1 /*- 2 * Copyright (c) 2003-2005 Joseph Koshy 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 */ 27 28 #include <sys/cdefs.h> 29 __FBSDID("$FreeBSD$"); 30 31 #include <sys/param.h> 32 #include <sys/eventhandler.h> 33 #include <sys/jail.h> 34 #include <sys/kernel.h> 35 #include <sys/kthread.h> 36 #include <sys/limits.h> 37 #include <sys/lock.h> 38 #include <sys/malloc.h> 39 #include <sys/module.h> 40 #include <sys/mutex.h> 41 #include <sys/pmc.h> 42 #include <sys/pmckern.h> 43 #include <sys/pmclog.h> 44 #include <sys/proc.h> 45 #include <sys/queue.h> 46 #include <sys/resourcevar.h> 47 #include <sys/sched.h> 48 #include <sys/signalvar.h> 49 #include <sys/smp.h> 50 #include <sys/sx.h> 51 #include <sys/sysctl.h> 52 #include <sys/sysent.h> 53 #include <sys/systm.h> 54 #include <sys/vnode.h> 55 56 #include <machine/atomic.h> 57 #include <machine/md_var.h> 58 59 /* 60 * Types 61 */ 62 63 enum pmc_flags { 64 PMC_FLAG_NONE = 0x00, /* do nothing */ 65 PMC_FLAG_REMOVE = 0x01, /* atomically remove entry from hash */ 66 PMC_FLAG_ALLOCATE = 0x02, /* add entry to hash if not found */ 67 }; 68 69 /* 70 * The offset in sysent where the syscall is allocated. 71 */ 72 73 static int pmc_syscall_num = NO_SYSCALL; 74 struct pmc_cpu **pmc_pcpu; /* per-cpu state */ 75 pmc_value_t *pmc_pcpu_saved; /* saved PMC values: CSW handling */ 76 77 #define PMC_PCPU_SAVED(C,R) pmc_pcpu_saved[(R) + md->pmd_npmc*(C)] 78 79 struct mtx_pool *pmc_mtxpool; 80 static int *pmc_pmcdisp; /* PMC row dispositions */ 81 82 #define PMC_ROW_DISP_IS_FREE(R) (pmc_pmcdisp[(R)] == 0) 83 #define PMC_ROW_DISP_IS_THREAD(R) (pmc_pmcdisp[(R)] > 0) 84 #define PMC_ROW_DISP_IS_STANDALONE(R) (pmc_pmcdisp[(R)] < 0) 85 86 #define PMC_MARK_ROW_FREE(R) do { \ 87 pmc_pmcdisp[(R)] = 0; \ 88 } while (0) 89 90 #define PMC_MARK_ROW_STANDALONE(R) do { \ 91 KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \ 92 __LINE__)); \ 93 atomic_add_int(&pmc_pmcdisp[(R)], -1); \ 94 KASSERT(pmc_pmcdisp[(R)] >= (-mp_ncpus), ("[pmc,%d] row " \ 95 "disposition error", __LINE__)); \ 96 } while (0) 97 98 #define PMC_UNMARK_ROW_STANDALONE(R) do { \ 99 atomic_add_int(&pmc_pmcdisp[(R)], 1); \ 100 KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \ 101 __LINE__)); \ 102 } while (0) 103 104 #define PMC_MARK_ROW_THREAD(R) do { \ 105 KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \ 106 __LINE__)); \ 107 atomic_add_int(&pmc_pmcdisp[(R)], 1); \ 108 } while (0) 109 110 #define PMC_UNMARK_ROW_THREAD(R) do { \ 111 atomic_add_int(&pmc_pmcdisp[(R)], -1); \ 112 KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \ 113 __LINE__)); \ 114 } while (0) 115 116 117 /* various event handlers */ 118 static eventhandler_tag pmc_exit_tag, pmc_fork_tag; 119 120 /* Module statistics */ 121 struct pmc_op_getdriverstats pmc_stats; 122 123 /* Machine/processor dependent operations */ 124 struct pmc_mdep *md; 125 126 /* 127 * Hash tables mapping owner processes and target threads to PMCs. 128 */ 129 130 struct mtx pmc_processhash_mtx; /* spin mutex */ 131 static u_long pmc_processhashmask; 132 static LIST_HEAD(pmc_processhash, pmc_process) *pmc_processhash; 133 134 /* 135 * Hash table of PMC owner descriptors. This table is protected by 136 * the shared PMC "sx" lock. 137 */ 138 139 static u_long pmc_ownerhashmask; 140 static LIST_HEAD(pmc_ownerhash, pmc_owner) *pmc_ownerhash; 141 142 /* 143 * List of PMC owners with system-wide sampling PMCs. 144 */ 145 146 static LIST_HEAD(, pmc_owner) pmc_ss_owners; 147 148 149 /* 150 * Prototypes 151 */ 152 153 #if DEBUG 154 static int pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS); 155 static int pmc_debugflags_parse(char *newstr, char *fence); 156 #endif 157 158 static int load(struct module *module, int cmd, void *arg); 159 static int pmc_attach_process(struct proc *p, struct pmc *pm); 160 static struct pmc *pmc_allocate_pmc_descriptor(void); 161 static struct pmc_owner *pmc_allocate_owner_descriptor(struct proc *p); 162 static int pmc_attach_one_process(struct proc *p, struct pmc *pm); 163 static int pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, 164 int cpu); 165 static int pmc_can_attach(struct pmc *pm, struct proc *p); 166 static void pmc_cleanup(void); 167 static int pmc_detach_process(struct proc *p, struct pmc *pm); 168 static int pmc_detach_one_process(struct proc *p, struct pmc *pm, 169 int flags); 170 static void pmc_destroy_owner_descriptor(struct pmc_owner *po); 171 static struct pmc_owner *pmc_find_owner_descriptor(struct proc *p); 172 static int pmc_find_pmc(pmc_id_t pmcid, struct pmc **pm); 173 static struct pmc *pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, 174 pmc_id_t pmc); 175 static struct pmc_process *pmc_find_process_descriptor(struct proc *p, 176 uint32_t mode); 177 static void pmc_force_context_switch(void); 178 static void pmc_link_target_process(struct pmc *pm, 179 struct pmc_process *pp); 180 static void pmc_maybe_remove_owner(struct pmc_owner *po); 181 static void pmc_process_csw_in(struct thread *td); 182 static void pmc_process_csw_out(struct thread *td); 183 static void pmc_process_exit(void *arg, struct proc *p); 184 static void pmc_process_fork(void *arg, struct proc *p1, 185 struct proc *p2, int n); 186 static void pmc_process_samples(int cpu); 187 static void pmc_release_pmc_descriptor(struct pmc *pmc); 188 static void pmc_remove_owner(struct pmc_owner *po); 189 static void pmc_remove_process_descriptor(struct pmc_process *pp); 190 static void pmc_restore_cpu_binding(struct pmc_binding *pb); 191 static void pmc_save_cpu_binding(struct pmc_binding *pb); 192 static void pmc_select_cpu(int cpu); 193 static int pmc_start(struct pmc *pm); 194 static int pmc_stop(struct pmc *pm); 195 static int pmc_syscall_handler(struct thread *td, void *syscall_args); 196 static void pmc_unlink_target_process(struct pmc *pmc, 197 struct pmc_process *pp); 198 199 /* 200 * Kernel tunables and sysctl(8) interface. 201 */ 202 203 SYSCTL_NODE(_kern, OID_AUTO, hwpmc, CTLFLAG_RW, 0, "HWPMC parameters"); 204 205 #if DEBUG 206 struct pmc_debugflags pmc_debugflags = PMC_DEBUG_DEFAULT_FLAGS; 207 char pmc_debugstr[PMC_DEBUG_STRSIZE]; 208 TUNABLE_STR(PMC_SYSCTL_NAME_PREFIX "debugflags", pmc_debugstr, 209 sizeof(pmc_debugstr)); 210 SYSCTL_PROC(_kern_hwpmc, OID_AUTO, debugflags, 211 CTLTYPE_STRING|CTLFLAG_RW|CTLFLAG_TUN, 212 0, 0, pmc_debugflags_sysctl_handler, "A", "debug flags"); 213 #endif 214 215 /* 216 * kern.hwpmc.hashrows -- determines the number of rows in the 217 * of the hash table used to look up threads 218 */ 219 220 static int pmc_hashsize = PMC_HASH_SIZE; 221 TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "hashsize", &pmc_hashsize); 222 SYSCTL_INT(_kern_hwpmc, OID_AUTO, hashsize, CTLFLAG_TUN|CTLFLAG_RD, 223 &pmc_hashsize, 0, "rows in hash tables"); 224 225 /* 226 * kern.hwpmc.nsamples --- number of PC samples per CPU 227 */ 228 229 static int pmc_nsamples = PMC_NSAMPLES; 230 TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "nsamples", &pmc_nsamples); 231 SYSCTL_INT(_kern_hwpmc, OID_AUTO, nsamples, CTLFLAG_TUN|CTLFLAG_RD, 232 &pmc_nsamples, 0, "number of PC samples per CPU"); 233 234 /* 235 * kern.hwpmc.mtxpoolsize -- number of mutexes in the mutex pool. 236 */ 237 238 static int pmc_mtxpool_size = PMC_MTXPOOL_SIZE; 239 TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "mtxpoolsize", &pmc_mtxpool_size); 240 SYSCTL_INT(_kern_hwpmc, OID_AUTO, mtxpoolsize, CTLFLAG_TUN|CTLFLAG_RD, 241 &pmc_mtxpool_size, 0, "size of spin mutex pool"); 242 243 244 /* 245 * security.bsd.unprivileged_syspmcs -- allow non-root processes to 246 * allocate system-wide PMCs. 247 * 248 * Allowing unprivileged processes to allocate system PMCs is convenient 249 * if system-wide measurements need to be taken concurrently with other 250 * per-process measurements. This feature is turned off by default. 251 */ 252 253 SYSCTL_DECL(_security_bsd); 254 255 static int pmc_unprivileged_syspmcs = 0; 256 TUNABLE_INT("security.bsd.unprivileged_syspmcs", &pmc_unprivileged_syspmcs); 257 SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_syspmcs, CTLFLAG_RW, 258 &pmc_unprivileged_syspmcs, 0, 259 "allow unprivileged process to allocate system PMCs"); 260 261 /* 262 * Hash function. Discard the lower 2 bits of the pointer since 263 * these are always zero for our uses. The hash multiplier is 264 * round((2^LONG_BIT) * ((sqrt(5)-1)/2)). 265 */ 266 267 #if LONG_BIT == 64 268 #define _PMC_HM 11400714819323198486u 269 #elif LONG_BIT == 32 270 #define _PMC_HM 2654435769u 271 #else 272 #error Must know the size of 'long' to compile 273 #endif 274 275 #define PMC_HASH_PTR(P,M) ((((unsigned long) (P) >> 2) * _PMC_HM) & (M)) 276 277 /* 278 * Syscall structures 279 */ 280 281 /* The `sysent' for the new syscall */ 282 static struct sysent pmc_sysent = { 283 2, /* sy_narg */ 284 pmc_syscall_handler /* sy_call */ 285 }; 286 287 static struct syscall_module_data pmc_syscall_mod = { 288 load, 289 NULL, 290 &pmc_syscall_num, 291 &pmc_sysent, 292 { 0, NULL } 293 }; 294 295 static moduledata_t pmc_mod = { 296 PMC_MODULE_NAME, 297 syscall_module_handler, 298 &pmc_syscall_mod 299 }; 300 301 DECLARE_MODULE(pmc, pmc_mod, SI_SUB_SMP, SI_ORDER_ANY); 302 MODULE_VERSION(pmc, PMC_VERSION); 303 304 #if DEBUG 305 enum pmc_dbgparse_state { 306 PMCDS_WS, /* in whitespace */ 307 PMCDS_MAJOR, /* seen a major keyword */ 308 PMCDS_MINOR 309 }; 310 311 static int 312 pmc_debugflags_parse(char *newstr, char *fence) 313 { 314 char c, *p, *q; 315 struct pmc_debugflags *tmpflags; 316 int error, found, *newbits, tmp; 317 size_t kwlen; 318 319 MALLOC(tmpflags, struct pmc_debugflags *, sizeof(*tmpflags), 320 M_PMC, M_WAITOK|M_ZERO); 321 322 p = newstr; 323 error = 0; 324 325 for (; p < fence && (c = *p); p++) { 326 327 /* skip white space */ 328 if (c == ' ' || c == '\t') 329 continue; 330 331 /* look for a keyword followed by "=" */ 332 for (q = p; p < fence && (c = *p) && c != '='; p++) 333 ; 334 if (c != '=') { 335 error = EINVAL; 336 goto done; 337 } 338 339 kwlen = p - q; 340 newbits = NULL; 341 342 /* lookup flag group name */ 343 #define DBG_SET_FLAG_MAJ(S,F) \ 344 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \ 345 newbits = &tmpflags->pdb_ ## F; 346 347 DBG_SET_FLAG_MAJ("cpu", CPU); 348 DBG_SET_FLAG_MAJ("csw", CSW); 349 DBG_SET_FLAG_MAJ("logging", LOG); 350 DBG_SET_FLAG_MAJ("module", MOD); 351 DBG_SET_FLAG_MAJ("md", MDP); 352 DBG_SET_FLAG_MAJ("owner", OWN); 353 DBG_SET_FLAG_MAJ("pmc", PMC); 354 DBG_SET_FLAG_MAJ("process", PRC); 355 DBG_SET_FLAG_MAJ("sampling", SAM); 356 357 if (newbits == NULL) { 358 error = EINVAL; 359 goto done; 360 } 361 362 p++; /* skip the '=' */ 363 364 /* Now parse the individual flags */ 365 tmp = 0; 366 newflag: 367 for (q = p; p < fence && (c = *p); p++) 368 if (c == ' ' || c == '\t' || c == ',') 369 break; 370 371 /* p == fence or c == ws or c == "," or c == 0 */ 372 373 if ((kwlen = p - q) == 0) { 374 *newbits = tmp; 375 continue; 376 } 377 378 found = 0; 379 #define DBG_SET_FLAG_MIN(S,F) \ 380 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \ 381 tmp |= found = (1 << PMC_DEBUG_MIN_ ## F) 382 383 /* a '*' denotes all possible flags in the group */ 384 if (kwlen == 1 && *q == '*') 385 tmp = found = ~0; 386 /* look for individual flag names */ 387 DBG_SET_FLAG_MIN("allocaterow", ALR); 388 DBG_SET_FLAG_MIN("allocate", ALL); 389 DBG_SET_FLAG_MIN("attach", ATT); 390 DBG_SET_FLAG_MIN("bind", BND); 391 DBG_SET_FLAG_MIN("config", CFG); 392 DBG_SET_FLAG_MIN("exec", EXC); 393 DBG_SET_FLAG_MIN("exit", EXT); 394 DBG_SET_FLAG_MIN("find", FND); 395 DBG_SET_FLAG_MIN("flush", FLS); 396 DBG_SET_FLAG_MIN("fork", FRK); 397 DBG_SET_FLAG_MIN("getbuf", GTB); 398 DBG_SET_FLAG_MIN("hook", PMH); 399 DBG_SET_FLAG_MIN("init", INI); 400 DBG_SET_FLAG_MIN("intr", INT); 401 DBG_SET_FLAG_MIN("linktarget", TLK); 402 DBG_SET_FLAG_MIN("mayberemove", OMR); 403 DBG_SET_FLAG_MIN("ops", OPS); 404 DBG_SET_FLAG_MIN("read", REA); 405 DBG_SET_FLAG_MIN("register", REG); 406 DBG_SET_FLAG_MIN("release", REL); 407 DBG_SET_FLAG_MIN("remove", ORM); 408 DBG_SET_FLAG_MIN("sample", SAM); 409 DBG_SET_FLAG_MIN("scheduleio", SIO); 410 DBG_SET_FLAG_MIN("select", SEL); 411 DBG_SET_FLAG_MIN("signal", SIG); 412 DBG_SET_FLAG_MIN("swi", SWI); 413 DBG_SET_FLAG_MIN("swo", SWO); 414 DBG_SET_FLAG_MIN("start", STA); 415 DBG_SET_FLAG_MIN("stop", STO); 416 DBG_SET_FLAG_MIN("syscall", PMS); 417 DBG_SET_FLAG_MIN("unlinktarget", TUL); 418 DBG_SET_FLAG_MIN("write", WRI); 419 if (found == 0) { 420 /* unrecognized flag name */ 421 error = EINVAL; 422 goto done; 423 } 424 425 if (c == 0 || c == ' ' || c == '\t') { /* end of flag group */ 426 *newbits = tmp; 427 continue; 428 } 429 430 p++; 431 goto newflag; 432 } 433 434 /* save the new flag set */ 435 bcopy(tmpflags, &pmc_debugflags, sizeof(pmc_debugflags)); 436 437 done: 438 FREE(tmpflags, M_PMC); 439 return error; 440 } 441 442 static int 443 pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS) 444 { 445 char *fence, *newstr; 446 int error; 447 unsigned int n; 448 449 (void) arg1; (void) arg2; /* unused parameters */ 450 451 n = sizeof(pmc_debugstr); 452 MALLOC(newstr, char *, n, M_PMC, M_ZERO|M_WAITOK); 453 (void) strlcpy(newstr, pmc_debugstr, n); 454 455 error = sysctl_handle_string(oidp, newstr, n, req); 456 457 /* if there is a new string, parse and copy it */ 458 if (error == 0 && req->newptr != NULL) { 459 fence = newstr + (n < req->newlen ? n : req->newlen + 1); 460 if ((error = pmc_debugflags_parse(newstr, fence)) == 0) 461 (void) strlcpy(pmc_debugstr, newstr, 462 sizeof(pmc_debugstr)); 463 } 464 465 FREE(newstr, M_PMC); 466 467 return error; 468 } 469 #endif 470 471 /* 472 * Concurrency Control 473 * 474 * The driver manages the following data structures: 475 * 476 * - target process descriptors, one per target process 477 * - owner process descriptors (and attached lists), one per owner process 478 * - lookup hash tables for owner and target processes 479 * - PMC descriptors (and attached lists) 480 * - per-cpu hardware state 481 * - the 'hook' variable through which the kernel calls into 482 * this module 483 * - the machine hardware state (managed by the MD layer) 484 * 485 * These data structures are accessed from: 486 * 487 * - thread context-switch code 488 * - interrupt handlers (possibly on multiple cpus) 489 * - kernel threads on multiple cpus running on behalf of user 490 * processes doing system calls 491 * - this driver's private kernel threads 492 * 493 * = Locks and Locking strategy = 494 * 495 * The driver uses four locking strategies for its operation: 496 * 497 * - There is a 'global' SX lock "pmc_sx" that is used to protect 498 * the its 'meta-data'. 