sys/kern/sys_process.c

   1 /*-
   2  * Copyright (c) 1994, Sean Eric Fagan
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by Sean Eric Fagan.
  16  * 4. The name of the author may not be used to endorse or promote products
  17  *    derived from this software without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 #include <sys/cdefs.h>
  33 __FBSDID("$FreeBSD$");
  34
  35 #include "opt_compat.h"
  36
  37 #include <sys/param.h>
  38 #include <sys/systm.h>
  39 #include <sys/lock.h>
  40 #include <sys/mutex.h>
  41 #include <sys/syscallsubr.h>
  42 #include <sys/sysent.h>
  43 #include <sys/sysproto.h>
  44 #include <sys/proc.h>
  45 #include <sys/vnode.h>
  46 #include <sys/ptrace.h>
  47 #include <sys/sx.h>
  48 #include <sys/malloc.h>
  49 #include <sys/signalvar.h>
  50
  51 #include <machine/reg.h>
  52
  53 #include <security/audit/audit.h>
  54
  55 #include <vm/vm.h>
  56 #include <vm/pmap.h>
  57 #include <vm/vm_extern.h>
  58 #include <vm/vm_map.h>
  59 #include <vm/vm_kern.h>
  60 #include <vm/vm_object.h>
  61 #include <vm/vm_page.h>
  62 #include <vm/vm_param.h>
  63
  64 #ifdef COMPAT_FREEBSD32
  65 #include <sys/procfs.h>
  66 #include <compat/freebsd32/freebsd32_signal.h>
  67
  68 struct ptrace_io_desc32 {
  69         int             piod_op;
  70         uint32_t        piod_offs;
  71         uint32_t        piod_addr;
  72         uint32_t        piod_len;
  73 };
  74
  75 struct ptrace_vm_entry32 {
  76         int             pve_entry;
  77         int             pve_timestamp;
  78         uint32_t        pve_start;
  79         uint32_t        pve_end;
  80         uint32_t        pve_offset;
  81         u_int           pve_prot;
  82         u_int           pve_pathlen;
  83         int32_t         pve_fileid;
  84         u_int           pve_fsid;
  85         uint32_t        pve_path;
  86 };
  87
  88 struct ptrace_lwpinfo32 {
  89         lwpid_t pl_lwpid;       /* LWP described. */
  90         int     pl_event;       /* Event that stopped the LWP. */
  91         int     pl_flags;       /* LWP flags. */
  92         sigset_t        pl_sigmask;     /* LWP signal mask */
  93         sigset_t        pl_siglist;     /* LWP pending signal */
  94         struct siginfo32 pl_siginfo;    /* siginfo for signal */
  95         char    pl_tdname[MAXCOMLEN + 1];       /* LWP name. */
  96         int     pl_child_pid;           /* New child pid */
  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;
 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                         vn_lock(vp, LK_SHARED | LK_RETRY);
 415                         if (VOP_GETATTR(vp, &vattr, td->td_ucred) == 0) {
 416                                 pve->pve_fileid = vattr.va_fileid;
 417                                 pve->pve_fsid = vattr.va_fsid;
 418                         }
 419                         vput(vp);
 420
 421                         if (fullpath != NULL) {
 422                                 pve->pve_pathlen = strlen(fullpath) + 1;
 423                                 if (pve->pve_pathlen <= pathlen) {
 424                                         error = copyout(fullpath, pve->pve_path,
 425                                             pve->pve_pathlen);
 426                                 } else
 427                                         error = ENAMETOOLONG;
 428                         }
 429                         if (freepath != NULL)
 430                                 free(freepath, M_TEMP);
 431                 }
 432         }
 433
 434         return (error);
 435 }
 436
 437 #ifdef COMPAT_FREEBSD32
 438 static int
 439 ptrace_vm_entry32(struct thread *td, struct proc *p,
 440     struct ptrace_vm_entry32 *pve32)
 441 {
 442         struct ptrace_vm_entry pve;
 443         int error;
 444
 445         pve.pve_entry = pve32->pve_entry;
 446         pve.pve_pathlen = pve32->pve_pathlen;
 447         pve.pve_path = (void *)(uintptr_t)pve32->pve_path;
 448
 449         error = ptrace_vm_entry(td, p, &pve);
 450         if (error == 0) {
