Commit | Line | Data |
---|---|---|
40b0b3f8 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
2965faa5 DY |
2 | /* |
3 | * kexec.c - kexec system call core code. | |
4 | * Copyright (C) 2002-2004 Eric Biederman <ebiederm@xmission.com> | |
2965faa5 DY |
5 | */ |
6 | ||
de90a6bc | 7 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
2965faa5 DY |
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/uaccess.h> | |
32 | #include <linux/io.h> | |
33 | #include <linux/console.h> | |
34 | #include <linux/vmalloc.h> | |
35 | #include <linux/swap.h> | |
36 | #include <linux/syscore_ops.h> | |
37 | #include <linux/compiler.h> | |
38 | #include <linux/hugetlb.h> | |
c207aee4 | 39 | #include <linux/frame.h> |
2965faa5 DY |
40 | |
41 | #include <asm/page.h> | |
42 | #include <asm/sections.h> | |
43 | ||
44 | #include <crypto/hash.h> | |
45 | #include <crypto/sha.h> | |
46 | #include "kexec_internal.h" | |
47 | ||
48 | DEFINE_MUTEX(kexec_mutex); | |
49 | ||
50 | /* Per cpu memory for storing cpu states in case of system crash. */ | |
51 | note_buf_t __percpu *crash_notes; | |
52 | ||
2965faa5 DY |
53 | /* Flag to indicate we are going to kexec a new kernel */ |
54 | bool kexec_in_progress = false; | |
55 | ||
56 | ||
57 | /* Location of the reserved area for the crash kernel */ | |
58 | struct resource crashk_res = { | |
59 | .name = "Crash kernel", | |
60 | .start = 0, | |
61 | .end = 0, | |
1a085d07 TK |
62 | .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM, |
63 | .desc = IORES_DESC_CRASH_KERNEL | |
2965faa5 DY |
64 | }; |
65 | struct resource crashk_low_res = { | |
66 | .name = "Crash kernel", | |
67 | .start = 0, | |
68 | .end = 0, | |
1a085d07 TK |
69 | .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM, |
70 | .desc = IORES_DESC_CRASH_KERNEL | |
2965faa5 DY |
71 | }; |
72 | ||
73 | int kexec_should_crash(struct task_struct *p) | |
74 | { | |
75 | /* | |
76 | * If crash_kexec_post_notifiers is enabled, don't run | |
77 | * crash_kexec() here yet, which must be run after panic | |
78 | * notifiers in panic(). | |
79 | */ | |
80 | if (crash_kexec_post_notifiers) | |
81 | return 0; | |
82 | /* | |
83 | * There are 4 panic() calls in do_exit() path, each of which | |
84 | * corresponds to each of these 4 conditions. | |
85 | */ | |
86 | if (in_interrupt() || !p->pid || is_global_init(p) || panic_on_oops) | |
87 | return 1; | |
88 | return 0; | |
89 | } | |
90 | ||
21db79e8 PT |
91 | int kexec_crash_loaded(void) |
92 | { | |
93 | return !!kexec_crash_image; | |
94 | } | |
95 | EXPORT_SYMBOL_GPL(kexec_crash_loaded); | |
96 | ||
2965faa5 DY |
97 | /* |
98 | * When kexec transitions to the new kernel there is a one-to-one | |
99 | * mapping between physical and virtual addresses. On processors | |
100 | * where you can disable the MMU this is trivial, and easy. For | |
101 | * others it is still a simple predictable page table to setup. | |
102 | * | |
103 | * In that environment kexec copies the new kernel to its final | |
104 | * resting place. This means I can only support memory whose | |
105 | * physical address can fit in an unsigned long. In particular | |
106 | * addresses where (pfn << PAGE_SHIFT) > ULONG_MAX cannot be handled. | |
107 | * If the assembly stub has more restrictive requirements | |
108 | * KEXEC_SOURCE_MEMORY_LIMIT and KEXEC_DEST_MEMORY_LIMIT can be | |
109 | * defined more restrictively in <asm/kexec.h>. | |
110 | * | |
111 | * The code for the transition from the current kernel to the | |
112 | * the new kernel is placed in the control_code_buffer, whose size | |
113 | * is given by KEXEC_CONTROL_PAGE_SIZE. In the best case only a single | |
114 | * page of memory is necessary, but some architectures require more. | |
115 | * Because this memory must be identity mapped in the transition from | |
116 | * virtual to physical addresses it must live in the range | |
117 | * 0 - TASK_SIZE, as only the user space mappings are arbitrarily | |
118 | * modifiable. | |
119 | * | |
120 | * The assembly stub in the control code buffer is passed a linked list | |
121 | * of descriptor pages detailing the source pages of the new kernel, | |
122 | * and the destination addresses of those source pages. As this data | |
123 | * structure is not used in the context of the current OS, it must | |
124 | * be self-contained. | |
125 | * | |
126 | * The code has been made to work with highmem pages and will use a | |
127 | * destination page in its final resting place (if it happens | |
128 | * to allocate it). The end product of this is that most of the | |
129 | * physical address space, and most of RAM can be used. | |
130 | * | |
131 | * Future directions include: | |
132 | * - allocating a page table with the control code buffer identity | |
133 | * mapped, to simplify machine_kexec and make kexec_on_panic more | |
134 | * reliable. | |
135 | */ | |
136 | ||
137 | /* | |
138 | * KIMAGE_NO_DEST is an impossible destination address..., for | |
139 | * allocating pages whose destination address we do not care about. | |
140 | */ | |
141 | #define KIMAGE_NO_DEST (-1UL) | |
1730f146 | 142 | #define PAGE_COUNT(x) (((x) + PAGE_SIZE - 1) >> PAGE_SHIFT) |
2965faa5 DY |
143 | |
144 | static struct page *kimage_alloc_page(struct kimage *image, | |
145 | gfp_t gfp_mask, | |
146 | unsigned long dest); | |
147 | ||
