projects/linux·blob v3.13 · refs

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1/*
2 * kexec.c - kexec system call
3 * Copyright (C) 2002-2004 Eric Biederman <[email protected]>
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
9#include <linux/capability.h>
10#include <linux/mm.h>
11#include <linux/file.h>
12#include <linux/slab.h>
13#include <linux/fs.h>
14#include <linux/kexec.h>
15#include <linux/mutex.h>
16#include <linux/list.h>
17#include <linux/highmem.h>
18#include <linux/syscalls.h>
19#include <linux/reboot.h>
20#include <linux/ioport.h>
21#include <linux/hardirq.h>
22#include <linux/elf.h>
23#include <linux/elfcore.h>
24#include <linux/utsname.h>
25#include <linux/numa.h>
26#include <linux/suspend.h>
27#include <linux/device.h>
28#include <linux/freezer.h>
29#include <linux/pm.h>
30#include <linux/cpu.h>
31#include <linux/console.h>
32#include <linux/vmalloc.h>
33#include <linux/swap.h>
34#include <linux/syscore_ops.h>
35
36#include <asm/page.h>
37#include <asm/uaccess.h>
38#include <asm/io.h>
39#include <asm/sections.h>
40
41/* Per cpu memory for storing cpu states in case of system crash. */
42note_buf_t __percpu *crash_notes;
43
44/* vmcoreinfo stuff */
45static unsigned char vmcoreinfo_data[VMCOREINFO_BYTES];
46u32 vmcoreinfo_note[VMCOREINFO_NOTE_SIZE/4];
47size_t vmcoreinfo_size;
48size_t vmcoreinfo_max_size = sizeof(vmcoreinfo_data);
49
50/* Flag to indicate we are going to kexec a new kernel */
51bool kexec_in_progress = false;
52
53/* Location of the reserved area for the crash kernel */
54struct resource crashk_res = {
55 .name = "Crash kernel",
56 .start = 0,
57 .end = 0,
58 .flags = IORESOURCE_BUSY | IORESOURCE_MEM
59};
60struct resource crashk_low_res = {
61 .name = "Crash kernel",
62 .start = 0,
63 .end = 0,
64 .flags = IORESOURCE_BUSY | IORESOURCE_MEM
65};
66
67int kexec_should_crash(struct task_struct *p)
68{
69 if (in_interrupt() || !p->pid || is_global_init(p) || panic_on_oops)
70 return 1;
71 return 0;
72}
73
74/*
75 * When kexec transitions to the new kernel there is a one-to-one
76 * mapping between physical and virtual addresses. On processors
77 * where you can disable the MMU this is trivial, and easy. For
78 * others it is still a simple predictable page table to setup.
79 *
80 * In that environment kexec copies the new kernel to its final
81 * resting place. This means I can only support memory whose
82 * physical address can fit in an unsigned long. In particular
83 * addresses where (pfn << PAGE_SHIFT) > ULONG_MAX cannot be handled.
84 * If the assembly stub has more restrictive requirements
85 * KEXEC_SOURCE_MEMORY_LIMIT and KEXEC_DEST_MEMORY_LIMIT can be
86 * defined more restrictively in <asm/kexec.h>.
87 *
88 * The code for the transition from the current kernel to the
89 * the new kernel is placed in the control_code_buffer, whose size
90 * is given by KEXEC_CONTROL_PAGE_SIZE. In the best case only a single
91 * page of memory is necessary, but some architectures require more.
92 * Because this memory must be identity mapped in the transition from
93 * virtual to physical addresses it must live in the range
94 * 0 - TASK_SIZE, as only the user space mappings are arbitrarily
95 * modifiable.
96 *
97 * The assembly stub in the control code buffer is passed a linked list
98 * of descriptor pages detailing the source pages of the new kernel,
99 * and the destination addresses of those source pages. As this data
100 * structure is not used in the context of the current OS, it must
101 * be self-contained.
102 *
103 * The code has been made to work with highmem pages and will use a
104 * destination page in its final resting place (if it happens
105 * to allocate it). The end product of this is that most of the
106 * physical address space, and most of RAM can be used.
107 *
108 * Future directions include:
109 * - allocating a page table with the control code buffer identity
110 * mapped, to simplify machine_kexec and make kexec_on_panic more
111 * reliable.
112 */
113
114/*
115 * KIMAGE_NO_DEST is an impossible destination address..., for
116 * allocating pages whose destination address we do not care about.
117 */
118#define KIMAGE_NO_DEST (-1UL)
119
120static int kimage_is_destination_range(struct kimage *image,
121 unsigned long start, unsigned long end);
122static struct page *kimage_alloc_page(struct kimage *image,
123 gfp_t gfp_mask,
124 unsigned long dest);
125
126static int do_kimage_alloc(struct kimage **rimage, unsigned long entry,
127 unsigned long nr_segments,
128 struct kexec_segment __user *segments)
129{
130 size_t segment_bytes;
131 struct kimage *image;
132 unsigned long i;
133 int result;
134
135 /* Allocate a controlling structure */
136 result = -ENOMEM;
137 image = kzalloc(sizeof(*image), GFP_KERNEL);
138 if (!image)
139 goto out;
140
141 image->head = 0;
142 image->entry = &image->head;
143 image->last_entry = &image->head;
144 image->control_page = ~0; /* By default this does not apply */
145 image->start = entry;
146 image->type = KEXEC_TYPE_DEFAULT;
147
148 /* Initialize the list of control pages */
149 INIT_LIST_HEAD(&image->control_pages);
150
151 /* Initialize the list of destination pages */
152 INIT_LIST_HEAD(&image->dest_pages);
153
154 /* Initialize the list of unusable pages */
155 INIT_LIST_HEAD(&image->unuseable_pages);
156
157 /* Read in the segments */
158 image->nr_segments = nr_segments;
159 segment_bytes = nr_segments * sizeof(*segments);
160 result = copy_from_user(image->segment, segments, segment_bytes);
161 if (result) {
162 result = -EFAULT;
163 goto out;
164 }
165
166 /*
167 * Verify we have good destination addresses. The caller is
168 * responsible for making certain we don't attempt to load
169 * the new image into invalid or reserved areas of RAM. This
170 * just verifies it is an address we can use.
171 *
172 * Since the kernel does everything in page size chunks ensure
173 * the destination addresses are page aligned. Too many
174 * special cases crop of when we don't do this. The most
175 * insidious is getting overlapping destination addresses
176 * simply because addresses are changed to page size
177 * granularity.
178 */
179 result = -EADDRNOTAVAIL;
180 for (i = 0; i < nr_segments; i++) {
181 unsigned long mstart, mend;
182
183 mstart = image->segment[i].mem;
184 mend = mstart + image->segment[i].memsz;
185 if ((mstart & ~PAGE_MASK) || (mend & ~PAGE_MASK))
186 goto out;
187 if (mend >= KEXEC_DESTINATION_MEMORY_LIMIT)
188 goto out;
189 }
190
191 /* Verify our destination addresses do not overlap.
192 * If we alloed overlapping destination addresses
193 * through very weird things can happen with no
194 * easy explanation as one segment stops on another.
