sys/kern/sys_process.c

   1 /*-
   2  * Copyright (c) 1994, Sean Eric Fagan
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by Sean Eric Fagan.
  16  * 4. The name of the author may not be used to endorse or promote products
  17  *    derived from this software without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 #include <sys/cdefs.h>
  33 __FBSDID("$FreeBSD$");
  34
  35 #include "opt_compat.h"
  36
  37 #include <sys/param.h>
  38 #include <sys/systm.h>
  39 #include <sys/lock.h>
  40 #include <sys/mutex.h>
  41 #include <sys/syscallsubr.h>
  42 #include <sys/sysent.h>
  43 #include <sys/sysproto.h>
  44 #include <sys/proc.h>
  45 #include <sys/vnode.h>
  46 #include <sys/ptrace.h>
  47 #include <sys/sx.h>
  48 #include <sys/malloc.h>
  49 #include <sys/signalvar.h>
  50
  51 #include <machine/reg.h>
  52
  53 #include <security/audit/audit.h>
  54
  55 #include <vm/vm.h>
  56 #include <vm/pmap.h>
  57 #include <vm/vm_extern.h>
  58 #include <vm/vm_map.h>
  59 #include <vm/vm_kern.h>
  60 #include <vm/vm_object.h>
  61 #include <vm/vm_page.h>
  62 #include <vm/vm_param.h>
  63
  64 #ifdef COMPAT_IA32
  65 #include <sys/procfs.h>
  66 #include <machine/fpu.h>
  67 #include <compat/ia32/ia32_reg.h>
  68
  69 struct ptrace_io_desc32 {
  70         int             piod_op;
  71         u_int32_t       piod_offs;
  72         u_int32_t       piod_addr;
  73         u_int32_t       piod_len;
  74 };
  75 #endif
  76
  77 /*
  78  * Functions implemented using PROC_ACTION():
  79  *
  80  * proc_read_regs(proc, regs)
  81  *      Get the current user-visible register set from the process
  82  *      and copy it into the regs structure (<machine/reg.h>).
  83  *      The process is stopped at the time read_regs is called.
  84  *
  85  * proc_write_regs(proc, regs)
  86  *      Update the current register set from the passed in regs
  87  *      structure.  Take care to avoid clobbering special CPU
  88  *      registers or privileged bits in the PSL.
  89  *      Depending on the architecture this may have fix-up work to do,
  90  *      especially if the IAR or PCW are modified.
  91  *      The process is stopped at the time write_regs is called.
  92  *
  93  * proc_read_fpregs, proc_write_fpregs
  94  *      deal with the floating point register set, otherwise as above.
  95  *
  96  * proc_read_dbregs, proc_write_dbregs
  97  *      deal with the processor debug register set, otherwise as above.
  98  *
  99  * proc_sstep(proc)
 100  *      Arrange for the process to trap after executing a single instruction.
 101  */
 102
 103 #define PROC_ACTION(action) do {                                        \
 104         int error;                                                      \
 105                                                                         \
 106         PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);                        \
 107         if ((td->td_proc->p_flag & P_INMEM) == 0)                       \
 108                 error = EIO;                                            \
 109         else                                                            \
 110                 error = (action);                                       \
 111         return (error);                                                 \
 112 } while(0)
 113
 114 int
 115 proc_read_regs(struct thread *td, struct reg *regs)
 116 {
 117
 118         PROC_ACTION(fill_regs(td, regs));
 119 }
 120
 121 int
 122 proc_write_regs(struct thread *td, struct reg *regs)
 123 {
 124
 125         PROC_ACTION(set_regs(td, regs));
 126 }
 127
 128 int
 129 proc_read_dbregs(struct thread *td, struct dbreg *dbregs)
 130 {
 131
 132         PROC_ACTION(fill_dbregs(td, dbregs));
 133 }
 134
 135 int
 136 proc_write_dbregs(struct thread *td, struct dbreg *dbregs)
 137 {
 138
 139         PROC_ACTION(set_dbregs(td, dbregs));
 140 }
 141
 142 /*
 143  * Ptrace doesn't support fpregs at all, and there are no security holes
 144  * or translations for fpregs, so we can just copy them.
