static int gpr_set()

in kernel/ptrace.c [68:118]

• 43 lines of code
• 7 McCabe index (conditional complexity)

static int gpr_set(struct task_struct *target,
		   const struct user_regset *regset,
		   unsigned int pos, unsigned int count,
		   const void *kbuf, const void __user *ubuf)
{
	int ret;
	struct user_pt_regs newregs = {0};
	struct pt_regs *regs;
	const u32 ps_mask = PS_CALLINC_MASK | PS_OWB_MASK;

	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &newregs, 0, -1);
	if (ret)
		return ret;

	if (newregs.windowbase >= XCHAL_NUM_AREGS / 4)
		return -EINVAL;

	regs = task_pt_regs(target);
	regs->pc = newregs.pc;
	regs->ps = (regs->ps & ~ps_mask) | (newregs.ps & ps_mask);
	regs->lbeg = newregs.lbeg;
	regs->lend = newregs.lend;
	regs->lcount = newregs.lcount;
	regs->sar = newregs.sar;
	regs->threadptr = newregs.threadptr;

	if (newregs.syscall)
		regs->syscall = newregs.syscall;

	if (newregs.windowbase != regs->windowbase ||
	    newregs.windowstart != regs->windowstart) {
		u32 rotws, wmask;

		rotws = (((newregs.windowstart |
			   (newregs.windowstart << WSBITS)) >>
			  newregs.windowbase) &
			 ((1 << WSBITS) - 1)) & ~1;
		wmask = ((rotws ? WSBITS + 1 - ffs(rotws) : 0) << 4) |
			(rotws & 0xF) | 1;
		regs->windowbase = newregs.windowbase;
		regs->windowstart = newregs.windowstart;
		regs->wmask = wmask;
	}

	memcpy(regs->areg + XCHAL_NUM_AREGS - newregs.windowbase * 4,
	       newregs.a, newregs.windowbase * 16);
	memcpy(regs->areg, newregs.a + newregs.windowbase * 4,
	       (WSBITS - newregs.windowbase) * 16);

	return 0;
}