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// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2005-2017 Andes Technology Corporation
#ifndef _ASMANDES_UACCESS_H
#define _ASMANDES_UACCESS_H
/*
* User space memory access functions
*/
#include <linux/sched.h>
#include <asm/errno.h>
#include <asm/memory.h>
#include <asm/types.h>
#include <linux/mm.h>
#define VERIFY_READ 0
#define VERIFY_WRITE 1
#define __asmeq(x, y) ".ifnc " x "," y " ; .err ; .endif\n\t"
/*
* The exception table consists of pairs of addresses: the first is the
* address of an instruction that is allowed to fault, and the second is
* the address at which the program should continue. No registers are
* modified, so it is entirely up to the continuation code to figure out
* what to do.
*
* All the routines below use bits of fixup code that are out of line
* with the main instruction path. This means when everything is well,
* we don't even have to jump over them. Further, they do not intrude
* on our cache or tlb entries.
*/
struct exception_table_entry {
unsigned long insn, fixup;
};
extern int fixup_exception(struct pt_regs *regs);
#define KERNEL_DS ((mm_segment_t) { ~0UL })
#define USER_DS ((mm_segment_t) {TASK_SIZE - 1})
#define get_ds() (KERNEL_DS)
#define get_fs() (current_thread_info()->addr_limit)
#define user_addr_max get_fs
static inline void set_fs(mm_segment_t fs)
{
current_thread_info()->addr_limit = fs;
}
#define segment_eq(a, b) ((a) == (b))
#define __range_ok(addr, size) (size <= get_fs() && addr <= (get_fs() -size))
#define access_ok(type, addr, size) \
__range_ok((unsigned long)addr, (unsigned long)size)
/*
* Single-value transfer routines. They automatically use the right
* size if we just have the right pointer type. Note that the functions
* which read from user space (*get_*) need to take care not to leak
* kernel data even if the calling code is buggy and fails to check
* the return value. This means zeroing out the destination variable
* or buffer on error. Normally this is done out of line by the
* fixup code, but there are a few places where it intrudes on the
* main code path. When we only write to user space, there is no
* problem.
*
* The "__xxx" versions of the user access functions do not verify the
* address space - it must have been done previously with a separate
* "access_ok()" call.
*
* The "xxx_error" versions set the third argument to EFAULT if an
* error occurs, and leave it unchanged on success. Note that these
* versions are void (ie, don't return a value as such).
*/
#define get_user(x,p) \
({ \
long __e = -EFAULT; \
if(likely(access_ok(VERIFY_READ, p, sizeof(*p)))) { \
__e = __get_user(x,p); \
} else \
x = 0; \
__e; \
})
#define __get_user(x,ptr) \
({ \
long __gu_err = 0; \
__get_user_err((x),(ptr),__gu_err); \
__gu_err; \
})
#define __get_user_error(x,ptr,err) \
({ \
__get_user_err((x),(ptr),err); \
(void) 0; \
})
#define __get_user_err(x,ptr,err) \
do { \
unsigned long __gu_addr = (unsigned long)(ptr); \
unsigned long __gu_val; \
__chk_user_ptr(ptr); \
switch (sizeof(*(ptr))) { \
case 1: \
__get_user_asm("lbi",__gu_val,__gu_addr,err); \
break; \
case 2: \
__get_user_asm("lhi",__gu_val,__gu_addr,err); \
break; \
case 4: \
__get_user_asm("lwi",__gu_val,__gu_addr,err); \
break; \
case 8: \
__get_user_asm_dword(__gu_val,__gu_addr,err); \
break; \
default: \
BUILD_BUG(); \
break; \
} \
(x) = (__typeof__(*(ptr)))__gu_val; \
} while (0)
#define __get_user_asm(inst,x,addr,err) \
asm volatile( \
"1: "inst" %1,[%2]\n" \
"2:\n" \
" .section .fixup,\"ax\"\n" \
