Re: [bug report][stable] perf probe: failed to add events

Joseph Qi
2019-02-27T01:53:48Z

On 19/2/26 21:08, Greg KH wrote:
> On Tue, Feb 26, 2019 at 08:32:34PM +0800, Joseph Qi wrote:
>>
>>
>> On 19/2/26 17:05, Greg KH wrote:
>>> On Tue, Feb 26, 2019 at 03:31:14PM +0800, Joseph Qi wrote:
>>>> Hi,
>>>>
>>>> I'm using kernel v4.19.24 and have found that there is an issue when
>>>> using perf probe to define a new dynamic tracepoint.
>>>>
>>>> $ perf probe -a handle_mm_fault
>>>> Failed to write event: Numerical result out of range
>>>> Error: Failed to add events.
>>>>
>>>> I've also tried kernel v4.20, and it can pass.
>>>
>>> Ick, has this ever worked on the 4.19 stable tree? If so, any chance
>>> you can run 'git bisect' to find the offending commit?
>>>
>> >From my test, v4.19.0 also has this issue.
>> Bisect locates that it is introduced by commit bf904d2762ee
>> "x86/pti/64: Remove the SYSCALL64 entry trampoline".
>
> But that commit was in 4.20, not 4.19. So if this never worked, it's
> not a regression?
>
> confused,
Oops, my fault.
The first bad commit is:
d83212d5dd67 kallsyms, x86: Export addresses of PTI entry trampolines

It is between v4.18 and v4.19.

>
> greg k-h
>