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 **pp;
53 for (pp = &children_to_clean; *pp; pp = &(*pp)->next) {
55 struct child_to_clean *clean_me = *pp;
56 if (clean_me->pid == pid) {
58 *pp = clean_me->next;
59 free(clean_me);
60 return;
61 }
62 }
63}
64static inline void close_pair(int fd[2])
66{
67 close(fd[0]);
68 close(fd[1]);
69}
70#ifndef WIN32
72static inline void dup_devnull(int to)
73{
74 int fd = open("/dev/null", O_RDWR);
75 dup2(fd, to);
76 close(fd);
77}
78#endif
79static const char **prepare_shell_cmd(const char **argv)
81{
82 int argc, nargc = 0;
83 const char **nargv;
84 for (argc = 0; argv[argc]; argc++)
86 ; /* just counting */
87 /* +1 for NULL, +3 for "sh -c" plus extra $0 */
88 nargv = xmalloc(sizeof(*nargv) * (argc + 1 + 3));
89 if (argc < 1)
91 die("BUG: shell command is empty");
92 if (strcspn(argv[0], "|&;<>()$`\\\"' \t\n*?[#~=%") != strlen(argv[0])) {
94 nargv[nargc++] = "sh";
95 nargv[nargc++] = "-c";
96 if (argc < 2)
98 nargv[nargc++] = argv[0];
99 else {
100 struct strbuf arg0 = STRBUF_INIT;
101 strbuf_addf(&arg0, "%s \"$@\"", argv[0]);
102 nargv[nargc++] = strbuf_detach(&arg0, NULL);
103 }
104 }
105 for (argc = 0; argv[argc]; argc++)
107 nargv[nargc++] = argv[argc];
108 nargv[nargc] = NULL;
109 return nargv;
111}
112#ifndef WIN32
114static int execv_shell_cmd(const char **argv)
115{
116 const char **nargv = prepare_shell_cmd(argv);
117 trace_argv_printf(nargv, "trace: exec:");
118 execvp(nargv[0], (char **)nargv);
119 free(nargv);
120 return -1;
121}
122#endif
123#ifndef WIN32
125static int child_err = 2;
126static int child_notifier = -1;
127static void notify_parent(void)
129{
130 /*
131 * execvp failed. If possible, we'd like to let start_command
132 * know, so failures like ENOENT can be handled right away; but
133 * otherwise, finish_command will still report the error.
134 */
135 xwrite(child_notifier, "", 1);
136}
137static NORETURN void die_child(const char *err, va_list params)
139{
140 vwritef(child_err, "fatal: ", err, params);
141 exit(128);
142}
143static void error_child(const char *err, va_list params)
145{
146 vwritef(child_err, "error: ", err, params);
147}
148#endif
149static inline void set_cloexec(int fd)
151{
152 int flags = fcntl(fd, F_GETFD);
153 if (flags >= 0)
154 fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
155}
156static int wait_or_whine(pid_t pid, const char *argv0, int silent_exec_failure)
158{
159 int status, code = -1;
160 pid_t waiting;
161 int failed_errno = 0;
162 while ((waiting = waitpid(pid, &status, 0)) < 0 && errno == EINTR)
164 ; /* nothing */
165 if (waiting < 0) {
167 failed_errno = errno;
168 error("waitpid for %s failed: %s", argv0, strerror(errno));
169 } else if (waiting != pid) {
170 error("waitpid is confused (%s)", argv0);
171 } else if (WIFSIGNALED(status)) {
172 code = WTERMSIG(status);
173 error("%s died of signal %d", argv0, code);
174 /*
175 * This return value is chosen so that code & 0xff
176 * mimics the exit code that a POSIX shell would report for
177 * a program that died from this signal.
178 */
179 code -= 128;
180 } else if (WIFEXITED(status)) {
181 code = WEXITSTATUS(status);
182 /*
183 * Convert special exit code when execvp failed.
184 */
185 if (code == 127) {
186 code = -1;
187 failed_errno = ENOENT;
188 }
189 } else {
190 error("waitpid is confused (%s)", argv0);
191 }
192 clear_child_for_cleanup(pid);
194 errno = failed_errno;
196 return code;
197}
198int start_command(struct child_process *cmd)
200{
201 int need_in, need_out, need_err;
202 int fdin[2], fdout[2], fderr[2];
203 int failed_errno = failed_errno;
204 /*
206 * In case of errors we must keep the promise to close FDs
207 * that have been passed in via ->in and ->out.
