Merge tag 'for-linus-5.9-rc1b-tag' of git://git.kernel.org/pub/scm/linux/kernel/git...
[platform/kernel/linux-rpi.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/sha.h>
24 #include <linux/elf.h>
25 #include <linux/elfcore.h>
26 #include <linux/kernel.h>
27 #include <linux/syscalls.h>
28 #include <linux/vmalloc.h>
29 #include "kexec_internal.h"
30
31 static int kexec_calculate_store_digests(struct kimage *image);
32
33 /*
34  * Currently this is the only default function that is exported as some
35  * architectures need it to do additional handlings.
36  * In the future, other default functions may be exported too if required.
37  */
38 int kexec_image_probe_default(struct kimage *image, void *buf,
39                               unsigned long buf_len)
40 {
41         const struct kexec_file_ops * const *fops;
42         int ret = -ENOEXEC;
43
44         for (fops = &kexec_file_loaders[0]; *fops && (*fops)->probe; ++fops) {
45                 ret = (*fops)->probe(buf, buf_len);
46                 if (!ret) {
47                         image->fops = *fops;
48                         return ret;
49                 }
50         }
51
52         return ret;
53 }
54
55 /* Architectures can provide this probe function */
56 int __weak arch_kexec_kernel_image_probe(struct kimage *image, void *buf,
57                                          unsigned long buf_len)
58 {
59         return kexec_image_probe_default(image, buf, buf_len);
60 }
61
62 static void *kexec_image_load_default(struct kimage *image)
63 {
64         if (!image->fops || !image->fops->load)
65                 return ERR_PTR(-ENOEXEC);
66
67         return image->fops->load(image, image->kernel_buf,
68                                  image->kernel_buf_len, image->initrd_buf,
69                                  image->initrd_buf_len, image->cmdline_buf,
70                                  image->cmdline_buf_len);
71 }
72
73 void * __weak arch_kexec_kernel_image_load(struct kimage *image)
74 {
75         return kexec_image_load_default(image);
76 }
77
78 int kexec_image_post_load_cleanup_default(struct kimage *image)
79 {
80         if (!image->fops || !image->fops->cleanup)
81                 return 0;
82
83         return image->fops->cleanup(image->image_loader_data);
84 }
85
86 int __weak arch_kimage_file_post_load_cleanup(struct kimage *image)
87 {
88         return kexec_image_post_load_cleanup_default(image);
89 }
90
91 #ifdef CONFIG_KEXEC_SIG
92 static int kexec_image_verify_sig_default(struct kimage *image, void *buf,
93                                           unsigned long buf_len)
94 {
95         if (!image->fops || !image->fops->verify_sig) {
96                 pr_debug("kernel loader does not support signature verification.\n");
97                 return -EKEYREJECTED;
98         }
99
100         return image->fops->verify_sig(buf, buf_len);
101 }
102
103 int __weak arch_kexec_kernel_verify_sig(struct kimage *image, void *buf,
104                                         unsigned long buf_len)
105 {
106         return kexec_image_verify_sig_default(image, buf, buf_len);
107 }
108 #endif
109
110 /*
111  * arch_kexec_apply_relocations_add - apply relocations of type RELA
112  * @pi:         Purgatory to be relocated.
113  * @section:    Section relocations applying to.
114  * @relsec:     Section containing RELAs.
115  * @symtab:     Corresponding symtab.
116  *
117  * Return: 0 on success, negative errno on error.
118  */
119 int __weak
120 arch_kexec_apply_relocations_add(struct purgatory_info *pi, Elf_Shdr *section,
121                                  const Elf_Shdr *relsec, const Elf_Shdr *symtab)
122 {
123         pr_err("RELA relocation unsupported.\n");
124         return -ENOEXEC;
125 }
126
127 /*
128  * arch_kexec_apply_relocations - apply relocations of type REL
129  * @pi:         Purgatory to be relocated.
130  * @section:    Section relocations applying to.
131  * @relsec:     Section containing RELs.
132  * @symtab:     Corresponding symtab.
133  *
134  * Return: 0 on success, negative errno on error.
135  */
136 int __weak
137 arch_kexec_apply_relocations(struct purgatory_info *pi, Elf_Shdr *section,
138                              const Elf_Shdr *relsec, const Elf_Shdr *symtab)
139 {
140         pr_err("REL relocation unsupported.\n");
141         return -ENOEXEC;
142 }
143
144 /*
145  * Free up memory used by kernel, initrd, and command line. This is temporary
146  * memory allocation which is not needed any more after these buffers have
147  * been loaded into separate segments and have been copied elsewhere.
148  */
149 void kimage_file_post_load_cleanup(struct kimage *image)
150 {
151         struct purgatory_info *pi = &image->purgatory_info;
152
153         vfree(image->kernel_buf);
154         image->kernel_buf = NULL;
155
156         vfree(image->initrd_buf);
157         image->initrd_buf = NULL;
158
159         kfree(image->cmdline_buf);
160         image->cmdline_buf = NULL;
161
162         vfree(pi->purgatory_buf);
163         pi->purgatory_buf = NULL;
164
165         vfree(pi->sechdrs);
166         pi->sechdrs = NULL;
167
168         /* See if architecture has anything to cleanup post load */
169         arch_kimage_file_post_load_cleanup(image);
170
171         /*
172          * Above call should have called into bootloader to free up
173          * any data stored in kimage->image_loader_data. It should
174          * be ok now to free it up.
175          */
176         kfree(image->image_loader_data);
177         image->image_loader_data = NULL;
178 }
179
180 #ifdef CONFIG_KEXEC_SIG
181 static int
182 kimage_validate_signature(struct kimage *image)
183 {
184         int ret;
185
186         ret = arch_kexec_kernel_verify_sig(image, image->kernel_buf,
187                                            image->kernel_buf_len);
188         if (ret) {
189
190                 if (IS_ENABLED(CONFIG_KEXEC_SIG_FORCE)) {
191                         pr_notice("Enforced kernel signature verification failed (%d).\n", ret);
192                         return ret;
193                 }
194
195                 /*
196                  * If IMA is guaranteed to appraise a signature on the kexec
197                  * image, permit it even if the kernel is otherwise locked
198                  * down.
