1#include "cache.h"
2#include "run-command.h"
3#include "exec_cmd.h"
4#include "sigchain.h"
5#include "argv-array.h"
6#ifndef SHELL_PATH
8# define SHELL_PATH "/bin/sh"
9#endif
10struct child_to_clean {
12 pid_t pid;
13 struct child_to_clean *next;
14};
15static struct child_to_clean *children_to_clean;
16static int installed_child_cleanup_handler;
17static void cleanup_children(int sig)
19{
20 while (children_to_clean) {
21 struct child_to_clean *p = children_to_clean;
22 children_to_clean = p->next;
23 kill(p->pid, sig);
24 free(p);
25 }
26}
27static void cleanup_children_on_signal(int sig)
29{
30 cleanup_children(sig);
31 sigchain_pop(sig);
32 raise(sig);
33}
34static void cleanup_children_on_exit(void)
36{
37 cleanup_children(SIGTERM);
38}
39static void mark_child_for_cleanup(pid_t pid)
41{
42 struct child_to_clean *p = xmalloc(sizeof(*p));
43 p->pid = pid;
44 p->next = children_to_clean;
45 children_to_clean = p;
46 if (!installed_child_cleanup_handler) {
48 atexit(cleanup_children_on_exit);
49 sigchain_push_common(cleanup_children_on_signal);
50 installed_child_cleanup_handler = 1;
51 }
52}
53static void clear_child_for_cleanup(pid_t pid)
55{
56 struct child_to_clean **pp;
57 for (pp = &children_to_clean; *pp; pp = &(*pp)->next) {
59 struct child_to_clean *clean_me = *pp;
60 if (clean_me->pid == pid) {
62 *pp = clean_me->next;
63 free(clean_me);
64 return;
65 }
66 }
67}
68static inline void close_pair(int fd[2])
70{
71 close(fd[0]);
72 close(fd[1]);
73}
74#ifndef WIN32
76static inline void dup_devnull(int to)
77{
78 int fd = open("/dev/null", O_RDWR);
79 dup2(fd, to);
80 close(fd);
81}
82#endif
83static char *locate_in_PATH(const char *file)
85{
86 const char *p = getenv("PATH");
87 struct strbuf buf = STRBUF_INIT;
88 if (!p || !*p)
90 return NULL;
91 while (1) {
93 const char *end = strchrnul(p, ':');
94 strbuf_reset(&buf);
96 /* POSIX specifies an empty entry as the current directory. */
98 if (end != p) {
99 strbuf_add(&buf, p, end - p);
100 strbuf_addch(&buf, '/');
101 }
102 strbuf_addstr(&buf, file);
103 if (!access(buf.buf, F_OK))
105 return strbuf_detach(&buf, NULL);
106 if (!*end)
108 break;
109 p = end + 1;
110 }
111 strbuf_release(&buf);
113 return NULL;
114}
115static int exists_in_PATH(const char *file)
117{
118 char *r = locate_in_PATH(file);
119 free(r);
120 return r != NULL;
121}
122int sane_execvp(const char *file, char * const argv[])
124{
125 if (!execvp(file, argv))
126 return 0; /* cannot happen ;-) */
127 /*
129 * When a command can't be found because one of the directories
130 * listed in $PATH is unsearchable, execvp reports EACCES, but
131 * careful usability testing (read: analysis of occasional bug
132 * reports) reveals that "No such file or directory" is more
133 * intuitive.
134 *
135 * We avoid commands with "/", because execvp will not do $PATH
136 * lookups in that case.
137 *
138 * The reassignment of EACCES to errno looks like a no-op below,
139 * but we need to protect against exists_in_PATH overwriting errno.
