1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * fs/proc/vmcore.c Interface for accessing the crash 4 * dump from the system's previous life. 5 * Heavily borrowed from fs/proc/kcore.c 6 * Created by: Hariprasad Nellitheertha (hari@in.ibm.com) 7 * Copyright (C) IBM Corporation, 2004. All rights reserved 8 * 9 */ 10 11 #include <linux/mm.h> 12 #include <linux/kcore.h> 13 #include <linux/user.h> 14 #include <linux/elf.h> 15 #include <linux/elfcore.h> 16 #include <linux/export.h> 17 #include <linux/slab.h> 18 #include <linux/highmem.h> 19 #include <linux/printk.h> 20 #include <linux/memblock.h> 21 #include <linux/init.h> 22 #include <linux/crash_dump.h> 23 #include <linux/list.h> 24 #include <linux/moduleparam.h> 25 #include <linux/mutex.h> 26 #include <linux/vmalloc.h> 27 #include <linux/pagemap.h> 28 #include <linux/uio.h> 29 #include <linux/cc_platform.h> 30 #include <asm/io.h> 31 #include "internal.h" 32 33 /* List representing chunks of contiguous memory areas and their offsets in 34 * vmcore file. 35 */ 36 static LIST_HEAD(vmcore_list); 37 38 /* Stores the pointer to the buffer containing kernel elf core headers. */ 39 static char *elfcorebuf; 40 static size_t elfcorebuf_sz; 41 static size_t elfcorebuf_sz_orig; 42 43 static char *elfnotes_buf; 44 static size_t elfnotes_sz; 45 /* Size of all notes minus the device dump notes */ 46 static size_t elfnotes_orig_sz; 47 48 /* Total size of vmcore file. */ 49 static u64 vmcore_size; 50 51 static struct proc_dir_entry *proc_vmcore; 52 53 #ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP 54 /* Device Dump list and mutex to synchronize access to list */ 55 static LIST_HEAD(vmcoredd_list); 56 static DEFINE_MUTEX(vmcoredd_mutex); 57 58 static bool vmcoredd_disabled; 59 core_param(novmcoredd, vmcoredd_disabled, bool, 0); 60 #endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */ 61 62 /* Device Dump Size */ 63 static size_t vmcoredd_orig_sz; 64 65 static DEFINE_SPINLOCK(vmcore_cb_lock); 66 DEFINE_STATIC_SRCU(vmcore_cb_srcu); 67 /* List of registered vmcore callbacks. */ 68 static LIST_HEAD(vmcore_cb_list); 69 /* Whether the vmcore has been opened once. */ 70 static bool vmcore_opened; 71 72 void register_vmcore_cb(struct vmcore_cb *cb) 73 { 74 INIT_LIST_HEAD(&cb->next); 75 spin_lock(&vmcore_cb_lock); 76 list_add_tail(&cb->next, &vmcore_cb_list); 77 /* 78 * Registering a vmcore callback after the vmcore was opened is 79 * very unusual (e.g., manual driver loading). 80 */ 81 if (vmcore_opened) 82 pr_warn_once("Unexpected vmcore callback registration\n"); 83 spin_unlock(&vmcore_cb_lock); 84 } 85 EXPORT_SYMBOL_GPL(register_vmcore_cb); 86 87 void unregister_vmcore_cb(struct vmcore_cb *cb) 88 { 89 spin_lock(&vmcore_cb_lock); 90 list_del_rcu(&cb->next); 91 /* 92 * Unregistering a vmcore callback after the vmcore was opened is 93 * very unusual (e.g., forced driver removal), but we cannot stop 94 * unregistering. 95 */ 96 if (vmcore_opened) 97 pr_warn_once("Unexpected vmcore callback unregistration\n"); 98 spin_unlock(&vmcore_cb_lock); 99 100 synchronize_srcu(&vmcore_cb_srcu); 101 } 102 EXPORT_SYMBOL_GPL(unregister_vmcore_cb); 103 104 static bool pfn_is_ram(unsigned long pfn) 105 { 106 struct vmcore_cb *cb; 107 bool ret = true; 108 109 list_for_each_entry_srcu(cb, &vmcore_cb_list, next, 110 srcu_read_lock_held(&vmcore_cb_srcu)) { 111 if (unlikely(!cb->pfn_is_ram)) 112 continue; 113 ret = cb->pfn_is_ram(cb, pfn); 114 if (!ret) 115 break; 116 } 117 118 return ret; 119 } 120 121 static int open_vmcore(struct inode *inode, struct file *file) 122 { 123 spin_lock(&vmcore_cb_lock); 124 vmcore_opened = true; 125 spin_unlock(&vmcore_cb_lock); 126 127 return 0; 128 } 129 130 /* Reads a page from the oldmem device from given offset. */ 131 ssize_t read_from_oldmem(struct iov_iter *iter, size_t count, 132 u64 *ppos, bool encrypted) 133 { 134 unsigned long pfn, offset; 135 size_t nr_bytes; 136 ssize_t read = 0, tmp; 137 int idx; 138 139 if (!count) 140 return 0; 141 142 offset = (unsigned long)(*ppos % PAGE_SIZE); 143 pfn = (unsigned long)(*ppos / PAGE_SIZE); 144 145 idx = srcu_read_lock(&vmcore_cb_srcu); 146 do { 147 if (count > (PAGE_SIZE - offset)) 148 nr_bytes = PAGE_SIZE - offset; 149 else 150 nr_bytes = count; 151 152 /* If pfn is not ram, return zeros for sparse dump files */ 153 if (!pfn_is_ram(pfn)) { 154 tmp = iov_iter_zero(nr_bytes, iter); 155 } else { 156 if (encrypted) 157 tmp = copy_oldmem_page_encrypted(iter, pfn, 158 nr_bytes, 159 offset); 160 else 161 tmp = copy_oldmem_page(iter, pfn, nr_bytes, 162 offset); 163 } 164 if (tmp < nr_bytes) { 165 srcu_read_unlock(&vmcore_cb_srcu, idx); 166 return -EFAULT; 167 } 168 169 *ppos += nr_bytes; 170 count -= nr_bytes; 171 read += nr_bytes; 172 ++pfn; 173 offset = 0; 174 } while (count); 175 srcu_read_unlock(&vmcore_cb_srcu, idx); 176 177 return read; 178 } 179 180 /* 181 * Architectures may override this function to allocate ELF header in 2nd kernel 182 */ 183 int __weak elfcorehdr_alloc(unsigned long long *addr, unsigned long long *size) 184 { 185 return 0; 186 } 187 188 /* 189 * Architectures may override this function to free header 190 */ 191 void __weak elfcorehdr_free(unsigned long long addr) 192 {} 193 194 /* 195 * Architectures may override this function to read from ELF header 196 */ 197 ssize_t __weak elfcorehdr_read(char *buf, size_t count, u64 *ppos) 198 { 199 struct kvec kvec = { .iov_base = buf, .iov_len = count }; 200 struct iov_iter iter; 201 202 iov_iter_kvec(&iter, ITER_DEST, &kvec, 1, count); 203 204 return read_from_oldmem(&iter, count, ppos, false); 205 } 206 207 /* 208 * Architectures may override this function to read from notes sections 209 */ 210 ssize_t __weak elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos) 211 { 212 struct kvec kvec = { .iov_base = buf, .iov_len = count }; 213 struct iov_iter iter; 