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/modctl.h>
28 #include <sys/sunddi.h>
29 #include <sys/dtrace.h>
30 #include <sys/kobj.h>
31 #include <sys/stat.h>
32 #include <sys/conf.h>
33 #include <vm/seg_kmem.h>
34 #include <sys/stack.h>
35 #include <sys/sdt_impl.h>
36
37 static dev_info_t *sdt_devi;
38
39 int sdt_verbose = 0;
40
41 #define SDT_REG_G0 0
42 #define SDT_REG_O0 8
43 #define SDT_REG_O1 9
44 #define SDT_REG_O2 10
45 #define SDT_REG_O3 11
46 #define SDT_REG_O4 12
47 #define SDT_REG_O5 13
48 #define SDT_REG_I0 24
49 #define SDT_REG_I1 25
50 #define SDT_REG_I2 26
51 #define SDT_REG_I3 27
52 #define SDT_REG_I4 28
53 #define SDT_REG_I5 29
54
55 #define SDT_SIMM13_MASK 0x1fff
56 #define SDT_SIMM13_MAX ((int32_t)0xfff)
57 #define SDT_CALL(from, to) (((uint32_t)1 << 30) | \
58 (((uintptr_t)(to) - (uintptr_t)(from) >> 2) & \
59 0x3fffffff))
60 #define SDT_SAVE (0x9de3a000 | (-SA(MINFRAME) & SDT_SIMM13_MASK))
61 #define SDT_RET 0x81c7e008
62 #define SDT_RESTORE 0x81e80000
63
64 #define SDT_OP_SETHI 0x1000000
65 #define SDT_OP_OR 0x80100000
66
67 #define SDT_FMT2_RD_SHIFT 25
68 #define SDT_IMM22_SHIFT 10
69 #define SDT_IMM22_MASK 0x3fffff
70 #define SDT_IMM10_MASK 0x3ff
71
72 #define SDT_FMT3_RD_SHIFT 25
73 #define SDT_FMT3_RS1_SHIFT 14
74 #define SDT_FMT3_RS2_SHIFT 0
75 #define SDT_FMT3_IMM (1 << 13)
76
77 #define SDT_MOV(rs, rd) \
78 (SDT_OP_OR | (SDT_REG_G0 << SDT_FMT3_RS1_SHIFT) | \
79 ((rs) << SDT_FMT3_RS2_SHIFT) | ((rd) << SDT_FMT3_RD_SHIFT))
80
81 #define SDT_ORLO(rs, val, rd) \
82 (SDT_OP_OR | ((rs) << SDT_FMT3_RS1_SHIFT) | \
83 ((rd) << SDT_FMT3_RD_SHIFT) | SDT_FMT3_IMM | ((val) & SDT_IMM10_MASK))
84
85 #define SDT_ORSIMM13(rs, val, rd) \
86 (SDT_OP_OR | ((rs) << SDT_FMT3_RS1_SHIFT) | \
87 ((rd) << SDT_FMT3_RD_SHIFT) | SDT_FMT3_IMM | ((val) & SDT_SIMM13_MASK))
88
89 #define SDT_SETHI(val, reg) \
90 (SDT_OP_SETHI | (reg << SDT_FMT2_RD_SHIFT) | \
91 ((val >> SDT_IMM22_SHIFT) & SDT_IMM22_MASK))
92
93 #define SDT_ENTRY_SIZE (11 * sizeof (uint32_t))
94
95 static void
96 sdt_initialize(sdt_probe_t *sdp, uint32_t **trampoline)
97 {
98 uint32_t *instr = *trampoline;
99
100 *instr++ = SDT_SAVE;
101
102 if (sdp->sdp_id > (uint32_t)SDT_SIMM13_MAX) {
103 *instr++ = SDT_SETHI(sdp->sdp_id, SDT_REG_O0);
104 *instr++ = SDT_ORLO(SDT_REG_O0, sdp->sdp_id, SDT_REG_O0);
105 } else {
106 *instr++ = SDT_ORSIMM13(SDT_REG_G0, sdp->sdp_id, SDT_REG_O0);
107 }
108
109 *instr++ = SDT_MOV(SDT_REG_I0, SDT_REG_O1);
110 *instr++ = SDT_MOV(SDT_REG_I1, SDT_REG_O2);
111 *instr++ = SDT_MOV(SDT_REG_I2, SDT_REG_O3);
112 *instr++ = SDT_MOV(SDT_REG_I3, SDT_REG_O4);
113 *instr = SDT_CALL(instr, dtrace_probe);
114 instr++;
115 *instr++ = SDT_MOV(SDT_REG_I4, SDT_REG_O5);
116
117 *instr++ = SDT_RET;
118 *instr++ = SDT_RESTORE;
119 *trampoline = instr;
120 }
121
122 /*ARGSUSED*/
123 static void
124 sdt_provide_module(void *arg, struct modctl *ctl)
125 {
126 struct module *mp = ctl->mod_mp;
127 char *modname = ctl->mod_modname;
128 int primary, nprobes = 0;
129 sdt_probedesc_t *sdpd;
130 sdt_probe_t *sdp, *old;
131 uint32_t *tab;
132 sdt_provider_t *prov;
133 int len;
134
135 /*
136 * One for all, and all for one: if we haven't yet registered all of
137 * our providers, we'll refuse to provide anything.
