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