214 215 iov_iter_kvec(&iter, ITER_DEST, &kvec, 1, count); 216 217 return read_from_oldmem(&iter, count, ppos, 218 cc_platform_has(CC_ATTR_MEM_ENCRYPT)); 219 } 220 221 /* 222 * Architectures may override this function to map oldmem 223 */ 224 int __weak remap_oldmem_pfn_range(struct vm_area_struct *vma, 225 unsigned long from, unsigned long pfn, 226 unsigned long size, pgprot_t prot) 227 { 228 prot = pgprot_encrypted(prot); 229 return remap_pfn_range(vma, from, pfn, size, prot); 230 } 231 232 /* 233 * Architectures which support memory encryption override this. 234 */ 235 ssize_t __weak copy_oldmem_page_encrypted(struct iov_iter *iter, 236 unsigned long pfn, size_t csize, unsigned long offset) 237 { 238 return copy_oldmem_page(iter, pfn, csize, offset); 239 } 240 241 #ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP 242 static int vmcoredd_copy_dumps(struct iov_iter *iter, u64 start, size_t size) 243 { 244 struct vmcoredd_node *dump; 245 u64 offset = 0; 246 int ret = 0; 247 size_t tsz; 248 char *buf; 249 250 mutex_lock(&vmcoredd_mutex); 251 list_for_each_entry(dump, &vmcoredd_list, list) { 252 if (start < offset + dump->size) { 253 tsz = min(offset + (u64)dump->size - start, (u64)size); 254 buf = dump->buf + start - offset; 255 if (copy_to_iter(buf, tsz, iter) < tsz) { 256 ret = -EFAULT; 257 goto out_unlock; 258 } 259 260 size -= tsz; 261 start += tsz; 262 263 /* Leave now if buffer filled already */ 264 if (!size) 265 goto out_unlock; 266 } 267 offset += dump->size; 268 } 269 270 out_unlock: 271 mutex_unlock(&vmcoredd_mutex); 272 return ret; 273 } 274 275 #ifdef CONFIG_MMU 276 static int vmcoredd_mmap_dumps(struct vm_area_struct *vma, unsigned long dst, 277 u64 start, size_t size) 278 { 279 struct vmcoredd_node *dump; 280 u64 offset = 0; 281 int ret = 0; 282 size_t tsz; 283 char *buf; 284 285 mutex_lock(&vmcoredd_mutex); 286 list_for_each_entry(dump, &vmcoredd_list, list) { 287 if (start < offset + dump->size) { 288 tsz = min(offset + (u64)dump->size - start, (u64)size); 289 buf = dump->buf + start - offset; 290 if (remap_vmalloc_range_partial(vma, dst, buf, 0, 291 tsz)) { 292 ret = -EFAULT; 293 goto out_unlock; 294 } 295 296 size -= tsz; 297 start += tsz; 298 dst += tsz; 299 300 /* Leave now if buffer filled already */ 301 if (!size) 302 goto out_unlock; 303 } 304 offset += dump->size; 305 } 306 307 out_unlock: 308 mutex_unlock(&vmcoredd_mutex); 309 return ret; 310 } 311 #endif /* CONFIG_MMU */ 312 #endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */ 313 314 /* Read from the ELF header and then the crash dump. On error, negative value is 315 * returned otherwise number of bytes read are returned. 316 */ 317 static ssize_t __read_vmcore(struct iov_iter *iter, loff_t *fpos) 318 { 319 ssize_t acc = 0, tmp; 320 size_t tsz; 321 u64 start; 322 struct vmcore *m = NULL; 323 324 if (!iov_iter_count(iter) || *fpos >= vmcore_size) 325 return 0; 326 327 iov_iter_truncate(iter, vmcore_size - *fpos); 328 329 /* Read ELF core header */ 330 if (*fpos < elfcorebuf_sz) { 331 tsz = min(elfcorebuf_sz - (size_t)*fpos, iov_iter_count(iter)); 332 if (copy_to_iter(elfcorebuf + *fpos, tsz, iter) < tsz) 333 return -EFAULT; 334 *fpos += tsz; 335 acc += tsz; 336 337 /* leave now if filled buffer already */ 338 if (!iov_iter_count(iter)) 339 return acc; 340 } 341 342 /* Read ELF note segment */ 343 if (*fpos < elfcorebuf_sz + elfnotes_sz) { 344 void *kaddr; 345 346 /* We add device dumps before other elf notes because the 347 * other elf notes may not fill the elf notes buffer 348 * completely and we will end up with zero-filled data 349 * between the elf notes and the device dumps. Tools will 350 * then try to decode this zero-filled data as valid notes 351 * and we don't want that. Hence, adding device dumps before 352 * the other elf notes ensure that zero-filled data can be 353 * avoided. 354 */ 355 #ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP 356 /* Read device dumps */ 357 if (*fpos < elfcorebuf_sz + vmcoredd_orig_sz) { 358 tsz = min(elfcorebuf_sz + vmcoredd_orig_sz - 359 (size_t)*fpos, iov_iter_count(iter)); 360 start = *fpos - elfcorebuf_sz; 361 if (vmcoredd_copy_dumps(iter, start, tsz)) 362 return -EFAULT; 363 364 *fpos += tsz; 365 acc += tsz; 366 367 /* leave now if filled buffer already */ 368 if (!iov_iter_count(iter)) 369 return acc; 370 } 371 #endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */ 372 373 /* Read remaining elf notes */ 374 tsz = min(elfcorebuf_sz + elfnotes_sz - (size_t)*fpos, 375 iov_iter_count(iter)); 376 kaddr = elfnotes_buf + *fpos - elfcorebuf_sz - vmcoredd_orig_sz; 377 if (copy_to_iter(kaddr, tsz, iter) < tsz) 378 return -EFAULT; 379 380 *fpos += tsz; 381 acc += tsz; 382 383 /* leave now if filled buffer already */ 384 if (!iov_iter_count(iter)) 385 return acc; 386 } 387 388 list_for_each_entry(m, &vmcore_list, list) { 389 if (*fpos < m->offset + m->size) { 390 tsz = (size_t)min_t(unsigned long long, 391 m->offset + m->size - *fpos, 392 iov_iter_count(iter)); 393 start = m->paddr + *fpos - m->offset; 394 tmp = read_from_oldmem(iter, tsz, &start, 395 cc_platform_has(CC_ATTR_MEM_ENCRYPT)); 396 if (tmp < 0) 397 return tmp; 398 *fpos += tsz; 399 acc += tsz; 400 401 /* leave now if filled buffer already */ 402 if (!iov_iter_count(iter)) 403 return acc; 404 } 405 } 406 407 return acc; 408 } 409 410 static ssize_t read_vmcore(struct kiocb *iocb, struct iov_iter *iter) 411 { 412 return __read_vmcore(iter, &iocb->ki_pos); 413 } 414 415 /* 416 * The vmcore fault handler uses the page cache and fills data using the 417 * standard __read_vmcore() function. 418 * 419 * On s390 the fault handler is used for memory regions that can't be mapped 420 * directly with remap_pfn_range(). 