[PATCH 3/5] Bluetooth: btmrvl: One check less in btmrvl_sdio_card_to_host() after error detection

[SF Markus Elfring]

From: Markus Elfring <elfr...@users.sourceforge.net>
Date: Mon, 12 Mar 2018 11:13:00 +0100

One check could be repeated by the btmrvl_sdio_card_to_host() function
during error handling even if the relevant properties can be determined
for the involved variables before by source code analysis.

* Adjust jump targets so that an extra check can be omitted at the end.

* Reuse a bit of exception handling better.

* Delete an initialisation for the local variable "skb"
  which became unnecessary with this refactoring.

Signed-off-by: Markus Elfring <elfr...@users.sourceforge.net>
---
 drivers/bluetooth/btmrvl_sdio.c | 35 ++++++++++++++++++-----------------
 1 file changed, 18 insertions(+), 17 deletions(-)

diff --git a/drivers/bluetooth/btmrvl_sdio.c b/drivers/bluetooth/btmrvl_sdio.c
index 84c222abf0f7..9854addc8e96 100644
--- a/drivers/bluetooth/btmrvl_sdio.c
+++ b/drivers/bluetooth/btmrvl_sdio.c
@@ -687,5 +687,5 @@ static int btmrvl_sdio_card_to_host(struct btmrvl_private 
*priv)
 {
        u16 buf_len = 0;
        int ret, num_blocks, blksz;
-       struct sk_buff *skb = NULL;
+       struct sk_buff *skb;
        u32 type;
@@ -695,16 +695,14 @@ static int btmrvl_sdio_card_to_host(struct btmrvl_private 
*priv)
 
        if (!card || !card->func) {
                BT_ERR("card or function is NULL!");
-               ret = -EINVAL;
-               goto exit;
+               goto e_inval;
        }
 
        /* Read the length of data to be transferred */
        ret = btmrvl_sdio_read_rx_len(card, &buf_len);
        if (ret < 0) {
                BT_ERR("read rx_len failed");
-               ret = -EIO;
-               goto exit;
+               goto e_io;
        }
 
        blksz = SDIO_BLOCK_SIZE;
@@ -713,8 +711,7 @@ static int btmrvl_sdio_card_to_host(struct btmrvl_private 
*priv)
        if (buf_len <= SDIO_HEADER_LEN
            || (num_blocks * blksz) > ALLOC_BUF_SIZE) {
                BT_ERR("invalid packet length: %d", buf_len);
-               ret = -EINVAL;
-               goto exit;
+               goto e_inval;
        }
 
        /* Allocate buffer */
@@ -722,7 +719,7 @@ static int btmrvl_sdio_card_to_host(struct btmrvl_private 
*priv)
        if (!skb) {
                BT_ERR("No free skb");
                ret = -ENOMEM;
-               goto exit;
+               goto increment_counter;
        }
 
        if ((unsigned long) skb->data & (BTSDIO_DMA_ALIGN - 1)) {
@@ -738,8 +735,7 @@ static int btmrvl_sdio_card_to_host(struct btmrvl_private 
*priv)
                          num_blocks * blksz);
        if (ret < 0) {
                BT_ERR("readsb failed: %d", ret);
-               ret = -EIO;
-               goto exit;
+               goto free_skb;
        }
 
        /* This is SDIO specific header length: byte[2][1][0], type: byte[3]
@@ -753,8 +749,7 @@ static int btmrvl_sdio_card_to_host(struct btmrvl_private 
*priv)
        if (buf_len > blksz * num_blocks) {
                BT_ERR("Skip incorrect packet: hdrlen %d buffer %d",
                       buf_len, blksz * num_blocks);
-               ret = -EIO;
-               goto exit;
+               goto free_skb;
        }
 
        type = payload[3];
@@ -797,12 +792,18 @@ static int btmrvl_sdio_card_to_host(struct btmrvl_private 
*priv)
                break;
        }
 
-exit:
-       if (ret) {
-               hdev->stat.err_rx++;
-               kfree_skb(skb);
-       }
+       return 0;
+
+free_skb:
+       kfree_skb(skb);
+e_io:
+       ret = -EIO;
+       goto increment_counter;
 
+e_inval:
+       ret = -EINVAL;
+increment_counter:
+       hdev->stat.err_rx++;
        return ret;
 }
 
-- 
2.16.2