148 | int sanity_check_segment_list(struct kimage *image) | |
149 | { | |
4caf9615 | 150 | int i; |
2965faa5 | 151 | unsigned long nr_segments = image->nr_segments; |
1730f146 | 152 | unsigned long total_pages = 0; |
ca79b0c2 | 153 | unsigned long nr_pages = totalram_pages(); |
2965faa5 DY |
154 | |
155 | /* | |
156 | * Verify we have good destination addresses. The caller is | |
157 | * responsible for making certain we don't attempt to load | |
158 | * the new image into invalid or reserved areas of RAM. This | |
159 | * just verifies it is an address we can use. | |
160 | * | |
161 | * Since the kernel does everything in page size chunks ensure | |
162 | * the destination addresses are page aligned. Too many | |
163 | * special cases crop of when we don't do this. The most | |
164 | * insidious is getting overlapping destination addresses | |
165 | * simply because addresses are changed to page size | |
166 | * granularity. | |
167 | */ | |
2965faa5 DY |
168 | for (i = 0; i < nr_segments; i++) { |
169 | unsigned long mstart, mend; | |
170 | ||
171 | mstart = image->segment[i].mem; | |
172 | mend = mstart + image->segment[i].memsz; | |
465d3777 RK |
173 | if (mstart > mend) |
174 | return -EADDRNOTAVAIL; | |
2965faa5 | 175 | if ((mstart & ~PAGE_MASK) || (mend & ~PAGE_MASK)) |
4caf9615 | 176 | return -EADDRNOTAVAIL; |
2965faa5 | 177 | if (mend >= KEXEC_DESTINATION_MEMORY_LIMIT) |
4caf9615 | 178 | return -EADDRNOTAVAIL; |
2965faa5 DY |
179 | } |
180 | ||
181 | /* Verify our destination addresses do not overlap. | |
182 | * If we alloed overlapping destination addresses | |
183 | * through very weird things can happen with no | |
184 | * easy explanation as one segment stops on another. | |
185 | */ | |
2965faa5 DY |
186 | for (i = 0; i < nr_segments; i++) { |
187 | unsigned long mstart, mend; | |
188 | unsigned long j; | |
189 | ||
190 | mstart = image->segment[i].mem; | |
191 | mend = mstart + image->segment[i].memsz; | |
192 | for (j = 0; j < i; j++) { | |
193 | unsigned long pstart, pend; | |
194 | ||
195 | pstart = image->segment[j].mem; | |
196 | pend = pstart + image->segment[j].memsz; | |
197 | /* Do the segments overlap ? */ | |
198 | if ((mend > pstart) && (mstart < pend)) | |
4caf9615 | 199 | return -EINVAL; |
2965faa5 DY |
200 | } |
201 | } | |
202 | ||
203 | /* Ensure our buffer sizes are strictly less than | |
204 | * our memory sizes. This should always be the case, | |
205 | * and it is easier to check up front than to be surprised | |
206 | * later on. | |
207 | */ | |
2965faa5 DY |
208 | for (i = 0; i < nr_segments; i++) { |
209 | if (image->segment[i].bufsz > image->segment[i].memsz) | |
4caf9615 | 210 | return -EINVAL; |
2965faa5 DY |
211 | } |
212 | ||
1730f146 | 213 | /* |
214 | * Verify that no more than half of memory will be consumed. If the | |
215 | * request from userspace is too large, a large amount of time will be | |
216 | * wasted allocating pages, which can cause a soft lockup. | |
217 | */ | |
218 | for (i = 0; i < nr_segments; i++) { | |
3d6357de | 219 | if (PAGE_COUNT(image->segment[i].memsz) > nr_pages / 2) |
1730f146 | 220 | return -EINVAL; |
221 | ||
222 | total_pages += PAGE_COUNT(image->segment[i].memsz); | |
223 | } | |
224 | ||
3d6357de | 225 | if (total_pages > nr_pages / 2) |
1730f146 | 226 | return -EINVAL; |
227 | ||
2965faa5 DY |
228 | /* |
229 | * Verify we have good destination addresses. Normally | |
230 | * the caller is responsible for making certain we don't | |
231 | * attempt to load the new image into invalid or reserved | |
232 | * areas of RAM. But crash kernels are preloaded into a | |
233 | * reserved area of ram. We must ensure the addresses | |
234 | * are in the reserved area otherwise preloading the | |
235 | * kernel could corrupt things. | |
236 | */ | |
237 | ||
238 | if (image->type == KEXEC_TYPE_CRASH) { | |
2965faa5 DY |
239 | for (i = 0; i < nr_segments; i++) { |
240 | unsigned long mstart, mend; | |
241 | ||
242 | mstart = image->segment[i].mem; | |
243 | mend = mstart + image->segment[i].memsz - 1; | |
244 | /* Ensure we are within the crash kernel limits */ | |
43546d86 RK |
245 | if ((mstart < phys_to_boot_phys(crashk_res.start)) || |
246 | (mend > phys_to_boot_phys(crashk_res.end))) | |
4caf9615 | 247 | return -EADDRNOTAVAIL; |
2965faa5 DY |
248 | } |
249 | } | |
250 | ||
251 | return 0; | |
252 | } | |
253 | ||
254 | struct kimage *do_kimage_alloc_init(void) | |
255 | { | |
256 | struct kimage *image; | |
257 | ||
258 | /* Allocate a controlling structure */ | |
259 | image = kzalloc(sizeof(*image), GFP_KERNEL); | |
260 | if (!image) | |
261 | return NULL; | |
262 | ||
263 | image->head = 0; | |
264 | image->entry = &image->head; | |
265 | image->last_entry = &image->head; | |
266 | image->control_page = ~0; /* By default this does not apply */ | |
267 | image->type = KEXEC_TYPE_DEFAULT; | |
268 | ||
269 | /* Initialize the list of control pages */ | |
270 | INIT_LIST_HEAD(&image->control_pages); | |
271 | ||
272 | /* Initialize the list of destination pages */ | |
273 | INIT_LIST_HEAD(&image->dest_pages); | |
274 | ||
275 | /* Initialize the list of unusable pages */ | |
276 | INIT_LIST_HEAD(&image->unusable_pages); | |
277 | ||
278 | return image; | |
279 | } | |
280 | ||
281 | int kimage_is_destination_range(struct kimage *image, | |
282 | unsigned long start, | |
