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 * - The global SX lock "pmc_sx" is used to protect internal 499 * data structures. 500 * 501 * Calls into the module by syscall() start with this lock being 502 * held in exclusive mode. Depending on the requested operation, 503 * the lock may be downgraded to 'shared' mode to allow more 504 * concurrent readers into the module. Calls into the module from 505 * other parts of the kernel acquire the lock in shared mode. 506 * 507 * This SX lock is held in exclusive mode for any operations that 508 * modify the linkages between the driver's internal data structures. 509 * 510 * The 'pmc_hook' function pointer is also protected by this lock. 511 * It is only examined with the sx lock held in exclusive mode. The 512 * kernel module is allowed to be unloaded only with the sx lock held 513 * in exclusive mode. In normal syscall handling, after acquiring the 514 * pmc_sx lock we first check that 'pmc_hook' is non-null before 515 * proceeding. This prevents races between the thread unloading the module 516 * and other threads seeking to use the 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". 524 * 525 * - Interrupt handlers work in a lock free manner. At interrupt 526 * time, handlers look at the PMC pointer (phw->phw_pmc) configured 527 * when the PMC was started. If this pointer is NULL, the interrupt 528 * is ignored after updating driver statistics. We ensure that this 529 * pointer is set (using an atomic operation if necessary) before the 530 * PMC hardware is started. Conversely, this pointer is unset atomically 531 * only after the PMC hardware is stopped. 532 * 533 * We ensure that everything needed for the operation of an 534 * interrupt handler is available without it needing to acquire any 535 * locks. We also ensure that a PMC's software state is destroyed only 536 * after the PMC is taken off hardware (on all CPUs). 537 * 538 * - Context-switch handling with process-private PMCs needs more 539 * care. 540 * 541 * A given process may be the target of multiple PMCs. For example, 542 * PMCATTACH and PMCDETACH may be requested by a process on one CPU 543 * while the target process is running on another. A PMC could also 544 * be getting released because its owner is exiting. We tackle 545 * these situations in the following manner: 546 * 547 * - each target process structure 'pmc_process' has an array 548 * of 'struct pmc *' pointers, one for each hardware PMC. 549 * 550 * - At context switch IN time, each "target" PMC in RUNNING state 551 * gets started on hardware and a pointer to each PMC is copied into 552 * the per-cpu phw array. The 'runcount' for the PMC is 553 * incremented. 554 * 555 * - At context switch OUT time, all process-virtual PMCs are stopped 556 * on hardware. The saved value is added to the PMCs value field 557 * only if the PMC is in a non-deleted state (the PMCs state could 558 * have changed during the current time slice). 559 * 560 * Note that since in-between a switch IN on a processor and a switch 561 * OUT, the PMC could have been released on another CPU. Therefore 562 * context switch OUT always looks at the hardware state to turn 563 * OFF PMCs and will update a PMC's saved value only if reachable 564 * from the target process record. 565 * 566 * - OP PMCRELEASE could be called on a PMC at any time (the PMC could 567 * be attached to many processes at the time of the call and could 568 * be active on multiple CPUs). 