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 SYSCTL_DECL(_security_bsd); 256 257 static int pmc_unprivileged_syspmcs = 0; 258 TUNABLE_INT("security.bsd.unprivileged_syspmcs", &pmc_unprivileged_syspmcs); 259 SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_syspmcs, CTLFLAG_RW, 260 &pmc_unprivileged_syspmcs, 0, 261 "allow unprivileged process to allocate system PMCs"); 262 263 /* 264 * Hash function. Discard the lower 2 bits of the pointer since 265 * these are always zero for our uses. The hash multiplier is 266 * round((2^LONG_BIT) * ((sqrt(5)-1)/2)). 267 */ 268 269 #if LONG_BIT == 64 270 #define _PMC_HM 11400714819323198486u 271 #elif LONG_BIT == 32 272 #define _PMC_HM 2654435769u 273 #else 274 #error Must know the size of 'long' to compile 275 #endif 276 277 #define PMC_HASH_PTR(P,M) ((((unsigned long) (P) >> 2) * _PMC_HM) & (M)) 278 279 /* 280 * Syscall structures 281 */ 282 283 /* The `sysent' for the new syscall */ 284 static struct sysent pmc_sysent = { 285 2, /* sy_narg */ 286 pmc_syscall_handler /* sy_call */ 287 }; 288 289 static struct syscall_module_data pmc_syscall_mod = { 290 load, 291 NULL, 292 &pmc_syscall_num, 293 &pmc_sysent, 294 { 0, NULL } 295 }; 296 297 static moduledata_t pmc_mod = { 298 PMC_MODULE_NAME, 299 syscall_module_handler, 300 &pmc_syscall_mod 301 }; 302 303 DECLARE_MODULE(pmc, pmc_mod, SI_SUB_SMP, SI_ORDER_ANY); 304 MODULE_VERSION(pmc, PMC_VERSION); 305 306 #ifdef DEBUG 307 enum pmc_dbgparse_state { 308 PMCDS_WS, /* in whitespace */ 309 PMCDS_MAJOR, /* seen a major keyword */ 310 PMCDS_MINOR 311 }; 312 313 static int 314 pmc_debugflags_parse(char *newstr, char *fence) 315 { 316 char c, *p, *q; 317 struct pmc_debugflags *tmpflags; 318 int error, found, *newbits, tmp; 319 size_t kwlen; 320 321 MALLOC(tmpflags, struct pmc_debugflags *, sizeof(*tmpflags), 322 M_PMC, M_WAITOK|M_ZERO); 323 324 p = newstr; 325 error = 0; 326 327 for (; p < fence && (c = *p); p++) { 328 329 /* skip white space */ 330 if (c == ' ' || c == '\t') 331 continue; 332 333 /* look for a keyword followed by "=" */ 334 for (q = p; p < fence && (c = *p) && c != '='; p++) 335 ; 336 if (c != '=') { 337 error = EINVAL; 338 goto done; 339 } 340 341 kwlen = p - q; 342 newbits = NULL; 343 344 /* lookup flag group name */ 345 #define DBG_SET_FLAG_MAJ(S,F) \ 346 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \ 347 newbits = &tmpflags->pdb_ ## F; 348 349 DBG_SET_FLAG_MAJ("cpu", CPU); 350 DBG_SET_FLAG_MAJ("csw", CSW); 351 DBG_SET_FLAG_MAJ("logging", LOG); 352 DBG_SET_FLAG_MAJ("module", MOD); 353 DBG_SET_FLAG_MAJ("md", MDP); 354 DBG_SET_FLAG_MAJ("owner", OWN); 355 DBG_SET_FLAG_MAJ("pmc", PMC); 356 DBG_SET_FLAG_MAJ("process", PRC); 357 DBG_SET_FLAG_MAJ("sampling", SAM); 358 359 if (newbits == NULL) { 360 error = EINVAL; 361 goto done; 362 } 363 364 p++; /* skip the '=' */ 365 366 /* Now parse the individual flags */ 367 tmp = 0; 368 newflag: 369 for (q = p; p < fence && (c = *p); p++) 370 if (c == ' ' || c == '\t' || c == ',') 371 break; 372 373 /* p == fence or c == ws or c == "," or c == 0 */ 374 375 if ((kwlen = p - q) == 0) { 376 *newbits = tmp; 377 continue; 378 } 379 380 found = 0; 381 #define DBG_SET_FLAG_MIN(S,F) \ 382 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \ 383 tmp |= found = (1 << PMC_DEBUG_MIN_ ## F) 384 385 /* a '*' denotes all possible flags in the group */ 386 if (kwlen == 1 && *q == '*') 387 tmp = found = ~0; 388 /* look for individual flag names */ 389 DBG_SET_FLAG_MIN("allocaterow", ALR); 390 DBG_SET_FLAG_MIN("allocate", ALL); 391 DBG_SET_FLAG_MIN("attach", ATT); 392 DBG_SET_FLAG_MIN("bind", BND); 393 DBG_SET_FLAG_MIN("config", CFG); 394 DBG_SET_FLAG_MIN("exec", EXC); 395 DBG_SET_FLAG_MIN("exit", EXT); 396 DBG_SET_FLAG_MIN("find", FND); 397 DBG_SET_FLAG_MIN("flush", FLS); 398 DBG_SET_FLAG_MIN("fork", FRK); 399 DBG_SET_FLAG_MIN("getbuf", GTB); 400 DBG_SET_FLAG_MIN("hook", PMH); 401 DBG_SET_FLAG_MIN("init", INI); 402 DBG_SET_FLAG_MIN("intr", INT); 403 DBG_SET_FLAG_MIN("linktarget", TLK); 404 DBG_SET_FLAG_MIN("mayberemove", OMR); 405 DBG_SET_FLAG_MIN("ops", OPS); 406 DBG_SET_FLAG_MIN("read", REA); 407 DBG_SET_FLAG_MIN("register", REG); 408 DBG_SET_FLAG_MIN("release", REL); 409 DBG_SET_FLAG_MIN("remove", ORM); 410 DBG_SET_FLAG_MIN("sample", SAM); 411 DBG_SET_FLAG_MIN("scheduleio", SIO); 412 DBG_SET_FLAG_MIN("select", SEL); 413 DBG_SET_FLAG_MIN("signal", SIG); 414 DBG_SET_FLAG_MIN("swi", SWI); 415 DBG_SET_FLAG_MIN("swo", SWO); 416 DBG_SET_FLAG_MIN("start", STA); 417 DBG_SET_FLAG_MIN("stop", STO); 418 DBG_SET_FLAG_MIN("syscall", PMS); 419 DBG_SET_FLAG_MIN("unlinktarget", TUL); 420 DBG_SET_FLAG_MIN("write", WRI); 421 if (found == 0) { 422 /* unrecognized flag name */ 423 error = EINVAL; 424 goto done; 425 } 426 427 if (c == 0 || c == ' ' || c == '\t') { /* end of flag group */ 428 *newbits = tmp; 429 continue; 430 } 431 432 p++; 433 goto newflag; 434 } 435 436 /* save the new flag set */ 437 bcopy(tmpflags, &pmc_debugflags, sizeof(pmc_debugflags)); 438 439 done: 440 FREE(tmpflags, M_PMC); 441 return error; 442 } 443 444 static int 445 pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS) 446 { 447 char *fence, *newstr; 448 int error; 449 unsigned int n; 450 451 (void) arg1; (void) arg2; /* unused parameters */ 452 453 n = sizeof(pmc_debugstr); 454 MALLOC(newstr, char *, n, M_PMC, M_ZERO|M_WAITOK); 455 (void) strlcpy(newstr, pmc_debugstr, n); 456 457 error = sysctl_handle_string(oidp, newstr, n, req); 458 459 /* if there is a new string, parse and copy it */ 460 if (error == 0 && req->newptr != NULL) { 461 fence = newstr + (n < req->newlen ? n : req->newlen + 1); 462 if ((error = pmc_debugflags_parse(newstr, fence)) == 0) 463 (void) strlcpy(pmc_debugstr, newstr, 464 sizeof(pmc_debugstr)); 465 } 466 467 FREE(newstr, M_PMC); 468 469 return error; 470 } 471 #endif 472 473 /* 474 * Concurrency Control 475 * 476 * The driver manages the following data structures: 477 * 478 * - target process descriptors, one per target process 479 * - owner process descriptors (and attached lists), one per owner process 480 * - lookup hash tables for owner and target processes 481 * - PMC descriptors (and attached lists) 482 * - per-cpu hardware state 483 * - the 'hook' variable through which the kernel calls into 484 * this module 485 * - the machine hardware state (managed by the MD layer) 486 * 487 * These data structures are accessed from: 488 * 489 * - thread context-switch code 490 * - interrupt handlers (possibly on multiple cpus) 491 * - kernel threads on multiple cpus running on behalf of user 492 * processes doing system calls 493 * - this driver's private kernel threads 494 * 495 * = Locks and Locking strategy = 496 * 497 * The driver uses four locking strategies for its operation: 498 * 499 * - There is a 'global' SX lock "pmc_sx" that is used to protect 500 * the its 'meta-data'. 501 * 502 * Calls into the module (via syscall() or by the kernel) start with 503 * this lock being held in exclusive mode. Depending on the requested 504 * operation, the lock may be downgraded to 'shared' mode to allow 505 * more concurrent readers into the module. 506 * 507 * This SX lock is held in exclusive mode for any operations that 508 * modify the linkages between the driver's internal data structures. 509 * 510 * The 'pmc_hook' function pointer is also protected by this lock. 511 * It is only examined with the sx lock held in exclusive mode. The 512 * kernel module is allowed to be unloaded only with the sx lock 513 * held in exclusive mode. In normal syscall handling, after 514 * acquiring the pmc_sx lock we first check that 'pmc_hook' is 515 * non-null before proceeding. This prevents races between the 516 * thread unloading the module and other threads seeking to use the 517 * module. 518 * 519 * - Lookups of target process structures and owner process structures 520 * cannot use the global "pmc_sx" SX lock because these lookups need 521 * to happen during context switches and in other critical sections 522 * where sleeping is not allowed. We protect these lookup tables 523 * with their own private spin-mutexes, "pmc_processhash_mtx" and 524 * "pmc_ownerhash_mtx". These are 'leaf' mutexes, in that no other 525 * lock is acquired with these locks held. 526 * 527 * - Interrupt handlers work in a lock free manner. At interrupt 528 * time, handlers look at the PMC pointer (phw->phw_pmc) configured 529 * when the PMC was started. If this pointer is NULL, the interrupt 530 * is ignored after updating driver statistics. We ensure that this 531 * pointer is set (using an atomic operation if necessary) before the 532 * PMC hardware is started. Conversely, this pointer is unset atomically 533 * only after the PMC hardware is stopped. 534 * 535 * We ensure that everything needed for the operation of an 536 * interrupt handler is available without it needing to acquire any 537 * locks. We also ensure that a PMC's software state is destroyed only 538 * after the PMC is taken off hardware (on all CPUs). 539 * 540 * - Context-switch handling with process-private PMCs needs more 541 * care. 542 * 543 * A given process may be the target of multiple PMCs. For example, 544 * PMCATTACH and PMCDETACH may be requested by a process on one CPU 545 * while the target process is running on another. A PMC could also 546 * be getting released because its owner is exiting. We tackle 547 * these situations in the following manner: 548 * 549 * - each target process structure 'pmc_process' has an array 550 * of 'struct pmc *' pointers, one for each hardware PMC. 551 * 552 * - At context switch IN time, each "target" PMC in RUNNING state 553 * gets started on hardware and a pointer to each PMC is copied into 554 * the per-cpu phw array. The 'runcount' for the PMC is 555 * incremented. 556 * 557 * - At context switch OUT time, all process-virtual PMCs are stopped 558 * on hardware. The saved value is added to the PMCs value field 559 * only if the PMC is in a non-deleted state (the PMCs state could 560 * have changed during the current time slice). 561 * 562 * Note that since in-between a switch IN on a processor and a switch 563 * OUT, the PMC could have been released on another CPU. Therefore 564 * context switch OUT always looks at the hardware state to turn 565 * OFF PMCs and will update a PMC's saved value only if reachable 566 * from the target process record. 567 * 568 * - OP PMCRELEASE could be called on a PMC at any time (the PMC could 569 * be attached to many processes at the time of the call and could 570 * be active on multiple CPUs). 571 * 572 * We prevent further scheduling of the PMC by marking it as in 573 * state 'DELETED'. If the runcount of the PMC is non-zero then 574 * this PMC is currently running on a CPU somewhere. The thread 575 * doing the PMCRELEASE operation waits by repeatedly doing an 576 * tsleep() till the runcount comes to zero. 577 * 578 */ 579 580 /* 581 * save the cpu binding of the current kthread 582 */ 583 584 static void 585 pmc_save_cpu_binding(struct pmc_binding *pb) 586 { 587 PMCDBG(CPU,BND,2, "%s", "save-cpu"); 588 mtx_lock_spin(&sched_lock); 589 pb->pb_bound = sched_is_bound(curthread); 590 pb->pb_cpu = curthread->td_oncpu; 591 mtx_unlock_spin(&sched_lock); 592 PMCDBG(CPU,BND,2, "save-cpu cpu=%d", pb->pb_cpu); 593 } 594 595 /* 596 * restore the cpu binding of the current thread 597 */ 598 599 static void 600 pmc_restore_cpu_binding(struct pmc_binding *pb) 601 { 602 PMCDBG(CPU,BND,2, "restore-cpu curcpu=%d restore=%d", 603 curthread->td_oncpu, pb->pb_cpu); 604 mtx_lock_spin(&sched_lock); 605 if (pb->pb_bound) 606 sched_bind(curthread, pb->pb_cpu); 607 else 608 sched_unbind(curthread); 609 mtx_unlock_spin(&sched_lock); 610 PMCDBG(CPU,BND,2, "%s", "restore-cpu done"); 611 } 612 613 /* 614 * move execution over the specified cpu and bind it there. 615 */ 616 617 static void 618 pmc_select_cpu(int cpu) 619 { 620 KASSERT(cpu >= 0 && cpu < mp_ncpus, 621 ("[pmc,%d] bad cpu number %d", __LINE__, cpu)); 622 623 /* never move to a disabled CPU */ 624 KASSERT(pmc_cpu_is_disabled(cpu) == 0, ("[pmc,%d] selecting " 625 "disabled CPU %d", __LINE__, cpu)); 626 627 PMCDBG(CPU,SEL,2, "select-cpu cpu=%d", cpu); 628 mtx_lock_spin(&sched_lock); 629 sched_bind(curthread, cpu); 630 mtx_unlock_spin(&sched_lock); 631 632 KASSERT(curthread->td_oncpu == cpu, 633 ("[pmc,%d] CPU not bound [cpu=%d, curr=%d]", __LINE__, 634 cpu, curthread->td_oncpu)); 635 636 PMCDBG(CPU,SEL,2, "select-cpu cpu=%d ok", cpu); 637 } 638 639 /* 640 * Force a context switch. 641 * 642 * We do this by tsleep'ing for 1 tick -- invoking mi_switch() is not 643 * guaranteed to force a context switch. 644 */ 645 646 static void 647 pmc_force_context_switch(void) 648 { 649 u_char curpri; 650 651 mtx_lock_spin(&sched_lock); 652 curpri = curthread->td_priority; 653 mtx_unlock_spin(&sched_lock); 654 655 (void) tsleep((void *) pmc_force_context_switch, curpri, 656 "pmcctx", 1); 657 658 } 659 660 /* 661 * Get the file name for an executable. This is a simple wrapper 662 * around vn_fullpath(9). 