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