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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 | // SPDX-License-Identifier: GPL-2.0 /* * Standard user space access functions based on mvcp/mvcs and doing * interesting things in the secondary space mode. * * Copyright IBM Corp. 2006,2014 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com), * Gerald Schaefer (gerald.schaefer@de.ibm.com) */ #include <linux/jump_label.h> #include <linux/uaccess.h> #include <linux/export.h> #include <linux/errno.h> #include <linux/mm.h> #include <asm/mmu_context.h> #include <asm/facility.h> #ifdef CONFIG_DEBUG_ENTRY void debug_user_asce(int exit) { unsigned long cr1, cr7; __ctl_store(cr1, 1, 1); __ctl_store(cr7, 7, 7); if (cr1 == S390_lowcore.kernel_asce && cr7 == S390_lowcore.user_asce) return; panic("incorrect ASCE on kernel %s\n" "cr1: %016lx cr7: %016lx\n" "kernel: %016llx user: %016llx\n", exit ? "exit" : "entry", cr1, cr7, S390_lowcore.kernel_asce, S390_lowcore.user_asce); } #endif /*CONFIG_DEBUG_ENTRY */ #ifndef CONFIG_HAVE_MARCH_Z10_FEATURES static DEFINE_STATIC_KEY_FALSE(have_mvcos); static int __init uaccess_init(void) { if (test_facility(27)) static_branch_enable(&have_mvcos); return 0; } early_initcall(uaccess_init); static inline int copy_with_mvcos(void) { if (static_branch_likely(&have_mvcos)) return 1; return 0; } #else static inline int copy_with_mvcos(void) { return 1; } #endif static inline unsigned long copy_from_user_mvcos(void *x, const void __user *ptr, unsigned long size) { register unsigned long reg0 asm("0") = 0x81UL; unsigned long tmp1, tmp2; tmp1 = -4096UL; asm volatile( "0: .insn ss,0xc80000000000,0(%0,%2),0(%1),0\n" "6: jz 4f\n" "1: algr %0,%3\n" " slgr %1,%3\n" " slgr %2,%3\n" " j 0b\n" "2: la %4,4095(%1)\n"/* %4 = ptr + 4095 */ " nr %4,%3\n" /* %4 = (ptr + 4095) & -4096 */ " slgr %4,%1\n" " clgr %0,%4\n" /* copy crosses next page boundary? */ " jnh 5f\n" "3: .insn ss,0xc80000000000,0(%4,%2),0(%1),0\n" "7: slgr %0,%4\n" " j 5f\n" "4: slgr %0,%0\n" "5:\n" EX_TABLE(0b,2b) EX_TABLE(3b,5b) EX_TABLE(6b,2b) EX_TABLE(7b,5b) : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2) : "d" (reg0) : "cc", "memory"); return size; } static inline unsigned long copy_from_user_mvcp(void *x, const void __user *ptr, unsigned long size) { unsigned long tmp1, tmp2; tmp1 = -256UL; asm volatile( " sacf 0\n" "0: mvcp 0(%0,%2),0(%1),%3\n" "7: jz 5f\n" "1: algr %0,%3\n" " la %1,256(%1)\n" " la %2,256(%2)\n" "2: mvcp 0(%0,%2),0(%1),%3\n" "8: jnz 1b\n" " j 5f\n" "3: la %4,255(%1)\n" /* %4 = ptr + 255 */ " lghi %3,-4096\n" " nr %4,%3\n" /* %4 = (ptr + 255) & -4096 */ " slgr %4,%1\n" " clgr %0,%4\n" /* copy crosses next page boundary? */ " jnh 6f\n" "4: mvcp 0(%4,%2),0(%1),%3\n" "9: slgr %0,%4\n" " j 6f\n" "5: slgr %0,%0\n" "6: sacf 768\n" EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,6b) EX_TABLE(7b,3b) EX_TABLE(8b,3b) EX_TABLE(9b,6b) : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2) : : "cc", "memory"); return size; } unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n) { if (copy_with_mvcos()) return copy_from_user_mvcos(to, from, n); return copy_from_user_mvcp(to, from, n); } EXPORT_SYMBOL(raw_copy_from_user); static inline unsigned long copy_to_user_mvcos(void __user *ptr, const void *x, unsigned long size) { register unsigned long reg0 asm("0") = 0x810000UL; unsigned long tmp1, tmp2; tmp1 = -4096UL; asm volatile( "0: .insn ss,0xc80000000000,0(%0,%1),0(%2),0\n" "6: jz 4f\n" "1: algr %0,%3\n" " slgr %1,%3\n" " slgr %2,%3\n" " j 0b\n" "2: la %4,4095(%1)\n"/* %4 = ptr + 4095 */ " nr %4,%3\n" /* %4 = (ptr + 4095) & -4096 */ " slgr %4,%1\n" " clgr %0,%4\n" /* copy crosses next page boundary? */ " jnh 5f\n" "3: .insn ss,0xc80000000000,0(%4,%1),0(%2),0\n" "7: slgr %0,%4\n" " j 5f\n" "4: slgr %0,%0\n" "5:\n" EX_TABLE(0b,2b) EX_TABLE(3b,5b) EX_TABLE(6b,2b) EX_TABLE(7b,5b) : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2) : "d" (reg0) : "cc", "memory"); return size; } static inline unsigned long copy_to_user_mvcs(void __user *ptr, const void *x, unsigned long size) { unsigned long tmp1, tmp2; tmp1 = -256UL; asm volatile( " sacf 0\n" "0: mvcs 0(%0,%1),0(%2),%3\n" "7: jz 5f\n" "1: algr %0,%3\n" " la %1,256(%1)\n" " la %2,256(%2)\n" "2: mvcs 0(%0,%1),0(%2),%3\n" "8: jnz 1b\n" " j 5f\n" "3: la %4,255(%1)\n" /* %4 = ptr + 255 */ " lghi %3,-4096\n" " nr %4,%3\n" /* %4 = (ptr + 255) & -4096 */ " slgr %4,%1\n" " clgr %0,%4\n" /* copy crosses next page boundary? */ " jnh 6f\n" "4: mvcs 0(%4,%1),0(%2),%3\n" "9: slgr %0,%4\n" " j 6f\n" "5: slgr %0,%0\n" "6: sacf 768\n" EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,6b) EX_TABLE(7b,3b) EX_TABLE(8b,3b) EX_TABLE(9b,6b) : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2) : : "cc", "memory"); return size; } unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n) { if (copy_with_mvcos()) return copy_to_user_mvcos(to, from, n); return copy_to_user_mvcs(to, from, n); } EXPORT_SYMBOL(raw_copy_to_user); static inline unsigned long copy_in_user_mvcos(void __user *to, const void __user *from, unsigned long size) { register unsigned long reg0 asm("0") = 0x810081UL; unsigned long tmp1, tmp2; tmp1 = -4096UL; /* FIXME: copy with reduced length. */ asm volatile( "0: .insn ss,0xc80000000000,0(%0,%1),0(%2),0\n" " jz 2f\n" "1: algr %0,%3\n" " slgr %1,%3\n" " slgr %2,%3\n" " j 0b\n" "2:slgr %0,%0\n" "3: \n" EX_TABLE(0b,3b) : "+a" (size), "+a" (to), "+a" (from), "+a" (tmp1), "=a" (tmp2) : "d" (reg0) : "cc", "memory"); return size; } static inline unsigned long copy_in_user_mvc(void __user *to, const void __user *from, unsigned long size) { unsigned long tmp1; asm volatile( " sacf 256\n" " aghi %0,-1\n" " jo 5f\n" " bras %3,3f\n" "0: aghi %0,257\n" "1: mvc 0(1,%1),0(%2)\n" " la %1,1(%1)\n" " la %2,1(%2)\n" " aghi %0,-1\n" " jnz 1b\n" " j 5f\n" "2: mvc 0(256,%1),0(%2)\n" " la %1,256(%1)\n" " la %2,256(%2)\n" "3: aghi %0,-256\n" " jnm 2b\n" "4: ex %0,1b-0b(%3)\n" "5: slgr %0,%0\n" "6: sacf 768\n" EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b) : "+a" (size), "+a" (to), "+a" (from), "=a" (tmp1) : : "cc", "memory"); return