199                  */
200                 if (!ima_appraise_signature(READING_KEXEC_IMAGE) &&
201                     security_locked_down(LOCKDOWN_KEXEC))
202                         return -EPERM;
203
204                 pr_debug("kernel signature verification failed (%d).\n", ret);
205         }
206
207         return 0;
208 }
209 #endif
210
211 /*
212  * In file mode list of segments is prepared by kernel. Copy relevant
213  * data from user space, do error checking, prepare segment list
214  */
215 static int
216 kimage_file_prepare_segments(struct kimage *image, int kernel_fd, int initrd_fd,
217                              const char __user *cmdline_ptr,
218                              unsigned long cmdline_len, unsigned flags)
219 {
220         int ret;
221         void *ldata;
222         loff_t size;
223
224         ret = kernel_read_file_from_fd(kernel_fd, &image->kernel_buf,
225                                        &size, INT_MAX, READING_KEXEC_IMAGE);
226         if (ret)
227                 return ret;
228         image->kernel_buf_len = size;
229
230         /* Call arch image probe handlers */
231         ret = arch_kexec_kernel_image_probe(image, image->kernel_buf,
232                                             image->kernel_buf_len);
233         if (ret)
234                 goto out;
235
236 #ifdef CONFIG_KEXEC_SIG
237         ret = kimage_validate_signature(image);
238
239         if (ret)
240                 goto out;
241 #endif
242         /* It is possible that there no initramfs is being loaded */
243         if (!(flags & KEXEC_FILE_NO_INITRAMFS)) {
244                 ret = kernel_read_file_from_fd(initrd_fd, &image->initrd_buf,
245                                                &size, INT_MAX,
246                                                READING_KEXEC_INITRAMFS);
247                 if (ret)
248                         goto out;
249                 image->initrd_buf_len = size;
250         }
251
252         if (cmdline_len) {
253                 image->cmdline_buf = memdup_user(cmdline_ptr, cmdline_len);
254                 if (IS_ERR(image->cmdline_buf)) {
255                         ret = PTR_ERR(image->cmdline_buf);
256                         image->cmdline_buf = NULL;
257                         goto out;
258                 }
259
260                 image->cmdline_buf_len = cmdline_len;
261
262                 /* command line should be a string with last byte null */
263                 if (image->cmdline_buf[cmdline_len - 1] != '\0') {
264                         ret = -EINVAL;
265                         goto out;
266                 }
267
268                 ima_kexec_cmdline(kernel_fd, image->cmdline_buf,
269                                   image->cmdline_buf_len - 1);
270         }
271
272         /* IMA needs to pass the measurement list to the next kernel. */
273         ima_add_kexec_buffer(image);
274
275         /* Call arch image load handlers */
276         ldata = arch_kexec_kernel_image_load(image);
277
278         if (IS_ERR(ldata)) {
279                 ret = PTR_ERR(ldata);
280                 goto out;
281         }
282
283         image->image_loader_data = ldata;
284 out:
285         /* In case of error, free up all allocated memory in this function */
286         if (ret)
287                 kimage_file_post_load_cleanup(image);
288         return ret;
289 }
290
291 static int
292 kimage_file_alloc_init(struct kimage **rimage, int kernel_fd,
293                        int initrd_fd, const char __user *cmdline_ptr,
294                        unsigned long cmdline_len, unsigned long flags)
295 {
296         int ret;
297         struct kimage *image;
298         bool kexec_on_panic = flags & KEXEC_FILE_ON_CRASH;
299
300         image = do_kimage_alloc_init();
301         if (!image)
302                 return -ENOMEM;
303
304         image->file_mode = 1;
305
306         if (kexec_on_panic) {
307                 /* Enable special crash kernel control page alloc policy. */
308                 image->control_page = crashk_res.start;
309                 image->type = KEXEC_TYPE_CRASH;
310         }
311
312         ret = kimage_file_prepare_segments(image, kernel_fd, initrd_fd,
313                                            cmdline_ptr, cmdline_len, flags);
314         if (ret)
315                 goto out_free_image;
316
317         ret = sanity_check_segment_list(image);
318         if (ret)
319                 goto out_free_post_load_bufs;
320
321         ret = -ENOMEM;
322         image->control_code_page = kimage_alloc_control_pages(image,
323                                            get_order(KEXEC_CONTROL_PAGE_SIZE));
324         if (!image->control_code_page) {
325                 pr_err("Could not allocate control_code_buffer\n");
326                 goto out_free_post_load_bufs;
327         }
328
329         if (!kexec_on_panic) {
330                 image->swap_page = kimage_alloc_control_pages(image, 0);
331                 if (!image->swap_page) {
332                         pr_err("Could not allocate swap buffer\n");
333                         goto out_free_control_pages;
334                 }
335         }
336
337         *rimage = image;
338         return 0;
339 out_free_control_pages:
340         kimage_free_page_list(&image->control_pages);
341 out_free_post_load_bufs:
342         kimage_file_post_load_cleanup(image);
343 out_free_image:
344         kfree(image);
345         return ret;
346 }
347
348 SYSCALL_DEFINE5(kexec_file_load, int, kernel_fd, int, initrd_fd,
349                 unsigned long, cmdline_len, const char __user *, cmdline_ptr,
350                 unsigned long, flags)
351 {
352         int ret = 0, i;
353         struct kimage **dest_image, *image;
354
355         /* We only trust the superuser with rebooting the system. */
356         if (!capable(CAP_SYS_BOOT) || kexec_load_disabled)
357                 return -EPERM;
358
359         /* Make sure we have a legal set of flags */
360         if (flags != (flags & KEXEC_FILE_FLAGS))
361                 return -EINVAL;
362
363         image = NULL;
364
365         if (!mutex_trylock(&kexec_mutex))
366                 return -EBUSY;
367
368         dest_image = &kexec_image;
369         if (flags & KEXEC_FILE_ON_CRASH) {
370                 dest_image = &kexec_crash_image;
371                 if (kexec_crash_image)
372                         arch_kexec_unprotect_crashkres();
373         }
374
375         if (flags & KEXEC_FILE_UNLOAD)
376                 goto exchange;
377
378         /*
379          * In case of crash, new kernel gets loaded in reserved region. It is
380          * same memory where old crash kernel might be loaded. Free any
381          * current crash dump kernel before we corrupt it.
