xref: /openbmc/linux/arch/um/kernel/maccess.c (revision 293d5b43)
1 /*
2  * Copyright (C) 2013 Richard Weinberger <richrd@nod.at>
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2 as
6  * published by the Free Software Foundation.
7  */
8 
9 #include <linux/uaccess.h>
10 #include <linux/kernel.h>
11 #include <os.h>
12 
13 long probe_kernel_read(void *dst, const void *src, size_t size)
14 {
15 	void *psrc = (void *)rounddown((unsigned long)src, PAGE_SIZE);
16 
17 	if ((unsigned long)src < PAGE_SIZE || size <= 0)
18 		return -EFAULT;
19 
20 	if (os_mincore(psrc, size + src - psrc) <= 0)
21 		return -EFAULT;
22 
23 	return __probe_kernel_read(dst, src, size);
24 }
25