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