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 "linux/mm.h"
  10 #include "asm/elf.h"
  11 #include "asm/ptrace.h"
  12 #include "asm/uaccess.h"
  13 #include "asm/unistd.h"
  14 #include "sysdep/ptrace.h"
  15 #include "sysdep/sigcontext.h"
  16 #include "sysdep/sc.h"
  17
  18 void arch_switch_to_tt(struct task_struct *from, struct task_struct *to)
  19 {
  20         update_debugregs(to->thread.arch.debugregs_seq);
  21         arch_switch_tls_tt(from, to);
  22 }
  23
  24 void arch_switch_to_skas(struct task_struct *from, struct task_struct *to)
  25 {
  26         int err = arch_switch_tls_skas(from, to);
  27         if (!err)
  28                 return;
  29
  30         if (err != -EINVAL)
  31                 printk(KERN_WARNING "arch_switch_tls_skas failed, errno %d, not EINVAL\n", -err);
  32         else
  33                 printk(KERN_WARNING "arch_switch_tls_skas failed, errno = EINVAL\n");
  34 }
  35
  36 int is_syscall(unsigned long addr)
  37 {
  38         unsigned short instr;
  39         int n;
  40
  41         n = copy_from_user(&instr, (void __user *) addr, sizeof(instr));
  42         if(n){
  43                 /* access_process_vm() grants access to vsyscall and stub,
  44                  * while copy_from_user doesn't. Maybe access_process_vm is
  45                  * slow, but that doesn't matter, since it will be called only
  46                  * in case of singlestepping, if copy_from_user failed.
  47                  */
  48                 n = access_process_vm(current, addr, &instr, sizeof(instr), 0);
  49                 if(n != sizeof(instr)) {
  50                         printk("is_syscall : failed to read instruction from "
  51                                "0x%lx\n", addr);
  52                         return(1);
  53                 }
  54         }
  55         /* int 0x80 or sysenter */
  56         return((instr == 0x80cd) || (instr == 0x340f));
  57 }
  58
  59 /* determines which flags the user has access to. */
  60 /* 1 = access 0 = no access */
  61 #define FLAG_MASK 0x00044dd5
  62
  63 int putreg(struct task_struct *child, int regno, unsigned long value)
  64 {
  65         regno >>= 2;
  66         switch (regno) {
  67         case FS:
  68                 if (value && (value & 3) != 3)
  69                         return -EIO;
  70                 PT_REGS_FS(&child->thread.regs) = value;
  71                 return 0;
  72         case GS:
  73                 if (value && (value & 3) != 3)
  74                         return -EIO;
  75                 PT_REGS_GS(&child->thread.regs) = value;
  76                 return 0;
  77         case DS:
  78         case ES:
  79                 if (value && (value & 3) != 3)
  80                         return -EIO;
  81                 value &= 0xffff;
  82                 break;
  83         case SS:
  84         case CS:
  85                 if ((value & 3) != 3)
  86                         return -EIO;
  87                 value &= 0xffff;
  88                 break;
  89         case EFL:
  90                 value &= FLAG_MASK;
  91                 value |= PT_REGS_EFLAGS(&child->thread.regs);
  92                 break;
  93         }
  94         PT_REGS_SET(&child->thread.regs, regno, value);
  95         return 0;
  96 }
  97
  98 int poke_user(struct task_struct *child, long addr, long data)
  99 {
 100         if ((addr & 3) || addr < 0)
 101                 return -EIO;
 102
 103         if (addr < MAX_REG_OFFSET)
 104                 return putreg(child, addr, data);
 105
 106         else if((addr >= offsetof(struct user, u_debugreg[0])) &&
 107                 (addr <= offsetof(struct user, u_debugreg[7]))){
 108                 addr -= offsetof(struct user, u_debugreg[0]);
 109                 addr = addr >> 2;
 110                 if((addr == 4) || (addr == 5)) return -EIO;
 111                 child->thread.arch.debugregs[addr] = data;
 112                 return 0;
 113         }
 114         return -EIO;
 115 }
 116
 117 unsigned long getreg(struct task_struct *child, int regno)
 118 {
 119         unsigned long retval = ~0UL;
 120
 121         regno >>= 2;
 122         switch (regno) {
 123         case FS:
 124         case GS:
 125         case DS:
 126         case ES:
 127         case SS:
 128         case CS:
 129                 retval = 0xffff;
 130                 /* fall through */
 131         default:
 132                 retval &= PT_REG(&child->thread.regs, regno);
 133         }
 134         return retval;
 135 }
 136
 137 int peek_user(struct task_struct *child, long addr, long data)
 138 {
 139 /* read the word at location addr in the USER area. */
 140         unsigned long tmp;
 141
 142         if ((addr & 3) || addr < 0)
 143                 return -EIO;
 144
 145         tmp = 0;  /* Default return condition */
 146         if(addr < MAX_REG_OFFSET){
 147                 tmp = getreg(child, addr);
 148         }
 149         else if((addr >= offsetof(struct user, u_debugreg[0])) &&
 150                 (addr <= offsetof(struct user, u_debugreg[7]))){
 151                 addr -= offsetof(struct user, u_debugreg[0]);
 152                 addr = addr >> 2;
 153                 tmp = child->thread.arch.debugregs[addr];
 154         }
 155         return put_user(tmp, (unsigned long __user *) data);
 156 }
 157
 158 struct i387_fxsave_struct {
 159         unsigned short  cwd;
 160         unsigned short  swd;
 161         unsigned short  twd;
 162         unsigned short  fop;
 163         long    fip;
 164         long    fcs;
 165         long    foo;
 166         long    fos;
 167         long    mxcsr;
 168         long    reserved;
 169         long    st_space[32];   /* 8*16 bytes for each FP-reg = 128 bytes */
 170         long    xmm_space[32];  /* 8*16 bytes for each XMM-reg = 128 bytes */
 171         long    padding[56];
 172 };
 173
 174 /*
 175  * FPU tag word conversions.
 176  */
 177
 178 static inline unsigned short twd_i387_to_fxsr( unsigned short twd )
 179 {
 180         unsigned int tmp; /* to avoid 16 bit prefixes in the code */
 181
 182         /* Transform each pair of bits into 01 (valid) or 00 (empty) */
 183         tmp = ~twd;
 184         tmp = (tmp | (tmp>>1)) & 0x5555; /* 0V0V0V0V0V0V0V0V */
 185         /* and move the valid bits to the lower byte. */
 186         tmp = (tmp | (tmp >> 1)) & 0x3333; /* 00VV00VV00VV00VV */
 187         tmp = (tmp | (tmp >> 2)) & 0x0f0f; /* 0000VVVV0000VVVV */
 188         tmp = (tmp | (tmp >> 4)) & 0x00ff; /* 00000000VVVVVVVV */
 189         return tmp;
 190 }
 191
 192 static inline unsigned long twd_fxsr_to_i387( struct i387_fxsave_struct *fxsave )
 193 {
 194         struct _fpxreg *st = NULL;
 195         unsigned long twd = (unsigned long) fxsave->twd;
 196         unsigned long tag;
 197         unsigned long ret = 0xffff0000;
 198         int i;
 199
 200 #define FPREG_ADDR(f, n)        ((char *)&(f)->st_space + (n) * 16);
 201
 202         for ( i = 0 ; i < 8 ; i++ ) {
 203                 if ( twd & 0x1 ) {
 204                         st = (struct _fpxreg *) FPREG_ADDR( fxsave, i );
 205
 206                         switch ( st->exponent & 0x7fff ) {
 207                         case 0x7fff:
 208                                 tag = 2;                /* Special */
 209                                 break;
 210                         case 0x0000:
 211                                 if ( !st->significand[0] &&
 212                                      !st->significand[1] &&
 213                                      !st->significand[2] &&
 214                                      !st->significand[3] ) {
 215                                         tag = 1;        /* Zero */
 216                                 } else {
 217                                         tag = 2;        /* Special */
 218                                 }
 219                                 break;
 220                         default:
 221                                 if ( st->significand[3] & 0x8000 ) {
 222                                         tag = 0;        /* Valid */
 223                                 } else {
 224                                         tag = 2;        /* Special */
 225                                 }
 226                                 break;
 227                         }
 228                 } else {
 229                         tag = 3;                        /* Empty */
 230                 }
 231                 ret |= (tag << (2 * i));
 232                 twd = twd >> 1;
 233         }
 234         return ret;
 235 }
 236
 237 /*
 238  * FXSR floating point environment conversions.
