On 10/04/2018 18:18, Jason Gunthorpe wrote:
On Tue, Apr 10, 2018 at 06:03:29PM +0300, Matan Barak wrote:
On 09/04/2018 20:24, Jason Gunthorpe wrote:
On Mon, Apr 09, 2018 at 02:18:53PM +0300, Dan Carpenter wrote:
Hello Aviad Yehezkel,
The patch c6475a0bca30: "IB/mlx5: Add implementation for create and
destroy action_xfrm" from Mar 28, 2018, leads to the following static
checker warning:
drivers/infiniband/hw/mlx5/main.c:3256 mlx5_ib_create_flow_action_esp()
error: uninitialized symbol 'action_flags'.
drivers/infiniband/hw/mlx5/main.c
3359 static struct ib_flow_action *
3360 mlx5_ib_create_flow_action_esp(struct ib_device *device,
3361 const struct ib_flow_action_attrs_esp *attr,
3362 struct uverbs_attr_bundle *attrs)
3363 {
3364 struct mlx5_ib_dev *mdev = to_mdev(device);
3365 struct ib_uverbs_flow_action_esp_keymat_aes_gcm *aes_gcm;
3366 struct mlx5_accel_esp_xfrm_attrs accel_attrs = {};
3367 struct mlx5_ib_flow_action *action;
3368 u64 action_flags;
^^^^^^^^^^^^
3369 u64 flags;
3370 int err = 0;
3371
3372 if (IS_UVERBS_COPY_ERR(uverbs_copy_from(&action_flags, attrs,
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
3373 MLX5_IB_ATTR_CREATE_FLOW_ACTION_FLAGS)))
3374 return ERR_PTR(-EFAULT);
3375
3376 if (action_flags >= (MLX5_FLOW_ACTION_ESP_CREATE_LAST_SUPPORTED << 1))
^^^^^^^^^^^^
The problem is that IS_UVERBS_COPY_ERR() treats -ENOENT as A-OK but if
we hit that error then uverbs_copy_from() is a no-op...
It needs to be uverbs_copy_from_or_zero and wrapping in a macro is so
obviously hard to use the macro needs to go too.
uverbs_zcopy_opt() or something
I assume the intent was action_flags is zero'd if not present.. Matan?
That attribute is currently marked as mandatory, so you actually can't get
-ENOENT here (as you'll fail earlier in the parsing stage).
If ENONET is not possible here then what is the point of
IB_UVERBS_COPY_ERR?
Generally, uverbs_copy_from can fail if it can't copy the data
(copy_from_user returns -EFAULT in that case). If we deep dive further,
there's an optimization here and that attribute will be passed inlined,
so even -EFAULT can't happen. However, since how this attribute is
passed shouldn't be a concern for the verbs developer, I prefer to
explicitly write a code that checks if the copy was done successfully
without considering the attribute's size.
Jason
Matan
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