[PATCH 5.4 10/18] can: kvaser_usb: hydra: help gcc-13 to figure out cmd_len

23 Feb 2023

From: Marc Kleine-Budde mkl@pengutronix.de
[ Upstream commit f006229135b7debf4037adb1eb93e358559593db ]
Debian's gcc-13 [1] throws the following error in
kvaser_usb_hydra_cmd_size():
[1] gcc version 13.0.0 20221214 (experimental) [master r13-4693-g512098a3316] (Debian 13-20221214-1)
| drivers/net/can/usb/kvaser_usb/kvaser_usb_hydra.c:502:65: error:
| array subscript ‘struct kvaser_cmd_ext[0]’ is partly outside array
| bounds of ‘unsigned char[32]’ [-Werror=array-bounds=]
|   502 |                 ret = le16_to_cpu(((struct kvaser_cmd_ext *)cmd)->len);
kvaser_usb_hydra_cmd_size() returns the size of given command. It
depends on the command number (cmd->header.cmd_no). For extended
commands (cmd->header.cmd_no == CMD_EXTENDED) the above shown code is
executed.
Help gcc to recognize that this code path is not taken in all cases,
by calling kvaser_usb_hydra_cmd_size() directly after assigning the
command number.
Fixes: aec5fb2268b7 ("can: kvaser_usb: Add support for Kvaser USB hydra family")
Cc: Jimmy Assarsson extja@kvaser.com
Cc: Anssi Hannula anssi.hannula@bitwise.fi
Link: https://lore.kernel.org/all/20221219110104.1073881-1-mkl@pengutronix.de
Tested-by: Jimmy Assarsson extja@kvaser.com
Signed-off-by: Marc Kleine-Budde mkl@pengutronix.de
Signed-off-by: Sasha Levin sashal@kernel.org
---
 .../net/can/usb/kvaser_usb/kvaser_usb_hydra.c | 33 ++++++++++++++-----
 1 file changed, 24 insertions(+), 9 deletions(-)

