1 | /* $NetBSD: subr_evcnt.c,v 1.12 2014/02/25 18:30:11 pooka Exp $ */ |
2 | |
3 | /* |
4 | * Copyright (c) 1996, 2000 Christopher G. Demetriou |
5 | * All rights reserved. |
6 | * |
7 | * Redistribution and use in source and binary forms, with or without |
8 | * modification, are permitted provided that the following conditions |
9 | * are met: |
10 | * 1. Redistributions of source code must retain the above copyright |
11 | * notice, this list of conditions and the following disclaimer. |
12 | * 2. Redistributions in binary form must reproduce the above copyright |
13 | * notice, this list of conditions and the following disclaimer in the |
14 | * documentation and/or other materials provided with the distribution. |
15 | * 3. All advertising materials mentioning features or use of this software |
16 | * must display the following acknowledgement: |
17 | * This product includes software developed for the |
18 | * NetBSD Project. See http://www.NetBSD.org/ for |
19 | * information about NetBSD. |
20 | * 4. The name of the author may not be used to endorse or promote products |
21 | * derived from this software without specific prior written permission. |
22 | * |
23 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
24 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
25 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
26 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
27 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
28 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
29 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
30 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
31 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
32 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
33 | * |
34 | * --(license Id: LICENSE.proto,v 1.1 2000/06/13 21:40:26 cgd Exp )-- |
35 | */ |
36 | |
37 | /* |
38 | * Copyright (c) 1992, 1993 |
39 | * The Regents of the University of California. All rights reserved. |
40 | * |
41 | * This software was developed by the Computer Systems Engineering group |
42 | * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and |
43 | * contributed to Berkeley. |
44 | * |
45 | * All advertising materials mentioning features or use of this software |
46 | * must display the following acknowledgement: |
47 | * This product includes software developed by the University of |
48 | * California, Lawrence Berkeley Laboratories. |
49 | * |
50 | * Redistribution and use in source and binary forms, with or without |
51 | * modification, are permitted provided that the following conditions |
52 | * are met: |
53 | * 1. Redistributions of source code must retain the above copyright |
54 | * notice, this list of conditions and the following disclaimer. |
55 | * 2. Redistributions in binary form must reproduce the above copyright |
56 | * notice, this list of conditions and the following disclaimer in the |
57 | * documentation and/or other materials provided with the distribution. |
58 | * 3. Neither the name of the University nor the names of its contributors |
59 | * may be used to endorse or promote products derived from this software |
60 | * without specific prior written permission. |
61 | * |
62 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
63 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
64 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
65 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
66 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
67 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
68 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
69 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
70 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
71 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
72 | * SUCH DAMAGE. |
73 | * |
74 | * from: Header: subr_autoconf.c,v 1.12 93/02/01 19:31:48 torek Exp (LBL) |
75 | * |
76 | * @(#)subr_autoconf.c 8.3 (Berkeley) 5/17/94 |
77 | */ |
78 | |
79 | #include <sys/cdefs.h> |
80 | __KERNEL_RCSID(0, "$NetBSD: subr_evcnt.c,v 1.12 2014/02/25 18:30:11 pooka Exp $" ); |
