Commit | Line | Data |
---|---|---|
40b0b3f8 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
a43cac0d DY |
2 | /* |
3 | * kexec: kexec_file_load system call | |
4 | * | |
5 | * Copyright (C) 2014 Red Hat Inc. | |
6 | * Authors: | |
7 | * Vivek Goyal <vgoyal@redhat.com> | |
a43cac0d DY |
8 | */ |
9 | ||
de90a6bc MH |
10 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
11 | ||
a43cac0d DY |
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> | |
735c2f90 | 17 | #include <linux/memblock.h> |
a43cac0d DY |
18 | #include <linux/mutex.h> |
19 | #include <linux/list.h> | |
b804defe | 20 | #include <linux/fs.h> |
7b8589cc | 21 | #include <linux/ima.h> |
a43cac0d | 22 | #include <crypto/hash.h> |
a24d22b2 | 23 | #include <crypto/sha2.h> |
babac4a8 AT |
24 | #include <linux/elf.h> |
25 | #include <linux/elfcore.h> | |
26 | #include <linux/kernel.h> | |
b89999d0 | 27 | #include <linux/kernel_read_file.h> |
a43cac0d DY |
28 | #include <linux/syscalls.h> |
29 | #include <linux/vmalloc.h> | |
30 | #include "kexec_internal.h" | |
31 | ||
af16df54 CX |
32 | #ifdef CONFIG_KEXEC_SIG |
33 | static bool sig_enforce = IS_ENABLED(CONFIG_KEXEC_SIG_FORCE); | |
34 | ||
35 | void set_kexec_sig_enforced(void) | |
36 | { | |
37 | sig_enforce = true; | |
38 | } | |
39 | #endif | |
40 | ||
a43cac0d DY |
41 | static int kexec_calculate_store_digests(struct kimage *image); |
42 | ||
f4da7afe PT |
43 | /* Maximum size in bytes for kernel/initrd files. */ |
44 | #define KEXEC_FILE_SIZE_MAX min_t(s64, 4LL << 30, SSIZE_MAX) | |
45 | ||
9ec4ecef AT |
46 | /* |
47 | * Currently this is the only default function that is exported as some | |
48 | * architectures need it to do additional handlings. | |
49 | * In the future, other default functions may be exported too if required. | |
50 | */ | |
51 | int kexec_image_probe_default(struct kimage *image, void *buf, | |
52 | unsigned long buf_len) | |
53 | { | |
54 | const struct kexec_file_ops * const *fops; | |
55 | int ret = -ENOEXEC; | |
56 | ||
57 | for (fops = &kexec_file_loaders[0]; *fops && (*fops)->probe; ++fops) { | |
58 | ret = (*fops)->probe(buf, buf_len); | |
59 | if (!ret) { | |
60 | image->fops = *fops; | |
61 | return ret; | |
62 | } | |
63 | } | |
64 | ||
65 | return ret; | |
66 | } | |
67 | ||
fb15abdc | 68 | static void *kexec_image_load_default(struct kimage *image) |
9ec4ecef AT |
69 | { |
70 | if (!image->fops || !image->fops->load) | |
71 | return ERR_PTR(-ENOEXEC); | |
72 | ||
73 | return image->fops->load(image, image->kernel_buf, | |
74 | image->kernel_buf_len, image->initrd_buf, | |
75 | image->initrd_buf_len, image->cmdline_buf, | |
76 | image->cmdline_buf_len); | |
a43cac0d DY |
77 | } |
78 | ||
92a98a2b | 79 | int kexec_image_post_load_cleanup_default(struct kimage *image) |
9ec4ecef AT |
80 | { |
81 | if (!image->fops || !image->fops->cleanup) | |
82 | return 0; | |
83 | ||
84 | return image->fops->cleanup(image->image_loader_data); | |
a43cac0d DY |
85 | } |
86 | ||
a43cac0d DY |
87 | /* |
88 | * Free up memory used by kernel, initrd, and command line. This is temporary | |
89 | * memory allocation which is not needed any more after these buffers have | |
90 | * been loaded into separate segments and have been copied elsewhere. | |
91 | */ | |
92 | void kimage_file_post_load_cleanup(struct kimage *image) | |
93 | { | |
94 | struct purgatory_info *pi = &image->purgatory_info; | |
95 | ||
96 | vfree(image->kernel_buf); | |
97 | image->kernel_buf = NULL; | |
98 | ||
99 | vfree(image->initrd_buf); | |
100 | image->initrd_buf = NULL; | |
101 | ||
102 | kfree(image->cmdline_buf); | |
103 | image->cmdline_buf = NULL; | |
104 | ||
105 | vfree(pi->purgatory_buf); | |
106 | pi->purgatory_buf = NULL; | |
107 | ||
108 | vfree(pi->sechdrs); | |
109 | pi->sechdrs = NULL; | |
110 | ||
f31e3386 LR |
111 | #ifdef CONFIG_IMA_KEXEC |
112 | vfree(image->ima_buffer); | |
113 | image->ima_buffer = NULL; | |
114 | #endif /* CONFIG_IMA_KEXEC */ | |
115 | ||
a43cac0d DY |
116 | /* See if architecture has anything to cleanup post load */ |
117 | arch_kimage_file_post_load_cleanup(image); | |
118 | ||
119 | /* | |
120 | * Above call should have called into bootloader to free up | |
121 | * any data stored in kimage->image_loader_data. It should | |
122 | * be ok now to free it up. | |
123 | */ | |
124 | kfree(image->image_loader_data); | |
125 | image->image_loader_data = NULL; | |
cbc2fe9d BH |
126 | |
127 | kexec_file_dbg_print = false; | |
a43cac0d DY |
128 | } |
129 | ||
99d5cadf | 130 | #ifdef CONFIG_KEXEC_SIG |
c903dae8 CX |
131 | #ifdef CONFIG_SIGNED_PE_FILE_VERIFICATION |
132 | int kexec_kernel_verify_pe_sig(const char *kernel, unsigned long kernel_len) | |
133 | { | |
134 | int ret; | |
135 | ||
136 | ret = verify_pefile_signature(kernel, kernel_len, | |
137 | VERIFY_USE_SECONDARY_KEYRING, | |
138 | VERIFYING_KEXEC_PE_SIGNATURE); | |
139 | if (ret == -ENOKEY && IS_ENABLED(CONFIG_INTEGRITY_PLATFORM_KEYRING)) { | |
140 | ret = verify_pefile_signature(kernel, kernel_len, | |
141 | VERIFY_USE_PLATFORM_KEYRING, | |
142 | VERIFYING_KEXEC_PE_SIGNATURE); | |
143 | } | |
144 | return ret; | |
145 | } | |
146 | #endif | |
147 | ||
689a7149 CX |
