target/linux/realtek/patches-5.10/316-otto-gpio-uniprocessor-irq-mask.patch

   1 From bde6311569ef25a00c3beaeabfd6b78b19651872 Mon Sep 17 00:00:00 2001
   2 From: Sander Vanheule <sander@svanheule.net>
   3 Date: Sun, 29 May 2022 19:38:09 +0200
   4 Subject: [PATCH] realtek: don't unmask non-maskable GPIO IRQs
   5
   6 On uniprocessor builds, for_each_cpu(cpu, mask) will assume 'mask'
   7 always contains exactly one CPU, and ignore the actual mask contents.
   8 This causes the loop to run, even when it shouldn't on an empty mask,
   9 and tries to access an uninitialised pointer.
  10
  11 Fix this by wrapping the loop in a cpumask_empty() check, to ensure it
  12 will not run on uniprocessor builds if the CPU mask is empty.
  13
  14 Fixes: af6cd37f42f3 ("realtek: replace RTL93xx GPIO patches")
  15 Reported-by: INAGAKI Hiroshi <musashino.open@gmail.com>
  16 Reported-by: Robert Marko <robimarko@gmail.com>
  17 Tested-by: Robert Marko <robimarko@gmail.com>
  18 Submitted-by: Sander Vanheule <sander@svanheule.net>
  19 ---
  20  drivers/gpio/gpio-realtek-otto.c              | 9 +++++++++++--
  21  1 file changed, 11 insertions(+), 2 deletions(-)
  22
  23 --- a/drivers/gpio/gpio-realtek-otto.c
  24 +++ b/drivers/gpio/gpio-realtek-otto.c
  25 @@ -304,6 +304,7 @@ static int realtek_gpio_irq_set_affinity
  26  static int realtek_gpio_irq_init(struct gpio_chip *gc)
  27  {
  28         struct realtek_gpio_ctrl *ctrl = gpiochip_get_data(gc);
  29 +       void __iomem *irq_cpu_mask;
  30         unsigned int port;
  31         int cpu;
  32
  33 @@ -311,8 +312,16 @@ static int realtek_gpio_irq_init(struct
  34                 realtek_gpio_write_imr(ctrl, port, 0, 0);
  35                 realtek_gpio_clear_isr(ctrl, port, GENMASK(7, 0));
  36
  37 -               for_each_cpu(cpu, &ctrl->cpu_irq_maskable)
  38 -                       iowrite8(GENMASK(7, 0), realtek_gpio_irq_cpu_mask(ctrl, port, cpu));
  39 +               /*
  40 +                * Uniprocessor builds assume a mask always contains one CPU,
  41 +                * so only start the loop if we have at least one maskable CPU.
  42 +                */
  43 +               if(!cpumask_empty(&ctrl->cpu_irq_maskable)) {
  44 +                       for_each_cpu(cpu, &ctrl->cpu_irq_maskable) {
  45 +                               irq_cpu_mask = realtek_gpio_irq_cpu_mask(ctrl, port, cpu);
  46 +                               iowrite8(GENMASK(7, 0), irq_cpu_mask);
  47 +                       }
  48 +               }
  49         }
  50
  51         return 0;