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Diffstat (limited to 'arch/openrisc/include/asm/uaccess.h')
| -rw-r--r-- | arch/openrisc/include/asm/uaccess.h | 355 |
1 files changed, 355 insertions, 0 deletions
diff --git a/arch/openrisc/include/asm/uaccess.h b/arch/openrisc/include/asm/uaccess.h new file mode 100644 index 0000000..c310e45 --- /dev/null +++ b/arch/openrisc/include/asm/uaccess.h @@ -0,0 +1,355 @@ +/* + * OpenRISC Linux + * + * Linux architectural port borrowing liberally from similar works of + * others. All original copyrights apply as per the original source + * declaration. + * + * OpenRISC implementation: + * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com> + * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se> + * et al. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ + +#ifndef __ASM_OPENRISC_UACCESS_H +#define __ASM_OPENRISC_UACCESS_H + +/* + * User space memory access functions + */ +#include <linux/errno.h> +#include <linux/thread_info.h> +#include <linux/prefetch.h> +#include <linux/string.h> +#include <linux/thread_info.h> +#include <asm/page.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. + */ + +/* addr_limit is the maximum accessible address for the task. we misuse + * the KERNEL_DS and USER_DS values to both assign and compare the + * addr_limit values through the equally misnamed get/set_fs macros. + * (see above) + */ + +#define KERNEL_DS (~0UL) +#define get_ds() (KERNEL_DS) + +#define USER_DS (TASK_SIZE) +#define get_fs() (current_thread_info()->addr_limit) +#define set_fs(x) (current_thread_info()->addr_limit = (x)) + +#define segment_eq(a, b) ((a) == (b)) + +/* Ensure that the range from addr to addr+size is all within the process' + * address space + */ +#define __range_ok(addr, size) (size <= get_fs() && addr <= (get_fs()-size)) + +/* Ensure that addr is below task's addr_limit */ +#define __addr_ok(addr) ((unsigned long) addr < get_fs()) + +#define access_ok(type, addr, size) \ + __range_ok((unsigned long)addr, (unsigned long)size) + +/* + * 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; +}; + +/* Returns 0 if exception not found and fixup otherwise. */ +extern unsigned long search_exception_table(unsigned long); +extern void sort_exception_table(void); + +/* + * 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). + * + * As we use the same address space for kernel and user data on the + * PowerPC, we can just do these as direct assignments. (Of course, the + * exception handling means that it's no longer "just"...) + */ +#define get_user(x, ptr) \ + __get_user_check((x), (ptr), sizeof(*(ptr))) +#define put_user(x, ptr) \ + __put_user_check((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) + +#define __get_user(x, ptr) \ + __get_user_nocheck((x), (ptr), sizeof(*(ptr))) +#define __put_user(x, ptr) \ + __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) + +extern long __put_user_bad(void); + +#define __put_user_nocheck(x, ptr, size) \ +({ \ + long __pu_err; \ + __put_user_size((x), (ptr), (size), __pu_err); \ + __pu_err; \ +}) + +#define __put_user_check(x, ptr, size) \ +({ \ + long __pu_err = -EFAULT; \ + __typeof__(*(ptr)) *__pu_addr = (ptr); \ + if (access_ok(VERIFY_WRITE, __pu_addr, size)) \ + __put_user_size((x), __pu_addr, (size), __pu_err); \ + __pu_err; \ +}) + +#define __put_user_size(x, ptr, size, retval) \ +do { \ + retval = 0; \ + switch (size) { \ + case 1: __put_user_asm(x, ptr, retval, "l.sb"); break; \ + case 2: __put_user_asm(x, ptr, retval, "l.sh"); break; \ + case 4: __put_user_asm(x, ptr, retval, "l.sw"); break; \ + case 8: __put_user_asm2(x, ptr, retval); break; \ + default: __put_user_bad(); \ + } \ +} while (0) + +struct __large_struct { + unsigned long buf[100]; +}; +#define __m(x) (*(struct __large_struct *)(x)) + +/* + * We don't tell gcc that we are accessing memory, but this is OK + * because we do not write to any memory gcc knows about, so there + * are no aliasing issues. + */ +#define __put_user_asm(x, addr, err, op) \ + __asm__ __volatile__( \ + "1: "op" 0(%2),%1\n" \ + "2:\n" \ + ".section .fixup,\"ax\"\n" \ + "3: l.addi %0,r0,%3\n" \ + " l.j 2b\n" \ + " l.nop\n" \ + ".previous\n" \ + ".section __ex_table,\"a\"\n" \ + " .align 2\n" \ + " .long 1b,3b\n" \ + ".previous" \ + : "=r"(err) \ + : "r"(x), "r"(addr), "i"(-EFAULT), "0"(err)) + +#define __put_user_asm2(x, addr, err) \ + __asm__ __volatile__( \ + "1: l.sw 0(%2),%1\n" \ + "2: l.sw 4(%2),%H1\n" \ + "3:\n" \ + ".section .fixup,\"ax\"\n" \ + "4: l.addi %0,r0,%3\n" \ + " l.j 3b\n" \ + " l.nop\n" \ + ".previous\n" \ + ".section __ex_table,\"a\"\n" \ + " .align 2\n" \ + " .long 1b,4b\n" \ + " .long 2b,4b\n" \ + ".previous" \ + : "=r"(err) \ + : "r"(x), "r"(addr), "i"(-EFAULT), "0"(err)) + +#define __get_user_nocheck(x, ptr, size) \ +({ \ + long __gu_err, __gu_val; \ + __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, __gu_val = 0; \ + const __typeof__(*(ptr)) * __gu_addr = (ptr); \ + 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; \ + switch (size) { \ + case 1: __get_user_asm(x, ptr, retval, "l.lbz"); break; \ + case 2: __get_user_asm(x, ptr, retval, "l.lhz"); break; \ + case 4: __get_user_asm(x, ptr, retval, "l.lwz"); break; \ + case 8: __get_user_asm2(x, ptr, retval); \ + default: (x) = __get_user_bad(); \ + } \ +} while (0) + +#define __get_user_asm(x, addr, err, op) \ + __asm__ __volatile__( \ + "1: "op" %1,0(%2)\n" \ + "2:\n" \ + ".section .fixup,\"ax\"\n" \ + "3: l.addi %0,r0,%3\n" \ + " l.addi %1,r0,0\n" \ + " l.j 2b\n" \ + " l.nop\n" \ + ".previous\n" \ + ".section __ex_table,\"a\"\n" \ + " .align 2\n" \ + " .long 1b,3b\n" \ + ".previous" \ + : "=r"(err), "=r"(x) \ + : "r"(addr), "i"(-EFAULT), "0"(err)) + +#define __get_user_asm2(x, addr, err) \ + __asm__ __volatile__( \ + "1: l.lwz %1,0(%2)\n" \ + "2: l.lwz %H1,4(%2)\n" \ + "3:\n" \ + ".section .fixup,\"ax\"\n" \ + "4: l.addi %0,r0,%3\n" \ + " l.addi %1,r0,0\n" \ + " l.addi %H1,r0,0\n" \ + " l.j 3b\n" \ + " l.nop\n" \ + ".previous\n" \ + ".section __ex_table,\"a\"\n" \ + " .align 2\n" \ + " .long 1b,4b\n" \ + " .long 2b,4b\n" \ + ".previous" \ + : "=r"(err), "=&r"(x) \ + : "r"(addr), "i"(-EFAULT), "0"(err)) + +/* more complex routines */ + +extern unsigned long __must_check +__copy_tofrom_user(void *to, const void *from, unsigned long size); + +#define __copy_from_user(to, from, size) \ + __copy_tofrom_user(to, from, size) +#define __copy_to_user(to, from, size) \ + __copy_tofrom_user(to, from, size) + +#define __copy_to_user_inatomic __copy_to_user +#define __copy_from_user_inatomic __copy_from_user + +static inline unsigned long +copy_from_user(void *to, const void *from, unsigned long n) +{ + unsigned long over; + + if (access_ok(VERIFY_READ, from, n)) + return __copy_tofrom_user(to, from, n); + if ((unsigned long)from < TASK_SIZE) { + over = (unsigned long)from + n - TASK_SIZE; + return __copy_tofrom_user(to, from, n - over) + over; + } + return n; +} + +static inline unsigned long +copy_to_user(void *to, const void *from, unsigned long n) +{ + unsigned long over; + + if (access_ok(VERIFY_WRITE, to, n)) + return __copy_tofrom_user(to, from, n); + if ((unsigned long)to < TASK_SIZE) { + over = (unsigned long)to + n - TASK_SIZE; + return __copy_tofrom_user(to, from, n - over) + over; + } + return n; +} + +extern unsigned long __clear_user(void *addr, unsigned long size); + +static inline __must_check unsigned long +clear_user(void *addr, unsigned long size) +{ + + if (access_ok(VERIFY_WRITE, addr, size)) + return __clear_user(addr, size); + if ((unsigned long)addr < TASK_SIZE) { + unsigned long over = (unsigned long)addr + size - TASK_SIZE; + return __clear_user(addr, size - over) + over; + } + return size; +} + +extern int __strncpy_from_user(char *dst, const char *src, long count); + +static inline long strncpy_from_user(char *dst, const char *src, long count) +{ + if (access_ok(VERIFY_READ, src, 1)) + return __strncpy_from_user(dst, src, count); + return -EFAULT; +} + +/* + * Return the size of a string (including the ending 0) + * + * Return 0 for error + */ + +extern int __strnlen_user(const char *str, long len, unsigned long top); + +/* + * Returns the length of the string at str (including the null byte), + * or 0 if we hit a page we can't access, + * or something > len if we didn't find a null byte. + * + * The `top' parameter to __strnlen_user is to make sure that + * we can never overflow from the user area into kernel space. + */ +static inline long strnlen_user(const char __user *str, long len) +{ + unsigned long top = (unsigned long)get_fs(); + unsigned long res = 0; + + if (__addr_ok(str)) + res = __strnlen_user(str, len, top); + + return res; +} + +#define strlen_user(str) strnlen_user(str, TASK_SIZE-1) + +#endif /* __ASM_OPENRISC_UACCESS_H */ |