1 /*-
2 * Copyright (c) 1989, 1992, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * This code is derived from software developed by the Computer Systems
6 * Engineering group at Lawrence Berkeley Laboratory under DARPA contract
7 * BG 91-66 and contributed to Berkeley.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 * $FreeBSD: src/lib/libkvm/kvm_proc.c,v 1.25.2.3 2002/08/24 07:27:46 kris Exp $
34 *
35 * @(#)kvm_proc.c 8.3 (Berkeley) 9/23/93
36 */
37
38 /*
39 * Proc traversal interface for kvm. ps and w are (probably) the exclusive
40 * users of this code, so we've factored it out into a separate module.
41 * Thus, we keep this grunge out of the other kvm applications (i.e.,
42 * most other applications are interested only in open/close/read/nlist).
43 */
44
45 #include <sys/user.h> /* MUST BE FIRST */
46 #include <sys/conf.h>
47 #include <sys/param.h>
48 #include <sys/exec.h>
49 #include <sys/stat.h>
50 #include <sys/globaldata.h>
51 #include <sys/ioctl.h>
52 #include <sys/tty.h>
53 #include <sys/jail.h>
54 #include <fcntl.h>
55 #include <stdio.h>
56 #include <stdlib.h>
57 #include <stddef.h>
58 #include <unistd.h>
59 #include <nlist.h>
60
61 #include <cpu/pmap.h>
62 #include <vm/vm.h>
63 #include <vm/vm_param.h>
64 #include <vm/swap_pager.h>
65
66 #include <sys/sysctl.h>
67
68 #include <limits.h>
69 #include <memory.h>
70 #include <paths.h>
71
72 #include "kvm.h"
73 #include "kvm_private.h"
74
75 dev_t devid_from_dev(cdev_t dev);
76
77 #define KREAD(kd, addr, obj) \
78 (kvm_read(kd, addr, (char *)(obj), sizeof(*obj)) != sizeof(*obj))
79 #define KREADSTR(kd, addr) \
80 kvm_readstr(kd, (u_long)addr, NULL, NULL)
81
82 static struct kinfo_proc *
kinfo_resize_proc(kvm_t * kd,struct kinfo_proc * bp)83 kinfo_resize_proc(kvm_t *kd, struct kinfo_proc *bp)
84 {
85 if (bp < kd->procend)
86 return bp;
87
88 size_t pos = bp - kd->procend;
89 size_t size = kd->procend - kd->procbase;
90
91 if (size == 0)
92 size = 8;
93 else
94 size *= 2;
95 kd->procbase = _kvm_realloc(kd, kd->procbase, sizeof(*bp) * size);
96 if (kd->procbase == NULL)
97 return NULL;
98 kd->procend = kd->procbase + size;
99 bp = kd->procbase + pos;
100 return bp;
101 }
102
103 /*
104 * note: this function is also used by /usr/src/sys/kern/kern_kinfo.c as
105 * compiled by userland.
106 */
107 dev_t
devid_from_dev(cdev_t dev)108 devid_from_dev(cdev_t dev)
109 {
110 if (dev == NULL)
111 return NOUDEV;
112 if ((dev->si_umajor & 0xffffff00) ||
113 (dev->si_uminor & 0x0000ff00)) {
114 return NOUDEV;
115 }
116 return((dev->si_umajor << 8) | dev->si_uminor);
117 }
118
119 /*
120 * Helper routine which traverses the left hand side of a red-black sub-tree.
121 */
122 static uintptr_t
kvm_lwptraverse(kvm_t * kd,struct lwp * lwp,uintptr_t lwppos)123 kvm_lwptraverse(kvm_t *kd, struct lwp *lwp, uintptr_t lwppos)
124 {
125 for (;;) {
126 if (KREAD(kd, lwppos, lwp)) {
127 _kvm_err(kd, kd->program, "can't read lwp at %p",
128 (void *)lwppos);
129 return ((uintptr_t)-1);
130 }
131 if (lwp->u.lwp_rbnode.rbe_left == NULL)
132 break;
133 lwppos = (uintptr_t)lwp->u.lwp_rbnode.rbe_left;
134 }
135 return(lwppos);
136 }
137
138 /*
139 * Iterate LWPs in a process.
