shuffle.Dup2Sequence()) {
int src_fd = fd_map.first;
int dest_fd = fd_map.second;
int rv = posix_spawn_file_actions_adddup2(&file_actions, src_fd, dest_fd);
if (rv != 0) {
DLOG(WARNING) << "posix_spawn_file_actions_adddup2 failed";
return Err(LaunchError("posix_spawn_file_actions_adddup2", rv));
}
}
if (!options.workdir.empty()) {
int rv = posix_spawn_file_actions_addchdir_np(&file_actions,
options.workdir.c_str());
if (rv != 0) {
DLOG(WARNING) << "posix_spawn_file_actions_addchdir_np failed";
return Err(LaunchError("posix_spawn_file_actions_addchdir", rv));
}
}
// Initialize spawn attributes.
posix_spawnattr_t spawnattr;
err = posix_spawnattr_init(&spawnattr);
if (err != 0) {
DLOG(WARNING) << "posix_spawnattr_init failed";
return Err(LaunchError("posix_spawnattr_init", err));
}
auto spawnattr_guard = mozilla::MakeScopeExit(
[&spawnattr] { posix_spawnattr_destroy(&spawnattr); });
#if defined(XP_MACOSX) && defined(__aarch64__)
if (options.arch == PROCESS_ARCH_X86_64) {
cpu_type_t cpu_pref = CPU_TYPE_X86_64;
size_t count = 1;
size_t ocount = 0;
int rv =
posix_spawnattr_setbinpref_np(&spawnattr, count, &cpu_pref, &ocount);
if ((rv != 0) || (ocount != count)) {
DLOG(WARNING) << "posix_spawnattr_setbinpref_np failed";
return Err(LaunchError("posix_spawnattr_setbinpref_np", rv));
}
}
#endif
if (options.disclaim) {
int err = responsibility_spawnattrs_setdisclaim(&spawnattr, 1);
if (err != 0) {
DLOG(WARNING) << "responsibility_spawnattrs_setdisclaim failed";
return Err(LaunchError("responsibility_spawnattrs_setdisclaim", err));
}
}
// Prevent the child process from inheriting any file descriptors
// that aren't named in `file_actions`. (This is an Apple-specific
// extension to posix_spawn.)
err = posix_spawnattr_setflags(&spawnattr, POSIX_SPAWN_CLOEXEC_DEFAULT);
if (err != 0) {
DLOG(WARNING) << "posix_spawnattr_setflags failed";
return Err(LaunchError("posix_spawnattr_setflags", err));
}
// Exempt std{in,out,err} from being closed by POSIX_SPAWN_CLOEXEC_DEFAULT.
for (int fd = 0; fd <= STDERR_FILENO; ++fd) {
err = posix_spawn_file_actions_addinherit_np(&file_actions, fd);
if (err != 0) {
DLOG(WARNING) << "posix_spawn_file_actions_addinherit_np failed";
return Err(LaunchError("posix_spawn_file_actions_addinherit_np", err));
}
}
int pid = 0;
int spawn_succeeded = (posix_spawnp(&pid, argv_copy[0], &file_actions,
&spawnattr, argv_copy, vars.get()) == 0);
bool process_handle_valid = pid > 0;
if (!spawn_succeeded || !process_handle_valid) {
DLOG(WARNING) << "posix_spawnp failed";
retval = Err(LaunchError("posix_spawnp", spawn_succeeded));
} else {
gProcessLog.print("==> process %d launched child process %d\n",
GetCurrentProcId(), pid);
if (options.wait) HANDLE_EINTR(waitpid(pid, 0, 0));
if (process_handle) *process_handle = pid;
}
return retval;
}
} // namespace base