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/config.h>
   7 #include <linux/compiler.h>
   8 #include "linux/sched.h"
   9 #include "asm/elf.h"
  10 #include "asm/ptrace.h"
  11 #include "asm/uaccess.h"
  12 #include "asm/unistd.h"
  13 #include "sysdep/ptrace.h"
  14 #include "sysdep/sigcontext.h"
  15 #include "sysdep/sc.h"
  16
  17 void arch_switch(void)
  18 {
  19         update_debugregs(current->thread.arch.debugregs_seq);
  20 }
  21
  22 int is_syscall(unsigned long addr)
  23 {
  24         unsigned short instr;
  25         int n;
  26
  27         n = copy_from_user(&instr, (void __user *) addr, sizeof(instr));
  28         if(n){
  29                 printk("is_syscall : failed to read instruction from 0x%lx\n",
  30                        addr);
  31                 return(0);
  32         }
  33         /* int 0x80 or sysenter */
  34         return((instr == 0x80cd) || (instr == 0x340f));
  35 }
  36
  37 /* determines which flags the user has access to. */
  38 /* 1 = access 0 = no access */
  39 #define FLAG_MASK 0x00044dd5
  40
  41 int putreg(struct task_struct *child, int regno, unsigned long value)
  42 {
  43         regno >>= 2;
  44         switch (regno) {
  45         case FS:
  46                 if (value && (value & 3) != 3)
  47                         return -EIO;
  48                 PT_REGS_FS(&child->thread.regs) = value;
  49                 return 0;
  50         case GS:
  51                 if (value && (value & 3) != 3)
  52                         return -EIO;
  53                 PT_REGS_GS(&child->thread.regs) = value;
  54                 return 0;
  55         case DS:
  56         case ES:
  57                 if (value && (value & 3) != 3)
  58                         return -EIO;
  59                 value &= 0xffff;
  60                 break;
  61         case SS:
  62         case CS:
  63                 if ((value & 3) != 3)
  64                         return -EIO;
  65                 value &= 0xffff;
  66                 break;
  67         case EFL:
  68                 value &= FLAG_MASK;
  69                 value |= PT_REGS_EFLAGS(&child->thread.regs);
  70                 break;
  71         }
  72         PT_REGS_SET(&child->thread.regs, regno, value);
  73         return 0;
  74 }
  75
  76 int poke_user(struct task_struct *child, long addr, long data)
  77 {
  78         if ((addr & 3) || addr < 0)
  79                 return -EIO;
  80
  81         if (addr < MAX_REG_OFFSET)
  82                 return putreg(child, addr, data);
  83
  84         else if((addr >= offsetof(struct user, u_debugreg[0])) &&
  85                 (addr <= offsetof(struct user, u_debugreg[7]))){
  86                 addr -= offsetof(struct user, u_debugreg[0]);
  87                 addr = addr >> 2;
  88                 if((addr == 4) || (addr == 5)) return -EIO;
  89                 child->thread.arch.debugregs[addr] = data;
  90                 return 0;
  91         }
  92         return -EIO;
  93 }
  94
  95 unsigned long getreg(struct task_struct *child, int regno)
  96 {
  97         unsigned long retval = ~0UL;
  98
  99         regno >>= 2;
 100         switch (regno) {
 101         case FS:
 102         case GS:
 103         case DS:
 104         case ES:
 105         case SS:
 106         case CS:
 107                 retval = 0xffff;
 108                 /* fall through */
 109         default:
 110                 retval &= PT_REG(&child->thread.regs, regno);
 111         }
 112         return retval;
 113 }
 114
 115 int peek_user(struct task_struct *child, long addr, long data)
 116 {
 117 /* read the word at location addr in the USER area. */
 118         unsigned long tmp;
 119
 120         if ((addr & 3) || addr < 0)
 121                 return -EIO;
 122
 123         tmp = 0;  /* Default return condition */
 124         if(addr < MAX_REG_OFFSET){
 125                 tmp = getreg(child, addr);
 126         }
 127         else if((addr >= offsetof(struct user, u_debugreg[0])) &&
 128                 (addr <= offsetof(struct user, u_debugreg[7]))){
 129                 addr -= offsetof(struct user, u_debugreg[0]);
 130                 addr = addr >> 2;
 131                 tmp = child->thread.arch.debugregs[addr];
 132         }
 133         return put_user(tmp, (unsigned long *) data);
 134 }
 135
 136 struct i387_fxsave_struct {
 137         unsigned short  cwd;
 138         unsigned short  swd;
 139         unsigned short  twd;
 140         unsigned short  fop;
 141         long    fip;
 142         long    fcs;
 143         long    foo;
 144         long    fos;
 145         long    mxcsr;
 146         long    reserved;
 147         long    st_space[32];   /* 8*16 bytes for each FP-reg = 128 bytes */
 148         long    xmm_space[32];  /* 8*16 bytes for each XMM-reg = 128 bytes */
 149         long    padding[56];
 150 };
 151
 152 /*
 153  * FPU tag word conversions.
