arch/sparc/kernel/ptrace.c

   1 /* ptrace.c: Sparc process tracing support.
   2  *
   3  * Copyright (C) 1996 David S. Miller (davem@caipfs.rutgers.edu)
   4  *
   5  * Based upon code written by Ross Biro, Linus Torvalds, Bob Manson,
   6  * and David Mosberger.
   7  *
   8  * Added Linux support -miguel (weird, eh?, the orignal code was meant
   9  * to emulate SunOS).
  10  */
  11
  12 #include <linux/kernel.h>
  13 #include <linux/sched.h>
  14 #include <linux/mm.h>
  15 #include <linux/errno.h>
  16 #include <linux/ptrace.h>
  17 #include <linux/user.h>
  18 #include <linux/smp.h>
  19 #include <linux/smp_lock.h>
  20 #include <linux/security.h>
  21 #include <linux/signal.h>
  22 #include <linux/vs_base.h>
  23
  24 #include <asm/pgtable.h>
  25 #include <asm/system.h>
  26 #include <asm/uaccess.h>
  27
  28 #define MAGIC_CONSTANT 0x80000000
  29
  30
  31 /* Returning from ptrace is a bit tricky because the syscall return
  32  * low level code assumes any value returned which is negative and
  33  * is a valid errno will mean setting the condition codes to indicate
  34  * an error return.  This doesn't work, so we have this hook.
  35  */
  36 static inline void pt_error_return(struct pt_regs *regs, unsigned long error)
  37 {
  38         regs->u_regs[UREG_I0] = error;
  39         regs->psr |= PSR_C;
  40         regs->pc = regs->npc;
  41         regs->npc += 4;
  42 }
  43
  44 static inline void pt_succ_return(struct pt_regs *regs, unsigned long value)
  45 {
  46         regs->u_regs[UREG_I0] = value;
  47         regs->psr &= ~PSR_C;
  48         regs->pc = regs->npc;
  49         regs->npc += 4;
  50 }
  51
  52 static void
  53 pt_succ_return_linux(struct pt_regs *regs, unsigned long value, long __user *addr)
  54 {
  55         if (put_user(value, addr)) {
  56                 pt_error_return(regs, EFAULT);
  57                 return;
  58         }
  59         regs->u_regs[UREG_I0] = 0;
  60         regs->psr &= ~PSR_C;
  61         regs->pc = regs->npc;
  62         regs->npc += 4;
  63 }
  64
  65 static void
  66 pt_os_succ_return (struct pt_regs *regs, unsigned long val, long __user *addr)
  67 {
  68         if (current->personality == PER_SUNOS)
  69                 pt_succ_return (regs, val);
  70         else
  71                 pt_succ_return_linux (regs, val, addr);
  72 }
  73
  74 /* Fuck me gently with a chainsaw... */
  75 static inline void read_sunos_user(struct pt_regs *regs, unsigned long offset,
  76                                    struct task_struct *tsk, long __user *addr)
  77 {
  78         struct pt_regs *cregs = tsk->thread.kregs;
  79         struct thread_info *t = task_thread_info(tsk);
  80         int v;
  81
  82         if(offset >= 1024)
  83                 offset -= 1024; /* whee... */
  84         if(offset & ((sizeof(unsigned long) - 1))) {
  85                 pt_error_return(regs, EIO);
  86                 return;
  87         }
  88         if(offset >= 16 && offset < 784) {
  89                 offset -= 16; offset >>= 2;
  90                 pt_os_succ_return(regs, *(((unsigned long *)(&t->reg_window[0]))+offset), addr);
  91                 return;
  92         }
  93         if(offset >= 784 && offset < 832) {
  94                 offset -= 784; offset >>= 2;
  95                 pt_os_succ_return(regs, *(((unsigned long *)(&t->rwbuf_stkptrs[0]))+offset), addr);
  96                 return;
  97         }
  98         switch(offset) {
  99         case 0:
 100                 v = t->ksp;
 101                 break;
 102         case 4:
 103                 v = t->kpc;
