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=-2.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 CA6A9C76186 for ; Wed, 24 Jul 2019 01:38:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 97D1B2238C for ; Wed, 24 Jul 2019 01:38:45 +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="RULrgcX4" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728359AbfGXBio (ORCPT ); Tue, 23 Jul 2019 21:38:44 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:57932 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727363AbfGXBio (ORCPT ); Tue, 23 Jul 2019 21:38:44 -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=AFwPz9F7BR2KO7EHQe4D2tuUr0dHyiHUKqAqUScb/5k=; b=RULrgcX43IxPsdqZAr6lzCNtc zncXOGdm5at73wpugQrjVm/0D5jAFMwnWKMKvNEA4wlnwbE6pgoawegICLrGsEQBv3zxPp/3b/kuy irE/ozw1NZOQwzdR1gpTm0V1AtY6m0TW83pVr89t+9aWKmjX7SJCi7nfKmLroTQsKWOB+LVwEItZC qlFd1a/r5p9/fZ+bovKzNcmCrBIXwIgFiTVdaetrzDdeLU1VPV7tJXwY4XA7Gr5jj19De7QnjImV2 +emEkD2xFmY7RB4rzv8jQmLp24bAE5Y8MPNZ8EYASJsS1q40hA7KT+nJarwSVQNPfOCF6U0kNje1W SSuCf5tTg==; Received: from willy by bombadil.infradead.org with local (Exim 4.92 #3 (Red Hat Linux)) id 1hq6Eq-0008Ul-UO; Wed, 24 Jul 2019 01:38:40 +0000 Date: Tue, 23 Jul 2019 18:38:40 -0700 From: Matthew Wilcox To: Jane Chu Cc: n-horiguchi@ah.jp.nec.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-nvdimm@lists.01.org Subject: Re: [PATCH] mm/memory-failure: Poison read receives SIGKILL instead of SIGBUS if mmaped more than once Message-ID: <20190724013840.GS363@bombadil.infradead.org> References: <1563925110-19359-1-git-send-email-jane.chu@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1563925110-19359-1-git-send-email-jane.chu@oracle.com> User-Agent: Mutt/1.11.4 (2019-03-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jul 23, 2019 at 05:38:30PM -0600, Jane Chu wrote: > @@ -331,16 +330,21 @@ static void add_to_kill(struct task_struct *tsk, struct page *p, > tk->size_shift = compound_order(compound_head(p)) + PAGE_SHIFT; > > /* > - * In theory we don't have to kill when the page was > - * munmaped. But it could be also a mremap. Since that's > - * likely very rare kill anyways just out of paranoia, but use > - * a SIGKILL because the error is not contained anymore. > + * Indeed a page could be mmapped N times within a process. And it's possible You should run this patch through checkpatch.pl so I don't have to tell you whats wrong with the trivial aspects of it ;-)