From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753956Ab3FYTK5 (ORCPT ); Tue, 25 Jun 2013 15:10:57 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:40875 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751957Ab3FYSdj (ORCPT ); Tue, 25 Jun 2013 14:33:39 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Helge Deller Subject: [ 22/95] parisc: fix kernel BUG at arch/parisc/include/asm/mmzone.h:50 Date: Tue, 25 Jun 2013 11:32:09 -0700 Message-Id: <20130625182156.160754876@linuxfoundation.org> X-Mailer: git-send-email 1.8.3.rc0.20.gb99dd2e In-Reply-To: <20130625182153.605455184@linuxfoundation.org> References: <20130625182153.605455184@linuxfoundation.org> User-Agent: quilt/0.60-5.1.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Helge Deller commit ae249b5fa27f9fba25aa59664d4338efc2dd2394 upstream. With CONFIG_DISCONTIGMEM=y and multiple physical memory areas, cat /proc/kpageflags triggers this kernel bug: kernel BUG at arch/parisc/include/asm/mmzone.h:50! CPU: 2 PID: 7848 Comm: cat Tainted: G D W 3.10.0-rc3-64bit #44 IAOQ[0]: kpageflags_read0x128/0x238 IAOQ[1]: kpageflags_read0x12c/0x238 RP(r2): proc_reg_read0xbc/0x130 Backtrace: [<00000000402ca2d4>] proc_reg_read0xbc/0x130 [<0000000040235bcc>] vfs_read0xc4/0x1d0 [<0000000040235f0c>] SyS_read0x94/0xf0 [<0000000040105fc0>] syscall_exit0x0/0x14 kpageflags_read() walks through the whole memory, even if some memory areas are physically not available. So, we should better not BUG on an unavailable pfn in pfn_to_nid() but just return the expected value -1 or 0. Signed-off-by: Helge Deller Signed-off-by: Greg Kroah-Hartman --- arch/parisc/include/asm/mmzone.h | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) --- a/arch/parisc/include/asm/mmzone.h +++ b/arch/parisc/include/asm/mmzone.h @@ -39,17 +39,14 @@ extern unsigned char pfnnid_map[PFNNID_M static inline int pfn_to_nid(unsigned long pfn) { unsigned int i; - unsigned char r; if (unlikely(pfn_is_io(pfn))) return 0; i = pfn >> PFNNID_SHIFT; BUG_ON(i >= ARRAY_SIZE(pfnnid_map)); - r = pfnnid_map[i]; - BUG_ON(r == 0xff); - return (int)r; + return (int)pfnnid_map[i]; } static inline int pfn_valid(int pfn)