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1 | // SPDX-License-Identifier: GPL-2.0-only | |
2 | /* | |
3 | * kexec: kexec_file_load system call | |
4 | * | |
5 | * Copyright (C) 2014 Red Hat Inc. | |
6 | * Authors: | |
7 | * Vivek Goyal <vgoyal@redhat.com> | |
8 | */ | |
9 | ||
10 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt | |
11 | ||
12 | #include <linux/capability.h> | |
13 | #include <linux/mm.h> | |
14 | #include <linux/file.h> | |
15 | #include <linux/slab.h> | |
16 | #include <linux/kexec.h> | |
17 | #include <linux/memblock.h> | |
18 | #include <linux/mutex.h> | |
19 | #include <linux/list.h> | |
20 | #include <linux/fs.h> | |
21 | #include <linux/ima.h> | |
22 | #include <crypto/hash.h> | |
23 | #include <crypto/sha.h> | |
24 | #include <linux/elf.h> | |
25 | #include <linux/elfcore.h> | |
26 | #include <linux/kernel.h> | |
27 | #include <linux/syscalls.h> | |
28 | #include <linux/vmalloc.h> | |
29 | #include "kexec_internal.h" | |
30 | ||
31 | static int kexec_calculate_store_digests(struct kimage *image); | |
32 | ||
33 | /* | |
34 | * Currently this is the only default function that is exported as some | |
35 | * architectures need it to do additional handlings. | |
36 | * In the future, other default functions may be exported too if required. | |
37 | */ | |
38 | int kexec_image_probe_default(struct kimage *image, void *buf, | |
39 | unsigned long buf_len) | |
40 | { | |
41 | const struct kexec_file_ops * const *fops; | |
42 | int ret = -ENOEXEC; | |
43 | ||
44 | for (fops = &kexec_file_loaders[0]; *fops && (*fops)->probe; ++fops) { | |
45 | ret = (*fops)->probe(buf, buf_len); | |
46 | if (!ret) { | |
47 | image->fops = *fops; | |
48 | return ret; | |
49 | } | |
50 | } | |
51 | ||
52 | return ret; | |
53 | } | |
54 | ||
55 | /* Architectures can provide this probe function */ | |
56 | int __weak arch_kexec_kernel_image_probe(struct kimage *image, void *buf, | |
57 | unsigned long buf_len) | |
58 | { | |
59 | return kexec_image_probe_default(image, buf, buf_len); | |
60 | } | |
61 | ||
62 | static void *kexec_image_load_default(struct kimage *image) | |
63 | { | |
64 | if (!image->fops || !image->fops->load) | |
65 | return ERR_PTR(-ENOEXEC); | |
66 | ||
67 | return image->fops->load(image, image->kernel_buf, | |
68 | image->kernel_buf_len, image->initrd_buf, | |
69 | image->initrd_buf_len, image->cmdline_buf, | |
70 | image->cmdline_buf_len); | |
71 | } | |
72 | ||
73 | void * __weak arch_kexec_kernel_image_load(struct kimage *image) | |
74 | { | |
75 | return kexec_image_load_default(image); | |
76 | } | |
77 | ||
78 | int kexec_image_post_load_cleanup_default(struct kimage *image) | |
79 | { | |
80 | if (!image->fops || !image->fops->cleanup) | |
81 | return 0; | |
82 | ||
83 | return image->fops->cleanup(image->image_loader_data); | |
84 | } | |
85 | ||
86 | int __weak arch_kimage_file_post_load_cleanup(struct kimage *image) | |
87 | { | |
88 | return kexec_image_post_load_cleanup_default(image); | |
89 | } | |
90 | ||
91 | #ifdef CONFIG_KEXEC_SIG | |
92 | static int kexec_image_verify_sig_default(struct kimage *image, void *buf, | |
93 | unsigned long buf_len) | |
94 | { | |
95 | if (!image->fops || !image->fops->verify_sig) { | |
96 | pr_debug("kernel loader does not support signature verification.\n"); | |
97 | return -EKEYREJECTED; | |
98 | } | |
99 | ||
100 | return image->fops->verify_sig(buf, buf_len); | |
101 | } | |
102 | ||
103 | int __weak arch_kexec_kernel_verify_sig(struct kimage *image, void *buf, | |
104 | unsigned long buf_len) | |
105 | { | |
106 | return kexec_image_verify_sig_default(image, buf, buf_len); | |
107 | } | |
108 | #endif | |
109 | ||
110 | /* | |
111 | * arch_kexec_apply_relocations_add - apply relocations of type RELA | |
112 | * @pi: Purgatory to be relocated. | |
113 | * @section: Section relocations applying to. | |
114 | * @relsec: Section containing RELAs. | |
115 | * @symtab: Corresponding symtab. | |
116 | * | |
117 | * Return: 0 on success, negative errno on error. | |
118 | */ | |
119 | int __weak | |
120 | arch_kexec_apply_relocations_add(struct purgatory_info *pi, Elf_Shdr *section, | |
121 | const Elf_Shdr *relsec, const Elf_Shdr *symtab) | |
122 | { | |
123 | pr_err("RELA relocation unsupported.\n"); | |
124 | return -ENOEXEC; | |
125 | } | |
126 | ||
127 | /* | |
128 | * arch_kexec_apply_relocations - apply relocations of type REL | |
129 | * @pi: Purgatory to be relocated. | |
130 | * @section: Section relocations applying to. | |
131 | * @relsec: Section containing RELs. | |
132 | * @symtab: Corresponding symtab. | |
133 | * | |
134 | * Return: 0 on success, negative errno on error. | |
135 | */ | |
136 | int __weak | |
137 | arch_kexec_apply_relocations(struct purgatory_info *pi, Elf_Shdr *section, | |
138 | const Elf_Shdr *relsec, const Elf_Shdr *symtab) | |
139 | { | |
140 | pr_err("REL relocation unsupported.\n"); | |
141 | return -ENOEXEC; | |
142 | } | |
143 | ||
144 | /* | |
145 | * Free up memory used by kernel, initrd, and command line. This is temporary | |
146 | * memory allocation which is not needed any more after these buffers have | |
147 | * been loaded into separate segments and have been copied elsewhere. | |
148 | */ | |
149 | void kimage_file_post_load_cleanup(struct kimage *image) | |
150 | { | |
151 | struct purgatory_info *pi = &image->purgatory_info; | |
152 | ||
153 | vfree(image->kernel_buf); | |
154 | image->kernel_buf = NULL; | |
155 | ||
156 | vfree(image->initrd_buf); | |
157 | image->initrd_buf = NULL; | |
158 | ||
159 | kfree(image->cmdline_buf); | |
160 | image->cmdline_buf = NULL; | |
161 | ||
162 | vfree(pi->purgatory_buf); | |
163 | pi->purgatory_buf = NULL; | |
