1 /*- 2 * Copyright (c) 2003-2008 Joseph Koshy 3 * Copyright (c) 2007 The FreeBSD Foundation 4 * All rights reserved. 5 * 6 * Portions of this software were developed by A. Joseph Koshy under 7 * sponsorship from the FreeBSD Foundation and Google, Inc. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 * 30 */ 31 32 #include <sys/cdefs.h> 33 __FBSDID("$FreeBSD$"); 34 35 #include <sys/param.h> 36 #include <sys/eventhandler.h> 37 #include <sys/jail.h> 38 #include <sys/kernel.h> 39 #include <sys/kthread.h> 40 #include <sys/limits.h> 41 #include <sys/lock.h> 42 #include <sys/malloc.h> 43 #include <sys/module.h> 44 #include <sys/mutex.h> 45 #include <sys/pmc.h> 46 #include <sys/pmckern.h> 47 #include <sys/pmclog.h> 48 #include <sys/priv.h> 49 #include <sys/proc.h> 50 #include <sys/queue.h> 51 #include <sys/resourcevar.h> 52 #include <sys/sched.h> 53 #include <sys/signalvar.h> 54 #include <sys/smp.h> 55 #include <sys/sx.h> 56 #include <sys/sysctl.h> 57 #include <sys/sysent.h> 58 #include <sys/systm.h> 59 #include <sys/vnode.h> 60 61 #include <sys/linker.h> /* needs to be after <sys/malloc.h> */ 62 63 #include <machine/atomic.h> 64 #include <machine/md_var.h> 65 66 /* 67 * Types 68 */ 69 70 enum pmc_flags { 71 PMC_FLAG_NONE = 0x00, /* do nothing */ 72 PMC_FLAG_REMOVE = 0x01, /* atomically remove entry from hash */ 73 PMC_FLAG_ALLOCATE = 0x02, /* add entry to hash if not found */ 74 }; 75 76 /* 77 * The offset in sysent where the syscall is allocated. 78 */ 79 80 static int pmc_syscall_num = NO_SYSCALL; 81 struct pmc_cpu **pmc_pcpu; /* per-cpu state */ 82 pmc_value_t *pmc_pcpu_saved; /* saved PMC values: CSW handling */ 83 84 #define PMC_PCPU_SAVED(C,R) pmc_pcpu_saved[(R) + md->pmd_npmc*(C)] 85 86 struct mtx_pool *pmc_mtxpool; 87 static int *pmc_pmcdisp; /* PMC row dispositions */ 88 89 #define PMC_ROW_DISP_IS_FREE(R) (pmc_pmcdisp[(R)] == 0) 90 #define PMC_ROW_DISP_IS_THREAD(R) (pmc_pmcdisp[(R)] > 0) 91 #define PMC_ROW_DISP_IS_STANDALONE(R) (pmc_pmcdisp[(R)] < 0) 92 93 #define PMC_MARK_ROW_FREE(R) do { \ 94 pmc_pmcdisp[(R)] = 0; \ 95 } while (0) 96 97 #define PMC_MARK_ROW_STANDALONE(R) do { \ 98 KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \ 99 __LINE__)); \ 100 atomic_add_int(&pmc_pmcdisp[(R)], -1); \ 101 KASSERT(pmc_pmcdisp[(R)] >= (-pmc_cpu_max_active()), \ 102 ("[pmc,%d] row disposition error", __LINE__)); \ 103 } while (0) 104 105 #define PMC_UNMARK_ROW_STANDALONE(R) do { \ 106 atomic_add_int(&pmc_pmcdisp[(R)], 1); \ 107 KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \ 108 __LINE__)); \ 109 } while (0) 110 111 #define PMC_MARK_ROW_THREAD(R) do { \ 112 KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \ 113 __LINE__)); \ 114 atomic_add_int(&pmc_pmcdisp[(R)], 1); \ 115 } while (0) 116 117 #define PMC_UNMARK_ROW_THREAD(R) do { \ 118 atomic_add_int(&pmc_pmcdisp[(R)], -1); \ 119 KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \ 120 __LINE__)); \ 121 } while (0) 122 123 124 /* various event handlers */ 125 static eventhandler_tag pmc_exit_tag, pmc_fork_tag; 126 127 /* Module statistics */ 128 struct pmc_op_getdriverstats pmc_stats; 129 130 /* Machine/processor dependent operations */ 131 static struct pmc_mdep *md; 132 133 /* 134 * Hash tables mapping owner processes and target threads to PMCs. 135 */ 136 137 struct mtx pmc_processhash_mtx; /* spin mutex */ 138 static u_long pmc_processhashmask; 139 static LIST_HEAD(pmc_processhash, pmc_process) *pmc_processhash; 140 141 /* 142 * Hash table of PMC owner descriptors. This table is protected by 143 * the shared PMC "sx" lock. 144 */ 145 146 static u_long pmc_ownerhashmask; 147 static LIST_HEAD(pmc_ownerhash, pmc_owner) *pmc_ownerhash; 148 149 /* 150 * List of PMC owners with system-wide sampling PMCs. 151 */ 152 153 static LIST_HEAD(, pmc_owner) pmc_ss_owners; 154 155 156 /* 157 * A map of row indices to classdep structures. 158 */ 159 static struct pmc_classdep **pmc_rowindex_to_classdep; 160 161 /* 162 * Prototypes 163 */ 164 165 #ifdef DEBUG 166 static int pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS); 167 static int pmc_debugflags_parse(char *newstr, char *fence); 168 #endif 169 170 static int load(struct module *module, int cmd, void *arg); 171 static int pmc_attach_process(struct proc *p, struct pmc *pm); 172 static struct pmc *pmc_allocate_pmc_descriptor(void); 173 static struct pmc_owner *pmc_allocate_owner_descriptor(struct proc *p); 174 static int pmc_attach_one_process(struct proc *p, struct pmc *pm); 175 static int pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, 176 int cpu); 177 static int pmc_can_attach(struct pmc *pm, struct proc *p); 178 static void pmc_capture_user_callchain(int cpu, struct trapframe *tf); 179 static void pmc_cleanup(void); 180 static int pmc_detach_process(struct proc *p, struct pmc *pm); 181 static int pmc_detach_one_process(struct proc *p, struct pmc *pm, 182 int flags); 183 static void pmc_destroy_owner_descriptor(struct pmc_owner *po); 184 static struct pmc_owner *pmc_find_owner_descriptor(struct proc *p); 185 static int pmc_find_pmc(pmc_id_t pmcid, struct pmc **pm); 186 static struct pmc *pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, 187 pmc_id_t pmc); 188 static struct pmc_process *pmc_find_process_descriptor(struct proc *p, 189 uint32_t mode); 190 static void pmc_force_context_switch(void); 191 static void pmc_link_target_process(struct pmc *pm, 192 struct pmc_process *pp); 193 static void pmc_log_all_process_mappings(struct pmc_owner *po); 194 static void pmc_log_kernel_mappings(struct pmc *pm); 195 static void pmc_log_process_mappings(struct pmc_owner *po, struct proc *p); 196 static void pmc_maybe_remove_owner(struct pmc_owner *po); 197 static void pmc_process_csw_in(struct thread *td); 198 static void pmc_process_csw_out(struct thread *td); 199 static void pmc_process_exit(void *arg, struct proc *p); 200 static void pmc_process_fork(void *arg, struct proc *p1, 201 struct proc *p2, int n); 202 static void pmc_process_samples(int cpu); 203 static void pmc_release_pmc_descriptor(struct pmc *pmc); 204 static void pmc_remove_owner(struct pmc_owner *po); 205 static void pmc_remove_process_descriptor(struct pmc_process *pp); 206 static void pmc_restore_cpu_binding(struct pmc_binding *pb); 207 static void pmc_save_cpu_binding(struct pmc_binding *pb); 208 static void pmc_select_cpu(int cpu); 209 static int pmc_start(struct pmc *pm); 210 static int pmc_stop(struct pmc *pm); 211 static int pmc_syscall_handler(struct thread *td, void *syscall_args); 212 static void pmc_unlink_target_process(struct pmc *pmc, 213 struct pmc_process *pp); 214 215 /* 216 * Kernel tunables and sysctl(8) interface. 217 */ 218 219 SYSCTL_NODE(_kern, OID_AUTO, hwpmc, CTLFLAG_RW, 0, "HWPMC parameters"); 220 221 static int pmc_callchaindepth = PMC_CALLCHAIN_DEPTH; 222 TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "callchaindepth", &pmc_callchaindepth); 223 SYSCTL_INT(_kern_hwpmc, OID_AUTO, callchaindepth, CTLFLAG_TUN|CTLFLAG_RD, 224 &pmc_callchaindepth, 0, "depth of call chain records"); 225 226 #ifdef DEBUG 227 struct pmc_debugflags pmc_debugflags = PMC_DEBUG_DEFAULT_FLAGS; 228 char pmc_debugstr[PMC_DEBUG_STRSIZE]; 229 TUNABLE_STR(PMC_SYSCTL_NAME_PREFIX "debugflags", pmc_debugstr, 230 sizeof(pmc_debugstr)); 231 SYSCTL_PROC(_kern_hwpmc, OID_AUTO, debugflags, 232 CTLTYPE_STRING|CTLFLAG_RW|CTLFLAG_TUN, 233 0, 0, pmc_debugflags_sysctl_handler, "A", "debug flags"); 234 #endif 235 236 /* 237 * kern.hwpmc.hashrows -- determines the number of rows in the 238 * of the hash table used to look up threads 239 */ 240 241 static int pmc_hashsize = PMC_HASH_SIZE; 242 TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "hashsize", &pmc_hashsize); 243 SYSCTL_INT(_kern_hwpmc, OID_AUTO, hashsize, CTLFLAG_TUN|CTLFLAG_RD, 244 &pmc_hashsize, 0, "rows in hash tables"); 245 246 /* 247 * kern.hwpmc.nsamples --- number of PC samples/callchain stacks per CPU 248 */ 249 250 static int pmc_nsamples = PMC_NSAMPLES; 251 TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "nsamples", &pmc_nsamples); 252 SYSCTL_INT(_kern_hwpmc, OID_AUTO, nsamples, CTLFLAG_TUN|CTLFLAG_RD, 253 &pmc_nsamples, 0, "number of PC samples per CPU"); 254 255 256 /* 257 * kern.hwpmc.mtxpoolsize -- number of mutexes in the mutex pool. 258 */ 259 260 static int pmc_mtxpool_size = PMC_MTXPOOL_SIZE; 261 TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "mtxpoolsize", &pmc_mtxpool_size); 262 SYSCTL_INT(_kern_hwpmc, OID_AUTO, mtxpoolsize, CTLFLAG_TUN|CTLFLAG_RD, 263 &pmc_mtxpool_size, 0, "size of spin mutex pool"); 264 265 266 /* 267 * security.bsd.unprivileged_syspmcs -- allow non-root processes to 268 * allocate system-wide PMCs. 269 * 270 * Allowing unprivileged processes to allocate system PMCs is convenient 271 * if system-wide measurements need to be taken concurrently with other 272 * per-process measurements. This feature is turned off by default. 273 */ 274 275 static int pmc_unprivileged_syspmcs = 0; 276 TUNABLE_INT("security.bsd.unprivileged_syspmcs", &pmc_unprivileged_syspmcs); 277 SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_syspmcs, CTLFLAG_RW, 278 &pmc_unprivileged_syspmcs, 0, 279 "allow unprivileged process to allocate system PMCs"); 280 281 /* 282 * Hash function. Discard the lower 2 bits of the pointer since 283 * these are always zero for our uses. The hash multiplier is 284 * round((2^LONG_BIT) * ((sqrt(5)-1)/2)). 285 */ 286 287 #if LONG_BIT == 64 288 #define _PMC_HM 11400714819323198486u 289 #elif LONG_BIT == 32 290 #define _PMC_HM 2654435769u 291 #else 292 #error Must know the size of 'long' to compile 293 #endif 294 295 #define PMC_HASH_PTR(P,M) ((((unsigned long) (P) >> 2) * _PMC_HM) & (M)) 296 297 /* 298 * Syscall structures 299 */ 300 301 /* The `sysent' for the new syscall */ 302 static struct sysent pmc_sysent = { 303 2, /* sy_narg */ 304 pmc_syscall_handler /* sy_call */ 305 }; 306 307 static struct syscall_module_data pmc_syscall_mod = { 308 load, 309 NULL, 310 &pmc_syscall_num, 311 &pmc_sysent, 312 { 0, NULL } 313 }; 314 315 static moduledata_t pmc_mod = { 316 PMC_MODULE_NAME, 317 syscall_module_handler, 318 &pmc_syscall_mod 319 }; 320 321 DECLARE_MODULE(pmc, pmc_mod, SI_SUB_SMP, SI_ORDER_ANY); 322 MODULE_VERSION(pmc, PMC_VERSION); 323 324 #ifdef DEBUG 325 enum pmc_dbgparse_state { 326 PMCDS_WS, /* in whitespace */ 327 PMCDS_MAJOR, /* seen a major keyword */ 328 PMCDS_MINOR 329 }; 330 331 static int 332 pmc_debugflags_parse(char *newstr, char *fence) 333 { 334 char c, *p, *q; 335 struct pmc_debugflags *tmpflags; 336 int error, found, *newbits, tmp; 337 size_t kwlen; 338 339 tmpflags = malloc(sizeof(*tmpflags), M_PMC, M_WAITOK|M_ZERO); 340 341 p = newstr; 342 error = 0; 343 344 for (; p < fence && (c = *p); p++) { 345 346 /* skip white space */ 347 if (c == ' ' || c == '\t') 348 continue; 349 350 /* look for a keyword followed by "=" */ 351 for (q = p; p < fence && (c = *p) && c != '='; p++) 352 ; 353 if (c != '=') { 354 error = EINVAL; 355 goto done; 356 } 357 358 kwlen = p - q; 359 newbits = NULL; 360 361 /* lookup flag group name */ 362 #define DBG_SET_FLAG_MAJ(S,F) \ 363 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \ 364 newbits = &tmpflags->pdb_ ## F; 365 366 DBG_SET_FLAG_MAJ("cpu", CPU); 367 DBG_SET_FLAG_MAJ("csw", CSW); 368 DBG_SET_FLAG_MAJ("logging", LOG); 369 DBG_SET_FLAG_MAJ("module", MOD); 370 DBG_SET_FLAG_MAJ("md", MDP); 371 DBG_SET_FLAG_MAJ("owner", OWN); 372 DBG_SET_FLAG_MAJ("pmc", PMC); 373 DBG_SET_FLAG_MAJ("process", PRC); 374 DBG_SET_FLAG_MAJ("sampling", SAM); 375 376 if (newbits == NULL) { 377 error = EINVAL; 378 goto done; 379 } 380 381 p++; /* skip the '=' */ 382 383 /* Now parse the individual flags */ 384 tmp = 0; 385 newflag: 386 for (q = p; p < fence && (c = *p); p++) 387 if (c == ' ' || c == '\t' || c == ',') 388 break; 389 390 /* p == fence or c == ws or c == "," or c == 0 */ 391 392 if ((kwlen = p - q) == 0) { 393 *newbits = tmp; 394 continue; 395 } 396 397 found = 0; 398 #define DBG_SET_FLAG_MIN(S,F) \ 399 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \ 400 tmp |= found = (1 << PMC_DEBUG_MIN_ ## F) 401 402 /* a '*' denotes all possible flags in the group */ 403 if (kwlen == 1 && *q == '*') 404 tmp = found = ~0; 405 /* look for individual flag names */ 406 DBG_SET_FLAG_MIN("allocaterow", ALR); 407 DBG_SET_FLAG_MIN("allocate", ALL); 408 DBG_SET_FLAG_MIN("attach", ATT); 409 DBG_SET_FLAG_MIN("bind", BND); 410 DBG_SET_FLAG_MIN("config", CFG); 411 DBG_SET_FLAG_MIN("exec", EXC); 412 DBG_SET_FLAG_MIN("exit", EXT); 413 DBG_SET_FLAG_MIN("find", FND); 414 DBG_SET_FLAG_MIN("flush", FLS); 415 DBG_SET_FLAG_MIN("fork", FRK); 416 DBG_SET_FLAG_MIN("getbuf", GTB); 417 DBG_SET_FLAG_MIN("hook", PMH); 418 DBG_SET_FLAG_MIN("init", INI); 419 DBG_SET_FLAG_MIN("intr", INT); 420 DBG_SET_FLAG_MIN("linktarget", TLK); 421 DBG_SET_FLAG_MIN("mayberemove", OMR); 422 DBG_SET_FLAG_MIN("ops", OPS); 423 DBG_SET_FLAG_MIN("read", REA); 424 DBG_SET_FLAG_MIN("register", REG); 425 DBG_SET_FLAG_MIN("release", REL); 426 DBG_SET_FLAG_MIN("remove", ORM); 427 DBG_SET_FLAG_MIN("sample", SAM); 428 DBG_SET_FLAG_MIN("scheduleio", SIO); 429 DBG_SET_FLAG_MIN("select", SEL); 430 DBG_SET_FLAG_MIN("signal", SIG); 431 DBG_SET_FLAG_MIN("swi", SWI); 432 DBG_SET_FLAG_MIN("swo", SWO); 433 DBG_SET_FLAG_MIN("start", STA); 434 DBG_SET_FLAG_MIN("stop", STO); 435 DBG_SET_FLAG_MIN("syscall", PMS); 436 DBG_SET_FLAG_MIN("unlinktarget", TUL); 437 DBG_SET_FLAG_MIN("write", WRI); 438 if (found == 0) { 439 /* unrecognized flag name */ 440 error = EINVAL; 441 goto done; 442 } 443 444 if (c == 0 || c == ' ' || c == '\t') { /* end of flag group */ 445 *newbits = tmp; 446 continue; 447 } 448 449 p++; 450 goto newflag; 451 } 452 453 /* save the new flag set */ 454 bcopy(tmpflags, &pmc_debugflags, sizeof(pmc_debugflags)); 455 456 done: 457 free(tmpflags, M_PMC); 458 return error; 459 } 460 461 static int 462 pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS) 463 { 464 char *fence, *newstr; 465 int error; 466 unsigned int n; 467 468 (void) arg1; (void) arg2; /* unused parameters */ 469 470 n = sizeof(pmc_debugstr); 471 newstr = malloc(n, M_PMC, M_WAITOK|M_ZERO); 472 (void) strlcpy(newstr, pmc_debugstr, n); 473 474 error = sysctl_handle_string(oidp, newstr, n, req); 475 476 /* if there is a new string, parse and copy it */ 477 if (error == 0 && req->newptr != NULL) { 478 fence = newstr + (n < req->newlen ? n : req->newlen + 1); 479 if ((error = pmc_debugflags_parse(newstr, fence)) == 0) 480 (void) strlcpy(pmc_debugstr, newstr, 481 sizeof(pmc_debugstr)); 482 } 483 484 free(newstr, M_PMC); 485 486 return error; 487 } 488 #endif 489 490 /* 491 * Map a row index to a classdep structure and return the adjusted row 492 * index for the PMC class index. 493 */ 494 static struct pmc_classdep * 495 pmc_ri_to_classdep(struct pmc_mdep *md, int ri, int *adjri) 496 { 497 struct pmc_classdep *pcd; 498 499 (void) md; 500 501 KASSERT(ri >= 0 && ri < md->pmd_npmc, 502 ("[pmc,%d] illegal row-index %d", __LINE__, ri)); 503 504 pcd = pmc_rowindex_to_classdep[ri]; 505 506 KASSERT(pcd != NULL, 507 ("[pmc,%d] ri %d null pcd", __LINE__, ri)); 508 509 *adjri = ri - pcd->pcd_ri; 510 511 KASSERT(*adjri >= 0 && *adjri < pcd->pcd_num, 512 ("[pmc,%d] adjusted row-index %d", __LINE__, *adjri)); 513 514 return (pcd); 515 } 516 517 /* 518 * Concurrency Control 519 * 520 * The driver manages the following data structures: 521 * 522 * - target process descriptors, one per target process 523 * - owner process descriptors (and attached lists), one per owner process 524 * - lookup hash tables for owner and target processes 525 * - PMC descriptors (and attached lists) 526 * - per-cpu hardware state 527 * - the 'hook' variable through which the kernel calls into 528 * this module 529 * - the machine hardware state (managed by the MD layer) 530 * 531 * These data structures are accessed from: 532 * 533 * - thread context-switch code 534 * - interrupt handlers (possibly on multiple cpus) 535 * - kernel threads on multiple cpus running on behalf of user 536 * processes doing system calls 537 * - this driver's private kernel threads 538 * 539 * = Locks and Locking strategy = 540 * 541 * The driver uses four locking strategies for its operation: 542 * 543 * - The global SX lock "pmc_sx" is used to protect internal 544 * data structures. 