From dc4b165855f230247fe02392fc1e29227067c253 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Thu, 20 Feb 2025 14:01:02 +0100 Subject: [PATCH] selftests/ftrace: Use readelf to find entry point in uprobe test 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. Link: https://lore.kernel.org/r/20250220130102.2079179-1-hca@linux.ibm.com Signed-off-by: Heiko Carstens Acked-by: Steven Rostedt (Google) Signed-off-by: Shuah Khan --- .../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 86c76679c56e9..f2048c2445261 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 -- 2.47.2