Re: [Qemu-devel] [PATCH v3 15/45] windbg: sized data buffer

[Ladi Prosek]

On Tue, Nov 21, 2017 at 3:08 PM, Mihail Abakumov
<address@hidden> wrote:
> Defined useful sized data buffer. It contains pointer to data and size of 
> this data. Also, defined some macros for init and free.
>
> Signed-off-by: Mihail Abakumov <address@hidden>
> Signed-off-by: Pavel Dovgalyuk <address@hidden>
> Signed-off-by: Dmitriy Koltunov <address@hidden>
> ---
>  include/exec/windbgstub-utils.h |   16 ++++++++++++++++
>  1 file changed, 16 insertions(+)
>
> diff --git a/include/exec/windbgstub-utils.h b/include/exec/windbgstub-utils.h
> index 6ce870beb1..b729cd604e 100755
> --- a/include/exec/windbgstub-utils.h
> +++ b/include/exec/windbgstub-utils.h
> @@ -67,6 +67,22 @@ typedef struct PacketData {
>      uint16_t extra_size;
>  } PacketData;
>
> +typedef struct SizedBuf {
> +    uint8_t *data;
> +    size_t size;
> +} SizedBuf;
> +
> +#define SBUF_INIT(buf, mem_ptr, len) do { \
> +    buf.data = mem_ptr;                   \
> +    buf.size = len;                       \
> +} while (false)
> +#define SBUF_MALLOC(buf, size) SBUF_INIT(buf, g_malloc0(size), size)
> +#define SBUF_FREE(buf) do { \
> +    g_free(buf.data);       \
> +    buf.data = NULL;        \
> +    buf.size = 0;           \
> +} while (false)
> +

I don't think that this is necessary. These macros are used for ~240
byte data structures and the points where they are allocated and freed
are super close together.

I'd just put them on the stack in the callers of kd_gen_exception_sc()
and kd_gen_load_symbols_sc() (only one caller each) and remove this
patch.

>  InitedAddr *windbg_get_KPCR(void);
>  InitedAddr *windbg_get_version(void);
>
>