 145  */
 146 int
 147 proc_read_fpregs(struct thread *td, struct fpreg *fpregs)
 148 {
 149
 150         PROC_ACTION(fill_fpregs(td, fpregs));
 151 }
 152
 153 int
 154 proc_write_fpregs(struct thread *td, struct fpreg *fpregs)
 155 {
 156
 157         PROC_ACTION(set_fpregs(td, fpregs));
 158 }
 159
 160 #ifdef COMPAT_IA32
 161 /* For 32 bit binaries, we need to expose the 32 bit regs layouts. */
 162 int
 163 proc_read_regs32(struct thread *td, struct reg32 *regs32)
 164 {
 165
 166         PROC_ACTION(fill_regs32(td, regs32));
 167 }
 168
 169 int
 170 proc_write_regs32(struct thread *td, struct reg32 *regs32)
 171 {
 172
 173         PROC_ACTION(set_regs32(td, regs32));
 174 }
 175
 176 int
 177 proc_read_dbregs32(struct thread *td, struct dbreg32 *dbregs32)
 178 {
 179
 180         PROC_ACTION(fill_dbregs32(td, dbregs32));
 181 }
 182
 183 int
 184 proc_write_dbregs32(struct thread *td, struct dbreg32 *dbregs32)
 185 {
 186
 187         PROC_ACTION(set_dbregs32(td, dbregs32));
 188 }
 189
 190 int
 191 proc_read_fpregs32(struct thread *td, struct fpreg32 *fpregs32)
 192 {
 193
 194         PROC_ACTION(fill_fpregs32(td, fpregs32));
 195 }
 196
 197 int
 198 proc_write_fpregs32(struct thread *td, struct fpreg32 *fpregs32)
 199 {
 200
 201         PROC_ACTION(set_fpregs32(td, fpregs32));
 202 }
 203 #endif
 204
 205 int
 206 proc_sstep(struct thread *td)
 207 {
 208
 209         PROC_ACTION(ptrace_single_step(td));
 210 }
 211
 212 int
 213 proc_rwmem(struct proc *p, struct uio *uio)
 214 {
 215         vm_map_t map;
 216         vm_object_t backing_object, object = NULL;
 217         vm_offset_t pageno = 0;         /* page number */
 218         vm_prot_t reqprot;
 219         int error, fault_flags, writing;
 220
 221         /*
 222          * Assert that someone has locked this vmspace.  (Should be
 223          * curthread but we can't assert that.)  This keeps the process
 224          * from exiting out from under us until this operation completes.
 225          */
 226         KASSERT(p->p_lock >= 1, ("%s: process %p (pid %d) not held", __func__,
 227             p, p->p_pid));
 228
 229         /*
 230          * The map we want...
 231          */
 232         map = &p->p_vmspace->vm_map;
 233
 234         writing = uio->uio_rw == UIO_WRITE;
 235         reqprot = writing ? (VM_PROT_WRITE | VM_PROT_OVERRIDE_WRITE) :
 236             VM_PROT_READ;
 237         fault_flags = writing ? VM_FAULT_DIRTY : VM_FAULT_NORMAL;
 238
 239         /*
 240          * Only map in one page at a time.  We don't have to, but it
 241          * makes things easier.  This way is trivial - right?
 242          */
 243         do {
 244                 vm_map_t tmap;
 245                 vm_offset_t uva;
 246                 int page_offset;                /* offset into page */
 247                 vm_map_entry_t out_entry;
 248                 vm_prot_t out_prot;
 249                 boolean_t wired;
 250                 vm_pindex_t pindex;
 251                 u_int len;
 252                 vm_page_t m;
 253
 254                 object = NULL;
 255
 256                 uva = (vm_offset_t)uio->uio_offset;
 257
 258                 /*
 259                  * Get the page number of this segment.
 260                  */
 261                 pageno = trunc_page(uva);
 262                 page_offset = uva - pageno;
 263
 264                 /*
 265                  * How many bytes to copy
 266                  */
 267                 len = min(PAGE_SIZE - page_offset, uio->uio_resid);
 268
 269                 /*
 270                  * Fault the page on behalf of the process
 271                  */
 272                 error = vm_fault(map, pageno, reqprot, fault_flags);
 273                 if (error) {
 274                         if (error == KERN_RESOURCE_SHORTAGE)
 275                                 error = ENOMEM;
 276                         else
 277                                 error = EFAULT;
 278                         break;
 279                 }
 280
 281                 /*
 282                  * Now we need to get the page.  out_entry, out_prot, wired,
 283                  * and single_use aren't used.  One would think the vm code
 284                  * would be a *bit* nicer...  We use tmap because
 285                  * vm_map_lookup() can change the map argument.