81 | |
82 | #include <sys/param.h> |
83 | #include <sys/evcnt.h> |
84 | #include <sys/kmem.h> |
85 | #include <sys/mutex.h> |
86 | #include <sys/sysctl.h> |
87 | #include <sys/systm.h> |
88 | |
89 | /* list of all events */ |
90 | struct evcntlist allevents = TAILQ_HEAD_INITIALIZER(allevents); |
91 | static kmutex_t evcnt_lock __cacheline_aligned; |
92 | static bool init_done; |
93 | static uint32_t evcnt_generation; |
94 | |
95 | /* |
96 | * We need a dummy object to stuff into the evcnt link set to |
97 | * ensure that there always is at least one object in the set. |
98 | */ |
99 | static struct evcnt dummy_static_evcnt; |
100 | __link_set_add_bss(evcnts, dummy_static_evcnt); |
101 | |
102 | /* |
103 | * Initialize event counters. This does the attach procedure for |
104 | * each of the static event counters in the "evcnts" link set. |
105 | */ |
106 | void |
107 | evcnt_init(void) |
108 | { |
109 | __link_set_decl(evcnts, struct evcnt); |
110 | struct evcnt * const *evp; |
111 | |
112 | KASSERT(!init_done); |
113 | |
114 | mutex_init(&evcnt_lock, MUTEX_DEFAULT, IPL_NONE); |
115 | |
116 | init_done = true; |
117 | |
118 | __link_set_foreach(evp, evcnts) { |
119 | if (*evp == &dummy_static_evcnt) |
120 | continue; |
121 | evcnt_attach_static(*evp); |
122 | } |
123 | } |
124 | |
125 | /* |
126 | * Attach a statically-initialized event. The type and string pointers |
127 | * are already set up. |
128 | */ |
129 | void |
130 | evcnt_attach_static(struct evcnt *ev) |
131 | { |
132 | int len; |
133 | |
134 | KASSERTMSG(init_done, |
135 | "%s: evcnt non initialized: group=<%s> name=<%s>" , |
136 | __func__, ev->ev_group, ev->ev_name); |
137 | |
138 | len = strlen(ev->ev_group); |
139 | #ifdef DIAGNOSTIC |
140 | if (len == 0 || len >= EVCNT_STRING_MAX) /* ..._MAX includes NUL */ |
141 | panic("evcnt_attach_static: group length (%s)" , ev->ev_group); |
142 | #endif |
143 | ev->ev_grouplen = len; |
144 | |
145 | len = strlen(ev->ev_name); |
146 | #ifdef DIAGNOSTIC |
147 | if (len == 0 || len >= EVCNT_STRING_MAX) /* ..._MAX includes NUL */ |
148 | panic("evcnt_attach_static: name length (%s)" , ev->ev_name); |
149 | #endif |
150 | ev->ev_namelen = len; |
151 | |
152 | mutex_enter(&evcnt_lock); |
153 | TAILQ_INSERT_TAIL(&allevents, ev, ev_list); |
154 | mutex_exit(&evcnt_lock); |
155 | } |
156 | |
157 | /* |
158 | * Attach a dynamically-initialized event. Zero it, set up the type |
159 | * and string pointers and then act like it was statically initialized. |
160 | */ |
161 | void |
162 | evcnt_attach_dynamic_nozero(struct evcnt *ev, int type, |
163 | const struct evcnt *parent, const char *group, const char *name) |
164 | { |
165 | |
166 | ev->ev_type = type; |
167 | ev->ev_parent = parent; |
168 | ev->ev_group = group; |
169 | ev->ev_name = name; |
170 | evcnt_attach_static(ev); |
171 | } |
172 | /* |
173 | * Attach a dynamically-initialized event. Zero it, set up the type |
174 | * and string pointers and then act like it was statically initialized. |
175 | */ |
176 | void |
177 | evcnt_attach_dynamic(struct evcnt *ev, int type, const struct evcnt *parent, |
178 | const char *group, const char *name) |
179 | { |
180 | |
181 | memset(ev, 0, sizeof *ev); |
182 | evcnt_attach_dynamic_nozero(ev, type, parent, group, name); |
183 | } |
184 | |
185 | /* |
186 | * Detach an event. |
187 | */ |
188 | void |
189 | evcnt_detach(struct evcnt *ev) |
190 | { |
191 | |
192 | mutex_enter(&evcnt_lock); |
193 | TAILQ_REMOVE(&allevents, ev, ev_list); |
194 | evcnt_generation++; |
195 | mutex_exit(&evcnt_lock); |
196 | } |
197 | |
198 | struct xevcnt_sysctl { |
199 | struct evcnt_sysctl evs; |
200 | char ev_strings[2*EVCNT_STRING_MAX]; |
201 | }; |
202 | |
203 | static size_t |
204 | sysctl_fillevcnt(const struct evcnt *ev, struct xevcnt_sysctl *xevs, |
205 | size_t *copylenp) |
206 | { |
207 | const size_t copylen = offsetof(struct evcnt_sysctl, ev_strings) |
208 | + ev->ev_grouplen + 1 + ev->ev_namelen + 1; |
209 | const size_t len = roundup2(copylen, sizeof(uint64_t)); |
210 | if (xevs != NULL) { |
