kernel/kexec_file.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * kexec: kexec_file_load system call
   4  *
   5  * Copyright (C) 2014 Red Hat Inc.
   6  * Authors:
   7  *      Vivek Goyal <vgoyal@redhat.com>
   8  */
   9
  10 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  11
  12 #include <linux/capability.h>
  13 #include <linux/mm.h>
  14 #include <linux/file.h>
  15 #include <linux/slab.h>
  16 #include <linux/kexec.h>
  17 #include <linux/memblock.h>
  18 #include <linux/mutex.h>
  19 #include <linux/list.h>
  20 #include <linux/fs.h>
  21 #include <linux/ima.h>
  22 #include <crypto/hash.h>
  23 #include <crypto/sha.h>
  24 #include <linux/elf.h>
  25 #include <linux/elfcore.h>
  26 #include <linux/kernel.h>
  27 #include <linux/syscalls.h>
  28 #include <linux/vmalloc.h>
  29 #include "kexec_internal.h"
  30
  31 static int kexec_calculate_store_digests(struct kimage *image);
  32
  33 /*
  34  * Currently this is the only default function that is exported as some
  35  * architectures need it to do additional handlings.
  36  * In the future, other default functions may be exported too if required.
  37  */
  38 int kexec_image_probe_default(struct kimage *image, void *buf,
  39                               unsigned long buf_len)
  40 {
  41         const struct kexec_file_ops * const *fops;
  42         int ret = -ENOEXEC;
  43
  44         for (fops = &kexec_file_loaders[0]; *fops && (*fops)->probe; ++fops) {
  45                 ret = (*fops)->probe(buf, buf_len);
  46                 if (!ret) {
  47                         image->fops = *fops;
  48                         return ret;
  49                 }
  50         }
  51
  52         return ret;
  53 }
  54
  55 /* Architectures can provide this probe function */
  56 int __weak arch_kexec_kernel_image_probe(struct kimage *image, void *buf,
  57                                          unsigned long buf_len)
  58 {
  59         return kexec_image_probe_default(image, buf, buf_len);
  60 }
  61
  62 static void *kexec_image_load_default(struct kimage *image)
  63 {
  64         if (!image->fops || !image->fops->load)
  65                 return ERR_PTR(-ENOEXEC);
  66
  67         return image->fops->load(image, image->kernel_buf,
  68                                  image->kernel_buf_len, image->initrd_buf,
  69                                  image->initrd_buf_len, image->cmdline_buf,
  70                                  image->cmdline_buf_len);
  71 }
  72
  73 void * __weak arch_kexec_kernel_image_load(struct kimage *image)
  74 {
  75         return kexec_image_load_default(image);
  76 }
  77
  78 int kexec_image_post_load_cleanup_default(struct kimage *image)
  79 {
  80         if (!image->fops || !image->fops->cleanup)
  81                 return 0;
  82
  83         return image->fops->cleanup(image->image_loader_data);
  84 }
  85
  86 int __weak arch_kimage_file_post_load_cleanup(struct kimage *image)
  87 {
  88         return kexec_image_post_load_cleanup_default(image);
  89 }
  90
  91 #ifdef CONFIG_KEXEC_SIG
  92 static int kexec_image_verify_sig_default(struct kimage *image, void *buf,
  93                                           unsigned long buf_len)
  94 {
  95         if (!image->fops || !image->fops->verify_sig) {
  96                 pr_debug("kernel loader does not support signature verification.\n");
  97                 return -EKEYREJECTED;
  98         }
  99
 100         return image->fops->verify_sig(buf, buf_len);
 101 }
 102
 103 int __weak arch_kexec_kernel_verify_sig(struct kimage *image, void *buf,
 104                                         unsigned long buf_len)
 105 {
 106         return kexec_image_verify_sig_default(image, buf, buf_len);
 107 }
 108 #endif
 109
 110 /*
 111  * Free up memory used by kernel, initrd, and command line. This is temporary
 112  * memory allocation which is not needed any more after these buffers have
 113  * been loaded into separate segments and have been copied elsewhere.
 114  */
 115 void kimage_file_post_load_cleanup(struct kimage *image)
 116 {
 117         struct purgatory_info *pi = &image->purgatory_info;
 118
 119         vfree(image->kernel_buf);
 120         image->kernel_buf = NULL;
 121
 122         vfree(image->initrd_buf);
 123         image->initrd_buf = NULL;
 124
 125         kfree(image->cmdline_buf);
 126         image->cmdline_buf = NULL;
 127
 128         vfree(pi->purgatory_buf);
 129         pi->purgatory_buf = NULL;
 130
 131         vfree(pi->sechdrs);
 132         pi->sechdrs = NULL;
 133
 134 #ifdef CONFIG_IMA_KEXEC
 135         vfree(image->ima_buffer);
 136         image->ima_buffer = NULL;
 137 #endif /* CONFIG_IMA_KEXEC */
 138
 139         /* See if architecture has anything to cleanup post load */
 140         arch_kimage_file_post_load_cleanup(image);
 141
 142         /*
 143          * Above call should have called into bootloader to free up
 144          * any data stored in kimage->image_loader_data. It should
 145          * be ok now to free it up.
 146          */
 147         kfree(image->image_loader_data);
 148         image->image_loader_data = NULL;
 149 }
 150
 151 #ifdef CONFIG_KEXEC_SIG
 152 static int
 153 kimage_validate_signature(struct kimage *image)
 154 {
 155         const char *reason;
 156         int ret;
 157
 158         ret = arch_kexec_kernel_verify_sig(image, image->kernel_buf,
 159                                            image->kernel_buf_len);
 160         switch (ret) {
 161         case 0:
 162                 break;
 163
 164                 /* Certain verification errors are non-fatal if we're not
 165                  * checking errors, provided we aren't mandating that there
 166                  * must be a valid signature.
 167                  */
 168         case -ENODATA:
 169                 reason = "kexec of unsigned image";
 170                 goto decide;
 171         case -ENOPKG:
 172                 reason = "kexec of image with unsupported crypto";
 173                 goto decide;
 174         case -ENOKEY:
 175                 reason = "kexec of image with unavailable key";
 176         decide:
 177                 if (IS_ENABLED(CONFIG_KEXEC_SIG_FORCE)) {
 178                         pr_notice("%s rejected\n", reason);
 179                         return ret;
 180                 }
 181
 182                 /* If IMA is guaranteed to appraise a signature on the kexec
 183                  * image, permit it even if the kernel is otherwise locked
 184                  * down.
