Linux 5.2-rc4
[sfrench/cifs-2.6.git] / kernel / kexec_file.c
1 /*
2  * kexec: kexec_file_load system call
3  *
4  * Copyright (C) 2014 Red Hat Inc.
5  * Authors:
6  *      Vivek Goyal <vgoyal@redhat.com>
7  *
8  * This source code is licensed under the GNU General Public License,
9  * Version 2.  See the file COPYING for more details.
10  */
11
12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13
14 #include <linux/capability.h>
15 #include <linux/mm.h>
16 #include <linux/file.h>
17 #include <linux/slab.h>
18 #include <linux/kexec.h>
19 #include <linux/memblock.h>
20 #include <linux/mutex.h>
21 #include <linux/list.h>
22 #include <linux/fs.h>
23 #include <linux/ima.h>
24 #include <crypto/hash.h>
25 #include <crypto/sha.h>
26 #include <linux/elf.h>
27 #include <linux/elfcore.h>
28 #include <linux/kernel.h>
29 #include <linux/syscalls.h>
30 #include <linux/vmalloc.h>
31 #include "kexec_internal.h"
32
33 static int kexec_calculate_store_digests(struct kimage *image);
34
35 /*
36  * Currently this is the only default function that is exported as some
37  * architectures need it to do additional handlings.
38  * In the future, other default functions may be exported too if required.
39  */
40 int kexec_image_probe_default(struct kimage *image, void *buf,
41                               unsigned long buf_len)
42 {
43         const struct kexec_file_ops * const *fops;
44         int ret = -ENOEXEC;
45
46         for (fops = &kexec_file_loaders[0]; *fops && (*fops)->probe; ++fops) {
47                 ret = (*fops)->probe(buf, buf_len);
48                 if (!ret) {
49                         image->fops = *fops;
50                         return ret;
51                 }
52         }
53
54         return ret;
55 }
56
57 /* Architectures can provide this probe function */
58 int __weak arch_kexec_kernel_image_probe(struct kimage *image, void *buf,
59                                          unsigned long buf_len)
60 {
61         return kexec_image_probe_default(image, buf, buf_len);
62 }
63
64 static void *kexec_image_load_default(struct kimage *image)
65 {
66         if (!image->fops || !image->fops->load)
67                 return ERR_PTR(-ENOEXEC);
68
69         return image->fops->load(image, image->kernel_buf,
70                                  image->kernel_buf_len, image->initrd_buf,
71                                  image->initrd_buf_len, image->cmdline_buf,
72                                  image->cmdline_buf_len);
73 }
74
75 void * __weak arch_kexec_kernel_image_load(struct kimage *image)
76 {
77         return kexec_image_load_default(image);
78 }
79
80 int kexec_image_post_load_cleanup_default(struct kimage *image)
81 {
82         if (!image->fops || !image->fops->cleanup)
83                 return 0;
84
85         return image->fops->cleanup(image->image_loader_data);
86 }
87
88 int __weak arch_kimage_file_post_load_cleanup(struct kimage *image)
89 {
90         return kexec_image_post_load_cleanup_default(image);
91 }
92
93 #ifdef CONFIG_KEXEC_VERIFY_SIG
94 static int kexec_image_verify_sig_default(struct kimage *image, void *buf,
95                                           unsigned long buf_len)
96 {
97         if (!image->fops || !image->fops->verify_sig) {
98                 pr_debug("kernel loader does not support signature verification.\n");
99                 return -EKEYREJECTED;
100         }
101
102         return image->fops->verify_sig(buf, buf_len);
103 }
104
105 int __weak arch_kexec_kernel_verify_sig(struct kimage *image, void *buf,
106                                         unsigned long buf_len)
107 {
108         return kexec_image_verify_sig_default(image, buf, buf_len);
109 }
110 #endif
111
112 /*
113  * arch_kexec_apply_relocations_add - apply relocations of type RELA
114  * @pi:         Purgatory to be relocated.
115  * @section:    Section relocations applying to.
116  * @relsec:     Section containing RELAs.
117  * @symtab:     Corresponding symtab.
118  *
119  * Return: 0 on success, negative errno on error.
120  */
121 int __weak
122 arch_kexec_apply_relocations_add(struct purgatory_info *pi, Elf_Shdr *section,
123                                  const Elf_Shdr *relsec, const Elf_Shdr *symtab)
124 {
125         pr_err("RELA relocation unsupported.\n");
126         return -ENOEXEC;
127 }
128
129 /*
130  * arch_kexec_apply_relocations - apply relocations of type REL
131  * @pi:         Purgatory to be relocated.
132  * @section:    Section relocations applying to.
133  * @relsec:     Section containing RELs.
134  * @symtab:     Corresponding symtab.
135  *
136  * Return: 0 on success, negative errno on error.
137  */
138 int __weak
139 arch_kexec_apply_relocations(struct purgatory_info *pi, Elf_Shdr *section,
140                              const Elf_Shdr *relsec, const Elf_Shdr *symtab)
141 {
142         pr_err("REL relocation unsupported.\n");
143         return -ENOEXEC;
144 }
145
146 /*
147  * Free up memory used by kernel, initrd, and command line. This is temporary
148  * memory allocation which is not needed any more after these buffers have
149  * been loaded into separate segments and have been copied elsewhere.
150  */
151 void kimage_file_post_load_cleanup(struct kimage *image)
152 {
153         struct purgatory_info *pi = &image->purgatory_info;
154
155         vfree(image->kernel_buf);
156         image->kernel_buf = NULL;
157
158         vfree(image->initrd_buf);
159         image->initrd_buf = NULL;
160
161         kfree(image->cmdline_buf);
162         image->cmdline_buf = NULL;
163
164         vfree(pi->purgatory_buf);
165         pi->purgatory_buf = NULL;
166
167         vfree(pi->sechdrs);
168         pi->sechdrs = NULL;
169
170         /* See if architecture has anything to cleanup post load */
171         arch_kimage_file_post_load_cleanup(image);
172
173         /*
174          * Above call should have called into bootloader to free up
175          * any data stored in kimage->image_loader_data. It should
176          * be ok now to free it up.