195 */
196 result = -EINVAL;
197 for (i = 0; i < nr_segments; i++) {
198 unsigned long mstart, mend;
199 unsigned long j;
200
201 mstart = image->segment[i].mem;
202 mend = mstart + image->segment[i].memsz;
203 for (j = 0; j < i; j++) {
204 unsigned long pstart, pend;
205 pstart = image->segment[j].mem;
206 pend = pstart + image->segment[j].memsz;
207 /* Do the segments overlap ? */
208 if ((mend > pstart) && (mstart < pend))
209 goto out;
210 }
211 }
212
213 /* Ensure our buffer sizes are strictly less than
214 * our memory sizes. This should always be the case,
215 * and it is easier to check up front than to be surprised
216 * later on.
217 */
218 result = -EINVAL;
219 for (i = 0; i < nr_segments; i++) {
220 if (image->segment[i].bufsz > image->segment[i].memsz)
221 goto out;
222 }
223
224 result = 0;
225out:
226 if (result == 0)
227 *rimage = image;
228 else
229 kfree(image);
230
231 return result;
232
233}
234
235static void kimage_free_page_list(struct list_head *list);
236
237static int kimage_normal_alloc(struct kimage **rimage, unsigned long entry,
238 unsigned long nr_segments,
239 struct kexec_segment __user *segments)
240{
241 int result;
242 struct kimage *image;
243
244 /* Allocate and initialize a controlling structure */
245 image = NULL;
246 result = do_kimage_alloc(&image, entry, nr_segments, segments);
247 if (result)
248 goto out;
249
250 /*
251 * Find a location for the control code buffer, and add it
252 * the vector of segments so that it's pages will also be
253 * counted as destination pages.
254 */
255 result = -ENOMEM;
256 image->control_code_page = kimage_alloc_control_pages(image,
257 get_order(KEXEC_CONTROL_PAGE_SIZE));
258 if (!image->control_code_page) {
259 printk(KERN_ERR "Could not allocate control_code_buffer\n");
260 goto out_free;
261 }
262
263 image->swap_page = kimage_alloc_control_pages(image, 0);
264 if (!image->swap_page) {
265 printk(KERN_ERR "Could not allocate swap buffer\n");
266 goto out_free;
267 }
268
269 *rimage = image;
270 return 0;
271
272out_free:
273 kimage_free_page_list(&image->control_pages);
274 kfree(image);
275out:
276 return result;
277}
278
279static int kimage_crash_alloc(struct kimage **rimage, unsigned long entry,
280 unsigned long nr_segments,
281 struct kexec_segment __user *segments)
282{
283 int result;
284 struct kimage *image;
285 unsigned long i;
286
287 image = NULL;
288 /* Verify we have a valid entry point */
289 if ((entry < crashk_res.start) || (entry > crashk_res.end)) {
290 result = -EADDRNOTAVAIL;
291 goto out;
292 }
293
294 /* Allocate and initialize a controlling structure */
295 result = do_kimage_alloc(&image, entry, nr_segments, segments);
296 if (result)
297 goto out;
298
299 /* Enable the special crash kernel control page
300 * allocation policy.
301 */
302 image->control_page = crashk_res.start;
303 image->type = KEXEC_TYPE_CRASH;
304
305 /*
306 * Verify we have good destination addresses. Normally
307 * the caller is responsible for making certain we don't
308 * attempt to load the new image into invalid or reserved
309 * areas of RAM. But crash kernels are preloaded into a
310 * reserved area of ram. We must ensure the addresses
311 * are in the reserved area otherwise preloading the
312 * kernel could corrupt things.
313 */
314 result = -EADDRNOTAVAIL;
315 for (i = 0; i < nr_segments; i++) {
316 unsigned long mstart, mend;
317
318 mstart = image->segment[i].mem;
319 mend = mstart + image->segment[i].memsz - 1;
320 /* Ensure we are within the crash kernel limits */
321 if ((mstart < crashk_res.start) || (mend > crashk_res.end))
322 goto out_free;
323 }
324
325 /*
326 * Find a location for the control code buffer, and add
327 * the vector of segments so that it's pages will also be
328 * counted as destination pages.
329 */
330 result = -ENOMEM;
331 image->control_code_page = kimage_alloc_control_pages(image,
332 get_order(KEXEC_CONTROL_PAGE_SIZE));
333 if (!image->control_code_page) {
334 printk(KERN_ERR "Could not allocate control_code_buffer\n");
335 goto out_free;
336 }
337
338 *rimage = image;
339 return 0;
340
341out_free:
342 kfree(image);
343out:
344 return result;
345}
346
347static int kimage_is_destination_range(struct kimage *image,
348 unsigned long start,
349 unsigned long end)
350{
351 unsigned long i;
352
353 for (i = 0; i < image->nr_segments; i++) {
354 unsigned long mstart, mend;
355
356 mstart = image->segment[i].mem;
357 mend = mstart + image->segment[i].memsz;
358 if ((end > mstart) && (start < mend))
359 return 1;
360 }
361
362 return 0;
363}
364
365static struct page *kimage_alloc_pages(gfp_t gfp_mask, unsigned int order)
366{
367 struct page *pages;
368
369 pages = alloc_pages(gfp_mask, order);
370 if (pages) {
371 unsigned int count, i;
372 pages->mapping = NULL;
373 set_page_private(pages, order);
374 count = 1 << order;
375 for (i = 0; i < count; i++)
376 SetPageReserved(pages + i);
377 }
378
379 return pages;
380}
381
382static void kimage_free_pages(struct page *page)
383{
384 unsigned int order, count, i;
385
386 order = page_private(page);
387 count = 1 << order;
388 for (i = 0; i < count; i++)
389 ClearPageReserved(page + i);
390 __free_pages(page, order);
391}
392
393static void kimage_free_page_list(struct list_head *list)
394{
395 struct list_head *pos, *next;
396
397 list_for_each_safe(pos, next, list) {
398 struct page *page;
399
400 page = list_entry(pos, struct page, lru);
401 list_del(&page->lru);
402 kimage_free_pages(page);
403 }
404}
405
406static struct page *kimage_alloc_normal_control_pages(struct kimage *image,
407 unsigned int order)
408{
409 /* Control pages are special, they are the intermediaries
410 * that are needed while we copy the rest of the pages
411 * to their final resting place. As such they must
412 * not conflict with either the destination addresses
413 * or memory the kernel is already using.
414 *
415 * The only case where we really need more than one of
416 * these are for architectures where we cannot disable
417 * the MMU and must instead generate an identity mapped
418 * page table for all of the memory.
419 *
420 * At worst this runs in O(N) of the image size.
421 */
422 struct list_head extra_pages;
423 struct page *pages;
424 unsigned int count;
425
426 count = 1 << order;
427 INIT_LIST_HEAD(&extra_pages);
428
429 /* Loop while I can allocate a page and the page allocated
430 * is a destination page.
