FreeBSD/Linux Kernel Cross Reference
sys/net/vnet.c
1 /*-
2 * Copyright (c) 2004-2009 University of Zagreb
3 * Copyright (c) 2006-2009 FreeBSD Foundation
4 * All rights reserved.
5 *
6 * This software was developed by the University of Zagreb and the
7 * FreeBSD Foundation under sponsorship by the Stichting NLnet and the
8 * FreeBSD Foundation.
9 *
10 * Copyright (c) 2009 Jeffrey Roberson <jeff@freebsd.org>
11 * Copyright (c) 2009 Robert N. M. Watson
12 * All rights reserved.
13 *
14 * Redistribution and use in source and binary forms, with or without
15 * modification, are permitted provided that the following conditions
16 * are met:
17 * 1. Redistributions of source code must retain the above copyright
18 * notice, this list of conditions and the following disclaimer.
19 * 2. Redistributions in binary form must reproduce the above copyright
20 * notice, this list of conditions and the following disclaimer in the
21 * documentation and/or other materials provided with the distribution.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36 #include <sys/cdefs.h>
37 __FBSDID("$FreeBSD: releng/10.1/sys/net/vnet.c 262734 2014-03-04 14:01:12Z glebius $");
38
39 #include "opt_ddb.h"
40 #include "opt_kdb.h"
41 #include "opt_kdtrace.h"
42
43 #include <sys/param.h>
44 #include <sys/kdb.h>
45 #include <sys/kernel.h>
46 #include <sys/jail.h>
47 #include <sys/sdt.h>
48 #include <sys/systm.h>
49 #include <sys/sysctl.h>
50 #include <sys/eventhandler.h>
51 #include <sys/lock.h>
52 #include <sys/malloc.h>
53 #include <sys/proc.h>
54 #include <sys/socket.h>
55 #include <sys/sx.h>
56 #include <sys/sysctl.h>
57
58 #include <machine/stdarg.h>
59
60 #ifdef DDB
61 #include <ddb/ddb.h>
62 #include <ddb/db_sym.h>
63 #endif
64
65 #include <net/if.h>
66 #include <net/if_var.h>
67 #include <net/vnet.h>
68
69 /*-
70 * This file implements core functions for virtual network stacks:
71 *
72 * - Virtual network stack management functions.
73 *
74 * - Virtual network stack memory allocator, which virtualizes global
75 * variables in the network stack
76 *
77 * - Virtualized SYSINIT's/SYSUNINIT's, which allow network stack subsystems
78 * to register startup/shutdown events to be run for each virtual network
79 * stack instance.
80 */
81
82 FEATURE(vimage, "VIMAGE kernel virtualization");
83
84 static MALLOC_DEFINE(M_VNET, "vnet", "network stack control block");
85
86 /*
87 * The virtual network stack list has two read-write locks, one sleepable and
88 * the other not, so that the list can be stablized and walked in a variety
89 * of network stack contexts. Both must be acquired exclusively to modify
90 * the list, but a read lock of either lock is sufficient to walk the list.
91 */
92 struct rwlock vnet_rwlock;
93 struct sx vnet_sxlock;
94
95 #define VNET_LIST_WLOCK() do { \
96 sx_xlock(&vnet_sxlock); \
97 rw_wlock(&vnet_rwlock); \
98 } while (0)
99
100 #define VNET_LIST_WUNLOCK() do { \
101 rw_wunlock(&vnet_rwlock); \
102 sx_xunlock(&vnet_sxlock); \
103 } while (0)
104
105 struct vnet_list_head vnet_head;
106 struct vnet *vnet0;
107
108 /*
109 * The virtual network stack allocator provides storage for virtualized
110 * global variables. These variables are defined/declared using the
111 * VNET_DEFINE()/VNET_DECLARE() macros, which place them in the 'set_vnet'
112 * linker set. The details of the implementation are somewhat subtle, but
113 * allow the majority of most network subsystems to maintain
114 * virtualization-agnostic.
115 *
116 * The virtual network stack allocator handles variables in the base kernel
117 * vs. modules in similar but different ways. In both cases, virtualized
118 * global variables are marked as such by being declared to be part of the
119 * vnet linker set. These "master" copies of global variables serve two
120 * functions:
121 *
122 * (1) They contain static initialization or "default" values for global
123 * variables which will be propagated to each virtual network stack
124 * instance when created. As with normal global variables, they default
125 * to zero-filled.
