Messages in this thread | | | From | Linus Torvalds <> | Date | Thu, 4 Jan 2018 10:25:35 -0800 | Subject | Re: [PATCH v3 01/13] x86/retpoline: Add initial retpoline support |
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On Thu, Jan 4, 2018 at 10:17 AM, Alexei Starovoitov <alexei.starovoitov@gmail.com> wrote: > > Clearly Paul's approach to retpoline without lfence is faster. > I'm guessing it wasn't shared with amazon/intel until now and > this set of patches going to adopt it, right? > > Paul, could you share a link to a set of alternative gcc patches > that do retpoline similar to llvm diff ?
What is the alternative approach? Is it literally just doing a
call 1f 1: mov real_target,(%rsp) ret
on the assumption that the "ret" will always just predict to that "1" due to the call stack?
Linus
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