Merge tag 'arm-dt-6.0' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc
[linux-2.6-microblaze.git] / kernel / kexec_file.c
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/sha2.h>
24 #include <linux/elf.h>
25 #include <linux/elfcore.h>
26 #include <linux/kernel.h>
27 #include <linux/kernel_read_file.h>
28 #include <linux/syscalls.h>
29 #include <linux/vmalloc.h>
30 #include "kexec_internal.h"
31
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
41 static int kexec_calculate_store_digests(struct kimage *image);
42
43 /*
44  * Currently this is the only default function that is exported as some
45  * architectures need it to do additional handlings.
46  * In the future, other default functions may be exported too if required.
47  */
48 int kexec_image_probe_default(struct kimage *image, void *buf,
49                               unsigned long buf_len)
50 {
51         const struct kexec_file_ops * const *fops;
52         int ret = -ENOEXEC;
53
54         for (fops = &kexec_file_loaders[0]; *fops && (*fops)->probe; ++fops) {
55                 ret = (*fops)->probe(buf, buf_len);
56                 if (!ret) {
57                         image->fops = *fops;
58                         return ret;
59                 }
60         }
61
62         return ret;
63 }
64
65 /* Architectures can provide this probe function */
66 int __weak arch_kexec_kernel_image_probe(struct kimage *image, void *buf,
67                                          unsigned long buf_len)
68 {
69         return kexec_image_probe_default(image, buf, buf_len);
70 }
71
72 static void *kexec_image_load_default(struct kimage *image)
73 {
74         if (!image->fops || !image->fops->load)
75                 return ERR_PTR(-ENOEXEC);
76
77         return image->fops->load(image, image->kernel_buf,
78                                  image->kernel_buf_len, image->initrd_buf,
79                                  image->initrd_buf_len, image->cmdline_buf,
80                                  image->cmdline_buf_len);
81 }
82
83 void * __weak arch_kexec_kernel_image_load(struct kimage *image)
84 {
85         return kexec_image_load_default(image);
86 }
87
88 int kexec_image_post_load_cleanup_default(struct kimage *image)
89 {
90         if (!image->fops || !image->fops->cleanup)
91                 return 0;
92
93         return image->fops->cleanup(image->image_loader_data);
94 }
95
96 int __weak arch_kimage_file_post_load_cleanup(struct kimage *image)
97 {
98         return kexec_image_post_load_cleanup_default(image);
99 }
100
101 #ifdef CONFIG_KEXEC_SIG
102 static int kexec_image_verify_sig_default(struct kimage *image, void *buf,
103                                           unsigned long buf_len)
104 {
105         if (!image->fops || !image->fops->verify_sig) {
106                 pr_debug("kernel loader does not support signature verification.\n");
107                 return -EKEYREJECTED;
108         }
109
110         return image->fops->verify_sig(buf, buf_len);
111 }
112
113 int __weak arch_kexec_kernel_verify_sig(struct kimage *image, void *buf,
114                                         unsigned long buf_len)
115 {
116         return kexec_image_verify_sig_default(image, buf, buf_len);
117 }
118 #endif
119
120 /*
121  * Free up memory used by kernel, initrd, and command line. This is temporary
122  * memory allocation which is not needed any more after these buffers have
123  * been loaded into separate segments and have been copied elsewhere.
124  */
125 void kimage_file_post_load_cleanup(struct kimage *image)
126 {
127         struct purgatory_info *pi = &image->purgatory_info;
128
129         vfree(image->kernel_buf);
130         image->kernel_buf = NULL;
131
132         vfree(image->initrd_buf);
133         image->initrd_buf = NULL;
134
135         kfree(image->cmdline_buf);
136         image->cmdline_buf = NULL;
137
138         vfree(pi->purgatory_buf);
139         pi->purgatory_buf = NULL;
140
141         vfree(pi->sechdrs);
142         pi->sechdrs = NULL;
143
144 #ifdef CONFIG_IMA_KEXEC
145         vfree(image->ima_buffer);
146         image->ima_buffer = NULL;
147 #endif /* CONFIG_IMA_KEXEC */
148
149         /* See if architecture has anything to cleanup post load */
150         arch_kimage_file_post_load_cleanup(image);
151
152         /*
153          * Above call should have called into bootloader to free up
154          * any data stored in kimage->image_loader_data. It should
155          * be ok now to free it up.
156          */
157         kfree(image->image_loader_data);
158         image->image_loader_data = NULL;
159 }
160
161 #ifdef CONFIG_KEXEC_SIG
162 static int
163 kimage_validate_signature(struct kimage *image)
164 {
165         int ret;
166
167         ret = arch_kexec_kernel_verify_sig(image, image->kernel_buf,
168                                            image->kernel_buf_len);
169         if (ret) {
170
171                 if (sig_enforce) {
172                         pr_notice("Enforced kernel signature verification failed (%d).\n", ret);
173                         return ret;
174                 }
175
176                 /*
177                  * If IMA is guaranteed to appraise a signature on the kexec
178                  * image, permit it even if the kernel is otherwise locked
179                  * down.
