arch/sparc/kernel/ptrace.c

/* */
This source file includes following definitions.
get_task
get_long
put_long
find_extend_vma
read_long
read_byte
write_long
write_byte
pt_error_return
pt_succ_return
read_sunos_user
write_sunos_user
do_ptrace
syscall_trace
   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 
   9 #include <linux/kernel.h>
  10 #include <linux/sched.h>
  11 #include <linux/mm.h>
  12 #include <linux/errno.h>
  13 #include <linux/ptrace.h>
  14 #include <linux/user.h>
  15 
  16 #include <asm/pgtable.h>
  17 #include <asm/system.h>
  18 
  19 /* change a pid into a task struct. */
  20 static inline struct task_struct * get_task(int pid)
     /*  */
  21 {
  22         int i;
  23 
  24         for (i = 1; i < NR_TASKS; i++) {
  25                 if (task[i] != NULL && (task[i]->pid == pid))
  26                         return task[i];
  27         }
  28         return NULL;
  29 }
  30 
  31 /*
  32  * This routine gets a long from any process space by following the page
  33  * tables. NOTE! You should check that the long isn't on a page boundary,
  34  * and that it is in the task area before calling this: this routine does
  35  * no checking.
  36  */
  37 static unsigned long get_long(struct task_struct * tsk,
     /*  */
  38         struct vm_area_struct * vma, unsigned long addr)
  39 {
  40         pgd_t * pgdir;
  41         pmd_t * pgmiddle;
  42         pte_t * pgtable;
  43         unsigned long page, retval;
  44 
  45 repeat:
  46         pgdir = pgd_offset(vma->vm_mm, addr);
  47         if (pgd_none(*pgdir)) {
  48                 do_no_page(tsk, vma, addr, 0);
  49                 goto repeat;
  50         }
  51         if (pgd_bad(*pgdir)) {
  52                 printk("ptrace: bad page directory %08lx\n", pgd_val(*pgdir));
  53                 pgd_clear(pgdir);
  54                 return 0;
  55         }
  56         pgmiddle = pmd_offset(pgdir, addr);
  57         if (pmd_none(*pgmiddle)) {
  58                 do_no_page(tsk, vma, addr, 0);
  59                 goto repeat;
  60         }
  61         if (pmd_bad(*pgmiddle)) {
  62                 printk("ptrace: bad page middle %08lx\n", pmd_val(*pgmiddle));
  63                 pmd_clear(pgmiddle);
  64                 return 0;
  65         }
  66         pgtable = pte_offset(pgmiddle, addr);
  67         if (!pte_present(*pgtable)) {
  68                 do_no_page(tsk, vma, addr, 0);
  69                 goto repeat;
  70         }
  71         page = pte_page(*pgtable);
  72 /* this is a hack for non-kernel-mapped video buffers and similar */
  73         if (page >= high_memory)
  74                 return 0;
  75         page += addr & ~PAGE_MASK;
  76         retval = *(unsigned long *) page;
  77         flush_page_to_ram(page);
  78         return retval;
  79 }
  80 
  81 /*
  82  * This routine puts a long into any process space by following the page
  83  * tables. NOTE! You should check that the long isn't on a page boundary,
  84  * and that it is in the task area before calling this: this routine does
  85  * no checking.
