[coreboot] r3519 - trunk/payloads/libpayload/libc

[Ulf Jordan]

On Tue, 19 Aug 2008, svn at coreboot.org wrote:

[snip]

> void *memcpy(void *dst, const void *src, size_t n)
> {
> -	int i, j;
> +	int i;
>
> -	if (((long)dst & (sizeof(long) - 1))
> -	    || ((long)src & (sizeof(long) - 1)))
> -		return unaligned_memcpy(dst, src, n);
> +	for(i = 0; i < n % sizeof(unsigned long); i++)
> +		((unsigned char *) dst)[i] = ((unsigned char *) src)[i];
>
> -	for (i = 0; i < n / sizeof(unsigned long); i++)
> -		((unsigned long *)dst)[i] = ((unsigned long *)src)[i];
> +	n -= i;
> +	src += i;
> +	dst += i;
>
> -	for (j = 0; j < n % sizeof(unsigned long); j++)
> -		((unsigned char *)(((unsigned long *)dst) + i))[j] =
> -		    ((unsigned char *)(((unsigned long *)src) + i))[j];
> +	for(i = 0; i < n / sizeof(unsigned long); i++)
> +		((unsigned long *) dst)[i] = ((unsigned long *) src)[i];
>
> -	return (char *)src;
> +	return dst;
> }

Does this really return the correct value?

When I read the Linux memcpy(3) man page and the GNU C library reference
manual I get the impression that the return value should be the original
value of dst. This implementation returns a value which is original dst+0,
1, 2, or 3, depending on n % sizeof(unsigned long).


/ulf