 451                 pve32->pve_entry = pve.pve_entry;
 452                 pve32->pve_timestamp = pve.pve_timestamp;
 453                 pve32->pve_start = pve.pve_start;
 454                 pve32->pve_end = pve.pve_end;
 455                 pve32->pve_offset = pve.pve_offset;
 456                 pve32->pve_prot = pve.pve_prot;
 457                 pve32->pve_fileid = pve.pve_fileid;
 458                 pve32->pve_fsid = pve.pve_fsid;
 459         }
 460
 461         pve32->pve_pathlen = pve.pve_pathlen;
 462         return (error);
 463 }
 464
 465 static void
 466 ptrace_lwpinfo_to32(const struct ptrace_lwpinfo *pl,
 467     struct ptrace_lwpinfo32 *pl32)
 468 {
 469
 470         pl32->pl_lwpid = pl->pl_lwpid;
 471         pl32->pl_event = pl->pl_event;
 472         pl32->pl_flags = pl->pl_flags;
 473         pl32->pl_sigmask = pl->pl_sigmask;
 474         pl32->pl_siglist = pl->pl_siglist;
 475         siginfo_to_siginfo32(&pl->pl_siginfo, &pl32->pl_siginfo);
 476         strcpy(pl32->pl_tdname, pl->pl_tdname);
 477         pl32->pl_child_pid = pl->pl_child_pid;
 478 }
 479 #endif /* COMPAT_FREEBSD32 */
 480
 481 /*
 482  * Process debugging system call.
 483  */
 484 #ifndef _SYS_SYSPROTO_H_
 485 struct ptrace_args {
 486         int     req;
 487         pid_t   pid;
 488         caddr_t addr;
 489         int     data;
 490 };
 491 #endif
 492
 493 #ifdef COMPAT_FREEBSD32
 494 /*
 495  * This CPP subterfuge is to try and reduce the number of ifdefs in
 496  * the body of the code.
 497  *   COPYIN(uap->addr, &r.reg, sizeof r.reg);
 498  * becomes either:
 499  *   copyin(uap->addr, &r.reg, sizeof r.reg);
 500  * or
 501  *   copyin(uap->addr, &r.reg32, sizeof r.reg32);
 502  * .. except this is done at runtime.
 503  */
 504 #define COPYIN(u, k, s)         wrap32 ? \
 505         copyin(u, k ## 32, s ## 32) : \
 506         copyin(u, k, s)
 507 #define COPYOUT(k, u, s)        wrap32 ? \
 508         copyout(k ## 32, u, s ## 32) : \
 509         copyout(k, u, s)
 510 #else
 511 #define COPYIN(u, k, s)         copyin(u, k, s)
 512 #define COPYOUT(k, u, s)        copyout(k, u, s)
 513 #endif
 514 int
 515 sys_ptrace(struct thread *td, struct ptrace_args *uap)
 516 {
 517         /*
 518          * XXX this obfuscation is to reduce stack usage, but the register
 519          * structs may be too large to put on the stack anyway.
 520          */
 521         union {
 522                 struct ptrace_io_desc piod;
 523                 struct ptrace_lwpinfo pl;
 524                 struct ptrace_vm_entry pve;
 525                 struct dbreg dbreg;
 526                 struct fpreg fpreg;
 527                 struct reg reg;
 528 #ifdef COMPAT_FREEBSD32
 529                 struct dbreg32 dbreg32;
 530                 struct fpreg32 fpreg32;
 531                 struct reg32 reg32;
 532                 struct ptrace_io_desc32 piod32;
 533                 struct ptrace_lwpinfo32 pl32;
 534                 struct ptrace_vm_entry32 pve32;
 535 #endif
 536         } r;
 537         void *addr;
 538         int error = 0;
 539 #ifdef COMPAT_FREEBSD32
 540         int wrap32 = 0;
 541
 542         if (SV_CURPROC_FLAG(SV_ILP32))
 543                 wrap32 = 1;
 544 #endif
 545         AUDIT_ARG_PID(uap->pid);
 546         AUDIT_ARG_CMD(uap->req);
 547         AUDIT_ARG_VALUE(uap->data);
 548         addr = &r;
 549         switch (uap->req) {
 550         case PT_GETREGS:
 551         case PT_GETFPREGS:
 552         case PT_GETDBREGS:
 553         case PT_LWPINFO:
 554                 break;
 555         case PT_SETREGS:
 556                 error = COPYIN(uap->addr, &r.reg, sizeof r.reg);
 557                 break;
 558         case PT_SETFPREGS:
 559                 error = COPYIN(uap->addr, &r.fpreg, sizeof r.fpreg);
 560                 break;
 561         case PT_SETDBREGS:
 562                 error = COPYIN(uap->addr, &r.dbreg, sizeof r.dbreg);
 563                 break;
 564         case PT_IO:
 565                 error = COPYIN(uap->addr, &r.piod, sizeof r.piod);
