| 1 | |
| 2 | |
| 3 | * kexec: kexec_file_load system call
|
| 4 | *
|
| 5 | * Copyright (C) 2014 Red Hat Inc.
|
| 6 | * Authors:
|
| 7 | * Vivek Goyal <[email protected]>
|
| 8 |
|
| 9 |
|
| 10 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
|
| 11 |
|
| 12 | #include <linux/capability.h>
|
| 13 | #include <linux/mm.h>
|
| 14 | #include <linux/file.h>
|
| 15 | #include <linux/slab.h>
|
| 16 | #include <linux/kexec.h>
|
| 17 | #include <linux/memblock.h>
|
| 18 | #include <linux/mutex.h>
|
| 19 | #include <linux/list.h>
|
| 20 | #include <linux/fs.h>
|
| 21 | #include <linux/ima.h>
|
| 22 | #include <crypto/hash.h>
|
| 23 | #include <crypto/sha2.h>
|
| 24 | #include <linux/elf.h>
|
| 25 | #include <linux/elfcore.h>
|
| 26 | #include <linux/kernel.h>
|
| 27 | #include <linux/kernel_read_file.h>
|
| 28 | #include <linux/syscalls.h>
|
| 29 | #include <linux/vmalloc.h>
|
| 30 | #include "kexec_internal.h"
|
| 31 |
|
| 32 | #ifdef CONFIG_KEXEC_SIG
|
| 33 | static bool sig_enforce = IS_ENABLED(CONFIG_KEXEC_SIG_FORCE);
|
| 34 |
|
| 35 | void set_kexec_sig_enforced(void)
|
| 36 | {
|
| 37 | sig_enforce = true;
|
| 38 | }
|
| 39 | #endif
|
| 40 |
|
| 41 | static int kexec_calculate_store_digests(struct kimage *image);
|
| 42 |
|
| 43 |
|
| 44 | #define KEXEC_FILE_SIZE_MAX min_t(s64, 4LL << 30, SSIZE_MAX)
|
| 45 |
|
| 46 | |
| 47 | * Currently this is the only default function that is exported as some
|
| 48 | * architectures need it to do additional handlings.
|
| 49 | * In the future, other default functions may be exported too if required.
|
| 50 |
|
| 51 | int kexec_image_probe_default(struct kimage *image, void *buf,
|
| 52 | unsigned long buf_len)
|
| 53 | {
|
| 54 | const struct kexec_file_ops * const *fops;
|
| 55 | int ret = -ENOEXEC;
|
| 56 |
|
| 57 | for (fops = &kexec_file_loaders[0]; *fops && (*fops)->probe; ++fops) {
|
| 58 | ret = (*fops)->probe(buf, buf_len);
|
| 59 | if (!ret) {
|
| 60 | image->fops = *fops;
|
| 61 | return ret;
|
| 62 | }
|
| 63 | }
|
| 64 |
|
| 65 | return ret;
|
| 66 | }
|
| 67 |
|
| 68 | static void *kexec_image_load_default(struct kimage *image)
|
| 69 | {
|
| 70 | if (!image->fops || !image->fops->load)
|
| 71 | return ERR_PTR(-ENOEXEC);
|
| 72 |
|
| 73 | return image->fops->load(image, image->kernel_buf,
|
| 74 | image->kernel_buf_len, image->initrd_buf,
|
| 75 | image->initrd_buf_len, image->cmdline_buf,
|
| 76 | image->cmdline_buf_len);
|
| 77 | }
|
| 78 |
|
| 79 | int kexec_image_post_load_cleanup_default(struct kimage *image)
|
| 80 | {
|
| 81 | if (!image->fops || !image->fops->cleanup)
|
| 82 | return 0;
|
| 83 |
|
| 84 | return image->fops->cleanup(image->image_loader_data);
|
| 85 | }
|
| 86 |
|
| 87 | |
| 88 | * Free up memory used by kernel, initrd, and command line. This is temporary
|
| 89 | * memory allocation which is not needed any more after these buffers have
|
| 90 | * been loaded into separate segments and have been copied elsewhere.
|
| 91 |
|
| 92 | void kimage_file_post_load_cleanup(struct kimage *image)
|
| 93 | {
|
| 94 | struct purgatory_info *pi = &image->purgatory_info;
|
| 95 |
|
| 96 | vfree(image->kernel_buf);
|
| 97 | image->kernel_buf = NULL;
|
| 98 |
|
| 99 | vfree(image->initrd_buf);
|
| 100 | image->initrd_buf = NULL;
|
| 101 |
|
| 102 | kfree(image->cmdline_buf);
|
| 103 | image->cmdline_buf = NULL;
|
| 104 |
|
| 105 | vfree(pi->purgatory_buf);
|
| 106 | pi->purgatory_buf = NULL;
|
| 107 |
|
| 108 | vfree(pi->sechdrs);
|
| 109 | pi->sechdrs = NULL;
|
| 110 |
|
| 111 | #ifdef CONFIG_IMA_KEXEC
|
| 112 | vfree(image->ima_buffer);
|
| 113 | image->ima_buffer = NULL;
|
| 114 | #endif
|
| 115 |
|
| 116 |
|
| 117 | arch_kimage_file_post_load_cleanup(image);
|
| 118 |
|
| 119 | |
| 120 | * Above call should have called into bootloader to free up
|
| 121 | * any data stored in kimage->image_loader_data. It should
|
| 122 | * be ok now to free it up.
|
| 123 |
|
| 124 | kfree(image->image_loader_data);
|
| 125 | image->image_loader_data = NULL;
|
| 126 |
|
| 127 | kexec_file_dbg_print = false;
|
| 128 | }
|
| 129 |
|
| 130 | #ifdef CONFIG_KEXEC_SIG
|
| 131 | #ifdef CONFIG_SIGNED_PE_FILE_VERIFICATION
|
| 132 | int kexec_kernel_verify_pe_sig(const char *kernel, unsigned long kernel_len)
|
| 133 | {
|
| 134 | int ret;
|
| 135 |
|
| 136 | ret = verify_pefile_signature(kernel, kernel_len,
|
| 137 | VERIFY_USE_SECONDARY_KEYRING,
|
| 138 | VERIFYING_KEXEC_PE_SIGNATURE);
|
| 139 | if (ret == -ENOKEY && IS_ENABLED(CONFIG_INTEGRITY_PLATFORM_KEYRING)) {
|
| 140 | ret = verify_pefile_signature(kernel, kernel_len,
|
| 141 | VERIFY_USE_PLATFORM_KEYRING,
|
| 142 | VERIFYING_KEXEC_PE_SIGNATURE);
|
| 143 | }
|
| 144 | return ret;
|
| 145 | }
|
| 146 | #endif
|
| 147 |
|
| 148 | static int kexec_image_verify_sig(struct kimage *image, void *buf,
|
| 149 | unsigned long buf_len)
|
| 150 | {
|
| 151 | if (!image->fops || !image->fops->verify_sig) {
|
| 152 | pr_debug("kernel loader does not support signature verification.\n");
|
| 153 | return -EKEYREJECTED;
|
| 154 | }
|
| 155 |
|
| 156 | return image->fops->verify_sig(buf, buf_len);
|
| 157 | }
|
| 158 |
|
| 159 | static int
|
| 160 | kimage_validate_signature(struct kimage *image)
|
| 161 | {
|
| 162 | int ret;
|
| 163 |
|
| 164 | ret = kexec_image_verify_sig(image, image->kernel_buf,
|
| 165 | image->kernel_buf_len);
|
| 166 | if (ret) {
|
| 167 |
|
| 168 | if (sig_enforce) {
|
| 169 | pr_notice("Enforced kernel signature verification failed (%d).\n", ret);
|
| 170 | return ret;
|
| 171 | }
|
| 172 |
|
| 173 | |
| 174 | * If IMA is guaranteed to appraise a signature on the kexec
|
| 175 | * image, permit it even if the kernel is otherwise locked
|
| 176 | * down.