569 * 570 * We prevent further scheduling of the PMC by marking it as in 571 * state 'DELETED'. If the runcount of the PMC is non-zero then 572 * this PMC is currently running on a CPU somewhere. The thread 573 * doing the PMCRELEASE operation waits by repeatedly doing a 574 * pause() till the runcount comes to zero. 575 * 576 * The contents of a PMC descriptor (struct pmc) are protected using 577 * a spin-mutex. In order to save space, we use a mutex pool. 578 * 579 * In terms of lock types used by witness(4), we use: 580 * - Type "pmc-sx", used by the global SX lock. 581 * - Type "pmc-sleep", for sleep mutexes used by logger threads. 582 * - Type "pmc-per-proc", for protecting PMC owner descriptors. 583 * - Type "pmc-leaf", used for all other spin mutexes. 584 */ 585 586 /* 587 * save the cpu binding of the current kthread 588 */ 589 590 static void 591 pmc_save_cpu_binding(struct pmc_binding *pb) 592 { 593 PMCDBG(CPU,BND,2, "%s", "save-cpu"); 594 thread_lock(curthread); 595 pb->pb_bound = sched_is_bound(curthread); 596 pb->pb_cpu = curthread->td_oncpu; 597 thread_unlock(curthread); 598 PMCDBG(CPU,BND,2, "save-cpu cpu=%d", pb->pb_cpu); 599 } 600 601 /* 602 * restore the cpu binding of the current thread 603 */ 604 605 static void 606 pmc_restore_cpu_binding(struct pmc_binding *pb) 607 { 608 PMCDBG(CPU,BND,2, "restore-cpu curcpu=%d restore=%d", 609 curthread->td_oncpu, pb->pb_cpu); 610 thread_lock(curthread); 611 if (pb->pb_bound) 612 sched_bind(curthread, pb->pb_cpu); 613 else 614 sched_unbind(curthread); 615 thread_unlock(curthread); 616 PMCDBG(CPU,BND,2, "%s", "restore-cpu done"); 617 } 618 619 /* 620 * move execution over the specified cpu and bind it there. 621 */ 622 623 static void 624 pmc_select_cpu(int cpu) 625 { 626 KASSERT(cpu >= 0 && cpu < mp_ncpus, 627 ("[pmc,%d] bad cpu number %d", __LINE__, cpu)); 628 629 /* never move to a disabled CPU */ 630 KASSERT(pmc_cpu_is_disabled(cpu) == 0, ("[pmc,%d] selecting " 631 "disabled CPU %d", __LINE__, cpu)); 632 633 PMCDBG(CPU,SEL,2, "select-cpu cpu=%d", cpu); 634 thread_lock(curthread); 635 sched_bind(curthread, cpu); 636 thread_unlock(curthread); 637 638 KASSERT(curthread->td_oncpu == cpu, 639 ("[pmc,%d] CPU not bound [cpu=%d, curr=%d]", __LINE__, 640 cpu, curthread->td_oncpu)); 641 642 PMCDBG(CPU,SEL,2, "select-cpu cpu=%d ok", cpu); 643 } 644 645 /* 646 * Force a context switch. 647 * 648 * We do this by pause'ing for 1 tick -- invoking mi_switch() is not 649 * guaranteed to force a context switch. 650 */ 651 652 static void 653 pmc_force_context_switch(void) 654 { 655 656 pause("pmcctx", 1); 657 } 658 659 /* 660 * Get the file name for an executable. This is a simple wrapper 661 * around vn_fullpath(9). 662 */ 663 664 static void 665 pmc_getfilename(struct vnode *v, char **fullpath, char **freepath) 666 { 667 struct thread *td; 668 669 td = curthread; 670 *fullpath = "unknown"; 671 *freepath = NULL; 672 vn_lock(v, LK_CANRECURSE | LK_EXCLUSIVE | LK_RETRY, td); 673 vn_fullpath(td, v, fullpath, freepath); 674 VOP_UNLOCK(v, 0, td); 675 } 676 677 /* 678 * remove an process owning PMCs 679 */ 680 681 void 682 pmc_remove_owner(struct pmc_owner *po) 683 { 684 struct pmc *pm, *tmp; 685 686 sx_assert(&pmc_sx, SX_XLOCKED); 687 688 PMCDBG(OWN,ORM,1, "remove-owner po=%p", po); 689 690 /* Remove descriptor from the owner hash table */ 691 LIST_REMOVE(po, po_next); 692 693 /* release all owned PMC descriptors */ 694 LIST_FOREACH_SAFE(pm, &po->po_pmcs, pm_next, tmp) { 695 PMCDBG(OWN,ORM,2, "pmc=%p", pm); 696 KASSERT(pm->pm_owner == po, 697 ("[pmc,%d] owner %p != po %p", __LINE__, pm->pm_owner, po)); 698 699 