sys_process.c revision 304017
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 32#include <sys/cdefs.h> 33__FBSDID("$FreeBSD: stable/10/sys/kern/sys_process.c 304017 2016-08-12 19:43:06Z jhb $"); 34 35#include "opt_compat.h" 36 37#include <sys/param.h> 38#include <sys/systm.h> 39#include <sys/lock.h> 40#include <sys/mutex.h> 41#include <sys/syscallsubr.h> 42#include <sys/sysent.h> 43#include <sys/sysproto.h> 44#include <sys/priv.h> 45#include <sys/proc.h> 46#include <sys/vnode.h> 47#include <sys/ptrace.h> 48#include <sys/rwlock.h> 49#include <sys/sx.h> 50#include <sys/malloc.h> 51#include <sys/signalvar.h> 52 53#include <machine/reg.h> 54 55#include <security/audit/audit.h> 56 57#include <vm/vm.h> 58#include <vm/pmap.h> 59#include <vm/vm_extern.h> 60#include <vm/vm_map.h> 61#include <vm/vm_kern.h> 62#include <vm/vm_object.h> 63#include <vm/vm_page.h> 64#include <vm/vm_param.h> 65 66#ifdef COMPAT_FREEBSD32 67#include <sys/procfs.h> 68#include <compat/freebsd32/freebsd32_signal.h> 69 70struct ptrace_io_desc32 { 71 int piod_op; 72 uint32_t piod_offs; 73 uint32_t piod_addr; 74 uint32_t piod_len; 75}; 76 77struct ptrace_vm_entry32 { 78 int pve_entry; 79 int pve_timestamp; 80 uint32_t pve_start; 81 uint32_t pve_end; 82 uint32_t pve_offset; 83 u_int pve_prot; 84 u_int pve_pathlen; 85 int32_t pve_fileid; 86 u_int pve_fsid; 87 uint32_t pve_path; 88}; 89 90struct ptrace_lwpinfo32 { 91 lwpid_t pl_lwpid; /* LWP described. */ 92 int pl_event; /* Event that stopped the LWP. */ 93 int pl_flags; /* LWP flags. */ 94 sigset_t pl_sigmask; /* LWP signal mask */ 95 sigset_t pl_siglist; /* LWP pending signal */ 96 struct siginfo32 pl_siginfo; /* siginfo for signal */ 97 char pl_tdname[MAXCOMLEN + 1]; /* LWP name. */ 98 pid_t pl_child_pid; /* New child pid */ 99 u_int pl_syscall_code; 100 u_int pl_syscall_narg; 101}; 102 103#endif 104 105/* 106 * Functions implemented using PROC_ACTION(): 107 * 108 * proc_read_regs(proc, regs) 109 * Get the current user-visible register set from the process 110 * and copy it into the regs structure (<machine/reg.h>). 111 * The process is stopped at the time read_regs is called. 112 * 113 * proc_write_regs(proc, regs) 114 * Update the current register set from the passed in regs 115 * structure. Take care to avoid clobbering special CPU 116 * registers or privileged bits in the PSL. 117 * Depending on the architecture this may have fix-up work to do, 118 * especially if the IAR or PCW are modified. 119 * The process is stopped at the time write_regs is called. 120 * 121 * proc_read_fpregs, proc_write_fpregs 122 * deal with the floating point register set, otherwise as above. 123 * 124 * proc_read_dbregs, proc_write_dbregs 125 * deal with the processor debug register set, otherwise as above. 126 * 127 * proc_sstep(proc) 128 * Arrange for the process to trap after executing a single instruction. 129 */ 130 131#define PROC_ACTION(action) do { \ 132 int error; \ 133 \ 134 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); \ 135 if ((td->td_proc->p_flag & P_INMEM) == 0) \ 136 error = EIO; \ 137 else \ 138 error = (action); \ 139 return (error); \ 140} while(0) 141 142int 143proc_read_regs(struct thread *td, struct reg *regs) 144{ 145 146 PROC_ACTION(fill_regs(td, regs)); 147} 148 149int 150proc_write_regs(struct thread *td, struct reg *regs) 151{ 152 153 PROC_ACTION(set_regs(td, regs)); 154} 155 156int 157proc_read_dbregs(struct thread *td, struct dbreg *dbregs) 158{ 159 160 PROC_ACTION(fill_dbregs(td, dbregs)); 161} 162 163int 164proc_write_dbregs(struct thread *td, struct dbreg *dbregs) 165{ 166 167 PROC_ACTION(set_dbregs(td, dbregs)); 168} 169 170/* 171 * Ptrace doesn't support fpregs at all, and there are no security holes 172 * or translations for fpregs, so we can just copy them. 173 */ 174int 175proc_read_fpregs(struct thread *td, struct fpreg *fpregs) 176{ 177 178 PROC_ACTION(fill_fpregs(td, fpregs)); 179} 180 181int 182proc_write_fpregs(struct thread *td, struct fpreg *fpregs) 183{ 184 185 PROC_ACTION(set_fpregs(td, fpregs)); 186} 187 188#ifdef COMPAT_FREEBSD32 189/* For 32 bit binaries, we need to expose the 32 bit regs layouts. */ 190int 191proc_read_regs32(struct thread *td, struct reg32 *regs32) 192{ 193 194 