  86  *
  87  * Now keeps R/W state of page so that a text page stays readonly
  88  * even if a debugger scribbles breakpoints into it.  -M.U-
  89  */
  90 static void put_long(struct task_struct * tsk, struct vm_area_struct * vma,
     /*  */
  91         unsigned long addr, unsigned long data)
  92 {
  93         pgd_t *pgdir;
  94         pmd_t *pgmiddle;
  95         pte_t *pgtable;
  96         unsigned long page;
  97 
  98 repeat:
  99         pgdir = pgd_offset(vma->vm_mm, addr);
 100         if (!pgd_present(*pgdir)) {
 101                 do_no_page(tsk, vma, addr, 1);
 102                 goto repeat;
 103         }
 104         if (pgd_bad(*pgdir)) {
 105                 printk("ptrace: bad page directory %08lx\n", pgd_val(*pgdir));
 106                 pgd_clear(pgdir);
 107                 return;
 108         }
 109         pgmiddle = pmd_offset(pgdir, addr);
 110         if (pmd_none(*pgmiddle)) {
 111                 do_no_page(tsk, vma, addr, 1);
 112                 goto repeat;
 113         }
 114         if (pmd_bad(*pgmiddle)) {
 115                 printk("ptrace: bad page middle %08lx\n", pmd_val(*pgmiddle));
 116                 pmd_clear(pgmiddle);
 117                 return;
 118         }
 119         pgtable = pte_offset(pgmiddle, addr);
 120         if (!pte_present(*pgtable)) {
 121                 do_no_page(tsk, vma, addr, 1);
 122                 goto repeat;
 123         }
 124         page = pte_page(*pgtable);
 125         if (!pte_write(*pgtable)) {
 126                 do_wp_page(tsk, vma, addr, 1);
 127                 goto repeat;
 128         }
 129 /* this is a hack for non-kernel-mapped video buffers and similar */
 130         flush_cache_page(vma, page);
 131         if (page < high_memory) {
 132                 *(unsigned long *) (page + (addr & ~PAGE_MASK)) = data;
 133                 flush_page_to_ram(page);
 134         }
 135 /* we're bypassing pagetables, so we have to set the dirty bit ourselves */
 136 /* this should also re-instate whatever read-only mode there was before */
 137         set_pte(pgtable, pte_mkdirty(mk_pte(page, vma->vm_page_prot)));
 138         flush_tlb_page(vma, page);
 139 }
 140 
 141 static struct vm_area_struct * find_extend_vma(struct task_struct * tsk,
     /*  */
 142                                                unsigned long addr)
 143 {
 144         struct vm_area_struct * vma;
 145 
 146         addr &= PAGE_MASK;
 147         vma = find_vma(tsk,addr);
 148         if (!vma)
 149                 return NULL;
 150         if (vma->vm_start <= addr)
 151                 return vma;
 152         if (!(vma->vm_flags & VM_GROWSDOWN))
 153                 return NULL;
 154         if (vma->vm_end - addr > tsk->rlim[RLIMIT_STACK].rlim_cur)
 155                 return NULL;
 156         vma->vm_offset -= vma->vm_start - addr;
 157         vma->vm_start = addr;
 158         return vma;
 159 }
 160 
 161 /*
 162  * This routine checks the page boundaries, and that the offset is
 163  * within the task area. It then calls get_long() to read a long.
 164  */
 165 static int read_long(struct task_struct * tsk, unsigned long addr,
     /*  */
 166                      unsigned long * result)
 167 {
 168         struct vm_area_struct * vma = find_extend_vma(tsk, addr);
 169 
 170         if (!vma)
 171                 return -EIO;
 172         *result = get_long(tsk, vma, addr);
 173         return 0;
 174 }
 175 
 176 static int read_byte(struct task_struct *tsk, unsigned long addr,
     /*  */
 177                      unsigned char *result)
 178 {
 179         struct vm_area_struct *vma = find_extend_vma(tsk, addr&~3);
 180         unsigned long tmp;
 181 
 182         if(!vma)
 183                 return -EIO;
 184         tmp = get_long(tsk, vma, (addr & ~3));
 185         switch(addr & 3) {
 186         case 0:
 187                 *result = (tmp & 0xff000000)>>24;
 188                 break;
 189         case 1:
 190                 *result = (tmp & 0x00ff0000)>>16;
 191                 break;
 192         case 2:
 193                 *result = (tmp & 0x0000ff00)>>8;
 194                 break;
 195         case 3:
 196                 *result = (tmp & 0x000000ff);
 197                 break;
 198         }
 199         return 0;
 200 }
 201 
 202 /*
 203  * This routine checks the page boundaries, and that the offset is
 204  * within the task area. It then calls put_long() to write a long.
