Re: [PATCH] usb: dwc2: gadget: Fix a warning when compiling with W=1

[Greg Kroah-Hartman]

On Sat, Sep 23, 2023 at 12:54:24PM +0200, Christophe JAILLET wrote:
> In order to teach the compiler that 'hs_ep->name' will never be truncated,
> we need to tell it that 'epnum' is not negative.
> 
> 'epnum' comes from in a 'for' loop in dwc2_gadget_init(), starting at 0
> and ending at 255. (hsotg->num_of_eps is a char)
> 
> When building with W=1, this fixes the following warnings:
> 
>   drivers/usb/dwc2/gadget.c: In function ‘dwc2_hsotg_initep’:
>   drivers/usb/dwc2/gadget.c:4804:55: error: ‘%d’ directive output may be truncated writing between 1 and 11 bytes into a region of size 8 [-Werror=format-truncation=]
>    4804 |         snprintf(hs_ep->name, sizeof(hs_ep->name), "ep%d%s", epnum, dir);
>         |                                                       ^~
>   drivers/usb/dwc2/gadget.c:4804:52: note: directive argument in the range [-2147483645, 255]
>    4804 |         snprintf(hs_ep->name, sizeof(hs_ep->name), "ep%d%s", epnum, dir);
>         |                                                    ^~~~~~~~
>   drivers/usb/dwc2/gadget.c:4804:9: note: ‘snprintf’ output between 6 and 17 bytes into a destination of size 10
>    4804 |         snprintf(hs_ep->name, sizeof(hs_ep->name), "ep%d%s", epnum, dir);
>         |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 
> Fixes: 5b7d70c6dbf2 ("USB: Gadget driver for Samsung HS/OtG block")
> Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>

Looks like the kernel test robot didn't like this one :(