138 */
139 for (prov = sdt_providers; prov->sdtp_name != NULL; prov++) {
140 if (prov->sdtp_id == DTRACE_PROVNONE)
141 return;
142 }
143
144 if (mp->sdt_nprobes != 0 || (sdpd = mp->sdt_probes) == NULL)
145 return;
146
147 kobj_textwin_alloc(mp);
148
149 /*
150 * Hack to identify unix/genunix/krtld.
151 */
152 primary = vmem_contains(heap_arena, (void *)ctl,
153 sizeof (struct modctl)) == 0;
154
155 /*
156 * If there hasn't been an sdt table allocated, we'll do so now.
157 */
158 if (mp->sdt_tab == NULL) {
159 for (; sdpd != NULL; sdpd = sdpd->sdpd_next) {
160 nprobes++;
161 }
162
163 /*
164 * We could (should?) determine precisely the size of the
165 * table -- but a reasonable maximum will suffice.
166 */
167 mp->sdt_size = nprobes * SDT_ENTRY_SIZE;
168 mp->sdt_tab = kobj_texthole_alloc(mp->text, mp->sdt_size);
169
170 if (mp->sdt_tab == NULL) {
171 cmn_err(CE_WARN, "couldn't allocate SDT table "
172 "for module %s", modname);
173 return;
174 }
175 }
176
177 tab = (uint32_t *)mp->sdt_tab;
178
179 for (sdpd = mp->sdt_probes; sdpd != NULL; sdpd = sdpd->sdpd_next) {
180 char *name = sdpd->sdpd_name, *func, *nname;
181 int i, j;
182 sdt_provider_t *prov;
183 ulong_t offs;
184 dtrace_id_t id;
185
186 for (prov = sdt_providers; prov->sdtp_prefix != NULL; prov++) {
187 char *prefix = prov->sdtp_prefix;
188
189 if (strncmp(name, prefix, strlen(prefix)) == 0) {
190 name += strlen(prefix);
191 break;
192 }
193 }
194
195 nname = kmem_alloc(len = strlen(name) + 1, KM_SLEEP);
196
197 for (i = 0, j = 0; name[j] != '\0'; i++) {
198 if (name[j] == '_' && name[j + 1] == '_') {
199 nname[i] = '-';
200 j += 2;
201 } else {
202 nname[i] = name[j++];
203 }
204 }
205
206 nname[i] = '\0';
207
208 sdp = kmem_zalloc(sizeof (sdt_probe_t), KM_SLEEP);
209 sdp->sdp_loadcnt = ctl->mod_loadcnt;
210 sdp->sdp_primary = primary;
211 sdp->sdp_ctl = ctl;
212 sdp->sdp_name = nname;
213 sdp->sdp_namelen = len;
214 sdp->sdp_provider = prov;
215
216 func = kobj_searchsym(mp, sdpd->sdpd_offset +
217 (uintptr_t)mp->text, &offs);
218
219 if (func == NULL)
220 func = "<unknown>";
221
222 /*
223 * We have our provider. Now create the probe.
