Re: feature/asan-gc-poisoning aa9ca2c1493 2/2: src/alloc.c: Fix incorrect pointer arithmetic.

[Vibhav Pant]

Yup, this shouldn't be needed for either branches. I had added the
additional variable to aid readability with __asan_region_is_poisoned.

Thanks,
Vibhav

On Mon, Dec 5, 2022 at 6:36 PM Eli Zaretskii <eliz@gnu.org> wrote:
>
> > From: Po Lu <luangruo@yahoo.com>
> > Cc: Vibhav Pant <vibhavp@gmail.com>
> > Date: Mon, 05 Dec 2022 09:13:59 +0800
> >
> > Vibhav Pant <vibhavp@gmail.com> writes:
> >
> > > branch: feature/asan-gc-poisoning
> > > commit aa9ca2c1493f1cd9d50698747fd054b1be53dc95
> > > Author: Vibhav Pant <vibhavp@gmail.com>
> > > Commit: Vibhav Pant <vibhavp@gmail.com>
> > >
> > >     src/alloc.c: Fix incorrect pointer arithmetic.
> > >
> > >     * src/alloc.c (live_float_holding): Use parenthesis around the
> > >     pointer arithmetic expression to untag 'cp' correctly.
> > > ---
> > >  src/alloc.c | 2 +-
> > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > >
> > > diff --git a/src/alloc.c b/src/alloc.c
> > > index 31108837e5a..6b8a4cdcc02 100644
> > > --- a/src/alloc.c
> > > +++ b/src/alloc.c
> > > @@ -5104,7 +5104,7 @@ live_float_holding (struct mem_node *m, void *p)
> > >       && (b != float_block
> > >           || offset / sizeof b->floats[0] < float_block_index))
> > >     {
> > > -     struct Lisp_Float *f = (struct Lisp_Float *) cp - off;
> > > +     struct Lisp_Float *f = (struct Lisp_Float *) (cp - off);
> > >  #if GC_ASAN_POISON_OBJECTS
> > >       if (__asan_region_is_poisoned (f, sizeof (*f)))
> > >         return NULL;
> >
> > This is a problem on master and emacs-29 too, right?
>
> I don't think so: there are no such code on those two branches, AFAICT.



-- 
Vibhav Pant
vibhavp@gmail.com
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