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/priv.h> 45 #include <sys/proc.h> 46 #include <sys/queue.h> 47 #include <sys/resourcevar.h> 48 #include <sys/sched.h> 49 #include <sys/signalvar.h> 50 #include <sys/smp.h> 51 #include <sys/sx.h> 52 #include <sys/sysctl.h> 53 #include <sys/sysent.h> 54 #include <sys/systm.h> 55 #include <sys/vnode.h> 56 57 #include <sys/linker.h> /* needs to be after <sys/malloc.h> */ 58 59 #include <machine/atomic.h> 60 #include <machine/md_var.h> 61 62 /* 63 * Types 64 */ 65 66 enum pmc_flags { 67 PMC_FLAG_NONE = 0x00, /* do nothing */ 68 PMC_FLAG_REMOVE = 0x01, /* atomically remove entry from hash */ 69 PMC_FLAG_ALLOCATE = 0x02, /* add entry to hash if not found */ 70 }; 71 72 /* 73 * The offset in sysent where the syscall is allocated. 74 */ 75 76 static int pmc_syscall_num = NO_SYSCALL; 77 struct pmc_cpu **pmc_pcpu; /* per-cpu state */ 78 pmc_value_t *pmc_pcpu_saved; /* saved PMC values: CSW handling */ 79 80 #define PMC_PCPU_SAVED(C,R) pmc_pcpu_saved[(R) + md->pmd_npmc*(C)] 81 82 struct mtx_pool *pmc_mtxpool; 83 static int *pmc_pmcdisp; /* PMC row dispositions */ 84 85 #define PMC_ROW_DISP_IS_FREE(R) (pmc_pmcdisp[(R)] == 0) 86 #define PMC_ROW_DISP_IS_THREAD(R) (pmc_pmcdisp[(R)] > 0) 87 #define PMC_ROW_DISP_IS_STANDALONE(R) (pmc_pmcdisp[(R)] < 0) 88 89 #define PMC_MARK_ROW_FREE(R) do { \ 90 pmc_pmcdisp[(R)] = 0; \ 91 } while (0) 92 93 #define PMC_MARK_ROW_STANDALONE(R) do { \ 94 KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \ 95 __LINE__)); \ 96 atomic_add_int(&pmc_pmcdisp[(R)], -1); \ 97 KASSERT(pmc_pmcdisp[(R)] >= (-mp_ncpus), ("[pmc,%d] row " \ 98 "disposition error", __LINE__)); \ 99 } while (0) 100 101 #define PMC_UNMARK_ROW_STANDALONE(R) do { \ 102 atomic_add_int(&pmc_pmcdisp[(R)], 1); \ 103 KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \ 104 __LINE__)); \ 105 } while (0) 106 107 #define PMC_MARK_ROW_THREAD(R) do { \ 108 KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \ 109 __LINE__)); \ 110 atomic_add_int(&pmc_pmcdisp[(R)], 1); \ 111 } while (0) 112 113 #define PMC_UNMARK_ROW_THREAD(R) do { \ 114 atomic_add_int(&pmc_pmcdisp[(R)], -1); \ 115 KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \ 116 __LINE__)); \ 117 } while (0) 118 119 120 /* various event handlers */ 121 static eventhandler_tag pmc_exit_tag, pmc_fork_tag; 122 123 /* Module statistics */ 124 struct pmc_op_getdriverstats pmc_stats; 125 126 /* Machine/processor dependent operations */ 127 struct pmc_mdep *md; 128 129 /* 130 * Hash tables mapping owner processes and target threads to PMCs. 131 */ 132 133 struct mtx pmc_processhash_mtx; /* spin mutex */ 134 static u_long pmc_processhashmask; 135 static LIST_HEAD(pmc_processhash, pmc_process) *pmc_processhash; 136 137 /* 138 * Hash table of PMC owner descriptors. This table is protected by 139 * the shared PMC "sx" lock. 140 */ 141 142 static u_long pmc_ownerhashmask; 143 static LIST_HEAD(pmc_ownerhash, pmc_owner) *pmc_ownerhash; 144 145 /* 146 * List of PMC owners with system-wide sampling PMCs. 147 */ 148 149 static LIST_HEAD(, pmc_owner) pmc_ss_owners; 150 151 152 /* 153 * Prototypes 154 */ 155 156 #ifdef DEBUG 157 static int pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS); 158 static int pmc_debugflags_parse(char *newstr, char *fence); 159 #endif 160 161 static int load(struct module *module, int cmd, void *arg); 162 static int pmc_attach_process(struct proc *p, struct pmc *pm); 163 static struct pmc *pmc_allocate_pmc_descriptor(void); 164 static struct pmc_owner *pmc_allocate_owner_descriptor(struct proc *p); 165 static int pmc_attach_one_process(struct proc *p, struct pmc *pm); 166 static int pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, 167 int cpu); 168 static int pmc_can_attach(struct pmc *pm, struct proc *p); 169 static void pmc_cleanup(void); 170 static int pmc_detach_process(struct proc *p, struct pmc *pm); 171 static int pmc_detach_one_process(struct proc *p, struct pmc *pm, 172 int flags); 173 static void pmc_destroy_owner_descriptor(struct pmc_owner *po); 174 static struct pmc_owner *pmc_find_owner_descriptor(struct proc *p); 175 static int pmc_find_pmc(pmc_id_t pmcid, struct pmc **pm); 176 static struct pmc *pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, 177 pmc_id_t pmc); 178 static struct pmc_process *pmc_find_process_descriptor(struct proc *p, 179 uint32_t mode); 180 static void pmc_force_context_switch(void); 181 static void pmc_link_target_process(struct pmc *pm, 182 struct pmc_process *pp); 183 static void pmc_maybe_remove_owner(struct pmc_owner *po); 184 static void pmc_process_csw_in(struct thread *td); 185 static void pmc_process_csw_out(struct thread *td); 186 static void pmc_process_exit(void *arg, struct proc *p); 187 static void pmc_process_fork(void *arg, struct proc *p1, 188 struct proc *p2, int n); 189 static void pmc_process_samples(int cpu); 190 static void pmc_release_pmc_descriptor(struct pmc *pmc); 191 static void pmc_remove_owner(struct pmc_owner *po); 192 static void pmc_remove_process_descriptor(struct pmc_process *pp); 193 static void pmc_restore_cpu_binding(struct pmc_binding *pb); 194 static void pmc_save_cpu_binding(struct pmc_binding *pb); 195 static void pmc_select_cpu(int cpu); 196 static int pmc_start(struct pmc *pm); 197 static int pmc_stop(struct pmc *pm); 198 static int pmc_syscall_handler(struct thread *td, void *syscall_args); 199 static void pmc_unlink_target_process(struct pmc *pmc, 200 struct pmc_process *pp); 201 202 /* 203 * Kernel tunables and sysctl(8) interface. 204 */ 205 206 SYSCTL_NODE(_kern, OID_AUTO, hwpmc, CTLFLAG_RW, 0, "HWPMC parameters"); 207 208 #ifdef DEBUG 209 struct pmc_debugflags pmc_debugflags = PMC_DEBUG_DEFAULT_FLAGS; 210 char pmc_debugstr[PMC_DEBUG_STRSIZE]; 211 TUNABLE_STR(PMC_SYSCTL_NAME_PREFIX "debugflags", pmc_debugstr, 212 sizeof(pmc_debugstr)); 213 SYSCTL_PROC(_kern_hwpmc, OID_AUTO, debugflags, 214 CTLTYPE_STRING|CTLFLAG_RW|CTLFLAG_TUN, 215 0, 0, pmc_debugflags_sysctl_handler, "A", "debug flags"); 216 #endif 217 218 /* 219 * kern.hwpmc.hashrows -- determines the number of rows in the 220 * of the hash table used to look up threads 221 */ 222 223 static int pmc_hashsize = PMC_HASH_SIZE; 224 TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "hashsize", &pmc_hashsize); 225 SYSCTL_INT(_kern_hwpmc, OID_AUTO, hashsize, CTLFLAG_TUN|CTLFLAG_RD, 226 &pmc_hashsize, 0, "rows in hash tables"); 227 228 /* 229 * kern.hwpmc.nsamples --- number of PC samples per CPU 230 */ 231 232 static int pmc_nsamples = PMC_NSAMPLES; 233 TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "nsamples", &pmc_nsamples); 234 SYSCTL_INT(_kern_hwpmc, OID_AUTO, nsamples, CTLFLAG_TUN|CTLFLAG_RD, 235 &pmc_nsamples, 0, "number of PC samples per CPU"); 236 237 /* 238 * kern.hwpmc.mtxpoolsize -- number of mutexes in the mutex pool. 239 */ 240 241 static int pmc_mtxpool_size = PMC_MTXPOOL_SIZE; 242 TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "mtxpoolsize", &pmc_mtxpool_size); 243 SYSCTL_INT(_kern_hwpmc, OID_AUTO, mtxpoolsize, CTLFLAG_TUN|CTLFLAG_RD, 244 &pmc_mtxpool_size, 0, "size of spin mutex pool"); 245 246 247 /* 248 * security.bsd.unprivileged_syspmcs -- allow non-root processes to 249 * allocate system-wide PMCs. 250 * 251 * Allowing unprivileged processes to allocate system PMCs is convenient 252 * if system-wide measurements need to be taken concurrently with other 253 * per-process measurements. This feature is turned off by default. 254 */ 255 256 static int pmc_unprivileged_syspmcs = 0; 257 TUNABLE_INT("security.bsd.unprivileged_syspmcs", &pmc_unprivileged_syspmcs); 258 SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_syspmcs, CTLFLAG_RW, 259 &pmc_unprivileged_syspmcs, 0, 260 "allow unprivileged process to allocate system PMCs"); 261 262 /* 263 * Hash function. Discard the lower 2 bits of the pointer since 264 * these are always zero for our uses. The hash multiplier is 265 * round((2^LONG_BIT) * ((sqrt(5)-1)/2)). 266 */ 267 268 #if LONG_BIT == 64 269 #define _PMC_HM 11400714819323198486u 270 #elif LONG_BIT == 32 271 #define _PMC_HM 2654435769u 272 #else 273 #error Must know the size of 'long' to compile 274 #endif 275 276 #define PMC_HASH_PTR(P,M) ((((unsigned long) (P) >> 2) * _PMC_HM) & (M)) 277 278 /* 279 * Syscall structures 280 */ 281 282 /* The `sysent' for the new syscall */ 283 static struct sysent pmc_sysent = { 284 2, /* sy_narg */ 285 pmc_syscall_handler /* sy_call */ 286 }; 287 288 static struct syscall_module_data pmc_syscall_mod = { 289 load, 290 NULL, 291 &pmc_syscall_num, 292 &pmc_sysent, 293 { 0, NULL } 294 }; 295 296 static moduledata_t pmc_mod = { 297 PMC_MODULE_NAME, 298 syscall_module_handler, 299 &pmc_syscall_mod 300 }; 301 302 DECLARE_MODULE(pmc, pmc_mod, SI_SUB_SMP, SI_ORDER_ANY); 303 MODULE_VERSION(pmc, PMC_VERSION); 304 305 #ifdef DEBUG 306 enum pmc_dbgparse_state { 307 PMCDS_WS, /* in whitespace */ 308 PMCDS_MAJOR, /* seen a major keyword */ 309 PMCDS_MINOR 310 }; 311 312 static int 313 pmc_debugflags_parse(char *newstr, char *fence) 314 { 315 char c, *p, *q; 316 struct pmc_debugflags *tmpflags; 317 int error, found, *newbits, tmp; 318 size_t kwlen; 319 320 MALLOC(tmpflags, struct pmc_debugflags *, sizeof(*tmpflags), 321 M_PMC, M_WAITOK|M_ZERO); 322 323 p = newstr; 324 error = 0; 325 326 for (; p < fence && (c = *p); p++) { 327 328 /* skip white space */ 329 if (c == ' ' || c == '\t') 330 continue; 331 332 /* look for a keyword followed by "=" */ 333 for (q = p; p < fence && (c = *p) && c != '='; p++) 334 ; 335 if (c != '=') { 336 error = EINVAL; 337 goto done; 338 } 339 340 kwlen = p - q; 341 newbits = NULL; 342 343 /* lookup flag group name */ 344 #define DBG_SET_FLAG_MAJ(S,F) \ 345 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \ 346 newbits = &tmpflags->pdb_ ## F; 347 348 DBG_SET_FLAG_MAJ("cpu", CPU); 349 DBG_SET_FLAG_MAJ("csw", CSW); 350 DBG_SET_FLAG_MAJ("logging", LOG); 351 DBG_SET_FLAG_MAJ("module", MOD); 352 DBG_SET_FLAG_MAJ("md", MDP); 353 DBG_SET_FLAG_MAJ("owner", OWN); 354 DBG_SET_FLAG_MAJ("pmc", PMC); 355 DBG_SET_FLAG_MAJ("process", PRC); 356 DBG_SET_FLAG_MAJ("sampling", SAM); 357 358 if (newbits == NULL) { 359 error = EINVAL; 360 goto done; 361 } 362 363 p++; /* skip the '=' */ 364 365 /* Now parse the individual flags */ 366 tmp = 0; 367 newflag: 368 for (q = p; p < fence && (c = *p); p++) 369 if (c == ' ' || c == '\t' || c == ',') 370 break; 371 372 /* p == fence or c == ws or c == "," or c == 0 */ 373 374 if ((kwlen = p - q) == 0) { 375 *newbits = tmp; 376 continue; 377 } 378 379 found = 0; 380 #define DBG_SET_FLAG_MIN(S,F) \ 381 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \ 382 tmp |= found = (1 << PMC_DEBUG_MIN_ ## F) 383 384 /* a '*' denotes all possible flags in the group */ 385 if (kwlen == 1 && *q == '*') 386 tmp = found = ~0; 387 /* look for individual flag names */ 388 DBG_SET_FLAG_MIN("allocaterow", ALR); 389 DBG_SET_FLAG_MIN("allocate", ALL); 390 DBG_SET_FLAG_MIN("attach", ATT); 391 DBG_SET_FLAG_MIN("bind", BND); 392 DBG_SET_FLAG_MIN("config", CFG); 393 DBG_SET_FLAG_MIN("exec", EXC); 394 DBG_SET_FLAG_MIN("exit", EXT); 395 DBG_SET_FLAG_MIN("find", FND); 396 DBG_SET_FLAG_MIN("flush", FLS); 397 DBG_SET_FLAG_MIN("fork", FRK); 398 DBG_SET_FLAG_MIN("getbuf", GTB); 399 DBG_SET_FLAG_MIN("hook", PMH); 400 DBG_SET_FLAG_MIN("init", INI); 401 DBG_SET_FLAG_MIN("intr", INT); 402 DBG_SET_FLAG_MIN("linktarget", TLK); 403 DBG_SET_FLAG_MIN("mayberemove", OMR); 404 DBG_SET_FLAG_MIN("ops", OPS); 405 DBG_SET_FLAG_MIN("read", REA); 406 DBG_SET_FLAG_MIN("register", REG); 407 DBG_SET_FLAG_MIN("release", REL); 408 DBG_SET_FLAG_MIN("remove", ORM); 409 DBG_SET_FLAG_MIN("sample", SAM); 410 DBG_SET_FLAG_MIN("scheduleio", SIO); 411 DBG_SET_FLAG_MIN("select", SEL); 412 DBG_SET_FLAG_MIN("signal", SIG); 413 DBG_SET_FLAG_MIN("swi", SWI); 414 DBG_SET_FLAG_MIN("swo", SWO); 415 DBG_SET_FLAG_MIN("start", STA); 416 DBG_SET_FLAG_MIN("stop", STO); 417 DBG_SET_FLAG_MIN("syscall", PMS); 418 DBG_SET_FLAG_MIN("unlinktarget", TUL); 419 DBG_SET_FLAG_MIN("write", WRI); 420 if (found == 0) { 421 /* unrecognized flag name */ 422 error = EINVAL; 423 goto done; 424 } 425 426 if (c == 0 || c == ' ' || c == '\t') { /* end of flag group */ 427 *newbits = tmp; 428 continue; 429 } 430 431 p++; 432 goto newflag; 433 } 434 435 /* save the new flag set */ 436 bcopy(tmpflags, &pmc_debugflags, sizeof(pmc_debugflags)); 437 438 done: 439 FREE(tmpflags, M_PMC); 440 return error; 441 } 442 443 static int 444 pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS) 445 { 446 char *fence, *newstr; 447 int error; 448 unsigned int n; 449 450 (void) arg1; (void) arg2; /* unused parameters */ 451 452 n = sizeof(pmc_debugstr); 453 MALLOC(newstr, char *, n, M_PMC, M_ZERO|M_WAITOK); 454 (void) strlcpy(newstr, pmc_debugstr, n); 455 456 error = sysctl_handle_string(oidp, newstr, n, req); 457 458 /* if there is a new string, parse and copy it */ 459 if (error == 0 && req->newptr != NULL) { 460 fence = newstr + (n < req->newlen ? n : req->newlen + 1); 461 if ((error = pmc_debugflags_parse(newstr, fence)) == 0) 462 (void) strlcpy(pmc_debugstr, newstr, 463 sizeof(pmc_debugstr)); 464 } 465 466 FREE(newstr, M_PMC); 467 468 return error; 469 } 470 #endif 471 472 /* 473 * Concurrency Control 474 * 475 * The driver manages the following data structures: 476 * 477 * - target process descriptors, one per target process 478 * - owner process descriptors (and attached lists), one per owner process 479 * - lookup hash tables for owner and target processes 480 * - PMC descriptors (and attached lists) 481 * - per-cpu hardware state 482 * - the 'hook' variable through which the kernel calls into 483 * this module 484 * - the machine hardware state (managed by the MD layer) 485 * 486 * These data structures are accessed from: 487 * 488 * - thread context-switch code 489 * - interrupt handlers (possibly on multiple cpus) 490 * - kernel threads on multiple cpus running on behalf of user 491 * processes doing system calls 492 * - this driver's private kernel threads 493 * 494 * = Locks and Locking strategy = 495 * 496 * The driver uses four locking strategies for its operation: 497 * 498 * - There is a 'global' SX lock "pmc_sx" that is used to protect 499 * the its 'meta-data'. 500 * 501 * Calls into the module (via syscall() or by the kernel) start with 502 * this lock being held in exclusive mode. Depending on the requested 503 * operation, the lock may be downgraded to 'shared' mode to allow 504 * more concurrent readers into the module. 