 154  */
 155
 156 static inline unsigned short twd_i387_to_fxsr( unsigned short twd )
 157 {
 158         unsigned int tmp; /* to avoid 16 bit prefixes in the code */
 159
 160         /* Transform each pair of bits into 01 (valid) or 00 (empty) */
 161         tmp = ~twd;
 162         tmp = (tmp | (tmp>>1)) & 0x5555; /* 0V0V0V0V0V0V0V0V */
 163         /* and move the valid bits to the lower byte. */
 164         tmp = (tmp | (tmp >> 1)) & 0x3333; /* 00VV00VV00VV00VV */
 165         tmp = (tmp | (tmp >> 2)) & 0x0f0f; /* 0000VVVV0000VVVV */
 166         tmp = (tmp | (tmp >> 4)) & 0x00ff; /* 00000000VVVVVVVV */
 167         return tmp;
 168 }
 169
 170 static inline unsigned long twd_fxsr_to_i387( struct i387_fxsave_struct *fxsave )
 171 {
 172         struct _fpxreg *st = NULL;
 173         unsigned long twd = (unsigned long) fxsave->twd;
 174         unsigned long tag;
 175         unsigned long ret = 0xffff0000;
 176         int i;
 177
 178 #define FPREG_ADDR(f, n)        ((char *)&(f)->st_space + (n) * 16);
 179
 180         for ( i = 0 ; i < 8 ; i++ ) {
 181                 if ( twd & 0x1 ) {
 182                         st = (struct _fpxreg *) FPREG_ADDR( fxsave, i );
 183
 184                         switch ( st->exponent & 0x7fff ) {
 185                         case 0x7fff:
 186                                 tag = 2;                /* Special */
 187                                 break;
 188                         case 0x0000:
 189                                 if ( !st->significand[0] &&
 190                                      !st->significand[1] &&
 191                                      !st->significand[2] &&
 192                                      !st->significand[3] ) {
 193                                         tag = 1;        /* Zero */
 194                                 } else {
 195                                         tag = 2;        /* Special */
 196                                 }
 197                                 break;
 198                         default:
 199                                 if ( st->significand[3] & 0x8000 ) {
 200                                         tag = 0;        /* Valid */
 201                                 } else {
 202                                         tag = 2;        /* Special */
 203                                 }
 204                                 break;
 205                         }
 206                 } else {
 207                         tag = 3;                        /* Empty */
 208                 }
 209                 ret |= (tag << (2 * i));
 210                 twd = twd >> 1;
 211         }
 212         return ret;
 213 }
 214
 215 /*
 216  * FXSR floating point environment conversions.