PROC_ACTION(fill_regs32(td, regs32)); 195} 196 197int 198proc_write_regs32(struct thread *td, struct reg32 *regs32) 199{ 200 201 PROC_ACTION(set_regs32(td, regs32)); 202} 203 204int 205proc_read_dbregs32(struct thread *td, struct dbreg32 *dbregs32) 206{ 207 208 PROC_ACTION(fill_dbregs32(td, dbregs32)); 209} 210 211int 212proc_write_dbregs32(struct thread *td, struct dbreg32 *dbregs32) 213{ 214 215 PROC_ACTION(set_dbregs32(td, dbregs32)); 216} 217 218int 219proc_read_fpregs32(struct thread *td, struct fpreg32 *fpregs32) 220{ 221 222 PROC_ACTION(fill_fpregs32(td, fpregs32)); 223} 224 225int 226proc_write_fpregs32(struct thread *td, struct fpreg32 *fpregs32) 227{ 228 229 PROC_ACTION(set_fpregs32(td, fpregs32)); 230} 231#endif 232 233int 234proc_sstep(struct thread *td) 235{ 236 237 PROC_ACTION(ptrace_single_step(td)); 238} 239 240int 241proc_rwmem(struct proc *p, struct uio *uio) 242{ 243 vm_map_t map; 244 vm_offset_t pageno; /* page number */ 245 vm_prot_t reqprot; 246 int error, fault_flags, page_offset, writing; 247 248 /* 249 * Assert that someone has locked this vmspace. (Should be 250 * curthread but we can't assert that.) This keeps the process 251 * from exiting out from under us until this operation completes. 252 */ 253 KASSERT(p->p_lock >= 1, ("%s: process %p (pid %d) not held", __func__, 254 p, p->p_pid)); 255 256 /* 257 * The map we want... 258 */ 259 map = &p->p_vmspace->vm_map; 260 261 /* 262 * If we are writing, then we request vm_fault() to create a private 263 * copy of each page. Since these copies will not be writeable by the 264 * process, we must explicity request that they be dirtied. 265 */ 266 writing = uio->uio_rw == UIO_WRITE; 267 reqprot = writing ? VM_PROT_COPY | VM_PROT_READ : VM_PROT_READ; 268 fault_flags = writing ? VM_FAULT_DIRTY : VM_FAULT_NORMAL; 269 270 /* 271 * Only map in one page at a time. We don't have to, but it 272 * makes things easier. This way is trivial - right? 273 */ 274 do { 275 vm_offset_t uva; 276 u_int len; 277 vm_page_t m; 278 279 uva = (vm_offset_t)uio->uio_offset; 280 281 /* 282 * Get the page number of this segment. 283 */ 284 pageno = trunc_page(uva); 285 page_offset = uva - pageno; 286 287 /* 288 * How many bytes to copy 289 */ 290 len = min(PAGE_SIZE - page_offset, uio->uio_resid); 291 292 /* 293 * Fault and hold the page on behalf of the process. 294 */ 295 error = vm_fault_hold(map, pageno, reqprot, fault_flags, &m); 296 if (error != KERN_SUCCESS) { 297 if (error == KERN_RESOURCE_SHORTAGE) 298 error = ENOMEM; 299 else 300 error = EFAULT; 301 break; 302 } 303 304 /* 305 * Now do the i/o move. 306 */ 307 error = uiomove_fromphys(&m, page_offset, len, uio); 308 309 /* Make the I-cache coherent for breakpoints. */ 310 if (writing && error == 0) { 311 vm_map_lock_read(map); 312 if (vm_map_check_protection(map, pageno, pageno + 313 PAGE_SIZE, VM_PROT_EXECUTE)) 314 vm_sync_icache(map, uva, len); 315 vm_map_unlock_read(map); 316 } 317 318 /* 319 * Release the page. 320 */ 321 vm_page_lock(m); 322 vm_page_unhold(m); 323 vm_page_unlock(m); 324 325 } while (error == 0 && uio->uio_resid > 0); 326 327 return (error); 328} 329 330static int 331ptrace_vm_entry(struct thread *td, struct proc *p, struct ptrace_vm_entry *pve) 332{ 333 struct vattr vattr; 334 vm_map_t map; 335 vm_map_entry_t entry; 336 vm_object_t obj, tobj, lobj; 337 struct vmspace *vm; 338 struct vnode *vp; 339 char *freepath, *fullpath; 340 u_int pathlen; 341 int error, index; 342 343 error = 0; 344 obj = NULL; 345 346 vm = vmspace_acquire_ref(p); 347 map = &vm->vm_map; 348 vm_map_lock_read(map); 349 350 do { 351 entry = map->header.next; 352 index = 0; 353 while (index < pve->pve_entry && entry != &map->header) { 354 entry = entry->next; 355 index++; 356 } 357 if (index != pve->pve_entry) { 358 error = EINVAL; 359 break; 360 } 361 while (entry != &map->header && 362 (entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0) { 363 entry = entry->next; 364 index++; 365 } 366 if (entry == &map->header) { 367 error = ENOENT; 368 break; 369 } 370 371 /* We got an entry. */ 372 pve->pve_entry = index + 1; 373 pve->pve_timestamp = map->timestamp; 374 pve->pve_start = entry->start; 375 pve->pve_end = entry->end - 1; 376 pve->pve_offset = entry->offset; 377 