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Diffstat (limited to 'kernel/arch/avr32/include/asm/uaccess.h')
| -rw-r--r-- | kernel/arch/avr32/include/asm/uaccess.h | 328 |
1 files changed, 328 insertions, 0 deletions
diff --git a/kernel/arch/avr32/include/asm/uaccess.h b/kernel/arch/avr32/include/asm/uaccess.h new file mode 100644 index 000000000..68cf638fa --- /dev/null +++ b/kernel/arch/avr32/include/asm/uaccess.h @@ -0,0 +1,328 @@ +/* + * 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 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) \ + __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 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) \ + __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 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) \ + __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 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) \ + __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 = (__force 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 = (__force 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 */ |