[PATCH v15 13/17] IB, arm64: untag user pointers in ib_uverbs_(re)reg_mr()

[Andrey Konovalov]

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.

ib_uverbs_(re)reg_mr() use provided user pointers for vma lookups (through
e.g. mlx4_get_umem_mr()), which can only by done with untagged pointers.

Untag user pointers in these functions.

Signed-off-by: Andrey Konovalov <andreyknvl at google.com>
---
 drivers/infiniband/core/uverbs_cmd.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/infiniband/core/uverbs_cmd.c b/drivers/infiniband/core/uverbs_cmd.c
index 062a86c04123..36e7b52577d0 100644
--- a/drivers/infiniband/core/uverbs_cmd.c
+++ b/drivers/infiniband/core/uverbs_cmd.c
@@ -708,6 +708,8 @@ static int ib_uverbs_reg_mr(struct uverbs_attr_bundle *attrs)
 	if (ret)
 		return ret;
 
+	cmd.start = untagged_addr(cmd.start);
+
 	if ((cmd.start & ~PAGE_MASK) != (cmd.hca_va & ~PAGE_MASK))
 		return -EINVAL;
 
@@ -790,6 +792,8 @@ static int ib_uverbs_rereg_mr(struct uverbs_attr_bundle *attrs)
 	if (ret)
 		return ret;
 
+	cmd.start = untagged_addr(cmd.start);
+
 	if (cmd.flags & ~IB_MR_REREG_SUPPORTED || !cmd.flags)
 		return -EINVAL;
 
-- 
2.21.0.1020.gf2820cf01a-goog