pve->pve_prot = entry->protection; 378 379 /* Backing object's path needed? */ 380 if (pve->pve_pathlen == 0) 381 break; 382 383 pathlen = pve->pve_pathlen; 384 pve->pve_pathlen = 0; 385 386 obj = entry->object.vm_object; 387 if (obj != NULL) 388 VM_OBJECT_RLOCK(obj); 389 } while (0); 390 391 vm_map_unlock_read(map); 392 393 pve->pve_fsid = VNOVAL; 394 pve->pve_fileid = VNOVAL; 395 396 if (error == 0 && obj != NULL) { 397 lobj = obj; 398 for (tobj = obj; tobj != NULL; tobj = tobj->backing_object) { 399 if (tobj != obj) 400 VM_OBJECT_RLOCK(tobj); 401 if (lobj != obj) 402 VM_OBJECT_RUNLOCK(lobj); 403 lobj = tobj; 404 pve->pve_offset += tobj->backing_object_offset; 405 } 406 vp = vm_object_vnode(lobj); 407 if (vp != NULL) 408 vref(vp); 409 if (lobj != obj) 410 VM_OBJECT_RUNLOCK(lobj); 411 VM_OBJECT_RUNLOCK(obj); 412 413 if (vp != NULL) { 414 freepath = NULL; 415 fullpath = NULL; 416 vn_fullpath(td, vp, &fullpath, &freepath); 417 vn_lock(vp, LK_SHARED | LK_RETRY); 418 if (VOP_GETATTR(vp, &vattr, td->td_ucred) == 0) { 419 pve->pve_fileid = vattr.va_fileid; 420 pve->pve_fsid = vattr.va_fsid; 421 } 422 vput(vp); 423 424 if (fullpath != NULL) { 425 pve->pve_pathlen = strlen(fullpath) + 1; 426 if (pve->pve_pathlen <= pathlen) { 427 error = copyout(fullpath, pve->pve_path, 428 pve->pve_pathlen); 429 } else 430 error = ENAMETOOLONG; 431 } 432 if (freepath != NULL) 433 free(freepath, M_TEMP); 434 } 435 } 436 vmspace_free(vm); 437 if (error == 0) 438 CTR3(KTR_PTRACE, "PT_VM_ENTRY: pid %d, entry %d, start %p", 439 p->p_pid, pve->pve_entry, pve->pve_start); 440 441 return (error); 442} 443 444#ifdef COMPAT_FREEBSD32 445static int 446ptrace_vm_entry32(struct thread *td, struct proc *p, 447 struct ptrace_vm_entry32 *pve32) 448{ 449 struct ptrace_vm_entry pve; 450 int error; 451 452 pve.pve_entry = pve32->pve_entry; 453 pve.pve_pathlen = pve32->pve_pathlen; 454 pve.pve_path = (void *)(uintptr_t)pve32->pve_path; 455 456 error = ptrace_vm_entry(td, p, &pve); 457 if (error == 0) { 458 pve32->pve_entry = pve.pve_entry; 459 pve32->pve_timestamp = pve.pve_timestamp; 460 pve32->pve_start = pve.pve_start; 461 pve32->pve_end = pve.pve_end; 462 pve32->pve_offset = pve.pve_offset; 463 pve32->pve_prot = pve.pve_prot; 464 pve32->pve_fileid = pve.pve_fileid; 465 pve32->pve_fsid = pve.pve_fsid; 466 } 467 468 pve32->pve_pathlen = pve.pve_pathlen; 469 return (error); 470} 471 472static void 473ptrace_lwpinfo_to32(const struct ptrace_lwpinfo *pl, 474 struct ptrace_lwpinfo32 *pl32) 475{ 476 477 pl32->pl_lwpid = pl->pl_lwpid; 478 pl32->pl_event = pl->pl_event; 479 pl32->pl_flags = pl->pl_flags; 480 pl32->pl_sigmask = pl->pl_sigmask; 481 pl32->pl_siglist = pl->pl_siglist; 482 siginfo_to_siginfo32(&pl->pl_siginfo, &pl32->pl_siginfo); 483 strcpy(pl32->pl_tdname, pl->pl_tdname); 484 pl32->pl_child_pid = pl->pl_child_pid; 485 pl32->pl_syscall_code = pl->pl_syscall_code; 486 pl32->pl_syscall_narg = pl->pl_syscall_narg; 487} 488#endif /* COMPAT_FREEBSD32 */ 489 490/* 491 * Process debugging system call. 492 */ 493#ifndef _SYS_SYSPROTO_H_ 494struct ptrace_args { 495 int req; 496 pid_t pid; 497 caddr_t addr; 498 int data; 499}; 500#endif 501 502#ifdef COMPAT_FREEBSD32 503/* 504 * This CPP subterfuge is to try and reduce the number of ifdefs in 505 * the body of the code. 506 * COPYIN(uap->addr, &r.reg, sizeof r.reg); 507 * becomes either: 508 * copyin(uap->addr, &r.reg, sizeof r.reg); 509 * or 510 * copyin(uap->addr, &r.reg32, sizeof r.reg32); 511 * .. except this is done at runtime. 512 */ 513#define COPYIN(u, k, s) wrap32 ? \ 514 copyin(u, k ## 32, s ## 32) : \ 515 copyin(u, k, s) 516#define COPYOUT(k, u, s) wrap32 ? \ 517 copyout(k ## 32, u, s ## 32) : \ 518 copyout(k, u, s) 519#else 520#define COPYIN(u, k, s) copyin(u, k, s) 521#define COPYOUT(k, u, s) copyout(k, u, s) 522#endif 523int 524sys_ptrace(struct thread *td, struct ptrace_args *uap) 525{ 526 /* 527 * XXX this obfuscation is to reduce stack usage, but the register 528 * structs may be too large to put on the stack anyway. 