1606 lines · c
1// SPDX-License-Identifier: GPL-2.0-only2/*3 * fs/proc/vmcore.c Interface for accessing the crash4 * dump from the system's previous life.5 * Heavily borrowed from fs/proc/kcore.c6 * Created by: Hariprasad Nellitheertha (hari@in.ibm.com)7 * Copyright (C) IBM Corporation, 2004. All rights reserved8 *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 in34 * vmcore file.35 */36static LIST_HEAD(vmcore_list);37 38/* Stores the pointer to the buffer containing kernel elf core headers. */39static char *elfcorebuf;40static size_t elfcorebuf_sz;41static size_t elfcorebuf_sz_orig;42 43static char *elfnotes_buf;44static size_t elfnotes_sz;45/* Size of all notes minus the device dump notes */46static size_t elfnotes_orig_sz;47 48/* Total size of vmcore file. */49static u64 vmcore_size;50 51static struct proc_dir_entry *proc_vmcore;52 53#ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP54/* Device Dump list and mutex to synchronize access to list */55static LIST_HEAD(vmcoredd_list);56static DEFINE_MUTEX(vmcoredd_mutex);57 58static bool vmcoredd_disabled;59core_param(novmcoredd, vmcoredd_disabled, bool, 0);60#endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */61 62/* Device Dump Size */63static size_t vmcoredd_orig_sz;64 65static DEFINE_SPINLOCK(vmcore_cb_lock);66DEFINE_STATIC_SRCU(vmcore_cb_srcu);67/* List of registered vmcore callbacks. */68static LIST_HEAD(vmcore_cb_list);69/* Whether the vmcore has been opened once. */70static bool vmcore_opened;71 72void 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 is79 * 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}85EXPORT_SYMBOL_GPL(register_vmcore_cb);86 87void 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 is93 * very unusual (e.g., forced driver removal), but we cannot stop94 * 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}102EXPORT_SYMBOL_GPL(unregister_vmcore_cb);103 104static 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 121static 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. */131ssize_t read_from_oldmem(struct iov_iter *iter, size_t count,132 u64 *ppos, bool encrypted)133{134 unsigned long pfn, offset;135 ssize_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 else150 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 else161 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 kernel182 */183int __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 header190 */191void __weak elfcorehdr_free(unsigned long long addr)192{}193 194/*195 * Architectures may override this function to read from ELF header196 */197ssize_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 sections209 */210ssize_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 oldmem223 */224int __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 */235ssize_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_DUMP242static 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 270out_unlock:271 mutex_unlock(&vmcoredd_mutex);272 return ret;273}274 275#ifdef CONFIG_MMU276static 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 307out_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 is315 * returned otherwise number of bytes read are returned.316 */317static 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 the347 * other elf notes may not fill the elf notes buffer348 * completely and we will end up with zero-filled data349 * between the elf notes and the device dumps. Tools will350 * then try to decode this zero-filled data as valid notes351 * and we don't want that. Hence, adding device dumps before352 * the other elf notes ensure that zero-filled data can be353 * avoided.354 */355#ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP356 /* 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 cond_resched();388 }389 390 list_for_each_entry(m, &vmcore_list, list) {391 if (*fpos < m->offset + m->size) {392 tsz = (size_t)min_t(unsigned long long,393 m->offset + m->size - *fpos,394 iov_iter_count(iter));395 start = m->paddr + *fpos - m->offset;396 tmp = read_from_oldmem(iter, tsz, &start,397 cc_platform_has(CC_ATTR_MEM_ENCRYPT));398 if (tmp < 0)399 return tmp;400 *fpos += tsz;401 acc += tsz;402 403 /* leave now if filled buffer already */404 if (!iov_iter_count(iter))405 return acc;406 }407 }408 409 