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/sysproto.h>
  43 #include <sys/proc.h>
  44 #include <sys/vnode.h>
  45 #include <sys/ptrace.h>
  46 #include <sys/sx.h>
  47 #include <sys/malloc.h>
  48 #include <sys/signalvar.h>
  49
  50 #include <machine/reg.h>
  51
  52 #include <security/audit/audit.h>
  53
  54 #include <vm/vm.h>
  55 #include <vm/pmap.h>
  56 #include <vm/vm_extern.h>
  57 #include <vm/vm_map.h>
  58 #include <vm/vm_kern.h>
  59 #include <vm/vm_object.h>
  60 #include <vm/vm_page.h>
  61
  62 #ifdef COMPAT_IA32
  63 #include <sys/procfs.h>
  64 #include <machine/fpu.h>
  65 #include <compat/ia32/ia32_reg.h>
  66
  67 extern struct sysentvec ia32_freebsd_sysvec;
  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                         error = EFAULT;
 275                         break;
 276                 }
 277
 278                 /*
 279                  * Now we need to get the page.  out_entry, out_prot, wired,
 280                  * and single_use aren't used.  One would think the vm code
 281                  * would be a *bit* nicer...  We use tmap because
 282                  * vm_map_lookup() can change the map argument.
 283                  */
 284                 tmap = map;
 285                 error = vm_map_lookup(&tmap, pageno, reqprot, &out_entry,
 286                     &object, &pindex, &out_prot, &wired);
 287                 if (error) {
 288                         error = EFAULT;
 289                         break;
 290                 }
 291                 VM_OBJECT_LOCK(object);
 292                 while ((m = vm_page_lookup(object, pindex)) == NULL &&
 293                     !writing &&
 294                     (backing_object = object->backing_object) != NULL) {
 295                         /*
 296                          * Allow fallback to backing objects if we are reading.
 297                          */
 298                         VM_OBJECT_LOCK(backing_object);
 299                         pindex += OFF_TO_IDX(object->backing_object_offset);
 300                         VM_OBJECT_UNLOCK(object);
 301                         object = backing_object;
 302                 }
 303                 VM_OBJECT_UNLOCK(object);
 304                 if (m == NULL) {
 305                         vm_map_lookup_done(tmap, out_entry);
 306                         error = EFAULT;
 307                         break;
 308                 }
 309
 310                 /*
 311                  * Hold the page in memory.
 312                  */
 313                 vm_page_lock_queues();
 314                 vm_page_hold(m);
 315                 vm_page_unlock_queues();
 316
 317                 /*
 318                  * We're done with tmap now.
 319                  */
 320                 vm_map_lookup_done(tmap, out_entry);
 321
 322                 /*
 323                  * Now do the i/o move.
 324                  */
 325                 error = uiomove_fromphys(&m, page_offset, len, uio);
 326
 327                 /*
 328                  * Release the page.
 329                  */
 330                 vm_page_lock_queues();
 331                 vm_page_unhold(m);
 332                 vm_page_unlock_queues();
 333
 334         } while (error == 0 && uio->uio_resid > 0);
 335
 336         return (error);
 337 }
 338
 339 /*
 340  * Process debugging system call.
 341  */
 342 #ifndef _SYS_SYSPROTO_H_
 343 struct ptrace_args {
 344         int     req;
 345         pid_t   pid;
 346         caddr_t addr;
 347         int     data;
 348 };
 349 #endif
 350
 351 #ifdef COMPAT_IA32
 352 /*
 353  * This CPP subterfuge is to try and reduce the number of ifdefs in
 354  * the body of the code.
 355  *   COPYIN(uap->addr, &r.reg, sizeof r.reg);
 356  * becomes either:
 357  *   copyin(uap->addr, &r.reg, sizeof r.reg);
 358  * or
 359  *   copyin(uap->addr, &r.reg32, sizeof r.reg32);
 360  * .. except this is done at runtime.
