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1439f94c | 1 | // SPDX-License-Identifier: GPL-2.0-only |
6a46079c AK |
2 | /* |
3 | * Copyright (C) 2008, 2009 Intel Corporation | |
4 | * Authors: Andi Kleen, Fengguang Wu | |
5 | * | |
6a46079c | 6 | * High level machine check handler. Handles pages reported by the |
1c80b990 | 7 | * hardware as being corrupted usually due to a multi-bit ECC memory or cache |
6a46079c | 8 | * failure. |
c33c7948 | 9 | * |
1c80b990 AK |
10 | * In addition there is a "soft offline" entry point that allows stop using |
11 | * not-yet-corrupted-by-suspicious pages without killing anything. | |
6a46079c AK |
12 | * |
13 | * Handles page cache pages in various states. The tricky part | |
c33c7948 RR |
14 | * here is that we can access any page asynchronously in respect to |
15 | * other VM users, because memory failures could happen anytime and | |
16 | * anywhere. This could violate some of their assumptions. This is why | |
17 | * this code has to be extremely careful. Generally it tries to use | |
18 | * normal locking rules, as in get the standard locks, even if that means | |
1c80b990 | 19 | * the error handling takes potentially a long time. |
e0de78df AK |
20 | * |
21 | * It can be very tempting to add handling for obscure cases here. | |
22 | * In general any code for handling new cases should only be added iff: | |
23 | * - You know how to test it. | |
24 | * - You have a test that can be added to mce-test | |
25 | * https://git.kernel.org/cgit/utils/cpu/mce/mce-test.git/ | |
26 | * - The case actually shows up as a frequent (top 10) page state in | |
799fb82a | 27 | * tools/mm/page-types when running a real workload. |
c33c7948 | 28 | * |
1c80b990 | 29 | * There are several operations here with exponential complexity because |
c33c7948 RR |
30 | * of unsuitable VM data structures. For example the operation to map back |
31 | * from RMAP chains to processes has to walk the complete process list and | |
1c80b990 | 32 | * has non linear complexity with the number. But since memory corruptions |
c33c7948 | 33 | * are rare we hope to get away with this. This avoids impacting the core |
1c80b990 | 34 | * VM. |
6a46079c | 35 | */ |
96f96763 KW |
36 | |
37 | #define pr_fmt(fmt) "Memory failure: " fmt | |
38 | ||
6a46079c AK |
39 | #include <linux/kernel.h> |
40 | #include <linux/mm.h> | |
41 | #include <linux/page-flags.h> | |
3f07c014 | 42 | #include <linux/sched/signal.h> |
29930025 | 43 | #include <linux/sched/task.h> |
96c84dde | 44 | #include <linux/dax.h> |
01e00f88 | 45 | #include <linux/ksm.h> |
6a46079c | 46 | #include <linux/rmap.h> |
b9e15baf | 47 | #include <linux/export.h> |
6a46079c AK |
48 | #include <linux/pagemap.h> |
49 | #include <linux/swap.h> | |
50 | #include <linux/backing-dev.h> | |
facb6011 | 51 | #include <linux/migrate.h> |
5a0e3ad6 | 52 | #include <linux/slab.h> |
bf998156 | 53 | #include <linux/swapops.h> |
7af446a8 | 54 | #include <linux/hugetlb.h> |
20d6c96b | 55 | #include <linux/memory_hotplug.h> |
5db8a73a | 56 | #include <linux/mm_inline.h> |
6100e34b | 57 | #include <linux/memremap.h> |
ea8f5fb8 | 58 | #include <linux/kfifo.h> |
a5f65109 | 59 | #include <linux/ratelimit.h> |
a3f5d80e | 60 | #include <linux/pagewalk.h> |
a7605426 | 61 | #include <linux/shmem_fs.h> |
8cbc82f3 | 62 | #include <linux/sysctl.h> |
014bb1de | 63 | #include "swap.h" |
6a46079c | 64 | #include "internal.h" |
97f0b134 | 65 | #include "ras/ras_event.h" |
6a46079c | 66 | |
8cbc82f3 | 67 | static int sysctl_memory_failure_early_kill __read_mostly; |
6a46079c | 68 | |
8cbc82f3 | 69 | static int sysctl_memory_failure_recovery __read_mostly = 1; |
6a46079c | 70 | |
293c07e3 | 71 | atomic_long_t num_poisoned_pages __read_mostly = ATOMIC_LONG_INIT(0); |
6a46079c | 72 | |
67f22ba7 | 73 | static bool hw_memory_failure __read_mostly = false; |
74 | ||
b79f8eb4 JY |
75 | static DEFINE_MUTEX(mf_mutex); |
76 | ||
1a7d018d | 77 | void num_poisoned_pages_inc(unsigned long pfn) |
d027122d NH |
78 | { |
79 | atomic_long_inc(&num_poisoned_pages); | |
5033091d | 80 | memblk_nr_poison_inc(pfn); |
d027122d NH |
81 | } |
82 | ||
1a7d018d | 83 | void num_poisoned_pages_sub(unsigned long pfn, long i) |
d027122d NH |
84 | { |
85 | atomic_long_sub(i, &num_poisoned_pages); | |
5033091d NH |
86 | if (pfn != -1UL) |
87 | memblk_nr_poison_sub(pfn, i); | |
d027122d NH |
88 | } |
89 | ||
44b8f8bf JY |
90 | /** |
91 | * MF_ATTR_RO - Create sysfs entry for each memory failure statistics. | |
92 | * @_name: name of the file in the per NUMA sysfs directory. | |
93 | */ | |
94 | #define MF_ATTR_RO(_name) \ | |
95 | static ssize_t _name##_show(struct device *dev, \ | |
96 | struct device_attribute *attr, \ | |
97 | char *buf) \ | |
98 | { \ | |
99 | struct memory_failure_stats *mf_stats = \ | |
100 | &NODE_DATA(dev->id)->mf_stats; \ | |
101 | return sprintf(buf, "%lu\n", mf_stats->_name); \ | |
102 | } \ | |
103 | static DEVICE_ATTR_RO(_name) | |
104 | ||
105 | MF_ATTR_RO(total); | |
106 | MF_ATTR_RO(ignored); | |
107 | MF_ATTR_RO(failed); | |
108 | MF_ATTR_RO(delayed); | |
109 | MF_ATTR_RO(recovered); | |
110 | ||
111 | static struct attribute *memory_failure_attr[] = { | |
112 | &dev_attr_total.attr, | |
113 | &dev_attr_ignored.attr, | |
114 | &dev_attr_failed.attr, | |
115 | &dev_attr_delayed.attr, | |
116 | &dev_attr_recovered.attr, | |
117 | NULL, | |
118 | }; | |
119 | ||
120 | const struct attribute_group memory_failure_attr_group = { | |
121 | .name = "memory_failure", | |
122 | .attrs = memory_failure_attr, | |
123 | }; | |
124 | ||
8cbc82f3 KW |
125 | static struct ctl_table memory_failure_table[] = { |
126 | { | |
127 | .procname = "memory_failure_early_kill", | |
128 | .data = &sysctl_memory_failure_early_kill, | |
129 | .maxlen = sizeof(sysctl_memory_failure_early_kill), | |
130 | .mode = 0644, | |
131 | .proc_handler = proc_dointvec_minmax, | |
132 | .extra1 = SYSCTL_ZERO, | |
133 | .extra2 = SYSCTL_ONE, | |
134 | }, | |
135 | { | |
136 | .procname = "memory_failure_recovery", | |
137 | .data = &sysctl_memory_failure_recovery, | |
138 | .maxlen = sizeof(sysctl_memory_failure_recovery), | |
139 | .mode = 0644, | |
140 | .proc_handler = proc_dointvec_minmax, | |
141 | .extra1 = SYSCTL_ZERO, | |
142 | .extra2 = SYSCTL_ONE, | |
143 | }, | |
8cbc82f3 KW |
144 | }; |
145 | ||
7453bf62 NH |
146 | /* |
147 | * Return values: | |
148 | * 1: the page is dissolved (if needed) and taken off from buddy, | |
149 | * 0: the page is dissolved (if needed) and not taken off from buddy, | |
150 | * < 0: failed to dissolve. | |
151 | */ | |
152 | static int __page_handle_poison(struct page *page) | |
510d25c9 | 153 | { |
f87060d3 | 154 | int ret; |
510d25c9 | 155 | |
1983184c ML |
156 | /* |
157 | * zone_pcp_disable() can't be used here. It will | |
54fa49b2 | 158 | * hold pcp_batch_high_lock and dissolve_free_hugetlb_folio() might hold |
1983184c ML |
159 | * cpu_hotplug_lock via static_key_slow_dec() when hugetlb vmemmap |
160 | * optimization is enabled. This will break current lock dependency | |
161 | * chain and leads to deadlock. | |
162 | * Disabling pcp before dissolving the page was a deterministic | |
163 | * approach because we made sure that those pages cannot end up in any | |
164 | * PCP list. Draining PCP lists expels those pages to the buddy system, | |
165 | * but nothing guarantees that those pages do not get back to a PCP | |
166 | * queue if we need to refill those. | |
167 | */ | |
54fa49b2 | 168 | ret = dissolve_free_hugetlb_folio(page_folio(page)); |
1983184c ML |
169 | if (!ret) { |
170 | drain_all_pages(page_zone(page)); | |
510d25c9 | 171 | ret = take_page_off_buddy(page); |
1983184c | 172 | } |
510d25c9 | 173 | |
7453bf62 | 174 | return ret; |
510d25c9 NH |
175 | } |
176 | ||
6b9a217e | 177 | static bool page_handle_poison(struct page *page, bool hugepage_or_freepage, bool release) |
06be6ff3 | 178 | { |
6b9a217e OS |
179 | if (hugepage_or_freepage) { |
180 | /* | |
54fa49b2 SK |
181 | * Doing this check for free pages is also fine since |
182 | * dissolve_free_hugetlb_folio() returns 0 for non-hugetlb folios as well. | |
6b9a217e | 183 | */ |
7453bf62 | 184 | if (__page_handle_poison(page) <= 0) |
6b9a217e OS |
185 | /* |
186 | * We could fail to take off the target page from buddy | |
f0953a1b | 187 | * for example due to racy page allocation, but that's |
6b9a217e OS |
188 | * acceptable because soft-offlined page is not broken |
189 | * and if someone really want to use it, they should | |
190 | * take it. | |
191 | */ | |
192 | return false; | |
193 | } | |
194 | ||
06be6ff3 | 195 | SetPageHWPoison(page); |
79f5f8fa OS |
196 | if (release) |
197 | put_page(page); | |
06be6ff3 | 198 | page_ref_inc(page); |
a46c9304 | 199 | num_poisoned_pages_inc(page_to_pfn(page)); |
6b9a217e OS |
200 | |
201 | return true; | |
06be6ff3 OS |
202 | } |
203 | ||
611b9fd8 | 204 | #if IS_ENABLED(CONFIG_HWPOISON_INJECT) |
27df5068 | 205 | |
1bfe5feb | 206 | u32 hwpoison_filter_enable = 0; |
7c116f2b WF |
207 | u32 hwpoison_filter_dev_major = ~0U; |
208 | u32 hwpoison_filter_dev_minor = ~0U; | |
478c5ffc WF |
209 | u64 hwpoison_filter_flags_mask; |
210 | u64 hwpoison_filter_flags_value; | |
1bfe5feb | 211 | EXPORT_SYMBOL_GPL(hwpoison_filter_enable); |
7c116f2b WF |
212 | EXPORT_SYMBOL_GPL(hwpoison_filter_dev_major); |
213 | EXPORT_SYMBOL_GPL(hwpoison_filter_dev_minor); | |
478c5ffc WF |
214 | EXPORT_SYMBOL_GPL(hwpoison_filter_flags_mask); |
215 | EXPORT_SYMBOL_GPL(hwpoison_filter_flags_value); | |
7c116f2b WF |
216 | |
217 | static int hwpoison_filter_dev(struct page *p) | |
218 | { | |
89f5c54b | 219 | struct folio *folio = page_folio(p); |
7c116f2b WF |
220 | struct address_space *mapping; |
221 | dev_t dev; | |
222 | ||
223 | if (hwpoison_filter_dev_major == ~0U && | |
224 | hwpoison_filter_dev_minor == ~0U) | |
225 | return 0; | |
226 | ||
89f5c54b | 227 | mapping = folio_mapping(folio); |
7c116f2b WF |
228 | if (mapping == NULL || mapping->host == NULL) |
229 | return -EINVAL; | |
230 | ||
231 | dev = mapping->host->i_sb->s_dev; | |
232 | if (hwpoison_filter_dev_major != ~0U && | |
233 | hwpoison_filter_dev_major != MAJOR(dev)) | |
234 | return -EINVAL; | |
235 | if (hwpoison_filter_dev_minor != ~0U && | |
236 | hwpoison_filter_dev_minor != MINOR(dev)) | |
237 | return -EINVAL; | |
238 | ||
239 | return 0; | |
240 | } | |
241 | ||
478c5ffc WF |
242 | static int hwpoison_filter_flags(struct page *p) |
243 | { | |
244 | if (!hwpoison_filter_flags_mask) | |
245 | return 0; | |
246 | ||
247 | if ((stable_page_flags(p) & hwpoison_filter_flags_mask) == | |
248 | hwpoison_filter_flags_value) | |
249 | return 0; | |
250 | else | |
251 | return -EINVAL; | |
252 | } | |
253 | ||
4fd466eb AK |
254 | /* |
255 | * This allows stress tests to limit test scope to a collection of tasks | |
256 | * by putting them under some memcg. This prevents killing unrelated/important | |
257 | * processes such as /sbin/init. Note that the target task may share clean | |
258 | * pages with init (eg. libc text), which is harmless. If the target task | |
259 | * share _dirty_ pages with another task B, the test scheme must make sure B | |
260 | * is also included in the memcg. At last, due to race conditions this filter | |
261 | * can only guarantee that the page either belongs to the memcg tasks, or is | |
262 | * a freed page. | |
263 | */ | |
94a59fb3 | 264 | #ifdef CONFIG_MEMCG |
4fd466eb AK |
265 | u64 hwpoison_filter_memcg; |
266 | EXPORT_SYMBOL_GPL(hwpoison_filter_memcg); | |
267 | static int hwpoison_filter_task(struct page *p) | |
268 | { | |
4fd466eb AK |
269 | if (!hwpoison_filter_memcg) |
270 | return 0; | |
271 | ||
94a59fb3 | 272 | if (page_cgroup_ino(p) != hwpoison_filter_memcg) |
4fd466eb AK |
273 | return -EINVAL; |
274 | ||
275 | return 0; | |
276 | } | |
277 | #else | |
278 | static int hwpoison_filter_task(struct page *p) { return 0; } | |
279 | #endif | |
280 | ||
7c116f2b WF |
281 | int hwpoison_filter(struct page *p) |
282 | { | |
1bfe5feb HL |
283 | if (!hwpoison_filter_enable) |
284 | return 0; | |
285 | ||
7c116f2b WF |
286 | if (hwpoison_filter_dev(p)) |
287 | return -EINVAL; | |
288 | ||
478c5ffc WF |
289 | if (hwpoison_filter_flags(p)) |
290 | return -EINVAL; | |
291 | ||
4fd466eb AK |
292 | if (hwpoison_filter_task(p)) |
293 | return -EINVAL; | |
294 | ||
7c116f2b WF |
295 | return 0; |
296 | } | |
27df5068 AK |
297 | #else |
298 | int hwpoison_filter(struct page *p) | |
299 | { | |
300 | return 0; | |
301 | } | |
302 | #endif | |
303 | ||
7c116f2b WF |
304 | EXPORT_SYMBOL_GPL(hwpoison_filter); |
305 | ||
ae1139ec DW |
306 | /* |
307 | * Kill all processes that have a poisoned page mapped and then isolate | |
308 | * the page. | |
309 | * | |
310 | * General strategy: | |
311 | * Find all processes having the page mapped and kill them. | |
312 | * But we keep a page reference around so that the page is not | |
313 | * actually freed yet. | |
314 | * Then stash the page away | |
315 | * | |
316 | * There's no convenient way to get back to mapped processes | |
317 | * from the VMAs. So do a brute-force search over all | |
318 | * running processes. | |
319 | * | |
320 | * Remember that machine checks are not common (or rather | |
321 | * if they are common you have other problems), so this shouldn't | |
322 | * be a performance issue. | |
323 | * | |
324 | * Also there are some races possible while we get from the | |
325 | * error detection to actually handle it. | |
326 | */ | |
327 | ||
328 | struct to_kill { | |
329 | struct list_head nd; | |
330 | struct task_struct *tsk; | |
331 | unsigned long addr; | |
332 | short size_shift; | |
ae1139ec DW |
333 | }; |
334 | ||
6a46079c | 335 | /* |
7329bbeb TL |
336 | * Send all the processes who have the page mapped a signal. |
337 | * ``action optional'' if they are not immediately affected by the error | |
338 | * ``action required'' if error happened in current execution context | |
6a46079c | 339 | */ |
ae1139ec | 340 | static int kill_proc(struct to_kill *tk, unsigned long pfn, int flags) |
6a46079c | 341 | { |
ae1139ec DW |
342 | struct task_struct *t = tk->tsk; |
343 | short addr_lsb = tk->size_shift; | |
872e9a20 | 344 | int ret = 0; |
6a46079c | 345 | |
96f96763 | 346 | pr_err("%#lx: Sending SIGBUS to %s:%d due to hardware memory corruption\n", |
