genirq: Prevent resend to interrupts marked IRQ_NESTED_THREAD (51871c2b) · Commits · e / devices / android_kernel_xiaomi_markw

[ Upstream commit 75a06189fc508a2acf470b0b12710362ffb2c4b1 ] The resend mechanism happily calls the interrupt handler of interrupts which are marked IRQ_NESTED_THREAD from softirq context. This can result in crashes because the interrupt handler is not the proper way to invoke the device handlers. They must be invoked via handle_nested_irq. Prevent the resend even if the interrupt has no valid parent irq set. Its better to have a lost interrupt than a crashing machine. Reported-by:

Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by:

Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Signed-off-by:

Sasha Levin <sasha.levin@oracle.com>

kernel/irq/resend.c

+13 −5

Original line number	Diff line number	Diff line
		@@ -75,13 +75,21 @@ void check_irq_resend(struct irq_desc *desc, unsigned int irq)
		!desc->irq_data.chip->irq_retrigger(&desc->irq_data)) {
		#ifdef CONFIG_HARDIRQS_SW_RESEND
		/*
		* If the interrupt has a parent irq and runs
		* in the thread context of the parent irq,
		* retrigger the parent.
		* If the interrupt is running in the thread
		* context of the parent irq we need to be
		* careful, because we cannot trigger it
		* directly.
		*/
		if (desc->parent_irq &&
		irq_settings_is_nested_thread(desc))
		if (irq_settings_is_nested_thread(desc)) {
		/*
		* If the parent_irq is valid, we
		* retrigger the parent, otherwise we
		* do nothing.
		*/
		if (!desc->parent_irq)
		return;
		irq = desc->parent_irq;
		}
		/* Set it pending and activate the softirq: */
		set_bit(irq, irqs_resend);
		tasklet_schedule(&resend_tasklet);