382          */
383         if (flags & KEXEC_FILE_ON_CRASH)
384                 kimage_free(xchg(&kexec_crash_image, NULL));
385
386         ret = kimage_file_alloc_init(&image, kernel_fd, initrd_fd, cmdline_ptr,
387                                      cmdline_len, flags);
388         if (ret)
389                 goto out;
390
391         ret = machine_kexec_prepare(image);
392         if (ret)
393                 goto out;
394
395         /*
396          * Some architecture(like S390) may touch the crash memory before
397          * machine_kexec_prepare(), we must copy vmcoreinfo data after it.
398          */
399         ret = kimage_crash_copy_vmcoreinfo(image);
400         if (ret)
401                 goto out;
402
403         ret = kexec_calculate_store_digests(image);
404         if (ret)
405                 goto out;
406
407         for (i = 0; i < image->nr_segments; i++) {
408                 struct kexec_segment *ksegment;
409
410                 ksegment = &image->segment[i];
411                 pr_debug("Loading segment %d: buf=0x%p bufsz=0x%zx mem=0x%lx memsz=0x%zx\n",
412                          i, ksegment->buf, ksegment->bufsz, ksegment->mem,
413                          ksegment->memsz);
414
415                 ret = kimage_load_segment(image, &image->segment[i]);
416                 if (ret)
417                         goto out;
418         }
419
420         kimage_terminate(image);
421
422         ret = machine_kexec_post_load(image);
423         if (ret)
424                 goto out;
425
426         /*
427          * Free up any temporary buffers allocated which are not needed
428          * after image has been loaded
429          */
430         kimage_file_post_load_cleanup(image);
431 exchange:
432         image = xchg(dest_image, image);
433 out:
434         if ((flags & KEXEC_FILE_ON_CRASH) && kexec_crash_image)
435                 arch_kexec_protect_crashkres();
436
437         mutex_unlock(&kexec_mutex);
438         kimage_free(image);
439         return ret;
440 }
441
442 static int locate_mem_hole_top_down(unsigned long start, unsigned long end,
443                                     struct kexec_buf *kbuf)
444 {
445         struct kimage *image = kbuf->image;
446         unsigned long temp_start, temp_end;
447
448         temp_end = min(end, kbuf->buf_max);
449         temp_start = temp_end - kbuf->memsz;
450
451         do {
452                 /* align down start */
453                 temp_start = temp_start & (~(kbuf->buf_align - 1));
454
455                 if (temp_start < start || temp_start < kbuf->buf_min)
456                         return 0;
457
458                 temp_end = temp_start + kbuf->memsz - 1;
459
460                 /*
461                  * Make sure this does not conflict with any of existing
462                  * segments
463                  */
464                 if (kimage_is_destination_range(image, temp_start, temp_end)) {
465                         temp_start = temp_start - PAGE_SIZE;
466                         continue;
467                 }
468
469                 /* We found a suitable memory range */
470                 break;
471         } while (1);
472
473         /* If we are here, we found a suitable memory range */
474         kbuf->mem = temp_start;
475
476         /* Success, stop navigating through remaining System RAM ranges */
477         return 1;
478 }
479
480 static int locate_mem_hole_bottom_up(unsigned long start, unsigned long end,
481                                      struct kexec_buf *kbuf)
482 {
483         struct kimage *image = kbuf->image;
484         unsigned long temp_start, temp_end;
485
486         temp_start = max(start, kbuf->buf_min);
487
488         do {
489                 temp_start = ALIGN(temp_start, kbuf->buf_align);
490                 temp_end = temp_start + kbuf->memsz - 1;
491
492                 if (temp_end > end || temp_end > kbuf->buf_max)
493                         return 0;
494                 /*
495                  * Make sure this does not conflict with any of existing
496                  * segments
497                  */
498                 if (kimage_is_destination_range(image, temp_start, temp_end)) {
499                         temp_start = temp_start + PAGE_SIZE;
500                         continue;
501                 }
502
503                 /* We found a suitable memory range */
504                 break;
505         } while (1);
506
507         /* If we are here, we found a suitable memory range */
508         kbuf->mem = temp_start;
509
510         /* Success, stop navigating through remaining System RAM ranges */
511         return 1;
512 }
513
514 static int locate_mem_hole_callback(struct resource *res, void *arg)
515 {
516         struct kexec_buf *kbuf = (struct kexec_buf *)arg;
517         u64 start = res->start, end = res->end;
518         unsigned long sz = end - start + 1;
519
520         /* Returning 0 will take to next memory range */
521
522         /* Don't use memory that will be detected and handled by a driver. */
523         if (res->flags & IORESOURCE_MEM_DRIVER_MANAGED)
524                 return 0;
525
526         if (sz < kbuf->memsz)
527                 return 0;
528
529         if (end < kbuf->buf_min || start > kbuf->buf_max)
530                 return 0;
531
532         /*
533          * Allocate memory top down with-in ram range. Otherwise bottom up
534          * allocation.
535          */
536         if (kbuf->top_down)
537                 return locate_mem_hole_top_down(start, end, kbuf);
538         return locate_mem_hole_bottom_up(start, end, kbuf);
539 }
540
541 #ifdef CONFIG_ARCH_KEEP_MEMBLOCK
542 static int kexec_walk_memblock(struct kexec_buf *kbuf,
543                                int (*func)(struct resource *, void *))
544 {
545         int ret = 0;
546         u64 i;
547         phys_addr_t mstart, mend;
548         struct resource res = { };
549
550         if (kbuf->image->type == KEXEC_TYPE_CRASH)
551                 return func(&crashk_res, kbuf);
552
553         if (kbuf->top_down) {
554                 for_each_free_mem_range_reverse(i, NUMA_NO_NODE, MEMBLOCK_NONE,
555                                                 &mstart, &mend, NULL) {
556                         /*
557                          * In memblock, end points to the first byte after the
558                          * range while in kexec, end points to the last byte
559                          * in the range.