return acc;410}411 412static ssize_t read_vmcore(struct kiocb *iocb, struct iov_iter *iter)413{414 return __read_vmcore(iter, &iocb->ki_pos);415}416 417/*418 * The vmcore fault handler uses the page cache and fills data using the419 * standard __read_vmcore() function.420 *421 * On s390 the fault handler is used for memory regions that can't be mapped422 * directly with remap_pfn_range().423 */424static vm_fault_t mmap_vmcore_fault(struct vm_fault *vmf)425{426#ifdef CONFIG_S390427 struct address_space *mapping = vmf->vma->vm_file->f_mapping;428 pgoff_t index = vmf->pgoff;429 struct iov_iter iter;430 struct kvec kvec;431 struct page *page;432 loff_t offset;433 int rc;434 435 page = find_or_create_page(mapping, index, GFP_KERNEL);436 if (!page)437 return VM_FAULT_OOM;438 if (!PageUptodate(page)) {439 offset = (loff_t) index << PAGE_SHIFT;440 kvec.iov_base = page_address(page);441 kvec.iov_len = PAGE_SIZE;442 iov_iter_kvec(&iter, ITER_DEST, &kvec, 1, PAGE_SIZE);443 444 rc = __read_vmcore(&iter, &offset);445 if (rc < 0) {446 unlock_page(page);447 put_page(page);448 return vmf_error(rc);449 }450 SetPageUptodate(page);451 }452 unlock_page(page);453 vmf->page = page;454 return 0;455#else456 return VM_FAULT_SIGBUS;457#endif458}459 460/**461 * vmcore_alloc_buf - allocate buffer in vmalloc memory462 * @size: size of buffer463 *464 * If CONFIG_MMU is defined, use vmalloc_user() to allow users to mmap465 * the buffer to user-space by means of remap_vmalloc_range().466 *467 * If CONFIG_MMU is not defined, use vzalloc() since mmap_vmcore() is468 * disabled and there's no need to allow users to mmap the buffer.469 */470static inline char *vmcore_alloc_buf(size_t size)471{472#ifdef CONFIG_MMU473 return vmalloc_user(size);474#else475 return vzalloc(size);476#endif477}478 479/*480 * Disable mmap_vmcore() if CONFIG_MMU is not defined. MMU is481 * essential for mmap_vmcore() in order to map physically482 * non-contiguous objects (ELF header, ELF note segment and memory483 * regions in the 1st kernel pointed to by PT_LOAD entries) into484 * virtually contiguous user-space in ELF layout.485 */486#ifdef CONFIG_MMU487 488static const struct vm_operations_struct vmcore_mmap_ops = {489 .fault = mmap_vmcore_fault,490};491 492/*493 * remap_oldmem_pfn_checked - do remap_oldmem_pfn_range replacing all pages494 * reported as not being ram with the zero page.495 *496 * @vma: vm_area_struct describing requested mapping497 * @from: start remapping from498 * @pfn: page frame number to start remapping to499 * @size: remapping size500 * @prot: protection bits501 *502 * Returns zero on success, -EAGAIN on failure.503 */504static int remap_oldmem_pfn_checked(struct vm_area_struct *vma,505 unsigned long from, unsigned long pfn,506 unsigned long size, pgprot_t prot)507{508 unsigned long map_size;509 unsigned long pos_start, pos_end, pos;510 unsigned long zeropage_pfn = my_zero_pfn(0);511 size_t len = 0;512 513 pos_start = pfn;514 pos_end = pfn + (size >> PAGE_SHIFT);515 516 for (pos = pos_start; pos < pos_end; ++pos) {517 if (!pfn_is_ram(pos)) {518 /*519 * We hit a page which is not ram. Remap the continuous520 * region between pos_start and pos-1 and replace521 * the non-ram page at pos with the zero page.522 */523 if (pos > pos_start) {524 /* Remap continuous region */525 map_size = (pos - pos_start) << PAGE_SHIFT;526 if (remap_oldmem_pfn_range(vma, from + len,527 pos_start, map_size,528 prot))529 goto fail;530 len += map_size;531 }532 /* Remap the zero page */533 if (remap_oldmem_pfn_range(vma, from + len,534 zeropage_pfn,535 PAGE_SIZE, prot))536 goto fail;537 len += PAGE_SIZE;538 pos_start = pos + 1;539 }540 }541 if (pos > pos_start) {542 /* Remap the rest */543 map_size = (pos - pos_start) << PAGE_SHIFT;544 if (remap_oldmem_pfn_range(vma, from + len, pos_start,545 map_size, prot))546 goto fail;547 }548 return 0;549fail:550 do_munmap(vma->vm_mm, from, len, NULL);551 return -EAGAIN;552}553 554static int vmcore_remap_oldmem_pfn(struct vm_area_struct *vma,555 unsigned long from, unsigned long pfn,556 unsigned long size, pgprot_t prot)557{558 int ret, idx;559 560 /*561 * Check if a callback was registered to avoid looping over all562 * pages without a reason.563 */564 idx = srcu_read_lock(&vmcore_cb_srcu);565 if (!list_empty(&vmcore_cb_list))566 