1#include "cache.h"
2#include "run-command.h"
3#include "exec_cmd.h"
4static inline void close_pair(int fd[2])
6{
7 close(fd[0]);
8 close(fd[1]);
9}
10static inline void dup_devnull(int to)
12{
13 int fd = open("/dev/null", O_RDWR);
14 dup2(fd, to);
15 close(fd);
16}
17#ifndef WIN32
19static int child_err = 2;
20static int child_notifier = -1;
21static void notify_parent(void)
23{
24 write(child_notifier, "", 1);
25}
26static NORETURN void die_child(const char *err, va_list params)
28{
29 char msg[4096];
30 int len = vsnprintf(msg, sizeof(msg), err, params);
31 if (len > sizeof(msg))
32 len = sizeof(msg);
33 write(child_err, "fatal: ", 7);
35 write(child_err, msg, len);
36 write(child_err, "\n", 1);
37 exit(128);
38}
39static inline void set_cloexec(int fd)
41{
42 int flags = fcntl(fd, F_GETFD);
43 if (flags >= 0)
44 fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
45}
46#endif
47static int wait_or_whine(pid_t pid, const char *argv0, int silent_exec_failure)
49{
50 int status, code = -1;
51 pid_t waiting;
52 int failed_errno = 0;
53 while ((waiting = waitpid(pid, &status, 0)) < 0 && errno == EINTR)
55 ; /* nothing */
56 if (waiting < 0) {
58 failed_errno = errno;
59 error("waitpid for %s failed: %s", argv0, strerror(errno));
60 } else if (waiting != pid) {
61 error("waitpid is confused (%s)", argv0);
62 } else if (WIFSIGNALED(status)) {
63 code = WTERMSIG(status);
64 error("%s died of signal %d", argv0, code);
65 /*
66 * This return value is chosen so that code & 0xff
67 * mimics the exit code that a POSIX shell would report for
68 * a program that died from this signal.
69 */
70 code -= 128;
71 } else if (WIFEXITED(status)) {
72 code = WEXITSTATUS(status);
73 /*
74 * Convert special exit code when execvp failed.
75 */
76 if (code == 127) {
77 code = -1;
78 failed_errno = ENOENT;
79 if (!silent_exec_failure)
80 error("cannot run %s: %s", argv0,
81 strerror(ENOENT));
82 }
83 } else {
84 error("waitpid is confused (%s)", argv0);
85 }
86 errno = failed_errno;
87 return code;
88}
89int start_command(struct child_process *cmd)
91{
92 int need_in, need_out, need_err;
93 int fdin[2], fdout[2], fderr[2];
94 int failed_errno = failed_errno;
95 /*
97 * In case of errors we must keep the promise to close FDs
98 * that have been passed in via ->in and ->out.
99 */
100 need_in = !cmd->no_stdin && cmd->in < 0;
102 if (need_in) {
103 if (pipe(fdin) < 0) {
104 failed_errno = errno;
105 if (cmd->out > 0)
106 close(cmd->out);
107 goto fail_pipe;
108 }
109 cmd->in = fdin[1];
110 }
111 need_out = !cmd->no_stdout
113 && !cmd->stdout_to_stderr
114 && cmd->out < 0;
115 if (need_out) {
116 if (pipe(fdout) < 0) {
117 failed_errno = errno;
118 if (need_in)
119 close_pair(fdin);
120 else if (cmd->in)
121 close(cmd->in);
122 goto fail_pipe;
123 }
124 cmd->out = fdout[0];
125 }
126 need_err = !cmd->no_stderr && cmd->err < 0;
128 if (need_err) {
129 if (pipe(fderr) < 0) {
130 failed_errno = errno;
131 if (need_in)
132 close_pair(fdin);
133 else if (cmd->in)
134 close(cmd->in);
135 if (need_out)
136 close_pair(fdout);
137 else if (cmd->out)
138 close(cmd->out);
139fail_pipe:
140 error("cannot create pipe for %s: %s",
141 cmd->argv[0], strerror(failed_errno));
142 errno = failed_errno;
143 return -1;
144 }
145 cmd->err = fderr[0];
146 }
147 trace_argv_printf(cmd->argv, "trace: run_command:");
149#ifndef WIN32
151{
152 int notify_pipe[2];
153 if (pipe(notify_pipe))
154 notify_pipe[0] = notify_pipe[1] = -1;
155 fflush(NULL);
157 cmd->pid = fork();
158 if (!cmd->pid) {
159 /*
160 * Redirect the channel to write syscall error messages to
161 * before redirecting the process's stderr so that all die()
162 * in subsequent call paths use the parent's stderr.
