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authorUlrich Drepper <drepper@redhat.com>2002-12-17 06:52:45 +0000
committerUlrich Drepper <drepper@redhat.com>2002-12-17 06:52:45 +0000
commit3ca97e8f0f08c85aecc08f5f171e46729e04911d (patch)
tree6a5d1517f52d649f0a46ba6dbf6bf1bf55b072d2 /sysdeps
parent26a026b94036e2e2a41a6693327d796cc82bdacd (diff)
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Update.
* sysdeps/posix/system.c (do_system): Add support for installation of cancellation handlers. * sysdeps/unix/sysv/linux/i386/system.c: New file. * stdlib/Makefile (tests): Add tst-system. * stdlib/tst-system.c: New file.
Diffstat (limited to 'sysdeps')
-rw-r--r--sysdeps/posix/system.c12
-rw-r--r--sysdeps/unix/sysv/linux/i386/system.c67
2 files changed, 79 insertions, 0 deletions
diff --git a/sysdeps/posix/system.c b/sysdeps/posix/system.c
index bca1c2ec3e..08852801a6 100644
--- a/sysdeps/posix/system.c
+++ b/sysdeps/posix/system.c
@@ -112,7 +112,15 @@ do_system (const char *line)
}
}
+#ifdef CLEANUP_HANDLER
+ CLEANUP_HANDLER;
+#endif
+
+#ifdef FORK
+ pid = FORK ();
+#else
pid = __fork ();
+#endif
if (pid == (pid_t) 0)
{
/* Child side. */
@@ -158,6 +166,10 @@ do_system (const char *line)
#endif
}
+#ifdef CLEANUP_HANDLER
+ CLEANUP_RESET;
+#endif
+
save = errno;
DO_LOCK ();
if ((SUB_REF () == 0
diff --git a/sysdeps/unix/sysv/linux/i386/system.c b/sysdeps/unix/sysv/linux/i386/system.c
new file mode 100644
index 0000000000..1107fd6668
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/i386/system.c
@@ -0,0 +1,67 @@
+/* Copyright (C) 2002 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>
+
+/* 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. */
+#define FORK() \
+ INLINE_SYSCALL (clone, 3, CLONE_PARENT_SETTID | SIGCHLD, 0, &pid)
+
+static void cancel_handler (void *arg);
+
+#define CLEANUP_HANDLER \
+ __libc_cleanup_region_start (0, 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)
+{
+ __kill (SIGKILL, *(pid_t *) arg);
+
+ TEMP_FAILURE_RETRY (waitpid (*(pid_t *) arg, NULL, 0));
+
+ DO_LOCK ();
+
+ if (SUB_REF () == 0)
+ {
+ (void) __sigaction (SIGQUIT, &quit, (struct sigaction *) NULL);
+ (void) __sigaction (SIGINT, &intr, (struct sigaction *) NULL);
+ }
+
+ DO_UNLOCK ();
+}