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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
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);
Naoya Horiguchi5a3c49b2019-02-01 14:21:08 -0800339 do_send_sig_info(SIGKILL, SEND_SIG_PRIV,
340 tk->tsk, PIDTYPE_PID);
Andi Kleen6a460792009-09-16 11:50:15 +0200341 }
342
343 /*
344 * In theory the process could have mapped
345 * something else on the address in-between. We could
346 * check for that, but we need to tell the
347 * process anyways.
348 */
Tony Luck7329bbe2011-12-13 09:27:58 -0800349 else if (kill_proc(tk->tsk, tk->addr, trapno,
350 pfn, page, flags) < 0)
Chen Yucong495367c02016-05-20 16:57:32 -0700351 pr_err("Memory failure: %#lx: Cannot send advisory machine check signal to %s:%d\n",
Joe Perches11705322016-03-17 14:19:50 -0700352 pfn, tk->tsk->comm, tk->tsk->pid);
Andi Kleen6a460792009-09-16 11:50:15 +0200353 }
354 put_task_struct(tk->tsk);
355 kfree(tk);
356 }
357}
358
Naoya Horiguchi3ba08122014-06-04 16:11:02 -0700359/*
360 * Find a dedicated thread which is supposed to handle SIGBUS(BUS_MCEERR_AO)
361 * on behalf of the thread group. Return task_struct of the (first found)
362 * dedicated thread if found, and return NULL otherwise.
363 *
364 * We already hold read_lock(&tasklist_lock) in the caller, so we don't
365 * have to call rcu_read_lock/unlock() in this function.
366 */
367static struct task_struct *find_early_kill_thread(struct task_struct *tsk)
Andi Kleen6a460792009-09-16 11:50:15 +0200368{
Naoya Horiguchi3ba08122014-06-04 16:11:02 -0700369 struct task_struct *t;
370
371 for_each_thread(tsk, t)
372 if ((t->flags & PF_MCE_PROCESS) && (t->flags & PF_MCE_EARLY))
373 return t;
374 return NULL;
375}
376
377/*
378 * Determine whether a given process is "early kill" process which expects
379 * to be signaled when some page under the process is hwpoisoned.
380 * Return task_struct of the dedicated thread (main thread unless explicitly
381 * specified) if the process is "early kill," and otherwise returns NULL.
382 */
383static struct task_struct *task_early_kill(struct task_struct *tsk,
384 int force_early)
385{
386 struct task_struct *t;
Andi Kleen6a460792009-09-16 11:50:15 +0200387 if (!tsk->mm)
Naoya Horiguchi3ba08122014-06-04 16:11:02 -0700388 return NULL;
Tony Luck74614de2014-06-04 16:11:01 -0700389 if (force_early)
Naoya Horiguchi3ba08122014-06-04 16:11:02 -0700390 return tsk;
391 t = find_early_kill_thread(tsk);
392 if (t)
393 return t;
394 if (sysctl_memory_failure_early_kill)
395 return tsk;
396 return NULL;
Andi Kleen6a460792009-09-16 11:50:15 +0200397}
398
399/*
400 * Collect processes when the error hit an anonymous page.
401 */
402static void collect_procs_anon(struct page *page, struct list_head *to_kill,
Tony Luck74614de2014-06-04 16:11:01 -0700403 struct to_kill **tkc, int force_early)
Andi Kleen6a460792009-09-16 11:50:15 +0200404{
405 struct vm_area_struct *vma;
406 struct task_struct *tsk;
407 struct anon_vma *av;
Michel Lespinassebf181b92012-10-08 16:31:39 -0700408 pgoff_t pgoff;
Andi Kleen6a460792009-09-16 11:50:15 +0200409
Ingo Molnar4fc3f1d2012-12-02 19:56:50 +0000410 av = page_lock_anon_vma_read(page);
Andi Kleen6a460792009-09-16 11:50:15 +0200411 if (av == NULL) /* Not actually mapped anymore */
Peter Zijlstra9b679322011-06-27 16:18:09 -0700412 return;
413
Naoya Horiguchia0f7a752014-07-23 14:00:01 -0700414 pgoff = page_to_pgoff(page);
Peter Zijlstra9b679322011-06-27 16:18:09 -0700415 read_lock(&tasklist_lock);
Andi Kleen6a460792009-09-16 11:50:15 +0200416 for_each_process (tsk) {
Rik van Riel5beb4932010-03-05 13:42:07 -0800417 struct anon_vma_chain *vmac;
Naoya Horiguchi3ba08122014-06-04 16:11:02 -0700418 struct task_struct *t = task_early_kill(tsk, force_early);
Rik van Riel5beb4932010-03-05 13:42:07 -0800419
Naoya Horiguchi3ba08122014-06-04 16:11:02 -0700420 if (!t)
Andi Kleen6a460792009-09-16 11:50:15 +0200421 continue;
Michel Lespinassebf181b92012-10-08 16:31:39 -0700422 anon_vma_interval_tree_foreach(vmac, &av->rb_root,
423 pgoff, pgoff) {
Rik van Riel5beb4932010-03-05 13:42:07 -0800424 vma = vmac->vma;
Andi Kleen6a460792009-09-16 11:50:15 +0200425 if (!page_mapped_in_vma(page, vma))
426 continue;
Naoya Horiguchi3ba08122014-06-04 16:11:02 -0700427 if (vma->vm_mm == t->mm)
428 add_to_kill(t, page, vma, to_kill, tkc);
Andi Kleen6a460792009-09-16 11:50:15 +0200429 }
430 }
Andi Kleen6a460792009-09-16 11:50:15 +0200431 read_unlock(&tasklist_lock);
Ingo Molnar4fc3f1d2012-12-02 19:56:50 +0000432 page_unlock_anon_vma_read(av);
Andi Kleen6a460792009-09-16 11:50:15 +0200433}
434
435/*
436 * Collect processes when the error hit a file mapped page.
437 */
438static void collect_procs_file(struct page *page, struct list_head *to_kill,
Tony Luck74614de2014-06-04 16:11:01 -0700439 struct to_kill **tkc, int force_early)
Andi Kleen6a460792009-09-16 11:50:15 +0200440{
441 struct vm_area_struct *vma;
442 struct task_struct *tsk;
Andi Kleen6a460792009-09-16 11:50:15 +0200443 struct address_space *mapping = page->mapping;
444
Davidlohr Buesod28eb9c2014-12-12 16:54:36 -0800445 i_mmap_lock_read(mapping);
Peter Zijlstra9b679322011-06-27 16:18:09 -0700446 read_lock(&tasklist_lock);
Andi Kleen6a460792009-09-16 11:50:15 +0200447 for_each_process(tsk) {
Naoya Horiguchia0f7a752014-07-23 14:00:01 -0700448 pgoff_t pgoff = page_to_pgoff(page);
Naoya Horiguchi3ba08122014-06-04 16:11:02 -0700449 struct task_struct *t = task_early_kill(tsk, force_early);
Andi Kleen6a460792009-09-16 11:50:15 +0200450
Naoya Horiguchi3ba08122014-06-04 16:11:02 -0700451 if (!t)
Andi Kleen6a460792009-09-16 11:50:15 +0200452 continue;
Michel Lespinasse6b2dbba2012-10-08 16:31:25 -0700453 vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff,
Andi Kleen6a460792009-09-16 11:50:15 +0200454 pgoff) {
455 /*
456 * Send early kill signal to tasks where a vma covers
457 * the page but the corrupted page is not necessarily
458 * mapped it in its pte.
459 * Assume applications who requested early kill want
460 * to be informed of all such data corruptions.
461 */
Naoya Horiguchi3ba08122014-06-04 16:11:02 -0700462 if (vma->vm_mm == t->mm)
463 add_to_kill(t, page, vma, to_kill, tkc);
Andi Kleen6a460792009-09-16 11:50:15 +0200464 }
465 }
Andi Kleen6a460792009-09-16 11:50:15 +0200466 read_unlock(&tasklist_lock);
Davidlohr Buesod28eb9c2014-12-12 16:54:36 -0800467 i_mmap_unlock_read(mapping);
Andi Kleen6a460792009-09-16 11:50:15 +0200468}
469
470/*
471 * Collect the processes who have the corrupted page mapped to kill.
472 * This is done in two steps for locking reasons.
473 * First preallocate one tokill structure outside the spin locks,
474 * so that we can kill at least one process reasonably reliable.
475 */
Tony Luck74614de2014-06-04 16:11:01 -0700476static void collect_procs(struct page *page, struct list_head *tokill,
477 int force_early)
Andi Kleen6a460792009-09-16 11:50:15 +0200478{
479 struct to_kill *tk;
480
481 if (!page->mapping)
482 return;
483
484 tk = kmalloc(sizeof(struct to_kill), GFP_NOIO);
485 if (!tk)
486 return;
487 if (PageAnon(page))
Tony Luck74614de2014-06-04 16:11:01 -0700488 collect_procs_anon(page, tokill, &tk, force_early);
Andi Kleen6a460792009-09-16 11:50:15 +0200489 else
Tony Luck74614de2014-06-04 16:11:01 -0700490 collect_procs_file(page, tokill, &tk, force_early);
Andi Kleen6a460792009-09-16 11:50:15 +0200491 kfree(tk);
492}
493
Andi Kleen6a460792009-09-16 11:50:15 +0200494static const char *action_name[] = {
Xie XiuQicc637b12015-06-24 16:57:30 -0700495 [MF_IGNORED] = "Ignored",
496 [MF_FAILED] = "Failed",
497 [MF_DELAYED] = "Delayed",
498 [MF_RECOVERED] = "Recovered",
Naoya Horiguchi64d37a22015-04-15 16:13:05 -0700499};
500
501static const char * const action_page_types[] = {
Xie XiuQicc637b12015-06-24 16:57:30 -0700502 [MF_MSG_KERNEL] = "reserved kernel page",
503 [MF_MSG_KERNEL_HIGH_ORDER] = "high-order kernel page",
504 [MF_MSG_SLAB] = "kernel slab page",
505 [MF_MSG_DIFFERENT_COMPOUND] = "different compound page after locking",
506 [MF_MSG_POISONED_HUGE] = "huge page already hardware poisoned",
507 [MF_MSG_HUGE] = "huge page",
508 [MF_MSG_FREE_HUGE] = "free huge page",
509 [MF_MSG_UNMAP_FAILED] = "unmapping failed page",
510 [MF_MSG_DIRTY_SWAPCACHE] = "dirty swapcache page",
511 [MF_MSG_CLEAN_SWAPCACHE] = "clean swapcache page",
512 [MF_MSG_DIRTY_MLOCKED_LRU] = "dirty mlocked LRU page",
513 [MF_MSG_CLEAN_MLOCKED_LRU] = "clean mlocked LRU page",
514 [MF_MSG_DIRTY_UNEVICTABLE_LRU] = "dirty unevictable LRU page",
515 [MF_MSG_CLEAN_UNEVICTABLE_LRU] = "clean unevictable LRU page",
516 [MF_MSG_DIRTY_LRU] = "dirty LRU page",
517 [MF_MSG_CLEAN_LRU] = "clean LRU page",
518 [MF_MSG_TRUNCATED_LRU] = "already truncated LRU page",
519 [MF_MSG_BUDDY] = "free buddy page",
520 [MF_MSG_BUDDY_2ND] = "free buddy page (2nd try)",
521 [MF_MSG_UNKNOWN] = "unknown page",
Naoya Horiguchi64d37a22015-04-15 16:13:05 -0700522};
523
Andi Kleen6a460792009-09-16 11:50:15 +0200524/*
Wu Fengguangdc2a1cb2009-12-16 12:19:58 +0100525 * XXX: It is possible that a page is isolated from LRU cache,
526 * and then kept in swap cache or failed to remove from page cache.