431 */
432 do {
433 unsigned long pfn, epfn, addr, eaddr;
434
435 pages = kimage_alloc_pages(GFP_KERNEL, order);
436 if (!pages)
437 break;
438 pfn = page_to_pfn(pages);
439 epfn = pfn + count;
440 addr = pfn << PAGE_SHIFT;
441 eaddr = epfn << PAGE_SHIFT;
442 if ((epfn >= (KEXEC_CONTROL_MEMORY_LIMIT >> PAGE_SHIFT)) ||
443 kimage_is_destination_range(image, addr, eaddr)) {
444 list_add(&pages->lru, &extra_pages);
445 pages = NULL;
446 }
447 } while (!pages);
448
449 if (pages) {
450 /* Remember the allocated page... */
451 list_add(&pages->lru, &image->control_pages);
452
453 /* Because the page is already in it's destination
454 * location we will never allocate another page at
455 * that address. Therefore kimage_alloc_pages
456 * will not return it (again) and we don't need
457 * to give it an entry in image->segment[].
458 */
459 }
460 /* Deal with the destination pages I have inadvertently allocated.
461 *
462 * Ideally I would convert multi-page allocations into single
463 * page allocations, and add everything to image->dest_pages.
464 *
465 * For now it is simpler to just free the pages.
466 */
467 kimage_free_page_list(&extra_pages);
468
469 return pages;
470}
471
472static struct page *kimage_alloc_crash_control_pages(struct kimage *image,
473 unsigned int order)
474{
475 /* Control pages are special, they are the intermediaries
476 * that are needed while we copy the rest of the pages
477 * to their final resting place. As such they must
478 * not conflict with either the destination addresses
479 * or memory the kernel is already using.
480 *
481 * Control pages are also the only pags we must allocate
482 * when loading a crash kernel. All of the other pages
483 * are specified by the segments and we just memcpy
484 * into them directly.
485 *
486 * The only case where we really need more than one of
487 * these are for architectures where we cannot disable
488 * the MMU and must instead generate an identity mapped
489 * page table for all of the memory.
490 *
491 * Given the low demand this implements a very simple
492 * allocator that finds the first hole of the appropriate
493 * size in the reserved memory region, and allocates all
494 * of the memory up to and including the hole.
495 */
496 unsigned long hole_start, hole_end, size;
497 struct page *pages;
498
499 pages = NULL;
500 size = (1 << order) << PAGE_SHIFT;
501 hole_start = (image->control_page + (size - 1)) & ~(size - 1);
502 hole_end = hole_start + size - 1;
503 while (hole_end <= crashk_res.end) {
504 unsigned long i;
505
506 if (hole_end > KEXEC_CRASH_CONTROL_MEMORY_LIMIT)
507 break;
508 /* See if I overlap any of the segments */
509 for (i = 0; i < image->nr_segments; i++) {
510 unsigned long mstart, mend;
511
512 mstart = image->segment[i].mem;
513 mend = mstart + image->segment[i].memsz - 1;
514 if ((hole_end >= mstart) && (hole_start <= mend)) {
515 /* Advance the hole to the end of the segment */
516 hole_start = (mend + (size - 1)) & ~(size - 1);
517 hole_end = hole_start + size - 1;
518 break;
519 }
520 }
521 /* If I don't overlap any segments I have found my hole! */
522 if (i == image->nr_segments) {
523 pages = pfn_to_page(hole_start >> PAGE_SHIFT);
524 break;
525 }
526 }
527 if (pages)
528 image->control_page = hole_end;
529
530 return pages;
531}
532
533
534struct page *kimage_alloc_control_pages(struct kimage *image,
535 unsigned int order)
536{
537 struct page *pages = NULL;
538
539 switch (image->type) {
540 case KEXEC_TYPE_DEFAULT:
541 pages = kimage_alloc_normal_control_pages(image, order);
542 break;
543 case KEXEC_TYPE_CRASH:
544 pages = kimage_alloc_crash_control_pages(image, order);
545 break;
546 }
547
548 return pages;
549}
550
551static int kimage_add_entry(struct kimage *image, kimage_entry_t entry)
552{
553 if (*image->entry != 0)
554 image->entry++;
555
556 if (image->entry == image->last_entry) {
557 kimage_entry_t *ind_page;
558 struct page *page;
559
560 page = kimage_alloc_page(image, GFP_KERNEL, KIMAGE_NO_DEST);
561 if (!page)
562 return -ENOMEM;
563
564 ind_page = page_address(page);
565 *image->entry = virt_to_phys(ind_page) | IND_INDIRECTION;
566 image->entry = ind_page;
567 image->last_entry = ind_page +
568 ((PAGE_SIZE/sizeof(kimage_entry_t)) - 1);
569 }
570 *image->entry = entry;
571 image->entry++;
572 *image->entry = 0;
573
574 return 0;
575}
576
577static int kimage_set_destination(struct kimage *image,
578 unsigned long destination)
579{
580 int result;
581
582 destination &= PAGE_MASK;
583 result = kimage_add_entry(image, destination | IND_DESTINATION);
584 if (result == 0)
585 image->destination = destination;
586
587 return result;
588}
589
590
591static int kimage_add_page(struct kimage *image, unsigned long page)
592{
593 int result;
594
595 page &= PAGE_MASK;
596 result = kimage_add_entry(image, page | IND_SOURCE);
597 if (result == 0)
598 image->destination += PAGE_SIZE;
599
600 return result;
601}
602
603
604static void kimage_free_extra_pages(struct kimage *image)
605{
606 /* Walk through and free any extra destination pages I may have */
607 kimage_free_page_list(&image->dest_pages);
608
609 /* Walk through and free any unusable pages I have cached */
610 kimage_free_page_list(&image->unuseable_pages);
611
612}
613static void kimage_terminate(struct kimage *image)
614{
615 if (*image->entry != 0)
616 image->entry++;
617
618 *image->entry = IND_DONE;
619}
620
621#define for_each_kimage_entry(image, ptr, entry) \
622 for (ptr = &image->head; (entry = *ptr) && !(entry & IND_DONE); \
623 ptr = (entry & IND_INDIRECTION)? \
624 phys_to_virt((entry & PAGE_MASK)): ptr +1)
625
626static void kimage_free_entry(kimage_entry_t entry)
627{
628 struct page *page;
629
630 page = pfn_to_page(entry >> PAGE_SHIFT);
631 kimage_free_pages(page);
632}
633
634static void kimage_free(struct kimage *image)
635{
636 kimage_entry_t *ptr, entry;
637 kimage_entry_t ind = 0;
638
639 if (!image)
640 return;
641
642 kimage_free_extra_pages(image);
643 for_each_kimage_entry(image, ptr, entry) {
644 if (entry & IND_INDIRECTION) {
645 /* Free the previous indirection page */
646 if (ind & IND_INDIRECTION)
647 kimage_free_entry(ind);
648 /* Save this indirection page until we are
649 * done with it.
