Messages in this thread |  | | Subject | Re: [PATCH v2 05/12] x86: rework arch_local_irq_restore() to not use popf | From | Jürgen Groß <> | Date | Sun, 22 Nov 2020 07:55:55 +0100 |
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On 20.11.20 12:59, Peter Zijlstra wrote: > On Fri, Nov 20, 2020 at 12:46:23PM +0100, Juergen Gross wrote: >> +static __always_inline void arch_local_irq_restore(unsigned long flags) >> +{ >> + if (!arch_irqs_disabled_flags(flags)) >> + arch_local_irq_enable(); >> +} > > If someone were to write horrible code like: > > local_irq_disable(); > local_irq_save(flags); > local_irq_enable(); > local_irq_restore(flags); > > we'd be up some creek without a paddle... now I don't _think_ we have > genius code like that, but I'd feel saver if we can haz an assertion in > there somewhere... > > Maybe something like: > > #ifdef CONFIG_DEBUG_ENTRY // for lack of something saner > WARN_ON_ONCE((arch_local_save_flags() ^ flags) & X86_EFLAGS_IF); > #endif > > At the end?
I'd like to, but using WARN_ON_ONCE() in include/asm/irqflags.h sounds like a perfect receipt for include dependency hell.
We could use a plain asm("ud2") instead.
Juergen [unhandled content-type:application/pgp-keys][unhandled content-type:application/pgp-signature] |  |