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 unsigned long getreg(struct task_struct *child, int regno)
  77 {
  78         unsigned long retval = ~0UL;
  79
  80         regno >>= 2;
  81         switch (regno) {
  82         case FS:
  83         case GS:
  84         case DS:
  85         case ES:
  86         case SS:
  87         case CS:
  88                 retval = 0xffff;
  89                 /* fall through */
  90         default:
  91                 retval &= PT_REG(&child->thread.regs, regno);
  92         }
  93         return retval;
  94 }
  95
  96 struct i387_fxsave_struct {
  97         unsigned short  cwd;
  98         unsigned short  swd;
  99         unsigned short  twd;
 100         unsigned short  fop;
 101         long    fip;
 102         long    fcs;
 103         long    foo;
 104         long    fos;
 105         long    mxcsr;
 106         long    reserved;
 107         long    st_space[32];   /* 8*16 bytes for each FP-reg = 128 bytes */
 108         long    xmm_space[32];  /* 8*16 bytes for each XMM-reg = 128 bytes */
 109         long    padding[56];
 110 };
 111
 112 /*
 113  * FPU tag word conversions.
 114  */
 115
 116 static inline unsigned short twd_i387_to_fxsr( unsigned short twd )
 117 {
 118         unsigned int tmp; /* to avoid 16 bit prefixes in the code */
 119
 120         /* Transform each pair of bits into 01 (valid) or 00 (empty) */
 121         tmp = ~twd;
 122         tmp = (tmp | (tmp>>1)) & 0x5555; /* 0V0V0V0V0V0V0V0V */
 123         /* and move the valid bits to the lower byte. */
 124         tmp = (tmp | (tmp >> 1)) & 0x3333; /* 00VV00VV00VV00VV */
 125         tmp = (tmp | (tmp >> 2)) & 0x0f0f; /* 0000VVVV0000VVVV */
 126         tmp = (tmp | (tmp >> 4)) & 0x00ff; /* 00000000VVVVVVVV */
 127         return tmp;
 128 }
 129
 130 static inline unsigned long twd_fxsr_to_i387( struct i387_fxsave_struct *fxsave )
 131 {
 132         struct _fpxreg *st = NULL;
 133         unsigned long twd = (unsigned long) fxsave->twd;
 134         unsigned long tag;
 135         unsigned long ret = 0xffff0000;
 136         int i;
 137
 138 #define FPREG_ADDR(f, n)        ((char *)&(f)->st_space + (n) * 16);
 139
 140         for ( i = 0 ; i < 8 ; i++ ) {
 141                 if ( twd & 0x1 ) {
 142                         st = (struct _fpxreg *) FPREG_ADDR( fxsave, i );
 143
 144                         switch ( st->exponent & 0x7fff ) {
 145                         case 0x7fff:
 146                                 tag = 2;                /* Special */
 147                                 break;
 148                         case 0x0000:
 149                                 if ( !st->significand[0] &&
 150                                      !st->significand[1] &&
 151                                      !st->significand[2] &&
 152                                      !st->significand[3] ) {
 153                                         tag = 1;        /* Zero */
 154                                 } else {
 155                                         tag = 2;        /* Special */
 156                                 }
 157                                 break;
 158                         default:
 159                                 if ( st->significand[3] & 0x8000 ) {
 160                                         tag = 0;        /* Valid */
 161                                 } else {
 162                                         tag = 2;        /* Special */
 163                                 }
 164                                 break;
 165                         }
 166                 } else {
 167                         tag = 3;                        /* Empty */
 168                 }
 169                 ret |= (tag << (2 * i));
 170                 twd = twd >> 1;
 171         }
 172         return ret;
 173 }
 174
 175 /*
 176  * FXSR floating point environment conversions.
