[PATCH 2/6] udp: Add missing annotations for busylock_acquire() and busylock_release()

[PATCH 2/6] udp: Add missing annotations for busylock_acquire() and busylock_release()

[Jules Irenge]

Sparse reports warnings

warning: context imbalance in busylock_acquire() - wrong count at exit
warning: context imbalance in busylock_release() - unexpected unlock

The root cause is the missing annotations at
busylock_acquire() and busylock_release()

The __release(busy) annotation inside busylock_release()
tells Sparse and not GCC to shutdown the warning
in case the condition is not satisfied.

Add the missing __acquires(busy) annotation
Add the missing __releases(busy) annotation
Add the __release(busy) annotation

Signed-off-by: Jules Irenge <jbi.octave@gmail.com>
---
 net/ipv4/udp.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index db76b9609299..5ca12a945ac3 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1430,6 +1430,7 @@ static int udp_busylocks_log __read_mostly;
 static spinlock_t *udp_busylocks __read_mostly;
 
 static spinlock_t *busylock_acquire(void *ptr)
+	__acquires(busy)
 {
 	spinlock_t *busy;
 
@@ -1439,9 +1440,13 @@ static spinlock_t *busylock_acquire(void *ptr)
 }
 
 static void busylock_release(spinlock_t *busy)
+	__releases(busy)
 {
 	if (busy)
 		spin_unlock(busy);
+	else
+		/* annotation for sparse */
+		__release(busy);
 }
 
 int __udp_enqueue_schedule_skb(struct sock *sk, struct sk_buff *skb)
-- 
2.25.3

[PATCH 3/6] udp: Add annotations for udp_rmem_release()

[Jules Irenge]

Sparse reports a warning

 warning: context imbalance in udp_rmem_release() - unexpected unlock

To fix this,
__acquire(&sk_queue->lock) and __release(&sk_queue->lock) annotations
are added in case the condition is not met.

This add basically tell Sparse and not GCC to shutdown the warning

Add __acquire(&sk_queue->lock) annotation
Add the __release(&sk_queue->lock) annotation

Signed-off-by: Jules Irenge <jbi.octave@gmail.com>
---
 net/ipv4/udp.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 5ca12a945ac3..175bd14bfac8 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1382,6 +1382,9 @@ static void udp_rmem_release(struct sock *sk, int size, int partial,
 	sk_queue = &sk->sk_receive_queue;
 	if (!rx_queue_lock_held)
 		spin_lock(&sk_queue->lock);
+	else
+		/* annotation for sparse */
+		__acquire(&sk_queue->lock);
 
 
 	sk->sk_forward_alloc += size;
@@ -1398,6 +1401,9 @@ static void udp_rmem_release(struct sock *sk, int size, int partial,
 
 	if (!rx_queue_lock_held)
 		spin_unlock(&sk_queue->lock);
+	else
+		/* annotation for sparse */
+		__release(&sk_queue->lock);
 }
 
 /* Note: called with reader_queue.lock held.
-- 
2.25.3

[PATCH 4/6] net: atm: Add missing annotation for lec_seq_stop()

[Jules Irenge]

Sparse reports a warning at lec_seq_stop()
warning: context imbalance in lec_seq_stop() - unexpected unlock

The root cause is the missing annotation at lec_seq_stop()
The __release() annotation inside lec_seq_stop()
tells only Sparse to shutdown the warning

Add the missing __releases(&state->locked->lec_arp_lock)
Add   __release(&state->locked->lec_arp_lock) annotation

Signed-off-by: Jules Irenge <jbi.octave@gmail.com>
---
 net/atm/lec.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/net/atm/lec.c b/net/atm/lec.c
index 25fa3a7b72bd..22415bc11878 100644
--- a/net/atm/lec.c
+++ b/net/atm/lec.c
@@ -940,6 +940,7 @@ static void *lec_seq_start(struct seq_file *seq, loff_t *pos)
 }
 
 static void lec_seq_stop(struct seq_file *seq, void *v)
+	__releases(&state->locked->lec_arp_lock)
 {
 	struct lec_state *state = seq->private;
 
@@ -947,7 +948,9 @@ static void lec_seq_stop(struct seq_file *seq, void *v)
 		spin_unlock_irqrestore(&state->locked->lec_arp_lock,
 				       state->flags);
 		dev_put(state->dev);
-	}
+	} else
+		/* annotation for sparse */
+		__release(&state->locked->lec_arp_lock);
 }
 
 static void *lec_seq_next(struct seq_file *seq, void *v, loff_t *pos)
-- 
2.25.3

[PATCH 6/6] net: atm: Add annotation for lec_priv_walk()

[Jules Irenge]

Sparse reports a warning at lec_priv_walk()
warning: context imbalance in lec_priv_walk() - unexpected unlock