283 | unsigned long end) | |
284 | { | |
285 | unsigned long i; | |
286 | ||
287 | for (i = 0; i < image->nr_segments; i++) { | |
288 | unsigned long mstart, mend; | |
289 | ||
290 | mstart = image->segment[i].mem; | |
291 | mend = mstart + image->segment[i].memsz; | |
292 | if ((end > mstart) && (start < mend)) | |
293 | return 1; | |
294 | } | |
295 | ||
296 | return 0; | |
297 | } | |
298 | ||
299 | static struct page *kimage_alloc_pages(gfp_t gfp_mask, unsigned int order) | |
300 | { | |
301 | struct page *pages; | |
302 | ||
bba4ed01 | 303 | pages = alloc_pages(gfp_mask & ~__GFP_ZERO, order); |
2965faa5 DY |
304 | if (pages) { |
305 | unsigned int count, i; | |
306 | ||
307 | pages->mapping = NULL; | |
308 | set_page_private(pages, order); | |
309 | count = 1 << order; | |
310 | for (i = 0; i < count; i++) | |
311 | SetPageReserved(pages + i); | |
bba4ed01 TL |
312 | |
313 | arch_kexec_post_alloc_pages(page_address(pages), count, | |
314 | gfp_mask); | |
315 | ||
316 | if (gfp_mask & __GFP_ZERO) | |
317 | for (i = 0; i < count; i++) | |
318 | clear_highpage(pages + i); | |
2965faa5 DY |
319 | } |
320 | ||
321 | return pages; | |
322 | } | |
323 | ||
324 | static void kimage_free_pages(struct page *page) | |
325 | { | |
326 | unsigned int order, count, i; | |
327 | ||
328 | order = page_private(page); | |
329 | count = 1 << order; | |
bba4ed01 TL |
330 | |
331 | arch_kexec_pre_free_pages(page_address(page), count); | |
332 | ||
2965faa5 DY |
333 | for (i = 0; i < count; i++) |
334 | ClearPageReserved(page + i); | |
335 | __free_pages(page, order); | |
336 | } | |
337 | ||
338 | void kimage_free_page_list(struct list_head *list) | |
339 | { | |
2b24692b | 340 | struct page *page, *next; |
2965faa5 | 341 | |
2b24692b | 342 | list_for_each_entry_safe(page, next, list, lru) { |
2965faa5 DY |
343 | list_del(&page->lru); |
344 | kimage_free_pages(page); | |
345 | } | |
346 | } | |
347 | ||
348 | static struct page *kimage_alloc_normal_control_pages(struct kimage *image, | |
349 | unsigned int order) | |
350 | { | |
351 | /* Control pages are special, they are the intermediaries | |
352 | * that are needed while we copy the rest of the pages | |
353 | * to their final resting place. As such they must | |
354 | * not conflict with either the destination addresses | |
355 | * or memory the kernel is already using. | |
356 | * | |
357 | * The only case where we really need more than one of | |
358 | * these are for architectures where we cannot disable | |
359 | * the MMU and must instead generate an identity mapped | |
360 | * page table for all of the memory. | |
361 | * | |
362 | * At worst this runs in O(N) of the image size. | |
363 | */ | |
364 | struct list_head extra_pages; | |
365 | struct page *pages; | |
366 | unsigned int count; | |
367 | ||
368 | count = 1 << order; | |
369 | INIT_LIST_HEAD(&extra_pages); | |
370 | ||
371 | /* Loop while I can allocate a page and the page allocated | |
372 | * is a destination page. | |
373 | */ | |
374 | do { | |
375 | unsigned long pfn, epfn, addr, eaddr; | |
376 | ||
377 | pages = kimage_alloc_pages(KEXEC_CONTROL_MEMORY_GFP, order); | |
378 | if (!pages) | |
379 | break; | |
43546d86 | 380 | pfn = page_to_boot_pfn(pages); |
2965faa5 DY |
381 | epfn = pfn + count; |
382 | addr = pfn << PAGE_SHIFT; | |
383 | eaddr = epfn << PAGE_SHIFT; | |
384 | if ((epfn >= (KEXEC_CONTROL_MEMORY_LIMIT >> PAGE_SHIFT)) || | |
385 | kimage_is_destination_range(image, addr, eaddr)) { | |
386 | list_add(&pages->lru, &extra_pages); | |
387 | pages = NULL; | |
388 | } | |
389 | } while (!pages); | |
390 | ||
391 | if (pages) { | |
392 | /* Remember the allocated page... */ | |
393 | list_add(&pages->lru, &image->control_pages); | |
394 | ||
395 | /* Because the page is already in it's destination | |
396 | * location we will never allocate another page at | |
397 | * that address. Therefore kimage_alloc_pages | |
398 | * will not return it (again) and we don't need | |
399 | * to give it an entry in image->segment[]. | |
400 | */ | |
401 | } | |
402 | /* Deal with the destination pages I have inadvertently allocated. | |
403 | * | |
404 | * Ideally I would convert multi-page allocations into single | |
405 | * page allocations, and add everything to image->dest_pages. | |
406 | * | |
407 | * For now it is simpler to just free the pages. | |
408 | */ | |
409 | kimage_free_page_list(&extra_pages); | |
410 | ||
411 | return pages; | |
412 | } | |
413 | ||
414 | static struct page *kimage_alloc_crash_control_pages(struct kimage *image, | |
415 | unsigned int order) | |
416 | { | |
417 | /* Control pages are special, they are the intermediaries | |
418 | * that are needed while we copy the rest of the pages | |
419 | * to their final resting place. As such they must | |
420 | * not conflict with either the destination addresses | |
421 | * or memory the kernel is already using. | |
422 | * | |
423 | * Control pages are also the only pags we must allocate | |
424 | * when loading a crash kernel. All of the other pages | |
425 | * are specified by the segments and we just memcpy | |
426 | * into them directly. | |
427 | * | |
428 | * The only case where we really need more than one of | |
429 | * these are for architectures where we cannot disable | |
430 | * the MMU and must instead generate an identity mapped | |
