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("$FreeBSD$");
38
39 #include "opt_ddb.h"
40 #include "opt_kdb.h"
41
42 #include <sys/param.h>
43 #include <sys/kdb.h>
44 #include <sys/kernel.h>
45 #include <sys/jail.h>
46 #include <sys/sdt.h>
47 #include <sys/systm.h>
48 #include <sys/sysctl.h>
49 #include <sys/eventhandler.h>
50 #include <sys/lock.h>
51 #include <sys/malloc.h>
52 #include <sys/proc.h>
53 #include <sys/socket.h>
54 #include <sys/sx.h>
55 #include <sys/sysctl.h>
56
57 #include <machine/stdarg.h>
58
59 #ifdef DDB
60 #include <ddb/ddb.h>
61 #include <ddb/db_sym.h>
62 #endif
63
64 #include <net/if.h>
65 #include <net/if_var.h>
66 #include <net/vnet.h>
67
68 /*-
69 * This file implements core functions for virtual network stacks:
70 *
71 * - Virtual network stack management functions.
72 *
73 * - Virtual network stack memory allocator, which virtualizes global
74 * variables in the network stack
75 *
76 * - Virtualized SYSINIT's/SYSUNINIT's, which allow network stack subsystems
77 * to register startup/shutdown events to be run for each virtual network
78 * stack instance.
79 */
80
81 FEATURE(vimage, "VIMAGE kernel virtualization");
82
83 static MALLOC_DEFINE(M_VNET, "vnet", "network stack control block");
84
85 /*
86 * The virtual network stack list has two read-write locks, one sleepable and
87 * the other not, so that the list can be stablized and walked in a variety
88 * of network stack contexts. Both must be acquired exclusively to modify
89 * the list, but a read lock of either lock is sufficient to walk the list.
90 */
91 struct rwlock vnet_rwlock;
92 struct sx vnet_sxlock;
93
94 #define VNET_LIST_WLOCK() do { \
95 sx_xlock(&vnet_sxlock); \
96 rw_wlock(&vnet_rwlock); \
97 } while (0)
98
99 #define VNET_LIST_WUNLOCK() do { \
100 rw_wunlock(&vnet_rwlock); \
101 sx_xunlock(&vnet_sxlock); \
102 } while (0)
103
104 struct vnet_list_head vnet_head;
105 struct vnet *vnet0;
106
107 /*
108 * The virtual network stack allocator provides storage for virtualized
109 * global variables. These variables are defined/declared using the
110 * VNET_DEFINE()/VNET_DECLARE() macros, which place them in the 'set_vnet'
111 * linker set. The details of the implementation are somewhat subtle, but
112 * allow the majority of most network subsystems to maintain
113 * virtualization-agnostic.
114 *
115 * The virtual network stack allocator handles variables in the base kernel
116 * vs. modules in similar but different ways. In both cases, virtualized
117 * global variables are marked as such by being declared to be part of the
118 * vnet linker set. These "master" copies of global variables serve two
119 * functions:
120 *
121 * (1) They contain static initialization or "default" values for global
122 * variables which will be propagated to each virtual network stack
123 * instance when created. As with normal global variables, they default
124 * to zero-filled.
125 *
126 * (2) They act as unique global names by which the variable can be referred
127 * to, regardless of network stack instance. The single global symbol
128 * will be used to calculate the location of a per-virtual instance
129 * variable at run-time.
130 *
131 * Each virtual network stack instance has a complete copy of each
132 * virtualized global variable, stored in a malloc'd block of memory
133 * referred to by vnet->vnet_data_mem. Critical to the design is that each
134 * per-instance memory block is laid out identically to the master block so
135 * that the offset of each global variable is the same across all blocks. To
136 * optimize run-time access, a precalculated 'base' address,
137 * vnet->vnet_data_base, is stored in each vnet, and is the amount that can
138 * be added to the address of a 'master' instance of a variable to get to the
139 * per-vnet instance.
140 *
141 * Virtualized global variables are handled in a similar manner, but as each
142 * module has its own 'set_vnet' linker set, and we want to keep all
143 * virtualized globals togther, we reserve space in the kernel's linker set
144 * for potential module variables using a per-vnet character array,
145 * 'modspace'. The virtual network stack allocator maintains a free list to
146 * track what space in the array is free (all, initially) and as modules are
147 * linked, allocates portions of the space to specific globals. The kernel
148 * module linker queries the virtual network stack allocator and will
149 * bind references of the global to the location during linking. It also
150 * calls into the virtual network stack allocator, once the memory is
151 * initialized, in order to propagate the new static initializations to all
152 * existing virtual network stack instances so that the soon-to-be executing
153 * module will find every network stack instance with proper default values.
