io_uring: kill an outdated comment
[platform/kernel/linux-starfive.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 /* Maximum size in bytes for kernel/initrd files. */
44 #define KEXEC_FILE_SIZE_MAX     min_t(s64, 4LL << 30, SSIZE_MAX)
45
46 /*
47  * Currently this is the only default function that is exported as some
48  * architectures need it to do additional handlings.
49  * In the future, other default functions may be exported too if required.
50  */
51 int kexec_image_probe_default(struct kimage *image, void *buf,
52                               unsigned long buf_len)
53 {
54         const struct kexec_file_ops * const *fops;
55         int ret = -ENOEXEC;
56
57         for (fops = &kexec_file_loaders[0]; *fops && (*fops)->probe; ++fops) {
58                 ret = (*fops)->probe(buf, buf_len);
59                 if (!ret) {
60                         image->fops = *fops;
61                         return ret;
62                 }
63         }
64
65         return ret;
66 }
67
68 void *kexec_image_load_default(struct kimage *image)
69 {
70         if (!image->fops || !image->fops->load)
71                 return ERR_PTR(-ENOEXEC);
72
73         return image->fops->load(image, image->kernel_buf,
74                                  image->kernel_buf_len, image->initrd_buf,
75                                  image->initrd_buf_len, image->cmdline_buf,
76                                  image->cmdline_buf_len);
77 }
78
79 int kexec_image_post_load_cleanup_default(struct kimage *image)
80 {
81         if (!image->fops || !image->fops->cleanup)
82                 return 0;
83
84         return image->fops->cleanup(image->image_loader_data);
85 }
86
87 /*
88  * Free up memory used by kernel, initrd, and command line. This is temporary
89  * memory allocation which is not needed any more after these buffers have
90  * been loaded into separate segments and have been copied elsewhere.
91  */
92 void kimage_file_post_load_cleanup(struct kimage *image)
93 {
94         struct purgatory_info *pi = &image->purgatory_info;
95
96         vfree(image->kernel_buf);
97         image->kernel_buf = NULL;
98
99         vfree(image->initrd_buf);
100         image->initrd_buf = NULL;
101
102         kfree(image->cmdline_buf);
103         image->cmdline_buf = NULL;
104
105         vfree(pi->purgatory_buf);
106         pi->purgatory_buf = NULL;
107
108         vfree(pi->sechdrs);
109         pi->sechdrs = NULL;
110
111 #ifdef CONFIG_IMA_KEXEC
112         vfree(image->ima_buffer);
113         image->ima_buffer = NULL;
114 #endif /* CONFIG_IMA_KEXEC */
115
116         /* See if architecture has anything to cleanup post load */
117         arch_kimage_file_post_load_cleanup(image);
118
119         /*
120          * Above call should have called into bootloader to free up
121          * any data stored in kimage->image_loader_data. It should
122          * be ok now to free it up.
123          */
124         kfree(image->image_loader_data);
125         image->image_loader_data = NULL;
126 }
127
128 #ifdef CONFIG_KEXEC_SIG
129 #ifdef CONFIG_SIGNED_PE_FILE_VERIFICATION
130 int kexec_kernel_verify_pe_sig(const char *kernel, unsigned long kernel_len)
131 {
132         int ret;
133
134         ret = verify_pefile_signature(kernel, kernel_len,
135                                       VERIFY_USE_SECONDARY_KEYRING,
136                                       VERIFYING_KEXEC_PE_SIGNATURE);
137         if (ret == -ENOKEY && IS_ENABLED(CONFIG_INTEGRITY_PLATFORM_KEYRING)) {
138                 ret = verify_pefile_signature(kernel, kernel_len,
139                                               VERIFY_USE_PLATFORM_KEYRING,
140                                               VERIFYING_KEXEC_PE_SIGNATURE);
141         }
142         return ret;
143 }
144 #endif
145
146 static int kexec_image_verify_sig(struct kimage *image, void *buf,
147                                   unsigned long buf_len)
148 {
149         if (!image->fops || !image->fops->verify_sig) {
150                 pr_debug("kernel loader does not support signature verification.\n");
151                 return -EKEYREJECTED;
152         }
153
154         return image->fops->verify_sig(buf, buf_len);
155 }
156
157 static int
158 kimage_validate_signature(struct kimage *image)
159 {
160         int ret;
161
162         ret = kexec_image_verify_sig(image, image->kernel_buf,
163                                      image->kernel_buf_len);
164         if (ret) {
165
166                 if (sig_enforce) {
167                         pr_notice("Enforced kernel signature verification failed (%d).\n", ret);
168                         return ret;
169                 }
170
171                 /*
172                  * If IMA is guaranteed to appraise a signature on the kexec
173                  * image, permit it even if the kernel is otherwise locked
174                  * down.