431 | * page table for all of the memory. | |
432 | * | |
433 | * Given the low demand this implements a very simple | |
434 | * allocator that finds the first hole of the appropriate | |
435 | * size in the reserved memory region, and allocates all | |
436 | * of the memory up to and including the hole. | |
437 | */ | |
438 | unsigned long hole_start, hole_end, size; | |
439 | struct page *pages; | |
440 | ||
441 | pages = NULL; | |
442 | size = (1 << order) << PAGE_SHIFT; | |
443 | hole_start = (image->control_page + (size - 1)) & ~(size - 1); | |
444 | hole_end = hole_start + size - 1; | |
445 | while (hole_end <= crashk_res.end) { | |
446 | unsigned long i; | |
447 | ||
8e53c073 | 448 | cond_resched(); |
449 | ||
2965faa5 DY |
450 | if (hole_end > KEXEC_CRASH_CONTROL_MEMORY_LIMIT) |
451 | break; | |
452 | /* See if I overlap any of the segments */ | |
453 | for (i = 0; i < image->nr_segments; i++) { | |
454 | unsigned long mstart, mend; | |
455 | ||
456 | mstart = image->segment[i].mem; | |
457 | mend = mstart + image->segment[i].memsz - 1; | |
458 | if ((hole_end >= mstart) && (hole_start <= mend)) { | |
459 | /* Advance the hole to the end of the segment */ | |
460 | hole_start = (mend + (size - 1)) & ~(size - 1); | |
461 | hole_end = hole_start + size - 1; | |
462 | break; | |
463 | } | |
464 | } | |
465 | /* If I don't overlap any segments I have found my hole! */ | |
466 | if (i == image->nr_segments) { | |
467 | pages = pfn_to_page(hole_start >> PAGE_SHIFT); | |
04e9949b | 468 | image->control_page = hole_end; |
2965faa5 DY |
469 | break; |
470 | } | |
471 | } | |
2965faa5 | 472 | |
9cf38d55 LJ |
473 | /* Ensure that these pages are decrypted if SME is enabled. */ |
474 | if (pages) | |
475 | arch_kexec_post_alloc_pages(page_address(pages), 1 << order, 0); | |
476 | ||
2965faa5 DY |
477 | return pages; |
478 | } | |
479 | ||
480 | ||
481 | struct page *kimage_alloc_control_pages(struct kimage *image, | |
482 | unsigned int order) | |
483 | { | |
484 | struct page *pages = NULL; | |
485 | ||
486 | switch (image->type) { | |
487 | case KEXEC_TYPE_DEFAULT: | |
488 | pages = kimage_alloc_normal_control_pages(image, order); | |
489 | break; | |
490 | case KEXEC_TYPE_CRASH: | |
491 | pages = kimage_alloc_crash_control_pages(image, order); | |
492 | break; | |
493 | } | |
494 | ||
495 | return pages; | |
496 | } | |
497 | ||
1229384f XP |
498 | int kimage_crash_copy_vmcoreinfo(struct kimage *image) |
499 | { | |
500 | struct page *vmcoreinfo_page; | |
501 | void *safecopy; | |
502 | ||
503 | if (image->type != KEXEC_TYPE_CRASH) | |
504 | return 0; | |
505 | ||
506 | /* | |
507 | * For kdump, allocate one vmcoreinfo safe copy from the | |
508 | * crash memory. as we have arch_kexec_protect_crashkres() | |
509 | * after kexec syscall, we naturally protect it from write | |
510 | * (even read) access under kernel direct mapping. But on | |
511 | * the other hand, we still need to operate it when crash | |
512 | * happens to generate vmcoreinfo note, hereby we rely on | |
513 | * vmap for this purpose. | |
514 | */ | |
515 | vmcoreinfo_page = kimage_alloc_control_pages(image, 0); | |
516 | if (!vmcoreinfo_page) { | |
517 | pr_warn("Could not allocate vmcoreinfo buffer\n"); | |
518 | return -ENOMEM; | |
519 | } | |
520 | safecopy = vmap(&vmcoreinfo_page, 1, VM_MAP, PAGE_KERNEL); | |
521 | if (!safecopy) { | |
522 | pr_warn("Could not vmap vmcoreinfo buffer\n"); | |
523 | return -ENOMEM; | |
524 | } | |
525 | ||
526 | image->vmcoreinfo_data_copy = safecopy; | |
527 | crash_update_vmcoreinfo_safecopy(safecopy); | |
528 | ||
529 | return 0; | |
530 | } | |
531 | ||
2965faa5 DY |
532 | static int kimage_add_entry(struct kimage *image, kimage_entry_t entry) |
533 | { | |
534 | if (*image->entry != 0) | |
535 | image->entry++; | |
536 | ||
537 | if (image->entry == image->last_entry) { | |
538 | kimage_entry_t *ind_page; | |
539 | struct page *page; | |
540 | ||
541 | page = kimage_alloc_page(image, GFP_KERNEL, KIMAGE_NO_DEST); | |
542 | if (!page) | |
543 | return -ENOMEM; | |
544 | ||
545 | ind_page = page_address(page); | |
43546d86 | 546 | *image->entry = virt_to_boot_phys(ind_page) | IND_INDIRECTION; |
2965faa5 DY |
547 | image->entry = ind_page; |
548 | image->last_entry = ind_page + | |
549 | ((PAGE_SIZE/sizeof(kimage_entry_t)) - 1); | |
550 | } | |
551 | *image->entry = entry; | |
552 | image->entry++; | |
553 | *image->entry = 0; | |
554 | ||
555 | return 0; | |
556 | } | |
557 | ||
558 | static int kimage_set_destination(struct kimage *image, | |
559 | unsigned long destination) | |
560 | { | |
561 | int result; | |
562 | ||
563 | destination &= PAGE_MASK; | |
564 | result = kimage_add_entry(image, destination | IND_DESTINATION); | |
565 | ||
566 | return result; | |
567 | } | |
568 | ||
569 | ||
570 | static int kimage_add_page(struct kimage *image, unsigned long page) | |
571 | { | |
572 | int result; | |
573 | ||
574 | page &= PAGE_MASK; | |
575 | result = kimage_add_entry(image, page | IND_SOURCE); | |
576 | ||
577 | return result; | |
578 | } | |
579 | ||
580 | ||
581 | static void kimage_free_extra_pages(struct kimage *image) | |
582 | { | |
583 | /* Walk through and free any extra destination pages I may have */ | |
584 | kimage_free_page_list(&image->dest_pages); | |
585 | ||
586 | /* Walk through and free any unusable pages I have cached */ | |