154 */
155
156 /*
157 * Number of bytes of data in the 'set_vnet' linker set, and hence the total
158 * size of all kernel virtualized global variables, and the malloc(9) type
159 * that will be used to allocate it.
160 */
161 #define VNET_BYTES (VNET_STOP - VNET_START)
162
163 static MALLOC_DEFINE(M_VNET_DATA, "vnet_data", "VNET data");
164
165 /*
166 * VNET_MODMIN is the minimum number of bytes we will reserve for the sum of
167 * global variables across all loaded modules. As this actually sizes an
168 * array declared as a virtualized global variable in the kernel itself, and
169 * we want the virtualized global variable space to be page-sized, we may
170 * have more space than that in practice.
171 */
172 #define VNET_MODMIN (8 * PAGE_SIZE)
173 #define VNET_SIZE roundup2(VNET_BYTES, PAGE_SIZE)
174
175 /*
176 * Space to store virtualized global variables from loadable kernel modules,
177 * and the free list to manage it.
178 */
179 static VNET_DEFINE(char, modspace[VNET_MODMIN]);
180
181 /*
182 * Global lists of subsystem constructor and destructors for vnets. They are
183 * registered via VNET_SYSINIT() and VNET_SYSUNINIT(). Both lists are
184 * protected by the vnet_sysinit_sxlock global lock.
185 */
186 static TAILQ_HEAD(vnet_sysinit_head, vnet_sysinit) vnet_constructors =
187 TAILQ_HEAD_INITIALIZER(vnet_constructors);
188 static TAILQ_HEAD(vnet_sysuninit_head, vnet_sysinit) vnet_destructors =
189 TAILQ_HEAD_INITIALIZER(vnet_destructors);
190
191 struct sx vnet_sysinit_sxlock;
192
193 #define VNET_SYSINIT_WLOCK() sx_xlock(&vnet_sysinit_sxlock);
194 #define VNET_SYSINIT_WUNLOCK() sx_xunlock(&vnet_sysinit_sxlock);
195 #define VNET_SYSINIT_RLOCK() sx_slock(&vnet_sysinit_sxlock);
196 #define VNET_SYSINIT_RUNLOCK() sx_sunlock(&vnet_sysinit_sxlock);
197
198 struct vnet_data_free {
199 uintptr_t vnd_start;
200 int vnd_len;
201 TAILQ_ENTRY(vnet_data_free) vnd_link;
202 };
203
204 static MALLOC_DEFINE(M_VNET_DATA_FREE, "vnet_data_free",
205 "VNET resource accounting");
206 static TAILQ_HEAD(, vnet_data_free) vnet_data_free_head =
207 TAILQ_HEAD_INITIALIZER(vnet_data_free_head);
208 static struct sx vnet_data_free_lock;
209
210 SDT_PROVIDER_DEFINE(vnet);
211 SDT_PROBE_DEFINE1(vnet, functions, vnet_alloc, entry, "int");
212 SDT_PROBE_DEFINE2(vnet, functions, vnet_alloc, alloc, "int",
213 "struct vnet *");
214 SDT_PROBE_DEFINE2(vnet, functions, vnet_alloc, return,
215 "int", "struct vnet *");
216 SDT_PROBE_DEFINE2(vnet, functions, vnet_destroy, entry,
217 "int", "struct vnet *");
218 SDT_PROBE_DEFINE1(vnet, functions, vnet_destroy, return,
219 "int");
220
221 #ifdef DDB
222 static void db_show_vnet_print_vs(struct vnet_sysinit *, int);
223 #endif
224
225 /*
226 * Allocate a virtual network stack.
227 */
228 struct vnet *
229 vnet_alloc(void)
230 {
231 struct vnet *vnet;
232
233 SDT_PROBE1(vnet, functions, vnet_alloc, entry, __LINE__);
234 vnet = malloc(sizeof(struct vnet), M_VNET, M_WAITOK | M_ZERO);
235 vnet->vnet_magic_n = VNET_MAGIC_N;
236 vnet->vnet_state = 0;
237 SDT_PROBE2(vnet, functions, vnet_alloc, alloc, __LINE__, vnet);
238
239 /*
240 * Allocate storage for virtualized global variables and copy in
241 * initial values form our 'master' copy.