560                          */
561                         res.start = mstart;
562                         res.end = mend - 1;
563                         ret = func(&res, kbuf);
564                         if (ret)
565                                 break;
566                 }
567         } else {
568                 for_each_free_mem_range(i, NUMA_NO_NODE, MEMBLOCK_NONE,
569                                         &mstart, &mend, NULL) {
570                         /*
571                          * In memblock, end points to the first byte after the
572                          * range while in kexec, end points to the last byte
573                          * in the range.
574                          */
575                         res.start = mstart;
576                         res.end = mend - 1;
577                         ret = func(&res, kbuf);
578                         if (ret)
579                                 break;
580                 }
581         }
582
583         return ret;
584 }
585 #else
586 static int kexec_walk_memblock(struct kexec_buf *kbuf,
587                                int (*func)(struct resource *, void *))
588 {
589         return 0;
590 }
591 #endif
592
593 /**
594  * kexec_walk_resources - call func(data) on free memory regions
595  * @kbuf:       Context info for the search. Also passed to @func.
596  * @func:       Function to call for each memory region.
597  *
598  * Return: The memory walk will stop when func returns a non-zero value
599  * and that value will be returned. If all free regions are visited without
600  * func returning non-zero, then zero will be returned.
601  */
602 static int kexec_walk_resources(struct kexec_buf *kbuf,
603                                 int (*func)(struct resource *, void *))
604 {
605         if (kbuf->image->type == KEXEC_TYPE_CRASH)
606                 return walk_iomem_res_desc(crashk_res.desc,
607                                            IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY,
608                                            crashk_res.start, crashk_res.end,
609                                            kbuf, func);
610         else
611                 return walk_system_ram_res(0, ULONG_MAX, kbuf, func);
612 }
613
614 /**
615  * kexec_locate_mem_hole - find free memory for the purgatory or the next kernel
616  * @kbuf:       Parameters for the memory search.
617  *
618  * On success, kbuf->mem will have the start address of the memory region found.
619  *
620  * Return: 0 on success, negative errno on error.
621  */
622 int kexec_locate_mem_hole(struct kexec_buf *kbuf)
623 {
624         int ret;
625
626         /* Arch knows where to place */
627         if (kbuf->mem != KEXEC_BUF_MEM_UNKNOWN)
628                 return 0;
629
630         if (!IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK))
631                 ret = kexec_walk_resources(kbuf, locate_mem_hole_callback);
632         else
633                 ret = kexec_walk_memblock(kbuf, locate_mem_hole_callback);
634
635         return ret == 1 ? 0 : -EADDRNOTAVAIL;
636 }
637
638 /**
639  * arch_kexec_locate_mem_hole - Find free memory to place the segments.
640  * @kbuf:                       Parameters for the memory search.
641  *
642  * On success, kbuf->mem will have the start address of the memory region found.
643  *
644  * Return: 0 on success, negative errno on error.
645  */
646 int __weak arch_kexec_locate_mem_hole(struct kexec_buf *kbuf)
647 {
648         return kexec_locate_mem_hole(kbuf);
649 }
650
651 /**
652  * kexec_add_buffer - place a buffer in a kexec segment
653  * @kbuf:       Buffer contents and memory parameters.
654  *
655  * This function assumes that kexec_mutex is held.
656  * On successful return, @kbuf->mem will have the physical address of
657  * the buffer in memory.
658  *
659  * Return: 0 on success, negative errno on error.
660  */
661 int kexec_add_buffer(struct kexec_buf *kbuf)
662 {
663         struct kexec_segment *ksegment;
664         int ret;
665
666         /* Currently adding segment this way is allowed only in file mode */
667         if (!kbuf->image->file_mode)
668                 return -EINVAL;
669
670         if (kbuf->image->nr_segments >= KEXEC_SEGMENT_MAX)
671                 return -EINVAL;
672
673         /*
674          * Make sure we are not trying to add buffer after allocating
675          * control pages. All segments need to be placed first before
676          * any control pages are allocated. As control page allocation
677          * logic goes through list of segments to make sure there are
678          * no destination overlaps.
679          */
680         if (!list_empty(&kbuf->image->control_pages)) {
681                 WARN_ON(1);
682                 return -EINVAL;
683         }
684
685         /* Ensure minimum alignment needed for segments. */
686         kbuf->memsz = ALIGN(kbuf->memsz, PAGE_SIZE);
687         kbuf->buf_align = max(kbuf->buf_align, PAGE_SIZE);
688
689         /* Walk the RAM ranges and allocate a suitable range for the buffer */
690         ret = arch_kexec_locate_mem_hole(kbuf);
691         if (ret)
692                 return ret;
693
694         /* Found a suitable memory range */
695         ksegment = &kbuf->image->segment[kbuf->image->nr_segments];
696         ksegment->kbuf = kbuf->buffer;
697         ksegment->bufsz = kbuf->bufsz;
698         ksegment->mem = kbuf->mem;
699         ksegment->memsz = kbuf->memsz;
700         kbuf->image->nr_segments++;
701         return 0;
702 }
703
704 /* Calculate and store the digest of segments */
705 static int kexec_calculate_store_digests(struct kimage *image)
706 {
707         struct crypto_shash *tfm;
708         struct shash_desc *desc;
709         int ret = 0, i, j, zero_buf_sz, sha_region_sz;
710         size_t desc_size, nullsz;
711         char *digest;
712         void *zero_buf;
713         struct kexec_sha_region *sha_regions;
714         struct purgatory_info *pi = &image->purgatory_info;
715
716         if (!IS_ENABLED(CONFIG_ARCH_HAS_KEXEC_PURGATORY))
717                 return 0;
718
719         zero_buf = __va(page_to_pfn(ZERO_PAGE(0)) << PAGE_SHIFT);
720         zero_buf_sz = PAGE_SIZE;
721
722         tfm = crypto_alloc_shash("sha256", 0, 0);
723         if (IS_ERR(tfm)) {
724                 ret = PTR_ERR(tfm);
725                 goto out;
726         }
727
728         desc_size = crypto_shash_descsize(tfm) + sizeof(*desc);
729         desc = kzalloc(desc_size, GFP_KERNEL);
730         if (!desc) {
731                 ret = -ENOMEM;
732                 goto out_free_tfm;
733         }
734
735         sha_region_sz = KEXEC_SEGMENT_MAX * sizeof(struct kexec_sha_region);
736         sha_regions = vzalloc(sha_region_sz);
737         if (!sha_regions)
738                 goto out_free_desc;
739
740         desc->tfm   = tfm;
741
742         ret = crypto_shash_init(desc);
743         if (ret < 0)
744                 goto out_free_sha_regions;
745
746         digest = kzalloc(SHA256_DIGEST_SIZE, GFP_KERNEL);
747         if (!digest) {
748                 ret = -ENOMEM;
749                 goto out_free_sha_regions;
750         }
751
752         for (j = i = 0; i < image->nr_segments; i++) {
753                 struct kexec_segment *ksegment;
754
755                 ksegment = &image->segment[i];
756                 /*
757                  * Skip purgatory as it will be modified once we put digest
758                  * info in purgatory.
