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 }