 104                 break;
 105         case 8:
 106                 v = t->kpsr;
 107                 break;
 108         case 12:
 109                 v = t->uwinmask;
 110                 break;
 111         case 832:
 112                 v = t->w_saved;
 113                 break;
 114         case 896:
 115                 v = cregs->u_regs[UREG_I0];
 116                 break;
 117         case 900:
 118                 v = cregs->u_regs[UREG_I1];
 119                 break;
 120         case 904:
 121                 v = cregs->u_regs[UREG_I2];
 122                 break;
 123         case 908:
 124                 v = cregs->u_regs[UREG_I3];
 125                 break;
 126         case 912:
 127                 v = cregs->u_regs[UREG_I4];
 128                 break;
 129         case 916:
 130                 v = cregs->u_regs[UREG_I5];
 131                 break;
 132         case 920:
 133                 v = cregs->u_regs[UREG_I6];
 134                 break;
 135         case 924:
 136                 if(tsk->thread.flags & MAGIC_CONSTANT)
 137                         v = cregs->u_regs[UREG_G1];
 138                 else
 139                         v = 0;
 140                 break;
 141         case 940:
 142                 v = cregs->u_regs[UREG_I0];
 143                 break;
 144         case 944:
 145                 v = cregs->u_regs[UREG_I1];
 146                 break;
 147
 148         case 948:
 149                 /* Isn't binary compatibility _fun_??? */
 150                 if(cregs->psr & PSR_C)
 151                         v = cregs->u_regs[UREG_I0] << 24;
 152                 else
 153                         v = 0;
 154                 break;
 155
 156                 /* Rest of them are completely unsupported. */
 157         default:
 158                 printk("%s [%d]: Wants to read user offset %ld\n",
 159                        current->comm, current->pid, offset);
 160                 pt_error_return(regs, EIO);
 161                 return;
 162         }
 163         if (current->personality == PER_SUNOS)
 164                 pt_succ_return (regs, v);
 165         else
 166                 pt_succ_return_linux (regs, v, addr);
 167         return;
 168 }
 169
 170 static inline void write_sunos_user(struct pt_regs *regs, unsigned long offset,
 171                                     struct task_struct *tsk)
 172 {
 173         struct pt_regs *cregs = tsk->thread.kregs;
 174         struct thread_info *t = task_thread_info(tsk);
 175         unsigned long value = regs->u_regs[UREG_I3];
 176
 177         if(offset >= 1024)
 178                 offset -= 1024; /* whee... */
 179         if(offset & ((sizeof(unsigned long) - 1)))
 180                 goto failure;
 181         if(offset >= 16 && offset < 784) {
 182                 offset -= 16; offset >>= 2;
 183                 *(((unsigned long *)(&t->reg_window[0]))+offset) = value;
 184                 goto success;
 185         }
 186         if(offset >= 784 && offset < 832) {
 187                 offset -= 784; offset >>= 2;
 188                 *(((unsigned long *)(&t->rwbuf_stkptrs[0]))+offset) = value;
 189                 goto success;
 190         }
 191         switch(offset) {
 192         case 896:
 193                 cregs->u_regs[UREG_I0] = value;
 194                 break;
 195         case 900:
 196                 cregs->u_regs[UREG_I1] = value;
 197                 break;
 198         case 904:
 199                 cregs->u_regs[UREG_I2] = value;
 200                 break;
 201         case 908:
 202                 cregs->u_regs[UREG_I3] = value;