505 * 506 * This SX lock is held in exclusive mode for any operations that 507 * modify the linkages between the driver's internal data structures. 508 * 509 * The 'pmc_hook' function pointer is also protected by this lock. 510 * It is only examined with the sx lock held in exclusive mode. The 511 * kernel module is allowed to be unloaded only with the sx lock 512 * held in exclusive mode. In normal syscall handling, after 513 * acquiring the pmc_sx lock we first check that 'pmc_hook' is 514 * non-null before proceeding. This prevents races between the 515 * thread unloading the module and other threads seeking to use the 516 * module. 517 * 518 * - Lookups of target process structures and owner process structures 519 * cannot use the global "pmc_sx" SX lock because these lookups need 520 * to happen during context switches and in other critical sections 521 * where sleeping is not allowed. We protect these lookup tables 522 * with their own private spin-mutexes, "pmc_processhash_mtx" and 523 * "pmc_ownerhash_mtx". These are 'leaf' mutexes, in that no other 524 * lock is acquired with these locks held. 525 * 526 * - Interrupt handlers work in a lock free manner. At interrupt 527 * time, handlers look at the PMC pointer (phw->phw_pmc) configured 528 * when the PMC was started. If this pointer is NULL, the interrupt 529 * is ignored after updating driver statistics. We ensure that this 530 * pointer is set (using an atomic operation if necessary) before the 531 * PMC hardware is started. Conversely, this pointer is unset atomically 532 * only after the PMC hardware is stopped. 533 * 534 * We ensure that everything needed for the operation of an 535 * interrupt handler is available without it needing to acquire any 536 * locks. We also ensure that a PMC's software state is destroyed only 537 * after the PMC is taken off hardware (on all CPUs). 538 * 539 * - Context-switch handling with process-private PMCs needs more 540 * care. 541 * 542 * A given process may be the target of multiple PMCs. For example, 543 * PMCATTACH and PMCDETACH may be requested by a process on one CPU 544 * while the target process is running on another. A PMC could also 545 * be getting released because its owner is exiting. We tackle 546 * these situations in the following manner: 547 * 548 * - each target process structure 'pmc_process' has an array 549 * of 'struct pmc *' pointers, one for each hardware PMC. 550 * 551 * - At context switch IN time, each "target" PMC in RUNNING state 552 * gets started on hardware and a pointer to each PMC is copied into 553 * the per-cpu phw array. The 'runcount' for the PMC is 554 * incremented. 555 * 556 * - At context switch OUT time, all process-virtual PMCs are stopped 557 * on hardware. The saved value is added to the PMCs value field 558 * only if the PMC is in a non-deleted state (the PMCs state could 559 * have changed during the current time slice). 560 * 561 * Note that since in-between a switch IN on a processor and a switch 562 * OUT, the PMC could have been released on another CPU. Therefore 563 * context switch OUT always looks at the hardware state to turn 564 * OFF PMCs and will update a PMC's saved value only if reachable 565 * from the target process record. 566 * 567 * - OP PMCRELEASE could be called on a PMC at any time (the PMC could 568 * be attached to many processes at the time of the call and could 569 * be active on multiple CPUs). 570 * 571 * We prevent further scheduling of the PMC by marking it as in 572 * state 'DELETED'. If the runcount of the PMC is non-zero then 573 * this PMC is currently running on a CPU somewhere. The thread 574 * doing the PMCRELEASE operation waits by repeatedly doing a 575 * pause() till the runcount comes to zero. 576 * 577 */ 578 579 /* 580 * save the cpu binding of the current kthread 581 */ 582 583 static void 584 pmc_save_cpu_binding(struct pmc_binding *pb) 585 { 586 PMCDBG(CPU,BND,2, "%s", "save-cpu"); 587 mtx_lock_spin(&sched_lock); 588 pb->pb_bound = sched_is_bound(curthread); 589 pb->pb_cpu = curthread->td_oncpu; 590 mtx_unlock_spin(&sched_lock); 591 PMCDBG(CPU,BND,2, "save-cpu cpu=%d", pb->pb_cpu); 592 } 593 594 /* 595 * restore the cpu binding of the current thread 596 */ 597 598 static void 599 pmc_restore_cpu_binding(struct pmc_binding *pb) 600 { 601 PMCDBG(CPU,BND,2, "restore-cpu curcpu=%d restore=%d", 602 curthread->td_oncpu, pb->pb_cpu); 603 mtx_lock_spin(&sched_lock); 604 if (pb->pb_bound) 605 sched_bind(curthread, pb->pb_cpu); 606 else 607 sched_unbind(curthread); 608 mtx_unlock_spin(&sched_lock); 609 PMCDBG(CPU,BND,2, "%s", "restore-cpu done"); 610 } 611 612 /* 613 * move execution over the specified cpu and bind it there. 614 */ 615 616 static void 617 pmc_select_cpu(int cpu) 618 { 619 KASSERT(cpu >= 0 && cpu < mp_ncpus, 620 ("[pmc,%d] bad cpu number %d", __LINE__, cpu)); 621 622 /* never move to a disabled CPU */ 623 KASSERT(pmc_cpu_is_disabled(cpu) == 0, ("[pmc,%d] selecting " 624 "disabled CPU %d", __LINE__, cpu)); 625 626 PMCDBG(CPU,SEL,2, "select-cpu cpu=%d", cpu); 627 mtx_lock_spin(&sched_lock); 628 sched_bind(curthread, cpu); 629 mtx_unlock_spin(&sched_lock); 630 631 KASSERT(curthread->td_oncpu == cpu, 632 ("[pmc,%d] CPU not bound [cpu=%d, curr=%d]", __LINE__, 633 cpu, curthread->td_oncpu)); 634 635 PMCDBG(CPU,SEL,2, "select-cpu cpu=%d ok", cpu); 636 } 637 638 /* 639 * Force a context switch. 640 * 641 * We do this by pause'ing for 1 tick -- invoking mi_switch() is not 642 * guaranteed to force a context switch. 643 */ 644 645 static void 646 pmc_force_context_switch(void) 647 { 648 649 pause("pmcctx", 1); 650 } 651 652 /* 653 * Get the file name for an executable. This is a simple wrapper 654 * around vn_fullpath(9). 655 */ 656 657 static void 658 pmc_getfilename(struct vnode *v, char **fullpath, char **freepath) 659 { 660 struct thread *td; 661 662 td = curthread; 663 *fullpath = "unknown"; 664 *freepath = NULL; 665 vn_lock(v, LK_CANRECURSE | LK_EXCLUSIVE | LK_RETRY, td); 666 vn_fullpath(td, v, fullpath, freepath); 667 VOP_UNLOCK(v, 0, td); 668 } 669 670 /* 671 * remove an process owning PMCs 672 */ 673 674 void 675 pmc_remove_owner(struct pmc_owner *po) 676 { 677 struct pmc *pm, *tmp; 678 679 sx_assert(&pmc_sx, SX_XLOCKED); 680 681 PMCDBG(OWN,ORM,1, "remove-owner po=%p", po); 682 683 /* Remove descriptor from the owner hash table */ 684 LIST_REMOVE(po, po_next); 685 686 /* release all owned PMC descriptors */ 687 LIST_FOREACH_SAFE(pm, &po->po_pmcs, pm_next, tmp) { 688 PMCDBG(OWN,ORM,2, "pmc=%p", pm); 689 KASSERT(pm->pm_owner == po, 690 ("[pmc,%d] owner %p != po %p", __LINE__, pm->pm_owner, po)); 691 692 pmc_release_pmc_descriptor(pm); /* will unlink from the list */ 693 } 694 695 KASSERT(po->po_sscount == 0, 696 ("[pmc,%d] SS count not zero", __LINE__)); 697 KASSERT(LIST_EMPTY(&po->po_pmcs), 698 ("[pmc,%d] PMC list not empty", __LINE__)); 699 700 /* de-configure the log file if present */ 701 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 702 pmclog_deconfigure_log(po); 703 } 704 705 /* 706 * remove an owner process record if all conditions are met. 707 */ 708 709 static void 710 pmc_maybe_remove_owner(struct pmc_owner *po) 711 { 712 713 PMCDBG(OWN,OMR,1, "maybe-remove-owner po=%p", po); 714 715 /* 716 * Remove owner record if 717 * - this process does not own any PMCs 718 * - this process has not allocated a system-wide sampling buffer 719 */ 720 721 if (LIST_EMPTY(&po->po_pmcs) && 722 ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0)) { 723 pmc_remove_owner(po); 724 pmc_destroy_owner_descriptor(po); 725 } 726 } 727 728 /* 729 * Add an association between a target process and a PMC. 730 */ 731 732 static void 733 pmc_link_target_process(struct pmc *pm, struct pmc_process *pp) 734 { 735 int ri; 736 struct pmc_target *pt; 737 738 sx_assert(&pmc_sx, SX_XLOCKED); 739 740 KASSERT(pm != NULL && pp != NULL, 741 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 742 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 743 ("[pmc,%d] Attaching a non-process-virtual pmc=%p to pid=%d", 744 __LINE__, pm, pp->pp_proc->p_pid)); 745 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt < ((int) md->pmd_npmc - 1), 746 ("[pmc,%d] Illegal reference count %d for process record %p", 747 __LINE__, pp->pp_refcnt, (void *) pp)); 748 749 ri = PMC_TO_ROWINDEX(pm); 750 751 PMCDBG(PRC,TLK,1, "link-target pmc=%p ri=%d pmc-process=%p", 752 pm, ri, pp); 753 754 #ifdef DEBUG 755 LIST_FOREACH(pt, &pm->pm_targets, pt_next) 756 if (pt->pt_process == pp) 757 KASSERT(0, ("[pmc,%d] pp %p already in pmc %p targets", 758 __LINE__, pp, pm)); 759 #endif 760 761 MALLOC(pt, struct pmc_target *, sizeof(struct pmc_target), 762 M_PMC, M_ZERO|M_WAITOK); 763 764 pt->pt_process = pp; 765 766 LIST_INSERT_HEAD(&pm->pm_targets, pt, pt_next); 767 768 atomic_store_rel_ptr((uintptr_t *)&pp->pp_pmcs[ri].pp_pmc, 769 (uintptr_t)pm); 770 771 if (pm->pm_owner->po_owner == pp->pp_proc) 772 pm->pm_flags |= PMC_F_ATTACHED_TO_OWNER; 773 774 /* 775 * Initialize the per-process values at this row index. 776 */ 777 pp->pp_pmcs[ri].pp_pmcval = PMC_TO_MODE(pm) == PMC_MODE_TS ? 778 pm->pm_sc.pm_reloadcount : 0; 779 780 pp->pp_refcnt++; 781 782 } 783 784 /* 785 * Removes the association between a target process and a PMC. 786 */ 787 788 static void 789 pmc_unlink_target_process(struct pmc *pm, struct pmc_process *pp) 790 { 791 int ri; 792 struct proc *p; 793 struct pmc_target *ptgt; 794 795 sx_assert(&pmc_sx, SX_XLOCKED); 796 797 KASSERT(pm != NULL && pp != NULL, 798 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 799 800 KASSERT(pp->pp_refcnt >= 1 && pp->pp_refcnt < (int) md->pmd_npmc, 801 ("[pmc,%d] Illegal ref count %d on process record %p", 802 __LINE__, pp->pp_refcnt, (void *) pp)); 803 804 ri = PMC_TO_ROWINDEX(pm); 805 806 PMCDBG(PRC,TUL,1, "unlink-target pmc=%p ri=%d pmc-process=%p", 807 pm, ri, pp); 808 809 KASSERT(pp->pp_pmcs[ri].pp_pmc == pm, 810 ("[pmc,%d] PMC ri %d mismatch pmc %p pp->[ri] %p", __LINE__, 811 ri, pm, pp->pp_pmcs[ri].pp_pmc)); 812 813 pp->pp_pmcs[ri].pp_pmc = NULL; 814 pp->pp_pmcs[ri].pp_pmcval = (pmc_value_t) 0; 815 816 /* Remove owner-specific flags */ 817 if (pm->pm_owner->po_owner == pp->pp_proc) { 818 pp->pp_flags &= ~PMC_PP_ENABLE_MSR_ACCESS; 819 pm->pm_flags &= ~PMC_F_ATTACHED_TO_OWNER; 820 } 821 822 pp->pp_refcnt--; 823 824 /* Remove the target process from the PMC structure */ 825 LIST_FOREACH(ptgt, &pm->pm_targets, pt_next) 826 if (ptgt->pt_process == pp) 827 break; 828 829 KASSERT(ptgt != NULL, ("[pmc,%d] process %p (pp: %p) not found " 830 "in pmc %p", __LINE__, pp->pp_proc, pp, pm)); 831 832 LIST_REMOVE(ptgt, pt_next); 833 FREE(ptgt, M_PMC); 834 835 /* if the PMC now lacks targets, send the owner a SIGIO */ 836 if (LIST_EMPTY(&pm->pm_targets)) { 837 p = pm->pm_owner->po_owner; 838 PROC_LOCK(p); 839 psignal(p, SIGIO); 840 PROC_UNLOCK(p); 841 842 PMCDBG(PRC,SIG,2, "signalling proc=%p signal=%d", p, 843 SIGIO); 844 } 845 } 846 847 /* 848 * Check if PMC 'pm' may be attached to target process 't'. 849 */ 850 851 static int 852 pmc_can_attach(struct pmc *pm, struct proc *t) 853 { 854 struct proc *o; /* pmc owner */ 855 struct ucred *oc, *tc; /* owner, target credentials */ 856 int decline_attach, i; 857 858 /* 859 * A PMC's owner can always attach that PMC to itself. 860 */ 861 862 if ((o = pm->pm_owner->po_owner) == t) 863 return 0; 864 865 PROC_LOCK(o); 866 oc = o->p_ucred; 867 crhold(oc); 868 PROC_UNLOCK(o); 869 870 PROC_LOCK(t); 871 tc = t->p_ucred; 872 crhold(tc); 873 PROC_UNLOCK(t); 874 875 /* 876 * The effective uid of the PMC owner should match at least one 877 * of the {effective,real,saved} uids of the target process. 878 */ 879 880 decline_attach = oc->cr_uid != tc->cr_uid && 881 oc->cr_uid != tc->cr_svuid && 882 oc->cr_uid != tc->cr_ruid; 883 884 /* 885 * Every one of the target's group ids, must be in the owner's 886 * group list. 887 */ 888 for (i = 0; !decline_attach && i < tc->cr_ngroups; i++) 889 decline_attach = !groupmember(tc->cr_groups[i], oc); 890 891 /* check the read and saved gids too */ 892 if (decline_attach == 0) 893 decline_attach = !groupmember(tc->cr_rgid, oc) || 894 !groupmember(tc->cr_svgid, oc); 895 896 crfree(tc); 897 crfree(oc); 898 899 return !decline_attach; 900 } 901 902 /* 903 * Attach a process to a PMC. 904 */ 905 906 static int 907 pmc_attach_one_process(struct proc *p, struct pmc *pm) 908 { 909 int ri; 910 char *fullpath, *freepath; 911 struct pmc_process *pp; 912 913 sx_assert(&pmc_sx, SX_XLOCKED); 914 915 PMCDBG(PRC,ATT,2, "attach-one pm=%p ri=%d proc=%p (%d, %s)", pm, 916 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 917 918 /* 919 * Locate the process descriptor corresponding to process 'p', 920 * allocating space as needed. 921 * 922 * Verify that rowindex 'pm_rowindex' is free in the process 923 * descriptor. 924 * 925 * If not, allocate space for a descriptor and link the 926 * process descriptor and PMC. 927 */ 928 ri = PMC_TO_ROWINDEX(pm); 929 930 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_ALLOCATE)) == NULL) 931 return ENOMEM; 932 933 if (pp->pp_pmcs[ri].pp_pmc == pm) /* already present at slot [ri] */ 934 return EEXIST; 935 936 if (pp->pp_pmcs[ri].pp_pmc != NULL) 937 return EBUSY; 938 939 pmc_link_target_process(pm, pp); 940 941 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) && 942 (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) == 0) 943 pm->pm_flags |= PMC_F_NEEDS_LOGFILE; 944 945 pm->pm_flags |= PMC_F_ATTACH_DONE; /* mark as attached */ 946 947 /* issue an attach event to a configured log file */ 948 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) { 949 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 950 pmclog_process_pmcattach(pm, p->p_pid, fullpath); 951 if (freepath) 952 FREE(freepath, M_TEMP); 953 } 954 /* mark process as using HWPMCs */ 955 PROC_LOCK(p); 956 p->p_flag |= P_HWPMC; 957 PROC_UNLOCK(p); 958 959 return 0; 960 } 961 962 /* 963 * Attach a process and optionally its children 964 */ 965 966 static int 967 pmc_attach_process(struct proc *p, struct pmc *pm) 968 { 969 int error; 970 struct proc *top; 971 972 sx_assert(&pmc_sx, SX_XLOCKED); 973 974 PMCDBG(PRC,ATT,1, "attach pm=%p ri=%d proc=%p (%d, %s)", pm, 975 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 976 977 978 /* 979 * If this PMC successfully allowed a GETMSR operation 980 * in the past, disallow further ATTACHes. 