650 */
651 ind = entry;
652 }
653 else if (entry & IND_SOURCE)
654 kimage_free_entry(entry);
655 }
656 /* Free the final indirection page */
657 if (ind & IND_INDIRECTION)
658 kimage_free_entry(ind);
659
660 /* Handle any machine specific cleanup */
661 machine_kexec_cleanup(image);
662
663 /* Free the kexec control pages... */
664 kimage_free_page_list(&image->control_pages);
665 kfree(image);
666}
667
668static kimage_entry_t *kimage_dst_used(struct kimage *image,
669 unsigned long page)
670{
671 kimage_entry_t *ptr, entry;
672 unsigned long destination = 0;
673
674 for_each_kimage_entry(image, ptr, entry) {
675 if (entry & IND_DESTINATION)
676 destination = entry & PAGE_MASK;
677 else if (entry & IND_SOURCE) {
678 if (page == destination)
679 return ptr;
680 destination += PAGE_SIZE;
681 }
682 }
683
684 return NULL;
685}
686
687static struct page *kimage_alloc_page(struct kimage *image,
688 gfp_t gfp_mask,
689 unsigned long destination)
690{
691 /*
692 * Here we implement safeguards to ensure that a source page
693 * is not copied to its destination page before the data on
694 * the destination page is no longer useful.
695 *
696 * To do this we maintain the invariant that a source page is
697 * either its own destination page, or it is not a
698 * destination page at all.
699 *
700 * That is slightly stronger than required, but the proof
701 * that no problems will not occur is trivial, and the
702 * implementation is simply to verify.
703 *
704 * When allocating all pages normally this algorithm will run
705 * in O(N) time, but in the worst case it will run in O(N^2)
706 * time. If the runtime is a problem the data structures can
707 * be fixed.
708 */
709 struct page *page;
710 unsigned long addr;
711
712 /*
713 * Walk through the list of destination pages, and see if I
714 * have a match.
715 */
716 list_for_each_entry(page, &image->dest_pages, lru) {
717 addr = page_to_pfn(page) << PAGE_SHIFT;
718 if (addr == destination) {
719 list_del(&page->lru);
720 return page;
721 }
722 }
723 page = NULL;
724 while (1) {
725 kimage_entry_t *old;
726
727 /* Allocate a page, if we run out of memory give up */
728 page = kimage_alloc_pages(gfp_mask, 0);
729 if (!page)
730 return NULL;
731 /* If the page cannot be used file it away */
732 if (page_to_pfn(page) >
733 (KEXEC_SOURCE_MEMORY_LIMIT >> PAGE_SHIFT)) {
734 list_add(&page->lru, &image->unuseable_pages);
735 continue;
736 }
737 addr = page_to_pfn(page) << PAGE_SHIFT;
738
739 /* If it is the destination page we want use it */
740 if (addr == destination)
741 break;
742
743 /* If the page is not a destination page use it */
744 if (!kimage_is_destination_range(image, addr,
745 addr + PAGE_SIZE))
746 break;
747
748 /*
749 * I know that the page is someones destination page.
750 * See if there is already a source page for this
751 * destination page. And if so swap the source pages.
752 */
753 old = kimage_dst_used(image, addr);
754 if (old) {
755 /* If so move it */
756 unsigned long old_addr;
757 struct page *old_page;
758
759 old_addr = *old & PAGE_MASK;
760 old_page = pfn_to_page(old_addr >> PAGE_SHIFT);
761 copy_highpage(page, old_page);
762 *old = addr | (*old & ~PAGE_MASK);
763
764 /* The old page I have found cannot be a
765 * destination page, so return it if it's
766 * gfp_flags honor the ones passed in.
767 */
768 if (!(gfp_mask & __GFP_HIGHMEM) &&
769 PageHighMem(old_page)) {
770 kimage_free_pages(old_page);
771 continue;
772 }
773 addr = old_addr;
774 page = old_page;
775 break;
776 }
777 else {
778 /* Place the page on the destination list I
779 * will use it later.
780 */
781 list_add(&page->lru, &image->dest_pages);
782 }
783 }
784
785 return page;
786}
787
788static int kimage_load_normal_segment(struct kimage *image,
789 struct kexec_segment *segment)
790{
791 unsigned long maddr;
792 size_t ubytes, mbytes;
793 int result;
794 unsigned char __user *buf;
795
796 result = 0;
797 buf = segment->buf;
798 ubytes = segment->bufsz;
799 mbytes = segment->memsz;
800 maddr = segment->mem;
801
802 result = kimage_set_destination(image, maddr);
803 if (result < 0)
804 goto out;
805
806 while (mbytes) {
807 struct page *page;
808 char *ptr;
809 size_t uchunk, mchunk;
810
811 page = kimage_alloc_page(image, GFP_HIGHUSER, maddr);
812 if (!page) {
813 result = -ENOMEM;
814 goto out;
815 }
816 result = kimage_add_page(image, page_to_pfn(page)
817 << PAGE_SHIFT);
818 if (result < 0)
819 goto out;
820
821 ptr = kmap(page);
822 /* Start with a clear page */
823 clear_page(ptr);
824 ptr += maddr & ~PAGE_MASK;
825 mchunk = min_t(size_t, mbytes,
826 PAGE_SIZE - (maddr & ~PAGE_MASK));
827 uchunk = min(ubytes, mchunk);
828
829 result = copy_from_user(ptr, buf, uchunk);
830 kunmap(page);
831 if (result) {
832 result = -EFAULT;
833 goto out;
834 }
835 ubytes -= uchunk;
836 maddr += mchunk;
837 buf += mchunk;
838 mbytes -= mchunk;
839 }
840out:
841 return result;
842}
843
844static int kimage_load_crash_segment(struct kimage *image,
845 struct kexec_segment *segment)
846{
847 /* For crash dumps kernels we simply copy the data from
848 * user space to it's destination.
849 * We do things a page at a time for the sake of kmap.
850 */
851 unsigned long maddr;
852 size_t ubytes, mbytes;
853 int result;
854 unsigned char __user *buf;
855
856 result = 0;
857 buf = segment->buf;
858 ubytes = segment->bufsz;
859 mbytes = segment->memsz;
860 maddr = segment->mem;
861 while (mbytes) {
862 struct page *page;
863 char *ptr;
864 size_t uchunk, mchunk;
865
866 page = pfn_to_page(maddr >> PAGE_SHIFT);
867 if (!page) {
868 result = -ENOMEM;
869 goto out;
870 }
871 ptr = kmap(page);
872 ptr += maddr & ~PAGE_MASK;
873 mchunk = min_t(size_t, mbytes,
874 PAGE_SIZE - (maddr & ~PAGE_MASK));
875 uchunk = min(ubytes, mchunk);
876 if (mchunk > uchunk) {
877 /* Zero the trailing part of the page */
878 memset(ptr + uchunk, 0, mchunk - uchunk);
879 }
880 result = copy_from_user(ptr, buf, uchunk);
881 kexec_flush_icache_page(page);
882 kunmap(page);
883 if (result) {
884 result = -EFAULT;
885 goto out;
886 }
887 ubytes -= uchunk;
888 maddr += mchunk;
889 buf += mchunk;
890 mbytes -= mchunk;
891 }
892out:
893 return result;
894}
895
896static int kimage_load_segment(struct kimage *image,
897 struct kexec_segment *segment)
898{
899 int result = -ENOMEM;
900
901 switch (image->type) {
902 case KEXEC_TYPE_DEFAULT:
903 result = kimage_load_normal_segment(image, segment);
904 break;
905 case KEXEC_TYPE_CRASH:
906 result = kimage_load_crash_segment(image, segment);
907 break;
908 }
909
910 return result;
911}
912
913/*
914 * Exec Kernel system call: for obvious reasons only root may call it.
