blob: de88f33519c0d6398de8fcc06bfa82f2a477dd95 [file] [log] [blame]
Andi Kleen6a460792009-09-16 11:50:15 +02001/*
2 * Copyright (C) 2008, 2009 Intel Corporation
3 * Authors: Andi Kleen, Fengguang Wu
4 *
5 * This software may be redistributed and/or modified under the terms of
6 * the GNU General Public License ("GPL") version 2 only as published by the
7 * Free Software Foundation.
8 *
9 * High level machine check handler. Handles pages reported by the
Andi Kleen1c80b992010-09-27 23:09:51 +020010 * hardware as being corrupted usually due to a multi-bit ECC memory or cache
Andi Kleen6a460792009-09-16 11:50:15 +020011 * failure.
Andi Kleen1c80b992010-09-27 23:09:51 +020012 *
13 * In addition there is a "soft offline" entry point that allows stop using
14 * not-yet-corrupted-by-suspicious pages without killing anything.
Andi Kleen6a460792009-09-16 11:50:15 +020015 *
16 * Handles page cache pages in various states. The tricky part
Andi Kleen1c80b992010-09-27 23:09:51 +020017 * here is that we can access any page asynchronously in respect to
18 * other VM users, because memory failures could happen anytime and
19 * anywhere. This could violate some of their assumptions. This is why
20 * this code has to be extremely careful. Generally it tries to use
21 * normal locking rules, as in get the standard locks, even if that means
22 * the error handling takes potentially a long time.
Andi Kleene0de78d2015-06-24 16:56:02 -070023 *
24 * It can be very tempting to add handling for obscure cases here.
25 * In general any code for handling new cases should only be added iff:
26 * - You know how to test it.
27 * - You have a test that can be added to mce-test
28 * https://git.kernel.org/cgit/utils/cpu/mce/mce-test.git/
29 * - The case actually shows up as a frequent (top 10) page state in
30 * tools/vm/page-types when running a real workload.
Andi Kleen1c80b992010-09-27 23:09:51 +020031 *
32 * There are several operations here with exponential complexity because
33 * of unsuitable VM data structures. For example the operation to map back
34 * from RMAP chains to processes has to walk the complete process list and
35 * has non linear complexity with the number. But since memory corruptions
36 * are rare we hope to get away with this. This avoids impacting the core
37 * VM.
Andi Kleen6a460792009-09-16 11:50:15 +020038 */
Andi Kleen6a460792009-09-16 11:50:15 +020039#include <linux/kernel.h>
40#include <linux/mm.h>
41#include <linux/page-flags.h>
Wu Fengguang478c5ff2009-12-16 12:19:59 +010042#include <linux/kernel-page-flags.h>
Andi Kleen6a460792009-09-16 11:50:15 +020043#include <linux/sched.h>
Hugh Dickins01e00f82009-10-13 15:02:11 +010044#include <linux/ksm.h>
Andi Kleen6a460792009-09-16 11:50:15 +020045#include <linux/rmap.h>
Paul Gortmakerb9e15ba2011-05-26 16:00:52 -040046#include <linux/export.h>
Andi Kleen6a460792009-09-16 11:50:15 +020047#include <linux/pagemap.h>
48#include <linux/swap.h>
49#include <linux/backing-dev.h>
Andi Kleenfacb6012009-12-16 12:20:00 +010050#include <linux/migrate.h>
51#include <linux/page-isolation.h>
52#include <linux/suspend.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090053#include <linux/slab.h>
Huang Yingbf998152010-05-31 14:28:19 +080054#include <linux/swapops.h>
Naoya Horiguchi7af446a2010-05-28 09:29:17 +090055#include <linux/hugetlb.h>
KOSAKI Motohiro20d6c962010-12-02 14:31:19 -080056#include <linux/memory_hotplug.h>
Minchan Kim5db8a732011-06-15 15:08:48 -070057#include <linux/mm_inline.h>
Huang Yingea8f5fb2011-07-13 13:14:27 +080058#include <linux/kfifo.h>
Naoya Horiguchia5f65102015-11-05 18:47:26 -080059#include <linux/ratelimit.h>
Andi Kleen6a460792009-09-16 11:50:15 +020060#include "internal.h"
Xie XiuQi97f0b132015-06-24 16:57:36 -070061#include "ras/ras_event.h"
Andi Kleen6a460792009-09-16 11:50:15 +020062
63int sysctl_memory_failure_early_kill __read_mostly = 0;
64
65int sysctl_memory_failure_recovery __read_mostly = 1;
66
Xishi Qiu293c07e2013-02-22 16:34:02 -080067atomic_long_t num_poisoned_pages __read_mostly = ATOMIC_LONG_INIT(0);
Andi Kleen6a460792009-09-16 11:50:15 +020068
Andi Kleen27df5062009-12-21 19:56:42 +010069#if defined(CONFIG_HWPOISON_INJECT) || defined(CONFIG_HWPOISON_INJECT_MODULE)
70
Haicheng Li1bfe5fe2009-12-16 12:19:59 +010071u32 hwpoison_filter_enable = 0;
Wu Fengguang7c116f22009-12-16 12:19:59 +010072u32 hwpoison_filter_dev_major = ~0U;
73u32 hwpoison_filter_dev_minor = ~0U;
Wu Fengguang478c5ff2009-12-16 12:19:59 +010074u64 hwpoison_filter_flags_mask;
75u64 hwpoison_filter_flags_value;
Haicheng Li1bfe5fe2009-12-16 12:19:59 +010076EXPORT_SYMBOL_GPL(hwpoison_filter_enable);
Wu Fengguang7c116f22009-12-16 12:19:59 +010077EXPORT_SYMBOL_GPL(hwpoison_filter_dev_major);
78EXPORT_SYMBOL_GPL(hwpoison_filter_dev_minor);
Wu Fengguang478c5ff2009-12-16 12:19:59 +010079EXPORT_SYMBOL_GPL(hwpoison_filter_flags_mask);
80EXPORT_SYMBOL_GPL(hwpoison_filter_flags_value);
Wu Fengguang7c116f22009-12-16 12:19:59 +010081
82static int hwpoison_filter_dev(struct page *p)
83{
84 struct address_space *mapping;
85 dev_t dev;
86
87 if (hwpoison_filter_dev_major == ~0U &&
88 hwpoison_filter_dev_minor == ~0U)
89 return 0;
90
91 /*
Andi Kleen1c80b992010-09-27 23:09:51 +020092 * page_mapping() does not accept slab pages.
Wu Fengguang7c116f22009-12-16 12:19:59 +010093 */
94 if (PageSlab(p))
95 return -EINVAL;
96
97 mapping = page_mapping(p);
98 if (mapping == NULL || mapping->host == NULL)
99 return -EINVAL;
100
101 dev = mapping->host->i_sb->s_dev;
102 if (hwpoison_filter_dev_major != ~0U &&
103 hwpoison_filter_dev_major != MAJOR(dev))
104 return -EINVAL;
105 if (hwpoison_filter_dev_minor != ~0U &&
106 hwpoison_filter_dev_minor != MINOR(dev))
107 return -EINVAL;
108
109 return 0;
110}
111
Wu Fengguang478c5ff2009-12-16 12:19:59 +0100112static int hwpoison_filter_flags(struct page *p)
113{
114 if (!hwpoison_filter_flags_mask)
115 return 0;
116
117 if ((stable_page_flags(p) & hwpoison_filter_flags_mask) ==
118 hwpoison_filter_flags_value)
119 return 0;
120 else
121 return -EINVAL;
122}
123
Andi Kleen4fd466e2009-12-16 12:19:59 +0100124/*
125 * This allows stress tests to limit test scope to a collection of tasks
126 * by putting them under some memcg. This prevents killing unrelated/important
127 * processes such as /sbin/init. Note that the target task may share clean
128 * pages with init (eg. libc text), which is harmless. If the target task
129 * share _dirty_ pages with another task B, the test scheme must make sure B
130 * is also included in the memcg. At last, due to race conditions this filter
131 * can only guarantee that the page either belongs to the memcg tasks, or is
132 * a freed page.
133 */
Vladimir Davydov94a59fb2015-09-09 15:35:31 -0700134#ifdef CONFIG_MEMCG
Andi Kleen4fd466e2009-12-16 12:19:59 +0100135u64 hwpoison_filter_memcg;
136EXPORT_SYMBOL_GPL(hwpoison_filter_memcg);
137static int hwpoison_filter_task(struct page *p)
138{
Andi Kleen4fd466e2009-12-16 12:19:59 +0100139 if (!hwpoison_filter_memcg)
140 return 0;
141
Vladimir Davydov94a59fb2015-09-09 15:35:31 -0700142 if (page_cgroup_ino(p) != hwpoison_filter_memcg)
Andi Kleen4fd466e2009-12-16 12:19:59 +0100143 return -EINVAL;
144
145 return 0;
146}
147#else
148static int hwpoison_filter_task(struct page *p) { return 0; }
149#endif
150
Wu Fengguang7c116f22009-12-16 12:19:59 +0100151int hwpoison_filter(struct page *p)
152{
Haicheng Li1bfe5fe2009-12-16 12:19:59 +0100153 if (!hwpoison_filter_enable)
154 return 0;
155
Wu Fengguang7c116f22009-12-16 12:19:59 +0100156 if (hwpoison_filter_dev(p))
157 return -EINVAL;
158
Wu Fengguang478c5ff2009-12-16 12:19:59 +0100159 if (hwpoison_filter_flags(p))
160 return -EINVAL;
161
Andi Kleen4fd466e2009-12-16 12:19:59 +0100162 if (hwpoison_filter_task(p))
163 return -EINVAL;
164
Wu Fengguang7c116f22009-12-16 12:19:59 +0100165 return 0;
166}
Andi Kleen27df5062009-12-21 19:56:42 +0100167#else
168int hwpoison_filter(struct page *p)
169{
170 return 0;
171}
172#endif
173
Wu Fengguang7c116f22009-12-16 12:19:59 +0100174EXPORT_SYMBOL_GPL(hwpoison_filter);
175
Andi Kleen6a460792009-09-16 11:50:15 +0200176/*
Tony Luck7329bbe2011-12-13 09:27:58 -0800177 * Send all the processes who have the page mapped a signal.
178 * ``action optional'' if they are not immediately affected by the error
179 * ``action required'' if error happened in current execution context
Andi Kleen6a460792009-09-16 11:50:15 +0200180 */
Tony Luck7329bbe2011-12-13 09:27:58 -0800181static int kill_proc(struct task_struct *t, unsigned long addr, int trapno,
182 unsigned long pfn, struct page *page, int flags)
Andi Kleen6a460792009-09-16 11:50:15 +0200183{
184 struct siginfo si;
185 int ret;
186
Chen Yucong495367c02016-05-20 16:57:32 -0700187 pr_err("Memory failure: %#lx: Killing %s:%d due to hardware memory corruption\n",
188 pfn, t->comm, t->pid);
Andi Kleen6a460792009-09-16 11:50:15 +0200189 si.si_signo = SIGBUS;
190 si.si_errno = 0;
Andi Kleen6a460792009-09-16 11:50:15 +0200191 si.si_addr = (void *)addr;
192#ifdef __ARCH_SI_TRAPNO
193 si.si_trapno = trapno;
194#endif
Wanpeng Lif9121152013-09-11 14:22:52 -0700195 si.si_addr_lsb = compound_order(compound_head(page)) + PAGE_SHIFT;
Tony Luck7329bbe2011-12-13 09:27:58 -0800196
Tony Lucka70ffca2014-06-04 16:10:59 -0700197 if ((flags & MF_ACTION_REQUIRED) && t->mm == current->mm) {
Tony Luck7329bbe2011-12-13 09:27:58 -0800198 si.si_code = BUS_MCEERR_AR;
Tony Lucka70ffca2014-06-04 16:10:59 -0700199 ret = force_sig_info(SIGBUS, &si, current);
Tony Luck7329bbe2011-12-13 09:27:58 -0800200 } else {
201 /*
202 * Don't use force here, it's convenient if the signal
203 * can be temporarily blocked.
204 * This could cause a loop when the user sets SIGBUS
205 * to SIG_IGN, but hopefully no one will do that?
206 */
207 si.si_code = BUS_MCEERR_AO;
208 ret = send_sig_info(SIGBUS, &si, t); /* synchronous? */
209 }
Andi Kleen6a460792009-09-16 11:50:15 +0200210 if (ret < 0)
Chen Yucong495367c02016-05-20 16:57:32 -0700211 pr_info("Memory failure: Error sending signal to %s:%d: %d\n",
Joe Perches11705322016-03-17 14:19:50 -0700212 t->comm, t->pid, ret);
Andi Kleen6a460792009-09-16 11:50:15 +0200213 return ret;
214}
215
216/*
Andi Kleen588f9ce2009-12-16 12:19:57 +0100217 * When a unknown page type is encountered drain as many buffers as possible
218 * in the hope to turn the page into a LRU or free page, which we can handle.