663 */ 664 665 static void 666 pmc_getfilename(struct vnode *v, char **fullpath, char **freepath) 667 { 668 struct thread *td; 669 670 td = curthread; 671 *fullpath = "unknown"; 672 *freepath = NULL; 673 vn_lock(v, LK_CANRECURSE | LK_EXCLUSIVE | LK_RETRY, td); 674 vn_fullpath(td, v, fullpath, freepath); 675 VOP_UNLOCK(v, 0, td); 676 } 677 678 /* 679 * remove an process owning PMCs 680 */ 681 682 void 683 pmc_remove_owner(struct pmc_owner *po) 684 { 685 struct pmc *pm, *tmp; 686 687 sx_assert(&pmc_sx, SX_XLOCKED); 688 689 PMCDBG(OWN,ORM,1, "remove-owner po=%p", po); 690 691 /* Remove descriptor from the owner hash table */ 692 LIST_REMOVE(po, po_next); 693 694 /* release all owned PMC descriptors */ 695 LIST_FOREACH_SAFE(pm, &po->po_pmcs, pm_next, tmp) { 696 PMCDBG(OWN,ORM,2, "pmc=%p", pm); 697 KASSERT(pm->pm_owner == po, 698 ("[pmc,%d] owner %p != po %p", __LINE__, pm->pm_owner, po)); 699 700 pmc_release_pmc_descriptor(pm); /* will unlink from the list */ 701 } 702 703 KASSERT(po->po_sscount == 0, 704 ("[pmc,%d] SS count not zero", __LINE__)); 705 KASSERT(LIST_EMPTY(&po->po_pmcs), 706 ("[pmc,%d] PMC list not empty", __LINE__)); 707 708 /* de-configure the log file if present */ 709 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 710 pmclog_deconfigure_log(po); 711 } 712 713 /* 714 * remove an owner process record if all conditions are met. 715 */ 716 717 static void 718 pmc_maybe_remove_owner(struct pmc_owner *po) 719 { 720 721 PMCDBG(OWN,OMR,1, "maybe-remove-owner po=%p", po); 722 723 /* 724 * Remove owner record if 725 * - this process does not own any PMCs 726 * - this process has not allocated a system-wide sampling buffer 727 */ 728 729 if (LIST_EMPTY(&po->po_pmcs) && 730 ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0)) { 731 pmc_remove_owner(po); 732 pmc_destroy_owner_descriptor(po); 733 } 734 } 735 736 /* 737 * Add an association between a target process and a PMC. 738 */ 739 740 static void 741 pmc_link_target_process(struct pmc *pm, struct pmc_process *pp) 742 { 743 int ri; 744 struct pmc_target *pt; 745 746 sx_assert(&pmc_sx, SX_XLOCKED); 747 748 KASSERT(pm != NULL && pp != NULL, 749 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 750 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 751 ("[pmc,%d] Attaching a non-process-virtual pmc=%p to pid=%d", 752 __LINE__, pm, pp->pp_proc->p_pid)); 753 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt < ((int) md->pmd_npmc - 1), 754 ("[pmc,%d] Illegal reference count %d for process record %p", 755 __LINE__, pp->pp_refcnt, (void *) pp)); 756 757 ri = PMC_TO_ROWINDEX(pm); 758 759 PMCDBG(PRC,TLK,1, "link-target pmc=%p ri=%d pmc-process=%p", 760 pm, ri, pp); 761 762 #ifdef DEBUG 763 LIST_FOREACH(pt, &pm->pm_targets, pt_next) 764 if (pt->pt_process == pp) 765 KASSERT(0, ("[pmc,%d] pp %p already in pmc %p targets", 766 __LINE__, pp, pm)); 767 #endif 768 769 MALLOC(pt, struct pmc_target *, sizeof(struct pmc_target), 770 M_PMC, M_ZERO|M_WAITOK); 771 772 pt->pt_process = pp; 773 774 LIST_INSERT_HEAD(&pm->pm_targets, pt, pt_next); 775 776 atomic_store_rel_ptr((uintptr_t *)&pp->pp_pmcs[ri].pp_pmc, 777 (uintptr_t)pm); 778 779 if (pm->pm_owner->po_owner == pp->pp_proc) 780 pm->pm_flags |= PMC_F_ATTACHED_TO_OWNER; 781 782 /* 783 * Initialize the per-process values at this row index. 784 */ 785 pp->pp_pmcs[ri].pp_pmcval = PMC_TO_MODE(pm) == PMC_MODE_TS ? 786 pm->pm_sc.pm_reloadcount : 0; 787 788 pp->pp_refcnt++; 789 790 } 791 792 /* 793 * Removes the association between a target process and a PMC. 794 */ 795 796 static void 797 pmc_unlink_target_process(struct pmc *pm, struct pmc_process *pp) 798 { 799 int ri; 800 struct proc *p; 801 struct pmc_target *ptgt; 802 803 sx_assert(&pmc_sx, SX_XLOCKED); 804 805 KASSERT(pm != NULL && pp != NULL, 806 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 807 808 KASSERT(pp->pp_refcnt >= 1 && pp->pp_refcnt < (int) md->pmd_npmc, 809 ("[pmc,%d] Illegal ref count %d on process record %p", 810 __LINE__, pp->pp_refcnt, (void *) pp)); 811 812 ri = PMC_TO_ROWINDEX(pm); 813 814 PMCDBG(PRC,TUL,1, "unlink-target pmc=%p ri=%d pmc-process=%p", 815 pm, ri, pp); 816 817 KASSERT(pp->pp_pmcs[ri].pp_pmc == pm, 818 ("[pmc,%d] PMC ri %d mismatch pmc %p pp->[ri] %p", __LINE__, 819 ri, pm, pp->pp_pmcs[ri].pp_pmc)); 820 821 pp->pp_pmcs[ri].pp_pmc = NULL; 822 pp->pp_pmcs[ri].pp_pmcval = (pmc_value_t) 0; 823 824 /* Remove owner-specific flags */ 825 if (pm->pm_owner->po_owner == pp->pp_proc) { 826 pp->pp_flags &= ~PMC_PP_ENABLE_MSR_ACCESS; 827 pm->pm_flags &= ~PMC_F_ATTACHED_TO_OWNER; 828 } 829 830 pp->pp_refcnt--; 831 832 /* Remove the target process from the PMC structure */ 833 LIST_FOREACH(ptgt, &pm->pm_targets, pt_next) 834 if (ptgt->pt_process == pp) 835 break; 836 837 KASSERT(ptgt != NULL, ("[pmc,%d] process %p (pp: %p) not found " 838 "in pmc %p", __LINE__, pp->pp_proc, pp, pm)); 839 840 LIST_REMOVE(ptgt, pt_next); 841 FREE(ptgt, M_PMC); 842 843 /* if the PMC now lacks targets, send the owner a SIGIO */ 844 if (LIST_EMPTY(&pm->pm_targets)) { 845 p = pm->pm_owner->po_owner; 846 PROC_LOCK(p); 847 psignal(p, SIGIO); 848 PROC_UNLOCK(p); 849 850 PMCDBG(PRC,SIG,2, "signalling proc=%p signal=%d", p, 851 SIGIO); 852 } 853 } 854 855 /* 856 * Check if PMC 'pm' may be attached to target process 't'. 857 */ 858 859 static int 860 pmc_can_attach(struct pmc *pm, struct proc *t) 861 { 862 struct proc *o; /* pmc owner */ 863 struct ucred *oc, *tc; /* owner, target credentials */ 864 int decline_attach, i; 865 866 /* 867 * A PMC's owner can always attach that PMC to itself. 868 */ 869 870 if ((o = pm->pm_owner->po_owner) == t) 871 return 0; 872 873 PROC_LOCK(o); 874 oc = o->p_ucred; 875 crhold(oc); 876 PROC_UNLOCK(o); 877 878 PROC_LOCK(t); 879 tc = t->p_ucred; 880 crhold(tc); 881 PROC_UNLOCK(t); 882 883 /* 884 * The effective uid of the PMC owner should match at least one 885 * of the {effective,real,saved} uids of the target process. 886 */ 887 888 decline_attach = oc->cr_uid != tc->cr_uid && 889 oc->cr_uid != tc->cr_svuid && 890 oc->cr_uid != tc->cr_ruid; 891 892 /* 893 * Every one of the target's group ids, must be in the owner's 894 * group list. 895 */ 896 for (i = 0; !decline_attach && i < tc->cr_ngroups; i++) 897 decline_attach = !groupmember(tc->cr_groups[i], oc); 898 899 /* check the read and saved gids too */ 900 if (decline_attach == 0) 901 decline_attach = !groupmember(tc->cr_rgid, oc) || 902 !groupmember(tc->cr_svgid, oc); 903 904 crfree(tc); 905 crfree(oc); 906 907 return !decline_attach; 908 } 909 910 /* 911 * Attach a process to a PMC. 912 */ 913 914 static int 915 pmc_attach_one_process(struct proc *p, struct pmc *pm) 916 { 917 int ri; 918 char *fullpath, *freepath; 919 struct pmc_process *pp; 920 921 sx_assert(&pmc_sx, SX_XLOCKED); 922 923 PMCDBG(PRC,ATT,2, "attach-one pm=%p ri=%d proc=%p (%d, %s)", pm, 924 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 925 926 /* 927 * Locate the process descriptor corresponding to process 'p', 928 * allocating space as needed. 929 * 930 * Verify that rowindex 'pm_rowindex' is free in the process 931 * descriptor. 932 * 933 * If not, allocate space for a descriptor and link the 934 * process descriptor and PMC. 935 */ 936 ri = PMC_TO_ROWINDEX(pm); 937 938 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_ALLOCATE)) == NULL) 939 return ENOMEM; 940 941 if (pp->pp_pmcs[ri].pp_pmc == pm) /* already present at slot [ri] */ 942 return EEXIST; 943 944 if (pp->pp_pmcs[ri].pp_pmc != NULL) 945 return EBUSY; 946 947 pmc_link_target_process(pm, pp); 948 949 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) && 950 (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) == 0) 951 pm->pm_flags |= PMC_F_NEEDS_LOGFILE; 952 953 pm->pm_flags |= PMC_F_ATTACH_DONE; /* mark as attached */ 954 955 /* issue an attach event to a configured log file */ 956 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) { 957 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 958 pmclog_process_pmcattach(pm, p->p_pid, fullpath); 959 if (freepath) 960 FREE(freepath, M_TEMP); 961 } 962 /* mark process as using HWPMCs */ 963 PROC_LOCK(p); 964 p->p_flag |= P_HWPMC; 965 PROC_UNLOCK(p); 966 967 return 0; 968 } 969 970 /* 971 * Attach a process and optionally its children 972 */ 973 974 static int 975 pmc_attach_process(struct proc *p, struct pmc *pm) 976 { 977 int error; 978 struct proc *top; 979 980 sx_assert(&pmc_sx, SX_XLOCKED); 981 982 PMCDBG(PRC,ATT,1, "attach pm=%p ri=%d proc=%p (%d, %s)", pm, 983 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 984 985 986 /* 987 * If this PMC successfully allowed a GETMSR operation 988 * in the past, disallow further ATTACHes. 989 */ 990 991 if ((pm->pm_flags & PMC_PP_ENABLE_MSR_ACCESS) != 0) 992 return EPERM; 993 994 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 995 return pmc_attach_one_process(p, pm); 996 997 /* 998 * Traverse all child processes, attaching them to 999 * this PMC. 1000 */ 1001 1002 sx_slock(&proctree_lock); 1003 1004 top = p; 1005 1006 for (;;) { 1007 if ((error = pmc_attach_one_process(p, pm)) != 0) 1008 break; 1009 if (!LIST_EMPTY(&p->p_children)) 1010 p = LIST_FIRST(&p->p_children); 1011 else for (;;) { 1012 if (p == top) 1013 goto done; 1014 if (LIST_NEXT(p, p_sibling)) { 1015 p = LIST_NEXT(p, p_sibling); 1016 break; 1017 } 1018 p = p->p_pptr; 1019 } 1020 } 1021 1022 if (error) 1023 (void) pmc_detach_process(top, pm); 1024 1025 done: 1026 sx_sunlock(&proctree_lock); 1027 return error; 1028 } 1029 1030 /* 1031 * Detach a process from a PMC. If there are no other PMCs tracking 1032 * this process, remove the process structure from its hash table. If 1033 * 'flags' contains PMC_FLAG_REMOVE, then free the process structure. 1034 */ 1035 1036 static int 1037 pmc_detach_one_process(struct proc *p, struct pmc *pm, int flags) 1038 { 1039 int ri; 1040 struct pmc_process *pp; 1041 1042 sx_assert(&pmc_sx, SX_XLOCKED); 1043 1044 KASSERT(pm != NULL, 1045 ("[pmc,%d] null pm pointer", __LINE__)); 1046 1047 ri = PMC_TO_ROWINDEX(pm); 1048 1049 PMCDBG(PRC,ATT,2, "detach-one pm=%p ri=%d proc=%p (%d, %s) flags=0x%x", 1050 pm, ri, p, p->p_pid, p->p_comm, flags); 1051 1052 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) 1053 return ESRCH; 1054 1055 if (pp->pp_pmcs[ri].pp_pmc != pm) 1056 return EINVAL; 1057 1058 pmc_unlink_target_process(pm, pp); 1059 1060 /* Issue a detach entry if a log file is configured */ 1061 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) 1062 pmclog_process_pmcdetach(pm, p->p_pid); 1063 1064 /* 1065 * If there are no PMCs targetting this process, we remove its 1066 * descriptor from the target hash table and unset the P_HWPMC 1067 * flag in the struct proc. 1068 */ 1069 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt < (int) md->pmd_npmc, 1070 ("[pmc,%d] Illegal refcnt %d for process struct %p", 1071 __LINE__, pp->pp_refcnt, pp)); 1072 1073 if (pp->pp_refcnt != 0) /* still a target of some PMC */ 1074 return 0; 1075 1076 pmc_remove_process_descriptor(pp); 1077 1078 if (flags & PMC_FLAG_REMOVE) 1079 FREE(pp, M_PMC); 1080 1081 PROC_LOCK(p); 1082 p->p_flag &= ~P_HWPMC; 1083 PROC_UNLOCK(p); 1084 1085 return 0; 1086 } 1087 1088 /* 1089 * Detach a process and optionally its descendants from a PMC. 1090 */ 1091 1092 static int 1093 pmc_detach_process(struct proc *p, struct pmc *pm) 1094 { 1095 struct proc *top; 1096 1097 sx_assert(&pmc_sx, SX_XLOCKED); 1098 1099 PMCDBG(PRC,ATT,1, "detach pm=%p ri=%d proc=%p (%d, %s)", pm, 1100 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1101 1102 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 1103 return pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); 1104 1105 /* 1106 * Traverse all children, detaching them from this PMC. We 1107 * ignore errors since we could be detaching a PMC from a 1108 * partially attached proc tree. 1109 */ 1110 1111 sx_slock(&proctree_lock); 1112 1113 top = p; 1114 1115 for (;;) { 1116 (void) pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); 1117 1118 if (!LIST_EMPTY(&p->p_children)) 1119 p = LIST_FIRST(&p->p_children); 1120 else for (;;) { 1121 if (p == top) 1122 goto done; 1123 if (LIST_NEXT(p, p_sibling)) { 1124 p = LIST_NEXT(p, p_sibling); 1125 break; 1126 } 1127 p = p->p_pptr; 1128 } 1129 } 1130 1131 done: 1132 sx_sunlock(&proctree_lock); 1133 1134 if (LIST_EMPTY(&pm->pm_targets)) 1135 pm->pm_flags &= ~PMC_F_ATTACH_DONE; 1136 1137 return 0; 1138 } 1139 1140 1141 /* 1142 * Thread context switch IN 1143 */ 1144 1145 static void 1146 pmc_process_csw_in(struct thread *td) 1147 { 1148 int cpu; 1149 unsigned int ri; 1150 struct pmc *pm; 1151 struct proc *p; 1152 struct pmc_cpu *pc; 1153 struct pmc_hw *phw; 1154 struct pmc_process *pp; 1155 pmc_value_t newvalue; 1156 1157 p = td->td_proc; 1158 1159 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE)) == NULL) 1160 return; 1161 1162 KASSERT(pp->pp_proc == td->td_proc, 1163 ("[pmc,%d] not my thread state", __LINE__)); 1164 1165 critical_enter(); /* no preemption from this point */ 1166 1167 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1168 1169 PMCDBG(CSW,SWI,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1170 p->p_pid, p->p_comm, pp); 1171 1172 KASSERT(cpu >= 0 && cpu < mp_ncpus, 1173 ("[pmc,%d] wierd CPU id %d", __LINE__, cpu)); 1174 1175 pc = pmc_pcpu[cpu]; 1176 1177 for (ri = 0; ri < md->pmd_npmc; ri++) { 1178 1179 if ((pm = pp->pp_pmcs[ri].pp_pmc) == NULL) 1180 continue; 1181 1182 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 1183 ("[pmc,%d] Target PMC in non-virtual mode (%d)", 1184 __LINE__, PMC_TO_MODE(pm))); 1185 1186 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1187 ("[pmc,%d] Row index mismatch pmc %d != ri %d", 1188 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1189 1190 /* 1191 * Only PMCs that are marked as 'RUNNING' need 1192 * be placed on hardware. 1193 */ 1194 1195 if (pm->pm_state != PMC_STATE_RUNNING) 1196 continue; 1197 1198 /* increment PMC runcount */ 1199 atomic_add_rel_32(&pm->pm_runcount, 1); 1200 1201 /* configure the HWPMC we are going to use. */ 1202 md->pmd_config_pmc(cpu, ri, pm); 1203 1204 phw = pc->pc_hwpmcs[ri]; 1205 1206 KASSERT(phw != NULL, 1207 ("[pmc,%d] null hw pointer", __LINE__)); 1208 1209 KASSERT(phw->phw_pmc == pm, 1210 ("[pmc,%d] hw->pmc %p != pmc %p", __LINE__, 1211 phw->phw_pmc, pm)); 1212 1213 /* 1214 * Write out saved value and start the PMC. 1215 * 1216 * Sampling PMCs use a per-process value, while 1217 * counting mode PMCs use a per-pmc value that is 1218 * inherited across descendants. 