180                  */
181                 if (!ima_appraise_signature(READING_KEXEC_IMAGE) &&
182                     security_locked_down(LOCKDOWN_KEXEC))
183                         return -EPERM;
184
185                 pr_debug("kernel signature verification failed (%d).\n", ret);
186         }
187
188         return 0;
189 }
190 #endif
191
192 /*
193  * In file mode list of segments is prepared by kernel. Copy relevant
194  * data from user space, do error checking, prepare segment list
195  */
196 static int
197 kimage_file_prepare_segments(struct kimage *image, int kernel_fd, int initrd_fd,
198                              const char __user *cmdline_ptr,
199                              unsigned long cmdline_len, unsigned flags)
200 {
201         int ret;
202         void *ldata;
203
204         ret = kernel_read_file_from_fd(kernel_fd, 0, &image->kernel_buf,
205                                        INT_MAX, NULL, READING_KEXEC_IMAGE);
206         if (ret < 0)
207                 return ret;
208         image->kernel_buf_len = ret;
209
210         /* Call arch image probe handlers */
211         ret = arch_kexec_kernel_image_probe(image, image->kernel_buf,
212                                             image->kernel_buf_len);
213         if (ret)
214                 goto out;
215
216 #ifdef CONFIG_KEXEC_SIG
217         ret = kimage_validate_signature(image);
218
219         if (ret)
220                 goto out;
221 #endif
222         /* It is possible that there no initramfs is being loaded */
223         if (!(flags & KEXEC_FILE_NO_INITRAMFS)) {
224                 ret = kernel_read_file_from_fd(initrd_fd, 0, &image->initrd_buf,
225                                                INT_MAX, NULL,
226                                                READING_KEXEC_INITRAMFS);
227                 if (ret < 0)
228                         goto out;
229                 image->initrd_buf_len = ret;
230                 ret = 0;
231         }
232
233         if (cmdline_len) {
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;
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                 }
248
249                 ima_kexec_cmdline(kernel_fd, image->cmdline_buf,
250                                   image->cmdline_buf_len - 1);
251         }
252
253         /* IMA needs to pass the measurement list to the next kernel. */
254         ima_add_kexec_buffer(image);
255
256         /* Call arch image load handlers */
257         ldata = arch_kexec_kernel_image_load(image);
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
285         image->file_mode = 1;
286
287         if (kexec_on_panic) {
288                 /* Enable special crash kernel control page alloc policy. */
289                 image->control_page = crashk_res.start;
290                 image->type = KEXEC_TYPE_CRASH;
291         }
292
293         ret = kimage_file_prepare_segments(image, kernel_fd, initrd_fd,
294                                            cmdline_ptr, cmdline_len, flags);
295         if (ret)
296                 goto out_free_image;
297
298         ret = sanity_check_segment_list(image);
299         if (ret)
300                 goto out_free_post_load_bufs;
301
302         ret = -ENOMEM;
303         image->control_code_page = kimage_alloc_control_pages(image,
304                                            get_order(KEXEC_CONTROL_PAGE_SIZE));
305         if (!image->control_code_page) {
306                 pr_err("Could not allocate control_code_buffer\n");
307                 goto out_free_post_load_bufs;
308         }
309
310         if (!kexec_on_panic) {
311                 image->swap_page = kimage_alloc_control_pages(image, 0);
312                 if (!image->swap_page) {
313                         pr_err("Could not allocate swap buffer\n");
314                         goto out_free_control_pages;
315                 }
316         }
317
318         *rimage = image;
319         return 0;
320 out_free_control_pages:
321         kimage_free_page_list(&image->control_pages);
322 out_free_post_load_bufs:
323         kimage_file_post_load_cleanup(image);
324 out_free_image:
325         kfree(image);
326         return ret;
327 }
328
329 SYSCALL_DEFINE5(kexec_file_load, int, kernel_fd, int, initrd_fd,
330                 unsigned long, cmdline_len, const char __user *, cmdline_ptr,
331                 unsigned long, flags)
332 {
333         int ret = 0, i;
334         struct kimage **dest_image, *image;
335
336         /* We only trust the superuser with rebooting the system. */
337         if (!capable(CAP_SYS_BOOT) || kexec_load_disabled)
338                 return -EPERM;
339
340         /* Make sure we have a legal set of flags */
341         if (flags != (flags & KEXEC_FILE_FLAGS))
342                 return -EINVAL;
343
344         image = NULL;
345
346         if (!mutex_trylock(&kexec_mutex))
347                 return -EBUSY;
348
349         dest_image = &kexec_image;
350         if (flags & KEXEC_FILE_ON_CRASH) {
351                 dest_image = &kexec_crash_image;
352                 if (kexec_crash_image)
353                         arch_kexec_unprotect_crashkres();
354         }
355
356         if (flags & KEXEC_FILE_UNLOAD)
357                 goto exchange;
358
359         /*
360          * In case of crash, new kernel gets loaded in reserved region. It is
361          * same memory where old crash kernel might be loaded. Free any
362          * current crash dump kernel before we corrupt it.
363          */
364         if (flags & KEXEC_FILE_ON_CRASH)
365                 kimage_free(xchg(&kexec_crash_image, NULL));
366
367         ret = kimage_file_alloc_init(&image, kernel_fd, initrd_fd, cmdline_ptr,
368                                      cmdline_len, flags);
369         if (ret)
370                 goto out;
371
372         ret = machine_kexec_prepare(image);
373         if (ret)
374                 goto out;
375
376         /*
377          * Some architecture(like S390) may touch the crash memory before
378          * machine_kexec_prepare(), we must copy vmcoreinfo data after it.
