1 /*- 2 * Copyright (c) 2003-2006 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 <sys/linker.h> /* needs to be after <sys/malloc.h> */ 57 58 #include <machine/atomic.h> 59 #include <machine/md_var.h> 60 61 /* 62 * Types 63 */ 64 65 enum pmc_flags { 66 PMC_FLAG_NONE = 0x00, /* do nothing */ 67 PMC_FLAG_REMOVE = 0x01, /* atomically remove entry from hash */ 68 PMC_FLAG_ALLOCATE = 0x02, /* add entry to hash if not found */ 69 }; 70 71 /* 72 * The offset in sysent where the syscall is allocated. 73 */ 74 75 static int pmc_syscall_num = NO_SYSCALL; 76 struct pmc_cpu **pmc_pcpu; /* per-cpu state */ 77 pmc_value_t *pmc_pcpu_saved; /* saved PMC values: CSW handling */ 78 79 #define PMC_PCPU_SAVED(C,R) pmc_pcpu_saved[(R) + md->pmd_npmc*(C)] 80 81 struct mtx_pool *pmc_mtxpool; 82 static int *pmc_pmcdisp; /* PMC row dispositions */ 83 84 #define PMC_ROW_DISP_IS_FREE(R) (pmc_pmcdisp[(R)] == 0) 85 #define PMC_ROW_DISP_IS_THREAD(R) (pmc_pmcdisp[(R)] > 0) 86 #define PMC_ROW_DISP_IS_STANDALONE(R) (pmc_pmcdisp[(R)] < 0) 87 88 #define PMC_MARK_ROW_FREE(R) do { \ 89 pmc_pmcdisp[(R)] = 0; \ 90 } while (0) 91 92 #define PMC_MARK_ROW_STANDALONE(R) do { \ 93 KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \ 94 __LINE__)); \ 95 atomic_add_int(&pmc_pmcdisp[(R)], -1); \ 96 KASSERT(pmc_pmcdisp[(R)] >= (-mp_ncpus), ("[pmc,%d] row " \ 97 "disposition error", __LINE__)); \ 98 } while (0) 99 100 #define PMC_UNMARK_ROW_STANDALONE(R) do { \ 101 atomic_add_int(&pmc_pmcdisp[(R)], 1); \ 102 KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \ 103 __LINE__)); \ 104 } while (0) 105 106 #define PMC_MARK_ROW_THREAD(R) do { \ 107 KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \ 108 __LINE__)); \ 109 atomic_add_int(&pmc_pmcdisp[(R)], 1); \ 110 } while (0) 111 112 #define PMC_UNMARK_ROW_THREAD(R) do { \ 113 atomic_add_int(&pmc_pmcdisp[(R)], -1); \ 114 KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \ 115 __LINE__)); \ 116 } while (0) 117 118 119 /* various event handlers */ 120 static eventhandler_tag pmc_exit_tag, pmc_fork_tag; 121 122 /* Module statistics */ 123 struct pmc_op_getdriverstats pmc_stats; 124 125 /* Machine/processor dependent operations */ 126 struct pmc_mdep *md; 127 128 /* 129 * Hash tables mapping owner processes and target threads to PMCs. 130 */ 131 132 struct mtx pmc_processhash_mtx; /* spin mutex */ 133 static u_long pmc_processhashmask; 134 static LIST_HEAD(pmc_processhash, pmc_process) *pmc_processhash; 135 136 /* 137 * Hash table of PMC owner descriptors. This table is protected by 138 * the shared PMC "sx" lock. 139 */ 140 141 static u_long pmc_ownerhashmask; 142 static LIST_HEAD(pmc_ownerhash, pmc_owner) *pmc_ownerhash; 143 144 /* 145 * List of PMC owners with system-wide sampling PMCs. 146 */ 147 148 static LIST_HEAD(, pmc_owner) pmc_ss_owners; 149 150 151 /* 152 * Prototypes 153 */ 154 155 #ifdef DEBUG 156 static int pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS); 157 static int pmc_debugflags_parse(char *newstr, char *fence); 158 #endif 159 160 static int load(struct module *module, int cmd, void *arg); 161 static int pmc_attach_process(struct proc *p, struct pmc *pm); 162 static struct pmc *pmc_allocate_pmc_descriptor(void); 163 static struct pmc_owner *pmc_allocate_owner_descriptor(struct proc *p); 164 static int pmc_attach_one_process(struct proc *p, struct pmc *pm); 165 static int pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, 166 int cpu); 167 static int pmc_can_attach(struct pmc *pm, struct proc *p); 168 static void pmc_cleanup(void); 169 static int pmc_detach_process(struct proc *p, struct pmc *pm); 170 static int pmc_detach_one_process(struct proc *p, struct pmc *pm, 171 int flags); 172 static void pmc_destroy_owner_descriptor(struct pmc_owner *po); 173 static struct pmc_owner *pmc_find_owner_descriptor(struct proc *p); 174 static int pmc_find_pmc(pmc_id_t pmcid, struct pmc **pm); 175 static struct pmc *pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, 176 pmc_id_t pmc); 177 static struct pmc_process *pmc_find_process_descriptor(struct proc *p, 178 uint32_t mode); 179 static void pmc_force_context_switch(void); 180 static void pmc_link_target_process(struct pmc *pm, 181 struct pmc_process *pp); 182 static void pmc_maybe_remove_owner(struct pmc_owner *po); 183 static void pmc_process_csw_in(struct thread *td); 184 static void pmc_process_csw_out(struct thread *td); 185 static void pmc_process_exit(void *arg, struct proc *p); 186 static void pmc_process_fork(void *arg, struct proc *p1, 187 struct proc *p2, int n); 188 static void pmc_process_samples(int cpu); 189 static void pmc_release_pmc_descriptor(struct pmc *pmc); 190 static void pmc_remove_owner(struct pmc_owner *po); 191 static void pmc_remove_process_descriptor(struct pmc_process *pp); 192 static void pmc_restore_cpu_binding(struct pmc_binding *pb); 193 static void pmc_save_cpu_binding(struct pmc_binding *pb); 194 static void pmc_select_cpu(int cpu); 195 static int pmc_start(struct pmc *pm); 196 static int pmc_stop(struct pmc *pm); 197 static int pmc_syscall_handler(struct thread *td, void *syscall_args); 198 static void pmc_unlink_target_process(struct pmc *pmc, 199 struct pmc_process *pp); 200 201 /* 202 * Kernel tunables and sysctl(8) interface. 203 */ 204 205 SYSCTL_NODE(_kern, OID_AUTO, hwpmc, CTLFLAG_RW, 0, "HWPMC parameters"); 206 207 #ifdef DEBUG 208 struct pmc_debugflags pmc_debugflags = PMC_DEBUG_DEFAULT_FLAGS; 209 char pmc_debugstr[PMC_DEBUG_STRSIZE]; 210 TUNABLE_STR(PMC_SYSCTL_NAME_PREFIX "debugflags", pmc_debugstr, 211 sizeof(pmc_debugstr)); 212 SYSCTL_PROC(_kern_hwpmc, OID_AUTO, debugflags, 213 CTLTYPE_STRING|CTLFLAG_RW|CTLFLAG_TUN, 214 0, 0, pmc_debugflags_sysctl_handler, "A", "debug flags"); 215 #endif 216 217 /* 218 * kern.hwpmc.hashrows -- determines the number of rows in the 219 * of the hash table used to look up threads 220 */ 221 222 static int pmc_hashsize = PMC_HASH_SIZE; 223 TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "hashsize", &pmc_hashsize); 224 SYSCTL_INT(_kern_hwpmc, OID_AUTO, hashsize, CTLFLAG_TUN|CTLFLAG_RD, 225 &pmc_hashsize, 0, "rows in hash tables"); 226 227 /* 228 * kern.hwpmc.nsamples --- number of PC samples per CPU 229 */ 230 231 static int pmc_nsamples = PMC_NSAMPLES; 232 TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "nsamples", &pmc_nsamples); 233 SYSCTL_INT(_kern_hwpmc, OID_AUTO, nsamples, CTLFLAG_TUN|CTLFLAG_RD, 234 &pmc_nsamples, 0, "number of PC samples per CPU"); 235 236 /* 237 * kern.hwpmc.mtxpoolsize -- number of mutexes in the mutex pool. 238 */ 239 240 static int pmc_mtxpool_size = PMC_MTXPOOL_SIZE; 241 TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "mtxpoolsize", &pmc_mtxpool_size); 242 SYSCTL_INT(_kern_hwpmc, OID_AUTO, mtxpoolsize, CTLFLAG_TUN|CTLFLAG_RD, 243 &pmc_mtxpool_size, 0, "size of spin mutex pool"); 244 245 246 /* 247 * security.bsd.unprivileged_syspmcs -- allow non-root processes to 248 * allocate system-wide PMCs. 249 * 250 * Allowing unprivileged processes to allocate system PMCs is convenient 251 * if system-wide measurements need to be taken concurrently with other 252 * per-process measurements. This feature is turned off by default. 253 */ 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 #ifdef 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 { 647 648 (void) tsleep((void *) pmc_force_context_switch, 0, "pmcctx", 1); 649 } 650 651 /* 652 * Get the file name for an executable. This is a simple wrapper 653 * around vn_fullpath(9). 654 */ 655 656 static void 657 pmc_getfilename(struct vnode *v, char **fullpath, char **freepath) 658 { 659 struct thread *td; 660 661 td = curthread; 662 *fullpath = "unknown"; 663 *freepath = NULL; 664 vn_lock(v, LK_CANRECURSE | LK_EXCLUSIVE | LK_RETRY, td); 665 vn_fullpath(td, v, fullpath, freepath); 666 VOP_UNLOCK(v, 0, td); 667 } 668 669 /* 670 * remove an process owning PMCs 671 */ 672 673 void 674 pmc_remove_owner(struct pmc_owner *po) 675 { 676 struct pmc *pm, *tmp; 677 678 sx_assert(&pmc_sx, SX_XLOCKED); 679 680 PMCDBG(OWN,ORM,1, "remove-owner po=%p", po); 681 682 /* Remove descriptor from the owner hash table */ 683 LIST_REMOVE(po, po_next); 684 685 /* release all owned PMC descriptors */ 686 LIST_FOREACH_SAFE(pm, &po->po_pmcs, pm_next, tmp) { 687 PMCDBG(OWN,ORM,2, "pmc=%p", pm); 688 KASSERT(pm->pm_owner == po, 689 ("[pmc,%d] owner %p != po %p", __LINE__, pm->pm_owner, po)); 690 691 pmc_release_pmc_descriptor(pm); /* will unlink from the list */ 692 } 693 694 KASSERT(po->po_sscount == 0, 695 ("[pmc,%d] SS count not zero", __LINE__)); 696 KASSERT(LIST_EMPTY(&po->po_pmcs), 697 ("[pmc,%d] PMC list not empty", __LINE__)); 698 699 /* de-configure the log file if present */ 700 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 701 pmclog_deconfigure_log(po); 702 } 703 704 /* 705 * remove an owner process record if all conditions are met. 706 */ 707 708 static void 709 pmc_maybe_remove_owner(struct pmc_owner *po) 710 { 711 712 PMCDBG(OWN,OMR,1, "maybe-remove-owner po=%p", po); 713 714 /* 715 * Remove owner record if 716 * - this process does not own any PMCs 717 * - this process has not allocated a system-wide sampling buffer 718 */ 719 720 if (LIST_EMPTY(&po->po_pmcs) && 721 ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0)) { 722 pmc_remove_owner(po); 723 pmc_destroy_owner_descriptor(po); 724 } 725 } 726 727 /* 728 * Add an association between a target process and a PMC. 729 */ 730 731 static void 732 pmc_link_target_process(struct pmc *pm, struct pmc_process *pp) 733 { 734 int ri; 735 struct pmc_target *pt; 736 737 sx_assert(&pmc_sx, SX_XLOCKED); 738 739 KASSERT(pm != NULL && pp != NULL, 740 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 741 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 742 ("[pmc,%d] Attaching a non-process-virtual pmc=%p to pid=%d", 743 __LINE__, pm, pp->pp_proc->p_pid)); 744 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt < ((int) md->pmd_npmc - 1), 745 ("[pmc,%d] Illegal reference count %d for process record %p", 746 __LINE__, pp->pp_refcnt, (void *) pp)); 747 748 ri = PMC_TO_ROWINDEX(pm); 749 750 PMCDBG(PRC,TLK,1, "link-target pmc=%p ri=%d pmc-process=%p", 751 pm, ri, pp); 752 753 #ifdef DEBUG 754 LIST_FOREACH(pt, &pm->pm_targets, pt_next) 755 if (pt->pt_process == pp) 756 KASSERT(0, ("[pmc,%d] pp %p already in pmc %p targets", 757 __LINE__, pp, pm)); 758 #endif 759 760 MALLOC(pt, struct pmc_target *, sizeof(struct pmc_target), 761 M_PMC, M_ZERO|M_WAITOK); 762 763 pt->pt_process = pp; 764 765 LIST_INSERT_HEAD(&pm->pm_targets, pt, pt_next); 766 767 atomic_store_rel_ptr((uintptr_t *)&pp->pp_pmcs[ri].pp_pmc, 768 (uintptr_t)pm); 769 770 if (pm->pm_owner->po_owner == pp->pp_proc) 771 pm->pm_flags |= PMC_F_ATTACHED_TO_OWNER; 772 773 /* 774 * Initialize the per-process values at this row index. 775 */ 776 pp->pp_pmcs[ri].pp_pmcval = PMC_TO_MODE(pm) == PMC_MODE_TS ? 777 pm->pm_sc.pm_reloadcount : 0; 778 779 pp->pp_refcnt++; 780 781 } 782 783 /* 784 * Removes the association between a target process and a PMC. 785 */ 786 787 static void 788 pmc_unlink_target_process(struct pmc *pm, struct pmc_process *pp) 789 { 790 int ri; 791 struct proc *p; 792 struct pmc_target *ptgt; 793 794 sx_assert(&pmc_sx, SX_XLOCKED); 795 796 KASSERT(pm != NULL && pp != NULL, 797 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 798 799 KASSERT(pp->pp_refcnt >= 1 && pp->pp_refcnt < (int) md->pmd_npmc, 800 ("[pmc,%d] Illegal ref count %d on process record %p", 801 __LINE__, pp->pp_refcnt, (void *) pp)); 802 803 ri = PMC_TO_ROWINDEX(pm); 804 805 PMCDBG(PRC,TUL,1, "unlink-target pmc=%p ri=%d pmc-process=%p", 806 pm, ri, pp); 807 808 KASSERT(pp->pp_pmcs[ri].pp_pmc == pm, 809 ("[pmc,%d] PMC ri %d mismatch pmc %p pp->[ri] %p", __LINE__, 810 ri, pm, pp->pp_pmcs[ri].pp_pmc)); 811 812 pp->pp_pmcs[ri].pp_pmc = NULL; 813 pp->pp_pmcs[ri].pp_pmcval = (pmc_value_t) 0; 814 815 /* Remove owner-specific flags */ 816 if (pm->pm_owner->po_owner == pp->pp_proc) { 817 pp->pp_flags &= ~PMC_PP_ENABLE_MSR_ACCESS; 818 pm->pm_flags &= ~PMC_F_ATTACHED_TO_OWNER; 819 } 820 821 pp->pp_refcnt--; 822 823 /* Remove the target process from the PMC structure */ 824 LIST_FOREACH(ptgt, &pm->pm_targets, pt_next) 825 if (ptgt->pt_process == pp) 826 break; 827 828 KASSERT(ptgt != NULL, ("[pmc,%d] process %p (pp: %p) not found " 829 "in pmc %p", __LINE__, pp->pp_proc, pp, pm)); 830 831 LIST_REMOVE(ptgt, pt_next); 832 FREE(ptgt, M_PMC); 833 834 /* if the PMC now lacks targets, send the owner a SIGIO */ 835 if (LIST_EMPTY(&pm->pm_targets)) { 836 p = pm->pm_owner->po_owner; 837 PROC_LOCK(p); 838 psignal(p, SIGIO); 839 PROC_UNLOCK(p); 840 841 PMCDBG(PRC,SIG,2, "signalling proc=%p signal=%d", p, 842 SIGIO); 843 } 844 } 845 846 /* 847 * Check if PMC 'pm' may be attached to target process 't'. 848 */ 849 850 static int 851 pmc_can_attach(struct pmc *pm, struct proc *t) 852 { 853 struct proc *o; /* pmc owner */ 854 struct ucred *oc, *tc; /* owner, target credentials */ 855 int decline_attach, i; 856 857 /* 858 * A PMC's owner can always attach that PMC to itself. 