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authorJuergen Gross <jgross@suse.com>2024-03-13 10:14:09 +0300
committerJuergen Gross <jgross@suse.com>2024-03-17 20:57:12 +0300
commitd277f9d82802223f242cd9b60c988cfdda1d6be0 (patch)
tree84e04e64e8dd68f71e65dc4d15d472d1d3cd7c80
parent51c23bd691c0f1fb95b29731c356c6fd69925d17 (diff)
downloadlinux-d277f9d82802223f242cd9b60c988cfdda1d6be0.tar.xz
xen/events: increment refcnt only if event channel is refcounted
In bind_evtchn_to_irq_chip() don't increment the refcnt of the event channel blindly. In case the event channel is NOT refcounted, issue a warning instead. Add an additional safety net by doing the refcnt increment only if the caller has specified IRQF_SHARED in the irqflags parameter. Fixes: 9e90e58c11b7 ("xen: evtchn: Allow shared registration of IRQ handers") Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Link: https://lore.kernel.org/r/20240313071409.25913-3-jgross@suse.com Signed-off-by: Juergen Gross <jgross@suse.com>
-rw-r--r--drivers/xen/events/events_base.c22
1 files changed, 13 insertions, 9 deletions
diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c
index 3b9f080109d7..27553673e46b 100644
--- a/drivers/xen/events/events_base.c
+++ b/drivers/xen/events/events_base.c
@@ -1190,7 +1190,7 @@ int xen_pirq_from_irq(unsigned irq)
EXPORT_SYMBOL_GPL(xen_pirq_from_irq);
static int bind_evtchn_to_irq_chip(evtchn_port_t evtchn, struct irq_chip *chip,
- struct xenbus_device *dev)
+ struct xenbus_device *dev, bool shared)
{
int ret = -ENOMEM;
struct irq_info *info;
@@ -1224,7 +1224,8 @@ static int bind_evtchn_to_irq_chip(evtchn_port_t evtchn, struct irq_chip *chip,
*/
bind_evtchn_to_cpu(info, 0, false);
} else if (!WARN_ON(info->type != IRQT_EVTCHN)) {
- info->refcnt++;
+ if (shared && !WARN_ON(info->refcnt < 0))
+ info->refcnt++;
}
ret = info->irq;
@@ -1237,13 +1238,13 @@ out:
int bind_evtchn_to_irq(evtchn_port_t evtchn)
{
- return bind_evtchn_to_irq_chip(evtchn, &xen_dynamic_chip, NULL);
+ return bind_evtchn_to_irq_chip(evtchn, &xen_dynamic_chip, NULL, false);
}
EXPORT_SYMBOL_GPL(bind_evtchn_to_irq);
int bind_evtchn_to_irq_lateeoi(evtchn_port_t evtchn)
{
- return bind_evtchn_to_irq_chip(evtchn, &xen_lateeoi_chip, NULL);
+ return bind_evtchn_to_irq_chip(evtchn, &xen_lateeoi_chip, NULL, false);
}
EXPORT_SYMBOL_GPL(bind_evtchn_to_irq_lateeoi);
@@ -1295,7 +1296,8 @@ static int bind_ipi_to_irq(unsigned int ipi, unsigned int cpu)
static int bind_interdomain_evtchn_to_irq_chip(struct xenbus_device *dev,
evtchn_port_t remote_port,
- struct irq_chip *chip)
+ struct irq_chip *chip,
+ bool shared)
{
struct evtchn_bind_interdomain bind_interdomain;
int err;
@@ -1307,14 +1309,14 @@ static int bind_interdomain_evtchn_to_irq_chip(struct xenbus_device *dev,
&bind_interdomain);
return err ? : bind_evtchn_to_irq_chip(bind_interdomain.local_port,
- chip, dev);
+ chip, dev, shared);
}
int bind_interdomain_evtchn_to_irq_lateeoi(struct xenbus_device *dev,
evtchn_port_t remote_port)
{
return bind_interdomain_evtchn_to_irq_chip(dev, remote_port,
- &xen_lateeoi_chip);
+ &xen_lateeoi_chip, false);
}
EXPORT_SYMBOL_GPL(bind_interdomain_evtchn_to_irq_lateeoi);
@@ -1430,7 +1432,8 @@ static int bind_evtchn_to_irqhandler_chip(evtchn_port_t evtchn,
{
int irq, retval;
- irq = bind_evtchn_to_irq_chip(evtchn, chip, NULL);
+ irq = bind_evtchn_to_irq_chip(evtchn, chip, NULL,
+ irqflags & IRQF_SHARED);
if (irq < 0)
return irq;
retval = request_irq(irq, handler, irqflags, devname, dev_id);
@@ -1471,7 +1474,8 @@ static int bind_interdomain_evtchn_to_irqhandler_chip(
{
int irq, retval;
- irq = bind_interdomain_evtchn_to_irq_chip(dev, remote_port, chip);
+ irq = bind_interdomain_evtchn_to_irq_chip(dev, remote_port, chip,
+ irqflags & IRQF_SHARED);
if (irq < 0)
return irq;