499 * 500 * Calls into the module (via syscall() or by the kernel) start with 501 * this lock being held in exclusive mode. Depending on the requested 502 * operation, the lock may be downgraded to 'shared' mode to allow 503 * more concurrent readers into the module. 504 * 505 * This SX lock is held in exclusive mode for any operations that 506 * modify the linkages between the driver's internal data structures. 507 * 508 * The 'pmc_hook' function pointer is also protected by this lock. 509 * It is only examined with the sx lock held in exclusive mode. The 510 * kernel module is allowed to be unloaded only with the sx lock 511 * held in exclusive mode. In normal syscall handling, after 512 * acquiring the pmc_sx lock we first check that 'pmc_hook' is 513 * non-null before proceeding. This prevents races between the 514 * thread unloading the module and other threads seeking to use the 515 * module. 516 * 517 * - Lookups of target process structures and owner process structures 518 * cannot use the global "pmc_sx" SX lock because these lookups need 519 * to happen during context switches and in other critical sections 520 * where sleeping is not allowed. We protect these lookup tables 521 * with their own private spin-mutexes, "pmc_processhash_mtx" and 522 * "pmc_ownerhash_mtx". These are 'leaf' mutexes, in that no other 523 * lock is acquired with these locks held. 524 * 525 * - Interrupt handlers work in a lock free manner. At interrupt 526 * time, handlers look at the PMC pointer (phw->phw_pmc) configured 527 * when the PMC was started. If this pointer is NULL, the interrupt 528 * is ignored after updating driver statistics. We ensure that this 529 * pointer is set (using an atomic operation if necessary) before the 530 * PMC hardware is started. Conversely, this pointer is unset atomically 531 * only after the PMC hardware is stopped. 532 * 533 * We ensure that everything needed for the operation of an 534 * interrupt handler is available without it needing to acquire any 535 * locks. We also ensure that a PMC's software state is destroyed only 536 * after the PMC is taken off hardware (on all CPUs). 537 * 538 * - Context-switch handling with process-private PMCs needs more 539 * care. 540 * 541 * A given process may be the target of multiple PMCs. For example, 542 * PMCATTACH and PMCDETACH may be requested by a process on one CPU 543 * while the target process is running on another. A PMC could also 544 * be getting released because its owner is exiting. We tackle 545 * these situations in the following manner: 546 * 547 * - each target process structure 'pmc_process' has an array 548 * of 'struct pmc *' pointers, one for each hardware PMC. 549 * 550 * - At context switch IN time, each "target" PMC in RUNNING state 551 * gets started on hardware and a pointer to each PMC is copied into 552 * the per-cpu phw array. The 'runcount' for the PMC is 553 * incremented. 554 * 555 * - At context switch OUT time, all process-virtual PMCs are stopped 556 * on hardware. The saved value is added to the PMCs value field 557 * only if the PMC is in a non-deleted state (the PMCs state could 558 * have changed during the current time slice). 559 * 560 * Note that since in-between a switch IN on a processor and a switch 561 * OUT, the PMC could have been released on another CPU. Therefore 562 * context switch OUT always looks at the hardware state to turn 563 * OFF PMCs and will update a PMC's saved value only if reachable 564 * from the target process record. 565 * 566 * - OP PMCRELEASE could be called on a PMC at any time (the PMC could 567 * be attached to many processes at the time of the call and could 568 * be active on multiple CPUs). 569 * 570 * We prevent further scheduling of the PMC by marking it as in 571 * state 'DELETED'. If the runcount of the PMC is non-zero then 572 * this PMC is currently running on a CPU somewhere. The thread 573 * doing the PMCRELEASE operation waits by repeatedly doing an 574 * tsleep() till the runcount comes to zero. 575 * 576 */ 577 578 /* 579 * save the cpu binding of the current kthread 580 */ 581 582 static void 583 pmc_save_cpu_binding(struct pmc_binding *pb) 584 { 585 PMCDBG(CPU,BND,2, "%s", "save-cpu"); 586 mtx_lock_spin(&sched_lock); 587 pb->pb_bound = sched_is_bound(curthread); 588 pb->pb_cpu = curthread->td_oncpu; 589 mtx_unlock_spin(&sched_lock); 590 PMCDBG(CPU,BND,2, "save-cpu cpu=%d", pb->pb_cpu); 591 } 592 593 /* 594 * restore the cpu binding of the current thread 595 */ 596 597 static void 598 pmc_restore_cpu_binding(struct pmc_binding *pb) 599 { 600 PMCDBG(CPU,BND,2, "restore-cpu curcpu=%d restore=%d", 601 curthread->td_oncpu, pb->pb_cpu); 602 mtx_lock_spin(&sched_lock); 603 if (pb->pb_bound) 604 sched_bind(curthread, pb->pb_cpu); 605 else 606 sched_unbind(curthread); 607 mtx_unlock_spin(&sched_lock); 608 PMCDBG(CPU,BND,2, "%s", "restore-cpu done"); 609 } 610 611 /* 612 * move execution over the specified cpu and bind it there. 613 */ 614 615 static void 616 pmc_select_cpu(int cpu) 617 { 618 KASSERT(cpu >= 0 && cpu < mp_ncpus, 619 ("[pmc,%d] bad cpu number %d", __LINE__, cpu)); 620 621 /* never move to a disabled CPU */ 622 KASSERT(pmc_cpu_is_disabled(cpu) == 0, ("[pmc,%d] selecting " 623 "disabled CPU %d", __LINE__, cpu)); 624 625 PMCDBG(CPU,SEL,2, "select-cpu cpu=%d", cpu); 626 mtx_lock_spin(&sched_lock); 627 sched_bind(curthread, cpu); 628 mtx_unlock_spin(&sched_lock); 629 630 KASSERT(curthread->td_oncpu == cpu, 631 ("[pmc,%d] CPU not bound [cpu=%d, curr=%d]", __LINE__, 632 cpu, curthread->td_oncpu)); 633 634 PMCDBG(CPU,SEL,2, "select-cpu cpu=%d ok", cpu); 635 } 636 637 /* 638 * Force a context switch. 639 * 640 * We do this by tsleep'ing for 1 tick -- invoking mi_switch() is not 641 * guaranteed to force a context switch. 642 */ 643 644 static void 645 pmc_force_context_switch(void) 646 { 647 u_char curpri; 648 649 mtx_lock_spin(&sched_lock); 650 curpri = curthread->td_priority; 651 mtx_unlock_spin(&sched_lock); 652 653 (void) tsleep((void *) pmc_force_context_switch, curpri, 654 "pmcctx", 1); 655 656 } 657 658 /* 659 * Get the file name for an executable. This is a simple wrapper 660 * around vn_fullpath(9). 661 */ 662 663 static void 664 pmc_getfilename(struct vnode *v, char **fullpath, char **freepath) 665 { 666 struct thread *td; 667 668 td = curthread; 669 *fullpath = "unknown"; 670 *freepath = NULL; 671 vn_lock(v, LK_CANRECURSE | LK_EXCLUSIVE | LK_RETRY, td); 672 vn_fullpath(td, v, fullpath, freepath); 673 VOP_UNLOCK(v, 0, td); 674 } 675 676 /* 677 * remove an process owning PMCs 678 */ 679 680 void 681 pmc_remove_owner(struct pmc_owner *po) 682 { 683 struct pmc *pm, *tmp; 684 685 sx_assert(&pmc_sx, SX_XLOCKED); 686 687 PMCDBG(OWN,ORM,1, "remove-owner po=%p", po); 688 689 /* Remove descriptor from the owner hash table */ 690 LIST_REMOVE(po, po_next); 691 692 /* release all owned PMC descriptors */ 693 LIST_FOREACH_SAFE(pm, &po->po_pmcs, pm_next, tmp) { 694 PMCDBG(OWN,ORM,2, "pmc=%p", pm); 695 KASSERT(pm->pm_owner == po, 696 ("[pmc,%d] owner %p != po %p", __LINE__, pm->pm_owner, po)); 697 698 pmc_release_pmc_descriptor(pm); /* will unlink from the list */ 699 } 700 701 KASSERT(po->po_sscount == 0, 702 ("[pmc,%d] SS count not zero", __LINE__)); 703 KASSERT(LIST_EMPTY(&po->po_pmcs), 704 ("[pmc,%d] PMC list not empty", __LINE__)); 705 706 /* de-configure the log file if present */ 707 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 708 pmclog_deconfigure_log(po); 709 } 710 711 /* 712 * remove an owner process record if all conditions are met. 713 */ 714 715 static void 716 pmc_maybe_remove_owner(struct pmc_owner *po) 717 { 718 719 PMCDBG(OWN,OMR,1, "maybe-remove-owner po=%p", po); 720 721 /* 722 * Remove owner record if 723 * - this process does not own any PMCs 724 * - this process has not allocated a system-wide sampling buffer 725 */ 726 727 if (LIST_EMPTY(&po->po_pmcs) && 728 ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0)) { 729 pmc_remove_owner(po); 730 pmc_destroy_owner_descriptor(po); 731 } 732 } 733 734 /* 735 * Add an association between a target process and a PMC. 736 */ 737 738 static void 739 pmc_link_target_process(struct pmc *pm, struct pmc_process *pp) 740 { 741 int ri; 742 struct pmc_target *pt; 743 744 sx_assert(&pmc_sx, SX_XLOCKED); 745 746 KASSERT(pm != NULL && pp != NULL, 747 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 748 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 749 ("[pmc,%d] Attaching a non-process-virtual pmc=%p to pid=%d", 750 __LINE__, pm, pp->pp_proc->p_pid)); 751 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt < ((int) md->pmd_npmc - 1), 752 ("[pmc,%d] Illegal reference count %d for process record %p", 753 __LINE__, pp->pp_refcnt, (void *) pp)); 754 755 ri = PMC_TO_ROWINDEX(pm); 756 757 PMCDBG(PRC,TLK,1, "link-target pmc=%p ri=%d pmc-process=%p", 758 pm, ri, pp); 759 760 #if DEBUG 761 LIST_FOREACH(pt, &pm->pm_targets, pt_next) 762 if (pt->pt_process == pp) 763 KASSERT(0, ("[pmc,%d] pp %p already in pmc %p targets", 764 __LINE__, pp, pm)); 765 #endif 766 767 MALLOC(pt, struct pmc_target *, sizeof(struct pmc_target), 768 M_PMC, M_ZERO|M_WAITOK); 769 770 pt->pt_process = pp; 771 772 LIST_INSERT_HEAD(&pm->pm_targets, pt, pt_next); 773 774 atomic_store_rel_ptr((uintptr_t *)&pp->pp_pmcs[ri].pp_pmc, 775 (uintptr_t)pm); 776 777 if (pm->pm_owner->po_owner == pp->pp_proc) 778 pm->pm_flags |= PMC_F_ATTACHED_TO_OWNER; 779 780 /* 781 * Initialize the per-process values at this row index. 782 */ 783 pp->pp_pmcs[ri].pp_pmcval = PMC_TO_MODE(pm) == PMC_MODE_TS ? 784 pm->pm_sc.pm_reloadcount : 0; 785 786 pp->pp_refcnt++; 787 788 } 789 790 /* 791 * Removes the association between a target process and a PMC. 792 */ 793 794 static void 795 pmc_unlink_target_process(struct pmc *pm, struct pmc_process *pp) 796 { 797 int ri; 798 struct proc *p; 799 struct pmc_target *ptgt; 800 801 sx_assert(&pmc_sx, SX_XLOCKED); 802 803 KASSERT(pm != NULL && pp != NULL, 804 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 805 806 KASSERT(pp->pp_refcnt >= 1 && pp->pp_refcnt < (int) md->pmd_npmc, 807 ("[pmc,%d] Illegal ref count %d on process record %p", 808 __LINE__, pp->pp_refcnt, (void *) pp)); 809 810 ri = PMC_TO_ROWINDEX(pm); 811 812 PMCDBG(PRC,TUL,1, "unlink-target pmc=%p ri=%d pmc-process=%p", 813 pm, ri, pp); 814 815 KASSERT(pp->pp_pmcs[ri].pp_pmc == pm, 816 ("[pmc,%d] PMC ri %d mismatch pmc %p pp->[ri] %p", __LINE__, 817 ri, pm, pp->pp_pmcs[ri].pp_pmc)); 818 819 pp->pp_pmcs[ri].pp_pmc = NULL; 820 pp->pp_pmcs[ri].pp_pmcval = (pmc_value_t) 0; 821 822 /* Remove owner-specific flags */ 823 if (pm->pm_owner->po_owner == pp->pp_proc) { 824 pp->pp_flags &= ~PMC_PP_ENABLE_MSR_ACCESS; 825 pm->pm_flags &= ~PMC_F_ATTACHED_TO_OWNER; 826 } 827 828 pp->pp_refcnt--; 829 830 /* Remove the target process from the PMC structure */ 831 LIST_FOREACH(ptgt, &pm->pm_targets, pt_next) 832 if (ptgt->pt_process == pp) 833 break; 834 835 KASSERT(ptgt != NULL, ("[pmc,%d] process %p (pp: %p) not found " 836 "in pmc %p", __LINE__, pp->pp_proc, pp, pm)); 837 838 LIST_REMOVE(ptgt, pt_next); 839 FREE(ptgt, M_PMC); 840 841 /* if the PMC now lacks targets, send the owner a SIGIO */ 842 if (LIST_EMPTY(&pm->pm_targets)) { 843 p = pm->pm_owner->po_owner; 844 PROC_LOCK(p); 845 psignal(p, SIGIO); 846 PROC_UNLOCK(p); 847 848 PMCDBG(PRC,SIG,2, "signalling proc=%p signal=%d", p, 849 SIGIO); 850 } 851 } 852 853 /* 854 * Check if PMC 'pm' may be attached to target process 't'. 855 */ 856 857 static int 858 pmc_can_attach(struct pmc *pm, struct proc *t) 859 { 860 struct proc *o; /* pmc owner */ 861 struct ucred *oc, *tc; /* owner, target credentials */ 862 int decline_attach, i; 863 864 /* 865 * A PMC's owner can always attach that PMC to itself. 866 */ 867 868 if ((o = pm->pm_owner->po_owner) == t) 869 return 0; 870 871 PROC_LOCK(o); 872 oc = o->p_ucred; 873 crhold(oc); 874 PROC_UNLOCK(o); 875 876 PROC_LOCK(t); 877 tc = t->p_ucred; 878 crhold(tc); 879 PROC_UNLOCK(t); 880 881 /* 882 * The effective uid of the PMC owner should match at least one 883 * of the {effective,real,saved} uids of the target process. 884 */ 885 886 decline_attach = oc->cr_uid != tc->cr_uid && 887 oc->cr_uid != tc->cr_svuid && 888 oc->cr_uid != tc->cr_ruid; 889 890 /* 891 * Every one of the target's group ids, must be in the owner's 892 * group list. 893 */ 894 for (i = 0; !decline_attach && i < tc->cr_ngroups; i++) 895 decline_attach = !groupmember(tc->cr_groups[i], oc); 896 897 /* check the read and saved gids too */ 898 if (decline_attach == 0) 899 decline_attach = !groupmember(tc->cr_rgid, oc) || 900 !groupmember(tc->cr_svgid, oc); 901 902 crfree(tc); 903 crfree(oc); 904 905 return !decline_attach; 906 } 907 908 /* 909 * Attach a process to a PMC. 910 */ 911 912 static int 913 pmc_attach_one_process(struct proc *p, struct pmc *pm) 914 { 915 int ri; 916 char *fullpath, *freepath; 917 struct pmc_process *pp; 918 919 sx_assert(&pmc_sx, SX_XLOCKED); 920 921 PMCDBG(PRC,ATT,2, "attach-one pm=%p ri=%d proc=%p (%d, %s)", pm, 922 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 923 924 /* 925 * Locate the process descriptor corresponding to process 'p', 926 * allocating space as needed. 927 * 928 * Verify that rowindex 'pm_rowindex' is free in the process 929 * descriptor. 