linux/arch/s390/lib/uaccess_std.c
<<
>>
Prefs
   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                "0: cs   %1,%4,0(%5)\n"
 297                "1: lr   %0,%1\n"
 298                "2: sacf 0\n"
 299                EX_TABLE(0b,2b) EX_TABLE(1b,2b)
 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