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 " 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 " 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 " "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 : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2) 69 : : "cc", "memory"); 70 return size; 71} 72 73static size_t copy_from_user_std_check(size_t size, const void __user *ptr, 74 void *x) 75{ 76 if (size <= 1024) 77 return copy_from_user_std(size, ptr, x); 78 return copy_from_user_pt(size, ptr, x); 79} 80 81size_t copy_to_user_std(size_t size, void __user *ptr, const void *x) 82{ 83 unsigned long tmp1, tmp2; 84 85 tmp1 = -256UL; 86 asm volatile( 87 "0: mvcs 0(%0,%1),0(%2),%3\n" 88 " jz 5f\n" 89 "1:"ALR" %0,%3\n" 90 " la %1,256(%1)\n" 91 " la %2,256(%2)\n" 92 "2: mvcs 0(%0,%1),0(%2),%3\n" 93 " jnz 1b\n" 94 " j 5f\n" 95 "3: la %4,255(%1)\n" /* %4 = ptr + 255 */ 96 " "LHI" %3,-4096\n" 97 " nr %4,%3\n" /* %4 = (ptr + 255) & -4096 */ 98 " "SLR" %4,%1\n" 99 " "CLR" %0,%4\n" /* copy crosses next page boundary? */ 100 " jnh 6f\n" 101 "4: mvcs 0(%4,%1),0(%2),%3\n" 102 " "SLR" %0,%4\n" 103 " j 6f\n" 104 "5:"SLR" %0,%0\n" 105 "6: \n" 106 EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,6b) 107 : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2) 108 : : "cc", "memory"); 109 return size; 110} 111 112static size_t copy_to_user_std_check(size_t size, void __user *ptr, 113 const void *x) 114{ 115 if (size <= 1024) 116 return copy_to_user_std(size, ptr, x); 117 return copy_to_user_pt(size, ptr, x); 118} 119 120static size_t copy_in_user_std(size_t size, void __user *to, 121 const void __user *from) 122{ 123 unsigned long tmp1; 124 125 asm volatile( 126 " "AHI" %0,-1\n" 127 " jo 5f\n" 128 " sacf 256\n" 129 " bras %3,3f\n" 130 "0:"AHI" %0,257\n" 131 "1: mvc 0(1,%1),0(%2)\n" 132 " la %1,1(%1)\n" 133 " la %2,1(%2)\n" 134 " "AHI" %0,-1\n" 135 " jnz 1b\n" 136 " j 5f\n" 137 "2: mvc 0(256,%1),0(%2)\n" 138 " la %1,256(%1)\n" 139 " la %2,256(%2)\n" 140 "3:"AHI" %0,-256\n" 141 " jnm 2b\n" 142 "4: ex %0,1b-0b(%3)\n" 143 " sacf 0\n" 144 "5: "SLR" %0,%0\n" 145 "6:\n" 146 EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b) 147 : "+a" (size), "+a" (to), "+a" (from), "=a" (tmp1) 148 : : "cc", "memory"); 149 return size; 150} 151 152static size_t clear_user_std(size_t size, void __user *to) 153{ 154 unsigned long tmp1, tmp2; 155 156 asm volatile( 157 " "AHI" %0,-1\n" 158 " jo 5f\n" 159 " sacf 256\n" 160 " bras %3,3f\n" 161 " xc 0(1,%1),0(%1)\n" 162 "0:"AHI" %0,257\n" 163 " la %2,255(%1)\n" /* %2 = ptr + 255 */ 164 " srl %2,12\n" 165 " sll %2,12\n" /* %2 = (ptr + 255) & -4096 */ 166 " "SLR" %2,%1\n" 167 " "CLR" %0,%2\n" /* clear crosses next page boundary? */ 168 " jnh 5f\n" 169 " "AHI" %2,-1\n" 170 "1: ex %2,0(%3)\n" 171 " "AHI" %2,1\n" 172 " "SLR" %0,%2\n" 173 " j 5f\n" 174 "2: xc 0(256,%1),0(%1)\n" 175 " la %1,256(%1)\n" 176 "3:"AHI" %0,-256\n" 177 " jnm 2b\n" 178 "4: ex %0,0(%3)\n" 179 " sacf 0\n" 180 "5: "SLR" %0,%0\n" 181 "6:\n" 182 EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b) 183 : "+a" (size), "+a" (to), "=a" (tmp1), "=a" (tmp2) 184 : : "cc", "memory"); 185 return size; 186} 187 188size_t strnlen_user_std(size_t size, const char __user *src) 189{ 190 register unsigned long reg0 asm("0") = 0UL; 191 unsigned long tmp1, tmp2; 192 193 asm volatile( 194 " la %2,0(%1)\n" 195 " la %3,0(%0,%1)\n" 196 " "SLR" %0,%0\n" 197 " sacf 256\n" 198 "0: srst %3,%2\n" 199 " jo 0b\n" 200 " la %0,1(%3)\n" /* strnlen_user results includes \0 */ 201 " "SLR" %0,%1\n" 202 "1: sacf 0\n" 203 EX_TABLE(0b,1b) 204 : "+a" (size), "+a" (src), "=a" (tmp1), "=a" (tmp2) 205 : "d" (reg0) : "cc", "memory"); 206 return size; 207} 208 209size_t strncpy_from_user_std(size_t size, const char __user *src, char *dst) 210{ 211 register unsigned long reg0 asm("0") = 0UL; 212 unsigned long tmp1, tmp2; 213 214 asm volatile( 215 " la %3,0(%1)\n" 216 " la %4,0(%0,%1)\n" 217 " sacf 256\n" 218 "0: srst %4,%3\n" 219 " jo 0b\n" 220 " sacf 0\n" 221 " la %0,0(%4)\n" 222 " jh 1f\n" /* found \0 in string ? */ 223 " "AHI" %4,1\n" /* include \0 in copy */ 224 "1:"SLR" %0,%1\n" /* %0 = return length (without \0) */ 225 " "SLR" %4,%1\n" /* %4 = copy length (including \0) */ 226 "2: mvcp 0(%4,%2),0(%1),%5\n" 227 " jz 9f\n" 228 "3:"AHI" %4,-256\n" 229 " la %1,256(%1)\n" 230 " la %2,256(%2)\n" 231 "4: mvcp 0(%4,%2),0(%1),%5\n" 232 " jnz 3b\n" 233 " j 9f\n" 234 "7: sacf 0\n" 235 "8:"LHI" %0,%6\n" 236 "9:\n" 237 EX_TABLE(0b,7b) EX_TABLE(2b,8b) EX_TABLE(4b,8b) 238 : "+a" (size), "+a" (src), "+d" (dst), "=a" (tmp1), "=a" (tmp2) 239 : "d" (reg0), "K" (-EFAULT) : "cc", "memory"); 240 return size; 241} 242 243#define __futex_atomic_op(insn, ret, oldval, newval, uaddr, oparg) \ 244 asm volatile( \ 245 " sacf 256\n" \ 246 "0: l %1,0(%6)\n" \ 247 "1:"insn \ 248 "2: cs %1,%2,0(%6)\n" \ 249 "3: jl 1b\n" \ 250 " lhi %0,0\n" \ 251 "4: sacf 0\n" \ 252 EX_TABLE(0b,4b) EX_TABLE(2b,4b) EX_TABLE(3b,4b) \ 253 : "=d" (ret), "=&d" (oldval), "=&d" (newval), \ 254 "=m" (*uaddr) \ 255 : "0" (-EFAULT), "d" (oparg), "a" (uaddr), \ 256 "m" (*uaddr) : "cc"); 257 258int futex_atomic_op_std(int op, int __user *uaddr, int oparg, int *old) 259{ 260 int oldval = 0, newval, ret; 261 262 switch (op) { 263 case FUTEX_OP_SET: 264 __futex_atomic_op("lr %2,%5\n", 265 ret, oldval, newval, uaddr, oparg); 266 break; 267 case FUTEX_OP_ADD: 268 __futex_atomic_op("lr %2,%1\nar %2,%5\n", 269 ret, oldval, newval, uaddr, oparg); 270 break; 271 case FUTEX_OP_OR: 272 __futex_atomic_op("lr %2,%1\nor %2,%5\n", 273 ret, oldval, newval, uaddr, oparg); 274 break; 275 case FUTEX_OP_ANDN: 276 __futex_atomic_op("lr %2,%1\nnr %2,%5\n", 277 ret, oldval, newval, uaddr, oparg); 278 break; 279 case FUTEX_OP_XOR: 280 __futex_atomic_op("lr %2,%1\nxr %2,%5\n", 281 ret, oldval, newval, uaddr, oparg); 282 break; 283 default: 284 ret = -ENOSYS; 285 } 286 *old = oldval; 287 return ret; 288} 289 290int futex_atomic_cmpxchg_std(int __user *uaddr, int oldval, int newval) 291{ 292 int ret; 293 294 asm volatile( 295 " sacf 256\n" 296 " cs %1,%4,0(%5)\n" 297 "0: lr %0,%1\n" 298 "1: sacf 0\n" 299 EX_TABLE(0b,1b) 300 : "=d" (ret), "+d" (oldval), "=m" (*uaddr) 301 : "0" (-EFAULT), "d" (newval), "a" (uaddr), "m" (*uaddr) 302 : "cc", "memory" ); 303 return ret; 304} 305 306struct uaccess_ops uaccess_std = { 307 .copy_from_user = copy_from_user_std_check, 308 .copy_from_user_small = copy_from_user_std, 309 .copy_to_user = copy_to_user_std_check, 310 .copy_to_user_small = copy_to_user_std, 311 .copy_in_user = copy_in_user_std, 312 .clear_user = clear_user_std, 313 .strnlen_user = strnlen_user_std, 314 .strncpy_from_user = strncpy_from_user_std, 315 .futex_atomic_op = futex_atomic_op_std, 316 .futex_atomic_cmpxchg = futex_atomic_cmpxchg_std, 317}; 318