1#include "cache.h"
2#include "run-command.h"
3#include "exec_cmd.h"
4#include "sigchain.h"
5#include "argv-array.h"
6struct child_to_clean {
8 pid_t pid;
9 struct child_to_clean *next;
10};
11static struct child_to_clean *children_to_clean;
12static int installed_child_cleanup_handler;
13static void cleanup_children(int sig)
15{
16 while (children_to_clean) {
17 struct child_to_clean *p = children_to_clean;
18 children_to_clean = p->next;
19 kill(p->pid, sig);
20 free(p);
21 }
22}
23static void cleanup_children_on_signal(int sig)
25{
26 cleanup_children(sig);
27 sigchain_pop(sig);
28 raise(sig);
29}
30static void cleanup_children_on_exit(void)
32{
33 cleanup_children(SIGTERM);
34}
35static void mark_child_for_cleanup(pid_t pid)
37{
38 struct child_to_clean *p = xmalloc(sizeof(*p));
39 p->pid = pid;
40 p->next = children_to_clean;
41 children_to_clean = p;
42 if (!installed_child_cleanup_handler) {
44 atexit(cleanup_children_on_exit);
45 sigchain_push_common(cleanup_children_on_signal);
46 installed_child_cleanup_handler = 1;
47 }
48}
49static void clear_child_for_cleanup(pid_t pid)
51{
52 struct child_to_clean **last, *p;
53 last = &children_to_clean;
55 for (p = children_to_clean; p; p = p->next) {
56 if (p->pid == pid) {
57 *last = p->next;
58 free(p);
59 return;
60 }
61 }
62}
63static inline void close_pair(int fd[2])
65{
66 close(fd[0]);
67 close(fd[1]);
68}
69#ifndef WIN32
71static inline void dup_devnull(int to)
72{
73 int fd = open("/dev/null", O_RDWR);
74 dup2(fd, to);
75 close(fd);
76}
77#endif
78static const char **prepare_shell_cmd(const char **argv)
80{
81 int argc, nargc = 0;
82 const char **nargv;
83 for (argc = 0; argv[argc]; argc++)
85 ; /* just counting */
86 /* +1 for NULL, +3 for "sh -c" plus extra $0 */
87 nargv = xmalloc(sizeof(*nargv) * (argc + 1 + 3));
88 if (argc < 1)
90 die("BUG: shell command is empty");
91 if (strcspn(argv[0], "|&;<>()$`\\\"' \t\n*?[#~=%") != strlen(argv[0])) {
93 nargv[nargc++] = "sh";
94 nargv[nargc++] = "-c";
95 if (argc < 2)
97 nargv[nargc++] = argv[0];
98 else {
99 struct strbuf arg0 = STRBUF_INIT;
100 strbuf_addf(&arg0, "%s \"$@\"", argv[0]);
101 nargv[nargc++] = strbuf_detach(&arg0, NULL);
102 }
103 }
104 for (argc = 0; argv[argc]; argc++)
106 nargv[nargc++] = argv[argc];
107 nargv[nargc] = NULL;
108 return nargv;
110}
111#ifndef WIN32
113static int execv_shell_cmd(const char **argv)
114{
115 const char **nargv = prepare_shell_cmd(argv);
116 trace_argv_printf(nargv, "trace: exec:");
117 execvp(nargv[0], (char **)nargv);
118 free(nargv);
119 return -1;
120}
121#endif
122#ifndef WIN32
124static int child_err = 2;
125static int child_notifier = -1;
126static void notify_parent(void)
128{
129 /*
130 * execvp failed. If possible, we'd like to let start_command
131 * know, so failures like ENOENT can be handled right away; but
132 * otherwise, finish_command will still report the error.
