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

[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / char / nvram.c

diff --git a/drivers/char/nvram.c b/drivers/char/nvram.c
index 88cee4099be940c294127d0a172996d90c597912..5eb83c3ca20de35be340031015a93495ae19e12b 100644 (file)
--- 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;
 }