164 | ||
165 | vfree(pi->sechdrs); | |
166 | pi->sechdrs = NULL; | |
167 | ||
168 | /* See if architecture has anything to cleanup post load */ | |
169 | arch_kimage_file_post_load_cleanup(image); | |
170 | ||
171 | /* | |
172 | * Above call should have called into bootloader to free up | |
173 | * any data stored in kimage->image_loader_data. It should | |
174 | * be ok now to free it up. | |
175 | */ | |
176 | kfree(image->image_loader_data); | |
177 | image->image_loader_data = NULL; | |
178 | } | |
179 | ||
180 | #ifdef CONFIG_KEXEC_SIG | |
181 | static int | |
182 | kimage_validate_signature(struct kimage *image) | |
183 | { | |
184 | int ret; | |
185 | ||
186 | ret = arch_kexec_kernel_verify_sig(image, image->kernel_buf, | |
187 | image->kernel_buf_len); | |
188 | if (ret) { | |
189 | ||
190 | if (IS_ENABLED(CONFIG_KEXEC_SIG_FORCE)) { | |
191 | pr_notice("Enforced kernel signature verification failed (%d).\n", ret); | |
192 | return ret; | |
193 | } | |
194 | ||
195 | /* | |
196 | * If IMA is guaranteed to appraise a signature on the kexec | |
197 | * image, permit it even if the kernel is otherwise locked | |
198 | * down. | |
199 | */ | |
200 | if (!ima_appraise_signature(READING_KEXEC_IMAGE) && | |
201 | security_locked_down(LOCKDOWN_KEXEC)) | |
202 | return -EPERM; | |
203 | ||
204 | pr_debug("kernel signature verification failed (%d).\n", ret); | |
205 | } | |
206 | ||
207 | return 0; | |
208 | } | |
209 | #endif | |
210 | ||
211 | /* | |
212 | * In file mode list of segments is prepared by kernel. Copy relevant | |
213 | * data from user space, do error checking, prepare segment list | |
214 | */ | |
215 | static int | |
216 | kimage_file_prepare_segments(struct kimage *image, int kernel_fd, int initrd_fd, | |
217 | const char __user *cmdline_ptr, | |
218 | unsigned long cmdline_len, unsigned flags) | |
219 | { | |
220 | int ret; | |
221 | void *ldata; | |
222 | loff_t size; | |
223 | ||
224 | ret = kernel_read_file_from_fd(kernel_fd, &image->kernel_buf, | |
225 | &size, INT_MAX, READING_KEXEC_IMAGE); | |
226 | if (ret) | |
227 | return ret; | |
228 | image->kernel_buf_len = size; | |
229 | ||
230 | /* Call arch image probe handlers */ | |
231 | ret = arch_kexec_kernel_image_probe(image, image->kernel_buf, | |
232 | image->kernel_buf_len); | |
233 | if (ret) | |
234 | goto out; | |
235 | ||
236 | #ifdef CONFIG_KEXEC_SIG | |
237 | ret = kimage_validate_signature(image); | |
238 | ||
239 | if (ret) | |
240 | goto out; | |
241 | #endif | |
242 | /* It is possible that there no initramfs is being loaded */ | |
243 | if (!(flags & KEXEC_FILE_NO_INITRAMFS)) { | |
244 | ret = kernel_read_file_from_fd(initrd_fd, &image->initrd_buf, | |
245 | &size, INT_MAX, | |
246 | READING_KEXEC_INITRAMFS); | |
247 | if (ret) | |
248 | goto out; | |
249 | image->initrd_buf_len = size; | |
250 | } | |
251 | ||
252 | if (cmdline_len) { | |
253 | image->cmdline_buf = memdup_user(cmdline_ptr, cmdline_len); | |
254 | if (IS_ERR(image->cmdline_buf)) { | |
255 | ret = PTR_ERR(image->cmdline_buf); | |
256 | image->cmdline_buf = NULL; | |
257 | goto out; | |
258 | } | |
259 | ||
260 | image->cmdline_buf_len = cmdline_len; | |
261 | ||
262 | /* command line should be a string with last byte null */ | |
263 | if (image->cmdline_buf[cmdline_len - 1] != '\0') { | |
264 | ret = -EINVAL; | |
265 | goto out; | |
266 | } | |
267 | ||
268 | ima_kexec_cmdline(kernel_fd, image->cmdline_buf, | |
269 | image->cmdline_buf_len - 1); | |
270 | } | |
271 | ||
272 | /* IMA needs to pass the measurement list to the next kernel. */ | |
273 | ima_add_kexec_buffer(image); | |
274 | ||
275 | /* Call arch image load handlers */ | |
276 | ldata = arch_kexec_kernel_image_load(image); | |
277 | ||
278 | if (IS_ERR(ldata)) { | |
279 | ret = PTR_ERR(ldata); | |
280 | goto out; | |
281 | } | |
282 | ||
283 | image->image_loader_data = ldata; | |
284 | out: | |
285 | /* In case of error, free up all allocated memory in this function */ | |
286 | if (ret) | |
287 | kimage_file_post_load_cleanup(image); | |
288 | return ret; | |
289 | } | |
290 | ||
291 | static int | |
292 | kimage_file_alloc_init(struct kimage **rimage, int kernel_fd, | |
293 | int initrd_fd, const char __user *cmdline_ptr, | |
294 | unsigned long cmdline_len, unsigned long flags) | |
295 | { | |
296 | int ret; | |
297 | struct kimage *image; | |
298 | bool kexec_on_panic = flags & KEXEC_FILE_ON_CRASH; | |
299 | ||
300 | image = do_kimage_alloc_init(); | |
301 | if (!image) | |
302 | return -ENOMEM; | |
303 | ||
304 | image->file_mode = 1; | |
305 | ||
306 | if (kexec_on_panic) { | |
307 | /* Enable special crash kernel control page alloc policy. */ | |
308 | image->control_page = crashk_res.start; | |
309 | image->type = KEXEC_TYPE_CRASH; | |
310 | } | |
311 | ||
312 | ret = kimage_file_prepare_segments(image, kernel_fd, initrd_fd, | |
313 | cmdline_ptr, cmdline_len, flags); | |
314 | if (ret) | |
315 | goto out_free_image; | |
316 | ||
317 | ret = sanity_check_segment_list(image); | |
318 | if (ret) | |
319 | goto out_free_post_load_bufs; | |
320 | ||
321 | ret = -ENOMEM; | |
322 | image->control_code_page = kimage_alloc_control_pages(image, | |
323 | get_order(KEXEC_CONTROL_PAGE_SIZE)); | |
324 | if (!image->control_code_page) { | |
325 | pr_err("Could not allocate control_code_buffer\n"); | |
326 | goto out_free_post_load_bufs; | |
327 | } | |
328 | ||
329 | if (!kexec_on_panic) { | |
330 | image->swap_page = kimage_alloc_control_pages(image, 0); | |
331 | if (!image->swap_page) { | |
332 | pr_err("Could not allocate swap buffer\n"); | |
333 | goto out_free_control_pages; | |
334 | } | |
335 | } | |
336 | ||
337 | *rimage = image; | |
338 | return 0; | |