859 */ 860 861 if ((o = pm->pm_owner->po_owner) == t) 862 return 0; 863 864 PROC_LOCK(o); 865 oc = o->p_ucred; 866 crhold(oc); 867 PROC_UNLOCK(o); 868 869 PROC_LOCK(t); 870 tc = t->p_ucred; 871 crhold(tc); 872 PROC_UNLOCK(t); 873 874 /* 875 * The effective uid of the PMC owner should match at least one 876 * of the {effective,real,saved} uids of the target process. 877 */ 878 879 decline_attach = oc->cr_uid != tc->cr_uid && 880 oc->cr_uid != tc->cr_svuid && 881 oc->cr_uid != tc->cr_ruid; 882 883 /* 884 * Every one of the target's group ids, must be in the owner's 885 * group list. 886 */ 887 for (i = 0; !decline_attach && i < tc->cr_ngroups; i++) 888 decline_attach = !groupmember(tc->cr_groups[i], oc); 889 890 /* check the read and saved gids too */ 891 if (decline_attach == 0) 892 decline_attach = !groupmember(tc->cr_rgid, oc) || 893 !groupmember(tc->cr_svgid, oc); 894 895 crfree(tc); 896 crfree(oc); 897 898 return !decline_attach; 899 } 900 901 /* 902 * Attach a process to a PMC. 903 */ 904 905 static int 906 pmc_attach_one_process(struct proc *p, struct pmc *pm) 907 { 908 int ri; 909 char *fullpath, *freepath; 910 struct pmc_process *pp; 911 912 sx_assert(&pmc_sx, SX_XLOCKED); 913 914 PMCDBG(PRC,ATT,2, "attach-one pm=%p ri=%d proc=%p (%d, %s)", pm, 915 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 916 917 /* 918 * Locate the process descriptor corresponding to process 'p', 919 * allocating space as needed. 920 * 921 * Verify that rowindex 'pm_rowindex' is free in the process 922 * descriptor. 923 * 924 * If not, allocate space for a descriptor and link the 925 * process descriptor and PMC. 926 */ 927 ri = PMC_TO_ROWINDEX(pm); 928 929 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_ALLOCATE)) == NULL) 930 return ENOMEM; 931 932 if (pp->pp_pmcs[ri].pp_pmc == pm) /* already present at slot [ri] */ 933 return EEXIST; 934 935 if (pp->pp_pmcs[ri].pp_pmc != NULL) 936 return EBUSY; 937 938 pmc_link_target_process(pm, pp); 939 940 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) && 941 (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) == 0) 942 pm->pm_flags |= PMC_F_NEEDS_LOGFILE; 943 944 pm->pm_flags |= PMC_F_ATTACH_DONE; /* mark as attached */ 945 946 /* issue an attach event to a configured log file */ 947 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) { 948 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 949 pmclog_process_pmcattach(pm, p->p_pid, fullpath); 950 if (freepath) 951 FREE(freepath, M_TEMP); 952 } 953 /* mark process as using HWPMCs */ 954 PROC_LOCK(p); 955 p->p_flag |= P_HWPMC; 956 PROC_UNLOCK(p); 957 958 return 0; 959 } 960 961 /* 962 * Attach a process and optionally its children 963 */ 964 965 static int 966 pmc_attach_process(struct proc *p, struct pmc *pm) 967 { 968 int error; 969 struct proc *top; 970 971 sx_assert(&pmc_sx, SX_XLOCKED); 972 973 PMCDBG(PRC,ATT,1, "attach pm=%p ri=%d proc=%p (%d, %s)", pm, 974 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 975 976 977 /* 978 * If this PMC successfully allowed a GETMSR operation 979 * in the past, disallow further ATTACHes. 980 */ 981 982 if ((pm->pm_flags & PMC_PP_ENABLE_MSR_ACCESS) != 0) 983 return EPERM; 984 985 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 986 return pmc_attach_one_process(p, pm); 987 988 /* 989 * Traverse all child processes, attaching them to 990 * this PMC. 991 */ 992 993 sx_slock(&proctree_lock); 994 995 top = p; 996 997 for (;;) { 998 if ((error = pmc_attach_one_process(p, pm)) != 0) 999 break; 1000 if (!LIST_EMPTY(&p->p_children)) 1001 p = LIST_FIRST(&p->p_children); 1002 else for (;;) { 1003 if (p == top) 1004 goto done; 1005 if (LIST_NEXT(p, p_sibling)) { 1006 p = LIST_NEXT(p, p_sibling); 1007 break; 1008 } 1009 p = p->p_pptr; 1010 } 1011 } 1012 1013 if (error) 1014 (void) pmc_detach_process(top, pm); 1015 1016 done: 1017 sx_sunlock(&proctree_lock); 1018 return error; 1019 } 1020 1021 /* 1022 * Detach a process from a PMC. If there are no other PMCs tracking 1023 * this process, remove the process structure from its hash table. If 1024 * 'flags' contains PMC_FLAG_REMOVE, then free the process structure. 1025 */ 1026 1027 static int 1028 pmc_detach_one_process(struct proc *p, struct pmc *pm, int flags) 1029 { 1030 int ri; 1031 struct pmc_process *pp; 1032 1033 sx_assert(&pmc_sx, SX_XLOCKED); 1034 1035 KASSERT(pm != NULL, 1036 ("[pmc,%d] null pm pointer", __LINE__)); 1037 1038 ri = PMC_TO_ROWINDEX(pm); 1039 1040 PMCDBG(PRC,ATT,2, "detach-one pm=%p ri=%d proc=%p (%d, %s) flags=0x%x", 1041 pm, ri, p, p->p_pid, p->p_comm, flags); 1042 1043 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) 1044 return ESRCH; 1045 1046 if (pp->pp_pmcs[ri].pp_pmc != pm) 1047 return EINVAL; 1048 1049 pmc_unlink_target_process(pm, pp); 1050 1051 /* Issue a detach entry if a log file is configured */ 1052 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) 1053 pmclog_process_pmcdetach(pm, p->p_pid); 1054 1055 /* 1056 * If there are no PMCs targetting this process, we remove its 1057 * descriptor from the target hash table and unset the P_HWPMC 1058 * flag in the struct proc. 1059 */ 1060 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt < (int) md->pmd_npmc, 1061 ("[pmc,%d] Illegal refcnt %d for process struct %p", 1062 __LINE__, pp->pp_refcnt, pp)); 1063 1064 if (pp->pp_refcnt != 0) /* still a target of some PMC */ 1065 return 0; 1066 1067 pmc_remove_process_descriptor(pp); 1068 1069 if (flags & PMC_FLAG_REMOVE) 1070 FREE(pp, M_PMC); 1071 1072 PROC_LOCK(p); 1073 p->p_flag &= ~P_HWPMC; 1074 PROC_UNLOCK(p); 1075 1076 return 0; 1077 } 1078 1079 /* 1080 * Detach a process and optionally its descendants from a PMC. 1081 */ 1082 1083 static int 1084 pmc_detach_process(struct proc *p, struct pmc *pm) 1085 { 1086 struct proc *top; 1087 1088 sx_assert(&pmc_sx, SX_XLOCKED); 1089 1090 PMCDBG(PRC,ATT,1, "detach pm=%p ri=%d proc=%p (%d, %s)", pm, 1091 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1092 1093 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 1094 return pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); 1095 1096 /* 1097 * Traverse all children, detaching them from this PMC. We 1098 * ignore errors since we could be detaching a PMC from a 1099 * partially attached proc tree. 1100 */ 1101 1102 sx_slock(&proctree_lock); 1103 1104 top = p; 1105 1106 for (;;) { 1107 (void) pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); 1108 1109 if (!LIST_EMPTY(&p->p_children)) 1110 p = LIST_FIRST(&p->p_children); 1111 else for (;;) { 1112 if (p == top) 1113 goto done; 1114 if (LIST_NEXT(p, p_sibling)) { 1115 p = LIST_NEXT(p, p_sibling); 1116 break; 1117 } 1118 p = p->p_pptr; 1119 } 1120 } 1121 1122 done: 1123 sx_sunlock(&proctree_lock); 1124 1125 if (LIST_EMPTY(&pm->pm_targets)) 1126 pm->pm_flags &= ~PMC_F_ATTACH_DONE; 1127 1128 return 0; 1129 } 1130 1131 1132 /* 1133 * Thread context switch IN 1134 */ 1135 1136 static void 1137 pmc_process_csw_in(struct thread *td) 1138 { 1139 int cpu; 1140 unsigned int ri; 1141 struct pmc *pm; 1142 struct proc *p; 1143 struct pmc_cpu *pc; 1144 struct pmc_hw *phw; 1145 struct pmc_process *pp; 1146 pmc_value_t newvalue; 1147 1148 p = td->td_proc; 1149 1150 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE)) == NULL) 1151 return; 1152 1153 KASSERT(pp->pp_proc == td->td_proc, 1154 ("[pmc,%d] not my thread state", __LINE__)); 1155 1156 critical_enter(); /* no preemption from this point */ 1157 1158 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1159 1160 PMCDBG(CSW,SWI,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1161 p->p_pid, p->p_comm, pp); 1162 1163 KASSERT(cpu >= 0 && cpu < mp_ncpus, 1164 ("[pmc,%d] wierd CPU id %d", __LINE__, cpu)); 1165 1166 pc = pmc_pcpu[cpu]; 1167 1168 for (ri = 0; ri < md->pmd_npmc; ri++) { 1169 1170 if ((pm = pp->pp_pmcs[ri].pp_pmc) == NULL) 1171 continue; 1172 1173 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 1174 ("[pmc,%d] Target PMC in non-virtual mode (%d)", 1175 __LINE__, PMC_TO_MODE(pm))); 1176 1177 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1178 ("[pmc,%d] Row index mismatch pmc %d != ri %d", 1179 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1180 1181 /* 1182 * Only PMCs that are marked as 'RUNNING' need 1183 * be placed on hardware. 1184 */ 1185 1186 if (pm->pm_state != PMC_STATE_RUNNING) 1187 continue; 1188 1189 /* increment PMC runcount */ 1190 atomic_add_rel_32(&pm->pm_runcount, 1); 1191 1192 /* configure the HWPMC we are going to use. */ 1193 md->pmd_config_pmc(cpu, ri, pm); 1194 1195 phw = pc->pc_hwpmcs[ri]; 1196 1197 KASSERT(phw != NULL, 1198 ("[pmc,%d] null hw pointer", __LINE__)); 1199 1200 KASSERT(phw->phw_pmc == pm, 1201 ("[pmc,%d] hw->pmc %p != pmc %p", __LINE__, 1202 phw->phw_pmc, pm)); 1203 1204 /* 1205 * Write out saved value and start the PMC. 1206 * 1207 * Sampling PMCs use a per-process value, while 1208 * counting mode PMCs use a per-pmc value that is 1209 * inherited across descendants. 1210 */ 1211 if (PMC_TO_MODE(pm) == PMC_MODE_TS) { 1212 mtx_pool_lock_spin(pmc_mtxpool, pm); 1213 newvalue = PMC_PCPU_SAVED(cpu,ri) = 1214 pp->pp_pmcs[ri].pp_pmcval; 1215 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1216 } else { 1217 KASSERT(PMC_TO_MODE(pm) == PMC_MODE_TC, 1218 ("[pmc,%d] illegal mode=%d", __LINE__, 1219 PMC_TO_MODE(pm))); 1220 mtx_pool_lock_spin(pmc_mtxpool, pm); 1221 newvalue = PMC_PCPU_SAVED(cpu, ri) = 1222 pm->pm_gv.pm_savedvalue; 1223 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1224 } 1225 1226 PMCDBG(CSW,SWI,1,"cpu=%d ri=%d new=%jd", cpu, ri, newvalue); 1227 1228 md->pmd_write_pmc(cpu, ri, newvalue); 1229 md->pmd_start_pmc(cpu, ri); 1230 } 1231 1232 /* 1233 * perform any other architecture/cpu dependent thread 1234 * switch-in actions. 1235 */ 1236 1237 (void) (*md->pmd_switch_in)(pc, pp); 1238 1239 critical_exit(); 1240 1241 } 1242 1243 /* 1244 * Thread context switch OUT. 1245 */ 1246 1247 static void 1248 pmc_process_csw_out(struct thread *td) 1249 { 1250 int cpu; 1251 enum pmc_mode mode; 1252 unsigned int ri; 1253 struct pmc *pm; 1254 struct proc *p; 1255 struct pmc_cpu *pc; 1256 struct pmc_process *pp; 1257 int64_t tmp; 1258 pmc_value_t newvalue; 1259 1260 /* 1261 * Locate our process descriptor; this may be NULL if 1262 * this process is exiting and we have already removed 1263 * the process from the target process table. 1264 * 1265 * Note that due to kernel preemption, multiple 1266 * context switches may happen while the process is 1267 * exiting. 1268 * 1269 * Note also that if the target process cannot be 1270 * found we still need to deconfigure any PMCs that 1271 * are currently running on hardware. 1272 */ 1273 1274 p = td->td_proc; 1275 pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE); 1276 1277 /* 1278 * save PMCs 1279 */ 1280 1281 critical_enter(); 1282 1283 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1284 1285 PMCDBG(CSW,SWO,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1286 p->p_pid, p->p_comm, pp); 1287 1288 KASSERT(cpu >= 0 && cpu < mp_ncpus, 1289 ("[pmc,%d wierd CPU id %d", __LINE__, cpu)); 1290 1291 pc = pmc_pcpu[cpu]; 1292 1293 /* 1294 * When a PMC gets unlinked from a target PMC, it will 1295 * be removed from the target's pp_pmc[] array. 1296 * 1297 * However, on a MP system, the target could have been 1298 * executing on another CPU at the time of the unlink. 1299 * So, at context switch OUT time, we need to look at 1300 * the hardware to determine if a PMC is scheduled on 1301 * it. 1302 */ 1303 1304 for (ri = 0; ri < md->pmd_npmc; ri++) { 1305 1306 pm = NULL; 1307 (void) (*md->pmd_get_config)(cpu, ri, &pm); 1308 1309 if (pm == NULL) /* nothing at this row index */ 1310 continue; 1311 1312 mode = PMC_TO_MODE(pm); 1313 if (!PMC_IS_VIRTUAL_MODE(mode)) 1314 continue; /* not a process virtual PMC */ 1315 1316 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1317 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 1318 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1319 1320 /* Stop hardware if not already stopped */ 1321 if (pm->pm_stalled == 0) 1322 md->pmd_stop_pmc(cpu, ri); 1323 1324 /* reduce this PMC's runcount */ 1325 atomic_subtract_rel_32(&pm->pm_runcount, 1); 1326 1327 /* 1328 * If this PMC is associated with this process, 1329 * save the reading. 1330 */ 1331 1332 if (pp != NULL && pp->pp_pmcs[ri].pp_pmc != NULL) { 1333 1334 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 1335 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", __LINE__, 1336 pm, ri, pp->pp_pmcs[ri].pp_pmc)); 1337 1338 KASSERT(pp->pp_refcnt > 0, 1339 ("[pmc,%d] pp refcnt = %d", __LINE__, 1340 pp->pp_refcnt)); 1341 1342 md->pmd_read_pmc(cpu, ri, &newvalue); 1343 1344 tmp = newvalue - PMC_PCPU_SAVED(cpu,ri); 1345 1346 PMCDBG(CSW,SWI,1,"cpu=%d ri=%d tmp=%jd", cpu, ri, 1347 tmp); 1348 1349 if (mode == PMC_MODE_TS) { 1350 1351 /* 1352 * For sampling process-virtual PMCs, 1353 * we expect the count to be 1354 * decreasing as the 'value' 1355 * programmed into the PMC is the 1356 * number of events to be seen till 1357 * the next sampling interrupt. 