2020-03-11 01:10:19

by Jules Irenge

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

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 <[email protected]>
---
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)
{
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));

--
2.24.1

2020-03-11 01:15:47

by Eric Dumazet

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

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 <[email protected]>
> ---
> 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));
>
>

2020-03-11 01:42:17

by Jules Irenge

Subject: 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:
> > 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 <[email protected]>
> > ---
> > 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

2020-03-12 06:20:41

by David Miller

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

From: Jules Irenge <[email protected]>
Date: Wed, 11 Mar 2020 01:09:02 +0000

> 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 <[email protected]>

Applied.