148 | static int kexec_image_verify_sig(struct kimage *image, void *buf, |
149 | unsigned long buf_len) | |
150 | { | |
151 | if (!image->fops || !image->fops->verify_sig) { | |
152 | pr_debug("kernel loader does not support signature verification.\n"); | |
153 | return -EKEYREJECTED; | |
154 | } | |
155 | ||
156 | return image->fops->verify_sig(buf, buf_len); | |
157 | } | |
158 | ||
99d5cadf JB |
159 | static int |
160 | kimage_validate_signature(struct kimage *image) | |
161 | { | |
99d5cadf JB |
162 | int ret; |
163 | ||
689a7149 CX |
164 | ret = kexec_image_verify_sig(image, image->kernel_buf, |
165 | image->kernel_buf_len); | |
fd7af71b | 166 | if (ret) { |
99d5cadf | 167 | |
af16df54 | 168 | if (sig_enforce) { |
fd7af71b | 169 | pr_notice("Enforced kernel signature verification failed (%d).\n", ret); |
99d5cadf JB |
170 | return ret; |
171 | } | |
172 | ||
fd7af71b LJ |
173 | /* |
174 | * If IMA is guaranteed to appraise a signature on the kexec | |
29d3c1c8 MG |
175 | * image, permit it even if the kernel is otherwise locked |
176 | * down. | |
177 | */ | |
178 | if (!ima_appraise_signature(READING_KEXEC_IMAGE) && | |
179 | security_locked_down(LOCKDOWN_KEXEC)) | |
180 | return -EPERM; | |
181 | ||
fd7af71b | 182 | pr_debug("kernel signature verification failed (%d).\n", ret); |
99d5cadf JB |
183 | } |
184 | ||
fd7af71b | 185 | return 0; |
99d5cadf JB |
186 | } |
187 | #endif | |
188 | ||
a43cac0d DY |
189 | /* |
190 | * In file mode list of segments is prepared by kernel. Copy relevant | |
191 | * data from user space, do error checking, prepare segment list | |
192 | */ | |
193 | static int | |
194 | kimage_file_prepare_segments(struct kimage *image, int kernel_fd, int initrd_fd, | |
195 | const char __user *cmdline_ptr, | |
196 | unsigned long cmdline_len, unsigned flags) | |
197 | { | |
f4da7afe | 198 | ssize_t ret; |
a43cac0d DY |
199 | void *ldata; |
200 | ||
0fa8e084 | 201 | ret = kernel_read_file_from_fd(kernel_fd, 0, &image->kernel_buf, |
f4da7afe PT |
202 | KEXEC_FILE_SIZE_MAX, NULL, |
203 | READING_KEXEC_IMAGE); | |
f7a4f689 | 204 | if (ret < 0) |
a43cac0d | 205 | return ret; |
f7a4f689 | 206 | image->kernel_buf_len = ret; |
a85ee18c BH |
207 | kexec_dprintk("kernel: %p kernel_size: %#lx\n", |
208 | image->kernel_buf, image->kernel_buf_len); | |
a43cac0d DY |
209 | |
210 | /* Call arch image probe handlers */ | |
211 | ret = arch_kexec_kernel_image_probe(image, image->kernel_buf, | |
212 | image->kernel_buf_len); | |
a43cac0d DY |
213 | if (ret) |
214 | goto out; | |
215 | ||
99d5cadf JB |
216 | #ifdef CONFIG_KEXEC_SIG |
217 | ret = kimage_validate_signature(image); | |
218 | ||
219 | if (ret) | |
a43cac0d | 220 | goto out; |
a43cac0d DY |
221 | #endif |
222 | /* It is possible that there no initramfs is being loaded */ | |
223 | if (!(flags & KEXEC_FILE_NO_INITRAMFS)) { | |
0fa8e084 | 224 | ret = kernel_read_file_from_fd(initrd_fd, 0, &image->initrd_buf, |
f4da7afe | 225 | KEXEC_FILE_SIZE_MAX, NULL, |
b804defe | 226 | READING_KEXEC_INITRAMFS); |
f7a4f689 | 227 | if (ret < 0) |
a43cac0d | 228 | goto out; |
f7a4f689 KC |
229 | image->initrd_buf_len = ret; |
230 | ret = 0; | |
a43cac0d DY |
231 | } |
232 | ||
233 | if (cmdline_len) { | |
a9bd8dfa AV |
234 | image->cmdline_buf = memdup_user(cmdline_ptr, cmdline_len); |
235 | if (IS_ERR(image->cmdline_buf)) { | |
236 | ret = PTR_ERR(image->cmdline_buf); | |
237 | image->cmdline_buf = NULL; | |
a43cac0d DY |
238 | goto out; |
239 | } | |
240 | ||
241 | image->cmdline_buf_len = cmdline_len; | |
242 | ||
243 | /* command line should be a string with last byte null */ | |
244 | if (image->cmdline_buf[cmdline_len - 1] != '\0') { | |
245 | ret = -EINVAL; | |
246 | goto out; | |
247 | } | |
6a31fcd4 | 248 | |
4834177e | 249 | ima_kexec_cmdline(kernel_fd, image->cmdline_buf, |
6a31fcd4 | 250 | image->cmdline_buf_len - 1); |
a43cac0d DY |
251 | } |
252 | ||
6a31fcd4 PS |
253 | /* IMA needs to pass the measurement list to the next kernel. */ |
254 | ima_add_kexec_buffer(image); | |
255 | ||
fb15abdc BH |
256 | /* Call image load handler */ |
257 | ldata = kexec_image_load_default(image); | |
a43cac0d DY |
258 | |
259 | if (IS_ERR(ldata)) { | |
260 | ret = PTR_ERR(ldata); | |
261 | goto out; | |
262 | } | |
263 | ||
264 | image->image_loader_data = ldata; | |
265 | out: | |
266 | /* In case of error, free up all allocated memory in this function */ | |
267 | if (ret) | |
268 | kimage_file_post_load_cleanup(image); | |
269 | return ret; | |
270 | } | |
271 | ||
272 | static int | |
273 | kimage_file_alloc_init(struct kimage **rimage, int kernel_fd, | |
274 | int initrd_fd, const char __user *cmdline_ptr, | |
275 | unsigned long cmdline_len, unsigned long flags) | |
276 | { | |
277 | int ret; | |
278 | struct kimage *image; | |
279 | bool kexec_on_panic = flags & KEXEC_FILE_ON_CRASH; | |
280 | ||
281 | image = do_kimage_alloc_init(); | |
282 | if (!image) | |
283 | return -ENOMEM; | |
284 | ||
cbc2fe9d | 285 | kexec_file_dbg_print = !!(flags & KEXEC_FILE_DEBUG); |
a43cac0d DY |
286 | image->file_mode = 1; |
287 | ||
02aff848 | 288 | #ifdef CONFIG_CRASH_DUMP |
a43cac0d DY |
289 | if (kexec_on_panic) { |
290 | /* Enable special crash kernel control page alloc policy. */ | |