177          */
178         kfree(image->image_loader_data);
179         image->image_loader_data = NULL;
180 }
181
182 /*
183  * In file mode list of segments is prepared by kernel. Copy relevant
184  * data from user space, do error checking, prepare segment list
185  */
186 static int
187 kimage_file_prepare_segments(struct kimage *image, int kernel_fd, int initrd_fd,
188                              const char __user *cmdline_ptr,
189                              unsigned long cmdline_len, unsigned flags)
190 {
191         int ret = 0;
192         void *ldata;
193         loff_t size;
194
195         ret = kernel_read_file_from_fd(kernel_fd, &image->kernel_buf,
196                                        &size, INT_MAX, READING_KEXEC_IMAGE);
197         if (ret)
198                 return ret;
199         image->kernel_buf_len = size;
200
201         /* IMA needs to pass the measurement list to the next kernel. */
202         ima_add_kexec_buffer(image);
203
204         /* Call arch image probe handlers */
205         ret = arch_kexec_kernel_image_probe(image, image->kernel_buf,
206                                             image->kernel_buf_len);
207         if (ret)
208                 goto out;
209
210 #ifdef CONFIG_KEXEC_VERIFY_SIG
211         ret = arch_kexec_kernel_verify_sig(image, image->kernel_buf,
212                                            image->kernel_buf_len);
213         if (ret) {
214                 pr_debug("kernel signature verification failed.\n");
215                 goto out;
216         }
217         pr_debug("kernel signature verification successful.\n");
218 #endif
219         /* It is possible that there no initramfs is being loaded */
220         if (!(flags & KEXEC_FILE_NO_INITRAMFS)) {
221                 ret = kernel_read_file_from_fd(initrd_fd, &image->initrd_buf,
222                                                &size, INT_MAX,
223                                                READING_KEXEC_INITRAMFS);
224                 if (ret)
225                         goto out;
226                 image->initrd_buf_len = size;
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
246         /* Call arch image load handlers */
247         ldata = arch_kexec_kernel_image_load(image);
248
249         if (IS_ERR(ldata)) {
250                 ret = PTR_ERR(ldata);
251                 goto out;
252         }
253
254         image->image_loader_data = ldata;
255 out:
256         /* In case of error, free up all allocated memory in this function */
257         if (ret)
258                 kimage_file_post_load_cleanup(image);
259         return ret;
260 }
261
262 static int
263 kimage_file_alloc_init(struct kimage **rimage, int kernel_fd,
264                        int initrd_fd, const char __user *cmdline_ptr,
265                        unsigned long cmdline_len, unsigned long flags)
266 {
267         int ret;
268         struct kimage *image;
269         bool kexec_on_panic = flags & KEXEC_FILE_ON_CRASH;
270
271         image = do_kimage_alloc_init();
272         if (!image)
273                 return -ENOMEM;
274
275         image->file_mode = 1;
276
277         if (kexec_on_panic) {
278                 /* Enable special crash kernel control page alloc policy. */
279                 image->control_page = crashk_res.start;
280                 image->type = KEXEC_TYPE_CRASH;
281         }
282
283         ret = kimage_file_prepare_segments(image, kernel_fd, initrd_fd,
284                                            cmdline_ptr, cmdline_len, flags);
285         if (ret)
286                 goto out_free_image;
287
288         ret = sanity_check_segment_list(image);
289         if (ret)
290                 goto out_free_post_load_bufs;
291
292         ret = -ENOMEM;
293         image->control_code_page = kimage_alloc_control_pages(image,
294                                            get_order(KEXEC_CONTROL_PAGE_SIZE));
295         if (!image->control_code_page) {
296                 pr_err("Could not allocate control_code_buffer\n");
297                 goto out_free_post_load_bufs;
298         }
299
300         if (!kexec_on_panic) {
301                 image->swap_page = kimage_alloc_control_pages(image, 0);
302                 if (!image->swap_page) {
303                         pr_err("Could not allocate swap buffer\n");
304                         goto out_free_control_pages;
305                 }
306         }
307
308         *rimage = image;
309         return 0;
310 out_free_control_pages:
311         kimage_free_page_list(&image->control_pages);
312 out_free_post_load_bufs:
313         kimage_file_post_load_cleanup(image);
314 out_free_image:
315         kfree(image);
316         return ret;
317 }
318
319 SYSCALL_DEFINE5(kexec_file_load, int, kernel_fd, int, initrd_fd,
320                 unsigned long, cmdline_len, const char __user *, cmdline_ptr,
321                 unsigned long, flags)
322 {
323         int ret = 0, i;
324         struct kimage **dest_image, *image;
325
326         /* We only trust the superuser with rebooting the system. */
327         if (!capable(CAP_SYS_BOOT) || kexec_load_disabled)
328                 return -EPERM;
329
330         /* Make sure we have a legal set of flags */
331         if (flags != (flags & KEXEC_FILE_FLAGS))
332                 return -EINVAL;
333
334         image = NULL;
335
336         if (!mutex_trylock(&kexec_mutex))
337                 return -EBUSY;
338
339         dest_image = &kexec_image;
340         if (flags & KEXEC_FILE_ON_CRASH) {
341                 dest_image = &kexec_crash_image;
342                 if (kexec_crash_image)
343                         arch_kexec_unprotect_crashkres();
344         }
345
346         if (flags & KEXEC_FILE_UNLOAD)
347                 goto exchange;
348
349         /*
350          * In case of crash, new kernel gets loaded in reserved region. It is
351          * same memory where old crash kernel might be loaded. Free any
352          * current crash dump kernel before we corrupt it.