219 */
Andi Kleenfacb6012009-12-16 12:20:00 +0100220void shake_page(struct page *p, int access)
Andi Kleen588f9ce2009-12-16 12:19:57 +0100221{
222 if (!PageSlab(p)) {
223 lru_add_drain_all();
224 if (PageLRU(p))
225 return;
Vlastimil Babkac0554322014-12-10 15:43:10 -0800226 drain_all_pages(page_zone(p));
Andi Kleen588f9ce2009-12-16 12:19:57 +0100227 if (PageLRU(p) || is_free_buddy_page(p))
228 return;
229 }
Andi Kleenfacb6012009-12-16 12:20:00 +0100230
Andi Kleen588f9ce2009-12-16 12:19:57 +0100231 /*
Johannes Weiner6b4f7792014-12-12 16:56:13 -0800232 * Only call shrink_node_slabs here (which would also shrink
233 * other caches) if access is not potentially fatal.
Andi Kleen588f9ce2009-12-16 12:19:57 +0100234 */
Vladimir Davydovcb731d62015-02-12 14:58:54 -0800235 if (access)
236 drop_slab_node(page_to_nid(p));
Andi Kleen588f9ce2009-12-16 12:19:57 +0100237}
238EXPORT_SYMBOL_GPL(shake_page);
239
240/*
Andi Kleen6a460792009-09-16 11:50:15 +0200241 * Kill all processes that have a poisoned page mapped and then isolate
242 * the page.
243 *
244 * General strategy:
245 * Find all processes having the page mapped and kill them.
246 * But we keep a page reference around so that the page is not
247 * actually freed yet.
248 * Then stash the page away
249 *
250 * There's no convenient way to get back to mapped processes
251 * from the VMAs. So do a brute-force search over all
252 * running processes.
253 *
254 * Remember that machine checks are not common (or rather
255 * if they are common you have other problems), so this shouldn't
256 * be a performance issue.
257 *
258 * Also there are some races possible while we get from the
259 * error detection to actually handle it.
260 */
261
262struct to_kill {
263 struct list_head nd;
264 struct task_struct *tsk;
265 unsigned long addr;
Andi Kleen9033ae12010-09-27 23:36:05 +0200266 char addr_valid;
Andi Kleen6a460792009-09-16 11:50:15 +0200267};
268
269/*
270 * Failure handling: if we can't find or can't kill a process there's
271 * not much we can do. We just print a message and ignore otherwise.
272 */
273
274/*
275 * Schedule a process for later kill.
276 * Uses GFP_ATOMIC allocations to avoid potential recursions in the VM.
277 * TBD would GFP_NOIO be enough?
278 */
279static void add_to_kill(struct task_struct *tsk, struct page *p,
280 struct vm_area_struct *vma,
281 struct list_head *to_kill,
282 struct to_kill **tkc)
283{
284 struct to_kill *tk;
285
286 if (*tkc) {
287 tk = *tkc;
288 *tkc = NULL;
289 } else {
290 tk = kmalloc(sizeof(struct to_kill), GFP_ATOMIC);
291 if (!tk) {
Chen Yucong495367c02016-05-20 16:57:32 -0700292 pr_err("Memory failure: Out of memory while machine check handling\n");
Andi Kleen6a460792009-09-16 11:50:15 +0200293 return;
294 }
295 }
296 tk->addr = page_address_in_vma(p, vma);
297 tk->addr_valid = 1;
298
299 /*
300 * In theory we don't have to kill when the page was
301 * munmaped. But it could be also a mremap. Since that's
302 * likely very rare kill anyways just out of paranoia, but use
303 * a SIGKILL because the error is not contained anymore.
304 */
305 if (tk->addr == -EFAULT) {
Chen Yucong495367c02016-05-20 16:57:32 -0700306 pr_info("Memory failure: Unable to find user space address %lx in %s\n",
Andi Kleen6a460792009-09-16 11:50:15 +0200307 page_to_pfn(p), tsk->comm);
308 tk->addr_valid = 0;
309 }
310 get_task_struct(tsk);
311 tk->tsk = tsk;
312 list_add_tail(&tk->nd, to_kill);
313}
314
315/*
316 * Kill the processes that have been collected earlier.
317 *
318 * Only do anything when DOIT is set, otherwise just free the list
319 * (this is used for clean pages which do not need killing)
320 * Also when FAIL is set do a force kill because something went
321 * wrong earlier.
322 */
Tony Luck6751ed62012-07-11 10:20:47 -0700323static void kill_procs(struct list_head *to_kill, int forcekill, int trapno,
Tony Luck7329bbe2011-12-13 09:27:58 -0800324 int fail, struct page *page, unsigned long pfn,
325 int flags)
Andi Kleen6a460792009-09-16 11:50:15 +0200326{
327 struct to_kill *tk, *next;
328
329 list_for_each_entry_safe (tk, next, to_kill, nd) {
Tony Luck6751ed62012-07-11 10:20:47 -0700330 if (forcekill) {
Andi Kleen6a460792009-09-16 11:50:15 +0200331 /*
André Goddard Rosaaf901ca2009-11-14 13:09:05 -0200332 * In case something went wrong with munmapping
Andi Kleen6a460792009-09-16 11:50:15 +0200333 * make sure the process doesn't catch the
334 * signal and then access the memory. Just kill it.
Andi Kleen6a460792009-09-16 11:50:15 +0200335 */
336 if (fail || tk->addr_valid == 0) {
Chen Yucong495367c02016-05-20 16:57:32 -0700337 pr_err("Memory failure: %#lx: forcibly killing %s:%d because of failure to unmap corrupted page\n",
Joe Perches11705322016-03-17 14:19:50 -0700338 pfn, tk->tsk->comm, tk->tsk->pid);
Andi Kleen6a460792009-09-16 11:50:15 +0200339 force_sig(SIGKILL, tk->tsk);
340 }
341
342 /*
343 * In theory the process could have mapped
344 * something else on the address in-between. We could
345 * check for that, but we need to tell the
346 * process anyways.
347 */
Tony Luck7329bbe2011-12-13 09:27:58 -0800348 else if (kill_proc(tk->tsk, tk->addr, trapno,
349 pfn, page, flags) < 0)
Chen Yucong495367c02016-05-20 16:57:32 -0700350 pr_err("Memory failure: %#lx: Cannot send advisory machine check signal to %s:%d\n",
Joe Perches11705322016-03-17 14:19:50 -0700351 pfn, tk->tsk->comm, tk->tsk->pid);
Andi Kleen6a460792009-09-16 11:50:15 +0200352 }
353 put_task_struct(tk->tsk);
354 kfree(tk);
355 }
356}
357
Naoya Horiguchi3ba08122014-06-04 16:11:02 -0700358/*
359 * Find a dedicated thread which is supposed to handle SIGBUS(BUS_MCEERR_AO)
360 * on behalf of the thread group. Return task_struct of the (first found)
361 * dedicated thread if found, and return NULL otherwise.
362 *
363 * We already hold read_lock(&tasklist_lock) in the caller, so we don't
364 * have to call rcu_read_lock/unlock() in this function.
365 */
366static struct task_struct *find_early_kill_thread(struct task_struct *tsk)
Andi Kleen6a460792009-09-16 11:50:15 +0200367{
Naoya Horiguchi3ba08122014-06-04 16:11:02 -0700368 struct task_struct *t;
369
370 for_each_thread(tsk, t)
371 if ((t->flags & PF_MCE_PROCESS) && (t->flags & PF_MCE_EARLY))
372 return t;
373 return NULL;
374}
375
376/*
377 * Determine whether a given process is "early kill" process which expects
378 * to be signaled when some page under the process is hwpoisoned.
379 * Return task_struct of the dedicated thread (main thread unless explicitly
380 * specified) if the process is "early kill," and otherwise returns NULL.
381 */
382static struct task_struct *task_early_kill(struct task_struct *tsk,
383 int force_early)
384{
385 struct task_struct *t;
Andi Kleen6a460792009-09-16 11:50:15 +0200386 if (!tsk->mm)
Naoya Horiguchi3ba08122014-06-04 16:11:02 -0700387 return NULL;
Tony Luck74614de2014-06-04 16:11:01 -0700388 if (force_early)
Naoya Horiguchi3ba08122014-06-04 16:11:02 -0700389 return tsk;
390 t = find_early_kill_thread(tsk);
391 if (t)
392 return t;
393 if (sysctl_memory_failure_early_kill)
394 return tsk;
395 return NULL;
Andi Kleen6a460792009-09-16 11:50:15 +0200396}
397
398/*
399 * Collect processes when the error hit an anonymous page.
400 */
401static void collect_procs_anon(struct page *page, struct list_head *to_kill,
Tony Luck74614de2014-06-04 16:11:01 -0700402 struct to_kill **tkc, int force_early)
Andi Kleen6a460792009-09-16 11:50:15 +0200403{
404 struct vm_area_struct *vma;
405 struct task_struct *tsk;
406 struct anon_vma *av;
Michel Lespinassebf181b92012-10-08 16:31:39 -0700407 pgoff_t pgoff;
Andi Kleen6a460792009-09-16 11:50:15 +0200408
Ingo Molnar4fc3f1d2012-12-02 19:56:50 +0000409 av = page_lock_anon_vma_read(page);
Andi Kleen6a460792009-09-16 11:50:15 +0200410 if (av == NULL) /* Not actually mapped anymore */
Peter Zijlstra9b679322011-06-27 16:18:09 -0700411 return;
412
Naoya Horiguchia0f7a752014-07-23 14:00:01 -0700413 pgoff = page_to_pgoff(page);
Peter Zijlstra9b679322011-06-27 16:18:09 -0700414 read_lock(&tasklist_lock);
Andi Kleen6a460792009-09-16 11:50:15 +0200415 for_each_process (tsk) {
Rik van Riel5beb4932010-03-05 13:42:07 -0800416 struct anon_vma_chain *vmac;
Naoya Horiguchi3ba08122014-06-04 16:11:02 -0700417 struct task_struct *t = task_early_kill(tsk, force_early);
Rik van Riel5beb4932010-03-05 13:42:07 -0800418
Naoya Horiguchi3ba08122014-06-04 16:11:02 -0700419 if (!t)
Andi Kleen6a460792009-09-16 11:50:15 +0200420 continue;
Michel Lespinassebf181b92012-10-08 16:31:39 -0700421 anon_vma_interval_tree_foreach(vmac, &av->rb_root,
422 pgoff, pgoff) {
Rik van Riel5beb4932010-03-05 13:42:07 -0800423 vma = vmac->vma;
Andi Kleen6a460792009-09-16 11:50:15 +0200424 if (!page_mapped_in_vma(page, vma))
425 continue;
Naoya Horiguchi3ba08122014-06-04 16:11:02 -0700426 if (vma->vm_mm == t->mm)
427 add_to_kill(t, page, vma, to_kill, tkc);
Andi Kleen6a460792009-09-16 11:50:15 +0200428 }
429 }
Andi Kleen6a460792009-09-16 11:50:15 +0200430 read_unlock(&tasklist_lock);
Ingo Molnar4fc3f1d2012-12-02 19:56:50 +0000431 page_unlock_anon_vma_read(av);
Andi Kleen6a460792009-09-16 11:50:15 +0200432}
433
434/*
435 * Collect processes when the error hit a file mapped page.
436 */
437static void collect_procs_file(struct page *page, struct list_head *to_kill,
Tony Luck74614de2014-06-04 16:11:01 -0700438 struct to_kill **tkc, int force_early)
Andi Kleen6a460792009-09-16 11:50:15 +0200439{
440 struct vm_area_struct *vma;
441 struct task_struct *tsk;
Andi Kleen6a460792009-09-16 11:50:15 +0200442 struct address_space *mapping = page->mapping;
443
Davidlohr Buesod28eb9c2014-12-12 16:54:36 -0800444 i_mmap_lock_read(mapping);
Peter Zijlstra9b679322011-06-27 16:18:09 -0700445 read_lock(&tasklist_lock);
Andi Kleen6a460792009-09-16 11:50:15 +0200446 for_each_process(tsk) {
Naoya Horiguchia0f7a752014-07-23 14:00:01 -0700447 pgoff_t pgoff = page_to_pgoff(page);
Naoya Horiguchi3ba08122014-06-04 16:11:02 -0700448 struct task_struct *t = task_early_kill(tsk, force_early);
Andi Kleen6a460792009-09-16 11:50:15 +0200449
Naoya Horiguchi3ba08122014-06-04 16:11:02 -0700450 if (!t)
Andi Kleen6a460792009-09-16 11:50:15 +0200451 continue;
Michel Lespinasse6b2dbba2012-10-08 16:31:25 -0700452 vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff,
Andi Kleen6a460792009-09-16 11:50:15 +0200453 pgoff) {
454 /*
455 * Send early kill signal to tasks where a vma covers
456 * the page but the corrupted page is not necessarily
457 * mapped it in its pte.
458 * Assume applications who requested early kill want
459 * to be informed of all such data corruptions.
460 */
Naoya Horiguchi3ba08122014-06-04 16:11:02 -0700461 if (vma->vm_mm == t->mm)
462 add_to_kill(t, page, vma, to_kill, tkc);
Andi Kleen6a460792009-09-16 11:50:15 +0200463 }
464 }
Andi Kleen6a460792009-09-16 11:50:15 +0200465 read_unlock(&tasklist_lock);
Davidlohr Buesod28eb9c2014-12-12 16:54:36 -0800466 i_mmap_unlock_read(mapping);
Andi Kleen6a460792009-09-16 11:50:15 +0200467}
468
469/*
470 * Collect the processes who have the corrupted page mapped to kill.