981 */ 982 983 if ((pm->pm_flags & PMC_PP_ENABLE_MSR_ACCESS) != 0) 984 return EPERM; 985 986 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 987 return pmc_attach_one_process(p, pm); 988 989 /* 990 * Traverse all child processes, attaching them to 991 * this PMC. 992 */ 993 994 sx_slock(&proctree_lock); 995 996 top = p; 997 998 for (;;) { 999 if ((error = pmc_attach_one_process(p, pm)) != 0) 1000 break; 1001 if (!LIST_EMPTY(&p->p_children)) 1002 p = LIST_FIRST(&p->p_children); 1003 else for (;;) { 1004 if (p == top) 1005 goto done; 1006 if (LIST_NEXT(p, p_sibling)) { 1007 p = LIST_NEXT(p, p_sibling); 1008 break; 1009 } 1010 p = p->p_pptr; 1011 } 1012 } 1013 1014 if (error) 1015 (void) pmc_detach_process(top, pm); 1016 1017 done: 1018 sx_sunlock(&proctree_lock); 1019 return error; 1020 } 1021 1022 /* 1023 * Detach a process from a PMC. If there are no other PMCs tracking 1024 * this process, remove the process structure from its hash table. If 1025 * 'flags' contains PMC_FLAG_REMOVE, then free the process structure. 1026 */ 1027 1028 static int 1029 pmc_detach_one_process(struct proc *p, struct pmc *pm, int flags) 1030 { 1031 int ri; 1032 struct pmc_process *pp; 1033 1034 sx_assert(&pmc_sx, SX_XLOCKED); 1035 1036 KASSERT(pm != NULL, 1037 ("[pmc,%d] null pm pointer", __LINE__)); 1038 1039 ri = PMC_TO_ROWINDEX(pm); 1040 1041 PMCDBG(PRC,ATT,2, "detach-one pm=%p ri=%d proc=%p (%d, %s) flags=0x%x", 1042 pm, ri, p, p->p_pid, p->p_comm, flags); 1043 1044 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) 1045 return ESRCH; 1046 1047 if (pp->pp_pmcs[ri].pp_pmc != pm) 1048 return EINVAL; 1049 1050 pmc_unlink_target_process(pm, pp); 1051 1052 /* Issue a detach entry if a log file is configured */ 1053 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) 1054 pmclog_process_pmcdetach(pm, p->p_pid); 1055 1056 /* 1057 * If there are no PMCs targetting this process, we remove its 1058 * descriptor from the target hash table and unset the P_HWPMC 1059 * flag in the struct proc. 1060 */ 1061 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt < (int) md->pmd_npmc, 1062 ("[pmc,%d] Illegal refcnt %d for process struct %p", 1063 __LINE__, pp->pp_refcnt, pp)); 1064 1065 if (pp->pp_refcnt != 0) /* still a target of some PMC */ 1066 return 0; 1067 1068 pmc_remove_process_descriptor(pp); 1069 1070 if (flags & PMC_FLAG_REMOVE) 1071 FREE(pp, M_PMC); 1072 1073 PROC_LOCK(p); 1074 p->p_flag &= ~P_HWPMC; 1075 PROC_UNLOCK(p); 1076 1077 return 0; 1078 } 1079 1080 /* 1081 * Detach a process and optionally its descendants from a PMC. 1082 */ 1083 1084 static int 1085 pmc_detach_process(struct proc *p, struct pmc *pm) 1086 { 1087 struct proc *top; 1088 1089 sx_assert(&pmc_sx, SX_XLOCKED); 1090 1091 PMCDBG(PRC,ATT,1, "detach pm=%p ri=%d proc=%p (%d, %s)", pm, 1092 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1093 1094 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 1095 return pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); 1096 1097 /* 1098 * Traverse all children, detaching them from this PMC. We 1099 * ignore errors since we could be detaching a PMC from a 1100 * partially attached proc tree. 1101 */ 1102 1103 sx_slock(&proctree_lock); 1104 1105 top = p; 1106 1107 for (;;) { 1108 (void) pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); 1109 1110 if (!LIST_EMPTY(&p->p_children)) 1111 p = LIST_FIRST(&p->p_children); 1112 else for (;;) { 1113 if (p == top) 1114 goto done; 1115 if (LIST_NEXT(p, p_sibling)) { 1116 p = LIST_NEXT(p, p_sibling); 1117 break; 1118 } 1119 p = p->p_pptr; 1120 } 1121 } 1122 1123 done: 1124 sx_sunlock(&proctree_lock); 1125 1126 if (LIST_EMPTY(&pm->pm_targets)) 1127 pm->pm_flags &= ~PMC_F_ATTACH_DONE; 1128 1129 return 0; 1130 } 1131 1132 1133 /* 1134 * Thread context switch IN 1135 */ 1136 1137 static void 1138 pmc_process_csw_in(struct thread *td) 1139 { 1140 int cpu; 1141 unsigned int ri; 1142 struct pmc *pm; 1143 struct proc *p; 1144 struct pmc_cpu *pc; 1145 struct pmc_hw *phw; 1146 struct pmc_process *pp; 1147 pmc_value_t newvalue; 1148 1149 p = td->td_proc; 1150 1151 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE)) == NULL) 1152 return; 1153 1154 KASSERT(pp->pp_proc == td->td_proc, 1155 ("[pmc,%d] not my thread state", __LINE__)); 1156 1157 critical_enter(); /* no preemption from this point */ 1158 1159 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1160 1161 PMCDBG(CSW,SWI,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1162 p->p_pid, p->p_comm, pp); 1163 1164 KASSERT(cpu >= 0 && cpu < mp_ncpus, 1165 ("[pmc,%d] wierd CPU id %d", __LINE__, cpu)); 1166 1167 pc = pmc_pcpu[cpu]; 1168 1169 for (ri = 0; ri < md->pmd_npmc; ri++) { 1170 1171 if ((pm = pp->pp_pmcs[ri].pp_pmc) == NULL) 1172 continue; 1173 1174 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 1175 ("[pmc,%d] Target PMC in non-virtual mode (%d)", 1176 __LINE__, PMC_TO_MODE(pm))); 1177 1178 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1179 ("[pmc,%d] Row index mismatch pmc %d != ri %d", 1180 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1181 1182 /* 1183 * Only PMCs that are marked as 'RUNNING' need 1184 * be placed on hardware. 1185 */ 1186 1187 if (pm->pm_state != PMC_STATE_RUNNING) 1188 continue; 1189 1190 /* increment PMC runcount */ 1191 atomic_add_rel_32(&pm->pm_runcount, 1); 1192 1193 /* configure the HWPMC we are going to use. */ 1194 md->pmd_config_pmc(cpu, ri, pm); 1195 1196 phw = pc->pc_hwpmcs[ri]; 1197 1198 KASSERT(phw != NULL, 1199 ("[pmc,%d] null hw pointer", __LINE__)); 1200 1201 KASSERT(phw->phw_pmc == pm, 1202 ("[pmc,%d] hw->pmc %p != pmc %p", __LINE__, 1203 phw->phw_pmc, pm)); 1204 1205 /* 1206 * Write out saved value and start the PMC. 1207 * 1208 * Sampling PMCs use a per-process value, while 1209 * counting mode PMCs use a per-pmc value that is 1210 * inherited across descendants. 1211 */ 1212 if (PMC_TO_MODE(pm) == PMC_MODE_TS) { 1213 mtx_pool_lock_spin(pmc_mtxpool, pm); 1214 newvalue = PMC_PCPU_SAVED(cpu,ri) = 1215 pp->pp_pmcs[ri].pp_pmcval; 1216 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1217 } else { 1218 KASSERT(PMC_TO_MODE(pm) == PMC_MODE_TC, 1219 ("[pmc,%d] illegal mode=%d", __LINE__, 1220 PMC_TO_MODE(pm))); 1221 mtx_pool_lock_spin(pmc_mtxpool, pm); 1222 newvalue = PMC_PCPU_SAVED(cpu, ri) = 1223 pm->pm_gv.pm_savedvalue; 1224 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1225 } 1226 1227 PMCDBG(CSW,SWI,1,"cpu=%d ri=%d new=%jd", cpu, ri, newvalue); 1228 1229 md->pmd_write_pmc(cpu, ri, newvalue); 1230 md->pmd_start_pmc(cpu, ri); 1231 } 1232 1233 /* 1234 * perform any other architecture/cpu dependent thread 1235 * switch-in actions. 1236 */ 1237 1238 (void) (*md->pmd_switch_in)(pc, pp); 1239 1240 critical_exit(); 1241 1242 } 1243 1244 /* 1245 * Thread context switch OUT. 1246 */ 1247 1248 static void 1249 pmc_process_csw_out(struct thread *td) 1250 { 1251 int cpu; 1252 enum pmc_mode mode; 1253 unsigned int ri; 1254 struct pmc *pm; 1255 struct proc *p; 1256 struct pmc_cpu *pc; 1257 struct pmc_process *pp; 1258 int64_t tmp; 1259 pmc_value_t newvalue; 1260 1261 /* 1262 * Locate our process descriptor; this may be NULL if 1263 * this process is exiting and we have already removed 1264 * the process from the target process table. 1265 * 1266 * Note that due to kernel preemption, multiple 1267 * context switches may happen while the process is 1268 * exiting. 1269 * 1270 * Note also that if the target process cannot be 1271 * found we still need to deconfigure any PMCs that 1272 * are currently running on hardware. 1273 */ 1274 1275 p = td->td_proc; 1276 pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE); 1277 1278 /* 1279 * save PMCs 1280 */ 1281 1282 critical_enter(); 1283 1284 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1285 1286 PMCDBG(CSW,SWO,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1287 p->p_pid, p->p_comm, pp); 1288 1289 KASSERT(cpu >= 0 && cpu < mp_ncpus, 1290 ("[pmc,%d wierd CPU id %d", __LINE__, cpu)); 1291 1292 pc = pmc_pcpu[cpu]; 1293 1294 /* 1295 * When a PMC gets unlinked from a target PMC, it will 1296 * be removed from the target's pp_pmc[] array. 1297 * 1298 * However, on a MP system, the target could have been 1299 * executing on another CPU at the time of the unlink. 1300 * So, at context switch OUT time, we need to look at 1301 * the hardware to determine if a PMC is scheduled on 1302 * it. 1303 */ 1304 1305 for (ri = 0; ri < md->pmd_npmc; ri++) { 1306 1307 pm = NULL; 1308 (void) (*md->pmd_get_config)(cpu, ri, &pm); 1309 1310 if (pm == NULL) /* nothing at this row index */ 1311 continue; 1312 1313 mode = PMC_TO_MODE(pm); 1314 if (!PMC_IS_VIRTUAL_MODE(mode)) 1315 continue; /* not a process virtual PMC */ 1316 1317 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1318 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 1319 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1320 1321 /* Stop hardware if not already stopped */ 1322 if (pm->pm_stalled == 0) 1323 md->pmd_stop_pmc(cpu, ri); 1324 1325 /* reduce this PMC's runcount */ 1326 atomic_subtract_rel_32(&pm->pm_runcount, 1); 1327 1328 /* 1329 * If this PMC is associated with this process, 1330 * save the reading. 1331 */ 1332 1333 if (pp != NULL && pp->pp_pmcs[ri].pp_pmc != NULL) { 1334 1335 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 1336 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", __LINE__, 1337 pm, ri, pp->pp_pmcs[ri].pp_pmc)); 1338 1339 KASSERT(pp->pp_refcnt > 0, 1340 ("[pmc,%d] pp refcnt = %d", __LINE__, 1341 pp->pp_refcnt)); 1342 1343 md->pmd_read_pmc(cpu, ri, &newvalue); 1344 1345 tmp = newvalue - PMC_PCPU_SAVED(cpu,ri); 1346 1347 PMCDBG(CSW,SWI,1,"cpu=%d ri=%d tmp=%jd", cpu, ri, 1348 tmp); 1349 1350 if (mode == PMC_MODE_TS) { 1351 1352 /* 1353 * For sampling process-virtual PMCs, 1354 * we expect the count to be 1355 * decreasing as the 'value' 1356 * programmed into the PMC is the 1357 * number of events to be seen till 1358 * the next sampling interrupt. 1359 */ 1360 if (tmp < 0) 1361 tmp += pm->pm_sc.pm_reloadcount; 1362 mtx_pool_lock_spin(pmc_mtxpool, pm); 1363 pp->pp_pmcs[ri].pp_pmcval -= tmp; 1364 if ((int64_t) pp->pp_pmcs[ri].pp_pmcval < 0) 1365 pp->pp_pmcs[ri].pp_pmcval += 1366 pm->pm_sc.pm_reloadcount; 1367 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1368 1369 } else { 1370 1371 /* 1372 * For counting process-virtual PMCs, 1373 * we expect the count to be 1374 * increasing monotonically, modulo a 64 1375 * bit wraparound. 1376 */ 1377 KASSERT((int64_t) tmp >= 0, 1378 ("[pmc,%d] negative increment cpu=%d " 1379 "ri=%d newvalue=%jx saved=%jx " 1380 "incr=%jx", __LINE__, cpu, ri, 1381 newvalue, PMC_PCPU_SAVED(cpu,ri), tmp)); 1382 1383 mtx_pool_lock_spin(pmc_mtxpool, pm); 1384 pm->pm_gv.pm_savedvalue += tmp; 1385 pp->pp_pmcs[ri].pp_pmcval += tmp; 1386 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1387 1388 if (pm->pm_flags & PMC_F_LOG_PROCCSW) 1389 pmclog_process_proccsw(pm, pp, tmp); 1390 } 1391 } 1392 1393 /* mark hardware as free */ 1394 md->pmd_config_pmc(cpu, ri, NULL); 1395 } 1396 1397 /* 1398 * perform any other architecture/cpu dependent thread 1399 * switch out functions. 1400 */ 1401 1402 (void) (*md->pmd_switch_out)(pc, pp); 1403 1404 critical_exit(); 1405 } 1406 1407 /* 1408 * Log a KLD operation. 1409 */ 1410 1411 static void 1412 pmc_process_kld_load(struct pmckern_map_in *pkm) 1413 { 1414 struct pmc_owner *po; 1415 1416 sx_assert(&pmc_sx, SX_LOCKED); 1417 1418 /* 1419 * Notify owners of system sampling PMCs about KLD operations. 1420 */ 1421 1422 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1423 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1424 pmclog_process_map_in(po, (pid_t) -1, pkm->pm_address, 1425 (char *) pkm->pm_file); 1426 1427 /* 1428 * TODO: Notify owners of (all) process-sampling PMCs too. 1429 */ 1430 1431 return; 1432 } 1433 1434 static void 1435 pmc_process_kld_unload(struct pmckern_map_out *pkm) 1436 { 1437 struct pmc_owner *po; 1438 1439 sx_assert(&pmc_sx, SX_LOCKED); 1440 1441 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1442 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1443 pmclog_process_map_out(po, (pid_t) -1, 1444 pkm->pm_address, pkm->pm_address + pkm->pm_size); 1445 1446 /* 1447 * TODO: Notify owners of process-sampling PMCs. 1448 */ 1449 } 1450 1451 /* 1452 * A mapping change for a process. 1453 */ 1454 1455 static void 1456 pmc_process_mmap(struct thread *td, struct pmckern_map_in *pkm) 1457 { 1458 int ri; 1459 pid_t pid; 1460 char *fullpath, *freepath; 1461 const struct pmc *pm; 1462 struct pmc_owner *po; 1463 const struct pmc_process *pp; 1464 1465 freepath = fullpath = NULL; 1466 pmc_getfilename((struct vnode *) pkm->pm_file, &fullpath, &freepath); 1467 1468 pid = td->td_proc->p_pid; 1469 1470 /* Inform owners of all system-wide sampling PMCs. */ 1471 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1472 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1473 pmclog_process_map_in(po, pid, pkm->pm_address, fullpath); 1474 1475 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1476 goto done; 1477 1478 /* 1479 * Inform sampling PMC owners tracking this process. 1480 */ 1481 for (ri = 0; ri < md->pmd_npmc; ri++) 1482 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1483 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1484 pmclog_process_map_in(pm->pm_owner, 1485 pid, pkm->pm_address, fullpath); 1486 1487 done: 1488 if (freepath) 1489 FREE(freepath, M_TEMP); 1490 } 1491 1492 1493 /* 1494 * Log an munmap request. 