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Diffstat (limited to 'Utilities/cmlibuv/src/unix/process.c')
-rw-r--r--Utilities/cmlibuv/src/unix/process.c1140
1 files changed, 1140 insertions, 0 deletions
diff --git a/Utilities/cmlibuv/src/unix/process.c b/Utilities/cmlibuv/src/unix/process.c
new file mode 100644
index 0000000000..0de5c4695b
--- /dev/null
+++ b/Utilities/cmlibuv/src/unix/process.c
@@ -0,0 +1,1140 @@
+/* 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 <stdio.h>
+#include <stdlib.h>
+#include <assert.h>
+#include <errno.h>
+#include <signal.h>
+#include <string.h>
+
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <poll.h>
+#include <sched.h>
+
+#if defined(__APPLE__)
+# include <spawn.h>
+# include <paths.h>
+# include <sys/kauth.h>
+# include <sys/types.h>
+# include <sys/sysctl.h>
+# include <dlfcn.h>
+# include <crt_externs.h>
+# include <xlocale.h>
+# 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 <grp.h>
+#endif
+
+#if defined(__MVS__)
+# include "zos-base.h"
+#endif
+
+#ifndef CMAKE_BOOTSTRAP
+#if defined(__linux__)
+# define uv__cpu_set_t cpu_set_t
+#elif defined(__FreeBSD__)
+# include <sys/param.h>
+# include <sys/cpuset.h>
+# include <pthread_np.h>
+# define uv__cpu_set_t cpuset_t
+#endif
+#endif
+
+#if defined(__APPLE__) || \
+ defined(__DragonFly__) || \
+ defined(__FreeBSD__) || \
+ defined(__NetBSD__) || \
+ defined(__OpenBSD__)
+#include <sys/event.h>
+#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;
+#ifndef CMAKE_BOOTSTRAP
+#if defined(__linux__) || defined(__FreeBSD__)
+ int r;
+ int i;
+ int cpumask_size;
+ uv__cpu_set_t cpuset;
+#endif
+#endif
+
+ /* 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);
+
+#ifndef CMAKE_BOOTSTRAP
+#if defined(__linux__) || defined(__FreeBSD__)
+ if (options->cpumask != NULL) {
+ cpumask_size = uv_cpumask_size();
+ assert(options->cpumask_size >= (size_t)cpumask_size);
+
+ CPU_ZERO(&cpuset);
+ for (i = 0; i < cpumask_size; ++i) {
+ if (options->cpumask[i]) {
+ CPU_SET(i, &cpuset);
+ }
+ }
+
+ r = -pthread_setaffinity_np(pthread_self(), sizeof(cpuset), &cpuset);
+ if (r != 0) {
+ uv__write_int(error_fd, r);
+ _exit(127);
+ }
+ }
+#endif
+#endif
+
+ 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__)
+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 should behave
+ * the same, and do not involve PATH resolution at all. The libc
+ * `posix_spawnp` provided by Apple is buggy (since 10.15), so we now emulate it
+ * here, per https://github.com/libuv/libuv/pull/3583. */
+ if (strchr(options->file, '/') != NULL) {
+ do
+ err = posix_spawn(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(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 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 == 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();
+
+ if (*pid == -1)
+ /* Failed to fork */
+ return UV__ERR(errno);
+
+ /* 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__)
+ 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;
+
+ if (options->cpumask != NULL) {
+#ifndef CMAKE_BOOTSTRAP
+#if defined(__linux__) || defined(__FreeBSD__)
+ if (options->cpumask_size < (size_t)uv_cpumask_size()) {
+ return UV_EINVAL;
+ }
+#else
+ return UV_ENOTSUP;
+#endif
+#else
+ return UV_ENOTSUP;
+#endif
+ }
+
+ 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)) {
+#if defined(__MVS__)
+ /* EPERM is returned if the process is a zombie. */
+ siginfo_t infop;
+ if (errno == EPERM &&
+ waitid(P_PID, pid, &infop, WNOHANG | WNOWAIT | WEXITED) == 0)
+ return 0;
+#endif
+ 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);
+}