diff --git a/drivers/net/can/usb/kvaser_usb/kvaser_usb_hydra.c b/drivers/net/can/usb/kvaser_usb/kvaser_usb_hydra.c
index 2764fdd7e84b3..233bbfeaa771e 100644
--- a/drivers/net/can/usb/kvaser_usb/kvaser_usb_hydra.c
+++ b/drivers/net/can/usb/kvaser_usb/kvaser_usb_hydra.c
@@ -518,6 +518,7 @@ static int kvaser_usb_hydra_send_simple_cmd(struct kvaser_usb *dev,
    				    u8 cmd_no, int channel)
 {
    struct kvaser_cmd *cmd;
+	size_t cmd_len;
    int err;
cmd = kcalloc(1, sizeof(struct kvaser_cmd), GFP_KERNEL);
@@ -525,6 +526,7 @@ static int kvaser_usb_hydra_send_simple_cmd(struct kvaser_usb *dev,
    	return -ENOMEM;
cmd->header.cmd_no = cmd_no;
+	cmd_len = kvaser_usb_hydra_cmd_size(cmd);
    if (channel < 0) {
    	kvaser_usb_hydra_set_cmd_dest_he
    			(cmd, KVASER_USB_HYDRA_HE_ADDRESS_ILLEGAL);
@@ -541,7 +543,7 @@ static int kvaser_usb_hydra_send_simple_cmd(struct kvaser_usb *dev,
    kvaser_usb_hydra_set_cmd_transid
    			(cmd, kvaser_usb_hydra_get_next_transid(dev));
-	err = kvaser_usb_send_cmd(dev, cmd, kvaser_usb_hydra_cmd_size(cmd));
+	err = kvaser_usb_send_cmd(dev, cmd, cmd_len);
    if (err)
    	goto end;
@@ -557,6 +559,7 @@ kvaser_usb_hydra_send_simple_cmd_async(struct kvaser_usb_net_priv *priv,
 {
    struct kvaser_cmd *cmd;
    struct kvaser_usb *dev = priv->dev;
+	size_t cmd_len;
    int err;
cmd = kcalloc(1, sizeof(struct kvaser_cmd), GFP_ATOMIC);
@@ -564,14 +567,14 @@ kvaser_usb_hydra_send_simple_cmd_async(struct kvaser_usb_net_priv *priv,
    	return -ENOMEM;
cmd->header.cmd_no = cmd_no;
+	cmd_len = kvaser_usb_hydra_cmd_size(cmd);
kvaser_usb_hydra_set_cmd_dest_he
    	(cmd, dev->card_data.hydra.channel_to_he[priv->channel]);
    kvaser_usb_hydra_set_cmd_transid
    			(cmd, kvaser_usb_hydra_get_next_transid(dev));
-	err = kvaser_usb_send_cmd_async(priv, cmd,
-					kvaser_usb_hydra_cmd_size(cmd));
+	err = kvaser_usb_send_cmd_async(priv, cmd, cmd_len);
    if (err)
    	kfree(cmd);
@@ -715,6 +718,7 @@ static int kvaser_usb_hydra_get_single_capability(struct kvaser_usb *dev,
 {
    struct kvaser_usb_dev_card_data *card_data = &dev->card_data;
    struct kvaser_cmd *cmd;
+	size_t cmd_len;
    u32 value = 0;
    u32 mask = 0;
    u16 cap_cmd_res;
@@ -726,13 +730,14 @@ static int kvaser_usb_hydra_get_single_capability(struct kvaser_usb *dev,
    	return -ENOMEM;
cmd->header.cmd_no = CMD_GET_CAPABILITIES_REQ;
+	cmd_len = kvaser_usb_hydra_cmd_size(cmd);
    cmd->cap_req.cap_cmd = cpu_to_le16(cap_cmd_req);
kvaser_usb_hydra_set_cmd_dest_he(cmd, card_data->hydra.sysdbg_he);
    kvaser_usb_hydra_set_cmd_transid
    			(cmd, kvaser_usb_hydra_get_next_transid(dev));
-	err = kvaser_usb_send_cmd(dev, cmd, kvaser_usb_hydra_cmd_size(cmd));
+	err = kvaser_usb_send_cmd(dev, cmd, cmd_len);
    if (err)
    	goto end;
@@ -1555,6 +1560,7 @@ static int kvaser_usb_hydra_get_busparams(struct kvaser_usb_net_priv *priv,
    struct kvaser_usb *dev = priv->dev;
    struct kvaser_usb_net_hydra_priv *hydra = priv->sub_priv;
    struct kvaser_cmd *cmd;
+	size_t cmd_len;
    int err;
if (!hydra)
@@ -1565,6 +1571,7 @@ static int kvaser_usb_hydra_get_busparams(struct kvaser_usb_net_priv *priv,
    	return -ENOMEM;
cmd->header.cmd_no = CMD_GET_BUSPARAMS_REQ;
+	cmd_len = kvaser_usb_hydra_cmd_size(cmd);
    kvaser_usb_hydra_set_cmd_dest_he
    	(cmd, dev->card_data.hydra.channel_to_he[priv->channel]);
    kvaser_usb_hydra_set_cmd_transid
@@ -1574,7 +1581,7 @@ static int kvaser_usb_hydra_get_busparams(struct kvaser_usb_net_priv *priv,
reinit_completion(&priv->get_busparams_comp);
-	err = kvaser_usb_send_cmd(dev, cmd, kvaser_usb_hydra_cmd_size(cmd));
+	err = kvaser_usb_send_cmd(dev, cmd, cmd_len);
    if (err)
    	return err;
@@ -1601,6 +1608,7 @@ static int kvaser_usb_hydra_set_bittiming(const struct net_device *netdev,
    struct kvaser_cmd *cmd;
