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linux/arch/mips/include/asm/uaccess.h

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/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* 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 <asm/asm-eva.h>
#include <asm/extable.h>
#ifdef CONFIG_32BIT
#define __UA_LIMIT 0x80000000UL
#define __UA_ADDR ".word"
#define __UA_LA "la"
#define __UA_ADDU "addu"
#define __UA_t0 "$8"
#define __UA_t1 "$9"
#endif /* CONFIG_32BIT */
#ifdef CONFIG_64BIT
extern u64 __ua_limit;
#define __UA_LIMIT __ua_limit
#define __UA_ADDR ".dword"
#define __UA_LA "dla"
#define __UA_ADDU "daddu"
#define __UA_t0 "$12"
#define __UA_t1 "$13"
#endif /* CONFIG_64BIT */
/*
* Is a address valid? This does a straightforward calculation rather
* than tests.
*
* Address valid if:
* - "addr" doesn't have any high-bits set
* - AND "size" doesn't have any high-bits set
* - AND "addr+size" doesn't have any high-bits set
* - OR we are in kernel mode.
*
* __ua_size() is a trick to avoid runtime checking of positive constant
* sizes; for those we already know at compile time that the size is ok.
*/
#define __ua_size(size) \
((__builtin_constant_p(size) && (signed long) (size) > 0) ? 0 : (size))
/*
* access_ok: - Checks if a user space pointer is valid
* @addr: User space pointer to start of block to check
* @size: Size of block to check
*
* Context: User context only. This function may sleep if pagefaults are
* enabled.
*
* Checks if a pointer to a block of memory in user space is valid.
*
* Returns true (nonzero) if the memory block may be valid, false (zero)
* if it is definitely invalid.
*
* Note that, depending on architecture, this function probably just
* checks that the pointer is in the user space range - after calling
* this function, memory access functions may still return -EFAULT.
*/
static inline int __access_ok(const void __user *p, unsigned long size)
{
unsigned long addr = (unsigned long)p;
unsigned long end = addr + size - !!size;
return (__UA_LIMIT & (addr | end | __ua_size(size))) == 0;
}
#define access_ok(addr, size) \
likely(__access_ok((addr), (size)))
/*
* 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.
* @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, 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) \
({ \
__typeof__(*(ptr)) __user *__pu_ptr = (ptr); \
__typeof__(*(ptr)) __pu_val = (x); \
int __pu_err = 0; \
\
__chk_user_ptr(__pu_ptr); \
switch (sizeof(*__pu_ptr)) { \
case 1: \
__put_data_asm(user_sb, __pu_ptr); \
break; \
case 2: \
__put_data_asm(user_sh, __pu_ptr); \
break; \
case 4: \
__put_data_asm(user_sw, __pu_ptr); \
break; \
case 8: \
__PUT_DW(user_sd, __pu_ptr); \
break; \
default: \
BUILD_BUG(); \
} \
\
__pu_err; \
})
/*
* __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) \
({ \
const __typeof__(*(ptr)) __user *__gu_ptr = (ptr); \
int __gu_err = 0; \
\
__chk_user_ptr(__gu_ptr); \
switch (sizeof(*__gu_ptr)) { \
case 1: \
__get_data_asm((x), user_lb, __gu_ptr); \
break; \
case 2: \
__get_data_asm((x), user_lh, __gu_ptr); \
break; \
case 4: \
__get_data_asm((x), user_lw, __gu_ptr); \
break; \
case 8: \
__GET_DW((x), user_ld, __gu_ptr); \
break; \
default: \
BUILD_BUG(); \
} \
\
__gu_err; \
})
struct __large_struct { unsigned long buf[100]; };
#define __m(x) (*(struct __large_struct __user *)(x))
#ifdef CONFIG_32BIT
#define __GET_DW(val, insn, ptr) __get_data_asm_ll32(val, insn, ptr)
#endif
#ifdef CONFIG_64BIT
#define __GET_DW(val, insn, ptr) __get_data_asm(val, insn, ptr)
#endif
#define __get_data_asm(val, insn, addr) \
{ \
long __gu_tmp; \
\
__asm__ __volatile__( \
"1: "insn("%1", "%3")" \n" \
"2: \n" \
" .insn \n" \
" .section .fixup,\"ax\" \n" \
"3: li %0, %4 \n" \
" move %1, $0 \n" \
" j 2b \n" \
" .previous \n" \
" .section __ex_table,\"a\" \n" \
" "__UA_ADDR "\t1b, 3b \n" \
" .previous \n" \
: "=r" (__gu_err), "=r" (__gu_tmp) \
: "0" (0), "o" (__m(addr)), "i" (-EFAULT)); \
\
(val) = (__typeof__(*(addr))) __gu_tmp; \
}
/*
* Get a long long 64 using 32 bit registers.
