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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 | 8 | |
400031e0 | 9 | #include <linux/btf.h> |
2965faa5 DY |
10 | #include <linux/capability.h> |
11 | #include <linux/mm.h> | |
12 | #include <linux/file.h> | |
13 | #include <linux/slab.h> | |
14 | #include <linux/fs.h> | |
15 | #include <linux/kexec.h> | |
16 | #include <linux/mutex.h> | |
17 | #include <linux/list.h> | |
18 | #include <linux/highmem.h> | |
19 | #include <linux/syscalls.h> | |
20 | #include <linux/reboot.h> | |
21 | #include <linux/ioport.h> | |
22 | #include <linux/hardirq.h> | |
23 | #include <linux/elf.h> | |
24 | #include <linux/elfcore.h> | |
25 | #include <linux/utsname.h> | |
26 | #include <linux/numa.h> | |
27 | #include <linux/suspend.h> | |
28 | #include <linux/device.h> | |
29 | #include <linux/freezer.h> | |
f39650de | 30 | #include <linux/panic_notifier.h> |
2965faa5 DY |
31 | #include <linux/pm.h> |
32 | #include <linux/cpu.h> | |
33 | #include <linux/uaccess.h> | |
34 | #include <linux/io.h> | |
35 | #include <linux/console.h> | |
36 | #include <linux/vmalloc.h> | |
37 | #include <linux/swap.h> | |
38 | #include <linux/syscore_ops.h> | |
39 | #include <linux/compiler.h> | |
40 | #include <linux/hugetlb.h> | |
00089c04 | 41 | #include <linux/objtool.h> |
b2075dbb | 42 | #include <linux/kmsg_dump.h> |
2965faa5 DY |
43 | |
44 | #include <asm/page.h> | |
45 | #include <asm/sections.h> | |
46 | ||
47 | #include <crypto/hash.h> | |
2965faa5 DY |
48 | #include "kexec_internal.h" |
49 | ||
05c62574 | 50 | atomic_t __kexec_lock = ATOMIC_INIT(0); |
2965faa5 | 51 | |
2965faa5 DY |
52 | /* Flag to indicate we are going to kexec a new kernel */ |
53 | bool kexec_in_progress = false; | |
54 | ||
cbc2fe9d BH |
55 | bool kexec_file_dbg_print; |
56 | ||
2965faa5 DY |
57 | int kexec_should_crash(struct task_struct *p) |
58 | { | |
59 | /* | |
60 | * If crash_kexec_post_notifiers is enabled, don't run | |
61 | * crash_kexec() here yet, which must be run after panic | |
62 | * notifiers in panic(). | |
63 | */ | |
64 | if (crash_kexec_post_notifiers) | |
65 | return 0; | |
66 | /* | |
05ea0424 | 67 | * There are 4 panic() calls in make_task_dead() path, each of which |
2965faa5 DY |
68 | * corresponds to each of these 4 conditions. |
69 | */ | |
70 | if (in_interrupt() || !p->pid || is_global_init(p) || panic_on_oops) | |
71 | return 1; | |
72 | return 0; | |
73 | } | |
74 | ||
21db79e8 PT |
75 | int kexec_crash_loaded(void) |
76 | { | |
77 | return !!kexec_crash_image; | |
78 | } | |
79 | EXPORT_SYMBOL_GPL(kexec_crash_loaded); | |
80 | ||
2965faa5 DY |
81 | /* |
82 | * When kexec transitions to the new kernel there is a one-to-one | |
83 | * mapping between physical and virtual addresses. On processors | |
84 | * where you can disable the MMU this is trivial, and easy. For | |
85 | * others it is still a simple predictable page table to setup. | |
86 | * | |
87 | * In that environment kexec copies the new kernel to its final | |
88 | * resting place. This means I can only support memory whose | |
89 | * physical address can fit in an unsigned long. In particular | |
90 | * addresses where (pfn << PAGE_SHIFT) > ULONG_MAX cannot be handled. | |
91 | * If the assembly stub has more restrictive requirements | |
92 | * KEXEC_SOURCE_MEMORY_LIMIT and KEXEC_DEST_MEMORY_LIMIT can be | |
93 | * defined more restrictively in <asm/kexec.h>. | |
94 | * | |
95 | * The code for the transition from the current kernel to the | |
7b7b8a2c | 96 | * new kernel is placed in the control_code_buffer, whose size |
2965faa5 DY |
97 | * is given by KEXEC_CONTROL_PAGE_SIZE. In the best case only a single |
98 | * page of memory is necessary, but some architectures require more. | |
99 | * Because this memory must be identity mapped in the transition from | |
100 | * virtual to physical addresses it must live in the range | |
101 | * 0 - TASK_SIZE, as only the user space mappings are arbitrarily | |
102 | * modifiable. | |
103 | * | |
104 | * The assembly stub in the control code buffer is passed a linked list | |
105 | * of descriptor pages detailing the source pages of the new kernel, | |
106 | * and the destination addresses of those source pages. As this data | |
107 | * structure is not used in the context of the current OS, it must | |
108 | * be self-contained. | |
109 | * | |
110 | * The code has been made to work with highmem pages and will use a | |
111 | * destination page in its final resting place (if it happens | |
112 | * to allocate it). The end product of this is that most of the | |
113 | * physical address space, and most of RAM can be used. | |
114 | * | |
115 | * Future directions include: | |
116 | * - allocating a page table with the control code buffer identity | |
117 | * mapped, to simplify machine_kexec and make kexec_on_panic more | |
118 | * reliable. | |
119 | */ | |
120 | ||
121 | /* | |
122 | * KIMAGE_NO_DEST is an impossible destination address..., for | |
123 | * allocating pages whose destination address we do not care about. | |
124 | */ | |
125 | #define KIMAGE_NO_DEST (-1UL) | |
1730f146 | 126 | #define PAGE_COUNT(x) (((x) + PAGE_SIZE - 1) >> PAGE_SHIFT) |
2965faa5 DY |
127 | |
128 | static struct page *kimage_alloc_page(struct kimage *image, | |
129 | gfp_t gfp_mask, | |
130 | unsigned long dest); | |
131 | ||
132 | int sanity_check_segment_list(struct kimage *image) | |
133 | { | |
4caf9615 | 134 | int i; |
2965faa5 | 135 | unsigned long nr_segments = image->nr_segments; |
1730f146 | 136 | unsigned long total_pages = 0; |
ca79b0c2 | 137 | unsigned long nr_pages = totalram_pages(); |
2965faa5 DY |
138 | |
139 | /* | |
140 | * Verify we have good destination addresses. The caller is | |