 203                 break;
 204         case 912:
 205                 cregs->u_regs[UREG_I4] = value;
 206                 break;
 207         case 916:
 208                 cregs->u_regs[UREG_I5] = value;
 209                 break;
 210         case 920:
 211                 cregs->u_regs[UREG_I6] = value;
 212                 break;
 213         case 924:
 214                 cregs->u_regs[UREG_I7] = value;
 215                 break;
 216         case 940:
 217                 cregs->u_regs[UREG_I0] = value;
 218                 break;
 219         case 944:
 220                 cregs->u_regs[UREG_I1] = value;
 221                 break;
 222
 223                 /* Rest of them are completely unsupported or "no-touch". */
 224         default:
 225                 printk("%s [%d]: Wants to write user offset %ld\n",
 226                        current->comm, current->pid, offset);
 227                 goto failure;
 228         }
 229 success:
 230         pt_succ_return(regs, 0);
 231         return;
 232 failure:
 233         pt_error_return(regs, EIO);
 234         return;
 235 }
 236
 237 /* #define ALLOW_INIT_TRACING */
 238 /* #define DEBUG_PTRACE */
 239
 240 #ifdef DEBUG_PTRACE
 241 char *pt_rq [] = {
 242         /* 0  */ "TRACEME", "PEEKTEXT", "PEEKDATA", "PEEKUSR",
 243         /* 4  */ "POKETEXT", "POKEDATA", "POKEUSR", "CONT",
 244         /* 8  */ "KILL", "SINGLESTEP", "SUNATTACH", "SUNDETACH",
 245         /* 12 */ "GETREGS", "SETREGS", "GETFPREGS", "SETFPREGS",
 246         /* 16 */ "READDATA", "WRITEDATA", "READTEXT", "WRITETEXT",
 247         /* 20 */ "GETFPAREGS", "SETFPAREGS", "unknown", "unknown",
 248         /* 24 */ "SYSCALL", ""
 249 };
 250 #endif
 251
 252 /*
 253  * Called by kernel/ptrace.c when detaching..
 254  *
 255  * Make sure single step bits etc are not set.
 256  */
 257 void ptrace_disable(struct task_struct *child)
 258 {
 259         /* nothing to do */
 260 }
 261
 262 asmlinkage void do_ptrace(struct pt_regs *regs)
 263 {
 264         unsigned long request = regs->u_regs[UREG_I0];
 265         unsigned long pid = regs->u_regs[UREG_I1];
 266         unsigned long addr = regs->u_regs[UREG_I2];
 267         unsigned long data = regs->u_regs[UREG_I3];
 268         unsigned long addr2 = regs->u_regs[UREG_I4];
 269         struct task_struct *child;
 270         int ret;
 271
 272         lock_kernel();
 273 #ifdef DEBUG_PTRACE
 274         {
 275                 char *s;
 276
 277                 if ((request >= 0) && (request <= 24))
 278                         s = pt_rq [request];
 279                 else
 280                         s = "unknown";
 281
 282                 if (request == PTRACE_POKEDATA && data == 0x91d02001){
 283                         printk ("do_ptrace: breakpoint pid=%d, addr=%08lx addr2=%08lx\n",
 284                                 pid, addr, addr2);
 285                 } else
 286                         printk("do_ptrace: rq=%s(%d) pid=%d addr=%08lx data=%08lx addr2=%08lx\n",
 287                                s, (int) request, (int) pid, addr, data, addr2);
 288         }
 289 #endif
 290
 291         if (request == PTRACE_TRACEME) {
 292                 ret = ptrace_traceme();
 293                 if (ret < 0)
 294                         pt_error_return(regs, -ret);
 295                 else
 296                         pt_succ_return(regs, 0);
 297                 goto out;
 298         }
 299
 300         child = ptrace_get_task_struct(pid);
 301         if (IS_ERR(child)) {
 302                 ret = PTR_ERR(child);
 303                 pt_error_return(regs, -ret);
