selftests/ftrace: Add tracing/error_log testcase

Add a testcase verifying basic tracing/error_log functionality.

Link: http://lkml.kernel.org/r/bf1c0d47a24672df945331462682d96296d1ab28.1554072478.git.tom.zanussi@linux.intel.comAcked-by: NMasami Hiramatsu <mhiramat@kernel.org>
Acked-by: NNamhyung Kim <namhyung@kernel.org>
Signed-off-by: NTom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>

tools/testing/selftests/ftrace/test.d/ftrace/tracing-error-log.tc

+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+# description: ftrace - test tracing error log support
+
+fail() { #msg
+    echo $1
+    exit_fail
+}
+
+# event tracing is currently the only ftrace tracer that uses the
+# tracing error_log, hence this check
+if [ ! -f set_event ]; then
+    echo "event tracing is not supported"
+    exit_unsupported
+fi
+
+ftrace_errlog_check 'event filter parse error' '((sig >= 10 && sig < 15) || dsig ^== 17) && comm != bash' 'events/signal/signal_generate/filter'
+
+exit 0