| Message ID | 20200213183715.GA19636@embeddedor (mailing list archive) |
|---|---|
| State | Accepted |
| Delegated to: | Jason Gunthorpe |
| Headers | show |
| Series | IB/core: Replace zero-length array with flexible-array member | expand |
On 2/13/20 12:38, Jason Gunthorpe wrote: > > Any reason to skip these two? > > drivers/infiniband/core/mad_priv.h: u8 mad[0]; > drivers/infiniband/core/mad_priv.h: u8 data[0]; > > And may as well touch these in the subsystem headers too: > > include/rdma/ib_fmr_pool.h: u64 page_list[0]; > include/rdma/ib_verbs.h: u8 real_sz[0]; > include/rdma/ib_verbs.h: u8 real_sz[0]; > include/rdma/ib_verbs.h: u8 real_sz[0]; > include/rdma/ib_verbs.h: u8 real_sz[0]; > include/rdma/ib_verbs.h: u8 real_sz[0]; > include/rdma/ib_verbs.h: u8 real_sz[0]; > include/rdma/ib_verbs.h: u8 real_sz[0]; > include/rdma/ib_verbs.h: u8 real_sz[0]; > include/rdma/ib_verbs.h: u8 real_sz[0]; > include/rdma/opa_vnic.h: char *dev_priv[0]; > include/rdma/rdmavt_mr.h: struct rvt_segarray *map[0]; /* the segments */ > include/rdma/rdmavt_qp.h: struct rvt_sge sg_list[0]; > > ? OK. Let me tweak my script a bit to catch all of those. Thanks for the feedback. -- Gustavo
diff --git a/drivers/infiniband/core/cache.c b/drivers/infiniband/core/cache.c index 17bfedd24cc3..dedfbe27916f 100644 --- a/drivers/infiniband/core/cache.c +++ b/drivers/infiniband/core/cache.c @@ -46,7 +46,7 @@ struct ib_pkey_cache { int table_len; - u16 table[0]; + u16 table[]; }; struct ib_update_work { diff --git a/drivers/infiniband/core/cm.c b/drivers/infiniband/core/cm.c index 68cc1b2d6824..8424abe83607 100644 --- a/drivers/infiniband/core/cm.c +++ b/drivers/infiniband/core/cm.c @@ -197,7 +197,7 @@ struct cm_device { struct ib_device *ib_device; u8 ack_delay; int going_down; - struct cm_port *port[0]; + struct cm_port *port[]; }; struct cm_av { @@ -216,7 +216,7 @@ struct cm_work { __be32 local_id; /* Established / timewait */ __be32 remote_id; struct ib_cm_event cm_event; - struct sa_path_rec path[0]; + struct sa_path_rec path[]; }; struct cm_timewait_info { diff --git a/drivers/infiniband/core/multicast.c b/drivers/infiniband/core/multicast.c index cd338ddc4a39..9c2d8b7f1af9 100644 --- a/drivers/infiniband/core/multicast.c +++ b/drivers/infiniband/core/multicast.c @@ -71,7 +71,7 @@ struct mcast_device { struct ib_event_handler event_handler; int start_port; int end_port; - struct mcast_port port[0]; + struct mcast_port port[]; }; enum mcast_state { diff --git a/drivers/infiniband/core/sa_query.c b/drivers/infiniband/core/sa_query.c index 30d4c126a2db..74e0058fcf9e 100644 --- a/drivers/infiniband/core/sa_query.c +++ b/drivers/infiniband/core/sa_query.c @@ -101,7 +101,7 @@ struct ib_sa_port { struct ib_sa_device { int start_port, end_port; struct ib_event_handler event_handler; - struct ib_sa_port port[0]; + struct ib_sa_port port[]; }; struct ib_sa_query {
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> --- drivers/infiniband/core/cache.c | 2 +- drivers/infiniband/core/cm.c | 4 ++-- drivers/infiniband/core/multicast.c | 2 +- drivers/infiniband/core/sa_query.c | 2 +- 4 files changed, 5 insertions(+), 5 deletions(-)