471 * This is done in two steps for locking reasons.
472 * First preallocate one tokill structure outside the spin locks,
473 * so that we can kill at least one process reasonably reliable.
474 */
Tony Luck74614de2014-06-04 16:11:01 -0700475static void collect_procs(struct page *page, struct list_head *tokill,
476 int force_early)
Andi Kleen6a460792009-09-16 11:50:15 +0200477{
478 struct to_kill *tk;
479
480 if (!page->mapping)
481 return;
482
483 tk = kmalloc(sizeof(struct to_kill), GFP_NOIO);
484 if (!tk)
485 return;
486 if (PageAnon(page))
Tony Luck74614de2014-06-04 16:11:01 -0700487 collect_procs_anon(page, tokill, &tk, force_early);
Andi Kleen6a460792009-09-16 11:50:15 +0200488 else
Tony Luck74614de2014-06-04 16:11:01 -0700489 collect_procs_file(page, tokill, &tk, force_early);
Andi Kleen6a460792009-09-16 11:50:15 +0200490 kfree(tk);
491}
492
Andi Kleen6a460792009-09-16 11:50:15 +0200493static const char *action_name[] = {
Xie XiuQicc637b12015-06-24 16:57:30 -0700494 [MF_IGNORED] = "Ignored",
495 [MF_FAILED] = "Failed",
496 [MF_DELAYED] = "Delayed",
497 [MF_RECOVERED] = "Recovered",
Naoya Horiguchi64d37a22015-04-15 16:13:05 -0700498};
499
500static const char * const action_page_types[] = {
Xie XiuQicc637b12015-06-24 16:57:30 -0700501 [MF_MSG_KERNEL] = "reserved kernel page",
502 [MF_MSG_KERNEL_HIGH_ORDER] = "high-order kernel page",
503 [MF_MSG_SLAB] = "kernel slab page",
504 [MF_MSG_DIFFERENT_COMPOUND] = "different compound page after locking",
505 [MF_MSG_POISONED_HUGE] = "huge page already hardware poisoned",
506 [MF_MSG_HUGE] = "huge page",
507 [MF_MSG_FREE_HUGE] = "free huge page",
508 [MF_MSG_UNMAP_FAILED] = "unmapping failed page",
509 [MF_MSG_DIRTY_SWAPCACHE] = "dirty swapcache page",
510 [MF_MSG_CLEAN_SWAPCACHE] = "clean swapcache page",
511 [MF_MSG_DIRTY_MLOCKED_LRU] = "dirty mlocked LRU page",
512 [MF_MSG_CLEAN_MLOCKED_LRU] = "clean mlocked LRU page",
513 [MF_MSG_DIRTY_UNEVICTABLE_LRU] = "dirty unevictable LRU page",
514 [MF_MSG_CLEAN_UNEVICTABLE_LRU] = "clean unevictable LRU page",
515 [MF_MSG_DIRTY_LRU] = "dirty LRU page",
516 [MF_MSG_CLEAN_LRU] = "clean LRU page",
517 [MF_MSG_TRUNCATED_LRU] = "already truncated LRU page",
518 [MF_MSG_BUDDY] = "free buddy page",
519 [MF_MSG_BUDDY_2ND] = "free buddy page (2nd try)",
520 [MF_MSG_UNKNOWN] = "unknown page",
Naoya Horiguchi64d37a22015-04-15 16:13:05 -0700521};
522
Andi Kleen6a460792009-09-16 11:50:15 +0200523/*
Wu Fengguangdc2a1cb2009-12-16 12:19:58 +0100524 * XXX: It is possible that a page is isolated from LRU cache,
525 * and then kept in swap cache or failed to remove from page cache.
526 * The page count will stop it from being freed by unpoison.
527 * Stress tests should be aware of this memory leak problem.
528 */
529static int delete_from_lru_cache(struct page *p)
530{
531 if (!isolate_lru_page(p)) {
532 /*
533 * Clear sensible page flags, so that the buddy system won't
534 * complain when the page is unpoison-and-freed.
535 */
536 ClearPageActive(p);
537 ClearPageUnevictable(p);
538 /*
539 * drop the page count elevated by isolate_lru_page()
540 */
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300541 put_page(p);
Wu Fengguangdc2a1cb2009-12-16 12:19:58 +0100542 return 0;
543 }
544 return -EIO;
545}
546
547/*
Andi Kleen6a460792009-09-16 11:50:15 +0200548 * Error hit kernel page.
549 * Do nothing, try to be lucky and not touch this instead. For a few cases we
550 * could be more sophisticated.
551 */
552static int me_kernel(struct page *p, unsigned long pfn)
553{
Xie XiuQicc637b12015-06-24 16:57:30 -0700554 return MF_IGNORED;
Andi Kleen6a460792009-09-16 11:50:15 +0200555}
556
557/*
558 * Page in unknown state. Do nothing.
559 */
560static int me_unknown(struct page *p, unsigned long pfn)
561{
Chen Yucong495367c02016-05-20 16:57:32 -0700562 pr_err("Memory failure: %#lx: Unknown page state\n", pfn);
Xie XiuQicc637b12015-06-24 16:57:30 -0700563 return MF_FAILED;
Andi Kleen6a460792009-09-16 11:50:15 +0200564}
565
566/*
Andi Kleen6a460792009-09-16 11:50:15 +0200567 * Clean (or cleaned) page cache page.
568 */
569static int me_pagecache_clean(struct page *p, unsigned long pfn)
570{
571 int err;
Xie XiuQicc637b12015-06-24 16:57:30 -0700572 int ret = MF_FAILED;
Andi Kleen6a460792009-09-16 11:50:15 +0200573 struct address_space *mapping;
574
Wu Fengguangdc2a1cb2009-12-16 12:19:58 +0100575 delete_from_lru_cache(p);
576
Andi Kleen6a460792009-09-16 11:50:15 +0200577 /*
578 * For anonymous pages we're done the only reference left
579 * should be the one m_f() holds.
580 */
581 if (PageAnon(p))
Xie XiuQicc637b12015-06-24 16:57:30 -0700582 return MF_RECOVERED;
Andi Kleen6a460792009-09-16 11:50:15 +0200583
584 /*
585 * Now truncate the page in the page cache. This is really
586 * more like a "temporary hole punch"
587 * Don't do this for block devices when someone else
588 * has a reference, because it could be file system metadata
589 * and that's not safe to truncate.
590 */
591 mapping = page_mapping(p);
592 if (!mapping) {
593 /*
594 * Page has been teared down in the meanwhile
595 */
Xie XiuQicc637b12015-06-24 16:57:30 -0700596 return MF_FAILED;
Andi Kleen6a460792009-09-16 11:50:15 +0200597 }
598
599 /*
600 * Truncation is a bit tricky. Enable it per file system for now.
601 *
602 * Open: to take i_mutex or not for this? Right now we don't.
603 */
604 if (mapping->a_ops->error_remove_page) {
605 err = mapping->a_ops->error_remove_page(mapping, p);
606 if (err != 0) {
Chen Yucong495367c02016-05-20 16:57:32 -0700607 pr_info("Memory failure: %#lx: Failed to punch page: %d\n",
Joe Perches11705322016-03-17 14:19:50 -0700608 pfn, err);
Andi Kleen6a460792009-09-16 11:50:15 +0200609 } else if (page_has_private(p) &&
610 !try_to_release_page(p, GFP_NOIO)) {
Chen Yucong495367c02016-05-20 16:57:32 -0700611 pr_info("Memory failure: %#lx: failed to release buffers\n",
612 pfn);
Andi Kleen6a460792009-09-16 11:50:15 +0200613 } else {
Xie XiuQicc637b12015-06-24 16:57:30 -0700614 ret = MF_RECOVERED;
Andi Kleen6a460792009-09-16 11:50:15 +0200615 }
616 } else {
617 /*
618 * If the file system doesn't support it just invalidate
619 * This fails on dirty or anything with private pages
620 */
621 if (invalidate_inode_page(p))
Xie XiuQicc637b12015-06-24 16:57:30 -0700622 ret = MF_RECOVERED;
Andi Kleen6a460792009-09-16 11:50:15 +0200623 else
Chen Yucong495367c02016-05-20 16:57:32 -0700624 pr_info("Memory failure: %#lx: Failed to invalidate\n",
625 pfn);
Andi Kleen6a460792009-09-16 11:50:15 +0200626 }
627 return ret;
628}
629
630/*
Zhi Yong Wu549543d2014-01-21 15:49:08 -0800631 * Dirty pagecache page
Andi Kleen6a460792009-09-16 11:50:15 +0200632 * Issues: when the error hit a hole page the error is not properly
633 * propagated.
634 */
635static int me_pagecache_dirty(struct page *p, unsigned long pfn)
636{
637 struct address_space *mapping = page_mapping(p);
638
639 SetPageError(p);
640 /* TBD: print more information about the file. */
641 if (mapping) {
642 /*
643 * IO error will be reported by write(), fsync(), etc.
644 * who check the mapping.
645 * This way the application knows that something went
646 * wrong with its dirty file data.
647 *
648 * There's one open issue:
649 *
650 * The EIO will be only reported on the next IO
651 * operation and then cleared through the IO map.
652 * Normally Linux has two mechanisms to pass IO error
653 * first through the AS_EIO flag in the address space
654 * and then through the PageError flag in the page.
655 * Since we drop pages on memory failure handling the
656 * only mechanism open to use is through AS_AIO.
657 *
658 * This has the disadvantage that it gets cleared on
659 * the first operation that returns an error, while
660 * the PageError bit is more sticky and only cleared
661 * when the page is reread or dropped. If an
662 * application assumes it will always get error on
663 * fsync, but does other operations on the fd before
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300664 * and the page is dropped between then the error
Andi Kleen6a460792009-09-16 11:50:15 +0200665 * will not be properly reported.
666 *
667 * This can already happen even without hwpoisoned
668 * pages: first on metadata IO errors (which only
669 * report through AS_EIO) or when the page is dropped
670 * at the wrong time.
671 *
672 * So right now we assume that the application DTRT on
673 * the first EIO, but we're not worse than other parts
674 * of the kernel.
675 */
676 mapping_set_error(mapping, EIO);
677 }
678
679 return me_pagecache_clean(p, pfn);
680}
681
682/*
683 * Clean and dirty swap cache.
684 *
685 * Dirty swap cache page is tricky to handle. The page could live both in page
686 * cache and swap cache(ie. page is freshly swapped in). So it could be
687 * referenced concurrently by 2 types of PTEs:
688 * normal PTEs and swap PTEs. We try to handle them consistently by calling
689 * try_to_unmap(TTU_IGNORE_HWPOISON) to convert the normal PTEs to swap PTEs,
690 * and then
691 * - clear dirty bit to prevent IO
692 * - remove from LRU
693 * - but keep in the swap cache, so that when we return to it on
694 * a later page fault, we know the application is accessing
695 * corrupted data and shall be killed (we installed simple
696 * interception code in do_swap_page to catch it).
697 *
698 * Clean swap cache pages can be directly isolated. A later page fault will
699 * bring in the known good data from disk.
700 */
701static int me_swapcache_dirty(struct page *p, unsigned long pfn)
702{
Andi Kleen6a460792009-09-16 11:50:15 +0200703 ClearPageDirty(p);
704 /* Trigger EIO in shmem: */
705 ClearPageUptodate(p);
706
Wu Fengguangdc2a1cb2009-12-16 12:19:58 +0100707 if (!delete_from_lru_cache(p))
Xie XiuQicc637b12015-06-24 16:57:30 -0700708 return MF_DELAYED;
Wu Fengguangdc2a1cb2009-12-16 12:19:58 +0100709 else
Xie XiuQicc637b12015-06-24 16:57:30 -0700710 return MF_FAILED;
Andi Kleen6a460792009-09-16 11:50:15 +0200711}
712
713static int me_swapcache_clean(struct page *p, unsigned long pfn)
714{
Andi Kleen6a460792009-09-16 11:50:15 +0200715 delete_from_swap_cache(p);
Wu Fengguange43c3af2009-09-29 13:16:20 +0800716
Wu Fengguangdc2a1cb2009-12-16 12:19:58 +0100717 if (!delete_from_lru_cache(p))
Xie XiuQicc637b12015-06-24 16:57:30 -0700718 return MF_RECOVERED;
Wu Fengguangdc2a1cb2009-12-16 12:19:58 +0100719 else
Xie XiuQicc637b12015-06-24 16:57:30 -0700720 return MF_FAILED;
Andi Kleen6a460792009-09-16 11:50:15 +0200721}
722
723/*
724 * Huge pages. Needs work.
725 * Issues:
Naoya Horiguchi93f70f92010-05-28 09:29:20 +0900726 * - Error on hugepage is contained in hugepage unit (not in raw page unit.)
727 * To narrow down kill region to one page, we need to break up pmd.