141 | * responsible for making certain we don't attempt to load | |
142 | * the new image into invalid or reserved areas of RAM. This | |
143 | * just verifies it is an address we can use. | |
144 | * | |
145 | * Since the kernel does everything in page size chunks ensure | |
146 | * the destination addresses are page aligned. Too many | |
147 | * special cases crop of when we don't do this. The most | |
148 | * insidious is getting overlapping destination addresses | |
149 | * simply because addresses are changed to page size | |
150 | * granularity. | |
151 | */ | |
2965faa5 DY |
152 | for (i = 0; i < nr_segments; i++) { |
153 | unsigned long mstart, mend; | |
154 | ||
155 | mstart = image->segment[i].mem; | |
156 | mend = mstart + image->segment[i].memsz; | |
465d3777 RK |
157 | if (mstart > mend) |
158 | return -EADDRNOTAVAIL; | |
2965faa5 | 159 | if ((mstart & ~PAGE_MASK) || (mend & ~PAGE_MASK)) |
4caf9615 | 160 | return -EADDRNOTAVAIL; |
2965faa5 | 161 | if (mend >= KEXEC_DESTINATION_MEMORY_LIMIT) |
4caf9615 | 162 | return -EADDRNOTAVAIL; |
2965faa5 DY |
163 | } |
164 | ||
165 | /* Verify our destination addresses do not overlap. | |
166 | * If we alloed overlapping destination addresses | |
167 | * through very weird things can happen with no | |
168 | * easy explanation as one segment stops on another. | |
169 | */ | |
2965faa5 DY |
170 | for (i = 0; i < nr_segments; i++) { |
171 | unsigned long mstart, mend; | |
172 | unsigned long j; | |
173 | ||
174 | mstart = image->segment[i].mem; | |
175 | mend = mstart + image->segment[i].memsz; | |
176 | for (j = 0; j < i; j++) { | |
177 | unsigned long pstart, pend; | |
178 | ||
179 | pstart = image->segment[j].mem; | |
180 | pend = pstart + image->segment[j].memsz; | |
181 | /* Do the segments overlap ? */ | |
182 | if ((mend > pstart) && (mstart < pend)) | |
4caf9615 | 183 | return -EINVAL; |
2965faa5 DY |
184 | } |
185 | } | |
186 | ||
187 | /* Ensure our buffer sizes are strictly less than | |
188 | * our memory sizes. This should always be the case, | |
189 | * and it is easier to check up front than to be surprised | |
190 | * later on. | |
191 | */ | |
2965faa5 DY |
192 | for (i = 0; i < nr_segments; i++) { |
193 | if (image->segment[i].bufsz > image->segment[i].memsz) | |
4caf9615 | 194 | return -EINVAL; |
2965faa5 DY |
195 | } |
196 | ||
1730f146 | 197 | /* |
198 | * Verify that no more than half of memory will be consumed. If the | |
199 | * request from userspace is too large, a large amount of time will be | |
200 | * wasted allocating pages, which can cause a soft lockup. | |
201 | */ | |
202 | for (i = 0; i < nr_segments; i++) { | |
3d6357de | 203 | if (PAGE_COUNT(image->segment[i].memsz) > nr_pages / 2) |
1730f146 | 204 | return -EINVAL; |
205 | ||
206 | total_pages += PAGE_COUNT(image->segment[i].memsz); | |
207 | } | |
208 | ||
3d6357de | 209 | if (total_pages > nr_pages / 2) |
1730f146 | 210 | return -EINVAL; |
211 | ||
2965faa5 DY |
212 | /* |
213 | * Verify we have good destination addresses. Normally | |
214 | * the caller is responsible for making certain we don't | |
215 | * attempt to load the new image into invalid or reserved | |
216 | * areas of RAM. But crash kernels are preloaded into a | |
217 | * reserved area of ram. We must ensure the addresses | |
218 | * are in the reserved area otherwise preloading the | |
219 | * kernel could corrupt things. | |
220 | */ | |
221 | ||
222 | if (image->type == KEXEC_TYPE_CRASH) { | |
2965faa5 DY |
223 | for (i = 0; i < nr_segments; i++) { |
224 | unsigned long mstart, mend; | |
225 | ||
226 | mstart = image->segment[i].mem; | |
227 | mend = mstart + image->segment[i].memsz - 1; | |
228 | /* Ensure we are within the crash kernel limits */ | |
43546d86 RK |
229 | if ((mstart < phys_to_boot_phys(crashk_res.start)) || |
230 | (mend > phys_to_boot_phys(crashk_res.end))) | |
4caf9615 | 231 | return -EADDRNOTAVAIL; |
2965faa5 DY |
232 | } |
233 | } | |
234 | ||
235 | return 0; | |
236 | } | |
237 | ||
238 | struct kimage *do_kimage_alloc_init(void) | |
239 | { | |
240 | struct kimage *image; | |
241 | ||
242 | /* Allocate a controlling structure */ | |
243 | image = kzalloc(sizeof(*image), GFP_KERNEL); | |
244 | if (!image) | |
245 | return NULL; | |
246 | ||
247 | image->head = 0; | |
248 | image->entry = &image->head; | |
249 | image->last_entry = &image->head; | |
250 | image->control_page = ~0; /* By default this does not apply */ | |
251 | image->type = KEXEC_TYPE_DEFAULT; | |
252 | ||
253 | /* Initialize the list of control pages */ | |
254 | INIT_LIST_HEAD(&image->control_pages); | |
255 | ||
256 | /* Initialize the list of destination pages */ | |
257 | INIT_LIST_HEAD(&image->dest_pages); | |
258 | ||
259 | /* Initialize the list of unusable pages */ | |
260 | INIT_LIST_HEAD(&image->unusable_pages); | |
261 | ||
24726275 ED |
262 | #ifdef CONFIG_CRASH_HOTPLUG |
263 | image->hp_action = KEXEC_CRASH_HP_NONE; | |
264 | image->elfcorehdr_index = -1; | |
265 | image->elfcorehdr_updated = false; | |
266 | #endif | |
267 | ||
2965faa5 DY |
268 | return image; |
269 | } | |
270 | ||
271 | int kimage_is_destination_range(struct kimage *image, | |
272 | unsigned long start, | |
273 | unsigned long end) | |
274 | { | |
275 | unsigned long i; | |
276 | ||
277 | for (i = 0; i < image->nr_segments; i++) { | |
278 | unsigned long mstart, mend; | |
279 | ||
280 | mstart = image->segment[i].mem; | |
816d334a YW |
281 | mend = mstart + image->segment[i].memsz - 1; |
282 | if ((end >= mstart) && (start <= mend)) | |
2965faa5 DY |
283 | return 1; |
284 | } | |
285 | ||
286 | return 0; | |
287 | } | |
288 | ||
289 | static struct page *kimage_alloc_pages(gfp_t gfp_mask, unsigned int order) | |
290 | { | |
291 | struct page *pages; | |
292 | ||
7c3a6aed TH |
293 | if (fatal_signal_pending(current)) |