 239  */
 240
 241 #ifdef CONFIG_MODE_TT
 242 static inline int convert_fxsr_to_user_tt(struct _fpstate __user *buf,
 243                                           struct pt_regs *regs)
 244 {
 245         struct i387_fxsave_struct *fxsave = SC_FXSR_ENV(PT_REGS_SC(regs));
 246         unsigned long env[7];
 247         struct _fpreg __user *to;
 248         struct _fpxreg *from;
 249         int i;
 250
 251         env[0] = (unsigned long)fxsave->cwd | 0xffff0000;
 252         env[1] = (unsigned long)fxsave->swd | 0xffff0000;
 253         env[2] = twd_fxsr_to_i387(fxsave);
 254         env[3] = fxsave->fip;
 255         env[4] = fxsave->fcs | ((unsigned long)fxsave->fop << 16);
 256         env[5] = fxsave->foo;
 257         env[6] = fxsave->fos;
 258
 259         if ( __copy_to_user( buf, env, 7 * sizeof(unsigned long) ) )
 260                 return 1;
 261
 262         to = &buf->_st[0];
 263         from = (struct _fpxreg *) &fxsave->st_space[0];
 264         for ( i = 0 ; i < 8 ; i++, to++, from++ ) {
 265                 if ( __copy_to_user( to, from, sizeof(*to) ) )
 266                         return 1;
 267         }
 268         return 0;
 269 }
 270 #endif
 271
 272 static inline int convert_fxsr_to_user(struct _fpstate __user *buf,
 273                                        struct pt_regs *regs)
 274 {
 275         return(CHOOSE_MODE(convert_fxsr_to_user_tt(buf, regs), 0));
 276 }
 277
 278 #ifdef CONFIG_MODE_TT
 279 static inline int convert_fxsr_from_user_tt(struct pt_regs *regs,
 280                                             struct _fpstate __user *buf)
 281 {
 282         struct i387_fxsave_struct *fxsave = SC_FXSR_ENV(PT_REGS_SC(regs));
 283         unsigned long env[7];
 284         struct _fpxreg *to;
 285         struct _fpreg __user *from;
 286         int i;
 287
 288         if ( __copy_from_user( env, buf, 7 * sizeof(long) ) )
 289                 return 1;
 290
 291         fxsave->cwd = (unsigned short)(env[0] & 0xffff);
 292         fxsave->swd = (unsigned short)(env[1] & 0xffff);
 293         fxsave->twd = twd_i387_to_fxsr((unsigned short)(env[2] & 0xffff));
 294         fxsave->fip = env[3];
 295         fxsave->fop = (unsigned short)((env[4] & 0xffff0000) >> 16);
 296         fxsave->fcs = (env[4] & 0xffff);
 297         fxsave->foo = env[5];
 298         fxsave->fos = env[6];
 299
 300         to = (struct _fpxreg *) &fxsave->st_space[0];
 301         from = &buf->_st[0];
 302         for ( i = 0 ; i < 8 ; i++, to++, from++ ) {
 303                 if ( __copy_from_user( to, from, sizeof(*from) ) )
 304                         return 1;
 305         }
 306         return 0;
 307 }
 308 #endif
 309
 310 static inline int convert_fxsr_from_user(struct pt_regs *regs,
 311                                          struct _fpstate __user *buf)
 312 {
 313         return(CHOOSE_MODE(convert_fxsr_from_user_tt(regs, buf), 0));
 314 }
 315
 316 int get_fpregs(unsigned long buf, struct task_struct *child)
 317 {
 318         int err;
 319
 320         err = convert_fxsr_to_user((struct _fpstate __user *) buf,
 321                                    &child->thread.regs);
 322         if(err) return(-EFAULT);
 323         else return(0);
 324 }
 325
 326 int set_fpregs(unsigned long buf, struct task_struct *child)
 327 {
 328         int err;
 329
 330         err = convert_fxsr_from_user(&child->thread.regs,
 331                                      (struct _fpstate __user *) buf);
 332         if(err) return(-EFAULT);
