LinuxTV Patchwork [v15,16/17] vfio/type1, arm64: untag user pointers in vaddr_get_pfn

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Submitter Andrey Konovalov
Date May 6, 2019, 4:31 p.m.
Message ID <>
Download mbox | patch
Permalink /patch/56055/
State Not Applicable
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Andrey Konovalov - May 6, 2019, 4:31 p.m.
This patch is a part of a series that extends arm64 kernel ABI to allow to
pass tagged user pointers (with the top byte set to something else other
than 0x00) as syscall arguments.

vaddr_get_pfn() uses provided user pointers for vma lookups, which can
only by done with untagged pointers.

Untag user pointers in this function.

Signed-off-by: Andrey Konovalov <>
 drivers/vfio/vfio_iommu_type1.c | 2 ++
 1 file changed, 2 insertions(+)


diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index d0f731c9920a..5daa966d799e 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -382,6 +382,8 @@  static int vaddr_get_pfn(struct mm_struct *mm, unsigned long vaddr,
+	vaddr = untagged_addr(vaddr);
 	vma = find_vma_intersection(mm, vaddr, vaddr + 1);
 	if (vma && vma->vm_flags & VM_PFNMAP) {

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