291 | image->control_page = crashk_res.start; | |
292 | image->type = KEXEC_TYPE_CRASH; | |
293 | } | |
02aff848 | 294 | #endif |
a43cac0d DY |
295 | |
296 | ret = kimage_file_prepare_segments(image, kernel_fd, initrd_fd, | |
297 | cmdline_ptr, cmdline_len, flags); | |
298 | if (ret) | |
299 | goto out_free_image; | |
300 | ||
301 | ret = sanity_check_segment_list(image); | |
302 | if (ret) | |
303 | goto out_free_post_load_bufs; | |
304 | ||
305 | ret = -ENOMEM; | |
306 | image->control_code_page = kimage_alloc_control_pages(image, | |
307 | get_order(KEXEC_CONTROL_PAGE_SIZE)); | |
308 | if (!image->control_code_page) { | |
309 | pr_err("Could not allocate control_code_buffer\n"); | |
310 | goto out_free_post_load_bufs; | |
311 | } | |
312 | ||
313 | if (!kexec_on_panic) { | |
314 | image->swap_page = kimage_alloc_control_pages(image, 0); | |
315 | if (!image->swap_page) { | |
316 | pr_err("Could not allocate swap buffer\n"); | |
317 | goto out_free_control_pages; | |
318 | } | |
319 | } | |
320 | ||
321 | *rimage = image; | |
322 | return 0; | |
323 | out_free_control_pages: | |
324 | kimage_free_page_list(&image->control_pages); | |
325 | out_free_post_load_bufs: | |
326 | kimage_file_post_load_cleanup(image); | |
327 | out_free_image: | |
328 | kfree(image); | |
329 | return ret; | |
330 | } | |
331 | ||
332 | SYSCALL_DEFINE5(kexec_file_load, int, kernel_fd, int, initrd_fd, | |
333 | unsigned long, cmdline_len, const char __user *, cmdline_ptr, | |
334 | unsigned long, flags) | |
335 | { | |
a42aaad2 RR |
336 | int image_type = (flags & KEXEC_FILE_ON_CRASH) ? |
337 | KEXEC_TYPE_CRASH : KEXEC_TYPE_DEFAULT; | |
a43cac0d | 338 | struct kimage **dest_image, *image; |
a42aaad2 | 339 | int ret = 0, i; |
a43cac0d DY |
340 | |
341 | /* We only trust the superuser with rebooting the system. */ | |
a42aaad2 | 342 | if (!kexec_load_permitted(image_type)) |
a43cac0d DY |
343 | return -EPERM; |
344 | ||
345 | /* Make sure we have a legal set of flags */ | |
346 | if (flags != (flags & KEXEC_FILE_FLAGS)) | |
347 | return -EINVAL; | |
348 | ||
349 | image = NULL; | |
350 | ||
05c62574 | 351 | if (!kexec_trylock()) |
a43cac0d DY |
352 | return -EBUSY; |
353 | ||
02aff848 | 354 | #ifdef CONFIG_CRASH_DUMP |
a42aaad2 | 355 | if (image_type == KEXEC_TYPE_CRASH) { |
a43cac0d | 356 | dest_image = &kexec_crash_image; |
9b492cf5 XP |
357 | if (kexec_crash_image) |
358 | arch_kexec_unprotect_crashkres(); | |
02aff848 BH |
359 | } else |
360 | #endif | |
a42aaad2 | 361 | dest_image = &kexec_image; |
a43cac0d DY |
362 | |
363 | if (flags & KEXEC_FILE_UNLOAD) | |
364 | goto exchange; | |
365 | ||
366 | /* | |
367 | * In case of crash, new kernel gets loaded in reserved region. It is | |
368 | * same memory where old crash kernel might be loaded. Free any | |
369 | * current crash dump kernel before we corrupt it. | |
370 | */ | |
371 | if (flags & KEXEC_FILE_ON_CRASH) | |
372 | kimage_free(xchg(&kexec_crash_image, NULL)); | |
373 | ||
374 | ret = kimage_file_alloc_init(&image, kernel_fd, initrd_fd, cmdline_ptr, | |
375 | cmdline_len, flags); | |
376 | if (ret) | |
377 | goto out; | |
378 | ||
379 | ret = machine_kexec_prepare(image); | |
380 | if (ret) | |
381 | goto out; | |
382 | ||
1229384f XP |
383 | /* |
384 | * Some architecture(like S390) may touch the crash memory before | |
385 | * machine_kexec_prepare(), we must copy vmcoreinfo data after it. | |
386 | */ | |
387 | ret = kimage_crash_copy_vmcoreinfo(image); | |
388 | if (ret) | |
389 | goto out; | |
390 | ||
a43cac0d DY |
391 | ret = kexec_calculate_store_digests(image); |
392 | if (ret) | |
393 | goto out; | |
394 | ||
a85ee18c | 395 | kexec_dprintk("nr_segments = %lu\n", image->nr_segments); |
a43cac0d DY |
396 | for (i = 0; i < image->nr_segments; i++) { |
397 | struct kexec_segment *ksegment; | |
398 | ||
399 | ksegment = &image->segment[i]; | |
a85ee18c BH |
400 | kexec_dprintk("segment[%d]: buf=0x%p bufsz=0x%zx mem=0x%lx memsz=0x%zx\n", |
401 | i, ksegment->buf, ksegment->bufsz, ksegment->mem, | |
402 | ksegment->memsz); | |
a43cac0d DY |
403 | |
404 | ret = kimage_load_segment(image, &image->segment[i]); | |
405 | if (ret) | |
406 | goto out; | |
407 | } | |
408 | ||
409 | kimage_terminate(image); | |
410 | ||
de68e4da PT |
411 | ret = machine_kexec_post_load(image); |
412 | if (ret) | |
413 | goto out; | |
414 | ||
a85ee18c BH |
415 | kexec_dprintk("kexec_file_load: type:%u, start:0x%lx head:0x%lx flags:0x%lx\n", |
416 | image->type, image->start, image->head, flags); | |
a43cac0d DY |
417 | /* |
418 | * Free up any temporary buffers allocated which are not needed | |
419 | * after image has been loaded | |
420 | */ | |
421 | kimage_file_post_load_cleanup(image); | |
422 | exchange: | |
423 | image = xchg(dest_image, image); | |
424 | out: | |
02aff848 | 425 | #ifdef CONFIG_CRASH_DUMP |
9b492cf5 XP |
426 | if ((flags & KEXEC_FILE_ON_CRASH) && kexec_crash_image) |
427 | arch_kexec_protect_crashkres(); | |
02aff848 | 428 | #endif |
9b492cf5 | 429 | |
05c62574 | 430 | kexec_unlock(); |
a43cac0d DY |
431 | kimage_free(image); |
432 | return ret; | |
433 | } | |
434 | ||
435 | static int locate_mem_hole_top_down(unsigned long start, unsigned long end, | |
