Re: [PATCH] selftests/ftrace: Extend multiple_kprobes.tc to add multiple consecutive probes in a function
From: Naveen N. Rao <hidden>
Date: 2023-01-12 13:21:32
Also in:
linux-kselftest, lkml
Akanksha J N wrote:
Commit 97f88a3d723162 ("powerpc/kprobes: Fix null pointer reference in
arch_prepare_kprobe()") fixed a recent kernel oops that was caused as
ftrace-based kprobe does not generate kprobe::ainsn::insn and it gets
set to NULL.
Extend multiple kprobes test to add kprobes on first 256 bytes within a
function, to be able to test potential issues with kprobes on
successive instructions.
The '|| true' is added with the echo statement to ignore errors that are
caused by trying to add kprobes to non probeable lines and continue with
the test.
Signed-off-by: Akanksha J N <redacted>
---
.../selftests/ftrace/test.d/kprobe/multiple_kprobes.tc | 4 ++++
1 file changed, 4 insertions(+)Thanks for adding this test!
quoted hunk
diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/multiple_kprobes.tc b/tools/testing/selftests/ftrace/test.d/kprobe/multiple_kprobes.tc index be754f5bcf79..f005c2542baa 100644 --- a/tools/testing/selftests/ftrace/test.d/kprobe/multiple_kprobes.tc +++ b/tools/testing/selftests/ftrace/test.d/kprobe/multiple_kprobes.tc@@ -25,6 +25,10 @@ if [ $L -ne 256 ]; then exit_fail fi +for i in `seq 0 255`; do + echo p $FUNCTION_FORK+${i} >> kprobe_events || true +done + cat kprobe_events >> $testlog echo 1 > events/kprobes/enable
Thinking about this more, I wonder if we should add an explicit fork after enabling the events, similar to kprobe_args.tc: ( echo "forked" ) That will ensure we hit all the probes we added. With that change: Acked-by: Naveen N. Rao <redacted> - Naveen