140 *
141 * The first lwp in a red-black tree is a left-side traversal of the tree.
142 */
143 static uintptr_t
kvm_firstlwp(kvm_t * kd,struct lwp * lwp,struct proc * proc)144 kvm_firstlwp(kvm_t *kd, struct lwp *lwp, struct proc *proc)
145 {
146 return(kvm_lwptraverse(kd, lwp, (uintptr_t)proc->p_lwp_tree.rbh_root));
147 }
148
149 /*
150 * If the current element is the left side of the parent the next element
151 * will be a left side traversal of the parent's right side. If the parent
152 * has no right side the next element will be the parent.
153 *
154 * If the current element is the right side of the parent the next element
155 * is the parent.
156 *
157 * If the parent is NULL we are done.
158 */
159 static uintptr_t
kvm_nextlwp(kvm_t * kd,uintptr_t lwppos,struct lwp * lwp)160 kvm_nextlwp(kvm_t *kd, uintptr_t lwppos, struct lwp *lwp)
161 {
162 uintptr_t nextpos;
163
164 nextpos = (uintptr_t)lwp->u.lwp_rbnode.rbe_parent;
165 if (nextpos) {
166 if (KREAD(kd, nextpos, lwp)) {
167 _kvm_err(kd, kd->program, "can't read lwp at %p",
168 (void *)lwppos);
169 return ((uintptr_t)-1);
170 }
171 if (lwppos == (uintptr_t)lwp->u.lwp_rbnode.rbe_left) {
172 /*
173 * If we had gone down the left side the next element
174 * is a left hand traversal of the parent's right
175 * side, or the parent itself if there is no right
176 * side.
177 */
178 lwppos = (uintptr_t)lwp->u.lwp_rbnode.rbe_right;
179 if (lwppos)
180 nextpos = kvm_lwptraverse(kd, lwp, lwppos);
181 } else {
182 /*
183 * If we had gone down the right side the next
184 * element is the parent.
185 */
186 /* nextpos = nextpos */
187 }
188 }
189 return(nextpos);
190 }
191
192 /*
193 * Read proc's from memory file into buffer bp, which has space to hold
194 * at most maxcnt procs.
195 */
196 static int
kvm_proclist(kvm_t * kd,int what,int arg,struct proc * p,struct kinfo_proc * bp)197 kvm_proclist(kvm_t *kd, int what, int arg, struct proc *p,
198 struct kinfo_proc *bp)
199 {
200 struct pgrp pgrp;
201 struct pgrp tpgrp;
202 struct globaldata gdata;
203 struct session sess;
204 struct session tsess;
205 struct tty tty;
206 struct proc proc;
207 struct ucred ucred;
208 struct thread thread;
209 struct proc pproc;
210 struct cdev cdev;
211 struct vmspace vmspace;
212 struct prison prison;
213 struct sigacts sigacts;
214 struct lwp lwp;
215 uintptr_t lwppos;
216 int count;
217 char *wmesg;
218
219 count = 0;
220
221 for (; p != NULL; p = proc.p_list.le_next) {
222 if (KREAD(kd, (u_long)p, &proc)) {
223 _kvm_err(kd, kd->program, "can't read proc at %p", p);
224 return (-1);
225 }
226 if (KREAD(kd, (u_long)proc.p_ucred, &ucred)) {
227 _kvm_err(kd, kd->program, "can't read ucred at %p",
228 proc.p_ucred);
229 return (-1);
230 }
231 proc.p_ucred = &ucred;
232
233 switch(what & ~KERN_PROC_FLAGMASK) {
234
235 case KERN_PROC_PID:
236 if (proc.p_pid != (pid_t)arg)
237 continue;
238 break;
239
240 case KERN_PROC_UID:
241 if (ucred.cr_uid != (uid_t)arg)
242 continue;
243 break;
244
245 case KERN_PROC_RUID:
246 if (ucred.cr_ruid != (uid_t)arg)
247 continue;
248 break;
249 }
250
251 if (KREAD(kd, (u_long)proc.p_pgrp, &pgrp)) {
252 _kvm_err(kd, kd->program, "can't read pgrp at %p",
253 proc.p_pgrp);
254 return (-1);
255 }
256 proc.p_pgrp = &pgrp;
257 if (proc.p_pptr) {
258 if (KREAD(kd, (u_long)proc.p_pptr, &pproc)) {
259 _kvm_err(kd, kd->program, "can't read pproc at %p",
260 proc.p_pptr);
261 return (-1);
262 }
263 proc.p_pptr = &pproc;
264 }
265
266 if (proc.p_sigacts) {
267 if (KREAD(kd, (u_long)proc.p_sigacts, &sigacts)) {
268 _kvm_err(kd, kd->program,
269 "can't read sigacts at %p",
270 proc.p_sigacts);
271 return (-1);
272 }
273 proc.p_sigacts = &sigacts;
274 }
275
276 if (KREAD(kd, (u_long)pgrp.pg_session, &sess)) {
277 _kvm_err(kd, kd->program, "can't read session at %p",
278 pgrp.pg_session);
279 return (-1);
280 }
281 pgrp.pg_session = &sess;
282
283 if ((proc.p_flags & P_CONTROLT) && sess.s_ttyp != NULL) {
284 if (KREAD(kd, (u_long)sess.s_ttyp, &tty)) {
285 _kvm_err(kd, kd->program,
286 "can't read tty at %p", sess.s_ttyp);
287 return (-1);
288 }
289 sess.s_ttyp = &tty;
290 if (tty.t_dev != NULL) {
291 if (KREAD(kd, (u_long)tty.t_dev, &cdev))
292 tty.t_dev = NULL;
293 else
294 tty.t_dev = &cdev;
295 }
296 if (tty.t_pgrp != NULL) {
297 if (KREAD(kd, (u_long)tty.t_pgrp, &tpgrp)) {
298 _kvm_err(kd, kd->program,
299 "can't read tpgrp at %p",
300 tty.t_pgrp);
301 return (-1);
302 }
303 tty.t_pgrp = &tpgrp;
304 }
305 if (tty.t_session != NULL) {
306 if (KREAD(kd, (u_long)tty.t_session, &tsess)) {
307 _kvm_err(kd, kd->program,
308 "can't read tsess at %p",
309 tty.t_session);
310 return (-1);
311 }
312 tty.t_session = &tsess;
313 }
314 }
315
316 if (KREAD(kd, (u_long)proc.p_vmspace, &vmspace)) {
317 _kvm_err(kd, kd->program, "can't read vmspace at %p",
318 proc.p_vmspace);
319 return (-1);
320 }
321 proc.p_vmspace = &vmspace;
322
323 if (ucred.cr_prison != NULL) {
324 if (KREAD(kd, (u_long)ucred.cr_prison, &prison)) {
325 _kvm_err(kd, kd->program, "can't read prison at %p",
326 ucred.cr_prison);
327 return (-1);
328 }
329 ucred.cr_prison = &prison;
330 }
331
332 switch (what & ~KERN_PROC_FLAGMASK) {
333
334 case KERN_PROC_PGRP:
335 if (proc.p_pgrp->pg_id != (pid_t)arg)
336 continue;
337 break;
338
339 case KERN_PROC_TTY:
340 if ((proc.p_flags & P_CONTROLT) == 0 ||
341 devid_from_dev(proc.p_pgrp->pg_session->s_ttyp->t_dev)
342 != (dev_t)arg)
343 continue;
344 break;
345 }
346
347 if ((bp = kinfo_resize_proc(kd, bp)) == NULL)
348 return (-1);
349 fill_kinfo_proc(&proc, bp);
350 bp->kp_paddr = (uintptr_t)p;
351
352 lwppos = kvm_firstlwp(kd, &lwp, &proc);
353 if (lwppos == 0) {
354 bp++; /* Just export the proc then */
355 count++;
356 }
357 while (lwppos && lwppos != (uintptr_t)-1) {
358 if (p != lwp.lwp_proc) {
359 _kvm_err(kd, kd->program, "lwp has wrong parent");
360 return (-1);
361 }
362 lwp.lwp_proc = &proc;
363 if (KREAD(kd, (u_long)lwp.lwp_thread, &thread)) {
364 _kvm_err(kd, kd->program, "can't read thread at %p",
365 lwp.lwp_thread);
