From 7dd3db54e77d21eb95e145f19ba53f68250d0e73 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 2 Jun 2011 11:14:00 +0200 Subject: job control: introduce task_set_jobctl_pending() task->jobctl currently hosts JOBCTL_STOP_PENDING and will host TRAP pending bits too. Setting pending conditions on a dying task may make the task unkillable. Currently, each setting site is responsible for checking for the condition but with to-be-added job control traps this becomes too fragile. This patch adds task_set_jobctl_pending() which should be used when setting task->jobctl bits to schedule a stop or trap. The function performs the followings to ease setting pending bits. * Sanity checks. * If fatal signal is pending or PF_EXITING is set, no bit is set. * STOP_SIGMASK is automatically cleared if new value is being set. do_signal_stop() and ptrace_attach() are updated to use task_set_jobctl_pending() instead of setting STOP_PENDING explicitly. The surrounding structures around setting are changed to fit task_set_jobctl_pending() better but there should be no userland visible behavior difference. Signed-off-by: Tejun Heo Cc: Oleg Nesterov Signed-off-by: Oleg Nesterov --- kernel/ptrace.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'kernel/ptrace.c') diff --git a/kernel/ptrace.c b/kernel/ptrace.c index eb191116edf..0c37d999c8b 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -256,10 +256,10 @@ static int ptrace_attach(struct task_struct *task) * The following task_is_stopped() test is safe as both transitions * in and out of STOPPED are protected by siglock. */ - if (task_is_stopped(task)) { - task->jobctl |= JOBCTL_STOP_PENDING | JOBCTL_TRAPPING; + if (task_is_stopped(task) && + task_set_jobctl_pending(task, + JOBCTL_STOP_PENDING | JOBCTL_TRAPPING)) signal_wake_up(task, 1); - } spin_unlock(&task->sighand->siglock); -- cgit v1.2.3-70-g09d2