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linux-sg2042/fs/proc/vmcore.c

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// SPDX-License-Identifier: GPL-2.0-only
/*
* fs/proc/vmcore.c Interface for accessing the crash
* dump from the system's previous life.
* Heavily borrowed from fs/proc/kcore.c
* Created by: Hariprasad Nellitheertha (hari@in.ibm.com)
* Copyright (C) IBM Corporation, 2004. All rights reserved
*
*/
#include <linux/mm.h>
#include <linux/kcore.h>
#include <linux/user.h>
#include <linux/elf.h>
#include <linux/elfcore.h>
#include <linux/export.h>
#include <linux/slab.h>
#include <linux/highmem.h>
#include <linux/printk.h>
#include <linux/memblock.h>
#include <linux/init.h>
#include <linux/crash_dump.h>
#include <linux/list.h>
#include <linux/moduleparam.h>
#include <linux/mutex.h>
#include <linux/vmalloc.h>
#include <linux/pagemap.h>
#include <linux/uaccess.h>
#include <linux/mem_encrypt.h>
#include <asm/pgtable.h>
#include <asm/io.h>
#include "internal.h"
/* List representing chunks of contiguous memory areas and their offsets in
* vmcore file.
*/
static LIST_HEAD(vmcore_list);
/* Stores the pointer to the buffer containing kernel elf core headers. */
static char *elfcorebuf;
static size_t elfcorebuf_sz;
static size_t elfcorebuf_sz_orig;
static char *elfnotes_buf;
static size_t elfnotes_sz;
/* Size of all notes minus the device dump notes */
static size_t elfnotes_orig_sz;
/* Total size of vmcore file. */
static u64 vmcore_size;
static struct proc_dir_entry *proc_vmcore;
#ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP
/* Device Dump list and mutex to synchronize access to list */
static LIST_HEAD(vmcoredd_list);
static DEFINE_MUTEX(vmcoredd_mutex);
static bool vmcoredd_disabled;
core_param(novmcoredd, vmcoredd_disabled, bool, 0);
#endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */
/* Device Dump Size */
static size_t vmcoredd_orig_sz;
/*
* Returns > 0 for RAM pages, 0 for non-RAM pages, < 0 on error
* The called function has to take care of module refcounting.
*/
static int (*oldmem_pfn_is_ram)(unsigned long pfn);
int register_oldmem_pfn_is_ram(int (*fn)(unsigned long pfn))
{
if (oldmem_pfn_is_ram)
return -EBUSY;
oldmem_pfn_is_ram = fn;
return 0;
}
EXPORT_SYMBOL_GPL(register_oldmem_pfn_is_ram);
void unregister_oldmem_pfn_is_ram(void)
{
oldmem_pfn_is_ram = NULL;
wmb();
}
EXPORT_SYMBOL_GPL(unregister_oldmem_pfn_is_ram);
static int pfn_is_ram(unsigned long pfn)
{
int (*fn)(unsigned long pfn);
/* pfn is ram unless fn() checks pagetype */
int ret = 1;
/*
* Ask hypervisor if the pfn is really ram.
* A ballooned page contains no data and reading from such a page
* will cause high load in the hypervisor.
*/
fn = oldmem_pfn_is_ram;
if (fn)
ret = fn(pfn);
return ret;
}
/* Reads a page from the oldmem device from given offset. */
ssize_t read_from_oldmem(char *buf, size_t count,
u64 *ppos, int userbuf,
bool encrypted)
{
unsigned long pfn, offset;
size_t nr_bytes;
ssize_t read = 0, tmp;
if (!count)
return 0;
offset = (unsigned long)(*ppos % PAGE_SIZE);
pfn = (unsigned long)(*ppos / PAGE_SIZE);
do {
if (count > (PAGE_SIZE - offset))
nr_bytes = PAGE_SIZE - offset;
else
nr_bytes = count;
/* If pfn is not ram, return zeros for sparse dump files */
if (pfn_is_ram(pfn) == 0)
memset(buf, 0, nr_bytes);
else {
if (encrypted)
tmp = copy_oldmem_page_encrypted(pfn, buf,
nr_bytes,
offset,
userbuf);
else
tmp = copy_oldmem_page(pfn, buf, nr_bytes,
offset, userbuf);
if (tmp < 0)
return tmp;
}
*ppos += nr_bytes;
count -= nr_bytes;
buf += nr_bytes;
read += nr_bytes;
++pfn;
offset = 0;
} while (count);
return read;
}
/*
* Architectures may override this function to allocate ELF header in 2nd kernel
*/
int __weak elfcorehdr_alloc(unsigned long long *addr, unsigned long long *size)
{
return 0;
}
/*
* Architectures may override this function to free header
*/
void __weak elfcorehdr_free(unsigned long long addr)
{}
/*
* Architectures may override this function to read from ELF header
*/
ssize_t __weak elfcorehdr_read(char *buf, size_t count, u64 *ppos)
{
return read_from_oldmem(buf, count, ppos, 0, false);
}
/*
* Architectures may override this function to read from notes sections
*/
ssize_t __weak elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos)
{
return read_from_oldmem(buf, count, ppos, 0, mem_encrypt_active());
}
/*
* Architectures may override this function to map oldmem
*/
int __weak remap_oldmem_pfn_range(struct vm_area_struct *vma,
unsigned long from, unsigned long pfn,
unsigned long size, pgprot_t prot)
{
prot = pgprot_encrypted(prot);
return remap_pfn_range(vma, from, pfn, size, prot);
}
/*
* Architectures which support memory encryption override this.