527 * The page count will stop it from being freed by unpoison.
528 * Stress tests should be aware of this memory leak problem.
529 */
530static int delete_from_lru_cache(struct page *p)
531{
532 if (!isolate_lru_page(p)) {
533 /*
534 * Clear sensible page flags, so that the buddy system won't
535 * complain when the page is unpoison-and-freed.
536 */
537 ClearPageActive(p);
538 ClearPageUnevictable(p);
Michal Hockobc0e2172017-05-12 15:46:26 -0700539
540 /*
541 * Poisoned page might never drop its ref count to 0 so we have
542 * to uncharge it manually from its memcg.
543 */
544 mem_cgroup_uncharge(p);
545
Wu Fengguangdc2a1cb2009-12-16 12:19:58 +0100546 /*
547 * drop the page count elevated by isolate_lru_page()
548 */
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300549 put_page(p);
Wu Fengguangdc2a1cb2009-12-16 12:19:58 +0100550 return 0;
551 }
552 return -EIO;
553}
554
555/*
Andi Kleen6a460792009-09-16 11:50:15 +0200556 * Error hit kernel page.
557 * Do nothing, try to be lucky and not touch this instead. For a few cases we
558 * could be more sophisticated.
559 */
560static int me_kernel(struct page *p, unsigned long pfn)
561{
Xie XiuQicc637b12015-06-24 16:57:30 -0700562 return MF_IGNORED;
Andi Kleen6a460792009-09-16 11:50:15 +0200563}
564
565/*
566 * Page in unknown state. Do nothing.
567 */
568static int me_unknown(struct page *p, unsigned long pfn)
569{
Chen Yucong495367c02016-05-20 16:57:32 -0700570 pr_err("Memory failure: %#lx: Unknown page state\n", pfn);
Xie XiuQicc637b12015-06-24 16:57:30 -0700571 return MF_FAILED;
Andi Kleen6a460792009-09-16 11:50:15 +0200572}
573
574/*
Andi Kleen6a460792009-09-16 11:50:15 +0200575 * Clean (or cleaned) page cache page.
576 */
577static int me_pagecache_clean(struct page *p, unsigned long pfn)
578{
579 int err;
Xie XiuQicc637b12015-06-24 16:57:30 -0700580 int ret = MF_FAILED;
Andi Kleen6a460792009-09-16 11:50:15 +0200581 struct address_space *mapping;
582
Wu Fengguangdc2a1cb2009-12-16 12:19:58 +0100583 delete_from_lru_cache(p);
584
Andi Kleen6a460792009-09-16 11:50:15 +0200585 /*
586 * For anonymous pages we're done the only reference left
587 * should be the one m_f() holds.
588 */
589 if (PageAnon(p))
Xie XiuQicc637b12015-06-24 16:57:30 -0700590 return MF_RECOVERED;
Andi Kleen6a460792009-09-16 11:50:15 +0200591
592 /*
593 * Now truncate the page in the page cache. This is really
594 * more like a "temporary hole punch"
595 * Don't do this for block devices when someone else
596 * has a reference, because it could be file system metadata
597 * and that's not safe to truncate.
598 */
599 mapping = page_mapping(p);
600 if (!mapping) {
601 /*
602 * Page has been teared down in the meanwhile
603 */
Xie XiuQicc637b12015-06-24 16:57:30 -0700604 return MF_FAILED;
Andi Kleen6a460792009-09-16 11:50:15 +0200605 }
606
607 /*
608 * Truncation is a bit tricky. Enable it per file system for now.
609 *
610 * Open: to take i_mutex or not for this? Right now we don't.
611 */
612 if (mapping->a_ops->error_remove_page) {
613 err = mapping->a_ops->error_remove_page(mapping, p);
614 if (err != 0) {
Chen Yucong495367c02016-05-20 16:57:32 -0700615 pr_info("Memory failure: %#lx: Failed to punch page: %d\n",
Joe Perches11705322016-03-17 14:19:50 -0700616 pfn, err);
Andi Kleen6a460792009-09-16 11:50:15 +0200617 } else if (page_has_private(p) &&
618 !try_to_release_page(p, GFP_NOIO)) {
Chen Yucong495367c02016-05-20 16:57:32 -0700619 pr_info("Memory failure: %#lx: failed to release buffers\n",
620 pfn);
Andi Kleen6a460792009-09-16 11:50:15 +0200621 } else {
Xie XiuQicc637b12015-06-24 16:57:30 -0700622 ret = MF_RECOVERED;
Andi Kleen6a460792009-09-16 11:50:15 +0200623 }
624 } else {
625 /*
626 * If the file system doesn't support it just invalidate
627 * This fails on dirty or anything with private pages
628 */
629 if (invalidate_inode_page(p))
Xie XiuQicc637b12015-06-24 16:57:30 -0700630 ret = MF_RECOVERED;
Andi Kleen6a460792009-09-16 11:50:15 +0200631 else
Chen Yucong495367c02016-05-20 16:57:32 -0700632 pr_info("Memory failure: %#lx: Failed to invalidate\n",
633 pfn);
Andi Kleen6a460792009-09-16 11:50:15 +0200634 }
635 return ret;
636}
637
638/*
Zhi Yong Wu549543d2014-01-21 15:49:08 -0800639 * Dirty pagecache page
Andi Kleen6a460792009-09-16 11:50:15 +0200640 * Issues: when the error hit a hole page the error is not properly
641 * propagated.
642 */
643static int me_pagecache_dirty(struct page *p, unsigned long pfn)
644{
645 struct address_space *mapping = page_mapping(p);
646
647 SetPageError(p);
648 /* TBD: print more information about the file. */
649 if (mapping) {
650 /*
651 * IO error will be reported by write(), fsync(), etc.
652 * who check the mapping.
653 * This way the application knows that something went
654 * wrong with its dirty file data.
655 *
656 * There's one open issue:
657 *
658 * The EIO will be only reported on the next IO
659 * operation and then cleared through the IO map.
660 * Normally Linux has two mechanisms to pass IO error
661 * first through the AS_EIO flag in the address space
662 * and then through the PageError flag in the page.
663 * Since we drop pages on memory failure handling the
664 * only mechanism open to use is through AS_AIO.
665 *
666 * This has the disadvantage that it gets cleared on
667 * the first operation that returns an error, while
668 * the PageError bit is more sticky and only cleared
669 * when the page is reread or dropped. If an
670 * application assumes it will always get error on
671 * fsync, but does other operations on the fd before
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300672 * and the page is dropped between then the error
Andi Kleen6a460792009-09-16 11:50:15 +0200673 * will not be properly reported.
674 *
675 * This can already happen even without hwpoisoned
676 * pages: first on metadata IO errors (which only
677 * report through AS_EIO) or when the page is dropped
678 * at the wrong time.
679 *
680 * So right now we assume that the application DTRT on
681 * the first EIO, but we're not worse than other parts
682 * of the kernel.
683 */
684 mapping_set_error(mapping, EIO);
685 }
686
687 return me_pagecache_clean(p, pfn);
688}
689
690/*
691 * Clean and dirty swap cache.
692 *
693 * Dirty swap cache page is tricky to handle. The page could live both in page
694 * cache and swap cache(ie. page is freshly swapped in). So it could be
695 * referenced concurrently by 2 types of PTEs:
696 * normal PTEs and swap PTEs. We try to handle them consistently by calling
697 * try_to_unmap(TTU_IGNORE_HWPOISON) to convert the normal PTEs to swap PTEs,
698 * and then
699 * - clear dirty bit to prevent IO
700 * - remove from LRU
701 * - but keep in the swap cache, so that when we return to it on
702 * a later page fault, we know the application is accessing
703 * corrupted data and shall be killed (we installed simple
704 * interception code in do_swap_page to catch it).
705 *
706 * Clean swap cache pages can be directly isolated. A later page fault will
707 * bring in the known good data from disk.
708 */
709static int me_swapcache_dirty(struct page *p, unsigned long pfn)
710{
Andi Kleen6a460792009-09-16 11:50:15 +0200711 ClearPageDirty(p);
712 /* Trigger EIO in shmem: */
713 ClearPageUptodate(p);
714
Wu Fengguangdc2a1cb2009-12-16 12:19:58 +0100715 if (!delete_from_lru_cache(p))
Xie XiuQicc637b12015-06-24 16:57:30 -0700716 return MF_DELAYED;
Wu Fengguangdc2a1cb2009-12-16 12:19:58 +0100717 else
Xie XiuQicc637b12015-06-24 16:57:30 -0700718 return MF_FAILED;
Andi Kleen6a460792009-09-16 11:50:15 +0200719}
720
721static int me_swapcache_clean(struct page *p, unsigned long pfn)
722{
Andi Kleen6a460792009-09-16 11:50:15 +0200723 delete_from_swap_cache(p);
Wu Fengguange43c3af2009-09-29 13:16:20 +0800724
Wu Fengguangdc2a1cb2009-12-16 12:19:58 +0100725 if (!delete_from_lru_cache(p))
Xie XiuQicc637b12015-06-24 16:57:30 -0700726 return MF_RECOVERED;
Wu Fengguangdc2a1cb2009-12-16 12:19:58 +0100727 else
Xie XiuQicc637b12015-06-24 16:57:30 -0700728 return MF_FAILED;
Andi Kleen6a460792009-09-16 11:50:15 +0200729}
730
731/*
732 * Huge pages. Needs work.
733 * Issues:
Naoya Horiguchi93f70f92010-05-28 09:29:20 +0900734 * - Error on hugepage is contained in hugepage unit (not in raw page unit.)
735 * To narrow down kill region to one page, we need to break up pmd.
Andi Kleen6a460792009-09-16 11:50:15 +0200736 */
737static int me_huge_page(struct page *p, unsigned long pfn)
738{
Naoya Horiguchi6de2b1a2010-09-08 10:19:36 +0900739 int res = 0;
Naoya Horiguchi93f70f92010-05-28 09:29:20 +0900740 struct page *hpage = compound_head(p);
Naoya Horiguchi2491ffe2015-06-24 16:56:53 -0700741
742 if (!PageHuge(hpage))
743 return MF_DELAYED;
744
Naoya Horiguchi93f70f92010-05-28 09:29:20 +0900745 /*
746 * We can safely recover from error on free or reserved (i.e.