 185                  */
 186                 if (!ima_appraise_signature(READING_KEXEC_IMAGE) &&
 187                     security_locked_down(LOCKDOWN_KEXEC))
 188                         return -EPERM;
 189
 190                 return 0;
 191
 192                 /* All other errors are fatal, including nomem, unparseable
 193                  * signatures and signature check failures - even if signatures
 194                  * aren't required.
 195                  */
 196         default:
 197                 pr_notice("kernel signature verification failed (%d).\n", ret);
 198         }
 199
 200         return ret;
 201 }
 202 #endif
 203
 204 /*
 205  * In file mode list of segments is prepared by kernel. Copy relevant
 206  * data from user space, do error checking, prepare segment list
 207  */
 208 static int
 209 kimage_file_prepare_segments(struct kimage *image, int kernel_fd, int initrd_fd,
 210                              const char __user *cmdline_ptr,
 211                              unsigned long cmdline_len, unsigned flags)
 212 {
 213         int ret;
 214         void *ldata;
 215         loff_t size;
 216
 217         ret = kernel_read_file_from_fd(kernel_fd, &image->kernel_buf,
 218                                        &size, INT_MAX, READING_KEXEC_IMAGE);
 219         if (ret)
 220                 return ret;
 221         image->kernel_buf_len = size;
 222
 223         /* Call arch image probe handlers */
 224         ret = arch_kexec_kernel_image_probe(image, image->kernel_buf,
 225                                             image->kernel_buf_len);
 226         if (ret)
 227                 goto out;
 228
 229 #ifdef CONFIG_KEXEC_SIG
 230         ret = kimage_validate_signature(image);
 231
 232         if (ret)
 233                 goto out;
 234 #endif
 235         /* It is possible that there no initramfs is being loaded */
 236         if (!(flags & KEXEC_FILE_NO_INITRAMFS)) {
 237                 ret = kernel_read_file_from_fd(initrd_fd, &image->initrd_buf,
 238                                                &size, INT_MAX,
 239                                                READING_KEXEC_INITRAMFS);
 240                 if (ret)
 241                         goto out;
 242                 image->initrd_buf_len = size;
 243         }
 244
 245         if (cmdline_len) {
 246                 image->cmdline_buf = memdup_user(cmdline_ptr, cmdline_len);
 247                 if (IS_ERR(image->cmdline_buf)) {
 248                         ret = PTR_ERR(image->cmdline_buf);
 249                         image->cmdline_buf = NULL;
 250                         goto out;
 251                 }
 252
 253                 image->cmdline_buf_len = cmdline_len;
 254
 255                 /* command line should be a string with last byte null */
 256                 if (image->cmdline_buf[cmdline_len - 1] != '\0') {
 257                         ret = -EINVAL;
 258                         goto out;
 259                 }
 260
 261                 ima_kexec_cmdline(image->cmdline_buf,
 262                                   image->cmdline_buf_len - 1);
 263         }
 264
 265         /* IMA needs to pass the measurement list to the next kernel. */
 266         ima_add_kexec_buffer(image);
 267
 268         /* Call arch image load handlers */
 269         ldata = arch_kexec_kernel_image_load(image);
 270
 271         if (IS_ERR(ldata)) {
 272                 ret = PTR_ERR(ldata);
 273                 goto out;
 274         }
 275
 276         image->image_loader_data = ldata;
 277 out:
 278         /* In case of error, free up all allocated memory in this function */
 279         if (ret)
 280                 kimage_file_post_load_cleanup(image);
 281         return ret;
 282 }
 283
 284 static int
 285 kimage_file_alloc_init(struct kimage **rimage, int kernel_fd,
 286                        int initrd_fd, const char __user *cmdline_ptr,
 287                        unsigned long cmdline_len, unsigned long flags)
 288 {
 289         int ret;
 290         struct kimage *image;
 291         bool kexec_on_panic = flags & KEXEC_FILE_ON_CRASH;
 292
 293         image = do_kimage_alloc_init();
 294         if (!image)
 295                 return -ENOMEM;
 296
 297         image->file_mode = 1;
 298
 299         if (kexec_on_panic) {
 300                 /* Enable special crash kernel control page alloc policy. */
 301                 image->control_page = crashk_res.start;
 302                 image->type = KEXEC_TYPE_CRASH;
 303         }
 304
 305         ret = kimage_file_prepare_segments(image, kernel_fd, initrd_fd,
 306                                            cmdline_ptr, cmdline_len, flags);
 307         if (ret)
 308                 goto out_free_image;
 309
 310         ret = sanity_check_segment_list(image);
 311         if (ret)
 312                 goto out_free_post_load_bufs;
 313
 314         ret = -ENOMEM;
 315         image->control_code_page = kimage_alloc_control_pages(image,
 316                                            get_order(KEXEC_CONTROL_PAGE_SIZE));
 317         if (!image->control_code_page) {
 318                 pr_err("Could not allocate control_code_buffer\n");
 319                 goto out_free_post_load_bufs;
 320         }
 321
 322         if (!kexec_on_panic) {
 323                 image->swap_page = kimage_alloc_control_pages(image, 0);
 324                 if (!image->swap_page) {
 325                         pr_err("Could not allocate swap buffer\n");
 326                         goto out_free_control_pages;
 327                 }
 328         }
 329
 330         *rimage = image;
 331         return 0;
 332 out_free_control_pages:
 333         kimage_free_page_list(&image->control_pages);
 334 out_free_post_load_bufs:
 335         kimage_file_post_load_cleanup(image);
 336 out_free_image:
 337         kfree(image);
 338         return ret;
 339 }
 340
 341 SYSCALL_DEFINE5(kexec_file_load, int, kernel_fd, int, initrd_fd,
 342                 unsigned long, cmdline_len, const char __user *, cmdline_ptr,
 343                 unsigned long, flags)
 344 {
 345         int ret = 0, i;
 346         struct kimage **dest_image, *image;
 347
 348         /* We only trust the superuser with rebooting the system. */
 349         if (!capable(CAP_SYS_BOOT) || kexec_load_disabled)
 350                 return -EPERM;
 351
 352         /* Make sure we have a legal set of flags */
 353         if (flags != (flags & KEXEC_FILE_FLAGS))
 354                 return -EINVAL;
 355
 356         image = NULL;
 357
 358         if (!mutex_trylock(&kexec_mutex))
 359                 return -EBUSY;
 360
 361         dest_image = &kexec_image;
 362         if (flags & KEXEC_FILE_ON_CRASH) {
 363                 dest_image = &kexec_crash_image;
 364                 if (kexec_crash_image)
 365                         arch_kexec_unprotect_crashkres();
 366         }
 367
 368         if (flags & KEXEC_FILE_UNLOAD)
 369                 goto exchange;
 370
 371         /*
 372          * In case of crash, new kernel gets loaded in reserved region. It is
 373          * same memory where old crash kernel might be loaded. Free any
 374          * current crash dump kernel before we corrupt it.