*/
ssize_t __weak
copy_oldmem_page_encrypted(unsigned long pfn, char *buf, size_t csize,
unsigned long offset, int userbuf)
{
return copy_oldmem_page(pfn, buf, csize, offset, userbuf);
}
/*
* Copy to either kernel or user space
*/
static int copy_to(void *target, void *src, size_t size, int userbuf)
{
if (userbuf) {
if (copy_to_user((char __user *) target, src, size))
return -EFAULT;
} else {
memcpy(target, src, size);
}
return 0;
}
#ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP
static int vmcoredd_copy_dumps(void *dst, u64 start, size_t size, int userbuf)
{
struct vmcoredd_node *dump;
u64 offset = 0;
int ret = 0;
size_t tsz;
char *buf;
mutex_lock(&vmcoredd_mutex);
list_for_each_entry(dump, &vmcoredd_list, list) {
if (start < offset + dump->size) {
tsz = min(offset + (u64)dump->size - start, (u64)size);
buf = dump->buf + start - offset;
if (copy_to(dst, buf, tsz, userbuf)) {
ret = -EFAULT;
goto out_unlock;
}
size -= tsz;
start += tsz;
dst += tsz;
/* Leave now if buffer filled already */
if (!size)
goto out_unlock;
}
offset += dump->size;
}
out_unlock:
mutex_unlock(&vmcoredd_mutex);
return ret;
}
#ifdef CONFIG_MMU
static int vmcoredd_mmap_dumps(struct vm_area_struct *vma, unsigned long dst,
u64 start, size_t size)
{
struct vmcoredd_node *dump;
u64 offset = 0;
int ret = 0;
size_t tsz;
char *buf;
mutex_lock(&vmcoredd_mutex);
list_for_each_entry(dump, &vmcoredd_list, list) {
if (start < offset + dump->size) {
tsz = min(offset + (u64)dump->size - start, (u64)size);
buf = dump->buf + start - offset;
if (remap_vmalloc_range_partial(vma, dst, buf, tsz)) {
ret = -EFAULT;
goto out_unlock;
}
size -= tsz;
start += tsz;
dst += tsz;
/* Leave now if buffer filled already */
if (!size)
goto out_unlock;
}
offset += dump->size;
}
out_unlock:
mutex_unlock(&vmcoredd_mutex);
return ret;
}
#endif /* CONFIG_MMU */
#endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */
/* Read from the ELF header and then the crash dump. On error, negative value is
* returned otherwise number of bytes read are returned.
*/
static ssize_t __read_vmcore(char *buffer, size_t buflen, loff_t *fpos,
int userbuf)
{
ssize_t acc = 0, tmp;
size_t tsz;
u64 start;
struct vmcore *m = NULL;
if (buflen == 0 || *fpos >= vmcore_size)
return 0;
/* trim buflen to not go beyond EOF */
if (buflen > vmcore_size - *fpos)
buflen = vmcore_size - *fpos;
/* Read ELF core header */
if (*fpos < elfcorebuf_sz) {
tsz = min(elfcorebuf_sz - (size_t)*fpos, buflen);
if (copy_to(buffer, elfcorebuf + *fpos, tsz, userbuf))
return -EFAULT;
buflen -= tsz;
*fpos += tsz;
buffer += tsz;
acc += tsz;
/* leave now if filled buffer already */
if (buflen == 0)
return acc;
}
/* Read Elf note segment */
if (*fpos < elfcorebuf_sz + elfnotes_sz) {
void *kaddr;
/* We add device dumps before other elf notes because the
* other elf notes may not fill the elf notes buffer
* completely and we will end up with zero-filled data
* between the elf notes and the device dumps. Tools will
* then try to decode this zero-filled data as valid notes
* and we don't want that. Hence, adding device dumps before
* the other elf notes ensure that zero-filled data can be
* avoided.
*/
#ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP
/* Read device dumps */
if (*fpos < elfcorebuf_sz + vmcoredd_orig_sz) {
tsz = min(elfcorebuf_sz + vmcoredd_orig_sz -
(size_t)*fpos, buflen);
start = *fpos - elfcorebuf_sz;
if (vmcoredd_copy_dumps(buffer, start, tsz, userbuf))
return -EFAULT;
buflen -= tsz;
*fpos += tsz;
buffer += tsz;
acc += tsz;
/* leave now if filled buffer already */
if (!buflen)
return acc;
}
#endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */
/* Read remaining elf notes */
tsz = min(elfcorebuf_sz + elfnotes_sz - (size_t)*fpos, buflen);
kaddr = elfnotes_buf + *fpos - elfcorebuf_sz - vmcoredd_orig_sz;
if (copy_to(buffer, kaddr, tsz, userbuf))
return -EFAULT;
buflen -= tsz;
*fpos += tsz;
buffer += tsz;
acc += tsz;
/* leave now if filled buffer already */
if (buflen == 0)
return acc;
}
list_for_each_entry(m, &vmcore_list, list) {
if (*fpos < m->offset + m->size) {
tsz = (size_t)min_t(unsigned long long,
m->offset + m->size - *fpos,
buflen);
start = m->paddr + *fpos - m->offset;
tmp = read_from_oldmem(buffer, tsz, &start,
userbuf, mem_encrypt_active());
if (tmp < 0)
return tmp;
buflen -= tsz;
*fpos += tsz;
buffer += tsz;
acc += tsz;
/* leave now if filled buffer already */
if (buflen == 0)
return acc;
}
}
return acc;
}
static ssize_t read_vmcore(struct file *file, char __user *buffer,
size_t buflen, loff_t *fpos)
{
return __read_vmcore((__force char *) buffer, buflen, fpos, 1);
}
/*
* The vmcore fault handler uses the page cache and fills data using the
* standard __vmcore_read() function.
*
* On s390 the fault handler is used for memory regions that can't be mapped
* directly with remap_pfn_range().
*/
static vm_fault_t mmap_vmcore_fault(struct vm_fault *vmf)
{
#ifdef CONFIG_S390
struct address_space *mapping = vmf->vma->vm_file->f_mapping;
pgoff_t index = vmf->pgoff;
struct page *page;
loff_t offset;
char *buf;
int rc;
page = find_or_create_page(mapping, index, GFP_KERNEL);
if (!page)
return VM_FAULT_OOM;
if (!PageUptodate(page)) {
offset = (loff_t) index << PAGE_SHIFT;
buf = __va((page_to_pfn(page) << PAGE_SHIFT));
rc = __read_vmcore(buf, PAGE_SIZE, &offset, 0);
if (rc < 0) {
unlock_page(page);
put_page(page);
return vmf_error(rc);
}
SetPageUptodate(page);
}
unlock_page(page);
vmf->page = page;
return 0;
#else
return VM_FAULT_SIGBUS;
#endif
}
static const struct vm_operations_struct vmcore_mmap_ops = {
.fault = mmap_vmcore_fault,
};
/**
* vmcore_alloc_buf - allocate buffer in vmalloc memory
* @sizez: size of buffer
*
* If CONFIG_MMU is defined, use vmalloc_user() to allow users to mmap
* the buffer to user-space by means of remap_vmalloc_range().
