Commit 35eb2ef5 authored by Florian Fainelli's avatar Florian Fainelli Committed by Marc Zyngier
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irqchip/irq-bcm7038-l1: Gate use of CPU logical map to MIPS 



The use of the cpu_logical_map[] array is only relevant for MIPS based
platform where this driver is used as a first level interrupt controller
and contains multiple register groups to map with an associated CPU.

On ARM/ARM64 based systems this interrupt controller is present and used
as a second level interrupt controller hanging off the ARM GIC. That
copy of the interrupt controller contains a single group, resulting in
the intc->cpus[] array to be of size 1.

Things happened to work in that case because we install that interrupt
controller as a chained handler which does not allow it to be affine to
any CPU but the boot CPU which happens to be 0, therefore we never
de-reference past intc->cpus[] but with the current code in place, we do
leave a chance of de-referencing the array past its bounds.

Signed-off-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211020184859.2705451-5-f.fainelli@gmail.com
parent 4b551920

drivers/irqchip/irq-bcm7038-l1.c

+3 −6
Original line number Diff line number Diff line
@@ -28,9 +28,6 @@ 
#include <linux/irqchip.h>

#include <linux/irqchip/chained_irq.h>

#include <linux/syscore_ops.h>

#ifdef CONFIG_ARM

#include <asm/smp_plat.h>

#endif



#define IRQS_PER_WORD		32

#define REG_BYTES_PER_IRQ_WORD	(sizeof(u32) * 4)
@@ -127,7 +124,7 @@ static void bcm7038_l1_irq_handle(struct irq_desc *desc) 
	struct irq_chip *chip = irq_desc_get_chip(desc);

	unsigned int idx;



#ifdef CONFIG_SMP

#if defined(CONFIG_SMP) && defined(CONFIG_MIPS)

	cpu = intc->cpus[cpu_logical_map(smp_processor_id())];

#else

	cpu = intc->cpus[0];
@@ -301,7 +298,7 @@ static int bcm7038_l1_suspend(void) 
	u32 val;



	/* Wakeup interrupt should only come from the boot cpu */

#ifdef CONFIG_SMP

#if defined(CONFIG_SMP) && defined(CONFIG_MIPS)

	boot_cpu = cpu_logical_map(0);

#else

	boot_cpu = 0;
@@ -325,7 +322,7 @@ static void bcm7038_l1_resume(void) 
	struct bcm7038_l1_chip *intc;

	int boot_cpu, word;



#ifdef CONFIG_SMP

#if defined(CONFIG_SMP) && defined(CONFIG_MIPS)

	boot_cpu = cpu_logical_map(0);

#else

	boot_cpu = 0;