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| author | Jens Axboe <axboe@kernel.dk> | 2021-01-05 11:32:43 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-01-04 11:39:23 +0100 |
| commit | 6ef2b4728a00c98cc1163212443e39d79a4c2c94 (patch) | |
| tree | 568864b7a65e058bdae17df6637917544c4a44ea | |
| parent | c91ab04781f9e46c1a2143bd1ba8fc1f1aff6ebc (diff) | |
task_work: unconditionally run task_work from get_signal()
[ Upstream commit 35d0b389f3b23439ad15b610d6e43fc72fc75779 ]
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -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 f528a91d6734..e487c4660921 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -2520,6 +2520,9 @@ 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 |