915 *
916 * This call breaks up into three pieces.
917 * - A generic part which loads the new kernel from the current
918 * address space, and very carefully places the data in the
919 * allocated pages.
920 *
921 * - A generic part that interacts with the kernel and tells all of
922 * the devices to shut down. Preventing on-going dmas, and placing
923 * the devices in a consistent state so a later kernel can
924 * reinitialize them.
925 *
926 * - A machine specific part that includes the syscall number
927 * and then copies the image to it's final destination. And
928 * jumps into the image at entry.
929 *
930 * kexec does not sync, or unmount filesystems so if you need
931 * that to happen you need to do that yourself.
932 */
933struct kimage *kexec_image;
934struct kimage *kexec_crash_image;
935
936static DEFINE_MUTEX(kexec_mutex);
937
938SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments,
939 struct kexec_segment __user *, segments, unsigned long, flags)
940{
941 struct kimage **dest_image, *image;
942 int result;
943
944 /* We only trust the superuser with rebooting the system. */
945 if (!capable(CAP_SYS_BOOT))
946 return -EPERM;
947
948 /*
949 * Verify we have a legal set of flags
950 * This leaves us room for future extensions.
951 */
952 if ((flags & KEXEC_FLAGS) != (flags & ~KEXEC_ARCH_MASK))
953 return -EINVAL;
954
955 /* Verify we are on the appropriate architecture */
956 if (((flags & KEXEC_ARCH_MASK) != KEXEC_ARCH) &&
957 ((flags & KEXEC_ARCH_MASK) != KEXEC_ARCH_DEFAULT))
958 return -EINVAL;
959
960 /* Put an artificial cap on the number
961 * of segments passed to kexec_load.
962 */
963 if (nr_segments > KEXEC_SEGMENT_MAX)
964 return -EINVAL;
965
966 image = NULL;
967 result = 0;
968
969 /* Because we write directly to the reserved memory
970 * region when loading crash kernels we need a mutex here to
971 * prevent multiple crash kernels from attempting to load
972 * simultaneously, and to prevent a crash kernel from loading
973 * over the top of a in use crash kernel.
974 *
975 * KISS: always take the mutex.
976 */
977 if (!mutex_trylock(&kexec_mutex))
978 return -EBUSY;
979
980 dest_image = &kexec_image;
981 if (flags & KEXEC_ON_CRASH)
982 dest_image = &kexec_crash_image;
983 if (nr_segments > 0) {
984 unsigned long i;
985
986 /* Loading another kernel to reboot into */
987 if ((flags & KEXEC_ON_CRASH) == 0)
988 result = kimage_normal_alloc(&image, entry,
989 nr_segments, segments);
990 /* Loading another kernel to switch to if this one crashes */
991 else if (flags & KEXEC_ON_CRASH) {
992 /* Free any current crash dump kernel before
993 * we corrupt it.
994 */
995 kimage_free(xchg(&kexec_crash_image, NULL));
996 result = kimage_crash_alloc(&image, entry,
997 nr_segments, segments);
998 crash_map_reserved_pages();
999 }
1000 if (result)
1001 goto out;
1002
1003 if (flags & KEXEC_PRESERVE_CONTEXT)
1004 image->preserve_context = 1;
1005 result = machine_kexec_prepare(image);
1006 if (result)
1007 goto out;
1008
1009 for (i = 0; i < nr_segments; i++) {
1010 result = kimage_load_segment(image, &image->segment[i]);
1011 if (result)
1012 goto out;
1013 }
1014 kimage_terminate(image);
1015 if (flags & KEXEC_ON_CRASH)
1016 crash_unmap_reserved_pages();
1017 }
1018 /* Install the new kernel, and Uninstall the old */
1019 image = xchg(dest_image, image);
1020
1021out:
1022 mutex_unlock(&kexec_mutex);
1023 kimage_free(image);
1024
1025 return result;
1026}
1027
1028/*
1029 * Add and remove page tables for crashkernel memory
1030 *
1031 * Provide an empty default implementation here -- architecture
1032 * code may override this
1033 */
1034void __weak crash_map_reserved_pages(void)
1035{}
1036
1037void __weak crash_unmap_reserved_pages(void)
1038{}
1039
1040#ifdef CONFIG_COMPAT
1041asmlinkage long compat_sys_kexec_load(unsigned long entry,
1042 unsigned long nr_segments,
1043 struct compat_kexec_segment __user *segments,
1044 unsigned long flags)
1045{
1046 struct compat_kexec_segment in;
1047 struct kexec_segment out, __user *ksegments;
1048 unsigned long i, result;
1049
1050 /* Don't allow clients that don't understand the native
1051 * architecture to do anything.
1052 */
1053 if ((flags & KEXEC_ARCH_MASK) == KEXEC_ARCH_DEFAULT)
1054 return -EINVAL;
1055
1056 if (nr_segments > KEXEC_SEGMENT_MAX)
1057 return -EINVAL;
1058
1059 ksegments = compat_alloc_user_space(nr_segments * sizeof(out));
1060 for (i=0; i < nr_segments; i++) {
1061 result = copy_from_user(&in, &segments[i], sizeof(in));
1062 if (result)
1063 return -EFAULT;
1064
1065 out.buf = compat_ptr(in.buf);
1066 out.bufsz = in.bufsz;
1067 out.mem = in.mem;
1068 out.memsz = in.memsz;
1069
1070 result = copy_to_user(&ksegments[i], &out, sizeof(out));
1071 if (result)
1072 return -EFAULT;
1073 }
1074
1075 return sys_kexec_load(entry, nr_segments, ksegments, flags);
1076}
1077#endif
1078
1079void crash_kexec(struct pt_regs *regs)
1080{
1081 /* Take the kexec_mutex here to prevent sys_kexec_load
1082 * running on one cpu from replacing the crash kernel
1083 * we are using after a panic on a different cpu.
1084 *
1085 * If the crash kernel was not located in a fixed area
1086 * of memory the xchg(&kexec_crash_image) would be
1087 * sufficient. But since I reuse the memory...