1219 */ 1220 if (PMC_TO_MODE(pm) == PMC_MODE_TS) { 1221 mtx_pool_lock_spin(pmc_mtxpool, pm); 1222 newvalue = PMC_PCPU_SAVED(cpu,ri) = 1223 pp->pp_pmcs[ri].pp_pmcval; 1224 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1225 } else { 1226 KASSERT(PMC_TO_MODE(pm) == PMC_MODE_TC, 1227 ("[pmc,%d] illegal mode=%d", __LINE__, 1228 PMC_TO_MODE(pm))); 1229 mtx_pool_lock_spin(pmc_mtxpool, pm); 1230 newvalue = PMC_PCPU_SAVED(cpu, ri) = 1231 pm->pm_gv.pm_savedvalue; 1232 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1233 } 1234 1235 PMCDBG(CSW,SWI,1,"cpu=%d ri=%d new=%jd", cpu, ri, newvalue); 1236 1237 md->pmd_write_pmc(cpu, ri, newvalue); 1238 md->pmd_start_pmc(cpu, ri); 1239 } 1240 1241 /* 1242 * perform any other architecture/cpu dependent thread 1243 * switch-in actions. 1244 */ 1245 1246 (void) (*md->pmd_switch_in)(pc, pp); 1247 1248 critical_exit(); 1249 1250 } 1251 1252 /* 1253 * Thread context switch OUT. 1254 */ 1255 1256 static void 1257 pmc_process_csw_out(struct thread *td) 1258 { 1259 int cpu; 1260 enum pmc_mode mode; 1261 unsigned int ri; 1262 struct pmc *pm; 1263 struct proc *p; 1264 struct pmc_cpu *pc; 1265 struct pmc_process *pp; 1266 int64_t tmp; 1267 pmc_value_t newvalue; 1268 1269 /* 1270 * Locate our process descriptor; this may be NULL if 1271 * this process is exiting and we have already removed 1272 * the process from the target process table. 1273 * 1274 * Note that due to kernel preemption, multiple 1275 * context switches may happen while the process is 1276 * exiting. 1277 * 1278 * Note also that if the target process cannot be 1279 * found we still need to deconfigure any PMCs that 1280 * are currently running on hardware. 1281 */ 1282 1283 p = td->td_proc; 1284 pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE); 1285 1286 /* 1287 * save PMCs 1288 */ 1289 1290 critical_enter(); 1291 1292 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1293 1294 PMCDBG(CSW,SWO,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1295 p->p_pid, p->p_comm, pp); 1296 1297 KASSERT(cpu >= 0 && cpu < mp_ncpus, 1298 ("[pmc,%d wierd CPU id %d", __LINE__, cpu)); 1299 1300 pc = pmc_pcpu[cpu]; 1301 1302 /* 1303 * When a PMC gets unlinked from a target PMC, it will 1304 * be removed from the target's pp_pmc[] array. 1305 * 1306 * However, on a MP system, the target could have been 1307 * executing on another CPU at the time of the unlink. 1308 * So, at context switch OUT time, we need to look at 1309 * the hardware to determine if a PMC is scheduled on 1310 * it. 1311 */ 1312 1313 for (ri = 0; ri < md->pmd_npmc; ri++) { 1314 1315 pm = NULL; 1316 (void) (*md->pmd_get_config)(cpu, ri, &pm); 1317 1318 if (pm == NULL) /* nothing at this row index */ 1319 continue; 1320 1321 mode = PMC_TO_MODE(pm); 1322 if (!PMC_IS_VIRTUAL_MODE(mode)) 1323 continue; /* not a process virtual PMC */ 1324 1325 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1326 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 1327 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1328 1329 /* Stop hardware if not already stopped */ 1330 if (pm->pm_stalled == 0) 1331 md->pmd_stop_pmc(cpu, ri); 1332 1333 /* reduce this PMC's runcount */ 1334 atomic_subtract_rel_32(&pm->pm_runcount, 1); 1335 1336 /* 1337 * If this PMC is associated with this process, 1338 * save the reading. 1339 */ 1340 1341 if (pp != NULL && pp->pp_pmcs[ri].pp_pmc != NULL) { 1342 1343 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 1344 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", __LINE__, 1345 pm, ri, pp->pp_pmcs[ri].pp_pmc)); 1346 1347 KASSERT(pp->pp_refcnt > 0, 1348 ("[pmc,%d] pp refcnt = %d", __LINE__, 1349 pp->pp_refcnt)); 1350 1351 md->pmd_read_pmc(cpu, ri, &newvalue); 1352 1353 tmp = newvalue - PMC_PCPU_SAVED(cpu,ri); 1354 1355 PMCDBG(CSW,SWI,1,"cpu=%d ri=%d tmp=%jd", cpu, ri, 1356 tmp); 1357 1358 if (mode == PMC_MODE_TS) { 1359 1360 /* 1361 * For sampling process-virtual PMCs, 1362 * we expect the count to be 1363 * decreasing as the 'value' 1364 * programmed into the PMC is the 1365 * number of events to be seen till 1366 * the next sampling interrupt. 1367 */ 1368 if (tmp < 0) 1369 tmp += pm->pm_sc.pm_reloadcount; 1370 mtx_pool_lock_spin(pmc_mtxpool, pm); 1371 pp->pp_pmcs[ri].pp_pmcval -= tmp; 1372 if ((int64_t) pp->pp_pmcs[ri].pp_pmcval < 0) 1373 pp->pp_pmcs[ri].pp_pmcval += 1374 pm->pm_sc.pm_reloadcount; 1375 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1376 1377 } else { 1378 1379 /* 1380 * For counting process-virtual PMCs, 1381 * we expect the count to be 1382 * increasing monotonically, modulo a 64 1383 * bit wraparound. 1384 */ 1385 KASSERT((int64_t) tmp >= 0, 1386 ("[pmc,%d] negative increment cpu=%d " 1387 "ri=%d newvalue=%jx saved=%jx " 1388 "incr=%jx", __LINE__, cpu, ri, 1389 newvalue, PMC_PCPU_SAVED(cpu,ri), tmp)); 1390 1391 mtx_pool_lock_spin(pmc_mtxpool, pm); 1392 pm->pm_gv.pm_savedvalue += tmp; 1393 pp->pp_pmcs[ri].pp_pmcval += tmp; 1394 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1395 1396 if (pm->pm_flags & PMC_F_LOG_PROCCSW) 1397 pmclog_process_proccsw(pm, pp, tmp); 1398 } 1399 } 1400 1401 /* mark hardware as free */ 1402 md->pmd_config_pmc(cpu, ri, NULL); 1403 } 1404 1405 /* 1406 * perform any other architecture/cpu dependent thread 1407 * switch out functions. 1408 */ 1409 1410 (void) (*md->pmd_switch_out)(pc, pp); 1411 1412 critical_exit(); 1413 } 1414 1415 /* 1416 * Log a KLD operation. 1417 */ 1418 1419 static void 1420 pmc_process_kld_load(struct pmckern_map_in *pkm) 1421 { 1422 struct pmc_owner *po; 1423 1424 sx_assert(&pmc_sx, SX_LOCKED); 1425 1426 /* 1427 * Notify owners of system sampling PMCs about KLD operations. 1428 */ 1429 1430 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1431 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1432 pmclog_process_map_in(po, (pid_t) -1, pkm->pm_address, 1433 (char *) pkm->pm_file); 1434 1435 /* 1436 * TODO: Notify owners of (all) process-sampling PMCs too. 1437 */ 1438 1439 return; 1440 } 1441 1442 static void 1443 pmc_process_kld_unload(struct pmckern_map_out *pkm) 1444 { 1445 struct pmc_owner *po; 1446 1447 sx_assert(&pmc_sx, SX_LOCKED); 1448 1449 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1450 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1451 pmclog_process_map_out(po, (pid_t) -1, 1452 pkm->pm_address, pkm->pm_address + pkm->pm_size); 1453 1454 /* 1455 * TODO: Notify owners of process-sampling PMCs. 1456 */ 1457 } 1458 1459 /* 1460 * A mapping change for a process. 1461 */ 1462 1463 static void 1464 pmc_process_mmap(struct thread *td, struct pmckern_map_in *pkm) 1465 { 1466 int ri; 1467 pid_t pid; 1468 char *fullpath, *freepath; 1469 const struct pmc *pm; 1470 struct pmc_owner *po; 1471 const struct pmc_process *pp; 1472 1473 freepath = fullpath = NULL; 1474 pmc_getfilename((struct vnode *) pkm->pm_file, &fullpath, &freepath); 1475 1476 pid = td->td_proc->p_pid; 1477 1478 /* Inform owners of all system-wide sampling PMCs. */ 1479 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1480 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1481 pmclog_process_map_in(po, pid, pkm->pm_address, fullpath); 1482 1483 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1484 goto done; 1485 1486 /* 1487 * Inform sampling PMC owners tracking this process. 1488 */ 1489 for (ri = 0; ri < md->pmd_npmc; ri++) 1490 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1491 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1492 pmclog_process_map_in(pm->pm_owner, 1493 pid, pkm->pm_address, fullpath); 1494 1495 done: 1496 if (freepath) 1497 FREE(freepath, M_TEMP); 1498 } 1499 1500 1501 /* 1502 * Log an munmap request. 1503 */ 1504 1505 static void 1506 pmc_process_munmap(struct thread *td, struct pmckern_map_out *pkm) 1507 { 1508 int ri; 1509 pid_t pid; 1510 struct pmc_owner *po; 1511 const struct pmc *pm; 1512 const struct pmc_process *pp; 1513 1514 pid = td->td_proc->p_pid; 1515 1516 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1517 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1518 pmclog_process_map_out(po, pid, pkm->pm_address, 1519 pkm->pm_address + pkm->pm_size); 1520 1521 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1522 return; 1523 1524 for (ri = 0; ri < md->pmd_npmc; ri++) 1525 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1526 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1527 pmclog_process_map_out(po, pid, pkm->pm_address, 1528 pkm->pm_address + pkm->pm_size); 1529 } 1530 1531 /* 1532 * The 'hook' invoked from the kernel proper 1533 */ 1534 1535 1536 #ifdef DEBUG 1537 const char *pmc_hooknames[] = { 1538 /* these strings correspond to PMC_FN_* in <sys/pmckern.h> */ 1539 "", 1540 "EXEC", 1541 "CSW-IN", 1542 "CSW-OUT", 1543 "SAMPLE", 1544 "KLDLOAD", 1545 "KLDUNLOAD", 1546 "MMAP", 1547 "MUNMAP" 1548 }; 1549 #endif 1550 1551 static int 1552 pmc_hook_handler(struct thread *td, int function, void *arg) 1553 { 1554 1555 PMCDBG(MOD,PMH,1, "hook td=%p func=%d \"%s\" arg=%p", td, function, 1556 pmc_hooknames[function], arg); 1557 1558 switch (function) 1559 { 1560 1561 /* 1562 * Process exec() 1563 */ 1564 1565 case PMC_FN_PROCESS_EXEC: 1566 { 1567 char *fullpath, *freepath; 1568 unsigned int ri; 1569 int is_using_hwpmcs; 1570 struct pmc *pm; 1571 struct proc *p; 1572 struct pmc_owner *po; 1573 struct pmc_process *pp; 1574 struct pmckern_procexec *pk; 1575 1576 sx_assert(&pmc_sx, SX_XLOCKED); 1577 1578 p = td->td_proc; 1579 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 1580 1581 pk = (struct pmckern_procexec *) arg; 1582 1583 /* Inform owners of SS mode PMCs of the exec event. */ 1584 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1585 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1586 pmclog_process_procexec(po, PMC_ID_INVALID, 1587 p->p_pid, pk->pm_entryaddr, fullpath); 1588 1589 PROC_LOCK(p); 1590 is_using_hwpmcs = p->p_flag & P_HWPMC; 1591 PROC_UNLOCK(p); 1592 1593 if (!is_using_hwpmcs) { 1594 if (freepath) 1595 FREE(freepath, M_TEMP); 1596 break; 1597 } 1598 1599 /* 1600 * PMCs are not inherited across an exec(): remove any 1601 * PMCs that this process is the owner of. 1602 */ 1603 1604 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 1605 pmc_remove_owner(po); 1606 pmc_destroy_owner_descriptor(po); 1607 } 1608 1609 /* 1610 * If the process being exec'ed is not the target of any 1611 * PMC, we are done. 1612 */ 1613 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) { 1614 if (freepath) 1615 FREE(freepath, M_TEMP); 1616 break; 1617 } 1618 1619 /* 1620 * Log the exec event to all monitoring owners. Skip 1621 * owners who have already recieved the event because 1622 * they had system sampling PMCs active. 1623 */ 1624 for (ri = 0; ri < md->pmd_npmc; ri++) 1625 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 1626 po = pm->pm_owner; 1627 if (po->po_sscount == 0 && 1628 po->po_flags & PMC_PO_OWNS_LOGFILE) 1629 pmclog_process_procexec(po, pm->pm_id, 1630 p->p_pid, pk->pm_entryaddr, 1631 fullpath); 1632 } 1633 1634 if (freepath) 1635 FREE(freepath, M_TEMP); 1636 1637 1638 PMCDBG(PRC,EXC,1, "exec proc=%p (%d, %s) cred-changed=%d", 1639 p, p->p_pid, p->p_comm, pk->pm_credentialschanged); 1640 1641 if (pk->pm_credentialschanged == 0) /* no change */ 1642 break; 1643 1644 /* 1645 * If the newly exec()'ed process has a different credential 1646 * than before, allow it to be the target of a PMC only if 1647 * the PMC's owner has sufficient priviledge. 1648 */ 1649 1650 for (ri = 0; ri < md->pmd_npmc; ri++) 1651 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) 1652 if (pmc_can_attach(pm, td->td_proc) != 0) 1653 pmc_detach_one_process(td->td_proc, 1654 pm, PMC_FLAG_NONE); 1655 1656 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt < (int) md->pmd_npmc, 1657 ("[pmc,%d] Illegal ref count %d on pp %p", __LINE__, 1658 pp->pp_refcnt, pp)); 1659 1660 /* 1661 * If this process is no longer the target of any 1662 * PMCs, we can remove the process entry and free 1663 * up space. 1664 */ 1665 1666 if (pp->pp_refcnt == 0) { 1667 pmc_remove_process_descriptor(pp); 1668 FREE(pp, M_PMC); 1669 break; 1670 } 1671 1672 } 1673 break; 1674 1675 case PMC_FN_CSW_IN: 1676 pmc_process_csw_in(td); 1677 break; 1678 1679 case PMC_FN_CSW_OUT: 1680 pmc_process_csw_out(td); 1681 break; 1682 1683 /* 1684 * Process accumulated PC samples. 1685 * 1686 * This function is expected to be called by hardclock() for 1687 * each CPU that has accumulated PC samples. 1688 * 1689 * This function is to be executed on the CPU whose samples 1690 * are being processed. 1691 */ 1692 case PMC_FN_DO_SAMPLES: 1693 1694 /* 1695 * Clear the cpu specific bit in the CPU mask before 1696 * do the rest of the processing. If the NMI handler 1697 * gets invoked after the "atomic_clear_int()" call 1698 * below but before "pmc_process_samples()" gets 1699 * around to processing the interrupt, then we will 1700 * come back here at the next hardclock() tick (and 1701 * may find nothing to do if "pmc_process_samples()" 1702 * had already processed the interrupt). We don't 1703 * lose the interrupt sample. 