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Commit | Line | Data |
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dc009d92 EB |
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 | ||
c59ede7b | 9 | #include <linux/capability.h> |
dc009d92 EB |
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> | |
8c5a1cf0 | 15 | #include <linux/mutex.h> |
dc009d92 EB |
16 | #include <linux/list.h> |
17 | #include <linux/highmem.h> | |
18 | #include <linux/syscalls.h> | |
19 | #include <linux/reboot.h> | |
dc009d92 | 20 | #include <linux/ioport.h> |
6e274d14 | 21 | #include <linux/hardirq.h> |
85916f81 MD |
22 | #include <linux/elf.h> |
23 | #include <linux/elfcore.h> | |
273b281f | 24 | #include <generated/utsrelease.h> |
fd59d231 KO |
25 | #include <linux/utsname.h> |
26 | #include <linux/numa.h> | |
3ab83521 HY |
27 | #include <linux/suspend.h> |
28 | #include <linux/device.h> | |
89081d17 HY |
29 | #include <linux/freezer.h> |
30 | #include <linux/pm.h> | |
31 | #include <linux/cpu.h> | |
32 | #include <linux/console.h> | |
5f41b8cd | 33 | #include <linux/vmalloc.h> |
06a7f711 | 34 | #include <linux/swap.h> |
0f4bd46e | 35 | #include <linux/kmsg_dump.h> |
19234c08 | 36 | #include <linux/syscore_ops.h> |
6e274d14 | 37 | |
dc009d92 EB |
38 | #include <asm/page.h> |
39 | #include <asm/uaccess.h> | |
40 | #include <asm/io.h> | |
41 | #include <asm/system.h> | |
fd59d231 | 42 | #include <asm/sections.h> |
dc009d92 | 43 | |
cc571658 | 44 | /* Per cpu memory for storing cpu states in case of system crash. */ |
43cf38eb | 45 | note_buf_t __percpu *crash_notes; |
cc571658 | 46 | |
fd59d231 | 47 | /* vmcoreinfo stuff */ |
edb79a21 | 48 | static unsigned char vmcoreinfo_data[VMCOREINFO_BYTES]; |
fd59d231 | 49 | u32 vmcoreinfo_note[VMCOREINFO_NOTE_SIZE/4]; |
d768281e KO |
50 | size_t vmcoreinfo_size; |
51 | size_t vmcoreinfo_max_size = sizeof(vmcoreinfo_data); | |
fd59d231 | 52 | |
dc009d92 EB |
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 | ||
6e274d14 AN |
61 | int kexec_should_crash(struct task_struct *p) |
62 | { | |
b460cbc5 | 63 | if (in_interrupt() || !p->pid || is_global_init(p) || panic_on_oops) |
6e274d14 AN |
64 | return 1; |
65 | return 0; | |
66 | } | |
67 | ||
dc009d92 EB |
68 | /* |
69 | * When kexec transitions to the new kernel there is a one-to-one | |
70 | * mapping between physical and virtual addresses. On processors | |
71 | * where you can disable the MMU this is trivial, and easy. For | |
72 | * others it is still a simple predictable page table to setup. | |
73 | * | |
74 | * In that environment kexec copies the new kernel to its final | |
75 | * resting place. This means I can only support memory whose | |
76 | * physical address can fit in an unsigned long. In particular | |
77 | * addresses where (pfn << PAGE_SHIFT) > ULONG_MAX cannot be handled. | |
78 | * If the assembly stub has more restrictive requirements | |
79 | * KEXEC_SOURCE_MEMORY_LIMIT and KEXEC_DEST_MEMORY_LIMIT can be | |
80 | * defined more restrictively in <asm/kexec.h>. | |
81 | * | |
82 | * The code for the transition from the current kernel to the | |
83 | * the new kernel is placed in the control_code_buffer, whose size | |
163f6876 | 84 | * is given by KEXEC_CONTROL_PAGE_SIZE. In the best case only a single |
dc009d92 EB |
85 | * page of memory is necessary, but some architectures require more. |
86 | * Because this memory must be identity mapped in the transition from | |
87 | * virtual to physical addresses it must live in the range | |
88 | * 0 - TASK_SIZE, as only the user space mappings are arbitrarily | |
89 | * modifiable. | |
90 | * | |
91 | * The assembly stub in the control code buffer is passed a linked list | |
92 | * of descriptor pages detailing the source pages of the new kernel, | |
93 | * and the destination addresses of those source pages. As this data | |
94 | * structure is not used in the context of the current OS, it must | |
95 | * be self-contained. | |
96 | * | |
97 | * The code has been made to work with highmem pages and will use a | |
98 | * destination page in its final resting place (if it happens | |
99 | * to allocate it). The end product of this is that most of the | |
100 | * physical address space, and most of RAM can be used. | |
101 | * | |
102 | * Future directions include: | |
103 | * - allocating a page table with the control code buffer identity | |
104 | * mapped, to simplify machine_kexec and make kexec_on_panic more | |
105 | * reliable. | |
106 | */ | |
107 | ||
108 | /* | |
109 | * KIMAGE_NO_DEST is an impossible destination address..., for | |
110 | * allocating pages whose destination address we do not care about. | |
111 | */ | |
112 | #define KIMAGE_NO_DEST (-1UL) | |
113 | ||
72414d3f MS |
114 | static int kimage_is_destination_range(struct kimage *image, |
115 | unsigned long start, unsigned long end); | |
116 | static struct page *kimage_alloc_page(struct kimage *image, | |
9796fdd8 | 117 | gfp_t gfp_mask, |
72414d3f | 118 | unsigned long dest); |
dc009d92 EB |
119 | |
120 | static int do_kimage_alloc(struct kimage **rimage, unsigned long entry, | |
72414d3f MS |
121 | unsigned long nr_segments, |
122 | struct kexec_segment __user *segments) | |
dc009d92 EB |
123 | { |
124 | size_t segment_bytes; | |
125 | struct kimage *image; | |
126 | unsigned long i; | |
127 | int result; | |
128 | ||
129 | /* Allocate a controlling structure */ | |
130 | result = -ENOMEM; | |
4668edc3 | 131 | image = kzalloc(sizeof(*image), GFP_KERNEL); |
72414d3f | 132 | if (!image) |
dc009d92 | 133 | goto out; |
72414d3f | 134 | |
dc009d92 EB |
135 | image->head = 0; |
136 | image->entry = &image->head; | |
137 | image->last_entry = &image->head; | |
138 | image->control_page = ~0; /* By default this does not apply */ | |
139 | image->start = entry; | |
140 | image->type = KEXEC_TYPE_DEFAULT; | |
141 | ||
142 | /* Initialize the list of control pages */ | |
143 | INIT_LIST_HEAD(&image->control_pages); | |
144 | ||
145 | /* Initialize the list of destination pages */ | |
146 | INIT_LIST_HEAD(&image->dest_pages); | |
147 | ||
25985edc | 148 | /* Initialize the list of unusable pages */ |
dc009d92 EB |
149 | INIT_LIST_HEAD(&image->unuseable_pages); |
150 | ||
151 | /* Read in the segments */ | |
152 | image->nr_segments = nr_segments; | |
153 | segment_bytes = nr_segments * sizeof(*segments); | |
154 | result = copy_from_user(image->segment, segments, segment_bytes); | |
f65a03f6 DC |
155 | if (result) { |
156 | result = -EFAULT; | |
dc009d92 | 157 | goto out; |
f65a03f6 | 158 | } |
dc009d92 EB |
159 | |
160 | /* | |
161 | * Verify we have good destination addresses. The caller is | |
162 | * responsible for making certain we don't attempt to load | |
163 | * the new image into invalid or reserved areas of RAM. This | |
164 | * just verifies it is an address we can use. | |
165 | * | |
166 | * Since the kernel does everything in page size chunks ensure | |
b595076a | 167 | * the destination addresses are page aligned. Too many |
dc009d92 EB |
168 | * special cases crop of when we don't do this. The most |
169 | * insidious is getting overlapping destination addresses | |
170 | * simply because addresses are changed to page size | |