*/
#define __get_data_asm_ll32(val, insn, addr) \
{ \
union { \
unsigned long long l; \
__typeof__(*(addr)) t; \
} __gu_tmp; \
\
__asm__ __volatile__( \
"1: " insn("%1", "(%3)")" \n" \
"2: " insn("%D1", "4(%3)")" \n" \
"3: \n" \
" .insn \n" \
" .section .fixup,\"ax\" \n" \
"4: li %0, %4 \n" \
" move %1, $0 \n" \
" move %D1, $0 \n" \
" j 3b \n" \
" .previous \n" \
" .section __ex_table,\"a\" \n" \
" " __UA_ADDR " 1b, 4b \n" \
" " __UA_ADDR " 2b, 4b \n" \
" .previous \n" \
: "=r" (__gu_err), "=&r" (__gu_tmp.l) \
: "0" (0), "r" (addr), "i" (-EFAULT)); \
\
(val) = __gu_tmp.t; \
}
#define HAVE_GET_KERNEL_NOFAULT
#define __get_kernel_nofault(dst, src, type, err_label) \
do { \
int __gu_err; \
\
switch (sizeof(type)) { \
case 1: \
__get_data_asm(*(type *)(dst), kernel_lb, \
(__force type *)(src)); \
break; \
case 2: \
__get_data_asm(*(type *)(dst), kernel_lh, \
(__force type *)(src)); \
break; \
case 4: \
__get_data_asm(*(type *)(dst), kernel_lw, \
(__force type *)(src)); \
break; \
case 8: \
__GET_DW(*(type *)(dst), kernel_ld, \
(__force type *)(src)); \
break; \
default: \
BUILD_BUG(); \
break; \
} \
if (unlikely(__gu_err)) \
goto err_label; \
} while (0)
/*
* Yuck. We need two variants, one for 64bit operation and one
* for 32 bit mode and old iron.
