From 3759a0d94c18764247b66511d1038f2b93aa95de Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 2 Jun 2011 11:14:00 +0200 Subject: [PATCH] job control: introduce JOBCTL_PENDING_MASK and task_clear_jobctl_pending() This patch introduces JOBCTL_PENDING_MASK and replaces task_clear_jobctl_stop_pending() with task_clear_jobctl_pending() which takes an extra @mask argument. JOBCTL_PENDING_MASK is currently equal to JOBCTL_STOP_PENDING but future patches will add more bits. recalc_sigpending_tsk() is updated to use JOBCTL_PENDING_MASK instead. task_clear_jobctl_pending() takes @mask which in subset of JOBCTL_PENDING_MASK and clears the relevant jobctl bits. If JOBCTL_STOP_PENDING is set, other STOP bits are cleared together. All task_clear_jobctl_stop_pending() users are updated to call task_clear_jobctl_pending() with JOBCTL_STOP_PENDING which is functionally identical to task_clear_jobctl_stop_pending(). This patch doesn't cause any functional change. Signed-off-by: Tejun Heo Signed-off-by: Oleg Nesterov --- fs/exec.c | 2 +- include/linux/sched.h | 5 ++++- kernel/signal.c | 27 +++++++++++++++++---------- 3 files changed, 22 insertions(+), 12 deletions(-) diff --git a/fs/exec.c b/fs/exec.c index 8986bb0f9dc2..4402105287cb 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1772,7 +1772,7 @@ static int zap_process(struct task_struct *start, int exit_code) t = start; do { - task_clear_jobctl_stop_pending(t); + task_clear_jobctl_pending(t, JOBCTL_STOP_PENDING); if (t != current && t->mm) { sigaddset(&t->pending.signal, SIGKILL); signal_wake_up(t, 1); diff --git a/include/linux/sched.h b/include/linux/sched.h index b0dd064eb4fc..5a958b17f9fe 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1817,7 +1817,10 @@ extern void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t * #define JOBCTL_STOP_CONSUME (1 << JOBCTL_STOP_CONSUME_BIT) #define JOBCTL_TRAPPING (1 << JOBCTL_TRAPPING_BIT) -extern void task_clear_jobctl_stop_pending(struct task_struct *task); +#define JOBCTL_PENDING_MASK JOBCTL_STOP_PENDING + +extern void task_clear_jobctl_pending(struct task_struct *task, + unsigned int mask); #ifdef CONFIG_PREEMPT_RCU diff --git a/kernel/signal.c b/kernel/signal.c index 62a6c3bb9f0d..288d952fa3b8 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -124,7 +124,7 @@ static inline int has_pending_signals(sigset_t *signal, sigset_t *blocked) static int recalc_sigpending_tsk(struct task_struct *t) { - if ((t->jobctl & JOBCTL_STOP_PENDING) || + if ((t->jobctl & JOBCTL_PENDING_MASK) || PENDING(&t->pending, &t->blocked) || PENDING(&t->signal->shared_pending, &t->blocked)) { set_tsk_thread_flag(t, TIF_SIGPENDING); @@ -245,18 +245,25 @@ static void task_clear_jobctl_trapping(struct task_struct *task) } /** - * task_clear_jobctl_stop_pending - clear pending group stop + * task_clear_jobctl_pending - clear jobctl pending bits * @task: target task + * @mask: pending bits to clear * - * Clear group stop states for @task. + * Clear @mask from @task->jobctl. @mask must be subset of + * %JOBCTL_PENDING_MASK. If %JOBCTL_STOP_PENDING is being cleared, other + * STOP bits are cleared together. * * CONTEXT: * Must be called with @task->sighand->siglock held. */ -void task_clear_jobctl_stop_pending(struct task_struct *task) +void task_clear_jobctl_pending(struct task_struct *task, unsigned int mask) { - task->jobctl &= ~(JOBCTL_STOP_PENDING | JOBCTL_STOP_CONSUME | - JOBCTL_STOP_DEQUEUED); + BUG_ON(mask & ~JOBCTL_PENDING_MASK); + + if (mask & JOBCTL_STOP_PENDING) + mask |= JOBCTL_STOP_CONSUME | JOBCTL_STOP_DEQUEUED; + + task->jobctl &= ~mask; } /** @@ -282,7 +289,7 @@ static bool task_participate_group_stop(struct task_struct *task) WARN_ON_ONCE(!(task->jobctl & JOBCTL_STOP_PENDING)); - task_clear_jobctl_stop_pending(task); + task_clear_jobctl_pending(task, JOBCTL_STOP_PENDING); if (!consume) return false; @@ -810,7 +817,7 @@ static int prepare_signal(int sig, struct task_struct *p, int from_ancestor_ns) rm_from_queue(SIG_KERNEL_STOP_MASK, &signal->shared_pending); t = p; do { - task_clear_jobctl_stop_pending(t); + task_clear_jobctl_pending(t, JOBCTL_STOP_PENDING); rm_from_queue(SIG_KERNEL_STOP_MASK, &t->pending); wake_up_state(t, __TASK_STOPPED); } while_each_thread(p, t); @@ -926,7 +933,7 @@ static void complete_signal(int sig, struct task_struct *p, int group) signal->group_stop_count = 0; t = p; do { - task_clear_jobctl_stop_pending(t); + task_clear_jobctl_pending(t, JOBCTL_STOP_PENDING); sigaddset(&t->pending.signal, SIGKILL); signal_wake_up(t, 1); } while_each_thread(p, t); @@ -1161,7 +1168,7 @@ int zap_other_threads(struct task_struct *p) p->signal->group_stop_count = 0; while_each_thread(p, t) { - task_clear_jobctl_stop_pending(t); + task_clear_jobctl_pending(t, JOBCTL_STOP_PENDING); count++; /* Don't bother with already dead threads */