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

Greg KH
2019-02-26T13:08:08Z

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,

greg k-h