Hi Dan,
Thanks for the report, I'm fixing up the patch (it uncovered another
issue).
On 20/02/2018 at 12:00:25 +0300, Dan Carpenter wrote:
> Hello Alexandre Belloni,
>
> This is a semi-automatic email about new static checker warnings.
>
> The patch ce0e0076da3e: "rtc: m48t59: use generic nvmem" from Feb 12,
> 2018, leads to the following Smatch complaint:
>
> drivers/rtc/rtc-m48t59.c:409 m48t59_rtc_probe()
> warn: variable dereferenced before check 'pdata' (see line 391)
>
> drivers/rtc/rtc-m48t59.c
> 390 .stride = 1,
> 391 .size = pdata->offset,
> ^^^^^^^^^^^^^
> New dereference.
>
> 392 .reg_read = m48t59_nvram_read,
> 393 .reg_write = m48t59_nvram_write,
> 394 .priv = pdev,
> 395 };
> 396
> 397 /* This chip could be memory-mapped or I/O-mapped */
> 398 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> 399 if (!res) {
> 400 res = platform_get_resource(pdev, IORESOURCE_IO, 0);
> 401 if (!res)
> 402 return -EINVAL;
> 403 }
> 404
> 405 if (res->flags & IORESOURCE_IO) {
> 406 /* If we are I/O-mapped, the platform should provide
> 407 * the operations accessing chip registers.
> 408 */
> 409 if (!pdata || !pdata->write_byte || !pdata->read_byte)
> ^^^^^
> The existing code assumed "pdata" could be NULL.
>
> 410 return -EINVAL;
> 411 } else if (res->flags & IORESOURCE_MEM) {
>
> regards,
> dan carpenter
--
Alexandre Belloni, Bootlin (formerly Free Electrons)
Embedded Linux and Kernel engineering
https://bootlin.com