294 | return NULL; | |
bba4ed01 | 295 | pages = alloc_pages(gfp_mask & ~__GFP_ZERO, order); |
2965faa5 DY |
296 | if (pages) { |
297 | unsigned int count, i; | |
298 | ||
299 | pages->mapping = NULL; | |
300 | set_page_private(pages, order); | |
301 | count = 1 << order; | |
302 | for (i = 0; i < count; i++) | |
303 | SetPageReserved(pages + i); | |
bba4ed01 TL |
304 | |
305 | arch_kexec_post_alloc_pages(page_address(pages), count, | |
306 | gfp_mask); | |
307 | ||
308 | if (gfp_mask & __GFP_ZERO) | |
309 | for (i = 0; i < count; i++) | |
310 | clear_highpage(pages + i); | |
2965faa5 DY |
311 | } |
312 | ||
313 | return pages; | |
314 | } | |
315 | ||
316 | static void kimage_free_pages(struct page *page) | |
317 | { | |
318 | unsigned int order, count, i; | |
319 | ||
320 | order = page_private(page); | |
321 | count = 1 << order; | |
bba4ed01 TL |
322 | |
323 | arch_kexec_pre_free_pages(page_address(page), count); | |
324 | ||
2965faa5 DY |
325 | for (i = 0; i < count; i++) |
326 | ClearPageReserved(page + i); | |
327 | __free_pages(page, order); | |
328 | } | |
329 | ||
330 | void kimage_free_page_list(struct list_head *list) | |
331 | { | |
2b24692b | 332 | struct page *page, *next; |
2965faa5 | 333 | |
2b24692b | 334 | list_for_each_entry_safe(page, next, list, lru) { |
2965faa5 DY |
335 | list_del(&page->lru); |
336 | kimage_free_pages(page); | |
337 | } | |
338 | } | |
339 | ||
340 | static struct page *kimage_alloc_normal_control_pages(struct kimage *image, | |
341 | unsigned int order) | |
342 | { | |
343 | /* Control pages are special, they are the intermediaries | |
344 | * that are needed while we copy the rest of the pages | |
345 | * to their final resting place. As such they must | |
346 | * not conflict with either the destination addresses | |
347 | * or memory the kernel is already using. | |
348 | * | |
349 | * The only case where we really need more than one of | |
350 | * these are for architectures where we cannot disable | |
351 | * the MMU and must instead generate an identity mapped | |
352 | * page table for all of the memory. | |
353 | * | |
354 | * At worst this runs in O(N) of the image size. | |
355 | */ | |
356 | struct list_head extra_pages; | |
357 | struct page *pages; | |
358 | unsigned int count; | |
359 | ||
360 | count = 1 << order; | |
361 | INIT_LIST_HEAD(&extra_pages); | |
362 | ||
363 | /* Loop while I can allocate a page and the page allocated | |
364 | * is a destination page. | |
365 | */ | |
366 | do { | |
367 | unsigned long pfn, epfn, addr, eaddr; | |
368 | ||
369 | pages = kimage_alloc_pages(KEXEC_CONTROL_MEMORY_GFP, order); | |
370 | if (!pages) | |
371 | break; | |
43546d86 | 372 | pfn = page_to_boot_pfn(pages); |
2965faa5 DY |
373 | epfn = pfn + count; |
374 | addr = pfn << PAGE_SHIFT; | |
816d334a | 375 | eaddr = (epfn << PAGE_SHIFT) - 1; |
2965faa5 DY |
376 | if ((epfn >= (KEXEC_CONTROL_MEMORY_LIMIT >> PAGE_SHIFT)) || |
377 | kimage_is_destination_range(image, addr, eaddr)) { | |
378 | list_add(&pages->lru, &extra_pages); | |
379 | pages = NULL; | |
380 | } | |
381 | } while (!pages); | |
382 | ||
383 | if (pages) { | |
384 | /* Remember the allocated page... */ | |
385 | list_add(&pages->lru, &image->control_pages); | |
386 | ||
387 | /* Because the page is already in it's destination | |
388 | * location we will never allocate another page at | |
389 | * that address. Therefore kimage_alloc_pages | |
390 | * will not return it (again) and we don't need | |
391 | * to give it an entry in image->segment[]. | |
392 | */ | |
393 | } | |
394 | /* Deal with the destination pages I have inadvertently allocated. | |
395 | * | |
396 | * Ideally I would convert multi-page allocations into single | |
397 | * page allocations, and add everything to image->dest_pages. | |
398 | * | |
399 | * For now it is simpler to just free the pages. | |
400 | */ | |
401 | kimage_free_page_list(&extra_pages); | |
402 | ||
403 | return pages; | |
404 | } | |
405 | ||
406 | static struct page *kimage_alloc_crash_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 | * Control pages are also the only pags we must allocate | |
416 | * when loading a crash kernel. All of the other pages | |
417 | * are specified by the segments and we just memcpy | |
418 | * into them directly. | |
419 | * | |
420 | * The only case where we really need more than one of | |
421 | * these are for architectures where we cannot disable | |
422 | * the MMU and must instead generate an identity mapped | |
423 | * page table for all of the memory. | |
424 | * | |
425 | * Given the low demand this implements a very simple | |
426 | * allocator that finds the first hole of the appropriate | |
427 | * size in the reserved memory region, and allocates all | |
428 | * of the memory up to and including the hole. | |
429 | */ | |
430 | unsigned long hole_start, hole_end, size; | |
431 | struct page *pages; | |
432 | ||
433 | pages = NULL; | |
434 | size = (1 << order) << PAGE_SHIFT; | |
db6b6fb7 | 435 | hole_start = ALIGN(image->control_page, size); |
2965faa5 DY |
436 | hole_end = hole_start + size - 1; |
437 | while (hole_end <= crashk_res.end) { | |
438 | unsigned long i; | |
439 | ||
8e53c073 | 440 | cond_resched(); |
441 | ||
2965faa5 DY |
442 | if (hole_end > KEXEC_CRASH_CONTROL_MEMORY_LIMIT) |
443 | break; | |
444 | /* See if I overlap any of the segments */ | |
445 | for (i = 0; i < image->nr_segments; i++) { | |
446 | unsigned long mstart, mend; | |
447 | ||
448 | mstart = image->segment[i].mem; | |
449 | mend = mstart + image->segment[i].memsz - 1; | |
450 | if ((hole_end >= mstart) && (hole_start <= mend)) { | |
451 | /* Advance the hole to the end of the segment */ | |
db6b6fb7 | 452 | hole_start = ALIGN(mend, size); |
2965faa5 DY |
