From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bartlomiej Zolnierkiewicz Subject: Re: linux-next: Tree for May 29 (__rdmsr_on_cpu() OOPS) Date: Sat, 30 May 2009 21:37:57 +0200 Message-ID: <200905302137.57644.bzolnier@gmail.com> References: <20090529145018.ff547ea1.sfr@canb.auug.org.au> Mime-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-15" Content-Transfer-Encoding: 7bit Return-path: Received: from mail-ew0-f176.google.com ([209.85.219.176]:55654 "EHLO mail-ew0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756167AbZE3Tff (ORCPT ); Sat, 30 May 2009 15:35:35 -0400 In-Reply-To: <20090529145018.ff547ea1.sfr@canb.auug.org.au> Content-Disposition: inline Sender: linux-next-owner@vger.kernel.org List-ID: To: Stephen Rothwell Cc: linux-next@vger.kernel.org, LKML , Borislav Petkov next-20090529 oopses in __rdmsr_on_cpu() on my Pentium M laptop. .jpg + .config: http://www.kernel.org/pub/linux/kernel/people/bart/next-20090529-oops.* (gdb) l *0xc023410f 0xc023410f is in __rdmsr_on_cpu (arch/x86/lib/msr.c:25). 20 if (rv->msrs) 21 reg = &rv->msrs[this_cpu - rv->off]; 22 else 23 reg = &rv->reg; 24 25 rdmsr(rv->msr_no, reg->l, reg->h); 26 } 27 28 static void __wrmsr_on_cpu(void *info) 29 { Thus the problem seems to be introduced by: commit 23d19840368b2787d2da97ad0f0f29248503648a Author: Borislav Petkov Date: Fri May 22 13:52:19 2009 +0200 x86: MSR: add methods for writing of an MSR on several CPUs ... and indeed the following patch fixes it: [ Borislav, feel free to fold it into the above change or replace by a more complete one if needed (there may be more rv fields needing initialization). ] From: Bartlomiej Zolnierkiewicz Subject: [PATCH] x86: MSR: fix __rdmsr_on_cpu() OOPS {rd,wr}msr_on_cpu() need to explicitly initalize rv.msrs (since rv is allocated on the stack). Cc: Borislav Petkov Signed-off-by: Bartlomiej Zolnierkiewicz --- arch/x86/lib/msr.c | 2 ++ 1 file changed, 2 insertions(+) Index: b/arch/x86/lib/msr.c =================================================================== --- a/arch/x86/lib/msr.c +++ b/arch/x86/lib/msr.c @@ -44,6 +44,7 @@ int rdmsr_on_cpu(unsigned int cpu, u32 m int err; struct msr_info rv; + rv.msrs = NULL; rv.msr_no = msr_no; err = smp_call_function_single(cpu, __rdmsr_on_cpu, &rv, 1); *l = rv.reg.l; @@ -58,6 +59,7 @@ int wrmsr_on_cpu(unsigned int cpu, u32 m int err; struct msr_info rv; + rv.msrs = NULL; rv.msr_no = msr_no; rv.reg.l = l; rv.reg.h = h;