|
| 177 |
|
| 178 | if (!ima_appraise_signature(READING_KEXEC_IMAGE) &&
|
| 179 | security_locked_down(LOCKDOWN_KEXEC))
|
| 180 | return -EPERM;
|
| 181 |
|
| 182 | pr_debug("kernel signature verification failed (%d).\n", ret);
|
| 183 | }
|
| 184 |
|
| 185 | return 0;
|
| 186 | }
|
| 187 | #endif
|
| 188 |
|
| 189 | |
| 190 | * In file mode list of segments is prepared by kernel. Copy relevant
|
| 191 | * data from user space, do error checking, prepare segment list
|
| 192 |
|
| 193 | static int
|
| 194 | kimage_file_prepare_segments(struct kimage *image, int kernel_fd, int initrd_fd,
|
| 195 | const char __user *cmdline_ptr,
|
| 196 | unsigned long cmdline_len, unsigned flags)
|
| 197 | {
|
| 198 | ssize_t ret;
|
| 199 | void *ldata;
|
| 200 |
|
| 201 | ret = kernel_read_file_from_fd(kernel_fd, 0, &image->kernel_buf,
|
| 202 | KEXEC_FILE_SIZE_MAX, NULL,
|
| 203 | READING_KEXEC_IMAGE);
|
| 204 | if (ret < 0)
|
| 205 | return ret;
|
| 206 | image->kernel_buf_len = ret;
|
| 207 | kexec_dprintk("kernel: %p kernel_size: %#lx\n",
|
| 208 | image->kernel_buf, image->kernel_buf_len);
|
| 209 |
|
| 210 |
|
| 211 | ret = arch_kexec_kernel_image_probe(image, image->kernel_buf,
|
| 212 | image->kernel_buf_len);
|
| 213 | if (ret)
|
| 214 | goto out;
|
| 215 |
|
| 216 | #ifdef CONFIG_KEXEC_SIG
|
| 217 | ret = kimage_validate_signature(image);
|
| 218 |
|
| 219 | if (ret)
|
| 220 | goto out;
|
| 221 | #endif
|
| 222 |
|
| 223 | if (!(flags & KEXEC_FILE_NO_INITRAMFS)) {
|
| 224 | ret = kernel_read_file_from_fd(initrd_fd, 0, &image->initrd_buf,
|
| 225 | KEXEC_FILE_SIZE_MAX, NULL,
|
| 226 | READING_KEXEC_INITRAMFS);
|
| 227 | if (ret < 0)
|
| 228 | goto out;
|
| 229 | image->initrd_buf_len = ret;
|
| 230 | ret = 0;
|
| 231 | }
|
| 232 |
|
| 233 | if (cmdline_len) {
|
| 234 | image->cmdline_buf = memdup_user(cmdline_ptr, cmdline_len);
|
| 235 | if (IS_ERR(image->cmdline_buf)) {
|
| 236 | ret = PTR_ERR(image->cmdline_buf);
|
| 237 | image->cmdline_buf = NULL;
|
| 238 | goto out;
|
| 239 | }
|
| 240 |
|
| 241 | image->cmdline_buf_len = cmdline_len;
|
| 242 |
|
| 243 |
|
| 244 | if (image->cmdline_buf[cmdline_len - 1] != '\0') {
|
| 245 | ret = -EINVAL;
|
| 246 | goto out;
|
| 247 | }
|
| 248 |
|
| 249 | ima_kexec_cmdline(kernel_fd, image->cmdline_buf,
|
| 250 | image->cmdline_buf_len - 1);
|
| 251 | }
|
| 252 |
|
| 253 |
|
| 254 | ima_add_kexec_buffer(image);
|
| 255 |
|
| 256 |
|
| 257 | ldata = kexec_image_load_default(image);
|
| 258 |
|
| 259 | if (IS_ERR(ldata)) {
|
| 260 | ret = PTR_ERR(ldata);
|
| 261 | goto out;
|
| 262 | }
|
| 263 |
|
| 264 | image->image_loader_data = ldata;
|
| 265 | out:
|
| 266 |
|
| 267 | if (ret)
|
| 268 | kimage_file_post_load_cleanup(image);
|
| 269 | return ret;
|
| 270 | }
|
| 271 |
|
| 272 | static int
|
| 273 | kimage_file_alloc_init(struct kimage **rimage, int kernel_fd,
|
| 274 | int initrd_fd, const char __user *cmdline_ptr,
|
| 275 | unsigned long cmdline_len, unsigned long flags)
|
| 276 | {
|
| 277 | int ret;
|
| 278 | struct kimage *image;
|
| 279 | bool kexec_on_panic = flags & KEXEC_FILE_ON_CRASH;
|
| 280 |
|
| 281 | image = do_kimage_alloc_init();
|
| 282 | if (!image)
|
| 283 | return -ENOMEM;
|
| 284 |
|
| 285 | kexec_file_dbg_print = !!(flags & KEXEC_FILE_DEBUG);
|
| 286 | image->file_mode = 1;
|
| 287 |
|
| 288 | #ifdef CONFIG_CRASH_DUMP
|
| 289 | if (kexec_on_panic) {
|
| 290 |
|
| 291 | image->control_page = crashk_res.start;
|
| 292 | image->type = KEXEC_TYPE_CRASH;
|
| 293 | }
|
| 294 | #endif
|
| 295 |
|
| 296 | ret = kimage_file_prepare_segments(image, kernel_fd, initrd_fd,
|
| 297 | cmdline_ptr, cmdline_len, flags);
|
| 298 | if (ret)
|
| 299 | goto out_free_image;
|
| 300 |
|
| 301 | ret = sanity_check_segment_list(image);
|
| 302 | if (ret)
|
| 303 | goto out_free_post_load_bufs;
|
| 304 |
|
| 305 | ret = -ENOMEM;
|
| 306 | image->control_code_page = kimage_alloc_control_pages(image,
|
| 307 | get_order(KEXEC_CONTROL_PAGE_SIZE));
|
| 308 | if (!image->control_code_page) {
|
| 309 | pr_err("Could not allocate control_code_buffer\n");
|
| 310 | goto out_free_post_load_bufs;
|
| 311 | }
|
| 312 |
|
| 313 | if (!kexec_on_panic) {
|
| 314 | image->swap_page = kimage_alloc_control_pages(image, 0);
|
| 315 | if (!image->swap_page) {
|
| 316 | pr_err("Could not allocate swap buffer\n");
|
| 317 | goto out_free_control_pages;
|
| 318 | }
|
| 319 | }
|
| 320 |
|
| 321 | *rimage = image;
|
| 322 | return 0;
|
| 323 | out_free_control_pages:
|
| 324 | kimage_free_page_list(&image->control_pages);
|
| 325 | out_free_post_load_bufs:
|
| 326 | kimage_file_post_load_cleanup(image);
|
| 327 | out_free_image:
|
| 328 | kfree(image);
|
| 329 | return ret;
|
| 330 | }
|
| 331 |
|
| 332 | SYSCALL_DEFINE5(kexec_file_load, int, kernel_fd, int, initrd_fd,
|
| 333 | unsigned long, cmdline_len, const char __user *, cmdline_ptr,
|
| 334 | unsigned long, flags)
|
| 335 | {
|
| 336 | int image_type = (flags & KEXEC_FILE_ON_CRASH) ?
