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