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2965faa5 DY |
1 | /* |
2 | * kexec.c - kexec system call core code. | |
3 | * Copyright (C) 2002-2004 Eric Biederman <ebiederm@xmission.com> | |
4 | * | |
5 | * This source code is licensed under the GNU General Public License, | |
6 | * Version 2. See the file COPYING for more details. | |
7 | */ | |
8 | ||
de90a6bc | 9 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
2965faa5 DY |
10 | |
11 | #include <linux/capability.h> | |
12 | #include <linux/mm.h> | |
13 | #include <linux/file.h> | |
14 | #include <linux/slab.h> | |
15 | #include <linux/fs.h> | |
16 | #include <linux/kexec.h> | |
17 | #include <linux/mutex.h> | |
18 | #include <linux/list.h> | |
19 | #include <linux/highmem.h> | |
20 | #include <linux/syscalls.h> | |
21 | #include <linux/reboot.h> | |
22 | #include <linux/ioport.h> | |
23 | #include <linux/hardirq.h> | |
24 | #include <linux/elf.h> | |
25 | #include <linux/elfcore.h> | |
26 | #include <linux/utsname.h> | |
27 | #include <linux/numa.h> | |
28 | #include <linux/suspend.h> | |
29 | #include <linux/device.h> | |
30 | #include <linux/freezer.h> | |
31 | #include <linux/pm.h> | |
32 | #include <linux/cpu.h> | |
33 | #include <linux/uaccess.h> | |
34 | #include <linux/io.h> | |
35 | #include <linux/console.h> | |
36 | #include <linux/vmalloc.h> | |
37 | #include <linux/swap.h> | |
38 | #include <linux/syscore_ops.h> | |
39 | #include <linux/compiler.h> | |
40 | #include <linux/hugetlb.h> | |
41 | ||
42 | #include <asm/page.h> | |
43 | #include <asm/sections.h> | |
44 | ||
45 | #include <crypto/hash.h> | |
46 | #include <crypto/sha.h> | |
47 | #include "kexec_internal.h" | |
48 | ||
49 | DEFINE_MUTEX(kexec_mutex); | |
50 | ||
51 | /* Per cpu memory for storing cpu states in case of system crash. */ | |
52 | note_buf_t __percpu *crash_notes; | |
53 | ||
54 | /* vmcoreinfo stuff */ | |
55 | static unsigned char vmcoreinfo_data[VMCOREINFO_BYTES]; | |
56 | u32 vmcoreinfo_note[VMCOREINFO_NOTE_SIZE/4]; | |
57 | size_t vmcoreinfo_size; | |
58 | size_t vmcoreinfo_max_size = sizeof(vmcoreinfo_data); | |
59 | ||
60 | /* Flag to indicate we are going to kexec a new kernel */ | |
61 | bool kexec_in_progress = false; | |
62 | ||
63 | ||
64 | /* Location of the reserved area for the crash kernel */ | |
65 | struct resource crashk_res = { | |
66 | .name = "Crash kernel", | |
67 | .start = 0, | |
68 | .end = 0, | |
69 | .flags = IORESOURCE_BUSY | IORESOURCE_MEM | |
70 | }; | |
71 | struct resource crashk_low_res = { | |
72 | .name = "Crash kernel", | |
73 | .start = 0, | |
74 | .end = 0, | |
75 | .flags = IORESOURCE_BUSY | IORESOURCE_MEM | |
76 | }; | |
77 | ||
78 | int kexec_should_crash(struct task_struct *p) | |
79 | { | |
80 | /* | |
81 | * If crash_kexec_post_notifiers is enabled, don't run | |
82 | * crash_kexec() here yet, which must be run after panic | |
83 | * notifiers in panic(). | |
84 | */ | |
85 | if (crash_kexec_post_notifiers) | |
86 | return 0; | |
87 | /* | |
88 | * There are 4 panic() calls in do_exit() path, each of which | |
89 | * corresponds to each of these 4 conditions. | |
90 | */ | |
91 | if (in_interrupt() || !p->pid || is_global_init(p) || panic_on_oops) | |
92 | return 1; | |
93 | return 0; | |
94 | } | |
95 | ||
96 | /* | |
97 | * When kexec transitions to the new kernel there is a one-to-one | |
98 | * mapping between physical and virtual addresses. On processors | |
99 | * where you can disable the MMU this is trivial, and easy. For | |
100 | * others it is still a simple predictable page table to setup. | |
101 | * | |
102 | * In that environment kexec copies the new kernel to its final | |
103 | * resting place. This means I can only support memory whose | |
104 | * physical address can fit in an unsigned long. In particular | |
105 | * addresses where (pfn << PAGE_SHIFT) > ULONG_MAX cannot be handled. | |
106 | * If the assembly stub has more restrictive requirements | |
107 | * KEXEC_SOURCE_MEMORY_LIMIT and KEXEC_DEST_MEMORY_LIMIT can be | |
108 | * defined more restrictively in <asm/kexec.h>. | |
109 | * | |
110 | * The code for the transition from the current kernel to the | |
111 | * the new kernel is placed in the control_code_buffer, whose size | |
112 | * is given by KEXEC_CONTROL_PAGE_SIZE. In the best case only a single | |
113 | * page of memory is necessary, but some architectures require more. | |
114 | * Because this memory must be identity mapped in the transition from | |
115 | * virtual to physical addresses it must live in the range | |
116 | * 0 - TASK_SIZE, as only the user space mappings are arbitrarily | |
117 | * modifiable. | |
118 | * | |
119 | * The assembly stub in the control code buffer is passed a linked list | |
120 | * of descriptor pages detailing the source pages of the new kernel, | |
121 | * and the destination addresses of those source pages. As this data | |
122 | * structure is not used in the context of the current OS, it must | |
123 | * be self-contained. | |
124 | * | |
125 | * The code has been made to work with highmem pages and will use a | |
126 | * destination page in its final resting place (if it happens | |
127 | * to allocate it). The end product of this is that most of the | |
128 | * physical address space, and most of RAM can be used. | |
129 | * | |
130 | * Future directions include: | |
131 | * - allocating a page table with the control code buffer identity | |
132 | * mapped, to simplify machine_kexec and make kexec_on_panic more | |
133 | * reliable. | |
134 | */ | |
135 | ||
136 | /* | |
137 | * KIMAGE_NO_DEST is an impossible destination address..., for | |
138 | * allocating pages whose destination address we do not care about. | |
139 | */ | |
140 | #define KIMAGE_NO_DEST (-1UL) | |
141 | ||
142 | static struct page *kimage_alloc_page(struct kimage *image, | |
143 | gfp_t gfp_mask, | |
144 | unsigned long dest); | |
145 | ||
146 | int sanity_check_segment_list(struct kimage *image) | |
147 | { | |
148 | int result, i; | |
149 | unsigned long nr_segments = image->nr_segments; | |
150 | ||
151 | /* | |
152 | * Verify we have good destination addresses. The caller is | |
153 | * responsible for making certain we don't attempt to load | |
154 | * the new image into invalid or reserved areas of RAM. This | |
155 | * just verifies it is an address we can use. | |
156 | * | |
157 | * Since the kernel does everything in page size chunks ensure | |
158 | * the destination addresses are page aligned. Too many | |
159 | * special cases crop of when we don't do this. The most | |
160 | * insidious is getting overlapping destination addresses | |
161 | * simply because addresses are changed to page size | |
