long arch_ptrace()

in kernel/ptrace.c [44:113]

• 61 lines of code
• 14 McCabe index (conditional complexity)

long arch_ptrace(struct task_struct *child, long request,
		 unsigned long addr, unsigned long data)
{
	int i, ret;
	unsigned long __user *p = (void __user *)data;
	void __user *vp = p;

	switch (request) {
	/* read the word at location addr in the USER area. */
	case PTRACE_PEEKUSR:
		ret = peek_user(child, addr, data);
		break;

	/* write the word at location addr in the USER area */
	case PTRACE_POKEUSR:
		ret = poke_user(child, addr, data);
		break;

	case PTRACE_SYSEMU:
	case PTRACE_SYSEMU_SINGLESTEP:
		ret = -EIO;
		break;

#ifdef PTRACE_GETREGS
	case PTRACE_GETREGS: { /* Get all gp regs from the child. */
		if (!access_ok(p, MAX_REG_OFFSET)) {
			ret = -EIO;
			break;
		}
		for ( i = 0; i < MAX_REG_OFFSET; i += sizeof(long) ) {
			__put_user(getreg(child, i), p);
			p++;
		}
		ret = 0;
		break;
	}
#endif
#ifdef PTRACE_SETREGS
	case PTRACE_SETREGS: { /* Set all gp regs in the child. */
		unsigned long tmp = 0;
		if (!access_ok(p, MAX_REG_OFFSET)) {
			ret = -EIO;
			break;
		}
		for ( i = 0; i < MAX_REG_OFFSET; i += sizeof(long) ) {
			__get_user(tmp, p);
			putreg(child, i, tmp);
			p++;
		}
		ret = 0;
		break;
	}
#endif
	case PTRACE_GET_THREAD_AREA:
		ret = ptrace_get_thread_area(child, addr, vp);
		break;

	case PTRACE_SET_THREAD_AREA:
		ret = ptrace_set_thread_area(child, addr, vp);
		break;

	default:
		ret = ptrace_request(child, request, addr, data);
		if (ret == -EIO)
			ret = subarch_ptrace(child, request, addr, data);
		break;
	}

	return ret;
}