[PATCH] common/mlx5: fix memory leak in Windows dereg MR function

[michaelba at nvidia.com]

From: Michael Baum <michaelba at nvidia.com>

The "mlx5_devx_cmd_mkey_create" DevX cmd allocates DevX object using
mlx5_malloc and then creates MKey using glue function.
Compatibly, "mlx5_devx_cmd_destroy" cmd releases first the MKey using
glue function, and then free the DevX object using mlx5_free.

On Windows OS, the reg_mr function creates Mkey using
"mlx5_devx_cmd_mkey_create" cmd, but dereg_mr function using directly
glue function without freeing the object.
This behavior causes memory leak at each MR release.

In addition, the dereg_mr function makes sure that the MR pointer is
valid before destroying its fields, but always calls the memset function
that makes a difference to it.

This patch moves the dereg_mr function to use "mlx5_devx_cmd_destroy"
instead of glue function, and extends the validity test to the whole
function.

Fixes: ba420719823c ("common/mlx5: add reg/dereg MR on Windows")
Cc: stable at dpdk.org

Signed-off-by: Michael Baum <michaelba at nvidia.com>
Acked-by: Matan Azrad <matan at nvidia.com>
---
 drivers/common/mlx5/windows/mlx5_common_os.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/common/mlx5/windows/mlx5_common_os.c b/drivers/common/mlx5/windows/mlx5_common_os.c
index 5fb45d12ea..162c7476cc 100644
--- a/drivers/common/mlx5/windows/mlx5_common_os.c
+++ b/drivers/common/mlx5/windows/mlx5_common_os.c
@@ -368,9 +368,11 @@ mlx5_os_reg_mr(void *pd,
 static void
 mlx5_os_dereg_mr(struct mlx5_pmd_mr *pmd_mr)
 {
-	if (pmd_mr && pmd_mr->mkey)
-		claim_zero(mlx5_glue->devx_obj_destroy(pmd_mr->mkey->obj));
-	if (pmd_mr && pmd_mr->obj)
+	if (!pmd_mr)
+		return;
+	if (pmd_mr->mkey)
+		claim_zero(mlx5_devx_cmd_destroy(pmd_mr->mkey));
+	if (pmd_mr->obj)
 		claim_zero(mlx5_os_umem_dereg(pmd_mr->obj));
 	memset(pmd_mr, 0, sizeof(*pmd_mr));
 }
-- 
2.25.1