339 | out_free_control_pages: | |
340 | kimage_free_page_list(&image->control_pages); | |
341 | out_free_post_load_bufs: | |
342 | kimage_file_post_load_cleanup(image); | |
343 | out_free_image: | |
344 | kfree(image); | |
345 | return ret; | |
346 | } | |
347 | ||
348 | SYSCALL_DEFINE5(kexec_file_load, int, kernel_fd, int, initrd_fd, | |
349 | unsigned long, cmdline_len, const char __user *, cmdline_ptr, | |
350 | unsigned long, flags) | |
351 | { | |
352 | int ret = 0, i; | |
353 | struct kimage **dest_image, *image; | |
354 | ||
355 | /* We only trust the superuser with rebooting the system. */ | |
356 | if (!capable(CAP_SYS_BOOT) || kexec_load_disabled) | |
357 | return -EPERM; | |
358 | ||
359 | /* Make sure we have a legal set of flags */ | |
360 | if (flags != (flags & KEXEC_FILE_FLAGS)) | |
361 | return -EINVAL; | |
362 | ||
363 | image = NULL; | |
364 | ||
365 | if (!mutex_trylock(&kexec_mutex)) | |
366 | return -EBUSY; | |
367 | ||
368 | dest_image = &kexec_image; | |
369 | if (flags & KEXEC_FILE_ON_CRASH) { | |
370 | dest_image = &kexec_crash_image; | |
371 | if (kexec_crash_image) | |
372 | arch_kexec_unprotect_crashkres(); | |
373 | } | |
374 | ||
375 | if (flags & KEXEC_FILE_UNLOAD) | |
376 | goto exchange; | |
377 | ||
378 | /* | |
379 | * In case of crash, new kernel gets loaded in reserved region. It is | |
380 | * same memory where old crash kernel might be loaded. Free any | |
381 | * current crash dump kernel before we corrupt it. | |
382 | */ | |
383 | if (flags & KEXEC_FILE_ON_CRASH) | |
384 | kimage_free(xchg(&kexec_crash_image, NULL)); | |
385 | ||
386 | ret = kimage_file_alloc_init(&image, kernel_fd, initrd_fd, cmdline_ptr, | |
387 | cmdline_len, flags); | |
388 | if (ret) | |
389 | goto out; | |
390 | ||
391 | ret = machine_kexec_prepare(image); | |
392 | if (ret) | |
393 | goto out; | |
394 | ||
395 | /* | |
396 | * Some architecture(like S390) may touch the crash memory before | |
397 | * machine_kexec_prepare(), we must copy vmcoreinfo data after it. | |
398 | */ | |
399 | ret = kimage_crash_copy_vmcoreinfo(image); | |
400 | if (ret) | |
401 | goto out; | |
402 | ||
403 | ret = kexec_calculate_store_digests(image); | |
404 | if (ret) | |
405 | goto out; | |
406 | ||
407 | for (i = 0; i < image->nr_segments; i++) { | |
408 | struct kexec_segment *ksegment; | |
409 | ||
410 | ksegment = &image->segment[i]; | |
411 | pr_debug("Loading segment %d: buf=0x%p bufsz=0x%zx mem=0x%lx memsz=0x%zx\n", | |
412 | i, ksegment->buf, ksegment->bufsz, ksegment->mem, | |
413 | ksegment->memsz); | |
414 | ||
415 | ret = kimage_load_segment(image, &image->segment[i]); | |
416 | if (ret) | |
417 | goto out; | |
418 | } | |
419 | ||
420 | kimage_terminate(image); | |
421 | ||
422 | ret = machine_kexec_post_load(image); | |
423 | if (ret) | |
424 | goto out; | |
425 | ||
426 | /* | |
427 | * Free up any temporary buffers allocated which are not needed | |
428 | * after image has been loaded | |
429 | */ | |
430 | kimage_file_post_load_cleanup(image); | |
431 | exchange: | |
432 | image = xchg(dest_image, image); | |
433 | out: | |
434 | if ((flags & KEXEC_FILE_ON_CRASH) && kexec_crash_image) | |
435 | arch_kexec_protect_crashkres(); | |
436 | ||
437 | mutex_unlock(&kexec_mutex); | |
438 | kimage_free(image); | |
439 | return ret; | |
440 | } | |
441 | ||
442 | static int locate_mem_hole_top_down(unsigned long start, unsigned long end, | |
443 | struct kexec_buf *kbuf) | |
444 | { | |
445 | struct kimage *image = kbuf->image; | |
446 | unsigned long temp_start, temp_end; | |
447 | ||
448 | temp_end = min(end, kbuf->buf_max); | |
449 | temp_start = temp_end - kbuf->memsz; | |
450 | ||
451 | do { | |
452 | /* align down start */ | |
453 | temp_start = temp_start & (~(kbuf->buf_align - 1)); | |
454 | ||
455 | if (temp_start < start || temp_start < kbuf->buf_min) | |
456 | return 0; | |
457 | ||
458 | temp_end = temp_start + kbuf->memsz - 1; | |
459 | ||
460 | /* | |
461 | * Make sure this does not conflict with any of existing | |
462 | * segments | |
463 | */ | |
464 | if (kimage_is_destination_range(image, temp_start, temp_end)) { | |
465 | temp_start = temp_start - PAGE_SIZE; | |
466 | continue; | |
467 | } | |
468 | ||
469 | /* We found a suitable memory range */ | |
470 | break; | |
471 | } while (1); | |
472 | ||
473 | /* If we are here, we found a suitable memory range */ | |
474 | kbuf->mem = temp_start; | |
475 | ||
476 | /* Success, stop navigating through remaining System RAM ranges */ | |
477 | return 1; | |
478 | } | |
479 | ||
480 | static int locate_mem_hole_bottom_up(unsigned long start, unsigned long end, | |
481 | struct kexec_buf *kbuf) | |
482 | { | |
483 | struct kimage *image = kbuf->image; | |
484 | unsigned long temp_start, temp_end; | |
485 | ||
486 | temp_start = max(start, kbuf->buf_min); | |
487 | ||
488 | do { | |
489 | temp_start = ALIGN(temp_start, kbuf->buf_align); | |
490 | temp_end = temp_start + kbuf->memsz - 1; | |
491 | ||
492 | if (temp_end > end || temp_end > kbuf->buf_max) | |
493 | return 0; | |
494 | /* | |
495 | * Make sure this does not conflict with any of existing | |
496 | * segments | |
497 | */ | |
498 | if (kimage_is_destination_range(image, temp_start, temp_end)) { | |
499 | temp_start = temp_start + PAGE_SIZE; | |
500 | continue; | |
501 | } | |
502 | ||
503 | /* We found a suitable memory range */ | |
504 | break; | |
505 | } while (1); | |
506 | ||
507 | /* If we are here, we found a suitable memory range */ | |
508 | kbuf->mem = temp_start; | |
509 | ||
510 | /* Success, stop navigating through remaining System RAM ranges */ | |
511 | return 1; | |
512 | } | |
513 | ||
514 | static int locate_mem_hole_callback(struct resource *res, void *arg) | |
