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1 | /* |
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 |
10 | * hardware as being corrupted usually due to a 2bit ECC memory or cache |
11 | * failure. |
12 | * |
13 | * Handles page cache pages in various states. The tricky part |
14 | * here is that we can access any page asynchronous to other VM |
15 | * users, because memory failures could happen anytime and anywhere, |
16 | * possibly violating some of their assumptions. This is why this code |
17 | * has to be extremely careful. Generally it tries to use normal locking |
18 | * rules, as in get the standard locks, even if that means the |
19 | * error handling takes potentially a long time. |
20 | * |
21 | * The operation to map back from RMAP chains to processes has to walk |
22 | * the complete process list and has non linear complexity with the number |
23 | * mappings. In short it can be quite slow. But since memory corruptions |
24 | * are rare we hope to get away with this. |
25 | */ |
26 | |
27 | /* |
28 | * Notebook: |
29 | * - hugetlb needs more code |
30 | * - kcore/oldmem/vmcore/mem/kmem check for hwpoison pages |
31 | * - pass bad pages to kdump next kernel |
32 | */ |
33 | #define DEBUG 1 /* remove me in 2.6.34 */ |
34 | #include <linux/kernel.h> |
35 | #include <linux/mm.h> |
36 | #include <linux/page-flags.h> |
37 | #include <linux/kernel-page-flags.h> |
38 | #include <linux/sched.h> |
39 | #include <linux/ksm.h> |
40 | #include <linux/rmap.h> |
41 | #include <linux/pagemap.h> |
42 | #include <linux/swap.h> |
43 | #include <linux/backing-dev.h> |
44 | #include <linux/migrate.h> |
45 | #include <linux/page-isolation.h> |
46 | #include <linux/suspend.h> |
47 | #include <linux/slab.h> |
48 | #include "internal.h" |
49 | |
50 | int sysctl_memory_failure_early_kill __read_mostly = 0; |
51 | |
52 | int sysctl_memory_failure_recovery __read_mostly = 1; |
53 | |
54 | atomic_long_t mce_bad_pages __read_mostly = ATOMIC_LONG_INIT(0); |
55 | |
56 | #if defined(CONFIG_HWPOISON_INJECT) || defined(CONFIG_HWPOISON_INJECT_MODULE) |
57 | |
58 | u32 hwpoison_filter_enable = 0; |
59 | u32 hwpoison_filter_dev_major = ~0U; |
60 | u32 hwpoison_filter_dev_minor = ~0U; |
61 | u64 hwpoison_filter_flags_mask; |
62 | u64 hwpoison_filter_flags_value; |
63 | EXPORT_SYMBOL_GPL(hwpoison_filter_enable); |
64 | EXPORT_SYMBOL_GPL(hwpoison_filter_dev_major); |
65 | EXPORT_SYMBOL_GPL(hwpoison_filter_dev_minor); |
66 | EXPORT_SYMBOL_GPL(hwpoison_filter_flags_mask); |
67 | EXPORT_SYMBOL_GPL(hwpoison_filter_flags_value); |
68 | |
69 | static int hwpoison_filter_dev(struct page *p) |
70 | { |
71 | struct address_space *mapping; |
72 | dev_t dev; |
73 | |
74 | if (hwpoison_filter_dev_major == ~0U && |
75 | hwpoison_filter_dev_minor == ~0U) |
76 | return 0; |
77 | |
78 | /* |
79 | * page_mapping() does not accept slab page |
80 | */ |
81 | if (PageSlab(p)) |
82 | return -EINVAL; |
83 | |
84 | mapping = page_mapping(p); |
85 | if (mapping == NULL || mapping->host == NULL) |
86 | return -EINVAL; |
87 | |
88 | dev = mapping->host->i_sb->s_dev; |
89 | if (hwpoison_filter_dev_major != ~0U && |
90 | hwpoison_filter_dev_major != MAJOR(dev)) |
91 | return -EINVAL; |
92 | if (hwpoison_filter_dev_minor != ~0U && |
93 | hwpoison_filter_dev_minor != MINOR(dev)) |
94 | return -EINVAL; |
95 | |
96 | return 0; |
97 | } |
98 | |
99 | static int hwpoison_filter_flags(struct page *p) |
100 | { |
101 | if (!hwpoison_filter_flags_mask) |
102 | return 0; |
103 | |
104 | if ((stable_page_flags(p) & hwpoison_filter_flags_mask) == |
105 | hwpoison_filter_flags_value) |
106 | return 0; |
107 | else |
108 | return -EINVAL; |
109 | } |
110 | |
111 | /* |
112 | * This allows stress tests to limit test scope to a collection of tasks |
113 | * by putting them under some memcg. This prevents killing unrelated/important |
114 | * processes such as /sbin/init. Note that the target task may share clean |
115 | * pages with init (eg. libc text), which is harmless. If the target task |
116 | * share _dirty_ pages with another task B, the test scheme must make sure B |
117 | * is also included in the memcg. At last, due to race conditions this filter |
118 | * can only guarantee that the page either belongs to the memcg tasks, or is |
119 | * a freed page. |
120 | */ |
121 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP |
122 | u64 hwpoison_filter_memcg; |
123 | EXPORT_SYMBOL_GPL(hwpoison_filter_memcg); |
124 | static int hwpoison_filter_task(struct page *p) |
125 | { |
126 | struct mem_cgroup *mem; |
127 | struct cgroup_subsys_state *css; |
128 | unsigned long ino; |
129 | |
130 | if (!hwpoison_filter_memcg) |
131 | return 0; |
132 | |
133 | mem = try_get_mem_cgroup_from_page(p); |
134 | if (!mem) |
135 | return -EINVAL; |
136 | |
137 | css = mem_cgroup_css(mem); |
138 | /* root_mem_cgroup has NULL dentries */ |
139 | if (!css->cgroup->dentry) |
140 | return -EINVAL; |
141 | |
142 | ino = css->cgroup->dentry->d_inode->i_ino; |
143 | css_put(css); |
144 | |
145 | if (ino != hwpoison_filter_memcg) |
146 | return -EINVAL; |
147 | |
148 | return 0; |
149 | } |
150 | #else |
151 | static int hwpoison_filter_task(struct page *p) { return 0; } |
152 | #endif |
153 | |
154 | int hwpoison_filter(struct page *p) |
155 | { |
156 | if (!hwpoison_filter_enable) |
157 | return 0; |
158 | |
159 | if (hwpoison_filter_dev(p)) |
160 | return -EINVAL; |
161 | |