 361  */
 362 #define COPYIN(u, k, s)         wrap32 ? \
 363         copyin(u, k ## 32, s ## 32) : \
 364         copyin(u, k, s)
 365 #define COPYOUT(k, u, s)        wrap32 ? \
 366         copyout(k ## 32, u, s ## 32) : \
 367         copyout(k, u, s)
 368 #else
 369 #define COPYIN(u, k, s)         copyin(u, k, s)
 370 #define COPYOUT(k, u, s)        copyout(k, u, s)
 371 #endif
 372 int
 373 ptrace(struct thread *td, struct ptrace_args *uap)
 374 {
 375         /*
 376          * XXX this obfuscation is to reduce stack usage, but the register
 377          * structs may be too large to put on the stack anyway.
 378          */
 379         union {
 380                 struct ptrace_io_desc piod;
 381                 struct ptrace_lwpinfo pl;
 382                 struct dbreg dbreg;
 383                 struct fpreg fpreg;
 384                 struct reg reg;
 385 #ifdef COMPAT_IA32
 386                 struct dbreg32 dbreg32;
 387                 struct fpreg32 fpreg32;
 388                 struct reg32 reg32;
 389                 struct ptrace_io_desc32 piod32;
 390 #endif
 391         } r;
 392         void *addr;
 393         int error = 0;
 394 #ifdef COMPAT_IA32
 395         int wrap32 = 0;
 396
 397         if (td->td_proc->p_sysent == &ia32_freebsd_sysvec)
 398                 wrap32 = 1;
 399 #endif
 400         AUDIT_ARG(pid, uap->pid);
 401         AUDIT_ARG(cmd, uap->req);
 402         AUDIT_ARG(addr, uap->addr);
 403         AUDIT_ARG(value, uap->data);
 404         addr = &r;
 405         switch (uap->req) {
 406         case PT_GETREGS:
 407         case PT_GETFPREGS:
 408         case PT_GETDBREGS:
 409         case PT_LWPINFO:
 410                 break;
 411         case PT_SETREGS:
 412                 error = COPYIN(uap->addr, &r.reg, sizeof r.reg);
 413                 break;
 414         case PT_SETFPREGS:
 415                 error = COPYIN(uap->addr, &r.fpreg, sizeof r.fpreg);
 416                 break;
 417         case PT_SETDBREGS:
 418                 error = COPYIN(uap->addr, &r.dbreg, sizeof r.dbreg);
 419                 break;
 420         case PT_IO:
 421                 error = COPYIN(uap->addr, &r.piod, sizeof r.piod);
 422                 break;
 423         default:
 424                 addr = uap->addr;
 425                 break;
 426         }
 427         if (error)
 428                 return (error);
 429
 430         error = kern_ptrace(td, uap->req, uap->pid, addr, uap->data);
 431         if (error)
 432                 return (error);
 433
 434         switch (uap->req) {
 435         case PT_IO:
 436                 error = COPYOUT(&r.piod, uap->addr, sizeof r.piod);
 437                 break;
 438         case PT_GETREGS:
 439                 error = COPYOUT(&r.reg, uap->addr, sizeof r.reg);
 440                 break;
 441         case PT_GETFPREGS:
 442                 error = COPYOUT(&r.fpreg, uap->addr, sizeof r.fpreg);
 443                 break;
 444         case PT_GETDBREGS:
 445                 error = COPYOUT(&r.dbreg, uap->addr, sizeof r.dbreg);
 446                 break;
 447         case PT_LWPINFO:
 448                 error = copyout(&r.pl, uap->addr, uap->data);
 449                 break;
 450         }
 451
 452         return (error);
 453 }
 454 #undef COPYIN
 455 #undef COPYOUT
 456
 457 #ifdef COMPAT_IA32
 458 /*
 459  *   PROC_READ(regs, td2, addr);
 460  * becomes either:
 461  *   proc_read_regs(td2, addr);
 462  * or
 463  *   proc_read_regs32(td2, addr);
 464  * .. except this is done at runtime.  There is an additional
 465  * complication in that PROC_WRITE disallows 32 bit consumers
 466  * from writing to 64 bit address space targets.