421 */ 422 static vm_fault_t mmap_vmcore_fault(struct vm_fault *vmf) 423 { 424 #ifdef CONFIG_S390 425 struct address_space *mapping = vmf->vma->vm_file->f_mapping; 426 pgoff_t index = vmf->pgoff; 427 struct iov_iter iter; 428 struct kvec kvec; 429 struct page *page; 430 loff_t offset; 431 int rc; 432 433 page = find_or_create_page(mapping, index, GFP_KERNEL); 434 if (!page) 435 return VM_FAULT_OOM; 436 if (!PageUptodate(page)) { 437 offset = (loff_t) index << PAGE_SHIFT; 438 kvec.iov_base = page_address(page); 439 kvec.iov_len = PAGE_SIZE; 440 iov_iter_kvec(&iter, ITER_DEST, &kvec, 1, PAGE_SIZE); 441 442 rc = __read_vmcore(&iter, &offset); 443 if (rc < 0) { 444 unlock_page(page); 445 put_page(page); 446 return vmf_error(rc); 447 } 448 SetPageUptodate(page); 449 } 450 unlock_page(page); 451 vmf->page = page; 452 return 0; 453 #else 454 return VM_FAULT_SIGBUS; 455 #endif 456 } 457 458 static const struct vm_operations_struct vmcore_mmap_ops = { 459 .fault = mmap_vmcore_fault, 460 }; 461 462 /** 463 * vmcore_alloc_buf - allocate buffer in vmalloc memory 464 * @size: size of buffer 465 * 466 * If CONFIG_MMU is defined, use vmalloc_user() to allow users to mmap 467 * the buffer to user-space by means of remap_vmalloc_range(). 468 * 469 * If CONFIG_MMU is not defined, use vzalloc() since mmap_vmcore() is 470 * disabled and there's no need to allow users to mmap the buffer. 471 */ 472 static inline char *vmcore_alloc_buf(size_t size) 473 { 474 #ifdef CONFIG_MMU 475 return vmalloc_user(size); 476 #else 477 return vzalloc(size); 478 #endif 479 } 480 481 /* 482 * Disable mmap_vmcore() if CONFIG_MMU is not defined. MMU is 483 * essential for mmap_vmcore() in order to map physically 484 * non-contiguous objects (ELF header, ELF note segment and memory 485 * regions in the 1st kernel pointed to by PT_LOAD entries) into 486 * virtually contiguous user-space in ELF layout. 487 */ 488 #ifdef CONFIG_MMU 489 /* 490 * remap_oldmem_pfn_checked - do remap_oldmem_pfn_range replacing all pages 491 * reported as not being ram with the zero page. 492 * 493 * @vma: vm_area_struct describing requested mapping 494 * @from: start remapping from 495 * @pfn: page frame number to start remapping to 496 * @size: remapping size 497 * @prot: protection bits 498 * 499 * Returns zero on success, -EAGAIN on failure. 500 */ 501 static int remap_oldmem_pfn_checked(struct vm_area_struct *vma, 502 unsigned long from, unsigned long pfn, 503 unsigned long size, pgprot_t prot) 504 { 505 unsigned long map_size; 506 unsigned long pos_start, pos_end, pos; 507 unsigned long zeropage_pfn = my_zero_pfn(0); 508 size_t len = 0; 509 510 pos_start = pfn; 511 pos_end = pfn + (size >> PAGE_SHIFT); 512 513 for (pos = pos_start; pos < pos_end; ++pos) { 514 if (!pfn_is_ram(pos)) { 515 /* 516 * We hit a page which is not ram. Remap the continuous 517 * region between pos_start and pos-1 and replace 518 * the non-ram page at pos with the zero page. 519 */ 520 if (pos > pos_start) { 521 /* Remap continuous region */ 522 map_size = (pos - pos_start) << PAGE_SHIFT; 523 if (remap_oldmem_pfn_range(vma, from + len, 524 pos_start, map_size, 525 prot)) 526 goto fail; 527 len += map_size; 528 } 529 /* Remap the zero page */ 530 if (remap_oldmem_pfn_range(vma, from + len, 531 zeropage_pfn, 532 PAGE_SIZE, prot)) 533 goto fail; 534 len += PAGE_SIZE; 535 pos_start = pos + 1; 536 } 537 } 538 if (pos > pos_start) { 539 /* Remap the rest */ 540 map_size = (pos - pos_start) << PAGE_SHIFT; 541 if (remap_oldmem_pfn_range(vma, from + len, pos_start, 542 map_size, prot)) 543 goto fail; 544 } 545 return 0; 546 fail: 547 do_munmap(vma->vm_mm, from, len, NULL); 548 return -EAGAIN; 549 } 550 551 static int vmcore_remap_oldmem_pfn(struct vm_area_struct *vma, 552 unsigned long from, unsigned long pfn, 553 unsigned long size, pgprot_t prot) 554 { 555 int ret, idx; 556 557 /* 558 * Check if a callback was registered to avoid looping over all 559 * pages without a reason. 560 */ 561 idx = srcu_read_lock(&vmcore_cb_srcu); 562 if (!list_empty(&vmcore_cb_list)) 563 ret = remap_oldmem_pfn_checked(vma, from, pfn, size, prot); 564 else 565 ret = remap_oldmem_pfn_range(vma, from, pfn, size, prot); 566 srcu_read_unlock(&vmcore_cb_srcu, idx); 567 return ret; 568 } 569 570 static int mmap_vmcore(struct file *file, struct vm_area_struct *vma) 571 { 572 size_t size = vma->vm_end - vma->vm_start; 573 u64 start, end, len, tsz; 574 struct vmcore *m; 575 576 start = (u64)vma->vm_pgoff << PAGE_SHIFT; 577 end = start + size; 578 579 if (size > vmcore_size || end > vmcore_size) 580 return -EINVAL; 581 582 if (vma->vm_flags & (VM_WRITE | VM_EXEC)) 583 return -EPERM; 584 585 vm_flags_mod(vma, VM_MIXEDMAP, VM_MAYWRITE | VM_MAYEXEC); 586 vma->vm_ops = &vmcore_mmap_ops; 587 588 len = 0; 589 590 if (start < elfcorebuf_sz) { 591 u64 pfn; 592 593 tsz = min(elfcorebuf_sz - (size_t)start, size); 594 pfn = __pa(elfcorebuf + start) >> PAGE_SHIFT; 595 if (remap_pfn_range(vma, vma->vm_start, pfn, tsz, 596 vma->vm_page_prot)) 597 return -EAGAIN; 598 size -= tsz; 599 start += tsz; 600 len += tsz; 601 602 if (size == 0) 603 return 0; 604 } 605 606 if (start < elfcorebuf_sz + elfnotes_sz) { 607 void *kaddr; 608 609 /* We add device dumps before other elf notes because the 610 * other elf notes may not fill the elf notes buffer 611 * completely and we will end up with zero-filled data 612 * between the elf notes and the device dumps. Tools will 613 * then try to decode this zero-filled data as valid notes 614 * and we don't want that. Hence, adding device dumps before 615 * the other elf notes ensure that zero-filled data can be 616 * avoided. This also ensures that the device dumps and 617 * other elf notes can be properly mmaped at page aligned 618 * address. 