forked from cory/tildefriends
libuv 1.44.0
git-svn-id: https://www.unprompted.com/svn/projects/tildefriends/trunk@3856 ed5197a5-7fde-0310-b194-c3ffbd925b24
This commit is contained in:
753
deps/libuv/src/unix/process.c
vendored
753
deps/libuv/src/unix/process.c
vendored
@ -27,6 +27,7 @@
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#include <assert.h>
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#include <errno.h>
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#include <signal.h>
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#include <string.h>
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#include <sys/types.h>
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#include <sys/wait.h>
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@ -35,8 +36,21 @@
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#include <poll.h>
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#if defined(__APPLE__) && !TARGET_OS_IPHONE
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# include <spawn.h>
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# include <paths.h>
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# include <sys/kauth.h>
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# include <sys/types.h>
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# include <sys/sysctl.h>
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# include <dlfcn.h>
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# include <crt_externs.h>
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# include <xlocale.h>
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# define environ (*_NSGetEnviron())
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/* macOS 10.14 back does not define this constant */
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# ifndef POSIX_SPAWN_SETSID
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# define POSIX_SPAWN_SETSID 1024
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# endif
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#else
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extern char **environ;
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#endif
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@ -49,10 +63,20 @@ extern char **environ;
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# include "zos-base.h"
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#endif
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#if defined(__APPLE__) || defined(__DragonFly__) || defined(__FreeBSD__) || defined(__NetBSD__)
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#include <sys/event.h>
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#endif
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#if !(defined(__APPLE__) || defined(__DragonFly__) || defined(__FreeBSD__) || defined(__NetBSD__))
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static void uv__chld(uv_signal_t* handle, int signum) {
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assert(signum == SIGCHLD);
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uv__wait_children(handle->loop);
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}
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#endif
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void uv__wait_children(uv_loop_t* loop) {
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uv_process_t* process;
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uv_loop_t* loop;
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int exit_status;
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int term_signal;
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int status;
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@ -61,10 +85,7 @@ static void uv__chld(uv_signal_t* handle, int signum) {
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QUEUE* q;
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QUEUE* h;
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assert(signum == SIGCHLD);
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QUEUE_INIT(&pending);
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loop = handle->loop;
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h = &loop->process_handles;
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q = QUEUE_HEAD(h);
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@ -254,22 +275,33 @@ static void uv__process_child_init(const uv_process_options_t* options,
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use_fd = pipes[fd][1];
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if (use_fd < 0 || use_fd >= fd)
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continue;
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#ifdef F_DUPFD_CLOEXEC /* POSIX 2008 */
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pipes[fd][1] = fcntl(use_fd, F_DUPFD_CLOEXEC, stdio_count);
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#else
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pipes[fd][1] = fcntl(use_fd, F_DUPFD, stdio_count);
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#endif
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if (pipes[fd][1] == -1)
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uv__write_errno(error_fd);
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#ifndef F_DUPFD_CLOEXEC /* POSIX 2008 */
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n = uv__cloexec(pipes[fd][1], 1);
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if (n) {
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uv__write_int(error_fd, n);
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_exit(127);
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}
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#endif
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}
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for (fd = 0; fd < stdio_count; fd++) {
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close_fd = pipes[fd][0];
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close_fd = -1;
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use_fd = pipes[fd][1];
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if (use_fd < 0) {
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if (fd >= 3)
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continue;
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else {
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/* redirect stdin, stdout and stderr to /dev/null even if UV_IGNORE is
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* set
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*/
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/* Redirect stdin, stdout and stderr to /dev/null even if UV_IGNORE is
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* set. */
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uv__close_nocheckstdio(fd); /* Free up fd, if it happens to be open. */
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use_fd = open("/dev/null", fd == 0 ? O_RDONLY : O_RDWR);
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close_fd = use_fd;
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@ -278,28 +310,29 @@ static void uv__process_child_init(const uv_process_options_t* options,
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}
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}
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if (fd == use_fd)
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uv__cloexec_fcntl(use_fd, 0);
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else
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if (fd == use_fd) {
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if (close_fd == -1) {
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n = uv__cloexec(use_fd, 0);
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if (n) {
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uv__write_int(error_fd, n);
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_exit(127);
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}
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}
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}
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else {
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fd = dup2(use_fd, fd);
