sys/kern/sys_process.c

   1 /*-
   2  * Copyright (c) 1994, Sean Eric Fagan
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by Sean Eric Fagan.
  16  * 4. The name of the author may not be used to endorse or promote products
  17  *    derived from this software without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 #include <sys/cdefs.h>
  33 __FBSDID("$FreeBSD$");
  34
  35 #include "opt_compat.h"
  36
  37 #include <sys/param.h>
  38 #include <sys/systm.h>
  39 #include <sys/lock.h>
  40 #include <sys/mutex.h>
  41 #include <sys/syscallsubr.h>
  42 #include <sys/sysent.h>
  43 #include <sys/sysproto.h>
  44 #include <sys/proc.h>
  45 #include <sys/vnode.h>
  46 #include <sys/ptrace.h>
  47 #include <sys/sx.h>
  48 #include <sys/malloc.h>
  49 #include <sys/signalvar.h>
  50
  51 #include <machine/reg.h>
  52
  53 #include <security/audit/audit.h>
  54
  55 #include <vm/vm.h>
  56 #include <vm/pmap.h>
  57 #include <vm/vm_extern.h>
  58 #include <vm/vm_map.h>
  59 #include <vm/vm_kern.h>
  60 #include <vm/vm_object.h>
  61 #include <vm/vm_page.h>
  62 #include <vm/vm_pager.h>
  63 #include <vm/vm_param.h>
  64
  65 #ifdef COMPAT_FREEBSD32
  66 #include <sys/procfs.h>
  67 #include <compat/freebsd32/freebsd32_signal.h>
  68
  69 struct ptrace_io_desc32 {
  70         int             piod_op;
  71         uint32_t        piod_offs;
  72         uint32_t        piod_addr;
  73         uint32_t        piod_len;
  74 };
  75
  76 struct ptrace_vm_entry32 {
  77         int             pve_entry;
  78         int             pve_timestamp;
  79         uint32_t        pve_start;
  80         uint32_t        pve_end;
  81         uint32_t        pve_offset;
  82         u_int           pve_prot;
  83         u_int           pve_pathlen;
  84         int32_t         pve_fileid;
  85         u_int           pve_fsid;
  86         uint32_t        pve_path;
  87 };
  88
  89 struct ptrace_lwpinfo32 {
  90         lwpid_t pl_lwpid;       /* LWP described. */
  91         int     pl_event;       /* Event that stopped the LWP. */
  92         int     pl_flags;       /* LWP flags. */
  93         sigset_t        pl_sigmask;     /* LWP signal mask */
  94         sigset_t        pl_siglist;     /* LWP pending signal */
  95         struct siginfo32 pl_siginfo;    /* siginfo for signal */
  96         char    pl_tdname[MAXCOMLEN + 1];       /* LWP name. */
  97 };
  98
  99 #endif
 100
 101 /*
 102  * Functions implemented using PROC_ACTION():
 103  *
 104  * proc_read_regs(proc, regs)
 105  *      Get the current user-visible register set from the process
 106  *      and copy it into the regs structure (<machine/reg.h>).
 107  *      The process is stopped at the time read_regs is called.
 108  *
 109  * proc_write_regs(proc, regs)
 110  *      Update the current register set from the passed in regs
 111  *      structure.  Take care to avoid clobbering special CPU
 112  *      registers or privileged bits in the PSL.
 113  *      Depending on the architecture this may have fix-up work to do,
 114  *      especially if the IAR or PCW are modified.
 115  *      The process is stopped at the time write_regs is called.
 116  *
 117  * proc_read_fpregs, proc_write_fpregs
 118  *      deal with the floating point register set, otherwise as above.
 119  *
 120  * proc_read_dbregs, proc_write_dbregs
 121  *      deal with the processor debug register set, otherwise as above.
 122  *
 123  * proc_sstep(proc)
 124  *      Arrange for the process to trap after executing a single instruction.
 125  */
 126
 127 #define PROC_ACTION(action) do {                                        \
 128         int error;                                                      \
 129                                                                         \
 130         PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);                        \
 131         if ((td->td_proc->p_flag & P_INMEM) == 0)                       \
 132                 error = EIO;                                            \
 133         else                                                            \
 134                 error = (action);                                       \
 135         return (error);                                                 \
 136 } while(0)
 137
 138 int
 139 proc_read_regs(struct thread *td, struct reg *regs)
 140 {
 141
 142         PROC_ACTION(fill_regs(td, regs));
 143 }
 144
 145 int
 146 proc_write_regs(struct thread *td, struct reg *regs)
 147 {
 148
 149         PROC_ACTION(set_regs(td, regs));
 150 }
 151
 152 int
 153 proc_read_dbregs(struct thread *td, struct dbreg *dbregs)
 154 {
 155
 156         PROC_ACTION(fill_dbregs(td, dbregs));
 157 }
 158
 159 int
 160 proc_write_dbregs(struct thread *td, struct dbreg *dbregs)
 161 {
 162
 163         PROC_ACTION(set_dbregs(td, dbregs));
 164 }
 165
 166 /*
 167  * Ptrace doesn't support fpregs at all, and there are no security holes
 168  * or translations for fpregs, so we can just copy them.