 467  */
 468 #define PROC_READ(w, t, a)      wrap32 ? \
 469         proc_read_ ## w ## 32(t, a) : \
 470         proc_read_ ## w (t, a)
 471 #define PROC_WRITE(w, t, a)     wrap32 ? \
 472         (safe ? proc_write_ ## w ## 32(t, a) : EINVAL ) : \
 473         proc_write_ ## w (t, a)
 474 #else
 475 #define PROC_READ(w, t, a)      proc_read_ ## w (t, a)
 476 #define PROC_WRITE(w, t, a)     proc_write_ ## w (t, a)
 477 #endif
 478
 479 int
 480 kern_ptrace(struct thread *td, int req, pid_t pid, void *addr, int data)
 481 {
 482         struct iovec iov;
 483         struct uio uio;
 484         struct proc *curp, *p, *pp;
 485         struct thread *td2 = NULL;
 486         struct ptrace_io_desc *piod = NULL;
 487         struct ptrace_lwpinfo *pl;
 488         int error, write, tmp, num;
 489         int proctree_locked = 0;
 490         lwpid_t tid = 0, *buf;
 491 #ifdef COMPAT_IA32
 492         int wrap32 = 0, safe = 0;
 493         struct ptrace_io_desc32 *piod32 = NULL;
 494 #endif
 495
 496         curp = td->td_proc;
 497
 498         /* Lock proctree before locking the process. */
 499         switch (req) {
 500         case PT_TRACE_ME:
 501         case PT_ATTACH:
 502         case PT_STEP:
 503         case PT_CONTINUE:
 504         case PT_TO_SCE:
 505         case PT_TO_SCX:
 506         case PT_SYSCALL:
 507         case PT_DETACH:
 508                 sx_xlock(&proctree_lock);
 509                 proctree_locked = 1;
 510                 break;
 511         default:
 512                 break;
 513         }
 514
 515         write = 0;
 516         if (req == PT_TRACE_ME) {
 517                 p = td->td_proc;
 518                 PROC_LOCK(p);
 519         } else {
 520                 if (pid <= PID_MAX) {
 521                         if ((p = pfind(pid)) == NULL) {
 522                                 if (proctree_locked)
 523                                         sx_xunlock(&proctree_lock);
 524                                 return (ESRCH);
 525                         }
 526                 } else {
 527                         /* this is slow, should be optimized */
 528                         sx_slock(&allproc_lock);
 529                         FOREACH_PROC_IN_SYSTEM(p) {
 530                                 PROC_LOCK(p);
 531                                 FOREACH_THREAD_IN_PROC(p, td2) {
 532                                         if (td2->td_tid == pid)
 533                                                 break;
 534                                 }
 535                                 if (td2 != NULL)
 536                                         break; /* proc lock held */
 537                                 PROC_UNLOCK(p);
 538                         }
 539                         sx_sunlock(&allproc_lock);
 540                         if (p == NULL) {
 541                                 if (proctree_locked)
 542                                         sx_xunlock(&proctree_lock);
 543                                 return (ESRCH);
 544                         }
 545                         tid = pid;
 546                         pid = p->p_pid;
 547                 }
 548         }
 549         AUDIT_ARG(process, p);
 550
 551         if ((p->p_flag & P_WEXIT) != 0) {
 552                 error = ESRCH;
 553                 goto fail;
 554         }
 555         if ((error = p_cansee(td, p)) != 0)
 556                 goto fail;
 557
 558         if ((error = p_candebug(td, p)) != 0)
 559                 goto fail;
 560
 561         /*
 562          * System processes can't be debugged.
 563          */
 564         if ((p->p_flag & P_SYSTEM) != 0) {
 565                 error = EINVAL;
 566                 goto fail;
 567         }
 568
 569         if (tid == 0) {
 570                 if ((p->p_flag & P_STOPPED_TRACE) != 0) {
 571                         KASSERT(p->p_xthread != NULL, ("NULL p_xthread"));
 572                         td2 = p->p_xthread;
 573                 } else {
 574                         td2 = FIRST_THREAD_IN_PROC(p);
 575                 }
 576                 tid = td2->td_tid;
 577         }
 578
 579 #ifdef COMPAT_IA32
 580         /*
 581          * Test if we're a 32 bit client and what the target is.
