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 vma->vm_flags &= ~(VM_MAYWRITE | VM_MAYEXEC); 586 vma->vm_flags |= VM_MIXEDMAP; 587 vma->vm_ops = &vmcore_mmap_ops; 588 589 len = 0; 590 591 if (start < elfcorebuf_sz) { 592 u64 pfn; 593 594 tsz = min(elfcorebuf_sz - (size_t)start, size); 595 pfn = __pa(elfcorebuf + start) >> PAGE_SHIFT; 596 if (remap_pfn_range(vma, vma->vm_start, pfn, tsz, 597 vma->vm_page_prot)) 598 return -EAGAIN; 599 size -= tsz; 600 start += tsz; 601 len += tsz; 602 603 if (size == 0) 604 return 0; 605 } 606 607 if (start < elfcorebuf_sz + elfnotes_sz) { 608 void *kaddr; 609 610 /* We add device dumps before other elf notes because the 611 * other elf notes may not fill the elf notes buffer 612 * completely and we will end up with zero-filled data 613 * between the elf notes and the device dumps. Tools will 614 * then try to decode this zero-filled data as valid notes 615 * and we don't want that. Hence, adding device dumps before 616 * the other elf notes ensure that zero-filled data can be 617 * avoided. This also ensures that the device dumps and 618 * other elf notes can be properly mmaped at page aligned 619 * address. 620 */ 621 #ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP 622 /* Read device dumps */ 623 if (start < elfcorebuf_sz + vmcoredd_orig_sz) { 624 u64 start_off; 625 626 tsz = min(elfcorebuf_sz + vmcoredd_orig_sz - 627 (size_t)start, size); 628 start_off = start - elfcorebuf_sz; 629 if (vmcoredd_mmap_dumps(vma, vma->vm_start + len, 630 start_off, tsz)) 631 goto fail; 632 633 size -= tsz; 634 start += tsz; 635 len += tsz; 636 637 /* leave now if filled buffer already */ 638 if (!size) 639 return 0; 640 } 641 #endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */ 642 643 /* Read remaining elf notes */ 644 tsz = min(elfcorebuf_sz + elfnotes_sz - (size_t)start, size); 645 kaddr = elfnotes_buf + start - elfcorebuf_sz - vmcoredd_orig_sz; 646 if (remap_vmalloc_range_partial(vma, vma->vm_start + len, 647 kaddr, 0, tsz)) 648 goto fail; 649 650 size -= tsz; 651 start += tsz; 652 len += tsz; 653 654 if (size == 0) 655 return 0; 656 } 657 658 list_for_each_entry(m, &vmcore_list, list) { 659 if (start < m->offset + m->size) { 660 u64 paddr = 0; 661 662 tsz = (size_t)min_t(unsigned long long, 663 m->offset + m->size - start, size); 664 paddr = m->paddr + start - m->offset; 665 if (vmcore_remap_oldmem_pfn(vma, vma->vm_start + len, 666 paddr >> PAGE_SHIFT, tsz, 667 vma->vm_page_prot)) 668 goto fail; 669 size -= tsz; 670 start += tsz; 671 len += tsz; 672 673 if (size == 0) 674 return 0; 675 } 676 } 677 678 return 0; 679 fail: 680 do_munmap(vma->vm_mm, vma->vm_start, len, NULL); 681 return -EAGAIN; 682 } 683 #else 684 static int mmap_vmcore(struct file *file, struct vm_area_struct *vma) 685 { 686 return -ENOSYS; 687 } 688 #endif 689 690 static const struct proc_ops vmcore_proc_ops = { 691 .proc_open = open_vmcore, 692 .proc_read_iter = read_vmcore, 693 .proc_lseek = default_llseek, 694 .proc_mmap = mmap_vmcore, 695 }; 696 697 static struct vmcore* __init get_new_element(void) 698 { 699 return kzalloc(sizeof(struct vmcore), GFP_KERNEL); 700 } 701 702 static u64 get_vmcore_size(size_t elfsz, size_t elfnotesegsz, 703 struct list_head *vc_list) 704 { 705 u64 size; 706 struct vmcore *m; 707 708 size = elfsz + elfnotesegsz; 709 list_for_each_entry(m, vc_list, list) { 710 size += m->size; 711 } 712 return size; 713 } 714 715 /** 716 * update_note_header_size_elf64 - update p_memsz member of each PT_NOTE entry 717 * 718 * @ehdr_ptr: ELF header 719 * 720 * This function updates p_memsz member of each PT_NOTE entry in the 721 * program header table pointed to by @ehdr_ptr to real size of ELF 722 * note segment. 