353          */
354         if (flags & KEXEC_FILE_ON_CRASH)
355                 kimage_free(xchg(&kexec_crash_image, NULL));
356
357         ret = kimage_file_alloc_init(&image, kernel_fd, initrd_fd, cmdline_ptr,
358                                      cmdline_len, flags);
359         if (ret)
360                 goto out;
361
362         ret = machine_kexec_prepare(image);
363         if (ret)
364                 goto out;
365
366         /*
367          * Some architecture(like S390) may touch the crash memory before
368          * machine_kexec_prepare(), we must copy vmcoreinfo data after it.
369          */
370         ret = kimage_crash_copy_vmcoreinfo(image);
371         if (ret)
372                 goto out;
373
374         ret = kexec_calculate_store_digests(image);
375         if (ret)
376                 goto out;
377
378         for (i = 0; i < image->nr_segments; i++) {
379                 struct kexec_segment *ksegment;
380
381                 ksegment = &image->segment[i];
382                 pr_debug("Loading segment %d: buf=0x%p bufsz=0x%zx mem=0x%lx memsz=0x%zx\n",
383                          i, ksegment->buf, ksegment->bufsz, ksegment->mem,
384                          ksegment->memsz);
385
386                 ret = kimage_load_segment(image, &image->segment[i]);
387                 if (ret)
388                         goto out;
389         }
390
391         kimage_terminate(image);
392
393         /*
394          * Free up any temporary buffers allocated which are not needed
395          * after image has been loaded
396          */
397         kimage_file_post_load_cleanup(image);
398 exchange:
399         image = xchg(dest_image, image);
400 out:
401         if ((flags & KEXEC_FILE_ON_CRASH) && kexec_crash_image)
402                 arch_kexec_protect_crashkres();
403
404         mutex_unlock(&kexec_mutex);
405         kimage_free(image);
406         return ret;
407 }
408
409 static int locate_mem_hole_top_down(unsigned long start, unsigned long end,
410                                     struct kexec_buf *kbuf)
411 {
412         struct kimage *image = kbuf->image;
413         unsigned long temp_start, temp_end;
414
415         temp_end = min(end, kbuf->buf_max);
416         temp_start = temp_end - kbuf->memsz;
417
418         do {
419                 /* align down start */
420                 temp_start = temp_start & (~(kbuf->buf_align - 1));
421
422                 if (temp_start < start || temp_start < kbuf->buf_min)
423                         return 0;
424
425                 temp_end = temp_start + kbuf->memsz - 1;
426
427                 /*
428                  * Make sure this does not conflict with any of existing
429                  * segments
430                  */
431                 if (kimage_is_destination_range(image, temp_start, temp_end)) {
432                         temp_start = temp_start - PAGE_SIZE;
433                         continue;
434                 }
435
436                 /* We found a suitable memory range */
437                 break;
438         } while (1);
439
440         /* If we are here, we found a suitable memory range */
441         kbuf->mem = temp_start;
442
443         /* Success, stop navigating through remaining System RAM ranges */
444         return 1;
445 }
446
447 static int locate_mem_hole_bottom_up(unsigned long start, unsigned long end,
448                                      struct kexec_buf *kbuf)
449 {
450         struct kimage *image = kbuf->image;
451         unsigned long temp_start, temp_end;
452
453         temp_start = max(start, kbuf->buf_min);
454
455         do {
456                 temp_start = ALIGN(temp_start, kbuf->buf_align);
457                 temp_end = temp_start + kbuf->memsz - 1;
458
459                 if (temp_end > end || temp_end > kbuf->buf_max)
460                         return 0;
461                 /*
462                  * Make sure this does not conflict with any of existing
463                  * segments
464                  */
465                 if (kimage_is_destination_range(image, temp_start, temp_end)) {
466                         temp_start = temp_start + PAGE_SIZE;
467                         continue;
468                 }
469
470                 /* We found a suitable memory range */
471                 break;
472         } while (1);
473
474         /* If we are here, we found a suitable memory range */
475         kbuf->mem = temp_start;
476
477         /* Success, stop navigating through remaining System RAM ranges */
478         return 1;
479 }
480
481 static int locate_mem_hole_callback(struct resource *res, void *arg)
482 {
483         struct kexec_buf *kbuf = (struct kexec_buf *)arg;
484         u64 start = res->start, end = res->end;
485         unsigned long sz = end - start + 1;
486
487         /* Returning 0 will take to next memory range */
488         if (sz < kbuf->memsz)
489                 return 0;
490
491         if (end < kbuf->buf_min || start > kbuf->buf_max)
492                 return 0;
493
494         /*
495          * Allocate memory top down with-in ram range. Otherwise bottom up
496          * allocation.
497          */
498         if (kbuf->top_down)
499                 return locate_mem_hole_top_down(start, end, kbuf);
500         return locate_mem_hole_bottom_up(start, end, kbuf);
501 }
502
503 #ifdef CONFIG_ARCH_DISCARD_MEMBLOCK
504 static int kexec_walk_memblock(struct kexec_buf *kbuf,
505                                int (*func)(struct resource *, void *))
506 {
507         return 0;
508 }
509 #else
510 static int kexec_walk_memblock(struct kexec_buf *kbuf,
511                                int (*func)(struct resource *, void *))
512 {
513         int ret = 0;
514         u64 i;
515         phys_addr_t mstart, mend;
516         struct resource res = { };
517
518         if (kbuf->image->type == KEXEC_TYPE_CRASH)
519                 return func(&crashk_res, kbuf);
520
521         if (kbuf->top_down) {
522                 for_each_free_mem_range_reverse(i, NUMA_NO_NODE, MEMBLOCK_NONE,
523                                                 &mstart, &mend, NULL) {
524                         /*
525                          * In memblock, end points to the first byte after the
526                          * range while in kexec, end points to the last byte
527                          * in the range.