529 */ 530 union { 531 struct ptrace_io_desc piod; 532 struct ptrace_lwpinfo pl; 533 struct ptrace_vm_entry pve; 534 struct dbreg dbreg; 535 struct fpreg fpreg; 536 struct reg reg; 537#ifdef COMPAT_FREEBSD32 538 struct dbreg32 dbreg32; 539 struct fpreg32 fpreg32; 540 struct reg32 reg32; 541 struct ptrace_io_desc32 piod32; 542 struct ptrace_lwpinfo32 pl32; 543 struct ptrace_vm_entry32 pve32; 544#endif 545 } r; 546 void *addr; 547 int error = 0; 548#ifdef COMPAT_FREEBSD32 549 int wrap32 = 0; 550 551 if (SV_CURPROC_FLAG(SV_ILP32)) 552 wrap32 = 1; 553#endif 554 AUDIT_ARG_PID(uap->pid); 555 AUDIT_ARG_CMD(uap->req); 556 AUDIT_ARG_VALUE(uap->data); 557 addr = &r; 558 switch (uap->req) { 559 case PT_GETREGS: 560 case PT_GETFPREGS: 561 case PT_GETDBREGS: 562 case PT_LWPINFO: 563 break; 564 case PT_SETREGS: 565 error = COPYIN(uap->addr, &r.reg, sizeof r.reg); 566 break; 567 case PT_SETFPREGS: 568 error = COPYIN(uap->addr, &r.fpreg, sizeof r.fpreg); 569 break; 570 case PT_SETDBREGS: 571 error = COPYIN(uap->addr, &r.dbreg, sizeof r.dbreg); 572 break; 573 case PT_IO: 574 error = COPYIN(uap->addr, &r.piod, sizeof r.piod); 575 break; 576 case PT_VM_ENTRY: 577 error = COPYIN(uap->addr, &r.pve, sizeof r.pve); 578 break; 579 default: 580 addr = uap->addr; 581 break; 582 } 583 if (error) 584 return (error); 585 586 error = kern_ptrace(td, uap->req, uap->pid, addr, uap->data); 587 if (error) 588 return (error); 589 590 switch (uap->req) { 591 case PT_VM_ENTRY: 592 error = COPYOUT(&r.pve, uap->addr, sizeof r.pve); 593 break; 594 case PT_IO: 595 error = COPYOUT(&r.piod, uap->addr, sizeof r.piod); 596 break; 597 case PT_GETREGS: 598 error = COPYOUT(&r.reg, uap->addr, sizeof r.reg); 599 break; 600 case PT_GETFPREGS: 601 error = COPYOUT(&r.fpreg, uap->addr, sizeof r.fpreg); 602 break; 603 case PT_GETDBREGS: 604 error = COPYOUT(&r.dbreg, uap->addr, sizeof r.dbreg); 605 break; 606 case PT_LWPINFO: 607 error = copyout(&r.pl, uap->addr, uap->data); 608 break; 609 } 610 611 return (error); 612} 613#undef COPYIN 614#undef COPYOUT 615 616#ifdef COMPAT_FREEBSD32 617/* 618 * PROC_READ(regs, td2, addr); 619 * becomes either: 620 * proc_read_regs(td2, addr); 621 * or 622 * proc_read_regs32(td2, addr); 623 * .. except this is done at runtime. There is an additional 624 * complication in that PROC_WRITE disallows 32 bit consumers 625 * from writing to 64 bit address space targets. 626 */ 627#define PROC_READ(w, t, a) wrap32 ? \ 628 proc_read_ ## w ## 32(t, a) : \ 629 proc_read_ ## w (t, a) 630#define PROC_WRITE(w, t, a) wrap32 ? \ 631 (safe ? proc_write_ ## w ## 32(t, a) : EINVAL ) : \ 632 proc_write_ ## w (t, a) 633#else 634#define PROC_READ(w, t, a) proc_read_ ## w (t, a) 635#define PROC_WRITE(w, t, a) proc_write_ ## w (t, a) 636#endif 637 638int 639kern_ptrace(struct thread *td, int req, pid_t pid, void *addr, int data) 640{ 641 struct iovec iov; 642 struct uio uio; 643 struct proc *curp, *p, *pp; 644 struct thread *td2 = NULL, *td3; 645 struct ptrace_io_desc *piod = NULL; 646 struct ptrace_lwpinfo *pl; 647 int error, write, tmp, num; 648 int proctree_locked = 0; 649 lwpid_t tid = 0, *buf; 650#ifdef COMPAT_FREEBSD32 651 int wrap32 = 0, safe = 0; 652 struct ptrace_io_desc32 *piod32 = NULL; 653 struct ptrace_lwpinfo32 *pl32 = NULL; 654 struct ptrace_lwpinfo plr; 655#endif 656 657 curp = td->td_proc; 658 659 /* Lock proctree before locking the process. */ 660 switch (req) { 661 case PT_TRACE_ME: 662 case PT_ATTACH: 663 case PT_STEP: 664 case PT_CONTINUE: 665 case PT_TO_SCE: 666 case PT_TO_SCX: 667 case PT_SYSCALL: 668 case PT_FOLLOW_FORK: 669 case PT_LWP_EVENTS: 670 case PT_DETACH: 671 sx_xlock(&proctree_lock); 672 proctree_locked = 1; 673 break; 674 default: 675 break; 676 } 677 678 write = 0; 679 if (req == PT_TRACE_ME) { 680 p = td->td_proc; 681 PROC_LOCK(p); 682 } else { 683 if (pid <= PID_MAX) { 684 if ((p = pfind(pid)) == NULL) { 685 if (proctree_locked) 686 sx_xunlock(&proctree_lock); 687 return (ESRCH); 688 } 689 } else { 690 td2 = tdfind(pid, -1); 691 if (td2 == NULL) { 692 if (proctree_locked) 693 sx_xunlock(&proctree_lock); 694 return (ESRCH); 695 } 696 p = td2->td_proc; 697 tid = pid; 698 pid = p->p_pid; 699 } 700 } 701 AUDIT_ARG_PROCESS(p); 702 703 if ((p->p_flag & P_WEXIT) != 0) { 704 error = ESRCH; 705 goto fail; 706 } 707 if ((error = p_cansee(td, p)) != 0) 708 goto fail; 709 710 if ((error = p_candebug(td, p)) != 0) 711 goto fail; 712 713 /* 714 * System processes can't be debugged. 