sysrq: Fix possible race with exiting task

sysrq should grab the tasklist lock, otherwise calling force_sig() is
not safe, as it might race with exiting task, which ->sighand might be
set to NULL already.

Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Anton Vorontsov 2012-02-07 10:49:39 +04:00 committed by Greg Kroah-Hartman
parent 6f56d0f436
commit e502babe0a
1 changed files with 2 additions and 0 deletions

View File

@ -322,11 +322,13 @@ static void send_sig_all(int sig)
{
struct task_struct *p;
read_lock(&tasklist_lock);
for_each_process(p) {
if (p->mm && !is_global_init(p))
/* Not swapper, init nor kernel thread */
force_sig(sig, p);
}
read_unlock(&tasklist_lock);
}
static void sysrq_handle_term(int key)