| Message ID | 20241126050509.4426-1-farbere@amazon.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | arm64: kexec: Check if IRQ is already masked before masking | expand |
diff --git a/arch/arm64/kernel/machine_kexec.c b/arch/arm64/kernel/machine_kexec.c index 82e2203d86a3..6f56ec676844 100644 --- a/arch/arm64/kernel/machine_kexec.c +++ b/arch/arm64/kernel/machine_kexec.c @@ -230,7 +230,7 @@ static void machine_kexec_mask_interrupts(void) chip->irq_eoi) chip->irq_eoi(&desc->irq_data); - if (chip->irq_mask) + if (chip->irq_mask && !irqd_irq_masked(&desc->irq_data)) chip->irq_mask(&desc->irq_data); if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data))
During machine kexec, the function machine_kexec_mask_interrupts() is responsible for masking all interrupts. However, the current implementation unconditionally calls the irq_mask() function for each interrupt descriptor, even if the interrupt is already masked. This commit adds a check to verify if the interrupt is not already masked before calling the irq_mask() function. This change avoids redundant masking operations and potential issues that might arise from attempting to mask an already masked interrupt. A specific issue was observed in the crash kernel flow after unbinding a device (prior to kexec) that used a GPIO as an IRQ source. The warning was triggered by the gpiochip_disable_irq() function, which attempted to clear the FLAG_IRQ_IS_ENABLED flag when FLAG_USED_AS_IRQ was not set: ``` void gpiochip_disable_irq(struct gpio_chip *gc, unsigned int offset) { struct gpio_desc *desc = gpiochip_get_desc(gc, offset); if (!IS_ERR(desc) && !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags))) clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags); } ``` This issue began after commit a8173820f441 ("gpio: gpiolib: Allow GPIO IRQs to lazy disable"), which replaced IRQ disable/enable hooks with mask/unmask hooks in some cases. The irq_disable hook was protected against disabling an already disabled IRQ, but the irq_mask hook in machine_kexec_mask_interrupts() was not. When a driver that uses a GPIO-irq is unbound, the corresponding IRQ is released, invoking __irq_disable() and irq_state_set_masked(). Subsequently, machine_kexec_mask_interrupts() attempts to call the chip->irq_mask() function again. This invokes gpiochip_irq_mask() and gpiochip_disable_irq(), and since FLAG_USED_AS_IRQ has already been cleared, this results in a warning being printed. Signed-off-by: Eliav Farber <farbere@amazon.com> --- arch/arm64/kernel/machine_kexec.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)