Re: [PATCH v1 0/5] Implement livepatch on PPC32

[Christophe Leroy]

Le 14/12/2021 à 07:09, Christophe Leroy a écrit :
> Le 13/12/2021 à 20:46, Steven Rostedt a écrit :
> > On Mon, 13 Dec 2021 19:33:47 +0000
> > Christophe Leroy <christophe.leroy@xxxxxxxxxx> wrote:
> >
> > > STill the same Oops, below
> >
> > Unfortunately, I don't have a PPC machine (32 nor 64 bit) to help debug
> > this.
> >
> >
> > > I will look more closely tomorrow.
> >
> > OK, thanks.
>
> The Oops was due to ftrace_caller() setting the regs argument to NULL.
>
> After fixing that, I'm back into a situation where I get "Testing tracer 
> function_graph: FAILED!"
>
> Will continue investigating.

trace_selftest_startup_function_graph() calls register_ftrace_direct() 
which returns -ENOSUPP because powerpc doesn't select 
CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS.

Should TEST_DIRECT_TRAMP depend on CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS ?

Christophe