*
* If CONFIG_MMU is not defined, use vzalloc() since mmap_vmcore() is
* disabled and there's no need to allow users to mmap the buffer.
*/
static inline char *vmcore_alloc_buf(size_t size)
{
#ifdef CONFIG_MMU
return vmalloc_user(size);
#else
return vzalloc(size);
#endif
}
/*
* Disable mmap_vmcore() if CONFIG_MMU is not defined. MMU is
* essential for mmap_vmcore() in order to map physically
* non-contiguous objects (ELF header, ELF note segment and memory
* regions in the 1st kernel pointed to by PT_LOAD entries) into
* virtually contiguous user-space in ELF layout.
*/
#ifdef CONFIG_MMU
/*
* remap_oldmem_pfn_checked - do remap_oldmem_pfn_range replacing all pages
* reported as not being ram with the zero page.
*
* @vma: vm_area_struct describing requested mapping
* @from: start remapping from
* @pfn: page frame number to start remapping to
* @size: remapping size
* @prot: protection bits
*
* Returns zero on success, -EAGAIN on failure.
*/
static int remap_oldmem_pfn_checked(struct vm_area_struct *vma,
unsigned long from, unsigned long pfn,
unsigned long size, pgprot_t prot)
{
unsigned long map_size;
unsigned long pos_start, pos_end, pos;
unsigned long zeropage_pfn = my_zero_pfn(0);
size_t len = 0;
pos_start = pfn;
pos_end = pfn + (size >> PAGE_SHIFT);
for (pos = pos_start; pos < pos_end; ++pos) {
if (!pfn_is_ram(pos)) {
/*
* We hit a page which is not ram. Remap the continuous
* region between pos_start and pos-1 and replace
* the non-ram page at pos with the zero page.
*/
if (pos > pos_start) {
/* Remap continuous region */
map_size = (pos - pos_start) << PAGE_SHIFT;
if (remap_oldmem_pfn_range(vma, from + len,
pos_start, map_size,
prot))
goto fail;
len += map_size;
}
/* Remap the zero page */
if (remap_oldmem_pfn_range(vma, from + len,
zeropage_pfn,
PAGE_SIZE, prot))
goto fail;
len += PAGE_SIZE;
pos_start = pos + 1;
}
}
if (pos > pos_start) {
/* Remap the rest */
map_size = (pos - pos_start) << PAGE_SHIFT;
if (remap_oldmem_pfn_range(vma, from + len, pos_start,
map_size, prot))
goto fail;
}
return 0;
fail:
do_munmap(vma->vm_mm, from, len, NULL);
return -EAGAIN;
}
static int vmcore_remap_oldmem_pfn(struct vm_area_struct *vma,
unsigned long from, unsigned long pfn,
unsigned long size, pgprot_t prot)
{
/*
* Check if oldmem_pfn_is_ram was registered to avoid
* looping over all pages without a reason.
*/
if (oldmem_pfn_is_ram)
return remap_oldmem_pfn_checked(vma, from, pfn, size, prot);
else
return remap_oldmem_pfn_range(vma, from, pfn, size, prot);
}
static int mmap_vmcore(struct file *file, struct vm_area_struct *vma)
{
size_t size = vma->vm_end - vma->vm_start;
u64 start, end, len, tsz;
struct vmcore *m;
start = (u64)vma->vm_pgoff << PAGE_SHIFT;
end = start + size;
if (size > vmcore_size || end > vmcore_size)
return -EINVAL;
if (vma->vm_flags & (VM_WRITE | VM_EXEC))
return -EPERM;
vma->vm_flags &= ~(VM_MAYWRITE | VM_MAYEXEC);
vma->vm_flags |= VM_MIXEDMAP;
vma->vm_ops = &vmcore_mmap_ops;
len = 0;
if (start < elfcorebuf_sz) {
u64 pfn;
tsz = min(elfcorebuf_sz - (size_t)start, size);
pfn = __pa(elfcorebuf + start) >> PAGE_SHIFT;
if (remap_pfn_range(vma, vma->vm_start, pfn, tsz,
vma->vm_page_prot))
return -EAGAIN;
size -= tsz;
start += tsz;
len += tsz;
if (size == 0)
return 0;
}
if (start < elfcorebuf_sz + elfnotes_sz) {
void *kaddr;
/* We add device dumps before other elf notes because the
* other elf notes may not fill the elf notes buffer
* completely and we will end up with zero-filled data
* between the elf notes and the device dumps. Tools will
* then try to decode this zero-filled data as valid notes
* and we don't want that. Hence, adding device dumps before
* the other elf notes ensure that zero-filled data can be
* avoided. This also ensures that the device dumps and
* other elf notes can be properly mmaped at page aligned
* address.
