+++ /dev/null
-/* Guts of POSIX spawn interface. Generic POSIX.1 version.
- Copyright (C) 2000-2021 Free Software Foundation, Inc.
- This file is part of the GNU C Library.
-
- The GNU C Library is free software; you can redistribute it and/or
- modify it under the terms of the GNU Lesser General Public
- License as published by the Free Software Foundation; either
- version 2.1 of the License, or (at your option) any later version.
-
- The GNU C Library is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public
- License along with the GNU C Library; if not, see
- <https://www.gnu.org/licenses/>. */
-
-#include <spawn.h>
-#include <assert.h>
-#include <fcntl.h>
-#include <paths.h>
-#include <string.h>
-#include <sys/resource.h>
-#include <sys/wait.h>
-#include <sys/param.h>
-#include <sys/mman.h>
-#include <not-cancel.h>
-#include <local-setxid.h>
-#include <shlib-compat.h>
-#include <pthreadP.h>
-#include <dl-sysdep.h>
-#include <libc-pointer-arith.h>
-#include <ldsodefs.h>
-#include "spawn_int.h"
-
-
-/* The Unix standard contains a long explanation of the way to signal
- an error after the fork() was successful. Since no new wait status
- was wanted there is no way to signal an error using one of the
- available methods. The committee chose to signal an error by a
- normal program exit with the exit code 127. */
-#define SPAWN_ERROR 127
-
-struct posix_spawn_args
-{
- sigset_t oldmask;
- const char *file;
- int (*exec) (const char *, char *const *, char *const *);
- const posix_spawn_file_actions_t *fa;
- const posix_spawnattr_t *restrict attr;
- char *const *argv;
- ptrdiff_t argc;
- char *const *envp;
- int xflags;
- int pipe[2];
-};
-
-/* Older version requires that shell script without shebang definition
- to be called explicitly using /bin/sh (_PATH_BSHELL). */
-static void
-maybe_script_execute (struct posix_spawn_args *args)
-{
- if (SHLIB_COMPAT (libc, GLIBC_2_2, GLIBC_2_15)
- && (args->xflags & SPAWN_XFLAGS_TRY_SHELL) && errno == ENOEXEC)
- {
- char *const *argv = args->argv;
- ptrdiff_t argc = args->argc;
-
- /* Construct an argument list for the shell. */
- char *new_argv[argc + 2];
- new_argv[0] = (char *) _PATH_BSHELL;
- new_argv[1] = (char *) args->file;
- if (argc > 1)
- memcpy (new_argv + 2, argv + 1, argc * sizeof (char *));
- else
- new_argv[2] = NULL;
-
- /* Execute the shell. */
- args->exec (new_argv[0], new_argv, args->envp);
- }
-}
-
-/* Function used in the clone call to setup the signals mask, posix_spawn
- attributes, and file actions. */
-static int
-__spawni_child (void *arguments)
-{
- struct posix_spawn_args *args = arguments;
- const posix_spawnattr_t *restrict attr = args->attr;
- const posix_spawn_file_actions_t *file_actions = args->fa;
- int ret;
-
- __close (args->pipe[0]);
-
- /* Set signal default action. */
- if ((attr->__flags & POSIX_SPAWN_SETSIGDEF) != 0)
- {
- /* We have to iterate over all signals. This could possibly be
- done better but it requires system specific solutions since
- the sigset_t data type can be very different on different
- architectures. */
- int sig;
- struct sigaction sa;
-
- memset (&sa, '\0', sizeof (sa));
- sa.sa_handler = SIG_DFL;
-
- for (sig = 1; sig <= _NSIG; ++sig)
- if (__sigismember (&attr->__sd, sig) != 0
- && __sigaction (sig, &sa, NULL) != 0)
- goto fail;
- }
-
-#ifdef _POSIX_PRIORITY_SCHEDULING
- /* Set the scheduling algorithm and parameters. */
- if ((attr->__flags & (POSIX_SPAWN_SETSCHEDPARAM | POSIX_SPAWN_SETSCHEDULER))
- == POSIX_SPAWN_SETSCHEDPARAM)
- {
- if (__sched_setparam (0, &attr->__sp) == -1)
- goto fail;
- }
- else if ((attr->__flags & POSIX_SPAWN_SETSCHEDULER) != 0)
- {
- if (__sched_setscheduler (0, attr->__policy, &attr->__sp) == -1)
- goto fail;
- }
-#endif
-
- /* Set the process session ID. */
- if ((attr->__flags & POSIX_SPAWN_SETSID) != 0
- && __setsid () < 0)
- goto fail;
-
- /* Set the process group ID. */
- if ((attr->__flags & POSIX_SPAWN_SETPGROUP) != 0
- && __setpgid (0, attr->__pgrp) != 0)
- goto fail;
-
- /* Set the effective user and group IDs. */
- if ((attr->__flags & POSIX_SPAWN_RESETIDS) != 0
- && (local_seteuid (__getuid ()) != 0
- || local_setegid (__getgid ())) != 0)
- goto fail;
-
- /* Execute the file actions. */
- if (file_actions != NULL)
- {
- int cnt;
- struct rlimit64 fdlimit;
- bool have_fdlimit = false;
-
- for (cnt = 0; cnt < file_actions->__used; ++cnt)
- {
- struct __spawn_action *action = &file_actions->__actions[cnt];
-
- switch (action->tag)
- {
- case spawn_do_close:
- if (__close_nocancel (action->action.close_action.fd) != 0)
- {
- if (have_fdlimit == 0)
- {
- __getrlimit64 (RLIMIT_NOFILE, &fdlimit);
- have_fdlimit = true;
- }
-
- /* Only signal errors for file descriptors out of range. */
- if (action->action.close_action.fd < 0
