Re: [PATCH v2 06/20] x86/alternative: use temporary mm for text poking

From: Nadav Amit
Date: Tue Feb 05 2019 - 12:55:05 EST

> On Feb 5, 2019, at 4:35 AM, Borislav Petkov <bp@xxxxxxxxx> wrote:
> On Tue, Feb 05, 2019 at 12:31:46PM +0100, Peter Zijlstra wrote:
>> ...
>> So while in general I agree with BUG_ON() being undesirable, I think
>> liberal sprinking in text_poke() is fine; you really _REALLY_ want this
>> to work or fail loudly. Text corruption is just painful.
> Ok. It would be good to have the gist of this sentiment in a comment
> above it so that it is absolutely clear why we're doing it.

I added a short comment for v3 above each BUG_ON().

> And since text_poke() can't fail, then it doesn't need a retval too.
> AFAICT, nothing is actually using it.

As Peter said, this is addressed in a separate patch (one patch per logical