Merge tag 'block-5.17-2022-01-28' of git://git.kernel.dk/linux-block
[linux-2.6-microblaze.git] / kernel / kexec_file.c
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * kexec: kexec_file_load system call
4  *
5  * Copyright (C) 2014 Red Hat Inc.
6  * Authors:
7  *      Vivek Goyal <vgoyal@redhat.com>
8  */
9
10 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11
12 #include <linux/capability.h>
13 #include <linux/mm.h>
14 #include <linux/file.h>
15 #include <linux/slab.h>
16 #include <linux/kexec.h>
17 #include <linux/memblock.h>
18 #include <linux/mutex.h>
19 #include <linux/list.h>
20 #include <linux/fs.h>
21 #include <linux/ima.h>
22 #include <crypto/hash.h>
23 #include <crypto/sha2.h>
24 #include <linux/elf.h>
25 #include <linux/elfcore.h>
26 #include <linux/kernel.h>
27 #include <linux/kernel_read_file.h>
28 #include <linux/syscalls.h>
29 #include <linux/vmalloc.h>
30 #include "kexec_internal.h"
31
32 static int kexec_calculate_store_digests(struct kimage *image);
33
34 /*
35  * Currently this is the only default function that is exported as some
36  * architectures need it to do additional handlings.
37  * In the future, other default functions may be exported too if required.
38  */
39 int kexec_image_probe_default(struct kimage *image, void *buf,
40                               unsigned long buf_len)
41 {
42         const struct kexec_file_ops * const *fops;
43         int ret = -ENOEXEC;
44
45         for (fops = &kexec_file_loaders[0]; *fops && (*fops)->probe; ++fops) {
46                 ret = (*fops)->probe(buf, buf_len);
47                 if (!ret) {
48                         image->fops = *fops;
49                         return ret;
50                 }
51         }
52
53         return ret;
54 }
55
56 /* Architectures can provide this probe function */
57 int __weak arch_kexec_kernel_image_probe(struct kimage *image, void *buf,
58                                          unsigned long buf_len)
59 {
60         return kexec_image_probe_default(image, buf, buf_len);
61 }
62
63 static void *kexec_image_load_default(struct kimage *image)
64 {
65         if (!image->fops || !image->fops->load)
66                 return ERR_PTR(-ENOEXEC);
67
68         return image->fops->load(image, image->kernel_buf,
69                                  image->kernel_buf_len, image->initrd_buf,
70                                  image->initrd_buf_len, image->cmdline_buf,
71                                  image->cmdline_buf_len);
72 }
73
74 void * __weak arch_kexec_kernel_image_load(struct kimage *image)
75 {
76         return kexec_image_load_default(image);
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 int __weak arch_kimage_file_post_load_cleanup(struct kimage *image)
88 {
89         return kexec_image_post_load_cleanup_default(image);
90 }
91
92 #ifdef CONFIG_KEXEC_SIG
93 static int kexec_image_verify_sig_default(struct kimage *image, void *buf,
94                                           unsigned long buf_len)
95 {
96         if (!image->fops || !image->fops->verify_sig) {
97                 pr_debug("kernel loader does not support signature verification.\n");
98                 return -EKEYREJECTED;
99         }
100
101         return image->fops->verify_sig(buf, buf_len);
102 }
103
104 int __weak arch_kexec_kernel_verify_sig(struct kimage *image, void *buf,
105                                         unsigned long buf_len)
106 {
107         return kexec_image_verify_sig_default(image, buf, buf_len);
108 }
109 #endif
110
111 /*
112  * arch_kexec_apply_relocations_add - apply relocations of type RELA
113  * @pi:         Purgatory to be relocated.
114  * @section:    Section relocations applying to.
115  * @relsec:     Section containing RELAs.
116  * @symtab:     Corresponding symtab.
117  *
118  * Return: 0 on success, negative errno on error.
119  */
120 int __weak
121 arch_kexec_apply_relocations_add(struct purgatory_info *pi, Elf_Shdr *section,
122                                  const Elf_Shdr *relsec, const Elf_Shdr *symtab)
123 {
124         pr_err("RELA relocation unsupported.\n");
125         return -ENOEXEC;
126 }
127
128 /*
129  * arch_kexec_apply_relocations - apply relocations of type REL
130  * @pi:         Purgatory to be relocated.
131  * @section:    Section relocations applying to.
132  * @relsec:     Section containing RELs.
133  * @symtab:     Corresponding symtab.
134  *
135  * Return: 0 on success, negative errno on error.
136  */
137 int __weak
138 arch_kexec_apply_relocations(struct purgatory_info *pi, Elf_Shdr *section,
139                              const Elf_Shdr *relsec, const Elf_Shdr *symtab)
140 {
141         pr_err("REL relocation unsupported.\n");
142         return -ENOEXEC;
143 }
144
145 /*
146  * Free up memory used by kernel, initrd, and command line. This is temporary
147  * memory allocation which is not needed any more after these buffers have
148  * been loaded into separate segments and have been copied elsewhere.
149  */
150 void kimage_file_post_load_cleanup(struct kimage *image)
151 {
152         struct purgatory_info *pi = &image->purgatory_info;
153
154         vfree(image->kernel_buf);
155         image->kernel_buf = NULL;
156
157         vfree(image->initrd_buf);
158         image->initrd_buf = NULL;
159
160         kfree(image->cmdline_buf);
161         image->cmdline_buf = NULL;
162
163         vfree(pi->purgatory_buf);
164         pi->purgatory_buf = NULL;
165
166         vfree(pi->sechdrs);
167         pi->sechdrs = NULL;
168
169 #ifdef CONFIG_IMA_KEXEC
170         vfree(image->ima_buffer);
171         image->ima_buffer = NULL;
172 #endif /* CONFIG_IMA_KEXEC */
173
174         /* See if architecture has anything to cleanup post load */
175         arch_kimage_file_post_load_cleanup(image);
176
177         /*
178          * Above call should have called into bootloader to free up
179          * any data stored in kimage->image_loader_data. It should
180          * be ok now to free it up.
