Re: [PATCH v1] kdd: remove zero-length arrays

[Christopher Clark <christopher.w.clark@xxxxxxxxx>]

On Thu, Jun 11, 2020 at 12:12 PM Olaf Hering <olaf@xxxxxxxxx> wrote:
>
> Am Wed, 10 Jun 2020 20:16:57 +0100
> schrieb Tim Deegan <tim@xxxxxxx>:
>
> > How tedious.
>
> Indeed. This compiles for me as well:

just a nudge on this; it would be nice to get a patch into the tree
since the build failure affects master builds of Xen in OpenEmbedded
now.

Christopher

>
> --- orig/kdd.h  2020-06-08 17:40:05.000000000 +0000
> +++ kdd.h       2020-06-11 19:00:44.234364040 +0000
> @@ -68,7 +68,6 @@
>      uint16_t len;     /* Payload length, excl. header and trailing byte */
>      uint32_t id;      /* Echoed in responses */
>      uint32_t sum;     /* Unsigned sum of all payload bytes */
> -    uint8_t payload[0];
>  } PACKED kdd_hdr;
>
>  #define KDD_PKT_CMD 0x0002      /* Debugger commands (and replies to them) */
> @@ -323,7 +322,7 @@
>          kdd_msg msg;
>          kdd_reg reg;
>          kdd_stc stc;
> -        uint8_t payload[0];
> +        uint8_t payload[65536];
>      };
>  } PACKED kdd_pkt;
>
> --- orig/kdd.c  2020-06-08 17:40:05.000000000 +0000
> +++ kdd.c       2020-06-11 19:08:36.775724640 +0000
> @@ -79,11 +79,11 @@
>  /* State of the debugger stub */
>  typedef struct {
>      union {
> -        uint8_t txb[sizeof (kdd_hdr) + 65536];   /* Marshalling area for tx 
> */
> +        uint8_t txb[sizeof (kdd_hdr) + 0xffff];   /* Marshalling area for tx 
> */
>          kdd_pkt txp;                 /* Also readable as a packet structure 
> */
>      };
>      union {
> -        uint8_t rxb[sizeof (kdd_hdr) + 65536];   /* Marshalling area for rx 
> */
> +        uint8_t rxb[sizeof (kdd_hdr)];   /* Marshalling area for rx */
>          kdd_pkt rxp;                 /* Also readable as a packet structure 
> */
>      };
>      unsigned int cur;       /* Offset into rx where we'll put the next byte 
> */
>
> Olaf