587 | kimage_free_page_list(&image->unusable_pages); | |
588 | ||
589 | } | |
590 | void kimage_terminate(struct kimage *image) | |
591 | { | |
592 | if (*image->entry != 0) | |
593 | image->entry++; | |
594 | ||
595 | *image->entry = IND_DONE; | |
596 | } | |
597 | ||
598 | #define for_each_kimage_entry(image, ptr, entry) \ | |
599 | for (ptr = &image->head; (entry = *ptr) && !(entry & IND_DONE); \ | |
600 | ptr = (entry & IND_INDIRECTION) ? \ | |
43546d86 | 601 | boot_phys_to_virt((entry & PAGE_MASK)) : ptr + 1) |
2965faa5 DY |
602 | |
603 | static void kimage_free_entry(kimage_entry_t entry) | |
604 | { | |
605 | struct page *page; | |
606 | ||
43546d86 | 607 | page = boot_pfn_to_page(entry >> PAGE_SHIFT); |
2965faa5 DY |
608 | kimage_free_pages(page); |
609 | } | |
610 | ||
611 | void kimage_free(struct kimage *image) | |
612 | { | |
613 | kimage_entry_t *ptr, entry; | |
614 | kimage_entry_t ind = 0; | |
615 | ||
616 | if (!image) | |
617 | return; | |
618 | ||
1229384f XP |
619 | if (image->vmcoreinfo_data_copy) { |
620 | crash_update_vmcoreinfo_safecopy(NULL); | |
621 | vunmap(image->vmcoreinfo_data_copy); | |
622 | } | |
623 | ||
2965faa5 DY |
624 | kimage_free_extra_pages(image); |
625 | for_each_kimage_entry(image, ptr, entry) { | |
626 | if (entry & IND_INDIRECTION) { | |
627 | /* Free the previous indirection page */ | |
628 | if (ind & IND_INDIRECTION) | |
629 | kimage_free_entry(ind); | |
630 | /* Save this indirection page until we are | |
631 | * done with it. | |
632 | */ | |
633 | ind = entry; | |
634 | } else if (entry & IND_SOURCE) | |
635 | kimage_free_entry(entry); | |
636 | } | |
637 | /* Free the final indirection page */ | |
638 | if (ind & IND_INDIRECTION) | |
639 | kimage_free_entry(ind); | |
640 | ||
641 | /* Handle any machine specific cleanup */ | |
642 | machine_kexec_cleanup(image); | |
643 | ||
644 | /* Free the kexec control pages... */ | |
645 | kimage_free_page_list(&image->control_pages); | |
646 | ||
647 | /* | |
648 | * Free up any temporary buffers allocated. This might hit if | |
649 | * error occurred much later after buffer allocation. | |
650 | */ | |
651 | if (image->file_mode) | |
652 | kimage_file_post_load_cleanup(image); | |
653 | ||
654 | kfree(image); | |
655 | } | |
656 | ||
657 | static kimage_entry_t *kimage_dst_used(struct kimage *image, | |
658 | unsigned long page) | |
659 | { | |
660 | kimage_entry_t *ptr, entry; | |
661 | unsigned long destination = 0; | |
662 | ||
663 | for_each_kimage_entry(image, ptr, entry) { | |
664 | if (entry & IND_DESTINATION) | |
665 | destination = entry & PAGE_MASK; | |
666 | else if (entry & IND_SOURCE) { | |
667 | if (page == destination) | |
668 | return ptr; | |
669 | destination += PAGE_SIZE; | |
670 | } | |
671 | } | |
672 | ||
673 | return NULL; | |
674 | } | |
675 | ||
676 | static struct page *kimage_alloc_page(struct kimage *image, | |
677 | gfp_t gfp_mask, | |
678 | unsigned long destination) | |
679 | { | |
680 | /* | |
681 | * Here we implement safeguards to ensure that a source page | |
682 | * is not copied to its destination page before the data on | |
683 | * the destination page is no longer useful. | |
684 | * | |
685 | * To do this we maintain the invariant that a source page is | |
686 | * either its own destination page, or it is not a | |
687 | * destination page at all. | |
688 | * | |
689 | * That is slightly stronger than required, but the proof | |
690 | * that no problems will not occur is trivial, and the | |
691 | * implementation is simply to verify. | |
692 | * | |
693 | * When allocating all pages normally this algorithm will run | |
694 | * in O(N) time, but in the worst case it will run in O(N^2) | |
695 | * time. If the runtime is a problem the data structures can | |
696 | * be fixed. | |
697 | */ | |
698 | struct page *page; | |
699 | unsigned long addr; | |
700 | ||
701 | /* | |
702 | * Walk through the list of destination pages, and see if I | |
703 | * have a match. | |
704 | */ | |
705 | list_for_each_entry(page, &image->dest_pages, lru) { | |
43546d86 | 706 | addr = page_to_boot_pfn(page) << PAGE_SHIFT; |
2965faa5 DY |
707 | if (addr == destination) { |
708 | list_del(&page->lru); | |
709 | return page; | |
710 | } | |
711 | } | |
712 | page = NULL; | |
713 | while (1) { | |
714 | kimage_entry_t *old; | |
715 | ||
716 | /* Allocate a page, if we run out of memory give up */ | |
717 | page = kimage_alloc_pages(gfp_mask, 0); | |
718 | if (!page) | |
719 | return NULL; | |
720 | /* If the page cannot be used file it away */ | |
43546d86 | 721 | if (page_to_boot_pfn(page) > |
2965faa5 DY |
722 | (KEXEC_SOURCE_MEMORY_LIMIT >> PAGE_SHIFT)) { |
723 | list_add(&page->lru, &image->unusable_pages); | |
724 | continue; | |
725 | } | |
43546d86 | 726 | addr = page_to_boot_pfn(page) << PAGE_SHIFT; |
2965faa5 DY |
727 | |
728 | /* If it is the destination page we want use it */ | |
729 | if (addr == destination) | |
730 | break; | |
731 | ||
732 | /* If the page is not a destination page use it */ | |
733 | if (!kimage_is_destination_range(image, addr, | |
734 | addr + PAGE_SIZE)) | |
735 | break; | |
736 | ||
737 | /* | |
738 | * I know that the page is someones destination page. | |
739 | * See if there is already a source page for this | |
740 | * destination page. And if so swap the source pages. | |
