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 **last, *p;
57 last = &children_to_clean;
59 for (p = children_to_clean; p; p = p->next) {
60 if (p->pid == pid) {
61 *last = p->next;
62 free(p);
63 return;
64 }
65 }
66}
67static inline void close_pair(int fd[2])
69{
70 close(fd[0]);
71 close(fd[1]);
72}
73#ifndef WIN32
75static inline void dup_devnull(int to)
76{
77 int fd = open("/dev/null", O_RDWR);
78 dup2(fd, to);
79 close(fd);
80}
81#endif
82static const char **prepare_shell_cmd(const char **argv)
84{
85 int argc, nargc = 0;
86 const char **nargv;
87 for (argc = 0; argv[argc]; argc++)
89 ; /* just counting */
90 /* +1 for NULL, +3 for "sh -c" plus extra $0 */
91 nargv = xmalloc(sizeof(*nargv) * (argc + 1 + 3));
92 if (argc < 1)
94 die("BUG: shell command is empty");
95 if (strcspn(argv[0], "|&;<>()$`\\\"' \t\n*?[#~=%") != strlen(argv[0])) {
97#ifndef WIN32
98 nargv[nargc++] = SHELL_PATH;
99#else
100 nargv[nargc++] = "sh";
101#endif
102 nargv[nargc++] = "-c";
103 if (argc < 2)
105 nargv[nargc++] = argv[0];
106 else {
107 struct strbuf arg0 = STRBUF_INIT;
108 strbuf_addf(&arg0, "%s \"$@\"", argv[0]);
109 nargv[nargc++] = strbuf_detach(&arg0, NULL);
110 }
111 }
112 for (argc = 0; argv[argc]; argc++)
114 nargv[nargc++] = argv[argc];
115 nargv[nargc] = NULL;
116 return nargv;
118}
119#ifndef WIN32
121static int execv_shell_cmd(const char **argv)
122{
123 const char **nargv = prepare_shell_cmd(argv);
124 trace_argv_printf(nargv, "trace: exec:");
125 execvp(nargv[0], (char **)nargv);
126 free(nargv);
127 return -1;
128}
129#endif
130#ifndef WIN32
132static int child_err = 2;
133static int child_notifier = -1;
134static void notify_parent(void)
136{
137 /*
138 * execvp failed. If possible, we'd like to let start_command
139 * know, so failures like ENOENT can be handled right away; but
140 * otherwise, finish_command will still report the error.
141 */
142 xwrite(child_notifier, "", 1);
143}
144static NORETURN void die_child(const char *err, va_list params)
146{
147 vwritef(child_err, "fatal: ", err, params);
148 exit(128);
149}
150static void error_child(const char *err, va_list params)
152{
153 vwritef(child_err, "error: ", err, params);
154}
155#endif
156static inline void set_cloexec(int fd)
158{
159 int flags = fcntl(fd, F_GETFD);
160 if (flags >= 0)
161 fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
162}
163static int wait_or_whine(pid_t pid, const char *argv0, int silent_exec_failure)
165{
166 int status, code = -1;
167 pid_t waiting;
168 int failed_errno = 0;
169 while ((waiting = waitpid(pid, &status, 0)) < 0 && errno == EINTR)
171 ; /* nothing */
172 if (waiting < 0) {
174 failed_errno = errno;
175 error("waitpid for %s failed: %s", argv0, strerror(errno));
176 } else if (waiting != pid) {
177 error("waitpid is confused (%s)", argv0);
178 } else if (WIFSIGNALED(status)) {
179 code = WTERMSIG(status);
180 error("%s died of signal %d", argv0, code);
181 /*
182 * This return value is chosen so that code & 0xff
183 * mimics the exit code that a POSIX shell would report for
184 * a program that died from this signal.
185 */
186 code -= 128;
187 } else if (WIFEXITED(status)) {
188 code = WEXITSTATUS(status);
189 /*
190 * Convert special exit code when execvp failed.
191 */
192 if (code == 127) {
193 code = -1;
194 failed_errno = ENOENT;
195 }
196 } else {
197 error("waitpid is confused (%s)", argv0);
198 }
199 clear_child_for_cleanup(pid);
201 errno = failed_errno;
203 return code;
204}
205int start_command(struct child_process *cmd)
207{
208 int need_in, need_out, need_err;
209 int fdin[2], fdout[2], fderr[2];
210 int failed_errno = failed_errno;
211 /*
213 * In case of errors we must keep the promise to close FDs
214 * that have been passed in via ->in and ->out.