379          */
380         ret = kimage_crash_copy_vmcoreinfo(image);
381         if (ret)
382                 goto out;
383
384         ret = kexec_calculate_store_digests(image);
385         if (ret)
386                 goto out;
387
388         for (i = 0; i < image->nr_segments; i++) {
389                 struct kexec_segment *ksegment;
390
391                 ksegment = &image->segment[i];
392                 pr_debug("Loading segment %d: buf=0x%p bufsz=0x%zx mem=0x%lx memsz=0x%zx\n",
393                          i, ksegment->buf, ksegment->bufsz, ksegment->mem,
394                          ksegment->memsz);
395
396                 ret = kimage_load_segment(image, &image->segment[i]);
397                 if (ret)
398                         goto out;
399         }
400
401         kimage_terminate(image);
402
403         ret = machine_kexec_post_load(image);
404         if (ret)
405                 goto out;
406
407         /*
408          * Free up any temporary buffers allocated which are not needed
409          * after image has been loaded
410          */
411         kimage_file_post_load_cleanup(image);
412 exchange:
413         image = xchg(dest_image, image);
414 out:
415         if ((flags & KEXEC_FILE_ON_CRASH) && kexec_crash_image)
416                 arch_kexec_protect_crashkres();
417
418         mutex_unlock(&kexec_mutex);
419         kimage_free(image);
420         return ret;
421 }
422
423 static int locate_mem_hole_top_down(unsigned long start, unsigned long end,
424                                     struct kexec_buf *kbuf)
425 {
426         struct kimage *image = kbuf->image;
427         unsigned long temp_start, temp_end;
428
429         temp_end = min(end, kbuf->buf_max);
430         temp_start = temp_end - kbuf->memsz;
431
432         do {
433                 /* align down start */
434                 temp_start = temp_start & (~(kbuf->buf_align - 1));
435
436                 if (temp_start < start || temp_start < kbuf->buf_min)
437                         return 0;
438
439                 temp_end = temp_start + kbuf->memsz - 1;
440
441                 /*
442                  * Make sure this does not conflict with any of existing
443                  * segments
444                  */
445                 if (kimage_is_destination_range(image, temp_start, temp_end)) {
446                         temp_start = temp_start - PAGE_SIZE;
447                         continue;
448                 }
449
450                 /* We found a suitable memory range */
451                 break;
452         } while (1);
453
454         /* If we are here, we found a suitable memory range */
455         kbuf->mem = temp_start;
456
457         /* Success, stop navigating through remaining System RAM ranges */
458         return 1;
459 }
460
461 static int locate_mem_hole_bottom_up(unsigned long start, unsigned long end,
462                                      struct kexec_buf *kbuf)
463 {
464         struct kimage *image = kbuf->image;
465         unsigned long temp_start, temp_end;
466
467         temp_start = max(start, kbuf->buf_min);
468
469         do {
470                 temp_start = ALIGN(temp_start, kbuf->buf_align);
471                 temp_end = temp_start + kbuf->memsz - 1;
472
473                 if (temp_end > end || temp_end > kbuf->buf_max)
474                         return 0;
475                 /*
476                  * Make sure this does not conflict with any of existing
477                  * segments
478                  */
479                 if (kimage_is_destination_range(image, temp_start, temp_end)) {
480                         temp_start = temp_start + PAGE_SIZE;
481                         continue;
482                 }
483
484                 /* We found a suitable memory range */
485                 break;
486         } while (1);
487
488         /* If we are here, we found a suitable memory range */
489         kbuf->mem = temp_start;
490
491         /* Success, stop navigating through remaining System RAM ranges */
492         return 1;
493 }
494
495 static int locate_mem_hole_callback(struct resource *res, void *arg)
496 {
497         struct kexec_buf *kbuf = (struct kexec_buf *)arg;
498         u64 start = res->start, end = res->end;
499         unsigned long sz = end - start + 1;
500
501         /* Returning 0 will take to next memory range */
502
503         /* Don't use memory that will be detected and handled by a driver. */
504         if (res->flags & IORESOURCE_SYSRAM_DRIVER_MANAGED)
505                 return 0;
506
507         if (sz < kbuf->memsz)
508                 return 0;
509
510         if (end < kbuf->buf_min || start > kbuf->buf_max)
511                 return 0;
512
513         /*
514          * Allocate memory top down with-in ram range. Otherwise bottom up
515          * allocation.
516          */
517         if (kbuf->top_down)
518                 return locate_mem_hole_top_down(start, end, kbuf);
519         return locate_mem_hole_bottom_up(start, end, kbuf);
520 }
521
522 #ifdef CONFIG_ARCH_KEEP_MEMBLOCK
523 static int kexec_walk_memblock(struct kexec_buf *kbuf,
524                                int (*func)(struct resource *, void *))
525 {
526         int ret = 0;
527         u64 i;
528         phys_addr_t mstart, mend;
529         struct resource res = { };
530
531         if (kbuf->image->type == KEXEC_TYPE_CRASH)
532                 return func(&crashk_res, kbuf);
533
534         /*
535          * Using MEMBLOCK_NONE will properly skip MEMBLOCK_DRIVER_MANAGED. See
536          * IORESOURCE_SYSRAM_DRIVER_MANAGED handling in
537          * locate_mem_hole_callback().
538          */
539         if (kbuf->top_down) {
540                 for_each_free_mem_range_reverse(i, NUMA_NO_NODE, MEMBLOCK_NONE,
541                                                 &mstart, &mend, NULL) {
542                         /*
543                          * In memblock, end points to the first byte after the
544                          * range while in kexec, end points to the last byte
545                          * in the range.
546                          */
547                         res.start = mstart;
548                         res.end = mend - 1;
549                         ret = func(&res, kbuf);
550                         if (ret)
551                                 break;
552                 }
553         } else {
554                 for_each_free_mem_range(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         }
568
569         return ret;
570 }
571 #else
572 static int kexec_walk_memblock(struct kexec_buf *kbuf,
573                                int (*func)(struct resource *, void *))
574 {
575         return 0;
576 }
577 #endif
578
579 /**
580  * kexec_walk_resources - call func(data) on free memory regions
581  * @kbuf:       Context info for the search. Also passed to @func.
582  * @func:       Function to call for each memory region.
583  *
584  * Return: The memory walk will stop when func returns a non-zero value
585  * and that value will be returned. If all free regions are visited without
586  * func returning non-zero, then zero will be returned.