175                  */
176                 if (!ima_appraise_signature(READING_KEXEC_IMAGE) &&
177                     security_locked_down(LOCKDOWN_KEXEC))
178                         return -EPERM;
179
180                 pr_debug("kernel signature verification failed (%d).\n", ret);
181         }
182
183         return 0;
184 }
185 #endif
186
187 /*
188  * In file mode list of segments is prepared by kernel. Copy relevant
189  * data from user space, do error checking, prepare segment list
190  */
191 static int
192 kimage_file_prepare_segments(struct kimage *image, int kernel_fd, int initrd_fd,
193                              const char __user *cmdline_ptr,
194                              unsigned long cmdline_len, unsigned flags)
195 {
196         ssize_t ret;
197         void *ldata;
198
199         ret = kernel_read_file_from_fd(kernel_fd, 0, &image->kernel_buf,
200                                        KEXEC_FILE_SIZE_MAX, NULL,
201                                        READING_KEXEC_IMAGE);
202         if (ret < 0)
203                 return ret;
204         image->kernel_buf_len = ret;
205
206         /* Call arch image probe handlers */
207         ret = arch_kexec_kernel_image_probe(image, image->kernel_buf,
208                                             image->kernel_buf_len);
209         if (ret)
210                 goto out;
211
212 #ifdef CONFIG_KEXEC_SIG
213         ret = kimage_validate_signature(image);
214
215         if (ret)
216                 goto out;
217 #endif
218         /* It is possible that there no initramfs is being loaded */
219         if (!(flags & KEXEC_FILE_NO_INITRAMFS)) {
220                 ret = kernel_read_file_from_fd(initrd_fd, 0, &image->initrd_buf,
221                                                KEXEC_FILE_SIZE_MAX, NULL,
222                                                READING_KEXEC_INITRAMFS);
223                 if (ret < 0)
224                         goto out;
225                 image->initrd_buf_len = ret;
226                 ret = 0;
227         }
228
229         if (cmdline_len) {
230                 image->cmdline_buf = memdup_user(cmdline_ptr, cmdline_len);
231                 if (IS_ERR(image->cmdline_buf)) {
232                         ret = PTR_ERR(image->cmdline_buf);
233                         image->cmdline_buf = NULL;
234                         goto out;
235                 }
236
237                 image->cmdline_buf_len = cmdline_len;
238
239                 /* command line should be a string with last byte null */
240                 if (image->cmdline_buf[cmdline_len - 1] != '\0') {
241                         ret = -EINVAL;
242                         goto out;
243                 }
244
245                 ima_kexec_cmdline(kernel_fd, image->cmdline_buf,
246                                   image->cmdline_buf_len - 1);
247         }
248
249         /* IMA needs to pass the measurement list to the next kernel. */
250         ima_add_kexec_buffer(image);
251
252         /* Call arch image load handlers */
253         ldata = arch_kexec_kernel_image_load(image);
254
255         if (IS_ERR(ldata)) {
256                 ret = PTR_ERR(ldata);
257                 goto out;
258         }
259
260         image->image_loader_data = ldata;
261 out:
262         /* In case of error, free up all allocated memory in this function */
263         if (ret)
264                 kimage_file_post_load_cleanup(image);
265         return ret;
266 }
267
268 static int
269 kimage_file_alloc_init(struct kimage **rimage, int kernel_fd,
270                        int initrd_fd, const char __user *cmdline_ptr,
271                        unsigned long cmdline_len, unsigned long flags)
272 {
273         int ret;
274         struct kimage *image;
275         bool kexec_on_panic = flags & KEXEC_FILE_ON_CRASH;
276
277         image = do_kimage_alloc_init();
278         if (!image)
279                 return -ENOMEM;
280
281         image->file_mode = 1;
282
283         if (kexec_on_panic) {
284                 /* Enable special crash kernel control page alloc policy. */
285                 image->control_page = crashk_res.start;
286                 image->type = KEXEC_TYPE_CRASH;
287         }
288
289         ret = kimage_file_prepare_segments(image, kernel_fd, initrd_fd,
290                                            cmdline_ptr, cmdline_len, flags);
291         if (ret)
292                 goto out_free_image;
293
294         ret = sanity_check_segment_list(image);
295         if (ret)
296                 goto out_free_post_load_bufs;
297
298         ret = -ENOMEM;
299         image->control_code_page = kimage_alloc_control_pages(image,
300                                            get_order(KEXEC_CONTROL_PAGE_SIZE));
301         if (!image->control_code_page) {
302                 pr_err("Could not allocate control_code_buffer\n");
303                 goto out_free_post_load_bufs;
304         }
305
306         if (!kexec_on_panic) {
307                 image->swap_page = kimage_alloc_control_pages(image, 0);
308                 if (!image->swap_page) {
309                         pr_err("Could not allocate swap buffer\n");
310                         goto out_free_control_pages;
311                 }
312         }
313
314         *rimage = image;
315         return 0;
316 out_free_control_pages:
317         kimage_free_page_list(&image->control_pages);
318 out_free_post_load_bufs:
319         kimage_file_post_load_cleanup(image);
320 out_free_image:
321         kfree(image);
322         return ret;
323 }
324
325 SYSCALL_DEFINE5(kexec_file_load, int, kernel_fd, int, initrd_fd,
326                 unsigned long, cmdline_len, const char __user *, cmdline_ptr,
327                 unsigned long, flags)
328 {
329         int ret = 0, i;
330         struct kimage **dest_image, *image;
331
332         /* We only trust the superuser with rebooting the system. */
333         if (!capable(CAP_SYS_BOOT) || kexec_load_disabled)
334                 return -EPERM;
335
336         /* Make sure we have a legal set of flags */
337         if (flags != (flags & KEXEC_FILE_FLAGS))
338                 return -EINVAL;
339
340         image = NULL;
341
342         if (!mutex_trylock(&kexec_mutex))
343                 return -EBUSY;
344
345         dest_image = &kexec_image;
346         if (flags & KEXEC_FILE_ON_CRASH) {
347                 dest_image = &kexec_crash_image;
348                 if (kexec_crash_image)
349                         arch_kexec_unprotect_crashkres();
350         }
351
352         if (flags & KEXEC_FILE_UNLOAD)
353                 goto exchange;
354
355         /*
356          * In case of crash, new kernel gets loaded in reserved region. It is
357          * same memory where old crash kernel might be loaded. Free any
358          * current crash dump kernel before we corrupt it.
359          */
360         if (flags & KEXEC_FILE_ON_CRASH)
361                 kimage_free(xchg(&kexec_crash_image, NULL));
362
363         ret = kimage_file_alloc_init(&image, kernel_fd, initrd_fd, cmdline_ptr,
364                                      cmdline_len, flags);
365         if (ret)
366                 goto out;
367
368         ret = machine_kexec_prepare(image);
369         if (ret)
370                 goto out;
371
372         /*
373          * Some architecture(like S390) may touch the crash memory before
374          * machine_kexec_prepare(), we must copy vmcoreinfo data after it.