126 *
127 * (2) They act as unique global names by which the variable can be referred
128 * to, regardless of network stack instance. The single global symbol
129 * will be used to calculate the location of a per-virtual instance
130 * variable at run-time.
131 *
132 * Each virtual network stack instance has a complete copy of each
133 * virtualized global variable, stored in a malloc'd block of memory
134 * referred to by vnet->vnet_data_mem. Critical to the design is that each
135 * per-instance memory block is laid out identically to the master block so
136 * that the offset of each global variable is the same across all blocks. To
137 * optimize run-time access, a precalculated 'base' address,
138 * vnet->vnet_data_base, is stored in each vnet, and is the amount that can
139 * be added to the address of a 'master' instance of a variable to get to the
140 * per-vnet instance.
141 *
142 * Virtualized global variables are handled in a similar manner, but as each
143 * module has its own 'set_vnet' linker set, and we want to keep all
144 * virtualized globals togther, we reserve space in the kernel's linker set
145 * for potential module variables using a per-vnet character array,
146 * 'modspace'. The virtual network stack allocator maintains a free list to
147 * track what space in the array is free (all, initially) and as modules are
148 * linked, allocates portions of the space to specific globals. The kernel
149 * module linker queries the virtual network stack allocator and will
150 * bind references of the global to the location during linking. It also
151 * calls into the virtual network stack allocator, once the memory is
152 * initialized, in order to propagate the new static initializations to all
153 * existing virtual network stack instances so that the soon-to-be executing
154 * module will find every network stack instance with proper default values.
155 */
156
157 /*
158 * Number of bytes of data in the 'set_vnet' linker set, and hence the total
159 * size of all kernel virtualized global variables, and the malloc(9) type
160 * that will be used to allocate it.
161 */
162 #define VNET_BYTES (VNET_STOP - VNET_START)
163
164 static MALLOC_DEFINE(M_VNET_DATA, "vnet_data", "VNET data");
165
166 /*
167 * VNET_MODMIN is the minimum number of bytes we will reserve for the sum of
168 * global variables across all loaded modules. As this actually sizes an
169 * array declared as a virtualized global variable in the kernel itself, and
170 * we want the virtualized global variable space to be page-sized, we may
171 * have more space than that in practice.
172 */
173 #define VNET_MODMIN 8192
174 #define VNET_SIZE roundup2(VNET_BYTES, PAGE_SIZE)
175 #define VNET_MODSIZE (VNET_SIZE - (VNET_BYTES - VNET_MODMIN))
176
177 /*
178 * Space to store virtualized global variables from loadable kernel modules,
179 * and the free list to manage it.
180 */
181 static VNET_DEFINE(char, modspace[VNET_MODMIN]);
182
183 /*
184 * Global lists of subsystem constructor and destructors for vnets. They are
185 * registered via VNET_SYSINIT() and VNET_SYSUNINIT(). Both lists are
186 * protected by the vnet_sysinit_sxlock global lock.
187 */
188 static TAILQ_HEAD(vnet_sysinit_head, vnet_sysinit) vnet_constructors =
189 TAILQ_HEAD_INITIALIZER(vnet_constructors);
190 static TAILQ_HEAD(vnet_sysuninit_head, vnet_sysinit) vnet_destructors =
191 TAILQ_HEAD_INITIALIZER(vnet_destructors);
192
193 struct sx vnet_sysinit_sxlock;
194
195 #define VNET_SYSINIT_WLOCK() sx_xlock(&vnet_sysinit_sxlock);
196 #define VNET_SYSINIT_WUNLOCK() sx_xunlock(&vnet_sysinit_sxlock);
197 #define VNET_SYSINIT_RLOCK() sx_slock(&vnet_sysinit_sxlock);
198 #define VNET_SYSINIT_RUNLOCK() sx_sunlock(&vnet_sysinit_sxlock);
199
200 struct vnet_data_free {
201 uintptr_t vnd_start;
202 int vnd_len;
203 TAILQ_ENTRY(vnet_data_free) vnd_link;
204 };
205
206 static MALLOC_DEFINE(M_VNET_DATA_FREE, "vnet_data_free",
207 "VNET resource accounting");
208 static TAILQ_HEAD(, vnet_data_free) vnet_data_free_head =
209 TAILQ_HEAD_INITIALIZER(vnet_data_free_head);
210 static struct sx vnet_data_free_lock;
211
212 SDT_PROVIDER_DEFINE(vnet);
213 SDT_PROBE_DEFINE1(vnet, functions, vnet_alloc, entry, "int");
214 SDT_PROBE_DEFINE2(vnet, functions, vnet_alloc, alloc, "int",
215 "struct vnet *");
216 SDT_PROBE_DEFINE2(vnet, functions, vnet_alloc, return,
217 "int", "struct vnet *");
218 SDT_PROBE_DEFINE2(vnet, functions, vnet_destroy, entry,
219 "int", "struct vnet *");
220 SDT_PROBE_DEFINE1(vnet, functions, vnet_destroy, return,
221 "int");
222
223 #ifdef DDB
224 static void db_show_vnet_print_vs(struct vnet_sysinit *, int);
225 #endif
226
227 /*
228 * Allocate a virtual network stack.