545 * 546 * Calls into the module by syscall() start with this lock being 547 * held in exclusive mode. Depending on the requested operation, 548 * the lock may be downgraded to 'shared' mode to allow more 549 * concurrent readers into the module. Calls into the module from 550 * other parts of the kernel acquire the lock in shared mode. 551 * 552 * This SX lock is held in exclusive mode for any operations that 553 * modify the linkages between the driver's internal data structures. 554 * 555 * The 'pmc_hook' function pointer is also protected by this lock. 556 * It is only examined with the sx lock held in exclusive mode. The 557 * kernel module is allowed to be unloaded only with the sx lock held 558 * in exclusive mode. In normal syscall handling, after acquiring the 559 * pmc_sx lock we first check that 'pmc_hook' is non-null before 560 * proceeding. This prevents races between the thread unloading the module 561 * and other threads seeking to use the module. 562 * 563 * - Lookups of target process structures and owner process structures 564 * cannot use the global "pmc_sx" SX lock because these lookups need 565 * to happen during context switches and in other critical sections 566 * where sleeping is not allowed. We protect these lookup tables 567 * with their own private spin-mutexes, "pmc_processhash_mtx" and 568 * "pmc_ownerhash_mtx". 569 * 570 * - Interrupt handlers work in a lock free manner. At interrupt 571 * time, handlers look at the PMC pointer (phw->phw_pmc) configured 572 * when the PMC was started. If this pointer is NULL, the interrupt 573 * is ignored after updating driver statistics. We ensure that this 574 * pointer is set (using an atomic operation if necessary) before the 575 * PMC hardware is started. Conversely, this pointer is unset atomically 576 * only after the PMC hardware is stopped. 577 * 578 * We ensure that everything needed for the operation of an 579 * interrupt handler is available without it needing to acquire any 580 * locks. We also ensure that a PMC's software state is destroyed only 581 * after the PMC is taken off hardware (on all CPUs). 582 * 583 * - Context-switch handling with process-private PMCs needs more 584 * care. 585 * 586 * A given process may be the target of multiple PMCs. For example, 587 * PMCATTACH and PMCDETACH may be requested by a process on one CPU 588 * while the target process is running on another. A PMC could also 589 * be getting released because its owner is exiting. We tackle 590 * these situations in the following manner: 591 * 592 * - each target process structure 'pmc_process' has an array 593 * of 'struct pmc *' pointers, one for each hardware PMC. 594 * 595 * - At context switch IN time, each "target" PMC in RUNNING state 596 * gets started on hardware and a pointer to each PMC is copied into 597 * the per-cpu phw array. The 'runcount' for the PMC is 598 * incremented. 599 * 600 * - At context switch OUT time, all process-virtual PMCs are stopped 601 * on hardware. The saved value is added to the PMCs value field 602 * only if the PMC is in a non-deleted state (the PMCs state could 603 * have changed during the current time slice). 604 * 605 * Note that since in-between a switch IN on a processor and a switch 606 * OUT, the PMC could have been released on another CPU. Therefore 607 * context switch OUT always looks at the hardware state to turn 608 * OFF PMCs and will update a PMC's saved value only if reachable 609 * from the target process record. 610 * 611 * - OP PMCRELEASE could be called on a PMC at any time (the PMC could 612 * be attached to many processes at the time of the call and could 613 * be active on multiple CPUs). 614 * 615 * We prevent further scheduling of the PMC by marking it as in 616 * state 'DELETED'. If the runcount of the PMC is non-zero then 617 * this PMC is currently running on a CPU somewhere. The thread 618 * doing the PMCRELEASE operation waits by repeatedly doing a 619 * pause() till the runcount comes to zero. 620 * 621 * The contents of a PMC descriptor (struct pmc) are protected using 622 * a spin-mutex. In order to save space, we use a mutex pool. 623 * 624 * In terms of lock types used by witness(4), we use: 625 * - Type "pmc-sx", used by the global SX lock. 626 * - Type "pmc-sleep", for sleep mutexes used by logger threads. 627 * - Type "pmc-per-proc", for protecting PMC owner descriptors. 628 * - Type "pmc-leaf", used for all other spin mutexes. 629 */ 630 631 /* 632 * save the cpu binding of the current kthread 633 */ 634 635 static void 636 pmc_save_cpu_binding(struct pmc_binding *pb) 637 { 638 PMCDBG(CPU,BND,2, "%s", "save-cpu"); 639 thread_lock(curthread); 640 pb->pb_bound = sched_is_bound(curthread); 641 pb->pb_cpu = curthread->td_oncpu; 642 thread_unlock(curthread); 643 PMCDBG(CPU,BND,2, "save-cpu cpu=%d", pb->pb_cpu); 644 } 645 646 /* 647 * restore the cpu binding of the current thread 648 */ 649 650 static void 651 pmc_restore_cpu_binding(struct pmc_binding *pb) 652 { 653 PMCDBG(CPU,BND,2, "restore-cpu curcpu=%d restore=%d", 654 curthread->td_oncpu, pb->pb_cpu); 655 thread_lock(curthread); 656 if (pb->pb_bound) 657 sched_bind(curthread, pb->pb_cpu); 658 else 659 sched_unbind(curthread); 660 thread_unlock(curthread); 661 PMCDBG(CPU,BND,2, "%s", "restore-cpu done"); 662 } 663 664 /* 665 * move execution over the specified cpu and bind it there. 666 */ 667 668 static void 669 pmc_select_cpu(int cpu) 670 { 671 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 672 ("[pmc,%d] bad cpu number %d", __LINE__, cpu)); 673 674 /* Never move to an inactive CPU. */ 675 KASSERT(pmc_cpu_is_active(cpu), ("[pmc,%d] selecting inactive " 676 "CPU %d", __LINE__, cpu)); 677 678 PMCDBG(CPU,SEL,2, "select-cpu cpu=%d", cpu); 679 thread_lock(curthread); 680 sched_bind(curthread, cpu); 681 thread_unlock(curthread); 682 683 KASSERT(curthread->td_oncpu == cpu, 684 ("[pmc,%d] CPU not bound [cpu=%d, curr=%d]", __LINE__, 685 cpu, curthread->td_oncpu)); 686 687 PMCDBG(CPU,SEL,2, "select-cpu cpu=%d ok", cpu); 688 } 689 690 /* 691 * Force a context switch. 692 * 693 * We do this by pause'ing for 1 tick -- invoking mi_switch() is not 694 * guaranteed to force a context switch. 695 */ 696 697 static void 698 pmc_force_context_switch(void) 699 { 700 701 pause("pmcctx", 1); 702 } 703 704 /* 705 * Get the file name for an executable. This is a simple wrapper 706 * around vn_fullpath(9). 707 */ 708 709 static void 710 pmc_getfilename(struct vnode *v, char **fullpath, char **freepath) 711 { 712 713 *fullpath = "unknown"; 714 *freepath = NULL; 715 vn_fullpath(curthread, v, fullpath, freepath); 716 } 717 718 /* 719 * remove an process owning PMCs 720 */ 721 722 void 723 pmc_remove_owner(struct pmc_owner *po) 724 { 725 struct pmc *pm, *tmp; 726 727 sx_assert(&pmc_sx, SX_XLOCKED); 728 729 PMCDBG(OWN,ORM,1, "remove-owner po=%p", po); 730 731 /* Remove descriptor from the owner hash table */ 732 LIST_REMOVE(po, po_next); 733 734 /* release all owned PMC descriptors */ 735 LIST_FOREACH_SAFE(pm, &po->po_pmcs, pm_next, tmp) { 736 PMCDBG(OWN,ORM,2, "pmc=%p", pm); 737 KASSERT(pm->pm_owner == po, 738 ("[pmc,%d] owner %p != po %p", __LINE__, pm->pm_owner, po)); 739 740 pmc_release_pmc_descriptor(pm); /* will unlink from the list */ 741 } 742 743 KASSERT(po->po_sscount == 0, 744 ("[pmc,%d] SS count not zero", __LINE__)); 745 KASSERT(LIST_EMPTY(&po->po_pmcs), 746 ("[pmc,%d] PMC list not empty", __LINE__)); 747 748 /* de-configure the log file if present */ 749 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 750 pmclog_deconfigure_log(po); 751 } 752 753 /* 754 * remove an owner process record if all conditions are met. 755 */ 756 757 static void 758 pmc_maybe_remove_owner(struct pmc_owner *po) 759 { 760 761 PMCDBG(OWN,OMR,1, "maybe-remove-owner po=%p", po); 762 763 /* 764 * Remove owner record if 765 * - this process does not own any PMCs 766 * - this process has not allocated a system-wide sampling buffer 767 */ 768 769 if (LIST_EMPTY(&po->po_pmcs) && 770 ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0)) { 771 pmc_remove_owner(po); 772 pmc_destroy_owner_descriptor(po); 773 } 774 } 775 776 /* 777 * Add an association between a target process and a PMC. 778 */ 779 780 static void 781 pmc_link_target_process(struct pmc *pm, struct pmc_process *pp) 782 { 783 int ri; 784 struct pmc_target *pt; 785 786 sx_assert(&pmc_sx, SX_XLOCKED); 787 788 KASSERT(pm != NULL && pp != NULL, 789 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 790 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 791 ("[pmc,%d] Attaching a non-process-virtual pmc=%p to pid=%d", 792 __LINE__, pm, pp->pp_proc->p_pid)); 793 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= ((int) md->pmd_npmc - 1), 794 ("[pmc,%d] Illegal reference count %d for process record %p", 795 __LINE__, pp->pp_refcnt, (void *) pp)); 796 797 ri = PMC_TO_ROWINDEX(pm); 798 799 PMCDBG(PRC,TLK,1, "link-target pmc=%p ri=%d pmc-process=%p", 800 pm, ri, pp); 801 802 #ifdef DEBUG 803 LIST_FOREACH(pt, &pm->pm_targets, pt_next) 804 if (pt->pt_process == pp) 805 KASSERT(0, ("[pmc,%d] pp %p already in pmc %p targets", 806 __LINE__, pp, pm)); 807 #endif 808 809 pt = malloc(sizeof(struct pmc_target), M_PMC, M_WAITOK|M_ZERO); 810 pt->pt_process = pp; 811 812 LIST_INSERT_HEAD(&pm->pm_targets, pt, pt_next); 813 814 atomic_store_rel_ptr((uintptr_t *)&pp->pp_pmcs[ri].pp_pmc, 815 (uintptr_t)pm); 816 817 if (pm->pm_owner->po_owner == pp->pp_proc) 818 pm->pm_flags |= PMC_F_ATTACHED_TO_OWNER; 819 820 /* 821 * Initialize the per-process values at this row index. 822 */ 823 pp->pp_pmcs[ri].pp_pmcval = PMC_TO_MODE(pm) == PMC_MODE_TS ? 824 pm->pm_sc.pm_reloadcount : 0; 825 826 pp->pp_refcnt++; 827 828 } 829 830 /* 831 * Removes the association between a target process and a PMC. 832 */ 833 834 static void 835 pmc_unlink_target_process(struct pmc *pm, struct pmc_process *pp) 836 { 837 int ri; 838 struct proc *p; 839 struct pmc_target *ptgt; 840 841 sx_assert(&pmc_sx, SX_XLOCKED); 842 843 KASSERT(pm != NULL && pp != NULL, 844 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 845 846 KASSERT(pp->pp_refcnt >= 1 && pp->pp_refcnt <= (int) md->pmd_npmc, 847 ("[pmc,%d] Illegal ref count %d on process record %p", 848 __LINE__, pp->pp_refcnt, (void *) pp)); 849 850 ri = PMC_TO_ROWINDEX(pm); 851 852 PMCDBG(PRC,TUL,1, "unlink-target pmc=%p ri=%d pmc-process=%p", 853 pm, ri, pp); 854 855 KASSERT(pp->pp_pmcs[ri].pp_pmc == pm, 856 ("[pmc,%d] PMC ri %d mismatch pmc %p pp->[ri] %p", __LINE__, 857 ri, pm, pp->pp_pmcs[ri].pp_pmc)); 858 859 pp->pp_pmcs[ri].pp_pmc = NULL; 860 pp->pp_pmcs[ri].pp_pmcval = (pmc_value_t) 0; 861 862 /* Remove owner-specific flags */ 863 if (pm->pm_owner->po_owner == pp->pp_proc) { 864 pp->pp_flags &= ~PMC_PP_ENABLE_MSR_ACCESS; 865 pm->pm_flags &= ~PMC_F_ATTACHED_TO_OWNER; 866 } 867 868 pp->pp_refcnt--; 869 870 /* Remove the target process from the PMC structure */ 871 LIST_FOREACH(ptgt, &pm->pm_targets, pt_next) 872 if (ptgt->pt_process == pp) 873 break; 874 875 KASSERT(ptgt != NULL, ("[pmc,%d] process %p (pp: %p) not found " 876 "in pmc %p", __LINE__, pp->pp_proc, pp, pm)); 877 878 LIST_REMOVE(ptgt, pt_next); 879 free(ptgt, M_PMC); 880 881 /* if the PMC now lacks targets, send the owner a SIGIO */ 882 if (LIST_EMPTY(&pm->pm_targets)) { 883 p = pm->pm_owner->po_owner; 884 PROC_LOCK(p); 885 psignal(p, SIGIO); 886 PROC_UNLOCK(p); 887 888 PMCDBG(PRC,SIG,2, "signalling proc=%p signal=%d", p, 889 SIGIO); 890 } 891 } 892 893 /* 894 * Check if PMC 'pm' may be attached to target process 't'. 895 */ 896 897 static int 898 pmc_can_attach(struct pmc *pm, struct proc *t) 899 { 900 struct proc *o; /* pmc owner */ 901 struct ucred *oc, *tc; /* owner, target credentials */ 902 int decline_attach, i; 903 904 /* 905 * A PMC's owner can always attach that PMC to itself. 906 */ 907 908 if ((o = pm->pm_owner->po_owner) == t) 909 return 0; 910 911 PROC_LOCK(o); 912 oc = o->p_ucred; 913 crhold(oc); 914 PROC_UNLOCK(o); 915 916 PROC_LOCK(t); 917 tc = t->p_ucred; 918 crhold(tc); 919 PROC_UNLOCK(t); 920 921 /* 922 * The effective uid of the PMC owner should match at least one 923 * of the {effective,real,saved} uids of the target process. 924 */ 925 926 decline_attach = oc->cr_uid != tc->cr_uid && 927 oc->cr_uid != tc->cr_svuid && 928 oc->cr_uid != tc->cr_ruid; 929 930 /* 931 * Every one of the target's group ids, must be in the owner's 932 * group list. 933 */ 934 for (i = 0; !decline_attach && i < tc->cr_ngroups; i++) 935 decline_attach = !groupmember(tc->cr_groups[i], oc); 936 937 /* check the read and saved gids too */ 938 if (decline_attach == 0) 939 decline_attach = !groupmember(tc->cr_rgid, oc) || 940 !groupmember(tc->cr_svgid, oc); 941 942 crfree(tc); 943 crfree(oc); 944 945 return !decline_attach; 946 } 947 948 /* 949 * Attach a process to a PMC. 950 */ 951 952 static int 953 pmc_attach_one_process(struct proc *p, struct pmc *pm) 954 { 955 int ri; 956 char *fullpath, *freepath; 957 struct pmc_process *pp; 958 959 sx_assert(&pmc_sx, SX_XLOCKED); 960 961 PMCDBG(PRC,ATT,2, "attach-one pm=%p ri=%d proc=%p (%d, %s)", pm, 962 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 963 964 /* 965 * Locate the process descriptor corresponding to process 'p', 966 * allocating space as needed. 967 * 968 * Verify that rowindex 'pm_rowindex' is free in the process 969 * descriptor. 970 * 971 * If not, allocate space for a descriptor and link the 972 * process descriptor and PMC. 973 */ 974 ri = PMC_TO_ROWINDEX(pm); 975 976 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_ALLOCATE)) == NULL) 977 return ENOMEM; 978 979 if (pp->pp_pmcs[ri].pp_pmc == pm) /* already present at slot [ri] */ 980 return EEXIST; 981 982 if (pp->pp_pmcs[ri].pp_pmc != NULL) 983 return EBUSY; 984 985 pmc_link_target_process(pm, pp); 986 987 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) && 988 (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) == 0) 989 pm->pm_flags |= PMC_F_NEEDS_LOGFILE; 990 991 pm->pm_flags |= PMC_F_ATTACH_DONE; /* mark as attached */ 992 993 /* issue an attach event to a configured log file */ 994 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) { 995 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 996 if (p->p_flag & P_KTHREAD) { 997 fullpath = kernelname; 998 freepath = NULL; 999 } else 1000 pmclog_process_pmcattach(pm, p->p_pid, fullpath); 1001 if (freepath) 1002 free(freepath, M_TEMP); 1003 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1004 pmc_log_process_mappings(pm->pm_owner, p); 1005 } 1006 /* mark process as using HWPMCs */ 1007 PROC_LOCK(p); 1008 p->p_flag |= P_HWPMC; 1009 PROC_UNLOCK(p); 1010 1011 return 0; 1012 } 1013 1014 /* 1015 * Attach a process and optionally its children 1016 */ 1017 1018 static int 1019 pmc_attach_process(struct proc *p, struct pmc *pm) 1020 { 1021 int error; 1022 struct proc *top; 1023 1024 sx_assert(&pmc_sx, SX_XLOCKED); 1025 1026 PMCDBG(PRC,ATT,1, "attach pm=%p ri=%d proc=%p (%d, %s)", pm, 1027 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1028 1029 1030 /* 1031 * If this PMC successfully allowed a GETMSR operation 1032 * in the past, disallow further ATTACHes. 1033 */ 1034 1035 if ((pm->pm_flags & PMC_PP_ENABLE_MSR_ACCESS) != 0) 1036 return EPERM; 1037 1038 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 1039 return pmc_attach_one_process(p, pm); 1040 1041 /* 1042 * Traverse all child processes, attaching them to 1043 * this PMC. 1044 */ 1045 1046 sx_slock(&proctree_lock); 1047 1048 top = p; 1049 1050 for (;;) { 1051 if ((error = pmc_attach_one_process(p, pm)) != 0) 1052 break; 1053 if (!LIST_EMPTY(&p->p_children)) 1054 p = LIST_FIRST(&p->p_children); 1055 else for (;;) { 1056 if (p == top) 1057 goto done; 1058 if (LIST_NEXT(p, p_sibling)) { 1059 p = LIST_NEXT(p, p_sibling); 1060 break; 1061 } 1062 p = p->p_pptr; 1063 } 1064 } 1065 1066 if (error) 1067 (void) pmc_detach_process(top, pm); 1068 1069 done: 1070 sx_sunlock(&proctree_lock); 1071 return error; 1072 } 1073 1074 /* 1075 * Detach a process from a PMC. If there are no other PMCs tracking 1076 * this process, remove the process structure from its hash table. If 1077 * 'flags' contains PMC_FLAG_REMOVE, then free the process structure. 