sys/kern/sys_process.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-4-Clause
   3  *
   4  * Copyright (c) 1994, Sean Eric Fagan
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. All advertising materials mentioning features or use of this software
  16  *    must display the following acknowledgement:
  17  *      This product includes software developed by Sean Eric Fagan.
  18  * 4. The name of the author may not be used to endorse or promote products
  19  *    derived from this software without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #include <sys/cdefs.h>
  35 __FBSDID("$FreeBSD$");
  36
  37 #include <sys/param.h>
  38 #include <sys/systm.h>
  39 #include <sys/ktr.h>
  40 #include <sys/limits.h>
  41 #include <sys/lock.h>
  42 #include <sys/mutex.h>
  43 #include <sys/reg.h>
  44 #include <sys/syscallsubr.h>
  45 #include <sys/sysent.h>
  46 #include <sys/sysproto.h>
  47 #include <sys/priv.h>
  48 #include <sys/proc.h>
  49 #include <sys/vnode.h>
  50 #include <sys/ptrace.h>
  51 #include <sys/rwlock.h>
  52 #include <sys/sx.h>
  53 #include <sys/malloc.h>
  54 #include <sys/signalvar.h>
  55 #include <sys/caprights.h>
  56 #include <sys/filedesc.h>
  57
  58 #include <security/audit/audit.h>
  59
  60 #include <vm/vm.h>
  61 #include <vm/pmap.h>
  62 #include <vm/vm_extern.h>
  63 #include <vm/vm_map.h>
  64 #include <vm/vm_kern.h>
  65 #include <vm/vm_object.h>
  66 #include <vm/vm_page.h>
  67 #include <vm/vm_param.h>
  68
  69 #ifdef COMPAT_FREEBSD32
  70 #include <sys/procfs.h>
  71 #endif
  72
  73 /*
  74  * Functions implemented using PROC_ACTION():
  75  *
  76  * proc_read_regs(proc, regs)
  77  *      Get the current user-visible register set from the process
  78  *      and copy it into the regs structure (<machine/reg.h>).
  79  *      The process is stopped at the time read_regs is called.
  80  *
  81  * proc_write_regs(proc, regs)
  82  *      Update the current register set from the passed in regs
  83  *      structure.  Take care to avoid clobbering special CPU
  84  *      registers or privileged bits in the PSL.
  85  *      Depending on the architecture this may have fix-up work to do,
  86  *      especially if the IAR or PCW are modified.
  87  *      The process is stopped at the time write_regs is called.
  88  *
  89  * proc_read_fpregs, proc_write_fpregs
  90  *      deal with the floating point register set, otherwise as above.
  91  *
  92  * proc_read_dbregs, proc_write_dbregs
  93  *      deal with the processor debug register set, otherwise as above.
  94  *
  95  * proc_sstep(proc)
  96  *      Arrange for the process to trap after executing a single instruction.
  97  */
  98
  99 #define PROC_ACTION(action) do {                                        \
 100         int error;                                                      \
 101                                                                         \
 102         PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);                        \
 103         if ((td->td_proc->p_flag & P_INMEM) == 0)                       \
 104                 error = EIO;                                            \
 105         else                                                            \
 106                 error = (action);                                       \
 107         return (error);                                                 \
 108 } while(0)
 109
 110 int
 111 proc_read_regs(struct thread *td, struct reg *regs)
 112 {
 113
 114         PROC_ACTION(fill_regs(td, regs));
 115 }
 116
 117 int
 118 proc_write_regs(struct thread *td, struct reg *regs)
 119 {
 120
 121         PROC_ACTION(set_regs(td, regs));
 122 }
 123
 124 int
 125 proc_read_dbregs(struct thread *td, struct dbreg *dbregs)
 126 {
 127
 128         PROC_ACTION(fill_dbregs(td, dbregs));
 129 }
 130
 131 int
 132 proc_write_dbregs(struct thread *td, struct dbreg *dbregs)
 133 {
 134
 135         PROC_ACTION(set_dbregs(td, dbregs));
 136 }
 137
 138 /*
 139  * Ptrace doesn't support fpregs at all, and there are no security holes
 140  * or translations for fpregs, so we can just copy them.
 141  */
 142 int
 143 proc_read_fpregs(struct thread *td, struct fpreg *fpregs)
 144 {
 145
 146         PROC_ACTION(fill_fpregs(td, fpregs));
 147 }
 148
 149 int
 150 proc_write_fpregs(struct thread *td, struct fpreg *fpregs)
 151 {
 152
 153         PROC_ACTION(set_fpregs(td, fpregs));
 154 }
 155
 156 #ifdef COMPAT_FREEBSD32
 157 /* For 32 bit binaries, we need to expose the 32 bit regs layouts. */
 158 int
 159 proc_read_regs32(struct thread *td, struct reg32 *regs32)
 160 {
 161
 162         PROC_ACTION(fill_regs32(td, regs32));
 163 }
 164
 165 int
 166 proc_write_regs32(struct thread *td, struct reg32 *regs32)
 167 {
 168
 169         PROC_ACTION(set_regs32(td, regs32));
 170 }
 171
 172 int
 173 proc_read_dbregs32(struct thread *td, struct dbreg32 *dbregs32)
 174 {
 175
 176         PROC_ACTION(fill_dbregs32(td, dbregs32));
 177 }
 178
 179 int
 180 proc_write_dbregs32(struct thread *td, struct dbreg32 *dbregs32)
 181 {
 182
 183         PROC_ACTION(set_dbregs32(td, dbregs32));
 184 }
 185
 186 int
 187 proc_read_fpregs32(struct thread *td, struct fpreg32 *fpregs32)
 188 {
 189
 190         PROC_ACTION(fill_fpregs32(td, fpregs32));
 191 }
 192
 193 int
 194 proc_write_fpregs32(struct thread *td, struct fpreg32 *fpregs32)
 195 {
 196
 197         PROC_ACTION(set_fpregs32(td, fpregs32));
 198 }
 199 #endif
 200
 201 int
 202 proc_sstep(struct thread *td)
 203 {
 204
 205         PROC_ACTION(ptrace_single_step(td));
 206 }
 207
 208 int
 209 proc_rwmem(struct proc *p, struct uio *uio)
 210 {
 211         vm_map_t map;
 212         vm_offset_t pageno;             /* page number */
 213         vm_prot_t reqprot;
 214         int error, fault_flags, page_offset, writing;
 215
 216         /*
 217          * Make sure that the process' vmspace remains live.
 218          */
 219         if (p != curproc)
 220                 PROC_ASSERT_HELD(p);
 221         PROC_LOCK_ASSERT(p, MA_NOTOWNED);
 222
 223         /*
 224          * The map we want...
 225          */
 226         map = &p->p_vmspace->vm_map;
 227
 228         /*
 229          * If we are writing, then we request vm_fault() to create a private
 230          * copy of each page.  Since these copies will not be writeable by the
 231          * process, we must explicity request that they be dirtied.
 232          */
 233         writing = uio->uio_rw == UIO_WRITE;
 234         reqprot = writing ? VM_PROT_COPY | VM_PROT_READ : VM_PROT_READ;
 235         fault_flags = writing ? VM_FAULT_DIRTY : VM_FAULT_NORMAL;
 236
 237         /*
 238          * Only map in one page at a time.  We don't have to, but it
 239          * makes things easier.  This way is trivial - right?
