diff options
| -rw-r--r-- | include/linux/sched.h | 2 | ||||
| -rw-r--r-- | kernel/ptrace.c | 6 | ||||
| -rw-r--r-- | kernel/signal.c | 46 |
3 files changed, 45 insertions, 9 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h index 5a958b1..5157bd9 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1819,6 +1819,8 @@ extern void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t * #define JOBCTL_PENDING_MASK JOBCTL_STOP_PENDING +extern bool task_set_jobctl_pending(struct task_struct *task, + unsigned int mask); extern void task_clear_jobctl_pending(struct task_struct *task, unsigned int mask); diff --git a/kernel/ptrace.c b/kernel/ptrace.c index eb19111..0c37d99 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); diff --git a/kernel/signal.c b/kernel/signal.c index 637a171..9ab91c5 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -224,6 +224,39 @@ static inline void print_dropped_signal(int sig) } /** + * task_set_jobctl_pending - set jobctl pending bits + * @task: target task + * @mask: pending bits to set + * + * Clear @mask from @task->jobctl. @mask must be subset of + * %JOBCTL_PENDING_MASK | %JOBCTL_STOP_CONSUME | %JOBCTL_STOP_SIGMASK | + * %JOBCTL_TRAPPING. If stop signo is being set, the existing signo is + * cleared. If @task is already being killed or exiting, this function + * becomes noop. + * + * CONTEXT: + * Must be called with @task->sighand->siglock held. + * + * RETURNS: + * %true if @mask is set, %false if made noop because @task was dying. + */ +bool task_set_jobctl_pending(struct task_struct *task, unsigned int mask) +{ + BUG_ON(mask & ~(JOBCTL_PENDING_MASK | JOBCTL_STOP_CONSUME | + JOBCTL_STOP_SIGMASK | JOBCTL_TRAPPING)); + BUG_ON((mask & JOBCTL_TRAPPING) && !(mask & JOBCTL_PENDING_MASK)); + + if (unlikely(fatal_signal_pending(task) || (task->flags & PF_EXITING))) + return false; + + if (mask & JOBCTL_STOP_SIGMASK) + task->jobctl &= ~JOBCTL_STOP_SIGMASK; + + task->jobctl |= mask; + return true; +} + +/** * task_clear_jobctl_trapping - clear jobctl trapping bit * @task: target task * @@ -1902,19 +1935,20 @@ static int do_signal_stop(int signr) else WARN_ON_ONCE(!task_ptrace(current)); - current->jobctl &= ~JOBCTL_STOP_SIGMASK; - current->jobctl |= signr | gstop; - sig->group_stop_count = 1; + sig->group_stop_count = 0; + + if (task_set_jobctl_pending(current, signr | gstop)) + sig->group_stop_count++; + for (t = next_thread(current); t != current; t = next_thread(t)) { - t->jobctl &= ~JOBCTL_STOP_SIGMASK; /* * Setting state to TASK_STOPPED for a group * stop is always done with the siglock held, * so this check has no races. */ - if (!(t->flags & PF_EXITING) && !task_is_stopped(t)) { - t->jobctl |= signr | gstop; + if (!task_is_stopped(t) && + task_set_jobctl_pending(t, signr | gstop)) { sig->group_stop_count++; signal_wake_up(t, 0); } |
