/* Copyright Joyent, Inc. and other Node contributors. All rights reserved. * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to * deal in the Software without restriction, including without limitation the * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or * sell copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS * IN THE SOFTWARE. */ #include "uv.h" #include "internal.h" #include #include #include #include #include #include #include #include #include #include #include #if defined(__APPLE__) && !TARGET_OS_IPHONE # include # include # include # include # include # include # include # include # define environ (*_NSGetEnviron()) /* macOS 10.14 back does not define this constant */ # ifndef POSIX_SPAWN_SETSID # define POSIX_SPAWN_SETSID 1024 # endif #else extern char **environ; #endif #if defined(__linux__) || defined(__GLIBC__) # include #endif #if defined(__MVS__) # include "zos-base.h" #endif #if defined(__APPLE__) || \ defined(__DragonFly__) || \ defined(__FreeBSD__) || \ defined(__NetBSD__) || \ defined(__OpenBSD__) #include #else #define UV_USE_SIGCHLD #endif #ifdef UV_USE_SIGCHLD static void uv__chld(uv_signal_t* handle, int signum) { assert(signum == SIGCHLD); uv__wait_children(handle->loop); } #endif void uv__wait_children(uv_loop_t* loop) { uv_process_t* process; int exit_status; int term_signal; int status; int options; pid_t pid; QUEUE pending; QUEUE* q; QUEUE* h; QUEUE_INIT(&pending); h = &loop->process_handles; q = QUEUE_HEAD(h); while (q != h) { process = QUEUE_DATA(q, uv_process_t, queue); q = QUEUE_NEXT(q); #ifndef UV_USE_SIGCHLD if ((process->flags & UV_HANDLE_REAP) == 0) continue; options = 0; process->flags &= ~UV_HANDLE_REAP; #else options = WNOHANG; #endif do pid = waitpid(process->pid, &status, options); while (pid == -1 && errno == EINTR); #ifdef UV_USE_SIGCHLD if (pid == 0) /* Not yet exited */ continue; #endif if (pid == -1) { if (errno != ECHILD) abort(); /* The child died, and we missed it. This probably means someone else * stole the waitpid from us. Handle this by not handling it at all. */ continue; } assert(pid == process->pid); process->status = status; QUEUE_REMOVE(&process->queue); QUEUE_INSERT_TAIL(&pending, &process->queue); } h = &pending; q = QUEUE_HEAD(h); while (q != h) { process = QUEUE_DATA(q, uv_process_t, queue); q = QUEUE_NEXT(q); QUEUE_REMOVE(&process->queue); QUEUE_INIT(&process->queue); uv__handle_stop(process); if (process->exit_cb == NULL) continue; exit_status = 0; if (WIFEXITED(process->status)) exit_status = WEXITSTATUS(process->status); term_signal = 0; if (WIFSIGNALED(process->status)) term_signal = WTERMSIG(process->status); process->exit_cb(process, exit_status, term_signal); } assert(QUEUE_EMPTY(&pending)); } /* * Used for initializing stdio streams like options.stdin_stream. Returns * zero on success. See also the cleanup section in uv_spawn(). */ static int uv__process_init_stdio(uv_stdio_container_t* container, int fds[2]) { int mask; int fd; mask = UV_IGNORE | UV_CREATE_PIPE | UV_INHERIT_FD | UV_INHERIT_STREAM; switch (container->flags & mask) { case UV_IGNORE: return 0; case UV_CREATE_PIPE: assert(container->data.stream != NULL); if (container->data.stream->type != UV_NAMED_PIPE) return UV_EINVAL; else return uv_socketpair(SOCK_STREAM, 0, fds, 0, 0); case UV_INHERIT_FD: case UV_INHERIT_STREAM: if (container->flags & UV_INHERIT_FD) fd = container->data.fd; else fd = uv__stream_fd(container->data.stream); if (fd == -1) return UV_EINVAL; fds[1] = fd; return 0; default: assert(0 && "Unexpected flags"); return UV_EINVAL; } } static int uv__process_open_stream(uv_stdio_container_t* container, int pipefds[2]) { int flags; int err; if (!