kernel/kexec_file.c: remove some duplicated includes
[muen/linux.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/mutex.h>
20 #include <linux/list.h>
21 #include <linux/fs.h>
22 #include <linux/ima.h>
23 #include <crypto/hash.h>
24 #include <crypto/sha.h>
25 #include <linux/elf.h>
26 #include <linux/elfcore.h>
27 #include <linux/kernel.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 static 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_VERIFY_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         /* See if architecture has anything to cleanup post load */
170         arch_kimage_file_post_load_cleanup(image);
171
172         /*
173          * Above call should have called into bootloader to free up
174          * any data stored in kimage->image_loader_data. It should
175          * be ok now to free it up.
176          */
177         kfree(image->image_loader_data);
178         image->image_loader_data = NULL;
179 }
180
181 /*
182  * In file mode list of segments is prepared by kernel. Copy relevant
183  * data from user space, do error checking, prepare segment list
184  */
185 static int
186 kimage_file_prepare_segments(struct kimage *image, int kernel_fd, int initrd_fd,
187                              const char __user *cmdline_ptr,
188                              unsigned long cmdline_len, unsigned flags)
189 {
190         int ret = 0;
191         void *ldata;
192         loff_t size;
193
194         ret = kernel_read_file_from_fd(kernel_fd, &image->kernel_buf,
195                                        &size, INT_MAX, READING_KEXEC_IMAGE);
196         if (ret)
197                 return ret;
198         image->kernel_buf_len = size;
199
200         /* IMA needs to pass the measurement list to the next kernel. */
201         ima_add_kexec_buffer(image);
202
203         /* Call arch image probe handlers */
204         ret = arch_kexec_kernel_image_probe(image, image->kernel_buf,
205                                             image->kernel_buf_len);
206         if (ret)
207                 goto out;
208
209 #ifdef CONFIG_KEXEC_VERIFY_SIG
210         ret = arch_kexec_kernel_verify_sig(image, image->kernel_buf,
211                                            image->kernel_buf_len);
212         if (ret) {
213                 pr_debug("kernel signature verification failed.\n");
214                 goto out;
215         }
216         pr_debug("kernel signature verification successful.\n");
217 #endif
218         /* It is possible that there no initramfs is being loaded */
219         if (!(flags & KEXEC_FILE_NO_INITRAMFS)) {
220                 ret = kernel_read_file_from_fd(initrd_fd, &image->initrd_buf,
221                                                &size, INT_MAX,
222                                                READING_KEXEC_INITRAMFS);
223                 if (ret)
224                         goto out;
225                 image->initrd_buf_len = size;
226         }
227
228         if (cmdline_len) {
229                 image->cmdline_buf = memdup_user(cmdline_ptr, cmdline_len);
230                 if (IS_ERR(image->cmdline_buf)) {
231                         ret = PTR_ERR(image->cmdline_buf);
232                         image->cmdline_buf = NULL;
233                         goto out;
234                 }
235
236                 image->cmdline_buf_len = cmdline_len;
237
238                 /* command line should be a string with last byte null */
239                 if (image->cmdline_buf[cmdline_len - 1] != '\0') {
240                         ret = -EINVAL;
241                         goto out;
242                 }
243         }
244
245         /* Call arch image load handlers */
246         ldata = arch_kexec_kernel_image_load(image);
247
248         if (IS_ERR(ldata)) {
249                 ret = PTR_ERR(ldata);
250                 goto out;
251         }
252
253         image->image_loader_data = ldata;
254 out:
255         /* In case of error, free up all allocated memory in this function */
256         if (ret)
257                 kimage_file_post_load_cleanup(image);
258         return ret;
259 }
260
261 static int
262 kimage_file_alloc_init(struct kimage **rimage, int kernel_fd,
263                        int initrd_fd, const char __user *cmdline_ptr,
264                        unsigned long cmdline_len, unsigned long flags)
265 {
266         int ret;
267         struct kimage *image;
268         bool kexec_on_panic = flags & KEXEC_FILE_ON_CRASH;
269
270         image = do_kimage_alloc_init();
271         if (!image)
272                 return -ENOMEM;
273
274         image->file_mode = 1;
275
276         if (kexec_on_panic) {
277                 /* Enable special crash kernel control page alloc policy. */
278                 image->control_page = crashk_res.start;
279                 image->type = KEXEC_TYPE_CRASH;
280         }
281
282         ret = kimage_file_prepare_segments(image, kernel_fd, initrd_fd,
283                                            cmdline_ptr, cmdline_len, flags);
284         if (ret)
285                 goto out_free_image;
286
287         ret = sanity_check_segment_list(image);
288         if (ret)