162 | if (hwpoison_filter_flags(p)) |
163 | return -EINVAL; |
164 | |
165 | if (hwpoison_filter_task(p)) |
166 | return -EINVAL; |
167 | |
168 | return 0; |
169 | } |
170 | #else |
171 | int hwpoison_filter(struct page *p) |
172 | { |
173 | return 0; |
174 | } |
175 | #endif |
176 | |
177 | EXPORT_SYMBOL_GPL(hwpoison_filter); |
178 | |
179 | /* |
180 | * Send all the processes who have the page mapped an ``action optional'' |
181 | * signal. |
182 | */ |
183 | static int kill_proc_ao(struct task_struct *t, unsigned long addr, int trapno, |
184 | unsigned long pfn) |
185 | { |
186 | struct siginfo si; |
187 | int ret; |
188 | |
189 | printk(KERN_ERR |
190 | "MCE %#lx: Killing %s:%d early due to hardware memory corruption\n", |
191 | pfn, t->comm, t->pid); |
192 | si.si_signo = SIGBUS; |
193 | si.si_errno = 0; |
194 | si.si_code = BUS_MCEERR_AO; |
195 | si.si_addr = (void *)addr; |
196 | #ifdef __ARCH_SI_TRAPNO |
197 | si.si_trapno = trapno; |
198 | #endif |
199 | si.si_addr_lsb = PAGE_SHIFT; |
200 | /* |
201 | * Don't use force here, it's convenient if the signal |
202 | * can be temporarily blocked. |
203 | * This could cause a loop when the user sets SIGBUS |
204 | * to SIG_IGN, but hopefully noone will do that? |
205 | */ |
206 | ret = send_sig_info(SIGBUS, &si, t); /* synchronous? */ |
207 | if (ret < 0) |
208 | printk(KERN_INFO "MCE: Error sending signal to %s:%d: %d\n", |
209 | t->comm, t->pid, ret); |
210 | return ret; |
211 | } |
212 | |
213 | /* |
214 | * When a unknown page type is encountered drain as many buffers as possible |
215 | * in the hope to turn the page into a LRU or free page, which we can handle. |
216 | */ |
217 | void shake_page(struct page *p, int access) |
218 | { |
219 | if (!PageSlab(p)) { |
220 | lru_add_drain_all(); |
221 | if (PageLRU(p)) |
222 | return; |
223 | drain_all_pages(); |
224 | if (PageLRU(p) || is_free_buddy_page(p)) |
225 | return; |
226 | } |
227 | |
228 | /* |
229 | * Only all shrink_slab here (which would also |
230 | * shrink other caches) if access is not potentially fatal. |
231 | */ |
232 | if (access) { |
233 | int nr; |
234 | do { |
235 | nr = shrink_slab(1000, GFP_KERNEL, 1000); |
236 | if (page_count(p) == 0) |
237 | break; |
238 | } while (nr > 10); |
239 | } |
240 | } |
241 | EXPORT_SYMBOL_GPL(shake_page); |
242 | |
243 | /* |
244 | * Kill all processes that have a poisoned page mapped and then isolate |
245 | * the page. |
246 | * |
247 | * General strategy: |
248 | * Find all processes having the page mapped and kill them. |
249 | * But we keep a page reference around so that the page is not |
250 | * actually freed yet. |
251 | * Then stash the page away |
252 | * |
253 | * There's no convenient way to get back to mapped processes |
254 | * from the VMAs. So do a brute-force search over all |
255 | * running processes. |
256 | * |
257 | * Remember that machine checks are not common (or rather |
258 | * if they are common you have other problems), so this shouldn't |
259 | * be a performance issue. |
260 | * |
261 | * Also there are some races possible while we get from the |
262 | * error detection to actually handle it. |
263 | */ |
264 | |
265 | struct to_kill { |
266 | struct list_head nd; |
267 | struct task_struct *tsk; |
268 | unsigned long addr; |
269 | unsigned addr_valid:1; |
270 | }; |
271 | |
272 | /* |
273 | * Failure handling: if we can't find or can't kill a process there's |
274 | * not much we can do. We just print a message and ignore otherwise. |
275 | */ |
276 | |
277 | /* |
278 | * Schedule a process for later kill. |
279 | * Uses GFP_ATOMIC allocations to avoid potential recursions in the VM. |
280 | * TBD would GFP_NOIO be enough? |
281 | */ |
282 | static void add_to_kill(struct task_struct *tsk, struct page *p, |
283 | struct vm_area_struct *vma, |
284 | struct list_head *to_kill, |
285 | struct to_kill **tkc) |
286 | { |
287 | struct to_kill *tk; |
288 | |
289 | if (*tkc) { |
290 | tk = *tkc; |
291 | *tkc = NULL; |
292 | } else { |
293 | tk = kmalloc(sizeof(struct to_kill), GFP_ATOMIC); |
294 | if (!tk) { |
295 | printk(KERN_ERR |
296 | "MCE: Out of memory while machine check handling\n"); |
297 | return; |
298 | } |
299 | } |
300 | tk->addr = page_address_in_vma(p, vma); |
301 | tk->addr_valid = 1; |
302 | |
303 | /* |
304 | * In theory we don't have to kill when the page was |
305 | * munmaped. But it could be also a mremap. Since that's |
306 | * likely very rare kill anyways just out of paranoia, but use |
307 | * a SIGKILL because the error is not contained anymore. |
308 | */ |
309 | if (tk->addr == -EFAULT) { |
310 | pr_debug("MCE: Unable to find user space address %lx in %s\n", |
311 | page_to_pfn(p), tsk->comm); |
312 | tk->addr_valid = 0; |
313 | } |
314 | get_task_struct(tsk); |
315 | tk->tsk = tsk; |
316 | list_add_tail(&tk->nd, to_kill); |
317 | } |
318 | |
319 | /* |
320 | * Kill the processes that have been collected earlier. |
321 | * |
322 | * Only do anything when DOIT is set, otherwise just free the list |
323 | * (this is used for clean pages which do not need killing) |
324 | * Also when FAIL is set do a force kill because something went |
325 | * wrong earlier. |
326 | */ |
327 | static void kill_procs_ao(struct list_head *to_kill, int doit, int trapno, |
328 | int fail, unsigned long pfn) |
329 | { |
330 | struct to_kill *tk, *next; |
331 | |
332 | list_for_each_entry_safe (tk, next, to_kill, nd) { |