723 */ 724 static int __init update_note_header_size_elf64(const Elf64_Ehdr *ehdr_ptr) 725 { 726 int i, rc=0; 727 Elf64_Phdr *phdr_ptr; 728 Elf64_Nhdr *nhdr_ptr; 729 730 phdr_ptr = (Elf64_Phdr *)(ehdr_ptr + 1); 731 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { 732 void *notes_section; 733 u64 offset, max_sz, sz, real_sz = 0; 734 if (phdr_ptr->p_type != PT_NOTE) 735 continue; 736 max_sz = phdr_ptr->p_memsz; 737 offset = phdr_ptr->p_offset; 738 notes_section = kmalloc(max_sz, GFP_KERNEL); 739 if (!notes_section) 740 return -ENOMEM; 741 rc = elfcorehdr_read_notes(notes_section, max_sz, &offset); 742 if (rc < 0) { 743 kfree(notes_section); 744 return rc; 745 } 746 nhdr_ptr = notes_section; 747 while (nhdr_ptr->n_namesz != 0) { 748 sz = sizeof(Elf64_Nhdr) + 749 (((u64)nhdr_ptr->n_namesz + 3) & ~3) + 750 (((u64)nhdr_ptr->n_descsz + 3) & ~3); 751 if ((real_sz + sz) > max_sz) { 752 pr_warn("Warning: Exceeded p_memsz, dropping PT_NOTE entry n_namesz=0x%x, n_descsz=0x%x\n", 753 nhdr_ptr->n_namesz, nhdr_ptr->n_descsz); 754 break; 755 } 756 real_sz += sz; 757 nhdr_ptr = (Elf64_Nhdr*)((char*)nhdr_ptr + sz); 758 } 759 kfree(notes_section); 760 phdr_ptr->p_memsz = real_sz; 761 if (real_sz == 0) { 762 pr_warn("Warning: Zero PT_NOTE entries found\n"); 763 } 764 } 765 766 return 0; 767 } 768 769 /** 770 * get_note_number_and_size_elf64 - get the number of PT_NOTE program 771 * headers and sum of real size of their ELF note segment headers and 772 * data. 773 * 774 * @ehdr_ptr: ELF header 775 * @nr_ptnote: buffer for the number of PT_NOTE program headers 776 * @sz_ptnote: buffer for size of unique PT_NOTE program header 777 * 778 * This function is used to merge multiple PT_NOTE program headers 779 * into a unique single one. The resulting unique entry will have 780 * @sz_ptnote in its phdr->p_mem. 781 * 782 * It is assumed that program headers with PT_NOTE type pointed to by 783 * @ehdr_ptr has already been updated by update_note_header_size_elf64 784 * and each of PT_NOTE program headers has actual ELF note segment 785 * size in its p_memsz member. 786 */ 787 static int __init get_note_number_and_size_elf64(const Elf64_Ehdr *ehdr_ptr, 788 int *nr_ptnote, u64 *sz_ptnote) 789 { 790 int i; 791 Elf64_Phdr *phdr_ptr; 792 793 *nr_ptnote = *sz_ptnote = 0; 794 795 phdr_ptr = (Elf64_Phdr *)(ehdr_ptr + 1); 796 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { 797 if (phdr_ptr->p_type != PT_NOTE) 798 continue; 799 *nr_ptnote += 1; 800 *sz_ptnote += phdr_ptr->p_memsz; 801 } 802 803 return 0; 804 } 805 806 /** 807 * copy_notes_elf64 - copy ELF note segments in a given buffer 808 * 809 * @ehdr_ptr: ELF header 810 * @notes_buf: buffer into which ELF note segments are copied 811 * 812 * This function is used to copy ELF note segment in the 1st kernel 813 * into the buffer @notes_buf in the 2nd kernel. It is assumed that 814 * size of the buffer @notes_buf is equal to or larger than sum of the 815 * real ELF note segment headers and data. 816 * 817 * It is assumed that program headers with PT_NOTE type pointed to by 818 * @ehdr_ptr has already been updated by update_note_header_size_elf64 819 * and each of PT_NOTE program headers has actual ELF note segment 820 * size in its p_memsz member. 