162 | * granularity. | |
163 | */ | |
164 | result = -EADDRNOTAVAIL; | |
165 | for (i = 0; i < nr_segments; i++) { | |
166 | unsigned long mstart, mend; | |
167 | ||
168 | mstart = image->segment[i].mem; | |
169 | mend = mstart + image->segment[i].memsz; | |
170 | if ((mstart & ~PAGE_MASK) || (mend & ~PAGE_MASK)) | |
171 | return result; | |
172 | if (mend >= KEXEC_DESTINATION_MEMORY_LIMIT) | |
173 | return result; | |
174 | } | |
175 | ||
176 | /* Verify our destination addresses do not overlap. | |
177 | * If we alloed overlapping destination addresses | |
178 | * through very weird things can happen with no | |
179 | * easy explanation as one segment stops on another. | |
180 | */ | |
181 | result = -EINVAL; | |
182 | for (i = 0; i < nr_segments; i++) { | |
183 | unsigned long mstart, mend; | |
184 | unsigned long j; | |
185 | ||
186 | mstart = image->segment[i].mem; | |
187 | mend = mstart + image->segment[i].memsz; | |
188 | for (j = 0; j < i; j++) { | |
189 | unsigned long pstart, pend; | |
190 | ||
191 | pstart = image->segment[j].mem; | |
192 | pend = pstart + image->segment[j].memsz; | |
193 | /* Do the segments overlap ? */ | |
194 | if ((mend > pstart) && (mstart < pend)) | |
195 | return result; | |
196 | } | |
197 | } | |
198 | ||
199 | /* Ensure our buffer sizes are strictly less than | |
200 | * our memory sizes. This should always be the case, | |
201 | * and it is easier to check up front than to be surprised | |
202 | * later on. | |
203 | */ | |
204 | result = -EINVAL; | |
205 | for (i = 0; i < nr_segments; i++) { | |
206 | if (image->segment[i].bufsz > image->segment[i].memsz) | |
207 | return result; | |
208 | } | |
209 | ||
210 | /* | |
211 | * Verify we have good destination addresses. Normally | |
212 | * the caller is responsible for making certain we don't | |
213 | * attempt to load the new image into invalid or reserved | |
214 | * areas of RAM. But crash kernels are preloaded into a | |
215 | * reserved area of ram. We must ensure the addresses | |
216 | * are in the reserved area otherwise preloading the | |
217 | * kernel could corrupt things. | |
218 | */ | |
219 | ||
220 | if (image->type == KEXEC_TYPE_CRASH) { | |
221 | result = -EADDRNOTAVAIL; | |
222 | for (i = 0; i < nr_segments; i++) { | |
223 | unsigned long mstart, mend; | |
224 | ||
225 | mstart = image->segment[i].mem; | |
226 | mend = mstart + image->segment[i].memsz - 1; | |
227 | /* Ensure we are within the crash kernel limits */ | |
228 | if ((mstart < crashk_res.start) || | |
229 | (mend > crashk_res.end)) | |
230 | return result; | |
231 | } | |
232 | } | |
233 | ||
234 | return 0; | |
235 | } | |
236 | ||
237 | struct kimage *do_kimage_alloc_init(void) | |
238 | { | |
239 | struct kimage *image; | |
240 | ||
241 | /* Allocate a controlling structure */ | |
242 | image = kzalloc(sizeof(*image), GFP_KERNEL); | |
243 | if (!image) | |
244 | return NULL; | |
245 | ||
246 | image->head = 0; | |
247 | image->entry = &image->head; | |
248 | image->last_entry = &image->head; | |
249 | image->control_page = ~0; /* By default this does not apply */ | |
250 | image->type = KEXEC_TYPE_DEFAULT; | |
251 | ||
252 | /* Initialize the list of control pages */ | |
253 | INIT_LIST_HEAD(&image->control_pages); | |
254 | ||
255 | /* Initialize the list of destination pages */ | |
256 | INIT_LIST_HEAD(&image->dest_pages); | |
257 | ||
258 | /* Initialize the list of unusable pages */ | |
259 | INIT_LIST_HEAD(&image->unusable_pages); | |
260 | ||
261 | return image; | |
262 | } | |
263 | ||
264 | int kimage_is_destination_range(struct kimage *image, | |
265 | unsigned long start, | |
266 | unsigned long end) | |
267 | { | |
268 | unsigned long i; | |
269 | ||
270 | for (i = 0; i < image->nr_segments; i++) { | |
271 | unsigned long mstart, mend; | |
272 | ||
273 | mstart = image->segment[i].mem; | |
274 | mend = mstart + image->segment[i].memsz; | |
275 | if ((end > mstart) && (start < mend)) | |
276 | return 1; | |
277 | } | |
278 | ||
279 | return 0; | |
280 | } | |
281 | ||
282 | static struct page *kimage_alloc_pages(gfp_t gfp_mask, unsigned int order) | |
283 | { | |
284 | struct page *pages; | |
285 | ||
286 | pages = alloc_pages(gfp_mask, order); | |
287 | if (pages) { | |
288 | unsigned int count, i; | |
289 | ||
290 | pages->mapping = NULL; | |
291 | set_page_private(pages, order); | |
292 | count = 1 << order; | |
293 | for (i = 0; i < count; i++) | |
294 | SetPageReserved(pages + i); | |
295 | } | |
296 | ||
297 | return pages; | |
298 | } | |
299 | ||
300 | static void kimage_free_pages(struct page *page) | |
301 | { | |
302 | unsigned int order, count, i; | |
303 | ||
304 | order = page_private(page); | |
305 | count = 1 << order; | |
306 | for (i = 0; i < count; i++) | |
307 | ClearPageReserved(page + i); | |
308 | __free_pages(page, order); | |
309 | } | |
310 | ||
311 | void kimage_free_page_list(struct list_head *list) | |
312 | { | |
313 | struct list_head *pos, *next; | |
314 | ||
315 | list_for_each_safe(pos, next, list) { | |
316 | struct page *page; | |
317 | ||
318 | page = list_entry(pos, struct page, lru); | |
319 | list_del(&page->lru); | |
320 | kimage_free_pages(page); | |
321 | } | |
322 | } | |
323 | ||
324 | static struct page *kimage_alloc_normal_control_pages(struct kimage *image, | |
325 | unsigned int order) | |
326 | { | |
327 | /* Control pages are special, they are the intermediaries | |
328 | * that are needed while we copy the rest of the pages | |
329 | * to their final resting place. As such they must | |
330 | * not conflict with either the destination addresses | |
331 | * or memory the kernel is already using. | |
332 | * | |
333 | * The only case where we really need more than one of | |
334 | * these are for architectures where we cannot disable | |
335 | * the MMU and must instead generate an identity mapped | |
336 | * page table for all of the memory. | |
337 | * | |
338 | * At worst this runs in O(N) of the image size. | |
339 | */ | |
340 | struct list_head extra_pages; | |
341 | struct page *pages; | |
342 | unsigned int count; | |
343 | ||
344 | count = 1 << order; | |
345 | INIT_LIST_HEAD(&extra_pages); | |
346 | ||
347 | /* Loop while I can allocate a page and the page allocated | |
348 | * is a destination page. | |
349 | */ | |
350 | do { | |
351 | unsigned long pfn, epfn, addr, eaddr; | |
352 | ||
353 | pages = kimage_alloc_pages(KEXEC_CONTROL_MEMORY_GFP, order); | |
354 | if (!pages) | |
355 | break; | |
356 | pfn = page_to_pfn(pages); | |
357 | epfn = pfn + count; | |
358 | addr = pfn << PAGE_SHIFT; | |
359 | eaddr = epfn << PAGE_SHIFT; | |
360 | if ((epfn >= (KEXEC_CONTROL_MEMORY_LIMIT >> PAGE_SHIFT)) || | |
