1/* 2 * arch/s390/lib/uaccess_std.c 3 * 4 * Standard user space access functions based on mvcp/mvcs and doing 5 * interesting things in the secondary space mode. 6 * 7 * Copyright (C) IBM Corp. 2006 8 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com), 9 * Gerald Schaefer (gerald.schaefer@de.ibm.com) 10 */ 11 12#include <linux/errno.h> 13#include <linux/mm.h> 14#include <linux/uaccess.h> 15#include <asm/futex.h> 16#include "uaccess.h" 17 18#ifndef __s390x__ 19#define AHI "ahi" 20#define ALR "alr" 21#define CLR "clr" 22#define LHI "lhi" 23#define SLR "slr" 24#else 25#define AHI "aghi" 26#define ALR "algr" 27#define CLR "clgr" 28#define LHI "lghi" 29#define SLR "slgr" 30#endif 31 32size_t copy_from_user_std(size_t size, const void __user *ptr, void *x) 33{ 34 unsigned long tmp1, tmp2; 35 36 tmp1 = -256UL; 37 asm volatile( 38 "0: mvcp 0(%0,%2),0(%1),%3\n" 39 "10:jz 8f\n" 40 "1:"ALR" %0,%3\n" 41 " la %1,256(%1)\n" 42 " la %2,256(%2)\n" 43 "2: mvcp 0(%0,%2),0(%1),%3\n" 44 "11:jnz 1b\n" 45 " j 8f\n" 46 "3: la %4,255(%1)\n" /* %4 = ptr + 255 */ 47 " "LHI" %3,-4096\n" 48 " nr %4,%3\n" /* %4 = (ptr + 255) & -4096 */ 49 " "SLR" %4,%1\n" 50 " "CLR" %0,%4\n" /* copy crosses next page boundary? */ 51 " jnh 5f\n" 52 "4: mvcp 0(%4,%2),0(%1),%3\n" 53 "12:"SLR" %0,%4\n" 54 " "ALR" %2,%4\n" 55 "5:"LHI" %4,-1\n" 56 " "ALR" %4,%0\n" /* copy remaining size, subtract 1 */ 57 " bras %3,7f\n" /* memset loop */ 58 " xc 0(1,%2),0(%2)\n" 59 "6: xc 0(256,%2),0(%2)\n" 60 " la %2,256(%2)\n" 61 "7:"AHI" %4,-256\n" 62 " jnm 6b\n" 63 " ex %4,0(%3)\n" 64 " j 9f\n" 65 "8:"SLR" %0,%0\n" 66 "9: \n" 67 EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,5b) 68 EX_TABLE(10b,3b) EX_TABLE(11b,3b) EX_TABLE(12b,5b) 69 : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2) 70 : : "cc", "memory"); 71 return size; 72} 73 74static size_t copy_from_user_std_check(size_t size, const void __user *ptr, 75 void *x) 76{ 77 if (size <= 1024) 78 return copy_from_user_std(size, ptr, x); 79 return copy_from_user_pt(size, ptr, x); 80} 81 82size_t copy_to_user_std(size_t size, void __user *ptr, const void *x) 83{ 84 unsigned long tmp1, tmp2; 85 86 tmp1 = -256UL; 87 asm volatile( 88 "0: mvcs 0(%0,%1),0(%2),%3\n" 89 "7: jz 5f\n" 90 "1:"ALR" %0,%3\n" 91 " la %1,256(%1)\n" 92 " la %2,256(%2)\n" 93 "2: mvcs 0(%0,%1),0(%2),%3\n" 94 "8: jnz 1b\n" 95 " j 5f\n" 96 "3: la %4,255(%1)\n" /* %4 = ptr + 255 */ 97 " "LHI" %3,-4096\n" 98 " nr %4,%3\n" /* %4 = (ptr + 255) & -4096 */ 99 " "SLR" %4,%1\n" 100 " "CLR" %0,%4\n" /* copy crosses next page boundary? */ 101 " jnh 6f\n" 102 "4: mvcs 0(%4,%1),0(%2),%3\n" 103 "9:"SLR" %0,%4\n" 104 " j 6f\n" 105 "5:"SLR" %0,%0\n" 106 "6: \n" 107 EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,6b) 108 EX_TABLE(7b,3b) EX_TABLE(8b,3b) EX_TABLE(9b,6b) 