From: "Steven Rostedt (Google)" rostedt@goodmis.org
The kprobe_eventname.tc test checks if a function with .isra. can have a kprobe attached to it. It loops through the kallsyms file for all the functions that have the .isra. name, and checks if it exists in the available_filter_functions file, and if it does, it uses it to attach a kprobe to it.
The issue is that kprobes can not attach to functions that are listed more than once in available_filter_functions. With the latest kernel, the function that is found is: rapl_event_update.isra.0
# grep rapl_event_update.isra.0 /sys/kernel/tracing/available_filter_functions rapl_event_update.isra.0 rapl_event_update.isra.0
It is listed twice. This causes the attached kprobe to it to fail which in turn fails the test. Instead of just picking the function function that is found in available_filter_functions, pick the first one that is listed only once in available_filter_functions.
Cc: stable@vger.kernel.org Fixes: 604e3548236de ("selftests/ftrace: Select an existing function in kprobe_eventname test") Signed-off-by: Steven Rostedt (Google) rostedt@goodmis.org --- .../testing/selftests/ftrace/test.d/kprobe/kprobe_eventname.tc | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_eventname.tc b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_eventname.tc index 1f6981ef7afa..ba19b81cef39 100644 --- a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_eventname.tc +++ b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_eventname.tc @@ -30,7 +30,8 @@ find_dot_func() { fi
grep " [tT] .*.isra..*" /proc/kallsyms | cut -f 3 -d " " | while read f; do - if grep -s $f available_filter_functions; then + cnt=`grep -s $f available_filter_functions | wc -l`; + if [ $cnt -eq 1 ]; then echo $f break fi