On Mon, Sep 21, 2020 at 05:52:57PM +0100, Andre Przywara wrote:
> With -Wsign-compare, compilers warn about a mismatching signedness
> in a comparison in fdt_create_with_flags().
> 
> We have just established that bufsize is not negative, so a cast to an
> unsigned type is safe.
> 
> Signed-off-by: Andre Przywara <andre.przywara-5wv7dgnIgG8@public.gmane.org>

This looks correct, but I think we might be able to do it a bit more
neatly by changing the type of hdrsize to signed instead.  It's a
small value, so we know that's a valid conversion, and that would let
your two tests be merged into one here.

> ---
>  libfdt/fdt_sw.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/libfdt/fdt_sw.c b/libfdt/fdt_sw.c
> index d65e9c8..8a76adf 100644
> --- a/libfdt/fdt_sw.c
> +++ b/libfdt/fdt_sw.c
> @@ -112,7 +112,7 @@ int fdt_create_with_flags(void *buf, int bufsize, uint32_t flags)
>  					 sizeof(struct fdt_reserve_entry));
>  	void *fdt = buf;
>  
> -	if (bufsize < hdrsize)
> +	if (bufsize < 0 || (unsigned)bufsize < hdrsize)
>  		return -FDT_ERR_NOSPACE;
>  
>  	if (flags & ~FDT_CREATE_FLAGS_ALL)

-- 
David Gibson			| I'll have my music baroque, and my code
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				| _way_ _around_!
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