 375          */
 376         if (flags & KEXEC_FILE_ON_CRASH)
 377                 kimage_free(xchg(&kexec_crash_image, NULL));
 378
 379         ret = kimage_file_alloc_init(&image, kernel_fd, initrd_fd, cmdline_ptr,
 380                                      cmdline_len, flags);
 381         if (ret)
 382                 goto out;
 383
 384         ret = machine_kexec_prepare(image);
 385         if (ret)
 386                 goto out;
 387
 388         /*
 389          * Some architecture(like S390) may touch the crash memory before
 390          * machine_kexec_prepare(), we must copy vmcoreinfo data after it.
 391          */
 392         ret = kimage_crash_copy_vmcoreinfo(image);
 393         if (ret)
 394                 goto out;
 395
 396         ret = kexec_calculate_store_digests(image);
 397         if (ret)
 398                 goto out;
 399
 400         for (i = 0; i < image->nr_segments; i++) {
 401                 struct kexec_segment *ksegment;
 402
 403                 ksegment = &image->segment[i];
 404                 pr_debug("Loading segment %d: buf=0x%p bufsz=0x%zx mem=0x%lx memsz=0x%zx\n",
 405                          i, ksegment->buf, ksegment->bufsz, ksegment->mem,
 406                          ksegment->memsz);
 407
 408                 ret = kimage_load_segment(image, &image->segment[i]);
 409                 if (ret)
 410                         goto out;
 411         }
 412
 413         kimage_terminate(image);
 414
 415         /*
 416          * Free up any temporary buffers allocated which are not needed
 417          * after image has been loaded
 418          */
 419         kimage_file_post_load_cleanup(image);
 420 exchange:
 421         image = xchg(dest_image, image);
 422 out:
 423         if ((flags & KEXEC_FILE_ON_CRASH) && kexec_crash_image)
 424                 arch_kexec_protect_crashkres();
 425
 426         mutex_unlock(&kexec_mutex);
 427         kimage_free(image);
 428         return ret;
 429 }
 430
 431 static int locate_mem_hole_top_down(unsigned long start, unsigned long end,
 432                                     struct kexec_buf *kbuf)
 433 {
 434         struct kimage *image = kbuf->image;
 435         unsigned long temp_start, temp_end;
 436
 437         temp_end = min(end, kbuf->buf_max);
 438         temp_start = temp_end - kbuf->memsz;
 439
 440         do {
 441                 /* align down start */
 442                 temp_start = temp_start & (~(kbuf->buf_align - 1));
 443
 444                 if (temp_start < start || temp_start < kbuf->buf_min)
 445                         return 0;
 446
 447                 temp_end = temp_start + kbuf->memsz - 1;
 448
 449                 /*
 450                  * Make sure this does not conflict with any of existing
 451                  * segments
 452                  */
 453                 if (kimage_is_destination_range(image, temp_start, temp_end)) {
 454                         temp_start = temp_start - PAGE_SIZE;
 455                         continue;
 456                 }
 457
 458                 /* We found a suitable memory range */
 459                 break;
 460         } while (1);
 461
 462         /* If we are here, we found a suitable memory range */
 463         kbuf->mem = temp_start;
 464
 465         /* Success, stop navigating through remaining System RAM ranges */
 466         return 1;
 467 }
 468
 469 static int locate_mem_hole_bottom_up(unsigned long start, unsigned long end,
 470                                      struct kexec_buf *kbuf)
 471 {
 472         struct kimage *image = kbuf->image;
 473         unsigned long temp_start, temp_end;
 474
 475         temp_start = max(start, kbuf->buf_min);
 476
 477         do {
 478                 temp_start = ALIGN(temp_start, kbuf->buf_align);
 479                 temp_end = temp_start + kbuf->memsz - 1;
 480
 481                 if (temp_end > end || temp_end > kbuf->buf_max)
 482                         return 0;
 483                 /*
 484                  * Make sure this does not conflict with any of existing
 485                  * segments
 486                  */
 487                 if (kimage_is_destination_range(image, temp_start, temp_end)) {
 488                         temp_start = temp_start + PAGE_SIZE;
 489                         continue;
 490                 }
 491
 492                 /* We found a suitable memory range */
 493                 break;
 494         } while (1);
 495
 496         /* If we are here, we found a suitable memory range */
 497         kbuf->mem = temp_start;
 498
 499         /* Success, stop navigating through remaining System RAM ranges */
 500         return 1;
 501 }
 502
 503 static int locate_mem_hole_callback(struct resource *res, void *arg)
 504 {
 505         struct kexec_buf *kbuf = (struct kexec_buf *)arg;
 506         u64 start = res->start, end = res->end;
 507         unsigned long sz = end - start + 1;
 508
 509         /* Returning 0 will take to next memory range */
 510         if (sz < kbuf->memsz)
 511                 return 0;
 512
 513         if (end < kbuf->buf_min || start > kbuf->buf_max)
 514                 return 0;
 515
 516         /*
 517          * Allocate memory top down with-in ram range. Otherwise bottom up
 518          * allocation.