140 */
141 if (errno == EACCES && !strchr(file, '/'))
142 errno = exists_in_PATH(file) ? EACCES : ENOENT;
143 else if (errno == ENOTDIR && !strchr(file, '/'))
144 errno = ENOENT;
145 return -1;
146}
147static const char **prepare_shell_cmd(const char **argv)
149{
150 int argc, nargc = 0;
151 const char **nargv;
152 for (argc = 0; argv[argc]; argc++)
154 ; /* just counting */
155 /* +1 for NULL, +3 for "sh -c" plus extra $0 */
156 nargv = xmalloc(sizeof(*nargv) * (argc + 1 + 3));
157 if (argc < 1)
159 die("BUG: shell command is empty");
160 if (strcspn(argv[0], "|&;<>()$`\\\"' \t\n*?[#~=%") != strlen(argv[0])) {
162#ifndef WIN32
163 nargv[nargc++] = SHELL_PATH;
164#else
165 nargv[nargc++] = "sh";
166#endif
167 nargv[nargc++] = "-c";
168 if (argc < 2)
170 nargv[nargc++] = argv[0];
171 else {
172 struct strbuf arg0 = STRBUF_INIT;
173 strbuf_addf(&arg0, "%s \"$@\"", argv[0]);
174 nargv[nargc++] = strbuf_detach(&arg0, NULL);
175 }
176 }
177 for (argc = 0; argv[argc]; argc++)
179 nargv[nargc++] = argv[argc];
180 nargv[nargc] = NULL;
181 return nargv;
183}
184#ifndef WIN32
186static int execv_shell_cmd(const char **argv)
187{
188 const char **nargv = prepare_shell_cmd(argv);
189 trace_argv_printf(nargv, "trace: exec:");
190 sane_execvp(nargv[0], (char **)nargv);
191 free(nargv);
192 return -1;
193}
194#endif
195#ifndef WIN32
197static int child_err = 2;
198static int child_notifier = -1;
199static void notify_parent(void)
201{
202 /*
203 * execvp failed. If possible, we'd like to let start_command
204 * know, so failures like ENOENT can be handled right away; but
205 * otherwise, finish_command will still report the error.
206 */
207 xwrite(child_notifier, "", 1);
208}
209static NORETURN void die_child(const char *err, va_list params)
211{
212 vwritef(child_err, "fatal: ", err, params);
213 exit(128);
214}
215static void error_child(const char *err, va_list params)
217{
218 vwritef(child_err, "error: ", err, params);
219}
220#endif
221static inline void set_cloexec(int fd)
223{
224 int flags = fcntl(fd, F_GETFD);
225 if (flags >= 0)
226 fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
227}
228static int wait_or_whine(pid_t pid, const char *argv0, int silent_exec_failure)
230{
231 int status, code = -1;
232 pid_t waiting;
233 int failed_errno = 0;
234 while ((waiting = waitpid(pid, &status, 0)) < 0 && errno == EINTR)
236 ; /* nothing */
237 if (waiting < 0) {
239 failed_errno = errno;
240 error("waitpid for %s failed: %s", argv0, strerror(errno));
241 } else if (waiting != pid) {
242 error("waitpid is confused (%s)", argv0);
243 } else if (WIFSIGNALED(status)) {
244 code = WTERMSIG(status);
245 error("%s died of signal %d", argv0, code);
246 /*
247 * This return value is chosen so that code & 0xff
248 * mimics the exit code that a POSIX shell would report for
249 * a program that died from this signal.
250 */
251 code -= 128;
252 } else if (WIFEXITED(status)) {
253 code = WEXITSTATUS(status);
254 /*
255 * Convert special exit code when execvp failed.
256 */
257 if (code == 127) {
258 code = -1;
259 failed_errno = ENOENT;
260 }
261 } else {
262 error("waitpid is confused (%s)", argv0);
263 }
264 clear_child_for_cleanup(pid);
266 errno = failed_errno;
268 return code;
269}
270int start_command(struct child_process *cmd)
272{
273 int need_in, need_out, need_err;
274 int fdin[2], fdout[2], fderr[2];
275 int failed_errno = failed_errno;
276 /*
278 * In case of errors we must keep the promise to close FDs
279 * that have been passed in via ->in and ->out.
280 */
281 need_in = !cmd->no_stdin && cmd->in < 0;
283 if (need_in) {
284 if (pipe(fdin) < 0) {
285 failed_errno = errno;
286 if (cmd->out > 0)
287 close(cmd->out);
288 goto fail_pipe;
289 }
290 cmd->in = fdin[1];
291 }
292 need_out = !cmd->no_stdout
294 && !cmd->stdout_to_stderr
295 && cmd->out < 0;
296 if (need_out) {
297 if (pipe(fdout) < 0) {
298 failed_errno = errno;
299 if (need_in)
300 close_pair(fdin);
301 else if (cmd->in)
302 close(cmd->in);
303 goto fail_pipe;
304 }
305 cmd->out = fdout[0];
306 }
307 need_err = !cmd->no_stderr && cmd->err < 0;
309 if (need_err) {
310 if (pipe(fderr) < 0) {
311 failed_errno = errno;
312 if (need_in)
313 close_pair(fdin);
314 else if (cmd->in)
315 close(cmd->in);
316 if (need_out)
317 close_pair(fdout);
318 else if (cmd->out)
319 close(cmd->out);
320fail_pipe:
321 error("cannot create pipe for %s: %s",
322 cmd->argv[0], strerror(failed_errno));
323 errno = failed_errno;
324 return -1;
325 }
326 cmd->err = fderr[0];
327 }
328 trace_argv_printf(cmd->argv, "trace: run_command:");
330 fflush(NULL);
331#ifndef WIN32
333{
334 int notify_pipe[2];
335 if (pipe(notify_pipe))
336 notify_pipe[0] = notify_pipe[1] = -1;
337 cmd->pid = fork();
339 if (!cmd->pid) {
340 /*
341 * Redirect the channel to write syscall error messages to
342 * before redirecting the process's stderr so that all die()
343 * in subsequent call paths use the parent's stderr.