pmc_release_pmc_descriptor(pm); /* will unlink from the list */ 700 } 701 702 KASSERT(po->po_sscount == 0, 703 ("[pmc,%d] SS count not zero", __LINE__)); 704 KASSERT(LIST_EMPTY(&po->po_pmcs), 705 ("[pmc,%d] PMC list not empty", __LINE__)); 706 707 /* de-configure the log file if present */ 708 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 709 pmclog_deconfigure_log(po); 710 } 711 712 /* 713 * remove an owner process record if all conditions are met. 714 */ 715 716 static void 717 pmc_maybe_remove_owner(struct pmc_owner *po) 718 { 719 720 PMCDBG(OWN,OMR,1, "maybe-remove-owner po=%p", po); 721 722 /* 723 * Remove owner record if 724 * - this process does not own any PMCs 725 * - this process has not allocated a system-wide sampling buffer 726 */ 727 728 if (LIST_EMPTY(&po->po_pmcs) && 729 ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0)) { 730 pmc_remove_owner(po); 731 pmc_destroy_owner_descriptor(po); 732 } 733 } 734 735 /* 736 * Add an association between a target process and a PMC. 737 */ 738 739 static void 740 pmc_link_target_process(struct pmc *pm, struct pmc_process *pp) 741 { 742 int ri; 743 struct pmc_target *pt; 744 745 sx_assert(&pmc_sx, SX_XLOCKED); 746 747 KASSERT(pm != NULL && pp != NULL, 748 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 749 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 750 ("[pmc,%d] Attaching a non-process-virtual pmc=%p to pid=%d", 751 __LINE__, pm, pp->pp_proc->p_pid)); 752 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt < ((int) md->pmd_npmc - 1), 753 ("[pmc,%d] Illegal reference count %d for process record %p", 754 __LINE__, pp->pp_refcnt, (void *) pp)); 755 756 ri = PMC_TO_ROWINDEX(pm); 757 758 PMCDBG(PRC,TLK,1, "link-target pmc=%p ri=%d pmc-process=%p", 759 pm, ri, pp); 760 761 #ifdef DEBUG 762 LIST_FOREACH(pt, &pm->pm_targets, pt_next) 763 if (pt->pt_process == pp) 764 KASSERT(0, ("[pmc,%d] pp %p already in pmc %p targets", 765 __LINE__, pp, pm)); 766 #endif 767 768 MALLOC(pt, struct pmc_target *, sizeof(struct pmc_target), 769 M_PMC, M_ZERO|M_WAITOK); 770 771 pt->pt_process = pp; 772 773 LIST_INSERT_HEAD(&pm->pm_targets, pt, pt_next); 774 775 atomic_store_rel_ptr((uintptr_t *)&pp->pp_pmcs[ri].pp_pmc, 776 (uintptr_t)pm); 777 778 if (pm->pm_owner->po_owner == pp->pp_proc) 779 pm->pm_flags |= PMC_F_ATTACHED_TO_OWNER; 780 781 /* 782 * Initialize the per-process values at this row index. 783 */ 784 pp->pp_pmcs[ri].pp_pmcval = PMC_TO_MODE(pm) == PMC_MODE_TS ? 785 pm->pm_sc.pm_reloadcount : 0; 786 787 pp->pp_refcnt++; 788 789 } 790 791 /* 792 * Removes the association between a target process and a PMC. 793 */ 794 795 static void 796 pmc_unlink_target_process(struct pmc *pm, struct pmc_process *pp) 797 { 798 int ri; 799 struct proc *p; 800 struct pmc_target *ptgt; 801 802 sx_assert(&pmc_sx, SX_XLOCKED); 803 804 KASSERT(pm != NULL && pp != NULL, 805 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 806 807 KASSERT(pp->pp_refcnt >= 1 && pp->pp_refcnt < (int) md->pmd_npmc, 808 ("[pmc,%d] Illegal ref count %d on process record %p", 809 __LINE__, pp->pp_refcnt, (void *) pp)); 810 811 ri = PMC_TO_ROWINDEX(pm); 812 813 PMCDBG(PRC,TUL,1, "unlink-target pmc=%p ri=%d pmc-process=%p", 814 pm, ri, pp); 815 816 KASSERT(pp->pp_pmcs[ri].pp_pmc == pm, 817 ("[pmc,%d] PMC ri %d mismatch pmc %p pp->[ri] %p", __LINE__, 818 ri, pm, pp->pp_pmcs[ri].pp_pmc)); 819 820 pp->pp_pmcs[ri].pp_pmc = NULL; 821 pp->pp_pmcs[ri].pp_pmcval = (pmc_value_t) 0; 822 823 /* Remove owner-specific flags */ 824 if (pm->pm_owner->po_owner == pp->pp_proc) { 