715 */ 716 if ((p->p_flag & P_SYSTEM) != 0) { 717 error = EINVAL; 718 goto fail; 719 } 720 721 if (tid == 0) { 722 if ((p->p_flag & P_STOPPED_TRACE) != 0) { 723 KASSERT(p->p_xthread != NULL, ("NULL p_xthread")); 724 td2 = p->p_xthread; 725 } else { 726 td2 = FIRST_THREAD_IN_PROC(p); 727 } 728 tid = td2->td_tid; 729 } 730 731#ifdef COMPAT_FREEBSD32 732 /* 733 * Test if we're a 32 bit client and what the target is. 734 * Set the wrap controls accordingly. 735 */ 736 if (SV_CURPROC_FLAG(SV_ILP32)) { 737 if (SV_PROC_FLAG(td2->td_proc, SV_ILP32)) 738 safe = 1; 739 wrap32 = 1; 740 } 741#endif 742 /* 743 * Permissions check 744 */ 745 switch (req) { 746 case PT_TRACE_ME: 747 /* 748 * Always legal, when there is a parent process which 749 * could trace us. Otherwise, reject. 750 */ 751 if ((p->p_flag & P_TRACED) != 0) { 752 error = EBUSY; 753 goto fail; 754 } 755 if (p->p_pptr == initproc) { 756 error = EPERM; 757 goto fail; 758 } 759 break; 760 761 case PT_ATTACH: 762 /* Self */ 763 if (p == td->td_proc) { 764 error = EINVAL; 765 goto fail; 766 } 767 768 /* Already traced */ 769 if (p->p_flag & P_TRACED) { 770 error = EBUSY; 771 goto fail; 772 } 773 774 /* Can't trace an ancestor if you're being traced. */ 775 if (curp->p_flag & P_TRACED) { 776 for (pp = curp->p_pptr; pp != NULL; pp = pp->p_pptr) { 777 if (pp == p) { 778 error = EINVAL; 779 goto fail; 780 } 781 } 782 } 783 784 785 /* OK */ 786 break; 787 788 case PT_CLEARSTEP: 789 /* Allow thread to clear single step for itself */ 790 if (td->td_tid == tid) 791 break; 792 793 /* FALLTHROUGH */ 794 default: 795 /* not being traced... */ 796 if ((p->p_flag & P_TRACED) == 0) { 797 error = EPERM; 798 goto fail; 799 } 800 801 /* not being traced by YOU */ 802 if (p->p_pptr != td->td_proc) { 803 error = EBUSY; 804 goto fail; 805 } 806 807 /* not currently stopped */ 808 if ((p->p_flag & (P_STOPPED_SIG | P_STOPPED_TRACE)) == 0 || 809 p->p_suspcount != p->p_numthreads || 810 (p->p_flag & P_WAITED) == 0) { 811 error = EBUSY; 812 goto fail; 813 } 814 815 if ((p->p_flag & P_STOPPED_TRACE) == 0) { 816 static int count = 0; 817 if (count++ == 0) 818 printf("P_STOPPED_TRACE not set.\n"); 819 } 820 821 /* OK */ 822 break; 823 } 824 825 /* Keep this process around until we finish this request. */ 826 _PHOLD(p); 827 828#ifdef FIX_SSTEP 829 /* 830 * Single step fixup ala procfs 831 */ 832 FIX_SSTEP(td2); 833#endif 834 835 /* 836 * Actually do the requests 837 */ 838 839 td->td_retval[0] = 0; 840 841 switch (req) { 842 case PT_TRACE_ME: 843 /* set my trace flag and "owner" so it can read/write me */ 844 p->p_flag |= P_TRACED; 845 if (p->p_flag & P_PPWAIT) 846 p->p_flag |= P_PPTRACE; 847 p->p_oppid = p->p_pptr->p_pid; 848 CTR1(KTR_PTRACE, "PT_TRACE_ME: pid %d", p->p_pid); 849 break; 850 851 case PT_ATTACH: 852 /* security check done above */ 853 /* 854 * It would be nice if the tracing relationship was separate 855 * from the parent relationship but that would require 856 * another set of links in the proc struct or for "wait" 857 * to scan the entire proc table. To make life easier, 858 * we just re-parent the process we're trying to trace. 859 * The old parent is remembered so we can put things back 860 * on a "detach". 861 */ 862 p->p_flag |= P_TRACED; 863 p->p_oppid = p->p_pptr->p_pid; 864 if (p->p_pptr != td->td_proc) { 865 proc_reparent(p, td->td_proc); 866 } 867 data = SIGSTOP; 868 CTR2(KTR_PTRACE, "PT_ATTACH: pid %d, oppid %d", p->p_pid, 869 p->p_oppid); 870 goto sendsig; /* in PT_CONTINUE below */ 871 872 case PT_CLEARSTEP: 873 CTR2(KTR_PTRACE, "PT_CLEARSTEP: tid %d (pid %d)", td2->td_tid, 874 p->p_pid); 875 error = ptrace_clear_single_step(td2); 876 break; 877 878 case PT_SETSTEP: 879 CTR2(KTR_PTRACE, "PT_SETSTEP: tid %d (pid %d)", td2->td_tid, 880 p->p_pid); 881 error = ptrace_single_step(td2); 882 break; 883 884 case PT_SUSPEND: 885 CTR2(KTR_PTRACE, "PT_SUSPEND: tid %d (pid %d)", td2->td_tid, 886 p->p_pid); 887 td2->td_dbgflags |= TDB_SUSPEND; 888 thread_lock(td2); 889 td2->td_flags |= TDF_NEEDSUSPCHK; 890 thread_unlock(td2); 891 break; 892 893 case PT_RESUME: 894 CTR2(KTR_PTRACE, "PT_RESUME: tid %d (pid %d)", td2->td_tid, 895 p->p_pid); 896 td2->td_dbgflags &= ~TDB_SUSPEND; 897 break; 898 899 case