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/uaccess.h> 29 #include <linux/uio.h> 30 #include <linux/cc_platform.h> 31 #include <asm/io.h> 32 #include "internal.h" 33 34 /* List representing chunks of contiguous memory areas and their offsets in 35 * vmcore file. 36 */ 37 static LIST_HEAD(vmcore_list); 38 39 /* Stores the pointer to the buffer containing kernel elf core headers. */ 40 static char *elfcorebuf; 41 static size_t elfcorebuf_sz; 42 static size_t elfcorebuf_sz_orig; 43 44 static char *elfnotes_buf; 45 static size_t elfnotes_sz; 46 /* Size of all notes minus the device dump notes */ 47 static size_t elfnotes_orig_sz; 48 49 /* Total size of vmcore file. */ 50 static u64 vmcore_size; 51 52 static struct proc_dir_entry *proc_vmcore; 53 54 #ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP 55 /* Device Dump list and mutex to synchronize access to list */ 56 static LIST_HEAD(vmcoredd_list); 57 static DEFINE_MUTEX(vmcoredd_mutex); 58 59 static bool vmcoredd_disabled; 60 core_param(novmcoredd, vmcoredd_disabled, bool, 0); 61 #endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */ 62 63 /* Device Dump Size */ 64 static size_t vmcoredd_orig_sz; 65 66 static DEFINE_SPINLOCK(vmcore_cb_lock); 67 DEFINE_STATIC_SRCU(vmcore_cb_srcu); 68 /* List of registered vmcore callbacks. */ 69 static LIST_HEAD(vmcore_cb_list); 70 /* Whether the vmcore has been opened once. */ 71 static bool vmcore_opened; 72 73 void register_vmcore_cb(struct vmcore_cb *cb) 74 { 75 INIT_LIST_HEAD(&cb->next); 76 spin_lock(&vmcore_cb_lock); 77 list_add_tail(&cb->next, &vmcore_cb_list); 78 /* 79 * Registering a vmcore callback after the vmcore was opened is 80 * very unusual (e.g., manual driver loading). 81 */ 82 if (vmcore_opened) 83 pr_warn_once("Unexpected vmcore callback registration\n"); 84 spin_unlock(&vmcore_cb_lock); 85 } 86 EXPORT_SYMBOL_GPL(register_vmcore_cb); 87 88 void unregister_vmcore_cb(struct vmcore_cb *cb) 89 { 90 spin_lock(&vmcore_cb_lock); 91 list_del_rcu(&cb->next); 92 /* 93 * Unregistering a vmcore callback after the vmcore was opened is 94 * very unusual (e.g., forced driver removal), but we cannot stop 95 * unregistering. 96 */ 97 if (vmcore_opened) 98 pr_warn_once("Unexpected vmcore callback unregistration\n"); 99 spin_unlock(&vmcore_cb_lock); 100 101 synchronize_srcu(&vmcore_cb_srcu); 102 } 103 EXPORT_SYMBOL_GPL(unregister_vmcore_cb); 104 105 static bool pfn_is_ram(unsigned long pfn) 106 { 107 struct vmcore_cb *cb; 108 bool ret = true; 109 110 list_for_each_entry_srcu(cb, &vmcore_cb_list, next, 111 srcu_read_lock_held(&vmcore_cb_srcu)) { 112 if (unlikely(!cb->pfn_is_ram)) 113 continue; 114 ret = cb->pfn_is_ram(cb, pfn); 115 if (!ret) 116 break; 117 } 118 119 return ret; 120 } 121 122 static int open_vmcore(struct inode *inode, struct file *file) 123 { 124 spin_lock(&vmcore_cb_lock); 125 vmcore_opened = true; 126 spin_unlock(&vmcore_cb_lock); 127 128 return 0; 129 } 130 131 /* Reads a page from the oldmem device from given offset. */ 132 ssize_t read_from_oldmem(struct iov_iter *iter, size_t count, 133 u64 *ppos, bool encrypted) 134 { 135 unsigned long pfn, offset; 136 size_t nr_bytes; 137 ssize_t read = 0, tmp; 138 int idx; 139 140 if (!count) 141 return 0; 142 143 offset = (unsigned long)(*ppos % PAGE_SIZE); 144 pfn = (unsigned long)(*ppos / PAGE_SIZE); 145 146 idx = srcu_read_lock(&vmcore_cb_srcu); 147 do { 148 if (count > (PAGE_SIZE - offset)) 149 nr_bytes = PAGE_SIZE - offset; 150 else 151 nr_bytes = count; 152 153 /* If pfn is not ram, return zeros for sparse dump files */ 154 if (!pfn_is_ram(pfn)) { 155 tmp = iov_iter_zero(nr_bytes, iter); 156 } else { 157 if (encrypted) 158 tmp = copy_oldmem_page_encrypted(iter, pfn, 159 nr_bytes, 160 offset); 161 else 162 tmp = copy_oldmem_page(iter, pfn, nr_bytes, 163 offset); 164 } 165 if (tmp < nr_bytes) { 166 srcu_read_unlock(&vmcore_cb_srcu, idx); 167 return -EFAULT; 168 } 169 170 *ppos += nr_bytes; 171 count -= nr_bytes; 172 read += nr_bytes; 173 ++pfn; 174 offset = 0; 175 } while (count); 176 srcu_read_unlock(&vmcore_cb_srcu, idx); 177 178 return read; 179 } 180 181 /* 182 * Architectures may override this function to allocate ELF header in 2nd kernel 183 */ 184 int __weak elfcorehdr_alloc(unsigned long long *addr, unsigned long long *size) 185 { 186 return 0; 187 } 188 189 /* 190 * Architectures may override this function to free header 191 */ 192 void __weak elfcorehdr_free(unsigned long long addr) 193 {} 194 195 /* 196 * Architectures may override this function to read from ELF header 197 */ 198 ssize_t __weak elfcorehdr_read(char *buf, size_t count, u64 *ppos) 199 { 200 struct kvec kvec = { .iov_base = buf, .iov_len = count }; 201 struct iov_iter iter; 202 203 iov_iter_kvec(&iter, READ, &kvec, 1, count); 204 205 return read_from_oldmem(&iter, count, ppos, false); 206 } 207 208 /* 209 * Architectures may override this function to read from notes sections 210 */ 211 ssize_t __weak elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos) 212 { 213 struct kvec kvec = { .iov_base = buf, .iov_len = count }; 214 struct iov_iter iter; 215 216 iov_iter_kvec(&iter, READ, &kvec, 1, count); 217 218 return read_from_oldmem(&iter, count, ppos, 219 cc_platform_has(CC_ATTR_MEM_ENCRYPT)); 220 } 221 222 /* 223 * Architectures may override this function to map oldmem 224 */ 225 int __weak remap_oldmem_pfn_range(struct vm_area_struct *vma, 226 unsigned long from, unsigned long pfn, 227 unsigned long size, pgprot_t prot) 228 { 229 prot = pgprot_encrypted(prot); 230 return remap_pfn_range(vma, from, pfn, size, prot); 231 } 232 233 /* 234 * Architectures which support memory encryption override this. 235 */ 236 ssize_t __weak copy_oldmem_page_encrypted(struct iov_iter *iter, 237 unsigned long