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 1.29 1997/04/27 21:26:29 alex 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, single_use; 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, &single_use); 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, single_use; 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, &single_use); 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, retval) 205 struct proc *curp; 206 struct ptrace_args *uap; 207 int *retval; 208 { 209 struct proc *p; 210 struct iovec iov; 211 struct uio uio; 212 int error = 0; 213 int write; 214 int s; 215 216 if (uap->req == PT_TRACE_ME) 217 p = curp; 218 else { 219 if ((p = pfind(uap->pid)) == NULL) 220 return ESRCH; 221 } 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 /* not owned by you, has done setuid (unless you're root) */ 241 if ((p->p_cred->p_ruid != curp->p_cred->p_ruid) || 242 (p->p_flag & P_SUGID)) { 243 if (error = suser(curp->p_ucred, &curp->p_acflag)) 244 return error; 245 } 246 247 /* can't trace init when securelevel > 0 */ 248 if (securelevel > 0 && p->p_pid == 1) 249 return EPERM; 250 251 /* OK */ 252 break; 253 254 case PT_READ_I: 255 case PT_READ_D: 256 case PT_READ_U: 257 case PT_WRITE_I: 258 case PT_WRITE_D: 259 case PT_WRITE_U: 260 case PT_CONTINUE: 261 case PT_KILL: 262 case PT_STEP: 263 case PT_DETACH: 264 #ifdef PT_GETREGS 265 case PT_GETREGS: 266 #endif 267 #ifdef PT_SETREGS 268 case PT_SETREGS: 269 #endif 270 #ifdef PT_GETFPREGS 271 case PT_GETFPREGS: 272 #endif 273 #ifdef PT_SETFPREGS 274 case PT_SETFPREGS: 275 #endif 276 /* not being traced... */ 277 if ((p->p_flag & P_TRACED) == 0) 278 return EPERM; 279 280 /* not being traced by YOU */ 281 if (p->p_pptr != curp) 282 return EBUSY; 283 284 /* not currently stopped */ 285 if (p->p_stat != SSTOP || (p->p_flag & P_WAITED) == 0) 286 return EBUSY; 287 288 /* OK */ 289 break; 290 291 default: 292 return EINVAL; 293 } 294 295 #ifdef FIX_SSTEP 296 /* 297 * Single step fixup ala procfs 298 */ 299 FIX_SSTEP(p); 300 #endif 301 302 /* 303 * Actually do the requests 304 */ 305 306 write = 0; 307 *retval = 0; 308 309 switch (uap->req) { 310 case PT_TRACE_ME: 311 /* set my trace flag and "owner" so it can read/write me */ 312 p->p_flag |= P_TRACED; 313 p->p_oppid = p->p_pptr->p_pid; 314 return 0; 315 316 case PT_ATTACH: 317 /* security check done above */ 318 p->p_flag |= P_TRACED; 319 p->p_oppid = p->p_pptr->p_pid; 320 if (p->p_pptr != curp) 321 proc_reparent(p, curp); 322 uap->data = SIGSTOP; 323 goto sendsig; /* in PT_CONTINUE below */ 324 325 case PT_STEP: 326 case PT_CONTINUE: 327 case PT_DETACH: 328 if ((unsigned)uap->data >= NSIG) 329 return EINVAL; 330 331 PHOLD(p); 332 333 if (uap->req == PT_STEP) { 334 if ((error = ptrace_single_step (p))) { 335 PRELE(p); 336 return error; 337 } 338 } 339 340 if (uap->addr != (caddr_t)1) { 341 fill_eproc (p, &p->p_addr->u_kproc.kp_eproc); 342 if ((error = ptrace_set_pc (p, (u_int)uap->addr))) { 343 PRELE(p); 344 return error; 345 } 346 } 347 PRELE(p); 348 349 if (uap->req == PT_DETACH) { 350 /* reset process parent */ 351 if (p->p_oppid != p->p_pptr->p_pid) { 352 struct proc *pp; 353 354 pp = pfind(p->p_oppid); 355 proc_reparent(p, pp ? pp : initproc); 356 } 357 358 p->p_flag &= ~(P_TRACED | P_WAITED); 359 p->p_oppid = 0; 360 361 /* should we send SIGCHLD? */ 362 363 } 364 365 sendsig: 366 /* deliver or queue signal */ 367 s = splhigh(); 368 if (p->p_stat == SSTOP) { 369 p->p_xstat = uap->data; 370 setrunnable(p); 371 } else if (uap->data) { 372 psignal(p, uap->data); 373 } 374 splx(s); 375 return 0; 376 377 case