1358 */ 1359 if (tmp < 0) 1360 tmp += pm->pm_sc.pm_reloadcount; 1361 mtx_pool_lock_spin(pmc_mtxpool, pm); 1362 pp->pp_pmcs[ri].pp_pmcval -= tmp; 1363 if ((int64_t) pp->pp_pmcs[ri].pp_pmcval < 0) 1364 pp->pp_pmcs[ri].pp_pmcval += 1365 pm->pm_sc.pm_reloadcount; 1366 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1367 1368 } else { 1369 1370 /* 1371 * For counting process-virtual PMCs, 1372 * we expect the count to be 1373 * increasing monotonically, modulo a 64 1374 * bit wraparound. 1375 */ 1376 KASSERT((int64_t) tmp >= 0, 1377 ("[pmc,%d] negative increment cpu=%d " 1378 "ri=%d newvalue=%jx saved=%jx " 1379 "incr=%jx", __LINE__, cpu, ri, 1380 newvalue, PMC_PCPU_SAVED(cpu,ri), tmp)); 1381 1382 mtx_pool_lock_spin(pmc_mtxpool, pm); 1383 pm->pm_gv.pm_savedvalue += tmp; 1384 pp->pp_pmcs[ri].pp_pmcval += tmp; 1385 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1386 1387 if (pm->pm_flags & PMC_F_LOG_PROCCSW) 1388 pmclog_process_proccsw(pm, pp, tmp); 1389 } 1390 } 1391 1392 /* mark hardware as free */ 1393 md->pmd_config_pmc(cpu, ri, NULL); 1394 } 1395 1396 /* 1397 * perform any other architecture/cpu dependent thread 1398 * switch out functions. 1399 */ 1400 1401 (void) (*md->pmd_switch_out)(pc, pp); 1402 1403 critical_exit(); 1404 } 1405 1406 /* 1407 * Log a KLD operation. 1408 */ 1409 1410 static void 1411 pmc_process_kld_load(struct pmckern_map_in *pkm) 1412 { 1413 struct pmc_owner *po; 1414 1415 sx_assert(&pmc_sx, SX_LOCKED); 1416 1417 /* 1418 * Notify owners of system sampling PMCs about KLD operations. 1419 */ 1420 1421 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1422 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1423 pmclog_process_map_in(po, (pid_t) -1, pkm->pm_address, 1424 (char *) pkm->pm_file); 1425 1426 /* 1427 * TODO: Notify owners of (all) process-sampling PMCs too. 1428 */ 1429 1430 return; 1431 } 1432 1433 static void 1434 pmc_process_kld_unload(struct pmckern_map_out *pkm) 1435 { 1436 struct pmc_owner *po; 1437 1438 sx_assert(&pmc_sx, SX_LOCKED); 1439 1440 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1441 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1442 pmclog_process_map_out(po, (pid_t) -1, 1443 pkm->pm_address, pkm->pm_address + pkm->pm_size); 1444 1445 /* 1446 * TODO: Notify owners of process-sampling PMCs. 1447 */ 1448 } 1449 1450 /* 1451 * A mapping change for a process. 1452 */ 1453 1454 static void 1455 pmc_process_mmap(struct thread *td, struct pmckern_map_in *pkm) 1456 { 1457 int ri; 1458 pid_t pid; 1459 char *fullpath, *freepath; 1460 const struct pmc *pm; 1461 struct pmc_owner *po; 1462 const struct pmc_process *pp; 1463 1464 freepath = fullpath = NULL; 1465 pmc_getfilename((struct vnode *) pkm->pm_file, &fullpath, &freepath); 1466 1467 pid = td->td_proc->p_pid; 1468 1469 /* Inform owners of all system-wide sampling PMCs. */ 1470 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1471 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1472 pmclog_process_map_in(po, pid, pkm->pm_address, fullpath); 1473 1474 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1475 goto done; 1476 1477 /* 1478 * Inform sampling PMC owners tracking this process. 1479 */ 1480 for (ri = 0; ri < md->pmd_npmc; ri++) 1481 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1482 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1483 pmclog_process_map_in(pm->pm_owner, 1484 pid, pkm->pm_address, fullpath); 1485 1486 done: 1487 if (freepath) 1488 FREE(freepath, M_TEMP); 1489 } 1490 1491 1492 /* 1493 * Log an munmap request. 1494 */ 1495 1496 static void 1497 pmc_process_munmap(struct thread *td, struct pmckern_map_out *pkm) 1498 { 1499 int ri; 1500 pid_t pid; 1501 struct pmc_owner *po; 1502 const struct pmc *pm; 1503 const struct pmc_process *pp; 1504 1505 pid = td->td_proc->p_pid; 1506 1507 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1508 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1509 pmclog_process_map_out(po, pid, pkm->pm_address, 1510 pkm->pm_address + pkm->pm_size); 1511 1512 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1513 return; 1514 1515 for (ri = 0; ri < md->pmd_npmc; ri++) 1516 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1517 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1518 pmclog_process_map_out(pm->pm_owner, pid, 1519 pkm->pm_address, pkm->pm_address + pkm->pm_size); 1520 } 1521 1522 /* 1523 * The 'hook' invoked from the kernel proper 1524 */ 1525 1526 1527 #ifdef DEBUG 1528 const char *pmc_hooknames[] = { 1529 /* these strings correspond to PMC_FN_* in <sys/pmckern.h> */ 1530 "", 1531 "EXEC", 1532 "CSW-IN", 1533 "CSW-OUT", 1534 "SAMPLE", 1535 "KLDLOAD", 1536 "KLDUNLOAD", 1537 "MMAP", 1538 "MUNMAP" 1539 }; 1540 #endif 1541 1542 static int 1543 pmc_hook_handler(struct thread *td, int function, void *arg) 1544 { 1545 1546 PMCDBG(MOD,PMH,1, "hook td=%p func=%d \"%s\" arg=%p", td, function, 1547 pmc_hooknames[function], arg); 1548 1549 switch (function) 1550 { 1551 1552 /* 1553 * Process exec() 1554 */ 1555 1556 case PMC_FN_PROCESS_EXEC: 1557 { 1558 char *fullpath, *freepath; 1559 unsigned int ri; 1560 int is_using_hwpmcs; 1561 struct pmc *pm; 1562 struct proc *p; 1563 struct pmc_owner *po; 1564 struct pmc_process *pp; 1565 struct pmckern_procexec *pk; 1566 1567 sx_assert(&pmc_sx, SX_XLOCKED); 1568 1569 p = td->td_proc; 1570 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 1571 1572 pk = (struct pmckern_procexec *) arg; 1573 1574 /* Inform owners of SS mode PMCs of the exec event. */ 1575 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1576 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1577 pmclog_process_procexec(po, PMC_ID_INVALID, 1578 p->p_pid, pk->pm_entryaddr, fullpath); 1579 1580 PROC_LOCK(p); 1581 is_using_hwpmcs = p->p_flag & P_HWPMC; 1582 PROC_UNLOCK(p); 1583 1584 if (!is_using_hwpmcs) { 1585 if (freepath) 1586 FREE(freepath, M_TEMP); 1587 break; 1588 } 1589 1590 /* 1591 * PMCs are not inherited across an exec(): remove any 1592 * PMCs that this process is the owner of. 1593 */ 1594 1595 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 1596 pmc_remove_owner(po); 1597 pmc_destroy_owner_descriptor(po); 1598 } 1599 1600 /* 1601 * If the process being exec'ed is not the target of any 1602 * PMC, we are done. 1603 */ 1604 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) { 1605 if (freepath) 1606 FREE(freepath, M_TEMP); 1607 break; 1608 } 1609 1610 /* 1611 * Log the exec event to all monitoring owners. Skip 1612 * owners who have already recieved the event because 1613 * they had system sampling PMCs active. 1614 */ 1615 for (ri = 0; ri < md->pmd_npmc; ri++) 1616 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 1617 po = pm->pm_owner; 1618 if (po->po_sscount == 0 && 1619 po->po_flags & PMC_PO_OWNS_LOGFILE) 1620 pmclog_process_procexec(po, pm->pm_id, 1621 p->p_pid, pk->pm_entryaddr, 1622 fullpath); 1623 } 1624 1625 if (freepath) 1626 FREE(freepath, M_TEMP); 1627 1628 1629 PMCDBG(PRC,EXC,1, "exec proc=%p (%d, %s) cred-changed=%d", 1630 p, p->p_pid, p->p_comm, pk->pm_credentialschanged); 1631 1632 if (pk->pm_credentialschanged == 0) /* no change */ 1633 break; 1634 1635 /* 1636 * If the newly exec()'ed process has a different credential 1637 * than before, allow it to be the target of a PMC only if 1638 * the PMC's owner has sufficient priviledge. 1639 */ 1640 1641 for (ri = 0; ri < md->pmd_npmc; ri++) 1642 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) 1643 if (pmc_can_attach(pm, td->td_proc) != 0) 1644 pmc_detach_one_process(td->td_proc, 1645 pm, PMC_FLAG_NONE); 1646 1647 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt < (int) md->pmd_npmc, 1648 ("[pmc,%d] Illegal ref count %d on pp %p", __LINE__, 1649 pp->pp_refcnt, pp)); 1650 1651 /* 1652 * If this process is no longer the target of any 1653 * PMCs, we can remove the process entry and free 1654 * up space. 1655 */ 1656 1657 if (pp->pp_refcnt == 0) { 1658 pmc_remove_process_descriptor(pp); 1659 FREE(pp, M_PMC); 1660 break; 1661 } 1662 1663 } 1664 break; 1665 1666 case PMC_FN_CSW_IN: 1667 pmc_process_csw_in(td); 1668 break; 1669 1670 case PMC_FN_CSW_OUT: 1671 pmc_process_csw_out(td); 1672 break; 1673 1674 /* 1675 * Process accumulated PC samples. 1676 * 1677 * This function is expected to be called by hardclock() for 1678 * each CPU that has accumulated PC samples. 1679 * 1680 * This function is to be executed on the CPU whose samples 1681 * are being processed. 1682 */ 1683 case PMC_FN_DO_SAMPLES: 1684 1685 /* 1686 * Clear the cpu specific bit in the CPU mask before 1687 * do the rest of the processing. If the NMI handler 1688 * gets invoked after the "atomic_clear_int()" call 1689 * below but before "pmc_process_samples()" gets 1690 * around to processing the interrupt, then we will 1691 * come back here at the next hardclock() tick (and 1692 * may find nothing to do if "pmc_process_samples()" 1693 * had already processed the interrupt). We don't 1694 * lose the interrupt sample. 1695 */ 1696 atomic_clear_int(&pmc_cpumask, (1 << PCPU_GET(cpuid))); 1697 pmc_process_samples(PCPU_GET(cpuid)); 1698 break; 1699 1700 1701 case PMC_FN_KLD_LOAD: 1702 sx_assert(&pmc_sx, SX_LOCKED); 1703 pmc_process_kld_load((struct pmckern_map_in *) arg); 1704 break; 1705 1706 case PMC_FN_KLD_UNLOAD: 1707 sx_assert(&pmc_sx, SX_LOCKED); 1708 pmc_process_kld_unload((struct pmckern_map_out *) arg); 1709 break; 1710 1711 case PMC_FN_MMAP: 1712 sx_assert(&pmc_sx, SX_LOCKED); 1713 pmc_process_mmap(td, (struct pmckern_map_in *) arg); 1714 break; 1715 1716 case PMC_FN_MUNMAP: 1717 sx_assert(&pmc_sx, SX_LOCKED); 1718 pmc_process_munmap(td, (struct pmckern_map_out *) arg); 1719 break; 1720 1721 default: 1722 #ifdef DEBUG 1723 KASSERT(0, ("[pmc,%d] unknown hook %d\n", __LINE__, function)); 1724 #endif 1725 break; 1726 1727 } 1728 1729 return 0; 1730 } 1731 1732 /* 1733 * allocate a 'struct pmc_owner' descriptor in the owner hash table. 1734 */ 1735 1736 static struct pmc_owner * 1737 pmc_allocate_owner_descriptor(struct proc *p) 1738 { 1739 uint32_t hindex; 1740 struct pmc_owner *po; 1741 struct pmc_ownerhash *poh; 1742 1743 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 1744 poh = &pmc_ownerhash[hindex]; 1745 1746 /* allocate space for N pointers and one descriptor struct */ 1747 MALLOC(po, struct pmc_owner *, sizeof(struct pmc_owner), 1748 M_PMC, M_ZERO|M_WAITOK); 1749 1750 po->po_sscount = po->po_error = po->po_flags = 0; 1751 po->po_file = NULL; 1752 po->po_owner = p; 1753 po->po_kthread = NULL; 1754 LIST_INIT(&po->po_pmcs); 1755 LIST_INSERT_HEAD(poh, po, po_next); /* insert into hash table */ 1756 1757 TAILQ_INIT(&po->po_logbuffers); 1758 mtx_init(&po->po_mtx, "pmc-owner-mtx", "pmc", MTX_SPIN); 1759 1760 PMCDBG(OWN,ALL,1, "allocate-owner proc=%p (%d, %s) pmc-owner=%p", 1761 p, p->p_pid, p->p_comm, po); 1762 1763 return po; 1764 } 1765 1766 static void 1767 pmc_destroy_owner_descriptor(struct pmc_owner *po) 1768 { 1769 1770 PMCDBG(OWN,REL,1, "destroy-owner po=%p proc=%p (%d, %s)", 1771 po, po->po_owner, po->po_owner->p_pid, po->po_owner->p_comm); 1772 1773 mtx_destroy(&po->po_mtx); 1774 FREE(po, M_PMC); 1775 } 1776 1777 /* 1778 * find the descriptor corresponding to process 'p', adding or removing it 1779 * as specified by 'mode'. 1780 */ 1781 1782 static struct pmc_process * 1783 pmc_find_process_descriptor(struct proc *p, uint32_t mode) 1784 { 1785 uint32_t hindex; 1786 struct pmc_process *pp, *ppnew; 1787 struct pmc_processhash *pph; 1788 1789 hindex = PMC_HASH_PTR(p, pmc_processhashmask); 1790 pph = &pmc_processhash[hindex]; 1791 1792 ppnew = NULL; 1793 1794 /* 1795 * Pre-allocate memory in the FIND_ALLOCATE case since we 1796 * cannot call malloc(9) once we hold a spin lock. 1797 */ 1798 1799 if (mode & PMC_FLAG_ALLOCATE) { 1800 /* allocate additional space for 'n' pmc pointers */ 1801 MALLOC(ppnew, struct pmc_process *, 1802 sizeof(struct pmc_process) + md->pmd_npmc * 1803 sizeof(struct pmc_targetstate), M_PMC, M_ZERO|M_WAITOK); 1804 } 1805 1806 mtx_lock_spin(&pmc_processhash_mtx); 1807 LIST_FOREACH(pp, pph, pp_next) 1808 if (pp->pp_proc == p) 1809 break; 1810 1811 if ((mode & PMC_FLAG_REMOVE) && pp != NULL) 1812 LIST_REMOVE(pp, pp_next); 1813 1814 if ((mode & PMC_FLAG_ALLOCATE) && pp == NULL && 1815 ppnew != NULL) { 1816 ppnew->pp_proc = p; 1817 LIST_INSERT_HEAD(pph, ppnew, pp_next); 1818 pp = ppnew; 1819 ppnew = NULL; 1820 } 1821 mtx_unlock_spin(&pmc_processhash_mtx); 1822 1823 if (pp != NULL && ppnew != NULL) 1824 FREE(ppnew, M_PMC); 1825 1826 return pp; 1827 } 1828 1829 /* 1830 * remove a process descriptor from the process hash table. 