515 | { | |
516 | struct kexec_buf *kbuf = (struct kexec_buf *)arg; | |
517 | u64 start = res->start, end = res->end; | |
518 | unsigned long sz = end - start + 1; | |
519 | ||
520 | /* Returning 0 will take to next memory range */ | |
521 | ||
522 | /* Don't use memory that will be detected and handled by a driver. */ | |
523 | if (res->flags & IORESOURCE_MEM_DRIVER_MANAGED) | |
524 | return 0; | |
525 | ||
526 | if (sz < kbuf->memsz) | |
527 | return 0; | |
528 | ||
529 | if (end < kbuf->buf_min || start > kbuf->buf_max) | |
530 | return 0; | |
531 | ||
532 | /* | |
533 | * Allocate memory top down with-in ram range. Otherwise bottom up | |
534 | * allocation. | |
535 | */ | |
536 | if (kbuf->top_down) | |
537 | return locate_mem_hole_top_down(start, end, kbuf); | |
538 | return locate_mem_hole_bottom_up(start, end, kbuf); | |
539 | } | |
540 | ||
541 | #ifdef CONFIG_ARCH_KEEP_MEMBLOCK | |
542 | static int kexec_walk_memblock(struct kexec_buf *kbuf, | |
543 | int (*func)(struct resource *, void *)) | |
544 | { | |
545 | int ret = 0; | |
546 | u64 i; | |
547 | phys_addr_t mstart, mend; | |
548 | struct resource res = { }; | |
549 | ||
550 | if (kbuf->image->type == KEXEC_TYPE_CRASH) | |
551 | return func(&crashk_res, kbuf); | |
552 | ||
553 | if (kbuf->top_down) { | |
554 | for_each_free_mem_range_reverse(i, NUMA_NO_NODE, MEMBLOCK_NONE, | |
555 | &mstart, &mend, NULL) { | |
556 | /* | |
557 | * In memblock, end points to the first byte after the | |
558 | * range while in kexec, end points to the last byte | |
559 | * in the range. | |
560 | */ | |
561 | res.start = mstart; | |
562 | res.end = mend - 1; | |
563 | ret = func(&res, kbuf); | |
564 | if (ret) | |
565 | break; | |
566 | } | |
567 | } else { | |
568 | for_each_free_mem_range(i, NUMA_NO_NODE, MEMBLOCK_NONE, | |
569 | &mstart, &mend, NULL) { | |
570 | /* | |
571 | * In memblock, end points to the first byte after the | |
572 | * range while in kexec, end points to the last byte | |
573 | * in the range. | |
574 | */ | |
575 | res.start = mstart; | |
576 | res.end = mend - 1; | |
577 | ret = func(&res, kbuf); | |
578 | if (ret) | |
579 | break; | |
580 | } | |
581 | } | |
582 | ||
583 | return ret; | |
584 | } | |
585 | #else | |
586 | static int kexec_walk_memblock(struct kexec_buf *kbuf, | |
587 | int (*func)(struct resource *, void *)) | |
588 | { | |
589 | return 0; | |
590 | } | |
591 | #endif | |
592 | ||
593 | /** | |
594 | * kexec_walk_resources - call func(data) on free memory regions | |
595 | * @kbuf: Context info for the search. Also passed to @func. | |
596 | * @func: Function to call for each memory region. | |
597 | * | |
598 | * Return: The memory walk will stop when func returns a non-zero value | |
599 | * and that value will be returned. If all free regions are visited without | |
600 | * func returning non-zero, then zero will be returned. | |
601 | */ | |
602 | static int kexec_walk_resources(struct kexec_buf *kbuf, | |
603 | int (*func)(struct resource *, void *)) | |
604 | { | |
605 | if (kbuf->image->type == KEXEC_TYPE_CRASH) | |
606 | return walk_iomem_res_desc(crashk_res.desc, | |
607 | IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY, | |
608 | crashk_res.start, crashk_res.end, | |
609 | kbuf, func); | |
610 | else | |
611 | return walk_system_ram_res(0, ULONG_MAX, kbuf, func); | |
612 | } | |
613 | ||
614 | /** | |
615 | * kexec_locate_mem_hole - find free memory for the purgatory or the next kernel | |
616 | * @kbuf: Parameters for the memory search. | |
617 | * | |
618 | * On success, kbuf->mem will have the start address of the memory region found. | |
619 | * | |
620 | * Return: 0 on success, negative errno on error. | |
621 | */ | |
622 | int kexec_locate_mem_hole(struct kexec_buf *kbuf) | |
623 | { | |
624 | int ret; | |
625 | ||
626 | /* Arch knows where to place */ | |
627 | if (kbuf->mem != KEXEC_BUF_MEM_UNKNOWN) | |
628 | return 0; | |
629 | ||
630 | if (!IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) | |
631 | ret = kexec_walk_resources(kbuf, locate_mem_hole_callback); | |
632 | else | |
633 | ret = kexec_walk_memblock(kbuf, locate_mem_hole_callback); | |
634 | ||
635 | return ret == 1 ? 0 : -EADDRNOTAVAIL; | |
636 | } | |
637 | ||
638 | /** | |
639 | * arch_kexec_locate_mem_hole - Find free memory to place the segments. | |
640 | * @kbuf: Parameters for the memory search. | |
641 | * | |
642 | * On success, kbuf->mem will have the start address of the memory region found. | |
643 | * | |
644 | * Return: 0 on success, negative errno on error. | |
645 | */ | |
646 | int __weak arch_kexec_locate_mem_hole(struct kexec_buf *kbuf) | |
647 | { | |
648 | return kexec_locate_mem_hole(kbuf); | |
649 | } | |
650 | ||
651 | /** | |
652 | * kexec_add_buffer - place a buffer in a kexec segment | |
653 | * @kbuf: Buffer contents and memory parameters. | |
654 | * | |
655 | * This function assumes that kexec_mutex is held. | |
656 | * On successful return, @kbuf->mem will have the physical address of | |
657 | * the buffer in memory. | |
658 | * | |
659 | * Return: 0 on success, negative errno on error. | |
660 | */ | |
661 | int kexec_add_buffer(struct kexec_buf *kbuf) | |
662 | { | |
663 | struct kexec_segment *ksegment; | |
664 | int ret; | |
665 | ||
666 | /* Currently adding segment this way is allowed only in file mode */ | |
667 | if (!kbuf->image->file_mode) | |
668 | return -EINVAL; | |
669 | ||
670 | if (kbuf->image->nr_segments >= KEXEC_SEGMENT_MAX) | |
671 | return -EINVAL; | |
672 | ||
673 | /* | |
674 | * Make sure we are not trying to add buffer after allocating | |
675 | * control pages. All segments need to be placed first before | |