333 | if (doit) { |
334 | /* |
335 | * In case something went wrong with munmapping |
336 | * make sure the process doesn't catch the |
337 | * signal and then access the memory. Just kill it. |
338 | */ |
339 | if (fail || tk->addr_valid == 0) { |
340 | printk(KERN_ERR |
341 | "MCE %#lx: forcibly killing %s:%d because of failure to unmap corrupted page\n", |
342 | pfn, tk->tsk->comm, tk->tsk->pid); |
343 | force_sig(SIGKILL, tk->tsk); |
344 | } |
345 | |
346 | /* |
347 | * In theory the process could have mapped |
348 | * something else on the address in-between. We could |
349 | * check for that, but we need to tell the |
350 | * process anyways. |
351 | */ |
352 | else if (kill_proc_ao(tk->tsk, tk->addr, trapno, |
353 | pfn) < 0) |
354 | printk(KERN_ERR |
355 | "MCE %#lx: Cannot send advisory machine check signal to %s:%d\n", |
356 | pfn, tk->tsk->comm, tk->tsk->pid); |
357 | } |
358 | put_task_struct(tk->tsk); |
359 | kfree(tk); |
360 | } |
361 | } |
362 | |
363 | static int task_early_kill(struct task_struct *tsk) |
364 | { |
365 | if (!tsk->mm) |
366 | return 0; |
367 | if (tsk->flags & PF_MCE_PROCESS) |
368 | return !!(tsk->flags & PF_MCE_EARLY); |
369 | return sysctl_memory_failure_early_kill; |
370 | } |
371 | |
372 | /* |
373 | * Collect processes when the error hit an anonymous page. |
374 | */ |
375 | static void collect_procs_anon(struct page *page, struct list_head *to_kill, |
376 | struct to_kill **tkc) |
377 | { |
378 | struct vm_area_struct *vma; |
379 | struct task_struct *tsk; |
380 | struct anon_vma *av; |
381 | |
382 | read_lock(&tasklist_lock); |
383 | av = page_lock_anon_vma(page); |
384 | if (av == NULL) /* Not actually mapped anymore */ |
385 | goto out; |
386 | for_each_process (tsk) { |
387 | struct anon_vma_chain *vmac; |
388 | |
389 | if (!task_early_kill(tsk)) |
390 | continue; |
391 | list_for_each_entry(vmac, &av->head, same_anon_vma) { |
392 | vma = vmac->vma; |
393 | if (!page_mapped_in_vma(page, vma)) |
394 | continue; |
395 | if (vma->vm_mm == tsk->mm) |
396 | add_to_kill(tsk, page, vma, to_kill, tkc); |
397 | } |
398 | } |
399 | page_unlock_anon_vma(av); |
400 | out: |
401 | read_unlock(&tasklist_lock); |
402 | } |
403 | |
404 | /* |
405 | * Collect processes when the error hit a file mapped page. |
406 | */ |
407 | static void collect_procs_file(struct page *page, struct list_head *to_kill, |
408 | struct to_kill **tkc) |
409 | { |
410 | struct vm_area_struct *vma; |
411 | struct task_struct *tsk; |
412 | struct prio_tree_iter iter; |
413 | struct address_space *mapping = page->mapping; |
414 | |
415 | /* |
416 | * A note on the locking order between the two locks. |
417 | * We don't rely on this particular order. |
418 | * If you have some other code that needs a different order |
419 | * feel free to switch them around. Or add a reverse link |
420 | * from mm_struct to task_struct, then this could be all |
421 | * done without taking tasklist_lock and looping over all tasks. |
422 | */ |
423 | |
424 | read_lock(&tasklist_lock); |
425 | spin_lock(&mapping->i_mmap_lock); |
426 | for_each_process(tsk) { |
427 | pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT); |
428 | |
429 | if (!task_early_kill(tsk)) |
430 | continue; |
431 | |
432 | vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, pgoff, |
433 | pgoff) { |
434 | /* |
435 | * Send early kill signal to tasks where a vma covers |
436 | * the page but the corrupted page is not necessarily |
437 | * mapped it in its pte. |
438 | * Assume applications who requested early kill want |
439 | * to be informed of all such data corruptions. |
440 | */ |
441 | if (vma->vm_mm == tsk->mm) |
442 | add_to_kill(tsk, page, vma, to_kill, tkc); |
443 | } |
444 | } |
445 | spin_unlock(&mapping->i_mmap_lock); |
446 | read_unlock(&tasklist_lock); |
447 | } |
448 | |
449 | /* |
450 | * Collect the processes who have the corrupted page mapped to kill. |
451 | * This is done in two steps for locking reasons. |
452 | * First preallocate one tokill structure outside the spin locks, |
453 | * so that we can kill at least one process reasonably reliable. |
454 | */ |
455 | static void collect_procs(struct page *page, struct list_head *tokill) |
456 | { |
457 | struct to_kill *tk; |
458 | |
459 | if (!page->mapping) |
460 | return; |
461 | |
462 | tk = kmalloc(sizeof(struct to_kill), GFP_NOIO); |
463 | if (!tk) |
464 | return; |
465 | if (PageAnon(page)) |
466 | collect_procs_anon(page, tokill, &tk); |
467 | else |
468 | collect_procs_file(page, tokill, &tk); |
469 | kfree(tk); |
470 | } |
471 | |
472 | /* |
473 | * Error handlers for various types of pages. |
474 | */ |
475 | |
476 | enum outcome { |
477 | IGNORED, /* Error: cannot be handled */ |
478 | FAILED, /* Error: handling failed */ |
479 | DELAYED, /* Will be handled later */ |
480 | RECOVERED, /* Successfully recovered */ |
481 | }; |
482 | |
483 | static const char *action_name[] = { |
484 | [IGNORED] = "Ignored", |
485 | [FAILED] = "Failed", |
486 | [DELAYED] = "Delayed", |
487 | [RECOVERED] = "Recovered", |
488 | }; |
489 | |
490 | /* |
491 | * XXX: It is possible that a page is isolated from LRU cache, |
492 | * and then kept in swap cache or failed to remove from page cache. |
493 | * The page count will stop it from being freed by unpoison. |
494 | * Stress tests should be aware of this memory leak problem. |
495 | */ |
496 | static int delete_from_lru_cache(struct page *p) |
