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authorRoland McGrath <roland@gnu.org>2003-03-15 23:44:08 +0000
committerRoland McGrath <roland@gnu.org>2003-03-15 23:44:08 +0000
commit7eecc0c21a4ee25034fb6a0f81ca438668244361 (patch)
treecb2318e7cd13d38016c12bb756099703491d178d /sysdeps/unix/sysv/linux/system.c
parent45e4762c2c7d04cd51213735c2b440c94cdcf28a (diff)
* sysdeps/unix/sysv/linux/i386/system.c: Moved to ...
* sysdeps/unix/sysv/linux/system.c: ... here. (FORK): Don't #define if already #define'd. * sysdeps/unix/sysv/linux/s390/system.c: File removed. * sysdeps/unix/sysv/linux/kernel-features.h [__powerpc__]: (__ASSUME_CLONE_THREAD_FLAGS): Define for kernel >= 2.5.64.
Diffstat (limited to 'sysdeps/unix/sysv/linux/system.c')
-rw-r--r--sysdeps/unix/sysv/linux/system.c71
1 files changed, 71 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/system.c b/sysdeps/unix/sysv/linux/system.c
index 0f56a81ed1..ffb308b045 100644
--- a/sysdeps/unix/sysv/linux/system.c
+++ b/sysdeps/unix/sysv/linux/system.c
@@ -1,2 +1,73 @@
+/* Copyright (C) 2002, 2003 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, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+
+#include <sched.h>
+#include <signal.h>
+#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
+
+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)
+
+
/* Linux has waitpid(), so override the generic unix version. */
#include <sysdeps/posix/system.c>
+
+
+/* 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 ();
+}