From 0a3e6939d4b33d68bce89477b9db01d68b744749 Mon Sep 17 00:00:00 2001 From: "Gustavo A. R. Silva" Date: Thu, 8 Aug 2024 16:07:54 -0600 Subject: [PATCH] net/smc: Use static_assert() to check struct sizes Commit 9748dbc9f265 ("net/smc: Avoid -Wflex-array-member-not-at-end warnings") introduced tagged `struct smc_clc_v2_extension_fixed` and `struct smc_clc_smcd_v2_extension_fixed`. We want to ensure that when new members need to be added to the flexible structures, they are always included within these tagged structs. So, we use `static_assert()` to ensure that the memory layout for both the flexible structure and the tagged struct is the same after any changes. Signed-off-by: Gustavo A. R. Silva Reviewed-by: Jan Karcher Link: https://patch.msgid.link/ZrVBuiqFHAORpFxE@cute Signed-off-by: Jakub Kicinski --- net/smc/smc_clc.h | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/net/smc/smc_clc.h b/net/smc/smc_clc.h index 467effb50cd6..5625fda2960b 100644 --- a/net/smc/smc_clc.h +++ b/net/smc/smc_clc.h @@ -145,6 +145,8 @@ struct smc_clc_v2_extension { ); u8 user_eids[][SMC_MAX_EID_LEN]; }; +static_assert(offsetof(struct smc_clc_v2_extension, user_eids) == sizeof(struct smc_clc_v2_extension_fixed), + "struct member likely outside of struct_group_tagged()"); struct smc_clc_msg_proposal_prefix { /* prefix part of clc proposal message*/ __be32 outgoing_subnet; /* subnet mask */ @@ -169,6 +171,8 @@ struct smc_clc_smcd_v2_extension { ); struct smc_clc_smcd_gid_chid gidchid[]; }; +static_assert(offsetof(struct smc_clc_smcd_v2_extension, gidchid) == sizeof(struct smc_clc_smcd_v2_extension_fixed), + "struct member likely outside of struct_group_tagged()"); struct smc_clc_msg_proposal { /* clc proposal message sent by Linux */ struct smc_clc_msg_hdr hdr;