pfn, size_t csize, unsigned long offset) 238 { 239 return copy_oldmem_page(iter, pfn, csize, offset); 240 } 241 242 #ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP 243 static int vmcoredd_copy_dumps(struct iov_iter *iter, u64 start, size_t size) 244 { 245 struct vmcoredd_node *dump; 246 u64 offset = 0; 247 int ret = 0; 248 size_t tsz; 249 char *buf; 250 251 mutex_lock(&vmcoredd_mutex); 252 list_for_each_entry(dump, &vmcoredd_list, list) { 253 if (start < offset + dump->size) { 254 tsz = min(offset + (u64)dump->size - start, (u64)size); 255 buf = dump->buf + start - offset; 256 if (copy_to_iter(buf, tsz, iter) < tsz) { 257 ret = -EFAULT; 258 goto out_unlock; 259 } 260 261 size -= tsz; 262 start += tsz; 263 264 /* Leave now if buffer filled already */ 265 if (!size) 266 goto out_unlock; 267 } 268 offset += dump->size; 269 } 270 271 out_unlock: 272 mutex_unlock(&vmcoredd_mutex); 273 return ret; 274 } 275 276 #ifdef CONFIG_MMU 277 static int vmcoredd_mmap_dumps(struct vm_area_struct *vma, unsigned long dst, 278 u64 start, size_t size) 279 { 280 struct vmcoredd_node *dump; 281 u64 offset = 0; 282 int ret = 0; 283 size_t tsz; 284 char *buf; 285 286 mutex_lock(&vmcoredd_mutex); 287 list_for_each_entry(dump, &vmcoredd_list, list) { 288 if (start < offset + dump->size) { 289 tsz = min(offset + (u64)dump->size - start, (u64)size); 290 buf = dump->buf + start - offset; 291 if (remap_vmalloc_range_partial(vma, dst, buf, 0, 292 tsz)) { 293 ret = -EFAULT; 294 goto out_unlock; 295 } 296 297 size -= tsz; 298 start += tsz; 299 dst += tsz; 300 301 /* Leave now if buffer filled already */ 302 if (!size) 303 goto out_unlock; 304 } 305 offset += dump->size; 306 } 307 308 out_unlock: 309 mutex_unlock(&vmcoredd_mutex); 310 return ret; 311 } 312 #endif /* CONFIG_MMU */ 313 #endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */ 314 315 /* Read from the ELF header and then the crash dump. On error, negative value is 316 * returned otherwise number of bytes read are returned. 317 */ 318 static ssize_t __read_vmcore(struct iov_iter *iter, loff_t *fpos) 319 { 320 ssize_t acc = 0, tmp; 321 size_t tsz; 322 u64 start; 323 struct vmcore *m = NULL; 324 325 if (!iov_iter_count(iter) || *fpos >= vmcore_size) 326 return 0; 327 328 iov_iter_truncate(iter, vmcore_size - *fpos); 329 330 /* Read ELF core header */ 331 if (*fpos < elfcorebuf_sz) { 332 tsz = min(elfcorebuf_sz - (size_t)*fpos, iov_iter_count(iter)); 333 if (copy_to_iter(elfcorebuf + *fpos, tsz, iter) < tsz) 334 return -EFAULT; 335 *fpos += tsz; 336 acc += tsz; 337 338 /* leave now if filled buffer already */ 339 if (!iov_iter_count(iter)) 340 return acc; 341 } 342 343 /* Read Elf note segment */ 344 if (*fpos < elfcorebuf_sz + elfnotes_sz) { 345 void *kaddr; 346 347 /* We add device dumps before other elf notes because the 348 * other elf notes may not fill the elf notes buffer 349 * completely and we will end up with zero-filled data 350 * between the elf notes and the device dumps. Tools will 351 * then try to decode this zero-filled data as valid notes 352 * and we don't want that. Hence, adding device dumps before 353 * the other elf notes ensure that zero-filled data can be 354 * avoided. 355 */ 356 #ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP 357 /* Read device dumps */ 358 if (*fpos < elfcorebuf_sz + vmcoredd_orig_sz) { 359 tsz = min(elfcorebuf_sz + vmcoredd_orig_sz - 360 (size_t)*fpos, iov_iter_count(iter)); 361 start = *fpos - elfcorebuf_sz; 362 if (vmcoredd_copy_dumps(iter, start, tsz)) 363 return -EFAULT; 364 365 *fpos += tsz; 366 acc += tsz; 367 368 /* leave now if filled buffer already */ 369 if (!iov_iter_count(iter)) 370 return acc; 371 } 372 #endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */ 373 374 /* Read remaining elf notes */ 375 tsz = min(elfcorebuf_sz + elfnotes_sz - (size_t)*fpos, 376 iov_iter_count(iter)); 377 kaddr = elfnotes_buf + *fpos - elfcorebuf_sz - vmcoredd_orig_sz; 378 if (copy_to_iter(kaddr, tsz, iter) < tsz) 379 return -EFAULT; 380 381 *fpos += tsz; 382 acc += tsz; 383 384 /* leave now if filled buffer already */ 385 if (!iov_iter_count(iter)) 386 return acc; 387 } 388 389 list_for_each_entry(m, &vmcore_list, list) { 390 if (*fpos < m->offset + m->size) { 391 tsz = (size_t)min_t(unsigned long long, 392 m->offset + m->size - *fpos, 393 iov_iter_count(iter)); 394 start = m->paddr + *fpos - m->offset; 395 tmp = read_from_oldmem(iter, tsz, &start, 396 cc_platform_has(CC_ATTR_MEM_ENCRYPT)); 397 if (tmp < 0) 398 return tmp; 399 *fpos += tsz; 400 acc += tsz; 401 402 /* leave now if filled buffer already */ 403 if (!iov_iter_count(iter)) 404 return acc; 405 } 406 } 407 408 return acc; 409 } 410 411 static ssize_t read_vmcore(struct kiocb *iocb, struct iov_iter *iter) 412 { 413 return __read_vmcore(iter, &iocb->ki_pos); 414 } 415 416 /* 417 * The vmcore fault handler uses the page cache and fills data using the 418 * standard __read_vmcore() function. 419 * 420 * On s390 the fault handler is used for memory regions that can't be mapped 421 * directly with remap_pfn_range(). 422 */ 423 static vm_fault_t mmap_vmcore_fault(struct vm_fault *vmf) 424 { 425 #ifdef CONFIG_S390 426 struct address_space *mapping = vmf->vma->vm_file->f_mapping; 427 pgoff_t index = vmf->pgoff; 428 struct iov_iter iter; 429 struct kvec kvec; 430 struct page *page; 431 loff_t offset; 432 int rc; 433 434 page = find_or_create_page(mapping, index, GFP_KERNEL); 435 if (!page) 436 return VM_FAULT_OOM; 437 if (!PageUptodate(page)) { 438 offset = (loff_t) index << PAGE_SHIFT; 439 kvec.iov_base = page_address(page); 440 kvec.iov_len = PAGE_SIZE; 441 iov_iter_kvec(&iter, READ, &kvec, 1, PAGE_SIZE); 442 443 rc = __read_vmcore(&iter, &offset); 444 if (rc < 0) { 445 unlock_page(page); 446 put_page(page); 447 return vmf_error(rc); 448 } 449 SetPageUptodate(page); 450 } 451 unlock_page(page); 452 vmf->page = page; 453 return 0; 454 #else 455 return VM_FAULT_SIGBUS; 456 #endif 457 } 458 459 static const struct vm_operations_struct vmcore_mmap_ops = { 460 .fault = mmap_vmcore_fault, 461 }; 462 463 /** 464 * vmcore_alloc_buf - allocate buffer in vmalloc memory 465 * @size: size of buffer 466 * 467 * If CONFIG_MMU is defined, use vmalloc_user() to allow users to mmap 468 * the buffer to user-space by means of remap_vmalloc_range(). 