619 */ 620 #ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP 621 /* Read device dumps */ 622 if (start < elfcorebuf_sz + vmcoredd_orig_sz) { 623 u64 start_off; 624 625 tsz = min(elfcorebuf_sz + vmcoredd_orig_sz - 626 (size_t)start, size); 627 start_off = start - elfcorebuf_sz; 628 if (vmcoredd_mmap_dumps(vma, vma->vm_start + len, 629 start_off, tsz)) 630 goto fail; 631 632 size -= tsz; 633 start += tsz; 634 len += tsz; 635 636 /* leave now if filled buffer already */ 637 if (!size) 638 return 0; 639 } 640 #endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */ 641 642 /* Read remaining elf notes */ 643 tsz = min(elfcorebuf_sz + elfnotes_sz - (size_t)start, size); 644 kaddr = elfnotes_buf + start - elfcorebuf_sz - vmcoredd_orig_sz; 645 if (remap_vmalloc_range_partial(vma, vma->vm_start + len, 646 kaddr, 0, tsz)) 647 goto fail; 648 649 size -= tsz; 650 start += tsz; 651 len += tsz; 652 653 if (size == 0) 654 return 0; 655 } 656 657 list_for_each_entry(m, &vmcore_list, list) { 658 if (start < m->offset + m->size) { 659 u64 paddr = 0; 660 661 tsz = (size_t)min_t(unsigned long long, 662 m->offset + m->size - start, size); 663 paddr = m->paddr + start - m->offset; 664 if (vmcore_remap_oldmem_pfn(vma, vma->vm_start + len, 665 paddr >> PAGE_SHIFT, tsz, 666 vma->vm_page_prot)) 667 goto fail; 668 size -= tsz; 669 start += tsz; 670 len += tsz; 671 672 if (size == 0) 673 return 0; 674 } 675 } 676 677 return 0; 678 fail: 679 do_munmap(vma->vm_mm, vma->vm_start, len, NULL); 680 return -EAGAIN; 681 } 682 #else 683 static int mmap_vmcore(struct file *file, struct vm_area_struct *vma) 684 { 685 return -ENOSYS; 686 } 687 #endif 688 689 static const struct proc_ops vmcore_proc_ops = { 690 .proc_open = open_vmcore, 691 .proc_read_iter = read_vmcore, 692 .proc_lseek = default_llseek, 693 .proc_mmap = mmap_vmcore, 694 }; 695 696 static struct vmcore* __init get_new_element(void) 697 { 698 return kzalloc(sizeof(struct vmcore), GFP_KERNEL); 699 } 700 701 static u64 get_vmcore_size(size_t elfsz, size_t elfnotesegsz, 702 struct list_head *vc_list) 703 { 704 u64 size; 705 struct vmcore *m; 706 707 size = elfsz + elfnotesegsz; 708 list_for_each_entry(m, vc_list, list) { 709 size += m->size; 710 } 711 return size; 712 } 713 714 /** 715 * update_note_header_size_elf64 - update p_memsz member of each PT_NOTE entry 716 * 717 * @ehdr_ptr: ELF header 718 * 719 * This function updates p_memsz member of each PT_NOTE entry in the 720 * program header table pointed to by @ehdr_ptr to real size of ELF 721 * note segment. 722 */ 723 static int __init update_note_header_size_elf64(const Elf64_Ehdr *ehdr_ptr) 724 { 725 int i, rc=0; 726 Elf64_Phdr *phdr_ptr; 727 Elf64_Nhdr *nhdr_ptr; 728 729 phdr_ptr = (Elf64_Phdr *)(ehdr_ptr + 1); 730 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { 731 void *notes_section; 732 u64 offset, max_sz, sz, real_sz = 0; 733 if (phdr_ptr->p_type != PT_NOTE) 734 continue; 735 max_sz = phdr_ptr->p_memsz; 736 offset = phdr_ptr->p_offset; 737 notes_section = kmalloc(max_sz, GFP_KERNEL); 738 if (!notes_section) 739 return -ENOMEM; 740 rc = elfcorehdr_read_notes(notes_section, max_sz, &offset); 741 if (rc < 0) { 742 kfree(notes_section); 743 return rc; 744 } 745 nhdr_ptr = notes_section; 746 while (nhdr_ptr->n_namesz != 0) { 747 sz = sizeof(Elf64_Nhdr) + 748 (((u64)nhdr_ptr->n_namesz + 3) & ~3) + 749 (((u64)nhdr_ptr->n_descsz + 3) & ~3); 750 if ((real_sz + sz) > max_sz) { 751 pr_warn("Warning: Exceeded p_memsz, dropping PT_NOTE entry n_namesz=0x%x, n_descsz=0x%x\n", 752 nhdr_ptr->n_namesz, nhdr_ptr->n_descsz); 753 break; 754 } 755 real_sz += sz; 756 nhdr_ptr = (Elf64_Nhdr*)((char*)nhdr_ptr + sz); 757 } 758 kfree(notes_section); 759 phdr_ptr->p_memsz = real_sz; 760 if (real_sz == 0) { 761 pr_warn("Warning: Zero PT_NOTE entries found\n"); 762 } 763 } 764 765 return 0; 766 } 767 768 /** 769 * get_note_number_and_size_elf64 - get the number of PT_NOTE program 770 * headers and sum of real size of their ELF note segment headers and 771 * data. 772 * 773 * @ehdr_ptr: ELF header 774 * @nr_ptnote: buffer for the number of PT_NOTE program headers 775 * @sz_ptnote: buffer for size of unique PT_NOTE program header 776 * 777 * This function is used to merge multiple PT_NOTE program headers 778 * into a unique single one. The resulting unique entry will have 779 * @sz_ptnote in its phdr->p_mem. 780 * 781 * It is assumed that program headers with PT_NOTE type pointed to by 782 * @ehdr_ptr has already been updated by update_note_header_size_elf64 783 * and each of PT_NOTE program headers has actual ELF note segment 784 * size in its p_memsz member. 785 */ 786 static int __init get_note_number_and_size_elf64(const Elf64_Ehdr *ehdr_ptr, 787 int *nr_ptnote, u64 *sz_ptnote) 788 { 789 int i; 790 Elf64_Phdr *phdr_ptr; 791 792 *nr_ptnote = *sz_ptnote = 0; 793 794 phdr_ptr = (Elf64_Phdr *)(ehdr_ptr + 1); 795 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { 796 if (phdr_ptr->p_type != PT_NOTE) 797 continue; 798 *nr_ptnote += 1; 799 *sz_ptnote += phdr_ptr->p_memsz; 800 } 801 802 return 0; 803 } 804 805 /** 806 * copy_notes_elf64 - copy ELF note segments in a given buffer 807 * 808 * @ehdr_ptr: ELF header 809 * @notes_buf: buffer into which ELF note segments are copied 810 * 811 * This function is used to copy ELF note segment in the 1st kernel 812 * into the buffer @notes_buf in the 2nd kernel. It is assumed that 813 * size of the buffer @notes_buf is equal to or larger than sum of the 814 * real ELF note segment headers and data. 815 * 816 * It is assumed that program headers with PT_NOTE type pointed to by 817 * @ehdr_ptr has already been updated by update_note_header_size_elf64 818 * and each of PT_NOTE program headers has actual ELF note segment 819 * size in its p_memsz member. 