 566                 break;
 567         case PT_VM_ENTRY:
 568                 error = COPYIN(uap->addr, &r.pve, sizeof r.pve);
 569                 break;
 570         default:
 571                 addr = uap->addr;
 572                 break;
 573         }
 574         if (error)
 575                 return (error);
 576
 577         error = kern_ptrace(td, uap->req, uap->pid, addr, uap->data);
 578         if (error)
 579                 return (error);
 580
 581         switch (uap->req) {
 582         case PT_VM_ENTRY:
 583                 error = COPYOUT(&r.pve, uap->addr, sizeof r.pve);
 584                 break;
 585         case PT_IO:
 586                 error = COPYOUT(&r.piod, uap->addr, sizeof r.piod);
 587                 break;
 588         case PT_GETREGS:
 589                 error = COPYOUT(&r.reg, uap->addr, sizeof r.reg);
 590                 break;
 591         case PT_GETFPREGS:
 592                 error = COPYOUT(&r.fpreg, uap->addr, sizeof r.fpreg);
 593                 break;
 594         case PT_GETDBREGS:
 595                 error = COPYOUT(&r.dbreg, uap->addr, sizeof r.dbreg);
 596                 break;
 597         case PT_LWPINFO:
 598                 error = copyout(&r.pl, uap->addr, uap->data);
 599                 break;
 600         }
 601
 602         return (error);
 603 }
 604 #undef COPYIN
 605 #undef COPYOUT
 606
 607 #ifdef COMPAT_FREEBSD32
 608 /*
 609  *   PROC_READ(regs, td2, addr);
 610  * becomes either:
 611  *   proc_read_regs(td2, addr);
 612  * or
 613  *   proc_read_regs32(td2, addr);
 614  * .. except this is done at runtime.  There is an additional
 615  * complication in that PROC_WRITE disallows 32 bit consumers
 616  * from writing to 64 bit address space targets.
 617  */
 618 #define PROC_READ(w, t, a)      wrap32 ? \
 619         proc_read_ ## w ## 32(t, a) : \
 620         proc_read_ ## w (t, a)
 621 #define PROC_WRITE(w, t, a)     wrap32 ? \
 622         (safe ? proc_write_ ## w ## 32(t, a) : EINVAL ) : \
 623         proc_write_ ## w (t, a)
 624 #else
 625 #define PROC_READ(w, t, a)      proc_read_ ## w (t, a)
 626 #define PROC_WRITE(w, t, a)     proc_write_ ## w (t, a)
 627 #endif
 628
 629 int
 630 kern_ptrace(struct thread *td, int req, pid_t pid, void *addr, int data)
 631 {
 632         struct iovec iov;
 633         struct uio uio;
 634         struct proc *curp, *p, *pp;
 635         struct thread *td2 = NULL, *td3;
 636         struct ptrace_io_desc *piod = NULL;
 637         struct ptrace_lwpinfo *pl;
 638         int error, write, tmp, num;
 639         int proctree_locked = 0;
 640         lwpid_t tid = 0, *buf;
 641 #ifdef COMPAT_FREEBSD32
 642         int wrap32 = 0, safe = 0;
 643         struct ptrace_io_desc32 *piod32 = NULL;
 644         struct ptrace_lwpinfo32 *pl32 = NULL;
 645         struct ptrace_lwpinfo plr;
 646 #endif
 647
 648         curp = td->td_proc;
 649
 650         /* Lock proctree before locking the process. */
 651         switch (req) {
 652         case PT_TRACE_ME:
 653         case PT_ATTACH:
 654         case PT_STEP:
 655         case PT_CONTINUE:
 656         case PT_TO_SCE:
 657         case PT_TO_SCX:
 658         case PT_SYSCALL:
 659         case PT_FOLLOW_FORK:
 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 (SV_PROC_FLAG(td2->td_proc, 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                 if (p->p_flag & P_PPWAIT)
 825                         p->p_flag |= P_PPTRACE;
 826                 p->p_oppid = p->p_pptr->p_pid;
 827                 break;
 828
 829         case PT_ATTACH:
 830                 /* security check done above */
 831                 /*
 832                  * It would be nice if the tracing relationship was separate
 833                  * from the parent relationship but that would require
 834                  * another set of links in the proc struct or for "wait"
 835                  * to scan the entire proc table.  To make life easier,
 836                  * we just re-parent the process we're trying to trace.
