Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762839Ab2KBNxw (ORCPT ); Fri, 2 Nov 2012 09:53:52 -0400 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122]:18163 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756667Ab2KBNxu (ORCPT ); Fri, 2 Nov 2012 09:53:50 -0400 X-Authority-Analysis: v=2.0 cv=KcBQQHkD c=1 sm=0 a=rXTBtCOcEpjy1lPqhTCpEQ==:17 a=mNMOxpOpBa8A:10 a=EaluEUCYuSkA:10 a=5SG0PmZfjMsA:10 a=Q9fys5e9bTEA:10 a=meVymXHHAAAA:8 a=U_9UZLlTPtUA:10 a=e_WWyB8VTG0ISMvLWkIA:9 a=PUjeQqilurYA:10 a=rXTBtCOcEpjy1lPqhTCpEQ==:117 X-Cloudmark-Score: 0 X-Originating-IP: 74.67.115.198 Message-ID: <1351864429.4004.131.camel@gandalf.local.home> Subject: Re: [PATCH] [PATCH] x86: Don't clobber top of pt_regs in nested NMI From: Steven Rostedt To: Jan Beulich Cc: sqazi@google.com, peterz@infradead.org, tglx@linutronix.de, torvalds@linux-foundation.org, hpa@linux.intel.com, linux-kernel@vger.kernel.org Date: Fri, 02 Nov 2012 09:53:49 -0400 In-Reply-To: <1351864310.4004.130.camel@gandalf.local.home> References: <20121002002919.27236.14388.stgit@dungbeetle.mtv.corp.google.com> <1351731872.4004.112.camel@gandalf.local.home> <5092D31C020000780008EB6B@nat28.tlf.novell.com> <1351864310.4004.130.camel@gandalf.local.home> Content-Type: text/plain; charset="ISO-8859-15" X-Mailer: Evolution 3.4.3-1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1193 Lines: 39 On Fri, 2012-11-02 at 09:51 -0400, Steven Rostedt wrote: > On Thu, 2012-11-01 at 19:53 +0000, Jan Beulich wrote: > > > There doesn't appear to be anything special about these adjustments, so I > > don't see what help would be required here - it ought to be the normal use > > of CFI_ADJUST_CFA_OFFSET that needs adding. > > This change look fine to you? > > diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S > index 52edf92..7ba5342 100644 > --- a/arch/x86/kernel/entry_64.S > +++ b/arch/x86/kernel/entry_64.S > @@ -1796,10 +1796,12 @@ repeat_nmi: > > /* Make another copy, this one may be modified by nested NMIs */ > addq $(10*8), %rsp > + CFI_ADJUST_CFA_OFFSET -10*8 > .rept 5 > pushq_cfi -6*8(%rsp) > .endr > subq $(5*8), %rsp > + CFI_ADJUST_CFA_OFFSET 5*8 > > CFI_DEF_CFA_OFFSET SS+8-RIP > end_repeat_nmi: > Is that second one even needed? Or will the CFI_DEF_CFA_OFFSET SS+8-RIP fix it? -- Steve -- 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/