use simple_read_from_buffer in kernel/

Cleanup using simple_read_from_buffer() for /dev/cpuset/tasks and
/proc/config.gz.

Cc: Paul Jackson <pj@sgi.com>
Cc: Randy Dunlap <rdunlap@xenotime.net>
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, 12 deletions

diff --git a/kernel/configs.c b/kernel/configs.c
index 8fa1fb28f8a7..e84d3f9c6c7b 100644
--- a/kernel/configs.c
+++ b/kernel/configs.c
@@ -61,18 +61,9 @@ static ssize_t
 ikconfig_read_current(struct file *file, char __user *buf,
                       size_t len, loff_t * offset)
 {
-        loff_t pos = *offset;
-        ssize_t count;
-
-        if (pos >= kernel_config_data_size)
-                return 0;
-
-        count = min(len, (size_t)(kernel_config_data_size - pos));
-        if (copy_to_user(buf, kernel_config_data + MAGIC_SIZE + pos, count))
-                return -EFAULT;
-
-        *offset += count;
-        return count;
+        return simple_read_from_buffer(buf, len, offset,
+                                       kernel_config_data + MAGIC_SIZE,
+                                       kernel_config_data_size);
 }
 
 static const struct file_operations ikconfig_file_ops = {