Re: [PATCH 2/8] raw: Add missing annotations to raw_seq_start() and raw_seq_stop()

On Tue, 10 Mar 2020, Eric Dumazet wrote:

On 3/10/20 6:09 PM, Jules Irenge wrote:

quoted

Sparse reports warnings at raw_seq_start() and raw_seq_stop()

warning: context imbalance in raw_seq_start() - wrong count at exit
warning: context imbalance in raw_seq_stop() - unexpected unlock

The root cause is the missing annotations at raw_seq_start()
	and raw_seq_stop()
Add the missing __acquires(&h->lock) annotation
Add the missing __releases(&h->lock) annotation

Signed-off-by: Jules Irenge <redacted>
---
 net/ipv4/raw.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/ipv4/raw.c b/net/ipv4/raw.c
index 3183413ebc6c..47665919048f 100644
--- a/net/ipv4/raw.c
+++ b/net/ipv4/raw.c

@@ -1034,6 +1034,7 @@ static struct sock *raw_get_idx(struct seq_file *seq, loff_t pos)
 }
 
 void *raw_seq_start(struct seq_file *seq, loff_t *pos)
+	__acquires(&h->lock)

I dunno, h variable is not yet defined/declared at this point,
this looks weird.

quoted

 {
 	struct raw_hashinfo *h = PDE_DATA(file_inode(seq->file));
 

@@ -1056,6 +1057,7 @@ void *raw_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 EXPORT_SYMBOL_GPL(raw_seq_next);
 
 void raw_seq_stop(struct seq_file *seq, void *v)
+	__releases(&h->lock)
 {
 	struct raw_hashinfo *h = PDE_DATA(file_inode(seq->file));
 

Thanks for the feedback,

I think h is a pointer of type struct raw_hashinfo, in which member lock 
is initialized on line number 89. 

Kind regards