1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21 /*
22 * Copyright 2009 Sun Microsystems, Inc. All rights reserved.
23 * Use is subject to license terms.
24 */
25
26
27 #include <sys/errno.h>
28 #include <sys/stat.h>
29 #include <sys/modctl.h>
30 #include <sys/conf.h>
31 #include <sys/systm.h>
32 #include <sys/ddi.h>
33 #include <sys/sunddi.h>
34 #include <sys/cpuvar.h>
35 #include <sys/kmem.h>
36 #include <sys/strsubr.h>
37 #include <sys/dtrace.h>
38 #include <sys/cyclic.h>
39 #include <sys/atomic.h>
40
41 static dev_info_t *profile_devi;
42 static dtrace_provider_id_t profile_id;
43
44 /*
45 * Regardless of platform, the stack frames look like this in the case of the
46 * profile provider:
47 *
48 * profile_fire
49 * cyclic_expire
50 * cyclic_fire
51 * [ cbe ]
52 * [ interrupt code ]
53 *
54 * On x86, there are five frames from the generic interrupt code; further, the
55 * interrupted instruction appears as its own stack frame, giving us a total of
56 * 10.
57 *
58 * On SPARC, the picture is further complicated because the compiler
59 * optimizes away tail-calls -- so the following frames are optimized away:
60 *
61 * profile_fire
62 * cyclic_expire
63 *
64 * This gives three frames. However, on DEBUG kernels, the cyclic_expire
65 * frame cannot be tail-call eliminated, yielding four frames in this case.
66 *
67 * All of the above constraints lead to the mess below. Yes, the profile
68 * provider should ideally figure this out on-the-fly by hitting one of its own
69 * probes and then walking its own stack trace. This is complicated, however,
70 * and the static definition doesn't seem to be overly brittle. Still, we
71 * allow for a manual override in case we get it completely wrong.
72 */
73 #ifdef __x86
74 #define PROF_ARTIFICIAL_FRAMES 10
75 #else
76 #ifdef __sparc
77 #ifdef DEBUG
78 #define PROF_ARTIFICIAL_FRAMES 4
79 #else
80 #define PROF_ARTIFICIAL_FRAMES 3
81 #endif
82 #endif
83 #endif
84
85 #define PROF_NAMELEN 15
86
87 #define PROF_PROFILE 0
88 #define PROF_TICK 1
89 #define PROF_PREFIX_PROFILE "profile-"
90 #define PROF_PREFIX_TICK "tick-"
91
92 typedef struct profile_probe {
93 char prof_name[PROF_NAMELEN];
94 dtrace_id_t prof_id;
95 int prof_kind;
96 hrtime_t prof_interval;
97 cyclic_id_t prof_cyclic;
98 } profile_probe_t;
99
100 typedef struct profile_probe_percpu {
101 hrtime_t profc_expected;
102 hrtime_t profc_interval;
103 profile_probe_t *profc_probe;
104 } profile_probe_percpu_t;
105
106 hrtime_t profile_interval_min = NANOSEC / 5000; /* 5000 hz */
107 int profile_aframes = 0; /* override */
108
109 static int profile_rates[] = {
110 97, 199, 499, 997, 1999,
111 4001, 4999, 0, 0, 0,
112 0, 0, 0, 0, 0,
113 0, 0, 0, 0, 0
114 };
115
116 static int profile_ticks[] = {
117 1, 10, 100, 500, 1000,
118 5000, 0, 0, 0, 0,
119 0, 0, 0, 0, 0
120 };
121
122 /*
123 * profile_max defines the upper bound on the number of profile probes that
124 * can exist (this is to prevent malicious or clumsy users from exhausing
125 * system resources by creating a slew of profile probes). At mod load time,
126 * this gets its value from PROFILE_MAX_DEFAULT or profile-max-probes if it's
127 * present in the profile.conf file.
