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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
187 printk(KERN_ERR
Tony Luck7329bbe2011-12-13 09:27:58 -0800188 "MCE %#lx: Killing %s:%d due to hardware memory corruption\n",
Andi Kleen6a460792009-09-16 11:50:15 +0200189 pfn, t->comm, t->pid);
190 si.si_signo = SIGBUS;
191 si.si_errno = 0;
Andi Kleen6a460792009-09-16 11:50:15 +0200192 si.si_addr = (void *)addr;
193#ifdef __ARCH_SI_TRAPNO
194 si.si_trapno = trapno;
195#endif
Wanpeng Lif9121152013-09-11 14:22:52 -0700196 si.si_addr_lsb = compound_order(compound_head(page)) + PAGE_SHIFT;
Tony Luck7329bbe2011-12-13 09:27:58 -0800197
Tony Lucka70ffca2014-06-04 16:10:59 -0700198 if ((flags & MF_ACTION_REQUIRED) && t->mm == current->mm) {
Tony Luck7329bbe2011-12-13 09:27:58 -0800199 si.si_code = BUS_MCEERR_AR;
Tony Lucka70ffca2014-06-04 16:10:59 -0700200 ret = force_sig_info(SIGBUS, &si, current);
Tony Luck7329bbe2011-12-13 09:27:58 -0800201 } else {
202 /*
203 * Don't use force here, it's convenient if the signal
204 * can be temporarily blocked.
205 * This could cause a loop when the user sets SIGBUS
206 * to SIG_IGN, but hopefully no one will do that?
207 */
208 si.si_code = BUS_MCEERR_AO;
209 ret = send_sig_info(SIGBUS, &si, t); /* synchronous? */
210 }
Andi Kleen6a460792009-09-16 11:50:15 +0200211 if (ret < 0)
212 printk(KERN_INFO "MCE: Error sending signal to %s:%d: %d\n",
213 t->comm, t->pid, ret);
214 return ret;
215}
216
217/*
Andi Kleen588f9ce2009-12-16 12:19:57 +0100218 * When a unknown page type is encountered drain as many buffers as possible
219 * in the hope to turn the page into a LRU or free page, which we can handle.
220 */
Andi Kleenfacb6012009-12-16 12:20:00 +0100221void shake_page(struct page *p, int access)
Andi Kleen588f9ce2009-12-16 12:19:57 +0100222{
223 if (!PageSlab(p)) {
224 lru_add_drain_all();
225 if (PageLRU(p))
226 return;
Vlastimil Babkac0554322014-12-10 15:43:10 -0800227 drain_all_pages(page_zone(p));
Andi Kleen588f9ce2009-12-16 12:19:57 +0100228 if (PageLRU(p) || is_free_buddy_page(p))
229 return;
230 }
Andi Kleenfacb6012009-12-16 12:20:00 +0100231
Andi Kleen588f9ce2009-12-16 12:19:57 +0100232 /*
Johannes Weiner6b4f7792014-12-12 16:56:13 -0800233 * Only call shrink_node_slabs here (which would also shrink
234 * other caches) if access is not potentially fatal.
Andi Kleen588f9ce2009-12-16 12:19:57 +0100235 */
Vladimir Davydovcb731d62015-02-12 14:58:54 -0800236 if (access)
237 drop_slab_node(page_to_nid(p));
Andi Kleen588f9ce2009-12-16 12:19:57 +0100238}
239EXPORT_SYMBOL_GPL(shake_page);
240
241/*
Andi Kleen6a460792009-09-16 11:50:15 +0200242 * Kill all processes that have a poisoned page mapped and then isolate
243 * the page.
244 *
245 * General strategy:
246 * Find all processes having the page mapped and kill them.
247 * But we keep a page reference around so that the page is not
248 * actually freed yet.
249 * Then stash the page away
250 *
251 * There's no convenient way to get back to mapped processes
252 * from the VMAs. So do a brute-force search over all
253 * running processes.
254 *
255 * Remember that machine checks are not common (or rather
256 * if they are common you have other problems), so this shouldn't
257 * be a performance issue.
258 *
259 * Also there are some races possible while we get from the
260 * error detection to actually handle it.
261 */
262
263struct to_kill {
264 struct list_head nd;
265 struct task_struct *tsk;
266 unsigned long addr;
Andi Kleen9033ae12010-09-27 23:36:05 +0200267 char addr_valid;
Andi Kleen6a460792009-09-16 11:50:15 +0200268};
269
270/*
271 * Failure handling: if we can't find or can't kill a process there's
272 * not much we can do. We just print a message and ignore otherwise.
273 */
274
275/*
276 * Schedule a process for later kill.
277 * Uses GFP_ATOMIC allocations to avoid potential recursions in the VM.
278 * TBD would GFP_NOIO be enough?
279 */
280static void add_to_kill(struct task_struct *tsk, struct page *p,
281 struct vm_area_struct *vma,
282 struct list_head *to_kill,
283 struct to_kill **tkc)
284{
285 struct to_kill *tk;
286
287 if (*tkc) {
288 tk = *tkc;
289 *tkc = NULL;
290 } else {
291 tk = kmalloc(sizeof(struct to_kill), GFP_ATOMIC);
292 if (!tk) {
293 printk(KERN_ERR
294 "MCE: Out of memory while machine check handling\n");
295 return;
296 }
297 }
298 tk->addr = page_address_in_vma(p, vma);
299 tk->addr_valid = 1;
300
301 /*
302 * In theory we don't have to kill when the page was
303 * munmaped. But it could be also a mremap. Since that's
304 * likely very rare kill anyways just out of paranoia, but use
305 * a SIGKILL because the error is not contained anymore.
306 */
307 if (tk->addr == -EFAULT) {
Andi Kleenfb46e732010-09-27 23:31:30 +0200308 pr_info("MCE: Unable to find user space address %lx in %s\n",
Andi Kleen6a460792009-09-16 11:50:15 +0200309 page_to_pfn(p), tsk->comm);
310 tk->addr_valid = 0;
311 }
312 get_task_struct(tsk);
313 tk->tsk = tsk;
314 list_add_tail(&tk->nd, to_kill);
315}
316
317/*
318 * Kill the processes that have been collected earlier.
319 *
320 * Only do anything when DOIT is set, otherwise just free the list
321 * (this is used for clean pages which do not need killing)
322 * Also when FAIL is set do a force kill because something went
323 * wrong earlier.
324 */
Tony Luck6751ed62012-07-11 10:20:47 -0700325static void kill_procs(struct list_head *to_kill, int forcekill, int trapno,
Tony Luck7329bbe2011-12-13 09:27:58 -0800326 int fail, struct page *page, unsigned long pfn,
327 int flags)
Andi Kleen6a460792009-09-16 11:50:15 +0200328{
329 struct to_kill *tk, *next;
330
331 list_for_each_entry_safe (tk, next, to_kill, nd) {
Tony Luck6751ed62012-07-11 10:20:47 -0700332 if (forcekill) {
Andi Kleen6a460792009-09-16 11:50:15 +0200333 /*
André Goddard Rosaaf901ca2009-11-14 13:09:05 -0200334 * In case something went wrong with munmapping
Andi Kleen6a460792009-09-16 11:50:15 +0200335 * make sure the process doesn't catch the
336 * signal and then access the memory. Just kill it.
Andi Kleen6a460792009-09-16 11:50:15 +0200337 */
338 if (fail || tk->addr_valid == 0) {
339 printk(KERN_ERR
340 "MCE %#lx: forcibly killing %s:%d because of failure to unmap corrupted page\n",
341 pfn, tk->tsk->comm, tk->tsk->pid);
342 force_sig(SIGKILL, tk->tsk);
343 }
344
345 /*
346 * In theory the process could have mapped
347 * something else on the address in-between. We could
348 * check for that, but we need to tell the
349 * process anyways.
350 */
Tony Luck7329bbe2011-12-13 09:27:58 -0800351 else if (kill_proc(tk->tsk, tk->addr, trapno,
352 pfn, page, flags) < 0)
Andi Kleen6a460792009-09-16 11:50:15 +0200353 printk(KERN_ERR
354 "MCE %#lx: Cannot send advisory machine check signal to %s:%d\n",
355 pfn, tk->tsk->comm, tk->tsk->pid);
356 }
357 put_task_struct(tk->tsk);
358 kfree(tk);
359 }
360}
361
Naoya Horiguchi3ba08122014-06-04 16:11:02 -0700362/*
363 * Find a dedicated thread which is supposed to handle SIGBUS(BUS_MCEERR_AO)
364 * on behalf of the thread group. Return task_struct of the (first found)
365 * dedicated thread if found, and return NULL otherwise.
366 *
367 * We already hold read_lock(&tasklist_lock) in the caller, so we don't
368 * have to call rcu_read_lock/unlock() in this function.
369 */
370static struct task_struct *find_early_kill_thread(struct task_struct *tsk)
Andi Kleen6a460792009-09-16 11:50:15 +0200371{
Naoya Horiguchi3ba08122014-06-04 16:11:02 -0700372 struct task_struct *t;
373
374 for_each_thread(tsk, t)
375 if ((t->flags & PF_MCE_PROCESS) && (t->flags & PF_MCE_EARLY))
376 return t;
377 return NULL;
378}
379
380/*
381 * Determine whether a given process is "early kill" process which expects
382 * to be signaled when some page under the process is hwpoisoned.
383 * Return task_struct of the dedicated thread (main thread unless explicitly
384 * specified) if the process is "early kill," and otherwise returns NULL.
385 */
386static struct task_struct *task_early_kill(struct task_struct *tsk,
387 int force_early)
388{
389 struct task_struct *t;
Andi Kleen6a460792009-09-16 11:50:15 +0200390 if (!tsk->mm)
Naoya Horiguchi3ba08122014-06-04 16:11:02 -0700391 return NULL;
Tony Luck74614de2014-06-04 16:11:01 -0700392 if (force_early)
Naoya Horiguchi3ba08122014-06-04 16:11:02 -0700393 return tsk;
394 t = find_early_kill_thread(tsk);
395 if (t)
396 return t;
397 if (sysctl_memory_failure_early_kill)
398 return tsk;
399 return NULL;
Andi Kleen6a460792009-09-16 11:50:15 +0200400}
401
402/*
403 * Collect processes when the error hit an anonymous page.
