From b6c48ddf6d91aa462672df297df8c7e912355988 Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx@linutronix.de>
Date: Fri, 9 Oct 2009 20:31:33 +0200
Subject: [PATCH] --- yaml --- r: 173189 b: refs/heads/master c:
 6f15fa50087c8317e353145319466afbeb27a75d h: refs/heads/master i:   173187:
 077d37c64345bcb74699671b817c8c0d24e48418 v: v3

---
 [refs]             |  2 +-
 trunk/kernel/sys.c | 14 +++++++-------
 2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/[refs] b/[refs]
index 7a6321dbdf5b..f8c3e0318e35 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 1a6deaea3584fd7af1cad492b1fe0867060b45db
+refs/heads/master: 6f15fa50087c8317e353145319466afbeb27a75d
diff --git a/trunk/kernel/sys.c b/trunk/kernel/sys.c
index 255475d163e0..22ea9553c3bc 100644
--- a/trunk/kernel/sys.c
+++ b/trunk/kernel/sys.c
@@ -8,7 +8,6 @@
 #include <linux/mm.h>
 #include <linux/utsname.h>
 #include <linux/mman.h>
-#include <linux/smp_lock.h>
 #include <linux/notifier.h>
 #include <linux/reboot.h>
 #include <linux/prctl.h>
@@ -349,6 +348,9 @@ void kernel_power_off(void)
 	machine_power_off();
 }
 EXPORT_SYMBOL_GPL(kernel_power_off);
+
+static DEFINE_MUTEX(reboot_mutex);
+
 /*
  * Reboot system call: for obvious reasons only root may call it,
  * and even root needs to set up some magic numbers in the registers
@@ -381,7 +383,7 @@ SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd,
 	if ((cmd == LINUX_REBOOT_CMD_POWER_OFF) && !pm_power_off)
 		cmd = LINUX_REBOOT_CMD_HALT;
 
-	lock_kernel();
+	mutex_lock(&reboot_mutex);
 	switch (cmd) {
 	case LINUX_REBOOT_CMD_RESTART:
 		kernel_restart(NULL);
@@ -397,20 +399,18 @@ SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd,
 
 	case LINUX_REBOOT_CMD_HALT:
 		kernel_halt();
-		unlock_kernel();
 		do_exit(0);
 		panic("cannot halt");
 
 	case LINUX_REBOOT_CMD_POWER_OFF:
 		kernel_power_off();
-		unlock_kernel();
 		do_exit(0);
 		break;
 
 	case LINUX_REBOOT_CMD_RESTART2:
 		if (strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1) < 0) {
-			unlock_kernel();
-			return -EFAULT;
+			ret = -EFAULT;
+			break;
 		}
 		buffer[sizeof(buffer) - 1] = '\0';
 
@@ -433,7 +433,7 @@ SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd,
 		ret = -EINVAL;
 		break;
 	}
-	unlock_kernel();
+	mutex_unlock(&reboot_mutex);
 	return ret;
 }