747 * not in-use) hugepage by dequeuing it from freelist.
748 * To check whether a hugepage is in-use or not, we can't use
749 * page->lru because it can be used in other hugepage operations,
750 * such as __unmap_hugepage_range() and gather_surplus_pages().
751 * So instead we use page_mapping() and PageAnon().
Naoya Horiguchi93f70f92010-05-28 09:29:20 +0900752 */
753 if (!(page_mapping(hpage) || PageAnon(hpage))) {
Naoya Horiguchi6de2b1a2010-09-08 10:19:36 +0900754 res = dequeue_hwpoisoned_huge_page(hpage);
755 if (!res)
Xie XiuQicc637b12015-06-24 16:57:30 -0700756 return MF_RECOVERED;
Naoya Horiguchi93f70f92010-05-28 09:29:20 +0900757 }
Xie XiuQicc637b12015-06-24 16:57:30 -0700758 return MF_DELAYED;
Andi Kleen6a460792009-09-16 11:50:15 +0200759}
760
761/*
762 * Various page states we can handle.
763 *
764 * A page state is defined by its current page->flags bits.
765 * The table matches them in order and calls the right handler.
766 *
767 * This is quite tricky because we can access page at any time
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300768 * in its live cycle, so all accesses have to be extremely careful.
Andi Kleen6a460792009-09-16 11:50:15 +0200769 *
770 * This is not complete. More states could be added.
771 * For any missing state don't attempt recovery.
772 */
773
774#define dirty (1UL << PG_dirty)
775#define sc (1UL << PG_swapcache)
776#define unevict (1UL << PG_unevictable)
777#define mlock (1UL << PG_mlocked)
778#define writeback (1UL << PG_writeback)
779#define lru (1UL << PG_lru)
780#define swapbacked (1UL << PG_swapbacked)
781#define head (1UL << PG_head)
Andi Kleen6a460792009-09-16 11:50:15 +0200782#define slab (1UL << PG_slab)
Andi Kleen6a460792009-09-16 11:50:15 +0200783#define reserved (1UL << PG_reserved)
784
785static struct page_state {
786 unsigned long mask;
787 unsigned long res;
Xie XiuQicc637b12015-06-24 16:57:30 -0700788 enum mf_action_page_type type;
Andi Kleen6a460792009-09-16 11:50:15 +0200789 int (*action)(struct page *p, unsigned long pfn);
790} error_states[] = {
Xie XiuQicc637b12015-06-24 16:57:30 -0700791 { reserved, reserved, MF_MSG_KERNEL, me_kernel },
Wu Fengguang95d01fc2009-12-16 12:19:58 +0100792 /*
793 * free pages are specially detected outside this table:
794 * PG_buddy pages only make a small fraction of all free pages.
795 */
Andi Kleen6a460792009-09-16 11:50:15 +0200796
797 /*
798 * Could in theory check if slab page is free or if we can drop
799 * currently unused objects without touching them. But just
800 * treat it as standard kernel for now.
801 */
Xie XiuQicc637b12015-06-24 16:57:30 -0700802 { slab, slab, MF_MSG_SLAB, me_kernel },
Andi Kleen6a460792009-09-16 11:50:15 +0200803
Xie XiuQicc637b12015-06-24 16:57:30 -0700804 { head, head, MF_MSG_HUGE, me_huge_page },
Andi Kleen6a460792009-09-16 11:50:15 +0200805
Xie XiuQicc637b12015-06-24 16:57:30 -0700806 { sc|dirty, sc|dirty, MF_MSG_DIRTY_SWAPCACHE, me_swapcache_dirty },
807 { sc|dirty, sc, MF_MSG_CLEAN_SWAPCACHE, me_swapcache_clean },
Andi Kleen6a460792009-09-16 11:50:15 +0200808
Xie XiuQicc637b12015-06-24 16:57:30 -0700809 { mlock|dirty, mlock|dirty, MF_MSG_DIRTY_MLOCKED_LRU, me_pagecache_dirty },
810 { mlock|dirty, mlock, MF_MSG_CLEAN_MLOCKED_LRU, me_pagecache_clean },
Andi Kleen6a460792009-09-16 11:50:15 +0200811
Xie XiuQicc637b12015-06-24 16:57:30 -0700812 { unevict|dirty, unevict|dirty, MF_MSG_DIRTY_UNEVICTABLE_LRU, me_pagecache_dirty },
813 { unevict|dirty, unevict, MF_MSG_CLEAN_UNEVICTABLE_LRU, me_pagecache_clean },
Naoya Horiguchi5f4b9fc2013-02-22 16:35:53 -0800814
Xie XiuQicc637b12015-06-24 16:57:30 -0700815 { lru|dirty, lru|dirty, MF_MSG_DIRTY_LRU, me_pagecache_dirty },
816 { lru|dirty, lru, MF_MSG_CLEAN_LRU, me_pagecache_clean },
Andi Kleen6a460792009-09-16 11:50:15 +0200817
818 /*
819 * Catchall entry: must be at end.
820 */
Xie XiuQicc637b12015-06-24 16:57:30 -0700821 { 0, 0, MF_MSG_UNKNOWN, me_unknown },
Andi Kleen6a460792009-09-16 11:50:15 +0200822};
823
Andi Kleen2326c462009-12-16 12:20:00 +0100824#undef dirty
825#undef sc
826#undef unevict
827#undef mlock
828#undef writeback
829#undef lru
830#undef swapbacked
831#undef head
Andi Kleen2326c462009-12-16 12:20:00 +0100832#undef slab
833#undef reserved
834
Naoya Horiguchiff604cf2012-12-11 16:01:32 -0800835/*
836 * "Dirty/Clean" indication is not 100% accurate due to the possibility of
837 * setting PG_dirty outside page lock. See also comment above set_page_dirty().
838 */
Xie XiuQicc3e2af2015-06-24 16:57:33 -0700839static void action_result(unsigned long pfn, enum mf_action_page_type type,
840 enum mf_result result)
Andi Kleen6a460792009-09-16 11:50:15 +0200841{
Xie XiuQi97f0b132015-06-24 16:57:36 -0700842 trace_memory_failure_event(pfn, type, result);
843
Chen Yucong495367c02016-05-20 16:57:32 -0700844 pr_err("Memory failure: %#lx: recovery action for %s: %s\n",
Naoya Horiguchi64d37a22015-04-15 16:13:05 -0700845 pfn, action_page_types[type], action_name[result]);
Andi Kleen6a460792009-09-16 11:50:15 +0200846}
847
848static int page_action(struct page_state *ps, struct page *p,
Wu Fengguangbd1ce5f2009-12-16 12:19:57 +0100849 unsigned long pfn)
Andi Kleen6a460792009-09-16 11:50:15 +0200850{
851 int result;
Wu Fengguang7456b042009-10-19 08:15:01 +0200852 int count;
Andi Kleen6a460792009-09-16 11:50:15 +0200853
854 result = ps->action(p, pfn);
Wu Fengguang7456b042009-10-19 08:15:01 +0200855
Wu Fengguangbd1ce5f2009-12-16 12:19:57 +0100856 count = page_count(p) - 1;
Xie XiuQicc637b12015-06-24 16:57:30 -0700857 if (ps->action == me_swapcache_dirty && result == MF_DELAYED)
Wu Fengguang138ce282009-12-16 12:19:58 +0100858 count--;
859 if (count != 0) {
Chen Yucong495367c02016-05-20 16:57:32 -0700860 pr_err("Memory failure: %#lx: %s still referenced by %d users\n",
Naoya Horiguchi64d37a22015-04-15 16:13:05 -0700861 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
Naoya Horiguchi4e41a302016-01-15 16:54:07 -0800885 if (!PageHuge(head) && PageTransHuge(head)) {
Naoya Horiguchi98ed2b02015-08-06 15:47:04 -0700886 /*
887 * Non anonymous thp exists only in allocation/free time. We
888 * can't handle such a case correctly, so let's give it up.
889 * This should be better than triggering BUG_ON when kernel
890 * tries to touch the "partially handled" page.
891 */
892 if (!PageAnon(head)) {
Chen Yucong495367c02016-05-20 16:57:32 -0700893 pr_err("Memory failure: %#lx: non anonymous thp\n",
Naoya Horiguchi98ed2b02015-08-06 15:47:04 -0700894 page_to_pfn(page));
895 return 0;
896 }
Naoya Horiguchiead07f62015-06-24 16:56:48 -0700897 }
898
Konstantin Khlebnikovc2e7e002016-04-28 16:19:03 -0700899 if (get_page_unless_zero(head)) {
900 if (head == compound_head(page))
901 return 1;
902
Chen Yucong495367c02016-05-20 16:57:32 -0700903 pr_info("Memory failure: %#lx cannot catch tail\n",
904 page_to_pfn(page));
Konstantin Khlebnikovc2e7e002016-04-28 16:19:03 -0700905 put_page(head);
906 }
907
908 return 0;
Naoya Horiguchiead07f62015-06-24 16:56:48 -0700909}
910EXPORT_SYMBOL_GPL(get_hwpoison_page);
911
Andi Kleen6a460792009-09-16 11:50:15 +0200912/*
913 * Do all that is necessary to remove user space mappings. Unmap
914 * the pages and send SIGBUS to the processes if the data was dirty.
915 */
Wu Fengguang1668bfd2009-12-16 12:19:58 +0100916static int hwpoison_user_mappings(struct page *p, unsigned long pfn,
Naoya Horiguchi54b9dd12014-01-23 15:53:14 -0800917 int trapno, int flags, struct page **hpagep)
Andi Kleen6a460792009-09-16 11:50:15 +0200918{
919 enum ttu_flags ttu = TTU_UNMAP | TTU_IGNORE_MLOCK | TTU_IGNORE_ACCESS;
920 struct address_space *mapping;
921 LIST_HEAD(tokill);
922 int ret;
Tony Luck6751ed62012-07-11 10:20:47 -0700923 int kill = 1, forcekill;
Naoya Horiguchi54b9dd12014-01-23 15:53:14 -0800924 struct page *hpage = *hpagep;
Naoya Horiguchi0b42ce02017-05-03 14:56:22 -0700925 bool mlocked = PageMlocked(hpage);
Andi Kleen6a460792009-09-16 11:50:15 +0200926
Naoya Horiguchi93a9eb32014-07-30 16:08:28 -0700927 /*
928 * Here we are interested only in user-mapped pages, so skip any
929 * other types of pages.