PT_FOLLOW_FORK: 900 CTR3(KTR_PTRACE, "PT_FOLLOW_FORK: pid %d %s -> %s", p->p_pid, 901 p->p_flag & P_FOLLOWFORK ? "enabled" : "disabled", 902 data ? "enabled" : "disabled"); 903 if (data) 904 p->p_flag |= P_FOLLOWFORK; 905 else 906 p->p_flag &= ~P_FOLLOWFORK; 907 break; 908 909 case PT_LWP_EVENTS: 910 CTR3(KTR_PTRACE, "PT_LWP_EVENTS: pid %d %s -> %s", p->p_pid, 911 p->p_flag2 & P2_LWP_EVENTS ? "enabled" : "disabled", 912 data ? "enabled" : "disabled"); 913 if (data) 914 p->p_flag2 |= P2_LWP_EVENTS; 915 else 916 p->p_flag2 &= ~P2_LWP_EVENTS; 917 break; 918 919 case PT_STEP: 920 case PT_CONTINUE: 921 case PT_TO_SCE: 922 case PT_TO_SCX: 923 case PT_SYSCALL: 924 case PT_DETACH: 925 /* Zero means do not send any signal */ 926 if (data < 0 || data > _SIG_MAXSIG) { 927 error = EINVAL; 928 break; 929 } 930 931 switch (req) { 932 case PT_STEP: 933 CTR2(KTR_PTRACE, "PT_STEP: tid %d (pid %d)", 934 td2->td_tid, p->p_pid); 935 error = ptrace_single_step(td2); 936 if (error) 937 goto out; 938 break; 939 case PT_CONTINUE: 940 case PT_TO_SCE: 941 case PT_TO_SCX: 942 case PT_SYSCALL: 943 if (addr != (void *)1) { 944 error = ptrace_set_pc(td2, 945 (u_long)(uintfptr_t)addr); 946 if (error) 947 goto out; 948 } 949 switch (req) { 950 case PT_TO_SCE: 951 p->p_stops |= S_PT_SCE; 952 CTR4(KTR_PTRACE, 953 "PT_TO_SCE: pid %d, stops = %#x, PC = %#lx, sig = %d", 954 p->p_pid, p->p_stops, 955 (u_long)(uintfptr_t)addr, data); 956 break; 957 case PT_TO_SCX: 958 p->p_stops |= S_PT_SCX; 959 CTR4(KTR_PTRACE, 960 "PT_TO_SCX: pid %d, stops = %#x, PC = %#lx, sig = %d", 961 p->p_pid, p->p_stops, 962 (u_long)(uintfptr_t)addr, data); 963 break; 964 case PT_SYSCALL: 965 p->p_stops |= S_PT_SCE | S_PT_SCX; 966 CTR4(KTR_PTRACE, 967 "PT_SYSCALL: pid %d, stops = %#x, PC = %#lx, sig = %d", 968 p->p_pid, p->p_stops, 969 (u_long)(uintfptr_t)addr, data); 970 break; 971 case PT_CONTINUE: 972 CTR3(KTR_PTRACE, 973 "PT_CONTINUE: pid %d, PC = %#lx, sig = %d", 974 p->p_pid, (u_long)(uintfptr_t)addr, data); 975 break; 976 } 977 break; 978 case PT_DETACH: 979 /* 980 * Reset the process parent. 981 * 982 * NB: This clears P_TRACED before reparenting 983 * a detached process back to its original 984 * parent. Otherwise the debugee will be set 985 * as an orphan of the debugger. 986 */ 987 p->p_flag &= ~(P_TRACED | P_WAITED | P_FOLLOWFORK); 988 if (p->p_oppid != p->p_pptr->p_pid) { 989 PROC_LOCK(p->p_pptr); 990 sigqueue_take(p->p_ksi); 991 PROC_UNLOCK(p->p_pptr); 992 993 pp = proc_realparent(p); 994 proc_reparent(p, pp); 995 if (pp == initproc) 996 p->p_sigparent = SIGCHLD; 997 CTR3(KTR_PTRACE, 998 "PT_DETACH: pid %d reparented to pid %d, sig %d", 999 p->p_pid, pp->p_pid, data); 1000 } else 1001 CTR2(KTR_PTRACE, "PT_DETACH: pid %d, sig %d", 1002 p->p_pid, data); 1003 p->p_oppid = 0; 1004 p->p_stops = 0; 1005 1006 /* should we send SIGCHLD? */ 1007 /* childproc_continued(p); */ 1008 break; 1009 } 1010 1011 sendsig: 1012 if (proctree_locked) { 1013 sx_xunlock(&proctree_lock); 1014 proctree_locked = 0; 1015 } 1016 p->p_xstat = data; 1017 p->p_xthread = NULL; 1018 if ((p->p_flag & (P_STOPPED_SIG | P_STOPPED_TRACE)) != 0) { 1019 /* deliver or queue signal */ 1020 td2->td_dbgflags &= ~TDB_XSIG; 1021 td2->td_xsig = data; 1022 1023 if (req == PT_DETACH) { 1024 FOREACH_THREAD_IN_PROC(p, td3) 1025 td3->td_dbgflags &= ~TDB_SUSPEND; 1026 } 1027 /* 1028 * unsuspend all threads, to not let a thread run, 1029 * you should use PT_SUSPEND to suspend it before 1030 * continuing process. 1031 */ 1032 PROC_SLOCK(p); 1033 p->p_flag &= ~(P_STOPPED_TRACE|P_STOPPED_SIG|P_WAITED); 1034 thread_unsuspend(p); 1035 PROC_SUNLOCK(p); 1036 if (req == PT_ATTACH) 1037 kern_psignal(p, data); 1038 } else { 1039 if (data) 1040 kern_psignal(p, data); 1041 } 1042 break; 1043 1044 case PT_WRITE_I: 1045 case PT_WRITE_D: 1046 td2->td_dbgflags |= TDB_USERWR; 1047 write = 1; 1048 /* FALLTHROUGH */ 1049 case PT_READ_I: 1050 case PT_READ_D: 1051 PROC_UNLOCK(p); 1052 tmp = 0; 1053 /* write = 0 set above */ 1054 iov.iov_base = write ? (caddr_t)&data : (caddr_t)&tmp; 1055 iov.iov_len = sizeof(int); 1056 uio.uio_iov = &iov; 1057 uio.uio_iovcnt = 1; 1058 uio.uio_offset = (off_t)(uintptr_t)addr; 1059 uio.uio_resid = sizeof(int); 1060 uio.uio_segflg = UIO_SYSSPACE; /* i.e.: the uap */ 1061 uio.uio_rw = write ? UIO_WRITE : UIO_READ; 1062 uio.uio_td = td; 1063 error = proc_rwmem(p, &uio); 1064 if (uio.uio_resid != 0) { 1065 /* 1066 * XXX proc_rwmem() doesn't currently return ENOSPC, 1067 * so I think write() can bogusly return 0. 