* [PATCH 4/4] drivers/misc/sgi-xp/xpc_uv.c: convert nested spin_lock_irqsave to spin_lock
@ 2010-10-19 9:43 ` Julia Lawall
0 siblings, 0 replies; 4+ messages in thread
From: Julia Lawall @ 2010-10-19 9:43 UTC (permalink / raw)
To: Robin Holt; +Cc: kernel-janitors, linux-kernel
From: Julia Lawall <julia@diku.dk>
If spin_lock_irqsave is called twice in a row with the same second
argument, the interrupt state at the point of the second call overwrites
the value saved by the first call. Indeed, the second call does not need
to save the interrupt state, so it is changed to a simple spin_lock.
The semantic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@@
expression lock1,lock2;
expression flags;
@@
*spin_lock_irqsave(lock1,flags)
... when != flags
*spin_lock_irqsave(lock2,flags)
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
---
drivers/misc/sgi-xp/xpc_uv.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/misc/sgi-xp/xpc_uv.c b/drivers/misc/sgi-xp/xpc_uv.c
index 1f59ee2..7aeaef7 100644
--- a/drivers/misc/sgi-xp/xpc_uv.c
+++ b/drivers/misc/sgi-xp/xpc_uv.c
@@ -451,9 +451,9 @@ xpc_handle_activate_mq_msg_uv(struct xpc_partition *part,
if (msg->activate_gru_mq_desc_gpa ! part_uv->activate_gru_mq_desc_gpa) {
- spin_lock_irqsave(&part_uv->flags_lock, irq_flags);
+ spin_lock(&part_uv->flags_lock);
part_uv->flags &= ~XPC_P_CACHED_ACTIVATE_GRU_MQ_DESC_UV;
- spin_unlock_irqrestore(&part_uv->flags_lock, irq_flags);
+ spin_unlock(&part_uv->flags_lock);
part_uv->activate_gru_mq_desc_gpa msg->activate_gru_mq_desc_gpa;
}
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH 4/4] drivers/misc/sgi-xp/xpc_uv.c: convert nested spin_lock_irqsave to spin_lock
@ 2010-10-19 9:43 ` Julia Lawall
0 siblings, 0 replies; 4+ messages in thread
From: Julia Lawall @ 2010-10-19 9:43 UTC (permalink / raw)
To: Robin Holt; +Cc: kernel-janitors, linux-kernel
From: Julia Lawall <julia@diku.dk>
If spin_lock_irqsave is called twice in a row with the same second
argument, the interrupt state at the point of the second call overwrites
the value saved by the first call. Indeed, the second call does not need
to save the interrupt state, so it is changed to a simple spin_lock.
The semantic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@@
expression lock1,lock2;
expression flags;
@@
*spin_lock_irqsave(lock1,flags)
... when != flags
*spin_lock_irqsave(lock2,flags)
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
---
drivers/misc/sgi-xp/xpc_uv.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/misc/sgi-xp/xpc_uv.c b/drivers/misc/sgi-xp/xpc_uv.c
index 1f59ee2..7aeaef7 100644
--- a/drivers/misc/sgi-xp/xpc_uv.c
+++ b/drivers/misc/sgi-xp/xpc_uv.c
@@ -451,9 +451,9 @@ xpc_handle_activate_mq_msg_uv(struct xpc_partition *part,
if (msg->activate_gru_mq_desc_gpa !=
part_uv->activate_gru_mq_desc_gpa) {
- spin_lock_irqsave(&part_uv->flags_lock, irq_flags);
+ spin_lock(&part_uv->flags_lock);
part_uv->flags &= ~XPC_P_CACHED_ACTIVATE_GRU_MQ_DESC_UV;
- spin_unlock_irqrestore(&part_uv->flags_lock, irq_flags);
+ spin_unlock(&part_uv->flags_lock);
part_uv->activate_gru_mq_desc_gpa =
msg->activate_gru_mq_desc_gpa;
}
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH 4/4] drivers/misc/sgi-xp/xpc_uv.c: convert nested
2010-10-19 9:43 ` Julia Lawall
@ 2010-10-20 2:51 ` Robin Holt
-1 siblings, 0 replies; 4+ messages in thread
From: Robin Holt @ 2010-10-20 2:51 UTC (permalink / raw)
To: Julia Lawall; +Cc: Robin Holt, kernel-janitors, linux-kernel
On Tue, Oct 19, 2010 at 11:43:56AM +0200, Julia Lawall wrote:
> From: Julia Lawall <julia@diku.dk>
>
> If spin_lock_irqsave is called twice in a row with the same second
> argument, the interrupt state at the point of the second call overwrites
> the value saved by the first call. Indeed, the second call does not need
> to save the interrupt state, so it is changed to a simple spin_lock.