453 | hole_end = hole_start + size - 1; |
454 | break; | |
455 | } | |
456 | } | |
457 | /* If I don't overlap any segments I have found my hole! */ | |
458 | if (i == image->nr_segments) { | |
459 | pages = pfn_to_page(hole_start >> PAGE_SHIFT); | |
2861b377 | 460 | image->control_page = hole_end + 1; |
2965faa5 DY |
461 | break; |
462 | } | |
463 | } | |
2965faa5 | 464 | |
9cf38d55 LJ |
465 | /* Ensure that these pages are decrypted if SME is enabled. */ |
466 | if (pages) | |
467 | arch_kexec_post_alloc_pages(page_address(pages), 1 << order, 0); | |
468 | ||
2965faa5 DY |
469 | return pages; |
470 | } | |
471 | ||
472 | ||
473 | struct page *kimage_alloc_control_pages(struct kimage *image, | |
474 | unsigned int order) | |
475 | { | |
476 | struct page *pages = NULL; | |
477 | ||
478 | switch (image->type) { | |
479 | case KEXEC_TYPE_DEFAULT: | |
480 | pages = kimage_alloc_normal_control_pages(image, order); | |
481 | break; | |
482 | case KEXEC_TYPE_CRASH: | |
483 | pages = kimage_alloc_crash_control_pages(image, order); | |
484 | break; | |
485 | } | |
486 | ||
487 | return pages; | |
488 | } | |
489 | ||
1229384f XP |
490 | int kimage_crash_copy_vmcoreinfo(struct kimage *image) |
491 | { | |
492 | struct page *vmcoreinfo_page; | |
493 | void *safecopy; | |
494 | ||
495 | if (image->type != KEXEC_TYPE_CRASH) | |
496 | return 0; | |
497 | ||
498 | /* | |
499 | * For kdump, allocate one vmcoreinfo safe copy from the | |
500 | * crash memory. as we have arch_kexec_protect_crashkres() | |
501 | * after kexec syscall, we naturally protect it from write | |
502 | * (even read) access under kernel direct mapping. But on | |
503 | * the other hand, we still need to operate it when crash | |
504 | * happens to generate vmcoreinfo note, hereby we rely on | |
505 | * vmap for this purpose. | |
506 | */ | |
507 | vmcoreinfo_page = kimage_alloc_control_pages(image, 0); | |
508 | if (!vmcoreinfo_page) { | |
509 | pr_warn("Could not allocate vmcoreinfo buffer\n"); | |
510 | return -ENOMEM; | |
511 | } | |
512 | safecopy = vmap(&vmcoreinfo_page, 1, VM_MAP, PAGE_KERNEL); | |
513 | if (!safecopy) { | |
514 | pr_warn("Could not vmap vmcoreinfo buffer\n"); | |
515 | return -ENOMEM; | |
516 | } | |
517 | ||
518 | image->vmcoreinfo_data_copy = safecopy; | |
519 | crash_update_vmcoreinfo_safecopy(safecopy); | |
520 | ||
521 | return 0; | |
522 | } | |
523 | ||
2965faa5 DY |
524 | static int kimage_add_entry(struct kimage *image, kimage_entry_t entry) |
525 | { | |
526 | if (*image->entry != 0) | |
527 | image->entry++; | |
528 | ||
529 | if (image->entry == image->last_entry) { | |
530 | kimage_entry_t *ind_page; | |
531 | struct page *page; | |
532 | ||
533 | page = kimage_alloc_page(image, GFP_KERNEL, KIMAGE_NO_DEST); | |
534 | if (!page) | |
535 | return -ENOMEM; | |
536 | ||
537 | ind_page = page_address(page); | |
43546d86 | 538 | *image->entry = virt_to_boot_phys(ind_page) | IND_INDIRECTION; |
2965faa5 DY |
539 | image->entry = ind_page; |
540 | image->last_entry = ind_page + | |
541 | ((PAGE_SIZE/sizeof(kimage_entry_t)) - 1); | |
542 | } | |
543 | *image->entry = entry; | |
544 | image->entry++; | |
545 | *image->entry = 0; | |
546 | ||
547 | return 0; | |
548 | } | |
549 | ||
550 | static int kimage_set_destination(struct kimage *image, | |
551 | unsigned long destination) | |
552 | { | |
2965faa5 | 553 | destination &= PAGE_MASK; |
2965faa5 | 554 | |
32d0c98e | 555 | return kimage_add_entry(image, destination | IND_DESTINATION); |
2965faa5 DY |
556 | } |
557 | ||
558 | ||
559 | static int kimage_add_page(struct kimage *image, unsigned long page) | |
560 | { | |
2965faa5 | 561 | page &= PAGE_MASK; |
2965faa5 | 562 | |
32d0c98e | 563 | return kimage_add_entry(image, page | IND_SOURCE); |
2965faa5 DY |
564 | } |
565 | ||
566 | ||
567 | static void kimage_free_extra_pages(struct kimage *image) | |
568 | { | |
569 | /* Walk through and free any extra destination pages I may have */ | |
570 | kimage_free_page_list(&image->dest_pages); | |
571 | ||
572 | /* Walk through and free any unusable pages I have cached */ | |
573 | kimage_free_page_list(&image->unusable_pages); | |
574 | ||
575 | } | |
de68e4da | 576 | |
2965faa5 DY |
577 | void kimage_terminate(struct kimage *image) |
578 | { | |
579 | if (*image->entry != 0) | |
580 | image->entry++; | |
581 | ||
582 | *image->entry = IND_DONE; | |
583 | } | |
584 | ||
585 | #define for_each_kimage_entry(image, ptr, entry) \ | |
586 | for (ptr = &image->head; (entry = *ptr) && !(entry & IND_DONE); \ | |
587 | ptr = (entry & IND_INDIRECTION) ? \ | |
43546d86 | 588 | boot_phys_to_virt((entry & PAGE_MASK)) : ptr + 1) |
2965faa5 DY |
589 | |
590 | static void kimage_free_entry(kimage_entry_t entry) | |
591 | { | |
592 | struct page *page; | |
593 | ||
43546d86 | 594 | page = boot_pfn_to_page(entry >> PAGE_SHIFT); |
2965faa5 DY |
595 | kimage_free_pages(page); |
596 | } | |
597 | ||
598 | void kimage_free(struct kimage *image) | |
599 | { | |
600 | kimage_entry_t *ptr, entry; | |
601 | kimage_entry_t ind = 0; | |
602 | ||
603 | if (!image) | |
604 | return; | |
605 | ||
1229384f XP |
606 | if (image->vmcoreinfo_data_copy) { |
607 | crash_update_vmcoreinfo_safecopy(NULL); | |
608 | vunmap(image->vmcoreinfo_data_copy); | |
609 | } | |
610 | ||
2965faa5 DY |
611 | kimage_free_extra_pages(image); |
612 | for_each_kimage_entry(image, ptr, entry) { | |
613 | if (entry & IND_INDIRECTION) { | |
614 | /* Free the previous indirection page */ | |
615 | if (ind & IND_INDIRECTION) | |
616 | kimage_free_entry(ind); | |
617 | /* Save this indirection page until we are | |
618 | * done with it. | |
619 | */ | |
620 | ind = entry; | |
621 | } else if (entry & IND_SOURCE) | |
622 | kimage_free_entry(entry); | |
623 | } | |