375          */
376         ret = kimage_crash_copy_vmcoreinfo(image);
377         if (ret)
378                 goto out;
379
380         ret = kexec_calculate_store_digests(image);
381         if (ret)
382                 goto out;
383
384         for (i = 0; i < image->nr_segments; i++) {
385                 struct kexec_segment *ksegment;
386
387                 ksegment = &image->segment[i];
388                 pr_debug("Loading segment %d: buf=0x%p bufsz=0x%zx mem=0x%lx memsz=0x%zx\n",
389                          i, ksegment->buf, ksegment->bufsz, ksegment->mem,
390                          ksegment->memsz);
391
392                 ret = kimage_load_segment(image, &image->segment[i]);
393                 if (ret)
394                         goto out;
395         }
396
397         kimage_terminate(image);
398
399         ret = machine_kexec_post_load(image);
400         if (ret)
401                 goto out;
402
403         /*
404          * Free up any temporary buffers allocated which are not needed
405          * after image has been loaded
406          */
407         kimage_file_post_load_cleanup(image);
408 exchange:
409         image = xchg(dest_image, image);
410 out:
411         if ((flags & KEXEC_FILE_ON_CRASH) && kexec_crash_image)
412                 arch_kexec_protect_crashkres();
413
414         mutex_unlock(&kexec_mutex);
415         kimage_free(image);
416         return ret;
417 }
418
419 static int locate_mem_hole_top_down(unsigned long start, unsigned long end,
420                                     struct kexec_buf *kbuf)
421 {
422         struct kimage *image = kbuf->image;
423         unsigned long temp_start, temp_end;
424
425         temp_end = min(end, kbuf->buf_max);
426         temp_start = temp_end - kbuf->memsz;
427
428         do {
429                 /* align down start */
430                 temp_start = temp_start & (~(kbuf->buf_align - 1));
431
432                 if (temp_start < start || temp_start < kbuf->buf_min)
433                         return 0;
434
435                 temp_end = temp_start + kbuf->memsz - 1;
436
437                 /*
438                  * Make sure this does not conflict with any of existing
439                  * segments
440                  */
441                 if (kimage_is_destination_range(image, temp_start, temp_end)) {
442                         temp_start = temp_start - PAGE_SIZE;
443                         continue;
444                 }
445
446                 /* We found a suitable memory range */
447                 break;
448         } while (1);
449
450         /* If we are here, we found a suitable memory range */
451         kbuf->mem = temp_start;
452
453         /* Success, stop navigating through remaining System RAM ranges */
454         return 1;
455 }
456
457 static int locate_mem_hole_bottom_up(unsigned long start, unsigned long end,
458                                      struct kexec_buf *kbuf)
459 {
460         struct kimage *image = kbuf->image;
461         unsigned long temp_start, temp_end;
462
463         temp_start = max(start, kbuf->buf_min);
464
465         do {
466                 temp_start = ALIGN(temp_start, kbuf->buf_align);
467                 temp_end = temp_start + kbuf->memsz - 1;
468
469                 if (temp_end > end || temp_end > kbuf->buf_max)
470                         return 0;
471                 /*
472                  * Make sure this does not conflict with any of existing
473                  * segments
474                  */
475                 if (kimage_is_destination_range(image, temp_start, temp_end)) {
476                         temp_start = temp_start + PAGE_SIZE;
477                         continue;
478                 }
479
480                 /* We found a suitable memory range */
481                 break;
482         } while (1);
483
484         /* If we are here, we found a suitable memory range */
485         kbuf->mem = temp_start;
486
487         /* Success, stop navigating through remaining System RAM ranges */
488         return 1;
489 }
490
491 static int locate_mem_hole_callback(struct resource *res, void *arg)
492 {
493         struct kexec_buf *kbuf = (struct kexec_buf *)arg;
494         u64 start = res->start, end = res->end;
495         unsigned long sz = end - start + 1;
496
497         /* Returning 0 will take to next memory range */
498
499         /* Don't use memory that will be detected and handled by a driver. */
500         if (res->flags & IORESOURCE_SYSRAM_DRIVER_MANAGED)
501                 return 0;
502
503         if (sz < kbuf->memsz)
504                 return 0;
505
506         if (end < kbuf->buf_min || start > kbuf->buf_max)
507                 return 0;
508
509         /*
510          * Allocate memory top down with-in ram range. Otherwise bottom up
511          * allocation.
512          */
513         if (kbuf->top_down)
514                 return locate_mem_hole_top_down(start, end, kbuf);
515         return locate_mem_hole_bottom_up(start, end, kbuf);
516 }
517
518 #ifdef CONFIG_ARCH_KEEP_MEMBLOCK
519 static int kexec_walk_memblock(struct kexec_buf *kbuf,
520                                int (*func)(struct resource *, void *))
521 {
522         int ret = 0;
523         u64 i;
524         phys_addr_t mstart, mend;
525         struct resource res = { };
526
527         if (kbuf->image->type == KEXEC_TYPE_CRASH)
528                 return func(&crashk_res, kbuf);
529
530         /*
531          * Using MEMBLOCK_NONE will properly skip MEMBLOCK_DRIVER_MANAGED. See
532          * IORESOURCE_SYSRAM_DRIVER_MANAGED handling in
533          * locate_mem_hole_callback().
534          */
535         if (kbuf->top_down) {
536                 for_each_free_mem_range_reverse(i, NUMA_NO_NODE, MEMBLOCK_NONE,
537                                                 &mstart, &mend, NULL) {
538                         /*
539                          * In memblock, end points to the first byte after the
540                          * range while in kexec, end points to the last byte
541                          * in the range.
542                          */
543                         res.start = mstart;
544                         res.end = mend - 1;
545                         ret = func(&res, kbuf);
546                         if (ret)
547                                 break;
548                 }
549         } else {
550                 for_each_free_mem_range(i, NUMA_NO_NODE, MEMBLOCK_NONE,
551                                         &mstart, &mend, NULL) {
552                         /*
553                          * In memblock, end points to the first byte after the
554                          * range while in kexec, end points to the last byte
555                          * in the range.