930 * 931 * If not, allocate space for a descriptor and link the 932 * process descriptor and PMC. 933 */ 934 ri = PMC_TO_ROWINDEX(pm); 935 936 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_ALLOCATE)) == NULL) 937 return ENOMEM; 938 939 if (pp->pp_pmcs[ri].pp_pmc == pm) /* already present at slot [ri] */ 940 return EEXIST; 941 942 if (pp->pp_pmcs[ri].pp_pmc != NULL) 943 return EBUSY; 944 945 pmc_link_target_process(pm, pp); 946 947 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) && 948 (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) == 0) 949 pm->pm_flags |= PMC_F_NEEDS_LOGFILE; 950 951 pm->pm_flags |= PMC_F_ATTACH_DONE; /* mark as attached */ 952 953 /* issue an attach event to a configured log file */ 954 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) { 955 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 956 pmclog_process_pmcattach(pm, p->p_pid, fullpath); 957 if (freepath) 958 FREE(freepath, M_TEMP); 959 } 960 /* mark process as using HWPMCs */ 961 PROC_LOCK(p); 962 p->p_flag |= P_HWPMC; 963 PROC_UNLOCK(p); 964 965 return 0; 966 } 967 968 /* 969 * Attach a process and optionally its children 970 */ 971 972 static int 973 pmc_attach_process(struct proc *p, struct pmc *pm) 974 { 975 int error; 976 struct proc *top; 977 978 sx_assert(&pmc_sx, SX_XLOCKED); 979 980 PMCDBG(PRC,ATT,1, "attach pm=%p ri=%d proc=%p (%d, %s)", pm, 981 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 982 983 984 /* 985 * If this PMC successfully allowed a GETMSR operation 986 * in the past, disallow further ATTACHes. 987 */ 988 989 if ((pm->pm_flags & PMC_PP_ENABLE_MSR_ACCESS) != 0) 990 return EPERM; 991 992 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 993 return pmc_attach_one_process(p, pm); 994 995 /* 996 * Traverse all child processes, attaching them to 997 * this PMC. 998 */ 999 1000 sx_slock(&proctree_lock); 1001 1002 top = p; 1003 1004 for (;;) { 1005 if ((error = pmc_attach_one_process(p, pm)) != 0) 1006 break; 1007 if (!LIST_EMPTY(&p->p_children)) 1008 p = LIST_FIRST(&p->p_children); 1009 else for (;;) { 1010 if (p == top) 1011 goto done; 1012 if (LIST_NEXT(p, p_sibling)) { 1013 p = LIST_NEXT(p, p_sibling); 1014 break; 1015 } 1016 p = p->p_pptr; 1017 } 1018 } 1019 1020 if (error) 1021 (void) pmc_detach_process(top, pm); 1022 1023 done: 1024 sx_sunlock(&proctree_lock); 1025 return error; 1026 } 1027 1028 /* 1029 * Detach a process from a PMC. If there are no other PMCs tracking 1030 * this process, remove the process structure from its hash table. If 1031 * 'flags' contains PMC_FLAG_REMOVE, then free the process structure. 1032 */ 1033 1034 static int 1035 pmc_detach_one_process(struct proc *p, struct pmc *pm, int flags) 1036 { 1037 int ri; 1038 struct pmc_process *pp; 1039 1040 sx_assert(&pmc_sx, SX_XLOCKED); 1041 1042 KASSERT(pm != NULL, 1043 ("[pmc,%d] null pm pointer", __LINE__)); 1044 1045 ri = PMC_TO_ROWINDEX(pm); 1046 1047 PMCDBG(PRC,ATT,2, "detach-one pm=%p ri=%d proc=%p (%d, %s) flags=0x%x", 1048 pm, ri, p, p->p_pid, p->p_comm, flags); 1049 1050 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) 1051 return ESRCH; 1052 1053 if (pp->pp_pmcs[ri].pp_pmc != pm) 1054 return EINVAL; 1055 1056 pmc_unlink_target_process(pm, pp); 1057 1058 /* Issue a detach entry if a log file is configured */ 1059 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) 1060 pmclog_process_pmcdetach(pm, p->p_pid); 1061 1062 /* 1063 * If there are no PMCs targetting this process, we remove its 1064 * descriptor from the target hash table and unset the P_HWPMC 1065 * flag in the struct proc. 1066 */ 1067 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt < (int) md->pmd_npmc, 1068 ("[pmc,%d] Illegal refcnt %d for process struct %p", 1069 __LINE__, pp->pp_refcnt, pp)); 1070 1071 if (pp->pp_refcnt != 0) /* still a target of some PMC */ 1072 return 0; 1073 1074 pmc_remove_process_descriptor(pp); 1075 1076 if (flags & PMC_FLAG_REMOVE) 1077 FREE(pp, M_PMC); 1078 1079 PROC_LOCK(p); 1080 p->p_flag &= ~P_HWPMC; 1081 PROC_UNLOCK(p); 1082 1083 return 0; 1084 } 1085 1086 /* 1087 * Detach a process and optionally its descendants from a PMC. 1088 */ 1089 1090 static int 1091 pmc_detach_process(struct proc *p, struct pmc *pm) 1092 { 1093 struct proc *top; 1094 1095 sx_assert(&pmc_sx, SX_XLOCKED); 1096 1097 PMCDBG(PRC,ATT,1, "detach pm=%p ri=%d proc=%p (%d, %s)", pm, 1098 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1099 1100 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 1101 return pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); 1102 1103 /* 1104 * Traverse all children, detaching them from this PMC. We 1105 * ignore errors since we could be detaching a PMC from a 1106 * partially attached proc tree. 1107 */ 1108 1109 sx_slock(&proctree_lock); 1110 1111 top = p; 1112 1113 for (;;) { 1114 (void) pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); 1115 1116 if (!LIST_EMPTY(&p->p_children)) 1117 p = LIST_FIRST(&p->p_children); 1118 else for (;;) { 1119 if (p == top) 1120 goto done; 1121 if (LIST_NEXT(p, p_sibling)) { 1122 p = LIST_NEXT(p, p_sibling); 1123 break; 1124 } 1125 p = p->p_pptr; 1126 } 1127 } 1128 1129 done: 1130 sx_sunlock(&proctree_lock); 1131 1132 if (LIST_EMPTY(&pm->pm_targets)) 1133 pm->pm_flags &= ~PMC_F_ATTACH_DONE; 1134 1135 return 0; 1136 } 1137 1138 1139 /* 1140 * Thread context switch IN 1141 */ 1142 1143 static void 1144 pmc_process_csw_in(struct thread *td) 1145 { 1146 int cpu; 1147 unsigned int ri; 1148 struct pmc *pm; 1149 struct proc *p; 1150 struct pmc_cpu *pc; 1151 struct pmc_hw *phw; 1152 struct pmc_process *pp; 1153 pmc_value_t newvalue; 1154 1155 p = td->td_proc; 1156 1157 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE)) == NULL) 1158 return; 1159 1160 KASSERT(pp->pp_proc == td->td_proc, 1161 ("[pmc,%d] not my thread state", __LINE__)); 1162 1163 critical_enter(); /* no preemption from this point */ 1164 1165 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1166 1167 PMCDBG(CSW,SWI,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1168 p->p_pid, p->p_comm, pp); 1169 1170 KASSERT(cpu >= 0 && cpu < mp_ncpus, 1171 ("[pmc,%d] wierd CPU id %d", __LINE__, cpu)); 1172 1173 pc = pmc_pcpu[cpu]; 1174 1175 for (ri = 0; ri < md->pmd_npmc; ri++) { 1176 1177 if ((pm = pp->pp_pmcs[ri].pp_pmc) == NULL) 1178 continue; 1179 1180 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 1181 ("[pmc,%d] Target PMC in non-virtual mode (%d)", 1182 __LINE__, PMC_TO_MODE(pm))); 1183 1184 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1185 ("[pmc,%d] Row index mismatch pmc %d != ri %d", 1186 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1187 1188 /* 1189 * Only PMCs that are marked as 'RUNNING' need 1190 * be placed on hardware. 1191 */ 1192 1193 if (pm->pm_state != PMC_STATE_RUNNING) 1194 continue; 1195 1196 /* increment PMC runcount */ 1197 atomic_add_rel_32(&pm->pm_runcount, 1); 1198 1199 /* configure the HWPMC we are going to use. */ 1200 md->pmd_config_pmc(cpu, ri, pm); 1201 1202 phw = pc->pc_hwpmcs[ri]; 1203 1204 KASSERT(phw != NULL, 1205 ("[pmc,%d] null hw pointer", __LINE__)); 1206 1207 KASSERT(phw->phw_pmc == pm, 1208 ("[pmc,%d] hw->pmc %p != pmc %p", __LINE__, 1209 phw->phw_pmc, pm)); 1210 1211 /* 1212 * Write out saved value and start the PMC. 1213 * 1214 * Sampling PMCs use a per-process value, while 1215 * counting mode PMCs use a per-pmc value that is 1216 * inherited across descendants. 1217 */ 1218 if (PMC_TO_MODE(pm) == PMC_MODE_TS) { 1219 mtx_pool_lock_spin(pmc_mtxpool, pm); 1220 newvalue = PMC_PCPU_SAVED(cpu,ri) = 1221 pp->pp_pmcs[ri].pp_pmcval; 1222 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1223 } else { 1224 KASSERT(PMC_TO_MODE(pm) == PMC_MODE_TC, 1225 ("[pmc,%d] illegal mode=%d", __LINE__, 1226 PMC_TO_MODE(pm))); 1227 mtx_pool_lock_spin(pmc_mtxpool, pm); 1228 newvalue = PMC_PCPU_SAVED(cpu, ri) = 1229 pm->pm_gv.pm_savedvalue; 1230 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1231 } 1232 1233 PMCDBG(CSW,SWI,1,"cpu=%d ri=%d new=%jd", cpu, ri, newvalue); 1234 1235 md->pmd_write_pmc(cpu, ri, newvalue); 1236 md->pmd_start_pmc(cpu, ri); 1237 } 1238 1239 /* 1240 * perform any other architecture/cpu dependent thread 1241 * switch-in actions. 1242 */ 1243 1244 (void) (*md->pmd_switch_in)(pc, pp); 1245 1246 critical_exit(); 1247 1248 } 1249 1250 /* 1251 * Thread context switch OUT. 1252 */ 1253 1254 static void 1255 pmc_process_csw_out(struct thread *td) 1256 { 1257 int cpu; 1258 enum pmc_mode mode; 1259 unsigned int ri; 1260 struct pmc *pm; 1261 struct proc *p; 1262 struct pmc_cpu *pc; 1263 struct pmc_process *pp; 1264 int64_t tmp; 1265 pmc_value_t newvalue; 1266 1267 /* 1268 * Locate our process descriptor; this may be NULL if 1269 * this process is exiting and we have already removed 1270 * the process from the target process table. 1271 * 1272 * Note that due to kernel preemption, multiple 1273 * context switches may happen while the process is 1274 * exiting. 1275 * 1276 * Note also that if the target process cannot be 1277 * found we still need to deconfigure any PMCs that 1278 * are currently running on hardware. 1279 */ 1280 1281 p = td->td_proc; 1282 pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE); 1283 1284 /* 1285 * save PMCs 1286 */ 1287 1288 critical_enter(); 1289 1290 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1291 1292 PMCDBG(CSW,SWO,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1293 p->p_pid, p->p_comm, pp); 1294 1295 KASSERT(cpu >= 0 && cpu < mp_ncpus, 1296 ("[pmc,%d wierd CPU id %d", __LINE__, cpu)); 1297 1298 pc = pmc_pcpu[cpu]; 1299 1300 /* 1301 * When a PMC gets unlinked from a target PMC, it will 1302 * be removed from the target's pp_pmc[] array. 1303 * 1304 * However, on a MP system, the target could have been 1305 * executing on another CPU at the time of the unlink. 1306 * So, at context switch OUT time, we need to look at 1307 * the hardware to determine if a PMC is scheduled on 1308 * it. 1309 */ 1310 1311 for (ri = 0; ri < md->pmd_npmc; ri++) { 1312 1313 pm = NULL; 1314 (void) (*md->pmd_get_config)(cpu, ri, &pm); 1315 1316 if (pm == NULL) /* nothing at this row index */ 1317 continue; 1318 1319 mode = PMC_TO_MODE(pm); 1320 if (!PMC_IS_VIRTUAL_MODE(mode)) 1321 continue; /* not a process virtual PMC */ 1322 1323 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1324 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 1325 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1326 1327 /* Stop hardware if not already stopped */ 1328 if (pm->pm_stalled == 0) 1329 md->pmd_stop_pmc(cpu, ri); 1330 1331 /* reduce this PMC's runcount */ 1332 atomic_subtract_rel_32(&pm->pm_runcount, 1); 1333 1334 /* 1335 * If this PMC is associated with this process, 1336 * save the reading. 1337 */ 1338 1339 if (pp != NULL && pp->pp_pmcs[ri].pp_pmc != NULL) { 1340 1341 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 1342 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", __LINE__, 1343 pm, ri, pp->pp_pmcs[ri].pp_pmc)); 1344 1345 KASSERT(pp->pp_refcnt > 0, 1346 ("[pmc,%d] pp refcnt = %d", __LINE__, 1347 pp->pp_refcnt)); 1348 1349 md->pmd_read_pmc(cpu, ri, &newvalue); 1350 1351 tmp = newvalue - PMC_PCPU_SAVED(cpu,ri); 1352 1353 PMCDBG(CSW,SWI,1,"cpu=%d ri=%d tmp=%jd", cpu, ri, 1354 tmp); 1355 1356 if (mode == PMC_MODE_TS) { 1357 1358 /* 1359 * For sampling process-virtual PMCs, 1360 * we expect the count to be 1361 * decreasing as the 'value' 1362 * programmed into the PMC is the 1363 * number of events to be seen till 1364 * the next sampling interrupt. 1365 */ 1366 if (tmp < 0) 1367 tmp += pm->pm_sc.pm_reloadcount; 1368 mtx_pool_lock_spin(pmc_mtxpool, pm); 1369 pp->pp_pmcs[ri].pp_pmcval -= tmp; 1370 if ((int64_t) pp->pp_pmcs[ri].pp_pmcval < 0) 1371 pp->pp_pmcs[ri].pp_pmcval += 1372 pm->pm_sc.pm_reloadcount; 1373 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1374 1375 } else { 1376 1377 /* 1378 * For counting process-virtual PMCs, 1379 * we expect the count to be 1380 * increasing monotonically, modulo a 64 1381 * bit wraparound. 1382 */ 1383 KASSERT((int64_t) tmp >= 0, 1384 ("[pmc,%d] negative increment cpu=%d " 1385 "ri=%d newvalue=%jx saved=%jx " 1386 "incr=%jx", __LINE__, cpu, ri, 1387 newvalue, PMC_PCPU_SAVED(cpu,ri), tmp)); 1388 1389 mtx_pool_lock_spin(pmc_mtxpool, pm); 1390 pm->pm_gv.pm_savedvalue += tmp; 1391 pp->pp_pmcs[ri].pp_pmcval += tmp; 1392 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1393 1394 if (pm->pm_flags & PMC_F_LOG_PROCCSW) 1395 pmclog_process_proccsw(pm, pp, tmp); 1396 } 1397 } 1398 1399 /* mark hardware as free */ 1400 md->pmd_config_pmc(cpu, ri, NULL); 1401 } 1402 1403 /* 1404 * perform any other architecture/cpu dependent thread 1405 * switch out functions. 1406 */ 1407 1408 (void) (*md->pmd_switch_out)(pc, pp); 1409 1410 critical_exit(); 1411 } 1412 1413 /* 1414 * The 'hook' invoked from the kernel proper 1415 */ 1416 1417 1418 #if DEBUG 1419 const char *pmc_hooknames[] = { 1420 "", 1421 "EXIT", 1422 "EXEC", 1423 "FORK", 1424 "CSW-IN", 1425 "CSW-OUT", 1426 "SAMPLE" 1427 }; 1428 #endif 1429 1430 static int 1431 pmc_hook_handler(struct thread *td, int function, void *arg) 1432 { 1433 1434 PMCDBG(MOD,PMH,1, "hook td=%p func=%d \"%s\" arg=%p", td, function, 1435 pmc_hooknames[function], arg); 1436 1437 switch (function) 1438 { 1439 1440 /* 1441 * Process exec() 1442 */ 1443 1444 case PMC_FN_PROCESS_EXEC: 1445 { 1446 char *fullpath, *freepath; 1447 unsigned int ri; 1448 int is_using_hwpmcs; 1449 struct pmc *pm; 1450 struct proc *p; 1451 struct pmc_owner *po; 1452 struct pmc_process *pp; 1453 struct pmckern_procexec *pk; 1454 1455 sx_assert(&pmc_sx, SX_XLOCKED); 1456 1457 p = td->td_proc; 1458 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 1459 1460 pk = (struct pmckern_procexec *) arg; 1461 1462 /* Inform owners of SS mode PMCs of the exec event. */ 1463 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1464 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1465 pmclog_process_procexec(po, PMC_ID_INVALID, 1466 p->p_pid, pk->pm_entryaddr, fullpath); 1467 1468 PROC_LOCK(p); 1469 is_using_hwpmcs = p->p_flag & P_HWPMC; 1470 PROC_UNLOCK(p); 1471 1472 if (!is_using_hwpmcs) { 1473 if (freepath) 1474 FREE(freepath, M_TEMP); 1475 break; 1476 } 1477 1478 /* 1479 * PMCs are not inherited across an exec(): remove any 1480 * PMCs that this process is the owner of. 1481 */ 1482 1483 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 1484 pmc_remove_owner(po); 1485 pmc_destroy_owner_descriptor(po); 1486 } 1487 1488 /* 1489 * If this process is the target of a PMC, check if the new 1490 * credentials are compatible with the owner's permissions. 