821 */ 822 static int __init copy_notes_elf64(const Elf64_Ehdr *ehdr_ptr, char *notes_buf) 823 { 824 int i, rc=0; 825 Elf64_Phdr *phdr_ptr; 826 827 phdr_ptr = (Elf64_Phdr*)(ehdr_ptr + 1); 828 829 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { 830 u64 offset; 831 if (phdr_ptr->p_type != PT_NOTE) 832 continue; 833 offset = phdr_ptr->p_offset; 834 rc = elfcorehdr_read_notes(notes_buf, phdr_ptr->p_memsz, 835 &offset); 836 if (rc < 0) 837 return rc; 838 notes_buf += phdr_ptr->p_memsz; 839 } 840 841 return 0; 842 } 843 844 /* Merges all the PT_NOTE headers into one. */ 845 static int __init merge_note_headers_elf64(char *elfptr, size_t *elfsz, 846 char **notes_buf, size_t *notes_sz) 847 { 848 int i, nr_ptnote=0, rc=0; 849 char *tmp; 850 Elf64_Ehdr *ehdr_ptr; 851 Elf64_Phdr phdr; 852 u64 phdr_sz = 0, note_off; 853 854 ehdr_ptr = (Elf64_Ehdr *)elfptr; 855 856 rc = update_note_header_size_elf64(ehdr_ptr); 857 if (rc < 0) 858 return rc; 859 860 rc = get_note_number_and_size_elf64(ehdr_ptr, &nr_ptnote, &phdr_sz); 861 if (rc < 0) 862 return rc; 863 864 *notes_sz = roundup(phdr_sz, PAGE_SIZE); 865 *notes_buf = vmcore_alloc_buf(*notes_sz); 866 if (!*notes_buf) 867 return -ENOMEM; 868 869 rc = copy_notes_elf64(ehdr_ptr, *notes_buf); 870 if (rc < 0) 871 return rc; 872 873 /* Prepare merged PT_NOTE program header. */ 874 phdr.p_type = PT_NOTE; 875 phdr.p_flags = 0; 876 note_off = sizeof(Elf64_Ehdr) + 877 (ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf64_Phdr); 878 phdr.p_offset = roundup(note_off, PAGE_SIZE); 879 phdr.p_vaddr = phdr.p_paddr = 0; 880 phdr.p_filesz = phdr.p_memsz = phdr_sz; 881 phdr.p_align = 0; 882 883 /* Add merged PT_NOTE program header*/ 884 tmp = elfptr + sizeof(Elf64_Ehdr); 885 memcpy(tmp, &phdr, sizeof(phdr)); 886 tmp += sizeof(phdr); 887 888 /* Remove unwanted PT_NOTE program headers. */ 889 i = (nr_ptnote - 1) * sizeof(Elf64_Phdr); 890 *elfsz = *elfsz - i; 891 memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf64_Ehdr)-sizeof(Elf64_Phdr))); 892 memset(elfptr + *elfsz, 0, i); 893 *elfsz = roundup(*elfsz, PAGE_SIZE); 894 895 /* Modify e_phnum to reflect merged headers. */ 896 ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1; 897 898 /* Store the size of all notes. We need this to update the note 899 * header when the device dumps will be added. 900 */ 901 elfnotes_orig_sz = phdr.p_memsz; 902 903 return 0; 904 } 905 906 /** 907 * update_note_header_size_elf32 - update p_memsz member of each PT_NOTE entry 908 * 909 * @ehdr_ptr: ELF header 910 * 911 * This function updates p_memsz member of each PT_NOTE entry in the 912 * program header table pointed to by @ehdr_ptr to real size of ELF 913 * note segment. 914 */ 915 static int __init update_note_header_size_elf32(const Elf32_Ehdr *ehdr_ptr) 916 { 917 int i, rc=0; 918 Elf32_Phdr *phdr_ptr; 919 Elf32_Nhdr *nhdr_ptr; 920 921 phdr_ptr = (Elf32_Phdr *)(ehdr_ptr + 1); 922 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { 923 void *notes_section; 924 u64 offset, max_sz, sz, real_sz = 0; 925 if (phdr_ptr->p_type != PT_NOTE) 926 continue; 927 max_sz = phdr_ptr->p_memsz; 928 offset = phdr_ptr->p_offset; 929 notes_section = kmalloc(max_sz, GFP_KERNEL); 930 if (!notes_section) 931 return -ENOMEM; 932 rc = elfcorehdr_read_notes(notes_section, max_sz, &offset); 933 if (rc < 0) { 934 kfree(notes_section); 935 return rc; 936 } 937 nhdr_ptr = notes_section; 938 while (nhdr_ptr->n_namesz != 0) { 939 sz = sizeof(Elf32_Nhdr) + 940 (((u64)nhdr_ptr->n_namesz + 3) & ~3) + 941 (((u64)nhdr_ptr->n_descsz + 3) & ~3); 942 if ((real_sz + sz) > max_sz) { 943 pr_warn("Warning: Exceeded p_memsz, dropping PT_NOTE entry n_namesz=0x%x, n_descsz=0x%x\n", 944 nhdr_ptr->n_namesz, nhdr_ptr->n_descsz); 945 break; 946 } 947 real_sz += sz; 948 nhdr_ptr = (Elf32_Nhdr*)((char*)nhdr_ptr + sz); 949 } 950 kfree(notes_section); 951 phdr_ptr->p_memsz = real_sz; 952 if (real_sz == 0) { 953 pr_warn("Warning: Zero PT_NOTE entries found\n"); 954 } 955 } 956 957 return 0; 958 } 959 960 /** 961 * get_note_number_and_size_elf32 - get the number of PT_NOTE program 962 * headers and sum of real size of their ELF note segment headers and 963 * data. 964 * 965 * @ehdr_ptr: ELF header 966 * @nr_ptnote: buffer for the number of PT_NOTE program headers 967 * @sz_ptnote: buffer for size of unique PT_NOTE program header 968 * 969 * This function is used to merge multiple PT_NOTE program headers 970 * into a unique single one. The resulting unique entry will have 971 * @sz_ptnote in its phdr->p_mem. 972 * 973 * It is assumed that program headers with PT_NOTE type pointed to by 974 * @ehdr_ptr has already been updated by update_note_header_size_elf32 975 * and each of PT_NOTE program headers has actual ELF note segment 976 * size in its p_memsz member. 