arch/um/sys-i386/ptrace.c

   1 /*
   2  * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
   3  * Licensed under the GPL
   4  */
   5
   6 #include "linux/sched.h"
   7 #include "asm/elf.h"
   8 #include "asm/ptrace.h"
   9 #include "asm/uaccess.h"
  10 #include "ptrace_user.h"
  11 #include "sysdep/sigcontext.h"
  12 #include "sysdep/sc.h"
  13
  14 void arch_switch(void)
  15 {
  16         update_debugregs(current->thread.arch.debugregs_seq);
  17 }
  18
  19 int is_syscall(unsigned long addr)
  20 {
  21         unsigned short instr;
  22         int n;
  23
  24         n = copy_from_user(&instr, (void *) addr, sizeof(instr));
  25         if(n){
  26                 printk("is_syscall : failed to read instruction from 0x%lu\n",
  27                        addr);
  28                 return(0);
  29         }
  30         return(instr == 0x80cd);
  31 }
  32
  33 /* determines which flags the user has access to. */
  34 /* 1 = access 0 = no access */
  35 #define FLAG_MASK 0x00044dd5
  36
  37 int putreg(struct task_struct *child, int regno, unsigned long value)
  38 {
  39         regno >>= 2;
  40         switch (regno) {
  41         case FS:
  42                 if (value && (value & 3) != 3)
  43                         return -EIO;
  44                 PT_REGS_FS(&child->thread.regs) = value;
  45                 return 0;
  46         case GS:
  47                 if (value && (value & 3) != 3)
  48                         return -EIO;
  49                 PT_REGS_GS(&child->thread.regs) = value;
  50                 return 0;
  51         case DS:
  52         case ES:
  53                 if (value && (value & 3) != 3)
  54                         return -EIO;
  55                 value &= 0xffff;
  56                 break;
  57         case SS:
  58         case CS:
  59                 if ((value & 3) != 3)
  60                         return -EIO;
  61                 value &= 0xffff;
  62                 break;
  63         case EFL:
  64                 value &= FLAG_MASK;
  65                 value |= PT_REGS_EFLAGS(&child->thread.regs);
  66                 break;
  67         }
  68         PT_REGS_SET(&child->thread.regs, regno, value);
  69         return 0;
  70 }
  71
  72 unsigned long getreg(struct task_struct *child, int regno)
  73 {
  74         unsigned long retval = ~0UL;
  75
  76         regno >>= 2;
  77         switch (regno) {
  78         case FS:
  79         case GS:
  80         case DS:
  81         case ES:
  82         case SS:
  83         case CS:
  84                 retval = 0xffff;
  85                 /* fall through */
  86         default:
  87                 retval &= PT_REG(&child->thread.regs, regno);
  88         }
  89         return retval;
  90 }
  91
  92 struct i387_fxsave_struct {
  93         unsigned short  cwd;
  94         unsigned short  swd;
  95         unsigned short  twd;
  96         unsigned short  fop;
  97         long    fip;
  98         long    fcs;
  99         long    foo;
 100         long    fos;
 101         long    mxcsr;
 102         long    reserved;
 103         long    st_space[32];   /* 8*16 bytes for each FP-reg = 128 bytes */
 104         long    xmm_space[32];  /* 8*16 bytes for each XMM-reg = 128 bytes */
 105         long    padding[56];
 106 };
 107
 108 /*
 109  * FPU tag word conversions.
 110  */
 111
 112 static inline unsigned short twd_i387_to_fxsr( unsigned short twd )
 113 {
 114         unsigned int tmp; /* to avoid 16 bit prefixes in the code */
 115
 116         /* Transform each pair of bits into 01 (valid) or 00 (empty) */
 117         tmp = ~twd;
 118         tmp = (tmp | (tmp>>1)) & 0x5555; /* 0V0V0V0V0V0V0V0V */
 119         /* and move the valid bits to the lower byte. */
 120         tmp = (tmp | (tmp >> 1)) & 0x3333; /* 00VV00VV00VV00VV */
 121         tmp = (tmp | (tmp >> 2)) & 0x0f0f; /* 0000VVVV0000VVVV */
 122         tmp = (tmp | (tmp >> 4)) & 0x00ff; /* 00000000VVVVVVVV */
 123         return tmp;
 124 }
 125
 126 static inline unsigned long twd_fxsr_to_i387( struct i387_fxsave_struct *fxsave )
 127 {
 128         struct _fpxreg *st = NULL;
 129         unsigned long twd = (unsigned long) fxsave->twd;
 130         unsigned long tag;
 131         unsigned long ret = 0xffff0000;
 132         int i;
 133
 134 #define FPREG_ADDR(f, n)        ((char *)&(f)->st_space + (n) * 16);
 135
 136         for ( i = 0 ; i < 8 ; i++ ) {
 137                 if ( twd & 0x1 ) {
 138                         st = (struct _fpxreg *) FPREG_ADDR( fxsave, i );
 139
 140                         switch ( st->exponent & 0x7fff ) {
 141                         case 0x7fff:
 142                                 tag = 2;                /* Special */
 143                                 break;
 144                         case 0x0000:
 145                                 if ( !st->significand[0] &&
 146                                      !st->significand[1] &&
 147                                      !st->significand[2] &&
 148                                      !st->significand[3] ) {
 149                                         tag = 1;        /* Zero */
 150                                 } else {
 151                                         tag = 2;        /* Special */
 152                                 }
 153                                 break;
 154                         default:
 155                                 if ( st->significand[3] & 0x8000 ) {
 156                                         tag = 0;        /* Valid */
 157                                 } else {
 158                                         tag = 2;        /* Special */
 159                                 }
 160                                 break;
 161                         }
 162                 } else {
 163                         tag = 3;                        /* Empty */
 164                 }
 165                 ret |= (tag << (2 * i));
 166                 twd = twd >> 1;
 167         }
 168         return ret;
 169 }
 170
 171 /*
 172  * FXSR floating point environment conversions.
