On Fri, Aug 10, 2018 at 10:16 PM, Hari Vyas <hari.vyas@xxxxxxxxxxxx> wrote: > On Wed, Aug 8, 2018 at 11:53 PM, Florian Fainelli <f.fainelli@xxxxxxxxx> wrote: >> On 08/08/2018 11:18 AM, Hari Vyas wrote: >>> On Tue, Aug 7, 2018 at 5:57 PM, Greg KH <greg@xxxxxxxxx> wrote: >>>> On Tue, Aug 07, 2018 at 04:33:48PM +0530, Hari Vyas wrote: >>>>> bad_mode() handler is called for invalid or undefined >>>>> instruction in el1 level or when irq,fiq,sync or error >>>>> situation happen in el1 or el0 level. >>>>> >>>>> As per latest code, above abnormal situation may not result in >>>>> panic always due to die() call if user mode is determined at >>>>> that moment. That will just result in kill of current process >>>>> and panic will be avoided which it must not. >>>>> >>>>> Link: https://bugzilla.kernel.org/show_bug.cgi?id=200637 >>>>> Signed-off-by: Hari Vyas <hari.vyas@xxxxxxxxxxxx> >>>>> --- >>>>> arch/arm64/kernel/traps.c | 1 - >>>>> 1 file changed, 1 deletion(-) >>>>> >>>>> diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c >>>>> index d399d45..716ee73 100644 >>>>> --- a/arch/arm64/kernel/traps.c >>>>> +++ b/arch/arm64/kernel/traps.c >>>>> @@ -621,7 +621,6 @@ asmlinkage void bad_mode(struct pt_regs *regs, int reason, unsigned int esr) >>>>> handler[reason], smp_processor_id(), esr, >>>>> esr_get_class_string(esr)); >>>>> >>>>> - die("Oops - bad mode", regs, 0); >>>>> local_daif_mask(); >>>>> panic("bad mode"); >>>>> } >>>>> -- >>>>> 1.9.1 >>>> >>>> <formletter> >>>> >>>> This is not the correct way to submit patches for inclusion in the >>>> stable kernel tree. Please read: >>>> https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html >>>> for how to do this properly. >>>> >>>> </formletter> >>> >>> Thanks. Probably my mistake to include stable kernel list for regular >>> minor patch. >>> In any case, will take care about it along with arm maintainers and >>> developers review comments which I am awaiting. >> >> Also, if this is a real fix, then providing an appropriate Fixes: tag >> would help understand when this broke, and how far back this needs to be >> backported to. This of course, assumes that your patch is the right >> course of action. >> -- > As far as I know, bad mode was earlier(linux 3.14 onwards) also not > resulting in panic always. > Trap-exception framework is recently changed some time back but this > concern remains same. > I am also awaiting a response from ARM maintainers before proceeding. > Just to be more clear, this > concern was pointed out in one of my previous-and-some-what-relative > patch about console-verbose > level restoration issue. >> Florian Gentle reminder for Arm maintainers. If concern can be taken care from your side in different ways then bug can be resolved. Regards, hari
