diff options
| author |   Oleg Nesterov <oleg@redhat.com> | 2020-06-30 17:32:54 +0200 |
|---|---|---|
| committer |   Jens Axboe <axboe@kernel.dk> | 2020-06-30 12:18:08 -0600 |
| commit | e91b48162332480f5840902268108bb7fb7a44c7 (patch) | |
| tree | c7cf68d7e37016bb5a7dc479d5396fee6f7bc776 /kernel/signal.c | |
| parent | io_uring: fix current->mm NULL dereference on exit (diff) | |
| download | wireguard-linux-e91b48162332480f5840902268108bb7fb7a44c7.tar.xz wireguard-linux-e91b48162332480f5840902268108bb7fb7a44c7.zip | |
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.c | 10 |
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 |