1491 */ 1492 1493 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) 1494 break; 1495 1496 /* 1497 * Log the exec event to all monitoring owners. Skip 1498 * owners who have already recieved the event because 1499 * the have system sampling PMCs active. 1500 */ 1501 for (ri = 0; ri < md->pmd_npmc; ri++) 1502 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 1503 po = pm->pm_owner; 1504 if (po->po_sscount == 0 && 1505 po->po_flags & PMC_PO_OWNS_LOGFILE) 1506 pmclog_process_procexec(po, pm->pm_id, 1507 p->p_pid, pk->pm_entryaddr, 1508 fullpath); 1509 } 1510 1511 if (freepath) 1512 FREE(freepath, M_TEMP); 1513 1514 1515 PMCDBG(PRC,EXC,1, "exec proc=%p (%d, %s) cred-changed=%d", 1516 p, p->p_pid, p->p_comm, pk->pm_credentialschanged); 1517 1518 if (pk->pm_credentialschanged == 0) /* no change */ 1519 break; 1520 1521 /* 1522 * If the newly exec()'ed process has a different credential 1523 * than before, allow it to be the target of a PMC only if 1524 * the PMC's owner has sufficient priviledge. 1525 */ 1526 1527 for (ri = 0; ri < md->pmd_npmc; ri++) 1528 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) 1529 if (pmc_can_attach(pm, td->td_proc) != 0) 1530 pmc_detach_one_process(td->td_proc, 1531 pm, PMC_FLAG_NONE); 1532 1533 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt < (int) md->pmd_npmc, 1534 ("[pmc,%d] Illegal ref count %d on pp %p", __LINE__, 1535 pp->pp_refcnt, pp)); 1536 1537 /* 1538 * If this process is no longer the target of any 1539 * PMCs, we can remove the process entry and free 1540 * up space. 1541 */ 1542 1543 if (pp->pp_refcnt == 0) { 1544 pmc_remove_process_descriptor(pp); 1545 FREE(pp, M_PMC); 1546 break; 1547 } 1548 1549 } 1550 break; 1551 1552 case PMC_FN_CSW_IN: 1553 pmc_process_csw_in(td); 1554 break; 1555 1556 case PMC_FN_CSW_OUT: 1557 pmc_process_csw_out(td); 1558 break; 1559 1560 /* 1561 * Process accumulated PC samples. 1562 * 1563 * This function is expected to be called by hardclock() for 1564 * each CPU that has accumulated PC samples. 1565 * 1566 * This function is to be executed on the CPU whose samples 1567 * are being processed. 1568 */ 1569 case PMC_FN_DO_SAMPLES: 1570 1571 /* 1572 * Clear the cpu specific bit in the CPU mask before 1573 * do the rest of the processing. If the NMI handler 1574 * gets invoked after the "atomic_clear_int()" call 1575 * below but before "pmc_process_samples()" gets 1576 * around to processing the interrupt, then we will 1577 * come back here at the next hardclock() tick (and 1578 * may find nothing to do if "pmc_process_samples()" 1579 * had already processed the interrupt). We don't 1580 * lose the interrupt sample. 1581 */ 1582 atomic_clear_int(&pmc_cpumask, (1 << PCPU_GET(cpuid))); 1583 pmc_process_samples(PCPU_GET(cpuid)); 1584 break; 1585 1586 default: 1587 #if DEBUG 1588 KASSERT(0, ("[pmc,%d] unknown hook %d\n", __LINE__, function)); 1589 #endif 1590 break; 1591 1592 } 1593 1594 return 0; 1595 } 1596 1597 /* 1598 * allocate a 'struct pmc_owner' descriptor in the owner hash table. 1599 */ 1600 1601 static struct pmc_owner * 1602 pmc_allocate_owner_descriptor(struct proc *p) 1603 { 1604 uint32_t hindex; 1605 struct pmc_owner *po; 1606 struct pmc_ownerhash *poh; 1607 1608 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 1609 poh = &pmc_ownerhash[hindex]; 1610 1611 /* allocate space for N pointers and one descriptor struct */ 1612 MALLOC(po, struct pmc_owner *, sizeof(struct pmc_owner), 1613 M_PMC, M_ZERO|M_WAITOK); 1614 1615 po->po_sscount = po->po_error = po->po_flags = 0; 1616 po->po_file = NULL; 1617 po->po_owner = p; 1618 po->po_kthread = NULL; 1619 LIST_INIT(&po->po_pmcs); 1620 LIST_INSERT_HEAD(poh, po, po_next); /* insert into hash table */ 1621 1622 TAILQ_INIT(&po->po_logbuffers); 1623 mtx_init(&po->po_mtx, "pmc-owner-mtx", "pmc", MTX_SPIN); 1624 1625 PMCDBG(OWN,ALL,1, "allocate-owner proc=%p (%d, %s) pmc-owner=%p", 1626 p, p->p_pid, p->p_comm, po); 1627 1628 return po; 1629 } 1630 1631 static void 1632 pmc_destroy_owner_descriptor(struct pmc_owner *po) 1633 { 1634 1635 PMCDBG(OWN,REL,1, "destroy-owner po=%p proc=%p (%d, %s)", 1636 po, po->po_owner, po->po_owner->p_pid, po->po_owner->p_comm); 1637 1638 mtx_destroy(&po->po_mtx); 1639 FREE(po, M_PMC); 1640 } 1641 1642 /* 1643 * find the descriptor corresponding to process 'p', adding or removing it 1644 * as specified by 'mode'. 1645 */ 1646 1647 static struct pmc_process * 1648 pmc_find_process_descriptor(struct proc *p, uint32_t mode) 1649 { 1650 uint32_t hindex; 1651 struct pmc_process *pp, *ppnew; 1652 struct pmc_processhash *pph; 1653 1654 hindex = PMC_HASH_PTR(p, pmc_processhashmask); 1655 pph = &pmc_processhash[hindex]; 1656 1657 ppnew = NULL; 1658 1659 /* 1660 * Pre-allocate memory in the FIND_ALLOCATE case since we 1661 * cannot call malloc(9) once we hold a spin lock. 1662 */ 1663 1664 if (mode & PMC_FLAG_ALLOCATE) { 1665 /* allocate additional space for 'n' pmc pointers */ 1666 MALLOC(ppnew, struct pmc_process *, 1667 sizeof(struct pmc_process) + md->pmd_npmc * 1668 sizeof(struct pmc_targetstate), M_PMC, M_ZERO|M_WAITOK); 1669 } 1670 1671 mtx_lock_spin(&pmc_processhash_mtx); 1672 LIST_FOREACH(pp, pph, pp_next) 1673 if (pp->pp_proc == p) 1674 break; 1675 1676 if ((mode & PMC_FLAG_REMOVE) && pp != NULL) 1677 LIST_REMOVE(pp, pp_next); 1678 1679 if ((mode & PMC_FLAG_ALLOCATE) && pp == NULL && 1680 ppnew != NULL) { 1681 ppnew->pp_proc = p; 1682 LIST_INSERT_HEAD(pph, ppnew, pp_next); 1683 pp = ppnew; 1684 ppnew = NULL; 1685 } 1686 mtx_unlock_spin(&pmc_processhash_mtx); 1687 1688 if (pp != NULL && ppnew != NULL) 1689 FREE(ppnew, M_PMC); 1690 1691 return pp; 1692 } 1693 1694 /* 1695 * remove a process descriptor from the process hash table. 1696 */ 1697 1698 static void 1699 pmc_remove_process_descriptor(struct pmc_process *pp) 1700 { 1701 KASSERT(pp->pp_refcnt == 0, 1702 ("[pmc,%d] Removing process descriptor %p with count %d", 1703 __LINE__, pp, pp->pp_refcnt)); 1704 1705 mtx_lock_spin(&pmc_processhash_mtx); 1706 LIST_REMOVE(pp, pp_next); 1707 mtx_unlock_spin(&pmc_processhash_mtx); 1708 } 1709 1710 1711 /* 1712 * find an owner descriptor corresponding to proc 'p' 1713 */ 1714 1715 static struct pmc_owner * 1716 pmc_find_owner_descriptor(struct proc *p) 1717 { 1718 uint32_t hindex; 1719 struct pmc_owner *po; 1720 struct pmc_ownerhash *poh; 1721 1722 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 1723 poh = &pmc_ownerhash[hindex]; 1724 1725 po = NULL; 1726 LIST_FOREACH(po, poh, po_next) 1727 if (po->po_owner == p) 1728 break; 1729 1730 PMCDBG(OWN,FND,1, "find-owner proc=%p (%d, %s) hindex=0x%x -> " 1731 "pmc-owner=%p", p, p->p_pid, p->p_comm, hindex, po); 1732 1733 return po; 1734 } 1735 1736 /* 1737 * pmc_allocate_pmc_descriptor 1738 * 1739 * Allocate a pmc descriptor and initialize its 1740 * fields. 1741 */ 1742 1743 static struct pmc * 1744 pmc_allocate_pmc_descriptor(void) 1745 { 1746 struct pmc *pmc; 1747 1748 MALLOC(pmc, struct pmc *, sizeof(struct pmc), M_PMC, M_ZERO|M_WAITOK); 1749 1750 if (pmc != NULL) { 1751 pmc->pm_owner = NULL; 1752 LIST_INIT(&pmc->pm_targets); 1753 } 1754 1755 PMCDBG(PMC,ALL,1, "allocate-pmc -> pmc=%p", pmc); 1756 1757 return pmc; 1758 } 1759 1760 /* 1761 * Destroy a pmc descriptor. 1762 */ 1763 1764 static void 1765 pmc_destroy_pmc_descriptor(struct pmc *pm) 1766 { 1767 (void) pm; 1768 1769 #if DEBUG 1770 KASSERT(pm->pm_state == PMC_STATE_DELETED || 1771 pm->pm_state == PMC_STATE_FREE, 1772 ("[pmc,%d] destroying non-deleted PMC", __LINE__)); 1773 KASSERT(LIST_EMPTY(&pm->pm_targets), 1774 ("[pmc,%d] destroying pmc with targets", __LINE__)); 1775 KASSERT(pm->pm_owner == NULL, 1776 ("[pmc,%d] destroying pmc attached to an owner", __LINE__)); 1777 KASSERT(pm->pm_runcount == 0, 1778 ("[pmc,%d] pmc has non-zero run count %d", __LINE__, 1779 pm->pm_runcount)); 1780 #endif 1781 } 1782 1783 static void 1784 pmc_wait_for_pmc_idle(struct pmc *pm) 1785 { 1786 #if DEBUG 1787 volatile int maxloop; 1788 1789 maxloop = 100 * mp_ncpus; 1790 #endif 1791 1792 /* 1793 * Loop (with a forced context switch) till the PMC's runcount 1794 * comes down to zero. 1795 */ 1796 while (atomic_load_acq_32(&pm->pm_runcount) > 0) { 1797 #if DEBUG 1798 maxloop--; 1799 KASSERT(maxloop > 0, 1800 ("[pmc,%d] (ri%d, rc%d) waiting too long for " 1801 "pmc to be free", __LINE__, 1802 PMC_TO_ROWINDEX(pm), pm->pm_runcount)); 1803 #endif 1804 pmc_force_context_switch(); 1805 } 1806 } 1807 1808 /* 1809 * This function does the following things: 1810 * 1811 * - detaches the PMC from hardware 1812 * - unlinks all target threads that were attached to it 1813 * - removes the PMC from its owner's list 1814 * - destroy's the PMC private mutex 1815 * 1816 * Once this function completes, the given pmc pointer can be safely 1817 * FREE'd by the caller. 1818 */ 1819 1820 static void 1821 pmc_release_pmc_descriptor(struct pmc *pm) 1822 { 1823 u_int ri, cpu; 1824 enum pmc_mode mode; 1825 struct pmc_hw *phw; 1826 struct pmc_owner *po; 1827 struct pmc_process *pp; 1828 struct pmc_target *ptgt, *tmp; 1829 struct pmc_binding pb; 1830 1831 sx_assert(&pmc_sx, SX_XLOCKED); 1832 1833 KASSERT(pm, ("[pmc,%d] null pmc", __LINE__)); 1834 1835 ri = PMC_TO_ROWINDEX(pm); 1836 mode = PMC_TO_MODE(pm); 1837 1838 PMCDBG(PMC,REL,1, "release-pmc pmc=%p ri=%d mode=%d", pm, ri, 1839 mode); 1840 1841 /* 1842 * First, we take the PMC off hardware. 1843 */ 1844 cpu = 0; 1845 if (PMC_IS_SYSTEM_MODE(mode)) { 1846 1847 /* 1848 * A system mode PMC runs on a specific CPU. Switch 1849 * to this CPU and turn hardware off. 1850 */ 1851 pmc_save_cpu_binding(&pb); 1852 1853 cpu = PMC_TO_CPU(pm); 1854 1855 pmc_select_cpu(cpu); 1856 1857 /* switch off non-stalled CPUs */ 1858 if (pm->pm_state == PMC_STATE_RUNNING && 1859 pm->pm_stalled == 0) { 1860 1861 phw = pmc_pcpu[cpu]->pc_hwpmcs[ri]; 1862 1863 KASSERT(phw->phw_pmc == pm, 1864 ("[pmc, %d] pmc ptr ri(%d) hw(%p) pm(%p)", 1865 __LINE__, ri, phw->phw_pmc, pm)); 1866 PMCDBG(PMC,REL,2, "stopping cpu=%d ri=%d", cpu, ri); 1867 1868 critical_enter(); 1869 md->pmd_stop_pmc(cpu, ri); 1870 critical_exit(); 1871 } 1872 1873 PMCDBG(PMC,REL,2, "decfg cpu=%d ri=%d", cpu, ri); 1874 1875 critical_enter(); 1876 md->pmd_config_pmc(cpu, ri, NULL); 1877 critical_exit(); 1878 1879 /* adjust the global and process count of SS mode PMCs */ 1880 if (mode == PMC_MODE_SS && pm->pm_state == PMC_STATE_RUNNING) { 1881 po = pm->pm_owner; 1882 po->po_sscount--; 1883 if (po->po_sscount == 0) { 1884 atomic_subtract_rel_int(&pmc_ss_count, 1); 1885 LIST_REMOVE(po, po_ssnext); 1886 } 1887 } 1888 1889 pm->pm_state = PMC_STATE_DELETED; 1890 1891 pmc_restore_cpu_binding(&pb); 1892 1893 /* 1894 * We could have references to this PMC structure in 1895 * the per-cpu sample queues. Wait for the queue to 1896 * drain. 1897 */ 1898 pmc_wait_for_pmc_idle(pm); 1899 1900 } else if (PMC_IS_VIRTUAL_MODE(mode)) { 1901 1902 /* 1903 * A virtual PMC could be running on multiple CPUs at 1904 * a given instant. 1905 * 1906 * By marking its state as DELETED, we ensure that 1907 * this PMC is never further scheduled on hardware. 1908 * 1909 * Then we wait till all CPUs are done with this PMC. 1910 */ 1911 pm->pm_state = PMC_STATE_DELETED; 1912 1913 1914 /* Wait for the PMCs runcount to come to zero. */ 1915 pmc_wait_for_pmc_idle(pm); 1916 1917 /* 1918 * At this point the PMC is off all CPUs and cannot be 1919 * freshly scheduled onto a CPU. It is now safe to 1920 * unlink all targets from this PMC. If a 1921 * process-record's refcount falls to zero, we remove 1922 * it from the hash table. The module-wide SX lock 1923 * protects us from races. 1924 */ 1925 LIST_FOREACH_SAFE(ptgt, &pm->pm_targets, pt_next, tmp) { 1926 pp = ptgt->pt_process; 1927 pmc_unlink_target_process(pm, pp); /* frees 'ptgt' */ 1928 1929 PMCDBG(PMC,REL,3, "pp->refcnt=%d", pp->pp_refcnt); 1930 1931 /* 1932 * If the target process record shows that no 1933 * PMCs are attached to it, reclaim its space. 1934 */ 1935 1936 if (pp->pp_refcnt == 0) { 1937 pmc_remove_process_descriptor(pp); 1938 FREE(pp, M_PMC); 1939 } 1940 } 1941 1942 cpu = curthread->td_oncpu; /* setup cpu for pmd_release() */ 1943 1944 } 1945 1946 /* 1947 * Release any MD resources 1948 */ 1949 1950 (void) md->pmd_release_pmc(cpu, ri, pm); 1951 1952 /* 1953 * Update row disposition 1954 */ 1955 1956 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) 1957 PMC_UNMARK_ROW_STANDALONE(ri); 1958 else 1959 PMC_UNMARK_ROW_THREAD(ri); 1960 1961 /* unlink from the owner's list */ 1962 if (pm->pm_owner) { 1963 LIST_REMOVE(pm, pm_next); 1964 pm->pm_owner = NULL; 1965 } 1966 1967 pmc_destroy_pmc_descriptor(pm); 1968 } 1969 1970 /* 1971 * Register an owner and a pmc. 1972 */ 1973 1974 static int 1975 pmc_register_owner(struct proc *p, struct pmc *pmc) 1976 { 1977 struct pmc_owner *po; 1978 1979 sx_assert(&pmc_sx, SX_XLOCKED); 1980 1981 if ((po = pmc_find_owner_descriptor(p)) == NULL) 1982 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) 1983 return ENOMEM; 1984 1985 KASSERT(pmc->pm_owner == NULL, 1986 ("[pmc,%d] attempting to own an initialized PMC", __LINE__)); 1987 pmc->pm_owner = po; 1988 1989 LIST_INSERT_HEAD(&po->po_pmcs, pmc, pm_next); 1990 1991 PROC_LOCK(p); 1992 p->p_flag |= P_HWPMC; 1993 PROC_UNLOCK(p); 1994 1995 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1996 pmclog_process_pmcallocate(pmc); 1997 1998 PMCDBG(PMC,REG,1, "register-owner pmc-owner=%p pmc=%p", 1999 po, pmc); 2000 2001 return 0; 2002 } 2003 2004 /* 2005 * Return the current row disposition: 2006 * == 0 => FREE 2007 * > 0 => PROCESS MODE 2008 * < 0 => SYSTEM MODE 2009 */ 2010 2011 int 2012 pmc_getrowdisp(int ri) 2013 { 2014 return pmc_pmcdisp[ri]; 2015 } 2016 2017 /* 2018 * Check if a PMC at row index 'ri' can be allocated to the current 2019 * process. 