 519          */
 520         if (kbuf->top_down)
 521                 return locate_mem_hole_top_down(start, end, kbuf);
 522         return locate_mem_hole_bottom_up(start, end, kbuf);
 523 }
 524
 525 #ifdef CONFIG_ARCH_KEEP_MEMBLOCK
 526 static int kexec_walk_memblock(struct kexec_buf *kbuf,
 527                                int (*func)(struct resource *, void *))
 528 {
 529         int ret = 0;
 530         u64 i;
 531         phys_addr_t mstart, mend;
 532         struct resource res = { };
 533
 534         if (kbuf->image->type == KEXEC_TYPE_CRASH)
 535                 return func(&crashk_res, kbuf);
 536
 537         if (kbuf->top_down) {
 538                 for_each_free_mem_range_reverse(i, NUMA_NO_NODE, MEMBLOCK_NONE,
 539                                                 &mstart, &mend, NULL) {
 540                         /*
 541                          * In memblock, end points to the first byte after the
 542                          * range while in kexec, end points to the last byte
 543                          * in the range.
 544                          */
 545                         res.start = mstart;
 546                         res.end = mend - 1;
 547                         ret = func(&res, kbuf);
 548                         if (ret)
 549                                 break;
 550                 }
 551         } else {
 552                 for_each_free_mem_range(i, NUMA_NO_NODE, MEMBLOCK_NONE,
 553                                         &mstart, &mend, NULL) {
 554                         /*
 555                          * In memblock, end points to the first byte after the
 556                          * range while in kexec, end points to the last byte
 557                          * in the range.
 558                          */
 559                         res.start = mstart;
 560                         res.end = mend - 1;
 561                         ret = func(&res, kbuf);
 562                         if (ret)
 563                                 break;
 564                 }
 565         }
 566
 567         return ret;
 568 }
 569 #else
 570 static int kexec_walk_memblock(struct kexec_buf *kbuf,
 571                                int (*func)(struct resource *, void *))
 572 {
 573         return 0;
 574 }
 575 #endif
 576
 577 /**
 578  * kexec_walk_resources - call func(data) on free memory regions
 579  * @kbuf:       Context info for the search. Also passed to @func.
 580  * @func:       Function to call for each memory region.
 581  *
 582  * Return: The memory walk will stop when func returns a non-zero value
 583  * and that value will be returned. If all free regions are visited without
 584  * func returning non-zero, then zero will be returned.
 585  */
 586 static int kexec_walk_resources(struct kexec_buf *kbuf,
 587                                 int (*func)(struct resource *, void *))
 588 {
 589         if (kbuf->image->type == KEXEC_TYPE_CRASH)
 590                 return walk_iomem_res_desc(crashk_res.desc,
 591                                            IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY,
 592                                            crashk_res.start, crashk_res.end,
 593                                            kbuf, func);
 594         else
 595                 return walk_system_ram_res(0, ULONG_MAX, kbuf, func);
 596 }
 597
 598 /**
 599  * kexec_locate_mem_hole - find free memory for the purgatory or the next kernel
 600  * @kbuf:       Parameters for the memory search.
 601  *
 602  * On success, kbuf->mem will have the start address of the memory region found.
 603  *
 604  * Return: 0 on success, negative errno on error.
 605  */
 606 int kexec_locate_mem_hole(struct kexec_buf *kbuf)
 607 {
 608         int ret;
 609
 610         /* Arch knows where to place */
 611         if (kbuf->mem != KEXEC_BUF_MEM_UNKNOWN)
 612                 return 0;
 613
 614         if (!IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK))
 615                 ret = kexec_walk_resources(kbuf, locate_mem_hole_callback);
 616         else
 617                 ret = kexec_walk_memblock(kbuf, locate_mem_hole_callback);
 618
 619         return ret == 1 ? 0 : -EADDRNOTAVAIL;
 620 }
 621
 622 /**
 623  * kexec_add_buffer - place a buffer in a kexec segment
 624  * @kbuf:       Buffer contents and memory parameters.
 625  *
 626  * This function assumes that kexec_mutex is held.
 627  * On successful return, @kbuf->mem will have the physical address of
 628  * the buffer in memory.
 629  *
 630  * Return: 0 on success, negative errno on error.
 631  */
 632 int kexec_add_buffer(struct kexec_buf *kbuf)
 633 {
 634
 635         struct kexec_segment *ksegment;
 636         int ret;
 637
 638         /* Currently adding segment this way is allowed only in file mode */
 639         if (!kbuf->image->file_mode)
 640                 return -EINVAL;
 641
 642         if (kbuf->image->nr_segments >= KEXEC_SEGMENT_MAX)
 643                 return -EINVAL;
 644
 645         /*
 646          * Make sure we are not trying to add buffer after allocating
 647          * control pages. All segments need to be placed first before
 648          * any control pages are allocated. As control page allocation
 649          * logic goes through list of segments to make sure there are
 650          * no destination overlaps.
 651          */
 652         if (!list_empty(&kbuf->image->control_pages)) {
 653                 WARN_ON(1);
 654                 return -EINVAL;
 655         }
 656
 657         /* Ensure minimum alignment needed for segments. */
 658         kbuf->memsz = ALIGN(kbuf->memsz, PAGE_SIZE);
 659         kbuf->buf_align = max(kbuf->buf_align, PAGE_SIZE);
 660
 661         /* Walk the RAM ranges and allocate a suitable range for the buffer */
 662         ret = kexec_locate_mem_hole(kbuf);
 663         if (ret)
 664                 return ret;
 665
 666         /* Found a suitable memory range */
 667         ksegment = &kbuf->image->segment[kbuf->image->nr_segments];
 668         ksegment->kbuf = kbuf->buffer;
 669         ksegment->bufsz = kbuf->bufsz;
 670         ksegment->mem = kbuf->mem;
 671         ksegment->memsz = kbuf->memsz;
 672         kbuf->image->nr_segments++;
 673         return 0;
 674 }
 675
 676 /* Calculate and store the digest of segments */
 677 static int kexec_calculate_store_digests(struct kimage *image)
 678 {
 679         struct crypto_shash *tfm;
 680         struct shash_desc *desc;
 681         int ret = 0, i, j, zero_buf_sz, sha_region_sz;
 682         size_t desc_size, nullsz;
 683         char *digest;
 684         void *zero_buf;
 685         struct kexec_sha_region *sha_regions;
 686         struct purgatory_info *pi = &image->purgatory_info;
 687
 688         if (!IS_ENABLED(CONFIG_ARCH_HAS_KEXEC_PURGATORY))
 689                 return 0;
 690
 691         zero_buf = __va(page_to_pfn(ZERO_PAGE(0)) << PAGE_SHIFT);
 692         zero_buf_sz = PAGE_SIZE;
 693
 694         tfm = crypto_alloc_shash("sha256", 0, 0);
 695         if (IS_ERR(tfm)) {
 696                 ret = PTR_ERR(tfm);
 697                 goto out;
 698         }
 699
 700         desc_size = crypto_shash_descsize(tfm) + sizeof(*desc);
 701         desc = kzalloc(desc_size, GFP_KERNEL);
 702         if (!desc) {
 703                 ret = -ENOMEM;
 704                 goto out_free_tfm;
 705         }
 706
 707         sha_region_sz = KEXEC_SEGMENT_MAX * sizeof(struct kexec_sha_region);
 708         sha_regions = vzalloc(sha_region_sz);
 709         if (!sha_regions) {
 710                 ret = -ENOMEM;
 711                 goto out_free_desc;
 712         }
 713
 714         desc->tfm   = tfm;
 715
 716         ret = crypto_shash_init(desc);
 717         if (ret < 0)
 718                 goto out_free_sha_regions;
 719
 720         digest = kzalloc(SHA256_DIGEST_SIZE, GFP_KERNEL);
 721         if (!digest) {
 722                 ret = -ENOMEM;
 723                 goto out_free_sha_regions;
 724         }
 725
 726         for (j = i = 0; i < image->nr_segments; i++) {
 727                 struct kexec_segment *ksegment;
 728
 729                 ksegment = &image->segment[i];
 730                 /*
 731                  * Skip purgatory as it will be modified once we put digest
 732                  * info in purgatory.