872e9a20 | 347 | pfn, t->comm, t->pid); |
7329bbeb | 348 | |
49775047 ML |
349 | if ((flags & MF_ACTION_REQUIRED) && (t == current)) |
350 | ret = force_sig_mceerr(BUS_MCEERR_AR, | |
351 | (void __user *)tk->addr, addr_lsb); | |
352 | else | |
7329bbeb | 353 | /* |
49775047 ML |
354 | * Signal other processes sharing the page if they have |
355 | * PF_MCE_EARLY set. | |
7329bbeb TL |
356 | * Don't use force here, it's convenient if the signal |
357 | * can be temporarily blocked. | |
358 | * This could cause a loop when the user sets SIGBUS | |
359 | * to SIG_IGN, but hopefully no one will do that? | |
360 | */ | |
ae1139ec | 361 | ret = send_sig_mceerr(BUS_MCEERR_AO, (void __user *)tk->addr, |
9cf28191 | 362 | addr_lsb, t); |
6a46079c | 363 | if (ret < 0) |
96f96763 | 364 | pr_info("Error sending signal to %s:%d: %d\n", |
1170532b | 365 | t->comm, t->pid, ret); |
6a46079c AK |
366 | return ret; |
367 | } | |
368 | ||
588f9ce6 | 369 | /* |
47e431f4 | 370 | * Unknown page type encountered. Try to check whether it can turn PageLRU by |
d0505e9f | 371 | * lru_add_drain_all. |
588f9ce6 | 372 | */ |
fed5348e | 373 | void shake_folio(struct folio *folio) |
588f9ce6 | 374 | { |
fed5348e | 375 | if (folio_test_hugetlb(folio)) |
8bcb74de | 376 | return; |
588f9ce6 | 377 | /* |
d0505e9f YS |
378 | * TODO: Could shrink slab caches here if a lightweight range-based |
379 | * shrinker will be available. | |
588f9ce6 | 380 | */ |
fed5348e | 381 | if (folio_test_slab(folio)) |
b7b618da ML |
382 | return; |
383 | ||
384 | lru_add_drain_all(); | |
588f9ce6 | 385 | } |
fed5348e MWO |
386 | EXPORT_SYMBOL_GPL(shake_folio); |
387 | ||
388 | static void shake_page(struct page *page) | |
389 | { | |
390 | shake_folio(page_folio(page)); | |
391 | } | |
588f9ce6 | 392 | |
c36e2024 SR |
393 | static unsigned long dev_pagemap_mapping_shift(struct vm_area_struct *vma, |
394 | unsigned long address) | |
6100e34b | 395 | { |
5c91c0e7 | 396 | unsigned long ret = 0; |
6100e34b DW |
397 | pgd_t *pgd; |
398 | p4d_t *p4d; | |
399 | pud_t *pud; | |
400 | pmd_t *pmd; | |
401 | pte_t *pte; | |
c33c7948 | 402 | pte_t ptent; |
6100e34b | 403 | |
a994402b | 404 | VM_BUG_ON_VMA(address == -EFAULT, vma); |
6100e34b DW |
405 | pgd = pgd_offset(vma->vm_mm, address); |
406 | if (!pgd_present(*pgd)) | |
407 | return 0; | |
408 | p4d = p4d_offset(pgd, address); | |
409 | if (!p4d_present(*p4d)) | |
410 | return 0; | |
411 | pud = pud_offset(p4d, address); | |
412 | if (!pud_present(*pud)) | |
413 | return 0; | |
414 | if (pud_devmap(*pud)) | |
415 | return PUD_SHIFT; | |
416 | pmd = pmd_offset(pud, address); | |
417 | if (!pmd_present(*pmd)) | |
418 | return 0; | |
419 | if (pmd_devmap(*pmd)) | |
420 | return PMD_SHIFT; | |
421 | pte = pte_offset_map(pmd, address); | |
04dee9e8 HD |
422 | if (!pte) |
423 | return 0; | |
c33c7948 RR |
424 | ptent = ptep_get(pte); |
425 | if (pte_present(ptent) && pte_devmap(ptent)) | |
5c91c0e7 QZ |
426 | ret = PAGE_SHIFT; |
427 | pte_unmap(pte); | |
428 | return ret; | |
6100e34b | 429 | } |
6a46079c AK |
430 | |
431 | /* | |
432 | * Failure handling: if we can't find or can't kill a process there's | |
433 | * not much we can do. We just print a message and ignore otherwise. | |
434 | */ | |
435 | ||
436 | /* | |
437 | * Schedule a process for later kill. | |
438 | * Uses GFP_ATOMIC allocations to avoid potential recursions in the VM. | |
6a46079c | 439 | */ |
4f775086 LX |
440 | static void __add_to_kill(struct task_struct *tsk, struct page *p, |
441 | struct vm_area_struct *vma, struct list_head *to_kill, | |
1c0501e8 | 442 | unsigned long addr) |
6a46079c AK |
443 | { |
444 | struct to_kill *tk; | |
445 | ||
996ff7a0 JC |
446 | tk = kmalloc(sizeof(struct to_kill), GFP_ATOMIC); |
447 | if (!tk) { | |
96f96763 | 448 | pr_err("Out of memory while machine check handling\n"); |
996ff7a0 | 449 | return; |
6a46079c | 450 | } |
996ff7a0 | 451 | |
f2b37197 | 452 | tk->addr = addr; |
1c0501e8 | 453 | if (is_zone_device_page(p)) |
c36e2024 | 454 | tk->size_shift = dev_pagemap_mapping_shift(vma, tk->addr); |
1c0501e8 | 455 | else |
75068518 | 456 | tk->size_shift = page_shift(compound_head(p)); |
6a46079c AK |
457 | |
458 | /* | |
3d7fed4a JC |
459 | * Send SIGKILL if "tk->addr == -EFAULT". Also, as |
460 | * "tk->size_shift" is always non-zero for !is_zone_device_page(), | |
461 | * so "tk->size_shift == 0" effectively checks no mapping on | |
462 | * ZONE_DEVICE. Indeed, when a devdax page is mmapped N times | |
463 | * to a process' address space, it's possible not all N VMAs | |
464 | * contain mappings for the page, but at least one VMA does. | |
465 | * Only deliver SIGBUS with payload derived from the VMA that | |
466 | * has a mapping for the page. | |
6a46079c | 467 | */ |
3d7fed4a | 468 | if (tk->addr == -EFAULT) { |
96f96763 | 469 | pr_info("Unable to find user space address %lx in %s\n", |
6a46079c | 470 | page_to_pfn(p), tsk->comm); |
3d7fed4a JC |
471 | } else if (tk->size_shift == 0) { |
472 | kfree(tk); | |
473 | return; | |
6a46079c | 474 | } |
996ff7a0 | 475 | |
6a46079c AK |
476 | get_task_struct(tsk); |
477 | tk->tsk = tsk; | |
478 | list_add_tail(&tk->nd, to_kill); | |
479 | } | |
480 | ||
4f775086 | 481 | static void add_to_kill_anon_file(struct task_struct *tsk, struct page *p, |
37bc2ff5 MWO |
482 | struct vm_area_struct *vma, struct list_head *to_kill, |
483 | unsigned long addr) | |
4f775086 | 484 | { |
37bc2ff5 MWO |
485 | if (addr == -EFAULT) |
486 | return; | |
f2b37197 | 487 | __add_to_kill(tsk, p, vma, to_kill, addr); |
4f775086 LX |
488 | } |
489 | ||
4248d008 LX |
490 | #ifdef CONFIG_KSM |
491 | static bool task_in_to_kill_list(struct list_head *to_kill, | |
492 | struct task_struct *tsk) | |
493 | { | |
494 | struct to_kill *tk, *next; | |
495 | ||
496 | list_for_each_entry_safe(tk, next, to_kill, nd) { | |
497 | if (tk->tsk == tsk) | |
498 | return true; | |
499 | } | |
500 | ||
501 | return false; | |
502 | } | |
f2b37197 | 503 | |
4248d008 LX |
504 | void add_to_kill_ksm(struct task_struct *tsk, struct page *p, |
505 | struct vm_area_struct *vma, struct list_head *to_kill, | |
1c0501e8 | 506 | unsigned long addr) |
4248d008 LX |
507 | { |
508 | if (!task_in_to_kill_list(to_kill, tsk)) | |
1c0501e8 | 509 | __add_to_kill(tsk, p, vma, to_kill, addr); |
4248d008 LX |
510 | } |
511 | #endif | |
6a46079c AK |
512 | /* |
513 | * Kill the processes that have been collected earlier. | |
514 | * | |
a21c184f ML |
515 | * Only do anything when FORCEKILL is set, otherwise just free the |
516 | * list (this is used for clean pages which do not need killing) | |
6a46079c AK |
517 | * Also when FAIL is set do a force kill because something went |
518 | * wrong earlier. | |
519 | */ | |
ae1139ec DW |
520 | static void kill_procs(struct list_head *to_kill, int forcekill, bool fail, |
521 | unsigned long pfn, int flags) | |
6a46079c AK |
522 | { |
523 | struct to_kill *tk, *next; | |
524 | ||
54f9555d | 525 | list_for_each_entry_safe(tk, next, to_kill, nd) { |
6751ed65 | 526 | if (forcekill) { |
6a46079c | 527 | /* |
af901ca1 | 528 | * In case something went wrong with munmapping |
6a46079c AK |
529 | * make sure the process doesn't catch the |
530 | * signal and then access the memory. Just kill it. | |
6a46079c | 531 | */ |
3d7fed4a | 532 | if (fail || tk->addr == -EFAULT) { |
96f96763 | 533 | pr_err("%#lx: forcibly killing %s:%d because of failure to unmap corrupted page\n", |
1170532b | 534 | pfn, tk->tsk->comm, tk->tsk->pid); |
6376360e NH |
535 | do_send_sig_info(SIGKILL, SEND_SIG_PRIV, |
536 | tk->tsk, PIDTYPE_PID); | |
6a46079c AK |
537 | } |
538 | ||
539 | /* | |
540 | * In theory the process could have mapped | |
541 | * something else on the address in-between. We could | |
542 | * check for that, but we need to tell the | |
543 | * process anyways. | |
544 | */ | |
ae1139ec | 545 | else if (kill_proc(tk, pfn, flags) < 0) |
96f96763 | 546 | pr_err("%#lx: Cannot send advisory machine check signal to %s:%d\n", |
1170532b | 547 | pfn, tk->tsk->comm, tk->tsk->pid); |
6a46079c | 548 | } |
54f9555d | 549 | list_del(&tk->nd); |
6a46079c AK |
550 | put_task_struct(tk->tsk); |
551 | kfree(tk); | |
552 | } | |
553 | } | |
554 | ||
3ba08129 NH |
555 | /* |
556 | * Find a dedicated thread which is supposed to handle SIGBUS(BUS_MCEERR_AO) | |
557 | * on behalf of the thread group. Return task_struct of the (first found) | |
558 | * dedicated thread if found, and return NULL otherwise. | |
559 | * | |
d256d1cd TT |
560 | * We already hold rcu lock in the caller, so we don't have to call |
561 | * rcu_read_lock/unlock() in this function. | |
3ba08129 NH |
562 | */ |
563 | static struct task_struct *find_early_kill_thread(struct task_struct *tsk) | |
6a46079c | 564 | { |
3ba08129 NH |
565 | struct task_struct *t; |
566 | ||
4e018b45 NH |
567 | for_each_thread(tsk, t) { |
568 | if (t->flags & PF_MCE_PROCESS) { | |
569 | if (t->flags & PF_MCE_EARLY) | |
570 | return t; | |
571 | } else { | |
572 | if (sysctl_memory_failure_early_kill) | |
573 | return t; | |
574 | } | |
575 | } | |
3ba08129 NH |
576 | return NULL; |
577 | } | |
578 | ||
579 | /* | |
580 | * Determine whether a given process is "early kill" process which expects | |
581 | * to be signaled when some page under the process is hwpoisoned. | |
582 | * Return task_struct of the dedicated thread (main thread unless explicitly | |
30c9cf49 | 583 | * specified) if the process is "early kill" and otherwise returns NULL. |
03151c6e | 584 | * |
30c9cf49 AY |
585 | * Note that the above is true for Action Optional case. For Action Required |
586 | * case, it's only meaningful to the current thread which need to be signaled | |
587 | * with SIGBUS, this error is Action Optional for other non current | |
588 | * processes sharing the same error page,if the process is "early kill", the | |
589 | * task_struct of the dedicated thread will also be returned. | |
3ba08129 | 590 | */ |
4248d008 | 591 | struct task_struct *task_early_kill(struct task_struct *tsk, int force_early) |
3ba08129 | 592 | { |
6a46079c | 593 | if (!tsk->mm) |
3ba08129 | 594 | return NULL; |
30c9cf49 AY |
595 | /* |
596 | * Comparing ->mm here because current task might represent | |
597 | * a subthread, while tsk always points to the main thread. | |
598 | */ | |
599 | if (force_early && tsk->mm == current->mm) | |
600 | return current; | |
601 | ||
4e018b45 | 602 | return find_early_kill_thread(tsk); |
6a46079c AK |
603 | } |
604 | ||
605 | /* | |
606 | * Collect processes when the error hit an anonymous page. | |
607 | */ | |
376907f3 MWO |
608 | static void collect_procs_anon(struct folio *folio, struct page *page, |
609 | struct list_head *to_kill, int force_early) | |
6a46079c | 610 | { |
6a46079c AK |
611 | struct task_struct *tsk; |
612 | struct anon_vma *av; | |
bf181b9f | 613 | pgoff_t pgoff; |
6a46079c | 614 | |
6d4675e6 | 615 | av = folio_lock_anon_vma_read(folio, NULL); |
6a46079c | 616 | if (av == NULL) /* Not actually mapped anymore */ |
9b679320 PZ |
617 | return; |
618 | ||
a0f7a756 | 619 | pgoff = page_to_pgoff(page); |
d256d1cd | 620 | rcu_read_lock(); |
5885c6a6 | 621 | for_each_process(tsk) { |
37bc2ff5 | 622 | struct vm_area_struct *vma; |
5beb4930 | 623 | struct anon_vma_chain *vmac; |
3ba08129 | 624 | struct task_struct *t = task_early_kill(tsk, force_early); |
37bc2ff5 | 625 | unsigned long addr; |
5beb4930 | 626 | |
3ba08129 | 627 | if (!t) |
6a46079c | 628 | continue; |
bf181b9f ML |
629 | anon_vma_interval_tree_foreach(vmac, &av->rb_root, |
630 | pgoff, pgoff) { | |
5beb4930 | 631 | vma = vmac->vma; |
36537a67 ML |
632 | if (vma->vm_mm != t->mm) |
633 | continue; | |
37bc2ff5 MWO |
634 | addr = page_mapped_in_vma(page, vma); |
635 | add_to_kill_anon_file(t, page, vma, to_kill, addr); | |
6a46079c AK |
636 | } |
637 | } | |
d256d1cd | 638 | rcu_read_unlock(); |
0c826c0b | 639 | anon_vma_unlock_read(av); |
6a46079c AK |
640 | } |
641 | ||
642 | /* | |
643 | * Collect processes when the error hit a file mapped page. | |
644 | */ | |
376907f3 MWO |
645 | static void collect_procs_file(struct folio *folio, struct page *page, |
646 | struct list_head *to_kill, int force_early) | |
6a46079c AK |
647 | { |
648 | struct vm_area_struct *vma; | |
649 | struct task_struct *tsk; | |
376907f3 | 650 | struct address_space *mapping = folio->mapping; |
c43bc03d | 651 | pgoff_t pgoff; |
6a46079c | 652 | |
d28eb9c8 | 653 | i_mmap_lock_read(mapping); |
d256d1cd | 654 | rcu_read_lock(); |
c43bc03d | 655 | pgoff = page_to_pgoff(page); |
6a46079c | 656 | for_each_process(tsk) { |
3ba08129 | 657 | struct task_struct *t = task_early_kill(tsk, force_early); |
37bc2ff5 | 658 | unsigned long addr; |
6a46079c | 659 | |
3ba08129 | 660 | if (!t) |
6a46079c | 661 | continue; |
6b2dbba8 | 662 | vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, |
6a46079c AK |
663 | pgoff) { |
664 | /* | |
665 | * Send early kill signal to tasks where a vma covers | |
666 | * the page but the corrupted page is not necessarily | |
5885c6a6 | 667 | * mapped in its pte. |
6a46079c AK |
668 | * Assume applications who requested early kill want |
669 | * to be informed of all such data corruptions. | |
670 | */ | |
37bc2ff5 MWO |
671 | if (vma->vm_mm != t->mm) |
672 | continue; | |
673 | addr = page_address_in_vma(page, vma); | |
674 | add_to_kill_anon_file(t, page, vma, to_kill, addr); | |
6a46079c AK |
675 | } |
676 | } | |
d256d1cd | 677 | rcu_read_unlock(); |
d28eb9c8 | 678 | i_mmap_unlock_read(mapping); |
6a46079c AK |
679 | } |
680 | ||
c36e2024 | 681 | #ifdef CONFIG_FS_DAX |
4f775086 LX |
682 | static void add_to_kill_fsdax(struct task_struct *tsk, struct page *p, |
683 | struct vm_area_struct *vma, | |
684 | struct list_head *to_kill, pgoff_t pgoff) | |
685 | { | |
1c0501e8 MWO |
686 | unsigned long addr = vma_address(vma, pgoff, 1); |
687 | __add_to_kill(tsk, p, vma, to_kill, addr); | |
4f775086 LX |
688 | } |
689 | ||
c36e2024 SR |
690 | /* |
691 | * Collect processes when the error hit a fsdax page. | |
692 | */ | |
693 | static void collect_procs_fsdax(struct page *page, | |
694 | struct address_space *mapping, pgoff_t pgoff, | |
fa422b35 | 695 | struct list_head *to_kill, bool pre_remove) |
c36e2024 SR |
696 | { |
697 | struct vm_area_struct *vma; | |
698 | struct task_struct *tsk; | |