1831 */ 1832 1833 static void 1834 pmc_remove_process_descriptor(struct pmc_process *pp) 1835 { 1836 KASSERT(pp->pp_refcnt == 0, 1837 ("[pmc,%d] Removing process descriptor %p with count %d", 1838 __LINE__, pp, pp->pp_refcnt)); 1839 1840 mtx_lock_spin(&pmc_processhash_mtx); 1841 LIST_REMOVE(pp, pp_next); 1842 mtx_unlock_spin(&pmc_processhash_mtx); 1843 } 1844 1845 1846 /* 1847 * find an owner descriptor corresponding to proc 'p' 1848 */ 1849 1850 static struct pmc_owner * 1851 pmc_find_owner_descriptor(struct proc *p) 1852 { 1853 uint32_t hindex; 1854 struct pmc_owner *po; 1855 struct pmc_ownerhash *poh; 1856 1857 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 1858 poh = &pmc_ownerhash[hindex]; 1859 1860 po = NULL; 1861 LIST_FOREACH(po, poh, po_next) 1862 if (po->po_owner == p) 1863 break; 1864 1865 PMCDBG(OWN,FND,1, "find-owner proc=%p (%d, %s) hindex=0x%x -> " 1866 "pmc-owner=%p", p, p->p_pid, p->p_comm, hindex, po); 1867 1868 return po; 1869 } 1870 1871 /* 1872 * pmc_allocate_pmc_descriptor 1873 * 1874 * Allocate a pmc descriptor and initialize its 1875 * fields. 1876 */ 1877 1878 static struct pmc * 1879 pmc_allocate_pmc_descriptor(void) 1880 { 1881 struct pmc *pmc; 1882 1883 MALLOC(pmc, struct pmc *, sizeof(struct pmc), M_PMC, M_ZERO|M_WAITOK); 1884 1885 if (pmc != NULL) { 1886 pmc->pm_owner = NULL; 1887 LIST_INIT(&pmc->pm_targets); 1888 } 1889 1890 PMCDBG(PMC,ALL,1, "allocate-pmc -> pmc=%p", pmc); 1891 1892 return pmc; 1893 } 1894 1895 /* 1896 * Destroy a pmc descriptor. 1897 */ 1898 1899 static void 1900 pmc_destroy_pmc_descriptor(struct pmc *pm) 1901 { 1902 (void) pm; 1903 1904 #ifdef DEBUG 1905 KASSERT(pm->pm_state == PMC_STATE_DELETED || 1906 pm->pm_state == PMC_STATE_FREE, 1907 ("[pmc,%d] destroying non-deleted PMC", __LINE__)); 1908 KASSERT(LIST_EMPTY(&pm->pm_targets), 1909 ("[pmc,%d] destroying pmc with targets", __LINE__)); 1910 KASSERT(pm->pm_owner == NULL, 1911 ("[pmc,%d] destroying pmc attached to an owner", __LINE__)); 1912 KASSERT(pm->pm_runcount == 0, 1913 ("[pmc,%d] pmc has non-zero run count %d", __LINE__, 1914 pm->pm_runcount)); 1915 #endif 1916 } 1917 1918 static void 1919 pmc_wait_for_pmc_idle(struct pmc *pm) 1920 { 1921 #ifdef DEBUG 1922 volatile int maxloop; 1923 1924 maxloop = 100 * mp_ncpus; 1925 #endif 1926 1927 /* 1928 * Loop (with a forced context switch) till the PMC's runcount 1929 * comes down to zero. 1930 */ 1931 while (atomic_load_acq_32(&pm->pm_runcount) > 0) { 1932 #ifdef DEBUG 1933 maxloop--; 1934 KASSERT(maxloop > 0, 1935 ("[pmc,%d] (ri%d, rc%d) waiting too long for " 1936 "pmc to be free", __LINE__, 1937 PMC_TO_ROWINDEX(pm), pm->pm_runcount)); 1938 #endif 1939 pmc_force_context_switch(); 1940 } 1941 } 1942 1943 /* 1944 * This function does the following things: 1945 * 1946 * - detaches the PMC from hardware 1947 * - unlinks all target threads that were attached to it 1948 * - removes the PMC from its owner's list 1949 * - destroy's the PMC private mutex 1950 * 1951 * Once this function completes, the given pmc pointer can be safely 1952 * FREE'd by the caller. 1953 */ 1954 1955 static void 1956 pmc_release_pmc_descriptor(struct pmc *pm) 1957 { 1958 u_int ri, cpu; 1959 enum pmc_mode mode; 1960 struct pmc_hw *phw; 1961 struct pmc_owner *po; 1962 struct pmc_process *pp; 1963 struct pmc_target *ptgt, *tmp; 1964 struct pmc_binding pb; 1965 1966 sx_assert(&pmc_sx, SX_XLOCKED); 1967 1968 KASSERT(pm, ("[pmc,%d] null pmc", __LINE__)); 1969 1970 ri = PMC_TO_ROWINDEX(pm); 1971 mode = PMC_TO_MODE(pm); 1972 1973 PMCDBG(PMC,REL,1, "release-pmc pmc=%p ri=%d mode=%d", pm, ri, 1974 mode); 1975 1976 /* 1977 * First, we take the PMC off hardware. 1978 */ 1979 cpu = 0; 1980 if (PMC_IS_SYSTEM_MODE(mode)) { 1981 1982 /* 1983 * A system mode PMC runs on a specific CPU. Switch 1984 * to this CPU and turn hardware off. 1985 */ 1986 pmc_save_cpu_binding(&pb); 1987 1988 cpu = PMC_TO_CPU(pm); 1989 1990 pmc_select_cpu(cpu); 1991 1992 /* switch off non-stalled CPUs */ 1993 if (pm->pm_state == PMC_STATE_RUNNING && 1994 pm->pm_stalled == 0) { 1995 1996 phw = pmc_pcpu[cpu]->pc_hwpmcs[ri]; 1997 1998 KASSERT(phw->phw_pmc == pm, 1999 ("[pmc, %d] pmc ptr ri(%d) hw(%p) pm(%p)", 2000 __LINE__, ri, phw->phw_pmc, pm)); 2001 PMCDBG(PMC,REL,2, "stopping cpu=%d ri=%d", cpu, ri); 2002 2003 critical_enter(); 2004 md->pmd_stop_pmc(cpu, ri); 2005 critical_exit(); 2006 } 2007 2008 PMCDBG(PMC,REL,2, "decfg cpu=%d ri=%d", cpu, ri); 2009 2010 critical_enter(); 2011 md->pmd_config_pmc(cpu, ri, NULL); 2012 critical_exit(); 2013 2014 /* adjust the global and process count of SS mode PMCs */ 2015 if (mode == PMC_MODE_SS && pm->pm_state == PMC_STATE_RUNNING) { 2016 po = pm->pm_owner; 2017 po->po_sscount--; 2018 if (po->po_sscount == 0) { 2019 atomic_subtract_rel_int(&pmc_ss_count, 1); 2020 LIST_REMOVE(po, po_ssnext); 2021 } 2022 } 2023 2024 pm->pm_state = PMC_STATE_DELETED; 2025 2026 pmc_restore_cpu_binding(&pb); 2027 2028 /* 2029 * We could have references to this PMC structure in 2030 * the per-cpu sample queues. Wait for the queue to 2031 * drain. 2032 */ 2033 pmc_wait_for_pmc_idle(pm); 2034 2035 } else if (PMC_IS_VIRTUAL_MODE(mode)) { 2036 2037 /* 2038 * A virtual PMC could be running on multiple CPUs at 2039 * a given instant. 2040 * 2041 * By marking its state as DELETED, we ensure that 2042 * this PMC is never further scheduled on hardware. 2043 * 2044 * Then we wait till all CPUs are done with this PMC. 2045 */ 2046 pm->pm_state = PMC_STATE_DELETED; 2047 2048 2049 /* Wait for the PMCs runcount to come to zero. */ 2050 pmc_wait_for_pmc_idle(pm); 2051 2052 /* 2053 * At this point the PMC is off all CPUs and cannot be 2054 * freshly scheduled onto a CPU. It is now safe to 2055 * unlink all targets from this PMC. If a 2056 * process-record's refcount falls to zero, we remove 2057 * it from the hash table. The module-wide SX lock 2058 * protects us from races. 2059 */ 2060 LIST_FOREACH_SAFE(ptgt, &pm->pm_targets, pt_next, tmp) { 2061 pp = ptgt->pt_process; 2062 pmc_unlink_target_process(pm, pp); /* frees 'ptgt' */ 2063 2064 PMCDBG(PMC,REL,3, "pp->refcnt=%d", pp->pp_refcnt); 2065 2066 /* 2067 * If the target process record shows that no 2068 * PMCs are attached to it, reclaim its space. 2069 */ 2070 2071 if (pp->pp_refcnt == 0) { 2072 pmc_remove_process_descriptor(pp); 2073 FREE(pp, M_PMC); 2074 } 2075 } 2076 2077 cpu = curthread->td_oncpu; /* setup cpu for pmd_release() */ 2078 2079 } 2080 2081 /* 2082 * Release any MD resources 2083 */ 2084 2085 (void) md->pmd_release_pmc(cpu, ri, pm); 2086 2087 /* 2088 * Update row disposition 2089 */ 2090 2091 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) 2092 PMC_UNMARK_ROW_STANDALONE(ri); 2093 else 2094 PMC_UNMARK_ROW_THREAD(ri); 2095 2096 /* unlink from the owner's list */ 2097 if (pm->pm_owner) { 2098 LIST_REMOVE(pm, pm_next); 2099 pm->pm_owner = NULL; 2100 } 2101 2102 pmc_destroy_pmc_descriptor(pm); 2103 } 2104 2105 /* 2106 * Register an owner and a pmc. 2107 */ 2108 2109 static int 2110 pmc_register_owner(struct proc *p, struct pmc *pmc) 2111 { 2112 struct pmc_owner *po; 2113 2114 sx_assert(&pmc_sx, SX_XLOCKED); 2115 2116 if ((po = pmc_find_owner_descriptor(p)) == NULL) 2117 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) 2118 return ENOMEM; 2119 2120 KASSERT(pmc->pm_owner == NULL, 2121 ("[pmc,%d] attempting to own an initialized PMC", __LINE__)); 2122 pmc->pm_owner = po; 2123 2124 LIST_INSERT_HEAD(&po->po_pmcs, pmc, pm_next); 2125 2126 PROC_LOCK(p); 2127 p->p_flag |= P_HWPMC; 2128 PROC_UNLOCK(p); 2129 2130 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 2131 pmclog_process_pmcallocate(pmc); 2132 2133 PMCDBG(PMC,REG,1, "register-owner pmc-owner=%p pmc=%p", 2134 po, pmc); 2135 2136 return 0; 2137 } 2138 2139 /* 2140 * Return the current row disposition: 2141 * == 0 => FREE 2142 * > 0 => PROCESS MODE 2143 * < 0 => SYSTEM MODE 2144 */ 2145 2146 int 2147 pmc_getrowdisp(int ri) 2148 { 2149 return pmc_pmcdisp[ri]; 2150 } 2151 2152 /* 2153 * Check if a PMC at row index 'ri' can be allocated to the current 2154 * process. 2155 * 2156 * Allocation can fail if: 2157 * - the current process is already being profiled by a PMC at index 'ri', 2158 * attached to it via OP_PMCATTACH. 2159 * - the current process has already allocated a PMC at index 'ri' 2160 * via OP_ALLOCATE. 2161 */ 2162 2163 static int 2164 pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, int cpu) 2165 { 2166 enum pmc_mode mode; 2167 struct pmc *pm; 2168 struct pmc_owner *po; 2169 struct pmc_process *pp; 2170 2171 PMCDBG(PMC,ALR,1, "can-allocate-rowindex proc=%p (%d, %s) ri=%d " 2172 "cpu=%d", p, p->p_pid, p->p_comm, ri, cpu); 2173 2174 /* 2175 * We shouldn't have already allocated a process-mode PMC at 2176 * row index 'ri'. 2177 * 2178 * We shouldn't have allocated a system-wide PMC on the same 2179 * CPU and same RI. 2180 */ 2181 if ((po = pmc_find_owner_descriptor(p)) != NULL) 2182 LIST_FOREACH(pm, &po->po_pmcs, pm_next) { 2183 if (PMC_TO_ROWINDEX(pm) == ri) { 2184 mode = PMC_TO_MODE(pm); 2185 if (PMC_IS_VIRTUAL_MODE(mode)) 2186 return EEXIST; 2187 if (PMC_IS_SYSTEM_MODE(mode) && 2188 (int) PMC_TO_CPU(pm) == cpu) 2189 return EEXIST; 2190 } 2191 } 2192 2193 /* 2194 * We also shouldn't be the target of any PMC at this index 2195 * since otherwise a PMC_ATTACH to ourselves will fail. 2196 */ 2197 if ((pp = pmc_find_process_descriptor(p, 0)) != NULL) 2198 if (pp->pp_pmcs[ri].pp_pmc) 2199 return EEXIST; 2200 2201 PMCDBG(PMC,ALR,2, "can-allocate-rowindex proc=%p (%d, %s) ri=%d ok", 2202 p, p->p_pid, p->p_comm, ri); 2203 2204 return 0; 2205 } 2206 2207 /* 2208 * Check if a given PMC at row index 'ri' can be currently used in 2209 * mode 'mode'. 2210 */ 2211 2212 static int 2213 pmc_can_allocate_row(int ri, enum pmc_mode mode) 2214 { 2215 enum pmc_disp disp; 2216 2217 sx_assert(&pmc_sx, SX_XLOCKED); 2218 2219 PMCDBG(PMC,ALR,1, "can-allocate-row ri=%d mode=%d", ri, mode); 2220 2221 if (PMC_IS_SYSTEM_MODE(mode)) 2222 disp = PMC_DISP_STANDALONE; 2223 else 2224 disp = PMC_DISP_THREAD; 2225 2226 /* 2227 * check disposition for PMC row 'ri': 2228 * 2229 * Expected disposition Row-disposition Result 2230 * 2231 * STANDALONE STANDALONE or FREE proceed 2232 * STANDALONE THREAD fail 2233 * THREAD THREAD or FREE proceed 2234 * THREAD STANDALONE fail 2235 */ 2236 2237 if (!PMC_ROW_DISP_IS_FREE(ri) && 2238 !(disp == PMC_DISP_THREAD && PMC_ROW_DISP_IS_THREAD(ri)) && 2239 !(disp == PMC_DISP_STANDALONE && PMC_ROW_DISP_IS_STANDALONE(ri))) 2240 return EBUSY; 2241 2242 /* 2243 * All OK 2244 */ 2245 2246 PMCDBG(PMC,ALR,2, "can-allocate-row ri=%d mode=%d ok", ri, mode); 2247 2248 return 0; 2249 2250 } 2251 2252 /* 2253 * Find a PMC descriptor with user handle 'pmcid' for thread 'td'. 2254 */ 2255 2256 static struct pmc * 2257 pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, pmc_id_t pmcid) 2258 { 2259 struct pmc *pm; 2260 2261 KASSERT(PMC_ID_TO_ROWINDEX(pmcid) < md->pmd_npmc, 2262 ("[pmc,%d] Illegal pmc index %d (max %d)", __LINE__, 2263 PMC_ID_TO_ROWINDEX(pmcid), md->pmd_npmc)); 2264 2265 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 2266 if (pm->pm_id == pmcid) 2267 return pm; 2268 2269 return NULL; 2270 } 2271 2272 static int 2273 pmc_find_pmc(pmc_id_t pmcid, struct pmc **pmc) 2274 { 2275 2276 struct pmc *pm; 2277 struct pmc_owner *po; 2278 2279 PMCDBG(PMC,FND,1, "find-pmc id=%d", pmcid); 2280 2281 if ((po = pmc_find_owner_descriptor(curthread->td_proc)) == NULL) 2282 return ESRCH; 2283 2284 if ((pm = pmc_find_pmc_descriptor_in_process(po, pmcid)) == NULL) 2285 return EINVAL; 2286 2287 PMCDBG(PMC,FND,2, "find-pmc id=%d -> pmc=%p", pmcid, pm); 2288 2289 *pmc = pm; 2290 return 0; 2291 } 2292 2293 /* 2294 * Start a PMC. 2295 */ 2296 2297 static int 2298 pmc_start(struct pmc *pm) 2299 { 2300 int error, cpu, ri; 2301 enum pmc_mode mode; 2302 struct pmc_owner *po; 2303 struct pmc_binding pb; 2304 2305 KASSERT(pm != NULL, 2306 ("[pmc,%d] null pm", __LINE__)); 2307 2308 mode = PMC_TO_MODE(pm); 2309 ri = PMC_TO_ROWINDEX(pm); 2310 error = 0; 2311 2312 PMCDBG(PMC,OPS,1, "start pmc=%p mode=%d ri=%d", pm, mode, ri); 2313 2314 po = pm->pm_owner; 2315 2316 if (PMC_IS_VIRTUAL_MODE(mode)) { 2317 2318 /* 2319 * If a PMCATTACH has never been done on this PMC, 2320 * attach it to its owner process. 2321 */ 2322 2323 if (LIST_EMPTY(&pm->pm_targets)) 2324 error = (pm->pm_flags & PMC_F_ATTACH_DONE) ? ESRCH : 2325 pmc_attach_process(po->po_owner, pm); 2326 2327 /* 2328 * Disallow PMCSTART if a logfile is required but has not 2329 * been configured yet. 2330 */ 2331 2332 if (error == 0 && (pm->pm_flags & PMC_F_NEEDS_LOGFILE) && 2333 (po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) 2334 error = EDOOFUS; 2335 2336 /* 2337 * If the PMC is attached to its owner, then force a context 2338 * switch to ensure that the MD state gets set correctly. 