Andi Kleen6a460792009-09-16 11:50:15 +0200728 */
729static int me_huge_page(struct page *p, unsigned long pfn)
730{
Naoya Horiguchi6de2b1a2010-09-08 10:19:36 +0900731 int res = 0;
Naoya Horiguchi93f70f92010-05-28 09:29:20 +0900732 struct page *hpage = compound_head(p);
Naoya Horiguchi2491ffe2015-06-24 16:56:53 -0700733
734 if (!PageHuge(hpage))
735 return MF_DELAYED;
736
Naoya Horiguchi93f70f92010-05-28 09:29:20 +0900737 /*
738 * We can safely recover from error on free or reserved (i.e.
739 * not in-use) hugepage by dequeuing it from freelist.
740 * To check whether a hugepage is in-use or not, we can't use
741 * page->lru because it can be used in other hugepage operations,
742 * such as __unmap_hugepage_range() and gather_surplus_pages().
743 * So instead we use page_mapping() and PageAnon().
Naoya Horiguchi93f70f92010-05-28 09:29:20 +0900744 */
745 if (!(page_mapping(hpage) || PageAnon(hpage))) {
Naoya Horiguchi6de2b1a2010-09-08 10:19:36 +0900746 res = dequeue_hwpoisoned_huge_page(hpage);
747 if (!res)
Xie XiuQicc637b12015-06-24 16:57:30 -0700748 return MF_RECOVERED;
Naoya Horiguchi93f70f92010-05-28 09:29:20 +0900749 }
Xie XiuQicc637b12015-06-24 16:57:30 -0700750 return MF_DELAYED;
Andi Kleen6a460792009-09-16 11:50:15 +0200751}
752
753/*
754 * Various page states we can handle.
755 *
756 * A page state is defined by its current page->flags bits.
757 * The table matches them in order and calls the right handler.
758 *
759 * This is quite tricky because we can access page at any time
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300760 * in its live cycle, so all accesses have to be extremely careful.
Andi Kleen6a460792009-09-16 11:50:15 +0200761 *
762 * This is not complete. More states could be added.
763 * For any missing state don't attempt recovery.
764 */
765
766#define dirty (1UL << PG_dirty)
767#define sc (1UL << PG_swapcache)
768#define unevict (1UL << PG_unevictable)
769#define mlock (1UL << PG_mlocked)
770#define writeback (1UL << PG_writeback)
771#define lru (1UL << PG_lru)
772#define swapbacked (1UL << PG_swapbacked)
773#define head (1UL << PG_head)
Andi Kleen6a460792009-09-16 11:50:15 +0200774#define slab (1UL << PG_slab)
Andi Kleen6a460792009-09-16 11:50:15 +0200775#define reserved (1UL << PG_reserved)
776
777static struct page_state {
778 unsigned long mask;
779 unsigned long res;
Xie XiuQicc637b12015-06-24 16:57:30 -0700780 enum mf_action_page_type type;
Andi Kleen6a460792009-09-16 11:50:15 +0200781 int (*action)(struct page *p, unsigned long pfn);
782} error_states[] = {
Xie XiuQicc637b12015-06-24 16:57:30 -0700783 { reserved, reserved, MF_MSG_KERNEL, me_kernel },
Wu Fengguang95d01fc2009-12-16 12:19:58 +0100784 /*
785 * free pages are specially detected outside this table:
786 * PG_buddy pages only make a small fraction of all free pages.
787 */
Andi Kleen6a460792009-09-16 11:50:15 +0200788
789 /*
790 * Could in theory check if slab page is free or if we can drop
791 * currently unused objects without touching them. But just
792 * treat it as standard kernel for now.
793 */
Xie XiuQicc637b12015-06-24 16:57:30 -0700794 { slab, slab, MF_MSG_SLAB, me_kernel },
Andi Kleen6a460792009-09-16 11:50:15 +0200795
Xie XiuQicc637b12015-06-24 16:57:30 -0700796 { head, head, MF_MSG_HUGE, me_huge_page },
Andi Kleen6a460792009-09-16 11:50:15 +0200797
Xie XiuQicc637b12015-06-24 16:57:30 -0700798 { sc|dirty, sc|dirty, MF_MSG_DIRTY_SWAPCACHE, me_swapcache_dirty },
799 { sc|dirty, sc, MF_MSG_CLEAN_SWAPCACHE, me_swapcache_clean },
Andi Kleen6a460792009-09-16 11:50:15 +0200800
Xie XiuQicc637b12015-06-24 16:57:30 -0700801 { mlock|dirty, mlock|dirty, MF_MSG_DIRTY_MLOCKED_LRU, me_pagecache_dirty },
802 { mlock|dirty, mlock, MF_MSG_CLEAN_MLOCKED_LRU, me_pagecache_clean },
Andi Kleen6a460792009-09-16 11:50:15 +0200803
Xie XiuQicc637b12015-06-24 16:57:30 -0700804 { unevict|dirty, unevict|dirty, MF_MSG_DIRTY_UNEVICTABLE_LRU, me_pagecache_dirty },
805 { unevict|dirty, unevict, MF_MSG_CLEAN_UNEVICTABLE_LRU, me_pagecache_clean },
Naoya Horiguchi5f4b9fc2013-02-22 16:35:53 -0800806
Xie XiuQicc637b12015-06-24 16:57:30 -0700807 { lru|dirty, lru|dirty, MF_MSG_DIRTY_LRU, me_pagecache_dirty },
808 { lru|dirty, lru, MF_MSG_CLEAN_LRU, me_pagecache_clean },
Andi Kleen6a460792009-09-16 11:50:15 +0200809
810 /*
811 * Catchall entry: must be at end.
812 */
Xie XiuQicc637b12015-06-24 16:57:30 -0700813 { 0, 0, MF_MSG_UNKNOWN, me_unknown },
Andi Kleen6a460792009-09-16 11:50:15 +0200814};
815
Andi Kleen2326c462009-12-16 12:20:00 +0100816#undef dirty
817#undef sc
818#undef unevict
819#undef mlock
820#undef writeback
821#undef lru
822#undef swapbacked
823#undef head
Andi Kleen2326c462009-12-16 12:20:00 +0100824#undef slab
825#undef reserved
826
Naoya Horiguchiff604cf2012-12-11 16:01:32 -0800827/*
828 * "Dirty/Clean" indication is not 100% accurate due to the possibility of
829 * setting PG_dirty outside page lock. See also comment above set_page_dirty().
830 */
Xie XiuQicc3e2af2015-06-24 16:57:33 -0700831static void action_result(unsigned long pfn, enum mf_action_page_type type,
832 enum mf_result result)
Andi Kleen6a460792009-09-16 11:50:15 +0200833{
Xie XiuQi97f0b132015-06-24 16:57:36 -0700834 trace_memory_failure_event(pfn, type, result);
835
Chen Yucong495367c02016-05-20 16:57:32 -0700836 pr_err("Memory failure: %#lx: recovery action for %s: %s\n",
Naoya Horiguchi64d37a22015-04-15 16:13:05 -0700837 pfn, action_page_types[type], action_name[result]);
Andi Kleen6a460792009-09-16 11:50:15 +0200838}
839
840static int page_action(struct page_state *ps, struct page *p,
Wu Fengguangbd1ce5f2009-12-16 12:19:57 +0100841 unsigned long pfn)
Andi Kleen6a460792009-09-16 11:50:15 +0200842{
843 int result;
Wu Fengguang7456b042009-10-19 08:15:01 +0200844 int count;
Andi Kleen6a460792009-09-16 11:50:15 +0200845
846 result = ps->action(p, pfn);
Wu Fengguang7456b042009-10-19 08:15:01 +0200847
Wu Fengguangbd1ce5f2009-12-16 12:19:57 +0100848 count = page_count(p) - 1;
Xie XiuQicc637b12015-06-24 16:57:30 -0700849 if (ps->action == me_swapcache_dirty && result == MF_DELAYED)
Wu Fengguang138ce282009-12-16 12:19:58 +0100850 count--;
851 if (count != 0) {
Chen Yucong495367c02016-05-20 16:57:32 -0700852 pr_err("Memory failure: %#lx: %s still referenced by %d users\n",
Naoya Horiguchi64d37a22015-04-15 16:13:05 -0700853 pfn, action_page_types[ps->type], count);
Xie XiuQicc637b12015-06-24 16:57:30 -0700854 result = MF_FAILED;
Wu Fengguang138ce282009-12-16 12:19:58 +0100855 }
Naoya Horiguchi64d37a22015-04-15 16:13:05 -0700856 action_result(pfn, ps->type, result);
Andi Kleen6a460792009-09-16 11:50:15 +0200857
858 /* Could do more checks here if page looks ok */
859 /*
860 * Could adjust zone counters here to correct for the missing page.
861 */
862
Xie XiuQicc637b12015-06-24 16:57:30 -0700863 return (result == MF_RECOVERED || result == MF_DELAYED) ? 0 : -EBUSY;
Andi Kleen6a460792009-09-16 11:50:15 +0200864}
865
Naoya Horiguchiead07f62015-06-24 16:56:48 -0700866/**
867 * get_hwpoison_page() - Get refcount for memory error handling:
868 * @page: raw error page (hit by memory error)
869 *
870 * Return: return 0 if failed to grab the refcount, otherwise true (some
871 * non-zero value.)
872 */
873int get_hwpoison_page(struct page *page)
874{
875 struct page *head = compound_head(page);
876
Naoya Horiguchi4e41a302016-01-15 16:54:07 -0800877 if (!PageHuge(head) && PageTransHuge(head)) {
Naoya Horiguchi98ed2b02015-08-06 15:47:04 -0700878 /*
879 * Non anonymous thp exists only in allocation/free time. We
880 * can't handle such a case correctly, so let's give it up.
881 * This should be better than triggering BUG_ON when kernel
882 * tries to touch the "partially handled" page.
883 */
884 if (!PageAnon(head)) {
Chen Yucong495367c02016-05-20 16:57:32 -0700885 pr_err("Memory failure: %#lx: non anonymous thp\n",
Naoya Horiguchi98ed2b02015-08-06 15:47:04 -0700886 page_to_pfn(page));
887 return 0;
888 }
Naoya Horiguchiead07f62015-06-24 16:56:48 -0700889 }
890
Konstantin Khlebnikovc2e7e002016-04-28 16:19:03 -0700891 if (get_page_unless_zero(head)) {
892 if (head == compound_head(page))
893 return 1;
894
Chen Yucong495367c02016-05-20 16:57:32 -0700895 pr_info("Memory failure: %#lx cannot catch tail\n",
896 page_to_pfn(page));
Konstantin Khlebnikovc2e7e002016-04-28 16:19:03 -0700897 put_page(head);
898 }
899
900 return 0;
Naoya Horiguchiead07f62015-06-24 16:56:48 -0700901}
902EXPORT_SYMBOL_GPL(get_hwpoison_page);
903
Andi Kleen6a460792009-09-16 11:50:15 +0200904/*
905 * Do all that is necessary to remove user space mappings. Unmap
906 * the pages and send SIGBUS to the processes if the data was dirty.
907 */
Wu Fengguang1668bfd2009-12-16 12:19:58 +0100908static int hwpoison_user_mappings(struct page *p, unsigned long pfn,
Naoya Horiguchi54b9dd12014-01-23 15:53:14 -0800909 int trapno, int flags, struct page **hpagep)
Andi Kleen6a460792009-09-16 11:50:15 +0200910{
911 enum ttu_flags ttu = TTU_UNMAP | TTU_IGNORE_MLOCK | TTU_IGNORE_ACCESS;
912 struct address_space *mapping;
913 LIST_HEAD(tokill);
914 int ret;
Tony Luck6751ed62012-07-11 10:20:47 -0700915 int kill = 1, forcekill;
Naoya Horiguchi54b9dd12014-01-23 15:53:14 -0800916 struct page *hpage = *hpagep;
Andi Kleen6a460792009-09-16 11:50:15 +0200917
Naoya Horiguchi93a9eb32014-07-30 16:08:28 -0700918 /*
919 * Here we are interested only in user-mapped pages, so skip any
920 * other types of pages.
921 */
922 if (PageReserved(p) || PageSlab(p))
923 return SWAP_SUCCESS;
924 if (!(PageLRU(hpage) || PageHuge(p)))
Wu Fengguang1668bfd2009-12-16 12:19:58 +0100925 return SWAP_SUCCESS;
Andi Kleen6a460792009-09-16 11:50:15 +0200926
Andi Kleen6a460792009-09-16 11:50:15 +0200927 /*
928 * This check implies we don't kill processes if their pages
929 * are in the swap cache early. Those are always late kills.
930 */
Naoya Horiguchi7af446a2010-05-28 09:29:17 +0900931 if (!page_mapped(hpage))
Wu Fengguang1668bfd2009-12-16 12:19:58 +0100932 return SWAP_SUCCESS;
933
Naoya Horiguchi52089b12014-07-30 16:08:30 -0700934 if (PageKsm(p)) {
Chen Yucong495367c02016-05-20 16:57:32 -0700935 pr_err("Memory failure: %#lx: can't handle KSM pages.\n", pfn);
Wu Fengguang1668bfd2009-12-16 12:19:58 +0100936 return SWAP_FAIL;
Naoya Horiguchi52089b12014-07-30 16:08:30 -0700937 }
Andi Kleen6a460792009-09-16 11:50:15 +0200938
939 if (PageSwapCache(p)) {
Chen Yucong495367c02016-05-20 16:57:32 -0700940 pr_err("Memory failure: %#lx: keeping poisoned page in swap cache\n",
941 pfn);
Andi Kleen6a460792009-09-16 11:50:15 +0200942 ttu |= TTU_IGNORE_HWPOISON;
943 }
944
945 /*
946 * Propagate the dirty bit from PTEs to struct page first, because we
947 * need this to decide if we should kill or just drop the page.