759                  */
760                 if (ksegment->kbuf == pi->purgatory_buf)
761                         continue;
762
763                 ret = crypto_shash_update(desc, ksegment->kbuf,
764                                           ksegment->bufsz);
765                 if (ret)
766                         break;
767
768                 /*
769                  * Assume rest of the buffer is filled with zero and
770                  * update digest accordingly.
771                  */
772                 nullsz = ksegment->memsz - ksegment->bufsz;
773                 while (nullsz) {
774                         unsigned long bytes = nullsz;
775
776                         if (bytes > zero_buf_sz)
777                                 bytes = zero_buf_sz;
778                         ret = crypto_shash_update(desc, zero_buf, bytes);
779                         if (ret)
780                                 break;
781                         nullsz -= bytes;
782                 }
783
784                 if (ret)
785                         break;
786
787                 sha_regions[j].start = ksegment->mem;
788                 sha_regions[j].len = ksegment->memsz;
789                 j++;
790         }
791
792         if (!ret) {
793                 ret = crypto_shash_final(desc, digest);
794                 if (ret)
795                         goto out_free_digest;
796                 ret = kexec_purgatory_get_set_symbol(image, "purgatory_sha_regions",
797                                                      sha_regions, sha_region_sz, 0);
798                 if (ret)
799                         goto out_free_digest;
800
801                 ret = kexec_purgatory_get_set_symbol(image, "purgatory_sha256_digest",
802                                                      digest, SHA256_DIGEST_SIZE, 0);
803                 if (ret)
804                         goto out_free_digest;
805         }
806
807 out_free_digest:
808         kfree(digest);
809 out_free_sha_regions:
810         vfree(sha_regions);
811 out_free_desc:
812         kfree(desc);
813 out_free_tfm:
814         kfree(tfm);
815 out:
816         return ret;
817 }
818
819 #ifdef CONFIG_ARCH_HAS_KEXEC_PURGATORY
820 /*
821  * kexec_purgatory_setup_kbuf - prepare buffer to load purgatory.
822  * @pi:         Purgatory to be loaded.
823  * @kbuf:       Buffer to setup.
824  *
825  * Allocates the memory needed for the buffer. Caller is responsible to free
826  * the memory after use.
827  *
828  * Return: 0 on success, negative errno on error.
829  */
830 static int kexec_purgatory_setup_kbuf(struct purgatory_info *pi,
831                                       struct kexec_buf *kbuf)
832 {
833         const Elf_Shdr *sechdrs;
834         unsigned long bss_align;
835         unsigned long bss_sz;
836         unsigned long align;
837         int i, ret;
838
839         sechdrs = (void *)pi->ehdr + pi->ehdr->e_shoff;
840         kbuf->buf_align = bss_align = 1;
841         kbuf->bufsz = bss_sz = 0;
842
843         for (i = 0; i < pi->ehdr->e_shnum; i++) {
844                 if (!(sechdrs[i].sh_flags & SHF_ALLOC))
845                         continue;
846
847                 align = sechdrs[i].sh_addralign;
848                 if (sechdrs[i].sh_type != SHT_NOBITS) {
849                         if (kbuf->buf_align < align)
850                                 kbuf->buf_align = align;
851                         kbuf->bufsz = ALIGN(kbuf->bufsz, align);
852                         kbuf->bufsz += sechdrs[i].sh_size;
853                 } else {
854                         if (bss_align < align)
855                                 bss_align = align;
856                         bss_sz = ALIGN(bss_sz, align);
857                         bss_sz += sechdrs[i].sh_size;
858                 }
859         }
860         kbuf->bufsz = ALIGN(kbuf->bufsz, bss_align);
861         kbuf->memsz = kbuf->bufsz + bss_sz;
862         if (kbuf->buf_align < bss_align)
863                 kbuf->buf_align = bss_align;
864
865         kbuf->buffer = vzalloc(kbuf->bufsz);
866         if (!kbuf->buffer)
867                 return -ENOMEM;
868         pi->purgatory_buf = kbuf->buffer;
869
870         ret = kexec_add_buffer(kbuf);
871         if (ret)
872                 goto out;
873
874         return 0;
875 out:
876         vfree(pi->purgatory_buf);
877         pi->purgatory_buf = NULL;
878         return ret;
879 }
880
881 /*
882  * kexec_purgatory_setup_sechdrs - prepares the pi->sechdrs buffer.
883  * @pi:         Purgatory to be loaded.
884  * @kbuf:       Buffer prepared to store purgatory.
885  *
886  * Allocates the memory needed for the buffer. Caller is responsible to free
887  * the memory after use.
888  *
889  * Return: 0 on success, negative errno on error.
