[PATCH 1/7] kernel: don't call do_exit() for PF_IO_WORKER threads

Jens Axboe
2021-03-26T15:52:43Z

Right now we're never calling get_signal() from PF_IO_WORKER threads, but
in preparation for doing so, don't handle a fatal signal for them. The
workers have state they need to cleanup when exiting, and they don't do
coredumps, so just return instead of performing either a dump or calling
do_exit() on their behalf. The threads themselves will detect a fatal
signal and do proper shutdown.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
kernel/signal.c | 9 +++++++++
1 file changed, 9 insertions(+)

diff --git a/kernel/signal.c b/kernel/signal.c
index f2a1b898da29..e3e1b8fbfe8a 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -2756,6 +2756,15 @@ bool get_signal(struct ksignal *ksig)
*/
current->flags |= PF_SIGNALED;

+ /*
+ * PF_IO_WORKER threads will catch and exit on fatal signals
+ * themselves. They have cleanup that must be performed, so
+ * we cannot call do_exit() on their behalf. coredumps also
+ * do not apply to them.
+ */
+ if (current->flags & PF_IO_WORKER)
+ return false;
+
if (sig_kernel_coredump(signr)) {
if (print_fatal_signals)
print_fatal_signal(ksig->info.si_signo);
--
2.31.0