Messages in this thread | | | Date | Wed, 19 May 2021 08:56:33 +0200 | From | Peter Zijlstra <> | Subject | Re: [tip: objtool/core] jump_label, x86: Allow short NOPs |
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On Tue, May 18, 2021 at 07:44:11PM -0500, Josh Poimboeuf wrote:
> I'm not exactly thrilled that objtool now has the power to easily brick > a system :-/ Is it really worth it?
The way I look at it is that not running objtool is a bug either way, bricking a system is ofcourse a somewhat more drastic failure mode than missing ORC info for example, but neither are good.
As to worth, about half the jump labels are shorter now, this reduces I$ pressure on hot paths. Any little thing to offset the ever increasing bulk seems like a good thing to me. But yes, it would be nice if the assemblers wouldn't suck so bad and this wouldn't need objtool :/ But I've tried poking the tools guys and they don't really seem interested :-(
Also, only dirty builds are affected here; clean builds (always recommended afaik, because dep trouble isn't unheard of) are fine.
> Anyway, here's one way to fix it. Maybe Masahiro has a better idea.
Thanks! lemme go read up on this magic :-)
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