mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-24 05:50:14 +00:00
78 lines
2.5 KiB
C
78 lines
2.5 KiB
C
/* Copyright (C) 2002, 2003, 2005 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 <bits/libc-lock.h>
|
|
#include <kernel-features.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. */
|
|
#if defined __ASSUME_CLONE_THREAD_FLAGS && !defined 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
|