289                 goto out_free_post_load_bufs;
290
291         ret = -ENOMEM;
292         image->control_code_page = kimage_alloc_control_pages(image,
293                                            get_order(KEXEC_CONTROL_PAGE_SIZE));
294         if (!image->control_code_page) {
295                 pr_err("Could not allocate control_code_buffer\n");
296                 goto out_free_post_load_bufs;
297         }
298
299         if (!kexec_on_panic) {
300                 image->swap_page = kimage_alloc_control_pages(image, 0);
301                 if (!image->swap_page) {
302                         pr_err("Could not allocate swap buffer\n");
303                         goto out_free_control_pages;
304                 }
305         }
306
307         *rimage = image;
308         return 0;
309 out_free_control_pages:
310         kimage_free_page_list(&image->control_pages);
311 out_free_post_load_bufs:
312         kimage_file_post_load_cleanup(image);
313 out_free_image:
314         kfree(image);
315         return ret;
316 }
317
318 SYSCALL_DEFINE5(kexec_file_load, int, kernel_fd, int, initrd_fd,
319                 unsigned long, cmdline_len, const char __user *, cmdline_ptr,
320                 unsigned long, flags)
321 {
322         int ret = 0, i;
323         struct kimage **dest_image, *image;
324
325         /* We only trust the superuser with rebooting the system. */
326         if (!capable(CAP_SYS_BOOT) || kexec_load_disabled)
327                 return -EPERM;
328
329         /* Make sure we have a legal set of flags */
330         if (flags != (flags & KEXEC_FILE_FLAGS))
331                 return -EINVAL;
332
333         image = NULL;
334
335         if (!mutex_trylock(&kexec_mutex))
336                 return -EBUSY;
337
338         dest_image = &kexec_image;
339         if (flags & KEXEC_FILE_ON_CRASH) {
340                 dest_image = &kexec_crash_image;
341                 if (kexec_crash_image)
342                         arch_kexec_unprotect_crashkres();
343         }
344
345         if (flags & KEXEC_FILE_UNLOAD)
346                 goto exchange;
347
348         /*
349          * In case of crash, new kernel gets loaded in reserved region. It is
350          * same memory where old crash kernel might be loaded. Free any
351          * current crash dump kernel before we corrupt it.
352          */
353         if (flags & KEXEC_FILE_ON_CRASH)
354                 kimage_free(xchg(&kexec_crash_image, NULL));
355
356         ret = kimage_file_alloc_init(&image, kernel_fd, initrd_fd, cmdline_ptr,
357                                      cmdline_len, flags);
358         if (ret)
359                 goto out;
360
361         ret = machine_kexec_prepare(image);
362         if (ret)
363                 goto out;
364
365         /*
366          * Some architecture(like S390) may touch the crash memory before
367          * machine_kexec_prepare(), we must copy vmcoreinfo data after it.
368          */
369         ret = kimage_crash_copy_vmcoreinfo(image);
370         if (ret)
371                 goto out;
372
373         ret = kexec_calculate_store_digests(image);
374         if (ret)
375                 goto out;
376
377         for (i = 0; i < image->nr_segments; i++) {
378                 struct kexec_segment *ksegment;
379
380                 ksegment = &image->segment[i];
381                 pr_debug("Loading segment %d: buf=0x%p bufsz=0x%zx mem=0x%lx memsz=0x%zx\n",
382                          i, ksegment->buf, ksegment->bufsz, ksegment->mem,
383                          ksegment->memsz);
384
385                 ret = kimage_load_segment(image, &image->segment[i]);
386                 if (ret)
387                         goto out;
388         }
389
390         kimage_terminate(image);
391
392         /*
393          * Free up any temporary buffers allocated which are not needed
394          * after image has been loaded
395          */
396         kimage_file_post_load_cleanup(image);
397 exchange:
398         image = xchg(dest_image, image);
399 out:
400         if ((flags & KEXEC_FILE_ON_CRASH) && kexec_crash_image)
401                 arch_kexec_protect_crashkres();
402
403         mutex_unlock(&kexec_mutex);
404         kimage_free(image);
405         return ret;
406 }
407
408 static int locate_mem_hole_top_down(unsigned long start, unsigned long end,
409                                     struct kexec_buf *kbuf)
410 {
411         struct kimage *image = kbuf->image;
412         unsigned long temp_start, temp_end;
413
414         temp_end = min(end, kbuf->buf_max);
415         temp_start = temp_end - kbuf->memsz;
416
417         do {
418                 /* align down start */
419                 temp_start = temp_start & (~(kbuf->buf_align - 1));
420
421                 if (temp_start < start || temp_start < kbuf->buf_min)
422                         return 0;
423
424                 temp_end = temp_start + kbuf->memsz - 1;
425
426                 /*
427                  * Make sure this does not conflict with any of existing
428                  * segments
429                  */
430                 if (kimage_is_destination_range(image, temp_start, temp_end)) {