2339 */ 2340 2341 if (error == 0) { 2342 pm->pm_state = PMC_STATE_RUNNING; 2343 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) 2344 pmc_force_context_switch(); 2345 } 2346 2347 return error; 2348 } 2349 2350 2351 /* 2352 * A system-wide PMC. 2353 */ 2354 2355 if ((pm->pm_flags & PMC_F_NEEDS_LOGFILE) && 2356 (po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) 2357 return EDOOFUS; /* programming error */ 2358 2359 /* 2360 * Add the owner to the global list if this is a system-wide 2361 * sampling PMC. 2362 */ 2363 2364 if (mode == PMC_MODE_SS) { 2365 if (po->po_sscount == 0) { 2366 LIST_INSERT_HEAD(&pmc_ss_owners, po, po_ssnext); 2367 atomic_add_rel_int(&pmc_ss_count, 1); 2368 PMCDBG(PMC,OPS,1, "po=%p in global list", po); 2369 } 2370 po->po_sscount++; 2371 } 2372 2373 /* TODO: dump system wide process mappings to the log? */ 2374 2375 /* 2376 * Move to the CPU associated with this 2377 * PMC, and start the hardware. 2378 */ 2379 2380 pmc_save_cpu_binding(&pb); 2381 2382 cpu = PMC_TO_CPU(pm); 2383 2384 if (pmc_cpu_is_disabled(cpu)) 2385 return ENXIO; 2386 2387 pmc_select_cpu(cpu); 2388 2389 /* 2390 * global PMCs are configured at allocation time 2391 * so write out the initial value and start the PMC. 2392 */ 2393 2394 pm->pm_state = PMC_STATE_RUNNING; 2395 2396 critical_enter(); 2397 if ((error = md->pmd_write_pmc(cpu, ri, 2398 PMC_IS_SAMPLING_MODE(mode) ? 2399 pm->pm_sc.pm_reloadcount : 2400 pm->pm_sc.pm_initial)) == 0) 2401 error = md->pmd_start_pmc(cpu, ri); 2402 critical_exit(); 2403 2404 pmc_restore_cpu_binding(&pb); 2405 2406 return error; 2407 } 2408 2409 /* 2410 * Stop a PMC. 2411 */ 2412 2413 static int 2414 pmc_stop(struct pmc *pm) 2415 { 2416 int cpu, error, ri; 2417 struct pmc_owner *po; 2418 struct pmc_binding pb; 2419 2420 KASSERT(pm != NULL, ("[pmc,%d] null pmc", __LINE__)); 2421 2422 PMCDBG(PMC,OPS,1, "stop pmc=%p mode=%d ri=%d", pm, 2423 PMC_TO_MODE(pm), PMC_TO_ROWINDEX(pm)); 2424 2425 pm->pm_state = PMC_STATE_STOPPED; 2426 2427 /* 2428 * If the PMC is a virtual mode one, changing the state to 2429 * non-RUNNING is enough to ensure that the PMC never gets 2430 * scheduled. 2431 * 2432 * If this PMC is current running on a CPU, then it will 2433 * handled correctly at the time its target process is context 2434 * switched out. 2435 */ 2436 2437 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 2438 return 0; 2439 2440 /* 2441 * A system-mode PMC. Move to the CPU associated with 2442 * this PMC, and stop the hardware. We update the 2443 * 'initial count' so that a subsequent PMCSTART will 2444 * resume counting from the current hardware count. 2445 */ 2446 2447 pmc_save_cpu_binding(&pb); 2448 2449 cpu = PMC_TO_CPU(pm); 2450 2451 KASSERT(cpu >= 0 && cpu < mp_ncpus, 2452 ("[pmc,%d] illegal cpu=%d", __LINE__, cpu)); 2453 2454 if (pmc_cpu_is_disabled(cpu)) 2455 return ENXIO; 2456 2457 pmc_select_cpu(cpu); 2458 2459 ri = PMC_TO_ROWINDEX(pm); 2460 2461 critical_enter(); 2462 if ((error = md->pmd_stop_pmc(cpu, ri)) == 0) 2463 error = md->pmd_read_pmc(cpu, ri, &pm->pm_sc.pm_initial); 2464 critical_exit(); 2465 2466 pmc_restore_cpu_binding(&pb); 2467 2468 po = pm->pm_owner; 2469 2470 /* remove this owner from the global list of SS PMC owners */ 2471 if (PMC_TO_MODE(pm) == PMC_MODE_SS) { 2472 po->po_sscount--; 2473 if (po->po_sscount == 0) { 2474 atomic_subtract_rel_int(&pmc_ss_count, 1); 2475 LIST_REMOVE(po, po_ssnext); 2476 PMCDBG(PMC,OPS,2,"po=%p removed from global list", po); 2477 } 2478 } 2479 2480 return error; 2481 } 2482 2483 2484 #ifdef DEBUG 2485 static const char *pmc_op_to_name[] = { 2486 #undef __PMC_OP 2487 #define __PMC_OP(N, D) #N , 2488 __PMC_OPS() 2489 NULL 2490 }; 2491 #endif 2492 2493 /* 2494 * The syscall interface 2495 */ 2496 2497 #define PMC_GET_SX_XLOCK(...) do { \ 2498 sx_xlock(&pmc_sx); \ 2499 if (pmc_hook == NULL) { \ 2500 sx_xunlock(&pmc_sx); \ 2501 return __VA_ARGS__; \ 2502 } \ 2503 } while (0) 2504 2505 #define PMC_DOWNGRADE_SX() do { \ 2506 sx_downgrade(&pmc_sx); \ 2507 is_sx_downgraded = 1; \ 2508 } while (0) 2509 2510 static int 2511 pmc_syscall_handler(struct thread *td, void *syscall_args) 2512 { 2513 int error, is_sx_downgraded, op; 2514 struct pmc_syscall_args *c; 2515 void *arg; 2516 2517 PMC_GET_SX_XLOCK(ENOSYS); 2518 2519 DROP_GIANT(); 2520 2521 is_sx_downgraded = 0; 2522 2523 c = (struct pmc_syscall_args *) syscall_args; 2524 2525 op = c->pmop_code; 2526 arg = c->pmop_data; 2527 2528 PMCDBG(MOD,PMS,1, "syscall op=%d \"%s\" arg=%p", op, 2529 pmc_op_to_name[op], arg); 2530 2531 error = 0; 2532 atomic_add_int(&pmc_stats.pm_syscalls, 1); 2533 2534 switch(op) 2535 { 2536 2537 2538 /* 2539 * Configure a log file. 2540 * 2541 * XXX This OP will be reworked. 2542 */ 2543 2544 case PMC_OP_CONFIGURELOG: 2545 { 2546 struct proc *p; 2547 struct pmc *pm; 2548 struct pmc_owner *po; 2549 struct pmckern_map_in *km, *kmbase; 2550 struct pmc_op_configurelog cl; 2551 2552 sx_assert(&pmc_sx, SX_XLOCKED); 2553 2554 if ((error = copyin(arg, &cl, sizeof(cl))) != 0) 2555 break; 2556 2557 /* mark this process as owning a log file */ 2558 p = td->td_proc; 2559 if ((po = pmc_find_owner_descriptor(p)) == NULL) 2560 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) { 2561 error = ENOMEM; 2562 break; 2563 } 2564 2565 /* 2566 * If a valid fd was passed in, try to configure that, 2567 * otherwise if 'fd' was less than zero and there was 2568 * a log file configured, flush its buffers and 2569 * de-configure it. 2570 */ 2571 if (cl.pm_logfd >= 0) 2572 error = pmclog_configure_log(po, cl.pm_logfd); 2573 else if (po->po_flags & PMC_PO_OWNS_LOGFILE) { 2574 pmclog_process_closelog(po); 2575 error = pmclog_flush(po); 2576 if (error == 0) { 2577 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 2578 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 2579 pm->pm_state == PMC_STATE_RUNNING) 2580 pmc_stop(pm); 2581 error = pmclog_deconfigure_log(po); 2582 } 2583 } else 2584 error = EINVAL; 2585 2586 if (error) 2587 break; 2588 2589 /* 2590 * Log the current set of kernel modules. 2591 */ 2592 kmbase = linker_hwpmc_list_objects(); 2593 for (km = kmbase; km->pm_file != NULL; km++) { 2594 PMCDBG(LOG,REG,1,"%s %p", (char *) km->pm_file, 2595 (void *) km->pm_address); 2596 pmclog_process_map_in(po, (pid_t) -1, km->pm_address, 2597 km->pm_file); 2598 } 2599 FREE(kmbase, M_LINKER); 2600 } 2601 break; 2602 2603 2604 /* 2605 * Flush a log file. 2606 */ 2607 2608 case PMC_OP_FLUSHLOG: 2609 { 2610 struct pmc_owner *po; 2611 2612 sx_assert(&pmc_sx, SX_XLOCKED); 2613 2614 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 2615 error = EINVAL; 2616 break; 2617 } 2618 2619 error = pmclog_flush(po); 2620 } 2621 break; 2622 2623 /* 2624 * Retrieve hardware configuration. 2625 */ 2626 2627 case PMC_OP_GETCPUINFO: /* CPU information */ 2628 { 2629 struct pmc_op_getcpuinfo gci; 2630 2631 gci.pm_cputype = md->pmd_cputype; 2632 gci.pm_ncpu = mp_ncpus; 2633 gci.pm_npmc = md->pmd_npmc; 2634 gci.pm_nclass = md->pmd_nclass; 2635 bcopy(md->pmd_classes, &gci.pm_classes, 2636 sizeof(gci.pm_classes)); 2637 error = copyout(&gci, arg, sizeof(gci)); 2638 } 2639 break; 2640 2641 2642 /* 2643 * Get module statistics 2644 */ 2645 2646 case PMC_OP_GETDRIVERSTATS: 2647 { 2648 struct pmc_op_getdriverstats gms; 2649 2650 bcopy(&pmc_stats, &gms, sizeof(gms)); 2651 error = copyout(&gms, arg, sizeof(gms)); 2652 } 2653 break; 2654 2655 2656 /* 2657 * Retrieve module version number 2658 */ 2659 2660 case PMC_OP_GETMODULEVERSION: 2661 { 2662 uint32_t cv, modv; 2663 2664 /* retrieve the client's idea of the ABI version */ 2665 if ((error = copyin(arg, &cv, sizeof(uint32_t))) != 0) 2666 break; 2667 /* don't service clients newer than our driver */ 2668 modv = PMC_VERSION; 2669 if ((cv & 0xFFFF0000) > (modv & 0xFFFF0000)) { 2670 error = EPROGMISMATCH; 2671 break; 2672 } 2673 error = copyout(&modv, arg, sizeof(int)); 2674 } 2675 break; 2676 2677 2678 /* 2679 * Retrieve the state of all the PMCs on a given 2680 * CPU. 2681 */ 2682 2683 case PMC_OP_GETPMCINFO: 2684 { 2685 uint32_t cpu, n, npmc; 2686 size_t pmcinfo_size; 2687 struct pmc *pm; 2688 struct pmc_info *p, *pmcinfo; 2689 struct pmc_op_getpmcinfo *gpi; 2690 struct pmc_owner *po; 2691 struct pmc_binding pb; 2692 2693 PMC_DOWNGRADE_SX(); 2694 2695 gpi = (struct pmc_op_getpmcinfo *) arg; 2696 2697 if ((error = copyin(&gpi->pm_cpu, &cpu, sizeof(cpu))) != 0) 2698 break; 2699 2700 if (cpu >= (unsigned int) mp_ncpus) { 2701 error = EINVAL; 2702 break; 2703 } 2704 2705 if (pmc_cpu_is_disabled(cpu)) { 2706 error = ENXIO; 2707 break; 2708 } 2709 2710 /* switch to CPU 'cpu' */ 2711 pmc_save_cpu_binding(&pb); 2712 pmc_select_cpu(cpu); 2713 2714 npmc = md->pmd_npmc; 2715 2716 pmcinfo_size = npmc * sizeof(struct pmc_info); 2717 MALLOC(pmcinfo, struct pmc_info *, pmcinfo_size, M_PMC, 2718 M_WAITOK); 2719 2720 p = pmcinfo; 2721 2722 for (n = 0; n < md->pmd_npmc; n++, p++) { 2723 2724 if ((error = md->pmd_describe(cpu, n, p, &pm)) != 0) 2725 break; 2726 2727 if (PMC_ROW_DISP_IS_STANDALONE(n)) 2728 p->pm_rowdisp = PMC_DISP_STANDALONE; 2729 else if (PMC_ROW_DISP_IS_THREAD(n)) 2730 p->pm_rowdisp = PMC_DISP_THREAD; 2731 else 2732 p->pm_rowdisp = PMC_DISP_FREE; 2733 2734 p->pm_ownerpid = -1; 2735 2736 if (pm == NULL) /* no PMC associated */ 2737 continue; 2738 2739 po = pm->pm_owner; 2740 2741 KASSERT(po->po_owner != NULL, 2742 ("[pmc,%d] pmc_owner had a null proc pointer", 2743 __LINE__)); 2744 2745 p->pm_ownerpid = po->po_owner->p_pid; 2746 p->pm_mode = PMC_TO_MODE(pm); 2747 p->pm_event = pm->pm_event; 2748 p->pm_flags = pm->pm_flags; 2749 2750 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 2751 p->pm_reloadcount = 2752 pm->pm_sc.pm_reloadcount; 2753 } 2754 2755 pmc_restore_cpu_binding(&pb); 2756 2757 /* now copy out the PMC info collected */ 2758 if (error == 0) 2759 error = copyout(pmcinfo, &gpi->pm_pmcs, pmcinfo_size); 2760 2761 FREE(pmcinfo, M_PMC); 2762 } 2763 break; 2764 2765 2766 /* 2767 * Set the administrative state of a PMC. I.e. whether 2768 * the PMC is to be used or not. 2769 */ 2770 2771 case PMC_OP_PMCADMIN: 2772 { 2773 int cpu, ri; 2774 enum pmc_state request; 2775 struct pmc_cpu *pc; 2776 struct pmc_hw *phw; 2777 struct pmc_op_pmcadmin pma; 2778 struct pmc_binding pb; 2779 2780 sx_assert(&pmc_sx, SX_XLOCKED); 2781 2782 KASSERT(td == curthread, 2783 ("[pmc,%d] td != curthread", __LINE__)); 2784 2785 if (suser(td) || jailed(td->td_ucred)) { 2786 error = EPERM; 2787 break; 2788 } 2789 2790 if ((error = copyin(arg, &pma, sizeof(pma))) != 0) 2791 break; 2792 2793 cpu = pma.pm_cpu; 2794 2795 if (cpu < 0 || cpu >= mp_ncpus) { 2796 error = EINVAL; 2797 break; 2798 } 2799 2800 if (pmc_cpu_is_disabled(cpu)) { 2801 error = ENXIO; 2802 break; 2803 } 2804 2805 request = pma.pm_state; 2806 2807 if (request != PMC_STATE_DISABLED && 2808 request != PMC_STATE_FREE) { 2809 error = EINVAL; 2810 break; 2811 } 2812 2813 ri = pma.pm_pmc; /* pmc id == row index */ 2814 if (ri < 0 || ri >= (int) md->pmd_npmc) { 2815 error = EINVAL; 2816 break; 2817 } 2818 2819 /* 2820 * We can't disable a PMC with a row-index allocated 2821 * for process virtual PMCs. 2822 */ 2823 2824 if (PMC_ROW_DISP_IS_THREAD(ri) && 2825 request == PMC_STATE_DISABLED) { 2826 error = EBUSY; 2827 break; 2828 } 2829 2830 /* 2831 * otherwise, this PMC on this CPU is either free or 2832 * in system-wide mode. 2833 */ 2834 2835 pmc_save_cpu_binding(&pb); 2836 pmc_select_cpu(cpu); 2837 2838 pc = pmc_pcpu[cpu]; 2839 phw = pc->pc_hwpmcs[ri]; 2840 2841 /* 2842 * XXX do we need some kind of 'forced' disable? 