*/
#ifdef CONFIG_32BIT
#define __PUT_DW(insn, ptr) __put_data_asm_ll32(insn, ptr)
#endif
#ifdef CONFIG_64BIT
#define __PUT_DW(insn, ptr) __put_data_asm(insn, ptr)
#endif
#define __put_data_asm(insn, ptr) \
{ \
__asm__ __volatile__( \
"1: "insn("%z2", "%3")" # __put_data_asm \n" \
"2: \n" \
" .insn \n" \
" .section .fixup,\"ax\" \n" \
"3: li %0, %4 \n" \
" j 2b \n" \
" .previous \n" \
" .section __ex_table,\"a\" \n" \
" " __UA_ADDR " 1b, 3b \n" \
" .previous \n" \
: "=r" (__pu_err) \
: "0" (0), "Jr" (__pu_val), "o" (__m(ptr)), \
"i" (-EFAULT)); \
}
#define __put_data_asm_ll32(insn, ptr) \
{ \
__asm__ __volatile__( \
"1: "insn("%2", "(%3)")" # __put_data_asm_ll32 \n" \
"2: "insn("%D2", "4(%3)")" \n" \
"3: \n" \
" .insn \n" \
" .section .fixup,\"ax\" \n" \
"4: li %0, %4 \n" \
" j 3b \n" \
" .previous \n" \
" .section __ex_table,\"a\" \n" \
" " __UA_ADDR " 1b, 4b \n" \
" " __UA_ADDR " 2b, 4b \n" \
" .previous" \
: "=r" (__pu_err) \
: "0" (0), "r" (__pu_val), "r" (ptr), \
"i" (-EFAULT)); \
}
#define __put_kernel_nofault(dst, src, type, err_label) \
do { \
type __pu_val; \
int __pu_err = 0; \
\
__pu_val = *(__force type *)(src); \
switch (sizeof(type)) { \
case 1: \
__put_data_asm(kernel_sb, (type *)(dst)); \
break; \
case 2: \
__put_data_asm(kernel_sh, (type *)(dst)); \
break; \
case 4: \
__put_data_asm(kernel_sw, (type *)(dst)) \
break; \
case 8: \
__PUT_DW(kernel_sd, (type *)(dst)); \
break; \
default: \
BUILD_BUG(); \
break; \
} \
if (unlikely(__pu_err)) \
goto err_label; \
} while (0)
/*
* We're generating jump to subroutines which will be outside the range of
* jump instructions
*/
#ifdef MODULE
#define __MODULE_JAL(destination) \
".set\tnoat\n\t" \
__UA_LA "\t$1, " #destination "\n\t" \
"jalr\t$1\n\t" \
".set\tat\n\t"
#else
#define __MODULE_JAL(destination) \
"jal\t" #destination "\n\t"
#endif
#if defined(CONFIG_CPU_DADDI_WORKAROUNDS) || (defined(CONFIG_EVA) && \
defined(CONFIG_CPU_HAS_PREFETCH))
#define DADDI_SCRATCH "$3"
#else
#define DADDI_SCRATCH "$0"
#endif
extern size_t __raw_copy_from_user(void *__to, const void *__from, size_t __n);
extern size_t __raw_copy_to_user(void *__to, const void *__from, size_t __n);
extern size_t __raw_copy_in_user(void *__to, const void *__from, size_t __n);
static inline unsigned long
raw_copy_from_user(void *to, const void __user *from, unsigned long n)
{
register void *__cu_to_r __asm__("$4");
register const void __user *__cu_from_r __asm__("$5");
register long __cu_len_r __asm__("$6");
__cu_to_r = to;
__cu_from_r = from;
__cu_len_r = n;
__asm__ __volatile__(
".set\tnoreorder\n\t"
__MODULE_JAL(__raw_copy_from_user)
".set\tnoat\n\t"
__UA_ADDU "\t$1, %1, %2\n\t"
".set\tat\n\t"
".set\treorder"
: "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r)
:
: "$8", "$9", "$10", "$11", "$12", "$14", "$15", "$24", "$31",
DADDI_SCRATCH, "memory");
return __cu_len_r;
}
static inline unsigned long
raw_copy_to_user(void __user *to, const void *from, unsigned long n)
{
register void __user *__cu_to_r __asm__("$4");
register const void *__cu_from_r __asm__("$5");
register long __cu_len_r __asm__("$6");
__cu_to_r = (to);
__cu_from_r = (from);
__cu_len_r = (n);
__asm__ __volatile__(
__MODULE_JAL(__raw_copy_to_user)
: "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r)
:
: "$8", "$9", "$10", "$11", "$12", "$14", "$15", "$24", "$31",
DADDI_SCRATCH, "memory");
return __cu_len_r;
}
#define INLINE_COPY_FROM_USER
#define INLINE_COPY_TO_USER
static inline unsigned long
raw_copy_in_user(void __user *to, const void __user *from, unsigned long n)
{
register void __user *__cu_to_r __asm__("$4");
register const void __user *__cu_from_r __asm__("$5");
register long __cu_len_r __asm__("$6");
__cu_to_r = to;
__cu_from_r = from;
__cu_len_r = n;
__asm__ __volatile__(
".set\tnoreorder\n\t"
__MODULE_JAL(__raw_copy_in_user)
".set\tnoat\n\t"
__UA_ADDU "\t$1, %1, %2\n\t"
".set\tat\n\t"
".set\treorder"
: "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r)
:
: "$8", "$9", "$10", "$11", "$12", "$14", "$15", "$24", "$31",
DADDI_SCRATCH, "memory");
return __cu_len_r;
}
extern __kernel_size_t __bzero(void __user *addr, __kernel_size_t size);
/*
* __clear_user: - Zero a block of memory in user space, with less checking.
