Return-Path: Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 11.2 \(3445.5.20\)) Subject: Re: [PATCH 3/5] Bluetooth: btmrvl: One check less in btmrvl_sdio_card_to_host() after error detection From: Marcel Holtmann In-Reply-To: Date: Mon, 12 Mar 2018 17:12:51 +0100 Cc: linux-bluetooth@vger.kernel.org, Johan Hedberg , LKML , kernel-janitors@vger.kernel.org Message-Id: <609D1B28-2B75-4AB5-B707-FDB5D0500F1A@holtmann.org> References: <8d050f76-aed1-7b6b-8778-a78aef34d4ea@users.sourceforge.net> To: SF Markus Elfring Sender: linux-kernel-owner@vger.kernel.org List-ID: Hi Markus, > 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 > --- > 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; Nope! This is not easier to read for me. This goto exit jumping and I hate that. Actually to be honest this kind of goto jumping makes my brain hurt and I want to avoid it. Regards Marcel