181          */
182         kfree(image->image_loader_data);
183         image->image_loader_data = NULL;
184 }
185
186 #ifdef CONFIG_KEXEC_SIG
187 static int
188 kimage_validate_signature(struct kimage *image)
189 {
190         int ret;
191
192         ret = arch_kexec_kernel_verify_sig(image, image->kernel_buf,
193                                            image->kernel_buf_len);
194         if (ret) {
195
196                 if (IS_ENABLED(CONFIG_KEXEC_SIG_FORCE)) {
197                         pr_notice("Enforced kernel signature verification failed (%d).\n", ret);
198                         return ret;
199                 }
200
201                 /*
202                  * If IMA is guaranteed to appraise a signature on the kexec
203                  * image, permit it even if the kernel is otherwise locked
204                  * down.
205                  */
206                 if (!ima_appraise_signature(READING_KEXEC_IMAGE) &&
207                     security_locked_down(LOCKDOWN_KEXEC))
208                         return -EPERM;
209
210                 pr_debug("kernel signature verification failed (%d).\n", ret);
211         }
212
213         return 0;
214 }
215 #endif
216
217 /*
218  * In file mode list of segments is prepared by kernel. Copy relevant
219  * data from user space, do error checking, prepare segment list
220  */
221 static int
222 kimage_file_prepare_segments(struct kimage *image, int kernel_fd, int initrd_fd,
223                              const char __user *cmdline_ptr,
224                              unsigned long cmdline_len, unsigned flags)
225 {
226         int ret;
227         void *ldata;
228
229         ret = kernel_read_file_from_fd(kernel_fd, 0, &image->kernel_buf,
230                                        INT_MAX, NULL, READING_KEXEC_IMAGE);
231         if (ret < 0)
232                 return ret;
233         image->kernel_buf_len = ret;
234
235         /* Call arch image probe handlers */
236         ret = arch_kexec_kernel_image_probe(image, image->kernel_buf,
237                                             image->kernel_buf_len);
238         if (ret)
239                 goto out;
240
241 #ifdef CONFIG_KEXEC_SIG
242         ret = kimage_validate_signature(image);
243
244         if (ret)
245                 goto out;
246 #endif
247         /* It is possible that there no initramfs is being loaded */
248         if (!(flags & KEXEC_FILE_NO_INITRAMFS)) {
249                 ret = kernel_read_file_from_fd(initrd_fd, 0, &image->initrd_buf,
250                                                INT_MAX, NULL,
251                                                READING_KEXEC_INITRAMFS);
252                 if (ret < 0)
253                         goto out;
254                 image->initrd_buf_len = ret;
255                 ret = 0;
256         }
257
258         if (cmdline_len) {
259                 image->cmdline_buf = memdup_user(cmdline_ptr, cmdline_len);
260                 if (IS_ERR(image->cmdline_buf)) {
261                         ret = PTR_ERR(image->cmdline_buf);
262                         image->cmdline_buf = NULL;
263                         goto out;
264                 }
265
266                 image->cmdline_buf_len = cmdline_len;
267
268                 /* command line should be a string with last byte null */
269                 if (image->cmdline_buf[cmdline_len - 1] != '\0') {
270                         ret = -EINVAL;
271                         goto out;
272                 }
273
274                 ima_kexec_cmdline(kernel_fd, image->cmdline_buf,
275                                   image->cmdline_buf_len - 1);
276         }
277
278         /* IMA needs to pass the measurement list to the next kernel. */
279         ima_add_kexec_buffer(image);
280
281         /* Call arch image load handlers */
282         ldata = arch_kexec_kernel_image_load(image);
283
284         if (IS_ERR(ldata)) {
285                 ret = PTR_ERR(ldata);
286                 goto out;
287         }
288
289         image->image_loader_data = ldata;
290 out:
291         /* In case of error, free up all allocated memory in this function */
292         if (ret)
293                 kimage_file_post_load_cleanup(image);
294         return ret;
295 }
296
297 static int
298 kimage_file_alloc_init(struct kimage **rimage, int kernel_fd,
299                        int initrd_fd, const char __user *cmdline_ptr,
300                        unsigned long cmdline_len, unsigned long flags)
301 {
302         int ret;
303         struct kimage *image;
304         bool kexec_on_panic = flags & KEXEC_FILE_ON_CRASH;
305
306         image = do_kimage_alloc_init();
307         if (!image)
308                 return -ENOMEM;
309
310         image->file_mode = 1;
311
312         if (kexec_on_panic) {
313                 /* Enable special crash kernel control page alloc policy. */
314                 image->control_page = crashk_res.start;
315                 image->type = KEXEC_TYPE_CRASH;
316         }
317
318         ret = kimage_file_prepare_segments(image, kernel_fd, initrd_fd,
319                                            cmdline_ptr, cmdline_len, flags);
320         if (ret)
321                 goto out_free_image;
322
323         ret = sanity_check_segment_list(image);
324         if (ret)
325                 goto out_free_post_load_bufs;
326
327         ret = -ENOMEM;
328         image->control_code_page = kimage_alloc_control_pages(image,
329                                            get_order(KEXEC_CONTROL_PAGE_SIZE));
330         if (!image->control_code_page) {
331                 pr_err("Could not allocate control_code_buffer\n");
332                 goto out_free_post_load_bufs;
333         }
334
335         if (!kexec_on_panic) {
336                 image->swap_page = kimage_alloc_control_pages(image, 0);
337                 if (!image->swap_page) {
338                         pr_err("Could not allocate swap buffer\n");
339                         goto out_free_control_pages;
340                 }
341         }
342
343         *rimage = image;
344         return 0;
345 out_free_control_pages:
346         kimage_free_page_list(&image->control_pages);
347 out_free_post_load_bufs:
348         kimage_file_post_load_cleanup(image);
349 out_free_image:
350         kfree(image);
351         return ret;
352 }
353
354 SYSCALL_DEFINE5(kexec_file_load, int, kernel_fd, int, initrd_fd,
355                 unsigned long, cmdline_len, const char __user *, cmdline_ptr,
356                 unsigned long, flags)
357 {
358         int ret = 0, i;
359         struct kimage **dest_image, *image;
360
361         /* We only trust the superuser with rebooting the system. */
362         if (!capable(CAP_SYS_BOOT) || kexec_load_disabled)
363                 return -EPERM;
364
365         /* Make sure we have a legal set of flags */
366         if (flags != (flags & KEXEC_FILE_FLAGS))
367                 return -EINVAL;
368
369         image = NULL;
370
371         if (!mutex_trylock(&kexec_mutex))
372                 return -EBUSY;
373
374         dest_image = &kexec_image;
375         if (flags & KEXEC_FILE_ON_CRASH) {
376                 dest_image = &kexec_crash_image;
377                 if (kexec_crash_image)
378                         arch_kexec_unprotect_crashkres();
379         }
380
381         if (flags & KEXEC_FILE_UNLOAD)
382                 goto exchange;
383
384         /*
385          * In case of crash, new kernel gets loaded in reserved region. It is
386          * same memory where old crash kernel might be loaded. Free any
387          * current crash dump kernel before we corrupt it.
