Messages in this thread | | | Date | Tue, 6 Mar 2012 10:00:00 -0500 | From | Don Zickus <> | Subject | Re: [PATCH v3 x86 1/2] fix page faults by nmiaction in nmi if kmemcheck is enabled |
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On Tue, Mar 06, 2012 at 06:09:43PM +0800, Li Zhong wrote: > This patch tries to fix the problem of page fault exception caused by > accessing nmiaction structure in nmi if kmemcheck is enabled. > > If kmemcheck is enabled, the memory allocated through slab are in pages > that are marked non-present, so that some checks could be done in the > page fault handling code ( e.g. whether the memory is read before > written to ). > As nmiaction is allocated in this way, so it resides in a non-present > page. Then there is a page fault while the nmi code accessing the > nmiaction structure, which would then cause a warning by > WARN_ON_ONCE(in_nmi()) in kmemcheck_fault(), called by do_page_fault(). > > v2: as Peter suggested, changed the nmiaction to use static storage. > > v3: as Peter suggested, use macro to shorten the codes. Also keep the > original usage of register_nmi_handler, so users of this call doesn't > need change.
Thanks Li! Looks fine to me. I'll run some tests to make sure things still work correctly.
Cheers, Don
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