|
| 337 | KEXEC_TYPE_CRASH : KEXEC_TYPE_DEFAULT;
|
| 338 | struct kimage **dest_image, *image;
|
| 339 | int ret = 0, i;
|
| 340 |
|
| 341 |
|
| 342 | if (!kexec_load_permitted(image_type))
|
| 343 | return -EPERM;
|
| 344 |
|
| 345 |
|
| 346 | if (flags != (flags & KEXEC_FILE_FLAGS))
|
| 347 | return -EINVAL;
|
| 348 |
|
| 349 | image = NULL;
|
| 350 |
|
| 351 | if (!kexec_trylock())
|
| 352 | return -EBUSY;
|
| 353 |
|
| 354 | #ifdef CONFIG_CRASH_DUMP
|
| 355 | if (image_type == KEXEC_TYPE_CRASH) {
|
| 356 | dest_image = &kexec_crash_image;
|
| 357 | if (kexec_crash_image)
|
| 358 | arch_kexec_unprotect_crashkres();
|
| 359 | } else
|
| 360 | #endif
|
| 361 | dest_image = &kexec_image;
|
| 362 |
|
| 363 | if (flags & KEXEC_FILE_UNLOAD)
|
| 364 | goto exchange;
|
| 365 |
|
| 366 | |
| 367 | * In case of crash, new kernel gets loaded in reserved region. It is
|
| 368 | * same memory where old crash kernel might be loaded. Free any
|
| 369 | * current crash dump kernel before we corrupt it.
|
| 370 |
|
| 371 | if (flags & KEXEC_FILE_ON_CRASH)
|
| 372 | kimage_free(xchg(&kexec_crash_image, NULL));
|
| 373 |
|
| 374 | ret = kimage_file_alloc_init(&image, kernel_fd, initrd_fd, cmdline_ptr,
|
| 375 | cmdline_len, flags);
|
| 376 | if (ret)
|
| 377 | goto out;
|
| 378 |
|
| 379 | #ifdef CONFIG_CRASH_HOTPLUG
|
| 380 | if ((flags & KEXEC_FILE_ON_CRASH) && arch_crash_hotplug_support(image, flags))
|
| 381 | image->hotplug_support = 1;
|
| 382 | #endif
|
| 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 | kexec_dprintk("nr_segments = %lu\n", image->nr_segments);
|
| 401 | for (i = 0; i < image->nr_segments; i++) {
|
| 402 | struct kexec_segment *ksegment;
|
| 403 |
|
| 404 | ksegment = &image->segment[i];
|
| 405 | kexec_dprintk("segment[%d]: buf=0x%p bufsz=0x%zx mem=0x%lx memsz=0x%zx\n",
|
| 406 | i, ksegment->buf, ksegment->bufsz, ksegment->mem,
|
| 407 | ksegment->memsz);
|
| 408 |
|
| 409 | ret = kimage_load_segment(image, &image->segment[i]);
|
| 410 | if (ret)
|
| 411 | goto out;
|
| 412 | }
|
| 413 |
|
| 414 | kimage_terminate(image);
|
| 415 |
|
| 416 | ret = machine_kexec_post_load(image);
|
| 417 | if (ret)
|
| 418 | goto out;
|
| 419 |
|
| 420 | kexec_dprintk("kexec_file_load: type:%u, start:0x%lx head:0x%lx flags:0x%lx\n",
|
| 421 | image->type, image->start, image->head, flags);
|
| 422 | |
| 423 | * Free up any temporary buffers allocated which are not needed
|
| 424 | * after image has been loaded
|
| 425 |
|
| 426 | kimage_file_post_load_cleanup(image);
|
| 427 | exchange:
|
| 428 | image = xchg(dest_image, image);
|
| 429 | out:
|
| 430 | #ifdef CONFIG_CRASH_DUMP
|
| 431 | if ((flags & KEXEC_FILE_ON_CRASH) && kexec_crash_image)
|
| 432 | arch_kexec_protect_crashkres();
|
| 433 | #endif
|
| 434 |
|
| 435 | kexec_unlock();
|
| 436 | kimage_free(image);
|
| 437 | return ret;
|
| 438 | }
|
| 439 |
|
| 440 | static int locate_mem_hole_top_down(unsigned long start, unsigned long end,
|
| 441 | struct kexec_buf *kbuf)
|
| 442 | {
|
| 443 | struct kimage *image = kbuf->image;
|
| 444 | unsigned long temp_start, temp_end;
|
| 445 |
|
| 446 | temp_end = min(end, kbuf->buf_max);
|
| 447 | temp_start = temp_end - kbuf->memsz + 1;
|
| 448 |
|
| 449 | do {
|
| 450 |
|
| 451 | temp_start = ALIGN_DOWN(temp_start, kbuf->buf_align);
|
| 452 |
|
| 453 | if (temp_start < start || temp_start < kbuf->buf_min)
|
| 454 | return 0;
|
| 455 |
|
| 456 | temp_end = temp_start + kbuf->memsz - 1;
|
| 457 |
|
| 458 | |
| 459 | * Make sure this does not conflict with any of existing
|
| 460 | * segments
|
| 461 |
|
| 462 | if (kimage_is_destination_range(image, temp_start, temp_end)) {
|
| 463 | temp_start = temp_start - PAGE_SIZE;
|
| 464 | continue;
|
| 465 | }
|
| 466 |
|
| 467 |
|
| 468 | break;
|
| 469 | } while (1);
|
| 470 |
|
| 471 |
|
| 472 | kbuf->mem = temp_start;
|
| 473 |
|
| 474 |
|
| 475 | return 1;
|
| 476 | }
|
| 477 |
|
| 478 | static int locate_mem_hole_bottom_up(unsigned long start, unsigned long end,
|
| 479 | struct kexec_buf *kbuf)
|
| 480 | {
|
| 481 | struct kimage *image = kbuf->image;
|
| 482 | unsigned long temp_start, temp_end;
|
| 483 |
|
| 484 | temp_start = max(start, kbuf->buf_min);
|
| 485 |
|
| 486 | do {
|
| 487 | temp_start = ALIGN(temp_start, kbuf->buf_align);
|
| 488 | temp_end = temp_start + kbuf->memsz - 1;
|
| 489 |
|
