From: Jens Axboe <axboe@kernel.dk>
Date: Fri, 26 Mar 2021 14:57:10 +0000 (-0600)
Subject: kernel: don't call do_exit() for PF_IO_WORKER threads
X-Git-Tag: v5.10.162~11
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=831cb78a2a5e86fe705ef4e3095c7cbc587c6a57;p=thirdparty%2Fkernel%2Fstable.git

kernel: don't call do_exit() for PF_IO_WORKER threads

[ Upstream commit 10442994ba195efef6fdcc0c3699e4633cb5161b ]

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, so just return
instead of 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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/kernel/signal.c b/kernel/signal.c
index 845d4912b83aa..fb5473724f5de 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -2754,6 +2754,14 @@ relock:
 			do_coredump(&ksig->info);
 		}
 
+		/*
+		 * 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.
+		 */
+		if (current->flags & PF_IO_WORKER)
+			goto out;
+
 		/*
 		 * Death signals, no core dump.
 		 */
@@ -2761,7 +2769,7 @@ relock:
 		/* NOTREACHED */
 	}
 	spin_unlock_irq(&sighand->siglock);
-
+out:
 	ksig->sig = signr;
 	return ksig->sig > 0;
 }