Thomas Gleixner | d2912cb | 2019-06-04 10:11:33 +0200 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0-only |
Mika Westerberg | 67742c8 | 2010-05-10 09:26:19 +0100 | [diff] [blame] | 2 | /* |
| 3 | * arch/arm/kernel/crash_dump.c |
| 4 | * |
| 5 | * Copyright (C) 2010 Nokia Corporation. |
| 6 | * Author: Mika Westerberg |
| 7 | * |
| 8 | * This code is taken from arch/x86/kernel/crash_dump_64.c |
| 9 | * Created by: Hariprasad Nellitheertha (hari@in.ibm.com) |
| 10 | * Copyright (C) IBM Corporation, 2004. All rights reserved |
Mika Westerberg | 67742c8 | 2010-05-10 09:26:19 +0100 | [diff] [blame] | 11 | */ |
| 12 | |
| 13 | #include <linux/errno.h> |
| 14 | #include <linux/crash_dump.h> |
| 15 | #include <linux/uaccess.h> |
| 16 | #include <linux/io.h> |
| 17 | |
Mika Westerberg | 67742c8 | 2010-05-10 09:26:19 +0100 | [diff] [blame] | 18 | /** |
| 19 | * copy_oldmem_page() - copy one page from old kernel memory |
| 20 | * @pfn: page frame number to be copied |
| 21 | * @buf: buffer where the copied page is placed |
| 22 | * @csize: number of bytes to copy |
| 23 | * @offset: offset in bytes into the page |
| 24 | * @userbuf: if set, @buf is int he user address space |
| 25 | * |
| 26 | * This function copies one page from old kernel memory into buffer pointed by |
| 27 | * @buf. If @buf is in userspace, set @userbuf to %1. Returns number of bytes |
| 28 | * copied or negative error in case of failure. |
| 29 | */ |
| 30 | ssize_t copy_oldmem_page(unsigned long pfn, char *buf, |
| 31 | size_t csize, unsigned long offset, |
| 32 | int userbuf) |
| 33 | { |
| 34 | void *vaddr; |
| 35 | |
| 36 | if (!csize) |
| 37 | return 0; |
| 38 | |
Liu Hua | 8fad87b | 2014-03-27 06:56:18 +0100 | [diff] [blame] | 39 | vaddr = ioremap(__pfn_to_phys(pfn), PAGE_SIZE); |
Mika Westerberg | 67742c8 | 2010-05-10 09:26:19 +0100 | [diff] [blame] | 40 | if (!vaddr) |
| 41 | return -ENOMEM; |
| 42 | |
| 43 | if (userbuf) { |
| 44 | if (copy_to_user(buf, vaddr + offset, csize)) { |
| 45 | iounmap(vaddr); |
| 46 | return -EFAULT; |
| 47 | } |
| 48 | } else { |
| 49 | memcpy(buf, vaddr + offset, csize); |
| 50 | } |
| 51 | |
| 52 | iounmap(vaddr); |
| 53 | return csize; |
| 54 | } |