1704 */ 1705 atomic_clear_int(&pmc_cpumask, (1 << PCPU_GET(cpuid))); 1706 pmc_process_samples(PCPU_GET(cpuid)); 1707 break; 1708 1709 1710 case PMC_FN_KLD_LOAD: 1711 sx_assert(&pmc_sx, SX_LOCKED); 1712 pmc_process_kld_load((struct pmckern_map_in *) arg); 1713 break; 1714 1715 case PMC_FN_KLD_UNLOAD: 1716 sx_assert(&pmc_sx, SX_LOCKED); 1717 pmc_process_kld_unload((struct pmckern_map_out *) arg); 1718 break; 1719 1720 case PMC_FN_MMAP: 1721 sx_assert(&pmc_sx, SX_LOCKED); 1722 pmc_process_mmap(td, (struct pmckern_map_in *) arg); 1723 break; 1724 1725 case PMC_FN_MUNMAP: 1726 sx_assert(&pmc_sx, SX_LOCKED); 1727 pmc_process_munmap(td, (struct pmckern_map_out *) arg); 1728 break; 1729 1730 default: 1731 #ifdef DEBUG 1732 KASSERT(0, ("[pmc,%d] unknown hook %d\n", __LINE__, function)); 1733 #endif 1734 break; 1735 1736 } 1737 1738 return 0; 1739 } 1740 1741 /* 1742 * allocate a 'struct pmc_owner' descriptor in the owner hash table. 1743 */ 1744 1745 static struct pmc_owner * 1746 pmc_allocate_owner_descriptor(struct proc *p) 1747 { 1748 uint32_t hindex; 1749 struct pmc_owner *po; 1750 struct pmc_ownerhash *poh; 1751 1752 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 1753 poh = &pmc_ownerhash[hindex]; 1754 1755 /* allocate space for N pointers and one descriptor struct */ 1756 MALLOC(po, struct pmc_owner *, sizeof(struct pmc_owner), 1757 M_PMC, M_ZERO|M_WAITOK); 1758 1759 po->po_sscount = po->po_error = po->po_flags = 0; 1760 po->po_file = NULL; 1761 po->po_owner = p; 1762 po->po_kthread = NULL; 1763 LIST_INIT(&po->po_pmcs); 1764 LIST_INSERT_HEAD(poh, po, po_next); /* insert into hash table */ 1765 1766 TAILQ_INIT(&po->po_logbuffers); 1767 mtx_init(&po->po_mtx, "pmc-owner-mtx", "pmc", MTX_SPIN); 1768 1769 PMCDBG(OWN,ALL,1, "allocate-owner proc=%p (%d, %s) pmc-owner=%p", 1770 p, p->p_pid, p->p_comm, po); 1771 1772 return po; 1773 } 1774 1775 static void 1776 pmc_destroy_owner_descriptor(struct pmc_owner *po) 1777 { 1778 1779 PMCDBG(OWN,REL,1, "destroy-owner po=%p proc=%p (%d, %s)", 1780 po, po->po_owner, po->po_owner->p_pid, po->po_owner->p_comm); 1781 1782 mtx_destroy(&po->po_mtx); 1783 FREE(po, M_PMC); 1784 } 1785 1786 /* 1787 * find the descriptor corresponding to process 'p', adding or removing it 1788 * as specified by 'mode'. 1789 */ 1790 1791 static struct pmc_process * 1792 pmc_find_process_descriptor(struct proc *p, uint32_t mode) 1793 { 1794 uint32_t hindex; 1795 struct pmc_process *pp, *ppnew; 1796 struct pmc_processhash *pph; 1797 1798 hindex = PMC_HASH_PTR(p, pmc_processhashmask); 1799 pph = &pmc_processhash[hindex]; 1800 1801 ppnew = NULL; 1802 1803 /* 1804 * Pre-allocate memory in the FIND_ALLOCATE case since we 1805 * cannot call malloc(9) once we hold a spin lock. 1806 */ 1807 1808 if (mode & PMC_FLAG_ALLOCATE) { 1809 /* allocate additional space for 'n' pmc pointers */ 1810 MALLOC(ppnew, struct pmc_process *, 1811 sizeof(struct pmc_process) + md->pmd_npmc * 1812 sizeof(struct pmc_targetstate), M_PMC, M_ZERO|M_WAITOK); 1813 } 1814 1815 mtx_lock_spin(&pmc_processhash_mtx); 1816 LIST_FOREACH(pp, pph, pp_next) 1817 if (pp->pp_proc == p) 1818 break; 1819 1820 if ((mode & PMC_FLAG_REMOVE) && pp != NULL) 1821 LIST_REMOVE(pp, pp_next); 1822 1823 if ((mode & PMC_FLAG_ALLOCATE) && pp == NULL && 1824 ppnew != NULL) { 1825 ppnew->pp_proc = p; 1826 LIST_INSERT_HEAD(pph, ppnew, pp_next); 1827 pp = ppnew; 1828 ppnew = NULL; 1829 } 1830 mtx_unlock_spin(&pmc_processhash_mtx); 1831 1832 if (pp != NULL && ppnew != NULL) 1833 FREE(ppnew, M_PMC); 1834 1835 return pp; 1836 } 1837 1838 /* 1839 * remove a process descriptor from the process hash table. 1840 */ 1841 1842 static void 1843 pmc_remove_process_descriptor(struct pmc_process *pp) 1844 { 1845 KASSERT(pp->pp_refcnt == 0, 1846 ("[pmc,%d] Removing process descriptor %p with count %d", 1847 __LINE__, pp, pp->pp_refcnt)); 1848 1849 mtx_lock_spin(&pmc_processhash_mtx); 1850 LIST_REMOVE(pp, pp_next); 1851 mtx_unlock_spin(&pmc_processhash_mtx); 1852 } 1853 1854 1855 /* 1856 * find an owner descriptor corresponding to proc 'p' 1857 */ 1858 1859 static struct pmc_owner * 1860 pmc_find_owner_descriptor(struct proc *p) 1861 { 1862 uint32_t hindex; 1863 struct pmc_owner *po; 1864 struct pmc_ownerhash *poh; 1865 1866 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 1867 poh = &pmc_ownerhash[hindex]; 1868 1869 po = NULL; 1870 LIST_FOREACH(po, poh, po_next) 1871 if (po->po_owner == p) 1872 break; 1873 1874 PMCDBG(OWN,FND,1, "find-owner proc=%p (%d, %s) hindex=0x%x -> " 1875 "pmc-owner=%p", p, p->p_pid, p->p_comm, hindex, po); 1876 1877 return po; 1878 } 1879 1880 /* 1881 * pmc_allocate_pmc_descriptor 1882 * 1883 * Allocate a pmc descriptor and initialize its 1884 * fields. 1885 */ 1886 1887 static struct pmc * 1888 pmc_allocate_pmc_descriptor(void) 1889 { 1890 struct pmc *pmc; 1891 1892 MALLOC(pmc, struct pmc *, sizeof(struct pmc), M_PMC, M_ZERO|M_WAITOK); 1893 1894 if (pmc != NULL) { 1895 pmc->pm_owner = NULL; 1896 LIST_INIT(&pmc->pm_targets); 1897 } 1898 1899 PMCDBG(PMC,ALL,1, "allocate-pmc -> pmc=%p", pmc); 1900 1901 return pmc; 1902 } 1903 1904 /* 1905 * Destroy a pmc descriptor. 1906 */ 1907 1908 static void 1909 pmc_destroy_pmc_descriptor(struct pmc *pm) 1910 { 1911 (void) pm; 1912 1913 #ifdef DEBUG 1914 KASSERT(pm->pm_state == PMC_STATE_DELETED || 1915 pm->pm_state == PMC_STATE_FREE, 1916 ("[pmc,%d] destroying non-deleted PMC", __LINE__)); 1917 KASSERT(LIST_EMPTY(&pm->pm_targets), 1918 ("[pmc,%d] destroying pmc with targets", __LINE__)); 1919 KASSERT(pm->pm_owner == NULL, 1920 ("[pmc,%d] destroying pmc attached to an owner", __LINE__)); 1921 KASSERT(pm->pm_runcount == 0, 1922 ("[pmc,%d] pmc has non-zero run count %d", __LINE__, 1923 pm->pm_runcount)); 1924 #endif 1925 } 1926 1927 static void 1928 pmc_wait_for_pmc_idle(struct pmc *pm) 1929 { 1930 #ifdef DEBUG 1931 volatile int maxloop; 1932 1933 maxloop = 100 * mp_ncpus; 1934 #endif 1935 1936 /* 1937 * Loop (with a forced context switch) till the PMC's runcount 1938 * comes down to zero. 1939 */ 1940 while (atomic_load_acq_32(&pm->pm_runcount) > 0) { 1941 #ifdef DEBUG 1942 maxloop--; 1943 KASSERT(maxloop > 0, 1944 ("[pmc,%d] (ri%d, rc%d) waiting too long for " 1945 "pmc to be free", __LINE__, 1946 PMC_TO_ROWINDEX(pm), pm->pm_runcount)); 1947 #endif 1948 pmc_force_context_switch(); 1949 } 1950 } 1951 1952 /* 1953 * This function does the following things: 1954 * 1955 * - detaches the PMC from hardware 1956 * - unlinks all target threads that were attached to it 1957 * - removes the PMC from its owner's list 1958 * - destroy's the PMC private mutex 1959 * 1960 * Once this function completes, the given pmc pointer can be safely 1961 * FREE'd by the caller. 1962 */ 1963 1964 static void 1965 pmc_release_pmc_descriptor(struct pmc *pm) 1966 { 1967 u_int ri, cpu; 1968 enum pmc_mode mode; 1969 struct pmc_hw *phw; 1970 struct pmc_owner *po; 1971 struct pmc_process *pp; 1972 struct pmc_target *ptgt, *tmp; 1973 struct pmc_binding pb; 1974 1975 sx_assert(&pmc_sx, SX_XLOCKED); 1976 1977 KASSERT(pm, ("[pmc,%d] null pmc", __LINE__)); 1978 1979 ri = PMC_TO_ROWINDEX(pm); 1980 mode = PMC_TO_MODE(pm); 1981 1982 PMCDBG(PMC,REL,1, "release-pmc pmc=%p ri=%d mode=%d", pm, ri, 1983 mode); 1984 1985 /* 1986 * First, we take the PMC off hardware. 1987 */ 1988 cpu = 0; 1989 if (PMC_IS_SYSTEM_MODE(mode)) { 1990 1991 /* 1992 * A system mode PMC runs on a specific CPU. Switch 1993 * to this CPU and turn hardware off. 1994 */ 1995 pmc_save_cpu_binding(&pb); 1996 1997 cpu = PMC_TO_CPU(pm); 1998 1999 pmc_select_cpu(cpu); 2000 2001 /* switch off non-stalled CPUs */ 2002 if (pm->pm_state == PMC_STATE_RUNNING && 2003 pm->pm_stalled == 0) { 2004 2005 phw = pmc_pcpu[cpu]->pc_hwpmcs[ri]; 2006 2007 KASSERT(phw->phw_pmc == pm, 2008 ("[pmc, %d] pmc ptr ri(%d) hw(%p) pm(%p)", 2009 __LINE__, ri, phw->phw_pmc, pm)); 2010 PMCDBG(PMC,REL,2, "stopping cpu=%d ri=%d", cpu, ri); 2011 2012 critical_enter(); 2013 md->pmd_stop_pmc(cpu, ri); 2014 critical_exit(); 2015 } 2016 2017 PMCDBG(PMC,REL,2, "decfg cpu=%d ri=%d", cpu, ri); 2018 2019 critical_enter(); 2020 md->pmd_config_pmc(cpu, ri, NULL); 2021 critical_exit(); 2022 2023 /* adjust the global and process count of SS mode PMCs */ 2024 if (mode == PMC_MODE_SS && pm->pm_state == PMC_STATE_RUNNING) { 2025 po = pm->pm_owner; 2026 po->po_sscount--; 2027 if (po->po_sscount == 0) { 2028 atomic_subtract_rel_int(&pmc_ss_count, 1); 2029 LIST_REMOVE(po, po_ssnext); 2030 } 2031 } 2032 2033 pm->pm_state = PMC_STATE_DELETED; 2034 2035 pmc_restore_cpu_binding(&pb); 2036 2037 /* 2038 * We could have references to this PMC structure in 2039 * the per-cpu sample queues. Wait for the queue to 2040 * drain. 2041 */ 2042 pmc_wait_for_pmc_idle(pm); 2043 2044 } else if (PMC_IS_VIRTUAL_MODE(mode)) { 2045 2046 /* 2047 * A virtual PMC could be running on multiple CPUs at 2048 * a given instant. 2049 * 2050 * By marking its state as DELETED, we ensure that 2051 * this PMC is never further scheduled on hardware. 2052 * 2053 * Then we wait till all CPUs are done with this PMC. 2054 */ 2055 pm->pm_state = PMC_STATE_DELETED; 2056 2057 2058 /* Wait for the PMCs runcount to come to zero. */ 2059 pmc_wait_for_pmc_idle(pm); 2060 2061 /* 2062 * At this point the PMC is off all CPUs and cannot be 2063 * freshly scheduled onto a CPU. It is now safe to 2064 * unlink all targets from this PMC. If a 2065 * process-record's refcount falls to zero, we remove 2066 * it from the hash table. The module-wide SX lock 2067 * protects us from races. 2068 */ 2069 LIST_FOREACH_SAFE(ptgt, &pm->pm_targets, pt_next, tmp) { 2070 pp = ptgt->pt_process; 2071 pmc_unlink_target_process(pm, pp); /* frees 'ptgt' */ 2072 2073 PMCDBG(PMC,REL,3, "pp->refcnt=%d", pp->pp_refcnt); 2074 2075 /* 2076 * If the target process record shows that no 2077 * PMCs are attached to it, reclaim its space. 2078 */ 2079 2080 if (pp->pp_refcnt == 0) { 2081 pmc_remove_process_descriptor(pp); 2082 FREE(pp, M_PMC); 2083 } 2084 } 2085 2086 cpu = curthread->td_oncpu; /* setup cpu for pmd_release() */ 2087 2088 } 2089 2090 /* 2091 * Release any MD resources 2092 */ 2093 2094 (void) md->pmd_release_pmc(cpu, ri, pm); 2095 2096 /* 2097 * Update row disposition 2098 */ 2099 2100 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) 2101 PMC_UNMARK_ROW_STANDALONE(ri); 2102 else 2103 PMC_UNMARK_ROW_THREAD(ri); 2104 2105 /* unlink from the owner's list */ 2106 if (pm->pm_owner) { 2107 LIST_REMOVE(pm, pm_next); 2108 pm->pm_owner = NULL; 2109 } 2110 2111 pmc_destroy_pmc_descriptor(pm); 2112 } 2113 2114 /* 2115 * Register an owner and a pmc. 2116 */ 2117 2118 static int 2119 pmc_register_owner(struct proc *p, struct pmc *pmc) 2120 { 2121 struct pmc_owner *po; 2122 2123 sx_assert(&pmc_sx, SX_XLOCKED); 2124 2125 if ((po = pmc_find_owner_descriptor(p)) == NULL) 2126 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) 2127 return ENOMEM; 2128 2129 KASSERT(pmc->pm_owner == NULL, 2130 ("[pmc,%d] attempting to own an initialized PMC", __LINE__)); 2131 pmc->pm_owner = po; 2132 2133 LIST_INSERT_HEAD(&po->po_pmcs, pmc, pm_next); 2134 2135 PROC_LOCK(p); 2136 p->p_flag |= P_HWPMC; 2137 PROC_UNLOCK(p); 2138 2139 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 2140 pmclog_process_pmcallocate(pmc); 2141 2142 PMCDBG(PMC,REG,1, "register-owner pmc-owner=%p pmc=%p", 2143 po, pmc); 2144 2145 return 0; 2146 } 2147 2148 /* 2149 * Return the current row disposition: 2150 * == 0 => FREE 2151 * > 0 => PROCESS MODE 2152 * < 0 => SYSTEM MODE 2153 */ 2154 2155 int 2156 pmc_getrowdisp(int ri) 2157 { 2158 return pmc_pmcdisp[ri]; 2159 } 2160 2161 /* 2162 * Check if a PMC at row index 'ri' can be allocated to the current 2163 * process. 2164 * 2165 * Allocation can fail if: 2166 * - the current process is already being profiled by a PMC at index 'ri', 2167 * attached to it via OP_PMCATTACH. 2168 * - the current process has already allocated a PMC at index 'ri' 2169 * via OP_ALLOCATE. 2170 */ 2171 2172 static int 2173 pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, int cpu) 2174 { 2175 enum pmc_mode mode; 2176 struct pmc *pm; 2177 struct pmc_owner *po; 2178 struct pmc_process *pp; 2179 2180 PMCDBG(PMC,ALR,1, "can-allocate-rowindex proc=%p (%d, %s) ri=%d " 2181 "cpu=%d", p, p->p_pid, p->p_comm, ri, cpu); 2182 2183 /* 2184 * We shouldn't have already allocated a process-mode PMC at 2185 * row index 'ri'. 2186 * 2187 * We shouldn't have allocated a system-wide PMC on the same 2188 * CPU and same RI. 2189 */ 2190 if ((po = pmc_find_owner_descriptor(p)) != NULL) 2191 LIST_FOREACH(pm, &po->po_pmcs, pm_next) { 2192 if (PMC_TO_ROWINDEX(pm) == ri) { 2193 mode = PMC_TO_MODE(pm); 2194 if (PMC_IS_VIRTUAL_MODE(mode)) 2195 return EEXIST; 2196 if (PMC_IS_SYSTEM_MODE(mode) && 2197 (int) PMC_TO_CPU(pm) == cpu) 2198 return EEXIST; 2199 } 2200 } 2201 2202 /* 2203 * We also shouldn't be the target of any PMC at this index 2204 * since otherwise a PMC_ATTACH to ourselves will fail. 2205 */ 2206 if ((pp = pmc_find_process_descriptor(p, 0)) != NULL) 2207 if (pp->pp_pmcs[ri].pp_pmc) 2208 return EEXIST; 2209 2210 PMCDBG(PMC,ALR,2, "can-allocate-rowindex proc=%p (%d, %s) ri=%d ok", 2211 p, p->p_pid, p->p_comm, ri); 2212 2213 return 0; 2214 } 2215 2216 /* 2217 * Check if a given PMC at row index 'ri' can be currently used in 2218 * mode 'mode'. 2219 */ 2220 2221 static int 2222 pmc_can_allocate_row(int ri, enum pmc_mode mode) 2223 { 2224 enum pmc_disp disp; 2225 2226 sx_assert(&pmc_sx, SX_XLOCKED); 2227 2228 PMCDBG(PMC,ALR,1, "can-allocate-row ri=%d mode=%d", ri, mode); 2229 2230 if (PMC_IS_SYSTEM_MODE(mode)) 2231 disp = PMC_DISP_STANDALONE; 2232 else 2233 disp = PMC_DISP_THREAD; 2234 2235 /* 2236 * check disposition for PMC row 'ri': 2237 * 2238 * Expected disposition Row-disposition Result 2239 * 2240 * STANDALONE STANDALONE or FREE proceed 2241 * STANDALONE THREAD fail 2242 * THREAD THREAD or FREE proceed 2243 * THREAD STANDALONE fail 2244 */ 2245 2246 if (!PMC_ROW_DISP_IS_FREE(ri) && 2247 !