171 | * granularity. | |
172 | */ | |
173 | result = -EADDRNOTAVAIL; | |
174 | for (i = 0; i < nr_segments; i++) { | |
175 | unsigned long mstart, mend; | |
72414d3f | 176 | |
dc009d92 EB |
177 | mstart = image->segment[i].mem; |
178 | mend = mstart + image->segment[i].memsz; | |
179 | if ((mstart & ~PAGE_MASK) || (mend & ~PAGE_MASK)) | |
180 | goto out; | |
181 | if (mend >= KEXEC_DESTINATION_MEMORY_LIMIT) | |
182 | goto out; | |
183 | } | |
184 | ||
185 | /* Verify our destination addresses do not overlap. | |
186 | * If we alloed overlapping destination addresses | |
187 | * through very weird things can happen with no | |
188 | * easy explanation as one segment stops on another. | |
189 | */ | |
190 | result = -EINVAL; | |
72414d3f | 191 | for (i = 0; i < nr_segments; i++) { |
dc009d92 EB |
192 | unsigned long mstart, mend; |
193 | unsigned long j; | |
72414d3f | 194 | |
dc009d92 EB |
195 | mstart = image->segment[i].mem; |
196 | mend = mstart + image->segment[i].memsz; | |
72414d3f | 197 | for (j = 0; j < i; j++) { |
dc009d92 EB |
198 | unsigned long pstart, pend; |
199 | pstart = image->segment[j].mem; | |
200 | pend = pstart + image->segment[j].memsz; | |
201 | /* Do the segments overlap ? */ | |
202 | if ((mend > pstart) && (mstart < pend)) | |
203 | goto out; | |
204 | } | |
205 | } | |
206 | ||
207 | /* Ensure our buffer sizes are strictly less than | |
208 | * our memory sizes. This should always be the case, | |
209 | * and it is easier to check up front than to be surprised | |
210 | * later on. | |
211 | */ | |
212 | result = -EINVAL; | |
72414d3f | 213 | for (i = 0; i < nr_segments; i++) { |
dc009d92 EB |
214 | if (image->segment[i].bufsz > image->segment[i].memsz) |
215 | goto out; | |
216 | } | |
217 | ||
dc009d92 | 218 | result = 0; |
72414d3f MS |
219 | out: |
220 | if (result == 0) | |
dc009d92 | 221 | *rimage = image; |
72414d3f | 222 | else |
dc009d92 | 223 | kfree(image); |
72414d3f | 224 | |
dc009d92 EB |
225 | return result; |
226 | ||
227 | } | |
228 | ||
229 | static int kimage_normal_alloc(struct kimage **rimage, unsigned long entry, | |
72414d3f MS |
230 | unsigned long nr_segments, |
231 | struct kexec_segment __user *segments) | |
dc009d92 EB |
232 | { |
233 | int result; | |
234 | struct kimage *image; | |
235 | ||
236 | /* Allocate and initialize a controlling structure */ | |
237 | image = NULL; | |
238 | result = do_kimage_alloc(&image, entry, nr_segments, segments); | |
72414d3f | 239 | if (result) |
dc009d92 | 240 | goto out; |
72414d3f | 241 | |
dc009d92 EB |
242 | *rimage = image; |
243 | ||
244 | /* | |
245 | * Find a location for the control code buffer, and add it | |
246 | * the vector of segments so that it's pages will also be | |
247 | * counted as destination pages. | |
248 | */ | |
249 | result = -ENOMEM; | |
250 | image->control_code_page = kimage_alloc_control_pages(image, | |
163f6876 | 251 | get_order(KEXEC_CONTROL_PAGE_SIZE)); |
dc009d92 EB |
252 | if (!image->control_code_page) { |
253 | printk(KERN_ERR "Could not allocate control_code_buffer\n"); | |
254 | goto out; | |
255 | } | |
256 | ||
3ab83521 HY |
257 | image->swap_page = kimage_alloc_control_pages(image, 0); |
258 | if (!image->swap_page) { | |
259 | printk(KERN_ERR "Could not allocate swap buffer\n"); | |
260 | goto out; | |
261 | } | |
262 | ||
dc009d92 EB |
263 | result = 0; |
264 | out: | |
72414d3f | 265 | if (result == 0) |
dc009d92 | 266 | *rimage = image; |
72414d3f | 267 | else |
dc009d92 | 268 | kfree(image); |
72414d3f | 269 | |
dc009d92 EB |
270 | return result; |
271 | } | |
272 | ||
273 | static int kimage_crash_alloc(struct kimage **rimage, unsigned long entry, | |
72414d3f | 274 | unsigned long nr_segments, |
314b6a4d | 275 | struct kexec_segment __user *segments) |
dc009d92 EB |
276 | { |
277 | int result; | |
278 | struct kimage *image; | |
279 | unsigned long i; | |
280 | ||
281 | image = NULL; | |
282 | /* Verify we have a valid entry point */ | |
283 | if ((entry < crashk_res.start) || (entry > crashk_res.end)) { | |
284 | result = -EADDRNOTAVAIL; | |
285 | goto out; | |
286 | } | |
287 | ||
288 | /* Allocate and initialize a controlling structure */ | |
289 | result = do_kimage_alloc(&image, entry, nr_segments, segments); | |
72414d3f | 290 | if (result) |
dc009d92 | 291 | goto out; |
dc009d92 EB |
292 | |
293 | /* Enable the special crash kernel control page | |
294 | * allocation policy. | |
295 | */ | |
296 | image->control_page = crashk_res.start; | |
297 | image->type = KEXEC_TYPE_CRASH; | |
298 | ||
299 | /* | |
300 | * Verify we have good destination addresses. Normally | |
301 | * the caller is responsible for making certain we don't | |
302 | * attempt to load the new image into invalid or reserved | |
303 | * areas of RAM. But crash kernels are preloaded into a | |
304 | * reserved area of ram. We must ensure the addresses | |
305 | * are in the reserved area otherwise preloading the | |
306 | * kernel could corrupt things. | |
307 | */ | |
308 | result = -EADDRNOTAVAIL; | |
309 | for (i = 0; i < nr_segments; i++) { | |
310 | unsigned long mstart, mend; | |
72414d3f | 311 | |
dc009d92 | 312 | mstart = image->segment[i].mem; |
50cccc69 | 313 | mend = mstart + image->segment[i].memsz - 1; |
dc009d92 EB |
314 | /* Ensure we are within the crash kernel limits */ |
315 | if ((mstart < crashk_res.start) || (mend > crashk_res.end)) | |
316 | goto out; | |
317 | } | |
318 | ||
dc009d92 EB |
319 | /* |
320 | * Find a location for the control code buffer, and add | |
321 | * the vector of segments so that it's pages will also be | |
322 | * counted as destination pages. | |
323 | */ | |
324 | result = -ENOMEM; | |
325 | image->control_code_page = kimage_alloc_control_pages(image, | |
163f6876 | 326 | get_order(KEXEC_CONTROL_PAGE_SIZE)); |
dc009d92 EB |
327 | if (!image->control_code_page) { |
328 | printk(KERN_ERR "Could not allocate control_code_buffer\n"); | |
329 | goto out; | |
330 | } | |
331 | ||
332 | result = 0; | |
72414d3f MS |
333 | out: |
334 | if (result == 0) | |
dc009d92 | 335 | *rimage = image; |
72414d3f | 336 | else |
dc009d92 | 337 | kfree(image); |
72414d3f | 338 | |
dc009d92 EB |
339 | return result; |
340 | } | |
341 | ||
72414d3f MS |
342 | static int kimage_is_destination_range(struct kimage *image, |
343 | unsigned long start, | |
344 | unsigned long end) | |
dc009d92 EB |
345 | { |
346 | unsigned long i; | |
347 | ||
348 | for (i = 0; i < image->nr_segments; i++) { | |
349 | unsigned long mstart, mend; | |
72414d3f | 350 | |
dc009d92 | 351 | mstart = image->segment[i].mem; |
72414d3f MS |
352 | mend = mstart + image->segment[i].memsz; |
353 | if ((end > mstart) && (start < mend)) | |
dc009d92 | 354 | return 1; |
dc009d92 | 355 | } |
72414d3f | 356 | |
dc009d92 EB |
357 | return 0; |
358 | } | |
359 | ||
9796fdd8 | 360 | static struct page *kimage_alloc_pages(gfp_t gfp_mask, unsigned int order) |
dc009d92 EB |
361 | { |
362 | struct page *pages; | |
72414d3f | 363 | |
dc009d92 EB |
364 | pages = alloc_pages(gfp_mask, order); |
365 | if (pages) { | |
366 | unsigned int count, i; | |
367 | pages->mapping = NULL; | |
4c21e2f2 | 368 | set_page_private(pages, order); |