890  */
891 static int kexec_purgatory_setup_sechdrs(struct purgatory_info *pi,
892                                          struct kexec_buf *kbuf)
893 {
894         unsigned long bss_addr;
895         unsigned long offset;
896         Elf_Shdr *sechdrs;
897         int i;
898
899         /*
900          * The section headers in kexec_purgatory are read-only. In order to
901          * have them modifiable make a temporary copy.
902          */
903         sechdrs = vzalloc(array_size(sizeof(Elf_Shdr), pi->ehdr->e_shnum));
904         if (!sechdrs)
905                 return -ENOMEM;
906         memcpy(sechdrs, (void *)pi->ehdr + pi->ehdr->e_shoff,
907                pi->ehdr->e_shnum * sizeof(Elf_Shdr));
908         pi->sechdrs = sechdrs;
909
910         offset = 0;
911         bss_addr = kbuf->mem + kbuf->bufsz;
912         kbuf->image->start = pi->ehdr->e_entry;
913
914         for (i = 0; i < pi->ehdr->e_shnum; i++) {
915                 unsigned long align;
916                 void *src, *dst;
917
918                 if (!(sechdrs[i].sh_flags & SHF_ALLOC))
919                         continue;
920
921                 align = sechdrs[i].sh_addralign;
922                 if (sechdrs[i].sh_type == SHT_NOBITS) {
923                         bss_addr = ALIGN(bss_addr, align);
924                         sechdrs[i].sh_addr = bss_addr;
925                         bss_addr += sechdrs[i].sh_size;
926                         continue;
927                 }
928
929                 offset = ALIGN(offset, align);
930                 if (sechdrs[i].sh_flags & SHF_EXECINSTR &&
931                     pi->ehdr->e_entry >= sechdrs[i].sh_addr &&
932                     pi->ehdr->e_entry < (sechdrs[i].sh_addr
933                                          + sechdrs[i].sh_size)) {
934                         kbuf->image->start -= sechdrs[i].sh_addr;
935                         kbuf->image->start += kbuf->mem + offset;
936                 }
937
938                 src = (void *)pi->ehdr + sechdrs[i].sh_offset;
939                 dst = pi->purgatory_buf + offset;
940                 memcpy(dst, src, sechdrs[i].sh_size);
941
942                 sechdrs[i].sh_addr = kbuf->mem + offset;
943                 sechdrs[i].sh_offset = offset;
944                 offset += sechdrs[i].sh_size;
945         }
946
947         return 0;
948 }
949
950 static int kexec_apply_relocations(struct kimage *image)
951 {
952         int i, ret;
953         struct purgatory_info *pi = &image->purgatory_info;
954         const Elf_Shdr *sechdrs;
955
956         sechdrs = (void *)pi->ehdr + pi->ehdr->e_shoff;
957
958         for (i = 0; i < pi->ehdr->e_shnum; i++) {
959                 const Elf_Shdr *relsec;
960                 const Elf_Shdr *symtab;
961                 Elf_Shdr *section;
962
963                 relsec = sechdrs + i;
964
965                 if (relsec->sh_type != SHT_RELA &&
966                     relsec->sh_type != SHT_REL)
967                         continue;
968
969                 /*
970                  * For section of type SHT_RELA/SHT_REL,
971                  * ->sh_link contains section header index of associated
972                  * symbol table. And ->sh_info contains section header
973                  * index of section to which relocations apply.
974                  */
975                 if (relsec->sh_info >= pi->ehdr->e_shnum ||
976                     relsec->sh_link >= pi->ehdr->e_shnum)
977                         return -ENOEXEC;
978
979                 section = pi->sechdrs + relsec->sh_info;
980                 symtab = sechdrs + relsec->sh_link;
981
982                 if (!(section->sh_flags & SHF_ALLOC))
983                         continue;
984
985                 /*
986                  * symtab->sh_link contain section header index of associated
987                  * string table.
988                  */
989                 if (symtab->sh_link >= pi->ehdr->e_shnum)
990                         /* Invalid section number? */
991                         continue;
992
993                 /*
994                  * Respective architecture needs to provide support for applying
995                  * relocations of type SHT_RELA/SHT_REL.
996                  */
997                 if (relsec->sh_type == SHT_RELA)
998                         ret = arch_kexec_apply_relocations_add(pi, section,
999                                                                relsec, symtab);
1000                 else if (relsec->sh_type == SHT_REL)
1001                         ret = arch_kexec_apply_relocations(pi, section,
1002                                                            relsec, symtab);
1003                 if (ret)
1004                         return ret;
1005         }
1006
1007         return 0;
1008 }
1009
1010 /*
1011  * kexec_load_purgatory - Load and relocate the purgatory object.
1012  * @image:      Image to add the purgatory to.
1013  * @kbuf:       Memory parameters to use.
1014  *
1015  * Allocates the memory needed for image->purgatory_info.sechdrs and
1016  * image->purgatory_info.purgatory_buf/kbuf->buffer. Caller is responsible
1017  * to free the memory after use.
1018  *
1019  * Return: 0 on success, negative errno on error.
1020  */
1021 int kexec_load_purgatory(struct kimage *image, struct kexec_buf *kbuf)
1022 {
1023         struct purgatory_info *pi = &image->purgatory_info;
1024         int ret;
1025
1026         if (kexec_purgatory_size <= 0)
1027                 return -EINVAL;
1028
1029         pi->ehdr = (const Elf_Ehdr *)kexec_purgatory;
1030
1031         ret = kexec_purgatory_setup_kbuf(pi, kbuf);
1032         if (ret)
1033                 return ret;
1034
1035         ret = kexec_purgatory_setup_sechdrs(pi, kbuf);
1036         if (ret)
1037                 goto out_free_kbuf;
1038
1039         ret = kexec_apply_relocations(image);
1040         if (ret)
1041                 goto out;
1042
1043         return 0;
1044 out:
1045         vfree(pi->sechdrs);
1046         pi->sechdrs = NULL;
1047 out_free_kbuf:
1048         vfree(pi->purgatory_buf);
1049         pi->purgatory_buf = NULL;
1050         return ret;
1051 }
1052
1053 /*
1054  * kexec_purgatory_find_symbol - find a symbol in the purgatory
1055  * @pi:         Purgatory to search in.