(container->flags & UV_CREATE_PIPE) || pipefds[0] < 0) return 0; err = uv__close(pipefds[1]); if (err != 0) abort(); pipefds[1] = -1; uv__nonblock(pipefds[0], 1); flags = 0; if (container->flags & UV_WRITABLE_PIPE) flags |= UV_HANDLE_READABLE; if (container->flags & UV_READABLE_PIPE) flags |= UV_HANDLE_WRITABLE; return uv__stream_open(container->data.stream, pipefds[0], flags); } static void uv__process_close_stream(uv_stdio_container_t* container) { if (!(container->flags & UV_CREATE_PIPE)) return; uv__stream_close(container->data.stream); } static void uv__write_int(int fd, int val) { ssize_t n; do n = write(fd, &val, sizeof(val)); while (n == -1 && errno == EINTR); /* The write might have failed (e.g. if the parent process has died), * but we have nothing left but to _exit ourself now too. */ _exit(127); } static void uv__write_errno(int error_fd) { uv__write_int(error_fd, UV__ERR(errno)); } #if !(defined(__APPLE__) && (TARGET_OS_TV || TARGET_OS_WATCH)) /* execvp is marked __WATCHOS_PROHIBITED __TVOS_PROHIBITED, so must be * avoided. Since this isn't called on those targets, the function * doesn't even need to be defined for them. */ static void uv__process_child_init(const uv_process_options_t* options, int stdio_count, int (*pipes)[2], int error_fd) { sigset_t signewset; int close_fd; int use_fd; int fd; int n; /* Reset signal disposition first. Use a hard-coded limit because NSIG is not * fixed on Linux: it's either 32, 34 or 64, depending on whether RT signals * are enabled. We are not allowed to touch RT signal handlers, glibc uses * them internally. */ for (n = 1; n < 32; n += 1) { if (n == SIGKILL || n == SIGSTOP) continue; /* Can't be changed. */ #if defined(__HAIKU__) if (n == SIGKILLTHR) continue; /* Can't be changed. */ #endif if (SIG_ERR != signal(n, SIG_DFL)) continue; uv__write_errno(error_fd); } if (options->flags & UV_PROCESS_DETACHED) setsid(); /* First duplicate low numbered fds, since it's not safe to duplicate them, * they could get replaced. Example: swapping stdout and stderr; without * this fd 2 (stderr) would be duplicated into fd 1, thus making both * stdout and stderr go to the same fd, which was not the intention. */ for (fd = 0; fd < stdio_count; fd++) { use_fd = pipes[fd][1]; if (use_fd < 0 || use_fd >= fd) continue; #ifdef F_DUPFD_CLOEXEC /* POSIX 2008 */ pipes[fd][1] = fcntl(use_fd, F_DUPFD_CLOEXEC, stdio_count); #else pipes[fd][1] = fcntl(use_fd, F_DUPFD, stdio_count); #endif if (pipes[fd][1] == -1) uv__write_errno(error_fd); #ifndef F_DUPFD_CLOEXEC /* POSIX 2008 */ n = uv__cloexec(pipes[fd][1], 1); if (n) uv__write_int(error_fd, n); #endif } for (fd = 0; fd < stdio_count; fd++) { close_fd = -1; use_fd = pipes[fd][1]; if (use_fd < 0) { if (fd >= 3) continue; else { /* Redirect stdin, stdout and stderr to /dev/null even if UV_IGNORE is * set. */ uv__close_nocheckstdio(fd); /* Free up fd, if it happens to be open. */ use_fd = open("/dev/null", fd == 0 ? O_RDONLY : O_RDWR); close_fd = use_fd; if (use_fd < 0) uv__write_errno(error_fd); } } if (fd == use_fd) { if (close_fd == -1) { n = uv__cloexec(use_fd, 0); if (n) uv__write_int(error_fd, n); } } else { fd = dup2(use_fd, fd); } if (fd == -1) uv__write_errno(error_fd); if (fd <= 2 && close_fd == -1) uv__nonblock_fcntl(fd, 0); if (close_fd >= stdio_count) uv__close(close_fd); } if (options->cwd != NULL && chdir(options->cwd)) uv__write_errno(error_fd); if (options->flags & (UV_PROCESS_SETUID | UV_PROCESS_SETGID)) { /* When dropping privileges from root, the `setgroups` call will * remove any extraneous groups. If we don't call this, then * even