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-rw-r--r--Documentation/ABI/testing/sysfs-memory-page-offline44
-rw-r--r--Documentation/vm/hwpoison.txt52
-rw-r--r--Documentation/vm/page-types.c15
-rw-r--r--MAINTAINERS9
-rw-r--r--drivers/base/memory.c61
-rw-r--r--fs/proc/page.c45
-rw-r--r--include/asm-generic/mman-common.h1
-rw-r--r--include/linux/kernel-page-flags.h46
-rw-r--r--include/linux/memcontrol.h13
-rw-r--r--include/linux/mm.h8
-rw-r--r--include/linux/page-flags.h4
-rw-r--r--mm/Kconfig3
-rw-r--r--mm/hwpoison-inject.c113
-rw-r--r--mm/internal.h12
-rw-r--r--mm/madvise.c21
-rw-r--r--mm/memcontrol.c16
-rw-r--r--mm/memory-failure.c560
-rw-r--r--mm/memory.c4
-rw-r--r--mm/page_alloc.c21
19 files changed, 922 insertions, 126 deletions
diff --git a/Documentation/ABI/testing/sysfs-memory-page-offline b/Documentation/ABI/testing/sysfs-memory-page-offline
new file mode 100644
index 0000000..e14703f
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-memory-page-offline
@@ -0,0 +1,44 @@
+What: /sys/devices/system/memory/soft_offline_page
+Date: Sep 2009
+KernelVersion: 2.6.33
+Contact: andi@firstfloor.org
+Description:
+ Soft-offline the memory page containing the physical address
+ written into this file. Input is a hex number specifying the
+ physical address of the page. The kernel will then attempt
+ to soft-offline it, by moving the contents elsewhere or
+ dropping it if possible. The kernel will then be placed
+ on the bad page list and never be reused.
+
+ The offlining is done in kernel specific granuality.
+ Normally it's the base page size of the kernel, but
+ this might change.
+
+ The page must be still accessible, not poisoned. The
+ kernel will never kill anything for this, but rather
+ fail the offline. Return value is the size of the
+ number, or a error when the offlining failed. Reading
+ the file is not allowed.
+
+What: /sys/devices/system/memory/hard_offline_page
+Date: Sep 2009
+KernelVersion: 2.6.33
+Contact: andi@firstfloor.org
+Description:
+ Hard-offline the memory page containing the physical
+ address written into this file. Input is a hex number
+ specifying the physical address of the page. The
+ kernel will then attempt to hard-offline the page, by
+ trying to drop the page or killing any owner or
+ triggering IO errors if needed. Note this may kill
+ any processes owning the page. The kernel will avoid
+ to access this page assuming it's poisoned by the
+ hardware.
+
+ The offlining is done in kernel specific granuality.
+ Normally it's the base page size of the kernel, but
+ this might change.
+
+ Return value is the size of the number, or a error when
+ the offlining failed.
+ Reading the file is not allowed.
diff --git a/Documentation/vm/hwpoison.txt b/Documentation/vm/hwpoison.txt
index 3ffadf8..12f9ba2 100644
--- a/Documentation/vm/hwpoison.txt
+++ b/Documentation/vm/hwpoison.txt
@@ -92,16 +92,62 @@ PR_MCE_KILL_GET
Testing:
-madvise(MADV_POISON, ....)
+madvise(MADV_HWPOISON, ....)
(as root)
Poison a page in the process for testing
hwpoison-inject module through debugfs
- /sys/debug/hwpoison/corrupt-pfn
-Inject hwpoison fault at PFN echoed into this file
+/sys/debug/hwpoison/
+corrupt-pfn
+
+Inject hwpoison fault at PFN echoed into this file. This does
+some early filtering to avoid corrupted unintended pages in test suites.
+
+unpoison-pfn
+
+Software-unpoison page at PFN echoed into this file. This
+way a page can be reused again.
+This only works for Linux injected failures, not for real
+memory failures.
+
+Note these injection interfaces are not stable and might change between
+kernel versions
+
+corrupt-filter-dev-major
+corrupt-filter-dev-minor
+
+Only handle memory failures to pages associated with the file system defined
+by block device major/minor. -1U is the wildcard value.
+This should be only used for testing with artificial injection.
+
+corrupt-filter-memcg
+
+Limit injection to pages owned by memgroup. Specified by inode number
+of the memcg.
+
+Example:
+ mkdir /cgroup/hwpoison
+
+ usemem -m 100 -s 1000 &
+ echo `jobs -p` > /cgroup/hwpoison/tasks
+
+ memcg_ino=$(ls -id /cgroup/hwpoison | cut -f1 -d' ')
+ echo $memcg_ino > /debug/hwpoison/corrupt-filter-memcg
+
+ page-types -p `pidof init` --hwpoison # shall do nothing
+ page-types -p `pidof usemem` --hwpoison # poison its pages
+
+corrupt-filter-flags-mask
+corrupt-filter-flags-value
+
+When specified, only poison pages if ((page_flags & mask) == value).
+This allows stress testing of many kinds of pages. The page_flags
+are the same as in /proc/kpageflags. The flag bits are defined in
+include/linux/kernel-page-flags.h and documented in
+Documentation/vm/pagemap.txt
Architecture specific MCE injector
diff --git a/Documentation/vm/page-types.c b/Documentation/vm/page-types.c
index 7a7d9ba..66e9358 100644
--- a/Documentation/vm/page-types.c
+++ b/Documentation/vm/page-types.c
@@ -1,11 +1,22 @@
/*
* page-types: Tool for querying page flags
*
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; version 2.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should find a copy of v2 of the GNU General Public License somewhere on
+ * your Linux system; if not, write to the Free Software Foundation, Inc., 59
+ * Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ *
* Copyright (C) 2009 Intel corporation
*
* Authors: Wu Fengguang <fengguang.wu@intel.com>
- *
- * Released under the General Public License (GPL).