 733                  */
 734                 if (ksegment->kbuf == pi->purgatory_buf)
 735                         continue;
 736
 737                 ret = crypto_shash_update(desc, ksegment->kbuf,
 738                                           ksegment->bufsz);
 739                 if (ret)
 740                         break;
 741
 742                 /*
 743                  * Assume rest of the buffer is filled with zero and
 744                  * update digest accordingly.
 745                  */
 746                 nullsz = ksegment->memsz - ksegment->bufsz;
 747                 while (nullsz) {
 748                         unsigned long bytes = nullsz;
 749
 750                         if (bytes > zero_buf_sz)
 751                                 bytes = zero_buf_sz;
 752                         ret = crypto_shash_update(desc, zero_buf, bytes);
 753                         if (ret)
 754                                 break;
 755                         nullsz -= bytes;
 756                 }
 757
 758                 if (ret)
 759                         break;
 760
 761                 sha_regions[j].start = ksegment->mem;
 762                 sha_regions[j].len = ksegment->memsz;
 763                 j++;
 764         }
 765
 766         if (!ret) {
 767                 ret = crypto_shash_final(desc, digest);
 768                 if (ret)
 769                         goto out_free_digest;
 770                 ret = kexec_purgatory_get_set_symbol(image, "purgatory_sha_regions",
 771                                                      sha_regions, sha_region_sz, 0);
 772                 if (ret)
 773                         goto out_free_digest;
 774
 775                 ret = kexec_purgatory_get_set_symbol(image, "purgatory_sha256_digest",
 776                                                      digest, SHA256_DIGEST_SIZE, 0);
 777                 if (ret)
 778                         goto out_free_digest;
 779         }
 780
 781 out_free_digest:
 782         kfree(digest);
 783 out_free_sha_regions:
 784         vfree(sha_regions);
 785 out_free_desc:
 786         kfree(desc);
 787 out_free_tfm:
 788         kfree(tfm);
 789 out:
 790         return ret;
 791 }
 792
 793 #ifdef CONFIG_ARCH_HAS_KEXEC_PURGATORY
 794 /*
 795  * kexec_purgatory_setup_kbuf - prepare buffer to load purgatory.
 796  * @pi:         Purgatory to be loaded.
 797  * @kbuf:       Buffer to setup.
 798  *
 799  * Allocates the memory needed for the buffer. Caller is responsible to free
 800  * the memory after use.
 801  *
 802  * Return: 0 on success, negative errno on error.
 803  */
 804 static int kexec_purgatory_setup_kbuf(struct purgatory_info *pi,
 805                                       struct kexec_buf *kbuf)
 806 {
 807         const Elf_Shdr *sechdrs;
 808         unsigned long bss_align;
 809         unsigned long bss_sz;
 810         unsigned long align;
 811         int i, ret;
 812
 813         sechdrs = (void *)pi->ehdr + pi->ehdr->e_shoff;
 814         kbuf->buf_align = bss_align = 1;
 815         kbuf->bufsz = bss_sz = 0;
 816
 817         for (i = 0; i < pi->ehdr->e_shnum; i++) {
 818                 if (!(sechdrs[i].sh_flags & SHF_ALLOC))
 819                         continue;
 820
 821                 align = sechdrs[i].sh_addralign;
 822                 if (sechdrs[i].sh_type != SHT_NOBITS) {
 823                         if (kbuf->buf_align < align)
 824                                 kbuf->buf_align = align;
 825                         kbuf->bufsz = ALIGN(kbuf->bufsz, align);
 826                         kbuf->bufsz += sechdrs[i].sh_size;
 827                 } else {
 828                         if (bss_align < align)
 829                                 bss_align = align;
 830                         bss_sz = ALIGN(bss_sz, align);
 831                         bss_sz += sechdrs[i].sh_size;
 832                 }
 833         }
 834         kbuf->bufsz = ALIGN(kbuf->bufsz, bss_align);
 835         kbuf->memsz = kbuf->bufsz + bss_sz;
 836         if (kbuf->buf_align < bss_align)
 837                 kbuf->buf_align = bss_align;
 838
 839         kbuf->buffer = vzalloc(kbuf->bufsz);
 840         if (!kbuf->buffer)
 841                 return -ENOMEM;
 842         pi->purgatory_buf = kbuf->buffer;
 843
 844         ret = kexec_add_buffer(kbuf);
 845         if (ret)
 846                 goto out;
 847
 848         return 0;
 849 out:
 850         vfree(pi->purgatory_buf);
 851         pi->purgatory_buf = NULL;
 852         return ret;
 853 }
 854
 855 /*
 856  * kexec_purgatory_setup_sechdrs - prepares the pi->sechdrs buffer.
 857  * @pi:         Purgatory to be loaded.
 858  * @kbuf:       Buffer prepared to store purgatory.
 859  *
 860  * Allocates the memory needed for the buffer. Caller is responsible to free
 861  * the memory after use.
 862  *
 863  * Return: 0 on success, negative errno on error.