587  */
588 static int kexec_walk_resources(struct kexec_buf *kbuf,
589                                 int (*func)(struct resource *, void *))
590 {
591         if (kbuf->image->type == KEXEC_TYPE_CRASH)
592                 return walk_iomem_res_desc(crashk_res.desc,
593                                            IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY,
594                                            crashk_res.start, crashk_res.end,
595                                            kbuf, func);
596         else
597                 return walk_system_ram_res(0, ULONG_MAX, kbuf, func);
598 }
599
600 /**
601  * kexec_locate_mem_hole - find free memory for the purgatory or the next kernel
602  * @kbuf:       Parameters for the memory search.
603  *
604  * On success, kbuf->mem will have the start address of the memory region found.
605  *
606  * Return: 0 on success, negative errno on error.
607  */
608 int kexec_locate_mem_hole(struct kexec_buf *kbuf)
609 {
610         int ret;
611
612         /* Arch knows where to place */
613         if (kbuf->mem != KEXEC_BUF_MEM_UNKNOWN)
614                 return 0;
615
616         if (!IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK))
617                 ret = kexec_walk_resources(kbuf, locate_mem_hole_callback);
618         else
619                 ret = kexec_walk_memblock(kbuf, locate_mem_hole_callback);
620
621         return ret == 1 ? 0 : -EADDRNOTAVAIL;
622 }
623
624 /**
625  * arch_kexec_locate_mem_hole - Find free memory to place the segments.
626  * @kbuf:                       Parameters for the memory search.
627  *
628  * On success, kbuf->mem will have the start address of the memory region found.
629  *
630  * Return: 0 on success, negative errno on error.
631  */
632 int __weak arch_kexec_locate_mem_hole(struct kexec_buf *kbuf)
633 {
634         return kexec_locate_mem_hole(kbuf);
635 }
636
637 /**
638  * kexec_add_buffer - place a buffer in a kexec segment
639  * @kbuf:       Buffer contents and memory parameters.
640  *
641  * This function assumes that kexec_mutex is held.
642  * On successful return, @kbuf->mem will have the physical address of
643  * the buffer in memory.
644  *
645  * Return: 0 on success, negative errno on error.
646  */
647 int kexec_add_buffer(struct kexec_buf *kbuf)
648 {
649         struct kexec_segment *ksegment;
650         int ret;
651
652         /* Currently adding segment this way is allowed only in file mode */
653         if (!kbuf->image->file_mode)
654                 return -EINVAL;
655
656         if (kbuf->image->nr_segments >= KEXEC_SEGMENT_MAX)
657                 return -EINVAL;
658
659         /*
660          * Make sure we are not trying to add buffer after allocating
661          * control pages. All segments need to be placed first before
662          * any control pages are allocated. As control page allocation
663          * logic goes through list of segments to make sure there are
664          * no destination overlaps.
665          */
666         if (!list_empty(&kbuf->image->control_pages)) {
667                 WARN_ON(1);
668                 return -EINVAL;
669         }
670
671         /* Ensure minimum alignment needed for segments. */
672         kbuf->memsz = ALIGN(kbuf->memsz, PAGE_SIZE);
673         kbuf->buf_align = max(kbuf->buf_align, PAGE_SIZE);
674
675         /* Walk the RAM ranges and allocate a suitable range for the buffer */
676         ret = arch_kexec_locate_mem_hole(kbuf);
677         if (ret)
678                 return ret;
679
680         /* Found a suitable memory range */
681         ksegment = &kbuf->image->segment[kbuf->image->nr_segments];
682         ksegment->kbuf = kbuf->buffer;
683         ksegment->bufsz = kbuf->bufsz;
684         ksegment->mem = kbuf->mem;
685         ksegment->memsz = kbuf->memsz;
686         kbuf->image->nr_segments++;
687         return 0;
688 }
689
690 /* Calculate and store the digest of segments */
691 static int kexec_calculate_store_digests(struct kimage *image)
692 {
693         struct crypto_shash *tfm;
694         struct shash_desc *desc;
695         int ret = 0, i, j, zero_buf_sz, sha_region_sz;
696         size_t desc_size, nullsz;
697         char *digest;
698         void *zero_buf;
699         struct kexec_sha_region *sha_regions;
700         struct purgatory_info *pi = &image->purgatory_info;
701
702         if (!IS_ENABLED(CONFIG_ARCH_HAS_KEXEC_PURGATORY))
703                 return 0;
704
705         zero_buf = __va(page_to_pfn(ZERO_PAGE(0)) << PAGE_SHIFT);
706         zero_buf_sz = PAGE_SIZE;
707
708         tfm = crypto_alloc_shash("sha256", 0, 0);
709         if (IS_ERR(tfm)) {
710                 ret = PTR_ERR(tfm);
711                 goto out;
712         }
713
714         desc_size = crypto_shash_descsize(tfm) + sizeof(*desc);
715         desc = kzalloc(desc_size, GFP_KERNEL);
716         if (!desc) {
717                 ret = -ENOMEM;
718                 goto out_free_tfm;
719         }
720
721         sha_region_sz = KEXEC_SEGMENT_MAX * sizeof(struct kexec_sha_region);
722         sha_regions = vzalloc(sha_region_sz);
723         if (!sha_regions) {
724                 ret = -ENOMEM;
725                 goto out_free_desc;
726         }
727
728         desc->tfm   = tfm;
729
730         ret = crypto_shash_init(desc);
731         if (ret < 0)
732                 goto out_free_sha_regions;
733
734         digest = kzalloc(SHA256_DIGEST_SIZE, GFP_KERNEL);
735         if (!digest) {
736                 ret = -ENOMEM;
737                 goto out_free_sha_regions;
738         }
739
740         for (j = i = 0; i < image->nr_segments; i++) {
741                 struct kexec_segment *ksegment;
742
743                 ksegment = &image->segment[i];
744                 /*
745                  * Skip purgatory as it will be modified once we put digest
746                  * info in purgatory.