 169  */
 170 int
 171 proc_read_fpregs(struct thread *td, struct fpreg *fpregs)
 172 {
 173
 174         PROC_ACTION(fill_fpregs(td, fpregs));
 175 }
 176
 177 int
 178 proc_write_fpregs(struct thread *td, struct fpreg *fpregs)
 179 {
 180
 181         PROC_ACTION(set_fpregs(td, fpregs));
 182 }
 183
 184 #ifdef COMPAT_FREEBSD32
 185 /* For 32 bit binaries, we need to expose the 32 bit regs layouts. */
 186 int
 187 proc_read_regs32(struct thread *td, struct reg32 *regs32)
 188 {
 189
 190         PROC_ACTION(fill_regs32(td, regs32));
 191 }
 192
 193 int
 194 proc_write_regs32(struct thread *td, struct reg32 *regs32)
 195 {
 196
 197         PROC_ACTION(set_regs32(td, regs32));
 198 }
 199
 200 int
 201 proc_read_dbregs32(struct thread *td, struct dbreg32 *dbregs32)
 202 {
 203
 204         PROC_ACTION(fill_dbregs32(td, dbregs32));
 205 }
 206
 207 int
 208 proc_write_dbregs32(struct thread *td, struct dbreg32 *dbregs32)
 209 {
 210
 211         PROC_ACTION(set_dbregs32(td, dbregs32));
 212 }
 213
 214 int
 215 proc_read_fpregs32(struct thread *td, struct fpreg32 *fpregs32)
 216 {
 217
 218         PROC_ACTION(fill_fpregs32(td, fpregs32));
 219 }
 220
 221 int
 222 proc_write_fpregs32(struct thread *td, struct fpreg32 *fpregs32)
 223 {
 224
 225         PROC_ACTION(set_fpregs32(td, fpregs32));
 226 }
 227 #endif
 228
 229 int
 230 proc_sstep(struct thread *td)
 231 {
 232
 233         PROC_ACTION(ptrace_single_step(td));
 234 }
 235
 236 int
 237 proc_rwmem(struct proc *p, struct uio *uio)
 238 {
 239         vm_map_t map;
 240         vm_offset_t pageno;             /* page number */
 241         vm_prot_t reqprot;
 242         int error, fault_flags, page_offset, writing;
 243
 244         /*
 245          * Assert that someone has locked this vmspace.  (Should be
 246          * curthread but we can't assert that.)  This keeps the process
 247          * from exiting out from under us until this operation completes.
 248          */
 249         KASSERT(p->p_lock >= 1, ("%s: process %p (pid %d) not held", __func__,
 250             p, p->p_pid));
 251
 252         /*
 253          * The map we want...
 254          */
 255         map = &p->p_vmspace->vm_map;
 256
 257         /*
 258          * If we are writing, then we request vm_fault() to create a private
 259          * copy of each page.  Since these copies will not be writeable by the
 260          * process, we must explicity request that they be dirtied.
 261          */
 262         writing = uio->uio_rw == UIO_WRITE;
 263         reqprot = writing ? VM_PROT_COPY | VM_PROT_READ : VM_PROT_READ;
 264         fault_flags = writing ? VM_FAULT_DIRTY : VM_FAULT_NORMAL;
 265
 266         /*
 267          * Only map in one page at a time.  We don't have to, but it
 268          * makes things easier.  This way is trivial - right?
 269          */
 270         do {
 271                 vm_offset_t uva;
 272                 u_int len;
 273                 vm_page_t m;
 274
 275                 uva = (vm_offset_t)uio->uio_offset;
 276
 277                 /*
 278                  * Get the page number of this segment.
 279                  */
 280                 pageno = trunc_page(uva);
 281                 page_offset = uva - pageno;
 282
 283                 /*
 284                  * How many bytes to copy
 285                  */
 286                 len = min(PAGE_SIZE - page_offset, uio->uio_resid);
 287
 288                 /*
 289                  * Fault and hold the page on behalf of the process.
 290                  */
 291                 error = vm_fault_hold(map, pageno, reqprot, fault_flags, &m);
 292                 if (error != KERN_SUCCESS) {
 293                         if (error == KERN_RESOURCE_SHORTAGE)
 294                                 error = ENOMEM;
 295                         else
 296                                 error = EFAULT;
 297                         break;
 298                 }
 299
 300                 /*
 301                  * Now do the i/o move.
 302                  */
 303                 error = uiomove_fromphys(&m, page_offset, len, uio);
 304
 305                 /* Make the I-cache coherent for breakpoints. */
 306                 if (writing && error == 0) {
 307                         vm_map_lock_read(map);
 308                         if (vm_map_check_protection(map, pageno, pageno +
 309                             PAGE_SIZE, VM_PROT_EXECUTE))
 310                                 vm_sync_icache(map, uva, len);
 311                         vm_map_unlock_read(map);
 312                 }
 313
 314                 /*
 315                  * Release the page.
