Re: [PATCH v2 1/4] staging: android: Replace BUG_ON with WARN_ON

[Tomer Samara]

On Tue, Aug 18, 2020 at 04:11:06PM +0200, Greg Kroah-Hartman wrote:
> On Sun, Aug 16, 2020 at 10:23:25PM +0300, Tomer Samara wrote:
> > BUG_ON() is replaced with WARN_ON at ion_page_pool.c
> 
> Why?
> 
> > Fixes the following issue:
> > Avoid crashing the kernel - try using WARN_ON & recovery code ratherthan BUG() or BUG_ON().
> 
> Ideally you can get rid of WARN_ON() too, right?
> 
> Many systems run in panic-on-warn mode, so this really does not change
> anything.  Try fixing this up properly to not crash at all.
> 
You mean by that to just remove the WARN_ON and leave the condition the
same?

> > 
> > Signed-off-by: Tomer Samara <tomersamara98@xxxxxxxxx>
> > ---
> >  drivers/staging/android/ion/ion_page_pool.c | 12 ++++++++----
> >  1 file changed, 8 insertions(+), 4 deletions(-)
> > 
> > diff --git a/drivers/staging/android/ion/ion_page_pool.c b/drivers/staging/android/ion/ion_page_pool.c
> > index 0198b886d906..c1b9eda35c96 100644
> > --- a/drivers/staging/android/ion/ion_page_pool.c
> > +++ b/drivers/staging/android/ion/ion_page_pool.c
> > @@ -46,11 +46,13 @@ static struct page *ion_page_pool_remove(struct ion_page_pool *pool, bool high)
> >  	struct page *page;
> >  
> >  	if (high) {
> > -		BUG_ON(!pool->high_count);
> > +		if (WARN_ON(!pool->high_count))
> > +			return NULL;
> 
> And can you test this that it works properly?
> 
> thanks,
> 
> greg k-h

Will do :)