From 4378d99295fae5fd42b0ed1a3eeef2a1684e0c17 Mon Sep 17 00:00:00 2001 From: Jay Cornwall Date: Mon, 28 Apr 2014 17:27:46 -0500 Subject: [PATCH] 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 Signed-off-by: Suravee Suthikulpanit Signed-off-by: Joerg Roedel --- drivers/iommu/amd_iommu_v2.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/iommu/amd_iommu_v2.c b/drivers/iommu/amd_iommu_v2.c index 5208828792e6..203b2e6a91cf 100644 --- a/drivers/iommu/amd_iommu_v2.c +++ b/drivers/iommu/amd_iommu_v2.c @@ -504,8 +504,10 @@ static void do_fault(struct work_struct *work) 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); -- 2.34.1