825 pp->pp_flags &= ~PMC_PP_ENABLE_MSR_ACCESS; 826 pm->pm_flags &= ~PMC_F_ATTACHED_TO_OWNER; 827 } 828 829 pp->pp_refcnt--; 830 831 /* Remove the target process from the PMC structure */ 832 LIST_FOREACH(ptgt, &pm->pm_targets, pt_next) 833 if (ptgt->pt_process == pp) 834 break; 835 836 KASSERT(ptgt != NULL, ("[pmc,%d] process %p (pp: %p) not found " 837 "in pmc %p", __LINE__, pp->pp_proc, pp, pm)); 838 839 LIST_REMOVE(ptgt, pt_next); 840 FREE(ptgt, M_PMC); 841 842 /* if the PMC now lacks targets, send the owner a SIGIO */ 843 if (LIST_EMPTY(&pm->pm_targets)) { 844 p = pm->pm_owner->po_owner; 845 PROC_LOCK(p); 846 psignal(p, SIGIO); 847 PROC_UNLOCK(p); 848 849 PMCDBG(PRC,SIG,2, "signalling proc=%p signal=%d", p, 850 SIGIO); 851 } 852 } 853 854 /* 855 * Check if PMC 'pm' may be attached to target process 't'. 856 */ 857 858 static int 859 pmc_can_attach(struct pmc *pm, struct proc *t) 860 { 861 struct proc *o; /* pmc owner */ 862 struct ucred *oc, *tc; /* owner, target credentials */ 863 int decline_attach, i; 864 865 /* 866 * A PMC's owner can always attach that PMC to itself. 867 */ 868 869 if ((o = pm->pm_owner->po_owner) == t) 870 return 0; 871 872 PROC_LOCK(o); 873 oc = o->p_ucred; 874 crhold(oc); 875 PROC_UNLOCK(o); 876 877 PROC_LOCK(t); 878 tc = t->p_ucred; 879 crhold(tc); 880 PROC_UNLOCK(t); 881 882 /* 883 * The effective uid of the PMC owner should match at least one 884 * of the {effective,real,saved} uids of the target process. 885 */ 886 887 decline_attach = oc->cr_uid != tc->cr_uid && 888 oc->cr_uid != tc->cr_svuid && 889 oc->cr_uid != tc->cr_ruid; 890 891 /* 892 * Every one of the target's group ids, must be in the owner's 893 * group list. 894 */ 895 for (i = 0; !decline_attach && i < tc->cr_ngroups; i++) 896 decline_attach = !groupmember(tc->cr_groups[i], oc); 897 898 /* check the read and saved gids too */ 899 if (decline_attach == 0) 900 decline_attach = !groupmember(tc->cr_rgid, oc) || 901 !groupmember(tc->cr_svgid, oc); 902 903 crfree(tc); 904 crfree(oc); 905 906 return !decline_attach; 907 } 908 909 /* 910 * Attach a process to a PMC. 911 */ 912 913 static int 914 pmc_attach_one_process(struct proc *p, struct pmc *pm) 915 { 916 int ri; 917 char *fullpath, *freepath; 918 struct pmc_process *pp; 919 920 sx_assert(&pmc_sx, SX_XLOCKED); 921 922 PMCDBG(PRC,ATT,2, "attach-one pm=%p ri=%d proc=%p (%d, %s)", pm, 923 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 924 925 /* 926 * Locate the process descriptor corresponding to process 'p', 927 * allocating space as needed. 928 * 929 * Verify that rowindex 'pm_rowindex' is free in the process 930 * descriptor. 931 * 932 * If not, allocate space for a descriptor and link the 933 * process descriptor and PMC. 934 */ 935 ri = PMC_TO_ROWINDEX(pm); 936 937 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_ALLOCATE)) == NULL) 938 return ENOMEM; 939 940 if (pp->pp_pmcs[ri].pp_pmc == pm) /* already present at slot [ri] */ 941 return EEXIST; 942 943 if (pp->pp_pmcs[ri].pp_pmc != NULL) 944 return EBUSY; 945 946 pmc_link_target_process(pm, pp); 947 948 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) && 949 (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) == 0) 950 pm->pm_flags |= PMC_F_NEEDS_LOGFILE; 951 952 pm->pm_flags |= PMC_F_ATTACH_DONE; /* mark as attached */ 953 954 /* issue an attach event to a configured log file */ 955 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) { 956 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 957 pmclog_process_pmcattach(pm, p->p_pid, fullpath); 958 