From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935492Ab1KJEum (ORCPT ); Wed, 9 Nov 2011 23:50:42 -0500 Received: from cantor2.suse.de ([195.135.220.15]:43051 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935309Ab1KJDcg (ORCPT ); Wed, 9 Nov 2011 22:32:36 -0500 X-Mailbox-Line: From gregkh@clark.kroah.org Wed Nov 9 13:27:23 2011 Message-Id: <20111109212723.827480522@clark.kroah.org> User-Agent: quilt/0.48-16.4 Date: Wed, 09 Nov 2011 13:29:13 -0800 From: Greg KH To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Anton Blanchard , Benjamin Herrenschmidt Subject: [231/262] powerpc: Fix oops when echoing bad values to /sys/devices/system/memory/probe In-Reply-To: <20111109212847.GA20838@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: Anton Blanchard commit a11940978bd598e65996b4f807cf4904793f7025 upstream. If we echo an address the hypervisor doesn't like to /sys/devices/system/memory/probe we oops the box: # echo 0x10000000000 > /sys/devices/system/memory/probe kernel BUG at arch/powerpc/mm/hash_utils_64.c:541! The backtrace is: create_section_mapping arch_add_memory add_memory memory_probe_store sysdev_class_store sysfs_write_file vfs_write SyS_write In create_section_mapping we BUG if htab_bolt_mapping returned an error. A better approach is to return an error which will propagate back to userspace. Rerunning the test with this patch applied: # echo 0x10000000000 > /sys/devices/system/memory/probe -bash: echo: write error: Invalid argument Signed-off-by: Anton Blanchard Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/include/asm/sparsemem.h | 2 +- arch/powerpc/mm/hash_utils_64.c | 6 +++--- arch/powerpc/mm/mem.c | 3 ++- 3 files changed, 6 insertions(+), 5 deletions(-) --- a/arch/powerpc/include/asm/sparsemem.h +++ b/arch/powerpc/include/asm/sparsemem.h @@ -16,7 +16,7 @@ #endif /* CONFIG_SPARSEMEM */ #ifdef CONFIG_MEMORY_HOTPLUG -extern void create_section_mapping(unsigned long start, unsigned long end); +extern int create_section_mapping(unsigned long start, unsigned long end); extern int remove_section_mapping(unsigned long start, unsigned long end); #ifdef CONFIG_NUMA extern int hot_add_scn_to_nid(unsigned long scn_addr); --- a/arch/powerpc/mm/hash_utils_64.c +++ b/arch/powerpc/mm/hash_utils_64.c @@ -534,11 +534,11 @@ static unsigned long __init htab_get_tab } #ifdef CONFIG_MEMORY_HOTPLUG -void create_section_mapping(unsigned long start, unsigned long end) +int create_section_mapping(unsigned long start, unsigned long end) { - BUG_ON(htab_bolt_mapping(start, end, __pa(start), + return htab_bolt_mapping(start, end, __pa(start), pgprot_val(PAGE_KERNEL), mmu_linear_psize, - mmu_kernel_ssize)); + mmu_kernel_ssize); } int remove_section_mapping(unsigned long start, unsigned long end) --- a/arch/powerpc/mm/mem.c +++ b/arch/powerpc/mm/mem.c @@ -123,7 +123,8 @@ int arch_add_memory(int nid, u64 start, pgdata = NODE_DATA(nid); start = (unsigned long)__va(start); - create_section_mapping(start, start + size); + if (create_section_mapping(start, start + size)) + return -EINVAL; /* this should work for most non-highmem platforms */ zone = pgdata->node_zones;