*/
#define _LARGEFILE64_SOURCE
diff --git a/MAINTAINERS b/MAINTAINERS
index d6a2711..0699782 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2377,6 +2377,15 @@ W: http://www.kernel.org/pub/linux/kernel/people/fseidel/hdaps/
S: Maintained
F: drivers/hwmon/hdaps.c
+HWPOISON MEMORY FAILURE HANDLING
+M: Andi Kleen <andi@firstfloor.org>
+L: linux-mm@kvack.org
+L: linux-kernel@vger.kernel.org
+T: git git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6.git hwpoison
+S: Maintained
+F: mm/memory-failure.c
+F: mm/hwpoison-inject.c
+
HYPERVISOR VIRTUAL CONSOLE DRIVER
L: linuxppc-dev@ozlabs.org
S: Odd Fixes
diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index 989429c..c4c8f2e 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -341,6 +341,64 @@ static inline int memory_probe_init(void)
}
#endif
+#ifdef CONFIG_MEMORY_FAILURE
+/*
+ * Support for offlining pages of memory
+ */
+
+/* Soft offline a page */
+static ssize_t
+store_soft_offline_page(struct class *class, const char *buf, size_t count)
+{
+ int ret;
+ u64 pfn;
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+ if (strict_strtoull(buf, 0, &pfn) < 0)
+ return -EINVAL;
+ pfn >>= PAGE_SHIFT;
+ if (!pfn_valid(pfn))
+ return -ENXIO;
+ ret = soft_offline_page(pfn_to_page(pfn), 0);
+ return ret == 0 ? count : ret;
+}
+
+/* Forcibly offline a page, including killing processes. */
+static ssize_t
+store_hard_offline_page(struct class *class, const char *buf, size_t count)
+{
+ int ret;
+ u64 pfn;
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+ if (strict_strtoull(buf, 0, &pfn) < 0)
+ return -EINVAL;
+ pfn >>= PAGE_SHIFT;
+ ret = __memory_failure(pfn, 0, 0);
+ return ret ? ret : count;
+}
+
+static CLASS_ATTR(soft_offline_page, 0644, NULL, store_soft_offline_page);
+static CLASS_ATTR(hard_offline_page, 0644, NULL, store_hard_offline_page);
+
+static __init int memory_fail_init(void)
+{
+ int err;
+
+ err = sysfs_create_file(&memory_sysdev_class.kset.kobj,
+ &class_attr_soft_offline_page.attr);
+ if (!err)
+ err = sysfs_create_file(&memory_sysdev_class.kset.kobj,
+ &class_attr_hard_offline_page.attr);
+ return err;
+}
+#else
+static inline int memory_fail_init(void)
+{
+ return 0;
+}
+#endif
+
/*
* Note that phys_device is optional. It is here to allow for
* differentiation between which *physical* devices each
@@ -473,6 +531,9 @@ int __init memory_dev_init(void)
err = memory_probe_init();
if (!ret)
ret = err;
+ err = memory_fail_init();
+ if (!ret)
+ ret = err;
err = block_size_init();
if (!ret)
ret = err;
diff --git a/fs/proc/page.c b/fs/proc/page.c
index 5033ce0..180cf5a 100644
--- a/fs/proc/page.c
+++ b/fs/proc/page.c
@@ -8,6 +8,7 @@
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/hugetlb.h>
+#include <linux/kernel-page-flags.h>
#include <asm/uaccess.h>
#include "internal.h"
@@ -71,52 +72,12 @@ static const struct file_operations proc_kpagecount_operations = {
* physical page flags.
*/
-/* These macros are used to decouple internal flags from exported ones */
-
-#define KPF_LOCKED 0
-#define KPF_ERROR 1
-#define KPF_REFERENCED 2
-#define KPF_UPTODATE 3
-#define KPF_DIRTY 4
-#define KPF_LRU 5
-#define KPF_ACTIVE 6
-#define KPF_SLAB 7
-#define KPF_WRITEBACK 8
-#define KPF_RECLAIM 9
-#define KPF_BUDDY 10
-
-/* 11-20: new additions in 2.6.31 */
-#define KPF_MMAP 11
-#define KPF_ANON 12
-#define KPF_SWAPCACHE 13
-#define KPF_SWAPBACKED 14
-#define KPF_COMPOUND_HEAD 15
-#define KPF_COMPOUND_TAIL 16
-#define KPF_HUGE 17
-#define KPF_UNEVICTABLE 18
-#define KPF_HWPOISON 19
-#define KPF_NOPAGE 20
-
-#define KPF_KSM 21
-
-/* kernel hacking assistances
- * WARNING: subject to change, never rely on them!
- */
-#define KPF_RESERVED 32
-#define KPF_MLOCKED 33
-#define KPF_MAPPEDTODISK 34
-#define KPF_PRIVATE 35
-#define KPF_PRIVATE_2 36
-#define KPF_OWNER_PRIVATE 37
-#define KPF_ARCH 38
-#define KPF_UNCACHED 39
-
static inline u64 kpf_copy_bit(u64 kflags, int ubit, int kbit)
{
return ((kflags >> kbit) & 1) << ubit;
}
-static u64 get_uflags(struct page *page)
+u64 stable_page_flags(struct page *page)
{
u64 k;
u64 u;
@@ -219,7 +180,7 @@ static ssize_t kpageflags_read(struct file *file, char __user *buf,
else
ppage = NULL;
- if (put_user(get_uflags(ppage), out)) {
+ if (put_user(stable_page_flags(ppage), out)) {
ret = -EFAULT;
break;
}
diff --git a/include/asm-generic/mman-common.h b/include/asm-generic/mman-common.h
index 2011126..3da9e27 100644
--- a/include/asm-generic/mman-common.h
+++ b/include/asm-generic/mman-common.h
@@ -40,6 +40,7 @@
#define MADV_DONTFORK 10 /* don't inherit across fork */
#define MADV_DOFORK 11 /* do inherit across fork */
#define MADV_HWPOISON 100 /* poison a page for testing */
+#define MADV_SOFT_OFFLINE 101 /* soft offline page for testing */
#define MADV_MERGEABLE 12 /* KSM may merge identical pages */
#define MADV_UNMERGEABLE 13 /* KSM may not merge identical pages */
diff --git a/include/linux/kernel-page-flags.h b/include/linux/kernel-page-flags.h
new file mode 100644
index 0000000..bd92a89
--- /dev/null
+++ b/include/linux/kernel-page-flags.h
@@ -0,0 +1,46 @@
+#ifndef LINUX_KERNEL_PAGE_FLAGS_H
+#define LINUX_KERNEL_PAGE_FLAGS_H
+
+/*
+ * Stable page flag bits exported to user space
+ */
+
+#define KPF_LOCKED 0
+#define KPF_ERROR 1
+#define KPF_REFERENCED 2
+#define KPF_UPTODATE 3
+#define KPF_DIRTY 4
+#define KPF_LRU 5
+#define KPF_ACTIVE 6
+#define KPF_SLAB 7
+#define KPF_WRITEBACK 8
+#define KPF_RECLAIM 9
+#define KPF_BUDDY 10
+
+/* 11-20: new additions in 2.6.31 */
+#define KPF_MMAP 11
+#define KPF_ANON 12
+#define KPF_SWAPCACHE 13
+#define KPF_SWAPBACKED 14
+#define KPF_COMPOUND_HEAD 15
+#define KPF_COMPOUND_TAIL 16
+#define KPF_HUGE 17
+#define KPF_UNEVICTABLE 18
+#define KPF_HWPOISON 19
+#define KPF_NOPAGE 20
+
+#define KPF_KSM 21
+
+/* kernel hacking assistances
+ * WARNING: subject to change, never rely on them!
