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 * Copyright (c) 2012, Joyent, Inc. All rights reserved. 28 */ 29 30 #include <sys/modctl.h> 31 #include <sys/sunddi.h> 32 #include <sys/dtrace.h> 33 #include <sys/kobj.h> 34 #include <sys/stat.h> 35 #include <sys/conf.h> 36 #include <vm/seg_kmem.h> 37 #include <sys/stack.h> 38 #include <sys/sdt_impl.h> 39 40 static dev_info_t *sdt_devi; 41 42 int sdt_verbose = 0; 43 44 #define SDT_REG_G0 0 45 #define SDT_REG_O0 8 46 #define SDT_REG_O1 9 47 #define SDT_REG_O2 10 48 #define SDT_REG_O3 11 49 #define SDT_REG_O4 12 50 #define SDT_REG_O5 13 51 #define SDT_REG_I0 24 52 #define SDT_REG_I1 25 53 #define SDT_REG_I2 26 54 #define SDT_REG_I3 27 55 #define SDT_REG_I4 28 56 #define SDT_REG_I5 29 57 58 #define SDT_SIMM13_MASK 0x1fff 59 #define SDT_SIMM13_MAX ((int32_t)0xfff) 60 #define SDT_CALL(from, to) (((uint32_t)1 << 30) | \ 61 (((uintptr_t)(to) - (uintptr_t)(from) >> 2) & \ 62 0x3fffffff)) 63 #define SDT_SAVE (0x9de3a000 | (-SA(MINFRAME) & SDT_SIMM13_MASK)) 64 #define SDT_RET 0x81c7e008 65 #define SDT_RESTORE 0x81e80000 66 67 #define SDT_OP_SETHI 0x1000000 68 #define SDT_OP_OR 0x80100000 69 70 #define SDT_FMT2_RD_SHIFT 25 71 #define SDT_IMM22_SHIFT 10 72 #define SDT_IMM22_MASK 0x3fffff 73 #define SDT_IMM10_MASK 0x3ff 74 75 #define SDT_FMT3_RD_SHIFT 25 76 #define SDT_FMT3_RS1_SHIFT 14 77 #define SDT_FMT3_RS2_SHIFT 0 78 #define SDT_FMT3_IMM (1 << 13) 79 80 #define SDT_MOV(rs, rd) \ 81 (SDT_OP_OR | (SDT_REG_G0 << SDT_FMT3_RS1_SHIFT) | \ 82 ((rs) << SDT_FMT3_RS2_SHIFT) | ((rd) << SDT_FMT3_RD_SHIFT)) 83 84 #define SDT_ORLO(rs, val, rd) \ 85 (SDT_OP_OR | ((rs) << SDT_FMT3_RS1_SHIFT) | \ 86 ((rd) << SDT_FMT3_RD_SHIFT) | SDT_FMT3_IMM | ((val) & SDT_IMM10_MASK)) 87 88 #define SDT_ORSIMM13(rs, val, rd) \ 89 (SDT_OP_OR | ((rs) << SDT_FMT3_RS1_SHIFT) | \ 90 ((rd) << SDT_FMT3_RD_SHIFT) | SDT_FMT3_IMM | ((val) & SDT_SIMM13_MASK)) 91 92 #define SDT_SETHI(val, reg) \ 93 (SDT_OP_SETHI | (reg << SDT_FMT2_RD_SHIFT) | \ 94 ((val >> SDT_IMM22_SHIFT) & SDT_IMM22_MASK)) 95 96 #define SDT_ENTRY_SIZE (11 * sizeof (uint32_t)) 97 98 static void 99 sdt_initialize(sdt_probe_t *sdp, uint32_t **trampoline) 100 { 101 uint32_t *instr = *trampoline; 102 103 *instr++ = SDT_SAVE; 104 105 if (sdp->sdp_id > (uint32_t)SDT_SIMM13_MAX) { 106 *instr++ = SDT_SETHI(sdp->sdp_id, SDT_REG_O0); 107 *instr++ = SDT_ORLO(SDT_REG_O0, sdp->sdp_id, SDT_REG_O0); 108 } else { 109 *instr++ = SDT_ORSIMM13(SDT_REG_G0, sdp->sdp_id, SDT_REG_O0); 110 } 111 112 *instr++ = SDT_MOV(SDT_REG_I0, SDT_REG_O1); 113 *instr++ = SDT_MOV(SDT_REG_I1, SDT_REG_O2); 114 *instr++ = SDT_MOV(SDT_REG_I2, SDT_REG_O3); 115 *instr++ = SDT_MOV(SDT_REG_I3, SDT_REG_O4); 116 *instr = SDT_CALL(instr, dtrace_probe); 117 instr++; 118 *instr++ = SDT_MOV(SDT_REG_I4, SDT_REG_O5); 119 120 *instr++ = SDT_RET; 121 *instr++ = SDT_RESTORE; 122 *trampoline = instr; 123 } 124 125 /*ARGSUSED*/ 126 static void 127 sdt_provide_module(void *arg, struct modctl *ctl) 128 { 129 struct module *mp = ctl->mod_mp; 130 char *modname = ctl->mod_modname; 131 int primary, nprobes = 0; 132 sdt_probedesc_t *sdpd; 133 sdt_probe_t *sdp, *old; 134 uint32_t *tab; 135 sdt_provider_t *prov; 136 int len; 137 138 /* 139 * One for all, and all for one: if we haven't yet registered all of 140 * our providers, we'll refuse to provide anything. 