1495 */ 1496 1497 static void 1498 pmc_process_munmap(struct thread *td, struct pmckern_map_out *pkm) 1499 { 1500 int ri; 1501 pid_t pid; 1502 struct pmc_owner *po; 1503 const struct pmc *pm; 1504 const struct pmc_process *pp; 1505 1506 pid = td->td_proc->p_pid; 1507 1508 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1509 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1510 pmclog_process_map_out(po, pid, pkm->pm_address, 1511 pkm->pm_address + pkm->pm_size); 1512 1513 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1514 return; 1515 1516 for (ri = 0; ri < md->pmd_npmc; ri++) 1517 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1518 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1519 pmclog_process_map_out(pm->pm_owner, pid, 1520 pkm->pm_address, pkm->pm_address + pkm->pm_size); 1521 } 1522 1523 /* 1524 * The 'hook' invoked from the kernel proper 1525 */ 1526 1527 1528 #ifdef DEBUG 1529 const char *pmc_hooknames[] = { 1530 /* these strings correspond to PMC_FN_* in <sys/pmckern.h> */ 1531 "", 1532 "EXEC", 1533 "CSW-IN", 1534 "CSW-OUT", 1535 "SAMPLE", 1536 "KLDLOAD", 1537 "KLDUNLOAD", 1538 "MMAP", 1539 "MUNMAP" 1540 }; 1541 #endif 1542 1543 static int 1544 pmc_hook_handler(struct thread *td, int function, void *arg) 1545 { 1546 1547 PMCDBG(MOD,PMH,1, "hook td=%p func=%d \"%s\" arg=%p", td, function, 1548 pmc_hooknames[function], arg); 1549 1550 switch (function) 1551 { 1552 1553 /* 1554 * Process exec() 1555 */ 1556 1557 case PMC_FN_PROCESS_EXEC: 1558 { 1559 char *fullpath, *freepath; 1560 unsigned int ri; 1561 int is_using_hwpmcs; 1562 struct pmc *pm; 1563 struct proc *p; 1564 struct pmc_owner *po; 1565 struct pmc_process *pp; 1566 struct pmckern_procexec *pk; 1567 1568 sx_assert(&pmc_sx, SX_XLOCKED); 1569 1570 p = td->td_proc; 1571 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 1572 1573 pk = (struct pmckern_procexec *) arg; 1574 1575 /* Inform owners of SS mode PMCs of the exec event. */ 1576 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1577 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1578 pmclog_process_procexec(po, PMC_ID_INVALID, 1579 p->p_pid, pk->pm_entryaddr, fullpath); 1580 1581 PROC_LOCK(p); 1582 is_using_hwpmcs = p->p_flag & P_HWPMC; 1583 PROC_UNLOCK(p); 1584 1585 if (!is_using_hwpmcs) { 1586 if (freepath) 1587 FREE(freepath, M_TEMP); 1588 break; 1589 } 1590 1591 /* 1592 * PMCs are not inherited across an exec(): remove any 1593 * PMCs that this process is the owner of. 1594 */ 1595 1596 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 1597 pmc_remove_owner(po); 1598 pmc_destroy_owner_descriptor(po); 1599 } 1600 1601 /* 1602 * If the process being exec'ed is not the target of any 1603 * PMC, we are done. 1604 */ 1605 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) { 1606 if (freepath) 1607 FREE(freepath, M_TEMP); 1608 break; 1609 } 1610 1611 /* 1612 * Log the exec event to all monitoring owners. Skip 1613 * owners who have already recieved the event because 1614 * they had system sampling PMCs active. 1615 */ 1616 for (ri = 0; ri < md->pmd_npmc; ri++) 1617 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 1618 po = pm->pm_owner; 1619 if (po->po_sscount == 0 && 1620 po->po_flags & PMC_PO_OWNS_LOGFILE) 1621 pmclog_process_procexec(po, pm->pm_id, 1622 p->p_pid, pk->pm_entryaddr, 1623 fullpath); 1624 } 1625 1626 if (freepath) 1627 FREE(freepath, M_TEMP); 1628 1629 1630 PMCDBG(PRC,EXC,1, "exec proc=%p (%d, %s) cred-changed=%d", 1631 p, p->p_pid, p->p_comm, pk->pm_credentialschanged); 1632 1633 if (pk->pm_credentialschanged == 0) /* no change */ 1634 break; 1635 1636 /* 1637 * If the newly exec()'ed process has a different credential 1638 * than before, allow it to be the target of a PMC only if 1639 * the PMC's owner has sufficient priviledge. 1640 */ 1641 1642 for (ri = 0; ri < md->pmd_npmc; ri++) 1643 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) 1644 if (pmc_can_attach(pm, td->td_proc) != 0) 1645 pmc_detach_one_process(td->td_proc, 1646 pm, PMC_FLAG_NONE); 1647 1648 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt < (int) md->pmd_npmc, 1649 ("[pmc,%d] Illegal ref count %d on pp %p", __LINE__, 1650 pp->pp_refcnt, pp)); 1651 1652 /* 1653 * If this process is no longer the target of any 1654 * PMCs, we can remove the process entry and free 1655 * up space. 1656 */ 1657 1658 if (pp->pp_refcnt == 0) { 1659 pmc_remove_process_descriptor(pp); 1660 FREE(pp, M_PMC); 1661 break; 1662 } 1663 1664 } 1665 break; 1666 1667 case PMC_FN_CSW_IN: 1668 pmc_process_csw_in(td); 1669 break; 1670 1671 case PMC_FN_CSW_OUT: 1672 pmc_process_csw_out(td); 1673 break; 1674 1675 /* 1676 * Process accumulated PC samples. 1677 * 1678 * This function is expected to be called by hardclock() for 1679 * each CPU that has accumulated PC samples. 1680 * 1681 * This function is to be executed on the CPU whose samples 1682 * are being processed. 1683 */ 1684 case PMC_FN_DO_SAMPLES: 1685 1686 /* 1687 * Clear the cpu specific bit in the CPU mask before 1688 * do the rest of the processing. If the NMI handler 1689 * gets invoked after the "atomic_clear_int()" call 1690 * below but before "pmc_process_samples()" gets 1691 * around to processing the interrupt, then we will 1692 * come back here at the next hardclock() tick (and 1693 * may find nothing to do if "pmc_process_samples()" 1694 * had already processed the interrupt). We don't 1695 * lose the interrupt sample. 1696 */ 1697 atomic_clear_int(&pmc_cpumask, (1 << PCPU_GET(cpuid))); 1698 pmc_process_samples(PCPU_GET(cpuid)); 1699 break; 1700 1701 1702 case PMC_FN_KLD_LOAD: 1703 sx_assert(&pmc_sx, SX_LOCKED); 1704 pmc_process_kld_load((struct pmckern_map_in *) arg); 1705 break; 1706 1707 case PMC_FN_KLD_UNLOAD: 1708 sx_assert(&pmc_sx, SX_LOCKED); 1709 pmc_process_kld_unload((struct pmckern_map_out *) arg); 1710 break; 1711 1712 case PMC_FN_MMAP: 1713 sx_assert(&pmc_sx, SX_LOCKED); 1714 pmc_process_mmap(td, (struct pmckern_map_in *) arg); 1715 break; 1716 1717 case PMC_FN_MUNMAP: 1718 sx_assert(&pmc_sx, SX_LOCKED); 1719 pmc_process_munmap(td, (struct pmckern_map_out *) arg); 1720 break; 1721 1722 default: 1723 #ifdef DEBUG 1724 KASSERT(0, ("[pmc,%d] unknown hook %d\n", __LINE__, function)); 1725 #endif 1726 break; 1727 1728 } 1729 1730 return 0; 1731 } 1732 1733 /* 1734 * allocate a 'struct pmc_owner' descriptor in the owner hash table. 1735 */ 1736 1737 static struct pmc_owner * 1738 pmc_allocate_owner_descriptor(struct proc *p) 1739 { 1740 uint32_t hindex; 1741 struct pmc_owner *po; 1742 struct pmc_ownerhash *poh; 1743 1744 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 1745 poh = &pmc_ownerhash[hindex]; 1746 1747 /* allocate space for N pointers and one descriptor struct */ 1748 MALLOC(po, struct pmc_owner *, sizeof(struct pmc_owner), 1749 M_PMC, M_ZERO|M_WAITOK); 1750 1751 po->po_sscount = po->po_error = po->po_flags = 0; 1752 po->po_file = NULL; 1753 po->po_owner = p; 1754 po->po_kthread = NULL; 1755 LIST_INIT(&po->po_pmcs); 1756 LIST_INSERT_HEAD(poh, po, po_next); /* insert into hash table */ 1757 1758 TAILQ_INIT(&po->po_logbuffers); 1759 mtx_init(&po->po_mtx, "pmc-owner-mtx", "pmc", MTX_SPIN); 1760 1761 PMCDBG(OWN,ALL,1, "allocate-owner proc=%p (%d, %s) pmc-owner=%p", 1762 p, p->p_pid, p->p_comm, po); 1763 1764 return po; 1765 } 1766 1767 static void 1768 pmc_destroy_owner_descriptor(struct pmc_owner *po) 1769 { 1770 1771 PMCDBG(OWN,REL,1, "destroy-owner po=%p proc=%p (%d, %s)", 1772 po, po->po_owner, po->po_owner->p_pid, po->po_owner->p_comm); 1773 1774 mtx_destroy(&po->po_mtx); 1775 FREE(po, M_PMC); 1776 } 1777 1778 /* 1779 * find the descriptor corresponding to process 'p', adding or removing it 1780 * as specified by 'mode'. 1781 */ 1782 1783 static struct pmc_process * 1784 pmc_find_process_descriptor(struct proc *p, uint32_t mode) 1785 { 1786 uint32_t hindex; 1787 struct pmc_process *pp, *ppnew; 1788 struct pmc_processhash *pph; 1789 1790 hindex = PMC_HASH_PTR(p, pmc_processhashmask); 1791 pph = &pmc_processhash[hindex]; 1792 1793 ppnew = NULL; 1794 1795 /* 1796 * Pre-allocate memory in the FIND_ALLOCATE case since we 1797 * cannot call malloc(9) once we hold a spin lock. 1798 */ 1799 1800 if (mode & PMC_FLAG_ALLOCATE) { 1801 /* allocate additional space for 'n' pmc pointers */ 1802 MALLOC(ppnew, struct pmc_process *, 1803 sizeof(struct pmc_process) + md->pmd_npmc * 1804 sizeof(struct pmc_targetstate), M_PMC, M_ZERO|M_WAITOK); 1805 } 1806 1807 mtx_lock_spin(&pmc_processhash_mtx); 1808 LIST_FOREACH(pp, pph, pp_next) 1809 if (pp->pp_proc == p) 1810 break; 1811 1812 if ((mode & PMC_FLAG_REMOVE) && pp != NULL) 1813 LIST_REMOVE(pp, pp_next); 1814 1815 if ((mode & PMC_FLAG_ALLOCATE) && pp == NULL && 1816 ppnew != NULL) { 1817 ppnew->pp_proc = p; 1818 LIST_INSERT_HEAD(pph, ppnew, pp_next); 1819 pp = ppnew; 1820 ppnew = NULL; 1821 } 1822 mtx_unlock_spin(&pmc_processhash_mtx); 1823 1824 if (pp != NULL && ppnew != NULL) 1825 FREE(ppnew, M_PMC); 1826 1827 return pp; 1828 } 1829 1830 /* 1831 * remove a process descriptor from the process hash table. 1832 */ 1833 1834 static void 1835 pmc_remove_process_descriptor(struct pmc_process *pp) 1836 { 1837 KASSERT(pp->pp_refcnt == 0, 1838 ("[pmc,%d] Removing process descriptor %p with count %d", 1839 __LINE__, pp, pp->pp_refcnt)); 1840 1841 mtx_lock_spin(&pmc_processhash_mtx); 1842 LIST_REMOVE(pp, pp_next); 1843 mtx_unlock_spin(&pmc_processhash_mtx); 1844 } 1845 1846 1847 /* 1848 * find an owner descriptor corresponding to proc 'p' 1849 */ 1850 1851 static struct pmc_owner * 1852 pmc_find_owner_descriptor(struct proc *p) 1853 { 1854 uint32_t hindex; 1855 struct pmc_owner *po; 1856 struct pmc_ownerhash *poh; 1857 1858 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 1859 poh = &pmc_ownerhash[hindex]; 1860 1861 po = NULL; 1862 LIST_FOREACH(po, poh, po_next) 1863 if (po->po_owner == p) 1864 break; 1865 1866 PMCDBG(OWN,FND,1, "find-owner proc=%p (%d, %s) hindex=0x%x -> " 1867 "pmc-owner=%p", p, p->p_pid, p->p_comm, hindex, po); 1868 1869 return po; 1870 } 1871 1872 /* 1873 * pmc_allocate_pmc_descriptor 1874 * 1875 * Allocate a pmc descriptor and initialize its 1876 * fields. 1877 */ 1878 1879 static struct pmc * 1880 pmc_allocate_pmc_descriptor(void) 1881 { 1882 struct pmc *pmc; 1883 1884 MALLOC(pmc, struct pmc *, sizeof(struct pmc), M_PMC, M_ZERO|M_WAITOK); 1885 1886 if (pmc != NULL) { 1887 pmc->pm_owner = NULL; 1888 LIST_INIT(&pmc->pm_targets); 1889 } 1890 1891 PMCDBG(PMC,ALL,1, "allocate-pmc -> pmc=%p", pmc); 1892 1893 return pmc; 1894 } 1895 1896 /* 1897 * Destroy a pmc descriptor. 1898 */ 1899 1900 static void 1901 pmc_destroy_pmc_descriptor(struct pmc *pm) 1902 { 1903 (void) pm; 1904 1905 #ifdef DEBUG 1906 KASSERT(pm->pm_state == PMC_STATE_DELETED || 1907 pm->pm_state == PMC_STATE_FREE, 1908 ("[pmc,%d] destroying non-deleted PMC", __LINE__)); 1909 KASSERT(LIST_EMPTY(&pm->pm_targets), 1910 ("[pmc,%d] destroying pmc with targets", __LINE__)); 1911 KASSERT(pm->pm_owner == NULL, 1912 ("[pmc,%d] destroying pmc attached to an owner", __LINE__)); 1913 KASSERT(pm->pm_runcount == 0, 1914 ("[pmc,%d] pmc has non-zero run count %d", __LINE__, 1915 pm->pm_runcount)); 1916 #endif 1917 } 1918 1919 static void 1920 pmc_wait_for_pmc_idle(struct pmc *pm) 1921 { 1922 #ifdef DEBUG 1923 volatile int maxloop; 1924 1925 maxloop = 100 * mp_ncpus; 1926 #endif 1927 1928 /* 1929 * Loop (with a forced context switch) till the PMC's runcount 1930 * comes down to zero. 1931 */ 1932 while (atomic_load_acq_32(&pm->pm_runcount) > 0) { 1933 #ifdef DEBUG 1934 maxloop--; 1935 KASSERT(maxloop > 0, 1936 ("[pmc,%d] (ri%d, rc%d) waiting too long for " 1937 "pmc to be free", __LINE__, 1938 PMC_TO_ROWINDEX(pm), pm->pm_runcount)); 1939 #endif 1940 pmc_force_context_switch(); 1941 } 1942 } 1943 1944 /* 1945 * This function does the following things: 1946 * 1947 * - detaches the PMC from hardware 1948 * - unlinks all target threads that were attached to it 1949 * - removes the PMC from its owner's list 1950 * - destroy's the PMC private mutex 1951 * 1952 * Once this function completes, the given pmc pointer can be safely 1953 * FREE'd by the caller. 1954 */ 1955 1956 static void 1957 pmc_release_pmc_descriptor(struct pmc *pm) 1958 { 1959 u_int ri, cpu; 1960 enum pmc_mode mode; 1961 struct pmc_hw *phw; 1962 struct pmc_owner *po; 1963 struct pmc_process *pp; 1964 struct pmc_target *ptgt, *tmp; 1965 struct pmc_binding pb; 1966 1967 sx_assert(&pmc_sx, SX_XLOCKED); 1968 1969 KASSERT(pm, ("[pmc,%d] null pmc", __LINE__)); 1970 1971 ri = PMC_TO_ROWINDEX(pm); 1972 mode = PMC_TO_MODE(pm); 1973 1974 PMCDBG(PMC,REL,1, "release-pmc pmc=%p ri=%d mode=%d", pm, ri, 1975 mode); 1976 1977 /* 1978 * First, we take the PMC off hardware. 1979 */ 1980 cpu = 0; 1981 if (PMC_IS_SYSTEM_MODE(mode)) { 1982 1983 /* 1984 * A system mode PMC runs on a specific CPU. Switch 1985 * to this CPU and turn hardware off. 1986 */ 1987 pmc_save_cpu_binding(&pb); 1988 1989 cpu = PMC_TO_CPU(pm); 1990 1991 pmc_select_cpu(cpu); 1992 1993 /* switch off non-stalled CPUs */ 1994 if (pm->pm_state == PMC_STATE_RUNNING && 1995 pm->pm_stalled == 0) { 1996 1997 phw = pmc_pcpu[cpu]->pc_hwpmcs[ri]; 1998 1999 KASSERT(phw->phw_pmc == pm, 2000 ("[pmc, %d] pmc ptr ri(%d) hw(%p) pm(%p)", 2001 __LINE__, ri, phw->phw_pmc, pm)); 2002 PMCDBG(PMC,REL,2, "stopping cpu=%d ri=%d", cpu, ri); 2003 2004 critical_enter(); 2005 md->pmd_stop_pmc(cpu, ri); 2006 critical_exit(); 2007 } 2008 2009 PMCDBG(PMC,REL,2, "decfg cpu=%d ri=%d", cpu, ri); 2010 2011 critical_enter(); 2012 md->pmd_config_pmc(cpu, ri, NULL); 2013 critical_exit(); 2014 2015 /* adjust the global and process count of SS mode PMCs */ 2016 if (mode == PMC_MODE_SS && pm->pm_state == PMC_STATE_RUNNING) { 2017 po = pm->pm_owner; 2018 po->po_sscount--; 2019 if (po->po_sscount == 0) { 2020 atomic_subtract_rel_int(&pmc_ss_count, 1); 2021 LIST_REMOVE(po, po_ssnext); 2022 } 2023 } 2024 2025 pm->pm_state = PMC_STATE_DELETED; 2026 2027 pmc_restore_cpu_binding(&pb); 2028 2029 /* 2030 * We could have references to this PMC structure in 2031 * the per-cpu sample queues. Wait for the queue to 2032 * drain. 2033 */ 2034 pmc_wait_for_pmc_idle(pm); 2035 2036 } else if (PMC_IS_VIRTUAL_MODE(mode)) { 2037 2038 /* 2039 * A virtual PMC could be running on multiple CPUs at 2040 * a given instant. 2041 * 2042 * By marking its state as DELETED, we ensure that 2043 * this PMC is never further scheduled on hardware. 2044 * 2045 * Then we wait till all CPUs are done with this PMC. 2046 */ 2047 pm->pm_state = PMC_STATE_DELETED; 2048 2049 2050 /* Wait for the PMCs runcount to come to zero. */ 2051 pmc_wait_for_pmc_idle(pm); 2052 2053 /* 2054 * At this point the PMC is off all CPUs and cannot be 2055 * freshly scheduled onto a CPU. It is now safe to 2056 * unlink all targets from this PMC. If a 2057 * process-record's refcount falls to zero, we remove 2058 * it from the hash table. The module-wide SX lock 2059 * protects us from races. 2060 */ 2061 LIST_FOREACH_SAFE(ptgt, &pm->pm_targets, pt_next, tmp) { 2062 pp = ptgt->pt_process; 2063 pmc_unlink_target_process(pm, pp); /* frees 'ptgt' */ 2064 2065 PMCDBG(PMC,REL,3, "pp->refcnt=%d", pp->pp_refcnt); 2066 2067 /* 2068 * If the target process record shows that no 2069 * PMCs are attached to it, reclaim its space. 