388          */
389         if (flags & KEXEC_FILE_ON_CRASH)
390                 kimage_free(xchg(&kexec_crash_image, NULL));
391
392         ret = kimage_file_alloc_init(&image, kernel_fd, initrd_fd, cmdline_ptr,
393                                      cmdline_len, flags);
394         if (ret)
395                 goto out;
396
397         ret = machine_kexec_prepare(image);
398         if (ret)
399                 goto out;
400
401         /*
402          * Some architecture(like S390) may touch the crash memory before
403          * machine_kexec_prepare(), we must copy vmcoreinfo data after it.
404          */
405         ret = kimage_crash_copy_vmcoreinfo(image);
406         if (ret)
407                 goto out;
408
409         ret = kexec_calculate_store_digests(image);
410         if (ret)
411                 goto out;
412
413         for (i = 0; i < image->nr_segments; i++) {
414                 struct kexec_segment *ksegment;
415
416                 ksegment = &image->segment[i];
417                 pr_debug("Loading segment %d: buf=0x%p bufsz=0x%zx mem=0x%lx memsz=0x%zx\n",
418                          i, ksegment->buf, ksegment->bufsz, ksegment->mem,
419                          ksegment->memsz);
420
421                 ret = kimage_load_segment(image, &image->segment[i]);
422                 if (ret)
423                         goto out;
424         }
425
426         kimage_terminate(image);
427
428         ret = machine_kexec_post_load(image);
429         if (ret)
430                 goto out;
431
432         /*
433          * Free up any temporary buffers allocated which are not needed
434          * after image has been loaded
435          */
436         kimage_file_post_load_cleanup(image);
437 exchange:
438         image = xchg(dest_image, image);
439 out:
440         if ((flags & KEXEC_FILE_ON_CRASH) && kexec_crash_image)
441                 arch_kexec_protect_crashkres();
442
443         mutex_unlock(&kexec_mutex);
444         kimage_free(image);
445         return ret;
446 }
447
448 static int locate_mem_hole_top_down(unsigned long start, unsigned long end,
449                                     struct kexec_buf *kbuf)
450 {
451         struct kimage *image = kbuf->image;
452         unsigned long temp_start, temp_end;
453
454         temp_end = min(end, kbuf->buf_max);
455         temp_start = temp_end - kbuf->memsz;
456
457         do {
458                 /* align down start */
459                 temp_start = temp_start & (~(kbuf->buf_align - 1));
460
461                 if (temp_start < start || temp_start < kbuf->buf_min)
462                         return 0;
463
464                 temp_end = temp_start + kbuf->memsz - 1;
465
466                 /*
467                  * Make sure this does not conflict with any of existing
468                  * segments
469                  */
470                 if (kimage_is_destination_range(image, temp_start, temp_end)) {
471                         temp_start = temp_start - PAGE_SIZE;
472                         continue;
473                 }
474
475                 /* We found a suitable memory range */
476                 break;
477         } while (1);
478
479         /* If we are here, we found a suitable memory range */
480         kbuf->mem = temp_start;
481
482         /* Success, stop navigating through remaining System RAM ranges */
483         return 1;
484 }
485
486 static int locate_mem_hole_bottom_up(unsigned long start, unsigned long end,
487                                      struct kexec_buf *kbuf)
488 {
489         struct kimage *image = kbuf->image;
490         unsigned long temp_start, temp_end;
491
492         temp_start = max(start, kbuf->buf_min);
493
494         do {
495                 temp_start = ALIGN(temp_start, kbuf->buf_align);
496                 temp_end = temp_start + kbuf->memsz - 1;
497
498                 if (temp_end > end || temp_end > kbuf->buf_max)
499                         return 0;
500                 /*
501                  * Make sure this does not conflict with any of existing
502                  * segments
503                  */
504                 if (kimage_is_destination_range(image, temp_start, temp_end)) {
505                         temp_start = temp_start + PAGE_SIZE;
506                         continue;
507                 }
508
509                 /* We found a suitable memory range */
510                 break;
511         } while (1);
512
513         /* If we are here, we found a suitable memory range */
514         kbuf->mem = temp_start;
515
516         /* Success, stop navigating through remaining System RAM ranges */
517         return 1;
518 }
519
520 static int locate_mem_hole_callback(struct resource *res, void *arg)
521 {
522         struct kexec_buf *kbuf = (struct kexec_buf *)arg;
523         u64 start = res->start, end = res->end;
524         unsigned long sz = end - start + 1;
525
526         /* Returning 0 will take to next memory range */
527
528         /* Don't use memory that will be detected and handled by a driver. */
529         if (res->flags & IORESOURCE_SYSRAM_DRIVER_MANAGED)
530                 return 0;
531
532         if (sz < kbuf->memsz)
533                 return 0;
534
535         if (end < kbuf->buf_min || start > kbuf->buf_max)
536                 return 0;
537
538         /*
539          * Allocate memory top down with-in ram range. Otherwise bottom up
540          * allocation.
541          */
542         if (kbuf->top_down)
543                 return locate_mem_hole_top_down(start, end, kbuf);
544         return locate_mem_hole_bottom_up(start, end, kbuf);
545 }
546
547 #ifdef CONFIG_ARCH_KEEP_MEMBLOCK
548 static int kexec_walk_memblock(struct kexec_buf *kbuf,
549                                int (*func)(struct resource *, void *))
550 {
551         int ret = 0;
552         u64 i;
553         phys_addr_t mstart, mend;
554         struct resource res = { };
555
556         if (kbuf->image->type == KEXEC_TYPE_CRASH)
557                 return func(&crashk_res, kbuf);
558
559         /*
560          * Using MEMBLOCK_NONE will properly skip MEMBLOCK_DRIVER_MANAGED. See
561          * IORESOURCE_SYSRAM_DRIVER_MANAGED handling in
562          * locate_mem_hole_callback().
