Re: [PATCH v2] staging: vchiq_arm: Clear VLA warning

From: Dan Carpenter
Date: Mon Mar 12 2018 - 07:15:02 EST


On Mon, Mar 12, 2018 at 06:58:04AM +0100, Stefan Wahren wrote:
> Hi Tobin,
>
> > "Tobin C. Harding" <me@xxxxxxxx> hat am 12. März 2018 um 06:46 geschrieben:
> >
> >
> > On Mon, Mar 12, 2018 at 12:37:53PM +1100, Tobin C. Harding wrote:
> > > The kernel would like to have all stack VLA usage removed[1]. The array
> > > here is fixed (declared with a const variable) but it appears like a VLA
> > > to the compiler. Also, currently we are putting 768 bytes on the
> > > stack. This function is only called on the error path so performance is
> > > not critical, let's just allocate the memory instead of using the
> > > stack. This saves stack space and removes the VLA build warning.
> > >
> > > kmalloc a buffer for dumping state instead of using the stack.
> > >
> > > [1]: https://lkml.org/lkml/2018/3/7/621
> > >
> > > Signed-off-by: Tobin C. Harding <me@xxxxxxxx>
> > > ---
> >
> > Drop this please, leaks memory.
>
> except from the leak, did you test this patch on a RPi?
>

Hm... Yeah. It looks like we're holding a mutex when we call
vchiq_check_service() from vchiq_queue_message().

regards,
dan carpenter