dc009d92 | 369 | count = 1 << order; |
72414d3f | 370 | for (i = 0; i < count; i++) |
dc009d92 | 371 | SetPageReserved(pages + i); |
dc009d92 | 372 | } |
72414d3f | 373 | |
dc009d92 EB |
374 | return pages; |
375 | } | |
376 | ||
377 | static void kimage_free_pages(struct page *page) | |
378 | { | |
379 | unsigned int order, count, i; | |
72414d3f | 380 | |
4c21e2f2 | 381 | order = page_private(page); |
dc009d92 | 382 | count = 1 << order; |
72414d3f | 383 | for (i = 0; i < count; i++) |
dc009d92 | 384 | ClearPageReserved(page + i); |
dc009d92 EB |
385 | __free_pages(page, order); |
386 | } | |
387 | ||
388 | static void kimage_free_page_list(struct list_head *list) | |
389 | { | |
390 | struct list_head *pos, *next; | |
72414d3f | 391 | |
dc009d92 EB |
392 | list_for_each_safe(pos, next, list) { |
393 | struct page *page; | |
394 | ||
395 | page = list_entry(pos, struct page, lru); | |
396 | list_del(&page->lru); | |
dc009d92 EB |
397 | kimage_free_pages(page); |
398 | } | |
399 | } | |
400 | ||
72414d3f MS |
401 | static struct page *kimage_alloc_normal_control_pages(struct kimage *image, |
402 | unsigned int order) | |
dc009d92 EB |
403 | { |
404 | /* Control pages are special, they are the intermediaries | |
405 | * that are needed while we copy the rest of the pages | |
406 | * to their final resting place. As such they must | |
407 | * not conflict with either the destination addresses | |
408 | * or memory the kernel is already using. | |
409 | * | |
410 | * The only case where we really need more than one of | |
411 | * these are for architectures where we cannot disable | |
412 | * the MMU and must instead generate an identity mapped | |
413 | * page table for all of the memory. | |
414 | * | |
415 | * At worst this runs in O(N) of the image size. | |
416 | */ | |
417 | struct list_head extra_pages; | |
418 | struct page *pages; | |
419 | unsigned int count; | |
420 | ||
421 | count = 1 << order; | |
422 | INIT_LIST_HEAD(&extra_pages); | |
423 | ||
424 | /* Loop while I can allocate a page and the page allocated | |
425 | * is a destination page. | |
426 | */ | |
427 | do { | |
428 | unsigned long pfn, epfn, addr, eaddr; | |
72414d3f | 429 | |
dc009d92 EB |
430 | pages = kimage_alloc_pages(GFP_KERNEL, order); |
431 | if (!pages) | |
432 | break; | |
433 | pfn = page_to_pfn(pages); | |
434 | epfn = pfn + count; | |
435 | addr = pfn << PAGE_SHIFT; | |
436 | eaddr = epfn << PAGE_SHIFT; | |
437 | if ((epfn >= (KEXEC_CONTROL_MEMORY_LIMIT >> PAGE_SHIFT)) || | |
72414d3f | 438 | kimage_is_destination_range(image, addr, eaddr)) { |
dc009d92 EB |
439 | list_add(&pages->lru, &extra_pages); |
440 | pages = NULL; | |
441 | } | |
72414d3f MS |
442 | } while (!pages); |
443 | ||
dc009d92 EB |
444 | if (pages) { |
445 | /* Remember the allocated page... */ | |
446 | list_add(&pages->lru, &image->control_pages); | |
447 | ||
448 | /* Because the page is already in it's destination | |
449 | * location we will never allocate another page at | |
450 | * that address. Therefore kimage_alloc_pages | |
451 | * will not return it (again) and we don't need | |
452 | * to give it an entry in image->segment[]. | |
453 | */ | |
454 | } | |
455 | /* Deal with the destination pages I have inadvertently allocated. | |
456 | * | |
457 | * Ideally I would convert multi-page allocations into single | |
25985edc | 458 | * page allocations, and add everything to image->dest_pages. |
dc009d92 EB |
459 | * |
460 | * For now it is simpler to just free the pages. | |
461 | */ | |
462 | kimage_free_page_list(&extra_pages); | |
dc009d92 | 463 | |
72414d3f | 464 | return pages; |
dc009d92 EB |
465 | } |
466 | ||
72414d3f MS |
467 | static struct page *kimage_alloc_crash_control_pages(struct kimage *image, |
468 | unsigned int order) | |
dc009d92 EB |
469 | { |
470 | /* Control pages are special, they are the intermediaries | |
471 | * that are needed while we copy the rest of the pages | |
472 | * to their final resting place. As such they must | |
473 | * not conflict with either the destination addresses | |
474 | * or memory the kernel is already using. | |
475 | * | |
476 | * Control pages are also the only pags we must allocate | |
477 | * when loading a crash kernel. All of the other pages | |
478 | * are specified by the segments and we just memcpy | |
479 | * into them directly. | |
480 | * | |
481 | * The only case where we really need more than one of | |
482 | * these are for architectures where we cannot disable | |
483 | * the MMU and must instead generate an identity mapped | |
484 | * page table for all of the memory. | |
485 | * | |
486 | * Given the low demand this implements a very simple | |
487 | * allocator that finds the first hole of the appropriate | |
488 | * size in the reserved memory region, and allocates all | |
489 | * of the memory up to and including the hole. | |
490 | */ | |
491 | unsigned long hole_start, hole_end, size; | |
492 | struct page *pages; | |
72414d3f | 493 | |
dc009d92 EB |
494 | pages = NULL; |
495 | size = (1 << order) << PAGE_SHIFT; | |
496 | hole_start = (image->control_page + (size - 1)) & ~(size - 1); | |
497 | hole_end = hole_start + size - 1; | |
72414d3f | 498 | while (hole_end <= crashk_res.end) { |
dc009d92 | 499 | unsigned long i; |
72414d3f | 500 | |
3d214fae | 501 | if (hole_end > KEXEC_CRASH_CONTROL_MEMORY_LIMIT) |
dc009d92 | 502 | break; |
72414d3f | 503 | if (hole_end > crashk_res.end) |
dc009d92 | 504 | break; |
dc009d92 | 505 | /* See if I overlap any of the segments */ |
72414d3f | 506 | for (i = 0; i < image->nr_segments; i++) { |
dc009d92 | 507 | unsigned long mstart, mend; |
72414d3f | 508 | |
dc009d92 EB |
509 | mstart = image->segment[i].mem; |
510 | mend = mstart + image->segment[i].memsz - 1; | |
511 | if ((hole_end >= mstart) && (hole_start <= mend)) { | |
512 | /* Advance the hole to the end of the segment */ | |
513 | hole_start = (mend + (size - 1)) & ~(size - 1); | |
514 | hole_end = hole_start + size - 1; | |
515 | break; | |
516 | } | |
517 | } | |
518 | /* If I don't overlap any segments I have found my hole! */ | |
519 | if (i == image->nr_segments) { | |
520 | pages = pfn_to_page(hole_start >> PAGE_SHIFT); | |
521 | break; | |
522 | } | |
523 | } | |
72414d3f | 524 | if (pages) |
dc009d92 | 525 | image->control_page = hole_end; |
72414d3f | 526 | |
dc009d92 EB |
527 | return pages; |
528 | } | |
529 | ||
530 | ||
72414d3f MS |
531 | struct page *kimage_alloc_control_pages(struct kimage *image, |
532 | unsigned int order) | |
dc009d92 EB |
533 | { |
534 | struct page *pages = NULL; | |
72414d3f MS |
535 | |
536 | switch (image->type) { | |
dc009d92 EB |
537 | case KEXEC_TYPE_DEFAULT: |
538 | pages = kimage_alloc_normal_control_pages(image, order); | |
539 | break; | |
540 | case KEXEC_TYPE_CRASH: | |
541 | pages = kimage_alloc_crash_control_pages(image, order); | |
542 | break; | |
543 | } | |
72414d3f | 544 | |
dc009d92 EB |
545 | return pages; |
546 | } | |
547 | ||
548 | static int kimage_add_entry(struct kimage *image, kimage_entry_t entry) | |
549 | { | |
72414d3f | 550 | if (*image->entry != 0) |
dc009d92 | 551 | image->entry++; |
72414d3f | 552 | |
dc009d92 EB |
553 | if (image->entry == image->last_entry) { |