1078 */ 1079 1080 static int 1081 pmc_detach_one_process(struct proc *p, struct pmc *pm, int flags) 1082 { 1083 int ri; 1084 struct pmc_process *pp; 1085 1086 sx_assert(&pmc_sx, SX_XLOCKED); 1087 1088 KASSERT(pm != NULL, 1089 ("[pmc,%d] null pm pointer", __LINE__)); 1090 1091 ri = PMC_TO_ROWINDEX(pm); 1092 1093 PMCDBG(PRC,ATT,2, "detach-one pm=%p ri=%d proc=%p (%d, %s) flags=0x%x", 1094 pm, ri, p, p->p_pid, p->p_comm, flags); 1095 1096 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) 1097 return ESRCH; 1098 1099 if (pp->pp_pmcs[ri].pp_pmc != pm) 1100 return EINVAL; 1101 1102 pmc_unlink_target_process(pm, pp); 1103 1104 /* Issue a detach entry if a log file is configured */ 1105 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) 1106 pmclog_process_pmcdetach(pm, p->p_pid); 1107 1108 /* 1109 * If there are no PMCs targetting this process, we remove its 1110 * descriptor from the target hash table and unset the P_HWPMC 1111 * flag in the struct proc. 1112 */ 1113 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= (int) md->pmd_npmc, 1114 ("[pmc,%d] Illegal refcnt %d for process struct %p", 1115 __LINE__, pp->pp_refcnt, pp)); 1116 1117 if (pp->pp_refcnt != 0) /* still a target of some PMC */ 1118 return 0; 1119 1120 pmc_remove_process_descriptor(pp); 1121 1122 if (flags & PMC_FLAG_REMOVE) 1123 free(pp, M_PMC); 1124 1125 PROC_LOCK(p); 1126 p->p_flag &= ~P_HWPMC; 1127 PROC_UNLOCK(p); 1128 1129 return 0; 1130 } 1131 1132 /* 1133 * Detach a process and optionally its descendants from a PMC. 1134 */ 1135 1136 static int 1137 pmc_detach_process(struct proc *p, struct pmc *pm) 1138 { 1139 struct proc *top; 1140 1141 sx_assert(&pmc_sx, SX_XLOCKED); 1142 1143 PMCDBG(PRC,ATT,1, "detach pm=%p ri=%d proc=%p (%d, %s)", pm, 1144 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1145 1146 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 1147 return pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); 1148 1149 /* 1150 * Traverse all children, detaching them from this PMC. We 1151 * ignore errors since we could be detaching a PMC from a 1152 * partially attached proc tree. 1153 */ 1154 1155 sx_slock(&proctree_lock); 1156 1157 top = p; 1158 1159 for (;;) { 1160 (void) pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); 1161 1162 if (!LIST_EMPTY(&p->p_children)) 1163 p = LIST_FIRST(&p->p_children); 1164 else for (;;) { 1165 if (p == top) 1166 goto done; 1167 if (LIST_NEXT(p, p_sibling)) { 1168 p = LIST_NEXT(p, p_sibling); 1169 break; 1170 } 1171 p = p->p_pptr; 1172 } 1173 } 1174 1175 done: 1176 sx_sunlock(&proctree_lock); 1177 1178 if (LIST_EMPTY(&pm->pm_targets)) 1179 pm->pm_flags &= ~PMC_F_ATTACH_DONE; 1180 1181 return 0; 1182 } 1183 1184 1185 /* 1186 * Thread context switch IN 1187 */ 1188 1189 static void 1190 pmc_process_csw_in(struct thread *td) 1191 { 1192 int cpu; 1193 unsigned int adjri, ri; 1194 struct pmc *pm; 1195 struct proc *p; 1196 struct pmc_cpu *pc; 1197 struct pmc_hw *phw; 1198 pmc_value_t newvalue; 1199 struct pmc_process *pp; 1200 struct pmc_classdep *pcd; 1201 1202 p = td->td_proc; 1203 1204 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE)) == NULL) 1205 return; 1206 1207 KASSERT(pp->pp_proc == td->td_proc, 1208 ("[pmc,%d] not my thread state", __LINE__)); 1209 1210 critical_enter(); /* no preemption from this point */ 1211 1212 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1213 1214 PMCDBG(CSW,SWI,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1215 p->p_pid, p->p_comm, pp); 1216 1217 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 1218 ("[pmc,%d] wierd CPU id %d", __LINE__, cpu)); 1219 1220 pc = pmc_pcpu[cpu]; 1221 1222 for (ri = 0; ri < md->pmd_npmc; ri++) { 1223 1224 if ((pm = pp->pp_pmcs[ri].pp_pmc) == NULL) 1225 continue; 1226 1227 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 1228 ("[pmc,%d] Target PMC in non-virtual mode (%d)", 1229 __LINE__, PMC_TO_MODE(pm))); 1230 1231 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1232 ("[pmc,%d] Row index mismatch pmc %d != ri %d", 1233 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1234 1235 /* 1236 * Only PMCs that are marked as 'RUNNING' need 1237 * be placed on hardware. 1238 */ 1239 1240 if (pm->pm_state != PMC_STATE_RUNNING) 1241 continue; 1242 1243 /* increment PMC runcount */ 1244 atomic_add_rel_32(&pm->pm_runcount, 1); 1245 1246 /* configure the HWPMC we are going to use. */ 1247 pcd = pmc_ri_to_classdep(md, ri, &adjri); 1248 pcd->pcd_config_pmc(cpu, adjri, pm); 1249 1250 phw = pc->pc_hwpmcs[ri]; 1251 1252 KASSERT(phw != NULL, 1253 ("[pmc,%d] null hw pointer", __LINE__)); 1254 1255 KASSERT(phw->phw_pmc == pm, 1256 ("[pmc,%d] hw->pmc %p != pmc %p", __LINE__, 1257 phw->phw_pmc, pm)); 1258 1259 /* 1260 * Write out saved value and start the PMC. 1261 * 1262 * Sampling PMCs use a per-process value, while 1263 * counting mode PMCs use a per-pmc value that is 1264 * inherited across descendants. 1265 */ 1266 if (PMC_TO_MODE(pm) == PMC_MODE_TS) { 1267 mtx_pool_lock_spin(pmc_mtxpool, pm); 1268 newvalue = PMC_PCPU_SAVED(cpu,ri) = 1269 pp->pp_pmcs[ri].pp_pmcval; 1270 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1271 } else { 1272 KASSERT(PMC_TO_MODE(pm) == PMC_MODE_TC, 1273 ("[pmc,%d] illegal mode=%d", __LINE__, 1274 PMC_TO_MODE(pm))); 1275 mtx_pool_lock_spin(pmc_mtxpool, pm); 1276 newvalue = PMC_PCPU_SAVED(cpu, ri) = 1277 pm->pm_gv.pm_savedvalue; 1278 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1279 } 1280 1281 PMCDBG(CSW,SWI,1,"cpu=%d ri=%d new=%jd", cpu, ri, newvalue); 1282 1283 pcd->pcd_write_pmc(cpu, adjri, newvalue); 1284 pcd->pcd_start_pmc(cpu, adjri); 1285 } 1286 1287 /* 1288 * perform any other architecture/cpu dependent thread 1289 * switch-in actions. 1290 */ 1291 1292 (void) (*md->pmd_switch_in)(pc, pp); 1293 1294 critical_exit(); 1295 1296 } 1297 1298 /* 1299 * Thread context switch OUT. 1300 */ 1301 1302 static void 1303 pmc_process_csw_out(struct thread *td) 1304 { 1305 int cpu; 1306 int64_t tmp; 1307 struct pmc *pm; 1308 struct proc *p; 1309 enum pmc_mode mode; 1310 struct pmc_cpu *pc; 1311 pmc_value_t newvalue; 1312 unsigned int adjri, ri; 1313 struct pmc_process *pp; 1314 struct pmc_classdep *pcd; 1315 1316 1317 /* 1318 * Locate our process descriptor; this may be NULL if 1319 * this process is exiting and we have already removed 1320 * the process from the target process table. 1321 * 1322 * Note that due to kernel preemption, multiple 1323 * context switches may happen while the process is 1324 * exiting. 1325 * 1326 * Note also that if the target process cannot be 1327 * found we still need to deconfigure any PMCs that 1328 * are currently running on hardware. 1329 */ 1330 1331 p = td->td_proc; 1332 pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE); 1333 1334 /* 1335 * save PMCs 1336 */ 1337 1338 critical_enter(); 1339 1340 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1341 1342 PMCDBG(CSW,SWO,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1343 p->p_pid, p->p_comm, pp); 1344 1345 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 1346 ("[pmc,%d wierd CPU id %d", __LINE__, cpu)); 1347 1348 pc = pmc_pcpu[cpu]; 1349 1350 /* 1351 * When a PMC gets unlinked from a target PMC, it will 1352 * be removed from the target's pp_pmc[] array. 1353 * 1354 * However, on a MP system, the target could have been 1355 * executing on another CPU at the time of the unlink. 1356 * So, at context switch OUT time, we need to look at 1357 * the hardware to determine if a PMC is scheduled on 1358 * it. 1359 */ 1360 1361 for (ri = 0; ri < md->pmd_npmc; ri++) { 1362 1363 pcd = pmc_ri_to_classdep(md, ri, &adjri); 1364 pm = NULL; 1365 (void) (*pcd->pcd_get_config)(cpu, adjri, &pm); 1366 1367 if (pm == NULL) /* nothing at this row index */ 1368 continue; 1369 1370 mode = PMC_TO_MODE(pm); 1371 if (!PMC_IS_VIRTUAL_MODE(mode)) 1372 continue; /* not a process virtual PMC */ 1373 1374 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1375 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 1376 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1377 1378 /* Stop hardware if not already stopped */ 1379 if (pm->pm_stalled == 0) 1380 pcd->pcd_stop_pmc(cpu, adjri); 1381 1382 /* reduce this PMC's runcount */ 1383 atomic_subtract_rel_32(&pm->pm_runcount, 1); 1384 1385 /* 1386 * If this PMC is associated with this process, 1387 * save the reading. 1388 */ 1389 1390 if (pp != NULL && pp->pp_pmcs[ri].pp_pmc != NULL) { 1391 1392 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 1393 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", __LINE__, 1394 pm, ri, pp->pp_pmcs[ri].pp_pmc)); 1395 1396 KASSERT(pp->pp_refcnt > 0, 1397 ("[pmc,%d] pp refcnt = %d", __LINE__, 1398 pp->pp_refcnt)); 1399 1400 pcd->pcd_read_pmc(cpu, adjri, &newvalue); 1401 1402 tmp = newvalue - PMC_PCPU_SAVED(cpu,ri); 1403 1404 PMCDBG(CSW,SWO,1,"cpu=%d ri=%d tmp=%jd", cpu, ri, 1405 tmp); 1406 1407 if (mode == PMC_MODE_TS) { 1408 1409 /* 1410 * For sampling process-virtual PMCs, 1411 * we expect the count to be 1412 * decreasing as the 'value' 1413 * programmed into the PMC is the 1414 * number of events to be seen till 1415 * the next sampling interrupt. 1416 */ 1417 if (tmp < 0) 1418 tmp += pm->pm_sc.pm_reloadcount; 1419 mtx_pool_lock_spin(pmc_mtxpool, pm); 1420 pp->pp_pmcs[ri].pp_pmcval -= tmp; 1421 if ((int64_t) pp->pp_pmcs[ri].pp_pmcval < 0) 1422 pp->pp_pmcs[ri].pp_pmcval += 1423 pm->pm_sc.pm_reloadcount; 1424 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1425 1426 } else { 1427 1428 /* 1429 * For counting process-virtual PMCs, 1430 * we expect the count to be 1431 * increasing monotonically, modulo a 64 1432 * bit wraparound. 1433 */ 1434 KASSERT((int64_t) tmp >= 0, 1435 ("[pmc,%d] negative increment cpu=%d " 1436 "ri=%d newvalue=%jx saved=%jx " 1437 "incr=%jx", __LINE__, cpu, ri, 1438 newvalue, PMC_PCPU_SAVED(cpu,ri), tmp)); 1439 1440 mtx_pool_lock_spin(pmc_mtxpool, pm); 1441 pm->pm_gv.pm_savedvalue += tmp; 1442 pp->pp_pmcs[ri].pp_pmcval += tmp; 1443 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1444 1445 if (pm->pm_flags & PMC_F_LOG_PROCCSW) 1446 pmclog_process_proccsw(pm, pp, tmp); 1447 } 1448 } 1449 1450 /* mark hardware as free */ 1451 pcd->pcd_config_pmc(cpu, adjri, NULL); 1452 } 1453 1454 /* 1455 * perform any other architecture/cpu dependent thread 1456 * switch out functions. 1457 */ 1458 1459 (void) (*md->pmd_switch_out)(pc, pp); 1460 1461 critical_exit(); 1462 } 1463 1464 /* 1465 * Log a KLD operation. 1466 */ 1467 1468 static void 1469 pmc_process_kld_load(struct pmckern_map_in *pkm) 1470 { 1471 struct pmc_owner *po; 1472 1473 sx_assert(&pmc_sx, SX_LOCKED); 1474 1475 /* 1476 * Notify owners of system sampling PMCs about KLD operations. 1477 */ 1478 1479 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1480 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1481 pmclog_process_map_in(po, (pid_t) -1, pkm->pm_address, 1482 (char *) pkm->pm_file); 1483 1484 /* 1485 * TODO: Notify owners of (all) process-sampling PMCs too. 1486 */ 1487 1488 return; 1489 } 1490 1491 static void 1492 pmc_process_kld_unload(struct pmckern_map_out *pkm) 1493 { 1494 struct pmc_owner *po; 1495 1496 sx_assert(&pmc_sx, SX_LOCKED); 1497 1498 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1499 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1500 pmclog_process_map_out(po, (pid_t) -1, 1501 pkm->pm_address, pkm->pm_address + pkm->pm_size); 1502 1503 /* 1504 * TODO: Notify owners of process-sampling PMCs. 1505 */ 1506 } 1507 1508 /* 1509 * A mapping change for a process. 1510 */ 1511 1512 static void 1513 pmc_process_mmap(struct thread *td, struct pmckern_map_in *pkm) 1514 { 1515 int ri; 1516 pid_t pid; 1517 char *fullpath, *freepath; 1518 const struct pmc *pm; 1519 struct pmc_owner *po; 1520 const struct pmc_process *pp; 1521 1522 freepath = fullpath = NULL; 1523 pmc_getfilename((struct vnode *) pkm->pm_file, &fullpath, &freepath); 1524 1525 pid = td->td_proc->p_pid; 1526 1527 /* Inform owners of all system-wide sampling PMCs. */ 1528 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1529 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1530 pmclog_process_map_in(po, pid, pkm->pm_address, fullpath); 1531 1532 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1533 goto done; 1534 1535 /* 1536 * Inform sampling PMC owners tracking this process. 1537 */ 1538 for (ri = 0; ri < md->pmd_npmc; ri++) 1539 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1540 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1541 pmclog_process_map_in(pm->pm_owner, 1542 pid, pkm->pm_address, fullpath); 1543 1544 done: 1545 if (freepath) 1546 free(freepath, M_TEMP); 1547 } 1548 1549 1550 /* 1551 * Log an munmap request. 1552 */ 1553 1554 static void 1555 pmc_process_munmap(struct thread *td, struct pmckern_map_out *pkm) 1556 { 1557 int ri; 1558 pid_t pid; 1559 struct pmc_owner *po; 1560 const struct pmc *pm; 1561 const struct pmc_process *pp; 1562 1563 pid = td->td_proc->p_pid; 1564 1565 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1566 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1567 pmclog_process_map_out(po, pid, pkm->pm_address, 1568 pkm->pm_address + pkm->pm_size); 1569 1570 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1571 return; 1572 1573 for (ri = 0; ri < md->pmd_npmc; ri++) 1574 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1575 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1576 pmclog_process_map_out(pm->pm_owner, pid, 1577 pkm->pm_address, pkm->pm_address + pkm->pm_size); 1578 } 1579 1580 /* 1581 * Log mapping information about the kernel. 1582 */ 1583 1584 static void 1585 pmc_log_kernel_mappings(struct pmc *pm) 1586 { 1587 struct pmc_owner *po; 1588 struct pmckern_map_in *km, *kmbase; 1589 1590 sx_assert(&pmc_sx, SX_LOCKED); 1591 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 1592 ("[pmc,%d] non-sampling PMC (%p) desires mapping information", 1593 __LINE__, (void *) pm)); 1594 1595 po = pm->pm_owner; 1596 1597 if (po->po_flags & PMC_PO_INITIAL_MAPPINGS_DONE) 1598 return; 1599 1600 /* 1601 * Log the current set of kernel modules. 1602 */ 1603 kmbase = linker_hwpmc_list_objects(); 1604 for (km = kmbase; km->pm_file != NULL; km++) { 1605 PMCDBG(LOG,REG,1,"%s %p", (char *) km->pm_file, 1606 (void *) km->pm_address); 1607 pmclog_process_map_in(po, (pid_t) -1, km->pm_address, 1608 km->pm_file); 1609 } 1610 free(kmbase, M_LINKER); 1611 1612 po->po_flags |= PMC_PO_INITIAL_MAPPINGS_DONE; 1613 } 1614 1615 /* 1616 * Log the mappings for a single process. 1617 */ 1618 1619 static void 1620 pmc_log_process_mappings(struct pmc_owner *po, struct proc *p) 1621 { 1622 } 1623 1624 /* 1625 * Log mappings for all processes in the system. 