431                         temp_start = temp_start - PAGE_SIZE;
432                         continue;
433                 }
434
435                 /* We found a suitable memory range */
436                 break;
437         } while (1);
438
439         /* If we are here, we found a suitable memory range */
440         kbuf->mem = temp_start;
441
442         /* Success, stop navigating through remaining System RAM ranges */
443         return 1;
444 }
445
446 static int locate_mem_hole_bottom_up(unsigned long start, unsigned long end,
447                                      struct kexec_buf *kbuf)
448 {
449         struct kimage *image = kbuf->image;
450         unsigned long temp_start, temp_end;
451
452         temp_start = max(start, kbuf->buf_min);
453
454         do {
455                 temp_start = ALIGN(temp_start, kbuf->buf_align);
456                 temp_end = temp_start + kbuf->memsz - 1;
457
458                 if (temp_end > end || temp_end > kbuf->buf_max)
459                         return 0;
460                 /*
461                  * Make sure this does not conflict with any of existing
462                  * segments
463                  */
464                 if (kimage_is_destination_range(image, temp_start, temp_end)) {
465                         temp_start = temp_start + PAGE_SIZE;
466                         continue;
467                 }
468
469                 /* We found a suitable memory range */
470                 break;
471         } while (1);
472
473         /* If we are here, we found a suitable memory range */
474         kbuf->mem = temp_start;
475
476         /* Success, stop navigating through remaining System RAM ranges */
477         return 1;
478 }
479
480 static int locate_mem_hole_callback(struct resource *res, void *arg)
481 {
482         struct kexec_buf *kbuf = (struct kexec_buf *)arg;
483         u64 start = res->start, end = res->end;
484         unsigned long sz = end - start + 1;
485
486         /* Returning 0 will take to next memory range */
487         if (sz < kbuf->memsz)
488                 return 0;
489
490         if (end < kbuf->buf_min || start > kbuf->buf_max)
491                 return 0;
492
493         /*
494          * Allocate memory top down with-in ram range. Otherwise bottom up
495          * allocation.
496          */
497         if (kbuf->top_down)
498                 return locate_mem_hole_top_down(start, end, kbuf);
499         return locate_mem_hole_bottom_up(start, end, kbuf);
500 }
501
502 /**
503  * arch_kexec_walk_mem - call func(data) on free memory regions
504  * @kbuf:       Context info for the search. Also passed to @func.
505  * @func:       Function to call for each memory region.
506  *
507  * Return: The memory walk will stop when func returns a non-zero value
508  * and that value will be returned. If all free regions are visited without
509  * func returning non-zero, then zero will be returned.
510  */
511 int __weak arch_kexec_walk_mem(struct kexec_buf *kbuf,
512                                int (*func)(struct resource *, void *))
513 {
514         if (kbuf->image->type == KEXEC_TYPE_CRASH)
515                 return walk_iomem_res_desc(crashk_res.desc,
516                                            IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY,
517                                            crashk_res.start, crashk_res.end,
518                                            kbuf, func);
519         else
520                 return walk_system_ram_res(0, ULONG_MAX, kbuf, func);
521 }
522
523 /**
524  * kexec_locate_mem_hole - find free memory for the purgatory or the next kernel
525  * @kbuf:       Parameters for the memory search.
526  *
527  * On success, kbuf->mem will have the start address of the memory region found.
528  *
529  * Return: 0 on success, negative errno on error.
530  */
531 int kexec_locate_mem_hole(struct kexec_buf *kbuf)
532 {
533         int ret;
534
535         ret = arch_kexec_walk_mem(kbuf, locate_mem_hole_callback);
536
537         return ret == 1 ? 0 : -EADDRNOTAVAIL;
538 }
539
540 /**
541  * kexec_add_buffer - place a buffer in a kexec segment
542  * @kbuf:       Buffer contents and memory parameters.
543  *
544  * This function assumes that kexec_mutex is held.
545  * On successful return, @kbuf->mem will have the physical address of
546  * the buffer in memory.
547  *
548  * Return: 0 on success, negative errno on error.
549  */
550 int kexec_add_buffer(struct kexec_buf *kbuf)
551 {
552
553         struct kexec_segment *ksegment;
554         int ret;
555
556         /* Currently adding segment this way is allowed only in file mode */
557         if (!kbuf->image->file_mode)
558                 return -EINVAL;
559
560         if (kbuf->image->nr_segments >= KEXEC_SEGMENT_MAX)
561                 return -EINVAL;
562
563         /*
564          * Make sure we are not trying to add buffer after allocating
565          * control pages. All segments need to be placed first before
566          * any control pages are allocated. As control page allocation
567          * logic goes through list of segments to make sure there are
568          * no destination overlaps.