436 | struct kexec_buf *kbuf) | |
437 | { | |
438 | struct kimage *image = kbuf->image; | |
439 | unsigned long temp_start, temp_end; | |
440 | ||
441 | temp_end = min(end, kbuf->buf_max); | |
18d565ea | 442 | temp_start = temp_end - kbuf->memsz + 1; |
a43cac0d DY |
443 | |
444 | do { | |
445 | /* align down start */ | |
18d565ea | 446 | temp_start = ALIGN_DOWN(temp_start, kbuf->buf_align); |
a43cac0d DY |
447 | |
448 | if (temp_start < start || temp_start < kbuf->buf_min) | |
449 | return 0; | |
450 | ||
451 | temp_end = temp_start + kbuf->memsz - 1; | |
452 | ||
453 | /* | |
454 | * Make sure this does not conflict with any of existing | |
455 | * segments | |
456 | */ | |
457 | if (kimage_is_destination_range(image, temp_start, temp_end)) { | |
458 | temp_start = temp_start - PAGE_SIZE; | |
459 | continue; | |
460 | } | |
461 | ||
462 | /* We found a suitable memory range */ | |
463 | break; | |
464 | } while (1); | |
465 | ||
466 | /* If we are here, we found a suitable memory range */ | |
467 | kbuf->mem = temp_start; | |
468 | ||
469 | /* Success, stop navigating through remaining System RAM ranges */ | |
470 | return 1; | |
471 | } | |
472 | ||
473 | static int locate_mem_hole_bottom_up(unsigned long start, unsigned long end, | |
474 | struct kexec_buf *kbuf) | |
475 | { | |
476 | struct kimage *image = kbuf->image; | |
477 | unsigned long temp_start, temp_end; | |
478 | ||
479 | temp_start = max(start, kbuf->buf_min); | |
480 | ||
481 | do { | |
482 | temp_start = ALIGN(temp_start, kbuf->buf_align); | |
483 | temp_end = temp_start + kbuf->memsz - 1; | |
484 | ||
485 | if (temp_end > end || temp_end > kbuf->buf_max) | |
486 | return 0; | |
487 | /* | |
488 | * Make sure this does not conflict with any of existing | |
489 | * segments | |
490 | */ | |
491 | if (kimage_is_destination_range(image, temp_start, temp_end)) { | |
492 | temp_start = temp_start + PAGE_SIZE; | |
493 | continue; | |
494 | } | |
495 | ||
496 | /* We found a suitable memory range */ | |
497 | break; | |
498 | } while (1); | |
499 | ||
500 | /* If we are here, we found a suitable memory range */ | |
501 | kbuf->mem = temp_start; | |
502 | ||
503 | /* Success, stop navigating through remaining System RAM ranges */ | |
504 | return 1; | |
505 | } | |
506 | ||
1d2e733b | 507 | static int locate_mem_hole_callback(struct resource *res, void *arg) |
a43cac0d DY |
508 | { |
509 | struct kexec_buf *kbuf = (struct kexec_buf *)arg; | |
1d2e733b | 510 | u64 start = res->start, end = res->end; |
a43cac0d DY |
511 | unsigned long sz = end - start + 1; |
512 | ||
513 | /* Returning 0 will take to next memory range */ | |
3fe4f499 DH |
514 | |
515 | /* Don't use memory that will be detected and handled by a driver. */ | |
7cf603d1 | 516 | if (res->flags & IORESOURCE_SYSRAM_DRIVER_MANAGED) |
3fe4f499 DH |
517 | return 0; |
518 | ||
a43cac0d DY |
519 | if (sz < kbuf->memsz) |
520 | return 0; | |
521 | ||
522 | if (end < kbuf->buf_min || start > kbuf->buf_max) | |
523 | return 0; | |
524 | ||
525 | /* | |
526 | * Allocate memory top down with-in ram range. Otherwise bottom up | |
527 | * allocation. | |
528 | */ | |
529 | if (kbuf->top_down) | |
530 | return locate_mem_hole_top_down(start, end, kbuf); | |
531 | return locate_mem_hole_bottom_up(start, end, kbuf); | |
532 | } | |
533 | ||
350e88ba | 534 | #ifdef CONFIG_ARCH_KEEP_MEMBLOCK |
735c2f90 AT |
535 | static int kexec_walk_memblock(struct kexec_buf *kbuf, |
536 | int (*func)(struct resource *, void *)) | |
537 | { | |
538 | int ret = 0; | |
539 | u64 i; | |
540 | phys_addr_t mstart, mend; | |
541 | struct resource res = { }; | |
542 | ||
40254101 | 543 | #ifdef CONFIG_CRASH_DUMP |
497e1858 AT |
544 | if (kbuf->image->type == KEXEC_TYPE_CRASH) |
545 | return func(&crashk_res, kbuf); | |
40254101 | 546 | #endif |
497e1858 | 547 | |
f7892d8e DH |
548 | /* |
549 | * Using MEMBLOCK_NONE will properly skip MEMBLOCK_DRIVER_MANAGED. See | |
550 | * IORESOURCE_SYSRAM_DRIVER_MANAGED handling in | |
551 | * locate_mem_hole_callback(). | |
552 | */ | |
735c2f90 | 553 | if (kbuf->top_down) { |
497e1858 | 554 | for_each_free_mem_range_reverse(i, NUMA_NO_NODE, MEMBLOCK_NONE, |
735c2f90 AT |
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 { | |
497e1858 AT |
568 | for_each_free_mem_range(i, NUMA_NO_NODE, MEMBLOCK_NONE, |
569 | &mstart, &mend, NULL) { | |
735c2f90 AT |
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 | } | |
350e88ba MR |
585 | #else |
586 | static int kexec_walk_memblock(struct kexec_buf *kbuf, | |
587 | int (*func)(struct resource *, void *)) | |
588 | { | |
589 | return 0; | |
590 | } | |
735c2f90 AT |
591 | #endif |
592 | ||
60fe3910 | 593 | /** |
735c2f90 | 594 | * kexec_walk_resources - call func(data) on free memory regions |
60fe3910 TJB |
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 | */ | |
735c2f90 AT |
602 | static int kexec_walk_resources(struct kexec_buf *kbuf, |
603 | int (*func)(struct resource *, void *)) | |
60fe3910 | 604 | { |
02aff848 | 605 | #ifdef CONFIG_CRASH_DUMP |
60fe3910 TJB |
606 | if (kbuf->image->type == KEXEC_TYPE_CRASH) |
607 | return walk_iomem_res_desc(crashk_res.desc, | |
608 | IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY, | |
