On Thu, 1 Oct 2020 16:40:33 +0100 Colin Ian King colin.king@canonical.com wrote:
On 01/10/2020 15:44, Steven Rostedt wrote:
On Thu, 1 Oct 2020 09:56:41 +0100 Colin King colin.king@canonical.com wrote:
From: Colin Ian King colin.king@canonical.com
More recent libc implementations are now using openat/openat2 system calls so also add do_sys_openat2 to the tracing so that the test passes on these systems because do_sys_open may not be called.
Signed-off-by: Colin Ian King colin.king@canonical.com
.../testing/selftests/ftrace/test.d/kprobe/kprobe_args_user.tc | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_user.tc b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_user.tc index a30a9c07290d..cf1b4c3e9e6b 100644 --- a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_user.tc +++ b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_user.tc @@ -9,6 +9,8 @@ grep -A10 "fetcharg:" README | grep -q '[u]<offset>' || exit_unsupported :;: "user-memory access syntax and ustring working on user memory";: echo 'p:myevent do_sys_open path=+0($arg2):ustring path2=+u0($arg2):string' \
kprobe_events
+echo 'p:myevent2 do_sys_openat2 path=+0($arg2):ustring path2=+u0($arg2):string' \
This still wont work, because the rest of the code only enables the myevent event, and not the one you just added.
Yep, I botched this and tested the wrong fix.
Did you see this broken before, and this patch fixes it?
So this test breaks with a recent libc and support tools built against libc. I believe the do_sys_open is not being detected because do_sys_openat2 is being called instead.
Not sure now of the correct way to fix this.
Hmm, this actually just try to catch the user-string. So the another function which accepts any user-string, is OK. Let me try to use another one.
Thank you for reporting!
-- Steve
grep myevent kprobe_events | \ grep -q 'path=+0($arg2):ustring path2=+u0($arg2):string'