* [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
* [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
* 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
* 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
end of thread, other threads:[~2006-06-30 0:02 UTC | newest] Thread overview: 6+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 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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