Re: [PATCH 1/3] panic: Export panic_cpu and nmi_panic_self_stop

[Michal Hocko <mhocko@kernel.org>]

On Tue 01-03-16 07:48:10, 河合英宏 / KAWAI，HIDEHIRO wrote:
> Hi Borislav,
> 
> > From: Borislav Petkov [mailto:bp@alien8.de]
> > On Tue, Mar 01, 2016 at 10:50:37AM +0900, Hidehiro Kawai wrote:
> > > Export panic_cpu and nmi_panic_self_stop symbols for modules which
> > > use nmi_panic() macro.
> > >
> > > Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
> > > Cc: Andrew Morton <akpm@linux-foundation.org>
> > > Cc: Borislav Petkov <bp@suse.de>
> > > Cc: Thomas Gleixner <tglx@linutronix.de>
> > > Cc: Michal Hocko <mhocko@suse.com>
> > > Cc: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
> > > Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
> > > Cc: Tejun Heo <tj@kernel.org>
> > > ---
> > >  kernel/panic.c |    2 ++
> > >  1 file changed, 2 insertions(+)
> > >
> > > diff --git a/kernel/panic.c b/kernel/panic.c
> > > index d96469d..f4e8035 100644
> > > --- a/kernel/panic.c
> > > +++ b/kernel/panic.c
> > > @@ -69,8 +69,10 @@ void __weak nmi_panic_self_stop(struct pt_regs *regs)
> > >  {
> > >  	panic_smp_self_stop();
> > >  }
> > > +EXPORT_SYMBOL(nmi_panic_self_stop);
> > >
> > >  atomic_t panic_cpu = ATOMIC_INIT(PANIC_CPU_INVALID);
> > > +EXPORT_SYMBOL(panic_cpu);
> > 
> > Can we make nmi_panic() at least a proper function and export that
> > instead of exporting all those implementation details...?
> 
> The reason I implemented nmi_panic() as a macro is to pass
> variable arguments directly to panic().  Fortunately, since all
> invocations of nmi_panic() just pass a fixed string, I can change it
> to a normal function like:
> 
> int nmi_panic(struct pt_regs *regs, const char *msg)
> {
> ...
> 	panic("%s", msg);
> 
> If people don't mind if that, I'll change it.

Yeah, I think this is better. If we ever need a variable strings we can
reconsider.
-- 
Michal Hocko
SUSE Labs