ret = remap_oldmem_pfn_checked(vma, from, pfn, size, prot);567 else568 ret = remap_oldmem_pfn_range(vma, from, pfn, size, prot);569 srcu_read_unlock(&vmcore_cb_srcu, idx);570 return ret;571}572 573static int mmap_vmcore(struct file *file, struct vm_area_struct *vma)574{575 size_t size = vma->vm_end - vma->vm_start;576 u64 start, end, len, tsz;577 struct vmcore *m;578 579 start = (u64)vma->vm_pgoff << PAGE_SHIFT;580 end = start + size;581 582 if (size > vmcore_size || end > vmcore_size)583 return -EINVAL;584 585 if (vma->vm_flags & (VM_WRITE | VM_EXEC))586 return -EPERM;587 588 vm_flags_mod(vma, VM_MIXEDMAP, VM_MAYWRITE | VM_MAYEXEC);589 vma->vm_ops = &vmcore_mmap_ops;590 591 len = 0;592 593 if (start < elfcorebuf_sz) {594 u64 pfn;595 596 tsz = min(elfcorebuf_sz - (size_t)start, size);597 pfn = __pa(elfcorebuf + start) >> PAGE_SHIFT;598 if (remap_pfn_range(vma, vma->vm_start, pfn, tsz,599 vma->vm_page_prot))600 return -EAGAIN;601 size -= tsz;602 start += tsz;603 len += tsz;604 605 if (size == 0)606 return 0;607 }608 609 if (start < elfcorebuf_sz + elfnotes_sz) {610 void *kaddr;611 612 /* We add device dumps before other elf notes because the613 * other elf notes may not fill the elf notes buffer614 * completely and we will end up with zero-filled data615 * between the elf notes and the device dumps. Tools will616 * then try to decode this zero-filled data as valid notes617 * and we don't want that. Hence, adding device dumps before618 * the other elf notes ensure that zero-filled data can be619 * avoided. This also ensures that the device dumps and620 * other elf notes can be properly mmaped at page aligned621 * address.622 */623#ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP624 /* Read device dumps */625 if (start < elfcorebuf_sz + vmcoredd_orig_sz) {626 u64 start_off;627 628 tsz = min(elfcorebuf_sz + vmcoredd_orig_sz -629 (size_t)start, size);630 start_off = start - elfcorebuf_sz;631 if (vmcoredd_mmap_dumps(vma, vma->vm_start + len,632 start_off, tsz))633 goto fail;634 635 size -= tsz;636 start += tsz;637 len += tsz;638 639 /* leave now if filled buffer already */640 if (!size)641 return 0;642 }643#endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */644 645 /* Read remaining elf notes */646 tsz = min(elfcorebuf_sz + elfnotes_sz - (size_t)start, size);647 kaddr = elfnotes_buf + start - elfcorebuf_sz - vmcoredd_orig_sz;648 if (remap_vmalloc_range_partial(vma, vma->vm_start + len,649 kaddr, 0, tsz))650 goto fail;651 652 size -= tsz;653 start += tsz;654 len += tsz;655 656 if (size == 0)657 return 0;658 }659 660 list_for_each_entry(m, &vmcore_list, list) {661 if (start < m->offset + m->size) {662 u64 paddr = 0;663 664 tsz = (size_t)min_t(unsigned long long,665 m->offset + m->size - start, size);666 paddr = m->paddr + start - m->offset;667 if (vmcore_remap_oldmem_pfn(vma, vma->vm_start + len,668 paddr >> PAGE_SHIFT, tsz,669 vma->vm_page_prot))670 goto fail;671 size -= tsz;672 start += tsz;673 len += tsz;674 675 if (size == 0)676 return 0;677 }678 }679 680 return 0;681fail:682 do_munmap(vma->vm_mm, vma->vm_start, len, NULL);683 return -EAGAIN;684}685#else686static int mmap_vmcore(struct file *file, struct vm_area_struct *vma)687{688 return -ENOSYS;689}690#endif691 692static const struct proc_ops vmcore_proc_ops = {693 .proc_open = open_vmcore,694 .proc_read_iter = read_vmcore,695 .proc_lseek = default_llseek,696 .proc_mmap = mmap_vmcore,697};698 699static struct vmcore* __init get_new_element(void)700{701 return kzalloc(sizeof(struct vmcore), GFP_KERNEL);702}703 704static u64 get_vmcore_size(size_t elfsz, size_t elfnotesegsz,705 struct list_head *vc_list)706{707 u64 size;708 struct vmcore *m;709 710 size = elfsz + elfnotesegsz;711 list_for_each_entry(m, vc_list, list) {712 size += m->size;713 }714 return size;715}716 717/**718 * update_note_header_size_elf64 - update p_memsz member of each PT_NOTE entry719 *720 * @ehdr_ptr: ELF header721 *722 * This function updates p_memsz member of each PT_NOTE entry in the723 * program header table pointed to by @ehdr_ptr to real size of ELF724 * note segment.725 */726static int __init update_note_header_size_elf64(const Elf64_Ehdr *ehdr_ptr)727{728 int i, rc=0;729 Elf64_Phdr *phdr_ptr;730 Elf64_Nhdr *nhdr_ptr;731 732 phdr_ptr = (Elf64_Phdr *)(ehdr_ptr + 1);733 