820 */ 821 static int __init copy_notes_elf64(const Elf64_Ehdr *ehdr_ptr, char *notes_buf) 822 { 823 int i, rc=0; 824 Elf64_Phdr *phdr_ptr; 825 826 phdr_ptr = (Elf64_Phdr*)(ehdr_ptr + 1); 827 828 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { 829 u64 offset; 830 if (phdr_ptr->p_type != PT_NOTE) 831 continue; 832 offset = phdr_ptr->p_offset; 833 rc = elfcorehdr_read_notes(notes_buf, phdr_ptr->p_memsz, 834 &offset); 835 if (rc < 0) 836 return rc; 837 notes_buf += phdr_ptr->p_memsz; 838 } 839 840 return 0; 841 } 842 843 /* Merges all the PT_NOTE headers into one. */ 844 static int __init merge_note_headers_elf64(char *elfptr, size_t *elfsz, 845 char **notes_buf, size_t *notes_sz) 846 { 847 int i, nr_ptnote=0, rc=0; 848 char *tmp; 849 Elf64_Ehdr *ehdr_ptr; 850 Elf64_Phdr phdr; 851 u64 phdr_sz = 0, note_off; 852 853 ehdr_ptr = (Elf64_Ehdr *)elfptr; 854 855 rc = update_note_header_size_elf64(ehdr_ptr); 856 if (rc < 0) 857 return rc; 858 859 rc = get_note_number_and_size_elf64(ehdr_ptr, &nr_ptnote, &phdr_sz); 860 if (rc < 0) 861 return rc; 862 863 *notes_sz = roundup(phdr_sz, PAGE_SIZE); 864 *notes_buf = vmcore_alloc_buf(*notes_sz); 865 if (!*notes_buf) 866 return -ENOMEM; 867 868 rc = copy_notes_elf64(ehdr_ptr, *notes_buf); 869 if (rc < 0) 870 return rc; 871 872 /* Prepare merged PT_NOTE program header. */ 873 phdr.p_type = PT_NOTE; 874 phdr.p_flags = 0; 875 note_off = sizeof(Elf64_Ehdr) + 876 (ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf64_Phdr); 877 phdr.p_offset = roundup(note_off, PAGE_SIZE); 878 phdr.p_vaddr = phdr.p_paddr = 0; 879 phdr.p_filesz = phdr.p_memsz = phdr_sz; 880 phdr.p_align = 4; 881 882 /* Add merged PT_NOTE program header*/ 883 tmp = elfptr + sizeof(Elf64_Ehdr); 884 memcpy(tmp, &phdr, sizeof(phdr)); 885 tmp += sizeof(phdr); 886 887 /* Remove unwanted PT_NOTE program headers. */ 888 i = (nr_ptnote - 1) * sizeof(Elf64_Phdr); 889 *elfsz = *elfsz - i; 890 memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf64_Ehdr)-sizeof(Elf64_Phdr))); 891 memset(elfptr + *elfsz, 0, i); 892 *elfsz = roundup(*elfsz, PAGE_SIZE); 893 894 /* Modify e_phnum to reflect merged headers. */ 895 ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1; 896 897 /* Store the size of all notes. We need this to update the note 898 * header when the device dumps will be added. 899 */ 900 elfnotes_orig_sz = phdr.p_memsz; 901 902 return 0; 903 } 904 905 /** 906 * update_note_header_size_elf32 - update p_memsz member of each PT_NOTE entry 907 * 908 * @ehdr_ptr: ELF header 909 * 910 * This function updates p_memsz member of each PT_NOTE entry in the 911 * program header table pointed to by @ehdr_ptr to real size of ELF 912 * note segment. 913 */ 914 static int __init update_note_header_size_elf32(const Elf32_Ehdr *ehdr_ptr) 915 { 916 int i, rc=0; 917 Elf32_Phdr *phdr_ptr; 918 Elf32_Nhdr *nhdr_ptr; 919 920 phdr_ptr = (Elf32_Phdr *)(ehdr_ptr + 1); 921 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { 922 void *notes_section; 923 u64 offset, max_sz, sz, real_sz = 0; 924 if (phdr_ptr->p_type != PT_NOTE) 925 continue; 926 max_sz = phdr_ptr->p_memsz; 927 offset = phdr_ptr->p_offset; 928 notes_section = kmalloc(max_sz, GFP_KERNEL); 929 if (!notes_section) 930 return -ENOMEM; 931 rc = elfcorehdr_read_notes(notes_section, max_sz, &offset); 932 if (rc < 0) { 933 kfree(notes_section); 934 return rc; 935 } 936 nhdr_ptr = notes_section; 937 while (nhdr_ptr->n_namesz != 0) { 938 sz = sizeof(Elf32_Nhdr) + 939 (((u64)nhdr_ptr->n_namesz + 3) & ~3) + 940 (((u64)nhdr_ptr->n_descsz + 3) & ~3); 941 if ((real_sz + sz) > max_sz) { 942 pr_warn("Warning: Exceeded p_memsz, dropping PT_NOTE entry n_namesz=0x%x, n_descsz=0x%x\n", 943 nhdr_ptr->n_namesz, nhdr_ptr->n_descsz); 944 break; 945 } 946 real_sz += sz; 947 nhdr_ptr = (Elf32_Nhdr*)((char*)nhdr_ptr + sz); 948 } 949 kfree(notes_section); 950 phdr_ptr->p_memsz = real_sz; 951 if (real_sz == 0) { 952 pr_warn("Warning: Zero PT_NOTE entries found\n"); 953 } 954 } 955 956 return 0; 957 } 958 959 /** 960 * get_note_number_and_size_elf32 - get the number of PT_NOTE program 961 * headers and sum of real size of their ELF note segment headers and 962 * data. 963 * 964 * @ehdr_ptr: ELF header 965 * @nr_ptnote: buffer for the number of PT_NOTE program headers 966 * @sz_ptnote: buffer for size of unique PT_NOTE program header 967 * 968 * This function is used to merge multiple PT_NOTE program headers 969 * into a unique single one. The resulting unique entry will have 970 * @sz_ptnote in its phdr->p_mem. 971 * 972 * It is assumed that program headers with PT_NOTE type pointed to by 973 * @ehdr_ptr has already been updated by update_note_header_size_elf32 974 * and each of PT_NOTE program headers has actual ELF note segment 975 * size in its p_memsz member. 976 */ 977 static int __init get_note_number_and_size_elf32(const Elf32_Ehdr *ehdr_ptr, 978 int *nr_ptnote, u64 *sz_ptnote) 979 { 980 int i; 981 Elf32_Phdr *phdr_ptr; 982 983 *nr_ptnote = *sz_ptnote = 0; 984 985 phdr_ptr = (Elf32_Phdr *)(ehdr_ptr + 1); 986 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { 987 if (phdr_ptr->p_type != PT_NOTE) 988 continue; 989 *nr_ptnote += 1; 990 *sz_ptnote += phdr_ptr->p_memsz; 991 } 992 993 return 0; 994 } 995 996 /** 997 * copy_notes_elf32 - copy ELF note segments in a given buffer 998 * 999 * @ehdr_ptr: ELF header 1000 * @notes_buf: buffer into which ELF note segments are copied 1001 * 1002 * This function is used to copy ELF note segment in the 1st kernel 1003 * into the buffer @notes_buf in the 2nd kernel. It is assumed that 1004 * size of the buffer @notes_buf is equal to or larger than sum of the 1005 * real ELF note segment headers and data. 1006 * 1007 * It is assumed that program headers with PT_NOTE type pointed to by 1008 * @ehdr_ptr has already been updated by update_note_header_size_elf32 1009 * and each of PT_NOTE program headers has actual ELF note segment 1010 * size in its p_memsz member. 