609 | crashk_res.start, crashk_res.end, | |
610 | kbuf, func); | |
02aff848 BH |
611 | #endif |
612 | if (kbuf->top_down) | |
b3ba2341 | 613 | return walk_system_ram_res_rev(0, ULONG_MAX, kbuf, func); |
60fe3910 TJB |
614 | else |
615 | return walk_system_ram_res(0, ULONG_MAX, kbuf, func); | |
616 | } | |
617 | ||
e2e806f9 TJB |
618 | /** |
619 | * kexec_locate_mem_hole - find free memory for the purgatory or the next kernel | |
620 | * @kbuf: Parameters for the memory search. | |
621 | * | |
622 | * On success, kbuf->mem will have the start address of the memory region found. | |
623 | * | |
624 | * Return: 0 on success, negative errno on error. | |
625 | */ | |
626 | int kexec_locate_mem_hole(struct kexec_buf *kbuf) | |
627 | { | |
628 | int ret; | |
629 | ||
b6664ba4 AT |
630 | /* Arch knows where to place */ |
631 | if (kbuf->mem != KEXEC_BUF_MEM_UNKNOWN) | |
632 | return 0; | |
633 | ||
350e88ba | 634 | if (!IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) |
735c2f90 AT |
635 | ret = kexec_walk_resources(kbuf, locate_mem_hole_callback); |
636 | else | |
637 | ret = kexec_walk_memblock(kbuf, locate_mem_hole_callback); | |
e2e806f9 TJB |
638 | |
639 | return ret == 1 ? 0 : -EADDRNOTAVAIL; | |
640 | } | |
641 | ||
ec2b9bfa TJB |
642 | /** |
643 | * kexec_add_buffer - place a buffer in a kexec segment | |
644 | * @kbuf: Buffer contents and memory parameters. | |
645 | * | |
55e2b696 | 646 | * This function assumes that kexec_lock is held. |
ec2b9bfa TJB |
647 | * On successful return, @kbuf->mem will have the physical address of |
648 | * the buffer in memory. | |
649 | * | |
650 | * Return: 0 on success, negative errno on error. | |
a43cac0d | 651 | */ |
ec2b9bfa | 652 | int kexec_add_buffer(struct kexec_buf *kbuf) |
a43cac0d | 653 | { |
a43cac0d | 654 | struct kexec_segment *ksegment; |
a43cac0d DY |
655 | int ret; |
656 | ||
657 | /* Currently adding segment this way is allowed only in file mode */ | |
ec2b9bfa | 658 | if (!kbuf->image->file_mode) |
a43cac0d DY |
659 | return -EINVAL; |
660 | ||
ec2b9bfa | 661 | if (kbuf->image->nr_segments >= KEXEC_SEGMENT_MAX) |
a43cac0d DY |
662 | return -EINVAL; |
663 | ||
664 | /* | |
665 | * Make sure we are not trying to add buffer after allocating | |
666 | * control pages. All segments need to be placed first before | |
667 | * any control pages are allocated. As control page allocation | |
668 | * logic goes through list of segments to make sure there are | |
669 | * no destination overlaps. | |
670 | */ | |
ec2b9bfa | 671 | if (!list_empty(&kbuf->image->control_pages)) { |
a43cac0d DY |
672 | WARN_ON(1); |
673 | return -EINVAL; | |
674 | } | |
675 | ||
ec2b9bfa TJB |
676 | /* Ensure minimum alignment needed for segments. */ |
677 | kbuf->memsz = ALIGN(kbuf->memsz, PAGE_SIZE); | |
678 | kbuf->buf_align = max(kbuf->buf_align, PAGE_SIZE); | |
a43cac0d DY |
679 | |
680 | /* Walk the RAM ranges and allocate a suitable range for the buffer */ | |
f891f197 | 681 | ret = arch_kexec_locate_mem_hole(kbuf); |
e2e806f9 TJB |
682 | if (ret) |
683 | return ret; | |
a43cac0d DY |
684 | |
685 | /* Found a suitable memory range */ | |
ec2b9bfa | 686 | ksegment = &kbuf->image->segment[kbuf->image->nr_segments]; |
a43cac0d DY |
687 | ksegment->kbuf = kbuf->buffer; |
688 | ksegment->bufsz = kbuf->bufsz; | |
689 | ksegment->mem = kbuf->mem; | |
690 | ksegment->memsz = kbuf->memsz; | |
ec2b9bfa | 691 | kbuf->image->nr_segments++; |
a43cac0d DY |
692 | return 0; |
693 | } | |
694 | ||
695 | /* Calculate and store the digest of segments */ | |
696 | static int kexec_calculate_store_digests(struct kimage *image) | |
697 | { | |
698 | struct crypto_shash *tfm; | |
699 | struct shash_desc *desc; | |
700 | int ret = 0, i, j, zero_buf_sz, sha_region_sz; | |
701 | size_t desc_size, nullsz; | |
702 | char *digest; | |
703 | void *zero_buf; | |
704 | struct kexec_sha_region *sha_regions; | |
705 | struct purgatory_info *pi = &image->purgatory_info; | |
706 | ||
e6265fe7 | 707 | if (!IS_ENABLED(CONFIG_ARCH_SUPPORTS_KEXEC_PURGATORY)) |
b799a09f AT |
708 | return 0; |
709 | ||
a43cac0d DY |
710 | zero_buf = __va(page_to_pfn(ZERO_PAGE(0)) << PAGE_SHIFT); |
711 | zero_buf_sz = PAGE_SIZE; | |
712 | ||
713 | tfm = crypto_alloc_shash("sha256", 0, 0); | |
714 | if (IS_ERR(tfm)) { | |
715 | ret = PTR_ERR(tfm); | |
716 | goto out; | |
717 | } | |
718 | ||
719 | desc_size = crypto_shash_descsize(tfm) + sizeof(*desc); | |
720 | desc = kzalloc(desc_size, GFP_KERNEL); | |
721 | if (!desc) { | |
722 | ret = -ENOMEM; | |
723 | goto out_free_tfm; | |
724 | } | |
725 | ||
726 | sha_region_sz = KEXEC_SEGMENT_MAX * sizeof(struct kexec_sha_region); | |
727 | sha_regions = vzalloc(sha_region_sz); | |
31d82c2c JJB |
728 | if (!sha_regions) { |
729 | ret = -ENOMEM; | |
a43cac0d | 730 | goto out_free_desc; |
31d82c2c | 731 | } |
a43cac0d DY |
732 | |
733 | desc->tfm = tfm; | |
a43cac0d DY |
734 | |
735 | ret = crypto_shash_init(desc); | |
736 | if (ret < 0) | |
737 | goto out_free_sha_regions; | |
738 | ||
739 | digest = kzalloc(SHA256_DIGEST_SIZE, GFP_KERNEL); | |
740 | if (!digest) { | |
741 | ret = -ENOMEM; | |
742 | goto out_free_sha_regions; | |
743 | } | |
