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/compiler.h>
   7 #include "linux/sched.h"
   8 #include "linux/mm.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_to_tt(struct task_struct *from, struct task_struct *to)
  18 {
  19         update_debugregs(to->thread.arch.debugregs_seq);
  20         arch_switch_tls_tt(from, to);
  21 }
  22
  23 void arch_switch_to_skas(struct task_struct *from, struct task_struct *to)
  24 {
  25         int err = arch_switch_tls_skas(from, to);
  26         if (!err)
  27                 return;
  28
  29         if (err != -EINVAL)
  30                 printk(KERN_WARNING "arch_switch_tls_skas failed, errno %d, not EINVAL\n", -err);
  31         else
  32                 printk(KERN_WARNING "arch_switch_tls_skas failed, errno = EINVAL\n");
  33 }
  34
  35 int is_syscall(unsigned long addr)
  36 {
  37         unsigned short instr;
  38         int n;
  39
  40         n = copy_from_user(&instr, (void __user *) addr, sizeof(instr));
  41         if(n){
  42                 /* access_process_vm() grants access to vsyscall and stub,
  43                  * while copy_from_user doesn't. Maybe access_process_vm is
  44                  * slow, but that doesn't matter, since it will be called only
  45                  * in case of singlestepping, if copy_from_user failed.
  46                  */
  47                 n = access_process_vm(current, addr, &instr, sizeof(instr), 0);
  48                 if(n != sizeof(instr)) {
  49                         printk("is_syscall : failed to read instruction from "
  50                                "0x%lx\n", addr);
  51                         return(1);
  52                 }
  53         }
  54         /* int 0x80 or sysenter */
  55         return((instr == 0x80cd) || (instr == 0x340f));
  56 }
  57
  58 /* determines which flags the user has access to. */
  59 /* 1 = access 0 = no access */
  60 #define FLAG_MASK 0x00044dd5
  61
  62 int putreg(struct task_struct *child, int regno, unsigned long value)
  63 {
  64         regno >>= 2;
  65         switch (regno) {
  66         case FS:
  67                 if (value && (value & 3) != 3)
  68                         return -EIO;
  69                 PT_REGS_FS(&child->thread.regs) = value;
  70                 return 0;
  71         case GS:
  72                 if (value && (value & 3) != 3)
  73                         return -EIO;
  74                 PT_REGS_GS(&child->thread.regs) = value;
  75                 return 0;
  76         case DS:
  77         case ES:
  78                 if (value && (value & 3) != 3)
  79                         return -EIO;
  80                 value &= 0xffff;
  81                 break;
  82         case SS:
  83         case CS:
  84                 if ((value & 3) != 3)
  85                         return -EIO;
  86                 value &= 0xffff;
  87                 break;
  88         case EFL:
  89                 value &= FLAG_MASK;
  90                 value |= PT_REGS_EFLAGS(&child->thread.regs);
  91                 break;
  92         }
  93         PT_REGS_SET(&child->thread.regs, regno, value);
  94         return 0;
  95 }
  96
  97 int poke_user(struct task_struct *child, long addr, long data)
  98 {
  99         if ((addr & 3) || addr < 0)
 100                 return -EIO;
 101
 102         if (addr < MAX_REG_OFFSET)
 103                 return putreg(child, addr, data);
 104
 105         else if((addr >= offsetof(struct user, u_debugreg[0])) &&
 106                 (addr <= offsetof(struct user, u_debugreg[7]))){
 107                 addr -= offsetof(struct user, u_debugreg[0]);
 108                 addr = addr >> 2;
 109                 if((addr == 4) || (addr == 5)) return -EIO;
 110                 child->thread.arch.debugregs[addr] = data;
 111                 return 0;
 112         }
 113         return -EIO;
 114 }
 115
 116 unsigned long getreg(struct task_struct *child, int regno)
 117 {
 118         unsigned long retval = ~0UL;
 119
 120         regno >>= 2;
 121         switch (regno) {
 122         case FS:
 123         case GS:
 124         case DS:
 125         case ES:
 126         case SS:
 127         case CS:
 128                 retval = 0xffff;
 129                 /* fall through */
