android_kernel_xiaomi_sm8350/arch/avr32/include/asm/uaccess.h
Haavard Skinnemoen 61f3632fdc avr32: fix out-of-range rjmp instruction on large kernels
Use .subsection to place fixups closer to their jump targets. This
increases the maximum size of the kernel before we get link errors
significantly.

The problem here is that we don't have a "call"-ish pseudo-instruction
to use instead of rjmp...we could add one, but that means we'll have to
wait for a new toolchain release, wait until we're fairly sure most
people are using it, etc...

As an added bonus, it should decrease the RAM footprint slightly,
though it might pollute the icache a bit more.

Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
2009-01-16 09:38:05 +01:00

325 lines
9.5 KiB
C

/*
* Copyright (C) 2004-2006 Atmel Corporation
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#ifndef __ASM_AVR32_UACCESS_H
#define __ASM_AVR32_UACCESS_H
#include <linux/errno.h>
#include <linux/sched.h>
#define VERIFY_READ 0
#define VERIFY_WRITE 1
typedef struct {
unsigned int is_user_space;
} mm_segment_t;
/*
* 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 (Data Segment Register?), these macros are misnamed.
*/
#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
#define segment_eq(a,b) ((a).is_user_space == (b).is_user_space)
#define USER_ADDR_LIMIT 0x80000000
#define KERNEL_DS MAKE_MM_SEG(0)
#define USER_DS MAKE_MM_SEG(1)
#define get_ds() (KERNEL_DS)
static inline mm_segment_t get_fs(void)
{
return MAKE_MM_SEG(test_thread_flag(TIF_USERSPACE));
}
static inline void set_fs(mm_segment_t s)
{
if (s.is_user_space)
set_thread_flag(TIF_USERSPACE);
else
clear_thread_flag(TIF_USERSPACE);
}
/*
* Test whether a block of memory is a valid user space address.
* Returns 0 if the range is valid, nonzero otherwise.
*
* We do the following checks:
* 1. Is the access from kernel space?
* 2. Does (addr + size) set the carry bit?
* 3. Is (addr + size) a negative number (i.e. >= 0x80000000)?
*
* If yes on the first check, access is granted.
* If no on any of the others, access is denied.
*/
#define __range_ok(addr, size) \
(test_thread_flag(TIF_USERSPACE) \
&& (((unsigned long)(addr) >= 0x80000000) \
|| ((unsigned long)(size) > 0x80000000) \
|| (((unsigned long)(addr) + (unsigned long)(size)) > 0x80000000)))
#define access_ok(type, addr, size) (likely(__range_ok(addr, size) == 0))
/* Generic arbitrary sized copy. Return the number of bytes NOT copied */
extern __kernel_size_t __copy_user(void *to, const void *from,
__kernel_size_t n);
extern __kernel_size_t copy_to_user(void __user *to, const void *from,
__kernel_size_t n);
extern __kernel_size_t copy_from_user(void *to, const void __user *from,
__kernel_size_t n);
static inline __kernel_size_t __copy_to_user(void __user *to, const void *from,
__kernel_size_t n)
{
return __copy_user((void __force *)to, from, n);
}
static inline __kernel_size_t __copy_from_user(void *to,
const void __user *from,
__kernel_size_t n)
{
return __copy_user(to, (const void __force *)from, n);
}
#define __copy_to_user_inatomic __copy_to_user
#define __copy_from_user_inatomic __copy_from_user
/*
* 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((x),(ptr),sizeof(*(ptr)))
/*
* 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, 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((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)))
extern int __get_user_bad(void);
