1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu> 4 * Copyright (C) 2008-2009 PetaLogix 5 * Copyright (C) 2006 Atmark Techno, Inc. 6 */ 7 8 #ifndef _ASM_MICROBLAZE_UACCESS_H 9 #define _ASM_MICROBLAZE_UACCESS_H 10 11 #include <linux/kernel.h> 12 13 #include <asm/mmu.h> 14 #include <asm/page.h> 15 #include <asm/pgtable.h> 16 #include <asm/extable.h> 17 #include <linux/string.h> 18 19 /* 20 * On Microblaze the fs value is actually the top of the corresponding 21 * address space. 22 * 23 * The fs value determines whether argument validity checking should be 24 * performed or not. If get_fs() == USER_DS, checking is performed, with 25 * get_fs() == KERNEL_DS, checking is bypassed. 26 * 27 * For historical reasons, these macros are grossly misnamed. 28 * 29 * For non-MMU arch like Microblaze, KERNEL_DS and USER_DS is equal. 30 */ 31 # define MAKE_MM_SEG(s) ((mm_segment_t) { (s) }) 32 33 # ifndef CONFIG_MMU 34 # define KERNEL_DS MAKE_MM_SEG(0) 35 # define USER_DS KERNEL_DS 36 # else 37 # define KERNEL_DS MAKE_MM_SEG(0xFFFFFFFF) 38 # define USER_DS MAKE_MM_SEG(TASK_SIZE - 1) 39 # endif 40 41 # define get_fs() (current_thread_info()->addr_limit) 42 # define set_fs(val) (current_thread_info()->addr_limit = (val)) 43 44 # define segment_eq(a, b) ((a).seg == (b).seg) 45 46 #ifndef CONFIG_MMU 47 48 /* Check against bounds of physical memory */ 49 static inline int ___range_ok(unsigned long addr, unsigned long size) 50 { 51 return ((addr < memory_start) || 52 ((addr + size - 1) > (memory_start + memory_size - 1))); 53 } 54 55 #define __range_ok(addr, size) \ 56 ___range_ok((unsigned long)(addr), (unsigned long)(size)) 57 58 #define access_ok(addr, size) (__range_ok((addr), (size)) == 0) 59 60 #else 61 62 static inline int access_ok(const void __user *addr, unsigned long size) 63 { 64 if (!size) 65 goto ok; 66 67 if ((get_fs().seg < ((unsigned long)addr)) || 68 (get_fs().seg < ((unsigned long)addr + size - 1))) { 69 pr_devel("ACCESS fail at 0x%08x (size 0x%x), seg 0x%08x\n", 70 (__force u32)addr, (u32)size, 71 (u32)get_fs().seg); 72 return 0; 73 } 74 ok: 75 pr_devel("ACCESS OK at 0x%08x (size 0x%x), seg 0x%08x\n", 76 (__force u32)addr, (u32)size, 77 (u32)get_fs().seg); 78 return 1; 79 } 80 #endif 81 82 #ifdef CONFIG_MMU 83 # define __FIXUP_SECTION ".section .fixup,\"ax\"\n" 84 # define __EX_TABLE_SECTION ".section __ex_table,\"a\"\n" 85 #else 86 # define __FIXUP_SECTION ".section .discard,\"ax\"\n" 87 # define __EX_TABLE_SECTION ".section .discard,\"ax\"\n" 88 #endif 89 90 extern unsigned long __copy_tofrom_user(void __user *to, 91 const void __user *from, unsigned long size); 92 93 /* Return: number of not copied bytes, i.e. 0 if OK or non-zero if fail. */ 94 static inline unsigned long __must_check __clear_user(void __user *to, 95 unsigned long n) 96 { 97 /* normal memset with two words to __ex_table */ 98 __asm__ __volatile__ ( \ 99 "1: sb r0, %1, r0;" \ 100 " addik %0, %0, -1;" \ 101 " bneid %0, 1b;" \ 102 " addik %1, %1, 1;" \ 103 "2: " \ 104 __EX_TABLE_SECTION \ 105 ".word 1b,2b;" \ 106 ".previous;" \ 107 : "=r"(n), "=r"(to) \ 108 : "0"(n), "1"(to) 109 ); 110 return n; 111 } 112 113 static inline unsigned long __must_check clear_user(void __user *to, 114 unsigned long n) 115 { 116 might_fault(); 117 if (unlikely(!access_ok(to, n))) 118 return n; 119 120 return __clear_user(to, n); 121 } 122 123 /* put_user and get_user macros */ 124 extern long __user_bad(void); 125 126 #define __get_user_asm(insn, __gu_ptr, __gu_val, __gu_err) \ 127 ({ \ 128 __asm__ __volatile__ ( \ 129 "1:" insn " %1, %2, r0;" \ 130 " addk %0, r0, r0;" \ 131 "2: " \ 132 __FIXUP_SECTION \ 133 "3: brid 2b;" \ 134 " addik %0, r0, %3;" \ 135 ".previous;" \ 136 __EX_TABLE_SECTION \ 137 ".word 1b,3b;" \ 138 ".previous;" \ 139 : "=&r"(__gu_err), "=r"(__gu_val) \ 140 : "r"(__gu_ptr), "i"(-EFAULT) \ 141 ); \ 142 }) 143 144 /** 145 * get_user: - Get a simple variable from user space. 146 * @x: Variable to store result. 147 * @ptr: Source address, in user space. 148 * 149 * Context: User context only. This function may sleep if pagefaults are 150 * enabled. 151 * 152 * This macro copies a single simple variable from user space to kernel 153 * space. It supports simple types like char and int, but not larger 154 * data types like structures or arrays. 155 * 156 * @ptr must have pointer-to-simple-variable type, and the result of 157 * dereferencing @ptr must be assignable to @x without a cast. 158 * 159 * Returns zero on success, or -EFAULT on error. 160 * On error, the variable @x is set to zero. 161 */ 162 #define get_user(x, ptr) ({ \ 163 const typeof(*(ptr)) __user *__gu_ptr = (ptr); \ 164 access_ok(__gu_ptr, sizeof(*__gu_ptr)) ? \ 165 __get_user(x, __gu_ptr) : -EFAULT; \ 166 }) 167 168 #define __get_user(x, ptr) \ 169 ({ \ 170 unsigned long __gu_val = 0; \ 171 long __gu_err; \ 172 switch (sizeof(*(ptr))) { \ 173 case 1: \ 174 __get_user_asm("lbu", (ptr), __gu_val, __gu_err); \ 175 break; \ 176 case 2: \ 177 __get_user_asm("lhu", (ptr), __gu_val, __gu_err); \ 178 break; \ 179 case 4: \ 180 __get_user_asm("lw", (ptr), __gu_val, __gu_err); \ 181 break; \ 182 case 8: \ 183 __gu_err = __copy_from_user(&__gu_val, ptr, 8); \ 184 if (__gu_err) \ 185 __gu_err = -EFAULT; \ 186 break; \ 187 default: \ 188 /* __gu_val = 0; __gu_err = -EINVAL;*/ __gu_err = __user_bad();\ 189 } \ 190 x = (__force __typeof__(*(ptr))) __gu_val; \ 191 __gu_err; \ 192 }) 193 194 195 #define __put_user_asm(insn, __gu_ptr, __gu_val, __gu_err) \ 196 ({ \ 197 __asm__ __volatile__ ( \ 198 "1:" insn " %1, %2, r0;" \ 199 " addk %0, r0, r0;" \ 200 "2: " \ 201 __FIXUP_SECTION \ 202 "3: brid 2b;" \ 203 " addik %0, r0, %3;" \ 204 ".previous;" \ 205 __EX_TABLE_SECTION \ 206 ".word 1b,3b;" \ 207 ".previous;" \ 208 : "=&r"(__gu_err) \ 209 : "r"(__gu_val), "r"(__gu_ptr), "i"(-EFAULT) \ 210 ); \ 211 }) 212 213 #define __put_user_asm_8(__gu_ptr, __gu_val, __gu_err) \ 214 ({ \ 215 __asm__ __volatile__ (" lwi %0, %1, 0;" \ 216 "1: swi %0, %2, 0;" \ 217 " lwi %0, %1, 4;" \ 218 "2: swi %0, %2, 4;" \ 219 " addk %0, r0, r0;" \ 220 "3: " \ 221 __FIXUP_SECTION \ 222 "4: brid 3b;" \ 223 " addik %0, r0, %3;" \ 224 ".previous;" \ 225 __EX_TABLE_SECTION \ 226 ".word 1b,4b,2b,4b;" \ 227 ".previous;" \ 228 : "=&r"(__gu_err) \ 229 : "r"(&__gu_val), "r"(__gu_ptr), "i"(-EFAULT) \ 230 ); \ 231 }) 232 233 /** 234 * put_user: - Write a simple value into user space. 