624 | /* Free the final indirection page */ | |
625 | if (ind & IND_INDIRECTION) | |
626 | kimage_free_entry(ind); | |
627 | ||
628 | /* Handle any machine specific cleanup */ | |
629 | machine_kexec_cleanup(image); | |
630 | ||
631 | /* Free the kexec control pages... */ | |
632 | kimage_free_page_list(&image->control_pages); | |
633 | ||
634 | /* | |
635 | * Free up any temporary buffers allocated. This might hit if | |
636 | * error occurred much later after buffer allocation. | |
637 | */ | |
638 | if (image->file_mode) | |
639 | kimage_file_post_load_cleanup(image); | |
640 | ||
641 | kfree(image); | |
642 | } | |
643 | ||
644 | static kimage_entry_t *kimage_dst_used(struct kimage *image, | |
645 | unsigned long page) | |
646 | { | |
647 | kimage_entry_t *ptr, entry; | |
648 | unsigned long destination = 0; | |
649 | ||
650 | for_each_kimage_entry(image, ptr, entry) { | |
651 | if (entry & IND_DESTINATION) | |
652 | destination = entry & PAGE_MASK; | |
653 | else if (entry & IND_SOURCE) { | |
654 | if (page == destination) | |
655 | return ptr; | |
656 | destination += PAGE_SIZE; | |
657 | } | |
658 | } | |
659 | ||
660 | return NULL; | |
661 | } | |
662 | ||
663 | static struct page *kimage_alloc_page(struct kimage *image, | |
664 | gfp_t gfp_mask, | |
665 | unsigned long destination) | |
666 | { | |
667 | /* | |
668 | * Here we implement safeguards to ensure that a source page | |
669 | * is not copied to its destination page before the data on | |
670 | * the destination page is no longer useful. | |
671 | * | |
672 | * To do this we maintain the invariant that a source page is | |
673 | * either its own destination page, or it is not a | |
674 | * destination page at all. | |
675 | * | |
676 | * That is slightly stronger than required, but the proof | |
677 | * that no problems will not occur is trivial, and the | |
678 | * implementation is simply to verify. | |
679 | * | |
680 | * When allocating all pages normally this algorithm will run | |
681 | * in O(N) time, but in the worst case it will run in O(N^2) | |
682 | * time. If the runtime is a problem the data structures can | |
683 | * be fixed. | |
684 | */ | |
685 | struct page *page; | |
686 | unsigned long addr; | |
687 | ||
688 | /* | |
689 | * Walk through the list of destination pages, and see if I | |
690 | * have a match. | |
691 | */ | |
692 | list_for_each_entry(page, &image->dest_pages, lru) { | |
43546d86 | 693 | addr = page_to_boot_pfn(page) << PAGE_SHIFT; |
2965faa5 DY |
694 | if (addr == destination) { |
695 | list_del(&page->lru); | |
696 | return page; | |
697 | } | |
698 | } | |
699 | page = NULL; | |
700 | while (1) { | |
701 | kimage_entry_t *old; | |
702 | ||
703 | /* Allocate a page, if we run out of memory give up */ | |
704 | page = kimage_alloc_pages(gfp_mask, 0); | |
705 | if (!page) | |
706 | return NULL; | |
707 | /* If the page cannot be used file it away */ | |
43546d86 | 708 | if (page_to_boot_pfn(page) > |
2965faa5 DY |
709 | (KEXEC_SOURCE_MEMORY_LIMIT >> PAGE_SHIFT)) { |
710 | list_add(&page->lru, &image->unusable_pages); | |
711 | continue; | |
712 | } | |
43546d86 | 713 | addr = page_to_boot_pfn(page) << PAGE_SHIFT; |
2965faa5 DY |
714 | |
715 | /* If it is the destination page we want use it */ | |
716 | if (addr == destination) | |
717 | break; | |
718 | ||
719 | /* If the page is not a destination page use it */ | |
720 | if (!kimage_is_destination_range(image, addr, | |
816d334a | 721 | addr + PAGE_SIZE - 1)) |
2965faa5 DY |
722 | break; |
723 | ||
724 | /* | |
725 | * I know that the page is someones destination page. | |
726 | * See if there is already a source page for this | |
727 | * destination page. And if so swap the source pages. | |
728 | */ | |
729 | old = kimage_dst_used(image, addr); | |
730 | if (old) { | |
731 | /* If so move it */ | |
732 | unsigned long old_addr; | |
733 | struct page *old_page; | |
734 | ||
735 | old_addr = *old & PAGE_MASK; | |
43546d86 | 736 | old_page = boot_pfn_to_page(old_addr >> PAGE_SHIFT); |
2965faa5 DY |
737 | copy_highpage(page, old_page); |
738 | *old = addr | (*old & ~PAGE_MASK); | |
739 | ||
740 | /* The old page I have found cannot be a | |
741 | * destination page, so return it if it's | |
742 | * gfp_flags honor the ones passed in. | |
743 | */ | |
744 | if (!(gfp_mask & __GFP_HIGHMEM) && | |
745 | PageHighMem(old_page)) { | |
746 | kimage_free_pages(old_page); | |
747 | continue; | |
748 | } | |
2965faa5 DY |
749 | page = old_page; |
750 | break; | |
751 | } | |
752 | /* Place the page on the destination list, to be used later */ | |
753 | list_add(&page->lru, &image->dest_pages); | |
754 | } | |
755 | ||
756 | return page; | |
757 | } | |
758 | ||
759 | static int kimage_load_normal_segment(struct kimage *image, | |
760 | struct kexec_segment *segment) | |
761 | { | |
762 | unsigned long maddr; | |
763 | size_t ubytes, mbytes; | |
764 | int result; | |
765 | unsigned char __user *buf = NULL; | |
766 | unsigned char *kbuf = NULL; | |
767 | ||
2965faa5 DY |
768 | if (image->file_mode) |
769 | kbuf = segment->kbuf; | |
770 | else | |
771 | buf = segment->buf; | |
772 | ubytes = segment->bufsz; | |
773 | mbytes = segment->memsz; | |
774 | maddr = segment->mem; | |
775 | ||
776 | result = kimage_set_destination(image, maddr); | |
777 | if (result < 0) | |
778 | goto out; | |
779 | ||
780 | while (mbytes) { | |
781 | struct page *page; | |
782 | char *ptr; | |
783 | size_t uchunk, mchunk; | |
784 | ||
785 | page = kimage_alloc_page(image, GFP_HIGHUSER, maddr); | |
786 | if (!page) { | |
787 | result = -ENOMEM; | |
788 | goto out; | |
789 | } | |
43546d86 | 790 | result = kimage_add_page(image, page_to_boot_pfn(page) |
2965faa5 DY |
791 | << PAGE_SHIFT); |
792 | if (result < 0) | |
793 | goto out; | |
794 | ||
