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c22ce143 HY |
1 | #ifndef __LINUX_UACCESS_H__ |
2 | #define __LINUX_UACCESS_H__ | |
3 | ||
4 | #include <asm/uaccess.h> | |
5 | ||
6 | #ifndef ARCH_HAS_NOCACHE_UACCESS | |
7 | ||
8 | static inline unsigned long __copy_from_user_inatomic_nocache(void *to, | |
9 | const void __user *from, unsigned long n) | |
10 | { | |
11 | return __copy_from_user_inatomic(to, from, n); | |
12 | } | |
13 | ||
14 | static inline unsigned long __copy_from_user_nocache(void *to, | |
15 | const void __user *from, unsigned long n) | |
16 | { | |
17 | return __copy_from_user(to, from, n); | |
18 | } | |
19 | ||
20 | #endif /* ARCH_HAS_NOCACHE_UACCESS */ | |
21 | ||
1b79e551 AM |
22 | /** |
23 | * probe_kernel_address(): safely attempt to read from a location | |
24 | * @addr: address to read from - its type is type typeof(retval)* | |
25 | * @retval: read into this variable | |
26 | * | |
27 | * Safely read from address @addr into variable @revtal. If a kernel fault | |
28 | * happens, handle that and return -EFAULT. | |
29 | * We ensure that the __get_user() is executed in atomic context so that | |
30 | * do_page_fault() doesn't attempt to take mmap_sem. This makes | |
31 | * probe_kernel_address() suitable for use within regions where the caller | |
32 | * already holds mmap_sem, or other locks which nest inside mmap_sem. | |
33 | */ | |
34 | #define probe_kernel_address(addr, retval) \ | |
35 | ({ \ | |
36 | long ret; \ | |
37 | \ | |
38 | inc_preempt_count(); \ | |
39 | ret = __get_user(retval, addr); \ | |
40 | dec_preempt_count(); \ | |
41 | ret; \ | |
42 | }) | |
43 | ||
c22ce143 | 44 | #endif /* __LINUX_UACCESS_H__ */ |