930 */
931 if (PageReserved(p) || PageSlab(p))
932 return SWAP_SUCCESS;
933 if (!(PageLRU(hpage) || PageHuge(p)))
Wu Fengguang1668bfd2009-12-16 12:19:58 +0100934 return SWAP_SUCCESS;
Andi Kleen6a460792009-09-16 11:50:15 +0200935
Andi Kleen6a460792009-09-16 11:50:15 +0200936 /*
937 * This check implies we don't kill processes if their pages
938 * are in the swap cache early. Those are always late kills.
939 */
Naoya Horiguchi7af446a2010-05-28 09:29:17 +0900940 if (!page_mapped(hpage))
Wu Fengguang1668bfd2009-12-16 12:19:58 +0100941 return SWAP_SUCCESS;
942
Naoya Horiguchi52089b12014-07-30 16:08:30 -0700943 if (PageKsm(p)) {
Chen Yucong495367c02016-05-20 16:57:32 -0700944 pr_err("Memory failure: %#lx: can't handle KSM pages.\n", pfn);
Wu Fengguang1668bfd2009-12-16 12:19:58 +0100945 return SWAP_FAIL;
Naoya Horiguchi52089b12014-07-30 16:08:30 -0700946 }
Andi Kleen6a460792009-09-16 11:50:15 +0200947
948 if (PageSwapCache(p)) {
Chen Yucong495367c02016-05-20 16:57:32 -0700949 pr_err("Memory failure: %#lx: keeping poisoned page in swap cache\n",
950 pfn);
Andi Kleen6a460792009-09-16 11:50:15 +0200951 ttu |= TTU_IGNORE_HWPOISON;
952 }
953
954 /*
955 * Propagate the dirty bit from PTEs to struct page first, because we
956 * need this to decide if we should kill or just drop the page.
Wu Fengguangdb0480b2009-12-16 12:19:58 +0100957 * XXX: the dirty test could be racy: set_page_dirty() may not always
958 * be called inside page lock (it's recommended but not enforced).
Andi Kleen6a460792009-09-16 11:50:15 +0200959 */
Naoya Horiguchi7af446a2010-05-28 09:29:17 +0900960 mapping = page_mapping(hpage);
Tony Luck6751ed62012-07-11 10:20:47 -0700961 if (!(flags & MF_MUST_KILL) && !PageDirty(hpage) && mapping &&
Naoya Horiguchi7af446a2010-05-28 09:29:17 +0900962 mapping_cap_writeback_dirty(mapping)) {
963 if (page_mkclean(hpage)) {
964 SetPageDirty(hpage);
Andi Kleen6a460792009-09-16 11:50:15 +0200965 } else {
966 kill = 0;
967 ttu |= TTU_IGNORE_HWPOISON;
Chen Yucong495367c02016-05-20 16:57:32 -0700968 pr_info("Memory failure: %#lx: corrupted page was clean: dropped without side effects\n",
Andi Kleen6a460792009-09-16 11:50:15 +0200969 pfn);
970 }
971 }
972
Jin Dongminga6d30dd2011-02-01 15:52:40 -0800973 /*
Andi Kleen6a460792009-09-16 11:50:15 +0200974 * First collect all the processes that have the page
975 * mapped in dirty form. This has to be done before try_to_unmap,
976 * because ttu takes the rmap data structures down.
977 *
978 * Error handling: We ignore errors here because
979 * there's nothing that can be done.
980 */
981 if (kill)
Naoya Horiguchi415c64c2015-06-24 16:56:45 -0700982 collect_procs(hpage, &tokill, flags & MF_ACTION_REQUIRED);
Andi Kleen6a460792009-09-16 11:50:15 +0200983
Naoya Horiguchi415c64c2015-06-24 16:56:45 -0700984 ret = try_to_unmap(hpage, ttu);
Andi Kleen6a460792009-09-16 11:50:15 +0200985 if (ret != SWAP_SUCCESS)
Chen Yucong495367c02016-05-20 16:57:32 -0700986 pr_err("Memory failure: %#lx: failed to unmap page (mapcount=%d)\n",
Joe Perches11705322016-03-17 14:19:50 -0700987 pfn, page_mapcount(hpage));
Jin Dongminga6d30dd2011-02-01 15:52:40 -0800988
Andi Kleen6a460792009-09-16 11:50:15 +0200989 /*
Naoya Horiguchi0b42ce02017-05-03 14:56:22 -0700990 * try_to_unmap() might put mlocked page in lru cache, so call
991 * shake_page() again to ensure that it's flushed.
992 */
993 if (mlocked)
994 shake_page(hpage, 0);
995
996 /*
Andi Kleen6a460792009-09-16 11:50:15 +0200997 * Now that the dirty bit has been propagated to the
998 * struct page and all unmaps done we can decide if
999 * killing is needed or not. Only kill when the page
Tony Luck6751ed62012-07-11 10:20:47 -07001000 * was dirty or the process is not restartable,
1001 * otherwise the tokill list is merely
Andi Kleen6a460792009-09-16 11:50:15 +02001002 * freed. When there was a problem unmapping earlier
1003 * use a more force-full uncatchable kill to prevent
1004 * any accesses to the poisoned memory.
1005 */
Naoya Horiguchi415c64c2015-06-24 16:56:45 -07001006 forcekill = PageDirty(hpage) || (flags & MF_MUST_KILL);
Tony Luck6751ed62012-07-11 10:20:47 -07001007 kill_procs(&tokill, forcekill, trapno,
Tony Luck7329bbe2011-12-13 09:27:58 -08001008 ret != SWAP_SUCCESS, p, pfn, flags);
Wu Fengguang1668bfd2009-12-16 12:19:58 +01001009
1010 return ret;
Andi Kleen6a460792009-09-16 11:50:15 +02001011}
1012
Naoya Horiguchi7013feb2010-05-28 09:29:18 +09001013static void set_page_hwpoison_huge_page(struct page *hpage)
1014{
1015 int i;
Wanpeng Lif9121152013-09-11 14:22:52 -07001016 int nr_pages = 1 << compound_order(hpage);
Naoya Horiguchi7013feb2010-05-28 09:29:18 +09001017 for (i = 0; i < nr_pages; i++)
1018 SetPageHWPoison(hpage + i);
1019}
1020
1021static void clear_page_hwpoison_huge_page(struct page *hpage)
1022{
1023 int i;
Wanpeng Lif9121152013-09-11 14:22:52 -07001024 int nr_pages = 1 << compound_order(hpage);
Naoya Horiguchi7013feb2010-05-28 09:29:18 +09001025 for (i = 0; i < nr_pages; i++)
1026 ClearPageHWPoison(hpage + i);
1027}
1028
Tony Luckcd42f4a2011-12-15 10:48:12 -08001029/**
1030 * memory_failure - Handle memory failure of a page.
1031 * @pfn: Page Number of the corrupted page
1032 * @trapno: Trap number reported in the signal to user space.
1033 * @flags: fine tune action taken
1034 *
1035 * This function is called by the low level machine check code
1036 * of an architecture when it detects hardware memory corruption
1037 * of a page. It tries its best to recover, which includes
1038 * dropping pages, killing processes etc.
1039 *
1040 * The function is primarily of use for corruptions that
1041 * happen outside the current execution context (e.g. when
1042 * detected by a background scrubber)
1043 *
1044 * Must run in process context (e.g. a work queue) with interrupts
1045 * enabled and no spinlocks hold.
1046 */
1047int memory_failure(unsigned long pfn, int trapno, int flags)
Andi Kleen6a460792009-09-16 11:50:15 +02001048{
1049 struct page_state *ps;
1050 struct page *p;
Naoya Horiguchi7af446a2010-05-28 09:29:17 +09001051 struct page *hpage;
Naoya Horiguchi415c64c2015-06-24 16:56:45 -07001052 struct page *orig_head;
Andi Kleen6a460792009-09-16 11:50:15 +02001053 int res;
Naoya Horiguchic9fbdd52010-05-28 09:29:19 +09001054 unsigned int nr_pages;
Naoya Horiguchi524fca12013-02-22 16:35:51 -08001055 unsigned long page_flags;
Andi Kleen6a460792009-09-16 11:50:15 +02001056
1057 if (!sysctl_memory_failure_recovery)
1058 panic("Memory failure from trap %d on page %lx", trapno, pfn);
1059
1060 if (!pfn_valid(pfn)) {
Chen Yucong495367c02016-05-20 16:57:32 -07001061 pr_err("Memory failure: %#lx: memory outside kernel control\n",
1062 pfn);
Wu Fengguanga7560fc2009-12-16 12:19:57 +01001063 return -ENXIO;
Andi Kleen6a460792009-09-16 11:50:15 +02001064 }
1065
1066 p = pfn_to_page(pfn);
Naoya Horiguchi415c64c2015-06-24 16:56:45 -07001067 orig_head = hpage = compound_head(p);
Andi Kleen6a460792009-09-16 11:50:15 +02001068 if (TestSetPageHWPoison(p)) {
Chen Yucong495367c02016-05-20 16:57:32 -07001069 pr_err("Memory failure: %#lx: already hardware poisoned\n",
1070 pfn);
Andi Kleen6a460792009-09-16 11:50:15 +02001071 return 0;
1072 }
1073
Naoya Horiguchi4db0e952013-02-22 16:34:05 -08001074 /*
1075 * Currently errors on hugetlbfs pages are measured in hugepage units,
1076 * so nr_pages should be 1 << compound_order. OTOH when errors are on
1077 * transparent hugepages, they are supposed to be split and error
1078 * measurement is done in normal page units. So nr_pages should be one
1079 * in this case.
1080 */
1081 if (PageHuge(p))
1082 nr_pages = 1 << compound_order(hpage);
1083 else /* normal page or thp */
1084 nr_pages = 1;
Naoya Horiguchi8e304562015-09-08 15:03:24 -07001085 num_poisoned_pages_add(nr_pages);
Andi Kleen6a460792009-09-16 11:50:15 +02001086
1087 /*
1088 * We need/can do nothing about count=0 pages.
1089 * 1) it's a free page, and therefore in safe hand:
1090 * prep_new_page() will be the gate keeper.
Naoya Horiguchi8c6c2ec2010-09-08 10:19:38 +09001091 * 2) it's a free hugepage, which is also safe:
1092 * an affected hugepage will be dequeued from hugepage freelist,
1093 * so there's no concern about reusing it ever after.
1094 * 3) it's part of a non-compound high order page.
Andi Kleen6a460792009-09-16 11:50:15 +02001095 * Implies some kernel user: cannot stop them from
1096 * R/W the page; let's pray that the page has been
1097 * used and will be freed some time later.
1098 * In fact it's dangerous to directly bump up page count from 0,
1099 * that may make page_freeze_refs()/page_unfreeze_refs() mismatch.