676 | * any control pages are allocated. As control page allocation | |
677 | * logic goes through list of segments to make sure there are | |
678 | * no destination overlaps. | |
679 | */ | |
680 | if (!list_empty(&kbuf->image->control_pages)) { | |
681 | WARN_ON(1); | |
682 | return -EINVAL; | |
683 | } | |
684 | ||
685 | /* Ensure minimum alignment needed for segments. */ | |
686 | kbuf->memsz = ALIGN(kbuf->memsz, PAGE_SIZE); | |
687 | kbuf->buf_align = max(kbuf->buf_align, PAGE_SIZE); | |
688 | ||
689 | /* Walk the RAM ranges and allocate a suitable range for the buffer */ | |
690 | ret = arch_kexec_locate_mem_hole(kbuf); | |
691 | if (ret) | |
692 | return ret; | |
693 | ||
694 | /* Found a suitable memory range */ | |
695 | ksegment = &kbuf->image->segment[kbuf->image->nr_segments]; | |
696 | ksegment->kbuf = kbuf->buffer; | |
697 | ksegment->bufsz = kbuf->bufsz; | |
698 | ksegment->mem = kbuf->mem; | |
699 | ksegment->memsz = kbuf->memsz; | |
700 | kbuf->image->nr_segments++; | |
701 | return 0; | |
702 | } | |
703 | ||
704 | /* Calculate and store the digest of segments */ | |
705 | static int kexec_calculate_store_digests(struct kimage *image) | |
706 | { | |
707 | struct crypto_shash *tfm; | |
708 | struct shash_desc *desc; | |
709 | int ret = 0, i, j, zero_buf_sz, sha_region_sz; | |
710 | size_t desc_size, nullsz; | |
711 | char *digest; | |
712 | void *zero_buf; | |
713 | struct kexec_sha_region *sha_regions; | |
714 | struct purgatory_info *pi = &image->purgatory_info; | |
715 | ||
716 | if (!IS_ENABLED(CONFIG_ARCH_HAS_KEXEC_PURGATORY)) | |
717 | return 0; | |
718 | ||
719 | zero_buf = __va(page_to_pfn(ZERO_PAGE(0)) << PAGE_SHIFT); | |
720 | zero_buf_sz = PAGE_SIZE; | |
721 | ||
722 | tfm = crypto_alloc_shash("sha256", 0, 0); | |
723 | if (IS_ERR(tfm)) { | |
724 | ret = PTR_ERR(tfm); | |
725 | goto out; | |
726 | } | |
727 | ||
728 | desc_size = crypto_shash_descsize(tfm) + sizeof(*desc); | |
729 | desc = kzalloc(desc_size, GFP_KERNEL); | |
730 | if (!desc) { | |
731 | ret = -ENOMEM; | |
732 | goto out_free_tfm; | |
733 | } | |
734 | ||
735 | sha_region_sz = KEXEC_SEGMENT_MAX * sizeof(struct kexec_sha_region); | |
736 | sha_regions = vzalloc(sha_region_sz); | |
737 | if (!sha_regions) | |
738 | goto out_free_desc; | |
739 | ||
740 | desc->tfm = tfm; | |
741 | ||
742 | ret = crypto_shash_init(desc); | |
743 | if (ret < 0) | |
744 | goto out_free_sha_regions; | |
745 | ||
746 | digest = kzalloc(SHA256_DIGEST_SIZE, GFP_KERNEL); | |
747 | if (!digest) { | |
748 | ret = -ENOMEM; | |
749 | goto out_free_sha_regions; | |
750 | } | |
751 | ||
752 | for (j = i = 0; i < image->nr_segments; i++) { | |
753 | struct kexec_segment *ksegment; | |
754 | ||
755 | ksegment = &image->segment[i]; | |
756 | /* | |
757 | * Skip purgatory as it will be modified once we put digest | |
758 | * info in purgatory. | |
759 | */ | |
760 | if (ksegment->kbuf == pi->purgatory_buf) | |
761 | continue; | |
762 | ||
763 | ret = crypto_shash_update(desc, ksegment->kbuf, | |
764 | ksegment->bufsz); | |
765 | if (ret) | |
766 | break; | |
767 | ||
768 | /* | |
769 | * Assume rest of the buffer is filled with zero and | |
770 | * update digest accordingly. | |
771 | */ | |
772 | nullsz = ksegment->memsz - ksegment->bufsz; | |
773 | while (nullsz) { | |
774 | unsigned long bytes = nullsz; | |
775 | ||
776 | if (bytes > zero_buf_sz) | |
777 | bytes = zero_buf_sz; | |
778 | ret = crypto_shash_update(desc, zero_buf, bytes); | |
779 | if (ret) | |
780 | break; | |
781 | nullsz -= bytes; | |
782 | } | |
783 | ||
784 | if (ret) | |
785 | break; | |
786 | ||
787 | sha_regions[j].start = ksegment->mem; | |
788 | sha_regions[j].len = ksegment->memsz; | |
789 | j++; | |
790 | } | |
791 | ||
792 | if (!ret) { | |
793 | ret = crypto_shash_final(desc, digest); | |
794 | if (ret) | |
795 | goto out_free_digest; | |
796 | ret = kexec_purgatory_get_set_symbol(image, "purgatory_sha_regions", | |
797 | sha_regions, sha_region_sz, 0); | |
798 | if (ret) | |
799 | goto out_free_digest; | |
800 | ||
801 | ret = kexec_purgatory_get_set_symbol(image, "purgatory_sha256_digest", | |
802 | digest, SHA256_DIGEST_SIZE, 0); | |
803 | if (ret) | |
804 | goto out_free_digest; | |
805 | } | |
806 | ||
807 | out_free_digest: | |
808 | kfree(digest); | |
809 | out_free_sha_regions: | |
810 | vfree(sha_regions); | |
811 | out_free_desc: | |
812 | kfree(desc); | |
813 | out_free_tfm: | |
814 | kfree(tfm); | |
815 | out: | |
816 | return ret; | |
817 | } | |
818 | ||
819 | #ifdef CONFIG_ARCH_HAS_KEXEC_PURGATORY | |
820 | /* | |
821 | * kexec_purgatory_setup_kbuf - prepare buffer to load purgatory. | |
822 | * @pi: Purgatory to be loaded. | |
823 | * @kbuf: Buffer to setup. | |
824 | * | |
825 | * Allocates the memory needed for the buffer. Caller is responsible to free | |
826 | * the memory after use. | |
827 | * | |
828 | * Return: 0 on success, negative errno on error. | |
829 | */ | |
830 | static int kexec_purgatory_setup_kbuf(struct purgatory_info *pi, | |
831 | struct kexec_buf *kbuf) | |
832 | { | |
833 | const Elf_Shdr *sechdrs; | |
834 | unsigned long bss_align; | |
835 | unsigned long bss_sz; | |
836 | unsigned long align; | |
837 | int i, ret; | |
838 | ||
839 | sechdrs = (void *)pi->ehdr + pi->ehdr->e_shoff; | |
840 | kbuf->buf_align = bss_align = 1; | |
841 | kbuf->bufsz = bss_sz = 0; | |
842 | ||
843 | for (i = 0; i < pi->ehdr->e_shnum; i++) { | |
844 | if (!(sechdrs[i].sh_flags & SHF_ALLOC)) | |
845 | continue; | |
846 | ||
847 | align = sechdrs[i].sh_addralign; | |
848 | if (sechdrs[i].sh_type != SHT_NOBITS) { | |
849 | if (kbuf->buf_align < align) | |
850 | kbuf->buf_align = align; | |