 217  */
 218
 219 #ifdef CONFIG_MODE_TT
 220 static inline int convert_fxsr_to_user_tt(struct _fpstate __user *buf,
 221                                           struct pt_regs *regs)
 222 {
 223         struct i387_fxsave_struct *fxsave = SC_FXSR_ENV(PT_REGS_SC(regs));
 224         unsigned long env[7];
 225         struct _fpreg __user *to;
 226         struct _fpxreg *from;
 227         int i;
 228
 229         env[0] = (unsigned long)fxsave->cwd | 0xffff0000;
 230         env[1] = (unsigned long)fxsave->swd | 0xffff0000;
 231         env[2] = twd_fxsr_to_i387(fxsave);
 232         env[3] = fxsave->fip;
 233         env[4] = fxsave->fcs | ((unsigned long)fxsave->fop << 16);
 234         env[5] = fxsave->foo;
 235         env[6] = fxsave->fos;
 236
 237         if ( __copy_to_user( buf, env, 7 * sizeof(unsigned long) ) )
 238                 return 1;
 239
 240         to = &buf->_st[0];
 241         from = (struct _fpxreg *) &fxsave->st_space[0];
 242         for ( i = 0 ; i < 8 ; i++, to++, from++ ) {
 243                 if ( __copy_to_user( to, from, sizeof(*to) ) )
 244                         return 1;
 245         }
 246         return 0;
 247 }
 248 #endif
 249
 250 static inline int convert_fxsr_to_user(struct _fpstate __user *buf,
 251                                        struct pt_regs *regs)
 252 {
 253         return(CHOOSE_MODE(convert_fxsr_to_user_tt(buf, regs), 0));
 254 }
 255
 256 #ifdef CONFIG_MODE_TT
 257 static inline int convert_fxsr_from_user_tt(struct pt_regs *regs,
 258                                             struct _fpstate __user *buf)
 259 {
 260         struct i387_fxsave_struct *fxsave = SC_FXSR_ENV(PT_REGS_SC(regs));
 261         unsigned long env[7];
 262         struct _fpxreg *to;
 263         struct _fpreg __user *from;
 264         int i;
 265
 266         if ( __copy_from_user( env, buf, 7 * sizeof(long) ) )
 267                 return 1;
 268
 269         fxsave->cwd = (unsigned short)(env[0] & 0xffff);
 270         fxsave->swd = (unsigned short)(env[1] & 0xffff);
 271         fxsave->twd = twd_i387_to_fxsr((unsigned short)(env[2] & 0xffff));
 272         fxsave->fip = env[3];
 273         fxsave->fop = (unsigned short)((env[4] & 0xffff0000) >> 16);
 274         fxsave->fcs = (env[4] & 0xffff);
 275         fxsave->foo = env[5];
 276         fxsave->fos = env[6];
 277
 278         to = (struct _fpxreg *) &fxsave->st_space[0];
 279         from = &buf->_st[0];
 280         for ( i = 0 ; i < 8 ; i++, to++, from++ ) {
 281                 if ( __copy_from_user( to, from, sizeof(*from) ) )
 282                         return 1;
 283         }
 284         return 0;
 285 }
 286 #endif
 287
 288 static inline int convert_fxsr_from_user(struct pt_regs *regs,
 289                                          struct _fpstate __user *buf)
 290 {
 291         return(CHOOSE_MODE(convert_fxsr_from_user_tt(regs, buf), 0));
 292 }
 293
 294 int get_fpregs(unsigned long buf, struct task_struct *child)
 295 {
 296         int err;
 297
 298         err = convert_fxsr_to_user((struct _fpstate __user *) buf,
 299                                    &child->thread.regs);
 300         if(err) return(-EFAULT);
 301         else return(0);
 302 }
 303
 304 int set_fpregs(unsigned long buf, struct task_struct *child)
 305 {
 306         int err;
 307
 308         err = convert_fxsr_from_user(&child->thread.regs,
 309                                      (struct _fpstate __user *) buf);
 310         if(err) return(-EFAULT);