361 | kimage_is_destination_range(image, addr, eaddr)) { | |
362 | list_add(&pages->lru, &extra_pages); | |
363 | pages = NULL; | |
364 | } | |
365 | } while (!pages); | |
366 | ||
367 | if (pages) { | |
368 | /* Remember the allocated page... */ | |
369 | list_add(&pages->lru, &image->control_pages); | |
370 | ||
371 | /* Because the page is already in it's destination | |
372 | * location we will never allocate another page at | |
373 | * that address. Therefore kimage_alloc_pages | |
374 | * will not return it (again) and we don't need | |
375 | * to give it an entry in image->segment[]. | |
376 | */ | |
377 | } | |
378 | /* Deal with the destination pages I have inadvertently allocated. | |
379 | * | |
380 | * Ideally I would convert multi-page allocations into single | |
381 | * page allocations, and add everything to image->dest_pages. | |
382 | * | |
383 | * For now it is simpler to just free the pages. | |
384 | */ | |
385 | kimage_free_page_list(&extra_pages); | |
386 | ||
387 | return pages; | |
388 | } | |
389 | ||
390 | static struct page *kimage_alloc_crash_control_pages(struct kimage *image, | |
391 | unsigned int order) | |
392 | { | |
393 | /* Control pages are special, they are the intermediaries | |
394 | * that are needed while we copy the rest of the pages | |
395 | * to their final resting place. As such they must | |
396 | * not conflict with either the destination addresses | |
397 | * or memory the kernel is already using. | |
398 | * | |
399 | * Control pages are also the only pags we must allocate | |
400 | * when loading a crash kernel. All of the other pages | |
401 | * are specified by the segments and we just memcpy | |
402 | * into them directly. | |
403 | * | |
404 | * The only case where we really need more than one of | |
405 | * these are for architectures where we cannot disable | |
406 | * the MMU and must instead generate an identity mapped | |
407 | * page table for all of the memory. | |
408 | * | |
409 | * Given the low demand this implements a very simple | |
410 | * allocator that finds the first hole of the appropriate | |
411 | * size in the reserved memory region, and allocates all | |
412 | * of the memory up to and including the hole. | |
413 | */ | |
414 | unsigned long hole_start, hole_end, size; | |
415 | struct page *pages; | |
416 | ||
417 | pages = NULL; | |
418 | size = (1 << order) << PAGE_SHIFT; | |
419 | hole_start = (image->control_page + (size - 1)) & ~(size - 1); | |
420 | hole_end = hole_start + size - 1; | |
421 | while (hole_end <= crashk_res.end) { | |
422 | unsigned long i; | |
423 | ||
424 | if (hole_end > KEXEC_CRASH_CONTROL_MEMORY_LIMIT) | |
425 | break; | |
426 | /* See if I overlap any of the segments */ | |
427 | for (i = 0; i < image->nr_segments; i++) { | |
428 | unsigned long mstart, mend; | |
429 | ||
430 | mstart = image->segment[i].mem; | |
431 | mend = mstart + image->segment[i].memsz - 1; | |
432 | if ((hole_end >= mstart) && (hole_start <= mend)) { | |
433 | /* Advance the hole to the end of the segment */ | |
434 | hole_start = (mend + (size - 1)) & ~(size - 1); | |
435 | hole_end = hole_start + size - 1; | |
436 | break; | |
437 | } | |
438 | } | |
439 | /* If I don't overlap any segments I have found my hole! */ | |
440 | if (i == image->nr_segments) { | |
441 | pages = pfn_to_page(hole_start >> PAGE_SHIFT); | |
04e9949b | 442 | image->control_page = hole_end; |
2965faa5 DY |
443 | break; |
444 | } | |
445 | } | |
2965faa5 DY |
446 | |
447 | return pages; | |
448 | } | |
449 | ||
450 | ||
451 | struct page *kimage_alloc_control_pages(struct kimage *image, | |
452 | unsigned int order) | |
453 | { | |
454 | struct page *pages = NULL; | |
455 | ||
456 | switch (image->type) { | |
457 | case KEXEC_TYPE_DEFAULT: | |
458 | pages = kimage_alloc_normal_control_pages(image, order); | |
459 | break; | |
460 | case KEXEC_TYPE_CRASH: | |
461 | pages = kimage_alloc_crash_control_pages(image, order); | |
462 | break; | |
463 | } | |
464 | ||
465 | return pages; | |
466 | } | |
467 | ||
468 | static int kimage_add_entry(struct kimage *image, kimage_entry_t entry) | |
469 | { | |
470 | if (*image->entry != 0) | |
471 | image->entry++; | |
472 | ||
473 | if (image->entry == image->last_entry) { | |
474 | kimage_entry_t *ind_page; | |
475 | struct page *page; | |
476 | ||
477 | page = kimage_alloc_page(image, GFP_KERNEL, KIMAGE_NO_DEST); | |
478 | if (!page) | |
479 | return -ENOMEM; | |
480 | ||
481 | ind_page = page_address(page); | |
482 | *image->entry = virt_to_phys(ind_page) | IND_INDIRECTION; | |
483 | image->entry = ind_page; | |
484 | image->last_entry = ind_page + | |
485 | ((PAGE_SIZE/sizeof(kimage_entry_t)) - 1); | |
486 | } | |
487 | *image->entry = entry; | |
488 | image->entry++; | |
489 | *image->entry = 0; | |
490 | ||
491 | return 0; | |
492 | } | |
493 | ||
494 | static int kimage_set_destination(struct kimage *image, | |
495 | unsigned long destination) | |
496 | { | |
497 | int result; | |
498 | ||
499 | destination &= PAGE_MASK; | |
500 | result = kimage_add_entry(image, destination | IND_DESTINATION); | |
501 | ||
502 | return result; | |
503 | } | |
504 | ||
505 | ||
506 | static int kimage_add_page(struct kimage *image, unsigned long page) | |
507 | { | |
508 | int result; | |
509 | ||
510 | page &= PAGE_MASK; | |
511 | result = kimage_add_entry(image, page | IND_SOURCE); | |
512 | ||
513 | return result; | |
514 | } | |
515 | ||
516 | ||
517 | static void kimage_free_extra_pages(struct kimage *image) | |
518 | { | |
519 | /* Walk through and free any extra destination pages I may have */ | |
520 | kimage_free_page_list(&image->dest_pages); | |
521 | ||
522 | /* Walk through and free any unusable pages I have cached */ | |
523 | kimage_free_page_list(&image->unusable_pages); | |
524 | ||
525 | } | |
526 | void kimage_terminate(struct kimage *image) | |
527 | { | |
528 | if (*image->entry != 0) | |
529 | image->entry++; | |
530 | ||
531 | *image->entry = IND_DONE; | |
532 | } | |
533 | ||
534 | #define for_each_kimage_entry(image, ptr, entry) \ | |
535 | for (ptr = &image->head; (entry = *ptr) && !(entry & IND_DONE); \ | |
536 | ptr = (entry & IND_INDIRECTION) ? \ | |
537 | phys_to_virt((entry & PAGE_MASK)) : ptr + 1) | |
538 | ||
539 | static void kimage_free_entry(kimage_entry_t entry) | |
540 | { | |
541 | struct page *page; | |
542 | ||
543 | page = pfn_to_page(entry >> PAGE_SHIFT); | |
544 | kimage_free_pages(page); | |
545 | } | |
546 | ||
547 | void kimage_free(struct kimage *image) | |
548 | { | |
549 | kimage_entry_t *ptr, entry; | |
550 | kimage_entry_t ind = 0; | |
551 | ||
552 | if (!image) | |
553 | return; | |
554 | ||
555 | kimage_free_extra_pages(image); | |