133 */
134 xwrite(child_notifier, "", 1);
135}
136static NORETURN void die_child(const char *err, va_list params)
138{
139 vwritef(child_err, "fatal: ", err, params);
140 exit(128);
141}
142static void error_child(const char *err, va_list params)
144{
145 vwritef(child_err, "error: ", err, params);
146}
147#endif
148static inline void set_cloexec(int fd)
150{
151 int flags = fcntl(fd, F_GETFD);
152 if (flags >= 0)
153 fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
154}
155static int wait_or_whine(pid_t pid, const char *argv0, int silent_exec_failure)
157{
158 int status, code = -1;
159 pid_t waiting;
160 int failed_errno = 0;
161 while ((waiting = waitpid(pid, &status, 0)) < 0 && errno == EINTR)
163 ; /* nothing */
164 if (waiting < 0) {
166 failed_errno = errno;
167 error("waitpid for %s failed: %s", argv0, strerror(errno));
168 } else if (waiting != pid) {
169 error("waitpid is confused (%s)", argv0);
170 } else if (WIFSIGNALED(status)) {
171 code = WTERMSIG(status);
172 error("%s died of signal %d", argv0, code);
173 /*
174 * This return value is chosen so that code & 0xff
175 * mimics the exit code that a POSIX shell would report for
176 * a program that died from this signal.
177 */
178 code -= 128;
179 } else if (WIFEXITED(status)) {
180 code = WEXITSTATUS(status);
181 /*
182 * Convert special exit code when execvp failed.
183 */
184 if (code == 127) {
185 code = -1;
186 failed_errno = ENOENT;
187 }
188 } else {
189 error("waitpid is confused (%s)", argv0);
190 }
191 clear_child_for_cleanup(pid);
193 errno = failed_errno;
195 return code;
196}
197int start_command(struct child_process *cmd)
199{
200 int need_in, need_out, need_err;
201 int fdin[2], fdout[2], fderr[2];
202 int failed_errno = failed_errno;
203 /*
205 * In case of errors we must keep the promise to close FDs
206 * that have been passed in via ->in and ->out.
207 */
208 need_in = !cmd->no_stdin && cmd->in < 0;
210 if (need_in) {
211 if (pipe(fdin) < 0) {
212 failed_errno = errno;
213 if (cmd->out > 0)
214 close(cmd->out);
215 goto fail_pipe;
216 }
217 cmd->in = fdin[1];
218 }
219 need_out = !cmd->no_stdout
221 && !cmd->stdout_to_stderr
222 && cmd->out < 0;
223 if (need_out) {
224 if (pipe(fdout) < 0) {
225 failed_errno = errno;
226 if (need_in)
227 close_pair(fdin);
228 else if (cmd->in)
229 close(cmd->in);
230 goto fail_pipe;
231 }
232 cmd->out = fdout[0];
233 }
234 need_err = !cmd->no_stderr && cmd->err < 0;
236 if (need_err) {
237 if (pipe(fderr) < 0) {
238 failed_errno = errno;
239 if (need_in)
240 close_pair(fdin);
241 else if (cmd->in)
242 close(cmd->in);
243 if (need_out)
244 close_pair(fdout);
245 else if (cmd->out)
246 close(cmd->out);
247fail_pipe:
248 error("cannot create pipe for %s: %s",
249 cmd->argv[0], strerror(failed_errno));
250 errno = failed_errno;
251 return -1;
252 }
253 cmd->err = fderr[0];
254 }
255 trace_argv_printf(cmd->argv, "trace: run_command:");
257 fflush(NULL);
258#ifndef WIN32
260{
261 int notify_pipe[2];
262 if (pipe(notify_pipe))
263 notify_pipe[0] = notify_pipe[1] = -1;
264 cmd->pid = fork();
266 if (!cmd->pid) {
267 /*
268 * Redirect the channel to write syscall error messages to
269 * before redirecting the process's stderr so that all die()
270 * in subsequent call paths use the parent's stderr.