851 | kbuf->bufsz = ALIGN(kbuf->bufsz, align); | |
852 | kbuf->bufsz += sechdrs[i].sh_size; | |
853 | } else { | |
854 | if (bss_align < align) | |
855 | bss_align = align; | |
856 | bss_sz = ALIGN(bss_sz, align); | |
857 | bss_sz += sechdrs[i].sh_size; | |
858 | } | |
859 | } | |
860 | kbuf->bufsz = ALIGN(kbuf->bufsz, bss_align); | |
861 | kbuf->memsz = kbuf->bufsz + bss_sz; | |
862 | if (kbuf->buf_align < bss_align) | |
863 | kbuf->buf_align = bss_align; | |
864 | ||
865 | kbuf->buffer = vzalloc(kbuf->bufsz); | |
866 | if (!kbuf->buffer) | |
867 | return -ENOMEM; | |
868 | pi->purgatory_buf = kbuf->buffer; | |
869 | ||
870 | ret = kexec_add_buffer(kbuf); | |
871 | if (ret) | |
872 | goto out; | |
873 | ||
874 | return 0; | |
875 | out: | |
876 | vfree(pi->purgatory_buf); | |
877 | pi->purgatory_buf = NULL; | |
878 | return ret; | |
879 | } | |
880 | ||
881 | /* | |
882 | * kexec_purgatory_setup_sechdrs - prepares the pi->sechdrs buffer. | |
883 | * @pi: Purgatory to be loaded. | |
884 | * @kbuf: Buffer prepared to store purgatory. | |
885 | * | |
886 | * Allocates the memory needed for the buffer. Caller is responsible to free | |
887 | * the memory after use. | |
888 | * | |
889 | * Return: 0 on success, negative errno on error. | |
890 | */ | |
891 | static int kexec_purgatory_setup_sechdrs(struct purgatory_info *pi, | |
892 | struct kexec_buf *kbuf) | |
893 | { | |
894 | unsigned long bss_addr; | |
895 | unsigned long offset; | |
896 | Elf_Shdr *sechdrs; | |
897 | int i; | |
898 | ||
899 | /* | |
900 | * The section headers in kexec_purgatory are read-only. In order to | |
901 | * have them modifiable make a temporary copy. | |
902 | */ | |
903 | sechdrs = vzalloc(array_size(sizeof(Elf_Shdr), pi->ehdr->e_shnum)); | |
904 | if (!sechdrs) | |
905 | return -ENOMEM; | |
906 | memcpy(sechdrs, (void *)pi->ehdr + pi->ehdr->e_shoff, | |
907 | pi->ehdr->e_shnum * sizeof(Elf_Shdr)); | |
908 | pi->sechdrs = sechdrs; | |
909 | ||
910 | offset = 0; | |
911 | bss_addr = kbuf->mem + kbuf->bufsz; | |
912 | kbuf->image->start = pi->ehdr->e_entry; | |
913 | ||
914 | for (i = 0; i < pi->ehdr->e_shnum; i++) { | |
915 | unsigned long align; | |
916 | void *src, *dst; | |
917 | ||
918 | if (!(sechdrs[i].sh_flags & SHF_ALLOC)) | |
919 | continue; | |
920 | ||
921 | align = sechdrs[i].sh_addralign; | |
922 | if (sechdrs[i].sh_type == SHT_NOBITS) { | |
923 | bss_addr = ALIGN(bss_addr, align); | |
924 | sechdrs[i].sh_addr = bss_addr; | |
925 | bss_addr += sechdrs[i].sh_size; | |
926 | continue; | |
927 | } | |
928 | ||
929 | offset = ALIGN(offset, align); | |
930 | if (sechdrs[i].sh_flags & SHF_EXECINSTR && | |
931 | pi->ehdr->e_entry >= sechdrs[i].sh_addr && | |
932 | pi->ehdr->e_entry < (sechdrs[i].sh_addr | |
933 | + sechdrs[i].sh_size)) { | |
934 | kbuf->image->start -= sechdrs[i].sh_addr; | |
935 | kbuf->image->start += kbuf->mem + offset; | |
936 | } | |
937 | ||
938 | src = (void *)pi->ehdr + sechdrs[i].sh_offset; | |
939 | dst = pi->purgatory_buf + offset; | |
940 | memcpy(dst, src, sechdrs[i].sh_size); | |
941 | ||
942 | sechdrs[i].sh_addr = kbuf->mem + offset; | |
943 | sechdrs[i].sh_offset = offset; | |
944 | offset += sechdrs[i].sh_size; | |
945 | } | |
946 | ||
947 | return 0; | |
948 | } | |
949 | ||
950 | static int kexec_apply_relocations(struct kimage *image) | |
951 | { | |
952 | int i, ret; | |
953 | struct purgatory_info *pi = &image->purgatory_info; | |
954 | const Elf_Shdr *sechdrs; | |
955 | ||
956 | sechdrs = (void *)pi->ehdr + pi->ehdr->e_shoff; | |
957 | ||
958 | for (i = 0; i < pi->ehdr->e_shnum; i++) { | |
959 | const Elf_Shdr *relsec; | |
960 | const Elf_Shdr *symtab; | |
961 | Elf_Shdr *section; | |
962 | ||
963 | relsec = sechdrs + i; | |
964 | ||
965 | if (relsec->sh_type != SHT_RELA && | |
966 | relsec->sh_type != SHT_REL) | |
967 | continue; | |
968 | ||
969 | /* | |
970 | * For section of type SHT_RELA/SHT_REL, | |
971 | * ->sh_link contains section header index of associated | |
972 | * symbol table. And ->sh_info contains section header | |
973 | * index of section to which relocations apply. | |
974 | */ | |
975 | if (relsec->sh_info >= pi->ehdr->e_shnum || | |
976 | relsec->sh_link >= pi->ehdr->e_shnum) | |
977 | return -ENOEXEC; | |
978 | ||
979 | section = pi->sechdrs + relsec->sh_info; | |
980 | symtab = sechdrs + relsec->sh_link; | |
981 | ||
982 | if (!(section->sh_flags & SHF_ALLOC)) | |
983 | continue; | |
984 | ||
985 | /* | |
986 | * symtab->sh_link contain section header index of associated | |
987 | * string table. | |
988 | */ | |
989 | if (symtab->sh_link >= pi->ehdr->e_shnum) | |
990 | /* Invalid section number? */ | |
991 | continue; | |
992 | ||
993 | /* | |
994 | * Respective architecture needs to provide support for applying | |
995 | * relocations of type SHT_RELA/SHT_REL. | |
996 | */ | |
997 | if (relsec->sh_type == SHT_RELA) | |
998 | ret = arch_kexec_apply_relocations_add(pi, section, | |
999 | relsec, symtab); | |
1000 | else if (relsec->sh_type == SHT_REL) | |
1001 | ret = arch_kexec_apply_relocations(pi, section, | |
1002 | relsec, symtab); | |
1003 | if (ret) | |
1004 | return ret; | |
1005 | } | |
1006 | ||
1007 | return 0; | |
1008 | } | |
1009 | ||
1010 | /* | |
1011 | * kexec_load_purgatory - Load and relocate the purgatory object. | |
1012 | * @image: Image to add the purgatory to. | |
1013 | * @kbuf: Memory parameters to use. | |
1014 | * | |
1015 | * Allocates the memory needed for image->purgatory_info.sechdrs and | |
1016 | * image->purgatory_info.purgatory_buf/kbuf->buffer. Caller is responsible | |
1017 | * to free the memory after use. | |
1018 | * | |
1019 | * Return: 0 on success, negative errno on error. | |
1020 | */ | |
