Messages in this thread | | | From | Namhyung Kim <> | Subject | Re: [PATCH 3/4] tracing/uprobes: Kill the bogus UPROBE_HANDLER_REMOVE code in uprobe_dispatcher() | Date | Mon, 30 Jun 2014 15:03:29 +0900 |
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On Fri, 27 Jun 2014 19:01:43 +0200, Oleg Nesterov wrote: > I do not know why dd9fa555d7bb "tracing/uprobes: Move argument fetching > to uprobe_dispatcher()" added the UPROBE_HANDLER_REMOVE, but it looks > wrong. > > OK, perhaps it makes sense to avoid store_trace_args() if the tracee is > nacked by uprobe_perf_filter(). But then we should kill the same code > in uprobe_perf_func() and unify the TRACE/PROFILE filtering (we need to > do this anyway to mix perf/ftrace). Until then this code actually adds > the pessimization because uprobe_perf_filter() will be called twice and > return T in likely case.
Right, I wanted to avoid to call the store_trace_args() which might be costly if possible. But it seems not necessary since it doesn't get called once handler returns UPROBE_HANDLER_REMOVE. And we need to fix the filtering first..
So I'm okay with removing this "pessimization". :)
Acked-by: Namhyung Kim <namhyung@kernel.org>
Thanks, Namhyung
> > Signed-off-by: Oleg Nesterov <oleg@redhat.com> > --- > kernel/trace/trace_uprobe.c | 6 ------ > 1 files changed, 0 insertions(+), 6 deletions(-) > > diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c > index 08e7970..c4cf0ab 100644 > --- a/kernel/trace/trace_uprobe.c > +++ b/kernel/trace/trace_uprobe.c > @@ -1208,12 +1208,6 @@ static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs) > > current->utask->vaddr = (unsigned long) &udd; > > -#ifdef CONFIG_PERF_EVENTS > - if ((tu->tp.flags & TP_FLAG_TRACE) == 0 && > - !uprobe_perf_filter(&tu->consumer, 0, current->mm)) > - return UPROBE_HANDLER_REMOVE; > -#endif > - > if (WARN_ON_ONCE(!uprobe_cpu_buffer)) > return 0;
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