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DEFINITIONS
This source file includes following definitions.
- get_fs
- set_fs
- access_ok
- __generic_copy_from_user_nocheck
- __generic_copy_to_user_nocheck
#ifndef _ASM_M32R_UACCESS_H
#define _ASM_M32R_UACCESS_H
/*
* linux/include/asm-m32r/uaccess.h
*
* M32R version.
* Copyright (C) 2004, 2006 Hirokazu Takata <takata at linux-m32r.org>
*/
/*
* User space memory access functions
*/
#include <linux/errno.h>
#include <linux/thread_info.h>
#include <asm/page.h>
#include <asm/setup.h>
#define VERIFY_READ 0
#define VERIFY_WRITE 1
/*
* 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.
*/
#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
#ifdef CONFIG_MMU
#define KERNEL_DS MAKE_MM_SEG(0xFFFFFFFF)
#define USER_DS MAKE_MM_SEG(PAGE_OFFSET)
#define get_ds() (KERNEL_DS)
#define get_fs() (current_thread_info()->addr_limit)
#define set_fs(x) (current_thread_info()->addr_limit = (x))
#else /* not CONFIG_MMU */
#define KERNEL_DS MAKE_MM_SEG(0xFFFFFFFF)
#define USER_DS MAKE_MM_SEG(0xFFFFFFFF)
#define get_ds() (KERNEL_DS)
static inline mm_segment_t get_fs(void)
{
return USER_DS;
}
static inline void set_fs(mm_segment_t s)
{
}
#endif /* not CONFIG_MMU */
#define segment_eq(a,b) ((a).seg == (b).seg)
#define __addr_ok(addr) \
((unsigned long)(addr) < (current_thread_info()->addr_limit.seg))
/*
* Test whether a block of memory is a valid user space address.
* Returns 0 if the range is valid, nonzero otherwise.
*
* This is equivalent to the following test:
* (u33)addr + (u33)size >= (u33)current->addr_limit.seg
*
* This needs 33-bit arithmetic. We have a carry...
*/
#define __range_ok(addr,size) ({ \
unsigned long flag, roksum; \
__chk_user_ptr(addr); \
asm ( \
" cmpu %1, %1 ; clear cbit\n" \
" addx %1, %3 ; set cbit if overflow\n" \
" subx %0, %0\n" \
" cmpu %4, %1\n" \
" subx %0, %5\n" \
: "=&r" (flag), "=r" (roksum) \
: "1" (addr), "r" ((int)(size)), \
"r" (current_thread_info()->addr_limit.seg), "r" (0) \
: "cbit" ); \
flag; })
/**
* access_ok: - Checks if a user space pointer is valid
* @type: Type of access: %VERIFY_READ or %VERIFY_WRITE. Note that
* %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe
* to write to a block, it is always safe to read from it.
* @addr: User space pointer to start of block to check
* @size: Size of block to check
*
* Context: User context only. This function may sleep.
*
* 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.
*/
#ifdef CONFIG_MMU
#define access_ok(type,addr,size) (likely(__range_ok(addr,size) == 0))
#else
static inline int access_ok(int type, const void *addr, unsigned long size)
{
unsigned long val = (unsigned long)addr;
return ((val >= memory_start) && ((val + size) < memory_end));
}
#endif /* CONFIG_MMU */
/*
* 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);
/*
* 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).
*/
/* Careful: we have to cast the result to the type of the pointer for sign
reasons */
/**
* 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.
*
* 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) \
__get_user_check((x),(ptr),sizeof(*(ptr)))
/**
* 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.
*
* 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) \
__put_user_check((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
/**
* __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.
