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/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (C) 2020-2022 Loongson Technology Corporation Limited
*
* Derived from MIPS:
* Copyright (C) 1996, 1997, 1998, 1999, 2000, 03, 04 by Ralf Baechle
* Copyright (C) 1999, 2000 Silicon Graphics, Inc.
* Copyright (C) 2007 Maciej W. Rozycki
* Copyright (C) 2014, Imagination Technologies Ltd.
*/
#ifndef _ASM_UACCESS_H
#define _ASM_UACCESS_H
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/extable.h>
#include <asm/pgtable.h>
#include <asm/extable.h>
#include <asm/asm-extable.h>
#include <asm-generic/access_ok.h>
extern u64 __ua_limit;
#define __UA_ADDR ".dword"
#define __UA_LA "la.abs"
#define __UA_LIMIT __ua_limit
/*
* get_user: - Get a simple variable from user space.
* @x: Variable to store result.
* @ptr: Source address, in user space.
*
* Context: User context only. This function may sleep if pagefaults are
* enabled.
*
* This macro copies a single simple variable from user space to kernel
* space. It supports simple types like char and int, but not larger
* data types like structures or arrays.
*
* @ptr must have pointer-to-simple-variable type, and the result of
* dereferencing @ptr must be assignable to @x without a cast.
*
* Returns zero on success, or -EFAULT on error.
* On error, the variable @x is set to zero.
*/
#define get_user(x, ptr) \
({ \
const __typeof__(*(ptr)) __user *__p = (ptr); \
\
might_fault(); \
access_ok(__p, sizeof(*__p)) ? __get_user((x), __p) : \
((x) = 0, -EFAULT); \
})
/*
* put_user: - Write a simple value into user space.
* @x: Value to copy to user space.
* @ptr: Destination address, in user space.
*
* Context: User context only. This function may sleep if pagefaults are
* enabled.
*
* This macro copies a single simple value from kernel space to user
* space. It supports simple types like char and int, but not larger
* data types like structures or arrays.
*
* @ptr must have pointer-to-simple-variable type, and @x must be assignable
* to the result of dereferencing @ptr.
*
* Returns zero on success, or -EFAULT on error.
*/
#define put_user(x, ptr) \
({ \
__typeof__(*(ptr)) __user *__p = (ptr); \
\
might_fault(); \
access_ok(__p, sizeof(*__p)) ? __put_user((x), __p) : -EFAULT; \
})
/*
* __get_user: - Get a simple variable from user space, with less checking.
* @x: Variable to store result.
* @ptr: Source address, in user space.
*
* Context: User context only. This function may sleep if pagefaults are
* enabled.
*
* This macro copies a single simple variable from user space to kernel
* space. It supports simple types like char and int, but not larger
* data types like structures or arrays.
*
* @ptr must have pointer-to-simple-variable type, and the result of
* dereferencing @ptr must be assignable to @x without a cast.
*
* Caller must check the pointer with access_ok() before calling this
* function.
*
* Returns zero on success, or -EFAULT on error.
* On error, the variable @x is set to zero.
*/
#define __get_user(x, ptr) \
({ \
int __gu_err = 0; \
\
__chk_user_ptr(ptr); \
__get_user_common((x), sizeof(*(ptr)), ptr); \
__gu_err; \
})
/*
* __put_user: - Write a simple value into user space, with less checking.
* @x: Value to copy to user space.
* @ptr: Destination address, in user space.
*
* Context: User context only. This function may sleep if pagefaults are
* enabled.
*
* This macro copies a single simple value from kernel space to user
* space. It supports simple types like char and int, but not larger
* data types like structures or arrays.
*
* @ptr must have pointer-to-simple-variable type, and @x must be assignable
* to the result of dereferencing @ptr.
*
* Caller must check the pointer with access_ok() before calling this
* function.
*
* Returns zero on success, or -EFAULT on error.