208 */
209 need_in = !cmd->no_stdin && cmd->in < 0;
211 if (need_in) {
212 if (pipe(fdin) < 0) {
213 failed_errno = errno;
214 if (cmd->out > 0)
215 close(cmd->out);
216 goto fail_pipe;
217 }
218 cmd->in = fdin[1];
219 }
220 need_out = !cmd->no_stdout
222 && !cmd->stdout_to_stderr
223 && cmd->out < 0;
224 if (need_out) {
225 if (pipe(fdout) < 0) {
226 failed_errno = errno;
227 if (need_in)
228 close_pair(fdin);
229 else if (cmd->in)
230 close(cmd->in);
231 goto fail_pipe;
232 }
233 cmd->out = fdout[0];
234 }
235 need_err = !cmd->no_stderr && cmd->err < 0;
237 if (need_err) {
238 if (pipe(fderr) < 0) {
239 failed_errno = errno;
240 if (need_in)
241 close_pair(fdin);
242 else if (cmd->in)
243 close(cmd->in);
244 if (need_out)
245 close_pair(fdout);
246 else if (cmd->out)
247 close(cmd->out);
248fail_pipe:
249 error("cannot create pipe for %s: %s",
250 cmd->argv[0], strerror(failed_errno));
251 errno = failed_errno;
252 return -1;
253 }
254 cmd->err = fderr[0];
255 }
256 trace_argv_printf(cmd->argv, "trace: run_command:");
258 fflush(NULL);
259#ifndef WIN32
261{
262 int notify_pipe[2];
263 if (pipe(notify_pipe))
264 notify_pipe[0] = notify_pipe[1] = -1;
265 cmd->pid = fork();
267 if (!cmd->pid) {
268 /*
269 * Redirect the channel to write syscall error messages to
270 * before redirecting the process's stderr so that all die()
271 * in subsequent call paths use the parent's stderr.
272 */
273 if (cmd->no_stderr || need_err) {
274 child_err = dup(2);
275 set_cloexec(child_err);
276 }
277 set_die_routine(die_child);
278 set_error_routine(error_child);
279 close(notify_pipe[0]);
281 set_cloexec(notify_pipe[1]);
282 child_notifier = notify_pipe[1];
283 atexit(notify_parent);
284 if (cmd->no_stdin)
286 dup_devnull(0);
287 else if (need_in) {
288 dup2(fdin[0], 0);
289 close_pair(fdin);
290 } else if (cmd->in) {
291 dup2(cmd->in, 0);
292 close(cmd->in);
293 }
294 if (cmd->no_stderr)
296 dup_devnull(2);
297 else if (need_err) {
298 dup2(fderr[1], 2);
299 close_pair(fderr);
300 } else if (cmd->err > 1) {
301 dup2(cmd->err, 2);
302 close(cmd->err);
303 }
304 if (cmd->no_stdout)
306 dup_devnull(1);
307 else if (cmd->stdout_to_stderr)
308 dup2(2, 1);
309 else if (need_out) {
310 dup2(fdout[1], 1);
311 close_pair(fdout);
312 } else if (cmd->out > 1) {
313 dup2(cmd->out, 1);
314 close(cmd->out);
315 }
316 if (cmd->dir && chdir(cmd->dir))
318 die_errno("exec '%s': cd to '%s' failed", cmd->argv[0],
319 cmd->dir);
320 if (cmd->env) {
321 for (; *cmd->env; cmd->env++) {
322 if (strchr(*cmd->env, '='))
323 putenv((char *)*cmd->env);
324 else
325 unsetenv(*cmd->env);
326 }
327 }
328 if (cmd->preexec_cb) {
329 /*
330 * We cannot predict what the pre-exec callback does.
331 * Forgo parent notification.
332 */
333 close(child_notifier);
334 child_notifier = -1;
335 cmd->preexec_cb();
337 }
338 if (cmd->git_cmd) {
339 execv_git_cmd(cmd->argv);
340 } else if (cmd->use_shell) {
341 execv_shell_cmd(cmd->argv);
342 } else {
343 execvp(cmd->argv[0], (char *const*) cmd->argv);
344 }
345 if (errno == ENOENT) {
346 if (!cmd->silent_exec_failure)
347 error("cannot run %s: %s", cmd->argv[0],
348 strerror(ENOENT));
349 exit(127);
350 } else {
351 die_errno("cannot exec '%s'", cmd->argv[0]);
352 }
353 }
354 if (cmd->pid < 0)
355 error("cannot fork() for %s: %s", cmd->argv[0],
356 strerror(failed_errno = errno));
357 else if (cmd->clean_on_exit)
358 mark_child_for_cleanup(cmd->pid);
359 /*
361 * Wait for child's execvp. If the execvp succeeds (or if fork()
362 * failed), EOF is seen immediately by the parent. Otherwise, the
363 * child process sends a single byte.