 240          */
 241         do {
 242                 vm_offset_t uva;
 243                 u_int len;
 244                 vm_page_t m;
 245
 246                 uva = (vm_offset_t)uio->uio_offset;
 247
 248                 /*
 249                  * Get the page number of this segment.
 250                  */
 251                 pageno = trunc_page(uva);
 252                 page_offset = uva - pageno;
 253
 254                 /*
 255                  * How many bytes to copy
 256                  */
 257                 len = min(PAGE_SIZE - page_offset, uio->uio_resid);
 258
 259                 /*
 260                  * Fault and hold the page on behalf of the process.
 261                  */
 262                 error = vm_fault(map, pageno, reqprot, fault_flags, &m);
 263                 if (error != KERN_SUCCESS) {
 264                         if (error == KERN_RESOURCE_SHORTAGE)
 265                                 error = ENOMEM;
 266                         else
 267                                 error = EFAULT;
 268                         break;
 269                 }
 270
 271                 /*
 272                  * Now do the i/o move.
 273                  */
 274                 error = uiomove_fromphys(&m, page_offset, len, uio);
 275
 276                 /* Make the I-cache coherent for breakpoints. */
 277                 if (writing && error == 0) {
 278                         vm_map_lock_read(map);
 279                         if (vm_map_check_protection(map, pageno, pageno +
 280                             PAGE_SIZE, VM_PROT_EXECUTE))
 281                                 vm_sync_icache(map, uva, len);
 282                         vm_map_unlock_read(map);
 283                 }
 284
 285                 /*
 286                  * Release the page.
 287                  */
 288                 vm_page_unwire(m, PQ_ACTIVE);
 289
 290         } while (error == 0 && uio->uio_resid > 0);
 291
 292         return (error);
 293 }
 294
 295 static ssize_t
 296 proc_iop(struct thread *td, struct proc *p, vm_offset_t va, void *buf,
 297     size_t len, enum uio_rw rw)
 298 {
 299         struct iovec iov;
 300         struct uio uio;
 301         ssize_t slen;
 302
 303         MPASS(len < SSIZE_MAX);
 304         slen = (ssize_t)len;
 305
 306         iov.iov_base = (caddr_t)buf;
 307         iov.iov_len = len;
 308         uio.uio_iov = &iov;
 309         uio.uio_iovcnt = 1;
 310         uio.uio_offset = va;
 311         uio.uio_resid = slen;
 312         uio.uio_segflg = UIO_SYSSPACE;
 313         uio.uio_rw = rw;
 314         uio.uio_td = td;
 315         proc_rwmem(p, &uio);
 316         if (uio.uio_resid == slen)
 317                 return (-1);
 318         return (slen - uio.uio_resid);
 319 }
 320
 321 ssize_t
 322 proc_readmem(struct thread *td, struct proc *p, vm_offset_t va, void *buf,
 323     size_t len)
 324 {
 325
 326         return (proc_iop(td, p, va, buf, len, UIO_READ));
 327 }
 328
 329 ssize_t
 330 proc_writemem(struct thread *td, struct proc *p, vm_offset_t va, void *buf,
 331     size_t len)
 332 {
 333
 334         return (proc_iop(td, p, va, buf, len, UIO_WRITE));
 335 }
 336
 337 static int
 338 ptrace_vm_entry(struct thread *td, struct proc *p, struct ptrace_vm_entry *pve)
 339 {
 340         struct vattr vattr;
 341         vm_map_t map;
 342         vm_map_entry_t entry;
 343         vm_object_t obj, tobj, lobj;
 344         struct vmspace *vm;
 345         struct vnode *vp;
 346         char *freepath, *fullpath;
 347         u_int pathlen;
 348         int error, index;
 349
 350         error = 0;
 351         obj = NULL;
 352
 353         vm = vmspace_acquire_ref(p);
 354         map = &vm->vm_map;
 355         vm_map_lock_read(map);
 356
 357         do {
 358                 KASSERT((map->header.eflags & MAP_ENTRY_IS_SUB_MAP) == 0,
 359                     ("Submap in map header"));
 360                 index = 0;
 361                 VM_MAP_ENTRY_FOREACH(entry, map) {
 362                         if (index >= pve->pve_entry &&
 363                             (entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0)
 364                                 break;
 365                         index++;
 366                 }
 367                 if (index < pve->pve_entry) {
 368                         error = EINVAL;
 369                         break;
 370                 }
 371                 if (entry == &map->header) {
 372                         error = ENOENT;
 373                         break;
 374                 }
 375
 376                 /* We got an entry. */
 377                 pve->pve_entry = index + 1;
 378                 pve->pve_timestamp = map->timestamp;
 379                 pve->pve_start = entry->start;
 380                 pve->pve_end = entry->end - 1;
 381                 pve->pve_offset = entry->offset;
 382                 pve->pve_prot = entry->protection;
 383
 384                 /* Backing object's path needed? */
 385                 if (pve->pve_pathlen == 0)
 386                         break;
 387
 388                 pathlen = pve->pve_pathlen;
 389                 pve->pve_pathlen = 0;
 390
 391                 obj = entry->object.vm_object;
 392                 if (obj != NULL)
 393                         VM_OBJECT_RLOCK(obj);
 394         } while (0);
 395
 396         vm_map_unlock_read(map);
 397
 398         pve->pve_fsid = VNOVAL;
 399         pve->pve_fileid = VNOVAL;
 400
 401         if (error == 0 && obj != NULL) {
 402                 lobj = obj;
 403                 for (tobj = obj; tobj != NULL; tobj = tobj->backing_object) {
 404                         if (tobj != obj)
 405                                 VM_OBJECT_RLOCK(tobj);
 406                         if (lobj != obj)
 407                                 VM_OBJECT_RUNLOCK(lobj);
 408                         lobj = tobj;
 409                         pve->pve_offset += tobj->backing_object_offset;
 410                 }
 411                 vp = vm_object_vnode(lobj);
 412                 if (vp != NULL)
 413                         vref(vp);
 414                 if (lobj != obj)
 415                         VM_OBJECT_RUNLOCK(lobj);
 416                 VM_OBJECT_RUNLOCK(obj);
 417
 418                 if (vp != NULL) {
 419                         freepath = NULL;
 420                         fullpath = NULL;
 421                         vn_fullpath(vp, &fullpath, &freepath);
 422                         vn_lock(vp, LK_SHARED | LK_RETRY);
 423                         if (VOP_GETATTR(vp, &vattr, td->td_ucred) == 0) {
 424                                 pve->pve_fileid = vattr.va_fileid;
 425                                 pve->pve_fsid = vattr.va_fsid;
 426                         }
 427                         vput(vp);
 428
 429                         if (fullpath != NULL) {
 430                                 pve->pve_pathlen = strlen(fullpath) + 1;
 431                                 if (pve->pve_pathlen <= pathlen) {
 432                                         error = copyout(fullpath, pve->pve_path,
 433                                             pve->pve_pathlen);
 434                                 } else
 435                                         error = ENAMETOOLONG;
 436                         }
 437                         if (freepath != NULL)
 438                                 free(freepath, M_TEMP);
 439                 }
 440         }
 441         vmspace_free(vm);
 442         if (error == 0)
 443                 CTR3(KTR_PTRACE, "PT_VM_ENTRY: pid %d, entry %d, start %p",
 444                     p->p_pid, pve->pve_entry, pve->pve_start);
 445
 446         return (error);
 447 }
 448
 449 /*
 450  * Process debugging system call.
