Re: [PATCH v4 2/2] staging: android: Remove BUG from ion_system_heap.c

[Dan Carpenter]

On Mon, Aug 24, 2020 at 02:24:57PM +0300, Dan Carpenter wrote:
> On Fri, Aug 21, 2020 at 09:25:26AM -0700, Randy Dunlap wrote:
> > On 8/21/20 8:28 AM, Tomer Samara wrote:
> > > Remove BUG() from ion_sytem_heap.c
> > > 
> > > this fix the following checkpatch issue:
> > > Avoid crashing the kernel - try using WARN_ON &
> > > recovery code ratherthan BUG() or BUG_ON().
> > > 
> > > Signed-off-by: Tomer Samara <tomersamara98@xxxxxxxxx>
> > > ---
> > >  drivers/staging/android/ion/ion_system_heap.c | 2 +-
> > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > > 
> > > diff --git a/drivers/staging/android/ion/ion_system_heap.c b/drivers/staging/android/ion/ion_system_heap.c
> > > index eac0632ab4e8..00d6154aec34 100644
> > > --- a/drivers/staging/android/ion/ion_system_heap.c
> > > +++ b/drivers/staging/android/ion/ion_system_heap.c
> > > @@ -30,7 +30,7 @@ static int order_to_index(unsigned int order)
> > >  	for (i = 0; i < NUM_ORDERS; i++)
> > >  		if (order == orders[i])
> > >  			return i;
> > > -	BUG();
> > > +	/* This is impossible. */
> > >  	return -1;
> > >  }
> > 
> > Hi,
> > Please explain why this is impossible.
> > 
> > If some caller calls order_to_index(5), it will return -1, yes?
> > 
> 
> I was happy enough with the comment as-is given that I suggested it.
> But an alternative comment could be "/* This is impossible.
> We always pass valid values to this function. */

Another option is to just change the BUG_ON() to a WARN_ON().  I feel
like that communicates the same thing but makes checkpatch happy.

regards,
dan carpenter