IB/uverbs: Use inline data transfer for UHW_IN

The rule for the API is pointers less than 8 bytes are inlined into
the .data field of the attribute. Fix the creation of the driver udata
struct to follow this rule and point to the .data itself when the size
is less than 8 bytes.

Otherwise if the UHW struct is less than 8 bytes the driver will get
EFAULT during copy_from_user.

Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
This commit is contained in:
Jason Gunthorpe 2018-02-13 12:18:30 +02:00
parent 89d9e8d3f1
commit 6c976c30ad

View File

@ -234,8 +234,11 @@ static void create_udata(struct uverbs_attr_bundle *ctx,
uverbs_attr_get(ctx, UVERBS_UHW_OUT);
if (!IS_ERR(uhw_in)) {
udata->inbuf = uhw_in->ptr_attr.ptr;
udata->inlen = uhw_in->ptr_attr.len;
if (uverbs_attr_ptr_is_inline(uhw_in))
udata->inbuf = &uhw_in->uattr->data;
else
udata->inbuf = uhw_in->ptr_attr.ptr;
} else {
udata->inbuf = NULL;
udata->inlen = 0;