344 */
345 if (cmd->no_stderr || need_err) {
346 child_err = dup(2);
347 set_cloexec(child_err);
348 }
349 set_die_routine(die_child);
350 set_error_routine(error_child);
351 close(notify_pipe[0]);
353 set_cloexec(notify_pipe[1]);
354 child_notifier = notify_pipe[1];
355 atexit(notify_parent);
356 if (cmd->no_stdin)
358 dup_devnull(0);
359 else if (need_in) {
360 dup2(fdin[0], 0);
361 close_pair(fdin);
362 } else if (cmd->in) {
363 dup2(cmd->in, 0);
364 close(cmd->in);
365 }
366 if (cmd->no_stderr)
368 dup_devnull(2);
369 else if (need_err) {
370 dup2(fderr[1], 2);
371 close_pair(fderr);
372 } else if (cmd->err > 1) {
373 dup2(cmd->err, 2);
374 close(cmd->err);
375 }
376 if (cmd->no_stdout)
378 dup_devnull(1);
379 else if (cmd->stdout_to_stderr)
380 dup2(2, 1);
381 else if (need_out) {
382 dup2(fdout[1], 1);
383 close_pair(fdout);
384 } else if (cmd->out > 1) {
385 dup2(cmd->out, 1);
386 close(cmd->out);
387 }
388 if (cmd->dir && chdir(cmd->dir))
390 die_errno("exec '%s': cd to '%s' failed", cmd->argv[0],
391 cmd->dir);
392 if (cmd->env) {
393 for (; *cmd->env; cmd->env++) {
394 if (strchr(*cmd->env, '='))
395 putenv((char *)*cmd->env);
396 else
397 unsetenv(*cmd->env);
398 }
399 }
400 if (cmd->git_cmd) {
401 execv_git_cmd(cmd->argv);
402 } else if (cmd->use_shell) {
403 execv_shell_cmd(cmd->argv);
404 } else {
405 sane_execvp(cmd->argv[0], (char *const*) cmd->argv);
406 }
407 if (errno == ENOENT) {
408 if (!cmd->silent_exec_failure)
409 error("cannot run %s: %s", cmd->argv[0],
410 strerror(ENOENT));
411 exit(127);
412 } else {
413 die_errno("cannot exec '%s'", cmd->argv[0]);
414 }
415 }
416 if (cmd->pid < 0)
417 error("cannot fork() for %s: %s", cmd->argv[0],
418 strerror(failed_errno = errno));
419 else if (cmd->clean_on_exit)
420 mark_child_for_cleanup(cmd->pid);
421 /*
423 * Wait for child's execvp. If the execvp succeeds (or if fork()
424 * failed), EOF is seen immediately by the parent. Otherwise, the
425 * child process sends a single byte.
426 * Note that use of this infrastructure is completely advisory,
427 * therefore, we keep error checks minimal.
428 */
429 close(notify_pipe[1]);
430 if (read(notify_pipe[0], ¬ify_pipe[1], 1) == 1) {
431 /*
432 * At this point we know that fork() succeeded, but execvp()
433 * failed. Errors have been reported to our stderr.