128 */
129 #define PROFILE_MAX_DEFAULT 1000 /* default max. number of probes */
130 static uint32_t profile_max; /* maximum number of profile probes */
131 static uint32_t profile_total; /* current number of profile probes */
132
133 static void
profile_fire(void * arg)134 profile_fire(void *arg)
135 {
136 profile_probe_percpu_t *pcpu = arg;
137 profile_probe_t *prof = pcpu->profc_probe;
138 hrtime_t late;
139
140 late = dtrace_gethrtime() - pcpu->profc_expected;
141 pcpu->profc_expected += pcpu->profc_interval;
142
143 dtrace_probe(prof->prof_id, CPU->cpu_profile_pc,
144 CPU->cpu_profile_upc, late, 0, 0);
145 }
146
147 static void
profile_tick(void * arg)148 profile_tick(void *arg)
149 {
150 profile_probe_t *prof = arg;
151
152 dtrace_probe(prof->prof_id, CPU->cpu_profile_pc,
153 CPU->cpu_profile_upc, 0, 0, 0);
154 }
155
156 static void
profile_create(hrtime_t interval,const char * name,int kind)157 profile_create(hrtime_t interval, const char *name, int kind)
158 {
159 profile_probe_t *prof;
160 int nr_frames = PROF_ARTIFICIAL_FRAMES + dtrace_mach_aframes();
161
162 if (profile_aframes)
163 nr_frames = profile_aframes;
164
165 if (interval < profile_interval_min)
166 return;
167
168 if (dtrace_probe_lookup(profile_id, NULL, NULL, name) != 0)
169 return;
170
171 atomic_add_32(&profile_total, 1);
172 if (profile_total > profile_max) {
173 atomic_add_32(&profile_total, -1);
174 return;
175 }
176
177 prof = kmem_zalloc(sizeof (profile_probe_t), KM_SLEEP);
178 (void) strcpy(prof->prof_name, name);
179 prof->prof_interval = interval;
180 prof->prof_cyclic = CYCLIC_NONE;
181 prof->prof_kind = kind;
182 prof->prof_id = dtrace_probe_create(profile_id,
183 NULL, NULL, name, nr_frames, prof);
184 }
185
186 /*ARGSUSED*/
187 static void
profile_provide(void * arg,const dtrace_probedesc_t * desc)188 profile_provide(void *arg, const dtrace_probedesc_t *desc)
189 {
190 int i, j, rate, kind;
191 hrtime_t val = 0, mult = 1, len;
192 const char *name, *suffix = NULL;
193
194 const struct {
195 char *prefix;
196 int kind;
197 } types[] = {
198 { PROF_PREFIX_PROFILE, PROF_PROFILE },
199 { PROF_PREFIX_TICK, PROF_TICK },
200 { NULL, NULL }
201 };
202
203 const struct {
204 char *name;
205 hrtime_t mult;
206 } suffixes[] = {
207 { "ns", NANOSEC / NANOSEC },
208 { "nsec", NANOSEC / NANOSEC },
209 { "us", NANOSEC / MICROSEC },
210 { "usec", NANOSEC / MICROSEC },
211 { "ms", NANOSEC / MILLISEC },
212 { "msec", NANOSEC / MILLISEC },
213 { "s", NANOSEC / SEC },
214 { "sec", NANOSEC / SEC },
215 { "m", NANOSEC * (hrtime_t)60 },
216 { "min", NANOSEC * (hrtime_t)60 },
217 { "h", NANOSEC * (hrtime_t)(60 * 60) },
218 { "hour", NANOSEC * (hrtime_t)(60 * 60) },
219 { "d", NANOSEC * (hrtime_t)(24 * 60 * 60) },
220 { "day", NANOSEC * (hrtime_t)(24 * 60 * 60) },
221 { "hz", 0 },
222 { NULL }
223 };
224
225 if (desc == NULL) {
226 char n[PROF_NAMELEN];
227
228 /*
229 * If no description was provided, provide all of our probes.
