1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Standard user space access functions based on mvcp/mvcs and doing 4 * interesting things in the secondary space mode. 5 * 6 * Copyright IBM Corp. 2006,2014 7 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com), 8 * Gerald Schaefer (gerald.schaefer@de.ibm.com) 9 */ 10 11 #include <linux/jump_label.h> 12 #include <linux/uaccess.h> 13 #include <linux/export.h> 14 #include <linux/errno.h> 15 #include <linux/mm.h> 16 #include <asm/mmu_context.h> 17 #include <asm/facility.h> 18 19 #ifdef CONFIG_DEBUG_USER_ASCE 20 void debug_user_asce(void) 21 { 22 unsigned long cr1, cr7; 23 24 __ctl_store(cr1, 1, 1); 25 __ctl_store(cr7, 7, 7); 26 if (cr1 == S390_lowcore.kernel_asce && cr7 == S390_lowcore.user_asce) 27 return; 28 panic("incorrect ASCE on kernel exit\n" 29 "cr1: %016lx cr7: %016lx\n" 30 "kernel: %016llx user: %016llx\n", 31 cr1, cr7, S390_lowcore.kernel_asce, S390_lowcore.user_asce); 32 } 33 #endif /*CONFIG_DEBUG_USER_ASCE */ 34 35 #ifndef CONFIG_HAVE_MARCH_Z10_FEATURES 36 static DEFINE_STATIC_KEY_FALSE(have_mvcos); 37 38 static int __init uaccess_init(void) 39 { 40 if (test_facility(27)) 41 static_branch_enable(&have_mvcos); 42 return 0; 43 } 44 early_initcall(uaccess_init); 45 46 static inline int copy_with_mvcos(void) 47 { 48 if (static_branch_likely(&have_mvcos)) 49 return 1; 50 return 0; 51 } 52 #else 53 static inline int copy_with_mvcos(void) 54 { 55 return 1; 56 } 57 #endif 58 59 static inline unsigned long copy_from_user_mvcos(void *x, const void __user *ptr, 60 unsigned long size) 61 { 62 register unsigned long reg0 asm("0") = 0x81UL; 63 unsigned long tmp1, tmp2; 64 65 tmp1 = -4096UL; 66 asm volatile( 67 "0: .insn ss,0xc80000000000,0(%0,%2),0(%1),0\n" 68 "6: jz 4f\n" 69 "1: algr %0,%3\n" 70 " slgr %1,%3\n" 71 " slgr %2,%3\n" 72 " j 0b\n" 73 "2: la %4,4095(%1)\n"/* %4 = ptr + 4095 */ 74 " nr %4,%3\n" /* %4 = (ptr + 4095) & -4096 */ 75 " slgr %4,%1\n" 76 " clgr %0,%4\n" /* copy crosses next page boundary? */ 77 " jnh 5f\n" 78 "3: .insn ss,0xc80000000000,0(%4,%2),0(%1),0\n" 79 "7: slgr %0,%4\n" 80 " j 5f\n" 81 "4: slgr %0,%0\n" 82 "5:\n" 83 EX_TABLE(0b,2b) EX_TABLE(3b,5b) EX_TABLE(6b,2b) EX_TABLE(7b,5b) 84 : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2) 85 : "d" (reg0) : "cc", "memory"); 86 return size; 87 } 88 89 static inline unsigned long copy_from_user_mvcp(void *x, const void __user *ptr, 90 unsigned long size) 91 { 92 unsigned long tmp1, tmp2; 93 94 tmp1 = -256UL; 95 asm volatile( 96 " sacf 0\n" 97 "0: mvcp 0(%0,%2),0(%1),%3\n" 98 "7: jz 5f\n" 99 "1: algr %0,%3\n" 100 " la %1,256(%1)\n" 101 " la %2,256(%2)\n" 102 "2: mvcp 0(%0,%2),0(%1),%3\n" 103 "8: jnz 1b\n" 104 " j 5f\n" 105 "3: la %4,255(%1)\n" /* %4 = ptr + 255 */ 106 " lghi %3,-4096\n" 107 " nr %4,%3\n" /* %4 = (ptr + 255) & -4096 */ 108 " slgr %4,%1\n" 109 " clgr %0,%4\n" /* copy crosses next page boundary? */ 110 " jnh 6f\n" 111 "4: mvcp 0(%4,%2),0(%1),%3\n" 112 "9: slgr %0,%4\n" 113 " j 6f\n" 114 "5: slgr %0,%0\n" 115 "6: sacf 768\n" 116 EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,6b) 117 EX_TABLE(7b,3b) EX_TABLE(8b,3b) EX_TABLE(9b,6b) 118 : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2) 119 : : "cc", "memory"); 120 return size; 121 } 122 123 unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n) 124 { 125 if (copy_with_mvcos()) 126 return copy_from_user_mvcos(to, from, n); 127 return copy_from_user_mvcp(to, from, n); 128 } 129 EXPORT_SYMBOL(raw_copy_from_user); 