 130         default:
 131                 retval &= PT_REG(&child->thread.regs, regno);
 132         }
 133         return retval;
 134 }
 135
 136 int peek_user(struct task_struct *child, long addr, long data)
 137 {
 138 /* read the word at location addr in the USER area. */
 139         unsigned long tmp;
 140
 141         if ((addr & 3) || addr < 0)
 142                 return -EIO;
 143
 144         tmp = 0;  /* Default return condition */
 145         if(addr < MAX_REG_OFFSET){
 146                 tmp = getreg(child, addr);
 147         }
 148         else if((addr >= offsetof(struct user, u_debugreg[0])) &&
 149                 (addr <= offsetof(struct user, u_debugreg[7]))){
 150                 addr -= offsetof(struct user, u_debugreg[0]);
 151                 addr = addr >> 2;
 152                 tmp = child->thread.arch.debugregs[addr];
 153         }
 154         return put_user(tmp, (unsigned long __user *) data);
 155 }
 156
 157 struct i387_fxsave_struct {
 158         unsigned short  cwd;
 159         unsigned short  swd;
 160         unsigned short  twd;
 161         unsigned short  fop;
 162         long    fip;
 163         long    fcs;
 164         long    foo;
 165         long    fos;
 166         long    mxcsr;
 167         long    reserved;
 168         long    st_space[32];   /* 8*16 bytes for each FP-reg = 128 bytes */
 169         long    xmm_space[32];  /* 8*16 bytes for each XMM-reg = 128 bytes */
 170         long    padding[56];
 171 };
 172
 173 /*
 174  * FPU tag word conversions.
 175  */
 176
 177 static inline unsigned short twd_i387_to_fxsr( unsigned short twd )
 178 {
 179         unsigned int tmp; /* to avoid 16 bit prefixes in the code */
 180
 181         /* Transform each pair of bits into 01 (valid) or 00 (empty) */
 182         tmp = ~twd;
 183         tmp = (tmp | (tmp>>1)) & 0x5555; /* 0V0V0V0V0V0V0V0V */
 184         /* and move the valid bits to the lower byte. */
 185         tmp = (tmp | (tmp >> 1)) & 0x3333; /* 00VV00VV00VV00VV */
 186         tmp = (tmp | (tmp >> 2)) & 0x0f0f; /* 0000VVVV0000VVVV */
 187         tmp = (tmp | (tmp >> 4)) & 0x00ff; /* 00000000VVVVVVVV */
 188         return tmp;
 189 }
 190
 191 static inline unsigned long twd_fxsr_to_i387( struct i387_fxsave_struct *fxsave )
 192 {
 193         struct _fpxreg *st = NULL;
 194         unsigned long twd = (unsigned long) fxsave->twd;
 195         unsigned long tag;
 196         unsigned long ret = 0xffff0000;
 197         int i;
 198
 199 #define FPREG_ADDR(f, n)        ((char *)&(f)->st_space + (n) * 16);
 200
 201         for ( i = 0 ; i < 8 ; i++ ) {
 202                 if ( twd & 0x1 ) {
 203                         st = (struct _fpxreg *) FPREG_ADDR( fxsave, i );
 204
 205                         switch ( st->exponent & 0x7fff ) {
 206                         case 0x7fff:
 207                                 tag = 2;                /* Special */
 208                                 break;
 209                         case 0x0000:
 210                                 if ( !st->significand[0] &&
 211                                      !st->significand[1] &&
 212                                      !st->significand[2] &&
 213                                      !st->significand[3] ) {
 214                                         tag = 1;        /* Zero */
 215                                 } else {
 216                                         tag = 2;        /* Special */
 217                                 }
 218                                 break;
 219                         default:
 220                                 if ( st->significand[3] & 0x8000 ) {
 221                                         tag = 0;        /* Valid */
 222                                 } else {
 223                                         tag = 2;        /* Special */
 224                                 }
 225                                 break;
 226                         }
 227                 } else {
 228                         tag = 3;                        /* Empty */
 229                 }
 230                 ret |= (tag << (2 * i));
 231                 twd = twd >> 1;
 232         }
 233         return ret;
 234 }
 235
 236 /*
 237  * FXSR floating point environment conversions.