1088 */
1089 if (mutex_trylock(&kexec_mutex)) {
1090 if (kexec_crash_image) {
1091 struct pt_regs fixed_regs;
1092
1093 crash_setup_regs(&fixed_regs, regs);
1094 crash_save_vmcoreinfo();
1095 machine_crash_shutdown(&fixed_regs);
1096 machine_kexec(kexec_crash_image);
1097 }
1098 mutex_unlock(&kexec_mutex);
1099 }
1100}
1101
1102size_t crash_get_memory_size(void)
1103{
1104 size_t size = 0;
1105 mutex_lock(&kexec_mutex);
1106 if (crashk_res.end != crashk_res.start)
1107 size = resource_size(&crashk_res);
1108 mutex_unlock(&kexec_mutex);
1109 return size;
1110}
1111
1112void __weak crash_free_reserved_phys_range(unsigned long begin,
1113 unsigned long end)
1114{
1115 unsigned long addr;
1116
1117 for (addr = begin; addr < end; addr += PAGE_SIZE)
1118 free_reserved_page(pfn_to_page(addr >> PAGE_SHIFT));
1119}
1120
1121int crash_shrink_memory(unsigned long new_size)
1122{
1123 int ret = 0;
1124 unsigned long start, end;
1125 unsigned long old_size;
1126 struct resource *ram_res;
1127
1128 mutex_lock(&kexec_mutex);
1129
1130 if (kexec_crash_image) {
1131 ret = -ENOENT;
1132 goto unlock;
1133 }
1134 start = crashk_res.start;
1135 end = crashk_res.end;
1136 old_size = (end == 0) ? 0 : end - start + 1;
1137 if (new_size >= old_size) {
1138 ret = (new_size == old_size) ? 0 : -EINVAL;
1139 goto unlock;
1140 }
1141
1142 ram_res = kzalloc(sizeof(*ram_res), GFP_KERNEL);
1143 if (!ram_res) {
1144 ret = -ENOMEM;
1145 goto unlock;
1146 }
1147
1148 start = roundup(start, KEXEC_CRASH_MEM_ALIGN);
1149 end = roundup(start + new_size, KEXEC_CRASH_MEM_ALIGN);
1150
1151 crash_map_reserved_pages();
1152 crash_free_reserved_phys_range(end, crashk_res.end);
1153
1154 if ((start == end) && (crashk_res.parent != NULL))
1155 release_resource(&crashk_res);
1156
1157 ram_res->start = end;
1158 ram_res->end = crashk_res.end;
1159 ram_res->flags = IORESOURCE_BUSY | IORESOURCE_MEM;
1160 ram_res->name = "System RAM";
1161
1162 crashk_res.end = end - 1;
1163
1164 insert_resource(&iomem_resource, ram_res);
1165 crash_unmap_reserved_pages();
1166
1167unlock:
1168 mutex_unlock(&kexec_mutex);
1169 return ret;
1170}
1171
1172static u32 *append_elf_note(u32 *buf, char *name, unsigned type, void *data,
1173 size_t data_len)
1174{
1175 struct elf_note note;
1176
1177 note.n_namesz = strlen(name) + 1;
1178 note.n_descsz = data_len;
1179 note.n_type = type;
1180 memcpy(buf, &note, sizeof(note));
1181 buf += (sizeof(note) + 3)/4;
1182 memcpy(buf, name, note.n_namesz);
1183 buf += (note.n_namesz + 3)/4;
1184 memcpy(buf, data, note.n_descsz);
1185 buf += (note.n_descsz + 3)/4;
1186
1187 return buf;
1188}
1189
1190static void final_note(u32 *buf)
1191{
1192 struct elf_note note;
1193
1194 note.n_namesz = 0;
1195 note.n_descsz = 0;
1196 note.n_type = 0;
1197 memcpy(buf, &note, sizeof(note));
1198}
1199
1200void crash_save_cpu(struct pt_regs *regs, int cpu)
1201{
1202 struct elf_prstatus prstatus;
1203 u32 *buf;
1204
1205 if ((cpu < 0) || (cpu >= nr_cpu_ids))
1206 return;
1207
1208 /* Using ELF notes here is opportunistic.
1209 * I need a well defined structure format
1210 * for the data I pass, and I need tags
1211 * on the data to indicate what information I have
1212 * squirrelled away. ELF notes happen to provide
1213 * all of that, so there is no need to invent something new.
1214 */
1215 buf = (u32*)per_cpu_ptr(crash_notes, cpu);
1216 if (!buf)
1217 return;
1218 memset(&prstatus, 0, sizeof(prstatus));
1219 prstatus.pr_pid = current->pid;
1220 elf_core_copy_kernel_regs(&prstatus.pr_reg, regs);
1221 buf = append_elf_note(buf, KEXEC_CORE_NOTE_NAME, NT_PRSTATUS,
1222 &prstatus, sizeof(prstatus));
1223 final_note(buf);
1224}
1225
1226static int __init crash_notes_memory_init(void)
1227{
1228 /* Allocate memory for saving cpu registers. */
1229 crash_notes = alloc_percpu(note_buf_t);
1230 if (!crash_notes) {
1231 printk("Kexec: Memory allocation for saving cpu register"
1232 " states failed\n");
1233 return -ENOMEM;
1234 }
1235 return 0;
1236}
1237module_init(crash_notes_memory_init)
1238
1239
1240/*
1241 * parsing the "crashkernel" commandline
1242 *
1243 * this code is intended to be called from architecture specific code
1244 */
1245
1246
1247/*
1248 * This function parses command lines in the format
1249 *
1250 * crashkernel=ramsize-range:size[,...][@offset]
1251 *
1252 * The function returns 0 on success and -EINVAL on failure.
1253 */
1254static int __init parse_crashkernel_mem(char *cmdline,
1255 unsigned long long system_ram,
1256 unsigned long long *crash_size,
1257 unsigned long long *crash_base)
1258{
1259 char *cur = cmdline, *tmp;
1260
1261 /* for each entry of the comma-separated list */
1262 do {
1263 unsigned long long start, end = ULLONG_MAX, size;
1264
1265 /* get the start of the range */
1266 start = memparse(cur, &tmp);
1267 if (cur == tmp) {
1268 pr_warning("crashkernel: Memory value expected\n");
1269 return -EINVAL;
1270 }
1271 cur = tmp;
1272 if (*cur != '-') {
1273 pr_warning("crashkernel: '-' expected\n");
1274 return -EINVAL;
1275 }
1276 cur++;
1277
1278 /* if no ':' is here, than we read the end */
1279 if (*cur != ':') {
1280 end = memparse(cur, &tmp);
1281 if (cur == tmp) {
1282 pr_warning("crashkernel: Memory "
1283 "value expected\n");
1284 return -EINVAL;
1285 }
1286 cur = tmp;
1287 if (end <= start) {
1288 pr_warning("crashkernel: end <= start\n");
1289 return -EINVAL;
1290 }
1291 }
1292
1293 if (*cur != ':') {
1294 pr_warning("crashkernel: ':' expected\n");
1295 return -EINVAL;
1296 }
1297 cur++;
1298
1299 size = memparse(cur, &tmp);
1300 if (cur == tmp) {
1301 pr_warning("Memory value expected\n");
1302 return -EINVAL;
1303 }
1304 cur = tmp;
1305 if (size >= system_ram) {
1306 pr_warning("crashkernel: invalid size\n");
1307 return -EINVAL;
1308 }
1309
1310 /* match ? */
1311 if (system_ram >= start && system_ram < end) {
1312 *crash_size = size;
1313 break;
1314 }
1315 } while (*cur++ == ',');
1316
1317 if (*crash_size > 0) {
1318 while (*cur && *cur != ' ' && *cur != '@')
1319 cur++;
1320 if (*cur == '@') {
1321 cur++;
1322 *crash_base = memparse(cur, &tmp);
1323 if (cur == tmp) {
1324 pr_warning("Memory value expected "
1325 "after '@'\n");
1326 return -EINVAL;
1327 }
1328 }
1329 }
1330
1331 return 0;
1332}
1333
1334/*
1335 * That function parses "simple" (old) crashkernel command lines like
1336 *
1337 * crashkernel=size[@offset]
1338 *
1339 * It returns 0 on success and -EINVAL on failure.