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {734 void *notes_section;735 u64 offset, max_sz, sz, real_sz = 0;736 if (phdr_ptr->p_type != PT_NOTE)737 continue;738 max_sz = phdr_ptr->p_memsz;739 offset = phdr_ptr->p_offset;740 notes_section = kmalloc(max_sz, GFP_KERNEL);741 if (!notes_section)742 return -ENOMEM;743 rc = elfcorehdr_read_notes(notes_section, max_sz, &offset);744 if (rc < 0) {745 kfree(notes_section);746 return rc;747 }748 nhdr_ptr = notes_section;749 while (nhdr_ptr->n_namesz != 0) {750 sz = sizeof(Elf64_Nhdr) +751 (((u64)nhdr_ptr->n_namesz + 3) & ~3) +752 (((u64)nhdr_ptr->n_descsz + 3) & ~3);753 if ((real_sz + sz) > max_sz) {754 pr_warn("Warning: Exceeded p_memsz, dropping PT_NOTE entry n_namesz=0x%x, n_descsz=0x%x\n",755 nhdr_ptr->n_namesz, nhdr_ptr->n_descsz);756 break;757 }758 real_sz += sz;759 nhdr_ptr = (Elf64_Nhdr*)((char*)nhdr_ptr + sz);760 }761 kfree(notes_section);762 phdr_ptr->p_memsz = real_sz;763 if (real_sz == 0) {764 pr_warn("Warning: Zero PT_NOTE entries found\n");765 }766 }767 768 return 0;769}770 771/**772 * get_note_number_and_size_elf64 - get the number of PT_NOTE program773 * headers and sum of real size of their ELF note segment headers and774 * data.775 *776 * @ehdr_ptr: ELF header777 * @nr_ptnote: buffer for the number of PT_NOTE program headers778 * @sz_ptnote: buffer for size of unique PT_NOTE program header779 *780 * This function is used to merge multiple PT_NOTE program headers781 * into a unique single one. The resulting unique entry will have782 * @sz_ptnote in its phdr->p_mem.783 *784 * It is assumed that program headers with PT_NOTE type pointed to by785 * @ehdr_ptr has already been updated by update_note_header_size_elf64786 * and each of PT_NOTE program headers has actual ELF note segment787 * size in its p_memsz member.788 */789static int __init get_note_number_and_size_elf64(const Elf64_Ehdr *ehdr_ptr,790 int *nr_ptnote, u64 *sz_ptnote)791{792 int i;793 Elf64_Phdr *phdr_ptr;794 795 *nr_ptnote = *sz_ptnote = 0;796 797 phdr_ptr = (Elf64_Phdr *)(ehdr_ptr + 1);798 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {799 if (phdr_ptr->p_type != PT_NOTE)800 continue;801 *nr_ptnote += 1;802 *sz_ptnote += phdr_ptr->p_memsz;803 }804 805 return 0;806}807 808/**809 * copy_notes_elf64 - copy ELF note segments in a given buffer810 *811 * @ehdr_ptr: ELF header812 * @notes_buf: buffer into which ELF note segments are copied813 *814 * This function is used to copy ELF note segment in the 1st kernel815 * into the buffer @notes_buf in the 2nd kernel. It is assumed that816 * size of the buffer @notes_buf is equal to or larger than sum of the817 * real ELF note segment headers and data.818 *819 * It is assumed that program headers with PT_NOTE type pointed to by820 * @ehdr_ptr has already been updated by update_note_header_size_elf64821 * and each of PT_NOTE program headers has actual ELF note segment822 * size in its p_memsz member.823 */824static int __init copy_notes_elf64(const Elf64_Ehdr *ehdr_ptr, char *notes_buf)825{826 int i, rc=0;827 Elf64_Phdr *phdr_ptr;828 829 phdr_ptr = (Elf64_Phdr*)(ehdr_ptr + 1);830 831 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {832 u64 offset;833 if (phdr_ptr->p_type != PT_NOTE)834 continue;835 offset = phdr_ptr->p_offset;836 rc = elfcorehdr_read_notes(notes_buf, phdr_ptr->p_memsz,837 &offset);838 if (rc < 0)839 return rc;840 notes_buf += phdr_ptr->p_memsz;841 }842 843 return 0;844}845 846/* Merges all the PT_NOTE headers into one. */847static int __init merge_note_headers_elf64(char *elfptr, size_t *elfsz,848 char **notes_buf, size_t *notes_sz)849{850 int i, nr_ptnote=0, rc=0;851 char *tmp;852 Elf64_Ehdr *ehdr_ptr;853 Elf64_Phdr phdr;854 u64 phdr_sz = 0, note_off;855 856 ehdr_ptr = (Elf64_Ehdr *)elfptr;857 858 rc = update_note_header_size_elf64(ehdr_ptr);859 if (rc < 0)860 return rc;861 862 rc = get_note_number_and_size_elf64(ehdr_ptr, &nr_ptnote, &phdr_sz);863 if (rc < 0)864 return rc;865 866 *notes_sz = roundup(phdr_sz, PAGE_SIZE);867 *notes_buf = vmcore_alloc_buf(*notes_sz);868 if (!