Re: [PATCH v2 10/13] hw/scsi/scsi-disk: Use qemu_hexdump_line() to avoid sprintf()

[Richard Henderson]

On 4/11/24 03:15, Philippe Mathieu-Daudé wrote:
> sprintf() is deprecated on Darwin since macOS 13.0 / XCode 14.1,
> resulting in painful developper experience.
>
> Use qemu_hexdump_line() to avoid sprintf() calls, silencing:
>
>    [105/169] Compiling C object libcommon.fa.p/hw_scsi_scsi-disk.c.o
>    hw/scsi/scsi-disk.c:2659:14: warning: 'sprintf' is deprecated:
>      This function is provided for compatibility reasons only.
>      Due to security concerns inherent in the design of sprintf(3),
>      it is highly recommended that you use snprintf(3) instead.
>      [-Wdeprecated-declarations]
>          p += sprintf(p, " 0x%02x", buf[i]);
>               ^
>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> ---
>   hw/scsi/scsi-disk.c | 8 ++------
>   1 file changed, 2 insertions(+), 6 deletions(-)
>
> diff --git a/hw/scsi/scsi-disk.c b/hw/scsi/scsi-disk.c
> index 4bd7af9d0c..4f914df5c2 100644
> --- a/hw/scsi/scsi-disk.c
> +++ b/hw/scsi/scsi-disk.c
> @@ -2648,16 +2648,12 @@ static const SCSIReqOps *const 
> scsi_disk_reqops_dispatch[256] = {
>   
>   static void scsi_disk_new_request_dump(uint32_t lun, uint32_t tag, uint8_t *buf)
>   {
> -    int i;
>       int len = scsi_cdb_length(buf);
> -    char *line_buffer, *p;
> +    char *line_buffer;
>   
>       assert(len > 0 && len <= 16);
> -    line_buffer = g_malloc(len * 5 + 1);
>   
> -    for (i = 0, p = line_buffer; i < len; i++) {
> -        p += sprintf(p, " 0x%02x", buf[i]);
> -    }
> +    line_buffer = qemu_hexdump_line(buf, 0, len, false);

This is adding "0000: " as an unnecessary prefix, because it's added by 
qemu_hexdump_line.
I think having qemu_hexdump_line as a primitive is good, but probably the offset argument 
should be dropped and printed by the two callers that need it (mostly qemu_hexdump).


r~