2070 */ 2071 2072 if (pp->pp_refcnt == 0) { 2073 pmc_remove_process_descriptor(pp); 2074 FREE(pp, M_PMC); 2075 } 2076 } 2077 2078 cpu = curthread->td_oncpu; /* setup cpu for pmd_release() */ 2079 2080 } 2081 2082 /* 2083 * Release any MD resources 2084 */ 2085 2086 (void) md->pmd_release_pmc(cpu, ri, pm); 2087 2088 /* 2089 * Update row disposition 2090 */ 2091 2092 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) 2093 PMC_UNMARK_ROW_STANDALONE(ri); 2094 else 2095 PMC_UNMARK_ROW_THREAD(ri); 2096 2097 /* unlink from the owner's list */ 2098 if (pm->pm_owner) { 2099 LIST_REMOVE(pm, pm_next); 2100 pm->pm_owner = NULL; 2101 } 2102 2103 pmc_destroy_pmc_descriptor(pm); 2104 } 2105 2106 /* 2107 * Register an owner and a pmc. 2108 */ 2109 2110 static int 2111 pmc_register_owner(struct proc *p, struct pmc *pmc) 2112 { 2113 struct pmc_owner *po; 2114 2115 sx_assert(&pmc_sx, SX_XLOCKED); 2116 2117 if ((po = pmc_find_owner_descriptor(p)) == NULL) 2118 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) 2119 return ENOMEM; 2120 2121 KASSERT(pmc->pm_owner == NULL, 2122 ("[pmc,%d] attempting to own an initialized PMC", __LINE__)); 2123 pmc->pm_owner = po; 2124 2125 LIST_INSERT_HEAD(&po->po_pmcs, pmc, pm_next); 2126 2127 PROC_LOCK(p); 2128 p->p_flag |= P_HWPMC; 2129 PROC_UNLOCK(p); 2130 2131 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 2132 pmclog_process_pmcallocate(pmc); 2133 2134 PMCDBG(PMC,REG,1, "register-owner pmc-owner=%p pmc=%p", 2135 po, pmc); 2136 2137 return 0; 2138 } 2139 2140 /* 2141 * Return the current row disposition: 2142 * == 0 => FREE 2143 * > 0 => PROCESS MODE 2144 * < 0 => SYSTEM MODE 2145 */ 2146 2147 int 2148 pmc_getrowdisp(int ri) 2149 { 2150 return pmc_pmcdisp[ri]; 2151 } 2152 2153 /* 2154 * Check if a PMC at row index 'ri' can be allocated to the current 2155 * process. 2156 * 2157 * Allocation can fail if: 2158 * - the current process is already being profiled by a PMC at index 'ri', 2159 * attached to it via OP_PMCATTACH. 2160 * - the current process has already allocated a PMC at index 'ri' 2161 * via OP_ALLOCATE. 2162 */ 2163 2164 static int 2165 pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, int cpu) 2166 { 2167 enum pmc_mode mode; 2168 struct pmc *pm; 2169 struct pmc_owner *po; 2170 struct pmc_process *pp; 2171 2172 PMCDBG(PMC,ALR,1, "can-allocate-rowindex proc=%p (%d, %s) ri=%d " 2173 "cpu=%d", p, p->p_pid, p->p_comm, ri, cpu); 2174 2175 /* 2176 * We shouldn't have already allocated a process-mode PMC at 2177 * row index 'ri'. 2178 * 2179 * We shouldn't have allocated a system-wide PMC on the same 2180 * CPU and same RI. 2181 */ 2182 if ((po = pmc_find_owner_descriptor(p)) != NULL) 2183 LIST_FOREACH(pm, &po->po_pmcs, pm_next) { 2184 if (PMC_TO_ROWINDEX(pm) == ri) { 2185 mode = PMC_TO_MODE(pm); 2186 if (PMC_IS_VIRTUAL_MODE(mode)) 2187 return EEXIST; 2188 if (PMC_IS_SYSTEM_MODE(mode) && 2189 (int) PMC_TO_CPU(pm) == cpu) 2190 return EEXIST; 2191 } 2192 } 2193 2194 /* 2195 * We also shouldn't be the target of any PMC at this index 2196 * since otherwise a PMC_ATTACH to ourselves will fail. 2197 */ 2198 if ((pp = pmc_find_process_descriptor(p, 0)) != NULL) 2199 if (pp->pp_pmcs[ri].pp_pmc) 2200 return EEXIST; 2201 2202 PMCDBG(PMC,ALR,2, "can-allocate-rowindex proc=%p (%d, %s) ri=%d ok", 2203 p, p->p_pid, p->p_comm, ri); 2204 2205 return 0; 2206 } 2207 2208 /* 2209 * Check if a given PMC at row index 'ri' can be currently used in 2210 * mode 'mode'. 2211 */ 2212 2213 static int 2214 pmc_can_allocate_row(int ri, enum pmc_mode mode) 2215 { 2216 enum pmc_disp disp; 2217 2218 sx_assert(&pmc_sx, SX_XLOCKED); 2219 2220 PMCDBG(PMC,ALR,1, "can-allocate-row ri=%d mode=%d", ri, mode); 2221 2222 if (PMC_IS_SYSTEM_MODE(mode)) 2223 disp = PMC_DISP_STANDALONE; 2224 else 2225 disp = PMC_DISP_THREAD; 2226 2227 /* 2228 * check disposition for PMC row 'ri': 2229 * 2230 * Expected disposition Row-disposition Result 2231 * 2232 * STANDALONE STANDALONE or FREE proceed 2233 * STANDALONE THREAD fail 2234 * THREAD THREAD or FREE proceed 2235 * THREAD STANDALONE fail 2236 */ 2237 2238 if (!PMC_ROW_DISP_IS_FREE(ri) && 2239 !(disp == PMC_DISP_THREAD && PMC_ROW_DISP_IS_THREAD(ri)) && 2240 !(disp == PMC_DISP_STANDALONE && PMC_ROW_DISP_IS_STANDALONE(ri))) 2241 return EBUSY; 2242 2243 /* 2244 * All OK 2245 */ 2246 2247 PMCDBG(PMC,ALR,2, "can-allocate-row ri=%d mode=%d ok", ri, mode); 2248 2249 return 0; 2250 2251 } 2252 2253 /* 2254 * Find a PMC descriptor with user handle 'pmcid' for thread 'td'. 2255 */ 2256 2257 static struct pmc * 2258 pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, pmc_id_t pmcid) 2259 { 2260 struct pmc *pm; 2261 2262 KASSERT(PMC_ID_TO_ROWINDEX(pmcid) < md->pmd_npmc, 2263 ("[pmc,%d] Illegal pmc index %d (max %d)", __LINE__, 2264 PMC_ID_TO_ROWINDEX(pmcid), md->pmd_npmc)); 2265 2266 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 2267 if (pm->pm_id == pmcid) 2268 return pm; 2269 2270 return NULL; 2271 } 2272 2273 static int 2274 pmc_find_pmc(pmc_id_t pmcid, struct pmc **pmc) 2275 { 2276 2277 struct pmc *pm; 2278 struct pmc_owner *po; 2279 2280 PMCDBG(PMC,FND,1, "find-pmc id=%d", pmcid); 2281 2282 if ((po = pmc_find_owner_descriptor(curthread->td_proc)) == NULL) 2283 return ESRCH; 2284 2285 if ((pm = pmc_find_pmc_descriptor_in_process(po, pmcid)) == NULL) 2286 return EINVAL; 2287 2288 PMCDBG(PMC,FND,2, "find-pmc id=%d -> pmc=%p", pmcid, pm); 2289 2290 *pmc = pm; 2291 return 0; 2292 } 2293 2294 /* 2295 * Start a PMC. 2296 */ 2297 2298 static int 2299 pmc_start(struct pmc *pm) 2300 { 2301 int error, cpu, ri; 2302 enum pmc_mode mode; 2303 struct pmc_owner *po; 2304 struct pmc_binding pb; 2305 2306 KASSERT(pm != NULL, 2307 ("[pmc,%d] null pm", __LINE__)); 2308 2309 mode = PMC_TO_MODE(pm); 2310 ri = PMC_TO_ROWINDEX(pm); 2311 error = 0; 2312 2313 PMCDBG(PMC,OPS,1, "start pmc=%p mode=%d ri=%d", pm, mode, ri); 2314 2315 po = pm->pm_owner; 2316 2317 if (PMC_IS_VIRTUAL_MODE(mode)) { 2318 2319 /* 2320 * If a PMCATTACH has never been done on this PMC, 2321 * attach it to its owner process. 2322 */ 2323 2324 if (LIST_EMPTY(&pm->pm_targets)) 2325 error = (pm->pm_flags & PMC_F_ATTACH_DONE) ? ESRCH : 2326 pmc_attach_process(po->po_owner, pm); 2327 2328 /* 2329 * Disallow PMCSTART if a logfile is required but has not 2330 * been configured yet. 2331 */ 2332 2333 if (error == 0 && (pm->pm_flags & PMC_F_NEEDS_LOGFILE) && 2334 (po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) 2335 error = EDOOFUS; 2336 2337 /* 2338 * If the PMC is attached to its owner, then force a context 2339 * switch to ensure that the MD state gets set correctly. 2340 */ 2341 2342 if (error == 0) { 2343 pm->pm_state = PMC_STATE_RUNNING; 2344 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) 2345 pmc_force_context_switch(); 2346 } 2347 2348 return error; 2349 } 2350 2351 2352 /* 2353 * A system-wide PMC. 2354 */ 2355 2356 if ((pm->pm_flags & PMC_F_NEEDS_LOGFILE) && 2357 (po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) 2358 return EDOOFUS; /* programming error */ 2359 2360 /* 2361 * Add the owner to the global list if this is a system-wide 2362 * sampling PMC. 2363 */ 2364 2365 if (mode == PMC_MODE_SS) { 2366 if (po->po_sscount == 0) { 2367 LIST_INSERT_HEAD(&pmc_ss_owners, po, po_ssnext); 2368 atomic_add_rel_int(&pmc_ss_count, 1); 2369 PMCDBG(PMC,OPS,1, "po=%p in global list", po); 2370 } 2371 po->po_sscount++; 2372 } 2373 2374 /* TODO: dump system wide process mappings to the log? */ 2375 2376 /* 2377 * Move to the CPU associated with this 2378 * PMC, and start the hardware. 2379 */ 2380 2381 pmc_save_cpu_binding(&pb); 2382 2383 cpu = PMC_TO_CPU(pm); 2384 2385 if (pmc_cpu_is_disabled(cpu)) 2386 return ENXIO; 2387 2388 pmc_select_cpu(cpu); 2389 2390 /* 2391 * global PMCs are configured at allocation time 2392 * so write out the initial value and start the PMC. 2393 */ 2394 2395 pm->pm_state = PMC_STATE_RUNNING; 2396 2397 critical_enter(); 2398 if ((error = md->pmd_write_pmc(cpu, ri, 2399 PMC_IS_SAMPLING_MODE(mode) ? 2400 pm->pm_sc.pm_reloadcount : 2401 pm->pm_sc.pm_initial)) == 0) 2402 error = md->pmd_start_pmc(cpu, ri); 2403 critical_exit(); 2404 2405 pmc_restore_cpu_binding(&pb); 2406 2407 return error; 2408 } 2409 2410 /* 2411 * Stop a PMC. 2412 */ 2413 2414 static int 2415 pmc_stop(struct pmc *pm) 2416 { 2417 int cpu, error, ri; 2418 struct pmc_owner *po; 2419 struct pmc_binding pb; 2420 2421 KASSERT(pm != NULL, ("[pmc,%d] null pmc", __LINE__)); 2422 2423 PMCDBG(PMC,OPS,1, "stop pmc=%p mode=%d ri=%d", pm, 2424 PMC_TO_MODE(pm), PMC_TO_ROWINDEX(pm)); 2425 2426 pm->pm_state = PMC_STATE_STOPPED; 2427 2428 /* 2429 * If the PMC is a virtual mode one, changing the state to 2430 * non-RUNNING is enough to ensure that the PMC never gets 2431 * scheduled. 2432 * 2433 * If this PMC is current running on a CPU, then it will 2434 * handled correctly at the time its target process is context 2435 * switched out. 2436 */ 2437 2438 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 2439 return 0; 2440 2441 /* 2442 * A system-mode PMC. Move to the CPU associated with 2443 * this PMC, and stop the hardware. We update the 2444 * 'initial count' so that a subsequent PMCSTART will 2445 * resume counting from the current hardware count. 2446 */ 2447 2448 pmc_save_cpu_binding(&pb); 2449 2450 cpu = PMC_TO_CPU(pm); 2451 2452 KASSERT(cpu >= 0 && cpu < mp_ncpus, 2453 ("[pmc,%d] illegal cpu=%d", __LINE__, cpu)); 2454 2455 if (pmc_cpu_is_disabled(cpu)) 2456 return ENXIO; 2457 2458 pmc_select_cpu(cpu); 2459 2460 ri = PMC_TO_ROWINDEX(pm); 2461 2462 critical_enter(); 2463 if ((error = md->pmd_stop_pmc(cpu, ri)) == 0) 2464 error = md->pmd_read_pmc(cpu, ri, &pm->pm_sc.pm_initial); 2465 critical_exit(); 2466 2467 pmc_restore_cpu_binding(&pb); 2468 2469 po = pm->pm_owner; 2470 2471 /* remove this owner from the global list of SS PMC owners */ 2472 if (PMC_TO_MODE(pm) == PMC_MODE_SS) { 2473 po->po_sscount--; 2474 if (po->po_sscount == 0) { 2475 atomic_subtract_rel_int(&pmc_ss_count, 1); 2476 LIST_REMOVE(po, po_ssnext); 2477 PMCDBG(PMC,OPS,2,"po=%p removed from global list", po); 2478 } 2479 } 2480 2481 return error; 2482 } 2483 2484 2485 #ifdef DEBUG 2486 static const char *pmc_op_to_name[] = { 2487 #undef __PMC_OP 2488 #define __PMC_OP(N, D) #N , 2489 __PMC_OPS() 2490 NULL 2491 }; 2492 #endif 2493 2494 /* 2495 * The syscall interface 2496 */ 2497 2498 #define PMC_GET_SX_XLOCK(...) do { \ 2499 sx_xlock(&pmc_sx); \ 2500 if (pmc_hook == NULL) { \ 2501 sx_xunlock(&pmc_sx); \ 2502 return __VA_ARGS__; \ 2503 } \ 2504 } while (0) 2505 2506 #define PMC_DOWNGRADE_SX() do { \ 2507 sx_downgrade(&pmc_sx); \ 2508 is_sx_downgraded = 1; \ 2509 } while (0) 2510 2511 static int 2512 pmc_syscall_handler(struct thread *td, void *syscall_args) 2513 { 2514 int error, is_sx_downgraded, op; 2515 struct pmc_syscall_args *c; 2516 void *arg; 2517 2518 PMC_GET_SX_XLOCK(ENOSYS); 2519 2520 DROP_GIANT(); 2521 2522 is_sx_downgraded = 0; 2523 2524 c = (struct pmc_syscall_args *) syscall_args; 2525 2526 op = c->pmop_code; 2527 arg = c->pmop_data; 2528 2529 PMCDBG(MOD,PMS,1, "syscall op=%d \"%s\" arg=%p", op, 2530 pmc_op_to_name[op], arg); 2531 2532 error = 0; 2533 atomic_add_int(&pmc_stats.pm_syscalls, 1); 2534 2535 switch(op) 2536 { 2537 2538 2539 /* 2540 * Configure a log file. 2541 * 2542 * XXX This OP will be reworked. 2543 */ 2544 2545 case PMC_OP_CONFIGURELOG: 2546 { 2547 struct proc *p; 2548 struct pmc *pm; 2549 struct pmc_owner *po; 2550 struct pmckern_map_in *km, *kmbase; 2551 struct pmc_op_configurelog cl; 2552 2553 sx_assert(&pmc_sx, SX_XLOCKED); 2554 2555 if ((error = copyin(arg, &cl, sizeof(cl))) != 0) 2556 break; 2557 2558 /* mark this process as owning a log file */ 2559 p = td->td_proc; 2560 if ((po = pmc_find_owner_descriptor(p)) == NULL) 2561 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) { 2562 error = ENOMEM; 2563 break; 2564 } 2565 2566 /* 2567 * If a valid fd was passed in, try to configure that, 2568 * otherwise if 'fd' was less than zero and there was 2569 * a log file configured, flush its buffers and 2570 * de-configure it. 2571 */ 2572 if (cl.pm_logfd >= 0) 2573 error = pmclog_configure_log(po, cl.pm_logfd); 2574 else if (po->po_flags & PMC_PO_OWNS_LOGFILE) { 2575 pmclog_process_closelog(po); 2576 error = pmclog_flush(po); 2577 if (error == 0) { 2578 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 2579 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 2580 pm->pm_state == PMC_STATE_RUNNING) 2581 pmc_stop(pm); 2582 error = pmclog_deconfigure_log(po); 2583 } 2584 } else 2585 error = EINVAL; 2586 2587 if (error) 2588 break; 2589 2590 /* 2591 * Log the current set of kernel modules. 2592 */ 2593 kmbase = linker_hwpmc_list_objects(); 2594 for (km = kmbase; km->pm_file != NULL; km++) { 2595 PMCDBG(LOG,REG,1,"%s %p", (char *) km->pm_file, 2596 (void *) km->pm_address); 2597 pmclog_process_map_in(po, (pid_t) -1, km->pm_address, 2598 km->pm_file); 2599 } 2600 FREE(kmbase, M_LINKER); 2601 } 2602 break; 2603 2604 2605 /* 2606 * Flush a log file. 2607 */ 2608 2609 case PMC_OP_FLUSHLOG: 2610 { 2611 struct pmc_owner *po; 2612 2613 sx_assert(&pmc_sx, SX_XLOCKED); 2614 2615 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 2616 error = EINVAL; 2617 break; 2618 } 2619 2620 error = pmclog_flush(po); 2621 } 2622 break; 2623 2624 /* 2625 * Retrieve hardware configuration. 