242 */
243 vnet->vnet_data_mem = malloc(VNET_SIZE, M_VNET_DATA, M_WAITOK);
244 memcpy(vnet->vnet_data_mem, (void *)VNET_START, VNET_BYTES);
245
246 /*
247 * All use of vnet-specific data will immediately subtract VNET_START
248 * from the base memory pointer, so pre-calculate that now to avoid
249 * it on each use.
250 */
251 vnet->vnet_data_base = (uintptr_t)vnet->vnet_data_mem - VNET_START;
252
253 /* Initialize / attach vnet module instances. */
254 CURVNET_SET_QUIET(vnet);
255 vnet_sysinit();
256 CURVNET_RESTORE();
257
258 VNET_LIST_WLOCK();
259 LIST_INSERT_HEAD(&vnet_head, vnet, vnet_le);
260 VNET_LIST_WUNLOCK();
261
262 SDT_PROBE2(vnet, functions, vnet_alloc, return, __LINE__, vnet);
263 return (vnet);
264 }
265
266 /*
267 * Destroy a virtual network stack.
268 */
269 void
270 vnet_destroy(struct vnet *vnet)
271 {
272
273 SDT_PROBE2(vnet, functions, vnet_destroy, entry, __LINE__, vnet);
274 KASSERT(vnet->vnet_sockcnt == 0,
275 ("%s: vnet still has sockets", __func__));
276
277 VNET_LIST_WLOCK();
278 LIST_REMOVE(vnet, vnet_le);
279 VNET_LIST_WUNLOCK();
280
281 CURVNET_SET_QUIET(vnet);
282 vnet_sysuninit();
283 CURVNET_RESTORE();
284
285 /*
286 * Release storage for the virtual network stack instance.
287 */
288 free(vnet->vnet_data_mem, M_VNET_DATA);
289 vnet->vnet_data_mem = NULL;
290 vnet->vnet_data_base = 0;
291 vnet->vnet_magic_n = 0xdeadbeef;
292 free(vnet, M_VNET);
293 SDT_PROBE1(vnet, functions, vnet_destroy, return, __LINE__);
294 }
295
296 /*
297 * Boot time initialization and allocation of virtual network stacks.
298 */
299 static void
300 vnet_init_prelink(void *arg __unused)
301 {
302
303 rw_init(&vnet_rwlock, "vnet_rwlock");
304 sx_init(&vnet_sxlock, "vnet_sxlock");
305 sx_init(&vnet_sysinit_sxlock, "vnet_sysinit_sxlock");
306 LIST_INIT(&vnet_head);
307 }
308 SYSINIT(vnet_init_prelink, SI_SUB_VNET_PRELINK, SI_ORDER_FIRST,
309 vnet_init_prelink, NULL);
310
311 static void
312 vnet0_init(void *arg __unused)
313 {
314
315 /* Warn people before take off - in case we crash early. */
316 printf("WARNING: VIMAGE (virtualized network stack) is a highly "
317 "experimental feature.\n");
318
319 /*
320 * We MUST clear curvnet in vi_init_done() before going SMP,
321 * otherwise CURVNET_SET() macros would scream about unnecessary
322 * curvnet recursions.
323 */
324 curvnet = prison0.pr_vnet = vnet0 = vnet_alloc();
325 }
326 SYSINIT(vnet0_init, SI_SUB_VNET, SI_ORDER_FIRST, vnet0_init, NULL);
327
328 static void
329 vnet_init_done(void *unused __unused)
330 {
331
332 curvnet = NULL;
333 }
334 SYSINIT(vnet_init_done, SI_SUB_VNET_DONE, SI_ORDER_ANY, vnet_init_done,
335 NULL);
336
337 /*
338 * Once on boot, initialize the modspace freelist to entirely cover modspace.