556                          */
557                         res.start = mstart;
558                         res.end = mend - 1;
559                         ret = func(&res, kbuf);
560                         if (ret)
561                                 break;
562                 }
563         }
564
565         return ret;
566 }
567 #else
568 static int kexec_walk_memblock(struct kexec_buf *kbuf,
569                                int (*func)(struct resource *, void *))
570 {
571         return 0;
572 }
573 #endif
574
575 /**
576  * kexec_walk_resources - call func(data) on free memory regions
577  * @kbuf:       Context info for the search. Also passed to @func.
578  * @func:       Function to call for each memory region.
579  *
580  * Return: The memory walk will stop when func returns a non-zero value
581  * and that value will be returned. If all free regions are visited without
582  * func returning non-zero, then zero will be returned.
583  */
584 static int kexec_walk_resources(struct kexec_buf *kbuf,
585                                 int (*func)(struct resource *, void *))
586 {
587         if (kbuf->image->type == KEXEC_TYPE_CRASH)
588                 return walk_iomem_res_desc(crashk_res.desc,
589                                            IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY,
590                                            crashk_res.start, crashk_res.end,
591                                            kbuf, func);
592         else
593                 return walk_system_ram_res(0, ULONG_MAX, kbuf, func);
594 }
595
596 /**
597  * kexec_locate_mem_hole - find free memory for the purgatory or the next kernel
598  * @kbuf:       Parameters for the memory search.
599  *
600  * On success, kbuf->mem will have the start address of the memory region found.
601  *
602  * Return: 0 on success, negative errno on error.
603  */
604 int kexec_locate_mem_hole(struct kexec_buf *kbuf)
605 {
606         int ret;
607
608         /* Arch knows where to place */
609         if (kbuf->mem != KEXEC_BUF_MEM_UNKNOWN)
610                 return 0;
611
612         if (!IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK))
613                 ret = kexec_walk_resources(kbuf, locate_mem_hole_callback);
614         else
615                 ret = kexec_walk_memblock(kbuf, locate_mem_hole_callback);
616
617         return ret == 1 ? 0 : -EADDRNOTAVAIL;
618 }
619
620 /**
621  * kexec_add_buffer - place a buffer in a kexec segment
622  * @kbuf:       Buffer contents and memory parameters.
623  *
624  * This function assumes that kexec_mutex is held.
625  * On successful return, @kbuf->mem will have the physical address of
626  * the buffer in memory.
627  *
628  * Return: 0 on success, negative errno on error.
629  */
630 int kexec_add_buffer(struct kexec_buf *kbuf)
631 {
632         struct kexec_segment *ksegment;
633         int ret;
634
635         /* Currently adding segment this way is allowed only in file mode */
636         if (!kbuf->image->file_mode)
637                 return -EINVAL;
638
639         if (kbuf->image->nr_segments >= KEXEC_SEGMENT_MAX)
640                 return -EINVAL;
641
642         /*
643          * Make sure we are not trying to add buffer after allocating
644          * control pages. All segments need to be placed first before
645          * any control pages are allocated. As control page allocation
646          * logic goes through list of segments to make sure there are
647          * no destination overlaps.
648          */
649         if (!list_empty(&kbuf->image->control_pages)) {
650                 WARN_ON(1);
651                 return -EINVAL;
652         }
653
654         /* Ensure minimum alignment needed for segments. */
655         kbuf->memsz = ALIGN(kbuf->memsz, PAGE_SIZE);
656         kbuf->buf_align = max(kbuf->buf_align, PAGE_SIZE);
657
658         /* Walk the RAM ranges and allocate a suitable range for the buffer */
659         ret = arch_kexec_locate_mem_hole(kbuf);
660         if (ret)
661                 return ret;
662
663         /* Found a suitable memory range */
664         ksegment = &kbuf->image->segment[kbuf->image->nr_segments];
665         ksegment->kbuf = kbuf->buffer;
666         ksegment->bufsz = kbuf->bufsz;
667         ksegment->mem = kbuf->mem;
668         ksegment->memsz = kbuf->memsz;
669         kbuf->image->nr_segments++;
670         return 0;
671 }
672
673 /* Calculate and store the digest of segments */
674 static int kexec_calculate_store_digests(struct kimage *image)
675 {
676         struct crypto_shash *tfm;
677         struct shash_desc *desc;
678         int ret = 0, i, j, zero_buf_sz, sha_region_sz;
679         size_t desc_size, nullsz;
680         char *digest;
681         void *zero_buf;
682         struct kexec_sha_region *sha_regions;
683         struct purgatory_info *pi = &image->purgatory_info;
684
685         if (!IS_ENABLED(CONFIG_ARCH_HAS_KEXEC_PURGATORY))
686                 return 0;
687
688         zero_buf = __va(page_to_pfn(ZERO_PAGE(0)) << PAGE_SHIFT);
689         zero_buf_sz = PAGE_SIZE;
690
691         tfm = crypto_alloc_shash("sha256", 0, 0);
692         if (IS_ERR(tfm)) {
693                 ret = PTR_ERR(tfm);
694                 goto out;
695         }
696
697         desc_size = crypto_shash_descsize(tfm) + sizeof(*desc);
698         desc = kzalloc(desc_size, GFP_KERNEL);
699         if (!desc) {
700                 ret = -ENOMEM;
701                 goto out_free_tfm;
702         }
703
704         sha_region_sz = KEXEC_SEGMENT_MAX * sizeof(struct kexec_sha_region);
705         sha_regions = vzalloc(sha_region_sz);
706         if (!sha_regions) {
707                 ret = -ENOMEM;
708                 goto out_free_desc;
709         }
710
711         desc->tfm   = tfm;
712
713         ret = crypto_shash_init(desc);
714         if (ret < 0)
715                 goto out_free_sha_regions;
716
717         digest = kzalloc(SHA256_DIGEST_SIZE, GFP_KERNEL);
718         if (!digest) {
719                 ret = -ENOMEM;
720                 goto out_free_sha_regions;
721         }
722
723         for (j = i = 0; i < image->nr_segments; i++) {
724                 struct kexec_segment *ksegment;
725
726                 ksegment = &image->segment[i];
727                 /*
728                  * Skip purgatory as it will be modified once we put digest
729                  * info in purgatory.