130 131 static inline unsigned long copy_to_user_mvcos(void __user *ptr, const void *x, 132 unsigned long size) 133 { 134 register unsigned long reg0 asm("0") = 0x810000UL; 135 unsigned long tmp1, tmp2; 136 137 tmp1 = -4096UL; 138 asm volatile( 139 "0: .insn ss,0xc80000000000,0(%0,%1),0(%2),0\n" 140 "6: jz 4f\n" 141 "1: algr %0,%3\n" 142 " slgr %1,%3\n" 143 " slgr %2,%3\n" 144 " j 0b\n" 145 "2: la %4,4095(%1)\n"/* %4 = ptr + 4095 */ 146 " nr %4,%3\n" /* %4 = (ptr + 4095) & -4096 */ 147 " slgr %4,%1\n" 148 " clgr %0,%4\n" /* copy crosses next page boundary? */ 149 " jnh 5f\n" 150 "3: .insn ss,0xc80000000000,0(%4,%1),0(%2),0\n" 151 "7: slgr %0,%4\n" 152 " j 5f\n" 153 "4: slgr %0,%0\n" 154 "5:\n" 155 EX_TABLE(0b,2b) EX_TABLE(3b,5b) EX_TABLE(6b,2b) EX_TABLE(7b,5b) 156 : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2) 157 : "d" (reg0) : "cc", "memory"); 158 return size; 159 } 160 161 static inline unsigned long copy_to_user_mvcs(void __user *ptr, const void *x, 162 unsigned long size) 163 { 164 unsigned long tmp1, tmp2; 165 166 tmp1 = -256UL; 167 asm volatile( 168 " sacf 0\n" 169 "0: mvcs 0(%0,%1),0(%2),%3\n" 170 "7: jz 5f\n" 171 "1: algr %0,%3\n" 172 " la %1,256(%1)\n" 173 " la %2,256(%2)\n" 174 "2: mvcs 0(%0,%1),0(%2),%3\n" 175 "8: jnz 1b\n" 176 " j 5f\n" 177 "3: la %4,255(%1)\n" /* %4 = ptr + 255 */ 178 " lghi %3,-4096\n" 179 " nr %4,%3\n" /* %4 = (ptr + 255) & -4096 */ 180 " slgr %4,%1\n" 181 " clgr %0,%4\n" /* copy crosses next page boundary? */ 182 " jnh 6f\n" 183 "4: mvcs 0(%4,%1),0(%2),%3\n" 184 "9: slgr %0,%4\n" 185 " j 6f\n" 186 "5: slgr %0,%0\n" 187 "6: sacf 768\n" 188 EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,6b) 189 EX_TABLE(7b,3b) EX_TABLE(8b,3b) EX_TABLE(9b,6b) 190 : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2) 191 : : "cc", "memory"); 192 return size; 193 } 194 195 unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n) 196 { 197 if (copy_with_mvcos()) 198 return copy_to_user_mvcos(to, from, n); 199 return copy_to_user_mvcs(to, from, n); 200 } 201 EXPORT_SYMBOL(raw_copy_to_user); 202 203 static inline unsigned long copy_in_user_mvcos(void __user *to, const void __user *from, 204 unsigned long size) 205 { 206 register unsigned long reg0 asm("0") = 0x810081UL; 207 unsigned long tmp1, tmp2; 208 209 tmp1 = -4096UL; 210 /* FIXME: copy with reduced length. */ 211 asm volatile( 212 "0: .insn ss,0xc80000000000,0(%0,%1),0(%2),0\n" 213 " jz 2f\n" 214 "1: algr %0,%3\n" 215 " slgr %1,%3\n" 216 " slgr %2,%3\n" 217 " j 0b\n" 218 "2:slgr %0,%0\n" 219 "3: \n" 220 EX_TABLE(0b,3b) 221 : "+a" (size), "+a" (to), "+a" (from), "+a" (tmp1), "=a" (tmp2) 222 : "d" (reg0) : "cc", "memory"); 223 return size; 224 } 225 226 static inline unsigned long copy_in_user_mvc(void __user *to, const void __user *from, 227 unsigned long size) 228 { 229 unsigned long tmp1; 230 231 asm volatile( 232 " sacf 256\n" 233 " aghi %0,-1\n" 234 " jo 5f\n" 235 " bras %3,3f\n" 236 "0: aghi %0,257\n" 237 "1: mvc 0(1,%1),0(%2)\n" 238 " la %1,1(%1)\n" 239 " la %2,1(%2)\n" 240 " aghi %0,-1\n" 241 " jnz 1b\n" 242 " j 5f\n" 243 "2: mvc 0(256,%1),0(%2)\n" 244 " la %1,256(%1)\n" 245 " la %2,256(%2)\n" 246 "3: aghi %0,-256\n" 247 " jnm 2b\n" 248 "4: ex %0,1b-0b(%3)\n" 249 "5: slgr %0,%0\n" 250 "6: sacf 768\n" 251 EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b) 252 : "+a" (size), "+a" (to), "+a" (from), "=a" (tmp1) 253 : : "cc", "memory"); 254 return size; 255 } 256 257 unsigned long raw_copy_in_user(void __user *to, const