977 */ 978 static int __init get_note_number_and_size_elf32(const Elf32_Ehdr *ehdr_ptr, 979 int *nr_ptnote, u64 *sz_ptnote) 980 { 981 int i; 982 Elf32_Phdr *phdr_ptr; 983 984 *nr_ptnote = *sz_ptnote = 0; 985 986 phdr_ptr = (Elf32_Phdr *)(ehdr_ptr + 1); 987 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { 988 if (phdr_ptr->p_type != PT_NOTE) 989 continue; 990 *nr_ptnote += 1; 991 *sz_ptnote += phdr_ptr->p_memsz; 992 } 993 994 return 0; 995 } 996 997 /** 998 * copy_notes_elf32 - copy ELF note segments in a given buffer 999 * 1000 * @ehdr_ptr: ELF header 1001 * @notes_buf: buffer into which ELF note segments are copied 1002 * 1003 * This function is used to copy ELF note segment in the 1st kernel 1004 * into the buffer @notes_buf in the 2nd kernel. It is assumed that 1005 * size of the buffer @notes_buf is equal to or larger than sum of the 1006 * real ELF note segment headers and data. 1007 * 1008 * It is assumed that program headers with PT_NOTE type pointed to by 1009 * @ehdr_ptr has already been updated by update_note_header_size_elf32 1010 * and each of PT_NOTE program headers has actual ELF note segment 1011 * size in its p_memsz member. 1012 */ 1013 static int __init copy_notes_elf32(const Elf32_Ehdr *ehdr_ptr, char *notes_buf) 1014 { 1015 int i, rc=0; 1016 Elf32_Phdr *phdr_ptr; 1017 1018 phdr_ptr = (Elf32_Phdr*)(ehdr_ptr + 1); 1019 1020 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { 1021 u64 offset; 1022 if (phdr_ptr->p_type != PT_NOTE) 1023 continue; 1024 offset = phdr_ptr->p_offset; 1025 rc = elfcorehdr_read_notes(notes_buf, phdr_ptr->p_memsz, 1026 &offset); 1027 if (rc < 0) 1028 return rc; 1029 notes_buf += phdr_ptr->p_memsz; 1030 } 1031 1032 return 0; 1033 } 1034 1035 /* Merges all the PT_NOTE headers into one. */ 1036 static int __init merge_note_headers_elf32(char *elfptr, size_t *elfsz, 1037 char **notes_buf, size_t *notes_sz) 1038 { 1039 int i, nr_ptnote=0, rc=0; 1040 char *tmp; 1041 Elf32_Ehdr *ehdr_ptr; 1042 Elf32_Phdr phdr; 1043 u64 phdr_sz = 0, note_off; 1044 1045 ehdr_ptr = (Elf32_Ehdr *)elfptr; 1046 1047 rc = update_note_header_size_elf32(ehdr_ptr); 1048 if (rc < 0) 1049 return rc; 1050 1051 rc = get_note_number_and_size_elf32(ehdr_ptr, &nr_ptnote, &phdr_sz); 1052 if (rc < 0) 1053 return rc; 1054 1055 *notes_sz = roundup(phdr_sz, PAGE_SIZE); 1056 *notes_buf = vmcore_alloc_buf(*notes_sz); 1057 if (!*notes_buf) 1058 return -ENOMEM; 1059 1060 rc = copy_notes_elf32(ehdr_ptr, *notes_buf); 1061 if (rc < 0) 1062 return rc; 1063 1064 /* Prepare merged PT_NOTE program header. */ 1065 phdr.p_type = PT_NOTE; 1066 phdr.p_flags = 0; 1067 note_off = sizeof(Elf32_Ehdr) + 1068 (ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf32_Phdr); 1069 phdr.p_offset = roundup(note_off, PAGE_SIZE); 1070 phdr.p_vaddr = phdr.p_paddr = 0; 1071 phdr.p_filesz = phdr.p_memsz = phdr_sz; 1072 phdr.p_align = 0; 1073 1074 /* Add merged PT_NOTE program header*/ 1075 tmp = elfptr + sizeof(Elf32_Ehdr); 1076 memcpy(tmp, &phdr, sizeof(phdr)); 1077 tmp += sizeof(phdr); 1078 1079 /* Remove unwanted PT_NOTE program headers. */ 1080 i = (nr_ptnote - 1) * sizeof(Elf32_Phdr); 1081 *elfsz = *elfsz - i; 1082 memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf32_Ehdr)-sizeof(Elf32_Phdr))); 1083 memset(elfptr + *elfsz, 0, i); 1084 *elfsz = roundup(*elfsz, PAGE_SIZE); 1085 1086 /* Modify e_phnum to reflect merged headers. */ 1087 ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1; 1088 1089 /* Store the size of all notes. We need this to update the note 1090 * header when the device dumps will be added. 