 286                  */
 287                 tmap = map;
 288                 error = vm_map_lookup(&tmap, pageno, reqprot, &out_entry,
 289                     &object, &pindex, &out_prot, &wired);
 290                 if (error) {
 291                         error = EFAULT;
 292                         break;
 293                 }
 294                 VM_OBJECT_LOCK(object);
 295                 while ((m = vm_page_lookup(object, pindex)) == NULL &&
 296                     !writing &&
 297                     (backing_object = object->backing_object) != NULL) {
 298                         /*
 299                          * Allow fallback to backing objects if we are reading.
 300                          */
 301                         VM_OBJECT_LOCK(backing_object);
 302                         pindex += OFF_TO_IDX(object->backing_object_offset);
 303                         VM_OBJECT_UNLOCK(object);
 304                         object = backing_object;
 305                 }
 306                 VM_OBJECT_UNLOCK(object);
 307                 if (m == NULL) {
 308                         vm_map_lookup_done(tmap, out_entry);
 309                         error = EFAULT;
 310                         break;
 311                 }
 312
 313                 /*
 314                  * Hold the page in memory.
 315                  */
 316                 vm_page_lock_queues();
 317                 vm_page_hold(m);
 318                 vm_page_unlock_queues();
 319
 320                 /*
 321                  * We're done with tmap now.
 322                  */
 323                 vm_map_lookup_done(tmap, out_entry);
 324
 325                 /*
 326                  * Now do the i/o move.
 327                  */
 328                 error = uiomove_fromphys(&m, page_offset, len, uio);
 329
 330                 /*
 331                  * Release the page.
 332                  */
 333                 vm_page_lock_queues();
 334                 vm_page_unhold(m);
 335                 vm_page_unlock_queues();
 336
 337         } while (error == 0 && uio->uio_resid > 0);
 338
 339         return (error);
 340 }
 341
 342 /*
 343  * Process debugging system call.
 344  */
 345 #ifndef _SYS_SYSPROTO_H_
 346 struct ptrace_args {
 347         int     req;
 348         pid_t   pid;
 349         caddr_t addr;
 350         int     data;
 351 };
 352 #endif
 353
 354 #ifdef COMPAT_IA32
 355 /*
 356  * This CPP subterfuge is to try and reduce the number of ifdefs in
 357  * the body of the code.
 358  *   COPYIN(uap->addr, &r.reg, sizeof r.reg);
 359  * becomes either:
 360  *   copyin(uap->addr, &r.reg, sizeof r.reg);
 361  * or
 362  *   copyin(uap->addr, &r.reg32, sizeof r.reg32);
 363  * .. except this is done at runtime.
 364  */
 365 #define COPYIN(u, k, s)         wrap32 ? \
 366         copyin(u, k ## 32, s ## 32) : \
 367         copyin(u, k, s)
 368 #define COPYOUT(k, u, s)        wrap32 ? \
 369         copyout(k ## 32, u, s ## 32) : \
 370         copyout(k, u, s)
 371 #else
 372 #define COPYIN(u, k, s)         copyin(u, k, s)
 373 #define COPYOUT(k, u, s)        copyout(k, u, s)
 374 #endif
 375 int
 376 ptrace(struct thread *td, struct ptrace_args *uap)
 377 {
 378         /*
 379          * XXX this obfuscation is to reduce stack usage, but the register
 380          * structs may be too large to put on the stack anyway.