497 | { |
498 | if (!isolate_lru_page(p)) { |
499 | /* |
500 | * Clear sensible page flags, so that the buddy system won't |
501 | * complain when the page is unpoison-and-freed. |
502 | */ |
503 | ClearPageActive(p); |
504 | ClearPageUnevictable(p); |
505 | /* |
506 | * drop the page count elevated by isolate_lru_page() |
507 | */ |
508 | page_cache_release(p); |
509 | return 0; |
510 | } |
511 | return -EIO; |
512 | } |
513 | |
514 | /* |
515 | * Error hit kernel page. |
516 | * Do nothing, try to be lucky and not touch this instead. For a few cases we |
517 | * could be more sophisticated. |
518 | */ |
519 | static int me_kernel(struct page *p, unsigned long pfn) |
520 | { |
521 | return IGNORED; |
522 | } |
523 | |
524 | /* |
525 | * Page in unknown state. Do nothing. |
526 | */ |
527 | static int me_unknown(struct page *p, unsigned long pfn) |
528 | { |
529 | printk(KERN_ERR "MCE %#lx: Unknown page state\n", pfn); |
530 | return FAILED; |
531 | } |
532 | |
533 | /* |
534 | * Clean (or cleaned) page cache page. |
535 | */ |
536 | static int me_pagecache_clean(struct page *p, unsigned long pfn) |
537 | { |
538 | int err; |
539 | int ret = FAILED; |
540 | struct address_space *mapping; |
541 | |
542 | delete_from_lru_cache(p); |
543 | |
544 | /* |
545 | * For anonymous pages we're done the only reference left |
546 | * should be the one m_f() holds. |
547 | */ |
548 | if (PageAnon(p)) |
549 | return RECOVERED; |
550 | |
551 | /* |
552 | * Now truncate the page in the page cache. This is really |
553 | * more like a "temporary hole punch" |
554 | * Don't do this for block devices when someone else |
555 | * has a reference, because it could be file system metadata |
556 | * and that's not safe to truncate. |
557 | */ |
558 | mapping = page_mapping(p); |
559 | if (!mapping) { |
560 | /* |
561 | * Page has been teared down in the meanwhile |
562 | */ |
563 | return FAILED; |
564 | } |
565 | |
566 | /* |
567 | * Truncation is a bit tricky. Enable it per file system for now. |
568 | * |
569 | * Open: to take i_mutex or not for this? Right now we don't. |
570 | */ |
571 | if (mapping->a_ops->error_remove_page) { |
572 | err = mapping->a_ops->error_remove_page(mapping, p); |
573 | if (err != 0) { |
574 | printk(KERN_INFO "MCE %#lx: Failed to punch page: %d\n", |
575 | pfn, err); |
576 | } else if (page_has_private(p) && |
577 | !try_to_release_page(p, GFP_NOIO)) { |
578 | pr_debug("MCE %#lx: failed to release buffers\n", pfn); |
579 | } else { |
580 | ret = RECOVERED; |
581 | } |
582 | } else { |
583 | /* |
584 | * If the file system doesn't support it just invalidate |
585 | * This fails on dirty or anything with private pages |
586 | */ |
587 | if (invalidate_inode_page(p)) |
588 | ret = RECOVERED; |
589 | else |
590 | printk(KERN_INFO "MCE %#lx: Failed to invalidate\n", |
591 | pfn); |
592 | } |
593 | return ret; |
594 | } |
595 | |
596 | /* |
597 | * Dirty cache page page |
598 | * Issues: when the error hit a hole page the error is not properly |
599 | * propagated. |
600 | */ |
601 | static int me_pagecache_dirty(struct page *p, unsigned long pfn) |
602 | { |
603 | struct address_space *mapping = page_mapping(p); |
604 | |
605 | SetPageError(p); |
606 | /* TBD: print more information about the file. */ |
607 | if (mapping) { |
608 | /* |
609 | * IO error will be reported by write(), fsync(), etc. |
610 | * who check the mapping. |
611 | * This way the application knows that something went |
612 | * wrong with its dirty file data. |
613 | * |
614 | * There's one open issue: |
615 | * |
616 | * The EIO will be only reported on the next IO |
617 | * operation and then cleared through the IO map. |
618 | * Normally Linux has two mechanisms to pass IO error |
619 | * first through the AS_EIO flag in the address space |
620 | * and then through the PageError flag in the page. |
621 | * Since we drop pages on memory failure handling the |
622 | * only mechanism open to use is through AS_AIO. |
623 | * |
624 | * This has the disadvantage that it gets cleared on |
625 | * the first operation that returns an error, while |
626 | * the PageError bit is more sticky and only cleared |
627 | * when the page is reread or dropped. If an |
628 | * application assumes it will always get error on |
629 | * fsync, but does other operations on the fd before |
630 | * and the page is dropped inbetween then the error |
631 | * will not be properly reported. |
632 | * |
633 | * This can already happen even without hwpoisoned |
634 | * pages: first on metadata IO errors (which only |
635 | * report through AS_EIO) or when the page is dropped |
636 | * at the wrong time. |
637 | * |
638 | * So right now we assume that the application DTRT on |
639 | * the first EIO, but we're not worse than other parts |
640 | * of the kernel. |
641 | */ |
642 | mapping_set_error(mapping, EIO); |
643 | } |
644 | |
645 | return me_pagecache_clean(p, pfn); |
646 | } |
647 | |
648 | /* |
649 | * Clean and dirty swap cache. |
650 | * |
651 | * Dirty swap cache page is tricky to handle. The page could live both in page |
652 | * cache and swap cache(ie. page is freshly swapped in). So it could be |
653 | * referenced concurrently by 2 types of PTEs: |
654 | * normal PTEs and swap PTEs. We try to handle them consistently by calling |
655 | * try_to_unmap(TTU_IGNORE_HWPOISON) to convert the normal PTEs to swap PTEs, |
656 | * and then |