*
* 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) \
__get_user_nocheck((x),(ptr),sizeof(*(ptr)))
#define __get_user_nocheck(x,ptr,size) \
({ \
long __gu_err = 0; \
unsigned long __gu_val; \
might_sleep(); \
__get_user_size(__gu_val,(ptr),(size),__gu_err); \
(x) = (__typeof__(*(ptr)))__gu_val; \
__gu_err; \
})
#define __get_user_check(x,ptr,size) \
({ \
long __gu_err = -EFAULT; \
unsigned long __gu_val = 0; \
const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \
might_sleep(); \
if (access_ok(VERIFY_READ,__gu_addr,size)) \
__get_user_size(__gu_val,__gu_addr,(size),__gu_err); \
(x) = (__typeof__(*(ptr)))__gu_val; \
__gu_err; \
})
extern long __get_user_bad(void);
#define __get_user_size(x,ptr,size,retval) \
do { \
retval = 0; \
__chk_user_ptr(ptr); \
switch (size) { \
case 1: __get_user_asm(x,ptr,retval,"ub"); break; \
case 2: __get_user_asm(x,ptr,retval,"uh"); break; \
case 4: __get_user_asm(x,ptr,retval,""); break; \
default: (x) = __get_user_bad(); \
} \
} while (0)
#define __get_user_asm(x, addr, err, itype) \
__asm__ __volatile__( \
" .fillinsn\n" \
"1: ld"itype" %1,@%2\n" \
" .fillinsn\n" \
"2:\n" \
".section .fixup,\"ax\"\n" \
" .balign 4\n" \
"3: ldi %0,%3\n" \
" seth r14,#high(2b)\n" \
" or3 r14,r14,#low(2b)\n" \
" jmp r14\n" \
".previous\n" \
".section __ex_table,\"a\"\n" \
" .balign 4\n" \
" .long 1b,3b\n" \
".previous" \
: "=&r" (err), "=&r" (x) \
: "r" (addr), "i" (-EFAULT), "0" (err) \
: "r14", "memory")
/**
* __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.
*
* 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) \
__put_user_nocheck((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
#define __put_user_nocheck(x,ptr,size) \
({ \
long __pu_err; \
might_sleep(); \
__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); \
might_sleep(); \
if (access_ok(VERIFY_WRITE,__pu_addr,size)) \
__put_user_size((x),__pu_addr,(size),__pu_err); \
__pu_err; \
})
#if defined(__LITTLE_ENDIAN__)
#define __put_user_u64(x, addr, err) \
__asm__ __volatile__( \
" .fillinsn\n" \
"1: st %L1,@%2\n" \
" .fillinsn\n" \
"2: st %H1,@(4,%2)\n" \
" .fillinsn\n" \
"3:\n" \
".section .fixup,\"ax\"\n" \
" .balign 4\n" \
"4: ldi %0,%3\n" \
" seth r14,#high(3b)\n" \
" or3 r14,r14,#low(3b)\n" \
" jmp r14\n" \
".previous\n" \
".section __ex_table,\"a\"\n" \
" .balign 4\n" \
" .long 1b,4b\n" \
" .long 2b,4b\n" \
".previous" \
: "=&r" (err) \
: "r" (x), "r" (addr), "i" (-EFAULT), "0" (err) \
: "r14", "memory")
#elif defined(__BIG_ENDIAN__)
#define __put_user_u64(x, addr, err) \
__asm__ __volatile__( \
" .fillinsn\n" \
"1: st %H1,@%2\n" \
" .fillinsn\n" \
"2: st %L1,@(4,%2)\n" \
" .fillinsn\n" \
"3:\n" \
".section .fixup,\"ax\"\n" \
" .balign 4\n" \
"4: ldi %0,%3\n" \
" seth r14,#high(3b)\n" \
" or3 r14,r14,#low(3b)\n" \
" jmp r14\n" \
".previous\n" \
".section __ex_table,\"a\"\n" \
" .balign 4\n" \
" .long 1b,4b\n" \
" .long 2b,4b\n" \
".previous" \
: "=&r" (err) \
: "r" (x), "r" (addr), "i" (-EFAULT), "0" (err) \
: "r14", "memory")
#else
#error no endian defined
#endif
extern void __put_user_bad(void);
#define __put_user_size(x,ptr,size,retval) \
do { \
retval = 0; \
__chk_user_ptr(ptr); \
switch (size) { \
case 1: __put_user_asm(x,ptr,retval,"b"); break; \
case 2: __put_user_asm(x,ptr,retval,"h"); break; \
case 4: __put_user_asm(x,ptr,retval,""); break; \
case 8: __put_user_u64((__typeof__(*ptr))(x),ptr,retval); break;\
default: __put_user_bad(); \
} \
} while (0)
struct __large_struct { unsigned long buf[100]; };
#define __m(x) (*(struct __large_struct *)(x))
/*
* Tell gcc we read from memory instead of writing: this is because
* we do not write to any memory gcc knows about, so there are no
* aliasing issues.