1340 */
1341static int __init parse_crashkernel_simple(char *cmdline,
1342 unsigned long long *crash_size,
1343 unsigned long long *crash_base)
1344{
1345 char *cur = cmdline;
1346
1347 *crash_size = memparse(cmdline, &cur);
1348 if (cmdline == cur) {
1349 pr_warning("crashkernel: memory value expected\n");
1350 return -EINVAL;
1351 }
1352
1353 if (*cur == '@')
1354 *crash_base = memparse(cur+1, &cur);
1355 else if (*cur != ' ' && *cur != '\0') {
1356 pr_warning("crashkernel: unrecognized char\n");
1357 return -EINVAL;
1358 }
1359
1360 return 0;
1361}
1362
1363#define SUFFIX_HIGH 0
1364#define SUFFIX_LOW 1
1365#define SUFFIX_NULL 2
1366static __initdata char *suffix_tbl[] = {
1367 [SUFFIX_HIGH] = ",high",
1368 [SUFFIX_LOW] = ",low",
1369 [SUFFIX_NULL] = NULL,
1370};
1371
1372/*
1373 * That function parses "suffix" crashkernel command lines like
1374 *
1375 * crashkernel=size,[high|low]
1376 *
1377 * It returns 0 on success and -EINVAL on failure.
1378 */
1379static int __init parse_crashkernel_suffix(char *cmdline,
1380 unsigned long long *crash_size,
1381 unsigned long long *crash_base,
1382 const char *suffix)
1383{
1384 char *cur = cmdline;
1385
1386 *crash_size = memparse(cmdline, &cur);
1387 if (cmdline == cur) {
1388 pr_warn("crashkernel: memory value expected\n");
1389 return -EINVAL;
1390 }
1391
1392 /* check with suffix */
1393 if (strncmp(cur, suffix, strlen(suffix))) {
1394 pr_warn("crashkernel: unrecognized char\n");
1395 return -EINVAL;
1396 }
1397 cur += strlen(suffix);
1398 if (*cur != ' ' && *cur != '\0') {
1399 pr_warn("crashkernel: unrecognized char\n");
1400 return -EINVAL;
1401 }
1402
1403 return 0;
1404}
1405
1406static __init char *get_last_crashkernel(char *cmdline,
1407 const char *name,
1408 const char *suffix)
1409{
1410 char *p = cmdline, *ck_cmdline = NULL;
1411
1412 /* find crashkernel and use the last one if there are more */
1413 p = strstr(p, name);
1414 while (p) {
1415 char *end_p = strchr(p, ' ');
1416 char *q;
1417
1418 if (!end_p)
1419 end_p = p + strlen(p);
1420
1421 if (!suffix) {
1422 int i;
1423
1424 /* skip the one with any known suffix */
1425 for (i = 0; suffix_tbl[i]; i++) {
1426 q = end_p - strlen(suffix_tbl[i]);
1427 if (!strncmp(q, suffix_tbl[i],
1428 strlen(suffix_tbl[i])))
1429 goto next;
1430 }
1431 ck_cmdline = p;
1432 } else {
1433 q = end_p - strlen(suffix);
1434 if (!strncmp(q, suffix, strlen(suffix)))
1435 ck_cmdline = p;
1436 }
1437next:
1438 p = strstr(p+1, name);
1439 }
1440
1441 if (!ck_cmdline)
1442 return NULL;
1443
1444 return ck_cmdline;
1445}
1446
1447static int __init __parse_crashkernel(char *cmdline,
1448 unsigned long long system_ram,
1449 unsigned long long *crash_size,
1450 unsigned long long *crash_base,
1451 const char *name,
1452 const char *suffix)
1453{
1454 char *first_colon, *first_space;
1455 char *ck_cmdline;
1456
1457 BUG_ON(!crash_size || !crash_base);
1458 *crash_size = 0;
1459 *crash_base = 0;
1460
1461 ck_cmdline = get_last_crashkernel(cmdline, name, suffix);
1462
1463 if (!ck_cmdline)
1464 return -EINVAL;
1465
1466 ck_cmdline += strlen(name);
1467
1468 if (suffix)
1469 return parse_crashkernel_suffix(ck_cmdline, crash_size,
1470 crash_base, suffix);
1471 /*
1472 * if the commandline contains a ':', then that's the extended
1473 * syntax -- if not, it must be the classic syntax
1474 */
1475 first_colon = strchr(ck_cmdline, ':');
1476 first_space = strchr(ck_cmdline, ' ');
1477 if (first_colon && (!first_space || first_colon < first_space))
1478 return parse_crashkernel_mem(ck_cmdline, system_ram,
1479 crash_size, crash_base);
1480
1481 return parse_crashkernel_simple(ck_cmdline, crash_size, crash_base);
1482}
1483
1484/*
1485 * That function is the entry point for command line parsing and should be
1486 * called from the arch-specific code.
1487 */
1488int __init parse_crashkernel(char *cmdline,
1489 unsigned long long system_ram,
1490 unsigned long long *crash_size,
1491 unsigned long long *crash_base)
1492{
1493 return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base,
1494 "crashkernel=", NULL);
1495}
1496
1497int __init parse_crashkernel_high(char *cmdline,
1498 unsigned long long system_ram,
1499 unsigned long long *crash_size,
1500 unsigned long long *crash_base)
1501{
1502 return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base,
1503 "crashkernel=", suffix_tbl[SUFFIX_HIGH]);
1504}
1505
1506int __init parse_crashkernel_low(char *cmdline,
1507 unsigned long long system_ram,
1508 unsigned long long *crash_size,
1509 unsigned long long *crash_base)
1510{
1511 return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base,
1512 "crashkernel=", suffix_tbl[SUFFIX_LOW]);
1513}
1514
1515static void update_vmcoreinfo_note(void)
1516{
1517 u32 *buf = vmcoreinfo_note;
1518
1519 if (!vmcoreinfo_size)
1520 return;
1521 buf = append_elf_note(buf, VMCOREINFO_NOTE_NAME, 0, vmcoreinfo_data,
1522 vmcoreinfo_size);
1523 final_note(buf);
1524}
1525
1526void crash_save_vmcoreinfo(void)
1527{
1528 vmcoreinfo_append_str("CRASHTIME=%ld\n", get_seconds());
1529 update_vmcoreinfo_note();
1530}
1531
1532void vmcoreinfo_append_str(const char *fmt, ...)