 582          * Set the wrap controls accordingly.
 583          */
 584         if (td->td_proc->p_sysent == &ia32_freebsd_sysvec) {
 585                 if (td2->td_proc->p_sysent == &ia32_freebsd_sysvec)
 586                         safe = 1;
 587                 wrap32 = 1;
 588         }
 589 #endif
 590         /*
 591          * Permissions check
 592          */
 593         switch (req) {
 594         case PT_TRACE_ME:
 595                 /* Always legal. */
 596                 break;
 597
 598         case PT_ATTACH:
 599                 /* Self */
 600                 if (p->p_pid == td->td_proc->p_pid) {
 601                         error = EINVAL;
 602                         goto fail;
 603                 }
 604
 605                 /* Already traced */
 606                 if (p->p_flag & P_TRACED) {
 607                         error = EBUSY;
 608                         goto fail;
 609                 }
 610
 611                 /* Can't trace an ancestor if you're being traced. */
 612                 if (curp->p_flag & P_TRACED) {
 613                         for (pp = curp->p_pptr; pp != NULL; pp = pp->p_pptr) {
 614                                 if (pp == p) {
 615                                         error = EINVAL;
 616                                         goto fail;
 617                                 }
 618                         }
 619                 }
 620
 621
 622                 /* OK */
 623                 break;
 624
 625         case PT_CLEARSTEP:
 626                 /* Allow thread to clear single step for itself */
 627                 if (td->td_tid == tid)
 628                         break;
 629
 630                 /* FALLTHROUGH */
 631         default:
 632                 /* not being traced... */
 633                 if ((p->p_flag & P_TRACED) == 0) {
 634                         error = EPERM;
 635                         goto fail;
 636                 }
 637
 638                 /* not being traced by YOU */
 639                 if (p->p_pptr != td->td_proc) {
 640                         error = EBUSY;
 641                         goto fail;
 642                 }
 643
 644                 /* not currently stopped */
 645                 if ((p->p_flag & (P_STOPPED_SIG | P_STOPPED_TRACE)) == 0 ||
 646                     p->p_suspcount != p->p_numthreads  ||
 647                     (p->p_flag & P_WAITED) == 0) {
 648                         error = EBUSY;
 649                         goto fail;
 650                 }
 651
 652                 if ((p->p_flag & P_STOPPED_TRACE) == 0) {
 653                         static int count = 0;
 654                         if (count++ == 0)
 655                                 printf("P_STOPPED_TRACE not set.\n");
 656                 }
 657
 658                 /* OK */
 659                 break;
 660         }
 661
 662         /* Keep this process around until we finish this request. */
 663         _PHOLD(p);
 664
 665 #ifdef FIX_SSTEP
 666         /*
 667          * Single step fixup ala procfs
 668          */
 669         FIX_SSTEP(td2);
 670 #endif
 671
 672         /*
 673          * Actually do the requests
 674          */
 675
 676         td->td_retval[0] = 0;
 677
 678         switch (req) {
 679         case PT_TRACE_ME:
 680                 /* set my trace flag and "owner" so it can read/write me */
 681                 p->p_flag |= P_TRACED;
 682                 p->p_oppid = p->p_pptr->p_pid;
 683                 break;
 684
 685         case PT_ATTACH:
 686                 /* security check done above */
 687                 p->p_flag |= P_TRACED;
 688                 p->p_oppid = p->p_pptr->p_pid;
 689                 if (p->p_pptr != td->td_proc)
 690                         proc_reparent(p, td->td_proc);
 691                 data = SIGSTOP;
 692                 goto sendsig;   /* in PT_CONTINUE below */
 693
 694         case PT_CLEARSTEP:
 695                 error = ptrace_clear_single_step(td2);
 696                 break;
 697
 698         case PT_SETSTEP:
 699                 error = ptrace_single_step(td2);
