Re: [PATCH] selftests/ftrace: Let fprobe test consider already enabled functions
From: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Date: 2025-02-26 14:54:50
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On Wed, 26 Feb 2025 15:27:03 +0100 Heiko Carstens [off-list ref] wrote:
The fprobe test fails on Fedora 41 since the fprobe test assumption that the number of enabled_functions is zero before the test starts is not necessarily true. Some user space tools, like systemd, add BPF programs that attach to functions. Those will show up in the enabled_functions table and must be taken into account by the fprobe test.
Hmm, this ftrace selftests has been expected to be run without any BPF programs... Is there any other issue on other test cases? Anyway, this looks good to me. Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Thank you!
quoted hunk ↗ jump to hunk
Therefore count the number of lines of enabled_functions before tests start, and use that as base when comparing expected results. Fixes: e85c5e9792b9 ("selftests/ftrace: Update fprobe test to check enabled_functions file") Signed-off-by: Heiko Carstens <hca@linux.ibm.com> --- .../test.d/dynevent/add_remove_fprobe.tc | 18 +++++++++++------- 1 file changed, 11 insertions(+), 7 deletions(-)diff --git a/tools/testing/selftests/ftrace/test.d/dynevent/add_remove_fprobe.tc b/tools/testing/selftests/ftrace/test.d/dynevent/add_remove_fprobe.tc index 449f9d8be746..73f6c6fcecab 100644 --- a/tools/testing/selftests/ftrace/test.d/dynevent/add_remove_fprobe.tc +++ b/tools/testing/selftests/ftrace/test.d/dynevent/add_remove_fprobe.tc@@ -10,12 +10,16 @@ PLACE=$FUNCTION_FORK PLACE2="kmem_cache_free" PLACE3="schedule_timeout" +# Some functions may have BPF programs attached, therefore +# count already enabled_functions before tests start +ocnt=`cat enabled_functions | wc -l` + echo "f:myevent1 $PLACE" >> dynamic_events # Make sure the event is attached and is the only one grep -q $PLACE enabled_functions cnt=`cat enabled_functions | wc -l` -if [ $cnt -ne 1 ]; then +if [ $cnt -ne $((ocnt + 1)) ]; then exit_fail fi@@ -23,7 +27,7 @@ echo "f:myevent2 $PLACE%return" >> dynamic_events # It should till be the only attached function cnt=`cat enabled_functions | wc -l` -if [ $cnt -ne 1 ]; then +if [ $cnt -ne $((ocnt + 1)) ]; then exit_fail fi@@ -32,7 +36,7 @@ echo "f:myevent3 $PLACE2" >> dynamic_events grep -q $PLACE2 enabled_functions cnt=`cat enabled_functions | wc -l` -if [ $cnt -ne 2 ]; then +if [ $cnt -ne $((ocnt + 2)) ]; then exit_fail fi@@ -49,7 +53,7 @@ grep -q myevent1 dynamic_events # should still have 2 left cnt=`cat enabled_functions | wc -l` -if [ $cnt -ne 2 ]; then +if [ $cnt -ne $((ocnt + 2)) ]; then exit_fail fi@@ -57,7 +61,7 @@ echo > dynamic_events # Should have none left cnt=`cat enabled_functions | wc -l` -if [ $cnt -ne 0 ]; then +if [ $cnt -ne $ocnt ]; then exit_fail fi@@ -65,7 +69,7 @@ echo "f:myevent4 $PLACE" >> dynamic_events # Should only have one enabled cnt=`cat enabled_functions | wc -l` -if [ $cnt -ne 1 ]; then +if [ $cnt -ne $((ocnt + 1)) ]; then exit_fail fi@@ -73,7 +77,7 @@ echo > dynamic_events # Should have none left cnt=`cat enabled_functions | wc -l` -if [ $cnt -ne 0 ]; then +if [ $cnt -ne $ocnt ]; then exit_fail fi-- 2.45.2
-- Masami Hiramatsu (Google) [off-list ref]