 864  */
 865 static int kexec_purgatory_setup_sechdrs(struct purgatory_info *pi,
 866                                          struct kexec_buf *kbuf)
 867 {
 868         unsigned long bss_addr;
 869         unsigned long offset;
 870         Elf_Shdr *sechdrs;
 871         int i;
 872
 873         /*
 874          * The section headers in kexec_purgatory are read-only. In order to
 875          * have them modifiable make a temporary copy.
 876          */
 877         sechdrs = vzalloc(array_size(sizeof(Elf_Shdr), pi->ehdr->e_shnum));
 878         if (!sechdrs)
 879                 return -ENOMEM;
 880         memcpy(sechdrs, (void *)pi->ehdr + pi->ehdr->e_shoff,
 881                pi->ehdr->e_shnum * sizeof(Elf_Shdr));
 882         pi->sechdrs = sechdrs;
 883
 884         offset = 0;
 885         bss_addr = kbuf->mem + kbuf->bufsz;
 886         kbuf->image->start = pi->ehdr->e_entry;
 887
 888         for (i = 0; i < pi->ehdr->e_shnum; i++) {
 889                 unsigned long align;
 890                 void *src, *dst;
 891
 892                 if (!(sechdrs[i].sh_flags & SHF_ALLOC))
 893                         continue;
 894
 895                 align = sechdrs[i].sh_addralign;
 896                 if (sechdrs[i].sh_type == SHT_NOBITS) {
 897                         bss_addr = ALIGN(bss_addr, align);
 898                         sechdrs[i].sh_addr = bss_addr;
 899                         bss_addr += sechdrs[i].sh_size;
 900                         continue;
 901                 }
 902
 903                 offset = ALIGN(offset, align);
 904
 905                 /*
 906                  * Check if the segment contains the entry point, if so,
 907                  * calculate the value of image->start based on it.
 908                  * If the compiler has produced more than one .text section
 909                  * (Eg: .text.hot), they are generally after the main .text
 910                  * section, and they shall not be used to calculate
 911                  * image->start. So do not re-calculate image->start if it
 912                  * is not set to the initial value, and warn the user so they
 913                  * have a chance to fix their purgatory's linker script.
 914                  */
 915                 if (sechdrs[i].sh_flags & SHF_EXECINSTR &&
 916                     pi->ehdr->e_entry >= sechdrs[i].sh_addr &&
 917                     pi->ehdr->e_entry < (sechdrs[i].sh_addr
 918                                          + sechdrs[i].sh_size) &&
 919                     !WARN_ON(kbuf->image->start != pi->ehdr->e_entry)) {
 920                         kbuf->image->start -= sechdrs[i].sh_addr;
 921                         kbuf->image->start += kbuf->mem + offset;
 922                 }
 923
 924                 src = (void *)pi->ehdr + sechdrs[i].sh_offset;
 925                 dst = pi->purgatory_buf + offset;
 926                 memcpy(dst, src, sechdrs[i].sh_size);
 927
 928                 sechdrs[i].sh_addr = kbuf->mem + offset;
 929                 sechdrs[i].sh_offset = offset;
 930                 offset += sechdrs[i].sh_size;
 931         }
 932
 933         return 0;
 934 }
 935
 936 static int kexec_apply_relocations(struct kimage *image)
 937 {
 938         int i, ret;
 939         struct purgatory_info *pi = &image->purgatory_info;
 940         const Elf_Shdr *sechdrs;
 941
 942         sechdrs = (void *)pi->ehdr + pi->ehdr->e_shoff;
 943
 944         for (i = 0; i < pi->ehdr->e_shnum; i++) {
 945                 const Elf_Shdr *relsec;
 946                 const Elf_Shdr *symtab;
 947                 Elf_Shdr *section;
 948
 949                 relsec = sechdrs + i;
 950
 951                 if (relsec->sh_type != SHT_RELA &&
 952                     relsec->sh_type != SHT_REL)
 953                         continue;
 954
 955                 /*
 956                  * For section of type SHT_RELA/SHT_REL,
 957                  * ->sh_link contains section header index of associated
 958                  * symbol table. And ->sh_info contains section header
 959                  * index of section to which relocations apply.
 960                  */
 961                 if (relsec->sh_info >= pi->ehdr->e_shnum ||
 962                     relsec->sh_link >= pi->ehdr->e_shnum)
 963                         return -ENOEXEC;
 964
 965                 section = pi->sechdrs + relsec->sh_info;
 966                 symtab = sechdrs + relsec->sh_link;
 967
 968                 if (!(section->sh_flags & SHF_ALLOC))
 969                         continue;
 970
 971                 /*
 972                  * symtab->sh_link contain section header index of associated
 973                  * string table.
 974                  */
 975                 if (symtab->sh_link >= pi->ehdr->e_shnum)
 976                         /* Invalid section number? */
 977                         continue;
 978
 979                 /*
 980                  * Respective architecture needs to provide support for applying
 981                  * relocations of type SHT_RELA/SHT_REL.
 982                  */
 983                 if (relsec->sh_type == SHT_RELA)
 984                         ret = arch_kexec_apply_relocations_add(pi, section,
 985                                                                relsec, symtab);
 986                 else if (relsec->sh_type == SHT_REL)
 987                         ret = arch_kexec_apply_relocations(pi, section,
 988                                                            relsec, symtab);
 989                 if (ret)
 990                         return ret;
 991         }
 992
 993         return 0;
 994 }
 995
 996 /*
 997  * kexec_load_purgatory - Load and relocate the purgatory object.
 998  * @image:      Image to add the purgatory to.
 999  * @kbuf:       Memory parameters to use.
1000  *
1001  * Allocates the memory needed for image->purgatory_info.sechdrs and
1002  * image->purgatory_info.purgatory_buf/kbuf->buffer. Caller is responsible
1003  * to free the memory after use.
1004  *
1005  * Return: 0 on success, negative errno on error.
