path: root/init/main.c
diff options
authorOleg Nesterov <oleg@tv-sign.ru>2008-04-30 00:53:03 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-04-30 08:29:37 -0700
commitfae5fa44f1fd079ffbed8e0add929dd7bbd1347f (patch)
tree8990ac958d29733cb61733ae69265472f5e1d13c /init/main.c
parent193191035ad6268db9f561e81e3474b8be89a5ba (diff)
signals: fix /sbin/init protection from unwanted signals
The global init has a lot of long standing problems with the unhandled fatal signals. - The "is_global_init(current)" check in get_signal_to_deliver() protects only the main thread. Sub-thread can dequee the fatal signal and shutdown the whole thread group except the main thread. If it dequeues SIGSTOP /sbin/init will be stopped, this is not right too. Note that we can't use is_global_init(->group_leader), this breaks exec and this can't solve other problems we have. - Even if afterwards ignored, the fatal signals sets SIGNAL_GROUP_EXIT on delivery. This breaks exec, has other bad implications, and this is just wrong. Introduce the new SIGNAL_UNKILLABLE flag to fix these problems. It also helps to solve some other problems addressed by the subsequent patches. Currently we use this flag for the global init only, but it could also be used by kthreads and (perhaps) by the sub-namespace inits. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'init/main.c')
1 files changed, 2 insertions, 0 deletions
diff --git a/init/main.c b/init/main.c
index 624266b524d..1f4406477f8 100644
--- a/init/main.c
+++ b/init/main.c
@@ -802,6 +802,8 @@ static int noinline init_post(void)
(void) sys_dup(0);
(void) sys_dup(0);
+ current->signal->flags |= SIGNAL_UNKILLABLE;
if (ramdisk_execute_command) {
printk(KERN_WARNING "Failed to execute %s\n",