948084f0 | 795 | ptr = kmap_local_page(page); |
2965faa5 DY |
796 | /* Start with a clear page */ |
797 | clear_page(ptr); | |
798 | ptr += maddr & ~PAGE_MASK; | |
799 | mchunk = min_t(size_t, mbytes, | |
800 | PAGE_SIZE - (maddr & ~PAGE_MASK)); | |
801 | uchunk = min(ubytes, mchunk); | |
802 | ||
803 | /* For file based kexec, source pages are in kernel memory */ | |
804 | if (image->file_mode) | |
805 | memcpy(ptr, kbuf, uchunk); | |
806 | else | |
807 | result = copy_from_user(ptr, buf, uchunk); | |
948084f0 | 808 | kunmap_local(ptr); |
2965faa5 DY |
809 | if (result) { |
810 | result = -EFAULT; | |
811 | goto out; | |
812 | } | |
813 | ubytes -= uchunk; | |
814 | maddr += mchunk; | |
815 | if (image->file_mode) | |
816 | kbuf += mchunk; | |
817 | else | |
818 | buf += mchunk; | |
819 | mbytes -= mchunk; | |
a8311f64 JF |
820 | |
821 | cond_resched(); | |
2965faa5 DY |
822 | } |
823 | out: | |
824 | return result; | |
825 | } | |
826 | ||
827 | static int kimage_load_crash_segment(struct kimage *image, | |
828 | struct kexec_segment *segment) | |
829 | { | |
830 | /* For crash dumps kernels we simply copy the data from | |
831 | * user space to it's destination. | |
832 | * We do things a page at a time for the sake of kmap. | |
833 | */ | |
834 | unsigned long maddr; | |
835 | size_t ubytes, mbytes; | |
836 | int result; | |
837 | unsigned char __user *buf = NULL; | |
838 | unsigned char *kbuf = NULL; | |
839 | ||
840 | result = 0; | |
841 | if (image->file_mode) | |
842 | kbuf = segment->kbuf; | |
843 | else | |
844 | buf = segment->buf; | |
845 | ubytes = segment->bufsz; | |
846 | mbytes = segment->memsz; | |
847 | maddr = segment->mem; | |
848 | while (mbytes) { | |
849 | struct page *page; | |
850 | char *ptr; | |
851 | size_t uchunk, mchunk; | |
852 | ||
43546d86 | 853 | page = boot_pfn_to_page(maddr >> PAGE_SHIFT); |
2965faa5 DY |
854 | if (!page) { |
855 | result = -ENOMEM; | |
856 | goto out; | |
857 | } | |
9cf38d55 | 858 | arch_kexec_post_alloc_pages(page_address(page), 1, 0); |
948084f0 | 859 | ptr = kmap_local_page(page); |
2965faa5 DY |
860 | ptr += maddr & ~PAGE_MASK; |
861 | mchunk = min_t(size_t, mbytes, | |
862 | PAGE_SIZE - (maddr & ~PAGE_MASK)); | |
863 | uchunk = min(ubytes, mchunk); | |
864 | if (mchunk > uchunk) { | |
865 | /* Zero the trailing part of the page */ | |
866 | memset(ptr + uchunk, 0, mchunk - uchunk); | |
867 | } | |
868 | ||
869 | /* For file based kexec, source pages are in kernel memory */ | |
870 | if (image->file_mode) | |
871 | memcpy(ptr, kbuf, uchunk); | |
872 | else | |
873 | result = copy_from_user(ptr, buf, uchunk); | |
874 | kexec_flush_icache_page(page); | |
948084f0 | 875 | kunmap_local(ptr); |
9cf38d55 | 876 | arch_kexec_pre_free_pages(page_address(page), 1); |
2965faa5 DY |
877 | if (result) { |
878 | result = -EFAULT; | |
879 | goto out; | |
880 | } | |
881 | ubytes -= uchunk; | |
882 | maddr += mchunk; | |
883 | if (image->file_mode) | |
884 | kbuf += mchunk; | |
885 | else | |
886 | buf += mchunk; | |
887 | mbytes -= mchunk; | |
a8311f64 JF |
888 | |
889 | cond_resched(); | |
2965faa5 DY |
890 | } |
891 | out: | |
892 | return result; | |
893 | } | |
894 | ||
895 | int kimage_load_segment(struct kimage *image, | |
896 | struct kexec_segment *segment) | |
897 | { | |
898 | int result = -ENOMEM; | |
899 | ||
900 | switch (image->type) { | |
901 | case KEXEC_TYPE_DEFAULT: | |
902 | result = kimage_load_normal_segment(image, segment); | |
903 | break; | |
904 | case KEXEC_TYPE_CRASH: | |
905 | result = kimage_load_crash_segment(image, segment); | |
906 | break; | |
907 | } | |
908 | ||
909 | return result; | |
910 | } | |
911 | ||
a42aaad2 RR |
912 | struct kexec_load_limit { |
913 | /* Mutex protects the limit count. */ | |
914 | struct mutex mutex; | |
915 | int limit; | |
916 | }; | |
917 | ||
918 | static struct kexec_load_limit load_limit_reboot = { | |
919 | .mutex = __MUTEX_INITIALIZER(load_limit_reboot.mutex), | |
920 | .limit = -1, | |
921 | }; | |
922 | ||
923 | static struct kexec_load_limit load_limit_panic = { | |
924 | .mutex = __MUTEX_INITIALIZER(load_limit_panic.mutex), | |
925 | .limit = -1, | |
926 | }; | |
927 | ||
2965faa5 DY |
928 | struct kimage *kexec_image; |
929 | struct kimage *kexec_crash_image; | |
7e99f8b6 | 930 | static int kexec_load_disabled; |
a42aaad2 | 931 | |
a467257f | 932 | #ifdef CONFIG_SYSCTL |
a42aaad2 RR |
933 | static int kexec_limit_handler(struct ctl_table *table, int write, |
934 | void *buffer, size_t *lenp, loff_t *ppos) | |
935 | { | |
936 | struct kexec_load_limit *limit = table->data; | |
937 | int val; | |
938 | struct ctl_table tmp = { | |
939 | .data = &val, | |
940 | .maxlen = sizeof(val), | |
941 | .mode = table->mode, | |
942 | }; | |
943 | int ret; | |
944 | ||
945 | if (write) { | |
946 | ret = proc_dointvec(&tmp, write, buffer, lenp, ppos); | |
947 | if (ret) | |
948 | return ret; | |
949 | ||
950 | if (val < 0) | |
951 | return -EINVAL; | |
952 | ||
953 | mutex_lock(&limit->mutex); | |
954 | if (limit->limit != -1 && val >= limit->limit) | |
955 | ret = -EINVAL; | |
956 | else | |
957 | limit->limit = val; | |
958 | mutex_unlock(&limit->mutex); | |
959 | ||
960 | return ret; | |
961 | } | |
962 | ||
963 | mutex_lock(&limit->mutex); | |
964 | val = limit->limit; | |
965 | mutex_unlock(&limit->mutex); | |
966 | ||
967 | return proc_dointvec(&tmp, write, buffer, lenp, ppos); | |
968 | } | |
969 | ||
a467257f | 970 | static struct ctl_table kexec_core_sysctls[] = { |
971 | { | |
972 | .procname = "kexec_load_disabled", | |
973 | .data = &kexec_load_disabled, | |
974 | .maxlen = sizeof(int), | |
975 | .mode = 0644, | |
976 | /* only handle a transition from default "0" to "1" */ | |
977 | .proc_handler = proc_dointvec_minmax, | |
978 | .extra1 = SYSCTL_ONE, | |
