2 files changed, 65 insertions, 23 deletions

diff --git a/kernel/kexec.c b/kernel/kexec.c
index 6db42ff8d520..a0d920915b38 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -24,6 +24,8 @@
 #include <linux/utsrelease.h>
 #include <linux/utsname.h>
 #include <linux/numa.h>
+#include <linux/suspend.h>
+#include <linux/device.h>
 
 #include <asm/page.h>
 #include <asm/uaccess.h>
@@ -242,6 +244,12 @@ static int kimage_normal_alloc(struct kimage **rimage, unsigned long entry,
                 goto out;
         }
 
+        image->swap_page = kimage_alloc_control_pages(image, 0);
+        if (!image->swap_page) {
+                printk(KERN_ERR "Could not allocate swap buffer\n");
+                goto out;
+        }
+
         result = 0;
  out:
         if (result == 0)
@@ -986,6 +994,8 @@ asmlinkage long sys_kexec_load(unsigned long entry, unsigned long nr_segments,
                 if (result)
                         goto out;
 
+                if (flags & KEXEC_PRESERVE_CONTEXT)
+                        image->preserve_context = 1;
                 result = machine_kexec_prepare(image);
                 if (result)
                         goto out;
@@ -1411,3 +1421,50 @@ static int __init crash_save_vmcoreinfo_init(void)
 }
 
 module_init(crash_save_vmcoreinfo_init)
+
+/**
+ *      kernel_kexec - reboot the system
+ *
+ *      Move into place and start executing a preloaded standalone
+ *      executable.  If nothing was preloaded return an error.
+ */
+int kernel_kexec(void)
+{
+        int error = 0;
+
+        if (xchg(&kexec_lock, 1))
+                return -EBUSY;
+        if (!kexec_image) {
+                error = -EINVAL;
+                goto Unlock;
+        }
+
+        if (kexec_image->preserve_context) {
+#ifdef CONFIG_KEXEC_JUMP
+                local_irq_disable();
+                save_processor_state();
+#endif
+        } else {
+                blocking_notifier_call_chain(&reboot_notifier_list,
+                                             SYS_RESTART, NULL);
+                system_state = SYSTEM_RESTART;
+                device_shutdown();
+                sysdev_shutdown();
+                printk(KERN_EMERG "Starting new kernel\n");
+                machine_shutdown();
+        }
+
+        machine_kexec(kexec_image);
+
+        if (kexec_image->preserve_context) {
+#ifdef CONFIG_KEXEC_JUMP
+                restore_processor_state();
+                local_irq_enable();
+#endif
+        }
+
+ Unlock:
+        xchg(&kexec_lock, 0);
+
+        return error;
+}
diff --git a/kernel/sys.c b/kernel/sys.c
index 0c9d3fa1f5ff..c01858090a98 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -301,26 +301,6 @@ void kernel_restart(char *cmd)
 }
 EXPORT_SYMBOL_GPL(kernel_restart);
 
-/**
- *      kernel_kexec - reboot the system
- *
- *      Move into place and start executing a preloaded standalone
- *      executable.  If nothing was preloaded return an error.
- */
-static void kernel_kexec(void)
-{
-#ifdef CONFIG_KEXEC
-        struct kimage *image;
-        image = xchg(&kexec_image, NULL);
-        if (!image)
-                return;
-        kernel_restart_prepare(NULL);
-        printk(KERN_EMERG "Starting new kernel\n");
-        machine_shutdown();
-        machine_kexec(image);
-#endif
-}
-
 static void kernel_shutdown_prepare(enum system_states state)
 {
         blocking_notifier_call_chain(&reboot_notifier_list,
@@ -425,10 +405,15 @@ asmlinkage long sys_reboot(int magic1, int magic2, unsigned int cmd, void __user
                 kernel_restart(buffer);
                 break;
 
+#ifdef CONFIG_KEXEC
         case LINUX_REBOOT_CMD_KEXEC:
-                kernel_kexec();
-                unlock_kernel();
-                return -EINVAL;
+                {
+                        int ret;
+                        ret = kernel_kexec();
+                        unlock_kernel();
+                        return ret;
+                }
+#endif
 
 #ifdef CONFIG_HIBERNATION
         case LINUX_REBOOT_CMD_SW_SUSPEND: