Re: [PATCH v2] selftests/ftrace: adjust offset for kprobe syntax error test
From: Steven Rostedt <rostedt@goodmis.org>
Date: 2024-12-04 01:20:08
Also in:
linux-kselftest, linux-trace-kernel, lkml
From: Steven Rostedt <rostedt@goodmis.org>
Date: 2024-12-04 01:20:08
Also in:
linux-kselftest, linux-trace-kernel, lkml
On Tue, 3 Dec 2024 18:01:06 -0700 Shuah Khan [off-list ref] wrote:
On 12/2/24 12:41, Steven Rostedt wrote:quoted
On Sat, 30 Nov 2024 01:56:21 +0530 Hari Bathini [off-list ref] wrote:quoted
In 'NOFENTRY_ARGS' test case for syntax check, any offset X of `vfs_read+X` except function entry offset (0) fits the criterion, even if that offset is not at instruction boundary, as the parser comes before probing. But with "ENDBR64" instruction on x86, offset 4 is treated as function entry. So, X can't be 4 as well. Thus, 8 was used as offset for the test case. On 64-bit powerpc though, any offset <= 16 can be considered function entry depending on build configuration (see arch_kprobe_on_func_entry() for implementation details). So, use `vfs_read+20` to accommodate that scenario too. Suggested-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org> Shuah, Can you take this through your tree?Yes I can take it. I do have question about whether this is a fix - sounds like it is from the change log. Clearly stating that it is a fix will help so it can be picked up for stables.
I would say it's a fix, as the test currently fails in certain scenarios
for powerpc.
You can add:
Fixes: 4231f30fcc34a ("selftests/ftrace: Add BTF arguments test cases")
-- Steve