2020 * 2021 * Allocation can fail if: 2022 * - the current process is already being profiled by a PMC at index 'ri', 2023 * attached to it via OP_PMCATTACH. 2024 * - the current process has already allocated a PMC at index 'ri' 2025 * via OP_ALLOCATE. 2026 */ 2027 2028 static int 2029 pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, int cpu) 2030 { 2031 enum pmc_mode mode; 2032 struct pmc *pm; 2033 struct pmc_owner *po; 2034 struct pmc_process *pp; 2035 2036 PMCDBG(PMC,ALR,1, "can-allocate-rowindex proc=%p (%d, %s) ri=%d " 2037 "cpu=%d", p, p->p_pid, p->p_comm, ri, cpu); 2038 2039 /* 2040 * We shouldn't have already allocated a process-mode PMC at 2041 * row index 'ri'. 2042 * 2043 * We shouldn't have allocated a system-wide PMC on the same 2044 * CPU and same RI. 2045 */ 2046 if ((po = pmc_find_owner_descriptor(p)) != NULL) 2047 LIST_FOREACH(pm, &po->po_pmcs, pm_next) { 2048 if (PMC_TO_ROWINDEX(pm) == ri) { 2049 mode = PMC_TO_MODE(pm); 2050 if (PMC_IS_VIRTUAL_MODE(mode)) 2051 return EEXIST; 2052 if (PMC_IS_SYSTEM_MODE(mode) && 2053 (int) PMC_TO_CPU(pm) == cpu) 2054 return EEXIST; 2055 } 2056 } 2057 2058 /* 2059 * We also shouldn't be the target of any PMC at this index 2060 * since otherwise a PMC_ATTACH to ourselves will fail. 2061 */ 2062 if ((pp = pmc_find_process_descriptor(p, 0)) != NULL) 2063 if (pp->pp_pmcs[ri].pp_pmc) 2064 return EEXIST; 2065 2066 PMCDBG(PMC,ALR,2, "can-allocate-rowindex proc=%p (%d, %s) ri=%d ok", 2067 p, p->p_pid, p->p_comm, ri); 2068 2069 return 0; 2070 } 2071 2072 /* 2073 * Check if a given PMC at row index 'ri' can be currently used in 2074 * mode 'mode'. 2075 */ 2076 2077 static int 2078 pmc_can_allocate_row(int ri, enum pmc_mode mode) 2079 { 2080 enum pmc_disp disp; 2081 2082 sx_assert(&pmc_sx, SX_XLOCKED); 2083 2084 PMCDBG(PMC,ALR,1, "can-allocate-row ri=%d mode=%d", ri, mode); 2085 2086 if (PMC_IS_SYSTEM_MODE(mode)) 2087 disp = PMC_DISP_STANDALONE; 2088 else 2089 disp = PMC_DISP_THREAD; 2090 2091 /* 2092 * check disposition for PMC row 'ri': 2093 * 2094 * Expected disposition Row-disposition Result 2095 * 2096 * STANDALONE STANDALONE or FREE proceed 2097 * STANDALONE THREAD fail 2098 * THREAD THREAD or FREE proceed 2099 * THREAD STANDALONE fail 2100 */ 2101 2102 if (!PMC_ROW_DISP_IS_FREE(ri) && 2103 !(disp == PMC_DISP_THREAD && PMC_ROW_DISP_IS_THREAD(ri)) && 2104 !(disp == PMC_DISP_STANDALONE && PMC_ROW_DISP_IS_STANDALONE(ri))) 2105 return EBUSY; 2106 2107 /* 2108 * All OK 2109 */ 2110 2111 PMCDBG(PMC,ALR,2, "can-allocate-row ri=%d mode=%d ok", ri, mode); 2112 2113 return 0; 2114 2115 } 2116 2117 /* 2118 * Find a PMC descriptor with user handle 'pmcid' for thread 'td'. 2119 */ 2120 2121 static struct pmc * 2122 pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, pmc_id_t pmcid) 2123 { 2124 struct pmc *pm; 2125 2126 KASSERT(PMC_ID_TO_ROWINDEX(pmcid) < md->pmd_npmc, 2127 ("[pmc,%d] Illegal pmc index %d (max %d)", __LINE__, 2128 PMC_ID_TO_ROWINDEX(pmcid), md->pmd_npmc)); 2129 2130 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 2131 if (pm->pm_id == pmcid) 2132 return pm; 2133 2134 return NULL; 2135 } 2136 2137 static int 2138 pmc_find_pmc(pmc_id_t pmcid, struct pmc **pmc) 2139 { 2140 2141 struct pmc *pm; 2142 struct pmc_owner *po; 2143 2144 PMCDBG(PMC,FND,1, "find-pmc id=%d", pmcid); 2145 2146 if ((po = pmc_find_owner_descriptor(curthread->td_proc)) == NULL) 2147 return ESRCH; 2148 2149 if ((pm = pmc_find_pmc_descriptor_in_process(po, pmcid)) == NULL) 2150 return EINVAL; 2151 2152 PMCDBG(PMC,FND,2, "find-pmc id=%d -> pmc=%p", pmcid, pm); 2153 2154 *pmc = pm; 2155 return 0; 2156 } 2157 2158 /* 2159 * Start a PMC. 2160 */ 2161 2162 static int 2163 pmc_start(struct pmc *pm) 2164 { 2165 int error, cpu, ri; 2166 enum pmc_mode mode; 2167 struct pmc_owner *po; 2168 struct pmc_binding pb; 2169 2170 KASSERT(pm != NULL, 2171 ("[pmc,%d] null pm", __LINE__)); 2172 2173 mode = PMC_TO_MODE(pm); 2174 ri = PMC_TO_ROWINDEX(pm); 2175 error = 0; 2176 2177 PMCDBG(PMC,OPS,1, "start pmc=%p mode=%d ri=%d", pm, mode, ri); 2178 2179 po = pm->pm_owner; 2180 2181 if (PMC_IS_VIRTUAL_MODE(mode)) { 2182 2183 /* 2184 * If a PMCATTACH has never been done on this PMC, 2185 * attach it to its owner process. 2186 */ 2187 2188 if (LIST_EMPTY(&pm->pm_targets)) 2189 error = (pm->pm_flags & PMC_F_ATTACH_DONE) ? ESRCH : 2190 pmc_attach_process(po->po_owner, pm); 2191 2192 /* 2193 * Disallow PMCSTART if a logfile is required but has not 2194 * been configured yet. 2195 */ 2196 2197 if (error == 0 && (pm->pm_flags & PMC_F_NEEDS_LOGFILE) && 2198 (po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) 2199 error = EDOOFUS; 2200 2201 /* 2202 * If the PMC is attached to its owner, then force a context 2203 * switch to ensure that the MD state gets set correctly. 2204 */ 2205 2206 if (error == 0) { 2207 pm->pm_state = PMC_STATE_RUNNING; 2208 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) 2209 pmc_force_context_switch(); 2210 } 2211 2212 return error; 2213 } 2214 2215 2216 /* 2217 * A system-wide PMC. 2218 */ 2219 2220 if ((pm->pm_flags & PMC_F_NEEDS_LOGFILE) && 2221 (po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) 2222 return EDOOFUS; /* programming error */ 2223 2224 /* 2225 * Add the owner to the global list if this is a system-wide 2226 * sampling PMC. 2227 */ 2228 2229 if (mode == PMC_MODE_SS) { 2230 if (po->po_sscount == 0) { 2231 LIST_INSERT_HEAD(&pmc_ss_owners, po, po_ssnext); 2232 atomic_add_rel_int(&pmc_ss_count, 1); 2233 PMCDBG(PMC,OPS,1, "po=%p in global list", po); 2234 } 2235 po->po_sscount++; 2236 } 2237 2238 /* 2239 * Move to the CPU associated with this 2240 * PMC, and start the hardware. 2241 */ 2242 2243 pmc_save_cpu_binding(&pb); 2244 2245 cpu = PMC_TO_CPU(pm); 2246 2247 if (pmc_cpu_is_disabled(cpu)) 2248 return ENXIO; 2249 2250 pmc_select_cpu(cpu); 2251 2252 /* 2253 * global PMCs are configured at allocation time 2254 * so write out the initial value and start the PMC. 2255 */ 2256 2257 pm->pm_state = PMC_STATE_RUNNING; 2258 2259 critical_enter(); 2260 if ((error = md->pmd_write_pmc(cpu, ri, 2261 PMC_IS_SAMPLING_MODE(mode) ? 2262 pm->pm_sc.pm_reloadcount : 2263 pm->pm_sc.pm_initial)) == 0) 2264 error = md->pmd_start_pmc(cpu, ri); 2265 critical_exit(); 2266 2267 pmc_restore_cpu_binding(&pb); 2268 2269 return error; 2270 } 2271 2272 /* 2273 * Stop a PMC. 2274 */ 2275 2276 static int 2277 pmc_stop(struct pmc *pm) 2278 { 2279 int cpu, error, ri; 2280 struct pmc_owner *po; 2281 struct pmc_binding pb; 2282 2283 KASSERT(pm != NULL, ("[pmc,%d] null pmc", __LINE__)); 2284 2285 PMCDBG(PMC,OPS,1, "stop pmc=%p mode=%d ri=%d", pm, 2286 PMC_TO_MODE(pm), PMC_TO_ROWINDEX(pm)); 2287 2288 pm->pm_state = PMC_STATE_STOPPED; 2289 2290 /* 2291 * If the PMC is a virtual mode one, changing the state to 2292 * non-RUNNING is enough to ensure that the PMC never gets 2293 * scheduled. 2294 * 2295 * If this PMC is current running on a CPU, then it will 2296 * handled correctly at the time its target process is context 2297 * switched out. 2298 */ 2299 2300 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 2301 return 0; 2302 2303 /* 2304 * A system-mode PMC. Move to the CPU associated with 2305 * this PMC, and stop the hardware. We update the 2306 * 'initial count' so that a subsequent PMCSTART will 2307 * resume counting from the current hardware count. 2308 */ 2309 2310 pmc_save_cpu_binding(&pb); 2311 2312 cpu = PMC_TO_CPU(pm); 2313 2314 KASSERT(cpu >= 0 && cpu < mp_ncpus, 2315 ("[pmc,%d] illegal cpu=%d", __LINE__, cpu)); 2316 2317 if (pmc_cpu_is_disabled(cpu)) 2318 return ENXIO; 2319 2320 pmc_select_cpu(cpu); 2321 2322 ri = PMC_TO_ROWINDEX(pm); 2323 2324 critical_enter(); 2325 if ((error = md->pmd_stop_pmc(cpu, ri)) == 0) 2326 error = md->pmd_read_pmc(cpu, ri, &pm->pm_sc.pm_initial); 2327 critical_exit(); 2328 2329 pmc_restore_cpu_binding(&pb); 2330 2331 po = pm->pm_owner; 2332 2333 /* remove this owner from the global list of SS PMC owners */ 2334 if (PMC_TO_MODE(pm) == PMC_MODE_SS) { 2335 po->po_sscount--; 2336 if (po->po_sscount == 0) { 2337 atomic_subtract_rel_int(&pmc_ss_count, 1); 2338 LIST_REMOVE(po, po_ssnext); 2339 PMCDBG(PMC,OPS,2,"po=%p removed from global list", po); 2340 } 2341 } 2342 2343 return error; 2344 } 2345 2346 2347 #if DEBUG 2348 static const char *pmc_op_to_name[] = { 2349 #undef __PMC_OP 2350 #define __PMC_OP(N, D) #N , 2351 __PMC_OPS() 2352 NULL 2353 }; 2354 #endif 2355 2356 /* 2357 * The syscall interface 2358 */ 2359 2360 #define PMC_GET_SX_XLOCK(...) do { \ 2361 sx_xlock(&pmc_sx); \ 2362 if (pmc_hook == NULL) { \ 2363 sx_xunlock(&pmc_sx); \ 2364 return __VA_ARGS__; \ 2365 } \ 2366 } while (0) 2367 2368 #define PMC_DOWNGRADE_SX() do { \ 2369 sx_downgrade(&pmc_sx); \ 2370 is_sx_downgraded = 1; \ 2371 } while (0) 2372 2373 static int 2374 pmc_syscall_handler(struct thread *td, void *syscall_args) 2375 { 2376 int error, is_sx_downgraded, op; 2377 struct pmc_syscall_args *c; 2378 void *arg; 2379 2380 PMC_GET_SX_XLOCK(ENOSYS); 2381 2382 DROP_GIANT(); 2383 2384 is_sx_downgraded = 0; 2385 2386 c = (struct pmc_syscall_args *) syscall_args; 2387 2388 op = c->pmop_code; 2389 arg = c->pmop_data; 2390 2391 PMCDBG(MOD,PMS,1, "syscall op=%d \"%s\" arg=%p", op, 2392 pmc_op_to_name[op], arg); 2393 2394 error = 0; 2395 atomic_add_int(&pmc_stats.pm_syscalls, 1); 2396 2397 switch(op) 2398 { 2399 2400 2401 /* 2402 * Configure a log file. 2403 * 2404 * XXX This OP will be reworked. 2405 */ 2406 2407 case PMC_OP_CONFIGURELOG: 2408 { 2409 struct pmc_owner *po; 2410 struct pmc_op_configurelog cl; 2411 struct proc *p; 2412 2413 sx_assert(&pmc_sx, SX_XLOCKED); 2414 2415 if ((error = copyin(arg, &cl, sizeof(cl))) != 0) 2416 break; 2417 2418 /* mark this process as owning a log file */ 2419 p = td->td_proc; 2420 if ((po = pmc_find_owner_descriptor(p)) == NULL) 2421 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) { 2422 error = ENOMEM; 2423 break; 2424 } 2425 2426 /* 2427 * If a valid fd was passed in, try to configure that, 2428 * otherwise if 'fd' was less than zero and there was 2429 * a log file configured, flush its buffers and 2430 * de-configure it. 2431 */ 2432 if (cl.pm_logfd >= 0) 2433 error = pmclog_configure_log(po, cl.pm_logfd); 2434 else if (po->po_flags & PMC_PO_OWNS_LOGFILE) { 2435 pmclog_process_closelog(po); 2436 error = pmclog_flush(po); 2437 if (error == 0) 2438 error = pmclog_deconfigure_log(po); 2439 } else 2440 error = EINVAL; 2441 } 2442 break; 2443 2444 2445 /* 2446 * Flush a log file. 2447 */ 2448 2449 case PMC_OP_FLUSHLOG: 2450 { 2451 struct pmc_owner *po; 2452 2453 sx_assert(&pmc_sx, SX_XLOCKED); 2454 2455 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 2456 error = EINVAL; 2457 break; 2458 } 2459 2460 error = pmclog_flush(po); 2461 } 2462 break; 2463 2464 /* 2465 * Retrieve hardware configuration. 2466 */ 2467 2468 case PMC_OP_GETCPUINFO: /* CPU information */ 2469 { 2470 struct pmc_op_getcpuinfo gci; 2471 2472 gci.pm_cputype = md->pmd_cputype; 2473 gci.pm_ncpu = mp_ncpus; 2474 gci.pm_npmc = md->pmd_npmc; 2475 gci.pm_nclass = md->pmd_nclass; 2476 bcopy(md->pmd_classes, &gci.pm_classes, 2477 sizeof(gci.pm_classes)); 2478 error = copyout(&gci, arg, sizeof(gci)); 2479 } 2480 break; 2481 2482 2483 /* 2484 * Get module statistics 2485 */ 2486 2487 case PMC_OP_GETDRIVERSTATS: 2488 { 2489 struct pmc_op_getdriverstats gms; 2490 2491 bcopy(&pmc_stats, &gms, sizeof(gms)); 2492 error = copyout(&gms, arg, sizeof(gms)); 2493 } 2494 break; 2495 2496 2497 /* 2498 * Retrieve module version number 2499 */ 2500 2501 case PMC_OP_GETMODULEVERSION: 2502 { 2503 uint32_t cv, modv; 2504 2505 /* retrieve the client's idea of the ABI version */ 2506 if ((error = copyin(arg, &cv, sizeof(uint32_t))) != 0) 2507 break; 2508 /* don't service clients newer than our driver */ 2509 modv = PMC_VERSION; 2510 if ((cv & 0xFFFF0000) > (modv & 0xFFFF0000)) { 2511 error = EPROGMISMATCH; 2512 break; 2513 } 2514 error = copyout(&modv, arg, sizeof(int)); 2515 } 2516 break; 2517 2518 2519 /* 2520 * Retrieve the state of all the PMCs on a given 2521 * CPU. 2522 */ 2523 2524 case PMC_OP_GETPMCINFO: 2525 { 2526 uint32_t cpu, n, npmc; 2527 size_t pmcinfo_size; 2528 struct pmc *pm; 2529 struct pmc_info *p, *pmcinfo; 2530 struct pmc_op_getpmcinfo *gpi; 2531 struct pmc_owner *po; 2532 struct pmc_binding pb; 2533 2534 PMC_DOWNGRADE_SX(); 2535 2536 gpi = (struct pmc_op_getpmcinfo *) arg; 2537 2538 if ((error = copyin(&gpi->pm_cpu, &cpu, sizeof(cpu))) != 0) 2539 break; 2540 2541 if (cpu >= (unsigned int) mp_ncpus) { 2542 error = EINVAL; 2543 break; 2544 } 2545 2546 if (pmc_cpu_is_disabled(cpu)) { 2547 error = ENXIO; 2548 break; 2549 } 2550 2551 /* switch to CPU 'cpu' */ 2552 pmc_save_cpu_binding(&pb); 2553 pmc_select_cpu(cpu); 2554 2555 npmc = md->pmd_npmc; 2556 2557 pmcinfo_size = npmc * sizeof(struct pmc_info); 2558 MALLOC(pmcinfo, struct pmc_info *, pmcinfo_size, M_PMC, 2559 M_WAITOK); 2560 2561 p = pmcinfo; 2562 2563 for (n = 0; n < md->pmd_npmc; n++, p++) { 2564 2565 if ((error = md->pmd_describe(cpu, n, p, &pm)) != 0) 2566 break; 2567 2568 if (PMC_ROW_DISP_IS_STANDALONE(n)) 2569 p->pm_rowdisp = PMC_DISP_STANDALONE; 2570 else if (PMC_ROW_DISP_IS_THREAD(n)) 2571 p->pm_rowdisp = PMC_DISP_THREAD; 2572 else 2573 p->pm_rowdisp = PMC_DISP_FREE; 2574 2575 p->pm_ownerpid = -1; 2576 2577 if (pm == NULL) /* no PMC associated */ 2578 continue; 2579 2580 po = pm->pm_owner; 2581 2582 KASSERT(po->po_owner != NULL, 2583 ("[pmc,%d] pmc_owner had a null proc pointer", 2584 __LINE__)); 2585 2586 p->pm_ownerpid = po->po_owner->p_pid; 2587 p->pm_mode = PMC_TO_MODE(pm); 2588 p->pm_event = pm->pm_event; 2589 p->pm_flags = pm->pm_flags; 2590 2591 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 2592 p->pm_reloadcount = 2593 pm->pm_sc.pm_reloadcount; 2594 } 2595 2596 pmc_restore_cpu_binding(&pb); 2597 2598 /* now copy out the PMC info collected */ 2599 if (error == 0) 2600 error = copyout(pmcinfo, &gpi->pm_pmcs, pmcinfo_size); 2601 2602 FREE(pmcinfo, M_PMC); 2603 } 2604 break; 2605 2606 2607 /* 2608 * Set the administrative state of a PMC. I.e. whether 2609 * the PMC is to be used or not. 2610 */ 2611 2612 case PMC_OP_PMCADMIN: 2613 { 2614 int cpu, ri; 2615 enum pmc_state request; 2616 struct pmc_cpu *pc; 2617 struct pmc_hw *phw; 2618 struct pmc_op_pmcadmin pma; 2619 struct pmc_binding pb; 2620 2621 sx_assert(&pmc_sx, SX_XLOCKED); 2622 2623 KASSERT(td == curthread, 2624 ("[pmc,%d] td != curthread", __LINE__)); 2625 2626 if (suser(td) || jailed(td->td_ucred)) { 2627 error = EPERM; 2628 break; 2629 } 2630 2631 if ((error = copyin(arg, &pma, sizeof(pma))) != 0) 2632 break; 2633 2634 cpu = pma.pm_cpu; 2635 2636 if (cpu < 0 || cpu >= mp_ncpus) { 2637 error = EINVAL; 2638 break; 2639 } 2640 2641 if (pmc_cpu_is_disabled(cpu)) { 2642 error = ENXIO; 2643 break; 2644 } 2645 2646 request = pma.pm_state; 2647 2648 if (request != PMC_STATE_DISABLED && 2649 request != PMC_STATE_FREE) { 2650 error = EINVAL; 2651 break; 2652 } 2653 2654 ri = pma.pm_pmc; /* pmc id == row index */ 2655 if (ri < 0 || ri >= (int) md->pmd_npmc) { 2656 error = EINVAL; 2657 break; 2658 } 2659 2660 /* 2661 * We can't disable a PMC with a row-index allocated 2662 * for process virtual PMCs. 2663 */ 2664 2665 if (PMC_ROW_DISP_IS_THREAD(ri) && 2666 request == PMC_STATE_DISABLED) { 2667 error = EBUSY; 2668 break; 2669 } 2670 2671 /* 2672 * otherwise, this PMC on this CPU is either free or 2673 * in system-wide mode. 2674 */ 2675 2676 pmc_save_cpu_binding(&pb); 2677 pmc_select_cpu(cpu); 2678 2679 pc = pmc_pcpu[cpu]; 2680 phw = pc->pc_hwpmcs[ri]; 2681 2682 /* 2683 * XXX do we need some kind of 'forced' disable? 