diff options
Diffstat (limited to 'REORG.TODO/sysdeps/unix/sysv/linux/system.c')
-rw-r--r-- | REORG.TODO/sysdeps/unix/sysv/linux/system.c | 76 |
1 files changed, 76 insertions, 0 deletions
diff --git a/REORG.TODO/sysdeps/unix/sysv/linux/system.c b/REORG.TODO/sysdeps/unix/sysv/linux/system.c new file mode 100644 index 0000000000..012ffd828d --- /dev/null +++ b/REORG.TODO/sysdeps/unix/sysv/linux/system.c @@ -0,0 +1,76 @@ +/* Copyright (C) 2002-2017 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 |