From: Thomas Richter <tmricht@xxxxxxxxxxxxxxxxxx> [ Upstream commit 3440fe2790aa3d13530260af6033533b18959aee ] Commit d78ada4a767 ("perf tests attr: Do not store failed events") does not create an event file in the /tmp directory when the perf_open_event() system call failed. This can lead to a situation where not /tmp/event-xx-yy-zz result file exists at all (for example on a s390x virtual machine environment) where no CPUMF hardware is available. The following command then fails with a python call back chain instead of printing failure: [root@s8360046 perf]# /usr/bin/python2 ./tests/attr.py -d ./tests/attr/ \ -p ./perf -v -ttest-stat-basic running './tests/attr//test-stat-basic' Traceback (most recent call last): File "./tests/attr.py", line 379, in <module> main() File "./tests/attr.py", line 370, in main run_tests(options) File "./tests/attr.py", line 311, in run_tests Test(f, options).run() File "./tests/attr.py", line 300, in run self.compare(self.expect, self.result) File "./tests/attr.py", line 248, in compare exp_event.diff(res_event) UnboundLocalError: local variable 'res_event' referenced before assignment [root@s8360046 perf]# This patch catches this pitfall and prints an error message instead: [root@s8360047 perf]# /usr/bin/python2 ./tests/attr.py -d ./tests/attr/ \ -p ./perf -vvv -ttest-stat-basic running './tests/attr//test-stat-basic' loading expected events Event event:base-stat fd = 1 group_fd = -1 flags = 0|8 [....] sample_regs_user = 0 sample_stack_user = 0 'PERF_TEST_ATTR=/tmp/tmpJbMQMP ./perf stat -o /tmp/tmpJbMQMP/perf.data -e cycles kill >/dev/null 2>&1' ret '1', expected '1' loading result events compare matching [event:base-stat] match: [event:base-stat] matches [] res_event is empty FAILED './tests/attr//test-stat-basic' - match failure [root@s8360047 perf]# Signed-off-by: Thomas-Mich Richter <tmricht@xxxxxxxxxxxxxxxxxx> Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx> Cc: Heiko Carstens <heiko.carstens@xxxxxxxxxx> Cc: Hendrik Brueckner <brueckner@xxxxxxxxxxxxxxxxxx> Cc: Martin Schwidefsky <schwidefsky@xxxxxxxxxx> Cc: Thomas-Mich Richter <tmricht@xxxxxxxxxxxxxxxxxx> LPU-Reference: 20170913081209.39570-1-tmricht@xxxxxxxxxxxxxxxxxx Link: http://lkml.kernel.org/n/tip-04d63nn7svfgxdhi60gq2mlm@xxxxxxxxxxxxxx Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx> --- tools/perf/tests/attr.py | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/tools/perf/tests/attr.py b/tools/perf/tests/attr.py index 907b1b2f56ad..ff9b60b99f52 100644 --- a/tools/perf/tests/attr.py +++ b/tools/perf/tests/attr.py @@ -238,6 +238,7 @@ class Test(object): # events in result. Fail if there's not any. for exp_name, exp_event in expect.items(): exp_list = [] + res_event = {} log.debug(" matching [%s]" % exp_name) for res_name, res_event in result.items(): log.debug(" to [%s]" % res_name) @@ -254,7 +255,10 @@ class Test(object): if exp_event.optional(): log.debug(" %s does not match, but is optional" % exp_name) else: - exp_event.diff(res_event) + if not res_event: + log.debug(" res_event is empty"); + else: + exp_event.diff(res_event) raise Fail(self, 'match failure'); match[exp_name] = exp_list -- 2.11.0