gpio: sim: set a limit on the number of GPIOs

With the removal of ARCH_NR_GPIOS in commit 7b61212f2a07 ("gpiolib: Get
rid of ARCH_NR_GPIOS") the gpiolib core no longer sanitizes the number
of GPIOs for us. This causes the gpio-sim selftests to now fail when
setting the number of GPIOs to 99999 and expecting the probe() to fail.

Set a sane limit of 1024 on the number of simulated GPIOs and bail out
of probe if it's exceeded.

Reported-by: kernel test robot <oliver.sang@intel.com>
Link: https://lore.kernel.org/oe-lkp/202212112236.756f5db9-oliver.sang@intel.com
Fixes: 7b61212f2a07 ("gpiolib: Get rid of ARCH_NR_GPIOS")
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

diff --git a/drivers/gpio/gpio-sim.c b/drivers/gpio/gpio-sim.c
index 1020c2feb24964303c279fa352af7839991a8775..60514bc5454f8ceb258e0647910b91fd1642cd8e 100644 (file)
--- a/drivers/gpio/gpio-sim.c
+++ b/drivers/gpio/gpio-sim.c
@@ -31,6 +31,7 @@
 
 #include "gpiolib.h"
 
+#define GPIO_SIM_NGPIO_MAX     1024
 #define GPIO_SIM_PROP_MAX      4 /* Max 3 properties + sentinel. */
 #define GPIO_SIM_NUM_ATTRS     3 /* value, pull and sentinel */
 
@@ -371,6 +372,9 @@ static int gpio_sim_add_bank(struct fwnode_handle *swnode, struct device *dev)
        if (ret)
                return ret;
 
+       if (num_lines > GPIO_SIM_NGPIO_MAX)
+               return -ERANGE;
+
        ret = fwnode_property_read_string(swnode, "gpio-sim,label", &label);
        if (ret) {
                label = devm_kasprintf(dev, GFP_KERNEL, "%s-%s",