On Thu, 20 Feb 2025 14:01:02 +0100
Heiko Carstens <hca@xxxxxxxxxxxxx> 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@xxxxxxxxxxxxx>
Acked-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
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
