From b6ca09cb156d349e6fdde8a8466ec15b902d1419 Mon Sep 17 00:00:00 2001 From: "Gustavo A. R. Silva" Date: Thu, 7 May 2020 13:59:35 -0500 Subject: [PATCH] net/mlx5: Replace zero-length array with flexible-array The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] sizeof(flexible-array-member) triggers a warning because flexible array members have incomplete type[1]. There are some instances of code in which the sizeof operator is being incorrectly/erroneously applied to zero-length arrays and the result is zero. Such instances may be hiding some bugs. So, this work (flexible-array member conversions) will also help to get completely rid of those sorts of issues. This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva Signed-off-by: Saeed Mahameed --- include/linux/mlx5/driver.h | 2 +- include/linux/mlx5/mlx5_ifc.h | 66 +++++++++++++++++------------------ include/linux/mlx5/qp.h | 2 +- 3 files changed, 35 insertions(+), 35 deletions(-) diff --git a/include/linux/mlx5/driver.h b/include/linux/mlx5/driver.h index 267dfcc5493e..24e04901f92e 100644 --- a/include/linux/mlx5/driver.h +++ b/include/linux/mlx5/driver.h @@ -201,7 +201,7 @@ struct mlx5_rsc_debug { void *object; enum dbg_rsc_type type; struct dentry *root; - struct mlx5_field_desc fields[0]; + struct mlx5_field_desc fields[]; }; enum mlx5_dev_event { diff --git a/include/linux/mlx5/mlx5_ifc.h b/include/linux/mlx5/mlx5_ifc.h index fb243848132d..c9dd6e99ad56 100644 --- a/include/linux/mlx5/mlx5_ifc.h +++ b/include/linux/mlx5/mlx5_ifc.h @@ -1703,7 +1703,7 @@ struct mlx5_ifc_wq_bits { u8 reserved_at_140[0x4c0]; - struct mlx5_ifc_cmd_pas_bits pas[0]; + struct mlx5_ifc_cmd_pas_bits pas[]; }; struct mlx5_ifc_rq_num_bits { @@ -1921,7 +1921,7 @@ struct mlx5_ifc_resource_dump_menu_segment_bits { u8 reserved_at_20[0x10]; u8 num_of_records[0x10]; - struct mlx5_ifc_resource_dump_menu_record_bits record[0]; + struct mlx5_ifc_resource_dump_menu_record_bits record[]; }; struct mlx5_ifc_resource_dump_resource_segment_bits { @@ -1933,7 +1933,7 @@ struct mlx5_ifc_resource_dump_resource_segment_bits { u8 index2[0x20]; - u8 payload[0][0x20]; + u8 payload[][0x20]; }; struct mlx5_ifc_resource_dump_terminate_segment_bits { @@ -3010,7 +3010,7 @@ struct mlx5_ifc_flow_context_bits { u8 reserved_at_1200[0x600]; - union mlx5_ifc_dest_format_struct_flow_counter_list_auto_bits destination[0]; + union mlx5_ifc_dest_format_struct_flow_counter_list_auto_bits destination[]; }; enum { @@ -3303,7 +3303,7 @@ struct mlx5_ifc_rqtc_bits { u8 reserved_at_e0[0x6a0]; - struct mlx5_ifc_rq_num_bits rq_num[0]; + struct mlx5_ifc_rq_num_bits rq_num[]; }; enum { @@ -3415,7 +3415,7 @@ struct mlx5_ifc_nic_vport_context_bits { u8 reserved_at_7e0[0x20]; - u8 current_uc_mac_address[0][0x40]; + u8 current_uc_mac_address[][0x40]; }; enum { @@ -4338,7 +4338,7 @@ struct mlx5_ifc_query_xrc_srq_out_bits { u8 reserved_at_280[0x600]; - u8 pas[0][0x40]; + u8 pas[][0x40]; }; struct mlx5_ifc_query_xrc_srq_in_bits { @@ -4616,7 +4616,7 @@ struct mlx5_ifc_query_srq_out_bits { u8 reserved_at_280[0x600]; - u8 pas[0][0x40]; + u8 pas[][0x40]; }; struct mlx5_ifc_query_srq_in_bits { @@ -4827,7 +4827,7 @@ struct mlx5_ifc_query_qp_out_bits { u8 reserved_at_800[0x80]; - u8 pas[0][0x40]; + u8 pas[][0x40]; }; struct mlx5_ifc_query_qp_in_bits { @@ -5160,7 +5160,7 @@ struct mlx5_ifc_query_hca_vport_pkey_out_bits { u8 reserved_at_40[0x40]; - struct mlx5_ifc_pkey_bits pkey[0]; + struct mlx5_ifc_pkey_bits pkey[]; }; struct mlx5_ifc_query_hca_vport_pkey_in_bits { @@ -5196,7 +5196,7 @@ struct mlx5_ifc_query_hca_vport_gid_out_bits { u8 gids_num[0x10]; u8 reserved_at_70[0x10]; - struct mlx5_ifc_array128_auto_bits gid[0]; + struct mlx5_ifc_array128_auto_bits gid[]; }; struct mlx5_ifc_query_hca_vport_gid_in_bits { @@ -5464,7 +5464,7 @@ struct mlx5_ifc_query_flow_counter_out_bits { u8 reserved_at_40[0x40]; - struct mlx5_ifc_traffic_counter_bits flow_statistics[0]; + struct mlx5_ifc_traffic_counter_bits flow_statistics[]; }; struct mlx5_ifc_query_flow_counter_in_bits { @@ -5558,7 +5558,7 @@ struct mlx5_ifc_query_eq_out_bits { u8 reserved_at_300[0x580]; - u8 pas[0][0x40]; + u8 pas[][0x40]; }; struct mlx5_ifc_query_eq_in_bits { @@ -5583,7 +5583,7 @@ struct mlx5_ifc_packet_reformat_context_in_bits { u8 reserved_at_20[0x10]; u8 reformat_data[2][0x8]; - u8 more_reformat_data[0][0x8]; + u8 more_reformat_data[][0x8]; }; struct mlx5_ifc_query_packet_reformat_context_out_bits { @@ -5594,7 +5594,7 @@ struct mlx5_ifc_query_packet_reformat_context_out_bits { u8 reserved_at_40[0xa0]; - struct mlx5_ifc_packet_reformat_context_in_bits packet_reformat_context[0]; + struct mlx5_ifc_packet_reformat_context_in_bits packet_reformat_context[]; }; struct mlx5_ifc_query_packet_reformat_context_in_bits { @@ -5833,7 +5833,7 @@ struct mlx5_ifc_query_cq_out_bits { u8 reserved_at_280[0x600]; - u8 pas[0][0x40]; + u8 pas[][0x40]; }; struct mlx5_ifc_query_cq_in_bits { @@ -6440,7 +6440,7 @@ struct mlx5_ifc_modify_cq_in_bits { u8 reserved_at_300[0x580]; - u8 pas[0][0x40]; + u8 pas[][0x40]; }; struct mlx5_ifc_modify_cong_status_out_bits { @@ -6504,7 +6504,7 @@ struct mlx5_ifc_manage_pages_out_bits { u8 reserved_at_60[0x20]; - u8 pas[0][0x40]; + u8 pas[][0x40]; }; enum { @@ -6526,7 +6526,7 @@ struct mlx5_ifc_manage_pages_in_bits { u8 input_num_entries[0x20]; - u8 pas[0][0x40]; + u8 pas[][0x40]; }; struct mlx5_ifc_mad_ifc_out_bits { @@ -7481,7 +7481,7 @@ struct mlx5_ifc_create_xrc_srq_in_bits { u8 reserved_at_300[0x580]; - u8 pas[0][0x40]; + u8 pas[][0x40]; }; struct mlx5_ifc_create_tis_out_bits { @@ -7557,7 +7557,7 @@ struct mlx5_ifc_create_srq_in_bits { u8 reserved_at_280[0x600]; - u8 pas[0][0x40]; + u8 pas[][0x40]; }; struct mlx5_ifc_create_sq_out_bits { @@ -7718,7 +7718,7 @@ struct mlx5_ifc_create_qp_in_bits { u8 wq_umem_valid[0x1]; u8 reserved_at_861[0x1f]; - u8 pas[0][0x40]; + u8 pas[][0x40]; }; struct mlx5_ifc_create_psv_out_bits { @@ -7789,7 +7789,7 @@ struct mlx5_ifc_create_mkey_in_bits { u8 reserved_at_320[0x560]; - u8 klm_pas_mtt[0][0x20]; + u8 klm_pas_mtt[][0x20]; }; enum { @@ -7922,7 +7922,7 @@ struct mlx5_ifc_create_eq_in_bits { u8 reserved_at_3c0[0x4c0]; - u8 pas[0][0x40]; + u8 pas[][0x40]; }; struct mlx5_ifc_create_dct_out_bits { @@ -7979,7 +7979,7 @@ struct mlx5_ifc_create_cq_in_bits { u8 cq_umem_valid[0x1]; u8 reserved_at_2e1[0x59f]; - u8 pas[0][0x40]; + u8 pas[][0x40]; }; struct mlx5_ifc_config_int_moderation_out_bits { @@ -8335,7 +8335,7 @@ struct mlx5_ifc_access_register_out_bits { u8 reserved_at_40[0x40]; - u8 register_data[0][0x20]; + u8 register_data[][0x20]; }; enum { @@ -8355,7 +8355,7 @@ struct mlx5_ifc_access_register_in_bits { u8 argument[0x20]; - u8 register_data[0][0x20]; + u8 register_data[][0x20]; }; struct mlx5_ifc_sltp_reg_bits { @@ -9372,7 +9372,7 @@ struct mlx5_ifc_cmd_in_bits { u8 reserved_at_20[0x10]; u8 op_mod[0x10]; - u8 command[0][0x20]; + u8 command[][0x20]; }; struct mlx5_ifc_cmd_if_box_bits { @@ -9666,7 +9666,7 @@ struct mlx5_ifc_mcqi_reg_bits { u8 reserved_at_a0[0x10]; u8 data_size[0x10]; - union mlx5_ifc_mcqi_reg_data_bits data[0]; + union mlx5_ifc_mcqi_reg_data_bits data[]; }; struct mlx5_ifc_mcc_reg_bits { @@ -10252,7 +10252,7 @@ struct mlx5_ifc_umem_bits { u8 num_of_mtt[0x40]; - struct mlx5_ifc_mtt_bits mtt[0]; + struct mlx5_ifc_mtt_bits mtt[]; }; struct mlx5_ifc_uctx_bits { @@ -10377,7 +10377,7 @@ struct mlx5_ifc_mtrc_stdb_bits { u8 reserved_at_4[0x4]; u8 read_size[0x18]; u8 start_offset[0x20]; - u8 string_db_data[0]; + u8 string_db_data[]; }; struct mlx5_ifc_mtrc_ctrl_bits { @@ -10431,7 +10431,7 @@ struct mlx5_ifc_query_esw_functions_out_bits { struct mlx5_ifc_host_params_context_bits host_params_context; u8 reserved_at_280[0x180]; - u8 host_sf_enable[0][0x40]; + u8 host_sf_enable[][0x40]; }; struct mlx5_ifc_sf_partition_bits { @@ -10451,7 +10451,7 @@ struct mlx5_ifc_query_sf_partitions_out_bits { u8 reserved_at_60[0x20]; - struct mlx5_ifc_sf_partition_bits sf_partition[0]; + struct mlx5_ifc_sf_partition_bits sf_partition[]; }; struct mlx5_ifc_query_sf_partitions_in_bits { diff --git a/include/linux/mlx5/qp.h b/include/linux/mlx5/qp.h index f23eb18526fe..1af5e460b5f6 100644 --- a/include/linux/mlx5/qp.h +++ b/include/linux/mlx5/qp.h @@ -408,7 +408,7 @@ struct mlx5_wqe_signature_seg { struct mlx5_wqe_inline_seg { __be32 byte_count; - __be32 data[0]; + __be32 data[]; }; enum mlx5_sig_type {