229 */
230 struct vnet *
231 vnet_alloc(void)
232 {
233 struct vnet *vnet;
234
235 SDT_PROBE1(vnet, functions, vnet_alloc, entry, __LINE__);
236 vnet = malloc(sizeof(struct vnet), M_VNET, M_WAITOK | M_ZERO);
237 vnet->vnet_magic_n = VNET_MAGIC_N;
238 SDT_PROBE2(vnet, functions, vnet_alloc, alloc, __LINE__, vnet);
239
240 /*
241 * Allocate storage for virtualized global variables and copy in
242 * initial values form our 'master' copy.
243 */
244 vnet->vnet_data_mem = malloc(VNET_SIZE, M_VNET_DATA, M_WAITOK);
245 memcpy(vnet->vnet_data_mem, (void *)VNET_START, VNET_BYTES);
246
247 /*
248 * All use of vnet-specific data will immediately subtract VNET_START
249 * from the base memory pointer, so pre-calculate that now to avoid
250 * it on each use.
251 */
252 vnet->vnet_data_base = (uintptr_t)vnet->vnet_data_mem - VNET_START;
253
254 /* Initialize / attach vnet module instances. */
255 CURVNET_SET_QUIET(vnet);
256 vnet_sysinit();
257 CURVNET_RESTORE();
258
259 VNET_LIST_WLOCK();
260 LIST_INSERT_HEAD(&vnet_head, vnet, vnet_le);
261 VNET_LIST_WUNLOCK();
262
263 SDT_PROBE2(vnet, functions, vnet_alloc, return, __LINE__, vnet);
264 return (vnet);
265 }
266
267 /*
268 * Destroy a virtual network stack.
269 */
270 void
271 vnet_destroy(struct vnet *vnet)
272 {
273 struct ifnet *ifp, *nifp;
274
275 SDT_PROBE2(vnet, functions, vnet_destroy, entry, __LINE__, vnet);
276 KASSERT(vnet->vnet_sockcnt == 0,
277 ("%s: vnet still has sockets", __func__));
278
279 VNET_LIST_WLOCK();
280 LIST_REMOVE(vnet, vnet_le);
281 VNET_LIST_WUNLOCK();
282
283 CURVNET_SET_QUIET(vnet);
284
285 /* Return all inherited interfaces to their parent vnets. */
286 TAILQ_FOREACH_SAFE(ifp, &V_ifnet, if_link, nifp) {
287 if (ifp->if_home_vnet != ifp->if_vnet)
288 if_vmove(ifp, ifp->if_home_vnet);
289 }
290
291 vnet_sysuninit();
292 CURVNET_RESTORE();
293
294 /*
295 * Release storage for the virtual network stack instance.
296 */
297 free(vnet->vnet_data_mem, M_VNET_DATA);
298 vnet->vnet_data_mem = NULL;
299 vnet->vnet_data_base = 0;
300 vnet->vnet_magic_n = 0xdeadbeef;
301 free(vnet, M_VNET);
302 SDT_PROBE1(vnet, functions, vnet_destroy, return, __LINE__);
303 }
304
305 /*
306 * Boot time initialization and allocation of virtual network stacks.