*notes_buf)869 return -ENOMEM;870 871 rc = copy_notes_elf64(ehdr_ptr, *notes_buf);872 if (rc < 0)873 return rc;874 875 /* Prepare merged PT_NOTE program header. */876 phdr.p_type = PT_NOTE;877 phdr.p_flags = 0;878 note_off = sizeof(Elf64_Ehdr) +879 (ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf64_Phdr);880 phdr.p_offset = roundup(note_off, PAGE_SIZE);881 phdr.p_vaddr = phdr.p_paddr = 0;882 phdr.p_filesz = phdr.p_memsz = phdr_sz;883 phdr.p_align = 4;884 885 /* Add merged PT_NOTE program header*/886 tmp = elfptr + sizeof(Elf64_Ehdr);887 memcpy(tmp, &phdr, sizeof(phdr));888 tmp += sizeof(phdr);889 890 /* Remove unwanted PT_NOTE program headers. */891 i = (nr_ptnote - 1) * sizeof(Elf64_Phdr);892 *elfsz = *elfsz - i;893 memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf64_Ehdr)-sizeof(Elf64_Phdr)));894 memset(elfptr + *elfsz, 0, i);895 *elfsz = roundup(*elfsz, PAGE_SIZE);896 897 /* Modify e_phnum to reflect merged headers. */898 ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1;899 900 /* Store the size of all notes. We need this to update the note901 * header when the device dumps will be added.902 */903 elfnotes_orig_sz = phdr.p_memsz;904 905 return 0;906}907 908/**909 * update_note_header_size_elf32 - update p_memsz member of each PT_NOTE entry910 *911 * @ehdr_ptr: ELF header912 *913 * This function updates p_memsz member of each PT_NOTE entry in the914 * program header table pointed to by @ehdr_ptr to real size of ELF915 * note segment.916 */917static int __init update_note_header_size_elf32(const Elf32_Ehdr *ehdr_ptr)918{919 int i, rc=0;920 Elf32_Phdr *phdr_ptr;921 Elf32_Nhdr *nhdr_ptr;922 923 phdr_ptr = (Elf32_Phdr *)(ehdr_ptr + 1);924 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {925 void *notes_section;926 u64 offset, max_sz, sz, real_sz = 0;927 if (phdr_ptr->p_type != PT_NOTE)928 continue;929 max_sz = phdr_ptr->p_memsz;930 offset = phdr_ptr->p_offset;931 notes_section = kmalloc(max_sz, GFP_KERNEL);932 if (!notes_section)933 return -ENOMEM;934 rc = elfcorehdr_read_notes(notes_section, max_sz, &offset);935 if (rc < 0) {936 kfree(notes_section);937 return rc;938 }939 nhdr_ptr = notes_section;940 while (nhdr_ptr->n_namesz != 0) {941 sz = sizeof(Elf32_Nhdr) +942 (((u64)nhdr_ptr->n_namesz + 3) & ~3) +943 (((u64)nhdr_ptr->n_descsz + 3) & ~3);944 if ((real_sz + sz) > max_sz) {945 pr_warn("Warning: Exceeded p_memsz, dropping PT_NOTE entry n_namesz=0x%x, n_descsz=0x%x\n",946 nhdr_ptr->n_namesz, nhdr_ptr->n_descsz);947 break;948 }949 real_sz += sz;950 nhdr_ptr = (Elf32_Nhdr*)((char*)nhdr_ptr + sz);951 }952 kfree(notes_section);953 phdr_ptr->p_memsz = real_sz;954 if (real_sz == 0) {955 pr_warn("Warning: Zero PT_NOTE entries found\n");956 }957 }958 959 return 0;960}961 962/**963 * get_note_number_and_size_elf32 - get the number of PT_NOTE program964 * headers and sum of real size of their ELF note segment headers and965 * data.966 *967 * @ehdr_ptr: ELF header968 * @nr_ptnote: buffer for the number of PT_NOTE program headers969 * @sz_ptnote: buffer for size of unique PT_NOTE program header970 *971 * This function is used to merge multiple PT_NOTE program headers972 * into a unique single one. The resulting unique entry will have973 * @sz_ptnote in its phdr->p_mem.974 *975 * It is assumed that program headers with PT_NOTE type pointed to by976 * @ehdr_ptr has already been updated by update_note_header_size_elf32977 * and each of PT_NOTE program headers has actual ELF note segment978 * size in its p_memsz member.979 */980static int __init get_note_number_and_size_elf32(const Elf32_Ehdr *ehdr_ptr,981 int *nr_ptnote, u64 *sz_ptnote)982{983 int i;984 Elf32_Phdr *phdr_ptr;985 986 *nr_ptnote = *sz_ptnote = 0;987 988 phdr_ptr = (Elf32_Phdr *)(ehdr_ptr + 1);989 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {990 if (phdr_ptr->p_type != PT_NOTE)991 continue;992 *nr_ptnote += 1;993 *sz_ptnote += phdr_ptr->p_memsz;994 }995 996 return 0;997}998 999/**1000 * copy_notes_elf32 - copy ELF note segments in a given buffer1001 *1002 * @ehdr_ptr: ELF header1003 * @notes_buf: buffer into which ELF note segments are copied1004 *1005 * This function is used to copy ELF note segment in the 1st kernel1006 * into the buffer @notes_buf in the 2nd kernel. It is assumed that1007 * size of the buffer @notes_buf is equal to or larger than sum of the1008 * real ELF note segment headers and data.1009 *1010 * It is assumed that program headers with PT_NOTE type pointed to by1011 * @ehdr_ptr has already been updated by update_note_header_size_elf321012 * and each of PT_NOTE program headers has actual ELF note segment1013 * size in its p_memsz member.1014 */1015static int __init copy_notes_elf32(const Elf32_Ehdr *ehdr_ptr, char *notes_buf)1016{1017 int i, rc=0;1018 Elf32_Phdr *phdr_ptr;1019 1020 phdr_ptr = (Elf32_Phdr*)(ehdr_ptr + 1);1021 1022 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {1023 u64 offset;1024 if (phdr_ptr->p_type != PT_NOTE)1025 continue;1026 offset = phdr_ptr->p_offset;1027 rc = elfcorehdr_read_notes(notes_buf, phdr_ptr->p_memsz,1028 &offset);1029 if (rc < 0)1030 return rc;1031 notes_buf += phdr_ptr->p_memsz;1032 }1033 1034 return 0;1035}1036 1037/* Merges all the PT_NOTE headers into one. */1038static int __init merge_note_headers_elf32(char *elfptr, size_t *elfsz,1039 char **notes_buf, size_t *notes_sz)1040{1041 int i, nr_ptnote=0, rc=0;1042 char *tmp;1043 Elf32_Ehdr *ehdr_ptr;1044 Elf32_Phdr phdr;1045 u64 phdr_sz = 0, note_off;1046 1047 ehdr_ptr = (Elf32_Ehdr *)elfptr;1048 1049 rc = update_note_header_size_elf32(ehdr_ptr);1050 if (rc < 0)1051 return rc;1052 1053 rc = get_note_number_and_size_elf32(ehdr_ptr, &nr_ptnote, &phdr_sz);1054 if (rc < 0)1055 return rc;1056 1057 *notes_sz = roundup(phdr_sz, PAGE_SIZE);1058 *notes_buf = vmcore_alloc_buf(*notes_sz);1059 if (!*notes_buf)1060 return -ENOMEM;1061 1062 rc = copy_notes_elf32(ehdr_ptr, *notes_buf);1063 if (rc < 0)1064 return rc;1065 1066 /* Prepare merged PT_NOTE program header. */1067 phdr.p_type = PT_NOTE;1068 phdr.p_flags = 0;1069 note_off = sizeof(Elf32_Ehdr) +1070 (ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf32_Phdr);1071 phdr.p_offset = roundup(note_off, PAGE_SIZE);1072 phdr.p_vaddr = phdr.p_paddr = 0;1073 phdr.p_filesz = phdr.p_memsz = phdr_sz;1074 phdr.p_align = 4;1075 1076 /* Add merged PT_NOTE program header*/1077 tmp = elfptr + sizeof(Elf32_Ehdr);1078 memcpy(tmp, &phdr, sizeof(phdr));1079 tmp += sizeof(phdr);1080 1081 /* Remove unwanted PT_NOTE program headers. */1082 i = (nr_ptnote - 1) * sizeof(Elf32_Phdr);1083 *elfsz = *elfsz - i;1084 memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf32_Ehdr)-sizeof(Elf32_Phdr)));1085 memset(elfptr + *elfsz, 0, i);1086 *elfsz = roundup(*elfsz, PAGE_SIZE);1087 1088 /* Modify e_phnum to reflect merged headers. */1089 ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1;1090 1091 /* Store the size of all notes. We need this to update the note1092 * header when the device dumps will be added.1093 */1094 elfnotes_orig_sz = phdr.p_memsz;1095 1096 return 0;1097}1098 1099/* Add memory chunks represented by program headers to vmcore list. Also update1100 * the new offset fields of exported program headers. */1101static int __init process_ptload_program_headers_elf64(char *elfptr,1102 size_t elfsz,1103 size_t elfnotes_sz,1104 struct list_head *vc_list)1105{1106 int i;1107 Elf64_Ehdr *ehdr_ptr;1108 Elf64_Phdr *phdr_ptr;1109 loff_t vmcore_off;1110 struct vmcore *new;1111 1112 ehdr_ptr = (Elf64_Ehdr *)elfptr;1113 phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr)); /* PT_NOTE hdr */1114 1115 /* Skip ELF header, program headers and ELF note segment. */1116 vmcore_off = elfsz + elfnotes_sz;1117 1118 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {1119 u64 paddr, start, end, size;1120 1121 if (phdr_ptr->p_type != PT_LOAD)1122 continue;1123 1124 paddr = phdr_ptr->p_offset;1125 start = rounddown(paddr, PAGE_SIZE);1126 end = roundup(paddr + phdr_ptr->p_memsz, PAGE_SIZE);1127 size = end - start;1128 1129 /* Add this contiguous chunk of memory to vmcore list.*/1130 new = get_new_element();1131 if (!new)1132 return -ENOMEM;1133 new->paddr = start;1134 new->size = size;1135 list_add_tail(&new->list, vc_list);1136 1137 /* Update the program header offset. */1138 phdr_ptr->p_offset = vmcore_off + (paddr - start);1139 vmcore_off = vmcore_off + size;1140 }1141 return 0;1142}1143 1144static int __init process_ptload_program_headers_elf32(char *elfptr,1145 size_t elfsz,1146 size_t elfnotes_sz,1147 struct list_head *vc_list)1148{1149 int i;1150 Elf32_Ehdr *ehdr_ptr;1151 Elf32_Phdr *phdr_ptr;1152 loff_t vmcore_off;1153 struct vmcore *new;1154 1155 ehdr_ptr = (Elf32_Ehdr *)elfptr;1156 phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr)); /* PT_NOTE hdr */1157 1158 /* Skip ELF header, program headers and ELF note segment. */1159 vmcore_off = elfsz + elfnotes_sz;1160 1161 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {1162 u64 paddr, start, end, size;1163 1164 if (phdr_ptr->p_type != PT_LOAD)1165 continue;1166 1167 paddr = phdr_ptr->p_offset;1168 start = rounddown(paddr, PAGE_SIZE);1169 end = roundup(paddr + phdr_ptr->p_memsz, PAGE_SIZE);1170 size = end - start;1171 1172 /* Add this contiguous chunk of memory to vmcore list.