binfmt_misc: use simple_read_from_buffer()

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 3 insertions, 17 deletions

diff --git a/fs/binfmt_misc.c b/fs/binfmt_misc.c
index 7191306367c5..756205314c24 100644
--- a/fs/binfmt_misc.c
+++ b/fs/binfmt_misc.c
@@ -27,6 +27,7 @@
 #include <linux/namei.h>
 #include <linux/mount.h>
 #include <linux/syscalls.h>
+#include <linux/fs.h>
 
 #include <asm/uaccess.h>
 
@@ -535,31 +536,16 @@ static ssize_t
 bm_entry_read(struct file * file, char __user * buf, size_t nbytes, loff_t *ppos)
 {
         Node *e = file->f_path.dentry->d_inode->i_private;
-        loff_t pos = *ppos;
         ssize_t res;
         char *page;
-        int len;
 
         if (!(page = (char*) __get_free_page(GFP_KERNEL)))
                 return -ENOMEM;
 
         entry_status(e, page);
-        len = strlen(page);
 
-        res = -EINVAL;
-        if (pos < 0)
-                goto out;
-        res = 0;
-        if (pos >= len)
-                goto out;
-        if (len < pos + nbytes)
-                nbytes = len - pos;
-        res = -EFAULT;
-        if (copy_to_user(buf, page + pos, nbytes))
-                goto out;
-        *ppos = pos + nbytes;
-        res = nbytes;
-out:
+        res = simple_read_from_buffer(buf, nbytes, ppos, page, strlen(page));
+
         free_page((unsigned long) page);
         return res;
 }