 316                  */
 317                 vm_page_lock(m);
 318                 vm_page_unhold(m);
 319                 vm_page_unlock(m);
 320
 321         } while (error == 0 && uio->uio_resid > 0);
 322
 323         return (error);
 324 }
 325
 326 static int
 327 ptrace_vm_entry(struct thread *td, struct proc *p, struct ptrace_vm_entry *pve)
 328 {
 329         struct vattr vattr;
 330         vm_map_t map;
 331         vm_map_entry_t entry;
 332         vm_object_t obj, tobj, lobj;
 333         struct vmspace *vm;
 334         struct vnode *vp;
 335         char *freepath, *fullpath;
 336         u_int pathlen;
 337         int error, index, vfslocked;
 338
 339         error = 0;
 340         obj = NULL;
 341
 342         vm = vmspace_acquire_ref(p);
 343         map = &vm->vm_map;
 344         vm_map_lock_read(map);
 345
 346         do {
 347                 entry = map->header.next;
 348                 index = 0;
 349                 while (index < pve->pve_entry && entry != &map->header) {
 350                         entry = entry->next;
 351                         index++;
 352                 }
 353                 if (index != pve->pve_entry) {
 354                         error = EINVAL;
 355                         break;
 356                 }
 357                 while (entry != &map->header &&
 358                     (entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0) {
 359                         entry = entry->next;
 360                         index++;
 361                 }
 362                 if (entry == &map->header) {
 363                         error = ENOENT;
 364                         break;
 365                 }
 366
 367                 /* We got an entry. */
 368                 pve->pve_entry = index + 1;
 369                 pve->pve_timestamp = map->timestamp;
 370                 pve->pve_start = entry->start;
 371                 pve->pve_end = entry->end - 1;
 372                 pve->pve_offset = entry->offset;
 373                 pve->pve_prot = entry->protection;
 374
 375                 /* Backing object's path needed? */
 376                 if (pve->pve_pathlen == 0)
 377                         break;
 378
 379                 pathlen = pve->pve_pathlen;
 380                 pve->pve_pathlen = 0;
 381
 382                 obj = entry->object.vm_object;
 383                 if (obj != NULL)
 384                         VM_OBJECT_LOCK(obj);
 385         } while (0);
 386
 387         vm_map_unlock_read(map);
 388         vmspace_free(vm);
 389
 390         pve->pve_fsid = VNOVAL;
 391         pve->pve_fileid = VNOVAL;
 392
 393         if (error == 0 && obj != NULL) {
 394                 lobj = obj;
 395                 for (tobj = obj; tobj != NULL; tobj = tobj->backing_object) {
 396                         if (tobj != obj)
 397                                 VM_OBJECT_LOCK(tobj);
 398                         if (lobj != obj)
 399                                 VM_OBJECT_UNLOCK(lobj);
 400                         lobj = tobj;
 401                         pve->pve_offset += tobj->backing_object_offset;
 402                 }
 403                 vp = (lobj->type == OBJT_VNODE) ? lobj->handle : NULL;
 404                 if (vp != NULL)
 405                         vref(vp);
 406                 if (lobj != obj)
 407                         VM_OBJECT_UNLOCK(lobj);
 408                 VM_OBJECT_UNLOCK(obj);
 409
 410                 if (vp != NULL) {
 411                         freepath = NULL;
 412                         fullpath = NULL;
 413                         vn_fullpath(td, vp, &fullpath, &freepath);
 414                         vfslocked = VFS_LOCK_GIANT(vp->v_mount);
 415                         vn_lock(vp, LK_SHARED | LK_RETRY);
 416                         if (VOP_GETATTR(vp, &vattr, td->td_ucred) == 0) {
 417                                 pve->pve_fileid = vattr.va_fileid;
 418                                 pve->pve_fsid = vattr.va_fsid;
 419                         }
 420                         vput(vp);
 421                         VFS_UNLOCK_GIANT(vfslocked);
 422
 423                         if (fullpath != NULL) {
 424                                 pve->pve_pathlen = strlen(fullpath) + 1;
 425                                 if (pve->pve_pathlen <= pathlen) {
 426                                         error = copyout(fullpath, pve->pve_path,
 427                                             pve->pve_pathlen);
 428                                 } else
 429                                         error = ENAMETOOLONG;
 430                         }
 431                         if (freepath != NULL)
 432                                 free(freepath, M_TEMP);
 433                 }
 434         }
 435
 436         return (error);
 437 }
 438
 439 #ifdef COMPAT_FREEBSD32
 440 static int
 441 ptrace_vm_entry32(struct thread *td, struct proc *p,
 442     struct ptrace_vm_entry32 *pve32)
 443 {
 444         struct ptrace_vm_entry pve;
 445         int error;
 446
 447         pve.pve_entry = pve32->pve_entry;
 448         pve.pve_pathlen = pve32->pve_pathlen;
 449         pve.pve_path = (void *)(uintptr_t)pve32->pve_path;
 450
 451         error = ptrace_vm_entry(td, p, &pve);
 452         if (error == 0) {
 453                 pve32->pve_entry = pve.pve_entry;
 454                 pve32->pve_timestamp = pve.pve_timestamp;
 455                 pve32->pve_start = pve.pve_start;
 456                 pve32->pve_end = pve.pve_end;
 457                 pve32->pve_offset = pve.pve_offset;
 458                 pve32->pve_prot = pve.pve_prot;
 459                 pve32->pve_fileid = pve.pve_fileid;
 460                 pve32->pve_fsid = pve.pve_fsid;
 461         }
 462
 463         pve32->pve_pathlen = pve.pve_pathlen;
 464         return (error);
 465 }
 466
 467 static void
 468 ptrace_lwpinfo_to32(const struct ptrace_lwpinfo *pl,
 469     struct ptrace_lwpinfo32 *pl32)
 470 {
 471
 472         pl32->pl_lwpid = pl->pl_lwpid;
 473         pl32->pl_event = pl->pl_event;
 474         pl32->pl_flags = pl->pl_flags;
 475         pl32->pl_sigmask = pl->pl_sigmask;
 476         pl32->pl_siglist = pl->pl_siglist;
 477         siginfo_to_siginfo32(&pl->pl_siginfo, &pl32->pl_siginfo);
 478         strcpy(pl32->pl_tdname, pl->pl_tdname);
 479 }
 480 #endif /* COMPAT_FREEBSD32 */
 481
 482 /*
 483  * Process debugging system call.
