Messages in this thread Patch in this message | | | Date | Mon, 15 Jun 2015 17:50:25 -0400 | From | Steven Rostedt <> | Subject | Re: perf,ftrace: fuzzer triggers warning in trace_events_filter code |
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On Fri, 12 Jun 2015 21:15:10 -0400 (EDT) Vince Weaver <vincent.weaver@maine.edu> wrote:
> On Fri, 12 Jun 2015, Steven Rostedt wrote: > > > On Fri, 12 Jun 2015 17:18:22 -0400 (EDT) > > Vince Weaver <vincent.weaver@maine.edu> wrote: > > > > > > > > So I've modified my fuzzer to try to exercise the > > > PERF_EVENT_IOC_SET_FILTER ioctl() and it is starting to turn up some > > > warnings. > > > > Is there any way to know what the filter string you used that generated > > this? > > Various seem to trigger it. One example is > > ext4:ext4_truncate_exit > (((dev<=913)blocks==916)common_type&756) >
Does this patch fix your issue?
-- Steve
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c index 71511ebc70db..dae84db83d97 100644 --- a/kernel/trace/trace_events_filter.c +++ b/kernel/trace/trace_events_filter.c @@ -1369,19 +1369,26 @@ static int check_preds(struct filter_parse_state *ps) { int n_normal_preds = 0, n_logical_preds = 0; struct postfix_elt *elt; + int cnt = 0; list_for_each_entry(elt, &ps->postfix, list) { - if (elt->op == OP_NONE) + if (elt->op == OP_NONE) { + cnt++; continue; + } if (elt->op == OP_AND || elt->op == OP_OR) { n_logical_preds++; + cnt--; continue; } + if (elt->op != OP_NOT) + cnt--; n_normal_preds++; + WARN_ON_ONCE(cnt < 0); } - if (!n_normal_preds || n_logical_preds >= n_normal_preds) { + if (cnt != 1 || !n_normal_preds || n_logical_preds >= n_normal_preds) { parse_error(ps, FILT_ERR_INVALID_FILTER, 0); return -EINVAL; }
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