Re: [RFC][PATCH] objtool: STAC/CLAC validation

hpa
2019-02-25T08:54:51Z

On February 23, 2019 12:39:42 AM PST, Peter Zijlstra <peterz@infradead.org> wrote:
>On Fri, Feb 22, 2019 at 03:39:48PM -0800, hpa@zytor.com wrote:
>> Objtool could also detect CLAC-STAC or STAC-CLAC sequences without
>> memory operations and remove them; don't know how often that happens,
>> but I know it *does* happen.
>
>Objtool doesn't know about memops; that'd be a lot of work. Also,
>objtool doesn't actually rewrite the text, at best it could warn about
>such occurences.

It doesn't even have to change the text per se, just nullify the altinstr.
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