163 */
164 if (cmd->no_stderr || need_err) {
165 child_err = dup(2);
166 set_cloexec(child_err);
167 }
168 set_die_routine(die_child);
169 close(notify_pipe[0]);
171 set_cloexec(notify_pipe[1]);
172 child_notifier = notify_pipe[1];
173 atexit(notify_parent);
174 if (cmd->no_stdin)
176 dup_devnull(0);
177 else if (need_in) {
178 dup2(fdin[0], 0);
179 close_pair(fdin);
180 } else if (cmd->in) {
181 dup2(cmd->in, 0);
182 close(cmd->in);
183 }
184 if (cmd->no_stderr)
186 dup_devnull(2);
187 else if (need_err) {
188 dup2(fderr[1], 2);
189 close_pair(fderr);
190 }
191 if (cmd->no_stdout)
193 dup_devnull(1);
194 else if (cmd->stdout_to_stderr)
195 dup2(2, 1);
196 else if (need_out) {
197 dup2(fdout[1], 1);
198 close_pair(fdout);
199 } else if (cmd->out > 1) {
200 dup2(cmd->out, 1);
201 close(cmd->out);
202 }
203 if (cmd->dir && chdir(cmd->dir))
205 die_errno("exec '%s': cd to '%s' failed", cmd->argv[0],
206 cmd->dir);
207 if (cmd->env) {
208 for (; *cmd->env; cmd->env++) {
209 if (strchr(*cmd->env, '='))
210 putenv((char *)*cmd->env);
211 else
212 unsetenv(*cmd->env);
213 }
214 }
215 if (cmd->preexec_cb) {
216 /*
217 * We cannot predict what the pre-exec callback does.
218 * Forgo parent notification.
219 */
220 close(child_notifier);
221 child_notifier = -1;
222 cmd->preexec_cb();
224 }
225 if (cmd->git_cmd) {
226 execv_git_cmd(cmd->argv);
227 } else {
228 execvp(cmd->argv[0], (char *const*) cmd->argv);
229 }
230 /*
231 * Do not check for cmd->silent_exec_failure; the parent
232 * process will check it when it sees this exit code.
233 */
234 if (errno == ENOENT)
235 exit(127);
236 else
237 die_errno("cannot exec '%s'", cmd->argv[0]);
238 }
239 if (cmd->pid < 0)
240 error("cannot fork() for %s: %s", cmd->argv[0],
241 strerror(failed_errno = errno));
242 /*
244 * Wait for child's execvp. If the execvp succeeds (or if fork()
245 * failed), EOF is seen immediately by the parent. Otherwise, the
246 * child process sends a single byte.
247 * Note that use of this infrastructure is completely advisory,
248 * therefore, we keep error checks minimal.
249 */
250 close(notify_pipe[1]);
251 if (read(notify_pipe[0], ¬ify_pipe[1], 1) == 1) {
252 /*
253 * At this point we know that fork() succeeded, but execvp()
254 * failed. Errors have been reported to our stderr.
255 */
256 wait_or_whine(cmd->pid, cmd->argv[0],
257 cmd->silent_exec_failure);
258 failed_errno = errno;
259 cmd->pid = -1;
260 }
261 close(notify_pipe[0]);
262}
263#else
264{
265 int s0 = -1, s1 = -1, s2 = -1; /* backups of stdin, stdout, stderr */
266 const char **sargv = cmd->argv;
267 char **env = environ;
268 if (cmd->no_stdin) {
270 s0 = dup(0);
271 dup_devnull(0);
272 } else if (need_in) {
273 s0 = dup(0);
274 dup2(fdin[0], 0);
275 } else if (cmd->in) {
276 s0 = dup(0);
277 dup2(cmd->in, 0);
278 }
279 if (cmd->no_stderr) {
281 s2 = dup(2);
282 dup_devnull(2);
283 } else if (need_err) {
284 s2 = dup(2);
285 dup2(fderr[1], 2);
286 }
287 if (cmd->no_stdout) {
289 s1 = dup(1);
290 dup_devnull(1);
291 } else if (cmd->stdout_to_stderr) {
292 s1 = dup(1);
293 dup2(2, 1);
294 } else if (need_out) {
295 s1 = dup(1);
296 dup2(fdout[1], 1);
297 } else if (cmd->out > 1) {
298 s1 = dup(1);
299 dup2(cmd->out, 1);
300 }
301 if (cmd->dir)
303 die("chdir in start_command() not implemented");
304 if (cmd->env)
305 env = make_augmented_environ(cmd->env);
306 if (cmd->git_cmd) {
308 cmd->argv = prepare_git_cmd(cmd->argv);
309 }
310 cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, env);
312 failed_errno = errno;
313 if (cmd->pid < 0 && (!cmd->silent_exec_failure || errno != ENOENT))
314 error("cannot spawn %s: %s", cmd->argv[0], strerror(errno));
315 if (cmd->env)
317 free_environ(env);
318 if (cmd->git_cmd)
319 free(cmd->argv);
320 cmd->argv = sargv;
322 if (s0 >= 0)
323 dup2(s0, 0), close(s0);
324 if (s1 >= 0)
325 dup2(s1, 1), close(s1);
326 if (s2 >= 0)
327 dup2(s2, 2), close(s2);
328}
329#endif
330 if (cmd->pid < 0) {
