From: "Bu, Yitian" <ybu@qti.qualcomm.com>
To: "tglx@linutronix.de" <tglx@linutronix.de>,
"a.p.zijlstra@chello.nl" <a.p.zijlstra@chello.nl>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"mingo@kernel.org" <mingo@kernel.org>
Subject: [PATCH] Fix rq->lock vs logbuf_lock unlock race
Date: Mon, 18 Feb 2013 12:53:37 +0000 [thread overview]
Message-ID: <E807E903FE6CBE4D95E420FBFCC273B827413C@nasanexd01h.na.qualcomm.com> (raw)
This patch is for kernel V3.7.9
>From 8796f4a2175a323aaa49ea8dd0fe68678dd5dccd Mon Sep 17 00:00:00 2001
From: ybu <ybu@qti.qualcomm.com>
Date: Mon, 18 Feb 2013 19:52:01 +0800
Subject: [PATCH] Fix rq->lock vs logbuf_lock unlock race
fix up the fallout from commit 07354eb1a74d1 ("locking printk:
Annotate logbuf_lock as raw")
Release console_sem after unlocking the logbuf_lock avoids some lock
inversion troubles between logbuf_lock and rq->lock.
Change-Id: I782c1d16e0e82bd156699f0f205f19781c4819e0
Signed-off-by: ybu <ybu@qti.qualcomm.com>
---
kernel/printk.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/printk.c b/kernel/printk.c
index f8e0b5a..3a49454 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -1356,9 +1356,9 @@ static int console_trylock_for_printk(unsigned int cpu)
}
}
logbuf_cpu = UINT_MAX;
+ raw_spin_unlock(&logbuf_lock);
if (wake)
up(&console_sem);
- raw_spin_unlock(&logbuf_lock);
return retval;
}
--
1.7.9.5
next reply other threads:[~2013-02-18 12:53 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-18 12:53 Bu, Yitian [this message]
2013-02-18 14:17 ` [tip:core/printk] printk: Fix rq-> lock vs logbuf_lock unlock lock inversion tip-bot for Bu, Yitian
2013-02-20 8:45 ` [PATCH] Fix rq->lock vs logbuf_lock unlock race Peter Zijlstra
2013-02-20 9:38 ` Bu, Yitian
2013-02-20 10:19 ` Peter Zijlstra
2013-02-20 11:24 ` Bu, Yitian
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=E807E903FE6CBE4D95E420FBFCC273B827413C@nasanexd01h.na.qualcomm.com \
--to=ybu@qti.qualcomm.com \
--cc=a.p.zijlstra@chello.nl \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@kernel.org \
--cc=tglx@linutronix.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).