1/* 2 * Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu> 3 * Copyright (C) 2008-2009 PetaLogix 4 * Copyright (C) 2006 Atmark Techno, Inc. 5 * 6 * This file is subject to the terms and conditions of the GNU General Public 7 * License. See the file "COPYING" in the main directory of this archive 8 * for more details. 9 */ 10 11#ifndef _ASM_MICROBLAZE_UACCESS_H 12#define _ASM_MICROBLAZE_UACCESS_H 13 14#ifdef __KERNEL__ 15#ifndef __ASSEMBLY__ 16 17#include <linux/kernel.h> 18#include <linux/errno.h> 19#include <linux/sched.h> /* RLIMIT_FSIZE */ 20#include <linux/mm.h> 21 22#include <asm/mmu.h> 23#include <asm/page.h> 24#include <asm/pgtable.h> 25#include <linux/string.h> 26 27#define VERIFY_READ 0 28#define VERIFY_WRITE 1 29 30/* 31 * On Microblaze the fs value is actually the top of the corresponding 32 * address space. 33 * 34 * The fs value determines whether argument validity checking should be 35 * performed or not. If get_fs() == USER_DS, checking is performed, with 36 * get_fs() == KERNEL_DS, checking is bypassed. 37 * 38 * For historical reasons, these macros are grossly misnamed. 39 * 40 * For non-MMU arch like Microblaze, KERNEL_DS and USER_DS is equal. 41 */ 42# define MAKE_MM_SEG(s) ((mm_segment_t) { (s) }) 43 44# ifndef CONFIG_MMU 45# define KERNEL_DS MAKE_MM_SEG(0) 46# define USER_DS KERNEL_DS 47# else 48# define KERNEL_DS MAKE_MM_SEG(0xFFFFFFFF) 49# define USER_DS MAKE_MM_SEG(TASK_SIZE - 1) 50# endif 51 52# define get_ds() (KERNEL_DS) 53# define get_fs() (current_thread_info()->addr_limit) 54# define set_fs(val) (current_thread_info()->addr_limit = (val)) 55 56# define segment_eq(a, b) ((a).seg == (b).seg) 57 58/* 59 * The exception table consists of pairs of addresses: the first is the 60 * address of an instruction that is allowed to fault, and the second is 61 * the address at which the program should continue. No registers are 62 * modified, so it is entirely up to the continuation code to figure out 63 * what to do. 64 * 65 * All the routines below use bits of fixup code that are out of line 66 * with the main instruction path. This means when everything is well, 67 * we don't even have to jump over them. Further, they do not intrude 68 * on our cache or tlb entries. 69 */ 70struct exception_table_entry { 71 unsigned long insn, fixup; 72}; 73 74/* Returns 0 if exception not found and fixup otherwise. */ 75extern unsigned long search_exception_table(unsigned long); 76 77#ifndef CONFIG_MMU 78 79/* Check against bounds of physical memory */ 80static inline int ___range_ok(unsigned long addr, unsigned long size) 81{ 82 return ((addr < memory_start) || 83 ((addr + size) > memory_end)); 84} 85 86#define __range_ok(addr, size) \ 87 ___range_ok((unsigned long)(addr), (unsigned long)(size)) 88 89#define access_ok(type, addr, size) (__range_ok((addr), (size)) == 0) 90 91#else 92 93/* 94 * Address is valid if: 95 * - "addr", "addr + size" and "size" are all below the limit 96 */ 97#define access_ok(type, addr, size) \ 98 (get_fs().seg > (((unsigned long)(addr)) | \ 99 (size) | ((unsigned long)(addr) + (size)))) 100 101/* || printk("access_ok failed for %s at 0x%08lx (size %d), seg 0x%08x\n", 102 type?"WRITE":"READ",addr,size,get_fs().seg)) */ 103 104#endif 105 106#ifdef CONFIG_MMU 107# define __FIXUP_SECTION ".section .fixup,\"ax\"\n" 108# define __EX_TABLE_SECTION ".section __ex_table,\"a\"\n" 109#else 110# define __FIXUP_SECTION ".section .discard,\"ax\"\n" 111# define __EX_TABLE_SECTION ".section .discard,\"a\"\n" 112#endif 113 114extern unsigned long __copy_tofrom_user(void __user *to, 115 const void __user *from, unsigned long size); 116 117/* Return: number of not copied bytes, i.e. 0 if OK or non-zero if fail. */ 118static inline unsigned long __must_check __clear_user(void __user *to, 119 unsigned long n) 120{ 121 /* normal memset with two words to __ex_table */ 122 __asm__ __volatile__ ( \ 123 "1: sb r0, %2, r0;" \ 124 " addik %0, %0, -1;" \ 125 " bneid %0, 1b;" \ 126 " addik %2, %2, 1;" \ 127 "2: " \ 128 __EX_TABLE_SECTION \ 129 ".word 1b,2b;" \ 130 ".previous;" \ 131 : "=r"(n) \ 132 : "0"(n), "r"(to) 133 ); 134 return n; 135} 136 137static inline unsigned long __must_check clear_user(void __user *to, 138 unsigned long n) 139{ 140 might_sleep(); 141 if (unlikely(!access_ok(VERIFY_WRITE, to, n))) 142 return n; 143 144 return __clear_user(to, n); 145} 146 147/* put_user and get_user macros */ 148extern long __user_bad(void); 149 150#define __get_user_asm(insn, __gu_ptr, __gu_val, __gu_err) \ 151({ \ 152 __asm__ __volatile__ ( \ 153 "1:" insn " %1, %2, r0;" \ 154 " addk %0, r0, r0;" \ 155 "2: " \ 156 __FIXUP_SECTION \ 157 "3: brid 2b;" \ 158 " addik %0, r0, %3;" \ 159 ".previous;" \ 160 __EX_TABLE_SECTION \ 161 ".word 1b,3b;" \ 162 ".previous;" \ 163 : "=&r"(__gu_err), "=r"(__gu_val) \ 164 : "r"(__gu_ptr), "i"(-EFAULT) \ 165 ); \ 166}) 167 168/** 169 * get_user: - Get a simple variable from user space. 170 * @x: Variable to store result. 171 * @ptr: Source address, in user space. 172 * 173 * Context: User context only. This function may sleep. 174 * 175 * This macro copies a single simple variable from user space to kernel 176 * space. It supports simple types like char and int, but not larger 177 * data types like structures or arrays. 178 * 179 * @ptr must have pointer-to-simple-variable type, and the result of 180 * dereferencing @ptr must be assignable to @x without a cast. 181 * 182 * Returns zero on success, or -EFAULT on error. 183 * On error, the variable @x is set to zero. 184 */ 185#define get_user(x, ptr) \ 186 __get_user_check((x), (ptr), sizeof(*(ptr))) 187 188#define __get_user_check(x, ptr, size) \ 189({ \ 190 unsigned long __gu_val = 0; \ 191 const typeof(*(ptr)) __user *__gu_addr = (ptr); \ 192 int __gu_err = 0; \ 193 \ 194 if (access_ok(VERIFY_READ, __gu_addr, size)) { \ 195 switch (size) { \ 196 case 1: \ 197 __get_user_asm("lbu", __gu_addr, __gu_val, \ 198 __gu_err); \ 199 break; \ 200 case 2: \ 201 __get_user_asm("lhu", __gu_addr, __gu_val, \ 202 __gu_err); \ 203 break; \ 204 case 4: \ 205 __get_user_asm("lw", __gu_addr, __gu_val, \ 206 __gu_err); \ 207 break; \ 208 default: \ 209 __gu_err = __user_bad(); \ 210 break; \ 211 } \ 212 } else { \ 213 __gu_err = -EFAULT; \ 214 } \ 215 x = (typeof(*(ptr)))__gu_val; \ 216 __gu_err; \ 217}) 218 219#define __get_user(x, ptr) \ 220({ \ 221 unsigned long __gu_val; \ 222 /*unsigned long __gu_ptr = (unsigned long)(ptr);*/ \ 223 long __gu_err; \ 224 switch (sizeof(*(ptr))) { \ 225 case 1: \ 226 __get_user_asm("lbu", (ptr), __gu_val, __gu_err); \ 227 break; \ 228 case 2: \ 229 __get_user_asm("lhu", (ptr), __gu_val, __gu_err); \ 230 break; \ 231 case 4: \ 232 __get_user_asm("lw", (ptr), __gu_val, __gu_err); \ 233 break; \ 234 default: \ 235 /* __gu_val = 0; __gu_err = -EINVAL;*/ __gu_err = __user_bad();\ 236 } \ 237 x = (__typeof__(*(ptr))) __gu_val; \ 238 __gu_err; \ 239}) 240 241 242#define __put_user_asm(insn, __gu_ptr, __gu_val, __gu_err) \ 243({ \ 244 __asm__ __volatile__ ( \ 245 "1:" insn " %1, %2, r0;" \ 246 " addk %0, r0, r0;" \ 247 "2: " \ 248 __FIXUP_SECTION \ 249 "3: brid 2b;" \ 250 " addik %0, r0, %3;" \ 251 ".previous;" \ 252 __EX_TABLE_SECTION \ 253 ".word 1b,3b;" \ 254 ".previous;" \ 255 : "=&r"(__gu_err) \ 256 : "r"(__gu_val), "r"(__gu_ptr), "i"(-EFAULT) \ 257 ); \ 258}) 259 260#define __put_user_asm_8(__gu_ptr, __gu_val, __gu_err) \ 261({ \ 262 __asm__ __volatile__ (" lwi %0, %1, 0;" \ 263 "1: swi %0, %2, 0;" \ 264 " lwi %0, %1, 4;" \ 265 "2: swi %0, %2, 4;" \ 266 " addk %0, r0, r0;" \ 267 "3: " \ 268 __FIXUP_SECTION \ 269 "4: brid 3b;" \ 270 " addik %0, r0, %3;" \ 271 ".previous;" \ 272 __EX_TABLE_SECTION \ 273 ".word 1b,4b,2b,4b;" \ 274 ".previous;" \ 275 : "=&r"(__gu_err) \ 276 : "r"(&__gu_val), "r"(__gu_ptr), "i"(-EFAULT) \ 277 ); \ 278}) 279 280/** 281 * put_user: - Write a simple value into user space. 