2 files changed, 15 insertions, 19 deletions

diff --git a/kernel/pm_qos_params.c b/kernel/pm_qos_params.c
index dfdec524d1b7..3db49b9ca374 100644
--- a/kernel/pm_qos_params.c
+++ b/kernel/pm_qos_params.c
@@ -29,7 +29,6 @@
 
 #include <linux/pm_qos_params.h>
 #include <linux/sched.h>
-#include <linux/smp_lock.h>
 #include <linux/spinlock.h>
 #include <linux/slab.h>
 #include <linux/time.h>
@@ -344,37 +343,33 @@ int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier)
 }
 EXPORT_SYMBOL_GPL(pm_qos_remove_notifier);
 
-#define PID_NAME_LEN sizeof("process_1234567890")
-static char name[PID_NAME_LEN];
+#define PID_NAME_LEN 32
 
 static int pm_qos_power_open(struct inode *inode, struct file *filp)
 {
         int ret;
         long pm_qos_class;
+        char name[PID_NAME_LEN];
 
-        lock_kernel();
         pm_qos_class = find_pm_qos_object_by_minor(iminor(inode));
         if (pm_qos_class >= 0) {
                 filp->private_data = (void *)pm_qos_class;
-                sprintf(name, "process_%d", current->pid);
+                snprintf(name, PID_NAME_LEN, "process_%d", current->pid);
                 ret = pm_qos_add_requirement(pm_qos_class, name,
                                         PM_QOS_DEFAULT_VALUE);
-                if (ret >= 0) {
-                        unlock_kernel();
+                if (ret >= 0)
                         return 0;
-                }
         }
-        unlock_kernel();
-
         return -EPERM;
 }
 
 static int pm_qos_power_release(struct inode *inode, struct file *filp)
 {
         int pm_qos_class;
+        char name[PID_NAME_LEN];
 
         pm_qos_class = (long)filp->private_data;
-        sprintf(name, "process_%d", current->pid);
+        snprintf(name, PID_NAME_LEN, "process_%d", current->pid);
         pm_qos_remove_requirement(pm_qos_class, name);
 
         return 0;
@@ -385,13 +380,14 @@ static ssize_t pm_qos_power_write(struct file *filp, const char __user *buf,
 {
         s32 value;
         int pm_qos_class;
+        char name[PID_NAME_LEN];
 
         pm_qos_class = (long)filp->private_data;
         if (count != sizeof(s32))
                 return -EINVAL;
         if (copy_from_user(&value, buf, sizeof(s32)))
                 return -EFAULT;
-        sprintf(name, "process_%d", current->pid);
+        snprintf(name, PID_NAME_LEN, "process_%d", current->pid);
         pm_qos_update_requirement(pm_qos_class, name, value);
 
         return  sizeof(s32);
diff --git a/kernel/sys.c b/kernel/sys.c
index 9968c5fb55b9..585d6cd10040 100644
--- a/kernel/sys.c
+++ b/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;
 }