[PATCH v2 01/40] tracing: Exclude 'generic fields' from histograms

From	Tom Zanussi <tom.zanussi@linux.intel.com>
Newsgroups	linux.kernel
Subject	[PATCH v2 01/40] tracing: Exclude 'generic fields' from histograms
Date	2017-09-06 00:10 +0200
Message-ID	<umucG-oz-13@gated-at.bofh.it> (permalink)
References	<umu2Z-5m-5@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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There are a small number of 'generic fields' (comm/COMM/cpu/CPU) that
are found by trace_find_event_field() but are only meant for
filtering.  Specifically, they unlike normal fields, they have a size
of 0 and thus wreak havoc when used as a histogram key.

Exclude these (return -EINVAL) when used as histogram keys.

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
---
 kernel/trace/trace_events_hist.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 1c21d0e..7eb975a 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -450,7 +450,7 @@ static int create_val_field(struct hist_trigger_data *hist_data,
 	}
 
 	field = trace_find_event_field(file->event_call, field_name);
-	if (!field) {
+	if (!field || !field->size) {
 		ret = -EINVAL;
 		goto out;
 	}
@@ -548,7 +548,7 @@ static int create_key_field(struct hist_trigger_data *hist_data,
 		}
 
 		field = trace_find_event_field(file->event_call, field_name);
-		if (!field) {
+		if (!field || !field->size) {
 			ret = -EINVAL;
 			goto out;
 		}
-- 
1.9.3

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[PATCH v2 01/40] tracing: Exclude 'generic fields' from histograms Tom Zanussi <tom.zanussi@linux.intel.com> - 2017-09-06 00:10 +0200

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