141 */ 142 for (prov = sdt_providers; prov->sdtp_name != NULL; prov++) { 143 if (prov->sdtp_id == DTRACE_PROVNONE) 144 return; 145 } 146 147 if (mp->sdt_nprobes != 0 || (sdpd = mp->sdt_probes) == NULL) 148 return; 149 150 kobj_textwin_alloc(mp); 151 152 /* 153 * Hack to identify unix/genunix/krtld. 154 */ 155 primary = vmem_contains(heap_arena, (void *)ctl, 156 sizeof (struct modctl)) == 0; 157 158 /* 159 * If there hasn't been an sdt table allocated, we'll do so now. 160 */ 161 if (mp->sdt_tab == NULL) { 162 for (; sdpd != NULL; sdpd = sdpd->sdpd_next) { 163 nprobes++; 164 } 165 166 /* 167 * We could (should?) determine precisely the size of the 168 * table -- but a reasonable maximum will suffice. 169 */ 170 mp->sdt_size = nprobes * SDT_ENTRY_SIZE; 171 mp->sdt_tab = kobj_texthole_alloc(mp->text, mp->sdt_size); 172 173 if (mp->sdt_tab == NULL) { 174 cmn_err(CE_WARN, "couldn't allocate SDT table " 175 "for module %s", modname); 176 return; 177 } 178 } 179 180 tab = (uint32_t *)mp->sdt_tab; 181 182 for (sdpd = mp->sdt_probes; sdpd != NULL; sdpd = sdpd->sdpd_next) { 183 char *name = sdpd->sdpd_name, *func, *nname; 184 int i, j; 185 sdt_provider_t *prov; 186 ulong_t offs; 187 dtrace_id_t id; 188 189 for (prov = sdt_providers; prov->sdtp_prefix != NULL; prov++) { 190 char *prefix = prov->sdtp_prefix; 191 192 if (strncmp(name, prefix, strlen(prefix)) == 0) { 193 name += strlen(prefix); 194 break; 195 } 196 } 197 198 nname = kmem_alloc(len = strlen(name) + 1, KM_SLEEP); 199 200 for (i = 0, j = 0; name[j] != '\0'; i++) { 201 if (name[j] == '_' && name[j + 1] == '_') { 202 nname[i] = '-'; 203 j += 2; 204 } else { 205 nname[i] = name[j++]; 206 } 207 } 208 209 nname[i] = '\0'; 210 211 sdp = kmem_zalloc(sizeof (sdt_probe_t), KM_SLEEP); 212 sdp->sdp_loadcnt = ctl->mod_loadcnt; 213 sdp->sdp_primary = primary; 214 sdp->sdp_ctl = ctl; 215 sdp->sdp_name = nname; 216 sdp->sdp_namelen = len; 217 sdp->sdp_provider = prov; 218 219 func = kobj_searchsym(mp, sdpd->sdpd_offset + 220 (uintptr_t)mp->text, &offs); 221 222 if (func == NULL) 223 func = "<unknown>"; 224 225 /* 226 * We have our provider. Now create the probe. 227 */ 228 if ((id = dtrace_probe_lookup(prov->sdtp_id, modname, 229 func, nname)) != DTRACE_IDNONE) { 230 old = dtrace_probe_arg(prov->sdtp_id, id); 231 ASSERT(old != NULL); 232 233 sdp->sdp_next = old->sdp_next; 234 sdp->sdp_id = id; 235 old->sdp_next = sdp; 236 } else { 237 sdp->sdp_id = dtrace_probe_create(prov->sdtp_id, 238 modname, func, nname, 1, sdp); 239 240 mp->sdt_nprobes++; 241 } 242 243 sdp->sdp_patchval = SDT_CALL((uintptr_t)mp->text + 244 sdpd->sdpd_offset, tab); 245 sdp->sdp_patchpoint = (uint32_t *)((uintptr_t)mp->textwin + 246 sdpd->sdpd_offset); 247 