[PATCH 2/6] mailbox: Not protect module_put with spin_lock_irqsave

"Peng Fan (OSS)" <[email protected]> Fri, 11 Apr 2025 21:14:10 +0800
Newsgroups dev.linux.lists.mailbox,org.kernel.vger.linux-kernel
Message-ID <[email protected]>
From: Peng Fan <[email protected]>

&chan->lock is not supposed to protect 'chan->mbox'.
And in __mbox_bind_client, try_module_get is also not protected
by &chan->lock. So move module_put out of the lock protected
region.

Signed-off-by: Peng Fan <[email protected]>
---
 drivers/mailbox/mailbox.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mailbox/mailbox.c b/drivers/mailbox/mailbox.c
index e5e2a66355a712e71a92e4ad339e99d7ff8e34be..3ecf92a580fef031d8add5e4c2e4df494a34010a 100644
--- a/drivers/mailbox/mailbox.c
+++ b/drivers/mailbox/mailbox.c
@@ -486,8 +486,8 @@ void mbox_free_channel(struct mbox_chan *chan)
 	if (chan->txdone_method == TXDONE_BY_ACK)
 		chan->txdone_method = TXDONE_BY_POLL;
 
-	module_put(chan->mbox->dev->driver->owner);
 	spin_unlock_irqrestore(&chan->lock, flags);
+	module_put(chan->mbox->dev->driver->owner);
 }
 EXPORT_SYMBOL_GPL(mbox_free_channel);
 

-- 
2.37.1