* [PATCH] irda: Fix RCU lock pairing on error path
@ 2006-06-29 0:56 Josh Triplett
2006-06-29 14:27 ` Paul E. McKenney
2006-06-29 19:48 ` [PATCH] irda: " David Miller
0 siblings, 2 replies; 6+ messages in thread
From: Josh Triplett @ 2006-06-29 0:56 UTC (permalink / raw)
To: linux-kernel; +Cc: Paul McKenney, Dipkanar Sarma, Andrew Morton, Samuel Ortiz
irlan_client_discovery_indication calls rcu_read_lock and rcu_read_unlock, but
returns without unlocking in an error case. Fix that by replacing the return
with a goto so that the rcu_read_unlock always gets executed.
Signed-off-by: Josh Triplett <josh@freedesktop.org>
---
net/irda/irlan/irlan_client.c | 3 ++-
1 files changed, 2 insertions(+), 1 deletions(-)
e20ab96944814489277c3bfd4e69133854ab01e9
diff --git a/net/irda/irlan/irlan_client.c b/net/irda/irlan/irlan_client.c
index f8e6cb0..5ce7d2e 100644
--- a/net/irda/irlan/irlan_client.c
+++ b/net/irda/irlan/irlan_client.c
@@ -173,13 +173,14 @@ void irlan_client_discovery_indication(d
rcu_read_lock();
self = irlan_get_any();
if (self) {
- IRDA_ASSERT(self->magic == IRLAN_MAGIC, return;);
+ IRDA_ASSERT(self->magic == IRLAN_MAGIC, goto out;);
IRDA_DEBUG(1, "%s(), Found instance (%08x)!\n", __FUNCTION__ ,
daddr);
irlan_client_wakeup(self, saddr, daddr);
}
+out:
rcu_read_unlock();
}
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH] irda: Fix RCU lock pairing on error path
2006-06-29 0:56 [PATCH] irda: Fix RCU lock pairing on error path Josh Triplett
@ 2006-06-29 14:27 ` Paul E. McKenney
2006-06-29 14:59 ` Samuel Ortiz
2006-06-30 6:55 ` [PATCH 1/2] [IrDA] " Samuel Ortiz
2006-06-29 19:48 ` [PATCH] irda: " David Miller
1 sibling, 2 replies; 6+ messages in thread
From: Paul E. McKenney @ 2006-06-29 14:27 UTC (permalink / raw)
To: Josh Triplett; +Cc: linux-kernel, Dipkanar Sarma, Andrew Morton, Samuel Ortiz
On Wed, Jun 28, 2006 at 05:56:41PM -0700, Josh Triplett wrote:
> irlan_client_discovery_indication calls rcu_read_lock and rcu_read_unlock, but
> returns without unlocking in an error case. Fix that by replacing the return
> with a goto so that the rcu_read_unlock always gets executed.
Good catch!!! Looks good from an RCU viewpoint, in fact, looks absolutely
necessary to permit IRDA to work in debug mode, particularly in either
a CONFIG_PREEMPT or a -rt kernel.
One question below, but up to the maintainer. ;-)
Thanx, Paul
Acked-by: Paul E. McKenney <paulmck@us.ibm.com>
> Signed-off-by: Josh Triplett <josh@freedesktop.org>
>
> ---
>
> net/irda/irlan/irlan_client.c | 3 ++-
> 1 files changed, 2 insertions(+), 1 deletions(-)
>
> e20ab96944814489277c3bfd4e69133854ab01e9
> diff --git a/net/irda/irlan/irlan_client.c b/net/irda/irlan/irlan_client.c
> index f8e6cb0..5ce7d2e 100644
> --- a/net/irda/irlan/irlan_client.c
> +++ b/net/irda/irlan/irlan_client.c
> @@ -173,13 +173,14 @@ void irlan_client_discovery_indication(d
> rcu_read_lock();
> self = irlan_get_any();
> if (self) {
> - IRDA_ASSERT(self->magic == IRLAN_MAGIC, return;);
> + IRDA_ASSERT(self->magic == IRLAN_MAGIC, goto out;);
>
> IRDA_DEBUG(1, "%s(), Found instance (%08x)!\n", __FUNCTION__ ,
> daddr);
>
> irlan_client_wakeup(self, saddr, daddr);
> }
> +out:
Should the above label instead be as follows?
