devcoredump: use memory_read_from_buffer

Use memory_read_from_buffer() to simplify devcd_readv().

Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Link: https://lore.kernel.org/r/1564243146-5681-2-git-send-email-akinobu.mita@gmail.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Link: https://lore.kernel.org/r/20190731100007.32684-1-johannes@sipsolutions.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/base/devcoredump.c b/drivers/base/devcoredump.c
index f1a3353..3c960a6 100644 (file)
--- a/drivers/base/devcoredump.c
+++ b/drivers/base/devcoredump.c
@@ -164,16 +164,7 @@ static struct class devcd_class = {
 static ssize_t devcd_readv(char *buffer, loff_t offset, size_t count,
                           void *data, size_t datalen)
 {
-       if (offset > datalen)
-               return -EINVAL;
-
-       if (offset + count > datalen)
-               count = datalen - offset;
-
-       if (count)
-               memcpy(buffer, ((u8 *)data) + offset, count);
-
-       return count;
+       return memory_read_from_buffer(buffer, count, &offset, data, datalen);
 }
 
 static void devcd_freev(void *data)