339 */
340 static void
341 vnet_data_startup(void *dummy __unused)
342 {
343 struct vnet_data_free *df;
344
345 df = malloc(sizeof(*df), M_VNET_DATA_FREE, M_WAITOK | M_ZERO);
346 df->vnd_start = (uintptr_t)&VNET_NAME(modspace);
347 df->vnd_len = VNET_MODMIN;
348 TAILQ_INSERT_HEAD(&vnet_data_free_head, df, vnd_link);
349 sx_init(&vnet_data_free_lock, "vnet_data alloc lock");
350 }
351 SYSINIT(vnet_data, SI_SUB_KLD, SI_ORDER_FIRST, vnet_data_startup, NULL);
352
353 /* Dummy VNET_SYSINIT to make sure we always reach the final end state. */
354 static void
355 vnet_sysinit_done(void *unused __unused)
356 {
357
358 return;
359 }
360 VNET_SYSINIT(vnet_sysinit_done, SI_SUB_VNET_DONE, SI_ORDER_ANY,
361 vnet_sysinit_done, NULL);
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 curvnet->vnet_state = vs->subsystem;
577 vs->func(vs->arg);
578 }
579 VNET_SYSINIT_RUNLOCK();
580 }
581
582 /*
583 * Invoke all registered vnet destructors on the current vnet. Used during
584 * vnet destruction. The caller is responsible for ensuring the dying vnet
585 * the current vnet and that the vnet_sysinit_sxlock lock is locked.
586 */
587 void
588 vnet_sysuninit(void)
589 {
590 struct vnet_sysinit *vs;
591
592 VNET_SYSINIT_RLOCK();
593 TAILQ_FOREACH_REVERSE(vs, &vnet_destructors, vnet_sysuninit_head,
594 link) {
595 curvnet->vnet_state = vs->subsystem;
596 vs->func(vs->arg);
597 }
598 VNET_SYSINIT_RUNLOCK();
599 }
600
601 /*
602 * EVENTHANDLER(9) extensions.
603 */
604 /*
605 * Invoke the eventhandler function originally registered with the possibly
606 * registered argument for all virtual network stack instances.
607 *
608 * This iterator can only be used for eventhandlers that do not take any
609 * additional arguments, as we do ignore the variadic arguments from the
610 * EVENTHANDLER_INVOKE() call.
611 */
612 void
613 vnet_global_eventhandler_iterator_func(void *arg, ...)
614 {
615 VNET_ITERATOR_DECL(vnet_iter);
616 struct eventhandler_entry_vimage *v_ee;
617
618 /*
619 * There is a bug here in that we should actually cast things to
620 * (struct eventhandler_entry_ ## name *) but that's not easily
621 * possible in here so just re-using the variadic version we
622 * defined for the generic vimage case.
623 */
624 v_ee = arg;
625 VNET_LIST_RLOCK();
626 VNET_FOREACH(vnet_iter) {
627 CURVNET_SET(vnet_iter);
628 ((vimage_iterator_func_t)v_ee->func)(v_ee->ee_arg);
629 CURVNET_RESTORE();
630 }
631 VNET_LIST_RUNLOCK();
632 }
633
634 #ifdef VNET_DEBUG
635 struct vnet_recursion {
636 SLIST_ENTRY(vnet_recursion) vnr_le;
637 const char *prev_fn;
638 const char *where_fn;
639 int where_line;
640 struct vnet *old_vnet;
641 struct vnet *new_vnet;
642 };
643
644 static SLIST_HEAD(, vnet_recursion) vnet_recursions =
645 SLIST_HEAD_INITIALIZER(vnet_recursions);
646
647 static void
648 vnet_print_recursion(struct vnet_recursion *vnr, int brief)
649 {
650
651 if (!brief)
652 printf("CURVNET_SET() recursion in ");
653 printf("%s() line %d, prev in %s()", vnr->where_fn, vnr->where_line,
654 vnr->prev_fn);
655 if (brief)
656 printf(", ");
657 else
658 printf("\n ");
659 printf("%p -> %p\n", vnr->old_vnet, vnr->new_vnet);
660 }
661
662 void
663 vnet_log_recursion(struct vnet *old_vnet, const char *old_fn, int line)
664 {
665 struct vnet_recursion *vnr;
666
667 /* Skip already logged recursion events. */
668 SLIST_FOREACH(vnr, &vnet_recursions, vnr_le)
669 if (vnr->prev_fn == old_fn &&
670 vnr->where_fn == curthread->td_vnet_lpush &&
671 vnr->where_line == line &&
672 (vnr->old_vnet == vnr->new_vnet) == (curvnet == old_vnet))
673 return;
674
675 vnr = malloc(sizeof(*vnr), M_VNET, M_NOWAIT | M_ZERO);
676 if (vnr == NULL)
677 panic("%s: malloc failed", __func__);
678 vnr->prev_fn = old_fn;
679 vnr->where_fn = curthread->td_vnet_lpush;
680 vnr->where_line = line;
681 vnr->old_vnet = old_vnet;
682 vnr->new_vnet = curvnet;
683
684 SLIST_INSERT_HEAD(&vnet_recursions, vnr, vnr_le);
685
686 vnet_print_recursion(vnr, 0);
687 #ifdef KDB
688 kdb_backtrace();
689 #endif
690 }
691 #endif /* VNET_DEBUG */
692
693 /*
694 * DDB(4).