979 | .extra2 = SYSCTL_ONE, | |
980 | }, | |
a42aaad2 RR |
981 | { |
982 | .procname = "kexec_load_limit_panic", | |
983 | .data = &load_limit_panic, | |
984 | .mode = 0644, | |
985 | .proc_handler = kexec_limit_handler, | |
986 | }, | |
987 | { | |
988 | .procname = "kexec_load_limit_reboot", | |
989 | .data = &load_limit_reboot, | |
990 | .mode = 0644, | |
991 | .proc_handler = kexec_limit_handler, | |
992 | }, | |
a467257f | 993 | { } |
994 | }; | |
995 | ||
996 | static int __init kexec_core_sysctl_init(void) | |
997 | { | |
998 | register_sysctl_init("kernel", kexec_core_sysctls); | |
999 | return 0; | |
1000 | } | |
1001 | late_initcall(kexec_core_sysctl_init); | |
1002 | #endif | |
2965faa5 | 1003 | |
a42aaad2 | 1004 | bool kexec_load_permitted(int kexec_image_type) |
7e99f8b6 | 1005 | { |
a42aaad2 RR |
1006 | struct kexec_load_limit *limit; |
1007 | ||
7e99f8b6 RR |
1008 | /* |
1009 | * Only the superuser can use the kexec syscall and if it has not | |
1010 | * been disabled. | |
1011 | */ | |
a42aaad2 RR |
1012 | if (!capable(CAP_SYS_BOOT) || kexec_load_disabled) |
1013 | return false; | |
1014 | ||
1015 | /* Check limit counter and decrease it.*/ | |
1016 | limit = (kexec_image_type == KEXEC_TYPE_CRASH) ? | |
1017 | &load_limit_panic : &load_limit_reboot; | |
1018 | mutex_lock(&limit->mutex); | |
1019 | if (!limit->limit) { | |
1020 | mutex_unlock(&limit->mutex); | |
1021 | return false; | |
1022 | } | |
1023 | if (limit->limit != -1) | |
1024 | limit->limit--; | |
1025 | mutex_unlock(&limit->mutex); | |
1026 | ||
1027 | return true; | |
7e99f8b6 RR |
1028 | } |
1029 | ||
7bbee5ca HK |
1030 | /* |
1031 | * No panic_cpu check version of crash_kexec(). This function is called | |
1032 | * only when panic_cpu holds the current CPU number; this is the only CPU | |
1033 | * which processes crash_kexec routines. | |
1034 | */ | |
c207aee4 | 1035 | void __noclone __crash_kexec(struct pt_regs *regs) |
2965faa5 | 1036 | { |
05c62574 | 1037 | /* Take the kexec_lock here to prevent sys_kexec_load |
2965faa5 DY |
1038 | * running on one cpu from replacing the crash kernel |
1039 | * we are using after a panic on a different cpu. | |
1040 | * | |
1041 | * If the crash kernel was not located in a fixed area | |
1042 | * of memory the xchg(&kexec_crash_image) would be | |
1043 | * sufficient. But since I reuse the memory... | |
1044 | */ | |
05c62574 | 1045 | if (kexec_trylock()) { |
2965faa5 DY |
1046 | if (kexec_crash_image) { |
1047 | struct pt_regs fixed_regs; | |
1048 | ||
1049 | crash_setup_regs(&fixed_regs, regs); | |
1050 | crash_save_vmcoreinfo(); | |
1051 | machine_crash_shutdown(&fixed_regs); | |
1052 | machine_kexec(kexec_crash_image); | |
1053 | } | |
05c62574 | 1054 | kexec_unlock(); |
2965faa5 DY |
1055 | } |
1056 | } | |
c207aee4 | 1057 | STACK_FRAME_NON_STANDARD(__crash_kexec); |
2965faa5 | 1058 | |
400031e0 | 1059 | __bpf_kfunc void crash_kexec(struct pt_regs *regs) |
7bbee5ca HK |
1060 | { |
1061 | int old_cpu, this_cpu; | |
1062 | ||
1063 | /* | |
1064 | * Only one CPU is allowed to execute the crash_kexec() code as with | |
1065 | * panic(). Otherwise parallel calls of panic() and crash_kexec() | |
1066 | * may stop each other. To exclude them, we use panic_cpu here too. | |
1067 | */ | |
0311d827 | 1068 | old_cpu = PANIC_CPU_INVALID; |
7bbee5ca | 1069 | this_cpu = raw_smp_processor_id(); |
0311d827 UB |
1070 | |
1071 | if (atomic_try_cmpxchg(&panic_cpu, &old_cpu, this_cpu)) { | |
7bbee5ca HK |
1072 | /* This is the 1st CPU which comes here, so go ahead. */ |
1073 | __crash_kexec(regs); | |
1074 | ||
1075 | /* | |
1076 | * Reset panic_cpu to allow another panic()/crash_kexec() | |
1077 | * call. | |
1078 | */ | |
1079 | atomic_set(&panic_cpu, PANIC_CPU_INVALID); | |
1080 | } | |
1081 | } | |
1082 | ||
16c6006a ZL |
1083 | static inline resource_size_t crash_resource_size(const struct resource *res) |
1084 | { | |
1085 | return !res->end ? 0 : resource_size(res); | |
1086 | } | |
1087 | ||
7bb5da0d | 1088 | ssize_t crash_get_memory_size(void) |
2965faa5 | 1089 | { |
7bb5da0d VS |
1090 | ssize_t size = 0; |
1091 | ||
05c62574 | 1092 | if (!kexec_trylock()) |
7bb5da0d | 1093 | return -EBUSY; |
2965faa5 | 1094 | |
16c6006a ZL |
1095 | size += crash_resource_size(&crashk_res); |
1096 | size += crash_resource_size(&crashk_low_res); | |
7bb5da0d | 1097 | |
05c62574 | 1098 | kexec_unlock(); |
2965faa5 DY |
1099 | return size; |
1100 | } | |
1101 | ||
5b7bfb32 ZL |
1102 | static int __crash_shrink_memory(struct resource *old_res, |
1103 | unsigned long new_size) | |
1104 | { | |
1105 | struct resource *ram_res; | |
1106 | ||
1107 | ram_res = kzalloc(sizeof(*ram_res), GFP_KERNEL); | |
1108 | if (!ram_res) | |
1109 | return -ENOMEM; | |
1110 | ||
1111 | ram_res->start = old_res->start + new_size; | |
1112 | ram_res->end = old_res->end; | |
1113 | ram_res->flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM; | |
1114 | ram_res->name = "System RAM"; | |
1115 | ||
1116 | if (!new_size) { | |
1117 | release_resource(old_res); | |
1118 | old_res->start = 0; | |
1119 | old_res->end = 0; | |
1120 | } else { | |
1121 | crashk_res.end = ram_res->start - 1; | |
1122 | } | |
1123 | ||
1124 | crash_free_reserved_phys_range(ram_res->start, ram_res->end); | |
1125 | insert_resource(&iomem_resource, ram_res); | |
1126 | ||
1127 | return 0; | |
1128 | } | |
1129 | ||
2965faa5 DY |
1130 | int crash_shrink_memory(unsigned long new_size) |
1131 | { | |
1132 | int ret = 0; | |
16c6006a | 1133 | unsigned long old_size, low_size; |
2965faa5 | 1134 | |
05c62574 | 1135 | if (!kexec_trylock()) |
7bb5da0d | 1136 | return -EBUSY; |
2965faa5 DY |
1137 | |
1138 | if (kexec_crash_image) { | |
1139 | ret = -ENOENT; | |
1140 | goto unlock; | |
1141 | } | |
16c6006a ZL |
