Re: [PATCH 30/32] s390/unwind: Disable KMSAN checks

Alexander Potapenko
2023-11-16T09:05:55Z

On Thu, Nov 16, 2023 at 10:04 AM Alexander Potapenko <glider@google.com> wrote:
>
> On Wed, Nov 15, 2023 at 9:35 PM Ilya Leoshkevich <iii@linux.ibm.com> wrote:
> >
> > The unwind code can read uninitialized frames. Furthermore, even in
> > the good case, KMSAN does not emit shadow for backchains. Therefore
> > disable it for the unwinding functions.
> >
> > Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
> > ---
> > arch/s390/kernel/unwind_bc.c | 2 ++
> > 1 file changed, 2 insertions(+)
> >
> > diff --git a/arch/s390/kernel/unwind_bc.c b/arch/s390/kernel/unwind_bc.c
> > index 0ece156fdd7c..7ecaab24783f 100644
> > --- a/arch/s390/kernel/unwind_bc.c
> > +++ b/arch/s390/kernel/unwind_bc.c
> > @@ -49,6 +49,7 @@ static inline bool is_final_pt_regs(struct unwind_state *state,
> > READ_ONCE_NOCHECK(regs->psw.mask) & PSW_MASK_PSTATE;
> > }
> >
> > +__no_kmsan_checks
>
> Please add some comments to the source file to back this annotation,
> so that the intent is not lost in git history.

Apart from that,

Reviewed-by: Alexander Potapenko <glider@google.com>

--
Alexander Potapenko
Software Engineer

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