*/
#ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP
/* Read device dumps */
if (start < elfcorebuf_sz + vmcoredd_orig_sz) {
u64 start_off;
tsz = min(elfcorebuf_sz + vmcoredd_orig_sz -
(size_t)start, size);
start_off = start - elfcorebuf_sz;
if (vmcoredd_mmap_dumps(vma, vma->vm_start + len,
start_off, tsz))
goto fail;
size -= tsz;
start += tsz;
len += tsz;
/* leave now if filled buffer already */
if (!size)
return 0;
}
#endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */
/* Read remaining elf notes */
tsz = min(elfcorebuf_sz + elfnotes_sz - (size_t)start, size);
kaddr = elfnotes_buf + start - elfcorebuf_sz - vmcoredd_orig_sz;
if (remap_vmalloc_range_partial(vma, vma->vm_start + len,
kaddr, tsz))
goto fail;
size -= tsz;
start += tsz;
len += tsz;
if (size == 0)
return 0;
}
list_for_each_entry(m, &vmcore_list, list) {
if (start < m->offset + m->size) {
u64 paddr = 0;
tsz = (size_t)min_t(unsigned long long,
m->offset + m->size - start, size);
paddr = m->paddr + start - m->offset;
if (vmcore_remap_oldmem_pfn(vma, vma->vm_start + len,
paddr >> PAGE_SHIFT, tsz,
vma->vm_page_prot))
goto fail;
size -= tsz;
start += tsz;
len += tsz;
if (size == 0)
return 0;
}
}
return 0;
fail:
do_munmap(vma->vm_mm, vma->vm_start, len, NULL);
return -EAGAIN;
}
#else
static int mmap_vmcore(struct file *file, struct vm_area_struct *vma)
{
return -ENOSYS;
}
#endif
static const struct file_operations proc_vmcore_operations = {
.read = read_vmcore,
.llseek = default_llseek,
.mmap = mmap_vmcore,
};
static struct vmcore* __init get_new_element(void)
{
return kzalloc(sizeof(struct vmcore), GFP_KERNEL);
}
static u64 get_vmcore_size(size_t elfsz, size_t elfnotesegsz,
struct list_head *vc_list)
{
u64 size;
struct vmcore *m;
size = elfsz + elfnotesegsz;
list_for_each_entry(m, vc_list, list) {
size += m->size;
}
return size;
}
/**
* update_note_header_size_elf64 - update p_memsz member of each PT_NOTE entry
*
* @ehdr_ptr: ELF header
*
* This function updates p_memsz member of each PT_NOTE entry in the
* program header table pointed to by @ehdr_ptr to real size of ELF
* note segment.
*/
static int __init update_note_header_size_elf64(const Elf64_Ehdr *ehdr_ptr)
{
int i, rc=0;
Elf64_Phdr *phdr_ptr;
Elf64_Nhdr *nhdr_ptr;
phdr_ptr = (Elf64_Phdr *)(ehdr_ptr + 1);
for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
void *notes_section;
u64 offset, max_sz, sz, real_sz = 0;
if (phdr_ptr->p_type != PT_NOTE)
continue;
max_sz = phdr_ptr->p_memsz;
offset = phdr_ptr->p_offset;
notes_section = kmalloc(max_sz, GFP_KERNEL);
if (!notes_section)
return -ENOMEM;
rc = elfcorehdr_read_notes(notes_section, max_sz, &offset);
if (rc < 0) {
kfree(notes_section);
return rc;
}
nhdr_ptr = notes_section;
while (nhdr_ptr->n_namesz != 0) {
sz = sizeof(Elf64_Nhdr) +
(((u64)nhdr_ptr->n_namesz + 3) & ~3) +
(((u64)nhdr_ptr->n_descsz + 3) & ~3);
if ((real_sz + sz) > max_sz) {
pr_warn("Warning: Exceeded p_memsz, dropping PT_NOTE entry n_namesz=0x%x, n_descsz=0x%x\n",
nhdr_ptr->n_namesz, nhdr_ptr->n_descsz);
break;
}
real_sz += sz;
nhdr_ptr = (Elf64_Nhdr*)((char*)nhdr_ptr + sz);
}
kfree(notes_section);
phdr_ptr->p_memsz = real_sz;
if (real_sz == 0) {
pr_warn("Warning: Zero PT_NOTE entries found\n");
}
}
return 0;
}
/**
* get_note_number_and_size_elf64 - get the number of PT_NOTE program
* headers and sum of real size of their ELF note segment headers and
* data.
*
* @ehdr_ptr: ELF header
* @nr_ptnote: buffer for the number of PT_NOTE program headers
* @sz_ptnote: buffer for size of unique PT_NOTE program header
*
* This function is used to merge multiple PT_NOTE program headers
* into a unique single one. The resulting unique entry will have
* @sz_ptnote in its phdr->p_mem.
*
* It is assumed that program headers with PT_NOTE type pointed to by
* @ehdr_ptr has already been updated by update_note_header_size_elf64
* and each of PT_NOTE program headers has actual ELF note segment
* size in its p_memsz member.
*/
static int __init get_note_number_and_size_elf64(const Elf64_Ehdr *ehdr_ptr,
int *nr_ptnote, u64 *sz_ptnote)
{
int i;
Elf64_Phdr *phdr_ptr;
*nr_ptnote = *sz_ptnote = 0;
phdr_ptr = (Elf64_Phdr *)(ehdr_ptr + 1);
for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
if (phdr_ptr->p_type != PT_NOTE)
continue;
*nr_ptnote += 1;
*sz_ptnote += phdr_ptr->p_memsz;
}
return 0;
}
/**
* copy_notes_elf64 - copy ELF note segments in a given buffer
*
* @ehdr_ptr: ELF header
* @notes_buf: buffer into which ELF note segments are copied
*
* This function is used to copy ELF note segment in the 1st kernel
* into the buffer @notes_buf in the 2nd kernel. It is assumed that
* size of the buffer @notes_buf is equal to or larger than sum of the
* real ELF note segment headers and data.
*
* It is assumed that program headers with PT_NOTE type pointed to by
* @ehdr_ptr has already been updated by update_note_header_size_elf64
* and each of PT_NOTE program headers has actual ELF note segment
* size in its p_memsz member.
