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=-7.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 336F6C433DF for ; Fri, 7 Aug 2020 06:19:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 15EB62177B for ; Fri, 7 Aug 2020 06:19:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1596781184; bh=7QtTJ3FPkWRiiCZlJHLjLumqsLmAtsFK+JAWD/dAsXE=; h=Date:From:To:Subject:In-Reply-To:Reply-To:List-ID:From; b=EVQ6CttJzTYxTheH7922hn2GEd8P1idy+WWhY479KjOkuCjquwIgwwX1/H2va6f2c KgnnWtgrBQsUL0TAkD9WjwROijxpRYQYVSq2Y0pfybCoxHIygJxMqSj8/yRlQWiEkH cESFmuRPT+mUalBelGIl27qYJS65eeC5TcKGw7Ds= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725845AbgHGGTn (ORCPT ); Fri, 7 Aug 2020 02:19:43 -0400 Received: from mail.kernel.org ([198.145.29.99]:55460 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725379AbgHGGTn (ORCPT ); Fri, 7 Aug 2020 02:19:43 -0400 Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id AB518221E5; Fri, 7 Aug 2020 06:19:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1596781183; bh=7QtTJ3FPkWRiiCZlJHLjLumqsLmAtsFK+JAWD/dAsXE=; h=Date:From:To:Subject:In-Reply-To:From; b=OV2wbO+3Xctd4TWvlscu5Vg0/Ysevl1jQb1nI5V/FNontVotj5j5tNhcLm8MUWzaQ zjTRJs7aL0De4V1KL62xN/+PS9+1Xkm+6iJ6NIoFUHxakEN6KyJLUX9HxDeRThzySn 0bCuuUfHZWyW4P6Rej4tbCfiFAn/unSErQHYOPlo= Date: Thu, 06 Aug 2020 23:19:42 -0700 From: Andrew Morton To: akpm@linux-foundation.org, jhubbard@nvidia.com, kirill@shutemov.name, linux-mm@kvack.org, mm-commits@vger.kernel.org, rppt@linux.ibm.com, torvalds@linux-foundation.org, vbabka@suse.cz, william.kucharski@oracle.com, willy@infradead.org Subject: [patch 047/163] mm/debug: switch dump_page to get_kernel_nofault Message-ID: <20200807061942.vp2ZT_bvM%akpm@linux-foundation.org> In-Reply-To: <20200806231643.a2711a608dd0f18bff2caf2b@linux-foundation.org> User-Agent: s-nail v14.8.16 Sender: mm-commits-owner@vger.kernel.org Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org From: "Matthew Wilcox (Oracle)" Subject: mm/debug: switch dump_page to get_kernel_nofault This is simpler to use than copy_from_kernel_nofault(). Also make some of the related error messages less verbose. Link: http://lkml.kernel.org/r/20200709202117.7216-5-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Acked-by: Mike Rapoport Acked-by: Vlastimil Babka Cc: John Hubbard Cc: "Kirill A. Shutemov" Cc: William Kucharski Signed-off-by: Andrew Morton --- mm/debug.c | 36 ++++++++++++++++-------------------- 1 file changed, 16 insertions(+), 20 deletions(-) --- a/mm/debug.c~mm-switch-dump_page-to-get_kernel_nofault +++ a/mm/debug.c @@ -115,54 +115,50 @@ void __dump_page(struct page *page, cons else if (PageAnon(page)) type = "anon "; else if (mapping) { - const struct inode *host; + struct inode *host; const struct address_space_operations *a_ops; - const struct hlist_node *dentry_first; - const struct dentry *dentry_ptr; + struct hlist_node *dentry_first; + struct dentry *dentry_ptr; struct dentry dentry; /* * mapping can be invalid pointer and we don't want to crash * accessing it, so probe everything depending on it carefully */ - if (copy_from_kernel_nofault(&host, &mapping->host, - sizeof(struct inode *)) || - copy_from_kernel_nofault(&a_ops, &mapping->a_ops, - sizeof(struct address_space_operations *))) { - pr_warn("failed to read mapping->host or a_ops, mapping not a valid kernel address?\n"); + if (get_kernel_nofault(host, &mapping->host) || + get_kernel_nofault(a_ops, &mapping->a_ops)) { + pr_warn("failed to read mapping contents, not a valid kernel address?\n"); goto out_mapping; } if (!host) { - pr_warn("mapping->a_ops:%ps\n", a_ops); + pr_warn("aops:%ps\n", a_ops); goto out_mapping; } - if (copy_from_kernel_nofault(&dentry_first, - &host->i_dentry.first, sizeof(struct hlist_node *))) { - pr_warn("mapping->a_ops:%ps with invalid mapping->host inode address %px\n", - a_ops, host); + if (get_kernel_nofault(dentry_first, &host->i_dentry.first)) { + pr_warn("aops:%ps with invalid host inode %px\n", + a_ops, host); goto out_mapping; } if (!dentry_first) { - pr_warn("mapping->a_ops:%ps\n", a_ops); + pr_warn("aops:%ps\n", a_ops); goto out_mapping; } dentry_ptr = container_of(dentry_first, struct dentry, d_u.d_alias); - if (copy_from_kernel_nofault(&dentry, dentry_ptr, - sizeof(struct dentry))) { - pr_warn("mapping->aops:%ps with invalid mapping->host->i_dentry.first %px\n", - a_ops, dentry_ptr); + if (get_kernel_nofault(dentry, dentry_ptr)) { + pr_warn("aops:%ps with invalid dentry %px\n", a_ops, + dentry_ptr); } else { /* * if dentry is corrupted, the %pd handler may still * crash, but it's unlikely that we reach here with a * corrupted struct page */ - pr_warn("mapping->aops:%ps dentry name:\"%pd\"\n", - a_ops, &dentry); + pr_warn("aops:%ps dentry name:\"%pd\"\n", a_ops, + &dentry); } } out_mapping: _