if (freepath) 959 FREE(freepath, M_TEMP); 960 } 961 /* mark process as using HWPMCs */ 962 PROC_LOCK(p); 963 p->p_flag |= P_HWPMC; 964 PROC_UNLOCK(p); 965 966 return 0; 967 } 968 969 /* 970 * Attach a process and optionally its children 971 */ 972 973 static int 974 pmc_attach_process(struct proc *p, struct pmc *pm) 975 { 976 int error; 977 struct proc *top; 978 979 sx_assert(&pmc_sx, SX_XLOCKED); 980 981 PMCDBG(PRC,ATT,1, "attach pm=%p ri=%d proc=%p (%d, %s)", pm, 982 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 983 984 985 /* 986 * If this PMC successfully allowed a GETMSR operation 987 * in the past, disallow further ATTACHes. 988 */ 989 990 if ((pm->pm_flags & PMC_PP_ENABLE_MSR_ACCESS) != 0) 991 return EPERM; 992 993 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 994 return pmc_attach_one_process(p, pm); 995 996 /* 997 * Traverse all child processes, attaching them to 998 * this PMC. 999 */ 1000 1001 sx_slock(&proctree_lock); 1002 1003 top = p; 1004 1005 for (;;) { 1006 if ((error = pmc_attach_one_process(p, pm)) != 0) 1007 break; 1008 if (!LIST_EMPTY(&p->p_children)) 1009 p = LIST_FIRST(&p->p_children); 1010 else for (;;) { 1011 if (p == top) 1012 goto done; 1013 if (LIST_NEXT(p, p_sibling)) { 1014 p = LIST_NEXT(p, p_sibling); 1015 break; 1016 } 1017 p = p->p_pptr; 1018 } 1019 } 1020 1021 if (error) 1022 (void) pmc_detach_process(top, pm); 1023 1024 done: 1025 sx_sunlock(&proctree_lock); 1026 return error; 1027 } 1028 1029 /* 1030 * Detach a process from a PMC. If there are no other PMCs tracking 1031 * this process, remove the process structure from its hash table. If 1032 * 'flags' contains PMC_FLAG_REMOVE, then free the process structure. 1033 */ 1034 1035 static int 1036 pmc_detach_one_process(struct proc *p, struct pmc *pm, int flags) 1037 { 1038 int ri; 1039 struct pmc_process *pp; 1040 1041 sx_assert(&pmc_sx, SX_XLOCKED); 1042 1043 KASSERT(pm != NULL, 1044 ("[pmc,%d] null pm pointer", __LINE__)); 1045 1046 ri = PMC_TO_ROWINDEX(pm); 1047 1048 PMCDBG(PRC,ATT,2, "detach-one pm=%p ri=%d proc=%p (%d, %s) flags=0x%x", 1049 pm, ri, p, p->p_pid, p->p_comm, flags); 1050 1051 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) 1052 return ESRCH; 1053 1054 if (pp->pp_pmcs[ri].pp_pmc != pm) 1055 return EINVAL; 1056 1057 pmc_unlink_target_process(pm, pp); 1058 1059 /* Issue a detach entry if a log file is configured */ 1060 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) 1061 pmclog_process_pmcdetach(pm, p->p_pid); 1062 1063 /* 1064 * If there are no PMCs targetting this process, we remove its 1065 * descriptor from the target hash table and unset the P_HWPMC 1066 * flag in the struct proc. 1067 */ 1068 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt < (int) md->pmd_npmc, 1069 ("[pmc,%d] Illegal refcnt %d for process struct %p", 1070 __LINE__, pp->pp_refcnt, pp)); 1071 1072 if (pp->pp_refcnt != 0) /* still a target of some PMC */ 1073 return 0; 1074 1075 pmc_remove_process_descriptor(pp); 1076 1077 if (flags & PMC_FLAG_REMOVE) 1078 FREE(pp, M_PMC); 1079 1080 PROC_LOCK(p); 1081 p->p_flag &= ~P_HWPMC; 1082 PROC_UNLOCK(p); 1083 1084 return 0; 1085 } 1086 1087 /* 1088 * Detach a process and optionally its descendants from a PMC. 1089 */ 1090 1091 static int 1092 pmc_detach_process(struct proc *p, struct pmc *pm) 1093 { 1094 struct proc *top; 1095 1096 sx_assert(&pmc_sx, SX_XLOCKED); 1097 1098 PMCDBG(PRC,ATT,1, "detach pm=%p ri=%d proc=%p (%d, %s)", pm, 1099 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1100 1101 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 