 381          */
 382         union {
 383                 struct ptrace_io_desc piod;
 384                 struct ptrace_lwpinfo pl;
 385                 struct dbreg dbreg;
 386                 struct fpreg fpreg;
 387                 struct reg reg;
 388 #ifdef COMPAT_IA32
 389                 struct dbreg32 dbreg32;
 390                 struct fpreg32 fpreg32;
 391                 struct reg32 reg32;
 392                 struct ptrace_io_desc32 piod32;
 393 #endif
 394         } r;
 395         void *addr;
 396         int error = 0;
 397 #ifdef COMPAT_IA32
 398         int wrap32 = 0;
 399
 400         if (SV_CURPROC_FLAG(SV_ILP32))
 401                 wrap32 = 1;
 402 #endif
 403         AUDIT_ARG_PID(uap->pid);
 404         AUDIT_ARG_CMD(uap->req);
 405         AUDIT_ARG_VALUE(uap->data);
 406         addr = &r;
 407         switch (uap->req) {
 408         case PT_GETREGS:
 409         case PT_GETFPREGS:
 410         case PT_GETDBREGS:
 411         case PT_LWPINFO:
 412                 break;
 413         case PT_SETREGS:
 414                 error = COPYIN(uap->addr, &r.reg, sizeof r.reg);
 415                 break;
 416         case PT_SETFPREGS:
 417                 error = COPYIN(uap->addr, &r.fpreg, sizeof r.fpreg);
 418                 break;
 419         case PT_SETDBREGS:
 420                 error = COPYIN(uap->addr, &r.dbreg, sizeof r.dbreg);
 421                 break;
 422         case PT_IO:
 423                 error = COPYIN(uap->addr, &r.piod, sizeof r.piod);
 424                 break;
 425         default:
 426                 addr = uap->addr;
 427                 break;
 428         }
 429         if (error)
 430                 return (error);
 431
 432         error = kern_ptrace(td, uap->req, uap->pid, addr, uap->data);
 433         if (error)
 434                 return (error);
 435
 436         switch (uap->req) {
 437         case PT_IO:
 438                 error = COPYOUT(&r.piod, uap->addr, sizeof r.piod);
 439                 break;
 440         case PT_GETREGS:
 441                 error = COPYOUT(&r.reg, uap->addr, sizeof r.reg);
 442                 break;
 443         case PT_GETFPREGS:
 444                 error = COPYOUT(&r.fpreg, uap->addr, sizeof r.fpreg);
 445                 break;
 446         case PT_GETDBREGS:
 447                 error = COPYOUT(&r.dbreg, uap->addr, sizeof r.dbreg);
 448                 break;
 449         case PT_LWPINFO:
 450                 error = copyout(&r.pl, uap->addr, uap->data);
 451                 break;
 452         }
 453
 454         return (error);
 455 }
 456 #undef COPYIN
 457 #undef COPYOUT
 458
 459 #ifdef COMPAT_IA32
 460 /*
 461  *   PROC_READ(regs, td2, addr);
 462  * becomes either:
 463  *   proc_read_regs(td2, addr);
 464  * or
 465  *   proc_read_regs32(td2, addr);
 466  * .. except this is done at runtime.  There is an additional
 467  * complication in that PROC_WRITE disallows 32 bit consumers
 468  * from writing to 64 bit address space targets.
 469  */
 470 #define PROC_READ(w, t, a)      wrap32 ? \
 471         proc_read_ ## w ## 32(t, a) : \
 472         proc_read_ ## w (t, a)
 473 #define PROC_WRITE(w, t, a)     wrap32 ? \
 474         (safe ? proc_write_ ## w ## 32(t, a) : EINVAL ) : \
 475         proc_write_ ## w (t, a)
 476 #else
 477 #define PROC_READ(w, t, a)      proc_read_ ## w (t, a)
 478 #define PROC_WRITE(w, t, a)     proc_write_ ## w (t, a)
 479 #endif
 480
 481 int
 482 kern_ptrace(struct thread *td, int req, pid_t pid, void *addr, int data)
 483 {
 484         struct iovec iov;
 485         struct uio uio;
 486         struct proc *curp, *p, *pp;
 487         struct thread *td2 = NULL;
 488         struct ptrace_io_desc *piod = NULL;
 489         struct ptrace_lwpinfo *pl;
 490         int error, write, tmp, num;
 491         int proctree_locked = 0;
 492         lwpid_t tid = 0, *buf;
 493 #ifdef COMPAT_IA32
 494         int wrap32 = 0, safe = 0;
 495         struct ptrace_io_desc32 *piod32 = NULL;
 496 #endif
 497
 498         curp = td->td_proc;
 499
 500         /* Lock proctree before locking the process. */
 501         switch (req) {
 502         case PT_TRACE_ME:
 503         case PT_ATTACH:
 504         case PT_STEP:
 505         case PT_CONTINUE:
 506         case PT_TO_SCE:
 507         case PT_TO_SCX:
 508         case PT_SYSCALL:
 509         case PT_DETACH:
 510                 sx_xlock(&proctree_lock);
 511                 proctree_locked = 1;
 512                 break;
 513         default:
 514                 break;
 515         }
 516
 517         write = 0;
 518         if (req == PT_TRACE_ME) {
 519                 p = td->td_proc;
 520                 PROC_LOCK(p);
 521         } else {
 522                 if (pid <= PID_MAX) {
 523                         if ((p = pfind(pid)) == NULL) {
 524                                 if (proctree_locked)
 525                                         sx_xunlock(&proctree_lock);
 526                                 return (ESRCH);
 527                         }
 528                 } else {
 529                         /* this is slow, should be optimized */