* @to: Destination address, in user space.
* @n: 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.
*/
static inline __kernel_size_t
__clear_user(void __user *addr, __kernel_size_t size)
{
__kernel_size_t res;
#ifdef CONFIG_CPU_MICROMIPS
/* micromips memset / bzero also clobbers t7 & t8 */
#define bzero_clobbers "$4", "$5", "$6", __UA_t0, __UA_t1, "$15", "$24", "$31"
#else
#define bzero_clobbers "$4", "$5", "$6", __UA_t0, __UA_t1, "$31"
#endif /* CONFIG_CPU_MICROMIPS */
might_fault();
__asm__ __volatile__(
"move\t$4, %1\n\t"
"move\t$5, $0\n\t"
"move\t$6, %2\n\t"
__MODULE_JAL(__bzero)
"move\t%0, $6"
: "=r" (res)
: "r" (addr), "r" (size)
: bzero_clobbers);
return res;
}
#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_asm(char *__to, const char __user *__from, long __len);
/*
* strncpy_from_user: - Copy a NUL terminated string from userspace.
* @dst: Destination address, in kernel space. This buffer must be at
* least @count bytes long.
* @src: Source address, in user space.
* @count: Maximum number of bytes to copy, including the trailing NUL.
*
* Copies a NUL-terminated string from userspace to kernel space.
*
* On success, returns the length of the string (not including the trailing
* NUL).
*
* If access to userspace fails, returns -EFAULT (some data may have been
* copied).
*
* If @count is smaller than the length of the string, copies @count bytes
* and returns @count.
*/
static inline long
strncpy_from_user(char *__to, const char __user *__from, long __len)
{
long res;
if (!access_ok(__from, __len))
return -EFAULT;
might_fault();
__asm__ __volatile__(
"move\t$4, %1\n\t"
"move\t$5, %2\n\t"
"move\t$6, %3\n\t"
__MODULE_JAL(__strncpy_from_user_asm)
"move\t%0, $2"
: "=r" (res)
: "r" (__to), "r" (__from), "r" (__len)
: "$2", "$3", "$4", "$5", "$6", __UA_t0, "$31", "memory");
return res;
}
extern long __strnlen_user_asm(const char __user *s, long n);
/*
* strnlen_user: - Get the size of a string in user space.
* @str: The string to measure.
*
* Context: User context only. This function may sleep if pagefaults are
* enabled.
*
* Get the size of a NUL-terminated string in user space.
*
* Returns the size of the string INCLUDING the terminating NUL.
* On exception, returns 0.
* If the string is too long, returns a value greater than @n.
*/
static inline long strnlen_user(const char __user *s, long n)
{
long res;
if (!access_ok(s, 1))
return 0;
might_fault();
__asm__ __volatile__(
"move\t$4, %1\n\t"
"move\t$5, %2\n\t"
__MODULE_JAL(__strnlen_user_asm)
"move\t%0, $2"
: "=r" (res)
: "r" (s), "r" (n)
: "$2", "$4", "$5", __UA_t0, "$31");
return res;
}
#endif /* _ASM_UACCESS_H */
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