528                          */
529                         res.start = mstart;
530                         res.end = mend - 1;
531                         ret = func(&res, kbuf);
532                         if (ret)
533                                 break;
534                 }
535         } else {
536                 for_each_free_mem_range(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         }
550
551         return ret;
552 }
553 #endif
554
555 /**
556  * kexec_walk_resources - call func(data) on free memory regions
557  * @kbuf:       Context info for the search. Also passed to @func.
558  * @func:       Function to call for each memory region.
559  *
560  * Return: The memory walk will stop when func returns a non-zero value
561  * and that value will be returned. If all free regions are visited without
562  * func returning non-zero, then zero will be returned.
563  */
564 static int kexec_walk_resources(struct kexec_buf *kbuf,
565                                 int (*func)(struct resource *, void *))
566 {
567         if (kbuf->image->type == KEXEC_TYPE_CRASH)
568                 return walk_iomem_res_desc(crashk_res.desc,
569                                            IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY,
570                                            crashk_res.start, crashk_res.end,
571                                            kbuf, func);
572         else
573                 return walk_system_ram_res(0, ULONG_MAX, kbuf, func);
574 }
575
576 /**
577  * kexec_locate_mem_hole - find free memory for the purgatory or the next kernel
578  * @kbuf:       Parameters for the memory search.
579  *
580  * On success, kbuf->mem will have the start address of the memory region found.
581  *
582  * Return: 0 on success, negative errno on error.
583  */
584 int kexec_locate_mem_hole(struct kexec_buf *kbuf)
585 {
586         int ret;
587
588         /* Arch knows where to place */
589         if (kbuf->mem != KEXEC_BUF_MEM_UNKNOWN)
590                 return 0;
591
592         if (IS_ENABLED(CONFIG_ARCH_DISCARD_MEMBLOCK))
593                 ret = kexec_walk_resources(kbuf, locate_mem_hole_callback);
594         else
595                 ret = kexec_walk_memblock(kbuf, locate_mem_hole_callback);
596
597         return ret == 1 ? 0 : -EADDRNOTAVAIL;
598 }
599
600 /**
601  * kexec_add_buffer - place a buffer in a kexec segment
602  * @kbuf:       Buffer contents and memory parameters.
603  *
604  * This function assumes that kexec_mutex is held.
605  * On successful return, @kbuf->mem will have the physical address of
606  * the buffer in memory.
607  *
608  * Return: 0 on success, negative errno on error.
609  */
610 int kexec_add_buffer(struct kexec_buf *kbuf)
611 {
612
613         struct kexec_segment *ksegment;
614         int ret;
615
616         /* Currently adding segment this way is allowed only in file mode */
617         if (!kbuf->image->file_mode)
618                 return -EINVAL;
619
620         if (kbuf->image->nr_segments >= KEXEC_SEGMENT_MAX)
621                 return -EINVAL;
622
623         /*
624          * Make sure we are not trying to add buffer after allocating
625          * control pages. All segments need to be placed first before
626          * any control pages are allocated. As control page allocation
627          * logic goes through list of segments to make sure there are
628          * no destination overlaps.
629          */
630         if (!list_empty(&kbuf->image->control_pages)) {
631                 WARN_ON(1);
632                 return -EINVAL;
633         }
634
635         /* Ensure minimum alignment needed for segments. */
636         kbuf->memsz = ALIGN(kbuf->memsz, PAGE_SIZE);
637         kbuf->buf_align = max(kbuf->buf_align, PAGE_SIZE);
638
639         /* Walk the RAM ranges and allocate a suitable range for the buffer */
640         ret = kexec_locate_mem_hole(kbuf);
641         if (ret)
642                 return ret;
643
644         /* Found a suitable memory range */
645         ksegment = &kbuf->image->segment[kbuf->image->nr_segments];
646         ksegment->kbuf = kbuf->buffer;
647         ksegment->bufsz = kbuf->bufsz;
648         ksegment->mem = kbuf->mem;
649         ksegment->memsz = kbuf->memsz;
650         kbuf->image->nr_segments++;
651         return 0;
652 }
653
654 /* Calculate and store the digest of segments */
655 static int kexec_calculate_store_digests(struct kimage *image)
656 {
657         struct crypto_shash *tfm;
658         struct shash_desc *desc;
659         int ret = 0, i, j, zero_buf_sz, sha_region_sz;
660         size_t desc_size, nullsz;
661         char *digest;
662         void *zero_buf;
663         struct kexec_sha_region *sha_regions;
664         struct purgatory_info *pi = &image->purgatory_info;
665
666         if (!IS_ENABLED(CONFIG_ARCH_HAS_KEXEC_PURGATORY))
667                 return 0;
668
669         zero_buf = __va(page_to_pfn(ZERO_PAGE(0)) << PAGE_SHIFT);
670         zero_buf_sz = PAGE_SIZE;
671
672         tfm = crypto_alloc_shash("sha256", 0, 0);
673         if (IS_ERR(tfm)) {
674                 ret = PTR_ERR(tfm);
675                 goto out;
676         }
677
678         desc_size = crypto_shash_descsize(tfm) + sizeof(*desc);
679         desc = kzalloc(desc_size, GFP_KERNEL);
680         if (!desc) {
681                 ret = -ENOMEM;
682                 goto out_free_tfm;
683         }
684
685         sha_region_sz = KEXEC_SEGMENT_MAX * sizeof(struct kexec_sha_region);
686         sha_regions = vzalloc(sha_region_sz);
687         if (!sha_regions)
688                 goto out_free_desc;
689
690         desc->tfm   = tfm;
691         desc->flags = 0;
692
693         ret = crypto_shash_init(desc);
694         if (ret < 0)
695                 goto out_free_sha_regions;
696
697         digest = kzalloc(SHA256_DIGEST_SIZE, GFP_KERNEL);
698         if (!digest) {
699                 ret = -ENOMEM;
700                 goto out_free_sha_regions;
701         }
702
703         for (j = i = 0; i < image->nr_segments; i++) {
704                 struct kexec_segment *ksegment;
705
706                 ksegment = &image->segment[i];
707                 /*
708                  * Skip purgatory as it will be modified once we put digest
709                  * info in purgatory.