366 return (-1);
367 }
368 lwp.lwp_thread = &thread;
369
370 if (thread.td_gd) {
371 if (KREAD(kd, (u_long)thread.td_gd, &gdata)) {
372 _kvm_err(kd, kd->program, "can't read"
373 " gd at %p",
374 thread.td_gd);
375 return(-1);
376 }
377 thread.td_gd = &gdata;
378 }
379 if (thread.td_wmesg) {
380 wmesg = (void *)KREADSTR(kd, thread.td_wmesg);
381 if (wmesg == NULL) {
382 _kvm_err(kd, kd->program, "can't read"
383 " wmesg %p",
384 thread.td_wmesg);
385 return(-1);
386 }
387 thread.td_wmesg = wmesg;
388 } else {
389 wmesg = NULL;
390 }
391
392 if ((bp = kinfo_resize_proc(kd, bp)) == NULL)
393 return (-1);
394 fill_kinfo_proc(&proc, bp);
395 fill_kinfo_lwp(&lwp, &bp->kp_lwp);
396 bp->kp_paddr = (uintptr_t)p;
397 bp++;
398 count++;
399 if (wmesg)
400 free(wmesg);
401 if ((what & KERN_PROC_FLAG_LWP) == 0)
402 break;
403 lwppos = kvm_nextlwp(kd, lwppos, &lwp);
404 }
405 if (lwppos == (uintptr_t)-1)
406 return(-1);
407 }
408 return (count);
409 }
410
411 /*
412 * Build proc info array by reading in proc list from a crash dump.
413 * We reallocate kd->procbase as necessary.
414 */
415 static int
kvm_deadprocs(kvm_t * kd,int what,int arg,int allproc_hsize,long procglob)416 kvm_deadprocs(kvm_t *kd, int what, int arg, int allproc_hsize, long procglob)
417 {
418 struct kinfo_proc *bp;
419 struct proc *p;
420 struct proclist **pl;
421 int cnt, partcnt, n;
422 u_long nextoff;
423 u_long a_allproc;
424
425 cnt = partcnt = 0;
426 nextoff = 0;
427
428 /*
429 * Dynamically allocate space for all the elements of the
430 * allprocs array and KREAD() them.
431 */
432 pl = _kvm_malloc(kd, allproc_hsize * sizeof(struct proclist *));
433 for (n = 0; n < allproc_hsize; n++) {
434 pl[n] = _kvm_malloc(kd, sizeof(struct proclist));
435 a_allproc = procglob +
436 sizeof(struct procglob) * n +
437 offsetof(struct procglob, allproc);
438 nextoff = a_allproc;
439 if (KREAD(kd, (u_long)nextoff, pl[n])) {
440 _kvm_err(kd, kd->program, "can't read proclist at 0x%lx",
441 a_allproc);
442 return (-1);
443 }
444
445 /* Ignore empty proclists */
446 if (LIST_EMPTY(pl[n]))
447 continue;
448
449 bp = kd->procbase + cnt;
450 p = pl[n]->lh_first;
451 partcnt = kvm_proclist(kd, what, arg, p, bp);
452 if (partcnt < 0) {
453 free(pl[n]);
454 return (partcnt);
455 }
456
457 cnt += partcnt;
458 free(pl[n]);
459 }
460
461 return (cnt);
462 }
463
464 struct kinfo_proc *
kvm_getprocs(kvm_t * kd,int op,int arg,int * cnt)465 kvm_getprocs(kvm_t *kd, int op, int arg, int *cnt)
466 {
467 int mib[4], st, nprocs, allproc_hsize;
468 int miblen = ((op & ~KERN_PROC_FLAGMASK) == KERN_PROC_ALL) ? 3 : 4;
469 size_t size;
470
471 if (kd->procbase != NULL) {
472 free(kd->procbase);
473 kd->procbase = NULL;
474 }
475 if (kvm_ishost(kd)) {
476 size = 0;
477 mib[0] = CTL_KERN;
478 mib[1] = KERN_PROC;
479 mib[2] = op;
480 mib[3] = arg;
481 st = sysctl(mib, miblen, NULL, &size, NULL, 0);
482 if (st == -1) {
483 _kvm_syserr(kd, kd->program, "kvm_getprocs");
484 return (0);
485 }
486 do {
487 size += size / 10;
