diff options
| author | Oleg Nesterov <oleg@tv-sign.ru> | 2007-05-09 02:34:37 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-05-09 12:30:53 -0700 |
| commit | 10ab825bdef8df510f99c703a5a2d9b13a4e31a5 (patch) | |
| tree | e4db81f26c03ba5a5bff43ed44646a4ed4509d67 /include | |
| parent | 5de18d169739293e27e0cf9acfc75a2d2f4aa572 (diff) | |
| download | linux-10ab825bdef8df510f99c703a5a2d9b13a4e31a5.tar.bz2 | |
change kernel threads to ignore signals instead of blocking them
Currently kernel threads use sigprocmask(SIG_BLOCK) to protect against
signals. This doesn't prevent the signal delivery, this only blocks
signal_wake_up(). Every "killall -33 kthreadd" means a "struct siginfo"
leak.
Change kthreadd_setup() to set all handlers to SIG_IGN instead of blocking
them (make a new helper ignore_signals() for that). If the kernel thread
needs some signal, it should use allow_signal() anyway, and in that case it
should not use CLONE_SIGHAND.
Note that we can't change daemonize() (should die!) in the same way,
because it can be used along with CLONE_SIGHAND. This means that
allow_signal() still should unblock the signal to work correctly with
daemonize()ed threads.
However, disallow_signal() doesn't block the signal any longer but ignores
it.
NOTE: with or without this patch the kernel threads are not protected from
handle_stop_signal(), this seems harmless, but not good.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/sched.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h index 3d95c480f58d..28000b1658f9 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1317,6 +1317,7 @@ extern int in_egroup_p(gid_t); extern void proc_caches_init(void); extern void flush_signals(struct task_struct *); +extern void ignore_signals(struct task_struct *); extern void flush_signal_handlers(struct task_struct *, int force_default); extern int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info); |