though our uid has dropped, we may still have groups * that enable us to do super-user things. This will fail if we * aren't root, so don't bother checking the return value, this * is just done as an optimistic privilege dropping function. */ SAVE_ERRNO(setgroups(0, NULL)); } if ((options->flags & UV_PROCESS_SETGID) && setgid(options->gid)) uv__write_errno(error_fd); if ((options->flags & UV_PROCESS_SETUID) && setuid(options->uid)) uv__write_errno(error_fd); if (options->env != NULL) environ = options->env; /* Reset signal mask just before exec. */ sigemptyset(&signewset); if (sigprocmask(SIG_SETMASK, &signewset, NULL) != 0) abort(); #ifdef __MVS__ execvpe(options->file, options->args, environ); #else execvp(options->file, options->args); #endif uv__write_errno(error_fd); } #endif #if defined(__APPLE__) && !TARGET_OS_IPHONE typedef struct uv__posix_spawn_fncs_tag { struct { int (*addchdir_np)(const posix_spawn_file_actions_t *, const char *); } file_actions; } uv__posix_spawn_fncs_t; static uv_once_t posix_spawn_init_once = UV_ONCE_INIT; static uv__posix_spawn_fncs_t posix_spawn_fncs; static int posix_spawn_can_use_setsid; static void uv__spawn_init_posix_spawn_fncs(void) { /* Try to locate all non-portable functions at runtime */ posix_spawn_fncs.file_actions.addchdir_np = dlsym(RTLD_DEFAULT, "posix_spawn_file_actions_addchdir_np"); } static void uv__spawn_init_can_use_setsid(void) { int which[] = {CTL_KERN, KERN_OSRELEASE}; unsigned major; unsigned minor; unsigned patch; char buf[256]; size_t len; len = sizeof(buf); if (sysctl(which, ARRAY_SIZE(which), buf, &len, NULL, 0)) return; /* NULL specifies to use LC_C_LOCALE */ if (3 != sscanf_l(buf, NULL, "%u.%u.%u", &major, &minor, &patch)) return; posix_spawn_can_use_setsid = (major >= 19); /* macOS Catalina */ } static void uv__spawn_init_posix_spawn(void) { /* Init handles to all potentially non-defined functions */ uv__spawn_init_posix_spawn_fncs(); /* Init feature detection for POSIX_SPAWN_SETSID flag */ uv__spawn_init_can_use_setsid(); } static int uv__spawn_set_posix_spawn_attrs( posix_spawnattr_t* attrs, const uv__posix_spawn_fncs_t* posix_spawn_fncs, const uv_process_options_t* options) { int err; unsigned int flags; sigset_t signal_set; err = posix_spawnattr_init(attrs); if (err != 0) { /* If initialization fails, no need to de-init, just return */ return err; } if (options->flags & (UV_PROCESS_SETUID | UV_PROCESS_SETGID)) { /* kauth_cred_issuser currently requires exactly uid == 0 for these * posixspawn_attrs (set_groups_np, setuid_np, setgid_np), which deviates * from the normal specification of setuid (which also uses euid), and they * are also undocumented syscalls, so we do not use them. */ err = ENOSYS; goto error; } /* Set flags for spawn behavior * 1) POSIX_SPAWN_CLOEXEC_DEFAULT: (Apple Extension) All descriptors in the * parent will be treated as if they had been created with O_CLOEXEC. The * only fds that will be passed on to the child are those manipulated by * the file actions * 2) POSIX_SPAWN_SETSIGDEF: Signals mentioned in spawn-sigdefault in the * spawn attributes will be reset to behave as their default * 3) POSIX_SPAWN_SETSIGMASK: Signal mask will be set to the value of * spawn-sigmask in attributes * 4) POSIX_SPAWN_SETSID: Make the process a new session leader if a detached * session was requested. */ flags = POSIX_SPAWN_CLOEXEC_DEFAULT | POSIX_SPAWN_SETSIGDEF | POSIX_SPAWN_SETSIGMASK; if (options->flags & UV_PROCESS_DETACHED) { /* If running on a version of macOS where this flag is not supported, * revert back to the fork/exec flow. Otherwise posix_spawn will * silently ignore the flag. */ if (!posix_spawn_can_use_setsid) { err = ENOSYS; goto error; } flags |= POSIX_SPAWN_SETSID; } err = posix_spawnattr_setflags(attrs, flags); if (err != 0) goto error; /* Reset all signal the child to their default behavior */ sigfillset(&signal_set); err = posix_spawnattr_setsigdefault(attrs, &signal_set); if (err != 0) goto error; /* Reset the signal mask for all signals */ sigemptyset(&signal_set); err = posix_spawnattr_setsigmask(attrs, &signal_set); if (err != 0) goto error; return err; error: (void) posix_spawnattr_destroy(attrs); return err; } static int uv__spawn_set_posix_spawn_file_actions( posix_spawn_file_actions_t* actions, const uv__posix_spawn_fncs_t* posix_spawn_fncs, const uv_process_options_t* options, int stdio_count, int (*pipes)[2]) { int fd; int fd2; int use_fd; int err; err = posix_spawn_file_actions_init(actions); if (err != 0) { /* If initialization fails, no need to de-init, just return */ return err; } /* Set the current working directory if requested */ if (options->cwd != NULL) { if (posix_spawn_fncs->file_actions.addchdir_np == NULL) { err = ENOSYS; goto error; } err = posix_spawn_fncs->file_actions.addchdir_np(actions, options->cwd); if (err != 0) goto error; } /* Do not return ENOSYS after this point, as we may mutate pipes. */ /* First duplicate low numbered fds, since it's not safe to duplicate them, * they could get replaced. Example: swapping stdout and stderr; without * this fd 2 (stderr) would be duplicated into fd 1, thus making both * stdout and stderr go to the same fd, which was not the intention. */ for (fd = 0; fd < stdio_count; fd++) { use_fd = pipes[fd][1]; if (use_fd < 0 || use_fd >= fd) continue; use_fd = stdio_count; for (fd2 = 0; fd2 < stdio_count; fd2++) { /* If we were not setting POSIX_SPAWN_CLOEXEC_DEFAULT, we would need to * also consider whether fcntl(fd, F_GETFD) returned without the * FD_CLOEXEC flag set. */ if (pipes[fd2][1] == use_fd) { use_fd++; fd2 = 0; } } err = posix_spawn_file_actions_adddup2( actions, pipes[fd][1], use_fd); assert(err != ENOSYS); if (err != 0) goto error; pipes[fd][1] = use_fd; } /* Second, move the descriptors into their respective places */ for (fd = 0; fd < stdio_count; fd++) { use_fd = pipes[fd][1]; if (use_fd < 0) { if (fd >= 3) continue; else { /* If ignored, redirect to (or from) /dev/null, */ err = posix_spawn_file_actions_addopen( actions, fd, "/dev/null", fd == 0 ? O_RDONLY : O_RDWR, 0); assert(err != ENOSYS); if (err != 0) goto error; continue; } } if (fd == use_fd) err = posix_spawn_file_actions_addinherit_np(actions, fd); else err = posix_spawn_file_actions_adddup2(actions, use_fd, fd); assert(err != ENOSYS); if (err != 0) goto error; /* Make sure the fd is marked as non-blocking (state shared between child * and parent). */ uv__nonblock_fcntl(use_fd, 0); } /* Finally, close all the superfluous descriptors */ for (fd = 0; fd < stdio_count; fd++) { use_fd = pipes[fd][1]; if (use_fd < stdio_count) continue; /* Check if we already closed this. */ for (fd2 = 0; fd2 < fd; fd2++) { if (pipes[fd2][1] == use_fd) break; } if (fd2 < fd) continue; err = posix_spawn_file_actions_addclose(actions, use_fd); assert(err != ENOSYS); if (err != 0) goto error; } return 0; error: (void) posix_spawn_file_actions_destroy(actions); return err; } char* uv__spawn_find_path_in_env(char** env) { char** env_iterator; const char path_var[] = "PATH="; /* Look for an environment variable called PATH in the * provided env array, and return its value if found */ for (env_iterator = env; *env_iterator != NULL; env_iterator++) { if (strncmp(*env_iterator, path_var, sizeof(path_var) - 1) == 0) { /* Found "PATH=" at