*/
#define __put_user(x, ptr) \
({ \
int __pu_err = 0; \
__typeof__(*(ptr)) __pu_val; \
\
__pu_val = (x); \
__chk_user_ptr(ptr); \
__put_user_common(ptr, sizeof(*(ptr))); \
__pu_err; \
})
struct __large_struct { unsigned long buf[100]; };
#define __m(x) (*(struct __large_struct __user *)(x))
#define __get_user_common(val, size, ptr) \
do { \
switch (size) { \
case 1: __get_data_asm(val, "ld.b", ptr); break; \
case 2: __get_data_asm(val, "ld.h", ptr); break; \
case 4: __get_data_asm(val, "ld.w", ptr); break; \
case 8: __get_data_asm(val, "ld.d", ptr); break; \
default: BUILD_BUG(); break; \
} \
} while (0)
#define __get_kernel_common(val, size, ptr) __get_user_common(val, size, ptr)
#define __get_data_asm(val, insn, ptr) \
{ \
long __gu_tmp; \
\
__asm__ __volatile__( \
"1: " insn " %1, %2 \n" \
"2: \n" \
_ASM_EXTABLE_UACCESS_ERR_ZERO(1b, 2b, %0, %1) \
: "+r" (__gu_err), "=r" (__gu_tmp) \
: "m" (__m(ptr))); \
\
(val) = (__typeof__(*(ptr))) __gu_tmp; \
}
#define __put_user_common(ptr, size) \
do { \
switch (size) { \
case 1: __put_data_asm("st.b", ptr); break; \
case 2: __put_data_asm("st.h", ptr); break; \
case 4: __put_data_asm("st.w", ptr); break; \
case 8: __put_data_asm("st.d", ptr); break; \
default: BUILD_BUG(); break; \
} \
} while (0)
#define __put_kernel_common(ptr, size) __put_user_common(ptr, size)
#define __put_data_asm(insn, ptr) \
{ \
__asm__ __volatile__( \
"1: " insn " %z2, %1 # __put_user_asm\n" \
"2: \n" \
_ASM_EXTABLE_UACCESS_ERR(1b, 2b, %0) \
: "+r" (__pu_err), "=m" (__m(ptr)) \
: "Jr" (__pu_val)); \
}
#define __get_kernel_nofault(dst, src, type, err_label) \
do { \
int __gu_err = 0; \
\
__get_kernel_common(*((type *)(dst)), sizeof(type), \
(__force type *)(src)); \
if (unlikely(__gu_err)) \
goto err_label; \
} while (0)
#define __put_kernel_nofault(dst, src, type, err_label) \
do { \
type __pu_val; \
int __pu_err = 0; \
\
__pu_val = *(__force type *)(src); \
__put_kernel_common(((type *)(dst)), sizeof(type)); \
if (unlikely(__pu_err)) \
goto err_label; \
} while (0)
extern unsigned long __copy_user(void *to, const void *from, __kernel_size_t n);
static inline unsigned long __must_check
raw_copy_from_user(void *to, const void __user *from, unsigned long n)
{
return __copy_user(to, (__force const void *)from, n);
}
static inline unsigned long __must_check
raw_copy_to_user(void __user *to, const void *from, unsigned long n)
{
return __copy_user((__force void *)to, from, n);
}
#define INLINE_COPY_FROM_USER
#define INLINE_COPY_TO_USER
/*
* __clear_user: - Zero a block of memory in user space, with less checking.
* @addr: Destination address, in user space.
* @size: Number of bytes to zero.
*
* Zero a block of memory in user space. Caller must check
* the specified block with access_ok() before calling this function.
*
* Returns number of bytes that could not be cleared.
* On success, this will be zero.
*/
extern unsigned long __clear_user(void __user *addr, __kernel_size_t size);
#define clear_user(addr, n) \
({ \
void __user *__cl_addr = (addr); \
unsigned long __cl_size = (n); \
if (__cl_size && access_ok(__cl_addr, __cl_size)) \
__cl_size = __clear_user(__cl_addr, __cl_size); \
__cl_size; \
})
extern long strncpy_from_user(char *to, const char __user *from, long n);
extern long strnlen_user(const char __user *str, long n);
#endif /* _ASM_UACCESS_H */
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