Re: [PATCH] x86/kprobes: Fix 1 byte conditional jump target

From: Nadav Amit
Date: Wed Feb 08 2023 - 02:00:46 EST




> On Feb 8, 2023, at 8:56 AM, Dave Hansen <dave.hansen@xxxxxxxxx> wrote:
>
> !! External Email
>
> On 2/7/23 22:34, Nadav Amit wrote:
>> As you said, I guess the change you and Masami proposed can be done on top of
>> this patch, which is (and was) only intended to fix the bug, and should
>> therefore go into 6.2.
>
> Nadav,
>
> To fix this issue, you proposed:
>
> p->ainsn.rel32 = *(s8 *)&insn->immediate.value;
>
> But, this is, um, rather obfuscated and potentially less correct
> compared to:
>
> p->ainsn.rel32 = insn->immediate.value;
>
> I'd appreciate it if you could update your patch to do this simpler
> thing and resend, unless there is a strong reason to do what you
> originally proposed.

I thought it makes sense to make this change for all the other cases
in one pass, but whatever makes you happy.

I will send v2 soon.

Thanks again,
Nadav