554 | kimage_entry_t *ind_page; | |
555 | struct page *page; | |
72414d3f | 556 | |
dc009d92 | 557 | page = kimage_alloc_page(image, GFP_KERNEL, KIMAGE_NO_DEST); |
72414d3f | 558 | if (!page) |
dc009d92 | 559 | return -ENOMEM; |
72414d3f | 560 | |
dc009d92 EB |
561 | ind_page = page_address(page); |
562 | *image->entry = virt_to_phys(ind_page) | IND_INDIRECTION; | |
563 | image->entry = ind_page; | |
72414d3f MS |
564 | image->last_entry = ind_page + |
565 | ((PAGE_SIZE/sizeof(kimage_entry_t)) - 1); | |
dc009d92 EB |
566 | } |
567 | *image->entry = entry; | |
568 | image->entry++; | |
569 | *image->entry = 0; | |
72414d3f | 570 | |
dc009d92 EB |
571 | return 0; |
572 | } | |
573 | ||
72414d3f MS |
574 | static int kimage_set_destination(struct kimage *image, |
575 | unsigned long destination) | |
dc009d92 EB |
576 | { |
577 | int result; | |
578 | ||
579 | destination &= PAGE_MASK; | |
580 | result = kimage_add_entry(image, destination | IND_DESTINATION); | |
72414d3f | 581 | if (result == 0) |
dc009d92 | 582 | image->destination = destination; |
72414d3f | 583 | |
dc009d92 EB |
584 | return result; |
585 | } | |
586 | ||
587 | ||
588 | static int kimage_add_page(struct kimage *image, unsigned long page) | |
589 | { | |
590 | int result; | |
591 | ||
592 | page &= PAGE_MASK; | |
593 | result = kimage_add_entry(image, page | IND_SOURCE); | |
72414d3f | 594 | if (result == 0) |
dc009d92 | 595 | image->destination += PAGE_SIZE; |
72414d3f | 596 | |
dc009d92 EB |
597 | return result; |
598 | } | |
599 | ||
600 | ||
601 | static void kimage_free_extra_pages(struct kimage *image) | |
602 | { | |
603 | /* Walk through and free any extra destination pages I may have */ | |
604 | kimage_free_page_list(&image->dest_pages); | |
605 | ||
25985edc | 606 | /* Walk through and free any unusable pages I have cached */ |
dc009d92 EB |
607 | kimage_free_page_list(&image->unuseable_pages); |
608 | ||
609 | } | |
7fccf032 | 610 | static void kimage_terminate(struct kimage *image) |
dc009d92 | 611 | { |
72414d3f | 612 | if (*image->entry != 0) |
dc009d92 | 613 | image->entry++; |
72414d3f | 614 | |
dc009d92 | 615 | *image->entry = IND_DONE; |
dc009d92 EB |
616 | } |
617 | ||
618 | #define for_each_kimage_entry(image, ptr, entry) \ | |
619 | for (ptr = &image->head; (entry = *ptr) && !(entry & IND_DONE); \ | |
620 | ptr = (entry & IND_INDIRECTION)? \ | |
621 | phys_to_virt((entry & PAGE_MASK)): ptr +1) | |
622 | ||
623 | static void kimage_free_entry(kimage_entry_t entry) | |
624 | { | |
625 | struct page *page; | |
626 | ||
627 | page = pfn_to_page(entry >> PAGE_SHIFT); | |
628 | kimage_free_pages(page); | |
629 | } | |
630 | ||
631 | static void kimage_free(struct kimage *image) | |
632 | { | |
633 | kimage_entry_t *ptr, entry; | |
634 | kimage_entry_t ind = 0; | |
635 | ||
636 | if (!image) | |
637 | return; | |
72414d3f | 638 | |
dc009d92 EB |
639 | kimage_free_extra_pages(image); |
640 | for_each_kimage_entry(image, ptr, entry) { | |
641 | if (entry & IND_INDIRECTION) { | |
642 | /* Free the previous indirection page */ | |
72414d3f | 643 | if (ind & IND_INDIRECTION) |
dc009d92 | 644 | kimage_free_entry(ind); |
dc009d92 EB |
645 | /* Save this indirection page until we are |
646 | * done with it. | |
647 | */ | |
648 | ind = entry; | |
649 | } | |
72414d3f | 650 | else if (entry & IND_SOURCE) |
dc009d92 | 651 | kimage_free_entry(entry); |
dc009d92 EB |
652 | } |
653 | /* Free the final indirection page */ | |
72414d3f | 654 | if (ind & IND_INDIRECTION) |
dc009d92 | 655 | kimage_free_entry(ind); |
dc009d92 EB |
656 | |
657 | /* Handle any machine specific cleanup */ | |
658 | machine_kexec_cleanup(image); | |
659 | ||
660 | /* Free the kexec control pages... */ | |
661 | kimage_free_page_list(&image->control_pages); | |
662 | kfree(image); | |
663 | } | |
664 | ||
72414d3f MS |
665 | static kimage_entry_t *kimage_dst_used(struct kimage *image, |
666 | unsigned long page) | |
dc009d92 EB |
667 | { |
668 | kimage_entry_t *ptr, entry; | |
669 | unsigned long destination = 0; | |
670 | ||
671 | for_each_kimage_entry(image, ptr, entry) { | |
72414d3f | 672 | if (entry & IND_DESTINATION) |
dc009d92 | 673 | destination = entry & PAGE_MASK; |
dc009d92 | 674 | else if (entry & IND_SOURCE) { |
72414d3f | 675 | if (page == destination) |
dc009d92 | 676 | return ptr; |
dc009d92 EB |
677 | destination += PAGE_SIZE; |
678 | } | |
679 | } | |
72414d3f | 680 | |
314b6a4d | 681 | return NULL; |
dc009d92 EB |
682 | } |
683 | ||
72414d3f | 684 | static struct page *kimage_alloc_page(struct kimage *image, |
9796fdd8 | 685 | gfp_t gfp_mask, |
72414d3f | 686 | unsigned long destination) |
dc009d92 EB |
687 | { |
688 | /* | |
689 | * Here we implement safeguards to ensure that a source page | |
690 | * is not copied to its destination page before the data on | |
691 | * the destination page is no longer useful. | |
692 | * | |
693 | * To do this we maintain the invariant that a source page is | |
694 | * either its own destination page, or it is not a | |
695 | * destination page at all. | |
696 | * | |
697 | * That is slightly stronger than required, but the proof | |
698 | * that no problems will not occur is trivial, and the | |
699 | * implementation is simply to verify. | |
700 | * | |
701 | * When allocating all pages normally this algorithm will run | |
702 | * in O(N) time, but in the worst case it will run in O(N^2) | |
703 | * time. If the runtime is a problem the data structures can | |
704 | * be fixed. | |
705 | */ | |
706 | struct page *page; | |
707 | unsigned long addr; | |
708 | ||
709 | /* | |
710 | * Walk through the list of destination pages, and see if I | |
711 | * have a match. | |
712 | */ | |
713 | list_for_each_entry(page, &image->dest_pages, lru) { | |
714 | addr = page_to_pfn(page) << PAGE_SHIFT; | |
715 | if (addr == destination) { | |
716 | list_del(&page->lru); | |
717 | return page; | |
718 | } | |
719 | } | |
720 | page = NULL; | |
721 | while (1) { | |
722 | kimage_entry_t *old; | |
723 | ||
724 | /* Allocate a page, if we run out of memory give up */ | |
725 | page = kimage_alloc_pages(gfp_mask, 0); | |
72414d3f | 726 | if (!page) |
314b6a4d | 727 | return NULL; |
dc009d92 | 728 | /* If the page cannot be used file it away */ |
72414d3f MS |
729 | if (page_to_pfn(page) > |
730 | (KEXEC_SOURCE_MEMORY_LIMIT >> PAGE_SHIFT)) { | |
dc009d92 EB |
731 | list_add(&page->lru, &image->unuseable_pages); |
732 | continue; | |
733 | } | |
734 | addr = page_to_pfn(page) << PAGE_SHIFT; | |
735 | ||
736 | /* If it is the destination page we want use it */ | |
737 | if (addr == destination) | |
738 | break; | |
739 | ||
740 | /* If the page is not a destination page use it */ | |
72414d3f MS |
741 | if (!kimage_is_destination_range(image, addr, |
742 | addr + PAGE_SIZE)) | |
dc009d92 EB |
743 | break; |
744 | ||
745 | /* | |
746 | * I know that the page is someones destination page. | |
747 | * See if there is already a source page for this | |
748 | * destination page. And if so swap the source pages. | |
749 | */ | |
750 | old = kimage_dst_used(image, addr); | |
751 | if (old) { | |
752 | /* If so move it */ | |
753 | unsigned long old_addr; | |
754 | struct page *old_page; | |
