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authorJiri Kosina <jkosina@suse.cz>2007-03-28 18:12:34 +0200
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-03-28 13:58:02 -0700
commit4dfc896e90359df04c80da5ab08ec31e87846c43 (patch)
tree1d68ae9c2e07c87f7cbc2f4b5c10d98a6c60a874 /drivers/oprofile/event_buffer.c
parent6faee84b006af55bab9908741dd76916c8450be2 (diff)
downloadop-kernel-dev-4dfc896e90359df04c80da5ab08ec31e87846c43.zip
op-kernel-dev-4dfc896e90359df04c80da5ab08ec31e87846c43.tar.gz
[PATCH] oprofile: fix potential deadlock on oprofilefs_lock
nmi_cpu_setup() is called from hardirq context and acquires oprofilefs_lock. alloc_event_buffer() and oprofilefs_ulong_from_user() acquire this lock without disabling irqs, which could deadlock. Signed-off-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/oprofile/event_buffer.c')
-rw-r--r--drivers/oprofile/event_buffer.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/oprofile/event_buffer.c b/drivers/oprofile/event_buffer.c
index 00e937e..e7fbac5 100644
--- a/drivers/oprofile/event_buffer.c
+++ b/drivers/oprofile/event_buffer.c
@@ -70,11 +70,12 @@ void wake_up_buffer_waiter(void)
int alloc_event_buffer(void)
{
int err = -ENOMEM;
+ unsigned long flags;
- spin_lock(&oprofilefs_lock);
+ spin_lock_irqsave(&oprofilefs_lock, flags);
buffer_size = fs_buffer_size;
buffer_watershed = fs_buffer_watershed;
- spin_unlock(&oprofilefs_lock);
+ spin_unlock_irqrestore(&oprofilefs_lock, flags);
if (buffer_watershed >= buffer_size)
return -EINVAL;
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