699 | ||
700 | i_mmap_lock_read(mapping); | |
d256d1cd | 701 | rcu_read_lock(); |
c36e2024 | 702 | for_each_process(tsk) { |
fa422b35 | 703 | struct task_struct *t = tsk; |
c36e2024 | 704 | |
fa422b35 SR |
705 | /* |
706 | * Search for all tasks while MF_MEM_PRE_REMOVE is set, because | |
707 | * the current may not be the one accessing the fsdax page. | |
708 | * Otherwise, search for the current task. | |
709 | */ | |
710 | if (!pre_remove) | |
711 | t = task_early_kill(tsk, true); | |
c36e2024 SR |
712 | if (!t) |
713 | continue; | |
714 | vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff) { | |
715 | if (vma->vm_mm == t->mm) | |
4f775086 | 716 | add_to_kill_fsdax(t, page, vma, to_kill, pgoff); |
c36e2024 SR |
717 | } |
718 | } | |
d256d1cd | 719 | rcu_read_unlock(); |
c36e2024 SR |
720 | i_mmap_unlock_read(mapping); |
721 | } | |
722 | #endif /* CONFIG_FS_DAX */ | |
723 | ||
6a46079c AK |
724 | /* |
725 | * Collect the processes who have the corrupted page mapped to kill. | |
6a46079c | 726 | */ |
376907f3 MWO |
727 | static void collect_procs(struct folio *folio, struct page *page, |
728 | struct list_head *tokill, int force_early) | |
6a46079c | 729 | { |
376907f3 | 730 | if (!folio->mapping) |
6a46079c | 731 | return; |
0edb5b28 | 732 | if (unlikely(folio_test_ksm(folio))) |
b650e1d2 | 733 | collect_procs_ksm(folio, page, tokill, force_early); |
0edb5b28 | 734 | else if (folio_test_anon(folio)) |
376907f3 | 735 | collect_procs_anon(folio, page, tokill, force_early); |
6a46079c | 736 | else |
376907f3 | 737 | collect_procs_file(folio, page, tokill, force_early); |
6a46079c AK |
738 | } |
739 | ||
6885938c | 740 | struct hwpoison_walk { |
a3f5d80e NH |
741 | struct to_kill tk; |
742 | unsigned long pfn; | |
743 | int flags; | |
744 | }; | |
745 | ||
746 | static void set_to_kill(struct to_kill *tk, unsigned long addr, short shift) | |
747 | { | |
748 | tk->addr = addr; | |
749 | tk->size_shift = shift; | |
750 | } | |
751 | ||
752 | static int check_hwpoisoned_entry(pte_t pte, unsigned long addr, short shift, | |
753 | unsigned long poisoned_pfn, struct to_kill *tk) | |
754 | { | |
755 | unsigned long pfn = 0; | |
756 | ||
757 | if (pte_present(pte)) { | |
758 | pfn = pte_pfn(pte); | |
759 | } else { | |
760 | swp_entry_t swp = pte_to_swp_entry(pte); | |
761 | ||
762 | if (is_hwpoison_entry(swp)) | |
0d206b5d | 763 | pfn = swp_offset_pfn(swp); |
a3f5d80e NH |
764 | } |
765 | ||
766 | if (!pfn || pfn != poisoned_pfn) | |
767 | return 0; | |
768 | ||
769 | set_to_kill(tk, addr, shift); | |
770 | return 1; | |
771 | } | |
772 | ||
773 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE | |
774 | static int check_hwpoisoned_pmd_entry(pmd_t *pmdp, unsigned long addr, | |
6885938c | 775 | struct hwpoison_walk *hwp) |
a3f5d80e NH |
776 | { |
777 | pmd_t pmd = *pmdp; | |
778 | unsigned long pfn; | |
779 | unsigned long hwpoison_vaddr; | |
780 | ||
781 | if (!pmd_present(pmd)) | |
782 | return 0; | |
783 | pfn = pmd_pfn(pmd); | |
784 | if (pfn <= hwp->pfn && hwp->pfn < pfn + HPAGE_PMD_NR) { | |
785 | hwpoison_vaddr = addr + ((hwp->pfn - pfn) << PAGE_SHIFT); | |
786 | set_to_kill(&hwp->tk, hwpoison_vaddr, PAGE_SHIFT); | |
787 | return 1; | |
788 | } | |
789 | return 0; | |
790 | } | |
791 | #else | |
792 | static int check_hwpoisoned_pmd_entry(pmd_t *pmdp, unsigned long addr, | |
6885938c | 793 | struct hwpoison_walk *hwp) |
a3f5d80e NH |
794 | { |
795 | return 0; | |
796 | } | |
797 | #endif | |
798 | ||
799 | static int hwpoison_pte_range(pmd_t *pmdp, unsigned long addr, | |
800 | unsigned long end, struct mm_walk *walk) | |
801 | { | |
6885938c | 802 | struct hwpoison_walk *hwp = walk->private; |
a3f5d80e | 803 | int ret = 0; |
ea3732f7 | 804 | pte_t *ptep, *mapped_pte; |
a3f5d80e NH |
805 | spinlock_t *ptl; |
806 | ||
807 | ptl = pmd_trans_huge_lock(pmdp, walk->vma); | |
808 | if (ptl) { | |
809 | ret = check_hwpoisoned_pmd_entry(pmdp, addr, hwp); | |
810 | spin_unlock(ptl); | |
811 | goto out; | |
812 | } | |
813 | ||
ea3732f7 ML |
814 | mapped_pte = ptep = pte_offset_map_lock(walk->vma->vm_mm, pmdp, |
815 | addr, &ptl); | |
04dee9e8 HD |
816 | if (!ptep) |
817 | goto out; | |
818 | ||
a3f5d80e | 819 | for (; addr != end; ptep++, addr += PAGE_SIZE) { |
c33c7948 | 820 | ret = check_hwpoisoned_entry(ptep_get(ptep), addr, PAGE_SHIFT, |
a3f5d80e NH |
821 | hwp->pfn, &hwp->tk); |
822 | if (ret == 1) | |
823 | break; | |
824 | } | |
ea3732f7 | 825 | pte_unmap_unlock(mapped_pte, ptl); |
a3f5d80e NH |
826 | out: |
827 | cond_resched(); | |
828 | return ret; | |
829 | } | |
830 | ||
831 | #ifdef CONFIG_HUGETLB_PAGE | |
832 | static int hwpoison_hugetlb_range(pte_t *ptep, unsigned long hmask, | |
833 | unsigned long addr, unsigned long end, | |
834 | struct mm_walk *walk) | |
835 | { | |
6885938c | 836 | struct hwpoison_walk *hwp = walk->private; |
a3f5d80e NH |
837 | pte_t pte = huge_ptep_get(ptep); |
838 | struct hstate *h = hstate_vma(walk->vma); | |
839 | ||
840 | return check_hwpoisoned_entry(pte, addr, huge_page_shift(h), | |
841 | hwp->pfn, &hwp->tk); | |
842 | } | |
843 | #else | |
844 | #define hwpoison_hugetlb_range NULL | |
845 | #endif | |
846 | ||
6885938c | 847 | static const struct mm_walk_ops hwpoison_walk_ops = { |
a3f5d80e NH |
848 | .pmd_entry = hwpoison_pte_range, |
849 | .hugetlb_entry = hwpoison_hugetlb_range, | |
49b06385 | 850 | .walk_lock = PGWALK_RDLOCK, |
a3f5d80e NH |
851 | }; |
852 | ||
853 | /* | |
854 | * Sends SIGBUS to the current process with error info. | |
855 | * | |
856 | * This function is intended to handle "Action Required" MCEs on already | |
857 | * hardware poisoned pages. They could happen, for example, when | |
858 | * memory_failure() failed to unmap the error page at the first call, or | |
859 | * when multiple local machine checks happened on different CPUs. | |
860 | * | |
861 | * MCE handler currently has no easy access to the error virtual address, | |
862 | * so this function walks page table to find it. The returned virtual address | |
863 | * is proper in most cases, but it could be wrong when the application | |
864 | * process has multiple entries mapping the error page. | |
865 | */ | |
866 | static int kill_accessing_process(struct task_struct *p, unsigned long pfn, | |
867 | int flags) | |
868 | { | |
869 | int ret; | |
6885938c | 870 | struct hwpoison_walk priv = { |
a3f5d80e NH |
871 | .pfn = pfn, |
872 | }; | |
873 | priv.tk.tsk = p; | |
874 | ||
77677cdb SX |
875 | if (!p->mm) |
876 | return -EFAULT; | |
877 | ||
a3f5d80e | 878 | mmap_read_lock(p->mm); |
6885938c | 879 | ret = walk_page_range(p->mm, 0, TASK_SIZE, &hwpoison_walk_ops, |
a3f5d80e NH |
880 | (void *)&priv); |
881 | if (ret == 1 && priv.tk.addr) | |
882 | kill_proc(&priv.tk, pfn, flags); | |
046545a6 NH |
883 | else |
884 | ret = 0; | |
a3f5d80e | 885 | mmap_read_unlock(p->mm); |
046545a6 | 886 | return ret > 0 ? -EHWPOISON : -EFAULT; |
a3f5d80e NH |
887 | } |
888 | ||
6a46079c | 889 | static const char *action_name[] = { |
cc637b17 XX |
890 | [MF_IGNORED] = "Ignored", |
891 | [MF_FAILED] = "Failed", | |
892 | [MF_DELAYED] = "Delayed", | |
893 | [MF_RECOVERED] = "Recovered", | |
64d37a2b NH |
894 | }; |
895 | ||
896 | static const char * const action_page_types[] = { | |
cc637b17 XX |
897 | [MF_MSG_KERNEL] = "reserved kernel page", |
898 | [MF_MSG_KERNEL_HIGH_ORDER] = "high-order kernel page", | |
899 | [MF_MSG_SLAB] = "kernel slab page", | |
900 | [MF_MSG_DIFFERENT_COMPOUND] = "different compound page after locking", | |
cc637b17 XX |
901 | [MF_MSG_HUGE] = "huge page", |
902 | [MF_MSG_FREE_HUGE] = "free huge page", | |
903 | [MF_MSG_UNMAP_FAILED] = "unmapping failed page", | |
904 | [MF_MSG_DIRTY_SWAPCACHE] = "dirty swapcache page", | |
905 | [MF_MSG_CLEAN_SWAPCACHE] = "clean swapcache page", | |
906 | [MF_MSG_DIRTY_MLOCKED_LRU] = "dirty mlocked LRU page", | |
907 | [MF_MSG_CLEAN_MLOCKED_LRU] = "clean mlocked LRU page", | |
908 | [MF_MSG_DIRTY_UNEVICTABLE_LRU] = "dirty unevictable LRU page", | |
909 | [MF_MSG_CLEAN_UNEVICTABLE_LRU] = "clean unevictable LRU page", | |
910 | [MF_MSG_DIRTY_LRU] = "dirty LRU page", | |
911 | [MF_MSG_CLEAN_LRU] = "clean LRU page", | |
912 | [MF_MSG_TRUNCATED_LRU] = "already truncated LRU page", | |
913 | [MF_MSG_BUDDY] = "free buddy page", | |
6100e34b | 914 | [MF_MSG_DAX] = "dax page", |
5d1fd5dc | 915 | [MF_MSG_UNSPLIT_THP] = "unsplit thp", |
cc637b17 | 916 | [MF_MSG_UNKNOWN] = "unknown page", |
64d37a2b NH |
917 | }; |
918 | ||
dc2a1cbf WF |
919 | /* |
920 | * XXX: It is possible that a page is isolated from LRU cache, | |
921 | * and then kept in swap cache or failed to remove from page cache. | |
922 | * The page count will stop it from being freed by unpoison. | |
923 | * Stress tests should be aware of this memory leak problem. | |
924 | */ | |
f7092393 | 925 | static int delete_from_lru_cache(struct folio *folio) |
dc2a1cbf | 926 | { |
f7092393 | 927 | if (folio_isolate_lru(folio)) { |
dc2a1cbf WF |
928 | /* |
929 | * Clear sensible page flags, so that the buddy system won't | |
f7092393 | 930 | * complain when the folio is unpoison-and-freed. |
dc2a1cbf | 931 | */ |
f7092393 MWO |
932 | folio_clear_active(folio); |
933 | folio_clear_unevictable(folio); | |
18365225 MH |
934 | |
935 | /* | |
936 | * Poisoned page might never drop its ref count to 0 so we have | |
937 | * to uncharge it manually from its memcg. | |
938 | */ | |
f7092393 | 939 | mem_cgroup_uncharge(folio); |
18365225 | 940 | |
dc2a1cbf | 941 | /* |
f7092393 | 942 | * drop the refcount elevated by folio_isolate_lru() |
dc2a1cbf | 943 | */ |
f7092393 | 944 | folio_put(folio); |
dc2a1cbf WF |
945 | return 0; |
946 | } | |
947 | return -EIO; | |
948 | } | |
949 | ||
af7628d6 | 950 | static int truncate_error_folio(struct folio *folio, unsigned long pfn, |
78bb9203 NH |
951 | struct address_space *mapping) |
952 | { | |
953 | int ret = MF_FAILED; | |
954 | ||
af7628d6 MWO |
955 | if (mapping->a_ops->error_remove_folio) { |
956 | int err = mapping->a_ops->error_remove_folio(mapping, folio); | |
78bb9203 | 957 | |
0201ebf2 | 958 | if (err != 0) |
96f96763 | 959 | pr_info("%#lx: Failed to punch page: %d\n", pfn, err); |
0201ebf2 | 960 | else if (!filemap_release_folio(folio, GFP_NOIO)) |
96f96763 | 961 | pr_info("%#lx: failed to release buffers\n", pfn); |
0201ebf2 | 962 | else |
78bb9203 | 963 | ret = MF_RECOVERED; |
78bb9203 NH |
964 | } else { |
965 | /* | |
966 | * If the file system doesn't support it just invalidate | |
967 | * This fails on dirty or anything with private pages | |
968 | */ | |
19369d86 | 969 | if (mapping_evict_folio(mapping, folio)) |
78bb9203 NH |
970 | ret = MF_RECOVERED; |
971 | else | |
96f96763 | 972 | pr_info("%#lx: Failed to invalidate\n", pfn); |
78bb9203 NH |
973 | } |
974 | ||
975 | return ret; | |
976 | } | |
977 | ||
dd0f230a YS |
978 | struct page_state { |
979 | unsigned long mask; | |
980 | unsigned long res; | |
981 | enum mf_action_page_type type; | |
982 | ||
983 | /* Callback ->action() has to unlock the relevant page inside it. */ | |
984 | int (*action)(struct page_state *ps, struct page *p); | |
985 | }; | |
986 | ||
987 | /* | |
988 | * Return true if page is still referenced by others, otherwise return | |
989 | * false. | |
990 | * | |
991 | * The extra_pins is true when one extra refcount is expected. | |
992 | */ | |
993 | static bool has_extra_refcount(struct page_state *ps, struct page *p, | |
994 | bool extra_pins) | |
995 | { | |
996 | int count = page_count(p) - 1; | |
997 | ||
998 | if (extra_pins) | |
19d3e221 | 999 | count -= folio_nr_pages(page_folio(p)); |
dd0f230a YS |
1000 | |
1001 | if (count > 0) { | |
96f96763 | 1002 | pr_err("%#lx: %s still referenced by %d users\n", |
dd0f230a YS |
1003 | page_to_pfn(p), action_page_types[ps->type], count); |
1004 | return true; | |
1005 | } | |
1006 | ||
1007 | return false; | |
1008 | } | |
1009 | ||
6a46079c AK |
1010 | /* |
1011 | * Error hit kernel page. | |
1012 | * Do nothing, try to be lucky and not touch this instead. For a few cases we | |
1013 | * could be more sophisticated. | |
1014 | */ | |
dd0f230a | 1015 | static int me_kernel(struct page_state *ps, struct page *p) |
6a46079c | 1016 | { |
ea6d0630 | 1017 | unlock_page(p); |
cc637b17 | 1018 | return MF_IGNORED; |
6a46079c AK |
1019 | } |
1020 | ||
1021 | /* | |
1022 | * Page in unknown state. Do nothing. | |
1023 | */ | |
dd0f230a | 1024 | static int me_unknown(struct page_state *ps, struct page *p) |
6a46079c | 1025 | { |
96f96763 | 1026 | pr_err("%#lx: Unknown page state\n", page_to_pfn(p)); |
ea6d0630 | 1027 | unlock_page(p); |
cc637b17 | 1028 | return MF_FAILED; |
6a46079c AK |
1029 | } |
1030 | ||
6a46079c AK |
1031 | /* |
1032 | * Clean (or cleaned) page cache page. | |
1033 | */ | |
dd0f230a | 1034 | static int me_pagecache_clean(struct page_state *ps, struct page *p) |
6a46079c | 1035 | { |
3d47e317 | 1036 | struct folio *folio = page_folio(p); |
ea6d0630 | 1037 | int ret; |
6a46079c | 1038 | struct address_space *mapping; |
a7605426 | 1039 | bool extra_pins; |
6a46079c | 1040 | |
f7092393 | 1041 | delete_from_lru_cache(folio); |
dc2a1cbf | 1042 | |
6a46079c | 1043 | /* |
3d47e317 | 1044 | * For anonymous folios the only reference left |
6a46079c AK |
1045 | * should be the one m_f() holds. |
1046 | */ | |
3d47e317 | 1047 | if (folio_test_anon(folio)) { |
ea6d0630 NH |
1048 | ret = MF_RECOVERED; |
1049 | goto out; | |
1050 | } | |
6a46079c AK |
1051 | |
1052 | /* | |
1053 | * Now truncate the page in the page cache. This is really | |
1054 | * more like a "temporary hole punch" | |
1055 | * Don't do this for block devices when someone else | |
1056 | * has a reference, because it could be file system metadata | |
1057 | * and that's not safe to truncate. | |
1058 | */ | |
3d47e317 | 1059 | mapping = folio_mapping(folio); |
6a46079c | 1060 | if (!mapping) { |
3d47e317 | 1061 | /* Folio has been torn down in the meantime */ |
ea6d0630 NH |
1062 | ret = MF_FAILED; |
1063 | goto out; | |
6a46079c AK |
1064 | } |
1065 | ||
a7605426 YS |
1066 | /* |
1067 | * The shmem page is kept in page cache instead of truncating | |
1068 | * so is expected to have an extra refcount after error-handling. | |
1069 | */ | |
1070 | extra_pins = shmem_mapping(mapping); | |
1071 | ||
6a46079c AK |
1072 | /* |