 451  */
 452 #ifndef _SYS_SYSPROTO_H_
 453 struct ptrace_args {
 454         int     req;
 455         pid_t   pid;
 456         caddr_t addr;
 457         int     data;
 458 };
 459 #endif
 460
 461 int
 462 sys_ptrace(struct thread *td, struct ptrace_args *uap)
 463 {
 464         /*
 465          * XXX this obfuscation is to reduce stack usage, but the register
 466          * structs may be too large to put on the stack anyway.
 467          */
 468         union {
 469                 struct ptrace_io_desc piod;
 470                 struct ptrace_lwpinfo pl;
 471                 struct ptrace_vm_entry pve;
 472                 struct ptrace_coredump pc;
 473                 struct dbreg dbreg;
 474                 struct fpreg fpreg;
 475                 struct reg reg;
 476                 char args[sizeof(td->td_sa.args)];
 477                 struct ptrace_sc_ret psr;
 478                 int ptevents;
 479         } r;
 480         void *addr;
 481         int error;
 482
 483         if (!allow_ptrace)
 484                 return (ENOSYS);
 485         error = 0;
 486
 487         AUDIT_ARG_PID(uap->pid);
 488         AUDIT_ARG_CMD(uap->req);
 489         AUDIT_ARG_VALUE(uap->data);
 490         addr = &r;
 491         switch (uap->req) {
 492         case PT_GET_EVENT_MASK:
 493         case PT_LWPINFO:
 494         case PT_GET_SC_ARGS:
 495         case PT_GET_SC_RET:
 496                 break;
 497         case PT_GETREGS:
 498                 bzero(&r.reg, sizeof(r.reg));
 499                 break;
 500         case PT_GETFPREGS:
 501                 bzero(&r.fpreg, sizeof(r.fpreg));
 502                 break;
 503         case PT_GETDBREGS:
 504                 bzero(&r.dbreg, sizeof(r.dbreg));
 505                 break;
 506         case PT_SETREGS:
 507                 error = copyin(uap->addr, &r.reg, sizeof(r.reg));
 508                 break;
 509         case PT_SETFPREGS:
 510                 error = copyin(uap->addr, &r.fpreg, sizeof(r.fpreg));
 511                 break;
 512         case PT_SETDBREGS:
 513                 error = copyin(uap->addr, &r.dbreg, sizeof(r.dbreg));
 514                 break;
 515         case PT_SET_EVENT_MASK:
 516                 if (uap->data != sizeof(r.ptevents))
 517                         error = EINVAL;
 518                 else
 519                         error = copyin(uap->addr, &r.ptevents, uap->data);
 520                 break;
 521         case PT_IO:
 522                 error = copyin(uap->addr, &r.piod, sizeof(r.piod));
 523                 break;
 524         case PT_VM_ENTRY:
 525                 error = copyin(uap->addr, &r.pve, sizeof(r.pve));
 526                 break;
 527         case PT_COREDUMP:
 528                 if (uap->data != sizeof(r.pc))
 529                         error = EINVAL;
 530                 else
 531                         error = copyin(uap->addr, &r.pc, uap->data);
 532                 break;
 533         default:
 534                 addr = uap->addr;
 535                 break;
 536         }
 537         if (error)
 538                 return (error);
 539
 540         error = kern_ptrace(td, uap->req, uap->pid, addr, uap->data);
 541         if (error)
 542                 return (error);
 543
 544         switch (uap->req) {
 545         case PT_VM_ENTRY:
 546                 error = copyout(&r.pve, uap->addr, sizeof(r.pve));
 547                 break;
 548         case PT_IO:
 549                 error = copyout(&r.piod, uap->addr, sizeof(r.piod));
 550                 break;
 551         case PT_GETREGS:
 552                 error = copyout(&r.reg, uap->addr, sizeof(r.reg));
 553                 break;
 554         case PT_GETFPREGS:
 555                 error = copyout(&r.fpreg, uap->addr, sizeof(r.fpreg));
 556                 break;
 557         case PT_GETDBREGS:
 558                 error = copyout(&r.dbreg, uap->addr, sizeof(r.dbreg));
 559                 break;
 560         case PT_GET_EVENT_MASK:
 561                 /* NB: The size in uap->data is validated in kern_ptrace(). */
 562                 error = copyout(&r.ptevents, uap->addr, uap->data);
 563                 break;
 564         case PT_LWPINFO:
 565                 /* NB: The size in uap->data is validated in kern_ptrace(). */
 566                 error = copyout(&r.pl, uap->addr, uap->data);
 567                 break;
 568         case PT_GET_SC_ARGS:
 569                 error = copyout(r.args, uap->addr, MIN(uap->data,
 570                     sizeof(r.args)));
 571                 break;
 572         case PT_GET_SC_RET:
 573                 error = copyout(&r.psr, uap->addr, MIN(uap->data,
 574                     sizeof(r.psr)));
 575                 break;
 576         }
 577
 578         return (error);
 579 }
 580
 581 #ifdef COMPAT_FREEBSD32
 582 /*
 583  *   PROC_READ(regs, td2, addr);
 584  * becomes either:
 585  *   proc_read_regs(td2, addr);
 586  * or
 587  *   proc_read_regs32(td2, addr);
 588  * .. except this is done at runtime.  There is an additional
 589  * complication in that PROC_WRITE disallows 32 bit consumers
 590  * from writing to 64 bit address space targets.