 238  */
 239
 240 #ifdef CONFIG_MODE_TT
 241 static inline int convert_fxsr_to_user_tt(struct _fpstate __user *buf,
 242                                           struct pt_regs *regs)
 243 {
 244         struct i387_fxsave_struct *fxsave = SC_FXSR_ENV(PT_REGS_SC(regs));
 245         unsigned long env[7];
 246         struct _fpreg __user *to;
 247         struct _fpxreg *from;
 248         int i;
 249
 250         env[0] = (unsigned long)fxsave->cwd | 0xffff0000;
 251         env[1] = (unsigned long)fxsave->swd | 0xffff0000;
 252         env[2] = twd_fxsr_to_i387(fxsave);
 253         env[3] = fxsave->fip;
 254         env[4] = fxsave->fcs | ((unsigned long)fxsave->fop << 16);
 255         env[5] = fxsave->foo;
 256         env[6] = fxsave->fos;
 257
 258         if ( __copy_to_user( buf, env, 7 * sizeof(unsigned long) ) )
 259                 return 1;
 260
 261         to = &buf->_st[0];
 262         from = (struct _fpxreg *) &fxsave->st_space[0];
 263         for ( i = 0 ; i < 8 ; i++, to++, from++ ) {
 264                 if ( __copy_to_user( to, from, sizeof(*to) ) )
 265                         return 1;
 266         }
 267         return 0;
 268 }
 269 #endif
 270
 271 static inline int convert_fxsr_to_user(struct _fpstate __user *buf,
 272                                        struct pt_regs *regs)
 273 {
 274         return(CHOOSE_MODE(convert_fxsr_to_user_tt(buf, regs), 0));
 275 }
 276
 277 #ifdef CONFIG_MODE_TT
 278 static inline int convert_fxsr_from_user_tt(struct pt_regs *regs,
 279                                             struct _fpstate __user *buf)
 280 {
 281         struct i387_fxsave_struct *fxsave = SC_FXSR_ENV(PT_REGS_SC(regs));
 282         unsigned long env[7];
 283         struct _fpxreg *to;
 284         struct _fpreg __user *from;
 285         int i;
 286
 287         if ( __copy_from_user( env, buf, 7 * sizeof(long) ) )
 288                 return 1;
 289
 290         fxsave->cwd = (unsigned short)(env[0] & 0xffff);
 291         fxsave->swd = (unsigned short)(env[1] & 0xffff);
 292         fxsave->twd = twd_i387_to_fxsr((unsigned short)(env[2] & 0xffff));
 293         fxsave->fip = env[3];
 294         fxsave->fop = (unsigned short)((env[4] & 0xffff0000) >> 16);
 295         fxsave->fcs = (env[4] & 0xffff);
 296         fxsave->foo = env[5];
 297         fxsave->fos = env[6];
 298
 299         to = (struct _fpxreg *) &fxsave->st_space[0];
 300         from = &buf->_st[0];
 301         for ( i = 0 ; i < 8 ; i++, to++, from++ ) {
 302                 if ( __copy_from_user( to, from, sizeof(*from) ) )
 303                         return 1;
 304         }
 305         return 0;
 306 }
 307 #endif
 308
 309 static inline int convert_fxsr_from_user(struct pt_regs *regs,
 310                                          struct _fpstate __user *buf)
 311 {
 312         return(CHOOSE_MODE(convert_fxsr_from_user_tt(regs, buf), 0));
 313 }
 314
 315 int get_fpregs(unsigned long buf, struct task_struct *child)
 316 {
 317         int err;
 318
 319         err = convert_fxsr_to_user((struct _fpstate __user *) buf,
 320                                    &child->thread.regs);
 321         if(err) return(-EFAULT);
 322         else return(0);
 323 }
 324
 325 int set_fpregs(unsigned long buf, struct task_struct *child)
 326 {
 327         int err;
 328
 329         err = convert_fxsr_from_user(&child->thread.regs,
 330                                      (struct _fpstate __user *) buf);
 331         if(err) return(-EFAULT);