488 kd->procbase = (struct kinfo_proc *)
489 _kvm_realloc(kd, kd->procbase, size);
490 if (kd->procbase == 0)
491 return (0);
492 st = sysctl(mib, miblen, kd->procbase, &size, NULL, 0);
493 } while (st == -1 && errno == ENOMEM);
494 if (st == -1) {
495 _kvm_syserr(kd, kd->program, "kvm_getprocs");
496 return (0);
497 }
498 if (size % sizeof(struct kinfo_proc) != 0) {
499 _kvm_err(kd, kd->program,
500 "proc size mismatch (%zd total, %zd chunks)",
501 size, sizeof(struct kinfo_proc));
502 return (0);
503 }
504 nprocs = size / sizeof(struct kinfo_proc);
505 } else {
506 struct nlist nl[4], *p;
507 u_long procglob;
508
509 nl[0].n_name = "_nprocs";
510 nl[1].n_name = "_procglob";
511 nl[2].n_name = "_allproc_hsize";
512 nl[3].n_name = 0;
513
514 if (kvm_nlist(kd, nl) != 0) {
515 for (p = nl; p->n_type != 0; ++p)
516 ;
517 _kvm_err(kd, kd->program,
518 "%s: no such symbol", p->n_name);
519 return (0);
520 }
521 if (KREAD(kd, nl[0].n_value, &nprocs)) {
522 _kvm_err(kd, kd->program, "can't read nprocs");
523 return (0);
524 }
525 if (KREAD(kd, nl[2].n_value, &allproc_hsize)) {
526 _kvm_err(kd, kd->program, "can't read allproc_hsize");
527 return (0);
528 }
529 procglob = nl[1].n_value;
530 nprocs = kvm_deadprocs(kd, op, arg, allproc_hsize, procglob);
531 #ifdef notdef
532 size = nprocs * sizeof(struct kinfo_proc);
533 (void)realloc(kd->procbase, size);
534 #endif
535 }
536 *cnt = nprocs;
537 return (kd->procbase);
538 }
539
540 void
_kvm_freeprocs(kvm_t * kd)541 _kvm_freeprocs(kvm_t *kd)
542 {
543 if (kd->procbase) {
544 free(kd->procbase);
545 kd->procbase = 0;
546 }
547 }
548
549 void *
_kvm_realloc(kvm_t * kd,void * p,size_t n)550 _kvm_realloc(kvm_t *kd, void *p, size_t n)
551 {
552 void *np = (void *)realloc(p, n);
553
554 if (np == NULL) {
555 free(p);
556 _kvm_err(kd, kd->program, "out of memory");
557 }
558 return (np);
559 }
560
561 #ifndef MAX
562 #define MAX(a, b) ((a) > (b) ? (a) : (b))
563 #endif
564
565 /*
566 * Read in an argument vector from the user address space of process pid.
567 * addr if the user-space base address of narg null-terminated contiguous
568 * strings. This is used to read in both the command arguments and
569 * environment strings. Read at most maxcnt characters of strings.
570 */
571 static char **
kvm_argv(kvm_t * kd,pid_t pid,u_long addr,int narg,int maxcnt)572 kvm_argv(kvm_t *kd, pid_t pid, u_long addr, int narg, int maxcnt)
573 {
574 char *np, *cp, *ep, *ap;
575 u_long oaddr = -1;
576 u_long addr_min = VM_MIN_USER_ADDRESS;
577 u_long addr_max = VM_MAX_USER_ADDRESS;
578 int len, cc;
579 char **argv;
580
581 /*
582 * Check that there aren't an unreasonable number of agruments,
583 * and that the address is in user space.
584 */
585 if (narg > 512 || addr < addr_min || addr >= addr_max)
586 return (0);
587
588 /*
589 * kd->argv : work space for fetching the strings from the target
590 * process's space, and is converted for returning to caller
591 */
592 if (kd->argv == 0) {
593 /*
594 * Try to avoid reallocs.
