On Thu, 20 Feb 2025 14:01:02 +0100 Heiko Carstens hca@linux.ibm.com wrote:

The uprobe events test fails on s390, but also on x86 (Fedora 41). The problem appears to be that there is an assumption that adding a uprobe to the beginning of the executable mapping of /bin/sh is sufficient to trigger a uprobe event when /bin/sh is executed.

This assumption is not necessarily true. Therefore use "readelf -h" to find the entry point address of /bin/sh and use this address when adding the uprobe event.

This adds a dependency to readelf which is not always installed. Therefore add a check and exit with exit_unresolved if it is not installed.

Signed-off-by: Heiko Carstens hca@linux.ibm.com

Acked-by: Steven Rostedt (Google) rostedt@goodmis.org

Shuah,

Can you take this in your tree?

-- Steve

---

.../ftrace/test.d/dynevent/add_remove_uprobe.tc | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/ftrace/test.d/dynevent/add_remove_uprobe.tc b/tools/testing/selftests/ftrace/test.d/dynevent/add_remove_uprobe.tc index 86c76679c56e..f2048c244526 100644 --- a/tools/testing/selftests/ftrace/test.d/dynevent/add_remove_uprobe.tc +++ b/tools/testing/selftests/ftrace/test.d/dynevent/add_remove_uprobe.tc @@ -3,14 +3,18 @@ # description: Generic dynamic event - add/remove/test uprobe events # requires: uprobe_events +if ! which readelf > /dev/null 2>&1 ; then

• echo "No readelf found. skipped."
• exit_unresolved

+fi

echo 0 > events/enable echo > dynamic_events REALBIN=`readlink -f /bin/sh` +ENTRYPOINT=`readelf -h ${REALBIN} | grep Entry | sed -e 's/[^0]*//'` -echo 'cat /proc/$$/maps' | /bin/sh | \

• grep "r-xp .*${REALBIN}$" | \
• awk '{printf "p:myevent %s:0x%s\n", $6,$3 }' >> uprobe_events

+echo "p:myevent ${REALBIN}:${ENTRYPOINT}" >> uprobe_events grep -q myevent uprobe_events test -d events/uprobes/myevent