 177  */
 178
 179 #ifdef CONFIG_MODE_TT
 180 static inline int convert_fxsr_to_user_tt(struct _fpstate __user *buf,
 181                                           struct pt_regs *regs)
 182 {
 183         struct i387_fxsave_struct *fxsave = SC_FXSR_ENV(PT_REGS_SC(regs));
 184         unsigned long env[7];
 185         struct _fpreg __user *to;
 186         struct _fpxreg *from;
 187         int i;
 188
 189         env[0] = (unsigned long)fxsave->cwd | 0xffff0000;
 190         env[1] = (unsigned long)fxsave->swd | 0xffff0000;
 191         env[2] = twd_fxsr_to_i387(fxsave);
 192         env[3] = fxsave->fip;
 193         env[4] = fxsave->fcs | ((unsigned long)fxsave->fop << 16);
 194         env[5] = fxsave->foo;
 195         env[6] = fxsave->fos;
 196
 197         if ( __copy_to_user( buf, env, 7 * sizeof(unsigned long) ) )
 198                 return 1;
 199
 200         to = &buf->_st[0];
 201         from = (struct _fpxreg *) &fxsave->st_space[0];
 202         for ( i = 0 ; i < 8 ; i++, to++, from++ ) {
 203                 if ( __copy_to_user( to, from, sizeof(*to) ) )
 204                         return 1;
 205         }
 206         return 0;
 207 }
 208 #endif
 209
 210 static inline int convert_fxsr_to_user(struct _fpstate __user *buf,
 211                                        struct pt_regs *regs)
 212 {
 213         return(CHOOSE_MODE(convert_fxsr_to_user_tt(buf, regs), 0));
 214 }
 215
 216 #ifdef CONFIG_MODE_TT
 217 static inline int convert_fxsr_from_user_tt(struct pt_regs *regs,
 218                                             struct _fpstate __user *buf)
 219 {
 220         struct i387_fxsave_struct *fxsave = SC_FXSR_ENV(PT_REGS_SC(regs));
 221         unsigned long env[7];
 222         struct _fpxreg *to;
 223         struct _fpreg __user *from;
 224         int i;
 225
 226         if ( __copy_from_user( env, buf, 7 * sizeof(long) ) )
 227                 return 1;
 228
 229         fxsave->cwd = (unsigned short)(env[0] & 0xffff);
 230         fxsave->swd = (unsigned short)(env[1] & 0xffff);
 231         fxsave->twd = twd_i387_to_fxsr((unsigned short)(env[2] & 0xffff));
 232         fxsave->fip = env[3];
 233         fxsave->fop = (unsigned short)((env[4] & 0xffff0000) >> 16);
 234         fxsave->fcs = (env[4] & 0xffff);
 235         fxsave->foo = env[5];
 236         fxsave->fos = env[6];
 237
 238         to = (struct _fpxreg *) &fxsave->st_space[0];
 239         from = &buf->_st[0];
 240         for ( i = 0 ; i < 8 ; i++, to++, from++ ) {
 241                 if ( __copy_from_user( to, from, sizeof(*from) ) )
 242                         return 1;
 243         }
 244         return 0;
 245 }
 246 #endif
 247
 248 static inline int convert_fxsr_from_user(struct pt_regs *regs,
 249                                          struct _fpstate __user *buf)
 250 {
 251         return(CHOOSE_MODE(convert_fxsr_from_user_tt(regs, buf), 0));
 252 }
 253
 254 int get_fpregs(unsigned long buf, struct task_struct *child)
 255 {
 256         int err;
 257
 258         err = convert_fxsr_to_user((struct _fpstate __user *) buf,
 259                                    &child->thread.regs);
 260         if(err) return(-EFAULT);
 261         else return(0);
 262 }
 263
 264 int set_fpregs(unsigned long buf, struct task_struct *child)
 265 {
 266         int err;
 267
 268         err = convert_fxsr_from_user(&child->thread.regs,
 269                                      (struct _fpstate __user *) buf);
 270         if(err) return(-EFAULT);