1626 */ 1627 1628 static void 1629 pmc_log_all_process_mappings(struct pmc_owner *po) 1630 { 1631 struct proc *p, *top; 1632 1633 sx_assert(&pmc_sx, SX_XLOCKED); 1634 1635 if ((p = pfind(1)) == NULL) 1636 panic("[pmc,%d] Cannot find init", __LINE__); 1637 1638 PROC_UNLOCK(p); 1639 1640 sx_slock(&proctree_lock); 1641 1642 top = p; 1643 1644 for (;;) { 1645 pmc_log_process_mappings(po, p); 1646 if (!LIST_EMPTY(&p->p_children)) 1647 p = LIST_FIRST(&p->p_children); 1648 else for (;;) { 1649 if (p == top) 1650 goto done; 1651 if (LIST_NEXT(p, p_sibling)) { 1652 p = LIST_NEXT(p, p_sibling); 1653 break; 1654 } 1655 p = p->p_pptr; 1656 } 1657 } 1658 done: 1659 sx_sunlock(&proctree_lock); 1660 } 1661 1662 /* 1663 * The 'hook' invoked from the kernel proper 1664 */ 1665 1666 1667 #ifdef DEBUG 1668 const char *pmc_hooknames[] = { 1669 /* these strings correspond to PMC_FN_* in <sys/pmckern.h> */ 1670 "", 1671 "EXEC", 1672 "CSW-IN", 1673 "CSW-OUT", 1674 "SAMPLE", 1675 "KLDLOAD", 1676 "KLDUNLOAD", 1677 "MMAP", 1678 "MUNMAP", 1679 "CALLCHAIN" 1680 }; 1681 #endif 1682 1683 static int 1684 pmc_hook_handler(struct thread *td, int function, void *arg) 1685 { 1686 1687 PMCDBG(MOD,PMH,1, "hook td=%p func=%d \"%s\" arg=%p", td, function, 1688 pmc_hooknames[function], arg); 1689 1690 switch (function) 1691 { 1692 1693 /* 1694 * Process exec() 1695 */ 1696 1697 case PMC_FN_PROCESS_EXEC: 1698 { 1699 char *fullpath, *freepath; 1700 unsigned int ri; 1701 int is_using_hwpmcs; 1702 struct pmc *pm; 1703 struct proc *p; 1704 struct pmc_owner *po; 1705 struct pmc_process *pp; 1706 struct pmckern_procexec *pk; 1707 1708 sx_assert(&pmc_sx, SX_XLOCKED); 1709 1710 p = td->td_proc; 1711 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 1712 1713 pk = (struct pmckern_procexec *) arg; 1714 1715 /* Inform owners of SS mode PMCs of the exec event. */ 1716 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1717 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1718 pmclog_process_procexec(po, PMC_ID_INVALID, 1719 p->p_pid, pk->pm_entryaddr, fullpath); 1720 1721 PROC_LOCK(p); 1722 is_using_hwpmcs = p->p_flag & P_HWPMC; 1723 PROC_UNLOCK(p); 1724 1725 if (!is_using_hwpmcs) { 1726 if (freepath) 1727 free(freepath, M_TEMP); 1728 break; 1729 } 1730 1731 /* 1732 * PMCs are not inherited across an exec(): remove any 1733 * PMCs that this process is the owner of. 1734 */ 1735 1736 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 1737 pmc_remove_owner(po); 1738 pmc_destroy_owner_descriptor(po); 1739 } 1740 1741 /* 1742 * If the process being exec'ed is not the target of any 1743 * PMC, we are done. 1744 */ 1745 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) { 1746 if (freepath) 1747 free(freepath, M_TEMP); 1748 break; 1749 } 1750 1751 /* 1752 * Log the exec event to all monitoring owners. Skip 1753 * owners who have already recieved the event because 1754 * they had system sampling PMCs active. 1755 */ 1756 for (ri = 0; ri < md->pmd_npmc; ri++) 1757 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 1758 po = pm->pm_owner; 1759 if (po->po_sscount == 0 && 1760 po->po_flags & PMC_PO_OWNS_LOGFILE) 1761 pmclog_process_procexec(po, pm->pm_id, 1762 p->p_pid, pk->pm_entryaddr, 1763 fullpath); 1764 } 1765 1766 if (freepath) 1767 free(freepath, M_TEMP); 1768 1769 1770 PMCDBG(PRC,EXC,1, "exec proc=%p (%d, %s) cred-changed=%d", 1771 p, p->p_pid, p->p_comm, pk->pm_credentialschanged); 1772 1773 if (pk->pm_credentialschanged == 0) /* no change */ 1774 break; 1775 1776 /* 1777 * If the newly exec()'ed process has a different credential 1778 * than before, allow it to be the target of a PMC only if 1779 * the PMC's owner has sufficient priviledge. 1780 */ 1781 1782 for (ri = 0; ri < md->pmd_npmc; ri++) 1783 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) 1784 if (pmc_can_attach(pm, td->td_proc) != 0) 1785 pmc_detach_one_process(td->td_proc, 1786 pm, PMC_FLAG_NONE); 1787 1788 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= (int) md->pmd_npmc, 1789 ("[pmc,%d] Illegal ref count %d on pp %p", __LINE__, 1790 pp->pp_refcnt, pp)); 1791 1792 /* 1793 * If this process is no longer the target of any 1794 * PMCs, we can remove the process entry and free 1795 * up space. 1796 */ 1797 1798 if (pp->pp_refcnt == 0) { 1799 pmc_remove_process_descriptor(pp); 1800 free(pp, M_PMC); 1801 break; 1802 } 1803 1804 } 1805 break; 1806 1807 case PMC_FN_CSW_IN: 1808 pmc_process_csw_in(td); 1809 break; 1810 1811 case PMC_FN_CSW_OUT: 1812 pmc_process_csw_out(td); 1813 break; 1814 1815 /* 1816 * Process accumulated PC samples. 1817 * 1818 * This function is expected to be called by hardclock() for 1819 * each CPU that has accumulated PC samples. 1820 * 1821 * This function is to be executed on the CPU whose samples 1822 * are being processed. 1823 */ 1824 case PMC_FN_DO_SAMPLES: 1825 1826 /* 1827 * Clear the cpu specific bit in the CPU mask before 1828 * do the rest of the processing. If the NMI handler 1829 * gets invoked after the "atomic_clear_int()" call 1830 * below but before "pmc_process_samples()" gets 1831 * around to processing the interrupt, then we will 1832 * come back here at the next hardclock() tick (and 1833 * may find nothing to do if "pmc_process_samples()" 1834 * had already processed the interrupt). We don't 1835 * lose the interrupt sample. 1836 */ 1837 atomic_clear_int(&pmc_cpumask, (1 << PCPU_GET(cpuid))); 1838 pmc_process_samples(PCPU_GET(cpuid)); 1839 break; 1840 1841 1842 case PMC_FN_KLD_LOAD: 1843 sx_assert(&pmc_sx, SX_LOCKED); 1844 pmc_process_kld_load((struct pmckern_map_in *) arg); 1845 break; 1846 1847 case PMC_FN_KLD_UNLOAD: 1848 sx_assert(&pmc_sx, SX_LOCKED); 1849 pmc_process_kld_unload((struct pmckern_map_out *) arg); 1850 break; 1851 1852 case PMC_FN_MMAP: 1853 sx_assert(&pmc_sx, SX_LOCKED); 1854 pmc_process_mmap(td, (struct pmckern_map_in *) arg); 1855 break; 1856 1857 case PMC_FN_MUNMAP: 1858 sx_assert(&pmc_sx, SX_LOCKED); 1859 pmc_process_munmap(td, (struct pmckern_map_out *) arg); 1860 break; 1861 1862 case PMC_FN_USER_CALLCHAIN: 1863 /* 1864 * Record a call chain. 1865 */ 1866 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 1867 __LINE__)); 1868 pmc_capture_user_callchain(PCPU_GET(cpuid), 1869 (struct trapframe *) arg); 1870 td->td_pflags &= ~TDP_CALLCHAIN; 1871 break; 1872 1873 default: 1874 #ifdef DEBUG 1875 KASSERT(0, ("[pmc,%d] unknown hook %d\n", __LINE__, function)); 1876 #endif 1877 break; 1878 1879 } 1880 1881 return 0; 1882 } 1883 1884 /* 1885 * allocate a 'struct pmc_owner' descriptor in the owner hash table. 1886 */ 1887 1888 static struct pmc_owner * 1889 pmc_allocate_owner_descriptor(struct proc *p) 1890 { 1891 uint32_t hindex; 1892 struct pmc_owner *po; 1893 struct pmc_ownerhash *poh; 1894 1895 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 1896 poh = &pmc_ownerhash[hindex]; 1897 1898 /* allocate space for N pointers and one descriptor struct */ 1899 po = malloc(sizeof(struct pmc_owner), M_PMC, M_WAITOK|M_ZERO); 1900 po->po_sscount = po->po_error = po->po_flags = 0; 1901 po->po_file = NULL; 1902 po->po_owner = p; 1903 po->po_kthread = NULL; 1904 LIST_INIT(&po->po_pmcs); 1905 LIST_INSERT_HEAD(poh, po, po_next); /* insert into hash table */ 1906 1907 TAILQ_INIT(&po->po_logbuffers); 1908 mtx_init(&po->po_mtx, "pmc-owner-mtx", "pmc-per-proc", MTX_SPIN); 1909 1910 PMCDBG(OWN,ALL,1, "allocate-owner proc=%p (%d, %s) pmc-owner=%p", 1911 p, p->p_pid, p->p_comm, po); 1912 1913 return po; 1914 } 1915 1916 static void 1917 pmc_destroy_owner_descriptor(struct pmc_owner *po) 1918 { 1919 1920 PMCDBG(OWN,REL,1, "destroy-owner po=%p proc=%p (%d, %s)", 1921 po, po->po_owner, po->po_owner->p_pid, po->po_owner->p_comm); 1922 1923 mtx_destroy(&po->po_mtx); 1924 free(po, M_PMC); 1925 } 1926 1927 /* 1928 * find the descriptor corresponding to process 'p', adding or removing it 1929 * as specified by 'mode'. 1930 */ 1931 1932 static struct pmc_process * 1933 pmc_find_process_descriptor(struct proc *p, uint32_t mode) 1934 { 1935 uint32_t hindex; 1936 struct pmc_process *pp, *ppnew; 1937 struct pmc_processhash *pph; 1938 1939 hindex = PMC_HASH_PTR(p, pmc_processhashmask); 1940 pph = &pmc_processhash[hindex]; 1941 1942 ppnew = NULL; 1943 1944 /* 1945 * Pre-allocate memory in the FIND_ALLOCATE case since we 1946 * cannot call malloc(9) once we hold a spin lock. 1947 */ 1948 if (mode & PMC_FLAG_ALLOCATE) 1949 ppnew = malloc(sizeof(struct pmc_process) + md->pmd_npmc * 1950 sizeof(struct pmc_targetstate), M_PMC, M_WAITOK|M_ZERO); 1951 1952 mtx_lock_spin(&pmc_processhash_mtx); 1953 LIST_FOREACH(pp, pph, pp_next) 1954 if (pp->pp_proc == p) 1955 break; 1956 1957 if ((mode & PMC_FLAG_REMOVE) && pp != NULL) 1958 LIST_REMOVE(pp, pp_next); 1959 1960 if ((mode & PMC_FLAG_ALLOCATE) && pp == NULL && 1961 ppnew != NULL) { 1962 ppnew->pp_proc = p; 1963 LIST_INSERT_HEAD(pph, ppnew, pp_next); 1964 pp = ppnew; 1965 ppnew = NULL; 1966 } 1967 mtx_unlock_spin(&pmc_processhash_mtx); 1968 1969 if (pp != NULL && ppnew != NULL) 1970 free(ppnew, M_PMC); 1971 1972 return pp; 1973 } 1974 1975 /* 1976 * remove a process descriptor from the process hash table. 1977 */ 1978 1979 static void 1980 pmc_remove_process_descriptor(struct pmc_process *pp) 1981 { 1982 KASSERT(pp->pp_refcnt == 0, 1983 ("[pmc,%d] Removing process descriptor %p with count %d", 1984 __LINE__, pp, pp->pp_refcnt)); 1985 1986 mtx_lock_spin(&pmc_processhash_mtx); 1987 LIST_REMOVE(pp, pp_next); 1988 mtx_unlock_spin(&pmc_processhash_mtx); 1989 } 1990 1991 1992 /* 1993 * find an owner descriptor corresponding to proc 'p' 1994 */ 1995 1996 static struct pmc_owner * 1997 pmc_find_owner_descriptor(struct proc *p) 1998 { 1999 uint32_t hindex; 2000 struct pmc_owner *po; 2001 struct pmc_ownerhash *poh; 2002 2003 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 2004 poh = &pmc_ownerhash[hindex]; 2005 2006 po = NULL; 2007 LIST_FOREACH(po, poh, po_next) 2008 if (po->po_owner == p) 2009 break; 2010 2011 PMCDBG(OWN,FND,1, "find-owner proc=%p (%d, %s) hindex=0x%x -> " 2012 "pmc-owner=%p", p, p->p_pid, p->p_comm, hindex, po); 2013 2014 return po; 2015 } 2016 2017 /* 2018 * pmc_allocate_pmc_descriptor 2019 * 2020 * Allocate a pmc descriptor and initialize its 2021 * fields. 2022 */ 2023 2024 static struct pmc * 2025 pmc_allocate_pmc_descriptor(void) 2026 { 2027 struct pmc *pmc; 2028 2029 pmc = malloc(sizeof(struct pmc), M_PMC, M_WAITOK|M_ZERO); 2030 2031 if (pmc != NULL) { 2032 pmc->pm_owner = NULL; 2033 LIST_INIT(&pmc->pm_targets); 2034 } 2035 2036 PMCDBG(PMC,ALL,1, "allocate-pmc -> pmc=%p", pmc); 2037 2038 return pmc; 2039 } 2040 2041 /* 2042 * Destroy a pmc descriptor. 2043 */ 2044 2045 static void 2046 pmc_destroy_pmc_descriptor(struct pmc *pm) 2047 { 2048 (void) pm; 2049 2050 #ifdef DEBUG 2051 KASSERT(pm->pm_state == PMC_STATE_DELETED || 2052 pm->pm_state == PMC_STATE_FREE, 2053 ("[pmc,%d] destroying non-deleted PMC", __LINE__)); 2054 KASSERT(LIST_EMPTY(&pm->pm_targets), 2055 ("[pmc,%d] destroying pmc with targets", __LINE__)); 2056 KASSERT(pm->pm_owner == NULL, 2057 ("[pmc,%d] destroying pmc attached to an owner", __LINE__)); 2058 KASSERT(pm->pm_runcount == 0, 2059 ("[pmc,%d] pmc has non-zero run count %d", __LINE__, 2060 pm->pm_runcount)); 2061 #endif 2062 } 2063 2064 static void 2065 pmc_wait_for_pmc_idle(struct pmc *pm) 2066 { 2067 #ifdef DEBUG 2068 volatile int maxloop; 2069 2070 maxloop = 100 * pmc_cpu_max(); 2071 #endif 2072 2073 /* 2074 * Loop (with a forced context switch) till the PMC's runcount 2075 * comes down to zero. 2076 */ 2077 while (atomic_load_acq_32(&pm->pm_runcount) > 0) { 2078 #ifdef DEBUG 2079 maxloop--; 2080 KASSERT(maxloop > 0, 2081 ("[pmc,%d] (ri%d, rc%d) waiting too long for " 2082 "pmc to be free", __LINE__, 2083 PMC_TO_ROWINDEX(pm), pm->pm_runcount)); 2084 #endif 2085 pmc_force_context_switch(); 2086 } 2087 } 2088 2089 /* 2090 * This function does the following things: 2091 * 2092 * - detaches the PMC from hardware 2093 * - unlinks all target threads that were attached to it 2094 * - removes the PMC from its owner's list 2095 * - destroy's the PMC private mutex 2096 * 2097 * Once this function completes, the given pmc pointer can be safely 2098 * FREE'd by the caller. 2099 */ 2100 2101 static void 2102 pmc_release_pmc_descriptor(struct pmc *pm) 2103 { 2104 enum pmc_mode mode; 2105 struct pmc_hw *phw; 2106 u_int adjri, ri, cpu; 2107 struct pmc_owner *po; 2108 struct pmc_binding pb; 2109 struct pmc_process *pp; 2110 struct pmc_classdep *pcd; 2111 struct pmc_target *ptgt, *tmp; 2112 2113 sx_assert(&pmc_sx, SX_XLOCKED); 2114 2115 KASSERT(pm, ("[pmc,%d] null pmc", __LINE__)); 2116 2117 ri = PMC_TO_ROWINDEX(pm); 2118 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2119 mode = PMC_TO_MODE(pm); 2120 2121 PMCDBG(PMC,REL,1, "release-pmc pmc=%p ri=%d mode=%d", pm, ri, 2122 mode); 2123 2124 /* 2125 * First, we take the PMC off hardware. 2126 */ 2127 cpu = 0; 2128 if (PMC_IS_SYSTEM_MODE(mode)) { 2129 2130 /* 2131 * A system mode PMC runs on a specific CPU. Switch 2132 * to this CPU and turn hardware off. 2133 */ 2134 pmc_save_cpu_binding(&pb); 2135 2136 cpu = PMC_TO_CPU(pm); 2137 2138 pmc_select_cpu(cpu); 2139 2140 /* switch off non-stalled CPUs */ 2141 if (pm->pm_state == PMC_STATE_RUNNING && 2142 pm->pm_stalled == 0) { 2143 2144 phw = pmc_pcpu[cpu]->pc_hwpmcs[ri]; 2145 2146 KASSERT(phw->phw_pmc == pm, 2147 ("[pmc, %d] pmc ptr ri(%d) hw(%p) pm(%p)", 2148 __LINE__, ri, phw->phw_pmc, pm)); 2149 PMCDBG(PMC,REL,2, "stopping cpu=%d ri=%d", cpu, ri); 2150 2151 critical_enter(); 2152 pcd->pcd_stop_pmc(cpu, adjri); 2153 critical_exit(); 2154 } 2155 2156 PMCDBG(PMC,REL,2, "decfg cpu=%d ri=%d", cpu, ri); 2157 2158 critical_enter(); 2159 pcd->pcd_config_pmc(cpu, adjri, NULL); 2160 critical_exit(); 2161 2162 /* adjust the global and process count of SS mode PMCs */ 2163 if (mode == PMC_MODE_SS && pm->pm_state == PMC_STATE_RUNNING) { 2164 po = pm->pm_owner; 2165 po->po_sscount--; 2166 if (po->po_sscount == 0) { 2167 atomic_subtract_rel_int(&pmc_ss_count, 1); 2168 LIST_REMOVE(po, po_ssnext); 2169 } 2170 } 2171 2172 pm->pm_state = PMC_STATE_DELETED; 2173 2174 pmc_restore_cpu_binding(&pb); 2175 2176 /* 2177 * We could have references to this PMC structure in 2178 * the per-cpu sample queues. Wait for the queue to 2179 * drain. 2180 */ 2181 pmc_wait_for_pmc_idle(pm); 2182 2183 } else if (PMC_IS_VIRTUAL_MODE(mode)) { 2184 2185 /* 2186 * A virtual PMC could be running on multiple CPUs at 2187 * a given instant. 2188 * 2189 * By marking its state as DELETED, we ensure that 2190 * this PMC is never further scheduled on hardware. 2191 * 2192 * Then we wait till all CPUs are done with this PMC. 2193 */ 2194 pm->pm_state = PMC_STATE_DELETED; 2195 2196 2197 /* Wait for the PMCs runcount to come to zero. */ 2198 pmc_wait_for_pmc_idle(pm); 2199 2200 /* 2201 * At this point the PMC is off all CPUs and cannot be 2202 * freshly scheduled onto a CPU. It is now safe to 2203 * unlink all targets from this PMC. If a 2204 * process-record's refcount falls to zero, we remove 2205 * it from the hash table. The module-wide SX lock 2206 * protects us from races. 2207 */ 2208 LIST_FOREACH_SAFE(ptgt, &pm->pm_targets, pt_next, tmp) { 2209 pp = ptgt->pt_process; 2210 pmc_unlink_target_process(pm, pp); /* frees 'ptgt' */ 2211 2212 PMCDBG(PMC,REL,3, "pp->refcnt=%d", pp->pp_refcnt); 2213 2214 /* 2215 * If the target process record shows that no 2216 * PMCs are attached to it, reclaim its space. 2217 */ 2218 2219 if (pp->pp_refcnt == 0) { 2220 pmc_remove_process_descriptor(pp); 2221 free(pp, M_PMC); 2222 } 2223 } 2224 2225 cpu = curthread->td_oncpu; /* setup cpu for pmd_release() */ 2226 2227 } 2228 2229 /* 2230 * Release any MD resources 2231 */ 2232 (void) pcd->pcd_release_pmc(cpu, adjri, pm); 2233 2234 /* 2235 * Update row disposition 2236 */ 2237 2238 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) 2239 PMC_UNMARK_ROW_STANDALONE(ri); 2240 else 2241 PMC_UNMARK_ROW_THREAD(ri); 2242 2243 /* unlink from the owner's list */ 2244 if (pm->pm_owner) { 2245 LIST_REMOVE(pm, pm_next); 2246 pm->pm_owner = NULL; 2247 } 2248 2249 pmc_destroy_pmc_descriptor(pm); 2250 } 2251 2252 /* 2253 * Register an owner and a pmc. 2254 */ 2255 2256 static int 2257 pmc_register_owner(struct proc *p, struct pmc *pmc) 2258 { 2259 struct pmc_owner *po; 2260 2261 sx_assert(&pmc_sx, SX_XLOCKED); 2262 2263 if ((po = pmc_find_owner_descriptor(p)) == NULL) 2264 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) 2265 return ENOMEM; 2266 2267 KASSERT(pmc->pm_owner == NULL, 2268 ("[pmc,%d] attempting to own an initialized PMC", __LINE__)); 2269 pmc->pm_owner = po; 2270 2271 LIST_INSERT_HEAD(&po->po_pmcs, pmc, pm_next); 2272 2273 PROC_LOCK(p); 2274 p->p_flag |= P_HWPMC; 2275 PROC_UNLOCK(p); 2276 2277 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 2278 pmclog_process_pmcallocate(pmc); 2279 2280 PMCDBG(PMC,REG,1, "register-owner pmc-owner=%p pmc=%p", 2281 po, pmc); 2282 2283 return 0; 2284 } 2285 2286 /* 2287 * Return the current row disposition: 2288 * == 0 => FREE 2289 * > 0 => PROCESS MODE 2290 * < 0 => SYSTEM MODE 2291 */ 2292 2293 int 2294 pmc_getrowdisp(int ri) 2295 { 2296 return pmc_pmcdisp[ri]; 2297 } 2298 2299 /* 2300 * Check if a PMC at row index 'ri' can be allocated to the current 2301 * process. 