(disp == PMC_DISP_THREAD && PMC_ROW_DISP_IS_THREAD(ri)) && 2248 !(disp == PMC_DISP_STANDALONE && PMC_ROW_DISP_IS_STANDALONE(ri))) 2249 return EBUSY; 2250 2251 /* 2252 * All OK 2253 */ 2254 2255 PMCDBG(PMC,ALR,2, "can-allocate-row ri=%d mode=%d ok", ri, mode); 2256 2257 return 0; 2258 2259 } 2260 2261 /* 2262 * Find a PMC descriptor with user handle 'pmcid' for thread 'td'. 2263 */ 2264 2265 static struct pmc * 2266 pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, pmc_id_t pmcid) 2267 { 2268 struct pmc *pm; 2269 2270 KASSERT(PMC_ID_TO_ROWINDEX(pmcid) < md->pmd_npmc, 2271 ("[pmc,%d] Illegal pmc index %d (max %d)", __LINE__, 2272 PMC_ID_TO_ROWINDEX(pmcid), md->pmd_npmc)); 2273 2274 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 2275 if (pm->pm_id == pmcid) 2276 return pm; 2277 2278 return NULL; 2279 } 2280 2281 static int 2282 pmc_find_pmc(pmc_id_t pmcid, struct pmc **pmc) 2283 { 2284 2285 struct pmc *pm; 2286 struct pmc_owner *po; 2287 2288 PMCDBG(PMC,FND,1, "find-pmc id=%d", pmcid); 2289 2290 if ((po = pmc_find_owner_descriptor(curthread->td_proc)) == NULL) 2291 return ESRCH; 2292 2293 if ((pm = pmc_find_pmc_descriptor_in_process(po, pmcid)) == NULL) 2294 return EINVAL; 2295 2296 PMCDBG(PMC,FND,2, "find-pmc id=%d -> pmc=%p", pmcid, pm); 2297 2298 *pmc = pm; 2299 return 0; 2300 } 2301 2302 /* 2303 * Start a PMC. 2304 */ 2305 2306 static int 2307 pmc_start(struct pmc *pm) 2308 { 2309 int error, cpu, ri; 2310 enum pmc_mode mode; 2311 struct pmc_owner *po; 2312 struct pmc_binding pb; 2313 2314 KASSERT(pm != NULL, 2315 ("[pmc,%d] null pm", __LINE__)); 2316 2317 mode = PMC_TO_MODE(pm); 2318 ri = PMC_TO_ROWINDEX(pm); 2319 error = 0; 2320 2321 PMCDBG(PMC,OPS,1, "start pmc=%p mode=%d ri=%d", pm, mode, ri); 2322 2323 po = pm->pm_owner; 2324 2325 if (PMC_IS_VIRTUAL_MODE(mode)) { 2326 2327 /* 2328 * If a PMCATTACH has never been done on this PMC, 2329 * attach it to its owner process. 2330 */ 2331 2332 if (LIST_EMPTY(&pm->pm_targets)) 2333 error = (pm->pm_flags & PMC_F_ATTACH_DONE) ? ESRCH : 2334 pmc_attach_process(po->po_owner, pm); 2335 2336 /* 2337 * Disallow PMCSTART if a logfile is required but has not 2338 * been configured yet. 2339 */ 2340 2341 if (error == 0 && (pm->pm_flags & PMC_F_NEEDS_LOGFILE) && 2342 (po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) 2343 error = EDOOFUS; 2344 2345 /* 2346 * If the PMC is attached to its owner, then force a context 2347 * switch to ensure that the MD state gets set correctly. 2348 */ 2349 2350 if (error == 0) { 2351 pm->pm_state = PMC_STATE_RUNNING; 2352 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) 2353 pmc_force_context_switch(); 2354 } 2355 2356 return error; 2357 } 2358 2359 2360 /* 2361 * A system-wide PMC. 2362 */ 2363 2364 if ((pm->pm_flags & PMC_F_NEEDS_LOGFILE) && 2365 (po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) 2366 return EDOOFUS; /* programming error */ 2367 2368 /* 2369 * Add the owner to the global list if this is a system-wide 2370 * sampling PMC. 2371 */ 2372 2373 if (mode == PMC_MODE_SS) { 2374 if (po->po_sscount == 0) { 2375 LIST_INSERT_HEAD(&pmc_ss_owners, po, po_ssnext); 2376 atomic_add_rel_int(&pmc_ss_count, 1); 2377 PMCDBG(PMC,OPS,1, "po=%p in global list", po); 2378 } 2379 po->po_sscount++; 2380 } 2381 2382 /* TODO: dump system wide process mappings to the log? */ 2383 2384 /* 2385 * Move to the CPU associated with this 2386 * PMC, and start the hardware. 2387 */ 2388 2389 pmc_save_cpu_binding(&pb); 2390 2391 cpu = PMC_TO_CPU(pm); 2392 2393 if (pmc_cpu_is_disabled(cpu)) 2394 return ENXIO; 2395 2396 pmc_select_cpu(cpu); 2397 2398 /* 2399 * global PMCs are configured at allocation time 2400 * so write out the initial value and start the PMC. 2401 */ 2402 2403 pm->pm_state = PMC_STATE_RUNNING; 2404 2405 critical_enter(); 2406 if ((error = md->pmd_write_pmc(cpu, ri, 2407 PMC_IS_SAMPLING_MODE(mode) ? 2408 pm->pm_sc.pm_reloadcount : 2409 pm->pm_sc.pm_initial)) == 0) 2410 error = md->pmd_start_pmc(cpu, ri); 2411 critical_exit(); 2412 2413 pmc_restore_cpu_binding(&pb); 2414 2415 return error; 2416 } 2417 2418 /* 2419 * Stop a PMC. 2420 */ 2421 2422 static int 2423 pmc_stop(struct pmc *pm) 2424 { 2425 int cpu, error, ri; 2426 struct pmc_owner *po; 2427 struct pmc_binding pb; 2428 2429 KASSERT(pm != NULL, ("[pmc,%d] null pmc", __LINE__)); 2430 2431 PMCDBG(PMC,OPS,1, "stop pmc=%p mode=%d ri=%d", pm, 2432 PMC_TO_MODE(pm), PMC_TO_ROWINDEX(pm)); 2433 2434 pm->pm_state = PMC_STATE_STOPPED; 2435 2436 /* 2437 * If the PMC is a virtual mode one, changing the state to 2438 * non-RUNNING is enough to ensure that the PMC never gets 2439 * scheduled. 2440 * 2441 * If this PMC is current running on a CPU, then it will 2442 * handled correctly at the time its target process is context 2443 * switched out. 2444 */ 2445 2446 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 2447 return 0; 2448 2449 /* 2450 * A system-mode PMC. Move to the CPU associated with 2451 * this PMC, and stop the hardware. We update the 2452 * 'initial count' so that a subsequent PMCSTART will 2453 * resume counting from the current hardware count. 2454 */ 2455 2456 pmc_save_cpu_binding(&pb); 2457 2458 cpu = PMC_TO_CPU(pm); 2459 2460 KASSERT(cpu >= 0 && cpu < mp_ncpus, 2461 ("[pmc,%d] illegal cpu=%d", __LINE__, cpu)); 2462 2463 if (pmc_cpu_is_disabled(cpu)) 2464 return ENXIO; 2465 2466 pmc_select_cpu(cpu); 2467 2468 ri = PMC_TO_ROWINDEX(pm); 2469 2470 critical_enter(); 2471 if ((error = md->pmd_stop_pmc(cpu, ri)) == 0) 2472 error = md->pmd_read_pmc(cpu, ri, &pm->pm_sc.pm_initial); 2473 critical_exit(); 2474 2475 pmc_restore_cpu_binding(&pb); 2476 2477 po = pm->pm_owner; 2478 2479 /* remove this owner from the global list of SS PMC owners */ 2480 if (PMC_TO_MODE(pm) == PMC_MODE_SS) { 2481 po->po_sscount--; 2482 if (po->po_sscount == 0) { 2483 atomic_subtract_rel_int(&pmc_ss_count, 1); 2484 LIST_REMOVE(po, po_ssnext); 2485 PMCDBG(PMC,OPS,2,"po=%p removed from global list", po); 2486 } 2487 } 2488 2489 return error; 2490 } 2491 2492 2493 #ifdef DEBUG 2494 static const char *pmc_op_to_name[] = { 2495 #undef __PMC_OP 2496 #define __PMC_OP(N, D) #N , 2497 __PMC_OPS() 2498 NULL 2499 }; 2500 #endif 2501 2502 /* 2503 * The syscall interface 2504 */ 2505 2506 #define PMC_GET_SX_XLOCK(...) do { \ 2507 sx_xlock(&pmc_sx); \ 2508 if (pmc_hook == NULL) { \ 2509 sx_xunlock(&pmc_sx); \ 2510 return __VA_ARGS__; \ 2511 } \ 2512 } while (0) 2513 2514 #define PMC_DOWNGRADE_SX() do { \ 2515 sx_downgrade(&pmc_sx); \ 2516 is_sx_downgraded = 1; \ 2517 } while (0) 2518 2519 static int 2520 pmc_syscall_handler(struct thread *td, void *syscall_args) 2521 { 2522 int error, is_sx_downgraded, op; 2523 struct pmc_syscall_args *c; 2524 void *arg; 2525 2526 PMC_GET_SX_XLOCK(ENOSYS); 2527 2528 DROP_GIANT(); 2529 2530 is_sx_downgraded = 0; 2531 2532 c = (struct pmc_syscall_args *) syscall_args; 2533 2534 op = c->pmop_code; 2535 arg = c->pmop_data; 2536 2537 PMCDBG(MOD,PMS,1, "syscall op=%d \"%s\" arg=%p", op, 2538 pmc_op_to_name[op], arg); 2539 2540 error = 0; 2541 atomic_add_int(&pmc_stats.pm_syscalls, 1); 2542 2543 switch(op) 2544 { 2545 2546 2547 /* 2548 * Configure a log file. 2549 * 2550 * XXX This OP will be reworked. 2551 */ 2552 2553 case PMC_OP_CONFIGURELOG: 2554 { 2555 struct proc *p; 2556 struct pmc *pm; 2557 struct pmc_owner *po; 2558 struct pmckern_map_in *km, *kmbase; 2559 struct pmc_op_configurelog cl; 2560 2561 sx_assert(&pmc_sx, SX_XLOCKED); 2562 2563 if ((error = copyin(arg, &cl, sizeof(cl))) != 0) 2564 break; 2565 2566 /* mark this process as owning a log file */ 2567 p = td->td_proc; 2568 if ((po = pmc_find_owner_descriptor(p)) == NULL) 2569 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) { 2570 error = ENOMEM; 2571 break; 2572 } 2573 2574 /* 2575 * If a valid fd was passed in, try to configure that, 2576 * otherwise if 'fd' was less than zero and there was 2577 * a log file configured, flush its buffers and 2578 * de-configure it. 2579 */ 2580 if (cl.pm_logfd >= 0) 2581 error = pmclog_configure_log(po, cl.pm_logfd); 2582 else if (po->po_flags & PMC_PO_OWNS_LOGFILE) { 2583 pmclog_process_closelog(po); 2584 error = pmclog_flush(po); 2585 if (error == 0) { 2586 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 2587 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 2588 pm->pm_state == PMC_STATE_RUNNING) 2589 pmc_stop(pm); 2590 error = pmclog_deconfigure_log(po); 2591 } 2592 } else 2593 error = EINVAL; 2594 2595 if (error) 2596 break; 2597 2598 /* 2599 * Log the current set of kernel modules. 2600 */ 2601 kmbase = linker_hwpmc_list_objects(); 2602 for (km = kmbase; km->pm_file != NULL; km++) { 2603 PMCDBG(LOG,REG,1,"%s %p", (char *) km->pm_file, 2604 (void *) km->pm_address); 2605 pmclog_process_map_in(po, (pid_t) -1, km->pm_address, 2606 km->pm_file); 2607 } 2608 FREE(kmbase, M_LINKER); 2609 } 2610 break; 2611 2612 2613 /* 2614 * Flush a log file. 2615 */ 2616 2617 case PMC_OP_FLUSHLOG: 2618 { 2619 struct pmc_owner *po; 2620 2621 sx_assert(&pmc_sx, SX_XLOCKED); 2622 2623 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 2624 error = EINVAL; 2625 break; 2626 } 2627 2628 error = pmclog_flush(po); 2629 } 2630 break; 2631 2632 /* 2633 * Retrieve hardware configuration. 2634 */ 2635 2636 case PMC_OP_GETCPUINFO: /* CPU information */ 2637 { 2638 struct pmc_op_getcpuinfo gci; 2639 2640 gci.pm_cputype = md->pmd_cputype; 2641 gci.pm_ncpu = mp_ncpus; 2642 gci.pm_npmc = md->pmd_npmc; 2643 gci.pm_nclass = md->pmd_nclass; 2644 bcopy(md->pmd_classes, &gci.pm_classes, 2645 sizeof(gci.pm_classes)); 2646 error = copyout(&gci, arg, sizeof(gci)); 2647 } 2648 break; 2649 2650 2651 /* 2652 * Get module statistics 2653 */ 2654 2655 case PMC_OP_GETDRIVERSTATS: 2656 { 2657 struct pmc_op_getdriverstats gms; 2658 2659 bcopy(&pmc_stats, &gms, sizeof(gms)); 2660 error = copyout(&gms, arg, sizeof(gms)); 2661 } 2662 break; 2663 2664 2665 /* 2666 * Retrieve module version number 2667 */ 2668 2669 case PMC_OP_GETMODULEVERSION: 2670 { 2671 uint32_t cv, modv; 2672 2673 /* retrieve the client's idea of the ABI version */ 2674 if ((error = copyin(arg, &cv, sizeof(uint32_t))) != 0) 2675 break; 2676 /* don't service clients newer than our driver */ 2677 modv = PMC_VERSION; 2678 if ((cv & 0xFFFF0000) > (modv & 0xFFFF0000)) { 2679 error = EPROGMISMATCH; 2680 break; 2681 } 2682 error = copyout(&modv, arg, sizeof(int)); 2683 } 2684 break; 2685 2686 2687 /* 2688 * Retrieve the state of all the PMCs on a given 2689 * CPU. 2690 */ 2691 2692 case PMC_OP_GETPMCINFO: 2693 { 2694 uint32_t cpu, n, npmc; 2695 size_t pmcinfo_size; 2696 struct pmc *pm; 2697 struct pmc_info *p, *pmcinfo; 2698 struct pmc_op_getpmcinfo *gpi; 2699 struct pmc_owner *po; 2700 struct pmc_binding pb; 2701 2702 PMC_DOWNGRADE_SX(); 2703 2704 gpi = (struct pmc_op_getpmcinfo *) arg; 2705 2706 if ((error = copyin(&gpi->pm_cpu, &cpu, sizeof(cpu))) != 0) 2707 break; 2708 2709 if (cpu >= (unsigned int) mp_ncpus) { 2710 error = EINVAL; 2711 break; 2712 } 2713 2714 if (pmc_cpu_is_disabled(cpu)) { 2715 error = ENXIO; 2716 break; 2717 } 2718 2719 /* switch to CPU 'cpu' */ 2720 pmc_save_cpu_binding(&pb); 2721 pmc_select_cpu(cpu); 2722 2723 npmc = md->pmd_npmc; 2724 2725 pmcinfo_size = npmc * sizeof(struct pmc_info); 2726 MALLOC(pmcinfo, struct pmc_info *, pmcinfo_size, M_PMC, 2727 M_WAITOK); 2728 2729 p = pmcinfo; 2730 2731 for (n = 0; n < md->pmd_npmc; n++, p++) { 2732 2733 if ((error = md->pmd_describe(cpu, n, p, &pm)) != 0) 2734 break; 2735 2736 if (PMC_ROW_DISP_IS_STANDALONE(n)) 2737 p->pm_rowdisp = PMC_DISP_STANDALONE; 2738 else if (PMC_ROW_DISP_IS_THREAD(n)) 2739 p->pm_rowdisp = PMC_DISP_THREAD; 2740 else 2741 p->pm_rowdisp = PMC_DISP_FREE; 2742 2743 p->pm_ownerpid = -1; 2744 2745 if (pm == NULL) /* no PMC associated */ 2746 continue; 2747 2748 po = pm->pm_owner; 2749 2750 KASSERT(po->po_owner != NULL, 2751 ("[pmc,%d] pmc_owner had a null proc pointer", 2752 __LINE__)); 2753 2754 p->pm_ownerpid = po->po_owner->p_pid; 2755 p->pm_mode = PMC_TO_MODE(pm); 2756 p->pm_event = pm->pm_event; 2757 p->pm_flags = pm->pm_flags; 2758 2759 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 2760 p->pm_reloadcount = 2761 pm->pm_sc.pm_reloadcount; 2762 } 2763 2764 pmc_restore_cpu_binding(&pb); 2765 2766 /* now copy out the PMC info collected */ 2767 if (error == 0) 2768 error = copyout(pmcinfo, &gpi->pm_pmcs, pmcinfo_size); 2769 2770 FREE(pmcinfo, M_PMC); 2771 } 2772 break; 2773 2774 2775 /* 2776 * Set the administrative state of a PMC. I.e. whether 2777 * the PMC is to be used or not. 2778 */ 2779 2780 case PMC_OP_PMCADMIN: 2781 { 2782 int cpu, ri; 2783 enum pmc_state request; 2784 struct pmc_cpu *pc; 2785 struct pmc_hw *phw; 2786 struct pmc_op_pmcadmin pma; 2787 struct pmc_binding pb; 2788 2789 sx_assert(&pmc_sx, SX_XLOCKED); 2790 2791 KASSERT(td == curthread, 2792 ("[pmc,%d] td != curthread", __LINE__)); 2793 2794 if (suser(td) || jailed(td->td_ucred)) { 2795 error = EPERM; 2796 break; 2797 } 2798 2799 if ((error = copyin(arg, &pma, sizeof(pma))) != 0) 2800 break; 2801 2802 cpu = pma.pm_cpu; 2803 2804 if (cpu < 0 || cpu >= mp_ncpus) { 2805 error = EINVAL; 2806 break; 2807 } 2808 2809 if (pmc_cpu_is_disabled(cpu)) { 2810 error = ENXIO; 2811 break; 2812 } 2813 2814 request = pma.pm_state; 2815 2816 if (request != PMC_STATE_DISABLED && 2817 request != PMC_STATE_FREE) { 2818 error = EINVAL; 2819 break; 2820 } 2821 2822 ri = pma.pm_pmc; /* pmc id == row index */ 2823 if (ri < 0 || ri >= (int) md->pmd_npmc) { 2824 error = EINVAL; 2825 break; 2826 } 2827 2828 /* 2829 * We can't disable a PMC with a row-index allocated 2830 * for process virtual PMCs. 2831 */ 2832 2833 if (PMC_ROW_DISP_IS_THREAD(ri) && 2834 request == PMC_STATE_DISABLED) { 2835 error = EBUSY; 2836 break; 2837 } 2838 2839 /* 2840 * otherwise, this PMC on this CPU is either free or 2841 * in system-wide mode. 2842 */ 2843 2844 pmc_save_cpu_binding(&pb); 2845 pmc_select_cpu(cpu); 2846 2847 pc = pmc_pcpu[cpu]; 2848 phw = pc->pc_hwpmcs[ri]; 2849 2850 /* 2851 * XXX do we need some kind of 'forced' disable? 