404 */
405static void collect_procs_anon(struct page *page, struct list_head *to_kill,
Tony Luck74614de2014-06-04 16:11:01 -0700406 struct to_kill **tkc, int force_early)
Andi Kleen6a460792009-09-16 11:50:15 +0200407{
408 struct vm_area_struct *vma;
409 struct task_struct *tsk;
410 struct anon_vma *av;
Michel Lespinassebf181b92012-10-08 16:31:39 -0700411 pgoff_t pgoff;
Andi Kleen6a460792009-09-16 11:50:15 +0200412
Ingo Molnar4fc3f1d2012-12-02 19:56:50 +0000413 av = page_lock_anon_vma_read(page);
Andi Kleen6a460792009-09-16 11:50:15 +0200414 if (av == NULL) /* Not actually mapped anymore */
Peter Zijlstra9b679322011-06-27 16:18:09 -0700415 return;
416
Naoya Horiguchia0f7a752014-07-23 14:00:01 -0700417 pgoff = page_to_pgoff(page);
Peter Zijlstra9b679322011-06-27 16:18:09 -0700418 read_lock(&tasklist_lock);
Andi Kleen6a460792009-09-16 11:50:15 +0200419 for_each_process (tsk) {
Rik van Riel5beb4932010-03-05 13:42:07 -0800420 struct anon_vma_chain *vmac;
Naoya Horiguchi3ba08122014-06-04 16:11:02 -0700421 struct task_struct *t = task_early_kill(tsk, force_early);
Rik van Riel5beb4932010-03-05 13:42:07 -0800422
Naoya Horiguchi3ba08122014-06-04 16:11:02 -0700423 if (!t)
Andi Kleen6a460792009-09-16 11:50:15 +0200424 continue;
Michel Lespinassebf181b92012-10-08 16:31:39 -0700425 anon_vma_interval_tree_foreach(vmac, &av->rb_root,
426 pgoff, pgoff) {
Rik van Riel5beb4932010-03-05 13:42:07 -0800427 vma = vmac->vma;
Andi Kleen6a460792009-09-16 11:50:15 +0200428 if (!page_mapped_in_vma(page, vma))
429 continue;
Naoya Horiguchi3ba08122014-06-04 16:11:02 -0700430 if (vma->vm_mm == t->mm)
431 add_to_kill(t, page, vma, to_kill, tkc);
Andi Kleen6a460792009-09-16 11:50:15 +0200432 }
433 }
Andi Kleen6a460792009-09-16 11:50:15 +0200434 read_unlock(&tasklist_lock);
Ingo Molnar4fc3f1d2012-12-02 19:56:50 +0000435 page_unlock_anon_vma_read(av);
Andi Kleen6a460792009-09-16 11:50:15 +0200436}
437
438/*
439 * Collect processes when the error hit a file mapped page.
440 */
441static void collect_procs_file(struct page *page, struct list_head *to_kill,
Tony Luck74614de2014-06-04 16:11:01 -0700442 struct to_kill **tkc, int force_early)
Andi Kleen6a460792009-09-16 11:50:15 +0200443{
444 struct vm_area_struct *vma;
445 struct task_struct *tsk;
Andi Kleen6a460792009-09-16 11:50:15 +0200446 struct address_space *mapping = page->mapping;
447
Davidlohr Buesod28eb9c2014-12-12 16:54:36 -0800448 i_mmap_lock_read(mapping);
Peter Zijlstra9b679322011-06-27 16:18:09 -0700449 read_lock(&tasklist_lock);
Andi Kleen6a460792009-09-16 11:50:15 +0200450 for_each_process(tsk) {
Naoya Horiguchia0f7a752014-07-23 14:00:01 -0700451 pgoff_t pgoff = page_to_pgoff(page);
Naoya Horiguchi3ba08122014-06-04 16:11:02 -0700452 struct task_struct *t = task_early_kill(tsk, force_early);
Andi Kleen6a460792009-09-16 11:50:15 +0200453
Naoya Horiguchi3ba08122014-06-04 16:11:02 -0700454 if (!t)
Andi Kleen6a460792009-09-16 11:50:15 +0200455 continue;
Michel Lespinasse6b2dbba2012-10-08 16:31:25 -0700456 vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff,
Andi Kleen6a460792009-09-16 11:50:15 +0200457 pgoff) {
458 /*
459 * Send early kill signal to tasks where a vma covers
460 * the page but the corrupted page is not necessarily
461 * mapped it in its pte.
462 * Assume applications who requested early kill want
463 * to be informed of all such data corruptions.
464 */
Naoya Horiguchi3ba08122014-06-04 16:11:02 -0700465 if (vma->vm_mm == t->mm)
466 add_to_kill(t, page, vma, to_kill, tkc);
Andi Kleen6a460792009-09-16 11:50:15 +0200467 }
468 }
Andi Kleen6a460792009-09-16 11:50:15 +0200469 read_unlock(&tasklist_lock);
Davidlohr Buesod28eb9c2014-12-12 16:54:36 -0800470 i_mmap_unlock_read(mapping);
Andi Kleen6a460792009-09-16 11:50:15 +0200471}
472
473/*
474 * Collect the processes who have the corrupted page mapped to kill.
475 * This is done in two steps for locking reasons.
476 * First preallocate one tokill structure outside the spin locks,
477 * so that we can kill at least one process reasonably reliable.
478 */
Tony Luck74614de2014-06-04 16:11:01 -0700479static void collect_procs(struct page *page, struct list_head *tokill,
480 int force_early)
Andi Kleen6a460792009-09-16 11:50:15 +0200481{
482 struct to_kill *tk;
483
484 if (!page->mapping)
485 return;
486
487 tk = kmalloc(sizeof(struct to_kill), GFP_NOIO);
488 if (!tk)
489 return;
490 if (PageAnon(page))
Tony Luck74614de2014-06-04 16:11:01 -0700491 collect_procs_anon(page, tokill, &tk, force_early);
Andi Kleen6a460792009-09-16 11:50:15 +0200492 else
Tony Luck74614de2014-06-04 16:11:01 -0700493 collect_procs_file(page, tokill, &tk, force_early);
Andi Kleen6a460792009-09-16 11:50:15 +0200494 kfree(tk);
495}
496
Andi Kleen6a460792009-09-16 11:50:15 +0200497static const char *action_name[] = {
Xie XiuQicc637b12015-06-24 16:57:30 -0700498 [MF_IGNORED] = "Ignored",
499 [MF_FAILED] = "Failed",
500 [MF_DELAYED] = "Delayed",
501 [MF_RECOVERED] = "Recovered",
Naoya Horiguchi64d37a22015-04-15 16:13:05 -0700502};
503
504static const char * const action_page_types[] = {
Xie XiuQicc637b12015-06-24 16:57:30 -0700505 [MF_MSG_KERNEL] = "reserved kernel page",
506 [MF_MSG_KERNEL_HIGH_ORDER] = "high-order kernel page",
507 [MF_MSG_SLAB] = "kernel slab page",
508 [MF_MSG_DIFFERENT_COMPOUND] = "different compound page after locking",
509 [MF_MSG_POISONED_HUGE] = "huge page already hardware poisoned",
510 [MF_MSG_HUGE] = "huge page",
511 [MF_MSG_FREE_HUGE] = "free huge page",
512 [MF_MSG_UNMAP_FAILED] = "unmapping failed page",
513 [MF_MSG_DIRTY_SWAPCACHE] = "dirty swapcache page",
514 [MF_MSG_CLEAN_SWAPCACHE] = "clean swapcache page",
515 [MF_MSG_DIRTY_MLOCKED_LRU] = "dirty mlocked LRU page",
516 [MF_MSG_CLEAN_MLOCKED_LRU] = "clean mlocked LRU page",
517 [MF_MSG_DIRTY_UNEVICTABLE_LRU] = "dirty unevictable LRU page",
518 [MF_MSG_CLEAN_UNEVICTABLE_LRU] = "clean unevictable LRU page",
519 [MF_MSG_DIRTY_LRU] = "dirty LRU page",
520 [MF_MSG_CLEAN_LRU] = "clean LRU page",
521 [MF_MSG_TRUNCATED_LRU] = "already truncated LRU page",
522 [MF_MSG_BUDDY] = "free buddy page",
523 [MF_MSG_BUDDY_2ND] = "free buddy page (2nd try)",
524 [MF_MSG_UNKNOWN] = "unknown page",
Naoya Horiguchi64d37a22015-04-15 16:13:05 -0700525};
526
Andi Kleen6a460792009-09-16 11:50:15 +0200527/*
Wu Fengguangdc2a1cb2009-12-16 12:19:58 +0100528 * XXX: It is possible that a page is isolated from LRU cache,
529 * and then kept in swap cache or failed to remove from page cache.
530 * The page count will stop it from being freed by unpoison.
531 * Stress tests should be aware of this memory leak problem.
532 */
533static int delete_from_lru_cache(struct page *p)
534{
535 if (!isolate_lru_page(p)) {
536 /*
537 * Clear sensible page flags, so that the buddy system won't
538 * complain when the page is unpoison-and-freed.
539 */
540 ClearPageActive(p);
541 ClearPageUnevictable(p);
542 /*
543 * drop the page count elevated by isolate_lru_page()
544 */
545 page_cache_release(p);
546 return 0;
547 }
548 return -EIO;
549}
550
551/*
Andi Kleen6a460792009-09-16 11:50:15 +0200552 * Error hit kernel page.
553 * Do nothing, try to be lucky and not touch this instead. For a few cases we
554 * could be more sophisticated.
555 */
556static int me_kernel(struct page *p, unsigned long pfn)
557{
Xie XiuQicc637b12015-06-24 16:57:30 -0700558 return MF_IGNORED;
Andi Kleen6a460792009-09-16 11:50:15 +0200559}
560
561/*
562 * Page in unknown state. Do nothing.
563 */
564static int me_unknown(struct page *p, unsigned long pfn)
565{
566 printk(KERN_ERR "MCE %#lx: Unknown page state\n", pfn);
Xie XiuQicc637b12015-06-24 16:57:30 -0700567 return MF_FAILED;
Andi Kleen6a460792009-09-16 11:50:15 +0200568}
569
570/*
Andi Kleen6a460792009-09-16 11:50:15 +0200571 * Clean (or cleaned) page cache page.
572 */
573static int me_pagecache_clean(struct page *p, unsigned long pfn)
574{
575 int err;
Xie XiuQicc637b12015-06-24 16:57:30 -0700576 int ret = MF_FAILED;
Andi Kleen6a460792009-09-16 11:50:15 +0200577 struct address_space *mapping;
578
Wu Fengguangdc2a1cb2009-12-16 12:19:58 +0100579 delete_from_lru_cache(p);
580
Andi Kleen6a460792009-09-16 11:50:15 +0200581 /*
582 * For anonymous pages we're done the only reference left
583 * should be the one m_f() holds.
584 */
585 if (PageAnon(p))
Xie XiuQicc637b12015-06-24 16:57:30 -0700586 return MF_RECOVERED;
Andi Kleen6a460792009-09-16 11:50:15 +0200587
588 /*
589 * Now truncate the page in the page cache. This is really
590 * more like a "temporary hole punch"
591 * Don't do this for block devices when someone else
592 * has a reference, because it could be file system metadata
593 * and that's not safe to truncate.
594 */
595 mapping = page_mapping(p);
596 if (!mapping) {
597 /*
598 * Page has been teared down in the meanwhile
599 */
Xie XiuQicc637b12015-06-24 16:57:30 -0700600 return MF_FAILED;
Andi Kleen6a460792009-09-16 11:50:15 +0200601 }
602
603 /*
604 * Truncation is a bit tricky. Enable it per file system for now.
605 *
606 * Open: to take i_mutex or not for this? Right now we don't.
607 */
608 if (mapping->a_ops->error_remove_page) {
609 err = mapping->a_ops->error_remove_page(mapping, p);
610 if (err != 0) {
611 printk(KERN_INFO "MCE %#lx: Failed to punch page: %d\n",
612 pfn, err);
613 } else if (page_has_private(p) &&
614 !try_to_release_page(p, GFP_NOIO)) {
Andi Kleenfb46e732010-09-27 23:31:30 +0200615 pr_info("MCE %#lx: failed to release buffers\n", pfn);
Andi Kleen6a460792009-09-16 11:50:15 +0200616 } else {
Xie XiuQicc637b12015-06-24 16:57:30 -0700617 ret = MF_RECOVERED;
Andi Kleen6a460792009-09-16 11:50:15 +0200618 }
619 } else {
620 /*
621 * If the file system doesn't support it just invalidate
622 * This fails on dirty or anything with private pages
623 */
624 if (invalidate_inode_page(p))
Xie XiuQicc637b12015-06-24 16:57:30 -0700625 ret = MF_RECOVERED;
Andi Kleen6a460792009-09-16 11:50:15 +0200626 else
627 printk(KERN_INFO "MCE %#lx: Failed to invalidate\n",
628 pfn);
629 }
630 return ret;
631}
632
633/*
Zhi Yong Wu549543d2014-01-21 15:49:08 -0800634 * Dirty pagecache page
Andi Kleen6a460792009-09-16 11:50:15 +0200635 * Issues: when the error hit a hole page the error is not properly
636 * propagated.