 591  */
 592 #define PROC_READ(w, t, a)      wrap32 ? \
 593         proc_read_ ## w ## 32(t, a) : \
 594         proc_read_ ## w (t, a)
 595 #define PROC_WRITE(w, t, a)     wrap32 ? \
 596         (safe ? proc_write_ ## w ## 32(t, a) : EINVAL ) : \
 597         proc_write_ ## w (t, a)
 598 #else
 599 #define PROC_READ(w, t, a)      proc_read_ ## w (t, a)
 600 #define PROC_WRITE(w, t, a)     proc_write_ ## w (t, a)
 601 #endif
 602
 603 void
 604 proc_set_traced(struct proc *p, bool stop)
 605 {
 606
 607         sx_assert(&proctree_lock, SX_XLOCKED);
 608         PROC_LOCK_ASSERT(p, MA_OWNED);
 609         p->p_flag |= P_TRACED;
 610         if (stop)
 611                 p->p_flag2 |= P2_PTRACE_FSTP;
 612         p->p_ptevents = PTRACE_DEFAULT;
 613 }
 614
 615 void
 616 ptrace_unsuspend(struct proc *p)
 617 {
 618         PROC_LOCK_ASSERT(p, MA_OWNED);
 619
 620         PROC_SLOCK(p);
 621         p->p_flag &= ~(P_STOPPED_TRACE | P_STOPPED_SIG | P_WAITED);
 622         thread_unsuspend(p);
 623         PROC_SUNLOCK(p);
 624         itimer_proc_continue(p);
 625         kqtimer_proc_continue(p);
 626 }
 627
 628 static int
 629 proc_can_ptrace(struct thread *td, struct proc *p)
 630 {
 631         int error;
 632
 633         PROC_LOCK_ASSERT(p, MA_OWNED);
 634
 635         if ((p->p_flag & P_WEXIT) != 0)
 636                 return (ESRCH);
 637
 638         if ((error = p_cansee(td, p)) != 0)
 639                 return (error);
 640         if ((error = p_candebug(td, p)) != 0)
 641                 return (error);
 642
 643         /* not being traced... */
 644         if ((p->p_flag & P_TRACED) == 0)
 645                 return (EPERM);
 646
 647         /* not being traced by YOU */
 648         if (p->p_pptr != td->td_proc)
 649                 return (EBUSY);
 650
 651         /* not currently stopped */
 652         if ((p->p_flag & P_STOPPED_TRACE) == 0 ||
 653             p->p_suspcount != p->p_numthreads  ||
 654             (p->p_flag & P_WAITED) == 0)
 655                 return (EBUSY);
 656
 657         return (0);
 658 }
 659
 660 static struct thread *
 661 ptrace_sel_coredump_thread(struct proc *p)
 662 {
 663         struct thread *td2;
 664
 665         PROC_LOCK_ASSERT(p, MA_OWNED);
 666         MPASS((p->p_flag & P_STOPPED_TRACE) != 0);
 667
 668         FOREACH_THREAD_IN_PROC(p, td2) {
 669                 if ((td2->td_dbgflags & TDB_SSWITCH) != 0)
 670                         return (td2);
 671         }
 672         return (NULL);
 673 }
 674
 675 int
 676 kern_ptrace(struct thread *td, int req, pid_t pid, void *addr, int data)
 677 {
 678         struct iovec iov;
 679         struct uio uio;
 680         struct proc *curp, *p, *pp;
 681         struct thread *td2 = NULL, *td3;
 682         struct ptrace_io_desc *piod = NULL;
 683         struct ptrace_lwpinfo *pl;
 684         struct ptrace_sc_ret *psr;
 685         struct file *fp;
 686         struct ptrace_coredump *pc;
 687         struct thr_coredump_req *tcq;
 688         int error, num, tmp;
 689         lwpid_t tid = 0, *buf;
 690 #ifdef COMPAT_FREEBSD32
 691         int wrap32 = 0, safe = 0;
 692 #endif
 693         bool proctree_locked, p2_req_set;
 694
 695         curp = td->td_proc;
 696         proctree_locked = false;
 697         p2_req_set = false;
 698
 699         /* Lock proctree before locking the process. */
 700         switch (req) {
 701         case PT_TRACE_ME:
 702         case PT_ATTACH:
 703         case PT_STEP:
 704         case PT_CONTINUE:
 705         case PT_TO_SCE:
 706         case PT_TO_SCX:
 707         case PT_SYSCALL:
 708         case PT_FOLLOW_FORK:
 709         case PT_LWP_EVENTS:
 710         case PT_GET_EVENT_MASK:
 711         case PT_SET_EVENT_MASK:
 712         case PT_DETACH:
 713         case PT_GET_SC_ARGS:
 714                 sx_xlock(&proctree_lock);
 715                 proctree_locked = true;
 716                 break;
 717         default:
 718                 break;
 719         }
 720
 721         if (req == PT_TRACE_ME) {
 722                 p = td->td_proc;
 723                 PROC_LOCK(p);
 724         } else {
 725                 if (pid <= PID_MAX) {
 726                         if ((p = pfind(pid)) == NULL) {
 727                                 if (proctree_locked)
 728                                         sx_xunlock(&proctree_lock);
 729                                 return (ESRCH);
 730                         }
 731                 } else {
 732                         td2 = tdfind(pid, -1);
 733                         if (td2 == NULL) {
 734                                 if (proctree_locked)
 735                                         sx_xunlock(&proctree_lock);
 736                                 return (ESRCH);
 737                         }
 738                         p = td2->td_proc;
 739                         tid = pid;
 740                         pid = p->p_pid;
 741                 }
 742         }
 743         AUDIT_ARG_PROCESS(p);
 744
 745         if ((p->p_flag & P_WEXIT) != 0) {
 746                 error = ESRCH;
 747                 goto fail;
 748         }
 749         if ((error = p_cansee(td, p)) != 0)
 750                 goto fail;
 751
 752         if ((error = p_candebug(td, p)) != 0)
 753                 goto fail;
 754
 755         /*
 756          * System processes can't be debugged.
 757          */
 758         if ((p->p_flag & P_SYSTEM) != 0) {
 759                 error = EINVAL;
 760                 goto fail;
 761         }
 762
 763         if (tid == 0) {
 764                 if ((p->p_flag & P_STOPPED_TRACE) != 0) {
 765                         KASSERT(p->p_xthread != NULL, ("NULL p_xthread"));
 766                         td2 = p->p_xthread;
 767                 } else {
 768                         td2 = FIRST_THREAD_IN_PROC(p);
 769                 }
 770                 tid = td2->td_tid;
 771         }
 772
 773 #ifdef COMPAT_FREEBSD32
 774         /*
 775          * Test if we're a 32 bit client and what the target is.
 776          * Set the wrap controls accordingly.
 777          */
 778         if (SV_CURPROC_FLAG(SV_ILP32)) {
 779                 if (SV_PROC_FLAG(td2->td_proc, SV_ILP32))
 780                         safe = 1;
 781                 wrap32 = 1;
 782         }
 783 #endif
 784         /*
 785          * Permissions check
 786          */
 787         switch (req) {
 788         case PT_TRACE_ME:
 789                 /*
 790                  * Always legal, when there is a parent process which
 791                  * could trace us.  Otherwise, reject.
 792                  */
 793                 if ((p->p_flag & P_TRACED) != 0) {
 794                         error = EBUSY;
 795                         goto fail;
 796                 }
 797                 if (p->p_pptr == initproc) {
 798                         error = EPERM;
 799                         goto fail;
 800                 }
 801                 break;
 802
 803         case PT_ATTACH:
 804                 /* Self */
 805                 if (p == td->td_proc) {
 806                         error = EINVAL;
 807                         goto fail;
 808                 }
 809
 810                 /* Already traced */
 811                 if (p->p_flag & P_TRACED) {
 812                         error = EBUSY;
 813                         goto fail;
 814                 }
 815
 816                 /* Can't trace an ancestor if you're being traced. */
 817                 if (curp->p_flag & P_TRACED) {
 818                         for (pp = curp->p_pptr; pp != NULL; pp = pp->p_pptr) {
 819                                 if (pp == p) {
 820                                         error = EINVAL;
 821                                         goto fail;
 822                                 }
 823                         }
 824                 }
 825
 826                 /* OK */
 827                 break;
 828
 829         case PT_CLEARSTEP:
 830                 /* Allow thread to clear single step for itself */
 831                 if (td->td_tid == tid)
 832                         break;
 833
 834                 /* FALLTHROUGH */
 835         default:
 836                 /*
 837                  * Check for ptrace eligibility before waiting for
 838                  * holds to drain.
