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Diffstat (limited to 'target/linux/ubicom32/files/arch/ubicom32/include/asm/uaccess.h')
| -rw-r--r-- | target/linux/ubicom32/files/arch/ubicom32/include/asm/uaccess.h | 347 |
1 files changed, 347 insertions, 0 deletions
diff --git a/target/linux/ubicom32/files/arch/ubicom32/include/asm/uaccess.h b/target/linux/ubicom32/files/arch/ubicom32/include/asm/uaccess.h new file mode 100644 index 000000000..eef739d12 --- /dev/null +++ b/target/linux/ubicom32/files/arch/ubicom32/include/asm/uaccess.h @@ -0,0 +1,347 @@ +/* + * arch/ubicom32/include/asm/uaccess.h + * User space memory access functions for Ubicom32 architecture. + * + * (C) Copyright 2009, Ubicom, Inc. + * + * This file is part of the Ubicom32 Linux Kernel Port. + * + * The Ubicom32 Linux Kernel Port 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. + * + * The Ubicom32 Linux Kernel Port is distributed in the hope that it + * will be useful, but WITHOUT ANY WARRANTY; without even the implied + * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See + * the GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with the Ubicom32 Linux Kernel Port. If not, + * see <http://www.gnu.org/licenses/>. + * + * Ubicom32 implementation derived from (with many thanks): + * arch/m68knommu + * arch/blackfin + * arch/parisc + * arch/alpha + */ +#ifndef _ASM_UBICOM32_UACCESS_H +#define _ASM_UBICOM32_UACCESS_H + +/* + * User space memory access functions + */ +#include <linux/sched.h> +#include <linux/mm.h> +#include <linux/string.h> + +#include <asm/segment.h> + +#define VERIFY_READ 0 +#define VERIFY_WRITE 1 + +/* + * 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; +}; + +/* + * Ubicom32 does not currently support the exception table handling. + */ +extern unsigned long search_exception_table(unsigned long); + + +#if defined(CONFIG_ACCESS_OK_CHECKS_ENABLED) +extern int __access_ok(unsigned long addr, unsigned long size); +#else +static inline int __access_ok(unsigned long addr, unsigned long size) +{ + return 1; +} +#endif +#define access_ok(type, addr, size) \ + likely(__access_ok((unsigned long)(addr), (size))) + +/* + * The following functions do not exist. They keep callers + * of put_user and get_user from passing unsupported argument + * types. They result in a link time error. + */ +extern int __put_user_bad(void); +extern int __get_user_bad(void); + +/* + * __put_user_no_check() + * Put the requested data into the user space verifying the address + * + * Careful to not + * (a) re-use the arguments for side effects (sizeof/typeof is ok) + * (b) require any knowledge of processes at this stage + */ +#define __put_user_no_check(x, ptr, size) \ +({ \ + int __pu_err = 0; \ + __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ + switch (size) { \ + case 1: \ + case 2: \ + case 4: \ + case 8: \ + *__pu_addr = (__typeof__(*(ptr)))x; \ + break; \ + default: \ + __pu_err = __put_user_bad(); \ + break; \ + } \ + __pu_err; \ +}) + +/* + * __put_user_check() + * Put the requested data into the user space verifying the address + * + * Careful to not + * (a) re-use the arguments for side effects (sizeof/typeof is ok) + * (b) require any knowledge of processes at this stage + * + * If requested, access_ok() will verify that ptr is a valid user + * pointer. + */ +#define __put_user_check(x, ptr, size) \ +({ \ + int __pu_err = -EFAULT; \ + __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ + if (access_ok(VERIFY_WRITE, __pu_addr, size)) { \ + __pu_err = 0; \ + switch (size) { \ + case 1: \ + case 2: \ + case 4: \ + case 8: \ + *__pu_addr = (__typeof__(*(ptr)))x; \ + break; \ + default: \ + __pu_err = __put_user_bad(); \ + break; \ + } \ + } \ + __pu_err; \ +}) + +/* + * __get_user_no_check() + * Read the value at ptr into x. + * + * If requested, access_ok() will verify that ptr is a valid user + * pointer. If the caller passes a modifying argument for ptr (e.g. x++) + * this macro will not work. + */ +#define __get_user_no_check(x, ptr, size) \ +({ \ + int __gu_err = 0; \ + __typeof__((x)) __gu_val = 0; \ + const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ + switch (size) { \ + case 1: \ + case 2: \ + case 4: \ + case 8: \ + __gu_val = (__typeof__((x)))*(__gu_addr); \ + break; \ + default: \ + __gu_err = __get_user_bad(); \ + (x) = 0; \ + break; \ + } \ + (x) = __gu_val; \ + __gu_err; \ +}) + +/* + * __get_user_check() + * Read the value at ptr into