755 | ||
756 | old_addr = *old & PAGE_MASK; | |
757 | old_page = pfn_to_page(old_addr >> PAGE_SHIFT); | |
758 | copy_highpage(page, old_page); | |
759 | *old = addr | (*old & ~PAGE_MASK); | |
760 | ||
761 | /* The old page I have found cannot be a | |
f9092f35 JS |
762 | * destination page, so return it if it's |
763 | * gfp_flags honor the ones passed in. | |
dc009d92 | 764 | */ |
f9092f35 JS |
765 | if (!(gfp_mask & __GFP_HIGHMEM) && |
766 | PageHighMem(old_page)) { | |
767 | kimage_free_pages(old_page); | |
768 | continue; | |
769 | } | |
dc009d92 EB |
770 | addr = old_addr; |
771 | page = old_page; | |
772 | break; | |
773 | } | |
774 | else { | |
775 | /* Place the page on the destination list I | |
776 | * will use it later. | |
777 | */ | |
778 | list_add(&page->lru, &image->dest_pages); | |
779 | } | |
780 | } | |
72414d3f | 781 | |
dc009d92 EB |
782 | return page; |
783 | } | |
784 | ||
785 | static int kimage_load_normal_segment(struct kimage *image, | |
72414d3f | 786 | struct kexec_segment *segment) |
dc009d92 EB |
787 | { |
788 | unsigned long maddr; | |
789 | unsigned long ubytes, mbytes; | |
790 | int result; | |
314b6a4d | 791 | unsigned char __user *buf; |
dc009d92 EB |
792 | |
793 | result = 0; | |
794 | buf = segment->buf; | |
795 | ubytes = segment->bufsz; | |
796 | mbytes = segment->memsz; | |
797 | maddr = segment->mem; | |
798 | ||
799 | result = kimage_set_destination(image, maddr); | |
72414d3f | 800 | if (result < 0) |
dc009d92 | 801 | goto out; |
72414d3f MS |
802 | |
803 | while (mbytes) { | |
dc009d92 EB |
804 | struct page *page; |
805 | char *ptr; | |
806 | size_t uchunk, mchunk; | |
72414d3f | 807 | |
dc009d92 | 808 | page = kimage_alloc_page(image, GFP_HIGHUSER, maddr); |
c80544dc | 809 | if (!page) { |
dc009d92 EB |
810 | result = -ENOMEM; |
811 | goto out; | |
812 | } | |
72414d3f MS |
813 | result = kimage_add_page(image, page_to_pfn(page) |
814 | << PAGE_SHIFT); | |
815 | if (result < 0) | |
dc009d92 | 816 | goto out; |
72414d3f | 817 | |
dc009d92 EB |
818 | ptr = kmap(page); |
819 | /* Start with a clear page */ | |
3ecb01df | 820 | clear_page(ptr); |
dc009d92 EB |
821 | ptr += maddr & ~PAGE_MASK; |
822 | mchunk = PAGE_SIZE - (maddr & ~PAGE_MASK); | |
72414d3f | 823 | if (mchunk > mbytes) |
dc009d92 | 824 | mchunk = mbytes; |
72414d3f | 825 | |
dc009d92 | 826 | uchunk = mchunk; |
72414d3f | 827 | if (uchunk > ubytes) |
dc009d92 | 828 | uchunk = ubytes; |
72414d3f | 829 | |
dc009d92 EB |
830 | result = copy_from_user(ptr, buf, uchunk); |
831 | kunmap(page); | |
832 | if (result) { | |
f65a03f6 | 833 | result = -EFAULT; |
dc009d92 EB |
834 | goto out; |
835 | } | |
836 | ubytes -= uchunk; | |
837 | maddr += mchunk; | |
838 | buf += mchunk; | |
839 | mbytes -= mchunk; | |
840 | } | |
72414d3f | 841 | out: |
dc009d92 EB |
842 | return result; |
843 | } | |
844 | ||
845 | static int kimage_load_crash_segment(struct kimage *image, | |
72414d3f | 846 | struct kexec_segment *segment) |
dc009d92 EB |
847 | { |
848 | /* For crash dumps kernels we simply copy the data from | |
849 | * user space to it's destination. | |
850 | * We do things a page at a time for the sake of kmap. | |
851 | */ | |
852 | unsigned long maddr; | |
853 | unsigned long ubytes, mbytes; | |
854 | int result; | |
314b6a4d | 855 | unsigned char __user *buf; |
dc009d92 EB |
856 | |
857 | result = 0; | |
858 | buf = segment->buf; | |
859 | ubytes = segment->bufsz; | |
860 | mbytes = segment->memsz; | |
861 | maddr = segment->mem; | |
72414d3f | 862 | while (mbytes) { |
dc009d92 EB |
863 | struct page *page; |
864 | char *ptr; | |
865 | size_t uchunk, mchunk; | |
72414d3f | 866 | |
dc009d92 | 867 | page = pfn_to_page(maddr >> PAGE_SHIFT); |
c80544dc | 868 | if (!page) { |
dc009d92 EB |
869 | result = -ENOMEM; |
870 | goto out; | |
871 | } | |
872 | ptr = kmap(page); | |
873 | ptr += maddr & ~PAGE_MASK; | |
874 | mchunk = PAGE_SIZE - (maddr & ~PAGE_MASK); | |
72414d3f | 875 | if (mchunk > mbytes) |
dc009d92 | 876 | mchunk = mbytes; |
72414d3f | 877 | |
dc009d92 EB |
878 | uchunk = mchunk; |
879 | if (uchunk > ubytes) { | |
880 | uchunk = ubytes; | |
881 | /* Zero the trailing part of the page */ | |
882 | memset(ptr + uchunk, 0, mchunk - uchunk); | |
883 | } | |
884 | result = copy_from_user(ptr, buf, uchunk); | |
a7956113 | 885 | kexec_flush_icache_page(page); |
dc009d92 EB |
886 | kunmap(page); |
887 | if (result) { | |
f65a03f6 | 888 | result = -EFAULT; |
dc009d92 EB |
889 | goto out; |
890 | } | |
891 | ubytes -= uchunk; | |
892 | maddr += mchunk; | |
893 | buf += mchunk; | |
894 | mbytes -= mchunk; | |
895 | } | |
72414d3f | 896 | out: |
dc009d92 EB |
897 | return result; |
898 | } | |
899 | ||
900 | static int kimage_load_segment(struct kimage *image, | |
72414d3f | 901 | struct kexec_segment *segment) |
dc009d92 EB |
902 | { |
903 | int result = -ENOMEM; | |
72414d3f MS |
904 | |
905 | switch (image->type) { | |
dc009d92 EB |
906 | case KEXEC_TYPE_DEFAULT: |
907 | result = kimage_load_normal_segment(image, segment); | |
908 | break; | |
909 | case KEXEC_TYPE_CRASH: | |
910 | result = kimage_load_crash_segment(image, segment); | |
911 | break; | |
912 | } | |
72414d3f | 913 | |
dc009d92 EB |
914 | return result; |
915 | } | |
916 | ||
917 | /* | |
918 | * Exec Kernel system call: for obvious reasons only root may call it. | |
919 | * | |
920 | * This call breaks up into three pieces. | |
921 | * - A generic part which loads the new kernel from the current | |
922 | * address space, and very carefully places the data in the | |
923 | * allocated pages. | |
924 | * | |
925 | * - A generic part that interacts with the kernel and tells all of | |
926 | * the devices to shut down. Preventing on-going dmas, and placing | |
927 | * the devices in a consistent state so a later kernel can | |
928 | * reinitialize them. | |
929 | * | |
930 | * - A machine specific part that includes the syscall number | |
931 | * and the copies the image to it's final destination. And | |
932 | * jumps into the image at entry. | |
933 | * | |
934 | * kexec does not sync, or unmount filesystems so if you need | |
935 | * that to happen you need to do that yourself. | |
936 | */ | |
c330dda9 JM |
937 | struct kimage *kexec_image; |
938 | struct kimage *kexec_crash_image; | |
8c5a1cf0 AM |
939 | |
940 | static DEFINE_MUTEX(kexec_mutex); | |
dc009d92 | 941 | |
754fe8d2 HC |
942 | SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments, |
943 | struct kexec_segment __user *, segments, unsigned long, flags) | |
dc009d92 EB |
944 | { |
945 | struct kimage **dest_image, *image; | |
dc009d92 EB |
946 | int result; |
947 | ||
948 | /* We only trust the superuser with rebooting the system. */ | |
949 | if (!capable(CAP_SYS_BOOT)) | |
950 | return -EPERM; | |
951 | ||
952 | /* | |
953 | * Verify we have a legal set of flags | |
954 | * This leaves us room for future extensions. | |
955 | */ | |
956 | if ((flags & KEXEC_FLAGS) != (flags & ~KEXEC_ARCH_MASK)) | |
957 | return -EINVAL; | |
958 | ||
959 | /* Verify we are on the appropriate architecture */ | |
960 | if (((flags & KEXEC_ARCH_MASK) != KEXEC_ARCH) && | |
961 | ((flags & KEXEC_ARCH_MASK) != KEXEC_ARCH_DEFAULT)) | |