282 * @x: Value to copy to user space. 283 * @ptr: Destination address, in user space. 284 * 285 * Context: User context only. This function may sleep. 286 * 287 * This macro copies a single simple value from kernel space to user 288 * space. It supports simple types like char and int, but not larger 289 * data types like structures or arrays. 290 * 291 * @ptr must have pointer-to-simple-variable type, and @x must be assignable 292 * to the result of dereferencing @ptr. 293 * 294 * Returns zero on success, or -EFAULT on error. 295 */ 296#define put_user(x, ptr) \ 297 __put_user_check((x), (ptr), sizeof(*(ptr))) 298 299#define __put_user_check(x, ptr, size) \ 300({ \ 301 typeof(*(ptr)) __pu_val; \ 302 typeof(*(ptr)) __user *__pu_addr = (ptr); \ 303 int __pu_err = 0; \ 304 \ 305 __pu_val = (x); \ 306 if (access_ok(VERIFY_WRITE, __pu_addr, size)) { \ 307 switch (size) { \ 308 case 1: \ 309 __put_user_asm("sb", __pu_addr, __pu_val, \ 310 __pu_err); \ 311 break; \ 312 case 2: \ 313 __put_user_asm("sh", __pu_addr, __pu_val, \ 314 __pu_err); \ 315 break; \ 316 case 4: \ 317 __put_user_asm("sw", __pu_addr, __pu_val, \ 318 __pu_err); \ 319 break; \ 320 case 8: \ 321 __put_user_asm_8(__pu_addr, __pu_val, __pu_err);\ 322 break; \ 323 default: \ 324 __pu_err = __user_bad(); \ 325 break; \ 326 } \ 327 } else { \ 328 __pu_err = -EFAULT; \ 329 } \ 330 __pu_err; \ 331}) 332 333#define __put_user(x, ptr) \ 334({ \ 335 __typeof__(*(ptr)) volatile __gu_val = (x); \ 336 long __gu_err = 0; \ 337 switch (sizeof(__gu_val)) { \ 338 case 1: \ 339 __put_user_asm("sb", (ptr), __gu_val, __gu_err); \ 340 break; \ 341 case 2: \ 342 __put_user_asm("sh", (ptr), __gu_val, __gu_err); \ 343 break; \ 344 case 4: \ 345 __put_user_asm("sw", (ptr), __gu_val, __gu_err); \ 346 break; \ 347 case 8: \ 348 __put_user_asm_8((ptr), __gu_val, __gu_err); \ 349 break; \ 350 default: \ 351 /*__gu_err = -EINVAL;*/ __gu_err = __user_bad(); \ 352 } \ 353 __gu_err; \ 354}) 355 356 357/* copy_to_from_user */ 358#define __copy_from_user(to, from, n) \ 359 __copy_tofrom_user((__force void __user *)(to), \ 360 (void __user *)(from), (n)) 361#define __copy_from_user_inatomic(to, from, n) \ 362 __copy_from_user((to), (from), (n)) 363 364static inline long copy_from_user(void *to, 365 const void __user *from, unsigned long n) 366{ 367 might_sleep(); 368 if (access_ok(VERIFY_READ, from, n)) 369 return __copy_from_user(to, from, n); 370 return n; 371} 372 373#define __copy_to_user(to, from, n) \ 374 __copy_tofrom_user((void __user *)(to), \ 375 (__force const void __user *)(from), (n)) 376#define __copy_to_user_inatomic(to, from, n) __copy_to_user((to), (from), (n)) 377 378static inline long copy_to_user(void __user *to, 379 const void *from, unsigned long n) 380{ 381 might_sleep(); 382 if (access_ok(VERIFY_WRITE, to, n)) 383 return __copy_to_user(to, from, n); 384 return n; 385} 386 387/* 388 * Copy a null terminated string from userspace. 389 */ 390extern int __strncpy_user(char *to, const char __user *from, int len); 391 392#define __strncpy_from_user __strncpy_user 393 394static inline long 395strncpy_from_user(char *dst, const char __user *src, long count) 396{ 397 if (!access_ok(VERIFY_READ, src, 1)) 398 return -EFAULT; 399 return __strncpy_from_user(dst, src, count); 400} 401 402/* 403 * Return the size of a string (including the ending 0) 404 * 405 * Return 0 on exception, a value greater than N if too long 406 */ 407extern int __strnlen_user(const char __user *sstr, int len); 408 409static inline long strnlen_user(const char __user *src, long n) 410{ 411 if (!access_ok(VERIFY_READ, src, 1)) 412 return 0; 413 return __strnlen_user(src, n); 414} 415 416#endif /* __ASSEMBLY__ */ 417#endif /* __KERNEL__ */ 418 419#endif /* _ASM_MICROBLAZE_UACCESS_H */ 420