109 : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2) 110 : : "cc", "memory"); 111 return size; 112} 113 114static size_t copy_to_user_std_check(size_t size, void __user *ptr, 115 const void *x) 116{ 117 if (size <= 1024) 118 return copy_to_user_std(size, ptr, x); 119 return copy_to_user_pt(size, ptr, x); 120} 121 122static size_t copy_in_user_std(size_t size, void __user *to, 123 const void __user *from) 124{ 125 unsigned long tmp1; 126 127 asm volatile( 128 " "AHI" %0,-1\n" 129 " jo 5f\n" 130 " sacf 256\n" 131 " bras %3,3f\n" 132 "0:"AHI" %0,257\n" 133 "1: mvc 0(1,%1),0(%2)\n" 134 " la %1,1(%1)\n" 135 " la %2,1(%2)\n" 136 " "AHI" %0,-1\n" 137 " jnz 1b\n" 138 " j 5f\n" 139 "2: mvc 0(256,%1),0(%2)\n" 140 " la %1,256(%1)\n" 141 " la %2,256(%2)\n" 142 "3:"AHI" %0,-256\n" 143 " jnm 2b\n" 144 "4: ex %0,1b-0b(%3)\n" 145 " sacf 0\n" 146 "5: "SLR" %0,%0\n" 147 "6:\n" 148 EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b) 149 : "+a" (size), "+a" (to), "+a" (from), "=a" (tmp1) 150 : : "cc", "memory"); 151 return size; 152} 153 154static size_t clear_user_std(size_t size, void __user *to) 155{ 156 unsigned long tmp1, tmp2; 157 158 asm volatile( 159 " "AHI" %0,-1\n" 160 " jo 5f\n" 161 " sacf 256\n" 162 " bras %3,3f\n" 163 " xc 0(1,%1),0(%1)\n" 164 "0:"AHI" %0,257\n" 165 " la %2,255(%1)\n" /* %2 = ptr + 255 */ 166 " srl %2,12\n" 167 " sll %2,12\n" /* %2 = (ptr + 255) & -4096 */ 168 " "SLR" %2,%1\n" 169 " "CLR" %0,%2\n" /* clear crosses next page boundary? */ 170 " jnh 5f\n" 171 " "AHI" %2,-1\n" 172 "1: ex %2,0(%3)\n" 173 " "AHI" %2,1\n" 174 " "SLR" %0,%2\n" 175 " j 5f\n" 176 "2: xc 0(256,%1),0(%1)\n" 177 " la %1,256(%1)\n" 178 "3:"AHI" %0,-256\n" 179 " jnm 2b\n" 180 "4: ex %0,0(%3)\n" 181 " sacf 0\n" 182 "5: "SLR" %0,%0\n" 183 "6:\n" 184 EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b) 185 : "+a" (size), "+a" (to), "=a" (tmp1), "=a" (tmp2) 186 : : "cc", "memory"); 187 return size; 188} 189 190size_t strnlen_user_std(size_t size, const char __user *src) 191{ 192 register unsigned long reg0 asm("0") = 0UL; 193 unsigned long tmp1, tmp2; 194 195 asm volatile( 196 " la %2,0(%1)\n" 197 " la %3,0(%0,%1)\n" 198 " "SLR" %0,%0\n" 199 " sacf 256\n" 200 "0: srst %3,%2\n" 201 " jo 0b\n" 202 " la %0,1(%3)\n" /* strnlen_user results includes \0 */ 203 " "SLR" %0,%1\n" 204 "1: sacf 0\n" 205 EX_TABLE(0b,1b) 206 : "+a" (size), "+a" (src), "=a" (tmp1), "=a" (tmp2) 207 : "d" (reg0) : "cc", "memory"); 208 return size; 209} 210 211size_t strncpy_from_user_std(size_t size, const char __user *src, char *dst) 212{ 213 register unsigned long reg0 asm("0") = 0UL; 214 unsigned long tmp1, tmp2; 215 216 asm volatile( 217 " la %3,0(%1)\n" 218 " la %4,0(%0,%1)\n" 219 " sacf 256\n" 220 "0: srst %4,%3\n" 221 " jo 0b\n" 222 " sacf 0\n" 223 " la %0,0(%4)\n" 224 " jh 1f\n" /* found \0 in string ? */ 225 " "AHI" %4,1\n" /* include \0 in copy */ 226 "1:"SLR" %0,%1\n" /* %0 = return length (without \0) */ 227 " "SLR" %4,%1\n" /* %4 = copy length (including \0) */ 228 "2: mvcp 0(%4,%2),0(%1),%5\n" 229 " jz 9f\n" 230 "3:"AHI" %4,-256\n" 231 " la %1,256(%1)\n" 232 " la %2,256(%2)\n" 233 "4: mvcp 0(%4,%2),0(%1),%5\n" 234 " jnz 3b\n" 235 " j 9f\n" 236 "7: sacf 0\n" 237 "8:"LHI" %0,%6\n" 238 "9:\n" 239 EX_TABLE(0b,7b) EX_TABLE(2b,8b) EX_TABLE(4b,8b) 240 : "+a" (size), "+a" (src), "+d" (dst), "=a" (tmp1), "=a" (tmp2) 241 : "d" (reg0), "K" (-EFAULT) : "cc", "memory"); 242 return size; 243} 244 245#define __futex_atomic_op(insn, ret, oldval, newval, uaddr, oparg) \ 246 asm volatile( \ 247 " sacf 256\n" \ 248 "0: l %1,0(%6)\n" \ 249 "1:"insn \ 250 "2: cs %1,%2,0(%6)\n" \ 251 "3: jl 1b\n" \ 252 " lhi %0,0\n" \ 253 "4: sacf 0\n" \ 254 EX_TABLE(0b,4b) EX_TABLE(2b,4b) EX_TABLE(3b,4b) \ 255 : "=d" (ret), "=&d" (oldval), "=&d" (newval), \ 256 "=m" (*uaddr) \ 257 : "0" (-EFAULT), "d" (oparg), "a" (uaddr), \ 258 "m" (*uaddr) : "cc"); 259 260int futex_atomic_op_std(int op, int __user *uaddr, int oparg, int *old) 261{ 262 int oldval = 0, newval, ret; 263 264 switch (op) { 265 case FUTEX_OP_SET: 266 __futex_atomic_op("lr %2,%5\n", 267 ret, oldval, newval, uaddr, oparg); 268 break; 269 case FUTEX_OP_ADD: 270 __futex_atomic_op("lr %2,%1\nar %2,%5\n", 271 ret, oldval, newval, uaddr, oparg); 272 break; 273 case FUTEX_OP_OR: 274 __futex_atomic_op("lr %2,%1\nor %2,%5\n", 275 ret, oldval, newval, uaddr, oparg); 276 break; 277 case FUTEX_OP_ANDN: 278 __futex_atomic_op("lr %2,%1\nnr %2,%5\n", 279 ret, oldval, newval, uaddr, oparg); 280 break; 281 case FUTEX_OP_XOR: 282 __futex_atomic_op("lr %2,%1\nxr %2,%5\n", 283 ret, oldval, newval, uaddr, oparg); 284 break; 285 default: 286 ret = -ENOSYS; 287 } 288 *old = oldval; 289 return ret; 290} 291 292int futex_atomic_cmpxchg_std(int __user *uaddr, int oldval, int newval) 293{ 294 int ret; 295 296 asm volatile( 297 " sacf 256\n" 298 "0: cs %1,%4,0(%5)\n" 299 "1: lr %0,%1\n" 300 "2: sacf 0\n" 301 EX_TABLE(0b,2b) EX_TABLE(1b,2b) 302 : "=d" (ret), "+d" (oldval), "=m" (*uaddr) 303 : "0" (-EFAULT), "d" (newval), "a" (uaddr), "m" (*uaddr) 304 : "cc", "memory" ); 305 return ret; 306} 307 308struct uaccess_ops uaccess_std = { 309 .copy_from_user = copy_from_user_std_check, 310 .copy_from_user_small = copy_from_user_std, 311 .copy_to_user = copy_to_user_std_check, 312 .copy_to_user_small = copy_to_user_std, 313 .copy_in_user = copy_in_user_std, 314 .clear_user = clear_user_std, 315 .strnlen_user = strnlen_user_std, 316 .strncpy_from_user = strncpy_from_user_std, 317 .futex_atomic_op = futex_atomic_op_std, 318 .futex_atomic_cmpxchg = futex_atomic_cmpxchg_std, 319}; 320