2626 */ 2627 2628 case PMC_OP_GETCPUINFO: /* CPU information */ 2629 { 2630 struct pmc_op_getcpuinfo gci; 2631 2632 gci.pm_cputype = md->pmd_cputype; 2633 gci.pm_ncpu = mp_ncpus; 2634 gci.pm_npmc = md->pmd_npmc; 2635 gci.pm_nclass = md->pmd_nclass; 2636 bcopy(md->pmd_classes, &gci.pm_classes, 2637 sizeof(gci.pm_classes)); 2638 error = copyout(&gci, arg, sizeof(gci)); 2639 } 2640 break; 2641 2642 2643 /* 2644 * Get module statistics 2645 */ 2646 2647 case PMC_OP_GETDRIVERSTATS: 2648 { 2649 struct pmc_op_getdriverstats gms; 2650 2651 bcopy(&pmc_stats, &gms, sizeof(gms)); 2652 error = copyout(&gms, arg, sizeof(gms)); 2653 } 2654 break; 2655 2656 2657 /* 2658 * Retrieve module version number 2659 */ 2660 2661 case PMC_OP_GETMODULEVERSION: 2662 { 2663 uint32_t cv, modv; 2664 2665 /* retrieve the client's idea of the ABI version */ 2666 if ((error = copyin(arg, &cv, sizeof(uint32_t))) != 0) 2667 break; 2668 /* don't service clients newer than our driver */ 2669 modv = PMC_VERSION; 2670 if ((cv & 0xFFFF0000) > (modv & 0xFFFF0000)) { 2671 error = EPROGMISMATCH; 2672 break; 2673 } 2674 error = copyout(&modv, arg, sizeof(int)); 2675 } 2676 break; 2677 2678 2679 /* 2680 * Retrieve the state of all the PMCs on a given 2681 * CPU. 2682 */ 2683 2684 case PMC_OP_GETPMCINFO: 2685 { 2686 uint32_t cpu, n, npmc; 2687 size_t pmcinfo_size; 2688 struct pmc *pm; 2689 struct pmc_info *p, *pmcinfo; 2690 struct pmc_op_getpmcinfo *gpi; 2691 struct pmc_owner *po; 2692 struct pmc_binding pb; 2693 2694 PMC_DOWNGRADE_SX(); 2695 2696 gpi = (struct pmc_op_getpmcinfo *) arg; 2697 2698 if ((error = copyin(&gpi->pm_cpu, &cpu, sizeof(cpu))) != 0) 2699 break; 2700 2701 if (cpu >= (unsigned int) mp_ncpus) { 2702 error = EINVAL; 2703 break; 2704 } 2705 2706 if (pmc_cpu_is_disabled(cpu)) { 2707 error = ENXIO; 2708 break; 2709 } 2710 2711 /* switch to CPU 'cpu' */ 2712 pmc_save_cpu_binding(&pb); 2713 pmc_select_cpu(cpu); 2714 2715 npmc = md->pmd_npmc; 2716 2717 pmcinfo_size = npmc * sizeof(struct pmc_info); 2718 MALLOC(pmcinfo, struct pmc_info *, pmcinfo_size, M_PMC, 2719 M_WAITOK); 2720 2721 p = pmcinfo; 2722 2723 for (n = 0; n < md->pmd_npmc; n++, p++) { 2724 2725 if ((error = md->pmd_describe(cpu, n, p, &pm)) != 0) 2726 break; 2727 2728 if (PMC_ROW_DISP_IS_STANDALONE(n)) 2729 p->pm_rowdisp = PMC_DISP_STANDALONE; 2730 else if (PMC_ROW_DISP_IS_THREAD(n)) 2731 p->pm_rowdisp = PMC_DISP_THREAD; 2732 else 2733 p->pm_rowdisp = PMC_DISP_FREE; 2734 2735 p->pm_ownerpid = -1; 2736 2737 if (pm == NULL) /* no PMC associated */ 2738 continue; 2739 2740 po = pm->pm_owner; 2741 2742 KASSERT(po->po_owner != NULL, 2743 ("[pmc,%d] pmc_owner had a null proc pointer", 2744 __LINE__)); 2745 2746 p->pm_ownerpid = po->po_owner->p_pid; 2747 p->pm_mode = PMC_TO_MODE(pm); 2748 p->pm_event = pm->pm_event; 2749 p->pm_flags = pm->pm_flags; 2750 2751 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 2752 p->pm_reloadcount = 2753 pm->pm_sc.pm_reloadcount; 2754 } 2755 2756 pmc_restore_cpu_binding(&pb); 2757 2758 /* now copy out the PMC info collected */ 2759 if (error == 0) 2760 error = copyout(pmcinfo, &gpi->pm_pmcs, pmcinfo_size); 2761 2762 FREE(pmcinfo, M_PMC); 2763 } 2764 break; 2765 2766 2767 /* 2768 * Set the administrative state of a PMC. I.e. whether 2769 * the PMC is to be used or not. 2770 */ 2771 2772 case PMC_OP_PMCADMIN: 2773 { 2774 int cpu, ri; 2775 enum pmc_state request; 2776 struct pmc_cpu *pc; 2777 struct pmc_hw *phw; 2778 struct pmc_op_pmcadmin pma; 2779 struct pmc_binding pb; 2780 2781 sx_assert(&pmc_sx, SX_XLOCKED); 2782 2783 KASSERT(td == curthread, 2784 ("[pmc,%d] td != curthread", __LINE__)); 2785 2786 error = priv_check(td, PRIV_PMC_MANAGE); 2787 if (error) 2788 break; 2789 2790 if ((error = copyin(arg, &pma, sizeof(pma))) != 0) 2791 break; 2792 2793 cpu = pma.pm_cpu; 2794 2795 if (cpu < 0 || cpu >= mp_ncpus) { 2796 error = EINVAL; 2797 break; 2798 } 2799 2800 if (pmc_cpu_is_disabled(cpu)) { 2801 error = ENXIO; 2802 break; 2803 } 2804 2805 request = pma.pm_state; 2806 2807 if (request != PMC_STATE_DISABLED && 2808 request != PMC_STATE_FREE) { 2809 error = EINVAL; 2810 break; 2811 } 2812 2813 ri = pma.pm_pmc; /* pmc id == row index */ 2814 if (ri < 0 || ri >= (int) md->pmd_npmc) { 2815 error = EINVAL; 2816 break; 2817 } 2818 2819 /* 2820 * We can't disable a PMC with a row-index allocated 2821 * for process virtual PMCs. 2822 */ 2823 2824 if (PMC_ROW_DISP_IS_THREAD(ri) && 2825 request == PMC_STATE_DISABLED) { 2826 error = EBUSY; 2827 break; 2828 } 2829 2830 /* 2831 * otherwise, this PMC on this CPU is either free or 2832 * in system-wide mode. 2833 */ 2834 2835 pmc_save_cpu_binding(&pb); 2836 pmc_select_cpu(cpu); 2837 2838 pc = pmc_pcpu[cpu]; 2839 phw = pc->pc_hwpmcs[ri]; 2840 2841 /* 2842 * XXX do we need some kind of 'forced' disable? 2843 */ 2844 2845 if (phw->phw_pmc == NULL) { 2846 if (request == PMC_STATE_DISABLED && 2847 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED)) { 2848 phw->phw_state &= ~PMC_PHW_FLAG_IS_ENABLED; 2849 PMC_MARK_ROW_STANDALONE(ri); 2850 } else if (request == PMC_STATE_FREE && 2851 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0) { 2852 phw->phw_state |= PMC_PHW_FLAG_IS_ENABLED; 2853 PMC_UNMARK_ROW_STANDALONE(ri); 2854 } 2855 /* other cases are a no-op */ 2856 } else 2857 error = EBUSY; 2858 2859 pmc_restore_cpu_binding(&pb); 2860 } 2861 break; 2862 2863 2864 /* 2865 * Allocate a PMC. 2866 */ 2867 2868 case PMC_OP_PMCALLOCATE: 2869 { 2870 uint32_t caps; 2871 u_int cpu; 2872 int n; 2873 enum pmc_mode mode; 2874 struct pmc *pmc; 2875 struct pmc_hw *phw; 2876 struct pmc_op_pmcallocate pa; 2877 struct pmc_binding pb; 2878 2879 if ((error = copyin(arg, &pa, sizeof(pa))) != 0) 2880 break; 2881 2882 caps = pa.pm_caps; 2883 mode = pa.pm_mode; 2884 cpu = pa.pm_cpu; 2885 2886 if ((mode != PMC_MODE_SS && mode != PMC_MODE_SC && 2887 mode != PMC_MODE_TS && mode != PMC_MODE_TC) || 2888 (cpu != (u_int) PMC_CPU_ANY && cpu >= (u_int) mp_ncpus)) { 2889 error = EINVAL; 2890 break; 2891 } 2892 2893 /* 2894 * Virtual PMCs should only ask for a default CPU. 2895 * System mode PMCs need to specify a non-default CPU. 2896 */ 2897 2898 if ((PMC_IS_VIRTUAL_MODE(mode) && cpu != (u_int) PMC_CPU_ANY) || 2899 (PMC_IS_SYSTEM_MODE(mode) && cpu == (u_int) PMC_CPU_ANY)) { 2900 error = EINVAL; 2901 break; 2902 } 2903 2904 /* 2905 * Check that a disabled CPU is not being asked for. 2906 */ 2907 2908 if (PMC_IS_SYSTEM_MODE(mode) && pmc_cpu_is_disabled(cpu)) { 2909 error = ENXIO; 2910 break; 2911 } 2912 2913 /* 2914 * Refuse an allocation for a system-wide PMC if this 2915 * process has been jailed, or if this process lacks 2916 * super-user credentials and the sysctl tunable 2917 * 'security.bsd.unprivileged_syspmcs' is zero. 2918 */ 2919 2920 if (PMC_IS_SYSTEM_MODE(mode)) { 2921 if (jailed(curthread->td_ucred)) { 2922 error = EPERM; 2923 break; 2924 } 2925 if (!pmc_unprivileged_syspmcs) { 2926 error = priv_check(curthread, 2927 PRIV_PMC_SYSTEM); 2928 if (error) 2929 break; 2930 } 2931 } 2932 2933 if (error) 2934 break; 2935 2936 /* 2937 * Look for valid values for 'pm_flags' 2938 */ 2939 2940 if ((pa.pm_flags & ~(PMC_F_DESCENDANTS | PMC_F_LOG_PROCCSW | 2941 PMC_F_LOG_PROCEXIT)) != 0) { 2942 error = EINVAL; 2943 break; 2944 } 2945 2946 /* process logging options are not allowed for system PMCs */ 2947 if (PMC_IS_SYSTEM_MODE(mode) && (pa.pm_flags & 2948 (PMC_F_LOG_PROCCSW | PMC_F_LOG_PROCEXIT))) { 2949 error = EINVAL; 2950 break; 2951 } 2952 2953 /* 2954 * All sampling mode PMCs need to be able to interrupt the 2955 * CPU. 2956 */ 2957 if (PMC_IS_SAMPLING_MODE(mode)) 2958 caps |= PMC_CAP_INTERRUPT; 2959 2960 /* A valid class specifier should have been passed in. */ 2961 for (n = 0; n < md->pmd_nclass; n++) 2962 if (md->pmd_classes[n].pm_class == pa.pm_class) 2963 break; 2964 if (n == md->pmd_nclass) { 2965 error = EINVAL; 2966 break; 2967 } 2968 2969 /* The requested PMC capabilities should be feasible. */ 2970 if ((md->pmd_classes[n].pm_caps & caps) != caps) { 2971 error = EOPNOTSUPP; 2972 break; 2973 } 2974 2975 PMCDBG(PMC,ALL,2, "event=%d caps=0x%x mode=%d cpu=%d", 2976 pa.pm_ev, caps, mode, cpu); 2977 2978 pmc = pmc_allocate_pmc_descriptor(); 2979 pmc->pm_id = PMC_ID_MAKE_ID(cpu,pa.pm_mode,pa.pm_class, 2980 PMC_ID_INVALID); 2981 pmc->pm_event = pa.pm_ev; 2982 pmc->pm_state = PMC_STATE_FREE; 2983 pmc->pm_caps = caps; 2984 pmc->pm_flags = pa.pm_flags; 2985 2986 /* switch thread to CPU 'cpu' */ 2987 pmc_save_cpu_binding(&pb); 2988 2989 #define PMC_IS_SHAREABLE_PMC(cpu, n) \ 2990 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_state & \ 2991 PMC_PHW_FLAG_IS_SHAREABLE) 2992 #define PMC_IS_UNALLOCATED(cpu, n) \ 2993 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_pmc == NULL) 2994 2995 if (PMC_IS_SYSTEM_MODE(mode)) { 2996 pmc_select_cpu(cpu); 2997 for (n = 0; n < (int) md->pmd_npmc; n++) 2998 if (pmc_can_allocate_row(n, mode) == 0 && 2999 pmc_can_allocate_rowindex( 3000 curthread->td_proc, n, cpu) == 0 && 3001 (PMC_IS_UNALLOCATED(cpu, n) || 3002 PMC_IS_SHAREABLE_PMC(cpu, n)) && 3003 md->pmd_allocate_pmc(cpu, n, pmc, 3004 &pa) == 0) 3005 break; 3006 } else { 3007 /* Process virtual mode */ 3008 for (n = 0; n < (int) md->pmd_npmc; n++) { 3009 if (pmc_can_allocate_row(n, mode) == 0 && 3010 pmc_can_allocate_rowindex( 3011 curthread->td_proc, n, 3012 PMC_CPU_ANY) == 0 && 3013 md->pmd_allocate_pmc(curthread->td_oncpu, 3014 n, pmc, &pa) == 0) 3015 break; 3016 } 3017 } 3018 3019 #undef PMC_IS_UNALLOCATED 3020 #undef PMC_IS_SHAREABLE_PMC 3021 3022 pmc_restore_cpu_binding(&pb); 3023 3024 if (n == (int) md->pmd_npmc) { 3025 pmc_destroy_pmc_descriptor(pmc); 3026 FREE(pmc, M_PMC); 3027 pmc = NULL; 3028 error = EINVAL; 3029 break; 3030 } 3031 3032 /* Fill in the correct value in the ID field */ 3033 pmc->pm_id = PMC_ID_MAKE_ID(cpu,mode,pa.pm_class,n); 3034 3035 PMCDBG(PMC,ALL,2, "ev=%d class=%d mode=%d n=%d -> pmcid=%x", 3036 pmc->pm_event, pa.pm_class, mode, n, pmc->pm_id); 3037 3038 /* Process mode PMCs with logging enabled need log files */ 3039 if (pmc->pm_flags & (PMC_F_LOG_PROCEXIT | PMC_F_LOG_PROCCSW)) 3040 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3041 3042 /* All system mode sampling PMCs require a log file */ 3043 if (PMC_IS_SAMPLING_MODE(mode) && PMC_IS_SYSTEM_MODE(mode)) 3044 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3045 3046 /* 3047 * Configure global pmc's immediately 3048 */ 3049 3050 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pmc))) { 3051 3052 pmc_save_cpu_binding(&pb); 3053 pmc_select_cpu(cpu); 3054 3055 phw = pmc_pcpu[cpu]->pc_hwpmcs[n]; 3056 3057 if ((phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0 || 3058 (error = md->pmd_config_pmc(cpu, n, pmc)) != 0) { 3059 (void) md->pmd_release_pmc(cpu, n, pmc); 3060 pmc_destroy_pmc_descriptor(pmc); 3061 FREE(pmc, M_PMC); 3062 pmc = NULL; 3063 pmc_restore_cpu_binding(&pb); 3064 error = EPERM; 3065 break; 3066 } 3067 3068 pmc_restore_cpu_binding(&pb); 3069 } 3070 3071 pmc->pm_state = PMC_STATE_ALLOCATED; 3072 3073 /* 3074 * mark row disposition 3075 */ 3076 3077 if (PMC_IS_SYSTEM_MODE(mode)) 3078 PMC_MARK_ROW_STANDALONE(n); 3079 else 3080 PMC_MARK_ROW_THREAD(n); 3081 3082 /* 3083 * Register this PMC with the current thread as its owner. 3084 */ 3085 3086 if ((error = 3087 pmc_register_owner(curthread->td_proc, pmc)) != 0) { 3088 pmc_release_pmc_descriptor(pmc); 3089 FREE(pmc, M_PMC); 3090 pmc = NULL; 3091 break; 3092 } 3093 3094 /* 3095 * Return the allocated index. 3096 */ 3097 3098 pa.pm_pmcid = pmc->pm_id; 3099 3100 error = copyout(&pa, arg, sizeof(pa)); 3101 } 3102 break; 3103 3104 3105 /* 3106 * Attach a PMC to a process. 3107 */ 3108 3109 case PMC_OP_PMCATTACH: 3110 { 3111 struct pmc *pm; 3112 struct proc *p; 3113 struct pmc_op_pmcattach a; 3114 3115 sx_assert(&pmc_sx, SX_XLOCKED); 3116 3117 if ((error = copyin(arg, &a, sizeof(a))) != 0) 3118 break; 3119 3120 if (a.pm_pid < 0) { 3121 error = EINVAL; 3122 break; 3123 } else if (a.pm_pid == 0) 3124 a.pm_pid = td->td_proc->p_pid; 3125 3126 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 3127 break; 3128 3129 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) { 3130 error = EINVAL; 3131 break; 3132 } 3133 3134 /* PMCs may be (re)attached only when allocated or stopped */ 3135 if (pm->pm_state == PMC_STATE_RUNNING) { 3136 error = EBUSY; 3137 break; 3138 } else if (pm->pm_state != PMC_STATE_ALLOCATED && 3139 pm->pm_state != PMC_STATE_STOPPED) { 3140 error = EINVAL; 3141 break; 3142 } 3143 3144 /* lookup pid */ 3145 if ((p = pfind(a.pm_pid)) == NULL) { 3146 error = ESRCH; 3147 break; 3148 } 3149 3150 /* 3151 * Ignore processes that are working on exiting. 3152 */ 3153 if (p->p_flag & P_WEXIT) { 3154 error = ESRCH; 3155 PROC_UNLOCK(p); /* pfind() returns a locked process */ 3156 break; 3157 } 3158 3159 /* 3160 * we are allowed to attach a PMC to a process if 3161 * we can debug it. 3162 */ 3163 error = p_candebug(curthread, p); 3164 3165 PROC_UNLOCK(p); 3166 3167 if (error == 0) 3168 error = pmc_attach_process(p, pm); 3169 } 3170 break; 3171 3172 3173 /* 3174 * Detach an attached PMC from a process. 3175 */ 3176 3177 case PMC_OP_PMCDETACH: 3178 { 3179 struct pmc *pm; 3180 struct proc *p; 3181 struct pmc_op_pmcattach a; 3182 3183 if ((error = copyin(arg, &a, sizeof(a))) != 0) 3184 break; 3185 3186 if (a.pm_pid < 0) { 3187 error = EINVAL; 3188 break; 3189 } else if (a.pm_pid == 0) 3190 a.pm_pid = td->td_proc->p_pid; 3191 3192 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 3193 break; 3194 3195 if ((p = pfind(a.pm_pid)) == NULL) { 3196 error = ESRCH; 3197 break; 3198 } 3199 3200 /* 3201 * Treat processes that are in the process of exiting 3202 * as if they were not present. 3203 */ 3204 3205 if (p->p_flag & P_WEXIT) 3206 error = ESRCH; 3207 3208 PROC_UNLOCK(p); /* pfind() returns a locked process */ 3209 3210 if (error == 0) 3211 error = pmc_detach_process(p, pm); 3212 } 3213 break; 3214 3215 3216 /* 3217 * Retrieve the MSR number associated with the counter 3218 * 'pmc_id'. This allows processes to directly use RDPMC 3219 * instructions to read their PMCs, without the overhead of a 3220 * system call. 3221 */ 3222 3223 case PMC_OP_PMCGETMSR: 3224 { 3225 int ri; 3226 struct pmc *pm; 3227 struct pmc_target *pt; 3228 struct pmc_op_getmsr gm; 3229 3230 PMC_DOWNGRADE_SX(); 3231 3232 /* CPU has no 'GETMSR' support */ 3233 if (md->pmd_get_msr == NULL) { 3234 error = ENOSYS; 3235 break; 3236 } 3237 3238 if ((error = copyin(arg, &gm, sizeof(gm))) != 0) 3239 break; 3240 3241 if ((error = pmc_find_pmc(gm.pm_pmcid, &pm)) != 0) 3242 break; 3243 3244 /* 3245 * The allocated PMC has to be a process virtual PMC, 3246 * i.e., of type MODE_T[CS]. Global PMCs can only be 3247 * read using the PMCREAD operation since they may be 3248 * allocated on a different CPU than the one we could 3249 * be running on at the time of the RDPMC instruction. 3250 * 3251 * The GETMSR operation is not allowed for PMCs that 3252 * are inherited across processes. 3253 */ 3254 3255 if (!PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)) || 3256 (pm->pm_flags & PMC_F_DESCENDANTS)) { 3257 error = EINVAL; 3258 break; 3259 } 3260 3261 /* 3262 * It only makes sense to use a RDPMC (or its 3263 * equivalent instruction on non-x86 architectures) on 3264 * a process that has allocated and attached a PMC to 3265 * itself. Conversely the PMC is only allowed to have 3266 * one process attached to it -- its owner. 3267 */ 3268 3269 if ((pt = LIST_FIRST(&pm->pm_targets)) == NULL || 3270 LIST_NEXT(pt, pt_next) != NULL || 3271 pt->pt_process->pp_proc != pm->pm_owner->po_owner) { 3272 error = EINVAL; 3273 break; 3274 } 3275 3276 ri = PMC_TO_ROWINDEX(pm); 3277 3278 if ((error = (*md->pmd_get_msr)(ri, &gm.pm_msr)) < 0) 3279 break; 3280 3281 if ((error = copyout(&gm, arg, sizeof(gm))) < 0) 3282 break; 3283 3284 /* 3285 * Mark our process as using MSRs. Update machine 3286 * state using a forced context switch. 3287 */ 3288 3289 pt->pt_process->pp_flags |= PMC_PP_ENABLE_MSR_ACCESS; 3290 pmc_force_context_switch(); 3291 3292 } 3293 break; 3294 3295 /* 3296 * Release an allocated PMC 3297 */ 3298 3299 case PMC_OP_PMCRELEASE: 3300 { 3301 pmc_id_t pmcid; 3302 struct pmc *pm; 3303 struct pmc_owner *po; 3304 struct pmc_op_simple sp; 3305 3306 /* 3307 * Find PMC pointer for the named PMC. 3308 * 3309 * Use pmc_release_pmc_descriptor() to switch off the 3310 * PMC, remove all its target threads, and remove the 3311 * PMC from its owner's list. 3312 * 3313 * Remove the owner record if this is the last PMC 3314 * owned. 