563          */
564         if (kbuf->top_down) {
565                 for_each_free_mem_range_reverse(i, NUMA_NO_NODE, MEMBLOCK_NONE,
566                                                 &mstart, &mend, NULL) {
567                         /*
568                          * In memblock, end points to the first byte after the
569                          * range while in kexec, end points to the last byte
570                          * in the range.
571                          */
572                         res.start = mstart;
573                         res.end = mend - 1;
574                         ret = func(&res, kbuf);
575                         if (ret)
576                                 break;
577                 }
578         } else {
579                 for_each_free_mem_range(i, NUMA_NO_NODE, MEMBLOCK_NONE,
580                                         &mstart, &mend, NULL) {
581                         /*
582                          * In memblock, end points to the first byte after the
583                          * range while in kexec, end points to the last byte
584                          * in the range.
585                          */
586                         res.start = mstart;
587                         res.end = mend - 1;
588                         ret = func(&res, kbuf);
589                         if (ret)
590                                 break;
591                 }
592         }
593
594         return ret;
595 }
596 #else
597 static int kexec_walk_memblock(struct kexec_buf *kbuf,
598                                int (*func)(struct resource *, void *))
599 {
600         return 0;
601 }
602 #endif
603
604 /**
605  * kexec_walk_resources - call func(data) on free memory regions
606  * @kbuf:       Context info for the search. Also passed to @func.
607  * @func:       Function to call for each memory region.
608  *
609  * Return: The memory walk will stop when func returns a non-zero value
610  * and that value will be returned. If all free regions are visited without
611  * func returning non-zero, then zero will be returned.
612  */
613 static int kexec_walk_resources(struct kexec_buf *kbuf,
614                                 int (*func)(struct resource *, void *))
615 {
616         if (kbuf->image->type == KEXEC_TYPE_CRASH)
617                 return walk_iomem_res_desc(crashk_res.desc,
618                                            IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY,
619                                            crashk_res.start, crashk_res.end,
620                                            kbuf, func);
621         else
622                 return walk_system_ram_res(0, ULONG_MAX, kbuf, func);
623 }
624
625 /**
626  * kexec_locate_mem_hole - find free memory for the purgatory or the next kernel
627  * @kbuf:       Parameters for the memory search.
628  *
629  * On success, kbuf->mem will have the start address of the memory region found.
630  *
631  * Return: 0 on success, negative errno on error.
632  */
633 int kexec_locate_mem_hole(struct kexec_buf *kbuf)
634 {
635         int ret;
636
637         /* Arch knows where to place */
638         if (kbuf->mem != KEXEC_BUF_MEM_UNKNOWN)
639                 return 0;
640
641         if (!IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK))
642                 ret = kexec_walk_resources(kbuf, locate_mem_hole_callback);
643         else
644                 ret = kexec_walk_memblock(kbuf, locate_mem_hole_callback);
645
646         return ret == 1 ? 0 : -EADDRNOTAVAIL;
647 }
648
649 /**
650  * arch_kexec_locate_mem_hole - Find free memory to place the segments.
651  * @kbuf:                       Parameters for the memory search.
652  *
653  * On success, kbuf->mem will have the start address of the memory region found.
654  *
655  * Return: 0 on success, negative errno on error.
656  */
657 int __weak arch_kexec_locate_mem_hole(struct kexec_buf *kbuf)
658 {
659         return kexec_locate_mem_hole(kbuf);
660 }
661
662 /**
663  * kexec_add_buffer - place a buffer in a kexec segment
664  * @kbuf:       Buffer contents and memory parameters.
665  *
666  * This function assumes that kexec_mutex is held.
667  * On successful return, @kbuf->mem will have the physical address of
668  * the buffer in memory.
669  *
670  * Return: 0 on success, negative errno on error.
671  */
672 int kexec_add_buffer(struct kexec_buf *kbuf)
673 {
674         struct kexec_segment *ksegment;
675         int ret;
676
677         /* Currently adding segment this way is allowed only in file mode */
678         if (!kbuf->image->file_mode)
679                 return -EINVAL;
680
681         if (kbuf->image->nr_segments >= KEXEC_SEGMENT_MAX)
682                 return -EINVAL;
683
684         /*
685          * Make sure we are not trying to add buffer after allocating
686          * control pages. All segments need to be placed first before
687          * any control pages are allocated. As control page allocation
688          * logic goes through list of segments to make sure there are
689          * no destination overlaps.