744 | ||
745 | for (j = i = 0; i < image->nr_segments; i++) { | |
746 | struct kexec_segment *ksegment; | |
747 | ||
f7cc804a ED |
748 | #ifdef CONFIG_CRASH_HOTPLUG |
749 | /* Exclude elfcorehdr segment to allow future changes via hotplug */ | |
750 | if (j == image->elfcorehdr_index) | |
751 | continue; | |
752 | #endif | |
753 | ||
a43cac0d DY |
754 | ksegment = &image->segment[i]; |
755 | /* | |
756 | * Skip purgatory as it will be modified once we put digest | |
757 | * info in purgatory. | |
758 | */ | |
759 | if (ksegment->kbuf == pi->purgatory_buf) | |
760 | continue; | |
761 | ||
762 | ret = crypto_shash_update(desc, ksegment->kbuf, | |
763 | ksegment->bufsz); | |
764 | if (ret) | |
765 | break; | |
766 | ||
767 | /* | |
768 | * Assume rest of the buffer is filled with zero and | |
769 | * update digest accordingly. | |
770 | */ | |
771 | nullsz = ksegment->memsz - ksegment->bufsz; | |
772 | while (nullsz) { | |
773 | unsigned long bytes = nullsz; | |
774 | ||
775 | if (bytes > zero_buf_sz) | |
776 | bytes = zero_buf_sz; | |
777 | ret = crypto_shash_update(desc, zero_buf, bytes); | |
778 | if (ret) | |
779 | break; | |
780 | nullsz -= bytes; | |
781 | } | |
782 | ||
783 | if (ret) | |
784 | break; | |
785 | ||
786 | sha_regions[j].start = ksegment->mem; | |
787 | sha_regions[j].len = ksegment->memsz; | |
788 | j++; | |
789 | } | |
790 | ||
791 | if (!ret) { | |
792 | ret = crypto_shash_final(desc, digest); | |
793 | if (ret) | |
794 | goto out_free_digest; | |
40c50c1f TG |
795 | ret = kexec_purgatory_get_set_symbol(image, "purgatory_sha_regions", |
796 | sha_regions, sha_region_sz, 0); | |
a43cac0d DY |
797 | if (ret) |
798 | goto out_free_digest; | |
799 | ||
40c50c1f TG |
800 | ret = kexec_purgatory_get_set_symbol(image, "purgatory_sha256_digest", |
801 | digest, SHA256_DIGEST_SIZE, 0); | |
a43cac0d DY |
802 | if (ret) |
803 | goto out_free_digest; | |
804 | } | |
805 | ||
806 | out_free_digest: | |
807 | kfree(digest); | |
808 | out_free_sha_regions: | |
809 | vfree(sha_regions); | |
810 | out_free_desc: | |
811 | kfree(desc); | |
812 | out_free_tfm: | |
813 | kfree(tfm); | |
814 | out: | |
815 | return ret; | |
816 | } | |
817 | ||
e6265fe7 | 818 | #ifdef CONFIG_ARCH_SUPPORTS_KEXEC_PURGATORY |
93045705 PR |
819 | /* |
820 | * kexec_purgatory_setup_kbuf - prepare buffer to load purgatory. | |
821 | * @pi: Purgatory to be loaded. | |
822 | * @kbuf: Buffer to setup. | |
823 | * | |
824 | * Allocates the memory needed for the buffer. Caller is responsible to free | |
825 | * the memory after use. | |
826 | * | |
827 | * Return: 0 on success, negative errno on error. | |
828 | */ | |
829 | static int kexec_purgatory_setup_kbuf(struct purgatory_info *pi, | |
830 | struct kexec_buf *kbuf) | |
a43cac0d | 831 | { |
93045705 PR |
832 | const Elf_Shdr *sechdrs; |
833 | unsigned long bss_align; | |
834 | unsigned long bss_sz; | |
835 | unsigned long align; | |
836 | int i, ret; | |
a43cac0d | 837 | |
93045705 | 838 | sechdrs = (void *)pi->ehdr + pi->ehdr->e_shoff; |
3be3f61d PR |
839 | kbuf->buf_align = bss_align = 1; |
840 | kbuf->bufsz = bss_sz = 0; | |
93045705 PR |
841 | |
842 | for (i = 0; i < pi->ehdr->e_shnum; i++) { | |
843 | if (!(sechdrs[i].sh_flags & SHF_ALLOC)) | |
844 | continue; | |
845 | ||
846 | align = sechdrs[i].sh_addralign; | |
847 | if (sechdrs[i].sh_type != SHT_NOBITS) { | |
848 | if (kbuf->buf_align < align) | |
849 | kbuf->buf_align = align; | |
850 | kbuf->bufsz = ALIGN(kbuf->bufsz, align); | |
851 | kbuf->bufsz += sechdrs[i].sh_size; | |
852 | } else { | |
853 | if (bss_align < align) | |
854 | bss_align = align; | |
855 | bss_sz = ALIGN(bss_sz, align); | |
856 | bss_sz += sechdrs[i].sh_size; | |
857 | } | |
858 | } | |
859 | kbuf->bufsz = ALIGN(kbuf->bufsz, bss_align); | |
860 | kbuf->memsz = kbuf->bufsz + bss_sz; | |
861 | if (kbuf->buf_align < bss_align) | |
862 | kbuf->buf_align = bss_align; | |
863 | ||
864 | kbuf->buffer = vzalloc(kbuf->bufsz); | |
865 | if (!kbuf->buffer) | |
866 | return -ENOMEM; | |
867 | pi->purgatory_buf = kbuf->buffer; | |
868 | ||
869 | ret = kexec_add_buffer(kbuf); | |
870 | if (ret) | |
871 | goto out; | |
93045705 PR |
872 | |
873 | return 0; | |
874 | out: | |
875 | vfree(pi->purgatory_buf); | |
876 | pi->purgatory_buf = NULL; | |
877 | return ret; | |
878 | } | |
879 | ||
880 | /* | |
881 | * kexec_purgatory_setup_sechdrs - prepares the pi->sechdrs buffer. | |
882 | * @pi: Purgatory to be loaded. | |
883 | * @kbuf: Buffer prepared to store purgatory. | |
884 | * | |
885 | * Allocates the memory needed for the buffer. Caller is responsible to free | |
886 | * the memory after use. | |
887 | * | |
888 | * Return: 0 on success, negative errno on error. | |
889 | */ | |
890 | static int kexec_purgatory_setup_sechdrs(struct purgatory_info *pi, | |
891 | struct kexec_buf *kbuf) | |
892 | { | |
93045705 PR |
893 | unsigned long bss_addr; |
894 | unsigned long offset; | |
4df3504e | 895 | size_t sechdrs_size; |
93045705 | 896 | Elf_Shdr *sechdrs; |
93045705 | 897 | int i; |
a43cac0d | 898 | |
8da0b724 PR |
899 | /* |
900 | * The section headers in kexec_purgatory are read-only. In order to | |
901 | * have them modifiable make a temporary copy. | |
