From:   "Eric W. Biederman" <ebiederm@xmission.com>
To:     linux-kernel@vger.kernel.org
Cc:     linux-arch@vger.kernel.org,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Alexey Gladkov <legion@kernel.org>,
        Kyle Huey <me@kylehuey.com>, Oleg Nesterov <oleg@redhat.com>,
        Kees Cook <keescook@chromium.org>,
        Al Viro <viro@ZenIV.linux.org.uk>,
        Heiko Carstens <hca@linux.ibm.com>,
        Vasily Gorbik <gor@linux.ibm.com>,
        Christian Borntraeger <borntraeger@de.ibm.com>,
        Alexander Gordeev <agordeev@linux.ibm.com>,
        Martin Schwidefsky <schwidefsky@de.ibm.com>,
        "Eric W. Biederman" <ebiederm@xmission.com>
Date:   Wed,  8 Dec 2021 14:25:32 -0600
Message-Id: <20211208202532.16409-10-ebiederm@xmission.com>
In-Reply-To: <87a6ha4zsd.fsf@email.froward.int.ebiederm.org>
References: <87a6ha4zsd.fsf@email.froward.int.ebiederm.org>
MIME-Version: 1.0
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Subject: [PATCH 10/10] exit/kthread: Move the exit code for kernel threads into struct kthread
Precedence: bulk

The exit code of kernel threads has different semantics than the
exit_code of userspace tasks.  To avoid confusion and allow
the userspace implementation to change as needed move
the kernel thread exit code into struct kthread.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
---
 kernel/kthread.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/kernel/kthread.c b/kernel/kthread.c
index 8e5f44bed027..9c6c532047c4 100644
--- a/kernel/kthread.c
+++ b/kernel/kthread.c
@@ -52,6 +52,7 @@ struct kthread_create_info
 struct kthread {
 	unsigned long flags;
 	unsigned int cpu;
+	int result;
 	int (*threadfn)(void *);
 	void *data;
 	mm_segment_t oldfs;
@@ -287,7 +288,9 @@ EXPORT_SYMBOL_GPL(kthread_parkme);
  */
 void __noreturn kthread_exit(long result)
 {
-	do_exit(result);
+	struct kthread *kthread = to_kthread(current);
+	kthread->result = result;
+	do_exit(0);
 }
 
 /**
@@ -679,7 +682,7 @@ int kthread_stop(struct task_struct *k)
 	kthread_unpark(k);
 	wake_up_process(k);
 	wait_for_completion(&kthread->exited);
-	ret = k->exit_code;
+	ret = kthread->result;
 	put_task_struct(k);
 
 	trace_sched_kthread_stop_ret(ret);
-- 
2.29.2