 304                 goto out;
 305         }
 306         if (!vx_check(vx_task_xid(child), VS_WATCH_P|VS_IDENT)) {
 307                 pt_error_return(regs, ESRCH);
 308                 goto out_tsk;
 309         }
 310
 311         if ((current->personality == PER_SUNOS && request == PTRACE_SUNATTACH)
 312             || (current->personality != PER_SUNOS && request == PTRACE_ATTACH)) {
 313                 if (ptrace_attach(child)) {
 314                         pt_error_return(regs, EPERM);
 315                         goto out_tsk;
 316                 }
 317                 pt_succ_return(regs, 0);
 318                 goto out_tsk;
 319         }
 320
 321         ret = ptrace_check_attach(child, request == PTRACE_KILL);
 322         if (ret < 0) {
 323                 pt_error_return(regs, -ret);
 324                 goto out_tsk;
 325         }
 326
 327         switch(request) {
 328         case PTRACE_PEEKTEXT: /* read word at location addr. */
 329         case PTRACE_PEEKDATA: {
 330                 unsigned long tmp;
 331
 332                 if (access_process_vm(child, addr,
 333                                       &tmp, sizeof(tmp), 0) == sizeof(tmp))
 334                         pt_os_succ_return(regs, tmp, (long __user *)data);
 335                 else
 336                         pt_error_return(regs, EIO);
 337                 goto out_tsk;
 338         }
 339
 340         case PTRACE_PEEKUSR:
 341                 read_sunos_user(regs, addr, child, (long __user *) data);
 342                 goto out_tsk;
 343
 344         case PTRACE_POKEUSR:
 345                 write_sunos_user(regs, addr, child);
 346                 goto out_tsk;
 347
 348         case PTRACE_POKETEXT: /* write the word at location addr. */
 349         case PTRACE_POKEDATA: {
 350                 if (access_process_vm(child, addr,
 351                                       &data, sizeof(data), 1) == sizeof(data))
 352                         pt_succ_return(regs, 0);
 353                 else
 354                         pt_error_return(regs, EIO);
 355                 goto out_tsk;
 356         }
 357
 358         case PTRACE_GETREGS: {
 359                 struct pt_regs __user *pregs = (struct pt_regs __user *) addr;
 360                 struct pt_regs *cregs = child->thread.kregs;
 361                 int rval;
 362
 363                 if (!access_ok(VERIFY_WRITE, pregs, sizeof(struct pt_regs))) {
 364                         rval = -EFAULT;
 365                         pt_error_return(regs, -rval);
 366                         goto out_tsk;
 367                 }
 368                 __put_user(cregs->psr, (&pregs->psr));
 369                 __put_user(cregs->pc, (&pregs->pc));
 370                 __put_user(cregs->npc, (&pregs->npc));
 371                 __put_user(cregs->y, (&pregs->y));
 372                 for(rval = 1; rval < 16; rval++)
 373                         __put_user(cregs->u_regs[rval], (&pregs->u_regs[rval - 1]));
 374                 pt_succ_return(regs, 0);
 375 #ifdef DEBUG_PTRACE
 376                 printk ("PC=%x nPC=%x o7=%x\n", cregs->pc, cregs->npc, cregs->u_regs [15]);
 377 #endif
 378                 goto out_tsk;
 379         }
 380
 381         case PTRACE_SETREGS: {
 382                 struct pt_regs __user *pregs = (struct pt_regs __user *) addr;
 383                 struct pt_regs *cregs = child->thread.kregs;
 384                 unsigned long psr, pc, npc, y;
 385                 int i;
 386
 387                 /* Must be careful, tracing process can only set certain
 388                  * bits in the psr.
