iommu/amd: Fix cleanup_domain for mass device removal

commit 9b29d3c6510407d91786c1cf9183ff4debb3473a upstream.

When multiple devices are detached in __detach_device, they
are also removed from the domains dev_list. This makes it
unsafe to use list_for_each_entry_safe, as the next pointer
might also not be in the list anymore after __detach_device
returns. So just repeatedly remove the first element of the
list until it is empty.

Tested-by: Marti Raudsepp <marti@juffo.org>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 6cc8e67..486982f 100644 (file)
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -2592,14 +2592,16 @@ free_domains:
 
 static void cleanup_domain(struct protection_domain *domain)
 {
-       struct iommu_dev_data *dev_data, *next;
+       struct iommu_dev_data *entry;
        unsigned long flags;
 
        write_lock_irqsave(&amd_iommu_devtable_lock, flags);
 
-       list_for_each_entry_safe(dev_data, next, &domain->dev_list, list) {
-               __detach_device(dev_data);
-               atomic_set(&dev_data->bind, 0);
+       while (!list_empty(&domain->dev_list)) {
+               entry = list_first_entry(&domain->dev_list,
+                                        struct iommu_dev_data, list);
+               __detach_device(entry);
+               atomic_set(&entry->bind, 0);
        }
 
        write_unlock_irqrestore(&amd_iommu_devtable_lock, flags);