Re: [PATCH v2 2/6] libfdt: fdt_move(): Fix comparison warnings

[David Gibson <david-xT8FGy+AXnRB3Ne2BGzF6laj5H9X9Tb+@public.gmane.org>]

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On Thu, Oct 01, 2020 at 05:46:26PM +0100, Andre Przywara wrote:
> With -Wsign-compare, compilers warn about a mismatching signedness
> in comparisons in fdt_move().
> 
> This stems from "bufsize" being passed in as a signed integer, even
> though we would expect a buffer size to be positive.
> 
> Short of changing the prototype, check that bufsize is not negative, and
> cast it to an unsigned type in the comparison.
> 
> Signed-off-by: Andre Przywara <andre.przywara-5wv7dgnIgG8@public.gmane.org>

Applied, thanks.

> ---
>  libfdt/fdt.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/libfdt/fdt.c b/libfdt/fdt.c
> index 04e1e06..6cf2fa0 100644
> --- a/libfdt/fdt.c
> +++ b/libfdt/fdt.c
> @@ -314,9 +314,12 @@ const char *fdt_find_string_(const char *strtab, int tabsize, const char *s)
>  
>  int fdt_move(const void *fdt, void *buf, int bufsize)
>  {
> +	if (!can_assume(VALID_INPUT) && bufsize < 0)
> +		return -FDT_ERR_NOSPACE;
> +
>  	FDT_RO_PROBE(fdt);
>  
> -	if (fdt_totalsize(fdt) > bufsize)
> +	if (fdt_totalsize(fdt) > (unsigned int)bufsize)
>  		return -FDT_ERR_NOSPACE;
>  
>  	memmove(buf, fdt, fdt_totalsize(fdt));

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

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