657 | * - clear dirty bit to prevent IO |
658 | * - remove from LRU |
659 | * - but keep in the swap cache, so that when we return to it on |
660 | * a later page fault, we know the application is accessing |
661 | * corrupted data and shall be killed (we installed simple |
662 | * interception code in do_swap_page to catch it). |
663 | * |
664 | * Clean swap cache pages can be directly isolated. A later page fault will |
665 | * bring in the known good data from disk. |
666 | */ |
667 | static int me_swapcache_dirty(struct page *p, unsigned long pfn) |
668 | { |
669 | ClearPageDirty(p); |
670 | /* Trigger EIO in shmem: */ |
671 | ClearPageUptodate(p); |
672 | |
673 | if (!delete_from_lru_cache(p)) |
674 | return DELAYED; |
675 | else |
676 | return FAILED; |
677 | } |
678 | |
679 | static int me_swapcache_clean(struct page *p, unsigned long pfn) |
680 | { |
681 | delete_from_swap_cache(p); |
682 | |
683 | if (!delete_from_lru_cache(p)) |
684 | return RECOVERED; |
685 | else |
686 | return FAILED; |
687 | } |
688 | |
689 | /* |
690 | * Huge pages. Needs work. |
691 | * Issues: |
692 | * No rmap support so we cannot find the original mapper. In theory could walk |
693 | * all MMs and look for the mappings, but that would be non atomic and racy. |
694 | * Need rmap for hugepages for this. Alternatively we could employ a heuristic, |
695 | * like just walking the current process and hoping it has it mapped (that |
696 | * should be usually true for the common "shared database cache" case) |
697 | * Should handle free huge pages and dequeue them too, but this needs to |
698 | * handle huge page accounting correctly. |
699 | */ |
700 | static int me_huge_page(struct page *p, unsigned long pfn) |
701 | { |
702 | return FAILED; |
703 | } |
704 | |
705 | /* |
706 | * Various page states we can handle. |
707 | * |
708 | * A page state is defined by its current page->flags bits. |
709 | * The table matches them in order and calls the right handler. |
710 | * |
711 | * This is quite tricky because we can access page at any time |
712 | * in its live cycle, so all accesses have to be extremly careful. |
713 | * |
714 | * This is not complete. More states could be added. |
715 | * For any missing state don't attempt recovery. |
716 | */ |
717 | |
718 | #define dirty (1UL << PG_dirty) |
719 | #define sc (1UL << PG_swapcache) |
720 | #define unevict (1UL << PG_unevictable) |
721 | #define mlock (1UL << PG_mlocked) |
722 | #define writeback (1UL << PG_writeback) |
723 | #define lru (1UL << PG_lru) |
724 | #define swapbacked (1UL << PG_swapbacked) |
725 | #define head (1UL << PG_head) |
726 | #define tail (1UL << PG_tail) |
727 | #define compound (1UL << PG_compound) |
728 | #define slab (1UL << PG_slab) |
729 | #define reserved (1UL << PG_reserved) |
730 | |
731 | static struct page_state { |
732 | unsigned long mask; |
733 | unsigned long res; |
734 | char *msg; |
735 | int (*action)(struct page *p, unsigned long pfn); |
736 | } error_states[] = { |
737 | { reserved, reserved, "reserved kernel", me_kernel }, |
738 | /* |
739 | * free pages are specially detected outside this table: |
740 | * PG_buddy pages only make a small fraction of all free pages. |
741 | */ |
742 | |
743 | /* |
744 | * Could in theory check if slab page is free or if we can drop |
745 | * currently unused objects without touching them. But just |
746 | * treat it as standard kernel for now. |
747 | */ |
748 | { slab, slab, "kernel slab", me_kernel }, |
749 | |
750 | #ifdef CONFIG_PAGEFLAGS_EXTENDED |
751 | { head, head, "huge", me_huge_page }, |
752 | { tail, tail, "huge", me_huge_page }, |
753 | #else |
754 | { compound, compound, "huge", me_huge_page }, |
755 | #endif |
756 | |
757 | { sc|dirty, sc|dirty, "swapcache", me_swapcache_dirty }, |
758 | { sc|dirty, sc, "swapcache", me_swapcache_clean }, |
759 | |
760 | { unevict|dirty, unevict|dirty, "unevictable LRU", me_pagecache_dirty}, |
761 | { unevict, unevict, "unevictable LRU", me_pagecache_clean}, |
762 | |
763 | { mlock|dirty, mlock|dirty, "mlocked LRU", me_pagecache_dirty }, |
764 | { mlock, mlock, "mlocked LRU", me_pagecache_clean }, |
765 | |
766 | { lru|dirty, lru|dirty, "LRU", me_pagecache_dirty }, |
767 | { lru|dirty, lru, "clean LRU", me_pagecache_clean }, |
768 | |
769 | /* |
770 | * Catchall entry: must be at end. |
771 | */ |
772 | { 0, 0, "unknown page state", me_unknown }, |
773 | }; |
774 | |
775 | #undef dirty |
776 | #undef sc |
777 | #undef unevict |
778 | #undef mlock |
779 | #undef writeback |
780 | #undef lru |
781 | #undef swapbacked |
782 | #undef head |
783 | #undef tail |
784 | #undef compound |
785 | #undef slab |
786 | #undef reserved |
787 | |
788 | static void action_result(unsigned long pfn, char *msg, int result) |
789 | { |
790 | struct page *page = pfn_to_page(pfn); |
791 | |
792 | printk(KERN_ERR "MCE %#lx: %s%s page recovery: %s\n", |
793 | pfn, |
794 | PageDirty(page) ? "dirty " : "", |
795 | msg, action_name[result]); |
796 | } |
797 | |
798 | static int page_action(struct page_state *ps, struct page *p, |
799 | unsigned long pfn) |
800 | { |
801 | int result; |
802 | int count; |
803 | |
804 | result = ps->action(p, pfn); |
805 | action_result(pfn, ps->msg, result); |
806 | |
807 | count = page_count(p) - 1; |
808 | if (ps->action == me_swapcache_dirty && result == DELAYED) |
809 | count--; |
810 | if (count != 0) { |
811 | printk(KERN_ERR |
812 | "MCE %#lx: %s page still referenced by %d users\n", |