2684 */ 2685 2686 if (phw->phw_pmc == NULL) { 2687 if (request == PMC_STATE_DISABLED && 2688 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED)) { 2689 phw->phw_state &= ~PMC_PHW_FLAG_IS_ENABLED; 2690 PMC_MARK_ROW_STANDALONE(ri); 2691 } else if (request == PMC_STATE_FREE && 2692 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0) { 2693 phw->phw_state |= PMC_PHW_FLAG_IS_ENABLED; 2694 PMC_UNMARK_ROW_STANDALONE(ri); 2695 } 2696 /* other cases are a no-op */ 2697 } else 2698 error = EBUSY; 2699 2700 pmc_restore_cpu_binding(&pb); 2701 } 2702 break; 2703 2704 2705 /* 2706 * Allocate a PMC. 2707 */ 2708 2709 case PMC_OP_PMCALLOCATE: 2710 { 2711 uint32_t caps; 2712 u_int cpu; 2713 int n; 2714 enum pmc_mode mode; 2715 struct pmc *pmc; 2716 struct pmc_hw *phw; 2717 struct pmc_op_pmcallocate pa; 2718 struct pmc_binding pb; 2719 2720 if ((error = copyin(arg, &pa, sizeof(pa))) != 0) 2721 break; 2722 2723 caps = pa.pm_caps; 2724 mode = pa.pm_mode; 2725 cpu = pa.pm_cpu; 2726 2727 if ((mode != PMC_MODE_SS && mode != PMC_MODE_SC && 2728 mode != PMC_MODE_TS && mode != PMC_MODE_TC) || 2729 (cpu != (u_int) PMC_CPU_ANY && cpu >= (u_int) mp_ncpus)) { 2730 error = EINVAL; 2731 break; 2732 } 2733 2734 /* 2735 * Virtual PMCs should only ask for a default CPU. 2736 * System mode PMCs need to specify a non-default CPU. 2737 */ 2738 2739 if ((PMC_IS_VIRTUAL_MODE(mode) && cpu != (u_int) PMC_CPU_ANY) || 2740 (PMC_IS_SYSTEM_MODE(mode) && cpu == (u_int) PMC_CPU_ANY)) { 2741 error = EINVAL; 2742 break; 2743 } 2744 2745 /* 2746 * Check that a disabled CPU is not being asked for. 2747 */ 2748 2749 if (PMC_IS_SYSTEM_MODE(mode) && pmc_cpu_is_disabled(cpu)) { 2750 error = ENXIO; 2751 break; 2752 } 2753 2754 /* 2755 * Refuse an allocation for a system-wide PMC if this 2756 * process has been jailed, or if this process lacks 2757 * super-user credentials and the sysctl tunable 2758 * 'security.bsd.unprivileged_syspmcs' is zero. 2759 */ 2760 2761 if (PMC_IS_SYSTEM_MODE(mode)) { 2762 if (jailed(curthread->td_ucred)) 2763 error = EPERM; 2764 else if (suser(curthread) && 2765 (pmc_unprivileged_syspmcs == 0)) 2766 error = EPERM; 2767 } 2768 2769 if (error) 2770 break; 2771 2772 /* 2773 * Look for valid values for 'pm_flags' 2774 */ 2775 2776 if ((pa.pm_flags & ~(PMC_F_DESCENDANTS | PMC_F_LOG_PROCCSW | 2777 PMC_F_LOG_PROCEXIT)) != 0) { 2778 error = EINVAL; 2779 break; 2780 } 2781 2782 /* process logging options are not allowed for system PMCs */ 2783 if (PMC_IS_SYSTEM_MODE(mode) && (pa.pm_flags & 2784 (PMC_F_LOG_PROCCSW | PMC_F_LOG_PROCEXIT))) { 2785 error = EINVAL; 2786 break; 2787 } 2788 2789 /* 2790 * All sampling mode PMCs need to be able to interrupt the 2791 * CPU. 2792 */ 2793 if (PMC_IS_SAMPLING_MODE(mode)) 2794 caps |= PMC_CAP_INTERRUPT; 2795 2796 /* A valid class specifier should have been passed in. */ 2797 for (n = 0; n < md->pmd_nclass; n++) 2798 if (md->pmd_classes[n].pm_class == pa.pm_class) 2799 break; 2800 if (n == md->pmd_nclass) { 2801 error = EINVAL; 2802 break; 2803 } 2804 2805 /* The requested PMC capabilities should be feasible. */ 2806 if ((md->pmd_classes[n].pm_caps & caps) != caps) { 2807 error = EOPNOTSUPP; 2808 break; 2809 } 2810 2811 PMCDBG(PMC,ALL,2, "event=%d caps=0x%x mode=%d cpu=%d", 2812 pa.pm_ev, caps, mode, cpu); 2813 2814 pmc = pmc_allocate_pmc_descriptor(); 2815 pmc->pm_id = PMC_ID_MAKE_ID(cpu,pa.pm_mode,pa.pm_class, 2816 PMC_ID_INVALID); 2817 pmc->pm_event = pa.pm_ev; 2818 pmc->pm_state = PMC_STATE_FREE; 2819 pmc->pm_caps = caps; 2820 pmc->pm_flags = pa.pm_flags; 2821 2822 /* switch thread to CPU 'cpu' */ 2823 pmc_save_cpu_binding(&pb); 2824 2825 #define PMC_IS_SHAREABLE_PMC(cpu, n) \ 2826 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_state & \ 2827 PMC_PHW_FLAG_IS_SHAREABLE) 2828 #define PMC_IS_UNALLOCATED(cpu, n) \ 2829 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_pmc == NULL) 2830 2831 if (PMC_IS_SYSTEM_MODE(mode)) { 2832 pmc_select_cpu(cpu); 2833 for (n = 0; n < (int) md->pmd_npmc; n++) 2834 if (pmc_can_allocate_row(n, mode) == 0 && 2835 pmc_can_allocate_rowindex( 2836 curthread->td_proc, n, cpu) == 0 && 2837 (PMC_IS_UNALLOCATED(cpu, n) || 2838 PMC_IS_SHAREABLE_PMC(cpu, n)) && 2839 md->pmd_allocate_pmc(cpu, n, pmc, 2840 &pa) == 0) 2841 break; 2842 } else { 2843 /* Process virtual mode */ 2844 for (n = 0; n < (int) md->pmd_npmc; n++) { 2845 if (pmc_can_allocate_row(n, mode) == 0 && 2846 pmc_can_allocate_rowindex( 2847 curthread->td_proc, n, 2848 PMC_CPU_ANY) == 0 && 2849 md->pmd_allocate_pmc(curthread->td_oncpu, 2850 n, pmc, &pa) == 0) 2851 break; 2852 } 2853 } 2854 2855 #undef PMC_IS_UNALLOCATED 2856 #undef PMC_IS_SHAREABLE_PMC 2857 2858 pmc_restore_cpu_binding(&pb); 2859 2860 if (n == (int) md->pmd_npmc) { 2861 pmc_destroy_pmc_descriptor(pmc); 2862 FREE(pmc, M_PMC); 2863 pmc = NULL; 2864 error = EINVAL; 2865 break; 2866 } 2867 2868 /* Fill in the correct value in the ID field */ 2869 pmc->pm_id = PMC_ID_MAKE_ID(cpu,mode,pa.pm_class,n); 2870 2871 PMCDBG(PMC,ALL,2, "ev=%d class=%d mode=%d n=%d -> pmcid=%x", 2872 pmc->pm_event, pa.pm_class, mode, n, pmc->pm_id); 2873 2874 /* Process mode PMCs with logging enabled need log files */ 2875 if (pmc->pm_flags & (PMC_F_LOG_PROCEXIT | PMC_F_LOG_PROCCSW)) 2876 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 2877 2878 /* All system mode sampling PMCs require a log file */ 2879 if (PMC_IS_SAMPLING_MODE(mode) && PMC_IS_SYSTEM_MODE(mode)) 2880 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 2881 2882 /* 2883 * Configure global pmc's immediately 2884 */ 2885 2886 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pmc))) { 2887 2888 pmc_save_cpu_binding(&pb); 2889 pmc_select_cpu(cpu); 2890 2891 phw = pmc_pcpu[cpu]->pc_hwpmcs[n]; 2892 2893 if ((phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0 || 2894 (error = md->pmd_config_pmc(cpu, n, pmc)) != 0) { 2895 (void) md->pmd_release_pmc(cpu, n, pmc); 2896 pmc_destroy_pmc_descriptor(pmc); 2897 FREE(pmc, M_PMC); 2898 pmc = NULL; 2899 pmc_restore_cpu_binding(&pb); 2900 error = EPERM; 2901 break; 2902 } 2903 2904 pmc_restore_cpu_binding(&pb); 2905 } 2906 2907 pmc->pm_state = PMC_STATE_ALLOCATED; 2908 2909 /* 2910 * mark row disposition 2911 */ 2912 2913 if (PMC_IS_SYSTEM_MODE(mode)) 2914 PMC_MARK_ROW_STANDALONE(n); 2915 else 2916 PMC_MARK_ROW_THREAD(n); 2917 2918 /* 2919 * Register this PMC with the current thread as its owner. 2920 */ 2921 2922 if ((error = 2923 pmc_register_owner(curthread->td_proc, pmc)) != 0) { 2924 pmc_release_pmc_descriptor(pmc); 2925 FREE(pmc, M_PMC); 2926 pmc = NULL; 2927 break; 2928 } 2929 2930 /* 2931 * Return the allocated index. 2932 */ 2933 2934 pa.pm_pmcid = pmc->pm_id; 2935 2936 error = copyout(&pa, arg, sizeof(pa)); 2937 } 2938 break; 2939 2940 2941 /* 2942 * Attach a PMC to a process. 2943 */ 2944 2945 case PMC_OP_PMCATTACH: 2946 { 2947 struct pmc *pm; 2948 struct proc *p; 2949 struct pmc_op_pmcattach a; 2950 2951 sx_assert(&pmc_sx, SX_XLOCKED); 2952 2953 if ((error = copyin(arg, &a, sizeof(a))) != 0) 2954 break; 2955 2956 if (a.pm_pid < 0) { 2957 error = EINVAL; 2958 break; 2959 } else if (a.pm_pid == 0) 2960 a.pm_pid = td->td_proc->p_pid; 2961 2962 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 2963 break; 2964 2965 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) { 2966 error = EINVAL; 2967 break; 2968 } 2969 2970 /* PMCs may be (re)attached only when allocated or stopped */ 2971 if (pm->pm_state == PMC_STATE_RUNNING) { 2972 error = EBUSY; 2973 break; 2974 } else if (pm->pm_state != PMC_STATE_ALLOCATED && 2975 pm->pm_state != PMC_STATE_STOPPED) { 2976 error = EINVAL; 2977 break; 2978 } 2979 2980 /* lookup pid */ 2981 if ((p = pfind(a.pm_pid)) == NULL) { 2982 error = ESRCH; 2983 break; 2984 } 2985 2986 /* 2987 * Ignore processes that are working on exiting. 2988 */ 2989 if (p->p_flag & P_WEXIT) { 2990 error = ESRCH; 2991 PROC_UNLOCK(p); /* pfind() returns a locked process */ 2992 break; 2993 } 2994 2995 /* 2996 * we are allowed to attach a PMC to a process if 2997 * we can debug it. 2998 */ 2999 error = p_candebug(curthread, p); 3000 3001 PROC_UNLOCK(p); 3002 3003 if (error == 0) 3004 error = pmc_attach_process(p, pm); 3005 } 3006 break; 3007 3008 3009 /* 3010 * Detach an attached PMC from a process. 3011 */ 3012 3013 case PMC_OP_PMCDETACH: 3014 { 3015 struct pmc *pm; 3016 struct proc *p; 3017 struct pmc_op_pmcattach a; 3018 3019 if ((error = copyin(arg, &a, sizeof(a))) != 0) 3020 break; 3021 3022 if (a.pm_pid < 0) { 3023 error = EINVAL; 3024 break; 3025 } else if (a.pm_pid == 0) 3026 a.pm_pid = td->td_proc->p_pid; 3027 3028 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 3029 break; 3030 3031 if ((p = pfind(a.pm_pid)) == NULL) { 3032 error = ESRCH; 3033 break; 3034 } 3035 3036 /* 3037 * Treat processes that are in the process of exiting 3038 * as if they were not present. 3039 */ 3040 3041 if (p->p_flag & P_WEXIT) 3042 error = ESRCH; 3043 3044 PROC_UNLOCK(p); /* pfind() returns a locked process */ 3045 3046 if (error == 0) 3047 error = pmc_detach_process(p, pm); 3048 } 3049 break; 3050 3051 3052 /* 3053 * Retrieve the MSR number associated with the counter 3054 * 'pmc_id'. This allows processes to directly use RDPMC 3055 * instructions to read their PMCs, without the overhead of a 3056 * system call. 3057 */ 3058 3059 case PMC_OP_PMCGETMSR: 3060 { 3061 int ri; 3062 struct pmc *pm; 3063 struct pmc_target *pt; 3064 struct pmc_op_getmsr gm; 3065 3066 PMC_DOWNGRADE_SX(); 3067 3068 /* CPU has no 'GETMSR' support */ 3069 if (md->pmd_get_msr == NULL) { 3070 error = ENOSYS; 3071 break; 3072 } 3073 3074 if ((error = copyin(arg, &gm, sizeof(gm))) != 0) 3075 break; 3076 3077 if ((error = pmc_find_pmc(gm.pm_pmcid, &pm)) != 0) 3078 break; 3079 3080 /* 3081 * The allocated PMC has to be a process virtual PMC, 3082 * i.e., of type MODE_T[CS]. Global PMCs can only be 3083 * read using the PMCREAD operation since they may be 3084 * allocated on a different CPU than the one we could 3085 * be running on at the time of the RDPMC instruction. 3086 * 3087 * The GETMSR operation is not allowed for PMCs that 3088 * are inherited across processes. 3089 */ 3090 3091 if (!PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)) || 3092 (pm->pm_flags & PMC_F_DESCENDANTS)) { 3093 error = EINVAL; 3094 break; 3095 } 3096 3097 /* 3098 * It only makes sense to use a RDPMC (or its 3099 * equivalent instruction on non-x86 architectures) on 3100 * a process that has allocated and attached a PMC to 3101 * itself. Conversely the PMC is only allowed to have 3102 * one process attached to it -- its owner. 3103 */ 3104 3105 if ((pt = LIST_FIRST(&pm->pm_targets)) == NULL || 3106 LIST_NEXT(pt, pt_next) != NULL || 3107 pt->pt_process->pp_proc != pm->pm_owner->po_owner) { 3108 error = EINVAL; 3109 break; 3110 } 3111 3112 ri = PMC_TO_ROWINDEX(pm); 3113 3114 if ((error = (*md->pmd_get_msr)(ri, &gm.pm_msr)) < 0) 3115 break; 3116 3117 if ((error = copyout(&gm, arg, sizeof(gm))) < 0) 3118 break; 3119 3120 /* 3121 * Mark our process as using MSRs. Update machine 3122 * state using a forced context switch. 3123 */ 3124 3125 pt->pt_process->pp_flags |= PMC_PP_ENABLE_MSR_ACCESS; 3126 pmc_force_context_switch(); 3127 3128 } 3129 break; 3130 3131 /* 3132 * Release an allocated PMC 3133 */ 3134 3135 case PMC_OP_PMCRELEASE: 3136 { 3137 pmc_id_t pmcid; 3138 struct pmc *pm; 3139 struct pmc_owner *po; 3140 struct pmc_op_simple sp; 3141 3142 /* 3143 * Find PMC pointer for the named PMC. 3144 * 3145 * Use pmc_release_pmc_descriptor() to switch off the 3146 * PMC, remove all its target threads, and remove the 3147 * PMC from its owner's list. 3148 * 3149 * Remove the owner record if this is the last PMC 3150 * owned. 3151 * 3152 * Free up space. 