X-Git-Url: https://git.tokkee.org/?a=blobdiff_plain;f=run-command.c;h=2a1041ef6599c84fff6a8d9faf5dea23a2af3ab0;hb=d577cd216e0adb9cbc726dddd1a0858b4ab4e6e3;hp=0d95340833aa999ecee58ad70c1c61a832fcdf38;hpb=ad336054068074ed614d0bb54bb169e5263499d7;p=git.git diff --git a/run-command.c b/run-command.c index 0d9534083..2a1041ef6 100644 --- a/run-command.c +++ b/run-command.c @@ -8,12 +8,132 @@ static inline void close_pair(int fd[2]) close(fd[1]); } +#ifndef WIN32 static inline void dup_devnull(int to) { int fd = open("/dev/null", O_RDWR); dup2(fd, to); close(fd); } +#endif + +static const char **prepare_shell_cmd(const char **argv) +{ + int argc, nargc = 0; + const char **nargv; + + for (argc = 0; argv[argc]; argc++) + ; /* just counting */ + /* +1 for NULL, +3 for "sh -c" plus extra $0 */ + nargv = xmalloc(sizeof(*nargv) * (argc + 1 + 3)); + + if (argc < 1) + die("BUG: shell command is empty"); + + if (strcspn(argv[0], "|&;<>()$`\\\"' \t\n*?[#~=%") != strlen(argv[0])) { + nargv[nargc++] = "sh"; + nargv[nargc++] = "-c"; + + if (argc < 2) + nargv[nargc++] = argv[0]; + else { + struct strbuf arg0 = STRBUF_INIT; + strbuf_addf(&arg0, "%s \"$@\"", argv[0]); + nargv[nargc++] = strbuf_detach(&arg0, NULL); + } + } + + for (argc = 0; argv[argc]; argc++) + nargv[nargc++] = argv[argc]; + nargv[nargc] = NULL; + + return nargv; +} + +#ifndef WIN32 +static int execv_shell_cmd(const char **argv) +{ + const char **nargv = prepare_shell_cmd(argv); + trace_argv_printf(nargv, "trace: exec:"); + execvp(nargv[0], (char **)nargv); + free(nargv); + return -1; +} +#endif + +#ifndef WIN32 +static int child_err = 2; +static int child_notifier = -1; + +static void notify_parent(void) +{ + ssize_t unused; + unused = write(child_notifier, "", 1); +} + +static NORETURN void die_child(const char *err, va_list params) +{ + char msg[4096]; + ssize_t unused; + int len = vsnprintf(msg, sizeof(msg), err, params); + if (len > sizeof(msg)) + len = sizeof(msg); + + unused = write(child_err, "fatal: ", 7); + unused = write(child_err, msg, len); + unused = write(child_err, "\n", 1); + exit(128); +} +#endif + +static inline void set_cloexec(int fd) +{ + int flags = fcntl(fd, F_GETFD); + if (flags >= 0) + fcntl(fd, F_SETFD, flags | FD_CLOEXEC); +} + +static int wait_or_whine(pid_t pid, const char *argv0, int silent_exec_failure) +{ + int status, code = -1; + pid_t waiting; + int failed_errno = 0; + + while ((waiting = waitpid(pid, &status, 0)) < 0 && errno == EINTR) + ; /* nothing */ + + if (waiting < 0) { + failed_errno = errno; + error("waitpid for %s failed: %s", argv0, strerror(errno)); + } else if (waiting != pid) { + error("waitpid is confused (%s)", argv0); + } else if (WIFSIGNALED(status)) { + code = WTERMSIG(status); + error("%s died of signal %d", argv0, code); + /* + * This return value is chosen so that code & 0xff + * mimics the exit code that a POSIX shell would report for + * a program that died from this signal. + */ + code -= 128; + } else if (WIFEXITED(status)) { + code = WEXITSTATUS(status); + /* + * Convert special exit code when execvp failed. + */ + if (code == 127) { + code = -1; + failed_errno = ENOENT; + if (!silent_exec_failure) + error("cannot run %s: %s", argv0, + strerror(ENOENT)); + } + } else { + error("waitpid is confused (%s)", argv0); + } + errno = failed_errno; + return code; +} int start_command(struct child_process *cmd) { @@ -76,9 +196,30 @@ fail_pipe: trace_argv_printf(cmd->argv, "trace: run_command:"); #ifndef WIN32 +{ + int notify_pipe[2]; + if (pipe(notify_pipe)) + notify_pipe[0] = notify_pipe[1] = -1; + fflush(NULL); cmd->pid = fork(); if (!cmd->pid) { + /* + * Redirect the channel to write syscall error messages to + * before redirecting the process's stderr so that all die() + * in subsequent call paths use the parent's stderr. + */ + if (cmd->no_stderr || need_err) { + child_err = dup(2); + set_cloexec(child_err); + } + set_die_routine(die_child); + + close(notify_pipe[0]); + set_cloexec(notify_pipe[1]); + child_notifier = notify_pipe[1]; + atexit(notify_parent); + if (cmd->no_stdin) dup_devnull(0); else if (need_in) { @@ -122,72 +263,96 @@ fail_pipe: unsetenv(*cmd->env); } } - if (cmd->preexec_cb) + if (cmd->preexec_cb) { + /* + * We cannot predict what the pre-exec callback does. + * Forgo parent notification. + */ + close(child_notifier); + child_notifier = -1; + cmd->preexec_cb(); + } if (cmd->git_cmd) { execv_git_cmd(cmd->argv); + } else if (cmd->use_shell) { + execv_shell_cmd(cmd->argv); } else { execvp(cmd->argv[0], (char *const*) cmd->argv); } - trace_printf("trace: exec '%s' failed: %s\n", cmd->argv[0], - strerror(errno)); - exit(127); + /* + * Do not check for cmd->silent_exec_failure; the parent + * process will check it when it sees this exit code. + */ + if (errno == ENOENT) + exit(127); + else + die_errno("cannot exec '%s'", cmd->argv[0]); } if (cmd->pid < 0) error("cannot fork() for %s: %s", cmd->argv[0], strerror(failed_errno = errno)); + + /* + * Wait for child's execvp. If the execvp succeeds (or if fork() + * failed), EOF is seen immediately by the parent. Otherwise, the + * child process sends a single byte. + * Note that use of this infrastructure is completely advisory, + * therefore, we keep error checks minimal. + */ + close(notify_pipe[1]); + if (read(notify_pipe[0], ¬ify_pipe[1], 1) == 1) { + /* + * At this point we know that fork() succeeded, but execvp() + * failed. Errors have been reported to our stderr. + */ + wait_or_whine(cmd->pid, cmd->argv[0], + cmd->silent_exec_failure); + failed_errno = errno; + cmd->pid = -1; + } + close(notify_pipe[0]); +} #else { - int s0 = -1, s1 = -1, s2 = -1; /* backups of stdin, stdout, stderr */ + int fhin = 0, fhout = 1, fherr = 2; const char **sargv = cmd->argv; char **env = environ; - if (cmd->no_stdin) { - s0 = dup(0); - dup_devnull(0); - } else if (need_in) { - s0 = dup(0); - dup2(fdin[0], 0); - } else if (cmd->in) { - s0 = dup(0); - dup2(cmd->in, 0); - } - - if (cmd->no_stderr) { - s2 = dup(2); - dup_devnull(2); - } else if (need_err) { - s2 = dup(2); - dup2(fderr[1], 2); - } else if (cmd->err > 2) { - s2 = dup(2); - dup2(cmd->err, 2); - } - - if (cmd->no_stdout) { - s1 = dup(1); - dup_devnull(1); - } else if (cmd->stdout_to_stderr) { - s1 = dup(1); - dup2(2, 1); - } else if (need_out) { - s1 = dup(1); - dup2(fdout[1], 1); - } else if (cmd->out > 1) { - s1 = dup(1); - dup2(cmd->out, 1); - } + if (cmd->no_stdin) + fhin = open("/dev/null", O_RDWR); + else if (need_in) + fhin = dup(fdin[0]); + else if (cmd->in) + fhin = dup(cmd->in); + + if (cmd->no_stderr) + fherr = open("/dev/null", O_RDWR); + else if (need_err) + fherr = dup(fderr[1]); + else if (cmd->err > 2) + fherr = dup(cmd->err); + + if (cmd->no_stdout) + fhout = open("/dev/null", O_RDWR); + else if (cmd->stdout_to_stderr) + fhout = dup(fherr); + else if (need_out) + fhout = dup(fdout[1]); + else if (cmd->out > 1) + fhout = dup(cmd->out); - if (cmd->dir) - die("chdir in start_command() not implemented"); if (cmd->env) env = make_augmented_environ(cmd->env); if (cmd->git_cmd) { cmd->argv = prepare_git_cmd(cmd->argv); + } else if (cmd->use_shell) { + cmd->argv = prepare_shell_cmd(cmd->argv); } - cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, env); + cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, env, cmd->dir, + fhin, fhout, fherr); failed_errno = errno; if (cmd->pid < 0 && (!cmd->silent_exec_failure || errno != ENOENT)) error("cannot spawn %s: %s", cmd->argv[0], strerror(errno)); @@ -198,12 +363,12 @@ fail_pipe: free(cmd->argv); cmd->argv = sargv; - if (s0 >= 0) - dup2(s0, 0), close(s0); - if (s1 >= 0) - dup2(s1, 1), close(s1); - if (s2 >= 0) - dup2(s2, 2), close(s2); + if (fhin != 0) + close(fhin); + if (fhout != 1) + close(fhout); + if (fherr != 2) + close(fherr); } #endif @@ -218,6 +383,8 @@ fail_pipe: close(cmd->out); if (need_err) close_pair(fderr); + else if (cmd->err) + close(cmd->err); errno = failed_errno; return -1; } @@ -240,48 +407,6 @@ fail_pipe: return 0; } -static int wait_or_whine(pid_t pid, const char *argv0, int silent_exec_failure) -{ - int status, code = -1; - pid_t waiting; - int failed_errno = 0; - - while ((waiting = waitpid(pid, &status, 0)) < 0 && errno == EINTR) - ; /* nothing */ - - if (waiting < 0) { - failed_errno = errno; - error("waitpid for %s failed: %s", argv0, strerror(errno)); - } else if (waiting != pid) { - error("waitpid is confused (%s)", argv0); - } else if (WIFSIGNALED(status)) { - code = WTERMSIG(status); - error("%s died of signal %d", argv0, code); - /* - * This return value is chosen so that code & 0xff - * mimics the exit code that a POSIX shell would report for - * a program that died from this signal. - */ - code -= 128; - } else if (WIFEXITED(status)) { - code = WEXITSTATUS(status); - /* - * Convert special exit code when execvp failed. - */ - if (code == 127) { - code = -1; - failed_errno = ENOENT; - if (!silent_exec_failure) - error("cannot run %s: %s", argv0, - strerror(ENOENT)); - } - } else { - error("waitpid is confused (%s)", argv0); - } - errno = failed_errno; - return code; -} - int finish_command(struct child_process *cmd) { return wait_or_whine(cmd->pid, cmd->argv[0], cmd->silent_exec_failure); @@ -305,6 +430,7 @@ static void prepare_run_command_v_opt(struct child_process *cmd, cmd->git_cmd = opt & RUN_GIT_CMD ? 1 : 0; cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0; cmd->silent_exec_failure = opt & RUN_SILENT_EXEC_FAILURE ? 1 : 0; + cmd->use_shell = opt & RUN_USING_SHELL ? 1 : 0; } int run_command_v_opt(const char **argv, int opt) @@ -323,11 +449,35 @@ int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const return run_command(&cmd); } -#ifdef WIN32 -static unsigned __stdcall run_thread(void *data) +#ifndef NO_PTHREADS +static pthread_t main_thread; +static int main_thread_set; +static pthread_key_t async_key; + +static void *run_thread(void *data) { struct async *async = data; - return async->proc(async->proc_in, async->proc_out, async->data); + intptr_t ret; + + pthread_setspecific(async_key, async); + ret = async->proc(async->proc_in, async->proc_out, async->data); + return (void *)ret; +} + +static NORETURN void die_async(const char *err, va_list params) +{ + vreportf("fatal: ", err, params); + + if (!pthread_equal(main_thread, pthread_self())) { + struct async *async = pthread_getspecific(async_key); + if (async->proc_in >= 0) + close(async->proc_in); + if (async->proc_out >= 0) + close(async->proc_out); + pthread_exit((void *)128); + } + + exit(128); } #endif @@ -373,7 +523,7 @@ int start_async(struct async *async) else proc_out = -1; -#ifndef WIN32 +#ifdef NO_PTHREADS /* Flush stdio before fork() to avoid cloning buffers */ fflush(NULL); @@ -400,12 +550,29 @@ int start_async(struct async *async) else if (async->out) close(async->out); #else + if (!main_thread_set) { + /* + * We assume that the first time that start_async is called + * it is from the main thread. + */ + main_thread_set = 1; + main_thread = pthread_self(); + pthread_key_create(&async_key, NULL); + set_die_routine(die_async); + } + + if (proc_in >= 0) + set_cloexec(proc_in); + if (proc_out >= 0) + set_cloexec(proc_out); async->proc_in = proc_in; async->proc_out = proc_out; - async->tid = (HANDLE) _beginthreadex(NULL, 0, run_thread, async, 0, NULL); - if (!async->tid) { - error("cannot create thread: %s", strerror(errno)); - goto error; + { + int err = pthread_create(&async->tid, NULL, run_thread, async); + if (err) { + error("cannot create thread: %s", strerror(err)); + goto error; + } } #endif return 0; @@ -425,17 +592,15 @@ error: int finish_async(struct async *async) { -#ifndef WIN32 - int ret = wait_or_whine(async->pid, "child process", 0); +#ifdef NO_PTHREADS + return wait_or_whine(async->pid, "child process", 0); #else - DWORD ret = 0; - if (WaitForSingleObject(async->tid, INFINITE) != WAIT_OBJECT_0) - ret = error("waiting for thread failed: %lu", GetLastError()); - else if (!GetExitCodeThread(async->tid, &ret)) - ret = error("cannot get thread exit code: %lu", GetLastError()); - CloseHandle(async->tid); + void *ret = (void *)(intptr_t)(-1); + + if (pthread_join(async->tid, &ret)) + error("pthread_join failed"); + return (int)(intptr_t)ret; #endif - return ret; } int run_hook(const char *index_file, const char *name, ...)