469 * 470 * If CONFIG_MMU is not defined, use vzalloc() since mmap_vmcore() is 471 * disabled and there's no need to allow users to mmap the buffer. 472 */ 473 static inline char *vmcore_alloc_buf(size_t size) 474 { 475 #ifdef CONFIG_MMU 476 return vmalloc_user(size); 477 #else 478 return vzalloc(size); 479 #endif 480 } 481 482 /* 483 * Disable mmap_vmcore() if CONFIG_MMU is not defined. MMU is 484 * essential for mmap_vmcore() in order to map physically 485 * non-contiguous objects (ELF header, ELF note segment and memory 486 * regions in the 1st kernel pointed to by PT_LOAD entries) into 487 * virtually contiguous user-space in ELF layout. 488 */ 489 #ifdef CONFIG_MMU 490 /* 491 * remap_oldmem_pfn_checked - do remap_oldmem_pfn_range replacing all pages 492 * reported as not being ram with the zero page. 493 * 494 * @vma: vm_area_struct describing requested mapping 495 * @from: start remapping from 496 * @pfn: page frame number to start remapping to 497 * @size: remapping size 498 * @prot: protection bits 499 * 500 * Returns zero on success, -EAGAIN on failure. 501 */ 502 static int remap_oldmem_pfn_checked(struct vm_area_struct *vma, 503 unsigned long from, unsigned long pfn, 504 unsigned long size, pgprot_t prot) 505 { 506 unsigned long map_size; 507 unsigned long pos_start, pos_end, pos; 508 unsigned long zeropage_pfn = my_zero_pfn(0); 509 size_t len = 0; 510 511 pos_start = pfn; 512 pos_end = pfn + (size >> PAGE_SHIFT); 513 514 for (pos = pos_start; pos < pos_end; ++pos) { 515 if (!pfn_is_ram(pos)) { 516 /* 517 * We hit a page which is not ram. Remap the continuous 518 * region between pos_start and pos-1 and replace 519 * the non-ram page at pos with the zero page. 520 */ 521 if (pos > pos_start) { 522 /* Remap continuous region */ 523 map_size = (pos - pos_start) << PAGE_SHIFT; 524 if (remap_oldmem_pfn_range(vma, from + len, 525 pos_start, map_size, 526 prot)) 527 goto fail; 528 len += map_size; 529 } 530 /* Remap the zero page */ 531 if (remap_oldmem_pfn_range(vma, from + len, 532 zeropage_pfn, 533 PAGE_SIZE, prot)) 534 goto fail; 535 len += PAGE_SIZE; 536 pos_start = pos + 1; 537 } 538 } 539 if (pos > pos_start) { 540 /* Remap the rest */ 541 map_size = (pos - pos_start) << PAGE_SHIFT; 542 if (remap_oldmem_pfn_range(vma, from + len, pos_start, 543 map_size, prot)) 544 goto fail; 545 } 546 return 0; 547 fail: 548 do_munmap(vma->vm_mm, from, len, NULL); 549 return -EAGAIN; 550 } 551 552 static int vmcore_remap_oldmem_pfn(struct vm_area_struct *vma, 553 unsigned long from, unsigned long pfn, 554 unsigned long size, pgprot_t prot) 555 { 556 int ret, idx; 557 558 /* 559 * Check if a callback was registered to avoid looping over all 560 * pages without a reason. 561 */ 562 idx = srcu_read_lock(&vmcore_cb_srcu); 563 if (!list_empty(&vmcore_cb_list)) 564 ret = remap_oldmem_pfn_checked(vma, from, pfn, size, prot); 565 else 566 ret = remap_oldmem_pfn_range(vma, from, pfn, size, prot); 567 srcu_read_unlock(&vmcore_cb_srcu, idx); 568 return ret; 569 } 570 571 static int mmap_vmcore(struct file *file, struct vm_area_struct *vma) 572 { 573 size_t size = vma->vm_end - vma->vm_start; 574 u64 start, end, len, tsz; 575 struct vmcore *m; 576 577 start = (u64)vma->vm_pgoff << PAGE_SHIFT; 578 end = start + size; 579 580 if (size > vmcore_size || end > vmcore_size) 581 return -EINVAL; 582 583 if (vma->vm_flags & (VM_WRITE | VM_EXEC)) 584 return -EPERM; 585 586 vma->vm_flags &= ~(VM_MAYWRITE | VM_MAYEXEC); 587 vma->vm_flags |= VM_MIXEDMAP; 588 vma->vm_ops = &vmcore_mmap_ops; 589 590 len = 0; 591 592 if (start < elfcorebuf_sz) { 593 u64 pfn; 594 595 tsz = min(elfcorebuf_sz - (size_t)start, size); 596 pfn = __pa(elfcorebuf + start) >> PAGE_SHIFT; 597 if (remap_pfn_range(vma, vma->vm_start, pfn, tsz, 598 vma->vm_page_prot)) 599 return -EAGAIN; 600 size -= tsz; 601 start += tsz; 602 len += tsz; 603 604 if (size == 0) 605 return 0; 606 } 607 608 if (start < elfcorebuf_sz + elfnotes_sz) { 609 void *kaddr; 610 611 /* We add device dumps before other elf notes because the 612 * other elf notes may not fill the elf notes buffer 613 * completely and we will end up with zero-filled data 614 * between the elf notes and the device dumps. Tools will 615 * then try to decode this zero-filled data as valid notes 616 * and we don't want that. Hence, adding device dumps before 617 * the other elf notes ensure that zero-filled data can be 618 * avoided. This also ensures that the device dumps and 619 * other elf notes can be properly mmaped at page aligned 620 * address. 