Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1#ifndef __LINUX_UACCESS_H__
2#define __LINUX_UACCESS_H__
3
4#include <asm/uaccess.h>
5
6#ifndef ARCH_HAS_NOCACHE_UACCESS
7
8static 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
14static 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
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
44#endif /* __LINUX_UACCESS_H__ */