 484  */
 485 #ifndef _SYS_SYSPROTO_H_
 486 struct ptrace_args {
 487         int     req;
 488         pid_t   pid;
 489         caddr_t addr;
 490         int     data;
 491 };
 492 #endif
 493
 494 #ifdef COMPAT_FREEBSD32
 495 /*
 496  * This CPP subterfuge is to try and reduce the number of ifdefs in
 497  * the body of the code.
 498  *   COPYIN(uap->addr, &r.reg, sizeof r.reg);
 499  * becomes either:
 500  *   copyin(uap->addr, &r.reg, sizeof r.reg);
 501  * or
 502  *   copyin(uap->addr, &r.reg32, sizeof r.reg32);
 503  * .. except this is done at runtime.
 504  */
 505 #define COPYIN(u, k, s)         wrap32 ? \
 506         copyin(u, k ## 32, s ## 32) : \
 507         copyin(u, k, s)
 508 #define COPYOUT(k, u, s)        wrap32 ? \
 509         copyout(k ## 32, u, s ## 32) : \
 510         copyout(k, u, s)
 511 #else
 512 #define COPYIN(u, k, s)         copyin(u, k, s)
 513 #define COPYOUT(k, u, s)        copyout(k, u, s)
 514 #endif
 515 int
 516 ptrace(struct thread *td, struct ptrace_args *uap)
 517 {
 518         /*
 519          * XXX this obfuscation is to reduce stack usage, but the register
 520          * structs may be too large to put on the stack anyway.
 521          */
 522         union {
 523                 struct ptrace_io_desc piod;
 524                 struct ptrace_lwpinfo pl;
 525                 struct ptrace_vm_entry pve;
 526                 struct dbreg dbreg;
 527                 struct fpreg fpreg;
 528                 struct reg reg;
 529 #ifdef COMPAT_FREEBSD32
 530                 struct dbreg32 dbreg32;
 531                 struct fpreg32 fpreg32;
 532                 struct reg32 reg32;
 533                 struct ptrace_io_desc32 piod32;
 534                 struct ptrace_lwpinfo32 pl32;
 535                 struct ptrace_vm_entry32 pve32;
 536 #endif
 537         } r;
 538         void *addr;
 539         int error = 0;
 540 #ifdef COMPAT_FREEBSD32
 541         int wrap32 = 0;
 542
 543         if (SV_CURPROC_FLAG(SV_ILP32))
 544                 wrap32 = 1;
 545 #endif
 546         AUDIT_ARG_PID(uap->pid);
 547         AUDIT_ARG_CMD(uap->req);
 548         AUDIT_ARG_VALUE(uap->data);
 549         addr = &r;
 550         switch (uap->req) {
 551         case PT_GETREGS:
 552         case PT_GETFPREGS:
 553         case PT_GETDBREGS:
 554         case PT_LWPINFO:
 555                 break;
 556         case PT_SETREGS:
 557                 error = COPYIN(uap->addr, &r.reg, sizeof r.reg);
 558                 break;
 559         case PT_SETFPREGS:
 560                 error = COPYIN(uap->addr, &r.fpreg, sizeof r.fpreg);
 561                 break;
 562         case PT_SETDBREGS:
 563                 error = COPYIN(uap->addr, &r.dbreg, sizeof r.dbreg);
 564                 break;
 565         case PT_IO:
 566                 error = COPYIN(uap->addr, &r.piod, sizeof r.piod);
 567                 break;
 568         case PT_VM_ENTRY:
 569                 error = COPYIN(uap->addr, &r.pve, sizeof r.pve);
 570                 break;
 571         default:
 572                 addr = uap->addr;
 573                 break;
 574         }
 575         if (error)
 576                 return (error);
 577
 578         error = kern_ptrace(td, uap->req, uap->pid, addr, uap->data);
 579         if (error)
 580                 return (error);
 581
 582         switch (uap->req) {
 583         case PT_VM_ENTRY:
 584                 error = COPYOUT(&r.pve, uap->addr, sizeof r.pve);
 585                 break;
 586         case PT_IO:
 587                 error = COPYOUT(&r.piod, uap->addr, sizeof r.piod);
 588                 break;
 589         case PT_GETREGS:
 590                 error = COPYOUT(&r.reg, uap->addr, sizeof r.reg);
 591                 break;
 592         case PT_GETFPREGS:
 593                 error = COPYOUT(&r.fpreg, uap->addr, sizeof r.fpreg);
 594                 break;
 595         case PT_GETDBREGS:
 596                 error = COPYOUT(&r.dbreg, uap->addr, sizeof r.dbreg);
 597                 break;
 598         case PT_LWPINFO:
 599                 error = copyout(&r.pl, uap->addr, uap->data);
 600                 break;
 601         }
 602
 603         return (error);
 604 }
 605 #undef COPYIN
 606 #undef COPYOUT
 607
 608 #ifdef COMPAT_FREEBSD32
 609 /*
 610  *   PROC_READ(regs, td2, addr);
 611  * becomes either:
 612  *   proc_read_regs(td2, addr);
 613  * or
 614  *   proc_read_regs32(td2, addr);
 615  * .. except this is done at runtime.  There is an additional
 616  * complication in that PROC_WRITE disallows 32 bit consumers
 617  * from writing to 64 bit address space targets.