 333         else return(0);
 334 }
 335
 336 #ifdef CONFIG_MODE_TT
 337 int get_fpxregs_tt(unsigned long buf, struct task_struct *tsk)
 338 {
 339         struct pt_regs *regs = &tsk->thread.regs;
 340         struct i387_fxsave_struct *fxsave = SC_FXSR_ENV(PT_REGS_SC(regs));
 341         int err;
 342
 343         err = __copy_to_user((void __user *) buf, fxsave,
 344                              sizeof(struct user_fxsr_struct));
 345         if(err) return -EFAULT;
 346         else return 0;
 347 }
 348 #endif
 349
 350 int get_fpxregs(unsigned long buf, struct task_struct *tsk)
 351 {
 352         return(CHOOSE_MODE(get_fpxregs_tt(buf, tsk), 0));
 353 }
 354
 355 #ifdef CONFIG_MODE_TT
 356 int set_fpxregs_tt(unsigned long buf, struct task_struct *tsk)
 357 {
 358         struct pt_regs *regs = &tsk->thread.regs;
 359         struct i387_fxsave_struct *fxsave = SC_FXSR_ENV(PT_REGS_SC(regs));
 360         int err;
 361
 362         err = __copy_from_user(fxsave, (void __user *) buf,
 363                                sizeof(struct user_fxsr_struct) );
 364         if(err) return -EFAULT;
 365         else return 0;
 366 }
 367 #endif
 368
 369 int set_fpxregs(unsigned long buf, struct task_struct *tsk)
 370 {
 371         return(CHOOSE_MODE(set_fpxregs_tt(buf, tsk), 0));
 372 }
 373
 374 #ifdef notdef
 375 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
 376 {
 377         fpu->cwd = (((SC_FP_CW(PT_REGS_SC(regs)) & 0xffff) << 16) |
 378                     (SC_FP_SW(PT_REGS_SC(regs)) & 0xffff));
 379         fpu->swd = SC_FP_CSSEL(PT_REGS_SC(regs)) & 0xffff;
 380         fpu->twd = SC_FP_IPOFF(PT_REGS_SC(regs));
 381         fpu->fip = SC_FP_CSSEL(PT_REGS_SC(regs)) & 0xffff;
 382         fpu->fcs = SC_FP_DATAOFF(PT_REGS_SC(regs));
 383         fpu->foo = SC_FP_DATASEL(PT_REGS_SC(regs));
 384         fpu->fos = 0;
 385         memcpy(fpu->st_space, (void *) SC_FP_ST(PT_REGS_SC(regs)),
 386                sizeof(fpu->st_space));
 387         return(1);
 388 }
 389 #endif
 390
 391 #ifdef CONFIG_MODE_TT
 392 static inline void copy_fpu_fxsave_tt(struct pt_regs *regs,
 393                                       struct user_i387_struct *buf)
 394 {
 395         struct i387_fxsave_struct *fpu = SC_FXSR_ENV(PT_REGS_SC(regs));
 396         unsigned short *to;
 397         unsigned short *from;
 398         int i;
 399
 400         memcpy( buf, fpu, 7 * sizeof(long) );
 401
 402         to = (unsigned short *) &buf->st_space[0];
 403         from = (unsigned short *) &fpu->st_space[0];
 404         for ( i = 0 ; i < 8 ; i++, to += 5, from += 8 ) {
 405                 memcpy( to, from, 5 * sizeof(unsigned short) );
 406         }
 407 }
 408 #endif
 409
 410 static inline void copy_fpu_fxsave(struct pt_regs *regs,
 411                                    struct user_i387_struct *buf)
 412 {
 413         (void) CHOOSE_MODE(copy_fpu_fxsave_tt(regs, buf), 0);
 414 }
 415
 416 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu )
 417 {
 418         copy_fpu_fxsave(regs, (struct user_i387_struct *) fpu);
 419         return(1);
 420 }
 421
 422 /*
 423  * Overrides for Emacs so that we follow Linus's tabbing style.
 424  * Emacs will notice this stuff at the end of the file and automatically
 425  * adjust the settings for this buffer only.  This must remain at the end
 426  * of the file.
 427  * ---------------------------------------------------------------------------
 428  * Local variables:
 429  * c-file-style: "linux"
 430  * End:
 431  */