 837                  * The old parent is remembered so we can put things back
 838                  * on a "detach".
 839                  */
 840                 p->p_flag |= P_TRACED;
 841                 p->p_oppid = p->p_pptr->p_pid;
 842                 if (p->p_pptr != td->td_proc) {
 843                         proc_reparent(p, td->td_proc);
 844                 }
 845                 data = SIGSTOP;
 846                 goto sendsig;   /* in PT_CONTINUE below */
 847
 848         case PT_CLEARSTEP:
 849                 error = ptrace_clear_single_step(td2);
 850                 break;
 851
 852         case PT_SETSTEP:
 853                 error = ptrace_single_step(td2);
 854                 break;
 855
 856         case PT_SUSPEND:
 857                 td2->td_dbgflags |= TDB_SUSPEND;
 858                 thread_lock(td2);
 859                 td2->td_flags |= TDF_NEEDSUSPCHK;
 860                 thread_unlock(td2);
 861                 break;
 862
 863         case PT_RESUME:
 864                 td2->td_dbgflags &= ~TDB_SUSPEND;
 865                 break;
 866
 867         case PT_FOLLOW_FORK:
 868                 if (data)
 869                         p->p_flag |= P_FOLLOWFORK;
 870                 else
 871                         p->p_flag &= ~P_FOLLOWFORK;
 872                 break;
 873
 874         case PT_STEP:
 875         case PT_CONTINUE:
 876         case PT_TO_SCE:
 877         case PT_TO_SCX:
 878         case PT_SYSCALL:
 879         case PT_DETACH:
 880                 /* Zero means do not send any signal */
 881                 if (data < 0 || data > _SIG_MAXSIG) {
 882                         error = EINVAL;
 883                         break;
 884                 }
 885
 886                 switch (req) {
 887                 case PT_STEP:
 888                         error = ptrace_single_step(td2);
 889                         if (error)
 890                                 goto out;
 891                         break;
 892                 case PT_CONTINUE:
 893                 case PT_TO_SCE:
 894                 case PT_TO_SCX:
 895                 case PT_SYSCALL:
 896                         if (addr != (void *)1) {
 897                                 error = ptrace_set_pc(td2,
 898                                     (u_long)(uintfptr_t)addr);
 899                                 if (error)
 900                                         goto out;
 901                         }
 902                         switch (req) {
 903                         case PT_TO_SCE:
 904                                 p->p_stops |= S_PT_SCE;
 905                                 break;
 906                         case PT_TO_SCX:
 907                                 p->p_stops |= S_PT_SCX;
 908                                 break;
 909                         case PT_SYSCALL:
 910                                 p->p_stops |= S_PT_SCE | S_PT_SCX;
 911                                 break;
 912                         }
 913                         break;
 914                 case PT_DETACH:
 915                         /* reset process parent */
 916                         if (p->p_oppid != p->p_pptr->p_pid) {
 917                                 struct proc *pp;
 918
 919                                 PROC_LOCK(p->p_pptr);
 920                                 sigqueue_take(p->p_ksi);
 921                                 PROC_UNLOCK(p->p_pptr);
 922
 923                                 PROC_UNLOCK(p);
 924                                 pp = pfind(p->p_oppid);
 925                                 if (pp == NULL)
 926                                         pp = initproc;
 927                                 else
 928                                         PROC_UNLOCK(pp);
 929                                 PROC_LOCK(p);
 930                                 proc_reparent(p, pp);
 931                                 if (pp == initproc)
 932                                         p->p_sigparent = SIGCHLD;
 933                         }
 934                         p->p_oppid = 0;
 935                         p->p_flag &= ~(P_TRACED | P_WAITED | P_FOLLOWFORK);
 936
 937                         /* should we send SIGCHLD? */
 938                         /* childproc_continued(p); */
 939                         break;
 940                 }
 941
 942         sendsig:
 943                 if (proctree_locked) {
 944                         sx_xunlock(&proctree_lock);
 945                         proctree_locked = 0;
 946                 }
 947                 p->p_xstat = data;
 948                 p->p_xthread = NULL;
 949                 if ((p->p_flag & (P_STOPPED_SIG | P_STOPPED_TRACE)) != 0) {
 950                         /* deliver or queue signal */
 951                         td2->td_dbgflags &= ~TDB_XSIG;
 952                         td2->td_xsig = data;
 953
 954                         if (req == PT_DETACH) {
 955                                 FOREACH_THREAD_IN_PROC(p, td3)
 956                                         td3->td_dbgflags &= ~TDB_SUSPEND;
 957                         }
 958                         /*
 959                          * unsuspend all threads, to not let a thread run,
 960                          * you should use PT_SUSPEND to suspend it before
 961                          * continuing process.