 530                         sx_slock(&allproc_lock);
 531                         FOREACH_PROC_IN_SYSTEM(p) {
 532                                 PROC_LOCK(p);
 533                                 FOREACH_THREAD_IN_PROC(p, td2) {
 534                                         if (td2->td_tid == pid)
 535                                                 break;
 536                                 }
 537                                 if (td2 != NULL)
 538                                         break; /* proc lock held */
 539                                 PROC_UNLOCK(p);
 540                         }
 541                         sx_sunlock(&allproc_lock);
 542                         if (p == NULL) {
 543                                 if (proctree_locked)
 544                                         sx_xunlock(&proctree_lock);
 545                                 return (ESRCH);
 546                         }
 547                         tid = pid;
 548                         pid = p->p_pid;
 549                 }
 550         }
 551         AUDIT_ARG_PROCESS(p);
 552
 553         if ((p->p_flag & P_WEXIT) != 0) {
 554                 error = ESRCH;
 555                 goto fail;
 556         }
 557         if ((error = p_cansee(td, p)) != 0)
 558                 goto fail;
 559
 560         if ((error = p_candebug(td, p)) != 0)
 561                 goto fail;
 562
 563         /*
 564          * System processes can't be debugged.
 565          */
 566         if ((p->p_flag & P_SYSTEM) != 0) {
 567                 error = EINVAL;
 568                 goto fail;
 569         }
 570
 571         if (tid == 0) {
 572                 if ((p->p_flag & P_STOPPED_TRACE) != 0) {
 573                         KASSERT(p->p_xthread != NULL, ("NULL p_xthread"));
 574                         td2 = p->p_xthread;
 575                 } else {
 576                         td2 = FIRST_THREAD_IN_PROC(p);
 577                 }
 578                 tid = td2->td_tid;
 579         }
 580
 581 #ifdef COMPAT_IA32
 582         /*
 583          * Test if we're a 32 bit client and what the target is.
 584          * Set the wrap controls accordingly.
 585          */
 586         if (SV_CURPROC_FLAG(SV_ILP32)) {
 587                 if (td2->td_proc->p_sysent->sv_flags & SV_ILP32)
 588                         safe = 1;
 589                 wrap32 = 1;
 590         }
 591 #endif
 592         /*
 593          * Permissions check
 594          */
 595         switch (req) {
 596         case PT_TRACE_ME:
 597                 /* Always legal. */
 598                 break;
 599
 600         case PT_ATTACH:
 601                 /* Self */
 602                 if (p->p_pid == td->td_proc->p_pid) {
 603                         error = EINVAL;
 604                         goto fail;
 605                 }
 606
 607                 /* Already traced */
 608                 if (p->p_flag & P_TRACED) {
 609                         error = EBUSY;
 610                         goto fail;
 611                 }
 612
 613                 /* Can't trace an ancestor if you're being traced. */
 614                 if (curp->p_flag & P_TRACED) {
 615                         for (pp = curp->p_pptr; pp != NULL; pp = pp->p_pptr) {
 616                                 if (pp == p) {
 617                                         error = EINVAL;
 618                                         goto fail;
 619                                 }
 620                         }
 621                 }
 622
 623
 624                 /* OK */
 625                 break;
 626
 627         case PT_CLEARSTEP:
 628                 /* Allow thread to clear single step for itself */
 629                 if (td->td_tid == tid)
 630                         break;
 631
 632                 /* FALLTHROUGH */
 633         default:
 634                 /* not being traced... */
 635                 if ((p->p_flag & P_TRACED) == 0) {
 636                         error = EPERM;
 637                         goto fail;
 638                 }
 639
 640                 /* not being traced by YOU */
 641                 if (p->p_pptr != td->td_proc) {
 642                         error = EBUSY;
 643                         goto fail;
 644                 }
 645
 646                 /* not currently stopped */
 647                 if ((p->p_flag & (P_STOPPED_SIG | P_STOPPED_TRACE)) == 0 ||
 648                     p->p_suspcount != p->p_numthreads  ||
 649                     (p->p_flag & P_WAITED) == 0) {
 650                         error = EBUSY;
 651                         goto fail;
 652                 }
 653
 654                 if ((p->p_flag & P_STOPPED_TRACE) == 0) {
 655                         static int count = 0;
 656                         if (count++ == 0)
 657                                 printf("P_STOPPED_TRACE not set.\n");
 658                 }
 659
 660                 /* OK */
 661                 break;
 662         }
 663
 664         /* Keep this process around until we finish this request. */
 665         _PHOLD(p);
 666
 667 #ifdef FIX_SSTEP
 668         /*
 669          * Single step fixup ala procfs
