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1 | /* |
2 | * kexec.c - kexec system call |
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 | |
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. */ |
42 | note_buf_t __percpu *crash_notes; |
43 | |
44 | /* vmcoreinfo stuff */ |
45 | static unsigned char vmcoreinfo_data[VMCOREINFO_BYTES]; |
46 | u32 vmcoreinfo_note[VMCOREINFO_NOTE_SIZE/4]; |
47 | size_t vmcoreinfo_size; |
48 | size_t vmcoreinfo_max_size = sizeof(vmcoreinfo_data); |
49 | |
50 | /* Flag to indicate we are going to kexec a new kernel */ |
51 | bool kexec_in_progress = false; |
52 | |
53 | /* Location of the reserved area for the crash kernel */ |
54 | struct resource crashk_res = { |
55 | .name = "Crash kernel", |
56 | .start = 0, |
57 | .end = 0, |
58 | .flags = IORESOURCE_BUSY | IORESOURCE_MEM |
59 | }; |
60 | struct resource crashk_low_res = { |
61 | .name = "Crash kernel", |
62 | .start = 0, |
63 | .end = 0, |
64 | .flags = IORESOURCE_BUSY | IORESOURCE_MEM |
65 | }; |
66 | |
67 | int 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 | |
120 | static int kimage_is_destination_range(struct kimage *image, |
121 | unsigned long start, unsigned long end); |
122 | static struct page *kimage_alloc_page(struct kimage *image, |
123 | gfp_t gfp_mask, |
124 | unsigned long dest); |
125 | |
126 | static 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; |
225 | out: |
226 | if (result == 0) |
227 | *rimage = image; |
228 | else |
229 | kfree(image); |
230 | |
231 | return result; |
232 | |
233 | } |
234 | |
235 | static void kimage_free_page_list(struct list_head *list); |
236 | |
237 | static 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 | |
272 | out_free: |
273 | kimage_free_page_list(&image->control_pages); |
274 | kfree(image); |
275 | out: |
276 | return result; |
277 | } |
278 | |
279 | static 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 | |
341 | out_free: |
342 | kfree(image); |
343 | out: |
344 | return result; |
345 | } |
346 | |
347 | static 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 | |
365 | static 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 | |
382 | static 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 | |
393 | static 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 | |
406 | static 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 | |
472 | static 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 | |
534 | struct 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 | |
551 | static 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 | |
577 | static 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 | |
591 | static 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 | |
604 | static 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 | } |
613 | static 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 | |
626 | static 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 | |
634 | static 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 | |
668 | static 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 | |
687 | static 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 | |
788 | static 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 | } |
840 | out: |
841 | return result; |
842 | } |
843 | |
844 | static 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 | } |
892 | out: |
893 | return result; |
894 | } |
895 | |
896 | static 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 | */ |
933 | struct kimage *kexec_image; |
934 | struct kimage *kexec_crash_image; |
935 | |
936 | static DEFINE_MUTEX(kexec_mutex); |
937 | |
938 | SYSCALL_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 | |
1021 | out: |
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 | */ |
1034 | void __weak crash_map_reserved_pages(void) |
1035 | {} |
1036 | |
1037 | void __weak crash_unmap_reserved_pages(void) |
1038 | {} |
1039 | |
1040 | #ifdef CONFIG_COMPAT |
1041 | asmlinkage 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 | |
1079 | void 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 | |
1102 | size_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 | |
1112 | void __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 | |
1121 | int 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 | |
1167 | unlock: |
1168 | mutex_unlock(&kexec_mutex); |
1169 | return ret; |
1170 | } |
1171 | |
1172 | static 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, ¬e, 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 | |
1190 | static 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, ¬e, sizeof(note)); |
1198 | } |
1199 | |
1200 | void 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 | |
1226 | static 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 | } |
1237 | module_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 | */ |
1254 | static 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 | */ |
1341 | static 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 |
1366 | static __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 | */ |
1379 | static 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 | |
1406 | static __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 | } |
1437 | next: |
1438 | p = strstr(p+1, name); |
1439 | } |
1440 | |
1441 | if (!ck_cmdline) |
1442 | return NULL; |
1443 | |
1444 | return ck_cmdline; |
1445 | } |
1446 | |
1447 | static 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 | */ |
1488 | int __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 | |
1497 | int __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 | |
1506 | int __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 | |
1515 | static 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 | |
1526 | void crash_save_vmcoreinfo(void) |
1527 | { |
1528 | vmcoreinfo_append_str("CRASHTIME=%ld\n", get_seconds()); |
1529 | update_vmcoreinfo_note(); |
1530 | } |
1531 | |
1532 | void 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 | */ |
1553 | void __attribute__ ((weak)) arch_crash_save_vmcoreinfo(void) |
1554 | {} |
1555 | |
1556 | unsigned long __attribute__ ((weak)) paddr_vmcoreinfo_note(void) |
1557 | { |
1558 | return __pa((unsigned long)(char *)&vmcoreinfo_note); |
1559 | } |
1560 | |
1561 | static 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 | |
1631 | module_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 | */ |
1637 | int 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 | } |
1713 |
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Tags:
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v2.6.34-rc5
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