Hi Dan,
On Tue, Oct 05, 2021 at 12:25:21PM +0300, Dan Carpenter wrote:
> Hello Media devs,
>
> The patch 7641b0442195: "media: i2c: Copy mt9t112 soc_camera sensor
> driver" from Mar 12, 2018, leads to the following Smatch static
> checker warning:
That commit is from me, but I just copied the code as (ugly) as it
was I didn't even have the hw to test it so I preferred not to touch
it
>
> drivers/media/i2c/mt9t112.c:176 __mt9t112_reg_read()
> warn: not copying enough bytes for '&ret' (4 vs 2 bytes)
>
> drivers/media/i2c/mt9t112.c
> 150 static int __mt9t112_reg_read(const struct i2c_client *client, u16 command)
> 151 {
> 152 struct i2c_msg msg[2];
> 153 u8 buf[2];
> 154 int ret;
> 155
> 156 command = swab16(command);
> ^^^^^^^^^^^^^^^
> This driver won't work on big endian systems
>
> 157
> 158 msg[0].addr = client->addr;
> 159 msg[0].flags = 0;
> 160 msg[0].len = 2;
> 161 msg[0].buf = (u8 *)&command;
> 162
> 163 msg[1].addr = client->addr;
> 164 msg[1].flags = I2C_M_RD;
> 165 msg[1].len = 2;
> 166 msg[1].buf = buf;
> 167
> 168 /*
> 169 * If return value of this function is < 0, it means error, else,
> 170 * below 16bit is valid data.
> 171 */
> 172 ret = i2c_transfer(client->adapter, msg, 2);
> 173 if (ret < 0)
> 174 return ret;
> 175
> --> 176 memcpy(&ret, buf, 2);
> ^^^^
> And this is ugly as all heck. I would have fixed it but there were
> so many other endian bugs and I can't test it.
Is this an endianess issue or just a complaint about the difference in
size between the number of copied bytes and the destination ?
Thanks
j
>
> 177
> 178 return swab16(ret);
> 179 }
>
> regards,
> dan carpenter