556 | for_each_kimage_entry(image, ptr, entry) { | |
557 | if (entry & IND_INDIRECTION) { | |
558 | /* Free the previous indirection page */ | |
559 | if (ind & IND_INDIRECTION) | |
560 | kimage_free_entry(ind); | |
561 | /* Save this indirection page until we are | |
562 | * done with it. | |
563 | */ | |
564 | ind = entry; | |
565 | } else if (entry & IND_SOURCE) | |
566 | kimage_free_entry(entry); | |
567 | } | |
568 | /* Free the final indirection page */ | |
569 | if (ind & IND_INDIRECTION) | |
570 | kimage_free_entry(ind); | |
571 | ||
572 | /* Handle any machine specific cleanup */ | |
573 | machine_kexec_cleanup(image); | |
574 | ||
575 | /* Free the kexec control pages... */ | |
576 | kimage_free_page_list(&image->control_pages); | |
577 | ||
578 | /* | |
579 | * Free up any temporary buffers allocated. This might hit if | |
580 | * error occurred much later after buffer allocation. | |
581 | */ | |
582 | if (image->file_mode) | |
583 | kimage_file_post_load_cleanup(image); | |
584 | ||
585 | kfree(image); | |
586 | } | |
587 | ||
588 | static kimage_entry_t *kimage_dst_used(struct kimage *image, | |
589 | unsigned long page) | |
590 | { | |
591 | kimage_entry_t *ptr, entry; | |
592 | unsigned long destination = 0; | |
593 | ||
594 | for_each_kimage_entry(image, ptr, entry) { | |
595 | if (entry & IND_DESTINATION) | |
596 | destination = entry & PAGE_MASK; | |
597 | else if (entry & IND_SOURCE) { | |
598 | if (page == destination) | |
599 | return ptr; | |
600 | destination += PAGE_SIZE; | |
601 | } | |
602 | } | |
603 | ||
604 | return NULL; | |
605 | } | |
606 | ||
607 | static struct page *kimage_alloc_page(struct kimage *image, | |
608 | gfp_t gfp_mask, | |
609 | unsigned long destination) | |
610 | { | |
611 | /* | |
612 | * Here we implement safeguards to ensure that a source page | |
613 | * is not copied to its destination page before the data on | |
614 | * the destination page is no longer useful. | |
615 | * | |
616 | * To do this we maintain the invariant that a source page is | |
617 | * either its own destination page, or it is not a | |
618 | * destination page at all. | |
619 | * | |
620 | * That is slightly stronger than required, but the proof | |
621 | * that no problems will not occur is trivial, and the | |
622 | * implementation is simply to verify. | |
623 | * | |
624 | * When allocating all pages normally this algorithm will run | |
625 | * in O(N) time, but in the worst case it will run in O(N^2) | |
626 | * time. If the runtime is a problem the data structures can | |
627 | * be fixed. | |
628 | */ | |
629 | struct page *page; | |
630 | unsigned long addr; | |
631 | ||
632 | /* | |
633 | * Walk through the list of destination pages, and see if I | |
634 | * have a match. | |
635 | */ | |
636 | list_for_each_entry(page, &image->dest_pages, lru) { | |
637 | addr = page_to_pfn(page) << PAGE_SHIFT; | |
638 | if (addr == destination) { | |
639 | list_del(&page->lru); | |
640 | return page; | |
641 | } | |
642 | } | |
643 | page = NULL; | |
644 | while (1) { | |
645 | kimage_entry_t *old; | |
646 | ||
647 | /* Allocate a page, if we run out of memory give up */ | |
648 | page = kimage_alloc_pages(gfp_mask, 0); | |
649 | if (!page) | |
650 | return NULL; | |
651 | /* If the page cannot be used file it away */ | |
652 | if (page_to_pfn(page) > | |
653 | (KEXEC_SOURCE_MEMORY_LIMIT >> PAGE_SHIFT)) { | |
654 | list_add(&page->lru, &image->unusable_pages); | |
655 | continue; | |
656 | } | |
657 | addr = page_to_pfn(page) << PAGE_SHIFT; | |
658 | ||
659 | /* If it is the destination page we want use it */ | |
660 | if (addr == destination) | |
661 | break; | |
662 | ||
663 | /* If the page is not a destination page use it */ | |
664 | if (!kimage_is_destination_range(image, addr, | |
665 | addr + PAGE_SIZE)) | |
666 | break; | |
667 | ||
668 | /* | |
669 | * I know that the page is someones destination page. | |
670 | * See if there is already a source page for this | |
671 | * destination page. And if so swap the source pages. | |
672 | */ | |
673 | old = kimage_dst_used(image, addr); | |
674 | if (old) { | |
675 | /* If so move it */ | |
676 | unsigned long old_addr; | |
677 | struct page *old_page; | |
678 | ||
679 | old_addr = *old & PAGE_MASK; | |
680 | old_page = pfn_to_page(old_addr >> PAGE_SHIFT); | |
681 | copy_highpage(page, old_page); | |
682 | *old = addr | (*old & ~PAGE_MASK); | |
683 | ||
684 | /* The old page I have found cannot be a | |
685 | * destination page, so return it if it's | |
686 | * gfp_flags honor the ones passed in. | |
687 | */ | |
688 | if (!(gfp_mask & __GFP_HIGHMEM) && | |
689 | PageHighMem(old_page)) { | |
690 | kimage_free_pages(old_page); | |
691 | continue; | |
692 | } | |
693 | addr = old_addr; | |
694 | page = old_page; | |
695 | break; | |
696 | } | |
697 | /* Place the page on the destination list, to be used later */ | |
698 | list_add(&page->lru, &image->dest_pages); | |
699 | } | |
700 | ||
701 | return page; | |
702 | } | |
703 | ||
704 | static int kimage_load_normal_segment(struct kimage *image, | |
705 | struct kexec_segment *segment) | |
706 | { | |
707 | unsigned long maddr; | |
708 | size_t ubytes, mbytes; | |
709 | int result; | |
710 | unsigned char __user *buf = NULL; | |
711 | unsigned char *kbuf = NULL; | |
712 | ||
713 | result = 0; | |
714 | if (image->file_mode) | |
715 | kbuf = segment->kbuf; | |
716 | else | |
717 | buf = segment->buf; | |
718 | ubytes = segment->bufsz; | |
719 | mbytes = segment->memsz; | |
720 | maddr = segment->mem; | |
721 | ||
722 | result = kimage_set_destination(image, maddr); | |
723 | if (result < 0) | |
724 | goto out; | |
725 | ||
726 | while (mbytes) { | |
727 | struct page *page; | |
728 | char *ptr; | |
729 | size_t uchunk, mchunk; | |
730 | ||
731 | page = kimage_alloc_page(image, GFP_HIGHUSER, maddr); | |
732 | if (!page) { | |
733 | result = -ENOMEM; | |
734 | goto out; | |
735 | } | |
736 | result = kimage_add_page(image, page_to_pfn(page) | |
737 | << PAGE_SHIFT); | |
738 | if (result < 0) | |
739 | goto out; | |
740 | ||
741 | ptr = kmap(page); | |
742 | /* Start with a clear page */ | |
743 | clear_page(ptr); | |
744 | ptr += maddr & ~PAGE_MASK; | |
745 | mchunk = min_t(size_t, mbytes, | |
746 | PAGE_SIZE - (maddr & ~PAGE_MASK)); | |
747 | uchunk = min(ubytes, mchunk); | |
748 | ||
749 | /* For file based kexec, source pages are in kernel memory */ | |
750 | if (image->file_mode) | |
751 | memcpy(ptr, kbuf, uchunk); | |
752 | else | |
753 | result = copy_from_user(ptr, buf, uchunk); | |
754 | kunmap(page); | |
755 | if (result) { | |
756 | result = -EFAULT; | |
757 | goto out; | |
758 | } | |
759 | ubytes -= uchunk; | |