 332         else return(0);
 333 }
 334
 335 #ifdef CONFIG_MODE_TT
 336 int get_fpxregs_tt(unsigned long buf, struct task_struct *tsk)
 337 {
 338         struct pt_regs *regs = &tsk->thread.regs;
 339         struct i387_fxsave_struct *fxsave = SC_FXSR_ENV(PT_REGS_SC(regs));
 340         int err;
 341
 342         err = __copy_to_user((void __user *) buf, fxsave,
 343                              sizeof(struct user_fxsr_struct));
 344         if(err) return -EFAULT;
 345         else return 0;
 346 }
 347 #endif
 348
 349 int get_fpxregs(unsigned long buf, struct task_struct *tsk)
 350 {
 351         return(CHOOSE_MODE(get_fpxregs_tt(buf, tsk), 0));
 352 }
 353
 354 #ifdef CONFIG_MODE_TT
 355 int set_fpxregs_tt(unsigned long buf, struct task_struct *tsk)
 356 {
 357         struct pt_regs *regs = &tsk->thread.regs;
 358         struct i387_fxsave_struct *fxsave = SC_FXSR_ENV(PT_REGS_SC(regs));
 359         int err;
 360
 361         err = __copy_from_user(fxsave, (void __user *) buf,
 362                                sizeof(struct user_fxsr_struct) );
 363         if(err) return -EFAULT;
 364         else return 0;
 365 }
 366 #endif
 367
 368 int set_fpxregs(unsigned long buf, struct task_struct *tsk)
 369 {
 370         return(CHOOSE_MODE(set_fpxregs_tt(buf, tsk), 0));
 371 }
 372
 373 #ifdef notdef
 374 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
 375 {
 376         fpu->cwd = (((SC_FP_CW(PT_REGS_SC(regs)) & 0xffff) << 16) |
 377                     (SC_FP_SW(PT_REGS_SC(regs)) & 0xffff));
 378         fpu->swd = SC_FP_CSSEL(PT_REGS_SC(regs)) & 0xffff;
 379         fpu->twd = SC_FP_IPOFF(PT_REGS_SC(regs));
 380         fpu->fip = SC_FP_CSSEL(PT_REGS_SC(regs)) & 0xffff;
 381         fpu->fcs = SC_FP_DATAOFF(PT_REGS_SC(regs));
 382         fpu->foo = SC_FP_DATASEL(PT_REGS_SC(regs));
 383         fpu->fos = 0;
 384         memcpy(fpu->st_space, (void *) SC_FP_ST(PT_REGS_SC(regs)),
 385                sizeof(fpu->st_space));
 386         return(1);
 387 }
 388 #endif
 389
 390 #ifdef CONFIG_MODE_TT
 391 static inline void copy_fpu_fxsave_tt(struct pt_regs *regs,
 392                                       struct user_i387_struct *buf)
 393 {
 394         struct i387_fxsave_struct *fpu = SC_FXSR_ENV(PT_REGS_SC(regs));
 395         unsigned short *to;
 396         unsigned short *from;
 397         int i;
 398
 399         memcpy( buf, fpu, 7 * sizeof(long) );
 400
 401         to = (unsigned short *) &buf->st_space[0];
 402         from = (unsigned short *) &fpu->st_space[0];
 403         for ( i = 0 ; i < 8 ; i++, to += 5, from += 8 ) {
 404                 memcpy( to, from, 5 * sizeof(unsigned short) );
 405         }
 406 }
 407 #endif
 408
 409 static inline void copy_fpu_fxsave(struct pt_regs *regs,
 410                                    struct user_i387_struct *buf)
 411 {
 412         (void) CHOOSE_MODE(copy_fpu_fxsave_tt(regs, buf), 0);
 413 }
 414
 415 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu )
 416 {
 417         copy_fpu_fxsave(regs, (struct user_i387_struct *) fpu);
 418         return(1);
 419 }
 420
 421 /*
 422  * Overrides for Emacs so that we follow Linus's tabbing style.
 423  * Emacs will notice this stuff at the end of the file and automatically
 424  * adjust the settings for this buffer only.  This must remain at the end
 425  * of the file.
 426  * ---------------------------------------------------------------------------
 427  * Local variables:
 428  * c-file-style: "linux"
 429  * End:
 430  */