*/1173 new = get_new_element();1174 if (!new)1175 return -ENOMEM;1176 new->paddr = start;1177 new->size = size;1178 list_add_tail(&new->list, vc_list);1179 1180 /* Update the program header offset */1181 phdr_ptr->p_offset = vmcore_off + (paddr - start);1182 vmcore_off = vmcore_off + size;1183 }1184 return 0;1185}1186 1187/* Sets offset fields of vmcore elements. */1188static void set_vmcore_list_offsets(size_t elfsz, size_t elfnotes_sz,1189 struct list_head *vc_list)1190{1191 loff_t vmcore_off;1192 struct vmcore *m;1193 1194 /* Skip ELF header, program headers and ELF note segment. */1195 vmcore_off = elfsz + elfnotes_sz;1196 1197 list_for_each_entry(m, vc_list, list) {1198 m->offset = vmcore_off;1199 vmcore_off += m->size;1200 }1201}1202 1203static void free_elfcorebuf(void)1204{1205 free_pages((unsigned long)elfcorebuf, get_order(elfcorebuf_sz_orig));1206 elfcorebuf = NULL;1207 vfree(elfnotes_buf);1208 elfnotes_buf = NULL;1209}1210 1211static int __init parse_crash_elf64_headers(void)1212{1213 int rc=0;1214 Elf64_Ehdr ehdr;1215 u64 addr;1216 1217 addr = elfcorehdr_addr;1218 1219 /* Read ELF header */1220 rc = elfcorehdr_read((char *)&ehdr, sizeof(Elf64_Ehdr), &addr);1221 if (rc < 0)1222 return rc;1223 1224 /* Do some basic Verification. */1225 if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0 ||1226 (ehdr.e_type != ET_CORE) ||1227 !vmcore_elf64_check_arch(&ehdr) ||1228 ehdr.e_ident[EI_CLASS] != ELFCLASS64 ||1229 ehdr.e_ident[EI_VERSION] != EV_CURRENT ||1230 ehdr.e_version != EV_CURRENT ||1231 ehdr.e_ehsize != sizeof(Elf64_Ehdr) ||1232 ehdr.e_phentsize != sizeof(Elf64_Phdr) ||1233 ehdr.e_phnum == 0) {1234 pr_warn("Warning: Core image elf header is not sane\n");1235 return -EINVAL;1236 }1237 1238 /* Read in all elf headers. */1239 elfcorebuf_sz_orig = sizeof(Elf64_Ehdr) +1240 ehdr.e_phnum * sizeof(Elf64_Phdr);1241 elfcorebuf_sz = elfcorebuf_sz_orig;1242 elfcorebuf = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,1243 get_order(elfcorebuf_sz_orig));1244 if (!elfcorebuf)1245 return -ENOMEM;1246 addr = elfcorehdr_addr;1247 rc = elfcorehdr_read(elfcorebuf, elfcorebuf_sz_orig, &addr);1248 if (rc < 0)1249 goto fail;1250 1251 /* Merge all PT_NOTE headers into one. */1252 rc = merge_note_headers_elf64(elfcorebuf, &elfcorebuf_sz,1253 &elfnotes_buf, &elfnotes_sz);1254 if (rc)1255 goto fail;1256 rc = process_ptload_program_headers_elf64(elfcorebuf, elfcorebuf_sz,1257 elfnotes_sz, &vmcore_list);1258 if (rc)1259 goto fail;1260 set_vmcore_list_offsets(elfcorebuf_sz, elfnotes_sz, &vmcore_list);1261 return 0;1262fail:1263 free_elfcorebuf();1264 return rc;1265}1266 1267static int __init parse_crash_elf32_headers(void)1268{1269 int rc=0;1270 Elf32_Ehdr ehdr;1271 u64 addr;1272 1273 addr = elfcorehdr_addr;1274 1275 /* Read ELF header */1276 rc = elfcorehdr_read((char *)&ehdr, sizeof(Elf32_Ehdr), &addr);1277 if (rc < 0)1278 return rc;1279 1280 /* Do some basic Verification. */1281 if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0 ||1282 (ehdr.e_type != ET_CORE) ||1283 !vmcore_elf32_check_arch(&ehdr) ||1284 ehdr.e_ident[EI_CLASS] != ELFCLASS32||1285 ehdr.e_ident[EI_VERSION] != EV_CURRENT ||1286 ehdr.e_version != EV_CURRENT ||1287 ehdr.e_ehsize != sizeof(Elf32_Ehdr) ||1288 ehdr.e_phentsize != sizeof(Elf32_Phdr) ||1289 ehdr.e_phnum == 0) {1290 pr_warn("Warning: Core image elf header is not sane\n");1291 return -EINVAL;1292 }1293 1294 /* Read in all elf headers. */1295 elfcorebuf_sz_orig = sizeof(Elf32_Ehdr) + ehdr.e_phnum * sizeof(Elf32_Phdr);1296 elfcorebuf_sz = elfcorebuf_sz_orig;1297 elfcorebuf = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,1298 get_order(elfcorebuf_sz_orig));1299 if (!elfcorebuf)1300 return -ENOMEM;1301 addr = elfcorehdr_addr;1302 rc = elfcorehdr_read(elfcorebuf, elfcorebuf_sz_orig, &addr);1303 if (rc < 0)1304 goto fail;1305 1306 /* Merge all PT_NOTE headers into