Re: [Qemu-trivial] [PATCH v1 2/5] hw/usb/hcd-xhci: Fix GCC 9 build warning

[Laurent Vivier]

Le 30/04/2019 à 22:09, Alistair Francis a écrit :
> Fix this build warning with GCC 9 on Fedora 30:
> hw/usb/hcd-xhci.c:3339:66: error: ‘%d’ directive output may be truncated 
> writing between 1 and 10 bytes into a region of size 5 
> [-Werror=format-truncation=]
>  3339 |             snprintf(port->name, sizeof(port->name), "usb2 port #%d", 
> i+1);
>       |                                                                  ^~
> hw/usb/hcd-xhci.c:3339:54: note: directive argument in the range [1, 
> 2147483647]
>  3339 |             snprintf(port->name, sizeof(port->name), "usb2 port #%d", 
> i+1);

"i" cannot be greater than 15.

perhaps an "assert(i <= MAX(MAXPORTS_2, MAXPORTS_3))" can fix the warning ?

Thanks,
Laurent

>       |                                                      ^~~~~~~~~~~~~~~
> In file included from /usr/include/stdio.h:867,
>                  from /home/alistair/qemu/include/qemu/osdep.h:99,
>                  from hw/usb/hcd-xhci.c:21:
> /usr/include/bits/stdio2.h:67:10: note: ‘__builtin___snprintf_chk’ output 
> between 13 and 22 bytes into a destination of size 16
>    67 |   return __builtin___snprintf_chk (__s, __n, __USE_FORTIFY_LEVEL - 1,
>       |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>    68 |        __bos (__s), __fmt, __va_arg_pack ());
>       |        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 
> Signed-off-by: Alistair Francis <address@hidden>
> ---
>  hw/usb/hcd-xhci.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/hw/usb/hcd-xhci.h b/hw/usb/hcd-xhci.h
> index 240caa4e51..9e4988abb6 100644
> --- a/hw/usb/hcd-xhci.h
> +++ b/hw/usb/hcd-xhci.h
> @@ -133,7 +133,7 @@ typedef struct XHCIPort {
>      uint32_t portnr;
>      USBPort  *uport;
>      uint32_t speedmask;
> -    char name[16];
> +    char name[24];
>      MemoryRegion mem;
>  } XHCIPort;
>  
>