1091 */ 1092 elfnotes_orig_sz = phdr.p_memsz; 1093 1094 return 0; 1095 } 1096 1097 /* Add memory chunks represented by program headers to vmcore list. Also update 1098 * the new offset fields of exported program headers. */ 1099 static int __init process_ptload_program_headers_elf64(char *elfptr, 1100 size_t elfsz, 1101 size_t elfnotes_sz, 1102 struct list_head *vc_list) 1103 { 1104 int i; 1105 Elf64_Ehdr *ehdr_ptr; 1106 Elf64_Phdr *phdr_ptr; 1107 loff_t vmcore_off; 1108 struct vmcore *new; 1109 1110 ehdr_ptr = (Elf64_Ehdr *)elfptr; 1111 phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr)); /* PT_NOTE hdr */ 1112 1113 /* Skip Elf header, program headers and Elf note segment. */ 1114 vmcore_off = elfsz + elfnotes_sz; 1115 1116 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { 1117 u64 paddr, start, end, size; 1118 1119 if (phdr_ptr->p_type != PT_LOAD) 1120 continue; 1121 1122 paddr = phdr_ptr->p_offset; 1123 start = rounddown(paddr, PAGE_SIZE); 1124 end = roundup(paddr + phdr_ptr->p_memsz, PAGE_SIZE); 1125 size = end - start; 1126 1127 /* Add this contiguous chunk of memory to vmcore list.*/ 1128 new = get_new_element(); 1129 if (!new) 1130 return -ENOMEM; 1131 new->paddr = start; 1132 new->size = size; 1133 list_add_tail(&new->list, vc_list); 1134 1135 /* Update the program header offset. */ 1136 phdr_ptr->p_offset = vmcore_off + (paddr - start); 1137 vmcore_off = vmcore_off + size; 1138 } 1139 return 0; 1140 } 1141 1142 static int __init process_ptload_program_headers_elf32(char *elfptr, 1143 size_t elfsz, 1144 size_t elfnotes_sz, 1145 struct list_head *vc_list) 1146 { 1147 int i; 1148 Elf32_Ehdr *ehdr_ptr; 1149 Elf32_Phdr *phdr_ptr; 1150 loff_t vmcore_off; 1151 struct vmcore *new; 1152 1153 ehdr_ptr = (Elf32_Ehdr *)elfptr; 1154 phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr)); /* PT_NOTE hdr */ 1155 1156 /* Skip Elf header, program headers and Elf note segment. */ 1157 vmcore_off = elfsz + elfnotes_sz; 1158 1159 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { 1160 u64 paddr, start, end, size; 1161 1162 if (phdr_ptr->p_type != PT_LOAD) 1163 continue; 1164 1165 paddr = phdr_ptr->p_offset; 1166 start = rounddown(paddr, PAGE_SIZE); 1167 end = roundup(paddr + phdr_ptr->p_memsz, PAGE_SIZE); 1168 size = end - start; 1169 1170 /* Add this contiguous chunk of memory to vmcore list.*/ 1171 new = get_new_element(); 1172 if (!new) 1173 return -ENOMEM; 1174 new->paddr = start; 1175 new->size = size; 1176 list_add_tail(&new->list, vc_list); 1177 1178 /* Update the program header offset */ 1179 phdr_ptr->p_offset = vmcore_off + (paddr - start); 1180 vmcore_off = vmcore_off + size; 1181 } 1182 return 0; 1183 } 1184 1185 /* Sets offset fields of vmcore elements. */ 1186 static void set_vmcore_list_offsets(size_t elfsz, size_t elfnotes_sz, 1187 struct list_head *vc_list) 1188 { 1189 loff_t vmcore_off; 1190 struct vmcore *m; 1191 1192 /* Skip Elf header, program headers and Elf note segment. */ 1193 vmcore_off = elfsz + elfnotes_sz; 1194 1195 list_for_each_entry(m, vc_list, list) { 1196 m->offset = vmcore_off; 1197 vmcore_off += m->size; 1198 } 1199 } 1200 1201 static void free_elfcorebuf(void) 1202 { 1203 free_pages((unsigned long)elfcorebuf, get_order(elfcorebuf_sz_orig)); 1204 elfcorebuf = NULL; 1205 vfree(elfnotes_buf); 1206 elfnotes_buf = NULL; 1207 } 1208 1209 static