[PATCH 25/26] ib: Convert mthca_map_user_db() to use get_user_pages_fast()

From: Jan Kara
Date: Wed Oct 02 2013 - 10:30:28 EST


Function mthca_map_user_db() appears to call get_user_pages() without
holding mmap_sem. Fix the bug by using get_user_pages_fast() instead
which also takes care of the locking.

CC: Roland Dreier <roland@xxxxxxxxxx>
CC: linux-rdma@xxxxxxxxxxxxxxx
Signed-off-by: Jan Kara <jack@xxxxxxx>
---
drivers/infiniband/hw/mthca/mthca_memfree.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/infiniband/hw/mthca/mthca_memfree.c b/drivers/infiniband/hw/mthca/mthca_memfree.c
index 7d2e42dd6926..c3543b27a2a7 100644
--- a/drivers/infiniband/hw/mthca/mthca_memfree.c
+++ b/drivers/infiniband/hw/mthca/mthca_memfree.c
@@ -472,8 +472,7 @@ int mthca_map_user_db(struct mthca_dev *dev, struct mthca_uar *uar,
goto out;
}

- ret = get_user_pages(current, current->mm, uaddr & PAGE_MASK, 1, 1, 0,
- pages, NULL);
+ ret = get_user_pages_fast(uaddr & PAGE_MASK, 1, 1, pages);
if (ret < 0)
goto out;

--
1.8.1.4

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