| 490 | if (temp_end > end || temp_end > kbuf->buf_max)
|
| 491 | return 0;
|
| 492 | |
| 493 | * Make sure this does not conflict with any of existing
|
| 494 | * segments
|
| 495 |
|
| 496 | if (kimage_is_destination_range(image, temp_start, temp_end)) {
|
| 497 | temp_start = temp_start + PAGE_SIZE;
|
| 498 | continue;
|
| 499 | }
|
| 500 |
|
| 501 |
|
| 502 | break;
|
| 503 | } while (1);
|
| 504 |
|
| 505 |
|
| 506 | kbuf->mem = temp_start;
|
| 507 |
|
| 508 |
|
| 509 | return 1;
|
| 510 | }
|
| 511 |
|
| 512 | static int locate_mem_hole_callback(struct resource *res, void *arg)
|
| 513 | {
|
| 514 | struct kexec_buf *kbuf = (struct kexec_buf *)arg;
|
| 515 | u64 start = res->start, end = res->end;
|
| 516 | unsigned long sz = end - start + 1;
|
| 517 |
|
| 518 |
|
| 519 |
|
| 520 |
|
| 521 | if (res->flags & IORESOURCE_SYSRAM_DRIVER_MANAGED)
|
| 522 | return 0;
|
| 523 |
|
| 524 | if (sz < kbuf->memsz)
|
| 525 | return 0;
|
| 526 |
|
| 527 | if (end < kbuf->buf_min || start > kbuf->buf_max)
|
| 528 | return 0;
|
| 529 |
|
| 530 | |
| 531 | * Allocate memory top down with-in ram range. Otherwise bottom up
|
| 532 | * allocation.
|
| 533 |
|
| 534 | if (kbuf->top_down)
|
| 535 | return locate_mem_hole_top_down(start, end, kbuf);
|
| 536 | return locate_mem_hole_bottom_up(start, end, kbuf);
|
| 537 | }
|
| 538 |
|
| 539 | #ifdef CONFIG_ARCH_KEEP_MEMBLOCK
|
| 540 | static int kexec_walk_memblock(struct kexec_buf *kbuf,
|
| 541 | int (*func)(struct resource *, void *))
|
| 542 | {
|
| 543 | int ret = 0;
|
| 544 | u64 i;
|
| 545 | phys_addr_t mstart, mend;
|
| 546 | struct resource res = { };
|
| 547 |
|
| 548 | #ifdef CONFIG_CRASH_DUMP
|
| 549 | if (kbuf->image->type == KEXEC_TYPE_CRASH)
|
| 550 | return func(&crashk_res, kbuf);
|
| 551 | #endif
|
| 552 |
|
| 553 | |
| 554 | * Using MEMBLOCK_NONE will properly skip MEMBLOCK_DRIVER_MANAGED. See
|
| 555 | * IORESOURCE_SYSRAM_DRIVER_MANAGED handling in
|
| 556 | * locate_mem_hole_callback().
|
| 557 |
|
| 558 | if (kbuf->top_down) {
|
| 559 | for_each_free_mem_range_reverse(i, NUMA_NO_NODE, MEMBLOCK_NONE,
|
| 560 | &mstart, &mend, NULL) {
|
| 561 | |
| 562 | * In memblock, end points to the first byte after the
|
| 563 | * range while in kexec, end points to the last byte
|
| 564 | * in the range.
|
| 565 |
|
| 566 | res.start = mstart;
|
| 567 | res.end = mend - 1;
|
| 568 | ret = func(&res, kbuf);
|
| 569 | if (ret)
|
| 570 | break;
|
| 571 | }
|
| 572 | } else {
|
| 573 | for_each_free_mem_range(i, NUMA_NO_NODE, MEMBLOCK_NONE,
|
| 574 | &mstart, &mend, NULL) {
|
| 575 | |
| 576 | * In memblock, end points to the first byte after the
|
| 577 | * range while in kexec, end points to the last byte
|
| 578 | * in the range.
|
| 579 |
|
| 580 | res.start = mstart;
|
| 581 | res.end = mend - 1;
|
| 582 | ret = func(&res, kbuf);
|
| 583 | if (ret)
|
| 584 | break;
|
| 585 | }
|
| 586 | }
|
| 587 |
|
| 588 | return ret;
|
| 589 | }
|
| 590 | #else
|
| 591 | static int kexec_walk_memblock(struct kexec_buf *kbuf,
|
| 592 | int (*func)(struct resource *, void *))
|
| 593 | {
|
| 594 | return 0;
|
| 595 | }
|
| 596 | #endif
|
| 597 |
|
| 598 | |
| 599 | * kexec_walk_resources - call func(data) on free memory regions
|
| 600 | * @kbuf: Context info for the search. Also passed to @func.
|
| 601 | * @func: Function to call for each memory region.
|
| 602 | *
|
| 603 | * Return: The memory walk will stop when func returns a non-zero value
|
| 604 | * and that value will be returned. If all free regions are visited without
|
| 605 | * func returning non-zero, then zero will be returned.
|
| 606 |
|
| 607 | static int kexec_walk_resources(struct kexec_buf *kbuf,
|
| 608 | int (*func)(struct resource *, void *))
|
| 609 | {
|
| 610 | #ifdef CONFIG_CRASH_DUMP
|
| 611 | if (kbuf->image->type == KEXEC_TYPE_CRASH)
|
| 612 | return walk_iomem_res_desc(crashk_res.desc,
|
| 613 | IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY,
|
| 614 | crashk_res.start, crashk_res.end,
|
| 615 | kbuf, func);
|
| 616 | #endif
|
| 617 | if (kbuf->top_down)
|
| 618 | return walk_system_ram_res_rev(0, ULONG_MAX, kbuf, func);
|
| 619 | else
|
| 620 | return walk_system_ram_res(0, ULONG_MAX, kbuf, func);
|
| 621 | }
|
| 622 |
|
| 623 | |
| 624 | * kexec_locate_mem_hole - find free memory for the purgatory or the next kernel
|
| 625 | * @kbuf: Parameters for the memory search.
