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 * $Id: sys_process.c,v 1.44 1999/04/27 11:16:13 phk Exp $ 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 if (uap->req == PT_TRACE_ME) 216 p = curp; 217 else { 218 if ((p = pfind(uap->pid)) == NULL) 219 return ESRCH; 220 } 221 if (!PRISON_CHECK(curp, p)) 222 return (ESRCH); 223 224 /* 225 * Permissions check 226 */ 227 switch (uap->req) { 228 case PT_TRACE_ME: 229 /* Always legal. */ 230 break; 231 232 case PT_ATTACH: 233 /* Self */ 234 if (p->p_pid == curp->p_pid) 235 return EINVAL; 236 237 /* Already traced */ 238 if (p->p_flag & P_TRACED) 239 return EBUSY; 240 241 /* not owned by you, has done setuid (unless you're root) */ 242 if ((p->p_cred->p_ruid != curp->p_cred->p_ruid) || 243 (p->p_flag & P_SUGID)) { 244 if ((error = suser(curp)) != 0) 245 return error; 246 } 247 248 /* can't trace init when securelevel > 0 */ 249 if (securelevel > 0 && p->p_pid == 1) 250 return EPERM; 251 252 /* OK */ 253 break; 254 255 case PT_READ_I: 256 case PT_READ_D: 257 case PT_READ_U: 258 case PT_WRITE_I: 259 case PT_WRITE_D: 260 case PT_WRITE_U: 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 /* not being traced... */ 278 if ((p->p_flag & P_TRACED) == 0) 279 return EPERM; 280 281 /* not being traced by YOU */ 282 if (p->p_pptr != curp) 283 return EBUSY; 284 285 /* not currently stopped */ 286 if (p->p_stat != SSTOP || (p->p_flag & P_WAITED) == 0) 287 return EBUSY; 288 289 /* OK */ 290 break; 291 292 default: 293 return EINVAL; 294 } 295 296 #ifdef FIX_SSTEP 297 /* 298 * Single step fixup ala procfs 299 */ 300 FIX_SSTEP(p); 301 #endif 302 303 /* 304 * Actually do the requests 305 */ 306 307 write = 0; 308 curp->p_retval[0] = 0; 309 310 switch (uap->req) { 311 case PT_TRACE_ME: 312 /* set my trace flag and "owner" so it can read/write me */ 313 p->p_flag |= P_TRACED; 314 p->p_oppid = p->p_pptr->p_pid; 315 return 0; 316 317 case PT_ATTACH: 318 /* security check done above */ 319 p->p_flag |= P_TRACED; 320 p->p_oppid = p->p_pptr->p_pid; 321 if (p->p_pptr != curp) 322 proc_reparent(p, curp); 323 uap->data = SIGSTOP; 324 goto sendsig; /* in PT_CONTINUE below */ 325 326 case PT_STEP: 327 case PT_CONTINUE: 328 case PT_DETACH: 329 if ((unsigned)uap->data >= NSIG) 330 return EINVAL; 331 332 PHOLD(p); 333 334 if (uap->req == PT_STEP) { 335 if ((error = ptrace_single_step (p))) { 336 PRELE(p); 337 return error; 338 } 339 } 340 341 if (uap->addr != (caddr_t)1) { 342 fill_eproc (p, &p->p_addr->u_kproc.kp_eproc); 343 if ((error = ptrace_set_pc (p, 344 (u_long)(uintfptr_t)uap->addr))) { 345 PRELE(p); 346 return error; 347 } 348 } 349 PRELE(p); 350 351 if (uap->req == PT_DETACH) { 352 /* reset process parent */ 353 if (p->p_oppid != p->p_pptr->p_pid) { 354 struct proc *pp; 355 356 pp = pfind(p->p_oppid); 357 proc_reparent(p, pp ? pp : initproc); 358 } 359 360 p->p_flag &= ~(P_TRACED | P_WAITED); 361 p->p_oppid = 0; 362 363 /* should we send SIGCHLD? */ 364 365 } 366 367 sendsig: 368 /* deliver