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