637 */
638static int me_pagecache_dirty(struct page *p, unsigned long pfn)
639{
640 struct address_space *mapping = page_mapping(p);
641
642 SetPageError(p);
643 /* TBD: print more information about the file. */
644 if (mapping) {
645 /*
646 * IO error will be reported by write(), fsync(), etc.
647 * who check the mapping.
648 * This way the application knows that something went
649 * wrong with its dirty file data.
650 *
651 * There's one open issue:
652 *
653 * The EIO will be only reported on the next IO
654 * operation and then cleared through the IO map.
655 * Normally Linux has two mechanisms to pass IO error
656 * first through the AS_EIO flag in the address space
657 * and then through the PageError flag in the page.
658 * Since we drop pages on memory failure handling the
659 * only mechanism open to use is through AS_AIO.
660 *
661 * This has the disadvantage that it gets cleared on
662 * the first operation that returns an error, while
663 * the PageError bit is more sticky and only cleared
664 * when the page is reread or dropped. If an
665 * application assumes it will always get error on
666 * fsync, but does other operations on the fd before
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300667 * and the page is dropped between then the error
Andi Kleen6a460792009-09-16 11:50:15 +0200668 * will not be properly reported.
669 *
670 * This can already happen even without hwpoisoned
671 * pages: first on metadata IO errors (which only
672 * report through AS_EIO) or when the page is dropped
673 * at the wrong time.
674 *
675 * So right now we assume that the application DTRT on
676 * the first EIO, but we're not worse than other parts
677 * of the kernel.
678 */
679 mapping_set_error(mapping, EIO);
680 }
681
682 return me_pagecache_clean(p, pfn);
683}
684
685/*
686 * Clean and dirty swap cache.
687 *
688 * Dirty swap cache page is tricky to handle. The page could live both in page
689 * cache and swap cache(ie. page is freshly swapped in). So it could be
690 * referenced concurrently by 2 types of PTEs:
691 * normal PTEs and swap PTEs. We try to handle them consistently by calling
692 * try_to_unmap(TTU_IGNORE_HWPOISON) to convert the normal PTEs to swap PTEs,
693 * and then
694 * - clear dirty bit to prevent IO
695 * - remove from LRU
696 * - but keep in the swap cache, so that when we return to it on
697 * a later page fault, we know the application is accessing
698 * corrupted data and shall be killed (we installed simple
699 * interception code in do_swap_page to catch it).
700 *
701 * Clean swap cache pages can be directly isolated. A later page fault will
702 * bring in the known good data from disk.
703 */
704static int me_swapcache_dirty(struct page *p, unsigned long pfn)
705{
Andi Kleen6a460792009-09-16 11:50:15 +0200706 ClearPageDirty(p);
707 /* Trigger EIO in shmem: */
708 ClearPageUptodate(p);
709
Wu Fengguangdc2a1cb2009-12-16 12:19:58 +0100710 if (!delete_from_lru_cache(p))
Xie XiuQicc637b12015-06-24 16:57:30 -0700711 return MF_DELAYED;
Wu Fengguangdc2a1cb2009-12-16 12:19:58 +0100712 else
Xie XiuQicc637b12015-06-24 16:57:30 -0700713 return MF_FAILED;
Andi Kleen6a460792009-09-16 11:50:15 +0200714}
715
716static int me_swapcache_clean(struct page *p, unsigned long pfn)
717{
Andi Kleen6a460792009-09-16 11:50:15 +0200718 delete_from_swap_cache(p);
Wu Fengguange43c3af2009-09-29 13:16:20 +0800719
Wu Fengguangdc2a1cb2009-12-16 12:19:58 +0100720 if (!delete_from_lru_cache(p))
Xie XiuQicc637b12015-06-24 16:57:30 -0700721 return MF_RECOVERED;
Wu Fengguangdc2a1cb2009-12-16 12:19:58 +0100722 else
Xie XiuQicc637b12015-06-24 16:57:30 -0700723 return MF_FAILED;
Andi Kleen6a460792009-09-16 11:50:15 +0200724}
725
726/*
727 * Huge pages. Needs work.
728 * Issues:
Naoya Horiguchi93f70f92010-05-28 09:29:20 +0900729 * - Error on hugepage is contained in hugepage unit (not in raw page unit.)
730 * To narrow down kill region to one page, we need to break up pmd.
Andi Kleen6a460792009-09-16 11:50:15 +0200731 */
732static int me_huge_page(struct page *p, unsigned long pfn)
733{
Naoya Horiguchi6de2b1a2010-09-08 10:19:36 +0900734 int res = 0;
Naoya Horiguchi93f70f92010-05-28 09:29:20 +0900735 struct page *hpage = compound_head(p);
Naoya Horiguchi2491ffe2015-06-24 16:56:53 -0700736
737 if (!PageHuge(hpage))
738 return MF_DELAYED;
739
Naoya Horiguchi93f70f92010-05-28 09:29:20 +0900740 /*
741 * We can safely recover from error on free or reserved (i.e.
742 * not in-use) hugepage by dequeuing it from freelist.
743 * To check whether a hugepage is in-use or not, we can't use
744 * page->lru because it can be used in other hugepage operations,
745 * such as __unmap_hugepage_range() and gather_surplus_pages().
746 * So instead we use page_mapping() and PageAnon().
747 * We assume that this function is called with page lock held,
748 * so there is no race between isolation and mapping/unmapping.
749 */
750 if (!(page_mapping(hpage) || PageAnon(hpage))) {
Naoya Horiguchi6de2b1a2010-09-08 10:19:36 +0900751 res = dequeue_hwpoisoned_huge_page(hpage);
752 if (!res)
Xie XiuQicc637b12015-06-24 16:57:30 -0700753 return MF_RECOVERED;
Naoya Horiguchi93f70f92010-05-28 09:29:20 +0900754 }
Xie XiuQicc637b12015-06-24 16:57:30 -0700755 return MF_DELAYED;
Andi Kleen6a460792009-09-16 11:50:15 +0200756}
757
758/*
759 * Various page states we can handle.
760 *
761 * A page state is defined by its current page->flags bits.
762 * The table matches them in order and calls the right handler.
763 *
764 * This is quite tricky because we can access page at any time
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300765 * in its live cycle, so all accesses have to be extremely careful.
Andi Kleen6a460792009-09-16 11:50:15 +0200766 *
767 * This is not complete. More states could be added.
768 * For any missing state don't attempt recovery.
769 */
770
771#define dirty (1UL << PG_dirty)
772#define sc (1UL << PG_swapcache)
773#define unevict (1UL << PG_unevictable)
774#define mlock (1UL << PG_mlocked)
775#define writeback (1UL << PG_writeback)
776#define lru (1UL << PG_lru)
777#define swapbacked (1UL << PG_swapbacked)
778#define head (1UL << PG_head)
Andi Kleen6a460792009-09-16 11:50:15 +0200779#define slab (1UL << PG_slab)
Andi Kleen6a460792009-09-16 11:50:15 +0200780#define reserved (1UL << PG_reserved)
781
782static struct page_state {
783 unsigned long mask;
784 unsigned long res;
Xie XiuQicc637b12015-06-24 16:57:30 -0700785 enum mf_action_page_type type;
Andi Kleen6a460792009-09-16 11:50:15 +0200786 int (*action)(struct page *p, unsigned long pfn);
787} error_states[] = {
Xie XiuQicc637b12015-06-24 16:57:30 -0700788 { reserved, reserved, MF_MSG_KERNEL, me_kernel },
Wu Fengguang95d01fc2009-12-16 12:19:58 +0100789 /*
790 * free pages are specially detected outside this table:
791 * PG_buddy pages only make a small fraction of all free pages.
792 */
Andi Kleen6a460792009-09-16 11:50:15 +0200793
794 /*
795 * Could in theory check if slab page is free or if we can drop
796 * currently unused objects without touching them. But just
797 * treat it as standard kernel for now.
798 */
Xie XiuQicc637b12015-06-24 16:57:30 -0700799 { slab, slab, MF_MSG_SLAB, me_kernel },
Andi Kleen6a460792009-09-16 11:50:15 +0200800
Xie XiuQicc637b12015-06-24 16:57:30 -0700801 { head, head, MF_MSG_HUGE, me_huge_page },
Andi Kleen6a460792009-09-16 11:50:15 +0200802
Xie XiuQicc637b12015-06-24 16:57:30 -0700803 { sc|dirty, sc|dirty, MF_MSG_DIRTY_SWAPCACHE, me_swapcache_dirty },
804 { sc|dirty, sc, MF_MSG_CLEAN_SWAPCACHE, me_swapcache_clean },
Andi Kleen6a460792009-09-16 11:50:15 +0200805
Xie XiuQicc637b12015-06-24 16:57:30 -0700806 { mlock|dirty, mlock|dirty, MF_MSG_DIRTY_MLOCKED_LRU, me_pagecache_dirty },
807 { mlock|dirty, mlock, MF_MSG_CLEAN_MLOCKED_LRU, me_pagecache_clean },
Andi Kleen6a460792009-09-16 11:50:15 +0200808
Xie XiuQicc637b12015-06-24 16:57:30 -0700809 { unevict|dirty, unevict|dirty, MF_MSG_DIRTY_UNEVICTABLE_LRU, me_pagecache_dirty },
810 { unevict|dirty, unevict, MF_MSG_CLEAN_UNEVICTABLE_LRU, me_pagecache_clean },
Naoya Horiguchi5f4b9fc2013-02-22 16:35:53 -0800811
Xie XiuQicc637b12015-06-24 16:57:30 -0700812 { lru|dirty, lru|dirty, MF_MSG_DIRTY_LRU, me_pagecache_dirty },
813 { lru|dirty, lru, MF_MSG_CLEAN_LRU, me_pagecache_clean },
Andi Kleen6a460792009-09-16 11:50:15 +0200814
815 /*
816 * Catchall entry: must be at end.
817 */
Xie XiuQicc637b12015-06-24 16:57:30 -0700818 { 0, 0, MF_MSG_UNKNOWN, me_unknown },
Andi Kleen6a460792009-09-16 11:50:15 +0200819};
820
Andi Kleen2326c462009-12-16 12:20:00 +0100821#undef dirty
822#undef sc
823#undef unevict
824#undef mlock
825#undef writeback
826#undef lru
827#undef swapbacked
828#undef head
829#undef tail
830#undef compound
831#undef slab
832#undef reserved
833
Naoya Horiguchiff604cf2012-12-11 16:01:32 -0800834/*
835 * "Dirty/Clean" indication is not 100% accurate due to the possibility of
836 * setting PG_dirty outside page lock. See also comment above set_page_dirty().
