[PATCH] kdump: Access dump file in elf format (/proc/vmcore)

From: "Vivek Goyal" <vgoyal@in.ibm.com>

o Support for /proc/vmcore interface. This interface exports elf core image
  either in ELF32 or ELF64 format, depending on the format in which elf headers
  have been stored by crashed kernel.
o Added support for CONFIG_VMCORE config option.
o Removed the dependency on /proc/kcore.

From: "Eric W. Biederman" <ebiederm@xmission.com>

This patch has been refactored to more closely match the prevailing style in
the affected files.  And to clearly indicate the dependency between
/proc/kcore and proc/vmcore.c

From: Hariprasad Nellitheertha <hari@in.ibm.com>

This patch contains the code that provides an ELF format interface to the
previous kernel's memory post kexec reboot.

Signed off by Hariprasad Nellitheertha <hari@in.ibm.com>
Signed-off-by: Eric Biederman <ebiederm@xmission.com>
Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

include/linux/crash_dump.h

@@ -7,8 +7,12 @@
 #include <linux/device.h>
 #include <linux/proc_fs.h>
 
+#define ELFCORE_ADDR_MAX	(-1ULL)
 extern unsigned long long elfcorehdr_addr;
 extern ssize_t copy_oldmem_page(unsigned long, char *, size_t,
 						unsigned long, int);
+extern struct file_operations proc_vmcore_operations;
+extern struct proc_dir_entry *proc_vmcore;
+
 #endif /* CONFIG_CRASH_DUMP */
 #endif /* LINUX_CRASHDUMP_H */

include/linux/proc_fs.h

@@ -74,6 +74,13 @@ struct kcore_list {
 	size_t size;
 };
 
+struct vmcore {
+	struct list_head list;
+	unsigned long long paddr;
+	unsigned long size;
+	loff_t offset;
+};
+
 #ifdef CONFIG_PROC_FS
 
 extern struct proc_dir_entry proc_root;