[PATCH] kexec: add kexec syscalls

This patch introduces the architecture independent implementation the
sys_kexec_load, the compat_sys_kexec_load system calls.

Kexec on panic support has been integrated into the core patch and is
relatively clean.

In addition the hopefully architecture independent option
crashkernel=size@location has been docuemented.  It's purpose is to reserve
space for the panic kernel to live, and where no DMA transfer will ever be
setup to access.

Signed-off-by: Eric Biederman <ebiederm@xmission.com>
Signed-off-by: Alexander Nyberg <alexn@telia.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
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>

1 files changed, 20 insertions, 0 deletions

diff --git a/kernel/sys.c b/kernel/sys.c
index dac10161ca23..9a24374c23bc 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -16,6 +16,8 @@
 #include <linux/init.h>
 #include <linux/highuid.h>
 #include <linux/fs.h>
+#include <linux/kernel.h>
+#include <linux/kexec.h>
 #include <linux/workqueue.h>
 #include <linux/device.h>
 #include <linux/key.h>
@@ -439,6 +441,24 @@ asmlinkage long sys_reboot(int magic1, int magic2, unsigned int cmd, void __user
                 machine_restart(buffer);
                 break;
 
+#ifdef CONFIG_KEXEC
+        case LINUX_REBOOT_CMD_KEXEC:
+        {
+                struct kimage *image;
+                image = xchg(&kexec_image, 0);
+                if (!image) {
+                        unlock_kernel();
+                        return -EINVAL;
+                }
+                notifier_call_chain(&reboot_notifier_list, SYS_RESTART, NULL);
+                system_state = SYSTEM_RESTART;
+                device_shutdown();
+                printk(KERN_EMERG "Starting new kernel\n");
+                machine_shutdown();
+                machine_kexec(image);
+                break;
+        }
+#endif
 #ifdef CONFIG_SOFTWARE_SUSPEND
         case LINUX_REBOOT_CMD_SW_SUSPEND:
                 {