one. */1307 rc = merge_note_headers_elf32(elfcorebuf, &elfcorebuf_sz,1308 &elfnotes_buf, &elfnotes_sz);1309 if (rc)1310 goto fail;1311 rc = process_ptload_program_headers_elf32(elfcorebuf, elfcorebuf_sz,1312 elfnotes_sz, &vmcore_list);1313 if (rc)1314 goto fail;1315 set_vmcore_list_offsets(elfcorebuf_sz, elfnotes_sz, &vmcore_list);1316 return 0;1317fail:1318 free_elfcorebuf();1319 return rc;1320}1321 1322static int __init parse_crash_elf_headers(void)1323{1324 unsigned char e_ident[EI_NIDENT];1325 u64 addr;1326 int rc=0;1327 1328 addr = elfcorehdr_addr;1329 rc = elfcorehdr_read(e_ident, EI_NIDENT, &addr);1330 if (rc < 0)1331 return rc;1332 if (memcmp(e_ident, ELFMAG, SELFMAG) != 0) {1333 pr_warn("Warning: Core image elf header not found\n");1334 return -EINVAL;1335 }1336 1337 if (e_ident[EI_CLASS] == ELFCLASS64) {1338 rc = parse_crash_elf64_headers();1339 if (rc)1340 return rc;1341 } else if (e_ident[EI_CLASS] == ELFCLASS32) {1342 rc = parse_crash_elf32_headers();1343 if (rc)1344 return rc;1345 } else {1346 pr_warn("Warning: Core image elf header is not sane\n");1347 return -EINVAL;1348 }1349 1350 /* Determine vmcore size. */1351 vmcore_size = get_vmcore_size(elfcorebuf_sz, elfnotes_sz,1352 &vmcore_list);1353 1354 return 0;1355}1356 1357#ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP1358/**1359 * vmcoredd_write_header - Write vmcore device dump header at the1360 * beginning of the dump's buffer.1361 * @buf: Output buffer where the note is written1362 * @data: Dump info1363 * @size: Size of the dump1364 *1365 * Fills beginning of the dump's buffer with vmcore device dump header.1366 */1367static void vmcoredd_write_header(void *buf, struct vmcoredd_data *data,1368 u32 size)1369{1370 struct vmcoredd_header *vdd_hdr = (struct vmcoredd_header *)buf;1371 1372 vdd_hdr->n_namesz = sizeof(vdd_hdr->name);1373 vdd_hdr->n_descsz = size + sizeof(vdd_hdr->dump_name);1374 vdd_hdr->n_type = NT_VMCOREDD;1375 1376 strscpy_pad(vdd_hdr->name, VMCOREDD_NOTE_NAME);1377 strscpy_pad(vdd_hdr->dump_name, data->dump_name);1378}1379 1380/**1381 * vmcoredd_update_program_headers - Update all ELF program headers1382 * @elfptr: Pointer to elf header1383 * @elfnotesz: Size of elf notes aligned to page size1384 * @vmcoreddsz: Size of device dumps to be added to elf note header1385 *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 */1389static 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 update1444 * ELF header1445 * @dump_size: Size of the current device dump to be added to total size1446 *1447 * Update the total size of all the device dumps and update the ELF program1448 * headers. Calculate the new offsets for the vmcore list and update the1449 * total vmcore size.1450 */1451static 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 vmcore1468 * @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 device1472 * dump and add the dump to global list.1473 */1474int 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 1527out_err:1528 vfree(buf);1529 vfree(dump);1530 1531 return ret;1532}1533EXPORT_SYMBOL(vmcore_add_device_dump);1534#endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */1535 1536/* Free all dumps in vmcore device dump list */1537static void vmcore_free_device_dumps(void)1538{1539#ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP1540 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. */1555static 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 elfcorehdr_free(elfcorehdr_addr);1572 pr_warn("Kdump: vmcore not initialized\n");1573 return rc;1574 }1575 elfcorehdr_free(elfcorehdr_addr);1576 elfcorehdr_addr = ELFCORE_ADDR_ERR;1577 1578 proc_vmcore = proc_create("vmcore", S_IRUSR, NULL, &vmcore_proc_ops);1579 if (proc_vmcore)1580 proc_vmcore->size = vmcore_size;1581 return 0;1582}1583fs_initcall(vmcore_init);1584 1585/* Cleanup function for vmcore module. */1586void vmcore_cleanup(void)1587{1588 if (proc_vmcore) {1589 proc_remove(proc_vmcore);1590 proc_vmcore = NULL;1591 }1592 1593 /* clear the vmcore list. */1594 while (!list_empty(&vmcore_list)) {1595 struct vmcore *m;1596 1597 m = list_first_entry(&vmcore_list, struct vmcore, list);1598 list_del(&m->list);1599 kfree(m);1600 }1601 free_elfcorebuf();1602 1603 /* clear vmcore device dump list */1604 vmcore_free_device_dumps();1605}1606