size; } unsigned long raw_copy_in_user(void __user *to, const void __user *from, unsigned long n) { if (copy_with_mvcos()) return copy_in_user_mvcos(to, from, n); return copy_in_user_mvc(to, from, n); } EXPORT_SYMBOL(raw_copy_in_user); static inline unsigned long clear_user_mvcos(void __user *to, unsigned long size) { register unsigned long reg0 asm("0") = 0x810000UL; unsigned long tmp1, tmp2; tmp1 = -4096UL; asm volatile( "0: .insn ss,0xc80000000000,0(%0,%1),0(%4),0\n" " jz 4f\n" "1: algr %0,%2\n" " slgr %1,%2\n" " j 0b\n" "2: la %3,4095(%1)\n"/* %4 = to + 4095 */ " nr %3,%2\n" /* %4 = (to + 4095) & -4096 */ " slgr %3,%1\n" " clgr %0,%3\n" /* copy crosses next page boundary? */ " jnh 5f\n" "3: .insn ss,0xc80000000000,0(%3,%1),0(%4),0\n" " slgr %0,%3\n" " j 5f\n" "4: slgr %0,%0\n" "5:\n" EX_TABLE(0b,2b) EX_TABLE(3b,5b) : "+a" (size), "+a" (to), "+a" (tmp1), "=a" (tmp2) : "a" (empty_zero_page), "d" (reg0) : "cc", "memory"); return size; } static inline unsigned long clear_user_xc(void __user *to, unsigned long size) { unsigned long tmp1, tmp2; asm volatile( " sacf 256\n" " aghi %0,-1\n" " jo 5f\n" " bras %3,3f\n" " xc 0(1,%1),0(%1)\n" "0: aghi %0,257\n" " la %2,255(%1)\n" /* %2 = ptr + 255 */ " srl %2,12\n" " sll %2,12\n" /* %2 = (ptr + 255) & -4096 */ " slgr %2,%1\n" " clgr %0,%2\n" /* clear crosses next page boundary? */ " jnh 5f\n" " aghi %2,-1\n" "1: ex %2,0(%3)\n" " aghi %2,1\n" " slgr %0,%2\n" " j 5f\n" "2: xc 0(256,%1),0(%1)\n" " la %1,256(%1)\n" "3: aghi %0,-256\n" " jnm 2b\n" "4: ex %0,0(%3)\n" "5: slgr %0,%0\n" "6: sacf 768\n" EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b) : "+a" (size), "+a" (to), "=a" (tmp1), "=a" (tmp2) : : "cc", "memory"); return size; } unsigned long __clear_user(void __user *to, unsigned long size) { if (copy_with_mvcos()) return clear_user_mvcos(to, size); return clear_user_xc(to, size); } EXPORT_SYMBOL(__clear_user); static inline unsigned long strnlen_user_srst(const char __user *src, unsigned long size) { register unsigned long reg0 asm("0") = 0; unsigned long tmp1, tmp2; asm volatile( " la %2,0(%1)\n" " la %3,0(%0,%1)\n" " slgr %0,%0\n" " sacf 256\n" "0: srst %3,%2\n" " jo 0b\n" " la %0,1(%3)\n" /* strnlen_user results includes \0 */ " slgr %0,%1\n" "1: sacf 768\n" EX_TABLE(0b,1b) : "+a" (size), "+a" (src), "=a" (tmp1), "=a" (tmp2) : "d" (reg0) : "cc", "memory"); return size; } unsigned long __strnlen_user(const char __user *src, unsigned long size) { if (unlikely(!size)) return 0; return strnlen_user_srst(src, size); } EXPORT_SYMBOL(__strnlen_user); long __strncpy_from_user(char *dst, const char __user *src, long size) { size_t done, len, offset, len_str; if (unlikely(size <= 0)) return 0; done = 0; do { offset = (size_t)src & (L1_CACHE_BYTES - 1); len = min(size - done, L1_CACHE_BYTES - offset); if (copy_from_user(dst, src, len)) return -EFAULT; len_str = strnlen(dst, len); done += len_str; src += len_str; dst += len_str; } while ((len_str == len) && (done < size)); return done; } EXPORT_SYMBOL(__strncpy_from_user); |