1 files changed, 12 insertions, 10 deletions

diff --git a/drivers/char/nvram.c b/drivers/char/nvram.c
index 88cee4099be9..5eb83c3ca20d 100644
--- a/drivers/char/nvram.c
+++ b/drivers/char/nvram.c
@@ -38,7 +38,6 @@
 #define NVRAM_VERSION   "1.3"
 
 #include <linux/module.h>
-#include <linux/smp_lock.h>
 #include <linux/nvram.h>
 
 #define PC              1
@@ -111,6 +110,7 @@
 #include <linux/spinlock.h>
 #include <linux/io.h>
 #include <linux/uaccess.h>
+#include <linux/smp_lock.h>
 
 #include <asm/system.h>
 
@@ -214,7 +214,6 @@ void nvram_set_checksum(void)
 
 static loff_t nvram_llseek(struct file *file, loff_t offset, int origin)
 {
-        lock_kernel();
         switch (origin) {
         case 0:
                 /* nothing to do */
@@ -226,7 +225,7 @@ static loff_t nvram_llseek(struct file *file, loff_t offset, int origin)
                 offset += NVRAM_BYTES;
                 break;
         }
-        unlock_kernel();
+
         return (offset >= 0) ? (file->f_pos = offset) : -EINVAL;
 }
 
@@ -265,10 +264,16 @@ static ssize_t nvram_write(struct file *file, const char __user *buf,
         unsigned char contents[NVRAM_BYTES];
         unsigned i = *ppos;
         unsigned char *tmp;
-        int len;
 
-        len = (NVRAM_BYTES - i) < count ? (NVRAM_BYTES - i) : count;
-        if (copy_from_user(contents, buf, len))
+        if (i >= NVRAM_BYTES)
+                return 0;       /* Past EOF */
+
+        if (count > NVRAM_BYTES - i)
+                count = NVRAM_BYTES - i;
+        if (count > NVRAM_BYTES)
+                return -EFAULT; /* Can't happen, but prove it to gcc */
+
+        if (copy_from_user(contents, buf, count))
                 return -EFAULT;
 
         spin_lock_irq(&rtc_lock);
@@ -276,7 +281,7 @@ static ssize_t nvram_write(struct file *file, const char __user *buf,
         if (!__nvram_check_checksum())
                 goto checksum_err;
 
-        for (tmp = contents; count-- > 0 && i < NVRAM_BYTES; ++i, ++tmp)
+        for (tmp = contents; count--; ++i, ++tmp)
                 __nvram_write_byte(*tmp, i);
 
         __nvram_set_checksum();
@@ -331,14 +336,12 @@ static int nvram_ioctl(struct inode *inode, struct file *file,
 
 static int nvram_open(struct inode *inode, struct file *file)
 {
-        lock_kernel();
         spin_lock(&nvram_state_lock);
 
         if ((nvram_open_cnt && (file->f_flags & O_EXCL)) ||
             (nvram_open_mode & NVRAM_EXCL) ||
             ((file->f_mode & FMODE_WRITE) && (nvram_open_mode & NVRAM_WRITE))) {
                 spin_unlock(&nvram_state_lock);
-                unlock_kernel();
                 return -EBUSY;
         }
 
@@ -349,7 +352,6 @@ static int nvram_open(struct inode *inode, struct file *file)
         nvram_open_cnt++;
 
         spin_unlock(&nvram_state_lock);
-        unlock_kernel();
 
         return 0;
 }