690          */
691         if (!list_empty(&kbuf->image->control_pages)) {
692                 WARN_ON(1);
693                 return -EINVAL;
694         }
695
696         /* Ensure minimum alignment needed for segments. */
697         kbuf->memsz = ALIGN(kbuf->memsz, PAGE_SIZE);
698         kbuf->buf_align = max(kbuf->buf_align, PAGE_SIZE);
699
700         /* Walk the RAM ranges and allocate a suitable range for the buffer */
701         ret = arch_kexec_locate_mem_hole(kbuf);
702         if (ret)
703                 return ret;
704
705         /* Found a suitable memory range */
706         ksegment = &kbuf->image->segment[kbuf->image->nr_segments];
707         ksegment->kbuf = kbuf->buffer;
708         ksegment->bufsz = kbuf->bufsz;
709         ksegment->mem = kbuf->mem;
710         ksegment->memsz = kbuf->memsz;
711         kbuf->image->nr_segments++;
712         return 0;
713 }
714
715 /* Calculate and store the digest of segments */
716 static int kexec_calculate_store_digests(struct kimage *image)
717 {
718         struct crypto_shash *tfm;
719         struct shash_desc *desc;
720         int ret = 0, i, j, zero_buf_sz, sha_region_sz;
721         size_t desc_size, nullsz;
722         char *digest;
723         void *zero_buf;
724         struct kexec_sha_region *sha_regions;
725         struct purgatory_info *pi = &image->purgatory_info;
726
727         if (!IS_ENABLED(CONFIG_ARCH_HAS_KEXEC_PURGATORY))
728                 return 0;
729
730         zero_buf = __va(page_to_pfn(ZERO_PAGE(0)) << PAGE_SHIFT);
731         zero_buf_sz = PAGE_SIZE;
732
733         tfm = crypto_alloc_shash("sha256", 0, 0);
734         if (IS_ERR(tfm)) {
735                 ret = PTR_ERR(tfm);
736                 goto out;
737         }
738
739         desc_size = crypto_shash_descsize(tfm) + sizeof(*desc);
740         desc = kzalloc(desc_size, GFP_KERNEL);
741         if (!desc) {
742                 ret = -ENOMEM;
743                 goto out_free_tfm;
744         }
745
746         sha_region_sz = KEXEC_SEGMENT_MAX * sizeof(struct kexec_sha_region);
747         sha_regions = vzalloc(sha_region_sz);
748         if (!sha_regions) {
749                 ret = -ENOMEM;
750                 goto out_free_desc;
751         }
752
753         desc->tfm   = tfm;
754
755         ret = crypto_shash_init(desc);
756         if (ret < 0)
757                 goto out_free_sha_regions;
758
759         digest = kzalloc(SHA256_DIGEST_SIZE, GFP_KERNEL);
760         if (!digest) {
761                 ret = -ENOMEM;
762                 goto out_free_sha_regions;
763         }
764
765         for (j = i = 0; i < image->nr_segments; i++) {
766                 struct kexec_segment *ksegment;
767
768                 ksegment = &image->segment[i];
769                 /*
770                  * Skip purgatory as it will be modified once we put digest
771                  * info in purgatory.
772                  */
773                 if (ksegment->kbuf == pi->purgatory_buf)
774                         continue;
775
776                 ret = crypto_shash_update(desc, ksegment->kbuf,
777                                           ksegment->bufsz);
778                 if (ret)
779                         break;
780
781                 /*
782                  * Assume rest of the buffer is filled with zero and
783                  * update digest accordingly.
784                  */
785                 nullsz = ksegment->memsz - ksegment->bufsz;
786                 while (nullsz) {
787                         unsigned long bytes = nullsz;
788
789                         if (bytes > zero_buf_sz)
790                                 bytes = zero_buf_sz;
791                         ret = crypto_shash_update(desc, zero_buf, bytes);
792                         if (ret)
793                                 break;
794                         nullsz -= bytes;
795                 }
796
797                 if (ret)
798                         break;
799
800                 sha_regions[j].start = ksegment->mem;
801                 sha_regions[j].len = ksegment->memsz;
802                 j++;
803         }
804
805         if (!ret) {
806                 ret = crypto_shash_final(desc, digest);
807                 if (ret)
808                         goto out_free_digest;
809                 ret = kexec_purgatory_get_set_symbol(image, "purgatory_sha_regions",
810                                                      sha_regions, sha_region_sz, 0);
811                 if (ret)
812                         goto out_free_digest;
813
814                 ret = kexec_purgatory_get_set_symbol(image, "purgatory_sha256_digest",
815                                                      digest, SHA256_DIGEST_SIZE, 0);
816                 if (ret)
817                         goto out_free_digest;
818         }
819
820 out_free_digest:
821         kfree(digest);
822 out_free_sha_regions:
823         vfree(sha_regions);
824 out_free_desc:
825         kfree(desc);
826 out_free_tfm:
827         kfree(tfm);
828 out:
829         return ret;
830 }
831
832 #ifdef CONFIG_ARCH_HAS_KEXEC_PURGATORY
833 /*
834  * kexec_purgatory_setup_kbuf - prepare buffer to load purgatory.
835  * @pi:         Purgatory to be loaded.
836  * @kbuf:       Buffer to setup.
837  *
838  * Allocates the memory needed for the buffer. Caller is responsible to free
839  * the memory after use.
840  *
841  * Return: 0 on success, negative errno on error.
842  */
843 static int kexec_purgatory_setup_kbuf(struct purgatory_info *pi,
844                                       struct kexec_buf *kbuf)
845 {
846         const Elf_Shdr *sechdrs;
847         unsigned long bss_align;
848         unsigned long bss_sz;
849         unsigned long align;
850         int i, ret;
851
852         sechdrs = (void *)pi->ehdr + pi->ehdr->e_shoff;
853         kbuf->buf_align = bss_align = 1;
854         kbuf->bufsz = bss_sz = 0;
855
856         for (i = 0; i < pi->ehdr->e_shnum; i++) {
857                 if (!(sechdrs[i].sh_flags & SHF_ALLOC))
858                         continue;
859
860                 align = sechdrs[i].sh_addralign;
861                 if (sechdrs[i].sh_type != SHT_NOBITS) {
862                         if (kbuf->buf_align < align)
863                                 kbuf->buf_align = align;
864                         kbuf->bufsz = ALIGN(kbuf->bufsz, align);
865                         kbuf->bufsz += sechdrs[i].sh_size;
866                 } else {
867                         if (bss_align < align)
868                                 bss_align = align;
869                         bss_sz = ALIGN(bss_sz, align);
870                         bss_sz += sechdrs[i].sh_size;
871                 }
872         }
873         kbuf->bufsz = ALIGN(kbuf->bufsz, bss_align);
874         kbuf->memsz = kbuf->bufsz + bss_sz;
875         if (kbuf->buf_align < bss_align)
876                 kbuf->buf_align = bss_align;
877
878         kbuf->buffer = vzalloc(kbuf->bufsz);
879         if (!kbuf->buffer)
880                 return -ENOMEM;
881         pi->purgatory_buf = kbuf->buffer;
882
883         ret = kexec_add_buffer(kbuf);
884         if (ret)
885                 goto out;
886
887         return 0;
888 out:
889         vfree(pi->purgatory_buf);
890         pi->purgatory_buf = NULL;
891         return ret;
892 }
893
894 /*
895  * kexec_purgatory_setup_sechdrs - prepares the pi->sechdrs buffer.
896  * @pi:         Purgatory to be loaded.
897  * @kbuf:       Buffer prepared to store purgatory.