1068 * XXX what happens for short writes? We don't want 1069 * to write partial data. 1070 * XXX proc_rwmem() returns EPERM for other invalid 1071 * addresses. Convert this to EINVAL. Does this 1072 * clobber returns of EPERM for other reasons? 1073 */ 1074 if (error == 0 || error == ENOSPC || error == EPERM) 1075 error = EINVAL; /* EOF */ 1076 } 1077 if (!write) 1078 td->td_retval[0] = tmp; 1079 if (error == 0) { 1080 if (write) 1081 CTR3(KTR_PTRACE, "PT_WRITE: pid %d: %p <= %#x", 1082 p->p_pid, addr, data); 1083 else 1084 CTR3(KTR_PTRACE, "PT_READ: pid %d: %p >= %#x", 1085 p->p_pid, addr, tmp); 1086 } 1087 PROC_LOCK(p); 1088 break; 1089 1090 case PT_IO: 1091#ifdef COMPAT_FREEBSD32 1092 if (wrap32) { 1093 piod32 = addr; 1094 iov.iov_base = (void *)(uintptr_t)piod32->piod_addr; 1095 iov.iov_len = piod32->piod_len; 1096 uio.uio_offset = (off_t)(uintptr_t)piod32->piod_offs; 1097 uio.uio_resid = piod32->piod_len; 1098 } else 1099#endif 1100 { 1101 piod = addr; 1102 iov.iov_base = piod->piod_addr; 1103 iov.iov_len = piod->piod_len; 1104 uio.uio_offset = (off_t)(uintptr_t)piod->piod_offs; 1105 uio.uio_resid = piod->piod_len; 1106 } 1107 uio.uio_iov = &iov; 1108 uio.uio_iovcnt = 1; 1109 uio.uio_segflg = UIO_USERSPACE; 1110 uio.uio_td = td; 1111#ifdef COMPAT_FREEBSD32 1112 tmp = wrap32 ? piod32->piod_op : piod->piod_op; 1113#else 1114 tmp = piod->piod_op; 1115#endif 1116 switch (tmp) { 1117 case PIOD_READ_D: 1118 case PIOD_READ_I: 1119 CTR3(KTR_PTRACE, "PT_IO: pid %d: READ (%p, %#x)", 1120 p->p_pid, (uintptr_t)uio.uio_offset, uio.uio_resid); 1121 uio.uio_rw = UIO_READ; 1122 break; 1123 case PIOD_WRITE_D: 1124 case PIOD_WRITE_I: 1125 CTR3(KTR_PTRACE, "PT_IO: pid %d: WRITE (%p, %#x)", 1126 p->p_pid, (uintptr_t)uio.uio_offset, uio.uio_resid); 1127 td2->td_dbgflags |= TDB_USERWR; 1128 uio.uio_rw = UIO_WRITE; 1129 break; 1130 default: 1131 error = EINVAL; 1132 goto out; 1133 } 1134 PROC_UNLOCK(p); 1135 error = proc_rwmem(p, &uio); 1136#ifdef COMPAT_FREEBSD32 1137 if (wrap32) 1138 piod32->piod_len -= uio.uio_resid; 1139 else 1140#endif 1141 piod->piod_len -= uio.uio_resid; 1142 PROC_LOCK(p); 1143 break; 1144 1145 case PT_KILL: 1146 CTR1(KTR_PTRACE, "PT_KILL: pid %d", p->p_pid); 1147 data = SIGKILL; 1148 goto sendsig; /* in PT_CONTINUE above */ 1149 1150 case PT_SETREGS: 1151 CTR2(KTR_PTRACE, "PT_SETREGS: tid %d (pid %d)", td2->td_tid, 1152 p->p_pid); 1153 td2->td_dbgflags |= TDB_USERWR; 1154 error = PROC_WRITE(regs, td2, addr); 1155 break; 1156 1157 case PT_GETREGS: 1158 CTR2(KTR_PTRACE, "PT_GETREGS: tid %d (pid %d)", td2->td_tid, 1159 p->p_pid); 1160 error = PROC_READ(regs, td2, addr); 1161 break; 1162 1163 case PT_SETFPREGS: 1164 CTR2(KTR_PTRACE, "PT_SETFPREGS: tid %d (pid %d)", td2->td_tid, 1165 p->p_pid); 1166 td2->td_dbgflags |= TDB_USERWR; 1167 error = PROC_WRITE(fpregs, td2, addr); 1168 break; 1169 1170 case PT_GETFPREGS: 1171 CTR2(KTR_PTRACE, "PT_GETFPREGS: tid %d (pid %d)", td2->td_tid, 1172 p->p_pid); 1173 error = PROC_READ(fpregs, td2, addr); 1174 break; 1175 1176 case PT_SETDBREGS: 1177 CTR2(KTR_PTRACE, "PT_SETDBREGS: tid %d (pid %d)", td2->td_tid, 1178 p->p_pid); 1179 td2->td_dbgflags |= TDB_USERWR; 1180 error = PROC_WRITE(dbregs, td2, addr); 1181 break; 1182 1183 case PT_GETDBREGS: 1184 CTR2(KTR_PTRACE, "PT_GETDBREGS: tid %d (pid %d)", td2->td_tid, 1185 p->p_pid); 1186 error = PROC_READ(dbregs, td2, addr); 1187 break; 1188 1189 case PT_LWPINFO: 1190 if (data <= 0 || 1191#ifdef COMPAT_FREEBSD32 1192 (!wrap32 && data > sizeof(*pl)) || 1193 (wrap32 && data > sizeof(*pl32))) { 1194#else 1195 data > sizeof(*pl)) { 1196#endif 1197 error = EINVAL; 1198 break; 1199 } 1200#ifdef COMPAT_FREEBSD32 1201 if (wrap32) { 1202 pl = &plr; 1203 pl32 = addr; 1204 } else 1205#endif 1206 pl = addr; 1207 pl->pl_lwpid = td2->td_tid; 1208 pl->pl_event = PL_EVENT_NONE; 1209 pl->pl_flags = 0; 1210 if (td2->td_dbgflags & TDB_XSIG) { 1211 pl->pl_event = PL_EVENT_SIGNAL; 1212 if (td2->td_dbgksi.ksi_signo != 0 && 