2302 * 2303 * Allocation can fail if: 2304 * - the current process is already being profiled by a PMC at index 'ri', 2305 * attached to it via OP_PMCATTACH. 2306 * - the current process has already allocated a PMC at index 'ri' 2307 * via OP_ALLOCATE. 2308 */ 2309 2310 static int 2311 pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, int cpu) 2312 { 2313 enum pmc_mode mode; 2314 struct pmc *pm; 2315 struct pmc_owner *po; 2316 struct pmc_process *pp; 2317 2318 PMCDBG(PMC,ALR,1, "can-allocate-rowindex proc=%p (%d, %s) ri=%d " 2319 "cpu=%d", p, p->p_pid, p->p_comm, ri, cpu); 2320 2321 /* 2322 * We shouldn't have already allocated a process-mode PMC at 2323 * row index 'ri'. 2324 * 2325 * We shouldn't have allocated a system-wide PMC on the same 2326 * CPU and same RI. 2327 */ 2328 if ((po = pmc_find_owner_descriptor(p)) != NULL) 2329 LIST_FOREACH(pm, &po->po_pmcs, pm_next) { 2330 if (PMC_TO_ROWINDEX(pm) == ri) { 2331 mode = PMC_TO_MODE(pm); 2332 if (PMC_IS_VIRTUAL_MODE(mode)) 2333 return EEXIST; 2334 if (PMC_IS_SYSTEM_MODE(mode) && 2335 (int) PMC_TO_CPU(pm) == cpu) 2336 return EEXIST; 2337 } 2338 } 2339 2340 /* 2341 * We also shouldn't be the target of any PMC at this index 2342 * since otherwise a PMC_ATTACH to ourselves will fail. 2343 */ 2344 if ((pp = pmc_find_process_descriptor(p, 0)) != NULL) 2345 if (pp->pp_pmcs[ri].pp_pmc) 2346 return EEXIST; 2347 2348 PMCDBG(PMC,ALR,2, "can-allocate-rowindex proc=%p (%d, %s) ri=%d ok", 2349 p, p->p_pid, p->p_comm, ri); 2350 2351 return 0; 2352 } 2353 2354 /* 2355 * Check if a given PMC at row index 'ri' can be currently used in 2356 * mode 'mode'. 2357 */ 2358 2359 static int 2360 pmc_can_allocate_row(int ri, enum pmc_mode mode) 2361 { 2362 enum pmc_disp disp; 2363 2364 sx_assert(&pmc_sx, SX_XLOCKED); 2365 2366 PMCDBG(PMC,ALR,1, "can-allocate-row ri=%d mode=%d", ri, mode); 2367 2368 if (PMC_IS_SYSTEM_MODE(mode)) 2369 disp = PMC_DISP_STANDALONE; 2370 else 2371 disp = PMC_DISP_THREAD; 2372 2373 /* 2374 * check disposition for PMC row 'ri': 2375 * 2376 * Expected disposition Row-disposition Result 2377 * 2378 * STANDALONE STANDALONE or FREE proceed 2379 * STANDALONE THREAD fail 2380 * THREAD THREAD or FREE proceed 2381 * THREAD STANDALONE fail 2382 */ 2383 2384 if (!PMC_ROW_DISP_IS_FREE(ri) && 2385 !(disp == PMC_DISP_THREAD && PMC_ROW_DISP_IS_THREAD(ri)) && 2386 !(disp == PMC_DISP_STANDALONE && PMC_ROW_DISP_IS_STANDALONE(ri))) 2387 return EBUSY; 2388 2389 /* 2390 * All OK 2391 */ 2392 2393 PMCDBG(PMC,ALR,2, "can-allocate-row ri=%d mode=%d ok", ri, mode); 2394 2395 return 0; 2396 2397 } 2398 2399 /* 2400 * Find a PMC descriptor with user handle 'pmcid' for thread 'td'. 2401 */ 2402 2403 static struct pmc * 2404 pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, pmc_id_t pmcid) 2405 { 2406 struct pmc *pm; 2407 2408 KASSERT(PMC_ID_TO_ROWINDEX(pmcid) < md->pmd_npmc, 2409 ("[pmc,%d] Illegal pmc index %d (max %d)", __LINE__, 2410 PMC_ID_TO_ROWINDEX(pmcid), md->pmd_npmc)); 2411 2412 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 2413 if (pm->pm_id == pmcid) 2414 return pm; 2415 2416 return NULL; 2417 } 2418 2419 static int 2420 pmc_find_pmc(pmc_id_t pmcid, struct pmc **pmc) 2421 { 2422 2423 struct pmc *pm; 2424 struct pmc_owner *po; 2425 2426 PMCDBG(PMC,FND,1, "find-pmc id=%d", pmcid); 2427 2428 if ((po = pmc_find_owner_descriptor(curthread->td_proc)) == NULL) 2429 return ESRCH; 2430 2431 if ((pm = pmc_find_pmc_descriptor_in_process(po, pmcid)) == NULL) 2432 return EINVAL; 2433 2434 PMCDBG(PMC,FND,2, "find-pmc id=%d -> pmc=%p", pmcid, pm); 2435 2436 *pmc = pm; 2437 return 0; 2438 } 2439 2440 /* 2441 * Start a PMC. 2442 */ 2443 2444 static int 2445 pmc_start(struct pmc *pm) 2446 { 2447 enum pmc_mode mode; 2448 struct pmc_owner *po; 2449 struct pmc_binding pb; 2450 struct pmc_classdep *pcd; 2451 int adjri, error, cpu, ri; 2452 2453 KASSERT(pm != NULL, 2454 ("[pmc,%d] null pm", __LINE__)); 2455 2456 mode = PMC_TO_MODE(pm); 2457 ri = PMC_TO_ROWINDEX(pm); 2458 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2459 2460 error = 0; 2461 2462 PMCDBG(PMC,OPS,1, "start pmc=%p mode=%d ri=%d", pm, mode, ri); 2463 2464 po = pm->pm_owner; 2465 2466 /* 2467 * Disallow PMCSTART if a logfile is required but has not been 2468 * configured yet. 2469 */ 2470 if ((pm->pm_flags & PMC_F_NEEDS_LOGFILE) && 2471 (po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) 2472 return (EDOOFUS); /* programming error */ 2473 2474 /* 2475 * If this is a sampling mode PMC, log mapping information for 2476 * the kernel modules that are currently loaded. 2477 */ 2478 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 2479 pmc_log_kernel_mappings(pm); 2480 2481 if (PMC_IS_VIRTUAL_MODE(mode)) { 2482 2483 /* 2484 * If a PMCATTACH has never been done on this PMC, 2485 * attach it to its owner process. 2486 */ 2487 2488 if (LIST_EMPTY(&pm->pm_targets)) 2489 error = (pm->pm_flags & PMC_F_ATTACH_DONE) ? ESRCH : 2490 pmc_attach_process(po->po_owner, pm); 2491 2492 /* 2493 * If the PMC is attached to its owner, then force a context 2494 * switch to ensure that the MD state gets set correctly. 2495 */ 2496 2497 if (error == 0) { 2498 pm->pm_state = PMC_STATE_RUNNING; 2499 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) 2500 pmc_force_context_switch(); 2501 } 2502 2503 return (error); 2504 } 2505 2506 2507 /* 2508 * A system-wide PMC. 2509 * 2510 * Add the owner to the global list if this is a system-wide 2511 * sampling PMC. 2512 */ 2513 2514 if (mode == PMC_MODE_SS) { 2515 if (po->po_sscount == 0) { 2516 LIST_INSERT_HEAD(&pmc_ss_owners, po, po_ssnext); 2517 atomic_add_rel_int(&pmc_ss_count, 1); 2518 PMCDBG(PMC,OPS,1, "po=%p in global list", po); 2519 } 2520 po->po_sscount++; 2521 } 2522 2523 /* Log mapping information for all processes in the system. */ 2524 pmc_log_all_process_mappings(po); 2525 2526 /* 2527 * Move to the CPU associated with this 2528 * PMC, and start the hardware. 2529 */ 2530 2531 pmc_save_cpu_binding(&pb); 2532 2533 cpu = PMC_TO_CPU(pm); 2534 2535 if (!pmc_cpu_is_active(cpu)) 2536 return (ENXIO); 2537 2538 pmc_select_cpu(cpu); 2539 2540 /* 2541 * global PMCs are configured at allocation time 2542 * so write out the initial value and start the PMC. 2543 */ 2544 2545 pm->pm_state = PMC_STATE_RUNNING; 2546 2547 critical_enter(); 2548 if ((error = pcd->pcd_write_pmc(cpu, adjri, 2549 PMC_IS_SAMPLING_MODE(mode) ? 2550 pm->pm_sc.pm_reloadcount : 2551 pm->pm_sc.pm_initial)) == 0) 2552 error = pcd->pcd_start_pmc(cpu, adjri); 2553 critical_exit(); 2554 2555 pmc_restore_cpu_binding(&pb); 2556 2557 return (error); 2558 } 2559 2560 /* 2561 * Stop a PMC. 2562 */ 2563 2564 static int 2565 pmc_stop(struct pmc *pm) 2566 { 2567 struct pmc_owner *po; 2568 struct pmc_binding pb; 2569 struct pmc_classdep *pcd; 2570 int adjri, cpu, error, ri; 2571 2572 KASSERT(pm != NULL, ("[pmc,%d] null pmc", __LINE__)); 2573 2574 PMCDBG(PMC,OPS,1, "stop pmc=%p mode=%d ri=%d", pm, 2575 PMC_TO_MODE(pm), PMC_TO_ROWINDEX(pm)); 2576 2577 pm->pm_state = PMC_STATE_STOPPED; 2578 2579 /* 2580 * If the PMC is a virtual mode one, changing the state to 2581 * non-RUNNING is enough to ensure that the PMC never gets 2582 * scheduled. 2583 * 2584 * If this PMC is current running on a CPU, then it will 2585 * handled correctly at the time its target process is context 2586 * switched out. 2587 */ 2588 2589 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 2590 return 0; 2591 2592 /* 2593 * A system-mode PMC. Move to the CPU associated with 2594 * this PMC, and stop the hardware. We update the 2595 * 'initial count' so that a subsequent PMCSTART will 2596 * resume counting from the current hardware count. 2597 */ 2598 2599 pmc_save_cpu_binding(&pb); 2600 2601 cpu = PMC_TO_CPU(pm); 2602 2603 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 2604 ("[pmc,%d] illegal cpu=%d", __LINE__, cpu)); 2605 2606 if (!pmc_cpu_is_active(cpu)) 2607 return ENXIO; 2608 2609 pmc_select_cpu(cpu); 2610 2611 ri = PMC_TO_ROWINDEX(pm); 2612 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2613 2614 critical_enter(); 2615 if ((error = pcd->pcd_stop_pmc(cpu, adjri)) == 0) 2616 error = pcd->pcd_read_pmc(cpu, adjri, &pm->pm_sc.pm_initial); 2617 critical_exit(); 2618 2619 pmc_restore_cpu_binding(&pb); 2620 2621 po = pm->pm_owner; 2622 2623 /* remove this owner from the global list of SS PMC owners */ 2624 if (PMC_TO_MODE(pm) == PMC_MODE_SS) { 2625 po->po_sscount--; 2626 if (po->po_sscount == 0) { 2627 atomic_subtract_rel_int(&pmc_ss_count, 1); 2628 LIST_REMOVE(po, po_ssnext); 2629 PMCDBG(PMC,OPS,2,"po=%p removed from global list", po); 2630 } 2631 } 2632 2633 return (error); 2634 } 2635 2636 2637 #ifdef DEBUG 2638 static const char *pmc_op_to_name[] = { 2639 #undef __PMC_OP 2640 #define __PMC_OP(N, D) #N , 2641 __PMC_OPS() 2642 NULL 2643 }; 2644 #endif 2645 2646 /* 2647 * The syscall interface 2648 */ 2649 2650 #define PMC_GET_SX_XLOCK(...) do { \ 2651 sx_xlock(&pmc_sx); \ 2652 if (pmc_hook == NULL) { \ 2653 sx_xunlock(&pmc_sx); \ 2654 return __VA_ARGS__; \ 2655 } \ 2656 } while (0) 2657 2658 #define PMC_DOWNGRADE_SX() do { \ 2659 sx_downgrade(&pmc_sx); \ 2660 is_sx_downgraded = 1; \ 2661 } while (0) 2662 2663 static int 2664 pmc_syscall_handler(struct thread *td, void *syscall_args) 2665 { 2666 int error, is_sx_downgraded, is_sx_locked, op; 2667 struct pmc_syscall_args *c; 2668 void *arg; 2669 2670 PMC_GET_SX_XLOCK(ENOSYS); 2671 2672 DROP_GIANT(); 2673 2674 is_sx_downgraded = 0; 2675 is_sx_locked = 1; 2676 2677 c = (struct pmc_syscall_args *) syscall_args; 2678 2679 op = c->pmop_code; 2680 arg = c->pmop_data; 2681 2682 PMCDBG(MOD,PMS,1, "syscall op=%d \"%s\" arg=%p", op, 2683 pmc_op_to_name[op], arg); 2684 2685 error = 0; 2686 atomic_add_int(&pmc_stats.pm_syscalls, 1); 2687 2688 switch(op) 2689 { 2690 2691 2692 /* 2693 * Configure a log file. 2694 * 2695 * XXX This OP will be reworked. 2696 */ 2697 2698 case PMC_OP_CONFIGURELOG: 2699 { 2700 struct proc *p; 2701 struct pmc *pm; 2702 struct pmc_owner *po; 2703 struct pmc_op_configurelog cl; 2704 2705 sx_assert(&pmc_sx, SX_XLOCKED); 2706 2707 if ((error = copyin(arg, &cl, sizeof(cl))) != 0) 2708 break; 2709 2710 /* mark this process as owning a log file */ 2711 p = td->td_proc; 2712 if ((po = pmc_find_owner_descriptor(p)) == NULL) 2713 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) { 2714 error = ENOMEM; 2715 break; 2716 } 2717 2718 /* 2719 * If a valid fd was passed in, try to configure that, 2720 * otherwise if 'fd' was less than zero and there was 2721 * a log file configured, flush its buffers and 2722 * de-configure it. 2723 */ 2724 if (cl.pm_logfd >= 0) { 2725 sx_xunlock(&pmc_sx); 2726 is_sx_locked = 0; 2727 error = pmclog_configure_log(md, po, cl.pm_logfd); 2728 } else if (po->po_flags & PMC_PO_OWNS_LOGFILE) { 2729 pmclog_process_closelog(po); 2730 error = pmclog_flush(po); 2731 if (error == 0) { 2732 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 2733 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 2734 pm->pm_state == PMC_STATE_RUNNING) 2735 pmc_stop(pm); 2736 error = pmclog_deconfigure_log(po); 2737 } 2738 } else 2739 error = EINVAL; 2740 2741 if (error) 2742 break; 2743 } 2744 break; 2745 2746 2747 /* 2748 * Flush a log file. 2749 */ 2750 2751 case PMC_OP_FLUSHLOG: 2752 { 2753 struct pmc_owner *po; 2754 2755 sx_assert(&pmc_sx, SX_XLOCKED); 2756 2757 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 2758 error = EINVAL; 2759 break; 2760 } 2761 2762 error = pmclog_flush(po); 2763 } 2764 break; 2765 2766 /* 2767 * Retrieve hardware configuration. 2768 */ 2769 2770 case PMC_OP_GETCPUINFO: /* CPU information */ 2771 { 2772 struct pmc_op_getcpuinfo gci; 2773 struct pmc_classinfo *pci; 2774 struct pmc_classdep *pcd; 2775 int cl; 2776 2777 gci.pm_cputype = md->pmd_cputype; 2778 gci.pm_ncpu = pmc_cpu_max(); 2779 gci.pm_npmc = md->pmd_npmc; 2780 gci.pm_nclass = md->pmd_nclass; 2781 pci = gci.pm_classes; 2782 pcd = md->pmd_classdep; 2783 for (cl = 0; cl < md->pmd_nclass; cl++, pci++, pcd++) { 2784 pci->pm_caps = pcd->pcd_caps; 2785 pci->pm_class = pcd->pcd_class; 2786 pci->pm_width = pcd->pcd_width; 2787 pci->pm_num = pcd->pcd_num; 2788 } 2789 error = copyout(&gci, arg, sizeof(gci)); 2790 } 2791 break; 2792 2793 2794 /* 2795 * Get module statistics 2796 */ 2797 2798 case PMC_OP_GETDRIVERSTATS: 2799 { 2800 struct pmc_op_getdriverstats gms; 2801 2802 bcopy(&pmc_stats, &gms, sizeof(gms)); 2803 error = copyout(&gms, arg, sizeof(gms)); 2804 } 2805 break; 2806 2807 2808 /* 2809 * Retrieve module version number 2810 */ 2811 2812 case PMC_OP_GETMODULEVERSION: 2813 { 2814 uint32_t cv, modv; 2815 2816 /* retrieve the client's idea of the ABI version */ 2817 if ((error = copyin(arg, &cv, sizeof(uint32_t))) != 0) 2818 break; 2819 /* don't service clients newer than our driver */ 2820 modv = PMC_VERSION; 2821 if ((cv & 0xFFFF0000) > (modv & 0xFFFF0000)) { 2822 error = EPROGMISMATCH; 2823 break; 2824 } 2825 error = copyout(&modv, arg, sizeof(int)); 2826 } 2827 break; 2828 2829 2830 /* 2831 * Retrieve the state of all the PMCs on a given 2832 * CPU. 2833 */ 2834 2835 case PMC_OP_GETPMCINFO: 2836 { 2837 int ari; 2838 struct pmc *pm; 2839 size_t pmcinfo_size; 2840 uint32_t cpu, n, npmc; 2841 struct pmc_owner *po; 2842 struct pmc_binding pb; 2843 struct pmc_classdep *pcd; 2844 struct pmc_info *p, *pmcinfo; 2845 struct pmc_op_getpmcinfo *gpi; 2846 2847 PMC_DOWNGRADE_SX(); 2848 2849 gpi = (struct pmc_op_getpmcinfo *) arg; 2850 2851 if ((error = copyin(&gpi->pm_cpu, &cpu, sizeof(cpu))) != 0) 2852 break; 2853 2854 if (cpu >= pmc_cpu_max()) { 2855 error = EINVAL; 2856 break; 2857 } 2858 2859 if (!pmc_cpu_is_active(cpu)) { 2860 error = ENXIO; 2861 break; 2862 } 2863 2864 /* switch to CPU 'cpu' */ 2865 pmc_save_cpu_binding(&pb); 2866 pmc_select_cpu(cpu); 2867 2868 npmc = md->pmd_npmc; 2869 2870 pmcinfo_size = npmc * sizeof(struct pmc_info); 2871 pmcinfo = malloc(pmcinfo_size, M_PMC, M_WAITOK); 2872 2873 p = pmcinfo; 2874 2875 for (n = 0; n < md->pmd_npmc; n++, p++) { 2876 2877 pcd = pmc_ri_to_classdep(md, n, &ari); 2878 2879 KASSERT(pcd != NULL, 2880 ("[pmc,%d] null pcd ri=%d", __LINE__, n)); 2881 2882 if ((error = pcd->pcd_describe(cpu, ari, p, &pm)) != 0) 2883 break; 2884 2885 if (PMC_ROW_DISP_IS_STANDALONE(n)) 2886 p->pm_rowdisp = PMC_DISP_STANDALONE; 2887 else if (PMC_ROW_DISP_IS_THREAD(n)) 2888 p->pm_rowdisp = PMC_DISP_THREAD; 2889 else 2890 p->pm_rowdisp = PMC_DISP_FREE; 2891 2892 p->pm_ownerpid = -1; 2893 2894 if (pm == NULL) /* no PMC associated */ 2895 continue; 2896 2897 po = pm->pm_owner; 2898 2899 KASSERT(po->po_owner != NULL, 2900 ("[pmc,%d] pmc_owner had a null proc pointer", 2901 __LINE__)); 2902 2903 p->pm_ownerpid = po->po_owner->p_pid; 2904 p->pm_mode = PMC_TO_MODE(pm); 2905 p->pm_event = pm->pm_event; 2906 p->pm_flags = pm->pm_flags; 2907 2908 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 2909 p->pm_reloadcount = 2910 pm->pm_sc.pm_reloadcount; 2911 } 2912 2913 pmc_restore_cpu_binding(&pb); 2914 2915 /* now copy out the PMC info collected */ 2916 if (error == 0) 2917 error = copyout(pmcinfo, &gpi->pm_pmcs, pmcinfo_size); 2918 2919 free(pmcinfo, M_PMC); 2920 } 2921 break; 2922 2923 2924 /* 2925 * Set the administrative state of a PMC. I.e. whether 2926 * the PMC is to be used or not. 2927 */ 2928 2929 case PMC_OP_PMCADMIN: 2930 { 2931 int cpu, ri; 2932 enum pmc_state request; 2933 struct pmc_cpu *pc; 2934 struct pmc_hw *phw; 2935 struct pmc_op_pmcadmin pma; 2936 struct pmc_binding pb; 2937 2938 sx_assert(&pmc_sx, SX_XLOCKED); 2939 2940 KASSERT(td == curthread, 2941 ("[pmc,%d] td != curthread", __LINE__)); 2942 2943 error = priv_check(td, PRIV_PMC_MANAGE); 2944 if (error) 2945 break; 2946 2947 if ((error = copyin(arg, &pma, sizeof(pma))) != 0) 2948 break; 2949 2950 cpu = pma.pm_cpu; 2951 2952 if (cpu < 0 || cpu >= (int) pmc_cpu_max()) { 2953 error = EINVAL; 2954 break; 2955 } 2956 2957 if (!pmc_cpu_is_active(cpu)) { 2958 error = ENXIO; 2959 break; 2960 } 2961 2962 request = pma.pm_state; 2963 2964 if (request != PMC_STATE_DISABLED && 2965 request != PMC_STATE_FREE) { 2966 error = EINVAL; 2967 break; 2968 } 2969 2970 ri = pma.pm_pmc; /* pmc id == row index */ 2971 if (ri < 0 || ri >= (int) md->pmd_npmc) { 2972 error = EINVAL; 2973 break; 2974 } 2975 2976 /* 2977 * We can't disable a PMC with a row-index allocated 2978 * for process virtual PMCs. 2979 */ 2980 2981 if (PMC_ROW_DISP_IS_THREAD(ri) && 2982 request == PMC_STATE_DISABLED) { 2983 error = EBUSY; 2984 break; 2985 } 2986 2987 /* 2988 * otherwise, this PMC on this CPU is either free or 2989 * in system-wide mode. 2990 */ 2991 2992 pmc_save_cpu_binding(&pb); 2993 pmc_select_cpu(cpu); 2994 2995 pc = pmc_pcpu[cpu]; 2996 phw = pc->pc_hwpmcs[ri]; 2997 2998 /* 2999 * XXX do we need some kind of 'forced' disable? 