621 */ 622 #ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP 623 /* Read device dumps */ 624 if (start < elfcorebuf_sz + vmcoredd_orig_sz) { 625 u64 start_off; 626 627 tsz = min(elfcorebuf_sz + vmcoredd_orig_sz - 628 (size_t)start, size); 629 start_off = start - elfcorebuf_sz; 630 if (vmcoredd_mmap_dumps(vma, vma->vm_start + len, 631 start_off, tsz)) 632 goto fail; 633 634 size -= tsz; 635 start += tsz; 636 len += tsz; 637 638 /* leave now if filled buffer already */ 639 if (!size) 640 return 0; 641 } 642 #endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */ 643 644 /* Read remaining elf notes */ 645 tsz = min(elfcorebuf_sz + elfnotes_sz - (size_t)start, size); 646 kaddr = elfnotes_buf + start - elfcorebuf_sz - vmcoredd_orig_sz; 647 if (remap_vmalloc_range_partial(vma, vma->vm_start + len, 648 kaddr, 0, tsz)) 649 goto fail; 650 651 size -= tsz; 652 start += tsz; 653 len += tsz; 654 655 if (size == 0) 656 return 0; 657 } 658 659 list_for_each_entry(m, &vmcore_list, list) { 660 if (start < m->offset + m->size) { 661 u64 paddr = 0; 662 663 tsz = (size_t)min_t(unsigned long long, 664 m->offset + m->size - start, size); 665 paddr = m->paddr + start - m->offset; 666 if (vmcore_remap_oldmem_pfn(vma, vma->vm_start + len, 667 paddr >> PAGE_SHIFT, tsz, 668 vma->vm_page_prot)) 669 goto fail; 670 size -= tsz; 671 start += tsz; 672 len += tsz; 673 674 if (size == 0) 675 return 0; 676 } 677 } 678 679 return 0; 680 fail: 681 do_munmap(vma->vm_mm, vma->vm_start, len, NULL); 682 return -EAGAIN; 683 } 684 #else 685 static int mmap_vmcore(struct file *file, struct vm_area_struct *vma) 686 { 687 return -ENOSYS; 688 } 689 #endif 690 691 static const struct proc_ops vmcore_proc_ops = { 692 .proc_open = open_vmcore, 693 .proc_read_iter = read_vmcore, 694 .proc_lseek = default_llseek, 695 .proc_mmap = mmap_vmcore, 696 }; 697 698 static struct vmcore* __init get_new_element(void) 699 { 700 return kzalloc(sizeof(struct vmcore), GFP_KERNEL); 701 } 702 703 static u64 get_vmcore_size(size_t elfsz, size_t elfnotesegsz, 704 struct list_head *vc_list) 705 { 706 u64 size; 707 struct vmcore *m; 708 709 size = elfsz + elfnotesegsz; 710 list_for_each_entry(m, vc_list, list) { 711 size += m->size; 712 } 713 return size; 714 } 715 716 /** 717 * update_note_header_size_elf64 - update p_memsz member of each PT_NOTE entry 718 * 719 * @ehdr_ptr: ELF header 720 * 721 * This function updates p_memsz member of each PT_NOTE entry in the 722 * program header table pointed to by @ehdr_ptr to real size of ELF 723 * note segment. 724 */ 725 static int __init update_note_header_size_elf64(const Elf64_Ehdr *ehdr_ptr) 726 { 727 int i, rc=0; 728 Elf64_Phdr *phdr_ptr; 729 Elf64_Nhdr *nhdr_ptr; 730 731 phdr_ptr = (Elf64_Phdr *)(ehdr_ptr + 1); 732 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { 733 void *notes_section; 734 u64 offset, max_sz, sz, real_sz = 0; 735 if (phdr_ptr->p_type != PT_NOTE) 736 continue; 737 max_sz = phdr_ptr->p_memsz; 738 offset = phdr_ptr->p_offset; 739 notes_section = kmalloc(max_sz, GFP_KERNEL); 740 if (!notes_section) 741 return -ENOMEM; 742 rc = elfcorehdr_read_notes(notes_section, max_sz, &offset); 743 if (rc < 0) { 744 kfree(notes_section); 745 return rc; 746 } 747 nhdr_ptr = notes_section; 748 while (nhdr_ptr->n_namesz != 0) { 749 sz = sizeof(Elf64_Nhdr) + 750 (((u64)nhdr_ptr->n_namesz + 3) & ~3) + 751 (((u64)nhdr_ptr->n_descsz + 3) & ~3); 752 if ((real_sz + sz) > max_sz) { 753 pr_warn("Warning: Exceeded p_memsz, dropping PT_NOTE entry n_namesz=0x%x, n_descsz=0x%x\n", 754 nhdr_ptr->n_namesz, nhdr_ptr->n_descsz); 755 break; 756 } 757 real_sz += sz; 758 nhdr_ptr = (Elf64_Nhdr*)((char*)nhdr_ptr + sz); 759 } 760 kfree(notes_section); 761 phdr_ptr->p_memsz = real_sz; 762 if (real_sz == 0) { 763 pr_warn("Warning: Zero PT_NOTE entries found\n"); 764 } 765 } 766 767 return 0; 768 } 769 770 /** 771 * get_note_number_and_size_elf64 - get the number of PT_NOTE program 772 * headers and sum of real size of their ELF note segment headers and 773 * data. 774 * 775 * @ehdr_ptr: ELF header 776 * @nr_ptnote: buffer for the number of PT_NOTE program headers 777 * @sz_ptnote: buffer for size of unique PT_NOTE program header 778 * 779 * This function is used to merge multiple PT_NOTE program headers 780 * into a unique single one. The resulting unique entry will have 781 * @sz_ptnote in its phdr->p_mem. 782 * 783 * It is assumed that program headers with PT_NOTE type pointed to by 784 * @ehdr_ptr has already been updated by update_note_header_size_elf64 785 * and each of PT_NOTE program headers has actual ELF note segment 786 * size in its p_memsz member. 787 */ 788 static int __init get_note_number_and_size_elf64(const Elf64_Ehdr *ehdr_ptr, 789 int *nr_ptnote, u64 *sz_ptnote) 790 { 791 int i; 792 Elf64_Phdr *phdr_ptr; 793 794 *nr_ptnote = *sz_ptnote = 0; 795 796 phdr_ptr = (Elf64_Phdr *)(ehdr_ptr + 1); 797 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { 798 if (phdr_ptr->p_type != PT_NOTE) 799 continue; 800 *nr_ptnote += 1; 801 *sz_ptnote += phdr_ptr->p_memsz; 802 } 803 804 return 0; 805 } 806 807 /** 808 * copy_notes_elf64 - copy ELF note segments in a given buffer 809 * 810 * @ehdr_ptr: ELF header 811 * @notes_buf: buffer into which ELF note segments are copied 812 * 813 * This function is used to copy ELF note segment in the 1st kernel 814 * into the buffer @notes_buf in the 2nd kernel. It is assumed that 815 * size of the buffer @notes_buf is equal to or larger than sum of the 816 * real ELF note segment headers and data. 817 * 818 * It is assumed that program headers with PT_NOTE type pointed to by 819 * @ehdr_ptr has already been updated by update_note_header_size_elf64 820 * and each of PT_NOTE program headers has actual ELF note segment 821 * size in its p_memsz member. 822 */ 823 static int __init copy_notes_elf64(const Elf64_Ehdr *ehdr_ptr, char *notes_buf) 824 { 825 int i, rc=0; 826 Elf64_Phdr *phdr_ptr; 827 828 phdr_ptr = (Elf64_Phdr*)(ehdr_ptr + 1); 829 830 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { 831 u64 offset; 832 if (phdr_ptr->p_type != PT_NOTE) 833 continue; 834 offset = phdr_ptr->p_offset; 835 rc = elfcorehdr_read_notes(notes_buf, phdr_ptr->p_memsz, 836 &offset); 837 if (rc < 0) 838 return rc; 839 notes_buf += phdr_ptr->p_memsz; 840 } 841 842 return 0; 843 } 844 845 /* Merges all the PT_NOTE headers into one. */ 846 static int __init merge_note_headers_elf64(char *elfptr, size_t *elfsz, 847 char **notes_buf, size_t *notes_sz) 848 { 849 int i, nr_ptnote=0, rc=0; 850 char *tmp; 851 Elf64_Ehdr *ehdr_ptr; 852 Elf64_Phdr phdr; 853 u64 phdr_sz = 0, note_off; 854 855 ehdr_ptr = (Elf64_Ehdr *)elfptr; 856 857 rc = update_note_header_size_elf64(ehdr_ptr); 858 if (rc < 0) 859 return rc; 860 861 rc = get_note_number_and_size_elf64(ehdr_ptr, &nr_ptnote, &phdr_sz); 862 if (rc < 0) 863 return rc; 864 865 *notes_sz = roundup(phdr_sz, PAGE_SIZE); 866 *notes_buf = vmcore_alloc_buf(*notes_sz); 867 if (!