pinctrl: abx500: fix abx500_gpio_dbg_show_one() to show pull up/down

[ This is not very new, sorry. -dan ]

Hello Patrice Chotard,

This is a semi-automatic email about new static checker warnings.

The patch d2752ae54d4a: "pinctrl: abx500: fix abx500_gpio_dbg_show_one() to show pull up/down" from May 24, 2013, leads to the following Smatch complaint:

drivers/pinctrl/nomadik/pinctrl-abx500.c:623 abx500_gpio_dbg_show_one()
warn: variable dereferenced before check 'pctldev' (see line 573)

drivers/pinctrl/nomadik/pinctrl-abx500.c
572 {

   573		struct abx500_pinctrl *pct = pinctrl_dev_get_drvdata(pctldev);
                                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Patch adds a new unchecked dereference.

574 const char *label = gpiochip_is_requested(chip, offset - 1);
575 u8 gpio_offset = offset - 1;
576 int mode = -1;
577 bool is_out;
578 bool pd;
579 enum abx500_gpio_pull_updown pud = 0;
580 int ret;
581
582 const char *modes[] = {
583 [ABX500_DEFAULT] = "default",
584 [ABX500_ALT_A] = "altA",
585 [ABX500_ALT_B] = "altB",
586 [ABX500_ALT_C] = "altC",
587 };
588
589 const char *pull_up_down[] = {
590 [ABX500_GPIO_PULL_DOWN] = "pull down",
591 [ABX500_GPIO_PULL_NONE] = "pull none",
592 [ABX500_GPIO_PULL_NONE + 1] = "pull none",
593 [ABX500_GPIO_PULL_UP] = "pull up",
594 };
595
596 ret = abx500_gpio_get_bit(chip, AB8500_GPIO_DIR1_REG,
597 gpio_offset, &is_out);
598 if (ret < 0)
599 goto out;
600
601 seq_printf(s, " gpio-%-3d (%-20.20s) %-3s",
602 gpio, label ?: "(none)",
603 is_out ? "out" : "in ");
604
605 if (!is_out) {
606 if (abx500_pullud_supported(chip, offset)) {
607 ret = abx500_get_pull_updown(pct, offset, &pud);
608 if (ret < 0)
609 goto out;
610
611 seq_printf(s, " %-9s", pull_up_down[pud]);
612 } else {
613 ret = abx500_gpio_get_bit(chip, AB8500_GPIO_PUD1_REG,
614 gpio_offset, &pd);
615 if (ret < 0)
616 goto out;
617
618 seq_printf(s, " %-9s", pull_up_down[pd]);
619 }
620 } else
621 seq_printf(s, " %-9s", chip->get(chip, offset) ? "hi" : "lo");
622
623 if (pctldev)

                    ^^^^^^^

The existing code assumes "pctldev" can be NULL.

   624			mode = abx500_get_mode(pctldev, chip, offset);
   625	

regards,
dan carpenter