" .align 2\n" \
"3: move %0, %3\n" \
" move %1, #0\n" \
" b 2b\n" \
" .previous\n" \
" .section __ex_table,\"a\"\n" \
" .align 3\n" \
" .long 1b, 3b\n" \
" .previous" \
: "+r" (err), "=&r" (x) \
: "r" (addr), "i" (-EFAULT) \
: "cc")
#ifdef __NDS32_EB__
#define __gu_reg_oper0 "%H1"
#define __gu_reg_oper1 "%L1"
#else
#define __gu_reg_oper0 "%L1"
#define __gu_reg_oper1 "%H1"
#endif
#define __get_user_asm_dword(x, addr, err) \
asm volatile( \
"\n1:\tlwi " __gu_reg_oper0 ",[%2]\n" \
"\n2:\tlwi " __gu_reg_oper1 ",[%2+4]\n" \
"3:\n" \
" .section .fixup,\"ax\"\n" \
" .align 2\n" \
"4: move %0, %3\n" \
" b 3b\n" \
" .previous\n" \
" .section __ex_table,\"a\"\n" \
" .align 3\n" \
" .long 1b, 4b\n" \
" .long 2b, 4b\n" \
" .previous" \
: "+r"(err), "=&r"(x) \
: "r"(addr), "i"(-EFAULT) \
: "cc")
#define put_user(x,p) \
({ \
long __e = -EFAULT; \
if(likely(access_ok(VERIFY_WRITE, p, sizeof(*p)))) { \
__e = __put_user(x,p); \
} \
__e; \
})
#define __put_user(x,ptr) \
({ \
long __pu_err = 0; \
__put_user_err((x),(ptr),__pu_err); \
__pu_err; \
})
#define __put_user_error(x,ptr,err) \
({ \
__put_user_err((x),(ptr),err); \
(void) 0; \
})
#define __put_user_err(x,ptr,err) \
do { \
unsigned long __pu_addr = (unsigned long)(ptr); \
__typeof__(*(ptr)) __pu_val = (x); \
__chk_user_ptr(ptr); \
switch (sizeof(*(ptr))) { \
case 1: \
__put_user_asm("sbi",__pu_val,__pu_addr,err); \
break; \
case 2: \
__put_user_asm("shi",__pu_val,__pu_addr,err); \
break; \
case 4: \
__put_user_asm("swi",__pu_val,__pu_addr,err); \
break; \
case 8: \
__put_user_asm_dword(__pu_val,__pu_addr,err); \
break; \
default: \
BUILD_BUG(); \
break; \
} \
} while (0)
#define __put_user_asm(inst,x,addr,err) \
asm volatile( \
"1: "inst" %1,[%2]\n" \
"2:\n" \
" .section .fixup,\"ax\"\n" \
" .align 2\n" \
"3: move %0, %3\n" \
" b 2b\n" \
" .previous\n" \
" .section __ex_table,\"a\"\n" \
" .align 3\n" \
" .long 1b, 3b\n" \
" .previous" \
: "+r" (err) \
: "r" (x), "r" (addr), "i" (-EFAULT) \
: "cc")
#ifdef __NDS32_EB__
#define __pu_reg_oper0 "%H2"
#define __pu_reg_oper1 "%L2"
#else
#define __pu_reg_oper0 "%L2"
#define __pu_reg_oper1 "%H2"
#endif
#define __put_user_asm_dword(x, addr, err) \
asm volatile( \
"\n1:\tswi " __pu_reg_oper0 ",[%1]\n" \
"\n2:\tswi " __pu_reg_oper1 ",[%1+4]\n" \
"3:\n" \
" .section .fixup,\"ax\"\n" \
" .align 2\n" \
"4: move %0, %3\n" \
" b 3b\n" \
" .previous\n" \
" .section __ex_table,\"a\"\n" \
" .align 3\n" \
" .long 1b, 4b\n" \
" .long 2b, 4b\n" \
" .previous" \
: "+r"(err) \
: "r"(addr), "r"(x), "i"(-EFAULT) \
: "cc")
extern unsigned long __arch_clear_user(void __user * addr, unsigned long n);
extern long strncpy_from_user(char *dest, const char __user * src, long count);
extern __must_check long strlen_user(const char __user * str);
extern __must_check long strnlen_user(const char __user * str, long n);
extern unsigned long __arch_copy_from_user(void *to, const void __user * from,
unsigned long n);
extern unsigned long __arch_copy_to_user(void __user * to, const void *from,
unsigned long n);
#define raw_copy_from_user __arch_copy_from_user
#define raw_copy_to_user __arch_copy_to_user
#define INLINE_COPY_FROM_USER
#define INLINE_COPY_TO_USER
static inline unsigned long clear_user(void __user * to, unsigned long n)
{
if (access_ok(VERIFY_WRITE, to, n))
n = __arch_clear_user(to, n);
return n;
}
static inline unsigned long __clear_user(void __user * to, unsigned long n)
{
return __arch_clear_user(to, n);
}
#endif /* _ASMNDS32_UACCESS_H */
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