2852 */ 2853 2854 if (phw->phw_pmc == NULL) { 2855 if (request == PMC_STATE_DISABLED && 2856 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED)) { 2857 phw->phw_state &= ~PMC_PHW_FLAG_IS_ENABLED; 2858 PMC_MARK_ROW_STANDALONE(ri); 2859 } else if (request == PMC_STATE_FREE && 2860 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0) { 2861 phw->phw_state |= PMC_PHW_FLAG_IS_ENABLED; 2862 PMC_UNMARK_ROW_STANDALONE(ri); 2863 } 2864 /* other cases are a no-op */ 2865 } else 2866 error = EBUSY; 2867 2868 pmc_restore_cpu_binding(&pb); 2869 } 2870 break; 2871 2872 2873 /* 2874 * Allocate a PMC. 2875 */ 2876 2877 case PMC_OP_PMCALLOCATE: 2878 { 2879 uint32_t caps; 2880 u_int cpu; 2881 int n; 2882 enum pmc_mode mode; 2883 struct pmc *pmc; 2884 struct pmc_hw *phw; 2885 struct pmc_op_pmcallocate pa; 2886 struct pmc_binding pb; 2887 2888 if ((error = copyin(arg, &pa, sizeof(pa))) != 0) 2889 break; 2890 2891 caps = pa.pm_caps; 2892 mode = pa.pm_mode; 2893 cpu = pa.pm_cpu; 2894 2895 if ((mode != PMC_MODE_SS && mode != PMC_MODE_SC && 2896 mode != PMC_MODE_TS && mode != PMC_MODE_TC) || 2897 (cpu != (u_int) PMC_CPU_ANY && cpu >= (u_int) mp_ncpus)) { 2898 error = EINVAL; 2899 break; 2900 } 2901 2902 /* 2903 * Virtual PMCs should only ask for a default CPU. 2904 * System mode PMCs need to specify a non-default CPU. 2905 */ 2906 2907 if ((PMC_IS_VIRTUAL_MODE(mode) && cpu != (u_int) PMC_CPU_ANY) || 2908 (PMC_IS_SYSTEM_MODE(mode) && cpu == (u_int) PMC_CPU_ANY)) { 2909 error = EINVAL; 2910 break; 2911 } 2912 2913 /* 2914 * Check that a disabled CPU is not being asked for. 2915 */ 2916 2917 if (PMC_IS_SYSTEM_MODE(mode) && pmc_cpu_is_disabled(cpu)) { 2918 error = ENXIO; 2919 break; 2920 } 2921 2922 /* 2923 * Refuse an allocation for a system-wide PMC if this 2924 * process has been jailed, or if this process lacks 2925 * super-user credentials and the sysctl tunable 2926 * 'security.bsd.unprivileged_syspmcs' is zero. 2927 */ 2928 2929 if (PMC_IS_SYSTEM_MODE(mode)) { 2930 if (jailed(curthread->td_ucred)) 2931 error = EPERM; 2932 else if (suser(curthread) && 2933 (pmc_unprivileged_syspmcs == 0)) 2934 error = EPERM; 2935 } 2936 2937 if (error) 2938 break; 2939 2940 /* 2941 * Look for valid values for 'pm_flags' 2942 */ 2943 2944 if ((pa.pm_flags & ~(PMC_F_DESCENDANTS | PMC_F_LOG_PROCCSW | 2945 PMC_F_LOG_PROCEXIT)) != 0) { 2946 error = EINVAL; 2947 break; 2948 } 2949 2950 /* process logging options are not allowed for system PMCs */ 2951 if (PMC_IS_SYSTEM_MODE(mode) && (pa.pm_flags & 2952 (PMC_F_LOG_PROCCSW | PMC_F_LOG_PROCEXIT))) { 2953 error = EINVAL; 2954 break; 2955 } 2956 2957 /* 2958 * All sampling mode PMCs need to be able to interrupt the 2959 * CPU. 2960 */ 2961 if (PMC_IS_SAMPLING_MODE(mode)) 2962 caps |= PMC_CAP_INTERRUPT; 2963 2964 /* A valid class specifier should have been passed in. */ 2965 for (n = 0; n < md->pmd_nclass; n++) 2966 if (md->pmd_classes[n].pm_class == pa.pm_class) 2967 break; 2968 if (n == md->pmd_nclass) { 2969 error = EINVAL; 2970 break; 2971 } 2972 2973 /* The requested PMC capabilities should be feasible. */ 2974 if ((md->pmd_classes[n].pm_caps & caps) != caps) { 2975 error = EOPNOTSUPP; 2976 break; 2977 } 2978 2979 PMCDBG(PMC,ALL,2, "event=%d caps=0x%x mode=%d cpu=%d", 2980 pa.pm_ev, caps, mode, cpu); 2981 2982 pmc = pmc_allocate_pmc_descriptor(); 2983 pmc->pm_id = PMC_ID_MAKE_ID(cpu,pa.pm_mode,pa.pm_class, 2984 PMC_ID_INVALID); 2985 pmc->pm_event = pa.pm_ev; 2986 pmc->pm_state = PMC_STATE_FREE; 2987 pmc->pm_caps = caps; 2988 pmc->pm_flags = pa.pm_flags; 2989 2990 /* switch thread to CPU 'cpu' */ 2991 pmc_save_cpu_binding(&pb); 2992 2993 #define PMC_IS_SHAREABLE_PMC(cpu, n) \ 2994 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_state & \ 2995 PMC_PHW_FLAG_IS_SHAREABLE) 2996 #define PMC_IS_UNALLOCATED(cpu, n) \ 2997 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_pmc == NULL) 2998 2999 if (PMC_IS_SYSTEM_MODE(mode)) { 3000 pmc_select_cpu(cpu); 3001 for (n = 0; n < (int) md->pmd_npmc; n++) 3002 if (pmc_can_allocate_row(n, mode) == 0 && 3003 pmc_can_allocate_rowindex( 3004 curthread->td_proc, n, cpu) == 0 && 3005 (PMC_IS_UNALLOCATED(cpu, n) || 3006 PMC_IS_SHAREABLE_PMC(cpu, n)) && 3007 md->pmd_allocate_pmc(cpu, n, pmc, 3008 &pa) == 0) 3009 break; 3010 } else { 3011 /* Process virtual mode */ 3012 for (n = 0; n < (int) md->pmd_npmc; n++) { 3013 if (pmc_can_allocate_row(n, mode) == 0 && 3014 pmc_can_allocate_rowindex( 3015 curthread->td_proc, n, 3016 PMC_CPU_ANY) == 0 && 3017 md->pmd_allocate_pmc(curthread->td_oncpu, 3018 n, pmc, &pa) == 0) 3019 break; 3020 } 3021 } 3022 3023 #undef PMC_IS_UNALLOCATED 3024 #undef PMC_IS_SHAREABLE_PMC 3025 3026 pmc_restore_cpu_binding(&pb); 3027 3028 if (n == (int) md->pmd_npmc) { 3029 pmc_destroy_pmc_descriptor(pmc); 3030 FREE(pmc, M_PMC); 3031 pmc = NULL; 3032 error = EINVAL; 3033 break; 3034 } 3035 3036 /* Fill in the correct value in the ID field */ 3037 pmc->pm_id = PMC_ID_MAKE_ID(cpu,mode,pa.pm_class,n); 3038 3039 PMCDBG(PMC,ALL,2, "ev=%d class=%d mode=%d n=%d -> pmcid=%x", 3040 pmc->pm_event, pa.pm_class, mode, n, pmc->pm_id); 3041 3042 /* Process mode PMCs with logging enabled need log files */ 3043 if (pmc->pm_flags & (PMC_F_LOG_PROCEXIT | PMC_F_LOG_PROCCSW)) 3044 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3045 3046 /* All system mode sampling PMCs require a log file */ 3047 if (PMC_IS_SAMPLING_MODE(mode) && PMC_IS_SYSTEM_MODE(mode)) 3048 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3049 3050 /* 3051 * Configure global pmc's immediately 3052 */ 3053 3054 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pmc))) { 3055 3056 pmc_save_cpu_binding(&pb); 3057 pmc_select_cpu(cpu); 3058 3059 phw = pmc_pcpu[cpu]->pc_hwpmcs[n]; 3060 3061 if ((phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0 || 3062 (error = md->pmd_config_pmc(cpu, n, pmc)) != 0) { 3063 (void) md->pmd_release_pmc(cpu, n, pmc); 3064 pmc_destroy_pmc_descriptor(pmc); 3065 FREE(pmc, M_PMC); 3066 pmc = NULL; 3067 pmc_restore_cpu_binding(&pb); 3068 error = EPERM; 3069 break; 3070 } 3071 3072 pmc_restore_cpu_binding(&pb); 3073 } 3074 3075 pmc->pm_state = PMC_STATE_ALLOCATED; 3076 3077 /* 3078 * mark row disposition 3079 */ 3080 3081 if (PMC_IS_SYSTEM_MODE(mode)) 3082 PMC_MARK_ROW_STANDALONE(n); 3083 else 3084 PMC_MARK_ROW_THREAD(n); 3085 3086 /* 3087 * Register this PMC with the current thread as its owner. 3088 */ 3089 3090 if ((error = 3091 pmc_register_owner(curthread->td_proc, pmc)) != 0) { 3092 pmc_release_pmc_descriptor(pmc); 3093 FREE(pmc, M_PMC); 3094 pmc = NULL; 3095 break; 3096 } 3097 3098 /* 3099 * Return the allocated index. 3100 */ 3101 3102 pa.pm_pmcid = pmc->pm_id; 3103 3104 error = copyout(&pa, arg, sizeof(pa)); 3105 } 3106 break; 3107 3108 3109 /* 3110 * Attach a PMC to a process. 3111 */ 3112 3113 case PMC_OP_PMCATTACH: 3114 { 3115 struct pmc *pm; 3116 struct proc *p; 3117 struct pmc_op_pmcattach a; 3118 3119 sx_assert(&pmc_sx, SX_XLOCKED); 3120 3121 if ((error = copyin(arg, &a, sizeof(a))) != 0) 3122 break; 3123 3124 if (a.pm_pid < 0) { 3125 error = EINVAL; 3126 break; 3127 } else if (a.pm_pid == 0) 3128 a.pm_pid = td->td_proc->p_pid; 3129 3130 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 3131 break; 3132 3133 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) { 3134 error = EINVAL; 3135 break; 3136 } 3137 3138 /* PMCs may be (re)attached only when allocated or stopped */ 3139 if (pm->pm_state == PMC_STATE_RUNNING) { 3140 error = EBUSY; 3141 break; 3142 } else if (pm->pm_state != PMC_STATE_ALLOCATED && 3143 pm->pm_state != PMC_STATE_STOPPED) { 3144 error = EINVAL; 3145 break; 3146 } 3147 3148 /* lookup pid */ 3149 if ((p = pfind(a.pm_pid)) == NULL) { 3150 error = ESRCH; 3151 break; 3152 } 3153 3154 /* 3155 * Ignore processes that are working on exiting. 3156 */ 3157 if (p->p_flag & P_WEXIT) { 3158 error = ESRCH; 3159 PROC_UNLOCK(p); /* pfind() returns a locked process */ 3160 break; 3161 } 3162 3163 /* 3164 * we are allowed to attach a PMC to a process if 3165 * we can debug it. 3166 */ 3167 error = p_candebug(curthread, p); 3168 3169 PROC_UNLOCK(p); 3170 3171 if (error == 0) 3172 error = pmc_attach_process(p, pm); 3173 } 3174 break; 3175 3176 3177 /* 3178 * Detach an attached PMC from a process. 3179 */ 3180 3181 case PMC_OP_PMCDETACH: 3182 { 3183 struct pmc *pm; 3184 struct proc *p; 3185 struct pmc_op_pmcattach a; 3186 3187 if ((error = copyin(arg, &a, sizeof(a))) != 0) 3188 break; 3189 3190 if (a.pm_pid < 0) { 3191 error = EINVAL; 3192 break; 3193 } else if (a.pm_pid == 0) 3194 a.pm_pid = td->td_proc->p_pid; 3195 3196 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 3197 break; 3198 3199 if ((p = pfind(a.pm_pid)) == NULL) { 3200 error = ESRCH; 3201 break; 3202 } 3203 3204 /* 3205 * Treat processes that are in the process of exiting 3206 * as if they were not present. 3207 */ 3208 3209 if (p->p_flag & P_WEXIT) 3210 error = ESRCH; 3211 3212 PROC_UNLOCK(p); /* pfind() returns a locked process */ 3213 3214 if (error == 0) 3215 error = pmc_detach_process(p, pm); 3216 } 3217 break; 3218 3219 3220 /* 3221 * Retrieve the MSR number associated with the counter 3222 * 'pmc_id'. This allows processes to directly use RDPMC 3223 * instructions to read their PMCs, without the overhead of a 3224 * system call. 3225 */ 3226 3227 case PMC_OP_PMCGETMSR: 3228 { 3229 int ri; 3230 struct pmc *pm; 3231 struct pmc_target *pt; 3232 struct pmc_op_getmsr gm; 3233 3234 PMC_DOWNGRADE_SX(); 3235 3236 /* CPU has no 'GETMSR' support */ 3237 if (md->pmd_get_msr == NULL) { 3238 error = ENOSYS; 3239 break; 3240 } 3241 3242 if ((error = copyin(arg, &gm, sizeof(gm))) != 0) 3243 break; 3244 3245 if ((error = pmc_find_pmc(gm.pm_pmcid, &pm)) != 0) 3246 break; 3247 3248 /* 3249 * The allocated PMC has to be a process virtual PMC, 3250 * i.e., of type MODE_T[CS]. Global PMCs can only be 3251 * read using the PMCREAD operation since they may be 3252 * allocated on a different CPU than the one we could 3253 * be running on at the time of the RDPMC instruction. 3254 * 3255 * The GETMSR operation is not allowed for PMCs that 3256 * are inherited across processes. 3257 */ 3258 3259 if (!PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)) || 3260 (pm->pm_flags & PMC_F_DESCENDANTS)) { 3261 error = EINVAL; 3262 break; 3263 } 3264 3265 /* 3266 * It only makes sense to use a RDPMC (or its 3267 * equivalent instruction on non-x86 architectures) on 3268 * a process that has allocated and attached a PMC to 3269 * itself. Conversely the PMC is only allowed to have 3270 * one process attached to it -- its owner. 3271 */ 3272 3273 if ((pt = LIST_FIRST(&pm->pm_targets)) == NULL || 3274 LIST_NEXT(pt, pt_next) != NULL || 3275 pt->pt_process->pp_proc != pm->pm_owner->po_owner) { 3276 error = EINVAL; 3277 break; 3278 } 3279 3280 ri = PMC_TO_ROWINDEX(pm); 3281 3282 if ((error = (*md->pmd_get_msr)(ri, &gm.pm_msr)) < 0) 3283 break; 3284 3285 if ((error = copyout(&gm, arg, sizeof(gm))) < 0) 3286 break; 3287 3288 /* 3289 * Mark our process as using MSRs. Update machine 3290 * state using a forced context switch. 3291 */ 3292 3293 pt->pt_process->pp_flags |= PMC_PP_ENABLE_MSR_ACCESS; 3294 pmc_force_context_switch(); 3295 3296 } 3297 break; 3298 3299 /* 3300 * Release an allocated PMC 3301 */ 3302 3303 case PMC_OP_PMCRELEASE: 3304 { 3305 pmc_id_t pmcid; 3306 struct pmc *pm; 3307 struct pmc_owner *po; 3308 struct pmc_op_simple sp; 3309 3310 /* 3311 * Find PMC pointer for the named PMC. 3312 * 3313 * Use pmc_release_pmc_descriptor() to switch off the 3314 * PMC, remove all its target threads, and remove the 3315 * PMC from its owner's list. 3316 * 3317 * Remove the owner record if this is the last PMC 3318 * owned. 3319 * 3320 * Free up space. 3321 */ 3322 3323 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3324 break; 3325 3326 pmcid = sp.pm_pmcid; 3327 3328 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3329 break; 3330 3331 po = pm->pm_owner; 3332 pmc_release_pmc_descriptor(pm); 3333 pmc_maybe_remove_owner(po); 3334 3335 FREE(pm, M_PMC); 3336 } 3337 break; 3338 3339 3340 /* 3341 * Read and/or write a PMC. 3342 */ 3343 3344 case PMC_OP_PMCRW: 3345 { 3346 uint32_t cpu, ri; 3347 struct pmc *pm; 3348 struct pmc_op_pmcrw *pprw; 3349 struct pmc_op_pmcrw prw; 3350 struct pmc_binding pb; 3351 pmc_value_t oldvalue; 3352 3353 PMC_DOWNGRADE_SX(); 3354 3355 if ((error = copyin(arg, &prw, sizeof(prw))) != 0) 3356 break; 3357 3358 ri = 0; 3359 PMCDBG(PMC,OPS,1, "rw id=%d flags=0x%x", prw.pm_pmcid, 3360 prw.pm_flags); 3361 3362 /* must have at least one flag set */ 3363 if ((prw.pm_flags & (PMC_F_OLDVALUE|PMC_F_NEWVALUE)) == 0) { 3364 error = EINVAL; 3365 break; 3366 } 3367 3368 /* locate pmc descriptor */ 3369 if ((error = pmc_find_pmc(prw.pm_pmcid, &pm)) != 0) 3370 break; 3371 3372 /* Can't read a PMC that hasn't been started. */ 3373 if (pm->pm_state != PMC_STATE_ALLOCATED && 3374 pm->pm_state != PMC_STATE_STOPPED && 3375 pm->pm_state != PMC_STATE_RUNNING) { 3376 error = EINVAL; 3377 break; 3378 } 3379 3380 /* writing a new value is allowed only for 'STOPPED' pmcs */ 3381 if (pm->pm_state == PMC_STATE_RUNNING && 3382 (prw.pm_flags & PMC_F_NEWVALUE)) { 3383 error = EBUSY; 3384 break; 3385 } 3386 3387 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) { 3388 3389 /* 3390 * If this PMC is attached to its owner (i.e., 3391 * the process requesting this operation) and 3392 * is running, then attempt to get an 3393 * upto-date reading from hardware for a READ. 3394 * Writes are only allowed when the PMC is 3395 * stopped, so only update the saved value 3396 * field. 