2843 */ 2844 2845 if (phw->phw_pmc == NULL) { 2846 if (request == PMC_STATE_DISABLED && 2847 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED)) { 2848 phw->phw_state &= ~PMC_PHW_FLAG_IS_ENABLED; 2849 PMC_MARK_ROW_STANDALONE(ri); 2850 } else if (request == PMC_STATE_FREE && 2851 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0) { 2852 phw->phw_state |= PMC_PHW_FLAG_IS_ENABLED; 2853 PMC_UNMARK_ROW_STANDALONE(ri); 2854 } 2855 /* other cases are a no-op */ 2856 } else 2857 error = EBUSY; 2858 2859 pmc_restore_cpu_binding(&pb); 2860 } 2861 break; 2862 2863 2864 /* 2865 * Allocate a PMC. 2866 */ 2867 2868 case PMC_OP_PMCALLOCATE: 2869 { 2870 uint32_t caps; 2871 u_int cpu; 2872 int n; 2873 enum pmc_mode mode; 2874 struct pmc *pmc; 2875 struct pmc_hw *phw; 2876 struct pmc_op_pmcallocate pa; 2877 struct pmc_binding pb; 2878 2879 if ((error = copyin(arg, &pa, sizeof(pa))) != 0) 2880 break; 2881 2882 caps = pa.pm_caps; 2883 mode = pa.pm_mode; 2884 cpu = pa.pm_cpu; 2885 2886 if ((mode != PMC_MODE_SS && mode != PMC_MODE_SC && 2887 mode != PMC_MODE_TS && mode != PMC_MODE_TC) || 2888 (cpu != (u_int) PMC_CPU_ANY && cpu >= (u_int) mp_ncpus)) { 2889 error = EINVAL; 2890 break; 2891 } 2892 2893 /* 2894 * Virtual PMCs should only ask for a default CPU. 2895 * System mode PMCs need to specify a non-default CPU. 2896 */ 2897 2898 if ((PMC_IS_VIRTUAL_MODE(mode) && cpu != (u_int) PMC_CPU_ANY) || 2899 (PMC_IS_SYSTEM_MODE(mode) && cpu == (u_int) PMC_CPU_ANY)) { 2900 error = EINVAL; 2901 break; 2902 } 2903 2904 /* 2905 * Check that a disabled CPU is not being asked for. 2906 */ 2907 2908 if (PMC_IS_SYSTEM_MODE(mode) && pmc_cpu_is_disabled(cpu)) { 2909 error = ENXIO; 2910 break; 2911 } 2912 2913 /* 2914 * Refuse an allocation for a system-wide PMC if this 2915 * process has been jailed, or if this process lacks 2916 * super-user credentials and the sysctl tunable 2917 * 'security.bsd.unprivileged_syspmcs' is zero. 2918 */ 2919 2920 if (PMC_IS_SYSTEM_MODE(mode)) { 2921 if (jailed(curthread->td_ucred)) 2922 error = EPERM; 2923 else if (suser(curthread) && 2924 (pmc_unprivileged_syspmcs == 0)) 2925 error = EPERM; 2926 } 2927 2928 if (error) 2929 break; 2930 2931 /* 2932 * Look for valid values for 'pm_flags' 2933 */ 2934 2935 if ((pa.pm_flags & ~(PMC_F_DESCENDANTS | PMC_F_LOG_PROCCSW | 2936 PMC_F_LOG_PROCEXIT)) != 0) { 2937 error = EINVAL; 2938 break; 2939 } 2940 2941 /* process logging options are not allowed for system PMCs */ 2942 if (PMC_IS_SYSTEM_MODE(mode) && (pa.pm_flags & 2943 (PMC_F_LOG_PROCCSW | PMC_F_LOG_PROCEXIT))) { 2944 error = EINVAL; 2945 break; 2946 } 2947 2948 /* 2949 * All sampling mode PMCs need to be able to interrupt the 2950 * CPU. 2951 */ 2952 if (PMC_IS_SAMPLING_MODE(mode)) 2953 caps |= PMC_CAP_INTERRUPT; 2954 2955 /* A valid class specifier should have been passed in. */ 2956 for (n = 0; n < md->pmd_nclass; n++) 2957 if (md->pmd_classes[n].pm_class == pa.pm_class) 2958 break; 2959 if (n == md->pmd_nclass) { 2960 error = EINVAL; 2961 break; 2962 } 2963 2964 /* The requested PMC capabilities should be feasible. */ 2965 if ((md->pmd_classes[n].pm_caps & caps) != caps) { 2966 error = EOPNOTSUPP; 2967 break; 2968 } 2969 2970 PMCDBG(PMC,ALL,2, "event=%d caps=0x%x mode=%d cpu=%d", 2971 pa.pm_ev, caps, mode, cpu); 2972 2973 pmc = pmc_allocate_pmc_descriptor(); 2974 pmc->pm_id = PMC_ID_MAKE_ID(cpu,pa.pm_mode,pa.pm_class, 2975 PMC_ID_INVALID); 2976 pmc->pm_event = pa.pm_ev; 2977 pmc->pm_state = PMC_STATE_FREE; 2978 pmc->pm_caps = caps; 2979 pmc->pm_flags = pa.pm_flags; 2980 2981 /* switch thread to CPU 'cpu' */ 2982 pmc_save_cpu_binding(&pb); 2983 2984 #define PMC_IS_SHAREABLE_PMC(cpu, n) \ 2985 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_state & \ 2986 PMC_PHW_FLAG_IS_SHAREABLE) 2987 #define PMC_IS_UNALLOCATED(cpu, n) \ 2988 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_pmc == NULL) 2989 2990 if (PMC_IS_SYSTEM_MODE(mode)) { 2991 pmc_select_cpu(cpu); 2992 for (n = 0; n < (int) md->pmd_npmc; n++) 2993 if (pmc_can_allocate_row(n, mode) == 0 && 2994 pmc_can_allocate_rowindex( 2995 curthread->td_proc, n, cpu) == 0 && 2996 (PMC_IS_UNALLOCATED(cpu, n) || 2997 PMC_IS_SHAREABLE_PMC(cpu, n)) && 2998 md->pmd_allocate_pmc(cpu, n, pmc, 2999 &pa) == 0) 3000 break; 3001 } else { 3002 /* Process virtual mode */ 3003 for (n = 0; n < (int) md->pmd_npmc; n++) { 3004 if (pmc_can_allocate_row(n, mode) == 0 && 3005 pmc_can_allocate_rowindex( 3006 curthread->td_proc, n, 3007 PMC_CPU_ANY) == 0 && 3008 md->pmd_allocate_pmc(curthread->td_oncpu, 3009 n, pmc, &pa) == 0) 3010 break; 3011 } 3012 } 3013 3014 #undef PMC_IS_UNALLOCATED 3015 #undef PMC_IS_SHAREABLE_PMC 3016 3017 pmc_restore_cpu_binding(&pb); 3018 3019 if (n == (int) md->pmd_npmc) { 3020 pmc_destroy_pmc_descriptor(pmc); 3021 FREE(pmc, M_PMC); 3022 pmc = NULL; 3023 error = EINVAL; 3024 break; 3025 } 3026 3027 /* Fill in the correct value in the ID field */ 3028 pmc->pm_id = PMC_ID_MAKE_ID(cpu,mode,pa.pm_class,n); 3029 3030 PMCDBG(PMC,ALL,2, "ev=%d class=%d mode=%d n=%d -> pmcid=%x", 3031 pmc->pm_event, pa.pm_class, mode, n, pmc->pm_id); 3032 3033 /* Process mode PMCs with logging enabled need log files */ 3034 if (pmc->pm_flags & (PMC_F_LOG_PROCEXIT | PMC_F_LOG_PROCCSW)) 3035 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3036 3037 /* All system mode sampling PMCs require a log file */ 3038 if (PMC_IS_SAMPLING_MODE(mode) && PMC_IS_SYSTEM_MODE(mode)) 3039 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3040 3041 /* 3042 * Configure global pmc's immediately 3043 */ 3044 3045 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pmc))) { 3046 3047 pmc_save_cpu_binding(&pb); 3048 pmc_select_cpu(cpu); 3049 3050 phw = pmc_pcpu[cpu]->pc_hwpmcs[n]; 3051 3052 if ((phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0 || 3053 (error = md->pmd_config_pmc(cpu, n, pmc)) != 0) { 3054 (void) md->pmd_release_pmc(cpu, n, pmc); 3055 pmc_destroy_pmc_descriptor(pmc); 3056 FREE(pmc, M_PMC); 3057 pmc = NULL; 3058 pmc_restore_cpu_binding(&pb); 3059 error = EPERM; 3060 break; 3061 } 3062 3063 pmc_restore_cpu_binding(&pb); 3064 } 3065 3066 pmc->pm_state = PMC_STATE_ALLOCATED; 3067 3068 /* 3069 * mark row disposition 3070 */ 3071 3072 if (PMC_IS_SYSTEM_MODE(mode)) 3073 PMC_MARK_ROW_STANDALONE(n); 3074 else 3075 PMC_MARK_ROW_THREAD(n); 3076 3077 /* 3078 * Register this PMC with the current thread as its owner. 3079 */ 3080 3081 if ((error = 3082 pmc_register_owner(curthread->td_proc, pmc)) != 0) { 3083 pmc_release_pmc_descriptor(pmc); 3084 FREE(pmc, M_PMC); 3085 pmc = NULL; 3086 break; 3087 } 3088 3089 /* 3090 * Return the allocated index. 3091 */ 3092 3093 pa.pm_pmcid = pmc->pm_id; 3094 3095 error = copyout(&pa, arg, sizeof(pa)); 3096 } 3097 break; 3098 3099 3100 /* 3101 * Attach a PMC to a process. 3102 */ 3103 3104 case PMC_OP_PMCATTACH: 3105 { 3106 struct pmc *pm; 3107 struct proc *p; 3108 struct pmc_op_pmcattach a; 3109 3110 sx_assert(&pmc_sx, SX_XLOCKED); 3111 3112 if ((error = copyin(arg, &a, sizeof(a))) != 0) 3113 break; 3114 3115 if (a.pm_pid < 0) { 3116 error = EINVAL; 3117 break; 3118 } else if (a.pm_pid == 0) 3119 a.pm_pid = td->td_proc->p_pid; 3120 3121 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 3122 break; 3123 3124 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) { 3125 error = EINVAL; 3126 break; 3127 } 3128 3129 /* PMCs may be (re)attached only when allocated or stopped */ 3130 if (pm->pm_state == PMC_STATE_RUNNING) { 3131 error = EBUSY; 3132 break; 3133 } else if (pm->pm_state != PMC_STATE_ALLOCATED && 3134 pm->pm_state != PMC_STATE_STOPPED) { 3135 error = EINVAL; 3136 break; 3137 } 3138 3139 /* lookup pid */ 3140 if ((p = pfind(a.pm_pid)) == NULL) { 3141 error = ESRCH; 3142 break; 3143 } 3144 3145 /* 3146 * Ignore processes that are working on exiting. 3147 */ 3148 if (p->p_flag & P_WEXIT) { 3149 error = ESRCH; 3150 PROC_UNLOCK(p); /* pfind() returns a locked process */ 3151 break; 3152 } 3153 3154 /* 3155 * we are allowed to attach a PMC to a process if 3156 * we can debug it. 3157 */ 3158 error = p_candebug(curthread, p); 3159 3160 PROC_UNLOCK(p); 3161 3162 if (error == 0) 3163 error = pmc_attach_process(p, pm); 3164 } 3165 break; 3166 3167 3168 /* 3169 * Detach an attached PMC from a process. 3170 */ 3171 3172 case PMC_OP_PMCDETACH: 3173 { 3174 struct pmc *pm; 3175 struct proc *p; 3176 struct pmc_op_pmcattach a; 3177 3178 if ((error = copyin(arg, &a, sizeof(a))) != 0) 3179 break; 3180 3181 if (a.pm_pid < 0) { 3182 error = EINVAL; 3183 break; 3184 } else if (a.pm_pid == 0) 3185 a.pm_pid = td->td_proc->p_pid; 3186 3187 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 3188 break; 3189 3190 if ((p = pfind(a.pm_pid)) == NULL) { 3191 error = ESRCH; 3192 break; 3193 } 3194 3195 /* 3196 * Treat processes that are in the process of exiting 3197 * as if they were not present. 3198 */ 3199 3200 if (p->p_flag & P_WEXIT) 3201 error = ESRCH; 3202 3203 PROC_UNLOCK(p); /* pfind() returns a locked process */ 3204 3205 if (error == 0) 3206 error = pmc_detach_process(p, pm); 3207 } 3208 break; 3209 3210 3211 /* 3212 * Retrieve the MSR number associated with the counter 3213 * 'pmc_id'. This allows processes to directly use RDPMC 3214 * instructions to read their PMCs, without the overhead of a 3215 * system call. 3216 */ 3217 3218 case PMC_OP_PMCGETMSR: 3219 { 3220 int ri; 3221 struct pmc *pm; 3222 struct pmc_target *pt; 3223 struct pmc_op_getmsr gm; 3224 3225 PMC_DOWNGRADE_SX(); 3226 3227 /* CPU has no 'GETMSR' support */ 3228 if (md->pmd_get_msr == NULL) { 3229 error = ENOSYS; 3230 break; 3231 } 3232 3233 if ((error = copyin(arg, &gm, sizeof(gm))) != 0) 3234 break; 3235 3236 if ((error = pmc_find_pmc(gm.pm_pmcid, &pm)) != 0) 3237 break; 3238 3239 /* 3240 * The allocated PMC has to be a process virtual PMC, 3241 * i.e., of type MODE_T[CS]. Global PMCs can only be 3242 * read using the PMCREAD operation since they may be 3243 * allocated on a different CPU than the one we could 3244 * be running on at the time of the RDPMC instruction. 3245 * 3246 * The GETMSR operation is not allowed for PMCs that 3247 * are inherited across processes. 3248 */ 3249 3250 if (!PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)) || 3251 (pm->pm_flags & PMC_F_DESCENDANTS)) { 3252 error = EINVAL; 3253 break; 3254 } 3255 3256 /* 3257 * It only makes sense to use a RDPMC (or its 3258 * equivalent instruction on non-x86 architectures) on 3259 * a process that has allocated and attached a PMC to 3260 * itself. Conversely the PMC is only allowed to have 3261 * one process attached to it -- its owner. 3262 */ 3263 3264 if ((pt = LIST_FIRST(&pm->pm_targets)) == NULL || 3265 LIST_NEXT(pt, pt_next) != NULL || 3266 pt->pt_process->pp_proc != pm->pm_owner->po_owner) { 3267 error = EINVAL; 3268 break; 3269 } 3270 3271 ri = PMC_TO_ROWINDEX(pm); 3272 3273 if ((error = (*md->pmd_get_msr)(ri, &gm.pm_msr)) < 0) 3274 break; 3275 3276 if ((error = copyout(&gm, arg, sizeof(gm))) < 0) 3277 break; 3278 3279 /* 3280 * Mark our process as using MSRs. Update machine 3281 * state using a forced context switch. 3282 */ 3283 3284 pt->pt_process->pp_flags |= PMC_PP_ENABLE_MSR_ACCESS; 3285 pmc_force_context_switch(); 3286 3287 } 3288 break; 3289 3290 /* 3291 * Release an allocated PMC 3292 */ 3293 3294 case PMC_OP_PMCRELEASE: 3295 { 3296 pmc_id_t pmcid; 3297 struct pmc *pm; 3298 struct pmc_owner *po; 3299 struct pmc_op_simple sp; 3300 3301 /* 3302 * Find PMC pointer for the named PMC. 3303 * 3304 * Use pmc_release_pmc_descriptor() to switch off the 3305 * PMC, remove all its target threads, and remove the 3306 * PMC from its owner's list. 3307 * 3308 * Remove the owner record if this is the last PMC 3309 * owned. 3310 * 3311 * Free up space. 3312 */ 3313 3314 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3315 break; 3316 3317 pmcid = sp.pm_pmcid; 3318 3319 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3320 break; 3321 3322 po = pm->pm_owner; 3323 pmc_release_pmc_descriptor(pm); 3324 pmc_maybe_remove_owner(po); 3325 3326 FREE(pm, M_PMC); 3327 } 3328 break; 3329 3330 3331 /* 3332 * Read and/or write a PMC. 3333 */ 3334 3335 case PMC_OP_PMCRW: 3336 { 3337 uint32_t cpu, ri; 3338 struct pmc *pm; 3339 struct pmc_op_pmcrw *pprw; 3340 struct pmc_op_pmcrw prw; 3341 struct pmc_binding pb; 3342 pmc_value_t oldvalue; 3343 3344 PMC_DOWNGRADE_SX(); 3345 3346 if ((error = copyin(arg, &prw, sizeof(prw))) != 0) 3347 break; 3348 3349 ri = 0; 3350 PMCDBG(PMC,OPS,1, "rw id=%d flags=0x%x", prw.pm_pmcid, 3351 prw.pm_flags); 3352 3353 /* must have at least one flag set */ 3354 if ((prw.pm_flags & (PMC_F_OLDVALUE|PMC_F_NEWVALUE)) == 0) { 3355 error = EINVAL; 3356 break; 3357 } 3358 3359 /* locate pmc descriptor */ 3360 if ((error = pmc_find_pmc(prw.pm_pmcid, &pm)) != 0) 3361 break; 3362 3363 /* Can't read a PMC that hasn't been started. */ 3364 if (pm->pm_state != PMC_STATE_ALLOCATED && 3365 pm->pm_state != PMC_STATE_STOPPED && 3366 pm->pm_state != PMC_STATE_RUNNING) { 3367 error = EINVAL; 3368 break; 3369 } 3370 3371 /* writing a new value is allowed only for 'STOPPED' pmcs */ 3372 if (pm->pm_state == PMC_STATE_RUNNING && 3373 (prw.pm_flags & PMC_F_NEWVALUE)) { 3374 error = EBUSY; 3375 break; 3376 } 3377 3378 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) { 3379 3380 /* 3381 * If this PMC is attached to its owner (i.e., 3382 * the process requesting this operation) and 3383 * is running, then attempt to get an 3384 * upto-date reading from hardware for a READ. 3385 * Writes are only allowed when the PMC is 3386 * stopped, so only update the saved value 3387 * field. 3388 * 3389 * If the PMC is not running, or is not 3390 * attached to its owner, read/write to the 3391 * savedvalue field. 