| /* Copyright (C) 2002-2018 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 |
| <http://www.gnu.org/licenses/>. */ |
| |
| #include <sched.h> |
| #include <signal.h> |
| #include <string.h> /* For the real memset prototype. */ |
| #include <sysdep.h> |
| #include <unistd.h> |
| #include <sys/wait.h> |
| #include <libc-lock.h> |
| |
| /* We have to and actually can handle cancelable system(). The big |
| problem: we have to kill the child process if necessary. To do |
| this a cleanup handler has to be registered and is has to be able |
| to find the PID of the child. The main problem is to reliable have |
| the PID when needed. It is not necessary for the parent thread to |
| return. It might still be in the kernel when the cancellation |
| request comes. Therefore we have to use the clone() calls ability |
| to have the kernel write the PID into the user-level variable. */ |
| #ifndef FORK |
| # define FORK() \ |
| INLINE_SYSCALL (clone, 3, CLONE_PARENT_SETTID | SIGCHLD, 0, &pid) |
| #endif |
| |
| #ifdef _LIBC_REENTRANT |
| static void cancel_handler (void *arg); |
| |
| # define CLEANUP_HANDLER \ |
| __libc_cleanup_region_start (1, cancel_handler, &pid) |
| |
| # define CLEANUP_RESET \ |
| __libc_cleanup_region_end (0) |
| #endif |
| |
| |
| /* Linux has waitpid(), so override the generic unix version. */ |
| #include <sysdeps/posix/system.c> |
| |
| |
| #ifdef _LIBC_REENTRANT |
| /* The cancellation handler. */ |
| static void |
| cancel_handler (void *arg) |
| { |
| pid_t child = *(pid_t *) arg; |
| |
| INTERNAL_SYSCALL_DECL (err); |
| INTERNAL_SYSCALL (kill, err, 2, child, SIGKILL); |
| |
| TEMP_FAILURE_RETRY (__waitpid (child, NULL, 0)); |
| |
| DO_LOCK (); |
| |
| if (SUB_REF () == 0) |
| { |
| (void) __sigaction (SIGQUIT, &quit, (struct sigaction *) NULL); |
| (void) __sigaction (SIGINT, &intr, (struct sigaction *) NULL); |
| } |
| |
| DO_UNLOCK (); |
| } |
| #endif |