- || action->action.close_action.fd >= fdlimit.rlim_cur)
- goto fail;
- }
- break;
-
- case spawn_do_open:
- {
- /* POSIX states that if fildes was already an open file descriptor,
- it shall be closed before the new file is opened. This avoid
- pontential issues when posix_spawn plus addopen action is called
- with the process already at maximum number of file descriptor
- opened and also for multiple actions on single-open special
- paths (like /dev/watchdog). */
- __close_nocancel (action->action.open_action.fd);
-
- int new_fd = __open_nocancel (action->action.open_action.path,
- action->action.open_action.oflag
- | O_LARGEFILE,
- action->action.open_action.mode);
-
- if (new_fd == -1)
- goto fail;
-
- /* Make sure the desired file descriptor is used. */
- if (new_fd != action->action.open_action.fd)
- {
- if (__dup2 (new_fd, action->action.open_action.fd)
- != action->action.open_action.fd)
- goto fail;
-
- if (__close_nocancel (new_fd) != 0)
- goto fail;
- }
- }
- break;
-
- case spawn_do_dup2:
- /* Austin Group issue #411 requires adddup2 action with source
- and destination being equal to remove close-on-exec flag. */
- if (action->action.dup2_action.fd
- == action->action.dup2_action.newfd)
- {
- int fd = action->action.dup2_action.newfd;
- int flags = __fcntl (fd, F_GETFD, 0);
- if (flags == -1)
- goto fail;
- if (__fcntl (fd, F_SETFD, flags & ~FD_CLOEXEC) == -1)
- goto fail;
- }
- else if (__dup2 (action->action.dup2_action.fd,
- action->action.dup2_action.newfd)
- != action->action.dup2_action.newfd)
- goto fail;
- break;
-
- case spawn_do_chdir:
- if (__chdir (action->action.chdir_action.path) != 0)
- goto fail;
- break;
-
- case spawn_do_fchdir:
- if (__fchdir (action->action.fchdir_action.fd) != 0)
- goto fail;
- break;
-
- case spawn_do_closefrom:
- __set_errno (EINVAL);
- goto fail;
- }
- }
- }
-
- /* Set the initial signal mask of the child if POSIX_SPAWN_SETSIGMASK
- is set, otherwise restore the previous one. */
- __sigprocmask (SIG_SETMASK, (attr->__flags & POSIX_SPAWN_SETSIGMASK)
- ? &attr->__ss : &args->oldmask, 0);
-
- args->exec (args->file, args->argv, args->envp);
-
- /* This is compatibility function required to enable posix_spawn run
- script without shebang definition for older posix_spawn versions
- (2.15). */
- maybe_script_execute (args);
-
-fail:
- /* errno should have an appropriate non-zero value; otherwise,
- there's a bug in glibc or the kernel. For lack of an error code
- (EINTERNALBUG) describing that, use ECHILD. Another option would
- be to set args->err to some negative sentinel and have the parent
- abort(), but that seems needlessly harsh. */
- ret = errno ? : ECHILD;
- if (ret)
- /* Since sizeof errno < PIPE_BUF, the write is atomic. */
- while (__write_nocancel (args->pipe[1], &ret, sizeof (ret)) < 0);
-
- _exit (SPAWN_ERROR);
-}
-
-/* Spawn a new process executing PATH with the attributes describes in *ATTRP.
- Before running the process perform the actions described in FILE-ACTIONS. */
-int
-__spawnix (pid_t *pid, const char *file,
- const posix_spawn_file_actions_t *file_actions,
- const posix_spawnattr_t *attrp, char *const argv[],
- char *const envp[], int xflags,
- int (*exec) (const char *, char *const *, char *const *))
-{
- struct posix_spawn_args args;
- int ec;
-
- if (__pipe2 (args.pipe, O_CLOEXEC))
- return errno;
-
- /* Disable asynchronous cancellation. */
- int state;
- __libc_ptf_call (__pthread_setcancelstate,
- (PTHREAD_CANCEL_DISABLE, &state), 0);
-
- ptrdiff_t argc = 0;
- ptrdiff_t limit = INT_MAX - 1;
- while (argv[argc++] != NULL)
- if (argc == limit)
- {
- errno = E2BIG;
- return errno;
- }
-
- args.file = file;
- args.exec = exec;
- args.fa = file_actions;
- args.attr = attrp ? attrp : &(const posix_spawnattr_t) { 0 };
- args.argv = argv;
- args.argc = argc;
- args.envp = envp;
- args.xflags = xflags;
-
- /* Generate the new process. */
- pid_t new_pid = __fork ();
-
- if (new_pid == 0)
- __spawni_child (&args);
- else if (new_pid > 0)
- {
- __close (args.pipe[1]);
-
- if (__read (args.pipe[0], &ec, sizeof ec) != sizeof ec)
- ec = 0;
- else
- __waitpid (new_pid, &(int) { 0 }, 0);
- }
- else
- ec = errno;
-
- __close (args.pipe[0]);
-
- if ((ec == 0) && (pid != NULL))
- *pid = new_pid;
-
- __libc_ptf_call (__pthread_setcancelstate, (state, NULL), 0);
-
- return ec;
-}
-
-int
-__spawni (pid_t * pid, const char *file,
- const posix_spawn_file_actions_t * acts,
- const posix_spawnattr_t * attrp, char *const argv[],
- char *const envp[], int xflags)
-{
- /* It uses __execvpex to avoid run ENOEXEC in non compatibility mode (it
- will be handled by maybe_script_execute). */
- return __spawnix (pid, file, acts, attrp, argv, envp, xflags,
- xflags & SPAWN_XFLAGS_USE_PATH ? __execvpex : __execve);
-}
git://sourceware.org / glibc.git / commitdiff