Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933332Ab2EWKBq (ORCPT ); Wed, 23 May 2012 06:01:46 -0400 Received: from mail.skyhub.de ([78.46.96.112]:57173 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750747Ab2EWKBo (ORCPT ); Wed, 23 May 2012 06:01:44 -0400 Date: Wed, 23 May 2012 12:01:39 +0200 From: Borislav Petkov To: ShuoX Liu Cc: "linux-kernel@vger.kernel.org" , andi@firstfloor.org, Andrew Morton , Yanmin Zhang , Tony Luck Subject: Re: [PATCH] printk: ignore recursion_bug flag when MCE in progress Message-ID: <20120523100138.GA13506@x1.osrc.amd.com> Mail-Followup-To: Borislav Petkov , ShuoX Liu , "linux-kernel@vger.kernel.org" , andi@firstfloor.org, Andrew Morton , Yanmin Zhang , Tony Luck References: <4FBC444A.6060500@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <4FBC444A.6060500@intel.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3321 Lines: 92 + Tony On Wed, May 23, 2012 at 09:58:34AM +0800, ShuoX Liu wrote: > From: ShuoX Liu > > When MCE happens in printk, we ignore recursion_bug to make sure > some MCE logs printed out. Re-use mce_entry variable. > > Signed-off-by: Yanmin Zhang > Signed-off-by: ShuoX Liu > --- > I found mce_entry was introduced by commit 553f265f, but it's not > used now. Why not removed? > --- > arch/x86/include/asm/mce.h | 2 -- > arch/x86/kernel/cpu/mcheck/mce.c | 2 -- > include/linux/kernel.h | 1 + > kernel/printk.c | 4 +++- > 4 files changed, 4 insertions(+), 5 deletions(-) > > diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h > index 441520e..aeda4cc 100644 > --- a/arch/x86/include/asm/mce.h > +++ b/arch/x86/include/asm/mce.h > @@ -187,8 +187,6 @@ int mce_available(struct cpuinfo_x86 *c); > DECLARE_PER_CPU(unsigned, mce_exception_count); > DECLARE_PER_CPU(unsigned, mce_poll_count); > > -extern atomic_t mce_entry; > - > typedef DECLARE_BITMAP(mce_banks_t, MAX_NR_BANKS); > DECLARE_PER_CPU(mce_banks_t, mce_poll_banks); > > diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c > index 11c9166..6073354 100644 > --- a/arch/x86/kernel/cpu/mcheck/mce.c > +++ b/arch/x86/kernel/cpu/mcheck/mce.c > @@ -61,8 +61,6 @@ int mce_disabled __read_mostly; > > #define SPINUNIT 100 /* 100ns */ > > -atomic_t mce_entry; > - > DEFINE_PER_CPU(unsigned, mce_exception_count); > > /* > diff --git a/include/linux/kernel.h b/include/linux/kernel.h > index 645231c..24af685 100644 > --- a/include/linux/kernel.h > +++ b/include/linux/kernel.h > @@ -354,6 +354,7 @@ unsigned long int_sqrt(unsigned long); > extern void bust_spinlocks(int yes); > extern void wake_up_klogd(void); > extern int oops_in_progress; /* If set, an oops, panic(), BUG() or die() is in progress */ > +extern atomic_t mce_entry; > extern int panic_timeout; > extern int panic_on_oops; > extern int panic_on_unrecovered_nmi; > diff --git a/kernel/printk.c b/kernel/printk.c > index 473afdb..2bae087 100644 > --- a/kernel/printk.c > +++ b/kernel/printk.c > @@ -79,6 +79,7 @@ int console_printk[4] = { > int oops_in_progress; > EXPORT_SYMBOL(oops_in_progress); > > +atomic_t mce_entry; > /* > * console_sem protects the console_drivers list, and also > * provides serialisation for access to the entire console > @@ -864,7 +865,8 @@ asmlinkage int vprintk(const char *fmt, va_list args) > * recursion and return - but flag the recursion so that > * it can be printed at the next appropriate moment: > */ > - if (!oops_in_progress && !lockdep_recursing(current)) { > + if (!oops_in_progress && !atomic_read(&mce_entry) This is leaking x86-specific (MCE) stuff in generic kernel code. I think it would be more appropriate to add a in_hw_error() helper or similar and define it on each arch. I can very well imagine other architectures would like to print hw error info too... Hmmm. -- Regards/Gruss, Boris. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/