224 */
225 if ((id = dtrace_probe_lookup(prov->sdtp_id, modname,
226 func, nname)) != DTRACE_IDNONE) {
227 old = dtrace_probe_arg(prov->sdtp_id, id);
228 ASSERT(old != NULL);
229
230 sdp->sdp_next = old->sdp_next;
231 sdp->sdp_id = id;
232 old->sdp_next = sdp;
233 } else {
234 sdp->sdp_id = dtrace_probe_create(prov->sdtp_id,
235 modname, func, nname, 1, sdp);
236
237 mp->sdt_nprobes++;
238 }
239
240 sdp->sdp_patchval = SDT_CALL((uintptr_t)mp->text +
241 sdpd->sdpd_offset, tab);
242 sdp->sdp_patchpoint = (uint32_t *)((uintptr_t)mp->textwin +
243 sdpd->sdpd_offset);
244 sdp->sdp_savedval = *sdp->sdp_patchpoint;
245 sdt_initialize(sdp, &tab);
246 }
247 }
248
249 /*ARGSUSED*/
250 static void
251 sdt_destroy(void *arg, dtrace_id_t id, void *parg)
252 {
253 sdt_probe_t *sdp = parg, *old;
254 struct modctl *ctl = sdp->sdp_ctl;
255
256 if (ctl != NULL && ctl->mod_loadcnt == sdp->sdp_loadcnt) {
257 if ((ctl->mod_loadcnt == sdp->sdp_loadcnt &&
258 ctl->mod_loaded) || sdp->sdp_primary) {
259 ((struct module *)(ctl->mod_mp))->sdt_nprobes--;
260 }
261 }
262
263 while (sdp != NULL) {
264 old = sdp;
265 kmem_free(sdp->sdp_name, sdp->sdp_namelen);
266 sdp = sdp->sdp_next;
267 kmem_free(old, sizeof (sdt_probe_t));
268 }
269 }
270
271 /*ARGSUSED*/
272 static int
273 sdt_enable(void *arg, dtrace_id_t id, void *parg)
274 {
275 sdt_probe_t *sdp = parg;
276 struct modctl *ctl = sdp->sdp_ctl;
277
278 ctl->mod_nenabled++;
279
280 /*
281 * If this module has disappeared since we discovered its probes,
282 * refuse to enable it.
283 */
284 if (!sdp->sdp_primary && !ctl->mod_loaded) {
285 if (sdt_verbose) {
286 cmn_err(CE_NOTE, "sdt is failing for probe %s "
287 "(module %s unloaded)",
288 sdp->sdp_name, ctl->mod_modname);
289 }
290 goto err;
291 }
292
293 /*
294 * Now check that our modctl has the expected load count. If it
295 * doesn't, this module must have been unloaded and reloaded -- and
296 * we're not going to touch it.
297 */
298 if (ctl->mod_loadcnt != sdp->sdp_loadcnt) {
299 if (sdt_verbose) {
300 cmn_err(CE_NOTE, "sdt is failing for probe %s "
301 "(module %s reloaded)",
302 sdp->sdp_name, ctl->mod_modname);
303 }
304 goto err;
305 }
306
307 while (sdp != NULL) {
308 *sdp->sdp_patchpoint = sdp->sdp_patchval;
309 sdp = sdp->sdp_next;
310 }
311
312 err:
313 return (0);
314 }
315
316 /*ARGSUSED*/
317 static void
318 sdt_disable(void *arg, dtrace_id_t id, void *parg)
319 {
320 sdt_probe_t *sdp = parg;
321 struct modctl *ctl = sdp->sdp_ctl;
322
323 ASSERT(ctl->mod_nenabled > 0);
324 ctl->mod_nenabled--;
325
326 if ((!sdp->sdp_primary && !ctl->mod_loaded) ||
327 (ctl->mod_loadcnt != sdp->sdp_loadcnt))
328 goto err;
329
330 while (sdp != NULL) {
331 *sdp->sdp_patchpoint = sdp->sdp_savedval;
332 sdp = sdp->sdp_next;
333 }
334
335 err:
336 ;
337 }
338
339 static dtrace_pops_t sdt_pops = {
340 NULL,
341 sdt_provide_module,
342 sdt_enable,
343 sdt_disable,
344 NULL,
345 NULL,
346 sdt_getargdesc,
347 NULL,
348 NULL,
349 sdt_destroy
350 };
351
352 static int
353 sdt_attach(dev_info_t *devi, ddi_attach_cmd_t cmd)
354 {
355 sdt_provider_t *prov;
356
357 switch (cmd) {
358 case DDI_ATTACH:
359 break;
360 case DDI_RESUME:
361 return (DDI_SUCCESS);
362 default:
363 return (DDI_FAILURE);
364 }
365
366 if (ddi_create_minor_node(devi, "sdt", S_IFCHR, 0,
367 DDI_PSEUDO, NULL) == DDI_FAILURE) {
368 ddi_remove_minor_node(devi, NULL);
369 return (DDI_FAILURE);
370 }
371
372 ddi_report_dev(devi);
373 sdt_devi = devi;
374
375 for (prov = sdt_providers; prov->sdtp_name != NULL; prov++) {
376 if (dtrace_register(prov->sdtp_name, prov->sdtp_attr,
377 DTRACE_PRIV_KERNEL, NULL,
378 &sdt_pops, prov, &prov->sdtp_id) != 0) {
379 cmn_err(CE_WARN, "failed to register sdt provider %s",
380 prov->sdtp_name);
381 }
382 }
383
384 return (DDI_SUCCESS);
385 }
386
387 static int
388 sdt_detach(dev_info_t *devi, ddi_detach_cmd_t cmd)
389 {
390 sdt_provider_t *prov;
391
392 switch (cmd) {
393 case DDI_DETACH:
394 break;
395 case DDI_SUSPEND:
396 return (DDI_SUCCESS);
397 default:
398 return (DDI_FAILURE);
399 }
400
401 for (prov = sdt_providers; prov->sdtp_name != NULL; prov++) {
402 if (prov->sdtp_id != DTRACE_PROVNONE) {
403 if (dtrace_unregister(prov->sdtp_id) != 0)
404 return (DDI_FAILURE);
405 prov->sdtp_id = DTRACE_PROVNONE;
406 }
407 }
408
409 ddi_remove_minor_node(devi, NULL);
410 return (DDI_SUCCESS);
411 }
412
413 /*ARGSUSED*/
414 static int
415 sdt_info(dev_info_t *dip, ddi_info_cmd_t infocmd, void *arg, void **result)
416 {
417 int error;
418
419 switch (infocmd) {
420 case DDI_INFO_DEVT2DEVINFO:
421 *result = (void *)sdt_devi;
422 error = DDI_SUCCESS;
423 break;
424 case DDI_INFO_DEVT2INSTANCE:
425 *result = (void *)0;
426 error = DDI_SUCCESS;
427 break;
428 default:
429 error = DDI_FAILURE;
430 }
431 return (error);
432 }
433
434 /*ARGSUSED*/
435 static int
436 sdt_open(dev_t *devp, int flag, int otyp, cred_t *cred_p)
437 {
438 return (0);
439 }
440
441 static struct cb_ops sdt_cb_ops = {
442 sdt_open, /* open */
443 nodev, /* close */
444 nulldev, /* strategy */
445 nulldev, /* print */
446 nodev, /* dump */
447 nodev, /* read */
448 nodev, /* write */
449 nodev, /* ioctl */
450 nodev, /* devmap */
451 nodev, /* mmap */
452 nodev, /* segmap */
453 nochpoll, /* poll */
454 ddi_prop_op, /* cb_prop_op */
455 0, /* streamtab */
456 D_NEW | D_MP /* Driver compatibility flag */
457 };
458
459 static struct dev_ops sdt_ops = {
460 DEVO_REV, /* devo_rev, */
461 0, /* refcnt */
462 sdt_info, /* get_dev_info */
463 nulldev, /* identify */
464 nulldev, /* probe */
465 sdt_attach, /* attach */
466 sdt_detach, /* detach */
467 nodev, /* reset */
468 &sdt_cb_ops, /* driver operations */
469 NULL, /* bus operations */
470 nodev, /* dev power */
471 ddi_quiesce_not_needed, /* quiesce */
472 };
473
474 /*
475 * Module linkage information for the kernel.
476 */
477 static struct modldrv modldrv = {
478 &mod_driverops, /* module type (this is a pseudo driver) */
479 "Statically Defined Tracing", /* name of module */
480 &sdt_ops, /* driver ops */
481 };
482
483 static struct modlinkage modlinkage = {
484 MODREV_1,
485 (void *)&modldrv,
486 NULL
487 };
488
489 int
490 _init(void)
491 {
492 return (mod_install(&modlinkage));
493 }
494
495 int
496 _info(struct modinfo *modinfop)
497 {
498 return (mod_info(&modlinkage, modinfop));
499 }
500
501 int
502 _fini(void)
503 {
504 return (mod_remove(&modlinkage));
505 }