1100 */
Naoya Horiguchiead07f62015-06-24 16:56:48 -07001101 if (!(flags & MF_COUNT_INCREASED) && !get_hwpoison_page(p)) {
Wu Fengguang8d22ba12009-12-16 12:19:58 +01001102 if (is_free_buddy_page(p)) {
Xie XiuQicc637b12015-06-24 16:57:30 -07001103 action_result(pfn, MF_MSG_BUDDY, MF_DELAYED);
Wu Fengguang8d22ba12009-12-16 12:19:58 +01001104 return 0;
Naoya Horiguchi8c6c2ec2010-09-08 10:19:38 +09001105 } else if (PageHuge(hpage)) {
1106 /*
Chen Yucongb9851942014-05-22 11:54:15 -07001107 * Check "filter hit" and "race with other subpage."
Naoya Horiguchi8c6c2ec2010-09-08 10:19:38 +09001108 */
Jens Axboe7eaceac2011-03-10 08:52:07 +01001109 lock_page(hpage);
Chen Yucongb9851942014-05-22 11:54:15 -07001110 if (PageHWPoison(hpage)) {
1111 if ((hwpoison_filter(p) && TestClearPageHWPoison(p))
1112 || (p != hpage && TestSetPageHWPoison(hpage))) {
Naoya Horiguchi8e304562015-09-08 15:03:24 -07001113 num_poisoned_pages_sub(nr_pages);
Chen Yucongb9851942014-05-22 11:54:15 -07001114 unlock_page(hpage);
1115 return 0;
1116 }
Naoya Horiguchi8c6c2ec2010-09-08 10:19:38 +09001117 }
1118 set_page_hwpoison_huge_page(hpage);
1119 res = dequeue_hwpoisoned_huge_page(hpage);
Xie XiuQicc637b12015-06-24 16:57:30 -07001120 action_result(pfn, MF_MSG_FREE_HUGE,
1121 res ? MF_IGNORED : MF_DELAYED);
Naoya Horiguchi8c6c2ec2010-09-08 10:19:38 +09001122 unlock_page(hpage);
1123 return res;
Wu Fengguang8d22ba12009-12-16 12:19:58 +01001124 } else {
Xie XiuQicc637b12015-06-24 16:57:30 -07001125 action_result(pfn, MF_MSG_KERNEL_HIGH_ORDER, MF_IGNORED);
Wu Fengguang8d22ba12009-12-16 12:19:58 +01001126 return -EBUSY;
1127 }
Andi Kleen6a460792009-09-16 11:50:15 +02001128 }
1129
Naoya Horiguchi415c64c2015-06-24 16:56:45 -07001130 if (!PageHuge(p) && PageTransHuge(hpage)) {
Naoya Horiguchic3901e72016-11-10 10:46:23 -08001131 lock_page(p);
1132 if (!PageAnon(p) || unlikely(split_huge_page(p))) {
1133 unlock_page(p);
1134 if (!PageAnon(p))
Chen Yucong495367c02016-05-20 16:57:32 -07001135 pr_err("Memory failure: %#lx: non anonymous thp\n",
1136 pfn);
Wanpeng Li7f6bf392015-08-14 15:35:08 -07001137 else
Chen Yucong495367c02016-05-20 16:57:32 -07001138 pr_err("Memory failure: %#lx: thp split failed\n",
1139 pfn);
Naoya Horiguchiead07f62015-06-24 16:56:48 -07001140 if (TestClearPageHWPoison(p))
Naoya Horiguchi8e304562015-09-08 15:03:24 -07001141 num_poisoned_pages_sub(nr_pages);
Wanpeng Li665d9da2015-09-08 15:03:21 -07001142 put_hwpoison_page(p);
Naoya Horiguchi415c64c2015-06-24 16:56:45 -07001143 return -EBUSY;
1144 }
Naoya Horiguchic3901e72016-11-10 10:46:23 -08001145 unlock_page(p);
Naoya Horiguchi415c64c2015-06-24 16:56:45 -07001146 VM_BUG_ON_PAGE(!page_count(p), p);
1147 hpage = compound_head(p);
1148 }
1149
Andi Kleen6a460792009-09-16 11:50:15 +02001150 /*
Wu Fengguange43c3af2009-09-29 13:16:20 +08001151 * We ignore non-LRU pages for good reasons.
1152 * - PG_locked is only well defined for LRU pages and a few others
Kirill A. Shutemov48c935a2016-01-15 16:51:24 -08001153 * - to avoid races with __SetPageLocked()
Wu Fengguange43c3af2009-09-29 13:16:20 +08001154 * - to avoid races with __SetPageSlab*() (and more non-atomic ops)
1155 * The check (unnecessarily) ignores LRU pages being isolated and
1156 * walked by the page reclaim code, however that's not a big loss.
1157 */
Naoya Horiguchi09789e52015-05-05 16:23:35 -07001158 if (!PageHuge(p)) {
Naoya Horiguchi415c64c2015-06-24 16:56:45 -07001159 if (!PageLRU(p))
1160 shake_page(p, 0);
1161 if (!PageLRU(p)) {
Jin Dongmingaf241a02011-02-01 15:52:41 -08001162 /*
1163 * shake_page could have turned it free.
1164 */
1165 if (is_free_buddy_page(p)) {
Wanpeng Li2d421ac2013-09-30 13:45:23 -07001166 if (flags & MF_COUNT_INCREASED)
Xie XiuQicc637b12015-06-24 16:57:30 -07001167 action_result(pfn, MF_MSG_BUDDY, MF_DELAYED);
Wanpeng Li2d421ac2013-09-30 13:45:23 -07001168 else
Xie XiuQicc637b12015-06-24 16:57:30 -07001169 action_result(pfn, MF_MSG_BUDDY_2ND,
1170 MF_DELAYED);
Jin Dongmingaf241a02011-02-01 15:52:41 -08001171 return 0;
1172 }
Andi Kleen0474a602009-12-16 12:20:00 +01001173 }
Wu Fengguange43c3af2009-09-29 13:16:20 +08001174 }
Wu Fengguange43c3af2009-09-29 13:16:20 +08001175
Jens Axboe7eaceac2011-03-10 08:52:07 +01001176 lock_page(hpage);
Wu Fengguang847ce402009-12-16 12:19:58 +01001177
1178 /*
Andi Kleenf37d4292014-08-06 16:06:49 -07001179 * The page could have changed compound pages during the locking.
1180 * If this happens just bail out.
1181 */
Naoya Horiguchi415c64c2015-06-24 16:56:45 -07001182 if (PageCompound(p) && compound_head(p) != orig_head) {
Xie XiuQicc637b12015-06-24 16:57:30 -07001183 action_result(pfn, MF_MSG_DIFFERENT_COMPOUND, MF_IGNORED);
Andi Kleenf37d4292014-08-06 16:06:49 -07001184 res = -EBUSY;
1185 goto out;
1186 }
1187
1188 /*
Naoya Horiguchi524fca12013-02-22 16:35:51 -08001189 * We use page flags to determine what action should be taken, but
1190 * the flags can be modified by the error containment action. One
1191 * example is an mlocked page, where PG_mlocked is cleared by
1192 * page_remove_rmap() in try_to_unmap_one(). So to determine page status
1193 * correctly, we save a copy of the page flags at this time.
1194 */
James Morse1419b872017-06-16 14:02:29 -07001195 if (PageHuge(p))
1196 page_flags = hpage->flags;
1197 else
1198 page_flags = p->flags;
Naoya Horiguchi524fca12013-02-22 16:35:51 -08001199
1200 /*
Wu Fengguang847ce402009-12-16 12:19:58 +01001201 * unpoison always clear PG_hwpoison inside page lock
1202 */
1203 if (!PageHWPoison(p)) {
Chen Yucong495367c02016-05-20 16:57:32 -07001204 pr_err("Memory failure: %#lx: just unpoisoned\n", pfn);
Naoya Horiguchi8e304562015-09-08 15:03:24 -07001205 num_poisoned_pages_sub(nr_pages);
Naoya Horiguchia09233f2015-08-06 15:46:58 -07001206 unlock_page(hpage);
Wanpeng Li665d9da2015-09-08 15:03:21 -07001207 put_hwpoison_page(hpage);
Naoya Horiguchia09233f2015-08-06 15:46:58 -07001208 return 0;
Wu Fengguang847ce402009-12-16 12:19:58 +01001209 }
Wu Fengguang7c116f22009-12-16 12:19:59 +01001210 if (hwpoison_filter(p)) {
1211 if (TestClearPageHWPoison(p))
Naoya Horiguchi8e304562015-09-08 15:03:24 -07001212 num_poisoned_pages_sub(nr_pages);
Naoya Horiguchi7af446a2010-05-28 09:29:17 +09001213 unlock_page(hpage);
Wanpeng Li665d9da2015-09-08 15:03:21 -07001214 put_hwpoison_page(hpage);
Wu Fengguang7c116f22009-12-16 12:19:59 +01001215 return 0;
1216 }
Wu Fengguang847ce402009-12-16 12:19:58 +01001217
Chen Yucong0bc1f8b2014-07-02 15:22:37 -07001218 if (!PageHuge(p) && !PageTransTail(p) && !PageLRU(p))
1219 goto identify_page_state;
1220
Naoya Horiguchi7013feb2010-05-28 09:29:18 +09001221 /*
1222 * For error on the tail page, we should set PG_hwpoison
1223 * on the head page to show that the hugepage is hwpoisoned
1224 */
Jin Dongminga6d30dd2011-02-01 15:52:40 -08001225 if (PageHuge(p) && PageTail(p) && TestSetPageHWPoison(hpage)) {
Xie XiuQicc637b12015-06-24 16:57:30 -07001226 action_result(pfn, MF_MSG_POISONED_HUGE, MF_IGNORED);
Naoya Horiguchi7013feb2010-05-28 09:29:18 +09001227 unlock_page(hpage);
Wanpeng Li665d9da2015-09-08 15:03:21 -07001228 put_hwpoison_page(hpage);
Naoya Horiguchi7013feb2010-05-28 09:29:18 +09001229 return 0;
1230 }
1231 /*
1232 * Set PG_hwpoison on all pages in an error hugepage,
1233 * because containment is done in hugepage unit for now.
1234 * Since we have done TestSetPageHWPoison() for the head page with
1235 * page lock held, we can safely set PG_hwpoison bits on tail pages.
1236 */
1237 if (PageHuge(p))
1238 set_page_hwpoison_huge_page(hpage);
1239
Naoya Horiguchi6edd6cc2014-06-04 16:10:35 -07001240 /*
1241 * It's very difficult to mess with pages currently under IO
1242 * and in many cases impossible, so we just avoid it here.
1243 */
Andi Kleen6a460792009-09-16 11:50:15 +02001244 wait_on_page_writeback(p);
1245
1246 /*
1247 * Now take care of user space mappings.
Minchan Kime64a7822011-03-22 16:32:44 -07001248 * Abort on fail: __delete_from_page_cache() assumes unmapped page.
Naoya Horiguchi54b9dd12014-01-23 15:53:14 -08001249 *
1250 * When the raw error page is thp tail page, hpage points to the raw
1251 * page after thp split.