1056  * @name:       Name of the symbol.
1057  *
1058  * Return: pointer to symbol in read-only symtab on success, NULL on error.
1059  */
1060 static const Elf_Sym *kexec_purgatory_find_symbol(struct purgatory_info *pi,
1061                                                   const char *name)
1062 {
1063         const Elf_Shdr *sechdrs;
1064         const Elf_Ehdr *ehdr;
1065         const Elf_Sym *syms;
1066         const char *strtab;
1067         int i, k;
1068
1069         if (!pi->ehdr)
1070                 return NULL;
1071
1072         ehdr = pi->ehdr;
1073         sechdrs = (void *)ehdr + ehdr->e_shoff;
1074
1075         for (i = 0; i < ehdr->e_shnum; i++) {
1076                 if (sechdrs[i].sh_type != SHT_SYMTAB)
1077                         continue;
1078
1079                 if (sechdrs[i].sh_link >= ehdr->e_shnum)
1080                         /* Invalid strtab section number */
1081                         continue;
1082                 strtab = (void *)ehdr + sechdrs[sechdrs[i].sh_link].sh_offset;
1083                 syms = (void *)ehdr + sechdrs[i].sh_offset;
1084
1085                 /* Go through symbols for a match */
1086                 for (k = 0; k < sechdrs[i].sh_size/sizeof(Elf_Sym); k++) {
1087                         if (ELF_ST_BIND(syms[k].st_info) != STB_GLOBAL)
1088                                 continue;
1089
1090                         if (strcmp(strtab + syms[k].st_name, name) != 0)
1091                                 continue;
1092
1093                         if (syms[k].st_shndx == SHN_UNDEF ||
1094                             syms[k].st_shndx >= ehdr->e_shnum) {
1095                                 pr_debug("Symbol: %s has bad section index %d.\n",
1096                                                 name, syms[k].st_shndx);
1097                                 return NULL;
1098                         }
1099
1100                         /* Found the symbol we are looking for */
1101                         return &syms[k];
1102                 }
1103         }
1104
1105         return NULL;
1106 }
1107
1108 void *kexec_purgatory_get_symbol_addr(struct kimage *image, const char *name)
1109 {
1110         struct purgatory_info *pi = &image->purgatory_info;
1111         const Elf_Sym *sym;
1112         Elf_Shdr *sechdr;
1113
1114         sym = kexec_purgatory_find_symbol(pi, name);
1115         if (!sym)
1116                 return ERR_PTR(-EINVAL);
1117
1118         sechdr = &pi->sechdrs[sym->st_shndx];
1119
1120         /*
1121          * Returns the address where symbol will finally be loaded after
1122          * kexec_load_segment()
1123          */
1124         return (void *)(sechdr->sh_addr + sym->st_value);
1125 }
1126
1127 /*
1128  * Get or set value of a symbol. If "get_value" is true, symbol value is
1129  * returned in buf otherwise symbol value is set based on value in buf.
1130  */
1131 int kexec_purgatory_get_set_symbol(struct kimage *image, const char *name,
1132                                    void *buf, unsigned int size, bool get_value)
1133 {
1134         struct purgatory_info *pi = &image->purgatory_info;
1135         const Elf_Sym *sym;
1136         Elf_Shdr *sec;
1137         char *sym_buf;
1138
1139         sym = kexec_purgatory_find_symbol(pi, name);
1140         if (!sym)
1141                 return -EINVAL;
1142
1143         if (sym->st_size != size) {
1144                 pr_err("symbol %s size mismatch: expected %lu actual %u\n",
1145                        name, (unsigned long)sym->st_size, size);
1146                 return -EINVAL;
1147         }
1148
1149         sec = pi->sechdrs + sym->st_shndx;
1150
1151         if (sec->sh_type == SHT_NOBITS) {
1152                 pr_err("symbol %s is in a bss section. Cannot %s\n", name,
1153                        get_value ? "get" : "set");
1154                 return -EINVAL;
1155         }
1156
1157         sym_buf = (char *)pi->purgatory_buf + sec->sh_offset + sym->st_value;
1158
1159         if (get_value)
1160                 memcpy((void *)buf, sym_buf, size);
1161         else
1162                 memcpy((void *)sym_buf, buf, size);
1163
1164         return 0;
1165 }
1166 #endif /* CONFIG_ARCH_HAS_KEXEC_PURGATORY */
1167
1168 int crash_exclude_mem_range(struct crash_mem *mem,
1169                             unsigned long long mstart, unsigned long long mend)
1170 {
1171         int i, j;
1172         unsigned long long start, end;
1173         struct crash_mem_range temp_range = {0, 0};
1174
1175         for (i = 0; i < mem->nr_ranges; i++) {
1176                 start = mem->ranges[i].start;
1177                 end = mem->ranges[i].end;
1178
1179                 if (mstart > end || mend < start)
1180                         continue;
1181
1182                 /* Truncate any area outside of range */
1183                 if (mstart < start)
1184                         mstart = start;
1185                 if (mend > end)
1186                         mend = end;
1187
1188                 /* Found completely overlapping range */
1189                 if (mstart == start && mend == end) {
1190                         mem->ranges[i].start = 0;
1191                         mem->ranges[i].end = 0;
1192                         if (i < mem->nr_ranges - 1) {
1193                                 /* Shift rest of the ranges to left */
1194                                 for (j = i; j < mem->nr_ranges - 1; j++) {
1195                                         mem->ranges[j].start =
1196                                                 mem->ranges[j+1].start;
1197                                         mem->ranges[j].end =
1198                                                         mem->ranges[j+1].end;