|
| 626 | *
|
| 627 | * On success, kbuf->mem will have the start address of the memory region found.
|
| 628 | *
|
| 629 | * Return: 0 on success, negative errno on error.
|
| 630 |
|
| 631 | int kexec_locate_mem_hole(struct kexec_buf *kbuf)
|
| 632 | {
|
| 633 | int ret;
|
| 634 |
|
| 635 |
|
| 636 | if (kbuf->mem != KEXEC_BUF_MEM_UNKNOWN)
|
| 637 | return 0;
|
| 638 |
|
| 639 | if (!IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK))
|
| 640 | ret = kexec_walk_resources(kbuf, locate_mem_hole_callback);
|
| 641 | else
|
| 642 | ret = kexec_walk_memblock(kbuf, locate_mem_hole_callback);
|
| 643 |
|
| 644 | return ret == 1 ? 0 : -EADDRNOTAVAIL;
|
| 645 | }
|
| 646 |
|
| 647 | |
| 648 | * kexec_add_buffer - place a buffer in a kexec segment
|
| 649 | * @kbuf: Buffer contents and memory parameters.
|
| 650 | *
|
| 651 | * This function assumes that kexec_lock is held.
|
| 652 | * On successful return, @kbuf->mem will have the physical address of
|
| 653 | * the buffer in memory.
|
| 654 | *
|
| 655 | * Return: 0 on success, negative errno on error.
|
| 656 |
|
| 657 | int kexec_add_buffer(struct kexec_buf *kbuf)
|
| 658 | {
|
| 659 | struct kexec_segment *ksegment;
|
| 660 | int ret;
|
| 661 |
|
| 662 |
|
| 663 | if (!kbuf->image->file_mode)
|
| 664 | return -EINVAL;
|
| 665 |
|
| 666 | if (kbuf->image->nr_segments >= KEXEC_SEGMENT_MAX)
|
| 667 | return -EINVAL;
|
| 668 |
|
| 669 | |
| 670 | * Make sure we are not trying to add buffer after allocating
|
| 671 | * control pages. All segments need to be placed first before
|
| 672 | * any control pages are allocated. As control page allocation
|
| 673 | * logic goes through list of segments to make sure there are
|
| 674 | * no destination overlaps.
|
| 675 |
|
| 676 | if (!list_empty(&kbuf->image->control_pages)) {
|
| 677 | WARN_ON(1);
|
| 678 | return -EINVAL;
|
| 679 | }
|
| 680 |
|
| 681 |
|
| 682 | kbuf->memsz = ALIGN(kbuf->memsz, PAGE_SIZE);
|
| 683 | kbuf->buf_align = max(kbuf->buf_align, PAGE_SIZE);
|
| 684 |
|
| 685 |
|
| 686 | ret = arch_kexec_locate_mem_hole(kbuf);
|
| 687 | if (ret)
|
| 688 | return ret;
|
| 689 |
|
| 690 |
|
| 691 | ksegment = &kbuf->image->segment[kbuf->image->nr_segments];
|
| 692 | ksegment->kbuf = kbuf->buffer;
|
| 693 | ksegment->bufsz = kbuf->bufsz;
|
| 694 | ksegment->mem = kbuf->mem;
|
| 695 | ksegment->memsz = kbuf->memsz;
|
| 696 | kbuf->image->nr_segments++;
|
| 697 | return 0;
|
| 698 | }
|
| 699 |
|
| 700 |
|
| 701 | static int kexec_calculate_store_digests(struct kimage *image)
|
| 702 | {
|
| 703 | struct crypto_shash *tfm;
|
| 704 | struct shash_desc *desc;
|
| 705 | int ret = 0, i, j, zero_buf_sz, sha_region_sz;
|
| 706 | size_t desc_size, nullsz;
|
| 707 | char *digest;
|
| 708 | void *zero_buf;
|
| 709 | struct kexec_sha_region *sha_regions;
|
| 710 | struct purgatory_info *pi = &image->purgatory_info;
|
| 711 |
|
| 712 | if (!IS_ENABLED(CONFIG_ARCH_SUPPORTS_KEXEC_PURGATORY))
|
| 713 | return 0;
|
| 714 |
|
| 715 | zero_buf = __va(page_to_pfn(ZERO_PAGE(0)) << PAGE_SHIFT);
|
| 716 | zero_buf_sz = PAGE_SIZE;
|
| 717 |
|
| 718 | tfm = crypto_alloc_shash("sha256", 0, 0);
|
| 719 | if (IS_ERR(tfm)) {
|
| 720 | ret = PTR_ERR(tfm);
|
| 721 | goto out;
|
| 722 | }
|
| 723 |
|
| 724 | desc_size = crypto_shash_descsize(tfm) + sizeof(*desc);
|
| 725 | desc = kzalloc(desc_size, GFP_KERNEL);
|
| 726 | if (!desc) {
|
| 727 | ret = -ENOMEM;
|
| 728 | goto out_free_tfm;
|
| 729 | }
|
| 730 |
|
| 731 | sha_region_sz = KEXEC_SEGMENT_MAX * sizeof(struct kexec_sha_region);
|
| 732 | sha_regions = vzalloc(sha_region_sz);
|
| 733 | if (!sha_regions) {
|
| 734 | ret = -ENOMEM;
|
| 735 | goto out_free_desc;
|
| 736 | }
|
| 737 |
|
| 738 | desc->tfm = tfm;
|
| 739 |
|
| 740 | ret = crypto_shash_init(desc);
|
| 741 | if (ret < 0)
|
| 742 | goto out_free_sha_regions;
|
| 743 |
|
| 744 | digest = kzalloc(SHA256_DIGEST_SIZE, GFP_KERNEL);
|
| 745 | if (!digest) {
|
| 746 | ret = -ENOMEM;
|
| 747 | goto out_free_sha_regions;
|
| 748 | }
|
| 749 |
|
| 750 | for (j = i = 0; i < image->nr_segments; i++) {
|
| 751 | struct kexec_segment *ksegment;
|
| 752 |
|
| 753 | #ifdef CONFIG_CRASH_HOTPLUG
|
| 754 |
|
| 755 | if (i == image->elfcorehdr_index)
|
| 756 | continue;
|
| 757 | #endif
|
| 758 |
|
| 759 | ksegment = &image->segment[i];
|
| 760 | |
| 761 | * Skip purgatory as it will be modified once we put digest
|
| 762 | * info in purgatory.