*/
#define __put_user_asm(x, addr, err, itype) \
__asm__ __volatile__( \
" .fillinsn\n" \
"1: st"itype" %1,@%2\n" \
" .fillinsn\n" \
"2:\n" \
".section .fixup,\"ax\"\n" \
" .balign 4\n" \
"3: ldi %0,%3\n" \
" seth r14,#high(2b)\n" \
" or3 r14,r14,#low(2b)\n" \
" jmp r14\n" \
".previous\n" \
".section __ex_table,\"a\"\n" \
" .balign 4\n" \
" .long 1b,3b\n" \
".previous" \
: "=&r" (err) \
: "r" (x), "r" (addr), "i" (-EFAULT), "0" (err) \
: "r14", "memory")
/*
* Here we special-case 1, 2 and 4-byte copy_*_user invocations. On a fault
* we return the initial request size (1, 2 or 4), as copy_*_user should do.
* If a store crosses a page boundary and gets a fault, the m32r will not write
* anything, so this is accurate.
*/
/*
* Copy To/From Userspace
*/
/* Generic arbitrary sized copy. */
/* Return the number of bytes NOT copied. */
#define __copy_user(to,from,size) \
do { \
unsigned long __dst, __src, __c; \
__asm__ __volatile__ ( \
" mv r14, %0\n" \
" or r14, %1\n" \
" beq %0, %1, 9f\n" \
" beqz %2, 9f\n" \
" and3 r14, r14, #3\n" \
" bnez r14, 2f\n" \
" and3 %2, %2, #3\n" \
" beqz %3, 2f\n" \
" addi %0, #-4 ; word_copy \n" \
" .fillinsn\n" \
"0: ld r14, @%1+\n" \
" addi %3, #-1\n" \
" .fillinsn\n" \
"1: st r14, @+%0\n" \
" bnez %3, 0b\n" \
" beqz %2, 9f\n" \
" addi %0, #4\n" \
" .fillinsn\n" \
"2: ldb r14, @%1 ; byte_copy \n" \
" .fillinsn\n" \
"3: stb r14, @%0\n" \
" addi %1, #1\n" \
" addi %2, #-1\n" \
" addi %0, #1\n" \
" bnez %2, 2b\n" \
" .fillinsn\n" \
"9:\n" \
".section .fixup,\"ax\"\n" \
" .balign 4\n" \
"5: addi %3, #1\n" \
" addi %1, #-4\n" \
" .fillinsn\n" \
"6: slli %3, #2\n" \
" add %2, %3\n" \
" addi %0, #4\n" \
" .fillinsn\n" \
"7: seth r14, #high(9b)\n" \
" or3 r14, r14, #low(9b)\n" \
" jmp r14\n" \
".previous\n" \
".section __ex_table,\"a\"\n" \
" .balign 4\n" \
" .long 0b,6b\n" \
" .long 1b,5b\n" \
" .long 2b,9b\n" \
" .long 3b,9b\n" \
".previous\n" \
: "=&r" (__dst), "=&r" (__src), "=&r" (size), \
"=&r" (__c) \
: "0" (to), "1" (from), "2" (size), "3" (size / 4) \
: "r14", "memory"); \
} while (0)
#define __copy_user_zeroing(to,from,size) \
do { \
unsigned long __dst, __src, __c; \
__asm__ __volatile__ ( \
" mv r14, %0\n" \
" or r14, %1\n" \
" beq %0, %1, 9f\n" \
" beqz %2, 9f\n" \
" and3 r14, r14, #3\n" \
" bnez r14, 2f\n" \
" and3 %2, %2, #3\n" \
" beqz %3, 2f\n" \
" addi %0, #-4 ; word_copy \n" \
" .fillinsn\n" \
"0: ld r14, @%1+\n" \
" addi %3, #-1\n" \
" .fillinsn\n" \
"1: st r14, @+%0\n" \
" bnez %3, 0b\n" \
" beqz %2, 9f\n" \
" addi %0, #4\n" \
" .fillinsn\n" \
"2: ldb r14, @%1 ; byte_copy \n" \
" .fillinsn\n" \
"3: stb r14, @%0\n" \
" addi %1, #1\n" \
" addi %2, #-1\n" \
" addi %0, #1\n" \
" bnez %2, 2b\n" \
" .fillinsn\n" \
"9:\n" \
".section .fixup,\"ax\"\n" \
" .balign 4\n" \
"5: addi %3, #1\n" \
" addi %1, #-4\n" \
" .fillinsn\n" \
"6: slli %3, #2\n" \
" add %2, %3\n" \
" addi %0, #4\n" \
" .fillinsn\n" \
"7: ldi r14, #0 ; store zero \n" \
" .fillinsn\n" \
"8: addi %2, #-1\n" \
" stb r14, @%0 ; ACE? \n" \
" addi %0, #1\n" \
" bnez %2, 8b\n" \
" seth r14, #high(9b)\n" \
" or3 r14, r14, #low(9b)\n" \
" jmp r14\n" \
".previous\n" \
".section __ex_table,\"a\"\n" \
" .balign 4\n" \
" .long 0b,6b\n" \
" .long 1b,5b\n" \
" .long 2b,7b\n" \
" .long 3b,7b\n" \
".previous\n" \
: "=&r" (__dst), "=&r" (__src), "=&r" (size), \
"=&r" (__c) \
: "0" (to), "1" (from), "2" (size), "3" (size / 4) \
: "r14", "memory"); \
} while (0)
/* We let the __ versions of copy_from/to_user inline, because they're often
* used in fast paths and have only a small space overhead.