813 | pfn, ps->msg, count); |
814 | result = FAILED; |
815 | } |
816 | |
817 | /* Could do more checks here if page looks ok */ |
818 | /* |
819 | * Could adjust zone counters here to correct for the missing page. |
820 | */ |
821 | |
822 | return (result == RECOVERED || result == DELAYED) ? 0 : -EBUSY; |
823 | } |
824 | |
825 | #define N_UNMAP_TRIES 5 |
826 | |
827 | /* |
828 | * Do all that is necessary to remove user space mappings. Unmap |
829 | * the pages and send SIGBUS to the processes if the data was dirty. |
830 | */ |
831 | static int hwpoison_user_mappings(struct page *p, unsigned long pfn, |
832 | int trapno) |
833 | { |
834 | enum ttu_flags ttu = TTU_UNMAP | TTU_IGNORE_MLOCK | TTU_IGNORE_ACCESS; |
835 | struct address_space *mapping; |
836 | LIST_HEAD(tokill); |
837 | int ret; |
838 | int i; |
839 | int kill = 1; |
840 | |
841 | if (PageReserved(p) || PageSlab(p)) |
842 | return SWAP_SUCCESS; |
843 | |
844 | /* |
845 | * This check implies we don't kill processes if their pages |
846 | * are in the swap cache early. Those are always late kills. |
847 | */ |
848 | if (!page_mapped(p)) |
849 | return SWAP_SUCCESS; |
850 | |
851 | if (PageCompound(p) || PageKsm(p)) |
852 | return SWAP_FAIL; |
853 | |
854 | if (PageSwapCache(p)) { |
855 | printk(KERN_ERR |
856 | "MCE %#lx: keeping poisoned page in swap cache\n", pfn); |
857 | ttu |= TTU_IGNORE_HWPOISON; |
858 | } |
859 | |
860 | /* |
861 | * Propagate the dirty bit from PTEs to struct page first, because we |
862 | * need this to decide if we should kill or just drop the page. |
863 | * XXX: the dirty test could be racy: set_page_dirty() may not always |
864 | * be called inside page lock (it's recommended but not enforced). |
865 | */ |
866 | mapping = page_mapping(p); |
867 | if (!PageDirty(p) && mapping && mapping_cap_writeback_dirty(mapping)) { |
868 | if (page_mkclean(p)) { |
869 | SetPageDirty(p); |
870 | } else { |
871 | kill = 0; |
872 | ttu |= TTU_IGNORE_HWPOISON; |
873 | printk(KERN_INFO |
874 | "MCE %#lx: corrupted page was clean: dropped without side effects\n", |
875 | pfn); |
876 | } |
877 | } |
878 | |
879 | /* |
880 | * First collect all the processes that have the page |
881 | * mapped in dirty form. This has to be done before try_to_unmap, |
882 | * because ttu takes the rmap data structures down. |
883 | * |
884 | * Error handling: We ignore errors here because |
885 | * there's nothing that can be done. |
886 | */ |
887 | if (kill) |
888 | collect_procs(p, &tokill); |
889 | |
890 | /* |
891 | * try_to_unmap can fail temporarily due to races. |
892 | * Try a few times (RED-PEN better strategy?) |
893 | */ |
894 | for (i = 0; i < N_UNMAP_TRIES; i++) { |
895 | ret = try_to_unmap(p, ttu); |
896 | if (ret == SWAP_SUCCESS) |
897 | break; |
898 | pr_debug("MCE %#lx: try_to_unmap retry needed %d\n", pfn, ret); |
899 | } |
900 | |
901 | if (ret != SWAP_SUCCESS) |
902 | printk(KERN_ERR "MCE %#lx: failed to unmap page (mapcount=%d)\n", |
903 | pfn, page_mapcount(p)); |
904 | |
905 | /* |
906 | * Now that the dirty bit has been propagated to the |
907 | * struct page and all unmaps done we can decide if |
908 | * killing is needed or not. Only kill when the page |
909 | * was dirty, otherwise the tokill list is merely |
910 | * freed. When there was a problem unmapping earlier |
911 | * use a more force-full uncatchable kill to prevent |
912 | * any accesses to the poisoned memory. |
913 | */ |
914 | kill_procs_ao(&tokill, !!PageDirty(p), trapno, |
915 | ret != SWAP_SUCCESS, pfn); |
916 | |
917 | return ret; |
918 | } |
919 | |
920 | int __memory_failure(unsigned long pfn, int trapno, int flags) |
921 | { |
922 | struct page_state *ps; |
923 | struct page *p; |
924 | int res; |
925 | |
926 | if (!sysctl_memory_failure_recovery) |
927 | panic("Memory failure from trap %d on page %lx", trapno, pfn); |
928 | |
929 | if (!pfn_valid(pfn)) { |
930 | printk(KERN_ERR |
931 | "MCE %#lx: memory outside kernel control\n", |
932 | pfn); |
933 | return -ENXIO; |
934 | } |
935 | |
936 | p = pfn_to_page(pfn); |
937 | if (TestSetPageHWPoison(p)) { |
938 | printk(KERN_ERR "MCE %#lx: already hardware poisoned\n", pfn); |
939 | return 0; |
940 | } |
941 | |
942 | atomic_long_add(1, &mce_bad_pages); |
943 | |
944 | /* |
945 | * We need/can do nothing about count=0 pages. |
946 | * 1) it's a free page, and therefore in safe hand: |
947 | * prep_new_page() will be the gate keeper. |
948 | * 2) it's part of a non-compound high order page. |
949 | * Implies some kernel user: cannot stop them from |
950 | * R/W the page; let's pray that the page has been |
951 | * used and will be freed some time later. |
952 | * In fact it's dangerous to directly bump up page count from 0, |
953 | * that may make page_freeze_refs()/page_unfreeze_refs() mismatch. |
954 | */ |
955 | if (!(flags & MF_COUNT_INCREASED) && |
956 | !get_page_unless_zero(compound_head(p))) { |
957 | if (is_free_buddy_page(p)) { |
958 | action_result(pfn, "free buddy", DELAYED); |
959 | return 0; |
960 | } else { |
961 | action_result(pfn, "high order kernel", IGNORED); |
962 | return -EBUSY; |
963 | } |
964 | } |
965 | |
966 | /* |
967 | * We ignore non-LRU pages for good reasons. |
968 | * - PG_locked is only well defined for LRU pages and a few others |
969 | * - to avoid races with __set_page_locked() |
970 | * - to avoid races with __SetPageSlab*() (and more non-atomic ops) |