dc009d92 | 962 | return -EINVAL; |
dc009d92 EB |
963 | |
964 | /* Put an artificial cap on the number | |
965 | * of segments passed to kexec_load. | |
966 | */ | |
967 | if (nr_segments > KEXEC_SEGMENT_MAX) | |
968 | return -EINVAL; | |
969 | ||
970 | image = NULL; | |
971 | result = 0; | |
972 | ||
973 | /* Because we write directly to the reserved memory | |
974 | * region when loading crash kernels we need a mutex here to | |
975 | * prevent multiple crash kernels from attempting to load | |
976 | * simultaneously, and to prevent a crash kernel from loading | |
977 | * over the top of a in use crash kernel. | |
978 | * | |
979 | * KISS: always take the mutex. | |
980 | */ | |
8c5a1cf0 | 981 | if (!mutex_trylock(&kexec_mutex)) |
dc009d92 | 982 | return -EBUSY; |
72414d3f | 983 | |
dc009d92 | 984 | dest_image = &kexec_image; |
72414d3f | 985 | if (flags & KEXEC_ON_CRASH) |
dc009d92 | 986 | dest_image = &kexec_crash_image; |
dc009d92 EB |
987 | if (nr_segments > 0) { |
988 | unsigned long i; | |
72414d3f | 989 | |
dc009d92 | 990 | /* Loading another kernel to reboot into */ |
72414d3f MS |
991 | if ((flags & KEXEC_ON_CRASH) == 0) |
992 | result = kimage_normal_alloc(&image, entry, | |
993 | nr_segments, segments); | |
dc009d92 EB |
994 | /* Loading another kernel to switch to if this one crashes */ |
995 | else if (flags & KEXEC_ON_CRASH) { | |
996 | /* Free any current crash dump kernel before | |
997 | * we corrupt it. | |
998 | */ | |
999 | kimage_free(xchg(&kexec_crash_image, NULL)); | |
72414d3f MS |
1000 | result = kimage_crash_alloc(&image, entry, |
1001 | nr_segments, segments); | |
dc009d92 | 1002 | } |
72414d3f | 1003 | if (result) |
dc009d92 | 1004 | goto out; |
72414d3f | 1005 | |
3ab83521 HY |
1006 | if (flags & KEXEC_PRESERVE_CONTEXT) |
1007 | image->preserve_context = 1; | |
dc009d92 | 1008 | result = machine_kexec_prepare(image); |
72414d3f | 1009 | if (result) |
dc009d92 | 1010 | goto out; |
72414d3f MS |
1011 | |
1012 | for (i = 0; i < nr_segments; i++) { | |
dc009d92 | 1013 | result = kimage_load_segment(image, &image->segment[i]); |
72414d3f | 1014 | if (result) |
dc009d92 | 1015 | goto out; |
dc009d92 | 1016 | } |
7fccf032 | 1017 | kimage_terminate(image); |
dc009d92 EB |
1018 | } |
1019 | /* Install the new kernel, and Uninstall the old */ | |
1020 | image = xchg(dest_image, image); | |
1021 | ||
72414d3f | 1022 | out: |
8c5a1cf0 | 1023 | mutex_unlock(&kexec_mutex); |
dc009d92 | 1024 | kimage_free(image); |
72414d3f | 1025 | |
dc009d92 EB |
1026 | return result; |
1027 | } | |
1028 | ||
1029 | #ifdef CONFIG_COMPAT | |
1030 | asmlinkage long compat_sys_kexec_load(unsigned long entry, | |
72414d3f MS |
1031 | unsigned long nr_segments, |
1032 | struct compat_kexec_segment __user *segments, | |
1033 | unsigned long flags) | |
dc009d92 EB |
1034 | { |
1035 | struct compat_kexec_segment in; | |
1036 | struct kexec_segment out, __user *ksegments; | |
1037 | unsigned long i, result; | |
1038 | ||
1039 | /* Don't allow clients that don't understand the native | |
1040 | * architecture to do anything. | |
1041 | */ | |
72414d3f | 1042 | if ((flags & KEXEC_ARCH_MASK) == KEXEC_ARCH_DEFAULT) |
dc009d92 | 1043 | return -EINVAL; |
dc009d92 | 1044 | |
72414d3f | 1045 | if (nr_segments > KEXEC_SEGMENT_MAX) |
dc009d92 | 1046 | return -EINVAL; |
dc009d92 EB |
1047 | |
1048 | ksegments = compat_alloc_user_space(nr_segments * sizeof(out)); | |
1049 | for (i=0; i < nr_segments; i++) { | |
1050 | result = copy_from_user(&in, &segments[i], sizeof(in)); | |
72414d3f | 1051 | if (result) |
dc009d92 | 1052 | return -EFAULT; |
dc009d92 EB |
1053 | |
1054 | out.buf = compat_ptr(in.buf); | |
1055 | out.bufsz = in.bufsz; | |
1056 | out.mem = in.mem; | |
1057 | out.memsz = in.memsz; | |
1058 | ||
1059 | result = copy_to_user(&ksegments[i], &out, sizeof(out)); | |
72414d3f | 1060 | if (result) |
dc009d92 | 1061 | return -EFAULT; |
dc009d92 EB |
1062 | } |
1063 | ||
1064 | return sys_kexec_load(entry, nr_segments, ksegments, flags); | |
1065 | } | |
1066 | #endif | |
1067 | ||
6e274d14 | 1068 | void crash_kexec(struct pt_regs *regs) |
dc009d92 | 1069 | { |
8c5a1cf0 | 1070 | /* Take the kexec_mutex here to prevent sys_kexec_load |
dc009d92 EB |
1071 | * running on one cpu from replacing the crash kernel |
1072 | * we are using after a panic on a different cpu. | |
1073 | * | |
1074 | * If the crash kernel was not located in a fixed area | |
1075 | * of memory the xchg(&kexec_crash_image) would be | |
1076 | * sufficient. But since I reuse the memory... | |
1077 | */ | |
8c5a1cf0 | 1078 | if (mutex_trylock(&kexec_mutex)) { |
c0ce7d08 | 1079 | if (kexec_crash_image) { |
e996e581 | 1080 | struct pt_regs fixed_regs; |
0f4bd46e KM |
1081 | |
1082 | kmsg_dump(KMSG_DUMP_KEXEC); | |
1083 | ||
e996e581 | 1084 | crash_setup_regs(&fixed_regs, regs); |
fd59d231 | 1085 | crash_save_vmcoreinfo(); |
e996e581 | 1086 | machine_crash_shutdown(&fixed_regs); |
c0ce7d08 | 1087 | machine_kexec(kexec_crash_image); |
dc009d92 | 1088 | } |
8c5a1cf0 | 1089 | mutex_unlock(&kexec_mutex); |
dc009d92 EB |
1090 | } |
1091 | } | |
cc571658 | 1092 | |
06a7f711 AW |
1093 | size_t crash_get_memory_size(void) |
1094 | { | |
e05bd336 | 1095 | size_t size = 0; |
06a7f711 | 1096 | mutex_lock(&kexec_mutex); |
e05bd336 | 1097 | if (crashk_res.end != crashk_res.start) |
28f65c11 | 1098 | size = resource_size(&crashk_res); |
06a7f711 AW |
1099 | mutex_unlock(&kexec_mutex); |
1100 | return size; | |
1101 | } | |
1102 | ||
c0bb9e45 AB |
1103 | void __weak crash_free_reserved_phys_range(unsigned long begin, |
1104 | unsigned long end) | |
06a7f711 AW |
1105 | { |
1106 | unsigned long addr; | |
1107 | ||
1108 | for (addr = begin; addr < end; addr += PAGE_SIZE) { | |
1109 | ClearPageReserved(pfn_to_page(addr >> PAGE_SHIFT)); | |
1110 | init_page_count(pfn_to_page(addr >> PAGE_SHIFT)); | |
1111 | free_page((unsigned long)__va(addr)); | |
1112 | totalram_pages++; | |
1113 | } | |
1114 | } | |
1115 | ||
1116 | int crash_shrink_memory(unsigned long new_size) | |
1117 | { | |
1118 | int ret = 0; | |
1119 | unsigned long start, end; | |
1120 | ||
1121 | mutex_lock(&kexec_mutex); | |
1122 | ||
1123 | if (kexec_crash_image) { | |
1124 | ret = -ENOENT; | |
1125 | goto unlock; | |
1126 | } | |
1127 | start = crashk_res.start; | |
1128 | end = crashk_res.end; | |
1129 | ||
1130 | if (new_size >= end - start + 1) { | |
1131 | ret = -EINVAL; | |
1132 | if (new_size == end - start + 1) | |
1133 | ret = 0; | |
1134 | goto unlock; | |
1135 | } | |
1136 | ||
1137 | start = roundup(start, PAGE_SIZE); | |
1138 | end = roundup(start + new_size, PAGE_SIZE); | |
1139 | ||
c0bb9e45 | 1140 | crash_free_reserved_phys_range(end, crashk_res.end); |
06a7f711 | 1141 | |
e05bd336 | 1142 | if ((start == end) && (crashk_res.parent != NULL)) |
06a7f711 | 1143 | release_resource(&crashk_res); |
475f9aa6 | 1144 | crashk_res.end = end - 1; |
06a7f711 AW |
1145 | |
1146 | unlock: | |
1147 | mutex_unlock(&kexec_mutex); | |
1148 | return ret; | |
1149 | } | |
1150 | ||
85916f81 MD |
1151 | static u32 *append_elf_note(u32 *buf, char *name, unsigned type, void *data, |
1152 | size_t data_len) | |
1153 | { | |
1154 | struct elf_note note; | |