1021 | int kexec_load_purgatory(struct kimage *image, struct kexec_buf *kbuf) | |
1022 | { | |
1023 | struct purgatory_info *pi = &image->purgatory_info; | |
1024 | int ret; | |
1025 | ||
1026 | if (kexec_purgatory_size <= 0) | |
1027 | return -EINVAL; | |
1028 | ||
1029 | pi->ehdr = (const Elf_Ehdr *)kexec_purgatory; | |
1030 | ||
1031 | ret = kexec_purgatory_setup_kbuf(pi, kbuf); | |
1032 | if (ret) | |
1033 | return ret; | |
1034 | ||
1035 | ret = kexec_purgatory_setup_sechdrs(pi, kbuf); | |
1036 | if (ret) | |
1037 | goto out_free_kbuf; | |
1038 | ||
1039 | ret = kexec_apply_relocations(image); | |
1040 | if (ret) | |
1041 | goto out; | |
1042 | ||
1043 | return 0; | |
1044 | out: | |
1045 | vfree(pi->sechdrs); | |
1046 | pi->sechdrs = NULL; | |
1047 | out_free_kbuf: | |
1048 | vfree(pi->purgatory_buf); | |
1049 | pi->purgatory_buf = NULL; | |
1050 | return ret; | |
1051 | } | |
1052 | ||
1053 | /* | |
1054 | * kexec_purgatory_find_symbol - find a symbol in the purgatory | |
1055 | * @pi: Purgatory to search in. | |
1056 | * @name: Name of the symbol. | |
1057 | * | |
1058 | * Return: pointer to symbol in read-only symtab on success, NULL on error. | |
1059 | */ | |
1060 | static const Elf_Sym *kexec_purgatory_find_symbol(struct purgatory_info *pi, | |
1061 | const char *name) | |
1062 | { | |
1063 | const Elf_Shdr *sechdrs; | |
1064 | const Elf_Ehdr *ehdr; | |
1065 | const Elf_Sym *syms; | |
1066 | const char *strtab; | |
1067 | int i, k; | |
1068 | ||
1069 | if (!pi->ehdr) | |
1070 | return NULL; | |
1071 | ||
1072 | ehdr = pi->ehdr; | |
1073 | sechdrs = (void *)ehdr + ehdr->e_shoff; | |
1074 | ||
1075 | for (i = 0; i < ehdr->e_shnum; i++) { | |
1076 | if (sechdrs[i].sh_type != SHT_SYMTAB) | |
1077 | continue; | |
1078 | ||
1079 | if (sechdrs[i].sh_link >= ehdr->e_shnum) | |
1080 | /* Invalid strtab section number */ | |
1081 | continue; | |
1082 | strtab = (void *)ehdr + sechdrs[sechdrs[i].sh_link].sh_offset; | |
1083 | syms = (void *)ehdr + sechdrs[i].sh_offset; | |
1084 | ||
1085 | /* Go through symbols for a match */ | |
1086 | for (k = 0; k < sechdrs[i].sh_size/sizeof(Elf_Sym); k++) { | |
1087 | if (ELF_ST_BIND(syms[k].st_info) != STB_GLOBAL) | |
1088 | continue; | |
1089 | ||
1090 | if (strcmp(strtab + syms[k].st_name, name) != 0) | |
1091 | continue; | |
1092 | ||
1093 | if (syms[k].st_shndx == SHN_UNDEF || | |
1094 | syms[k].st_shndx >= ehdr->e_shnum) { | |
1095 | pr_debug("Symbol: %s has bad section index %d.\n", | |
1096 | name, syms[k].st_shndx); | |
1097 | return NULL; | |
1098 | } | |
1099 | ||
1100 | /* Found the symbol we are looking for */ | |
1101 | return &syms[k]; | |
1102 | } | |
1103 | } | |
1104 | ||
1105 | return NULL; | |
1106 | } | |
1107 | ||
1108 | void *kexec_purgatory_get_symbol_addr(struct kimage *image, const char *name) | |
1109 | { | |
1110 | struct purgatory_info *pi = &image->purgatory_info; | |
1111 | const Elf_Sym *sym; | |
1112 | Elf_Shdr *sechdr; | |
1113 | ||
1114 | sym = kexec_purgatory_find_symbol(pi, name); | |
1115 | if (!sym) | |
1116 | return ERR_PTR(-EINVAL); | |
1117 | ||
1118 | sechdr = &pi->sechdrs[sym->st_shndx]; | |
1119 | ||
1120 | /* | |
1121 | * Returns the address where symbol will finally be loaded after | |
1122 | * kexec_load_segment() | |
1123 | */ | |
1124 | return (void *)(sechdr->sh_addr + sym->st_value); | |
1125 | } | |
1126 | ||
1127 | /* | |
1128 | * Get or set value of a symbol. If "get_value" is true, symbol value is | |
1129 | * returned in buf otherwise symbol value is set based on value in buf. | |
1130 | */ | |
1131 | int kexec_purgatory_get_set_symbol(struct kimage *image, const char *name, | |
1132 | void *buf, unsigned int size, bool get_value) | |
1133 | { | |
1134 | struct purgatory_info *pi = &image->purgatory_info; | |
1135 | const Elf_Sym *sym; | |
1136 | Elf_Shdr *sec; | |
1137 | char *sym_buf; | |
1138 | ||
1139 | sym = kexec_purgatory_find_symbol(pi, name); | |
1140 | if (!sym) | |
1141 | return -EINVAL; | |
1142 | ||
1143 | if (sym->st_size != size) { | |
1144 | pr_err("symbol %s size mismatch: expected %lu actual %u\n", | |
1145 | name, (unsigned long)sym->st_size, size); | |
1146 | return -EINVAL; | |
1147 | } | |
1148 | ||
1149 | sec = pi->sechdrs + sym->st_shndx; | |
1150 | ||
1151 | if (sec->sh_type == SHT_NOBITS) { | |
1152 | pr_err("symbol %s is in a bss section. Cannot %s\n", name, | |
1153 | get_value ? "get" : "set"); | |
1154 | return -EINVAL; | |
1155 | } | |
1156 | ||
1157 | sym_buf = (char *)pi->purgatory_buf + sec->sh_offset + sym->st_value; | |
1158 | ||
1159 | if (get_value) | |
1160 | memcpy((void *)buf, sym_buf, size); | |
1161 | else | |
1162 | memcpy((void *)sym_buf, buf, size); | |
1163 | ||
1164 | return 0; | |
1165 | } | |
1166 | #endif /* CONFIG_ARCH_HAS_KEXEC_PURGATORY */ | |
1167 | ||
1168 | int crash_exclude_mem_range(struct crash_mem *mem, | |
1169 | unsigned long long mstart, unsigned long long mend) | |
1170 | { | |
1171 | int i, j; | |
1172 | unsigned long long start, end, p_start, p_end; | |
1173 | struct crash_mem_range temp_range = {0, 0}; | |
1174 | ||
1175 | for (i = 0; i < mem->nr_ranges; i++) { | |
1176 | start = mem->ranges[i].start; | |
1177 | end = mem->ranges[i].end; | |
1178 | p_start = mstart; | |
1179 | p_end = mend; | |
1180 | ||
1181 | if (mstart > end || mend < start) | |
1182 | continue; | |
1183 | ||
1184 | /* Truncate any area outside of range */ | |
1185 | if (mstart < start) | |
1186 | p_start = start; | |
1187 | if (mend > end) | |
1188 | p_end = end; | |
1189 | ||
1190 | /* Found completely overlapping range */ | |
1191 | if (p_start == start && p_end == end) { | |
1192 | mem->ranges[i].start = 0; | |
1193 | mem->ranges[i].end = 0; | |