760 | maddr += mchunk; | |
761 | if (image->file_mode) | |
762 | kbuf += mchunk; | |
763 | else | |
764 | buf += mchunk; | |
765 | mbytes -= mchunk; | |
766 | } | |
767 | out: | |
768 | return result; | |
769 | } | |
770 | ||
771 | static int kimage_load_crash_segment(struct kimage *image, | |
772 | struct kexec_segment *segment) | |
773 | { | |
774 | /* For crash dumps kernels we simply copy the data from | |
775 | * user space to it's destination. | |
776 | * We do things a page at a time for the sake of kmap. | |
777 | */ | |
778 | unsigned long maddr; | |
779 | size_t ubytes, mbytes; | |
780 | int result; | |
781 | unsigned char __user *buf = NULL; | |
782 | unsigned char *kbuf = NULL; | |
783 | ||
784 | result = 0; | |
785 | if (image->file_mode) | |
786 | kbuf = segment->kbuf; | |
787 | else | |
788 | buf = segment->buf; | |
789 | ubytes = segment->bufsz; | |
790 | mbytes = segment->memsz; | |
791 | maddr = segment->mem; | |
792 | while (mbytes) { | |
793 | struct page *page; | |
794 | char *ptr; | |
795 | size_t uchunk, mchunk; | |
796 | ||
797 | page = pfn_to_page(maddr >> PAGE_SHIFT); | |
798 | if (!page) { | |
799 | result = -ENOMEM; | |
800 | goto out; | |
801 | } | |
802 | ptr = kmap(page); | |
803 | ptr += maddr & ~PAGE_MASK; | |
804 | mchunk = min_t(size_t, mbytes, | |
805 | PAGE_SIZE - (maddr & ~PAGE_MASK)); | |
806 | uchunk = min(ubytes, mchunk); | |
807 | if (mchunk > uchunk) { | |
808 | /* Zero the trailing part of the page */ | |
809 | memset(ptr + uchunk, 0, mchunk - uchunk); | |
810 | } | |
811 | ||
812 | /* For file based kexec, source pages are in kernel memory */ | |
813 | if (image->file_mode) | |
814 | memcpy(ptr, kbuf, uchunk); | |
815 | else | |
816 | result = copy_from_user(ptr, buf, uchunk); | |
817 | kexec_flush_icache_page(page); | |
818 | kunmap(page); | |
819 | if (result) { | |
820 | result = -EFAULT; | |
821 | goto out; | |
822 | } | |
823 | ubytes -= uchunk; | |
824 | maddr += mchunk; | |
825 | if (image->file_mode) | |
826 | kbuf += mchunk; | |
827 | else | |
828 | buf += mchunk; | |
829 | mbytes -= mchunk; | |
830 | } | |
831 | out: | |
832 | return result; | |
833 | } | |
834 | ||
835 | int kimage_load_segment(struct kimage *image, | |
836 | struct kexec_segment *segment) | |
837 | { | |
838 | int result = -ENOMEM; | |
839 | ||
840 | switch (image->type) { | |
841 | case KEXEC_TYPE_DEFAULT: | |
842 | result = kimage_load_normal_segment(image, segment); | |
843 | break; | |
844 | case KEXEC_TYPE_CRASH: | |
845 | result = kimage_load_crash_segment(image, segment); | |
846 | break; | |
847 | } | |
848 | ||
849 | return result; | |
850 | } | |
851 | ||
852 | struct kimage *kexec_image; | |
853 | struct kimage *kexec_crash_image; | |
854 | int kexec_load_disabled; | |
855 | ||
7bbee5ca HK |
856 | /* |
857 | * No panic_cpu check version of crash_kexec(). This function is called | |
858 | * only when panic_cpu holds the current CPU number; this is the only CPU | |
859 | * which processes crash_kexec routines. | |
860 | */ | |
861 | void __crash_kexec(struct pt_regs *regs) | |
2965faa5 DY |
862 | { |
863 | /* Take the kexec_mutex here to prevent sys_kexec_load | |
864 | * running on one cpu from replacing the crash kernel | |
865 | * we are using after a panic on a different cpu. | |
866 | * | |
867 | * If the crash kernel was not located in a fixed area | |
868 | * of memory the xchg(&kexec_crash_image) would be | |
869 | * sufficient. But since I reuse the memory... | |
870 | */ | |
871 | if (mutex_trylock(&kexec_mutex)) { | |
872 | if (kexec_crash_image) { | |
873 | struct pt_regs fixed_regs; | |
874 | ||
875 | crash_setup_regs(&fixed_regs, regs); | |
876 | crash_save_vmcoreinfo(); | |
877 | machine_crash_shutdown(&fixed_regs); | |
878 | machine_kexec(kexec_crash_image); | |
879 | } | |
880 | mutex_unlock(&kexec_mutex); | |
881 | } | |
882 | } | |
883 | ||
7bbee5ca HK |
884 | void crash_kexec(struct pt_regs *regs) |
885 | { | |
886 | int old_cpu, this_cpu; | |
887 | ||
888 | /* | |
889 | * Only one CPU is allowed to execute the crash_kexec() code as with | |
890 | * panic(). Otherwise parallel calls of panic() and crash_kexec() | |
891 | * may stop each other. To exclude them, we use panic_cpu here too. | |
892 | */ | |
893 | this_cpu = raw_smp_processor_id(); | |
894 | old_cpu = atomic_cmpxchg(&panic_cpu, PANIC_CPU_INVALID, this_cpu); | |
895 | if (old_cpu == PANIC_CPU_INVALID) { | |
896 | /* This is the 1st CPU which comes here, so go ahead. */ | |
897 | __crash_kexec(regs); | |
898 | ||
899 | /* | |
900 | * Reset panic_cpu to allow another panic()/crash_kexec() | |
901 | * call. | |
902 | */ | |
903 | atomic_set(&panic_cpu, PANIC_CPU_INVALID); | |
904 | } | |
905 | } | |
906 | ||
2965faa5 DY |
907 | size_t crash_get_memory_size(void) |
908 | { | |
909 | size_t size = 0; | |
910 | ||
911 | mutex_lock(&kexec_mutex); | |
912 | if (crashk_res.end != crashk_res.start) | |
913 | size = resource_size(&crashk_res); | |
914 | mutex_unlock(&kexec_mutex); | |
915 | return size; | |
916 | } | |
917 | ||
918 | void __weak crash_free_reserved_phys_range(unsigned long begin, | |
919 | unsigned long end) | |
920 | { | |
921 | unsigned long addr; | |
922 | ||
923 | for (addr = begin; addr < end; addr += PAGE_SIZE) | |
924 | free_reserved_page(pfn_to_page(addr >> PAGE_SHIFT)); | |
925 | } | |
926 | ||
927 | int crash_shrink_memory(unsigned long new_size) | |
928 | { | |
929 | int ret = 0; | |
930 | unsigned long start, end; | |
931 | unsigned long old_size; | |
932 | struct resource *ram_res; | |
933 | ||
934 | mutex_lock(&kexec_mutex); | |
935 | ||
936 | if (kexec_crash_image) { | |
937 | ret = -ENOENT; | |
938 | goto unlock; | |
939 | } | |
940 | start = crashk_res.start; | |
941 | end = crashk_res.end; | |
942 | old_size = (end == 0) ? 0 : end - start + 1; | |
943 | if (new_size >= old_size) { | |
944 | ret = (new_size == old_size) ? 0 : -EINVAL; | |
945 | goto unlock; | |
946 | } | |
947 | ||
948 | ram_res = kzalloc(sizeof(*ram_res), GFP_KERNEL); | |
949 | if (!ram_res) { | |
950 | ret = -ENOMEM; | |
951 | goto unlock; | |
952 | } | |
953 | ||
954 | start = roundup(start, KEXEC_CRASH_MEM_ALIGN); | |
955 | end = roundup(start + new_size, KEXEC_CRASH_MEM_ALIGN); | |
956 | ||
957 | crash_map_reserved_pages(); | |
958 | crash_free_reserved_phys_range(end, crashk_res.end); | |
959 | ||
960 | if ((start == end) && (crashk_res.parent != NULL)) | |
961 | release_resource(&crashk_res); | |
962 | ||
963 | ram_res->start = end; | |
964 | ram_res->end = crashk_res.end; | |
965 | ram_res->flags = IORESOURCE_BUSY | IORESOURCE_MEM; | |
966 | ram_res->name = "System RAM"; | |
967 | ||
968 | crashk_res.end = end - 1; | |
969 | ||