 700                 break;
 701
 702         case PT_SUSPEND:
 703                 td2->td_dbgflags |= TDB_SUSPEND;
 704                 thread_lock(td2);
 705                 td2->td_flags |= TDF_NEEDSUSPCHK;
 706                 thread_unlock(td2);
 707                 break;
 708
 709         case PT_RESUME:
 710                 td2->td_dbgflags &= ~TDB_SUSPEND;
 711                 break;
 712
 713         case PT_STEP:
 714         case PT_CONTINUE:
 715         case PT_TO_SCE:
 716         case PT_TO_SCX:
 717         case PT_SYSCALL:
 718         case PT_DETACH:
 719                 /* Zero means do not send any signal */
 720                 if (data < 0 || data > _SIG_MAXSIG) {
 721                         error = EINVAL;
 722                         break;
 723                 }
 724
 725                 switch (req) {
 726                 case PT_STEP:
 727                         error = ptrace_single_step(td2);
 728                         if (error)
 729                                 goto out;
 730                         break;
 731                 case PT_TO_SCE:
 732                         p->p_stops |= S_PT_SCE;
 733                         break;
 734                 case PT_TO_SCX:
 735                         p->p_stops |= S_PT_SCX;
 736                         break;
 737                 case PT_SYSCALL:
 738                         p->p_stops |= S_PT_SCE | S_PT_SCX;
 739                         break;
 740                 }
 741
 742                 if (addr != (void *)1) {
 743                         error = ptrace_set_pc(td2, (u_long)(uintfptr_t)addr);
 744                         if (error)
 745                                 break;
 746                 }
 747
 748                 if (req == PT_DETACH) {
 749                         /* reset process parent */
 750                         if (p->p_oppid != p->p_pptr->p_pid) {
 751                                 struct proc *pp;
 752
 753                                 PROC_LOCK(p->p_pptr);
 754                                 sigqueue_take(p->p_ksi);
 755                                 PROC_UNLOCK(p->p_pptr);
 756
 757                                 PROC_UNLOCK(p);
 758                                 pp = pfind(p->p_oppid);
 759                                 if (pp == NULL)
 760                                         pp = initproc;
 761                                 else
 762                                         PROC_UNLOCK(pp);
 763                                 PROC_LOCK(p);
 764                                 proc_reparent(p, pp);
 765                                 if (pp == initproc)
 766                                         p->p_sigparent = SIGCHLD;
 767                         }
 768                         p->p_flag &= ~(P_TRACED | P_WAITED);
 769                         p->p_oppid = 0;
 770
 771                         /* should we send SIGCHLD? */
 772                         /* childproc_continued(p); */
 773                 }
 774
 775         sendsig:
 776                 if (proctree_locked) {
 777                         sx_xunlock(&proctree_lock);
 778                         proctree_locked = 0;
 779                 }
 780                 p->p_xstat = data;
 781                 p->p_xthread = NULL;
 782                 if ((p->p_flag & (P_STOPPED_SIG | P_STOPPED_TRACE)) != 0) {
 783                         /* deliver or queue signal */
 784                         td2->td_dbgflags &= ~TDB_XSIG;
 785                         td2->td_xsig = data;
 786
 787                         if (req == PT_DETACH) {
 788                                 struct thread *td3;
 789                                 FOREACH_THREAD_IN_PROC(p, td3) {
 790                                         td3->td_dbgflags &= ~TDB_SUSPEND;
 791                                 }
 792                         }
 793                         /*
 794                          * unsuspend all threads, to not let a thread run,
 795                          * you should use PT_SUSPEND to suspend it before
 796                          * continuing process.
