[PATCH] powerpc/lib: Avoid array bounds warnings in vec ops

Naveen N Rao naveen at kernel.org
Fri Nov 24 21:42:37 AEDT 2023

On Thu, Nov 23, 2023 at 09:17:54AM -0600, Gustavo A. R. Silva wrote:
> > > To be honest I don't know how paranoid we want to get, we could end up
> > > putting WARN's all over the kernel :)
> > > 
> > > In this case I guess if the size is too large we overflow the buffer on
> > > the kernel stack, so we should at least check the size.
> > > 
> > > But does it need a WARN? I'm not sure. If we had a case that was passing
> > > a out-of-bound size hopefully we would notice in testing? :)
> > 
> > You're right, a simpler check should suffice. I will send an updated
> > patch.
> This[1] patch indeed also makes those -Wstringop-overflow warnings go away. :)
> I'm not subscribed to the list but here are my
> Reviewed-by: Gustavo A. R. Silva <gustavoars at kernel.org>
> Build-tested-by: Gustavo A. R. Silva <gustavoars at kernel.org>

Thanks for testing. I intended my patch to go atop Michael's patch since 
do_fp_load()/do_fp_store() also clamp down the size passed to 
do_byte_reverse(). While the use of min() isn't strictly necessary with 
the added check for 'size' at the beginning of the function, it doesn't 
hurt to have it and Michael's patch does have a better description for 
the change :)

- Naveen

More information about the Linuxppc-dev mailing list