215 */
216 need_in = !cmd->no_stdin && cmd->in < 0;
218 if (need_in) {
219 if (pipe(fdin) < 0) {
220 failed_errno = errno;
221 if (cmd->out > 0)
222 close(cmd->out);
223 goto fail_pipe;
224 }
225 cmd->in = fdin[1];
226 }
227 need_out = !cmd->no_stdout
229 && !cmd->stdout_to_stderr
230 && cmd->out < 0;
231 if (need_out) {
232 if (pipe(fdout) < 0) {
233 failed_errno = errno;
234 if (need_in)
235 close_pair(fdin);
236 else if (cmd->in)
237 close(cmd->in);
238 goto fail_pipe;
239 }
240 cmd->out = fdout[0];
241 }
242 need_err = !cmd->no_stderr && cmd->err < 0;
244 if (need_err) {
245 if (pipe(fderr) < 0) {
246 failed_errno = errno;
247 if (need_in)
248 close_pair(fdin);
249 else if (cmd->in)
250 close(cmd->in);
251 if (need_out)
252 close_pair(fdout);
253 else if (cmd->out)
254 close(cmd->out);
255fail_pipe:
256 error("cannot create pipe for %s: %s",
257 cmd->argv[0], strerror(failed_errno));
258 errno = failed_errno;
259 return -1;
260 }
261 cmd->err = fderr[0];
262 }
263 trace_argv_printf(cmd->argv, "trace: run_command:");
265 fflush(NULL);
266#ifndef WIN32
268{
269 int notify_pipe[2];
270 if (pipe(notify_pipe))
271 notify_pipe[0] = notify_pipe[1] = -1;
272 cmd->pid = fork();
274 if (!cmd->pid) {
275 /*
276 * Redirect the channel to write syscall error messages to
277 * before redirecting the process's stderr so that all die()
278 * in subsequent call paths use the parent's stderr.
279 */
280 if (cmd->no_stderr || need_err) {
281 child_err = dup(2);
282 set_cloexec(child_err);
283 }
284 set_die_routine(die_child);
285 set_error_routine(error_child);
286 close(notify_pipe[0]);
288 set_cloexec(notify_pipe[1]);
289 child_notifier = notify_pipe[1];
290 atexit(notify_parent);
291 if (cmd->no_stdin)
293 dup_devnull(0);
294 else if (need_in) {
295 dup2(fdin[0], 0);
296 close_pair(fdin);
297 } else if (cmd->in) {
298 dup2(cmd->in, 0);
299 close(cmd->in);
300 }
301 if (cmd->no_stderr)
303 dup_devnull(2);
304 else if (need_err) {
305 dup2(fderr[1], 2);
306 close_pair(fderr);
307 } else if (cmd->err > 1) {
308 dup2(cmd->err, 2);
309 close(cmd->err);
310 }
311 if (cmd->no_stdout)
313 dup_devnull(1);
314 else if (cmd->stdout_to_stderr)
315 dup2(2, 1);
316 else if (need_out) {
317 dup2(fdout[1], 1);
318 close_pair(fdout);
319 } else if (cmd->out > 1) {
320 dup2(cmd->out, 1);
321 close(cmd->out);
322 }
323 if (cmd->dir && chdir(cmd->dir))
325 die_errno("exec '%s': cd to '%s' failed", cmd->argv[0],
326 cmd->dir);
327 if (cmd->env) {
328 for (; *cmd->env; cmd->env++) {
329 if (strchr(*cmd->env, '='))
330 putenv((char *)*cmd->env);
331 else
332 unsetenv(*cmd->env);
333 }
334 }
335 if (cmd->preexec_cb) {
336 /*
337 * We cannot predict what the pre-exec callback does.
338 * Forgo parent notification.
339 */
340 close(child_notifier);
341 child_notifier = -1;
342 cmd->preexec_cb();
344 }
345 if (cmd->git_cmd) {
346 execv_git_cmd(cmd->argv);
347 } else if (cmd->use_shell) {
348 execv_shell_cmd(cmd->argv);
349 } else {
350 execvp(cmd->argv[0], (char *const*) cmd->argv);
351 }
352 if (errno == ENOENT) {
353 if (!cmd->silent_exec_failure)
354 error("cannot run %s: %s", cmd->argv[0],
355 strerror(ENOENT));
356 exit(127);
357 } else {
358 die_errno("cannot exec '%s'", cmd->argv[0]);
359 }
360 }
361 if (cmd->pid < 0)
362 error("cannot fork() for %s: %s", cmd->argv[0],
363 strerror(failed_errno = errno));
364 else if (cmd->clean_on_exit)
365 mark_child_for_cleanup(cmd->pid);
366 /*
368 * Wait for child's execvp. If the execvp succeeds (or if fork()
369 * failed), EOF is seen immediately by the parent. Otherwise, the
370 * child process sends a single byte.
371 * Note that use of this infrastructure is completely advisory,
372 * therefore, we keep error checks minimal.