    struct kvaser_usb_net_priv *priv = netdev_priv(netdev);
    struct kvaser_usb *dev = priv->dev;
+	size_t cmd_len;
    int err;
cmd = kcalloc(1, sizeof(struct kvaser_cmd), GFP_KERNEL);
@@ -1608,6 +1616,7 @@ static int kvaser_usb_hydra_set_bittiming(const struct net_device *netdev,
    	return -ENOMEM;
cmd->header.cmd_no = CMD_SET_BUSPARAMS_REQ;
+	cmd_len = kvaser_usb_hydra_cmd_size(cmd);
    memcpy(&cmd->set_busparams_req.busparams_nominal, busparams,
           sizeof(cmd->set_busparams_req.busparams_nominal));
@@ -1616,7 +1625,7 @@ static int kvaser_usb_hydra_set_bittiming(const struct net_device *netdev,
    kvaser_usb_hydra_set_cmd_transid
    			(cmd, kvaser_usb_hydra_get_next_transid(dev));
-	err = kvaser_usb_send_cmd(dev, cmd, kvaser_usb_hydra_cmd_size(cmd));
+	err = kvaser_usb_send_cmd(dev, cmd, cmd_len);
kfree(cmd);
@@ -1629,6 +1638,7 @@ static int kvaser_usb_hydra_set_data_bittiming(const struct net_device *netdev,
    struct kvaser_cmd *cmd;
    struct kvaser_usb_net_priv *priv = netdev_priv(netdev);
    struct kvaser_usb *dev = priv->dev;
+	size_t cmd_len;
    int err;
cmd = kcalloc(1, sizeof(struct kvaser_cmd), GFP_KERNEL);
@@ -1636,6 +1646,7 @@ static int kvaser_usb_hydra_set_data_bittiming(const struct net_device *netdev,
    	return -ENOMEM;
cmd->header.cmd_no = CMD_SET_BUSPARAMS_FD_REQ;
+	cmd_len = kvaser_usb_hydra_cmd_size(cmd);
    memcpy(&cmd->set_busparams_req.busparams_data, busparams,
           sizeof(cmd->set_busparams_req.busparams_data));
@@ -1653,7 +1664,7 @@ static int kvaser_usb_hydra_set_data_bittiming(const struct net_device *netdev,
    kvaser_usb_hydra_set_cmd_transid
    			(cmd, kvaser_usb_hydra_get_next_transid(dev));
-	err = kvaser_usb_send_cmd(dev, cmd, kvaser_usb_hydra_cmd_size(cmd));
+	err = kvaser_usb_send_cmd(dev, cmd, cmd_len);
kfree(cmd);
@@ -1781,6 +1792,7 @@ static int kvaser_usb_hydra_get_software_info(struct kvaser_usb *dev)
 static int kvaser_usb_hydra_get_software_details(struct kvaser_usb *dev)
 {
    struct kvaser_cmd *cmd;
+	size_t cmd_len;
    int err;
    u32 flags;
    struct kvaser_usb_dev_card_data *card_data = &dev->card_data;
@@ -1790,6 +1802,7 @@ static int kvaser_usb_hydra_get_software_details(struct kvaser_usb *dev)
    	return -ENOMEM;
cmd->header.cmd_no = CMD_GET_SOFTWARE_DETAILS_REQ;
+	cmd_len = kvaser_usb_hydra_cmd_size(cmd);
    cmd->sw_detail_req.use_ext_cmd = 1;
    kvaser_usb_hydra_set_cmd_dest_he
    			(cmd, KVASER_USB_HYDRA_HE_ADDRESS_ILLEGAL);
@@ -1797,7 +1810,7 @@ static int kvaser_usb_hydra_get_software_details(struct kvaser_usb *dev)
    kvaser_usb_hydra_set_cmd_transid
    			(cmd, kvaser_usb_hydra_get_next_transid(dev));
-	err = kvaser_usb_send_cmd(dev, cmd, kvaser_usb_hydra_cmd_size(cmd));
+	err = kvaser_usb_send_cmd(dev, cmd, cmd_len);
    if (err)
    	goto end;
@@ -1913,6 +1926,7 @@ static int kvaser_usb_hydra_set_opt_mode(const struct kvaser_usb_net_priv *priv)
 {
    struct kvaser_usb *dev = priv->dev;
    struct kvaser_cmd *cmd;
+	size_t cmd_len;
    int err;
if ((priv->can.ctrlmode &
@@ -1928,6 +1942,7 @@ static int kvaser_usb_hydra_set_opt_mode(const struct kvaser_usb_net_priv *priv)
    	return -ENOMEM;
cmd->header.cmd_no = CMD_SET_DRIVERMODE_REQ;
+	cmd_len = kvaser_usb_hydra_cmd_size(cmd);
    kvaser_usb_hydra_set_cmd_dest_he
    	(cmd, dev->card_data.hydra.channel_to_he[priv->channel]);
    kvaser_usb_hydra_set_cmd_transid
@@ -1937,7 +1952,7 @@ static int kvaser_usb_hydra_set_opt_mode(const struct kvaser_usb_net_priv *priv)
    else
    	cmd->set_ctrlmode.mode = KVASER_USB_HYDRA_CTRLMODE_NORMAL;
-	err = kvaser_usb_send_cmd(dev, cmd, kvaser_usb_hydra_cmd_size(cmd));
+	err = kvaser_usb_send_cmd(dev, cmd, cmd_len);
    kfree(cmd);
return err;
-- 
2.39.0




    

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[PATCH 5.4 10/18] can: kvaser_usb: hydra: help gcc-13 to figure out cmd_len