3397 * 3398 * If the PMC is not running, or is not 3399 * attached to its owner, read/write to the 3400 * savedvalue field. 3401 */ 3402 3403 ri = PMC_TO_ROWINDEX(pm); 3404 3405 mtx_pool_lock_spin(pmc_mtxpool, pm); 3406 cpu = curthread->td_oncpu; 3407 3408 if (prw.pm_flags & PMC_F_OLDVALUE) { 3409 if ((pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) && 3410 (pm->pm_state == PMC_STATE_RUNNING)) 3411 error = (*md->pmd_read_pmc)(cpu, ri, 3412 &oldvalue); 3413 else 3414 oldvalue = pm->pm_gv.pm_savedvalue; 3415 } 3416 if (prw.pm_flags & PMC_F_NEWVALUE) 3417 pm->pm_gv.pm_savedvalue = prw.pm_value; 3418 3419 mtx_pool_unlock_spin(pmc_mtxpool, pm); 3420 3421 } else { /* System mode PMCs */ 3422 cpu = PMC_TO_CPU(pm); 3423 ri = PMC_TO_ROWINDEX(pm); 3424 3425 if (pmc_cpu_is_disabled(cpu)) { 3426 error = ENXIO; 3427 break; 3428 } 3429 3430 /* move this thread to CPU 'cpu' */ 3431 pmc_save_cpu_binding(&pb); 3432 pmc_select_cpu(cpu); 3433 3434 critical_enter(); 3435 /* save old value */ 3436 if (prw.pm_flags & PMC_F_OLDVALUE) 3437 if ((error = (*md->pmd_read_pmc)(cpu, ri, 3438 &oldvalue))) 3439 goto error; 3440 /* write out new value */ 3441 if (prw.pm_flags & PMC_F_NEWVALUE) 3442 error = (*md->pmd_write_pmc)(cpu, ri, 3443 prw.pm_value); 3444 error: 3445 critical_exit(); 3446 pmc_restore_cpu_binding(&pb); 3447 if (error) 3448 break; 3449 } 3450 3451 pprw = (struct pmc_op_pmcrw *) arg; 3452 3453 #ifdef DEBUG 3454 if (prw.pm_flags & PMC_F_NEWVALUE) 3455 PMCDBG(PMC,OPS,2, "rw id=%d new %jx -> old %jx", 3456 ri, prw.pm_value, oldvalue); 3457 else if (prw.pm_flags & PMC_F_OLDVALUE) 3458 PMCDBG(PMC,OPS,2, "rw id=%d -> old %jx", ri, oldvalue); 3459 #endif 3460 3461 /* return old value if requested */ 3462 if (prw.pm_flags & PMC_F_OLDVALUE) 3463 if ((error = copyout(&oldvalue, &pprw->pm_value, 3464 sizeof(prw.pm_value)))) 3465 break; 3466 3467 } 3468 break; 3469 3470 3471 /* 3472 * Set the sampling rate for a sampling mode PMC and the 3473 * initial count for a counting mode PMC. 3474 */ 3475 3476 case PMC_OP_PMCSETCOUNT: 3477 { 3478 struct pmc *pm; 3479 struct pmc_op_pmcsetcount sc; 3480 3481 PMC_DOWNGRADE_SX(); 3482 3483 if ((error = copyin(arg, &sc, sizeof(sc))) != 0) 3484 break; 3485 3486 if ((error = pmc_find_pmc(sc.pm_pmcid, &pm)) != 0) 3487 break; 3488 3489 if (pm->pm_state == PMC_STATE_RUNNING) { 3490 error = EBUSY; 3491 break; 3492 } 3493 3494 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 3495 pm->pm_sc.pm_reloadcount = sc.pm_count; 3496 else 3497 pm->pm_sc.pm_initial = sc.pm_count; 3498 } 3499 break; 3500 3501 3502 /* 3503 * Start a PMC. 3504 */ 3505 3506 case PMC_OP_PMCSTART: 3507 { 3508 pmc_id_t pmcid; 3509 struct pmc *pm; 3510 struct pmc_op_simple sp; 3511 3512 sx_assert(&pmc_sx, SX_XLOCKED); 3513 3514 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3515 break; 3516 3517 pmcid = sp.pm_pmcid; 3518 3519 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3520 break; 3521 3522 KASSERT(pmcid == pm->pm_id, 3523 ("[pmc,%d] pmcid %x != id %x", __LINE__, 3524 pm->pm_id, pmcid)); 3525 3526 if (pm->pm_state == PMC_STATE_RUNNING) /* already running */ 3527 break; 3528 else if (pm->pm_state != PMC_STATE_STOPPED && 3529 pm->pm_state != PMC_STATE_ALLOCATED) { 3530 error = EINVAL; 3531 break; 3532 } 3533 3534 error = pmc_start(pm); 3535 } 3536 break; 3537 3538 3539 /* 3540 * Stop a PMC. 3541 */ 3542 3543 case PMC_OP_PMCSTOP: 3544 { 3545 pmc_id_t pmcid; 3546 struct pmc *pm; 3547 struct pmc_op_simple sp; 3548 3549 PMC_DOWNGRADE_SX(); 3550 3551 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3552 break; 3553 3554 pmcid = sp.pm_pmcid; 3555 3556 /* 3557 * Mark the PMC as inactive and invoke the MD stop 3558 * routines if needed. 3559 */ 3560 3561 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3562 break; 3563 3564 KASSERT(pmcid == pm->pm_id, 3565 ("[pmc,%d] pmc id %x != pmcid %x", __LINE__, 3566 pm->pm_id, pmcid)); 3567 3568 if (pm->pm_state == PMC_STATE_STOPPED) /* already stopped */ 3569 break; 3570 else if (pm->pm_state != PMC_STATE_RUNNING) { 3571 error = EINVAL; 3572 break; 3573 } 3574 3575 error = pmc_stop(pm); 3576 } 3577 break; 3578 3579 3580 /* 3581 * Write a user supplied value to the log file. 3582 */ 3583 3584 case PMC_OP_WRITELOG: 3585 { 3586 struct pmc_op_writelog wl; 3587 struct pmc_owner *po; 3588 3589 PMC_DOWNGRADE_SX(); 3590 3591 if ((error = copyin(arg, &wl, sizeof(wl))) != 0) 3592 break; 3593 3594 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 3595 error = EINVAL; 3596 break; 3597 } 3598 3599 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) { 3600 error = EINVAL; 3601 break; 3602 } 3603 3604 error = pmclog_process_userlog(po, &wl); 3605 } 3606 break; 3607 3608 3609 default: 3610 error = EINVAL; 3611 break; 3612 } 3613 3614 if (is_sx_downgraded) 3615 sx_sunlock(&pmc_sx); 3616 else 3617 sx_xunlock(&pmc_sx); 3618 3619 if (error) 3620 atomic_add_int(&pmc_stats.pm_syscall_errors, 1); 3621 3622 PICKUP_GIANT(); 3623 3624 return error; 3625 } 3626 3627 /* 3628 * Helper functions 3629 */ 3630 3631 3632 /* 3633 * Interrupt processing. 3634 * 3635 * Find a free slot in the per-cpu array of PC samples and write the 3636 * current (PMC,PID,PC) triple to it. If an event was successfully 3637 * added, a bit is set in mask 'pmc_cpumask' denoting that the 3638 * DO_SAMPLES hook needs to be invoked from the clock handler. 3639 * 3640 * This function is meant to be called from an NMI handler. It cannot 3641 * use any of the locking primitives supplied by the OS. 3642 */ 3643 3644 int 3645 pmc_process_interrupt(int cpu, struct pmc *pm, uintfptr_t pc, int usermode) 3646 { 3647 int error, ri; 3648 struct thread *td; 3649 struct pmc_sample *ps; 3650 struct pmc_samplebuffer *psb; 3651 3652 error = 0; 3653 ri = PMC_TO_ROWINDEX(pm); 3654 3655 psb = pmc_pcpu[cpu]->pc_sb; 3656 3657 ps = psb->ps_write; 3658 if (ps->ps_pc) { /* in use, reader hasn't caught up */ 3659 pm->pm_stalled = 1; 3660 atomic_add_int(&pmc_stats.pm_intr_bufferfull, 1); 3661 PMCDBG(SAM,INT,1,"(spc) cpu=%d pm=%p pc=%jx um=%d wr=%d rd=%d", 3662 cpu, pm, (uint64_t) pc, usermode, 3663 (int) (psb->ps_write - psb->ps_samples), 3664 (int) (psb->ps_read - psb->ps_samples)); 3665 error = ENOMEM; 3666 goto done; 3667 } 3668 3669 /* fill in entry */ 3670 PMCDBG(SAM,INT,1,"cpu=%d pm=%p pc=%jx um=%d wr=%d rd=%d", cpu, pm, 3671 (uint64_t) pc, usermode, 3672 (int) (psb->ps_write - psb->ps_samples), 3673 (int) (psb->ps_read - psb->ps_samples)); 3674 3675 atomic_add_rel_32(&pm->pm_runcount, 1); /* hold onto PMC */ 3676 ps->ps_pmc = pm; 3677 if ((td = curthread) && td->td_proc) 3678 ps->ps_pid = td->td_proc->p_pid; 3679 else 3680 ps->ps_pid = -1; 3681 ps->ps_usermode = usermode; 3682 ps->ps_pc = pc; /* mark entry as in use */ 3683 3684 /* increment write pointer, modulo ring buffer size */ 3685 ps++; 3686 if (ps == psb->ps_fence) 3687 psb->ps_write = psb->ps_samples; 3688 else 3689 psb->ps_write = ps; 3690 3691 done: 3692 /* mark CPU as needing processing */ 3693 atomic_set_rel_int(&pmc_cpumask, (1 << cpu)); 3694 3695 return error; 3696 } 3697 3698 3699 /* 3700 * Process saved PC samples. 3701 */ 3702 3703 static void 3704 pmc_process_samples(int cpu) 3705 { 3706 int n, ri; 3707 struct pmc *pm; 3708 struct thread *td; 3709 struct pmc_owner *po; 3710 struct pmc_sample *ps; 3711 struct pmc_samplebuffer *psb; 3712 3713 KASSERT(PCPU_GET(cpuid) == cpu, 3714 ("[pmc,%d] not on the correct CPU pcpu=%d cpu=%d", __LINE__, 3715 PCPU_GET(cpuid), cpu)); 3716 3717 psb = pmc_pcpu[cpu]->pc_sb; 3718 3719 for (n = 0; n < pmc_nsamples; n++) { /* bound on #iterations */ 3720 3721 ps = psb->ps_read; 3722 if (ps->ps_pc == (uintfptr_t) 0) /* no data */ 3723 break; 3724 3725 pm = ps->ps_pmc; 3726 po = pm->pm_owner; 3727 3728 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 3729 ("[pmc,%d] pmc=%p non-sampling mode=%d", __LINE__, 3730 pm, PMC_TO_MODE(pm))); 3731 3732 /* Ignore PMCs that have been switched off */ 3733 if (pm->pm_state != PMC_STATE_RUNNING) 3734 goto entrydone; 3735 3736 PMCDBG(SAM,OPS,1,"cpu=%d pm=%p pc=%jx um=%d wr=%d rd=%d", cpu, 3737 pm, (uint64_t) ps->ps_pc, ps->ps_usermode, 3738 (int) (psb->ps_write - psb->ps_samples), 3739 (int) (psb->ps_read - psb->ps_samples)); 3740 3741 /* 3742 * If this is a process-mode PMC that is attached to 3743 * its owner, and if the PC is in user mode, update 3744 * profiling statistics like timer-based profiling 3745 * would have done. 3746 */ 3747 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) { 3748 if (ps->ps_usermode) { 3749 td = FIRST_THREAD_IN_PROC(po->po_owner); 3750 addupc_intr(td, ps->ps_pc, 1); 3751 } 3752 goto entrydone; 3753 } 3754 3755 /* 3756 * Otherwise, this is either a sampling mode PMC that 3757 * is attached to a different process than its owner, 3758 * or a system-wide sampling PMC. Dispatch a log 3759 * entry to the PMC's owner process. 3760 */ 3761 3762 pmclog_process_pcsample(pm, ps); 3763 3764 entrydone: 3765 ps->ps_pc = (uintfptr_t) 0; /* mark entry as free */ 3766 atomic_subtract_rel_32(&pm->pm_runcount, 1); 3767 3768 /* increment read pointer, modulo sample size */ 3769 if (++ps == psb->ps_fence) 3770 psb->ps_read = psb->ps_samples; 3771 else 3772 psb->ps_read = ps; 3773 } 3774 3775 atomic_add_int(&pmc_stats.pm_log_sweeps, 1); 3776 3777 /* Do not re-enable stalled PMCs if we failed to process any samples */ 3778 if (n == 0) 3779 return; 3780 3781 /* 3782 * Restart any stalled sampling PMCs on this CPU. 3783 * 3784 * If the NMI handler sets the pm_stalled field of a PMC after 3785 * the check below, we'll end up processing the stalled PMC at 3786 * the next hardclock tick. 3787 */ 3788 for (n = 0; n < md->pmd_npmc; n++) { 3789 (void) (*md->pmd_get_config)(cpu,n,&pm); 3790 if (pm == NULL || /* !cfg'ed */ 3791 pm->pm_state != PMC_STATE_RUNNING || /* !active */ 3792 !PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) || /* !sampling */ 3793 pm->pm_stalled == 0) /* !stalled */ 3794 continue; 3795 3796 pm->pm_stalled = 0; 3797 ri = PMC_TO_ROWINDEX(pm); 3798 (*md->pmd_start_pmc)(cpu, ri); 3799 } 3800 } 3801 3802 /* 3803 * Event handlers. 3804 */ 3805 3806 /* 3807 * Handle a process exit. 3808 * 3809 * Remove this process from all hash tables. If this process 3810 * owned any PMCs, turn off those PMCs and deallocate them, 3811 * removing any associations with target processes. 3812 * 3813 * This function will be called by the last 'thread' of a 3814 * process. 3815 * 3816 * XXX This eventhandler gets called early in the exit process. 3817 * Consider using a 'hook' invocation from thread_exit() or equivalent 3818 * spot. Another negative is that kse_exit doesn't seem to call 3819 * exit1() [??]. 3820 * 3821 */ 3822 3823 static void 3824 pmc_process_exit(void *arg __unused, struct proc *p) 3825 { 3826 int is_using_hwpmcs; 3827 int cpu; 3828 unsigned int ri; 3829 struct pmc *pm; 3830 struct pmc_process *pp; 3831 struct pmc_owner *po; 3832 pmc_value_t newvalue, tmp; 3833 3834 PROC_LOCK(p); 3835 is_using_hwpmcs = p->p_flag & P_HWPMC; 3836 PROC_UNLOCK(p); 3837 3838 /* 3839 * Log a sysexit event to all SS PMC owners. 3840 */ 3841 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 3842 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 3843 pmclog_process_sysexit(po, p->p_pid); 3844 3845 if (!is_using_hwpmcs) 3846 return; 3847 3848 PMC_GET_SX_XLOCK(); 3849 PMCDBG(PRC,EXT,1,"process-exit proc=%p (%d, %s)", p, p->p_pid, 3850 p->p_comm); 3851 3852 /* 3853 * Since this code is invoked by the last thread in an exiting 3854 * process, we would have context switched IN at some prior 3855 * point. However, with PREEMPTION, kernel mode context 3856 * switches may happen any time, so we want to disable a 3857 * context switch OUT till we get any PMCs targetting this 3858 * process off the hardware. 3859 * 3860 * We also need to atomically remove this process' 3861 * entry from our target process hash table, using 3862 * PMC_FLAG_REMOVE. 3863 */ 3864 PMCDBG(PRC,EXT,1, "process-exit proc=%p (%d, %s)", p, p->p_pid, 3865 p->p_comm); 3866 3867 critical_enter(); /* no preemption */ 3868 3869 cpu = curthread->td_oncpu; 3870 3871 if ((pp = pmc_find_process_descriptor(p, 3872 PMC_FLAG_REMOVE)) != NULL) { 3873 3874 PMCDBG(PRC,EXT,2, 3875 "process-exit proc=%p pmc-process=%p", p, pp); 3876 3877 /* 3878 * The exiting process could the target of 3879 * some PMCs which will be running on 3880 * currently executing CPU. 3881 * 3882 * We need to turn these PMCs off like we 3883 * would do at context switch OUT time. 3884 */ 3885 for (ri = 0; ri < md->pmd_npmc; ri++) { 3886 3887 /* 3888 * Pick up the pmc pointer from hardware 3889 * state similar to the CSW_OUT code. 3890 */ 3891 pm = NULL; 3892 (void) (*md->pmd_get_config)(cpu, ri, &pm); 3893 3894 PMCDBG(PRC,EXT,2, "ri=%d pm=%p", ri, pm); 3895 3896 if (pm == NULL || 3897 !PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 3898 continue; 3899 3900 PMCDBG(PRC,EXT,2, "ppmcs[%d]=%p pm=%p " 3901 "state=%d", ri, pp->pp_pmcs[ri].pp_pmc, 3902 pm, pm->pm_state); 3903 3904 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 3905 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 3906 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 3907 3908 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 3909 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", 3910 __LINE__, pm, ri, pp->pp_pmcs[ri].pp_pmc)); 3911 3912 (void) md->pmd_stop_pmc(cpu, ri); 3913 3914 KASSERT(pm->pm_runcount > 0, 3915 ("[pmc,%d] bad runcount ri %d rc %d", 3916 __LINE__, ri, pm->pm_runcount)); 3917 3918 /* Stop hardware only if it is actually running */ 3919 if (pm->pm_state == PMC_STATE_RUNNING && 3920 pm->pm_stalled == 0) { 3921 md->pmd_read_pmc(cpu, ri, &newvalue); 3922 tmp = newvalue - 3923 PMC_PCPU_SAVED(cpu,ri); 3924 3925 mtx_pool_lock_spin(pmc_mtxpool, pm); 3926 pm->pm_gv.pm_savedvalue += tmp; 3927 pp->pp_pmcs[ri].pp_pmcval += tmp; 3928 mtx_pool_unlock_spin(pmc_mtxpool, pm); 3929 } 3930 3931 atomic_subtract_rel_32(&pm->pm_runcount,1); 3932 3933 KASSERT((int) pm->pm_runcount >= 0, 3934 ("[pmc,%d] runcount is %d", __LINE__, ri)); 3935 3936 (void) md->pmd_config_pmc(cpu, ri, NULL); 3937 } 3938 3939 /* 3940 * Inform the MD layer of this pseudo "context switch 3941 * out" 3942 */ 3943 (void) md->pmd_switch_out(pmc_pcpu[cpu], pp); 3944 3945 critical_exit(); /* ok to be pre-empted now */ 3946 3947 /* 3948 * Unlink this process from the PMCs that are 3949 * targetting it. This will send a signal to 3950 * all PMC owner's whose PMCs are orphaned. 