211 | xevs->evs.ev_count = ev->ev_count; |
212 | xevs->evs.ev_addr = PTRTOUINT64(ev); |
213 | xevs->evs.ev_parent = PTRTOUINT64(ev->ev_parent); |
214 | xevs->evs.ev_type = ev->ev_type; |
215 | xevs->evs.ev_grouplen = ev->ev_grouplen; |
216 | xevs->evs.ev_namelen = ev->ev_namelen; |
217 | xevs->evs.ev_len = len / sizeof(uint64_t); |
218 | strcpy(xevs->evs.ev_strings, ev->ev_group); |
219 | strcpy(xevs->evs.ev_strings + ev->ev_grouplen + 1, ev->ev_name); |
220 | } |
221 | |
222 | *copylenp = copylen; |
223 | return len; |
224 | } |
225 | |
226 | static int |
227 | sysctl_doevcnt(SYSCTLFN_ARGS) |
228 | { |
229 | struct xevcnt_sysctl *xevs0 = NULL, *xevs; |
230 | const struct evcnt *ev; |
231 | int error; |
232 | int retries; |
233 | size_t needed, len; |
234 | char *dp; |
235 | |
236 | if (namelen == 1 && name[0] == CTL_QUERY) |
237 | return (sysctl_query(SYSCTLFN_CALL(rnode))); |
238 | |
239 | if (namelen != 2) |
240 | return (EINVAL); |
241 | |
242 | /* |
243 | * We can filter on the type of evcnt. |
244 | */ |
245 | const int filter = name[0]; |
246 | if (filter != EVCNT_TYPE_ANY |
247 | && filter != EVCNT_TYPE_MISC |
248 | && filter != EVCNT_TYPE_INTR |
249 | && filter != EVCNT_TYPE_TRAP) |
250 | return (EINVAL); |
251 | |
252 | const u_int count = name[1]; |
253 | if (count != KERN_EVCNT_COUNT_ANY |
254 | && count != KERN_EVCNT_COUNT_NONZERO) |
255 | return (EINVAL); |
256 | |
257 | sysctl_unlock(); |
258 | |
259 | if (oldp != NULL && xevs0 == NULL) |
260 | xevs0 = kmem_alloc(sizeof(*xevs0), KM_SLEEP); |
261 | |
262 | retries = 100; |
263 | retry: |
264 | dp = oldp; |
265 | len = (oldp != NULL) ? *oldlenp : 0; |
266 | xevs = xevs0; |
267 | error = 0; |
268 | needed = 0; |
269 | |
270 | mutex_enter(&evcnt_lock); |
271 | TAILQ_FOREACH(ev, &allevents, ev_list) { |
272 | if (filter != EVCNT_TYPE_ANY && filter != ev->ev_type) |
273 | continue; |
274 | if (count == KERN_EVCNT_COUNT_NONZERO && ev->ev_count == 0) |
275 | continue; |
276 | |
277 | /* |
278 | * Prepare to copy. If xevs is NULL, fillevcnt will just |
279 | * how big the item is. |
280 | */ |
281 | size_t copylen; |
282 | const size_t elem_size = sysctl_fillevcnt(ev, xevs, ©len); |
283 | needed += elem_size; |
284 | |
285 | if (len < elem_size) { |
286 | xevs = NULL; |
287 | continue; |
288 | } |
289 | |
290 | KASSERT(xevs != NULL); |
291 | KASSERT(xevs->evs.ev_grouplen != 0); |
292 | KASSERT(xevs->evs.ev_namelen != 0); |
293 | KASSERT(xevs->evs.ev_strings[0] != 0); |
294 | |
295 | const uint32_t last_generation = evcnt_generation; |
296 | mutex_exit(&evcnt_lock); |
297 | |
298 | /* |
299 | * Only copy the actual number of bytes, not the rounded |
300 | * number. If we did the latter we'd have to zero them |
301 | * first or we'd leak random kernel memory. |
302 | */ |
303 | error = copyout(xevs, dp, copylen); |
304 | |
305 | mutex_enter(&evcnt_lock); |
306 | if (error) |
307 | break; |
308 | |
309 | if (__predict_false(last_generation != evcnt_generation)) { |
310 | /* |
311 | * This sysctl node is only for statistics. |
312 | * Retry; if the queue keeps changing, then |
313 | * bail out. |
314 | */ |
315 | if (--retries == 0) { |
316 | error = EAGAIN; |
317 | break; |
318 | } |
319 | mutex_exit(&evcnt_lock); |
320 | goto retry; |
321 | } |
322 | |
323 | /* |
324 | * Now we deal with the pointer/len since we aren't going to |
325 | * toss their values away. |
326 | */ |
327 | dp += elem_size; |
328 | len -= elem_size; |
329 | } |
330 | mutex_exit(&evcnt_lock); |
331 | |
332 | if (xevs0 != NULL) |
333 | kmem_free(xevs0, sizeof(*xevs0)); |
334 | |
335 | sysctl_relock(); |
336 | |
337 | *oldlenp = needed; |
338 | if (oldp == NULL) |
339 | *oldlenp += 1024; |
340 | |
341 | return (error); |
342 | } |
343 | |
344 | |
345 | |
346 | SYSCTL_SETUP(sysctl_evcnt_setup, "sysctl kern.evcnt subtree setup" ) |
347 | { |
348 | |
349 | sysctl_createv(clog, 0, NULL, NULL, |
350 | CTLFLAG_PERMANENT, |
351 | CTLTYPE_STRUCT, "evcnt" , |
352 | SYSCTL_DESCR("Kernel evcnt information" ), |
353 | sysctl_doevcnt, 0, NULL, 0, |
354 | CTL_KERN, KERN_EVCNT, CTL_EOL); |
355 | } |
356 | |