int __init parse_crash_elf64_headers(void) 1210 { 1211 int rc=0; 1212 Elf64_Ehdr ehdr; 1213 u64 addr; 1214 1215 addr = elfcorehdr_addr; 1216 1217 /* Read Elf header */ 1218 rc = elfcorehdr_read((char *)&ehdr, sizeof(Elf64_Ehdr), &addr); 1219 if (rc < 0) 1220 return rc; 1221 1222 /* Do some basic Verification. */ 1223 if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0 || 1224 (ehdr.e_type != ET_CORE) || 1225 !vmcore_elf64_check_arch(&ehdr) || 1226 ehdr.e_ident[EI_CLASS] != ELFCLASS64 || 1227 ehdr.e_ident[EI_VERSION] != EV_CURRENT || 1228 ehdr.e_version != EV_CURRENT || 1229 ehdr.e_ehsize != sizeof(Elf64_Ehdr) || 1230 ehdr.e_phentsize != sizeof(Elf64_Phdr) || 1231 ehdr.e_phnum == 0) { 1232 pr_warn("Warning: Core image elf header is not sane\n"); 1233 return -EINVAL; 1234 } 1235 1236 /* Read in all elf headers. */ 1237 elfcorebuf_sz_orig = sizeof(Elf64_Ehdr) + 1238 ehdr.e_phnum * sizeof(Elf64_Phdr); 1239 elfcorebuf_sz = elfcorebuf_sz_orig; 1240 elfcorebuf = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 1241 get_order(elfcorebuf_sz_orig)); 1242 if (!elfcorebuf) 1243 return -ENOMEM; 1244 addr = elfcorehdr_addr; 1245 rc = elfcorehdr_read(elfcorebuf, elfcorebuf_sz_orig, &addr); 1246 if (rc < 0) 1247 goto fail; 1248 1249 /* Merge all PT_NOTE headers into one. */ 1250 rc = merge_note_headers_elf64(elfcorebuf, &elfcorebuf_sz, 1251 &elfnotes_buf, &elfnotes_sz); 1252 if (rc) 1253 goto fail; 1254 rc = process_ptload_program_headers_elf64(elfcorebuf, elfcorebuf_sz, 1255 elfnotes_sz, &vmcore_list); 1256 if (rc) 1257 goto fail; 1258 set_vmcore_list_offsets(elfcorebuf_sz, elfnotes_sz, &vmcore_list); 1259 return 0; 1260 fail: 1261 free_elfcorebuf(); 1262 return rc; 1263 } 1264 1265 static int __init parse_crash_elf32_headers(void) 1266 { 1267 int rc=0; 1268 Elf32_Ehdr ehdr; 1269 u64 addr; 1270 1271 addr = elfcorehdr_addr; 1272 1273 /* Read Elf header */ 1274 rc = elfcorehdr_read((char *)&ehdr, sizeof(Elf32_Ehdr), &addr); 1275 if (rc < 0) 1276 return rc; 1277 1278 /* Do some basic Verification. */ 1279 if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0 || 1280 (ehdr.e_type != ET_CORE) || 1281 !vmcore_elf32_check_arch(&ehdr) || 1282 ehdr.e_ident[EI_CLASS] != ELFCLASS32|| 1283 ehdr.e_ident[EI_VERSION] != EV_CURRENT || 1284 ehdr.e_version != EV_CURRENT || 1285 ehdr.e_ehsize != sizeof(Elf32_Ehdr) || 1286 ehdr.e_phentsize != sizeof(Elf32_Phdr) || 1287 ehdr.e_phnum == 0) { 1288 pr_warn("Warning: Core image elf header is not sane\n"); 1289 return -EINVAL; 1290 } 1291 1292 /* Read in all elf headers. */ 1293 elfcorebuf_sz_orig = sizeof(Elf32_Ehdr) + ehdr.e_phnum * sizeof(Elf32_Phdr); 1294 elfcorebuf_sz = elfcorebuf_sz_orig; 1295 elfcorebuf = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 1296 get_order(elfcorebuf_sz_orig)); 1297 if (!elfcorebuf) 1298 return -ENOMEM; 1299 addr = elfcorehdr_addr; 1300 rc = elfcorehdr_read(elfcorebuf, elfcorebuf_sz_orig, &addr); 1301 if (rc < 0) 1302 goto fail; 1303 1304 /* Merge all PT_NOTE headers into one. */ 1305 rc = merge_note_headers_elf32(elfcorebuf, &elfcorebuf_sz, 1306 &elfnotes_buf, &elfnotes_sz); 1307 if (rc) 1308 goto fail; 1309 rc = process_ptload_program_headers_elf32(elfcorebuf, elfcorebuf_sz, 1310 elfnotes_sz, &vmcore_list); 1311 if (rc) 1312 goto fail; 1313 set_vmcore_list_offsets(elfcorebuf_sz, elfnotes_sz, &vmcore_list); 1314 return 0; 1315 fail: 1316 free_elfcorebuf(); 1317 return rc; 1318 } 1319 1320 static int __init parse_crash_elf_headers(void) 1321 { 1322 unsigned char e_ident[EI_NIDENT]; 1323 u64 addr; 1324 int rc=0; 1325 1326 addr = elfcorehdr_addr; 1327 rc = elfcorehdr_read(e_ident, EI_NIDENT, &addr); 1328 if (rc < 0) 1329 return rc; 1330 if (memcmp(e_ident, ELFMAG, SELFMAG) != 0) { 1331 