Re: [PATCH 03/32] s390: Clear pt_regs flags field

[Ilya Leoshkevich]

On 10/1/26 12:32, Heiko Carstens wrote:
> Clear the pt_regs flags field in the early program check handler as well
> as in the stack_invalid handler. Without this the pt_regs flags field will
> have random values, depending on previous stack contents.
>
> This matters currently for bug reporting and disassembly, where flags like
> PIF_PSW_ADDR_ADJUSTED may then be incorrectly set, which could lead to a
> partially incorrect disassembly or wrong code markers.
>
> Signed-off-by: Heiko Carstens <hca@xxxxxxxxxxxxx>
> ---
>   arch/s390/kernel/early.c | 1 +
>   arch/s390/kernel/entry.S | 1 +
>   2 files changed, 2 insertions(+)
>
> diff --git a/arch/s390/kernel/early.c b/arch/s390/kernel/early.c
> index 1fc153d8385b..b8e3c065fbec 100644
> --- a/arch/s390/kernel/early.c
> +++ b/arch/s390/kernel/early.c
> @@ -154,6 +154,7 @@ void __init __do_early_pgm_check(struct pt_regs *regs)
>   {
>   	struct lowcore *lc = get_lowcore();
>   
> +	regs->flags = 0;
>   	regs->int_code = lc->pgm_int_code;
>   	regs->int_parm_long = lc->trans_exc_code;
>   	regs->last_break = lc->pgm_last_break;

Just for my understanding, why can't we do it in C for all handlers?


Reviewed-by: Ilya Leoshkevich <iii@xxxxxxxxxxxxx>