*notes_buf) 868 return -ENOMEM; 869 870 rc = copy_notes_elf64(ehdr_ptr, *notes_buf); 871 if (rc < 0) 872 return rc; 873 874 /* Prepare merged PT_NOTE program header. */ 875 phdr.p_type = PT_NOTE; 876 phdr.p_flags = 0; 877 note_off = sizeof(Elf64_Ehdr) + 878 (ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf64_Phdr); 879 phdr.p_offset = roundup(note_off, PAGE_SIZE); 880 phdr.p_vaddr = phdr.p_paddr = 0; 881 phdr.p_filesz = phdr.p_memsz = phdr_sz; 882 phdr.p_align = 0; 883 884 /* Add merged PT_NOTE program header*/ 885 tmp = elfptr + sizeof(Elf64_Ehdr); 886 memcpy(tmp, &phdr, sizeof(phdr)); 887 tmp += sizeof(phdr); 888 889 /* Remove unwanted PT_NOTE program headers. */ 890 i = (nr_ptnote - 1) * sizeof(Elf64_Phdr); 891 *elfsz = *elfsz - i; 892 memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf64_Ehdr)-sizeof(Elf64_Phdr))); 893 memset(elfptr + *elfsz, 0, i); 894 *elfsz = roundup(*elfsz, PAGE_SIZE); 895 896 /* Modify e_phnum to reflect merged headers. */ 897 ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1; 898 899 /* Store the size of all notes. We need this to update the note 900 * header when the device dumps will be added. 901 */ 902 elfnotes_orig_sz = phdr.p_memsz; 903 904 return 0; 905 } 906 907 /** 908 * update_note_header_size_elf32 - update p_memsz member of each PT_NOTE entry 909 * 910 * @ehdr_ptr: ELF header 911 * 912 * This function updates p_memsz member of each PT_NOTE entry in the 913 * program header table pointed to by @ehdr_ptr to real size of ELF 914 * note segment. 915 */ 916 static int __init update_note_header_size_elf32(const Elf32_Ehdr *ehdr_ptr) 917 { 918 int i, rc=0; 919 Elf32_Phdr *phdr_ptr; 920 Elf32_Nhdr *nhdr_ptr; 921 922 phdr_ptr = (Elf32_Phdr *)(ehdr_ptr + 1); 923 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { 924 void *notes_section; 925 u64 offset, max_sz, sz, real_sz = 0; 926 if (phdr_ptr->p_type != PT_NOTE) 927 continue; 928 max_sz = phdr_ptr->p_memsz; 929 offset = phdr_ptr->p_offset; 930 notes_section = kmalloc(max_sz, GFP_KERNEL); 931 if (!notes_section) 932 return -ENOMEM; 933 rc = elfcorehdr_read_notes(notes_section, max_sz, &offset); 934 if (rc < 0) { 935 kfree(notes_section); 936 return rc; 937 } 938 nhdr_ptr = notes_section; 939 while (nhdr_ptr->n_namesz != 0) { 940 sz = sizeof(Elf32_Nhdr) + 941 (((u64)nhdr_ptr->n_namesz + 3) & ~3) + 942 (((u64)nhdr_ptr->n_descsz + 3) & ~3); 943 if ((real_sz + sz) > max_sz) { 944 pr_warn("Warning: Exceeded p_memsz, dropping PT_NOTE entry n_namesz=0x%x, n_descsz=0x%x\n", 945 nhdr_ptr->n_namesz, nhdr_ptr->n_descsz); 946 break; 947 } 948 real_sz += sz; 949 nhdr_ptr = (Elf32_Nhdr*)((char*)nhdr_ptr + sz); 950 } 951 kfree(notes_section); 952 phdr_ptr->p_memsz = real_sz; 953 if (real_sz == 0) { 954 pr_warn("Warning: Zero PT_NOTE entries found\n"); 955 } 956 } 957 958 return 0; 959 } 960 961 /** 962 * get_note_number_and_size_elf32 - get the number of PT_NOTE program 963 * headers and sum of real size of their ELF note segment headers and 964 * data. 965 * 966 * @ehdr_ptr: ELF header 967 * @nr_ptnote: buffer for the number of PT_NOTE program headers 968 * @sz_ptnote: buffer for size of unique PT_NOTE program header 969 * 970 * This function is used to merge multiple PT_NOTE program headers 971 * into a unique single one. The resulting unique entry will have 972 * @sz_ptnote in its phdr->p_mem. 973 * 974 * It is assumed that program headers with PT_NOTE type pointed to by 975 * @ehdr_ptr has already been updated by update_note_header_size_elf32 976 * and each of PT_NOTE program headers has actual ELF note segment 977 * size in its p_memsz member. 978 */ 979 static int __init get_note_number_and_size_elf32(const Elf32_Ehdr *ehdr_ptr, 980 int *nr_ptnote, u64 *sz_ptnote) 981 { 982 int i; 983 Elf32_Phdr *phdr_ptr; 984 985 *nr_ptnote = *sz_ptnote = 0; 986 987 phdr_ptr = (Elf32_Phdr *)(ehdr_ptr + 1); 988 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { 989 if (phdr_ptr->p_type != PT_NOTE) 990 continue; 991 *nr_ptnote += 1; 992 *sz_ptnote += phdr_ptr->p_memsz; 993 } 994 995 return 0; 996 } 997 998 /** 999 * copy_notes_elf32 - copy ELF note segments in a given buffer 1000 * 1001 * @ehdr_ptr: ELF header 1002 * @notes_buf: buffer into which ELF note segments are copied 1003 * 1004 * This function is used to copy ELF note segment in the 1st kernel 1005 * into the buffer @notes_buf in the 2nd kernel. It is assumed that 1006 * size of the buffer @notes_buf is equal to or larger than sum of the 1007 * real ELF note segment headers and data. 1008 * 1009 * It is assumed that program headers with PT_NOTE type pointed to by 1010 * @ehdr_ptr has already been updated by update_note_header_size_elf32 1011 * and each of PT_NOTE program headers has actual ELF note segment 1012 * size in its p_memsz member. 