710                  */
711                 if (ksegment->kbuf == pi->purgatory_buf)
712                         continue;
713
714                 ret = crypto_shash_update(desc, ksegment->kbuf,
715                                           ksegment->bufsz);
716                 if (ret)
717                         break;
718
719                 /*
720                  * Assume rest of the buffer is filled with zero and
721                  * update digest accordingly.
722                  */
723                 nullsz = ksegment->memsz - ksegment->bufsz;
724                 while (nullsz) {
725                         unsigned long bytes = nullsz;
726
727                         if (bytes > zero_buf_sz)
728                                 bytes = zero_buf_sz;
729                         ret = crypto_shash_update(desc, zero_buf, bytes);
730                         if (ret)
731                                 break;
732                         nullsz -= bytes;
733                 }
734
735                 if (ret)
736                         break;
737
738                 sha_regions[j].start = ksegment->mem;
739                 sha_regions[j].len = ksegment->memsz;
740                 j++;
741         }
742
743         if (!ret) {
744                 ret = crypto_shash_final(desc, digest);
745                 if (ret)
746                         goto out_free_digest;
747                 ret = kexec_purgatory_get_set_symbol(image, "purgatory_sha_regions",
748                                                      sha_regions, sha_region_sz, 0);
749                 if (ret)
750                         goto out_free_digest;
751
752                 ret = kexec_purgatory_get_set_symbol(image, "purgatory_sha256_digest",
753                                                      digest, SHA256_DIGEST_SIZE, 0);
754                 if (ret)
755                         goto out_free_digest;
756         }
757
758 out_free_digest:
759         kfree(digest);
760 out_free_sha_regions:
761         vfree(sha_regions);
762 out_free_desc:
763         kfree(desc);
764 out_free_tfm:
765         kfree(tfm);
766 out:
767         return ret;
768 }
769
770 #ifdef CONFIG_ARCH_HAS_KEXEC_PURGATORY
771 /*
772  * kexec_purgatory_setup_kbuf - prepare buffer to load purgatory.
773  * @pi:         Purgatory to be loaded.
774  * @kbuf:       Buffer to setup.
775  *
776  * Allocates the memory needed for the buffer. Caller is responsible to free
777  * the memory after use.
778  *
779  * Return: 0 on success, negative errno on error.
780  */
781 static int kexec_purgatory_setup_kbuf(struct purgatory_info *pi,
782                                       struct kexec_buf *kbuf)
783 {
784         const Elf_Shdr *sechdrs;
785         unsigned long bss_align;
786         unsigned long bss_sz;
787         unsigned long align;
788         int i, ret;
789
790         sechdrs = (void *)pi->ehdr + pi->ehdr->e_shoff;
791         kbuf->buf_align = bss_align = 1;
792         kbuf->bufsz = bss_sz = 0;
793
794         for (i = 0; i < pi->ehdr->e_shnum; i++) {
795                 if (!(sechdrs[i].sh_flags & SHF_ALLOC))
796                         continue;
797
798                 align = sechdrs[i].sh_addralign;
799                 if (sechdrs[i].sh_type != SHT_NOBITS) {
800                         if (kbuf->buf_align < align)
801                                 kbuf->buf_align = align;
802                         kbuf->bufsz = ALIGN(kbuf->bufsz, align);
803                         kbuf->bufsz += sechdrs[i].sh_size;
804                 } else {
805                         if (bss_align < align)
806                                 bss_align = align;
807                         bss_sz = ALIGN(bss_sz, align);
808                         bss_sz += sechdrs[i].sh_size;
809                 }
810         }
811         kbuf->bufsz = ALIGN(kbuf->bufsz, bss_align);
812         kbuf->memsz = kbuf->bufsz + bss_sz;
813         if (kbuf->buf_align < bss_align)
814                 kbuf->buf_align = bss_align;
815
816         kbuf->buffer = vzalloc(kbuf->bufsz);
817         if (!kbuf->buffer)
818                 return -ENOMEM;
819         pi->purgatory_buf = kbuf->buffer;
820
821         ret = kexec_add_buffer(kbuf);
822         if (ret)
823                 goto out;
824
825         return 0;
826 out:
827         vfree(pi->purgatory_buf);
828         pi->purgatory_buf = NULL;
829         return ret;
830 }
831
832 /*
833  * kexec_purgatory_setup_sechdrs - prepares the pi->sechdrs buffer.
834  * @pi:         Purgatory to be loaded.
835  * @kbuf:       Buffer prepared to store purgatory.
836  *
837  * Allocates the memory needed for the buffer. Caller is responsible to free
838  * the memory after use.
839  *
840  * Return: 0 on success, negative errno on error.
841  */
842 static int kexec_purgatory_setup_sechdrs(struct purgatory_info *pi,
843                                          struct kexec_buf *kbuf)
844 {
845         unsigned long bss_addr;
846         unsigned long offset;
847         Elf_Shdr *sechdrs;
848         int i;
849
850         /*
851          * The section headers in kexec_purgatory are read-only. In order to
852          * have them modifiable make a temporary copy.