x. + * + * If requested, access_ok() will verify that ptr is a valid user + * pointer. + */ +#define __get_user_check(x, ptr, size) \ +({ \ + int __gu_err = -EFAULT; \ + __typeof__(x) __gu_val = 0; \ + const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ + if (access_ok(VERIFY_READ, __gu_addr, size)) { \ + __gu_err = 0; \ + switch (size) { \ + case 1: \ + case 2: \ + case 4: \ + case 8: \ + __gu_val = (__typeof__((x)))*(__gu_addr); \ + break; \ + default: \ + __gu_err = __get_user_bad(); \ + (x) = 0; \ + break; \ + } \ + } \ + (x) = __gu_val; \ + __gu_err; \ +}) + +/* + * The "xxx" versions are allowed to perform some amount of address + * space checking. See access_ok(). + */ +#define put_user(x,ptr) \ + __put_user_check((__typeof__(*(ptr)))(x),(ptr), sizeof(*(ptr))) +#define get_user(x,ptr) \ + __get_user_check((x), (ptr), sizeof(*(ptr))) + +/* + * The "__xxx" versions do not do address space checking, useful when + * doing multiple accesses to the same area (the programmer has to do the + * checks by hand with "access_ok()") + */ +#define __put_user(x,ptr) \ + __put_user_no_check((__typeof__(*(ptr)))(x),(ptr), sizeof(*(ptr))) +#define __get_user(x,ptr) \ + __get_user_no_check((x), (ptr), sizeof(*(ptr))) + +/* + * __copy_tofrom_user_no_check() + * Copy the data either to or from user space. + * + * Return the number of bytes NOT copied. + */ +static inline unsigned long +__copy_tofrom_user_no_check(void *to, const void *from, unsigned long n) +{ + memcpy(to, from, n); + return 0; +} + +/* + * copy_to_user() + * Copy the kernel data to user space. + * + * Return the number of bytes that were copied. + */ +static inline unsigned long +copy_to_user(void __user *to, const void *from, unsigned long n) +{ + if (!access_ok(VERIFY_WRITE, to, n)) { + return n; + } + return __copy_tofrom_user_no_check((__force void *)to, from, n); +} + +/* + * copy_from_user() + * Copy the user data to kernel space. + * + * Return the number of bytes that were copied. On error, we zero + * out the destination. + */ +static inline unsigned long +copy_from_user(void *to, const void __user *from, unsigned long n) +{ + if (!access_ok(VERIFY_READ, from, n)) { + return n; + } + return __copy_tofrom_user_no_check(to, (__force void *)from, n); +} + +#define __copy_to_user(to, from, n) \ + __copy_tofrom_user_no_check((__force void *)to, from, n) +#define __copy_from_user(to, from, n) \ + __copy_tofrom_user_no_check(to, (__force void *)from, n) +#define __copy_to_user_inatomic(to, from, n) \ + __copy_tofrom_user_no_check((__force void *)to, from, n) +#define __copy_from_user_inatomic(to, from, n) \ + __copy_tofrom_user_no_check(to, (__force void *)from, n) + +#define copy_to_user_ret(to, from, n, retval) \ + ({ if (copy_to_user(to, from, n)) return retval; }) + +#define copy_from_user_ret(to, from, n, retval) \ + ({ if (copy_from_user(to, from, n)) return retval; }) + +/* + * strncpy_from_user() + * Copy a null terminated string from userspace. + * + * dst - Destination in kernel space. The buffer must be at least count. + * src - Address of string in user space. + * count - Maximum number of bytes to copy (including the trailing NULL). + * + * Returns the length of the string (not including the trailing NULL. If + * count is smaller than the length of the string, we copy count bytes + * and return count. + * + */ +static inline long strncpy_from_user(char *dst, const __user char *src, long count) +{ + char *tmp; + if (!access_ok(VERIFY_READ, src, 1)) { + return -EFAULT; + } + + strncpy(dst, src, count); + for (tmp = dst; *tmp && count > 0; tmp++, count--) { + ; + } + return(tmp - dst); +} + +/* + * strnlen_user() + * Return the size of a string (including the ending 0) + * + * Return -EFAULT on exception, a value greater than <n> if too long + */ +static inline long strnlen_user(const __user char *src, long n) +{ + if (!access_ok(VERIFY_READ, src, 1)) { + return -EFAULT; + } + return(strlen(src) + 1); +} + +#define strlen_user(str) strnlen_user(str, 32767) + +/* + * __clear_user() + * Zero Userspace + */ +static inline unsigned long __clear_user(__user void *to, unsigned long n) +{ + memset(to, 0, n); + return 0; +} + +/* + * clear_user() + * Zero user space (check for valid addresses) + */ +static inline unsigned long clear_user(__user void *to, unsigned long n) +{ + if (!access_ok(VERIFY_WRITE, to, n)) { + return -EFAULT; + } + return __clear_user(to, n); +} + +#endif /* _ASM_UBICOM32_UACCESS_H */ |