569          */
570         if (!list_empty(&kbuf->image->control_pages)) {
571                 WARN_ON(1);
572                 return -EINVAL;
573         }
574
575         /* Ensure minimum alignment needed for segments. */
576         kbuf->memsz = ALIGN(kbuf->memsz, PAGE_SIZE);
577         kbuf->buf_align = max(kbuf->buf_align, PAGE_SIZE);
578
579         /* Walk the RAM ranges and allocate a suitable range for the buffer */
580         ret = kexec_locate_mem_hole(kbuf);
581         if (ret)
582                 return ret;
583
584         /* Found a suitable memory range */
585         ksegment = &kbuf->image->segment[kbuf->image->nr_segments];
586         ksegment->kbuf = kbuf->buffer;
587         ksegment->bufsz = kbuf->bufsz;
588         ksegment->mem = kbuf->mem;
589         ksegment->memsz = kbuf->memsz;
590         kbuf->image->nr_segments++;
591         return 0;
592 }
593
594 /* Calculate and store the digest of segments */
595 static int kexec_calculate_store_digests(struct kimage *image)
596 {
597         struct crypto_shash *tfm;
598         struct shash_desc *desc;
599         int ret = 0, i, j, zero_buf_sz, sha_region_sz;
600         size_t desc_size, nullsz;
601         char *digest;
602         void *zero_buf;
603         struct kexec_sha_region *sha_regions;
604         struct purgatory_info *pi = &image->purgatory_info;
605
606         if (!IS_ENABLED(CONFIG_ARCH_HAS_KEXEC_PURGATORY))
607                 return 0;
608
609         zero_buf = __va(page_to_pfn(ZERO_PAGE(0)) << PAGE_SHIFT);
610         zero_buf_sz = PAGE_SIZE;
611
612         tfm = crypto_alloc_shash("sha256", 0, 0);
613         if (IS_ERR(tfm)) {
614                 ret = PTR_ERR(tfm);
615                 goto out;
616         }
617
618         desc_size = crypto_shash_descsize(tfm) + sizeof(*desc);
619         desc = kzalloc(desc_size, GFP_KERNEL);
620         if (!desc) {
621                 ret = -ENOMEM;
622                 goto out_free_tfm;
623         }
624
625         sha_region_sz = KEXEC_SEGMENT_MAX * sizeof(struct kexec_sha_region);
626         sha_regions = vzalloc(sha_region_sz);
627         if (!sha_regions)
628                 goto out_free_desc;
629
630         desc->tfm   = tfm;
631         desc->flags = 0;
632
633         ret = crypto_shash_init(desc);
634         if (ret < 0)
635                 goto out_free_sha_regions;
636
637         digest = kzalloc(SHA256_DIGEST_SIZE, GFP_KERNEL);
638         if (!digest) {
639                 ret = -ENOMEM;
640                 goto out_free_sha_regions;
641         }
642
643         for (j = i = 0; i < image->nr_segments; i++) {
644                 struct kexec_segment *ksegment;
645
646                 ksegment = &image->segment[i];
647                 /*
648                  * Skip purgatory as it will be modified once we put digest
649                  * info in purgatory.
650                  */
651                 if (ksegment->kbuf == pi->purgatory_buf)
652                         continue;
653
654                 ret = crypto_shash_update(desc, ksegment->kbuf,
655                                           ksegment->bufsz);
656                 if (ret)
657                         break;
658
659                 /*
660                  * Assume rest of the buffer is filled with zero and
661                  * update digest accordingly.
662                  */
663                 nullsz = ksegment->memsz - ksegment->bufsz;
664                 while (nullsz) {
665                         unsigned long bytes = nullsz;
666
667                         if (bytes > zero_buf_sz)
668                                 bytes = zero_buf_sz;
669                         ret = crypto_shash_update(desc, zero_buf, bytes);
670                         if (ret)
671                                 break;
672                         nullsz -= bytes;
673                 }
674
675                 if (ret)
676                         break;
677
678                 sha_regions[j].start = ksegment->mem;
679                 sha_regions[j].len = ksegment->memsz;
680                 j++;
681         }
682
683         if (!ret) {
684                 ret = crypto_shash_final(desc, digest);
685                 if (ret)
686                         goto out_free_digest;
687                 ret = kexec_purgatory_get_set_symbol(image, "purgatory_sha_regions",
688                                                      sha_regions, sha_region_sz, 0);
689                 if (ret)
690                         goto out_free_digest;
691
692                 ret = kexec_purgatory_get_set_symbol(image, "purgatory_sha256_digest",
693                                                      digest, SHA256_DIGEST_SIZE, 0);
694                 if (ret)
695                         goto out_free_digest;
696         }
697
698 out_free_digest:
699         kfree(digest);
700 out_free_sha_regions:
701         vfree(sha_regions);
702 out_free_desc:
703         kfree(desc);
704 out_free_tfm:
705         kfree(tfm);
706 out:
707         return ret;
708 }
709
710 #ifdef CONFIG_ARCH_HAS_KEXEC_PURGATORY
711 /*
712  * kexec_purgatory_setup_kbuf - prepare buffer to load purgatory.
713  * @pi:         Purgatory to be loaded.
714  * @kbuf:       Buffer to setup.
715  *
716  * Allocates the memory needed for the buffer. Caller is responsible to free
717  * the memory after use.
718  *
719  * Return: 0 on success, negative errno on error.
