Subject: Re: [External] linux-next: build warning after merge of the ftrace tree

From: Masami Hiramatsu <[email-masked]>
Date: Thu, 6 Aug 2020 02:04:45 +0900

On Wed, 5 Aug 2020 11:11:05 -0400
Steven Rostedt <[email-masked]> wrote:

> On Wed, 5 Aug 2020 12:53:39 +0800
> Muchun Song <[email-masked]> wrote:
> 
> > On Wed, Aug 5, 2020 at 12:21 PM Stephen Rothwell <[email-masked]> wrote:
> > >
> > > Hi all,
> > >
> > > After merging the ftrace tree, today's linux-next build (powerpc
> > > ppc64_defconfig) produced this warning:
> > >
> > > kernel/kprobes.c: In function 'kill_kprobe':
> > > kernel/kprobes.c:1116:33: warning: statement with no effect [-Wunused-value]
> > >  1116 | #define disarm_kprobe_ftrace(p) (-ENODEV)
> > >       |                                 ^
> > > kernel/kprobes.c:2154:3: note: in expansion of macro 'disarm_kprobe_ftrace'
> > >  2154 |   disarm_kprobe_ftrace(p);
> > >       |   ^~~~~~~~~~~~~~~~~~~~
> > >  
> > 
> > Sorry, maybe we should rework the macro of disarm_kprobe_ftrace to an
> > inline function like below.
> > 
> > -#define disarm_kprobe_ftrace(p)        (-ENODEV)
> > +static inline int disarm_kprobe_ftrace(struct kprobe *p)
> > +{
> > +       return -ENODEV
> > +}
> >  #endif
> 
> Looks like that would work. Care to send a formal patch. Could you also
> change arm_kprobe_ftrace() as well?

Looks good to me too as far as updating it to static inline function.

Thank you,

-- 
Masami Hiramatsu <[email-masked]>