Contributors: 3
| Author |
Tokens |
Token Proportion |
Commits |
Commit Proportion |
| Ralf Baechle |
87 |
89.69% |
1 |
33.33% |
| Youling Tang |
9 |
9.28% |
1 |
33.33% |
| Greg Kroah-Hartman |
1 |
1.03% |
1 |
33.33% |
| Total |
97 |
|
3 |
|
// SPDX-License-Identifier: GPL-2.0
#include <linux/highmem.h>
#include <linux/crash_dump.h>
/**
* copy_oldmem_page - copy one page from "oldmem"
* @pfn: page frame number to be copied
* @buf: target memory address for the copy; this can be in kernel address
* space or user address space (see @userbuf)
* @csize: number of bytes to copy
* @offset: offset in bytes into the page (based on pfn) to begin the copy
* @userbuf: if set, @buf is in user address space, use copy_to_user(),
* otherwise @buf is in kernel address space, use memcpy().
*
* Copy a page from "oldmem". For this page, there is no pte mapped
* in the current kernel.
*/
ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
size_t csize, unsigned long offset, int userbuf)
{
void *vaddr;
if (!csize)
return 0;
vaddr = kmap_local_pfn(pfn);
if (!userbuf) {
memcpy(buf, vaddr + offset, csize);
} else {
if (copy_to_user(buf, vaddr + offset, csize))
csize = -EFAULT;
}
kunmap_local(vaddr);
return csize;
}