+ */
+#define KPF_RESERVED 32
+#define KPF_MLOCKED 33
+#define KPF_MAPPEDTODISK 34
+#define KPF_PRIVATE 35
+#define KPF_PRIVATE_2 36
+#define KPF_OWNER_PRIVATE 37
+#define KPF_ARCH 38
+#define KPF_UNCACHED 39
+
+#endif /* LINUX_KERNEL_PAGE_FLAGS_H */
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 0b46c20..1f9b119 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -73,6 +73,7 @@ extern unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
extern void mem_cgroup_out_of_memory(struct mem_cgroup *mem, gfp_t gfp_mask);
int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem);
+extern struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page);
extern struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p);
static inline
@@ -85,6 +86,8 @@ int mm_match_cgroup(const struct mm_struct *mm, const struct mem_cgroup *cgroup)
return cgroup == mem;
}
+extern struct cgroup_subsys_state *mem_cgroup_css(struct mem_cgroup *mem);
+
extern int
mem_cgroup_prepare_migration(struct page *page, struct mem_cgroup **ptr);
extern void mem_cgroup_end_migration(struct mem_cgroup *mem,
@@ -202,6 +205,11 @@ mem_cgroup_move_lists(struct page *page, enum lru_list from, enum lru_list to)
{
}
+static inline struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page)
+{
+ return NULL;
+}
+
static inline int mm_match_cgroup(struct mm_struct *mm, struct mem_cgroup *mem)
{
return 1;
@@ -213,6 +221,11 @@ static inline int task_in_mem_cgroup(struct task_struct *task,
return 1;
}
+static inline struct cgroup_subsys_state *mem_cgroup_css(struct mem_cgroup *mem)
+{
+ return NULL;
+}
+
static inline int
mem_cgroup_prepare_migration(struct page *page, struct mem_cgroup **ptr)
{
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 9d65ae4..849b4a6 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1331,11 +1331,17 @@ extern int account_locked_memory(struct mm_struct *mm, struct rlimit *rlim,
size_t size);
extern void refund_locked_memory(struct mm_struct *mm, size_t size);
+enum mf_flags {
+ MF_COUNT_INCREASED = 1 << 0,
+};
extern void memory_failure(unsigned long pfn, int trapno);
-extern int __memory_failure(unsigned long pfn, int trapno, int ref);
+extern int __memory_failure(unsigned long pfn, int trapno, int flags);
+extern int unpoison_memory(unsigned long pfn);
extern int sysctl_memory_failure_early_kill;
extern int sysctl_memory_failure_recovery;
+extern void shake_page(struct page *p, int access);
extern atomic_long_t mce_bad_pages;
+extern int soft_offline_page(struct page *page, int flags);
#endif /* __KERNEL__ */
#endif /* _LINUX_MM_H */
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index 49e907b..feee2ba 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -275,13 +275,15 @@ PAGEFLAG_FALSE(Uncached)
#ifdef CONFIG_MEMORY_FAILURE
PAGEFLAG(HWPoison, hwpoison)
-TESTSETFLAG(HWPoison, hwpoison)
+TESTSCFLAG(HWPoison, hwpoison)
#define __PG_HWPOISON (1UL << PG_hwpoison)
#else
PAGEFLAG_FALSE(HWPoison)
#define __PG_HWPOISON 0
#endif
+u64 stable_page_flags(struct page *page);
+
static inline int PageUptodate(struct page *page)
{
int ret = test_bit(PG_uptodate, &(page)->flags);
diff --git a/mm/Kconfig b/mm/Kconfig
index 2310984..43ea8c3 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -251,8 +251,9 @@ config MEMORY_FAILURE
special hardware support and typically ECC memory.
config HWPOISON_INJECT
- tristate "Poison pages injector"
+ tristate "HWPoison pages injector"
depends on MEMORY_FAILURE && DEBUG_KERNEL
+ select PROC_PAGE_MONITOR
config NOMMU_INITIAL_TRIM_EXCESS
int "Turn on mmap() excess space trimming before booting"
diff --git a/mm/hwpoison-inject.c b/mm/hwpoison-inject.c
index e1d8513..10ea719 100644
--- a/mm/hwpoison-inject.c
+++ b/mm/hwpoison-inject.c
@@ -3,18 +3,68 @@
#include <linux/debugfs.h>
#include <linux/kernel.h>
#include <linux/mm.h>
+#include <linux/swap.h>
+#include <linux/pagemap.h>
+#include "internal.h"
-static struct dentry *hwpoison_dir, *corrupt_pfn;
+static struct dentry *hwpoison_dir;
static int hwpoison_inject(void *data, u64 val)
{
+ unsigned long pfn = val;
+ struct page *p;
+ int err;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ if (!hwpoison_filter_enable)
+ goto inject;
+ if (!pfn_valid(pfn))
+ return -ENXIO;
+
+ p = pfn_to_page(pfn);
+ /*
+ * This implies unable to support free buddy pages.
+ */
+ if (!get_page_unless_zero(p))
+ return 0;
+
+ if (!PageLRU(p))
+ shake_page(p, 0);
+ /*
+ * This implies unable to support non-LRU pages.
+ */
+ if (!PageLRU(p))
+ return 0;
+
+ /*
+ * do a racy check with elevated page count, to make sure PG_hwpoison
+ * will only be set for the targeted owner (or on a free page).
+ * We temporarily take page lock for try_get_mem_cgroup_from_page().
+ * __memory_failure() will redo the check reliably inside page lock.
+ */
+ lock_page(p);
+ err = hwpoison_filter(p);
+ unlock_page(p);
+ if (err)
+ return 0;
+
+inject:
+ printk(KERN_INFO "Injecting memory failure at pfn %lx\n", pfn);
+ return __memory_failure(pfn, 18, MF_COUNT_INCREASED);
+}
+
+static int hwpoison_unpoison(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);
+
+ return unpoison_memory(val);
}
DEFINE_SIMPLE_ATTRIBUTE(hwpoison_fops, NULL, hwpoison_inject, "%lli\n");
+DEFINE_SIMPLE_ATTRIBUTE(unpoison_fops, NULL, hwpoison_unpoison, "%lli\n");
static void pfn_inject_exit(void)
{
@@ -24,16 +74,63 @@ static void pfn_inject_exit(void)
static int pfn_inject_init(void)
{
+ struct dentry *dentry;
+
hwpoison_dir = debugfs_create_dir("hwpoison", NULL);
if (hwpoison_dir == NULL)
return -ENOMEM;
- corrupt_pfn = debugfs_create_file("corrupt-pfn", 0600, hwpoison_dir,
+
+ /*
+ * Note that the below poison/unpoison interfaces do not involve
+ * hardware status change, hence do not require hardware support.