PT_WRITE_I: 378 case PT_WRITE_D: 379 write = 1; 380 /* fallthrough */ 381 case PT_READ_I: 382 case PT_READ_D: 383 /* write = 0 set above */ 384 iov.iov_base = write ? (caddr_t)&uap->data : (caddr_t)retval; 385 iov.iov_len = sizeof(int); 386 uio.uio_iov = &iov; 387 uio.uio_iovcnt = 1; 388 uio.uio_offset = (off_t)(u_long)uap->addr; 389 uio.uio_resid = sizeof(int); 390 uio.uio_segflg = UIO_SYSSPACE; /* ie: the uap */ 391 uio.uio_rw = write ? UIO_WRITE : UIO_READ; 392 uio.uio_procp = p; 393 error = procfs_domem(curp, p, NULL, &uio); 394 if (uio.uio_resid != 0) { 395 /* 396 * XXX procfs_domem() doesn't currently return ENOSPC, 397 * so I think write() can bogusly return 0. 398 * XXX what happens for short writes? We don't want 399 * to write partial data. 400 * XXX procfs_domem() returns EPERM for other invalid 401 * addresses. Convert this to EINVAL. Does this 402 * clobber returns of EPERM for other reasons? 403 */ 404 if (error == 0 || error == ENOSPC || error == EPERM) 405 error = EINVAL; /* EOF */ 406 } 407 return (error); 408 409 case PT_READ_U: 410 if ((u_int)uap->addr > (UPAGES * PAGE_SIZE - sizeof(int))) { 411 return EFAULT; 412 } 413 error = 0; 414 PHOLD(p); /* user had damn well better be incore! */ 415 if (p->p_flag & P_INMEM) { 416 p->p_addr->u_kproc.kp_proc = *p; 417 fill_eproc (p, &p->p_addr->u_kproc.kp_eproc); 418 *retval = *(int*)((u_int)p->p_addr + (u_int)uap->addr); 419 } else { 420 *retval = 0; 421 error = EFAULT; 422 } 423 PRELE(p); 424 return error; 425 426 case PT_WRITE_U: 427 PHOLD(p); /* user had damn well better be incore! */ 428 if (p->p_flag & P_INMEM) { 429 p->p_addr->u_kproc.kp_proc = *p; 430 fill_eproc (p, &p->p_addr->u_kproc.kp_eproc); 431 error = ptrace_write_u(p, (vm_offset_t)uap->addr, uap->data); 432 } else { 433 error = EFAULT; 434 } 435 PRELE(p); 436 return error; 437 438 case PT_KILL: 439 uap->data = SIGKILL; 440 goto sendsig; /* in PT_CONTINUE above */ 441 442 #ifdef PT_SETREGS 443 case PT_SETREGS: 444 write = 1; 445 /* fallthrough */ 446 #endif /* PT_SETREGS */ 447 #ifdef PT_GETREGS 448 case PT_GETREGS: 449 /* write = 0 above */ 450 #endif /* PT_SETREGS */ 451 #if defined(PT_SETREGS) || defined(PT_GETREGS) 452 if (!procfs_validregs(p)) /* no P_SYSTEM procs please */ 453 return EINVAL; 454 else { 455 iov.iov_base = uap->addr; 456 iov.iov_len = sizeof(struct reg); 457 uio.uio_iov = &iov; 458 uio.uio_iovcnt = 1; 459 uio.uio_offset = 0; 460 uio.uio_resid = sizeof(struct reg); 461 uio.uio_segflg = UIO_USERSPACE; 462 uio.uio_rw = write ? UIO_WRITE : UIO_READ; 463 uio.uio_procp = curp; 464 return (procfs_doregs(curp, p, NULL, &uio)); 465 } 466 #endif /* defined(PT_SETREGS) || defined(PT_GETREGS) */ 467 468 #ifdef PT_SETFPREGS 469 case PT_SETFPREGS: 470 write = 1; 471 /* fallthrough */ 472 #endif /* PT_SETFPREGS */ 473 #ifdef PT_GETFPREGS 474 case PT_GETFPREGS: 475 /* write = 0 above */ 476 #endif /* PT_SETFPREGS */ 477 #if defined(PT_SETFPREGS) || defined(PT_GETFPREGS) 478 if (!procfs_validfpregs(p)) /* no P_SYSTEM procs please */ 479 return EINVAL; 480 else { 481 iov.iov_base = uap->addr; 482 iov.iov_len = sizeof(struct fpreg); 483 uio.uio_iov = &iov; 484 uio.uio_iovcnt = 1; 485 uio.uio_offset = 0; 486 uio.uio_resid = sizeof(struct fpreg); 487 uio.uio_segflg = UIO_USERSPACE; 488 uio.uio_rw = write ? UIO_WRITE : UIO_READ; 489 uio.uio_procp = curp; 490 return (procfs_dofpregs(curp, p, NULL, &uio)); 491 } 492 #endif /* defined(PT_SETFPREGS) || defined(PT_GETFPREGS) */ 493 494 default: 495 break; 496 } 497 498 return 0; 499 } 500 501 int 502 trace_req(p) 503 struct proc *p; 504 { 505 return 1; 506 } 507