970 | insert_resource(&iomem_resource, ram_res); | |
971 | crash_unmap_reserved_pages(); | |
972 | ||
973 | unlock: | |
974 | mutex_unlock(&kexec_mutex); | |
975 | return ret; | |
976 | } | |
977 | ||
978 | static u32 *append_elf_note(u32 *buf, char *name, unsigned type, void *data, | |
979 | size_t data_len) | |
980 | { | |
981 | struct elf_note note; | |
982 | ||
983 | note.n_namesz = strlen(name) + 1; | |
984 | note.n_descsz = data_len; | |
985 | note.n_type = type; | |
986 | memcpy(buf, ¬e, sizeof(note)); | |
987 | buf += (sizeof(note) + 3)/4; | |
988 | memcpy(buf, name, note.n_namesz); | |
989 | buf += (note.n_namesz + 3)/4; | |
990 | memcpy(buf, data, note.n_descsz); | |
991 | buf += (note.n_descsz + 3)/4; | |
992 | ||
993 | return buf; | |
994 | } | |
995 | ||
996 | static void final_note(u32 *buf) | |
997 | { | |
998 | struct elf_note note; | |
999 | ||
1000 | note.n_namesz = 0; | |
1001 | note.n_descsz = 0; | |
1002 | note.n_type = 0; | |
1003 | memcpy(buf, ¬e, sizeof(note)); | |
1004 | } | |
1005 | ||
1006 | void crash_save_cpu(struct pt_regs *regs, int cpu) | |
1007 | { | |
1008 | struct elf_prstatus prstatus; | |
1009 | u32 *buf; | |
1010 | ||
1011 | if ((cpu < 0) || (cpu >= nr_cpu_ids)) | |
1012 | return; | |
1013 | ||
1014 | /* Using ELF notes here is opportunistic. | |
1015 | * I need a well defined structure format | |
1016 | * for the data I pass, and I need tags | |
1017 | * on the data to indicate what information I have | |
1018 | * squirrelled away. ELF notes happen to provide | |
1019 | * all of that, so there is no need to invent something new. | |
1020 | */ | |
1021 | buf = (u32 *)per_cpu_ptr(crash_notes, cpu); | |
1022 | if (!buf) | |
1023 | return; | |
1024 | memset(&prstatus, 0, sizeof(prstatus)); | |
1025 | prstatus.pr_pid = current->pid; | |
1026 | elf_core_copy_kernel_regs(&prstatus.pr_reg, regs); | |
1027 | buf = append_elf_note(buf, KEXEC_CORE_NOTE_NAME, NT_PRSTATUS, | |
1028 | &prstatus, sizeof(prstatus)); | |
1029 | final_note(buf); | |
1030 | } | |
1031 | ||
1032 | static int __init crash_notes_memory_init(void) | |
1033 | { | |
1034 | /* Allocate memory for saving cpu registers. */ | |
bbb78b8f BH |
1035 | size_t size, align; |
1036 | ||
1037 | /* | |
1038 | * crash_notes could be allocated across 2 vmalloc pages when percpu | |
1039 | * is vmalloc based . vmalloc doesn't guarantee 2 continuous vmalloc | |
1040 | * pages are also on 2 continuous physical pages. In this case the | |
1041 | * 2nd part of crash_notes in 2nd page could be lost since only the | |
1042 | * starting address and size of crash_notes are exported through sysfs. | |
1043 | * Here round up the size of crash_notes to the nearest power of two | |
1044 | * and pass it to __alloc_percpu as align value. This can make sure | |
1045 | * crash_notes is allocated inside one physical page. | |
1046 | */ | |
1047 | size = sizeof(note_buf_t); | |
1048 | align = min(roundup_pow_of_two(sizeof(note_buf_t)), PAGE_SIZE); | |
1049 | ||
1050 | /* | |
1051 | * Break compile if size is bigger than PAGE_SIZE since crash_notes | |
1052 | * definitely will be in 2 pages with that. | |
1053 | */ | |
1054 | BUILD_BUG_ON(size > PAGE_SIZE); | |
1055 | ||
1056 | crash_notes = __alloc_percpu(size, align); | |
2965faa5 | 1057 | if (!crash_notes) { |
de90a6bc | 1058 | pr_warn("Memory allocation for saving cpu register states failed\n"); |
2965faa5 DY |
1059 | return -ENOMEM; |
1060 | } | |
1061 | return 0; | |
1062 | } | |
1063 | subsys_initcall(crash_notes_memory_init); | |
1064 | ||
1065 | ||
1066 | /* | |
1067 | * parsing the "crashkernel" commandline | |
1068 | * | |
1069 | * this code is intended to be called from architecture specific code | |
1070 | */ | |
1071 | ||
1072 | ||
1073 | /* | |
1074 | * This function parses command lines in the format | |
1075 | * | |
1076 | * crashkernel=ramsize-range:size[,...][@offset] | |
1077 | * | |
1078 | * The function returns 0 on success and -EINVAL on failure. | |
1079 | */ | |
1080 | static int __init parse_crashkernel_mem(char *cmdline, | |
1081 | unsigned long long system_ram, | |
1082 | unsigned long long *crash_size, | |
1083 | unsigned long long *crash_base) | |
1084 | { | |
1085 | char *cur = cmdline, *tmp; | |
1086 | ||
1087 | /* for each entry of the comma-separated list */ | |
1088 | do { | |
1089 | unsigned long long start, end = ULLONG_MAX, size; | |
1090 | ||
1091 | /* get the start of the range */ | |
1092 | start = memparse(cur, &tmp); | |
1093 | if (cur == tmp) { | |
1094 | pr_warn("crashkernel: Memory value expected\n"); | |
1095 | return -EINVAL; | |
1096 | } | |
1097 | cur = tmp; | |
1098 | if (*cur != '-') { | |
1099 | pr_warn("crashkernel: '-' expected\n"); | |
1100 | return -EINVAL; | |
1101 | } | |
1102 | cur++; | |
1103 | ||
1104 | /* if no ':' is here, than we read the end */ | |
1105 | if (*cur != ':') { | |
1106 | end = memparse(cur, &tmp); | |
1107 | if (cur == tmp) { | |
1108 | pr_warn("crashkernel: Memory value expected\n"); | |
1109 | return -EINVAL; | |
1110 | } | |
1111 | cur = tmp; | |
1112 | if (end <= start) { | |
1113 | pr_warn("crashkernel: end <= start\n"); | |
1114 | return -EINVAL; | |
1115 | } | |
1116 | } | |
1117 | ||
1118 | if (*cur != ':') { | |
1119 | pr_warn("crashkernel: ':' expected\n"); | |
1120 | return -EINVAL; | |
1121 | } | |
1122 | cur++; | |
1123 | ||
1124 | size = memparse(cur, &tmp); | |
1125 | if (cur == tmp) { | |
1126 | pr_warn("Memory value expected\n"); | |
1127 | return -EINVAL; | |
1128 | } | |
1129 | cur = tmp; | |
1130 | if (size >= system_ram) { | |
1131 | pr_warn("crashkernel: invalid size\n"); | |
1132 | return -EINVAL; | |
1133 | } | |
1134 | ||
1135 | /* match ? */ | |
1136 | if (system_ram >= start && system_ram < end) { | |
1137 | *crash_size = size; | |
1138 | break; | |
1139 | } | |
1140 | } while (*cur++ == ','); | |
1141 | ||
1142 | if (*crash_size > 0) { | |
1143 | while (*cur && *cur != ' ' && *cur != '@') | |
1144 | cur++; | |
1145 | if (*cur == '@') { | |
1146 | cur++; | |
1147 | *crash_base = memparse(cur, &tmp); | |
1148 | if (cur == tmp) { | |
1149 | pr_warn("Memory value expected after '@'\n"); | |
1150 | return -EINVAL; | |
1151 | } | |
1152 | } | |
1153 | } | |
1154 | ||
1155 | return 0; | |
1156 | } | |
1157 | ||
1158 | /* | |
1159 | * That function parses "simple" (old) crashkernel command lines like | |
1160 | * | |
1161 | * crashkernel=size[@offset] | |
1162 | * | |
1163 | * It returns 0 on success and -EINVAL on failure. | |
1164 | */ | |
1165 | static int __init parse_crashkernel_simple(char *cmdline, | |
1166 | unsigned long long *crash_size, | |
1167 | unsigned long long *crash_base) | |
1168 | { | |
1169 | char *cur = cmdline; | |