Wu Fengguangdb0480b2009-12-16 12:19:58 +0100948 * XXX: the dirty test could be racy: set_page_dirty() may not always
949 * be called inside page lock (it's recommended but not enforced).
Andi Kleen6a460792009-09-16 11:50:15 +0200950 */
Naoya Horiguchi7af446a2010-05-28 09:29:17 +0900951 mapping = page_mapping(hpage);
Tony Luck6751ed62012-07-11 10:20:47 -0700952 if (!(flags & MF_MUST_KILL) && !PageDirty(hpage) && mapping &&
Naoya Horiguchi7af446a2010-05-28 09:29:17 +0900953 mapping_cap_writeback_dirty(mapping)) {
954 if (page_mkclean(hpage)) {
955 SetPageDirty(hpage);
Andi Kleen6a460792009-09-16 11:50:15 +0200956 } else {
957 kill = 0;
958 ttu |= TTU_IGNORE_HWPOISON;
Chen Yucong495367c02016-05-20 16:57:32 -0700959 pr_info("Memory failure: %#lx: corrupted page was clean: dropped without side effects\n",
Andi Kleen6a460792009-09-16 11:50:15 +0200960 pfn);
961 }
962 }
963
Jin Dongminga6d30dd2011-02-01 15:52:40 -0800964 /*
Andi Kleen6a460792009-09-16 11:50:15 +0200965 * First collect all the processes that have the page
966 * mapped in dirty form. This has to be done before try_to_unmap,
967 * because ttu takes the rmap data structures down.
968 *
969 * Error handling: We ignore errors here because
970 * there's nothing that can be done.
971 */
972 if (kill)
Naoya Horiguchi415c64c2015-06-24 16:56:45 -0700973 collect_procs(hpage, &tokill, flags & MF_ACTION_REQUIRED);
Andi Kleen6a460792009-09-16 11:50:15 +0200974
Naoya Horiguchi415c64c2015-06-24 16:56:45 -0700975 ret = try_to_unmap(hpage, ttu);
Andi Kleen6a460792009-09-16 11:50:15 +0200976 if (ret != SWAP_SUCCESS)
Chen Yucong495367c02016-05-20 16:57:32 -0700977 pr_err("Memory failure: %#lx: failed to unmap page (mapcount=%d)\n",
Joe Perches11705322016-03-17 14:19:50 -0700978 pfn, page_mapcount(hpage));
Jin Dongminga6d30dd2011-02-01 15:52:40 -0800979
Andi Kleen6a460792009-09-16 11:50:15 +0200980 /*
981 * Now that the dirty bit has been propagated to the
982 * struct page and all unmaps done we can decide if
983 * killing is needed or not. Only kill when the page
Tony Luck6751ed62012-07-11 10:20:47 -0700984 * was dirty or the process is not restartable,
985 * otherwise the tokill list is merely
Andi Kleen6a460792009-09-16 11:50:15 +0200986 * freed. When there was a problem unmapping earlier
987 * use a more force-full uncatchable kill to prevent
988 * any accesses to the poisoned memory.
989 */
Naoya Horiguchi415c64c2015-06-24 16:56:45 -0700990 forcekill = PageDirty(hpage) || (flags & MF_MUST_KILL);
Tony Luck6751ed62012-07-11 10:20:47 -0700991 kill_procs(&tokill, forcekill, trapno,
Tony Luck7329bbe2011-12-13 09:27:58 -0800992 ret != SWAP_SUCCESS, p, pfn, flags);
Wu Fengguang1668bfd2009-12-16 12:19:58 +0100993
994 return ret;
Andi Kleen6a460792009-09-16 11:50:15 +0200995}
996
Naoya Horiguchi7013feb2010-05-28 09:29:18 +0900997static void set_page_hwpoison_huge_page(struct page *hpage)
998{
999 int i;
Wanpeng Lif9121152013-09-11 14:22:52 -07001000 int nr_pages = 1 << compound_order(hpage);
Naoya Horiguchi7013feb2010-05-28 09:29:18 +09001001 for (i = 0; i < nr_pages; i++)
1002 SetPageHWPoison(hpage + i);
1003}
1004
1005static void clear_page_hwpoison_huge_page(struct page *hpage)
1006{
1007 int i;
Wanpeng Lif9121152013-09-11 14:22:52 -07001008 int nr_pages = 1 << compound_order(hpage);
Naoya Horiguchi7013feb2010-05-28 09:29:18 +09001009 for (i = 0; i < nr_pages; i++)
1010 ClearPageHWPoison(hpage + i);
1011}
1012
Tony Luckcd42f4a2011-12-15 10:48:12 -08001013/**
1014 * memory_failure - Handle memory failure of a page.
1015 * @pfn: Page Number of the corrupted page
1016 * @trapno: Trap number reported in the signal to user space.
1017 * @flags: fine tune action taken
1018 *
1019 * This function is called by the low level machine check code
1020 * of an architecture when it detects hardware memory corruption
1021 * of a page. It tries its best to recover, which includes
1022 * dropping pages, killing processes etc.
1023 *
1024 * The function is primarily of use for corruptions that
1025 * happen outside the current execution context (e.g. when
1026 * detected by a background scrubber)
1027 *
1028 * Must run in process context (e.g. a work queue) with interrupts
1029 * enabled and no spinlocks hold.
1030 */
1031int memory_failure(unsigned long pfn, int trapno, int flags)
Andi Kleen6a460792009-09-16 11:50:15 +02001032{
1033 struct page_state *ps;
1034 struct page *p;
Naoya Horiguchi7af446a2010-05-28 09:29:17 +09001035 struct page *hpage;
Naoya Horiguchi415c64c2015-06-24 16:56:45 -07001036 struct page *orig_head;
Andi Kleen6a460792009-09-16 11:50:15 +02001037 int res;
Naoya Horiguchic9fbdd52010-05-28 09:29:19 +09001038 unsigned int nr_pages;
Naoya Horiguchi524fca12013-02-22 16:35:51 -08001039 unsigned long page_flags;
Andi Kleen6a460792009-09-16 11:50:15 +02001040
1041 if (!sysctl_memory_failure_recovery)
1042 panic("Memory failure from trap %d on page %lx", trapno, pfn);
1043
1044 if (!pfn_valid(pfn)) {
Chen Yucong495367c02016-05-20 16:57:32 -07001045 pr_err("Memory failure: %#lx: memory outside kernel control\n",
1046 pfn);
Wu Fengguanga7560fc2009-12-16 12:19:57 +01001047 return -ENXIO;
Andi Kleen6a460792009-09-16 11:50:15 +02001048 }
1049
1050 p = pfn_to_page(pfn);
Naoya Horiguchi415c64c2015-06-24 16:56:45 -07001051 orig_head = hpage = compound_head(p);
Andi Kleen6a460792009-09-16 11:50:15 +02001052 if (TestSetPageHWPoison(p)) {
Chen Yucong495367c02016-05-20 16:57:32 -07001053 pr_err("Memory failure: %#lx: already hardware poisoned\n",
1054 pfn);
Andi Kleen6a460792009-09-16 11:50:15 +02001055 return 0;
1056 }
1057
Naoya Horiguchi4db0e952013-02-22 16:34:05 -08001058 /*
1059 * Currently errors on hugetlbfs pages are measured in hugepage units,
1060 * so nr_pages should be 1 << compound_order. OTOH when errors are on
1061 * transparent hugepages, they are supposed to be split and error
1062 * measurement is done in normal page units. So nr_pages should be one
1063 * in this case.
1064 */
1065 if (PageHuge(p))
1066 nr_pages = 1 << compound_order(hpage);
1067 else /* normal page or thp */
1068 nr_pages = 1;
Naoya Horiguchi8e304562015-09-08 15:03:24 -07001069 num_poisoned_pages_add(nr_pages);
Andi Kleen6a460792009-09-16 11:50:15 +02001070
1071 /*
1072 * We need/can do nothing about count=0 pages.
1073 * 1) it's a free page, and therefore in safe hand:
1074 * prep_new_page() will be the gate keeper.
Naoya Horiguchi8c6c2ec2010-09-08 10:19:38 +09001075 * 2) it's a free hugepage, which is also safe:
1076 * an affected hugepage will be dequeued from hugepage freelist,
1077 * so there's no concern about reusing it ever after.
1078 * 3) it's part of a non-compound high order page.
Andi Kleen6a460792009-09-16 11:50:15 +02001079 * Implies some kernel user: cannot stop them from
1080 * R/W the page; let's pray that the page has been
1081 * used and will be freed some time later.
1082 * In fact it's dangerous to directly bump up page count from 0,
1083 * that may make page_freeze_refs()/page_unfreeze_refs() mismatch.
1084 */
Naoya Horiguchiead07f62015-06-24 16:56:48 -07001085 if (!(flags & MF_COUNT_INCREASED) && !get_hwpoison_page(p)) {
Wu Fengguang8d22ba12009-12-16 12:19:58 +01001086 if (is_free_buddy_page(p)) {
Xie XiuQicc637b12015-06-24 16:57:30 -07001087 action_result(pfn, MF_MSG_BUDDY, MF_DELAYED);
Wu Fengguang8d22ba12009-12-16 12:19:58 +01001088 return 0;
Naoya Horiguchi8c6c2ec2010-09-08 10:19:38 +09001089 } else if (PageHuge(hpage)) {
1090 /*
Chen Yucongb9851942014-05-22 11:54:15 -07001091 * Check "filter hit" and "race with other subpage."
Naoya Horiguchi8c6c2ec2010-09-08 10:19:38 +09001092 */
Jens Axboe7eaceac2011-03-10 08:52:07 +01001093 lock_page(hpage);
Chen Yucongb9851942014-05-22 11:54:15 -07001094 if (PageHWPoison(hpage)) {
1095 if ((hwpoison_filter(p) && TestClearPageHWPoison(p))
1096 || (p != hpage && TestSetPageHWPoison(hpage))) {
Naoya Horiguchi8e304562015-09-08 15:03:24 -07001097 num_poisoned_pages_sub(nr_pages);
Chen Yucongb9851942014-05-22 11:54:15 -07001098 unlock_page(hpage);
1099 return 0;
1100 }
Naoya Horiguchi8c6c2ec2010-09-08 10:19:38 +09001101 }
1102 set_page_hwpoison_huge_page(hpage);
1103 res = dequeue_hwpoisoned_huge_page(hpage);
Xie XiuQicc637b12015-06-24 16:57:30 -07001104 action_result(pfn, MF_MSG_FREE_HUGE,
1105 res ? MF_IGNORED : MF_DELAYED);
Naoya Horiguchi8c6c2ec2010-09-08 10:19:38 +09001106 unlock_page(hpage);
1107 return res;
Wu Fengguang8d22ba12009-12-16 12:19:58 +01001108 } else {
Xie XiuQicc637b12015-06-24 16:57:30 -07001109 action_result(pfn, MF_MSG_KERNEL_HIGH_ORDER, MF_IGNORED);
Wu Fengguang8d22ba12009-12-16 12:19:58 +01001110 return -EBUSY;
1111 }
Andi Kleen6a460792009-09-16 11:50:15 +02001112 }
1113
Naoya Horiguchi415c64c2015-06-24 16:56:45 -07001114 if (!PageHuge(p) && PageTransHuge(hpage)) {
Kirill A. Shutemov4d2fa962016-01-15 16:54:00 -08001115 lock_page(hpage);
Wanpeng Li7f6bf392015-08-14 15:35:08 -07001116 if (!PageAnon(hpage) || unlikely(split_huge_page(hpage))) {
Kirill A. Shutemov4d2fa962016-01-15 16:54:00 -08001117 unlock_page(hpage);
Wanpeng Li7f6bf392015-08-14 15:35:08 -07001118 if (!PageAnon(hpage))
Chen Yucong495367c02016-05-20 16:57:32 -07001119 pr_err("Memory failure: %#lx: non anonymous thp\n",
1120 pfn);
Wanpeng Li7f6bf392015-08-14 15:35:08 -07001121 else
Chen Yucong495367c02016-05-20 16:57:32 -07001122 pr_err("Memory failure: %#lx: thp split failed\n",
1123 pfn);
Naoya Horiguchiead07f62015-06-24 16:56:48 -07001124 if (TestClearPageHWPoison(p))
Naoya Horiguchi8e304562015-09-08 15:03:24 -07001125 num_poisoned_pages_sub(nr_pages);
Wanpeng Li665d9da2015-09-08 15:03:21 -07001126 put_hwpoison_page(p);
Naoya Horiguchi415c64c2015-06-24 16:56:45 -07001127 return -EBUSY;
1128 }
Kirill A. Shutemov4d2fa962016-01-15 16:54:00 -08001129 unlock_page(hpage);
Naoya Horiguchi4e41a302016-01-15 16:54:07 -08001130 get_hwpoison_page(p);
1131 put_hwpoison_page(hpage);
Naoya Horiguchi415c64c2015-06-24 16:56:45 -07001132 VM_BUG_ON_PAGE(!page_count(p), p);
1133 hpage = compound_head(p);
1134 }
1135
Andi Kleen6a460792009-09-16 11:50:15 +02001136 /*
Wu Fengguange43c3af2009-09-29 13:16:20 +08001137 * We ignore non-LRU pages for good reasons.
