[PATCH] RDMA/cxgb4: Replace 0-length arrays with flexible arrays

Kees Cook
2023-01-05T22:32:57Z

Zero-length arrays are deprecated[1]. Replace all remaining
0-length arrays with flexible arrays. Detected with GCC 13, using
-fstrict-flex-arrays=3:

In function 'build_rdma_write',
inlined from 'c4iw_post_send' at ../drivers/infiniband/hw/cxgb4/qp.c:1173:10:
../drivers/infiniband/hw/cxgb4/qp.c:597:38: warning: array subscript 0 is outside array bounds of 'struct fw_ri_immd[0]' [-Warray-bounds=]
597 | wqe->write.u.immd_src[0].r2 = 0;
| ~~~~~~~~~~~~~~~~~~~~~^~~
../drivers/infiniband/hw/cxgb4/t4fw_ri_api.h: In function 'c4iw_post_send':
../drivers/infiniband/hw/cxgb4/t4fw_ri_api.h:567:35: note: while referencing 'immd_src'
567 | struct fw_ri_immd immd_src[0];
| ^~~~~~~~

Additionally drop the unused C99_NOT_SUPPORTED ifndef lines.

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays

Cc: Potnuri Bharat Teja <bharat@chelsio.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Cc: linux-rdma@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
drivers/infiniband/hw/cxgb4/t4fw_ri_api.h | 26 ++++++-----------------
1 file changed, 6 insertions(+), 20 deletions(-)

diff --git a/drivers/infiniband/hw/cxgb4/t4fw_ri_api.h b/drivers/infiniband/hw/cxgb4/t4fw_ri_api.h
index a2f5e29ef226..1f79537fc8d1 100644
--- a/drivers/infiniband/hw/cxgb4/t4fw_ri_api.h
+++ b/drivers/infiniband/hw/cxgb4/t4fw_ri_api.h
@@ -122,9 +122,7 @@ struct fw_ri_dsgl {
__be16 nsge;
__be32 len0;
__be64 addr0;
-#ifndef C99_NOT_SUPPORTED
struct fw_ri_dsge_pair sge[];
-#endif
};

struct fw_ri_sge {
@@ -138,9 +136,7 @@ struct fw_ri_isgl {
__u8 r1;
__be16 nsge;
__be32 r2;
-#ifndef C99_NOT_SUPPORTED
struct fw_ri_sge sge[];
-#endif
};

struct fw_ri_immd {
@@ -148,9 +144,7 @@ struct fw_ri_immd {
__u8 r1;
__be16 r2;
__be32 immdlen;
-#ifndef C99_NOT_SUPPORTED
__u8 data[];
-#endif
};

struct fw_ri_tpte {
@@ -320,9 +314,7 @@ struct fw_ri_res_wr {
__be32 op_nres;
__be32 len16_pkd;
__u64 cookie;
-#ifndef C99_NOT_SUPPORTED
struct fw_ri_res res[];
-#endif
};

#define FW_RI_RES_WR_NRES_S 0
@@ -562,12 +554,10 @@ struct fw_ri_rdma_write_wr {
__be32 plen;
__be32 stag_sink;
__be64 to_sink;
-#ifndef C99_NOT_SUPPORTED
union {
- struct fw_ri_immd immd_src[0];
- struct fw_ri_isgl isgl_src[0];
+ DECLARE_FLEX_ARRAY(struct fw_ri_immd, immd_src);
+ DECLARE_FLEX_ARRAY(struct fw_ri_isgl, isgl_src);
} u;
-#endif
};

struct fw_ri_send_wr {
@@ -581,12 +571,10 @@ struct fw_ri_send_wr {
__be32 plen;
__be32 r3;
__be64 r4;
-#ifndef C99_NOT_SUPPORTED
union {
- struct fw_ri_immd immd_src[0];
- struct fw_ri_isgl isgl_src[0];
+ DECLARE_FLEX_ARRAY(struct fw_ri_immd, immd_src);
+ DECLARE_FLEX_ARRAY(struct fw_ri_isgl, isgl_src);
} u;
-#endif
};

#define FW_RI_SEND_WR_SENDOP_S 0
@@ -618,12 +606,10 @@ struct fw_ri_rdma_write_cmpl_wr {
struct fw_ri_isgl isgl_src;
} u_cmpl;
__be64 r3;
-#ifndef C99_NOT_SUPPORTED
union fw_ri_write {
- struct fw_ri_immd immd_src[0];
- struct fw_ri_isgl isgl_src[0];
+ DECLARE_FLEX_ARRAY(struct fw_ri_immd, immd_src);
+ DECLARE_FLEX_ARRAY(struct fw_ri_isgl, isgl_src);
} u;
-#endif
};

struct fw_ri_rdma_read_wr {
--
2.34.1