230 */
231 for (i = 0; i < sizeof (profile_rates) / sizeof (int); i++) {
232 if ((rate = profile_rates[i]) == 0)
233 continue;
234
235 (void) snprintf(n, PROF_NAMELEN, "%s%d",
236 PROF_PREFIX_PROFILE, rate);
237 profile_create(NANOSEC / rate, n, PROF_PROFILE);
238 }
239
240 for (i = 0; i < sizeof (profile_ticks) / sizeof (int); i++) {
241 if ((rate = profile_ticks[i]) == 0)
242 continue;
243
244 (void) snprintf(n, PROF_NAMELEN, "%s%d",
245 PROF_PREFIX_TICK, rate);
246 profile_create(NANOSEC / rate, n, PROF_TICK);
247 }
248
249 return;
250 }
251
252 name = desc->dtpd_name;
253
254 for (i = 0; types[i].prefix != NULL; i++) {
255 len = strlen(types[i].prefix);
256
257 if (strncmp(name, types[i].prefix, len) != 0)
258 continue;
259 break;
260 }
261
262 if (types[i].prefix == NULL)
263 return;
264
265 kind = types[i].kind;
266 j = strlen(name) - len;
267
268 /*
269 * We need to start before any time suffix.
270 */
271 for (j = strlen(name); j >= len; j--) {
272 if (name[j] >= '0' && name[j] <= '9')
273 break;
274 suffix = &name[j];
275 }
276
277 ASSERT(suffix != NULL);
278
279 /*
280 * Now determine the numerical value present in the probe name.
281 */
282 for (; j >= len; j--) {
283 if (name[j] < '0' || name[j] > '9')
284 return;
285
286 val += (name[j] - '0') * mult;
287 mult *= (hrtime_t)10;
288 }
289
290 if (val == 0)
291 return;
292
293 /*
294 * Look-up the suffix to determine the multiplier.
295 */
296 for (i = 0, mult = 0; suffixes[i].name != NULL; i++) {
297 if (strcasecmp(suffixes[i].name, suffix) == 0) {
298 mult = suffixes[i].mult;
299 break;
300 }
301 }
302
303 if (suffixes[i].name == NULL && *suffix != '\0')
304 return;
305
306 if (mult == 0) {
307 /*
308 * The default is frequency-per-second.
309 */
310 val = NANOSEC / val;
311 } else {
312 val *= mult;
313 }
314
315 profile_create(val, name, kind);
316 }
317
318 /*ARGSUSED*/
319 static void
profile_destroy(void * arg,dtrace_id_t id,void * parg)320 profile_destroy(void *arg, dtrace_id_t id, void *parg)
321 {
322 profile_probe_t *prof = parg;
323
324 ASSERT(prof->prof_cyclic == CYCLIC_NONE);
325 kmem_free(prof, sizeof (profile_probe_t));
326
327 ASSERT(profile_total >= 1);
328 atomic_add_32(&profile_total, -1);
329 }
330
331 /*ARGSUSED*/
332 static void
profile_online(void * arg,cpu_t * cpu,cyc_handler_t * hdlr,cyc_time_t * when)333 profile_online(void *arg, cpu_t *cpu, cyc_handler_t *hdlr, cyc_time_t *when)
334 {
335 profile_probe_t *prof = arg;
336 profile_probe_percpu_t *pcpu;
337
338 pcpu = kmem_zalloc(sizeof (profile_probe_percpu_t), KM_SLEEP);
339 pcpu->profc_probe = prof;
340
341 hdlr->cyh_func = profile_fire;
342 hdlr->cyh_arg = pcpu;
343 hdlr->cyh_level = CY_HIGH_LEVEL;
344
345 when->cyt_interval = prof->prof_interval;
346 when->cyt_when = dtrace_gethrtime() + when->cyt_interval;
347
348 pcpu->profc_expected = when->cyt_when;
349 pcpu->profc_interval = when->cyt_interval;
350 }
351
352 /*ARGSUSED*/
353 static void