271 */
272 if (cmd->no_stderr || need_err) {
273 child_err = dup(2);
274 set_cloexec(child_err);
275 }
276 set_die_routine(die_child);
277 set_error_routine(error_child);
278 close(notify_pipe[0]);
280 set_cloexec(notify_pipe[1]);
281 child_notifier = notify_pipe[1];
282 atexit(notify_parent);
283 if (cmd->no_stdin)
285 dup_devnull(0);
286 else if (need_in) {
287 dup2(fdin[0], 0);
288 close_pair(fdin);
289 } else if (cmd->in) {
290 dup2(cmd->in, 0);
291 close(cmd->in);
292 }
293 if (cmd->no_stderr)
295 dup_devnull(2);
296 else if (need_err) {
297 dup2(fderr[1], 2);
298 close_pair(fderr);
299 } else if (cmd->err > 1) {
300 dup2(cmd->err, 2);
301 close(cmd->err);
302 }
303 if (cmd->no_stdout)
305 dup_devnull(1);
306 else if (cmd->stdout_to_stderr)
307 dup2(2, 1);
308 else if (need_out) {
309 dup2(fdout[1], 1);
310 close_pair(fdout);
311 } else if (cmd->out > 1) {
312 dup2(cmd->out, 1);
313 close(cmd->out);
314 }
315 if (cmd->dir && chdir(cmd->dir))
317 die_errno("exec '%s': cd to '%s' failed", cmd->argv[0],
318 cmd->dir);
319 if (cmd->env) {
320 for (; *cmd->env; cmd->env++) {
321 if (strchr(*cmd->env, '='))
322 putenv((char *)*cmd->env);
323 else
324 unsetenv(*cmd->env);
325 }
326 }
327 if (cmd->preexec_cb) {
328 /*
329 * We cannot predict what the pre-exec callback does.
330 * Forgo parent notification.
331 */
332 close(child_notifier);
333 child_notifier = -1;
334 cmd->preexec_cb();
336 }
337 if (cmd->git_cmd) {
338 execv_git_cmd(cmd->argv);
339 } else if (cmd->use_shell) {
340 execv_shell_cmd(cmd->argv);
341 } else {
342 execvp(cmd->argv[0], (char *const*) cmd->argv);
343 }
344 if (errno == ENOENT) {
345 if (!cmd->silent_exec_failure)
346 error("cannot run %s: %s", cmd->argv[0],
347 strerror(ENOENT));
348 exit(127);
349 } else {
350 die_errno("cannot exec '%s'", cmd->argv[0]);
351 }
352 }
353 if (cmd->pid < 0)
354 error("cannot fork() for %s: %s", cmd->argv[0],
355 strerror(failed_errno = errno));
356 else if (cmd->clean_on_exit)
357 mark_child_for_cleanup(cmd->pid);
358 /*
360 * Wait for child's execvp. If the execvp succeeds (or if fork()
361 * failed), EOF is seen immediately by the parent. Otherwise, the
362 * child process sends a single byte.
363 * Note that use of this infrastructure is completely advisory,
364 * therefore, we keep error checks minimal.
365 */
366 close(notify_pipe[1]);
367 if (read(notify_pipe[0], ¬ify_pipe[1], 1) == 1) {
368 /*
369 * At this point we know that fork() succeeded, but execvp()
370 * failed. Errors have been reported to our stderr.