837 */
Xie XiuQicc3e2af2015-06-24 16:57:33 -0700838static void action_result(unsigned long pfn, enum mf_action_page_type type,
839 enum mf_result result)
Andi Kleen6a460792009-09-16 11:50:15 +0200840{
Xie XiuQi97f0b132015-06-24 16:57:36 -0700841 trace_memory_failure_event(pfn, type, result);
842
Naoya Horiguchi64d37a22015-04-15 16:13:05 -0700843 pr_err("MCE %#lx: recovery action for %s: %s\n",
844 pfn, action_page_types[type], action_name[result]);
Andi Kleen6a460792009-09-16 11:50:15 +0200845}
846
847static int page_action(struct page_state *ps, struct page *p,
Wu Fengguangbd1ce5f2009-12-16 12:19:57 +0100848 unsigned long pfn)
Andi Kleen6a460792009-09-16 11:50:15 +0200849{
850 int result;
Wu Fengguang7456b042009-10-19 08:15:01 +0200851 int count;
Andi Kleen6a460792009-09-16 11:50:15 +0200852
853 result = ps->action(p, pfn);
Wu Fengguang7456b042009-10-19 08:15:01 +0200854
Wu Fengguangbd1ce5f2009-12-16 12:19:57 +0100855 count = page_count(p) - 1;
Xie XiuQicc637b12015-06-24 16:57:30 -0700856 if (ps->action == me_swapcache_dirty && result == MF_DELAYED)
Wu Fengguang138ce282009-12-16 12:19:58 +0100857 count--;
858 if (count != 0) {
Andi Kleen6a460792009-09-16 11:50:15 +0200859 printk(KERN_ERR
Naoya Horiguchi64d37a22015-04-15 16:13:05 -0700860 "MCE %#lx: %s still referenced by %d users\n",
861 pfn, action_page_types[ps->type], count);
Xie XiuQicc637b12015-06-24 16:57:30 -0700862 result = MF_FAILED;
Wu Fengguang138ce282009-12-16 12:19:58 +0100863 }
Naoya Horiguchi64d37a22015-04-15 16:13:05 -0700864 action_result(pfn, ps->type, result);
Andi Kleen6a460792009-09-16 11:50:15 +0200865
866 /* Could do more checks here if page looks ok */
867 /*
868 * Could adjust zone counters here to correct for the missing page.
869 */
870
Xie XiuQicc637b12015-06-24 16:57:30 -0700871 return (result == MF_RECOVERED || result == MF_DELAYED) ? 0 : -EBUSY;
Andi Kleen6a460792009-09-16 11:50:15 +0200872}
873
Naoya Horiguchiead07f62015-06-24 16:56:48 -0700874/**
875 * get_hwpoison_page() - Get refcount for memory error handling:
876 * @page: raw error page (hit by memory error)
877 *
878 * Return: return 0 if failed to grab the refcount, otherwise true (some
879 * non-zero value.)
880 */
881int get_hwpoison_page(struct page *page)
882{
883 struct page *head = compound_head(page);
884
885 if (PageHuge(head))
886 return get_page_unless_zero(head);
887
888 /*
889 * Thp tail page has special refcounting rule (refcount of tail pages
890 * is stored in ->_mapcount,) so we can't call get_page_unless_zero()
891 * directly for tail pages.
892 */
893 if (PageTransHuge(head)) {
Naoya Horiguchi98ed2b02015-08-06 15:47:04 -0700894 /*
895 * Non anonymous thp exists only in allocation/free time. We
896 * can't handle such a case correctly, so let's give it up.
897 * This should be better than triggering BUG_ON when kernel
898 * tries to touch the "partially handled" page.
899 */
900 if (!PageAnon(head)) {
901 pr_err("MCE: %#lx: non anonymous thp\n",
902 page_to_pfn(page));
903 return 0;
904 }
905
Naoya Horiguchiead07f62015-06-24 16:56:48 -0700906 if (get_page_unless_zero(head)) {
907 if (PageTail(page))
908 get_page(page);
909 return 1;
910 } else {
911 return 0;
912 }
913 }
914
915 return get_page_unless_zero(page);
916}
917EXPORT_SYMBOL_GPL(get_hwpoison_page);
918
Wanpeng Li94bf4ec2015-09-08 15:03:15 -0700919/**
920 * put_hwpoison_page() - Put refcount for memory error handling:
921 * @page: raw error page (hit by memory error)
922 */
923void put_hwpoison_page(struct page *page)
924{
925 struct page *head = compound_head(page);
926
927 if (PageHuge(head)) {
928 put_page(head);
929 return;
930 }
931
932 if (PageTransHuge(head))
933 if (page != head)
934 put_page(head);
935
936 put_page(page);
937}
938EXPORT_SYMBOL_GPL(put_hwpoison_page);
939
Andi Kleen6a460792009-09-16 11:50:15 +0200940/*
941 * Do all that is necessary to remove user space mappings. Unmap
942 * the pages and send SIGBUS to the processes if the data was dirty.
943 */
Wu Fengguang1668bfd2009-12-16 12:19:58 +0100944static int hwpoison_user_mappings(struct page *p, unsigned long pfn,
Naoya Horiguchi54b9dd12014-01-23 15:53:14 -0800945 int trapno, int flags, struct page **hpagep)
Andi Kleen6a460792009-09-16 11:50:15 +0200946{
947 enum ttu_flags ttu = TTU_UNMAP | TTU_IGNORE_MLOCK | TTU_IGNORE_ACCESS;
948 struct address_space *mapping;
949 LIST_HEAD(tokill);
950 int ret;
Tony Luck6751ed62012-07-11 10:20:47 -0700951 int kill = 1, forcekill;
Naoya Horiguchi54b9dd12014-01-23 15:53:14 -0800952 struct page *hpage = *hpagep;
Andi Kleen6a460792009-09-16 11:50:15 +0200953
Naoya Horiguchi93a9eb32014-07-30 16:08:28 -0700954 /*
955 * Here we are interested only in user-mapped pages, so skip any
956 * other types of pages.
957 */
958 if (PageReserved(p) || PageSlab(p))
959 return SWAP_SUCCESS;
960 if (!(PageLRU(hpage) || PageHuge(p)))
Wu Fengguang1668bfd2009-12-16 12:19:58 +0100961 return SWAP_SUCCESS;
Andi Kleen6a460792009-09-16 11:50:15 +0200962
Andi Kleen6a460792009-09-16 11:50:15 +0200963 /*
964 * This check implies we don't kill processes if their pages
965 * are in the swap cache early. Those are always late kills.
966 */
Naoya Horiguchi7af446a2010-05-28 09:29:17 +0900967 if (!page_mapped(hpage))
Wu Fengguang1668bfd2009-12-16 12:19:58 +0100968 return SWAP_SUCCESS;
969
Naoya Horiguchi52089b12014-07-30 16:08:30 -0700970 if (PageKsm(p)) {
971 pr_err("MCE %#lx: can't handle KSM pages.\n", pfn);
Wu Fengguang1668bfd2009-12-16 12:19:58 +0100972 return SWAP_FAIL;
Naoya Horiguchi52089b12014-07-30 16:08:30 -0700973 }
Andi Kleen6a460792009-09-16 11:50:15 +0200974
975 if (PageSwapCache(p)) {
976 printk(KERN_ERR
977 "MCE %#lx: keeping poisoned page in swap cache\n", pfn);
978 ttu |= TTU_IGNORE_HWPOISON;
979 }
980
981 /*
982 * Propagate the dirty bit from PTEs to struct page first, because we
983 * need this to decide if we should kill or just drop the page.
Wu Fengguangdb0480b2009-12-16 12:19:58 +0100984 * XXX: the dirty test could be racy: set_page_dirty() may not always
985 * be called inside page lock (it's recommended but not enforced).
Andi Kleen6a460792009-09-16 11:50:15 +0200986 */
Naoya Horiguchi7af446a2010-05-28 09:29:17 +0900987 mapping = page_mapping(hpage);
Tony Luck6751ed62012-07-11 10:20:47 -0700988 if (!(flags & MF_MUST_KILL) && !PageDirty(hpage) && mapping &&
Naoya Horiguchi7af446a2010-05-28 09:29:17 +0900989 mapping_cap_writeback_dirty(mapping)) {
990 if (page_mkclean(hpage)) {
991 SetPageDirty(hpage);
Andi Kleen6a460792009-09-16 11:50:15 +0200992 } else {
993 kill = 0;
994 ttu |= TTU_IGNORE_HWPOISON;
995 printk(KERN_INFO
996 "MCE %#lx: corrupted page was clean: dropped without side effects\n",
997 pfn);
998 }
999 }
1000
Jin Dongminga6d30dd2011-02-01 15:52:40 -08001001 /*
Andi Kleen6a460792009-09-16 11:50:15 +02001002 * First collect all the processes that have the page
1003 * mapped in dirty form. This has to be done before try_to_unmap,
1004 * because ttu takes the rmap data structures down.
1005 *
1006 * Error handling: We ignore errors here because
1007 * there's nothing that can be done.
1008 */
1009 if (kill)
Naoya Horiguchi415c64c2015-06-24 16:56:45 -07001010 collect_procs(hpage, &tokill, flags & MF_ACTION_REQUIRED);
Andi Kleen6a460792009-09-16 11:50:15 +02001011
Naoya Horiguchi415c64c2015-06-24 16:56:45 -07001012 ret = try_to_unmap(hpage, ttu);
Andi Kleen6a460792009-09-16 11:50:15 +02001013 if (ret != SWAP_SUCCESS)
1014 printk(KERN_ERR "MCE %#lx: failed to unmap page (mapcount=%d)\n",
Naoya Horiguchi415c64c2015-06-24 16:56:45 -07001015 pfn, page_mapcount(hpage));
Jin Dongminga6d30dd2011-02-01 15:52:40 -08001016
Andi Kleen6a460792009-09-16 11:50:15 +02001017 /*
1018 * Now that the dirty bit has been propagated to the
1019 * struct page and all unmaps done we can decide if
1020 * killing is needed or not. Only kill when the page
Tony Luck6751ed62012-07-11 10:20:47 -07001021 * was dirty or the process is not restartable,
1022 * otherwise the tokill list is merely
Andi Kleen6a460792009-09-16 11:50:15 +02001023 * freed. When there was a problem unmapping earlier
1024 * use a more force-full uncatchable kill to prevent
1025 * any accesses to the poisoned memory.
1026 */
Naoya Horiguchi415c64c2015-06-24 16:56:45 -07001027 forcekill = PageDirty(hpage) || (flags & MF_MUST_KILL);
Tony Luck6751ed62012-07-11 10:20:47 -07001028 kill_procs(&tokill, forcekill, trapno,
Tony Luck7329bbe2011-12-13 09:27:58 -08001029 ret != SWAP_SUCCESS, p, pfn, flags);
Wu Fengguang1668bfd2009-12-16 12:19:58 +01001030
1031 return ret;
Andi Kleen6a460792009-09-16 11:50:15 +02001032}
1033
Naoya Horiguchi7013feb2010-05-28 09:29:18 +09001034static void set_page_hwpoison_huge_page(struct page *hpage)
1035{
1036 int i;
Wanpeng Lif9121152013-09-11 14:22:52 -07001037 int nr_pages = 1 << compound_order(hpage);
Naoya Horiguchi7013feb2010-05-28 09:29:18 +09001038 for (i = 0; i < nr_pages; i++)
1039 SetPageHWPoison(hpage + i);
1040}
1041
1042static void clear_page_hwpoison_huge_page(struct page *hpage)
1043{
1044 int i;
Wanpeng Lif9121152013-09-11 14:22:52 -07001045 int nr_pages = 1 << compound_order(hpage);
Naoya Horiguchi7013feb2010-05-28 09:29:18 +09001046 for (i = 0; i < nr_pages; i++)
1047 ClearPageHWPoison(hpage + i);
1048}
1049
Tony Luckcd42f4a2011-12-15 10:48:12 -08001050/**
1051 * memory_failure - Handle memory failure of a page.