741 | */ | |
742 | old = kimage_dst_used(image, addr); | |
743 | if (old) { | |
744 | /* If so move it */ | |
745 | unsigned long old_addr; | |
746 | struct page *old_page; | |
747 | ||
748 | old_addr = *old & PAGE_MASK; | |
43546d86 | 749 | old_page = boot_pfn_to_page(old_addr >> PAGE_SHIFT); |
2965faa5 DY |
750 | copy_highpage(page, old_page); |
751 | *old = addr | (*old & ~PAGE_MASK); | |
752 | ||
753 | /* The old page I have found cannot be a | |
754 | * destination page, so return it if it's | |
755 | * gfp_flags honor the ones passed in. | |
756 | */ | |
757 | if (!(gfp_mask & __GFP_HIGHMEM) && | |
758 | PageHighMem(old_page)) { | |
759 | kimage_free_pages(old_page); | |
760 | continue; | |
761 | } | |
762 | addr = old_addr; | |
763 | page = old_page; | |
764 | break; | |
765 | } | |
766 | /* Place the page on the destination list, to be used later */ | |
767 | list_add(&page->lru, &image->dest_pages); | |
768 | } | |
769 | ||
770 | return page; | |
771 | } | |
772 | ||
773 | static int kimage_load_normal_segment(struct kimage *image, | |
774 | struct kexec_segment *segment) | |
775 | { | |
776 | unsigned long maddr; | |
777 | size_t ubytes, mbytes; | |
778 | int result; | |
779 | unsigned char __user *buf = NULL; | |
780 | unsigned char *kbuf = NULL; | |
781 | ||
782 | result = 0; | |
783 | if (image->file_mode) | |
784 | kbuf = segment->kbuf; | |
785 | else | |
786 | buf = segment->buf; | |
787 | ubytes = segment->bufsz; | |
788 | mbytes = segment->memsz; | |
789 | maddr = segment->mem; | |
790 | ||
791 | result = kimage_set_destination(image, maddr); | |
792 | if (result < 0) | |
793 | goto out; | |
794 | ||
795 | while (mbytes) { | |
796 | struct page *page; | |
797 | char *ptr; | |
798 | size_t uchunk, mchunk; | |
799 | ||
800 | page = kimage_alloc_page(image, GFP_HIGHUSER, maddr); | |
801 | if (!page) { | |
802 | result = -ENOMEM; | |
803 | goto out; | |
804 | } | |
43546d86 | 805 | result = kimage_add_page(image, page_to_boot_pfn(page) |
2965faa5 DY |
806 | << PAGE_SHIFT); |
807 | if (result < 0) | |
808 | goto out; | |
809 | ||
810 | ptr = kmap(page); | |
811 | /* Start with a clear page */ | |
812 | clear_page(ptr); | |
813 | ptr += maddr & ~PAGE_MASK; | |
814 | mchunk = min_t(size_t, mbytes, | |
815 | PAGE_SIZE - (maddr & ~PAGE_MASK)); | |
816 | uchunk = min(ubytes, mchunk); | |
817 | ||
818 | /* For file based kexec, source pages are in kernel memory */ | |
819 | if (image->file_mode) | |
820 | memcpy(ptr, kbuf, uchunk); | |
821 | else | |
822 | result = copy_from_user(ptr, buf, uchunk); | |
823 | kunmap(page); | |
824 | if (result) { | |
825 | result = -EFAULT; | |
826 | goto out; | |
827 | } | |
828 | ubytes -= uchunk; | |
829 | maddr += mchunk; | |
830 | if (image->file_mode) | |
831 | kbuf += mchunk; | |
832 | else | |
833 | buf += mchunk; | |
834 | mbytes -= mchunk; | |
a8311f64 JF |
835 | |
836 | cond_resched(); | |
2965faa5 DY |
837 | } |
838 | out: | |
839 | return result; | |
840 | } | |
841 | ||
842 | static int kimage_load_crash_segment(struct kimage *image, | |
843 | struct kexec_segment *segment) | |
844 | { | |
845 | /* For crash dumps kernels we simply copy the data from | |
846 | * user space to it's destination. | |
847 | * We do things a page at a time for the sake of kmap. | |
848 | */ | |
849 | unsigned long maddr; | |
850 | size_t ubytes, mbytes; | |
851 | int result; | |
852 | unsigned char __user *buf = NULL; | |
853 | unsigned char *kbuf = NULL; | |
854 | ||
855 | result = 0; | |
856 | if (image->file_mode) | |
857 | kbuf = segment->kbuf; | |
858 | else | |
859 | buf = segment->buf; | |
860 | ubytes = segment->bufsz; | |
861 | mbytes = segment->memsz; | |
862 | maddr = segment->mem; | |
863 | while (mbytes) { | |
864 | struct page *page; | |
865 | char *ptr; | |
866 | size_t uchunk, mchunk; | |
867 | ||
43546d86 | 868 | page = boot_pfn_to_page(maddr >> PAGE_SHIFT); |
2965faa5 DY |
869 | if (!page) { |
870 | result = -ENOMEM; | |
871 | goto out; | |
872 | } | |
9cf38d55 | 873 | arch_kexec_post_alloc_pages(page_address(page), 1, 0); |
2965faa5 DY |
874 | ptr = kmap(page); |
875 | ptr += maddr & ~PAGE_MASK; | |
876 | mchunk = min_t(size_t, mbytes, | |
877 | PAGE_SIZE - (maddr & ~PAGE_MASK)); | |
878 | uchunk = min(ubytes, mchunk); | |
879 | if (mchunk > uchunk) { | |
880 | /* Zero the trailing part of the page */ | |
881 | memset(ptr + uchunk, 0, mchunk - uchunk); | |
882 | } | |
883 | ||
884 | /* For file based kexec, source pages are in kernel memory */ | |
885 | if (image->file_mode) | |
886 | memcpy(ptr, kbuf, uchunk); | |
887 | else | |
888 | result = copy_from_user(ptr, buf, uchunk); | |
889 | kexec_flush_icache_page(page); | |
890 | kunmap(page); | |
9cf38d55 | 891 | arch_kexec_pre_free_pages(page_address(page), 1); |
2965faa5 DY |
892 | if (result) { |
893 | result = -EFAULT; | |
894 | goto out; | |
895 | } | |
896 | ubytes -= uchunk; | |
897 | maddr += mchunk; | |
898 | if (image->file_mode) | |
899 | kbuf += mchunk; | |
900 | else | |
901 | buf += mchunk; | |
902 | mbytes -= mchunk; | |
a8311f64 JF |
903 | |
904 | cond_resched(); | |
2965faa5 DY |
905 | } |
906 | out: | |
907 | return result; | |
908 | } | |
909 | ||
910 | int kimage_load_segment(struct kimage *image, | |
911 | struct kexec_segment *segment) | |
912 | { | |
913 | int result = -ENOMEM; | |
914 | ||