307 */
308 static void
309 vnet_init_prelink(void *arg)
310 {
311
312 rw_init(&vnet_rwlock, "vnet_rwlock");
313 sx_init(&vnet_sxlock, "vnet_sxlock");
314 sx_init(&vnet_sysinit_sxlock, "vnet_sysinit_sxlock");
315 LIST_INIT(&vnet_head);
316 }
317 SYSINIT(vnet_init_prelink, SI_SUB_VNET_PRELINK, SI_ORDER_FIRST,
318 vnet_init_prelink, NULL);
319
320 static void
321 vnet0_init(void *arg)
322 {
323
324 /* Warn people before take off - in case we crash early. */
325 printf("WARNING: VIMAGE (virtualized network stack) is a highly "
326 "experimental feature.\n");
327
328 /*
329 * We MUST clear curvnet in vi_init_done() before going SMP,
330 * otherwise CURVNET_SET() macros would scream about unnecessary
331 * curvnet recursions.
332 */
333 curvnet = prison0.pr_vnet = vnet0 = vnet_alloc();
334 }
335 SYSINIT(vnet0_init, SI_SUB_VNET, SI_ORDER_FIRST, vnet0_init, NULL);
336
337 static void
338 vnet_init_done(void *unused)
339 {
340
341 curvnet = NULL;
342 }
343
344 SYSINIT(vnet_init_done, SI_SUB_VNET_DONE, SI_ORDER_FIRST, vnet_init_done,
345 NULL);
346
347 /*
348 * Once on boot, initialize the modspace freelist to entirely cover modspace.
349 */
350 static void
351 vnet_data_startup(void *dummy __unused)
352 {
353 struct vnet_data_free *df;
354
355 df = malloc(sizeof(*df), M_VNET_DATA_FREE, M_WAITOK | M_ZERO);
356 df->vnd_start = (uintptr_t)&VNET_NAME(modspace);
357 df->vnd_len = VNET_MODMIN;
358 TAILQ_INSERT_HEAD(&vnet_data_free_head, df, vnd_link);
359 sx_init(&vnet_data_free_lock, "vnet_data alloc lock");
360 }
361 SYSINIT(vnet_data, SI_SUB_KLD, SI_ORDER_FIRST, vnet_data_startup, 0);
362
363 /*
364 * When a module is loaded and requires storage for a virtualized global
365 * variable, allocate space from the modspace free list. This interface
366 * should be used only by the kernel linker.
367 */
368 void *
369 vnet_data_alloc(int size)
370 {
371 struct vnet_data_free *df;
372 void *s;
373
374 s = NULL;
375 size = roundup2(size, sizeof(void *));
376 sx_xlock(&vnet_data_free_lock);
377 TAILQ_FOREACH(df, &vnet_data_free_head, vnd_link) {
378 if (df->vnd_len < size)
379 continue;
380 if (df->vnd_len == size) {
381 s = (void *)df->vnd_start;
382 TAILQ_REMOVE(&vnet_data_free_head, df, vnd_link);
383 free(df, M_VNET_DATA_FREE);
384 break;
385 }
386 s = (void *)df->vnd_start;
387 df->vnd_len -= size;
388 df->vnd_start = df->vnd_start + size;
389 break;
390 }
391 sx_xunlock(&vnet_data_free_lock);
392
393 return (s);
394 }
395
396 /*
397 * Free space for a virtualized global variable on module unload.
398 */
399 void
400 vnet_data_free(void *start_arg, int size)
401 {
402 struct vnet_data_free *df;
403 struct vnet_data_free *dn;
404 uintptr_t start;
405 uintptr_t end;
406
407 size = roundup2(size, sizeof(void *));
408 start = (uintptr_t)start_arg;
409 end = start + size;
410 /*
411 * Free a region of space and merge it with as many neighbors as
412 * possible. Keeping the list sorted simplifies this operation.
413 */
414 sx_xlock(&vnet_data_free_lock);
415 TAILQ_FOREACH(df, &vnet_data_free_head, vnd_link) {
416 if (df->vnd_start > end)
417 break;
418 /*
419 * If we expand at the end of an entry we may have to merge
420 * it with the one following it as well.