+ * They are mainly for testing hwpoison in software level.
+ */
+ dentry = debugfs_create_file("corrupt-pfn", 0600, hwpoison_dir,
NULL, &hwpoison_fops);
- if (corrupt_pfn == NULL) {
- pfn_inject_exit();
- return -ENOMEM;
- }
+ if (!dentry)
+ goto fail;
+
+ dentry = debugfs_create_file("unpoison-pfn", 0600, hwpoison_dir,
+ NULL, &unpoison_fops);
+ if (!dentry)
+ goto fail;
+
+ dentry = debugfs_create_u32("corrupt-filter-enable", 0600,
+ hwpoison_dir, &hwpoison_filter_enable);
+ if (!dentry)
+ goto fail;
+
+ dentry = debugfs_create_u32("corrupt-filter-dev-major", 0600,
+ hwpoison_dir, &hwpoison_filter_dev_major);
+ if (!dentry)
+ goto fail;
+
+ dentry = debugfs_create_u32("corrupt-filter-dev-minor", 0600,
+ hwpoison_dir, &hwpoison_filter_dev_minor);
+ if (!dentry)
+ goto fail;
+
+ dentry = debugfs_create_u64("corrupt-filter-flags-mask", 0600,
+ hwpoison_dir, &hwpoison_filter_flags_mask);
+ if (!dentry)
+ goto fail;
+
+ dentry = debugfs_create_u64("corrupt-filter-flags-value", 0600,
+ hwpoison_dir, &hwpoison_filter_flags_value);
+ if (!dentry)
+ goto fail;
+
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
+ dentry = debugfs_create_u64("corrupt-filter-memcg", 0600,
+ hwpoison_dir, &hwpoison_filter_memcg);
+ if (!dentry)
+ goto fail;
+#endif
+
return 0;
+fail:
+ pfn_inject_exit();
+ return -ENOMEM;
}
module_init(pfn_inject_init);
diff --git a/mm/internal.h b/mm/internal.h
index 4fe67a1..6a697bb 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -50,6 +50,9 @@ extern void putback_lru_page(struct page *page);
*/
extern void __free_pages_bootmem(struct page *page, unsigned int order);
extern void prep_compound_page(struct page *page, unsigned long order);
+#ifdef CONFIG_MEMORY_FAILURE
+extern bool is_free_buddy_page(struct page *page);
+#endif
/*
@@ -247,3 +250,12 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
#define ZONE_RECLAIM_SOME 0
#define ZONE_RECLAIM_SUCCESS 1
#endif
+
+extern int hwpoison_filter(struct page *p);
+
+extern u32 hwpoison_filter_dev_major;
+extern u32 hwpoison_filter_dev_minor;
+extern u64 hwpoison_filter_flags_mask;
+extern u64 hwpoison_filter_flags_value;
+extern u64 hwpoison_filter_memcg;
+extern u32 hwpoison_filter_enable;
diff --git a/mm/madvise.c b/mm/madvise.c
index 35b1479b..319528b 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -9,6 +9,7 @@
#include <linux/pagemap.h>
#include <linux/syscalls.h>
#include <linux/mempolicy.h>
+#include <linux/page-isolation.h>
#include <linux/hugetlb.h>
#include <linux/sched.h>
#include <linux/ksm.h>
@@ -222,7 +223,7 @@ static long madvise_remove(struct vm_area_struct *vma,
/*
* Error injection support for memory error handling.
*/
-static int madvise_hwpoison(unsigned long start, unsigned long end)
+static int madvise_hwpoison(int bhv, unsigned long start, unsigned long end)
{
int ret = 0;
@@ -230,15 +231,21 @@ static int madvise_hwpoison(unsigned long start, unsigned long end)
return -EPERM;
for (; start < end; start += PAGE_SIZE) {
struct page *p;
- int ret = get_user_pages(current, current->mm, start, 1,
- 0, 0, &p, NULL);
+ int ret = get_user_pages_fast(start, 1, 0, &p);
if (ret != 1)
return ret;
+ if (bhv == MADV_SOFT_OFFLINE) {
+ printk(KERN_INFO "Soft offlining page %lx at %lx\n",
+ page_to_pfn(p), start);
+ ret = soft_offline_page(p, MF_COUNT_INCREASED);
+ if (ret)
+ break;
+ continue;
+ }
printk(KERN_INFO "Injecting memory failure for page %lx at %lx\n",
page_to_pfn(p), start);
/* Ignore return value for now */
- __memory_failure(page_to_pfn(p), 0, 1);
- put_page(p);
+ __memory_failure(page_to_pfn(p), 0, MF_COUNT_INCREASED);
}
return ret;
}
@@ -335,8 +342,8 @@ SYSCALL_DEFINE3(madvise, unsigned long, start, size_t, len_in, int, behavior)
size_t len;
#ifdef CONFIG_MEMORY_FAILURE
- if (behavior == MADV_HWPOISON)
- return madvise_hwpoison(start, start+len_in);
+ if (behavior == MADV_HWPOISON || behavior == MADV_SOFT_OFFLINE)
+ return madvise_hwpoison(behavior, start, start+len_in);
#endif
if (!madvise_behavior_valid(behavior))
return error;
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 878808c..488b644 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -283,6 +283,11 @@ mem_cgroup_zoneinfo(struct mem_cgroup *mem, int nid, int zid)
return &mem->info.nodeinfo[nid]->zoneinfo[zid];
}
+struct cgroup_subsys_state *mem_cgroup_css(struct mem_cgroup *mem)
+{
+ return &mem->css;
+}
+
static struct mem_cgroup_per_zone *
page_cgroup_zoneinfo(struct page_cgroup *pc)
{
@@ -1536,25 +1541,22 @@ static struct mem_cgroup *mem_cgroup_lookup(unsigned short id)
return container_of(css, struct mem_cgroup, css);
}
-static struct mem_cgroup *try_get_mem_cgroup_from_swapcache(struct page *page)
+struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page)
{
- struct mem_cgroup *mem;
+ struct mem_cgroup *mem = NULL;
struct page_cgroup *pc;
unsigned short id;
swp_entry_t ent;
VM_BUG_ON(!PageLocked(page));
- if (!PageSwapCache(page))
- return NULL;
-
pc = lookup_page_cgroup(page);
lock_page_cgroup(pc);
if (PageCgroupUsed(pc)) {
mem = pc->mem_cgroup;
if (mem && !css_tryget(&mem->css))
mem = NULL;
- } else {
+ } else if (PageSwapCache(page)) {