1073 | * Truncation is a bit tricky. Enable it per file system for now. | |
1074 | * | |
9608703e | 1075 | * Open: to take i_rwsem or not for this? Right now we don't. |
6a46079c | 1076 | */ |
af7628d6 | 1077 | ret = truncate_error_folio(folio, page_to_pfn(p), mapping); |
a7605426 YS |
1078 | if (has_extra_refcount(ps, p, extra_pins)) |
1079 | ret = MF_FAILED; | |
1080 | ||
ea6d0630 | 1081 | out: |
3d47e317 | 1082 | folio_unlock(folio); |
dd0f230a | 1083 | |
ea6d0630 | 1084 | return ret; |
6a46079c AK |
1085 | } |
1086 | ||
1087 | /* | |
549543df | 1088 | * Dirty pagecache page |
6a46079c AK |
1089 | * Issues: when the error hit a hole page the error is not properly |
1090 | * propagated. | |
1091 | */ | |
dd0f230a | 1092 | static int me_pagecache_dirty(struct page_state *ps, struct page *p) |
6a46079c | 1093 | { |
89f5c54b MWO |
1094 | struct folio *folio = page_folio(p); |
1095 | struct address_space *mapping = folio_mapping(folio); | |
6a46079c AK |
1096 | |
1097 | SetPageError(p); | |
1098 | /* TBD: print more information about the file. */ | |
1099 | if (mapping) { | |
1100 | /* | |
1101 | * IO error will be reported by write(), fsync(), etc. | |
1102 | * who check the mapping. | |
1103 | * This way the application knows that something went | |
1104 | * wrong with its dirty file data. | |
1105 | * | |
1106 | * There's one open issue: | |
1107 | * | |
1108 | * The EIO will be only reported on the next IO | |
1109 | * operation and then cleared through the IO map. | |
1110 | * Normally Linux has two mechanisms to pass IO error | |
1111 | * first through the AS_EIO flag in the address space | |
1112 | * and then through the PageError flag in the page. | |
1113 | * Since we drop pages on memory failure handling the | |
1114 | * only mechanism open to use is through AS_AIO. | |
1115 | * | |
1116 | * This has the disadvantage that it gets cleared on | |
1117 | * the first operation that returns an error, while | |
1118 | * the PageError bit is more sticky and only cleared | |
1119 | * when the page is reread or dropped. If an | |
1120 | * application assumes it will always get error on | |
1121 | * fsync, but does other operations on the fd before | |
25985edc | 1122 | * and the page is dropped between then the error |
6a46079c AK |
1123 | * will not be properly reported. |
1124 | * | |
1125 | * This can already happen even without hwpoisoned | |
1126 | * pages: first on metadata IO errors (which only | |
1127 | * report through AS_EIO) or when the page is dropped | |
1128 | * at the wrong time. | |
1129 | * | |
1130 | * So right now we assume that the application DTRT on | |
1131 | * the first EIO, but we're not worse than other parts | |
1132 | * of the kernel. | |
1133 | */ | |
af21bfaf | 1134 | mapping_set_error(mapping, -EIO); |
6a46079c AK |
1135 | } |
1136 | ||
dd0f230a | 1137 | return me_pagecache_clean(ps, p); |
6a46079c AK |
1138 | } |
1139 | ||
1140 | /* | |
1141 | * Clean and dirty swap cache. | |
1142 | * | |
1143 | * Dirty swap cache page is tricky to handle. The page could live both in page | |
1144 | * cache and swap cache(ie. page is freshly swapped in). So it could be | |
1145 | * referenced concurrently by 2 types of PTEs: | |
1146 | * normal PTEs and swap PTEs. We try to handle them consistently by calling | |
6da6b1d4 | 1147 | * try_to_unmap(!TTU_HWPOISON) to convert the normal PTEs to swap PTEs, |
6a46079c AK |
1148 | * and then |
1149 | * - clear dirty bit to prevent IO | |
1150 | * - remove from LRU | |
1151 | * - but keep in the swap cache, so that when we return to it on | |
1152 | * a later page fault, we know the application is accessing | |
1153 | * corrupted data and shall be killed (we installed simple | |
1154 | * interception code in do_swap_page to catch it). | |
1155 | * | |
1156 | * Clean swap cache pages can be directly isolated. A later page fault will | |
1157 | * bring in the known good data from disk. | |
1158 | */ | |
dd0f230a | 1159 | static int me_swapcache_dirty(struct page_state *ps, struct page *p) |
6a46079c | 1160 | { |
6304b531 | 1161 | struct folio *folio = page_folio(p); |
ea6d0630 | 1162 | int ret; |
dd0f230a | 1163 | bool extra_pins = false; |
ea6d0630 | 1164 | |
6304b531 | 1165 | folio_clear_dirty(folio); |
6a46079c | 1166 | /* Trigger EIO in shmem: */ |
6304b531 | 1167 | folio_clear_uptodate(folio); |
6a46079c | 1168 | |
f7092393 | 1169 | ret = delete_from_lru_cache(folio) ? MF_FAILED : MF_DELAYED; |
6304b531 | 1170 | folio_unlock(folio); |
dd0f230a YS |
1171 | |
1172 | if (ret == MF_DELAYED) | |
1173 | extra_pins = true; | |
1174 | ||
1175 | if (has_extra_refcount(ps, p, extra_pins)) | |
1176 | ret = MF_FAILED; | |
1177 | ||
ea6d0630 | 1178 | return ret; |
6a46079c AK |
1179 | } |
1180 | ||
dd0f230a | 1181 | static int me_swapcache_clean(struct page_state *ps, struct page *p) |
6a46079c | 1182 | { |
75fa68a5 | 1183 | struct folio *folio = page_folio(p); |
ea6d0630 NH |
1184 | int ret; |
1185 | ||
75fa68a5 | 1186 | delete_from_swap_cache(folio); |
e43c3afb | 1187 | |
f7092393 | 1188 | ret = delete_from_lru_cache(folio) ? MF_FAILED : MF_RECOVERED; |
75fa68a5 | 1189 | folio_unlock(folio); |
dd0f230a YS |
1190 | |
1191 | if (has_extra_refcount(ps, p, false)) | |
1192 | ret = MF_FAILED; | |
1193 | ||
ea6d0630 | 1194 | return ret; |
6a46079c AK |
1195 | } |
1196 | ||
1197 | /* | |
1198 | * Huge pages. Needs work. | |
1199 | * Issues: | |
93f70f90 NH |
1200 | * - Error on hugepage is contained in hugepage unit (not in raw page unit.) |
1201 | * To narrow down kill region to one page, we need to break up pmd. | |
6a46079c | 1202 | */ |
dd0f230a | 1203 | static int me_huge_page(struct page_state *ps, struct page *p) |
6a46079c | 1204 | { |
b6fd410c | 1205 | struct folio *folio = page_folio(p); |
a8b2c2ce | 1206 | int res; |
78bb9203 | 1207 | struct address_space *mapping; |
8625147c | 1208 | bool extra_pins = false; |
2491ffee | 1209 | |
b6fd410c | 1210 | mapping = folio_mapping(folio); |
78bb9203 | 1211 | if (mapping) { |
af7628d6 | 1212 | res = truncate_error_folio(folio, page_to_pfn(p), mapping); |
8625147c JH |
1213 | /* The page is kept in page cache. */ |
1214 | extra_pins = true; | |
b6fd410c | 1215 | folio_unlock(folio); |
78bb9203 | 1216 | } else { |
b6fd410c | 1217 | folio_unlock(folio); |
78bb9203 | 1218 | /* |
ef526b17 ML |
1219 | * migration entry prevents later access on error hugepage, |
1220 | * so we can free and dissolve it into buddy to save healthy | |
1221 | * subpages. | |
78bb9203 | 1222 | */ |
b6fd410c | 1223 | folio_put(folio); |
8cf360b9 | 1224 | if (__page_handle_poison(p) > 0) { |
a8b2c2ce OS |
1225 | page_ref_inc(p); |
1226 | res = MF_RECOVERED; | |
ceaf8fbe NH |
1227 | } else { |
1228 | res = MF_FAILED; | |
a8b2c2ce | 1229 | } |
93f70f90 | 1230 | } |
78bb9203 | 1231 | |
8625147c | 1232 | if (has_extra_refcount(ps, p, extra_pins)) |
dd0f230a YS |
1233 | res = MF_FAILED; |
1234 | ||
78bb9203 | 1235 | return res; |
6a46079c AK |
1236 | } |
1237 | ||
1238 | /* | |
1239 | * Various page states we can handle. | |
1240 | * | |
1241 | * A page state is defined by its current page->flags bits. | |
1242 | * The table matches them in order and calls the right handler. | |
1243 | * | |
1244 | * This is quite tricky because we can access page at any time | |
25985edc | 1245 | * in its live cycle, so all accesses have to be extremely careful. |
6a46079c AK |
1246 | * |
1247 | * This is not complete. More states could be added. | |
1248 | * For any missing state don't attempt recovery. | |
1249 | */ | |
1250 | ||
1251 | #define dirty (1UL << PG_dirty) | |
6326fec1 | 1252 | #define sc ((1UL << PG_swapcache) | (1UL << PG_swapbacked)) |
6a46079c AK |
1253 | #define unevict (1UL << PG_unevictable) |
1254 | #define mlock (1UL << PG_mlocked) | |
6a46079c | 1255 | #define lru (1UL << PG_lru) |
6a46079c | 1256 | #define head (1UL << PG_head) |
6a46079c AK |
1257 | #define reserved (1UL << PG_reserved) |
1258 | ||
dd0f230a | 1259 | static struct page_state error_states[] = { |
cc637b17 | 1260 | { reserved, reserved, MF_MSG_KERNEL, me_kernel }, |
95d01fc6 WF |
1261 | /* |
1262 | * free pages are specially detected outside this table: | |
1263 | * PG_buddy pages only make a small fraction of all free pages. | |
1264 | */ | |
6a46079c | 1265 | |
cc637b17 | 1266 | { head, head, MF_MSG_HUGE, me_huge_page }, |
6a46079c | 1267 | |
cc637b17 XX |
1268 | { sc|dirty, sc|dirty, MF_MSG_DIRTY_SWAPCACHE, me_swapcache_dirty }, |
1269 | { sc|dirty, sc, MF_MSG_CLEAN_SWAPCACHE, me_swapcache_clean }, | |
6a46079c | 1270 | |
cc637b17 XX |
1271 | { mlock|dirty, mlock|dirty, MF_MSG_DIRTY_MLOCKED_LRU, me_pagecache_dirty }, |
1272 | { mlock|dirty, mlock, MF_MSG_CLEAN_MLOCKED_LRU, me_pagecache_clean }, | |
6a46079c | 1273 | |
cc637b17 XX |
1274 | { unevict|dirty, unevict|dirty, MF_MSG_DIRTY_UNEVICTABLE_LRU, me_pagecache_dirty }, |
1275 | { unevict|dirty, unevict, MF_MSG_CLEAN_UNEVICTABLE_LRU, me_pagecache_clean }, | |
5f4b9fc5 | 1276 | |
cc637b17 XX |
1277 | { lru|dirty, lru|dirty, MF_MSG_DIRTY_LRU, me_pagecache_dirty }, |
1278 | { lru|dirty, lru, MF_MSG_CLEAN_LRU, me_pagecache_clean }, | |
6a46079c AK |
1279 | |
1280 | /* | |
1281 | * Catchall entry: must be at end. | |
1282 | */ | |
cc637b17 | 1283 | { 0, 0, MF_MSG_UNKNOWN, me_unknown }, |
6a46079c AK |
1284 | }; |
1285 | ||
2326c467 AK |
1286 | #undef dirty |
1287 | #undef sc | |
1288 | #undef unevict | |
1289 | #undef mlock | |
2326c467 | 1290 | #undef lru |
2326c467 | 1291 | #undef head |
2326c467 AK |
1292 | #undef reserved |
1293 | ||
18f41fa6 JY |
1294 | static void update_per_node_mf_stats(unsigned long pfn, |
1295 | enum mf_result result) | |
1296 | { | |
1297 | int nid = MAX_NUMNODES; | |
1298 | struct memory_failure_stats *mf_stats = NULL; | |
1299 | ||
1300 | nid = pfn_to_nid(pfn); | |
1301 | if (unlikely(nid < 0 || nid >= MAX_NUMNODES)) { | |
1302 | WARN_ONCE(1, "Memory failure: pfn=%#lx, invalid nid=%d", pfn, nid); | |
1303 | return; | |
1304 | } | |
1305 | ||
1306 | mf_stats = &NODE_DATA(nid)->mf_stats; | |
1307 | switch (result) { | |
1308 | case MF_IGNORED: | |
1309 | ++mf_stats->ignored; | |
1310 | break; | |
1311 | case MF_FAILED: | |
1312 | ++mf_stats->failed; | |
1313 | break; | |
1314 | case MF_DELAYED: | |
1315 | ++mf_stats->delayed; | |
1316 | break; | |
1317 | case MF_RECOVERED: | |
1318 | ++mf_stats->recovered; | |
1319 | break; | |
1320 | default: | |
1321 | WARN_ONCE(1, "Memory failure: mf_result=%d is not properly handled", result); | |
1322 | break; | |
1323 | } | |
1324 | ++mf_stats->total; | |
1325 | } | |
1326 | ||
ff604cf6 NH |
1327 | /* |
1328 | * "Dirty/Clean" indication is not 100% accurate due to the possibility of | |
1329 | * setting PG_dirty outside page lock. See also comment above set_page_dirty(). | |
1330 | */ | |
b66d00df KW |
1331 | static int action_result(unsigned long pfn, enum mf_action_page_type type, |
1332 | enum mf_result result) | |
6a46079c | 1333 | { |
97f0b134 XX |
1334 | trace_memory_failure_event(pfn, type, result); |
1335 | ||
a46c9304 | 1336 | num_poisoned_pages_inc(pfn); |
18f41fa6 JY |
1337 | |
1338 | update_per_node_mf_stats(pfn, result); | |
1339 | ||
96f96763 | 1340 | pr_err("%#lx: recovery action for %s: %s\n", |
64d37a2b | 1341 | pfn, action_page_types[type], action_name[result]); |
b66d00df KW |
1342 | |
1343 | return (result == MF_RECOVERED || result == MF_DELAYED) ? 0 : -EBUSY; | |
6a46079c AK |
1344 | } |
1345 | ||
1346 | static int page_action(struct page_state *ps, struct page *p, | |
bd1ce5f9 | 1347 | unsigned long pfn) |
6a46079c AK |
1348 | { |
1349 | int result; | |
1350 | ||
ea6d0630 | 1351 | /* page p should be unlocked after returning from ps->action(). */ |
dd0f230a | 1352 | result = ps->action(ps, p); |
7456b040 | 1353 | |
6a46079c AK |
1354 | /* Could do more checks here if page looks ok */ |
1355 | /* | |
1356 | * Could adjust zone counters here to correct for the missing page. | |
1357 | */ | |
1358 | ||
b66d00df | 1359 | return action_result(pfn, ps->type, result); |
6a46079c AK |
1360 | } |
1361 | ||
bf181c58 NH |
1362 | static inline bool PageHWPoisonTakenOff(struct page *page) |
1363 | { | |
1364 | return PageHWPoison(page) && page_private(page) == MAGIC_HWPOISON; | |
1365 | } | |
1366 | ||
1367 | void SetPageHWPoisonTakenOff(struct page *page) | |
1368 | { | |
1369 | set_page_private(page, MAGIC_HWPOISON); | |
1370 | } | |
1371 | ||
1372 | void ClearPageHWPoisonTakenOff(struct page *page) | |
1373 | { | |
1374 | if (PageHWPoison(page)) | |
1375 | set_page_private(page, 0); | |
1376 | } | |
1377 | ||
25182f05 NH |
1378 | /* |
1379 | * Return true if a page type of a given page is supported by hwpoison | |
1380 | * mechanism (while handling could fail), otherwise false. This function | |
1381 | * does not return true for hugetlb or device memory pages, so it's assumed | |
1382 | * to be called only in the context where we never have such pages. | |
1383 | */ | |
bf6445bc | 1384 | static inline bool HWPoisonHandlable(struct page *page, unsigned long flags) |
25182f05 | 1385 | { |
2fde9e7f ML |
1386 | if (PageSlab(page)) |
1387 | return false; | |
1388 | ||
3f871370 | 1389 | /* Soft offline could migrate non-LRU movable pages */ |
bf6445bc | 1390 | if ((flags & MF_SOFT_OFFLINE) && __PageMovable(page)) |
3f871370 | 1391 | return true; |
bf6445bc | 1392 | |
3f871370 | 1393 | return PageLRU(page) || is_free_buddy_page(page); |
25182f05 NH |
1394 | } |
1395 | ||
bf6445bc | 1396 | static int __get_hwpoison_page(struct page *page, unsigned long flags) |
ead07f6a | 1397 | { |
04bac040 | 1398 | struct folio *folio = page_folio(page); |
25182f05 NH |
1399 | int ret = 0; |
1400 | bool hugetlb = false; | |
1401 | ||
04bac040 | 1402 | ret = get_hwpoison_hugetlb_folio(folio, &hugetlb, false); |
d31155b8 ML |
1403 | if (hugetlb) { |
1404 | /* Make sure hugetlb demotion did not happen from under us. */ | |
1405 | if (folio == page_folio(page)) | |
1406 | return ret; | |
1407 | if (ret > 0) { | |
1408 | folio_put(folio); | |
1409 | folio = page_folio(page); | |
1410 | } | |
1411 | } | |
25182f05 NH |
1412 | |
1413 | /* | |
04bac040 SK |
1414 | * This check prevents from calling folio_try_get() for any |
1415 | * unsupported type of folio in order to reduce the risk of unexpected | |
1416 | * races caused by taking a folio refcount. | |
25182f05 | 1417 | */ |