421 */
422 if (df->vnd_start + df->vnd_len == start) {
423 df->vnd_len += size;
424 dn = TAILQ_NEXT(df, vnd_link);
425 if (df->vnd_start + df->vnd_len == dn->vnd_start) {
426 df->vnd_len += dn->vnd_len;
427 TAILQ_REMOVE(&vnet_data_free_head, dn,
428 vnd_link);
429 free(dn, M_VNET_DATA_FREE);
430 }
431 sx_xunlock(&vnet_data_free_lock);
432 return;
433 }
434 if (df->vnd_start == end) {
435 df->vnd_start = start;
436 df->vnd_len += size;
437 sx_xunlock(&vnet_data_free_lock);
438 return;
439 }
440 }
441 dn = malloc(sizeof(*df), M_VNET_DATA_FREE, M_WAITOK | M_ZERO);
442 dn->vnd_start = start;
443 dn->vnd_len = size;
444 if (df)
445 TAILQ_INSERT_BEFORE(df, dn, vnd_link);
446 else
447 TAILQ_INSERT_TAIL(&vnet_data_free_head, dn, vnd_link);
448 sx_xunlock(&vnet_data_free_lock);
449 }
450
451 /*
452 * When a new virtualized global variable has been allocated, propagate its
453 * initial value to each already-allocated virtual network stack instance.
454 */
455 void
456 vnet_data_copy(void *start, int size)
457 {
458 struct vnet *vnet;
459
460 VNET_LIST_RLOCK();
461 LIST_FOREACH(vnet, &vnet_head, vnet_le)
462 memcpy((void *)((uintptr_t)vnet->vnet_data_base +
463 (uintptr_t)start), start, size);
464 VNET_LIST_RUNLOCK();
465 }
466
467 /*
468 * Support for special SYSINIT handlers registered via VNET_SYSINIT()
469 * and VNET_SYSUNINIT().
470 */
471 void
472 vnet_register_sysinit(void *arg)
473 {
474 struct vnet_sysinit *vs, *vs2;
475 struct vnet *vnet;
476
477 vs = arg;
478 KASSERT(vs->subsystem > SI_SUB_VNET, ("vnet sysinit too early"));
479
480 /* Add the constructor to the global list of vnet constructors. */
481 VNET_SYSINIT_WLOCK();
482 TAILQ_FOREACH(vs2, &vnet_constructors, link) {
483 if (vs2->subsystem > vs->subsystem)
484 break;
485 if (vs2->subsystem == vs->subsystem && vs2->order > vs->order)
486 break;
487 }
488 if (vs2 != NULL)
489 TAILQ_INSERT_BEFORE(vs2, vs, link);
490 else
491 TAILQ_INSERT_TAIL(&vnet_constructors, vs, link);
492
493 /*
494 * Invoke the constructor on all the existing vnets when it is
495 * registered.
496 */
497 VNET_FOREACH(vnet) {
498 CURVNET_SET_QUIET(vnet);
499 vs->func(vs->arg);
500 CURVNET_RESTORE();
501 }
502 VNET_SYSINIT_WUNLOCK();
503 }
504
505 void
506 vnet_deregister_sysinit(void *arg)
507 {
508 struct vnet_sysinit *vs;
509
510 vs = arg;
511
512 /* Remove the constructor from the global list of vnet constructors. */
513 VNET_SYSINIT_WLOCK();
514 TAILQ_REMOVE(&vnet_constructors, vs, link);
515 VNET_SYSINIT_WUNLOCK();
516 }
517
518 void
519 vnet_register_sysuninit(void *arg)
520 {
521 struct vnet_sysinit *vs, *vs2;
522
523 vs = arg;
524
525 /* Add the destructor to the global list of vnet destructors. */
526 VNET_SYSINIT_WLOCK();
527 TAILQ_FOREACH(vs2, &vnet_destructors, link) {
528 if (vs2->subsystem > vs->subsystem)
529 break;
530 if (vs2->subsystem == vs->subsystem && vs2->order > vs->order)
531 break;
532 }
533 if (vs2 != NULL)
534 TAILQ_INSERT_BEFORE(vs2, vs, link);
535 else
536 TAILQ_INSERT_TAIL(&vnet_destructors, vs, link);
537 VNET_SYSINIT_WUNLOCK();
538 }
539
540 void
541 vnet_deregister_sysuninit(void *arg)
542 {
543 struct vnet_sysinit *vs;
544 struct vnet *vnet;
545
546 vs = arg;
547
548 /*
549 * Invoke the destructor on all the existing vnets when it is
550 * deregistered.