 389                  */
 390                 if (!access_ok(VERIFY_READ, pregs, sizeof(struct pt_regs))) {
 391                         pt_error_return(regs, EFAULT);
 392                         goto out_tsk;
 393                 }
 394                 __get_user(psr, (&pregs->psr));
 395                 __get_user(pc, (&pregs->pc));
 396                 __get_user(npc, (&pregs->npc));
 397                 __get_user(y, (&pregs->y));
 398                 psr &= PSR_ICC;
 399                 cregs->psr &= ~PSR_ICC;
 400                 cregs->psr |= psr;
 401                 if (!((pc | npc) & 3)) {
 402                         cregs->pc = pc;
 403                         cregs->npc =npc;
 404                 }
 405                 cregs->y = y;
 406                 for(i = 1; i < 16; i++)
 407                         __get_user(cregs->u_regs[i], (&pregs->u_regs[i-1]));
 408                 pt_succ_return(regs, 0);
 409                 goto out_tsk;
 410         }
 411
 412         case PTRACE_GETFPREGS: {
 413                 struct fps {
 414                         unsigned long regs[32];
 415                         unsigned long fsr;
 416                         unsigned long flags;
 417                         unsigned long extra;
 418                         unsigned long fpqd;
 419                         struct fq {
 420                                 unsigned long *insnaddr;
 421                                 unsigned long insn;
 422                         } fpq[16];
 423                 };
 424                 struct fps __user *fps = (struct fps __user *) addr;
 425                 int i;
 426
 427                 if (!access_ok(VERIFY_WRITE, fps, sizeof(struct fps))) {
 428                         i = -EFAULT;
 429                         pt_error_return(regs, -i);
 430                         goto out_tsk;
 431                 }
 432                 for(i = 0; i < 32; i++)
 433                         __put_user(child->thread.float_regs[i], (&fps->regs[i]));
 434                 __put_user(child->thread.fsr, (&fps->fsr));
 435                 __put_user(child->thread.fpqdepth, (&fps->fpqd));
 436                 __put_user(0, (&fps->flags));
 437                 __put_user(0, (&fps->extra));
 438                 for(i = 0; i < 16; i++) {
 439                         __put_user(child->thread.fpqueue[i].insn_addr,
 440                                    (&fps->fpq[i].insnaddr));
 441                         __put_user(child->thread.fpqueue[i].insn, (&fps->fpq[i].insn));
 442                 }
 443                 pt_succ_return(regs, 0);
 444                 goto out_tsk;
 445         }
 446
 447         case PTRACE_SETFPREGS: {
 448                 struct fps {
 449                         unsigned long regs[32];
 450                         unsigned long fsr;
 451                         unsigned long flags;
 452                         unsigned long extra;
 453                         unsigned long fpqd;
 454                         struct fq {
 455                                 unsigned long *insnaddr;
 456                                 unsigned long insn;
 457                         } fpq[16];
 458                 };
 459                 struct fps __user *fps = (struct fps __user *) addr;
 460                 int i;
 461
 462                 if (!access_ok(VERIFY_READ, fps, sizeof(struct fps))) {
 463                         i = -EFAULT;
 464                         pt_error_return(regs, -i);
 465                         goto out_tsk;
 466                 }
 467                 copy_from_user(&child->thread.float_regs[0], &fps->regs[0], (32 * sizeof(unsigned long)));
 468                 __get_user(child->thread.fsr, (&fps->fsr));
 469                 __get_user(child->thread.fpqdepth, (&fps->fpqd));
 470                 for(i = 0; i < 16; i++) {
 471                         __get_user(child->thread.fpqueue[i].insn_addr,
 472                                    (&fps->fpq[i].insnaddr));
 473                         __get_user(child->thread.fpqueue[i].insn, (&fps->fpq[i].insn));
 474                 }
 475                 pt_succ_return(regs, 0);
 476                 goto out_tsk;
 477         }
 478
 479         case PTRACE_READTEXT:
 480         case PTRACE_READDATA: {
 481                 int res = ptrace_readdata(child, addr,
 482                                           (void __user *) addr2, data);
 483
 484                 if (res == data) {
 485                         pt_succ_return(regs, 0);
 486                         goto out_tsk;