04bac040 | 1418 | if (!HWPoisonHandlable(&folio->page, flags)) |
fcc00621 | 1419 | return -EBUSY; |
ead07f6a | 1420 | |
04bac040 SK |
1421 | if (folio_try_get(folio)) { |
1422 | if (folio == page_folio(page)) | |
c2e7e00b KK |
1423 | return 1; |
1424 | ||
96f96763 | 1425 | pr_info("%#lx cannot catch tail\n", page_to_pfn(page)); |
04bac040 | 1426 | folio_put(folio); |
c2e7e00b KK |
1427 | } |
1428 | ||
1429 | return 0; | |
ead07f6a | 1430 | } |
ead07f6a | 1431 | |
2f714160 | 1432 | static int get_any_page(struct page *p, unsigned long flags) |
17e395b6 | 1433 | { |
2f714160 OS |
1434 | int ret = 0, pass = 0; |
1435 | bool count_increased = false; | |
17e395b6 | 1436 | |
2f714160 OS |
1437 | if (flags & MF_COUNT_INCREASED) |
1438 | count_increased = true; | |
1439 | ||
1440 | try_again: | |
0ed950d1 | 1441 | if (!count_increased) { |
bf6445bc | 1442 | ret = __get_hwpoison_page(p, flags); |
0ed950d1 NH |
1443 | if (!ret) { |
1444 | if (page_count(p)) { | |
1445 | /* We raced with an allocation, retry. */ | |
1446 | if (pass++ < 3) | |
1447 | goto try_again; | |
1448 | ret = -EBUSY; | |
1449 | } else if (!PageHuge(p) && !is_free_buddy_page(p)) { | |
1450 | /* We raced with put_page, retry. */ | |
1451 | if (pass++ < 3) | |
1452 | goto try_again; | |
1453 | ret = -EIO; | |
1454 | } | |
1455 | goto out; | |
1456 | } else if (ret == -EBUSY) { | |
fcc00621 NH |
1457 | /* |
1458 | * We raced with (possibly temporary) unhandlable | |
1459 | * page, retry. | |
1460 | */ | |
1461 | if (pass++ < 3) { | |
d0505e9f | 1462 | shake_page(p); |
2f714160 | 1463 | goto try_again; |
fcc00621 NH |
1464 | } |
1465 | ret = -EIO; | |
0ed950d1 | 1466 | goto out; |
2f714160 | 1467 | } |
0ed950d1 NH |
1468 | } |
1469 | ||
bf6445bc | 1470 | if (PageHuge(p) || HWPoisonHandlable(p, flags)) { |
0ed950d1 | 1471 | ret = 1; |
2f714160 | 1472 | } else { |
0ed950d1 NH |
1473 | /* |
1474 | * A page we cannot handle. Check whether we can turn | |
1475 | * it into something we can handle. | |
1476 | */ | |
1477 | if (pass++ < 3) { | |
2f714160 | 1478 | put_page(p); |
d0505e9f | 1479 | shake_page(p); |
0ed950d1 NH |
1480 | count_increased = false; |
1481 | goto try_again; | |
2f714160 | 1482 | } |
0ed950d1 NH |
1483 | put_page(p); |
1484 | ret = -EIO; | |
17e395b6 | 1485 | } |
0ed950d1 | 1486 | out: |
941ca063 | 1487 | if (ret == -EIO) |
96f96763 | 1488 | pr_err("%#lx: unhandlable page.\n", page_to_pfn(p)); |
941ca063 | 1489 | |
17e395b6 OS |
1490 | return ret; |
1491 | } | |
1492 | ||
bf181c58 NH |
1493 | static int __get_unpoison_page(struct page *page) |
1494 | { | |
04bac040 | 1495 | struct folio *folio = page_folio(page); |
bf181c58 NH |
1496 | int ret = 0; |
1497 | bool hugetlb = false; | |
1498 | ||
04bac040 | 1499 | ret = get_hwpoison_hugetlb_folio(folio, &hugetlb, true); |
d31155b8 ML |
1500 | if (hugetlb) { |
1501 | /* Make sure hugetlb demotion did not happen from under us. */ | |
1502 | if (folio == page_folio(page)) | |
1503 | return ret; | |
1504 | if (ret > 0) | |
1505 | folio_put(folio); | |
1506 | } | |
bf181c58 NH |
1507 | |
1508 | /* | |
1509 | * PageHWPoisonTakenOff pages are not only marked as PG_hwpoison, | |
1510 | * but also isolated from buddy freelist, so need to identify the | |
1511 | * state and have to cancel both operations to unpoison. | |
1512 | */ | |
1513 | if (PageHWPoisonTakenOff(page)) | |
1514 | return -EHWPOISON; | |
1515 | ||
1516 | return get_page_unless_zero(page) ? 1 : 0; | |
1517 | } | |
1518 | ||
0ed950d1 NH |
1519 | /** |
1520 | * get_hwpoison_page() - Get refcount for memory error handling | |
1521 | * @p: Raw error page (hit by memory error) | |
1522 | * @flags: Flags controlling behavior of error handling | |
1523 | * | |
1524 | * get_hwpoison_page() takes a page refcount of an error page to handle memory | |
1525 | * error on it, after checking that the error page is in a well-defined state | |
0b8f0d87 | 1526 | * (defined as a page-type we can successfully handle the memory error on it, |
0ed950d1 NH |
1527 | * such as LRU page and hugetlb page). |
1528 | * | |
1529 | * Memory error handling could be triggered at any time on any type of page, | |
1530 | * so it's prone to race with typical memory management lifecycle (like | |
1531 | * allocation and free). So to avoid such races, get_hwpoison_page() takes | |
1532 | * extra care for the error page's state (as done in __get_hwpoison_page()), | |
1533 | * and has some retry logic in get_any_page(). | |
1534 | * | |
bf181c58 NH |
1535 | * When called from unpoison_memory(), the caller should already ensure that |
1536 | * the given page has PG_hwpoison. So it's never reused for other page | |
1537 | * allocations, and __get_unpoison_page() never races with them. | |
1538 | * | |
0ed950d1 NH |
1539 | * Return: 0 on failure, |
1540 | * 1 on success for in-use pages in a well-defined state, | |
1541 | * -EIO for pages on which we can not handle memory errors, | |
1542 | * -EBUSY when get_hwpoison_page() has raced with page lifecycle | |
bf181c58 NH |
1543 | * operations like allocation and free, |
1544 | * -EHWPOISON when the page is hwpoisoned and taken off from buddy. | |
0ed950d1 NH |
1545 | */ |
1546 | static int get_hwpoison_page(struct page *p, unsigned long flags) | |
2f714160 OS |
1547 | { |
1548 | int ret; | |
1549 | ||
1550 | zone_pcp_disable(page_zone(p)); | |
bf181c58 NH |
1551 | if (flags & MF_UNPOISON) |
1552 | ret = __get_unpoison_page(p); | |
1553 | else | |
1554 | ret = get_any_page(p, flags); | |
2f714160 OS |
1555 | zone_pcp_enable(page_zone(p)); |
1556 | ||
1557 | return ret; | |
1558 | } | |
1559 | ||
6a46079c AK |
1560 | /* |
1561 | * Do all that is necessary to remove user space mappings. Unmap | |
1562 | * the pages and send SIGBUS to the processes if the data was dirty. | |
1563 | */ | |
03468a0f MWO |
1564 | static bool hwpoison_user_mappings(struct folio *folio, struct page *p, |
1565 | unsigned long pfn, int flags) | |
6a46079c | 1566 | { |
6da6b1d4 | 1567 | enum ttu_flags ttu = TTU_IGNORE_MLOCK | TTU_SYNC | TTU_HWPOISON; |
6a46079c AK |
1568 | struct address_space *mapping; |
1569 | LIST_HEAD(tokill); | |
1fb08ac6 | 1570 | bool unmap_success; |
0792a4a6 | 1571 | int forcekill; |
03468a0f | 1572 | bool mlocked = folio_test_mlocked(folio); |
6a46079c | 1573 | |
93a9eb39 NH |
1574 | /* |
1575 | * Here we are interested only in user-mapped pages, so skip any | |
1576 | * other types of pages. | |
1577 | */ | |
03468a0f MWO |
1578 | if (folio_test_reserved(folio) || folio_test_slab(folio) || |
1579 | folio_test_pgtable(folio) || folio_test_offline(folio)) | |
666e5a40 | 1580 | return true; |
03468a0f | 1581 | if (!(folio_test_lru(folio) || folio_test_hugetlb(folio))) |
666e5a40 | 1582 | return true; |
6a46079c | 1583 | |
6a46079c AK |
1584 | /* |
1585 | * This check implies we don't kill processes if their pages | |
1586 | * are in the swap cache early. Those are always late kills. | |
1587 | */ | |
c79c5a0a | 1588 | if (!page_mapped(p)) |
666e5a40 | 1589 | return true; |
1668bfd5 | 1590 | |
03468a0f | 1591 | if (folio_test_swapcache(folio)) { |
96f96763 | 1592 | pr_err("%#lx: keeping poisoned page in swap cache\n", pfn); |
6da6b1d4 | 1593 | ttu &= ~TTU_HWPOISON; |
6a46079c AK |
1594 | } |
1595 | ||
1596 | /* | |
1597 | * Propagate the dirty bit from PTEs to struct page first, because we | |
1598 | * need this to decide if we should kill or just drop the page. | |
db0480b3 WF |
1599 | * XXX: the dirty test could be racy: set_page_dirty() may not always |
1600 | * be called inside page lock (it's recommended but not enforced). | |
6a46079c | 1601 | */ |
03468a0f MWO |
1602 | mapping = folio_mapping(folio); |
1603 | if (!(flags & MF_MUST_KILL) && !folio_test_dirty(folio) && mapping && | |
f56753ac | 1604 | mapping_can_writeback(mapping)) { |
03468a0f MWO |
1605 | if (folio_mkclean(folio)) { |
1606 | folio_set_dirty(folio); | |
6a46079c | 1607 | } else { |
6da6b1d4 | 1608 | ttu &= ~TTU_HWPOISON; |
96f96763 | 1609 | pr_info("%#lx: corrupted page was clean: dropped without side effects\n", |
6a46079c AK |
1610 | pfn); |
1611 | } | |
1612 | } | |
1613 | ||
1614 | /* | |
1615 | * First collect all the processes that have the page | |
1616 | * mapped in dirty form. This has to be done before try_to_unmap, | |
1617 | * because ttu takes the rmap data structures down. | |
6a46079c | 1618 | */ |
376907f3 | 1619 | collect_procs(folio, p, &tokill, flags & MF_ACTION_REQUIRED); |
6a46079c | 1620 | |
03468a0f | 1621 | if (folio_test_hugetlb(folio) && !folio_test_anon(folio)) { |
357670f7 ML |
1622 | /* |
1623 | * For hugetlb pages in shared mappings, try_to_unmap | |
1624 | * could potentially call huge_pmd_unshare. Because of | |
1625 | * this, take semaphore in write mode here and set | |
1626 | * TTU_RMAP_LOCKED to indicate we have taken the lock | |
1627 | * at this higher level. | |
1628 | */ | |
6e8cda4c | 1629 | mapping = hugetlb_folio_mapping_lock_write(folio); |
357670f7 | 1630 | if (mapping) { |
9030fb0b | 1631 | try_to_unmap(folio, ttu|TTU_RMAP_LOCKED); |
357670f7 ML |
1632 | i_mmap_unlock_write(mapping); |
1633 | } else | |
96f96763 | 1634 | pr_info("%#lx: could not lock mapping for mapped huge page\n", pfn); |
c0d0381a | 1635 | } else { |
9030fb0b | 1636 | try_to_unmap(folio, ttu); |
c0d0381a | 1637 | } |
1fb08ac6 | 1638 | |
c79c5a0a | 1639 | unmap_success = !page_mapped(p); |
666e5a40 | 1640 | if (!unmap_success) |
33d844bb DH |
1641 | pr_err("%#lx: failed to unmap page (folio mapcount=%d)\n", |
1642 | pfn, folio_mapcount(page_folio(p))); | |
a6d30ddd | 1643 | |
286c469a NH |
1644 | /* |
1645 | * try_to_unmap() might put mlocked page in lru cache, so call | |
1646 | * shake_page() again to ensure that it's flushed. | |
1647 | */ | |
1648 | if (mlocked) | |
fed5348e | 1649 | shake_folio(folio); |
286c469a | 1650 | |
6a46079c AK |
1651 | /* |
1652 | * Now that the dirty bit has been propagated to the | |
1653 | * struct page and all unmaps done we can decide if | |
1654 | * killing is needed or not. Only kill when the page | |
6751ed65 TL |
1655 | * was dirty or the process is not restartable, |
1656 | * otherwise the tokill list is merely | |
6a46079c AK |
1657 | * freed. When there was a problem unmapping earlier |
1658 | * use a more force-full uncatchable kill to prevent | |
1659 | * any accesses to the poisoned memory. | |
1660 | */ | |
03468a0f | 1661 | forcekill = folio_test_dirty(folio) || (flags & MF_MUST_KILL) || |
0792a4a6 | 1662 | !unmap_success; |
ae1139ec | 1663 | kill_procs(&tokill, forcekill, !unmap_success, pfn, flags); |
1668bfd5 | 1664 | |
666e5a40 | 1665 | return unmap_success; |
6a46079c AK |
1666 | } |
1667 | ||
0348d2eb NH |
1668 | static int identify_page_state(unsigned long pfn, struct page *p, |
1669 | unsigned long page_flags) | |
761ad8d7 NH |
1670 | { |
1671 | struct page_state *ps; | |
0348d2eb NH |
1672 | |
1673 | /* | |
1674 | * The first check uses the current page flags which may not have any | |
1675 | * relevant information. The second check with the saved page flags is | |
1676 | * carried out only if the first check can't determine the page status. | |
1677 | */ | |
1678 | for (ps = error_states;; ps++) | |
1679 | if ((p->flags & ps->mask) == ps->res) | |
1680 | break; | |
1681 | ||
1682 | page_flags |= (p->flags & (1UL << PG_dirty)); | |
1683 | ||
1684 | if (!ps->mask) | |
1685 | for (ps = error_states;; ps++) | |
1686 | if ((page_flags & ps->mask) == ps->res) | |
1687 | break; | |
1688 | return page_action(ps, p, pfn); | |
1689 | } | |
1690 | ||
2ace36f0 | 1691 | static int try_to_split_thp_page(struct page *page) |
694bf0b0 | 1692 | { |
2ace36f0 KW |
1693 | int ret; |
1694 | ||
694bf0b0 | 1695 | lock_page(page); |
2ace36f0 KW |
1696 | ret = split_huge_page(page); |
1697 | unlock_page(page); | |
694bf0b0 | 1698 | |
2ace36f0 | 1699 | if (unlikely(ret)) |
694bf0b0 | 1700 | put_page(page); |
694bf0b0 | 1701 | |
2ace36f0 | 1702 | return ret; |
694bf0b0 OS |
1703 | } |
1704 | ||
00cc790e SR |
1705 | static void unmap_and_kill(struct list_head *to_kill, unsigned long pfn, |
1706 | struct address_space *mapping, pgoff_t index, int flags) | |
1707 | { | |
1708 | struct to_kill *tk; | |
1709 | unsigned long size = 0; | |
1710 | ||
1711 | list_for_each_entry(tk, to_kill, nd) | |
1712 | if (tk->size_shift) | |
1713 | size = max(size, 1UL << tk->size_shift); | |
1714 | ||
1715 | if (size) { | |
1716 | /* | |
1717 | * Unmap the largest mapping to avoid breaking up device-dax | |
1718 | * mappings which are constant size. The actual size of the | |
1719 | * mapping being torn down is communicated in siginfo, see | |
1720 | * kill_proc() | |
1721 | */ | |
39ebd6dc | 1722 | loff_t start = ((loff_t)index << PAGE_SHIFT) & ~(size - 1); |
00cc790e SR |
1723 | |
1724 | unmap_mapping_range(mapping, start, size, 0); | |
1725 | } | |
1726 | ||
1727 | kill_procs(to_kill, flags & MF_MUST_KILL, false, pfn, flags); | |
1728 | } | |
1729 | ||
91e79d22 MWO |
1730 | /* |
1731 | * Only dev_pagemap pages get here, such as fsdax when the filesystem | |
1732 | * either do not claim or fails to claim a hwpoison event, or devdax. | |
1733 | * The fsdax pages are initialized per base page, and the devdax pages | |
1734 | * could be initialized either as base pages, or as compound pages with | |
1735 | * vmemmap optimization enabled. Devdax is simplistic in its dealing with | |
1736 | * hwpoison, such that, if a subpage of a compound page is poisoned, | |
1737 | * simply mark the compound head page is by far sufficient. | |
1738 | */ | |
00cc790e SR |
1739 | static int mf_generic_kill_procs(unsigned long long pfn, int flags, |
1740 | struct dev_pagemap *pgmap) | |
1741 | { | |
91e79d22 | 1742 | struct folio *folio = pfn_folio(pfn); |
00cc790e SR |
1743 | LIST_HEAD(to_kill); |
1744 | dax_entry_t cookie; | |
1745 | int rc = 0; | |
1746 | ||
00cc790e SR |
1747 | /* |
1748 | * Prevent the inode from being freed while we are interrogating | |
1749 | * the address_space, typically this would be handled by | |
1750 | * lock_page(), but dax pages do not use the page lock. This | |
1751 | * also prevents changes to the mapping of this pfn until | |
1752 | * poison signaling is complete. | |
1753 | */ | |
91e79d22 | 1754 | cookie = dax_lock_folio(folio); |
00cc790e SR |
1755 | if (!cookie) |
1756 | return -EBUSY; | |
1757 | ||
