From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail143.messagelabs.com (mail143.messagelabs.com [216.82.254.35]) by kanga.kvack.org (Postfix) with ESMTP id B9F3C6B0096 for ; Wed, 5 Aug 2009 05:36:48 -0400 (EDT) From: Andi Kleen References: <200908051136.682859934@firstfloor.org> In-Reply-To: <200908051136.682859934@firstfloor.org> Subject: [PATCH] [19/19] HWPOISON: Add simple debugfs interface to inject hwpoison on arbitary PFNs Message-Id: <20090805093646.EE6F0B15D8@basil.firstfloor.org> Date: Wed, 5 Aug 2009 11:36:46 +0200 (CEST) Sender: owner-linux-mm@kvack.org To: akpm@linux-foundation.org, npiggin@suse.de, linux-kernel@vger.kernel.org, linux-mm@kvack.org, fengguang.wu@intel.com, hidehiro.kawai.ez@hitachi.com List-ID: Useful for some testing scenarios, although specific testing is often done better through MADV_POISON This can be done with the x86 level MCE injector too, but this interface allows it to do independently from low level x86 changes. Open issues: Should be disabled for cgroups. Signed-off-by: Andi Kleen --- mm/Kconfig | 6 +++++- mm/Makefile | 1 + mm/hwpoison-inject.c | 40 ++++++++++++++++++++++++++++++++++++++++ mm/madvise.c | 2 +- 4 files changed, 47 insertions(+), 2 deletions(-) Index: linux/mm/hwpoison-inject.c =================================================================== --- /dev/null +++ linux/mm/hwpoison-inject.c @@ -0,0 +1,40 @@ +/* Inject a hwpoison memory failure on a arbitary pfn */ +#include +#include +#include +#include + +static struct dentry *hwpoison_dir, *corrupt_pfn; + +static int hwpoison_inject(void *data, u64 val) +{ + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + printk(KERN_INFO "Injecting memory failure at pfn %Lx\n", val); + return __memory_failure(val, 18, 0); +} + +DEFINE_SIMPLE_ATTRIBUTE(hwpoison_fops, NULL, hwpoison_inject, "%lli\n"); + +static void pfn_inject_exit(void) +{ + if (hwpoison_dir) + debugfs_remove_recursive(hwpoison_dir); +} + +static int pfn_inject_init(void) +{ + hwpoison_dir = debugfs_create_dir("hwpoison", NULL); + if (hwpoison_dir == NULL) + return -ENOMEM; + corrupt_pfn = debugfs_create_file("corrupt-pfn", 0600, hwpoison_dir, + NULL, &hwpoison_fops); + if (corrupt_pfn == NULL) { + pfn_inject_exit(); + return -ENOMEM; + } + return 0; +} + +module_init(pfn_inject_init); +module_exit(pfn_inject_exit); Index: linux/mm/Kconfig =================================================================== --- linux.orig/mm/Kconfig +++ linux/mm/Kconfig @@ -236,12 +236,16 @@ config DEFAULT_MMAP_MIN_ADDR config MEMORY_FAILURE depends on MMU depends on X86_MCE - bool "Enable memory failure recovery" + bool "Enable recovery from hardware memory errors" help Enables code to recover from some memory failures on systems with MCA recovery. This allows a system to continue running even when some of its memory has uncorrected errors. +config HWPOISON_INJECT + tristate "Poison pages injector" + depends on MEMORY_FAILURE && DEBUG_KERNEL + config NOMMU_INITIAL_TRIM_EXCESS int "Turn on mmap() excess space trimming before booting" depends on !MMU Index: linux/mm/Makefile =================================================================== --- linux.orig/mm/Makefile +++ linux/mm/Makefile @@ -41,5 +41,6 @@ endif obj-$(CONFIG_QUICKLIST) += quicklist.o obj-$(CONFIG_CGROUP_MEM_RES_CTLR) += memcontrol.o page_cgroup.o obj-$(CONFIG_MEMORY_FAILURE) += memory-failure.o +obj-$(CONFIG_HWPOISON_INJECT) += hwpoison-inject.o obj-$(CONFIG_DEBUG_KMEMLEAK) += kmemleak.o obj-$(CONFIG_DEBUG_KMEMLEAK_TEST) += kmemleak-test.o Index: linux/mm/madvise.c =================================================================== --- linux.orig/mm/madvise.c +++ linux/mm/madvise.c @@ -213,7 +213,7 @@ static long madvise_remove(struct vm_are */ static int madvise_hwpoison(unsigned long start, unsigned long end) { - int ret = -EIO; + int ret = 0; /* * RED-PEN * This allows to tie up arbitary amounts of memory. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org