 797                          */
 798                         PROC_SLOCK(p);
 799                         p->p_flag &= ~(P_STOPPED_TRACE|P_STOPPED_SIG|P_WAITED);
 800                         thread_unsuspend(p);
 801                         PROC_SUNLOCK(p);
 802                 } else {
 803                         if (data)
 804                                 psignal(p, data);
 805                 }
 806                 break;
 807
 808         case PT_WRITE_I:
 809         case PT_WRITE_D:
 810                 write = 1;
 811                 /* FALLTHROUGH */
 812         case PT_READ_I:
 813         case PT_READ_D:
 814                 PROC_UNLOCK(p);
 815                 tmp = 0;
 816                 /* write = 0 set above */
 817                 iov.iov_base = write ? (caddr_t)&data : (caddr_t)&tmp;
 818                 iov.iov_len = sizeof(int);
 819                 uio.uio_iov = &iov;
 820                 uio.uio_iovcnt = 1;
 821                 uio.uio_offset = (off_t)(uintptr_t)addr;
 822                 uio.uio_resid = sizeof(int);
 823                 uio.uio_segflg = UIO_SYSSPACE;  /* i.e.: the uap */
 824                 uio.uio_rw = write ? UIO_WRITE : UIO_READ;
 825                 uio.uio_td = td;
 826                 error = proc_rwmem(p, &uio);
 827                 if (uio.uio_resid != 0) {
 828                         /*
 829                          * XXX proc_rwmem() doesn't currently return ENOSPC,
 830                          * so I think write() can bogusly return 0.
 831                          * XXX what happens for short writes?  We don't want
 832                          * to write partial data.
 833                          * XXX proc_rwmem() returns EPERM for other invalid
 834                          * addresses.  Convert this to EINVAL.  Does this
 835                          * clobber returns of EPERM for other reasons?
 836                          */
 837                         if (error == 0 || error == ENOSPC || error == EPERM)
 838                                 error = EINVAL; /* EOF */
 839                 }
 840                 if (!write)
 841                         td->td_retval[0] = tmp;
 842                 PROC_LOCK(p);
 843                 break;
 844
 845         case PT_IO:
 846 #ifdef COMPAT_IA32
 847                 if (wrap32) {
 848                         piod32 = addr;
 849                         iov.iov_base = (void *)(uintptr_t)piod32->piod_addr;
 850                         iov.iov_len = piod32->piod_len;
 851                         uio.uio_offset = (off_t)(uintptr_t)piod32->piod_offs;
 852                         uio.uio_resid = piod32->piod_len;
 853                 } else
 854 #endif
 855                 {
 856                         piod = addr;
 857                         iov.iov_base = piod->piod_addr;
 858                         iov.iov_len = piod->piod_len;
 859                         uio.uio_offset = (off_t)(uintptr_t)piod->piod_offs;
 860                         uio.uio_resid = piod->piod_len;
 861                 }
 862                 uio.uio_iov = &iov;
 863                 uio.uio_iovcnt = 1;
 864                 uio.uio_segflg = UIO_USERSPACE;
 865                 uio.uio_td = td;
 866 #ifdef COMPAT_IA32
 867                 tmp = wrap32 ? piod32->piod_op : piod->piod_op;
 868 #else
 869                 tmp = piod->piod_op;
 870 #endif
 871                 switch (tmp) {
 872                 case PIOD_READ_D:
 873                 case PIOD_READ_I:
 874                         uio.uio_rw = UIO_READ;
 875                         break;
 876                 case PIOD_WRITE_D:
 877                 case PIOD_WRITE_I:
 878                         uio.uio_rw = UIO_WRITE;
 879                         break;
 880                 default:
 881                         error = EINVAL;
 882                         goto out;
 883                 }
 884                 PROC_UNLOCK(p);
 885                 error = proc_rwmem(p, &uio);
 886 #ifdef COMPAT_IA32
 887                 if (wrap32)
 888                         piod32->piod_len -= uio.uio_resid;
 889                 else
 890 #endif
