Merge branches 'futexes-for-linus', 'irq-core-for-linus' and 'bkl-drivers-for-linus...

[linux-drm-fsl-dcu.git] / drivers / char / nvram.c

diff --git a/drivers/char/nvram.c b/drivers/char/nvram.c
index 7cf4518c030f2b3a9293c23dd599643739758d1c..5eb83c3ca20de35be340031015a93495ae19e12b 100644 (file)
--- a/drivers/char/nvram.c
+++ b/drivers/char/nvram.c
@@ -110,6 +110,7 @@
 #include <linux/spinlock.h>
 #include <linux/io.h>
 #include <linux/uaccess.h>
+#include <linux/smp_lock.h>
 
 #include <asm/system.h>
 
@@ -263,10 +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);
@@ -274,7 +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();