332 if (need_in)
333 close_pair(fdin);
334 else if (cmd->in)
335 close(cmd->in);
336 if (need_out)
337 close_pair(fdout);
338 else if (cmd->out)
339 close(cmd->out);
340 if (need_err)
341 close_pair(fderr);
342 errno = failed_errno;
343 return -1;
344 }
345 if (need_in)
347 close(fdin[0]);
348 else if (cmd->in)
349 close(cmd->in);
350 if (need_out)
352 close(fdout[1]);
353 else if (cmd->out)
354 close(cmd->out);
355 if (need_err)
357 close(fderr[1]);
358 return 0;
360}
361int finish_command(struct child_process *cmd)
363{
364 return wait_or_whine(cmd->pid, cmd->argv[0], cmd->silent_exec_failure);
365}
366int run_command(struct child_process *cmd)
368{
369 int code = start_command(cmd);
370 if (code)
371 return code;
372 return finish_command(cmd);
373}
374static void prepare_run_command_v_opt(struct child_process *cmd,
376 const char **argv,
377 int opt)
378{
379 memset(cmd, 0, sizeof(*cmd));
380 cmd->argv = argv;
381 cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
382 cmd->git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
383 cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
384 cmd->silent_exec_failure = opt & RUN_SILENT_EXEC_FAILURE ? 1 : 0;
385}
386int run_command_v_opt(const char **argv, int opt)
388{
389 struct child_process cmd;
390 prepare_run_command_v_opt(&cmd, argv, opt);
391 return run_command(&cmd);
392}
393int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
395{
396 struct child_process cmd;
397 prepare_run_command_v_opt(&cmd, argv, opt);
398 cmd.dir = dir;
399 cmd.env = env;
400 return run_command(&cmd);
401}
402#ifdef WIN32
404static unsigned __stdcall run_thread(void *data)
405{
406 struct async *async = data;
407 return async->proc(async->fd_for_proc, async->data);
408}
409#endif
410int start_async(struct async *async)
412{
413 int pipe_out[2];
414 if (pipe(pipe_out) < 0)
416 return error("cannot create pipe: %s", strerror(errno));
417 async->out = pipe_out[0];
418#ifndef WIN32
420 /* Flush stdio before fork() to avoid cloning buffers */
421 fflush(NULL);
422 async->pid = fork();
424 if (async->pid < 0) {
425 error("fork (async) failed: %s", strerror(errno));
426 close_pair(pipe_out);
427 return -1;
428 }
429 if (!async->pid) {
430 close(pipe_out[0]);
431 exit(!!async->proc(pipe_out[1], async->data));
432 }
433 close(pipe_out[1]);
434#else
435 async->fd_for_proc = pipe_out[1];
436 async->tid = (HANDLE) _beginthreadex(NULL, 0, run_thread, async, 0, NULL);
437 if (!async->tid) {
438 error("cannot create thread: %s", strerror(errno));
439 close_pair(pipe_out);
440 return -1;
441 }
442#endif
443 return 0;
444}
445int finish_async(struct async *async)
447{
448#ifndef WIN32
449 int ret = wait_or_whine(async->pid, "child process", 0);
450#else
451 DWORD ret = 0;
452 if (WaitForSingleObject(async->tid, INFINITE) != WAIT_OBJECT_0)
453 ret = error("waiting for thread failed: %lu", GetLastError());
454 else if (!GetExitCodeThread(async->tid, &ret))
455 ret = error("cannot get thread exit code: %lu", GetLastError());
456 CloseHandle(async->tid);
457#endif
458 return ret;
459}
460int run_hook(const char *index_file, const char *name, ...)
462{
463 struct child_process hook;
464 const char **argv = NULL, *env[2];
465 char index[PATH_MAX];
466 va_list args;
467 int ret;
468 size_t i = 0, alloc = 0;
469 if (access(git_path("hooks/%s", name), X_OK) < 0)
471 return 0;
472 va_start(args, name);
474 ALLOC_GROW(argv, i + 1, alloc);
475 argv[i++] = git_path("hooks/%s", name);
476 while (argv[i-1]) {
477 ALLOC_GROW(argv, i + 1, alloc);
478 argv[i++] = va_arg(args, const char *);
479 }
480 va_end(args);
481 memset(&hook, 0, sizeof(hook));
483 hook.argv = argv;
484 hook.no_stdin = 1;
485 hook.stdout_to_stderr = 1;
486 if (index_file) {
487 snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", index_file);
488 env[0] = index;
489 env[1] = NULL;
490 hook.env = env;
491 }
492 ret = run_command(&hook);
494 free(argv);
495 return ret;
496}