]>
git.proxmox.com Git - mirror_ubuntu-jammy-kernel.git/blob - arch/hexagon/include/asm/uaccess.h
2 * User memory access support for Hexagon
4 * Copyright (c) 2010-2011, The Linux Foundation. All rights reserved.
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 and
8 * only version 2 as published by the Free Software Foundation.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
21 #ifndef _ASM_UACCESS_H
22 #define _ASM_UACCESS_H
24 * User space memory access functions
27 #include <asm/sections.h>
30 * access_ok: - Checks if a user space pointer is valid
31 * @addr: User space pointer to start of block to check
32 * @size: Size of block to check
34 * Context: User context only. This function may sleep if pagefaults are
37 * Checks if a pointer to a block of memory in user space is valid.
39 * Returns true (nonzero) if the memory block *may* be valid, false (zero)
40 * if it is definitely invalid.
42 * User address space in Hexagon, like x86, goes to 0xbfffffff, so the
43 * simple MSB-based tests used by MIPS won't work. Some further
44 * optimization is probably possible here, but for now, keep it
45 * reasonably simple and not *too* slow. After all, we've got the
49 #define __access_ok(addr, size) \
50 ((get_fs().seg == KERNEL_DS.seg) || \
51 (((unsigned long)addr < get_fs().seg) && \
52 (unsigned long)size < (get_fs().seg - (unsigned long)addr)))
55 * When a kernel-mode page fault is taken, the faulting instruction
56 * address is checked against a table of exception_table_entries.
57 * Each entry is a tuple of the address of an instruction that may
58 * be authorized to fault, and the address at which execution should
59 * be resumed instead of the faulting instruction, so as to effect
63 /* Assembly somewhat optimized copy routines */
64 unsigned long raw_copy_from_user(void *to
, const void __user
*from
,
66 unsigned long raw_copy_to_user(void __user
*to
, const void *from
,
68 #define INLINE_COPY_FROM_USER
69 #define INLINE_COPY_TO_USER
71 __kernel_size_t
__clear_user_hexagon(void __user
*dest
, unsigned long count
);
72 #define __clear_user(a, s) __clear_user_hexagon((a), (s))
74 #define __strncpy_from_user(dst, src, n) hexagon_strncpy_from_user(dst, src, n)
76 /* get around the ifndef in asm-generic/uaccess.h */
77 #define __strnlen_user __strnlen_user
79 extern long __strnlen_user(const char __user
*src
, long n
);
81 static inline long hexagon_strncpy_from_user(char *dst
, const char __user
*src
,
84 #include <asm-generic/uaccess.h>
86 /* Todo: an actual accelerated version of this. */
87 static inline long hexagon_strncpy_from_user(char *dst
, const char __user
*src
,
90 long res
= __strnlen_user(src
, n
);
96 long left
= raw_copy_from_user(dst
, src
, n
);
98 memset(dst
+ (n
- left
), 0, left
);
101 long left
= raw_copy_from_user(dst
, src
, res
);
103 memset(dst
+ (res
- left
), 0, left
);