diff options
| author | Linus Walleij | 2020-03-06 14:23:26 +0100 |
|---|---|---|
| committer | Linus Walleij | 2020-03-11 15:55:03 +0100 |
| commit | 8959b304c7062889b1276092cc8590dc1ba98f65 (patch) | |
| tree | 0149e54d643bf600e2df45205ba1980063c1702b /drivers/gpio | |
| parent | f8788d86ab28f61f7b46eb6be375f8a726783636 (diff) | |
gpiolib: Fix irq_disable() semantics
The implementation if .irq_disable() which kicks in between
the gpiolib and the driver is not properly mimicking the
expected semantics of the irqchip core: the irqchip will
call .irq_disable() if that exists, else it will call
mask_irq() which first checks if .irq_mask() is defined
before calling it.
Since we are calling it unconditionally, we get this bug
from drivers/pinctrl/qcom/pinctrl-ssbi-gpio.c, as it only
defines .irq_mask_ack and not .irq_mask:
Unable to handle kernel NULL pointer dereference at virtual address 00000000
pgd = (ptrval)
(...)
PC is at 0x0
LR is at gpiochip_irq_disable+0x20/0x30
Fix this by only calling .irq_mask() if it exists.
Cc: Brian Masney <masneyb@onstation.org>
Cc: Hans Verkuil <hans.verkuil@cisco.com>
Cc: stable@vger.kernel.org
Reviewed-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Fixes: 461c1a7d4733 ("gpiolib: override irq_enable/disable")
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20200306132326.1329640-1-linus.walleij@linaro.org
Diffstat (limited to 'drivers/gpio')
| -rw-r--r-- | drivers/gpio/gpiolib.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 4d0106ceeba7..00fb91feba70 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -2306,9 +2306,16 @@ static void gpiochip_irq_disable(struct irq_data *d) { struct gpio_chip *chip = irq_data_get_irq_chip_data(d); + /* + * Since we override .irq_disable() we need to mimic the + * behaviour of __irq_disable() in irq/chip.c. + * First call .irq_disable() if it exists, else mimic the + * behaviour of mask_irq() which calls .irq_mask() if + * it exists. + */ if (chip->irq.irq_disable) chip->irq.irq_disable(d); - else + else if (chip->irq.chip->irq_mask) chip->irq.chip->irq_mask(d); gpiochip_disable_irq(chip, d->hwirq); } |