853          */
854         sechdrs = vzalloc(array_size(sizeof(Elf_Shdr), pi->ehdr->e_shnum));
855         if (!sechdrs)
856                 return -ENOMEM;
857         memcpy(sechdrs, (void *)pi->ehdr + pi->ehdr->e_shoff,
858                pi->ehdr->e_shnum * sizeof(Elf_Shdr));
859         pi->sechdrs = sechdrs;
860
861         offset = 0;
862         bss_addr = kbuf->mem + kbuf->bufsz;
863         kbuf->image->start = pi->ehdr->e_entry;
864
865         for (i = 0; i < pi->ehdr->e_shnum; i++) {
866                 unsigned long align;
867                 void *src, *dst;
868
869                 if (!(sechdrs[i].sh_flags & SHF_ALLOC))
870                         continue;
871
872                 align = sechdrs[i].sh_addralign;
873                 if (sechdrs[i].sh_type == SHT_NOBITS) {
874                         bss_addr = ALIGN(bss_addr, align);
875                         sechdrs[i].sh_addr = bss_addr;
876                         bss_addr += sechdrs[i].sh_size;
877                         continue;
878                 }
879
880                 offset = ALIGN(offset, align);
881                 if (sechdrs[i].sh_flags & SHF_EXECINSTR &&
882                     pi->ehdr->e_entry >= sechdrs[i].sh_addr &&
883                     pi->ehdr->e_entry < (sechdrs[i].sh_addr
884                                          + sechdrs[i].sh_size)) {
885                         kbuf->image->start -= sechdrs[i].sh_addr;
886                         kbuf->image->start += kbuf->mem + offset;
887                 }
888
889                 src = (void *)pi->ehdr + sechdrs[i].sh_offset;
890                 dst = pi->purgatory_buf + offset;
891                 memcpy(dst, src, sechdrs[i].sh_size);
892
893                 sechdrs[i].sh_addr = kbuf->mem + offset;
894                 sechdrs[i].sh_offset = offset;
895                 offset += sechdrs[i].sh_size;
896         }
897
898         return 0;
899 }
900
901 static int kexec_apply_relocations(struct kimage *image)
902 {
903         int i, ret;
904         struct purgatory_info *pi = &image->purgatory_info;
905         const Elf_Shdr *sechdrs;
906
907         sechdrs = (void *)pi->ehdr + pi->ehdr->e_shoff;
908
909         for (i = 0; i < pi->ehdr->e_shnum; i++) {
910                 const Elf_Shdr *relsec;
911                 const Elf_Shdr *symtab;
912                 Elf_Shdr *section;
913
914                 relsec = sechdrs + i;
915
916                 if (relsec->sh_type != SHT_RELA &&
917                     relsec->sh_type != SHT_REL)
918                         continue;
919
920                 /*
921                  * For section of type SHT_RELA/SHT_REL,
922                  * ->sh_link contains section header index of associated
923                  * symbol table. And ->sh_info contains section header
924                  * index of section to which relocations apply.
925                  */
926                 if (relsec->sh_info >= pi->ehdr->e_shnum ||
927                     relsec->sh_link >= pi->ehdr->e_shnum)
928                         return -ENOEXEC;
929
930                 section = pi->sechdrs + relsec->sh_info;
931                 symtab = sechdrs + relsec->sh_link;
932
933                 if (!(section->sh_flags & SHF_ALLOC))
934                         continue;
935
936                 /*
937                  * symtab->sh_link contain section header index of associated
938                  * string table.
939                  */
940                 if (symtab->sh_link >= pi->ehdr->e_shnum)
941                         /* Invalid section number? */
942                         continue;
943
944                 /*
945                  * Respective architecture needs to provide support for applying
946                  * relocations of type SHT_RELA/SHT_REL.
947                  */
948                 if (relsec->sh_type == SHT_RELA)
949                         ret = arch_kexec_apply_relocations_add(pi, section,
950                                                                relsec, symtab);
951                 else if (relsec->sh_type == SHT_REL)
952                         ret = arch_kexec_apply_relocations(pi, section,
953                                                            relsec, symtab);
954                 if (ret)
955                         return ret;
956         }
957
958         return 0;
959 }
960
961 /*
962  * kexec_load_purgatory - Load and relocate the purgatory object.
963  * @image:      Image to add the purgatory to.
964  * @kbuf:       Memory parameters to use.
965  *
966  * Allocates the memory needed for image->purgatory_info.sechdrs and
967  * image->purgatory_info.purgatory_buf/kbuf->buffer. Caller is responsible
968  * to free the memory after use.
969  *
970  * Return: 0 on success, negative errno on error.
971  */
972 int kexec_load_purgatory(struct kimage *image, struct kexec_buf *kbuf)
973 {
974         struct purgatory_info *pi = &image->purgatory_info;
975         int ret;
976
977         if (kexec_purgatory_size <= 0)
978                 return -EINVAL;
979
980         pi->ehdr = (const Elf_Ehdr *)kexec_purgatory;
981
982         ret = kexec_purgatory_setup_kbuf(pi, kbuf);
983         if (ret)
984                 return ret;
985
986         ret = kexec_purgatory_setup_sechdrs(pi, kbuf);
987         if (ret)
988                 goto out_free_kbuf;
989
990         ret = kexec_apply_relocations(image);
991         if (ret)
992                 goto out;
993
994         return 0;
995 out:
996         vfree(pi->sechdrs);
997         pi->sechdrs = NULL;
998 out_free_kbuf:
999         vfree(pi->purgatory_buf);
1000         pi->purgatory_buf = NULL;
1001         return ret;
1002 }
1003
1004 /*
1005  * kexec_purgatory_find_symbol - find a symbol in the purgatory
1006  * @pi:         Purgatory to search in.
1007  * @name:       Name of the symbol.
1008  *
1009  * Return: pointer to symbol in read-only symtab on success, NULL on error.