730                  */
731                 if (ksegment->kbuf == pi->purgatory_buf)
732                         continue;
733
734                 ret = crypto_shash_update(desc, ksegment->kbuf,
735                                           ksegment->bufsz);
736                 if (ret)
737                         break;
738
739                 /*
740                  * Assume rest of the buffer is filled with zero and
741                  * update digest accordingly.
742                  */
743                 nullsz = ksegment->memsz - ksegment->bufsz;
744                 while (nullsz) {
745                         unsigned long bytes = nullsz;
746
747                         if (bytes > zero_buf_sz)
748                                 bytes = zero_buf_sz;
749                         ret = crypto_shash_update(desc, zero_buf, bytes);
750                         if (ret)
751                                 break;
752                         nullsz -= bytes;
753                 }
754
755                 if (ret)
756                         break;
757
758                 sha_regions[j].start = ksegment->mem;
759                 sha_regions[j].len = ksegment->memsz;
760                 j++;
761         }
762
763         if (!ret) {
764                 ret = crypto_shash_final(desc, digest);
765                 if (ret)
766                         goto out_free_digest;
767                 ret = kexec_purgatory_get_set_symbol(image, "purgatory_sha_regions",
768                                                      sha_regions, sha_region_sz, 0);
769                 if (ret)
770                         goto out_free_digest;
771
772                 ret = kexec_purgatory_get_set_symbol(image, "purgatory_sha256_digest",
773                                                      digest, SHA256_DIGEST_SIZE, 0);
774                 if (ret)
775                         goto out_free_digest;
776         }
777
778 out_free_digest:
779         kfree(digest);
780 out_free_sha_regions:
781         vfree(sha_regions);
782 out_free_desc:
783         kfree(desc);
784 out_free_tfm:
785         kfree(tfm);
786 out:
787         return ret;
788 }
789
790 #ifdef CONFIG_ARCH_HAS_KEXEC_PURGATORY
791 /*
792  * kexec_purgatory_setup_kbuf - prepare buffer to load purgatory.
793  * @pi:         Purgatory to be loaded.
794  * @kbuf:       Buffer to setup.
795  *
796  * Allocates the memory needed for the buffer. Caller is responsible to free
797  * the memory after use.
798  *
799  * Return: 0 on success, negative errno on error.
800  */
801 static int kexec_purgatory_setup_kbuf(struct purgatory_info *pi,
802                                       struct kexec_buf *kbuf)
803 {
804         const Elf_Shdr *sechdrs;
805         unsigned long bss_align;
806         unsigned long bss_sz;
807         unsigned long align;
808         int i, ret;
809
810         sechdrs = (void *)pi->ehdr + pi->ehdr->e_shoff;
811         kbuf->buf_align = bss_align = 1;
812         kbuf->bufsz = bss_sz = 0;
813
814         for (i = 0; i < pi->ehdr->e_shnum; i++) {
815                 if (!(sechdrs[i].sh_flags & SHF_ALLOC))
816                         continue;
817
818                 align = sechdrs[i].sh_addralign;
819                 if (sechdrs[i].sh_type != SHT_NOBITS) {
820                         if (kbuf->buf_align < align)
821                                 kbuf->buf_align = align;
822                         kbuf->bufsz = ALIGN(kbuf->bufsz, align);
823                         kbuf->bufsz += sechdrs[i].sh_size;
824                 } else {
825                         if (bss_align < align)
826                                 bss_align = align;
827                         bss_sz = ALIGN(bss_sz, align);
828                         bss_sz += sechdrs[i].sh_size;
829                 }
830         }
831         kbuf->bufsz = ALIGN(kbuf->bufsz, bss_align);
832         kbuf->memsz = kbuf->bufsz + bss_sz;
833         if (kbuf->buf_align < bss_align)
834                 kbuf->buf_align = bss_align;
835
836         kbuf->buffer = vzalloc(kbuf->bufsz);
837         if (!kbuf->buffer)
838                 return -ENOMEM;
839         pi->purgatory_buf = kbuf->buffer;
840
841         ret = kexec_add_buffer(kbuf);
842         if (ret)
843                 goto out;
844
845         return 0;
846 out:
847         vfree(pi->purgatory_buf);
848         pi->purgatory_buf = NULL;
849         return ret;
850 }
851
852 /*
853  * kexec_purgatory_setup_sechdrs - prepares the pi->sechdrs buffer.
854  * @pi:         Purgatory to be loaded.
855  * @kbuf:       Buffer prepared to store purgatory.
856  *
857  * Allocates the memory needed for the buffer. Caller is responsible to free
858  * the memory after use.
859  *
860  * Return: 0 on success, negative errno on error.
861  */
862 static int kexec_purgatory_setup_sechdrs(struct purgatory_info *pi,
863                                          struct kexec_buf *kbuf)
864 {
865         unsigned long bss_addr;
866         unsigned long offset;
867         Elf_Shdr *sechdrs;
868         int i;
869
870         /*
871          * The section headers in kexec_purgatory are read-only. In order to
872          * have them modifiable make a temporary copy.