720  */
721 static int kexec_purgatory_setup_kbuf(struct purgatory_info *pi,
722                                       struct kexec_buf *kbuf)
723 {
724         const Elf_Shdr *sechdrs;
725         unsigned long bss_align;
726         unsigned long bss_sz;
727         unsigned long align;
728         int i, ret;
729
730         sechdrs = (void *)pi->ehdr + pi->ehdr->e_shoff;
731         kbuf->buf_align = bss_align = 1;
732         kbuf->bufsz = bss_sz = 0;
733
734         for (i = 0; i < pi->ehdr->e_shnum; i++) {
735                 if (!(sechdrs[i].sh_flags & SHF_ALLOC))
736                         continue;
737
738                 align = sechdrs[i].sh_addralign;
739                 if (sechdrs[i].sh_type != SHT_NOBITS) {
740                         if (kbuf->buf_align < align)
741                                 kbuf->buf_align = align;
742                         kbuf->bufsz = ALIGN(kbuf->bufsz, align);
743                         kbuf->bufsz += sechdrs[i].sh_size;
744                 } else {
745                         if (bss_align < align)
746                                 bss_align = align;
747                         bss_sz = ALIGN(bss_sz, align);
748                         bss_sz += sechdrs[i].sh_size;
749                 }
750         }
751         kbuf->bufsz = ALIGN(kbuf->bufsz, bss_align);
752         kbuf->memsz = kbuf->bufsz + bss_sz;
753         if (kbuf->buf_align < bss_align)
754                 kbuf->buf_align = bss_align;
755
756         kbuf->buffer = vzalloc(kbuf->bufsz);
757         if (!kbuf->buffer)
758                 return -ENOMEM;
759         pi->purgatory_buf = kbuf->buffer;
760
761         ret = kexec_add_buffer(kbuf);
762         if (ret)
763                 goto out;
764
765         return 0;
766 out:
767         vfree(pi->purgatory_buf);
768         pi->purgatory_buf = NULL;
769         return ret;
770 }
771
772 /*
773  * kexec_purgatory_setup_sechdrs - prepares the pi->sechdrs buffer.
774  * @pi:         Purgatory to be loaded.
775  * @kbuf:       Buffer prepared to store purgatory.
776  *
777  * Allocates the memory needed for the buffer. Caller is responsible to free
778  * the memory after use.
779  *
780  * Return: 0 on success, negative errno on error.
781  */
782 static int kexec_purgatory_setup_sechdrs(struct purgatory_info *pi,
783                                          struct kexec_buf *kbuf)
784 {
785         unsigned long bss_addr;
786         unsigned long offset;
787         Elf_Shdr *sechdrs;
788         int i;
789
790         /*
791          * The section headers in kexec_purgatory are read-only. In order to
792          * have them modifiable make a temporary copy.
793          */
794         sechdrs = vzalloc(array_size(sizeof(Elf_Shdr), pi->ehdr->e_shnum));
795         if (!sechdrs)
796                 return -ENOMEM;
797         memcpy(sechdrs, (void *)pi->ehdr + pi->ehdr->e_shoff,
798                pi->ehdr->e_shnum * sizeof(Elf_Shdr));
799         pi->sechdrs = sechdrs;
800
801         offset = 0;
802         bss_addr = kbuf->mem + kbuf->bufsz;
803         kbuf->image->start = pi->ehdr->e_entry;
804
805         for (i = 0; i < pi->ehdr->e_shnum; i++) {
806                 unsigned long align;
807                 void *src, *dst;
808
809                 if (!(sechdrs[i].sh_flags & SHF_ALLOC))
810                         continue;
811
812                 align = sechdrs[i].sh_addralign;
813                 if (sechdrs[i].sh_type == SHT_NOBITS) {
814                         bss_addr = ALIGN(bss_addr, align);
815                         sechdrs[i].sh_addr = bss_addr;
816                         bss_addr += sechdrs[i].sh_size;
817                         continue;
818                 }
819
820                 offset = ALIGN(offset, align);
821                 if (sechdrs[i].sh_flags & SHF_EXECINSTR &&
822                     pi->ehdr->e_entry >= sechdrs[i].sh_addr &&
823                     pi->ehdr->e_entry < (sechdrs[i].sh_addr
824                                          + sechdrs[i].sh_size)) {
825                         kbuf->image->start -= sechdrs[i].sh_addr;
826                         kbuf->image->start += kbuf->mem + offset;
827                 }
828
829                 src = (void *)pi->ehdr + sechdrs[i].sh_offset;
830                 dst = pi->purgatory_buf + offset;
831                 memcpy(dst, src, sechdrs[i].sh_size);
832
833                 sechdrs[i].sh_addr = kbuf->mem + offset;
834                 sechdrs[i].sh_offset = offset;
835                 offset += sechdrs[i].sh_size;
836         }
837
838         return 0;
839 }
840
841 static int kexec_apply_relocations(struct kimage *image)
842 {
843         int i, ret;
844         struct purgatory_info *pi = &image->purgatory_info;
845         const Elf_Shdr *sechdrs;
846
847         sechdrs = (void *)pi->ehdr + pi->ehdr->e_shoff;
848
849         for (i = 0; i < pi->ehdr->e_shnum; i++) {
850                 const Elf_Shdr *relsec;
851                 const Elf_Shdr *symtab;
852                 Elf_Shdr *section;
853
854                 relsec = sechdrs + i;
855
856                 if (relsec->sh_type != SHT_RELA &&
857                     relsec->sh_type != SHT_REL)
858                         continue;
859
860                 /*
861                  * For section of type SHT_RELA/SHT_REL,
862                  * ->sh_link contains section header index of associated
863                  * symbol table. And ->sh_info contains section header
864                  * index of section to which relocations apply.
