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 * $FreeBSD$ 32 */ 33 34 #include <sys/param.h> 35 #include <sys/systm.h> 36 #include <sys/sysproto.h> 37 #include <sys/proc.h> 38 #include <sys/vnode.h> 39 #include <sys/ptrace.h> 40 #include <sys/sx.h> 41 42 #include <machine/reg.h> 43 #include <vm/vm.h> 44 #include <sys/lock.h> 45 #include <vm/pmap.h> 46 #include <vm/vm_map.h> 47 #include <vm/vm_page.h> 48 49 #include <sys/user.h> 50 #include <miscfs/procfs/procfs.h> 51 52 /* use the equivalent procfs code */ 53 #if 0 54 static int 55 pread (struct proc *procp, unsigned int addr, unsigned int *retval) { 56 int rv; 57 vm_map_t map, tmap; 58 vm_object_t object; 59 vm_offset_t kva = 0; 60 int page_offset; /* offset into page */ 61 vm_offset_t pageno; /* page number */ 62 vm_map_entry_t out_entry; 63 vm_prot_t out_prot; 64 boolean_t wired; 65 vm_pindex_t pindex; 66 67 /* Map page into kernel space */ 68 69 map = &procp->p_vmspace->vm_map; 70 71 page_offset = addr - trunc_page(addr); 72 pageno = trunc_page(addr); 73 74 tmap = map; 75 rv = vm_map_lookup (&tmap, pageno, VM_PROT_READ, &out_entry, 76 &object, &pindex, &out_prot, &wired); 77 78 if (rv != KERN_SUCCESS) 79 return EINVAL; 80 81 vm_map_lookup_done (tmap, out_entry); 82 83 /* Find space in kernel_map for the page we're interested in */ 84 rv = vm_map_find (kernel_map, object, IDX_TO_OFF(pindex), 85 &kva, PAGE_SIZE, 0, VM_PROT_ALL, VM_PROT_ALL, 0); 86 87 if (!rv) { 88 vm_object_reference (object); 89 90 rv = vm_map_pageable (kernel_map, kva, kva + PAGE_SIZE, 0); 91 if (!rv) { 92 *retval = 0; 93 bcopy ((caddr_t)kva + page_offset, 94 retval, sizeof *retval); 95 } 96 vm_map_remove (kernel_map, kva, kva + PAGE_SIZE); 97 } 98 99 return rv; 100 } 101 102 static int 103 pwrite (struct proc *procp, unsigned int addr, unsigned int datum) { 104 int rv; 105 vm_map_t map, tmap; 106 vm_object_t object; 107 vm_offset_t kva = 0; 108 int page_offset; /* offset into page */ 109 vm_offset_t pageno; /* page number */ 110 vm_map_entry_t out_entry; 111 vm_prot_t out_prot; 112 boolean_t wired; 113 vm_pindex_t pindex; 114 boolean_t fix_prot = 0; 115 116 /* Map page into kernel space */ 117 118 map = &procp->p_vmspace->vm_map; 119 120 page_offset = addr - trunc_page(addr); 121 pageno = trunc_page(addr); 122 123 /* 124 * Check the permissions for the area we're interested in. 125 */ 126 127 if (vm_map_check_protection (map, pageno, pageno + PAGE_SIZE, 128 VM_PROT_WRITE) == FALSE) { 129 /* 130 * If the page was not writable, we make it so. 131 * XXX It is possible a page may *not* be read/executable, 132 * if a process changes that! 133 */ 134 fix_prot = 1; 135 /* The page isn't writable, so let's try making it so... */ 136 if ((rv = vm_map_protect (map, pageno, pageno + PAGE_SIZE, 137 VM_PROT_ALL, 0)) != KERN_SUCCESS) 138 return EFAULT; /* I guess... */ 139 } 140 141 /* 142 * Now we need to get the page. out_entry, out_prot, wired, and 143 * single_use aren't used. One would think the vm code would be 144 * a *bit* nicer... We use tmap because vm_map_lookup() can 145 * change the map argument. 