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(td, uap) 206 struct thread *td; 207 struct ptrace_args *uap; 208 { 209 struct proc *curp = td->td_proc; 210 struct proc *p; 211 struct iovec iov; 212 struct uio uio; 213 int error = 0; 214 int write; 215 216 write = 0; 217 if (uap->req == PT_TRACE_ME) { 218 p = curp; 219 PROC_LOCK(p); 220 } else { 221 if ((p = pfind(uap->pid)) == NULL) 222 return ESRCH; 223 } 224 if (p_cansee(curp, p)) { 225 PROC_UNLOCK(p); 226 return (ESRCH); 227 } 228 229 /* 230 * Permissions check 231 */ 232 switch (uap->req) { 233 case PT_TRACE_ME: 234 /* Always legal. */ 235 break; 236 237 case PT_ATTACH: 238 /* Self */ 239 if (p->p_pid == curp->p_pid) { 240 PROC_UNLOCK(p); 241 return EINVAL; 242 } 243 244 /* Already traced */ 245 if (p->p_flag & P_TRACED) { 246 PROC_UNLOCK(p); 247 return EBUSY; 248 } 249 250 if ((error = p_candebug(curp, p))) { 251 PROC_UNLOCK(p); 252 return error; 253 } 254 255 /* OK */ 256 break; 257 258 case PT_READ_I: 259 case PT_READ_D: 260 case PT_WRITE_I: 261 case PT_WRITE_D: 262 case PT_CONTINUE: 263 case PT_KILL: 264 case PT_STEP: 265 case PT_DETACH: 266 #ifdef PT_GETREGS 267 case PT_GETREGS: 268 #endif 269 #ifdef PT_SETREGS 270 case PT_SETREGS: 271 #endif 272 #ifdef PT_GETFPREGS 273 case PT_GETFPREGS: 274 #endif 275 #ifdef PT_SETFPREGS 276 case PT_SETFPREGS: 277 #endif 278 #ifdef PT_GETDBREGS 279 case PT_GETDBREGS: 280 #endif 281 #ifdef PT_SETDBREGS 282 case PT_SETDBREGS: 283 #endif 284 /* not being traced... */ 285 if ((p->p_flag & P_TRACED) == 0) { 286 PROC_UNLOCK(p); 287 return EPERM; 288 } 289 290 /* not being traced by YOU */ 291 if (p->p_pptr != curp) { 292 PROC_UNLOCK(p); 293 return EBUSY; 294 } 295 296 /* not currently stopped */ 297 mtx_lock_spin(&sched_lock); 298 if (p->p_stat != SSTOP || (p->p_flag & P_WAITED) == 0) { 299 mtx_unlock_spin(&sched_lock); 300 PROC_UNLOCK(p); 301 return EBUSY; 302 } 303 mtx_unlock_spin(&sched_lock); 304 305 /* OK */ 306 break; 307 308 default: 309 PROC_UNLOCK(p); 310 return EINVAL; 311 } 312 313 PROC_UNLOCK(p); 314 #ifdef FIX_SSTEP 315 /* 316 * Single step fixup ala procfs 317 */ 318 FIX_SSTEP(&p->p_thread); /* XXXKSE */ 319 #endif 320 321 /* 322 * Actually do the requests 323 */ 324 325 td->td_retval[0] = 0; 326 327 switch (uap->req) { 328 case PT_TRACE_ME: 329 /* set my trace flag and "owner" so it can read/write me */ 330 sx_xlock(&proctree_lock); 331 PROC_LOCK(p); 332 p->p_flag |= P_TRACED; 333 p->p_oppid = p->p_pptr->p_pid; 334 PROC_UNLOCK(p); 335 sx_xunlock(&proctree_lock); 336 return 0; 337 338 case PT_ATTACH: 339 /* security check done above */ 340 sx_xlock(&proctree_lock); 341 PROC_LOCK(p); 342 p->p_flag |= P_TRACED; 343 p->p_oppid = p->p_pptr->p_pid; 344 if (p->p_pptr != curp) 345 proc_reparent(p, curp); 346 PROC_UNLOCK(p); 347 sx_xunlock(&proctree_lock); 348 uap->data = SIGSTOP; 349 goto