|
| 763 |
|
| 764 | if (ksegment->kbuf == pi->purgatory_buf)
|
| 765 | continue;
|
| 766 |
|
| 767 | ret = crypto_shash_update(desc, ksegment->kbuf,
|
| 768 | ksegment->bufsz);
|
| 769 | if (ret)
|
| 770 | break;
|
| 771 |
|
| 772 | |
| 773 | * Assume rest of the buffer is filled with zero and
|
| 774 | * update digest accordingly.
|
| 775 |
|
| 776 | nullsz = ksegment->memsz - ksegment->bufsz;
|
| 777 | while (nullsz) {
|
| 778 | unsigned long bytes = nullsz;
|
| 779 |
|
| 780 | if (bytes > zero_buf_sz)
|
| 781 | bytes = zero_buf_sz;
|
| 782 | ret = crypto_shash_update(desc, zero_buf, bytes);
|
| 783 | if (ret)
|
| 784 | break;
|
| 785 | nullsz -= bytes;
|
| 786 | }
|
| 787 |
|
| 788 | if (ret)
|
| 789 | break;
|
| 790 |
|
| 791 | sha_regions[j].start = ksegment->mem;
|
| 792 | sha_regions[j].len = ksegment->memsz;
|
| 793 | j++;
|
| 794 | }
|
| 795 |
|
| 796 | if (!ret) {
|
| 797 | ret = crypto_shash_final(desc, digest);
|
| 798 | if (ret)
|
| 799 | goto out_free_digest;
|
| 800 | ret = kexec_purgatory_get_set_symbol(image, "purgatory_sha_regions",
|
| 801 | sha_regions, sha_region_sz, 0);
|
| 802 | if (ret)
|
| 803 | goto out_free_digest;
|
| 804 |
|
| 805 | ret = kexec_purgatory_get_set_symbol(image, "purgatory_sha256_digest",
|
| 806 | digest, SHA256_DIGEST_SIZE, 0);
|
| 807 | if (ret)
|
| 808 | goto out_free_digest;
|
| 809 | }
|
| 810 |
|
| 811 | out_free_digest:
|
| 812 | kfree(digest);
|
| 813 | out_free_sha_regions:
|
| 814 | vfree(sha_regions);
|
| 815 | out_free_desc:
|
| 816 | kfree(desc);
|
| 817 | out_free_tfm:
|
| 818 | kfree(tfm);
|
| 819 | out:
|
| 820 | return ret;
|
| 821 | }
|
| 822 |
|
| 823 | #ifdef CONFIG_ARCH_SUPPORTS_KEXEC_PURGATORY
|
| 824 | |
| 825 | * kexec_purgatory_setup_kbuf - prepare buffer to load purgatory.
|
| 826 | * @pi: Purgatory to be loaded.
|
| 827 | * @kbuf: Buffer to setup.
|
| 828 | *
|
| 829 | * Allocates the memory needed for the buffer. Caller is responsible to free
|
| 830 | * the memory after use.
|
| 831 | *
|
| 832 | * Return: 0 on success, negative errno on error.
|
| 833 |
|
| 834 | static int kexec_purgatory_setup_kbuf(struct purgatory_info *pi,
|
| 835 | struct kexec_buf *kbuf)
|
| 836 | {
|
| 837 | const Elf_Shdr *sechdrs;
|
| 838 | unsigned long bss_align;
|
| 839 | unsigned long bss_sz;
|
| 840 | unsigned long align;
|
| 841 | int i, ret;
|
| 842 |
|
| 843 | sechdrs = (void *)pi->ehdr + pi->ehdr->e_shoff;
|
| 844 | kbuf->buf_align = bss_align = 1;
|
| 845 | kbuf->bufsz = bss_sz = 0;
|
| 846 |
|
| 847 | for (i = 0; i < pi->ehdr->e_shnum; i++) {
|
| 848 | if (!(sechdrs[i].sh_flags & SHF_ALLOC))
|
| 849 | continue;
|
| 850 |
|
| 851 | align = sechdrs[i].sh_addralign;
|
| 852 | if (sechdrs[i].sh_type != SHT_NOBITS) {
|
| 853 | if (kbuf->buf_align < align)
|
| 854 | kbuf->buf_align = align;
|
| 855 | kbuf->bufsz = ALIGN(kbuf->bufsz, align);
|
| 856 | kbuf->bufsz += sechdrs[i].sh_size;
|
| 857 | } else {
|
| 858 | if (bss_align < align)
|
| 859 | bss_align = align;
|
| 860 | bss_sz = ALIGN(bss_sz, align);
|
| 861 | bss_sz += sechdrs[i].sh_size;
|
| 862 | }
|
| 863 | }
|
| 864 | kbuf->bufsz = ALIGN(kbuf->bufsz, bss_align);
|
| 865 | kbuf->memsz = kbuf->bufsz + bss_sz;
|
| 866 | if (kbuf->buf_align < bss_align)
|
| 867 | kbuf->buf_align = bss_align;
|
| 868 |
|
| 869 | kbuf->buffer = vzalloc(kbuf->bufsz);
|
| 870 | if (!kbuf->buffer)
|
| 871 | return -ENOMEM;
|
| 872 | pi->purgatory_buf = kbuf->buffer;
|
| 873 |
|
| 874 | ret = kexec_add_buffer(kbuf);
|
| 875 | if (ret)
|
| 876 | goto out;
|
| 877 |
|
| 878 | return 0;
|
| 879 | out:
|
| 880 | vfree(pi->purgatory_buf);
|
| 881 | pi->purgatory_buf = NULL;
|
| 882 | return ret;
|
| 883 | }
|
| 884 |
|
| 885 | |
| 886 | * kexec_purgatory_setup_sechdrs - prepares the pi->sechdrs buffer.
|
| 887 | * @pi: Purgatory to be loaded.
|
| 888 | * @kbuf: Buffer prepared to store purgatory.
|
| 889 | *
|
| 890 | * Allocates the memory needed for the buffer. Caller is responsible to free
|
| 891 | * the memory after use.
|
| 892 | *
|
| 893 | * Return: 0 on success, negative errno on error.
|
| 894 |
|
| 895 | static int kexec_purgatory_setup_sechdrs(struct purgatory_info *pi,
|
| 896 | struct kexec_buf *kbuf)
|
| 897 | {
|
| 898 | unsigned long bss_addr;
|
| 899 | unsigned long offset;
|
| 900 | size_t sechdrs_size;
|
| 901 | Elf_Shdr *sechdrs;
|
| 902 | int i;
|
| 903 |
|
| 904 | |
| 905 | * The section headers in kexec_purgatory are read-only. In order to
|
| 906 | * have them modifiable make a temporary copy.