 173  */
 174
 175 #ifdef CONFIG_MODE_TT
 176 static inline int convert_fxsr_to_user_tt(struct _fpstate *buf,
 177                                           struct pt_regs *regs)
 178 {
 179         struct i387_fxsave_struct *fxsave = SC_FXSR_ENV(PT_REGS_SC(regs));
 180         unsigned long env[7];
 181         struct _fpreg *to;
 182         struct _fpxreg *from;
 183         int i;
 184
 185         env[0] = (unsigned long)fxsave->cwd | 0xffff0000;
 186         env[1] = (unsigned long)fxsave->swd | 0xffff0000;
 187         env[2] = twd_fxsr_to_i387(fxsave);
 188         env[3] = fxsave->fip;
 189         env[4] = fxsave->fcs | ((unsigned long)fxsave->fop << 16);
 190         env[5] = fxsave->foo;
 191         env[6] = fxsave->fos;
 192
 193         if ( __copy_to_user( buf, env, 7 * sizeof(unsigned long) ) )
 194                 return 1;
 195
 196         to = &buf->_st[0];
 197         from = (struct _fpxreg *) &fxsave->st_space[0];
 198         for ( i = 0 ; i < 8 ; i++, to++, from++ ) {
 199                 if ( __copy_to_user( to, from, sizeof(*to) ) )
 200                         return 1;
 201         }
 202         return 0;
 203 }
 204 #endif
 205
 206 static inline int convert_fxsr_to_user(struct _fpstate *buf,
 207                                        struct pt_regs *regs)
 208 {
 209         return(CHOOSE_MODE(convert_fxsr_to_user_tt(buf, regs), 0));
 210 }
 211
 212 #ifdef CONFIG_MODE_TT
 213 static inline int convert_fxsr_from_user_tt(struct pt_regs *regs,
 214                                             struct _fpstate *buf)
 215 {
 216         struct i387_fxsave_struct *fxsave = SC_FXSR_ENV(PT_REGS_SC(regs));
 217         unsigned long env[7];
 218         struct _fpxreg *to;
 219         struct _fpreg *from;
 220         int i;
 221
 222         if ( __copy_from_user( env, buf, 7 * sizeof(long) ) )
 223                 return 1;
 224
 225         fxsave->cwd = (unsigned short)(env[0] & 0xffff);
 226         fxsave->swd = (unsigned short)(env[1] & 0xffff);
 227         fxsave->twd = twd_i387_to_fxsr((unsigned short)(env[2] & 0xffff));
 228         fxsave->fip = env[3];
 229         fxsave->fop = (unsigned short)((env[4] & 0xffff0000) >> 16);
 230         fxsave->fcs = (env[4] & 0xffff);
 231         fxsave->foo = env[5];
 232         fxsave->fos = env[6];
 233
 234         to = (struct _fpxreg *) &fxsave->st_space[0];
 235         from = &buf->_st[0];
 236         for ( i = 0 ; i < 8 ; i++, to++, from++ ) {
 237                 if ( __copy_from_user( to, from, sizeof(*from) ) )
 238                         return 1;
 239         }
 240         return 0;
 241 }
 242 #endif
 243
 244 static inline int convert_fxsr_from_user(struct pt_regs *regs,
 245                                          struct _fpstate *buf)
 246 {
 247         return(CHOOSE_MODE(convert_fxsr_from_user_tt(regs, buf), 0));
 248 }
 249
 250 int get_fpregs(unsigned long buf, struct task_struct *child)
 251 {
 252         int err;
 253
 254         err = convert_fxsr_to_user((struct _fpstate *) buf,
 255                                    &child->thread.regs);
 256         if(err) return(-EFAULT);
 257         else return(0);
 258 }
 259
 260 int set_fpregs(unsigned long buf, struct task_struct *child)
 261 {
 262         int err;
 263
 264         err = convert_fxsr_from_user(&child->thread.regs,
 265                                      (struct _fpstate *) buf);
 266         if(err) return(-EFAULT);
 267         else return(0);