pr_warn("Warning: Core image elf header not found\n"); 1332 return -EINVAL; 1333 } 1334 1335 if (e_ident[EI_CLASS] == ELFCLASS64) { 1336 rc = parse_crash_elf64_headers(); 1337 if (rc) 1338 return rc; 1339 } else if (e_ident[EI_CLASS] == ELFCLASS32) { 1340 rc = parse_crash_elf32_headers(); 1341 if (rc) 1342 return rc; 1343 } else { 1344 pr_warn("Warning: Core image elf header is not sane\n"); 1345 return -EINVAL; 1346 } 1347 1348 /* Determine vmcore size. */ 1349 vmcore_size = get_vmcore_size(elfcorebuf_sz, elfnotes_sz, 1350 &vmcore_list); 1351 1352 return 0; 1353 } 1354 1355 #ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP 1356 /** 1357 * vmcoredd_write_header - Write vmcore device dump header at the 1358 * beginning of the dump's buffer. 1359 * @buf: Output buffer where the note is written 1360 * @data: Dump info 1361 * @size: Size of the dump 1362 * 1363 * Fills beginning of the dump's buffer with vmcore device dump header. 1364 */ 1365 static void vmcoredd_write_header(void *buf, struct vmcoredd_data *data, 1366 u32 size) 1367 { 1368 struct vmcoredd_header *vdd_hdr = (struct vmcoredd_header *)buf; 1369 1370 vdd_hdr->n_namesz = sizeof(vdd_hdr->name); 1371 vdd_hdr->n_descsz = size + sizeof(vdd_hdr->dump_name); 1372 vdd_hdr->n_type = NT_VMCOREDD; 1373 1374 strncpy((char *)vdd_hdr->name, VMCOREDD_NOTE_NAME, 1375 sizeof(vdd_hdr->name)); 1376 memcpy(vdd_hdr->dump_name, data->dump_name, sizeof(vdd_hdr->dump_name)); 1377 } 1378 1379 /** 1380 * vmcoredd_update_program_headers - Update all Elf program headers 1381 * @elfptr: Pointer to elf header 1382 * @elfnotesz: Size of elf notes aligned to page size 1383 * @vmcoreddsz: Size of device dumps to be added to elf note header 1384 * 1385 * Determine type of Elf header (Elf64 or Elf32) and update the elf note size. 1386 * Also update the offsets of all the program headers after the elf note header. 1387 */ 1388 static void vmcoredd_update_program_headers(char *elfptr, size_t elfnotesz, 1389 size_t vmcoreddsz) 1390 { 1391 unsigned char *e_ident = (unsigned char *)elfptr; 1392 u64 start, end, size; 1393 loff_t vmcore_off; 1394 u32 i; 1395 1396 vmcore_off = elfcorebuf_sz + elfnotesz; 1397 1398 if (e_ident[EI_CLASS] == ELFCLASS64) { 1399 Elf64_Ehdr *ehdr = (Elf64_Ehdr *)elfptr; 1400 Elf64_Phdr *phdr = (Elf64_Phdr *)(elfptr + sizeof(Elf64_Ehdr)); 1401 1402 /* Update all program headers */ 1403 for (i = 0; i < ehdr->e_phnum; i++, phdr++) { 1404 if (phdr->p_type == PT_NOTE) { 1405 /* Update note size */ 1406 phdr->p_memsz = elfnotes_orig_sz + vmcoreddsz; 1407 phdr->p_filesz = phdr->p_memsz; 1408 continue; 1409 } 1410 1411 start = rounddown(phdr->p_offset, PAGE_SIZE); 1412 end = roundup(phdr->p_offset + phdr->p_memsz, 1413 PAGE_SIZE); 1414 size = end - start; 1415 phdr->p_offset = vmcore_off + (phdr->p_offset - start); 1416 vmcore_off += size; 1417 } 1418 } else { 1419 Elf32_Ehdr *ehdr = (Elf32_Ehdr *)elfptr; 1420 Elf32_Phdr *phdr = (Elf32_Phdr *)(elfptr + sizeof(Elf32_Ehdr)); 1421 1422 /* Update all program headers */ 1423 for (i = 0; i < ehdr->e_phnum; i++, phdr++) { 1424 if (phdr->p_type == PT_NOTE) { 1425 /* Update note size */ 1426 phdr->p_memsz = elfnotes_orig_sz + vmcoreddsz; 1427 phdr->p_filesz = phdr->p_memsz; 1428 continue; 1429 } 1430 1431 start = rounddown(phdr->p_offset, PAGE_SIZE); 1432 end = roundup(phdr->p_offset + phdr->p_memsz, 1433 PAGE_SIZE); 1434 size = end - start; 1435 phdr->p_offset = vmcore_off + (phdr->p_offset - start); 1436 vmcore_off += size; 1437 } 1438 } 1439 } 1440 1441 /** 1442 * vmcoredd_update_size - Update the total size of the device dumps and update 1443 * Elf header 1444 * @dump_size: Size of the current device dump to be added to total size 1445 * 1446 * Update the total size of