/* * 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" \ " .section .fixup, \"ax\" \n" \ "3: mov %0, %4 \n" \ " rjmp 2b \n" \ " .previous \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" \ " .section .fixup, \"ax\" \n" \ "3: mov %0, %4 \n" \ " rjmp 2b \n" \ " .previous \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 */