IRDA_ASSERT_LABEL(out:)
Just in case some variant of gcc, sparse, or whatever complains about
labels that don't have a corresponding goto (in CONFIG_IRDA_DEBUG=n
builds).
> rcu_read_unlock();
> }
>
>
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] irda: Fix RCU lock pairing on error path
2006-06-29 14:27 ` Paul E. McKenney
@ 2006-06-29 14:59 ` Samuel Ortiz
2006-06-30 6:55 ` [PATCH 1/2] [IrDA] " Samuel Ortiz
1 sibling, 0 replies; 6+ messages in thread
From: Samuel Ortiz @ 2006-06-29 14:59 UTC (permalink / raw)
To: paulmck, Josh Triplett
Cc: linux-kernel, Dipkanar Sarma, Andrew Morton, Samuel Ortiz
Hi Paul, hi Josh,
Paul E. McKenney wrote :
> On Wed, Jun 28, 2006 at 05:56:41PM -0700, Josh Triplett wrote:
>> irlan_client_discovery_indication calls rcu_read_lock and
>> rcu_read_unlock, but
>> returns without unlocking in an error case. Fix that by replacing the
>> return
>> with a goto so that the rcu_read_unlock always gets executed.
>
> Good catch!!! Looks good from an RCU viewpoint, in fact, looks absolutely
> necessary to permit IRDA to work in debug mode, particularly in either
> a CONFIG_PREEMPT or a -rt kernel.
Indeed, nice catch.
> One question below, but up to the maintainer. ;-)
Yes, definitely, IRDA_ASSERT_LABEL(out:) makes sense.
I will forward the patch to davem's netdev tree, thanks.
Cheers,
Samuel.
> Thanx, Paul
>
> Acked-by: Paul E. McKenney <paulmck@us.ibm.com>
>> Signed-off-by: Josh Triplett <josh@freedesktop.org>
>>
>> ---
>>
>> net/irda/irlan/irlan_client.c | 3 ++-
>> 1 files changed, 2 insertions(+), 1 deletions(-)
>>
>> e20ab96944814489277c3bfd4e69133854ab01e9
>> diff --git a/net/irda/irlan/irlan_client.c
>> b/net/irda/irlan/irlan_client.c
>> index f8e6cb0..5ce7d2e 100644
>> --- a/net/irda/irlan/irlan_client.c
>> +++ b/net/irda/irlan/irlan_client.c
>> @@ -173,13 +173,14 @@ void irlan_client_discovery_indication(d
>> rcu_read_lock();
>> self = irlan_get_any();
>> if (self) {
>> - IRDA_ASSERT(self->magic == IRLAN_MAGIC, return;);
>> + IRDA_ASSERT(self->magic == IRLAN_MAGIC, goto out;);
>>
>> IRDA_DEBUG(1, "%s(), Found instance (%08x)!\n", __FUNCTION__ ,
>> daddr);
>>
>> irlan_client_wakeup(self, saddr, daddr);
>> }
>> +out:
>
> Should the above label instead be as follows?
>
> IRDA_ASSERT_LABEL(out:)
>
> Just in case some variant of gcc, sparse, or whatever complains about
> labels that don't have a corresponding goto (in CONFIG_IRDA_DEBUG=n
> builds).
>
>> rcu_read_unlock();
>> }
>>
>>
>>
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] irda: Fix RCU lock pairing on error path
2006-06-29 0:56 [PATCH] irda: Fix RCU lock pairing on error path Josh Triplett
2006-06-29 14:27 ` Paul E. McKenney
@ 2006-06-29 19:48 ` David Miller
1 sibling, 0 replies; 6+ messages in thread
From: David Miller @ 2006-06-29 19:48 UTC (permalink / raw)
To: josht; +Cc: linux-kernel, paulmck, dipankar, akpm, samuel
From: Josh Triplett <josht@vnet.ibm.com>
Date: Wed, 28 Jun 2006 17:56:41 -0700
> irlan_client_discovery_indication calls rcu_read_lock and rcu_read_unlock, but
> returns without unlocking in an error case. Fix that by replacing the return
> with a goto so that the rcu_read_unlock always gets executed.