1102 return pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); 1103 1104 /* 1105 * Traverse all children, detaching them from this PMC. We 1106 * ignore errors since we could be detaching a PMC from a 1107 * partially attached proc tree. 1108 */ 1109 1110 sx_slock(&proctree_lock); 1111 1112 top = p; 1113 1114 for (;;) { 1115 (void) pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); 1116 1117 if (!LIST_EMPTY(&p->p_children)) 1118 p = LIST_FIRST(&p->p_children); 1119 else for (;;) { 1120 if (p == top) 1121 goto done; 1122 if (LIST_NEXT(p, p_sibling)) { 1123 p = LIST_NEXT(p, p_sibling); 1124 break; 1125 } 1126 p = p->p_pptr; 1127 } 1128 } 1129 1130 done: 1131 sx_sunlock(&proctree_lock); 1132 1133 if (LIST_EMPTY(&pm->pm_targets)) 1134 pm->pm_flags &= ~PMC_F_ATTACH_DONE; 1135 1136 return 0; 1137 } 1138 1139 1140 /* 1141 * Thread context switch IN 1142 */ 1143 1144 static void 1145 pmc_process_csw_in(struct thread *td) 1146 { 1147 int cpu; 1148 unsigned int ri; 1149 struct pmc *pm; 1150 struct proc *p; 1151 struct pmc_cpu *pc; 1152 struct pmc_hw *phw; 1153 struct pmc_process *pp; 1154 pmc_value_t newvalue; 1155 1156 p = td->td_proc; 1157 1158 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE)) == NULL) 1159 return; 1160 1161 KASSERT(pp->pp_proc == td->td_proc, 1162 ("[pmc,%d] not my thread state", __LINE__)); 1163 1164 critical_enter(); /* no preemption from this point */ 1165 1166 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1167 1168 PMCDBG(CSW,SWI,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1169 p->p_pid, p->p_comm, pp); 1170 1171 KASSERT(cpu >= 0 && cpu < mp_ncpus, 1172 ("[pmc,%d] wierd CPU id %d", __LINE__, cpu)); 1173 1174 pc = pmc_pcpu[cpu]; 1175 1176 for (ri = 0; ri < md->pmd_npmc; ri++) { 1177 1178 if ((pm = pp->pp_pmcs[ri].pp_pmc) == NULL) 1179 continue; 1180 1181 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 1182 ("[pmc,%d] Target PMC in non-virtual mode (%d)", 1183 __LINE__, PMC_TO_MODE(pm))); 1184 1185 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1186 ("[pmc,%d] Row index mismatch pmc %d != ri %d", 1187 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1188 1189 /* 1190 * Only PMCs that are marked as 'RUNNING' need 1191 * be placed on hardware. 1192 */ 1193 1194 if (pm->pm_state != PMC_STATE_RUNNING) 1195 continue; 1196 1197 /* increment PMC runcount */ 1198 atomic_add_rel_32(&pm->pm_runcount, 1); 1199 1200 /* configure the HWPMC we are going to use. */ 1201 md->pmd_config_pmc(cpu, ri, pm); 1202 1203 phw = pc->pc_hwpmcs[ri]; 1204 1205 KASSERT(phw != NULL, 1206 ("[pmc,%d] null hw pointer", __LINE__)); 1207 1208 KASSERT(phw->phw_pmc == pm, 1209 ("[pmc,%d] hw->pmc %p != pmc %p", __LINE__, 1210 phw->phw_pmc, pm)); 1211 1212 /* 1213 * Write out saved value and start the PMC. 1214 * 1215 * Sampling PMCs use a per-process value, while 1216 * counting mode PMCs use a per-pmc value that is 1217 * inherited across descendants. 1218 */ 1219 if (PMC_TO_MODE(pm) == PMC_MODE_TS) { 1220 mtx_pool_lock_spin(pmc_mtxpool, pm); 1221 newvalue = PMC_PCPU_SAVED(cpu,ri) = 1222 pp->pp_pmcs[ri].pp_pmcval; 1223 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1224 } else { 1225 KASSERT(PMC_TO_MODE(pm) == PMC_MODE_TC, 1226 ("[pmc,%d] illegal mode=%d", __LINE__, 1227 PMC_TO_MODE(pm))); 1228 mtx_pool_lock_spin(pmc_mtxpool, pm); 1229 newvalue = PMC_PCPU_SAVED(cpu, ri) = 1230 pm->pm_gv.pm_savedvalue; 1231 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1232 } 1233 1234 PMCDBG(CSW,SWI,1,"cpu=%d ri=%d new=%jd", cpu, ri, newvalue); 1235 1236 md->pmd_write_pmc(cpu, ri, newvalue); 1237 md->pmd_start_pmc(cpu, ri); 1238 } 1239 1240 /* 1241 * perform any other architecture/cpu dependent thread 1242 * switch-in actions. 