595 */
596 kd->argc = MAX(narg + 1, 32);
597 kd->argv = (char **)_kvm_malloc(kd, kd->argc *
598 sizeof(*kd->argv));
599 if (kd->argv == 0)
600 return (0);
601 } else if (narg + 1 > kd->argc) {
602 kd->argc = MAX(2 * kd->argc, narg + 1);
603 kd->argv = (char **)_kvm_realloc(kd, kd->argv, kd->argc *
604 sizeof(*kd->argv));
605 if (kd->argv == 0)
606 return (0);
607 }
608 /*
609 * kd->argspc : returned to user, this is where the kd->argv
610 * arrays are left pointing to the collected strings.
611 */
612 if (kd->argspc == 0) {
613 kd->argspc = (char *)_kvm_malloc(kd, PAGE_SIZE);
614 if (kd->argspc == 0)
615 return (0);
616 kd->arglen = PAGE_SIZE;
617 }
618 /*
619 * kd->argbuf : used to pull in pages from the target process.
620 * the strings are copied out of here.
621 */
622 if (kd->argbuf == 0) {
623 kd->argbuf = (char *)_kvm_malloc(kd, PAGE_SIZE);
624 if (kd->argbuf == 0)
625 return (0);
626 }
627
628 /* Pull in the target process'es argv vector */
629 cc = sizeof(char *) * narg;
630 if (kvm_uread(kd, pid, addr, (char *)kd->argv, cc) != cc)
631 return (0);
632 /*
633 * ap : saved start address of string we're working on in kd->argspc
634 * np : pointer to next place to write in kd->argspc
635 * len: length of data in kd->argspc
636 * argv: pointer to the argv vector that we are hunting around the
637 * target process space for, and converting to addresses in
638 * our address space (kd->argspc).
639 */
640 ap = np = kd->argspc;
641 argv = kd->argv;
642 len = 0;
643 /*
644 * Loop over pages, filling in the argument vector.
645 * Note that the argv strings could be pointing *anywhere* in
646 * the user address space and are no longer contiguous.
647 * Note that *argv is modified when we are going to fetch a string
648 * that crosses a page boundary. We copy the next part of the string
649 * into to "np" and eventually convert the pointer.
650 */
651 while (argv < kd->argv + narg && *argv != NULL) {
652
653 /* get the address that the current argv string is on */
654 addr = rounddown2((u_long)*argv, PAGE_SIZE);
655
656 /* is it the same page as the last one? */
657 if (addr != oaddr) {
658 if (kvm_uread(kd, pid, addr, kd->argbuf, PAGE_SIZE) !=
659 PAGE_SIZE)
660 return (0);
661 oaddr = addr;
662 }
663
664 /* offset within the page... kd->argbuf */
665 addr = (u_long)*argv & (PAGE_SIZE - 1);
666
667 /* cp = start of string, cc = count of chars in this chunk */
668 cp = kd->argbuf + addr;
669 cc = PAGE_SIZE - addr;
670
671 /* dont get more than asked for by user process */
672 if (maxcnt > 0 && cc > maxcnt - len)
673 cc = maxcnt - len;
674
675 /* pointer to end of string if we found it in this page */
676 ep = memchr(cp, '\0', cc);
677 if (ep != NULL)
678 cc = ep - cp + 1;
679 /*
680 * at this point, cc is the count of the chars that we are
681 * going to retrieve this time. we may or may not have found
682 * the end of it. (ep points to the null if the end is known)
683 */
684
685 /* will we exceed the malloc/realloced buffer? */
686 if (len + cc > kd->arglen) {
687 size_t off;
688 char **pp;
689 char *op = kd->argspc;
690
691 kd->arglen *= 2;
692 kd->argspc = (char *)_kvm_realloc(kd, kd->argspc,
693 kd->arglen);
694 if (kd->argspc == 0)
695 return (0);
696 /*
697 * Adjust argv pointers in case realloc moved
698 * the string space.
699 */
700 off = kd->argspc - op;
701 for (pp = kd->argv; pp < argv; pp++)
702 *pp += off;
703 ap += off;
704 np += off;
705 }
706 /* np = where to put the next part of the string in kd->argspc*/
707 /* np is kinda redundant.. could use "kd->argspc + len" */
708 memcpy(np, cp, cc);
709 np += cc; /* inc counters */
710 len += cc;
711
712 /*
713 * if end of string found, set the *argv pointer to the
714 * saved beginning of string, and advance. argv points to
715 * somewhere in kd->argv.. This is initially relative
716 * to the target process, but when we close it off, we set
717 * it to point in our address space.