Andi Kleen6a460792009-09-16 11:50:15 +02001252 */
Naoya Horiguchi54b9dd12014-01-23 15:53:14 -08001253 if (hwpoison_user_mappings(p, pfn, trapno, flags, &hpage)
1254 != SWAP_SUCCESS) {
Xie XiuQicc637b12015-06-24 16:57:30 -07001255 action_result(pfn, MF_MSG_UNMAP_FAILED, MF_IGNORED);
Wu Fengguang1668bfd2009-12-16 12:19:58 +01001256 res = -EBUSY;
1257 goto out;
1258 }
Andi Kleen6a460792009-09-16 11:50:15 +02001259
1260 /*
1261 * Torn down by someone else?
1262 */
Wu Fengguangdc2a1cb2009-12-16 12:19:58 +01001263 if (PageLRU(p) && !PageSwapCache(p) && p->mapping == NULL) {
Xie XiuQicc637b12015-06-24 16:57:30 -07001264 action_result(pfn, MF_MSG_TRUNCATED_LRU, MF_IGNORED);
Wu Fengguangd95ea512009-12-16 12:19:58 +01001265 res = -EBUSY;
Andi Kleen6a460792009-09-16 11:50:15 +02001266 goto out;
1267 }
1268
Chen Yucong0bc1f8b2014-07-02 15:22:37 -07001269identify_page_state:
Andi Kleen6a460792009-09-16 11:50:15 +02001270 res = -EBUSY;
Naoya Horiguchi524fca12013-02-22 16:35:51 -08001271 /*
1272 * The first check uses the current page flags which may not have any
1273 * relevant information. The second check with the saved page flagss is
1274 * carried out only if the first check can't determine the page status.
1275 */
1276 for (ps = error_states;; ps++)
1277 if ((p->flags & ps->mask) == ps->res)
Andi Kleen6a460792009-09-16 11:50:15 +02001278 break;
Wanpeng Li841fcc52013-09-11 14:22:50 -07001279
1280 page_flags |= (p->flags & (1UL << PG_dirty));
1281
Naoya Horiguchi524fca12013-02-22 16:35:51 -08001282 if (!ps->mask)
1283 for (ps = error_states;; ps++)
1284 if ((page_flags & ps->mask) == ps->res)
1285 break;
1286 res = page_action(ps, p, pfn);
Andi Kleen6a460792009-09-16 11:50:15 +02001287out:
Naoya Horiguchi7af446a2010-05-28 09:29:17 +09001288 unlock_page(hpage);
Andi Kleen6a460792009-09-16 11:50:15 +02001289 return res;
1290}
Tony Luckcd42f4a2011-12-15 10:48:12 -08001291EXPORT_SYMBOL_GPL(memory_failure);
Wu Fengguang847ce402009-12-16 12:19:58 +01001292
Huang Yingea8f5fb2011-07-13 13:14:27 +08001293#define MEMORY_FAILURE_FIFO_ORDER 4
1294#define MEMORY_FAILURE_FIFO_SIZE (1 << MEMORY_FAILURE_FIFO_ORDER)
1295
1296struct memory_failure_entry {
1297 unsigned long pfn;
1298 int trapno;
1299 int flags;
1300};
1301
1302struct memory_failure_cpu {
1303 DECLARE_KFIFO(fifo, struct memory_failure_entry,
1304 MEMORY_FAILURE_FIFO_SIZE);
1305 spinlock_t lock;
1306 struct work_struct work;
1307};
1308
1309static DEFINE_PER_CPU(struct memory_failure_cpu, memory_failure_cpu);
1310
1311/**
1312 * memory_failure_queue - Schedule handling memory failure of a page.
1313 * @pfn: Page Number of the corrupted page
1314 * @trapno: Trap number reported in the signal to user space.
1315 * @flags: Flags for memory failure handling
1316 *
1317 * This function is called by the low level hardware error handler
1318 * when it detects hardware memory corruption of a page. It schedules
1319 * the recovering of error page, including dropping pages, killing
1320 * processes etc.
1321 *
1322 * The function is primarily of use for corruptions that
1323 * happen outside the current execution context (e.g. when
1324 * detected by a background scrubber)
1325 *
1326 * Can run in IRQ context.
1327 */
1328void memory_failure_queue(unsigned long pfn, int trapno, int flags)
1329{
1330 struct memory_failure_cpu *mf_cpu;
1331 unsigned long proc_flags;
1332 struct memory_failure_entry entry = {
1333 .pfn = pfn,
1334 .trapno = trapno,
1335 .flags = flags,
1336 };
1337
1338 mf_cpu = &get_cpu_var(memory_failure_cpu);
1339 spin_lock_irqsave(&mf_cpu->lock, proc_flags);
Stefani Seibold498d3192013-11-14 14:32:17 -08001340 if (kfifo_put(&mf_cpu->fifo, entry))
Huang Yingea8f5fb2011-07-13 13:14:27 +08001341 schedule_work_on(smp_processor_id(), &mf_cpu->work);
1342 else
Joe Perches8e33a522013-07-25 11:53:25 -07001343 pr_err("Memory failure: buffer overflow when queuing memory failure at %#lx\n",
Huang Yingea8f5fb2011-07-13 13:14:27 +08001344 pfn);
1345 spin_unlock_irqrestore(&mf_cpu->lock, proc_flags);
1346 put_cpu_var(memory_failure_cpu);
1347}
1348EXPORT_SYMBOL_GPL(memory_failure_queue);
1349
1350static void memory_failure_work_func(struct work_struct *work)
1351{
1352 struct memory_failure_cpu *mf_cpu;
1353 struct memory_failure_entry entry = { 0, };
1354 unsigned long proc_flags;
1355 int gotten;
1356
Christoph Lameter7c8e0182014-06-04 16:07:56 -07001357 mf_cpu = this_cpu_ptr(&memory_failure_cpu);
Huang Yingea8f5fb2011-07-13 13:14:27 +08001358 for (;;) {
1359 spin_lock_irqsave(&mf_cpu->lock, proc_flags);
1360 gotten = kfifo_get(&mf_cpu->fifo, &entry);
1361 spin_unlock_irqrestore(&mf_cpu->lock, proc_flags);
1362 if (!gotten)
1363 break;
Naveen N. Raocf870c72013-07-10 14:57:01 +05301364 if (entry.flags & MF_SOFT_OFFLINE)
1365 soft_offline_page(pfn_to_page(entry.pfn), entry.flags);
1366 else
1367 memory_failure(entry.pfn, entry.trapno, entry.flags);
Huang Yingea8f5fb2011-07-13 13:14:27 +08001368 }
1369}
1370
1371static int __init memory_failure_init(void)
1372{
1373 struct memory_failure_cpu *mf_cpu;
1374 int cpu;
1375
1376 for_each_possible_cpu(cpu) {
1377 mf_cpu = &per_cpu(memory_failure_cpu, cpu);
1378 spin_lock_init(&mf_cpu->lock);
1379 INIT_KFIFO(mf_cpu->fifo);
1380 INIT_WORK(&mf_cpu->work, memory_failure_work_func);
1381 }
1382
1383 return 0;
1384}
1385core_initcall(memory_failure_init);
1386
Naoya Horiguchia5f65102015-11-05 18:47:26 -08001387#define unpoison_pr_info(fmt, pfn, rs) \
1388({ \
1389 if (__ratelimit(rs)) \
1390 pr_info(fmt, pfn); \
1391})
1392
Wu Fengguang847ce402009-12-16 12:19:58 +01001393/**
1394 * unpoison_memory - Unpoison a previously poisoned page
1395 * @pfn: Page number of the to be unpoisoned page
1396 *
1397 * Software-unpoison a page that has been poisoned by
1398 * memory_failure() earlier.
1399 *
1400 * This is only done on the software-level, so it only works
1401 * for linux injected failures, not real hardware failures
1402 *
1403 * Returns 0 for success, otherwise -errno.
1404 */
1405int unpoison_memory(unsigned long pfn)
1406{
1407 struct page *page;
1408 struct page *p;
1409 int freeit = 0;
Naoya Horiguchic9fbdd52010-05-28 09:29:19 +09001410 unsigned int nr_pages;
Naoya Horiguchia5f65102015-11-05 18:47:26 -08001411 static DEFINE_RATELIMIT_STATE(unpoison_rs, DEFAULT_RATELIMIT_INTERVAL,
1412 DEFAULT_RATELIMIT_BURST);
Wu Fengguang847ce402009-12-16 12:19:58 +01001413
1414 if (!pfn_valid(pfn))
1415 return -ENXIO;
1416
1417 p = pfn_to_page(pfn);
1418 page = compound_head(p);
1419
1420 if (!PageHWPoison(p)) {
Chen Yucong495367c02016-05-20 16:57:32 -07001421 unpoison_pr_info("Unpoison: Page was already unpoisoned %#lx\n",
Naoya Horiguchia5f65102015-11-05 18:47:26 -08001422 pfn, &unpoison_rs);
Wu Fengguang847ce402009-12-16 12:19:58 +01001423 return 0;
1424 }
1425
Naoya Horiguchi230ac712015-09-08 15:03:29 -07001426 if (page_count(page) > 1) {
Chen Yucong495367c02016-05-20 16:57:32 -07001427 unpoison_pr_info("Unpoison: Someone grabs the hwpoison page %#lx\n",
Naoya Horiguchia5f65102015-11-05 18:47:26 -08001428 pfn, &unpoison_rs);
Naoya Horiguchi230ac712015-09-08 15:03:29 -07001429 return 0;
1430 }
1431
1432 if (page_mapped(page)) {
Chen Yucong495367c02016-05-20 16:57:32 -07001433 unpoison_pr_info("Unpoison: Someone maps the hwpoison page %#lx\n",
Naoya Horiguchia5f65102015-11-05 18:47:26 -08001434 pfn, &unpoison_rs);
Naoya Horiguchi230ac712015-09-08 15:03:29 -07001435 return 0;
1436 }
1437
1438 if (page_mapping(page)) {
Chen Yucong495367c02016-05-20 16:57:32 -07001439 unpoison_pr_info("Unpoison: the hwpoison page has non-NULL mapping %#lx\n",
Naoya Horiguchia5f65102015-11-05 18:47:26 -08001440 pfn, &unpoison_rs);
Naoya Horiguchi230ac712015-09-08 15:03:29 -07001441 return 0;
1442 }
1443
Wanpeng Li0cea3fd2013-09-11 14:22:53 -07001444 /*
1445 * unpoison_memory() can encounter thp only when the thp is being
1446 * worked by memory_failure() and the page lock is not held yet.
1447 * In such case, we yield to memory_failure() and make unpoison fail.
