Messages in this thread | | | Date | Wed, 30 Oct 2013 22:31:39 +0000 | From | Will Deacon <> | Subject | Re: [BUG] perf: arch_perf_out_copy_user default |
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Hi Peter,
On Wed, Oct 30, 2013 at 08:16:22PM +0000, Peter Zijlstra wrote: > On Wed, Oct 30, 2013 at 08:50:28PM +0100, Frederic Weisbecker wrote: > > > > Would it make sense to rather make copy_from_user_nmi() to use a return value > > pattern that is closer to those of the existing copy_from_user_*() ? > > Yeah we can do that I suppose; copy_form_user_nmi() actually uses > __copy_from_user_inatomic() since about a week. > > Something like so I suppose.. please check, I'm in fail mode. > > It looks like DEFINE_OUTPUT_COPY() functions already returned the bytes > not copied, and all its users appear to indeed expect that. > > --- > arch/x86/kernel/cpu/perf_event.c | 4 ++-- > arch/x86/kernel/cpu/perf_event_intel_ds.c | 2 +- > arch/x86/kernel/cpu/perf_event_intel_lbr.c | 2 +- > arch/x86/lib/usercopy.c | 2 +- > arch/x86/oprofile/backtrace.c | 4 ++-- > kernel/events/internal.h | 35 ++++++++++++++++++++++-------- > 6 files changed, 33 insertions(+), 16 deletions(-)
The core changes look good to me, and I've tested that this still produces callchain information for ARM. It's odd that this worked so well before...
Acked-by: Will Deacon <will.deacon@arm.com>
Will
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