434 */
435 wait_or_whine(cmd->pid, cmd->argv[0],
436 cmd->silent_exec_failure);
437 failed_errno = errno;
438 cmd->pid = -1;
439 }
440 close(notify_pipe[0]);
441}
443#else
444{
445 int fhin = 0, fhout = 1, fherr = 2;
446 const char **sargv = cmd->argv;
447 char **env = environ;
448 if (cmd->no_stdin)
450 fhin = open("/dev/null", O_RDWR);
451 else if (need_in)
452 fhin = dup(fdin[0]);
453 else if (cmd->in)
454 fhin = dup(cmd->in);
455 if (cmd->no_stderr)
457 fherr = open("/dev/null", O_RDWR);
458 else if (need_err)
459 fherr = dup(fderr[1]);
460 else if (cmd->err > 2)
461 fherr = dup(cmd->err);
462 if (cmd->no_stdout)
464 fhout = open("/dev/null", O_RDWR);
465 else if (cmd->stdout_to_stderr)
466 fhout = dup(fherr);
467 else if (need_out)
468 fhout = dup(fdout[1]);
469 else if (cmd->out > 1)
470 fhout = dup(cmd->out);
471 if (cmd->env)
473 env = make_augmented_environ(cmd->env);
474 if (cmd->git_cmd) {
476 cmd->argv = prepare_git_cmd(cmd->argv);
477 } else if (cmd->use_shell) {
478 cmd->argv = prepare_shell_cmd(cmd->argv);
479 }
480 cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, env, cmd->dir,
482 fhin, fhout, fherr);
483 failed_errno = errno;
484 if (cmd->pid < 0 && (!cmd->silent_exec_failure || errno != ENOENT))
485 error("cannot spawn %s: %s", cmd->argv[0], strerror(errno));
486 if (cmd->clean_on_exit && cmd->pid >= 0)
487 mark_child_for_cleanup(cmd->pid);
488 if (cmd->env)
490 free_environ(env);
491 if (cmd->git_cmd)
492 free(cmd->argv);
493 cmd->argv = sargv;
495 if (fhin != 0)
496 close(fhin);
497 if (fhout != 1)
498 close(fhout);
499 if (fherr != 2)
500 close(fherr);
501}
502#endif
503 if (cmd->pid < 0) {
505 if (need_in)
506 close_pair(fdin);
507 else if (cmd->in)
508 close(cmd->in);
509 if (need_out)
510 close_pair(fdout);
511 else if (cmd->out)
512 close(cmd->out);
513 if (need_err)
514 close_pair(fderr);
515 else if (cmd->err)
516 close(cmd->err);
517 errno = failed_errno;
518 return -1;
519 }
520 if (need_in)
522 close(fdin[0]);
523 else if (cmd->in)
524 close(cmd->in);
525 if (need_out)
527 close(fdout[1]);
528 else if (cmd->out)
529 close(cmd->out);
530 if (need_err)
532 close(fderr[1]);
533 else if (cmd->err)
534 close(cmd->err);
535 return 0;
537}
538int finish_command(struct child_process *cmd)
540{
541 return wait_or_whine(cmd->pid, cmd->argv[0], cmd->silent_exec_failure);
542}
543int run_command(struct child_process *cmd)
545{
546 int code = start_command(cmd);
547 if (code)
548 return code;
549 return finish_command(cmd);
550}
551static void prepare_run_command_v_opt(struct child_process *cmd,
553 const char **argv,
554 int opt)
555{
556 memset(cmd, 0, sizeof(*cmd));
557 cmd->argv = argv;
558 cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
559 cmd->git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
560 cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
561 cmd->silent_exec_failure = opt & RUN_SILENT_EXEC_FAILURE ? 1 : 0;
562 cmd->use_shell = opt & RUN_USING_SHELL ? 1 : 0;
563 cmd->clean_on_exit = opt & RUN_CLEAN_ON_EXIT ? 1 : 0;
564}
565int run_command_v_opt(const char **argv, int opt)
567{
568 struct child_process cmd;
569 prepare_run_command_v_opt(&cmd, argv, opt);
570 return run_command(&cmd);
571}
572int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
574{
575 struct child_process cmd;
576 prepare_run_command_v_opt(&cmd, argv, opt);
577 cmd.dir = dir;
578 cmd.env = env;
579 return run_command(&cmd);
580}
581#ifndef NO_PTHREADS
583static pthread_t main_thread;
584static int main_thread_set;
585static pthread_key_t async_key;
586static void *run_thread(void *data)
588{
589 struct async *async = data;
590 intptr_t ret;
591 pthread_setspecific(async_key, async);
593 ret = async->proc(async->proc_in, async->proc_out, async->data);
594 return (void *)ret;
595}