1010  */
1011 static const Elf_Sym *kexec_purgatory_find_symbol(struct purgatory_info *pi,
1012                                                   const char *name)
1013 {
1014         const Elf_Shdr *sechdrs;
1015         const Elf_Ehdr *ehdr;
1016         const Elf_Sym *syms;
1017         const char *strtab;
1018         int i, k;
1019
1020         if (!pi->ehdr)
1021                 return NULL;
1022
1023         ehdr = pi->ehdr;
1024         sechdrs = (void *)ehdr + ehdr->e_shoff;
1025
1026         for (i = 0; i < ehdr->e_shnum; i++) {
1027                 if (sechdrs[i].sh_type != SHT_SYMTAB)
1028                         continue;
1029
1030                 if (sechdrs[i].sh_link >= ehdr->e_shnum)
1031                         /* Invalid strtab section number */
1032                         continue;
1033                 strtab = (void *)ehdr + sechdrs[sechdrs[i].sh_link].sh_offset;
1034                 syms = (void *)ehdr + sechdrs[i].sh_offset;
1035
1036                 /* Go through symbols for a match */
1037                 for (k = 0; k < sechdrs[i].sh_size/sizeof(Elf_Sym); k++) {
1038                         if (ELF_ST_BIND(syms[k].st_info) != STB_GLOBAL)
1039                                 continue;
1040
1041                         if (strcmp(strtab + syms[k].st_name, name) != 0)
1042                                 continue;
1043
1044                         if (syms[k].st_shndx == SHN_UNDEF ||
1045                             syms[k].st_shndx >= ehdr->e_shnum) {
1046                                 pr_debug("Symbol: %s has bad section index %d.\n",
1047                                                 name, syms[k].st_shndx);
1048                                 return NULL;
1049                         }
1050
1051                         /* Found the symbol we are looking for */
1052                         return &syms[k];
1053                 }
1054         }
1055
1056         return NULL;
1057 }
1058
1059 void *kexec_purgatory_get_symbol_addr(struct kimage *image, const char *name)
1060 {
1061         struct purgatory_info *pi = &image->purgatory_info;
1062         const Elf_Sym *sym;
1063         Elf_Shdr *sechdr;
1064
1065         sym = kexec_purgatory_find_symbol(pi, name);
1066         if (!sym)
1067                 return ERR_PTR(-EINVAL);
1068
1069         sechdr = &pi->sechdrs[sym->st_shndx];
1070
1071         /*
1072          * Returns the address where symbol will finally be loaded after
1073          * kexec_load_segment()
1074          */
1075         return (void *)(sechdr->sh_addr + sym->st_value);
1076 }
1077
1078 /*
1079  * Get or set value of a symbol. If "get_value" is true, symbol value is
1080  * returned in buf otherwise symbol value is set based on value in buf.
1081  */
1082 int kexec_purgatory_get_set_symbol(struct kimage *image, const char *name,
1083                                    void *buf, unsigned int size, bool get_value)
1084 {
1085         struct purgatory_info *pi = &image->purgatory_info;
1086         const Elf_Sym *sym;
1087         Elf_Shdr *sec;
1088         char *sym_buf;
1089
1090         sym = kexec_purgatory_find_symbol(pi, name);
1091         if (!sym)
1092                 return -EINVAL;
1093
1094         if (sym->st_size != size) {
1095                 pr_err("symbol %s size mismatch: expected %lu actual %u\n",
1096                        name, (unsigned long)sym->st_size, size);
1097                 return -EINVAL;
1098         }
1099
1100         sec = pi->sechdrs + sym->st_shndx;
1101
1102         if (sec->sh_type == SHT_NOBITS) {
1103                 pr_err("symbol %s is in a bss section. Cannot %s\n", name,
1104                        get_value ? "get" : "set");
1105                 return -EINVAL;
1106         }
1107
1108         sym_buf = (char *)pi->purgatory_buf + sec->sh_offset + sym->st_value;
1109
1110         if (get_value)
1111                 memcpy((void *)buf, sym_buf, size);
1112         else
1113                 memcpy((void *)sym_buf, buf, size);
1114
1115         return 0;
1116 }
1117 #endif /* CONFIG_ARCH_HAS_KEXEC_PURGATORY */
1118
1119 int crash_exclude_mem_range(struct crash_mem *mem,
1120                             unsigned long long mstart, unsigned long long mend)
1121 {
1122         int i, j;
1123         unsigned long long start, end;
1124         struct crash_mem_range temp_range = {0, 0};
1125
1126         for (i = 0; i < mem->nr_ranges; i++) {
1127                 start = mem->ranges[i].start;
1128                 end = mem->ranges[i].end;
1129
1130                 if (mstart > end || mend < start)
1131                         continue;
1132
1133                 /* Truncate any area outside of range */
1134                 if (mstart < start)
1135                         mstart = start;
1136                 if (mend > end)
1137                         mend = end;
1138
1139                 /* Found completely overlapping range */
1140                 if (mstart == start && mend == end) {
1141                         mem->ranges[i].start = 0;
1142                         mem->ranges[i].end = 0;
1143                         if (i < mem->nr_ranges - 1) {
1144                                 /* Shift rest of the ranges to left */
1145                                 for (j = i; j < mem->nr_ranges - 1; j++) {
1146                                         mem->ranges[j].start =
1147                                                 mem->ranges[j+1].start;
1148                                         mem->ranges[j].end =
1149                                                         mem->ranges[j+1].end;
1150                                 }
1151                         }
1152                         mem->nr_ranges--;
1153                         return 0;
1154                 }
1155
1156                 if (mstart > start && mend < end) {
1157                         /* Split original range */
1158                         mem->ranges[i].end = mstart - 1;
1159                         temp_range.start = mend + 1;
1160                         temp_range.end = end;
1161                 } else if (mstart != start)
1162                         mem->ranges[i].end = mstart - 1;
1163                 else
1164                         mem->ranges[i].start = mend + 1;
1165                 break;
1166         }
1167
1168         /* If a split happened, add the split to array */
1169         if (!temp_range.end)
1170                 return 0;
1171
1172         /* Split happened */
1173         if (i == mem->max_nr_ranges - 1)
1174                 return -ENOMEM;
1175
1176         /* Location where new range should go */
1177         j = i + 1;
1178         if (j < mem->nr_ranges) {
1179                 /* Move over all ranges one slot towards the end */
1180                 for (i = mem->nr_ranges - 1; i >= j; i--)
1181                         mem->ranges[i + 1] = mem->ranges[i];
1182         }
1183
1184         mem->ranges[j].start = temp_range.start;
1185         mem->ranges[j].end = temp_range.end;
1186         mem->nr_ranges++;
1187         return 0;
1188 }
1189
1190 int crash_prepare_elf64_headers(struct crash_mem *mem, int kernel_map,
1191                           void **addr, unsigned long *sz)
1192 {
1193         Elf64_Ehdr *ehdr;
1194         Elf64_Phdr *phdr;
1195         unsigned long nr_cpus = num_possible_cpus(), nr_phdr, elf_sz;
1196         unsigned char *buf;
1197         unsigned int cpu, i;
1198         unsigned long long notes_addr;
1199         unsigned long mstart, mend;
1200
1201         /* extra phdr for vmcoreinfo elf note */
1202         nr_phdr = nr_cpus + 1;
1203         nr_phdr += mem->nr_ranges;
1204
1205         /*
1206          * kexec-tools creates an extra PT_LOAD phdr for kernel text mapping
1207          * area (for example, ffffffff80000000 - ffffffffa0000000 on x86_64).
