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 */ 70 struct exception_table_entry { 71 unsigned long insn, fixup; 72 }; 73 74 /* Returns 0 if exception not found and fixup otherwise. */ 75 extern unsigned long search_exception_table(unsigned long); 76 77 #ifndef CONFIG_MMU 78 79 /* Check against bounds of physical memory */ 80 static 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 113 114 extern 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. */ 118 static 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 } 136 137 static 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 */ 148 extern 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 */ 185 186 #define __get_user(x, ptr) \ 187 ({ \ 188 unsigned long __gu_val; \ 189 /*unsigned long __gu_ptr = (unsigned long)(ptr);*/ \ 190 long __gu_err; \ 191 switch (sizeof(*(ptr))) { \ 192 case 1: \ 193 __get_user_asm("lbu", (ptr), __gu_val, __gu_err); \ 194 break; \ 195 case 2: \ 196 __get_user_asm("lhu", (ptr), __gu_val, __gu_err); \ 197 break; \ 198 case 4: \ 199 __get_user_asm("lw", (ptr), __gu_val, __gu_err); \ 200 break; \ 201 default: \ 202 /* __gu_val = 0; __gu_err = -EINVAL;*/ __gu_err = __user_bad();\ 203 } \ 204 x = (__typeof__(*(ptr))) __gu_val; \ 205 __gu_err; \ 206 }) 207 208 209 #define get_user(x, ptr) \ 210 ({ \ 211 access_ok(VERIFY_READ, (ptr), sizeof(*(ptr))) \ 212 ? __get_user((x), (ptr)) : -EFAULT; \ 213 }) 214 215 #define __put_user_asm(insn, __gu_ptr, __gu_val, __gu_err) \ 216 ({ \ 217 __asm__ __volatile__ ( \ 218 "1:" insn " %1, %2, r0;" \ 219 " addk %0, r0, r0;" \ 220 "2: " \ 221 __FIXUP_SECTION \ 222 "3: brid 2b;" \ 223 " addik %0, r0, %3;" \ 224 ".previous;" \ 225 __EX_TABLE_SECTION \ 226 ".word 1b,3b;" \ 227 ".previous;" \ 228 : "=&r"(__gu_err) \ 229 : "r"(__gu_val), "r"(__gu_ptr), "i"(-EFAULT) \ 230 ); \ 231 }) 232 233 #define __put_user_asm_8(__gu_ptr, __gu_val, __gu_err) \ 234 ({ \ 235 __asm__ __volatile__ (" lwi %0, %1, 0;" \ 236 "1: swi %0, %2, 0;" \ 237 " lwi %0, %1, 4;" \ 238 "2: swi %0, %2, 4;" \ 239 " addk %0, r0, r0;" \ 240 "3: " \ 241 __FIXUP_SECTION \ 242 "4: brid 3b;" \ 243 " addik %0, r0, %3;" \ 244 ".previous;" \ 245 __EX_TABLE_SECTION \ 246 ".word 1b,4b,2b,4b;" \ 247 ".previous;" \ 248 : "=&r"(__gu_err) \ 249 : "r"(&__gu_val), "r"(__gu_ptr), "i"(-EFAULT) \ 250 ); \ 251 }) 252 253 /** 254 * put_user: - Write a simple value into user space. 255 * @x: Value to copy to user space. 256 * @ptr: Destination address, in user space. 257 * 258 * Context: User context only. This function may sleep. 259 * 260 * This macro copies a single simple value from kernel space to user 261 * space. It supports simple types like char and int, but not larger 262 * data types like structures or arrays. 263 * 264 * @ptr must have pointer-to-simple-variable type, and @x must be assignable 265 * to the result of dereferencing @ptr. 266 * 267 * Returns zero on success, or -EFAULT on error. 268 */ 269 270 #define __put_user(x, ptr) \ 271 ({ \ 272 __typeof__(*(ptr)) volatile __gu_val = (x); \ 273 long __gu_err = 0; \ 274 switch (sizeof(__gu_val)) { \ 275 case 1: \ 276 __put_user_asm("sb", (ptr), __gu_val, __gu_err); \ 277 break; \ 278 case 2: \ 279 __put_user_asm("sh", (ptr), __gu_val, __gu_err); \ 280 break; \ 281 case 4: \ 282 __put_user_asm("sw", (ptr), __gu_val, __gu_err); \ 283 break; \ 284 case 8: \ 285 __put_user_asm_8((ptr), __gu_val, __gu_err); \ 286 break; \ 287 default: \ 288 /*__gu_err = -EINVAL;*/ __gu_err = __user_bad(); \ 289 } \ 290 __gu_err; \ 291 }) 292 293 #ifndef CONFIG_MMU 294 295 #define put_user(x, ptr) __put_user((x), (ptr)) 296 297 #else /* CONFIG_MMU */ 298 299 #define put_user(x, ptr) \ 300 ({ \ 301 access_ok(VERIFY_WRITE, (ptr), sizeof(*(ptr))) \ 302 ? __put_user((x), (ptr)) : -EFAULT; \ 303 }) 304 #endif /* CONFIG_MMU */ 305 306 /* copy_to_from_user */ 307 #define __copy_from_user(to, from, n) \ 308 __copy_tofrom_user((__force void __user *)(to), \ 309 (void __user *)(from), (n)) 310 #define __copy_from_user_inatomic(to, from, n) \ 311 copy_from_user((to), (from), (n)) 312 313 static inline long copy_from_user(void *to, 314 const void __user *from, unsigned long n) 315 { 316 might_sleep(); 317 if (access_ok(VERIFY_READ, from, n)) 318 return __copy_from_user(to, from, n); 319 return n; 320 } 321 322 #define __copy_to_user(to, from, n) \ 323 __copy_tofrom_user((void __user *)(to), \ 324 (__force const void __user *)(from), (n)) 325 #define __copy_to_user_inatomic(to, from, n) copy_to_user((to), (from), (n)) 326 327 static inline long copy_to_user(void __user *to, 328 const void *from, unsigned long n) 329 { 330 might_sleep(); 331 if (access_ok(VERIFY_WRITE, to, n)) 332 return __copy_to_user(to, from, n); 333 return n; 334 } 335 336 /* 337 * Copy a null terminated string from userspace. 338 */ 339 extern int __strncpy_user(char *to, const char __user *from, int len); 340 341 #define __strncpy_from_user __strncpy_user 342 343 static inline long 344 strncpy_from_user(char *dst, const char __user *src, long count) 345 { 346 if (!access_ok(VERIFY_READ, src, 1)) 347 return -EFAULT; 348 return __strncpy_from_user(dst, src, count); 349 } 350 351 /* 352 * Return the size of a string (including the ending 0) 353 * 354 * Return 0 on exception, a value greater than N if too long 355 */ 356 extern int __strnlen_user(const char __user *sstr, int len); 357 358 static inline long strnlen_user(const char __user *src, long n) 359 { 360 if (!access_ok(VERIFY_READ, src, 1)) 361 return 0; 362 return __strnlen_user(src, n); 363 } 364 365 #endif /* __ASSEMBLY__ */ 366 #endif /* __KERNEL__ */ 367 368 #endif /* _ASM_MICROBLAZE_UACCESS_H */ 369