 962                          */
 963                         PROC_SLOCK(p);
 964                         p->p_flag &= ~(P_STOPPED_TRACE|P_STOPPED_SIG|P_WAITED);
 965                         thread_unsuspend(p);
 966                         PROC_SUNLOCK(p);
 967                         if (req == PT_ATTACH)
 968                                 kern_psignal(p, data);
 969                 } else {
 970                         if (data)
 971                                 kern_psignal(p, data);
 972                 }
 973                 break;
 974
 975         case PT_WRITE_I:
 976         case PT_WRITE_D:
 977                 td2->td_dbgflags |= TDB_USERWR;
 978                 write = 1;
 979                 /* FALLTHROUGH */
 980         case PT_READ_I:
 981         case PT_READ_D:
 982                 PROC_UNLOCK(p);
 983                 tmp = 0;
 984                 /* write = 0 set above */
 985                 iov.iov_base = write ? (caddr_t)&data : (caddr_t)&tmp;
 986                 iov.iov_len = sizeof(int);
 987                 uio.uio_iov = &iov;
 988                 uio.uio_iovcnt = 1;
 989                 uio.uio_offset = (off_t)(uintptr_t)addr;
 990                 uio.uio_resid = sizeof(int);
 991                 uio.uio_segflg = UIO_SYSSPACE;  /* i.e.: the uap */
 992                 uio.uio_rw = write ? UIO_WRITE : UIO_READ;
 993                 uio.uio_td = td;
 994                 error = proc_rwmem(p, &uio);
 995                 if (uio.uio_resid != 0) {
 996                         /*
 997                          * XXX proc_rwmem() doesn't currently return ENOSPC,
 998                          * so I think write() can bogusly return 0.
 999                          * XXX what happens for short writes?  We don't want
1000                          * to write partial data.
1001                          * XXX proc_rwmem() returns EPERM for other invalid
1002                          * addresses.  Convert this to EINVAL.  Does this
1003                          * clobber returns of EPERM for other reasons?