 891                         piod->piod_len -= uio.uio_resid;
 892                 PROC_LOCK(p);
 893                 break;
 894
 895         case PT_KILL:
 896                 data = SIGKILL;
 897                 goto sendsig;   /* in PT_CONTINUE above */
 898
 899         case PT_SETREGS:
 900                 error = PROC_WRITE(regs, td2, addr);
 901                 break;
 902
 903         case PT_GETREGS:
 904                 error = PROC_READ(regs, td2, addr);
 905                 break;
 906
 907         case PT_SETFPREGS:
 908                 error = PROC_WRITE(fpregs, td2, addr);
 909                 break;
 910
 911         case PT_GETFPREGS:
 912                 error = PROC_READ(fpregs, td2, addr);
 913                 break;
 914
 915         case PT_SETDBREGS:
 916                 error = PROC_WRITE(dbregs, td2, addr);
 917                 break;
 918
 919         case PT_GETDBREGS:
 920                 error = PROC_READ(dbregs, td2, addr);
 921                 break;
 922
 923         case PT_LWPINFO:
 924                 if (data <= 0 || data > sizeof(*pl)) {
 925                         error = EINVAL;
 926                         break;
 927                 }
 928                 pl = addr;
 929                 pl->pl_lwpid = td2->td_tid;
 930                 if (td2->td_dbgflags & TDB_XSIG)
 931                         pl->pl_event = PL_EVENT_SIGNAL;
 932                 else
 933                         pl->pl_event = 0;
 934                 pl->pl_flags = 0;
 935                 pl->pl_sigmask = td2->td_sigmask;
 936                 pl->pl_siglist = td2->td_siglist;
 937                 break;
 938
 939         case PT_GETNUMLWPS:
 940                 td->td_retval[0] = p->p_numthreads;
 941                 break;
 942
 943         case PT_GETLWPLIST:
 944                 if (data <= 0) {
 945                         error = EINVAL;
 946                         break;
 947                 }
 948                 num = imin(p->p_numthreads, data);
 949                 PROC_UNLOCK(p);
 950                 buf = malloc(num * sizeof(lwpid_t), M_TEMP, M_WAITOK);
 951                 tmp = 0;
 952                 PROC_LOCK(p);
 953                 FOREACH_THREAD_IN_PROC(p, td2) {
 954                         if (tmp >= num)
 955                                 break;
 956                         buf[tmp++] = td2->td_tid;
 957                 }
 958                 PROC_UNLOCK(p);
 959                 error = copyout(buf, addr, tmp * sizeof(lwpid_t));
 960                 free(buf, M_TEMP);
 961                 if (!error)
 962                         td->td_retval[0] = tmp;
 963                 PROC_LOCK(p);
 964                 break;
 965
 966         default:
 967 #ifdef __HAVE_PTRACE_MACHDEP
 968                 if (req >= PT_FIRSTMACH) {
 969                         PROC_UNLOCK(p);
 970                         error = cpu_ptrace(td2, req, addr, data);
 971                         PROC_LOCK(p);
 972                 } else
 973 #endif
 974                         /* Unknown request. */
 975                         error = EINVAL;
 976                 break;
 977         }
 978
 979 out:
 980         /* Drop our hold on this process now that the request has completed. */
 981         _PRELE(p);
 982 fail:
 983         PROC_UNLOCK(p);
 984         if (proctree_locked)
 985                 sx_xunlock(&proctree_lock);
 986         return (error);
 987 }
 988 #undef PROC_READ
 989 #undef PROC_WRITE
 990
 991 /*
 992  * Stop a process because of a debugging event;
 993  * stay stopped until p->p_step is cleared
 994  * (cleared by PIOCCONT in procfs).
 995  */
 996 void
 997 stopevent(struct proc *p, unsigned int event, unsigned int val)
 998 {
 999
1000         PROC_LOCK_ASSERT(p, MA_OWNED);
1001         p->p_step = 1;
1002         do {
1003                 p->p_xstat = val;
1004                 p->p_xthread = NULL;
1005                 p->p_stype = event;     /* Which event caused the stop? */
1006                 wakeup(&p->p_stype);    /* Wake up any PIOCWAIT'ing procs */
1007                 msleep(&p->p_step, &p->p_mtx, PWAIT, "stopevent", 0);
1008         } while (p->p_step);
1009 }