fix oops on cat /dev/snapshot

fix oops on cat /dev/snapshot

[Pavel Machek]

What /dev/snapshot is simply cat-ed -- without ioctls used in normal
operation -- it oopses. This one should fix it.

Signed-off-by: Pavel Machek <pavel@suse.cz>

--- clean-mm/kernel/power/user.c	2007-06-09 16:18:12.000000000 +0200
+++ linux-mm/kernel/power/user.c	2007-06-11 14:06:19.000000000 +0200
@@ -99,6 +99,8 @@
 	ssize_t res;
 
 	data = filp->private_data;
+	if (!data->ready)
+		return -EINVAL;
 	res = snapshot_read_next(&data->handle, count);
 	if (res > 0) {
 		if (copy_to_user(buf, data_of(data->handle), res))

-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

Re: fix oops on cat /dev/snapshot

[Pavel Machek]

Hi!

> > What /dev/snapshot is simply cat-ed -- without ioctls used in normal
> > operation -- it oopses. This one should fix it.
> > 
> > Signed-off-by: Pavel Machek <pavel@suse.cz>
> > 
> > --- clean-mm/kernel/power/user.c	2007-06-09 16:18:12.000000000 +0200
> > +++ linux-mm/kernel/power/user.c	2007-06-11 14:06:19.000000000 +0200
> > @@ -99,6 +99,8 @@
> >  	ssize_t res;
> >  
> >  	data = filp->private_data;
> > +	if (!data->ready)
> > +		return -EINVAL;
> 
> I'd like to use -ENODATA here.
> 
> >  	res = snapshot_read_next(&data->handle, count);
> >  	if (res > 0) {
> >  		if (copy_to_user(buf, data_of(data->handle), res))
> > 
> 
> I have a patch for that and I'm going to post it in a while if you don't
> mind.
> 
> I've already posted it once, here: http://lkml.org/lkml/2007/6/10/146

Aha, go ahead, I did not notice that mail.
										Pavel

-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

Re: fix oops on cat /dev/snapshot

[Rafael J. Wysocki]

On Monday, 11 June 2007 14:17, Pavel Machek wrote:
> What /dev/snapshot is simply cat-ed -- without ioctls used in normal
> operation -- it oopses. This one should fix it.
> 
> Signed-off-by: Pavel Machek <pavel@suse.cz>
> 
> --- clean-mm/kernel/power/user.c	2007-06-09 16:18:12.000000000 +0200
> +++ linux-mm/kernel/power/user.c	2007-06-11 14:06:19.000000000 +0200
> @@ -99,6 +99,8 @@
>  	ssize_t res;
>  
>  	data = filp->private_data;
> +	if (!data->ready)
> +		return -EINVAL;

I'd like to use -ENODATA here.

>  	res = snapshot_read_next(&data->handle, count);
>  	if (res > 0) {
>  		if (copy_to_user(buf, data_of(data->handle), res))
> 

I have a patch for that and I'm going to post it in a while if you don't
mind.

I've already posted it once, here: http://lkml.org/lkml/2007/6/10/146

Greetings,
Rafael


-- 
"Premature optimization is the root of all evil." - Donald Knuth