On 09/08/2024 00:07, Gustavo A. R. Silva wrote:
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.
Read up what the macro does. I like it.
Compile tested on s390.
Reviewed-by: Jan Karcher <jaka@xxxxxxxxxxxxx>
Signed-off-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>
---
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;
