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

From: Eric Dumazet
Date: Tue Mar 10 2020 - 21:15:19 EST




On 3/10/20 6:09 PM, Jules Irenge wrote:
> 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 <jbi.octave@xxxxxxxxx>
> ---
> 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.

> {
> 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));
>
>