From dc87f6dd058a648cd2a35e4aa04592dccdc9f0c2 Mon Sep 17 00:00:00 2001 From: Adam Ford Date: Sat, 11 Apr 2020 20:33:52 -0500 Subject: gpio: pca953x: Fix pca953x_gpio_set_config pca953x_gpio_set_config is setup to support pull-up/down bias. Currently the driver uses a variable called 'config' to determine which options to use. Unfortunately, this is incorrect. This patch uses function pinconf_to_config_param(config), which converts this 'config' parameter back to pinconfig to determine which option to use. Fixes: 15add06841a3 ("gpio: pca953x: add ->set_config implementation") Signed-off-by: Adam Ford Signed-off-by: Bartosz Golaszewski --- drivers/gpio/gpio-pca953x.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c index 5638b4e5355f..4269ea9a817e 100644 --- a/drivers/gpio/gpio-pca953x.c +++ b/drivers/gpio/gpio-pca953x.c @@ -531,7 +531,7 @@ static int pca953x_gpio_set_config(struct gpio_chip *gc, unsigned int offset, { struct pca953x_chip *chip = gpiochip_get_data(gc); - switch (config) { + switch (pinconf_to_config_param(config)) { case PIN_CONFIG_BIAS_PULL_UP: case PIN_CONFIG_BIAS_PULL_DOWN: return pca953x_gpio_set_pull_up_down(chip, offset, config); -- cgit v1.2.3 From 4e1541593017d76cfa04bd666de8e4dbcfe3105d Mon Sep 17 00:00:00 2001 From: Bartosz Golaszewski Date: Wed, 15 Apr 2020 10:23:59 +0200 Subject: gpiolib: improve the robustness of watch/unwatch ioctl() This makes the new ioctl() a bit more robust - we now check if a line is already being watched and return -EBUSY if the user-space tries to start watching it again. Same for unwatch - return -EBUSY if user-space tries to unwatch a line that's not being watched. Fixes: 51c1064e82e7 ("gpiolib: add new ioctl() for monitoring changes in line info") Signed-off-by: Bartosz Golaszewski Reviewed-by: Linus Walleij --- drivers/gpio/gpiolib.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 40f2d7f69be2..29f6abe84d2e 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -1227,6 +1227,7 @@ static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) void __user *ip = (void __user *)arg; struct gpio_desc *desc; __u32 offset; + int hwgpio; /* We fail any subsequent ioctl():s when the chip is gone */ if (!gc) @@ -1259,13 +1260,19 @@ static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) if (IS_ERR(desc)) return PTR_ERR(desc); + hwgpio = gpio_chip_hwgpio(desc); + + if (cmd == GPIO_GET_LINEINFO_WATCH_IOCTL && + test_bit(hwgpio, priv->watched_lines)) + return -EBUSY; + gpio_desc_to_lineinfo(desc, &lineinfo); if (copy_to_user(ip, &lineinfo, sizeof(lineinfo))) return -EFAULT; if (cmd == GPIO_GET_LINEINFO_WATCH_IOCTL) - set_bit(gpio_chip_hwgpio(desc), priv->watched_lines); + set_bit(hwgpio, priv->watched_lines); return 0; } else if (cmd == GPIO_GET_LINEHANDLE_IOCTL) { @@ -1280,7 +1287,12 @@ static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) if (IS_ERR(desc)) return PTR_ERR(desc); - clear_bit(gpio_chip_hwgpio(desc), priv->watched_lines); + hwgpio = gpio_chip_hwgpio(desc); + + if (!test_bit(hwgpio, priv->watched_lines)) + return -EBUSY; + + clear_bit(hwgpio, priv->watched_lines); return 0; } return -EINVAL; -- cgit v1.2.3 From 6409d049ce28bef35e13dfb8699fc7ee27469ba1 Mon Sep 17 00:00:00 2001 From: Bartosz Golaszewski Date: Fri, 17 Apr 2020 09:01:51 +0200 Subject: gpiolib: don't call sleeping functions with a spinlock taken We must not call pinctrl_gpio_can_use_line() with the gpio_lock taken as it takes a mutex internally. Let's move the call before taking the spinlock and store the return value. This isn't perfect - there's a moment between calling pinctrl_gpio_can_use_line() and taking the spinlock where the situation can change but it isn't a regression either: previously this part wasn't protected at all and it only affects the information user-space is seeing. Reported-by: Geert Uytterhoeven Fixes: d2ac25798208 ("gpiolib: provide a dedicated function for setting lineinfo") Signed-off-by: Bartosz Golaszewski Acked-by: Linus Walleij --- drivers/gpio/gpiolib.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 29f6abe84d2e..bf9732ab7f91 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -1158,8 +1158,19 @@ static void gpio_desc_to_lineinfo(struct gpio_desc *desc, struct gpioline_info *info) { struct gpio_chip *gc = desc->gdev->chip; + bool ok_for_pinctrl; unsigned long flags; + /* + * This function takes a mutex so we must check this before taking + * the spinlock. + * + * FIXME: find a non-racy way to retrieve this information. Maybe a + * lock common to both frameworks? + */ + ok_for_pinctrl = + pinctrl_gpio_can_use_line(gc->base + info->line_offset); + spin_lock_irqsave(&gpio_lock, flags); if (desc->name) { @@ -1186,7 +1197,7 @@ static void gpio_desc_to_lineinfo(struct gpio_desc *desc, test_bit(FLAG_USED_AS_IRQ, &desc->flags) || test_bit(FLAG_EXPORT, &desc->flags) || test_bit(FLAG_SYSFS, &desc->flags) || - !pinctrl_gpio_can_use_line(gc->base + info->line_offset)) + !ok_for_pinctrl) info->flags |= GPIOLINE_FLAG_KERNEL; if (test_bit(FLAG_IS_OUT, &desc->flags)) info->flags |= GPIOLINE_FLAG_IS_OUT; -- cgit v1.2.3