[PATCH v2] IB/core: Use memdup_user() rather than duplicating its implementation

SF Markus Elfring
2016-08-22T16:31:15Z

Date: Mon, 22 Aug 2016 18:23:24 +0200

* Reuse existing functionality from memdup_user() instead of keeping
duplicate source code.

This issue was detected by using the Coccinelle software.

* The local variable "ret" will be set to an appropriate value a bit later.
Thus omit the explicit initialisation at the beginning.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---

v2: The desired changes were put into a single patch instead of
distributing them over two update steps.

include/rdma/ib_verbs.h | 11 +++--------
1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
index 6f667dd..0d8100f 100644
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -2199,22 +2199,17 @@ static inline bool ib_is_udata_cleared(struct ib_udata *udata,
size_t len)
{
const void __user *p = udata->inbuf + offset;
- bool ret = false;
+ bool ret;
u8 *buf;

if (len > USHRT_MAX)
return false;

- buf = kmalloc(len, GFP_KERNEL);
- if (!buf)
+ buf = memdup_user(p, len);
+ if (IS_ERR(buf))
return false;

- if (copy_from_user(buf, p, len))
- goto free;
-
ret = !memchr_inv(buf, 0, len);
-
-free:
kfree(buf);
return ret;
}
--
2.9.3