profile_offline(void * arg,cpu_t * cpu,void * oarg)354 profile_offline(void *arg, cpu_t *cpu, void *oarg)
355 {
356 profile_probe_percpu_t *pcpu = oarg;
357
358 ASSERT(pcpu->profc_probe == arg);
359 kmem_free(pcpu, sizeof (profile_probe_percpu_t));
360 }
361
362 /*ARGSUSED*/
363 static int
profile_enable(void * arg,dtrace_id_t id,void * parg)364 profile_enable(void *arg, dtrace_id_t id, void *parg)
365 {
366 profile_probe_t *prof = parg;
367 cyc_omni_handler_t omni;
368 cyc_handler_t hdlr;
369 cyc_time_t when;
370
371 ASSERT(prof->prof_interval != 0);
372 ASSERT(MUTEX_HELD(&cpu_lock));
373
374 if (prof->prof_kind == PROF_TICK) {
375 hdlr.cyh_func = profile_tick;
376 hdlr.cyh_arg = prof;
377 hdlr.cyh_level = CY_HIGH_LEVEL;
378
379 when.cyt_interval = prof->prof_interval;
380 when.cyt_when = dtrace_gethrtime() + when.cyt_interval;
381 } else {
382 ASSERT(prof->prof_kind == PROF_PROFILE);
383 omni.cyo_online = profile_online;
384 omni.cyo_offline = profile_offline;
385 omni.cyo_arg = prof;
386 }
387
388 if (prof->prof_kind == PROF_TICK) {
389 prof->prof_cyclic = cyclic_add(&hdlr, &when);
390 } else {
391 prof->prof_cyclic = cyclic_add_omni(&omni);
392 }
393 return (0);
394 }
395
396 /*ARGSUSED*/
397 static void
profile_disable(void * arg,dtrace_id_t id,void * parg)398 profile_disable(void *arg, dtrace_id_t id, void *parg)
399 {
400 profile_probe_t *prof = parg;
401
402 ASSERT(prof->prof_cyclic != CYCLIC_NONE);
403 ASSERT(MUTEX_HELD(&cpu_lock));
404
405 cyclic_remove(prof->prof_cyclic);
406 prof->prof_cyclic = CYCLIC_NONE;
407 }
408
409 /*ARGSUSED*/
410 static int
profile_usermode(void * arg,dtrace_id_t id,void * parg)411 profile_usermode(void *arg, dtrace_id_t id, void *parg)
412 {
413 return (CPU->cpu_profile_pc == 0);
414 }
415
416 static dtrace_pattr_t profile_attr = {
417 { DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_COMMON },
418 { DTRACE_STABILITY_UNSTABLE, DTRACE_STABILITY_UNSTABLE, DTRACE_CLASS_UNKNOWN },
419 { DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_UNKNOWN },
420 { DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_COMMON },
421 { DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_COMMON },
422 };
423
424 static dtrace_pops_t profile_pops = {
425 profile_provide,
426 NULL,
427 profile_enable,
428 profile_disable,
429 NULL,
430 NULL,
431 NULL,
432 NULL,
433 profile_usermode,
434 profile_destroy
435 };
436
437 static int
profile_attach(dev_info_t * devi,ddi_attach_cmd_t cmd)438 profile_attach(dev_info_t *devi, ddi_attach_cmd_t cmd)
439 {
440 switch (cmd) {
441 case DDI_ATTACH:
442 break;
443 case DDI_RESUME:
444 return (DDI_SUCCESS);
445 default:
446 return (DDI_FAILURE);
447 }
448
449 if (ddi_create_minor_node(devi, "profile", S_IFCHR, 0,
450 DDI_PSEUDO, NULL) == DDI_FAILURE ||
451 dtrace_register("profile", &profile_attr,
452 DTRACE_PRIV_KERNEL | DTRACE_PRIV_USER, NULL,
453 &profile_pops, NULL, &profile_id) != 0) {
454 ddi_remove_minor_node(devi, NULL);
