linux/drivers/infiniband/hw/mlx5/user.h
Yann Droneaud 43bc889380 IB/mlx5: add missing padding at end of struct mlx5_ib_create_srq
The i386 ABI disagrees with most other ABIs regarding alignment of
data type larger than 4 bytes: on most ABIs a padding must be added at
end of the structures, while it is not required on i386.

So for most ABIs struct mlx5_ib_create_srq gets implicitly padded to be
aligned on a 8 bytes multiple, while for i386, such padding is not
added.

Tool pahole could be used to find such implicit padding:

  $ pahole --anon_include \
           --nested_anon_include \
           --recursive \
           --class_name mlx5_ib_create_srq \
           drivers/infiniband/hw/mlx5/mlx5_ib.o

Then, structure layout can be compared between i386 and x86_64:

  +++ obj-i386/drivers/infiniband/hw/mlx5/mlx5_ib.o.pahole.txt    2014-03-28 11:43:07.386413682 +0100
  --- obj-x86_64/drivers/infiniband/hw/mlx5/mlx5_ib.o.pahole.txt  2014-03-27 13:06:17.788472721 +0100
  @@ -69,7 +68,6 @@ struct mlx5_ib_create_srq {
          __u64                      db_addr;              /*     8     8 */
          __u32                      flags;                /*    16     4 */

  -       /* size: 20, cachelines: 1, members: 3 */
  -       /* last cacheline: 20 bytes */
  +       /* size: 24, cachelines: 1, members: 3 */
  +       /* padding: 4 */
  +       /* last cacheline: 24 bytes */
   };

ABI disagreement will make an x86_64 kernel try to read past
the buffer provided by an i386 binary.

When boundary check will be implemented, the x86_64 kernel will
refuse to read past the i386 userspace provided buffer and the
uverb will fail.

Anyway, if the structure lay in memory on a page boundary and
next page is not mapped, ib_copy_from_udata() will fail and the
uverb will fail.

This patch makes create_srq_user() takes care of the input
data size to handle the case where no padding was provided.

This way, x86_64 kernel will be able to handle struct mlx5_ib_create_srq
as sent by unpatched and patched i386 libmlx5.

Link: http://marc.info/?i=cover.1399309513.git.ydroneaud@opteya.com
Cc: <stable@vger.kernel.org>
Fixes: e126ba97db ("mlx5: Add driver for Mellanox Connect-IB adapter")
Signed-off-by: Yann Droneaud <ydroneaud@opteya.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-05-27 11:53:16 -07:00

134 lines
3.3 KiB
C

/*
* Copyright (c) 2013, Mellanox Technologies inc. All rights reserved.
*
* This software is available to you under a choice of one of two
* licenses. You may choose to be licensed under the terms of the GNU
* General Public License (GPL) Version 2, available from the file
* COPYING in the main directory of this source tree, or the
* OpenIB.org BSD license below:
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
*
* - Redistributions of source code must retain the above
* copyright notice, this list of conditions and the following
* disclaimer.
*
* - Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials
* provided with the distribution.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#ifndef MLX5_IB_USER_H
#define MLX5_IB_USER_H
#include <linux/types.h>
enum {
MLX5_QP_FLAG_SIGNATURE = 1 << 0,
MLX5_QP_FLAG_SCATTER_CQE = 1 << 1,
};
enum {
MLX5_SRQ_FLAG_SIGNATURE = 1 << 0,
};
/* Increment this value if any changes that break userspace ABI
* compatibility are made.
*/
#define MLX5_IB_UVERBS_ABI_VERSION 1
/* Make sure that all structs defined in this file remain laid out so
* that they pack the same way on 32-bit and 64-bit architectures (to
* avoid incompatibility between 32-bit userspace and 64-bit kernels).
* In particular do not use pointer types -- pass pointers in __u64
* instead.
*/
struct mlx5_ib_alloc_ucontext_req {
__u32 total_num_uuars;
__u32 num_low_latency_uuars;
};
struct mlx5_ib_alloc_ucontext_req_v2 {
__u32 total_num_uuars;
__u32 num_low_latency_uuars;
__u32 flags;
__u32 reserved;
};
struct mlx5_ib_alloc_ucontext_resp {
__u32 qp_tab_size;
__u32 bf_reg_size;
__u32 tot_uuars;
__u32 cache_line_size;
__u16 max_sq_desc_sz;
__u16 max_rq_desc_sz;
__u32 max_send_wqebb;
__u32 max_recv_wr;
__u32 max_srq_recv_wr;
__u16 num_ports;
__u16 reserved;
};
struct mlx5_ib_alloc_pd_resp {
__u32 pdn;
};
struct mlx5_ib_create_cq {
__u64 buf_addr;
__u64 db_addr;
__u32 cqe_size;
__u32 reserved; /* explicit padding (optional on i386) */
};
struct mlx5_ib_create_cq_resp {
__u32 cqn;
__u32 reserved;
};
struct mlx5_ib_resize_cq {
__u64 buf_addr;
__u16 cqe_size;
__u16 reserved0;
__u32 reserved1;
};
struct mlx5_ib_create_srq {
__u64 buf_addr;
__u64 db_addr;
__u32 flags;
__u32 reserved; /* explicit padding (optional on i386) */
};
struct mlx5_ib_create_srq_resp {
__u32 srqn;
__u32 reserved;
};
struct mlx5_ib_create_qp {
__u64 buf_addr;
__u64 db_addr;
__u32 sq_wqe_count;
__u32 rq_wqe_count;
__u32 rq_wqe_shift;
__u32 flags;
};
struct mlx5_ib_create_qp_resp {
__u32 uuar_index;
};
#endif /* MLX5_IB_USER_H */