1011 */ 1012 static int __init copy_notes_elf32(const Elf32_Ehdr *ehdr_ptr, char *notes_buf) 1013 { 1014 int i, rc=0; 1015 Elf32_Phdr *phdr_ptr; 1016 1017 phdr_ptr = (Elf32_Phdr*)(ehdr_ptr + 1); 1018 1019 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { 1020 u64 offset; 1021 if (phdr_ptr->p_type != PT_NOTE) 1022 continue; 1023 offset = phdr_ptr->p_offset; 1024 rc = elfcorehdr_read_notes(notes_buf, phdr_ptr->p_memsz, 1025 &offset); 1026 if (rc < 0) 1027 return rc; 1028 notes_buf += phdr_ptr->p_memsz; 1029 } 1030 1031 return 0; 1032 } 1033 1034 /* Merges all the PT_NOTE headers into one. */ 1035 static int __init merge_note_headers_elf32(char *elfptr, size_t *elfsz, 1036 char **notes_buf, size_t *notes_sz) 1037 { 1038 int i, nr_ptnote=0, rc=0; 1039 char *tmp; 1040 Elf32_Ehdr *ehdr_ptr; 1041 Elf32_Phdr phdr; 1042 u64 phdr_sz = 0, note_off; 1043 1044 ehdr_ptr = (Elf32_Ehdr *)elfptr; 1045 1046 rc = update_note_header_size_elf32(ehdr_ptr); 1047 if (rc < 0) 1048 return rc; 1049 1050 rc = get_note_number_and_size_elf32(ehdr_ptr, &nr_ptnote, &phdr_sz); 1051 if (rc < 0) 1052 return rc; 1053 1054 *notes_sz = roundup(phdr_sz, PAGE_SIZE); 1055 *notes_buf = vmcore_alloc_buf(*notes_sz); 1056 if (!*notes_buf) 1057 return -ENOMEM; 1058 1059 rc = copy_notes_elf32(ehdr_ptr, *notes_buf); 1060 if (rc < 0) 1061 return rc; 1062 1063 /* Prepare merged PT_NOTE program header. */ 1064 phdr.p_type = PT_NOTE; 1065 phdr.p_flags = 0; 1066 note_off = sizeof(Elf32_Ehdr) + 1067 (ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf32_Phdr); 1068 phdr.p_offset = roundup(note_off, PAGE_SIZE); 1069 phdr.p_vaddr = phdr.p_paddr = 0; 1070 phdr.p_filesz = phdr.p_memsz = phdr_sz; 1071 phdr.p_align = 4; 1072 1073 /* Add merged PT_NOTE program header*/ 1074 tmp = elfptr + sizeof(Elf32_Ehdr); 1075 memcpy(tmp, &phdr, sizeof(phdr)); 1076 tmp += sizeof(phdr); 1077 1078 /* Remove unwanted PT_NOTE program headers. */ 1079 i = (nr_ptnote - 1) * sizeof(Elf32_Phdr); 1080 *elfsz = *elfsz - i; 1081 memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf32_Ehdr)-sizeof(Elf32_Phdr))); 1082 memset(elfptr + *elfsz, 0, i); 1083 *elfsz = roundup(*elfsz, PAGE_SIZE); 1084 1085 /* Modify e_phnum to reflect merged headers. */ 1086 ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1; 1087 1088 /* Store the size of all notes. We need this to update the note 1089 * header when the device dumps will be added. 1090 */ 1091 elfnotes_orig_sz = phdr.p_memsz; 1092 1093 return 0; 1094 } 1095 1096 /* Add memory chunks represented by program headers to vmcore list. Also update 1097 * the new offset fields of exported program headers. */ 1098 static int __init process_ptload_program_headers_elf64(char *elfptr, 1099 size_t elfsz, 1100 size_t elfnotes_sz, 1101 struct list_head *vc_list) 1102 { 1103 int i; 1104 Elf64_Ehdr *ehdr_ptr; 1105 Elf64_Phdr *phdr_ptr; 1106 loff_t vmcore_off; 1107 struct vmcore *new; 1108 1109 ehdr_ptr = (Elf64_Ehdr *)elfptr; 1110 phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr)); /* PT_NOTE hdr */ 1111 1112 /* Skip ELF header, program headers and ELF note segment. */ 1113 vmcore_off = elfsz + elfnotes_sz; 1114 1115 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { 1116 u64 paddr, start, end, size; 1117 1118 if (phdr_ptr->p_type != PT_LOAD) 1119 continue; 1120 1121 paddr = phdr_ptr->p_offset; 1122 start = rounddown(paddr, PAGE_SIZE); 1123 end = roundup(paddr + phdr_ptr->p_memsz, PAGE_SIZE); 1124 size = end - start; 1125 1126 /* Add this contiguous chunk of memory to vmcore list.*/ 1127 new = get_new_element(); 1128 if (!new) 1129 return -ENOMEM; 1130 new->paddr = start; 1131 new->size = size; 1132 list_add_tail(&new->list, vc_list); 1133 1134 /* Update the program header offset. */ 1135 phdr_ptr->p_offset = vmcore_off + (paddr - start); 1136 vmcore_off = vmcore_off + size; 1137 } 1138 return 0; 1139 } 1140 1141 static int __init process_ptload_program_headers_elf32(char *elfptr, 1142 size_t elfsz, 1143 size_t elfnotes_sz, 1144 struct list_head *vc_list) 1145 { 1146 int i; 1147 Elf32_Ehdr *ehdr_ptr; 1148 Elf32_Phdr *phdr_ptr; 1149 loff_t vmcore_off; 1150 struct vmcore *new; 1151 1152 ehdr_ptr = (Elf32_Ehdr *)elfptr; 1153 phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr)); /* PT_NOTE hdr */ 1154 1155 /* Skip ELF header, program headers and ELF note segment. */ 1156 vmcore_off = elfsz + elfnotes_sz; 1157 1158 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { 1159 u64 paddr, start, end, size; 1160 1161 if (phdr_ptr->p_type != PT_LOAD) 1162 continue; 1163 1164 paddr = phdr_ptr->p_offset; 1165 start = rounddown(paddr, PAGE_SIZE); 1166 end = roundup(paddr + phdr_ptr->p_memsz, PAGE_SIZE); 1167 size = end - start; 1168 1169 /* Add this contiguous chunk of memory to vmcore list.*/ 1170 new = get_new_element(); 1171 if (!new) 1172 return -ENOMEM; 1173 new->paddr = start; 1174 new->size = size; 1175 list_add_tail(&new->list, vc_list); 1176 1177 /* Update the program header offset */ 1178 phdr_ptr->p_offset = vmcore_off + (paddr - start); 1179 vmcore_off = vmcore_off + size; 1180 } 1181 return 0; 1182 } 1183 1184 /* Sets offset fields of vmcore elements. */ 1185 static void set_vmcore_list_offsets(size_t elfsz, size_t elfnotes_sz, 1186 struct list_head *vc_list) 1187 { 1188 loff_t vmcore_off; 1189 struct vmcore *m; 1190 1191 /* Skip ELF header, program headers and ELF note segment. */ 1192 vmcore_off = elfsz + elfnotes_sz; 1193 1194 list_for_each_entry(m, vc_list, list) { 1195 m->offset = vmcore_off; 1196 vmcore_off += m->size; 1197 } 1198 } 1199 1200 static void free_elfcorebuf(void) 1201 { 1202 free_pages((unsigned long)elfcorebuf, get_order(elfcorebuf_sz_orig)); 1203 elfcorebuf = NULL; 1204 vfree(elfnotes_buf); 1205 elfnotes_buf = NULL; 1206 } 1207 1208 static int __init parse_crash_elf64_headers(void) 1209 { 1210 int rc=0; 1211 Elf64_Ehdr ehdr; 1212 u64 addr; 1213 1214 addr = elfcorehdr_addr; 1215 1216 /* Read ELF header */ 1217 rc = elfcorehdr_read((char *)&ehdr, sizeof(Elf64_Ehdr), &addr); 1218 if (rc < 0) 1219 return rc; 1220 1221 /* Do some