1013 */ 1014 static int __init copy_notes_elf32(const Elf32_Ehdr *ehdr_ptr, char *notes_buf) 1015 { 1016 int i, rc=0; 1017 Elf32_Phdr *phdr_ptr; 1018 1019 phdr_ptr = (Elf32_Phdr*)(ehdr_ptr + 1); 1020 1021 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { 1022 u64 offset; 1023 if (phdr_ptr->p_type != PT_NOTE) 1024 continue; 1025 offset = phdr_ptr->p_offset; 1026 rc = elfcorehdr_read_notes(notes_buf, phdr_ptr->p_memsz, 1027 &offset); 1028 if (rc < 0) 1029 return rc; 1030 notes_buf += phdr_ptr->p_memsz; 1031 } 1032 1033 return 0; 1034 } 1035 1036 /* Merges all the PT_NOTE headers into one. */ 1037 static int __init merge_note_headers_elf32(char *elfptr, size_t *elfsz, 1038 char **notes_buf, size_t *notes_sz) 1039 { 1040 int i, nr_ptnote=0, rc=0; 1041 char *tmp; 1042 Elf32_Ehdr *ehdr_ptr; 1043 Elf32_Phdr phdr; 1044 u64 phdr_sz = 0, note_off; 1045 1046 ehdr_ptr = (Elf32_Ehdr *)elfptr; 1047 1048 rc = update_note_header_size_elf32(ehdr_ptr); 1049 if (rc < 0) 1050 return rc; 1051 1052 rc = get_note_number_and_size_elf32(ehdr_ptr, &nr_ptnote, &phdr_sz); 1053 if (rc < 0) 1054 return rc; 1055 1056 *notes_sz = roundup(phdr_sz, PAGE_SIZE); 1057 *notes_buf = vmcore_alloc_buf(*notes_sz); 1058 if (!*notes_buf) 1059 return -ENOMEM; 1060 1061 rc = copy_notes_elf32(ehdr_ptr, *notes_buf); 1062 if (rc < 0) 1063 return rc; 1064 1065 /* Prepare merged PT_NOTE program header. */ 1066 phdr.p_type = PT_NOTE; 1067 phdr.p_flags = 0; 1068 note_off = sizeof(Elf32_Ehdr) + 1069 (ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf32_Phdr); 1070 phdr.p_offset = roundup(note_off, PAGE_SIZE); 1071 phdr.p_vaddr = phdr.p_paddr = 0; 1072 phdr.p_filesz = phdr.p_memsz = phdr_sz; 1073 phdr.p_align = 0; 1074 1075 /* Add merged PT_NOTE program header*/ 1076 tmp = elfptr + sizeof(Elf32_Ehdr); 1077 memcpy(tmp, &phdr, sizeof(phdr)); 1078 tmp += sizeof(phdr); 1079 1080 /* Remove unwanted PT_NOTE program headers. */ 1081 i = (nr_ptnote - 1) * sizeof(Elf32_Phdr); 1082 *elfsz = *elfsz - i; 1083 memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf32_Ehdr)-sizeof(Elf32_Phdr))); 1084 memset(elfptr + *elfsz, 0, i); 1085 *elfsz = roundup(*elfsz, PAGE_SIZE); 1086 1087 /* Modify e_phnum to reflect merged headers. */ 1088 ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1; 1089 1090 /* Store the size of all notes. We need this to update the note 1091 * header when the device dumps will be added. 1092 */ 1093 elfnotes_orig_sz = phdr.p_memsz; 1094 1095 return 0; 1096 } 1097 1098 /* Add memory chunks represented by program headers to vmcore list. Also update 1099 * the new offset fields of exported program headers. */ 1100 static int __init process_ptload_program_headers_elf64(char *elfptr, 1101 size_t elfsz, 1102 size_t elfnotes_sz, 1103 struct list_head *vc_list) 1104 { 1105 int i; 1106 Elf64_Ehdr *ehdr_ptr; 1107 Elf64_Phdr *phdr_ptr; 1108 loff_t vmcore_off; 1109 struct vmcore *new; 1110 1111 ehdr_ptr = (Elf64_Ehdr *)elfptr; 1112 phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr)); /* PT_NOTE hdr */ 1113 1114 /* Skip Elf header, program headers and Elf note segment. */ 1115 vmcore_off = elfsz + elfnotes_sz; 1116 1117 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { 1118 u64 paddr, start, end, size; 1119 1120 if (phdr_ptr->p_type != PT_LOAD) 1121 continue; 1122 1123 paddr = phdr_ptr->p_offset; 1124 start = rounddown(paddr, PAGE_SIZE); 1125 end = roundup(paddr + phdr_ptr->p_memsz, PAGE_SIZE); 1126 size = end - start; 1127 1128 /* Add this contiguous chunk of memory to vmcore list.*/ 1129 new = get_new_element(); 1130 if (!new) 1131 return -ENOMEM; 1132 new->paddr = start; 1133 new->size = size; 1134 list_add_tail(&new->list, vc_list); 1135 1136 /* Update the program header offset. */ 1137 phdr_ptr->p_offset = vmcore_off + (paddr - start); 1138 vmcore_off = vmcore_off + size; 1139 } 1140 return 0; 1141 } 1142 1143 static int __init process_ptload_program_headers_elf32(char *elfptr, 1144 size_t elfsz, 1145 size_t elfnotes_sz, 1146 struct list_head *vc_list) 1147 { 1148 int i; 1149 Elf32_Ehdr *ehdr_ptr; 1150 Elf32_Phdr *phdr_ptr; 1151 loff_t vmcore_off; 1152 struct vmcore *new; 1153 1154 ehdr_ptr = (Elf32_Ehdr *)elfptr; 1155 phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr)); /* PT_NOTE hdr */ 1156 1157 /* Skip Elf header, program headers and Elf note segment. */ 1158 vmcore_off = elfsz + elfnotes_sz; 1159 1160 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { 1161 u64 paddr, start, end, size; 1162 1163 if (phdr_ptr->p_type != PT_LOAD) 1164 continue; 1165 1166 paddr = phdr_ptr->p_offset; 1167 start = rounddown(paddr, PAGE_SIZE); 1168 end = roundup(paddr + phdr_ptr->p_memsz, PAGE_SIZE); 1169 size = end - start; 1170 1171 /* Add this contiguous chunk of memory to vmcore list.*/ 1172 new = get_new_element(); 1173 if (!new) 1174 return -ENOMEM; 1175 new->paddr = start; 1176 new->size = size; 1177 list_add_tail(&new->list, vc_list); 1178 1179 /* Update the program header offset */ 1180 phdr_ptr->p_offset = vmcore_off + (paddr - start); 1181 vmcore_off = vmcore_off + size; 1182 } 1183 return 0; 1184 } 1185 1186 /* Sets offset fields of vmcore elements. */ 1187 static void set_vmcore_list_offsets(size_t elfsz, size_t elfnotes_sz, 1188 struct list_head *vc_list) 1189 { 1190 loff_t vmcore_off; 1191 struct vmcore *m; 1192 1193 /* Skip Elf header, program headers and Elf note segment. */ 1194 vmcore_off = elfsz + elfnotes_sz; 1195 1196 list_for_each_entry(m, vc_list, list) { 1197 m->offset = vmcore_off; 1198 vmcore_off += m->size; 1199 } 1200 } 1201 1202 static void free_elfcorebuf(void) 1203 { 1204 free_pages((unsigned long)elfcorebuf, get_order(elfcorebuf_sz_orig)); 1205 elfcorebuf = NULL; 1206 vfree(elfnotes_buf); 1207 elfnotes_buf = NULL; 1208 } 1209 1210 static int __init parse_crash_elf64_headers(void) 1211 { 1212 int rc=0; 1213 Elf64_Ehdr ehdr; 1214 u64 addr; 1215 1216 addr = elfcorehdr_addr; 1217 1218 /* Read Elf header */ 1219 rc = elfcorehdr_read((char *)&ehdr, sizeof(Elf64_Ehdr), &addr); 1220 if (rc < 0) 1221 return rc; 1222 1223 /* Do some basic Verification. */ 1224 if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0 || 1225 (ehdr.e_type != ET_CORE) || 1226 !vmcore_elf64_check_arch(&ehdr) || 