915 | switch (image->type) { | |
916 | case KEXEC_TYPE_DEFAULT: | |
917 | result = kimage_load_normal_segment(image, segment); | |
918 | break; | |
919 | case KEXEC_TYPE_CRASH: | |
920 | result = kimage_load_crash_segment(image, segment); | |
921 | break; | |
922 | } | |
923 | ||
924 | return result; | |
925 | } | |
926 | ||
927 | struct kimage *kexec_image; | |
928 | struct kimage *kexec_crash_image; | |
929 | int kexec_load_disabled; | |
930 | ||
7bbee5ca HK |
931 | /* |
932 | * No panic_cpu check version of crash_kexec(). This function is called | |
933 | * only when panic_cpu holds the current CPU number; this is the only CPU | |
934 | * which processes crash_kexec routines. | |
935 | */ | |
c207aee4 | 936 | void __noclone __crash_kexec(struct pt_regs *regs) |
2965faa5 DY |
937 | { |
938 | /* Take the kexec_mutex here to prevent sys_kexec_load | |
939 | * running on one cpu from replacing the crash kernel | |
940 | * we are using after a panic on a different cpu. | |
941 | * | |
942 | * If the crash kernel was not located in a fixed area | |
943 | * of memory the xchg(&kexec_crash_image) would be | |
944 | * sufficient. But since I reuse the memory... | |
945 | */ | |
946 | if (mutex_trylock(&kexec_mutex)) { | |
947 | if (kexec_crash_image) { | |
948 | struct pt_regs fixed_regs; | |
949 | ||
950 | crash_setup_regs(&fixed_regs, regs); | |
951 | crash_save_vmcoreinfo(); | |
952 | machine_crash_shutdown(&fixed_regs); | |
953 | machine_kexec(kexec_crash_image); | |
954 | } | |
955 | mutex_unlock(&kexec_mutex); | |
956 | } | |
957 | } | |
c207aee4 | 958 | STACK_FRAME_NON_STANDARD(__crash_kexec); |
2965faa5 | 959 | |
7bbee5ca HK |
960 | void crash_kexec(struct pt_regs *regs) |
961 | { | |
962 | int old_cpu, this_cpu; | |
963 | ||
964 | /* | |
965 | * Only one CPU is allowed to execute the crash_kexec() code as with | |
966 | * panic(). Otherwise parallel calls of panic() and crash_kexec() | |
967 | * may stop each other. To exclude them, we use panic_cpu here too. | |
968 | */ | |
969 | this_cpu = raw_smp_processor_id(); | |
970 | old_cpu = atomic_cmpxchg(&panic_cpu, PANIC_CPU_INVALID, this_cpu); | |
971 | if (old_cpu == PANIC_CPU_INVALID) { | |
972 | /* This is the 1st CPU which comes here, so go ahead. */ | |
f92bac3b | 973 | printk_safe_flush_on_panic(); |
7bbee5ca HK |
974 | __crash_kexec(regs); |
975 | ||
976 | /* | |
977 | * Reset panic_cpu to allow another panic()/crash_kexec() | |
978 | * call. | |
979 | */ | |
980 | atomic_set(&panic_cpu, PANIC_CPU_INVALID); | |
981 | } | |
982 | } | |
983 | ||
2965faa5 DY |
984 | size_t crash_get_memory_size(void) |
985 | { | |
986 | size_t size = 0; | |
987 | ||
988 | mutex_lock(&kexec_mutex); | |
989 | if (crashk_res.end != crashk_res.start) | |
990 | size = resource_size(&crashk_res); | |
991 | mutex_unlock(&kexec_mutex); | |
992 | return size; | |
993 | } | |
994 | ||
995 | void __weak crash_free_reserved_phys_range(unsigned long begin, | |
996 | unsigned long end) | |
997 | { | |
998 | unsigned long addr; | |
999 | ||
1000 | for (addr = begin; addr < end; addr += PAGE_SIZE) | |
43546d86 | 1001 | free_reserved_page(boot_pfn_to_page(addr >> PAGE_SHIFT)); |
2965faa5 DY |
1002 | } |
1003 | ||
1004 | int crash_shrink_memory(unsigned long new_size) | |
1005 | { | |
1006 | int ret = 0; | |
1007 | unsigned long start, end; | |
1008 | unsigned long old_size; | |
1009 | struct resource *ram_res; | |
1010 | ||
1011 | mutex_lock(&kexec_mutex); | |
1012 | ||
1013 | if (kexec_crash_image) { | |
1014 | ret = -ENOENT; | |
1015 | goto unlock; | |
1016 | } | |
1017 | start = crashk_res.start; | |
1018 | end = crashk_res.end; | |
1019 | old_size = (end == 0) ? 0 : end - start + 1; | |
1020 | if (new_size >= old_size) { | |
1021 | ret = (new_size == old_size) ? 0 : -EINVAL; | |
1022 | goto unlock; | |
1023 | } | |
1024 | ||
1025 | ram_res = kzalloc(sizeof(*ram_res), GFP_KERNEL); | |
1026 | if (!ram_res) { | |
1027 | ret = -ENOMEM; | |
1028 | goto unlock; | |
1029 | } | |
1030 | ||
1031 | start = roundup(start, KEXEC_CRASH_MEM_ALIGN); | |
1032 | end = roundup(start + new_size, KEXEC_CRASH_MEM_ALIGN); | |
1033 | ||
2965faa5 DY |
1034 | crash_free_reserved_phys_range(end, crashk_res.end); |
1035 | ||
1036 | if ((start == end) && (crashk_res.parent != NULL)) | |
1037 | release_resource(&crashk_res); | |
1038 | ||
1039 | ram_res->start = end; | |
1040 | ram_res->end = crashk_res.end; | |
1a085d07 | 1041 | ram_res->flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM; |
2965faa5 DY |
1042 | ram_res->name = "System RAM"; |
1043 | ||
1044 | crashk_res.end = end - 1; | |
1045 | ||
1046 | insert_resource(&iomem_resource, ram_res); | |
2965faa5 DY |
1047 | |
1048 | unlock: | |
1049 | mutex_unlock(&kexec_mutex); | |
1050 | return ret; | |
1051 | } | |
1052 | ||
2965faa5 DY |
1053 | void crash_save_cpu(struct pt_regs *regs, int cpu) |
1054 | { | |
1055 | struct elf_prstatus prstatus; | |
1056 | u32 *buf; | |
1057 | ||
1058 | if ((cpu < 0) || (cpu >= nr_cpu_ids)) | |
1059 | return; | |
1060 | ||
1061 | /* Using ELF notes here is opportunistic. | |
1062 | * I need a well defined structure format | |
1063 | * for the data I pass, and I need tags | |
1064 | * on the data to indicate what information I have | |
1065 | * squirrelled away. ELF notes happen to provide | |
1066 | * all of that, so there is no need to invent something new. | |
