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/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* OpenRISC Linux
*
* Linux architectural port borrowing liberally from similar works of
* others. All original copyrights apply as per the original source
* declaration.
*
* OpenRISC implementation:
* Copyright (C) 2003 Matjaz Breskvar <[email protected]>
* Copyright (C) 2010-2011 Jonas Bonn <[email protected]>
* et al.
*/
#ifndef __ASM_OPENRISC_UACCESS_H
#define __ASM_OPENRISC_UACCESS_H
/*
* User space memory access functions
*/
#include <linux/prefetch.h>
#include <linux/string.h>
#include <asm/page.h>
#include <asm/extable.h>
/*
* The fs value determines whether argument validity checking should be
* performed or not. If get_fs() == USER_DS, checking is performed, with
* get_fs() == KERNEL_DS, checking is bypassed.
*
* For historical reasons, these macros are grossly misnamed.
*/
/* addr_limit is the maximum accessible address for the task. we misuse
* the KERNEL_DS and USER_DS values to both assign and compare the
* addr_limit values through the equally misnamed get/set_fs macros.
* (see above)
*/
#define KERNEL_DS (~0UL)
#define USER_DS (TASK_SIZE)
#define get_fs() (current_thread_info()->addr_limit)
#define set_fs(x) (current_thread_info()->addr_limit = (x))
#define uaccess_kernel() (get_fs() == KERNEL_DS)
/* Ensure that the range from addr to addr+size is all within the process'
* address space
*/
static inline int __range_ok(unsigned long addr, unsigned long size)
{
const mm_segment_t fs = get_fs();
return size <= fs && addr <= (fs - size);
}
#define access_ok(addr, size) \
({ \
__chk_user_ptr(addr); \
__range_ok((unsigned long)(addr), (size)); \
})
/*
* These are the main single-value transfer routines. They automatically
* use the right size if we just have the right pointer type.
*
* This gets kind of ugly. We want to return _two_ values in "get_user()"
* and yet we don't want to do any pointers, because that is too much
* of a performance impact. Thus we have a few rather ugly macros here,
* and hide all the uglyness from the user.
*
* The "__xxx" versions of the user access functions are versions that
* do not verify the address space, that must have been done previously
* with a separate "access_ok()" call (this is used when we do multiple
* accesses to the same area of user memory).
*
* As we use the same address space for kernel and user data on the
* PowerPC, we can just do these as direct assignments. (Of course, the
* exception handling means that it's no longer "just"...)
*/
#define get_user(x, ptr) \
__get_user_check((x), (ptr), sizeof(*(ptr)))
#define put_user(x, ptr) \
__put_user_check((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
#define __get_user(x, ptr) \
__get_user_nocheck((x), (ptr), sizeof(*(ptr)))
#define __put_user(x, ptr) \
__put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
extern long __put_user_bad(void);
#define __put_user_nocheck(x, ptr, size) \
({ \
long __pu_err; \
__put_user_size((x), (ptr), (size), __pu_err); \
__pu_err; \
})
#define __put_user_check(x, ptr, size) \
({ \
long __pu_err = -EFAULT; \
__typeof__(*(ptr)) __user *__pu_addr = (ptr); \
if (access_ok(__pu_addr, size)) \
__put_user_size((x), __pu_addr, (size), __pu_err); \
__pu_err; \
})
#define __put_user_size(x, ptr, size, retval) \
do { \
retval = 0; \
switch (size) { \
case 1: __put_user_asm(x, ptr, retval, "l.sb"); break; \
case 2: __put_user_asm(x, ptr, retval, "l.sh"); break; \
case 4: __put_user_asm(x, ptr, retval, "l.sw"); break; \
case 8: __put_user_asm2(x, ptr, retval); break; \
default: __put_user_bad(); \
} \
} while (0)
struct __large_struct {
unsigned long buf[100];
};
#define __m(x) (*(struct __large_struct *)(x))
/*
* We don't tell gcc that we are accessing memory, but this is OK
* because we do not write to any memory gcc knows about, so there
* are no aliasing issues.