3951 * 3952 * Log PMC value at exit time if requested. 3953 */ 3954 for (ri = 0; ri < md->pmd_npmc; ri++) 3955 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 3956 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 3957 PMC_IS_COUNTING_MODE(PMC_TO_MODE(pm))) 3958 pmclog_process_procexit(pm, pp); 3959 pmc_unlink_target_process(pm, pp); 3960 } 3961 FREE(pp, M_PMC); 3962 3963 } else 3964 critical_exit(); /* pp == NULL */ 3965 3966 3967 /* 3968 * If the process owned PMCs, free them up and free up 3969 * memory. 3970 */ 3971 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 3972 pmc_remove_owner(po); 3973 pmc_destroy_owner_descriptor(po); 3974 } 3975 3976 sx_xunlock(&pmc_sx); 3977 } 3978 3979 /* 3980 * Handle a process fork. 3981 * 3982 * If the parent process 'p1' is under HWPMC monitoring, then copy 3983 * over any attached PMCs that have 'do_descendants' semantics. 3984 */ 3985 3986 static void 3987 pmc_process_fork(void *arg __unused, struct proc *p1, struct proc *newproc, 3988 int flags) 3989 { 3990 int is_using_hwpmcs; 3991 unsigned int ri; 3992 uint32_t do_descendants; 3993 struct pmc *pm; 3994 struct pmc_owner *po; 3995 struct pmc_process *ppnew, *ppold; 3996 3997 (void) flags; /* unused parameter */ 3998 3999 PROC_LOCK(p1); 4000 is_using_hwpmcs = p1->p_flag & P_HWPMC; 4001 PROC_UNLOCK(p1); 4002 4003 /* 4004 * If there are system-wide sampling PMCs active, we need to 4005 * log all fork events to their owner's logs. 4006 */ 4007 4008 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4009 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4010 pmclog_process_procfork(po, p1->p_pid, newproc->p_pid); 4011 4012 if (!is_using_hwpmcs) 4013 return; 4014 4015 PMC_GET_SX_XLOCK(); 4016 PMCDBG(PMC,FRK,1, "process-fork proc=%p (%d, %s) -> %p", p1, 4017 p1->p_pid, p1->p_comm, newproc); 4018 4019 /* 4020 * If the parent process (curthread->td_proc) is a 4021 * target of any PMCs, look for PMCs that are to be 4022 * inherited, and link these into the new process 4023 * descriptor. 4024 */ 4025 if ((ppold = pmc_find_process_descriptor(curthread->td_proc, 4026 PMC_FLAG_NONE)) == NULL) 4027 goto done; /* nothing to do */ 4028 4029 do_descendants = 0; 4030 for (ri = 0; ri < md->pmd_npmc; ri++) 4031 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL) 4032 do_descendants |= pm->pm_flags & PMC_F_DESCENDANTS; 4033 if (do_descendants == 0) /* nothing to do */ 4034 goto done; 4035 4036 /* allocate a descriptor for the new process */ 4037 if ((ppnew = pmc_find_process_descriptor(newproc, 4038 PMC_FLAG_ALLOCATE)) == NULL) 4039 goto done; 4040 4041 /* 4042 * Run through all PMCs that were targeting the old process 4043 * and which specified F_DESCENDANTS and attach them to the 4044 * new process. 4045 * 4046 * Log the fork event to all owners of PMCs attached to this 4047 * process, if not already logged. 4048 */ 4049 for (ri = 0; ri < md->pmd_npmc; ri++) 4050 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL && 4051 (pm->pm_flags & PMC_F_DESCENDANTS)) { 4052 pmc_link_target_process(pm, ppnew); 4053 po = pm->pm_owner; 4054 if (po->po_sscount == 0 && 4055 po->po_flags & PMC_PO_OWNS_LOGFILE) 4056 pmclog_process_procfork(po, p1->p_pid, 4057 newproc->p_pid); 4058 } 4059 4060 /* 4061 * Now mark the new process as being tracked by this driver. 4062 */ 4063 PROC_LOCK(newproc); 4064 newproc->p_flag |= P_HWPMC; 4065 PROC_UNLOCK(newproc); 4066 4067 done: 4068 sx_xunlock(&pmc_sx); 4069 } 4070 4071 4072 /* 4073 * initialization 4074 */ 4075 4076 static const char *pmc_name_of_pmcclass[] = { 4077 #undef __PMC_CLASS 4078 #define __PMC_CLASS(N) #N , 4079 __PMC_CLASSES() 4080 }; 4081 4082 static int 4083 pmc_initialize(void) 4084 { 4085 int cpu, error, n; 4086 struct pmc_binding pb; 4087 struct pmc_samplebuffer *sb; 4088 4089 md = NULL; 4090 error = 0; 4091 4092 #ifdef DEBUG 4093 /* parse debug flags first */ 4094 if (TUNABLE_STR_FETCH(PMC_SYSCTL_NAME_PREFIX "debugflags", 4095 pmc_debugstr, sizeof(pmc_debugstr))) 4096 pmc_debugflags_parse(pmc_debugstr, 4097 pmc_debugstr+strlen(pmc_debugstr)); 4098 #endif 4099 4100 PMCDBG(MOD,INI,0, "PMC Initialize (version %x)", PMC_VERSION); 4101 4102 /* check kernel version */ 4103 if (pmc_kernel_version != PMC_VERSION) { 4104 if (pmc_kernel_version == 0) 4105 printf("hwpmc: this kernel has not been compiled with " 4106 "'options HWPMC_HOOKS'.\n"); 4107 else 4108 printf("hwpmc: kernel version (0x%x) does not match " 4109 "module version (0x%x).\n", pmc_kernel_version, 4110 PMC_VERSION); 4111 return EPROGMISMATCH; 4112 } 4113 4114 /* 4115 * check sysctl parameters 4116 */ 4117 4118 if (pmc_hashsize <= 0) { 4119 (void) printf("hwpmc: tunable hashsize=%d must be greater " 4120 "than zero.\n", pmc_hashsize); 4121 pmc_hashsize = PMC_HASH_SIZE; 4122 } 4123 4124 if (pmc_nsamples <= 0 || pmc_nsamples > 65535) { 4125 (void) printf("hwpmc: tunable nsamples=%d out of range.\n", 4126 pmc_nsamples); 4127 pmc_nsamples = PMC_NSAMPLES; 4128 } 4129 4130 md = pmc_md_initialize(); 4131 4132 if (md == NULL || md->pmd_init == NULL) 4133 return ENOSYS; 4134 4135 /* allocate space for the per-cpu array */ 4136 MALLOC(pmc_pcpu, struct pmc_cpu **, mp_ncpus * sizeof(struct pmc_cpu *), 4137 M_PMC, M_WAITOK|M_ZERO); 4138 4139 /* per-cpu 'saved values' for managing process-mode PMCs */ 4140 MALLOC(pmc_pcpu_saved, pmc_value_t *, 4141 sizeof(pmc_value_t) * mp_ncpus * md->pmd_npmc, M_PMC, M_WAITOK); 4142 4143 /* perform cpu dependent initialization */ 4144 pmc_save_cpu_binding(&pb); 4145 for (cpu = 0; cpu < mp_ncpus; cpu++) { 4146 if (pmc_cpu_is_disabled(cpu)) 4147 continue; 4148 pmc_select_cpu(cpu); 4149 if ((error = md->pmd_init(cpu)) != 0) 4150 break; 4151 } 4152 pmc_restore_cpu_binding(&pb); 4153 4154 if (error != 0) 4155 return error; 4156 4157 /* allocate space for the sample array */ 4158 for (cpu = 0; cpu < mp_ncpus; cpu++) { 4159 if (pmc_cpu_is_disabled(cpu)) 4160 continue; 4161 MALLOC(sb, struct pmc_samplebuffer *, 4162 sizeof(struct pmc_samplebuffer) + 4163 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 4164 M_WAITOK|M_ZERO); 4165 4166 sb->ps_read = sb->ps_write = sb->ps_samples; 4167 sb->ps_fence = sb->ps_samples + pmc_nsamples; 4168 KASSERT(pmc_pcpu[cpu] != NULL, 4169 ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu)); 4170 4171 pmc_pcpu[cpu]->pc_sb = sb; 4172 } 4173 4174 /* allocate space for the row disposition array */ 4175 pmc_pmcdisp = malloc(sizeof(enum pmc_mode) * md->pmd_npmc, 4176 M_PMC, M_WAITOK|M_ZERO); 4177 4178 KASSERT(pmc_pmcdisp != NULL, 4179 ("[pmc,%d] pmcdisp allocation returned NULL", __LINE__)); 4180 4181 /* mark all PMCs as available */ 4182 for (n = 0; n < (int) md->pmd_npmc; n++) 4183 PMC_MARK_ROW_FREE(n); 4184 4185 /* allocate thread hash tables */ 4186 pmc_ownerhash = hashinit(pmc_hashsize, M_PMC, 4187 &pmc_ownerhashmask); 4188 4189 pmc_processhash = hashinit(pmc_hashsize, M_PMC, 4190 &pmc_processhashmask); 4191 mtx_init(&pmc_processhash_mtx, "pmc-process-hash", "pmc", MTX_SPIN); 4192 4193 LIST_INIT(&pmc_ss_owners); 4194 pmc_ss_count = 0; 4195 4196 /* allocate a pool of spin mutexes */ 4197 pmc_mtxpool = mtx_pool_create("pmc", pmc_mtxpool_size, MTX_SPIN); 4198 4199 PMCDBG(MOD,INI,1, "pmc_ownerhash=%p, mask=0x%lx " 4200 "targethash=%p mask=0x%lx", pmc_ownerhash, pmc_ownerhashmask, 4201 pmc_processhash, pmc_processhashmask); 4202 4203 /* register process {exit,fork,exec} handlers */ 4204 pmc_exit_tag = EVENTHANDLER_REGISTER(process_exit, 4205 pmc_process_exit, NULL, EVENTHANDLER_PRI_ANY); 4206 pmc_fork_tag = EVENTHANDLER_REGISTER(process_fork, 4207 pmc_process_fork, NULL, EVENTHANDLER_PRI_ANY); 4208 4209 /* initialize logging */ 4210 pmclog_initialize(); 4211 4212 /* set hook functions */ 4213 pmc_intr = md->pmd_intr; 4214 pmc_hook = pmc_hook_handler; 4215 4216 if (error == 0) { 4217 printf(PMC_MODULE_NAME ":"); 4218 for (n = 0; n < (int) md->pmd_nclass; n++) { 4219 printf(" %s/%d/0x%b", 4220 pmc_name_of_pmcclass[md->pmd_classes[n].pm_class], 4221 md->pmd_nclasspmcs[n], 4222 md->pmd_classes[n].pm_caps, 4223 "\20" 4224 "\1INT\2USR\3SYS\4EDG\5THR" 4225 "\6REA\7WRI\10INV\11QUA\12PRC" 4226 "\13TAG\14CSC"); 4227 } 4228 printf("\n"); 4229 } 4230 4231 return error; 4232 } 4233 4234 /* prepare to be unloaded */ 4235 static void 4236 pmc_cleanup(void) 4237 { 4238 int cpu; 4239 struct pmc_ownerhash *ph; 4240 struct pmc_owner *po, *tmp; 4241 struct pmc_binding pb; 4242 #ifdef DEBUG 4243 struct pmc_processhash *prh; 4244 #endif 4245 4246 PMCDBG(MOD,INI,0, "%s", "cleanup"); 4247 4248 /* switch off sampling */ 4249 atomic_store_rel_int(&pmc_cpumask, 0); 4250 pmc_intr = NULL; 4251 4252 sx_xlock(&pmc_sx); 4253 if (pmc_hook == NULL) { /* being unloaded already */ 4254 sx_xunlock(&pmc_sx); 4255 return; 4256 } 4257 4258 pmc_hook = NULL; /* prevent new threads from entering module */ 4259 4260 /* deregister event handlers */ 4261 EVENTHANDLER_DEREGISTER(process_fork, pmc_fork_tag); 4262 EVENTHANDLER_DEREGISTER(process_exit, pmc_exit_tag); 4263 4264 /* send SIGBUS to all owner threads, free up allocations */ 4265 if (pmc_ownerhash) 4266 for (ph = pmc_ownerhash; 4267 ph <= &pmc_ownerhash[pmc_ownerhashmask]; 4268 ph++) { 4269 LIST_FOREACH_SAFE(po, ph, po_next, tmp) { 4270 pmc_remove_owner(po); 4271 4272 /* send SIGBUS to owner processes */ 4273 PMCDBG(MOD,INI,2, "cleanup signal proc=%p " 4274 "(%d, %s)", po->po_owner, 4275 po->po_owner->p_pid, 4276 po->po_owner->p_comm); 4277 4278 PROC_LOCK(po->po_owner); 4279 psignal(po->po_owner, SIGBUS); 4280 PROC_UNLOCK(po->po_owner); 4281 4282 pmc_destroy_owner_descriptor(po); 4283 } 4284 } 4285 4286 /* reclaim allocated data structures */ 4287 if (pmc_mtxpool) 4288 mtx_pool_destroy(&pmc_mtxpool); 4289 4290 mtx_destroy(&pmc_processhash_mtx); 4291 if (pmc_processhash) { 4292 #ifdef DEBUG 4293 struct pmc_process *pp; 4294 4295 PMCDBG(MOD,INI,3, "%s", "destroy process hash"); 4296 for (prh = pmc_processhash; 4297 prh <= &pmc_processhash[pmc_processhashmask]; 4298 prh++) 4299 LIST_FOREACH(pp, prh, pp_next) 4300 PMCDBG(MOD,INI,3, "pid=%d", pp->pp_proc->p_pid); 4301 #endif 4302 4303 hashdestroy(pmc_processhash, M_PMC, pmc_processhashmask); 4304 pmc_processhash = NULL; 4305 } 4306 4307 if (pmc_ownerhash) { 4308 PMCDBG(MOD,INI,3, "%s", "destroy owner hash"); 4309 hashdestroy(pmc_ownerhash, M_PMC, pmc_ownerhashmask); 4310 pmc_ownerhash = NULL; 4311 } 4312 4313 KASSERT(LIST_EMPTY(&pmc_ss_owners), 4314 ("[pmc,%d] Global SS owner list not empty", __LINE__)); 4315 KASSERT(pmc_ss_count == 0, 4316 ("[pmc,%d] Global SS count not empty", __LINE__)); 4317 4318 /* free the per-cpu sample buffers */ 4319 for (cpu = 0; cpu < mp_ncpus; cpu++) { 4320 if (pmc_cpu_is_disabled(cpu)) 4321 continue; 4322 KASSERT(pmc_pcpu[cpu]->pc_sb != NULL, 4323 ("[pmc,%d] Null cpu sample buffer cpu=%d", __LINE__, 4324 cpu)); 4325 FREE(pmc_pcpu[cpu]->pc_sb, M_PMC); 4326 pmc_pcpu[cpu]->pc_sb = NULL; 4327 } 4328 4329 /* do processor dependent cleanup */ 4330 PMCDBG(MOD,INI,3, "%s", "md cleanup"); 4331 if (md) { 4332 pmc_save_cpu_binding(&pb); 4333 for (cpu = 0; cpu < mp_ncpus; cpu++) { 4334 PMCDBG(MOD,INI,1,"pmc-cleanup cpu=%d pcs=%p", 4335 cpu, pmc_pcpu[cpu]); 4336 if (pmc_cpu_is_disabled(cpu)) 4337 continue; 4338 pmc_select_cpu(cpu); 4339 if (pmc_pcpu[cpu]) 4340 (void) md->pmd_cleanup(cpu); 4341 } 4342 FREE(md, M_PMC); 4343 md = NULL; 4344 pmc_restore_cpu_binding(&pb); 4345 } 4346 4347 /* deallocate per-cpu structures */ 4348 FREE(pmc_pcpu, M_PMC); 4349 pmc_pcpu = NULL; 4350 4351 FREE(pmc_pcpu_saved, M_PMC); 4352 pmc_pcpu_saved = NULL; 4353 4354 if (pmc_pmcdisp) { 4355 FREE(pmc_pmcdisp, M_PMC); 4356 pmc_pmcdisp = NULL; 4357 } 4358 4359 pmclog_shutdown(); 4360 4361 sx_xunlock(&pmc_sx); /* we are done */ 4362 } 4363 4364 /* 4365 * The function called at load/unload. 4366 */ 4367 4368 static int 4369 load (struct module *module __unused, int cmd, void *arg __unused) 4370 { 4371 int error; 4372 4373 error = 0; 4374 4375 switch (cmd) { 4376 case MOD_LOAD : 4377 /* initialize the subsystem */ 4378 error = pmc_initialize(); 4379 if (error != 0) 4380 break; 4381 PMCDBG(MOD,INI,1, "syscall=%d ncpus=%d", 4382 pmc_syscall_num, mp_ncpus); 4383 break; 4384 4385 4386 case MOD_UNLOAD : 4387 case MOD_SHUTDOWN: 4388 pmc_cleanup(); 4389 PMCDBG(MOD,INI,1, "%s", "unloaded"); 4390 break; 4391 4392 default : 4393 error = EINVAL; /* XXX should panic(9) */ 4394 break; 4395 } 4396 4397 return error; 4398 } 4399 4400 /* memory pool */ 4401 MALLOC_DEFINE(M_PMC, "pmc", "Memory space for the PMC module"); 4402