void __user *from, unsigned long n) 258 { 259 if (copy_with_mvcos()) 260 return copy_in_user_mvcos(to, from, n); 261 return copy_in_user_mvc(to, from, n); 262 } 263 EXPORT_SYMBOL(raw_copy_in_user); 264 265 static inline unsigned long clear_user_mvcos(void __user *to, unsigned long size) 266 { 267 register unsigned long reg0 asm("0") = 0x810000UL; 268 unsigned long tmp1, tmp2; 269 270 tmp1 = -4096UL; 271 asm volatile( 272 "0: .insn ss,0xc80000000000,0(%0,%1),0(%4),0\n" 273 " jz 4f\n" 274 "1: algr %0,%2\n" 275 " slgr %1,%2\n" 276 " j 0b\n" 277 "2: la %3,4095(%1)\n"/* %4 = to + 4095 */ 278 " nr %3,%2\n" /* %4 = (to + 4095) & -4096 */ 279 " slgr %3,%1\n" 280 " clgr %0,%3\n" /* copy crosses next page boundary? */ 281 " jnh 5f\n" 282 "3: .insn ss,0xc80000000000,0(%3,%1),0(%4),0\n" 283 " slgr %0,%3\n" 284 " j 5f\n" 285 "4: slgr %0,%0\n" 286 "5:\n" 287 EX_TABLE(0b,2b) EX_TABLE(3b,5b) 288 : "+a" (size), "+a" (to), "+a" (tmp1), "=a" (tmp2) 289 : "a" (empty_zero_page), "d" (reg0) : "cc", "memory"); 290 return size; 291 } 292 293 static inline unsigned long clear_user_xc(void __user *to, unsigned long size) 294 { 295 unsigned long tmp1, tmp2; 296 297 asm volatile( 298 " sacf 256\n" 299 " aghi %0,-1\n" 300 " jo 5f\n" 301 " bras %3,3f\n" 302 " xc 0(1,%1),0(%1)\n" 303 "0: aghi %0,257\n" 304 " la %2,255(%1)\n" /* %2 = ptr + 255 */ 305 " srl %2,12\n" 306 " sll %2,12\n" /* %2 = (ptr + 255) & -4096 */ 307 " slgr %2,%1\n" 308 " clgr %0,%2\n" /* clear crosses next page boundary? */ 309 " jnh 5f\n" 310 " aghi %2,-1\n" 311 "1: ex %2,0(%3)\n" 312 " aghi %2,1\n" 313 " slgr %0,%2\n" 314 " j 5f\n" 315 "2: xc 0(256,%1),0(%1)\n" 316 " la %1,256(%1)\n" 317 "3: aghi %0,-256\n" 318 " jnm 2b\n" 319 "4: ex %0,0(%3)\n" 320 "5: slgr %0,%0\n" 321 "6: sacf 768\n" 322 EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b) 323 : "+a" (size), "+a" (to), "=a" (tmp1), "=a" (tmp2) 324 : : "cc", "memory"); 325 return size; 326 } 327 328 unsigned long __clear_user(void __user *to, unsigned long size) 329 { 330 if (copy_with_mvcos()) 331 return clear_user_mvcos(to, size); 332 return clear_user_xc(to, size); 333 } 334 EXPORT_SYMBOL(__clear_user); 335 336 static inline unsigned long strnlen_user_srst(const char __user *src, 337 unsigned long size) 338 { 339 register unsigned long reg0 asm("0") = 0; 340 unsigned long tmp1, tmp2; 341 342 asm volatile( 343 " la %2,0(%1)\n" 344 " la %3,0(%0,%1)\n" 345 " slgr %0,%0\n" 346 " sacf 256\n" 347 "0: srst %3,%2\n" 348 " jo 0b\n" 349 " la %0,1(%3)\n" /* strnlen_user results includes \0 */ 350 " slgr %0,%1\n" 351 "1: sacf 768\n" 352 EX_TABLE(0b,1b) 353 : "+a" (size), "+a" (src), "=a" (tmp1), "=a" (tmp2) 354 : "d" (reg0) : "cc", "memory"); 355 return size; 356 } 357 358 unsigned long __strnlen_user(const char __user *src, unsigned long size) 359 { 360 if (unlikely(!size)) 361 return 0; 362 return strnlen_user_srst(src, size); 363 } 364 EXPORT_SYMBOL(__strnlen_user); 365 366 long __strncpy_from_user(char *dst, const char __user *src, long size) 367 { 368 size_t done, len, offset, len_str; 369 370 if (unlikely(size <= 0)) 371 return 0; 372 done = 0; 373 do { 374 offset = (size_t)src & (L1_CACHE_BYTES - 1); 375 len = min(size - done, L1_CACHE_BYTES - offset); 376 if (copy_from_user(dst, src, len)) 377 return -EFAULT; 378 len_str = strnlen(dst, len); 379 done += len_str; 380 src += len_str; 381 dst += len_str; 382 } while ((len_str == len) && (done < size)); 383 return done; 384 } 385 EXPORT_SYMBOL(__strncpy_from_user); 386