1194 | if (i < mem->nr_ranges - 1) { | |
1195 | /* Shift rest of the ranges to left */ | |
1196 | for (j = i; j < mem->nr_ranges - 1; j++) { | |
1197 | mem->ranges[j].start = | |
1198 | mem->ranges[j+1].start; | |
1199 | mem->ranges[j].end = | |
1200 | mem->ranges[j+1].end; | |
1201 | } | |
1202 | ||
1203 | /* | |
1204 | * Continue to check if there are another overlapping ranges | |
1205 | * from the current position because of shifting the above | |
1206 | * mem ranges. | |
1207 | */ | |
1208 | i--; | |
1209 | mem->nr_ranges--; | |
1210 | continue; | |
1211 | } | |
1212 | mem->nr_ranges--; | |
1213 | return 0; | |
1214 | } | |
1215 | ||
1216 | if (p_start > start && p_end < end) { | |
1217 | /* Split original range */ | |
1218 | mem->ranges[i].end = p_start - 1; | |
1219 | temp_range.start = p_end + 1; | |
1220 | temp_range.end = end; | |
1221 | } else if (p_start != start) | |
1222 | mem->ranges[i].end = p_start - 1; | |
1223 | else | |
1224 | mem->ranges[i].start = p_end + 1; | |
1225 | break; | |
1226 | } | |
1227 | ||
1228 | /* If a split happened, add the split to array */ | |
1229 | if (!temp_range.end) | |
1230 | return 0; | |
1231 | ||
1232 | /* Split happened */ | |
1233 | if (i == mem->max_nr_ranges - 1) | |
1234 | return -ENOMEM; | |
1235 | ||
1236 | /* Location where new range should go */ | |
1237 | j = i + 1; | |
1238 | if (j < mem->nr_ranges) { | |
1239 | /* Move over all ranges one slot towards the end */ | |
1240 | for (i = mem->nr_ranges - 1; i >= j; i--) | |
1241 | mem->ranges[i + 1] = mem->ranges[i]; | |
1242 | } | |
1243 | ||
1244 | mem->ranges[j].start = temp_range.start; | |
1245 | mem->ranges[j].end = temp_range.end; | |
1246 | mem->nr_ranges++; | |
1247 | return 0; | |
1248 | } | |
1249 | ||
1250 | int crash_prepare_elf64_headers(struct crash_mem *mem, int kernel_map, | |
1251 | void **addr, unsigned long *sz) | |
1252 | { | |
1253 | Elf64_Ehdr *ehdr; | |
1254 | Elf64_Phdr *phdr; | |
1255 | unsigned long nr_cpus = num_possible_cpus(), nr_phdr, elf_sz; | |
1256 | unsigned char *buf; | |
1257 | unsigned int cpu, i; | |
1258 | unsigned long long notes_addr; | |
1259 | unsigned long mstart, mend; | |
1260 | ||
1261 | /* extra phdr for vmcoreinfo ELF note */ | |
1262 | nr_phdr = nr_cpus + 1; | |
1263 | nr_phdr += mem->nr_ranges; | |
1264 | ||
1265 | /* | |
1266 | * kexec-tools creates an extra PT_LOAD phdr for kernel text mapping | |
1267 | * area (for example, ffffffff80000000 - ffffffffa0000000 on x86_64). | |
1268 | * I think this is required by tools like gdb. So same physical | |
1269 | * memory will be mapped in two ELF headers. One will contain kernel | |
1270 | * text virtual addresses and other will have __va(physical) addresses. | |
1271 | */ | |
1272 | ||
1273 | nr_phdr++; | |
1274 | elf_sz = sizeof(Elf64_Ehdr) + nr_phdr * sizeof(Elf64_Phdr); | |
1275 | elf_sz = ALIGN(elf_sz, ELF_CORE_HEADER_ALIGN); | |
1276 | ||
1277 | buf = vzalloc(elf_sz); | |
1278 | if (!buf) | |
1279 | return -ENOMEM; | |
1280 | ||
1281 | ehdr = (Elf64_Ehdr *)buf; | |
1282 | phdr = (Elf64_Phdr *)(ehdr + 1); | |
1283 | memcpy(ehdr->e_ident, ELFMAG, SELFMAG); | |
1284 | ehdr->e_ident[EI_CLASS] = ELFCLASS64; | |
1285 | ehdr->e_ident[EI_DATA] = ELFDATA2LSB; | |
1286 | ehdr->e_ident[EI_VERSION] = EV_CURRENT; | |
1287 | ehdr->e_ident[EI_OSABI] = ELF_OSABI; | |
1288 | memset(ehdr->e_ident + EI_PAD, 0, EI_NIDENT - EI_PAD); | |
1289 | ehdr->e_type = ET_CORE; | |
1290 | ehdr->e_machine = ELF_ARCH; | |
1291 | ehdr->e_version = EV_CURRENT; | |
1292 | ehdr->e_phoff = sizeof(Elf64_Ehdr); | |
1293 | ehdr->e_ehsize = sizeof(Elf64_Ehdr); | |
1294 | ehdr->e_phentsize = sizeof(Elf64_Phdr); | |
1295 | ||
1296 | /* Prepare one phdr of type PT_NOTE for each present CPU */ | |
1297 | for_each_present_cpu(cpu) { | |
1298 | phdr->p_type = PT_NOTE; | |
1299 | notes_addr = per_cpu_ptr_to_phys(per_cpu_ptr(crash_notes, cpu)); | |
1300 | phdr->p_offset = phdr->p_paddr = notes_addr; | |
1301 | phdr->p_filesz = phdr->p_memsz = sizeof(note_buf_t); | |
1302 | (ehdr->e_phnum)++; | |
1303 | phdr++; | |
1304 | } | |
1305 | ||
1306 | /* Prepare one PT_NOTE header for vmcoreinfo */ | |
1307 | phdr->p_type = PT_NOTE; | |
1308 | phdr->p_offset = phdr->p_paddr = paddr_vmcoreinfo_note(); | |
1309 | phdr->p_filesz = phdr->p_memsz = VMCOREINFO_NOTE_SIZE; | |
1310 | (ehdr->e_phnum)++; | |
1311 | phdr++; | |
1312 | ||
1313 | /* Prepare PT_LOAD type program header for kernel text region */ | |
1314 | if (kernel_map) { | |
1315 | phdr->p_type = PT_LOAD; | |
1316 | phdr->p_flags = PF_R|PF_W|PF_X; | |
1317 | phdr->p_vaddr = (unsigned long) _text; | |
1318 | phdr->p_filesz = phdr->p_memsz = _end - _text; | |
1319 | phdr->p_offset = phdr->p_paddr = __pa_symbol(_text); | |
1320 | ehdr->e_phnum++; | |
1321 | phdr++; | |
1322 | } | |
1323 | ||
1324 | /* Go through all the ranges in mem->ranges[] and prepare phdr */ | |
1325 | for (i = 0; i < mem->nr_ranges; i++) { | |
1326 | mstart = mem->ranges[i].start; | |
1327 | mend = mem->ranges[i].end; | |
1328 | ||
1329 | phdr->p_type = PT_LOAD; | |
1330 | phdr->p_flags = PF_R|PF_W|PF_X; | |
1331 | phdr->p_offset = mstart; | |
1332 | ||
1333 | phdr->p_paddr = mstart; | |
1334 | phdr->p_vaddr = (unsigned long) __va(mstart); | |
1335 | phdr->p_filesz = phdr->p_memsz = mend - mstart + 1; | |
1336 | phdr->p_align = 0; | |
1337 | ehdr->e_phnum++; | |
1338 | pr_debug("Crash PT_LOAD ELF header. phdr=%p vaddr=0x%llx, paddr=0x%llx, sz=0x%llx e_phnum=%d p_offset=0x%llx\n", | |
1339 | phdr, phdr->p_vaddr, phdr->p_paddr, phdr->p_filesz, | |
1340 | ehdr->e_phnum, phdr->p_offset); | |
1341 | phdr++; | |
1342 | } | |
1343 | ||
1344 | *addr = buf; | |
1345 | *sz = elf_sz; | |
1346 | return 0; | |
1347 | } |