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