 271         else return(0);
 272 }
 273
 274 #ifdef CONFIG_MODE_TT
 275 int get_fpxregs_tt(unsigned long buf, struct task_struct *tsk)
 276 {
 277         struct pt_regs *regs = &tsk->thread.regs;
 278         struct i387_fxsave_struct *fxsave = SC_FXSR_ENV(PT_REGS_SC(regs));
 279         int err;
 280
 281         err = __copy_to_user((void __user *) buf, fxsave,
 282                              sizeof(struct user_fxsr_struct));
 283         if(err) return -EFAULT;
 284         else return 0;
 285 }
 286 #endif
 287
 288 int get_fpxregs(unsigned long buf, struct task_struct *tsk)
 289 {
 290         return(CHOOSE_MODE(get_fpxregs_tt(buf, tsk), 0));
 291 }
 292
 293 #ifdef CONFIG_MODE_TT
 294 int set_fpxregs_tt(unsigned long buf, struct task_struct *tsk)
 295 {
 296         struct pt_regs *regs = &tsk->thread.regs;
 297         struct i387_fxsave_struct *fxsave = SC_FXSR_ENV(PT_REGS_SC(regs));
 298         int err;
 299
 300         err = __copy_from_user(fxsave, (void __user *) buf,
 301                                sizeof(struct user_fxsr_struct) );
 302         if(err) return -EFAULT;
 303         else return 0;
 304 }
 305 #endif
 306
 307 int set_fpxregs(unsigned long buf, struct task_struct *tsk)
 308 {
 309         return(CHOOSE_MODE(set_fpxregs_tt(buf, tsk), 0));
 310 }
 311
 312 #ifdef notdef
 313 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
 314 {
 315         fpu->cwd = (((SC_FP_CW(PT_REGS_SC(regs)) & 0xffff) << 16) |
 316                     (SC_FP_SW(PT_REGS_SC(regs)) & 0xffff));
 317         fpu->swd = SC_FP_CSSEL(PT_REGS_SC(regs)) & 0xffff;
 318         fpu->twd = SC_FP_IPOFF(PT_REGS_SC(regs));
 319         fpu->fip = SC_FP_CSSEL(PT_REGS_SC(regs)) & 0xffff;
 320         fpu->fcs = SC_FP_DATAOFF(PT_REGS_SC(regs));
 321         fpu->foo = SC_FP_DATASEL(PT_REGS_SC(regs));
 322         fpu->fos = 0;
 323         memcpy(fpu->st_space, (void *) SC_FP_ST(PT_REGS_SC(regs)),
 324                sizeof(fpu->st_space));
 325         return(1);
 326 }
 327 #endif
 328
 329 #ifdef CONFIG_MODE_TT
 330 static inline void copy_fpu_fxsave_tt(struct pt_regs *regs,
 331                                       struct user_i387_struct *buf)
 332 {
 333         struct i387_fxsave_struct *fpu = SC_FXSR_ENV(PT_REGS_SC(regs));
 334         unsigned short *to;
 335         unsigned short *from;
 336         int i;
 337
 338         memcpy( buf, fpu, 7 * sizeof(long) );
 339
 340         to = (unsigned short *) &buf->st_space[0];
 341         from = (unsigned short *) &fpu->st_space[0];
 342         for ( i = 0 ; i < 8 ; i++, to += 5, from += 8 ) {
 343                 memcpy( to, from, 5 * sizeof(unsigned short) );
 344         }
 345 }
 346 #endif
 347
 348 static inline void copy_fpu_fxsave(struct pt_regs *regs,
 349                                    struct user_i387_struct *buf)
 350 {
 351         (void) CHOOSE_MODE(copy_fpu_fxsave_tt(regs, buf), 0);
 352 }
 353
 354 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu )
 355 {
 356         copy_fpu_fxsave(regs, (struct user_i387_struct *) fpu);
 357         return(1);
 358 }
 359
 360 /*
 361  * Overrides for Emacs so that we follow Linus's tabbing style.
 362  * Emacs will notice this stuff at the end of the file and automatically
 363  * adjust the settings for this buffer only.  This must remain at the end
 364  * of the file.
 365  * ---------------------------------------------------------------------------
 366  * Local variables:
 367  * c-file-style: "linux"
 368  * End:
 369  */