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| author | Jens Axboe <axboe@kernel.dk> | 2021-01-05 11:32:43 -0700 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2021-01-08 09:14:21 -0700 |
| commit | 35d0b389f3b23439ad15b610d6e43fc72fc75779 (patch) | |
| tree | 0db600fd2906e728692e0788874e2df3823b7a00 /kernel | |
| parent | e71ba9452f0b5b2e8dc8aa5445198cd9214a6a62 (diff) | |
| download | linux-35d0b389f3b23439ad15b610d6e43fc72fc75779.tar.bz2 | |
task_work: unconditionally run task_work from get_signal()
Song reported a boot regression in a kvm image with 5.11-rc, and bisected
it down to the below patch. Debugging this issue, turns out that the boot
stalled when a task is waiting on a pipe being released. As we no longer
run task_work from get_signal() unless it's queued with TWA_SIGNAL, the
task goes idle without running the task_work. This prevents ->release()
from being called on the pipe, which another boot task is waiting on.
For now, re-instate the unconditional task_work run from get_signal().
For 5.12, we'll collapse TWA_RESUME and TWA_SIGNAL, as it no longer
makes sense to have a distinction between the two. This will turn
task_work notification into a simple boolean, whether to notify or not.
Fixes: 98b89b649fce ("signal: kill JOBCTL_TASK_WORK")
Reported-by: Song Liu <songliubraving@fb.com>
Tested-by: John Stultz <john.stultz@linaro.org>
Tested-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # LLVM/Clang version 11.0.1
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/signal.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/kernel/signal.c b/kernel/signal.c index 5736c55aaa1a..6b9c431da08f 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 |