865                  */
866                 if (relsec->sh_info >= pi->ehdr->e_shnum ||
867                     relsec->sh_link >= pi->ehdr->e_shnum)
868                         return -ENOEXEC;
869
870                 section = pi->sechdrs + relsec->sh_info;
871                 symtab = sechdrs + relsec->sh_link;
872
873                 if (!(section->sh_flags & SHF_ALLOC))
874                         continue;
875
876                 /*
877                  * symtab->sh_link contain section header index of associated
878                  * string table.
879                  */
880                 if (symtab->sh_link >= pi->ehdr->e_shnum)
881                         /* Invalid section number? */
882                         continue;
883
884                 /*
885                  * Respective architecture needs to provide support for applying
886                  * relocations of type SHT_RELA/SHT_REL.
887                  */
888                 if (relsec->sh_type == SHT_RELA)
889                         ret = arch_kexec_apply_relocations_add(pi, section,
890                                                                relsec, symtab);
891                 else if (relsec->sh_type == SHT_REL)
892                         ret = arch_kexec_apply_relocations(pi, section,
893                                                            relsec, symtab);
894                 if (ret)
895                         return ret;
896         }
897
898         return 0;
899 }
900
901 /*
902  * kexec_load_purgatory - Load and relocate the purgatory object.
903  * @image:      Image to add the purgatory to.
904  * @kbuf:       Memory parameters to use.
905  *
906  * Allocates the memory needed for image->purgatory_info.sechdrs and
907  * image->purgatory_info.purgatory_buf/kbuf->buffer. Caller is responsible
908  * to free the memory after use.
909  *
910  * Return: 0 on success, negative errno on error.
911  */
912 int kexec_load_purgatory(struct kimage *image, struct kexec_buf *kbuf)
913 {
914         struct purgatory_info *pi = &image->purgatory_info;
915         int ret;
916
917         if (kexec_purgatory_size <= 0)
918                 return -EINVAL;
919
920         pi->ehdr = (const Elf_Ehdr *)kexec_purgatory;
921
922         ret = kexec_purgatory_setup_kbuf(pi, kbuf);
923         if (ret)
924                 return ret;
925
926         ret = kexec_purgatory_setup_sechdrs(pi, kbuf);
927         if (ret)
928                 goto out_free_kbuf;
929
930         ret = kexec_apply_relocations(image);
931         if (ret)
932                 goto out;
933
934         return 0;
935 out:
936         vfree(pi->sechdrs);
937         pi->sechdrs = NULL;
938 out_free_kbuf:
939         vfree(pi->purgatory_buf);
940         pi->purgatory_buf = NULL;
941         return ret;
942 }
943
944 /*
945  * kexec_purgatory_find_symbol - find a symbol in the purgatory
946  * @pi:         Purgatory to search in.
947  * @name:       Name of the symbol.
948  *
949  * Return: pointer to symbol in read-only symtab on success, NULL on error.
950  */
951 static const Elf_Sym *kexec_purgatory_find_symbol(struct purgatory_info *pi,
952                                                   const char *name)
953 {
954         const Elf_Shdr *sechdrs;
955         const Elf_Ehdr *ehdr;
956         const Elf_Sym *syms;
957         const char *strtab;
958         int i, k;
959
960         if (!pi->ehdr)
961                 return NULL;
962
963         ehdr = pi->ehdr;
964         sechdrs = (void *)ehdr + ehdr->e_shoff;
965
966         for (i = 0; i < ehdr->e_shnum; i++) {
967                 if (sechdrs[i].sh_type != SHT_SYMTAB)
968                         continue;
969
970                 if (sechdrs[i].sh_link >= ehdr->e_shnum)
971                         /* Invalid strtab section number */
972                         continue;
973                 strtab = (void *)ehdr + sechdrs[sechdrs[i].sh_link].sh_offset;
974                 syms = (void *)ehdr + sechdrs[i].sh_offset;
975
976                 /* Go through symbols for a match */
977                 for (k = 0; k < sechdrs[i].sh_size/sizeof(Elf_Sym); k++) {
978                         if (ELF_ST_BIND(syms[k].st_info) != STB_GLOBAL)
979                                 continue;
980
981                         if (strcmp(strtab + syms[k].st_name, name) != 0)
982                                 continue;
983
984                         if (syms[k].st_shndx == SHN_UNDEF ||
985                             syms[k].st_shndx >= ehdr->e_shnum) {
986                                 pr_debug("Symbol: %s has bad section index %d.\n",
987                                                 name, syms[k].st_shndx);
988                                 return NULL;
989                         }
990
991                         /* Found the symbol we are looking for */
992                         return &syms[k];
993                 }
994         }
995
996         return NULL;
997 }
998
999 void *kexec_purgatory_get_symbol_addr(struct kimage *image, const char *name)
1000 {
1001         struct purgatory_info *pi = &image->purgatory_info;
1002         const Elf_Sym *sym;
1003         Elf_Shdr *sechdr;
1004
1005         sym = kexec_purgatory_find_symbol(pi, name);
1006         if (!sym)
1007                 return ERR_PTR(-EINVAL);
1008
1009         sechdr = &pi->sechdrs[sym->st_shndx];
1010
1011         /*
1012          * Returns the address where symbol will finally be loaded after
1013          * kexec_load_segment()
1014          */
1015         return (void *)(sechdr->sh_addr + sym->st_value);
1016 }
1017
1018 /*
1019  * Get or set value of a symbol. If "get_value" is true, symbol value is
1020  * returned in buf otherwise symbol value is set based on value in buf.
