xen/irq: Alter the locking to use a mutex instead of a spinlock.
When we allocate/change the IRQ informations, we do not
need to use spinlocks. We can use a mutex (which is
what the generic IRQ code does for allocations/changes).
Fixes a slew of:
BUG: sleeping function called from invalid context at /linux/kernel/mutex.c:271
in_atomic(): 1, irqs_disabled(): 0, pid: 3216, name: xenstored
2 locks held by xenstored/3216:
#0: (&u->bind_mutex){......}, at: [<ffffffffa02e0920>] evtchn_ioctl+0x30/0x3a0 [xen_evtchn]
#1: (irq_mapping_update_lock){......}, at: [<ffffffff8138b274>] bind_evtchn_to_irq+0x24/0x90
Pid: 3216, comm: xenstored Not tainted 3.1.0-rc6-00021-g437a3d1 #2
Call Trace:
[<ffffffff81088d10>] __might_sleep+0x100/0x130
[<ffffffff81645c2f>] mutex_lock_nested+0x2f/0x50
[<ffffffff81627529>] __irq_alloc_descs+0x49/0x200
[<ffffffffa02e0920>] ? evtchn_ioctl+0x30/0x3a0 [xen_evtchn]
[<ffffffff8138b214>] xen_allocate_irq_dynamic+0x34/0x70
[<ffffffff8138b2ad>] bind_evtchn_to_irq+0x5d/0x90
[<ffffffffa02e03c0>] ? evtchn_bind_to_user+0x60/0x60 [xen_evtchn]
[<ffffffff8138c282>] bind_evtchn_to_irqhandler+0x32/0x80
[<ffffffffa02e03a9>] evtchn_bind_to_user+0x49/0x60 [xen_evtchn]
[<ffffffffa02e0a34>] evtchn_ioctl+0x144/0x3a0 [xen_evtchn]
[<ffffffff811b4070>] ? vfsmount_lock_local_unlock+0x50/0x80
[<ffffffff811a6a1a>] do_vfs_ioctl+0x9a/0x5e0
[<ffffffff811b476f>] ? mntput+0x1f/0x30
[<ffffffff81196259>] ? fput+0x199/0x240
[<ffffffff811a7001>] sys_ioctl+0xa1/0xb0
[<ffffffff8164ea82>] system_call_fastpath+0x16/0x1b
Reported-by: Jim Burns <jim_burn@bellsouth.net>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index da70f5c..7523719 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -54,7 +54,7 @@
* This lock protects updates to the following mapping and reference-count
* arrays. The lock does not need to be acquired to read the mapping tables.
*/
-static DEFINE_SPINLOCK(irq_mapping_update_lock);
+static DEFINE_MUTEX(irq_mapping_update_lock);
static LIST_HEAD(xen_irq_list_head);
@@ -631,7 +631,7 @@
int irq = -1;
struct physdev_irq irq_op;
- spin_lock(&irq_mapping_update_lock);
+ mutex_lock(&irq_mapping_update_lock);
irq = find_irq_by_gsi(gsi);
if (irq != -1) {
@@ -684,7 +684,7 @@
handle_edge_irq, name);
out:
- spin_unlock(&irq_mapping_update_lock);
+ mutex_unlock(&irq_mapping_update_lock);
return irq;
}
@@ -710,7 +710,7 @@
{
int irq, ret;
- spin_lock(&irq_mapping_update_lock);
+ mutex_lock(&irq_mapping_update_lock);
irq = xen_allocate_irq_dynamic();
if (irq == -1)
@@ -724,10 +724,10 @@
if (ret < 0)
goto error_irq;
out:
- spin_unlock(&irq_mapping_update_lock);
+ mutex_unlock(&irq_mapping_update_lock);
return irq;
error_irq:
- spin_unlock(&irq_mapping_update_lock);
+ mutex_unlock(&irq_mapping_update_lock);
xen_free_irq(irq);
return -1;
}
@@ -740,7 +740,7 @@
struct irq_info *info = info_for_irq(irq);
int rc = -ENOENT;
- spin_lock(&irq_mapping_update_lock);
+ mutex_lock(&irq_mapping_update_lock);
desc = irq_to_desc(irq);
if (!desc)
@@ -766,7 +766,7 @@
xen_free_irq(irq);
out:
- spin_unlock(&irq_mapping_update_lock);
+ mutex_unlock(&irq_mapping_update_lock);
return rc;
}
@@ -776,7 +776,7 @@
struct irq_info *info;
- spin_lock(&irq_mapping_update_lock);
+ mutex_lock(&irq_mapping_update_lock);
list_for_each_entry(info, &xen_irq_list_head, list) {
if (info == NULL || info->type != IRQT_PIRQ)
@@ -787,7 +787,7 @@
}
irq = -1;
out:
- spin_unlock(&irq_mapping_update_lock);
+ mutex_unlock(&irq_mapping_update_lock);
return irq;
}
@@ -802,7 +802,7 @@
{
int irq;
- spin_lock(&irq_mapping_update_lock);
+ mutex_lock(&irq_mapping_update_lock);
irq = evtchn_to_irq[evtchn];
@@ -818,7 +818,7 @@
}
out:
- spin_unlock(&irq_mapping_update_lock);
+ mutex_unlock(&irq_mapping_update_lock);
return irq;
}
@@ -829,7 +829,7 @@
struct evtchn_bind_ipi bind_ipi;
int evtchn, irq;
- spin_lock(&irq_mapping_update_lock);
+ mutex_lock(&irq_mapping_update_lock);
irq = per_cpu(ipi_to_irq, cpu)[ipi];
@@ -853,7 +853,7 @@
}
out:
- spin_unlock(&irq_mapping_update_lock);
+ mutex_unlock(&irq_mapping_update_lock);
return irq;
}
@@ -878,7 +878,7 @@
struct evtchn_bind_virq bind_virq;
int evtchn, irq;
- spin_lock(&irq_mapping_update_lock);
+ mutex_lock(&irq_mapping_update_lock);
irq = per_cpu(virq_to_irq, cpu)[virq];
@@ -903,7 +903,7 @@
}
out:
- spin_unlock(&irq_mapping_update_lock);
+ mutex_unlock(&irq_mapping_update_lock);
return irq;
}
@@ -913,7 +913,7 @@
struct evtchn_close close;
int evtchn = evtchn_from_irq(irq);
- spin_lock(&irq_mapping_update_lock);
+ mutex_lock(&irq_mapping_update_lock);
if (VALID_EVTCHN(evtchn)) {
close.port = evtchn;
@@ -943,7 +943,7 @@
xen_free_irq(irq);
- spin_unlock(&irq_mapping_update_lock);
+ mutex_unlock(&irq_mapping_update_lock);
}
int bind_evtchn_to_irqhandler(unsigned int evtchn,
@@ -1279,7 +1279,7 @@
will also be masked. */
disable_irq(irq);
- spin_lock(&irq_mapping_update_lock);
+ mutex_lock(&irq_mapping_update_lock);
/* After resume the irq<->evtchn mappings are all cleared out */
BUG_ON(evtchn_to_irq[evtchn] != -1);
@@ -1289,7 +1289,7 @@
xen_irq_info_evtchn_init(irq, evtchn);
- spin_unlock(&irq_mapping_update_lock);
+ mutex_unlock(&irq_mapping_update_lock);
/* new event channels are always bound to cpu 0 */
irq_set_affinity(irq, cpumask_of(0));