iommu/amd: Take mmap_sem when calling get_user_pages
get_user_pages requires caller to hold a read lock on mmap_sem.
Signed-off-by: Jay Cornwall <jay.cornwall@amd.com>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Joerg Roedel <joro@8bytes.org>
diff --git a/drivers/iommu/amd_iommu_v2.c b/drivers/iommu/amd_iommu_v2.c
index 5208828..203b2e6 100644
--- a/drivers/iommu/amd_iommu_v2.c
+++ b/drivers/iommu/amd_iommu_v2.c
@@ -504,8 +504,10 @@
write = !!(fault->flags & PPR_FAULT_WRITE);
+ down_read(&fault->state->mm->mmap_sem);
npages = get_user_pages(fault->state->task, fault->state->mm,
fault->address, 1, write, 0, &page, NULL);
+ up_read(&fault->state->mm->mmap_sem);
if (npages == 1) {
put_page(page);