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=-8.5 required=3.0 tests=INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, 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 E3D63C3A5A2 for ; Tue, 3 Sep 2019 13:12:51 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id B9D822341E for ; Tue, 3 Sep 2019 13:12:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B9D822341E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 154926B0003; Tue, 3 Sep 2019 09:12:51 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 105F96B0005; Tue, 3 Sep 2019 09:12:51 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 043306B0006; Tue, 3 Sep 2019 09:12:50 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0061.hostedemail.com [216.40.44.61]) by kanga.kvack.org (Postfix) with ESMTP id D45A66B0003 for ; Tue, 3 Sep 2019 09:12:50 -0400 (EDT) Received: from smtpin21.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with SMTP id 68731824CA35 for ; Tue, 3 Sep 2019 13:12:50 +0000 (UTC) X-FDA: 75893649300.21.book43_35d977ad43657 X-HE-Tag: book43_35d977ad43657 X-Filterd-Recvd-Size: 2341 Received: from mx1.suse.de (mx2.suse.de [195.135.220.15]) by imf45.hostedemail.com (Postfix) with ESMTP for ; Tue, 3 Sep 2019 13:12:49 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 6DFE6AF38; Tue, 3 Sep 2019 13:12:47 +0000 (UTC) Date: Tue, 3 Sep 2019 15:12:46 +0200 From: Michal Hocko To: Kefeng Wang Cc: linux-mm@kvack.org, Andrew Morton Subject: Re: [PATCH] mm: do not hash address in print_bad_pte() Message-ID: <20190903131246.GX14028@dhcp22.suse.cz> References: <20190831011816.141002-1-wangkefeng.wang@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190831011816.141002-1-wangkefeng.wang@huawei.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Sat 31-08-19 09:18:16, Kefeng Wang wrote: > Using %px to show the actual address in print_bad_pte() > to help us to debug issue. Yes, those values are of no use when hashed. At least __dump_page prints mapping directly so there is no reason to differ here. anon_vma doesn't really disclose much more AFAICS. Printing the addr might disclose randomization offset for a vma but process usually doesn't live for long after a bad pte is detected so it should be reasonably safe unless I miss something > Signed-off-by: Kefeng Wang Acked-by: Michal Hocko > --- > mm/memory.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/memory.c b/mm/memory.c > index e2bb51b6242e..3f0874c9ca38 100644 > --- a/mm/memory.c > +++ b/mm/memory.c > @@ -518,7 +518,7 @@ static void print_bad_pte(struct vm_area_struct *vma, unsigned long addr, > (long long)pte_val(pte), (long long)pmd_val(*pmd)); > if (page) > dump_page(page, "bad pte"); > - pr_alert("addr:%p vm_flags:%08lx anon_vma:%p mapping:%p index:%lx\n", > + pr_alert("addr:%px vm_flags:%08lx anon_vma:%px mapping:%px index:%lx\n", > (void *)addr, vma->vm_flags, vma->anon_vma, mapping, index); > pr_alert("file:%pD fault:%ps mmap:%ps readpage:%ps\n", > vma->vm_file, > -- > 2.20.1 > -- Michal Hocko SUSE Labs