Adding upstream version 4.19.282.upstream/4.19.282

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 46 insertions, 19 deletions

diff --git a/drivers/tty/hvc/hvc_xen.c b/drivers/tty/hvc/hvc_xen.c
index 080adf7bc..59d85bdd1 100644
--- a/drivers/tty/hvc/hvc_xen.c
+++ b/drivers/tty/hvc/hvc_xen.c
@@ -43,6 +43,7 @@ struct xencons_info {
 	int irq;
 	int vtermno;
 	grant_ref_t gntref;
+	spinlock_t ring_lock;
 };
 
 static LIST_HEAD(xenconsoles);
@@ -52,17 +53,22 @@ static DEFINE_SPINLOCK(xencons_lock);
 
 static struct xencons_info *vtermno_to_xencons(int vtermno)
 {
-	struct xencons_info *entry, *n, *ret = NULL;
+	struct xencons_info *entry, *ret = NULL;
+	unsigned long flags;
 
-	if (list_empty(&xenconsoles))
-			return NULL;
+	spin_lock_irqsave(&xencons_lock, flags);
+	if (list_empty(&xenconsoles)) {
+		spin_unlock_irqrestore(&xencons_lock, flags);
+		return NULL;
+	}
 
-	list_for_each_entry_safe(entry, n, &xenconsoles, list) {
+	list_for_each_entry(entry, &xenconsoles, list) {
 		if (entry->vtermno == vtermno) {
 			ret  = entry;
 			break;
 		}
 	}
+	spin_unlock_irqrestore(&xencons_lock, flags);
 
 	return ret;
 }
@@ -84,12 +90,15 @@ static int __write_console(struct xencons_info *xencons,
 	XENCONS_RING_IDX cons, prod;
 	struct xencons_interface *intf = xencons->intf;
 	int sent = 0;
+	unsigned long flags;
 
+	spin_lock_irqsave(&xencons->ring_lock, flags);
 	cons = intf->out_cons;
 	prod = intf->out_prod;
 	mb();			/* update queue values before going on */
 
 	if ((prod - cons) > sizeof(intf->out)) {
+		spin_unlock_irqrestore(&xencons->ring_lock, flags);
 		pr_err_once("xencons: Illegal ring page indices");
 		return -EINVAL;
 	}
@@ -99,6 +108,7 @@ static int __write_console(struct xencons_info *xencons,
 
 	wmb();			/* write ring before updating pointer */
 	intf->out_prod = prod;
+	spin_unlock_irqrestore(&xencons->ring_lock, flags);
 
 	if (sent)
 		notify_daemon(xencons);
@@ -141,16 +151,19 @@ static int domU_read_console(uint32_t vtermno, char *buf, int len)
 	int recv = 0;
 	struct xencons_info *xencons = vtermno_to_xencons(vtermno);
 	unsigned int eoiflag = 0;
+	unsigned long flags;
 
 	if (xencons == NULL)
 		return -EINVAL;
 	intf = xencons->intf;
 
+	spin_lock_irqsave(&xencons->ring_lock, flags);
 	cons = intf->in_cons;
 	prod = intf->in_prod;
 	mb();			/* get pointers before reading ring */
 
 	if ((prod - cons) > sizeof(intf->in)) {
+		spin_unlock_irqrestore(&xencons->ring_lock, flags);
 		pr_err_once("xencons: Illegal ring page indices");
 		return -EINVAL;
 	}
@@ -174,10 +187,13 @@ static int domU_read_console(uint32_t vtermno, char *buf, int len)
 		xencons->out_cons = intf->out_cons;
 		xencons->out_cons_same = 0;
 	}
+	if (!recv && xencons->out_cons_same++ > 1) {
+		eoiflag = XEN_EOI_FLAG_SPURIOUS;
+	}
+	spin_unlock_irqrestore(&xencons->ring_lock, flags);
+
 	if (recv) {
 		notify_daemon(xencons);
-	} else if (xencons->out_cons_same++ > 1) {
-		eoiflag = XEN_EOI_FLAG_SPURIOUS;
 	}
 
 	xen_irq_lateeoi(xencons->irq, eoiflag);
@@ -223,7 +239,7 @@ static int xen_hvm_console_init(void)
 {
 	int r;
 	uint64_t v = 0;
-	unsigned long gfn;
+	unsigned long gfn, flags;
 	struct xencons_info *info;
 
 	if (!xen_hvm_domain())
@@ -234,6 +250,7 @@ static int xen_hvm_console_init(void)
 		info = kzalloc(sizeof(struct xencons_info), GFP_KERNEL);
 		if (!info)
 			return -ENOMEM;
+		spin_lock_init(&info->ring_lock);
 	} else if (info->intf != NULL) {
 		/* already configured */
 		return 0;
@@ -258,9 +275,9 @@ static int xen_hvm_console_init(void)
 		goto err;
 	info->vtermno = HVC_COOKIE;
 