ent.val = page_private(page);
id = lookup_swap_cgroup(ent);
rcu_read_lock();
@@ -1874,7 +1876,7 @@ int mem_cgroup_try_charge_swapin(struct mm_struct *mm,
*/
if (!PageSwapCache(page))
goto charge_cur_mm;
- mem = try_get_mem_cgroup_from_swapcache(page);
+ mem = try_get_mem_cgroup_from_page(page);
if (!mem)
goto charge_cur_mm;
*ptr = mem;
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 50d4f8d..6a0466e 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -34,12 +34,16 @@
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/page-flags.h>
+#include <linux/kernel-page-flags.h>
#include <linux/sched.h>
#include <linux/ksm.h>
#include <linux/rmap.h>
#include <linux/pagemap.h>
#include <linux/swap.h>
#include <linux/backing-dev.h>
+#include <linux/migrate.h>
+#include <linux/page-isolation.h>
+#include <linux/suspend.h>
#include "internal.h"
int sysctl_memory_failure_early_kill __read_mostly = 0;
@@ -48,6 +52,120 @@ int sysctl_memory_failure_recovery __read_mostly = 1;
atomic_long_t mce_bad_pages __read_mostly = ATOMIC_LONG_INIT(0);
+u32 hwpoison_filter_enable = 0;
+u32 hwpoison_filter_dev_major = ~0U;
+u32 hwpoison_filter_dev_minor = ~0U;
+u64 hwpoison_filter_flags_mask;
+u64 hwpoison_filter_flags_value;
+EXPORT_SYMBOL_GPL(hwpoison_filter_enable);
+EXPORT_SYMBOL_GPL(hwpoison_filter_dev_major);
+EXPORT_SYMBOL_GPL(hwpoison_filter_dev_minor);
+EXPORT_SYMBOL_GPL(hwpoison_filter_flags_mask);
+EXPORT_SYMBOL_GPL(hwpoison_filter_flags_value);
+
+static int hwpoison_filter_dev(struct page *p)
+{
+ struct address_space *mapping;
+ dev_t dev;
+
+ if (hwpoison_filter_dev_major == ~0U &&
+ hwpoison_filter_dev_minor == ~0U)
+ return 0;
+
+ /*
+ * page_mapping() does not accept slab page
+ */
+ if (PageSlab(p))
+ return -EINVAL;
+
+ mapping = page_mapping(p);
+ if (mapping == NULL || mapping->host == NULL)
+ return -EINVAL;
+
+ dev = mapping->host->i_sb->s_dev;
+ if (hwpoison_filter_dev_major != ~0U &&
+ hwpoison_filter_dev_major != MAJOR(dev))
+ return -EINVAL;
+ if (hwpoison_filter_dev_minor != ~0U &&
+ hwpoison_filter_dev_minor != MINOR(dev))
+ return -EINVAL;
+
+ return 0;
+}
+
+static int hwpoison_filter_flags(struct page *p)
+{
+ if (!hwpoison_filter_flags_mask)
+ return 0;
+
+ if ((stable_page_flags(p) & hwpoison_filter_flags_mask) ==
+ hwpoison_filter_flags_value)
+ return 0;
+ else
+ return -EINVAL;
+}
+
+/*
+ * This allows stress tests to limit test scope to a collection of tasks
+ * by putting them under some memcg. This prevents killing unrelated/important
+ * processes such as /sbin/init. Note that the target task may share clean
+ * pages with init (eg. libc text), which is harmless. If the target task
+ * share _dirty_ pages with another task B, the test scheme must make sure B
+ * is also included in the memcg. At last, due to race conditions this filter
+ * can only guarantee that the page either belongs to the memcg tasks, or is
+ * a freed page.
+ */
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
+u64 hwpoison_filter_memcg;
+EXPORT_SYMBOL_GPL(hwpoison_filter_memcg);
+static int hwpoison_filter_task(struct page *p)
+{
+ struct mem_cgroup *mem;
+ struct cgroup_subsys_state *css;
+ unsigned long ino;
+
+ if (!hwpoison_filter_memcg)
+ return 0;
+
+ mem = try_get_mem_cgroup_from_page(p);
+ if (!mem)
+ return -EINVAL;
+
+ css = mem_cgroup_css(mem);
+ /* root_mem_cgroup has NULL dentries */
+ if (!css->cgroup->dentry)
+ return -EINVAL;
+
+ ino = css->cgroup->dentry->d_inode->i_ino;
+ css_put(css);
+
+ if (ino != hwpoison_filter_memcg)
+ return -EINVAL;
+
+ return 0;
+}
+#else
+static int hwpoison_filter_task(struct page *p) { return 0; }
+#endif
+
+int hwpoison_filter(struct page *p)
+{
+ if (!hwpoison_filter_enable)
+ return 0;
+
+ if (hwpoison_filter_dev(p))
+ return -EINVAL;
+
+ if (hwpoison_filter_flags(p))
+ return -EINVAL;
+
+ if (hwpoison_filter_task(p))
+ return -EINVAL;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(hwpoison_filter);
+
/*
* Send all the processes who have the page mapped an ``action optional''
* signal.
@@ -83,6 +201,36 @@ static int kill_proc_ao(struct task_struct *t, unsigned long addr, int trapno,
}
/*
+ * When a unknown page type is encountered drain as many buffers as possible
+ * in the hope to turn the page into a LRU or free page, which we can handle.
+ */
+void shake_page(struct page *p, int access)
+{
+ if (!PageSlab(p)) {
+ lru_add_drain_all();
+ if (PageLRU(p))
+ return;
+ drain_all_pages();
+ if (PageLRU(p) || is_free_buddy_page(p))
+ return;
+ }
+
+ /*
+ * Only all shrink_slab here (which would also
+ * shrink other caches) if access is not potentially fatal.
+ */
+ if (access) {
+ int nr;
+ do {
+ nr = shrink_slab(1000, GFP_KERNEL, 1000);
+ if (page_count(p) == 0)
+ break;
+ } while (nr > 10);
+ }
+}
+EXPORT_SYMBOL_GPL(shake_page);
+
+/*
* Kill all processes that have a poisoned page mapped and then isolate
* the page.
*
@@ -177,7 +325,6 @@ static void kill_procs_ao(struct list_head *to_kill, int doit, int trapno,
* In case something went wrong with munmapping
* make sure the process doesn't catch the
* signal and then access the memory. Just kill it.