3315 * 3316 * Free up space. 3317 */ 3318 3319 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3320 break; 3321 3322 pmcid = sp.pm_pmcid; 3323 3324 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3325 break; 3326 3327 po = pm->pm_owner; 3328 pmc_release_pmc_descriptor(pm); 3329 pmc_maybe_remove_owner(po); 3330 3331 FREE(pm, M_PMC); 3332 } 3333 break; 3334 3335 3336 /* 3337 * Read and/or write a PMC. 3338 */ 3339 3340 case PMC_OP_PMCRW: 3341 { 3342 uint32_t cpu, ri; 3343 struct pmc *pm; 3344 struct pmc_op_pmcrw *pprw; 3345 struct pmc_op_pmcrw prw; 3346 struct pmc_binding pb; 3347 pmc_value_t oldvalue; 3348 3349 PMC_DOWNGRADE_SX(); 3350 3351 if ((error = copyin(arg, &prw, sizeof(prw))) != 0) 3352 break; 3353 3354 ri = 0; 3355 PMCDBG(PMC,OPS,1, "rw id=%d flags=0x%x", prw.pm_pmcid, 3356 prw.pm_flags); 3357 3358 /* must have at least one flag set */ 3359 if ((prw.pm_flags & (PMC_F_OLDVALUE|PMC_F_NEWVALUE)) == 0) { 3360 error = EINVAL; 3361 break; 3362 } 3363 3364 /* locate pmc descriptor */ 3365 if ((error = pmc_find_pmc(prw.pm_pmcid, &pm)) != 0) 3366 break; 3367 3368 /* Can't read a PMC that hasn't been started. */ 3369 if (pm->pm_state != PMC_STATE_ALLOCATED && 3370 pm->pm_state != PMC_STATE_STOPPED && 3371 pm->pm_state != PMC_STATE_RUNNING) { 3372 error = EINVAL; 3373 break; 3374 } 3375 3376 /* writing a new value is allowed only for 'STOPPED' pmcs */ 3377 if (pm->pm_state == PMC_STATE_RUNNING && 3378 (prw.pm_flags & PMC_F_NEWVALUE)) { 3379 error = EBUSY; 3380 break; 3381 } 3382 3383 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) { 3384 3385 /* 3386 * If this PMC is attached to its owner (i.e., 3387 * the process requesting this operation) and 3388 * is running, then attempt to get an 3389 * upto-date reading from hardware for a READ. 3390 * Writes are only allowed when the PMC is 3391 * stopped, so only update the saved value 3392 * field. 3393 * 3394 * If the PMC is not running, or is not 3395 * attached to its owner, read/write to the 3396 * savedvalue field. 3397 */ 3398 3399 ri = PMC_TO_ROWINDEX(pm); 3400 3401 mtx_pool_lock_spin(pmc_mtxpool, pm); 3402 cpu = curthread->td_oncpu; 3403 3404 if (prw.pm_flags & PMC_F_OLDVALUE) { 3405 if ((pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) && 3406 (pm->pm_state == PMC_STATE_RUNNING)) 3407 error = (*md->pmd_read_pmc)(cpu, ri, 3408 &oldvalue); 3409 else 3410 oldvalue = pm->pm_gv.pm_savedvalue; 3411 } 3412 if (prw.pm_flags & PMC_F_NEWVALUE) 3413 pm->pm_gv.pm_savedvalue = prw.pm_value; 3414 3415 mtx_pool_unlock_spin(pmc_mtxpool, pm); 3416 3417 } else { /* System mode PMCs */ 3418 cpu = PMC_TO_CPU(pm); 3419 ri = PMC_TO_ROWINDEX(pm); 3420 3421 if (pmc_cpu_is_disabled(cpu)) { 3422 error = ENXIO; 3423 break; 3424 } 3425 3426 /* move this thread to CPU 'cpu' */ 3427 pmc_save_cpu_binding(&pb); 3428 pmc_select_cpu(cpu); 3429 3430 critical_enter(); 3431 /* save old value */ 3432 if (prw.pm_flags & PMC_F_OLDVALUE) 3433 if ((error = (*md->pmd_read_pmc)(cpu, ri, 3434 &oldvalue))) 3435 goto error; 3436 /* write out new value */ 3437 if (prw.pm_flags & PMC_F_NEWVALUE) 3438 error = (*md->pmd_write_pmc)(cpu, ri, 3439 prw.pm_value); 3440 error: 3441 critical_exit(); 3442 pmc_restore_cpu_binding(&pb); 3443 if (error) 3444 break; 3445 } 3446 3447 pprw = (struct pmc_op_pmcrw *) arg; 3448 3449 #ifdef DEBUG 3450 if (prw.pm_flags & PMC_F_NEWVALUE) 3451 PMCDBG(PMC,OPS,2, "rw id=%d new %jx -> old %jx", 3452 ri, prw.pm_value, oldvalue); 3453 else if (prw.pm_flags & PMC_F_OLDVALUE) 3454 PMCDBG(PMC,OPS,2, "rw id=%d -> old %jx", ri, oldvalue); 3455 #endif 3456 3457 /* return old value if requested */ 3458 if (prw.pm_flags & PMC_F_OLDVALUE) 3459 if ((error = copyout(&oldvalue, &pprw->pm_value, 3460 sizeof(prw.pm_value)))) 3461 break; 3462 3463 } 3464 break; 3465 3466 3467 /* 3468 * Set the sampling rate for a sampling mode PMC and the 3469 * initial count for a counting mode PMC. 3470 */ 3471 3472 case PMC_OP_PMCSETCOUNT: 3473 { 3474 struct pmc *pm; 3475 struct pmc_op_pmcsetcount sc; 3476 3477 PMC_DOWNGRADE_SX(); 3478 3479 if ((error = copyin(arg, &sc, sizeof(sc))) != 0) 3480 break; 3481 3482 if ((error = pmc_find_pmc(sc.pm_pmcid, &pm)) != 0) 3483 break; 3484 3485 if (pm->pm_state == PMC_STATE_RUNNING) { 3486 error = EBUSY; 3487 break; 3488 } 3489 3490 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 3491 pm->pm_sc.pm_reloadcount = sc.pm_count; 3492 else 3493 pm->pm_sc.pm_initial = sc.pm_count; 3494 } 3495 break; 3496 3497 3498 /* 3499 * Start a PMC. 3500 */ 3501 3502 case PMC_OP_PMCSTART: 3503 { 3504 pmc_id_t pmcid; 3505 struct pmc *pm; 3506 struct pmc_op_simple sp; 3507 3508 sx_assert(&pmc_sx, SX_XLOCKED); 3509 3510 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3511 break; 3512 3513 pmcid = sp.pm_pmcid; 3514 3515 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3516 break; 3517 3518 KASSERT(pmcid == pm->pm_id, 3519 ("[pmc,%d] pmcid %x != id %x", __LINE__, 3520 pm->pm_id, pmcid)); 3521 3522 if (pm->pm_state == PMC_STATE_RUNNING) /* already running */ 3523 break; 3524 else if (pm->pm_state != PMC_STATE_STOPPED && 3525 pm->pm_state != PMC_STATE_ALLOCATED) { 3526 error = EINVAL; 3527 break; 3528 } 3529 3530 error = pmc_start(pm); 3531 } 3532 break; 3533 3534 3535 /* 3536 * Stop a PMC. 3537 */ 3538 3539 case PMC_OP_PMCSTOP: 3540 { 3541 pmc_id_t pmcid; 3542 struct pmc *pm; 3543 struct pmc_op_simple sp; 3544 3545 PMC_DOWNGRADE_SX(); 3546 3547 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3548 break; 3549 3550 pmcid = sp.pm_pmcid; 3551 3552 /* 3553 * Mark the PMC as inactive and invoke the MD stop 3554 * routines if needed. 3555 */ 3556 3557 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3558 break; 3559 3560 KASSERT(pmcid == pm->pm_id, 3561 ("[pmc,%d] pmc id %x != pmcid %x", __LINE__, 3562 pm->pm_id, pmcid)); 3563 3564 if (pm->pm_state == PMC_STATE_STOPPED) /* already stopped */ 3565 break; 3566 else if (pm->pm_state != PMC_STATE_RUNNING) { 3567 error = EINVAL; 3568 break; 3569 } 3570 3571 error = pmc_stop(pm); 3572 } 3573 break; 3574 3575 3576 /* 3577 * Write a user supplied value to the log file. 3578 */ 3579 3580 case PMC_OP_WRITELOG: 3581 { 3582 struct pmc_op_writelog wl; 3583 struct pmc_owner *po; 3584 3585 PMC_DOWNGRADE_SX(); 3586 3587 if ((error = copyin(arg, &wl, sizeof(wl))) != 0) 3588 break; 3589 3590 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 3591 error = EINVAL; 3592 break; 3593 } 3594 3595 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) { 3596 error = EINVAL; 3597 break; 3598 } 3599 3600 error = pmclog_process_userlog(po, &wl); 3601 } 3602 break; 3603 3604 3605 default: 3606 error = EINVAL; 3607 break; 3608 } 3609 3610 if (is_sx_downgraded) 3611 sx_sunlock(&pmc_sx); 3612 else 3613 sx_xunlock(&pmc_sx); 3614 3615 if (error) 3616 atomic_add_int(&pmc_stats.pm_syscall_errors, 1); 3617 3618 PICKUP_GIANT(); 3619 3620 return error; 3621 } 3622 3623 /* 3624 * Helper functions 3625 */ 3626 3627 3628 /* 3629 * Interrupt processing. 3630 * 3631 * Find a free slot in the per-cpu array of PC samples and write the 3632 * current (PMC,PID,PC) triple to it. If an event was successfully 3633 * added, a bit is set in mask 'pmc_cpumask' denoting that the 3634 * DO_SAMPLES hook needs to be invoked from the clock handler. 3635 * 3636 * This function is meant to be called from an NMI handler. It cannot 3637 * use any of the locking primitives supplied by the OS. 3638 */ 3639 3640 int 3641 pmc_process_interrupt(int cpu, struct pmc *pm, uintfptr_t pc, int usermode) 3642 { 3643 int error, ri; 3644 struct thread *td; 3645 struct pmc_sample *ps; 3646 struct pmc_samplebuffer *psb; 3647 3648 error = 0; 3649 ri = PMC_TO_ROWINDEX(pm); 3650 3651 psb = pmc_pcpu[cpu]->pc_sb; 3652 3653 ps = psb->ps_write; 3654 if (ps->ps_pc) { /* in use, reader hasn't caught up */ 3655 pm->pm_stalled = 1; 3656 atomic_add_int(&pmc_stats.pm_intr_bufferfull, 1); 3657 PMCDBG(SAM,INT,1,"(spc) cpu=%d pm=%p pc=%jx um=%d wr=%d rd=%d", 3658 cpu, pm, (uint64_t) pc, usermode, 3659 (int) (psb->ps_write - psb->ps_samples), 3660 (int) (psb->ps_read - psb->ps_samples)); 3661 error = ENOMEM; 3662 goto done; 3663 } 3664 3665 /* fill in entry */ 3666 PMCDBG(SAM,INT,1,"cpu=%d pm=%p pc=%jx um=%d wr=%d rd=%d", cpu, pm, 3667 (uint64_t) pc, usermode, 3668 (int) (psb->ps_write - psb->ps_samples), 3669 (int) (psb->ps_read - psb->ps_samples)); 3670 3671 atomic_add_rel_32(&pm->pm_runcount, 1); /* hold onto PMC */ 3672 ps->ps_pmc = pm; 3673 if ((td = curthread) && td->td_proc) 3674 ps->ps_pid = td->td_proc->p_pid; 3675 else 3676 ps->ps_pid = -1; 3677 ps->ps_usermode = usermode; 3678 ps->ps_pc = pc; /* mark entry as in use */ 3679 3680 /* increment write pointer, modulo ring buffer size */ 3681 ps++; 3682 if (ps == psb->ps_fence) 3683 psb->ps_write = psb->ps_samples; 3684 else 3685 psb->ps_write = ps; 3686 3687 done: 3688 /* mark CPU as needing processing */ 3689 atomic_set_rel_int(&pmc_cpumask, (1 << cpu)); 3690 3691 return error; 3692 } 3693 3694 3695 /* 3696 * Process saved PC samples. 3697 */ 3698 3699 static void 3700 pmc_process_samples(int cpu) 3701 { 3702 int n, ri; 3703 struct pmc *pm; 3704 struct thread *td; 3705 struct pmc_owner *po; 3706 struct pmc_sample *ps; 3707 struct pmc_samplebuffer *psb; 3708 3709 KASSERT(PCPU_GET(cpuid) == cpu, 3710 ("[pmc,%d] not on the correct CPU pcpu=%d cpu=%d", __LINE__, 3711 PCPU_GET(cpuid), cpu)); 3712 3713 psb = pmc_pcpu[cpu]->pc_sb; 3714 3715 for (n = 0; n < pmc_nsamples; n++) { /* bound on #iterations */ 3716 3717 ps = psb->ps_read; 3718 if (ps->ps_pc == (uintfptr_t) 0) /* no data */ 3719 break; 3720 3721 pm = ps->ps_pmc; 3722 po = pm->pm_owner; 3723 3724 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 3725 ("[pmc,%d] pmc=%p non-sampling mode=%d", __LINE__, 3726 pm, PMC_TO_MODE(pm))); 3727 3728 /* Ignore PMCs that have been switched off */ 3729 if (pm->pm_state != PMC_STATE_RUNNING) 3730 goto entrydone; 3731 3732 PMCDBG(SAM,OPS,1,"cpu=%d pm=%p pc=%jx um=%d wr=%d rd=%d", cpu, 3733 pm, (uint64_t) ps->ps_pc, ps->ps_usermode, 3734 (int) (psb->ps_write - psb->ps_samples), 3735 (int) (psb->ps_read - psb->ps_samples)); 3736 3737 /* 3738 * If this is a process-mode PMC that is attached to 3739 * its owner, and if the PC is in user mode, update 3740 * profiling statistics like timer-based profiling 3741 * would have done. 3742 */ 3743 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) { 3744 if (ps->ps_usermode) { 3745 td = FIRST_THREAD_IN_PROC(po->po_owner); 3746 addupc_intr(td, ps->ps_pc, 1); 3747 } 3748 goto entrydone; 3749 } 3750 3751 /* 3752 * Otherwise, this is either a sampling mode PMC that 3753 * is attached to a different process than its owner, 3754 * or a system-wide sampling PMC. Dispatch a log 3755 * entry to the PMC's owner process. 3756 */ 3757 3758 pmclog_process_pcsample(pm, ps); 3759 3760 entrydone: 3761 ps->ps_pc = (uintfptr_t) 0; /* mark entry as free */ 3762 atomic_subtract_rel_32(&pm->pm_runcount, 1); 3763 3764 /* increment read pointer, modulo sample size */ 3765 if (++ps == psb->ps_fence) 3766 psb->ps_read = psb->ps_samples; 3767 else 3768 psb->ps_read = ps; 3769 } 3770 3771 atomic_add_int(&pmc_stats.pm_log_sweeps, 1); 3772 3773 /* Do not re-enable stalled PMCs if we failed to process any samples */ 3774 if (n == 0) 3775 return; 3776 3777 /* 3778 * Restart any stalled sampling PMCs on this CPU. 3779 * 3780 * If the NMI handler sets the pm_stalled field of a PMC after 3781 * the check below, we'll end up processing the stalled PMC at 3782 * the next hardclock tick. 3783 */ 3784 for (n = 0; n < md->pmd_npmc; n++) { 3785 (void) (*md->pmd_get_config)(cpu,n,&pm); 3786 if (pm == NULL || /* !cfg'ed */ 3787 pm->pm_state != PMC_STATE_RUNNING || /* !active */ 3788 !PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) || /* !sampling */ 3789 pm->pm_stalled == 0) /* !stalled */ 3790 continue; 3791 3792 pm->pm_stalled = 0; 3793 ri = PMC_TO_ROWINDEX(pm); 3794 (*md->pmd_start_pmc)(cpu, ri); 3795 } 3796 } 3797 3798 /* 3799 * Event handlers. 3800 */ 3801 3802 /* 3803 * Handle a process exit. 3804 * 3805 * Remove this process from all hash tables. If this process 3806 * owned any PMCs, turn off those PMCs and deallocate them, 3807 * removing any associations with target processes. 3808 * 3809 * This function will be called by the last 'thread' of a 3810 * process. 3811 * 3812 * XXX This eventhandler gets called early in the exit process. 3813 * Consider using a 'hook' invocation from thread_exit() or equivalent 3814 * spot. Another negative is that kse_exit doesn't seem to call 3815 * exit1() [??]. 3816 * 3817 */ 3818 3819 static void 3820 pmc_process_exit(void *arg __unused, struct proc *p) 3821 { 3822 int is_using_hwpmcs; 3823 int cpu; 3824 unsigned int ri; 3825 struct pmc *pm; 3826 struct pmc_process *pp; 3827 struct pmc_owner *po; 3828 pmc_value_t newvalue, tmp; 3829 3830 PROC_LOCK(p); 3831 is_using_hwpmcs = p->p_flag & P_HWPMC; 3832 PROC_UNLOCK(p); 3833 3834 /* 3835 * Log a sysexit event to all SS PMC owners. 3836 */ 3837 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 3838 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 3839 pmclog_process_sysexit(po, p->p_pid); 3840 3841 if (!is_using_hwpmcs) 3842 return; 3843 3844 PMC_GET_SX_XLOCK(); 3845 PMCDBG(PRC,EXT,1,"process-exit proc=%p (%d, %s)", p, p->p_pid, 3846 p->p_comm); 3847 3848 /* 3849 * Since this code is invoked by the last thread in an exiting 3850 * process, we would have context switched IN at some prior 3851 * point. However, with PREEMPTION, kernel mode context 3852 * switches may happen any time, so we want to disable a 3853 * context switch OUT till we get any PMCs targetting this 3854 * process off the hardware. 3855 * 3856 * We also need to atomically remove this process' 3857 * entry from our target process hash table, using 3858 * PMC_FLAG_REMOVE. 