371 */
372 wait_or_whine(cmd->pid, cmd->argv[0],
373 cmd->silent_exec_failure);
374 failed_errno = errno;
375 cmd->pid = -1;
376 }
377 close(notify_pipe[0]);
378}
380#else
381{
382 int fhin = 0, fhout = 1, fherr = 2;
383 const char **sargv = cmd->argv;
384 char **env = environ;
385 if (cmd->no_stdin)
387 fhin = open("/dev/null", O_RDWR);
388 else if (need_in)
389 fhin = dup(fdin[0]);
390 else if (cmd->in)
391 fhin = dup(cmd->in);
392 if (cmd->no_stderr)
394 fherr = open("/dev/null", O_RDWR);
395 else if (need_err)
396 fherr = dup(fderr[1]);
397 else if (cmd->err > 2)
398 fherr = dup(cmd->err);
399 if (cmd->no_stdout)
401 fhout = open("/dev/null", O_RDWR);
402 else if (cmd->stdout_to_stderr)
403 fhout = dup(fherr);
404 else if (need_out)
405 fhout = dup(fdout[1]);
406 else if (cmd->out > 1)
407 fhout = dup(cmd->out);
408 if (cmd->env)
410 env = make_augmented_environ(cmd->env);
411 if (cmd->git_cmd) {
413 cmd->argv = prepare_git_cmd(cmd->argv);
414 } else if (cmd->use_shell) {
415 cmd->argv = prepare_shell_cmd(cmd->argv);
416 }
417 cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, env, cmd->dir,
419 fhin, fhout, fherr);
420 failed_errno = errno;
421 if (cmd->pid < 0 && (!cmd->silent_exec_failure || errno != ENOENT))
422 error("cannot spawn %s: %s", cmd->argv[0], strerror(errno));
423 if (cmd->clean_on_exit && cmd->pid >= 0)
424 mark_child_for_cleanup(cmd->pid);
425 if (cmd->env)
427 free_environ(env);
428 if (cmd->git_cmd)
429 free(cmd->argv);
430 cmd->argv = sargv;
432 if (fhin != 0)
433 close(fhin);
434 if (fhout != 1)
435 close(fhout);
436 if (fherr != 2)
437 close(fherr);
438}
439#endif
440 if (cmd->pid < 0) {
442 if (need_in)
443 close_pair(fdin);
444 else if (cmd->in)
445 close(cmd->in);
446 if (need_out)
447 close_pair(fdout);
448 else if (cmd->out)
449 close(cmd->out);
450 if (need_err)
451 close_pair(fderr);
452 else if (cmd->err)
453 close(cmd->err);
454 errno = failed_errno;
455 return -1;
456 }
457 if (need_in)
459 close(fdin[0]);
460 else if (cmd->in)
461 close(cmd->in);
462 if (need_out)
464 close(fdout[1]);
465 else if (cmd->out)
466 close(cmd->out);
467 if (need_err)
469 close(fderr[1]);
470 else if (cmd->err)
471 close(cmd->err);
472 return 0;
474}
475int finish_command(struct child_process *cmd)
477{
478 return wait_or_whine(cmd->pid, cmd->argv[0], cmd->silent_exec_failure);
479}
480int run_command(struct child_process *cmd)
482{
483 int code = start_command(cmd);
484 if (code)
485 return code;
486 return finish_command(cmd);
487}
488static void prepare_run_command_v_opt(struct child_process *cmd,
490 const char **argv,
491 int opt)
492{
493 memset(cmd, 0, sizeof(*cmd));
494 cmd->argv = argv;
495 cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
496 cmd->git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
497 cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
498 cmd->silent_exec_failure = opt & RUN_SILENT_EXEC_FAILURE ? 1 : 0;
499 cmd->use_shell = opt & RUN_USING_SHELL ? 1 : 0;
500 cmd->clean_on_exit = opt & RUN_CLEAN_ON_EXIT ? 1 : 0;
501}
502int run_command_v_opt(const char **argv, int opt)
504{
505 struct child_process cmd;
506 prepare_run_command_v_opt(&cmd, argv, opt);
507 return run_command(&cmd);
508}
509int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
511{
512 struct child_process cmd;
513 prepare_run_command_v_opt(&cmd, argv, opt);
514 cmd.dir = dir;
515 cmd.env = env;
516 return run_command(&cmd);
517}
518#ifndef NO_PTHREADS
520static pthread_t main_thread;
521static int main_thread_set;
522static pthread_key_t async_key;
523static void *run_thread(void *data)
525{
526 struct async *async = data;
527 intptr_t ret;
528 pthread_setspecific(async_key, async);
530 ret = async->proc(async->proc_in, async->proc_out, async->data);
531 return (void *)ret;
532}
