@@ -694,6 +694,9 @@ extern int irq_chip_request_resources_parent(struct irq_data *data);
extern void irq_chip_release_resources_parent(struct irq_data *data);
#endif
+/* Shut down the interrupt */
+extern void irq_shutdown(struct irq_desc *desc);
+
/* Handling of unhandled and spurious interrupts: */
extern void note_interrupt(struct irq_desc *desc, irqreturn_t action_ret);
@@ -88,7 +88,6 @@ extern int irq_activate(struct irq_desc *desc);
extern int irq_activate_and_startup(struct irq_desc *desc, bool resend);
extern int irq_startup(struct irq_desc *desc, bool resend, bool force);
-extern void irq_shutdown(struct irq_desc *desc);
extern void irq_shutdown_and_deactivate(struct irq_desc *desc);
extern void irq_enable(struct irq_desc *desc);
extern void irq_disable(struct irq_desc *desc);
@@ -41,6 +41,7 @@
#include <linux/objtool.h>
#include <linux/kmsg_dump.h>
#include <linux/irqdesc.h>
+#include <linux/irq.h>
#include <asm/page.h>
#include <asm/sections.h>
@@ -1084,7 +1085,7 @@ void machine_kexec_mask_interrupts(void)
int check_eoi = 1;
chip = irq_desc_get_chip(desc);
- if (!chip)
+ if (!chip || !irqd_is_started(&desc->irq_data))
continue;
if (IS_ENABLED(CONFIG_ARM64)) {
@@ -1098,10 +1099,6 @@ void machine_kexec_mask_interrupts(void)
if (check_eoi && chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data))
chip->irq_eoi(&desc->irq_data);
- if (chip->irq_mask)
- chip->irq_mask(&desc->irq_data);
-
- if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data))
- chip->irq_disable(&desc->irq_data);
+ irq_shutdown(desc);
}
}
During machine kexec, the function machine_kexec_mask_interrupts() is responsible for disabling or masking all interrupts. While the irq_disable hook ensures that an already-disabled IRQ is not disabled again, the current implementation unconditionally invokes the irq_mask() function for every interrupt descriptor, even when the interrupt is already masked. 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 surfaced after commit a8173820f441 ("gpio: gpiolib: Allow GPIO IRQs to lazy disable") introduced lazy disablement for GPIO IRQs. It replaced disable/enable hooks with mask/unmask hooks. Unlike the disable hook, the mask hook doesn't handle already-masked IRQs. When a GPIO-IRQ driver is unbound, the IRQ is released, triggering __irq_disable() and irq_state_set_masked(). A subsequent call to machine_kexec_mask_interrupts() re-invokes chip->irq_mask(). This results in a call chain, including gpiochip_irq_mask() and gpiochip_disable_irq(). Since FLAG_USED_AS_IRQ was cleared earlier, a warning occurs. This patch addresses the issue by: - Replacing the calls to irq_mask() and irq_disable() hooks with a simplified call to irq_shutdown(). - Checking if the interrupt is started (irqd_is_started) before calling the shutdown. As part of this change, the irq_shutdown() declaration was moved from kernel/irq/internals.h to include/linux/irq.h to make it accessible outside the kernel/irq/ directory, as the former can only be included within that directory. Signed-off-by: Eliav Farber <farbere@amazon.com> --- V4 -> V3: Add missing <linux/irq.h> include. include/linux/irq.h | 3 +++ kernel/irq/internals.h | 1 - kernel/kexec_core.c | 9 +++------ 3 files changed, 6 insertions(+), 7 deletions(-)