Messages in this thread | | | From | Linus Torvalds <> | Date | Tue, 19 Jul 2022 10:27:00 -0700 | Subject | Re: [patch 00/38] x86/retbleed: Call depth tracking mitigation |
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On Tue, Jul 19, 2022 at 10:23 AM Sami Tolvanen <samitolvanen@google.com> wrote: > > The preamble hash is encoded into an instruction just to avoid special > casing objtool, which would otherwise get confused about the random > bytes. On arm64, we just emit a bare constant before the function.
Ahh.
I think objtool would want to understand about kCFI anyway, so I think in the long run that hack isn't a goog idea.
But I get why you'd do it as a "do this as just a compiler thing and hide it from objtool" as a development strategy.
Linus
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