sdp->sdp_savedval = *sdp->sdp_patchpoint; 248 sdt_initialize(sdp, &tab); 249 } 250 } 251 252 /*ARGSUSED*/ 253 static void 254 sdt_destroy(void *arg, dtrace_id_t id, void *parg) 255 { 256 sdt_probe_t *sdp = parg, *old; 257 struct modctl *ctl = sdp->sdp_ctl; 258 259 if (ctl != NULL && ctl->mod_loadcnt == sdp->sdp_loadcnt) { 260 if ((ctl->mod_loadcnt == sdp->sdp_loadcnt && 261 ctl->mod_loaded) || sdp->sdp_primary) { 262 ((struct module *)(ctl->mod_mp))->sdt_nprobes--; 263 } 264 } 265 266 while (sdp != NULL) { 267 old = sdp; 268 kmem_free(sdp->sdp_name, sdp->sdp_namelen); 269 sdp = sdp->sdp_next; 270 kmem_free(old, sizeof (sdt_probe_t)); 271 } 272 } 273 274 /*ARGSUSED*/ 275 static int 276 sdt_enable(void *arg, dtrace_id_t id, void *parg) 277 { 278 sdt_probe_t *sdp = parg; 279 struct modctl *ctl = sdp->sdp_ctl; 280 281 ctl->mod_nenabled++; 282 283 /* 284 * If this module has disappeared since we discovered its probes, 285 * refuse to enable it. 286 */ 287 if (!sdp->sdp_primary && !ctl->mod_loaded) { 288 if (sdt_verbose) { 289 cmn_err(CE_NOTE, "sdt is failing for probe %s " 290 "(module %s unloaded)", 291 sdp->sdp_name, ctl->mod_modname); 292 } 293 goto err; 294 } 295 296 /* 297 * Now check that our modctl has the expected load count. If it 298 * doesn't, this module must have been unloaded and reloaded -- and 299 * we're not going to touch it. 300 */ 301 if (ctl->mod_loadcnt != sdp->sdp_loadcnt) { 302 if (sdt_verbose) { 303 cmn_err(CE_NOTE, "sdt is failing for probe %s " 304 "(module %s reloaded)", 305 sdp->sdp_name, ctl->mod_modname); 306 } 307 goto err; 308 } 309 310 while (sdp != NULL) { 311 *sdp->sdp_patchpoint = sdp->sdp_patchval; 312 sdp = sdp->sdp_next; 313 } 314 315 err: 316 return (0); 317 } 318 319 /*ARGSUSED*/ 320 static void 321 sdt_disable(void *arg, dtrace_id_t id, void *parg) 322 { 323 sdt_probe_t *sdp = parg; 324 struct modctl *ctl = sdp->sdp_ctl; 325 326 ASSERT(ctl->mod_nenabled > 0); 327 ctl->mod_nenabled--; 328 329 if ((!sdp->sdp_primary && !ctl->mod_loaded) || 330 (ctl->mod_loadcnt != sdp->sdp_loadcnt)) 331 goto err; 332 333 while (sdp != NULL) { 334 *sdp->sdp_patchpoint = sdp->sdp_savedval; 335 sdp = sdp->sdp_next; 336 } 337 338 err: 339 ; 340 } 341 342 static dtrace_pops_t sdt_pops = { 343 NULL, 344 sdt_provide_module, 345 sdt_enable, 346 sdt_disable, 347 NULL, 348 NULL, 349 sdt_getargdesc, 350 NULL, 351 NULL, 352 sdt_destroy 353 }; 354 355 static int 356 sdt_attach(dev_info_t *devi, ddi_attach_cmd_t cmd) 357 { 358 sdt_provider_t *prov; 359 360 switch (cmd) { 361 case DDI_ATTACH: 362 break; 363 case DDI_RESUME: 364 return (DDI_SUCCESS); 365 default: 366 return (DDI_FAILURE); 367 } 368 369 if (ddi_create_minor_node(devi, "sdt", S_IFCHR, 0, 370 DDI_PSEUDO, NULL) == DDI_FAILURE) { 371 ddi_remove_minor_node(devi, NULL); 372 return (DDI_FAILURE); 373 } 374 375 ddi_report_dev(devi); 376 sdt_devi = devi; 377 378 for (prov = sdt_providers; prov->sdtp_name != NULL; prov++) { 379 uint32_t priv; 380 381 if (prov->sdtp_priv == DTRACE_PRIV_NONE) { 382 priv = DTRACE_PRIV_KERNEL; 383 sdt_pops.dtps_mode = NULL; 384 } else { 385 priv = prov->sdtp_priv; 386 ASSERT(priv == DTRACE_PRIV_USER); 387 sdt_pops.dtps_mode = sdt_mode; 388 } 389 390 if (dtrace_register(prov->sdtp_name, prov->sdtp_attr, 391 priv, NULL, &sdt_pops, prov, &prov->sdtp_id) != 0) { 392 cmn_err(CE_WARN, "failed to register sdt provider %s", 393 prov->sdtp_name); 394 } 395 } 396 397 return (DDI_SUCCESS); 398 } 399 400 static int 401 sdt_detach(dev_info_t *devi, ddi_detach_cmd_t cmd) 402 { 403 sdt_provider_t *prov; 404 405 switch (cmd) { 406 case DDI_DETACH: 407 break; 408 case DDI_SUSPEND: 409 return (DDI_SUCCESS); 410 default: 411 return (DDI_FAILURE); 412 } 413 414 for (prov = sdt_providers; prov->sdtp_name != NULL; prov++) { 415 if (prov->sdtp_id != DTRACE_PROVNONE) { 416 if (dtrace_unregister(prov->sdtp_id) != 0) 417 return (DDI_FAILURE); 418 prov->sdtp_id = DTRACE_PROVNONE; 419 } 420 } 421 422 ddi_remove_minor_node(devi, NULL); 423 return (DDI_SUCCESS); 424 } 425 426 /*ARGSUSED*/ 427 static int 428 sdt_info(dev_info_t *dip, ddi_info_cmd_t infocmd, void *arg, void **result) 429 { 430 int error; 431 432 switch (infocmd) { 433 case DDI_INFO_DEVT2DEVINFO: 434 *result = (void *)sdt_devi; 435 error = DDI_SUCCESS; 436 break; 437 case DDI_INFO_DEVT2INSTANCE: 438 *result = (void *)0; 439 error = DDI_SUCCESS; 440 break; 441 default: 442 error = DDI_FAILURE; 443 } 444 return (error); 445 } 446 447 /*ARGSUSED*/ 448 static int 449 sdt_open(dev_t *devp, int flag, int otyp, cred_t *cred_p) 450 { 451 return (0); 452 } 453 454 static struct cb_ops sdt_cb_ops = { 455 sdt_open, /* open */ 456 nodev, /* close */ 457 nulldev, /* strategy */ 458 nulldev, /* print */ 459 nodev, /* dump */ 460 nodev, /* read */ 461 nodev, /* write */ 462 nodev, /* ioctl */ 463 nodev, /* devmap */ 464 nodev, /* mmap */ 465 nodev, /* segmap */ 466 nochpoll, /* poll */ 467 ddi_prop_op, /* cb_prop_op */ 468 0, /* streamtab */ 469 D_NEW | D_MP /* Driver compatibility flag */ 470 }; 471 472 static struct dev_ops sdt_ops = { 473 DEVO_REV, /* devo_rev, */ 474 0, /* refcnt */ 475 sdt_info, /* get_dev_info */ 476 nulldev, /* identify */ 477 nulldev, /* probe */ 478 sdt_attach, /* attach */ 479 sdt_detach, /* detach */ 480 nodev, /* reset */ 481 &sdt_cb_ops, /* driver operations */ 482 NULL, /* bus operations */ 483 nodev, /* dev power */ 484 ddi_quiesce_not_needed, /* quiesce */ 485 }; 486 487 /* 488 * Module linkage information for the kernel. 489 */ 490 static struct modldrv modldrv = { 491 &mod_driverops, /* module type (this is a pseudo driver) */ 492 "Statically Defined Tracing", /* name of module */ 493 &sdt_ops, /* driver ops */ 494 }; 495 496 static struct modlinkage modlinkage = { 497 MODREV_1, 498 (void *)&modldrv, 499 NULL 500 }; 501 502 int 503 _init(void) 504 { 505 return (mod_install(&modlinkage)); 506 } 507 508 int 509 _info(struct modinfo *modinfop) 510 { 511 return (mod_info(&modlinkage, modinfop)); 512 } 513 514 int 515 _fini(void) 516 { 517 return (mod_remove(&modlinkage)); 518 } 519