*/
static int __init copy_notes_elf64(const Elf64_Ehdr *ehdr_ptr, char *notes_buf)
{
int i, rc=0;
Elf64_Phdr *phdr_ptr;
phdr_ptr = (Elf64_Phdr*)(ehdr_ptr + 1);
for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
u64 offset;
if (phdr_ptr->p_type != PT_NOTE)
continue;
offset = phdr_ptr->p_offset;
rc = elfcorehdr_read_notes(notes_buf, phdr_ptr->p_memsz,
&offset);
if (rc < 0)
return rc;
notes_buf += phdr_ptr->p_memsz;
}
return 0;
}
/* Merges all the PT_NOTE headers into one. */
static int __init merge_note_headers_elf64(char *elfptr, size_t *elfsz,
char **notes_buf, size_t *notes_sz)
{
int i, nr_ptnote=0, rc=0;
char *tmp;
Elf64_Ehdr *ehdr_ptr;
Elf64_Phdr phdr;
u64 phdr_sz = 0, note_off;
ehdr_ptr = (Elf64_Ehdr *)elfptr;
rc = update_note_header_size_elf64(ehdr_ptr);
if (rc < 0)
return rc;
rc = get_note_number_and_size_elf64(ehdr_ptr, &nr_ptnote, &phdr_sz);
if (rc < 0)
return rc;
*notes_sz = roundup(phdr_sz, PAGE_SIZE);
*notes_buf = vmcore_alloc_buf(*notes_sz);
if (!*notes_buf)
return -ENOMEM;
rc = copy_notes_elf64(ehdr_ptr, *notes_buf);
if (rc < 0)
return rc;
/* Prepare merged PT_NOTE program header. */
phdr.p_type = PT_NOTE;
phdr.p_flags = 0;
note_off = sizeof(Elf64_Ehdr) +
(ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf64_Phdr);
phdr.p_offset = roundup(note_off, PAGE_SIZE);
phdr.p_vaddr = phdr.p_paddr = 0;
phdr.p_filesz = phdr.p_memsz = phdr_sz;
phdr.p_align = 0;
/* Add merged PT_NOTE program header*/
tmp = elfptr + sizeof(Elf64_Ehdr);
memcpy(tmp, &phdr, sizeof(phdr));
tmp += sizeof(phdr);
/* Remove unwanted PT_NOTE program headers. */
i = (nr_ptnote - 1) * sizeof(Elf64_Phdr);
*elfsz = *elfsz - i;
memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf64_Ehdr)-sizeof(Elf64_Phdr)));
memset(elfptr + *elfsz, 0, i);
*elfsz = roundup(*elfsz, PAGE_SIZE);
/* Modify e_phnum to reflect merged headers. */
ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1;
/* Store the size of all notes. We need this to update the note
* header when the device dumps will be added.
*/
elfnotes_orig_sz = phdr.p_memsz;
return 0;
}
/**
* update_note_header_size_elf32 - update p_memsz member of each PT_NOTE entry
*
* @ehdr_ptr: ELF header
*
* This function updates p_memsz member of each PT_NOTE entry in the
* program header table pointed to by @ehdr_ptr to real size of ELF
* note segment.
*/
static int __init update_note_header_size_elf32(const Elf32_Ehdr *ehdr_ptr)
{
int i, rc=0;
Elf32_Phdr *phdr_ptr;
Elf32_Nhdr *nhdr_ptr;
phdr_ptr = (Elf32_Phdr *)(ehdr_ptr + 1);
for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
void *notes_section;
u64 offset, max_sz, sz, real_sz = 0;
if (phdr_ptr->p_type != PT_NOTE)
continue;
max_sz = phdr_ptr->p_memsz;
offset = phdr_ptr->p_offset;
notes_section = kmalloc(max_sz, GFP_KERNEL);
if (!notes_section)
return -ENOMEM;
rc = elfcorehdr_read_notes(notes_section, max_sz, &offset);
if (rc < 0) {
kfree(notes_section);
return rc;
}
nhdr_ptr = notes_section;
while (nhdr_ptr->n_namesz != 0) {
sz = sizeof(Elf32_Nhdr) +
(((u64)nhdr_ptr->n_namesz + 3) & ~3) +
(((u64)nhdr_ptr->n_descsz + 3) & ~3);
if ((real_sz + sz) > max_sz) {
pr_warn("Warning: Exceeded p_memsz, dropping PT_NOTE entry n_namesz=0x%x, n_descsz=0x%x\n",
nhdr_ptr->n_namesz, nhdr_ptr->n_descsz);
break;
}
real_sz += sz;
nhdr_ptr = (Elf32_Nhdr*)((char*)nhdr_ptr + sz);
}
kfree(notes_section);
phdr_ptr->p_memsz = real_sz;
if (real_sz == 0) {
pr_warn("Warning: Zero PT_NOTE entries found\n");
}
}
return 0;
}
/**
* get_note_number_and_size_elf32 - get the number of PT_NOTE program
* headers and sum of real size of their ELF note segment headers and
* data.
*
* @ehdr_ptr: ELF header
* @nr_ptnote: buffer for the number of PT_NOTE program headers
* @sz_ptnote: buffer for size of unique PT_NOTE program header
*
* This function is used to merge multiple PT_NOTE program headers
* into a unique single one. The resulting unique entry will have
* @sz_ptnote in its phdr->p_mem.
*
* It is assumed that program headers with PT_NOTE type pointed to by
* @ehdr_ptr has already been updated by update_note_header_size_elf32
* and each of PT_NOTE program headers has actual ELF note segment
* size in its p_memsz member.
*/
static int __init get_note_number_and_size_elf32(const Elf32_Ehdr *ehdr_ptr,
int *nr_ptnote, u64 *sz_ptnote)
{
int i;
Elf32_Phdr *phdr_ptr;
*nr_ptnote = *sz_ptnote = 0;
phdr_ptr = (Elf32_Phdr *)(ehdr_ptr + 1);
for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
if (phdr_ptr->p_type != PT_NOTE)
continue;
*nr_ptnote += 1;
*sz_ptnote += phdr_ptr->p_memsz;
}
return 0;
}
/**
* copy_notes_elf32 - copy ELF note segments in a given buffer
*
* @ehdr_ptr: ELF header
* @notes_buf: buffer into which ELF note segments are copied
*
* This function is used to copy ELF note segment in the 1st kernel
* into the buffer @notes_buf in the 2nd kernel. It is assumed that
* size of the buffer @notes_buf is equal to or larger than sum of the
* real ELF note segment headers and data.
*
* It is assumed that program headers with PT_NOTE type pointed to by
* @ehdr_ptr has already been updated by update_note_header_size_elf32
* and each of PT_NOTE program headers has actual ELF note segment
* size in its p_memsz member.