902 | */ | |
4df3504e SH |
903 | sechdrs_size = array_size(sizeof(Elf_Shdr), pi->ehdr->e_shnum); |
904 | sechdrs = vzalloc(sechdrs_size); | |
a43cac0d DY |
905 | if (!sechdrs) |
906 | return -ENOMEM; | |
4df3504e | 907 | memcpy(sechdrs, (void *)pi->ehdr + pi->ehdr->e_shoff, sechdrs_size); |
93045705 | 908 | pi->sechdrs = sechdrs; |
a43cac0d | 909 | |
620f697c PR |
910 | offset = 0; |
911 | bss_addr = kbuf->mem + kbuf->bufsz; | |
f1b1cca3 | 912 | kbuf->image->start = pi->ehdr->e_entry; |
a43cac0d DY |
913 | |
914 | for (i = 0; i < pi->ehdr->e_shnum; i++) { | |
93045705 | 915 | unsigned long align; |
620f697c | 916 | void *src, *dst; |
93045705 | 917 | |
a43cac0d DY |
918 | if (!(sechdrs[i].sh_flags & SHF_ALLOC)) |
919 | continue; | |
920 | ||
921 | align = sechdrs[i].sh_addralign; | |
f1b1cca3 | 922 | if (sechdrs[i].sh_type == SHT_NOBITS) { |
a43cac0d DY |
923 | bss_addr = ALIGN(bss_addr, align); |
924 | sechdrs[i].sh_addr = bss_addr; | |
925 | bss_addr += sechdrs[i].sh_size; | |
f1b1cca3 PR |
926 | continue; |
927 | } | |
928 | ||
620f697c | 929 | offset = ALIGN(offset, align); |
8652d44f RR |
930 | |
931 | /* | |
932 | * Check if the segment contains the entry point, if so, | |
933 | * calculate the value of image->start based on it. | |
934 | * If the compiler has produced more than one .text section | |
935 | * (Eg: .text.hot), they are generally after the main .text | |
936 | * section, and they shall not be used to calculate | |
937 | * image->start. So do not re-calculate image->start if it | |
938 | * is not set to the initial value, and warn the user so they | |
939 | * have a chance to fix their purgatory's linker script. | |
940 | */ | |
f1b1cca3 PR |
941 | if (sechdrs[i].sh_flags & SHF_EXECINSTR && |
942 | pi->ehdr->e_entry >= sechdrs[i].sh_addr && | |
943 | pi->ehdr->e_entry < (sechdrs[i].sh_addr | |
8652d44f RR |
944 | + sechdrs[i].sh_size) && |
945 | !WARN_ON(kbuf->image->start != pi->ehdr->e_entry)) { | |
f1b1cca3 | 946 | kbuf->image->start -= sechdrs[i].sh_addr; |
620f697c | 947 | kbuf->image->start += kbuf->mem + offset; |
a43cac0d | 948 | } |
a43cac0d | 949 | |
8da0b724 | 950 | src = (void *)pi->ehdr + sechdrs[i].sh_offset; |
620f697c PR |
951 | dst = pi->purgatory_buf + offset; |
952 | memcpy(dst, src, sechdrs[i].sh_size); | |
953 | ||
954 | sechdrs[i].sh_addr = kbuf->mem + offset; | |
8da0b724 | 955 | sechdrs[i].sh_offset = offset; |
620f697c | 956 | offset += sechdrs[i].sh_size; |
f1b1cca3 | 957 | } |
a43cac0d | 958 | |
93045705 | 959 | return 0; |
a43cac0d DY |
960 | } |
961 | ||
962 | static int kexec_apply_relocations(struct kimage *image) | |
963 | { | |
964 | int i, ret; | |
965 | struct purgatory_info *pi = &image->purgatory_info; | |
8aec395b PR |
966 | const Elf_Shdr *sechdrs; |
967 | ||
968 | sechdrs = (void *)pi->ehdr + pi->ehdr->e_shoff; | |
a43cac0d | 969 | |
a43cac0d | 970 | for (i = 0; i < pi->ehdr->e_shnum; i++) { |
8aec395b PR |
971 | const Elf_Shdr *relsec; |
972 | const Elf_Shdr *symtab; | |
973 | Elf_Shdr *section; | |
974 | ||
975 | relsec = sechdrs + i; | |
a43cac0d | 976 | |
8aec395b PR |
977 | if (relsec->sh_type != SHT_RELA && |
978 | relsec->sh_type != SHT_REL) | |
a43cac0d DY |
979 | continue; |
980 | ||
981 | /* | |
982 | * For section of type SHT_RELA/SHT_REL, | |
983 | * ->sh_link contains section header index of associated | |
984 | * symbol table. And ->sh_info contains section header | |
985 | * index of section to which relocations apply. | |
986 | */ | |
8aec395b PR |
987 | if (relsec->sh_info >= pi->ehdr->e_shnum || |
988 | relsec->sh_link >= pi->ehdr->e_shnum) | |
a43cac0d DY |
989 | return -ENOEXEC; |
990 | ||
8aec395b PR |
991 | section = pi->sechdrs + relsec->sh_info; |
992 | symtab = sechdrs + relsec->sh_link; | |
a43cac0d DY |
993 | |
994 | if (!(section->sh_flags & SHF_ALLOC)) | |
995 | continue; | |
996 | ||
997 | /* | |
998 | * symtab->sh_link contain section header index of associated | |
999 | * string table. | |
1000 | */ | |
1001 | if (symtab->sh_link >= pi->ehdr->e_shnum) | |
1002 | /* Invalid section number? */ | |
1003 | continue; | |
1004 | ||
1005 | /* | |
1006 | * Respective architecture needs to provide support for applying | |
1007 | * relocations of type SHT_RELA/SHT_REL. | |
1008 | */ | |
8aec395b PR |
1009 | if (relsec->sh_type == SHT_RELA) |
1010 | ret = arch_kexec_apply_relocations_add(pi, section, | |
1011 | relsec, symtab); | |
1012 | else if (relsec->sh_type == SHT_REL) | |
1013 | ret = arch_kexec_apply_relocations(pi, section, | |
1014 | relsec, symtab); | |
a43cac0d DY |
1015 | if (ret) |
1016 | return ret; | |
1017 | } | |
1018 | ||
1019 | return 0; | |
1020 | } | |
1021 | ||
3be3f61d PR |
1022 | /* |
1023 | * kexec_load_purgatory - Load and relocate the purgatory object. | |
1024 | * @image: Image to add the purgatory to. | |
1025 | * @kbuf: Memory parameters to use. | |
1026 | * | |
1027 | * Allocates the memory needed for image->purgatory_info.sechdrs and | |
1028 | * image->purgatory_info.purgatory_buf/kbuf->buffer. Caller is responsible | |
1029 | * to free the memory after use. | |
1030 | * | |
1031 | * Return: 0 on success, negative errno on error. | |
1032 | */ | |