the beginning of the string */ return *env_iterator + sizeof(path_var) - 1; } } return NULL; } static int uv__spawn_resolve_and_spawn(const uv_process_options_t* options, posix_spawnattr_t* attrs, posix_spawn_file_actions_t* actions, pid_t* pid) { const char *p; const char *z; const char *path; size_t l; size_t k; int err; int seen_eacces; path = NULL; err = -1; seen_eacces = 0; /* Short circuit for erroneous case */ if (options->file == NULL) return ENOENT; /* The environment for the child process is that of the parent unless overriden * by options->env */ char** env = environ; if (options->env != NULL) env = options->env; /* If options->file contains a slash, posix_spawn/posix_spawnp behave * the same, and don't involve PATH resolution at all. Otherwise, if * options->file does not include a slash, but no custom environment is * to be used, the environment used for path resolution as well for the * child process is that of the parent process, so posix_spawnp is the * way to go. */ if (strchr(options->file, '/') != NULL || options->env == NULL) { do err = posix_spawnp(pid, options->file, actions, attrs, options->args, env); while (err == EINTR); return err; } /* Look for the definition of PATH in the provided env */ path = uv__spawn_find_path_in_env(options->env); /* The following resolution logic (execvpe emulation) is copied from * https://git.musl-libc.org/cgit/musl/tree/src/process/execvp.c * and adapted to work for our specific usage */ /* If no path was provided in options->env, use the default value * to look for the executable */ if (path == NULL) path = _PATH_DEFPATH; k = strnlen(options->file, NAME_MAX + 1); if (k > NAME_MAX) return ENAMETOOLONG; l = strnlen(path, PATH_MAX - 1) + 1; for (p = path;; p = z) { /* Compose the new process file from the entry in the PATH * environment variable and the actual file name */ char b[PATH_MAX + NAME_MAX]; z = strchr(p, ':'); if (!z) z = p + strlen(p); if ((size_t)(z - p) >= l) { if (!*z++) break; continue; } memcpy(b, p, z - p); b[z - p] = '/'; memcpy(b + (z - p) + (z > p), options->file, k + 1); /* Try to spawn the new process file. If it fails with ENOENT, the * new process file is not in this PATH entry, continue with the next * PATH entry. */ do err = posix_spawn(pid, b, actions, attrs, options->args, env); while (err == EINTR); switch (err) { case EACCES: seen_eacces = 1; break; /* continue search */ case ENOENT: case ENOTDIR: break; /* continue search */ default: return err; } if (!*z++) break; } if (seen_eacces) return EACCES; return err; } static int uv__spawn_and_init_child_posix_spawn( const uv_process_options_t* options, int stdio_count, int (*pipes)[2], pid_t* pid, const uv__posix_spawn_fncs_t* posix_spawn_fncs) { int err; posix_spawnattr_t attrs; posix_spawn_file_actions_t actions; err = uv__spawn_set_posix_spawn_attrs(&attrs, posix_spawn_fncs, options); if (err != 0) goto error; /* This may mutate pipes. */ err = uv__spawn_set_posix_spawn_file_actions(&actions, posix_spawn_fncs, options, stdio_count, pipes); if (err != 0) { (void) posix_spawnattr_destroy(&attrs); goto error; } /* Try to spawn options->file resolving in the provided environment * if any */ err = uv__spawn_resolve_and_spawn(options, &attrs, &actions, pid); assert(err != ENOSYS); /* Destroy the actions/attributes */ (void) posix_spawn_file_actions_destroy(&actions); (void) posix_spawnattr_destroy(&attrs); error: /* In an error situation, the attributes and file actions are * already destroyed, only the happy path requires cleanup */ return UV__ERR(err); } #endif static int uv__spawn_and_init_child_fork(const uv_process_options_t* options, int