- * the signal handlers
*/
if (fail || tk->addr_valid == 0) {
printk(KERN_ERR
@@ -314,33 +461,49 @@ static void collect_procs(struct page *page, struct list_head *tokill)
*/
enum outcome {
- FAILED, /* Error handling failed */
+ IGNORED, /* Error: cannot be handled */
+ FAILED, /* Error: handling failed */
DELAYED, /* Will be handled later */
- IGNORED, /* Error safely ignored */
RECOVERED, /* Successfully recovered */
};
static const char *action_name[] = {
+ [IGNORED] = "Ignored",
[FAILED] = "Failed",
[DELAYED] = "Delayed",
- [IGNORED] = "Ignored",
[RECOVERED] = "Recovered",
};
/*
- * Error hit kernel page.
- * Do nothing, try to be lucky and not touch this instead. For a few cases we
- * could be more sophisticated.
+ * XXX: It is possible that a page is isolated from LRU cache,
+ * and then kept in swap cache or failed to remove from page cache.
+ * The page count will stop it from being freed by unpoison.
+ * Stress tests should be aware of this memory leak problem.
*/
-static int me_kernel(struct page *p, unsigned long pfn)
+static int delete_from_lru_cache(struct page *p)
{
- return DELAYED;
+ if (!isolate_lru_page(p)) {
+ /*
+ * Clear sensible page flags, so that the buddy system won't
+ * complain when the page is unpoison-and-freed.
+ */
+ ClearPageActive(p);
+ ClearPageUnevictable(p);
+ /*
+ * drop the page count elevated by isolate_lru_page()
+ */
+ page_cache_release(p);
+ return 0;
+ }
+ return -EIO;
}
/*
- * Already poisoned page.
+ * Error hit kernel page.
+ * Do nothing, try to be lucky and not touch this instead. For a few cases we
+ * could be more sophisticated.
*/
-static int me_ignore(struct page *p, unsigned long pfn)
+static int me_kernel(struct page *p, unsigned long pfn)
{
return IGNORED;
}
@@ -355,14 +518,6 @@ static int me_unknown(struct page *p, unsigned long pfn)
}
/*
- * Free memory
- */
-static int me_free(struct page *p, unsigned long pfn)
-{
- return DELAYED;
-}
-
-/*
* Clean (or cleaned) page cache page.
*/
static int me_pagecache_clean(struct page *p, unsigned long pfn)
@@ -371,6 +526,8 @@ static int me_pagecache_clean(struct page *p, unsigned long pfn)
int ret = FAILED;
struct address_space *mapping;
+ delete_from_lru_cache(p);
+
/*
* For anonymous pages we're done the only reference left
* should be the one m_f() holds.
@@ -500,14 +657,20 @@ static int me_swapcache_dirty(struct page *p, unsigned long pfn)
/* Trigger EIO in shmem: */
ClearPageUptodate(p);
- return DELAYED;
+ if (!delete_from_lru_cache(p))
+ return DELAYED;
+ else
+ return FAILED;
}
static int me_swapcache_clean(struct page *p, unsigned long pfn)
{
delete_from_swap_cache(p);
- return RECOVERED;
+ if (!delete_from_lru_cache(p))
+ return RECOVERED;
+ else
+ return FAILED;
}
/*
@@ -550,7 +713,6 @@ static int me_huge_page(struct page *p, unsigned long pfn)
#define tail (1UL << PG_tail)
#define compound (1UL << PG_compound)
#define slab (1UL << PG_slab)
-#define buddy (1UL << PG_buddy)
#define reserved (1UL << PG_reserved)
static struct page_state {
@@ -559,8 +721,11 @@ static struct page_state {
char *msg;
int (*action)(struct page *p, unsigned long pfn);
} error_states[] = {
- { reserved, reserved, "reserved kernel", me_ignore },
- { buddy, buddy, "free kernel", me_free },
+ { reserved, reserved, "reserved kernel", me_kernel },
+ /*
+ * free pages are specially detected outside this table:
+ * PG_buddy pages only make a small fraction of all free pages.
+ */
/*
* Could in theory check if slab page is free or if we can drop
@@ -587,7 +752,6 @@ static struct page_state {
{ lru|dirty, lru|dirty, "LRU", me_pagecache_dirty },
{ lru|dirty, lru, "clean LRU", me_pagecache_clean },
- { swapbacked, swapbacked, "anonymous", me_pagecache_clean },
/*
* Catchall entry: must be at end.
@@ -595,20 +759,31 @@ static struct page_state {
{ 0, 0, "unknown page state", me_unknown },
};
+#undef dirty
+#undef sc
+#undef unevict
+#undef mlock
+#undef writeback
+#undef lru
+#undef swapbacked
+#undef head
+#undef tail
+#undef compound
+#undef slab
+#undef reserved
+
static void action_result(unsigned long pfn, char *msg, int result)
{
- struct page *page = NULL;
- if (pfn_valid(pfn))
- page = pfn_to_page(pfn);
+ struct page *page = pfn_to_page(pfn);
printk(KERN_ERR "MCE %#lx: %s%s page recovery: %s\n",
pfn,
- page && PageDirty(page) ? "dirty " : "",
+ PageDirty(page) ? "dirty " : "",
msg, action_name[result]);
}
static int page_action(struct page_state *ps, struct page *p,
- unsigned long pfn, int ref)
+ unsigned long pfn)
{
int result;
int count;
@@ -616,18 +791,22 @@ static int page_action(struct page_state *ps, struct page *p,
result = ps->action(p, pfn);
action_result(pfn, ps->msg, result);
- count = page_count(p) - 1 - ref;
- if (count != 0)
+ count = page_count(p) - 1;
+ if (ps->action == me_swapcache_dirty && result == DELAYED)
+ count--;
+ if (count != 0) {
printk(KERN_ERR
"MCE %#lx: %s page still referenced by %d users\n",
pfn, ps->msg, count);
+ result = FAILED;
+ }
/* Could do more checks here if page looks ok */
/*
* Could adjust zone counters here to correct for the missing page.
*/
- return result == RECOVERED ? 0 : -EBUSY;
+ return (result == RECOVERED || result == DELAYED) ? 0 : -EBUSY;
}
#define N_UNMAP_TRIES 5
@@ -636,7 +815,7 @@ static int page_action(struct page_state *ps, struct page *p,
* 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;
@@ -646,15 +825,18 @@ static void hwpoison_user_mappings(struct page *p, unsigned long pfn,
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
@@ -665,6 +847,8 @@ static void hwpoison_user_mappings(struct page *p, unsigned long pfn,
/*
* Propagate the dirty bit from PTEs to struct page first, because we
* need this to decide if we should kill or just drop the page.
