static void do_fpregs_set()

in kernel/ptrace.c [1609:1680]

• 63 lines of code
• 19 McCabe index (conditional complexity)

static void do_fpregs_set(struct unw_frame_info *info, void *arg)
{
	struct regset_getset *dst = arg;
	elf_fpreg_t fpreg, tmp[30];
	int index, start, end;

	if (unw_unwind_to_user(info) < 0)
		return;

	/* Skip pos 0 and 1 */
	if (dst->count > 0 && dst->pos < ELF_FP_OFFSET(2)) {
		dst->ret = user_regset_copyin_ignore(&dst->pos, &dst->count,
						       &dst->u.set.kbuf,
						       &dst->u.set.ubuf,
						       0, ELF_FP_OFFSET(2));
		if (dst->count == 0 || dst->ret)
			return;
	}

	/* fr2-fr31 */
	if (dst->count > 0 && dst->pos < ELF_FP_OFFSET(32)) {
		start = dst->pos;
		end = min(((unsigned int)ELF_FP_OFFSET(32)),
			 dst->pos + dst->count);
		dst->ret = user_regset_copyin(&dst->pos, &dst->count,
				&dst->u.set.kbuf, &dst->u.set.ubuf, tmp,
				ELF_FP_OFFSET(2), ELF_FP_OFFSET(32));
		if (dst->ret)
			return;

		if (start & 0xF) { /* only write high part */
			if (unw_get_fr(info, start / sizeof(elf_fpreg_t),
					 &fpreg)) {
				dst->ret = -EIO;
				return;
			}
			tmp[start / sizeof(elf_fpreg_t) - 2].u.bits[0]
				= fpreg.u.bits[0];
			start &= ~0xFUL;
		}
		if (end & 0xF) { /* only write low part */
			if (unw_get_fr(info, end / sizeof(elf_fpreg_t),
					&fpreg)) {
				dst->ret = -EIO;
				return;
			}
			tmp[end / sizeof(elf_fpreg_t) - 2].u.bits[1]
				= fpreg.u.bits[1];
			end = (end + 0xF) & ~0xFUL;
		}

		for ( ;	start < end ; start += sizeof(elf_fpreg_t)) {
			index = start / sizeof(elf_fpreg_t);
			if (unw_set_fr(info, index, tmp[index - 2])) {
				dst->ret = -EIO;
				return;
			}
		}
		if (dst->ret || dst->count == 0)
			return;
	}

	/* fph */
	if (dst->count > 0 && dst->pos < ELF_FP_OFFSET(128)) {
		ia64_sync_fph(dst->target);
		dst->ret = user_regset_copyin(&dst->pos, &dst->count,
						&dst->u.set.kbuf,
						&dst->u.set.ubuf,
						&dst->target->thread.fph,
						ELF_FP_OFFSET(32), -1);
	}
}