stdio_count, int (*pipes)[2], int error_fd, pid_t* pid) { sigset_t signewset; sigset_t sigoldset; /* Start the child with most signals blocked, to avoid any issues before we * can reset them, but allow program failures to exit (and not hang). */ sigfillset(&signewset); sigdelset(&signewset, SIGKILL); sigdelset(&signewset, SIGSTOP); sigdelset(&signewset, SIGTRAP); sigdelset(&signewset, SIGSEGV); sigdelset(&signewset, SIGBUS); sigdelset(&signewset, SIGILL); sigdelset(&signewset, SIGSYS); sigdelset(&signewset, SIGABRT); if (pthread_sigmask(SIG_BLOCK, &signewset, &sigoldset) != 0) abort(); *pid = fork(); if (*pid == -1) { /* Failed to fork */ return UV__ERR(errno); } if (*pid == 0) { /* Fork succeeded, in the child process */ uv__process_child_init(options, stdio_count, pipes, error_fd); abort(); } if (pthread_sigmask(SIG_SETMASK, &sigoldset, NULL) != 0) abort(); /* Fork succeeded, in the parent process */ return 0; } static int uv__spawn_and_init_child( uv_loop_t* loop, const uv_process_options_t* options, int stdio_count, int (*pipes)[2], pid_t* pid) { int signal_pipe[2] = { -1, -1 }; int status; int err; int exec_errorno; ssize_t r; #if defined(__APPLE__) && !TARGET_OS_IPHONE uv_once(&posix_spawn_init_once, uv__spawn_init_posix_spawn); /* Special child process spawn case for macOS Big Sur (11.0) onwards * * Big Sur introduced a significant performance degradation on a call to * fork/exec when the process has many pages mmaped in with MAP_JIT, like, say * a javascript interpreter. Electron-based applications, for example, * are impacted; though the magnitude of the impact depends on how much the * app relies on subprocesses. * * On macOS, though, posix_spawn is implemented in a way that does not * exhibit the problem. This block implements the forking and preparation * logic with posix_spawn and its related primitives. It also takes advantage of * the macOS extension POSIX_SPAWN_CLOEXEC_DEFAULT that makes impossible to * leak descriptors to the child process. */ err = uv__spawn_and_init_child_posix_spawn(options, stdio_count, pipes, pid, &posix_spawn_fncs); /* The posix_spawn flow will return UV_ENOSYS if any of the posix_spawn_x_np * non-standard functions is both _needed_ and _undefined_. In those cases, * default back to the fork/execve strategy. For all other errors, just fail. */ if (err != UV_ENOSYS) return err; #endif /* This pipe is used by the parent to wait until * the child has called `execve()`. We need this * to avoid the following race condition: * * if ((pid = fork()) > 0) { * kill(pid, SIGTERM); * } * else if (pid == 0) { * execve("/bin/cat", argp, envp); * } * * The parent sends a signal immediately after forking. * Since the child may not have called `execve()` yet, * there is no telling what process receives the signal, * our fork or /bin/cat. * * To avoid ambiguity, we create a pipe with both ends * marked close-on-exec. Then, after the call to `fork()`, * the parent polls the read end until it EOFs or errors with EPIPE. */ err = uv__make_pipe(signal_pipe, 0); if (err) return err; /* Acquire write lock to prevent opening new fds in worker threads */ uv_rwlock_wrlock(&loop->cloexec_lock); err = uv__spawn_and_init_child_fork(options, stdio_count, pipes, signal_pipe[1], pid); /* Release lock in parent process */ uv_rwlock_wrunlock(&loop->cloexec_lock); uv__close(signal_pipe[1]); if (err == 0) { do r = read(signal_pipe[0], &exec_errorno, sizeof(exec_errorno)); while (r == -1 && errno == EINTR); if (r == 0) ; /* okay, EOF */ else if (r == sizeof(exec_errorno)) { do err = waitpid(*pid, &status, 0); /* okay, read errorno */ while (err == -1 && errno == EINTR); assert(err == *pid); err = exec_errorno; } else if (r == -1 && errno == EPIPE) { /* Something unknown happened to our child before spawn */ do err = waitpid(*pid, &status, 0); /* okay, got EPIPE */ while (err == -1 && errno == EINTR); assert(err == *pid); err = UV_EPIPE; } else abort(); } uv__close_nocheckstdio(signal_pipe[0]); return err; } int uv_spawn(uv_loop_t* loop, uv_process_t* process, const uv_process_options_t* options) { #if defined(__APPLE__) && (TARGET_OS_TV || TARGET_OS_WATCH) /* fork is marked __WATCHOS_PROHIBITED __TVOS_PROHIBITED. */ return UV_ENOSYS; #else int pipes_storage[8][2]; int (*pipes)[2]; int stdio_count; pid_t pid; int err; int exec_errorno; int i; assert(options->file != NULL); assert(!(options->flags & ~(UV_PROCESS_DETACHED | UV_PROCESS_SETGID | UV_PROCESS_SETUID | UV_PROCESS_WINDOWS_HIDE | UV_PROCESS_WINDOWS_HIDE_CONSOLE | UV_PROCESS_WINDOWS_HIDE_GUI | UV_PROCESS_WINDOWS_VERBATIM_ARGUMENTS))); uv__handle_init(loop, (uv_handle_t*)process, UV_PROCESS); QUEUE_INIT(&process->queue); process->status = 0; stdio_count = options->stdio_count; if (stdio_count < 3) stdio_count = 3; err = UV_ENOMEM; pipes = pipes_storage; if (stdio_count > (int) ARRAY_SIZE(pipes_storage)) pipes = uv__malloc(stdio_count * sizeof(*pipes)); if (pipes == NULL) goto error; for (i = 0; i < stdio_count; i++) { pipes[i][0] = -1; pipes[i][1] = -1; } for (i = 0; i < options->stdio_count; i++) { err = uv__process_init_stdio(options->stdio + i, pipes[i]); if (err) goto error; } #ifdef UV_USE_SIGCHLD uv_signal_start(&loop->child_watcher, uv__chld, SIGCHLD); #endif /* Spawn the child */ exec_errorno = uv__spawn_and_init_child(loop, options, stdio_count, pipes, &pid); #if 0 /* This runs into a nodejs issue (it expects initialized streams, even if the * exec failed). * See https://github.com/libuv/libuv/pull/3107#issuecomment-782482608 */ if (exec_errorno != 0) goto error; #endif /* Activate this handle if exec() happened successfully, even if we later * fail to open a stdio handle. This ensures we can eventually reap the child * with waitpid. */ if (exec_errorno == 0) { #ifndef UV_USE_SIGCHLD struct kevent event; EV_SET(&event, pid, EVFILT_PROC, EV_ADD | EV_ONESHOT, NOTE_EXIT, 0, 0); if (kevent(loop->backend_fd, &event, 1, NULL, 0, NULL)) { if (errno != ESRCH) abort(); /* Process already exited. Call waitpid on the next loop iteration. */ process->flags |= UV_HANDLE_REAP; loop->flags |= UV_LOOP_REAP_CHILDREN; } #endif process->pid = pid; process->exit_cb = options->exit_cb; QUEUE_INSERT_TAIL(&loop->process_handles, &process->queue); uv__handle_start(process); } for (i = 0; i < options->stdio_count; i++) { err = uv__process_open_stream(options->stdio + i, pipes[i]); if (err == 0) continue; while (i--) uv__process_close_stream(options->stdio + i); goto error; } if (pipes != pipes_storage) uv__free(pipes); return exec_errorno; error: if (pipes != NULL) { for (i = 0; i < stdio_count; i++) { if (i < options->stdio_count) if (options->stdio[i].flags & (UV_INHERIT_FD | UV_INHERIT_STREAM)) continue; if (pipes[i][0] != -1) uv__close_nocheckstdio(pipes[i][0]); if (pipes[i][1] != -1) uv__close_nocheckstdio(pipes[i][1]); } if (pipes != pipes_storage) uv__free(pipes); } return err; #endif } int uv_process_kill(uv_process_t* process, int signum) { return uv_kill(process->pid, signum); } int uv_kill(int pid, int signum) { if (kill(pid, signum)) return UV__ERR(errno); else return 0; } void uv__process_close(uv_process_t* handle) { QUEUE_REMOVE(&handle->queue); uv__handle_stop(handle); if (QUEUE_EMPTY(&handle->loop->process_handles)) uv_signal_stop(&handle->loop->child_watcher); }