1033 | int kexec_load_purgatory(struct kimage *image, struct kexec_buf *kbuf) | |
a43cac0d DY |
1034 | { |
1035 | struct purgatory_info *pi = &image->purgatory_info; | |
1036 | int ret; | |
1037 | ||
1038 | if (kexec_purgatory_size <= 0) | |
1039 | return -EINVAL; | |
1040 | ||
65c225d3 | 1041 | pi->ehdr = (const Elf_Ehdr *)kexec_purgatory; |
a43cac0d | 1042 | |
3be3f61d | 1043 | ret = kexec_purgatory_setup_kbuf(pi, kbuf); |
a43cac0d DY |
1044 | if (ret) |
1045 | return ret; | |
1046 | ||
3be3f61d | 1047 | ret = kexec_purgatory_setup_sechdrs(pi, kbuf); |
93045705 PR |
1048 | if (ret) |
1049 | goto out_free_kbuf; | |
1050 | ||
a43cac0d DY |
1051 | ret = kexec_apply_relocations(image); |
1052 | if (ret) | |
1053 | goto out; | |
1054 | ||
a43cac0d DY |
1055 | return 0; |
1056 | out: | |
1057 | vfree(pi->sechdrs); | |
070c43ee | 1058 | pi->sechdrs = NULL; |
93045705 | 1059 | out_free_kbuf: |
a43cac0d | 1060 | vfree(pi->purgatory_buf); |
070c43ee | 1061 | pi->purgatory_buf = NULL; |
a43cac0d DY |
1062 | return ret; |
1063 | } | |
1064 | ||
961d921a PR |
1065 | /* |
1066 | * kexec_purgatory_find_symbol - find a symbol in the purgatory | |
1067 | * @pi: Purgatory to search in. | |
1068 | * @name: Name of the symbol. | |
1069 | * | |
1070 | * Return: pointer to symbol in read-only symtab on success, NULL on error. | |
1071 | */ | |
1072 | static const Elf_Sym *kexec_purgatory_find_symbol(struct purgatory_info *pi, | |
1073 | const char *name) | |
a43cac0d | 1074 | { |
961d921a | 1075 | const Elf_Shdr *sechdrs; |
65c225d3 | 1076 | const Elf_Ehdr *ehdr; |
961d921a | 1077 | const Elf_Sym *syms; |
a43cac0d | 1078 | const char *strtab; |
961d921a | 1079 | int i, k; |
a43cac0d | 1080 | |
961d921a | 1081 | if (!pi->ehdr) |
a43cac0d DY |
1082 | return NULL; |
1083 | ||
a43cac0d | 1084 | ehdr = pi->ehdr; |
961d921a | 1085 | sechdrs = (void *)ehdr + ehdr->e_shoff; |
a43cac0d DY |
1086 | |
1087 | for (i = 0; i < ehdr->e_shnum; i++) { | |
1088 | if (sechdrs[i].sh_type != SHT_SYMTAB) | |
1089 | continue; | |
1090 | ||
1091 | if (sechdrs[i].sh_link >= ehdr->e_shnum) | |
1092 | /* Invalid strtab section number */ | |
1093 | continue; | |
961d921a PR |
1094 | strtab = (void *)ehdr + sechdrs[sechdrs[i].sh_link].sh_offset; |
1095 | syms = (void *)ehdr + sechdrs[i].sh_offset; | |
a43cac0d DY |
1096 | |
1097 | /* Go through symbols for a match */ | |
1098 | for (k = 0; k < sechdrs[i].sh_size/sizeof(Elf_Sym); k++) { | |
1099 | if (ELF_ST_BIND(syms[k].st_info) != STB_GLOBAL) | |
1100 | continue; | |
1101 | ||
1102 | if (strcmp(strtab + syms[k].st_name, name) != 0) | |
1103 | continue; | |
1104 | ||
1105 | if (syms[k].st_shndx == SHN_UNDEF || | |
1106 | syms[k].st_shndx >= ehdr->e_shnum) { | |
1107 | pr_debug("Symbol: %s has bad section index %d.\n", | |
1108 | name, syms[k].st_shndx); | |
1109 | return NULL; | |
1110 | } | |
1111 | ||
1112 | /* Found the symbol we are looking for */ | |
1113 | return &syms[k]; | |
1114 | } | |
1115 | } | |
1116 | ||
1117 | return NULL; | |
1118 | } | |
1119 | ||
1120 | void *kexec_purgatory_get_symbol_addr(struct kimage *image, const char *name) | |
1121 | { | |
1122 | struct purgatory_info *pi = &image->purgatory_info; | |
961d921a | 1123 | const Elf_Sym *sym; |
a43cac0d DY |
1124 | Elf_Shdr *sechdr; |
1125 | ||
1126 | sym = kexec_purgatory_find_symbol(pi, name); | |
1127 | if (!sym) | |
1128 | return ERR_PTR(-EINVAL); | |
1129 | ||
1130 | sechdr = &pi->sechdrs[sym->st_shndx]; | |
1131 | ||
1132 | /* | |
1133 | * Returns the address where symbol will finally be loaded after | |
1134 | * kexec_load_segment() | |
1135 | */ | |
1136 | return (void *)(sechdr->sh_addr + sym->st_value); | |
1137 | } | |
1138 | ||
1139 | /* | |
1140 | * Get or set value of a symbol. If "get_value" is true, symbol value is | |
1141 | * returned in buf otherwise symbol value is set based on value in buf. | |
1142 | */ | |
1143 | int kexec_purgatory_get_set_symbol(struct kimage *image, const char *name, | |
1144 | void *buf, unsigned int size, bool get_value) | |
1145 | { | |
a43cac0d | 1146 | struct purgatory_info *pi = &image->purgatory_info; |
961d921a PR |
1147 | const Elf_Sym *sym; |
1148 | Elf_Shdr *sec; | |
a43cac0d DY |
1149 | char *sym_buf; |
1150 | ||
1151 | sym = kexec_purgatory_find_symbol(pi, name); | |
1152 | if (!sym) | |
1153 | return -EINVAL; | |
1154 | ||
1155 | if (sym->st_size != size) { | |
1156 | pr_err("symbol %s size mismatch: expected %lu actual %u\n", | |
1157 | name, (unsigned long)sym->st_size, size); | |
1158 | return -EINVAL; | |
1159 | } | |
1160 | ||
961d921a | 1161 | sec = pi->sechdrs + sym->st_shndx; |
a43cac0d | 1162 | |
961d921a | 1163 | if (sec->sh_type == SHT_NOBITS) { |
a43cac0d DY |
1164 | pr_err("symbol %s is in a bss section. Cannot %s\n", name, |
1165 | get_value ? "get" : "set"); | |
1166 | return -EINVAL; | |
1167 | } | |
1168 | ||
8da0b724 | 1169 | sym_buf = (char *)pi->purgatory_buf + sec->sh_offset + sym->st_value; |
a43cac0d DY |
1170 | |
1171 | if (get_value) | |
1172 | memcpy((void *)buf, sym_buf, size); | |
1173 | else | |
1174 | memcpy((void *)sym_buf, buf, size); | |
1175 | ||
1176 | return 0; | |
1177 | } | |
e6265fe7 | 1178 | #endif /* CONFIG_ARCH_SUPPORTS_KEXEC_PURGATORY */ |