235 * @x: Value to copy to user space. 236 * @ptr: Destination address, in user space. 237 * 238 * Context: User context only. This function may sleep if pagefaults are 239 * enabled. 240 * 241 * This macro copies a single simple value from kernel space to user 242 * space. It supports simple types like char and int, but not larger 243 * data types like structures or arrays. 244 * 245 * @ptr must have pointer-to-simple-variable type, and @x must be assignable 246 * to the result of dereferencing @ptr. 247 * 248 * Returns zero on success, or -EFAULT on error. 249 */ 250 #define put_user(x, ptr) \ 251 __put_user_check((x), (ptr), sizeof(*(ptr))) 252 253 #define __put_user_check(x, ptr, size) \ 254 ({ \ 255 typeof(*(ptr)) volatile __pu_val = x; \ 256 typeof(*(ptr)) __user *__pu_addr = (ptr); \ 257 int __pu_err = 0; \ 258 \ 259 if (access_ok(__pu_addr, size)) { \ 260 switch (size) { \ 261 case 1: \ 262 __put_user_asm("sb", __pu_addr, __pu_val, \ 263 __pu_err); \ 264 break; \ 265 case 2: \ 266 __put_user_asm("sh", __pu_addr, __pu_val, \ 267 __pu_err); \ 268 break; \ 269 case 4: \ 270 __put_user_asm("sw", __pu_addr, __pu_val, \ 271 __pu_err); \ 272 break; \ 273 case 8: \ 274 __put_user_asm_8(__pu_addr, __pu_val, __pu_err);\ 275 break; \ 276 default: \ 277 __pu_err = __user_bad(); \ 278 break; \ 279 } \ 280 } else { \ 281 __pu_err = -EFAULT; \ 282 } \ 283 __pu_err; \ 284 }) 285 286 #define __put_user(x, ptr) \ 287 ({ \ 288 __typeof__(*(ptr)) volatile __gu_val = (x); \ 289 long __gu_err = 0; \ 290 switch (sizeof(__gu_val)) { \ 291 case 1: \ 292 __put_user_asm("sb", (ptr), __gu_val, __gu_err); \ 293 break; \ 294 case 2: \ 295 __put_user_asm("sh", (ptr), __gu_val, __gu_err); \ 296 break; \ 297 case 4: \ 298 __put_user_asm("sw", (ptr), __gu_val, __gu_err); \ 299 break; \ 300 case 8: \ 301 __put_user_asm_8((ptr), __gu_val, __gu_err); \ 302 break; \ 303 default: \ 304 /*__gu_err = -EINVAL;*/ __gu_err = __user_bad(); \ 305 } \ 306 __gu_err; \ 307 }) 308 309 static inline unsigned long 310 raw_copy_from_user(void *to, const void __user *from, unsigned long n) 311 { 312 return __copy_tofrom_user((__force void __user *)to, from, n); 313 } 314 315 static inline unsigned long 316 raw_copy_to_user(void __user *to, const void *from, unsigned long n) 317 { 318 return __copy_tofrom_user(to, (__force const void __user *)from, n); 319 } 320 #define INLINE_COPY_FROM_USER 321 #define INLINE_COPY_TO_USER 322 323 /* 324 * Copy a null terminated string from userspace. 325 */ 326 extern int __strncpy_user(char *to, const char __user *from, int len); 327 328 static inline long 329 strncpy_from_user(char *dst, const char __user *src, long count) 330 { 331 if (!access_ok(src, 1)) 332 return -EFAULT; 333 return __strncpy_user(dst, src, count); 334 } 335 336 /* 337 * Return the size of a string (including the ending 0) 338 * 339 * Return 0 on exception, a value greater than N if too long 340 */ 341 extern int __strnlen_user(const char __user *sstr, int len); 342 343 static inline long strnlen_user(const char __user *src, long n) 344 { 345 if (!access_ok(src, 1)) 346 return 0; 347 return __strnlen_user(src, n); 348 } 349 350 #endif /* _ASM_MICROBLAZE_UACCESS_H */ 351