1155 | ||
1156 | note.n_namesz = strlen(name) + 1; | |
1157 | note.n_descsz = data_len; | |
1158 | note.n_type = type; | |
1159 | memcpy(buf, ¬e, sizeof(note)); | |
1160 | buf += (sizeof(note) + 3)/4; | |
1161 | memcpy(buf, name, note.n_namesz); | |
1162 | buf += (note.n_namesz + 3)/4; | |
1163 | memcpy(buf, data, note.n_descsz); | |
1164 | buf += (note.n_descsz + 3)/4; | |
1165 | ||
1166 | return buf; | |
1167 | } | |
1168 | ||
1169 | static void final_note(u32 *buf) | |
1170 | { | |
1171 | struct elf_note note; | |
1172 | ||
1173 | note.n_namesz = 0; | |
1174 | note.n_descsz = 0; | |
1175 | note.n_type = 0; | |
1176 | memcpy(buf, ¬e, sizeof(note)); | |
1177 | } | |
1178 | ||
1179 | void crash_save_cpu(struct pt_regs *regs, int cpu) | |
1180 | { | |
1181 | struct elf_prstatus prstatus; | |
1182 | u32 *buf; | |
1183 | ||
4f4b6c1a | 1184 | if ((cpu < 0) || (cpu >= nr_cpu_ids)) |
85916f81 MD |
1185 | return; |
1186 | ||
1187 | /* Using ELF notes here is opportunistic. | |
1188 | * I need a well defined structure format | |
1189 | * for the data I pass, and I need tags | |
1190 | * on the data to indicate what information I have | |
1191 | * squirrelled away. ELF notes happen to provide | |
1192 | * all of that, so there is no need to invent something new. | |
1193 | */ | |
1194 | buf = (u32*)per_cpu_ptr(crash_notes, cpu); | |
1195 | if (!buf) | |
1196 | return; | |
1197 | memset(&prstatus, 0, sizeof(prstatus)); | |
1198 | prstatus.pr_pid = current->pid; | |
6cd61c0b | 1199 | elf_core_copy_kernel_regs(&prstatus.pr_reg, regs); |
6672f76a SH |
1200 | buf = append_elf_note(buf, KEXEC_CORE_NOTE_NAME, NT_PRSTATUS, |
1201 | &prstatus, sizeof(prstatus)); | |
85916f81 MD |
1202 | final_note(buf); |
1203 | } | |
1204 | ||
cc571658 VG |
1205 | static int __init crash_notes_memory_init(void) |
1206 | { | |
1207 | /* Allocate memory for saving cpu registers. */ | |
1208 | crash_notes = alloc_percpu(note_buf_t); | |
1209 | if (!crash_notes) { | |
1210 | printk("Kexec: Memory allocation for saving cpu register" | |
1211 | " states failed\n"); | |
1212 | return -ENOMEM; | |
1213 | } | |
1214 | return 0; | |
1215 | } | |
1216 | module_init(crash_notes_memory_init) | |
fd59d231 | 1217 | |
cba63c30 BW |
1218 | |
1219 | /* | |
1220 | * parsing the "crashkernel" commandline | |
1221 | * | |
1222 | * this code is intended to be called from architecture specific code | |
1223 | */ | |
1224 | ||
1225 | ||
1226 | /* | |
1227 | * This function parses command lines in the format | |
1228 | * | |
1229 | * crashkernel=ramsize-range:size[,...][@offset] | |
1230 | * | |
1231 | * The function returns 0 on success and -EINVAL on failure. | |
1232 | */ | |
1233 | static int __init parse_crashkernel_mem(char *cmdline, | |
1234 | unsigned long long system_ram, | |
1235 | unsigned long long *crash_size, | |
1236 | unsigned long long *crash_base) | |
1237 | { | |
1238 | char *cur = cmdline, *tmp; | |
1239 | ||
1240 | /* for each entry of the comma-separated list */ | |
1241 | do { | |
1242 | unsigned long long start, end = ULLONG_MAX, size; | |
1243 | ||
1244 | /* get the start of the range */ | |
1245 | start = memparse(cur, &tmp); | |
1246 | if (cur == tmp) { | |
1247 | pr_warning("crashkernel: Memory value expected\n"); | |
1248 | return -EINVAL; | |
1249 | } | |
1250 | cur = tmp; | |
1251 | if (*cur != '-') { | |
1252 | pr_warning("crashkernel: '-' expected\n"); | |
1253 | return -EINVAL; | |
1254 | } | |
1255 | cur++; | |
1256 | ||
1257 | /* if no ':' is here, than we read the end */ | |
1258 | if (*cur != ':') { | |
1259 | end = memparse(cur, &tmp); | |
1260 | if (cur == tmp) { | |
1261 | pr_warning("crashkernel: Memory " | |
1262 | "value expected\n"); | |
1263 | return -EINVAL; | |
1264 | } | |
1265 | cur = tmp; | |
1266 | if (end <= start) { | |
1267 | pr_warning("crashkernel: end <= start\n"); | |
1268 | return -EINVAL; | |
1269 | } | |
1270 | } | |
1271 | ||
1272 | if (*cur != ':') { | |
1273 | pr_warning("crashkernel: ':' expected\n"); | |
1274 | return -EINVAL; | |
1275 | } | |
1276 | cur++; | |
1277 | ||
1278 | size = memparse(cur, &tmp); | |
1279 | if (cur == tmp) { | |
1280 | pr_warning("Memory value expected\n"); | |
1281 | return -EINVAL; | |
1282 | } | |
1283 | cur = tmp; | |
1284 | if (size >= system_ram) { | |
1285 | pr_warning("crashkernel: invalid size\n"); | |
1286 | return -EINVAL; | |
1287 | } | |
1288 | ||
1289 | /* match ? */ | |
be089d79 | 1290 | if (system_ram >= start && system_ram < end) { |
cba63c30 BW |
1291 | *crash_size = size; |
1292 | break; | |
1293 | } | |
1294 | } while (*cur++ == ','); | |
1295 | ||
1296 | if (*crash_size > 0) { | |
11c7da4b | 1297 | while (*cur && *cur != ' ' && *cur != '@') |
cba63c30 BW |
1298 | cur++; |
1299 | if (*cur == '@') { | |
1300 | cur++; | |
1301 | *crash_base = memparse(cur, &tmp); | |
1302 | if (cur == tmp) { | |
1303 | pr_warning("Memory value expected " | |
1304 | "after '@'\n"); | |
1305 | return -EINVAL; | |
1306 | } | |
1307 | } | |
1308 | } | |
1309 | ||
1310 | return 0; | |
1311 | } | |
1312 | ||
1313 | /* | |
1314 | * That function parses "simple" (old) crashkernel command lines like | |
1315 | * | |
1316 | * crashkernel=size[@offset] | |
1317 | * | |
1318 | * It returns 0 on success and -EINVAL on failure. | |
1319 | */ | |
1320 | static int __init parse_crashkernel_simple(char *cmdline, | |
1321 | unsigned long long *crash_size, | |
1322 | unsigned long long *crash_base) | |
1323 | { | |
1324 | char *cur = cmdline; | |
1325 | ||
1326 | *crash_size = memparse(cmdline, &cur); | |
1327 | if (cmdline == cur) { | |
1328 | pr_warning("crashkernel: memory value expected\n"); | |
1329 | return -EINVAL; | |
1330 | } | |
1331 | ||
1332 | if (*cur == '@') | |
1333 | *crash_base = memparse(cur+1, &cur); | |
1334 | ||
1335 | return 0; | |
1336 | } | |
1337 | ||
1338 | /* | |
1339 | * That function is the entry point for command line parsing and should be | |
1340 | * called from the arch-specific code. | |
1341 | */ | |
1342 | int __init parse_crashkernel(char *cmdline, | |
1343 | unsigned long long system_ram, | |
1344 | unsigned long long *crash_size, | |
1345 | unsigned long long *crash_base) | |
1346 | { | |
1347 | char *p = cmdline, *ck_cmdline = NULL; | |
1348 | char *first_colon, *first_space; | |
1349 | ||
1350 | BUG_ON(!crash_size || !crash_base); | |
1351 | *crash_size = 0; | |
1352 | *crash_base = 0; | |
1353 | ||
1354 | /* find crashkernel and use the last one if there are more */ | |
1355 | p = strstr(p, "crashkernel="); | |
1356 | while (p) { | |
1357 | ck_cmdline = p; | |
1358 | p = strstr(p+1, "crashkernel="); | |
1359 | } | |
1360 | ||
1361 | if (!ck_cmdline) | |
1362 | return -EINVAL; | |
1363 | ||
1364 | ck_cmdline += 12; /* strlen("crashkernel=") */ | |
1365 | ||
1366 | /* | |
1367 | * if the commandline contains a ':', then that's the extended | |
1368 | * syntax -- if not, it must be the classic syntax | |
1369 | */ | |
1370 | first_colon = strchr(ck_cmdline, ':'); | |
1371 | first_space = strchr(ck_cmdline, ' '); | |
1372 | if (first_colon && (!first_space || first_colon < first_space)) | |
1373 | return parse_crashkernel_mem(ck_cmdline, system_ram, | |
1374 | crash_size, crash_base); | |