747                  */
748                 if (ksegment->kbuf == pi->purgatory_buf)
749                         continue;
750
751                 ret = crypto_shash_update(desc, ksegment->kbuf,
752                                           ksegment->bufsz);
753                 if (ret)
754                         break;
755
756                 /*
757                  * Assume rest of the buffer is filled with zero and
758                  * update digest accordingly.
759                  */
760                 nullsz = ksegment->memsz - ksegment->bufsz;
761                 while (nullsz) {
762                         unsigned long bytes = nullsz;
763
764                         if (bytes > zero_buf_sz)
765                                 bytes = zero_buf_sz;
766                         ret = crypto_shash_update(desc, zero_buf, bytes);
767                         if (ret)
768                                 break;
769                         nullsz -= bytes;
770                 }
771
772                 if (ret)
773                         break;
774
775                 sha_regions[j].start = ksegment->mem;
776                 sha_regions[j].len = ksegment->memsz;
777                 j++;
778         }
779
780         if (!ret) {
781                 ret = crypto_shash_final(desc, digest);
782                 if (ret)
783                         goto out_free_digest;
784                 ret = kexec_purgatory_get_set_symbol(image, "purgatory_sha_regions",
785                                                      sha_regions, sha_region_sz, 0);
786                 if (ret)
787                         goto out_free_digest;
788
789                 ret = kexec_purgatory_get_set_symbol(image, "purgatory_sha256_digest",
790                                                      digest, SHA256_DIGEST_SIZE, 0);
791                 if (ret)
792                         goto out_free_digest;
793         }
794
795 out_free_digest:
796         kfree(digest);
797 out_free_sha_regions:
798         vfree(sha_regions);
799 out_free_desc:
800         kfree(desc);
801 out_free_tfm:
802         kfree(tfm);
803 out:
804         return ret;
805 }
806
807 #ifdef CONFIG_ARCH_HAS_KEXEC_PURGATORY
808 /*
809  * kexec_purgatory_setup_kbuf - prepare buffer to load purgatory.
810  * @pi:         Purgatory to be loaded.
811  * @kbuf:       Buffer to setup.
812  *
813  * Allocates the memory needed for the buffer. Caller is responsible to free
814  * the memory after use.
815  *
816  * Return: 0 on success, negative errno on error.
817  */
818 static int kexec_purgatory_setup_kbuf(struct purgatory_info *pi,
819                                       struct kexec_buf *kbuf)
820 {
821         const Elf_Shdr *sechdrs;
822         unsigned long bss_align;
823         unsigned long bss_sz;
824         unsigned long align;
825         int i, ret;
826
827         sechdrs = (void *)pi->ehdr + pi->ehdr->e_shoff;
828         kbuf->buf_align = bss_align = 1;
829         kbuf->bufsz = bss_sz = 0;
830
831         for (i = 0; i < pi->ehdr->e_shnum; i++) {
832                 if (!(sechdrs[i].sh_flags & SHF_ALLOC))
833                         continue;
834
835                 align = sechdrs[i].sh_addralign;
836                 if (sechdrs[i].sh_type != SHT_NOBITS) {
837                         if (kbuf->buf_align < align)
838                                 kbuf->buf_align = align;
839                         kbuf->bufsz = ALIGN(kbuf->bufsz, align);
840                         kbuf->bufsz += sechdrs[i].sh_size;
841                 } else {
842                         if (bss_align < align)
843                                 bss_align = align;
844                         bss_sz = ALIGN(bss_sz, align);
845                         bss_sz += sechdrs[i].sh_size;
846                 }
847         }
848         kbuf->bufsz = ALIGN(kbuf->bufsz, bss_align);
849         kbuf->memsz = kbuf->bufsz + bss_sz;
850         if (kbuf->buf_align < bss_align)
851                 kbuf->buf_align = bss_align;
852
853         kbuf->buffer = vzalloc(kbuf->bufsz);
854         if (!kbuf->buffer)
855                 return -ENOMEM;
856         pi->purgatory_buf = kbuf->buffer;
857
858         ret = kexec_add_buffer(kbuf);
859         if (ret)
860                 goto out;
861
862         return 0;
863 out:
864         vfree(pi->purgatory_buf);
865         pi->purgatory_buf = NULL;
866         return ret;
867 }
868
869 /*
870  * kexec_purgatory_setup_sechdrs - prepares the pi->sechdrs buffer.
871  * @pi:         Purgatory to be loaded.
872  * @kbuf:       Buffer prepared to store purgatory.
873  *
874  * Allocates the memory needed for the buffer. Caller is responsible to free
875  * the memory after use.
876  *
877  * Return: 0 on success, negative errno on error.
878  */
879 static int kexec_purgatory_setup_sechdrs(struct purgatory_info *pi,
880                                          struct kexec_buf *kbuf)
881 {
882         unsigned long bss_addr;
883         unsigned long offset;
884         Elf_Shdr *sechdrs;
885         int i;
886
887         /*
888          * The section headers in kexec_purgatory are read-only. In order to
889          * have them modifiable make a temporary copy.