+ * XXX: the dirty test could be racy: set_page_dirty() may not always
+ * be called inside page lock (it's recommended but not enforced).
*/
mapping = page_mapping(p);
if (!PageDirty(p) && mapping && mapping_cap_writeback_dirty(mapping)) {
@@ -716,11 +900,12 @@ static void hwpoison_user_mappings(struct page *p, unsigned long pfn,
*/
kill_procs_ao(&tokill, !!PageDirty(p), trapno,
ret != SWAP_SUCCESS, pfn);
+
+ return ret;
}
-int __memory_failure(unsigned long pfn, int trapno, int ref)
+int __memory_failure(unsigned long pfn, int trapno, int flags)
{
- unsigned long lru_flag;
struct page_state *ps;
struct page *p;
int res;
@@ -729,13 +914,15 @@ int __memory_failure(unsigned long pfn, int trapno, int ref)
panic("Memory failure from trap %d on page %lx", trapno, pfn);
if (!pfn_valid(pfn)) {
- action_result(pfn, "memory outside kernel control", IGNORED);
- return -EIO;
+ printk(KERN_ERR
+ "MCE %#lx: memory outside kernel control\n",
+ pfn);
+ return -ENXIO;
}
p = pfn_to_page(pfn);
if (TestSetPageHWPoison(p)) {
- action_result(pfn, "already hardware poisoned", IGNORED);
+ printk(KERN_ERR "MCE %#lx: already hardware poisoned\n", pfn);
return 0;
}
@@ -752,9 +939,15 @@ int __memory_failure(unsigned long pfn, int trapno, int ref)
* In fact it's dangerous to directly bump up page count from 0,
* that may make page_freeze_refs()/page_unfreeze_refs() mismatch.
*/
- if (!get_page_unless_zero(compound_head(p))) {
- action_result(pfn, "free or high order kernel", IGNORED);
- return PageBuddy(compound_head(p)) ? 0 : -EBUSY;
+ if (!(flags & MF_COUNT_INCREASED) &&
+ !get_page_unless_zero(compound_head(p))) {
+ if (is_free_buddy_page(p)) {
+ action_result(pfn, "free buddy", DELAYED);
+ return 0;
+ } else {
+ action_result(pfn, "high order kernel", IGNORED);
+ return -EBUSY;
+ }
}
/*
@@ -766,14 +959,19 @@ int __memory_failure(unsigned long pfn, int trapno, int ref)
* walked by the page reclaim code, however that's not a big loss.
*/
if (!PageLRU(p))
- lru_add_drain_all();
- lru_flag = p->flags & lru;
- if (isolate_lru_page(p)) {
+ shake_page(p, 0);
+ if (!PageLRU(p)) {
+ /*
+ * shake_page could have turned it free.
+ */
+ if (is_free_buddy_page(p)) {
+ action_result(pfn, "free buddy, 2nd try", DELAYED);
+ return 0;
+ }
action_result(pfn, "non LRU", IGNORED);
put_page(p);
return -EBUSY;
}
- page_cache_release(p);
/*
* Lock the page and wait for writeback to finish.
@@ -781,26 +979,48 @@ int __memory_failure(unsigned long pfn, int trapno, int ref)
* and in many cases impossible, so we just avoid it here.
*/
lock_page_nosync(p);
+
+ /*
+ * unpoison always clear PG_hwpoison inside page lock
+ */
+ if (!PageHWPoison(p)) {
+ printk(KERN_ERR "MCE %#lx: just unpoisoned\n", pfn);
+ res = 0;
+ goto out;
+ }
+ if (hwpoison_filter(p)) {
+ if (TestClearPageHWPoison(p))
+ atomic_long_dec(&mce_bad_pages);
+ unlock_page(p);
+ put_page(p);
+ return 0;
+ }
+
wait_on_page_writeback(p);
/*
* 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?
*/
- if ((lru_flag & lru) && !PageSwapCache(p) && p->mapping == NULL) {
+ if (PageLRU(p) && !PageSwapCache(p) && p->mapping == NULL) {
action_result(pfn, "already truncated LRU", IGNORED);
- res = 0;
+ res = -EBUSY;
goto out;
}
res = -EBUSY;
for (ps = error_states;; ps++) {
- if (((p->flags | lru_flag)& ps->mask) == ps->res) {
- res = page_action(ps, p, pfn, ref);
+ if ((p->flags & ps->mask) == ps->res) {
+ res = page_action(ps, p, pfn);
break;
}
}
@@ -831,3 +1051,235 @@ void memory_failure(unsigned long pfn, int trapno)
{
__memory_failure(pfn, trapno, 0);
}
+
+/**
+ * unpoison_memory - Unpoison a previously poisoned page
+ * @pfn: Page number of the to be unpoisoned page
+ *
+ * Software-unpoison a page that has been poisoned by
+ * memory_failure() earlier.
+ *
+ * This is only done on the software-level, so it only works
+ * for linux injected failures, not real hardware failures
+ *
+ * Returns 0 for success, otherwise -errno.
+ */
+int unpoison_memory(unsigned long pfn)
+{
+ struct page *page;
+ struct page *p;
+ int freeit = 0;
+
+ if (!pfn_valid(pfn))
+ return -ENXIO;
+
+ p = pfn_to_page(pfn);
+ page = compound_head(p);
+
+ if (!PageHWPoison(p)) {
+ pr_debug("MCE: Page was already unpoisoned %#lx\n", pfn);
+ return 0;
+ }
+
+ if (!get_page_unless_zero(page)) {
+ if (TestClearPageHWPoison(p))
+ atomic_long_dec(&mce_bad_pages);
+ pr_debug("MCE: Software-unpoisoned free page %#lx\n", pfn);
+ return 0;
+ }
+
+ lock_page_nosync(page);
+ /*
+ * This test is racy because PG_hwpoison is set outside of page lock.
+ * That's acceptable because that won't trigger kernel panic. Instead,
+ * the PG_hwpoison page will be caught and isolated on the entrance to
+ * the free buddy page pool.
+ */
+ if (TestClearPageHWPoison(p)) {
+ pr_debug("MCE: Software-unpoisoned page %#lx\n", pfn);
+ atomic_long_dec(&mce_bad_pages);
+ freeit = 1;
+ }
+ unlock_page(page);
+
+ put_page(page);
+ if (freeit)
+ put_page(page);
+
+ return 0;
+}
+EXPORT_SYMBOL(unpoison_memory);
+
+static struct page *new_page(struct page *p, unsigned long private, int **x)
+{
+ int nid = page_to_nid(p);
+ return alloc_pages_exact_node(nid, GFP_HIGHUSER_MOVABLE, 0);
+}
+
+/*
+ * Safely get reference count of an arbitrary page.