>
> The semantic match that finds this problem is as follows:
> (http://coccinelle.lip6.fr/)
>
> // <smpl>
> @@
> expression lock1,lock2;
> expression flags;
> @@
>
> *spin_lock_irqsave(lock1,flags)
> ... when != flags
> *spin_lock_irqsave(lock2,flags)
> // </smpl>
>
> Signed-off-by: Julia Lawall <julia@diku.dk>
Acked-by: Robin Holt <holt@sgi.com>
>
> ---
> drivers/misc/sgi-xp/xpc_uv.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/misc/sgi-xp/xpc_uv.c b/drivers/misc/sgi-xp/xpc_uv.c
> index 1f59ee2..7aeaef7 100644
> --- a/drivers/misc/sgi-xp/xpc_uv.c
> +++ b/drivers/misc/sgi-xp/xpc_uv.c
> @@ -451,9 +451,9 @@ xpc_handle_activate_mq_msg_uv(struct xpc_partition *part,
>
> if (msg->activate_gru_mq_desc_gpa !> part_uv->activate_gru_mq_desc_gpa) {
> - spin_lock_irqsave(&part_uv->flags_lock, irq_flags);
> + spin_lock(&part_uv->flags_lock);
> part_uv->flags &= ~XPC_P_CACHED_ACTIVATE_GRU_MQ_DESC_UV;
> - spin_unlock_irqrestore(&part_uv->flags_lock, irq_flags);
> + spin_unlock(&part_uv->flags_lock);
> part_uv->activate_gru_mq_desc_gpa > msg->activate_gru_mq_desc_gpa;
> }
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH 4/4] drivers/misc/sgi-xp/xpc_uv.c: convert nested spin_lock_irqsave to spin_lock
@ 2010-10-20 2:51 ` Robin Holt
0 siblings, 0 replies; 4+ messages in thread
From: Robin Holt @ 2010-10-20 2:51 UTC (permalink / raw)
To: Julia Lawall; +Cc: Robin Holt, kernel-janitors, linux-kernel
On Tue, Oct 19, 2010 at 11:43:56AM +0200, Julia Lawall wrote:
> From: Julia Lawall <julia@diku.dk>
>
> If spin_lock_irqsave is called twice in a row with the same second
> argument, the interrupt state at the point of the second call overwrites
> the value saved by the first call. Indeed, the second call does not need
> to save the interrupt state, so it is changed to a simple spin_lock.
>
> The semantic match that finds this problem is as follows:
> (http://coccinelle.lip6.fr/)
>
> // <smpl>
> @@
> expression lock1,lock2;
> expression flags;
> @@
>
> *spin_lock_irqsave(lock1,flags)
> ... when != flags
> *spin_lock_irqsave(lock2,flags)
> // </smpl>
>
> Signed-off-by: Julia Lawall <julia@diku.dk>
Acked-by: Robin Holt <holt@sgi.com>
>
> ---
> drivers/misc/sgi-xp/xpc_uv.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/misc/sgi-xp/xpc_uv.c b/drivers/misc/sgi-xp/xpc_uv.c
> index 1f59ee2..7aeaef7 100644
> --- a/drivers/misc/sgi-xp/xpc_uv.c
> +++ b/drivers/misc/sgi-xp/xpc_uv.c
> @@ -451,9 +451,9 @@ xpc_handle_activate_mq_msg_uv(struct xpc_partition *part,
>
> if (msg->activate_gru_mq_desc_gpa !=
> part_uv->activate_gru_mq_desc_gpa) {
> - spin_lock_irqsave(&part_uv->flags_lock, irq_flags);
> + spin_lock(&part_uv->flags_lock);
> part_uv->flags &= ~XPC_P_CACHED_ACTIVATE_GRU_MQ_DESC_UV;
> - spin_unlock_irqrestore(&part_uv->flags_lock, irq_flags);
> + spin_unlock(&part_uv->flags_lock);
> part_uv->activate_gru_mq_desc_gpa =
> msg->activate_gru_mq_desc_gpa;
> }
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2010-10-20 2:51 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2010-10-19 9:43 [PATCH 4/4] drivers/misc/sgi-xp/xpc_uv.c: convert nested spin_lock_irqsave to spin_lock Julia Lawall
2010-10-19 9:43 ` Julia Lawall
2010-10-20 2:51 ` [PATCH 4/4] drivers/misc/sgi-xp/xpc_uv.c: convert nested Robin Holt
2010-10-20 2:51 ` [PATCH 4/4] drivers/misc/sgi-xp/xpc_uv.c: convert nested spin_lock_irqsave to spin_lock Robin Holt
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