91e79d22 | 1758 | if (hwpoison_filter(&folio->page)) { |
00cc790e SR |
1759 | rc = -EOPNOTSUPP; |
1760 | goto unlock; | |
1761 | } | |
1762 | ||
1763 | switch (pgmap->type) { | |
1764 | case MEMORY_DEVICE_PRIVATE: | |
1765 | case MEMORY_DEVICE_COHERENT: | |
1766 | /* | |
1767 | * TODO: Handle device pages which may need coordination | |
1768 | * with device-side memory. | |
1769 | */ | |
1770 | rc = -ENXIO; | |
1771 | goto unlock; | |
1772 | default: | |
1773 | break; | |
1774 | } | |
1775 | ||
1776 | /* | |
1777 | * Use this flag as an indication that the dax page has been | |
1778 | * remapped UC to prevent speculative consumption of poison. | |
1779 | */ | |
91e79d22 | 1780 | SetPageHWPoison(&folio->page); |
00cc790e SR |
1781 | |
1782 | /* | |
1783 | * Unlike System-RAM there is no possibility to swap in a | |
1784 | * different physical page at a given virtual address, so all | |
1785 | * userspace consumption of ZONE_DEVICE memory necessitates | |
1786 | * SIGBUS (i.e. MF_MUST_KILL) | |
1787 | */ | |
1788 | flags |= MF_ACTION_REQUIRED | MF_MUST_KILL; | |
376907f3 | 1789 | collect_procs(folio, &folio->page, &to_kill, true); |
00cc790e | 1790 | |
91e79d22 | 1791 | unmap_and_kill(&to_kill, pfn, folio->mapping, folio->index, flags); |
00cc790e | 1792 | unlock: |
91e79d22 | 1793 | dax_unlock_folio(folio, cookie); |
00cc790e SR |
1794 | return rc; |
1795 | } | |
1796 | ||
c36e2024 SR |
1797 | #ifdef CONFIG_FS_DAX |
1798 | /** | |
1799 | * mf_dax_kill_procs - Collect and kill processes who are using this file range | |
1800 | * @mapping: address_space of the file in use | |
1801 | * @index: start pgoff of the range within the file | |
1802 | * @count: length of the range, in unit of PAGE_SIZE | |
1803 | * @mf_flags: memory failure flags | |
1804 | */ | |
1805 | int mf_dax_kill_procs(struct address_space *mapping, pgoff_t index, | |
1806 | unsigned long count, int mf_flags) | |
1807 | { | |
1808 | LIST_HEAD(to_kill); | |
1809 | dax_entry_t cookie; | |
1810 | struct page *page; | |
1811 | size_t end = index + count; | |
fa422b35 | 1812 | bool pre_remove = mf_flags & MF_MEM_PRE_REMOVE; |
c36e2024 SR |
1813 | |
1814 | mf_flags |= MF_ACTION_REQUIRED | MF_MUST_KILL; | |
1815 | ||
1816 | for (; index < end; index++) { | |
1817 | page = NULL; | |
1818 | cookie = dax_lock_mapping_entry(mapping, index, &page); | |
1819 | if (!cookie) | |
1820 | return -EBUSY; | |
1821 | if (!page) | |
1822 | goto unlock; | |
1823 | ||
fa422b35 SR |
1824 | if (!pre_remove) |
1825 | SetPageHWPoison(page); | |
c36e2024 | 1826 | |
fa422b35 SR |
1827 | /* |
1828 | * The pre_remove case is revoking access, the memory is still | |
1829 | * good and could theoretically be put back into service. | |
1830 | */ | |
1831 | collect_procs_fsdax(page, mapping, index, &to_kill, pre_remove); | |
c36e2024 SR |
1832 | unmap_and_kill(&to_kill, page_to_pfn(page), mapping, |
1833 | index, mf_flags); | |
1834 | unlock: | |
1835 | dax_unlock_mapping_entry(mapping, index, cookie); | |
1836 | } | |
1837 | return 0; | |
1838 | } | |
1839 | EXPORT_SYMBOL_GPL(mf_dax_kill_procs); | |
1840 | #endif /* CONFIG_FS_DAX */ | |
1841 | ||
161df60e | 1842 | #ifdef CONFIG_HUGETLB_PAGE |
b79f8eb4 | 1843 | |
161df60e NH |
1844 | /* |
1845 | * Struct raw_hwp_page represents information about "raw error page", | |
dad6a5eb | 1846 | * constructing singly linked list from ->_hugetlb_hwpoison field of folio. |
161df60e NH |
1847 | */ |
1848 | struct raw_hwp_page { | |
1849 | struct llist_node node; | |
1850 | struct page *page; | |
1851 | }; | |
1852 | ||
b02e7582 | 1853 | static inline struct llist_head *raw_hwp_list_head(struct folio *folio) |
161df60e | 1854 | { |
b02e7582 | 1855 | return (struct llist_head *)&folio->_hugetlb_hwpoison; |
161df60e NH |
1856 | } |
1857 | ||
b79f8eb4 JY |
1858 | bool is_raw_hwpoison_page_in_hugepage(struct page *page) |
1859 | { | |
1860 | struct llist_head *raw_hwp_head; | |
1861 | struct raw_hwp_page *p; | |
1862 | struct folio *folio = page_folio(page); | |
1863 | bool ret = false; | |
1864 | ||
1865 | if (!folio_test_hwpoison(folio)) | |
1866 | return false; | |
1867 | ||
1868 | if (!folio_test_hugetlb(folio)) | |
1869 | return PageHWPoison(page); | |
1870 | ||
1871 | /* | |
1872 | * When RawHwpUnreliable is set, kernel lost track of which subpages | |
1873 | * are HWPOISON. So return as if ALL subpages are HWPOISONed. | |
1874 | */ | |
1875 | if (folio_test_hugetlb_raw_hwp_unreliable(folio)) | |
1876 | return true; | |
1877 | ||
1878 | mutex_lock(&mf_mutex); | |
1879 | ||
1880 | raw_hwp_head = raw_hwp_list_head(folio); | |
1881 | llist_for_each_entry(p, raw_hwp_head->first, node) { | |
1882 | if (page == p->page) { | |
1883 | ret = true; | |
1884 | break; | |
1885 | } | |
1886 | } | |
1887 | ||
1888 | mutex_unlock(&mf_mutex); | |
1889 | ||
1890 | return ret; | |
1891 | } | |
1892 | ||
0858b5eb | 1893 | static unsigned long __folio_free_raw_hwp(struct folio *folio, bool move_flag) |
161df60e | 1894 | { |
6379693e ML |
1895 | struct llist_node *head; |
1896 | struct raw_hwp_page *p, *next; | |
ac5fcde0 | 1897 | unsigned long count = 0; |
161df60e | 1898 | |
9e130c4b | 1899 | head = llist_del_all(raw_hwp_list_head(folio)); |
6379693e | 1900 | llist_for_each_entry_safe(p, next, head, node) { |
ac5fcde0 NH |
1901 | if (move_flag) |
1902 | SetPageHWPoison(p->page); | |
5033091d NH |
1903 | else |
1904 | num_poisoned_pages_sub(page_to_pfn(p->page), 1); | |
161df60e | 1905 | kfree(p); |
ac5fcde0 | 1906 | count++; |
161df60e | 1907 | } |
ac5fcde0 | 1908 | return count; |
161df60e NH |
1909 | } |
1910 | ||
595dd818 | 1911 | static int folio_set_hugetlb_hwpoison(struct folio *folio, struct page *page) |
161df60e NH |
1912 | { |
1913 | struct llist_head *head; | |
1914 | struct raw_hwp_page *raw_hwp; | |
6379693e | 1915 | struct raw_hwp_page *p, *next; |
595dd818 | 1916 | int ret = folio_test_set_hwpoison(folio) ? -EHWPOISON : 0; |
161df60e NH |
1917 | |
1918 | /* | |
1919 | * Once the hwpoison hugepage has lost reliable raw error info, | |
1920 | * there is little meaning to keep additional error info precisely, | |
1921 | * so skip to add additional raw error info. | |
1922 | */ | |
b02e7582 | 1923 | if (folio_test_hugetlb_raw_hwp_unreliable(folio)) |
161df60e | 1924 | return -EHWPOISON; |
b02e7582 | 1925 | head = raw_hwp_list_head(folio); |
6379693e | 1926 | llist_for_each_entry_safe(p, next, head->first, node) { |
161df60e NH |
1927 | if (p->page == page) |
1928 | return -EHWPOISON; | |
1929 | } | |
1930 | ||
1931 | raw_hwp = kmalloc(sizeof(struct raw_hwp_page), GFP_ATOMIC); | |
1932 | if (raw_hwp) { | |
1933 | raw_hwp->page = page; | |
1934 | llist_add(&raw_hwp->node, head); | |
1935 | /* the first error event will be counted in action_result(). */ | |
1936 | if (ret) | |
a46c9304 | 1937 | num_poisoned_pages_inc(page_to_pfn(page)); |
161df60e NH |
1938 | } else { |
1939 | /* | |
1940 | * Failed to save raw error info. We no longer trace all | |
1941 | * hwpoisoned subpages, and we need refuse to free/dissolve | |
1942 | * this hwpoisoned hugepage. | |
1943 | */ | |
b02e7582 | 1944 | folio_set_hugetlb_raw_hwp_unreliable(folio); |
161df60e | 1945 | /* |
b02e7582 | 1946 | * Once hugetlb_raw_hwp_unreliable is set, raw_hwp_page is not |
161df60e NH |
1947 | * used any more, so free it. |
1948 | */ | |
0858b5eb | 1949 | __folio_free_raw_hwp(folio, false); |
161df60e NH |
1950 | } |
1951 | return ret; | |
1952 | } | |
1953 | ||
9637d7df | 1954 | static unsigned long folio_free_raw_hwp(struct folio *folio, bool move_flag) |
ac5fcde0 NH |
1955 | { |
1956 | /* | |
9637d7df | 1957 | * hugetlb_vmemmap_optimized hugepages can't be freed because struct |
ac5fcde0 NH |
1958 | * pages for tail pages are required but they don't exist. |
1959 | */ | |
9637d7df | 1960 | if (move_flag && folio_test_hugetlb_vmemmap_optimized(folio)) |
ac5fcde0 NH |
1961 | return 0; |
1962 | ||
1963 | /* | |
9637d7df | 1964 | * hugetlb_raw_hwp_unreliable hugepages shouldn't be unpoisoned by |
ac5fcde0 NH |
1965 | * definition. |
1966 | */ | |
9637d7df | 1967 | if (folio_test_hugetlb_raw_hwp_unreliable(folio)) |
ac5fcde0 NH |
1968 | return 0; |
1969 | ||
0858b5eb | 1970 | return __folio_free_raw_hwp(folio, move_flag); |
ac5fcde0 NH |
1971 | } |
1972 | ||
2ff6cece | 1973 | void folio_clear_hugetlb_hwpoison(struct folio *folio) |
161df60e | 1974 | { |
2ff6cece | 1975 | if (folio_test_hugetlb_raw_hwp_unreliable(folio)) |
161df60e | 1976 | return; |
92a025a7 ML |
1977 | if (folio_test_hugetlb_vmemmap_optimized(folio)) |
1978 | return; | |
2ff6cece | 1979 | folio_clear_hwpoison(folio); |
9637d7df | 1980 | folio_free_raw_hwp(folio, true); |
161df60e NH |
1981 | } |
1982 | ||
405ce051 NH |
1983 | /* |
1984 | * Called from hugetlb code with hugetlb_lock held. | |
1985 | * | |
1986 | * Return values: | |
1987 | * 0 - free hugepage | |
1988 | * 1 - in-use hugepage | |
1989 | * 2 - not a hugepage | |
1990 | * -EBUSY - the hugepage is busy (try to retry) | |
1991 | * -EHWPOISON - the hugepage is already hwpoisoned | |
1992 | */ | |
e591ef7d NH |
1993 | int __get_huge_page_for_hwpoison(unsigned long pfn, int flags, |
1994 | bool *migratable_cleared) | |
405ce051 NH |
1995 | { |
1996 | struct page *page = pfn_to_page(pfn); | |
4c110ec9 | 1997 | struct folio *folio = page_folio(page); |
405ce051 NH |
1998 | int ret = 2; /* fallback to normal page handling */ |
1999 | bool count_increased = false; | |
2000 | ||
4c110ec9 | 2001 | if (!folio_test_hugetlb(folio)) |
405ce051 NH |
2002 | goto out; |
2003 | ||
2004 | if (flags & MF_COUNT_INCREASED) { | |
2005 | ret = 1; | |
2006 | count_increased = true; | |
4c110ec9 | 2007 | } else if (folio_test_hugetlb_freed(folio)) { |
b283d983 | 2008 | ret = 0; |
4c110ec9 SK |
2009 | } else if (folio_test_hugetlb_migratable(folio)) { |
2010 | ret = folio_try_get(folio); | |
405ce051 NH |
2011 | if (ret) |
2012 | count_increased = true; | |
2013 | } else { | |
2014 | ret = -EBUSY; | |
38f6d293 NH |
2015 | if (!(flags & MF_NO_RETRY)) |
2016 | goto out; | |
405ce051 NH |
2017 | } |
2018 | ||
595dd818 | 2019 | if (folio_set_hugetlb_hwpoison(folio, page)) { |
405ce051 NH |
2020 | ret = -EHWPOISON; |
2021 | goto out; | |
2022 | } | |
2023 | ||
e591ef7d | 2024 | /* |
4c110ec9 | 2025 | * Clearing hugetlb_migratable for hwpoisoned hugepages to prevent them |
e591ef7d NH |
2026 | * from being migrated by memory hotremove. |
2027 | */ | |
4c110ec9 SK |
2028 | if (count_increased && folio_test_hugetlb_migratable(folio)) { |
2029 | folio_clear_hugetlb_migratable(folio); | |
e591ef7d NH |
2030 | *migratable_cleared = true; |
2031 | } | |
2032 | ||
405ce051 NH |
2033 | return ret; |
2034 | out: | |
2035 | if (count_increased) | |
4c110ec9 | 2036 | folio_put(folio); |
405ce051 NH |
2037 | return ret; |
2038 | } | |
2039 | ||
405ce051 NH |
2040 | /* |
2041 | * Taking refcount of hugetlb pages needs extra care about race conditions | |
2042 | * with basic operations like hugepage allocation/free/demotion. | |
2043 | * So some of prechecks for hwpoison (pinning, and testing/setting | |
2044 | * PageHWPoison) should be done in single hugetlb_lock range. | |
2045 | */ | |
2046 | static int try_memory_failure_hugetlb(unsigned long pfn, int flags, int *hugetlb) | |
0348d2eb | 2047 | { |
761ad8d7 | 2048 | int res; |
405ce051 | 2049 | struct page *p = pfn_to_page(pfn); |
bc1cfde1 | 2050 | struct folio *folio; |
761ad8d7 | 2051 | unsigned long page_flags; |
e591ef7d | 2052 | bool migratable_cleared = false; |
761ad8d7 | 2053 | |
405ce051 NH |
2054 | *hugetlb = 1; |
2055 | retry: | |
e591ef7d | 2056 | res = get_huge_page_for_hwpoison(pfn, flags, &migratable_cleared); |
405ce051 NH |
2057 | if (res == 2) { /* fallback to normal page handling */ |
2058 | *hugetlb = 0; | |
2059 | return 0; | |
2060 | } else if (res == -EHWPOISON) { | |
96f96763 | 2061 | pr_err("%#lx: already hardware poisoned\n", pfn); |
405ce051 | 2062 | if (flags & MF_ACTION_REQUIRED) { |
bc1cfde1 SK |
2063 | folio = page_folio(p); |
2064 | res = kill_accessing_process(current, folio_pfn(folio), flags); | |
405ce051 NH |
2065 | } |
2066 | return res; | |
2067 | } else if (res == -EBUSY) { | |
38f6d293 NH |
2068 | if (!(flags & MF_NO_RETRY)) { |
2069 | flags |= MF_NO_RETRY; | |
405ce051 NH |
2070 | goto retry; |
2071 | } | |
b66d00df | 2072 | return action_result(pfn, MF_MSG_UNKNOWN, MF_IGNORED); |
761ad8d7 NH |
2073 | } |
2074 | ||
bc1cfde1 SK |
2075 | folio = page_folio(p); |
2076 | folio_lock(folio); | |
405ce051 NH |
2077 | |
2078 | if (hwpoison_filter(p)) { | |
2ff6cece | 2079 | folio_clear_hugetlb_hwpoison(folio); |
e591ef7d | 2080 | if (migratable_cleared) |
bc1cfde1 SK |
2081 | folio_set_hugetlb_migratable(folio); |
2082 | folio_unlock(folio); | |
f36a5543 | 2083 | if (res == 1) |
bc1cfde1 | 2084 | folio_put(folio); |
f36a5543 | 2085 | return -EOPNOTSUPP; |
405ce051 NH |
2086 | } |
2087 | ||
405ce051 NH |
2088 | /* |
2089 | * Handling free hugepage. The possible race with hugepage allocation | |
2090 | * or demotion can be prevented by PageHWPoison flag. | |
2091 | */ | |
2092 | if (res == 0) { | |
bc1cfde1 | 2093 | folio_unlock(folio); |
8cf360b9 | 2094 | if (__page_handle_poison(p) > 0) { |
405ce051 NH |
2095 | page_ref_inc(p); |
2096 | res = MF_RECOVERED; | |
ceaf8fbe NH |
2097 | } else { |
2098 | res = MF_FAILED; | |
761ad8d7 | 2099 | } |
b66d00df | 2100 | return action_result(pfn, MF_MSG_FREE_HUGE, res); |
761ad8d7 NH |
2101 | } |
2102 | ||
bc1cfde1 | 2103 | page_flags = folio->flags; |
761ad8d7 | 2104 | |
03468a0f | 2105 | if (!hwpoison_user_mappings(folio, p, pfn, flags)) { |
bc1cfde1 | 2106 | folio_unlock(folio); |
b66d00df | 2107 | return action_result(pfn, MF_MSG_UNMAP_FAILED, MF_IGNORED); |
761ad8d7 NH |
2108 | } |
2109 | ||
ea6d0630 | 2110 | return identify_page_state(pfn, p, page_flags); |
761ad8d7 | 2111 | } |
00cc790e | 2112 | |
405ce051 NH |
2113 | #else |
2114 | static inline int try_memory_failure_hugetlb(unsigned long pfn, int flags, int *hugetlb) | |
2115 | { | |
2116 | return 0; | |
2117 | } | |
00cc790e | 2118 | |
9637d7df | 2119 | static inline unsigned long folio_free_raw_hwp(struct folio *folio, bool flag) |
ac5fcde0 NH |
2120 | { |
2121 | return 0; | |
2122 | } | |
00cc790e | 2123 | #endif /* CONFIG_HUGETLB_PAGE */ |
761ad8d7 | 2124 | |
b5f1fc98 KW |
2125 | /* Drop the extra refcount in case we come from madvise() */ |