898  *
899  * Allocates the memory needed for the buffer. Caller is responsible to free
900  * the memory after use.
901  *
902  * Return: 0 on success, negative errno on error.
903  */
904 static int kexec_purgatory_setup_sechdrs(struct purgatory_info *pi,
905                                          struct kexec_buf *kbuf)
906 {
907         unsigned long bss_addr;
908         unsigned long offset;
909         Elf_Shdr *sechdrs;
910         int i;
911
912         /*
913          * The section headers in kexec_purgatory are read-only. In order to
914          * have them modifiable make a temporary copy.
915          */
916         sechdrs = vzalloc(array_size(sizeof(Elf_Shdr), pi->ehdr->e_shnum));
917         if (!sechdrs)
918                 return -ENOMEM;
919         memcpy(sechdrs, (void *)pi->ehdr + pi->ehdr->e_shoff,
920                pi->ehdr->e_shnum * sizeof(Elf_Shdr));
921         pi->sechdrs = sechdrs;
922
923         offset = 0;
924         bss_addr = kbuf->mem + kbuf->bufsz;
925         kbuf->image->start = pi->ehdr->e_entry;
926
927         for (i = 0; i < pi->ehdr->e_shnum; i++) {
928                 unsigned long align;
929                 void *src, *dst;
930
931                 if (!(sechdrs[i].sh_flags & SHF_ALLOC))
932                         continue;
933
934                 align = sechdrs[i].sh_addralign;
935                 if (sechdrs[i].sh_type == SHT_NOBITS) {
936                         bss_addr = ALIGN(bss_addr, align);
937                         sechdrs[i].sh_addr = bss_addr;
938                         bss_addr += sechdrs[i].sh_size;
939                         continue;
940                 }
941
942                 offset = ALIGN(offset, align);
943                 if (sechdrs[i].sh_flags & SHF_EXECINSTR &&
944                     pi->ehdr->e_entry >= sechdrs[i].sh_addr &&
945                     pi->ehdr->e_entry < (sechdrs[i].sh_addr
946                                          + sechdrs[i].sh_size)) {
947                         kbuf->image->start -= sechdrs[i].sh_addr;
948                         kbuf->image->start += kbuf->mem + offset;
949                 }
950
951                 src = (void *)pi->ehdr + sechdrs[i].sh_offset;
952                 dst = pi->purgatory_buf + offset;
953                 memcpy(dst, src, sechdrs[i].sh_size);
954
955                 sechdrs[i].sh_addr = kbuf->mem + offset;
956                 sechdrs[i].sh_offset = offset;
957                 offset += sechdrs[i].sh_size;
958         }
959
960         return 0;
961 }
962
963 static int kexec_apply_relocations(struct kimage *image)
964 {
965         int i, ret;
966         struct purgatory_info *pi = &image->purgatory_info;
967         const Elf_Shdr *sechdrs;
968
969         sechdrs = (void *)pi->ehdr + pi->ehdr->e_shoff;
970
971         for (i = 0; i < pi->ehdr->e_shnum; i++) {
972                 const Elf_Shdr *relsec;
973                 const Elf_Shdr *symtab;
974                 Elf_Shdr *section;
975
976                 relsec = sechdrs + i;
977
978                 if (relsec->sh_type != SHT_RELA &&
979                     relsec->sh_type != SHT_REL)
980                         continue;
981
982                 /*
983                  * For section of type SHT_RELA/SHT_REL,
984                  * ->sh_link contains section header index of associated
985                  * symbol table. And ->sh_info contains section header
986                  * index of section to which relocations apply.
987                  */
988                 if (relsec->sh_info >= pi->ehdr->e_shnum ||
989                     relsec->sh_link >= pi->ehdr->e_shnum)
990                         return -ENOEXEC;
991
992                 section = pi->sechdrs + relsec->sh_info;
993                 symtab = sechdrs + relsec->sh_link;
994
995                 if (!(section->sh_flags & SHF_ALLOC))
996                         continue;
997
998                 /*
999                  * symtab->sh_link contain section header index of associated
1000                  * string table.
1001                  */
1002                 if (symtab->sh_link >= pi->ehdr->e_shnum)
1003                         /* Invalid section number? */
1004                         continue;
1005
1006                 /*
1007                  * Respective architecture needs to provide support for applying
1008                  * relocations of type SHT_RELA/SHT_REL.
1009                  */
1010                 if (relsec->sh_type == SHT_RELA)
1011                         ret = arch_kexec_apply_relocations_add(pi, section,
1012                                                                relsec, symtab);
1013                 else if (relsec->sh_type == SHT_REL)
1014                         ret = arch_kexec_apply_relocations(pi, section,
1015                                                            relsec, symtab);
1016                 if (ret)
1017                         return ret;
1018         }
1019
1020         return 0;
1021 }
1022
1023 /*
1024  * kexec_load_purgatory - Load and relocate the purgatory object.
1025  * @image:      Image to add the purgatory to.
1026  * @kbuf:       Memory parameters to use.
1027  *
1028  * Allocates the memory needed for image->purgatory_info.sechdrs and
1029  * image->purgatory_info.purgatory_buf/kbuf->buffer. Caller is responsible
1030  * to free the memory after use.
1031  *
1032  * Return: 0 on success, negative errno on error.
1033  */
1034 int kexec_load_purgatory(struct kimage *image, struct kexec_buf *kbuf)
1035 {
1036         struct purgatory_info *pi = &image->purgatory_info;
1037         int ret;
1038
1039         if (kexec_purgatory_size <= 0)
1040                 return -EINVAL;
1041
1042         pi->ehdr = (const Elf_Ehdr *)kexec_purgatory;
1043
1044         ret = kexec_purgatory_setup_kbuf(pi, kbuf);
1045         if (ret)
1046                 return ret;
1047
1048         ret = kexec_purgatory_setup_sechdrs(pi, kbuf);
1049         if (ret)
1050                 goto out_free_kbuf;
1051
1052         ret = kexec_apply_relocations(image);
1053         if (ret)
1054                 goto out;
1055
1056         return 0;
1057 out:
1058         vfree(pi->sechdrs);
1059         pi->sechdrs = NULL;
1060 out_free_kbuf:
1061         vfree(pi->purgatory_buf);
1062         pi->purgatory_buf = NULL;
1063         return ret;
1064 }
1065
1066 /*
1067  * kexec_purgatory_find_symbol - find a symbol in the purgatory
1068  * @pi:         Purgatory to search in.