3000 */ 3001 3002 if (phw->phw_pmc == NULL) { 3003 if (request == PMC_STATE_DISABLED && 3004 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED)) { 3005 phw->phw_state &= ~PMC_PHW_FLAG_IS_ENABLED; 3006 PMC_MARK_ROW_STANDALONE(ri); 3007 } else if (request == PMC_STATE_FREE && 3008 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0) { 3009 phw->phw_state |= PMC_PHW_FLAG_IS_ENABLED; 3010 PMC_UNMARK_ROW_STANDALONE(ri); 3011 } 3012 /* other cases are a no-op */ 3013 } else 3014 error = EBUSY; 3015 3016 pmc_restore_cpu_binding(&pb); 3017 } 3018 break; 3019 3020 3021 /* 3022 * Allocate a PMC. 3023 */ 3024 3025 case PMC_OP_PMCALLOCATE: 3026 { 3027 int adjri, n; 3028 u_int cpu; 3029 uint32_t caps; 3030 struct pmc *pmc; 3031 enum pmc_mode mode; 3032 struct pmc_hw *phw; 3033 struct pmc_binding pb; 3034 struct pmc_classdep *pcd; 3035 struct pmc_op_pmcallocate pa; 3036 3037 if ((error = copyin(arg, &pa, sizeof(pa))) != 0) 3038 break; 3039 3040 caps = pa.pm_caps; 3041 mode = pa.pm_mode; 3042 cpu = pa.pm_cpu; 3043 3044 if ((mode != PMC_MODE_SS && mode != PMC_MODE_SC && 3045 mode != PMC_MODE_TS && mode != PMC_MODE_TC) || 3046 (cpu != (u_int) PMC_CPU_ANY && cpu >= pmc_cpu_max())) { 3047 error = EINVAL; 3048 break; 3049 } 3050 3051 /* 3052 * Virtual PMCs should only ask for a default CPU. 3053 * System mode PMCs need to specify a non-default CPU. 3054 */ 3055 3056 if ((PMC_IS_VIRTUAL_MODE(mode) && cpu != (u_int) PMC_CPU_ANY) || 3057 (PMC_IS_SYSTEM_MODE(mode) && cpu == (u_int) PMC_CPU_ANY)) { 3058 error = EINVAL; 3059 break; 3060 } 3061 3062 /* 3063 * Check that an inactive CPU is not being asked for. 3064 */ 3065 3066 if (PMC_IS_SYSTEM_MODE(mode) && !pmc_cpu_is_active(cpu)) { 3067 error = ENXIO; 3068 break; 3069 } 3070 3071 /* 3072 * Refuse an allocation for a system-wide PMC if this 3073 * process has been jailed, or if this process lacks 3074 * super-user credentials and the sysctl tunable 3075 * 'security.bsd.unprivileged_syspmcs' is zero. 3076 */ 3077 3078 if (PMC_IS_SYSTEM_MODE(mode)) { 3079 if (jailed(curthread->td_ucred)) { 3080 error = EPERM; 3081 break; 3082 } 3083 if (!pmc_unprivileged_syspmcs) { 3084 error = priv_check(curthread, 3085 PRIV_PMC_SYSTEM); 3086 if (error) 3087 break; 3088 } 3089 } 3090 3091 if (error) 3092 break; 3093 3094 /* 3095 * Look for valid values for 'pm_flags' 3096 */ 3097 3098 if ((pa.pm_flags & ~(PMC_F_DESCENDANTS | PMC_F_LOG_PROCCSW | 3099 PMC_F_LOG_PROCEXIT | PMC_F_CALLCHAIN)) != 0) { 3100 error = EINVAL; 3101 break; 3102 } 3103 3104 /* process logging options are not allowed for system PMCs */ 3105 if (PMC_IS_SYSTEM_MODE(mode) && (pa.pm_flags & 3106 (PMC_F_LOG_PROCCSW | PMC_F_LOG_PROCEXIT))) { 3107 error = EINVAL; 3108 break; 3109 } 3110 3111 /* 3112 * All sampling mode PMCs need to be able to interrupt the 3113 * CPU. 3114 */ 3115 if (PMC_IS_SAMPLING_MODE(mode)) 3116 caps |= PMC_CAP_INTERRUPT; 3117 3118 /* A valid class specifier should have been passed in. */ 3119 for (n = 0; n < md->pmd_nclass; n++) 3120 if (md->pmd_classdep[n].pcd_class == pa.pm_class) 3121 break; 3122 if (n == md->pmd_nclass) { 3123 error = EINVAL; 3124 break; 3125 } 3126 3127 /* The requested PMC capabilities should be feasible. */ 3128 if ((md->pmd_classdep[n].pcd_caps & caps) != caps) { 3129 error = EOPNOTSUPP; 3130 break; 3131 } 3132 3133 PMCDBG(PMC,ALL,2, "event=%d caps=0x%x mode=%d cpu=%d", 3134 pa.pm_ev, caps, mode, cpu); 3135 3136 pmc = pmc_allocate_pmc_descriptor(); 3137 pmc->pm_id = PMC_ID_MAKE_ID(cpu,pa.pm_mode,pa.pm_class, 3138 PMC_ID_INVALID); 3139 pmc->pm_event = pa.pm_ev; 3140 pmc->pm_state = PMC_STATE_FREE; 3141 pmc->pm_caps = caps; 3142 pmc->pm_flags = pa.pm_flags; 3143 3144 /* switch thread to CPU 'cpu' */ 3145 pmc_save_cpu_binding(&pb); 3146 3147 #define PMC_IS_SHAREABLE_PMC(cpu, n) \ 3148 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_state & \ 3149 PMC_PHW_FLAG_IS_SHAREABLE) 3150 #define PMC_IS_UNALLOCATED(cpu, n) \ 3151 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_pmc == NULL) 3152 3153 if (PMC_IS_SYSTEM_MODE(mode)) { 3154 pmc_select_cpu(cpu); 3155 for (n = 0; n < (int) md->pmd_npmc; n++) { 3156 pcd = pmc_ri_to_classdep(md, n, &adjri); 3157 if (pmc_can_allocate_row(n, mode) == 0 && 3158 pmc_can_allocate_rowindex( 3159 curthread->td_proc, n, cpu) == 0 && 3160 (PMC_IS_UNALLOCATED(cpu, n) || 3161 PMC_IS_SHAREABLE_PMC(cpu, n)) && 3162 pcd->pcd_allocate_pmc(cpu, adjri, pmc, 3163 &pa) == 0) 3164 break; 3165 } 3166 } else { 3167 /* Process virtual mode */ 3168 for (n = 0; n < (int) md->pmd_npmc; n++) { 3169 pcd = pmc_ri_to_classdep(md, n, &adjri); 3170 if (pmc_can_allocate_row(n, mode) == 0 && 3171 pmc_can_allocate_rowindex( 3172 curthread->td_proc, n, 3173 PMC_CPU_ANY) == 0 && 3174 pcd->pcd_allocate_pmc(curthread->td_oncpu, 3175 adjri, pmc, &pa) == 0) 3176 break; 3177 } 3178 } 3179 3180 #undef PMC_IS_UNALLOCATED 3181 #undef PMC_IS_SHAREABLE_PMC 3182 3183 pmc_restore_cpu_binding(&pb); 3184 3185 if (n == (int) md->pmd_npmc) { 3186 pmc_destroy_pmc_descriptor(pmc); 3187 free(pmc, M_PMC); 3188 pmc = NULL; 3189 error = EINVAL; 3190 break; 3191 } 3192 3193 /* Fill in the correct value in the ID field */ 3194 pmc->pm_id = PMC_ID_MAKE_ID(cpu,mode,pa.pm_class,n); 3195 3196 PMCDBG(PMC,ALL,2, "ev=%d class=%d mode=%d n=%d -> pmcid=%x", 3197 pmc->pm_event, pa.pm_class, mode, n, pmc->pm_id); 3198 3199 /* Process mode PMCs with logging enabled need log files */ 3200 if (pmc->pm_flags & (PMC_F_LOG_PROCEXIT | PMC_F_LOG_PROCCSW)) 3201 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3202 3203 /* All system mode sampling PMCs require a log file */ 3204 if (PMC_IS_SAMPLING_MODE(mode) && PMC_IS_SYSTEM_MODE(mode)) 3205 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3206 3207 /* 3208 * Configure global pmc's immediately 3209 */ 3210 3211 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pmc))) { 3212 3213 pmc_save_cpu_binding(&pb); 3214 pmc_select_cpu(cpu); 3215 3216 phw = pmc_pcpu[cpu]->pc_hwpmcs[n]; 3217 pcd = pmc_ri_to_classdep(md, n, &adjri); 3218 3219 if ((phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0 || 3220 (error = pcd->pcd_config_pmc(cpu, adjri, pmc)) != 0) { 3221 (void) pcd->pcd_release_pmc(cpu, adjri, pmc); 3222 pmc_destroy_pmc_descriptor(pmc); 3223 free(pmc, M_PMC); 3224 pmc = NULL; 3225 pmc_restore_cpu_binding(&pb); 3226 error = EPERM; 3227 break; 3228 } 3229 3230 pmc_restore_cpu_binding(&pb); 3231 } 3232 3233 pmc->pm_state = PMC_STATE_ALLOCATED; 3234 3235 /* 3236 * mark row disposition 3237 */ 3238 3239 if (PMC_IS_SYSTEM_MODE(mode)) 3240 PMC_MARK_ROW_STANDALONE(n); 3241 else 3242 PMC_MARK_ROW_THREAD(n); 3243 3244 /* 3245 * Register this PMC with the current thread as its owner. 3246 */ 3247 3248 if ((error = 3249 pmc_register_owner(curthread->td_proc, pmc)) != 0) { 3250 pmc_release_pmc_descriptor(pmc); 3251 free(pmc, M_PMC); 3252 pmc = NULL; 3253 break; 3254 } 3255 3256 /* 3257 * Return the allocated index. 3258 */ 3259 3260 pa.pm_pmcid = pmc->pm_id; 3261 3262 error = copyout(&pa, arg, sizeof(pa)); 3263 } 3264 break; 3265 3266 3267 /* 3268 * Attach a PMC to a process. 3269 */ 3270 3271 case PMC_OP_PMCATTACH: 3272 { 3273 struct pmc *pm; 3274 struct proc *p; 3275 struct pmc_op_pmcattach a; 3276 3277 sx_assert(&pmc_sx, SX_XLOCKED); 3278 3279 if ((error = copyin(arg, &a, sizeof(a))) != 0) 3280 break; 3281 3282 if (a.pm_pid < 0) { 3283 error = EINVAL; 3284 break; 3285 } else if (a.pm_pid == 0) 3286 a.pm_pid = td->td_proc->p_pid; 3287 3288 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 3289 break; 3290 3291 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) { 3292 error = EINVAL; 3293 break; 3294 } 3295 3296 /* PMCs may be (re)attached only when allocated or stopped */ 3297 if (pm->pm_state == PMC_STATE_RUNNING) { 3298 error = EBUSY; 3299 break; 3300 } else if (pm->pm_state != PMC_STATE_ALLOCATED && 3301 pm->pm_state != PMC_STATE_STOPPED) { 3302 error = EINVAL; 3303 break; 3304 } 3305 3306 /* lookup pid */ 3307 if ((p = pfind(a.pm_pid)) == NULL) { 3308 error = ESRCH; 3309 break; 3310 } 3311 3312 /* 3313 * Ignore processes that are working on exiting. 3314 */ 3315 if (p->p_flag & P_WEXIT) { 3316 error = ESRCH; 3317 PROC_UNLOCK(p); /* pfind() returns a locked process */ 3318 break; 3319 } 3320 3321 /* 3322 * we are allowed to attach a PMC to a process if 3323 * we can debug it. 3324 */ 3325 error = p_candebug(curthread, p); 3326 3327 PROC_UNLOCK(p); 3328 3329 if (error == 0) 3330 error = pmc_attach_process(p, pm); 3331 } 3332 break; 3333 3334 3335 /* 3336 * Detach an attached PMC from a process. 3337 */ 3338 3339 case PMC_OP_PMCDETACH: 3340 { 3341 struct pmc *pm; 3342 struct proc *p; 3343 struct pmc_op_pmcattach a; 3344 3345 if ((error = copyin(arg, &a, sizeof(a))) != 0) 3346 break; 3347 3348 if (a.pm_pid < 0) { 3349 error = EINVAL; 3350 break; 3351 } else if (a.pm_pid == 0) 3352 a.pm_pid = td->td_proc->p_pid; 3353 3354 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 3355 break; 3356 3357 if ((p = pfind(a.pm_pid)) == NULL) { 3358 error = ESRCH; 3359 break; 3360 } 3361 3362 /* 3363 * Treat processes that are in the process of exiting 3364 * as if they were not present. 3365 */ 3366 3367 if (p->p_flag & P_WEXIT) 3368 error = ESRCH; 3369 3370 PROC_UNLOCK(p); /* pfind() returns a locked process */ 3371 3372 if (error == 0) 3373 error = pmc_detach_process(p, pm); 3374 } 3375 break; 3376 3377 3378 /* 3379 * Retrieve the MSR number associated with the counter 3380 * 'pmc_id'. This allows processes to directly use RDPMC 3381 * instructions to read their PMCs, without the overhead of a 3382 * system call. 3383 */ 3384 3385 case PMC_OP_PMCGETMSR: 3386 { 3387 int adjri, ri; 3388 struct pmc *pm; 3389 struct pmc_target *pt; 3390 struct pmc_op_getmsr gm; 3391 struct pmc_classdep *pcd; 3392 3393 PMC_DOWNGRADE_SX(); 3394 3395 if ((error = copyin(arg, &gm, sizeof(gm))) != 0) 3396 break; 3397 3398 if ((error = pmc_find_pmc(gm.pm_pmcid, &pm)) != 0) 3399 break; 3400 3401 /* 3402 * The allocated PMC has to be a process virtual PMC, 3403 * i.e., of type MODE_T[CS]. Global PMCs can only be 3404 * read using the PMCREAD operation since they may be 3405 * allocated on a different CPU than the one we could 3406 * be running on at the time of the RDPMC instruction. 3407 * 3408 * The GETMSR operation is not allowed for PMCs that 3409 * are inherited across processes. 3410 */ 3411 3412 if (!PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)) || 3413 (pm->pm_flags & PMC_F_DESCENDANTS)) { 3414 error = EINVAL; 3415 break; 3416 } 3417 3418 /* 3419 * It only makes sense to use a RDPMC (or its 3420 * equivalent instruction on non-x86 architectures) on 3421 * a process that has allocated and attached a PMC to 3422 * itself. Conversely the PMC is only allowed to have 3423 * one process attached to it -- its owner. 3424 */ 3425 3426 if ((pt = LIST_FIRST(&pm->pm_targets)) == NULL || 3427 LIST_NEXT(pt, pt_next) != NULL || 3428 pt->pt_process->pp_proc != pm->pm_owner->po_owner) { 3429 error = EINVAL; 3430 break; 3431 } 3432 3433 ri = PMC_TO_ROWINDEX(pm); 3434 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3435 3436 /* PMC class has no 'GETMSR' support */ 3437 if (pcd->pcd_get_msr == NULL) { 3438 error = ENOSYS; 3439 break; 3440 } 3441 3442 if ((error = (*pcd->pcd_get_msr)(adjri, &gm.pm_msr)) < 0) 3443 break; 3444 3445 if ((error = copyout(&gm, arg, sizeof(gm))) < 0) 3446 break; 3447 3448 /* 3449 * Mark our process as using MSRs. Update machine 3450 * state using a forced context switch. 3451 */ 3452 3453 pt->pt_process->pp_flags |= PMC_PP_ENABLE_MSR_ACCESS; 3454 pmc_force_context_switch(); 3455 3456 } 3457 break; 3458 3459 /* 3460 * Release an allocated PMC 3461 */ 3462 3463 case PMC_OP_PMCRELEASE: 3464 { 3465 pmc_id_t pmcid; 3466 struct pmc *pm; 3467 struct pmc_owner *po; 3468 struct pmc_op_simple sp; 3469 3470 /* 3471 * Find PMC pointer for the named PMC. 3472 * 3473 * Use pmc_release_pmc_descriptor() to switch off the 3474 * PMC, remove all its target threads, and remove the 3475 * PMC from its owner's list. 3476 * 3477 * Remove the owner record if this is the last PMC 3478 * owned. 3479 * 3480 * Free up space. 3481 */ 3482 3483 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3484 break; 3485 3486 pmcid = sp.pm_pmcid; 3487 3488 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3489 break; 3490 3491 po = pm->pm_owner; 3492 pmc_release_pmc_descriptor(pm); 3493 pmc_maybe_remove_owner(po); 3494 3495 free(pm, M_PMC); 3496 } 3497 break; 3498 3499 3500 /* 3501 * Read and/or write a PMC. 3502 */ 3503 3504 case PMC_OP_PMCRW: 3505 { 3506 int adjri; 3507 struct pmc *pm; 3508 uint32_t cpu, ri; 3509 pmc_value_t oldvalue; 3510 struct pmc_binding pb; 3511 struct pmc_op_pmcrw prw; 3512 struct pmc_classdep *pcd; 3513 struct pmc_op_pmcrw *pprw; 3514 3515 PMC_DOWNGRADE_SX(); 3516 3517 if ((error = copyin(arg, &prw, sizeof(prw))) != 0) 3518 break; 3519 3520 ri = 0; 3521 PMCDBG(PMC,OPS,1, "rw id=%d flags=0x%x", prw.pm_pmcid, 3522 prw.pm_flags); 3523 3524 /* must have at least one flag set */ 3525 if ((prw.pm_flags & (PMC_F_OLDVALUE|PMC_F_NEWVALUE)) == 0) { 3526 error = EINVAL; 3527 break; 3528 } 3529 3530 /* locate pmc descriptor */ 3531 if ((error = pmc_find_pmc(prw.pm_pmcid, &pm)) != 0) 3532 break; 3533 3534 /* Can't read a PMC that hasn't been started. */ 3535 if (pm->pm_state != PMC_STATE_ALLOCATED && 3536 pm->pm_state != PMC_STATE_STOPPED && 3537 pm->pm_state != PMC_STATE_RUNNING) { 3538 error = EINVAL; 3539 break; 3540 } 3541 3542 /* writing a new value is allowed only for 'STOPPED' pmcs */ 3543 if (pm->pm_state == PMC_STATE_RUNNING && 3544 (prw.pm_flags & PMC_F_NEWVALUE)) { 3545 error = EBUSY; 3546 break; 3547 } 3548 3549 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) { 3550 3551 /* 3552 * If this PMC is attached to its owner (i.e., 3553 * the process requesting this operation) and 3554 * is running, then attempt to get an 3555 * upto-date reading from hardware for a READ. 3556 * Writes are only allowed when the PMC is 3557 * stopped, so only update the saved value 3558 * field. 3559 * 3560 * If the PMC is not running, or is not 3561 * attached to its owner, read/write to the 3562 * savedvalue field. 