971 | * The check (unnecessarily) ignores LRU pages being isolated and |
972 | * walked by the page reclaim code, however that's not a big loss. |
973 | */ |
974 | if (!PageLRU(p)) |
975 | shake_page(p, 0); |
976 | if (!PageLRU(p)) { |
977 | /* |
978 | * shake_page could have turned it free. |
979 | */ |
980 | if (is_free_buddy_page(p)) { |
981 | action_result(pfn, "free buddy, 2nd try", DELAYED); |
982 | return 0; |
983 | } |
984 | action_result(pfn, "non LRU", IGNORED); |
985 | put_page(p); |
986 | return -EBUSY; |
987 | } |
988 | |
989 | /* |
990 | * Lock the page and wait for writeback to finish. |
991 | * It's very difficult to mess with pages currently under IO |
992 | * and in many cases impossible, so we just avoid it here. |
993 | */ |
994 | lock_page_nosync(p); |
995 | |
996 | /* |
997 | * unpoison always clear PG_hwpoison inside page lock |
998 | */ |
999 | if (!PageHWPoison(p)) { |
1000 | printk(KERN_ERR "MCE %#lx: just unpoisoned\n", pfn); |
1001 | res = 0; |
1002 | goto out; |
1003 | } |
1004 | if (hwpoison_filter(p)) { |
1005 | if (TestClearPageHWPoison(p)) |
1006 | atomic_long_dec(&mce_bad_pages); |
1007 | unlock_page(p); |
1008 | put_page(p); |
1009 | return 0; |
1010 | } |
1011 | |
1012 | wait_on_page_writeback(p); |
1013 | |
1014 | /* |
1015 | * Now take care of user space mappings. |
1016 | * Abort on fail: __remove_from_page_cache() assumes unmapped page. |
1017 | */ |
1018 | if (hwpoison_user_mappings(p, pfn, trapno) != SWAP_SUCCESS) { |
1019 | printk(KERN_ERR "MCE %#lx: cannot unmap page, give up\n", pfn); |
1020 | res = -EBUSY; |
1021 | goto out; |
1022 | } |
1023 | |
1024 | /* |
1025 | * Torn down by someone else? |
1026 | */ |
1027 | if (PageLRU(p) && !PageSwapCache(p) && p->mapping == NULL) { |
1028 | action_result(pfn, "already truncated LRU", IGNORED); |
1029 | res = -EBUSY; |
1030 | goto out; |
1031 | } |
1032 | |
1033 | res = -EBUSY; |
1034 | for (ps = error_states;; ps++) { |
1035 | if ((p->flags & ps->mask) == ps->res) { |
1036 | res = page_action(ps, p, pfn); |
1037 | break; |
1038 | } |
1039 | } |
1040 | out: |
1041 | unlock_page(p); |
1042 | return res; |
1043 | } |
1044 | EXPORT_SYMBOL_GPL(__memory_failure); |
1045 | |
1046 | /** |
1047 | * memory_failure - Handle memory failure of a page. |
1048 | * @pfn: Page Number of the corrupted page |
1049 | * @trapno: Trap number reported in the signal to user space. |
1050 | * |
1051 | * This function is called by the low level machine check code |
1052 | * of an architecture when it detects hardware memory corruption |
1053 | * of a page. It tries its best to recover, which includes |
1054 | * dropping pages, killing processes etc. |
1055 | * |
1056 | * The function is primarily of use for corruptions that |
1057 | * happen outside the current execution context (e.g. when |
1058 | * detected by a background scrubber) |
1059 | * |
1060 | * Must run in process context (e.g. a work queue) with interrupts |
1061 | * enabled and no spinlocks hold. |
1062 | */ |
1063 | void memory_failure(unsigned long pfn, int trapno) |
1064 | { |
1065 | __memory_failure(pfn, trapno, 0); |
1066 | } |
1067 | |
1068 | /** |
1069 | * unpoison_memory - Unpoison a previously poisoned page |
1070 | * @pfn: Page number of the to be unpoisoned page |
1071 | * |
1072 | * Software-unpoison a page that has been poisoned by |
1073 | * memory_failure() earlier. |
1074 | * |
1075 | * This is only done on the software-level, so it only works |
1076 | * for linux injected failures, not real hardware failures |
1077 | * |
1078 | * Returns 0 for success, otherwise -errno. |
1079 | */ |
1080 | int unpoison_memory(unsigned long pfn) |
1081 | { |
1082 | struct page *page; |
1083 | struct page *p; |
1084 | int freeit = 0; |
1085 | |
1086 | if (!pfn_valid(pfn)) |
1087 | return -ENXIO; |
1088 | |
1089 | p = pfn_to_page(pfn); |
1090 | page = compound_head(p); |
1091 | |
1092 | if (!PageHWPoison(p)) { |
1093 | pr_debug("MCE: Page was already unpoisoned %#lx\n", pfn); |
1094 | return 0; |
1095 | } |
1096 | |
1097 | if (!get_page_unless_zero(page)) { |
1098 | if (TestClearPageHWPoison(p)) |
1099 | atomic_long_dec(&mce_bad_pages); |
1100 | pr_debug("MCE: Software-unpoisoned free page %#lx\n", pfn); |
1101 | return 0; |
1102 | } |
1103 | |
1104 | lock_page_nosync(page); |
1105 | /* |
1106 | * This test is racy because PG_hwpoison is set outside of page lock. |
1107 | * That's acceptable because that won't trigger kernel panic. Instead, |
1108 | * the PG_hwpoison page will be caught and isolated on the entrance to |
1109 | * the free buddy page pool. |
1110 | */ |
1111 | if (TestClearPageHWPoison(p)) { |
1112 | pr_debug("MCE: Software-unpoisoned page %#lx\n", pfn); |
1113 | atomic_long_dec(&mce_bad_pages); |
1114 | freeit = 1; |
1115 | } |
1116 | unlock_page(page); |
1117 | |
1118 | put_page(page); |
1119 | if (freeit) |
1120 | put_page(page); |
1121 | |
1122 | return 0; |
1123 | } |
1124 | EXPORT_SYMBOL(unpoison_memory); |
1125 | |
1126 | static struct page *new_page(struct page *p, unsigned long private, int **x) |
1127 | { |
1128 | int nid = page_to_nid(p); |
1129 | return alloc_pages_exact_node(nid, GFP_HIGHUSER_MOVABLE, 0); |
1130 | } |
1131 | |
1132 | /* |
1133 | * Safely get reference count of an arbitrary page. |
1134 | * Returns 0 for a free page, -EIO for a zero refcount page |
1135 | * that is not free, and 1 for any other page type. |
