Messages in this thread | | | Date | Thu, 1 Aug 2013 15:54:01 +0200 | From | Jiri Olsa <> | Subject | Re: [PATCH 2/8] perf: Sanitize get_callchain_buffer() |
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On Thu, Aug 01, 2013 at 03:49:36PM +0200, Frederic Weisbecker wrote: > On Thu, Aug 01, 2013 at 03:32:17PM +0200, Jiri Olsa wrote: > > On Thu, Aug 01, 2013 at 03:28:34PM +0200, Frederic Weisbecker wrote: > > > > SNIP > > > > > > also for following case: > > > > > > > > count = atomic_inc_return(&nr_callchain_events); > > > > if (WARN_ON_ONCE(count < 1)) { > > > > err = -EINVAL; > > > > goto exit; > > > > } > > > > > > > > seems like it screws the count > > > > > > I'm not sure what you mean here. You mean that it could be negative when the dec is done > > > outside the lock? > > > > yes > > > > I don't understand why.
ah ok, with the count being 0 the nr_callchain_events still increments right? then it's ok..
jirka
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