1006  */
1007 int kexec_load_purgatory(struct kimage *image, struct kexec_buf *kbuf)
1008 {
1009         struct purgatory_info *pi = &image->purgatory_info;
1010         int ret;
1011
1012         if (kexec_purgatory_size <= 0)
1013                 return -EINVAL;
1014
1015         pi->ehdr = (const Elf_Ehdr *)kexec_purgatory;
1016
1017         ret = kexec_purgatory_setup_kbuf(pi, kbuf);
1018         if (ret)
1019                 return ret;
1020
1021         ret = kexec_purgatory_setup_sechdrs(pi, kbuf);
1022         if (ret)
1023                 goto out_free_kbuf;
1024
1025         ret = kexec_apply_relocations(image);
1026         if (ret)
1027                 goto out;
1028
1029         return 0;
1030 out:
1031         vfree(pi->sechdrs);
1032         pi->sechdrs = NULL;
1033 out_free_kbuf:
1034         vfree(pi->purgatory_buf);
1035         pi->purgatory_buf = NULL;
1036         return ret;
1037 }
1038
1039 /*
1040  * kexec_purgatory_find_symbol - find a symbol in the purgatory
1041  * @pi:         Purgatory to search in.
1042  * @name:       Name of the symbol.
1043  *
1044  * Return: pointer to symbol in read-only symtab on success, NULL on error.
1045  */
1046 static const Elf_Sym *kexec_purgatory_find_symbol(struct purgatory_info *pi,
1047                                                   const char *name)
1048 {
1049         const Elf_Shdr *sechdrs;
1050         const Elf_Ehdr *ehdr;
1051         const Elf_Sym *syms;
1052         const char *strtab;
1053         int i, k;
1054
1055         if (!pi->ehdr)
1056                 return NULL;
1057
1058         ehdr = pi->ehdr;
1059         sechdrs = (void *)ehdr + ehdr->e_shoff;
1060
1061         for (i = 0; i < ehdr->e_shnum; i++) {
1062                 if (sechdrs[i].sh_type != SHT_SYMTAB)
1063                         continue;
1064
1065                 if (sechdrs[i].sh_link >= ehdr->e_shnum)
1066                         /* Invalid strtab section number */
1067                         continue;
1068                 strtab = (void *)ehdr + sechdrs[sechdrs[i].sh_link].sh_offset;
1069                 syms = (void *)ehdr + sechdrs[i].sh_offset;
1070
1071                 /* Go through symbols for a match */
1072                 for (k = 0; k < sechdrs[i].sh_size/sizeof(Elf_Sym); k++) {
1073                         if (ELF_ST_BIND(syms[k].st_info) != STB_GLOBAL)
1074                                 continue;
1075
1076                         if (strcmp(strtab + syms[k].st_name, name) != 0)
1077                                 continue;
1078
1079                         if (syms[k].st_shndx == SHN_UNDEF ||
1080                             syms[k].st_shndx >= ehdr->e_shnum) {
1081                                 pr_debug("Symbol: %s has bad section index %d.\n",
1082                                                 name, syms[k].st_shndx);
1083                                 return NULL;
1084                         }
1085
1086                         /* Found the symbol we are looking for */
1087                         return &syms[k];
1088                 }
1089         }
1090
1091         return NULL;
1092 }
1093
1094 void *kexec_purgatory_get_symbol_addr(struct kimage *image, const char *name)
1095 {
1096         struct purgatory_info *pi = &image->purgatory_info;
1097         const Elf_Sym *sym;
1098         Elf_Shdr *sechdr;
1099
1100         sym = kexec_purgatory_find_symbol(pi, name);
1101         if (!sym)
1102                 return ERR_PTR(-EINVAL);
1103
1104         sechdr = &pi->sechdrs[sym->st_shndx];
1105
1106         /*
1107          * Returns the address where symbol will finally be loaded after
1108          * kexec_load_segment()
1109          */
1110         return (void *)(sechdr->sh_addr + sym->st_value);
1111 }
1112
1113 /*
1114  * Get or set value of a symbol. If "get_value" is true, symbol value is
1115  * returned in buf otherwise symbol value is set based on value in buf.
1116  */
1117 int kexec_purgatory_get_set_symbol(struct kimage *image, const char *name,
1118                                    void *buf, unsigned int size, bool get_value)
1119 {
1120         struct purgatory_info *pi = &image->purgatory_info;
1121         const Elf_Sym *sym;
1122         Elf_Shdr *sec;
1123         char *sym_buf;
1124
1125         sym = kexec_purgatory_find_symbol(pi, name);
1126         if (!sym)
1127                 return -EINVAL;
1128
1129         if (sym->st_size != size) {
1130                 pr_err("symbol %s size mismatch: expected %lu actual %u\n",
1131                        name, (unsigned long)sym->st_size, size);
1132                 return -EINVAL;
1133         }
1134
1135         sec = pi->sechdrs + sym->st_shndx;
1136
1137         if (sec->sh_type == SHT_NOBITS) {
1138                 pr_err("symbol %s is in a bss section. Cannot %s\n", name,
1139                        get_value ? "get" : "set");
1140                 return -EINVAL;
1141         }
1142
1143         sym_buf = (char *)pi->purgatory_buf + sec->sh_offset + sym->st_value;
1144
1145         if (get_value)
1146                 memcpy((void *)buf, sym_buf, size);
1147         else
1148                 memcpy((void *)sym_buf, buf, size);
1149
1150         return 0;
1151 }
1152 #endif /* CONFIG_ARCH_HAS_KEXEC_PURGATORY */
1153
1154 int crash_exclude_mem_range(struct crash_mem *mem,
1155                             unsigned long long mstart, unsigned long long mend)
1156 {
1157         int i, j;
1158         unsigned long long start, end;
1159         struct crash_mem_range temp_range = {0, 0};
1160
1161         for (i = 0; i < mem->nr_ranges; i++) {
1162                 start = mem->ranges[i].start;
1163                 end = mem->ranges[i].end;
1164
1165                 if (mstart > end || mend < start)
1166                         continue;
1167
1168                 /* Truncate any area outside of range */
1169                 if (mstart < start)
1170                         mstart = start;
1171                 if (mend > end)
1172                         mend = end;
1173
1174                 /* Found completely overlapping range */
1175                 if (mstart == start && mend == end) {
1176                         mem->ranges[i].start = 0;
1177                         mem->ranges[i].end = 0;