|
| 907 |
|
| 908 | sechdrs_size = array_size(sizeof(Elf_Shdr), pi->ehdr->e_shnum);
|
| 909 | sechdrs = vzalloc(sechdrs_size);
|
| 910 | if (!sechdrs)
|
| 911 | return -ENOMEM;
|
| 912 | memcpy(sechdrs, (void *)pi->ehdr + pi->ehdr->e_shoff, sechdrs_size);
|
| 913 | pi->sechdrs = sechdrs;
|
| 914 |
|
| 915 | offset = 0;
|
| 916 | bss_addr = kbuf->mem + kbuf->bufsz;
|
| 917 | kbuf->image->start = pi->ehdr->e_entry;
|
| 918 |
|
| 919 | for (i = 0; i < pi->ehdr->e_shnum; i++) {
|
| 920 | unsigned long align;
|
| 921 | void *src, *dst;
|
| 922 |
|
| 923 | if (!(sechdrs[i].sh_flags & SHF_ALLOC))
|
| 924 | continue;
|
| 925 |
|
| 926 | align = sechdrs[i].sh_addralign;
|
| 927 | if (sechdrs[i].sh_type == SHT_NOBITS) {
|
| 928 | bss_addr = ALIGN(bss_addr, align);
|
| 929 | sechdrs[i].sh_addr = bss_addr;
|
| 930 | bss_addr += sechdrs[i].sh_size;
|
| 931 | continue;
|
| 932 | }
|
| 933 |
|
| 934 | offset = ALIGN(offset, align);
|
| 935 |
|
| 936 | |
| 937 | * Check if the segment contains the entry point, if so,
|
| 938 | * calculate the value of image->start based on it.
|
| 939 | * If the compiler has produced more than one .text section
|
| 940 | * (Eg: .text.hot), they are generally after the main .text
|
| 941 | * section, and they shall not be used to calculate
|
| 942 | * image->start. So do not re-calculate image->start if it
|
| 943 | * is not set to the initial value, and warn the user so they
|
| 944 | * have a chance to fix their purgatory's linker script.
|
| 945 |
|
| 946 | if (sechdrs[i].sh_flags & SHF_EXECINSTR &&
|
| 947 | pi->ehdr->e_entry >= sechdrs[i].sh_addr &&
|
| 948 | pi->ehdr->e_entry < (sechdrs[i].sh_addr
|
| 949 | + sechdrs[i].sh_size) &&
|
| 950 | !WARN_ON(kbuf->image->start != pi->ehdr->e_entry)) {
|
| 951 | kbuf->image->start -= sechdrs[i].sh_addr;
|
| 952 | kbuf->image->start += kbuf->mem + offset;
|
| 953 | }
|
| 954 |
|
| 955 | src = (void *)pi->ehdr + sechdrs[i].sh_offset;
|
| 956 | dst = pi->purgatory_buf + offset;
|
| 957 | memcpy(dst, src, sechdrs[i].sh_size);
|
| 958 |
|
| 959 | sechdrs[i].sh_addr = kbuf->mem + offset;
|
| 960 | sechdrs[i].sh_offset = offset;
|
| 961 | offset += sechdrs[i].sh_size;
|
| 962 | }
|
| 963 |
|
| 964 | return 0;
|
| 965 | }
|
| 966 |
|
| 967 | static int kexec_apply_relocations(struct kimage *image)
|
| 968 | {
|
| 969 | int i, ret;
|
| 970 | struct purgatory_info *pi = &image->purgatory_info;
|
| 971 | const Elf_Shdr *sechdrs;
|
| 972 |
|
| 973 | sechdrs = (void *)pi->ehdr + pi->ehdr->e_shoff;
|
| 974 |
|
| 975 | for (i = 0; i < pi->ehdr->e_shnum; i++) {
|
| 976 | const Elf_Shdr *relsec;
|
| 977 | const Elf_Shdr *symtab;
|
| 978 | Elf_Shdr *section;
|
| 979 |
|
| 980 | relsec = sechdrs + i;
|
| 981 |
|
| 982 | if (relsec->sh_type != SHT_RELA &&
|
| 983 | relsec->sh_type != SHT_REL)
|
| 984 | continue;
|
| 985 |
|
| 986 | |
| 987 | * For section of type SHT_RELA/SHT_REL,
|
| 988 | * ->sh_link contains section header index of associated
|
| 989 | * symbol table. And ->sh_info contains section header
|
| 990 | * index of section to which relocations apply.
|
| 991 |
|
| 992 | if (relsec->sh_info >= pi->ehdr->e_shnum ||
|
| 993 | relsec->sh_link >= pi->ehdr->e_shnum)
|
| 994 | return -ENOEXEC;
|
| 995 |
|
| 996 | section = pi->sechdrs + relsec->sh_info;
|
| 997 | symtab = sechdrs + relsec->sh_link;
|
| 998 |
|
| 999 | if (!(section->sh_flags & SHF_ALLOC))
|
| 1000 | continue;
|
| 1001 |
|
| 1002 | |
| 1003 | * symtab->sh_link contain section header index of associated
|
| 1004 | * string table.
|
| 1005 |
|
| 1006 | if (symtab->sh_link >= pi->ehdr->e_shnum)
|
| 1007 |
|
| 1008 | continue;
|
| 1009 |
|
| 1010 | |
| 1011 | * Respective architecture needs to provide support for applying
|
| 1012 | * relocations of type SHT_RELA/SHT_REL.
|
| 1013 |
|
| 1014 | if (relsec->sh_type == SHT_RELA)
|
| 1015 | ret = arch_kexec_apply_relocations_add(pi, section,
|
| 1016 | relsec, symtab);
|
| 1017 | else if (relsec->sh_type == SHT_REL)
|
| 1018 | ret = arch_kexec_apply_relocations(pi, section,
|
| 1019 | relsec, symtab);
|
| 1020 | if (ret)
|
| 1021 | return ret;
|
| 1022 | }
|
| 1023 |
|
| 1024 | return 0;
|
| 1025 | }
|
| 1026 |
|
| 1027 | |
| 1028 | * kexec_load_purgatory - Load and relocate the purgatory object.
|
| 1029 | * @image: Image to add the purgatory to.
|
| 1030 | * @kbuf: Memory parameters to use.
|
| 1031 | *
|
| 1032 | * Allocates the memory needed for image->purgatory_info.sechdrs and
|
| 1033 | * image->purgatory_info.purgatory_buf/kbuf->buffer. Caller is responsible
|
| 1034 | * to free the memory after use.
|
| 1035 | *
|
| 1036 | * Return: 0 on success, negative errno on error.
