diff mbox series

[v13,16/20] IB/mlx4, arm64: untag user pointers in mlx4_get_umem_mr

Message ID 1e2824fd77e8eeb351c6c6246f384d0d89fd2d58.1553093421.git.andreyknvl@google.com (mailing list archive)
State New, archived
Headers show
Series arm64: untag user pointers passed to the kernel | expand

Commit Message

Andrey Konovalov March 20, 2019, 2:51 p.m. UTC 
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.

mlx4_get_umem_mr() 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 <andreyknvl@google.com>
---
 drivers/infiniband/hw/mlx4/mr.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/drivers/infiniband/hw/mlx4/mr.c b/drivers/infiniband/hw/mlx4/mr.c
index 395379a480cb..9a35ed2c6a6f 100644
--- a/drivers/infiniband/hw/mlx4/mr.c
+++ b/drivers/infiniband/hw/mlx4/mr.c
@@ -378,6 +378,7 @@  static struct ib_umem *mlx4_get_umem_mr(struct ib_udata *udata, u64 start,
 	 * again
 	 */
 	if (!ib_access_writable(access_flags)) {
+		unsigned long untagged_start = untagged_addr(start);
 		struct vm_area_struct *vma;
 
 		down_read(&current->mm->mmap_sem);
@@ -386,9 +387,9 @@  static struct ib_umem *mlx4_get_umem_mr(struct ib_udata *udata, u64 start,
 		 * cover the memory, but for now it requires a single vma to
 		 * entirely cover the MR to support RO mappings.
 		 */
-		vma = find_vma(current->mm, start);
-		if (vma && vma->vm_end >= start + length &&
-		    vma->vm_start <= start) {
+		vma = find_vma(current->mm, untagged_start);
+		if (vma && vma->vm_end >= untagged_start + length &&
+		    vma->vm_start <= untagged_start) {
 			if (vma->vm_flags & VM_WRITE)
 				access_flags |= IB_ACCESS_LOCAL_WRITE;
 		} else {