*/
static inline unsigned long __generic_copy_from_user_nocheck(void *to,
const void __user *from, unsigned long n)
{
__copy_user_zeroing(to,from,n);
return n;
}
static inline unsigned long __generic_copy_to_user_nocheck(void __user *to,
const void *from, unsigned long n)
{
__copy_user(to,from,n);
return n;
}
unsigned long __generic_copy_to_user(void __user *, const void *, unsigned long);
unsigned long __generic_copy_from_user(void *, const void __user *, unsigned long);
/**
* __copy_to_user: - Copy a block of data into user space, with less checking.
* @to: Destination address, in user space.
* @from: Source address, in kernel space.
* @n: Number of bytes to copy.
*
* Context: User context only. This function may sleep.
*
* Copy data from kernel space to user space. Caller must check
* the specified block with access_ok() before calling this function.
*
* Returns number of bytes that could not be copied.
* On success, this will be zero.
*/
#define __copy_to_user(to,from,n) \
__generic_copy_to_user_nocheck((to),(from),(n))
#define __copy_to_user_inatomic __copy_to_user
#define __copy_from_user_inatomic __copy_from_user
/**
* copy_to_user: - Copy a block of data into user space.
* @to: Destination address, in user space.
* @from: Source address, in kernel space.
* @n: Number of bytes to copy.
*
* Context: User context only. This function may sleep.
*
* Copy data from kernel space to user space.
*
* Returns number of bytes that could not be copied.
* On success, this will be zero.
*/
#define copy_to_user(to,from,n) \
({ \
might_sleep(); \
__generic_copy_to_user((to),(from),(n)); \
})
/**
* __copy_from_user: - Copy a block of data from user space, with less checking. * @to: Destination address, in kernel space.
* @from: Source address, in user space.
* @n: Number of bytes to copy.
*
* Context: User context only. This function may sleep.
*
* Copy data from user space to kernel space. Caller must check
* the specified block with access_ok() before calling this function.
*
* Returns number of bytes that could not be copied.
* On success, this will be zero.
*
* If some data could not be copied, this function will pad the copied
* data to the requested size using zero bytes.
*/
#define __copy_from_user(to,from,n) \
__generic_copy_from_user_nocheck((to),(from),(n))
/**
* copy_from_user: - Copy a block of data from user space.
* @to: Destination address, in kernel space.
* @from: Source address, in user space.
* @n: Number of bytes to copy.
*
* Context: User context only. This function may sleep.
*
* Copy data from user space to kernel space.
*
* Returns number of bytes that could not be copied.
* On success, this will be zero.
*
* If some data could not be copied, this function will pad the copied
* data to the requested size using zero bytes.
*/
#define copy_from_user(to,from,n) \
({ \
might_sleep(); \
__generic_copy_from_user((to),(from),(n)); \
})
long __must_check strncpy_from_user(char *dst, const char __user *src,
long count);
long __must_check __strncpy_from_user(char *dst,
const char __user *src, long count);
/**
* __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.
*/
unsigned long __clear_user(void __user *mem, unsigned long len);
/**
* clear_user: - Zero a block of memory in user space.
* @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.
*/
unsigned long clear_user(void __user *mem, unsigned long len);
/**
* strlen_user: - Get the size of a string in user space.
* @str: The string to measure.
*
* Context: User context only. This function may sleep.
*
* 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 there is a limit on the length of a valid string, you may wish to
* consider using strnlen_user() instead.
*/
#define strlen_user(str) strnlen_user(str, ~0UL >> 1)
long strnlen_user(const char __user *str, long n);
#endif /* _ASM_M32R_UACCESS_H */