455 return (DDI_FAILURE);
456 }
457
458 profile_max = ddi_getprop(DDI_DEV_T_ANY, devi, DDI_PROP_DONTPASS,
459 "profile-max-probes", PROFILE_MAX_DEFAULT);
460
461 ddi_report_dev(devi);
462 profile_devi = devi;
463 return (DDI_SUCCESS);
464 }
465
466 static int
profile_detach(dev_info_t * devi,ddi_detach_cmd_t cmd)467 profile_detach(dev_info_t *devi, ddi_detach_cmd_t cmd)
468 {
469 switch (cmd) {
470 case DDI_DETACH:
471 break;
472 case DDI_SUSPEND:
473 return (DDI_SUCCESS);
474 default:
475 return (DDI_FAILURE);
476 }
477
478 if (dtrace_unregister(profile_id) != 0)
479 return (DDI_FAILURE);
480
481 ddi_remove_minor_node(devi, NULL);
482 return (DDI_SUCCESS);
483 }
484
485 /*ARGSUSED*/
486 static int
profile_info(dev_info_t * dip,ddi_info_cmd_t infocmd,void * arg,void ** result)487 profile_info(dev_info_t *dip, ddi_info_cmd_t infocmd, void *arg, void **result)
488 {
489 int error;
490
491 switch (infocmd) {
492 case DDI_INFO_DEVT2DEVINFO:
493 *result = (void *)profile_devi;
494 error = DDI_SUCCESS;
495 break;
496 case DDI_INFO_DEVT2INSTANCE:
497 *result = (void *)0;
498 error = DDI_SUCCESS;
499 break;
500 default:
501 error = DDI_FAILURE;
502 }
503 return (error);
504 }
505
506 /*ARGSUSED*/
507 static int
profile_open(dev_t * devp,int flag,int otyp,cred_t * cred_p)508 profile_open(dev_t *devp, int flag, int otyp, cred_t *cred_p)
509 {
510 return (0);
511 }
512
513 static struct cb_ops profile_cb_ops = {
514 profile_open, /* open */
515 nodev, /* close */
516 nulldev, /* strategy */
517 nulldev, /* print */
518 nodev, /* dump */
519 nodev, /* read */
520 nodev, /* write */
521 nodev, /* ioctl */
522 nodev, /* devmap */
523 nodev, /* mmap */
524 nodev, /* segmap */
525 nochpoll, /* poll */
526 ddi_prop_op, /* cb_prop_op */
527 0, /* streamtab */
528 D_NEW | D_MP /* Driver compatibility flag */
529 };
530
531 static struct dev_ops profile_ops = {
532 DEVO_REV, /* devo_rev, */
533 0, /* refcnt */
534 profile_info, /* get_dev_info */
535 nulldev, /* identify */
536 nulldev, /* probe */
537 profile_attach, /* attach */
538 profile_detach, /* detach */
539 nodev, /* reset */
540 &profile_cb_ops, /* driver operations */
541 NULL, /* bus operations */
542 nodev, /* dev power */
543 ddi_quiesce_not_needed, /* quiesce */
544 };
545
546 /*
547 * Module linkage information for the kernel.
548 */
549 static struct modldrv modldrv = {
550 &mod_driverops, /* module type (this is a pseudo driver) */
551 "Profile Interrupt Tracing", /* name of module */
552 &profile_ops, /* driver ops */
553 };
554
555 static struct modlinkage modlinkage = {
556 MODREV_1,
557 (void *)&modldrv,
558 NULL
559 };
560
561 int
_init(void)562 _init(void)
563 {
564 return (mod_install(&modlinkage));
565 }
566
567 int
_info(struct modinfo * modinfop)568 _info(struct modinfo *modinfop)
569 {
570 return (mod_info(&modlinkage, modinfop));
571 }
572
573 int
_fini(void)574 _fini(void)
575 {
576 return (mod_remove(&modlinkage));
577 }
578