mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-12 20:46:49 +07:00
1b79e5513d
Add a version of __get_user() which is safe to call inside mmap_sem. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
45 lines
1.3 KiB
C
45 lines
1.3 KiB
C
#ifndef __LINUX_UACCESS_H__
|
|
#define __LINUX_UACCESS_H__
|
|
|
|
#include <asm/uaccess.h>
|
|
|
|
#ifndef ARCH_HAS_NOCACHE_UACCESS
|
|
|
|
static inline unsigned long __copy_from_user_inatomic_nocache(void *to,
|
|
const void __user *from, unsigned long n)
|
|
{
|
|
return __copy_from_user_inatomic(to, from, n);
|
|
}
|
|
|
|
static inline unsigned long __copy_from_user_nocache(void *to,
|
|
const void __user *from, unsigned long n)
|
|
{
|
|
return __copy_from_user(to, from, n);
|
|
}
|
|
|
|
#endif /* ARCH_HAS_NOCACHE_UACCESS */
|
|
|
|
/**
|
|
* probe_kernel_address(): safely attempt to read from a location
|
|
* @addr: address to read from - its type is type typeof(retval)*
|
|
* @retval: read into this variable
|
|
*
|
|
* Safely read from address @addr into variable @revtal. If a kernel fault
|
|
* happens, handle that and return -EFAULT.
|
|
* We ensure that the __get_user() is executed in atomic context so that
|
|
* do_page_fault() doesn't attempt to take mmap_sem. This makes
|
|
* probe_kernel_address() suitable for use within regions where the caller
|
|
* already holds mmap_sem, or other locks which nest inside mmap_sem.
|
|
*/
|
|
#define probe_kernel_address(addr, retval) \
|
|
({ \
|
|
long ret; \
|
|
\
|
|
inc_preempt_count(); \
|
|
ret = __get_user(retval, addr); \
|
|
dec_preempt_count(); \
|
|
ret; \
|
|
})
|
|
|
|
#endif /* __LINUX_UACCESS_H__ */
|