From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BD0E0C10F11 for ; Wed, 24 Apr 2019 07:26:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8D9CE218B0 for ; Wed, 24 Apr 2019 07:26:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="S9ZpJG/+" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729925AbfDXH0U (ORCPT ); Wed, 24 Apr 2019 03:26:20 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:48080 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727137AbfDXH0T (ORCPT ); Wed, 24 Apr 2019 03:26:19 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=PtDwWHsjJ3ge8kJU+gtqE0dCaufHmcByGNhRyTv1JPk=; b=S9ZpJG/+IgDjcybA2XKz87J3F bFGNihDxmRCDoFiuIJJxMSbeQAKve29TfJWFlCXTWyiA9jzjPzImWa3cON/y7PSGuWusxr0Xr6ZfN zoof4fgKh1/Jcn0nxKo507JwKk+1f8jc1VBBcn2i61B0cY4O6P0xg094dRndzAI6LPIRdUJ6qKs6J u2mOaH8YVFnz2bpq0S0lZ+KKtJBjxHV8bHEMNqAZ5sTb2sYDSVC+Z3ZdHVaseej9YSPGyqlSPqJE4 lSHFtmHwKpoJVSjZuMgTlKbS0bNFrQPvPPI0DpjPUnyLo6jR1ZOiN90YZ3JShs04kQGrZ2MYR9+wX mpW+wG+XA==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by bombadil.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1hJCIG-0002Ol-3F; Wed, 24 Apr 2019 07:26:12 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 86A1029B5ADF1; Wed, 24 Apr 2019 09:26:10 +0200 (CEST) Date: Wed, 24 Apr 2019 09:26:10 +0200 From: Peter Zijlstra To: Jiri Kosina Cc: Dave Hansen , Andy Lutomirski , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , Joerg Roedel , Frederic Weisbecker , Nicolai Stange , x86@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] x86/mm: Remove in_nmi() warning from 64bit implementation of vmalloc_fault() Message-ID: <20190424072610.GF4038@hirez.programming.kicks-ass.net> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Apr 24, 2019 at 09:04:57AM +0200, Jiri Kosina wrote: > From: Jiri Kosina > > In-NMI warnings have been added to vmalloc_fault() via ebc8827f75 ("x86: > Barf when vmalloc and kmemcheck faults happen in NMI") back in the time > when our NMI entry code could not cope with nested NMIs. > > These days, it's perfectly fine to take a fault in NMI context and we > don't have to care about the fact that IRET from the fault handler might > cause NMI nesting. > > This warning has already been removed from 32bit implementation of > vmalloc_fault() in 6863ea0cda8 ("x86/mm: Remove in_nmi() warning from > vmalloc_fault()"), but 64bit version was omitted. > > Remove the bogus warning also from 64bit implementation of vmalloc_fault(). Cute; did you actually trigger this? > Fixes: 6863ea0cda8 ("x86/mm: Remove in_nmi() warning from vmalloc_fault()") > Reported-by: Nicolai Stange > Signed-off-by: Jiri Kosina Acked-by: Peter Zijlstra (Intel) > --- > arch/x86/mm/fault.c | 2 -- > 1 file changed, 2 deletions(-) > > diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c > index 667f1da36208..5eaf67e8314f 100644 > --- a/arch/x86/mm/fault.c > +++ b/arch/x86/mm/fault.c > @@ -359,8 +359,6 @@ static noinline int vmalloc_fault(unsigned long address) > if (!(address >= VMALLOC_START && address < VMALLOC_END)) > return -1; > > - WARN_ON_ONCE(in_nmi()); > - > /* > * Copy kernel mappings over when needed. This can also > * happen within a race in page table update. In the later > > -- > Jiri Kosina > SUSE Labs >