Messages in this thread | | | Date | Wed, 11 Nov 2020 21:42:28 +0100 | From | Peter Zijlstra <> | Subject | Re: WARNING: can't access registers at asm_common_interrupt |
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On Wed, Nov 11, 2020 at 12:13:28PM -0600, Josh Poimboeuf wrote: > On Wed, Nov 11, 2020 at 06:47:36PM +0100, Peter Zijlstra wrote:
> > Yeah, so it's all a giant can of worms that; also see: > > > > https://lkml.kernel.org/r/20200821084738.508092956@infradead.org > > > > The basic idea is to only trace edges, ie. when the hardware state > > actually changes. Sadly this means doing a pushf/pop before the cli. > > Ideally CLI would store the old IF in CF or something like that, but > > alas. > > Right, that makes sense for save/restore, but is the disabled check > really needed for local_irq_disable()? Wouldn't that always be an edge?
IIRC there is code that does local_irq_disable() even though IRQs are already disabled. This is 'harmless'.
> And anyway I don't see a similar check for local_irq_enable().
I know there is code that does local_irq_enable() with IRQs already enabled, I'm not exactly sure why this is different. I'll have to put it on the todo list :/
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