1448 */
Wanpeng Lie76d30e2013-09-30 13:45:22 -07001449 if (!PageHuge(page) && PageTransHuge(page)) {
Chen Yucong495367c02016-05-20 16:57:32 -07001450 unpoison_pr_info("Unpoison: Memory failure is now running on %#lx\n",
Naoya Horiguchia5f65102015-11-05 18:47:26 -08001451 pfn, &unpoison_rs);
Naoya Horiguchiead07f62015-06-24 16:56:48 -07001452 return 0;
Wanpeng Li0cea3fd2013-09-11 14:22:53 -07001453 }
1454
Wanpeng Lif9121152013-09-11 14:22:52 -07001455 nr_pages = 1 << compound_order(page);
Naoya Horiguchic9fbdd52010-05-28 09:29:19 +09001456
Naoya Horiguchiead07f62015-06-24 16:56:48 -07001457 if (!get_hwpoison_page(p)) {
Naoya Horiguchi8c6c2ec2010-09-08 10:19:38 +09001458 /*
1459 * Since HWPoisoned hugepage should have non-zero refcount,
1460 * race between memory failure and unpoison seems to happen.
1461 * In such case unpoison fails and memory failure runs
1462 * to the end.
1463 */
1464 if (PageHuge(page)) {
Chen Yucong495367c02016-05-20 16:57:32 -07001465 unpoison_pr_info("Unpoison: Memory failure is now running on free hugepage %#lx\n",
Naoya Horiguchia5f65102015-11-05 18:47:26 -08001466 pfn, &unpoison_rs);
Naoya Horiguchi8c6c2ec2010-09-08 10:19:38 +09001467 return 0;
1468 }
Wu Fengguang847ce402009-12-16 12:19:58 +01001469 if (TestClearPageHWPoison(p))
Naoya Horiguchi8e304562015-09-08 15:03:24 -07001470 num_poisoned_pages_dec();
Chen Yucong495367c02016-05-20 16:57:32 -07001471 unpoison_pr_info("Unpoison: Software-unpoisoned free page %#lx\n",
Naoya Horiguchia5f65102015-11-05 18:47:26 -08001472 pfn, &unpoison_rs);
Wu Fengguang847ce402009-12-16 12:19:58 +01001473 return 0;
1474 }
1475
Jens Axboe7eaceac2011-03-10 08:52:07 +01001476 lock_page(page);
Wu Fengguang847ce402009-12-16 12:19:58 +01001477 /*
1478 * This test is racy because PG_hwpoison is set outside of page lock.
1479 * That's acceptable because that won't trigger kernel panic. Instead,
1480 * the PG_hwpoison page will be caught and isolated on the entrance to
1481 * the free buddy page pool.
1482 */
Naoya Horiguchic9fbdd52010-05-28 09:29:19 +09001483 if (TestClearPageHWPoison(page)) {
Chen Yucong495367c02016-05-20 16:57:32 -07001484 unpoison_pr_info("Unpoison: Software-unpoisoned page %#lx\n",
Naoya Horiguchia5f65102015-11-05 18:47:26 -08001485 pfn, &unpoison_rs);
Naoya Horiguchi8e304562015-09-08 15:03:24 -07001486 num_poisoned_pages_sub(nr_pages);
Wu Fengguang847ce402009-12-16 12:19:58 +01001487 freeit = 1;
Naoya Horiguchi6a901812010-09-08 10:19:40 +09001488 if (PageHuge(page))
1489 clear_page_hwpoison_huge_page(page);
Wu Fengguang847ce402009-12-16 12:19:58 +01001490 }
1491 unlock_page(page);
1492
Wanpeng Li665d9da2015-09-08 15:03:21 -07001493 put_hwpoison_page(page);
Wanpeng Li3ba5eeb2013-09-11 14:23:01 -07001494 if (freeit && !(pfn == my_zero_pfn(0) && page_count(p) == 1))
Wanpeng Li665d9da2015-09-08 15:03:21 -07001495 put_hwpoison_page(page);
Wu Fengguang847ce402009-12-16 12:19:58 +01001496
1497 return 0;
1498}
1499EXPORT_SYMBOL(unpoison_memory);
Andi Kleenfacb6012009-12-16 12:20:00 +01001500
1501static struct page *new_page(struct page *p, unsigned long private, int **x)
1502{
Andi Kleen12686d12009-12-16 12:20:01 +01001503 int nid = page_to_nid(p);
Naoya Horiguchid950b952010-09-08 10:19:39 +09001504 if (PageHuge(p))
1505 return alloc_huge_page_node(page_hstate(compound_head(p)),
1506 nid);
1507 else
Vlastimil Babka96db8002015-09-08 15:03:50 -07001508 return __alloc_pages_node(nid, GFP_HIGHUSER_MOVABLE, 0);
Andi Kleenfacb6012009-12-16 12:20:00 +01001509}
1510
1511/*
1512 * Safely get reference count of an arbitrary page.
1513 * Returns 0 for a free page, -EIO for a zero refcount page
1514 * that is not free, and 1 for any other page type.
1515 * For 1 the page is returned with increased page count, otherwise not.
1516 */
Naoya Horiguchiaf8fae72013-02-22 16:34:03 -08001517static int __get_any_page(struct page *p, unsigned long pfn, int flags)
Andi Kleenfacb6012009-12-16 12:20:00 +01001518{
1519 int ret;
1520
1521 if (flags & MF_COUNT_INCREASED)
1522 return 1;
1523
1524 /*
Naoya Horiguchid950b952010-09-08 10:19:39 +09001525 * When the target page is a free hugepage, just remove it
1526 * from free hugepage list.
1527 */
Naoya Horiguchiead07f62015-06-24 16:56:48 -07001528 if (!get_hwpoison_page(p)) {
Naoya Horiguchid950b952010-09-08 10:19:39 +09001529 if (PageHuge(p)) {
Borislav Petkov71dd0b82012-05-29 15:06:16 -07001530 pr_info("%s: %#lx free huge page\n", __func__, pfn);
Naoya Horiguchiaf8fae72013-02-22 16:34:03 -08001531 ret = 0;
Naoya Horiguchid950b952010-09-08 10:19:39 +09001532 } else if (is_free_buddy_page(p)) {
Borislav Petkov71dd0b82012-05-29 15:06:16 -07001533 pr_info("%s: %#lx free buddy page\n", __func__, pfn);
Andi Kleenfacb6012009-12-16 12:20:00 +01001534 ret = 0;
1535 } else {
Borislav Petkov71dd0b82012-05-29 15:06:16 -07001536 pr_info("%s: %#lx: unknown zero refcount page type %lx\n",
1537 __func__, pfn, p->flags);
Andi Kleenfacb6012009-12-16 12:20:00 +01001538 ret = -EIO;
1539 }
1540 } else {
1541 /* Not a free page */
1542 ret = 1;
1543 }
Andi Kleenfacb6012009-12-16 12:20:00 +01001544 return ret;
1545}
1546
Naoya Horiguchiaf8fae72013-02-22 16:34:03 -08001547static int get_any_page(struct page *page, unsigned long pfn, int flags)
1548{
1549 int ret = __get_any_page(page, pfn, flags);
1550
1551 if (ret == 1 && !PageHuge(page) && !PageLRU(page)) {
1552 /*
1553 * Try to free it.
1554 */
Wanpeng Li665d9da2015-09-08 15:03:21 -07001555 put_hwpoison_page(page);
Naoya Horiguchiaf8fae72013-02-22 16:34:03 -08001556 shake_page(page, 1);
1557
1558 /*
1559 * Did it turn free?
1560 */
1561 ret = __get_any_page(page, pfn, 0);
Naoya Horiguchid96b3392016-01-15 16:54:03 -08001562 if (ret == 1 && !PageLRU(page)) {
Wanpeng Li4f32be62015-08-14 15:34:56 -07001563 /* Drop page reference which is from __get_any_page() */
Wanpeng Li665d9da2015-09-08 15:03:21 -07001564 put_hwpoison_page(page);
Naoya Horiguchiaf8fae72013-02-22 16:34:03 -08001565 pr_info("soft_offline: %#lx: unknown non LRU page type %lx\n",
1566 pfn, page->flags);
1567 return -EIO;
1568 }
1569 }
1570 return ret;
1571}
1572
Naoya Horiguchid950b952010-09-08 10:19:39 +09001573static int soft_offline_huge_page(struct page *page, int flags)
1574{
1575 int ret;
1576 unsigned long pfn = page_to_pfn(page);
1577 struct page *hpage = compound_head(page);
Naoya Horiguchib8ec1ce2013-09-11 14:22:01 -07001578 LIST_HEAD(pagelist);
Naoya Horiguchid950b952010-09-08 10:19:39 +09001579
Naoya Horiguchiaf8fae72013-02-22 16:34:03 -08001580 /*
1581 * This double-check of PageHWPoison is to avoid the race with
1582 * memory_failure(). See also comment in __soft_offline_page().
1583 */
1584 lock_page(hpage);
Xishi Qiu0ebff322013-02-22 16:33:59 -08001585 if (PageHWPoison(hpage)) {
Naoya Horiguchiaf8fae72013-02-22 16:34:03 -08001586 unlock_page(hpage);
Wanpeng Li665d9da2015-09-08 15:03:21 -07001587 put_hwpoison_page(hpage);
Xishi Qiu0ebff322013-02-22 16:33:59 -08001588 pr_info("soft offline: %#lx hugepage already poisoned\n", pfn);
Naoya Horiguchiaf8fae72013-02-22 16:34:03 -08001589 return -EBUSY;
Xishi Qiu0ebff322013-02-22 16:33:59 -08001590 }
Naoya Horiguchiaf8fae72013-02-22 16:34:03 -08001591 unlock_page(hpage);
Naoya Horiguchid950b952010-09-08 10:19:39 +09001592
Naoya Horiguchibcc54222015-04-15 16:14:38 -07001593 ret = isolate_huge_page(hpage, &pagelist);
Wanpeng Li03613802015-08-14 15:34:59 -07001594 /*
1595 * get_any_page() and isolate_huge_page() takes a refcount each,
1596 * so need to drop one here.