 839                  */
 840                 error = proc_can_ptrace(td, p);
 841                 if (error != 0)
 842                         goto fail;
 843
 844                 /*
 845                  * Block parallel ptrace requests.  Most important, do
 846                  * not allow other thread in debugger to continue the
 847                  * debuggee until coredump finished.
 848                  */
 849                 while ((p->p_flag2 & P2_PTRACEREQ) != 0) {
 850                         if (proctree_locked)
 851                                 sx_xunlock(&proctree_lock);
 852                         error = msleep(&p->p_flag2, &p->p_mtx, PPAUSE | PCATCH |
 853                             (proctree_locked ? PDROP : 0), "pptrace", 0);
 854                         if (proctree_locked) {
 855                                 sx_xlock(&proctree_lock);
 856                                 PROC_LOCK(p);
 857                         }
 858                         if (error == 0 && td2->td_proc != p)
 859                                 error = ESRCH;
 860                         if (error == 0)
 861                                 error = proc_can_ptrace(td, p);
 862                         if (error != 0)
 863                                 goto fail;
 864                 }
 865
 866                 /* Ok */
 867                 break;
 868         }
 869
 870         /*
 871          * Keep this process around and request parallel ptrace()
 872          * request to wait until we finish this request.
 873          */
 874         MPASS((p->p_flag2 & P2_PTRACEREQ) == 0);
 875         p->p_flag2 |= P2_PTRACEREQ;
 876         p2_req_set = true;
 877         _PHOLD(p);
 878
 879         /*
 880          * Actually do the requests
 881          */
 882
 883         td->td_retval[0] = 0;
 884
 885         switch (req) {
 886         case PT_TRACE_ME:
 887                 /* set my trace flag and "owner" so it can read/write me */
 888                 proc_set_traced(p, false);
 889                 if (p->p_flag & P_PPWAIT)
 890                         p->p_flag |= P_PPTRACE;
 891                 CTR1(KTR_PTRACE, "PT_TRACE_ME: pid %d", p->p_pid);
 892                 break;
 893
 894         case PT_ATTACH:
 895                 /* security check done above */
 896                 /*
 897                  * It would be nice if the tracing relationship was separate
 898                  * from the parent relationship but that would require
 899                  * another set of links in the proc struct or for "wait"
 900                  * to scan the entire proc table.  To make life easier,
 901                  * we just re-parent the process we're trying to trace.
 902                  * The old parent is remembered so we can put things back
 903                  * on a "detach".
 904                  */
 905                 proc_set_traced(p, true);
 906                 proc_reparent(p, td->td_proc, false);
 907                 CTR2(KTR_PTRACE, "PT_ATTACH: pid %d, oppid %d", p->p_pid,
 908                     p->p_oppid);
 909
 910                 sx_xunlock(&proctree_lock);
 911                 proctree_locked = false;
 912                 MPASS(p->p_xthread == NULL);
 913                 MPASS((p->p_flag & P_STOPPED_TRACE) == 0);
 914
 915                 /*
 916                  * If already stopped due to a stop signal, clear the
 917                  * existing stop before triggering a traced SIGSTOP.
 918                  */
 919                 if ((p->p_flag & P_STOPPED_SIG) != 0) {
 920                         PROC_SLOCK(p);
 921                         p->p_flag &= ~(P_STOPPED_SIG | P_WAITED);
 922                         thread_unsuspend(p);
 923                         PROC_SUNLOCK(p);
 924                 }
 925
 926                 kern_psignal(p, SIGSTOP);
 927                 break;
 928
 929         case PT_CLEARSTEP:
 930                 CTR2(KTR_PTRACE, "PT_CLEARSTEP: tid %d (pid %d)", td2->td_tid,
 931                     p->p_pid);
 932                 error = ptrace_clear_single_step(td2);
 933                 break;
 934
 935         case PT_SETSTEP:
 936                 CTR2(KTR_PTRACE, "PT_SETSTEP: tid %d (pid %d)", td2->td_tid,
 937                     p->p_pid);
 938                 error = ptrace_single_step(td2);
 939                 break;
 940
 941         case PT_SUSPEND:
 942                 CTR2(KTR_PTRACE, "PT_SUSPEND: tid %d (pid %d)", td2->td_tid,
 943                     p->p_pid);
 944                 td2->td_dbgflags |= TDB_SUSPEND;
 945                 thread_lock(td2);
 946                 td2->td_flags |= TDF_NEEDSUSPCHK;
 947                 thread_unlock(td2);
 948                 break;
 949
 950         case PT_RESUME:
 951                 CTR2(KTR_PTRACE, "PT_RESUME: tid %d (pid %d)", td2->td_tid,
 952                     p->p_pid);
 953                 td2->td_dbgflags &= ~TDB_SUSPEND;
 954                 break;
 955
 956         case PT_FOLLOW_FORK:
 957                 CTR3(KTR_PTRACE, "PT_FOLLOW_FORK: pid %d %s -> %s", p->p_pid,
 958                     p->p_ptevents & PTRACE_FORK ? "enabled" : "disabled",
 959                     data ? "enabled" : "disabled");
 960                 if (data)
 961                         p->p_ptevents |= PTRACE_FORK;
 962                 else
 963                         p->p_ptevents &= ~PTRACE_FORK;
 964                 break;
 965
 966         case PT_LWP_EVENTS:
 967                 CTR3(KTR_PTRACE, "PT_LWP_EVENTS: pid %d %s -> %s", p->p_pid,
 968                     p->p_ptevents & PTRACE_LWP ? "enabled" : "disabled",
 969                     data ? "enabled" : "disabled");
 970                 if (data)
 971                         p->p_ptevents |= PTRACE_LWP;
 972                 else
 973                         p->p_ptevents &= ~PTRACE_LWP;
 974                 break;
 975
 976         case PT_GET_EVENT_MASK:
 977                 if (data != sizeof(p->p_ptevents)) {
 978                         error = EINVAL;
 979                         break;
 980                 }
 981                 CTR2(KTR_PTRACE, "PT_GET_EVENT_MASK: pid %d mask %#x", p->p_pid,
 982                     p->p_ptevents);
 983                 *(int *)addr = p->p_ptevents;
 984                 break;
 985
 986         case PT_SET_EVENT_MASK:
 987                 if (data != sizeof(p->p_ptevents)) {
 988                         error = EINVAL;
 989                         break;
 990                 }
 991                 tmp = *(int *)addr;
 992                 if ((tmp & ~(PTRACE_EXEC | PTRACE_SCE | PTRACE_SCX |
 993                     PTRACE_FORK | PTRACE_LWP | PTRACE_VFORK)) != 0) {
 994                         error = EINVAL;
 995                         break;
 996                 }
 997                 CTR3(KTR_PTRACE, "PT_SET_EVENT_MASK: pid %d mask %#x -> %#x",
 998                     p->p_pid, p->p_ptevents, tmp);
 999                 p->p_ptevents = tmp;
1000                 break;
1001
1002         case PT_GET_SC_ARGS:
1003                 CTR1(KTR_PTRACE, "PT_GET_SC_ARGS: pid %d", p->p_pid);
1004                 if ((td2->td_dbgflags & (TDB_SCE | TDB_SCX)) == 0
1005 #ifdef COMPAT_FREEBSD32
1006                     || (wrap32 && !safe)
1007 #endif
1008                     ) {
1009                         error = EINVAL;
1010                         break;
1011                 }
1012                 bzero(addr, sizeof(td2->td_sa.args));
1013                 /* See the explanation in linux_ptrace_get_syscall_info(). */
1014                 bcopy(td2->td_sa.args, addr, SV_PROC_ABI(td->td_proc) ==
1015                     SV_ABI_LINUX ? sizeof(td2->td_sa.args) :