3392 */ 3393 3394 ri = PMC_TO_ROWINDEX(pm); 3395 3396 mtx_pool_lock_spin(pmc_mtxpool, pm); 3397 cpu = curthread->td_oncpu; 3398 3399 if (prw.pm_flags & PMC_F_OLDVALUE) { 3400 if ((pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) && 3401 (pm->pm_state == PMC_STATE_RUNNING)) 3402 error = (*md->pmd_read_pmc)(cpu, ri, 3403 &oldvalue); 3404 else 3405 oldvalue = pm->pm_gv.pm_savedvalue; 3406 } 3407 if (prw.pm_flags & PMC_F_NEWVALUE) 3408 pm->pm_gv.pm_savedvalue = prw.pm_value; 3409 3410 mtx_pool_unlock_spin(pmc_mtxpool, pm); 3411 3412 } else { /* System mode PMCs */ 3413 cpu = PMC_TO_CPU(pm); 3414 ri = PMC_TO_ROWINDEX(pm); 3415 3416 if (pmc_cpu_is_disabled(cpu)) { 3417 error = ENXIO; 3418 break; 3419 } 3420 3421 /* move this thread to CPU 'cpu' */ 3422 pmc_save_cpu_binding(&pb); 3423 pmc_select_cpu(cpu); 3424 3425 critical_enter(); 3426 /* save old value */ 3427 if (prw.pm_flags & PMC_F_OLDVALUE) 3428 if ((error = (*md->pmd_read_pmc)(cpu, ri, 3429 &oldvalue))) 3430 goto error; 3431 /* write out new value */ 3432 if (prw.pm_flags & PMC_F_NEWVALUE) 3433 error = (*md->pmd_write_pmc)(cpu, ri, 3434 prw.pm_value); 3435 error: 3436 critical_exit(); 3437 pmc_restore_cpu_binding(&pb); 3438 if (error) 3439 break; 3440 } 3441 3442 pprw = (struct pmc_op_pmcrw *) arg; 3443 3444 #ifdef DEBUG 3445 if (prw.pm_flags & PMC_F_NEWVALUE) 3446 PMCDBG(PMC,OPS,2, "rw id=%d new %jx -> old %jx", 3447 ri, prw.pm_value, oldvalue); 3448 else if (prw.pm_flags & PMC_F_OLDVALUE) 3449 PMCDBG(PMC,OPS,2, "rw id=%d -> old %jx", ri, oldvalue); 3450 #endif 3451 3452 /* return old value if requested */ 3453 if (prw.pm_flags & PMC_F_OLDVALUE) 3454 if ((error = copyout(&oldvalue, &pprw->pm_value, 3455 sizeof(prw.pm_value)))) 3456 break; 3457 3458 } 3459 break; 3460 3461 3462 /* 3463 * Set the sampling rate for a sampling mode PMC and the 3464 * initial count for a counting mode PMC. 3465 */ 3466 3467 case PMC_OP_PMCSETCOUNT: 3468 { 3469 struct pmc *pm; 3470 struct pmc_op_pmcsetcount sc; 3471 3472 PMC_DOWNGRADE_SX(); 3473 3474 if ((error = copyin(arg, &sc, sizeof(sc))) != 0) 3475 break; 3476 3477 if ((error = pmc_find_pmc(sc.pm_pmcid, &pm)) != 0) 3478 break; 3479 3480 if (pm->pm_state == PMC_STATE_RUNNING) { 3481 error = EBUSY; 3482 break; 3483 } 3484 3485 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 3486 pm->pm_sc.pm_reloadcount = sc.pm_count; 3487 else 3488 pm->pm_sc.pm_initial = sc.pm_count; 3489 } 3490 break; 3491 3492 3493 /* 3494 * Start a PMC. 3495 */ 3496 3497 case PMC_OP_PMCSTART: 3498 { 3499 pmc_id_t pmcid; 3500 struct pmc *pm; 3501 struct pmc_op_simple sp; 3502 3503 sx_assert(&pmc_sx, SX_XLOCKED); 3504 3505 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3506 break; 3507 3508 pmcid = sp.pm_pmcid; 3509 3510 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3511 break; 3512 3513 KASSERT(pmcid == pm->pm_id, 3514 ("[pmc,%d] pmcid %x != id %x", __LINE__, 3515 pm->pm_id, pmcid)); 3516 3517 if (pm->pm_state == PMC_STATE_RUNNING) /* already running */ 3518 break; 3519 else if (pm->pm_state != PMC_STATE_STOPPED && 3520 pm->pm_state != PMC_STATE_ALLOCATED) { 3521 error = EINVAL; 3522 break; 3523 } 3524 3525 error = pmc_start(pm); 3526 } 3527 break; 3528 3529 3530 /* 3531 * Stop a PMC. 3532 */ 3533 3534 case PMC_OP_PMCSTOP: 3535 { 3536 pmc_id_t pmcid; 3537 struct pmc *pm; 3538 struct pmc_op_simple sp; 3539 3540 PMC_DOWNGRADE_SX(); 3541 3542 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3543 break; 3544 3545 pmcid = sp.pm_pmcid; 3546 3547 /* 3548 * Mark the PMC as inactive and invoke the MD stop 3549 * routines if needed. 3550 */ 3551 3552 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3553 break; 3554 3555 KASSERT(pmcid == pm->pm_id, 3556 ("[pmc,%d] pmc id %x != pmcid %x", __LINE__, 3557 pm->pm_id, pmcid)); 3558 3559 if (pm->pm_state == PMC_STATE_STOPPED) /* already stopped */ 3560 break; 3561 else if (pm->pm_state != PMC_STATE_RUNNING) { 3562 error = EINVAL; 3563 break; 3564 } 3565 3566 error = pmc_stop(pm); 3567 } 3568 break; 3569 3570 3571 /* 3572 * Write a user supplied value to the log file. 3573 */ 3574 3575 case PMC_OP_WRITELOG: 3576 { 3577 struct pmc_op_writelog wl; 3578 struct pmc_owner *po; 3579 3580 PMC_DOWNGRADE_SX(); 3581 3582 if ((error = copyin(arg, &wl, sizeof(wl))) != 0) 3583 break; 3584 3585 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 3586 error = EINVAL; 3587 break; 3588 } 3589 3590 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) { 3591 error = EINVAL; 3592 break; 3593 } 3594 3595 error = pmclog_process_userlog(po, &wl); 3596 } 3597 break; 3598 3599 3600 default: 3601 error = EINVAL; 3602 break; 3603 } 3604 3605 if (is_sx_downgraded) 3606 sx_sunlock(&pmc_sx); 3607 else 3608 sx_xunlock(&pmc_sx); 3609 3610 if (error) 3611 atomic_add_int(&pmc_stats.pm_syscall_errors, 1); 3612 3613 PICKUP_GIANT(); 3614 3615 return error; 3616 } 3617 3618 /* 3619 * Helper functions 3620 */ 3621 3622 3623 /* 3624 * Interrupt processing. 3625 * 3626 * Find a free slot in the per-cpu array of PC samples and write the 3627 * current (PMC,PID,PC) triple to it. If an event was successfully 3628 * added, a bit is set in mask 'pmc_cpumask' denoting that the 3629 * DO_SAMPLES hook needs to be invoked from the clock handler. 3630 * 3631 * This function is meant to be called from an NMI handler. It cannot 3632 * use any of the locking primitives supplied by the OS. 3633 */ 3634 3635 int 3636 pmc_process_interrupt(int cpu, struct pmc *pm, uintfptr_t pc, int usermode) 3637 { 3638 int error, ri; 3639 struct thread *td; 3640 struct pmc_sample *ps; 3641 struct pmc_samplebuffer *psb; 3642 3643 error = 0; 3644 ri = PMC_TO_ROWINDEX(pm); 3645 3646 psb = pmc_pcpu[cpu]->pc_sb; 3647 3648 ps = psb->ps_write; 3649 if (ps->ps_pc) { /* in use, reader hasn't caught up */ 3650 pm->pm_stalled = 1; 3651 atomic_add_int(&pmc_stats.pm_intr_bufferfull, 1); 3652 PMCDBG(SAM,INT,1,"(spc) cpu=%d pm=%p pc=%jx um=%d wr=%d rd=%d", 3653 cpu, pm, (uint64_t) pc, usermode, 3654 (int) (psb->ps_write - psb->ps_samples), 3655 (int) (psb->ps_read - psb->ps_samples)); 3656 error = ENOMEM; 3657 goto done; 3658 } 3659 3660 /* fill in entry */ 3661 PMCDBG(SAM,INT,1,"cpu=%d pm=%p pc=%jx um=%d wr=%d rd=%d", cpu, pm, 3662 (uint64_t) pc, usermode, 3663 (int) (psb->ps_write - psb->ps_samples), 3664 (int) (psb->ps_read - psb->ps_samples)); 3665 3666 atomic_add_rel_32(&pm->pm_runcount, 1); /* hold onto PMC */ 3667 ps->ps_pmc = pm; 3668 if ((td = curthread) && td->td_proc) 3669 ps->ps_pid = td->td_proc->p_pid; 3670 else 3671 ps->ps_pid = -1; 3672 ps->ps_usermode = usermode; 3673 ps->ps_pc = pc; /* mark entry as in use */ 3674 3675 /* increment write pointer, modulo ring buffer size */ 3676 ps++; 3677 if (ps == psb->ps_fence) 3678 psb->ps_write = psb->ps_samples; 3679 else 3680 psb->ps_write = ps; 3681 3682 done: 3683 /* mark CPU as needing processing */ 3684 atomic_set_rel_int(&pmc_cpumask, (1 << cpu)); 3685 3686 return error; 3687 } 3688 3689 3690 /* 3691 * Process saved PC samples. 3692 */ 3693 3694 static void 3695 pmc_process_samples(int cpu) 3696 { 3697 int n, ri; 3698 struct pmc *pm; 3699 struct thread *td; 3700 struct pmc_owner *po; 3701 struct pmc_sample *ps; 3702 struct pmc_samplebuffer *psb; 3703 3704 KASSERT(PCPU_GET(cpuid) == cpu, 3705 ("[pmc,%d] not on the correct CPU pcpu=%d cpu=%d", __LINE__, 3706 PCPU_GET(cpuid), cpu)); 3707 3708 psb = pmc_pcpu[cpu]->pc_sb; 3709 3710 for (n = 0; n < pmc_nsamples; n++) { /* bound on #iterations */ 3711 3712 ps = psb->ps_read; 3713 if (ps->ps_pc == (uintfptr_t) 0) /* no data */ 3714 break; 3715 3716 pm = ps->ps_pmc; 3717 po = pm->pm_owner; 3718 3719 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 3720 ("[pmc,%d] pmc=%p non-sampling mode=%d", __LINE__, 3721 pm, PMC_TO_MODE(pm))); 3722 3723 /* Ignore PMCs that have been switched off */ 3724 if (pm->pm_state != PMC_STATE_RUNNING) 3725 goto entrydone; 3726 3727 PMCDBG(SAM,OPS,1,"cpu=%d pm=%p pc=%jx um=%d wr=%d rd=%d", cpu, 3728 pm, (uint64_t) ps->ps_pc, ps->ps_usermode, 3729 (int) (psb->ps_write - psb->ps_samples), 3730 (int) (psb->ps_read - psb->ps_samples)); 3731 3732 /* 3733 * If this is a process-mode PMC that is attached to 3734 * its owner, and if the PC is in user mode, update 3735 * profiling statistics like timer-based profiling 3736 * would have done. 3737 */ 3738 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) { 3739 if (ps->ps_usermode) { 3740 td = FIRST_THREAD_IN_PROC(po->po_owner); 3741 addupc_intr(td, ps->ps_pc, 1); 3742 } 3743 goto entrydone; 3744 } 3745 3746 /* 3747 * Otherwise, this is either a sampling mode PMC that 3748 * is attached to a different process than its owner, 3749 * or a system-wide sampling PMC. Dispatch a log 3750 * entry to the PMC's owner process. 3751 */ 3752 3753 pmclog_process_pcsample(pm, ps); 3754 3755 entrydone: 3756 ps->ps_pc = (uintfptr_t) 0; /* mark entry as free */ 3757 atomic_subtract_rel_32(&pm->pm_runcount, 1); 3758 3759 /* increment read pointer, modulo sample size */ 3760 if (++ps == psb->ps_fence) 3761 psb->ps_read = psb->ps_samples; 3762 else 3763 psb->ps_read = ps; 3764 } 3765 3766 atomic_add_int(&pmc_stats.pm_log_sweeps, 1); 3767 3768 /* Do not re-enable stalled PMCs if we failed to process any samples */ 3769 if (n == 0) 3770 return; 3771 3772 /* 3773 * Restart any stalled sampling PMCs on this CPU. 3774 * 3775 * If the NMI handler sets the pm_stalled field of a PMC after 3776 * the check below, we'll end up processing the stalled PMC at 3777 * the next hardclock tick. 3778 */ 3779 for (n = 0; n < md->pmd_npmc; n++) { 3780 (void) (*md->pmd_get_config)(cpu,n,&pm); 3781 if (pm == NULL || /* !cfg'ed */ 3782 pm->pm_state != PMC_STATE_RUNNING || /* !active */ 3783 !PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) || /* !sampling */ 3784 pm->pm_stalled == 0) /* !stalled */ 3785 continue; 3786 3787 pm->pm_stalled = 0; 3788 ri = PMC_TO_ROWINDEX(pm); 3789 (*md->pmd_start_pmc)(cpu, ri); 3790 } 3791 } 3792 3793 /* 3794 * Event handlers. 3795 */ 3796 3797 /* 3798 * Handle a process exit. 3799 * 3800 * Remove this process from all hash tables. If this process 3801 * owned any PMCs, turn off those PMCs and deallocate them, 3802 * removing any associations with target processes. 3803 * 3804 * This function will be called by the last 'thread' of a 3805 * process. 3806 * 3807 * XXX This eventhandler gets called early in the exit process. 3808 * Consider using a 'hook' invocation from thread_exit() or equivalent 3809 * spot. Another negative is that kse_exit doesn't seem to call 3810 * exit1() [??]. 3811 * 3812 */ 3813 3814 static void 3815 pmc_process_exit(void *arg __unused, struct proc *p) 3816 { 3817 int is_using_hwpmcs; 3818 int cpu; 3819 unsigned int ri; 3820 struct pmc *pm; 3821 struct pmc_process *pp; 3822 struct pmc_owner *po; 3823 pmc_value_t newvalue, tmp; 3824 3825 PROC_LOCK(p); 3826 is_using_hwpmcs = p->p_flag & P_HWPMC; 3827 PROC_UNLOCK(p); 3828 3829 /* 3830 * Log a sysexit event to all SS PMC owners. 3831 */ 3832 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 3833 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 3834 pmclog_process_sysexit(po, p->p_pid); 3835 3836 if (!is_using_hwpmcs) 3837 return; 3838 3839 PMC_GET_SX_XLOCK(); 3840 PMCDBG(PRC,EXT,1,"process-exit proc=%p (%d, %s)", p, p->p_pid, 3841 p->p_comm); 3842 3843 /* 3844 * Since this code is invoked by the last thread in an exiting 3845 * process, we would have context switched IN at some prior 3846 * point. However, with PREEMPTION, kernel mode context 3847 * switches may happen any time, so we want to disable a 3848 * context switch OUT till we get any PMCs targetting this 3849 * process off the hardware. 3850 * 3851 * We also need to atomically remove this process' 3852 * entry from our target process hash table, using 3853 * PMC_FLAG_REMOVE. 3854 */ 3855 PMCDBG(PRC,EXT,1, "process-exit proc=%p (%d, %s)", p, p->p_pid, 3856 p->p_comm); 3857 3858 critical_enter(); /* no preemption */ 3859 3860 cpu = curthread->td_oncpu; 3861 3862 if ((pp = pmc_find_process_descriptor(p, 3863 PMC_FLAG_REMOVE)) != NULL) { 3864 3865 PMCDBG(PRC,EXT,2, 3866 "process-exit proc=%p pmc-process=%p", p, pp); 3867 3868 /* 3869 * The exiting process could the target of 3870 * some PMCs which will be running on 3871 * currently executing CPU. 3872 * 3873 * We need to turn these PMCs off like we 3874 * would do at context switch OUT time. 3875 */ 3876 for (ri = 0; ri < md->pmd_npmc; ri++) { 3877 3878 /* 3879 * Pick up the pmc pointer from hardware 3880 * state similar to the CSW_OUT code. 3881 */ 3882 pm = NULL; 3883 (void) (*md->pmd_get_config)(cpu, ri, &pm); 3884 3885 PMCDBG(PRC,EXT,2, "ri=%d pm=%p", ri, pm); 3886 3887 if (pm == NULL || 3888 !PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 3889 continue; 3890 3891 PMCDBG(PRC,EXT,2, "ppmcs[%d]=%p pm=%p " 3892 "state=%d", ri, pp->pp_pmcs[ri].pp_pmc, 3893 pm, pm->pm_state); 3894 3895 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 3896 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 3897 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 3898 3899 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 3900 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", 3901 __LINE__, pm, ri, pp->pp_pmcs[ri].pp_pmc)); 3902 3903 (void) md->pmd_stop_pmc(cpu, ri); 3904 3905 KASSERT(pm->pm_runcount > 0, 3906 ("[pmc,%d] bad runcount ri %d rc %d", 3907 __LINE__, ri, pm->pm_runcount)); 3908 3909 /* Stop hardware only if it is actually running */ 3910 if (pm->pm_state == PMC_STATE_RUNNING && 3911 pm->pm_stalled == 0) { 3912 md->pmd_read_pmc(cpu, ri, &newvalue); 3913 tmp = newvalue - 3914 PMC_PCPU_SAVED(cpu,ri); 3915 3916 mtx_pool_lock_spin(pmc_mtxpool, pm); 3917 pm->pm_gv.pm_savedvalue += tmp; 3918 pp->pp_pmcs[ri].pp_pmcval += tmp; 3919 mtx_pool_unlock_spin(pmc_mtxpool, pm); 3920 } 3921 3922 atomic_subtract_rel_32(&pm->pm_runcount,1); 3923 3924 KASSERT((int) pm->pm_runcount >= 0, 3925 ("[pmc,%d] runcount is %d", __LINE__, ri)); 3926 3927 (void) md->pmd_config_pmc(cpu, ri, NULL); 3928 } 3929 3930 /* 3931 * Inform the MD layer of this pseudo "context switch 3932 * out" 3933 */ 3934 (void) md->pmd_switch_out(pmc_pcpu[cpu], pp); 3935 3936 critical_exit(); /* ok to be pre-empted now */ 3937 3938 /* 3939 * Unlink this process from the PMCs that are 3940 * targetting it. This will send a signal to 3941 * all PMC owner's whose PMCs are orphaned. 