50 lines
1 KiB
C
50 lines
1 KiB
C
|
/*
|
||
|
|
* kernel/crash_dump.c - Memory preserving reboot related code.
|
||
|
|
*
|
||
|
|
* Created by: Hariprasad Nellitheertha (hari@in.ibm.com)
|
||
|
|
* Copyright (C) IBM Corporation, 2004. All rights reserved
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <linux/smp_lock.h>
|
||
|
|
#include <linux/errno.h>
|
||
|
|
#include <linux/proc_fs.h>
|
||
|
|
#include <linux/bootmem.h>
|
||
|
|
#include <linux/highmem.h>
|
||
|
|
#include <linux/crash_dump.h>
|
||
|
|
|
||
|
|
#include <asm/io.h>
|
||
|
|
#include <asm/uaccess.h>
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Copy a page from "oldmem". For this page, there is no pte mapped
|
||
|
|
* in the current kernel. We stitch up a pte, similar to kmap_atomic.
|
||
|
|
*/
|
||
|
|
ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
|
||
|
|
size_t csize, unsigned long offset, int userbuf)
|
||
|
|
{
|
||
|
|
void *page, *vaddr;
|
||
|
|
|
||
|
|
if (!csize)
|
||
|
|
return 0;
|
||
|
|
|
||
|
|
page = kmalloc(PAGE_SIZE, GFP_KERNEL);
|
||
|
|
if (!page)
|
||
|
|
return -ENOMEM;
|
||
|
|
|
||
|
|
vaddr = kmap_atomic_pfn(pfn, KM_PTE0);
|
||
|
|
copy_page(page, vaddr);
|
||
|
|
kunmap_atomic(vaddr, KM_PTE0);
|
||
|
|
|
||
|
|
if (userbuf) {
|
||
|
|
if (copy_to_user(buf, (page + offset), csize)) {
|
||
|
|
kfree(page);
|
||
|
|
return -EFAULT;
|
||
|
|
}
|
||
|
|
} else {
|
||
|
|
memcpy(buf, (page + offset), csize);
|
||
|
|
}
|
||
|
|
|
||
|
|
kfree(page);
|
||
|
|
return csize;
|
||
|
|
}
|