 487                 }
 488                 /* Partial read is an IO failure */
 489                 if (res >= 0)
 490                         res = -EIO;
 491                 pt_error_return(regs, -res);
 492                 goto out_tsk;
 493         }
 494
 495         case PTRACE_WRITETEXT:
 496         case PTRACE_WRITEDATA: {
 497                 int res = ptrace_writedata(child, (void __user *) addr2,
 498                                            addr, data);
 499
 500                 if (res == data) {
 501                         pt_succ_return(regs, 0);
 502                         goto out_tsk;
 503                 }
 504                 /* Partial write is an IO failure */
 505                 if (res >= 0)
 506                         res = -EIO;
 507                 pt_error_return(regs, -res);
 508                 goto out_tsk;
 509         }
 510
 511         case PTRACE_SYSCALL: /* continue and stop at (return from) syscall */
 512                 addr = 1;
 513
 514         case PTRACE_CONT: { /* restart after signal. */
 515                 if (!valid_signal(data)) {
 516                         pt_error_return(regs, EIO);
 517                         goto out_tsk;
 518                 }
 519
 520                 if (request == PTRACE_SYSCALL)
 521                         set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
 522                 else
 523                         clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
 524
 525                 child->exit_code = data;
 526 #ifdef DEBUG_PTRACE
 527                 printk("CONT: %s [%d]: set exit_code = %x %lx %lx\n",
 528                         child->comm, child->pid, child->exit_code,
 529                         child->thread.kregs->pc,
 530                         child->thread.kregs->npc);
 531 #endif
 532                 wake_up_process(child);
 533                 pt_succ_return(regs, 0);
 534                 goto out_tsk;
 535         }
 536
 537 /*
 538  * make the child exit.  Best I can do is send it a sigkill.
 539  * perhaps it should be put in the status that it wants to
 540  * exit.
 541  */
 542         case PTRACE_KILL: {
 543                 if (child->exit_state == EXIT_ZOMBIE) { /* already dead */
 544                         pt_succ_return(regs, 0);
 545                         goto out_tsk;
 546                 }
 547                 wake_up_process(child);
 548                 child->exit_code = SIGKILL;
 549                 pt_succ_return(regs, 0);
 550                 goto out_tsk;
 551         }
 552
 553         case PTRACE_SUNDETACH: { /* detach a process that was attached. */
 554                 int err = ptrace_detach(child, data);
 555                 if (err) {
 556                         pt_error_return(regs, EIO);
 557                         goto out_tsk;
 558                 }
 559                 pt_succ_return(regs, 0);
 560                 goto out_tsk;
 561         }
 562
 563         /* PTRACE_DUMPCORE unsupported... */
 564
 565         default: {
 566                 int err = ptrace_request(child, request, addr, data);
 567                 if (err)
 568                         pt_error_return(regs, -err);
 569                 else
 570                         pt_succ_return(regs, 0);
 571                 goto out_tsk;
 572         }
 573         }
 574 out_tsk:
 575         if (child)
 576                 put_task_struct(child);
 577 out:
 578         unlock_kernel();
 579 }
 580
 581 asmlinkage void syscall_trace(void)
 582 {
 583 #ifdef DEBUG_PTRACE
 584         printk("%s [%d]: syscall_trace\n", current->comm, current->pid);
 585 #endif
 586         if (!test_thread_flag(TIF_SYSCALL_TRACE))
 587                 return;
 588         if (!(current->ptrace & PT_PTRACED))
 589                 return;
 590         current->thread.flags ^= MAGIC_CONSTANT;
 591         ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
 592                                  ? 0x80 : 0));
 593         /*
 594          * this isn't the same as continuing with a signal, but it will do
 595          * for normal use.  strace only continues with a signal if the
 596          * stopping signal is not SIGTRAP.  -brl
 597          */
 598 #ifdef DEBUG_PTRACE
 599         printk("%s [%d]: syscall_trace exit= %x\n", current->comm,
 600                 current->pid, current->exit_code);
 601 #endif
 602         if (current->exit_code) {
 603                 send_sig (current->exit_code, current, 1);
 604                 current->exit_code = 0;
 605         }
 606 }