| 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 | |