*/
static int __init copy_notes_elf32(const Elf32_Ehdr *ehdr_ptr, char *notes_buf)
{
int i, rc=0;
Elf32_Phdr *phdr_ptr;
phdr_ptr = (Elf32_Phdr*)(ehdr_ptr + 1);
for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
u64 offset;
if (phdr_ptr->p_type != PT_NOTE)
continue;
offset = phdr_ptr->p_offset;
rc = elfcorehdr_read_notes(notes_buf, phdr_ptr->p_memsz,
&offset);
if (rc < 0)
return rc;
notes_buf += phdr_ptr->p_memsz;
}
return 0;
}
/* Merges all the PT_NOTE headers into one. */
static int __init merge_note_headers_elf32(char *elfptr, size_t *elfsz,
char **notes_buf, size_t *notes_sz)
{
int i, nr_ptnote=0, rc=0;
char *tmp;
Elf32_Ehdr *ehdr_ptr;
Elf32_Phdr phdr;
u64 phdr_sz = 0, note_off;
ehdr_ptr = (Elf32_Ehdr *)elfptr;
rc = update_note_header_size_elf32(ehdr_ptr);
if (rc < 0)
return rc;
rc = get_note_number_and_size_elf32(ehdr_ptr, &nr_ptnote, &phdr_sz);
if (rc < 0)
return rc;
*notes_sz = roundup(phdr_sz, PAGE_SIZE);
*notes_buf = vmcore_alloc_buf(*notes_sz);
if (!*notes_buf)
return -ENOMEM;
rc = copy_notes_elf32(ehdr_ptr, *notes_buf);
if (rc < 0)
return rc;
/* Prepare merged PT_NOTE program header. */
phdr.p_type = PT_NOTE;
phdr.p_flags = 0;
note_off = sizeof(Elf32_Ehdr) +
(ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf32_Phdr);
phdr.p_offset = roundup(note_off, PAGE_SIZE);
phdr.p_vaddr = phdr.p_paddr = 0;
phdr.p_filesz = phdr.p_memsz = phdr_sz;
phdr.p_align = 0;
/* Add merged PT_NOTE program header*/
tmp = elfptr + sizeof(Elf32_Ehdr);
memcpy(tmp, &phdr, sizeof(phdr));
tmp += sizeof(phdr);
/* Remove unwanted PT_NOTE program headers. */
i = (nr_ptnote - 1) * sizeof(Elf32_Phdr);
*elfsz = *elfsz - i;
memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf32_Ehdr)-sizeof(Elf32_Phdr)));
memset(elfptr + *elfsz, 0, i);
*elfsz = roundup(*elfsz, PAGE_SIZE);
/* Modify e_phnum to reflect merged headers. */
ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1;
/* Store the size of all notes. We need this to update the note
* header when the device dumps will be added.
*/
elfnotes_orig_sz = phdr.p_memsz;
return 0;
}
/* Add memory chunks represented by program headers to vmcore list. Also update
* the new offset fields of exported program headers. */
static int __init process_ptload_program_headers_elf64(char *elfptr,
size_t elfsz,
size_t elfnotes_sz,
struct list_head *vc_list)
{
int i;
Elf64_Ehdr *ehdr_ptr;
Elf64_Phdr *phdr_ptr;
loff_t vmcore_off;
struct vmcore *new;
ehdr_ptr = (Elf64_Ehdr *)elfptr;
phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr)); /* PT_NOTE hdr */
/* Skip Elf header, program headers and Elf note segment. */
vmcore_off = elfsz + elfnotes_sz;
for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
u64 paddr, start, end, size;
if (phdr_ptr->p_type != PT_LOAD)
continue;
paddr = phdr_ptr->p_offset;
start = rounddown(paddr, PAGE_SIZE);
end = roundup(paddr + phdr_ptr->p_memsz, PAGE_SIZE);
size = end - start;
/* Add this contiguous chunk of memory to vmcore list.*/
new = get_new_element();
if (!new)
return -ENOMEM;
new->paddr = start;
new->size = size;
list_add_tail(&new->list, vc_list);
/* Update the program header offset. */
phdr_ptr->p_offset = vmcore_off + (paddr - start);
vmcore_off = vmcore_off + size;
}
return 0;
}
static int __init process_ptload_program_headers_elf32(char *elfptr,
size_t elfsz,
size_t elfnotes_sz,
struct list_head *vc_list)
{
int i;
Elf32_Ehdr *ehdr_ptr;
Elf32_Phdr *phdr_ptr;
loff_t vmcore_off;
struct vmcore *new;
ehdr_ptr = (Elf32_Ehdr *)elfptr;
phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr)); /* PT_NOTE hdr */
/* Skip Elf header, program headers and Elf note segment. */
vmcore_off = elfsz + elfnotes_sz;
for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
u64 paddr, start, end, size;
if (phdr_ptr->p_type != PT_LOAD)
continue;
paddr = phdr_ptr->p_offset;
start = rounddown(paddr, PAGE_SIZE);
end = roundup(paddr + phdr_ptr->p_memsz, PAGE_SIZE);
size = end - start;
/* Add this contiguous chunk of memory to vmcore list.*/
new = get_new_element();
if (!new)
return -ENOMEM;
new->paddr = start;
new->size = size;
list_add_tail(&new->list, vc_list);
/* Update the program header offset */
phdr_ptr->p_offset = vmcore_off + (paddr - start);
vmcore_off = vmcore_off + size;
}
return 0;
}
/* Sets offset fields of vmcore elements. */
static void set_vmcore_list_offsets(size_t elfsz, size_t elfnotes_sz,
struct list_head *vc_list)
{
loff_t vmcore_off;
struct vmcore *m;
/* Skip Elf header, program headers and Elf note segment. */
vmcore_off = elfsz + elfnotes_sz;
list_for_each_entry(m, vc_list, list) {
m->offset = vmcore_off;
vmcore_off += m->size;
}
}
static void free_elfcorebuf(void)
{
free_pages((unsigned long)elfcorebuf, get_order(elfcorebuf_sz_orig));
elfcorebuf = NULL;
vfree(elfnotes_buf);