1243 */ 1244 1245 (void) (*md->pmd_switch_in)(pc, pp); 1246 1247 critical_exit(); 1248 1249 } 1250 1251 /* 1252 * Thread context switch OUT. 1253 */ 1254 1255 static void 1256 pmc_process_csw_out(struct thread *td) 1257 { 1258 int cpu; 1259 enum pmc_mode mode; 1260 unsigned int ri; 1261 struct pmc *pm; 1262 struct proc *p; 1263 struct pmc_cpu *pc; 1264 struct pmc_process *pp; 1265 int64_t tmp; 1266 pmc_value_t newvalue; 1267 1268 /* 1269 * Locate our process descriptor; this may be NULL if 1270 * this process is exiting and we have already removed 1271 * the process from the target process table. 1272 * 1273 * Note that due to kernel preemption, multiple 1274 * context switches may happen while the process is 1275 * exiting. 1276 * 1277 * Note also that if the target process cannot be 1278 * found we still need to deconfigure any PMCs that 1279 * are currently running on hardware. 1280 */ 1281 1282 p = td->td_proc; 1283 pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE); 1284 1285 /* 1286 * save PMCs 1287 */ 1288 1289 critical_enter(); 1290 1291 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1292 1293 PMCDBG(CSW,SWO,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1294 p->p_pid, p->p_comm, pp); 1295 1296 KASSERT(cpu >= 0 && cpu < mp_ncpus, 1297 ("[pmc,%d wierd CPU id %d", __LINE__, cpu)); 1298 1299 pc = pmc_pcpu[cpu]; 1300 1301 /* 1302 * When a PMC gets unlinked from a target PMC, it will 1303 * be removed from the target's pp_pmc[] array. 1304 * 1305 * However, on a MP system, the target could have been 1306 * executing on another CPU at the time of the unlink. 1307 * So, at context switch OUT time, we need to look at 1308 * the hardware to determine if a PMC is scheduled on 1309 * it. 1310 */ 1311 1312 for (ri = 0; ri < md->pmd_npmc; ri++) { 1313 1314 pm = NULL; 1315 (void) (*md->pmd_get_config)(cpu, ri, &pm); 1316 1317 if (pm == NULL) /* nothing at this row index */ 1318 continue; 1319 1320 mode = PMC_TO_MODE(pm); 1321 if (!PMC_IS_VIRTUAL_MODE(mode)) 1322 continue; /* not a process virtual PMC */ 1323 1324 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1325 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 1326 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1327 1328 /* Stop hardware if not already stopped */ 1329 if (pm->pm_stalled == 0) 1330 md->pmd_stop_pmc(cpu, ri); 1331 1332 /* reduce this PMC's runcount */ 1333 atomic_subtract_rel_32(&pm->pm_runcount, 1); 1334 1335 /* 1336 * If this PMC is associated with this process, 1337 * save the reading. 1338 */ 1339 1340 if (pp != NULL && pp->pp_pmcs[ri].pp_pmc != NULL) { 1341 1342 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 1343 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", __LINE__, 1344 pm, ri, pp->pp_pmcs[ri].pp_pmc)); 1345 1346 KASSERT(pp->pp_refcnt > 0, 1347 ("[pmc,%d] pp refcnt = %d", __LINE__, 1348 pp->pp_refcnt)); 1349 1350 md->pmd_read_pmc(cpu, ri, &newvalue); 1351 1352 tmp = newvalue - PMC_PCPU_SAVED(cpu,ri); 1353 1354 PMCDBG(CSW,SWI,1,"cpu=%d ri=%d tmp=%jd", cpu, ri, 1355 tmp); 1356 1357 if (mode == PMC_MODE_TS) { 1358 1359 /* 1360 * For sampling process-virtual PMCs, 1361 * we expect the count to be 1362 * decreasing as the 'value' 1363 * programmed into the PMC is the 1364 * number of events to be seen till 1365 * the next sampling interrupt. 