1004                          */
1005                         if (error == 0 || error == ENOSPC || error == EPERM)
1006                                 error = EINVAL; /* EOF */
1007                 }
1008                 if (!write)
1009                         td->td_retval[0] = tmp;
1010                 PROC_LOCK(p);
1011                 break;
1012
1013         case PT_IO:
1014 #ifdef COMPAT_FREEBSD32
1015                 if (wrap32) {
1016                         piod32 = addr;
1017                         iov.iov_base = (void *)(uintptr_t)piod32->piod_addr;
1018                         iov.iov_len = piod32->piod_len;
1019                         uio.uio_offset = (off_t)(uintptr_t)piod32->piod_offs;
1020                         uio.uio_resid = piod32->piod_len;
1021                 } else
1022 #endif
1023                 {
1024                         piod = addr;
1025                         iov.iov_base = piod->piod_addr;
1026                         iov.iov_len = piod->piod_len;
1027                         uio.uio_offset = (off_t)(uintptr_t)piod->piod_offs;
1028                         uio.uio_resid = piod->piod_len;
1029                 }
1030                 uio.uio_iov = &iov;
1031                 uio.uio_iovcnt = 1;
1032                 uio.uio_segflg = UIO_USERSPACE;
1033                 uio.uio_td = td;
1034 #ifdef COMPAT_FREEBSD32
1035                 tmp = wrap32 ? piod32->piod_op : piod->piod_op;
1036 #else
1037                 tmp = piod->piod_op;
1038 #endif
1039                 switch (tmp) {
1040                 case PIOD_READ_D:
1041                 case PIOD_READ_I:
1042                         uio.uio_rw = UIO_READ;
1043                         break;
1044                 case PIOD_WRITE_D:
1045                 case PIOD_WRITE_I:
1046                         td2->td_dbgflags |= TDB_USERWR;
1047                         uio.uio_rw = UIO_WRITE;
1048                         break;
1049                 default:
1050                         error = EINVAL;
1051                         goto out;
1052                 }
1053                 PROC_UNLOCK(p);
1054                 error = proc_rwmem(p, &uio);
1055 #ifdef COMPAT_FREEBSD32
1056                 if (wrap32)
1057                         piod32->piod_len -= uio.uio_resid;
1058                 else
1059 #endif
1060                         piod->piod_len -= uio.uio_resid;
1061                 PROC_LOCK(p);
1062                 break;
1063
1064         case PT_KILL:
1065                 data = SIGKILL;
1066                 goto sendsig;   /* in PT_CONTINUE above */
1067
1068         case PT_SETREGS:
1069                 td2->td_dbgflags |= TDB_USERWR;
1070                 error = PROC_WRITE(regs, td2, addr);
1071                 break;
1072
1073         case PT_GETREGS:
1074                 error = PROC_READ(regs, td2, addr);
1075                 break;
1076
1077         case PT_SETFPREGS:
1078                 td2->td_dbgflags |= TDB_USERWR;
1079                 error = PROC_WRITE(fpregs, td2, addr);
1080                 break;
1081
1082         case PT_GETFPREGS:
1083                 error = PROC_READ(fpregs, td2, addr);
1084                 break;
1085
1086         case PT_SETDBREGS:
1087                 td2->td_dbgflags |= TDB_USERWR;
1088                 error = PROC_WRITE(dbregs, td2, addr);
1089                 break;
1090
1091         case PT_GETDBREGS:
1092                 error = PROC_READ(dbregs, td2, addr);
1093                 break;
1094
1095         case PT_LWPINFO:
1096                 if (data <= 0 ||
1097 #ifdef COMPAT_FREEBSD32
1098                     (!wrap32 && data > sizeof(*pl)) ||
1099                     (wrap32 && data > sizeof(*pl32))) {
1100 #else
1101                     data > sizeof(*pl)) {
1102 #endif
1103                         error = EINVAL;
1104                         break;
1105                 }
1106 #ifdef COMPAT_FREEBSD32
1107                 if (wrap32) {
1108                         pl = &plr;
1109                         pl32 = addr;
1110                 } else
1111 #endif
1112                 pl = addr;
1113                 pl->pl_lwpid = td2->td_tid;
1114                 pl->pl_event = PL_EVENT_NONE;
1115                 pl->pl_flags = 0;
1116                 if (td2->td_dbgflags & TDB_XSIG) {
1117                         pl->pl_event = PL_EVENT_SIGNAL;
1118                         if (td2->td_dbgksi.ksi_signo != 0 &&
1119 #ifdef COMPAT_FREEBSD32
1120                             ((!wrap32 && data >= offsetof(struct ptrace_lwpinfo,
1121                             pl_siginfo) + sizeof(pl->pl_siginfo)) ||
1122                             (wrap32 && data >= offsetof(struct ptrace_lwpinfo32,