373 */
374 close(notify_pipe[1]);
375 if (read(notify_pipe[0], ¬ify_pipe[1], 1) == 1) {
376 /*
377 * At this point we know that fork() succeeded, but execvp()
378 * failed. Errors have been reported to our stderr.
379 */
380 wait_or_whine(cmd->pid, cmd->argv[0],
381 cmd->silent_exec_failure);
382 failed_errno = errno;
383 cmd->pid = -1;
384 }
385 close(notify_pipe[0]);
386}
388#else
389{
390 int fhin = 0, fhout = 1, fherr = 2;
391 const char **sargv = cmd->argv;
392 char **env = environ;
393 if (cmd->no_stdin)
395 fhin = open("/dev/null", O_RDWR);
396 else if (need_in)
397 fhin = dup(fdin[0]);
398 else if (cmd->in)
399 fhin = dup(cmd->in);
400 if (cmd->no_stderr)
402 fherr = open("/dev/null", O_RDWR);
403 else if (need_err)
404 fherr = dup(fderr[1]);
405 else if (cmd->err > 2)
406 fherr = dup(cmd->err);
407 if (cmd->no_stdout)
409 fhout = open("/dev/null", O_RDWR);
410 else if (cmd->stdout_to_stderr)
411 fhout = dup(fherr);
412 else if (need_out)
413 fhout = dup(fdout[1]);
414 else if (cmd->out > 1)
415 fhout = dup(cmd->out);
416 if (cmd->env)
418 env = make_augmented_environ(cmd->env);
419 if (cmd->git_cmd) {
421 cmd->argv = prepare_git_cmd(cmd->argv);
422 } else if (cmd->use_shell) {
423 cmd->argv = prepare_shell_cmd(cmd->argv);
424 }
425 cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, env, cmd->dir,
427 fhin, fhout, fherr);
428 failed_errno = errno;
429 if (cmd->pid < 0 && (!cmd->silent_exec_failure || errno != ENOENT))
430 error("cannot spawn %s: %s", cmd->argv[0], strerror(errno));
431 if (cmd->clean_on_exit && cmd->pid >= 0)
432 mark_child_for_cleanup(cmd->pid);
433 if (cmd->env)
435 free_environ(env);
436 if (cmd->git_cmd)
437 free(cmd->argv);
438 cmd->argv = sargv;
440 if (fhin != 0)
441 close(fhin);
442 if (fhout != 1)
443 close(fhout);
444 if (fherr != 2)
445 close(fherr);
446}
447#endif
448 if (cmd->pid < 0) {
450 if (need_in)
451 close_pair(fdin);
452 else if (cmd->in)
453 close(cmd->in);
454 if (need_out)
455 close_pair(fdout);
456 else if (cmd->out)
457 close(cmd->out);
458 if (need_err)
459 close_pair(fderr);
460 else if (cmd->err)
461 close(cmd->err);
462 errno = failed_errno;
463 return -1;
464 }
465 if (need_in)
467 close(fdin[0]);
468 else if (cmd->in)
469 close(cmd->in);
470 if (need_out)
472 close(fdout[1]);
473 else if (cmd->out)
474 close(cmd->out);
475 if (need_err)
477 close(fderr[1]);
478 else if (cmd->err)
479 close(cmd->err);
480 return 0;
482}
483int finish_command(struct child_process *cmd)
485{
486 return wait_or_whine(cmd->pid, cmd->argv[0], cmd->silent_exec_failure);
487}
488int run_command(struct child_process *cmd)
490{
491 int code = start_command(cmd);
492 if (code)
493 return code;
494 return finish_command(cmd);
495}
496static void prepare_run_command_v_opt(struct child_process *cmd,
498 const char **argv,
499 int opt)
500{
501 memset(cmd, 0, sizeof(*cmd));
502 cmd->argv = argv;
503 cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
504 cmd->git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
505 cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
506 cmd->silent_exec_failure = opt & RUN_SILENT_EXEC_FAILURE ? 1 : 0;
507 cmd->use_shell = opt & RUN_USING_SHELL ? 1 : 0;
508 cmd->clean_on_exit = opt & RUN_CLEAN_ON_EXIT ? 1 : 0;
509}
510int run_command_v_opt(const char **argv, int opt)
512{
513 struct child_process cmd;
514 prepare_run_command_v_opt(&cmd, argv, opt);
515 return run_command(&cmd);
516}
517int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
519{
520 struct child_process cmd;
521 prepare_run_command_v_opt(&cmd, argv, opt);
522 cmd.dir = dir;
523 cmd.env = env;
524 return run_command(&cmd);
525}
526#ifndef NO_PTHREADS
528static pthread_t main_thread;
529static int main_thread_set;
530static pthread_key_t async_key;
531static void *run_thread(void *data)
533{
534 struct async *async = data;
535 intptr_t ret;
536 pthread_setspecific(async_key, async);