 311         else return(0);
 312 }
 313
 314 #ifdef CONFIG_MODE_TT
 315 int get_fpxregs_tt(unsigned long buf, struct task_struct *tsk)
 316 {
 317         struct pt_regs *regs = &tsk->thread.regs;
 318         struct i387_fxsave_struct *fxsave = SC_FXSR_ENV(PT_REGS_SC(regs));
 319         int err;
 320
 321         err = __copy_to_user((void __user *) buf, fxsave,
 322                              sizeof(struct user_fxsr_struct));
 323         if(err) return -EFAULT;
 324         else return 0;
 325 }
 326 #endif
 327
 328 int get_fpxregs(unsigned long buf, struct task_struct *tsk)
 329 {
 330         return(CHOOSE_MODE(get_fpxregs_tt(buf, tsk), 0));
 331 }
 332
 333 #ifdef CONFIG_MODE_TT
 334 int set_fpxregs_tt(unsigned long buf, struct task_struct *tsk)
 335 {
 336         struct pt_regs *regs = &tsk->thread.regs;
 337         struct i387_fxsave_struct *fxsave = SC_FXSR_ENV(PT_REGS_SC(regs));
 338         int err;
 339
 340         err = __copy_from_user(fxsave, (void __user *) buf,
 341                                sizeof(struct user_fxsr_struct) );
 342         if(err) return -EFAULT;
 343         else return 0;
 344 }
 345 #endif
 346
 347 int set_fpxregs(unsigned long buf, struct task_struct *tsk)
 348 {
 349         return(CHOOSE_MODE(set_fpxregs_tt(buf, tsk), 0));
 350 }
 351
 352 #ifdef notdef
 353 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
 354 {
 355         fpu->cwd = (((SC_FP_CW(PT_REGS_SC(regs)) & 0xffff) << 16) |
 356                     (SC_FP_SW(PT_REGS_SC(regs)) & 0xffff));
 357         fpu->swd = SC_FP_CSSEL(PT_REGS_SC(regs)) & 0xffff;
 358         fpu->twd = SC_FP_IPOFF(PT_REGS_SC(regs));
 359         fpu->fip = SC_FP_CSSEL(PT_REGS_SC(regs)) & 0xffff;
 360         fpu->fcs = SC_FP_DATAOFF(PT_REGS_SC(regs));
 361         fpu->foo = SC_FP_DATASEL(PT_REGS_SC(regs));
 362         fpu->fos = 0;
 363         memcpy(fpu->st_space, (void *) SC_FP_ST(PT_REGS_SC(regs)),
 364                sizeof(fpu->st_space));
 365         return(1);
 366 }
 367 #endif
 368
 369 #ifdef CONFIG_MODE_TT
 370 static inline void copy_fpu_fxsave_tt(struct pt_regs *regs,
 371                                       struct user_i387_struct *buf)
 372 {
 373         struct i387_fxsave_struct *fpu = SC_FXSR_ENV(PT_REGS_SC(regs));
 374         unsigned short *to;
 375         unsigned short *from;
 376         int i;
 377
 378         memcpy( buf, fpu, 7 * sizeof(long) );
 379
 380         to = (unsigned short *) &buf->st_space[0];
 381         from = (unsigned short *) &fpu->st_space[0];
 382         for ( i = 0 ; i < 8 ; i++, to += 5, from += 8 ) {
 383                 memcpy( to, from, 5 * sizeof(unsigned short) );
 384         }
 385 }
 386 #endif
 387
 388 static inline void copy_fpu_fxsave(struct pt_regs *regs,
 389                                    struct user_i387_struct *buf)
 390 {
 391         (void) CHOOSE_MODE(copy_fpu_fxsave_tt(regs, buf), 0);
 392 }
 393
 394 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu )
 395 {
 396         copy_fpu_fxsave(regs, (struct user_i387_struct *) fpu);
 397         return(1);
 398 }
 399
 400 /*
 401  * Overrides for Emacs so that we follow Linus's tabbing style.
 402  * Emacs will notice this stuff at the end of the file and automatically
 403  * adjust the settings for this buffer only.  This must remain at the end
 404  * of the file.
 405  * ---------------------------------------------------------------------------
 406  * Local variables:
 407  * c-file-style: "linux"
 408  * End:
 409  */