*/
#define __put_user_asm(x, addr, err, op) \
__asm__ __volatile__( \
"1: "op" 0(%2),%1\n" \
"2:\n" \
".section .fixup,\"ax\"\n" \
"3: l.addi %0,r0,%3\n" \
" l.j 2b\n" \
" l.nop\n" \
".previous\n" \
".section __ex_table,\"a\"\n" \
" .align 2\n" \
" .long 1b,3b\n" \
".previous" \
: "=r"(err) \
: "r"(x), "r"(addr), "i"(-EFAULT), "0"(err))
#define __put_user_asm2(x, addr, err) \
__asm__ __volatile__( \
"1: l.sw 0(%2),%1\n" \
"2: l.sw 4(%2),%H1\n" \
"3:\n" \
".section .fixup,\"ax\"\n" \
"4: l.addi %0,r0,%3\n" \
" l.j 3b\n" \
" l.nop\n" \
".previous\n" \
".section __ex_table,\"a\"\n" \
" .align 2\n" \
" .long 1b,4b\n" \
" .long 2b,4b\n" \
".previous" \
: "=r"(err) \
: "r"(x), "r"(addr), "i"(-EFAULT), "0"(err))
#define __get_user_nocheck(x, ptr, size) \
({ \
long __gu_err; \
__get_user_size((x), (ptr), (size), __gu_err); \
__gu_err; \
})
#define __get_user_check(x, ptr, size) \
({ \
long __gu_err = -EFAULT; \
const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \
if (access_ok(__gu_addr, size)) \
__get_user_size((x), __gu_addr, (size), __gu_err); \
else \
(x) = (__typeof__(*(ptr))) 0; \
__gu_err; \
})
extern long __get_user_bad(void);
#define __get_user_size(x, ptr, size, retval) \
do { \
retval = 0; \
switch (size) { \
case 1: __get_user_asm(x, ptr, retval, "l.lbz"); break; \
case 2: __get_user_asm(x, ptr, retval, "l.lhz"); break; \
case 4: __get_user_asm(x, ptr, retval, "l.lwz"); break; \
case 8: __get_user_asm2(x, ptr, retval); break; \
default: (x) = (__typeof__(*(ptr)))__get_user_bad(); \
} \
} while (0)
#define __get_user_asm(x, addr, err, op) \
{ \
unsigned long __gu_tmp; \
__asm__ __volatile__( \
"1: "op" %1,0(%2)\n" \
"2:\n" \
".section .fixup,\"ax\"\n" \
"3: l.addi %0,r0,%3\n" \
" l.addi %1,r0,0\n" \
" l.j 2b\n" \
" l.nop\n" \
".previous\n" \
".section __ex_table,\"a\"\n" \
" .align 2\n" \
" .long 1b,3b\n" \
".previous" \
: "=r"(err), "=r"(__gu_tmp) \
: "r"(addr), "i"(-EFAULT), "0"(err)); \
(x) = (__typeof__(*(addr)))__gu_tmp; \
}
#define __get_user_asm2(x, addr, err) \
{ \
unsigned long long __gu_tmp; \
__asm__ __volatile__( \
"1: l.lwz %1,0(%2)\n" \
"2: l.lwz %H1,4(%2)\n" \
"3:\n" \
".section .fixup,\"ax\"\n" \
"4: l.addi %0,r0,%3\n" \
" l.addi %1,r0,0\n" \
" l.addi %H1,r0,0\n" \
" l.j 3b\n" \
" l.nop\n" \
".previous\n" \
".section __ex_table,\"a\"\n" \
" .align 2\n" \
" .long 1b,4b\n" \
" .long 2b,4b\n" \
".previous" \
: "=r"(err), "=&r"(__gu_tmp) \
: "r"(addr), "i"(-EFAULT), "0"(err)); \
(x) = (__typeof__(*(addr)))( \
(__typeof__((x)-(x)))__gu_tmp); \
}
/* more complex routines */
extern unsigned long __must_check
__copy_tofrom_user(void *to, const void *from, unsigned long size);
static inline unsigned long
raw_copy_from_user(void *to, const void __user *from, unsigned long size)
{
return __copy_tofrom_user(to, (__force const void *)from, size);
}
static inline unsigned long
raw_copy_to_user(void __user *to, const void *from, unsigned long size)
{
return __copy_tofrom_user((__force void *)to, from, size);
}
#define INLINE_COPY_FROM_USER
#define INLINE_COPY_TO_USER
extern unsigned long __clear_user(void __user *addr, unsigned long size);
static inline __must_check unsigned long
clear_user(void __user *addr, unsigned long size)
{
if (likely(access_ok(addr, size)))
size = __clear_user(addr, size);
return size;
}
#define user_addr_max() \
(uaccess_kernel() ? ~0UL : TASK_SIZE)
extern long strncpy_from_user(char *dest, const char __user *src, long count);
extern __must_check long strnlen_user(const char __user *str, long n);
#endif /* __ASM_OPENRISC_UACCESS_H */
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