3942 * 3943 * Log PMC value at exit time if requested. 3944 */ 3945 for (ri = 0; ri < md->pmd_npmc; ri++) 3946 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 3947 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 3948 PMC_IS_COUNTING_MODE(PMC_TO_MODE(pm))) 3949 pmclog_process_procexit(pm, pp); 3950 pmc_unlink_target_process(pm, pp); 3951 } 3952 FREE(pp, M_PMC); 3953 3954 } else 3955 critical_exit(); /* pp == NULL */ 3956 3957 3958 /* 3959 * If the process owned PMCs, free them up and free up 3960 * memory. 3961 */ 3962 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 3963 pmc_remove_owner(po); 3964 pmc_destroy_owner_descriptor(po); 3965 } 3966 3967 sx_xunlock(&pmc_sx); 3968 } 3969 3970 /* 3971 * Handle a process fork. 3972 * 3973 * If the parent process 'p1' is under HWPMC monitoring, then copy 3974 * over any attached PMCs that have 'do_descendants' semantics. 3975 */ 3976 3977 static void 3978 pmc_process_fork(void *arg __unused, struct proc *p1, struct proc *newproc, 3979 int flags) 3980 { 3981 int is_using_hwpmcs; 3982 unsigned int ri; 3983 uint32_t do_descendants; 3984 struct pmc *pm; 3985 struct pmc_owner *po; 3986 struct pmc_process *ppnew, *ppold; 3987 3988 (void) flags; /* unused parameter */ 3989 3990 PROC_LOCK(p1); 3991 is_using_hwpmcs = p1->p_flag & P_HWPMC; 3992 PROC_UNLOCK(p1); 3993 3994 /* 3995 * If there are system-wide sampling PMCs active, we need to 3996 * log all fork events to their owner's logs. 3997 */ 3998 3999 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4000 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4001 pmclog_process_procfork(po, p1->p_pid, newproc->p_pid); 4002 4003 if (!is_using_hwpmcs) 4004 return; 4005 4006 PMC_GET_SX_XLOCK(); 4007 PMCDBG(PMC,FRK,1, "process-fork proc=%p (%d, %s) -> %p", p1, 4008 p1->p_pid, p1->p_comm, newproc); 4009 4010 /* 4011 * If the parent process (curthread->td_proc) is a 4012 * target of any PMCs, look for PMCs that are to be 4013 * inherited, and link these into the new process 4014 * descriptor. 4015 */ 4016 if ((ppold = pmc_find_process_descriptor(curthread->td_proc, 4017 PMC_FLAG_NONE)) == NULL) 4018 goto done; /* nothing to do */ 4019 4020 do_descendants = 0; 4021 for (ri = 0; ri < md->pmd_npmc; ri++) 4022 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL) 4023 do_descendants |= pm->pm_flags & PMC_F_DESCENDANTS; 4024 if (do_descendants == 0) /* nothing to do */ 4025 goto done; 4026 4027 /* allocate a descriptor for the new process */ 4028 if ((ppnew = pmc_find_process_descriptor(newproc, 4029 PMC_FLAG_ALLOCATE)) == NULL) 4030 goto done; 4031 4032 /* 4033 * Run through all PMCs that were targeting the old process 4034 * and which specified F_DESCENDANTS and attach them to the 4035 * new process. 4036 * 4037 * Log the fork event to all owners of PMCs attached to this 4038 * process, if not already logged. 4039 */ 4040 for (ri = 0; ri < md->pmd_npmc; ri++) 4041 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL && 4042 (pm->pm_flags & PMC_F_DESCENDANTS)) { 4043 pmc_link_target_process(pm, ppnew); 4044 po = pm->pm_owner; 4045 if (po->po_sscount == 0 && 4046 po->po_flags & PMC_PO_OWNS_LOGFILE) 4047 pmclog_process_procfork(po, p1->p_pid, 4048 newproc->p_pid); 4049 } 4050 4051 /* 4052 * Now mark the new process as being tracked by this driver. 4053 */ 4054 PROC_LOCK(newproc); 4055 newproc->p_flag |= P_HWPMC; 4056 PROC_UNLOCK(newproc); 4057 4058 done: 4059 sx_xunlock(&pmc_sx); 4060 } 4061 4062 4063 /* 4064 * initialization 4065 */ 4066 4067 static const char *pmc_name_of_pmcclass[] = { 4068 #undef __PMC_CLASS 4069 #define __PMC_CLASS(N) #N , 4070 __PMC_CLASSES() 4071 }; 4072 4073 static int 4074 pmc_initialize(void) 4075 { 4076 int cpu, error, n; 4077 struct pmc_binding pb; 4078 struct pmc_samplebuffer *sb; 4079 4080 md = NULL; 4081 error = 0; 4082 4083 #ifdef DEBUG 4084 /* parse debug flags first */ 4085 if (TUNABLE_STR_FETCH(PMC_SYSCTL_NAME_PREFIX "debugflags", 4086 pmc_debugstr, sizeof(pmc_debugstr))) 4087 pmc_debugflags_parse(pmc_debugstr, 4088 pmc_debugstr+strlen(pmc_debugstr)); 4089 #endif 4090 4091 PMCDBG(MOD,INI,0, "PMC Initialize (version %x)", PMC_VERSION); 4092 4093 /* check kernel version */ 4094 if (pmc_kernel_version != PMC_VERSION) { 4095 if (pmc_kernel_version == 0) 4096 printf("hwpmc: this kernel has not been compiled with " 4097 "'options HWPMC_HOOKS'.\n"); 4098 else 4099 printf("hwpmc: kernel version (0x%x) does not match " 4100 "module version (0x%x).\n", pmc_kernel_version, 4101 PMC_VERSION); 4102 return EPROGMISMATCH; 4103 } 4104 4105 /* 4106 * check sysctl parameters 4107 */ 4108 4109 if (pmc_hashsize <= 0) { 4110 (void) printf("hwpmc: tunable hashsize=%d must be greater " 4111 "than zero.\n", pmc_hashsize); 4112 pmc_hashsize = PMC_HASH_SIZE; 4113 } 4114 4115 if (pmc_nsamples <= 0 || pmc_nsamples > 65535) { 4116 (void) printf("hwpmc: tunable nsamples=%d out of range.\n", 4117 pmc_nsamples); 4118 pmc_nsamples = PMC_NSAMPLES; 4119 } 4120 4121 md = pmc_md_initialize(); 4122 4123 if (md == NULL || md->pmd_init == NULL) 4124 return ENOSYS; 4125 4126 /* allocate space for the per-cpu array */ 4127 MALLOC(pmc_pcpu, struct pmc_cpu **, mp_ncpus * sizeof(struct pmc_cpu *), 4128 M_PMC, M_WAITOK|M_ZERO); 4129 4130 /* per-cpu 'saved values' for managing process-mode PMCs */ 4131 MALLOC(pmc_pcpu_saved, pmc_value_t *, 4132 sizeof(pmc_value_t) * mp_ncpus * md->pmd_npmc, M_PMC, M_WAITOK); 4133 4134 /* perform cpu dependent initialization */ 4135 pmc_save_cpu_binding(&pb); 4136 for (cpu = 0; cpu < mp_ncpus; cpu++) { 4137 if (pmc_cpu_is_disabled(cpu)) 4138 continue; 4139 pmc_select_cpu(cpu); 4140 if ((error = md->pmd_init(cpu)) != 0) 4141 break; 4142 } 4143 pmc_restore_cpu_binding(&pb); 4144 4145 if (error != 0) 4146 return error; 4147 4148 /* allocate space for the sample array */ 4149 for (cpu = 0; cpu < mp_ncpus; cpu++) { 4150 if (pmc_cpu_is_disabled(cpu)) 4151 continue; 4152 MALLOC(sb, struct pmc_samplebuffer *, 4153 sizeof(struct pmc_samplebuffer) + 4154 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 4155 M_WAITOK|M_ZERO); 4156 4157 sb->ps_read = sb->ps_write = sb->ps_samples; 4158 sb->ps_fence = sb->ps_samples + pmc_nsamples; 4159 KASSERT(pmc_pcpu[cpu] != NULL, 4160 ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu)); 4161 4162 pmc_pcpu[cpu]->pc_sb = sb; 4163 } 4164 4165 /* allocate space for the row disposition array */ 4166 pmc_pmcdisp = malloc(sizeof(enum pmc_mode) * md->pmd_npmc, 4167 M_PMC, M_WAITOK|M_ZERO); 4168 4169 KASSERT(pmc_pmcdisp != NULL, 4170 ("[pmc,%d] pmcdisp allocation returned NULL", __LINE__)); 4171 4172 /* mark all PMCs as available */ 4173 for (n = 0; n < (int) md->pmd_npmc; n++) 4174 PMC_MARK_ROW_FREE(n); 4175 4176 /* allocate thread hash tables */ 4177 pmc_ownerhash = hashinit(pmc_hashsize, M_PMC, 4178 &pmc_ownerhashmask); 4179 4180 pmc_processhash = hashinit(pmc_hashsize, M_PMC, 4181 &pmc_processhashmask); 4182 mtx_init(&pmc_processhash_mtx, "pmc-process-hash", "pmc", MTX_SPIN); 4183 4184 LIST_INIT(&pmc_ss_owners); 4185 pmc_ss_count = 0; 4186 4187 /* allocate a pool of spin mutexes */ 4188 pmc_mtxpool = mtx_pool_create("pmc", pmc_mtxpool_size, MTX_SPIN); 4189 4190 PMCDBG(MOD,INI,1, "pmc_ownerhash=%p, mask=0x%lx " 4191 "targethash=%p mask=0x%lx", pmc_ownerhash, pmc_ownerhashmask, 4192 pmc_processhash, pmc_processhashmask); 4193 4194 /* register process {exit,fork,exec} handlers */ 4195 pmc_exit_tag = EVENTHANDLER_REGISTER(process_exit, 4196 pmc_process_exit, NULL, EVENTHANDLER_PRI_ANY); 4197 pmc_fork_tag = EVENTHANDLER_REGISTER(process_fork, 4198 pmc_process_fork, NULL, EVENTHANDLER_PRI_ANY); 4199 4200 /* initialize logging */ 4201 pmclog_initialize(); 4202 4203 /* set hook functions */ 4204 pmc_intr = md->pmd_intr; 4205 pmc_hook = pmc_hook_handler; 4206 4207 if (error == 0) { 4208 printf(PMC_MODULE_NAME ":"); 4209 for (n = 0; n < (int) md->pmd_nclass; n++) { 4210 printf(" %s/%d/0x%b", 4211 pmc_name_of_pmcclass[md->pmd_classes[n].pm_class], 4212 md->pmd_nclasspmcs[n], 4213 md->pmd_classes[n].pm_caps, 4214 "\20" 4215 "\1INT\2USR\3SYS\4EDG\5THR" 4216 "\6REA\7WRI\10INV\11QUA\12PRC" 4217 "\13TAG\14CSC"); 4218 } 4219 printf("\n"); 4220 } 4221 4222 return error; 4223 } 4224 4225 /* prepare to be unloaded */ 4226 static void 4227 pmc_cleanup(void) 4228 { 4229 int cpu; 4230 struct pmc_ownerhash *ph; 4231 struct pmc_owner *po, *tmp; 4232 struct pmc_binding pb; 4233 #ifdef DEBUG 4234 struct pmc_processhash *prh; 4235 #endif 4236 4237 PMCDBG(MOD,INI,0, "%s", "cleanup"); 4238 4239 /* switch off sampling */ 4240 atomic_store_rel_int(&pmc_cpumask, 0); 4241 pmc_intr = NULL; 4242 4243 sx_xlock(&pmc_sx); 4244 if (pmc_hook == NULL) { /* being unloaded already */ 4245 sx_xunlock(&pmc_sx); 4246 return; 4247 } 4248 4249 pmc_hook = NULL; /* prevent new threads from entering module */ 4250 4251 /* deregister event handlers */ 4252 EVENTHANDLER_DEREGISTER(process_fork, pmc_fork_tag); 4253 EVENTHANDLER_DEREGISTER(process_exit, pmc_exit_tag); 4254 4255 /* send SIGBUS to all owner threads, free up allocations */ 4256 if (pmc_ownerhash) 4257 for (ph = pmc_ownerhash; 4258 ph <= &pmc_ownerhash[pmc_ownerhashmask]; 4259 ph++) { 4260 LIST_FOREACH_SAFE(po, ph, po_next, tmp) { 4261 pmc_remove_owner(po); 4262 4263 /* send SIGBUS to owner processes */ 4264 PMCDBG(MOD,INI,2, "cleanup signal proc=%p " 4265 "(%d, %s)", po->po_owner, 4266 po->po_owner->p_pid, 4267 po->po_owner->p_comm); 4268 4269 PROC_LOCK(po->po_owner); 4270 psignal(po->po_owner, SIGBUS); 4271 PROC_UNLOCK(po->po_owner); 4272 4273 pmc_destroy_owner_descriptor(po); 4274 } 4275 } 4276 4277 /* reclaim allocated data structures */ 4278 if (pmc_mtxpool) 4279 mtx_pool_destroy(&pmc_mtxpool); 4280 4281 mtx_destroy(&pmc_processhash_mtx); 4282 if (pmc_processhash) { 4283 #ifdef DEBUG 4284 struct pmc_process *pp; 4285 4286 PMCDBG(MOD,INI,3, "%s", "destroy process hash"); 4287 for (prh = pmc_processhash; 4288 prh <= &pmc_processhash[pmc_processhashmask]; 4289 prh++) 4290 LIST_FOREACH(pp, prh, pp_next) 4291 PMCDBG(MOD,INI,3, "pid=%d", pp->pp_proc->p_pid); 4292 #endif 4293 4294 hashdestroy(pmc_processhash, M_PMC, pmc_processhashmask); 4295 pmc_processhash = NULL; 4296 } 4297 4298 if (pmc_ownerhash) { 4299 PMCDBG(MOD,INI,3, "%s", "destroy owner hash"); 4300 hashdestroy(pmc_ownerhash, M_PMC, pmc_ownerhashmask); 4301 pmc_ownerhash = NULL; 4302 } 4303 4304 KASSERT(LIST_EMPTY(&pmc_ss_owners), 4305 ("[pmc,%d] Global SS owner list not empty", __LINE__)); 4306 KASSERT(pmc_ss_count == 0, 4307 ("[pmc,%d] Global SS count not empty", __LINE__)); 4308 4309 /* free the per-cpu sample buffers */ 4310 for (cpu = 0; cpu < mp_ncpus; cpu++) { 4311 if (pmc_cpu_is_disabled(cpu)) 4312 continue; 4313 KASSERT(pmc_pcpu[cpu]->pc_sb != NULL, 4314 ("[pmc,%d] Null cpu sample buffer cpu=%d", __LINE__, 4315 cpu)); 4316 FREE(pmc_pcpu[cpu]->pc_sb, M_PMC); 4317 pmc_pcpu[cpu]->pc_sb = NULL; 4318 } 4319 4320 /* do processor dependent cleanup */ 4321 PMCDBG(MOD,INI,3, "%s", "md cleanup"); 4322 if (md) { 4323 pmc_save_cpu_binding(&pb); 4324 for (cpu = 0; cpu < mp_ncpus; cpu++) { 4325 PMCDBG(MOD,INI,1,"pmc-cleanup cpu=%d pcs=%p", 4326 cpu, pmc_pcpu[cpu]); 4327 if (pmc_cpu_is_disabled(cpu)) 4328 continue; 4329 pmc_select_cpu(cpu); 4330 if (pmc_pcpu[cpu]) 4331 (void) md->pmd_cleanup(cpu); 4332 } 4333 FREE(md, M_PMC); 4334 md = NULL; 4335 pmc_restore_cpu_binding(&pb); 4336 } 4337 4338 /* deallocate per-cpu structures */ 4339 FREE(pmc_pcpu, M_PMC); 4340 pmc_pcpu = NULL; 4341 4342 FREE(pmc_pcpu_saved, M_PMC); 4343 pmc_pcpu_saved = NULL; 4344 4345 if (pmc_pmcdisp) { 4346 FREE(pmc_pmcdisp, M_PMC); 4347 pmc_pmcdisp = NULL; 4348 } 4349 4350 pmclog_shutdown(); 4351 4352 sx_xunlock(&pmc_sx); /* we are done */ 4353 } 4354 4355 /* 4356 * The function called at load/unload. 4357 */ 4358 4359 static int 4360 load (struct module *module __unused, int cmd, void *arg __unused) 4361 { 4362 int error; 4363 4364 error = 0; 4365 4366 switch (cmd) { 4367 case MOD_LOAD : 4368 /* initialize the subsystem */ 4369 error = pmc_initialize(); 4370 if (error != 0) 4371 break; 4372 PMCDBG(MOD,INI,1, "syscall=%d ncpus=%d", 4373 pmc_syscall_num, mp_ncpus); 4374 break; 4375 4376 4377 case MOD_UNLOAD : 4378 case MOD_SHUTDOWN: 4379 pmc_cleanup(); 4380 PMCDBG(MOD,INI,1, "%s", "unloaded"); 4381 break; 4382 4383 default : 4384 error = EINVAL; /* XXX should panic(9) */ 4385 break; 4386 } 4387 4388 return error; 4389 } 4390 4391 /* memory pool */ 4392 MALLOC_DEFINE(M_PMC, "pmc", "Memory space for the PMC module"); 4393