Re: [PATCH 1/8] kasan,x86: Frob kasan_report() in an exception

From: Linus Torvalds
Date: Wed Mar 06 2019 - 12:36:24 EST

On Wed, Mar 6, 2019 at 9:14 AM Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
> And that (obviously) explodes.. Anybody got any clue why that Xen
> trainwreck wants to paravirt: "PUSHF;POP" and "PUSH;POPF" !?

Trying to regenerate the IF flag? I dunno.

But yeah, I think you could just force all of it into an explicit asm.
Or just use native_save_fl(). Except now that I look at it, for some
reason that is "extern inline" and we have an out-of-line option. I
can't for the life of me imagine why.

[ Looking at history. Oh, it's because of that same Xen issue and Xen
wanting to use it as a function pointer. Ugh. What a crock. ]