1170 | ||
1171 | *crash_size = memparse(cmdline, &cur); | |
1172 | if (cmdline == cur) { | |
1173 | pr_warn("crashkernel: memory value expected\n"); | |
1174 | return -EINVAL; | |
1175 | } | |
1176 | ||
1177 | if (*cur == '@') | |
1178 | *crash_base = memparse(cur+1, &cur); | |
1179 | else if (*cur != ' ' && *cur != '\0') { | |
53b90c0c | 1180 | pr_warn("crashkernel: unrecognized char: %c\n", *cur); |
2965faa5 DY |
1181 | return -EINVAL; |
1182 | } | |
1183 | ||
1184 | return 0; | |
1185 | } | |
1186 | ||
1187 | #define SUFFIX_HIGH 0 | |
1188 | #define SUFFIX_LOW 1 | |
1189 | #define SUFFIX_NULL 2 | |
1190 | static __initdata char *suffix_tbl[] = { | |
1191 | [SUFFIX_HIGH] = ",high", | |
1192 | [SUFFIX_LOW] = ",low", | |
1193 | [SUFFIX_NULL] = NULL, | |
1194 | }; | |
1195 | ||
1196 | /* | |
1197 | * That function parses "suffix" crashkernel command lines like | |
1198 | * | |
1199 | * crashkernel=size,[high|low] | |
1200 | * | |
1201 | * It returns 0 on success and -EINVAL on failure. | |
1202 | */ | |
1203 | static int __init parse_crashkernel_suffix(char *cmdline, | |
1204 | unsigned long long *crash_size, | |
1205 | const char *suffix) | |
1206 | { | |
1207 | char *cur = cmdline; | |
1208 | ||
1209 | *crash_size = memparse(cmdline, &cur); | |
1210 | if (cmdline == cur) { | |
1211 | pr_warn("crashkernel: memory value expected\n"); | |
1212 | return -EINVAL; | |
1213 | } | |
1214 | ||
1215 | /* check with suffix */ | |
1216 | if (strncmp(cur, suffix, strlen(suffix))) { | |
53b90c0c | 1217 | pr_warn("crashkernel: unrecognized char: %c\n", *cur); |
2965faa5 DY |
1218 | return -EINVAL; |
1219 | } | |
1220 | cur += strlen(suffix); | |
1221 | if (*cur != ' ' && *cur != '\0') { | |
53b90c0c | 1222 | pr_warn("crashkernel: unrecognized char: %c\n", *cur); |
2965faa5 DY |
1223 | return -EINVAL; |
1224 | } | |
1225 | ||
1226 | return 0; | |
1227 | } | |
1228 | ||
1229 | static __init char *get_last_crashkernel(char *cmdline, | |
1230 | const char *name, | |
1231 | const char *suffix) | |
1232 | { | |
1233 | char *p = cmdline, *ck_cmdline = NULL; | |
1234 | ||
1235 | /* find crashkernel and use the last one if there are more */ | |
1236 | p = strstr(p, name); | |
1237 | while (p) { | |
1238 | char *end_p = strchr(p, ' '); | |
1239 | char *q; | |
1240 | ||
1241 | if (!end_p) | |
1242 | end_p = p + strlen(p); | |
1243 | ||
1244 | if (!suffix) { | |
1245 | int i; | |
1246 | ||
1247 | /* skip the one with any known suffix */ | |
1248 | for (i = 0; suffix_tbl[i]; i++) { | |
1249 | q = end_p - strlen(suffix_tbl[i]); | |
1250 | if (!strncmp(q, suffix_tbl[i], | |
1251 | strlen(suffix_tbl[i]))) | |
1252 | goto next; | |
1253 | } | |
1254 | ck_cmdline = p; | |
1255 | } else { | |
1256 | q = end_p - strlen(suffix); | |
1257 | if (!strncmp(q, suffix, strlen(suffix))) | |
1258 | ck_cmdline = p; | |
1259 | } | |
1260 | next: | |
1261 | p = strstr(p+1, name); | |
1262 | } | |
1263 | ||
1264 | if (!ck_cmdline) | |
1265 | return NULL; | |
1266 | ||
1267 | return ck_cmdline; | |
1268 | } | |
1269 | ||
1270 | static int __init __parse_crashkernel(char *cmdline, | |
1271 | unsigned long long system_ram, | |
1272 | unsigned long long *crash_size, | |
1273 | unsigned long long *crash_base, | |
1274 | const char *name, | |
1275 | const char *suffix) | |
1276 | { | |
1277 | char *first_colon, *first_space; | |
1278 | char *ck_cmdline; | |
1279 | ||
1280 | BUG_ON(!crash_size || !crash_base); | |
1281 | *crash_size = 0; | |
1282 | *crash_base = 0; | |
1283 | ||
1284 | ck_cmdline = get_last_crashkernel(cmdline, name, suffix); | |
1285 | ||
1286 | if (!ck_cmdline) | |
1287 | return -EINVAL; | |
1288 | ||
1289 | ck_cmdline += strlen(name); | |
1290 | ||
1291 | if (suffix) | |
1292 | return parse_crashkernel_suffix(ck_cmdline, crash_size, | |
1293 | suffix); | |
1294 | /* | |
1295 | * if the commandline contains a ':', then that's the extended | |
1296 | * syntax -- if not, it must be the classic syntax | |
1297 | */ | |
1298 | first_colon = strchr(ck_cmdline, ':'); | |
1299 | first_space = strchr(ck_cmdline, ' '); | |
1300 | if (first_colon && (!first_space || first_colon < first_space)) | |
1301 | return parse_crashkernel_mem(ck_cmdline, system_ram, | |
1302 | crash_size, crash_base); | |
1303 | ||
1304 | return parse_crashkernel_simple(ck_cmdline, crash_size, crash_base); | |
1305 | } | |
1306 | ||
1307 | /* | |
1308 | * That function is the entry point for command line parsing and should be | |
1309 | * called from the arch-specific code. | |
1310 | */ | |
1311 | int __init parse_crashkernel(char *cmdline, | |
1312 | unsigned long long system_ram, | |
1313 | unsigned long long *crash_size, | |
1314 | unsigned long long *crash_base) | |
1315 | { | |
1316 | return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base, | |
1317 | "crashkernel=", NULL); | |
1318 | } | |
1319 | ||
1320 | int __init parse_crashkernel_high(char *cmdline, | |
1321 | unsigned long long system_ram, | |
1322 | unsigned long long *crash_size, | |
1323 | unsigned long long *crash_base) | |
1324 | { | |
1325 | return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base, | |
1326 | "crashkernel=", suffix_tbl[SUFFIX_HIGH]); | |
1327 | } | |
1328 | ||
1329 | int __init parse_crashkernel_low(char *cmdline, | |
1330 | unsigned long long system_ram, | |
1331 | unsigned long long *crash_size, | |
1332 | unsigned long long *crash_base) | |
1333 | { | |
1334 | return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base, | |
1335 | "crashkernel=", suffix_tbl[SUFFIX_LOW]); | |
1336 | } | |
1337 | ||
1338 | static void update_vmcoreinfo_note(void) | |
1339 | { | |
1340 | u32 *buf = vmcoreinfo_note; | |
1341 | ||
1342 | if (!vmcoreinfo_size) | |
1343 | return; | |
1344 | buf = append_elf_note(buf, VMCOREINFO_NOTE_NAME, 0, vmcoreinfo_data, | |
1345 | vmcoreinfo_size); | |
1346 | final_note(buf); | |
1347 | } | |
1348 | ||
1349 | void crash_save_vmcoreinfo(void) | |
1350 | { | |
1351 | vmcoreinfo_append_str("CRASHTIME=%ld\n", get_seconds()); | |
1352 | update_vmcoreinfo_note(); | |
1353 | } | |
1354 | ||
1355 | void vmcoreinfo_append_str(const char *fmt, ...) | |
1356 | { | |
1357 | va_list args; | |
1358 | char buf[0x50]; | |
1359 | size_t r; | |
1360 | ||
1361 | va_start(args, fmt); | |
1362 | r = vscnprintf(buf, sizeof(buf), fmt, args); | |
1363 | va_end(args); | |
1364 | ||
1365 | r = min(r, vmcoreinfo_max_size - vmcoreinfo_size); | |
1366 | ||
1367 | memcpy(&vmcoreinfo_data[vmcoreinfo_size], buf, r); | |
1368 | ||
1369 | vmcoreinfo_size += r; | |
1370 | } | |
1371 | ||
1372 | /* | |
1373 | * provide an empty default implementation here -- architecture | |
1374 | * code may override this | |
1375 | */ | |