3859 */ 3860 PMCDBG(PRC,EXT,1, "process-exit proc=%p (%d, %s)", p, p->p_pid, 3861 p->p_comm); 3862 3863 critical_enter(); /* no preemption */ 3864 3865 cpu = curthread->td_oncpu; 3866 3867 if ((pp = pmc_find_process_descriptor(p, 3868 PMC_FLAG_REMOVE)) != NULL) { 3869 3870 PMCDBG(PRC,EXT,2, 3871 "process-exit proc=%p pmc-process=%p", p, pp); 3872 3873 /* 3874 * The exiting process could the target of 3875 * some PMCs which will be running on 3876 * currently executing CPU. 3877 * 3878 * We need to turn these PMCs off like we 3879 * would do at context switch OUT time. 3880 */ 3881 for (ri = 0; ri < md->pmd_npmc; ri++) { 3882 3883 /* 3884 * Pick up the pmc pointer from hardware 3885 * state similar to the CSW_OUT code. 3886 */ 3887 pm = NULL; 3888 (void) (*md->pmd_get_config)(cpu, ri, &pm); 3889 3890 PMCDBG(PRC,EXT,2, "ri=%d pm=%p", ri, pm); 3891 3892 if (pm == NULL || 3893 !PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 3894 continue; 3895 3896 PMCDBG(PRC,EXT,2, "ppmcs[%d]=%p pm=%p " 3897 "state=%d", ri, pp->pp_pmcs[ri].pp_pmc, 3898 pm, pm->pm_state); 3899 3900 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 3901 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 3902 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 3903 3904 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 3905 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", 3906 __LINE__, pm, ri, pp->pp_pmcs[ri].pp_pmc)); 3907 3908 (void) md->pmd_stop_pmc(cpu, ri); 3909 3910 KASSERT(pm->pm_runcount > 0, 3911 ("[pmc,%d] bad runcount ri %d rc %d", 3912 __LINE__, ri, pm->pm_runcount)); 3913 3914 /* Stop hardware only if it is actually running */ 3915 if (pm->pm_state == PMC_STATE_RUNNING && 3916 pm->pm_stalled == 0) { 3917 md->pmd_read_pmc(cpu, ri, &newvalue); 3918 tmp = newvalue - 3919 PMC_PCPU_SAVED(cpu,ri); 3920 3921 mtx_pool_lock_spin(pmc_mtxpool, pm); 3922 pm->pm_gv.pm_savedvalue += tmp; 3923 pp->pp_pmcs[ri].pp_pmcval += tmp; 3924 mtx_pool_unlock_spin(pmc_mtxpool, pm); 3925 } 3926 3927 atomic_subtract_rel_32(&pm->pm_runcount,1); 3928 3929 KASSERT((int) pm->pm_runcount >= 0, 3930 ("[pmc,%d] runcount is %d", __LINE__, ri)); 3931 3932 (void) md->pmd_config_pmc(cpu, ri, NULL); 3933 } 3934 3935 /* 3936 * Inform the MD layer of this pseudo "context switch 3937 * out" 3938 */ 3939 (void) md->pmd_switch_out(pmc_pcpu[cpu], pp); 3940 3941 critical_exit(); /* ok to be pre-empted now */ 3942 3943 /* 3944 * Unlink this process from the PMCs that are 3945 * targetting it. This will send a signal to 3946 * all PMC owner's whose PMCs are orphaned. 3947 * 3948 * Log PMC value at exit time if requested. 3949 */ 3950 for (ri = 0; ri < md->pmd_npmc; ri++) 3951 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 3952 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 3953 PMC_IS_COUNTING_MODE(PMC_TO_MODE(pm))) 3954 pmclog_process_procexit(pm, pp); 3955 pmc_unlink_target_process(pm, pp); 3956 } 3957 FREE(pp, M_PMC); 3958 3959 } else 3960 critical_exit(); /* pp == NULL */ 3961 3962 3963 /* 3964 * If the process owned PMCs, free them up and free up 3965 * memory. 3966 */ 3967 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 3968 pmc_remove_owner(po); 3969 pmc_destroy_owner_descriptor(po); 3970 } 3971 3972 sx_xunlock(&pmc_sx); 3973 } 3974 3975 /* 3976 * Handle a process fork. 3977 * 3978 * If the parent process 'p1' is under HWPMC monitoring, then copy 3979 * over any attached PMCs that have 'do_descendants' semantics. 3980 */ 3981 3982 static void 3983 pmc_process_fork(void *arg __unused, struct proc *p1, struct proc *newproc, 3984 int flags) 3985 { 3986 int is_using_hwpmcs; 3987 unsigned int ri; 3988 uint32_t do_descendants; 3989 struct pmc *pm; 3990 struct pmc_owner *po; 3991 struct pmc_process *ppnew, *ppold; 3992 3993 (void) flags; /* unused parameter */ 3994 3995 PROC_LOCK(p1); 3996 is_using_hwpmcs = p1->p_flag & P_HWPMC; 3997 PROC_UNLOCK(p1); 3998 3999 /* 4000 * If there are system-wide sampling PMCs active, we need to 4001 * log all fork events to their owner's logs. 4002 */ 4003 4004 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4005 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4006 pmclog_process_procfork(po, p1->p_pid, newproc->p_pid); 4007 4008 if (!is_using_hwpmcs) 4009 return; 4010 4011 PMC_GET_SX_XLOCK(); 4012 PMCDBG(PMC,FRK,1, "process-fork proc=%p (%d, %s) -> %p", p1, 4013 p1->p_pid, p1->p_comm, newproc); 4014 4015 /* 4016 * If the parent process (curthread->td_proc) is a 4017 * target of any PMCs, look for PMCs that are to be 4018 * inherited, and link these into the new process 4019 * descriptor. 4020 */ 4021 if ((ppold = pmc_find_process_descriptor(curthread->td_proc, 4022 PMC_FLAG_NONE)) == NULL) 4023 goto done; /* nothing to do */ 4024 4025 do_descendants = 0; 4026 for (ri = 0; ri < md->pmd_npmc; ri++) 4027 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL) 4028 do_descendants |= pm->pm_flags & PMC_F_DESCENDANTS; 4029 if (do_descendants == 0) /* nothing to do */ 4030 goto done; 4031 4032 /* allocate a descriptor for the new process */ 4033 if ((ppnew = pmc_find_process_descriptor(newproc, 4034 PMC_FLAG_ALLOCATE)) == NULL) 4035 goto done; 4036 4037 /* 4038 * Run through all PMCs that were targeting the old process 4039 * and which specified F_DESCENDANTS and attach them to the 4040 * new process. 4041 * 4042 * Log the fork event to all owners of PMCs attached to this 4043 * process, if not already logged. 4044 */ 4045 for (ri = 0; ri < md->pmd_npmc; ri++) 4046 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL && 4047 (pm->pm_flags & PMC_F_DESCENDANTS)) { 4048 pmc_link_target_process(pm, ppnew); 4049 po = pm->pm_owner; 4050 if (po->po_sscount == 0 && 4051 po->po_flags & PMC_PO_OWNS_LOGFILE) 4052 pmclog_process_procfork(po, p1->p_pid, 4053 newproc->p_pid); 4054 } 4055 4056 /* 4057 * Now mark the new process as being tracked by this driver. 4058 */ 4059 PROC_LOCK(newproc); 4060 newproc->p_flag |= P_HWPMC; 4061 PROC_UNLOCK(newproc); 4062 4063 done: 4064 sx_xunlock(&pmc_sx); 4065 } 4066 4067 4068 /* 4069 * initialization 4070 */ 4071 4072 static const char *pmc_name_of_pmcclass[] = { 4073 #undef __PMC_CLASS 4074 #define __PMC_CLASS(N) #N , 4075 __PMC_CLASSES() 4076 }; 4077 4078 static int 4079 pmc_initialize(void) 4080 { 4081 int cpu, error, n; 4082 struct pmc_binding pb; 4083 struct pmc_samplebuffer *sb; 4084 4085 md = NULL; 4086 error = 0; 4087 4088 #ifdef DEBUG 4089 /* parse debug flags first */ 4090 if (TUNABLE_STR_FETCH(PMC_SYSCTL_NAME_PREFIX "debugflags", 4091 pmc_debugstr, sizeof(pmc_debugstr))) 4092 pmc_debugflags_parse(pmc_debugstr, 4093 pmc_debugstr+strlen(pmc_debugstr)); 4094 #endif 4095 4096 PMCDBG(MOD,INI,0, "PMC Initialize (version %x)", PMC_VERSION); 4097 4098 /* check kernel version */ 4099 if (pmc_kernel_version != PMC_VERSION) { 4100 if (pmc_kernel_version == 0) 4101 printf("hwpmc: this kernel has not been compiled with " 4102 "'options HWPMC_HOOKS'.\n"); 4103 else 4104 printf("hwpmc: kernel version (0x%x) does not match " 4105 "module version (0x%x).\n", pmc_kernel_version, 4106 PMC_VERSION); 4107 return EPROGMISMATCH; 4108 } 4109 4110 /* 4111 * check sysctl parameters 4112 */ 4113 4114 if (pmc_hashsize <= 0) { 4115 (void) printf("hwpmc: tunable hashsize=%d must be greater " 4116 "than zero.\n", pmc_hashsize); 4117 pmc_hashsize = PMC_HASH_SIZE; 4118 } 4119 4120 if (pmc_nsamples <= 0 || pmc_nsamples > 65535) { 4121 (void) printf("hwpmc: tunable nsamples=%d out of range.\n", 4122 pmc_nsamples); 4123 pmc_nsamples = PMC_NSAMPLES; 4124 } 4125 4126 md = pmc_md_initialize(); 4127 4128 if (md == NULL || md->pmd_init == NULL) 4129 return ENOSYS; 4130 4131 /* allocate space for the per-cpu array */ 4132 MALLOC(pmc_pcpu, struct pmc_cpu **, mp_ncpus * sizeof(struct pmc_cpu *), 4133 M_PMC, M_WAITOK|M_ZERO); 4134 4135 /* per-cpu 'saved values' for managing process-mode PMCs */ 4136 MALLOC(pmc_pcpu_saved, pmc_value_t *, 4137 sizeof(pmc_value_t) * mp_ncpus * md->pmd_npmc, M_PMC, M_WAITOK); 4138 4139 /* perform cpu dependent initialization */ 4140 pmc_save_cpu_binding(&pb); 4141 for (cpu = 0; cpu < mp_ncpus; cpu++) { 4142 if (pmc_cpu_is_disabled(cpu)) 4143 continue; 4144 pmc_select_cpu(cpu); 4145 if ((error = md->pmd_init(cpu)) != 0) 4146 break; 4147 } 4148 pmc_restore_cpu_binding(&pb); 4149 4150 if (error != 0) 4151 return error; 4152 4153 /* allocate space for the sample array */ 4154 for (cpu = 0; cpu < mp_ncpus; cpu++) { 4155 if (pmc_cpu_is_disabled(cpu)) 4156 continue; 4157 MALLOC(sb, struct pmc_samplebuffer *, 4158 sizeof(struct pmc_samplebuffer) + 4159 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 4160 M_WAITOK|M_ZERO); 4161 4162 sb->ps_read = sb->ps_write = sb->ps_samples; 4163 sb->ps_fence = sb->ps_samples + pmc_nsamples; 4164 KASSERT(pmc_pcpu[cpu] != NULL, 4165 ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu)); 4166 4167 pmc_pcpu[cpu]->pc_sb = sb; 4168 } 4169 4170 /* allocate space for the row disposition array */ 4171 pmc_pmcdisp = malloc(sizeof(enum pmc_mode) * md->pmd_npmc, 4172 M_PMC, M_WAITOK|M_ZERO); 4173 4174 KASSERT(pmc_pmcdisp != NULL, 4175 ("[pmc,%d] pmcdisp allocation returned NULL", __LINE__)); 4176 4177 /* mark all PMCs as available */ 4178 for (n = 0; n < (int) md->pmd_npmc; n++) 4179 PMC_MARK_ROW_FREE(n); 4180 4181 /* allocate thread hash tables */ 4182 pmc_ownerhash = hashinit(pmc_hashsize, M_PMC, 4183 &pmc_ownerhashmask); 4184 4185 pmc_processhash = hashinit(pmc_hashsize, M_PMC, 4186 &pmc_processhashmask); 4187 mtx_init(&pmc_processhash_mtx, "pmc-process-hash", "pmc", MTX_SPIN); 4188 4189 LIST_INIT(&pmc_ss_owners); 4190 pmc_ss_count = 0; 4191 4192 /* allocate a pool of spin mutexes */ 4193 pmc_mtxpool = mtx_pool_create("pmc", pmc_mtxpool_size, MTX_SPIN); 4194 4195 PMCDBG(MOD,INI,1, "pmc_ownerhash=%p, mask=0x%lx " 4196 "targethash=%p mask=0x%lx", pmc_ownerhash, pmc_ownerhashmask, 4197 pmc_processhash, pmc_processhashmask); 4198 4199 /* register process {exit,fork,exec} handlers */ 4200 pmc_exit_tag = EVENTHANDLER_REGISTER(process_exit, 4201 pmc_process_exit, NULL, EVENTHANDLER_PRI_ANY); 4202 pmc_fork_tag = EVENTHANDLER_REGISTER(process_fork, 4203 pmc_process_fork, NULL, EVENTHANDLER_PRI_ANY); 4204 4205 /* initialize logging */ 4206 pmclog_initialize(); 4207 4208 /* set hook functions */ 4209 pmc_intr = md->pmd_intr; 4210 pmc_hook = pmc_hook_handler; 4211 4212 if (error == 0) { 4213 printf(PMC_MODULE_NAME ":"); 4214 for (n = 0; n < (int) md->pmd_nclass; n++) { 4215 printf(" %s/%d/0x%b", 4216 pmc_name_of_pmcclass[md->pmd_classes[n].pm_class], 4217 md->pmd_nclasspmcs[n], 4218 md->pmd_classes[n].pm_caps, 4219 "\20" 4220 "\1INT\2USR\3SYS\4EDG\5THR" 4221 "\6REA\7WRI\10INV\11QUA\12PRC" 4222 "\13TAG\14CSC"); 4223 } 4224 printf("\n"); 4225 } 4226 4227 return error; 4228 } 4229 4230 /* prepare to be unloaded */ 4231 static void 4232 pmc_cleanup(void) 4233 { 4234 int cpu; 4235 struct pmc_ownerhash *ph; 4236 struct pmc_owner *po, *tmp; 4237 struct pmc_binding pb; 4238 #ifdef DEBUG 4239 struct pmc_processhash *prh; 4240 #endif 4241 4242 PMCDBG(MOD,INI,0, "%s", "cleanup"); 4243 4244 /* switch off sampling */ 4245 atomic_store_rel_int(&pmc_cpumask, 0); 4246 pmc_intr = NULL; 4247 4248 sx_xlock(&pmc_sx); 4249 if (pmc_hook == NULL) { /* being unloaded already */ 4250 sx_xunlock(&pmc_sx); 4251 return; 4252 } 4253 4254 pmc_hook = NULL; /* prevent new threads from entering module */ 4255 4256 /* deregister event handlers */ 4257 EVENTHANDLER_DEREGISTER(process_fork, pmc_fork_tag); 4258 EVENTHANDLER_DEREGISTER(process_exit, pmc_exit_tag); 4259 4260 /* send SIGBUS to all owner threads, free up allocations */ 4261 if (pmc_ownerhash) 4262 for (ph = pmc_ownerhash; 4263 ph <= &pmc_ownerhash[pmc_ownerhashmask]; 4264 ph++) { 4265 LIST_FOREACH_SAFE(po, ph, po_next, tmp) { 4266 pmc_remove_owner(po); 4267 4268 /* send SIGBUS to owner processes */ 4269 PMCDBG(MOD,INI,2, "cleanup signal proc=%p " 4270 "(%d, %s)", po->po_owner, 4271 po->po_owner->p_pid, 4272 po->po_owner->p_comm); 4273 4274 PROC_LOCK(po->po_owner); 4275 psignal(po->po_owner, SIGBUS); 4276 PROC_UNLOCK(po->po_owner); 4277 4278 pmc_destroy_owner_descriptor(po); 4279 } 4280 } 4281 4282 /* reclaim allocated data structures */ 4283 if (pmc_mtxpool) 4284 mtx_pool_destroy(&pmc_mtxpool); 4285 4286 mtx_destroy(&pmc_processhash_mtx); 4287 if (pmc_processhash) { 4288 #ifdef DEBUG 4289 struct pmc_process *pp; 4290 4291 PMCDBG(MOD,INI,3, "%s", "destroy process hash"); 4292 for (prh = pmc_processhash; 4293 prh <= &pmc_processhash[pmc_processhashmask]; 4294 prh++) 4295 LIST_FOREACH(pp, prh, pp_next) 4296 PMCDBG(MOD,INI,3, "pid=%d", pp->pp_proc->p_pid); 4297 #endif 4298 4299 hashdestroy(pmc_processhash, M_PMC, pmc_processhashmask); 4300 pmc_processhash = NULL; 4301 } 4302 4303 if (pmc_ownerhash) { 4304 PMCDBG(MOD,INI,3, "%s", "destroy owner hash"); 4305 hashdestroy(pmc_ownerhash, M_PMC, pmc_ownerhashmask); 4306 pmc_ownerhash = NULL; 4307 } 4308 4309 KASSERT(LIST_EMPTY(&pmc_ss_owners), 4310 ("[pmc,%d] Global SS owner list not empty", __LINE__)); 4311 KASSERT(pmc_ss_count == 0, 4312 ("[pmc,%d] Global SS count not empty", __LINE__)); 4313 4314 /* free the per-cpu sample buffers */ 4315 for (cpu = 0; cpu < mp_ncpus; cpu++) { 4316 if (pmc_cpu_is_disabled(cpu)) 4317 continue; 4318 KASSERT(pmc_pcpu[cpu]->pc_sb != NULL, 4319 ("[pmc,%d] Null cpu sample buffer cpu=%d", __LINE__, 4320 cpu)); 4321 FREE(pmc_pcpu[cpu]->pc_sb, M_PMC); 4322 pmc_pcpu[cpu]->pc_sb = NULL; 4323 } 4324 4325 /* do processor dependent cleanup */ 4326 PMCDBG(MOD,INI,3, "%s", "md cleanup"); 4327 if (md) { 4328 pmc_save_cpu_binding(&pb); 4329 for (cpu = 0; cpu < mp_ncpus; cpu++) { 4330 PMCDBG(MOD,INI,1,"pmc-cleanup cpu=%d pcs=%p", 4331 cpu, pmc_pcpu[cpu]); 4332 if (pmc_cpu_is_disabled(cpu)) 4333 continue; 4334 pmc_select_cpu(cpu); 4335 if (pmc_pcpu[cpu]) 4336 (void) md->pmd_cleanup(cpu); 4337 } 4338 FREE(md, M_PMC); 4339 md = NULL; 4340 pmc_restore_cpu_binding(&pb); 4341 } 4342 4343 /* deallocate per-cpu structures */ 4344 FREE(pmc_pcpu, M_PMC); 4345 pmc_pcpu = NULL; 4346 4347 FREE(pmc_pcpu_saved, M_PMC); 4348 pmc_pcpu_saved = NULL; 4349 4350 if (pmc_pmcdisp) { 4351 FREE(pmc_pmcdisp, M_PMC); 4352 pmc_pmcdisp = NULL; 4353 } 4354 4355 pmclog_shutdown(); 4356 4357 sx_xunlock(&pmc_sx); /* we are done */ 4358 } 4359 4360 /* 4361 * The function called at load/unload. 4362 */ 4363 4364 static int 4365 load (struct module *module __unused, int cmd, void *arg __unused) 4366 { 4367 int error; 4368 4369 error = 0; 4370 4371 switch (cmd) { 4372 case MOD_LOAD : 4373 /* initialize the subsystem */ 4374 error = pmc_initialize(); 4375 if (error != 0) 4376 break; 4377 PMCDBG(MOD,INI,1, "syscall=%d ncpus=%d", 4378 pmc_syscall_num, mp_ncpus); 4379 break; 4380 4381 4382 case MOD_UNLOAD : 4383 case MOD_SHUTDOWN: 4384 pmc_cleanup(); 4385 PMCDBG(MOD,INI,1, "%s", "unloaded"); 4386 break; 4387 4388 default : 4389 error = EINVAL; /* XXX should panic(9) */ 4390 break; 4391 } 4392 4393 return error; 4394 } 4395 4396 /* memory pool */ 4397 MALLOC_DEFINE(M_PMC, "pmc", "Memory space for the PMC module"); 4398