 670          */
 671         FIX_SSTEP(td2);
 672 #endif
 673
 674         /*
 675          * Actually do the requests
 676          */
 677
 678         td->td_retval[0] = 0;
 679
 680         switch (req) {
 681         case PT_TRACE_ME:
 682                 /* set my trace flag and "owner" so it can read/write me */
 683                 p->p_flag |= P_TRACED;
 684                 p->p_oppid = p->p_pptr->p_pid;
 685                 break;
 686
 687         case PT_ATTACH:
 688                 /* security check done above */
 689                 p->p_flag |= P_TRACED;
 690                 p->p_oppid = p->p_pptr->p_pid;
 691                 if (p->p_pptr != td->td_proc)
 692                         proc_reparent(p, td->td_proc);
 693                 data = SIGSTOP;
 694                 goto sendsig;   /* in PT_CONTINUE below */
 695
 696         case PT_CLEARSTEP:
 697                 error = ptrace_clear_single_step(td2);
 698                 break;
 699
 700         case PT_SETSTEP:
 701                 error = ptrace_single_step(td2);
 702                 break;
 703
 704         case PT_SUSPEND:
 705                 td2->td_dbgflags |= TDB_SUSPEND;
 706                 thread_lock(td2);
 707                 td2->td_flags |= TDF_NEEDSUSPCHK;
 708                 thread_unlock(td2);
 709                 break;
 710
 711         case PT_RESUME:
 712                 td2->td_dbgflags &= ~TDB_SUSPEND;
 713                 break;
 714
 715         case PT_STEP:
 716         case PT_CONTINUE:
 717         case PT_TO_SCE:
 718         case PT_TO_SCX:
 719         case PT_SYSCALL:
 720         case PT_DETACH:
 721                 /* Zero means do not send any signal */
 722                 if (data < 0 || data > _SIG_MAXSIG) {
 723                         error = EINVAL;
 724                         break;
 725                 }
 726
 727                 switch (req) {
 728                 case PT_STEP:
 729                         error = ptrace_single_step(td2);
 730                         if (error)
 731                                 goto out;
 732                         break;
 733                 case PT_TO_SCE:
 734                         p->p_stops |= S_PT_SCE;
 735                         break;
 736                 case PT_TO_SCX:
 737                         p->p_stops |= S_PT_SCX;
 738                         break;
 739                 case PT_SYSCALL:
 740                         p->p_stops |= S_PT_SCE | S_PT_SCX;
 741                         break;
 742                 }
 743
 744                 if (addr != (void *)1) {
 745                         error = ptrace_set_pc(td2, (u_long)(uintfptr_t)addr);
 746                         if (error)
 747                                 break;
 748                 }
 749
 750                 if (req == PT_DETACH) {
 751                         /* reset process parent */
 752                         if (p->p_oppid != p->p_pptr->p_pid) {
 753                                 struct proc *pp;
 754
 755                                 PROC_LOCK(p->p_pptr);
 756                                 sigqueue_take(p->p_ksi);
 757                                 PROC_UNLOCK(p->p_pptr);
 758
 759                                 PROC_UNLOCK(p);
 760                                 pp = pfind(p->p_oppid);
 761                                 if (pp == NULL)
 762                                         pp = initproc;
 763                                 else
 764                                         PROC_UNLOCK(pp);
 765                                 PROC_LOCK(p);
 766                                 proc_reparent(p, pp);
 767                                 if (pp == initproc)
 768                                         p->p_sigparent = SIGCHLD;
 769                         }
 770                         p->p_flag &= ~(P_TRACED | P_WAITED);
 771                         p->p_oppid = 0;
 772
 773                         /* should we send SIGCHLD? */
 774                         /* childproc_continued(p); */
 775                 }
 776
 777         sendsig:
 778                 if (proctree_locked) {
 779                         sx_xunlock(&proctree_lock);
 780                         proctree_locked = 0;
 781                 }
 782                 p->p_xstat = data;
 783                 p->p_xthread = NULL;
 784                 if ((p->p_flag & (P_STOPPED_SIG | P_STOPPED_TRACE)) != 0) {
 785                         /* deliver or queue signal */
 786                         td2->td_dbgflags &= ~TDB_XSIG;
 787                         td2->td_xsig = data;
 788
 789                         if (req == PT_DETACH) {
 790                                 struct thread *td3;
 791                                 FOREACH_THREAD_IN_PROC(p, td3) {
 792                                         td3->td_dbgflags &= ~TDB_SUSPEND;
 793                                 }
 794                         }
 795                         /*
 796                          * unsuspend all threads, to not let a thread run,
 797                          * you should use PT_SUSPEND to suspend it before
 798                          * continuing process.