or queue signal */ 369 s = splhigh(); 370 if (p->p_stat == SSTOP) { 371 p->p_xstat = uap->data; 372 setrunnable(p); 373 } else if (uap->data) { 374 psignal(p, uap->data); 375 } 376 splx(s); 377 return 0; 378 379 case PT_WRITE_I: 380 case PT_WRITE_D: 381 write = 1; 382 /* fallthrough */ 383 case PT_READ_I: 384 case PT_READ_D: 385 /* write = 0 set above */ 386 iov.iov_base = write ? (caddr_t)&uap->data : (caddr_t)curp->p_retval; 387 iov.iov_len = sizeof(int); 388 uio.uio_iov = &iov; 389 uio.uio_iovcnt = 1; 390 uio.uio_offset = (off_t)(uintptr_t)uap->addr; 391 uio.uio_resid = sizeof(int); 392 uio.uio_segflg = UIO_SYSSPACE; /* ie: the uap */ 393 uio.uio_rw = write ? UIO_WRITE : UIO_READ; 394 uio.uio_procp = p; 395 error = procfs_domem(curp, p, NULL, &uio); 396 if (uio.uio_resid != 0) { 397 /* 398 * XXX procfs_domem() doesn't currently return ENOSPC, 399 * so I think write() can bogusly return 0. 400 * XXX what happens for short writes? We don't want 401 * to write partial data. 402 * XXX procfs_domem() returns EPERM for other invalid 403 * addresses. Convert this to EINVAL. Does this 404 * clobber returns of EPERM for other reasons? 405 */ 406 if (error == 0 || error == ENOSPC || error == EPERM) 407 error = EINVAL; /* EOF */ 408 } 409 return (error); 410 411 case PT_READ_U: 412 if ((uintptr_t)uap->addr > UPAGES * PAGE_SIZE - sizeof(int)) { 413 return EFAULT; 414 } 415 if ((uintptr_t)uap->addr & (sizeof(int) - 1)) { 416 return EFAULT; 417 } 418 if (ptrace_read_u_check(p,(vm_offset_t) uap->addr, 419 sizeof(int)) && 420 !procfs_kmemaccess(curp)) { 421 return EFAULT; 422 } 423 error = 0; 424 PHOLD(p); /* user had damn well better be incore! */ 425 if (p->p_flag & P_INMEM) { 426 p->p_addr->u_kproc.kp_proc = *p; 427 fill_eproc (p, &p->p_addr->u_kproc.kp_eproc); 428 curp->p_retval[0] = *(int *) 429 ((uintptr_t)p->p_addr + (uintptr_t)uap->addr); 430 } else { 431 curp->p_retval[0] = 0; 432 error = EFAULT; 433 } 434 PRELE(p); 435 return error; 436 437 case PT_WRITE_U: 438 PHOLD(p); /* user had damn well better be incore! */ 439 if (p->p_flag & P_INMEM) { 440 p->p_addr->u_kproc.kp_proc = *p; 441 fill_eproc (p, &p->p_addr->u_kproc.kp_eproc); 442 error = ptrace_write_u(p, (vm_offset_t)uap->addr, uap->data); 443 } else { 444 error = EFAULT; 445 } 446 PRELE(p); 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 default: 506 break; 507 } 508 509 return 0; 510 } 511 512 int 513 trace_req(p) 514 struct proc *p; 515 { 516 return 1; 517 } 518 519 /* 520 * stopevent() 521 * Stop a process because of a procfs event; 522 * stay stopped until p->p_step is cleared 523 * (cleared by PIOCCONT in procfs). 524 */ 525 526 void 527 stopevent(struct proc *p, unsigned int event, unsigned int val) { 528 p->p_step = 1; 529 530 do { 531 p->p_xstat = val; 532 p->p_stype = event; /* Which event caused the stop? */ 533 wakeup(&p->p_stype); /* Wake up any PIOCWAIT'ing procs */ 534 tsleep(&p->p_step, PWAIT, "stopevent", 0); 535 } while (p->p_step); 536 } 537