|
| 1037 |
|
| 1038 | int kexec_load_purgatory(struct kimage *image, struct kexec_buf *kbuf)
|
| 1039 | {
|
| 1040 | struct purgatory_info *pi = &image->purgatory_info;
|
| 1041 | int ret;
|
| 1042 |
|
| 1043 | if (kexec_purgatory_size <= 0)
|
| 1044 | return -EINVAL;
|
| 1045 |
|
| 1046 | pi->ehdr = (const Elf_Ehdr *)kexec_purgatory;
|
| 1047 |
|
| 1048 | ret = kexec_purgatory_setup_kbuf(pi, kbuf);
|
| 1049 | if (ret)
|
| 1050 | return ret;
|
| 1051 |
|
| 1052 | ret = kexec_purgatory_setup_sechdrs(pi, kbuf);
|
| 1053 | if (ret)
|
| 1054 | goto out_free_kbuf;
|
| 1055 |
|
| 1056 | ret = kexec_apply_relocations(image);
|
| 1057 | if (ret)
|
| 1058 | goto out;
|
| 1059 |
|
| 1060 | return 0;
|
| 1061 | out:
|
| 1062 | vfree(pi->sechdrs);
|
| 1063 | pi->sechdrs = NULL;
|
| 1064 | out_free_kbuf:
|
| 1065 | vfree(pi->purgatory_buf);
|
| 1066 | pi->purgatory_buf = NULL;
|
| 1067 | return ret;
|
| 1068 | }
|
| 1069 |
|
| 1070 | |
| 1071 | * kexec_purgatory_find_symbol - find a symbol in the purgatory
|
| 1072 | * @pi: Purgatory to search in.
|
| 1073 | * @name: Name of the symbol.
|
| 1074 | *
|
| 1075 | * Return: pointer to symbol in read-only symtab on success, NULL on error.
|
| 1076 |
|
| 1077 | static const Elf_Sym *kexec_purgatory_find_symbol(struct purgatory_info *pi,
|
| 1078 | const char *name)
|
| 1079 | {
|
| 1080 | const Elf_Shdr *sechdrs;
|
| 1081 | const Elf_Ehdr *ehdr;
|
| 1082 | const Elf_Sym *syms;
|
| 1083 | const char *strtab;
|
| 1084 | int i, k;
|
| 1085 |
|
| 1086 | if (!pi->ehdr)
|
| 1087 | return NULL;
|
| 1088 |
|
| 1089 | ehdr = pi->ehdr;
|
| 1090 | sechdrs = (void *)ehdr + ehdr->e_shoff;
|
| 1091 |
|
| 1092 | for (i = 0; i < ehdr->e_shnum; i++) {
|
| 1093 | if (sechdrs[i].sh_type != SHT_SYMTAB)
|
| 1094 | continue;
|
| 1095 |
|
| 1096 | if (sechdrs[i].sh_link >= ehdr->e_shnum)
|
| 1097 |
|
| 1098 | continue;
|
| 1099 | strtab = (void *)ehdr + sechdrs[sechdrs[i].sh_link].sh_offset;
|
| 1100 | syms = (void *)ehdr + sechdrs[i].sh_offset;
|
| 1101 |
|
| 1102 |
|
| 1103 | for (k = 0; k < sechdrs[i].sh_size/sizeof(Elf_Sym); k++) {
|
| 1104 | if (ELF_ST_BIND(syms[k].st_info) != STB_GLOBAL)
|
| 1105 | continue;
|
| 1106 |
|
| 1107 | if (strcmp(strtab + syms[k].st_name, name) != 0)
|
| 1108 | continue;
|
| 1109 |
|
| 1110 | if (syms[k].st_shndx == SHN_UNDEF ||
|
| 1111 | syms[k].st_shndx >= ehdr->e_shnum) {
|
| 1112 | pr_debug("Symbol: %s has bad section index %d.\n",
|
| 1113 | name, syms[k].st_shndx);
|
| 1114 | return NULL;
|
| 1115 | }
|
| 1116 |
|
| 1117 |
|
| 1118 | return &syms[k];
|
| 1119 | }
|
| 1120 | }
|
| 1121 |
|
| 1122 | return NULL;
|
| 1123 | }
|
| 1124 |
|
| 1125 | void *kexec_purgatory_get_symbol_addr(struct kimage *image, const char *name)
|
| 1126 | {
|
| 1127 | struct purgatory_info *pi = &image->purgatory_info;
|
| 1128 | const Elf_Sym *sym;
|
| 1129 | Elf_Shdr *sechdr;
|
| 1130 |
|
| 1131 | sym = kexec_purgatory_find_symbol(pi, name);
|
| 1132 | if (!sym)
|
| 1133 | return ERR_PTR(-EINVAL);
|
| 1134 |
|
| 1135 | sechdr = &pi->sechdrs[sym->st_shndx];
|
| 1136 |
|
| 1137 | |
| 1138 | * Returns the address where symbol will finally be loaded after
|
| 1139 | * kexec_load_segment()
|
| 1140 |
|
| 1141 | return (void *)(sechdr->sh_addr + sym->st_value);
|
| 1142 | }
|
| 1143 |
|
| 1144 | |
| 1145 | * Get or set value of a symbol. If "get_value" is true, symbol value is
|
| 1146 | * returned in buf otherwise symbol value is set based on value in buf.
|
| 1147 |
|
| 1148 | int kexec_purgatory_get_set_symbol(struct kimage *image, const char *name,
|
| 1149 | void *buf, unsigned int size, bool get_value)
|
| 1150 | {
|
| 1151 | struct purgatory_info *pi = &image->purgatory_info;
|
| 1152 | const Elf_Sym *sym;
|
| 1153 | Elf_Shdr *sec;
|
| 1154 | char *sym_buf;
|
| 1155 |
|
| 1156 | sym = kexec_purgatory_find_symbol(pi, name);
|
| 1157 | if (!sym)
|
| 1158 | return -EINVAL;
|
| 1159 |
|
| 1160 | if (sym->st_size != size) {
|
| 1161 | pr_err("symbol %s size mismatch: expected %lu actual %u\n",
|
| 1162 | name, (unsigned long)sym->st_size, size);
|
| 1163 | return -EINVAL;
|
| 1164 | }
|
| 1165 |
|
| 1166 | sec = pi->sechdrs + sym->st_shndx;
|
| 1167 |
|
| 1168 | if (sec->sh_type == SHT_NOBITS) {
|
| 1169 | pr_err("symbol %s is in a bss section. Cannot %s\n", name,
|
| 1170 | get_value ? "get" : "set");
|
| 1171 | return -EINVAL;
|
| 1172 | }
|
| 1173 |
|
| 1174 | sym_buf = (char *)pi->purgatory_buf + sec->sh_offset + sym->st_value;
|
| 1175 |
|
| 1176 | if (get_value)
|
| 1177 | memcpy((void *)buf, sym_buf, size);
|
| 1178 | else
|
| 1179 | memcpy((void *)sym_buf, buf, size);
|
| 1180 |
|
| 1181 | return 0;
|
| 1182 | }
|
| 1183 | #endif
|