1016                     td2->td_sa.callp->sy_narg * sizeof(register_t));
1017                 break;
1018
1019         case PT_GET_SC_RET:
1020                 if ((td2->td_dbgflags & (TDB_SCX)) == 0
1021 #ifdef COMPAT_FREEBSD32
1022                     || (wrap32 && !safe)
1023 #endif
1024                     ) {
1025                         error = EINVAL;
1026                         break;
1027                 }
1028                 psr = addr;
1029                 bzero(psr, sizeof(*psr));
1030                 psr->sr_error = td2->td_errno;
1031                 if (psr->sr_error == 0) {
1032                         psr->sr_retval[0] = td2->td_retval[0];
1033                         psr->sr_retval[1] = td2->td_retval[1];
1034                 }
1035                 CTR4(KTR_PTRACE,
1036                     "PT_GET_SC_RET: pid %d error %d retval %#lx,%#lx",
1037                     p->p_pid, psr->sr_error, psr->sr_retval[0],
1038                     psr->sr_retval[1]);
1039                 break;
1040
1041         case PT_STEP:
1042         case PT_CONTINUE:
1043         case PT_TO_SCE:
1044         case PT_TO_SCX:
1045         case PT_SYSCALL:
1046         case PT_DETACH:
1047                 /* Zero means do not send any signal */
1048                 if (data < 0 || data > _SIG_MAXSIG) {
1049                         error = EINVAL;
1050                         break;
1051                 }
1052
1053                 switch (req) {
1054                 case PT_STEP:
1055                         CTR3(KTR_PTRACE, "PT_STEP: tid %d (pid %d), sig = %d",
1056                             td2->td_tid, p->p_pid, data);
1057                         error = ptrace_single_step(td2);
1058                         if (error)
1059                                 goto out;
1060                         break;
1061                 case PT_CONTINUE:
1062                 case PT_TO_SCE:
1063                 case PT_TO_SCX:
1064                 case PT_SYSCALL:
1065                         if (addr != (void *)1) {
1066                                 error = ptrace_set_pc(td2,
1067                                     (u_long)(uintfptr_t)addr);
1068                                 if (error)
1069                                         goto out;
1070                         }
1071                         switch (req) {
1072                         case PT_TO_SCE:
1073                                 p->p_ptevents |= PTRACE_SCE;
1074                                 CTR4(KTR_PTRACE,
1075                     "PT_TO_SCE: pid %d, events = %#x, PC = %#lx, sig = %d",
1076                                     p->p_pid, p->p_ptevents,
1077                                     (u_long)(uintfptr_t)addr, data);
1078                                 break;
1079                         case PT_TO_SCX:
1080                                 p->p_ptevents |= PTRACE_SCX;
1081                                 CTR4(KTR_PTRACE,
1082                     "PT_TO_SCX: pid %d, events = %#x, PC = %#lx, sig = %d",
1083                                     p->p_pid, p->p_ptevents,
1084                                     (u_long)(uintfptr_t)addr, data);
1085                                 break;
1086                         case PT_SYSCALL:
1087                                 p->p_ptevents |= PTRACE_SYSCALL;
1088                                 CTR4(KTR_PTRACE,
1089                     "PT_SYSCALL: pid %d, events = %#x, PC = %#lx, sig = %d",
1090                                     p->p_pid, p->p_ptevents,
1091                                     (u_long)(uintfptr_t)addr, data);
1092                                 break;
1093                         case PT_CONTINUE:
1094                                 CTR3(KTR_PTRACE,
1095                                     "PT_CONTINUE: pid %d, PC = %#lx, sig = %d",
1096                                     p->p_pid, (u_long)(uintfptr_t)addr, data);
1097                                 break;
1098                         }
1099                         break;
1100                 case PT_DETACH:
1101                         /*
1102                          * Clear P_TRACED before reparenting
1103                          * a detached process back to its original
1104                          * parent.  Otherwise the debugee will be set
1105                          * as an orphan of the debugger.
1106                          */
1107                         p->p_flag &= ~(P_TRACED | P_WAITED);
1108
1109                         /*
1110                          * Reset the process parent.
1111                          */
1112                         if (p->p_oppid != p->p_pptr->p_pid) {
1113                                 PROC_LOCK(p->p_pptr);
1114                                 sigqueue_take(p->p_ksi);
1115                                 PROC_UNLOCK(p->p_pptr);
1116
1117                                 pp = proc_realparent(p);
1118                                 proc_reparent(p, pp, false);
1119                                 if (pp == initproc)
1120                                         p->p_sigparent = SIGCHLD;
1121                                 CTR3(KTR_PTRACE,
1122                             "PT_DETACH: pid %d reparented to pid %d, sig %d",
1123                                     p->p_pid, pp->p_pid, data);
1124                         } else {
1125                                 CTR2(KTR_PTRACE, "PT_DETACH: pid %d, sig %d",
1126                                     p->p_pid, data);
1127                         }
1128
1129                         p->p_ptevents = 0;
1130                         FOREACH_THREAD_IN_PROC(p, td3) {
1131                                 if ((td3->td_dbgflags & TDB_FSTP) != 0) {
1132                                         sigqueue_delete(&td3->td_sigqueue,
1133                                             SIGSTOP);
1134                                 }
1135                                 td3->td_dbgflags &= ~(TDB_XSIG | TDB_FSTP |
1136                                     TDB_SUSPEND);
1137                         }
1138
1139                         if ((p->p_flag2 & P2_PTRACE_FSTP) != 0) {
1140                                 sigqueue_delete(&p->p_sigqueue, SIGSTOP);
1141                                 p->p_flag2 &= ~P2_PTRACE_FSTP;
1142                         }
1143
1144                         /* should we send SIGCHLD? */
1145                         /* childproc_continued(p); */
1146                         break;
1147                 }
1148
1149                 sx_xunlock(&proctree_lock);
1150                 proctree_locked = false;
1151
1152         sendsig:
1153                 MPASS(!proctree_locked);
1154
1155                 /*
1156                  * Clear the pending event for the thread that just
1157                  * reported its event (p_xthread).  This may not be
1158                  * the thread passed to PT_CONTINUE, PT_STEP, etc. if
1159                  * the debugger is resuming a different thread.
1160                  *
1161                  * Deliver any pending signal via the reporting thread.
1162                  */
1163                 MPASS(p->p_xthread != NULL);
1164                 p->p_xthread->td_dbgflags &= ~TDB_XSIG;
1165                 p->p_xthread->td_xsig = data;
1166                 p->p_xthread = NULL;
1167                 p->p_xsig = data;
1168
1169                 /*
1170                  * P_WKILLED is insurance that a PT_KILL/SIGKILL
1171                  * always works immediately, even if another thread is
1172                  * unsuspended first and attempts to handle a
1173                  * different signal or if the POSIX.1b style signal
1174                  * queue cannot accommodate any new signals.
