nfp: Avoid -Wflex-array-member-not-at-end warnings

-Wflex-array-member-not-at-end is coming in GCC-14, and we are getting ready to enable it globally. There is currently an object (`tl`), at the beginning of multiple structures, that contains a flexible structure (`struct nfp_dump_tl`), for example: struct nfp_dumpspec_csr { struct nfp_dump_tl tl; ... __be32 register_width; /* in bits */ }; So, in order to avoid ending up with flexible-array members in the middle of multiple other structs, we use the `struct_group_tagged()` helper to separate the flexible array from the rest of the members in the flexible structure: struct nfp_dump_tl { struct_group_tagged(nfp_dump_tl_hdr, hdr, ... the rest of members ); char data[]; }; With the change described above, we now declare objects of the type of the tagged struct, in this case `struct nfp_dump_tl_hdr`, without embedding flexible arrays in the middle of another struct: struct nfp_dumpspec_csr { struct nfp_dump_tl_hdr tl; ... __be32 register_width; /* in bits */ }; Also, use `container_of()` whenever we need to retrieve a pointer to the flexible structure, through which we can access the flexible array if needed. So, with these changes, fix 33 of the following warnings: drivers/net/ethernet/netronome/nfp/nfp_net_debugdump.c:58:28: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] drivers/net/ethernet/netronome/nfp/nfp_net_debugdump.c:64:28: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] drivers/net/ethernet/netronome/nfp/nfp_net_debugdump.c:70:28: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] drivers/net/ethernet/netronome/nfp/nfp_net_debugdump.c:78:28: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] drivers/net/ethernet/netronome/nfp/nfp_net_debugdump.c:87:28: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] drivers/net/ethernet/netronome/nfp/nfp_net_debugdump.c:92:28: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] Link: KSPP/linux#202 Signed-off-by: Gustavo A. R. Silva <[email protected]> Link: https://lore.kernel.org/r/ZgYWlkxdrrieDYIu@neat Signed-off-by: Jakub Kicinski <[email protected]> [Ryno: backport and add compat] Signed-off-by: Ryno Swart <[email protected]> Signed-off-by: Louis Peens <[email protected]>
Netronome · Apr 5, 2024 · 4a05860 · 4a05860
1 parent de2168f
commit 4a05860
Showing 1 changed file with 76 additions and 0 deletions.
diff --git a/src/nfp_net_debugdump.c b/src/nfp_net_debugdump.c
@@ -36,8 +36,16 @@ enum nfp_dumpspec_type {
 
 /* generic type plus length */
 struct nfp_dump_tl {
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 16, 0)
+	/* New members must be added within the struct_group() macro below. */
+	struct_group_tagged(nfp_dump_tl_hdr, hdr,
+		__be32 type;
+		__be32 length;	/* chunk length to follow, aligned to 8 bytes */
+	);
+#else
 	__be32 type;
 	__be32 length;	/* chunk length to follow, aligned to 8 bytes */
+#endif
 	char data[];
 };
 
@@ -57,27 +65,43 @@ struct nfp_dump_common_cpp {
 
 /* CSR dumpables */
 struct nfp_dumpspec_csr {
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 16, 0)
+	struct nfp_dump_tl_hdr tl;
+#else
 	struct nfp_dump_tl tl;
+#endif
 	struct nfp_dump_common_cpp cpp;
 	__be32 register_width;	/* in bits */
 };
 
 struct nfp_dumpspec_rtsym {
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 16, 0)
+	struct nfp_dump_tl_hdr tl;
+#else
 	struct nfp_dump_tl tl;
+#endif
 	char rtsym[];
 };
 
 /* header for register dumpable */
 struct nfp_dump_csr {
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 16, 0)
+	struct nfp_dump_tl_hdr tl;
+#else
 	struct nfp_dump_tl tl;
+#endif
 	struct nfp_dump_common_cpp cpp;
 	__be32 register_width;	/* in bits */
 	__be32 error;		/* error code encountered while reading */
 	__be32 error_offset;	/* offset being read when error occurred */
 };
 
 struct nfp_dump_rtsym {
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 16, 0)
+	struct nfp_dump_tl_hdr tl;
+#else
 	struct nfp_dump_tl tl;
+#endif
 	struct nfp_dump_common_cpp cpp;
 	__be32 error;		/* error code encountered while reading */
 	u8 padded_name_length;	/* pad so data starts at 8 byte boundary */
@@ -86,12 +110,20 @@ struct nfp_dump_rtsym {
 };
 
 struct nfp_dump_prolog {
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 16, 0)
+	struct nfp_dump_tl_hdr tl;
+#else
 	struct nfp_dump_tl tl;
+#endif
 	__be32 dump_level;
 };
 
 struct nfp_dump_error {
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 16, 0)
+	struct nfp_dump_tl_hdr tl;
+#else
 	struct nfp_dump_tl tl;
+#endif
 	__be32 error;
 	char padding[4];
 	char spec[];
@@ -451,6 +483,10 @@ static int
 nfp_dump_csr_range(struct nfp_pf *pf, struct nfp_dumpspec_csr *spec_csr,
 		   struct nfp_dump_state *dump)
 {
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 16, 0)
+	struct nfp_dump_tl *spec_csr_tl =
+			container_of(&spec_csr->tl, struct nfp_dump_tl, hdr);
+#endif
 	struct nfp_dump_csr *dump_header = dump->p;
 	u32 reg_sz, header_size, total_size;
 	u32 cpp_rd_addr, max_rd_addr;
@@ -460,15 +496,23 @@ nfp_dump_csr_range(struct nfp_pf *pf, struct nfp_dumpspec_csr *spec_csr,
 	int err;
 