1136 | * For 1 the page is returned with increased page count, otherwise not. |
1137 | */ |
1138 | static int get_any_page(struct page *p, unsigned long pfn, int flags) |
1139 | { |
1140 | int ret; |
1141 | |
1142 | if (flags & MF_COUNT_INCREASED) |
1143 | return 1; |
1144 | |
1145 | /* |
1146 | * The lock_system_sleep prevents a race with memory hotplug, |
1147 | * because the isolation assumes there's only a single user. |
1148 | * This is a big hammer, a better would be nicer. |
1149 | */ |
1150 | lock_system_sleep(); |
1151 | |
1152 | /* |
1153 | * Isolate the page, so that it doesn't get reallocated if it |
1154 | * was free. |
1155 | */ |
1156 | set_migratetype_isolate(p); |
1157 | if (!get_page_unless_zero(compound_head(p))) { |
1158 | if (is_free_buddy_page(p)) { |
1159 | pr_debug("get_any_page: %#lx free buddy page\n", pfn); |
1160 | /* Set hwpoison bit while page is still isolated */ |
1161 | SetPageHWPoison(p); |
1162 | ret = 0; |
1163 | } else { |
1164 | pr_debug("get_any_page: %#lx: unknown zero refcount page type %lx\n", |
1165 | pfn, p->flags); |
1166 | ret = -EIO; |
1167 | } |
1168 | } else { |
1169 | /* Not a free page */ |
1170 | ret = 1; |
1171 | } |
1172 | unset_migratetype_isolate(p); |
1173 | unlock_system_sleep(); |
1174 | return ret; |
1175 | } |
1176 | |
1177 | /** |
1178 | * soft_offline_page - Soft offline a page. |
1179 | * @page: page to offline |
1180 | * @flags: flags. Same as memory_failure(). |
1181 | * |
1182 | * Returns 0 on success, otherwise negated errno. |
1183 | * |
1184 | * Soft offline a page, by migration or invalidation, |
1185 | * without killing anything. This is for the case when |
1186 | * a page is not corrupted yet (so it's still valid to access), |
1187 | * but has had a number of corrected errors and is better taken |
1188 | * out. |
1189 | * |
1190 | * The actual policy on when to do that is maintained by |
1191 | * user space. |
1192 | * |
1193 | * This should never impact any application or cause data loss, |
1194 | * however it might take some time. |
1195 | * |
1196 | * This is not a 100% solution for all memory, but tries to be |
1197 | * ``good enough'' for the majority of memory. |
1198 | */ |
1199 | int soft_offline_page(struct page *page, int flags) |
1200 | { |
1201 | int ret; |
1202 | unsigned long pfn = page_to_pfn(page); |
1203 | |
1204 | ret = get_any_page(page, pfn, flags); |
1205 | if (ret < 0) |
1206 | return ret; |
1207 | if (ret == 0) |
1208 | goto done; |
1209 | |
1210 | /* |
1211 | * Page cache page we can handle? |
1212 | */ |
1213 | if (!PageLRU(page)) { |
1214 | /* |
1215 | * Try to free it. |
1216 | */ |
1217 | put_page(page); |
1218 | shake_page(page, 1); |
1219 | |
1220 | /* |
1221 | * Did it turn free? |
1222 | */ |
1223 | ret = get_any_page(page, pfn, 0); |
1224 | if (ret < 0) |
1225 | return ret; |
1226 | if (ret == 0) |
1227 | goto done; |
1228 | } |
1229 | if (!PageLRU(page)) { |
1230 | pr_debug("soft_offline: %#lx: unknown non LRU page type %lx\n", |
1231 | pfn, page->flags); |
1232 | return -EIO; |
1233 | } |
1234 | |
1235 | lock_page(page); |
1236 | wait_on_page_writeback(page); |
1237 | |
1238 | /* |
1239 | * Synchronized using the page lock with memory_failure() |
1240 | */ |
1241 | if (PageHWPoison(page)) { |
1242 | unlock_page(page); |
1243 | put_page(page); |
1244 | pr_debug("soft offline: %#lx page already poisoned\n", pfn); |
1245 | return -EBUSY; |
1246 | } |
1247 | |
1248 | /* |
1249 | * Try to invalidate first. This should work for |
1250 | * non dirty unmapped page cache pages. |
1251 | */ |
1252 | ret = invalidate_inode_page(page); |
1253 | unlock_page(page); |
1254 | |
1255 | /* |
1256 | * Drop count because page migration doesn't like raised |
1257 | * counts. The page could get re-allocated, but if it becomes |
1258 | * LRU the isolation will just fail. |
1259 | * RED-PEN would be better to keep it isolated here, but we |
1260 | * would need to fix isolation locking first. |
1261 | */ |
1262 | put_page(page); |
1263 | if (ret == 1) { |
1264 | ret = 0; |
1265 | pr_debug("soft_offline: %#lx: invalidated\n", pfn); |
1266 | goto done; |
1267 | } |
1268 | |
1269 | /* |
1270 | * Simple invalidation didn't work. |
1271 | * Try to migrate to a new page instead. migrate.c |
1272 | * handles a large number of cases for us. |
1273 | */ |
1274 | ret = isolate_lru_page(page); |
1275 | if (!ret) { |
1276 | LIST_HEAD(pagelist); |
1277 | |
1278 | list_add(&page->lru, &pagelist); |
1279 | ret = migrate_pages(&pagelist, new_page, MPOL_MF_MOVE_ALL, 0); |
1280 | if (ret) { |
1281 | pr_debug("soft offline: %#lx: migration failed %d, type %lx\n", |
1282 | pfn, ret, page->flags); |
1283 | if (ret > 0) |
1284 | ret = -EIO; |
1285 | } |
1286 | } else { |
1287 | pr_debug("soft offline: %#lx: isolation failed: %d, page count %d, type %lx\n", |
1288 | pfn, ret, page_count(page), page->flags); |
1289 | } |
1290 | if (ret) |
1291 | return ret; |
1292 | |
1293 | done: |
1294 | atomic_long_add(1, &mce_bad_pages); |
1295 | SetPageHWPoison(page); |
1296 | /* keep elevated page count for bad page */ |
1297 | return ret; |
1298 | } |
1299 |
Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
jz-2.6.34-rc7
jz-2.6.35
jz-2.6.36
jz-2.6.37
jz-2.6.38
jz-2.6.39
jz-3.0
jz-3.1
jz-3.11
jz-3.12
jz-3.13
jz-3.15
jz-3.16
jz-3.18-dt
jz-3.2
jz-3.3
jz-3.4
jz-3.5
jz-3.6
jz-3.6-rc2-pwm
jz-3.9
jz-3.9-clk
jz-3.9-rc8
jz47xx
jz47xx-2.6.38
master
Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9