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1582 lines
40 KiB
1582 lines
40 KiB
// 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 ([email protected]) |
|
* 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/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) |
|
{ |
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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); |
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list_for_each_entry(dump, &vmcoredd_list, list) { |
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if (start < offset + dump->size) { |
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tsz = min(offset + (u64)dump->size - start, (u64)size); |
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buf = dump->buf + start - offset; |
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if (copy_to(dst, buf, tsz, userbuf)) { |
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ret = -EFAULT; |
|
goto out_unlock; |
|
} |
|
|
|
size -= tsz; |
|
start += tsz; |
|
dst += tsz; |
|
|
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/* 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, 0, |
|
tsz)) { |
|
ret = -EFAULT; |
|
goto out_unlock; |
|
} |
|
|
|
size -= tsz; |
|
start += tsz; |
|
dst += tsz; |
|
|
|
/* Leave now if buffer filled already */ |
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if (!size) |
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goto out_unlock; |
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} |
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offset += dump->size; |
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} |
|
|
|
out_unlock: |
|
mutex_unlock(&vmcoredd_mutex); |
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return ret; |
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} |
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#endif /* CONFIG_MMU */ |
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#endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */ |
|
|
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/* Read from the ELF header and then the crash dump. On error, negative value is |
|
* returned otherwise number of bytes read are returned. |
|
*/ |
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static ssize_t __read_vmcore(char *buffer, size_t buflen, loff_t *fpos, |
|
int userbuf) |
|
{ |
|
ssize_t acc = 0, tmp; |
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size_t tsz; |
|
u64 start; |
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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); |
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if (copy_to(buffer, elfcorebuf + *fpos, tsz, userbuf)) |
|
return -EFAULT; |
|
buflen -= tsz; |
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*fpos += tsz; |
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buffer += tsz; |
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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, 0, 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 proc_ops vmcore_proc_ops = { |
|
.proc_read = read_vmcore, |
|
.proc_lseek = default_llseek, |
|
.proc_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: |
|
vfree(buf); |
|
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, &vmcore_proc_ops); |
|
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(); |
|
}
|
|
|