1123                             pl_siginfo) + sizeof(struct siginfo32)))
1124 #else
1125                             data >= offsetof(struct ptrace_lwpinfo, pl_siginfo)
1126                             + sizeof(pl->pl_siginfo)
1127 #endif
1128                         ){
1129                                 pl->pl_flags |= PL_FLAG_SI;
1130                                 pl->pl_siginfo = td2->td_dbgksi.ksi_info;
1131                         }
1132                 }
1133                 if ((pl->pl_flags & PL_FLAG_SI) == 0)
1134                         bzero(&pl->pl_siginfo, sizeof(pl->pl_siginfo));
1135                 if (td2->td_dbgflags & TDB_SCE)
1136                         pl->pl_flags |= PL_FLAG_SCE;
1137                 else if (td2->td_dbgflags & TDB_SCX)
1138                         pl->pl_flags |= PL_FLAG_SCX;
1139                 if (td2->td_dbgflags & TDB_EXEC)
1140                         pl->pl_flags |= PL_FLAG_EXEC;
1141                 if (td2->td_dbgflags & TDB_FORK) {
1142                         pl->pl_flags |= PL_FLAG_FORKED;
1143                         pl->pl_child_pid = td2->td_dbg_forked;
1144                 }
1145                 if (td2->td_dbgflags & TDB_CHILD)
1146                         pl->pl_flags |= PL_FLAG_CHILD;
1147                 pl->pl_sigmask = td2->td_sigmask;
1148                 pl->pl_siglist = td2->td_siglist;
1149                 strcpy(pl->pl_tdname, td2->td_name);
1150 #ifdef COMPAT_FREEBSD32
1151                 if (wrap32)
1152                         ptrace_lwpinfo_to32(pl, pl32);
1153 #endif
1154                 break;
1155
1156         case PT_GETNUMLWPS:
1157                 td->td_retval[0] = p->p_numthreads;
1158                 break;
1159
1160         case PT_GETLWPLIST:
1161                 if (data <= 0) {
1162                         error = EINVAL;
1163                         break;
1164                 }
1165                 num = imin(p->p_numthreads, data);
1166                 PROC_UNLOCK(p);
1167                 buf = malloc(num * sizeof(lwpid_t), M_TEMP, M_WAITOK);
1168                 tmp = 0;
1169                 PROC_LOCK(p);
1170                 FOREACH_THREAD_IN_PROC(p, td2) {
1171                         if (tmp >= num)
1172                                 break;
1173                         buf[tmp++] = td2->td_tid;
1174                 }
1175                 PROC_UNLOCK(p);
1176                 error = copyout(buf, addr, tmp * sizeof(lwpid_t));
1177                 free(buf, M_TEMP);
1178                 if (!error)
1179                         td->td_retval[0] = tmp;
1180                 PROC_LOCK(p);
1181                 break;
1182
1183         case PT_VM_TIMESTAMP:
1184                 td->td_retval[0] = p->p_vmspace->vm_map.timestamp;
1185                 break;
1186
1187         case PT_VM_ENTRY:
1188                 PROC_UNLOCK(p);
1189 #ifdef COMPAT_FREEBSD32
1190                 if (wrap32)
1191                         error = ptrace_vm_entry32(td, p, addr);
1192                 else
1193 #endif
1194                 error = ptrace_vm_entry(td, p, addr);
1195                 PROC_LOCK(p);
1196                 break;
1197
1198         default:
1199 #ifdef __HAVE_PTRACE_MACHDEP
1200                 if (req >= PT_FIRSTMACH) {
1201                         PROC_UNLOCK(p);
1202                         error = cpu_ptrace(td2, req, addr, data);
1203                         PROC_LOCK(p);
1204                 } else
1205 #endif
1206                         /* Unknown request. */
1207                         error = EINVAL;
1208                 break;
1209         }
1210
1211 out:
1212         /* Drop our hold on this process now that the request has completed. */
1213         _PRELE(p);
1214 fail:
1215         PROC_UNLOCK(p);
1216         if (proctree_locked)
1217                 sx_xunlock(&proctree_lock);
1218         return (error);
1219 }
1220 #undef PROC_READ
1221 #undef PROC_WRITE
1222
1223 /*
1224  * Stop a process because of a debugging event;
1225  * stay stopped until p->p_step is cleared
1226  * (cleared by PIOCCONT in procfs).
1227  */
1228 void
1229 stopevent(struct proc *p, unsigned int event, unsigned int val)
1230 {
1231
1232         PROC_LOCK_ASSERT(p, MA_OWNED);
1233         p->p_step = 1;
1234         do {
1235                 p->p_xstat = val;
1236                 p->p_xthread = NULL;
1237                 p->p_stype = event;     /* Which event caused the stop? */
1238                 wakeup(&p->p_stype);    /* Wake up any PIOCWAIT'ing procs */
1239                 msleep(&p->p_step, &p->p_mtx, PWAIT, "stopevent", 0);
1240         } while (p->p_step);
1241 }