Daniel Erat | b8cf949 | 2015-07-06 13:18:13 -0600 | [diff] [blame] | 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. |
| 4 | |
| 5 | #include "base/process/launch.h" |
| 6 | |
Jay Civelli | 3a83cdd | 2017-03-22 17:31:44 -0700 | [diff] [blame^] | 7 | #include <crt_externs.h> |
Daniel Erat | b8cf949 | 2015-07-06 13:18:13 -0600 | [diff] [blame] | 8 | #include <mach/mach.h> |
Jay Civelli | 3a83cdd | 2017-03-22 17:31:44 -0700 | [diff] [blame^] | 9 | #include <spawn.h> |
| 10 | #include <string.h> |
| 11 | #include <sys/wait.h> |
Daniel Erat | b8cf949 | 2015-07-06 13:18:13 -0600 | [diff] [blame] | 12 | |
| 13 | #include "base/logging.h" |
Jay Civelli | 3a83cdd | 2017-03-22 17:31:44 -0700 | [diff] [blame^] | 14 | #include "base/posix/eintr_wrapper.h" |
| 15 | #include "base/threading/thread_restrictions.h" |
Daniel Erat | b8cf949 | 2015-07-06 13:18:13 -0600 | [diff] [blame] | 16 | |
| 17 | namespace base { |
| 18 | |
Jay Civelli | 3a83cdd | 2017-03-22 17:31:44 -0700 | [diff] [blame^] | 19 | namespace { |
| 20 | |
| 21 | // DPSXCHECK is a Debug Posix Spawn Check macro. The posix_spawn* family of |
| 22 | // functions return an errno value, as opposed to setting errno directly. This |
| 23 | // macro emulates a DPCHECK(). |
| 24 | #define DPSXCHECK(expr) \ |
| 25 | do { \ |
| 26 | int rv = (expr); \ |
| 27 | DCHECK_EQ(rv, 0) << #expr << ": -" << rv << " " << strerror(rv); \ |
| 28 | } while (0) |
| 29 | |
| 30 | class PosixSpawnAttr { |
| 31 | public: |
| 32 | PosixSpawnAttr() { DPSXCHECK(posix_spawnattr_init(&attr_)); } |
| 33 | |
| 34 | ~PosixSpawnAttr() { DPSXCHECK(posix_spawnattr_destroy(&attr_)); } |
| 35 | |
| 36 | posix_spawnattr_t* get() { return &attr_; } |
| 37 | |
| 38 | private: |
| 39 | posix_spawnattr_t attr_; |
| 40 | }; |
| 41 | |
| 42 | class PosixSpawnFileActions { |
| 43 | public: |
| 44 | PosixSpawnFileActions() { |
| 45 | DPSXCHECK(posix_spawn_file_actions_init(&file_actions_)); |
| 46 | } |
| 47 | |
| 48 | ~PosixSpawnFileActions() { |
| 49 | DPSXCHECK(posix_spawn_file_actions_destroy(&file_actions_)); |
| 50 | } |
| 51 | |
| 52 | void Open(int filedes, const char* path, int mode) { |
| 53 | DPSXCHECK(posix_spawn_file_actions_addopen(&file_actions_, filedes, path, |
| 54 | mode, 0)); |
| 55 | } |
| 56 | |
| 57 | void Dup2(int filedes, int newfiledes) { |
| 58 | DPSXCHECK( |
| 59 | posix_spawn_file_actions_adddup2(&file_actions_, filedes, newfiledes)); |
| 60 | } |
| 61 | |
| 62 | void Inherit(int filedes) { |
| 63 | DPSXCHECK(posix_spawn_file_actions_addinherit_np(&file_actions_, filedes)); |
| 64 | } |
| 65 | |
| 66 | const posix_spawn_file_actions_t* get() const { return &file_actions_; } |
| 67 | |
| 68 | private: |
| 69 | posix_spawn_file_actions_t file_actions_; |
| 70 | |
| 71 | DISALLOW_COPY_AND_ASSIGN(PosixSpawnFileActions); |
| 72 | }; |
| 73 | |
| 74 | } // namespace |
| 75 | |
Daniel Erat | b8cf949 | 2015-07-06 13:18:13 -0600 | [diff] [blame] | 76 | void RestoreDefaultExceptionHandler() { |
| 77 | // This function is tailored to remove the Breakpad exception handler. |
| 78 | // exception_mask matches s_exception_mask in |
| 79 | // breakpad/src/client/mac/handler/exception_handler.cc |
| 80 | const exception_mask_t exception_mask = EXC_MASK_BAD_ACCESS | |
| 81 | EXC_MASK_BAD_INSTRUCTION | |
| 82 | EXC_MASK_ARITHMETIC | |
| 83 | EXC_MASK_BREAKPOINT; |
| 84 | |
| 85 | // Setting the exception port to MACH_PORT_NULL may not be entirely |
| 86 | // kosher to restore the default exception handler, but in practice, |
| 87 | // it results in the exception port being set to Apple Crash Reporter, |
| 88 | // the desired behavior. |
| 89 | task_set_exception_ports(mach_task_self(), exception_mask, MACH_PORT_NULL, |
