diff options
| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-02-24 18:03:55 -0600 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2020-02-26 16:43:09 -0800 |
| commit | 4a34d825b8939606c3a318341a9de7a4e4d350e7 (patch) | |
| tree | 97ac9ac3e99179ec7db540db296fe4a27f608907 | |
| parent | 3f02735e5da5367e4cd563ce6e5c21ce27922248 (diff) | |
qlogic: Replace zero-length array with flexible-array member
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was detected with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | drivers/net/ethernet/qlogic/netxen/netxen_nic.h | 2 | ||||
| -rw-r--r-- | drivers/net/ethernet/qlogic/qlcnic/qlcnic.h | 8 |
2 files changed, 5 insertions, 5 deletions
diff --git a/drivers/net/ethernet/qlogic/netxen/netxen_nic.h b/drivers/net/ethernet/qlogic/netxen/netxen_nic.h index 3dce769d83a1..86153660d245 100644 --- a/drivers/net/ethernet/qlogic/netxen/netxen_nic.h +++ b/drivers/net/ethernet/qlogic/netxen/netxen_nic.h @@ -1316,7 +1316,7 @@ struct netxen_minidump_template_hdr { u32 driver_info_word4; u32 saved_state_array[NX_DUMP_STATE_ARRAY_LEN]; u32 capture_size_array[NX_DUMP_CAP_SIZE_ARRAY_LEN]; - u32 rsvd[0]; + u32 rsvd[]; }; /* Common Entry Header: Common to All Entry Types */ diff --git a/drivers/net/ethernet/qlogic/qlcnic/qlcnic.h b/drivers/net/ethernet/qlogic/qlcnic/qlcnic.h index 374a4d4371f9..134611aa2c9a 100644 --- a/drivers/net/ethernet/qlogic/qlcnic/qlcnic.h +++ b/drivers/net/ethernet/qlogic/qlcnic/qlcnic.h @@ -418,7 +418,7 @@ struct qlcnic_83xx_dump_template_hdr { u32 saved_state[16]; u32 cap_sizes[8]; u32 ocm_wnd_reg[16]; - u32 rsvd[0]; + u32 rsvd[]; }; struct qlcnic_82xx_dump_template_hdr { @@ -436,7 +436,7 @@ struct qlcnic_82xx_dump_template_hdr { u32 cap_sizes[8]; u32 rsvd[7]; u32 capabilities; - u32 rsvd1[0]; + u32 rsvd1[]; }; #define QLC_PEX_DMA_READ_SIZE (PAGE_SIZE * 16) @@ -740,7 +740,7 @@ struct qlcnic_hostrq_rx_ctx { The following is packed: - N hostrq_rds_rings - N hostrq_sds_rings */ - char data[0]; + char data[]; } __packed; struct qlcnic_cardrsp_rds_ring{ @@ -769,7 +769,7 @@ struct qlcnic_cardrsp_rx_ctx { The following is packed: - N cardrsp_rds_rings - N cardrs_sds_rings */ - char data[0]; + char data[]; } __packed; #define SIZEOF_HOSTRQ_RX(HOSTRQ_RX, rds_rings, sds_rings) \ |