 205  */
 206 static int write_long(struct task_struct * tsk, unsigned long addr,
     /*  */
 207                       unsigned long data)
 208 {
 209         struct vm_area_struct * vma = find_extend_vma(tsk, addr);
 210 
 211         if (!vma)
 212                 return -EIO;
 213         put_long(tsk, vma, addr, data);
 214         return 0;
 215 }
 216 
 217 static int write_byte(struct task_struct * tsk, unsigned long addr,
     /*  */
 218                       unsigned char data)
 219 {
 220         struct vm_area_struct * vma = find_extend_vma(tsk, (addr & ~3));
 221         unsigned long tmp;
 222 
 223         if (!vma)
 224                 return -EIO;
 225         tmp = get_long(tsk, vma, (addr & ~3));
 226         switch(addr & 3) {
 227         case 0:
 228                 tmp &= 0x00ffffff;
 229                 tmp |= (data << 24);
 230                 break;
 231         case 1:
 232                 tmp &= 0xff00ffff;
 233                 tmp |= ((data << 16) & 0x00ff0000);
 234                 break;
 235         case 2:
 236                 tmp &= 0xffff00ff;
 237                 tmp |= ((data << 8) & 0x0000ff00);
 238                 break;
 239         case 3:
 240                 tmp &= 0xffffff00;
 241                 tmp |= (data & 0x000000ff);
 242                 break;
 243         }
 244         put_long(tsk, vma, (addr & ~3), tmp);
 245         return 0;
 246 }
 247 
 248 /* Returning from ptrace is a bit tricky because the syscall return
 249  * low level code assumes any value returned which is negative and
 250  * is a valid errno will mean setting the condition codes to indicate
 251  * an error return.  This doesn't work, so we have this hook.
 252  */
 253 static inline void pt_error_return(struct pt_regs *regs, unsigned long error)
     /*  */
 254 {
 255         regs->u_regs[UREG_I0] = error;
 256         regs->psr |= PSR_C;
 257         regs->pc = regs->npc;
 258         regs->npc += 4;
 259 }
 260 
 261 static inline void pt_succ_return(struct pt_regs *regs, unsigned long value)
     /*  */
 262 {
 263         regs->u_regs[UREG_I0] = value;
 264         regs->psr &= ~PSR_C;
 265         regs->pc = regs->npc;
 266         regs->npc += 4;
 267 }
 268 
 269 /* Fuck me gently with a chainsaw... */
 270 static inline void read_sunos_user(struct pt_regs *regs, unsigned long offset,
     /*  */
 271                                    struct task_struct *tsk)
 272 {
 273         struct pt_regs *cregs = tsk->tss.kregs;
 274         struct thread_struct *t = &tsk->tss;
 275 
 276         if(offset >= 1024)
 277                 offset -= 1024; /* whee... */
 278         if(offset & ((sizeof(unsigned long) - 1))) {
 279                 pt_error_return(regs, EIO);
 280                 return;
 281         }
 282         if(offset >= 16 && offset < 784) {
 283                 offset -= 16; offset >>= 2;
 284                 pt_succ_return(regs, *(((unsigned long *)(&t->reg_window[0]))+offset)); 
 285                 return;
 286         }
 287         if(offset >= 784 && offset < 832) {
 288                 offset -= 784; offset >>= 2;
 289                 pt_succ_return(regs, *(((unsigned long *)(&t->rwbuf_stkptrs[0]))+offset));
 290                 return;
 291         }
 292         switch(offset) {
 293         case 0:
 294                 regs->u_regs[UREG_I0] = t->ksp;
 295                 break;
 296         case 4:
 297                 regs->u_regs[UREG_I0] = t->kpc;
 298                 break;
 299         case 8:
 300                 regs->u_regs[UREG_I0] = t->kpsr;
 301                 break;
 302         case 12:
 303                 regs->u_regs[UREG_I0] = t->uwinmask;
 304                 break;
 305         case 832:
 306                 regs->u_regs[UREG_I0] = t->w_saved;
 307                 break;
 308         case 896:
 309                 regs->u_regs[UREG_I0] = cregs->u_regs[UREG_I0];
 310                 break;
 311         case 900:
 312                 regs->u_regs[UREG_I0] = cregs->u_regs[UREG_I1];
 313                 break;
 314         case 904:
 315                 regs->u_regs[UREG_I0] = cregs->u_regs[UREG_I2];
 316                 break;
 317         case 908:
 318                 regs->u_regs[UREG_I0] = cregs->u_regs[UREG_I3];
 319                 break;
 320         case 912:
 321                 regs->u_regs[UREG_I0] = cregs->u_regs[UREG_I4];
 322                 break;
 323         case 916:
 324                 regs->u_regs[UREG_I0] = cregs->u_regs[UREG_I5];
 325                 break;
 326         case 920:
 327                 regs->u_regs[UREG_I0] = cregs->u_regs[UREG_I6];
 328                 break;
 329         case 924:
 330                 if(tsk->tss.flags & 0x80000000)
 331                         regs->u_regs[UREG_I0] = cregs->u_regs[UREG_G1];
 332                 else
 333                         regs->u_regs[UREG_I0] = 0;
 334                 break;
 335         case 940:
 336                 regs->u_regs[UREG_I0] = cregs->u_regs[UREG_I0];
 337                 break;
 338         case 944:
 339                 regs->u_regs[UREG_I0] = cregs->u_regs[UREG_I1];
 340                 break;
 341 
 342         case 948:
 343                 /* Isn't binary compatability _fun_??? */
 344                 if(cregs->psr & PSR_C)
 345                         regs->u_regs[UREG_I0] = cregs->u_regs[UREG_I0] << 24;
 346                 else
 347                         regs->u_regs[UREG_I0] = 0;
 348                 break;
 349 
 350                 /* Rest of them are completely unsupported. */
 351         default:
 352                 printk("%s [%d]: Wants to read user offset %d\n",
 353                        current->comm, current->pid, offset);
 354                 pt_error_return(regs, EIO);
 355                 return;
 356         }
 357         regs->psr &= ~PSR_C;
 358         regs->pc = regs->npc;
 359         regs->npc += 4;
 360         return;
 361 }
 362 
 363 static inline void write_sunos_user(struct pt_regs *regs, unsigned long offset,
     /*  */
 364                                     struct task_struct *tsk)
 365 {
 366         struct pt_regs *cregs = tsk->tss.kregs;
 367         struct thread_struct *t = &tsk->tss;
 368         unsigned long value = regs->u_regs[UREG_I3];
 369 
 370         if(offset >= 1024)
 371                 offset -= 1024; /* whee... */
 372         if(offset & ((sizeof(unsigned long) - 1)))
 373                 goto failure;
 374         if(offset >= 16 && offset < 784) {
 375                 offset -= 16; offset >>= 2;
 376                 *(((unsigned long *)(&t->reg_window[0]))+offset) = value;
 377                 goto success;
 378         }
 379         if(offset >= 784 && offset < 832) {
 380                 offset -= 784; offset >>= 2;
 381                 *(((unsigned long *)(&t->rwbuf_stkptrs[0]))+offset) = value;
 382                 goto success;
 383         }
 384         switch(offset) {
 385         case 896:
 386                 cregs->u_regs[UREG_I0] = value;
 387                 break;
 388         case 900:
 389                 cregs->u_regs[UREG_I1] = value;
 390                 break;
 391         case 904:
 392                 cregs->u_regs[UREG_I2] = value;
 393                 break;
 394         case 908:
 395                 cregs->u_regs[UREG_I3] = value;
 396                 break;
 397         case 912:
 398                 cregs->u_regs[UREG_I4] = value;
 399                 break;
 400         case 916:
 401                 cregs->u_regs[UREG_I5] = value;
 402                 break;
 403         case 920:
 404                 cregs->u_regs[UREG_I6] = value;
 405                 break;
 406         case 924:
 407                 cregs->u_regs[UREG_I7] = value;
 408                 break;
 409         case 940:
 410                 cregs->u_regs[UREG_I0] = value;
 411                 break;
 412         case 944:
 413                 cregs->u_regs[UREG_I1] = value;
 414                 break;
 415 
 416                 /* Rest of them are completely unsupported or "no-touch". */
 417         default:
 418                 printk("%s [%d]: Wants to write user offset %d\n",
 419                        current->comm, current->pid, offset);
 420                 goto failure;
 421         }
 422 success:
 423         pt_succ_return(regs, 0);
 424         return;
 425 failure:
 426         pt_error_return(regs, EIO);
 427         return;
 428 }
 429 
 430 /* #define ALLOW_INIT_TRACING */
 431 /* #define DEBUG_PTRACE */
 432 
 433 asmlinkage void do_ptrace(struct pt_regs *regs)
     /*  */
 434 {
 435         unsigned long request = regs->u_regs[UREG_I0];
 436         unsigned long pid = regs->u_regs[UREG_I1];
 437         unsigned long addr = regs->u_regs[UREG_I2];
 438         unsigned long data = regs->u_regs[UREG_I3];
 439         unsigned long addr2 = regs->u_regs[UREG_I4];
 440         struct task_struct *child;
 441 
 442 #ifdef DEBUG_PTRACE
 443         printk("do_ptrace: rq=%d pid=%d addr=%08lx data=%08lx addr2=%08lx\n",
 444                (int) request, (int) pid, addr, data, addr2);
 445 #endif
 446         if(request == PTRACE_TRACEME) {
 447                 /* are we already being traced? */
 448                 if (current->flags & PF_PTRACED) {
 449                         pt_error_return(regs, EPERM);
 450                         return;
 451                 }
 452                 /* set the ptrace bit in the process flags. */
 453                 current->flags |= PF_PTRACED;
 454                 pt_succ_return(regs, 0);
 455                 return;
 456         }
 457 #ifndef ALLOW_INIT_TRACING
 458         if(pid == 1) {
 459                 /* Can't dork with init. */
 460                 pt_error_return(regs, EPERM);
 461                 return;
 462         }
 463 #endif
 464         if(!(child = get_task(pid))) {
 465                 pt_error_return(regs, ESRCH);
 466                 return;
 467         }
 468 
 469         if(request == PTRACE_SUNATTACH) {
 470                 if(child == current) {
 471                         /* Try this under SunOS/Solaris, bwa haha
 472                          * You'll never be able to kill the process. ;-)
 473                          */
 474                         pt_error_return(regs, EPERM);
 475                         return;
 476                 }
 477                 if((!child->dumpable ||
 478                     (current->uid != child->euid) ||
 479                     (current->uid != child->uid) ||
 480                     (current->gid != child->egid) ||
 481                     (current->gid != child->gid)) && !suser()) {
 482                         pt_error_return(regs, EPERM);
 483                         return;
 484                 }
 485                 /* the same process cannot be attached many times */
 486                 if (child->flags & PF_PTRACED) {
 487                         pt_error_return(regs, EPERM);
 488                         return;
 489                 }
 490                 child->flags |= PF_PTRACED;
 491                 if(child->p_pptr != current) {
 492                         REMOVE_LINKS(child);
 493                         child->p_pptr = current;
 494                         SET_LINKS(child);
 495                 }
 496                 send_sig(SIGSTOP, child, 1);
 497                 pt_succ_return(regs, 0);
 498                 return;
 499         }
 500         if(!(child->flags & PF_PTRACED)) {
 501                 pt_error_return(regs, ESRCH);
 502                 return;
 503         }