1227 ehdr.e_ident[EI_CLASS] != ELFCLASS64 || 1228 ehdr.e_ident[EI_VERSION] != EV_CURRENT || 1229 ehdr.e_version != EV_CURRENT || 1230 ehdr.e_ehsize != sizeof(Elf64_Ehdr) || 1231 ehdr.e_phentsize != sizeof(Elf64_Phdr) || 1232 ehdr.e_phnum == 0) { 1233 pr_warn("Warning: Core image elf header is not sane\n"); 1234 return -EINVAL; 1235 } 1236 1237 /* Read in all elf headers. */ 1238 elfcorebuf_sz_orig = sizeof(Elf64_Ehdr) + 1239 ehdr.e_phnum * sizeof(Elf64_Phdr); 1240 elfcorebuf_sz = elfcorebuf_sz_orig; 1241 elfcorebuf = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 1242 get_order(elfcorebuf_sz_orig)); 1243 if (!elfcorebuf) 1244 return -ENOMEM; 1245 addr = elfcorehdr_addr; 1246 rc = elfcorehdr_read(elfcorebuf, elfcorebuf_sz_orig, &addr); 1247 if (rc < 0) 1248 goto fail; 1249 1250 /* Merge all PT_NOTE headers into one. */ 1251 rc = merge_note_headers_elf64(elfcorebuf, &elfcorebuf_sz, 1252 &elfnotes_buf, &elfnotes_sz); 1253 if (rc) 1254 goto fail; 1255 rc = process_ptload_program_headers_elf64(elfcorebuf, elfcorebuf_sz, 1256 elfnotes_sz, &vmcore_list); 1257 if (rc) 1258 goto fail; 1259 set_vmcore_list_offsets(elfcorebuf_sz, elfnotes_sz, &vmcore_list); 1260 return 0; 1261 fail: 1262 free_elfcorebuf(); 1263 return rc; 1264 } 1265 1266 static int __init parse_crash_elf32_headers(void) 1267 { 1268 int rc=0; 1269 Elf32_Ehdr ehdr; 1270 u64 addr; 1271 1272 addr = elfcorehdr_addr; 1273 1274 /* Read Elf header */ 1275 rc = elfcorehdr_read((char *)&ehdr, sizeof(Elf32_Ehdr), &addr); 1276 if (rc < 0) 1277 return rc; 1278 1279 /* Do some basic Verification. */ 1280 if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0 || 1281 (ehdr.e_type != ET_CORE) || 1282 !vmcore_elf32_check_arch(&ehdr) || 1283 ehdr.e_ident[EI_CLASS] != ELFCLASS32|| 1284 ehdr.e_ident[EI_VERSION] != EV_CURRENT || 1285 ehdr.e_version != EV_CURRENT || 1286 ehdr.e_ehsize != sizeof(Elf32_Ehdr) || 1287 ehdr.e_phentsize != sizeof(Elf32_Phdr) || 1288 ehdr.e_phnum == 0) { 1289 pr_warn("Warning: Core image elf header is not sane\n"); 1290 return -EINVAL; 1291 } 1292 1293 /* Read in all elf headers. */ 1294 elfcorebuf_sz_orig = sizeof(Elf32_Ehdr) + ehdr.e_phnum * sizeof(Elf32_Phdr); 1295 elfcorebuf_sz = elfcorebuf_sz_orig; 1296 elfcorebuf = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 1297 get_order(elfcorebuf_sz_orig)); 1298 if (!elfcorebuf) 1299 return -ENOMEM; 1300 addr = elfcorehdr_addr; 1301 rc = elfcorehdr_read(elfcorebuf, elfcorebuf_sz_orig, &addr); 1302 if (rc < 0) 1303 goto fail; 1304 1305 /* Merge all PT_NOTE headers into one. */ 1306 rc = merge_note_headers_elf32(elfcorebuf, &elfcorebuf_sz, 1307 &elfnotes_buf, &elfnotes_sz); 1308 if (rc) 1309 goto fail; 1310 rc = process_ptload_program_headers_elf32(elfcorebuf, elfcorebuf_sz, 1311 elfnotes_sz, &vmcore_list); 1312 if (rc) 1313 goto fail; 1314 set_vmcore_list_offsets(elfcorebuf_sz, elfnotes_sz, &vmcore_list); 1315 return 0; 1316 fail: 1317 free_elfcorebuf(); 1318 return rc; 1319 } 1320 1321 static int __init parse_crash_elf_headers(void) 1322 { 1323 unsigned char e_ident[EI_NIDENT]; 1324 u64 addr; 1325 int rc=0; 1326 1327 addr = elfcorehdr_addr; 1328 rc = elfcorehdr_read(e_ident, EI_NIDENT, &addr); 1329 if (rc < 0) 1330 return rc; 1331 if (memcmp(e_ident, ELFMAG, SELFMAG) != 0) { 1332 pr_warn("Warning: Core image elf header not found\n"); 1333 return -EINVAL; 1334 } 1335 1336 if (e_ident[EI_CLASS] == ELFCLASS64) { 1337 rc = parse_crash_elf64_headers(); 1338 if (rc) 1339 return rc; 1340 } else if (e_ident[EI_CLASS] == ELFCLASS32) { 1341 rc = parse_crash_elf32_headers(); 1342 if (rc) 1343 return rc; 1344 } else { 1345 pr_warn("Warning: Core image elf header is not sane\n"); 1346 return -EINVAL; 1347 } 1348 1349 /* Determine vmcore size. */ 1350 vmcore_size = get_vmcore_size(elfcorebuf_sz, elfnotes_sz, 1351 &vmcore_list); 1352 1353 return 0; 1354 } 1355 1356 #ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP 1357 /** 1358 * vmcoredd_write_header - Write vmcore device dump header at the 1359 * beginning of the dump's buffer. 1360 * @buf: Output buffer where the note is written 1361 * @data: Dump info 1362 * @size: Size of the dump 1363 * 1364 * Fills beginning of the dump's buffer with vmcore device dump header. 1365 */ 1366 static void vmcoredd_write_header(void *buf, struct vmcoredd_data *data, 1367 u32 size) 1368 { 1369 struct vmcoredd_header *vdd_hdr = (struct vmcoredd_header *)buf; 1370 1371 vdd_hdr->n_namesz = sizeof(vdd_hdr->name); 1372 vdd_hdr->n_descsz = size + sizeof(vdd_hdr->dump_name); 1373 vdd_hdr->n_type = NT_VMCOREDD; 1374 1375 strncpy((char *)vdd_hdr->name, VMCOREDD_NOTE_NAME, 1376 sizeof(vdd_hdr->name)); 1377 memcpy(vdd_hdr->dump_name, data->dump_name, sizeof(vdd_hdr->dump_name)); 1378 } 1379 1380 /** 1381 * vmcoredd_update_program_headers - Update all Elf program headers 1382 * @elfptr: Pointer to elf header 1383 * @elfnotesz: Size of elf notes aligned to page size 1384 * @vmcoreddsz: Size of device dumps to be added to elf note header 1385 * 1386 * Determine type of Elf header (Elf64 or Elf32) and update the elf note size. 1387 * Also update the offsets of all the program headers after the elf note header. 