There is a regular need in the kernel to provide a way to declare having a dynamically sized set of trailing elements in a structure. Kernel code should always use “flexible array members”[1] for these cases. The older style of one-element or zero-length arrays should no longer be used[2]. Refactor the code according to the use of a flexible-array member in struct icmsg_negotiate, instead of a one-element array. Also, this helps the ongoing efforts to enable -Warray-bounds and fix the following warnings: drivers/hv/channel_mgmt.c:315:23: warning: array subscript 1 is above array bounds of ‘struct ic_version[1]’ [-Warray-bounds] drivers/hv/channel_mgmt.c:316:23: warning: array subscript 1 is above array bounds of ‘struct ic_version[1]’ [-Warray-bounds] [1] https://en.wikipedia.org/wiki/Flexible_array_member [2] https://www.kernel.org/doc/html/v5.9/process/deprecated.html#zero-length-and-one-element-arrays Link: https://github.com/KSPP/linux/issues/79 Link: https://github.com/KSPP/linux/issues/109 Signed-off-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx> --- include/linux/hyperv.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h index f0d48a368f13..7877746f1077 100644 --- a/include/linux/hyperv.h +++ b/include/linux/hyperv.h @@ -1528,14 +1528,14 @@ struct icmsg_hdr { #define IC_VERSION_NEGOTIATION_MAX_VER_COUNT 100 #define ICMSG_HDR (sizeof(struct vmbuspipe_hdr) + sizeof(struct icmsg_hdr)) #define ICMSG_NEGOTIATE_PKT_SIZE(icframe_vercnt, icmsg_vercnt) \ - (ICMSG_HDR + offsetof(struct icmsg_negotiate, icversion_data) + \ + (ICMSG_HDR + sizeof(struct icmsg_negotiate) + \ (((icframe_vercnt) + (icmsg_vercnt)) * sizeof(struct ic_version))) struct icmsg_negotiate { u16 icframe_vercnt; u16 icmsg_vercnt; u32 reserved; - struct ic_version icversion_data[1]; /* any size array */ + struct ic_version icversion_data[]; /* any size array */ } __packed; struct shutdown_msg_data { -- 2.27.0