533static NORETURN void die_async(const char *err, va_list params)
535{
536 vreportf("fatal: ", err, params);
537 if (!pthread_equal(main_thread, pthread_self())) {
539 struct async *async = pthread_getspecific(async_key);
540 if (async->proc_in >= 0)
541 close(async->proc_in);
542 if (async->proc_out >= 0)
543 close(async->proc_out);
544 pthread_exit((void *)128);
545 }
546 exit(128);
548}
549#endif
550int start_async(struct async *async)
552{
553 int need_in, need_out;
554 int fdin[2], fdout[2];
555 int proc_in, proc_out;
556 need_in = async->in < 0;
558 if (need_in) {
559 if (pipe(fdin) < 0) {
560 if (async->out > 0)
561 close(async->out);
562 return error("cannot create pipe: %s", strerror(errno));
563 }
564 async->in = fdin[1];
565 }
566 need_out = async->out < 0;
568 if (need_out) {
569 if (pipe(fdout) < 0) {
570 if (need_in)
571 close_pair(fdin);
572 else if (async->in)
573 close(async->in);
574 return error("cannot create pipe: %s", strerror(errno));
575 }
576 async->out = fdout[0];
577 }
578 if (need_in)
580 proc_in = fdin[0];
581 else if (async->in)
582 proc_in = async->in;
583 else
584 proc_in = -1;
585 if (need_out)
587 proc_out = fdout[1];
588 else if (async->out)
589 proc_out = async->out;
590 else
591 proc_out = -1;
592#ifdef NO_PTHREADS
594 /* Flush stdio before fork() to avoid cloning buffers */
595 fflush(NULL);
596 async->pid = fork();
598 if (async->pid < 0) {
599 error("fork (async) failed: %s", strerror(errno));
600 goto error;
601 }
602 if (!async->pid) {
603 if (need_in)
604 close(fdin[1]);
605 if (need_out)
606 close(fdout[0]);
607 exit(!!async->proc(proc_in, proc_out, async->data));
608 }
609 mark_child_for_cleanup(async->pid);
611 if (need_in)
613 close(fdin[0]);
614 else if (async->in)
615 close(async->in);
616 if (need_out)
618 close(fdout[1]);
619 else if (async->out)
620 close(async->out);
621#else
622 if (!main_thread_set) {
623 /*
624 * We assume that the first time that start_async is called
625 * it is from the main thread.
626 */
627 main_thread_set = 1;
628 main_thread = pthread_self();
629 pthread_key_create(&async_key, NULL);
630 set_die_routine(die_async);
631 }
632 if (proc_in >= 0)
634 set_cloexec(proc_in);
635 if (proc_out >= 0)
636 set_cloexec(proc_out);
637 async->proc_in = proc_in;
638 async->proc_out = proc_out;
639 {
640 int err = pthread_create(&async->tid, NULL, run_thread, async);
641 if (err) {
642 error("cannot create thread: %s", strerror(err));
643 goto error;
644 }
645 }
646#endif
647 return 0;
648error:
650 if (need_in)
651 close_pair(fdin);
652 else if (async->in)
653 close(async->in);
654 if (need_out)
656 close_pair(fdout);
657 else if (async->out)
658 close(async->out);
659 return -1;
660}
661int finish_async(struct async *async)
663{
664#ifdef NO_PTHREADS
665 return wait_or_whine(async->pid, "child process", 0);
666#else
667 void *ret = (void *)(intptr_t)(-1);
668 if (pthread_join(async->tid, &ret))
670 error("pthread_join failed");
671 return (int)(intptr_t)ret;
672#endif
673}
674int run_hook(const char *index_file, const char *name, ...)
676{
677 struct child_process hook;
678 struct argv_array argv = ARGV_ARRAY_INIT;
679 const char *p, *env[2];
680 char index[PATH_MAX];
681 va_list args;
682 int ret;
683 if (access(git_path("hooks/%s", name), X_OK) < 0)
685 return 0;
686 va_start(args, name);
688 argv_array_push(&argv, git_path("hooks/%s", name));
689 while ((p = va_arg(args, const char *)))
690 argv_array_push(&argv, p);
691 va_end(args);
692 memset(&hook, 0, sizeof(hook));
694 hook.argv = argv.argv;
695 hook.no_stdin = 1;
696 hook.stdout_to_stderr = 1;
697 if (index_file) {
698 snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", index_file);
699 env[0] = index;
700 env[1] = NULL;
701 hook.env = env;
702 }
703 ret = run_command(&hook);
705 argv_array_clear(&argv);
706 return ret;
707}