+ * Returns 0 for a free page, -EIO for a zero refcount page
+ * that is not free, and 1 for any other page type.
+ * For 1 the page is returned with increased page count, otherwise not.
+ */
+static int get_any_page(struct page *p, unsigned long pfn, int flags)
+{
+ int ret;
+
+ if (flags & MF_COUNT_INCREASED)
+ return 1;
+
+ /*
+ * The lock_system_sleep prevents a race with memory hotplug,
+ * because the isolation assumes there's only a single user.
+ * This is a big hammer, a better would be nicer.
+ */
+ lock_system_sleep();
+
+ /*
+ * Isolate the page, so that it doesn't get reallocated if it
+ * was free.
+ */
+ set_migratetype_isolate(p);
+ if (!get_page_unless_zero(compound_head(p))) {
+ if (is_free_buddy_page(p)) {
+ pr_debug("get_any_page: %#lx free buddy page\n", pfn);
+ /* Set hwpoison bit while page is still isolated */
+ SetPageHWPoison(p);
+ ret = 0;
+ } else {
+ pr_debug("get_any_page: %#lx: unknown zero refcount page type %lx\n",
+ pfn, p->flags);
+ ret = -EIO;
+ }
+ } else {
+ /* Not a free page */
+ ret = 1;
+ }
+ unset_migratetype_isolate(p);
+ unlock_system_sleep();
+ return ret;
+}
+
+/**
+ * soft_offline_page - Soft offline a page.
+ * @page: page to offline
+ * @flags: flags. Same as memory_failure().
+ *
+ * Returns 0 on success, otherwise negated errno.
+ *
+ * Soft offline a page, by migration or invalidation,
+ * without killing anything. This is for the case when
+ * a page is not corrupted yet (so it's still valid to access),
+ * but has had a number of corrected errors and is better taken
+ * out.
+ *
+ * The actual policy on when to do that is maintained by
+ * user space.
+ *
+ * This should never impact any application or cause data loss,
+ * however it might take some time.
+ *
+ * This is not a 100% solution for all memory, but tries to be
+ * ``good enough'' for the majority of memory.
+ */
+int soft_offline_page(struct page *page, int flags)
+{
+ int ret;
+ unsigned long pfn = page_to_pfn(page);
+
+ ret = get_any_page(page, pfn, flags);
+ if (ret < 0)
+ return ret;
+ if (ret == 0)
+ goto done;
+
+ /*
+ * Page cache page we can handle?
+ */
+ if (!PageLRU(page)) {
+ /*
+ * Try to free it.
+ */
+ put_page(page);
+ shake_page(page, 1);
+
+ /*
+ * Did it turn free?
+ */
+ ret = get_any_page(page, pfn, 0);
+ if (ret < 0)
+ return ret;
+ if (ret == 0)
+ goto done;
+ }
+ if (!PageLRU(page)) {
+ pr_debug("soft_offline: %#lx: unknown non LRU page type %lx\n",
+ pfn, page->flags);
+ return -EIO;
+ }
+
+ lock_page(page);
+ wait_on_page_writeback(page);
+
+ /*
+ * Synchronized using the page lock with memory_failure()
+ */
+ if (PageHWPoison(page)) {
+ unlock_page(page);
+ put_page(page);
+ pr_debug("soft offline: %#lx page already poisoned\n", pfn);
+ return -EBUSY;
+ }
+
+ /*
+ * Try to invalidate first. This should work for
+ * non dirty unmapped page cache pages.
+ */
+ ret = invalidate_inode_page(page);
+ unlock_page(page);
+
+ /*
+ * Drop count because page migration doesn't like raised
+ * counts. The page could get re-allocated, but if it becomes
+ * LRU the isolation will just fail.
+ * RED-PEN would be better to keep it isolated here, but we
+ * would need to fix isolation locking first.
+ */
+ put_page(page);
+ if (ret == 1) {
+ ret = 0;
+ pr_debug("soft_offline: %#lx: invalidated\n", pfn);
+ goto done;
+ }
+
+ /*
+ * Simple invalidation didn't work.
+ * Try to migrate to a new page instead. migrate.c
+ * handles a large number of cases for us.
+ */
+ ret = isolate_lru_page(page);
+ if (!ret) {
+ LIST_HEAD(pagelist);
+
+ list_add(&page->lru, &pagelist);
+ ret = migrate_pages(&pagelist, new_page, MPOL_MF_MOVE_ALL, 0);
+ if (ret) {
+ pr_debug("soft offline: %#lx: migration failed %d, type %lx\n",
+ pfn, ret, page->flags);
+ if (ret > 0)
+ ret = -EIO;
+ }
+ } else {
+ pr_debug("soft offline: %#lx: isolation failed: %d, page count %d, type %lx\n",
+ pfn, ret, page_count(page), page->flags);
+ }
+ if (ret)
+ return ret;
+
+done:
+ atomic_long_add(1, &mce_bad_pages);
+ SetPageHWPoison(page);
+ /* keep elevated page count for bad page */
+ return ret;
+}
diff --git a/mm/memory.c b/mm/memory.c
index aed45ea..09e4b1b 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2555,6 +2555,10 @@ static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma,
ret = VM_FAULT_MAJOR;
count_vm_event(PGMAJFAULT);
} else if (PageHWPoison(page)) {
+ /*
+ * hwpoisoned dirty swapcache pages are kept for killing
+ * owner processes (which may be unknown at hwpoison time)
+ */
ret = VM_FAULT_HWPOISON;
delayacct_clear_flag(DELAYACCT_PF_SWAPIN);
goto out_release;
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 850c4a7..74af449 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -5091,3 +5091,24 @@ __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
spin_unlock_irqrestore(&zone->lock, flags);
}
#endif
+
+#ifdef CONFIG_MEMORY_FAILURE
+bool is_free_buddy_page(struct page *page)
+{
+ struct zone *zone = page_zone(page);
+ unsigned long pfn = page_to_pfn(page);
+ unsigned long flags;
+ int order;
+
+ spin_lock_irqsave(&zone->lock, flags);
+ for (order = 0; order < MAX_ORDER; order++) {
+ struct page *page_head = page - (pfn & ((1 << order) - 1));
+
+ if (PageBuddy(page_head) && page_order(page_head) >= order)
+ break;
+ }
+ spin_unlock_irqrestore(&zone->lock, flags);
+
+ return order < MAX_ORDER;
+}
+#endif
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