1052 * @pfn: Page Number of the corrupted page
1053 * @trapno: Trap number reported in the signal to user space.
1054 * @flags: fine tune action taken
1055 *
1056 * This function is called by the low level machine check code
1057 * of an architecture when it detects hardware memory corruption
1058 * of a page. It tries its best to recover, which includes
1059 * dropping pages, killing processes etc.
1060 *
1061 * The function is primarily of use for corruptions that
1062 * happen outside the current execution context (e.g. when
1063 * detected by a background scrubber)
1064 *
1065 * Must run in process context (e.g. a work queue) with interrupts
1066 * enabled and no spinlocks hold.
1067 */
1068int memory_failure(unsigned long pfn, int trapno, int flags)
Andi Kleen6a460792009-09-16 11:50:15 +02001069{
1070 struct page_state *ps;
1071 struct page *p;
Naoya Horiguchi7af446a2010-05-28 09:29:17 +09001072 struct page *hpage;
Naoya Horiguchi415c64c2015-06-24 16:56:45 -07001073 struct page *orig_head;
Andi Kleen6a460792009-09-16 11:50:15 +02001074 int res;
Naoya Horiguchic9fbdd52010-05-28 09:29:19 +09001075 unsigned int nr_pages;
Naoya Horiguchi524fca12013-02-22 16:35:51 -08001076 unsigned long page_flags;
Andi Kleen6a460792009-09-16 11:50:15 +02001077
1078 if (!sysctl_memory_failure_recovery)
1079 panic("Memory failure from trap %d on page %lx", trapno, pfn);
1080
1081 if (!pfn_valid(pfn)) {
Wu Fengguanga7560fc2009-12-16 12:19:57 +01001082 printk(KERN_ERR
1083 "MCE %#lx: memory outside kernel control\n",
1084 pfn);
1085 return -ENXIO;
Andi Kleen6a460792009-09-16 11:50:15 +02001086 }
1087
1088 p = pfn_to_page(pfn);
Naoya Horiguchi415c64c2015-06-24 16:56:45 -07001089 orig_head = hpage = compound_head(p);
Andi Kleen6a460792009-09-16 11:50:15 +02001090 if (TestSetPageHWPoison(p)) {
Wu Fengguangd95ea512009-12-16 12:19:58 +01001091 printk(KERN_ERR "MCE %#lx: already hardware poisoned\n", pfn);
Andi Kleen6a460792009-09-16 11:50:15 +02001092 return 0;
1093 }
1094
Naoya Horiguchi4db0e952013-02-22 16:34:05 -08001095 /*
1096 * Currently errors on hugetlbfs pages are measured in hugepage units,
1097 * so nr_pages should be 1 << compound_order. OTOH when errors are on
1098 * transparent hugepages, they are supposed to be split and error
1099 * measurement is done in normal page units. So nr_pages should be one
1100 * in this case.
1101 */
1102 if (PageHuge(p))
1103 nr_pages = 1 << compound_order(hpage);
1104 else /* normal page or thp */
1105 nr_pages = 1;
Naoya Horiguchi8e304562015-09-08 15:03:24 -07001106 num_poisoned_pages_add(nr_pages);
Andi Kleen6a460792009-09-16 11:50:15 +02001107
1108 /*
1109 * We need/can do nothing about count=0 pages.
1110 * 1) it's a free page, and therefore in safe hand:
1111 * prep_new_page() will be the gate keeper.
Naoya Horiguchi8c6c2ec2010-09-08 10:19:38 +09001112 * 2) it's a free hugepage, which is also safe:
1113 * an affected hugepage will be dequeued from hugepage freelist,
1114 * so there's no concern about reusing it ever after.
1115 * 3) it's part of a non-compound high order page.
Andi Kleen6a460792009-09-16 11:50:15 +02001116 * Implies some kernel user: cannot stop them from
1117 * R/W the page; let's pray that the page has been
1118 * used and will be freed some time later.
1119 * In fact it's dangerous to directly bump up page count from 0,
1120 * that may make page_freeze_refs()/page_unfreeze_refs() mismatch.
1121 */
Naoya Horiguchiead07f62015-06-24 16:56:48 -07001122 if (!(flags & MF_COUNT_INCREASED) && !get_hwpoison_page(p)) {
Wu Fengguang8d22ba12009-12-16 12:19:58 +01001123 if (is_free_buddy_page(p)) {
Xie XiuQicc637b12015-06-24 16:57:30 -07001124 action_result(pfn, MF_MSG_BUDDY, MF_DELAYED);
Wu Fengguang8d22ba12009-12-16 12:19:58 +01001125 return 0;
Naoya Horiguchi8c6c2ec2010-09-08 10:19:38 +09001126 } else if (PageHuge(hpage)) {
1127 /*
Chen Yucongb9851942014-05-22 11:54:15 -07001128 * Check "filter hit" and "race with other subpage."
Naoya Horiguchi8c6c2ec2010-09-08 10:19:38 +09001129 */
Jens Axboe7eaceac2011-03-10 08:52:07 +01001130 lock_page(hpage);
Chen Yucongb9851942014-05-22 11:54:15 -07001131 if (PageHWPoison(hpage)) {
1132 if ((hwpoison_filter(p) && TestClearPageHWPoison(p))
1133 || (p != hpage && TestSetPageHWPoison(hpage))) {
Naoya Horiguchi8e304562015-09-08 15:03:24 -07001134 num_poisoned_pages_sub(nr_pages);
Chen Yucongb9851942014-05-22 11:54:15 -07001135 unlock_page(hpage);
1136 return 0;
1137 }
Naoya Horiguchi8c6c2ec2010-09-08 10:19:38 +09001138 }
1139 set_page_hwpoison_huge_page(hpage);
1140 res = dequeue_hwpoisoned_huge_page(hpage);
Xie XiuQicc637b12015-06-24 16:57:30 -07001141 action_result(pfn, MF_MSG_FREE_HUGE,
1142 res ? MF_IGNORED : MF_DELAYED);
Naoya Horiguchi8c6c2ec2010-09-08 10:19:38 +09001143 unlock_page(hpage);
1144 return res;
Wu Fengguang8d22ba12009-12-16 12:19:58 +01001145 } else {
Xie XiuQicc637b12015-06-24 16:57:30 -07001146 action_result(pfn, MF_MSG_KERNEL_HIGH_ORDER, MF_IGNORED);
Wu Fengguang8d22ba12009-12-16 12:19:58 +01001147 return -EBUSY;
1148 }
Andi Kleen6a460792009-09-16 11:50:15 +02001149 }
1150
Naoya Horiguchi415c64c2015-06-24 16:56:45 -07001151 if (!PageHuge(p) && PageTransHuge(hpage)) {
Wanpeng Li7f6bf392015-08-14 15:35:08 -07001152 if (!PageAnon(hpage) || unlikely(split_huge_page(hpage))) {
1153 if (!PageAnon(hpage))
1154 pr_err("MCE: %#lx: non anonymous thp\n", pfn);
1155 else
1156 pr_err("MCE: %#lx: thp split failed\n", pfn);
Naoya Horiguchiead07f62015-06-24 16:56:48 -07001157 if (TestClearPageHWPoison(p))
Naoya Horiguchi8e304562015-09-08 15:03:24 -07001158 num_poisoned_pages_sub(nr_pages);
Wanpeng Li665d9da2015-09-08 15:03:21 -07001159 put_hwpoison_page(p);
Naoya Horiguchi415c64c2015-06-24 16:56:45 -07001160 return -EBUSY;
1161 }
1162 VM_BUG_ON_PAGE(!page_count(p), p);
1163 hpage = compound_head(p);
1164 }
1165
Andi Kleen6a460792009-09-16 11:50:15 +02001166 /*
Wu Fengguange43c3af2009-09-29 13:16:20 +08001167 * We ignore non-LRU pages for good reasons.
1168 * - PG_locked is only well defined for LRU pages and a few others
1169 * - to avoid races with __set_page_locked()
1170 * - to avoid races with __SetPageSlab*() (and more non-atomic ops)
1171 * The check (unnecessarily) ignores LRU pages being isolated and
1172 * walked by the page reclaim code, however that's not a big loss.
1173 */
Naoya Horiguchi09789e52015-05-05 16:23:35 -07001174 if (!PageHuge(p)) {
Naoya Horiguchi415c64c2015-06-24 16:56:45 -07001175 if (!PageLRU(p))
1176 shake_page(p, 0);
1177 if (!PageLRU(p)) {
Jin Dongmingaf241a02011-02-01 15:52:41 -08001178 /*
1179 * shake_page could have turned it free.
1180 */
1181 if (is_free_buddy_page(p)) {
Wanpeng Li2d421ac2013-09-30 13:45:23 -07001182 if (flags & MF_COUNT_INCREASED)
Xie XiuQicc637b12015-06-24 16:57:30 -07001183 action_result(pfn, MF_MSG_BUDDY, MF_DELAYED);
Wanpeng Li2d421ac2013-09-30 13:45:23 -07001184 else
Xie XiuQicc637b12015-06-24 16:57:30 -07001185 action_result(pfn, MF_MSG_BUDDY_2ND,
1186 MF_DELAYED);
Jin Dongmingaf241a02011-02-01 15:52:41 -08001187 return 0;
1188 }
Andi Kleen0474a602009-12-16 12:20:00 +01001189 }
Wu Fengguange43c3af2009-09-29 13:16:20 +08001190 }
Wu Fengguange43c3af2009-09-29 13:16:20 +08001191
Jens Axboe7eaceac2011-03-10 08:52:07 +01001192 lock_page(hpage);
Wu Fengguang847ce402009-12-16 12:19:58 +01001193
1194 /*
Andi Kleenf37d4292014-08-06 16:06:49 -07001195 * The page could have changed compound pages during the locking.
1196 * If this happens just bail out.
1197 */
Naoya Horiguchi415c64c2015-06-24 16:56:45 -07001198 if (PageCompound(p) && compound_head(p) != orig_head) {
Xie XiuQicc637b12015-06-24 16:57:30 -07001199 action_result(pfn, MF_MSG_DIFFERENT_COMPOUND, MF_IGNORED);
Andi Kleenf37d4292014-08-06 16:06:49 -07001200 res = -EBUSY;
1201 goto out;
1202 }
1203
1204 /*
Naoya Horiguchi524fca12013-02-22 16:35:51 -08001205 * We use page flags to determine what action should be taken, but
1206 * the flags can be modified by the error containment action. One
1207 * example is an mlocked page, where PG_mlocked is cleared by
1208 * page_remove_rmap() in try_to_unmap_one(). So to determine page status
1209 * correctly, we save a copy of the page flags at this time.
