Commit 16e1626e authored Sep 22, 2017 by Tom Zanussi Committed by Greg Kroah-Hartman Dec 25, 2017

tracing: Exclude 'generic fields' from histograms


[ Upstream commit a15f7fc20389a8827d5859907568b201234d4b79 ]

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.

Link: http://lkml.kernel.org/r/956154cbc3e8a4f0633d619b886c97f0f0edf7b4.1506105045.git.tom.zanussi@linux.intel.com



Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 45c911bb

kernel/trace/trace_events_hist.c

+2 −2

Original line number	Original line	Diff line number	Diff line
	@@ -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);		field = trace_find_event_field(file->event_call, field_name);
	if (!field) {		if (!field \|\| !field->size) {
	ret = -EINVAL;		ret = -EINVAL;
	goto out;		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);		field = trace_find_event_field(file->event_call, field_name);
	if (!field) {		if (!field \|\| !field->size) {
	ret = -EINVAL;		ret = -EINVAL;
	goto out;		goto out;
	}		}