Merge tag 'task_work-2021-01-19' of git://git.kernel.dk/linux-block
Pull task_work fix from Jens Axboe:
"The TIF_NOTIFY_SIGNAL change inadvertently removed the unconditional
task_work run we had in get_signal().
This caused a regression for some setups, since we're relying on eg
____fput() being run to close and release, for example, a pipe and
wake the other end.
For 5.11, I prefer the simple solution of just reinstating the
unconditional run, even if it conceptually doesn't make much sense -
if you need that kind of guarantee, you should be using TWA_SIGNAL
instead of TWA_NOTIFY. But it's the trivial fix for 5.11, and would
ensure that other potential gotchas/assumptions for task_work don't
regress for 5.11.
We're looking into further simplifying the task_work notifications for
5.12 which would resolve that too"
* tag 'task_work-2021-01-19' of git://git.kernel.dk/linux-block:
task_work: unconditionally run task_work from get_signal()
diff --git a/kernel/signal.c b/kernel/signal.c
index 5736c55a..6b9c431 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -2550,6 +2550,9 @@ bool get_signal(struct ksignal *ksig)
struct signal_struct *signal = current->signal;
int signr;
+ if (unlikely(current->task_works))
+ task_work_run();
+
/*
* For non-generic architectures, check for TIF_NOTIFY_SIGNAL so
* that the arch handlers don't all have to do it. If we get here