all the device dumps and update the Elf program 1447 * headers. Calculate the new offsets for the vmcore list and update the 1448 * total vmcore size. 1449 */ 1450 static void vmcoredd_update_size(size_t dump_size) 1451 { 1452 vmcoredd_orig_sz += dump_size; 1453 elfnotes_sz = roundup(elfnotes_orig_sz, PAGE_SIZE) + vmcoredd_orig_sz; 1454 vmcoredd_update_program_headers(elfcorebuf, elfnotes_sz, 1455 vmcoredd_orig_sz); 1456 1457 /* Update vmcore list offsets */ 1458 set_vmcore_list_offsets(elfcorebuf_sz, elfnotes_sz, &vmcore_list); 1459 1460 vmcore_size = get_vmcore_size(elfcorebuf_sz, elfnotes_sz, 1461 &vmcore_list); 1462 proc_vmcore->size = vmcore_size; 1463 } 1464 1465 /** 1466 * vmcore_add_device_dump - Add a buffer containing device dump to vmcore 1467 * @data: dump info. 1468 * 1469 * Allocate a buffer and invoke the calling driver's dump collect routine. 1470 * Write Elf note at the beginning of the buffer to indicate vmcore device 1471 * dump and add the dump to global list. 1472 */ 1473 int vmcore_add_device_dump(struct vmcoredd_data *data) 1474 { 1475 struct vmcoredd_node *dump; 1476 void *buf = NULL; 1477 size_t data_size; 1478 int ret; 1479 1480 if (vmcoredd_disabled) { 1481 pr_err_once("Device dump is disabled\n"); 1482 return -EINVAL; 1483 } 1484 1485 if (!data || !strlen(data->dump_name) || 1486 !data->vmcoredd_callback || !data->size) 1487 return -EINVAL; 1488 1489 dump = vzalloc(sizeof(*dump)); 1490 if (!dump) { 1491 ret = -ENOMEM; 1492 goto out_err; 1493 } 1494 1495 /* Keep size of the buffer page aligned so that it can be mmaped */ 1496 data_size = roundup(sizeof(struct vmcoredd_header) + data->size, 1497 PAGE_SIZE); 1498 1499 /* Allocate buffer for driver's to write their dumps */ 1500 buf = vmcore_alloc_buf(data_size); 1501 if (!buf) { 1502 ret = -ENOMEM; 1503 goto out_err; 1504 } 1505 1506 vmcoredd_write_header(buf, data, data_size - 1507 sizeof(struct vmcoredd_header)); 1508 1509 /* Invoke the driver's dump collection routing */ 1510 ret = data->vmcoredd_callback(data, buf + 1511 sizeof(struct vmcoredd_header)); 1512 if (ret) 1513 goto out_err; 1514 1515 dump->buf = buf; 1516 dump->size = data_size; 1517 1518 /* Add the dump to driver sysfs list */ 1519 mutex_lock(&vmcoredd_mutex); 1520 list_add_tail(&dump->list, &vmcoredd_list); 1521 mutex_unlock(&vmcoredd_mutex); 1522 1523 vmcoredd_update_size(data_size); 1524 return 0; 1525 1526 out_err: 1527 vfree(buf); 1528 vfree(dump); 1529 1530 return ret; 1531 } 1532 EXPORT_SYMBOL(vmcore_add_device_dump); 1533 #endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */ 1534 1535 /* Free all dumps in vmcore device dump list */ 1536 static void vmcore_free_device_dumps(void) 1537 { 1538 #ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP 1539 mutex_lock(&vmcoredd_mutex); 1540 while (!list_empty(&vmcoredd_list)) { 1541 struct vmcoredd_node *dump; 1542 1543 dump = list_first_entry(&vmcoredd_list, struct vmcoredd_node, 1544 list); 1545 list_del(&dump->list); 1546 vfree(dump->buf); 1547 vfree(dump); 1548 } 1549 mutex_unlock(&vmcoredd_mutex); 1550 #endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */ 1551 } 1552 1553 /* Init function for vmcore module. */ 1554 static int __init vmcore_init(void) 1555 { 1556 int rc = 0; 1557 1558 /* Allow architectures to allocate ELF header in 2nd kernel */ 1559 rc = elfcorehdr_alloc(&elfcorehdr_addr, &elfcorehdr_size); 1560 if (rc) 1561 return rc; 1562 /* 1563 * If elfcorehdr= has been passed in cmdline or created in 2nd kernel, 1564 * then capture the dump. 1565 */ 1566 if (!(is_vmcore_usable())) 1567 return rc; 1568 rc = parse_crash_elf_headers(); 1569 if (rc) { 1570 elfcorehdr_free(elfcorehdr_addr); 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