1138 * - PG_locked is only well defined for LRU pages and a few others
Kirill A. Shutemov48c935a2016-01-15 16:51:24 -08001139 * - to avoid races with __SetPageLocked()
Wu Fengguange43c3af2009-09-29 13:16:20 +08001140 * - to avoid races with __SetPageSlab*() (and more non-atomic ops)
1141 * The check (unnecessarily) ignores LRU pages being isolated and
1142 * walked by the page reclaim code, however that's not a big loss.
1143 */
Naoya Horiguchi09789e52015-05-05 16:23:35 -07001144 if (!PageHuge(p)) {
Naoya Horiguchi415c64c2015-06-24 16:56:45 -07001145 if (!PageLRU(p))
1146 shake_page(p, 0);
1147 if (!PageLRU(p)) {
Jin Dongmingaf241a02011-02-01 15:52:41 -08001148 /*
1149 * shake_page could have turned it free.
1150 */
1151 if (is_free_buddy_page(p)) {
Wanpeng Li2d421ac2013-09-30 13:45:23 -07001152 if (flags & MF_COUNT_INCREASED)
Xie XiuQicc637b12015-06-24 16:57:30 -07001153 action_result(pfn, MF_MSG_BUDDY, MF_DELAYED);
Wanpeng Li2d421ac2013-09-30 13:45:23 -07001154 else
Xie XiuQicc637b12015-06-24 16:57:30 -07001155 action_result(pfn, MF_MSG_BUDDY_2ND,
1156 MF_DELAYED);
Jin Dongmingaf241a02011-02-01 15:52:41 -08001157 return 0;
1158 }
Andi Kleen0474a602009-12-16 12:20:00 +01001159 }
Wu Fengguange43c3af2009-09-29 13:16:20 +08001160 }
Wu Fengguange43c3af2009-09-29 13:16:20 +08001161
Jens Axboe7eaceac2011-03-10 08:52:07 +01001162 lock_page(hpage);
Wu Fengguang847ce402009-12-16 12:19:58 +01001163
1164 /*
Andi Kleenf37d4292014-08-06 16:06:49 -07001165 * The page could have changed compound pages during the locking.
1166 * If this happens just bail out.
1167 */
Naoya Horiguchi415c64c2015-06-24 16:56:45 -07001168 if (PageCompound(p) && compound_head(p) != orig_head) {
Xie XiuQicc637b12015-06-24 16:57:30 -07001169 action_result(pfn, MF_MSG_DIFFERENT_COMPOUND, MF_IGNORED);
Andi Kleenf37d4292014-08-06 16:06:49 -07001170 res = -EBUSY;
1171 goto out;
1172 }
1173
1174 /*
Naoya Horiguchi524fca12013-02-22 16:35:51 -08001175 * We use page flags to determine what action should be taken, but
1176 * the flags can be modified by the error containment action. One
1177 * example is an mlocked page, where PG_mlocked is cleared by
1178 * page_remove_rmap() in try_to_unmap_one(). So to determine page status
1179 * correctly, we save a copy of the page flags at this time.
1180 */
1181 page_flags = p->flags;
1182
1183 /*
Wu Fengguang847ce402009-12-16 12:19:58 +01001184 * unpoison always clear PG_hwpoison inside page lock
1185 */
1186 if (!PageHWPoison(p)) {
Chen Yucong495367c02016-05-20 16:57:32 -07001187 pr_err("Memory failure: %#lx: just unpoisoned\n", pfn);
Naoya Horiguchi8e304562015-09-08 15:03:24 -07001188 num_poisoned_pages_sub(nr_pages);
Naoya Horiguchia09233f2015-08-06 15:46:58 -07001189 unlock_page(hpage);
Wanpeng Li665d9da2015-09-08 15:03:21 -07001190 put_hwpoison_page(hpage);
Naoya Horiguchia09233f2015-08-06 15:46:58 -07001191 return 0;
Wu Fengguang847ce402009-12-16 12:19:58 +01001192 }
Wu Fengguang7c116f22009-12-16 12:19:59 +01001193 if (hwpoison_filter(p)) {
1194 if (TestClearPageHWPoison(p))
Naoya Horiguchi8e304562015-09-08 15:03:24 -07001195 num_poisoned_pages_sub(nr_pages);
Naoya Horiguchi7af446a2010-05-28 09:29:17 +09001196 unlock_page(hpage);
Wanpeng Li665d9da2015-09-08 15:03:21 -07001197 put_hwpoison_page(hpage);
Wu Fengguang7c116f22009-12-16 12:19:59 +01001198 return 0;
1199 }
Wu Fengguang847ce402009-12-16 12:19:58 +01001200
Chen Yucong0bc1f8b2014-07-02 15:22:37 -07001201 if (!PageHuge(p) && !PageTransTail(p) && !PageLRU(p))
1202 goto identify_page_state;
1203
Naoya Horiguchi7013feb2010-05-28 09:29:18 +09001204 /*
1205 * For error on the tail page, we should set PG_hwpoison
1206 * on the head page to show that the hugepage is hwpoisoned
1207 */
Jin Dongminga6d30dd2011-02-01 15:52:40 -08001208 if (PageHuge(p) && PageTail(p) && TestSetPageHWPoison(hpage)) {
Xie XiuQicc637b12015-06-24 16:57:30 -07001209 action_result(pfn, MF_MSG_POISONED_HUGE, MF_IGNORED);
Naoya Horiguchi7013feb2010-05-28 09:29:18 +09001210 unlock_page(hpage);
Wanpeng Li665d9da2015-09-08 15:03:21 -07001211 put_hwpoison_page(hpage);
Naoya Horiguchi7013feb2010-05-28 09:29:18 +09001212 return 0;
1213 }
1214 /*
1215 * Set PG_hwpoison on all pages in an error hugepage,
1216 * because containment is done in hugepage unit for now.
1217 * Since we have done TestSetPageHWPoison() for the head page with
1218 * page lock held, we can safely set PG_hwpoison bits on tail pages.
1219 */
1220 if (PageHuge(p))
1221 set_page_hwpoison_huge_page(hpage);
1222
Naoya Horiguchi6edd6cc2014-06-04 16:10:35 -07001223 /*
1224 * It's very difficult to mess with pages currently under IO
1225 * and in many cases impossible, so we just avoid it here.
1226 */
Andi Kleen6a460792009-09-16 11:50:15 +02001227 wait_on_page_writeback(p);
1228
1229 /*
1230 * Now take care of user space mappings.
Minchan Kime64a7822011-03-22 16:32:44 -07001231 * Abort on fail: __delete_from_page_cache() assumes unmapped page.
Naoya Horiguchi54b9dd12014-01-23 15:53:14 -08001232 *
1233 * When the raw error page is thp tail page, hpage points to the raw
1234 * page after thp split.
Andi Kleen6a460792009-09-16 11:50:15 +02001235 */
Naoya Horiguchi54b9dd12014-01-23 15:53:14 -08001236 if (hwpoison_user_mappings(p, pfn, trapno, flags, &hpage)
1237 != SWAP_SUCCESS) {
Xie XiuQicc637b12015-06-24 16:57:30 -07001238 action_result(pfn, MF_MSG_UNMAP_FAILED, MF_IGNORED);
Wu Fengguang1668bfd2009-12-16 12:19:58 +01001239 res = -EBUSY;
1240 goto out;
1241 }
Andi Kleen6a460792009-09-16 11:50:15 +02001242
1243 /*
1244 * Torn down by someone else?
1245 */
Wu Fengguangdc2a1cb2009-12-16 12:19:58 +01001246 if (PageLRU(p) && !PageSwapCache(p) && p->mapping == NULL) {
Xie XiuQicc637b12015-06-24 16:57:30 -07001247 action_result(pfn, MF_MSG_TRUNCATED_LRU, MF_IGNORED);
Wu Fengguangd95ea512009-12-16 12:19:58 +01001248 res = -EBUSY;
Andi Kleen6a460792009-09-16 11:50:15 +02001249 goto out;
1250 }
1251
Chen Yucong0bc1f8b2014-07-02 15:22:37 -07001252identify_page_state:
Andi Kleen6a460792009-09-16 11:50:15 +02001253 res = -EBUSY;
Naoya Horiguchi524fca12013-02-22 16:35:51 -08001254 /*
1255 * The first check uses the current page flags which may not have any
1256 * relevant information. The second check with the saved page flagss is
1257 * carried out only if the first check can't determine the page status.
1258 */
1259 for (ps = error_states;; ps++)
1260 if ((p->flags & ps->mask) == ps->res)
Andi Kleen6a460792009-09-16 11:50:15 +02001261 break;
Wanpeng Li841fcc52013-09-11 14:22:50 -07001262
1263 page_flags |= (p->flags & (1UL << PG_dirty));
1264
Naoya Horiguchi524fca12013-02-22 16:35:51 -08001265 if (!ps->mask)
1266 for (ps = error_states;; ps++)
1267 if ((page_flags & ps->mask) == ps->res)
1268 break;
1269 res = page_action(ps, p, pfn);
Andi Kleen6a460792009-09-16 11:50:15 +02001270out:
Naoya Horiguchi7af446a2010-05-28 09:29:17 +09001271 unlock_page(hpage);
Andi Kleen6a460792009-09-16 11:50:15 +02001272 return res;
1273}
Tony Luckcd42f4a2011-12-15 10:48:12 -08001274EXPORT_SYMBOL_GPL(memory_failure);
Wu Fengguang847ce402009-12-16 12:19:58 +01001275
Huang Yingea8f5fb2011-07-13 13:14:27 +08001276#define MEMORY_FAILURE_FIFO_ORDER 4
1277#define MEMORY_FAILURE_FIFO_SIZE (1 << MEMORY_FAILURE_FIFO_ORDER)
1278
1279struct memory_failure_entry {
1280 unsigned long pfn;
1281 int trapno;
1282 int flags;
1283};
1284
1285struct memory_failure_cpu {
1286 DECLARE_KFIFO(fifo, struct memory_failure_entry,
1287 MEMORY_FAILURE_FIFO_SIZE);
1288 spinlock_t lock;
1289 struct work_struct work;
1290};
1291
1292static DEFINE_PER_CPU(struct memory_failure_cpu, memory_failure_cpu);
1293
1294/**
1295 * memory_failure_queue - Schedule handling memory failure of a page.
1296 * @pfn: Page Number of the corrupted page
1297 * @trapno: Trap number reported in the signal to user space.
1298 * @flags: Flags for memory failure handling
1299 *
1300 * This function is called by the low level hardware error handler
1301 * when it detects hardware memory corruption of a page. It schedules
1302 * the recovering of error page, including dropping pages, killing
1303 * processes etc.
1304 *
1305 * The function is primarily of use for corruptions that
1306 * happen outside the current execution context (e.g. when
1307 * detected by a background scrubber)
1308 *
1309 * Can run in IRQ context.
1310 */
1311void memory_failure_queue(unsigned long pfn, int trapno, int flags)
1312{
1313 struct memory_failure_cpu *mf_cpu;
1314 unsigned long proc_flags;
1315 struct memory_failure_entry entry = {
1316 .pfn = pfn,
1317 .trapno = trapno,
1318 .flags = flags,
1319 };
1320
1321 mf_cpu = &get_cpu_var(memory_failure_cpu);
1322 spin_lock_irqsave(&mf_cpu->lock, proc_flags);
Stefani Seibold498d3192013-11-14 14:32:17 -08001323 if (kfifo_put(&mf_cpu->fifo, entry))
Huang Yingea8f5fb2011-07-13 13:14:27 +08001324 schedule_work_on(smp_processor_id(), &mf_cpu->work);
1325 else
Joe Perches8e33a522013-07-25 11:53:25 -07001326 pr_err("Memory failure: buffer overflow when queuing memory failure at %#lx\n",
Huang Yingea8f5fb2011-07-13 13:14:27 +08001327 pfn);
1328 spin_unlock_irqrestore(&mf_cpu->lock, proc_flags);
1329 put_cpu_var(memory_failure_cpu);
1330}
1331EXPORT_SYMBOL_GPL(memory_failure_queue);
1332
1333static void memory_failure_work_func(struct work_struct *work)
1334{
1335 struct memory_failure_cpu *mf_cpu;
1336 struct memory_failure_entry entry = { 0, };
1337 unsigned long proc_flags;
1338 int gotten;
1339
Christoph Lameter7c8e0182014-06-04 16:07:56 -07001340 mf_cpu = this_cpu_ptr(&memory_failure_cpu);
Huang Yingea8f5fb2011-07-13 13:14:27 +08001341 for (;;) {
1342 spin_lock_irqsave(&mf_cpu->lock, proc_flags);
1343 gotten = kfifo_get(&mf_cpu->fifo, &entry);
1344 spin_unlock_irqrestore(&mf_cpu->lock, proc_flags);
1345 if (!gotten)
1346 break;
Naveen N. Raocf870c72013-07-10 14:57:01 +05301347 if (entry.flags & MF_SOFT_OFFLINE)
1348 soft_offline_page(pfn_to_page(entry.pfn), entry.flags);
1349 else
1350 memory_failure(entry.pfn, entry.trapno, entry.flags);
Huang Yingea8f5fb2011-07-13 13:14:27 +08001351 }
1352}
1353
1354static int __init memory_failure_init(void)
1355{
1356 struct memory_failure_cpu *mf_cpu;
1357 int cpu;
1358
1359 for_each_possible_cpu(cpu) {
1360 mf_cpu = &per_cpu(memory_failure_cpu, cpu);
1361 spin_lock_init(&mf_cpu->lock);
1362 INIT_KFIFO(mf_cpu->fifo);
1363 INIT_WORK(&mf_cpu->work, memory_failure_work_func);
1364 }
1365
1366 return 0;
1367}
1368core_initcall(memory_failure_init);
1369
Naoya Horiguchia5f65102015-11-05 18:47:26 -08001370#define unpoison_pr_info(fmt, pfn, rs) \
1371({ \
1372 if (__ratelimit(rs)) \
1373 pr_info(fmt, pfn); \
1374})
1375
Wu Fengguang847ce402009-12-16 12:19:58 +01001376/**
1377 * unpoison_memory - Unpoison a previously poisoned page
1378 * @pfn: Page number of the to be unpoisoned page
1379 *
1380 * Software-unpoison a page that has been poisoned by
1381 * memory_failure() earlier.
