static inline long do_syscall_stub()

in os-Linux/skas/mem.c [50:110]

• 49 lines of code
• 9 McCabe index (conditional complexity)

static inline long do_syscall_stub(struct mm_id * mm_idp, void **addr)
{
	int n, i;
	long ret, offset;
	unsigned long * data;
	unsigned long * syscall;
	int err, pid = mm_idp->u.pid;

	n = ptrace_setregs(pid, syscall_regs);
	if (n < 0) {
		printk(UM_KERN_ERR "Registers - \n");
		for (i = 0; i < MAX_REG_NR; i++)
			printk(UM_KERN_ERR "\t%d\t0x%lx\n", i, syscall_regs[i]);
		panic("do_syscall_stub : PTRACE_SETREGS failed, errno = %d\n",
		      -n);
	}

	err = ptrace(PTRACE_CONT, pid, 0, 0);
	if (err)
		panic("Failed to continue stub, pid = %d, errno = %d\n", pid,
		      errno);

	wait_stub_done(pid);

	/*
	 * When the stub stops, we find the following values on the
	 * beginning of the stack:
	 * (long )return_value
	 * (long )offset to failed sycall-data (0, if no error)
	 */
	ret = *((unsigned long *) mm_idp->stack);
	offset = *((unsigned long *) mm_idp->stack + 1);
	if (offset) {
		data = (unsigned long *)(mm_idp->stack + offset - STUB_DATA);
		printk(UM_KERN_ERR "do_syscall_stub : ret = %ld, offset = %ld, "
		       "data = %p\n", ret, offset, data);
		syscall = (unsigned long *)((unsigned long)data + data[0]);
		printk(UM_KERN_ERR "do_syscall_stub: syscall %ld failed, "
		       "return value = 0x%lx, expected return value = 0x%lx\n",
		       syscall[0], ret, syscall[7]);
		printk(UM_KERN_ERR "    syscall parameters: "
		       "0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
		       syscall[1], syscall[2], syscall[3],
		       syscall[4], syscall[5], syscall[6]);
		for (n = 1; n < data[0]/sizeof(long); n++) {
			if (n == 1)
				printk(UM_KERN_ERR "    additional syscall "
				       "data:");
			if (n % 4 == 1)
				printk("\n" UM_KERN_ERR "      ");
			printk("  0x%lx", data[n]);
		}
		if (n > 1)
			printk("\n");
	}
	else ret = 0;

	*addr = check_init_stack(mm_idp, NULL);

	return ret;
}