| 90 | EXCEPTION_DEFAULT, THREAD_STATE_NONE); |
| 91 | } |
| 92 | |
Jay Civelli | 3a83cdd | 2017-03-22 17:31:44 -0700 | [diff] [blame^] | 93 | Process LaunchProcessPosixSpawn(const std::vector<std::string>& argv, |
| 94 | const LaunchOptions& options) { |
| 95 | DCHECK(!options.pre_exec_delegate) |
| 96 | << "LaunchProcessPosixSpawn does not support PreExecDelegate"; |
| 97 | DCHECK(options.current_directory.empty()) |
| 98 | << "LaunchProcessPosixSpawn does not support current_directory"; |
| 99 | |
| 100 | PosixSpawnAttr attr; |
| 101 | |
| 102 | short flags = POSIX_SPAWN_CLOEXEC_DEFAULT; |
| 103 | if (options.new_process_group) { |
| 104 | flags |= POSIX_SPAWN_SETPGROUP; |
| 105 | DPSXCHECK(posix_spawnattr_setpgroup(attr.get(), 0)); |
| 106 | } |
| 107 | DPSXCHECK(posix_spawnattr_setflags(attr.get(), flags)); |
| 108 | |
| 109 | PosixSpawnFileActions file_actions; |
| 110 | |
| 111 | // Process file descriptors for the child. By default, LaunchProcess will |
| 112 | // open stdin to /dev/null and inherit stdout and stderr. |
| 113 | bool inherit_stdout = true, inherit_stderr = true; |
| 114 | bool null_stdin = true; |
| 115 | if (options.fds_to_remap) { |
| 116 | for (const auto& dup2_pair : *options.fds_to_remap) { |
| 117 | if (dup2_pair.second == STDIN_FILENO) { |
| 118 | null_stdin = false; |
| 119 | } else if (dup2_pair.second == STDOUT_FILENO) { |
| 120 | inherit_stdout = false; |
| 121 | } else if (dup2_pair.second == STDERR_FILENO) { |
| 122 | inherit_stderr = false; |
| 123 | } |
| 124 | |
| 125 | if (dup2_pair.first == dup2_pair.second) { |
| 126 | file_actions.Inherit(dup2_pair.second); |
| 127 | } else { |
| 128 | file_actions.Dup2(dup2_pair.first, dup2_pair.second); |
| 129 | } |
| 130 | } |
| 131 | } |
| 132 | |
| 133 | if (null_stdin) { |
| 134 | file_actions.Open(STDIN_FILENO, "/dev/null", O_RDONLY); |
| 135 | } |
| 136 | if (inherit_stdout) { |
| 137 | file_actions.Inherit(STDOUT_FILENO); |
| 138 | } |
| 139 | if (inherit_stderr) { |
| 140 | file_actions.Inherit(STDERR_FILENO); |
| 141 | } |
| 142 | |
| 143 | std::unique_ptr<char* []> argv_cstr(new char*[argv.size() + 1]); |
| 144 | for (size_t i = 0; i < argv.size(); i++) { |
| 145 | argv_cstr[i] = const_cast<char*>(argv[i].c_str()); |
| 146 | } |
| 147 | argv_cstr[argv.size()] = nullptr; |
| 148 | |
| 149 | std::unique_ptr<char* []> owned_environ; |
| 150 | char** new_environ = options.clear_environ ? nullptr : *_NSGetEnviron(); |
| 151 | if (!options.environ.empty()) { |
| 152 | owned_environ = AlterEnvironment(new_environ, options.environ); |
| 153 | new_environ = owned_environ.get(); |
| 154 | } |
| 155 | |
| 156 | const char* executable_path = !options.real_path.empty() |
| 157 | ? options.real_path.value().c_str() |
| 158 | : argv_cstr[0]; |
| 159 | |
| 160 | // Use posix_spawnp as some callers expect to have PATH consulted. |
| 161 | pid_t pid; |
| 162 | int rv = posix_spawnp(&pid, executable_path, file_actions.get(), attr.get(), |
| 163 | &argv_cstr[0], new_environ); |
| 164 | |
| 165 | if (rv != 0) { |
| 166 | DLOG(ERROR) << "posix_spawnp(" << executable_path << "): -" << rv << " " |
| 167 | << strerror(rv); |
| 168 | return Process(); |
| 169 | } |
| 170 | |
| 171 | if (options.wait) { |
| 172 | // While this isn't strictly disk IO, waiting for another process to |
| 173 | // finish is the sort of thing ThreadRestrictions is trying to prevent. |
| 174 | base::ThreadRestrictions::AssertIOAllowed(); |
| 175 | pid_t ret = HANDLE_EINTR(waitpid(pid, nullptr, 0)); |
| 176 | DPCHECK(ret > 0); |
| 177 | } |
| 178 | |
| 179 | return Process(pid); |
| 180 | } |
| 181 | |
Daniel Erat | b8cf949 | 2015-07-06 13:18:13 -0600 | [diff] [blame] | 182 | } // namespace base |