890          */
891         sechdrs = vzalloc(array_size(sizeof(Elf_Shdr), pi->ehdr->e_shnum));
892         if (!sechdrs)
893                 return -ENOMEM;
894         memcpy(sechdrs, (void *)pi->ehdr + pi->ehdr->e_shoff,
895                pi->ehdr->e_shnum * sizeof(Elf_Shdr));
896         pi->sechdrs = sechdrs;
897
898         offset = 0;
899         bss_addr = kbuf->mem + kbuf->bufsz;
900         kbuf->image->start = pi->ehdr->e_entry;
901
902         for (i = 0; i < pi->ehdr->e_shnum; i++) {
903                 unsigned long align;
904                 void *src, *dst;
905
906                 if (!(sechdrs[i].sh_flags & SHF_ALLOC))
907                         continue;
908
909                 align = sechdrs[i].sh_addralign;
910                 if (sechdrs[i].sh_type == SHT_NOBITS) {
911                         bss_addr = ALIGN(bss_addr, align);
912                         sechdrs[i].sh_addr = bss_addr;
913                         bss_addr += sechdrs[i].sh_size;
914                         continue;
915                 }
916
917                 offset = ALIGN(offset, align);
918                 if (sechdrs[i].sh_flags & SHF_EXECINSTR &&
919                     pi->ehdr->e_entry >= sechdrs[i].sh_addr &&
920                     pi->ehdr->e_entry < (sechdrs[i].sh_addr
921                                          + sechdrs[i].sh_size)) {
922                         kbuf->image->start -= sechdrs[i].sh_addr;
923                         kbuf->image->start += kbuf->mem + offset;
924                 }
925
926                 src = (void *)pi->ehdr + sechdrs[i].sh_offset;
927                 dst = pi->purgatory_buf + offset;
928                 memcpy(dst, src, sechdrs[i].sh_size);
929
930                 sechdrs[i].sh_addr = kbuf->mem + offset;
931                 sechdrs[i].sh_offset = offset;
932                 offset += sechdrs[i].sh_size;
933         }
934
935         return 0;
936 }
937
938 static int kexec_apply_relocations(struct kimage *image)
939 {
940         int i, ret;
941         struct purgatory_info *pi = &image->purgatory_info;
942         const Elf_Shdr *sechdrs;
943
944         sechdrs = (void *)pi->ehdr + pi->ehdr->e_shoff;
945
946         for (i = 0; i < pi->ehdr->e_shnum; i++) {
947                 const Elf_Shdr *relsec;
948                 const Elf_Shdr *symtab;
949                 Elf_Shdr *section;
950
951                 relsec = sechdrs + i;
952
953                 if (relsec->sh_type != SHT_RELA &&
954                     relsec->sh_type != SHT_REL)
955                         continue;
956
957                 /*
958                  * For section of type SHT_RELA/SHT_REL,
959                  * ->sh_link contains section header index of associated
960                  * symbol table. And ->sh_info contains section header
961                  * index of section to which relocations apply.
962                  */
963                 if (relsec->sh_info >= pi->ehdr->e_shnum ||
964                     relsec->sh_link >= pi->ehdr->e_shnum)
965                         return -ENOEXEC;
966
967                 section = pi->sechdrs + relsec->sh_info;
968                 symtab = sechdrs + relsec->sh_link;
969
970                 if (!(section->sh_flags & SHF_ALLOC))
971                         continue;
972
973                 /*
974                  * symtab->sh_link contain section header index of associated
975                  * string table.
976                  */
977                 if (symtab->sh_link >= pi->ehdr->e_shnum)
978                         /* Invalid section number? */
979                         continue;
980
981                 /*
982                  * Respective architecture needs to provide support for applying
983                  * relocations of type SHT_RELA/SHT_REL.
984                  */
985                 if (relsec->sh_type == SHT_RELA)
986                         ret = arch_kexec_apply_relocations_add(pi, section,
987                                                                relsec, symtab);
988                 else if (relsec->sh_type == SHT_REL)
989                         ret = arch_kexec_apply_relocations(pi, section,
990                                                            relsec, symtab);
991                 if (ret)
992                         return ret;
993         }
994
995         return 0;
996 }
997
998 /*
999  * kexec_load_purgatory - Load and relocate the purgatory object.
1000  * @image:      Image to add the purgatory to.
1001  * @kbuf:       Memory parameters to use.
1002  *
1003  * Allocates the memory needed for image->purgatory_info.sechdrs and
1004  * image->purgatory_info.purgatory_buf/kbuf->buffer. Caller is responsible
1005  * to free the memory after use.
1006  *
1007  * Return: 0 on success, negative errno on error.
1008  */
1009 int kexec_load_purgatory(struct kimage *image, struct kexec_buf *kbuf)
1010 {
1011         struct purgatory_info *pi = &image->purgatory_info;
1012         int ret;
1013
1014         if (kexec_purgatory_size <= 0)
1015                 return -EINVAL;
1016
1017         pi->ehdr = (const Elf_Ehdr *)kexec_purgatory;
1018
1019         ret = kexec_purgatory_setup_kbuf(pi, kbuf);
1020         if (ret)
1021                 return ret;
1022
1023         ret = kexec_purgatory_setup_sechdrs(pi, kbuf);
1024         if (ret)
1025                 goto out_free_kbuf;
1026
1027         ret = kexec_apply_relocations(image);
1028         if (ret)
1029                 goto out;
1030
1031         return 0;
1032 out:
1033         vfree(pi->sechdrs);
1034         pi->sechdrs = NULL;
1035 out_free_kbuf:
1036         vfree(pi->purgatory_buf);
1037         pi->purgatory_buf = NULL;
1038         return ret;
1039 }
1040
1041 /*
1042  * kexec_purgatory_find_symbol - find a symbol in the purgatory
1043  * @pi:         Purgatory to search in.
1044  * @name:       Name of the symbol.
1045  *
1046  * Return: pointer to symbol in read-only symtab on success, NULL on error.