146 */ 147 148 tmap = map; 149 rv = vm_map_lookup (&tmap, pageno, VM_PROT_WRITE, &out_entry, 150 &object, &pindex, &out_prot, &wired); 151 if (rv != KERN_SUCCESS) { 152 return EINVAL; 153 } 154 155 /* 156 * Okay, we've got the page. Let's release tmap. 157 */ 158 159 vm_map_lookup_done (tmap, out_entry); 160 161 /* 162 * Fault the page in... 163 */ 164 165 rv = vm_fault(map, pageno, VM_PROT_WRITE|VM_PROT_READ, FALSE); 166 if (rv != KERN_SUCCESS) 167 return EFAULT; 168 169 /* Find space in kernel_map for the page we're interested in */ 170 rv = vm_map_find (kernel_map, object, IDX_TO_OFF(pindex), 171 &kva, PAGE_SIZE, 0, 172 VM_PROT_ALL, VM_PROT_ALL, 0); 173 if (!rv) { 174 vm_object_reference (object); 175 176 rv = vm_map_pageable (kernel_map, kva, kva + PAGE_SIZE, 0); 177 if (!rv) { 178 bcopy (&datum, (caddr_t)kva + page_offset, sizeof datum); 179 } 180 vm_map_remove (kernel_map, kva, kva + PAGE_SIZE); 181 } 182 183 if (fix_prot) 184 vm_map_protect (map, pageno, pageno + PAGE_SIZE, 185 VM_PROT_READ|VM_PROT_EXECUTE, 0); 186 return rv; 187 } 188 #endif 189 190 /* 191 * Process debugging system call. 192 */ 193 #ifndef _SYS_SYSPROTO_H_ 194 struct ptrace_args { 195 int req; 196 pid_t pid; 197 caddr_t addr; 198 int data; 199 }; 200 #endif 201 202 int 203 ptrace(curp, uap) 204 struct proc *curp; 205 struct ptrace_args *uap; 206 { 207 struct proc *p; 208 struct iovec iov; 209 struct uio uio; 210 int error = 0; 211 int write; 212 213 write = 0; 214 if (uap->req == PT_TRACE_ME) 215 p = curp; 216 else { 217 if ((p = pfind(uap->pid)) == NULL) 218 return ESRCH; 219 } 220 if (p_can(curp, p, P_CAN_SEE, NULL)) 221 return (ESRCH); 222 223 /* 224 * Permissions check 225 */ 226 switch (uap->req) { 227 case PT_TRACE_ME: 228 /* Always legal. */ 229 break; 230 231 case PT_ATTACH: 232 /* Self */ 233 if (p->p_pid == curp->p_pid) 234 return EINVAL; 235 236 /* Already traced */ 237 PROC_LOCK(p); 238 if (p->p_flag & P_TRACED) { 239 PROC_UNLOCK(p); 240 return EBUSY; 241 } 242 PROC_UNLOCK(p); 243 244 if ((error = p_can(curp, p, P_CAN_DEBUG, NULL))) 245 return error; 246 247 /* OK */ 248 break; 249 250 case PT_READ_I: 251 case PT_READ_D: 252 case PT_READ_U: 253 case PT_WRITE_I: 254 case PT_WRITE_D: 255 case PT_WRITE_U: 256 case PT_CONTINUE: 257 case PT_KILL: 258 case PT_STEP: 259 case PT_DETACH: 260 #ifdef PT_GETREGS 261 case PT_GETREGS: 262 #endif 263 #ifdef PT_SETREGS 264 case PT_SETREGS: 265 #endif 266 #ifdef PT_GETFPREGS 267 case