* [PATCH RT 3/7] printk: Fix rq->lock vs logbuf_lock unlock lock inversion
[not found] <20130219035339.428477998@goodmis.org>
@ 2013-02-19 3:53 ` Steven Rostedt
0 siblings, 0 replies; 2+ messages in thread
From: Steven Rostedt @ 2013-02-19 3:53 UTC (permalink / raw)
To: linux-kernel, linux-rt-users
Cc: Thomas Gleixner, Carsten Emde, John Kacur, ybu, Peter Zijlstra,
stable, stable-rt
[-- Attachment #1: 0003-printk-Fix-rq-lock-vs-logbuf_lock-unlock-lock-invers.patch --]
[-- Type: text/plain, Size: 1219 bytes --]
From: "Bu, Yitian" <ybu@qti.qualcomm.com>
commit 07354eb1a74d1 ("locking printk: Annotate logbuf_lock as raw")
reintroduced a lock inversion problem which was fixed in commit
0b5e1c5255 ("printk: Release console_sem after logbuf_lock"). This
happened probably when fixing up patch rejects.
Restore the ordering and unlock logbuf_lock before releasing
console_sem.
Signed-off-by: ybu <ybu@qti.qualcomm.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: stable@vger.kernel.org
Cc: stable-rt@vger.kernel.org
Link: http://lkml.kernel.org/r/E807E903FE6CBE4D95E420FBFCC273B827413C@nasanexd01h.na.qualcomm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
kernel/printk.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/printk.c b/kernel/printk.c
index 7109711..56d7497 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -868,9 +868,9 @@ static int console_trylock_for_printk(unsigned int cpu, unsigned long flags)
}
}
printk_cpu = UINT_MAX;
+ raw_spin_unlock(&logbuf_lock);
if (wake)
up(&console_sem);
- raw_spin_unlock(&logbuf_lock);
return retval;
}
static const char recursion_bug_msg [] =
--
1.7.10.4
^ permalink raw reply related [flat|nested] 2+ messages in thread
* [PATCH RT 3/7] printk: Fix rq->lock vs logbuf_lock unlock lock inversion
[not found] <20130219035623.277664914@goodmis.org>
@ 2013-02-19 3:56 ` Steven Rostedt
0 siblings, 0 replies; 2+ messages in thread
From: Steven Rostedt @ 2013-02-19 3:56 UTC (permalink / raw)
To: linux-kernel, linux-rt-users
Cc: Thomas Gleixner, Carsten Emde, John Kacur, ybu, Peter Zijlstra,
stable, stable-rt
[-- Attachment #1: 0003-printk-Fix-rq-lock-vs-logbuf_lock-unlock-lock-invers.patch --]
[-- Type: text/plain, Size: 1219 bytes --]
From: "Bu, Yitian" <ybu@qti.qualcomm.com>
commit 07354eb1a74d1 ("locking printk: Annotate logbuf_lock as raw")
reintroduced a lock inversion problem which was fixed in commit
0b5e1c5255 ("printk: Release console_sem after logbuf_lock"). This
happened probably when fixing up patch rejects.
Restore the ordering and unlock logbuf_lock before releasing
console_sem.
Signed-off-by: ybu <ybu@qti.qualcomm.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: stable@vger.kernel.org
Cc: stable-rt@vger.kernel.org
Link: http://lkml.kernel.org/r/E807E903FE6CBE4D95E420FBFCC273B827413C@nasanexd01h.na.qualcomm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
kernel/printk.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/printk.c b/kernel/printk.c
index 972cc56..37b9b99 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -867,9 +867,9 @@ static int console_trylock_for_printk(unsigned int cpu, unsigned long flags)
}
}
printk_cpu = UINT_MAX;
+ raw_spin_unlock(&logbuf_lock);
if (wake)
up(&console_sem);
- raw_spin_unlock(&logbuf_lock);
return retval;
}
static const char recursion_bug_msg [] =
--
1.7.10.4
^ permalink raw reply related [flat|nested] 2+ messages in thread
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2013-02-19 3:53 ` [PATCH RT 3/7] printk: Fix rq->lock vs logbuf_lock unlock lock inversion Steven Rostedt
[not found] <20130219035623.277664914@goodmis.org>
2013-02-19 3:56 ` Steven Rostedt
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