From 5224a733d3bd4d0db3548712047506c50487085e Mon Sep 17 00:00:00 2001 From: Ian Campbell Date: Fri, 24 Jan 2014 14:23:07 +0000 Subject: [PATCH] xen: arm: correct use of find_next_bit find_next_bit takes a "const unsigned long *" but forcing a cast of an "uint32_t *" throws away the alignment constraints and ends up causing an alignment fault on arm64 if the input happened to be 4 but not 8 byte aligned. Instead of casting use a temporary variable of the right type. I've had a look around for similar constructs and the only thing I found was maintenance_interrupt which cases a uint64_t down to an unsigned long, which although perhaps not best advised is safe I think. This was observed with the AArch64 Linaro toolchain 2013.12 but I think that is just coincidental due to subtle changes to the stack layout etc. Reported-by: Fu Wei Signed-off-by: Ian Campbell Acked-by: Julien Grall --- xen/arch/arm/vgic.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/xen/arch/arm/vgic.c b/xen/arch/arm/vgic.c index 90e97074ee..553411d3e1 100644 --- a/xen/arch/arm/vgic.c +++ b/xen/arch/arm/vgic.c @@ -362,11 +362,12 @@ read_as_zero: static void vgic_disable_irqs(struct vcpu *v, uint32_t r, int n) { + const unsigned long mask = r; struct pending_irq *p; unsigned int irq; int i = 0; - while ( (i = find_next_bit((const long unsigned int *) &r, 32, i)) < 32 ) { + while ( (i = find_next_bit(&mask, 32, i)) < 32 ) { irq = i + (32 * n); p = irq_to_pending(v, irq); clear_bit(GIC_IRQ_GUEST_ENABLED, &p->status); @@ -379,11 +380,12 @@ static void vgic_disable_irqs(struct vcpu *v, uint32_t r, int n) static void vgic_enable_irqs(struct vcpu *v, uint32_t r, int n) { + const unsigned long mask = r; struct pending_irq *p; unsigned int irq; int i = 0; - while ( (i = find_next_bit((const long unsigned int *) &r, 32, i)) < 32 ) { + while ( (i = find_next_bit(&mask, 32, i)) < 32 ) { irq = i + (32 * n); p = irq_to_pending(v, irq); set_bit(GIC_IRQ_GUEST_ENABLED, &p->status); -- 2.30.2