1210 */
1211 page_flags = p->flags;
1212
1213 /*
Wu Fengguang847ce402009-12-16 12:19:58 +01001214 * unpoison always clear PG_hwpoison inside page lock
1215 */
1216 if (!PageHWPoison(p)) {
Wu Fengguangd95ea512009-12-16 12:19:58 +01001217 printk(KERN_ERR "MCE %#lx: just unpoisoned\n", pfn);
Naoya Horiguchi8e304562015-09-08 15:03:24 -07001218 num_poisoned_pages_sub(nr_pages);
Naoya Horiguchia09233f2015-08-06 15:46:58 -07001219 unlock_page(hpage);
Wanpeng Li665d9da2015-09-08 15:03:21 -07001220 put_hwpoison_page(hpage);
Naoya Horiguchia09233f2015-08-06 15:46:58 -07001221 return 0;
Wu Fengguang847ce402009-12-16 12:19:58 +01001222 }
Wu Fengguang7c116f22009-12-16 12:19:59 +01001223 if (hwpoison_filter(p)) {
1224 if (TestClearPageHWPoison(p))
Naoya Horiguchi8e304562015-09-08 15:03:24 -07001225 num_poisoned_pages_sub(nr_pages);
Naoya Horiguchi7af446a2010-05-28 09:29:17 +09001226 unlock_page(hpage);
Wanpeng Li665d9da2015-09-08 15:03:21 -07001227 put_hwpoison_page(hpage);
Wu Fengguang7c116f22009-12-16 12:19:59 +01001228 return 0;
1229 }
Wu Fengguang847ce402009-12-16 12:19:58 +01001230
Chen Yucong0bc1f8b2014-07-02 15:22:37 -07001231 if (!PageHuge(p) && !PageTransTail(p) && !PageLRU(p))
1232 goto identify_page_state;
1233
Naoya Horiguchi7013feb2010-05-28 09:29:18 +09001234 /*
1235 * For error on the tail page, we should set PG_hwpoison
1236 * on the head page to show that the hugepage is hwpoisoned
1237 */
Jin Dongminga6d30dd2011-02-01 15:52:40 -08001238 if (PageHuge(p) && PageTail(p) && TestSetPageHWPoison(hpage)) {
Xie XiuQicc637b12015-06-24 16:57:30 -07001239 action_result(pfn, MF_MSG_POISONED_HUGE, MF_IGNORED);
Naoya Horiguchi7013feb2010-05-28 09:29:18 +09001240 unlock_page(hpage);
Wanpeng Li665d9da2015-09-08 15:03:21 -07001241 put_hwpoison_page(hpage);
Naoya Horiguchi7013feb2010-05-28 09:29:18 +09001242 return 0;
1243 }
1244 /*
1245 * Set PG_hwpoison on all pages in an error hugepage,
1246 * because containment is done in hugepage unit for now.
1247 * Since we have done TestSetPageHWPoison() for the head page with
1248 * page lock held, we can safely set PG_hwpoison bits on tail pages.
1249 */
1250 if (PageHuge(p))
1251 set_page_hwpoison_huge_page(hpage);
1252
Naoya Horiguchi6edd6cc2014-06-04 16:10:35 -07001253 /*
1254 * It's very difficult to mess with pages currently under IO
1255 * and in many cases impossible, so we just avoid it here.
1256 */
Andi Kleen6a460792009-09-16 11:50:15 +02001257 wait_on_page_writeback(p);
1258
1259 /*
1260 * Now take care of user space mappings.
Minchan Kime64a7822011-03-22 16:32:44 -07001261 * Abort on fail: __delete_from_page_cache() assumes unmapped page.
Naoya Horiguchi54b9dd12014-01-23 15:53:14 -08001262 *
1263 * When the raw error page is thp tail page, hpage points to the raw
1264 * page after thp split.
Andi Kleen6a460792009-09-16 11:50:15 +02001265 */
Naoya Horiguchi54b9dd12014-01-23 15:53:14 -08001266 if (hwpoison_user_mappings(p, pfn, trapno, flags, &hpage)
1267 != SWAP_SUCCESS) {
Xie XiuQicc637b12015-06-24 16:57:30 -07001268 action_result(pfn, MF_MSG_UNMAP_FAILED, MF_IGNORED);
Wu Fengguang1668bfd2009-12-16 12:19:58 +01001269 res = -EBUSY;
1270 goto out;
1271 }
Andi Kleen6a460792009-09-16 11:50:15 +02001272
1273 /*
1274 * Torn down by someone else?
1275 */
Wu Fengguangdc2a1cb2009-12-16 12:19:58 +01001276 if (PageLRU(p) && !PageSwapCache(p) && p->mapping == NULL) {
Xie XiuQicc637b12015-06-24 16:57:30 -07001277 action_result(pfn, MF_MSG_TRUNCATED_LRU, MF_IGNORED);
Wu Fengguangd95ea512009-12-16 12:19:58 +01001278 res = -EBUSY;
Andi Kleen6a460792009-09-16 11:50:15 +02001279 goto out;
1280 }
1281
Chen Yucong0bc1f8b2014-07-02 15:22:37 -07001282identify_page_state:
Andi Kleen6a460792009-09-16 11:50:15 +02001283 res = -EBUSY;
Naoya Horiguchi524fca12013-02-22 16:35:51 -08001284 /*
1285 * The first check uses the current page flags which may not have any
1286 * relevant information. The second check with the saved page flagss is
1287 * carried out only if the first check can't determine the page status.
1288 */
1289 for (ps = error_states;; ps++)
1290 if ((p->flags & ps->mask) == ps->res)
Andi Kleen6a460792009-09-16 11:50:15 +02001291 break;
Wanpeng Li841fcc52013-09-11 14:22:50 -07001292
1293 page_flags |= (p->flags & (1UL << PG_dirty));
1294
Naoya Horiguchi524fca12013-02-22 16:35:51 -08001295 if (!ps->mask)
1296 for (ps = error_states;; ps++)
1297 if ((page_flags & ps->mask) == ps->res)
1298 break;
1299 res = page_action(ps, p, pfn);
Andi Kleen6a460792009-09-16 11:50:15 +02001300out:
Naoya Horiguchi7af446a2010-05-28 09:29:17 +09001301 unlock_page(hpage);
Andi Kleen6a460792009-09-16 11:50:15 +02001302 return res;
1303}
Tony Luckcd42f4a2011-12-15 10:48:12 -08001304EXPORT_SYMBOL_GPL(memory_failure);
Wu Fengguang847ce402009-12-16 12:19:58 +01001305
Huang Yingea8f5fb2011-07-13 13:14:27 +08001306#define MEMORY_FAILURE_FIFO_ORDER 4
1307#define MEMORY_FAILURE_FIFO_SIZE (1 << MEMORY_FAILURE_FIFO_ORDER)
1308
1309struct memory_failure_entry {
1310 unsigned long pfn;
1311 int trapno;
1312 int flags;
1313};
1314
1315struct memory_failure_cpu {
1316 DECLARE_KFIFO(fifo, struct memory_failure_entry,
1317 MEMORY_FAILURE_FIFO_SIZE);
1318 spinlock_t lock;
1319 struct work_struct work;
1320};
1321
1322static DEFINE_PER_CPU(struct memory_failure_cpu, memory_failure_cpu);
1323
1324/**
1325 * memory_failure_queue - Schedule handling memory failure of a page.
1326 * @pfn: Page Number of the corrupted page
1327 * @trapno: Trap number reported in the signal to user space.
1328 * @flags: Flags for memory failure handling
1329 *
1330 * This function is called by the low level hardware error handler
1331 * when it detects hardware memory corruption of a page. It schedules
1332 * the recovering of error page, including dropping pages, killing
1333 * processes etc.
1334 *
1335 * The function is primarily of use for corruptions that
1336 * happen outside the current execution context (e.g. when
1337 * detected by a background scrubber)
1338 *
1339 * Can run in IRQ context.
1340 */
1341void memory_failure_queue(unsigned long pfn, int trapno, int flags)
1342{
1343 struct memory_failure_cpu *mf_cpu;
1344 unsigned long proc_flags;
1345 struct memory_failure_entry entry = {
1346 .pfn = pfn,
1347 .trapno = trapno,
1348 .flags = flags,
1349 };
1350
1351 mf_cpu = &get_cpu_var(memory_failure_cpu);
1352 spin_lock_irqsave(&mf_cpu->lock, proc_flags);
Stefani Seibold498d3192013-11-14 14:32:17 -08001353 if (kfifo_put(&mf_cpu->fifo, entry))
Huang Yingea8f5fb2011-07-13 13:14:27 +08001354 schedule_work_on(smp_processor_id(), &mf_cpu->work);
1355 else
Joe Perches8e33a522013-07-25 11:53:25 -07001356 pr_err("Memory failure: buffer overflow when queuing memory failure at %#lx\n",
Huang Yingea8f5fb2011-07-13 13:14:27 +08001357 pfn);
1358 spin_unlock_irqrestore(&mf_cpu->lock, proc_flags);
1359 put_cpu_var(memory_failure_cpu);
1360}
1361EXPORT_SYMBOL_GPL(memory_failure_queue);
1362
1363static void memory_failure_work_func(struct work_struct *work)
1364{
1365 struct memory_failure_cpu *mf_cpu;
1366 struct memory_failure_entry entry = { 0, };
1367 unsigned long proc_flags;
1368 int gotten;
1369
Christoph Lameter7c8e0182014-06-04 16:07:56 -07001370 mf_cpu = this_cpu_ptr(&memory_failure_cpu);
Huang Yingea8f5fb2011-07-13 13:14:27 +08001371 for (;;) {
1372 spin_lock_irqsave(&mf_cpu->lock, proc_flags);
1373 gotten = kfifo_get(&mf_cpu->fifo, &entry);
1374 spin_unlock_irqrestore(&mf_cpu->lock, proc_flags);
1375 if (!gotten)
1376 break;
Naveen N. Raocf870c72013-07-10 14:57:01 +05301377 if (entry.flags & MF_SOFT_OFFLINE)
1378 soft_offline_page(pfn_to_page(entry.pfn), entry.flags);
1379 else
1380 memory_failure(entry.pfn, entry.trapno, entry.flags);
Huang Yingea8f5fb2011-07-13 13:14:27 +08001381 }
1382}
1383
1384static int __init memory_failure_init(void)
1385{
1386 struct memory_failure_cpu *mf_cpu;
1387 int cpu;
1388
1389 for_each_possible_cpu(cpu) {
1390 mf_cpu = &per_cpu(memory_failure_cpu, cpu);
1391 spin_lock_init(&mf_cpu->lock);
1392 INIT_KFIFO(mf_cpu->fifo);
1393 INIT_WORK(&mf_cpu->work, memory_failure_work_func);
1394 }
1395
1396 return 0;
1397}
1398core_initcall(memory_failure_init);
1399
Naoya Horiguchia5f65102015-11-05 18:47:26 -08001400#define unpoison_pr_info(fmt, pfn, rs) \
1401({ \
1402 if (__ratelimit(rs)) \
1403 pr_info(fmt, pfn); \
1404})
1405
Wu Fengguang847ce402009-12-16 12:19:58 +01001406/**
1407 * unpoison_memory - Unpoison a previously poisoned page
1408 * @pfn: Page number of the to be unpoisoned page
1409 *
1410 * Software-unpoison a page that has been poisoned by
1411 * memory_failure() earlier.
1412 *
1413 * This is only done on the software-level, so it only works
1414 * for linux injected failures, not real hardware failures
1415 *
1416 * Returns 0 for success, otherwise -errno.