873          */
874         sechdrs = vzalloc(array_size(sizeof(Elf_Shdr), pi->ehdr->e_shnum));
875         if (!sechdrs)
876                 return -ENOMEM;
877         memcpy(sechdrs, (void *)pi->ehdr + pi->ehdr->e_shoff,
878                pi->ehdr->e_shnum * sizeof(Elf_Shdr));
879         pi->sechdrs = sechdrs;
880
881         offset = 0;
882         bss_addr = kbuf->mem + kbuf->bufsz;
883         kbuf->image->start = pi->ehdr->e_entry;
884
885         for (i = 0; i < pi->ehdr->e_shnum; i++) {
886                 unsigned long align;
887                 void *src, *dst;
888
889                 if (!(sechdrs[i].sh_flags & SHF_ALLOC))
890                         continue;
891
892                 align = sechdrs[i].sh_addralign;
893                 if (sechdrs[i].sh_type == SHT_NOBITS) {
894                         bss_addr = ALIGN(bss_addr, align);
895                         sechdrs[i].sh_addr = bss_addr;
896                         bss_addr += sechdrs[i].sh_size;
897                         continue;
898                 }
899
900                 offset = ALIGN(offset, align);
901                 if (sechdrs[i].sh_flags & SHF_EXECINSTR &&
902                     pi->ehdr->e_entry >= sechdrs[i].sh_addr &&
903                     pi->ehdr->e_entry < (sechdrs[i].sh_addr
904                                          + sechdrs[i].sh_size)) {
905                         kbuf->image->start -= sechdrs[i].sh_addr;
906                         kbuf->image->start += kbuf->mem + offset;
907                 }
908
909                 src = (void *)pi->ehdr + sechdrs[i].sh_offset;
910                 dst = pi->purgatory_buf + offset;
911                 memcpy(dst, src, sechdrs[i].sh_size);
912
913                 sechdrs[i].sh_addr = kbuf->mem + offset;
914                 sechdrs[i].sh_offset = offset;
915                 offset += sechdrs[i].sh_size;
916         }
917
918         return 0;
919 }
920
921 static int kexec_apply_relocations(struct kimage *image)
922 {
923         int i, ret;
924         struct purgatory_info *pi = &image->purgatory_info;
925         const Elf_Shdr *sechdrs;
926
927         sechdrs = (void *)pi->ehdr + pi->ehdr->e_shoff;
928
929         for (i = 0; i < pi->ehdr->e_shnum; i++) {
930                 const Elf_Shdr *relsec;
931                 const Elf_Shdr *symtab;
932                 Elf_Shdr *section;
933
934                 relsec = sechdrs + i;
935
936                 if (relsec->sh_type != SHT_RELA &&
937                     relsec->sh_type != SHT_REL)
938                         continue;
939
940                 /*
941                  * For section of type SHT_RELA/SHT_REL,
942                  * ->sh_link contains section header index of associated
943                  * symbol table. And ->sh_info contains section header
944                  * index of section to which relocations apply.
945                  */
946                 if (relsec->sh_info >= pi->ehdr->e_shnum ||
947                     relsec->sh_link >= pi->ehdr->e_shnum)
948                         return -ENOEXEC;
949
950                 section = pi->sechdrs + relsec->sh_info;
951                 symtab = sechdrs + relsec->sh_link;
952
953                 if (!(section->sh_flags & SHF_ALLOC))
954                         continue;
955
956                 /*
957                  * symtab->sh_link contain section header index of associated
958                  * string table.
959                  */
960                 if (symtab->sh_link >= pi->ehdr->e_shnum)
961                         /* Invalid section number? */
962                         continue;
963
964                 /*
965                  * Respective architecture needs to provide support for applying
966                  * relocations of type SHT_RELA/SHT_REL.
967                  */
968                 if (relsec->sh_type == SHT_RELA)
969                         ret = arch_kexec_apply_relocations_add(pi, section,
970                                                                relsec, symtab);
971                 else if (relsec->sh_type == SHT_REL)
972                         ret = arch_kexec_apply_relocations(pi, section,
973                                                            relsec, symtab);
974                 if (ret)
975                         return ret;
976         }
977
978         return 0;
979 }
980
981 /*
982  * kexec_load_purgatory - Load and relocate the purgatory object.
983  * @image:      Image to add the purgatory to.
984  * @kbuf:       Memory parameters to use.
985  *
986  * Allocates the memory needed for image->purgatory_info.sechdrs and
987  * image->purgatory_info.purgatory_buf/kbuf->buffer. Caller is responsible
988  * to free the memory after use.
989  *
990  * Return: 0 on success, negative errno on error.
991  */
992 int kexec_load_purgatory(struct kimage *image, struct kexec_buf *kbuf)
993 {
994         struct purgatory_info *pi = &image->purgatory_info;
995         int ret;
996
997         if (kexec_purgatory_size <= 0)
998                 return -EINVAL;
999
1000         pi->ehdr = (const Elf_Ehdr *)kexec_purgatory;
1001
1002         ret = kexec_purgatory_setup_kbuf(pi, kbuf);
1003         if (ret)
1004                 return ret;
1005
1006         ret = kexec_purgatory_setup_sechdrs(pi, kbuf);
1007         if (ret)
1008                 goto out_free_kbuf;
1009
1010         ret = kexec_apply_relocations(image);
1011         if (ret)
1012                 goto out;
1013
1014         return 0;
1015 out:
1016         vfree(pi->sechdrs);
1017         pi->sechdrs = NULL;
1018 out_free_kbuf:
1019         vfree(pi->purgatory_buf);
1020         pi->purgatory_buf = NULL;
1021         return ret;
1022 }
1023
1024 /*
1025  * kexec_purgatory_find_symbol - find a symbol in the purgatory
1026  * @pi:         Purgatory to search in.
1027  * @name:       Name of the symbol.
1028  *
1029  * Return: pointer to symbol in read-only symtab on success, NULL on error.
