Messages in this thread | | | Subject | Re: [RFC PATCH 1/9] uaccess: Make copy_from_user_nmi() globally available | From | Peter Zijlstra <> | Date | Wed, 13 Oct 2010 09:15:56 +0200 |
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On Wed, 2010-10-13 at 07:06 +0200, Frederic Weisbecker wrote: > In order to support user stack dump safely in perf samples from > generic code, export copy_from_user_nmi() from x86 and make it > generally available. For most archs it will map to > copy_from_user_inatomic, but for x86 we need to take care of > not faulting from NMIs. > > Since perf is the first user for now, let the overriden x86 > implementation in the perf source file.
It might make sense to call it copy_from_user_gup() because that's bascially what it does, it doesn't rely on NMI context anymore, its just NMI-safe.
Its a best effort software page table walk, and with the stacked kmap_atomic bits Andrew took it should work from any context.
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