1382 *
1383 * This is only done on the software-level, so it only works
1384 * for linux injected failures, not real hardware failures
1385 *
1386 * Returns 0 for success, otherwise -errno.
1387 */
1388int unpoison_memory(unsigned long pfn)
1389{
1390 struct page *page;
1391 struct page *p;
1392 int freeit = 0;
Naoya Horiguchic9fbdd52010-05-28 09:29:19 +09001393 unsigned int nr_pages;
Naoya Horiguchia5f65102015-11-05 18:47:26 -08001394 static DEFINE_RATELIMIT_STATE(unpoison_rs, DEFAULT_RATELIMIT_INTERVAL,
1395 DEFAULT_RATELIMIT_BURST);
Wu Fengguang847ce402009-12-16 12:19:58 +01001396
1397 if (!pfn_valid(pfn))
1398 return -ENXIO;
1399
1400 p = pfn_to_page(pfn);
1401 page = compound_head(p);
1402
1403 if (!PageHWPoison(p)) {
Chen Yucong495367c02016-05-20 16:57:32 -07001404 unpoison_pr_info("Unpoison: Page was already unpoisoned %#lx\n",
Naoya Horiguchia5f65102015-11-05 18:47:26 -08001405 pfn, &unpoison_rs);
Wu Fengguang847ce402009-12-16 12:19:58 +01001406 return 0;
1407 }
1408
Naoya Horiguchi230ac712015-09-08 15:03:29 -07001409 if (page_count(page) > 1) {
Chen Yucong495367c02016-05-20 16:57:32 -07001410 unpoison_pr_info("Unpoison: Someone grabs the hwpoison page %#lx\n",
Naoya Horiguchia5f65102015-11-05 18:47:26 -08001411 pfn, &unpoison_rs);
Naoya Horiguchi230ac712015-09-08 15:03:29 -07001412 return 0;
1413 }
1414
1415 if (page_mapped(page)) {
Chen Yucong495367c02016-05-20 16:57:32 -07001416 unpoison_pr_info("Unpoison: Someone maps the hwpoison page %#lx\n",
Naoya Horiguchia5f65102015-11-05 18:47:26 -08001417 pfn, &unpoison_rs);
Naoya Horiguchi230ac712015-09-08 15:03:29 -07001418 return 0;
1419 }
1420
1421 if (page_mapping(page)) {
Chen Yucong495367c02016-05-20 16:57:32 -07001422 unpoison_pr_info("Unpoison: the hwpoison page has non-NULL mapping %#lx\n",
Naoya Horiguchia5f65102015-11-05 18:47:26 -08001423 pfn, &unpoison_rs);
Naoya Horiguchi230ac712015-09-08 15:03:29 -07001424 return 0;
1425 }
1426
Wanpeng Li0cea3fd2013-09-11 14:22:53 -07001427 /*
1428 * unpoison_memory() can encounter thp only when the thp is being
1429 * worked by memory_failure() and the page lock is not held yet.
1430 * In such case, we yield to memory_failure() and make unpoison fail.
1431 */
Wanpeng Lie76d30e2013-09-30 13:45:22 -07001432 if (!PageHuge(page) && PageTransHuge(page)) {
Chen Yucong495367c02016-05-20 16:57:32 -07001433 unpoison_pr_info("Unpoison: Memory failure is now running on %#lx\n",
Naoya Horiguchia5f65102015-11-05 18:47:26 -08001434 pfn, &unpoison_rs);
Naoya Horiguchiead07f62015-06-24 16:56:48 -07001435 return 0;
Wanpeng Li0cea3fd2013-09-11 14:22:53 -07001436 }
1437
Wanpeng Lif9121152013-09-11 14:22:52 -07001438 nr_pages = 1 << compound_order(page);
Naoya Horiguchic9fbdd52010-05-28 09:29:19 +09001439
Naoya Horiguchiead07f62015-06-24 16:56:48 -07001440 if (!get_hwpoison_page(p)) {
Naoya Horiguchi8c6c2ec2010-09-08 10:19:38 +09001441 /*
1442 * Since HWPoisoned hugepage should have non-zero refcount,
1443 * race between memory failure and unpoison seems to happen.
1444 * In such case unpoison fails and memory failure runs
1445 * to the end.
1446 */
1447 if (PageHuge(page)) {
Chen Yucong495367c02016-05-20 16:57:32 -07001448 unpoison_pr_info("Unpoison: Memory failure is now running on free hugepage %#lx\n",
Naoya Horiguchia5f65102015-11-05 18:47:26 -08001449 pfn, &unpoison_rs);
Naoya Horiguchi8c6c2ec2010-09-08 10:19:38 +09001450 return 0;
1451 }
Wu Fengguang847ce402009-12-16 12:19:58 +01001452 if (TestClearPageHWPoison(p))
Naoya Horiguchi8e304562015-09-08 15:03:24 -07001453 num_poisoned_pages_dec();
Chen Yucong495367c02016-05-20 16:57:32 -07001454 unpoison_pr_info("Unpoison: Software-unpoisoned free page %#lx\n",
Naoya Horiguchia5f65102015-11-05 18:47:26 -08001455 pfn, &unpoison_rs);
Wu Fengguang847ce402009-12-16 12:19:58 +01001456 return 0;
1457 }
1458
Jens Axboe7eaceac2011-03-10 08:52:07 +01001459 lock_page(page);
Wu Fengguang847ce402009-12-16 12:19:58 +01001460 /*
1461 * This test is racy because PG_hwpoison is set outside of page lock.
1462 * That's acceptable because that won't trigger kernel panic. Instead,
1463 * the PG_hwpoison page will be caught and isolated on the entrance to
1464 * the free buddy page pool.
1465 */
Naoya Horiguchic9fbdd52010-05-28 09:29:19 +09001466 if (TestClearPageHWPoison(page)) {
Chen Yucong495367c02016-05-20 16:57:32 -07001467 unpoison_pr_info("Unpoison: Software-unpoisoned page %#lx\n",
Naoya Horiguchia5f65102015-11-05 18:47:26 -08001468 pfn, &unpoison_rs);
Naoya Horiguchi8e304562015-09-08 15:03:24 -07001469 num_poisoned_pages_sub(nr_pages);
Wu Fengguang847ce402009-12-16 12:19:58 +01001470 freeit = 1;
Naoya Horiguchi6a901812010-09-08 10:19:40 +09001471 if (PageHuge(page))
1472 clear_page_hwpoison_huge_page(page);
Wu Fengguang847ce402009-12-16 12:19:58 +01001473 }
1474 unlock_page(page);
1475
Wanpeng Li665d9da2015-09-08 15:03:21 -07001476 put_hwpoison_page(page);
Wanpeng Li3ba5eeb2013-09-11 14:23:01 -07001477 if (freeit && !(pfn == my_zero_pfn(0) && page_count(p) == 1))
Wanpeng Li665d9da2015-09-08 15:03:21 -07001478 put_hwpoison_page(page);
Wu Fengguang847ce402009-12-16 12:19:58 +01001479
1480 return 0;
1481}
1482EXPORT_SYMBOL(unpoison_memory);
Andi Kleenfacb6012009-12-16 12:20:00 +01001483
1484static struct page *new_page(struct page *p, unsigned long private, int **x)
1485{
Andi Kleen12686d12009-12-16 12:20:01 +01001486 int nid = page_to_nid(p);
Naoya Horiguchid950b952010-09-08 10:19:39 +09001487 if (PageHuge(p))
1488 return alloc_huge_page_node(page_hstate(compound_head(p)),
1489 nid);
1490 else
Vlastimil Babka96db8002015-09-08 15:03:50 -07001491 return __alloc_pages_node(nid, GFP_HIGHUSER_MOVABLE, 0);
Andi Kleenfacb6012009-12-16 12:20:00 +01001492}
1493
1494/*
1495 * Safely get reference count of an arbitrary page.
1496 * Returns 0 for a free page, -EIO for a zero refcount page
1497 * that is not free, and 1 for any other page type.
1498 * For 1 the page is returned with increased page count, otherwise not.
1499 */
Naoya Horiguchiaf8fae72013-02-22 16:34:03 -08001500static int __get_any_page(struct page *p, unsigned long pfn, int flags)
Andi Kleenfacb6012009-12-16 12:20:00 +01001501{
1502 int ret;
1503
1504 if (flags & MF_COUNT_INCREASED)
1505 return 1;
1506
1507 /*
Naoya Horiguchid950b952010-09-08 10:19:39 +09001508 * When the target page is a free hugepage, just remove it
1509 * from free hugepage list.
1510 */
Naoya Horiguchiead07f62015-06-24 16:56:48 -07001511 if (!get_hwpoison_page(p)) {
Naoya Horiguchid950b952010-09-08 10:19:39 +09001512 if (PageHuge(p)) {
Borislav Petkov71dd0b82012-05-29 15:06:16 -07001513 pr_info("%s: %#lx free huge page\n", __func__, pfn);
Naoya Horiguchiaf8fae72013-02-22 16:34:03 -08001514 ret = 0;
Naoya Horiguchid950b952010-09-08 10:19:39 +09001515 } else if (is_free_buddy_page(p)) {
Borislav Petkov71dd0b82012-05-29 15:06:16 -07001516 pr_info("%s: %#lx free buddy page\n", __func__, pfn);
Andi Kleenfacb6012009-12-16 12:20:00 +01001517 ret = 0;
1518 } else {
Borislav Petkov71dd0b82012-05-29 15:06:16 -07001519 pr_info("%s: %#lx: unknown zero refcount page type %lx\n",
1520 __func__, pfn, p->flags);
Andi Kleenfacb6012009-12-16 12:20:00 +01001521 ret = -EIO;
1522 }
1523 } else {
1524 /* Not a free page */
1525 ret = 1;
1526 }
Andi Kleenfacb6012009-12-16 12:20:00 +01001527 return ret;
1528}
1529
Naoya Horiguchiaf8fae72013-02-22 16:34:03 -08001530static int get_any_page(struct page *page, unsigned long pfn, int flags)
1531{
1532 int ret = __get_any_page(page, pfn, flags);
1533
1534 if (ret == 1 && !PageHuge(page) && !PageLRU(page)) {
1535 /*
1536 * Try to free it.
1537 */
Wanpeng Li665d9da2015-09-08 15:03:21 -07001538 put_hwpoison_page(page);
Naoya Horiguchiaf8fae72013-02-22 16:34:03 -08001539 shake_page(page, 1);
1540
1541 /*
1542 * Did it turn free?
1543 */
1544 ret = __get_any_page(page, pfn, 0);
Naoya Horiguchid96b3392016-01-15 16:54:03 -08001545 if (ret == 1 && !PageLRU(page)) {
Wanpeng Li4f32be62015-08-14 15:34:56 -07001546 /* Drop page reference which is from __get_any_page() */
Wanpeng Li665d9da2015-09-08 15:03:21 -07001547 put_hwpoison_page(page);
Naoya Horiguchiaf8fae72013-02-22 16:34:03 -08001548 pr_info("soft_offline: %#lx: unknown non LRU page type %lx\n",
1549 pfn, page->flags);
1550 return -EIO;
1551 }
1552 }
1553 return ret;
1554}
1555
Naoya Horiguchid950b952010-09-08 10:19:39 +09001556static int soft_offline_huge_page(struct page *page, int flags)
1557{
1558 int ret;
1559 unsigned long pfn = page_to_pfn(page);
1560 struct page *hpage = compound_head(page);
Naoya Horiguchib8ec1ce2013-09-11 14:22:01 -07001561 LIST_HEAD(pagelist);
Naoya Horiguchid950b952010-09-08 10:19:39 +09001562
Naoya Horiguchiaf8fae72013-02-22 16:34:03 -08001563 /*
1564 * This double-check of PageHWPoison is to avoid the race with
1565 * memory_failure(). See also comment in __soft_offline_page().