1142 | |
1143 | low_size = crash_resource_size(&crashk_low_res); | |
1144 | old_size = crash_resource_size(&crashk_res) + low_size; | |
1cba6c43 | 1145 | new_size = roundup(new_size, KEXEC_CRASH_MEM_ALIGN); |
2965faa5 DY |
1146 | if (new_size >= old_size) { |
1147 | ret = (new_size == old_size) ? 0 : -EINVAL; | |
1148 | goto unlock; | |
1149 | } | |
1150 | ||
16c6006a ZL |
1151 | /* |
1152 | * (low_size > new_size) implies that low_size is greater than zero. | |
1153 | * This also means that if low_size is zero, the else branch is taken. | |
1154 | * | |
1155 | * If low_size is greater than 0, (low_size > new_size) indicates that | |
1156 | * crashk_low_res also needs to be shrunken. Otherwise, only crashk_res | |
1157 | * needs to be shrunken. | |
1158 | */ | |
1159 | if (low_size > new_size) { | |
1160 | ret = __crash_shrink_memory(&crashk_res, 0); | |
1161 | if (ret) | |
1162 | goto unlock; | |
1163 | ||
1164 | ret = __crash_shrink_memory(&crashk_low_res, new_size); | |
1165 | } else { | |
1166 | ret = __crash_shrink_memory(&crashk_res, new_size - low_size); | |
1167 | } | |
1168 | ||
1169 | /* Swap crashk_res and crashk_low_res if needed */ | |
1170 | if (!crashk_res.end && crashk_low_res.end) { | |
1171 | crashk_res.start = crashk_low_res.start; | |
1172 | crashk_res.end = crashk_low_res.end; | |
1173 | release_resource(&crashk_low_res); | |
1174 | crashk_low_res.start = 0; | |
1175 | crashk_low_res.end = 0; | |
1176 | insert_resource(&iomem_resource, &crashk_res); | |
1177 | } | |
2965faa5 DY |
1178 | |
1179 | unlock: | |
05c62574 | 1180 | kexec_unlock(); |
2965faa5 DY |
1181 | return ret; |
1182 | } | |
1183 | ||
2965faa5 DY |
1184 | void crash_save_cpu(struct pt_regs *regs, int cpu) |
1185 | { | |
1186 | struct elf_prstatus prstatus; | |
1187 | u32 *buf; | |
1188 | ||
1189 | if ((cpu < 0) || (cpu >= nr_cpu_ids)) | |
1190 | return; | |
1191 | ||
1192 | /* Using ELF notes here is opportunistic. | |
1193 | * I need a well defined structure format | |
1194 | * for the data I pass, and I need tags | |
1195 | * on the data to indicate what information I have | |
1196 | * squirrelled away. ELF notes happen to provide | |
1197 | * all of that, so there is no need to invent something new. | |
1198 | */ | |
1199 | buf = (u32 *)per_cpu_ptr(crash_notes, cpu); | |
1200 | if (!buf) | |
1201 | return; | |
1202 | memset(&prstatus, 0, sizeof(prstatus)); | |
f2485a2d | 1203 | prstatus.common.pr_pid = current->pid; |
9554e908 | 1204 | elf_core_copy_regs(&prstatus.pr_reg, regs); |
2965faa5 DY |
1205 | buf = append_elf_note(buf, KEXEC_CORE_NOTE_NAME, NT_PRSTATUS, |
1206 | &prstatus, sizeof(prstatus)); | |
1207 | final_note(buf); | |
1208 | } | |
1209 | ||
2965faa5 DY |
1210 | /* |
1211 | * Move into place and start executing a preloaded standalone | |
1212 | * executable. If nothing was preloaded return an error. | |
1213 | */ | |
1214 | int kernel_kexec(void) | |
1215 | { | |
1216 | int error = 0; | |
1217 | ||
05c62574 | 1218 | if (!kexec_trylock()) |
2965faa5 DY |
1219 | return -EBUSY; |
1220 | if (!kexec_image) { | |
1221 | error = -EINVAL; | |
1222 | goto Unlock; | |
1223 | } | |
1224 | ||
1225 | #ifdef CONFIG_KEXEC_JUMP | |
1226 | if (kexec_image->preserve_context) { | |
2965faa5 DY |
1227 | pm_prepare_console(); |
1228 | error = freeze_processes(); | |
1229 | if (error) { | |
1230 | error = -EBUSY; | |
1231 | goto Restore_console; | |
1232 | } | |
1233 | suspend_console(); | |
1234 | error = dpm_suspend_start(PMSG_FREEZE); | |
1235 | if (error) | |
1236 | goto Resume_console; | |
1237 | /* At this point, dpm_suspend_start() has been called, | |
1238 | * but *not* dpm_suspend_end(). We *must* call | |
1239 | * dpm_suspend_end() now. Otherwise, drivers for | |
1240 | * some devices (e.g. interrupt controllers) become | |
1241 | * desynchronized with the actual state of the | |
1242 | * hardware at resume time, and evil weirdness ensues. | |
1243 | */ | |
1244 | error = dpm_suspend_end(PMSG_FREEZE); | |
1245 | if (error) | |
1246 | goto Resume_devices; | |
2f1a6fbb | 1247 | error = suspend_disable_secondary_cpus(); |
2965faa5 DY |
1248 | if (error) |
1249 | goto Enable_cpus; | |
1250 | local_irq_disable(); | |
1251 | error = syscore_suspend(); | |
1252 | if (error) | |
1253 | goto Enable_irqs; | |
1254 | } else | |
1255 | #endif | |
1256 | { | |
1257 | kexec_in_progress = true; | |
a119b4e5 | 1258 | kernel_restart_prepare("kexec reboot"); |
2965faa5 | 1259 | migrate_to_reboot_cpu(); |
7bb94380 | 1260 | syscore_shutdown(); |
2965faa5 DY |
1261 | |
1262 | /* | |
1263 | * migrate_to_reboot_cpu() disables CPU hotplug assuming that | |
1264 | * no further code needs to use CPU hotplug (which is true in | |
1265 | * the reboot case). However, the kexec path depends on using | |
1266 | * CPU hotplug again; so re-enable it here. | |
1267 | */ | |
1268 | cpu_hotplug_enable(); | |
d42cc530 | 1269 | pr_notice("Starting new kernel\n"); |
2965faa5 DY |
1270 | machine_shutdown(); |
1271 | } | |
1272 | ||
b2075dbb | 1273 | kmsg_dump(KMSG_DUMP_SHUTDOWN); |
2965faa5 DY |
1274 | machine_kexec(kexec_image); |
1275 | ||
1276 | #ifdef CONFIG_KEXEC_JUMP | |
1277 | if (kexec_image->preserve_context) { | |
1278 | syscore_resume(); | |
1279 | Enable_irqs: | |
1280 | local_irq_enable(); | |
1281 | Enable_cpus: | |
2f1a6fbb | 1282 | suspend_enable_secondary_cpus(); |
2965faa5 DY |
1283 | dpm_resume_start(PMSG_RESTORE); |
1284 | Resume_devices: | |
1285 | dpm_resume_end(PMSG_RESTORE); | |
1286 | Resume_console: | |
1287 | resume_console(); | |
1288 | thaw_processes(); | |
1289 | Restore_console: | |
1290 | pm_restore_console(); | |
2965faa5 DY |
1291 | } |
1292 | #endif | |
1293 | ||
1294 | Unlock: | |
05c62574 | 1295 | kexec_unlock(); |
2965faa5 DY |
1296 | return error; |
1297 | } |