basic Verification. */ 1222 if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0 || 1223 (ehdr.e_type != ET_CORE) || 1224 !vmcore_elf64_check_arch(&ehdr) || 1225 ehdr.e_ident[EI_CLASS] != ELFCLASS64 || 1226 ehdr.e_ident[EI_VERSION] != EV_CURRENT || 1227 ehdr.e_version != EV_CURRENT || 1228 ehdr.e_ehsize != sizeof(Elf64_Ehdr) || 1229 ehdr.e_phentsize != sizeof(Elf64_Phdr) || 1230 ehdr.e_phnum == 0) { 1231 pr_warn("Warning: Core image elf header is not sane\n"); 1232 return -EINVAL; 1233 } 1234 1235 /* Read in all elf headers. */ 1236 elfcorebuf_sz_orig = sizeof(Elf64_Ehdr) + 1237 ehdr.e_phnum * sizeof(Elf64_Phdr); 1238 elfcorebuf_sz = elfcorebuf_sz_orig; 1239 elfcorebuf = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 1240 get_order(elfcorebuf_sz_orig)); 1241 if (!elfcorebuf) 1242 return -ENOMEM; 1243 addr = elfcorehdr_addr; 1244 rc = elfcorehdr_read(elfcorebuf, elfcorebuf_sz_orig, &addr); 1245 if (rc < 0) 1246 goto fail; 1247 1248 /* Merge all PT_NOTE headers into one. */ 1249 rc = merge_note_headers_elf64(elfcorebuf, &elfcorebuf_sz, 1250 &elfnotes_buf, &elfnotes_sz); 1251 if (rc) 1252 goto fail; 1253 rc = process_ptload_program_headers_elf64(elfcorebuf, elfcorebuf_sz, 1254 elfnotes_sz, &vmcore_list); 1255 if (rc) 1256 goto fail; 1257 set_vmcore_list_offsets(elfcorebuf_sz, elfnotes_sz, &vmcore_list); 1258 return 0; 1259 fail: 1260 free_elfcorebuf(); 1261 return rc; 1262 } 1263 1264 static int __init parse_crash_elf32_headers(void) 1265 { 1266 int rc=0; 1267 Elf32_Ehdr ehdr; 1268 u64 addr; 1269 1270 addr = elfcorehdr_addr; 1271 1272 /* Read ELF header */ 1273 rc = elfcorehdr_read((char *)&ehdr, sizeof(Elf32_Ehdr), &addr); 1274 if (rc < 0) 1275 return rc; 1276 1277 /* Do some basic Verification. */ 1278 if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0 || 1279 (ehdr.e_type != ET_CORE) || 1280 !vmcore_elf32_check_arch(&ehdr) || 1281 ehdr.e_ident[EI_CLASS] != ELFCLASS32|| 1282 ehdr.e_ident[EI_VERSION] != EV_CURRENT || 1283 ehdr.e_version != EV_CURRENT || 1284 ehdr.e_ehsize != sizeof(Elf32_Ehdr) || 1285 ehdr.e_phentsize != sizeof(Elf32_Phdr) || 1286 ehdr.e_phnum == 0) { 1287 pr_warn("Warning: Core image elf header is not sane\n"); 1288 return -EINVAL; 1289 } 1290 1291 /* Read in all elf headers. */ 1292 elfcorebuf_sz_orig = sizeof(Elf32_Ehdr) + ehdr.e_phnum * sizeof(Elf32_Phdr); 1293 elfcorebuf_sz = elfcorebuf_sz_orig; 1294 elfcorebuf = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 1295 get_order(elfcorebuf_sz_orig)); 1296 if (!elfcorebuf) 1297 return -ENOMEM; 1298 addr = elfcorehdr_addr; 1299 rc = elfcorehdr_read(elfcorebuf, elfcorebuf_sz_orig, &addr); 1300 if (rc < 0) 1301 goto fail; 1302 1303 /* Merge all PT_NOTE headers into one. */ 1304 rc = merge_note_headers_elf32(elfcorebuf, &elfcorebuf_sz, 1305 &elfnotes_buf, &elfnotes_sz); 1306 if (rc) 1307 goto fail; 1308 rc = process_ptload_program_headers_elf32(elfcorebuf, elfcorebuf_sz, 1309 elfnotes_sz, &vmcore_list); 1310 if (rc) 1311 goto fail; 1312 set_vmcore_list_offsets(elfcorebuf_sz, elfnotes_sz, &vmcore_list); 1313 return 0; 1314 fail: 1315 free_elfcorebuf(); 1316 return rc; 1317 } 1318 1319 static int __init parse_crash_elf_headers(void) 1320 { 1321 unsigned char e_ident[EI_NIDENT]; 1322 u64 addr; 1323 int rc=0; 1324 1325 addr = elfcorehdr_addr; 1326 rc = elfcorehdr_read(e_ident, EI_NIDENT, &addr); 1327 if (rc < 0) 1328 return rc; 1329 if (memcmp(e_ident, ELFMAG, SELFMAG) != 0) { 1330 pr_warn("Warning: Core image elf header not found\n"); 1331 return -EINVAL; 1332 } 1333 1334 if (e_ident[EI_CLASS] == ELFCLASS64) { 1335 rc = parse_crash_elf64_headers(); 1336 if (rc) 1337 return rc; 1338 } else if (e_ident[EI_CLASS] == ELFCLASS32) { 1339 rc = parse_crash_elf32_headers(); 1340 if (rc) 1341 return rc; 1342 } else { 1343 pr_warn("Warning: Core image elf header is not sane\n"); 1344 return -EINVAL; 1345 } 1346 1347 /* Determine vmcore size. */ 1348 vmcore_size = get_vmcore_size(elfcorebuf_sz, elfnotes_sz, 1349 &vmcore_list); 1350 1351 return 0; 1352 } 1353 1354 #ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP 1355 /** 1356 * vmcoredd_write_header - Write vmcore device dump header at the 1357 * beginning of the dump's buffer. 1358 * @buf: Output buffer where the note is written 1359 * @data: Dump info 1360 * @size: Size of the dump 1361 * 1362 * Fills beginning of the dump's buffer with vmcore device dump header. 1363 */ 1364 static void vmcoredd_write_header(void *buf, struct vmcoredd_data *data, 1365 u32 size) 1366 { 1367 struct vmcoredd_header *vdd_hdr = (struct vmcoredd_header *)buf; 1368 1369 vdd_hdr->n_namesz = sizeof(vdd_hdr->name); 1370 vdd_hdr->n_descsz = size + sizeof(vdd_hdr->dump_name); 1371 vdd_hdr->n_type = NT_VMCOREDD; 1372 1373 strncpy((char *)vdd_hdr->name, VMCOREDD_NOTE_NAME, 1374 sizeof(vdd_hdr->name)); 1375 memcpy(vdd_hdr->dump_name, data->dump_name, sizeof(vdd_hdr->dump_name)); 1376 } 1377 1378 /** 1379 * vmcoredd_update_program_headers - Update all ELF program headers 1380 * @elfptr: Pointer to elf header 1381 * @elfnotesz: Size of elf notes aligned to page size 1382 * @vmcoreddsz: Size of device dumps to be added to elf note header 1383 * 1384 * Determine type of ELF header (Elf64 or Elf32) and update the elf note size. 1385 * Also update the offsets of all the program headers after the elf note header. 