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}
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if (fd == -1)
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uv__write_errno(error_fd);
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if (fd <= 2)
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if (fd <= 2 && close_fd == -1)
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uv__nonblock_fcntl(fd, 0);
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if (close_fd >= stdio_count)
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uv__close(close_fd);
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}
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for (fd = 0; fd < stdio_count; fd++) {
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use_fd = pipes[fd][1];
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if (use_fd >= stdio_count)
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uv__close(use_fd);
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}
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if (options->cwd != NULL && chdir(options->cwd))
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uv__write_errno(error_fd);
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@ -320,9 +353,8 @@ static void uv__process_child_init(const uv_process_options_t* options,
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if ((options->flags & UV_PROCESS_SETUID) && setuid(options->uid))
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uv__write_errno(error_fd);
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if (options->env != NULL) {
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if (options->env != NULL)
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environ = options->env;
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}
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/* Reset signal mask just before exec. */
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sigemptyset(&signewset);
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@ -341,6 +373,562 @@ static void uv__process_child_init(const uv_process_options_t* options,
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#endif
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#if defined(__APPLE__)
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typedef struct uv__posix_spawn_fncs_tag {
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struct {
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int (*addchdir_np)(const posix_spawn_file_actions_t *, const char *);
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} file_actions;
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} uv__posix_spawn_fncs_t;
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static uv_once_t posix_spawn_init_once = UV_ONCE_INIT;
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static uv__posix_spawn_fncs_t posix_spawn_fncs;
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static int posix_spawn_can_use_setsid;
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static void uv__spawn_init_posix_spawn_fncs(void) {
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/* Try to locate all non-portable functions at runtime */
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posix_spawn_fncs.file_actions.addchdir_np =
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dlsym(RTLD_DEFAULT, "posix_spawn_file_actions_addchdir_np");
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}
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static void uv__spawn_init_can_use_setsid(void) {
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static const int MACOS_CATALINA_VERSION_MAJOR = 19;
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char version_str[256];
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char* version_major_str;
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size_t version_str_size = 256;
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int r;
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int version_major;
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/* Get a version string */
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r = sysctlbyname("kern.osrelease", version_str, &version_str_size, NULL, 0);
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if (r != 0)
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return;
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/* Try to get the major version number. If not found
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* fall back to the fork/exec flow */
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version_major_str = strtok(version_str, ".");
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if (version_major_str == NULL)
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return;
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/* Parse the version major as a number. If it is greater than
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* the major version for macOS Catalina (aka macOS 10.15), then
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* the POSIX_SPAWN_SETSID flag is available */
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version_major = atoi_l(version_major_str, NULL); /* Use LC_C_LOCALE */
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if (version_major >= MACOS_CATALINA_VERSION_MAJOR)
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posix_spawn_can_use_setsid = 1;
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}
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static void uv__spawn_init_posix_spawn(void) {
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/* Init handles to all potentially non-defined functions */
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uv__spawn_init_posix_spawn_fncs();
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/* Init feature detection for POSIX_SPAWN_SETSID flag */
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uv__spawn_init_can_use_setsid();
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}
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static int uv__spawn_set_posix_spawn_attrs(
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posix_spawnattr_t* attrs,
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const uv__posix_spawn_fncs_t* posix_spawn_fncs,
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const uv_process_options_t* options) {
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int err;
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unsigned int flags;
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sigset_t signal_set;
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err = posix_spawnattr_init(attrs);
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if (err != 0) {
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/* If initialization fails, no need to de-init, just return */
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return err;
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}
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if (options->flags & (UV_PROCESS_SETUID | UV_PROCESS_SETGID)) {
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/* kauth_cred_issuser currently requires exactly uid == 0 for these
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* posixspawn_attrs (set_groups_np, setuid_np, setgid_np), which deviates
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* from the normal specification of setuid (which also uses euid), and they
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* are also undocumented syscalls, so we do not use them. */
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err = ENOSYS;
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goto error;
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}
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/* Set flags for spawn behavior
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* 1) POSIX_SPAWN_CLOEXEC_DEFAULT: (Apple Extension) All descriptors in the
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* parent will be treated as if they had been created with O_CLOEXEC. The
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* only fds that will be passed on to the child are those manipulated by