elfnotes_buf = NULL;
}
static int __init parse_crash_elf64_headers(void)
{
int rc=0;
Elf64_Ehdr ehdr;
u64 addr;
addr = elfcorehdr_addr;
/* Read Elf header */
rc = elfcorehdr_read((char *)&ehdr, sizeof(Elf64_Ehdr), &addr);
if (rc < 0)
return rc;
/* Do some basic Verification. */
if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0 ||
(ehdr.e_type != ET_CORE) ||
!vmcore_elf64_check_arch(&ehdr) ||
ehdr.e_ident[EI_CLASS] != ELFCLASS64 ||
ehdr.e_ident[EI_VERSION] != EV_CURRENT ||
ehdr.e_version != EV_CURRENT ||
ehdr.e_ehsize != sizeof(Elf64_Ehdr) ||
ehdr.e_phentsize != sizeof(Elf64_Phdr) ||
ehdr.e_phnum == 0) {
pr_warn("Warning: Core image elf header is not sane\n");
return -EINVAL;
}
/* Read in all elf headers. */
elfcorebuf_sz_orig = sizeof(Elf64_Ehdr) +
ehdr.e_phnum * sizeof(Elf64_Phdr);
elfcorebuf_sz = elfcorebuf_sz_orig;
elfcorebuf = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
get_order(elfcorebuf_sz_orig));
if (!elfcorebuf)
return -ENOMEM;
addr = elfcorehdr_addr;
rc = elfcorehdr_read(elfcorebuf, elfcorebuf_sz_orig, &addr);
if (rc < 0)
goto fail;
/* Merge all PT_NOTE headers into one. */
rc = merge_note_headers_elf64(elfcorebuf, &elfcorebuf_sz,
&elfnotes_buf, &elfnotes_sz);
if (rc)
goto fail;
rc = process_ptload_program_headers_elf64(elfcorebuf, elfcorebuf_sz,
elfnotes_sz, &vmcore_list);
if (rc)
goto fail;
set_vmcore_list_offsets(elfcorebuf_sz, elfnotes_sz, &vmcore_list);
return 0;
fail:
free_elfcorebuf();
return rc;
}
static int __init parse_crash_elf32_headers(void)
{
int rc=0;
Elf32_Ehdr ehdr;
u64 addr;
addr = elfcorehdr_addr;
/* Read Elf header */
rc = elfcorehdr_read((char *)&ehdr, sizeof(Elf32_Ehdr), &addr);
if (rc < 0)
return rc;
/* Do some basic Verification. */
if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0 ||
(ehdr.e_type != ET_CORE) ||
!vmcore_elf32_check_arch(&ehdr) ||
ehdr.e_ident[EI_CLASS] != ELFCLASS32||
ehdr.e_ident[EI_VERSION] != EV_CURRENT ||
ehdr.e_version != EV_CURRENT ||
ehdr.e_ehsize != sizeof(Elf32_Ehdr) ||
ehdr.e_phentsize != sizeof(Elf32_Phdr) ||
ehdr.e_phnum == 0) {
pr_warn("Warning: Core image elf header is not sane\n");
return -EINVAL;
}
/* Read in all elf headers. */
elfcorebuf_sz_orig = sizeof(Elf32_Ehdr) + ehdr.e_phnum * sizeof(Elf32_Phdr);
elfcorebuf_sz = elfcorebuf_sz_orig;
elfcorebuf = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
get_order(elfcorebuf_sz_orig));
if (!elfcorebuf)
return -ENOMEM;
addr = elfcorehdr_addr;
rc = elfcorehdr_read(elfcorebuf, elfcorebuf_sz_orig, &addr);
if (rc < 0)
goto fail;
/* Merge all PT_NOTE headers into one. */
rc = merge_note_headers_elf32(elfcorebuf, &elfcorebuf_sz,
&elfnotes_buf, &elfnotes_sz);
if (rc)
goto fail;
rc = process_ptload_program_headers_elf32(elfcorebuf, elfcorebuf_sz,
elfnotes_sz, &vmcore_list);
if (rc)
goto fail;
set_vmcore_list_offsets(elfcorebuf_sz, elfnotes_sz, &vmcore_list);
return 0;
fail:
free_elfcorebuf();
return rc;
}
static int __init parse_crash_elf_headers(void)
{
unsigned char e_ident[EI_NIDENT];
u64 addr;
int rc=0;
addr = elfcorehdr_addr;
rc = elfcorehdr_read(e_ident, EI_NIDENT, &addr);
if (rc < 0)
return rc;
if (memcmp(e_ident, ELFMAG, SELFMAG) != 0) {
pr_warn("Warning: Core image elf header not found\n");
return -EINVAL;
}
if (e_ident[EI_CLASS] == ELFCLASS64) {
rc = parse_crash_elf64_headers();
if (rc)
return rc;
} else if (e_ident[EI_CLASS] == ELFCLASS32) {
rc = parse_crash_elf32_headers();
if (rc)
return rc;
} else {
pr_warn("Warning: Core image elf header is not sane\n");
return -EINVAL;
}
/* Determine vmcore size. */
vmcore_size = get_vmcore_size(elfcorebuf_sz, elfnotes_sz,
&vmcore_list);
return 0;
}
#ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP
/**
* vmcoredd_write_header - Write vmcore device dump header at the
* beginning of the dump's buffer.
* @buf: Output buffer where the note is written
* @data: Dump info
* @size: Size of the dump
*
* Fills beginning of the dump's buffer with vmcore device dump header.
*/
static void vmcoredd_write_header(void *buf, struct vmcoredd_data *data,
u32 size)
{
struct vmcoredd_header *vdd_hdr = (struct vmcoredd_header *)buf;
vdd_hdr->n_namesz = sizeof(vdd_hdr->name);
vdd_hdr->n_descsz = size + sizeof(vdd_hdr->dump_name);
vdd_hdr->n_type = NT_VMCOREDD;
strncpy((char *)vdd_hdr->name, VMCOREDD_NOTE_NAME,
sizeof(vdd_hdr->name));
memcpy(vdd_hdr->dump_name, data->dump_name, sizeof(vdd_hdr->dump_name));
}
/**
* vmcoredd_update_program_headers - Update all Elf program headers
* @elfptr: Pointer to elf header
* @elfnotesz: Size of elf notes aligned to page size
* @vmcoreddsz: Size of device dumps to be added to elf note header
*
* Determine type of Elf header (Elf64 or Elf32) and update the elf note size.
* Also update the offsets of all the program headers after the elf note header.
