Messages in this thread | | | From | Andy Lutomirski <> | Date | Mon, 26 Nov 2018 08:33:33 -0800 | Subject | Re: [PATCH v2 4/4] x86/static_call: Add inline static call implementation for x86-64 |
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On Mon, Nov 26, 2018 at 8:11 AM Ard Biesheuvel <ard.biesheuvel@linaro.org> wrote: > > On Mon, 26 Nov 2018 at 17:08, Peter Zijlstra <peterz@infradead.org> wrote: > > > > On Mon, Nov 26, 2018 at 07:55:00AM -0600, Josh Poimboeuf wrote: > > > +#ifdef CONFIG_HAVE_STATIC_CALL_INLINE > > > +void arch_static_call_defuse_tramp(void *site, void *tramp) > > > +{ > > > + unsigned short opcode = INSN_UD2; > > > + > > > + mutex_lock(&text_mutex); > > > + text_poke((void *)tramp, &opcode, 2); > > > + mutex_unlock(&text_mutex); > > > +} > > > +#endif > > > > I would rather think that makes the trampoline _more_ dangerous, rather > > than less so. > > > > My dictionary sayeth: > > > > defuse: verb > > > > - remove the fuse from (an explosive device) in order to prevent it > > from exploding. > > > > - make (a situation) less tense or dangerous > > > > patching in an UD2 seems to do the exact opposite. > > That is my fault. > > The original name was 'poison' iirc, but on arm64, we need to retain > the trampoline for cases where the direct branch is out of range, and > so poisoning is semantically inaccurate. > > But since you opened your dictionary anyway, any better suggestions? :-)
Release? Finish?
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