PT_GETFPREGS: 268 #endif 269 #ifdef PT_SETFPREGS 270 case PT_SETFPREGS: 271 #endif 272 #ifdef PT_GETDBREGS 273 case PT_GETDBREGS: 274 #endif 275 #ifdef PT_SETDBREGS 276 case PT_SETDBREGS: 277 #endif 278 /* not being traced... */ 279 PROC_LOCK(p); 280 if ((p->p_flag & P_TRACED) == 0) { 281 PROC_UNLOCK(p); 282 return EPERM; 283 } 284 285 /* not being traced by YOU */ 286 if (p->p_pptr != curp) { 287 PROC_UNLOCK(p); 288 return EBUSY; 289 } 290 291 /* not currently stopped */ 292 mtx_lock_spin(&sched_lock); 293 if (p->p_stat != SSTOP || (p->p_flag & P_WAITED) == 0) { 294 mtx_unlock_spin(&sched_lock); 295 PROC_UNLOCK(p); 296 return EBUSY; 297 } 298 mtx_unlock_spin(&sched_lock); 299 PROC_UNLOCK(p); 300 301 /* OK */ 302 break; 303 304 default: 305 return EINVAL; 306 } 307 308 #ifdef FIX_SSTEP 309 /* 310 * Single step fixup ala procfs 311 */ 312 FIX_SSTEP(p); 313 #endif 314 315 /* 316 * Actually do the requests 317 */ 318 319 curp->p_retval[0] = 0; 320 321 switch (uap->req) { 322 case PT_TRACE_ME: 323 /* set my trace flag and "owner" so it can read/write me */ 324 sx_xlock(&proctree_lock); 325 PROC_LOCK(p); 326 p->p_flag |= P_TRACED; 327 p->p_oppid = p->p_pptr->p_pid; 328 PROC_UNLOCK(p); 329 sx_xunlock(&proctree_lock); 330 return 0; 331 332 case PT_ATTACH: 333 /* security check done above */ 334 sx_xlock(&proctree_lock); 335 PROC_LOCK(p); 336 p->p_flag |= P_TRACED; 337 p->p_oppid = p->p_pptr->p_pid; 338 if (p->p_pptr != curp) 339 proc_reparent(p, curp); 340 PROC_UNLOCK(p); 341 sx_xunlock(&proctree_lock); 342 uap->data = SIGSTOP; 343 goto sendsig; /* in PT_CONTINUE below */ 344 345 case PT_STEP: 346 case PT_CONTINUE: 347 case PT_DETACH: 348 if ((uap->req != PT_STEP) && ((unsigned)uap->data >= NSIG)) 349 return EINVAL; 350 351 PHOLD(p); 352 353 if (uap->req == PT_STEP) { 354 if ((error = ptrace_single_step (p))) { 355 PRELE(p); 356 return error; 357 } 358 } 359 360 if (uap->addr != (caddr_t)1) { 361 fill_kinfo_proc (p, &p->p_addr->u_kproc); 362 if ((error = ptrace_set_pc (p, 363 (u_long)(uintfptr_t)uap->addr))) { 364 PRELE(p); 365 return error; 366 } 367 } 368 PRELE(p); 369 370 if (uap->req == PT_DETACH) { 371 /* reset process parent */ 372 sx_xlock(&proctree_lock); 373 if (p->p_oppid != p->p_pptr->p_pid) { 374 struct proc *pp; 375 376 pp = pfind(p->p_oppid); 377 PROC_LOCK(p); 378 proc_reparent(p, pp ? pp : initproc); 379 } else 380 PROC_LOCK(p); 381 p->p_flag &= ~(P_TRACED | P_WAITED); 382 p->p_oppid = 0; 383 384 PROC_UNLOCK(p); 385 sx_xunlock(&proctree_lock); 386 387 /* should we send SIGCHLD? */ 388 389 } 390 391 sendsig: 392 /* deliver or queue signal */ 393 PROC_LOCK(p); 394 mtx_lock_spin(&sched_lock); 395 if (p->p_stat == SSTOP) { 396 p->p_xstat = uap->data; 397 setrunnable(p); 398 mtx_unlock_spin(&sched_lock); 399 } else { 400 mtx_unlock_spin(&sched_lock); 401 if (uap->data) 402 psignal(p, uap->data); 403 404 } 405 PROC_UNLOCK(p); 406 return 0; 407 408 case PT_WRITE_I: 409 case PT_WRITE_D: 410 write = 1; 411 /* fallthrough */ 412 case PT_READ_I: 413 case PT_READ_D: 414 /* write = 0 set above */ 415 iov.iov_base = write ? (caddr_t)&uap->data : (caddr_t)curp->p_retval; 416 iov.iov_len = sizeof(int); 417 uio.uio_iov = &iov; 418 uio.uio_iovcnt = 1; 419 uio.uio_offset = (off_t)(uintptr_t)uap->addr; 420 uio.uio_resid = sizeof(int); 421 uio.uio_segflg = UIO_SYSSPACE; /* ie: the uap */ 422 uio.uio_rw = write ? UIO_WRITE : UIO_READ; 423 uio.uio_procp = p; 424 error = procfs_domem(curp, p, NULL, &uio); 425 if (uio.uio_resid != 0) { 426 /* 427 * XXX procfs_domem() doesn't currently return ENOSPC, 428 * so I think write() can bogusly return 0. 429 * XXX what happens for short writes? We don't want 430 * to write partial data. 431 * XXX procfs_domem() returns EPERM for other invalid 432 * addresses. Convert this to EINVAL. Does this 433 * clobber returns of EPERM for other reasons? 434 */ 435 if (error == 0 || error == ENOSPC || error == EPERM) 436 error = EINVAL; /* EOF */ 437 } 438 return (error); 439 440 case PT_READ_U: 441 if ((uintptr_t)uap->addr > UPAGES * PAGE_SIZE - sizeof(int)) { 442 return EFAULT; 443 } 444 if ((uintptr_t)uap->addr & (sizeof(int) - 1)) { 445 return EFAULT; 446 } 447 if (ptrace_read_u_check(p,(vm_offset_t) uap->addr, 448 sizeof(int))) { 449 return EFAULT; 450 } 451 error = 0; 452 PHOLD(p); /* user had damn well better be incore! */ 453 mtx_lock_spin(&sched_lock); 454 if (p->p_sflag & PS_INMEM) { 455 mtx_unlock_spin(&sched_lock); 456 fill_kinfo_proc (p, &p->p_addr->u_kproc); 457 curp->p_retval[0] = *(int *) 458 ((uintptr_t)p->p_addr + (uintptr_t)uap->addr); 459 } else { 460 mtx_unlock_spin(&sched_lock); 461 curp->p_retval[0] = 0; 462 error = EFAULT; 463 } 464 PRELE(p); 465 return error; 466 467 case PT_WRITE_U: 468 PHOLD(p); /* user had damn well better be incore! */ 469 mtx_lock_spin(&sched_lock); 470 if (p->p_sflag & PS_INMEM) { 471 mtx_unlock_spin(&sched_lock); 472 fill_kinfo_proc (p, &p->p_addr->u_kproc); 473 error = ptrace_write_u(p, (vm_offset_t)uap->addr, uap->data); 474 } else { 475 mtx_unlock_spin(&sched_lock); 476 error = EFAULT; 477 } 478 PRELE(p); 479 return error; 480 481 case PT_KILL: 482 uap->data = SIGKILL; 483 goto sendsig; /* in PT_CONTINUE above */ 484 485 #ifdef PT_SETREGS 486 case PT_SETREGS: 487 write = 1; 488 /* fallthrough */ 489 #endif /* PT_SETREGS */ 490 #ifdef PT_GETREGS 491 case PT_GETREGS: 492 /* write = 0 above */ 493 #endif /* PT_SETREGS */ 494 #if defined(PT_SETREGS) || defined(PT_GETREGS) 495 if (!procfs_validregs(p)) /* no P_SYSTEM procs please */ 496 return EINVAL; 497 else { 498 