*/
static void vmcoredd_update_program_headers(char *elfptr, size_t elfnotesz,
size_t vmcoreddsz)
{
unsigned char *e_ident = (unsigned char *)elfptr;
u64 start, end, size;
loff_t vmcore_off;
u32 i;
vmcore_off = elfcorebuf_sz + elfnotesz;
if (e_ident[EI_CLASS] == ELFCLASS64) {
Elf64_Ehdr *ehdr = (Elf64_Ehdr *)elfptr;
Elf64_Phdr *phdr = (Elf64_Phdr *)(elfptr + sizeof(Elf64_Ehdr));
/* Update all program headers */
for (i = 0; i < ehdr->e_phnum; i++, phdr++) {
if (phdr->p_type == PT_NOTE) {
/* Update note size */
phdr->p_memsz = elfnotes_orig_sz + vmcoreddsz;
phdr->p_filesz = phdr->p_memsz;
continue;
}
start = rounddown(phdr->p_offset, PAGE_SIZE);
end = roundup(phdr->p_offset + phdr->p_memsz,
PAGE_SIZE);
size = end - start;
phdr->p_offset = vmcore_off + (phdr->p_offset - start);
vmcore_off += size;
}
} else {
Elf32_Ehdr *ehdr = (Elf32_Ehdr *)elfptr;
Elf32_Phdr *phdr = (Elf32_Phdr *)(elfptr + sizeof(Elf32_Ehdr));
/* Update all program headers */
for (i = 0; i < ehdr->e_phnum; i++, phdr++) {
if (phdr->p_type == PT_NOTE) {
/* Update note size */
phdr->p_memsz = elfnotes_orig_sz + vmcoreddsz;
phdr->p_filesz = phdr->p_memsz;
continue;
}
start = rounddown(phdr->p_offset, PAGE_SIZE);
end = roundup(phdr->p_offset + phdr->p_memsz,
PAGE_SIZE);
size = end - start;
phdr->p_offset = vmcore_off + (phdr->p_offset - start);
vmcore_off += size;
}
}
}
/**
* vmcoredd_update_size - Update the total size of the device dumps and update
* Elf header
* @dump_size: Size of the current device dump to be added to total size
*
* Update the total size of all the device dumps and update the Elf program
* headers. Calculate the new offsets for the vmcore list and update the
* total vmcore size.
*/
static void vmcoredd_update_size(size_t dump_size)
{
vmcoredd_orig_sz += dump_size;
elfnotes_sz = roundup(elfnotes_orig_sz, PAGE_SIZE) + vmcoredd_orig_sz;
vmcoredd_update_program_headers(elfcorebuf, elfnotes_sz,
vmcoredd_orig_sz);
/* Update vmcore list offsets */
set_vmcore_list_offsets(elfcorebuf_sz, elfnotes_sz, &vmcore_list);
vmcore_size = get_vmcore_size(elfcorebuf_sz, elfnotes_sz,
&vmcore_list);
proc_vmcore->size = vmcore_size;
}
/**
* vmcore_add_device_dump - Add a buffer containing device dump to vmcore
* @data: dump info.
*
* Allocate a buffer and invoke the calling driver's dump collect routine.
* Write Elf note at the beginning of the buffer to indicate vmcore device
* dump and add the dump to global list.
*/
int vmcore_add_device_dump(struct vmcoredd_data *data)
{
struct vmcoredd_node *dump;
void *buf = NULL;
size_t data_size;
int ret;
if (vmcoredd_disabled) {
pr_err_once("Device dump is disabled\n");
return -EINVAL;
}
if (!data || !strlen(data->dump_name) ||
!data->vmcoredd_callback || !data->size)
return -EINVAL;
dump = vzalloc(sizeof(*dump));
if (!dump) {
ret = -ENOMEM;
goto out_err;
}
/* Keep size of the buffer page aligned so that it can be mmaped */
data_size = roundup(sizeof(struct vmcoredd_header) + data->size,
PAGE_SIZE);
/* Allocate buffer for driver's to write their dumps */
buf = vmcore_alloc_buf(data_size);
if (!buf) {
ret = -ENOMEM;
goto out_err;
}
vmcoredd_write_header(buf, data, data_size -
sizeof(struct vmcoredd_header));
/* Invoke the driver's dump collection routing */
ret = data->vmcoredd_callback(data, buf +
sizeof(struct vmcoredd_header));
if (ret)
goto out_err;
dump->buf = buf;
dump->size = data_size;
/* Add the dump to driver sysfs list */
mutex_lock(&vmcoredd_mutex);
list_add_tail(&dump->list, &vmcoredd_list);
mutex_unlock(&vmcoredd_mutex);
vmcoredd_update_size(data_size);
return 0;
out_err:
if (buf)
vfree(buf);
if (dump)
vfree(dump);
return ret;
}
EXPORT_SYMBOL(vmcore_add_device_dump);
#endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */
/* Free all dumps in vmcore device dump list */
static void vmcore_free_device_dumps(void)
{
#ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP
mutex_lock(&vmcoredd_mutex);
while (!list_empty(&vmcoredd_list)) {
struct vmcoredd_node *dump;
dump = list_first_entry(&vmcoredd_list, struct vmcoredd_node,
list);
list_del(&dump->list);
vfree(dump->buf);
vfree(dump);
}
mutex_unlock(&vmcoredd_mutex);
#endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */
}
/* Init function for vmcore module. */
static int __init vmcore_init(void)
{
int rc = 0;
/* Allow architectures to allocate ELF header in 2nd kernel */
rc = elfcorehdr_alloc(&elfcorehdr_addr, &elfcorehdr_size);
if (rc)
return rc;
/*
* If elfcorehdr= has been passed in cmdline or created in 2nd kernel,
* then capture the dump.
*/
if (!(is_vmcore_usable()))
return rc;
rc = parse_crash_elf_headers();
if (rc) {
pr_warn("Kdump: vmcore not initialized\n");
return rc;
}
elfcorehdr_free(elfcorehdr_addr);
elfcorehdr_addr = ELFCORE_ADDR_ERR;
proc_vmcore = proc_create("vmcore", S_IRUSR, NULL, &proc_vmcore_operations);
if (proc_vmcore)
proc_vmcore->size = vmcore_size;
return 0;
}
fs_initcall(vmcore_init);
/* Cleanup function for vmcore module. */
void vmcore_cleanup(void)
{
if (proc_vmcore) {
proc_remove(proc_vmcore);
proc_vmcore = NULL;
}
/* clear the vmcore list. */
while (!list_empty(&vmcore_list)) {
struct vmcore *m;
m = list_first_entry(&vmcore_list, struct vmcore, list);
list_del(&m->list);
kfree(m);
}
free_elfcorebuf();
/* clear vmcore device dump list */
vmcore_free_device_dumps();
}
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