Re: [PATCH 28/32] s390/traps: Unpoison the kernel_stack_overflow()'s pt_regs

From: Alexander Potapenko
Date: Thu Nov 16 2023 - 10:33:25 EST


On Wed, Nov 15, 2023 at 9:35 PM Ilya Leoshkevich <iii@xxxxxxxxxxxxx> wrote:
>
> This is normally done by the generic entry code, but the
> kernel_stack_overflow() flow bypasses it.
>
> Signed-off-by: Ilya Leoshkevich <iii@xxxxxxxxxxxxx>
Reviewed-by: Alexander Potapenko <glider@xxxxxxxxxx>

> ---
> arch/s390/kernel/traps.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/arch/s390/kernel/traps.c b/arch/s390/kernel/traps.c
> index 1d2aa448d103..dd7362806dbb 100644
> --- a/arch/s390/kernel/traps.c
> +++ b/arch/s390/kernel/traps.c
> @@ -27,6 +27,7 @@
> #include <linux/uaccess.h>
> #include <linux/cpu.h>
> #include <linux/entry-common.h>
> +#include <linux/kmsan.h>
> #include <asm/asm-extable.h>
> #include <asm/fpu/api.h>
> #include <asm/vtime.h>
> @@ -260,6 +261,7 @@ static void monitor_event_exception(struct pt_regs *regs)
>
> void kernel_stack_overflow(struct pt_regs *regs)
> {
> + kmsan_unpoison_entry_regs(regs);

I suggest adding a comment here.