linux-kernel - [PATCH] Mailbox: Complete wait event only if Tx was successful

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <1418242572-20998-1-git-send-email-ashwin.chaugule@linaro.org>
Date:	Wed, 10 Dec 2014 15:16:12 -0500
From:	Ashwin Chaugule <ashwin.chaugule@...aro.org>
To:	jaswinder.singh@...aro.org
Cc:	broonie@...nel.org, linux-kernel@...r.kernel.org,
	linux-arm-kernel@...ts.infradead.org, linaro-acpi@...ts.linaro.org,
	patches@...aro.org, arnd@...db.de,
	Ashwin Chaugule <ashwin.chaugule@...aro.org>
Subject: [PATCH] Mailbox: Complete wait event only if Tx was successful

If a wait_for_completion_timeout() call returns due to a timeout,
the mbox code can still call complete() after returning from the wait.
This can cause subsequent transmissions on a channel to fail, since
the wait_for_completion_timeout() sees the completion variable
is !=0, caused by the erroneous complete() call, and immediately
returns without waiting for the time as expected by the client.

Fix this by calling complete() only if the TX was successful.

Signed-off-by: Ashwin Chaugule <ashwin.chaugule@...aro.org>
---
 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 17e9e4a..4acaddb 100644
--- a/drivers/mailbox/mailbox.c
+++ b/drivers/mailbox/mailbox.c
@@ -101,7 +101,7 @@ static void tx_tick(struct mbox_chan *chan, int r)
 	if (mssg && chan->cl->tx_done)
 		chan->cl->tx_done(chan->cl, mssg, r);
 
-	if (chan->cl->tx_block)
+	if ((!r) && chan->cl->tx_block)
 		complete(&chan->tx_complete);
 }
 
-- 
1.9.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/