Commit 0891fb39 authored by Juergen Gross's avatar Juergen Gross
Browse files

xen/events: don't use chip_data for legacy IRQs 



Since commit c330fb1d ("XEN uses irqdesc::irq_data_common::handler_data to store a per interrupt XEN data pointer which contains XEN specific information.")
Xen is using the chip_data pointer for storing IRQ specific data. When
running as a HVM domain this can result in problems for legacy IRQs, as
those might use chip_data for their own purposes.

Use a local array for this purpose in case of legacy IRQs, avoiding the
double use.

Cc: stable@vger.kernel.org
Fixes: c330fb1d ("XEN uses irqdesc::irq_data_common::handler_data to store a per interrupt XEN data pointer which contains XEN specific information.")
Signed-off-by: default avatarJuergen Gross <jgross@suse.com>
Tested-by: default avatarStefan Bader <stefan.bader@canonical.com>
Reviewed-by: default avatarBoris Ostrovsky <boris.ostrovsky@oracle.com>
Link: https://lore.kernel.org/r/20200930091614.13660-1-jgross@suse.com


Signed-off-by: default avatarJuergen Gross <jgross@suse.com>
parent a1b8638b

drivers/xen/events/events_base.c

+21 −8
Original line number Diff line number Diff line
@@ -92,6 +92,8 @@ static bool (*pirq_needs_eoi)(unsigned irq); 
/* Xen will never allocate port zero for any purpose. */

#define VALID_EVTCHN(chn)	((chn) != 0)



static struct irq_info *legacy_info_ptrs[NR_IRQS_LEGACY];



static struct irq_chip xen_dynamic_chip;

static struct irq_chip xen_percpu_chip;

static struct irq_chip xen_pirq_chip;
@@ -156,9 +158,20 @@ int get_evtchn_to_irq(evtchn_port_t evtchn) 
/* Get info for IRQ */

struct irq_info *info_for_irq(unsigned irq)

{

	if (irq < nr_legacy_irqs())

		return legacy_info_ptrs[irq];

	else

		return irq_get_chip_data(irq);

}



static void set_info_for_irq(unsigned int irq, struct irq_info *info)

{

	if (irq < nr_legacy_irqs())

		legacy_info_ptrs[irq] = info;

	else

		irq_set_chip_data(irq, info);

}



/* Constructors for packed IRQ information. */

static int xen_irq_info_common_setup(struct irq_info *info,

				     unsigned irq,
@@ -377,7 +390,7 @@ static void xen_irq_init(unsigned irq) 
	info->type = IRQT_UNBOUND;

	info->refcnt = -1;



	irq_set_chip_data(irq, info);

	set_info_for_irq(irq, info);



	list_add_tail(&info->list, &xen_irq_list_head);

}
@@ -426,14 +439,14 @@ static int __must_check xen_allocate_irq_gsi(unsigned gsi) 


static void xen_free_irq(unsigned irq)

{

	struct irq_info *info = irq_get_chip_data(irq);

	struct irq_info *info = info_for_irq(irq);



	if (WARN_ON(!info))

		return;



	list_del(&info->list);



	irq_set_chip_data(irq, NULL);

	set_info_for_irq(irq, NULL);



	WARN_ON(info->refcnt > 0);
@@ -603,7 +616,7 @@ EXPORT_SYMBOL_GPL(xen_irq_from_gsi); 
static void __unbind_from_irq(unsigned int irq)

{

	evtchn_port_t evtchn = evtchn_from_irq(irq);

	struct irq_info *info = irq_get_chip_data(irq);

	struct irq_info *info = info_for_irq(irq);



	if (info->refcnt > 0) {

		info->refcnt--;
@@ -1108,7 +1121,7 @@ int bind_ipi_to_irqhandler(enum ipi_vector ipi, 


void unbind_from_irqhandler(unsigned int irq, void *dev_id)

{

	struct irq_info *info = irq_get_chip_data(irq);

	struct irq_info *info = info_for_irq(irq);



	if (WARN_ON(!info))

		return;
@@ -1142,7 +1155,7 @@ int evtchn_make_refcounted(evtchn_port_t evtchn) 
	if (irq == -1)

		return -ENOENT;



	info = irq_get_chip_data(irq);

	info = info_for_irq(irq);



	if (!info)

		return -ENOENT;
@@ -1170,7 +1183,7 @@ int evtchn_get(evtchn_port_t evtchn) 
	if (irq == -1)

		goto done;



	info = irq_get_chip_data(irq);

	info = info_for_irq(irq);



	if (!info)

		goto done;

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