1047  */
1048 static const Elf_Sym *kexec_purgatory_find_symbol(struct purgatory_info *pi,
1049                                                   const char *name)
1050 {
1051         const Elf_Shdr *sechdrs;
1052         const Elf_Ehdr *ehdr;
1053         const Elf_Sym *syms;
1054         const char *strtab;
1055         int i, k;
1056
1057         if (!pi->ehdr)
1058                 return NULL;
1059
1060         ehdr = pi->ehdr;
1061         sechdrs = (void *)ehdr + ehdr->e_shoff;
1062
1063         for (i = 0; i < ehdr->e_shnum; i++) {
1064                 if (sechdrs[i].sh_type != SHT_SYMTAB)
1065                         continue;
1066
1067                 if (sechdrs[i].sh_link >= ehdr->e_shnum)
1068                         /* Invalid strtab section number */
1069                         continue;
1070                 strtab = (void *)ehdr + sechdrs[sechdrs[i].sh_link].sh_offset;
1071                 syms = (void *)ehdr + sechdrs[i].sh_offset;
1072
1073                 /* Go through symbols for a match */
1074                 for (k = 0; k < sechdrs[i].sh_size/sizeof(Elf_Sym); k++) {
1075                         if (ELF_ST_BIND(syms[k].st_info) != STB_GLOBAL)
1076                                 continue;
1077
1078                         if (strcmp(strtab + syms[k].st_name, name) != 0)
1079                                 continue;
1080
1081                         if (syms[k].st_shndx == SHN_UNDEF ||
1082                             syms[k].st_shndx >= ehdr->e_shnum) {
1083                                 pr_debug("Symbol: %s has bad section index %d.\n",
1084                                                 name, syms[k].st_shndx);
1085                                 return NULL;
1086                         }
1087
1088                         /* Found the symbol we are looking for */
1089                         return &syms[k];
1090                 }
1091         }
1092
1093         return NULL;
1094 }
1095
1096 void *kexec_purgatory_get_symbol_addr(struct kimage *image, const char *name)
1097 {
1098         struct purgatory_info *pi = &image->purgatory_info;
1099         const Elf_Sym *sym;
1100         Elf_Shdr *sechdr;
1101
1102         sym = kexec_purgatory_find_symbol(pi, name);
1103         if (!sym)
1104                 return ERR_PTR(-EINVAL);
1105
1106         sechdr = &pi->sechdrs[sym->st_shndx];
1107
1108         /*
1109          * Returns the address where symbol will finally be loaded after
1110          * kexec_load_segment()
1111          */
1112         return (void *)(sechdr->sh_addr + sym->st_value);
1113 }
1114
1115 /*
1116  * Get or set value of a symbol. If "get_value" is true, symbol value is
1117  * returned in buf otherwise symbol value is set based on value in buf.
1118  */
1119 int kexec_purgatory_get_set_symbol(struct kimage *image, const char *name,
1120                                    void *buf, unsigned int size, bool get_value)
1121 {
1122         struct purgatory_info *pi = &image->purgatory_info;
1123         const Elf_Sym *sym;
1124         Elf_Shdr *sec;
1125         char *sym_buf;
1126
1127         sym = kexec_purgatory_find_symbol(pi, name);
1128         if (!sym)
1129                 return -EINVAL;
1130
1131         if (sym->st_size != size) {
1132                 pr_err("symbol %s size mismatch: expected %lu actual %u\n",
1133                        name, (unsigned long)sym->st_size, size);
1134                 return -EINVAL;
1135         }
1136
1137         sec = pi->sechdrs + sym->st_shndx;
1138
1139         if (sec->sh_type == SHT_NOBITS) {
1140                 pr_err("symbol %s is in a bss section. Cannot %s\n", name,
1141                        get_value ? "get" : "set");
1142                 return -EINVAL;
1143         }
1144
1145         sym_buf = (char *)pi->purgatory_buf + sec->sh_offset + sym->st_value;
1146
1147         if (get_value)
1148                 memcpy((void *)buf, sym_buf, size);
1149         else
1150                 memcpy((void *)sym_buf, buf, size);
1151
1152         return 0;
1153 }
1154 #endif /* CONFIG_ARCH_HAS_KEXEC_PURGATORY */
1155
1156 int crash_exclude_mem_range(struct crash_mem *mem,
1157                             unsigned long long mstart, unsigned long long mend)
1158 {
1159         int i, j;
1160         unsigned long long start, end, p_start, p_end;
1161         struct crash_mem_range temp_range = {0, 0};
1162
1163         for (i = 0; i < mem->nr_ranges; i++) {
1164                 start = mem->ranges[i].start;
1165                 end = mem->ranges[i].end;
1166                 p_start = mstart;
1167                 p_end = mend;
1168
1169                 if (mstart > end || mend < start)
1170                         continue;
1171
1172                 /* Truncate any area outside of range */
1173                 if (mstart < start)
1174                         p_start = start;
1175                 if (mend > end)
1176                         p_end = end;
1177
1178                 /* Found completely overlapping range */
1179                 if (p_start == start && p_end == end) {
1180                         mem->ranges[i].start = 0;
1181                         mem->ranges[i].end = 0;
1182                         if (i < mem->nr_ranges - 1) {
1183                                 /* Shift rest of the ranges to left */
1184                                 for (j = i; j < mem->nr_ranges - 1; j++) {
1185                                         mem->ranges[j].start =
1186                                                 mem->ranges[j+1].start;
1187                                         mem->ranges[j].end =
1188                                                         mem->ranges[j+1].end;
1189                                 }
1190
1191                                 /*
1192                                  * Continue to check if there are another overlapping ranges
1193                                  * from the current position because of shifting the above
1194                                  * mem ranges.