1566 */
1567 lock_page(hpage);
Xishi Qiu0ebff322013-02-22 16:33:59 -08001568 if (PageHWPoison(hpage)) {
Naoya Horiguchiaf8fae72013-02-22 16:34:03 -08001569 unlock_page(hpage);
Wanpeng Li665d9da2015-09-08 15:03:21 -07001570 put_hwpoison_page(hpage);
Xishi Qiu0ebff322013-02-22 16:33:59 -08001571 pr_info("soft offline: %#lx hugepage already poisoned\n", pfn);
Naoya Horiguchiaf8fae72013-02-22 16:34:03 -08001572 return -EBUSY;
Xishi Qiu0ebff322013-02-22 16:33:59 -08001573 }
Naoya Horiguchiaf8fae72013-02-22 16:34:03 -08001574 unlock_page(hpage);
Naoya Horiguchid950b952010-09-08 10:19:39 +09001575
Naoya Horiguchibcc54222015-04-15 16:14:38 -07001576 ret = isolate_huge_page(hpage, &pagelist);
Wanpeng Li03613802015-08-14 15:34:59 -07001577 /*
1578 * get_any_page() and isolate_huge_page() takes a refcount each,
1579 * so need to drop one here.
1580 */
Wanpeng Li665d9da2015-09-08 15:03:21 -07001581 put_hwpoison_page(hpage);
Wanpeng Li03613802015-08-14 15:34:59 -07001582 if (!ret) {
Naoya Horiguchibcc54222015-04-15 16:14:38 -07001583 pr_info("soft offline: %#lx hugepage failed to isolate\n", pfn);
1584 return -EBUSY;
1585 }
1586
David Rientjes68711a72014-06-04 16:08:25 -07001587 ret = migrate_pages(&pagelist, new_page, NULL, MPOL_MF_MOVE_ALL,
Naoya Horiguchib8ec1ce2013-09-11 14:22:01 -07001588 MIGRATE_SYNC, MR_MEMORY_FAILURE);
Naoya Horiguchid950b952010-09-08 10:19:39 +09001589 if (ret) {
Dean Nelsondd73e852011-10-31 17:09:04 -07001590 pr_info("soft offline: %#lx: migration failed %d, type %lx\n",
1591 pfn, ret, page->flags);
Naoya Horiguchib8ec1ce2013-09-11 14:22:01 -07001592 /*
1593 * We know that soft_offline_huge_page() tries to migrate
1594 * only one hugepage pointed to by hpage, so we need not
1595 * run through the pagelist here.
1596 */
1597 putback_active_hugepage(hpage);
1598 if (ret > 0)
1599 ret = -EIO;
Naoya Horiguchiaf8fae72013-02-22 16:34:03 -08001600 } else {
Jianguo Wua49ecbc2013-12-18 17:08:54 -08001601 /* overcommit hugetlb page will be freed to buddy */
1602 if (PageHuge(page)) {
1603 set_page_hwpoison_huge_page(hpage);
1604 dequeue_hwpoisoned_huge_page(hpage);
Naoya Horiguchi8e304562015-09-08 15:03:24 -07001605 num_poisoned_pages_add(1 << compound_order(hpage));
Jianguo Wua49ecbc2013-12-18 17:08:54 -08001606 } else {
1607 SetPageHWPoison(page);
Naoya Horiguchi8e304562015-09-08 15:03:24 -07001608 num_poisoned_pages_inc();
Jianguo Wua49ecbc2013-12-18 17:08:54 -08001609 }
Naoya Horiguchid950b952010-09-08 10:19:39 +09001610 }
Naoya Horiguchid950b952010-09-08 10:19:39 +09001611 return ret;
1612}
1613
Naoya Horiguchiaf8fae72013-02-22 16:34:03 -08001614static int __soft_offline_page(struct page *page, int flags)
1615{
1616 int ret;
1617 unsigned long pfn = page_to_pfn(page);
Andi Kleenfacb6012009-12-16 12:20:00 +01001618
1619 /*
Naoya Horiguchiaf8fae72013-02-22 16:34:03 -08001620 * Check PageHWPoison again inside page lock because PageHWPoison
1621 * is set by memory_failure() outside page lock. Note that
1622 * memory_failure() also double-checks PageHWPoison inside page lock,
1623 * so there's no race between soft_offline_page() and memory_failure().
Andi Kleenfacb6012009-12-16 12:20:00 +01001624 */
Xishi Qiu0ebff322013-02-22 16:33:59 -08001625 lock_page(page);
1626 wait_on_page_writeback(page);
Naoya Horiguchiaf8fae72013-02-22 16:34:03 -08001627 if (PageHWPoison(page)) {
1628 unlock_page(page);
Wanpeng Li665d9da2015-09-08 15:03:21 -07001629 put_hwpoison_page(page);
Naoya Horiguchiaf8fae72013-02-22 16:34:03 -08001630 pr_info("soft offline: %#lx page already poisoned\n", pfn);
1631 return -EBUSY;
1632 }
Andi Kleenfacb6012009-12-16 12:20:00 +01001633 /*
1634 * Try to invalidate first. This should work for
1635 * non dirty unmapped page cache pages.
1636 */
1637 ret = invalidate_inode_page(page);
1638 unlock_page(page);
Andi Kleenfacb6012009-12-16 12:20:00 +01001639 /*
Andi Kleenfacb6012009-12-16 12:20:00 +01001640 * RED-PEN would be better to keep it isolated here, but we
1641 * would need to fix isolation locking first.
1642 */
Andi Kleenfacb6012009-12-16 12:20:00 +01001643 if (ret == 1) {
Wanpeng Li665d9da2015-09-08 15:03:21 -07001644 put_hwpoison_page(page);
Andi Kleenfb46e732010-09-27 23:31:30 +02001645 pr_info("soft_offline: %#lx: invalidated\n", pfn);
Naoya Horiguchiaf8fae72013-02-22 16:34:03 -08001646 SetPageHWPoison(page);
Naoya Horiguchi8e304562015-09-08 15:03:24 -07001647 num_poisoned_pages_inc();
Naoya Horiguchiaf8fae72013-02-22 16:34:03 -08001648 return 0;
Andi Kleenfacb6012009-12-16 12:20:00 +01001649 }
1650
1651 /*
1652 * Simple invalidation didn't work.
1653 * Try to migrate to a new page instead. migrate.c
1654 * handles a large number of cases for us.
1655 */
1656 ret = isolate_lru_page(page);
Konstantin Khlebnikovbd486282011-05-24 17:12:20 -07001657 /*
1658 * Drop page reference which is came from get_any_page()
1659 * successful isolate_lru_page() already took another one.
1660 */
Wanpeng Li665d9da2015-09-08 15:03:21 -07001661 put_hwpoison_page(page);
Andi Kleenfacb6012009-12-16 12:20:00 +01001662 if (!ret) {
1663 LIST_HEAD(pagelist);
Mel Gorman599d0c92016-07-28 15:45:31 -07001664 inc_node_page_state(page, NR_ISOLATED_ANON +
Hugh Dickins9c620e22013-02-22 16:35:14 -08001665 page_is_file_cache(page));
Andi Kleenfacb6012009-12-16 12:20:00 +01001666 list_add(&page->lru, &pagelist);
David Rientjes68711a72014-06-04 16:08:25 -07001667 ret = migrate_pages(&pagelist, new_page, NULL, MPOL_MF_MOVE_ALL,
Hugh Dickins9c620e22013-02-22 16:35:14 -08001668 MIGRATE_SYNC, MR_MEMORY_FAILURE);
Andi Kleenfacb6012009-12-16 12:20:00 +01001669 if (ret) {
Joonsoo Kim59c82b72014-01-21 15:51:17 -08001670 if (!list_empty(&pagelist)) {
1671 list_del(&page->lru);
Mel Gorman599d0c92016-07-28 15:45:31 -07001672 dec_node_page_state(page, NR_ISOLATED_ANON +
Joonsoo Kim59c82b72014-01-21 15:51:17 -08001673 page_is_file_cache(page));
1674 putback_lru_page(page);
1675 }
1676
Andi Kleenfb46e732010-09-27 23:31:30 +02001677 pr_info("soft offline: %#lx: migration failed %d, type %lx\n",
Andi Kleenfacb6012009-12-16 12:20:00 +01001678 pfn, ret, page->flags);
1679 if (ret > 0)
1680 ret = -EIO;
1681 }
1682 } else {
Andi Kleenfb46e732010-09-27 23:31:30 +02001683 pr_info("soft offline: %#lx: isolation failed: %d, page count %d, type %lx\n",
Dean Nelsondd73e852011-10-31 17:09:04 -07001684 pfn, ret, page_count(page), page->flags);
Andi Kleenfacb6012009-12-16 12:20:00 +01001685 }
Andi Kleenfacb6012009-12-16 12:20:00 +01001686 return ret;
1687}
Wanpeng Li86e05772013-09-11 14:22:56 -07001688
Naoya Horiguchiacc14dc2016-01-15 16:57:43 -08001689static int soft_offline_in_use_page(struct page *page, int flags)
1690{
1691 int ret;
1692 struct page *hpage = compound_head(page);
1693
1694 if (!PageHuge(page) && PageTransHuge(hpage)) {
1695 lock_page(hpage);
Naoya Horiguchi98fd1ef2016-01-15 16:57:46 -08001696 if (!PageAnon(hpage) || unlikely(split_huge_page(hpage))) {
1697 unlock_page(hpage);
1698 if (!PageAnon(hpage))
1699 pr_info("soft offline: %#lx: non anonymous thp\n", page_to_pfn(page));
1700 else
1701 pr_info("soft offline: %#lx: thp split failed\n", page_to_pfn(page));
1702 put_hwpoison_page(hpage);
Naoya Horiguchiacc14dc2016-01-15 16:57:43 -08001703 return -EBUSY;
1704 }
Naoya Horiguchi98fd1ef2016-01-15 16:57:46 -08001705 unlock_page(hpage);
Naoya Horiguchiacc14dc2016-01-15 16:57:43 -08001706 get_hwpoison_page(page);
1707 put_hwpoison_page(hpage);
1708 }
1709
1710 if (PageHuge(page))
1711 ret = soft_offline_huge_page(page, flags);
1712 else
1713 ret = __soft_offline_page(page, flags);
1714
1715 return ret;
1716}
1717
1718static void soft_offline_free_page(struct page *page)
1719{
1720 if (PageHuge(page)) {
1721 struct page *hpage = compound_head(page);
1722
1723 set_page_hwpoison_huge_page(hpage);
1724 if (!dequeue_hwpoisoned_huge_page(hpage))
1725 num_poisoned_pages_add(1 << compound_order(hpage));
1726 } else {
1727 if (!TestSetPageHWPoison(page))
1728 num_poisoned_pages_inc();
1729 }
1730}
1731
Wanpeng Li86e05772013-09-11 14:22:56 -07001732/**
1733 * soft_offline_page - Soft offline a page.
1734 * @page: page to offline
1735 * @flags: flags. Same as memory_failure().
1736 *
1737 * Returns 0 on success, otherwise negated errno.
1738 *
1739 * Soft offline a page, by migration or invalidation,
1740 * without killing anything. This is for the case when
1741 * a page is not corrupted yet (so it's still valid to access),
1742 * but has had a number of corrected errors and is better taken
1743 * out.
1744 *
1745 * The actual policy on when to do that is maintained by
1746 * user space.
1747 *
1748 * This should never impact any application or cause data loss,
1749 * however it might take some time.
1750 *
1751 * This is not a 100% solution for all memory, but tries to be
1752 * ``good enough'' for the majority of memory.
1753 */
1754int soft_offline_page(struct page *page, int flags)
1755{
1756 int ret;
1757 unsigned long pfn = page_to_pfn(page);
Wanpeng Li86e05772013-09-11 14:22:56 -07001758
1759 if (PageHWPoison(page)) {
1760 pr_info("soft offline: %#lx page already poisoned\n", pfn);
Wanpeng Li1e0e6352015-09-08 15:03:13 -07001761 if (flags & MF_COUNT_INCREASED)
Wanpeng Li665d9da2015-09-08 15:03:21 -07001762 put_hwpoison_page(page);
Wanpeng Li86e05772013-09-11 14:22:56 -07001763 return -EBUSY;
1764 }
Wanpeng Li86e05772013-09-11 14:22:56 -07001765
Vladimir Davydovbfc8c902014-06-04 16:07:18 -07001766 get_online_mems();
Wanpeng Li86e05772013-09-11 14:22:56 -07001767 ret = get_any_page(page, pfn, flags);
Vladimir Davydovbfc8c902014-06-04 16:07:18 -07001768 put_online_mems();
Naoya Horiguchi4e41a302016-01-15 16:54:07 -08001769
Naoya Horiguchiacc14dc2016-01-15 16:57:43 -08001770 if (ret > 0)
1771 ret = soft_offline_in_use_page(page, flags);
1772 else if (ret == 0)
1773 soft_offline_free_page(page);
Naoya Horiguchi4e41a302016-01-15 16:54:07 -08001774
Wanpeng Li86e05772013-09-11 14:22:56 -07001775 return ret;
1776}