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-rw-r--r--kernel/Makefile1
-rw-r--r--kernel/crash_dump.c49
2 files changed, 50 insertions, 0 deletions
diff --git a/kernel/Makefile b/kernel/Makefile
index cfc8b0dea950..cb05cd05d237 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -28,6 +28,7 @@ obj-$(CONFIG_AUDITSYSCALL) += auditsc.o
28obj-$(CONFIG_KPROBES) += kprobes.o 28obj-$(CONFIG_KPROBES) += kprobes.o
29obj-$(CONFIG_SYSFS) += ksysfs.o 29obj-$(CONFIG_SYSFS) += ksysfs.o
30obj-$(CONFIG_GENERIC_HARDIRQS) += irq/ 30obj-$(CONFIG_GENERIC_HARDIRQS) += irq/
31obj-$(CONFIG_CRASH_DUMP) += crash_dump.o
31obj-$(CONFIG_SECCOMP) += seccomp.o 32obj-$(CONFIG_SECCOMP) += seccomp.o
32 33
33ifneq ($(CONFIG_SCHED_NO_NO_OMIT_FRAME_POINTER),y) 34ifneq ($(CONFIG_SCHED_NO_NO_OMIT_FRAME_POINTER),y)
diff --git a/kernel/crash_dump.c b/kernel/crash_dump.c
new file mode 100644
index 000000000000..5a1e6d5d203e
--- /dev/null
+++ b/kernel/crash_dump.c
@@ -0,0 +1,49 @@
1/*
2 * kernel/crash_dump.c - Memory preserving reboot related code.
3 *
4 * Created by: Hariprasad Nellitheertha (hari@in.ibm.com)
5 * Copyright (C) IBM Corporation, 2004. All rights reserved
6 */
7
8#include <linux/smp_lock.h>
9#include <linux/errno.h>
10#include <linux/proc_fs.h>
11#include <linux/bootmem.h>
12#include <linux/highmem.h>
13#include <linux/crash_dump.h>
14
15#include <asm/io.h>
16#include <asm/uaccess.h>
17
18/*
19 * Copy a page from "oldmem". For this page, there is no pte mapped
20 * in the current kernel. We stitch up a pte, similar to kmap_atomic.
21 */
22ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
23 size_t csize, unsigned long offset, int userbuf)
24{
25 void *page, *vaddr;
26
27 if (!csize)
28 return 0;
29
30 page = kmalloc(PAGE_SIZE, GFP_KERNEL);
31 if (!page)
32 return -ENOMEM;
33
34 vaddr = kmap_atomic_pfn(pfn, KM_PTE0);
35 copy_page(page, vaddr);
36 kunmap_atomic(vaddr, KM_PTE0);
37
38 if (userbuf) {
39 if (copy_to_user(buf, (page + offset), csize)) {
40 kfree(page);
41 return -EFAULT;
42 }
43 } else {
44 memcpy(buf, (page + offset), csize);
45 }
46
47 kfree(page);
48 return csize;
49}