extern int __put_user_bad(void);
#define __get_user_nocheck(x, ptr, size) \
({ \
unsigned long __gu_val = 0; \
int __gu_err = 0; \
\
switch (size) { \
case 1: __get_user_asm("ub", __gu_val, ptr, __gu_err); break; \
case 2: __get_user_asm("uh", __gu_val, ptr, __gu_err); break; \
case 4: __get_user_asm("w", __gu_val, ptr, __gu_err); break; \
default: __gu_err = __get_user_bad(); break; \
} \
\
x = (typeof(*(ptr)))__gu_val; \
__gu_err; \
})
#define __get_user_check(x, ptr, size) \
({ \
unsigned long __gu_val = 0; \
const typeof(*(ptr)) __user * __gu_addr = (ptr); \
int __gu_err = 0; \
\
if (access_ok(VERIFY_READ, __gu_addr, size)) { \
switch (size) { \
case 1: \
__get_user_asm("ub", __gu_val, __gu_addr, \
__gu_err); \
break; \
case 2: \
__get_user_asm("uh", __gu_val, __gu_addr, \
__gu_err); \
break; \
case 4: \
__get_user_asm("w", __gu_val, __gu_addr, \
__gu_err); \
break; \
default: \
__gu_err = __get_user_bad(); \
break; \
} \
} else { \
__gu_err = -EFAULT; \
} \
x = (typeof(*(ptr)))__gu_val; \
__gu_err; \
})
#define __get_user_asm(suffix, __gu_val, ptr, __gu_err) \
asm volatile( \
"1: ld." suffix " %1, %3 \n" \
"2: \n" \
" .subsection 1 \n" \
"3: mov %0, %4 \n" \
" rjmp 2b \n" \
" .subsection 0 \n" \
" .section __ex_table, \"a\" \n" \
" .long 1b, 3b \n" \
" .previous \n" \
: "=r"(__gu_err), "=r"(__gu_val) \
: "0"(__gu_err), "m"(*(ptr)), "i"(-EFAULT))
#define __put_user_nocheck(x, ptr, size) \
({ \
typeof(*(ptr)) __pu_val; \
int __pu_err = 0; \
\
__pu_val = (x); \
switch (size) { \
case 1: __put_user_asm("b", ptr, __pu_val, __pu_err); break; \
case 2: __put_user_asm("h", ptr, __pu_val, __pu_err); break; \
case 4: __put_user_asm("w", ptr, __pu_val, __pu_err); break; \
case 8: __put_user_asm("d", ptr, __pu_val, __pu_err); break; \
default: __pu_err = __put_user_bad(); break; \
} \
__pu_err; \
})
#define __put_user_check(x, ptr, size) \
({ \
typeof(*(ptr)) __pu_val; \
typeof(*(ptr)) __user *__pu_addr = (ptr); \
int __pu_err = 0; \
\
__pu_val = (x); \
if (access_ok(VERIFY_WRITE, __pu_addr, size)) { \
switch (size) { \
case 1: \
__put_user_asm("b", __pu_addr, __pu_val, \
__pu_err); \
break; \
case 2: \
__put_user_asm("h", __pu_addr, __pu_val, \
__pu_err); \
break; \
case 4: \
__put_user_asm("w", __pu_addr, __pu_val, \
__pu_err); \
break; \
case 8: \
__put_user_asm("d", __pu_addr, __pu_val, \
__pu_err); \
break; \
default: \
__pu_err = __put_user_bad(); \
break; \
} \
} else { \
__pu_err = -EFAULT; \
} \
__pu_err; \
})
#define __put_user_asm(suffix, ptr, __pu_val, __gu_err) \
asm volatile( \
"1: st." suffix " %1, %3 \n" \
"2: \n" \
" .subsection 1 \n" \
"3: mov %0, %4 \n" \
" rjmp 2b \n" \
" .subsection 0 \n" \
" .section __ex_table, \"a\" \n" \
" .long 1b, 3b \n" \
" .previous \n" \
: "=r"(__gu_err), "=m"(*(ptr)) \
: "0"(__gu_err), "r"(__pu_val), "i"(-EFAULT))
extern __kernel_size_t clear_user(void __user *addr, __kernel_size_t size);
extern __kernel_size_t __clear_user(void __user *addr, __kernel_size_t size);
extern long strncpy_from_user(char *dst, const char __user *src, long count);
extern long __strncpy_from_user(char *dst, const char __user *src, long count);
extern long strnlen_user(const char __user *__s, long __n);
extern long __strnlen_user(const char __user *__s, long __n);
#define strlen_user(s) strnlen_user(s, ~0UL >> 1)
struct exception_table_entry
{
unsigned long insn, fixup;
};
#endif /* __ASM_AVR32_UACCESS_H */