364 * Note that use of this infrastructure is completely advisory,
365 * therefore, we keep error checks minimal.
366 */
367 close(notify_pipe[1]);
368 if (read(notify_pipe[0], ¬ify_pipe[1], 1) == 1) {
369 /*
370 * At this point we know that fork() succeeded, but execvp()
371 * failed. Errors have been reported to our stderr.
372 */
373 wait_or_whine(cmd->pid, cmd->argv[0],
374 cmd->silent_exec_failure);
375 failed_errno = errno;
376 cmd->pid = -1;
377 }
378 close(notify_pipe[0]);
379}
381#else
382{
383 int fhin = 0, fhout = 1, fherr = 2;
384 const char **sargv = cmd->argv;
385 char **env = environ;
386 if (cmd->no_stdin)
388 fhin = open("/dev/null", O_RDWR);
389 else if (need_in)
390 fhin = dup(fdin[0]);
391 else if (cmd->in)
392 fhin = dup(cmd->in);
393 if (cmd->no_stderr)
395 fherr = open("/dev/null", O_RDWR);
396 else if (need_err)
397 fherr = dup(fderr[1]);
398 else if (cmd->err > 2)
399 fherr = dup(cmd->err);
400 if (cmd->no_stdout)
402 fhout = open("/dev/null", O_RDWR);
403 else if (cmd->stdout_to_stderr)
404 fhout = dup(fherr);
405 else if (need_out)
406 fhout = dup(fdout[1]);
407 else if (cmd->out > 1)
408 fhout = dup(cmd->out);
409 if (cmd->env)
411 env = make_augmented_environ(cmd->env);
412 if (cmd->git_cmd) {
414 cmd->argv = prepare_git_cmd(cmd->argv);
415 } else if (cmd->use_shell) {
416 cmd->argv = prepare_shell_cmd(cmd->argv);
417 }
418 cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, env, cmd->dir,
420 fhin, fhout, fherr);
421 failed_errno = errno;
422 if (cmd->pid < 0 && (!cmd->silent_exec_failure || errno != ENOENT))
423 error("cannot spawn %s: %s", cmd->argv[0], strerror(errno));
424 if (cmd->clean_on_exit && cmd->pid >= 0)
425 mark_child_for_cleanup(cmd->pid);
426 if (cmd->env)
428 free_environ(env);
429 if (cmd->git_cmd)
430 free(cmd->argv);
431 cmd->argv = sargv;
433 if (fhin != 0)
434 close(fhin);
435 if (fhout != 1)
436 close(fhout);
437 if (fherr != 2)
438 close(fherr);
439}
440#endif
441 if (cmd->pid < 0) {
443 if (need_in)
444 close_pair(fdin);
445 else if (cmd->in)
446 close(cmd->in);
447 if (need_out)
448 close_pair(fdout);
449 else if (cmd->out)
450 close(cmd->out);
451 if (need_err)
452 close_pair(fderr);
453 else if (cmd->err)
454 close(cmd->err);
455 errno = failed_errno;
456 return -1;
457 }
458 if (need_in)
460 close(fdin[0]);
461 else if (cmd->in)
462 close(cmd->in);
463 if (need_out)
465 close(fdout[1]);
466 else if (cmd->out)
467 close(cmd->out);
468 if (need_err)
470 close(fderr[1]);
471 else if (cmd->err)
472 close(cmd->err);
473 return 0;
475}
476int finish_command(struct child_process *cmd)
478{
479 return wait_or_whine(cmd->pid, cmd->argv[0], cmd->silent_exec_failure);
480}
481int run_command(struct child_process *cmd)
483{
484 int code = start_command(cmd);
485 if (code)
486 return code;
487 return finish_command(cmd);
488}
489static void prepare_run_command_v_opt(struct child_process *cmd,
491 const char **argv,
492 int opt)
493{
494 memset(cmd, 0, sizeof(*cmd));
495 cmd->argv = argv;
496 cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
497 cmd->git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
498 cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
499 cmd->silent_exec_failure = opt & RUN_SILENT_EXEC_FAILURE ? 1 : 0;
500 cmd->use_shell = opt & RUN_USING_SHELL ? 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}