From patchwork Sun Nov 21 12:10:56 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Wilcox X-Patchwork-Id: 12630755 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E16A9C433F5 for ; Sun, 21 Nov 2021 12:12:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237957AbhKUMPn (ORCPT ); Sun, 21 Nov 2021 07:15:43 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37168 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235783AbhKUMPn (ORCPT ); Sun, 21 Nov 2021 07:15:43 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 13226C061574 for ; Sun, 21 Nov 2021 04:12:37 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:MIME-Version: Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To:Content-Type:Content-ID: Content-Description:In-Reply-To:References; bh=ouYiQ9fnPFu7NekPPdm7DFBi+ugK3ZRRR9rHUiq0t4k=; b=fXIE7e4hsOcVU/pG1gGnX7PW3F yANf8yBK3y9rtbu5JLWuhg/w+i1F3OjkJOhb29AVb6ov7JDNsfhkIYFRude51+jjkCyzQEqOzNIbN UlyXL+4BVqtLztNs1ZhLMTY6IXXT8LLWLyVuV/IQN0PifaSe6zcVtB1AQfMOe2wun7E0xhCU4YIu4 HhGGfc0z39yaWyQFOfIIYcUx1iVyfPpEoBLahfyfN3nLdKLEpjmU7g9nV08QLDlnRhtKNyJForz+W CNpTg/k+YzuQ40spr1nzPB2+T3g7r3uryOH8QaoUeEzgrVyXL4P2fPT7xLgGDr+ZAdhbVbrce45sv AogJ6fWw==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1molhx-00C2fn-Em; Sun, 21 Nov 2021 12:12:33 +0000 From: "Matthew Wilcox (Oracle)" To: Andrew Morton Cc: "Matthew Wilcox (Oracle)" , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, Vlastimil Babka , Michal Hocko Subject: [PATCH] mm,fs: Split dump_mapping() out from dump_page() Date: Sun, 21 Nov 2021 12:10:56 +0000 Message-Id: <20211121121056.2870061-1-willy@infradead.org> X-Mailer: git-send-email 2.31.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org dump_mapping() is a big chunk of dump_page(), and it'd be handy to be able to call it when we don't have a struct page. Split it out and move it to fs/inode.c. Take the opportunity to simplify some of the debug messages a little. Signed-off-by: Matthew Wilcox (Oracle) Acked-by: Michal Hocko Reviewed-by: William Kucharski --- fs/inode.c | 49 +++++++++++++++++++++++++++++++++++++++++++ include/linux/fs.h | 1 + mm/debug.c | 52 ++-------------------------------------------- 3 files changed, 52 insertions(+), 50 deletions(-) diff --git a/fs/inode.c b/fs/inode.c index bdfbd5962f2b..67758b2b702f 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -522,6 +522,55 @@ void __remove_inode_hash(struct inode *inode) } EXPORT_SYMBOL(__remove_inode_hash); +void dump_mapping(const struct address_space *mapping) +{ + struct inode *host; + const struct address_space_operations *a_ops; + struct hlist_node *dentry_first; + struct dentry *dentry_ptr; + struct dentry dentry; + unsigned long ino; + + /* + * If mapping is an invalid pointer, we don't want to crash + * accessing it, so probe everything depending on it carefully. + */ + if (get_kernel_nofault(host, &mapping->host) || + get_kernel_nofault(a_ops, &mapping->a_ops)) { + pr_warn("invalid mapping:%px\n", mapping); + return; + } + + if (!host) { + pr_warn("aops:%ps\n", a_ops); + return; + } + + if (get_kernel_nofault(dentry_first, &host->i_dentry.first) || + get_kernel_nofault(ino, &host->i_ino)) { + pr_warn("aops:%ps invalid inode:%px\n", a_ops, host); + return; + } + + if (!dentry_first) { + pr_warn("aops:%ps ino:%lx\n", a_ops, ino); + return; + } + + dentry_ptr = container_of(dentry_first, struct dentry, d_u.d_alias); + if (get_kernel_nofault(dentry, dentry_ptr)) { + pr_warn("aops:%ps ino:%lx invalid dentry:%px\n", + a_ops, ino, dentry_ptr); + return; + } + + /* + * if dentry is corrupted, the %pd handler may still crash, + * but it's unlikely that we reach here with a corrupt mapping + */ + pr_warn("aops:%ps ino:%lx dentry name:\"%pd\"\n", a_ops, ino, &dentry); +} + void clear_inode(struct inode *inode) { /* diff --git a/include/linux/fs.h b/include/linux/fs.h index d6a4eb6cf825..acaad2b0d5b9 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -3149,6 +3149,7 @@ extern void unlock_new_inode(struct inode *); extern void discard_new_inode(struct inode *); extern unsigned int get_next_ino(void); extern void evict_inodes(struct super_block *sb); +void dump_mapping(const struct address_space *); /* * Userspace may rely on the the inode number being non-zero. For example, glibc diff --git a/mm/debug.c b/mm/debug.c index fae0f81ad831..b3ebfab21cb3 100644 --- a/mm/debug.c +++ b/mm/debug.c @@ -110,56 +110,8 @@ static void __dump_page(struct page *page) type = "ksm "; else if (PageAnon(page)) type = "anon "; - else if (mapping) { - struct inode *host; - const struct address_space_operations *a_ops; - struct hlist_node *dentry_first; - struct dentry *dentry_ptr; - struct dentry dentry; - unsigned long ino; - - /* - * mapping can be invalid pointer and we don't want to crash - * accessing it, so probe everything depending on it carefully - */ - 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("aops:%ps\n", a_ops); - goto out_mapping; - } - - if (get_kernel_nofault(dentry_first, &host->i_dentry.first) || - get_kernel_nofault(ino, &host->i_ino)) { - pr_warn("aops:%ps with invalid host inode %px\n", - a_ops, host); - goto out_mapping; - } - - if (!dentry_first) { - pr_warn("aops:%ps ino:%lx\n", a_ops, ino); - goto out_mapping; - } - - dentry_ptr = container_of(dentry_first, struct dentry, d_u.d_alias); - if (get_kernel_nofault(dentry, dentry_ptr)) { - pr_warn("aops:%ps ino:%lx with invalid dentry %px\n", - a_ops, ino, 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("aops:%ps ino:%lx dentry name:\"%pd\"\n", - a_ops, ino, &dentry); - } - } -out_mapping: + else if (mapping) + dump_mapping(mapping); BUILD_BUG_ON(ARRAY_SIZE(pageflag_names) != __NR_PAGEFLAGS + 1); pr_warn("%sflags: %#lx(%pGp)%s\n", type, head->flags, &head->flags,