 504         if(child->state != TASK_STOPPED) {
 505                 if(request != PTRACE_KILL) {
 506                         pt_error_return(regs, ESRCH);
 507                         return;
 508                 }
 509         }
 510         if(child->p_pptr != current) {
 511                 pt_error_return(regs, ESRCH);
 512                 return;
 513         }
 514         switch(request) {
 515         case PTRACE_PEEKTEXT: /* read word at location addr. */ 
 516         case PTRACE_PEEKDATA: {
 517                 unsigned long tmp;
 518                 int res;
 519 
 520                 /* Non-word alignment _not_ allowed on Sparc. */
 521                 if(addr & (sizeof(unsigned long) - 1)) {
 522                         pt_error_return(regs, EINVAL);
 523                         return;
 524                 }
 525                 res = read_long(child, addr, &tmp);
 526                 if (res < 0) {
 527                         pt_error_return(regs, -res);
 528                         return;
 529                 }
 530                 pt_succ_return(regs, tmp);
 531                 return;
 532         }
 533 
 534         case PTRACE_PEEKUSR:
 535                 read_sunos_user(regs, addr, child);
 536                 return;
 537 
 538         case PTRACE_POKEUSR:
 539                 write_sunos_user(regs, addr, child);
 540                 return;
 541 
 542         case PTRACE_POKETEXT: /* write the word at location addr. */
 543         case PTRACE_POKEDATA: {
 544                 struct vm_area_struct *vma;
 545                 int res;
 546 
 547                 /* Non-word alignment _not_ allowed on Sparc. */
 548                 if(addr & (sizeof(unsigned long) - 1)) {
 549                         pt_error_return(regs, EINVAL);
 550                         return;
 551                 }
 552                 vma = find_extend_vma(child, addr);
 553                 if(vma && request == PTRACE_POKEDATA && (vma->vm_flags & VM_EXEC)) {
 554                         pt_error_return(regs, EIO);
 555                         return;
 556                 }
 557                 res = write_long(child, addr, data);
 558                 if(res < 0)
 559                         pt_error_return(regs, -res);
 560                 else
 561                         pt_succ_return(regs, res);
 562                 return;
 563         }
 564 
 565         case PTRACE_GETREGS: {
 566                 struct pt_regs *pregs = (struct pt_regs *) addr;
 567                 struct pt_regs *cregs = child->tss.kregs;
 568                 int rval;
 569 
 570                 rval = verify_area(VERIFY_WRITE, pregs, sizeof(struct pt_regs) - 4);
 571                 if(rval) {
 572                         pt_error_return(regs, rval);
 573                         return;
 574                 }
 575                 pregs->psr = cregs->psr;
 576                 pregs->pc = cregs->pc;
 577                 pregs->npc = cregs->npc;
 578                 pregs->y = cregs->y;
 579                 for(rval = 1; rval < 16; rval++)
 580                         pregs->u_regs[rval - 1] = cregs->u_regs[rval];
 581                 pt_succ_return(regs, 0);
 582                 return;
 583         }
 584 
 585         case PTRACE_SETREGS: {
 586                 struct pt_regs *pregs = (struct pt_regs *) addr;
 587                 struct pt_regs *cregs = child->tss.kregs;
 588                 unsigned long psr;
 589                 int rval, i;
 590 
 591                 rval = verify_area(VERIFY_READ, pregs, sizeof(struct pt_regs) - 4);
 592                 if(rval) {
 593                         pt_error_return(regs, rval);
 594                         return;
 595                 }
 596                 /* Must be careful, tracing process can only set certain
 597                  * bits in the psr.