1417 */
1418int unpoison_memory(unsigned long pfn)
1419{
1420 struct page *page;
1421 struct page *p;
1422 int freeit = 0;
Naoya Horiguchic9fbdd52010-05-28 09:29:19 +09001423 unsigned int nr_pages;
Naoya Horiguchia5f65102015-11-05 18:47:26 -08001424 static DEFINE_RATELIMIT_STATE(unpoison_rs, DEFAULT_RATELIMIT_INTERVAL,
1425 DEFAULT_RATELIMIT_BURST);
Wu Fengguang847ce402009-12-16 12:19:58 +01001426
1427 if (!pfn_valid(pfn))
1428 return -ENXIO;
1429
1430 p = pfn_to_page(pfn);
1431 page = compound_head(p);
1432
1433 if (!PageHWPoison(p)) {
Naoya Horiguchia5f65102015-11-05 18:47:26 -08001434 unpoison_pr_info("MCE: Page was already unpoisoned %#lx\n",
1435 pfn, &unpoison_rs);
Wu Fengguang847ce402009-12-16 12:19:58 +01001436 return 0;
1437 }
1438
Naoya Horiguchi230ac712015-09-08 15:03:29 -07001439 if (page_count(page) > 1) {
Naoya Horiguchia5f65102015-11-05 18:47:26 -08001440 unpoison_pr_info("MCE: Someone grabs the hwpoison page %#lx\n",
1441 pfn, &unpoison_rs);
Naoya Horiguchi230ac712015-09-08 15:03:29 -07001442 return 0;
1443 }
1444
1445 if (page_mapped(page)) {
Naoya Horiguchia5f65102015-11-05 18:47:26 -08001446 unpoison_pr_info("MCE: Someone maps the hwpoison page %#lx\n",
1447 pfn, &unpoison_rs);
Naoya Horiguchi230ac712015-09-08 15:03:29 -07001448 return 0;
1449 }
1450
1451 if (page_mapping(page)) {
Naoya Horiguchia5f65102015-11-05 18:47:26 -08001452 unpoison_pr_info("MCE: the hwpoison page has non-NULL mapping %#lx\n",
1453 pfn, &unpoison_rs);
Naoya Horiguchi230ac712015-09-08 15:03:29 -07001454 return 0;
1455 }
1456
Wanpeng Li0cea3fd2013-09-11 14:22:53 -07001457 /*
1458 * unpoison_memory() can encounter thp only when the thp is being
1459 * worked by memory_failure() and the page lock is not held yet.
1460 * In such case, we yield to memory_failure() and make unpoison fail.
1461 */
Wanpeng Lie76d30e2013-09-30 13:45:22 -07001462 if (!PageHuge(page) && PageTransHuge(page)) {
Naoya Horiguchia5f65102015-11-05 18:47:26 -08001463 unpoison_pr_info("MCE: Memory failure is now running on %#lx\n",
1464 pfn, &unpoison_rs);
Naoya Horiguchiead07f62015-06-24 16:56:48 -07001465 return 0;
Wanpeng Li0cea3fd2013-09-11 14:22:53 -07001466 }
1467
Wanpeng Lif9121152013-09-11 14:22:52 -07001468 nr_pages = 1 << compound_order(page);
Naoya Horiguchic9fbdd52010-05-28 09:29:19 +09001469
Naoya Horiguchiead07f62015-06-24 16:56:48 -07001470 if (!get_hwpoison_page(p)) {
Naoya Horiguchi8c6c2ec2010-09-08 10:19:38 +09001471 /*
1472 * Since HWPoisoned hugepage should have non-zero refcount,
1473 * race between memory failure and unpoison seems to happen.
1474 * In such case unpoison fails and memory failure runs
1475 * to the end.
1476 */
1477 if (PageHuge(page)) {
Naoya Horiguchia5f65102015-11-05 18:47:26 -08001478 unpoison_pr_info("MCE: Memory failure is now running on free hugepage %#lx\n",
1479 pfn, &unpoison_rs);
Naoya Horiguchi8c6c2ec2010-09-08 10:19:38 +09001480 return 0;
1481 }
Wu Fengguang847ce402009-12-16 12:19:58 +01001482 if (TestClearPageHWPoison(p))
Naoya Horiguchi8e304562015-09-08 15:03:24 -07001483 num_poisoned_pages_dec();
Naoya Horiguchia5f65102015-11-05 18:47:26 -08001484 unpoison_pr_info("MCE: Software-unpoisoned free page %#lx\n",
1485 pfn, &unpoison_rs);
Wu Fengguang847ce402009-12-16 12:19:58 +01001486 return 0;
1487 }
1488
Jens Axboe7eaceac2011-03-10 08:52:07 +01001489 lock_page(page);
Wu Fengguang847ce402009-12-16 12:19:58 +01001490 /*
1491 * This test is racy because PG_hwpoison is set outside of page lock.
1492 * That's acceptable because that won't trigger kernel panic. Instead,
1493 * the PG_hwpoison page will be caught and isolated on the entrance to
1494 * the free buddy page pool.
1495 */
Naoya Horiguchic9fbdd52010-05-28 09:29:19 +09001496 if (TestClearPageHWPoison(page)) {
Naoya Horiguchia5f65102015-11-05 18:47:26 -08001497 unpoison_pr_info("MCE: Software-unpoisoned page %#lx\n",
1498 pfn, &unpoison_rs);
Naoya Horiguchi8e304562015-09-08 15:03:24 -07001499 num_poisoned_pages_sub(nr_pages);
Wu Fengguang847ce402009-12-16 12:19:58 +01001500 freeit = 1;
Naoya Horiguchi6a901812010-09-08 10:19:40 +09001501 if (PageHuge(page))
1502 clear_page_hwpoison_huge_page(page);
Wu Fengguang847ce402009-12-16 12:19:58 +01001503 }
1504 unlock_page(page);
1505
Wanpeng Li665d9da2015-09-08 15:03:21 -07001506 put_hwpoison_page(page);
Wanpeng Li3ba5eeb2013-09-11 14:23:01 -07001507 if (freeit && !(pfn == my_zero_pfn(0) && page_count(p) == 1))
Wanpeng Li665d9da2015-09-08 15:03:21 -07001508 put_hwpoison_page(page);
Wu Fengguang847ce402009-12-16 12:19:58 +01001509
1510 return 0;
1511}
1512EXPORT_SYMBOL(unpoison_memory);
Andi Kleenfacb6012009-12-16 12:20:00 +01001513
1514static struct page *new_page(struct page *p, unsigned long private, int **x)
1515{
Andi Kleen12686d12009-12-16 12:20:01 +01001516 int nid = page_to_nid(p);
Naoya Horiguchid950b952010-09-08 10:19:39 +09001517 if (PageHuge(p))
1518 return alloc_huge_page_node(page_hstate(compound_head(p)),
1519 nid);
1520 else
Vlastimil Babka96db8002015-09-08 15:03:50 -07001521 return __alloc_pages_node(nid, GFP_HIGHUSER_MOVABLE, 0);
Andi Kleenfacb6012009-12-16 12:20:00 +01001522}
1523
1524/*
1525 * Safely get reference count of an arbitrary page.
1526 * Returns 0 for a free page, -EIO for a zero refcount page
1527 * that is not free, and 1 for any other page type.
1528 * For 1 the page is returned with increased page count, otherwise not.
1529 */
Naoya Horiguchiaf8fae72013-02-22 16:34:03 -08001530static int __get_any_page(struct page *p, unsigned long pfn, int flags)
Andi Kleenfacb6012009-12-16 12:20:00 +01001531{
1532 int ret;
1533
1534 if (flags & MF_COUNT_INCREASED)
1535 return 1;
1536
1537 /*
Naoya Horiguchid950b952010-09-08 10:19:39 +09001538 * When the target page is a free hugepage, just remove it
1539 * from free hugepage list.
1540 */
Naoya Horiguchiead07f62015-06-24 16:56:48 -07001541 if (!get_hwpoison_page(p)) {
Naoya Horiguchid950b952010-09-08 10:19:39 +09001542 if (PageHuge(p)) {
Borislav Petkov71dd0b82012-05-29 15:06:16 -07001543 pr_info("%s: %#lx free huge page\n", __func__, pfn);
Naoya Horiguchiaf8fae72013-02-22 16:34:03 -08001544 ret = 0;
Naoya Horiguchid950b952010-09-08 10:19:39 +09001545 } else if (is_free_buddy_page(p)) {
Borislav Petkov71dd0b82012-05-29 15:06:16 -07001546 pr_info("%s: %#lx free buddy page\n", __func__, pfn);
Andi Kleenfacb6012009-12-16 12:20:00 +01001547 ret = 0;
1548 } else {
Borislav Petkov71dd0b82012-05-29 15:06:16 -07001549 pr_info("%s: %#lx: unknown zero refcount page type %lx\n",
1550 __func__, pfn, p->flags);
Andi Kleenfacb6012009-12-16 12:20:00 +01001551 ret = -EIO;
1552 }
1553 } else {
1554 /* Not a free page */
1555 ret = 1;
1556 }
Andi Kleenfacb6012009-12-16 12:20:00 +01001557 return ret;
1558}
1559
Naoya Horiguchiaf8fae72013-02-22 16:34:03 -08001560static int get_any_page(struct page *page, unsigned long pfn, int flags)
1561{
1562 int ret = __get_any_page(page, pfn, flags);
1563
1564 if (ret == 1 && !PageHuge(page) && !PageLRU(page)) {
1565 /*
1566 * Try to free it.
1567 */
Wanpeng Li665d9da2015-09-08 15:03:21 -07001568 put_hwpoison_page(page);
Naoya Horiguchiaf8fae72013-02-22 16:34:03 -08001569 shake_page(page, 1);
1570
1571 /*
1572 * Did it turn free?
1573 */
1574 ret = __get_any_page(page, pfn, 0);
1575 if (!PageLRU(page)) {
Wanpeng Li4f32be62015-08-14 15:34:56 -07001576 /* Drop page reference which is from __get_any_page() */
Wanpeng Li665d9da2015-09-08 15:03:21 -07001577 put_hwpoison_page(page);
Naoya Horiguchiaf8fae72013-02-22 16:34:03 -08001578 pr_info("soft_offline: %#lx: unknown non LRU page type %lx\n",
1579 pfn, page->flags);
1580 return -EIO;
1581 }
1582 }
1583 return ret;
1584}
1585
Naoya Horiguchid950b952010-09-08 10:19:39 +09001586static int soft_offline_huge_page(struct page *page, int flags)
1587{
1588 int ret;
1589 unsigned long pfn = page_to_pfn(page);
1590 struct page *hpage = compound_head(page);
Naoya Horiguchib8ec1ce2013-09-11 14:22:01 -07001591 LIST_HEAD(pagelist);
Naoya Horiguchid950b952010-09-08 10:19:39 +09001592
Naoya Horiguchiaf8fae72013-02-22 16:34:03 -08001593 /*
1594 * This double-check of PageHWPoison is to avoid the race with
1595 * memory_failure(). See also comment in __soft_offline_page().
1596 */
1597 lock_page(hpage);
Xishi Qiu0ebff322013-02-22 16:33:59 -08001598 if (PageHWPoison(hpage)) {
Naoya Horiguchiaf8fae72013-02-22 16:34:03 -08001599 unlock_page(hpage);
Wanpeng Li665d9da2015-09-08 15:03:21 -07001600 put_hwpoison_page(hpage);
Xishi Qiu0ebff322013-02-22 16:33:59 -08001601 pr_info("soft offline: %#lx hugepage already poisoned\n", pfn);
Naoya Horiguchiaf8fae72013-02-22 16:34:03 -08001602 return -EBUSY;
Xishi Qiu0ebff322013-02-22 16:33:59 -08001603 }
Naoya Horiguchiaf8fae72013-02-22 16:34:03 -08001604 unlock_page(hpage);
Naoya Horiguchid950b952010-09-08 10:19:39 +09001605
Naoya Horiguchibcc54222015-04-15 16:14:38 -07001606 ret = isolate_huge_page(hpage, &pagelist);
Wanpeng Li03613802015-08-14 15:34:59 -07001607 /*
1608 * get_any_page() and isolate_huge_page() takes a refcount each,
1609 * so need to drop one here.
