Messages in this thread | | | Date | Fri, 8 Mar 2019 15:56:02 -0600 | From | Josh Poimboeuf <> | Subject | Re: [PATCH 20/20] objtool: Add Direction Flag validation |
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On Fri, Mar 08, 2019 at 10:33:43PM +0100, Peter Zijlstra wrote: > On Fri, Mar 08, 2019 at 03:16:03PM -0600, Josh Poimboeuf wrote: > > On Thu, Mar 07, 2019 at 12:45:31PM +0100, Peter Zijlstra wrote: > > > Having DF escape is BAD(tm). > > > > > > Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> > > > Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> > > > > Can you elaborate on why (in the patch description)? Did this actually > > find any occurrences? > > Nope, didn't find anything. Also, all DF users are in asm so I didn't > really expect any. Having it escape would probably result in fairly > instant wreckage though. > > DF=1 results in things like rep mov going _backwards_.
Ok, I wonder if we really need to add this then.
-- Josh
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