3153 */ 3154 3155 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3156 break; 3157 3158 pmcid = sp.pm_pmcid; 3159 3160 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3161 break; 3162 3163 po = pm->pm_owner; 3164 pmc_release_pmc_descriptor(pm); 3165 pmc_maybe_remove_owner(po); 3166 3167 FREE(pm, M_PMC); 3168 } 3169 break; 3170 3171 3172 /* 3173 * Read and/or write a PMC. 3174 */ 3175 3176 case PMC_OP_PMCRW: 3177 { 3178 uint32_t cpu, ri; 3179 struct pmc *pm; 3180 struct pmc_op_pmcrw *pprw; 3181 struct pmc_op_pmcrw prw; 3182 struct pmc_binding pb; 3183 pmc_value_t oldvalue; 3184 3185 PMC_DOWNGRADE_SX(); 3186 3187 if ((error = copyin(arg, &prw, sizeof(prw))) != 0) 3188 break; 3189 3190 ri = 0; 3191 PMCDBG(PMC,OPS,1, "rw id=%d flags=0x%x", prw.pm_pmcid, 3192 prw.pm_flags); 3193 3194 /* must have at least one flag set */ 3195 if ((prw.pm_flags & (PMC_F_OLDVALUE|PMC_F_NEWVALUE)) == 0) { 3196 error = EINVAL; 3197 break; 3198 } 3199 3200 /* locate pmc descriptor */ 3201 if ((error = pmc_find_pmc(prw.pm_pmcid, &pm)) != 0) 3202 break; 3203 3204 /* Can't read a PMC that hasn't been started. */ 3205 if (pm->pm_state != PMC_STATE_ALLOCATED && 3206 pm->pm_state != PMC_STATE_STOPPED && 3207 pm->pm_state != PMC_STATE_RUNNING) { 3208 error = EINVAL; 3209 break; 3210 } 3211 3212 /* writing a new value is allowed only for 'STOPPED' pmcs */ 3213 if (pm->pm_state == PMC_STATE_RUNNING && 3214 (prw.pm_flags & PMC_F_NEWVALUE)) { 3215 error = EBUSY; 3216 break; 3217 } 3218 3219 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) { 3220 3221 /* 3222 * If this PMC is attached to its owner (i.e., 3223 * the process requesting this operation) and 3224 * is running, then attempt to get an 3225 * upto-date reading from hardware for a READ. 3226 * Writes are only allowed when the PMC is 3227 * stopped, so only update the saved value 3228 * field. 3229 * 3230 * If the PMC is not running, or is not 3231 * attached to its owner, read/write to the 3232 * savedvalue field. 3233 */ 3234 3235 ri = PMC_TO_ROWINDEX(pm); 3236 3237 mtx_pool_lock_spin(pmc_mtxpool, pm); 3238 cpu = curthread->td_oncpu; 3239 3240 if (prw.pm_flags & PMC_F_OLDVALUE) { 3241 if ((pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) && 3242 (pm->pm_state == PMC_STATE_RUNNING)) 3243 error = (*md->pmd_read_pmc)(cpu, ri, 3244 &oldvalue); 3245 else 3246 oldvalue = pm->pm_gv.pm_savedvalue; 3247 } 3248 if (prw.pm_flags & PMC_F_NEWVALUE) 3249 pm->pm_gv.pm_savedvalue = prw.pm_value; 3250 3251 mtx_pool_unlock_spin(pmc_mtxpool, pm); 3252 3253 } else { /* System mode PMCs */ 3254 cpu = PMC_TO_CPU(pm); 3255 ri = PMC_TO_ROWINDEX(pm); 3256 3257 if (pmc_cpu_is_disabled(cpu)) { 3258 error = ENXIO; 3259 break; 3260 } 3261 3262 /* move this thread to CPU 'cpu' */ 3263 pmc_save_cpu_binding(&pb); 3264 pmc_select_cpu(cpu); 3265 3266 critical_enter(); 3267 /* save old value */ 3268 if (prw.pm_flags & PMC_F_OLDVALUE) 3269 if ((error = (*md->pmd_read_pmc)(cpu, ri, 3270 &oldvalue))) 3271 goto error; 3272 /* write out new value */ 3273 if (prw.pm_flags & PMC_F_NEWVALUE) 3274 error = (*md->pmd_write_pmc)(cpu, ri, 3275 prw.pm_value); 3276 error: 3277 critical_exit(); 3278 pmc_restore_cpu_binding(&pb); 3279 if (error) 3280 break; 3281 } 3282 3283 pprw = (struct pmc_op_pmcrw *) arg; 3284 3285 #if DEBUG 3286 if (prw.pm_flags & PMC_F_NEWVALUE) 3287 PMCDBG(PMC,OPS,2, "rw id=%d new %jx -> old %jx", 3288 ri, prw.pm_value, oldvalue); 3289 else 3290 PMCDBG(PMC,OPS,2, "rw id=%d -> old %jx", ri, oldvalue); 3291 #endif 3292 3293 /* return old value if requested */ 3294 if (prw.pm_flags & PMC_F_OLDVALUE) 3295 if ((error = copyout(&oldvalue, &pprw->pm_value, 3296 sizeof(prw.pm_value)))) 3297 break; 3298 3299 } 3300 break; 3301 3302 3303 /* 3304 * Set the sampling rate for a sampling mode PMC and the 3305 * initial count for a counting mode PMC. 3306 */ 3307 3308 case PMC_OP_PMCSETCOUNT: 3309 { 3310 struct pmc *pm; 3311 struct pmc_op_pmcsetcount sc; 3312 3313 PMC_DOWNGRADE_SX(); 3314 3315 if ((error = copyin(arg, &sc, sizeof(sc))) != 0) 3316 break; 3317 3318 if ((error = pmc_find_pmc(sc.pm_pmcid, &pm)) != 0) 3319 break; 3320 3321 if (pm->pm_state == PMC_STATE_RUNNING) { 3322 error = EBUSY; 3323 break; 3324 } 3325 3326 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 3327 pm->pm_sc.pm_reloadcount = sc.pm_count; 3328 else 3329 pm->pm_sc.pm_initial = sc.pm_count; 3330 } 3331 break; 3332 3333 3334 /* 3335 * Start a PMC. 3336 */ 3337 3338 case PMC_OP_PMCSTART: 3339 { 3340 pmc_id_t pmcid; 3341 struct pmc *pm; 3342 struct pmc_op_simple sp; 3343 3344 sx_assert(&pmc_sx, SX_XLOCKED); 3345 3346 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3347 break; 3348 3349 pmcid = sp.pm_pmcid; 3350 3351 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3352 break; 3353 3354 KASSERT(pmcid == pm->pm_id, 3355 ("[pmc,%d] pmcid %x != id %x", __LINE__, 3356 pm->pm_id, pmcid)); 3357 3358 if (pm->pm_state == PMC_STATE_RUNNING) /* already running */ 3359 break; 3360 else if (pm->pm_state != PMC_STATE_STOPPED && 3361 pm->pm_state != PMC_STATE_ALLOCATED) { 3362 error = EINVAL; 3363 break; 3364 } 3365 3366 error = pmc_start(pm); 3367 } 3368 break; 3369 3370 3371 /* 3372 * Stop a PMC. 3373 */ 3374 3375 case PMC_OP_PMCSTOP: 3376 { 3377 pmc_id_t pmcid; 3378 struct pmc *pm; 3379 struct pmc_op_simple sp; 3380 3381 PMC_DOWNGRADE_SX(); 3382 3383 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3384 break; 3385 3386 pmcid = sp.pm_pmcid; 3387 3388 /* 3389 * Mark the PMC as inactive and invoke the MD stop 3390 * routines if needed. 3391 */ 3392 3393 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3394 break; 3395 3396 KASSERT(pmcid == pm->pm_id, 3397 ("[pmc,%d] pmc id %x != pmcid %x", __LINE__, 3398 pm->pm_id, pmcid)); 3399 3400 if (pm->pm_state == PMC_STATE_STOPPED) /* already stopped */ 3401 break; 3402 else if (pm->pm_state != PMC_STATE_RUNNING) { 3403 error = EINVAL; 3404 break; 3405 } 3406 3407 error = pmc_stop(pm); 3408 } 3409 break; 3410 3411 3412 /* 3413 * Write a user supplied value to the log file. 3414 */ 3415 3416 case PMC_OP_WRITELOG: 3417 { 3418 struct pmc_op_writelog wl; 3419 struct pmc_owner *po; 3420 3421 PMC_DOWNGRADE_SX(); 3422 3423 if ((error = copyin(arg, &wl, sizeof(wl))) != 0) 3424 break; 3425 3426 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 3427 error = EINVAL; 3428 break; 3429 } 3430 3431 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) { 3432 error = EINVAL; 3433 break; 3434 } 3435 3436 error = pmclog_process_userlog(po, &wl); 3437 } 3438 break; 3439 3440 3441 default: 3442 error = EINVAL; 3443 break; 3444 } 3445 3446 if (is_sx_downgraded) 3447 sx_sunlock(&pmc_sx); 3448 else 3449 sx_xunlock(&pmc_sx); 3450 3451 if (error) 3452 atomic_add_int(&pmc_stats.pm_syscall_errors, 1); 3453 3454 PICKUP_GIANT(); 3455 3456 return error; 3457 } 3458 3459 /* 3460 * Helper functions 3461 */ 3462 3463 3464 /* 3465 * Interrupt processing. 3466 * 3467 * Find a free slot in the per-cpu array of PC samples and write the 3468 * current (PMC,PID,PC) triple to it. If an event was successfully 3469 * added, a bit is set in mask 'pmc_cpumask' denoting that the 3470 * DO_SAMPLES hook needs to be invoked from the clock handler. 3471 * 3472 * This function is meant to be called from an NMI handler. It cannot 3473 * use any of the locking primitives supplied by the OS. 3474 */ 3475 3476 int 3477 pmc_process_interrupt(int cpu, struct pmc *pm, uintfptr_t pc, int usermode) 3478 { 3479 int error, ri; 3480 struct thread *td; 3481 struct pmc_sample *ps; 3482 struct pmc_samplebuffer *psb; 3483 3484 error = 0; 3485 ri = PMC_TO_ROWINDEX(pm); 3486 3487 psb = pmc_pcpu[cpu]->pc_sb; 3488 3489 ps = psb->ps_write; 3490 if (ps->ps_pc) { /* in use, reader hasn't caught up */ 3491 pm->pm_stalled = 1; 3492 atomic_add_int(&pmc_stats.pm_intr_bufferfull, 1); 3493 PMCDBG(SAM,INT,1,"(spc) cpu=%d pm=%p pc=%jx um=%d wr=%d rd=%d", 3494 cpu, pm, (uint64_t) pc, usermode, 3495 (int) (psb->ps_write - psb->ps_samples), 3496 (int) (psb->ps_read - psb->ps_samples)); 3497 error = ENOMEM; 3498 goto done; 3499 } 3500 3501 /* fill in entry */ 3502 PMCDBG(SAM,INT,1,"cpu=%d pm=%p pc=%jx um=%d wr=%d rd=%d", cpu, pm, 3503 (uint64_t) pc, usermode, 3504 (int) (psb->ps_write - psb->ps_samples), 3505 (int) (psb->ps_read - psb->ps_samples)); 3506 3507 atomic_add_rel_32(&pm->pm_runcount, 1); /* hold onto PMC */ 3508 ps->ps_pmc = pm; 3509 if ((td = curthread) && td->td_proc) 3510 ps->ps_pid = td->td_proc->p_pid; 3511 else 3512 ps->ps_pid = -1; 3513 ps->ps_usermode = usermode; 3514 ps->ps_pc = pc; /* mark entry as in use */ 3515 3516 /* increment write pointer, modulo ring buffer size */ 3517 ps++; 3518 if (ps == psb->ps_fence) 3519 psb->ps_write = psb->ps_samples; 3520 else 3521 psb->ps_write = ps; 3522 3523 done: 3524 /* mark CPU as needing processing */ 3525 atomic_set_rel_int(&pmc_cpumask, (1 << cpu)); 3526 3527 return error; 3528 } 3529 3530 3531 /* 3532 * Process saved PC samples. 3533 */ 3534 3535 static void 3536 pmc_process_samples(int cpu) 3537 { 3538 int n, ri; 3539 struct pmc *pm; 3540 struct thread *td; 3541 struct pmc_owner *po; 3542 struct pmc_sample *ps; 3543 struct pmc_samplebuffer *psb; 3544 3545 KASSERT(PCPU_GET(cpuid) == cpu, 3546 ("[pmc,%d] not on the correct CPU pcpu=%d cpu=%d", __LINE__, 3547 PCPU_GET(cpuid), cpu)); 3548 3549 psb = pmc_pcpu[cpu]->pc_sb; 3550 3551 for (n = 0; n < pmc_nsamples; n++) { /* bound on #iterations */ 3552 3553 ps = psb->ps_read; 3554 if (ps->ps_pc == (uintfptr_t) 0) /* no data */ 3555 break; 3556 3557 pm = ps->ps_pmc; 3558 po = pm->pm_owner; 3559 3560 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 3561 ("[pmc,%d] pmc=%p non-sampling mode=%d", __LINE__, 3562 pm, PMC_TO_MODE(pm))); 3563 3564 /* Ignore PMCs that have been switched off */ 3565 if (pm->pm_state != PMC_STATE_RUNNING) 3566 goto entrydone; 3567 3568 PMCDBG(SAM,OPS,1,"cpu=%d pm=%p pc=%jx um=%d wr=%d rd=%d", cpu, 3569 pm, (uint64_t) ps->ps_pc, ps->ps_usermode, 3570 (int) (psb->ps_write - psb->ps_samples), 3571 (int) (psb->ps_read - psb->ps_samples)); 3572 3573 /* 3574 * If this is a process-mode PMC that is attached to 3575 * its owner, and if the PC is in user mode, update 3576 * profiling statistics like timer-based profiling 3577 * would have done. 3578 */ 3579 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) { 3580 if (ps->ps_usermode) { 3581 td = FIRST_THREAD_IN_PROC(po->po_owner); 3582 addupc_intr(td, ps->ps_pc, 1); 3583 } 3584 goto entrydone; 3585 } 3586 3587 /* 3588 * Otherwise, this is either a sampling mode PMC that 3589 * is attached to a different process than its owner, 3590 * or a system-wide sampling PMC. Dispatch a log 3591 * entry to the PMC's owner process. 3592 */ 3593 3594 pmclog_process_pcsample(pm, ps); 3595 3596 entrydone: 3597 ps->ps_pc = (uintfptr_t) 0; /* mark entry as free */ 3598 atomic_subtract_rel_32(&pm->pm_runcount, 1); 3599 3600 /* increment read pointer, modulo sample size */ 3601 if (++ps == psb->ps_fence) 3602 psb->ps_read = psb->ps_samples; 3603 else 3604 psb->ps_read = ps; 3605 } 3606 3607 atomic_add_int(&pmc_stats.pm_log_sweeps, 1); 3608 3609 /* Do not re-enable stalled PMCs if we failed to process any samples */ 3610 if (n == 0) 3611 return; 3612 3613 /* 3614 * Restart any stalled sampling PMCs on this CPU. 3615 * 3616 * If the NMI handler sets the pm_stalled field of a PMC after 3617 * the check below, we'll end up processing the stalled PMC at 3618 * the next hardclock tick. 3619 */ 3620 for (n = 0; n < md->pmd_npmc; n++) { 3621 (void) (*md->pmd_get_config)(cpu,n,&pm); 3622 if (pm == NULL || /* !cfg'ed */ 3623 pm->pm_state != PMC_STATE_RUNNING || /* !active */ 3624 !PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) || /* !sampling */ 3625 pm->pm_stalled == 0) /* !stalled */ 3626 continue; 3627 3628 pm->pm_stalled = 0; 3629 ri = PMC_TO_ROWINDEX(pm); 3630 (*md->pmd_start_pmc)(cpu, ri); 3631 } 3632 } 3633 3634 /* 3635 * Event handlers. 3636 */ 3637 3638 /* 3639 * Handle a process exit. 3640 * 3641 * Remove this process from all hash tables. If this process 3642 * owned any PMCs, turn off those PMCs and deallocate them, 3643 * removing any associations with target processes. 3644 * 3645 * This function will be called by the last 'thread' of a 3646 * process. 3647 * 3648 * XXX This eventhandler gets called early in the exit process. 3649 * Consider using a 'hook' invocation from thread_exit() or equivalent 3650 * spot. Another negative is that kse_exit doesn't seem to call 3651 * exit1() [??]. 3652 * 3653 */ 3654 3655 static void 3656 pmc_process_exit(void *arg __unused, struct proc *p) 3657 { 3658 int is_using_hwpmcs; 3659 int cpu; 3660 unsigned int ri; 3661 struct pmc *pm; 3662 struct pmc_process *pp; 3663 struct pmc_owner *po; 3664 pmc_value_t newvalue, tmp; 3665 3666 PROC_LOCK(p); 3667 is_using_hwpmcs = p->p_flag & P_HWPMC; 3668 PROC_UNLOCK(p); 3669 3670 /* 3671 * Log a sysexit event to all SS PMC owners. 3672 */ 3673 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 3674 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 3675 pmclog_process_sysexit(po, p->p_pid); 3676 3677 if (!is_using_hwpmcs) 3678 return; 3679 3680 PMC_GET_SX_XLOCK(); 3681 PMCDBG(PRC,EXT,1,"process-exit proc=%p (%d, %s)", p, p->p_pid, 3682 p->p_comm); 3683 3684 /* 3685 * Since this code is invoked by the last thread in an exiting 3686 * process, we would have context switched IN at some prior 3687 * point. However, with PREEMPTION, kernel mode context 3688 * switches may happen any time, so we want to disable a 3689 * context switch OUT till we get any PMCs targetting this 3690 * process off the hardware. 3691 * 3692 * We also need to atomically remove this process' 3693 * entry from our target process hash table, using 3694 * PMC_FLAG_REMOVE. 