From: Łukasz Stelmach <l.stelmach@samsung.com>
Date: Mon, 24 Jan 2022 13:53:39 +0000 (+0100)
Subject: WIP: fix log->mutex + misc_mtx ab-ba deadlock
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=refs%2Fheads%2Fsandbox%2Flstelmach%2Fdeadlock;p=platform%2Fkernel%2Flinux-tizen-modules-source.git

WIP: fix log->mutex + misc_mtx ab-ba deadlock

Change-Id: Ibaab2947638997dca82c0e47146f77ce0f1bee57
Signed-off-by: Łukasz Stelmach <l.stelmach@samsung.com>
---

diff --git a/kernel/logger.c b/kernel/logger.c
index 8b2cda9..cf5dd8a 100644
--- a/kernel/logger.c
+++ b/kernel/logger.c
@@ -689,11 +689,12 @@ static ssize_t logger_aio_write(struct kiocb *iocb, const struct iovec *iov,
 		if (writer->owner != current->group_leader) {
 			struct file *nfile;
 
+			mutex_unlock(&log->mutex);
 			nfile = make_new_file(file);
 			if (IS_ERR(nfile)) {
-				mutex_unlock(&log->mutex);
 				return PTR_ERR(nfile);
 			}
+			mutex_lock(&log->mutex);
 
 			file = nfile;
 			writer = file->private_data;
@@ -874,11 +875,12 @@ static ssize_t logger_write_iter(struct kiocb *iocb, struct iov_iter *from)
 		if (writer->owner != current->group_leader) {
 			struct file *nfile;
 
+			mutex_unlock(&log->mutex);
 			nfile = make_new_file(file);
 			if (IS_ERR(nfile)) {
-				mutex_unlock(&log->mutex);
 				return PTR_ERR(nfile);
 			}
+			mutex_lock(&log->mutex);
 
 			file = nfile;
 			writer = file->private_data;