Since commit c330fb1ddc0a ("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.
This is upstream commit 0891fb39ba67bd7ae023ea0d367297ffff010781
Cc: stable@vger.kernel.org Fixes: c330fb1ddc0a ("XEN uses irqdesc::irq_data_common::handler_data to store a per interrupt XEN data pointer which contains XEN specific information.") Signed-off-by: Juergen Gross jgross@suse.com Tested-by: Stefan Bader stefan.bader@canonical.com Reviewed-by: Boris Ostrovsky boris.ostrovsky@oracle.com Link: https://lore.kernel.org/r/20200930091614.13660-1-jgross@suse.com --- drivers/xen/events/events_base.c | 29 +++++++++++++++++++++-------- 1 file changed, 21 insertions(+), 8 deletions(-)
diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c index 95e5a9300ff0..fdeeef2b9947 100644 --- a/drivers/xen/events/events_base.c +++ b/drivers/xen/events/events_base.c @@ -90,6 +90,8 @@ 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; @@ -154,7 +156,18 @@ int get_evtchn_to_irq(unsigned evtchn) /* Get info for IRQ */ struct irq_info *info_for_irq(unsigned irq) { - return irq_get_chip_data(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. */ @@ -375,7 +388,7 @@ 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); } @@ -424,14 +437,14 @@ 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);
@@ -601,7 +614,7 @@ EXPORT_SYMBOL_GPL(xen_irq_from_gsi); static void __unbind_from_irq(unsigned int irq) { int 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--; @@ -1105,7 +1118,7 @@ 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; @@ -1139,7 +1152,7 @@ int evtchn_make_refcounted(unsigned int evtchn) if (irq == -1) return -ENOENT;
- info = irq_get_chip_data(irq); + info = info_for_irq(irq);
if (!info) return -ENOENT; @@ -1167,7 +1180,7 @@ int evtchn_get(unsigned int evtchn) if (irq == -1) goto done;
- info = irq_get_chip_data(irq); + info = info_for_irq(irq);
if (!info) goto done;