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=-8.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 7E71DC43331 for ; Fri, 6 Sep 2019 10:44:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 55D2C207FC for ; Fri, 6 Sep 2019 10:44:00 +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="bVexAHVx" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733159AbfIFKn7 (ORCPT ); Fri, 6 Sep 2019 06:43:59 -0400 Received: from merlin.infradead.org ([205.233.59.134]:52688 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728218AbfIFKn7 (ORCPT ); Fri, 6 Sep 2019 06:43:59 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.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=uDVMSGf1AOvcOHnkrMI95vWCK7Pdvk5wBh0T9EQX0Ko=; b=bVexAHVxWdRsKDWXY577j+0eM QMU4F5MtSeIFyzH1R+vfsFtE3sJ2K7fHQVVr2/p9sOuFhExyUgRgwwhWOZg1LpNCnJJ7+9GYceEyq RqG2ZWHJmPxTJ4xi8SKw5+8G5zyoTal8/6RS+M5c3Wl/BVwBTmbKaKLGKun40PK1Gn+FZMqq+tfFD n8UhYPbvVNq4prd5/JXb6ZsPFnrOVd6LIY5ptD+NukfEYP2n/+1mfyp27rUUeXlhbYbHllRzpXDLb PZMwDt7F8899XDJ6H/v8KnQHMjTwegfkdVn6TnCxnPgYhHxw8jNJrjd54ltPfXoUI+Uf6mDt6qyFB hY/KQPhRQ==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92 #3 (Red Hat Linux)) id 1i6BiR-0006Kj-GL; Fri, 06 Sep 2019 10:43:43 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 28E1C306023; Fri, 6 Sep 2019 12:43:04 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 8900129E2C33C; Fri, 6 Sep 2019 12:43:41 +0200 (CEST) Date: Fri, 6 Sep 2019 12:43:41 +0200 From: Peter Zijlstra To: Greg KH Cc: Austin Kim , tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org, dvhart@infradead.org, andy@infradead.org, hpa@zytor.com, allison@lohutok.net, armijn@tjaldur.nl, kjlu@umn.edu, platform-driver-x86@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] x86/platform/uv: move kmalloc() NULL check routine Message-ID: <20190906104341.GW2349@hirez.programming.kicks-ass.net> References: <20190905232951.GA28779@LGEARND20B15> <20190906093252.GB16843@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190906093252.GB16843@kroah.com> 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 Fri, Sep 06, 2019 at 11:32:52AM +0200, Greg KH wrote: > On Fri, Sep 06, 2019 at 08:29:51AM +0900, Austin Kim wrote: > > The result of kmalloc should have been checked ahead of below statement: > > pqp = (struct bau_pq_entry *)vp; > > > > Move BUG_ON(!vp) before above statement. > > > > Signed-off-by: Austin Kim > > --- > > arch/x86/platform/uv/tlb_uv.c | 4 ++-- > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > diff --git a/arch/x86/platform/uv/tlb_uv.c b/arch/x86/platform/uv/tlb_uv.c > > index 20c389a..5f0a96bf 100644 > > --- a/arch/x86/platform/uv/tlb_uv.c > > +++ b/arch/x86/platform/uv/tlb_uv.c > > @@ -1804,9 +1804,9 @@ static void pq_init(int node, int pnode) > > > > plsize = (DEST_Q_SIZE + 1) * sizeof(struct bau_pq_entry); > > vp = kmalloc_node(plsize, GFP_KERNEL, node); > > - pqp = (struct bau_pq_entry *)vp; > > - BUG_ON(!pqp); > > + BUG_ON(!vp); > > Ick! Don't crash the whole machine if you are out of memory, that's a > totally lazy and broken driver. Fix this up properly please. This is boot time init; if memory allocation fails, we're in trouble, no way forward no way back. It is not uncommon to have BUG_ON() for alloc failing during boot. > But the original code is just fine (from a this is doing what I want it > to do point of view), I don't see the need to change anything here, you > did not modify any logic at all. Agreed, the patch seems entirely pointless.