695 */
696 #ifdef DDB
697 static void
698 db_vnet_print(struct vnet *vnet)
699 {
700
701 db_printf("vnet = %p\n", vnet);
702 db_printf(" vnet_magic_n = %#08x (%s, orig %#08x)\n",
703 vnet->vnet_magic_n,
704 (vnet->vnet_magic_n == VNET_MAGIC_N) ?
705 "ok" : "mismatch", VNET_MAGIC_N);
706 db_printf(" vnet_ifcnt = %u\n", vnet->vnet_ifcnt);
707 db_printf(" vnet_sockcnt = %u\n", vnet->vnet_sockcnt);
708 db_printf(" vnet_data_mem = %p\n", vnet->vnet_data_mem);
709 db_printf(" vnet_data_base = %#jx\n",
710 (uintmax_t)vnet->vnet_data_base);
711 db_printf(" vnet_state = %#08x\n", vnet->vnet_state);
712 db_printf("\n");
713 }
714
715 DB_SHOW_ALL_COMMAND(vnets, db_show_all_vnets)
716 {
717 VNET_ITERATOR_DECL(vnet_iter);
718
719 VNET_FOREACH(vnet_iter) {
720 db_vnet_print(vnet_iter);
721 if (db_pager_quit)
722 break;
723 }
724 }
725
726 DB_SHOW_COMMAND(vnet, db_show_vnet)
727 {
728
729 if (!have_addr) {
730 db_printf("usage: show vnet <struct vnet *>\n");
731 return;
732 }
733
734 db_vnet_print((struct vnet *)addr);
735 }
736
737 static void
738 db_show_vnet_print_vs(struct vnet_sysinit *vs, int ddb)
739 {
740 const char *vsname, *funcname;
741 c_db_sym_t sym;
742 db_expr_t offset;
743
744 #define xprint(...) \
745 if (ddb) \
746 db_printf(__VA_ARGS__); \
747 else \
748 printf(__VA_ARGS__)
749
750 if (vs == NULL) {
751 xprint("%s: no vnet_sysinit * given\n", __func__);
752 return;
753 }
754
755 sym = db_search_symbol((vm_offset_t)vs, DB_STGY_ANY, &offset);
756 db_symbol_values(sym, &vsname, NULL);
757 sym = db_search_symbol((vm_offset_t)vs->func, DB_STGY_PROC, &offset);
758 db_symbol_values(sym, &funcname, NULL);
759 xprint("%s(%p)\n", (vsname != NULL) ? vsname : "", vs);
760 xprint(" %#08x %#08x\n", vs->subsystem, vs->order);
761 xprint(" %p(%s)(%p)\n",
762 vs->func, (funcname != NULL) ? funcname : "", vs->arg);
763 #undef xprint
764 }
765
766 DB_SHOW_COMMAND(vnet_sysinit, db_show_vnet_sysinit)
767 {
768 struct vnet_sysinit *vs;
769
770 db_printf("VNET_SYSINIT vs Name(Ptr)\n");
771 db_printf(" Subsystem Order\n");
772 db_printf(" Function(Name)(Arg)\n");
773 TAILQ_FOREACH(vs, &vnet_constructors, link) {
774 db_show_vnet_print_vs(vs, 1);
775 if (db_pager_quit)
776 break;
777 }
778 }
779
780 DB_SHOW_COMMAND(vnet_sysuninit, db_show_vnet_sysuninit)
781 {
782 struct vnet_sysinit *vs;
783
784 db_printf("VNET_SYSUNINIT vs Name(Ptr)\n");
785 db_printf(" Subsystem Order\n");
786 db_printf(" Function(Name)(Arg)\n");
787 TAILQ_FOREACH_REVERSE(vs, &vnet_destructors, vnet_sysuninit_head,
788 link) {
789 db_show_vnet_print_vs(vs, 1);
790 if (db_pager_quit)
791 break;
792 }
793 }
794
795 #ifdef VNET_DEBUG
796 DB_SHOW_COMMAND(vnetrcrs, db_show_vnetrcrs)
797 {
798 struct vnet_recursion *vnr;
799
800 SLIST_FOREACH(vnr, &vnet_recursions, vnr_le)
801 vnet_print_recursion(vnr, 1);
802 }
803 #endif
804 #endif /* DDB */
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