538 ret = async->proc(async->proc_in, async->proc_out, async->data);
539 return (void *)ret;
540}
541static NORETURN void die_async(const char *err, va_list params)
543{
544 vreportf("fatal: ", err, params);
545 if (!pthread_equal(main_thread, pthread_self())) {
547 struct async *async = pthread_getspecific(async_key);
548 if (async->proc_in >= 0)
549 close(async->proc_in);
550 if (async->proc_out >= 0)
551 close(async->proc_out);
552 pthread_exit((void *)128);
553 }
554 exit(128);
556}
557#endif
558int start_async(struct async *async)
560{
561 int need_in, need_out;
562 int fdin[2], fdout[2];
563 int proc_in, proc_out;
564 need_in = async->in < 0;
566 if (need_in) {
567 if (pipe(fdin) < 0) {
568 if (async->out > 0)
569 close(async->out);
570 return error("cannot create pipe: %s", strerror(errno));
571 }
572 async->in = fdin[1];
573 }
574 need_out = async->out < 0;
576 if (need_out) {
577 if (pipe(fdout) < 0) {
578 if (need_in)
579 close_pair(fdin);
580 else if (async->in)
581 close(async->in);
582 return error("cannot create pipe: %s", strerror(errno));
583 }
584 async->out = fdout[0];
585 }
586 if (need_in)
588 proc_in = fdin[0];
589 else if (async->in)
590 proc_in = async->in;
591 else
592 proc_in = -1;
593 if (need_out)
595 proc_out = fdout[1];
596 else if (async->out)
597 proc_out = async->out;
598 else
599 proc_out = -1;
600#ifdef NO_PTHREADS
602 /* Flush stdio before fork() to avoid cloning buffers */
603 fflush(NULL);
604 async->pid = fork();
606 if (async->pid < 0) {
607 error("fork (async) failed: %s", strerror(errno));
608 goto error;
609 }
610 if (!async->pid) {
611 if (need_in)
612 close(fdin[1]);
613 if (need_out)
614 close(fdout[0]);
615 exit(!!async->proc(proc_in, proc_out, async->data));
616 }
617 mark_child_for_cleanup(async->pid);
619 if (need_in)
621 close(fdin[0]);
622 else if (async->in)
623 close(async->in);
624 if (need_out)
626 close(fdout[1]);
627 else if (async->out)
628 close(async->out);
629#else
630 if (!main_thread_set) {
631 /*
632 * We assume that the first time that start_async is called
633 * it is from the main thread.
634 */
635 main_thread_set = 1;
636 main_thread = pthread_self();
637 pthread_key_create(&async_key, NULL);
638 set_die_routine(die_async);
639 }
640 if (proc_in >= 0)
642 set_cloexec(proc_in);
643 if (proc_out >= 0)
644 set_cloexec(proc_out);
645 async->proc_in = proc_in;
646 async->proc_out = proc_out;
647 {
648 int err = pthread_create(&async->tid, NULL, run_thread, async);
649 if (err) {
650 error("cannot create thread: %s", strerror(err));
651 goto error;
652 }
653 }
654#endif
655 return 0;
656error:
658 if (need_in)
659 close_pair(fdin);
660 else if (async->in)
661 close(async->in);
662 if (need_out)
664 close_pair(fdout);
665 else if (async->out)
666 close(async->out);
667 return -1;
668}
669int finish_async(struct async *async)
671{
672#ifdef NO_PTHREADS
673 return wait_or_whine(async->pid, "child process", 0);
674#else
675 void *ret = (void *)(intptr_t)(-1);
676 if (pthread_join(async->tid, &ret))
678 error("pthread_join failed");
679 return (int)(intptr_t)ret;
680#endif
681}
682int run_hook(const char *index_file, const char *name, ...)
684{
685 struct child_process hook;
686 struct argv_array argv = ARGV_ARRAY_INIT;
687 const char *p, *env[2];
688 char index[PATH_MAX];
689 va_list args;
690 int ret;
691 if (access(git_path("hooks/%s", name), X_OK) < 0)
693 return 0;
694 va_start(args, name);
696 argv_array_push(&argv, git_path("hooks/%s", name));
697 while ((p = va_arg(args, const char *)))
698 argv_array_push(&argv, p);
699 va_end(args);
700 memset(&hook, 0, sizeof(hook));
702 hook.argv = argv.argv;
703 hook.no_stdin = 1;
704 hook.stdout_to_stderr = 1;
705 if (index_file) {
706 snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", index_file);
707 env[0] = index;
708 env[1] = NULL;
709 hook.env = env;
710 }
711 ret = run_command(&hook);
713 argv_array_clear(&argv);
714 return ret;
715}