1021  */
1022 int kexec_purgatory_get_set_symbol(struct kimage *image, const char *name,
1023                                    void *buf, unsigned int size, bool get_value)
1024 {
1025         struct purgatory_info *pi = &image->purgatory_info;
1026         const Elf_Sym *sym;
1027         Elf_Shdr *sec;
1028         char *sym_buf;
1029
1030         sym = kexec_purgatory_find_symbol(pi, name);
1031         if (!sym)
1032                 return -EINVAL;
1033
1034         if (sym->st_size != size) {
1035                 pr_err("symbol %s size mismatch: expected %lu actual %u\n",
1036                        name, (unsigned long)sym->st_size, size);
1037                 return -EINVAL;
1038         }
1039
1040         sec = pi->sechdrs + sym->st_shndx;
1041
1042         if (sec->sh_type == SHT_NOBITS) {
1043                 pr_err("symbol %s is in a bss section. Cannot %s\n", name,
1044                        get_value ? "get" : "set");
1045                 return -EINVAL;
1046         }
1047
1048         sym_buf = (char *)pi->purgatory_buf + sec->sh_offset + sym->st_value;
1049
1050         if (get_value)
1051                 memcpy((void *)buf, sym_buf, size);
1052         else
1053                 memcpy((void *)sym_buf, buf, size);
1054
1055         return 0;
1056 }
1057 #endif /* CONFIG_ARCH_HAS_KEXEC_PURGATORY */
1058
1059 int crash_exclude_mem_range(struct crash_mem *mem,
1060                             unsigned long long mstart, unsigned long long mend)
1061 {
1062         int i, j;
1063         unsigned long long start, end;
1064         struct crash_mem_range temp_range = {0, 0};
1065
1066         for (i = 0; i < mem->nr_ranges; i++) {
1067                 start = mem->ranges[i].start;
1068                 end = mem->ranges[i].end;
1069
1070                 if (mstart > end || mend < start)
1071                         continue;
1072
1073                 /* Truncate any area outside of range */
1074                 if (mstart < start)
1075                         mstart = start;
1076                 if (mend > end)
1077                         mend = end;
1078
1079                 /* Found completely overlapping range */
1080                 if (mstart == start && mend == end) {
1081                         mem->ranges[i].start = 0;
1082                         mem->ranges[i].end = 0;
1083                         if (i < mem->nr_ranges - 1) {
1084                                 /* Shift rest of the ranges to left */
1085                                 for (j = i; j < mem->nr_ranges - 1; j++) {
1086                                         mem->ranges[j].start =
1087                                                 mem->ranges[j+1].start;
1088                                         mem->ranges[j].end =
1089                                                         mem->ranges[j+1].end;
1090                                 }
1091                         }
1092                         mem->nr_ranges--;
1093                         return 0;
1094                 }
1095
1096                 if (mstart > start && mend < end) {
1097                         /* Split original range */
1098                         mem->ranges[i].end = mstart - 1;
1099                         temp_range.start = mend + 1;
1100                         temp_range.end = end;
1101                 } else if (mstart != start)
1102                         mem->ranges[i].end = mstart - 1;
1103                 else
1104                         mem->ranges[i].start = mend + 1;
1105                 break;
1106         }
1107
1108         /* If a split happened, add the split to array */
1109         if (!temp_range.end)
1110                 return 0;
1111
1112         /* Split happened */
1113         if (i == mem->max_nr_ranges - 1)
1114                 return -ENOMEM;
1115
1116         /* Location where new range should go */
1117         j = i + 1;
1118         if (j < mem->nr_ranges) {
1119                 /* Move over all ranges one slot towards the end */
1120                 for (i = mem->nr_ranges - 1; i >= j; i--)
1121                         mem->ranges[i + 1] = mem->ranges[i];
1122         }
1123
1124         mem->ranges[j].start = temp_range.start;
1125         mem->ranges[j].end = temp_range.end;
1126         mem->nr_ranges++;
1127         return 0;
1128 }
1129
1130 int crash_prepare_elf64_headers(struct crash_mem *mem, int kernel_map,
1131                           void **addr, unsigned long *sz)
1132 {
1133         Elf64_Ehdr *ehdr;
1134         Elf64_Phdr *phdr;
1135         unsigned long nr_cpus = num_possible_cpus(), nr_phdr, elf_sz;
1136         unsigned char *buf;
1137         unsigned int cpu, i;
1138         unsigned long long notes_addr;
1139         unsigned long mstart, mend;
1140
1141         /* extra phdr for vmcoreinfo elf note */
1142         nr_phdr = nr_cpus + 1;
1143         nr_phdr += mem->nr_ranges;
1144
1145         /*
1146          * kexec-tools creates an extra PT_LOAD phdr for kernel text mapping
1147          * area (for example, ffffffff80000000 - ffffffffa0000000 on x86_64).
