From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759374Ab0HKX7j (ORCPT ); Wed, 11 Aug 2010 19:59:39 -0400 Received: from kroah.org ([198.145.64.141]:43668 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759289Ab0HKX7R (ORCPT ); Wed, 11 Aug 2010 19:59:17 -0400 X-Mailbox-Line: From gregkh@clark.site Wed Aug 11 16:55:04 2010 Message-Id: <20100811235504.128853998@clark.site> User-Agent: quilt/0.48-11.2 Date: Wed, 11 Aug 2010 16:55:14 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Wu Fengguang , Andi Kleen , Thomas Renninger Subject: [093/111] HWPOISON: abort on failed unmap In-Reply-To: <20100811235623.GA24440@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.32-stable review patch. If anyone has any objections, please let us know. ------------------ From: Wu Fengguang commit 1668bfd5be9d8a52536c4865000fbbe065a3613b upstream. Don't try to isolate a still mapped page. Otherwise we will hit the BUG_ON(page_mapped(page)) in __remove_from_page_cache(). Signed-off-by: Wu Fengguang Signed-off-by: Andi Kleen Signed-off-by: Thomas Renninger Signed-off-by: Greg Kroah-Hartman --- mm/memory-failure.c | 20 +++++++++++++++----- 1 file changed, 15 insertions(+), 5 deletions(-) --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -637,7 +637,7 @@ static int page_action(struct page_state * Do all that is necessary to remove user space mappings. Unmap * the pages and send SIGBUS to the processes if the data was dirty. */ -static void hwpoison_user_mappings(struct page *p, unsigned long pfn, +static int hwpoison_user_mappings(struct page *p, unsigned long pfn, int trapno) { enum ttu_flags ttu = TTU_UNMAP | TTU_IGNORE_MLOCK | TTU_IGNORE_ACCESS; @@ -647,15 +647,18 @@ static void hwpoison_user_mappings(struc int i; int kill = 1; - if (PageReserved(p) || PageCompound(p) || PageSlab(p) || PageKsm(p)) - return; + if (PageReserved(p) || PageSlab(p)) + return SWAP_SUCCESS; /* * This check implies we don't kill processes if their pages * are in the swap cache early. Those are always late kills. */ if (!page_mapped(p)) - return; + return SWAP_SUCCESS; + + if (PageCompound(p) || PageKsm(p)) + return SWAP_FAIL; if (PageSwapCache(p)) { printk(KERN_ERR @@ -717,6 +720,8 @@ static void hwpoison_user_mappings(struc */ kill_procs_ao(&tokill, !!PageDirty(p), trapno, ret != SWAP_SUCCESS, pfn); + + return ret; } int __memory_failure(unsigned long pfn, int trapno, int ref) @@ -786,8 +791,13 @@ int __memory_failure(unsigned long pfn, /* * Now take care of user space mappings. + * Abort on fail: __remove_from_page_cache() assumes unmapped page. */ - hwpoison_user_mappings(p, pfn, trapno); + if (hwpoison_user_mappings(p, pfn, trapno) != SWAP_SUCCESS) { + printk(KERN_ERR "MCE %#lx: cannot unmap page, give up\n", pfn); + res = -EBUSY; + goto out; + } /* * Torn down by someone else?