Re: [GIT PULL] x86/urgent for v5.11-rc7

From: Steven Rostedt
Date: Mon Feb 08 2021 - 13:34:22 EST


On Mon, 8 Feb 2021 16:47:05 +0100
Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:

> > /*
> > * Convert a function address into the appropriate ftrace location.
> > *
> > * Usually this is just the address of the function, but on some architectures
> > * it's more complicated so allow them to provide a custom behaviour.
> > */
> > #ifndef klp_get_ftrace_location
> > static unsigned long klp_get_ftrace_location(unsigned long faddr)
> > {
> > return faddr;
> > }
> > #endif
>
> I suppose the trivial fix is to see if it points to endbr64 and if so,
> increment the addr by the length of that.

I thought of that too. But one thing that may be possible, is to use
kallsym. I believe you can get the range of a function (start and end of
the function) from kallsyms. Then ask ftrace for the addr in that range
(there should only be one).

-- Steve