 618  */
 619 #define PROC_READ(w, t, a)      wrap32 ? \
 620         proc_read_ ## w ## 32(t, a) : \
 621         proc_read_ ## w (t, a)
 622 #define PROC_WRITE(w, t, a)     wrap32 ? \
 623         (safe ? proc_write_ ## w ## 32(t, a) : EINVAL ) : \
 624         proc_write_ ## w (t, a)
 625 #else
 626 #define PROC_READ(w, t, a)      proc_read_ ## w (t, a)
 627 #define PROC_WRITE(w, t, a)     proc_write_ ## w (t, a)
 628 #endif
 629
 630 int
 631 kern_ptrace(struct thread *td, int req, pid_t pid, void *addr, int data)
 632 {
 633         struct iovec iov;
 634         struct uio uio;
 635         struct proc *curp, *p, *pp;
 636         struct thread *td2 = NULL;
 637         struct ptrace_io_desc *piod = NULL;
 638         struct ptrace_lwpinfo *pl;
 639         int error, write, tmp, num;
 640         int proctree_locked = 0;
 641         lwpid_t tid = 0, *buf;
 642 #ifdef COMPAT_FREEBSD32
 643         int wrap32 = 0, safe = 0;
 644         struct ptrace_io_desc32 *piod32 = NULL;
 645         struct ptrace_lwpinfo32 *pl32 = NULL;
 646         struct ptrace_lwpinfo plr;
 647 #endif
 648
 649         curp = td->td_proc;
 650
 651         /* Lock proctree before locking the process. */
 652         switch (req) {
 653         case PT_TRACE_ME:
 654         case PT_ATTACH:
 655         case PT_STEP:
 656         case PT_CONTINUE:
 657         case PT_TO_SCE:
 658         case PT_TO_SCX:
 659         case PT_SYSCALL:
 660         case PT_DETACH:
 661                 sx_xlock(&proctree_lock);
 662                 proctree_locked = 1;
 663                 break;
 664         default:
 665                 break;
 666         }
 667
 668         write = 0;
 669         if (req == PT_TRACE_ME) {
 670                 p = td->td_proc;
 671                 PROC_LOCK(p);
 672         } else {
 673                 if (pid <= PID_MAX) {
 674                         if ((p = pfind(pid)) == NULL) {
 675                                 if (proctree_locked)
 676                                         sx_xunlock(&proctree_lock);
 677                                 return (ESRCH);
 678                         }
 679                 } else {
 680                         td2 = tdfind(pid, -1);
 681                         if (td2 == NULL) {
 682                                 if (proctree_locked)
 683                                         sx_xunlock(&proctree_lock);
 684                                 return (ESRCH);
 685                         }
 686                         p = td2->td_proc;
 687                         tid = pid;
 688                         pid = p->p_pid;
 689                 }
 690         }
 691         AUDIT_ARG_PROCESS(p);
 692
 693         if ((p->p_flag & P_WEXIT) != 0) {
 694                 error = ESRCH;
 695                 goto fail;
 696         }
 697         if ((error = p_cansee(td, p)) != 0)
 698                 goto fail;
 699
 700         if ((error = p_candebug(td, p)) != 0)
 701                 goto fail;
 702
 703         /*
 704          * System processes can't be debugged.
 705          */
 706         if ((p->p_flag & P_SYSTEM) != 0) {
 707                 error = EINVAL;
 708                 goto fail;
 709         }
 710
 711         if (tid == 0) {
 712                 if ((p->p_flag & P_STOPPED_TRACE) != 0) {
 713                         KASSERT(p->p_xthread != NULL, ("NULL p_xthread"));
 714                         td2 = p->p_xthread;
 715                 } else {
 716                         td2 = FIRST_THREAD_IN_PROC(p);
 717                 }
 718                 tid = td2->td_tid;
 719         }
 720
 721 #ifdef COMPAT_FREEBSD32
 722         /*
 723          * Test if we're a 32 bit client and what the target is.
 724          * Set the wrap controls accordingly.
 725          */
 726         if (SV_CURPROC_FLAG(SV_ILP32)) {
 727                 if (td2->td_proc->p_sysent->sv_flags & SV_ILP32)
 728                         safe = 1;
 729                 wrap32 = 1;
 730         }
 731 #endif
 732         /*
 733          * Permissions check
 734          */
 735         switch (req) {
 736         case PT_TRACE_ME:
 737                 /* Always legal. */
 738                 break;
 739
 740         case PT_ATTACH:
 741                 /* Self */
 742                 if (p->p_pid == td->td_proc->p_pid) {
 743                         error = EINVAL;
 744                         goto fail;
 745                 }
 746
 747                 /* Already traced */
 748                 if (p->p_flag & P_TRACED) {
 749                         error = EBUSY;
 750                         goto fail;
 751                 }
 752
 753                 /* Can't trace an ancestor if you're being traced. */
 754                 if (curp->p_flag & P_TRACED) {
 755                         for (pp = curp->p_pptr; pp != NULL; pp = pp->p_pptr) {
 756                                 if (pp == p) {
 757                                         error = EINVAL;
 758                                         goto fail;
 759                                 }
 760                         }
 761                 }
 762
 763
 764                 /* OK */
 765                 break;
 766
 767         case PT_CLEARSTEP:
 768                 /* Allow thread to clear single step for itself */
 769                 if (td->td_tid == tid)
 770                         break;
 771
 772                 /* FALLTHROUGH */
 773         default:
 774                 /* not being traced... */
 775                 if ((p->p_flag & P_TRACED) == 0) {
 776                         error = EPERM;
 777                         goto fail;
 778                 }
 779
 780                 /* not being traced by YOU */
 781                 if (p->p_pptr != td->td_proc) {
 782                         error = EBUSY;
 783                         goto fail;
 784                 }
 785
 786                 /* not currently stopped */
 787                 if ((p->p_flag & (P_STOPPED_SIG | P_STOPPED_TRACE)) == 0 ||
 788                     p->p_suspcount != p->p_numthreads  ||
 789                     (p->p_flag & P_WAITED) == 0) {
 790                         error = EBUSY;