 268 }
 269
 270 #ifdef CONFIG_MODE_TT
 271 int get_fpxregs_tt(unsigned long buf, struct task_struct *tsk)
 272 {
 273         struct pt_regs *regs = &tsk->thread.regs;
 274         struct i387_fxsave_struct *fxsave = SC_FXSR_ENV(PT_REGS_SC(regs));
 275         int err;
 276
 277         err = __copy_to_user((void *) buf, fxsave,
 278                              sizeof(struct user_fxsr_struct));
 279         if(err) return -EFAULT;
 280         else return 0;
 281 }
 282 #endif
 283
 284 int get_fpxregs(unsigned long buf, struct task_struct *tsk)
 285 {
 286         return(CHOOSE_MODE(get_fpxregs_tt(buf, tsk), 0));
 287 }
 288
 289 #ifdef CONFIG_MODE_TT
 290 int set_fpxregs_tt(unsigned long buf, struct task_struct *tsk)
 291 {
 292         struct pt_regs *regs = &tsk->thread.regs;
 293         struct i387_fxsave_struct *fxsave = SC_FXSR_ENV(PT_REGS_SC(regs));
 294         int err;
 295
 296         err = __copy_from_user(fxsave, (void *) buf,
 297                                sizeof(struct user_fxsr_struct) );
 298         if(err) return -EFAULT;
 299         else return 0;
 300 }
 301 #endif
 302
 303 int set_fpxregs(unsigned long buf, struct task_struct *tsk)
 304 {
 305         return(CHOOSE_MODE(set_fpxregs_tt(buf, tsk), 0));
 306 }
 307
 308 #ifdef notdef
 309 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
 310 {
 311         fpu->cwd = (((SC_FP_CW(PT_REGS_SC(regs)) & 0xffff) << 16) |
 312                     (SC_FP_SW(PT_REGS_SC(regs)) & 0xffff));
 313         fpu->swd = SC_FP_CSSEL(PT_REGS_SC(regs)) & 0xffff;
 314         fpu->twd = SC_FP_IPOFF(PT_REGS_SC(regs));
 315         fpu->fip = SC_FP_CSSEL(PT_REGS_SC(regs)) & 0xffff;
 316         fpu->fcs = SC_FP_DATAOFF(PT_REGS_SC(regs));
 317         fpu->foo = SC_FP_DATASEL(PT_REGS_SC(regs));
 318         fpu->fos = 0;
 319         memcpy(fpu->st_space, (void *) SC_FP_ST(PT_REGS_SC(regs)),
 320                sizeof(fpu->st_space));
 321         return(1);
 322 }
 323 #endif
 324
 325 #ifdef CONFIG_MODE_TT
 326 static inline void copy_fpu_fxsave_tt(struct pt_regs *regs,
 327                                       struct user_i387_struct *buf)
 328 {
 329         struct i387_fxsave_struct *fpu = SC_FXSR_ENV(PT_REGS_SC(regs));
 330         unsigned short *to;
 331         unsigned short *from;
 332         int i;
 333
 334         memcpy( buf, fpu, 7 * sizeof(long) );
 335
 336         to = (unsigned short *) &buf->st_space[0];
 337         from = (unsigned short *) &fpu->st_space[0];
 338         for ( i = 0 ; i < 8 ; i++, to += 5, from += 8 ) {
 339                 memcpy( to, from, 5 * sizeof(unsigned short) );
 340         }
 341 }
 342 #endif
 343
 344 static inline void copy_fpu_fxsave(struct pt_regs *regs,
 345                                    struct user_i387_struct *buf)
 346 {
 347         (void) CHOOSE_MODE(copy_fpu_fxsave_tt(regs, buf), 0);
 348 }
 349
 350 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu )
 351 {
 352         copy_fpu_fxsave(regs, (struct user_i387_struct *) fpu);
 353         return(1);
 354 }
 355
 356 /*
 357  * Overrides for Emacs so that we follow Linus's tabbing style.
 358  * Emacs will notice this stuff at the end of the file and automatically
 359  * adjust the settings for this buffer only.  This must remain at the end
 360  * of the file.
 361  * ---------------------------------------------------------------------------
 362  * Local variables:
 363  * c-file-style: "linux"
 364  * End:
 365  */