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net/smc: Avoid -Wflex-array-member-not-at-end warnings

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-Wflex-array-member-not-at-end is coming in GCC-14, and we are getting
ready to enable it globally.

There are currently a couple of objects in `struct smc_clc_msg_proposal_area`
that contain a couple of flexible structures:

struct smc_clc_msg_proposal_area {
	...
	struct smc_clc_v2_extension             pclc_v2_ext;
	...
	struct smc_clc_smcd_v2_extension        pclc_smcd_v2_ext;
	...
};

So, in order to avoid ending up with a couple of flexible-array members
in the middle of a struct, we use the `struct_group_tagged()` helper to
separate the flexible array from the rest of the members in the flexible
structure:

struct smc_clc_smcd_v2_extension {
        struct_group_tagged(smc_clc_smcd_v2_extension_fixed, fixed,
                            u8 system_eid[SMC_MAX_EID_LEN];
                            u8 reserved[16];
        );
        struct smc_clc_smcd_gid_chid gidchid[];
};

With the change described above, we now declare objects of the type of
the tagged struct without embedding flexible arrays in the middle of
another struct:

struct smc_clc_msg_proposal_area {
        ...
        struct smc_clc_v2_extension_fixed	pclc_v2_ext;
        ...
        struct smc_clc_smcd_v2_extension_fixed	pclc_smcd_v2_ext;
        ...
};

We also use `container_of()` when we need to retrieve a pointer to the
flexible structures.

So, with these changes, fix the following warnings:

In file included from net/smc/af_smc.c:42:
net/smc/smc_clc.h:186:49: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
  186 |         struct smc_clc_v2_extension             pclc_v2_ext;
      |                                                 ^~~~~~~~~~~
net/smc/smc_clc.h:188:49: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
  188 |         struct smc_clc_smcd_v2_extension        pclc_smcd_v2_ext;
      |                                                 ^~~~~~~~~~~~~~~~

Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: Wen Gu <guwen@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Gustavo A. R. Silva 2024-03-28 15:52:49 -06:00 committed by David S. Miller
parent b1f81b9a53
commit 9748dbc9f2
2 changed files with 20 additions and 12 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

6
net/smc/smc_clc.c
View file

@ -853,8 +853,10 @@ int smc_clc_send_proposal(struct smc_sock *smc, struct smc_init_info *ini)
pclc_smcd = &pclc->pclc_smcd;
pclc_prfx = &pclc->pclc_prfx;
ipv6_prfx = pclc->pclc_prfx_ipv6;
v2_ext = &pclc->pclc_v2_ext;
smcd_v2_ext = &pclc->pclc_smcd_v2_ext;
v2_ext = container_of(&pclc->pclc_v2_ext,
struct smc_clc_v2_extension, fixed);
smcd_v2_ext = container_of(&pclc->pclc_smcd_v2_ext,
struct smc_clc_smcd_v2_extension, fixed);
gidchids = pclc->pclc_gidchids;
trl = &pclc->pclc_trl;

26
net/smc/smc_clc.h
View file

@ -134,12 +134,15 @@ struct smc_clc_smcd_gid_chid {
*/
struct smc_clc_v2_extension {
struct smc_clnt_opts_area_hdr hdr;
u8 roce[16]; /* RoCEv2 GID */
u8 max_conns;
u8 max_links;
__be16 feature_mask;
u8 reserved[12];
/* New members must be added within the struct_group() macro below. */
struct_group_tagged(smc_clc_v2_extension_fixed, fixed,
struct smc_clnt_opts_area_hdr hdr;
u8 roce[16]; /* RoCEv2 GID */
u8 max_conns;
u8 max_links;
__be16 feature_mask;
u8 reserved[12];
);
u8 user_eids[][SMC_MAX_EID_LEN];
};
@ -159,8 +162,11 @@ struct smc_clc_msg_smcd { /* SMC-D GID information */
};
struct smc_clc_smcd_v2_extension {
u8 system_eid[SMC_MAX_EID_LEN];
u8 reserved[16];
/* New members must be added within the struct_group() macro below. */
struct_group_tagged(smc_clc_smcd_v2_extension_fixed, fixed,
u8 system_eid[SMC_MAX_EID_LEN];
u8 reserved[16];
);
struct smc_clc_smcd_gid_chid gidchid[];
};
@ -183,9 +189,9 @@ struct smc_clc_msg_proposal_area {
struct smc_clc_msg_smcd pclc_smcd;
struct smc_clc_msg_proposal_prefix pclc_prfx;
struct smc_clc_ipv6_prefix pclc_prfx_ipv6[SMC_CLC_MAX_V6_PREFIX];
struct smc_clc_v2_extension pclc_v2_ext;
struct smc_clc_v2_extension_fixed pclc_v2_ext;
u8 user_eids[SMC_CLC_MAX_UEID][SMC_MAX_EID_LEN];
struct smc_clc_smcd_v2_extension pclc_smcd_v2_ext;
struct smc_clc_smcd_v2_extension_fixed pclc_smcd_v2_ext;
struct smc_clc_smcd_gid_chid
pclc_gidchids[SMCD_CLC_MAX_V2_GID_ENTRIES];
struct smc_clc_msg_trail pclc_trl;