1375 | else | |
1376 | return parse_crashkernel_simple(ck_cmdline, crash_size, | |
1377 | crash_base); | |
1378 | ||
1379 | return 0; | |
1380 | } | |
1381 | ||
1382 | ||
1383 | ||
fd59d231 KO |
1384 | void crash_save_vmcoreinfo(void) |
1385 | { | |
1386 | u32 *buf; | |
1387 | ||
1388 | if (!vmcoreinfo_size) | |
1389 | return; | |
1390 | ||
d768281e | 1391 | vmcoreinfo_append_str("CRASHTIME=%ld", get_seconds()); |
fd59d231 KO |
1392 | |
1393 | buf = (u32 *)vmcoreinfo_note; | |
1394 | ||
1395 | buf = append_elf_note(buf, VMCOREINFO_NOTE_NAME, 0, vmcoreinfo_data, | |
1396 | vmcoreinfo_size); | |
1397 | ||
1398 | final_note(buf); | |
1399 | } | |
1400 | ||
1401 | void vmcoreinfo_append_str(const char *fmt, ...) | |
1402 | { | |
1403 | va_list args; | |
1404 | char buf[0x50]; | |
1405 | int r; | |
1406 | ||
1407 | va_start(args, fmt); | |
1408 | r = vsnprintf(buf, sizeof(buf), fmt, args); | |
1409 | va_end(args); | |
1410 | ||
1411 | if (r + vmcoreinfo_size > vmcoreinfo_max_size) | |
1412 | r = vmcoreinfo_max_size - vmcoreinfo_size; | |
1413 | ||
1414 | memcpy(&vmcoreinfo_data[vmcoreinfo_size], buf, r); | |
1415 | ||
1416 | vmcoreinfo_size += r; | |
1417 | } | |
1418 | ||
1419 | /* | |
1420 | * provide an empty default implementation here -- architecture | |
1421 | * code may override this | |
1422 | */ | |
1423 | void __attribute__ ((weak)) arch_crash_save_vmcoreinfo(void) | |
1424 | {} | |
1425 | ||
1426 | unsigned long __attribute__ ((weak)) paddr_vmcoreinfo_note(void) | |
1427 | { | |
1428 | return __pa((unsigned long)(char *)&vmcoreinfo_note); | |
1429 | } | |
1430 | ||
1431 | static int __init crash_save_vmcoreinfo_init(void) | |
1432 | { | |
bba1f603 KO |
1433 | VMCOREINFO_OSRELEASE(init_uts_ns.name.release); |
1434 | VMCOREINFO_PAGESIZE(PAGE_SIZE); | |
fd59d231 | 1435 | |
bcbba6c1 KO |
1436 | VMCOREINFO_SYMBOL(init_uts_ns); |
1437 | VMCOREINFO_SYMBOL(node_online_map); | |
1438 | VMCOREINFO_SYMBOL(swapper_pg_dir); | |
1439 | VMCOREINFO_SYMBOL(_stext); | |
acd99dbf | 1440 | VMCOREINFO_SYMBOL(vmlist); |
fd59d231 KO |
1441 | |
1442 | #ifndef CONFIG_NEED_MULTIPLE_NODES | |
bcbba6c1 KO |
1443 | VMCOREINFO_SYMBOL(mem_map); |
1444 | VMCOREINFO_SYMBOL(contig_page_data); | |
fd59d231 KO |
1445 | #endif |
1446 | #ifdef CONFIG_SPARSEMEM | |
bcbba6c1 KO |
1447 | VMCOREINFO_SYMBOL(mem_section); |
1448 | VMCOREINFO_LENGTH(mem_section, NR_SECTION_ROOTS); | |
c76f860c | 1449 | VMCOREINFO_STRUCT_SIZE(mem_section); |
bcbba6c1 | 1450 | VMCOREINFO_OFFSET(mem_section, section_mem_map); |
fd59d231 | 1451 | #endif |
c76f860c KO |
1452 | VMCOREINFO_STRUCT_SIZE(page); |
1453 | VMCOREINFO_STRUCT_SIZE(pglist_data); | |
1454 | VMCOREINFO_STRUCT_SIZE(zone); | |
1455 | VMCOREINFO_STRUCT_SIZE(free_area); | |
1456 | VMCOREINFO_STRUCT_SIZE(list_head); | |
1457 | VMCOREINFO_SIZE(nodemask_t); | |
bcbba6c1 KO |
1458 | VMCOREINFO_OFFSET(page, flags); |
1459 | VMCOREINFO_OFFSET(page, _count); | |
1460 | VMCOREINFO_OFFSET(page, mapping); | |
1461 | VMCOREINFO_OFFSET(page, lru); | |
1462 | VMCOREINFO_OFFSET(pglist_data, node_zones); | |
1463 | VMCOREINFO_OFFSET(pglist_data, nr_zones); | |
fd59d231 | 1464 | #ifdef CONFIG_FLAT_NODE_MEM_MAP |
bcbba6c1 | 1465 | VMCOREINFO_OFFSET(pglist_data, node_mem_map); |
fd59d231 | 1466 | #endif |
bcbba6c1 KO |
1467 | VMCOREINFO_OFFSET(pglist_data, node_start_pfn); |
1468 | VMCOREINFO_OFFSET(pglist_data, node_spanned_pages); | |
1469 | VMCOREINFO_OFFSET(pglist_data, node_id); | |
1470 | VMCOREINFO_OFFSET(zone, free_area); | |
1471 | VMCOREINFO_OFFSET(zone, vm_stat); | |
1472 | VMCOREINFO_OFFSET(zone, spanned_pages); | |
1473 | VMCOREINFO_OFFSET(free_area, free_list); | |
1474 | VMCOREINFO_OFFSET(list_head, next); | |
1475 | VMCOREINFO_OFFSET(list_head, prev); | |
acd99dbf | 1476 | VMCOREINFO_OFFSET(vm_struct, addr); |
bcbba6c1 | 1477 | VMCOREINFO_LENGTH(zone.free_area, MAX_ORDER); |
04d491ab | 1478 | log_buf_kexec_setup(); |
83a08e7c | 1479 | VMCOREINFO_LENGTH(free_area.free_list, MIGRATE_TYPES); |
bcbba6c1 | 1480 | VMCOREINFO_NUMBER(NR_FREE_PAGES); |
122c7a59 KO |
1481 | VMCOREINFO_NUMBER(PG_lru); |
1482 | VMCOREINFO_NUMBER(PG_private); | |
1483 | VMCOREINFO_NUMBER(PG_swapcache); | |
fd59d231 KO |
1484 | |
1485 | arch_crash_save_vmcoreinfo(); | |
1486 | ||
1487 | return 0; | |
1488 | } | |
1489 | ||
1490 | module_init(crash_save_vmcoreinfo_init) | |
3ab83521 | 1491 | |
7ade3fcc HY |
1492 | /* |
1493 | * Move into place and start executing a preloaded standalone | |
1494 | * executable. If nothing was preloaded return an error. | |
3ab83521 HY |
1495 | */ |
1496 | int kernel_kexec(void) | |
1497 | { | |
1498 | int error = 0; | |
1499 | ||
8c5a1cf0 | 1500 | if (!mutex_trylock(&kexec_mutex)) |
3ab83521 HY |
1501 | return -EBUSY; |
1502 | if (!kexec_image) { | |
1503 | error = -EINVAL; | |
1504 | goto Unlock; | |
1505 | } | |
1506 | ||
3ab83521 | 1507 | #ifdef CONFIG_KEXEC_JUMP |
7ade3fcc | 1508 | if (kexec_image->preserve_context) { |
89081d17 HY |
1509 | mutex_lock(&pm_mutex); |
1510 | pm_prepare_console(); | |
1511 | error = freeze_processes(); | |
1512 | if (error) { | |
1513 | error = -EBUSY; | |
1514 | goto Restore_console; | |
1515 | } | |
1516 | suspend_console(); | |
d1616302 | 1517 | error = dpm_suspend_start(PMSG_FREEZE); |
89081d17 HY |
1518 | if (error) |
1519 | goto Resume_console; | |
d1616302 AS |
1520 | /* At this point, dpm_suspend_start() has been called, |
1521 | * but *not* dpm_suspend_noirq(). We *must* call | |
1522 | * dpm_suspend_noirq() now. Otherwise, drivers for | |
89081d17 HY |
1523 | * some devices (e.g. interrupt controllers) become |
1524 | * desynchronized with the actual state of the | |
1525 | * hardware at resume time, and evil weirdness ensues. | |
1526 | */ | |
d1616302 | 1527 | error = dpm_suspend_noirq(PMSG_FREEZE); |
89081d17 | 1528 | if (error) |
749b0afc RW |
1529 | goto Resume_devices; |
1530 | error = disable_nonboot_cpus(); | |
1531 | if (error) | |
1532 | goto Enable_cpus; | |
2ed8d2b3 | 1533 | local_irq_disable(); |
2e711c04 | 1534 | error = syscore_suspend(); |
770824bd | 1535 | if (error) |
749b0afc | 1536 | goto Enable_irqs; |
7ade3fcc | 1537 | } else |
3ab83521 | 1538 | #endif |
7ade3fcc | 1539 | { |
ca195b7f | 1540 | kernel_restart_prepare(NULL); |
3ab83521 HY |
1541 | printk(KERN_EMERG "Starting new kernel\n"); |
1542 | machine_shutdown(); | |
1543 | } | |
1544 | ||
1545 | machine_kexec(kexec_image); | |
1546 | ||
3ab83521 | 1547 | #ifdef CONFIG_KEXEC_JUMP |
7ade3fcc | 1548 | if (kexec_image->preserve_context) { |
19234c08 | 1549 | syscore_resume(); |
749b0afc | 1550 | Enable_irqs: |
3ab83521 | 1551 | local_irq_enable(); |
749b0afc | 1552 | Enable_cpus: |
89081d17 | 1553 | enable_nonboot_cpus(); |
d1616302 | 1554 | dpm_resume_noirq(PMSG_RESTORE); |
89081d17 | 1555 | Resume_devices: |
d1616302 | 1556 | dpm_resume_end(PMSG_RESTORE); |
89081d17 HY |
1557 | Resume_console: |
1558 | resume_console(); | |
1559 | thaw_processes(); | |
1560 | Restore_console: | |
1561 | pm_restore_console(); | |
1562 | mutex_unlock(&pm_mutex); | |
3ab83521 | 1563 | } |
7ade3fcc | 1564 | #endif |
3ab83521 HY |
1565 | |
1566 | Unlock: | |
8c5a1cf0 | 1567 | mutex_unlock(&kexec_mutex); |
3ab83521 HY |
1568 | return error; |
1569 | } |