-	spin_lock(&xencons_lock);
+	spin_lock_irqsave(&xencons_lock, flags);
 	list_add_tail(&info->list, &xenconsoles);
-	spin_unlock(&xencons_lock);
+	spin_unlock_irqrestore(&xencons_lock, flags);
 
 	return 0;
 err:
@@ -270,6 +287,7 @@ err:
 
 static int xencons_info_pv_init(struct xencons_info *info, int vtermno)
 {
+	spin_lock_init(&info->ring_lock);
 	info->evtchn = xen_start_info->console.domU.evtchn;
 	/* GFN == MFN for PV guest */
 	info->intf = gfn_to_virt(xen_start_info->console.domU.mfn);
@@ -283,6 +301,7 @@ static int xencons_info_pv_init(struct xencons_info *info, int vtermno)
 static int xen_pv_console_init(void)
 {
 	struct xencons_info *info;
+	unsigned long flags;
 
 	if (!xen_pv_domain())
 		return -ENODEV;
@@ -299,9 +318,9 @@ static int xen_pv_console_init(void)
 		/* already configured */
 		return 0;
 	}
-	spin_lock(&xencons_lock);
+	spin_lock_irqsave(&xencons_lock, flags);
 	xencons_info_pv_init(info, HVC_COOKIE);
-	spin_unlock(&xencons_lock);
+	spin_unlock_irqrestore(&xencons_lock, flags);
 
 	return 0;
 }
@@ -309,6 +328,7 @@ static int xen_pv_console_init(void)
 static int xen_initial_domain_console_init(void)
 {
 	struct xencons_info *info;
+	unsigned long flags;
 
 	if (!xen_initial_domain())
 		return -ENODEV;
@@ -318,14 +338,15 @@ static int xen_initial_domain_console_init(void)
 		info = kzalloc(sizeof(struct xencons_info), GFP_KERNEL);
 		if (!info)
 			return -ENOMEM;
+		spin_lock_init(&info->ring_lock);
 	}
 
 	info->irq = bind_virq_to_irq(VIRQ_CONSOLE, 0, false);
 	info->vtermno = HVC_COOKIE;
 
-	spin_lock(&xencons_lock);
+	spin_lock_irqsave(&xencons_lock, flags);
 	list_add_tail(&info->list, &xenconsoles);
-	spin_unlock(&xencons_lock);
+	spin_unlock_irqrestore(&xencons_lock, flags);
 
 	return 0;
 }
@@ -380,10 +401,12 @@ static void xencons_free(struct xencons_info *info)
 
 static int xen_console_remove(struct xencons_info *info)
 {
+	unsigned long flags;
+
 	xencons_disconnect_backend(info);
-	spin_lock(&xencons_lock);
+	spin_lock_irqsave(&xencons_lock, flags);
 	list_del(&info->list);
-	spin_unlock(&xencons_lock);
+	spin_unlock_irqrestore(&xencons_lock, flags);
 	if (info->xbdev != NULL)
 		xencons_free(info);
 	else {
@@ -464,6 +487,7 @@ static int xencons_probe(struct xenbus_device *dev,
 {
 	int ret, devid;
 	struct xencons_info *info;
+	unsigned long flags;
 
 	devid = dev->nodename[strlen(dev->nodename) - 1] - '0';
 	if (devid == 0)
@@ -472,6 +496,7 @@ static int xencons_probe(struct xenbus_device *dev,
 	info = kzalloc(sizeof(struct xencons_info), GFP_KERNEL);
 	if (!info)
 		return -ENOMEM;
+	spin_lock_init(&info->ring_lock);
 	dev_set_drvdata(&dev->dev, info);
 	info->xbdev = dev;
 	info->vtermno = xenbus_devid_to_vtermno(devid);
@@ -482,9 +507,9 @@ static int xencons_probe(struct xenbus_device *dev,
 	ret = xencons_connect_backend(dev, info);
 	if (ret < 0)
 		goto error;
-	spin_lock(&xencons_lock);
+	spin_lock_irqsave(&xencons_lock, flags);
 	list_add_tail(&info->list, &xenconsoles);
-	spin_unlock(&xencons_lock);
+	spin_unlock_irqrestore(&xencons_lock, flags);
 
 	return 0;
 
@@ -583,10 +608,12 @@ static int __init xen_hvc_init(void)
 
 	info->hvc = hvc_alloc(HVC_COOKIE, info->irq, ops, 256);
 	if (IS_ERR(info->hvc)) {
+		unsigned long flags;
+
 		r = PTR_ERR(info->hvc);
-		spin_lock(&xencons_lock);
+		spin_lock_irqsave(&xencons_lock, flags);
 		list_del(&info->list);
-		spin_unlock(&xencons_lock);
+		spin_unlock_irqrestore(&xencons_lock, flags);
 		if (info->irq)
 			unbind_from_irqhandler(info->irq, NULL);
 		kfree(info);