1199                                 }
1200                         }
1201                         mem->nr_ranges--;
1202                         return 0;
1203                 }
1204
1205                 if (mstart > start && mend < end) {
1206                         /* Split original range */
1207                         mem->ranges[i].end = mstart - 1;
1208                         temp_range.start = mend + 1;
1209                         temp_range.end = end;
1210                 } else if (mstart != start)
1211                         mem->ranges[i].end = mstart - 1;
1212                 else
1213                         mem->ranges[i].start = mend + 1;
1214                 break;
1215         }
1216
1217         /* If a split happened, add the split to array */
1218         if (!temp_range.end)
1219                 return 0;
1220
1221         /* Split happened */
1222         if (i == mem->max_nr_ranges - 1)
1223                 return -ENOMEM;
1224
1225         /* Location where new range should go */
1226         j = i + 1;
1227         if (j < mem->nr_ranges) {
1228                 /* Move over all ranges one slot towards the end */
1229                 for (i = mem->nr_ranges - 1; i >= j; i--)
1230                         mem->ranges[i + 1] = mem->ranges[i];
1231         }
1232
1233         mem->ranges[j].start = temp_range.start;
1234         mem->ranges[j].end = temp_range.end;
1235         mem->nr_ranges++;
1236         return 0;
1237 }
1238
1239 int crash_prepare_elf64_headers(struct crash_mem *mem, int kernel_map,
1240                           void **addr, unsigned long *sz)
1241 {
1242         Elf64_Ehdr *ehdr;
1243         Elf64_Phdr *phdr;
1244         unsigned long nr_cpus = num_possible_cpus(), nr_phdr, elf_sz;
1245         unsigned char *buf;
1246         unsigned int cpu, i;
1247         unsigned long long notes_addr;
1248         unsigned long mstart, mend;
1249
1250         /* extra phdr for vmcoreinfo elf note */
1251         nr_phdr = nr_cpus + 1;
1252         nr_phdr += mem->nr_ranges;
1253
1254         /*
1255          * kexec-tools creates an extra PT_LOAD phdr for kernel text mapping
1256          * area (for example, ffffffff80000000 - ffffffffa0000000 on x86_64).
1257          * I think this is required by tools like gdb. So same physical
1258          * memory will be mapped in two elf headers. One will contain kernel
1259          * text virtual addresses and other will have __va(physical) addresses.
1260          */
1261
1262         nr_phdr++;
1263         elf_sz = sizeof(Elf64_Ehdr) + nr_phdr * sizeof(Elf64_Phdr);
1264         elf_sz = ALIGN(elf_sz, ELF_CORE_HEADER_ALIGN);
1265
1266         buf = vzalloc(elf_sz);
1267         if (!buf)
1268                 return -ENOMEM;
1269
1270         ehdr = (Elf64_Ehdr *)buf;
1271         phdr = (Elf64_Phdr *)(ehdr + 1);
1272         memcpy(ehdr->e_ident, ELFMAG, SELFMAG);
1273         ehdr->e_ident[EI_CLASS] = ELFCLASS64;
1274         ehdr->e_ident[EI_DATA] = ELFDATA2LSB;
1275         ehdr->e_ident[EI_VERSION] = EV_CURRENT;
1276         ehdr->e_ident[EI_OSABI] = ELF_OSABI;
1277         memset(ehdr->e_ident + EI_PAD, 0, EI_NIDENT - EI_PAD);
1278         ehdr->e_type = ET_CORE;
1279         ehdr->e_machine = ELF_ARCH;
1280         ehdr->e_version = EV_CURRENT;
1281         ehdr->e_phoff = sizeof(Elf64_Ehdr);
1282         ehdr->e_ehsize = sizeof(Elf64_Ehdr);
1283         ehdr->e_phentsize = sizeof(Elf64_Phdr);
1284
1285         /* Prepare one phdr of type PT_NOTE for each present cpu */
1286         for_each_present_cpu(cpu) {
1287                 phdr->p_type = PT_NOTE;
1288                 notes_addr = per_cpu_ptr_to_phys(per_cpu_ptr(crash_notes, cpu));
1289                 phdr->p_offset = phdr->p_paddr = notes_addr;
1290                 phdr->p_filesz = phdr->p_memsz = sizeof(note_buf_t);
1291                 (ehdr->e_phnum)++;
1292                 phdr++;
1293         }
1294
1295         /* Prepare one PT_NOTE header for vmcoreinfo */
1296         phdr->p_type = PT_NOTE;
1297         phdr->p_offset = phdr->p_paddr = paddr_vmcoreinfo_note();
1298         phdr->p_filesz = phdr->p_memsz = VMCOREINFO_NOTE_SIZE;
1299         (ehdr->e_phnum)++;
1300         phdr++;
1301
1302         /* Prepare PT_LOAD type program header for kernel text region */
1303         if (kernel_map) {
1304                 phdr->p_type = PT_LOAD;
1305                 phdr->p_flags = PF_R|PF_W|PF_X;
1306                 phdr->p_vaddr = (unsigned long) _text;
1307                 phdr->p_filesz = phdr->p_memsz = _end - _text;
1308                 phdr->p_offset = phdr->p_paddr = __pa_symbol(_text);
1309                 ehdr->e_phnum++;
1310                 phdr++;
1311         }
1312
1313         /* Go through all the ranges in mem->ranges[] and prepare phdr */
1314         for (i = 0; i < mem->nr_ranges; i++) {
1315                 mstart = mem->ranges[i].start;
1316                 mend = mem->ranges[i].end;
1317
1318                 phdr->p_type = PT_LOAD;
1319                 phdr->p_flags = PF_R|PF_W|PF_X;
1320                 phdr->p_offset  = mstart;
1321
1322                 phdr->p_paddr = mstart;
1323                 phdr->p_vaddr = (unsigned long) __va(mstart);
1324                 phdr->p_filesz = phdr->p_memsz = mend - mstart + 1;
1325                 phdr->p_align = 0;
1326                 ehdr->e_phnum++;
1327                 phdr++;
1328                 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",
1329                         phdr, phdr->p_vaddr, phdr->p_paddr, phdr->p_filesz,
1330                         ehdr->e_phnum, phdr->p_offset);
1331         }
1332
1333         *addr = buf;
1334         *sz = elf_sz;
1335         return 0;
1336 }