1386 */ 1387 static void vmcoredd_update_program_headers(char *elfptr, size_t elfnotesz, 1388 size_t vmcoreddsz) 1389 { 1390 unsigned char *e_ident = (unsigned char *)elfptr; 1391 u64 start, end, size; 1392 loff_t vmcore_off; 1393 u32 i; 1394 1395 vmcore_off = elfcorebuf_sz + elfnotesz; 1396 1397 if (e_ident[EI_CLASS] == ELFCLASS64) { 1398 Elf64_Ehdr *ehdr = (Elf64_Ehdr *)elfptr; 1399 Elf64_Phdr *phdr = (Elf64_Phdr *)(elfptr + sizeof(Elf64_Ehdr)); 1400 1401 /* Update all program headers */ 1402 for (i = 0; i < ehdr->e_phnum; i++, phdr++) { 1403 if (phdr->p_type == PT_NOTE) { 1404 /* Update note size */ 1405 phdr->p_memsz = elfnotes_orig_sz + vmcoreddsz; 1406 phdr->p_filesz = phdr->p_memsz; 1407 continue; 1408 } 1409 1410 start = rounddown(phdr->p_offset, PAGE_SIZE); 1411 end = roundup(phdr->p_offset + phdr->p_memsz, 1412 PAGE_SIZE); 1413 size = end - start; 1414 phdr->p_offset = vmcore_off + (phdr->p_offset - start); 1415 vmcore_off += size; 1416 } 1417 } else { 1418 Elf32_Ehdr *ehdr = (Elf32_Ehdr *)elfptr; 1419 Elf32_Phdr *phdr = (Elf32_Phdr *)(elfptr + sizeof(Elf32_Ehdr)); 1420 1421 /* Update all program headers */ 1422 for (i = 0; i < ehdr->e_phnum; i++, phdr++) { 1423 if (phdr->p_type == PT_NOTE) { 1424 /* Update note size */ 1425 phdr->p_memsz = elfnotes_orig_sz + vmcoreddsz; 1426 phdr->p_filesz = phdr->p_memsz; 1427 continue; 1428 } 1429 1430 start = rounddown(phdr->p_offset, PAGE_SIZE); 1431 end = roundup(phdr->p_offset + phdr->p_memsz, 1432 PAGE_SIZE); 1433 size = end - start; 1434 phdr->p_offset = vmcore_off + (phdr->p_offset - start); 1435 vmcore_off += size; 1436 } 1437 } 1438 } 1439 1440 /** 1441 * vmcoredd_update_size - Update the total size of the device dumps and update 1442 * ELF header 1443 * @dump_size: Size of the current device dump to be added to total size 1444 * 1445 * Update the total size of all the device dumps and update the ELF program 1446 * headers. Calculate the new offsets for the vmcore list and update the 1447 * total vmcore size. 1448 */ 1449 static void vmcoredd_update_size(size_t dump_size) 1450 { 1451 vmcoredd_orig_sz += dump_size; 1452 elfnotes_sz = roundup(elfnotes_orig_sz, PAGE_SIZE) + vmcoredd_orig_sz; 1453 vmcoredd_update_program_headers(elfcorebuf, elfnotes_sz, 1454 vmcoredd_orig_sz); 1455 1456 /* Update vmcore list offsets */ 1457 set_vmcore_list_offsets(elfcorebuf_sz, elfnotes_sz, &vmcore_list); 1458 1459 vmcore_size = get_vmcore_size(elfcorebuf_sz, elfnotes_sz, 1460 &vmcore_list); 1461 proc_vmcore->size = vmcore_size; 1462 } 1463 1464 /** 1465 * vmcore_add_device_dump - Add a buffer containing device dump to vmcore 1466 * @data: dump info. 1467 * 1468 * Allocate a buffer and invoke the calling driver's dump collect routine. 1469 * Write ELF note at the beginning of the buffer to indicate vmcore device 1470 * dump and add the dump to global list. 1471 */ 1472 int vmcore_add_device_dump(struct vmcoredd_data *data) 1473 { 1474 struct vmcoredd_node *dump; 1475 void *buf = NULL; 1476 size_t data_size; 1477 int ret; 1478 1479 if (vmcoredd_disabled) { 1480 pr_err_once("Device dump is disabled\n"); 1481 return -EINVAL; 1482 } 1483 1484 if (!data || !strlen(data->dump_name) || 1485 !data->vmcoredd_callback || !data->size) 1486 return -EINVAL; 1487 1488 dump = vzalloc(sizeof(*dump)); 1489 if (!dump) { 1490 ret = -ENOMEM; 1491 goto out_err; 1492 } 1493 1494 /* Keep size of the buffer page aligned so that it can be mmaped */ 1495 data_size = roundup(sizeof(struct vmcoredd_header) + data->size, 1496 PAGE_SIZE); 1497 1498 /* Allocate buffer for driver's to write their dumps */ 1499 buf = vmcore_alloc_buf(data_size); 1500 if (!buf) { 1501 ret = -ENOMEM; 1502 goto out_err; 1503 } 1504 1505 vmcoredd_write_header(buf, data, data_size - 1506 sizeof(struct vmcoredd_header)); 1507 1508 /* Invoke the driver's dump collection routing */ 1509 ret = data->vmcoredd_callback(data, buf + 1510 sizeof(struct vmcoredd_header)); 1511 if (ret) 1512 goto out_err; 1513 1514 dump->buf = buf; 1515 dump->size = data_size; 1516 1517 /* Add the dump to driver sysfs list */ 1518 mutex_lock(&vmcoredd_mutex); 1519 list_add_tail(&dump->list, &vmcoredd_list); 1520 mutex_unlock(&vmcoredd_mutex); 1521 1522 vmcoredd_update_size(data_size); 1523 return 0; 1524 1525 out_err: 1526 vfree(buf); 1527 vfree(dump); 1528 1529 return ret; 1530 } 1531 EXPORT_SYMBOL(vmcore_add_device_dump); 1532 #endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */ 1533 1534 /* Free all dumps in vmcore device dump list */ 1535 static void vmcore_free_device_dumps(void) 1536 { 1537 #ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP 1538 mutex_lock(&vmcoredd_mutex); 1539 while (!list_empty(&vmcoredd_list)) { 1540 struct vmcoredd_node *dump; 1541 1542 dump = list_first_entry(&vmcoredd_list, struct vmcoredd_node, 1543 list); 1544 list_del(&dump->list); 1545 vfree(dump->buf); 1546 vfree(dump); 1547 } 1548 mutex_unlock(&vmcoredd_mutex); 1549 #endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */ 1550 } 1551 1552 /* Init function for vmcore module. */ 1553 static int __init vmcore_init(void) 1554 { 1555 int rc = 0; 1556 1557 /* Allow architectures to allocate ELF header in 2nd kernel */ 1558 rc = elfcorehdr_alloc(&elfcorehdr_addr, &elfcorehdr_size); 1559 if (rc) 1560 return rc; 1561 /* 1562 * If elfcorehdr= has been passed in cmdline or created in 2nd kernel, 1563 * then capture the dump. 1564 */ 1565 if (!(is_vmcore_usable())) 1566 return rc; 1567 rc = parse_crash_elf_headers(); 1568 if (rc) { 1569 elfcorehdr_free(elfcorehdr_addr); 1570 pr_warn("Kdump: vmcore not initialized\n"); 1571 return rc; 1572 } 1573 elfcorehdr_free(elfcorehdr_addr); 1574 elfcorehdr_addr = ELFCORE_ADDR_ERR; 1575 1576 proc_vmcore = proc_create("vmcore", S_IRUSR, NULL, &vmcore_proc_ops); 1577 if (proc_vmcore) 1578 proc_vmcore->size = vmcore_size; 1579 return 0; 1580 } 1581 fs_initcall(vmcore_init); 1582 1583 /* Cleanup function for vmcore module. */ 1584 void vmcore_cleanup(void) 1585 { 1586 if (proc_vmcore) { 1587 proc_remove(proc_vmcore); 1588 proc_vmcore = NULL; 1589 } 1590 1591 /* clear the vmcore list. */ 1592 while (!list_empty(&vmcore_list)) { 1593 struct vmcore *m; 1594 1595 m = list_first_entry(&vmcore_list, struct vmcore, list); 1596 list_del(&m->list); 1597 kfree(m); 1598 } 1599 free_elfcorebuf(); 1600 1601 /* clear vmcore device dump list */ 1602 vmcore_free_device_dumps(); 1603 } 1604