1195                                  */
1196                                 i--;
1197                                 mem->nr_ranges--;
1198                                 continue;
1199                         }
1200                         mem->nr_ranges--;
1201                         return 0;
1202                 }
1203
1204                 if (p_start > start && p_end < end) {
1205                         /* Split original range */
1206                         mem->ranges[i].end = p_start - 1;
1207                         temp_range.start = p_end + 1;
1208                         temp_range.end = end;
1209                 } else if (p_start != start)
1210                         mem->ranges[i].end = p_start - 1;
1211                 else
1212                         mem->ranges[i].start = p_end + 1;
1213                 break;
1214         }
1215
1216         /* If a split happened, add the split to array */
1217         if (!temp_range.end)
1218                 return 0;
1219
1220         /* Split happened */
1221         if (i == mem->max_nr_ranges - 1)
1222                 return -ENOMEM;
1223
1224         /* Location where new range should go */
1225         j = i + 1;
1226         if (j < mem->nr_ranges) {
1227                 /* Move over all ranges one slot towards the end */
1228                 for (i = mem->nr_ranges - 1; i >= j; i--)
1229                         mem->ranges[i + 1] = mem->ranges[i];
1230         }
1231
1232         mem->ranges[j].start = temp_range.start;
1233         mem->ranges[j].end = temp_range.end;
1234         mem->nr_ranges++;
1235         return 0;
1236 }
1237
1238 int crash_prepare_elf64_headers(struct crash_mem *mem, int need_kernel_map,
1239                           void **addr, unsigned long *sz)
1240 {
1241         Elf64_Ehdr *ehdr;
1242         Elf64_Phdr *phdr;
1243         unsigned long nr_cpus = num_possible_cpus(), nr_phdr, elf_sz;
1244         unsigned char *buf;
1245         unsigned int cpu, i;
1246         unsigned long long notes_addr;
1247         unsigned long mstart, mend;
1248
1249         /* extra phdr for vmcoreinfo ELF note */
1250         nr_phdr = nr_cpus + 1;
1251         nr_phdr += mem->nr_ranges;
1252
1253         /*
1254          * kexec-tools creates an extra PT_LOAD phdr for kernel text mapping
1255          * area (for example, ffffffff80000000 - ffffffffa0000000 on x86_64).
1256          * I think this is required by tools like gdb. So same physical
1257          * memory will be mapped in two ELF headers. One will contain kernel
1258          * text virtual addresses and other will have __va(physical) addresses.
1259          */
1260
1261         nr_phdr++;
1262         elf_sz = sizeof(Elf64_Ehdr) + nr_phdr * sizeof(Elf64_Phdr);
1263         elf_sz = ALIGN(elf_sz, ELF_CORE_HEADER_ALIGN);
1264
1265         buf = vzalloc(elf_sz);
1266         if (!buf)
1267                 return -ENOMEM;
1268
1269         ehdr = (Elf64_Ehdr *)buf;
1270         phdr = (Elf64_Phdr *)(ehdr + 1);
1271         memcpy(ehdr->e_ident, ELFMAG, SELFMAG);
1272         ehdr->e_ident[EI_CLASS] = ELFCLASS64;
1273         ehdr->e_ident[EI_DATA] = ELFDATA2LSB;
1274         ehdr->e_ident[EI_VERSION] = EV_CURRENT;
1275         ehdr->e_ident[EI_OSABI] = ELF_OSABI;
1276         memset(ehdr->e_ident + EI_PAD, 0, EI_NIDENT - EI_PAD);
1277         ehdr->e_type = ET_CORE;
1278         ehdr->e_machine = ELF_ARCH;
1279         ehdr->e_version = EV_CURRENT;
1280         ehdr->e_phoff = sizeof(Elf64_Ehdr);
1281         ehdr->e_ehsize = sizeof(Elf64_Ehdr);
1282         ehdr->e_phentsize = sizeof(Elf64_Phdr);
1283
1284         /* Prepare one phdr of type PT_NOTE for each present CPU */
1285         for_each_present_cpu(cpu) {
1286                 phdr->p_type = PT_NOTE;
1287                 notes_addr = per_cpu_ptr_to_phys(per_cpu_ptr(crash_notes, cpu));
1288                 phdr->p_offset = phdr->p_paddr = notes_addr;
1289                 phdr->p_filesz = phdr->p_memsz = sizeof(note_buf_t);
1290                 (ehdr->e_phnum)++;
1291                 phdr++;
1292         }
1293
1294         /* Prepare one PT_NOTE header for vmcoreinfo */
1295         phdr->p_type = PT_NOTE;
1296         phdr->p_offset = phdr->p_paddr = paddr_vmcoreinfo_note();
1297         phdr->p_filesz = phdr->p_memsz = VMCOREINFO_NOTE_SIZE;
1298         (ehdr->e_phnum)++;
1299         phdr++;
1300
1301         /* Prepare PT_LOAD type program header for kernel text region */
1302         if (need_kernel_map) {
1303                 phdr->p_type = PT_LOAD;
1304                 phdr->p_flags = PF_R|PF_W|PF_X;
1305                 phdr->p_vaddr = (unsigned long) _text;
1306                 phdr->p_filesz = phdr->p_memsz = _end - _text;
1307                 phdr->p_offset = phdr->p_paddr = __pa_symbol(_text);
1308                 ehdr->e_phnum++;
1309                 phdr++;
1310         }
1311
1312         /* Go through all the ranges in mem->ranges[] and prepare phdr */
1313         for (i = 0; i < mem->nr_ranges; i++) {
1314                 mstart = mem->ranges[i].start;
1315                 mend = mem->ranges[i].end;
1316
1317                 phdr->p_type = PT_LOAD;
1318                 phdr->p_flags = PF_R|PF_W|PF_X;
1319                 phdr->p_offset  = mstart;
1320
1321                 phdr->p_paddr = mstart;
1322                 phdr->p_vaddr = (unsigned long) __va(mstart);
1323                 phdr->p_filesz = phdr->p_memsz = mend - mstart + 1;
1324                 phdr->p_align = 0;
1325                 ehdr->e_phnum++;
1326                 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",
1327                         phdr, phdr->p_vaddr, phdr->p_paddr, phdr->p_filesz,
1328                         ehdr->e_phnum, phdr->p_offset);
1329                 phdr++;
1330         }
1331
1332         *addr = buf;
1333         *sz = elf_sz;
1334         return 0;
1335 }