1376 | void __weak arch_crash_save_vmcoreinfo(void) | |
1377 | {} | |
1378 | ||
1379 | unsigned long __weak paddr_vmcoreinfo_note(void) | |
1380 | { | |
1381 | return __pa((unsigned long)(char *)&vmcoreinfo_note); | |
1382 | } | |
1383 | ||
1384 | static int __init crash_save_vmcoreinfo_init(void) | |
1385 | { | |
1386 | VMCOREINFO_OSRELEASE(init_uts_ns.name.release); | |
1387 | VMCOREINFO_PAGESIZE(PAGE_SIZE); | |
1388 | ||
1389 | VMCOREINFO_SYMBOL(init_uts_ns); | |
1390 | VMCOREINFO_SYMBOL(node_online_map); | |
1391 | #ifdef CONFIG_MMU | |
1392 | VMCOREINFO_SYMBOL(swapper_pg_dir); | |
1393 | #endif | |
1394 | VMCOREINFO_SYMBOL(_stext); | |
1395 | VMCOREINFO_SYMBOL(vmap_area_list); | |
1396 | ||
1397 | #ifndef CONFIG_NEED_MULTIPLE_NODES | |
1398 | VMCOREINFO_SYMBOL(mem_map); | |
1399 | VMCOREINFO_SYMBOL(contig_page_data); | |
1400 | #endif | |
1401 | #ifdef CONFIG_SPARSEMEM | |
1402 | VMCOREINFO_SYMBOL(mem_section); | |
1403 | VMCOREINFO_LENGTH(mem_section, NR_SECTION_ROOTS); | |
1404 | VMCOREINFO_STRUCT_SIZE(mem_section); | |
1405 | VMCOREINFO_OFFSET(mem_section, section_mem_map); | |
1406 | #endif | |
1407 | VMCOREINFO_STRUCT_SIZE(page); | |
1408 | VMCOREINFO_STRUCT_SIZE(pglist_data); | |
1409 | VMCOREINFO_STRUCT_SIZE(zone); | |
1410 | VMCOREINFO_STRUCT_SIZE(free_area); | |
1411 | VMCOREINFO_STRUCT_SIZE(list_head); | |
1412 | VMCOREINFO_SIZE(nodemask_t); | |
1413 | VMCOREINFO_OFFSET(page, flags); | |
1414 | VMCOREINFO_OFFSET(page, _count); | |
1415 | VMCOREINFO_OFFSET(page, mapping); | |
1416 | VMCOREINFO_OFFSET(page, lru); | |
1417 | VMCOREINFO_OFFSET(page, _mapcount); | |
1418 | VMCOREINFO_OFFSET(page, private); | |
1419 | VMCOREINFO_OFFSET(pglist_data, node_zones); | |
1420 | VMCOREINFO_OFFSET(pglist_data, nr_zones); | |
1421 | #ifdef CONFIG_FLAT_NODE_MEM_MAP | |
1422 | VMCOREINFO_OFFSET(pglist_data, node_mem_map); | |
1423 | #endif | |
1424 | VMCOREINFO_OFFSET(pglist_data, node_start_pfn); | |
1425 | VMCOREINFO_OFFSET(pglist_data, node_spanned_pages); | |
1426 | VMCOREINFO_OFFSET(pglist_data, node_id); | |
1427 | VMCOREINFO_OFFSET(zone, free_area); | |
1428 | VMCOREINFO_OFFSET(zone, vm_stat); | |
1429 | VMCOREINFO_OFFSET(zone, spanned_pages); | |
1430 | VMCOREINFO_OFFSET(free_area, free_list); | |
1431 | VMCOREINFO_OFFSET(list_head, next); | |
1432 | VMCOREINFO_OFFSET(list_head, prev); | |
1433 | VMCOREINFO_OFFSET(vmap_area, va_start); | |
1434 | VMCOREINFO_OFFSET(vmap_area, list); | |
1435 | VMCOREINFO_LENGTH(zone.free_area, MAX_ORDER); | |
1436 | log_buf_kexec_setup(); | |
1437 | VMCOREINFO_LENGTH(free_area.free_list, MIGRATE_TYPES); | |
1438 | VMCOREINFO_NUMBER(NR_FREE_PAGES); | |
1439 | VMCOREINFO_NUMBER(PG_lru); | |
1440 | VMCOREINFO_NUMBER(PG_private); | |
1441 | VMCOREINFO_NUMBER(PG_swapcache); | |
1442 | VMCOREINFO_NUMBER(PG_slab); | |
1443 | #ifdef CONFIG_MEMORY_FAILURE | |
1444 | VMCOREINFO_NUMBER(PG_hwpoison); | |
1445 | #endif | |
1446 | VMCOREINFO_NUMBER(PG_head_mask); | |
1447 | VMCOREINFO_NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE); | |
1303a27c BH |
1448 | #ifdef CONFIG_X86 |
1449 | VMCOREINFO_NUMBER(KERNEL_IMAGE_SIZE); | |
1450 | #endif | |
2965faa5 DY |
1451 | #ifdef CONFIG_HUGETLBFS |
1452 | VMCOREINFO_SYMBOL(free_huge_page); | |
1453 | #endif | |
1454 | ||
1455 | arch_crash_save_vmcoreinfo(); | |
1456 | update_vmcoreinfo_note(); | |
1457 | ||
1458 | return 0; | |
1459 | } | |
1460 | ||
1461 | subsys_initcall(crash_save_vmcoreinfo_init); | |
1462 | ||
1463 | /* | |
1464 | * Move into place and start executing a preloaded standalone | |
1465 | * executable. If nothing was preloaded return an error. | |
1466 | */ | |
1467 | int kernel_kexec(void) | |
1468 | { | |
1469 | int error = 0; | |
1470 | ||
1471 | if (!mutex_trylock(&kexec_mutex)) | |
1472 | return -EBUSY; | |
1473 | if (!kexec_image) { | |
1474 | error = -EINVAL; | |
1475 | goto Unlock; | |
1476 | } | |
1477 | ||
1478 | #ifdef CONFIG_KEXEC_JUMP | |
1479 | if (kexec_image->preserve_context) { | |
1480 | lock_system_sleep(); | |
1481 | pm_prepare_console(); | |
1482 | error = freeze_processes(); | |
1483 | if (error) { | |
1484 | error = -EBUSY; | |
1485 | goto Restore_console; | |
1486 | } | |
1487 | suspend_console(); | |
1488 | error = dpm_suspend_start(PMSG_FREEZE); | |
1489 | if (error) | |
1490 | goto Resume_console; | |
1491 | /* At this point, dpm_suspend_start() has been called, | |
1492 | * but *not* dpm_suspend_end(). We *must* call | |
1493 | * dpm_suspend_end() now. Otherwise, drivers for | |
1494 | * some devices (e.g. interrupt controllers) become | |
1495 | * desynchronized with the actual state of the | |
1496 | * hardware at resume time, and evil weirdness ensues. | |
1497 | */ | |
1498 | error = dpm_suspend_end(PMSG_FREEZE); | |
1499 | if (error) | |
1500 | goto Resume_devices; | |
1501 | error = disable_nonboot_cpus(); | |
1502 | if (error) | |
1503 | goto Enable_cpus; | |
1504 | local_irq_disable(); | |
1505 | error = syscore_suspend(); | |
1506 | if (error) | |
1507 | goto Enable_irqs; | |
1508 | } else | |
1509 | #endif | |
1510 | { | |
1511 | kexec_in_progress = true; | |
1512 | kernel_restart_prepare(NULL); | |
1513 | migrate_to_reboot_cpu(); | |
1514 | ||
1515 | /* | |
1516 | * migrate_to_reboot_cpu() disables CPU hotplug assuming that | |
1517 | * no further code needs to use CPU hotplug (which is true in | |
1518 | * the reboot case). However, the kexec path depends on using | |
1519 | * CPU hotplug again; so re-enable it here. | |
1520 | */ | |
1521 | cpu_hotplug_enable(); | |
1522 | pr_emerg("Starting new kernel\n"); | |
1523 | machine_shutdown(); | |
1524 | } | |
1525 | ||
1526 | machine_kexec(kexec_image); | |
1527 | ||
1528 | #ifdef CONFIG_KEXEC_JUMP | |
1529 | if (kexec_image->preserve_context) { | |
1530 | syscore_resume(); | |
1531 | Enable_irqs: | |
1532 | local_irq_enable(); | |
1533 | Enable_cpus: | |
1534 | enable_nonboot_cpus(); | |
1535 | dpm_resume_start(PMSG_RESTORE); | |
1536 | Resume_devices: | |
1537 | dpm_resume_end(PMSG_RESTORE); | |
1538 | Resume_console: | |
1539 | resume_console(); | |
1540 | thaw_processes(); | |
1541 | Restore_console: | |
1542 | pm_restore_console(); | |
1543 | unlock_system_sleep(); | |
1544 | } | |
1545 | #endif | |
1546 | ||
1547 | Unlock: | |
1548 | mutex_unlock(&kexec_mutex); | |
1549 | return error; | |
1550 | } | |
1551 | ||
1552 | /* | |
1553 | * Add and remove page tables for crashkernel memory | |
1554 | * | |
1555 | * Provide an empty default implementation here -- architecture | |
1556 | * code may override this | |
1557 | */ | |
1558 | void __weak crash_map_reserved_pages(void) | |
1559 | {} | |
1560 | ||
1561 | void __weak crash_unmap_reserved_pages(void) | |
1562 | {} |