 799                          */
 800                         PROC_SLOCK(p);
 801                         p->p_flag &= ~(P_STOPPED_TRACE|P_STOPPED_SIG|P_WAITED);
 802                         thread_unsuspend(p);
 803                         PROC_SUNLOCK(p);
 804                 } else {
 805                         if (data)
 806                                 psignal(p, data);
 807                 }
 808                 break;
 809
 810         case PT_WRITE_I:
 811         case PT_WRITE_D:
 812                 write = 1;
 813                 /* FALLTHROUGH */
 814         case PT_READ_I:
 815         case PT_READ_D:
 816                 PROC_UNLOCK(p);
 817                 tmp = 0;
 818                 /* write = 0 set above */
 819                 iov.iov_base = write ? (caddr_t)&data : (caddr_t)&tmp;
 820                 iov.iov_len = sizeof(int);
 821                 uio.uio_iov = &iov;
 822                 uio.uio_iovcnt = 1;
 823                 uio.uio_offset = (off_t)(uintptr_t)addr;
 824                 uio.uio_resid = sizeof(int);
 825                 uio.uio_segflg = UIO_SYSSPACE;  /* i.e.: the uap */
 826                 uio.uio_rw = write ? UIO_WRITE : UIO_READ;
 827                 uio.uio_td = td;
 828                 error = proc_rwmem(p, &uio);
 829                 if (uio.uio_resid != 0) {
 830                         /*
 831                          * XXX proc_rwmem() doesn't currently return ENOSPC,
 832                          * so I think write() can bogusly return 0.
 833                          * XXX what happens for short writes?  We don't want
 834                          * to write partial data.
 835                          * XXX proc_rwmem() returns EPERM for other invalid
 836                          * addresses.  Convert this to EINVAL.  Does this
 837                          * clobber returns of EPERM for other reasons?
 838                          */
 839                         if (error == 0 || error == ENOSPC || error == EPERM)
 840                                 error = EINVAL; /* EOF */
 841                 }
 842                 if (!write)
 843                         td->td_retval[0] = tmp;
 844                 PROC_LOCK(p);
 845                 break;
 846
 847         case PT_IO:
 848 #ifdef COMPAT_IA32
 849                 if (wrap32) {
 850                         piod32 = addr;
 851                         iov.iov_base = (void *)(uintptr_t)piod32->piod_addr;
 852                         iov.iov_len = piod32->piod_len;
 853                         uio.uio_offset = (off_t)(uintptr_t)piod32->piod_offs;
 854                         uio.uio_resid = piod32->piod_len;
 855                 } else
 856 #endif
 857                 {
 858                         piod = addr;
 859                         iov.iov_base = piod->piod_addr;
 860                         iov.iov_len = piod->piod_len;
 861                         uio.uio_offset = (off_t)(uintptr_t)piod->piod_offs;
 862                         uio.uio_resid = piod->piod_len;
 863                 }
 864                 uio.uio_iov = &iov;
 865                 uio.uio_iovcnt = 1;
 866                 uio.uio_segflg = UIO_USERSPACE;
 867                 uio.uio_td = td;
 868 #ifdef COMPAT_IA32
 869                 tmp = wrap32 ? piod32->piod_op : piod->piod_op;
 870 #else
 871                 tmp = piod->piod_op;
 872 #endif
 873                 switch (tmp) {
 874                 case PIOD_READ_D:
 875                 case PIOD_READ_I:
 876                         uio.uio_rw = UIO_READ;
 877                         break;
 878                 case PIOD_WRITE_D:
 879                 case PIOD_WRITE_I:
 880                         uio.uio_rw = UIO_WRITE;
 881                         break;
 882                 default:
 883                         error = EINVAL;
 884                         goto out;
 885                 }
 886                 PROC_UNLOCK(p);
 887                 error = proc_rwmem(p, &uio);
 888 #ifdef COMPAT_IA32
 889                 if (wrap32)
 890                         piod32->piod_len -= uio.uio_resid;
 891                 else
 892 #endif