sendsig; /* in PT_CONTINUE below */ 350 351 case PT_STEP: 352 case PT_CONTINUE: 353 case PT_DETACH: 354 if ((uap->req != PT_STEP) && ((unsigned)uap->data >= NSIG)) 355 return EINVAL; 356 357 PHOLD(p); 358 359 if (uap->req == PT_STEP) { 360 if ((error = ptrace_single_step (td))) { 361 PRELE(p); 362 return error; 363 } 364 } 365 366 if (uap->addr != (caddr_t)1) { 367 fill_kinfo_proc (p, &p->p_uarea->u_kproc); 368 if ((error = ptrace_set_pc (td, 369 (u_long)(uintfptr_t)uap->addr))) { 370 PRELE(p); 371 return error; 372 } 373 } 374 PRELE(p); 375 376 if (uap->req == PT_DETACH) { 377 /* reset process parent */ 378 sx_xlock(&proctree_lock); 379 if (p->p_oppid != p->p_pptr->p_pid) { 380 struct proc *pp; 381 382 pp = pfind(p->p_oppid); 383 if (pp != NULL) 384 PROC_UNLOCK(pp); 385 else 386 pp = initproc; 387 PROC_LOCK(p); 388 proc_reparent(p, pp); 389 } else 390 PROC_LOCK(p); 391 p->p_flag &= ~(P_TRACED | P_WAITED); 392 p->p_oppid = 0; 393 394 PROC_UNLOCK(p); 395 sx_xunlock(&proctree_lock); 396 397 /* should we send SIGCHLD? */ 398 399 } 400 401 sendsig: 402 /* deliver or queue signal */ 403 PROC_LOCK(p); 404 mtx_lock_spin(&sched_lock); 405 if (p->p_stat == SSTOP) { 406 p->p_xstat = uap->data; 407 setrunnable(&p->p_thread); /* XXXKSE */ 408 mtx_unlock_spin(&sched_lock); 409 } else { 410 mtx_unlock_spin(&sched_lock); 411 if (uap->data) 412 psignal(p, uap->data); 413 414 } 415 PROC_UNLOCK(p); 416 return 0; 417 418 case PT_WRITE_I: 419 case PT_WRITE_D: 420 write = 1; 421 /* fallthrough */ 422 case PT_READ_I: 423 case PT_READ_D: 424 /* write = 0 set above */ 425 iov.iov_base = write ? (caddr_t)&uap->data : (caddr_t)td->td_retval; 426 iov.iov_len = sizeof(int); 427 uio.uio_iov = &iov; 428 uio.uio_iovcnt = 1; 429 uio.uio_offset = (off_t)(uintptr_t)uap->addr; 430 uio.uio_resid = sizeof(int); 431 uio.uio_segflg = UIO_SYSSPACE; /* ie: the uap */ 432 uio.uio_rw = write ? UIO_WRITE : UIO_READ; 433 uio.uio_td = td; 434 error = procfs_domem(curp, p, NULL, &uio); 435 if (uio.uio_resid != 0) { 436 /* 437 * XXX procfs_domem() doesn't currently return ENOSPC, 438 * so I think write() can bogusly return 0. 439 * XXX what happens for short writes? We don't want 440 * to write partial data. 441 * XXX procfs_domem() returns EPERM for other invalid 442 * addresses. Convert this to EINVAL. Does this 443 * clobber returns of EPERM for other reasons? 444 */ 445 if (error == 0 || error == ENOSPC || error == EPERM) 446 error = EINVAL; /* EOF */ 447 } 448 return (error); 449 450 case PT_KILL: 451 uap->data = SIGKILL; 452 goto sendsig; /* in PT_CONTINUE above */ 453 454 #ifdef PT_SETREGS 455 case PT_SETREGS: 456 write = 1; 457 /* fallthrough */ 458 #endif /* PT_SETREGS */ 459 #ifdef PT_GETREGS 460 case PT_GETREGS: 461 /* write = 0 above */ 462 #endif /* PT_SETREGS */ 463 #if defined(PT_SETREGS) || defined(PT_GETREGS) 464 if (!procfs_validregs(td)) /* no P_SYSTEM procs please */ 465 return EINVAL; 466 else { 467 iov.iov_base = uap->addr; 468 iov.iov_len = sizeof(struct reg); 469 uio.uio_iov = &iov; 470 uio.uio_iovcnt = 1; 471 uio.uio_offset = 0; 472 uio.uio_resid = sizeof(struct reg); 473 uio.uio_segflg = UIO_USERSPACE; 474 uio.uio_rw = write ? UIO_WRITE : UIO_READ; 475 uio.uio_td = td; 476 return (procfs_doregs(curp, p, NULL, &uio)); 477 } 478 #endif /* defined(PT_SETREGS) || defined(PT_GETREGS) */ 479 480 #ifdef PT_SETFPREGS 481 case PT_SETFPREGS: 482 write = 1; 483 /* fallthrough */ 484 #endif /* PT_SETFPREGS */ 485 #ifdef PT_GETFPREGS 486 case PT_GETFPREGS: 487 /* write = 0 above */ 488 #endif /* PT_SETFPREGS */ 489 #if defined(PT_SETFPREGS) || defined(PT_GETFPREGS) 490 if (!procfs_validfpregs(td)) /* no P_SYSTEM procs please */ 491 return EINVAL; 492 else { 493 iov.iov_base = uap->addr; 494 iov.iov_len = sizeof(struct fpreg); 495 uio.uio_iov = &iov; 496 uio.uio_iovcnt = 1; 497 uio.uio_offset = 0; 498 uio.uio_resid = sizeof(struct fpreg); 499 uio.uio_segflg = UIO_USERSPACE; 500 uio.uio_rw = write ? UIO_WRITE : UIO_READ; 501 uio.uio_td = td; 502 return (procfs_dofpregs(curp, p, NULL, &uio)); 503 } 504 #endif /* defined(PT_SETFPREGS) || defined(PT_GETFPREGS) */ 505 506 #ifdef PT_SETDBREGS 507 case PT_SETDBREGS: 508 write = 1; 509 /* fallthrough */ 510 #endif /* PT_SETDBREGS */ 511 #ifdef PT_GETDBREGS 512 case PT_GETDBREGS: 513 /* write = 0 above */ 514 #endif /* PT_SETDBREGS */ 515 #if defined(PT_SETDBREGS) || defined(PT_GETDBREGS) 516 if (!procfs_validdbregs(td)) /* no P_SYSTEM procs please */ 517 return EINVAL; 518 else { 519 iov.iov_base = uap->addr; 520 iov.iov_len = sizeof(struct dbreg); 521 uio.uio_iov = &iov; 522 uio.uio_iovcnt = 1; 523 uio.uio_offset = 0; 524 uio.uio_resid = sizeof(struct dbreg); 525 uio.uio_segflg = UIO_USERSPACE; 526 uio.uio_rw = write ? UIO_WRITE : UIO_READ; 527 uio.uio_td = td; 528 return (procfs_dodbregs(curp, p, NULL, &uio)); 529 } 530 #endif /* defined(PT_SETDBREGS) || defined(PT_GETDBREGS) */ 531 532 default: 533 break; 534 } 535 536 return 0; 537 } 538 539 int 540 trace_req(p) 541 struct proc *p; 542 { 543 return 1; 544 } 545 546 /* 547 * stopevent() 548 * Stop a process because of a procfs event; 549 * stay stopped until p->p_step is cleared 550 * (cleared by PIOCCONT in procfs). 551 * 552 * Must be called with the proc struct mutex held. 553 */ 554 555 void 556 stopevent(p, event, val) 557 struct proc *p; 558 unsigned int event; 559 unsigned int val; 560 { 561 562 PROC_LOCK_ASSERT(p, MA_OWNED | MA_NOTRECURSED); 563 p->p_step = 1; 564 565 do { 566 p->p_xstat = val; 567 p->p_stype = event; /* Which event caused the stop? */ 568 wakeup(&p->p_stype); /* Wake up any PIOCWAIT'ing procs */ 569 msleep(&p->p_step, &p->p_mtx, PWAIT, "stopevent", 0); 570 } while (p->p_step); 571 } 572