2126 | static void put_ref_page(unsigned long pfn, int flags) | |
2127 | { | |
2128 | struct page *page; | |
2129 | ||
2130 | if (!(flags & MF_COUNT_INCREASED)) | |
2131 | return; | |
2132 | ||
2133 | page = pfn_to_page(pfn); | |
2134 | if (page) | |
2135 | put_page(page); | |
2136 | } | |
2137 | ||
6100e34b DW |
2138 | static int memory_failure_dev_pagemap(unsigned long pfn, int flags, |
2139 | struct dev_pagemap *pgmap) | |
2140 | { | |
00cc790e | 2141 | int rc = -ENXIO; |
6100e34b | 2142 | |
34dc45be | 2143 | /* device metadata space is not recoverable */ |
00cc790e | 2144 | if (!pgmap_pfn_valid(pgmap, pfn)) |
34dc45be | 2145 | goto out; |
61e28cf0 | 2146 | |
6100e34b | 2147 | /* |
33a8f7f2 SR |
2148 | * Call driver's implementation to handle the memory failure, otherwise |
2149 | * fall back to generic handler. | |
6100e34b | 2150 | */ |
65d3440e | 2151 | if (pgmap_has_memory_failure(pgmap)) { |
33a8f7f2 | 2152 | rc = pgmap->ops->memory_failure(pgmap, pfn, 1, flags); |
6100e34b | 2153 | /* |
33a8f7f2 SR |
2154 | * Fall back to generic handler too if operation is not |
2155 | * supported inside the driver/device/filesystem. | |
6100e34b | 2156 | */ |
33a8f7f2 SR |
2157 | if (rc != -EOPNOTSUPP) |
2158 | goto out; | |
6100e34b DW |
2159 | } |
2160 | ||
00cc790e | 2161 | rc = mf_generic_kill_procs(pfn, flags, pgmap); |
6100e34b DW |
2162 | out: |
2163 | /* drop pgmap ref acquired in caller */ | |
2164 | put_dev_pagemap(pgmap); | |
80ee7cb2 ML |
2165 | if (rc != -EOPNOTSUPP) |
2166 | action_result(pfn, MF_MSG_DAX, rc ? MF_FAILED : MF_RECOVERED); | |
6100e34b DW |
2167 | return rc; |
2168 | } | |
2169 | ||
cd42f4a3 TL |
2170 | /** |
2171 | * memory_failure - Handle memory failure of a page. | |
2172 | * @pfn: Page Number of the corrupted page | |
cd42f4a3 TL |
2173 | * @flags: fine tune action taken |
2174 | * | |
2175 | * This function is called by the low level machine check code | |
2176 | * of an architecture when it detects hardware memory corruption | |
2177 | * of a page. It tries its best to recover, which includes | |
2178 | * dropping pages, killing processes etc. | |
2179 | * | |
2180 | * The function is primarily of use for corruptions that | |
2181 | * happen outside the current execution context (e.g. when | |
2182 | * detected by a background scrubber) | |
2183 | * | |
2184 | * Must run in process context (e.g. a work queue) with interrupts | |
5885c6a6 | 2185 | * enabled and no spinlocks held. |
d1fe111f | 2186 | * |
2187 | * Return: 0 for successfully handled the memory error, | |
9113eaf3 | 2188 | * -EOPNOTSUPP for hwpoison_filter() filtered the error event, |
d1fe111f | 2189 | * < 0(except -EOPNOTSUPP) on failure. |
cd42f4a3 | 2190 | */ |
83b57531 | 2191 | int memory_failure(unsigned long pfn, int flags) |
6a46079c | 2192 | { |
6a46079c | 2193 | struct page *p; |
5dba5c35 | 2194 | struct folio *folio; |
6100e34b | 2195 | struct dev_pagemap *pgmap; |
171936dd | 2196 | int res = 0; |
524fca1e | 2197 | unsigned long page_flags; |
a8b2c2ce | 2198 | bool retry = true; |
405ce051 | 2199 | int hugetlb = 0; |
6a46079c AK |
2200 | |
2201 | if (!sysctl_memory_failure_recovery) | |
83b57531 | 2202 | panic("Memory failure on page %lx", pfn); |
6a46079c | 2203 | |
03b122da TL |
2204 | mutex_lock(&mf_mutex); |
2205 | ||
67f22ba7 | 2206 | if (!(flags & MF_SW_SIMULATED)) |
2207 | hw_memory_failure = true; | |
2208 | ||
96c804a6 DH |
2209 | p = pfn_to_online_page(pfn); |
2210 | if (!p) { | |
03b122da TL |
2211 | res = arch_memory_failure(pfn, flags); |
2212 | if (res == 0) | |
2213 | goto unlock_mutex; | |
2214 | ||
96c804a6 DH |
2215 | if (pfn_valid(pfn)) { |
2216 | pgmap = get_dev_pagemap(pfn, NULL); | |
d51b6846 | 2217 | put_ref_page(pfn, flags); |
03b122da TL |
2218 | if (pgmap) { |
2219 | res = memory_failure_dev_pagemap(pfn, flags, | |
2220 | pgmap); | |
2221 | goto unlock_mutex; | |
2222 | } | |
96c804a6 | 2223 | } |
96f96763 | 2224 | pr_err("%#lx: memory outside kernel control\n", pfn); |
03b122da TL |
2225 | res = -ENXIO; |
2226 | goto unlock_mutex; | |
6a46079c AK |
2227 | } |
2228 | ||
a8b2c2ce | 2229 | try_again: |
405ce051 NH |
2230 | res = try_memory_failure_hugetlb(pfn, flags, &hugetlb); |
2231 | if (hugetlb) | |
171936dd | 2232 | goto unlock_mutex; |
171936dd | 2233 | |
6a46079c | 2234 | if (TestSetPageHWPoison(p)) { |
96f96763 | 2235 | pr_err("%#lx: already hardware poisoned\n", pfn); |
47af12ba | 2236 | res = -EHWPOISON; |
a3f5d80e NH |
2237 | if (flags & MF_ACTION_REQUIRED) |
2238 | res = kill_accessing_process(current, pfn, flags); | |
f361e246 NH |
2239 | if (flags & MF_COUNT_INCREASED) |
2240 | put_page(p); | |
171936dd | 2241 | goto unlock_mutex; |
6a46079c AK |
2242 | } |
2243 | ||
6a46079c AK |
2244 | /* |
2245 | * We need/can do nothing about count=0 pages. | |
2246 | * 1) it's a free page, and therefore in safe hand: | |
9cf28191 | 2247 | * check_new_page() will be the gate keeper. |
761ad8d7 | 2248 | * 2) it's part of a non-compound high order page. |
6a46079c AK |
2249 | * Implies some kernel user: cannot stop them from |
2250 | * R/W the page; let's pray that the page has been | |
2251 | * used and will be freed some time later. | |
2252 | * In fact it's dangerous to directly bump up page count from 0, | |
1c4c3b99 | 2253 | * that may make page_ref_freeze()/page_ref_unfreeze() mismatch. |
6a46079c | 2254 | */ |
0ed950d1 NH |
2255 | if (!(flags & MF_COUNT_INCREASED)) { |
2256 | res = get_hwpoison_page(p, flags); | |
2257 | if (!res) { | |
2258 | if (is_free_buddy_page(p)) { | |
2259 | if (take_page_off_buddy(p)) { | |
2260 | page_ref_inc(p); | |
2261 | res = MF_RECOVERED; | |
2262 | } else { | |
2263 | /* We lost the race, try again */ | |
2264 | if (retry) { | |
2265 | ClearPageHWPoison(p); | |
0ed950d1 NH |
2266 | retry = false; |
2267 | goto try_again; | |
2268 | } | |
2269 | res = MF_FAILED; | |
a8b2c2ce | 2270 | } |
b66d00df | 2271 | res = action_result(pfn, MF_MSG_BUDDY, res); |
0ed950d1 | 2272 | } else { |
b66d00df | 2273 | res = action_result(pfn, MF_MSG_KERNEL_HIGH_ORDER, MF_IGNORED); |
a8b2c2ce | 2274 | } |
0ed950d1 NH |
2275 | goto unlock_mutex; |
2276 | } else if (res < 0) { | |
b66d00df | 2277 | res = action_result(pfn, MF_MSG_UNKNOWN, MF_IGNORED); |
0ed950d1 | 2278 | goto unlock_mutex; |
8d22ba1b | 2279 | } |
6a46079c AK |
2280 | } |
2281 | ||
5dba5c35 MWO |
2282 | folio = page_folio(p); |
2283 | if (folio_test_large(folio)) { | |
eac96c3e YS |
2284 | /* |
2285 | * The flag must be set after the refcount is bumped | |
2286 | * otherwise it may race with THP split. | |
2287 | * And the flag can't be set in get_hwpoison_page() since | |
2288 | * it is called by soft offline too and it is just called | |
5885c6a6 | 2289 | * for !MF_COUNT_INCREASED. So here seems to be the best |
eac96c3e YS |
2290 | * place. |
2291 | * | |
2292 | * Don't need care about the above error handling paths for | |
2293 | * get_hwpoison_page() since they handle either free page | |
2294 | * or unhandlable page. The refcount is bumped iff the | |
2295 | * page is a valid handlable page. | |
2296 | */ | |
5dba5c35 | 2297 | folio_set_has_hwpoisoned(folio); |
2ace36f0 | 2298 | if (try_to_split_thp_page(p) < 0) { |
b66d00df | 2299 | res = action_result(pfn, MF_MSG_UNSPLIT_THP, MF_IGNORED); |
171936dd | 2300 | goto unlock_mutex; |
5d1fd5dc | 2301 | } |
415c64c1 | 2302 | VM_BUG_ON_PAGE(!page_count(p), p); |
5dba5c35 | 2303 | folio = page_folio(p); |
415c64c1 NH |
2304 | } |
2305 | ||
e43c3afb WF |
2306 | /* |
2307 | * We ignore non-LRU pages for good reasons. | |
2308 | * - PG_locked is only well defined for LRU pages and a few others | |
48c935ad | 2309 | * - to avoid races with __SetPageLocked() |
e43c3afb WF |
2310 | * - to avoid races with __SetPageSlab*() (and more non-atomic ops) |
2311 | * The check (unnecessarily) ignores LRU pages being isolated and | |
2312 | * walked by the page reclaim code, however that's not a big loss. | |
2313 | */ | |
5dba5c35 | 2314 | shake_folio(folio); |
e43c3afb | 2315 | |
5dba5c35 | 2316 | folio_lock(folio); |
847ce401 | 2317 | |
f37d4298 | 2318 | /* |
75ee64b3 ML |
2319 | * We're only intended to deal with the non-Compound page here. |
2320 | * However, the page could have changed compound pages due to | |
2321 | * race window. If this happens, we could try again to hopefully | |
2322 | * handle the page next round. | |
f37d4298 | 2323 | */ |
5dba5c35 | 2324 | if (folio_test_large(folio)) { |
75ee64b3 | 2325 | if (retry) { |
e240ac52 | 2326 | ClearPageHWPoison(p); |
5dba5c35 MWO |
2327 | folio_unlock(folio); |
2328 | folio_put(folio); | |
75ee64b3 ML |
2329 | flags &= ~MF_COUNT_INCREASED; |
2330 | retry = false; | |
2331 | goto try_again; | |
2332 | } | |
b66d00df | 2333 | res = action_result(pfn, MF_MSG_DIFFERENT_COMPOUND, MF_IGNORED); |
171936dd | 2334 | goto unlock_page; |
f37d4298 AK |
2335 | } |
2336 | ||
524fca1e NH |
2337 | /* |
2338 | * We use page flags to determine what action should be taken, but | |
2339 | * the flags can be modified by the error containment action. One | |
2340 | * example is an mlocked page, where PG_mlocked is cleared by | |
4d8f7418 DH |
2341 | * folio_remove_rmap_*() in try_to_unmap_one(). So to determine page |
2342 | * status correctly, we save a copy of the page flags at this time. | |
524fca1e | 2343 | */ |
5dba5c35 | 2344 | page_flags = folio->flags; |
524fca1e | 2345 | |
7c116f2b | 2346 | if (hwpoison_filter(p)) { |
2fe62e22 | 2347 | ClearPageHWPoison(p); |
5dba5c35 MWO |
2348 | folio_unlock(folio); |
2349 | folio_put(folio); | |
d1fe111f | 2350 | res = -EOPNOTSUPP; |
171936dd | 2351 | goto unlock_mutex; |
7c116f2b | 2352 | } |
847ce401 | 2353 | |
e8675d29 | 2354 | /* |
5dba5c35 MWO |
2355 | * __munlock_folio() may clear a writeback folio's LRU flag without |
2356 | * the folio lock. We need to wait for writeback completion for this | |
2357 | * folio or it may trigger a vfs BUG while evicting inode. | |
e8675d29 | 2358 | */ |
5dba5c35 | 2359 | if (!folio_test_lru(folio) && !folio_test_writeback(folio)) |
0bc1f8b0 CY |
2360 | goto identify_page_state; |
2361 | ||
6edd6cc6 NH |
2362 | /* |
2363 | * It's very difficult to mess with pages currently under IO | |
2364 | * and in many cases impossible, so we just avoid it here. | |
2365 | */ | |
5dba5c35 | 2366 | folio_wait_writeback(folio); |
6a46079c AK |
2367 | |
2368 | /* | |
2369 | * Now take care of user space mappings. | |
6ffcd825 | 2370 | * Abort on fail: __filemap_remove_folio() assumes unmapped page. |
6a46079c | 2371 | */ |
03468a0f | 2372 | if (!hwpoison_user_mappings(folio, p, pfn, flags)) { |
b66d00df | 2373 | res = action_result(pfn, MF_MSG_UNMAP_FAILED, MF_IGNORED); |
171936dd | 2374 | goto unlock_page; |
1668bfd5 | 2375 | } |
6a46079c AK |
2376 | |
2377 | /* | |
2378 | * Torn down by someone else? | |
2379 | */ | |
5dba5c35 MWO |
2380 | if (folio_test_lru(folio) && !folio_test_swapcache(folio) && |
2381 | folio->mapping == NULL) { | |
b66d00df | 2382 | res = action_result(pfn, MF_MSG_TRUNCATED_LRU, MF_IGNORED); |
171936dd | 2383 | goto unlock_page; |
6a46079c AK |
2384 | } |
2385 | ||
0bc1f8b0 | 2386 | identify_page_state: |
0348d2eb | 2387 | res = identify_page_state(pfn, p, page_flags); |
ea6d0630 NH |
2388 | mutex_unlock(&mf_mutex); |
2389 | return res; | |
171936dd | 2390 | unlock_page: |
5dba5c35 | 2391 | folio_unlock(folio); |
171936dd TL |
2392 | unlock_mutex: |
2393 | mutex_unlock(&mf_mutex); | |
6a46079c AK |
2394 | return res; |
2395 | } | |
cd42f4a3 | 2396 | EXPORT_SYMBOL_GPL(memory_failure); |
847ce401 | 2397 | |
ea8f5fb8 HY |
2398 | #define MEMORY_FAILURE_FIFO_ORDER 4 |
2399 | #define MEMORY_FAILURE_FIFO_SIZE (1 << MEMORY_FAILURE_FIFO_ORDER) | |
2400 | ||
2401 | struct memory_failure_entry { | |
2402 | unsigned long pfn; | |
ea8f5fb8 HY |
2403 | int flags; |
2404 | }; | |
2405 | ||
2406 | struct memory_failure_cpu { | |
2407 | DECLARE_KFIFO(fifo, struct memory_failure_entry, | |
2408 | MEMORY_FAILURE_FIFO_SIZE); | |
2409 | spinlock_t lock; | |
2410 | struct work_struct work; | |
2411 | }; | |
2412 | ||
2413 | static DEFINE_PER_CPU(struct memory_failure_cpu, memory_failure_cpu); | |
2414 | ||
2415 | /** | |
2416 | * memory_failure_queue - Schedule handling memory failure of a page. | |
2417 | * @pfn: Page Number of the corrupted page | |
ea8f5fb8 HY |
2418 | * @flags: Flags for memory failure handling |
2419 | * | |
2420 | * This function is called by the low level hardware error handler | |
2421 | * when it detects hardware memory corruption of a page. It schedules | |
2422 | * the recovering of error page, including dropping pages, killing | |
2423 | * processes etc. | |
2424 | * | |
2425 | * The function is primarily of use for corruptions that | |
2426 | * happen outside the current execution context (e.g. when | |
2427 | * detected by a background scrubber) | |
2428 | * | |
2429 | * Can run in IRQ context. | |
2430 | */ | |
83b57531 | 2431 | void memory_failure_queue(unsigned long pfn, int flags) |
ea8f5fb8 HY |
2432 | { |
2433 | struct memory_failure_cpu *mf_cpu; | |
2434 | unsigned long proc_flags; | |
2435 | struct memory_failure_entry entry = { | |
2436 | .pfn = pfn, | |
ea8f5fb8 HY |
2437 | .flags = flags, |
2438 | }; | |
2439 | ||
2440 | mf_cpu = &get_cpu_var(memory_failure_cpu); | |
2441 | spin_lock_irqsave(&mf_cpu->lock, proc_flags); | |
498d319b | 2442 | if (kfifo_put(&mf_cpu->fifo, entry)) |
ea8f5fb8 HY |
2443 | schedule_work_on(smp_processor_id(), &mf_cpu->work); |
2444 | else | |
96f96763 | 2445 | pr_err("buffer overflow when queuing memory failure at %#lx\n", |
ea8f5fb8 HY |
2446 | pfn); |
2447 | spin_unlock_irqrestore(&mf_cpu->lock, proc_flags); | |
2448 | put_cpu_var(memory_failure_cpu); | |
2449 | } | |
2450 | EXPORT_SYMBOL_GPL(memory_failure_queue); | |
2451 | ||
2452 | static void memory_failure_work_func(struct work_struct *work) | |
2453 | { | |
2454 | struct memory_failure_cpu *mf_cpu; | |
2455 | struct memory_failure_entry entry = { 0, }; | |
2456 | unsigned long proc_flags; | |
2457 | int gotten; | |
2458 | ||
06202231 | 2459 | mf_cpu = container_of(work, struct memory_failure_cpu, work); |
ea8f5fb8 HY |
2460 | for (;;) { |
2461 | spin_lock_irqsave(&mf_cpu->lock, proc_flags); | |
2462 | gotten = kfifo_get(&mf_cpu->fifo, &entry); | |
2463 | spin_unlock_irqrestore(&mf_cpu->lock, proc_flags); | |