1067 | */ | |
1068 | buf = (u32 *)per_cpu_ptr(crash_notes, cpu); | |
1069 | if (!buf) | |
1070 | return; | |
1071 | memset(&prstatus, 0, sizeof(prstatus)); | |
1072 | prstatus.pr_pid = current->pid; | |
1073 | elf_core_copy_kernel_regs(&prstatus.pr_reg, regs); | |
1074 | buf = append_elf_note(buf, KEXEC_CORE_NOTE_NAME, NT_PRSTATUS, | |
1075 | &prstatus, sizeof(prstatus)); | |
1076 | final_note(buf); | |
1077 | } | |
1078 | ||
1079 | static int __init crash_notes_memory_init(void) | |
1080 | { | |
1081 | /* Allocate memory for saving cpu registers. */ | |
bbb78b8f BH |
1082 | size_t size, align; |
1083 | ||
1084 | /* | |
1085 | * crash_notes could be allocated across 2 vmalloc pages when percpu | |
1086 | * is vmalloc based . vmalloc doesn't guarantee 2 continuous vmalloc | |
1087 | * pages are also on 2 continuous physical pages. In this case the | |
1088 | * 2nd part of crash_notes in 2nd page could be lost since only the | |
1089 | * starting address and size of crash_notes are exported through sysfs. | |
1090 | * Here round up the size of crash_notes to the nearest power of two | |
1091 | * and pass it to __alloc_percpu as align value. This can make sure | |
1092 | * crash_notes is allocated inside one physical page. | |
1093 | */ | |
1094 | size = sizeof(note_buf_t); | |
1095 | align = min(roundup_pow_of_two(sizeof(note_buf_t)), PAGE_SIZE); | |
1096 | ||
1097 | /* | |
1098 | * Break compile if size is bigger than PAGE_SIZE since crash_notes | |
1099 | * definitely will be in 2 pages with that. | |
1100 | */ | |
1101 | BUILD_BUG_ON(size > PAGE_SIZE); | |
1102 | ||
1103 | crash_notes = __alloc_percpu(size, align); | |
2965faa5 | 1104 | if (!crash_notes) { |
de90a6bc | 1105 | pr_warn("Memory allocation for saving cpu register states failed\n"); |
2965faa5 DY |
1106 | return -ENOMEM; |
1107 | } | |
1108 | return 0; | |
1109 | } | |
1110 | subsys_initcall(crash_notes_memory_init); | |
1111 | ||
1112 | ||
2965faa5 DY |
1113 | /* |
1114 | * Move into place and start executing a preloaded standalone | |
1115 | * executable. If nothing was preloaded return an error. | |
1116 | */ | |
1117 | int kernel_kexec(void) | |
1118 | { | |
1119 | int error = 0; | |
1120 | ||
1121 | if (!mutex_trylock(&kexec_mutex)) | |
1122 | return -EBUSY; | |
1123 | if (!kexec_image) { | |
1124 | error = -EINVAL; | |
1125 | goto Unlock; | |
1126 | } | |
1127 | ||
1128 | #ifdef CONFIG_KEXEC_JUMP | |
1129 | if (kexec_image->preserve_context) { | |
1130 | lock_system_sleep(); | |
1131 | pm_prepare_console(); | |
1132 | error = freeze_processes(); | |
1133 | if (error) { | |
1134 | error = -EBUSY; | |
1135 | goto Restore_console; | |
1136 | } | |
1137 | suspend_console(); | |
1138 | error = dpm_suspend_start(PMSG_FREEZE); | |
1139 | if (error) | |
1140 | goto Resume_console; | |
1141 | /* At this point, dpm_suspend_start() has been called, | |
1142 | * but *not* dpm_suspend_end(). We *must* call | |
1143 | * dpm_suspend_end() now. Otherwise, drivers for | |
1144 | * some devices (e.g. interrupt controllers) become | |
1145 | * desynchronized with the actual state of the | |
1146 | * hardware at resume time, and evil weirdness ensues. | |
1147 | */ | |
1148 | error = dpm_suspend_end(PMSG_FREEZE); | |
1149 | if (error) | |
1150 | goto Resume_devices; | |
2f1a6fbb | 1151 | error = suspend_disable_secondary_cpus(); |
2965faa5 DY |
1152 | if (error) |
1153 | goto Enable_cpus; | |
1154 | local_irq_disable(); | |
1155 | error = syscore_suspend(); | |
1156 | if (error) | |
1157 | goto Enable_irqs; | |
1158 | } else | |
1159 | #endif | |
1160 | { | |
1161 | kexec_in_progress = true; | |
1162 | kernel_restart_prepare(NULL); | |
1163 | migrate_to_reboot_cpu(); | |
1164 | ||
1165 | /* | |
1166 | * migrate_to_reboot_cpu() disables CPU hotplug assuming that | |
1167 | * no further code needs to use CPU hotplug (which is true in | |
1168 | * the reboot case). However, the kexec path depends on using | |
1169 | * CPU hotplug again; so re-enable it here. | |
1170 | */ | |
1171 | cpu_hotplug_enable(); | |
1172 | pr_emerg("Starting new kernel\n"); | |
1173 | machine_shutdown(); | |
1174 | } | |
1175 | ||
1176 | machine_kexec(kexec_image); | |
1177 | ||
1178 | #ifdef CONFIG_KEXEC_JUMP | |
1179 | if (kexec_image->preserve_context) { | |
1180 | syscore_resume(); | |
1181 | Enable_irqs: | |
1182 | local_irq_enable(); | |
1183 | Enable_cpus: | |
2f1a6fbb | 1184 | suspend_enable_secondary_cpus(); |
2965faa5 DY |
1185 | dpm_resume_start(PMSG_RESTORE); |
1186 | Resume_devices: | |
1187 | dpm_resume_end(PMSG_RESTORE); | |
1188 | Resume_console: | |
1189 | resume_console(); | |
1190 | thaw_processes(); | |
1191 | Restore_console: | |
1192 | pm_restore_console(); | |
1193 | unlock_system_sleep(); | |
1194 | } | |
1195 | #endif | |
1196 | ||
1197 | Unlock: | |
1198 | mutex_unlock(&kexec_mutex); | |
1199 | return error; | |
1200 | } | |
1201 | ||
1202 | /* | |
7a0058ec XP |
1203 | * Protection mechanism for crashkernel reserved memory after |
1204 | * the kdump kernel is loaded. | |
2965faa5 DY |
1205 | * |
1206 | * Provide an empty default implementation here -- architecture | |
1207 | * code may override this | |
1208 | */ | |
9b492cf5 XP |
1209 | void __weak arch_kexec_protect_crashkres(void) |
1210 | {} | |
1211 | ||
1212 | void __weak arch_kexec_unprotect_crashkres(void) | |
1213 | {} |