Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759204AbcCDRtH (ORCPT ); Fri, 4 Mar 2016 12:49:07 -0500 Received: from mail-wm0-f68.google.com ([74.125.82.68]:36552 "EHLO mail-wm0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756801AbcCDRtF (ORCPT ); Fri, 4 Mar 2016 12:49:05 -0500 Date: Fri, 4 Mar 2016 18:49:01 +0100 From: Michal Hocko To: Hidehiro Kawai Cc: Andrew Morton , Thomas Mingarelli , Wim Van Sebroeck , Corey Minyard , Javi Merino , linux-watchdog@vger.kernel.org, "Steven Rostedt (Red Hat)" , Rasmus Villemoes , linux-kernel@vger.kernel.org, Michal Nazarewicz , Vitaly Kuznetsov , HATAYAMA Daisuke , Borislav Petkov , Gobinda Charan Maji , Tejun Heo , Nicolas Iooss , openipmi-developer@lists.sourceforge.net, Borislav Petkov , Thomas Gleixner , Guenter Roeck Subject: Re: [v3 PATCH 1/3] panic: Change nmi_panic from macro to function Message-ID: <20160304174900.GC24204@dhcp22.suse.cz> References: <20160303105741.4587.49047.stgit@softrs> <20160303105744.4587.1001.stgit@softrs> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160303105744.4587.1001.stgit@softrs> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3763 Lines: 113 On Thu 03-03-16 19:57:44, Hidehiro Kawai wrote: > Change nmi_panic() macro to a normal function for the portability. > Also, export it for modules. I guess you wanted to say " Change nmi_panic() from macro to a normal function so that it can be exported to modules. At least ipmi and hpwdt watchdogs can be compiled as a module and need to panic from the NMI context. " > > Changes since v2: > - Make nmi_panic receive a single string instead of printf style args > > Signed-off-by: Hidehiro Kawai > Cc: Andrew Morton > Cc: Borislav Petkov > Cc: Michal Nazarewicz > Cc: Michal Hocko > Cc: Rasmus Villemoes > Cc: Nicolas Iooss > Cc: Javi Merino > Cc: Gobinda Charan Maji > Cc: "Steven Rostedt (Red Hat)" > Cc: Thomas Gleixner > Cc: Vitaly Kuznetsov > Cc: HATAYAMA Daisuke > Cc: Tejun Heo For the change itself Acked-by: Michal Hocko > --- > include/linux/kernel.h | 21 +-------------------- > kernel/panic.c | 20 ++++++++++++++++++++ > 2 files changed, 21 insertions(+), 20 deletions(-) > > diff --git a/include/linux/kernel.h b/include/linux/kernel.h > index f31638c..cbe7d70 100644 > --- a/include/linux/kernel.h > +++ b/include/linux/kernel.h > @@ -255,7 +255,7 @@ extern long (*panic_blink)(int state); > __printf(1, 2) > void panic(const char *fmt, ...) > __noreturn __cold; > -void nmi_panic_self_stop(struct pt_regs *); > +void nmi_panic(struct pt_regs *regs, const char *msg); > extern void oops_enter(void); > extern void oops_exit(void); > void print_oops_end_marker(void); > @@ -455,25 +455,6 @@ extern atomic_t panic_cpu; > #define PANIC_CPU_INVALID -1 > > /* > - * A variant of panic() called from NMI context. We return if we've already > - * panicked on this CPU. If another CPU already panicked, loop in > - * nmi_panic_self_stop() which can provide architecture dependent code such > - * as saving register state for crash dump. > - */ > -#define nmi_panic(regs, fmt, ...) \ > -do { \ > - int old_cpu, cpu; \ > - \ > - cpu = raw_smp_processor_id(); \ > - old_cpu = atomic_cmpxchg(&panic_cpu, PANIC_CPU_INVALID, cpu); \ > - \ > - if (old_cpu == PANIC_CPU_INVALID) \ > - panic(fmt, ##__VA_ARGS__); \ > - else if (old_cpu != cpu) \ > - nmi_panic_self_stop(regs); \ > -} while (0) > - > -/* > * Only to be used by arch init code. If the user over-wrote the default > * CONFIG_PANIC_TIMEOUT, honor it. > */ > diff --git a/kernel/panic.c b/kernel/panic.c > index d96469d..8abfc30 100644 > --- a/kernel/panic.c > +++ b/kernel/panic.c > @@ -72,6 +72,26 @@ void __weak nmi_panic_self_stop(struct pt_regs *regs) > > atomic_t panic_cpu = ATOMIC_INIT(PANIC_CPU_INVALID); > > +/* > + * A variant of panic() called from NMI context. We return if we've already > + * panicked on this CPU. If another CPU already panicked, loop in > + * nmi_panic_self_stop() which can provide architecture dependent code such > + * as saving register state for crash dump. > + */ > +void nmi_panic(struct pt_regs *regs, const char *msg) > +{ > + int old_cpu, cpu; > + > + cpu = raw_smp_processor_id(); > + old_cpu = atomic_cmpxchg(&panic_cpu, PANIC_CPU_INVALID, cpu); > + > + if (old_cpu == PANIC_CPU_INVALID) > + panic("%s", msg); > + else if (old_cpu != cpu) > + nmi_panic_self_stop(regs); > +} > +EXPORT_SYMBOL(nmi_panic); > + > /** > * panic - halt the system > * @fmt: The text string to print > > -- Michal Hocko SUSE Labs