2464 | if (!gotten) | |
2465 | break; | |
cf870c70 | 2466 | if (entry.flags & MF_SOFT_OFFLINE) |
feec24a6 | 2467 | soft_offline_page(entry.pfn, entry.flags); |
cf870c70 | 2468 | else |
83b57531 | 2469 | memory_failure(entry.pfn, entry.flags); |
ea8f5fb8 HY |
2470 | } |
2471 | } | |
2472 | ||
06202231 JM |
2473 | /* |
2474 | * Process memory_failure work queued on the specified CPU. | |
2475 | * Used to avoid return-to-userspace racing with the memory_failure workqueue. | |
2476 | */ | |
2477 | void memory_failure_queue_kick(int cpu) | |
2478 | { | |
2479 | struct memory_failure_cpu *mf_cpu; | |
2480 | ||
2481 | mf_cpu = &per_cpu(memory_failure_cpu, cpu); | |
2482 | cancel_work_sync(&mf_cpu->work); | |
2483 | memory_failure_work_func(&mf_cpu->work); | |
2484 | } | |
2485 | ||
ea8f5fb8 HY |
2486 | static int __init memory_failure_init(void) |
2487 | { | |
2488 | struct memory_failure_cpu *mf_cpu; | |
2489 | int cpu; | |
2490 | ||
2491 | for_each_possible_cpu(cpu) { | |
2492 | mf_cpu = &per_cpu(memory_failure_cpu, cpu); | |
2493 | spin_lock_init(&mf_cpu->lock); | |
2494 | INIT_KFIFO(mf_cpu->fifo); | |
2495 | INIT_WORK(&mf_cpu->work, memory_failure_work_func); | |
2496 | } | |
2497 | ||
97de10a9 KW |
2498 | register_sysctl_init("vm", memory_failure_table); |
2499 | ||
ea8f5fb8 HY |
2500 | return 0; |
2501 | } | |
2502 | core_initcall(memory_failure_init); | |
2503 | ||
96f96763 KW |
2504 | #undef pr_fmt |
2505 | #define pr_fmt(fmt) "" fmt | |
a5f65109 NH |
2506 | #define unpoison_pr_info(fmt, pfn, rs) \ |
2507 | ({ \ | |
2508 | if (__ratelimit(rs)) \ | |
2509 | pr_info(fmt, pfn); \ | |
2510 | }) | |
2511 | ||
847ce401 WF |
2512 | /** |
2513 | * unpoison_memory - Unpoison a previously poisoned page | |
2514 | * @pfn: Page number of the to be unpoisoned page | |
2515 | * | |
2516 | * Software-unpoison a page that has been poisoned by | |
2517 | * memory_failure() earlier. | |
2518 | * | |
2519 | * This is only done on the software-level, so it only works | |
2520 | * for linux injected failures, not real hardware failures | |
2521 | * | |
2522 | * Returns 0 for success, otherwise -errno. | |
2523 | */ | |
2524 | int unpoison_memory(unsigned long pfn) | |
2525 | { | |
9637d7df | 2526 | struct folio *folio; |
847ce401 | 2527 | struct page *p; |
f29623e4 | 2528 | int ret = -EBUSY, ghp; |
ac5fcde0 | 2529 | unsigned long count = 1; |
5033091d | 2530 | bool huge = false; |
a5f65109 NH |
2531 | static DEFINE_RATELIMIT_STATE(unpoison_rs, DEFAULT_RATELIMIT_INTERVAL, |
2532 | DEFAULT_RATELIMIT_BURST); | |
847ce401 WF |
2533 | |
2534 | if (!pfn_valid(pfn)) | |
2535 | return -ENXIO; | |
2536 | ||
2537 | p = pfn_to_page(pfn); | |
9637d7df | 2538 | folio = page_folio(p); |
847ce401 | 2539 | |
91d00547 NH |
2540 | mutex_lock(&mf_mutex); |
2541 | ||
67f22ba7 | 2542 | if (hw_memory_failure) { |
2543 | unpoison_pr_info("Unpoison: Disabled after HW memory failure %#lx\n", | |
2544 | pfn, &unpoison_rs); | |
2545 | ret = -EOPNOTSUPP; | |
2546 | goto unlock_mutex; | |
2547 | } | |
2548 | ||
fe6f86f4 ML |
2549 | if (is_huge_zero_folio(folio)) { |
2550 | unpoison_pr_info("Unpoison: huge zero page is not supported %#lx\n", | |
2551 | pfn, &unpoison_rs); | |
2552 | ret = -EOPNOTSUPP; | |
2553 | goto unlock_mutex; | |
2554 | } | |
2555 | ||
6c54312f | 2556 | if (!PageHWPoison(p)) { |
495367c0 | 2557 | unpoison_pr_info("Unpoison: Page was already unpoisoned %#lx\n", |
a5f65109 | 2558 | pfn, &unpoison_rs); |
91d00547 | 2559 | goto unlock_mutex; |
847ce401 WF |
2560 | } |
2561 | ||
a6fddef4 | 2562 | if (folio_ref_count(folio) > 1) { |
495367c0 | 2563 | unpoison_pr_info("Unpoison: Someone grabs the hwpoison page %#lx\n", |
a5f65109 | 2564 | pfn, &unpoison_rs); |
91d00547 | 2565 | goto unlock_mutex; |
230ac719 NH |
2566 | } |
2567 | ||
ee299e98 MWO |
2568 | if (folio_test_slab(folio) || folio_test_pgtable(folio) || |
2569 | folio_test_reserved(folio) || folio_test_offline(folio)) | |
faeb2ff2 ML |
2570 | goto unlock_mutex; |
2571 | ||
2572 | /* | |
2573 | * Note that folio->_mapcount is overloaded in SLAB, so the simple test | |
2574 | * in folio_mapped() has to be done after folio_test_slab() is checked. | |
2575 | */ | |
a6fddef4 | 2576 | if (folio_mapped(folio)) { |
495367c0 | 2577 | unpoison_pr_info("Unpoison: Someone maps the hwpoison page %#lx\n", |
a5f65109 | 2578 | pfn, &unpoison_rs); |
91d00547 | 2579 | goto unlock_mutex; |
230ac719 NH |
2580 | } |
2581 | ||
a6fddef4 | 2582 | if (folio_mapping(folio)) { |
495367c0 | 2583 | unpoison_pr_info("Unpoison: the hwpoison page has non-NULL mapping %#lx\n", |
a5f65109 | 2584 | pfn, &unpoison_rs); |
91d00547 | 2585 | goto unlock_mutex; |
0cea3fdc WL |
2586 | } |
2587 | ||
f29623e4 ML |
2588 | ghp = get_hwpoison_page(p, MF_UNPOISON); |
2589 | if (!ghp) { | |
ee299e98 | 2590 | if (folio_test_hugetlb(folio)) { |
5033091d | 2591 | huge = true; |
9637d7df | 2592 | count = folio_free_raw_hwp(folio, false); |
f29623e4 | 2593 | if (count == 0) |
ac5fcde0 | 2594 | goto unlock_mutex; |
ac5fcde0 | 2595 | } |
a6fddef4 | 2596 | ret = folio_test_clear_hwpoison(folio) ? 0 : -EBUSY; |
f29623e4 ML |
2597 | } else if (ghp < 0) { |
2598 | if (ghp == -EHWPOISON) { | |
c8bd84f7 | 2599 | ret = put_page_back_buddy(p) ? 0 : -EBUSY; |
f29623e4 ML |
2600 | } else { |
2601 | ret = ghp; | |
bf181c58 NH |
2602 | unpoison_pr_info("Unpoison: failed to grab page %#lx\n", |
2603 | pfn, &unpoison_rs); | |
f29623e4 | 2604 | } |
bf181c58 | 2605 | } else { |
ee299e98 | 2606 | if (folio_test_hugetlb(folio)) { |
5033091d | 2607 | huge = true; |
9637d7df | 2608 | count = folio_free_raw_hwp(folio, false); |
ac5fcde0 | 2609 | if (count == 0) { |
a6fddef4 | 2610 | folio_put(folio); |
ac5fcde0 NH |
2611 | goto unlock_mutex; |
2612 | } | |
2613 | } | |
847ce401 | 2614 | |
a6fddef4 | 2615 | folio_put(folio); |
e0ff4280 | 2616 | if (TestClearPageHWPoison(p)) { |
a6fddef4 | 2617 | folio_put(folio); |
bf181c58 NH |
2618 | ret = 0; |
2619 | } | |
2620 | } | |
847ce401 | 2621 | |
91d00547 NH |
2622 | unlock_mutex: |
2623 | mutex_unlock(&mf_mutex); | |
e0ff4280 | 2624 | if (!ret) { |
5033091d NH |
2625 | if (!huge) |
2626 | num_poisoned_pages_sub(pfn, 1); | |
c8bd84f7 | 2627 | unpoison_pr_info("Unpoison: Software-unpoisoned page %#lx\n", |
2628 | page_to_pfn(p), &unpoison_rs); | |
2629 | } | |
91d00547 | 2630 | return ret; |
847ce401 WF |
2631 | } |
2632 | EXPORT_SYMBOL(unpoison_memory); | |
facb6011 | 2633 | |
761d79fb | 2634 | static bool mf_isolate_folio(struct folio *folio, struct list_head *pagelist) |
d950b958 | 2635 | { |
6b9a217e | 2636 | bool isolated = false; |
d950b958 | 2637 | |
761d79fb MWO |
2638 | if (folio_test_hugetlb(folio)) { |
2639 | isolated = isolate_hugetlb(folio, pagelist); | |
6b9a217e | 2640 | } else { |
761d79fb | 2641 | bool lru = !__folio_test_movable(folio); |
da294991 | 2642 | |
6b9a217e | 2643 | if (lru) |
761d79fb | 2644 | isolated = folio_isolate_lru(folio); |
6b9a217e | 2645 | else |
761d79fb | 2646 | isolated = isolate_movable_page(&folio->page, |
cd775580 | 2647 | ISOLATE_UNEVICTABLE); |
6b9a217e | 2648 | |
da294991 | 2649 | if (isolated) { |
761d79fb | 2650 | list_add(&folio->lru, pagelist); |
da294991 | 2651 | if (lru) |
761d79fb MWO |
2652 | node_stat_add_folio(folio, NR_ISOLATED_ANON + |
2653 | folio_is_file_lru(folio)); | |
da294991 | 2654 | } |
0ebff32c | 2655 | } |
d950b958 | 2656 | |
03613808 | 2657 | /* |
761d79fb MWO |
2658 | * If we succeed to isolate the folio, we grabbed another refcount on |
2659 | * the folio, so we can safely drop the one we got from get_any_page(). | |
2660 | * If we failed to isolate the folio, it means that we cannot go further | |
6b9a217e | 2661 | * and we will return an error, so drop the reference we got from |
5885c6a6 | 2662 | * get_any_page() as well. |
03613808 | 2663 | */ |
761d79fb | 2664 | folio_put(folio); |
6b9a217e | 2665 | return isolated; |
d950b958 NH |
2666 | } |
2667 | ||
6b9a217e | 2668 | /* |
48309e1f | 2669 | * soft_offline_in_use_page handles hugetlb-pages and non-hugetlb pages. |
6b9a217e OS |
2670 | * If the page is a non-dirty unmapped page-cache page, it simply invalidates. |
2671 | * If the page is mapped, it migrates the contents over. | |
2672 | */ | |
48309e1f | 2673 | static int soft_offline_in_use_page(struct page *page) |
af8fae7c | 2674 | { |
d6c75dc2 | 2675 | long ret = 0; |
af8fae7c | 2676 | unsigned long pfn = page_to_pfn(page); |
049b2604 | 2677 | struct folio *folio = page_folio(page); |
6b9a217e | 2678 | char const *msg_page[] = {"page", "hugepage"}; |
049b2604 | 2679 | bool huge = folio_test_hugetlb(folio); |
6b9a217e | 2680 | LIST_HEAD(pagelist); |
54608759 JK |
2681 | struct migration_target_control mtc = { |
2682 | .nid = NUMA_NO_NODE, | |
2683 | .gfp_mask = GFP_USER | __GFP_MOVABLE | __GFP_RETRY_MAYFAIL, | |
e42dfe4e | 2684 | .reason = MR_MEMORY_FAILURE, |
54608759 | 2685 | }; |
facb6011 | 2686 | |
049b2604 | 2687 | if (!huge && folio_test_large(folio)) { |
48309e1f KW |
2688 | if (try_to_split_thp_page(page)) { |
2689 | pr_info("soft offline: %#lx: thp split failed\n", pfn); | |
2690 | return -EBUSY; | |
2691 | } | |
049b2604 | 2692 | folio = page_folio(page); |
48309e1f KW |
2693 | } |
2694 | ||
049b2604 | 2695 | folio_lock(folio); |
55c7ac45 | 2696 | if (!huge) |
049b2604 | 2697 | folio_wait_writeback(folio); |
af8fae7c | 2698 | if (PageHWPoison(page)) { |
049b2604 MWO |
2699 | folio_unlock(folio); |
2700 | folio_put(folio); | |
af8fae7c | 2701 | pr_info("soft offline: %#lx page already poisoned\n", pfn); |
5a2ffca3 | 2702 | return 0; |
af8fae7c | 2703 | } |
6b9a217e | 2704 | |
049b2604 | 2705 | if (!huge && folio_test_lru(folio) && !folio_test_swapcache(folio)) |
6b9a217e OS |
2706 | /* |
2707 | * Try to invalidate first. This should work for | |
2708 | * non dirty unmapped page cache pages. | |
2709 | */ | |
049b2604 MWO |
2710 | ret = mapping_evict_folio(folio_mapping(folio), folio); |
2711 | folio_unlock(folio); | |
6b9a217e | 2712 | |
6b9a217e | 2713 | if (ret) { |
fb46e735 | 2714 | pr_info("soft_offline: %#lx: invalidated\n", pfn); |
6b9a217e | 2715 | page_handle_poison(page, false, true); |
af8fae7c | 2716 | return 0; |
facb6011 AK |
2717 | } |
2718 | ||
761d79fb | 2719 | if (mf_isolate_folio(folio, &pagelist)) { |
54608759 | 2720 | ret = migrate_pages(&pagelist, alloc_migration_target, NULL, |
5ac95884 | 2721 | (unsigned long)&mtc, MIGRATE_SYNC, MR_MEMORY_FAILURE, NULL); |
79f5f8fa | 2722 | if (!ret) { |
6b9a217e OS |
2723 | bool release = !huge; |
2724 | ||
2725 | if (!page_handle_poison(page, huge, release)) | |
2726 | ret = -EBUSY; | |
79f5f8fa | 2727 | } else { |
85fbe5d1 YX |
2728 | if (!list_empty(&pagelist)) |
2729 | putback_movable_pages(&pagelist); | |
59c82b70 | 2730 | |
d6c75dc2 | 2731 | pr_info("soft offline: %#lx: %s migration failed %ld, type %pGp\n", |
23efd080 | 2732 | pfn, msg_page[huge], ret, &page->flags); |
facb6011 | 2733 | if (ret > 0) |
3f4b815a | 2734 | ret = -EBUSY; |
facb6011 AK |
2735 | } |
2736 | } else { | |
23efd080 MWO |
2737 | pr_info("soft offline: %#lx: %s isolation failed, page count %d, type %pGp\n", |
2738 | pfn, msg_page[huge], page_count(page), &page->flags); | |
6b9a217e | 2739 | ret = -EBUSY; |
facb6011 | 2740 | } |
facb6011 AK |
2741 | return ret; |
2742 | } | |
86e05773 WL |
2743 | |
2744 | /** | |
2745 | * soft_offline_page - Soft offline a page. | |
feec24a6 | 2746 | * @pfn: pfn to soft-offline |
86e05773 WL |
2747 | * @flags: flags. Same as memory_failure(). |
2748 | * | |
9113eaf3 | 2749 | * Returns 0 on success |
2750 | * -EOPNOTSUPP for hwpoison_filter() filtered the error event | |
2751 | * < 0 otherwise negated errno. | |
86e05773 WL |
2752 | * |
2753 | * Soft offline a page, by migration or invalidation, | |
2754 | * without killing anything. This is for the case when | |
2755 | * a page is not corrupted yet (so it's still valid to access), | |
2756 | * but has had a number of corrected errors and is better taken | |
2757 | * out. | |
2758 | * | |
2759 | * The actual policy on when to do that is maintained by | |
2760 | * user space. | |
2761 | * | |
2762 | * This should never impact any application or cause data loss, | |
2763 | * however it might take some time. | |
2764 | * | |
2765 | * This is not a 100% solution for all memory, but tries to be | |
2766 | * ``good enough'' for the majority of memory. | |
2767 | */ | |
feec24a6 | 2768 | int soft_offline_page(unsigned long pfn, int flags) |
86e05773 WL |
2769 | { |
2770 | int ret; | |
b94e0282 | 2771 | bool try_again = true; |
b5f1fc98 | 2772 | struct page *page; |
dad4e5b3 | 2773 | |
183a7c5d KW |
2774 | if (!pfn_valid(pfn)) { |
2775 | WARN_ON_ONCE(flags & MF_COUNT_INCREASED); | |
feec24a6 | 2776 | return -ENXIO; |
183a7c5d | 2777 | } |
dad4e5b3 | 2778 | |
feec24a6 NH |
2779 | /* Only online pages can be soft-offlined (esp., not ZONE_DEVICE). */ |
2780 | page = pfn_to_online_page(pfn); | |
dad4e5b3 | 2781 | if (!page) { |
b5f1fc98 | 2782 | put_ref_page(pfn, flags); |
86a66810 | 2783 | return -EIO; |
dad4e5b3 | 2784 | } |
86a66810 | 2785 | |
91d00547 NH |
2786 | mutex_lock(&mf_mutex); |
2787 | ||
86e05773 | 2788 | if (PageHWPoison(page)) { |
8295d535 | 2789 | pr_info("%s: %#lx page already poisoned\n", __func__, pfn); |
b5f1fc98 | 2790 | put_ref_page(pfn, flags); |
91d00547 | 2791 | mutex_unlock(&mf_mutex); |
5a2ffca3 | 2792 | return 0; |
86e05773 | 2793 | } |
86e05773 | 2794 | |
b94e0282 | 2795 | retry: |
bfc8c901 | 2796 | get_online_mems(); |
bf6445bc | 2797 | ret = get_hwpoison_page(page, flags | MF_SOFT_OFFLINE); |
bfc8c901 | 2798 | put_online_mems(); |
4e41a30c | 2799 | |
9113eaf3 | 2800 | if (hwpoison_filter(page)) { |
2801 | if (ret > 0) | |
2802 | put_page(page); | |
9113eaf3 | 2803 | |
2804 | mutex_unlock(&mf_mutex); | |
2805 | return -EOPNOTSUPP; | |
2806 | } | |
2807 | ||
8295d535 | 2808 | if (ret > 0) { |
6b9a217e | 2809 | ret = soft_offline_in_use_page(page); |
8295d535 | 2810 | } else if (ret == 0) { |
e2c1ab07 ML |
2811 | if (!page_handle_poison(page, true, false)) { |
2812 | if (try_again) { | |
2813 | try_again = false; | |
2814 | flags &= ~MF_COUNT_INCREASED; | |
2815 | goto retry; | |
2816 | } | |
2817 | ret = -EBUSY; | |
b94e0282 | 2818 | } |
8295d535 | 2819 | } |
4e41a30c | 2820 | |
91d00547 NH |
2821 | mutex_unlock(&mf_mutex); |
2822 | ||
86e05773 WL |
2823 | return ret; |
2824 | } |