 791                         goto fail;
 792                 }
 793
 794                 if ((p->p_flag & P_STOPPED_TRACE) == 0) {
 795                         static int count = 0;
 796                         if (count++ == 0)
 797                                 printf("P_STOPPED_TRACE not set.\n");
 798                 }
 799
 800                 /* OK */
 801                 break;
 802         }
 803
 804         /* Keep this process around until we finish this request. */
 805         _PHOLD(p);
 806
 807 #ifdef FIX_SSTEP
 808         /*
 809          * Single step fixup ala procfs
 810          */
 811         FIX_SSTEP(td2);
 812 #endif
 813
 814         /*
 815          * Actually do the requests
 816          */
 817
 818         td->td_retval[0] = 0;
 819
 820         switch (req) {
 821         case PT_TRACE_ME:
 822                 /* set my trace flag and "owner" so it can read/write me */
 823                 p->p_flag |= P_TRACED;
 824                 p->p_oppid = p->p_pptr->p_pid;
 825                 break;
 826
 827         case PT_ATTACH:
 828                 /* security check done above */
 829                 p->p_flag |= P_TRACED;
 830                 p->p_oppid = p->p_pptr->p_pid;
 831                 if (p->p_pptr != td->td_proc)
 832                         proc_reparent(p, td->td_proc);
 833                 data = SIGSTOP;
 834                 goto sendsig;   /* in PT_CONTINUE below */
 835
 836         case PT_CLEARSTEP:
 837                 error = ptrace_clear_single_step(td2);
 838                 break;
 839
 840         case PT_SETSTEP:
 841                 error = ptrace_single_step(td2);
 842                 break;
 843
 844         case PT_SUSPEND:
 845                 td2->td_dbgflags |= TDB_SUSPEND;
 846                 thread_lock(td2);
 847                 td2->td_flags |= TDF_NEEDSUSPCHK;
 848                 thread_unlock(td2);
 849                 break;
 850
 851         case PT_RESUME:
 852                 td2->td_dbgflags &= ~TDB_SUSPEND;
 853                 break;
 854
 855         case PT_STEP:
 856         case PT_CONTINUE:
 857         case PT_TO_SCE:
 858         case PT_TO_SCX:
 859         case PT_SYSCALL:
 860         case PT_DETACH:
 861                 /* Zero means do not send any signal */
 862                 if (data < 0 || data > _SIG_MAXSIG) {
 863                         error = EINVAL;
 864                         break;
 865                 }
 866
 867                 switch (req) {
 868                 case PT_STEP:
 869                         error = ptrace_single_step(td2);
 870                         if (error)
 871                                 goto out;
 872                         break;
 873                 case PT_CONTINUE:
 874                 case PT_TO_SCE:
 875                 case PT_TO_SCX:
 876                 case PT_SYSCALL:
 877                         if (addr != (void *)1) {
 878                                 error = ptrace_set_pc(td2,
 879                                     (u_long)(uintfptr_t)addr);
 880                                 if (error)
 881                                         goto out;
 882                         }
 883                         switch (req) {
 884                         case PT_TO_SCE:
 885                                 p->p_stops |= S_PT_SCE;
 886                                 break;
 887                         case PT_TO_SCX:
 888                                 p->p_stops |= S_PT_SCX;
 889                                 break;
 890                         case PT_SYSCALL:
 891                                 p->p_stops |= S_PT_SCE | S_PT_SCX;
 892                                 break;
 893                         }
 894                         break;
 895                 case PT_DETACH:
 896                         /* reset process parent */
 897                         if (p->p_oppid != p->p_pptr->p_pid) {
 898                                 struct proc *pp;
 899
 900                                 PROC_LOCK(p->p_pptr);
 901                                 sigqueue_take(p->p_ksi);
 902                                 PROC_UNLOCK(p->p_pptr);
 903
 904                                 PROC_UNLOCK(p);
 905                                 pp = pfind(p->p_oppid);
 906                                 if (pp == NULL)
 907                                         pp = initproc;
 908                                 else
 909                                         PROC_UNLOCK(pp);
 910                                 PROC_LOCK(p);
 911                                 proc_reparent(p, pp);
 912                                 if (pp == initproc)
 913                                         p->p_sigparent = SIGCHLD;
 914                         }
 915                         p->p_flag &= ~(P_TRACED | P_WAITED);
 916                         p->p_oppid = 0;
 917
 918                         /* should we send SIGCHLD? */
 919                         /* childproc_continued(p); */
 920                         break;
 921                 }
 922
 923         sendsig:
 924                 if (proctree_locked) {
 925                         sx_xunlock(&proctree_lock);
 926                         proctree_locked = 0;
 927                 }
 928                 p->p_xstat = data;
 929                 p->p_xthread = NULL;
 930                 if ((p->p_flag & (P_STOPPED_SIG | P_STOPPED_TRACE)) != 0) {
 931                         /* deliver or queue signal */
 932                         td2->td_dbgflags &= ~TDB_XSIG;
 933                         td2->td_xsig = data;
 934
 935                         if (req == PT_DETACH) {
 936                                 struct thread *td3;
 937                                 FOREACH_THREAD_IN_PROC(p, td3) {
 938                                         td3->td_dbgflags &= ~TDB_SUSPEND;
 939                                 }
 940                         }
 941                         /*
 942                          * unsuspend all threads, to not let a thread run,
 943                          * you should use PT_SUSPEND to suspend it before
 944                          * continuing process.