>
> Signed-off-by: Josh Triplett <josh@freedesktop.org>
Applied, thanks a lot.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 1/2] [IrDA] Fix RCU lock pairing on error path
2006-06-30 6:55 ` [PATCH 1/2] [IrDA] " Samuel Ortiz
@ 2006-06-30 0:02 ` David Miller
0 siblings, 0 replies; 6+ messages in thread
From: David Miller @ 2006-06-30 0:02 UTC (permalink / raw)
To: samuel; +Cc: paulmck, josht, linux-kernel, dipankar, akpm, netdev, irda-users
From: Samuel Ortiz <samuel@sortiz.org>
Date: Fri, 30 Jun 2006 09:55:34 +0300
> irlan_client_discovery_indication calls rcu_read_lock and rcu_read_unlock, but
> returns without unlocking in an error case. Fix that by replacing the return
> with a goto so that the rcu_read_unlock always gets executed.
>
> Signed-off-by: Josh Triplett <josh@freedesktop.org>
> Acked-by: Paul E. McKenney <paulmck@us.ibm.com>
> Signed-off-by: Samuel Ortiz samuel@sortiz.org <>
Applied, thanks.
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH 1/2] [IrDA] Fix RCU lock pairing on error path
2006-06-29 14:27 ` Paul E. McKenney
2006-06-29 14:59 ` Samuel Ortiz
@ 2006-06-30 6:55 ` Samuel Ortiz
2006-06-30 0:02 ` David Miller
1 sibling, 1 reply; 6+ messages in thread
From: Samuel Ortiz @ 2006-06-30 6:55 UTC (permalink / raw)
To: Paul E. McKenney, David S. Miller, Josh Triplett
Cc: linux-kernel, Dipkanar Sarma, Andrew Morton, netdev, irda-users
Hi Dave,
irlan_client_discovery_indication calls rcu_read_lock and rcu_read_unlock, but
returns without unlocking in an error case. Fix that by replacing the return
with a goto so that the rcu_read_unlock always gets executed.
Signed-off-by: Josh Triplett <josh@freedesktop.org>
Acked-by: Paul E. McKenney <paulmck@us.ibm.com>
Signed-off-by: Samuel Ortiz samuel@sortiz.org <>
---
net/irda/irlan/irlan_client.c | 3 ++-
1 files changed, 2 insertions(+), 1 deletions(-)
diff --git a/net/irda/irlan/irlan_client.c b/net/irda/irlan/irlan_client.c
index f8e6cb0..95cf123 100644
--- a/net/irda/irlan/irlan_client.c
+++ b/net/irda/irlan/irlan_client.c
@@ -173,13 +173,14 @@ void irlan_client_discovery_indication(d
rcu_read_lock();
self = irlan_get_any();
if (self) {
- IRDA_ASSERT(self->magic == IRLAN_MAGIC, return;);
+ IRDA_ASSERT(self->magic == IRLAN_MAGIC, goto out;);
IRDA_DEBUG(1, "%s(), Found instance (%08x)!\n", __FUNCTION__ ,
daddr);
irlan_client_wakeup(self, saddr, daddr);
}
+IRDA_ASSERT_LABEL(out:)
rcu_read_unlock();
}
--
1.4.0
^ permalink raw reply related [flat|nested] 6+ messages in thread
end of thread, other threads:[~2006-06-30 0:02 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
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2006-06-29 0:56 [PATCH] irda: Fix RCU lock pairing on error path Josh Triplett
2006-06-29 14:27 ` Paul E. McKenney
2006-06-29 14:59 ` Samuel Ortiz
2006-06-30 6:55 ` [PATCH 1/2] [IrDA] " Samuel Ortiz
2006-06-30 0:02 ` David Miller
2006-06-29 19:48 ` [PATCH] irda: " David Miller
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