[Patch] linux: avoid kmalloc while disabling interrupts

[Akio Takebe <takebe_akio@jp.fujitsu.com>]

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Hi,

We should avoid using kmalloc while interrupts is disabled.
kmalloc may sleep.

Signed-off-by: Akio Takebe <takebe_akio@jp.fujitsu.com>

Best Regards,

Akio Takebe

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diff -r e86f9e05144a drivers/xen/pciback/controller.c
--- a/drivers/xen/pciback/controller.c	Mon Sep 08 14:02:13 2008 +0100
+++ b/drivers/xen/pciback/controller.c	Tue Sep 09 16:28:20 2008 +0900
@@ -101,15 +101,15 @@
 	unsigned long flags;
 	int ret = 0, found = 0;
 
+	/* Look to see if we already have a domain:bus for this controller */
 	spin_lock_irqsave(&dev_data->lock, flags);
-
-	/* Look to see if we already have a domain:bus for this controller */
 	list_for_each_entry(cntrl_entry, &dev_data->list, list) {
 		if (cntrl_entry->controller == dev_controller) {
 			found = 1;
 			break;
 		}
 	}
+	spin_unlock_irqrestore(&dev_data->lock, flags);
 
 	if (!found) {
 		cntrl_entry = kmalloc(sizeof(*cntrl_entry), GFP_ATOMIC);
@@ -128,9 +128,10 @@
 			dev_data->next_bus = 0;
 		}
 
+		spin_lock_irqsave(&dev_data->lock, flags);
 		INIT_LIST_HEAD(&cntrl_entry->dev_list);
-
 		list_add_tail(&cntrl_entry->list, &dev_data->list);
+		spin_unlock_irqrestore(&dev_data->lock, flags);
 	}
 
 	if (PCI_SLOT(cntrl_entry->next_devfn) > PCI_MAX_SLOTS) {
@@ -149,24 +150,24 @@
 
 	dev_entry = kmalloc(sizeof(*dev_entry), GFP_ATOMIC);
 	if (!dev_entry) {
+		spin_lock_irqsave(&dev_data->lock, flags);
 		if (list_empty(&cntrl_entry->dev_list)) {
 			list_del(&cntrl_entry->list);
 			kfree(cntrl_entry);
 		}
 		ret = -ENOMEM;
+		spin_unlock_irqrestore(&dev_data->lock, flags);
 		goto out;
 	}
 
 	dev_entry->dev = dev;
 	dev_entry->devfn = cntrl_entry->next_devfn;
 
+	spin_lock_irqsave(&dev_data->lock, flags);
 	list_add_tail(&dev_entry->list, &cntrl_entry->dev_list);
-
 	cntrl_entry->next_devfn += PCI_DEVFN(1, 0);
-
+	spin_unlock_irqrestore(&dev_data->lock, flags);
 out:
-	spin_unlock_irqrestore(&dev_data->lock, flags);
-
 	/* TODO: Publish virtual domain:bus:slot.func here. */
 
 	return ret;

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