1597 */
Wanpeng Li665d9da2015-09-08 15:03:21 -07001598 put_hwpoison_page(hpage);
Wanpeng Li03613802015-08-14 15:34:59 -07001599 if (!ret) {
Naoya Horiguchibcc54222015-04-15 16:14:38 -07001600 pr_info("soft offline: %#lx hugepage failed to isolate\n", pfn);
1601 return -EBUSY;
1602 }
1603
David Rientjes68711a72014-06-04 16:08:25 -07001604 ret = migrate_pages(&pagelist, new_page, NULL, MPOL_MF_MOVE_ALL,
Naoya Horiguchib8ec1ce2013-09-11 14:22:01 -07001605 MIGRATE_SYNC, MR_MEMORY_FAILURE);
Naoya Horiguchid950b952010-09-08 10:19:39 +09001606 if (ret) {
Dean Nelsondd73e852011-10-31 17:09:04 -07001607 pr_info("soft offline: %#lx: migration failed %d, type %lx\n",
1608 pfn, ret, page->flags);
Punit Agrawald494cab2017-06-02 14:46:40 -07001609 if (!list_empty(&pagelist))
1610 putback_movable_pages(&pagelist);
Naoya Horiguchib8ec1ce2013-09-11 14:22:01 -07001611 if (ret > 0)
1612 ret = -EIO;
Naoya Horiguchiaf8fae72013-02-22 16:34:03 -08001613 } else {
Jianguo Wua49ecbc2013-12-18 17:08:54 -08001614 /* overcommit hugetlb page will be freed to buddy */
1615 if (PageHuge(page)) {
1616 set_page_hwpoison_huge_page(hpage);
1617 dequeue_hwpoisoned_huge_page(hpage);
Naoya Horiguchi8e304562015-09-08 15:03:24 -07001618 num_poisoned_pages_add(1 << compound_order(hpage));
Jianguo Wua49ecbc2013-12-18 17:08:54 -08001619 } else {
1620 SetPageHWPoison(page);
Naoya Horiguchi8e304562015-09-08 15:03:24 -07001621 num_poisoned_pages_inc();
Jianguo Wua49ecbc2013-12-18 17:08:54 -08001622 }
Naoya Horiguchid950b952010-09-08 10:19:39 +09001623 }
Naoya Horiguchid950b952010-09-08 10:19:39 +09001624 return ret;
1625}
1626
Naoya Horiguchiaf8fae72013-02-22 16:34:03 -08001627static int __soft_offline_page(struct page *page, int flags)
1628{
1629 int ret;
1630 unsigned long pfn = page_to_pfn(page);
Andi Kleenfacb6012009-12-16 12:20:00 +01001631
1632 /*
Naoya Horiguchiaf8fae72013-02-22 16:34:03 -08001633 * Check PageHWPoison again inside page lock because PageHWPoison
1634 * is set by memory_failure() outside page lock. Note that
1635 * memory_failure() also double-checks PageHWPoison inside page lock,
1636 * so there's no race between soft_offline_page() and memory_failure().
Andi Kleenfacb6012009-12-16 12:20:00 +01001637 */
Xishi Qiu0ebff322013-02-22 16:33:59 -08001638 lock_page(page);
1639 wait_on_page_writeback(page);
Naoya Horiguchiaf8fae72013-02-22 16:34:03 -08001640 if (PageHWPoison(page)) {
1641 unlock_page(page);
Wanpeng Li665d9da2015-09-08 15:03:21 -07001642 put_hwpoison_page(page);
Naoya Horiguchiaf8fae72013-02-22 16:34:03 -08001643 pr_info("soft offline: %#lx page already poisoned\n", pfn);
1644 return -EBUSY;
1645 }
Andi Kleenfacb6012009-12-16 12:20:00 +01001646 /*
1647 * Try to invalidate first. This should work for
1648 * non dirty unmapped page cache pages.
1649 */
1650 ret = invalidate_inode_page(page);
1651 unlock_page(page);
Andi Kleenfacb6012009-12-16 12:20:00 +01001652 /*
Andi Kleenfacb6012009-12-16 12:20:00 +01001653 * RED-PEN would be better to keep it isolated here, but we
1654 * would need to fix isolation locking first.
1655 */
Andi Kleenfacb6012009-12-16 12:20:00 +01001656 if (ret == 1) {
Wanpeng Li665d9da2015-09-08 15:03:21 -07001657 put_hwpoison_page(page);
Andi Kleenfb46e732010-09-27 23:31:30 +02001658 pr_info("soft_offline: %#lx: invalidated\n", pfn);
Naoya Horiguchiaf8fae72013-02-22 16:34:03 -08001659 SetPageHWPoison(page);
Naoya Horiguchi8e304562015-09-08 15:03:24 -07001660 num_poisoned_pages_inc();
Naoya Horiguchiaf8fae72013-02-22 16:34:03 -08001661 return 0;
Andi Kleenfacb6012009-12-16 12:20:00 +01001662 }
1663
1664 /*
1665 * Simple invalidation didn't work.
1666 * Try to migrate to a new page instead. migrate.c
1667 * handles a large number of cases for us.
1668 */
1669 ret = isolate_lru_page(page);
Konstantin Khlebnikovbd486282011-05-24 17:12:20 -07001670 /*
1671 * Drop page reference which is came from get_any_page()
1672 * successful isolate_lru_page() already took another one.
1673 */
Wanpeng Li665d9da2015-09-08 15:03:21 -07001674 put_hwpoison_page(page);
Andi Kleenfacb6012009-12-16 12:20:00 +01001675 if (!ret) {
1676 LIST_HEAD(pagelist);
Mel Gorman599d0c92016-07-28 15:45:31 -07001677 inc_node_page_state(page, NR_ISOLATED_ANON +
Hugh Dickins9c620e22013-02-22 16:35:14 -08001678 page_is_file_cache(page));
Andi Kleenfacb6012009-12-16 12:20:00 +01001679 list_add(&page->lru, &pagelist);
David Rientjes68711a72014-06-04 16:08:25 -07001680 ret = migrate_pages(&pagelist, new_page, NULL, MPOL_MF_MOVE_ALL,
Hugh Dickins9c620e22013-02-22 16:35:14 -08001681 MIGRATE_SYNC, MR_MEMORY_FAILURE);
Andi Kleenfacb6012009-12-16 12:20:00 +01001682 if (ret) {
Joonsoo Kim59c82b72014-01-21 15:51:17 -08001683 if (!list_empty(&pagelist)) {
1684 list_del(&page->lru);
Mel Gorman599d0c92016-07-28 15:45:31 -07001685 dec_node_page_state(page, NR_ISOLATED_ANON +
Joonsoo Kim59c82b72014-01-21 15:51:17 -08001686 page_is_file_cache(page));
1687 putback_lru_page(page);
1688 }
1689
Andi Kleenfb46e732010-09-27 23:31:30 +02001690 pr_info("soft offline: %#lx: migration failed %d, type %lx\n",
Andi Kleenfacb6012009-12-16 12:20:00 +01001691 pfn, ret, page->flags);
1692 if (ret > 0)
1693 ret = -EIO;
1694 }
1695 } else {
Andi Kleenfb46e732010-09-27 23:31:30 +02001696 pr_info("soft offline: %#lx: isolation failed: %d, page count %d, type %lx\n",
Dean Nelsondd73e852011-10-31 17:09:04 -07001697 pfn, ret, page_count(page), page->flags);
Andi Kleenfacb6012009-12-16 12:20:00 +01001698 }
Andi Kleenfacb6012009-12-16 12:20:00 +01001699 return ret;
1700}
Wanpeng Li86e05772013-09-11 14:22:56 -07001701
Naoya Horiguchiacc14dc2016-01-15 16:57:43 -08001702static int soft_offline_in_use_page(struct page *page, int flags)
1703{
1704 int ret;
1705 struct page *hpage = compound_head(page);
1706
1707 if (!PageHuge(page) && PageTransHuge(hpage)) {
zhongjiang78f42f12019-03-05 15:41:16 -08001708 lock_page(page);
1709 if (!PageAnon(page) || unlikely(split_huge_page(page))) {
1710 unlock_page(page);
1711 if (!PageAnon(page))
Naoya Horiguchi98fd1ef2016-01-15 16:57:46 -08001712 pr_info("soft offline: %#lx: non anonymous thp\n", page_to_pfn(page));
1713 else
1714 pr_info("soft offline: %#lx: thp split failed\n", page_to_pfn(page));
zhongjiang78f42f12019-03-05 15:41:16 -08001715 put_hwpoison_page(page);
Naoya Horiguchiacc14dc2016-01-15 16:57:43 -08001716 return -EBUSY;
1717 }
zhongjiang78f42f12019-03-05 15:41:16 -08001718 unlock_page(page);
Naoya Horiguchiacc14dc2016-01-15 16:57:43 -08001719 }
1720
1721 if (PageHuge(page))
1722 ret = soft_offline_huge_page(page, flags);
1723 else
1724 ret = __soft_offline_page(page, flags);
1725
1726 return ret;
1727}
1728
1729static void soft_offline_free_page(struct page *page)
1730{
1731 if (PageHuge(page)) {
1732 struct page *hpage = compound_head(page);
1733
1734 set_page_hwpoison_huge_page(hpage);
1735 if (!dequeue_hwpoisoned_huge_page(hpage))
1736 num_poisoned_pages_add(1 << compound_order(hpage));
1737 } else {
1738 if (!TestSetPageHWPoison(page))
1739 num_poisoned_pages_inc();
1740 }
1741}
1742
Wanpeng Li86e05772013-09-11 14:22:56 -07001743/**
1744 * soft_offline_page - Soft offline a page.
1745 * @page: page to offline
1746 * @flags: flags. Same as memory_failure().
1747 *
1748 * Returns 0 on success, otherwise negated errno.
1749 *
1750 * Soft offline a page, by migration or invalidation,
1751 * without killing anything. This is for the case when
1752 * a page is not corrupted yet (so it's still valid to access),
1753 * but has had a number of corrected errors and is better taken
1754 * out.
1755 *
1756 * The actual policy on when to do that is maintained by
1757 * user space.
1758 *
1759 * This should never impact any application or cause data loss,
1760 * however it might take some time.
1761 *
1762 * This is not a 100% solution for all memory, but tries to be
1763 * ``good enough'' for the majority of memory.
1764 */
1765int soft_offline_page(struct page *page, int flags)
1766{
1767 int ret;
1768 unsigned long pfn = page_to_pfn(page);
Wanpeng Li86e05772013-09-11 14:22:56 -07001769
1770 if (PageHWPoison(page)) {
1771 pr_info("soft offline: %#lx page already poisoned\n", pfn);
Wanpeng Li1e0e6352015-09-08 15:03:13 -07001772 if (flags & MF_COUNT_INCREASED)
Wanpeng Li665d9da2015-09-08 15:03:21 -07001773 put_hwpoison_page(page);
Wanpeng Li86e05772013-09-11 14:22:56 -07001774 return -EBUSY;
1775 }
Wanpeng Li86e05772013-09-11 14:22:56 -07001776
Vladimir Davydovbfc8c902014-06-04 16:07:18 -07001777 get_online_mems();
Wanpeng Li86e05772013-09-11 14:22:56 -07001778 ret = get_any_page(page, pfn, flags);
Vladimir Davydovbfc8c902014-06-04 16:07:18 -07001779 put_online_mems();
Naoya Horiguchi4e41a302016-01-15 16:54:07 -08001780
Naoya Horiguchiacc14dc2016-01-15 16:57:43 -08001781 if (ret > 0)
1782 ret = soft_offline_in_use_page(page, flags);
1783 else if (ret == 0)
1784 soft_offline_free_page(page);
Naoya Horiguchi4e41a302016-01-15 16:54:07 -08001785
Wanpeng Li86e05772013-09-11 14:22:56 -07001786 return ret;
1787}