 945                          */
 946                         PROC_SLOCK(p);
 947                         p->p_flag &= ~(P_STOPPED_TRACE|P_STOPPED_SIG|P_WAITED);
 948                         thread_unsuspend(p);
 949                         PROC_SUNLOCK(p);
 950                 } else {
 951                         if (data)
 952                                 psignal(p, data);
 953                 }
 954                 break;
 955
 956         case PT_WRITE_I:
 957         case PT_WRITE_D:
 958                 td2->td_dbgflags |= TDB_USERWR;
 959                 write = 1;
 960                 /* FALLTHROUGH */
 961         case PT_READ_I:
 962         case PT_READ_D:
 963                 PROC_UNLOCK(p);
 964                 tmp = 0;
 965                 /* write = 0 set above */
 966                 iov.iov_base = write ? (caddr_t)&data : (caddr_t)&tmp;
 967                 iov.iov_len = sizeof(int);
 968                 uio.uio_iov = &iov;
 969                 uio.uio_iovcnt = 1;
 970                 uio.uio_offset = (off_t)(uintptr_t)addr;
 971                 uio.uio_resid = sizeof(int);
 972                 uio.uio_segflg = UIO_SYSSPACE;  /* i.e.: the uap */
 973                 uio.uio_rw = write ? UIO_WRITE : UIO_READ;
 974                 uio.uio_td = td;
 975                 error = proc_rwmem(p, &uio);
 976                 if (uio.uio_resid != 0) {
 977                         /*
 978                          * XXX proc_rwmem() doesn't currently return ENOSPC,
 979                          * so I think write() can bogusly return 0.
 980                          * XXX what happens for short writes?  We don't want
 981                          * to write partial data.
 982                          * XXX proc_rwmem() returns EPERM for other invalid
 983                          * addresses.  Convert this to EINVAL.  Does this
 984                          * clobber returns of EPERM for other reasons?
 985                          */
 986                         if (error == 0 || error == ENOSPC || error == EPERM)
 987                                 error = EINVAL; /* EOF */
 988                 }
 989                 if (!write)
 990                         td->td_retval[0] = tmp;
 991                 PROC_LOCK(p);
 992                 break;
 993
 994         case PT_IO:
 995 #ifdef COMPAT_FREEBSD32
 996                 if (wrap32) {
 997                         piod32 = addr;
 998                         iov.iov_base = (void *)(uintptr_t)piod32->piod_addr;
 999                         iov.iov_len = piod32->piod_len;
1000                         uio.uio_offset = (off_t)(uintptr_t)piod32->piod_offs;
1001                         uio.uio_resid = piod32->piod_len;
1002                 } else
1003 #endif
1004                 {
1005                         piod = addr;
1006                         iov.iov_base = piod->piod_addr;
1007                         iov.iov_len = piod->piod_len;
1008                         uio.uio_offset = (off_t)(uintptr_t)piod->piod_offs;
1009                         uio.uio_resid = piod->piod_len;
1010                 }
1011                 uio.uio_iov = &iov;
1012                 uio.uio_iovcnt = 1;
1013                 uio.uio_segflg = UIO_USERSPACE;
1014                 uio.uio_td = td;
1015 #ifdef COMPAT_FREEBSD32
1016                 tmp = wrap32 ? piod32->piod_op : piod->piod_op;
1017 #else
1018                 tmp = piod->piod_op;
1019 #endif
1020                 switch (tmp) {
1021                 case PIOD_READ_D:
1022                 case PIOD_READ_I:
1023                         uio.uio_rw = UIO_READ;
1024                         break;
1025                 case PIOD_WRITE_D:
1026                 case PIOD_WRITE_I:
1027                         td2->td_dbgflags |= TDB_USERWR;
1028                         uio.uio_rw = UIO_WRITE;
1029                         break;
1030                 default:
1031                         error = EINVAL;
1032                         goto out;
1033                 }
1034                 PROC_UNLOCK(p);
1035                 error = proc_rwmem(p, &uio);
1036 #ifdef COMPAT_FREEBSD32
1037                 if (wrap32)
1038                         piod32->piod_len -= uio.uio_resid;
1039                 else
1040 #endif
1041                         piod->piod_len -= uio.uio_resid;
1042                 PROC_LOCK(p);
1043                 break;
1044
1045         case PT_KILL:
1046                 data = SIGKILL;
1047                 goto sendsig;   /* in PT_CONTINUE above */
1048
1049         case PT_SETREGS:
1050                 td2->td_dbgflags |= TDB_USERWR;
1051                 error = PROC_WRITE(regs, td2, addr);
1052                 break;
1053
1054         case PT_GETREGS:
1055                 error = PROC_READ(regs, td2, addr);
1056                 break;
1057
1058         case PT_SETFPREGS:
1059                 td2->td_dbgflags |= TDB_USERWR;
1060                 error = PROC_WRITE(fpregs, td2, addr);
1061                 break;
1062
1063         case PT_GETFPREGS:
1064                 error = PROC_READ(fpregs, td2, addr);
1065                 break;
1066
1067         case PT_SETDBREGS:
1068                 td2->td_dbgflags |= TDB_USERWR;
1069                 error = PROC_WRITE(dbregs, td2, addr);
1070                 break;
1071
1072         case PT_GETDBREGS:
1073                 error = PROC_READ(dbregs, td2, addr);
1074                 break;
1075
1076         case PT_LWPINFO:
1077                 if (data <= 0 ||
1078 #ifdef COMPAT_FREEBSD32
1079                     (!wrap32 && data > sizeof(*pl)) ||
1080                     (wrap32 && data > sizeof(*pl32))) {
1081 #else
1082                     data > sizeof(*pl)) {
1083 #endif
1084                         error = EINVAL;
1085                         break;
1086                 }
1087 #ifdef COMPAT_FREEBSD32
1088                 if (wrap32) {
1089                         pl = &plr;
1090                         pl32 = addr;
1091                 } else
1092 #endif
1093                 pl = addr;
1094                 pl->pl_lwpid = td2->td_tid;
1095                 pl->pl_flags = 0;
1096                 if (td2->td_dbgflags & TDB_XSIG) {
1097                         pl->pl_event = PL_EVENT_SIGNAL;
1098                         if (td2->td_dbgksi.ksi_signo != 0 &&
1099 #ifdef COMPAT_FREEBSD32
1100                             ((!wrap32 && data >= offsetof(struct ptrace_lwpinfo,
1101                             pl_siginfo) + sizeof(pl->pl_siginfo)) ||
1102                             (wrap32 && data >= offsetof(struct ptrace_lwpinfo32,
1103                             pl_siginfo) + sizeof(struct siginfo32)))
1104 #else
1105                             data >= offsetof(struct ptrace_lwpinfo, pl_siginfo)
1106                             + sizeof(pl->pl_siginfo)
1107 #endif
1108                         ){
1109                                 pl->pl_flags |= PL_FLAG_SI;
1110                                 pl->pl_siginfo = td2->td_dbgksi.ksi_info;
1111                         }
1112                 }
1113                 if ((pl->pl_flags & PL_FLAG_SI) == 0)
1114                         bzero(&pl->pl_siginfo, sizeof(pl->pl_siginfo));
1115                 if (td2->td_dbgflags & TDB_SCE)
1116                         pl->pl_flags |= PL_FLAG_SCE;
1117                 else if (td2->td_dbgflags & TDB_SCX)
1118                         pl->pl_flags |= PL_FLAG_SCX;
1119                 if (td2->td_dbgflags & TDB_EXEC)
1120                         pl->pl_flags |= PL_FLAG_EXEC;
1121                 pl->pl_sigmask = td2->td_sigmask;
1122                 pl->pl_siglist = td2->td_siglist;
1123                 strcpy(pl->pl_tdname, td2->td_name);
1124 #ifdef COMPAT_FREEBSD32
1125                 if (wrap32)
1126                         ptrace_lwpinfo_to32(pl, pl32);
1127 #endif
1128                 break;
1129
1130         case PT_GETNUMLWPS:
1131                 td->td_retval[0] = p->p_numthreads;
1132                 break;
1133
1134         case PT_GETLWPLIST:
1135                 if (data <= 0) {
1136                         error = EINVAL;
1137                         break;
1138                 }
1139                 num = imin(p->p_numthreads, data);
1140                 PROC_UNLOCK(p);
1141                 buf = malloc(num * sizeof(lwpid_t), M_TEMP, M_WAITOK);
1142                 tmp = 0;
1143                 PROC_LOCK(p);
1144                 FOREACH_THREAD_IN_PROC(p, td2) {
1145                         if (tmp >= num)
1146                                 break;
1147                         buf[tmp++] = td2->td_tid;
1148                 }
1149                 PROC_UNLOCK(p);
1150                 error = copyout(buf, addr, tmp * sizeof(lwpid_t));
1151                 free(buf, M_TEMP);
1152                 if (!error)
1153                         td->td_retval[0] = tmp;
1154                 PROC_LOCK(p);
1155                 break;
1156
1157         case PT_VM_TIMESTAMP:
1158                 td->td_retval[0] = p->p_vmspace->vm_map.timestamp;
1159                 break;
1160
1161         case PT_VM_ENTRY:
1162                 PROC_UNLOCK(p);
1163 #ifdef COMPAT_FREEBSD32
1164                 if (wrap32)
1165                         error = ptrace_vm_entry32(td, p, addr);
1166                 else
1167 #endif
1168                 error = ptrace_vm_entry(td, p, addr);
1169                 PROC_LOCK(p);
1170                 break;
1171
1172         default:
1173 #ifdef __HAVE_PTRACE_MACHDEP
1174                 if (req >= PT_FIRSTMACH) {
1175                         PROC_UNLOCK(p);
1176                         error = cpu_ptrace(td2, req, addr, data);
1177                         PROC_LOCK(p);
1178                 } else
1179 #endif
1180                         /* Unknown request. */
1181                         error = EINVAL;
1182                 break;
1183         }
1184
1185 out:
1186         /* Drop our hold on this process now that the request has completed. */
1187         _PRELE(p);
1188 fail:
1189         PROC_UNLOCK(p);
1190         if (proctree_locked)
1191                 sx_xunlock(&proctree_lock);
1192         return (error);
1193 }
1194 #undef PROC_READ
1195 #undef PROC_WRITE
1196
1197 /*
1198  * Stop a process because of a debugging event;
1199  * stay stopped until p->p_step is cleared
1200  * (cleared by PIOCCONT in procfs).
1201  */
1202 void
1203 stopevent(struct proc *p, unsigned int event, unsigned int val)
1204 {
1205
1206         PROC_LOCK_ASSERT(p, MA_OWNED);
1207         p->p_step = 1;
1208         do {
1209                 p->p_xstat = val;
1210                 p->p_xthread = NULL;
1211                 p->p_stype = event;     /* Which event caused the stop? */
1212                 wakeup(&p->p_stype);    /* Wake up any PIOCWAIT'ing procs */
1213                 msleep(&p->p_step, &p->p_mtx, PWAIT, "stopevent", 0);
1214         } while (p->p_step);
1215 }