1533{
1534 va_list args;
1535 char buf[0x50];
1536 size_t r;
1537
1538 va_start(args, fmt);
1539 r = vsnprintf(buf, sizeof(buf), fmt, args);
1540 va_end(args);
1541
1542 r = min(r, vmcoreinfo_max_size - vmcoreinfo_size);
1543
1544 memcpy(&vmcoreinfo_data[vmcoreinfo_size], buf, r);
1545
1546 vmcoreinfo_size += r;
1547}
1548
1549/*
1550 * provide an empty default implementation here -- architecture
1551 * code may override this
1552 */
1553void __attribute__ ((weak)) arch_crash_save_vmcoreinfo(void)
1554{}
1555
1556unsigned long __attribute__ ((weak)) paddr_vmcoreinfo_note(void)
1557{
1558 return __pa((unsigned long)(char *)&vmcoreinfo_note);
1559}
1560
1561static int __init crash_save_vmcoreinfo_init(void)
1562{
1563 VMCOREINFO_OSRELEASE(init_uts_ns.name.release);
1564 VMCOREINFO_PAGESIZE(PAGE_SIZE);
1565
1566 VMCOREINFO_SYMBOL(init_uts_ns);
1567 VMCOREINFO_SYMBOL(node_online_map);
1568#ifdef CONFIG_MMU
1569 VMCOREINFO_SYMBOL(swapper_pg_dir);
1570#endif
1571 VMCOREINFO_SYMBOL(_stext);
1572 VMCOREINFO_SYMBOL(vmap_area_list);
1573
1574#ifndef CONFIG_NEED_MULTIPLE_NODES
1575 VMCOREINFO_SYMBOL(mem_map);
1576 VMCOREINFO_SYMBOL(contig_page_data);
1577#endif
1578#ifdef CONFIG_SPARSEMEM
1579 VMCOREINFO_SYMBOL(mem_section);
1580 VMCOREINFO_LENGTH(mem_section, NR_SECTION_ROOTS);
1581 VMCOREINFO_STRUCT_SIZE(mem_section);
1582 VMCOREINFO_OFFSET(mem_section, section_mem_map);
1583#endif
1584 VMCOREINFO_STRUCT_SIZE(page);
1585 VMCOREINFO_STRUCT_SIZE(pglist_data);
1586 VMCOREINFO_STRUCT_SIZE(zone);
1587 VMCOREINFO_STRUCT_SIZE(free_area);
1588 VMCOREINFO_STRUCT_SIZE(list_head);
1589 VMCOREINFO_SIZE(nodemask_t);
1590 VMCOREINFO_OFFSET(page, flags);
1591 VMCOREINFO_OFFSET(page, _count);
1592 VMCOREINFO_OFFSET(page, mapping);
1593 VMCOREINFO_OFFSET(page, lru);
1594 VMCOREINFO_OFFSET(page, _mapcount);
1595 VMCOREINFO_OFFSET(page, private);
1596 VMCOREINFO_OFFSET(pglist_data, node_zones);
1597 VMCOREINFO_OFFSET(pglist_data, nr_zones);
1598#ifdef CONFIG_FLAT_NODE_MEM_MAP
1599 VMCOREINFO_OFFSET(pglist_data, node_mem_map);
1600#endif
1601 VMCOREINFO_OFFSET(pglist_data, node_start_pfn);
1602 VMCOREINFO_OFFSET(pglist_data, node_spanned_pages);
1603 VMCOREINFO_OFFSET(pglist_data, node_id);
1604 VMCOREINFO_OFFSET(zone, free_area);
1605 VMCOREINFO_OFFSET(zone, vm_stat);
1606 VMCOREINFO_OFFSET(zone, spanned_pages);
1607 VMCOREINFO_OFFSET(free_area, free_list);
1608 VMCOREINFO_OFFSET(list_head, next);
1609 VMCOREINFO_OFFSET(list_head, prev);
1610 VMCOREINFO_OFFSET(vmap_area, va_start);
1611 VMCOREINFO_OFFSET(vmap_area, list);
1612 VMCOREINFO_LENGTH(zone.free_area, MAX_ORDER);
1613 log_buf_kexec_setup();
1614 VMCOREINFO_LENGTH(free_area.free_list, MIGRATE_TYPES);
1615 VMCOREINFO_NUMBER(NR_FREE_PAGES);
1616 VMCOREINFO_NUMBER(PG_lru);
1617 VMCOREINFO_NUMBER(PG_private);
1618 VMCOREINFO_NUMBER(PG_swapcache);
1619 VMCOREINFO_NUMBER(PG_slab);
1620#ifdef CONFIG_MEMORY_FAILURE
1621 VMCOREINFO_NUMBER(PG_hwpoison);
1622#endif
1623 VMCOREINFO_NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE);
1624
1625 arch_crash_save_vmcoreinfo();
1626 update_vmcoreinfo_note();
1627
1628 return 0;
1629}
1630
1631module_init(crash_save_vmcoreinfo_init)
1632
1633/*
1634 * Move into place and start executing a preloaded standalone
1635 * executable. If nothing was preloaded return an error.
1636 */
1637int kernel_kexec(void)
1638{
1639 int error = 0;
1640
1641 if (!mutex_trylock(&kexec_mutex))
1642 return -EBUSY;
1643 if (!kexec_image) {
1644 error = -EINVAL;
1645 goto Unlock;
1646 }
1647
1648#ifdef CONFIG_KEXEC_JUMP
1649 if (kexec_image->preserve_context) {
1650 lock_system_sleep();
1651 pm_prepare_console();
1652 error = freeze_processes();
1653 if (error) {
1654 error = -EBUSY;
1655 goto Restore_console;
1656 }
1657 suspend_console();
1658 error = dpm_suspend_start(PMSG_FREEZE);
1659 if (error)
1660 goto Resume_console;
1661 /* At this point, dpm_suspend_start() has been called,
1662 * but *not* dpm_suspend_end(). We *must* call
1663 * dpm_suspend_end() now. Otherwise, drivers for
1664 * some devices (e.g. interrupt controllers) become
1665 * desynchronized with the actual state of the
1666 * hardware at resume time, and evil weirdness ensues.
1667 */
1668 error = dpm_suspend_end(PMSG_FREEZE);
1669 if (error)
1670 goto Resume_devices;
1671 error = disable_nonboot_cpus();
1672 if (error)
1673 goto Enable_cpus;
1674 local_irq_disable();
1675 error = syscore_suspend();
1676 if (error)
1677 goto Enable_irqs;
1678 } else
1679#endif
1680 {
1681 kexec_in_progress = true;
1682 kernel_restart_prepare(NULL);
1683 migrate_to_reboot_cpu();
1684 printk(KERN_EMERG "Starting new kernel\n");
1685 machine_shutdown();
1686 }
1687
1688 machine_kexec(kexec_image);
1689
1690#ifdef CONFIG_KEXEC_JUMP
1691 if (kexec_image->preserve_context) {
1692 syscore_resume();
1693 Enable_irqs:
1694 local_irq_enable();
1695 Enable_cpus:
1696 enable_nonboot_cpus();
1697 dpm_resume_start(PMSG_RESTORE);
1698 Resume_devices:
1699 dpm_resume_end(PMSG_RESTORE);
1700 Resume_console:
1701 resume_console();
1702 thaw_processes();
1703 Restore_console:
1704 pm_restore_console();
1705 unlock_system_sleep();
1706 }
1707#endif
1708
1709 Unlock:
1710 mutex_unlock(&kexec_mutex);
1711 return error;
1712}