1388 */ 1389 static void vmcoredd_update_program_headers(char *elfptr, size_t elfnotesz, 1390 size_t vmcoreddsz) 1391 { 1392 unsigned char *e_ident = (unsigned char *)elfptr; 1393 u64 start, end, size; 1394 loff_t vmcore_off; 1395 u32 i; 1396 1397 vmcore_off = elfcorebuf_sz + elfnotesz; 1398 1399 if (e_ident[EI_CLASS] == ELFCLASS64) { 1400 Elf64_Ehdr *ehdr = (Elf64_Ehdr *)elfptr; 1401 Elf64_Phdr *phdr = (Elf64_Phdr *)(elfptr + sizeof(Elf64_Ehdr)); 1402 1403 /* Update all program headers */ 1404 for (i = 0; i < ehdr->e_phnum; i++, phdr++) { 1405 if (phdr->p_type == PT_NOTE) { 1406 /* Update note size */ 1407 phdr->p_memsz = elfnotes_orig_sz + vmcoreddsz; 1408 phdr->p_filesz = phdr->p_memsz; 1409 continue; 1410 } 1411 1412 start = rounddown(phdr->p_offset, PAGE_SIZE); 1413 end = roundup(phdr->p_offset + phdr->p_memsz, 1414 PAGE_SIZE); 1415 size = end - start; 1416 phdr->p_offset = vmcore_off + (phdr->p_offset - start); 1417 vmcore_off += size; 1418 } 1419 } else { 1420 Elf32_Ehdr *ehdr = (Elf32_Ehdr *)elfptr; 1421 Elf32_Phdr *phdr = (Elf32_Phdr *)(elfptr + sizeof(Elf32_Ehdr)); 1422 1423 /* Update all program headers */ 1424 for (i = 0; i < ehdr->e_phnum; i++, phdr++) { 1425 if (phdr->p_type == PT_NOTE) { 1426 /* Update note size */ 1427 phdr->p_memsz = elfnotes_orig_sz + vmcoreddsz; 1428 phdr->p_filesz = phdr->p_memsz; 1429 continue; 1430 } 1431 1432 start = rounddown(phdr->p_offset, PAGE_SIZE); 1433 end = roundup(phdr->p_offset + phdr->p_memsz, 1434 PAGE_SIZE); 1435 size = end - start; 1436 phdr->p_offset = vmcore_off + (phdr->p_offset - start); 1437 vmcore_off += size; 1438 } 1439 } 1440 } 1441 1442 /** 1443 * vmcoredd_update_size - Update the total size of the device dumps and update 1444 * Elf header 1445 * @dump_size: Size of the current device dump to be added to total size 1446 * 1447 * Update the total size of all the device dumps and update the Elf program 1448 * headers. Calculate the new offsets for the vmcore list and update the 1449 * total vmcore size. 1450 */ 1451 static void vmcoredd_update_size(size_t dump_size) 1452 { 1453 vmcoredd_orig_sz += dump_size; 1454 elfnotes_sz = roundup(elfnotes_orig_sz, PAGE_SIZE) + vmcoredd_orig_sz; 1455 vmcoredd_update_program_headers(elfcorebuf, elfnotes_sz, 1456 vmcoredd_orig_sz); 1457 1458 /* Update vmcore list offsets */ 1459 set_vmcore_list_offsets(elfcorebuf_sz, elfnotes_sz, &vmcore_list); 1460 1461 vmcore_size = get_vmcore_size(elfcorebuf_sz, elfnotes_sz, 1462 &vmcore_list); 1463 proc_vmcore->size = vmcore_size; 1464 } 1465 1466 /** 1467 * vmcore_add_device_dump - Add a buffer containing device dump to vmcore 1468 * @data: dump info. 1469 * 1470 * Allocate a buffer and invoke the calling driver's dump collect routine. 1471 * Write Elf note at the beginning of the buffer to indicate vmcore device 1472 * dump and add the dump to global list. 1473 */ 1474 int vmcore_add_device_dump(struct vmcoredd_data *data) 1475 { 1476 struct vmcoredd_node *dump; 1477 void *buf = NULL; 1478 size_t data_size; 1479 int ret; 1480 1481 if (vmcoredd_disabled) { 1482 pr_err_once("Device dump is disabled\n"); 1483 return -EINVAL; 1484 } 1485 1486 if (!data || !strlen(data->dump_name) || 1487 !data->vmcoredd_callback || !data->size) 1488 return -EINVAL; 1489 1490 dump = vzalloc(sizeof(*dump)); 1491 if (!dump) { 1492 ret = -ENOMEM; 1493 goto out_err; 1494 } 1495 1496 /* Keep size of the buffer page aligned so that it can be mmaped */ 1497 data_size = roundup(sizeof(struct vmcoredd_header) + data->size, 1498 PAGE_SIZE); 1499 1500 /* Allocate buffer for driver's to write their dumps */ 1501 buf = vmcore_alloc_buf(data_size); 1502 if (!buf) { 1503 ret = -ENOMEM; 1504 goto out_err; 1505 } 1506 1507 vmcoredd_write_header(buf, data, data_size - 1508 sizeof(struct vmcoredd_header)); 1509 1510 /* Invoke the driver's dump collection routing */ 1511 ret = data->vmcoredd_callback(data, buf + 1512 sizeof(struct vmcoredd_header)); 1513 if (ret) 1514 goto out_err; 1515 1516 dump->buf = buf; 1517 dump->size = data_size; 1518 1519 /* Add the dump to driver sysfs list */ 1520 mutex_lock(&vmcoredd_mutex); 1521 list_add_tail(&dump->list, &vmcoredd_list); 1522 mutex_unlock(&vmcoredd_mutex); 1523 1524 vmcoredd_update_size(data_size); 1525 return 0; 1526 1527 out_err: 1528 vfree(buf); 1529 vfree(dump); 1530 1531 return ret; 1532 } 1533 EXPORT_SYMBOL(vmcore_add_device_dump); 1534 #endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */ 1535 1536 /* Free all dumps in vmcore device dump list */ 1537 static void vmcore_free_device_dumps(void) 1538 { 1539 #ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP 1540 mutex_lock(&vmcoredd_mutex); 1541 while (!list_empty(&vmcoredd_list)) { 1542 struct vmcoredd_node *dump; 1543 1544 dump = list_first_entry(&vmcoredd_list, struct vmcoredd_node, 1545 list); 1546 list_del(&dump->list); 1547 vfree(dump->buf); 1548 vfree(dump); 1549 } 1550 mutex_unlock(&vmcoredd_mutex); 1551 #endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */ 1552 } 1553 1554 /* Init function for vmcore module. */ 1555 static int __init vmcore_init(void) 1556 { 1557 int rc = 0; 1558 1559 /* Allow architectures to allocate ELF header in 2nd kernel */ 1560 rc = elfcorehdr_alloc(&elfcorehdr_addr, &elfcorehdr_size); 1561 if (rc) 1562 return rc; 1563 /* 1564 * If elfcorehdr= has been passed in cmdline or created in 2nd kernel, 1565 * then capture the dump. 1566 */ 1567 if (!(is_vmcore_usable())) 1568 return rc; 1569 rc = parse_crash_elf_headers(); 1570 if (rc) { 1571 pr_warn("Kdump: vmcore not initialized\n"); 1572 return rc; 1573 } 1574 elfcorehdr_free(elfcorehdr_addr); 1575 elfcorehdr_addr = ELFCORE_ADDR_ERR; 1576 1577 proc_vmcore = proc_create("vmcore", S_IRUSR, NULL, &vmcore_proc_ops); 1578 if (proc_vmcore) 1579 proc_vmcore->size = vmcore_size; 1580 return 0; 1581 } 1582 fs_initcall(vmcore_init); 1583 1584 /* Cleanup function for vmcore module. */ 1585 void vmcore_cleanup(void) 1586 { 1587 if (proc_vmcore) { 1588 proc_remove(proc_vmcore); 1589 proc_vmcore = NULL; 1590 } 1591 1592 /* clear the vmcore list. */ 1593 while (!list_empty(&vmcore_list)) { 1594 struct vmcore *m; 1595 1596 m = list_first_entry(&vmcore_list, struct vmcore, list); 1597 list_del(&m->list); 1598 kfree(m); 1599 } 1600 free_elfcorebuf(); 1601 1602 /* clear vmcore device dump list */ 1603 vmcore_free_device_dumps(); 1604 } 1605