 	if (!nfp_csr_spec_valid(spec_csr))
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 16, 0)
+		return nfp_dump_error_tlv(spec_csr_tl, -EINVAL, dump);
+#else
 		return nfp_dump_error_tlv(&spec_csr->tl, -EINVAL, dump);
+#endif
 
 	reg_sz = be32_to_cpu(spec_csr->register_width) / BITS_PER_BYTE;
 	header_size = ALIGN8(sizeof(*dump_header));
 	total_size = header_size +
 		     ALIGN8(be32_to_cpu(spec_csr->cpp.dump_length));
 	dest = dump->p + header_size;
 
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 16, 0)
+	err = nfp_add_tlv(be32_to_cpu(spec_csr_tl->type), total_size, dump);
+#else
 	err = nfp_add_tlv(be32_to_cpu(spec_csr->tl.type), total_size, dump);
+#endif
 	if (err)
 		return err;
 
@@ -554,6 +598,10 @@ nfp_dump_indirect_csr_range(struct nfp_pf *pf,
 			    struct nfp_dumpspec_csr *spec_csr,
 			    struct nfp_dump_state *dump)
 {
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 16, 0)
+	struct nfp_dump_tl *spec_csr_tl =
+			container_of(&spec_csr->tl, struct nfp_dump_tl, hdr);
+#endif
 	struct nfp_dump_csr *dump_header = dump->p;
 	u32 reg_sz, header_size, total_size;
 	u32 cpp_rd_addr, max_rd_addr;
@@ -562,7 +610,11 @@ nfp_dump_indirect_csr_range(struct nfp_pf *pf,
 	int err;
 
 	if (!nfp_csr_spec_valid(spec_csr))
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 16, 0)
+		return nfp_dump_error_tlv(spec_csr_tl, -EINVAL, dump);
+#else
 		return nfp_dump_error_tlv(&spec_csr->tl, -EINVAL, dump);
+#endif
 
 	reg_sz = be32_to_cpu(spec_csr->register_width) / BITS_PER_BYTE;
 	header_size = ALIGN8(sizeof(*dump_header));
@@ -571,7 +623,11 @@ nfp_dump_indirect_csr_range(struct nfp_pf *pf,
 	total_size = header_size + ALIGN8(reg_data_length);
 	dest = dump->p + header_size;
 
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 16, 0)
+	err = nfp_add_tlv(be32_to_cpu(spec_csr_tl->type), total_size, dump);
+#else
 	err = nfp_add_tlv(be32_to_cpu(spec_csr->tl.type), total_size, dump);
+#endif
 	if (err)
 		return err;
 
@@ -599,6 +655,10 @@ static int
 nfp_dump_single_rtsym(struct nfp_pf *pf, struct nfp_dumpspec_rtsym *spec,
 		      struct nfp_dump_state *dump)
 {
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 16, 0)
+	struct nfp_dump_tl *spec_tl =
+			container_of(&spec->tl, struct nfp_dump_tl, hdr);
+#endif
 	struct nfp_dump_rtsym *dump_header = dump->p;
 	struct nfp_dumpspec_cpp_isl_id cpp_params;
 	struct nfp_rtsym_table *rtbl = pf->rtbl;
@@ -609,22 +669,38 @@ nfp_dump_single_rtsym(struct nfp_pf *pf, struct nfp_dumpspec_rtsym *spec,
 	void *dest;
 	int err;
 
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 16, 0)
+	tl_len = be32_to_cpu(spec_tl->length);
+#else
 	tl_len = be32_to_cpu(spec->tl.length);
+#endif
 	key_len = strnlen(spec->rtsym, tl_len);
 	if (key_len == tl_len)
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 16, 0)
+		return nfp_dump_error_tlv(spec_tl, -EINVAL, dump);
+#else
 		return nfp_dump_error_tlv(&spec->tl, -EINVAL, dump);
+#endif
 
 	sym = nfp_rtsym_lookup(rtbl, spec->rtsym);
 	if (!sym)
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 16, 0)
+		return nfp_dump_error_tlv(spec_tl, -ENOENT, dump);
+#else
 		return nfp_dump_error_tlv(&spec->tl, -ENOENT, dump);
+#endif
 
 	sym_size = nfp_rtsym_size(sym);
 	header_size =
 		ALIGN8(offsetof(struct nfp_dump_rtsym, rtsym) + key_len + 1);
 	total_size = header_size + ALIGN8(sym_size);
 	dest = dump->p + header_size;
 
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 16, 0)
+	err = nfp_add_tlv(be32_to_cpu(spec_tl->type), total_size, dump);
+#else
 	err = nfp_add_tlv(be32_to_cpu(spec->tl.type), total_size, dump);
+#endif
 	if (err)
 		return err;