1030  */
1031 static const Elf_Sym *kexec_purgatory_find_symbol(struct purgatory_info *pi,
1032                                                   const char *name)
1033 {
1034         const Elf_Shdr *sechdrs;
1035         const Elf_Ehdr *ehdr;
1036         const Elf_Sym *syms;
1037         const char *strtab;
1038         int i, k;
1039
1040         if (!pi->ehdr)
1041                 return NULL;
1042
1043         ehdr = pi->ehdr;
1044         sechdrs = (void *)ehdr + ehdr->e_shoff;
1045
1046         for (i = 0; i < ehdr->e_shnum; i++) {
1047                 if (sechdrs[i].sh_type != SHT_SYMTAB)
1048                         continue;
1049
1050                 if (sechdrs[i].sh_link >= ehdr->e_shnum)
1051                         /* Invalid strtab section number */
1052                         continue;
1053                 strtab = (void *)ehdr + sechdrs[sechdrs[i].sh_link].sh_offset;
1054                 syms = (void *)ehdr + sechdrs[i].sh_offset;
1055
1056                 /* Go through symbols for a match */
1057                 for (k = 0; k < sechdrs[i].sh_size/sizeof(Elf_Sym); k++) {
1058                         if (ELF_ST_BIND(syms[k].st_info) != STB_GLOBAL)
1059                                 continue;
1060
1061                         if (strcmp(strtab + syms[k].st_name, name) != 0)
1062                                 continue;
1063
1064                         if (syms[k].st_shndx == SHN_UNDEF ||
1065                             syms[k].st_shndx >= ehdr->e_shnum) {
1066                                 pr_debug("Symbol: %s has bad section index %d.\n",
1067                                                 name, syms[k].st_shndx);
1068                                 return NULL;
1069                         }
1070
1071                         /* Found the symbol we are looking for */
1072                         return &syms[k];
1073                 }
1074         }
1075
1076         return NULL;
1077 }
1078
1079 void *kexec_purgatory_get_symbol_addr(struct kimage *image, const char *name)
1080 {
1081         struct purgatory_info *pi = &image->purgatory_info;
1082         const Elf_Sym *sym;
1083         Elf_Shdr *sechdr;
1084
1085         sym = kexec_purgatory_find_symbol(pi, name);
1086         if (!sym)
1087                 return ERR_PTR(-EINVAL);
1088
1089         sechdr = &pi->sechdrs[sym->st_shndx];
1090
1091         /*
1092          * Returns the address where symbol will finally be loaded after
1093          * kexec_load_segment()
1094          */
1095         return (void *)(sechdr->sh_addr + sym->st_value);
1096 }
1097
1098 /*
1099  * Get or set value of a symbol. If "get_value" is true, symbol value is
1100  * returned in buf otherwise symbol value is set based on value in buf.
1101  */
1102 int kexec_purgatory_get_set_symbol(struct kimage *image, const char *name,
1103                                    void *buf, unsigned int size, bool get_value)
1104 {
1105         struct purgatory_info *pi = &image->purgatory_info;
1106         const Elf_Sym *sym;
1107         Elf_Shdr *sec;
1108         char *sym_buf;
1109
1110         sym = kexec_purgatory_find_symbol(pi, name);
1111         if (!sym)
1112                 return -EINVAL;
1113
1114         if (sym->st_size != size) {
1115                 pr_err("symbol %s size mismatch: expected %lu actual %u\n",
1116                        name, (unsigned long)sym->st_size, size);
1117                 return -EINVAL;
1118         }
1119
1120         sec = pi->sechdrs + sym->st_shndx;
1121
1122         if (sec->sh_type == SHT_NOBITS) {
1123                 pr_err("symbol %s is in a bss section. Cannot %s\n", name,
1124                        get_value ? "get" : "set");
1125                 return -EINVAL;
1126         }
1127
1128         sym_buf = (char *)pi->purgatory_buf + sec->sh_offset + sym->st_value;
1129
1130         if (get_value)
1131                 memcpy((void *)buf, sym_buf, size);
1132         else
1133                 memcpy((void *)sym_buf, buf, size);
1134
1135         return 0;
1136 }
1137 #endif /* CONFIG_ARCH_HAS_KEXEC_PURGATORY */
1138
1139 int crash_exclude_mem_range(struct crash_mem *mem,
1140                             unsigned long long mstart, unsigned long long mend)
1141 {
1142         int i, j;
1143         unsigned long long start, end, p_start, p_end;
1144         struct crash_mem_range temp_range = {0, 0};
1145
1146         for (i = 0; i < mem->nr_ranges; i++) {
1147                 start = mem->ranges[i].start;
1148                 end = mem->ranges[i].end;
1149                 p_start = mstart;
1150                 p_end = mend;
1151
1152                 if (mstart > end || mend < start)
1153                         continue;
1154
1155                 /* Truncate any area outside of range */
1156                 if (mstart < start)
1157                         p_start = start;
1158                 if (mend > end)
1159                         p_end = end;
1160
1161                 /* Found completely overlapping range */
1162                 if (p_start == start && p_end == end) {
1163                         mem->ranges[i].start = 0;
1164                         mem->ranges[i].end = 0;
1165                         if (i < mem->nr_ranges - 1) {
1166                                 /* Shift rest of the ranges to left */
1167                                 for (j = i; j < mem->nr_ranges - 1; j++) {
1168                                         mem->ranges[j].start =
1169                                                 mem->ranges[j+1].start;
1170                                         mem->ranges[j].end =
1171                                                         mem->ranges[j+1].end;
1172                                 }
1173
1174                                 /*
1175                                  * Continue to check if there are another overlapping ranges
1176                                  * from the current position because of shifting the above
1177                                  * mem ranges.