718 */
719 if (ep != NULL) {
720 *argv++ = ap;
721 ap = np;
722 } else {
723 /* update the address relative to the target process */
724 *argv += cc;
725 }
726
727 if (maxcnt > 0 && len >= maxcnt) {
728 /*
729 * We're stopping prematurely. Terminate the
730 * current string.
731 */
732 if (ep == NULL) {
733 *np = '\0';
734 *argv++ = ap;
735 }
736 break;
737 }
738 }
739 /* Make sure argv is terminated. */
740 *argv = NULL;
741 return (kd->argv);
742 }
743
744 static void
ps_str_a(struct ps_strings * p,u_long * addr,int * n)745 ps_str_a(struct ps_strings *p, u_long *addr, int *n)
746 {
747 *addr = (u_long)p->ps_argvstr;
748 *n = p->ps_nargvstr;
749 }
750
751 static void
ps_str_e(struct ps_strings * p,u_long * addr,int * n)752 ps_str_e(struct ps_strings *p, u_long *addr, int *n)
753 {
754 *addr = (u_long)p->ps_envstr;
755 *n = p->ps_nenvstr;
756 }
757
758 /*
759 * Determine if the proc indicated by p is still active.
760 * This test is not 100% foolproof in theory, but chances of
761 * being wrong are very low.
762 */
763 static int
proc_verify(const struct kinfo_proc * p)764 proc_verify(const struct kinfo_proc *p)
765 {
766 struct kinfo_proc kp;
767 int mib[4];
768 size_t len;
769 int error;
770
771 mib[0] = CTL_KERN;
772 mib[1] = KERN_PROC;
773 mib[2] = KERN_PROC_PID;
774 mib[3] = p->kp_pid;
775
776 len = sizeof(kp);
777 error = sysctl(mib, 4, &kp, &len, NULL, 0);
778 if (error)
779 return (0);
780
781 error = (p->kp_pid == kp.kp_pid &&
782 (kp.kp_stat != SZOMB || p->kp_stat == SZOMB));
783 return (error);
784 }
785
786 static char **
kvm_doargv(kvm_t * kd,const struct kinfo_proc * kp,int nchr,void (* info)(struct ps_strings *,u_long *,int *))787 kvm_doargv(kvm_t *kd, const struct kinfo_proc *kp, int nchr,
788 void (*info)(struct ps_strings *, u_long *, int *))
789 {
790 char **ap;
791 u_long addr;
792 int cnt;
793 static struct ps_strings arginfo;
794 static u_long ps_strings;
795 size_t len;
796
797 if (ps_strings == 0) {
798 len = sizeof(ps_strings);
799 if (sysctlbyname("kern.ps_strings", &ps_strings, &len, NULL,
800 0) == -1)
801 ps_strings = PS_STRINGS;
802 }
803
804 /*
805 * Pointers are stored at the top of the user stack.
806 */
807 if (kp->kp_stat == SZOMB ||
808 kvm_uread(kd, kp->kp_pid, ps_strings, (char *)&arginfo,
809 sizeof(arginfo)) != sizeof(arginfo))
810 return (0);
811
812 (*info)(&arginfo, &addr, &cnt);
813 if (cnt == 0)
814 return (0);
815 ap = kvm_argv(kd, kp->kp_pid, addr, cnt, nchr);
816 /*
817 * For live kernels, make sure this process didn't go away.
818 */
819 if (ap != NULL && (kvm_ishost(kd) || kvm_isvkernel(kd)) &&
820 !proc_verify(kp))
821 ap = NULL;
822 return (ap);
823 }
824
825 /*
826 * Get the command args. This code is now machine independent.
