Hi Aleksa,
On Thu, 1 Nov 2018 19:35:50 +1100 Aleksa Sarai cyphar@cyphar.com wrote: [...]
diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/kretprobe_stacktrace.tc b/tools/testing/selftests/ftrace/test.d/kprobe/kretprobe_stacktrace.tc
Please split the test case as an independent patch.
new file mode 100644 index 000000000000..03146c6a1a3c --- /dev/null +++ b/tools/testing/selftests/ftrace/test.d/kprobe/kretprobe_stacktrace.tc @@ -0,0 +1,25 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0+ +# description: Kretprobe dynamic event with a stacktrace
+[ -f kprobe_events ] || exit_unsupported # this is configurable
+echo 0 > events/enable +echo 1 > options/stacktrace
+echo 'r:teststackprobe sched_fork $retval' > kprobe_events +grep teststackprobe kprobe_events +test -d events/kprobes/teststackprobe
Hmm, what happen if we have 2 or more kretprobes on same stack? It seems you just save stack in pre_handler, but that stack can already includes another kretprobe's trampline address...
Thank you,
+clear_trace +echo 1 > events/kprobes/teststackprobe/enable +( echo "forked") +echo 0 > events/kprobes/teststackprobe/enable
+# Make sure we don't see kretprobe_trampoline and we see _do_fork. +! grep 'kretprobe' trace +grep '_do_fork' trace
+echo '-:teststackprobe' >> kprobe_events +clear_trace
+test -d events/kprobes/teststackprobe && exit_fail || exit_pass
2.19.1