1178                                  */
1179                                 i--;
1180                                 mem->nr_ranges--;
1181                                 continue;
1182                         }
1183                         mem->nr_ranges--;
1184                         return 0;
1185                 }
1186
1187                 if (p_start > start && p_end < end) {
1188                         /* Split original range */
1189                         mem->ranges[i].end = p_start - 1;
1190                         temp_range.start = p_end + 1;
1191                         temp_range.end = end;
1192                 } else if (p_start != start)
1193                         mem->ranges[i].end = p_start - 1;
1194                 else
1195                         mem->ranges[i].start = p_end + 1;
1196                 break;
1197         }
1198
1199         /* If a split happened, add the split to array */
1200         if (!temp_range.end)
1201                 return 0;
1202
1203         /* Split happened */
1204         if (i == mem->max_nr_ranges - 1)
1205                 return -ENOMEM;
1206
1207         /* Location where new range should go */
1208         j = i + 1;
1209         if (j < mem->nr_ranges) {
1210                 /* Move over all ranges one slot towards the end */
1211                 for (i = mem->nr_ranges - 1; i >= j; i--)
1212                         mem->ranges[i + 1] = mem->ranges[i];
1213         }
1214
1215         mem->ranges[j].start = temp_range.start;
1216         mem->ranges[j].end = temp_range.end;
1217         mem->nr_ranges++;
1218         return 0;
1219 }
1220
1221 int crash_prepare_elf64_headers(struct crash_mem *mem, int need_kernel_map,
1222                           void **addr, unsigned long *sz)
1223 {
1224         Elf64_Ehdr *ehdr;
1225         Elf64_Phdr *phdr;
1226         unsigned long nr_cpus = num_possible_cpus(), nr_phdr, elf_sz;
1227         unsigned char *buf;
1228         unsigned int cpu, i;
1229         unsigned long long notes_addr;
1230         unsigned long mstart, mend;
1231
1232         /* extra phdr for vmcoreinfo ELF note */
1233         nr_phdr = nr_cpus + 1;
1234         nr_phdr += mem->nr_ranges;
1235
1236         /*
1237          * kexec-tools creates an extra PT_LOAD phdr for kernel text mapping
1238          * area (for example, ffffffff80000000 - ffffffffa0000000 on x86_64).
1239          * I think this is required by tools like gdb. So same physical
1240          * memory will be mapped in two ELF headers. One will contain kernel
1241          * text virtual addresses and other will have __va(physical) addresses.
1242          */
1243
1244         nr_phdr++;
1245         elf_sz = sizeof(Elf64_Ehdr) + nr_phdr * sizeof(Elf64_Phdr);
1246         elf_sz = ALIGN(elf_sz, ELF_CORE_HEADER_ALIGN);
1247
1248         buf = vzalloc(elf_sz);
1249         if (!buf)
1250                 return -ENOMEM;
1251
1252         ehdr = (Elf64_Ehdr *)buf;
1253         phdr = (Elf64_Phdr *)(ehdr + 1);
1254         memcpy(ehdr->e_ident, ELFMAG, SELFMAG);
1255         ehdr->e_ident[EI_CLASS] = ELFCLASS64;
1256         ehdr->e_ident[EI_DATA] = ELFDATA2LSB;
1257         ehdr->e_ident[EI_VERSION] = EV_CURRENT;
1258         ehdr->e_ident[EI_OSABI] = ELF_OSABI;
1259         memset(ehdr->e_ident + EI_PAD, 0, EI_NIDENT - EI_PAD);
1260         ehdr->e_type = ET_CORE;
1261         ehdr->e_machine = ELF_ARCH;
1262         ehdr->e_version = EV_CURRENT;
1263         ehdr->e_phoff = sizeof(Elf64_Ehdr);
1264         ehdr->e_ehsize = sizeof(Elf64_Ehdr);
1265         ehdr->e_phentsize = sizeof(Elf64_Phdr);
1266
1267         /* Prepare one phdr of type PT_NOTE for each present CPU */
1268         for_each_present_cpu(cpu) {
1269                 phdr->p_type = PT_NOTE;
1270                 notes_addr = per_cpu_ptr_to_phys(per_cpu_ptr(crash_notes, cpu));
1271                 phdr->p_offset = phdr->p_paddr = notes_addr;
1272                 phdr->p_filesz = phdr->p_memsz = sizeof(note_buf_t);
1273                 (ehdr->e_phnum)++;
1274                 phdr++;
1275         }
1276
1277         /* Prepare one PT_NOTE header for vmcoreinfo */
1278         phdr->p_type = PT_NOTE;
1279         phdr->p_offset = phdr->p_paddr = paddr_vmcoreinfo_note();
1280         phdr->p_filesz = phdr->p_memsz = VMCOREINFO_NOTE_SIZE;
1281         (ehdr->e_phnum)++;
1282         phdr++;
1283
1284         /* Prepare PT_LOAD type program header for kernel text region */
1285         if (need_kernel_map) {
1286                 phdr->p_type = PT_LOAD;
1287                 phdr->p_flags = PF_R|PF_W|PF_X;
1288                 phdr->p_vaddr = (unsigned long) _text;
1289                 phdr->p_filesz = phdr->p_memsz = _end - _text;
1290                 phdr->p_offset = phdr->p_paddr = __pa_symbol(_text);
1291                 ehdr->e_phnum++;
1292                 phdr++;
1293         }
1294
1295         /* Go through all the ranges in mem->ranges[] and prepare phdr */
1296         for (i = 0; i < mem->nr_ranges; i++) {
1297                 mstart = mem->ranges[i].start;
1298                 mend = mem->ranges[i].end;
1299
1300                 phdr->p_type = PT_LOAD;
1301                 phdr->p_flags = PF_R|PF_W|PF_X;
1302                 phdr->p_offset  = mstart;
1303
1304                 phdr->p_paddr = mstart;
1305                 phdr->p_vaddr = (unsigned long) __va(mstart);
1306                 phdr->p_filesz = phdr->p_memsz = mend - mstart + 1;
1307                 phdr->p_align = 0;
1308                 ehdr->e_phnum++;
1309                 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",
1310                         phdr, phdr->p_vaddr, phdr->p_paddr, phdr->p_filesz,
1311                         ehdr->e_phnum, phdr->p_offset);
1312                 phdr++;
1313         }
1314
1315         *addr = buf;
1316         *sz = elf_sz;
1317         return 0;
1318 }