From 9e8bc2dda5a7a8e2babc9975f4b11c9a6196e490 Mon Sep 17 00:00:00 2001 From: Chengfeng Ye Date: Tue, 26 Sep 2023 10:29:14 +0000 Subject: gpio: timberdale: Fix potential deadlock on &tgpio->lock As timbgpio_irq_enable()/timbgpio_irq_disable() callback could be executed under irq context, it could introduce double locks on &tgpio->lock if it preempts other execution units requiring the same locks. timbgpio_gpio_set() --> timbgpio_update_bit() --> spin_lock(&tgpio->lock) --> timbgpio_irq_disable() --> spin_lock_irqsave(&tgpio->lock) This flaw was found by an experimental static analysis tool I am developing for irq-related deadlock. To prevent the potential deadlock, the patch uses spin_lock_irqsave() on &tgpio->lock inside timbgpio_gpio_set() to prevent the possible deadlock scenario. Signed-off-by: Chengfeng Ye Reviewed-by: Andy Shevchenko Signed-off-by: Bartosz Golaszewski --- drivers/gpio/gpio-timberdale.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'drivers') diff --git a/drivers/gpio/gpio-timberdale.c b/drivers/gpio/gpio-timberdale.c index bbd9e9191199..fad979797486 100644 --- a/drivers/gpio/gpio-timberdale.c +++ b/drivers/gpio/gpio-timberdale.c @@ -43,9 +43,10 @@ static int timbgpio_update_bit(struct gpio_chip *gpio, unsigned index, unsigned offset, bool enabled) { struct timbgpio *tgpio = gpiochip_get_data(gpio); + unsigned long flags; u32 reg; - spin_lock(&tgpio->lock); + spin_lock_irqsave(&tgpio->lock, flags); reg = ioread32(tgpio->membase + offset); if (enabled) @@ -54,7 +55,7 @@ static int timbgpio_update_bit(struct gpio_chip *gpio, unsigned index, reg &= ~(1 << index); iowrite32(reg, tgpio->membase + offset); - spin_unlock(&tgpio->lock); + spin_unlock_irqrestore(&tgpio->lock, flags); return 0; } -- cgit v1.2.3 From 26d9e5640d2130ee16df7b1fb6a908f460ab004c Mon Sep 17 00:00:00 2001 From: Wenhua Lin Date: Thu, 21 Sep 2023 20:25:27 +0800 Subject: gpio: pmic-eic-sprd: Add can_sleep flag for PMIC EIC chip The drivers uses a mutex and I2C bus access in its PMIC EIC chip get implementation. This means these functions can sleep and the PMIC EIC chip should set the can_sleep property to true. This will ensure that a warning is printed when trying to get the value from a context that potentially can't sleep. Fixes: 348f3cde84ab ("gpio: Add Spreadtrum PMIC EIC driver support") Signed-off-by: Wenhua Lin Signed-off-by: Bartosz Golaszewski --- drivers/gpio/gpio-pmic-eic-sprd.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers') diff --git a/drivers/gpio/gpio-pmic-eic-sprd.c b/drivers/gpio/gpio-pmic-eic-sprd.c index 2b9b7be9b8fd..01c0fd0a9d8c 100644 --- a/drivers/gpio/gpio-pmic-eic-sprd.c +++ b/drivers/gpio/gpio-pmic-eic-sprd.c @@ -352,6 +352,7 @@ static int sprd_pmic_eic_probe(struct platform_device *pdev) pmic_eic->chip.set_config = sprd_pmic_eic_set_config; pmic_eic->chip.set = sprd_pmic_eic_set; pmic_eic->chip.get = sprd_pmic_eic_get; + pmic_eic->chip.can_sleep = true; irq = &pmic_eic->chip.irq; gpio_irq_chip_set_chip(irq, &pmic_eic_irq_chip); -- cgit v1.2.3