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authorOleg Nesterov <oleg@redhat.com>2020-06-30 17:32:54 +0200
committerJens Axboe <axboe@kernel.dk>2020-06-30 12:18:08 -0600
commite91b48162332480f5840902268108bb7fb7a44c7 (patch)
treec7cf68d7e37016bb5a7dc479d5396fee6f7bc776 /kernel/signal.c
parentd60b5fbc1ce8210759b568da49d149b868e7c6d3 (diff)
task_work: teach task_work_add() to do signal_wake_up()
So that the target task will exit the wait_event_interruptible-like loop and call task_work_run() asap. The patch turns "bool notify" into 0,TWA_RESUME,TWA_SIGNAL enum, the new TWA_SIGNAL flag implies signal_wake_up(). However, it needs to avoid the race with recalc_sigpending(), so the patch also adds the new JOBCTL_TASK_WORK bit included in JOBCTL_PENDING_MASK. TODO: once this patch is merged we need to change all current users of task_work_add(notify = true) to use TWA_RESUME. Cc: stable@vger.kernel.org # v5.7 Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'kernel/signal.c')
-rw-r--r--kernel/signal.c10
1 files changed, 7 insertions, 3 deletions
diff --git a/kernel/signal.c b/kernel/signal.c
index 5ca48cc5da76..ee22ec78fd6d 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -2529,9 +2529,6 @@ bool get_signal(struct ksignal *ksig)
struct signal_struct *signal = current->signal;
int signr;
- if (unlikely(current->task_works))
- task_work_run();
-
if (unlikely(uprobe_deny_signal()))
return false;
@@ -2544,6 +2541,13 @@ bool get_signal(struct ksignal *ksig)
relock:
spin_lock_irq(&sighand->siglock);
+ current->jobctl &= ~JOBCTL_TASK_WORK;
+ if (unlikely(current->task_works)) {
+ spin_unlock_irq(&sighand->siglock);
+ task_work_run();
+ goto relock;
+ }
+
/*
* Every stopped thread goes here after wakeup. Check to see if
* we should notify the parent, prepare_signal(SIGCONT) encodes