The root cause is the missing annotation at lec_priv_walk()
To fix this, __acquire() and __release() annotations
are added in case conditions are not met.
This only instruct  Sparse to shutdown the warning

Add the  __acquire(&priv->lec_arp_lock)
Add __release(&priv->lec_arp_lock) annotation

Signed-off-by: Jules Irenge <jbi.octave@gmail.com>
---
 net/atm/lec.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/net/atm/lec.c b/net/atm/lec.c
index 22415bc11878..6070acaa3d5c 100644
--- a/net/atm/lec.c
+++ b/net/atm/lec.c
@@ -886,12 +886,18 @@ static void *lec_priv_walk(struct lec_state *state, loff_t *l,
 	if (!state->locked) {
 		state->locked = priv;
 		spin_lock_irqsave(&priv->lec_arp_lock, state->flags);
+	} else {
+		/* annotation for sparse */
+		__acquire(&priv->lec_arp_lock);
 	}
 	if (!lec_arp_walk(state, l, priv) && !lec_misc_walk(state, l, priv)) {
 		spin_unlock_irqrestore(&priv->lec_arp_lock, state->flags);
 		state->locked = NULL;
 		/* Partial state reset for the next time we get called */
 		state->arp_table = state->misc_table = 0;
+	} else {
+		/* annotation for sparse */
+		__release(&priv->lec_arp_lock);
 	}
 	return state->locked;
 }
-- 
2.25.3

Re: [PATCH 6/6] net: atm: Add annotation for lec_priv_walk()

[Andy Shevchenko]

On Wed, Apr 29, 2020 at 11:05:28AM +0100, Jules Irenge wrote:
> Sparse reports a warning at lec_priv_walk()
> warning: context imbalance in lec_priv_walk() - unexpected unlock
> 
> The root cause is the missing annotation at lec_priv_walk()
> To fix this, __acquire() and __release() annotations
> are added in case conditions are not met.
> This only instruct  Sparse to shutdown the warning
> 
> Add the  __acquire(&priv->lec_arp_lock)
> Add __release(&priv->lec_arp_lock) annotation

At least those two I got should be in one patch. Simple fix all same sparse
issues at once.

-- 
With Best Regards,
Andy Shevchenko

[PATCH v2] net: atm: Add annotation for lec_priv_walk() and lec_seq_stop()

[Jules Irenge]

Sparse reports a warning at lec_priv_walk() and lec_seq_stop()

warning: context imbalance in lec_priv_walk() - unexpected unlock
warning: context imbalance in lec_seq_stop() - unexpected unlock

The root cause is the missing annotation at lec_priv_walk()
	and lec_seq_stop()
To fix this, __acquire() and __release() annotations
are added in case conditions are not met.
This only instruct Sparse to shutdown the warning

Add the  __acquire(&priv->lec_arp_lock)
Add __release(&priv->lec_arp_lock) annotation
Add __releases(&state->locked->lec_arp_lock) annotation
Add  __release(&state->locked->lec_arp_lock) annotation

Signed-off-by: Jules Irenge <jbi.octave@gmail.com>
---
Changes since v2 
- merge patch No 6 and No 4 into one

 net/atm/lec.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/net/atm/lec.c b/net/atm/lec.c
index 25fa3a7b72bd..7947abb17af2 100644
--- a/net/atm/lec.c
+++ b/net/atm/lec.c
@@ -886,12 +886,18 @@ static void *lec_priv_walk(struct lec_state *state, loff_t *l,
 	if (!state->locked) {
 		state->locked = priv;
 		spin_lock_irqsave(&priv->lec_arp_lock, state->flags);
+	} else {
+		/* annotation for sparse */
+		__acquire(&priv->lec_arp_lock);
 	}
 	if (!lec_arp_walk(state, l, priv) && !lec_misc_walk(state, l, priv)) {
 		spin_unlock_irqrestore(&priv->lec_arp_lock, state->flags);
 		state->locked = NULL;
 		/* Partial state reset for the next time we get called */
 		state->arp_table = state->misc_table = 0;
+	} else {
+		/* annotation for sparse */
+		__release(&priv->lec_arp_lock);
 	}
 	return state->locked;
 }
@@ -940,6 +946,7 @@ static void *lec_seq_start(struct seq_file *seq, loff_t *pos)
 }
 
 static void lec_seq_stop(struct seq_file *seq, void *v)
+	__releases(&state->locked->lec_arp_lock)
 {
 	struct lec_state *state = seq->private;
 
@@ -947,6 +954,9 @@ static void lec_seq_stop(struct seq_file *seq, void *v)
 		spin_unlock_irqrestore(&state->locked->lec_arp_lock,
 				       state->flags);
 		dev_put(state->dev);
+	} else {
+		/* annotation for sparse */
+		__release(&state->locked->lec_arp_lock);
 	}
 }
 
-- 
2.25.3