 893                         piod->piod_len -= uio.uio_resid;
 894                 PROC_LOCK(p);
 895                 break;
 896
 897         case PT_KILL:
 898                 data = SIGKILL;
 899                 goto sendsig;   /* in PT_CONTINUE above */
 900
 901         case PT_SETREGS:
 902                 error = PROC_WRITE(regs, td2, addr);
 903                 break;
 904
 905         case PT_GETREGS:
 906                 error = PROC_READ(regs, td2, addr);
 907                 break;
 908
 909         case PT_SETFPREGS:
 910                 error = PROC_WRITE(fpregs, td2, addr);
 911                 break;
 912
 913         case PT_GETFPREGS:
 914                 error = PROC_READ(fpregs, td2, addr);
 915                 break;
 916
 917         case PT_SETDBREGS:
 918                 error = PROC_WRITE(dbregs, td2, addr);
 919                 break;
 920
 921         case PT_GETDBREGS:
 922                 error = PROC_READ(dbregs, td2, addr);
 923                 break;
 924
 925         case PT_LWPINFO:
 926                 if (data <= 0 || data > sizeof(*pl)) {
 927                         error = EINVAL;
 928                         break;
 929                 }
 930                 pl = addr;
 931                 pl->pl_lwpid = td2->td_tid;
 932                 if (td2->td_dbgflags & TDB_XSIG)
 933                         pl->pl_event = PL_EVENT_SIGNAL;
 934                 else
 935                         pl->pl_event = 0;
 936                 pl->pl_flags = 0;
 937                 pl->pl_sigmask = td2->td_sigmask;
 938                 pl->pl_siglist = td2->td_siglist;
 939                 break;
 940
 941         case PT_GETNUMLWPS:
 942                 td->td_retval[0] = p->p_numthreads;
 943                 break;
 944
 945         case PT_GETLWPLIST:
 946                 if (data <= 0) {
 947                         error = EINVAL;
 948                         break;
 949                 }
 950                 num = imin(p->p_numthreads, data);
 951                 PROC_UNLOCK(p);
 952                 buf = malloc(num * sizeof(lwpid_t), M_TEMP, M_WAITOK);
 953                 tmp = 0;
 954                 PROC_LOCK(p);
 955                 FOREACH_THREAD_IN_PROC(p, td2) {
 956                         if (tmp >= num)
 957                                 break;
 958                         buf[tmp++] = td2->td_tid;
 959                 }
 960                 PROC_UNLOCK(p);
 961                 error = copyout(buf, addr, tmp * sizeof(lwpid_t));
 962                 free(buf, M_TEMP);
 963                 if (!error)
 964                         td->td_retval[0] = tmp;
 965                 PROC_LOCK(p);
 966                 break;
 967
 968         default:
 969 #ifdef __HAVE_PTRACE_MACHDEP
 970                 if (req >= PT_FIRSTMACH) {
 971                         PROC_UNLOCK(p);
 972                         error = cpu_ptrace(td2, req, addr, data);
 973                         PROC_LOCK(p);
 974                 } else
 975 #endif
 976                         /* Unknown request. */
 977                         error = EINVAL;
 978                 break;
 979         }
 980
 981 out:
 982         /* Drop our hold on this process now that the request has completed. */
 983         _PRELE(p);
 984 fail:
 985         PROC_UNLOCK(p);
 986         if (proctree_locked)
 987                 sx_xunlock(&proctree_lock);
 988         return (error);
 989 }
 990 #undef PROC_READ
 991 #undef PROC_WRITE
 992
 993 /*
 994  * Stop a process because of a debugging event;
 995  * stay stopped until p->p_step is cleared
 996  * (cleared by PIOCCONT in procfs).
 997  */
 998 void
 999 stopevent(struct proc *p, unsigned int event, unsigned int val)
1000 {
1001
1002         PROC_LOCK_ASSERT(p, MA_OWNED);
1003         p->p_step = 1;
1004         do {
1005                 p->p_xstat = val;
1006                 p->p_xthread = NULL;
1007                 p->p_stype = event;     /* Which event caused the stop? */
1008                 wakeup(&p->p_stype);    /* Wake up any PIOCWAIT'ing procs */
1009                 msleep(&p->p_step, &p->p_mtx, PWAIT, "stopevent", 0);
1010         } while (p->p_step);
1011 }