1213#ifdef COMPAT_FREEBSD32 1214 ((!wrap32 && data >= offsetof(struct ptrace_lwpinfo, 1215 pl_siginfo) + sizeof(pl->pl_siginfo)) || 1216 (wrap32 && data >= offsetof(struct ptrace_lwpinfo32, 1217 pl_siginfo) + sizeof(struct siginfo32))) 1218#else 1219 data >= offsetof(struct ptrace_lwpinfo, pl_siginfo) 1220 + sizeof(pl->pl_siginfo) 1221#endif 1222 ){ 1223 pl->pl_flags |= PL_FLAG_SI; 1224 pl->pl_siginfo = td2->td_dbgksi.ksi_info; 1225 } 1226 } 1227 if ((pl->pl_flags & PL_FLAG_SI) == 0) 1228 bzero(&pl->pl_siginfo, sizeof(pl->pl_siginfo)); 1229 if (td2->td_dbgflags & TDB_SCE) 1230 pl->pl_flags |= PL_FLAG_SCE; 1231 else if (td2->td_dbgflags & TDB_SCX) 1232 pl->pl_flags |= PL_FLAG_SCX; 1233 if (td2->td_dbgflags & TDB_EXEC) 1234 pl->pl_flags |= PL_FLAG_EXEC; 1235 if (td2->td_dbgflags & TDB_FORK) { 1236 pl->pl_flags |= PL_FLAG_FORKED; 1237 pl->pl_child_pid = td2->td_dbg_forked; 1238 } 1239 if (td2->td_dbgflags & TDB_CHILD) 1240 pl->pl_flags |= PL_FLAG_CHILD; 1241 if (td2->td_dbgflags & TDB_BORN) 1242 pl->pl_flags |= PL_FLAG_BORN; 1243 if (td2->td_dbgflags & TDB_EXIT) 1244 pl->pl_flags |= PL_FLAG_EXITED; 1245 pl->pl_sigmask = td2->td_sigmask; 1246 pl->pl_siglist = td2->td_siglist; 1247 strcpy(pl->pl_tdname, td2->td_name); 1248 if ((td2->td_dbgflags & (TDB_SCE | TDB_SCX)) != 0) { 1249 pl->pl_syscall_code = td2->td_dbg_sc_code; 1250 pl->pl_syscall_narg = td2->td_dbg_sc_narg; 1251 } else { 1252 pl->pl_syscall_code = 0; 1253 pl->pl_syscall_narg = 0; 1254 } 1255#ifdef COMPAT_FREEBSD32 1256 if (wrap32) 1257 ptrace_lwpinfo_to32(pl, pl32); 1258#endif 1259 CTR6(KTR_PTRACE, 1260 "PT_LWPINFO: tid %d (pid %d) event %d flags %#x child pid %d syscall %d", 1261 td2->td_tid, p->p_pid, pl->pl_event, pl->pl_flags, 1262 pl->pl_child_pid, pl->pl_syscall_code); 1263 break; 1264 1265 case PT_GETNUMLWPS: 1266 CTR2(KTR_PTRACE, "PT_GETNUMLWPS: pid %d: %d threads", p->p_pid, 1267 p->p_numthreads); 1268 td->td_retval[0] = p->p_numthreads; 1269 break; 1270 1271 case PT_GETLWPLIST: 1272 CTR3(KTR_PTRACE, "PT_GETLWPLIST: pid %d: data %d, actual %d", 1273 p->p_pid, data, p->p_numthreads); 1274 if (data <= 0) { 1275 error = EINVAL; 1276 break; 1277 } 1278 num = imin(p->p_numthreads, data); 1279 PROC_UNLOCK(p); 1280 buf = malloc(num * sizeof(lwpid_t), M_TEMP, M_WAITOK); 1281 tmp = 0; 1282 PROC_LOCK(p); 1283 FOREACH_THREAD_IN_PROC(p, td2) { 1284 if (tmp >= num) 1285 break; 1286 buf[tmp++] = td2->td_tid; 1287 } 1288 PROC_UNLOCK(p); 1289 error = copyout(buf, addr, tmp * sizeof(lwpid_t)); 1290 free(buf, M_TEMP); 1291 if (!error) 1292 td->td_retval[0] = tmp; 1293 PROC_LOCK(p); 1294 break; 1295 1296 case PT_VM_TIMESTAMP: 1297 CTR2(KTR_PTRACE, "PT_VM_TIMESTAMP: pid %d: timestamp %d", 1298 p->p_pid, p->p_vmspace->vm_map.timestamp); 1299 td->td_retval[0] = p->p_vmspace->vm_map.timestamp; 1300 break; 1301 1302 case PT_VM_ENTRY: 1303 PROC_UNLOCK(p); 1304#ifdef COMPAT_FREEBSD32 1305 if (wrap32) 1306 error = ptrace_vm_entry32(td, p, addr); 1307 else 1308#endif 1309 error = ptrace_vm_entry(td, p, addr); 1310 PROC_LOCK(p); 1311 break; 1312 1313 default: 1314#ifdef __HAVE_PTRACE_MACHDEP 1315 if (req >= PT_FIRSTMACH) { 1316 PROC_UNLOCK(p); 1317 error = cpu_ptrace(td2, req, addr, data); 1318 PROC_LOCK(p); 1319 } else 1320#endif 1321 /* Unknown request. */ 1322 error = EINVAL; 1323 break; 1324 } 1325 1326out: 1327 /* Drop our hold on this process now that the request has completed. */ 1328 _PRELE(p); 1329fail: 1330 PROC_UNLOCK(p); 1331 if (proctree_locked) 1332 sx_xunlock(&proctree_lock); 1333 return (error); 1334} 1335#undef PROC_READ 1336#undef PROC_WRITE 1337 1338/* 1339 * Stop a process because of a debugging event; 1340 * stay stopped until p->p_step is cleared 1341 * (cleared by PIOCCONT in procfs). 1342 */ 1343void 1344stopevent(struct proc *p, unsigned int event, unsigned int val) 1345{ 1346 1347 PROC_LOCK_ASSERT(p, MA_OWNED); 1348 p->p_step = 1; 1349 CTR3(KTR_PTRACE, "stopevent: pid %d event %u val %u", p->p_pid, event, 1350 val); 1351 do { 1352 p->p_xstat = val; 1353 p->p_xthread = NULL; 1354 p->p_stype = event; /* Which event caused the stop? */ 1355 wakeup(&p->p_stype); /* Wake up any PIOCWAIT'ing procs */ 1356 msleep(&p->p_step, &p->p_mtx, PWAIT, "stopevent", 0); 1357 } while (p->p_step); 1358} 1359