1175                  */
1176                 if (data == SIGKILL)
1177                         proc_wkilled(p);
1178
1179                 /*
1180                  * Unsuspend all threads.  To leave a thread
1181                  * suspended, use PT_SUSPEND to suspend it before
1182                  * continuing the process.
1183                  */
1184                 ptrace_unsuspend(p);
1185                 break;
1186
1187         case PT_WRITE_I:
1188         case PT_WRITE_D:
1189                 td2->td_dbgflags |= TDB_USERWR;
1190                 PROC_UNLOCK(p);
1191                 error = 0;
1192                 if (proc_writemem(td, p, (off_t)(uintptr_t)addr, &data,
1193                     sizeof(int)) != sizeof(int))
1194                         error = ENOMEM;
1195                 else
1196                         CTR3(KTR_PTRACE, "PT_WRITE: pid %d: %p <= %#x",
1197                             p->p_pid, addr, data);
1198                 PROC_LOCK(p);
1199                 break;
1200
1201         case PT_READ_I:
1202         case PT_READ_D:
1203                 PROC_UNLOCK(p);
1204                 error = tmp = 0;
1205                 if (proc_readmem(td, p, (off_t)(uintptr_t)addr, &tmp,
1206                     sizeof(int)) != sizeof(int))
1207                         error = ENOMEM;
1208                 else
1209                         CTR3(KTR_PTRACE, "PT_READ: pid %d: %p >= %#x",
1210                             p->p_pid, addr, tmp);
1211                 td->td_retval[0] = tmp;
1212                 PROC_LOCK(p);
1213                 break;
1214
1215         case PT_IO:
1216                 piod = addr;
1217                 iov.iov_base = piod->piod_addr;
1218                 iov.iov_len = piod->piod_len;
1219                 uio.uio_offset = (off_t)(uintptr_t)piod->piod_offs;
1220                 uio.uio_resid = piod->piod_len;
1221                 uio.uio_iov = &iov;
1222                 uio.uio_iovcnt = 1;
1223                 uio.uio_segflg = UIO_USERSPACE;
1224                 uio.uio_td = td;
1225                 switch (piod->piod_op) {
1226                 case PIOD_READ_D:
1227                 case PIOD_READ_I:
1228                         CTR3(KTR_PTRACE, "PT_IO: pid %d: READ (%p, %#x)",
1229                             p->p_pid, (uintptr_t)uio.uio_offset, uio.uio_resid);
1230                         uio.uio_rw = UIO_READ;
1231                         break;
1232                 case PIOD_WRITE_D:
1233                 case PIOD_WRITE_I:
1234                         CTR3(KTR_PTRACE, "PT_IO: pid %d: WRITE (%p, %#x)",
1235                             p->p_pid, (uintptr_t)uio.uio_offset, uio.uio_resid);
1236                         td2->td_dbgflags |= TDB_USERWR;
1237                         uio.uio_rw = UIO_WRITE;
1238                         break;
1239                 default:
1240                         error = EINVAL;
1241                         goto out;
1242                 }
1243                 PROC_UNLOCK(p);
1244                 error = proc_rwmem(p, &uio);
1245                 piod->piod_len -= uio.uio_resid;
1246                 PROC_LOCK(p);
1247                 break;
1248
1249         case PT_KILL:
1250                 CTR1(KTR_PTRACE, "PT_KILL: pid %d", p->p_pid);
1251                 data = SIGKILL;
1252                 goto sendsig;   /* in PT_CONTINUE above */
1253
1254         case PT_SETREGS:
1255                 CTR2(KTR_PTRACE, "PT_SETREGS: tid %d (pid %d)", td2->td_tid,
1256                     p->p_pid);
1257                 td2->td_dbgflags |= TDB_USERWR;
1258                 error = PROC_WRITE(regs, td2, addr);
1259                 break;
1260
1261         case PT_GETREGS:
1262                 CTR2(KTR_PTRACE, "PT_GETREGS: tid %d (pid %d)", td2->td_tid,
1263                     p->p_pid);
1264                 error = PROC_READ(regs, td2, addr);
1265                 break;
1266
1267         case PT_SETFPREGS:
1268                 CTR2(KTR_PTRACE, "PT_SETFPREGS: tid %d (pid %d)", td2->td_tid,
1269                     p->p_pid);
1270                 td2->td_dbgflags |= TDB_USERWR;
1271                 error = PROC_WRITE(fpregs, td2, addr);
1272                 break;
1273
1274         case PT_GETFPREGS:
1275                 CTR2(KTR_PTRACE, "PT_GETFPREGS: tid %d (pid %d)", td2->td_tid,
1276                     p->p_pid);
1277                 error = PROC_READ(fpregs, td2, addr);
1278                 break;
1279
1280         case PT_SETDBREGS:
1281                 CTR2(KTR_PTRACE, "PT_SETDBREGS: tid %d (pid %d)", td2->td_tid,
1282                     p->p_pid);
1283                 td2->td_dbgflags |= TDB_USERWR;
1284                 error = PROC_WRITE(dbregs, td2, addr);
1285                 break;
1286
1287         case PT_GETDBREGS:
1288                 CTR2(KTR_PTRACE, "PT_GETDBREGS: tid %d (pid %d)", td2->td_tid,
1289                     p->p_pid);
1290                 error = PROC_READ(dbregs, td2, addr);
1291                 break;
1292
1293         case PT_LWPINFO:
1294                 if (data <= 0 || data > sizeof(*pl)) {
1295                         error = EINVAL;
1296                         break;
1297                 }
1298                 pl = addr;
1299                 bzero(pl, sizeof(*pl));
1300                 pl->pl_lwpid = td2->td_tid;
1301                 pl->pl_event = PL_EVENT_NONE;
1302                 pl->pl_flags = 0;
1303                 if (td2->td_dbgflags & TDB_XSIG) {
1304                         pl->pl_event = PL_EVENT_SIGNAL;
1305                         if (td2->td_si.si_signo != 0 &&
1306                             data >= offsetof(struct ptrace_lwpinfo, pl_siginfo)
1307                             + sizeof(pl->pl_siginfo)){
1308                                 pl->pl_flags |= PL_FLAG_SI;
1309                                 pl->pl_siginfo = td2->td_si;
1310                         }
1311                 }
1312                 if (td2->td_dbgflags & TDB_SCE)
1313                         pl->pl_flags |= PL_FLAG_SCE;
1314                 else if (td2->td_dbgflags & TDB_SCX)
1315                         pl->pl_flags |= PL_FLAG_SCX;
1316                 if (td2->td_dbgflags & TDB_EXEC)
1317                         pl->pl_flags |= PL_FLAG_EXEC;
1318                 if (td2->td_dbgflags & TDB_FORK) {
1319                         pl->pl_flags |= PL_FLAG_FORKED;
1320                         pl->pl_child_pid = td2->td_dbg_forked;
1321                         if (td2->td_dbgflags & TDB_VFORK)
1322                                 pl->pl_flags |= PL_FLAG_VFORKED;