551 */
552 VNET_SYSINIT_WLOCK();
553 VNET_FOREACH(vnet) {
554 CURVNET_SET_QUIET(vnet);
555 vs->func(vs->arg);
556 CURVNET_RESTORE();
557 }
558
559 /* Remove the destructor from the global list of vnet destructors. */
560 TAILQ_REMOVE(&vnet_destructors, vs, link);
561 VNET_SYSINIT_WUNLOCK();
562 }
563
564 /*
565 * Invoke all registered vnet constructors on the current vnet. Used during
566 * vnet construction. The caller is responsible for ensuring the new vnet is
567 * the current vnet and that the vnet_sysinit_sxlock lock is locked.
568 */
569 void
570 vnet_sysinit(void)
571 {
572 struct vnet_sysinit *vs;
573
574 VNET_SYSINIT_RLOCK();
575 TAILQ_FOREACH(vs, &vnet_constructors, link) {
576 vs->func(vs->arg);
577 }
578 VNET_SYSINIT_RUNLOCK();
579 }
580
581 /*
582 * Invoke all registered vnet destructors on the current vnet. Used during
583 * vnet destruction. The caller is responsible for ensuring the dying vnet
584 * the current vnet and that the vnet_sysinit_sxlock lock is locked.
585 */
586 void
587 vnet_sysuninit(void)
588 {
589 struct vnet_sysinit *vs;
590
591 VNET_SYSINIT_RLOCK();
592 TAILQ_FOREACH_REVERSE(vs, &vnet_destructors, vnet_sysuninit_head,
593 link) {
594 vs->func(vs->arg);
595 }
596 VNET_SYSINIT_RUNLOCK();
597 }
598
599 /*
600 * EVENTHANDLER(9) extensions.
601 */
602 /*
603 * Invoke the eventhandler function originally registered with the possibly
604 * registered argument for all virtual network stack instances.
605 *
606 * This iterator can only be used for eventhandlers that do not take any
607 * additional arguments, as we do ignore the variadic arguments from the
608 * EVENTHANDLER_INVOKE() call.
609 */
610 void
611 vnet_global_eventhandler_iterator_func(void *arg, ...)
612 {
613 VNET_ITERATOR_DECL(vnet_iter);
614 struct eventhandler_entry_vimage *v_ee;
615
616 /*
617 * There is a bug here in that we should actually cast things to
618 * (struct eventhandler_entry_ ## name *) but that's not easily
619 * possible in here so just re-using the variadic version we
620 * defined for the generic vimage case.
621 */
622 v_ee = arg;
623 VNET_LIST_RLOCK();
624 VNET_FOREACH(vnet_iter) {
625 CURVNET_SET(vnet_iter);
626 ((vimage_iterator_func_t)v_ee->func)(v_ee->ee_arg);
627 CURVNET_RESTORE();
628 }
629 VNET_LIST_RUNLOCK();
630 }
631
632 #ifdef VNET_DEBUG
633 struct vnet_recursion {
634 SLIST_ENTRY(vnet_recursion) vnr_le;
635 const char *prev_fn;
636 const char *where_fn;
637 int where_line;
638 struct vnet *old_vnet;
639 struct vnet *new_vnet;
640 };
641
642 static SLIST_HEAD(, vnet_recursion) vnet_recursions =
643 SLIST_HEAD_INITIALIZER(vnet_recursions);
644
645 static void
646 vnet_print_recursion(struct vnet_recursion *vnr, int brief)
647 {
648
649 if (!brief)
650 printf("CURVNET_SET() recursion in ");
651 printf("%s() line %d, prev in %s()", vnr->where_fn, vnr->where_line,
652 vnr->prev_fn);
653 if (brief)
654 printf(", ");
655 else
656 printf("\n ");
657 printf("%p -> %p\n", vnr->old_vnet, vnr->new_vnet);
658 }
659
660 void
661 vnet_log_recursion(struct vnet *old_vnet, const char *old_fn, int line)
662 {
663 struct vnet_recursion *vnr;
664
665 /* Skip already logged recursion events. */
666 SLIST_FOREACH(vnr, &vnet_recursions, vnr_le)
667 if (vnr->prev_fn == old_fn &&
668 vnr->where_fn == curthread->td_vnet_lpush &&
669 vnr->where_line == line &&
670 (vnr->old_vnet == vnr->new_vnet) == (curvnet == old_vnet))
671 return;
672
673 vnr = malloc(sizeof(*vnr), M_VNET, M_NOWAIT | M_ZERO);
674 if (vnr == NULL)
675 panic("%s: malloc failed", __func__);
676 vnr->prev_fn = old_fn;
677 vnr->where_fn = curthread->td_vnet_lpush;
678 vnr->where_line = line;
679 vnr->old_vnet = old_vnet;
680 vnr->new_vnet = curvnet;
681
682 SLIST_INSERT_HEAD(&vnet_recursions, vnr, vnr_le);
683
684 vnet_print_recursion(vnr, 0);
685 #ifdef KDB
686 kdb_backtrace();
687 #endif
688 }
689 #endif /* VNET_DEBUG */
690
691 /*
692 * DDB(4).
