[PATCH 1/4] gpio: Remove VLA from gpiolib

[Laura Abbott]

The new challenge is to remove VLAs from the kernel
(see https://lkml.org/lkml/2018/3/7/621)

This patch replaces several VLAs with an appropriate call to
kmalloc_array.

Signed-off-by: Laura Abbott <labb...@redhat.com>
---
 drivers/gpio/gpiolib.c | 55 +++++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 48 insertions(+), 7 deletions(-)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index d66de67ef307..124727c74931 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -2662,16 +2662,33 @@ int gpiod_get_array_value_complex(bool raw, bool 
can_sleep,
 
        while (i < array_size) {
                struct gpio_chip *chip = desc_array[i]->gdev->chip;
-               unsigned long mask[BITS_TO_LONGS(chip->ngpio)];
-               unsigned long bits[BITS_TO_LONGS(chip->ngpio)];
+               unsigned long *mask;
+               unsigned long *bits;
                int first, j, ret;
 
+               mask = kmalloc_array(BITS_TO_LONGS(chip->ngpio),
+                               sizeof(*mask),
+                               can_sleep ? GFP_KERNEL : GFP_ATOMIC);
+
+               if (!mask)
+                       return -ENOMEM;
+
+               bits = kmalloc_array(BITS_TO_LONGS(chip->ngpio),
+                               sizeof(*bits),
+                               can_sleep ? GFP_KERNEL : GFP_ATOMIC);
+
+               if (!bits) {
+                       kfree(mask);
+                       return -ENOMEM;
+               }
+
+
                if (!can_sleep)
                        WARN_ON(chip->can_sleep);
 
                /* collect all inputs belonging to the same chip */
                first = i;
-               memset(mask, 0, sizeof(mask));
+               memset(mask, 0, sizeof(*mask));
                do {
                        const struct gpio_desc *desc = desc_array[i];
                        int hwgpio = gpio_chip_hwgpio(desc);
@@ -2682,8 +2699,11 @@ int gpiod_get_array_value_complex(bool raw, bool 
can_sleep,
                         (desc_array[i]->gdev->chip == chip));
 
                ret = gpio_chip_get_multiple(chip, mask, bits);
-               if (ret)
+               if (ret) {
+                       kfree(bits);
+                       kfree(mask);
                        return ret;
+               }
 
                for (j = first; j < i; j++) {
                        const struct gpio_desc *desc = desc_array[j];
@@ -2695,6 +2715,8 @@ int gpiod_get_array_value_complex(bool raw, bool 
can_sleep,
                        value_array[j] = value;
                        trace_gpio_value(desc_to_gpio(desc), 1, value);
                }
+               kfree(bits);
+               kfree(mask);
        }
        return 0;
 }
@@ -2887,14 +2909,30 @@ void gpiod_set_array_value_complex(bool raw, bool 
can_sleep,
 
        while (i < array_size) {
                struct gpio_chip *chip = desc_array[i]->gdev->chip;
-               unsigned long mask[BITS_TO_LONGS(chip->ngpio)];
-               unsigned long bits[BITS_TO_LONGS(chip->ngpio)];
+               unsigned long *mask;
+               unsigned long *bits;
                int count = 0;
 
+               mask = kmalloc_array(BITS_TO_LONGS(chip->ngpio),
+                               sizeof(*mask),
+                               can_sleep ? GFP_KERNEL : GFP_ATOMIC);
+
+               if (!mask)
+                       return;
+
+               bits = kmalloc_array(BITS_TO_LONGS(chip->ngpio),
+                               sizeof(*bits),
+                               can_sleep ? GFP_KERNEL : GFP_ATOMIC);
+
+               if (!bits) {
+                       kfree(mask);
+                       return;
+               }
+
                if (!can_sleep)
                        WARN_ON(chip->can_sleep);
 
-               memset(mask, 0, sizeof(mask));
+               memset(mask, 0, sizeof(*mask));
                do {
                        struct gpio_desc *desc = desc_array[i];
                        int hwgpio = gpio_chip_hwgpio(desc);
@@ -2925,6 +2963,9 @@ void gpiod_set_array_value_complex(bool raw, bool 
can_sleep,
                /* push collected bits to outputs */
                if (count != 0)
                        gpio_chip_set_multiple(chip, mask, bits);
+
+               kfree(mask);
+               kfree(bits);
        }
 }
 
-- 
2.14.3