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* the file actions
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* 2) POSIX_SPAWN_SETSIGDEF: Signals mentioned in spawn-sigdefault in the
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* spawn attributes will be reset to behave as their default
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* 3) POSIX_SPAWN_SETSIGMASK: Signal mask will be set to the value of
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* spawn-sigmask in attributes
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* 4) POSIX_SPAWN_SETSID: Make the process a new session leader if a detached
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* session was requested. */
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flags = POSIX_SPAWN_CLOEXEC_DEFAULT |
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POSIX_SPAWN_SETSIGDEF |
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POSIX_SPAWN_SETSIGMASK;
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if (options->flags & UV_PROCESS_DETACHED) {
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/* If running on a version of macOS where this flag is not supported,
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* revert back to the fork/exec flow. Otherwise posix_spawn will
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* silently ignore the flag. */
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if (!posix_spawn_can_use_setsid) {
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err = ENOSYS;
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goto error;
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}
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flags |= POSIX_SPAWN_SETSID;
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}
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err = posix_spawnattr_setflags(attrs, flags);
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if (err != 0)
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goto error;
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/* Reset all signal the child to their default behavior */
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sigfillset(&signal_set);
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err = posix_spawnattr_setsigdefault(attrs, &signal_set);
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if (err != 0)
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goto error;
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||||
/* Reset the signal mask for all signals */
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sigemptyset(&signal_set);
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err = posix_spawnattr_setsigmask(attrs, &signal_set);
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||||
if (err != 0)
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goto error;
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||||
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||||
return err;
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||||
error:
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(void) posix_spawnattr_destroy(attrs);
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return err;
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}
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||||
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||||
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||||
static int uv__spawn_set_posix_spawn_file_actions(
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||||
posix_spawn_file_actions_t* actions,
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||||
const uv__posix_spawn_fncs_t* posix_spawn_fncs,
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||||
const uv_process_options_t* options,
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||||
int stdio_count,
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||||
int (*pipes)[2]) {
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||||
int fd;
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||||
int fd2;
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||||
int use_fd;
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||||
int err;
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||||
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||||
err = posix_spawn_file_actions_init(actions);
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||||
if (err != 0) {
|
||||
/* If initialization fails, no need to de-init, just return */
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||||
return err;
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||||
}
|
||||
|
||||
/* Set the current working directory if requested */
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||||
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__)
|
||||
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) {
|
||||
@ -348,18 +936,13 @@ int uv_spawn(uv_loop_t* loop,
|
||||
/* fork is marked __WATCHOS_PROHIBITED __TVOS_PROHIBITED. */
|
||||
return UV_ENOSYS;
|
||||
#else
|
||||
sigset_t signewset;
|
||||
sigset_t sigoldset;
|
||||
int signal_pipe[2] = { -1, -1 };
|
||||
int pipes_storage[8][2];
|
||||
int (*pipes)[2];
|
||||
int stdio_count;
|
||||
ssize_t r;
|
||||
pid_t pid;
|
||||
int err;
|
||||
int exec_errorno;
|
||||
int i;
|
||||
int status;
|
||||
|
||||
assert(options->file != NULL);
|
||||
assert(!(options->flags & ~(UV_PROCESS_DETACHED |
|
||||
@ -372,6 +955,7 @@ int uv_spawn(uv_loop_t* loop,
|
||||
|
||||
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)
|
||||
@ -396,92 +980,42 @@ int uv_spawn(uv_loop_t* loop,
|
||||
goto error;
|
||||
}
|
||||
|
||||
/* 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)
|
||||
goto error;
|
||||
|
||||
#if !(defined(__APPLE__) || defined(__DragonFly__) || defined(__FreeBSD__) || defined(__NetBSD__))
|
||||
uv_signal_start(&loop->child_watcher, uv__chld, SIGCHLD);
|
||||
#endif
|
||||
|
||||
/* Acquire write lock to prevent opening new fds in worker threads */
|
||||
uv_rwlock_wrlock(&loop->cloexec_lock);
|
||||
/* Spawn the child */
|
||||
exec_errorno = uv__spawn_and_init_child(loop, options, stdio_count, pipes, &pid);
|
||||
|
||||
/* 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();
|
||||
#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
|
||||
|
||||
pid = fork();
|
||||
if (pid == -1)
|
||||
err = UV__ERR(errno);
|
||||
/* 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) {
|
||||
#if defined(__APPLE__) || defined(__DragonFly__) || defined(__FreeBSD__) || defined(__NetBSD__)
|
||||
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. */
|
||||
loop->flags |= UV_LOOP_REAP_CHILDREN;
|
||||
}
|
||||
#endif
|
||||
|
||||
if (pid == 0)
|
||||
uv__process_child_init(options, stdio_count, pipes, signal_pipe[1]);
|
||||
|
||||
if (pthread_sigmask(SIG_SETMASK, &sigoldset, NULL) != 0)
|
||||
abort();
|
||||
|
||||
/* Release lock in parent process */
|
||||
uv_rwlock_wrunlock(&loop->cloexec_lock);
|
||||
|
||||
uv__close(signal_pipe[1]);
|
||||
|
||||
if (pid == -1) {
|
||||
uv__close(signal_pipe[0]);
|
||||
goto error;
|
||||
process->pid = pid;
|
||||
process->exit_cb = options->exit_cb;
|
||||
QUEUE_INSERT_TAIL(&loop->process_handles, &process->queue);
|
||||
uv__handle_start(process);
|
||||
}
|
||||
|
||||
process->status = 0;
|
||||
exec_errorno = 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);
|
||||
} else if (r == -1 && errno == EPIPE) {
|
||||
do
|
||||
err = waitpid(pid, &status, 0); /* okay, got EPIPE */
|
||||
while (err == -1 && errno == EINTR);
|
||||
assert(err == pid);
|
||||
} else
|
||||
abort();
|
||||
|
||||
uv__close_nocheckstdio(signal_pipe[0]);
|
||||
|
||||
for (i = 0; i < options->stdio_count; i++) {
|
||||
err = uv__process_open_stream(options->stdio + i, pipes[i]);
|
||||
if (err == 0)
|
||||
@ -493,15 +1027,6 @@ int uv_spawn(uv_loop_t* loop,
|
||||
goto error;
|
||||
}
|
||||
|
||||
/* Only activate this handle if exec() happened successfully */
|
||||
if (exec_errorno == 0) {
|
||||
QUEUE_INSERT_TAIL(&loop->process_handles, &process->queue);
|
||||
uv__handle_start(process);
|
||||
}
|
||||
|
||||
process->pid = pid;
|
||||
process->exit_cb = options->exit_cb;
|
||||
|
||||
if (pipes != pipes_storage)
|
||||
uv__free(pipes);
|
||||
|
||||
|
Reference in New Issue
Block a user