Re: [PATCH 1/2] stackleak: Update for arm64

[Laura Abbott]

On 02/22/2018 08:58 AM, Will Deacon wrote:
> Hi Laura,
>
> On Tue, Feb 20, 2018 at 05:13:02PM -0800, Laura Abbott wrote:
> > arm64 has another layer of indirection in the RTL.
> > Account for this in the plugin.
> >
> > Signed-off-by: Laura Abbott <labbott@xxxxxxxxxx>
> > ---
> >   scripts/gcc-plugins/stackleak_plugin.c | 5 +++++
> >   1 file changed, 5 insertions(+)
> >
> > diff --git a/scripts/gcc-plugins/stackleak_plugin.c b/scripts/gcc-plugins/stackleak_plugin.c
> > index 6fc991c98d8b..7dfaa027423f 100644
> > --- a/scripts/gcc-plugins/stackleak_plugin.c
> > +++ b/scripts/gcc-plugins/stackleak_plugin.c
> > @@ -244,6 +244,11 @@ static unsigned int stackleak_final_execute(void)
> >   		 * that insn.
> >   		 */
> >   		body = PATTERN(insn);
> > +		/* arm64 is different */
> > +		if (GET_CODE(body) == PARALLEL) {
> > +			body = XEXP(body, 0);
> > +			body = XEXP(body, 0);
> > +		}
>
> Like most kernel developers, I don't know the first thing about GCC internals
> so I asked our GCC team and Richard (CC'd) reckons this should be:
>
> 	if (GET_CODE(body) == PARALLEL)
> 		body = XVECEXP(body, 0, 0);
>
> instead of the hunk above. Can you give that a go instead, please?
>
> Cheers,
>
> Will

Yep, seems to work fine and makes sense from my understanding of
gcc internals. I'll fix it up for the next version. Thanks for the
review!

Laura