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

[Jules Irenge]

On Tue, 10 Mar 2020, Eric Dumazet wrote:

> 
> 
> 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));
> >  
> > 
> 
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