Messages in this thread | | | Subject | Re: [PATCH] perf/x86: fix broken LBR fixup code | From | Peter Zijlstra <> | Date | Mon, 11 Jun 2012 15:47:44 +0200 |
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On Mon, 2012-06-11 at 15:44 +0200, Stephane Eranian wrote: > I noticed that the LBR fixups were not working anymore > on programs where they used to. I tracked this down to > a recent change to copy_from_user_nmi(). > > commit db0dc75d6403b6663c0eab4c6ccb672eb9b2ed72 > Author: Arun Sharma <asharma@fb.com> > Date: Fri Apr 20 15:41:36 2012 -0700 > > perf/x86: Check user address explicitly in copy_from_user_nmi() > > This commit added a call to __range_not_ok() to the > copy_from_user_nmi() routine. The problem is that the logic > of the test must be reversed. __range_not_ok() returns 0 if the > range is VALID. We want to return early from copy_from_user_nmi() > if the range is NOT valid.
D'0h.. Thanks!
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