 598                  */
 599                 psr = (pregs->psr) & PSR_ICC;
 600                 cregs->psr &= ~PSR_ICC;
 601                 cregs->psr |= psr;
 602                 if(!((pregs->pc | pregs->npc) & 3)) {
 603                         cregs->pc = pregs->pc;
 604                         cregs->npc = pregs->npc;
 605                 }
 606                 cregs->y = pregs->y;
 607                 for(i = 1; i < 16; i++)
 608                         cregs->u_regs[i] = pregs->u_regs[i-1];
 609                 pt_succ_return(regs, 0);
 610                 return;
 611         }
 612 
 613         case PTRACE_GETFPREGS: {
 614                 struct fps {
 615                         unsigned long regs[32];
 616                         unsigned long fsr;
 617                         unsigned long flags;
 618                         unsigned long extra;
 619                         unsigned long fpqd;
 620                         struct fq {
 621                                 unsigned long *insnaddr;
 622                                 unsigned long insn;
 623                         } fpq[16];
 624                 } *fps = (struct fps *) addr;
 625                 int rval, i;
 626 
 627                 rval = verify_area(VERIFY_WRITE, fps, sizeof(struct fps));
 628                 if(rval) { pt_error_return(regs, rval); return; }
 629                 for(i = 0; i < 32; i++)
 630                         fps->regs[i] = child->tss.float_regs[i];
 631                 fps->fsr = child->tss.fsr;
 632                 fps->fpqd = child->tss.fpqdepth;
 633                 fps->flags = fps->extra = 0;
 634                 for(i = 0; i < 16; i++) {
 635                         fps->fpq[i].insnaddr = child->tss.fpqueue[i].insn_addr;
 636                         fps->fpq[i].insn = child->tss.fpqueue[i].insn;
 637                 }
 638                 pt_succ_return(regs, 0);
 639                 return;
 640         }
 641 
 642         case PTRACE_SETFPREGS: {
 643                 struct fps {
 644                         unsigned long regs[32];
 645                         unsigned long fsr;
 646                         unsigned long flags;
 647                         unsigned long extra;
 648                         unsigned long fpqd;
 649                         struct fq {
 650                                 unsigned long *insnaddr;
 651                                 unsigned long insn;
 652                         } fpq[16];
 653                 } *fps = (struct fps *) addr;
 654                 int rval, i;
 655 
 656                 rval = verify_area(VERIFY_READ, fps, sizeof(struct fps));
 657                 if(rval) { pt_error_return(regs, rval); return; }
 658                 for(i = 0; i < 32; i++)
 659                         child->tss.float_regs[i] = fps->regs[i];
 660                 child->tss.fsr = fps->fsr;
 661                 child->tss.fpqdepth = fps->fpqd;
 662                 for(i = 0; i < 16; i++) {
 663                         child->tss.fpqueue[i].insn_addr = fps->fpq[i].insnaddr;
 664                         child->tss.fpqueue[i].insn = fps->fpq[i].insn;
 665                 }
 666                 pt_succ_return(regs, 0);
 667                 return;
 668         }
 669 
 670         case PTRACE_READTEXT:
 671         case PTRACE_READDATA: {
 672                 unsigned char *dest = (unsigned char *) addr2;
 673                 unsigned long src = addr;
 674                 unsigned char tmp;
 675                 int res, len = data;
 676 
 677                 res = verify_area(VERIFY_WRITE, (void *) dest, len);
 678                 if(res) {
 679                         pt_error_return(regs, -res);
 680                         return;
 681                 }
 682                 while(len) {
 683                         res = read_byte(child, src, &tmp);
 684                         if(res < 0) {
 685                                 pt_error_return(regs, -res);
 686                                 return;
 687                         }
 688                         *dest = tmp;
 689                         src++; dest++; len--;
 690                 }
 691                 pt_succ_return(regs, 0);
 692                 return;
 693         }
