xref: /linux/arch/um/kernel/maccess.c (revision 56fb34d86e875dbb0d3e6a81c5d3d035db373031)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2013 Richard Weinberger <richrd@nod.at>
4  */
5 
6 #include <linux/uaccess.h>
7 #include <linux/kernel.h>
8 #include <os.h>
9 
10 long probe_kernel_read(void *dst, const void *src, size_t size)
11 {
12 	void *psrc = (void *)rounddown((unsigned long)src, PAGE_SIZE);
13 
14 	if ((unsigned long)src < PAGE_SIZE || size <= 0)
15 		return -EFAULT;
16 
17 	if (os_mincore(psrc, size + src - psrc) <= 0)
18 		return -EFAULT;
19 
20 	return __probe_kernel_read(dst, src, size);
21 }
22