diff options
Diffstat (limited to 'Utilities/cmlibuv/src/unix/process.c')
| -rw-r--r-- | Utilities/cmlibuv/src/unix/process.c | 786 |
1 files changed, 661 insertions, 125 deletions
diff --git a/Utilities/cmlibuv/src/unix/process.c b/Utilities/cmlibuv/src/unix/process.c index 2af2088f90..0de5c4695b 100644 --- a/Utilities/cmlibuv/src/unix/process.c +++ b/Utilities/cmlibuv/src/unix/process.c @@ -27,6 +27,7 @@ #include <assert.h> #include <errno.h> #include <signal.h> +#include <string.h> #include <sys/types.h> #include <sys/wait.h> @@ -35,9 +36,22 @@ #include <poll.h> #include <sched.h> -#if defined(__APPLE__) && !TARGET_OS_IPHONE +#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 @@ -61,21 +75,35 @@ extern char **environ; #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; - uv_loop_t* loop; int exit_status; int term_signal; int status; + int options; pid_t pid; QUEUE pending; QUEUE* q; QUEUE* h; - assert(signum == SIGCHLD); - QUEUE_INIT(&pending); - loop = handle->loop; h = &loop->process_handles; q = QUEUE_HEAD(h); @@ -83,19 +111,33 @@ static void uv__chld(uv_signal_t* handle, int signum) { 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, WNOHANG); + pid = waitpid(process->pid, &status, options); while (pid == -1 && errno == EINTR); - if (pid == 0) +#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); @@ -206,16 +248,14 @@ static void uv__write_int(int fd, int val) { n = write(fd, &val, sizeof(val)); while (n == -1 && errno == EINTR); - if (n == -1 && errno == EPIPE) - return; /* parent process has quit */ - - assert(n == sizeof(val)); + /* 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)); - _exit(127); } @@ -273,22 +313,31 @@ static void uv__process_child_init(const uv_process_options_t* options, 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 = pipes[fd][0]; + 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 - */ + /* 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; @@ -297,28 +346,27 @@ static void uv__process_child_init(const uv_process_options_t* options, } } - if (fd == use_fd) - uv__cloexec_fcntl(use_fd, 0); - else + 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) + if (fd <= 2 && close_fd == -1) uv__nonblock_fcntl(fd, 0); if (close_fd >= stdio_count) uv__close(close_fd); } - for (fd = 0; fd < stdio_count; fd++) { - use_fd = pipes[fd][1]; - - if (use_fd >= stdio_count) - uv__close(use_fd); - } - if (options->cwd != NULL && chdir(options->cwd)) uv__write_errno(error_fd); @@ -361,9 +409,8 @@ static void uv__process_child_init(const uv_process_options_t* options, #endif #endif - if (options->env != NULL) { + if (options->env != NULL) environ = options->env; - } /* Reset signal mask just before exec. */ sigemptyset(&signewset); @@ -377,11 +424,555 @@ static void uv__process_child_init(const uv_process_options_t* options, #endif uv__write_errno(error_fd); - abort(); } #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) { @@ -389,18 +980,13 @@ 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; if (options->cpumask != NULL) { #ifndef CMAKE_BOOTSTRAP @@ -427,6 +1013,7 @@ 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) @@ -451,92 +1038,43 @@ 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; - +#ifdef UV_USE_SIGCHLD 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); - - /* 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) - err = UV__ERR(errno); - - if (pid == 0) - uv__process_child_init(options, stdio_count, pipes, signal_pipe[1]); - - if (pthread_sigmask(SIG_SETMASK, &sigoldset, NULL) != 0) - abort(); + /* Spawn the child */ + exec_errorno = uv__spawn_and_init_child(loop, options, stdio_count, pipes, &pid); - /* Release lock in parent process */ - uv_rwlock_wrunlock(&loop->cloexec_lock); +#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 - uv__close(signal_pipe[1]); + /* 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 - 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) @@ -548,15 +1086,6 @@ 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); @@ -589,9 +1118,16 @@ int uv_process_kill(uv_process_t* process, int signum) { int uv_kill(int pid, int signum) { - if (kill(pid, 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 + } else return 0; } |