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

[Ulf Jordan]

On Tue, 19 Aug 2008, [e-mail] 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