From: Konrad Rzeszutek Wilk Date: Wed, 14 Sep 2011 09:10:00 +0000 (-0400) Subject: xen/irq: Alter the locking to use a mutex instead of a spinlock. X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=773659483685d652970583384a0294948e57f8b3;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git 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: [] evtchn_ioctl+0x30/0x3a0 [xen_evtchn] #1: (irq_mapping_update_lock){......}, at: [] bind_evtchn_to_irq+0x24/0x90 Pid: 3216, comm: xenstored Not tainted 3.1.0-rc6-00021-g437a3d1 #2 Call Trace: [] __might_sleep+0x100/0x130 [] mutex_lock_nested+0x2f/0x50 [] __irq_alloc_descs+0x49/0x200 [] ? evtchn_ioctl+0x30/0x3a0 [xen_evtchn] [] xen_allocate_irq_dynamic+0x34/0x70 [] bind_evtchn_to_irq+0x5d/0x90 [] ? evtchn_bind_to_user+0x60/0x60 [xen_evtchn] [] bind_evtchn_to_irqhandler+0x32/0x80 [] evtchn_bind_to_user+0x49/0x60 [xen_evtchn] [] evtchn_ioctl+0x144/0x3a0 [xen_evtchn] [] ? vfsmount_lock_local_unlock+0x50/0x80 [] do_vfs_ioctl+0x9a/0x5e0 [] ? mntput+0x1f/0x30 [] ? fput+0x199/0x240 [] sys_ioctl+0xa1/0xb0 [] system_call_fastpath+0x16/0x1b Reported-by: Jim Burns Acked-by: Ian Campbell Signed-off-by: Konrad Rzeszutek Wilk --- diff --git a/drivers/xen/events.c b/drivers/xen/events.c index da70f5c32eb9..7523719bf8a4 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 xen_bind_pirq_gsi_to_irq(unsigned gsi, 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 @@ int xen_bind_pirq_gsi_to_irq(unsigned gsi, handle_edge_irq, name); out: - spin_unlock(&irq_mapping_update_lock); + mutex_unlock(&irq_mapping_update_lock); return irq; } @@ -710,7 +710,7 @@ int xen_bind_pirq_msi_to_irq(struct pci_dev *dev, struct msi_desc *msidesc, { 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 @@ int xen_bind_pirq_msi_to_irq(struct pci_dev *dev, struct msi_desc *msidesc, 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 @@ int xen_destroy_irq(int irq) 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 @@ int xen_destroy_irq(int irq) xen_free_irq(irq); out: - spin_unlock(&irq_mapping_update_lock); + mutex_unlock(&irq_mapping_update_lock); return rc; } @@ -776,7 +776,7 @@ int xen_irq_from_pirq(unsigned pirq) 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 @@ int xen_irq_from_pirq(unsigned pirq) } irq = -1; out: - spin_unlock(&irq_mapping_update_lock); + mutex_unlock(&irq_mapping_update_lock); return irq; } @@ -802,7 +802,7 @@ int bind_evtchn_to_irq(unsigned int evtchn) { int irq; - spin_lock(&irq_mapping_update_lock); + mutex_lock(&irq_mapping_update_lock); irq = evtchn_to_irq[evtchn]; @@ -818,7 +818,7 @@ int bind_evtchn_to_irq(unsigned int evtchn) } out: - spin_unlock(&irq_mapping_update_lock); + mutex_unlock(&irq_mapping_update_lock); return irq; } @@ -829,7 +829,7 @@ static int bind_ipi_to_irq(unsigned int ipi, unsigned int cpu) 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 @@ static int bind_ipi_to_irq(unsigned int ipi, unsigned int cpu) } out: - spin_unlock(&irq_mapping_update_lock); + mutex_unlock(&irq_mapping_update_lock); return irq; } @@ -878,7 +878,7 @@ int bind_virq_to_irq(unsigned int virq, unsigned int cpu) 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 @@ int bind_virq_to_irq(unsigned int virq, unsigned int cpu) } out: - spin_unlock(&irq_mapping_update_lock); + mutex_unlock(&irq_mapping_update_lock); return irq; } @@ -913,7 +913,7 @@ static void unbind_from_irq(unsigned int irq) 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 @@ static void unbind_from_irq(unsigned int irq) 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 @@ void rebind_evtchn_irq(int evtchn, int irq) 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 @@ void rebind_evtchn_irq(int evtchn, int irq) 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));