1148          * I think this is required by tools like gdb. So same physical
1149          * memory will be mapped in two elf headers. One will contain kernel
1150          * text virtual addresses and other will have __va(physical) addresses.
1151          */
1152
1153         nr_phdr++;
1154         elf_sz = sizeof(Elf64_Ehdr) + nr_phdr * sizeof(Elf64_Phdr);
1155         elf_sz = ALIGN(elf_sz, ELF_CORE_HEADER_ALIGN);
1156
1157         buf = vzalloc(elf_sz);
1158         if (!buf)
1159                 return -ENOMEM;
1160
1161         ehdr = (Elf64_Ehdr *)buf;
1162         phdr = (Elf64_Phdr *)(ehdr + 1);
1163         memcpy(ehdr->e_ident, ELFMAG, SELFMAG);
1164         ehdr->e_ident[EI_CLASS] = ELFCLASS64;
1165         ehdr->e_ident[EI_DATA] = ELFDATA2LSB;
1166         ehdr->e_ident[EI_VERSION] = EV_CURRENT;
1167         ehdr->e_ident[EI_OSABI] = ELF_OSABI;
1168         memset(ehdr->e_ident + EI_PAD, 0, EI_NIDENT - EI_PAD);
1169         ehdr->e_type = ET_CORE;
1170         ehdr->e_machine = ELF_ARCH;
1171         ehdr->e_version = EV_CURRENT;
1172         ehdr->e_phoff = sizeof(Elf64_Ehdr);
1173         ehdr->e_ehsize = sizeof(Elf64_Ehdr);
1174         ehdr->e_phentsize = sizeof(Elf64_Phdr);
1175
1176         /* Prepare one phdr of type PT_NOTE for each present cpu */
1177         for_each_present_cpu(cpu) {
1178                 phdr->p_type = PT_NOTE;
1179                 notes_addr = per_cpu_ptr_to_phys(per_cpu_ptr(crash_notes, cpu));
1180                 phdr->p_offset = phdr->p_paddr = notes_addr;
1181                 phdr->p_filesz = phdr->p_memsz = sizeof(note_buf_t);
1182                 (ehdr->e_phnum)++;
1183                 phdr++;
1184         }
1185
1186         /* Prepare one PT_NOTE header for vmcoreinfo */
1187         phdr->p_type = PT_NOTE;
1188         phdr->p_offset = phdr->p_paddr = paddr_vmcoreinfo_note();
1189         phdr->p_filesz = phdr->p_memsz = VMCOREINFO_NOTE_SIZE;
1190         (ehdr->e_phnum)++;
1191         phdr++;
1192
1193         /* Prepare PT_LOAD type program header for kernel text region */
1194         if (kernel_map) {
1195                 phdr->p_type = PT_LOAD;
1196                 phdr->p_flags = PF_R|PF_W|PF_X;
1197                 phdr->p_vaddr = (Elf64_Addr)_text;
1198                 phdr->p_filesz = phdr->p_memsz = _end - _text;
1199                 phdr->p_offset = phdr->p_paddr = __pa_symbol(_text);
1200                 ehdr->e_phnum++;
1201                 phdr++;
1202         }
1203
1204         /* Go through all the ranges in mem->ranges[] and prepare phdr */
1205         for (i = 0; i < mem->nr_ranges; i++) {
1206                 mstart = mem->ranges[i].start;
1207                 mend = mem->ranges[i].end;
1208
1209                 phdr->p_type = PT_LOAD;
1210                 phdr->p_flags = PF_R|PF_W|PF_X;
1211                 phdr->p_offset  = mstart;
1212
1213                 phdr->p_paddr = mstart;
1214                 phdr->p_vaddr = (unsigned long long) __va(mstart);
1215                 phdr->p_filesz = phdr->p_memsz = mend - mstart + 1;
1216                 phdr->p_align = 0;
1217                 ehdr->e_phnum++;
1218                 phdr++;
1219                 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",
1220                         phdr, phdr->p_vaddr, phdr->p_paddr, phdr->p_filesz,
1221                         ehdr->e_phnum, phdr->p_offset);
1222         }
1223
1224         *addr = buf;
1225         *sz = elf_sz;
1226         return 0;
1227 }