iov.iov_base = uap->addr; 499 iov.iov_len = sizeof(struct reg); 500 uio.uio_iov = &iov; 501 uio.uio_iovcnt = 1; 502 uio.uio_offset = 0; 503 uio.uio_resid = sizeof(struct reg); 504 uio.uio_segflg = UIO_USERSPACE; 505 uio.uio_rw = write ? UIO_WRITE : UIO_READ; 506 uio.uio_procp = curp; 507 return (procfs_doregs(curp, p, NULL, &uio)); 508 } 509 #endif /* defined(PT_SETREGS) || defined(PT_GETREGS) */ 510 511 #ifdef PT_SETFPREGS 512 case PT_SETFPREGS: 513 write = 1; 514 /* fallthrough */ 515 #endif /* PT_SETFPREGS */ 516 #ifdef PT_GETFPREGS 517 case PT_GETFPREGS: 518 /* write = 0 above */ 519 #endif /* PT_SETFPREGS */ 520 #if defined(PT_SETFPREGS) || defined(PT_GETFPREGS) 521 if (!procfs_validfpregs(p)) /* no P_SYSTEM procs please */ 522 return EINVAL; 523 else { 524 iov.iov_base = uap->addr; 525 iov.iov_len = sizeof(struct fpreg); 526 uio.uio_iov = &iov; 527 uio.uio_iovcnt = 1; 528 uio.uio_offset = 0; 529 uio.uio_resid = sizeof(struct fpreg); 530 uio.uio_segflg = UIO_USERSPACE; 531 uio.uio_rw = write ? UIO_WRITE : UIO_READ; 532 uio.uio_procp = curp; 533 return (procfs_dofpregs(curp, p, NULL, &uio)); 534 } 535 #endif /* defined(PT_SETFPREGS) || defined(PT_GETFPREGS) */ 536 537 #ifdef PT_SETDBREGS 538 case PT_SETDBREGS: 539 write = 1; 540 /* fallthrough */ 541 #endif /* PT_SETDBREGS */ 542 #ifdef PT_GETDBREGS 543 case PT_GETDBREGS: 544 /* write = 0 above */ 545 #endif /* PT_SETDBREGS */ 546 #if defined(PT_SETDBREGS) || defined(PT_GETDBREGS) 547 if (!procfs_validdbregs(p)) /* no P_SYSTEM procs please */ 548 return EINVAL; 549 else { 550 iov.iov_base = uap->addr; 551 iov.iov_len = sizeof(struct dbreg); 552 uio.uio_iov = &iov; 553 uio.uio_iovcnt = 1; 554 uio.uio_offset = 0; 555 uio.uio_resid = sizeof(struct dbreg); 556 uio.uio_segflg = UIO_USERSPACE; 557 uio.uio_rw = write ? UIO_WRITE : UIO_READ; 558 uio.uio_procp = curp; 559 return (procfs_dodbregs(curp, p, NULL, &uio)); 560 } 561 #endif /* defined(PT_SETDBREGS) || defined(PT_GETDBREGS) */ 562 563 default: 564 break; 565 } 566 567 return 0; 568 } 569 570 int 571 trace_req(p) 572 struct proc *p; 573 { 574 return 1; 575 } 576 577 /* 578 * stopevent() 579 * Stop a process because of a procfs event; 580 * stay stopped until p->p_step is cleared 581 * (cleared by PIOCCONT in procfs). 582 * 583 * Must be called with the proc struct mutex held. 584 */ 585 586 void 587 stopevent(p, event, val) 588 struct proc *p; 589 unsigned int event; 590 unsigned int val; 591 { 592 593 PROC_LOCK_ASSERT(p, MA_OWNED | MA_NOTRECURSED); 594 p->p_step = 1; 595 596 do { 597 p->p_xstat = val; 598 p->p_stype = event; /* Which event caused the stop? */ 599 wakeup(&p->p_stype); /* Wake up any PIOCWAIT'ing procs */ 600 msleep(&p->p_step, &p->p_mtx, PWAIT, "stopevent", 0); 601 } while (p->p_step); 602 } 603