 694 
 695         case PTRACE_WRITETEXT:
 696         case PTRACE_WRITEDATA: {
 697                 unsigned char *src = (unsigned char *) addr2;
 698                 unsigned long dest = addr;
 699                 int res, len = data;
 700 
 701                 res = verify_area(VERIFY_READ, (void *) src, len);
 702                 if(res) {
 703                         pt_error_return(regs, -res);
 704                         return;
 705                 }
 706                 while(len) {
 707                         res = write_byte(child, dest, *src);
 708                         if(res < 0) {
 709                                 pt_error_return(regs, -res);
 710                                 return;
 711                         }
 712                         src++; dest++; len--;
 713                 }
 714                 pt_succ_return(regs, 0);
 715                 return;
 716         }
 717 
 718         case PTRACE_SYSCALL: /* continue and stop at (return from) syscall */
 719                 data = 0;
 720                 addr = 1;
 721 
 722         case PTRACE_CONT: { /* restart after signal. */
 723                 if ((unsigned long) data > NSIG) {
 724                         pt_error_return(regs, EIO);
 725                         return;
 726                 }
 727                 if (request == PTRACE_SYSCALL)
 728                         child->flags |= PF_TRACESYS;
 729                 else
 730                         child->flags &= ~PF_TRACESYS;
 731                 child->exit_code = data;
 732                 if((addr != 1) & !(addr & 3)) {
 733                         child->tss.kregs->pc = addr;
 734                         child->tss.kregs->npc = addr + 4;
 735                 }
 736                 wake_up_process(child);
 737                 pt_succ_return(regs, 0);
 738                 return;
 739         }
 740 
 741 /*
 742  * make the child exit.  Best I can do is send it a sigkill. 
 743  * perhaps it should be put in the status that it wants to 
 744  * exit.
 745  */
 746         case PTRACE_KILL: {
 747                 if (child->state == TASK_ZOMBIE) {      /* already dead */
 748                         pt_succ_return(regs, 0);
 749                         return;
 750                 }
 751                 wake_up_process(child);
 752                 child->exit_code = SIGKILL;
 753                 pt_succ_return(regs, 0);
 754                 return;
 755         }
 756 
 757         case PTRACE_SUNDETACH: { /* detach a process that was attached. */
 758                 if ((unsigned long) data > NSIG) {
 759                         pt_error_return(regs, EIO);
 760                         return;
 761                 }
 762                 child->flags &= ~(PF_PTRACED|PF_TRACESYS);
 763                 wake_up_process(child);
 764                 child->exit_code = data;
 765                 REMOVE_LINKS(child);
 766                 child->p_pptr = child->p_opptr;
 767                 SET_LINKS(child);
 768                 pt_succ_return(regs, 0);
 769                 return;
 770         }
 771 
 772         /* PTRACE_DUMPCORE unsupported... */
 773 
 774         default:
 775                 pt_error_return(regs, EIO);
 776                 return;
 777         }
 778 }
 779 
 780 asmlinkage void syscall_trace(void)
     /*  */
 781 {
 782 #ifdef DEBUG_PTRACE
 783         printk("%s [%d]: syscall_trace\n", current->comm, current->pid);
 784 #endif
 785         if ((current->flags & (PF_PTRACED|PF_TRACESYS))
 786                         != (PF_PTRACED|PF_TRACESYS))
 787                 return;
 788         current->exit_code = SIGTRAP;
 789         current->state = TASK_STOPPED;
 790         current->tss.flags ^= 0x80000000;
 791         notify_parent(current);
 792         schedule();
 793         /*
 794          * this isn't the same as continuing with a signal, but it will do
 795          * for normal use.  strace only continues with a signal if the
 796          * stopping signal is not SIGTRAP.  -brl
 797          */
 798         if (current->exit_code)
 799                 current->signal |= (1 << (current->exit_code - 1));
 800         current->exit_code = 0;
 801 }
/* */
root/arch/sparc/kernel/ptrace.c

DEFINITIONS