1323                 } else if ((td2->td_dbgflags & (TDB_SCX | TDB_VFORK)) ==
1324                     TDB_VFORK)
1325                         pl->pl_flags |= PL_FLAG_VFORK_DONE;
1326                 if (td2->td_dbgflags & TDB_CHILD)
1327                         pl->pl_flags |= PL_FLAG_CHILD;
1328                 if (td2->td_dbgflags & TDB_BORN)
1329                         pl->pl_flags |= PL_FLAG_BORN;
1330                 if (td2->td_dbgflags & TDB_EXIT)
1331                         pl->pl_flags |= PL_FLAG_EXITED;
1332                 pl->pl_sigmask = td2->td_sigmask;
1333                 pl->pl_siglist = td2->td_siglist;
1334                 strcpy(pl->pl_tdname, td2->td_name);
1335                 if ((td2->td_dbgflags & (TDB_SCE | TDB_SCX)) != 0) {
1336                         pl->pl_syscall_code = td2->td_sa.code;
1337                         pl->pl_syscall_narg = td2->td_sa.callp->sy_narg;
1338                 } else {
1339                         pl->pl_syscall_code = 0;
1340                         pl->pl_syscall_narg = 0;
1341                 }
1342                 CTR6(KTR_PTRACE,
1343     "PT_LWPINFO: tid %d (pid %d) event %d flags %#x child pid %d syscall %d",
1344                     td2->td_tid, p->p_pid, pl->pl_event, pl->pl_flags,
1345                     pl->pl_child_pid, pl->pl_syscall_code);
1346                 break;
1347
1348         case PT_GETNUMLWPS:
1349                 CTR2(KTR_PTRACE, "PT_GETNUMLWPS: pid %d: %d threads", p->p_pid,
1350                     p->p_numthreads);
1351                 td->td_retval[0] = p->p_numthreads;
1352                 break;
1353
1354         case PT_GETLWPLIST:
1355                 CTR3(KTR_PTRACE, "PT_GETLWPLIST: pid %d: data %d, actual %d",
1356                     p->p_pid, data, p->p_numthreads);
1357                 if (data <= 0) {
1358                         error = EINVAL;
1359                         break;
1360                 }
1361                 num = imin(p->p_numthreads, data);
1362                 PROC_UNLOCK(p);
1363                 buf = malloc(num * sizeof(lwpid_t), M_TEMP, M_WAITOK);
1364                 tmp = 0;
1365                 PROC_LOCK(p);
1366                 FOREACH_THREAD_IN_PROC(p, td2) {
1367                         if (tmp >= num)
1368                                 break;
1369                         buf[tmp++] = td2->td_tid;
1370                 }
1371                 PROC_UNLOCK(p);
1372                 error = copyout(buf, addr, tmp * sizeof(lwpid_t));
1373                 free(buf, M_TEMP);
1374                 if (!error)
1375                         td->td_retval[0] = tmp;
1376                 PROC_LOCK(p);
1377                 break;
1378
1379         case PT_VM_TIMESTAMP:
1380                 CTR2(KTR_PTRACE, "PT_VM_TIMESTAMP: pid %d: timestamp %d",
1381                     p->p_pid, p->p_vmspace->vm_map.timestamp);
1382                 td->td_retval[0] = p->p_vmspace->vm_map.timestamp;
1383                 break;
1384
1385         case PT_VM_ENTRY:
1386                 PROC_UNLOCK(p);
1387                 error = ptrace_vm_entry(td, p, addr);
1388                 PROC_LOCK(p);
1389                 break;
1390
1391         case PT_COREDUMP:
1392                 pc = addr;
1393                 CTR2(KTR_PTRACE, "PT_COREDUMP: pid %d, fd %d",
1394                     p->p_pid, pc->pc_fd);
1395
1396                 if ((pc->pc_flags & ~(PC_COMPRESS | PC_ALL)) != 0) {
1397                         error = EINVAL;
1398                         break;
1399                 }
1400                 PROC_UNLOCK(p);
1401
1402                 tcq = malloc(sizeof(*tcq), M_TEMP, M_WAITOK | M_ZERO);
1403                 fp = NULL;
1404                 error = fget_write(td, pc->pc_fd, &cap_write_rights, &fp);
1405                 if (error != 0)
1406                         goto coredump_cleanup_nofp;
1407                 if (fp->f_type != DTYPE_VNODE || fp->f_vnode->v_type != VREG) {
1408                         error = EPIPE;
1409                         goto coredump_cleanup;
1410                 }
1411
1412                 PROC_LOCK(p);
1413                 error = proc_can_ptrace(td, p);
1414                 if (error != 0)
1415                         goto coredump_cleanup_locked;
1416
1417                 td2 = ptrace_sel_coredump_thread(p);
1418                 if (td2 == NULL) {
1419                         error = EBUSY;
1420                         goto coredump_cleanup_locked;
1421                 }
1422                 KASSERT((td2->td_dbgflags & TDB_COREDUMPRQ) == 0,
1423                     ("proc %d tid %d req coredump", p->p_pid, td2->td_tid));
1424
1425                 tcq->tc_vp = fp->f_vnode;
1426                 tcq->tc_limit = pc->pc_limit == 0 ? OFF_MAX : pc->pc_limit;
1427                 tcq->tc_flags = SVC_PT_COREDUMP;
1428                 if ((pc->pc_flags & PC_COMPRESS) == 0)
1429                         tcq->tc_flags |= SVC_NOCOMPRESS;
1430                 if ((pc->pc_flags & PC_ALL) != 0)
1431                         tcq->tc_flags |= SVC_ALL;
1432                 td2->td_coredump = tcq;
1433                 td2->td_dbgflags |= TDB_COREDUMPRQ;
1434                 thread_run_flash(td2);
1435                 while ((td2->td_dbgflags & TDB_COREDUMPRQ) != 0)
1436                         msleep(p, &p->p_mtx, PPAUSE, "crdmp", 0);
1437                 error = tcq->tc_error;
1438 coredump_cleanup_locked:
1439                 PROC_UNLOCK(p);
1440 coredump_cleanup:
1441                 fdrop(fp, td);
1442 coredump_cleanup_nofp:
1443                 free(tcq, M_TEMP);
1444                 PROC_LOCK(p);
1445                 break;
1446
1447         default:
1448 #ifdef __HAVE_PTRACE_MACHDEP
1449                 if (req >= PT_FIRSTMACH) {
1450                         PROC_UNLOCK(p);
1451                         error = cpu_ptrace(td2, req, addr, data);
1452                         PROC_LOCK(p);
1453                 } else
1454 #endif
1455                         /* Unknown request. */
1456                         error = EINVAL;
1457                 break;
1458         }
1459 out:
1460         /* Drop our hold on this process now that the request has completed. */
1461         _PRELE(p);
1462 fail:
1463         if (p2_req_set) {
1464                 if ((p->p_flag2 & P2_PTRACEREQ) != 0)
1465                         wakeup(&p->p_flag2);
1466                 p->p_flag2 &= ~P2_PTRACEREQ;
1467         }
1468         PROC_UNLOCK(p);
1469         if (proctree_locked)
1470                 sx_xunlock(&proctree_lock);
1471         return (error);
1472 }
1473 #undef PROC_READ
1474 #undef PROC_WRITE