1610 */
Wanpeng Li665d9da2015-09-08 15:03:21 -07001611 put_hwpoison_page(hpage);
Wanpeng Li03613802015-08-14 15:34:59 -07001612 if (!ret) {
Naoya Horiguchibcc54222015-04-15 16:14:38 -07001613 pr_info("soft offline: %#lx hugepage failed to isolate\n", pfn);
1614 return -EBUSY;
1615 }
1616
David Rientjes68711a72014-06-04 16:08:25 -07001617 ret = migrate_pages(&pagelist, new_page, NULL, MPOL_MF_MOVE_ALL,
Naoya Horiguchib8ec1ce2013-09-11 14:22:01 -07001618 MIGRATE_SYNC, MR_MEMORY_FAILURE);
Naoya Horiguchid950b952010-09-08 10:19:39 +09001619 if (ret) {
Dean Nelsondd73e852011-10-31 17:09:04 -07001620 pr_info("soft offline: %#lx: migration failed %d, type %lx\n",
1621 pfn, ret, page->flags);
Naoya Horiguchib8ec1ce2013-09-11 14:22:01 -07001622 /*
1623 * We know that soft_offline_huge_page() tries to migrate
1624 * only one hugepage pointed to by hpage, so we need not
1625 * run through the pagelist here.
1626 */
1627 putback_active_hugepage(hpage);
1628 if (ret > 0)
1629 ret = -EIO;
Naoya Horiguchiaf8fae72013-02-22 16:34:03 -08001630 } else {
Jianguo Wua49ecbc2013-12-18 17:08:54 -08001631 /* overcommit hugetlb page will be freed to buddy */
1632 if (PageHuge(page)) {
1633 set_page_hwpoison_huge_page(hpage);
1634 dequeue_hwpoisoned_huge_page(hpage);
Naoya Horiguchi8e304562015-09-08 15:03:24 -07001635 num_poisoned_pages_add(1 << compound_order(hpage));
Jianguo Wua49ecbc2013-12-18 17:08:54 -08001636 } else {
1637 SetPageHWPoison(page);
Naoya Horiguchi8e304562015-09-08 15:03:24 -07001638 num_poisoned_pages_inc();
Jianguo Wua49ecbc2013-12-18 17:08:54 -08001639 }
Naoya Horiguchid950b952010-09-08 10:19:39 +09001640 }
Naoya Horiguchid950b952010-09-08 10:19:39 +09001641 return ret;
1642}
1643
Naoya Horiguchiaf8fae72013-02-22 16:34:03 -08001644static int __soft_offline_page(struct page *page, int flags)
1645{
1646 int ret;
1647 unsigned long pfn = page_to_pfn(page);
Andi Kleenfacb6012009-12-16 12:20:00 +01001648
1649 /*
Naoya Horiguchiaf8fae72013-02-22 16:34:03 -08001650 * Check PageHWPoison again inside page lock because PageHWPoison
1651 * is set by memory_failure() outside page lock. Note that
1652 * memory_failure() also double-checks PageHWPoison inside page lock,
1653 * so there's no race between soft_offline_page() and memory_failure().
Andi Kleenfacb6012009-12-16 12:20:00 +01001654 */
Xishi Qiu0ebff322013-02-22 16:33:59 -08001655 lock_page(page);
1656 wait_on_page_writeback(page);
Naoya Horiguchiaf8fae72013-02-22 16:34:03 -08001657 if (PageHWPoison(page)) {
1658 unlock_page(page);
Wanpeng Li665d9da2015-09-08 15:03:21 -07001659 put_hwpoison_page(page);
Naoya Horiguchiaf8fae72013-02-22 16:34:03 -08001660 pr_info("soft offline: %#lx page already poisoned\n", pfn);
1661 return -EBUSY;
1662 }
Andi Kleenfacb6012009-12-16 12:20:00 +01001663 /*
1664 * Try to invalidate first. This should work for
1665 * non dirty unmapped page cache pages.
1666 */
1667 ret = invalidate_inode_page(page);
1668 unlock_page(page);
Andi Kleenfacb6012009-12-16 12:20:00 +01001669 /*
Andi Kleenfacb6012009-12-16 12:20:00 +01001670 * RED-PEN would be better to keep it isolated here, but we
1671 * would need to fix isolation locking first.
1672 */
Andi Kleenfacb6012009-12-16 12:20:00 +01001673 if (ret == 1) {
Wanpeng Li665d9da2015-09-08 15:03:21 -07001674 put_hwpoison_page(page);
Andi Kleenfb46e732010-09-27 23:31:30 +02001675 pr_info("soft_offline: %#lx: invalidated\n", pfn);
Naoya Horiguchiaf8fae72013-02-22 16:34:03 -08001676 SetPageHWPoison(page);
Naoya Horiguchi8e304562015-09-08 15:03:24 -07001677 num_poisoned_pages_inc();
Naoya Horiguchiaf8fae72013-02-22 16:34:03 -08001678 return 0;
Andi Kleenfacb6012009-12-16 12:20:00 +01001679 }
1680
1681 /*
1682 * Simple invalidation didn't work.
1683 * Try to migrate to a new page instead. migrate.c
1684 * handles a large number of cases for us.
1685 */
1686 ret = isolate_lru_page(page);
Konstantin Khlebnikovbd486282011-05-24 17:12:20 -07001687 /*
1688 * Drop page reference which is came from get_any_page()
1689 * successful isolate_lru_page() already took another one.
1690 */
Wanpeng Li665d9da2015-09-08 15:03:21 -07001691 put_hwpoison_page(page);
Andi Kleenfacb6012009-12-16 12:20:00 +01001692 if (!ret) {
1693 LIST_HEAD(pagelist);
Minchan Kim5db8a732011-06-15 15:08:48 -07001694 inc_zone_page_state(page, NR_ISOLATED_ANON +
Hugh Dickins9c620e22013-02-22 16:35:14 -08001695 page_is_file_cache(page));
Andi Kleenfacb6012009-12-16 12:20:00 +01001696 list_add(&page->lru, &pagelist);
David Rientjes68711a72014-06-04 16:08:25 -07001697 ret = migrate_pages(&pagelist, new_page, NULL, MPOL_MF_MOVE_ALL,
Hugh Dickins9c620e22013-02-22 16:35:14 -08001698 MIGRATE_SYNC, MR_MEMORY_FAILURE);
Andi Kleenfacb6012009-12-16 12:20:00 +01001699 if (ret) {
Joonsoo Kim59c82b72014-01-21 15:51:17 -08001700 if (!list_empty(&pagelist)) {
1701 list_del(&page->lru);
1702 dec_zone_page_state(page, NR_ISOLATED_ANON +
1703 page_is_file_cache(page));
1704 putback_lru_page(page);
1705 }
1706
Andi Kleenfb46e732010-09-27 23:31:30 +02001707 pr_info("soft offline: %#lx: migration failed %d, type %lx\n",
Andi Kleenfacb6012009-12-16 12:20:00 +01001708 pfn, ret, page->flags);
1709 if (ret > 0)
1710 ret = -EIO;
1711 }
1712 } else {
Andi Kleenfb46e732010-09-27 23:31:30 +02001713 pr_info("soft offline: %#lx: isolation failed: %d, page count %d, type %lx\n",
Dean Nelsondd73e852011-10-31 17:09:04 -07001714 pfn, ret, page_count(page), page->flags);
Andi Kleenfacb6012009-12-16 12:20:00 +01001715 }
Andi Kleenfacb6012009-12-16 12:20:00 +01001716 return ret;
1717}
Wanpeng Li86e05772013-09-11 14:22:56 -07001718
1719/**
1720 * soft_offline_page - Soft offline a page.
1721 * @page: page to offline
1722 * @flags: flags. Same as memory_failure().
1723 *
1724 * Returns 0 on success, otherwise negated errno.
1725 *
1726 * Soft offline a page, by migration or invalidation,
1727 * without killing anything. This is for the case when
1728 * a page is not corrupted yet (so it's still valid to access),
1729 * but has had a number of corrected errors and is better taken
1730 * out.
1731 *
1732 * The actual policy on when to do that is maintained by
1733 * user space.
1734 *
1735 * This should never impact any application or cause data loss,
1736 * however it might take some time.
1737 *
1738 * This is not a 100% solution for all memory, but tries to be
1739 * ``good enough'' for the majority of memory.
1740 */
1741int soft_offline_page(struct page *page, int flags)
1742{
1743 int ret;
1744 unsigned long pfn = page_to_pfn(page);
David Rientjes668f9abb2014-03-03 15:38:18 -08001745 struct page *hpage = compound_head(page);
Wanpeng Li86e05772013-09-11 14:22:56 -07001746
1747 if (PageHWPoison(page)) {
1748 pr_info("soft offline: %#lx page already poisoned\n", pfn);
Wanpeng Li1e0e6352015-09-08 15:03:13 -07001749 if (flags & MF_COUNT_INCREASED)
Wanpeng Li665d9da2015-09-08 15:03:21 -07001750 put_hwpoison_page(page);
Wanpeng Li86e05772013-09-11 14:22:56 -07001751 return -EBUSY;
1752 }
1753 if (!PageHuge(page) && PageTransHuge(hpage)) {
1754 if (PageAnon(hpage) && unlikely(split_huge_page(hpage))) {
1755 pr_info("soft offline: %#lx: failed to split THP\n",
1756 pfn);
Wanpeng Li7d1900c2015-09-08 15:03:10 -07001757 if (flags & MF_COUNT_INCREASED)
Wanpeng Li665d9da2015-09-08 15:03:21 -07001758 put_hwpoison_page(page);
Wanpeng Li86e05772013-09-11 14:22:56 -07001759 return -EBUSY;
1760 }
1761 }
1762
Vladimir Davydovbfc8c902014-06-04 16:07:18 -07001763 get_online_mems();
Naoya Horiguchi03b61ff2013-11-12 15:07:26 -08001764
Wanpeng Li86e05772013-09-11 14:22:56 -07001765 ret = get_any_page(page, pfn, flags);
Vladimir Davydovbfc8c902014-06-04 16:07:18 -07001766 put_online_mems();
Naoya Horiguchi03b61ff2013-11-12 15:07:26 -08001767 if (ret > 0) { /* for in-use pages */
Wanpeng Li86e05772013-09-11 14:22:56 -07001768 if (PageHuge(page))
1769 ret = soft_offline_huge_page(page, flags);
1770 else
1771 ret = __soft_offline_page(page, flags);
Naoya Horiguchi03b61ff2013-11-12 15:07:26 -08001772 } else if (ret == 0) { /* for free pages */
Wanpeng Li86e05772013-09-11 14:22:56 -07001773 if (PageHuge(page)) {
1774 set_page_hwpoison_huge_page(hpage);
Naoya Horiguchi602498f2015-05-05 16:23:46 -07001775 if (!dequeue_hwpoisoned_huge_page(hpage))
Naoya Horiguchi8e304562015-09-08 15:03:24 -07001776 num_poisoned_pages_add(1 << compound_order(hpage));
Wanpeng Li86e05772013-09-11 14:22:56 -07001777 } else {
Naoya Horiguchi602498f2015-05-05 16:23:46 -07001778 if (!TestSetPageHWPoison(page))
Naoya Horiguchi8e304562015-09-08 15:03:24 -07001779 num_poisoned_pages_inc();
Wanpeng Li86e05772013-09-11 14:22:56 -07001780 }
1781 }
Wanpeng Li86e05772013-09-11 14:22:56 -07001782 return ret;
1783}