693 */
694 #ifdef DDB
695 DB_SHOW_COMMAND(vnets, db_show_vnets)
696 {
697 VNET_ITERATOR_DECL(vnet_iter);
698
699 VNET_FOREACH(vnet_iter) {
700 db_printf("vnet = %p\n", vnet_iter);
701 db_printf(" vnet_magic_n = 0x%x (%s, orig 0x%x)\n",
702 vnet_iter->vnet_magic_n,
703 (vnet_iter->vnet_magic_n == VNET_MAGIC_N) ?
704 "ok" : "mismatch", VNET_MAGIC_N);
705 db_printf(" vnet_ifcnt = %u\n", vnet_iter->vnet_ifcnt);
706 db_printf(" vnet_sockcnt = %u\n", vnet_iter->vnet_sockcnt);
707 db_printf(" vnet_data_mem = %p\n", vnet_iter->vnet_data_mem);
708 db_printf(" vnet_data_base = 0x%jx\n",
709 (uintmax_t)vnet_iter->vnet_data_base);
710 db_printf("\n");
711 if (db_pager_quit)
712 break;
713 }
714 }
715
716 static void
717 db_show_vnet_print_vs(struct vnet_sysinit *vs, int ddb)
718 {
719 const char *vsname, *funcname;
720 c_db_sym_t sym;
721 db_expr_t offset;
722
723 #define xprint(...) \
724 if (ddb) \
725 db_printf(__VA_ARGS__); \
726 else \
727 printf(__VA_ARGS__)
728
729 if (vs == NULL) {
730 xprint("%s: no vnet_sysinit * given\n", __func__);
731 return;
732 }
733
734 sym = db_search_symbol((vm_offset_t)vs, DB_STGY_ANY, &offset);
735 db_symbol_values(sym, &vsname, NULL);
736 sym = db_search_symbol((vm_offset_t)vs->func, DB_STGY_PROC, &offset);
737 db_symbol_values(sym, &funcname, NULL);
738 xprint("%s(%p)\n", (vsname != NULL) ? vsname : "", vs);
739 xprint(" 0x%08x 0x%08x\n", vs->subsystem, vs->order);
740 xprint(" %p(%s)(%p)\n",
741 vs->func, (funcname != NULL) ? funcname : "", vs->arg);
742 #undef xprint
743 }
744
745 DB_SHOW_COMMAND(vnet_sysinit, db_show_vnet_sysinit)
746 {
747 struct vnet_sysinit *vs;
748
749 db_printf("VNET_SYSINIT vs Name(Ptr)\n");
750 db_printf(" Subsystem Order\n");
751 db_printf(" Function(Name)(Arg)\n");
752 TAILQ_FOREACH(vs, &vnet_constructors, link) {
753 db_show_vnet_print_vs(vs, 1);
754 if (db_pager_quit)
755 break;
756 }
757 }
758
759 DB_SHOW_COMMAND(vnet_sysuninit, db_show_vnet_sysuninit)
760 {
761 struct vnet_sysinit *vs;
762
763 db_printf("VNET_SYSUNINIT vs Name(Ptr)\n");
764 db_printf(" Subsystem Order\n");
765 db_printf(" Function(Name)(Arg)\n");
766 TAILQ_FOREACH_REVERSE(vs, &vnet_destructors, vnet_sysuninit_head,
767 link) {
768 db_show_vnet_print_vs(vs, 1);
769 if (db_pager_quit)
770 break;
771 }
772 }
773
774 #ifdef VNET_DEBUG
775 DB_SHOW_COMMAND(vnetrcrs, db_show_vnetrcrs)
776 {
777 struct vnet_recursion *vnr;
778
779 SLIST_FOREACH(vnr, &vnet_recursions, vnr_le)
780 vnet_print_recursion(vnr, 1);
781 }
782 #endif
783 #endif /* DDB */
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