596static NORETURN void die_async(const char *err, va_list params)
598{
599 vreportf("fatal: ", err, params);
600 if (!pthread_equal(main_thread, pthread_self())) {
602 struct async *async = pthread_getspecific(async_key);
603 if (async->proc_in >= 0)
604 close(async->proc_in);
605 if (async->proc_out >= 0)
606 close(async->proc_out);
607 pthread_exit((void *)128);
608 }
609 exit(128);
611}
612#endif
613int start_async(struct async *async)
615{
616 int need_in, need_out;
617 int fdin[2], fdout[2];
618 int proc_in, proc_out;
619 need_in = async->in < 0;
621 if (need_in) {
622 if (pipe(fdin) < 0) {
623 if (async->out > 0)
624 close(async->out);
625 return error("cannot create pipe: %s", strerror(errno));
626 }
627 async->in = fdin[1];
628 }
629 need_out = async->out < 0;
631 if (need_out) {
632 if (pipe(fdout) < 0) {
633 if (need_in)
634 close_pair(fdin);
635 else if (async->in)
636 close(async->in);
637 return error("cannot create pipe: %s", strerror(errno));
638 }
639 async->out = fdout[0];
640 }
641 if (need_in)
643 proc_in = fdin[0];
644 else if (async->in)
645 proc_in = async->in;
646 else
647 proc_in = -1;
648 if (need_out)
650 proc_out = fdout[1];
651 else if (async->out)
652 proc_out = async->out;
653 else
654 proc_out = -1;
655#ifdef NO_PTHREADS
657 /* Flush stdio before fork() to avoid cloning buffers */
658 fflush(NULL);
659 async->pid = fork();
661 if (async->pid < 0) {
662 error("fork (async) failed: %s", strerror(errno));
663 goto error;
664 }
665 if (!async->pid) {
666 if (need_in)
667 close(fdin[1]);
668 if (need_out)
669 close(fdout[0]);
670 exit(!!async->proc(proc_in, proc_out, async->data));
671 }
672 mark_child_for_cleanup(async->pid);
674 if (need_in)
676 close(fdin[0]);
677 else if (async->in)
678 close(async->in);
679 if (need_out)
681 close(fdout[1]);
682 else if (async->out)
683 close(async->out);
684#else
685 if (!main_thread_set) {
686 /*
687 * We assume that the first time that start_async is called
688 * it is from the main thread.
689 */
690 main_thread_set = 1;
691 main_thread = pthread_self();
692 pthread_key_create(&async_key, NULL);
693 set_die_routine(die_async);
694 }
695 if (proc_in >= 0)
697 set_cloexec(proc_in);
698 if (proc_out >= 0)
699 set_cloexec(proc_out);
700 async->proc_in = proc_in;
701 async->proc_out = proc_out;
702 {
703 int err = pthread_create(&async->tid, NULL, run_thread, async);
704 if (err) {
705 error("cannot create thread: %s", strerror(err));
706 goto error;
707 }
708 }
709#endif
710 return 0;
711error:
713 if (need_in)
714 close_pair(fdin);
715 else if (async->in)
716 close(async->in);
717 if (need_out)
719 close_pair(fdout);
720 else if (async->out)
721 close(async->out);
722 return -1;
723}
724int finish_async(struct async *async)
726{
727#ifdef NO_PTHREADS
728 return wait_or_whine(async->pid, "child process", 0);
729#else
730 void *ret = (void *)(intptr_t)(-1);
731 if (pthread_join(async->tid, &ret))
733 error("pthread_join failed");
734 return (int)(intptr_t)ret;
735#endif
736}
737int run_hook(const char *index_file, const char *name, ...)
739{
740 struct child_process hook;
741 struct argv_array argv = ARGV_ARRAY_INIT;
742 const char *p, *env[2];
743 char index[PATH_MAX];
744 va_list args;
745 int ret;
746 if (access(git_path("hooks/%s", name), X_OK) < 0)
748 return 0;
749 va_start(args, name);
751 argv_array_push(&argv, git_path("hooks/%s", name));
752 while ((p = va_arg(args, const char *)))
753 argv_array_push(&argv, p);
754 va_end(args);
755 memset(&hook, 0, sizeof(hook));
757 hook.argv = argv.argv;
758 hook.no_stdin = 1;
759 hook.stdout_to_stderr = 1;
760 if (index_file) {
761 snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", index_file);
762 env[0] = index;
763 env[1] = NULL;
764 hook.env = env;
765 }
766 ret = run_command(&hook);
768 argv_array_clear(&argv);
769 return ret;
770}