3563 */ 3564 3565 ri = PMC_TO_ROWINDEX(pm); 3566 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3567 3568 mtx_pool_lock_spin(pmc_mtxpool, pm); 3569 cpu = curthread->td_oncpu; 3570 3571 if (prw.pm_flags & PMC_F_OLDVALUE) { 3572 if ((pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) && 3573 (pm->pm_state == PMC_STATE_RUNNING)) 3574 error = (*pcd->pcd_read_pmc)(cpu, adjri, 3575 &oldvalue); 3576 else 3577 oldvalue = pm->pm_gv.pm_savedvalue; 3578 } 3579 if (prw.pm_flags & PMC_F_NEWVALUE) 3580 pm->pm_gv.pm_savedvalue = prw.pm_value; 3581 3582 mtx_pool_unlock_spin(pmc_mtxpool, pm); 3583 3584 } else { /* System mode PMCs */ 3585 cpu = PMC_TO_CPU(pm); 3586 ri = PMC_TO_ROWINDEX(pm); 3587 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3588 3589 if (!pmc_cpu_is_active(cpu)) { 3590 error = ENXIO; 3591 break; 3592 } 3593 3594 /* move this thread to CPU 'cpu' */ 3595 pmc_save_cpu_binding(&pb); 3596 pmc_select_cpu(cpu); 3597 3598 critical_enter(); 3599 /* save old value */ 3600 if (prw.pm_flags & PMC_F_OLDVALUE) 3601 if ((error = (*pcd->pcd_read_pmc)(cpu, adjri, 3602 &oldvalue))) 3603 goto error; 3604 /* write out new value */ 3605 if (prw.pm_flags & PMC_F_NEWVALUE) 3606 error = (*pcd->pcd_write_pmc)(cpu, adjri, 3607 prw.pm_value); 3608 error: 3609 critical_exit(); 3610 pmc_restore_cpu_binding(&pb); 3611 if (error) 3612 break; 3613 } 3614 3615 pprw = (struct pmc_op_pmcrw *) arg; 3616 3617 #ifdef DEBUG 3618 if (prw.pm_flags & PMC_F_NEWVALUE) 3619 PMCDBG(PMC,OPS,2, "rw id=%d new %jx -> old %jx", 3620 ri, prw.pm_value, oldvalue); 3621 else if (prw.pm_flags & PMC_F_OLDVALUE) 3622 PMCDBG(PMC,OPS,2, "rw id=%d -> old %jx", ri, oldvalue); 3623 #endif 3624 3625 /* return old value if requested */ 3626 if (prw.pm_flags & PMC_F_OLDVALUE) 3627 if ((error = copyout(&oldvalue, &pprw->pm_value, 3628 sizeof(prw.pm_value)))) 3629 break; 3630 3631 } 3632 break; 3633 3634 3635 /* 3636 * Set the sampling rate for a sampling mode PMC and the 3637 * initial count for a counting mode PMC. 3638 */ 3639 3640 case PMC_OP_PMCSETCOUNT: 3641 { 3642 struct pmc *pm; 3643 struct pmc_op_pmcsetcount sc; 3644 3645 PMC_DOWNGRADE_SX(); 3646 3647 if ((error = copyin(arg, &sc, sizeof(sc))) != 0) 3648 break; 3649 3650 if ((error = pmc_find_pmc(sc.pm_pmcid, &pm)) != 0) 3651 break; 3652 3653 if (pm->pm_state == PMC_STATE_RUNNING) { 3654 error = EBUSY; 3655 break; 3656 } 3657 3658 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 3659 pm->pm_sc.pm_reloadcount = sc.pm_count; 3660 else 3661 pm->pm_sc.pm_initial = sc.pm_count; 3662 } 3663 break; 3664 3665 3666 /* 3667 * Start a PMC. 3668 */ 3669 3670 case PMC_OP_PMCSTART: 3671 { 3672 pmc_id_t pmcid; 3673 struct pmc *pm; 3674 struct pmc_op_simple sp; 3675 3676 sx_assert(&pmc_sx, SX_XLOCKED); 3677 3678 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3679 break; 3680 3681 pmcid = sp.pm_pmcid; 3682 3683 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3684 break; 3685 3686 KASSERT(pmcid == pm->pm_id, 3687 ("[pmc,%d] pmcid %x != id %x", __LINE__, 3688 pm->pm_id, pmcid)); 3689 3690 if (pm->pm_state == PMC_STATE_RUNNING) /* already running */ 3691 break; 3692 else if (pm->pm_state != PMC_STATE_STOPPED && 3693 pm->pm_state != PMC_STATE_ALLOCATED) { 3694 error = EINVAL; 3695 break; 3696 } 3697 3698 error = pmc_start(pm); 3699 } 3700 break; 3701 3702 3703 /* 3704 * Stop a PMC. 3705 */ 3706 3707 case PMC_OP_PMCSTOP: 3708 { 3709 pmc_id_t pmcid; 3710 struct pmc *pm; 3711 struct pmc_op_simple sp; 3712 3713 PMC_DOWNGRADE_SX(); 3714 3715 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3716 break; 3717 3718 pmcid = sp.pm_pmcid; 3719 3720 /* 3721 * Mark the PMC as inactive and invoke the MD stop 3722 * routines if needed. 3723 */ 3724 3725 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3726 break; 3727 3728 KASSERT(pmcid == pm->pm_id, 3729 ("[pmc,%d] pmc id %x != pmcid %x", __LINE__, 3730 pm->pm_id, pmcid)); 3731 3732 if (pm->pm_state == PMC_STATE_STOPPED) /* already stopped */ 3733 break; 3734 else if (pm->pm_state != PMC_STATE_RUNNING) { 3735 error = EINVAL; 3736 break; 3737 } 3738 3739 error = pmc_stop(pm); 3740 } 3741 break; 3742 3743 3744 /* 3745 * Write a user supplied value to the log file. 3746 */ 3747 3748 case PMC_OP_WRITELOG: 3749 { 3750 struct pmc_op_writelog wl; 3751 struct pmc_owner *po; 3752 3753 PMC_DOWNGRADE_SX(); 3754 3755 if ((error = copyin(arg, &wl, sizeof(wl))) != 0) 3756 break; 3757 3758 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 3759 error = EINVAL; 3760 break; 3761 } 3762 3763 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) { 3764 error = EINVAL; 3765 break; 3766 } 3767 3768 error = pmclog_process_userlog(po, &wl); 3769 } 3770 break; 3771 3772 3773 default: 3774 error = EINVAL; 3775 break; 3776 } 3777 3778 if (is_sx_locked != 0) { 3779 if (is_sx_downgraded) 3780 sx_sunlock(&pmc_sx); 3781 else 3782 sx_xunlock(&pmc_sx); 3783 } 3784 3785 if (error) 3786 atomic_add_int(&pmc_stats.pm_syscall_errors, 1); 3787 3788 PICKUP_GIANT(); 3789 3790 return error; 3791 } 3792 3793 /* 3794 * Helper functions 3795 */ 3796 3797 3798 /* 3799 * Mark the thread as needing callchain capture and post an AST. The 3800 * actual callchain capture will be done in a context where it is safe 3801 * to take page faults. 3802 */ 3803 3804 static void 3805 pmc_post_callchain_callback(void) 3806 { 3807 struct thread *td; 3808 3809 td = curthread; 3810 3811 KASSERT((td->td_pflags & TDP_CALLCHAIN) == 0, 3812 ("[pmc,%d] thread %p already marked for callchain capture", 3813 __LINE__, (void *) td)); 3814 3815 /* 3816 * Mark this thread as needing callchain capture. 3817 * `td->td_pflags' will be safe to touch because this thread 3818 * was in user space when it was interrupted. 3819 */ 3820 td->td_pflags |= TDP_CALLCHAIN; 3821 3822 /* 3823 * Don't let this thread migrate between CPUs until callchain 3824 * capture completes. 3825 */ 3826 sched_pin(); 3827 3828 return; 3829 } 3830 3831 /* 3832 * Interrupt processing. 3833 * 3834 * Find a free slot in the per-cpu array of samples and capture the 3835 * current callchain there. If a sample was successfully added, a bit 3836 * is set in mask 'pmc_cpumask' denoting that the DO_SAMPLES hook 3837 * needs to be invoked from the clock handler. 3838 * 3839 * This function is meant to be called from an NMI handler. It cannot 3840 * use any of the locking primitives supplied by the OS. 3841 */ 3842 3843 int 3844 pmc_process_interrupt(int cpu, struct pmc *pm, struct trapframe *tf, 3845 int inuserspace) 3846 { 3847 int error, callchaindepth; 3848 struct thread *td; 3849 struct pmc_sample *ps; 3850 struct pmc_samplebuffer *psb; 3851 3852 error = 0; 3853 3854 /* 3855 * Allocate space for a sample buffer. 3856 */ 3857 psb = pmc_pcpu[cpu]->pc_sb; 3858 3859 ps = psb->ps_write; 3860 if (ps->ps_nsamples) { /* in use, reader hasn't caught up */ 3861 pm->pm_stalled = 1; 3862 atomic_add_int(&pmc_stats.pm_intr_bufferfull, 1); 3863 PMCDBG(SAM,INT,1,"(spc) cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", 3864 cpu, pm, (void *) tf, inuserspace, 3865 (int) (psb->ps_write - psb->ps_samples), 3866 (int) (psb->ps_read - psb->ps_samples)); 3867 error = ENOMEM; 3868 goto done; 3869 } 3870 3871 3872 /* Fill in entry. */ 3873 PMCDBG(SAM,INT,1,"cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", cpu, pm, 3874 (void *) tf, inuserspace, 3875 (int) (psb->ps_write - psb->ps_samples), 3876 (int) (psb->ps_read - psb->ps_samples)); 3877 3878 KASSERT(pm->pm_runcount >= 0, 3879 ("[pmc,%d] pm=%p runcount %d", __LINE__, (void *) pm, 3880 pm->pm_runcount)); 3881 3882 atomic_add_rel_32(&pm->pm_runcount, 1); /* hold onto PMC */ 3883 ps->ps_pmc = pm; 3884 if ((td = curthread) && td->td_proc) 3885 ps->ps_pid = td->td_proc->p_pid; 3886 else 3887 ps->ps_pid = -1; 3888 ps->ps_cpu = cpu; 3889 ps->ps_td = td; 3890 ps->ps_flags = inuserspace ? PMC_CC_F_USERSPACE : 0; 3891 3892 callchaindepth = (pm->pm_flags & PMC_F_CALLCHAIN) ? 3893 pmc_callchaindepth : 1; 3894 3895 if (callchaindepth == 1) 3896 ps->ps_pc[0] = PMC_TRAPFRAME_TO_PC(tf); 3897 else { 3898 /* 3899 * Kernel stack traversals can be done immediately, 3900 * while we defer to an AST for user space traversals. 3901 */ 3902 if (!inuserspace) 3903 callchaindepth = 3904 pmc_save_kernel_callchain(ps->ps_pc, 3905 callchaindepth, tf); 3906 else { 3907 pmc_post_callchain_callback(); 3908 callchaindepth = PMC_SAMPLE_INUSE; 3909 } 3910 } 3911 3912 ps->ps_nsamples = callchaindepth; /* mark entry as in use */ 3913 3914 /* increment write pointer, modulo ring buffer size */ 3915 ps++; 3916 if (ps == psb->ps_fence) 3917 psb->ps_write = psb->ps_samples; 3918 else 3919 psb->ps_write = ps; 3920 3921 done: 3922 /* mark CPU as needing processing */ 3923 atomic_set_rel_int(&pmc_cpumask, (1 << cpu)); 3924 3925 return (error); 3926 } 3927 3928 /* 3929 * Capture a user call chain. This function will be called from ast() 3930 * before control returns to userland and before the process gets 3931 * rescheduled. 3932 */ 3933 3934 static void 3935 pmc_capture_user_callchain(int cpu, struct trapframe *tf) 3936 { 3937 int i; 3938 struct pmc *pm; 3939 struct thread *td; 3940 struct pmc_sample *ps; 3941 struct pmc_samplebuffer *psb; 3942 #ifdef INVARIANTS 3943 int ncallchains; 3944 #endif 3945 3946 sched_unpin(); /* Can migrate safely now. */ 3947 3948 psb = pmc_pcpu[cpu]->pc_sb; 3949 td = curthread; 3950 3951 KASSERT(td->td_pflags & TDP_CALLCHAIN, 3952 ("[pmc,%d] Retrieving callchain for thread that doesn't want it", 3953 __LINE__)); 3954 3955 #ifdef INVARIANTS 3956 ncallchains = 0; 3957 #endif 3958 3959 /* 3960 * Iterate through all deferred callchain requests. 3961 */ 3962 3963 ps = psb->ps_samples; 3964 for (i = 0; i < pmc_nsamples; i++, ps++) { 3965 3966 if (ps->ps_nsamples != PMC_SAMPLE_INUSE) 3967 continue; 3968 if (ps->ps_td != td) 3969 continue; 3970 3971 KASSERT(ps->ps_cpu == cpu, 3972 ("[pmc,%d] cpu mismatch ps_cpu=%d pcpu=%d", __LINE__, 3973 ps->ps_cpu, PCPU_GET(cpuid))); 3974 3975 pm = ps->ps_pmc; 3976 3977 KASSERT(pm->pm_flags & PMC_F_CALLCHAIN, 3978 ("[pmc,%d] Retrieving callchain for PMC that doesn't " 3979 "want it", __LINE__)); 3980 3981 KASSERT(pm->pm_runcount > 0, 3982 ("[pmc,%d] runcount %d", __LINE__, pm->pm_runcount)); 3983 3984 /* 3985 * Retrieve the callchain and mark the sample buffer 3986 * as 'processable' by the timer tick sweep code. 3987 */ 3988 ps->ps_nsamples = pmc_save_user_callchain(ps->ps_pc, 3989 pmc_callchaindepth, tf); 3990 3991 #ifdef INVARIANTS 3992 ncallchains++; 3993 #endif 3994 3995 } 3996 3997 KASSERT(ncallchains > 0, 3998 ("[pmc,%d] cpu %d didn't find a sample to collect", __LINE__, 3999 cpu)); 4000 4001 return; 4002 } 4003 4004 4005 /* 4006 * Process saved PC samples. 4007 */ 4008 4009 static void 4010 pmc_process_samples(int cpu) 4011 { 4012 struct pmc *pm; 4013 int adjri, n; 4014 struct thread *td; 4015 struct pmc_owner *po; 4016 struct pmc_sample *ps; 4017 struct pmc_classdep *pcd; 4018 struct pmc_samplebuffer *psb; 4019 4020 KASSERT(PCPU_GET(cpuid) == cpu, 4021 ("[pmc,%d] not on the correct CPU pcpu=%d cpu=%d", __LINE__, 4022 PCPU_GET(cpuid), cpu)); 4023 4024 psb = pmc_pcpu[cpu]->pc_sb; 4025 4026 for (n = 0; n < pmc_nsamples; n++) { /* bound on #iterations */ 4027 4028 ps = psb->ps_read; 4029 if (ps->ps_nsamples == PMC_SAMPLE_FREE) 4030 break; 4031 if (ps->ps_nsamples == PMC_SAMPLE_INUSE) { 4032 /* Need a rescan at a later time. */ 4033 atomic_set_rel_int(&pmc_cpumask, (1 << cpu)); 4034 break; 4035 } 4036 4037 pm = ps->ps_pmc; 4038 4039 KASSERT(pm->pm_runcount > 0, 4040 ("[pmc,%d] pm=%p runcount %d", __LINE__, (void *) pm, 4041 pm->pm_runcount)); 4042 4043 po = pm->pm_owner; 4044 4045 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 4046 ("[pmc,%d] pmc=%p non-sampling mode=%d", __LINE__, 4047 pm, PMC_TO_MODE(pm))); 4048 4049 /* Ignore PMCs that have been switched off */ 4050 if (pm->pm_state != PMC_STATE_RUNNING) 4051 goto entrydone; 4052 4053 PMCDBG(SAM,OPS,1,"cpu=%d pm=%p n=%d fl=%x wr=%d rd=%d", cpu, 4054 pm, ps->ps_nsamples, ps->ps_flags, 4055 (int) (psb->ps_write - psb->ps_samples), 4056 (int) (psb->ps_read - psb->ps_samples)); 4057 4058 /* 4059 * If this is a process-mode PMC that is attached to 4060 * its owner, and if the PC is in user mode, update 4061 * profiling statistics like timer-based profiling 4062 * would have done. 4063 */ 4064 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) { 4065 if (ps->ps_flags & PMC_CC_F_USERSPACE) { 4066 td = FIRST_THREAD_IN_PROC(po->po_owner); 4067 addupc_intr(td, ps->ps_pc[0], 1); 4068 } 4069 goto entrydone; 4070 } 4071 4072 /* 4073 * Otherwise, this is either a sampling mode PMC that 4074 * is attached to a different process than its owner, 4075 * or a system-wide sampling PMC. Dispatch a log 4076 * entry to the PMC's owner process. 4077 */ 4078 4079 pmclog_process_callchain(pm, ps); 4080 4081 entrydone: 4082 ps->ps_nsamples = 0; /* mark entry as free */ 4083 atomic_subtract_rel_32(&pm->pm_runcount, 1); 4084 4085 /* increment read pointer, modulo sample size */ 4086 if (++ps == psb->ps_fence) 4087 psb->ps_read = psb->ps_samples; 4088 else 4089 psb->ps_read = ps; 4090 } 4091 4092 atomic_add_int(&pmc_stats.pm_log_sweeps, 1); 4093 4094 /* Do not re-enable stalled PMCs if we failed to process any samples */ 4095 if (n == 0) 4096 return; 4097 4098 /* 4099 * Restart any stalled sampling PMCs on this CPU. 4100 * 4101 * If the NMI handler sets the pm_stalled field of a PMC after 4102 * the check below, we'll end up processing the stalled PMC at 4103 * the next hardclock tick. 4104 */ 4105 for (n = 0; n < md->pmd_npmc; n++) { 4106 pcd = pmc_ri_to_classdep(md, n, &adjri); 4107 KASSERT(pcd != NULL, 4108 ("[pmc,%d] null pcd ri=%d", __LINE__, n)); 4109 (void) (*pcd->pcd_get_config)(cpu,adjri,&pm); 4110 4111 if (pm == NULL || /* !cfg'ed */ 4112 pm->pm_state != PMC_STATE_RUNNING || /* !active */ 4113 !PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) || /* !sampling */ 4114 pm->pm_stalled == 0) /* !stalled */ 4115 continue; 4116 4117 pm->pm_stalled = 0; 4118 (*pcd->pcd_start_pmc)(cpu, adjri); 4119 } 4120 } 4121 4122 /* 4123 * Event handlers. 4124 */ 4125 4126 /* 4127 * Handle a process exit. 4128 * 4129 * Remove this process from all hash tables. If this process 4130 * owned any PMCs, turn off those PMCs and deallocate them, 4131 * removing any associations with target processes. 4132 * 4133 * This function will be called by the last 'thread' of a 4134 * process. 4135 * 4136 * XXX This eventhandler gets called early in the exit process. 4137 * Consider using a 'hook' invocation from thread_exit() or equivalent 4138 * spot. Another negative is that kse_exit doesn't seem to call 4139 * exit1() [??]. 4140 * 4141 */ 4142 4143 static void 4144 pmc_process_exit(void *arg __unused, struct proc *p) 4145 { 4146 struct pmc *pm; 4147 int adjri, cpu; 4148 unsigned int ri; 4149 int is_using_hwpmcs; 4150 struct pmc_owner *po; 4151 struct pmc_process *pp; 4152 struct pmc_classdep *pcd; 4153 pmc_value_t newvalue, tmp; 4154 4155 PROC_LOCK(p); 4156 is_using_hwpmcs = p->p_flag & P_HWPMC; 4157 PROC_UNLOCK(p); 4158 4159 /* 4160 * Log a sysexit event to all SS PMC owners. 4161 */ 4162 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4163 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4164 pmclog_process_sysexit(po, p->p_pid); 4165 4166 if (!is_using_hwpmcs) 4167 return; 4168 4169 PMC_GET_SX_XLOCK(); 4170 PMCDBG(PRC,EXT,1,"process-exit proc=%p (%d, %s)", p, p->p_pid, 4171 p->p_comm); 4172 4173 /* 4174 * Since this code is invoked by the last thread in an exiting 4175 * process, we would have context switched IN at some prior 4176 * point. However, with PREEMPTION, kernel mode context 4177 * switches may happen any time, so we want to disable a 4178 * context switch OUT till we get any PMCs targetting this 4179 * process off the hardware. 4180 * 4181 * We also need to atomically remove this process' 4182 * entry from our target process hash table, using 4183 * PMC_FLAG_REMOVE. 