diff options
| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-02-24 19:43:46 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2020-02-25 02:26:17 +0300 |
| commit | cc5b48b567a2f668d6f301cb0dd08d65ff1f7fa2 (patch) | |
| tree | cecd8606123980a383bf5dadf2a52eefc29e1ef5 /drivers/net/ethernet/freescale/enetc | |
| parent | 040efdb14c39327da35d2fed902b31fcf4056188 (diff) | |
| download | linux-cc5b48b567a2f668d6f301cb0dd08d65ff1f7fa2.tar.xz | |
freescale: 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 found 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>
Diffstat (limited to 'drivers/net/ethernet/freescale/enetc')
| -rw-r--r-- | drivers/net/ethernet/freescale/enetc/enetc.h | 2 | ||||
| -rw-r--r-- | drivers/net/ethernet/freescale/enetc/enetc_hw.h | 2 |
2 files changed, 2 insertions, 2 deletions
diff --git a/drivers/net/ethernet/freescale/enetc/enetc.h b/drivers/net/ethernet/freescale/enetc/enetc.h index dd4a227ffc7a..9938f7a5fc0a 100644 --- a/drivers/net/ethernet/freescale/enetc/enetc.h +++ b/drivers/net/ethernet/freescale/enetc/enetc.h @@ -163,7 +163,7 @@ struct enetc_int_vector { char name[ENETC_INT_NAME_MAX]; struct enetc_bdr rx_ring ____cacheline_aligned_in_smp; - struct enetc_bdr tx_ring[0]; + struct enetc_bdr tx_ring[]; }; struct enetc_cls_rule { diff --git a/drivers/net/ethernet/freescale/enetc/enetc_hw.h b/drivers/net/ethernet/freescale/enetc/enetc_hw.h index 62554f28ce07..da134e211c1a 100644 --- a/drivers/net/ethernet/freescale/enetc/enetc_hw.h +++ b/drivers/net/ethernet/freescale/enetc/enetc_hw.h @@ -588,7 +588,7 @@ struct tgs_gcl_data { __le32 bth; __le32 ct; __le32 cte; - struct gce entry[0]; + struct gce entry[]; }; struct enetc_cbd { |