1069  * @name:       Name of the symbol.
1070  *
1071  * Return: pointer to symbol in read-only symtab on success, NULL on error.
1072  */
1073 static const Elf_Sym *kexec_purgatory_find_symbol(struct purgatory_info *pi,
1074                                                   const char *name)
1075 {
1076         const Elf_Shdr *sechdrs;
1077         const Elf_Ehdr *ehdr;
1078         const Elf_Sym *syms;
1079         const char *strtab;
1080         int i, k;
1081
1082         if (!pi->ehdr)
1083                 return NULL;
1084
1085         ehdr = pi->ehdr;
1086         sechdrs = (void *)ehdr + ehdr->e_shoff;
1087
1088         for (i = 0; i < ehdr->e_shnum; i++) {
1089                 if (sechdrs[i].sh_type != SHT_SYMTAB)
1090                         continue;
1091
1092                 if (sechdrs[i].sh_link >= ehdr->e_shnum)
1093                         /* Invalid strtab section number */
1094                         continue;
1095                 strtab = (void *)ehdr + sechdrs[sechdrs[i].sh_link].sh_offset;
1096                 syms = (void *)ehdr + sechdrs[i].sh_offset;
1097
1098                 /* Go through symbols for a match */
1099                 for (k = 0; k < sechdrs[i].sh_size/sizeof(Elf_Sym); k++) {
1100                         if (ELF_ST_BIND(syms[k].st_info) != STB_GLOBAL)
1101                                 continue;
1102
1103                         if (strcmp(strtab + syms[k].st_name, name) != 0)
1104                                 continue;
1105
1106                         if (syms[k].st_shndx == SHN_UNDEF ||
1107                             syms[k].st_shndx >= ehdr->e_shnum) {
1108                                 pr_debug("Symbol: %s has bad section index %d.\n",
1109                                                 name, syms[k].st_shndx);
1110                                 return NULL;
1111                         }
1112
1113                         /* Found the symbol we are looking for */
1114                         return &syms[k];
1115                 }
1116         }
1117
1118         return NULL;
1119 }
1120
1121 void *kexec_purgatory_get_symbol_addr(struct kimage *image, const char *name)
1122 {
1123         struct purgatory_info *pi = &image->purgatory_info;
1124         const Elf_Sym *sym;
1125         Elf_Shdr *sechdr;
1126
1127         sym = kexec_purgatory_find_symbol(pi, name);
1128         if (!sym)
1129                 return ERR_PTR(-EINVAL);
1130
1131         sechdr = &pi->sechdrs[sym->st_shndx];
1132
1133         /*
1134          * Returns the address where symbol will finally be loaded after
1135          * kexec_load_segment()
1136          */
1137         return (void *)(sechdr->sh_addr + sym->st_value);
1138 }
1139
1140 /*
1141  * Get or set value of a symbol. If "get_value" is true, symbol value is
1142  * returned in buf otherwise symbol value is set based on value in buf.
1143  */
1144 int kexec_purgatory_get_set_symbol(struct kimage *image, const char *name,
1145                                    void *buf, unsigned int size, bool get_value)
1146 {
1147         struct purgatory_info *pi = &image->purgatory_info;
1148         const Elf_Sym *sym;
1149         Elf_Shdr *sec;
1150         char *sym_buf;
1151
1152         sym = kexec_purgatory_find_symbol(pi, name);
1153         if (!sym)
1154                 return -EINVAL;
1155
1156         if (sym->st_size != size) {
1157                 pr_err("symbol %s size mismatch: expected %lu actual %u\n",
1158                        name, (unsigned long)sym->st_size, size);
1159                 return -EINVAL;
1160         }
1161
1162         sec = pi->sechdrs + sym->st_shndx;
1163
1164         if (sec->sh_type == SHT_NOBITS) {
1165                 pr_err("symbol %s is in a bss section. Cannot %s\n", name,
1166                        get_value ? "get" : "set");
1167                 return -EINVAL;
1168         }
1169
1170         sym_buf = (char *)pi->purgatory_buf + sec->sh_offset + sym->st_value;
1171
1172         if (get_value)
1173                 memcpy((void *)buf, sym_buf, size);
1174         else
1175                 memcpy((void *)sym_buf, buf, size);
1176
1177         return 0;
1178 }
1179 #endif /* CONFIG_ARCH_HAS_KEXEC_PURGATORY */
1180
1181 int crash_exclude_mem_range(struct crash_mem *mem,
1182                             unsigned long long mstart, unsigned long long mend)
1183 {
1184         int i, j;
1185         unsigned long long start, end, p_start, p_end;
1186         struct crash_mem_range temp_range = {0, 0};
1187
1188         for (i = 0; i < mem->nr_ranges; i++) {
1189                 start = mem->ranges[i].start;
1190                 end = mem->ranges[i].end;
1191                 p_start = mstart;
1192                 p_end = mend;
1193
1194                 if (mstart > end || mend < start)
1195                         continue;
1196
1197                 /* Truncate any area outside of range */
1198                 if (mstart < start)
1199                         p_start = start;
1200                 if (mend > end)
1201                         p_end = end;
1202
1203                 /* Found completely overlapping range */
1204                 if (p_start == start && p_end == end) {
1205                         mem->ranges[i].start = 0;
1206                         mem->ranges[i].end = 0;
1207                         if (i < mem->nr_ranges - 1) {
1208                                 /* Shift rest of the ranges to left */
1209                                 for (j = i; j < mem->nr_ranges - 1; j++) {
1210                                         mem->ranges[j].start =
1211                                                 mem->ranges[j+1].start;
1212                                         mem->ranges[j].end =
1213                                                         mem->ranges[j+1].end;
1214                                 }
1215
1216                                 /*
1217                                  * Continue to check if there are another overlapping ranges
1218                                  * from the current position because of shifting the above
1219                                  * mem ranges.