3695 */ 3696 PMCDBG(PRC,EXT,1, "process-exit proc=%p (%d, %s)", p, p->p_pid, 3697 p->p_comm); 3698 3699 critical_enter(); /* no preemption */ 3700 3701 cpu = curthread->td_oncpu; 3702 3703 if ((pp = pmc_find_process_descriptor(p, 3704 PMC_FLAG_REMOVE)) != NULL) { 3705 3706 PMCDBG(PRC,EXT,2, 3707 "process-exit proc=%p pmc-process=%p", p, pp); 3708 3709 /* 3710 * The exiting process could the target of 3711 * some PMCs which will be running on 3712 * currently executing CPU. 3713 * 3714 * We need to turn these PMCs off like we 3715 * would do at context switch OUT time. 3716 */ 3717 for (ri = 0; ri < md->pmd_npmc; ri++) { 3718 3719 /* 3720 * Pick up the pmc pointer from hardware 3721 * state similar to the CSW_OUT code. 3722 */ 3723 pm = NULL; 3724 (void) (*md->pmd_get_config)(cpu, ri, &pm); 3725 3726 PMCDBG(PRC,EXT,2, "ri=%d pm=%p", ri, pm); 3727 3728 if (pm == NULL || 3729 !PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 3730 continue; 3731 3732 PMCDBG(PRC,EXT,2, "ppmcs[%d]=%p pm=%p " 3733 "state=%d", ri, pp->pp_pmcs[ri].pp_pmc, 3734 pm, pm->pm_state); 3735 3736 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 3737 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 3738 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 3739 3740 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 3741 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", 3742 __LINE__, pm, ri, pp->pp_pmcs[ri].pp_pmc)); 3743 3744 (void) md->pmd_stop_pmc(cpu, ri); 3745 3746 KASSERT(pm->pm_runcount > 0, 3747 ("[pmc,%d] bad runcount ri %d rc %d", 3748 __LINE__, ri, pm->pm_runcount)); 3749 3750 /* Stop hardware only if it is actually running */ 3751 if (pm->pm_state == PMC_STATE_RUNNING && 3752 pm->pm_stalled == 0) { 3753 md->pmd_read_pmc(cpu, ri, &newvalue); 3754 tmp = newvalue - 3755 PMC_PCPU_SAVED(cpu,ri); 3756 3757 mtx_pool_lock_spin(pmc_mtxpool, pm); 3758 pm->pm_gv.pm_savedvalue += tmp; 3759 pp->pp_pmcs[ri].pp_pmcval += tmp; 3760 mtx_pool_unlock_spin(pmc_mtxpool, pm); 3761 } 3762 3763 atomic_subtract_rel_32(&pm->pm_runcount,1); 3764 3765 KASSERT((int) pm->pm_runcount >= 0, 3766 ("[pmc,%d] runcount is %d", __LINE__, ri)); 3767 3768 (void) md->pmd_config_pmc(cpu, ri, NULL); 3769 } 3770 3771 /* 3772 * Inform the MD layer of this pseudo "context switch 3773 * out" 3774 */ 3775 (void) md->pmd_switch_out(pmc_pcpu[cpu], pp); 3776 3777 critical_exit(); /* ok to be pre-empted now */ 3778 3779 /* 3780 * Unlink this process from the PMCs that are 3781 * targetting it. This will send a signal to 3782 * all PMC owner's whose PMCs are orphaned. 3783 * 3784 * Log PMC value at exit time if requested. 3785 */ 3786 for (ri = 0; ri < md->pmd_npmc; ri++) 3787 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 3788 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 3789 PMC_IS_COUNTING_MODE(PMC_TO_MODE(pm))) 3790 pmclog_process_procexit(pm, pp); 3791 pmc_unlink_target_process(pm, pp); 3792 } 3793 FREE(pp, M_PMC); 3794 3795 } else 3796 critical_exit(); /* pp == NULL */ 3797 3798 3799 /* 3800 * If the process owned PMCs, free them up and free up 3801 * memory. 3802 */ 3803 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 3804 pmc_remove_owner(po); 3805 pmc_destroy_owner_descriptor(po); 3806 } 3807 3808 sx_xunlock(&pmc_sx); 3809 } 3810 3811 /* 3812 * Handle a process fork. 3813 * 3814 * If the parent process 'p1' is under HWPMC monitoring, then copy 3815 * over any attached PMCs that have 'do_descendants' semantics. 3816 */ 3817 3818 static void 3819 pmc_process_fork(void *arg __unused, struct proc *p1, struct proc *newproc, 3820 int flags) 3821 { 3822 int is_using_hwpmcs; 3823 unsigned int ri; 3824 uint32_t do_descendants; 3825 struct pmc *pm; 3826 struct pmc_owner *po; 3827 struct pmc_process *ppnew, *ppold; 3828 3829 (void) flags; /* unused parameter */ 3830 3831 PROC_LOCK(p1); 3832 is_using_hwpmcs = p1->p_flag & P_HWPMC; 3833 PROC_UNLOCK(p1); 3834 3835 /* 3836 * If there are system-wide sampling PMCs active, we need to 3837 * log all fork events to their owner's logs. 3838 */ 3839 3840 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 3841 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 3842 pmclog_process_procfork(po, p1->p_pid, newproc->p_pid); 3843 3844 if (!is_using_hwpmcs) 3845 return; 3846 3847 PMC_GET_SX_XLOCK(); 3848 PMCDBG(PMC,FRK,1, "process-fork proc=%p (%d, %s) -> %p", p1, 3849 p1->p_pid, p1->p_comm, newproc); 3850 3851 /* 3852 * If the parent process (curthread->td_proc) is a 3853 * target of any PMCs, look for PMCs that are to be 3854 * inherited, and link these into the new process 3855 * descriptor. 3856 */ 3857 if ((ppold = pmc_find_process_descriptor(curthread->td_proc, 3858 PMC_FLAG_NONE)) == NULL) 3859 goto done; /* nothing to do */ 3860 3861 do_descendants = 0; 3862 for (ri = 0; ri < md->pmd_npmc; ri++) 3863 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL) 3864 do_descendants |= pm->pm_flags & PMC_F_DESCENDANTS; 3865 if (do_descendants == 0) /* nothing to do */ 3866 goto done; 3867 3868 /* allocate a descriptor for the new process */ 3869 if ((ppnew = pmc_find_process_descriptor(newproc, 3870 PMC_FLAG_ALLOCATE)) == NULL) 3871 goto done; 3872 3873 /* 3874 * Run through all PMCs that were targeting the old process 3875 * and which specified F_DESCENDANTS and attach them to the 3876 * new process. 3877 * 3878 * Log the fork event to all owners of PMCs attached to this 3879 * process, if not already logged. 3880 */ 3881 for (ri = 0; ri < md->pmd_npmc; ri++) 3882 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL && 3883 (pm->pm_flags & PMC_F_DESCENDANTS)) { 3884 pmc_link_target_process(pm, ppnew); 3885 po = pm->pm_owner; 3886 if (po->po_sscount == 0 && 3887 po->po_flags & PMC_PO_OWNS_LOGFILE) 3888 pmclog_process_procfork(po, p1->p_pid, 3889 newproc->p_pid); 3890 } 3891 3892 /* 3893 * Now mark the new process as being tracked by this driver. 3894 */ 3895 PROC_LOCK(newproc); 3896 newproc->p_flag |= P_HWPMC; 3897 PROC_UNLOCK(newproc); 3898 3899 done: 3900 sx_xunlock(&pmc_sx); 3901 } 3902 3903 3904 /* 3905 * initialization 3906 */ 3907 3908 static const char *pmc_name_of_pmcclass[] = { 3909 #undef __PMC_CLASS 3910 #define __PMC_CLASS(N) #N , 3911 __PMC_CLASSES() 3912 }; 3913 3914 static int 3915 pmc_initialize(void) 3916 { 3917 int cpu, error, n; 3918 struct pmc_binding pb; 3919 struct pmc_samplebuffer *sb; 3920 3921 md = NULL; 3922 error = 0; 3923 3924 #if DEBUG 3925 /* parse debug flags first */ 3926 if (TUNABLE_STR_FETCH(PMC_SYSCTL_NAME_PREFIX "debugflags", 3927 pmc_debugstr, sizeof(pmc_debugstr))) 3928 pmc_debugflags_parse(pmc_debugstr, 3929 pmc_debugstr+strlen(pmc_debugstr)); 3930 #endif 3931 3932 PMCDBG(MOD,INI,0, "PMC Initialize (version %x)", PMC_VERSION); 3933 3934 /* check kernel version */ 3935 if (pmc_kernel_version != PMC_VERSION) { 3936 if (pmc_kernel_version == 0) 3937 printf("hwpmc: this kernel has not been compiled with " 3938 "'options HWPMC_HOOKS'.\n"); 3939 else 3940 printf("hwpmc: kernel version (0x%x) does not match " 3941 "module version (0x%x).\n", pmc_kernel_version, 3942 PMC_VERSION); 3943 return EPROGMISMATCH; 3944 } 3945 3946 /* 3947 * check sysctl parameters 3948 */ 3949 3950 if (pmc_hashsize <= 0) { 3951 (void) printf("hwpmc: tunable hashsize=%d must be greater " 3952 "than zero.\n", pmc_hashsize); 3953 pmc_hashsize = PMC_HASH_SIZE; 3954 } 3955 3956 if (pmc_nsamples <= 0 || pmc_nsamples > 65535) { 3957 (void) printf("hwpmc: tunable nsamples=%d out of range.\n", pmc_nsamples); 3958 pmc_nsamples = PMC_NSAMPLES; 3959 } 3960 3961 md = pmc_md_initialize(); 3962 3963 if (md == NULL || md->pmd_init == NULL) 3964 return ENOSYS; 3965 3966 /* allocate space for the per-cpu array */ 3967 MALLOC(pmc_pcpu, struct pmc_cpu **, mp_ncpus * sizeof(struct pmc_cpu *), 3968 M_PMC, M_WAITOK|M_ZERO); 3969 3970 /* per-cpu 'saved values' for managing process-mode PMCs */ 3971 MALLOC(pmc_pcpu_saved, pmc_value_t *, 3972 sizeof(pmc_value_t) * mp_ncpus * md->pmd_npmc, M_PMC, M_WAITOK); 3973 3974 /* perform cpu dependent initialization */ 3975 pmc_save_cpu_binding(&pb); 3976 for (cpu = 0; cpu < mp_ncpus; cpu++) { 3977 if (pmc_cpu_is_disabled(cpu)) 3978 continue; 3979 pmc_select_cpu(cpu); 3980 if ((error = md->pmd_init(cpu)) != 0) 3981 break; 3982 } 3983 pmc_restore_cpu_binding(&pb); 3984 3985 if (error != 0) 3986 return error; 3987 3988 /* allocate space for the sample array */ 3989 for (cpu = 0; cpu < mp_ncpus; cpu++) { 3990 if (pmc_cpu_is_disabled(cpu)) 3991 continue; 3992 MALLOC(sb, struct pmc_samplebuffer *, 3993 sizeof(struct pmc_samplebuffer) + 3994 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 3995 M_WAITOK|M_ZERO); 3996 3997 sb->ps_read = sb->ps_write = sb->ps_samples; 3998 sb->ps_fence = sb->ps_samples + pmc_nsamples 3999 ; 4000 KASSERT(pmc_pcpu[cpu] != NULL, 4001 ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu)); 4002 4003 pmc_pcpu[cpu]->pc_sb = sb; 4004 } 4005 4006 /* allocate space for the row disposition array */ 4007 pmc_pmcdisp = malloc(sizeof(enum pmc_mode) * md->pmd_npmc, 4008 M_PMC, M_WAITOK|M_ZERO); 4009 4010 KASSERT(pmc_pmcdisp != NULL, 4011 ("[pmc,%d] pmcdisp allocation returned NULL", __LINE__)); 4012 4013 /* mark all PMCs as available */ 4014 for (n = 0; n < (int) md->pmd_npmc; n++) 4015 PMC_MARK_ROW_FREE(n); 4016 4017 /* allocate thread hash tables */ 4018 pmc_ownerhash = hashinit(pmc_hashsize, M_PMC, 4019 &pmc_ownerhashmask); 4020 4021 pmc_processhash = hashinit(pmc_hashsize, M_PMC, 4022 &pmc_processhashmask); 4023 mtx_init(&pmc_processhash_mtx, "pmc-process-hash", "pmc", MTX_SPIN); 4024 4025 LIST_INIT(&pmc_ss_owners); 4026 pmc_ss_count = 0; 4027 4028 /* allocate a pool of spin mutexes */ 4029 pmc_mtxpool = mtx_pool_create("pmc", pmc_mtxpool_size, MTX_SPIN); 4030 4031 PMCDBG(MOD,INI,1, "pmc_ownerhash=%p, mask=0x%lx " 4032 "targethash=%p mask=0x%lx", pmc_ownerhash, pmc_ownerhashmask, 4033 pmc_processhash, pmc_processhashmask); 4034 4035 /* register process {exit,fork,exec} handlers */ 4036 pmc_exit_tag = EVENTHANDLER_REGISTER(process_exit, 4037 pmc_process_exit, NULL, EVENTHANDLER_PRI_ANY); 4038 pmc_fork_tag = EVENTHANDLER_REGISTER(process_fork, 4039 pmc_process_fork, NULL, EVENTHANDLER_PRI_ANY); 4040 4041 /* initialize logging */ 4042 pmclog_initialize(); 4043 4044 /* set hook functions */ 4045 pmc_intr = md->pmd_intr; 4046 pmc_hook = pmc_hook_handler; 4047 4048 if (error == 0) { 4049 printf(PMC_MODULE_NAME ":"); 4050 for (n = 0; n < (int) md->pmd_nclass; n++) { 4051 printf(" %s/%d/0x%b", 4052 pmc_name_of_pmcclass[md->pmd_classes[n].pm_class], 4053 md->pmd_nclasspmcs[n], 4054 md->pmd_classes[n].pm_caps, 4055 "\20" 4056 "\1INT\2USR\3SYS\4EDG\5THR" 4057 "\6REA\7WRI\10INV\11QUA\12PRC" 4058 "\13TAG\14CSC"); 4059 } 4060 printf("\n"); 4061 } 4062 4063 return error; 4064 } 4065 4066 /* prepare to be unloaded */ 4067 static void 4068 pmc_cleanup(void) 4069 { 4070 int cpu; 4071 struct pmc_ownerhash *ph; 4072 struct pmc_owner *po, *tmp; 4073 struct pmc_binding pb; 4074 #if DEBUG 4075 struct pmc_processhash *prh; 4076 #endif 4077 4078 PMCDBG(MOD,INI,0, "%s", "cleanup"); 4079 4080 /* switch off sampling */ 4081 atomic_store_rel_int(&pmc_cpumask, 0); 4082 pmc_intr = NULL; 4083 4084 sx_xlock(&pmc_sx); 4085 if (pmc_hook == NULL) { /* being unloaded already */ 4086 sx_xunlock(&pmc_sx); 4087 return; 4088 } 4089 4090 pmc_hook = NULL; /* prevent new threads from entering module */ 4091 4092 /* deregister event handlers */ 4093 EVENTHANDLER_DEREGISTER(process_fork, pmc_fork_tag); 4094 EVENTHANDLER_DEREGISTER(process_exit, pmc_exit_tag); 4095 4096 /* send SIGBUS to all owner threads, free up allocations */ 4097 if (pmc_ownerhash) 4098 for (ph = pmc_ownerhash; 4099 ph <= &pmc_ownerhash[pmc_ownerhashmask]; 4100 ph++) { 4101 LIST_FOREACH_SAFE(po, ph, po_next, tmp) { 4102 pmc_remove_owner(po); 4103 4104 /* send SIGBUS to owner processes */ 4105 PMCDBG(MOD,INI,2, "cleanup signal proc=%p " 4106 "(%d, %s)", po->po_owner, 4107 po->po_owner->p_pid, 4108 po->po_owner->p_comm); 4109 4110 PROC_LOCK(po->po_owner); 4111 psignal(po->po_owner, SIGBUS); 4112 PROC_UNLOCK(po->po_owner); 4113 4114 pmc_destroy_owner_descriptor(po); 4115 } 4116 } 4117 4118 /* reclaim allocated data structures */ 4119 if (pmc_mtxpool) 4120 mtx_pool_destroy(&pmc_mtxpool); 4121 4122 mtx_destroy(&pmc_processhash_mtx); 4123 if (pmc_processhash) { 4124 #if DEBUG 4125 struct pmc_process *pp; 4126 4127 PMCDBG(MOD,INI,3, "%s", "destroy process hash"); 4128 for (prh = pmc_processhash; 4129 prh <= &pmc_processhash[pmc_processhashmask]; 4130 prh++) 4131 LIST_FOREACH(pp, prh, pp_next) 4132 PMCDBG(MOD,INI,3, "pid=%d", pp->pp_proc->p_pid); 4133 #endif 4134 4135 hashdestroy(pmc_processhash, M_PMC, pmc_processhashmask); 4136 pmc_processhash = NULL; 4137 } 4138 4139 if (pmc_ownerhash) { 4140 PMCDBG(MOD,INI,3, "%s", "destroy owner hash"); 4141 hashdestroy(pmc_ownerhash, M_PMC, pmc_ownerhashmask); 4142 pmc_ownerhash = NULL; 4143 } 4144 4145 KASSERT(LIST_EMPTY(&pmc_ss_owners), 4146 ("[pmc,%d] Global SS owner list not empty", __LINE__)); 4147 KASSERT(pmc_ss_count == 0, 4148 ("[pmc,%d] Global SS count not empty", __LINE__)); 4149 4150 /* do processor dependent cleanup */ 4151 PMCDBG(MOD,INI,3, "%s", "md cleanup"); 4152 if (md) { 4153 pmc_save_cpu_binding(&pb); 4154 for (cpu = 0; cpu < mp_ncpus; cpu++) { 4155 PMCDBG(MOD,INI,1,"pmc-cleanup cpu=%d pcs=%p", 4156 cpu, pmc_pcpu[cpu]); 4157 if (pmc_cpu_is_disabled(cpu)) 4158 continue; 4159 pmc_select_cpu(cpu); 4160 if (pmc_pcpu[cpu]) 4161 (void) md->pmd_cleanup(cpu); 4162 } 4163 FREE(md, M_PMC); 4164 md = NULL; 4165 pmc_restore_cpu_binding(&pb); 4166 } 4167 4168 /* deallocate per-cpu structures */ 4169 FREE(pmc_pcpu, M_PMC); 4170 pmc_pcpu = NULL; 4171 4172 FREE(pmc_pcpu_saved, M_PMC); 4173 pmc_pcpu_saved = NULL; 4174 4175 if (pmc_pmcdisp) { 4176 FREE(pmc_pmcdisp, M_PMC); 4177 pmc_pmcdisp = NULL; 4178 } 4179 4180 pmclog_shutdown(); 4181 4182 sx_xunlock(&pmc_sx); /* we are done */ 4183 } 4184 4185 /* 4186 * The function called at load/unload. 4187 */ 4188 4189 static int 4190 load (struct module *module __unused, int cmd, void *arg __unused) 4191 { 4192 int error; 4193 4194 error = 0; 4195 4196 switch (cmd) { 4197 case MOD_LOAD : 4198 /* initialize the subsystem */ 4199 error = pmc_initialize(); 4200 if (error != 0) 4201 break; 4202 PMCDBG(MOD,INI,1, "syscall=%d ncpus=%d", 4203 pmc_syscall_num, mp_ncpus); 4204 break; 4205 4206 4207 case MOD_UNLOAD : 4208 case MOD_SHUTDOWN: 4209 pmc_cleanup(); 4210 PMCDBG(MOD,INI,1, "%s", "unloaded"); 4211 break; 4212 4213 default : 4214 error = EINVAL; /* XXX should panic(9) */ 4215 break; 4216 } 4217 4218 return error; 4219 } 4220 4221 /* memory pool */ 4222 MALLOC_DEFINE(M_PMC, "pmc", "Memory space for the PMC module"); 4223