[PATCH v2] selftests/ftrace: adjust offset for kprobe syntax error test

[Shuah Khan]

On 12/3/24 18:20, Steven Rostedt wrote:
> On Tue, 3 Dec 2024 18:01:06 -0700
> Shuah Khan <skhan at linuxfoundation.org> wrote:
> 
>> On 12/2/24 12:41, Steven Rostedt wrote:
>>> On Sat, 30 Nov 2024 01:56:21 +0530
>>> Hari Bathini <hbathini at linux.ibm.com> wrote:
>>>    
>>>> 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 at kernel.org>
>>>> Signed-off-by: Hari Bathini <hbathini at linux.ibm.com>
>>>
>>> Acked-by: Steven Rostedt (Google) <rostedt at 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")
> 

I applied this to linux-kselftest fixes - will send it up for rc2 or rc3

thanks,
-- Shuah