1220                                  */
1221                                 i--;
1222                                 mem->nr_ranges--;
1223                                 continue;
1224                         }
1225                         mem->nr_ranges--;
1226                         return 0;
1227                 }
1228
1229                 if (p_start > start && p_end < end) {
1230                         /* Split original range */
1231                         mem->ranges[i].end = p_start - 1;
1232                         temp_range.start = p_end + 1;
1233                         temp_range.end = end;
1234                 } else if (p_start != start)
1235                         mem->ranges[i].end = p_start - 1;
1236                 else
1237                         mem->ranges[i].start = p_end + 1;
1238                 break;
1239         }
1240
1241         /* If a split happened, add the split to array */
1242         if (!temp_range.end)
1243                 return 0;
1244
1245         /* Split happened */
1246         if (i == mem->max_nr_ranges - 1)
1247                 return -ENOMEM;
1248
1249         /* Location where new range should go */
1250         j = i + 1;
1251         if (j < mem->nr_ranges) {
1252                 /* Move over all ranges one slot towards the end */
1253                 for (i = mem->nr_ranges - 1; i >= j; i--)
1254                         mem->ranges[i + 1] = mem->ranges[i];
1255         }
1256
1257         mem->ranges[j].start = temp_range.start;
1258         mem->ranges[j].end = temp_range.end;
1259         mem->nr_ranges++;
1260         return 0;
1261 }
1262
1263 int crash_prepare_elf64_headers(struct crash_mem *mem, int kernel_map,
1264                           void **addr, unsigned long *sz)
1265 {
1266         Elf64_Ehdr *ehdr;
1267         Elf64_Phdr *phdr;
1268         unsigned long nr_cpus = num_possible_cpus(), nr_phdr, elf_sz;
1269         unsigned char *buf;
1270         unsigned int cpu, i;
1271         unsigned long long notes_addr;
1272         unsigned long mstart, mend;
1273
1274         /* extra phdr for vmcoreinfo ELF note */
1275         nr_phdr = nr_cpus + 1;
1276         nr_phdr += mem->nr_ranges;
1277
1278         /*
1279          * kexec-tools creates an extra PT_LOAD phdr for kernel text mapping
1280          * area (for example, ffffffff80000000 - ffffffffa0000000 on x86_64).
1281          * I think this is required by tools like gdb. So same physical
1282          * memory will be mapped in two ELF headers. One will contain kernel
1283          * text virtual addresses and other will have __va(physical) addresses.
1284          */
1285
1286         nr_phdr++;
1287         elf_sz = sizeof(Elf64_Ehdr) + nr_phdr * sizeof(Elf64_Phdr);
1288         elf_sz = ALIGN(elf_sz, ELF_CORE_HEADER_ALIGN);
1289
1290         buf = vzalloc(elf_sz);
1291         if (!buf)
1292                 return -ENOMEM;
1293
1294         ehdr = (Elf64_Ehdr *)buf;
1295         phdr = (Elf64_Phdr *)(ehdr + 1);
1296         memcpy(ehdr->e_ident, ELFMAG, SELFMAG);
1297         ehdr->e_ident[EI_CLASS] = ELFCLASS64;
1298         ehdr->e_ident[EI_DATA] = ELFDATA2LSB;
1299         ehdr->e_ident[EI_VERSION] = EV_CURRENT;
1300         ehdr->e_ident[EI_OSABI] = ELF_OSABI;
1301         memset(ehdr->e_ident + EI_PAD, 0, EI_NIDENT - EI_PAD);
1302         ehdr->e_type = ET_CORE;
1303         ehdr->e_machine = ELF_ARCH;
1304         ehdr->e_version = EV_CURRENT;
1305         ehdr->e_phoff = sizeof(Elf64_Ehdr);
1306         ehdr->e_ehsize = sizeof(Elf64_Ehdr);
1307         ehdr->e_phentsize = sizeof(Elf64_Phdr);
1308
1309         /* Prepare one phdr of type PT_NOTE for each present CPU */
1310         for_each_present_cpu(cpu) {
1311                 phdr->p_type = PT_NOTE;
1312                 notes_addr = per_cpu_ptr_to_phys(per_cpu_ptr(crash_notes, cpu));
1313                 phdr->p_offset = phdr->p_paddr = notes_addr;
1314                 phdr->p_filesz = phdr->p_memsz = sizeof(note_buf_t);
1315                 (ehdr->e_phnum)++;
1316                 phdr++;
1317         }
1318
1319         /* Prepare one PT_NOTE header for vmcoreinfo */
1320         phdr->p_type = PT_NOTE;
1321         phdr->p_offset = phdr->p_paddr = paddr_vmcoreinfo_note();
1322         phdr->p_filesz = phdr->p_memsz = VMCOREINFO_NOTE_SIZE;
1323         (ehdr->e_phnum)++;
1324         phdr++;
1325
1326         /* Prepare PT_LOAD type program header for kernel text region */
1327         if (kernel_map) {
1328                 phdr->p_type = PT_LOAD;
1329                 phdr->p_flags = PF_R|PF_W|PF_X;
1330                 phdr->p_vaddr = (unsigned long) _text;
1331                 phdr->p_filesz = phdr->p_memsz = _end - _text;
1332                 phdr->p_offset = phdr->p_paddr = __pa_symbol(_text);
1333                 ehdr->e_phnum++;
1334                 phdr++;
1335         }
1336
1337         /* Go through all the ranges in mem->ranges[] and prepare phdr */
1338         for (i = 0; i < mem->nr_ranges; i++) {
1339                 mstart = mem->ranges[i].start;
1340                 mend = mem->ranges[i].end;
1341
1342                 phdr->p_type = PT_LOAD;
1343                 phdr->p_flags = PF_R|PF_W|PF_X;
1344                 phdr->p_offset  = mstart;
1345
1346                 phdr->p_paddr = mstart;
1347                 phdr->p_vaddr = (unsigned long) __va(mstart);
1348                 phdr->p_filesz = phdr->p_memsz = mend - mstart + 1;
1349                 phdr->p_align = 0;
1350                 ehdr->e_phnum++;
1351                 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",
1352                         phdr, phdr->p_vaddr, phdr->p_paddr, phdr->p_filesz,
1353                         ehdr->e_phnum, phdr->p_offset);
1354                 phdr++;
1355         }
1356
1357         *addr = buf;
1358         *sz = elf_sz;
1359         return 0;
1360 }