1208          * I think this is required by tools like gdb. So same physical
1209          * memory will be mapped in two elf headers. One will contain kernel
1210          * text virtual addresses and other will have __va(physical) addresses.
1211          */
1212
1213         nr_phdr++;
1214         elf_sz = sizeof(Elf64_Ehdr) + nr_phdr * sizeof(Elf64_Phdr);
1215         elf_sz = ALIGN(elf_sz, ELF_CORE_HEADER_ALIGN);
1216
1217         buf = vzalloc(elf_sz);
1218         if (!buf)
1219                 return -ENOMEM;
1220
1221         ehdr = (Elf64_Ehdr *)buf;
1222         phdr = (Elf64_Phdr *)(ehdr + 1);
1223         memcpy(ehdr->e_ident, ELFMAG, SELFMAG);
1224         ehdr->e_ident[EI_CLASS] = ELFCLASS64;
1225         ehdr->e_ident[EI_DATA] = ELFDATA2LSB;
1226         ehdr->e_ident[EI_VERSION] = EV_CURRENT;
1227         ehdr->e_ident[EI_OSABI] = ELF_OSABI;
1228         memset(ehdr->e_ident + EI_PAD, 0, EI_NIDENT - EI_PAD);
1229         ehdr->e_type = ET_CORE;
1230         ehdr->e_machine = ELF_ARCH;
1231         ehdr->e_version = EV_CURRENT;
1232         ehdr->e_phoff = sizeof(Elf64_Ehdr);
1233         ehdr->e_ehsize = sizeof(Elf64_Ehdr);
1234         ehdr->e_phentsize = sizeof(Elf64_Phdr);
1235
1236         /* Prepare one phdr of type PT_NOTE for each present cpu */
1237         for_each_present_cpu(cpu) {
1238                 phdr->p_type = PT_NOTE;
1239                 notes_addr = per_cpu_ptr_to_phys(per_cpu_ptr(crash_notes, cpu));
1240                 phdr->p_offset = phdr->p_paddr = notes_addr;
1241                 phdr->p_filesz = phdr->p_memsz = sizeof(note_buf_t);
1242                 (ehdr->e_phnum)++;
1243                 phdr++;
1244         }
1245
1246         /* Prepare one PT_NOTE header for vmcoreinfo */
1247         phdr->p_type = PT_NOTE;
1248         phdr->p_offset = phdr->p_paddr = paddr_vmcoreinfo_note();
1249         phdr->p_filesz = phdr->p_memsz = VMCOREINFO_NOTE_SIZE;
1250         (ehdr->e_phnum)++;
1251         phdr++;
1252
1253         /* Prepare PT_LOAD type program header for kernel text region */
1254         if (kernel_map) {
1255                 phdr->p_type = PT_LOAD;
1256                 phdr->p_flags = PF_R|PF_W|PF_X;
1257                 phdr->p_vaddr = (Elf64_Addr)_text;
1258                 phdr->p_filesz = phdr->p_memsz = _end - _text;
1259                 phdr->p_offset = phdr->p_paddr = __pa_symbol(_text);
1260                 ehdr->e_phnum++;
1261                 phdr++;
1262         }
1263
1264         /* Go through all the ranges in mem->ranges[] and prepare phdr */
1265         for (i = 0; i < mem->nr_ranges; i++) {
1266                 mstart = mem->ranges[i].start;
1267                 mend = mem->ranges[i].end;
1268
1269                 phdr->p_type = PT_LOAD;
1270                 phdr->p_flags = PF_R|PF_W|PF_X;
1271                 phdr->p_offset  = mstart;
1272
1273                 phdr->p_paddr = mstart;
1274                 phdr->p_vaddr = (unsigned long long) __va(mstart);
1275                 phdr->p_filesz = phdr->p_memsz = mend - mstart + 1;
1276                 phdr->p_align = 0;
1277                 ehdr->e_phnum++;
1278                 phdr++;
1279                 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",
1280                         phdr, phdr->p_vaddr, phdr->p_paddr, phdr->p_filesz,
1281                         ehdr->e_phnum, phdr->p_offset);
1282         }
1283
1284         *addr = buf;
1285         *sz = elf_sz;
1286         return 0;
1287 }