827 */
828 char **
kvm_getargv(kvm_t * kd,const struct kinfo_proc * kp,int nchr)829 kvm_getargv(kvm_t *kd, const struct kinfo_proc *kp, int nchr)
830 {
831 int oid[8];
832 int i;
833 size_t bufsz;
834 static unsigned long buflen;
835 static char *buf, *p;
836 static char **bufp;
837 static int argc;
838
839 if (!kvm_ishost(kd)) { /* XXX: vkernels */
840 _kvm_err(kd, kd->program,
841 "cannot read user space from dead kernel");
842 return (0);
843 }
844
845 if (!buflen) {
846 bufsz = sizeof(buflen);
847 i = sysctlbyname("kern.ps_arg_cache_limit",
848 &buflen, &bufsz, NULL, 0);
849 if (i == -1) {
850 buflen = 0;
851 } else {
852 buf = malloc(buflen);
853 if (buf == NULL)
854 buflen = 0;
855 argc = 32;
856 bufp = malloc(sizeof(char *) * argc);
857 }
858 }
859 if (buf != NULL) {
860 oid[0] = CTL_KERN;
861 oid[1] = KERN_PROC;
862 oid[2] = KERN_PROC_ARGS;
863 oid[3] = kp->kp_pid;
864 oid[4] = kp->kp_lwp.kl_tid;
865
866 /*
867 * sysctl can take a pid in 5.7 or earlier. In late
868 * 5.7 the sysctl can take a pid (4 args) or pid + tid
869 * (5 args).
870 */
871 i = -1;
872 if (kp->kp_lwp.kl_tid > 0) {
873 bufsz = buflen;
874 i = sysctl(oid, 5, buf, &bufsz, 0, 0);
875 }
876 if (i < 0) {
877 bufsz = buflen;
878 i = sysctl(oid, 4, buf, &bufsz, 0, 0);
879 }
880
881 if (i == 0 && bufsz > 0) {
882 i = 0;
883 p = buf;
884 do {
885 bufp[i++] = p;
886 p += strlen(p) + 1;
887 if (i >= argc) {
888 argc += argc;
889 bufp = realloc(bufp,
890 sizeof(char *) * argc);
891 }
892 } while (p < buf + bufsz);
893 bufp[i++] = NULL;
894 return (bufp);
895 }
896 }
897 if (kp->kp_flags & P_SYSTEM)
898 return (NULL);
899 return (kvm_doargv(kd, kp, nchr, ps_str_a));
900 }
901
902 char **
kvm_getenvv(kvm_t * kd,const struct kinfo_proc * kp,int nchr)903 kvm_getenvv(kvm_t *kd, const struct kinfo_proc *kp, int nchr)
904 {
905 return (kvm_doargv(kd, kp, nchr, ps_str_e));
906 }
907
908 /*
909 * Read from user space. The user context is given by pid.
910 */
911 ssize_t
kvm_uread(kvm_t * kd,pid_t pid,u_long uva,char * buf,size_t len)912 kvm_uread(kvm_t *kd, pid_t pid, u_long uva, char *buf, size_t len)
913 {
914 char *cp;
915 char procfile[MAXPATHLEN];
916 ssize_t amount;
917 int fd;
918
919 if (!kvm_ishost(kd)) { /* XXX: vkernels */
920 _kvm_err(kd, kd->program,
921 "cannot read user space from dead kernel");
922 return (0);
923 }
924
925 sprintf(procfile, "/proc/%d/mem", pid);
926 fd = open(procfile, O_RDONLY, 0);
927 if (fd < 0) {
928 _kvm_err(kd, kd->program, "cannot open %s", procfile);
929 close(fd);
930 return (0);
931 }
932
933 cp = buf;
934 while (len > 0) {
935 errno = 0;
936 if (lseek(fd, (off_t)uva, 0) == -1 && errno != 0) {
937 _kvm_err(kd, kd->program, "invalid address (%lx) in %s",
938 uva, procfile);
939 break;
940 }
941 amount = read(fd, cp, len);
942 if (amount < 0) {
943 _kvm_syserr(kd, kd->program, "error reading %s",
944 procfile);
945 break;
946 }
947 if (amount == 0) {
948 _kvm_err(kd, kd->program, "EOF reading %s", procfile);
949 break;
950 }
951 cp += amount;
952 uva += amount;
953 len -= amount;
954 }
955
956 close(fd);
957 return ((ssize_t)(cp - buf));
958 }
959