4184 */ 4185 PMCDBG(PRC,EXT,1, "process-exit proc=%p (%d, %s)", p, p->p_pid, 4186 p->p_comm); 4187 4188 critical_enter(); /* no preemption */ 4189 4190 cpu = curthread->td_oncpu; 4191 4192 if ((pp = pmc_find_process_descriptor(p, 4193 PMC_FLAG_REMOVE)) != NULL) { 4194 4195 PMCDBG(PRC,EXT,2, 4196 "process-exit proc=%p pmc-process=%p", p, pp); 4197 4198 /* 4199 * The exiting process could the target of 4200 * some PMCs which will be running on 4201 * currently executing CPU. 4202 * 4203 * We need to turn these PMCs off like we 4204 * would do at context switch OUT time. 4205 */ 4206 for (ri = 0; ri < md->pmd_npmc; ri++) { 4207 4208 /* 4209 * Pick up the pmc pointer from hardware 4210 * state similar to the CSW_OUT code. 4211 */ 4212 pm = NULL; 4213 4214 pcd = pmc_ri_to_classdep(md, ri, &adjri); 4215 4216 (void) (*pcd->pcd_get_config)(cpu, adjri, &pm); 4217 4218 PMCDBG(PRC,EXT,2, "ri=%d pm=%p", ri, pm); 4219 4220 if (pm == NULL || 4221 !PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 4222 continue; 4223 4224 PMCDBG(PRC,EXT,2, "ppmcs[%d]=%p pm=%p " 4225 "state=%d", ri, pp->pp_pmcs[ri].pp_pmc, 4226 pm, pm->pm_state); 4227 4228 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 4229 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 4230 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 4231 4232 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 4233 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", 4234 __LINE__, pm, ri, pp->pp_pmcs[ri].pp_pmc)); 4235 4236 (void) pcd->pcd_stop_pmc(cpu, adjri); 4237 4238 KASSERT(pm->pm_runcount > 0, 4239 ("[pmc,%d] bad runcount ri %d rc %d", 4240 __LINE__, ri, pm->pm_runcount)); 4241 4242 /* Stop hardware only if it is actually running */ 4243 if (pm->pm_state == PMC_STATE_RUNNING && 4244 pm->pm_stalled == 0) { 4245 pcd->pcd_read_pmc(cpu, adjri, &newvalue); 4246 tmp = newvalue - 4247 PMC_PCPU_SAVED(cpu,ri); 4248 4249 mtx_pool_lock_spin(pmc_mtxpool, pm); 4250 pm->pm_gv.pm_savedvalue += tmp; 4251 pp->pp_pmcs[ri].pp_pmcval += tmp; 4252 mtx_pool_unlock_spin(pmc_mtxpool, pm); 4253 } 4254 4255 atomic_subtract_rel_32(&pm->pm_runcount,1); 4256 4257 KASSERT((int) pm->pm_runcount >= 0, 4258 ("[pmc,%d] runcount is %d", __LINE__, ri)); 4259 4260 (void) pcd->pcd_config_pmc(cpu, adjri, NULL); 4261 } 4262 4263 /* 4264 * Inform the MD layer of this pseudo "context switch 4265 * out" 4266 */ 4267 (void) md->pmd_switch_out(pmc_pcpu[cpu], pp); 4268 4269 critical_exit(); /* ok to be pre-empted now */ 4270 4271 /* 4272 * Unlink this process from the PMCs that are 4273 * targetting it. This will send a signal to 4274 * all PMC owner's whose PMCs are orphaned. 4275 * 4276 * Log PMC value at exit time if requested. 4277 */ 4278 for (ri = 0; ri < md->pmd_npmc; ri++) 4279 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 4280 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 4281 PMC_IS_COUNTING_MODE(PMC_TO_MODE(pm))) 4282 pmclog_process_procexit(pm, pp); 4283 pmc_unlink_target_process(pm, pp); 4284 } 4285 free(pp, M_PMC); 4286 4287 } else 4288 critical_exit(); /* pp == NULL */ 4289 4290 4291 /* 4292 * If the process owned PMCs, free them up and free up 4293 * memory. 4294 */ 4295 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 4296 pmc_remove_owner(po); 4297 pmc_destroy_owner_descriptor(po); 4298 } 4299 4300 sx_xunlock(&pmc_sx); 4301 } 4302 4303 /* 4304 * Handle a process fork. 4305 * 4306 * If the parent process 'p1' is under HWPMC monitoring, then copy 4307 * over any attached PMCs that have 'do_descendants' semantics. 4308 */ 4309 4310 static void 4311 pmc_process_fork(void *arg __unused, struct proc *p1, struct proc *newproc, 4312 int flags) 4313 { 4314 int is_using_hwpmcs; 4315 unsigned int ri; 4316 uint32_t do_descendants; 4317 struct pmc *pm; 4318 struct pmc_owner *po; 4319 struct pmc_process *ppnew, *ppold; 4320 4321 (void) flags; /* unused parameter */ 4322 4323 PROC_LOCK(p1); 4324 is_using_hwpmcs = p1->p_flag & P_HWPMC; 4325 PROC_UNLOCK(p1); 4326 4327 /* 4328 * If there are system-wide sampling PMCs active, we need to 4329 * log all fork events to their owner's logs. 4330 */ 4331 4332 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4333 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4334 pmclog_process_procfork(po, p1->p_pid, newproc->p_pid); 4335 4336 if (!is_using_hwpmcs) 4337 return; 4338 4339 PMC_GET_SX_XLOCK(); 4340 PMCDBG(PMC,FRK,1, "process-fork proc=%p (%d, %s) -> %p", p1, 4341 p1->p_pid, p1->p_comm, newproc); 4342 4343 /* 4344 * If the parent process (curthread->td_proc) is a 4345 * target of any PMCs, look for PMCs that are to be 4346 * inherited, and link these into the new process 4347 * descriptor. 4348 */ 4349 if ((ppold = pmc_find_process_descriptor(curthread->td_proc, 4350 PMC_FLAG_NONE)) == NULL) 4351 goto done; /* nothing to do */ 4352 4353 do_descendants = 0; 4354 for (ri = 0; ri < md->pmd_npmc; ri++) 4355 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL) 4356 do_descendants |= pm->pm_flags & PMC_F_DESCENDANTS; 4357 if (do_descendants == 0) /* nothing to do */ 4358 goto done; 4359 4360 /* allocate a descriptor for the new process */ 4361 if ((ppnew = pmc_find_process_descriptor(newproc, 4362 PMC_FLAG_ALLOCATE)) == NULL) 4363 goto done; 4364 4365 /* 4366 * Run through all PMCs that were targeting the old process 4367 * and which specified F_DESCENDANTS and attach them to the 4368 * new process. 4369 * 4370 * Log the fork event to all owners of PMCs attached to this 4371 * process, if not already logged. 4372 */ 4373 for (ri = 0; ri < md->pmd_npmc; ri++) 4374 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL && 4375 (pm->pm_flags & PMC_F_DESCENDANTS)) { 4376 pmc_link_target_process(pm, ppnew); 4377 po = pm->pm_owner; 4378 if (po->po_sscount == 0 && 4379 po->po_flags & PMC_PO_OWNS_LOGFILE) 4380 pmclog_process_procfork(po, p1->p_pid, 4381 newproc->p_pid); 4382 } 4383 4384 /* 4385 * Now mark the new process as being tracked by this driver. 4386 */ 4387 PROC_LOCK(newproc); 4388 newproc->p_flag |= P_HWPMC; 4389 PROC_UNLOCK(newproc); 4390 4391 done: 4392 sx_xunlock(&pmc_sx); 4393 } 4394 4395 4396 /* 4397 * initialization 4398 */ 4399 4400 static const char *pmc_name_of_pmcclass[] = { 4401 #undef __PMC_CLASS 4402 #define __PMC_CLASS(N) #N , 4403 __PMC_CLASSES() 4404 }; 4405 4406 static int 4407 pmc_initialize(void) 4408 { 4409 int c, cpu, error, n, ri; 4410 unsigned int maxcpu; 4411 struct pmc_binding pb; 4412 struct pmc_sample *ps; 4413 struct pmc_classdep *pcd; 4414 struct pmc_samplebuffer *sb; 4415 4416 md = NULL; 4417 error = 0; 4418 4419 #ifdef DEBUG 4420 /* parse debug flags first */ 4421 if (TUNABLE_STR_FETCH(PMC_SYSCTL_NAME_PREFIX "debugflags", 4422 pmc_debugstr, sizeof(pmc_debugstr))) 4423 pmc_debugflags_parse(pmc_debugstr, 4424 pmc_debugstr+strlen(pmc_debugstr)); 4425 #endif 4426 4427 PMCDBG(MOD,INI,0, "PMC Initialize (version %x)", PMC_VERSION); 4428 4429 /* check kernel version */ 4430 if (pmc_kernel_version != PMC_VERSION) { 4431 if (pmc_kernel_version == 0) 4432 printf("hwpmc: this kernel has not been compiled with " 4433 "'options HWPMC_HOOKS'.\n"); 4434 else 4435 printf("hwpmc: kernel version (0x%x) does not match " 4436 "module version (0x%x).\n", pmc_kernel_version, 4437 PMC_VERSION); 4438 return EPROGMISMATCH; 4439 } 4440 4441 /* 4442 * check sysctl parameters 4443 */ 4444 4445 if (pmc_hashsize <= 0) { 4446 (void) printf("hwpmc: tunable \"hashsize\"=%d must be " 4447 "greater than zero.\n", pmc_hashsize); 4448 pmc_hashsize = PMC_HASH_SIZE; 4449 } 4450 4451 if (pmc_nsamples <= 0 || pmc_nsamples > 65535) { 4452 (void) printf("hwpmc: tunable \"nsamples\"=%d out of " 4453 "range.\n", pmc_nsamples); 4454 pmc_nsamples = PMC_NSAMPLES; 4455 } 4456 4457 if (pmc_callchaindepth <= 0 || 4458 pmc_callchaindepth > PMC_CALLCHAIN_DEPTH_MAX) { 4459 (void) printf("hwpmc: tunable \"callchaindepth\"=%d out of " 4460 "range.\n", pmc_callchaindepth); 4461 pmc_callchaindepth = PMC_CALLCHAIN_DEPTH; 4462 } 4463 4464 md = pmc_md_initialize(); 4465 4466 if (md == NULL) 4467 return (ENOSYS); 4468 4469 KASSERT(md->pmd_nclass >= 1 && md->pmd_npmc >= 1, 4470 ("[pmc,%d] no classes or pmcs", __LINE__)); 4471 4472 /* Compute the map from row-indices to classdep pointers. */ 4473 pmc_rowindex_to_classdep = malloc(sizeof(struct pmc_classdep *) * 4474 md->pmd_npmc, M_PMC, M_WAITOK|M_ZERO); 4475 4476 for (n = 0; n < md->pmd_npmc; n++) 4477 pmc_rowindex_to_classdep[n] = NULL; 4478 for (ri = c = 0; c < md->pmd_nclass; c++) { 4479 pcd = &md->pmd_classdep[c]; 4480 for (n = 0; n < pcd->pcd_num; n++, ri++) 4481 pmc_rowindex_to_classdep[ri] = pcd; 4482 } 4483 4484 KASSERT(ri == md->pmd_npmc, 4485 ("[pmc,%d] npmc miscomputed: ri=%d, md->npmc=%d", __LINE__, 4486 ri, md->pmd_npmc)); 4487 4488 maxcpu = pmc_cpu_max(); 4489 4490 /* allocate space for the per-cpu array */ 4491 pmc_pcpu = malloc(maxcpu * sizeof(struct pmc_cpu *), M_PMC, 4492 M_WAITOK|M_ZERO); 4493 4494 /* per-cpu 'saved values' for managing process-mode PMCs */ 4495 pmc_pcpu_saved = malloc(sizeof(pmc_value_t) * maxcpu * md->pmd_npmc, 4496 M_PMC, M_WAITOK); 4497 4498 /* Perform CPU-dependent initialization. */ 4499 pmc_save_cpu_binding(&pb); 4500 error = 0; 4501 for (cpu = 0; error == 0 && cpu < maxcpu; cpu++) { 4502 if (!pmc_cpu_is_active(cpu)) 4503 continue; 4504 pmc_select_cpu(cpu); 4505 pmc_pcpu[cpu] = malloc(sizeof(struct pmc_cpu) + 4506 md->pmd_npmc * sizeof(struct pmc_hw *), M_PMC, 4507 M_WAITOK|M_ZERO); 4508 if (md->pmd_pcpu_init) 4509 error = md->pmd_pcpu_init(md, cpu); 4510 for (n = 0; error == 0 && n < md->pmd_nclass; n++) 4511 error = md->pmd_classdep[n].pcd_pcpu_init(md, cpu); 4512 } 4513 pmc_restore_cpu_binding(&pb); 4514 4515 if (error) 4516 return (error); 4517 4518 /* allocate space for the sample array */ 4519 for (cpu = 0; cpu < maxcpu; cpu++) { 4520 if (!pmc_cpu_is_active(cpu)) 4521 continue; 4522 4523 sb = malloc(sizeof(struct pmc_samplebuffer) + 4524 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 4525 M_WAITOK|M_ZERO); 4526 sb->ps_read = sb->ps_write = sb->ps_samples; 4527 sb->ps_fence = sb->ps_samples + pmc_nsamples; 4528 4529 KASSERT(pmc_pcpu[cpu] != NULL, 4530 ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu)); 4531 4532 sb->ps_callchains = malloc(pmc_callchaindepth * pmc_nsamples * 4533 sizeof(uintptr_t), M_PMC, M_WAITOK|M_ZERO); 4534 4535 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 4536 ps->ps_pc = sb->ps_callchains + 4537 (n * pmc_callchaindepth); 4538 4539 pmc_pcpu[cpu]->pc_sb = sb; 4540 } 4541 4542 /* allocate space for the row disposition array */ 4543 pmc_pmcdisp = malloc(sizeof(enum pmc_mode) * md->pmd_npmc, 4544 M_PMC, M_WAITOK|M_ZERO); 4545 4546 KASSERT(pmc_pmcdisp != NULL, 4547 ("[pmc,%d] pmcdisp allocation returned NULL", __LINE__)); 4548 4549 /* mark all PMCs as available */ 4550 for (n = 0; n < (int) md->pmd_npmc; n++) 4551 PMC_MARK_ROW_FREE(n); 4552 4553 /* allocate thread hash tables */ 4554 pmc_ownerhash = hashinit(pmc_hashsize, M_PMC, 4555 &pmc_ownerhashmask); 4556 4557 pmc_processhash = hashinit(pmc_hashsize, M_PMC, 4558 &pmc_processhashmask); 4559 mtx_init(&pmc_processhash_mtx, "pmc-process-hash", "pmc-leaf", 4560 MTX_SPIN); 4561 4562 LIST_INIT(&pmc_ss_owners); 4563 pmc_ss_count = 0; 4564 4565 /* allocate a pool of spin mutexes */ 4566 pmc_mtxpool = mtx_pool_create("pmc-leaf", pmc_mtxpool_size, 4567 MTX_SPIN); 4568 4569 PMCDBG(MOD,INI,1, "pmc_ownerhash=%p, mask=0x%lx " 4570 "targethash=%p mask=0x%lx", pmc_ownerhash, pmc_ownerhashmask, 4571 pmc_processhash, pmc_processhashmask); 4572 4573 /* register process {exit,fork,exec} handlers */ 4574 pmc_exit_tag = EVENTHANDLER_REGISTER(process_exit, 4575 pmc_process_exit, NULL, EVENTHANDLER_PRI_ANY); 4576 pmc_fork_tag = EVENTHANDLER_REGISTER(process_fork, 4577 pmc_process_fork, NULL, EVENTHANDLER_PRI_ANY); 4578 4579 /* initialize logging */ 4580 pmclog_initialize(); 4581 4582 /* set hook functions */ 4583 pmc_intr = md->pmd_intr; 4584 pmc_hook = pmc_hook_handler; 4585 4586 if (error == 0) { 4587 printf(PMC_MODULE_NAME ":"); 4588 for (n = 0; n < (int) md->pmd_nclass; n++) { 4589 pcd = &md->pmd_classdep[n]; 4590 printf(" %s/%d/%d/0x%b", 4591 pmc_name_of_pmcclass[pcd->pcd_class], 4592 pcd->pcd_num, 4593 pcd->pcd_width, 4594 pcd->pcd_caps, 4595 "\20" 4596 "\1INT\2USR\3SYS\4EDG\5THR" 4597 "\6REA\7WRI\10INV\11QUA\12PRC" 4598 "\13TAG\14CSC"); 4599 } 4600 printf("\n"); 4601 } 4602 4603 return (error); 4604 } 4605 4606 /* prepare to be unloaded */ 4607 static void 4608 pmc_cleanup(void) 4609 { 4610 int c, cpu; 4611 unsigned int maxcpu; 4612 struct pmc_ownerhash *ph; 4613 struct pmc_owner *po, *tmp; 4614 struct pmc_binding pb; 4615 #ifdef DEBUG 4616 struct pmc_processhash *prh; 4617 #endif 4618 4619 PMCDBG(MOD,INI,0, "%s", "cleanup"); 4620 4621 /* switch off sampling */ 4622 atomic_store_rel_int(&pmc_cpumask, 0); 4623 pmc_intr = NULL; 4624 4625 sx_xlock(&pmc_sx); 4626 if (pmc_hook == NULL) { /* being unloaded already */ 4627 sx_xunlock(&pmc_sx); 4628 return; 4629 } 4630 4631 pmc_hook = NULL; /* prevent new threads from entering module */ 4632 4633 /* deregister event handlers */ 4634 EVENTHANDLER_DEREGISTER(process_fork, pmc_fork_tag); 4635 EVENTHANDLER_DEREGISTER(process_exit, pmc_exit_tag); 4636 4637 /* send SIGBUS to all owner threads, free up allocations */ 4638 if (pmc_ownerhash) 4639 for (ph = pmc_ownerhash; 4640 ph <= &pmc_ownerhash[pmc_ownerhashmask]; 4641 ph++) { 4642 LIST_FOREACH_SAFE(po, ph, po_next, tmp) { 4643 pmc_remove_owner(po); 4644 4645 /* send SIGBUS to owner processes */ 4646 PMCDBG(MOD,INI,2, "cleanup signal proc=%p " 4647 "(%d, %s)", po->po_owner, 4648 po->po_owner->p_pid, 4649 po->po_owner->p_comm); 4650 4651 PROC_LOCK(po->po_owner); 4652 psignal(po->po_owner, SIGBUS); 4653 PROC_UNLOCK(po->po_owner); 4654 4655 pmc_destroy_owner_descriptor(po); 4656 } 4657 } 4658 4659 /* reclaim allocated data structures */ 4660 if (pmc_mtxpool) 4661 mtx_pool_destroy(&pmc_mtxpool); 4662 4663 mtx_destroy(&pmc_processhash_mtx); 4664 if (pmc_processhash) { 4665 #ifdef DEBUG 4666 struct pmc_process *pp; 4667 4668 PMCDBG(MOD,INI,3, "%s", "destroy process hash"); 4669 for (prh = pmc_processhash; 4670 prh <= &pmc_processhash[pmc_processhashmask]; 4671 prh++) 4672 LIST_FOREACH(pp, prh, pp_next) 4673 PMCDBG(MOD,INI,3, "pid=%d", pp->pp_proc->p_pid); 4674 #endif 4675 4676 hashdestroy(pmc_processhash, M_PMC, pmc_processhashmask); 4677 pmc_processhash = NULL; 4678 } 4679 4680 if (pmc_ownerhash) { 4681 PMCDBG(MOD,INI,3, "%s", "destroy owner hash"); 4682 hashdestroy(pmc_ownerhash, M_PMC, pmc_ownerhashmask); 4683 pmc_ownerhash = NULL; 4684 } 4685 4686 KASSERT(LIST_EMPTY(&pmc_ss_owners), 4687 ("[pmc,%d] Global SS owner list not empty", __LINE__)); 4688 KASSERT(pmc_ss_count == 0, 4689 ("[pmc,%d] Global SS count not empty", __LINE__)); 4690 4691 /* do processor and pmc-class dependent cleanup */ 4692 maxcpu = pmc_cpu_max(); 4693 4694 PMCDBG(MOD,INI,3, "%s", "md cleanup"); 4695 if (md) { 4696 pmc_save_cpu_binding(&pb); 4697 for (cpu = 0; cpu < maxcpu; cpu++) { 4698 PMCDBG(MOD,INI,1,"pmc-cleanup cpu=%d pcs=%p", 4699 cpu, pmc_pcpu[cpu]); 4700 if (!pmc_cpu_is_active(cpu) || pmc_pcpu[cpu] == NULL) 4701 continue; 4702 pmc_select_cpu(cpu); 4703 for (c = 0; c < md->pmd_nclass; c++) 4704 md->pmd_classdep[c].pcd_pcpu_fini(md, cpu); 4705 if (md->pmd_pcpu_fini) 4706 md->pmd_pcpu_fini(md, cpu); 4707 } 4708 4709 pmc_md_finalize(md); 4710 4711 free(md, M_PMC); 4712 md = NULL; 4713 pmc_restore_cpu_binding(&pb); 4714 } 4715 4716 /* Free per-cpu descriptors. */ 4717 for (cpu = 0; cpu < maxcpu; cpu++) { 4718 if (!pmc_cpu_is_active(cpu)) 4719 continue; 4720 KASSERT(pmc_pcpu[cpu]->pc_sb != NULL, 4721 ("[pmc,%d] Null cpu sample buffer cpu=%d", __LINE__, 4722 cpu)); 4723 free(pmc_pcpu[cpu]->pc_sb->ps_callchains, M_PMC); 4724 free(pmc_pcpu[cpu]->pc_sb, M_PMC); 4725 free(pmc_pcpu[cpu], M_PMC); 4726 } 4727 4728 free(pmc_pcpu, M_PMC); 4729 pmc_pcpu = NULL; 4730 4731 free(pmc_pcpu_saved, M_PMC); 4732 pmc_pcpu_saved = NULL; 4733 4734 if (pmc_pmcdisp) { 4735 free(pmc_pmcdisp, M_PMC); 4736 pmc_pmcdisp = NULL; 4737 } 4738 4739 if (pmc_rowindex_to_classdep) { 4740 free(pmc_rowindex_to_classdep, M_PMC); 4741 pmc_rowindex_to_classdep = NULL; 4742 } 4743 4744 pmclog_shutdown(); 4745 4746 sx_xunlock(&pmc_sx); /* we are done */ 4747 } 4748 4749 /* 4750 * The function called at load/unload. 4751 */ 4752 4753 static int 4754 load (struct module *module __unused, int cmd, void *arg __unused) 4755 { 4756 int error; 4757 4758 error = 0; 4759 4760 switch (cmd) { 4761 case MOD_LOAD : 4762 /* initialize the subsystem */ 4763 error = pmc_initialize(); 4764 if (error != 0) 4765 break; 4766 PMCDBG(MOD,INI,1, "syscall=%d maxcpu=%d", 4767 pmc_syscall_num, pmc_cpu_max()); 4768 break; 4769 4770 4771 case MOD_UNLOAD : 4772 case MOD_SHUTDOWN: 4773 pmc_cleanup(); 4774 PMCDBG(MOD,INI,1, "%s", "unloaded"); 4775 break; 4776 4777 default : 4778 error = EINVAL; /* XXX should panic(9) */ 4779 break; 4780 } 4781 4782 return error; 4783 } 4784 4785 /* memory pool */ 4786 MALLOC_DEFINE(M_PMC, "pmc", "Memory space for the PMC module"); 4787