1178                         if (i < mem->nr_ranges - 1) {
1179                                 /* Shift rest of the ranges to left */
1180                                 for (j = i; j < mem->nr_ranges - 1; j++) {
1181                                         mem->ranges[j].start =
1182                                                 mem->ranges[j+1].start;
1183                                         mem->ranges[j].end =
1184                                                         mem->ranges[j+1].end;
1185                                 }
1186                         }
1187                         mem->nr_ranges--;
1188                         return 0;
1189                 }
1190
1191                 if (mstart > start && mend < end) {
1192                         /* Split original range */
1193                         mem->ranges[i].end = mstart - 1;
1194                         temp_range.start = mend + 1;
1195                         temp_range.end = end;
1196                 } else if (mstart != start)
1197                         mem->ranges[i].end = mstart - 1;
1198                 else
1199                         mem->ranges[i].start = mend + 1;
1200                 break;
1201         }
1202
1203         /* If a split happened, add the split to array */
1204         if (!temp_range.end)
1205                 return 0;
1206
1207         /* Split happened */
1208         if (i == mem->max_nr_ranges - 1)
1209                 return -ENOMEM;
1210
1211         /* Location where new range should go */
1212         j = i + 1;
1213         if (j < mem->nr_ranges) {
1214                 /* Move over all ranges one slot towards the end */
1215                 for (i = mem->nr_ranges - 1; i >= j; i--)
1216                         mem->ranges[i + 1] = mem->ranges[i];
1217         }
1218
1219         mem->ranges[j].start = temp_range.start;
1220         mem->ranges[j].end = temp_range.end;
1221         mem->nr_ranges++;
1222         return 0;
1223 }
1224
1225 int crash_prepare_elf64_headers(struct crash_mem *mem, int kernel_map,
1226                           void **addr, unsigned long *sz)
1227 {
1228         Elf64_Ehdr *ehdr;
1229         Elf64_Phdr *phdr;
1230         unsigned long nr_cpus = num_possible_cpus(), nr_phdr, elf_sz;
1231         unsigned char *buf;
1232         unsigned int cpu, i;
1233         unsigned long long notes_addr;
1234         unsigned long mstart, mend;
1235
1236         /* extra phdr for vmcoreinfo elf note */
1237         nr_phdr = nr_cpus + 1;
1238         nr_phdr += mem->nr_ranges;
1239
1240         /*
1241          * kexec-tools creates an extra PT_LOAD phdr for kernel text mapping
1242          * area (for example, ffffffff80000000 - ffffffffa0000000 on x86_64).
1243          * I think this is required by tools like gdb. So same physical
1244          * memory will be mapped in two elf headers. One will contain kernel
1245          * text virtual addresses and other will have __va(physical) addresses.
1246          */
1247
1248         nr_phdr++;
1249         elf_sz = sizeof(Elf64_Ehdr) + nr_phdr * sizeof(Elf64_Phdr);
1250         elf_sz = ALIGN(elf_sz, ELF_CORE_HEADER_ALIGN);
1251
1252         buf = vzalloc(elf_sz);
1253         if (!buf)
1254                 return -ENOMEM;
1255
1256         ehdr = (Elf64_Ehdr *)buf;
1257         phdr = (Elf64_Phdr *)(ehdr + 1);
1258         memcpy(ehdr->e_ident, ELFMAG, SELFMAG);
1259         ehdr->e_ident[EI_CLASS] = ELFCLASS64;
1260         ehdr->e_ident[EI_DATA] = ELFDATA2LSB;
1261         ehdr->e_ident[EI_VERSION] = EV_CURRENT;
1262         ehdr->e_ident[EI_OSABI] = ELF_OSABI;
1263         memset(ehdr->e_ident + EI_PAD, 0, EI_NIDENT - EI_PAD);
1264         ehdr->e_type = ET_CORE;
1265         ehdr->e_machine = ELF_ARCH;
1266         ehdr->e_version = EV_CURRENT;
1267         ehdr->e_phoff = sizeof(Elf64_Ehdr);
1268         ehdr->e_ehsize = sizeof(Elf64_Ehdr);
1269         ehdr->e_phentsize = sizeof(Elf64_Phdr);
1270
1271         /* Prepare one phdr of type PT_NOTE for each present cpu */
1272         for_each_present_cpu(cpu) {
1273                 phdr->p_type = PT_NOTE;
1274                 notes_addr = per_cpu_ptr_to_phys(per_cpu_ptr(crash_notes, cpu));
1275                 phdr->p_offset = phdr->p_paddr = notes_addr;
1276                 phdr->p_filesz = phdr->p_memsz = sizeof(note_buf_t);
1277                 (ehdr->e_phnum)++;
1278                 phdr++;
1279         }
1280
1281         /* Prepare one PT_NOTE header for vmcoreinfo */
1282         phdr->p_type = PT_NOTE;
1283         phdr->p_offset = phdr->p_paddr = paddr_vmcoreinfo_note();
1284         phdr->p_filesz = phdr->p_memsz = VMCOREINFO_NOTE_SIZE;
1285         (ehdr->e_phnum)++;
1286         phdr++;
1287
1288         /* Prepare PT_LOAD type program header for kernel text region */
1289         if (kernel_map) {
1290                 phdr->p_type = PT_LOAD;
1291                 phdr->p_flags = PF_R|PF_W|PF_X;
1292                 phdr->p_vaddr = (Elf64_Addr)_text;
1293                 phdr->p_filesz = phdr->p_memsz = _end - _text;
1294                 phdr->p_offset = phdr->p_paddr = __pa_symbol(_text);
1295                 ehdr->e_phnum++;
1296                 phdr++;
1297         }
1298
1299         /* Go through all the ranges in mem->ranges[] and prepare phdr */
1300         for (i = 0; i < mem->nr_ranges; i++) {
1301                 mstart = mem->ranges[i].start;
1302                 mend = mem->ranges[i].end;
1303
1304                 phdr->p_type = PT_LOAD;
1305                 phdr->p_flags = PF_R|PF_W|PF_X;
1306                 phdr->p_offset  = mstart;
1307
1308                 phdr->p_paddr = mstart;
1309                 phdr->p_vaddr = (unsigned long long) __va(mstart);
1310                 phdr->p_filesz = phdr->p_memsz = mend - mstart + 1;
1311                 phdr->p_align = 0;
1312                 ehdr->e_phnum++;
1313                 phdr++;
1314                 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",
1315                         phdr, phdr->p_vaddr, phdr->p_paddr, phdr->p_filesz,
1316                         ehdr->e_phnum, phdr->p_offset);
1317         }
1318
1319         *addr = buf;
1320         *sz = elf_sz;
1321         return 0;
1322 }