1366 */ 1367 if (tmp < 0) 1368 tmp += pm->pm_sc.pm_reloadcount; 1369 mtx_pool_lock_spin(pmc_mtxpool, pm); 1370 pp->pp_pmcs[ri].pp_pmcval -= tmp; 1371 if ((int64_t) pp->pp_pmcs[ri].pp_pmcval < 0) 1372 pp->pp_pmcs[ri].pp_pmcval += 1373 pm->pm_sc.pm_reloadcount; 1374 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1375 1376 } else { 1377 1378 /* 1379 * For counting process-virtual PMCs, 1380 * we expect the count to be 1381 * increasing monotonically, modulo a 64 1382 * bit wraparound. 1383 */ 1384 KASSERT((int64_t) tmp >= 0, 1385 ("[pmc,%d] negative increment cpu=%d " 1386 "ri=%d newvalue=%jx saved=%jx " 1387 "incr=%jx", __LINE__, cpu, ri, 1388 newvalue, PMC_PCPU_SAVED(cpu,ri), tmp)); 1389 1390 mtx_pool_lock_spin(pmc_mtxpool, pm); 1391 pm->pm_gv.pm_savedvalue += tmp; 1392 pp->pp_pmcs[ri].pp_pmcval += tmp; 1393 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1394 1395 if (pm->pm_flags & PMC_F_LOG_PROCCSW) 1396 pmclog_process_proccsw(pm, pp, tmp); 1397 } 1398 } 1399 1400 /* mark hardware as free */ 1401 md->pmd_config_pmc(cpu, ri, NULL); 1402 } 1403 1404 /* 1405 * perform any other architecture/cpu dependent thread 1406 * switch out functions. 1407 */ 1408 1409 (void) (*md->pmd_switch_out)(pc, pp); 1410 1411 critical_exit(); 1412 } 1413 1414 /* 1415 * Log a KLD operation. 1416 */ 1417 1418 static void 1419 pmc_process_kld_load(struct pmckern_map_in *pkm) 1420 { 1421 struct pmc_owner *po; 1422 1423 sx_assert(&pmc_sx, SX_LOCKED); 1424 1425 /* 1426 * Notify owners of system sampling PMCs about KLD operations. 1427 */ 1428 1429 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1430 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1431 pmclog_process_map_in(po, (pid_t) -1, pkm->pm_address, 1432 (char *) pkm->pm_file); 1433 1434 /* 1435 * TODO: Notify owners of (all) process-sampling PMCs too. 1436 */ 1437 1438 return; 1439 } 1440 1441 static void 1442 pmc_process_kld_unload(struct pmckern_map_out *pkm) 1443 { 1444 struct pmc_owner *po; 1445 1446 sx_assert(&pmc_sx, SX_LOCKED); 1447 1448 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1449 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1450 pmclog_process_map_out(po, (pid_t) -1, 1451 pkm->pm_address, pkm->pm_address + pkm->pm_size); 1452 1453 /* 1454 * TODO: Notify owners of process-sampling PMCs. 1455 */ 1456 } 1457 1458 /* 1459 * A mapping change for a process. 1460 */ 1461 1462 static void 1463 pmc_process_mmap(struct thread *td, struct pmckern_map_in *pkm) 1464 { 1465 int ri; 1466 pid_t pid; 1467 char *fullpath, *freepath; 1468 const struct pmc *pm; 1469 struct pmc_owner *po; 1470 const struct pmc_process *pp; 1471 1472 freepath = fullpath = NULL; 1473 pmc_getfilename((struct vnode *) pkm->pm_file, &fullpath, &freepath); 1474 1475 pid = td->td_proc->p_pid; 1476 1477 /* Inform owners of all system-wide sampling PMCs. */ 1478 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1479 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1480 pmclog_process_map_in(po, pid, pkm->pm_address, fullpath); 1481 1482 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1483 goto done; 1484 1485 /* 1486 * Inform sampling PMC owners tracking this process. 1487 */ 1488 for (ri = 0; ri < md->pmd_npmc; ri++) 1489 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1490 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1491 pmclog_process_map_in(pm->pm_owner, 1492 pid, pkm->pm_address, fullpath); 1493 1494 done: 1495 if (freepath) 1496 FREE(freepath, M_TEMP); 1497 } 1498 1499 1500 /* 1501 * Log an munmap request. 1502 */ 1503 1504 static void 1505 pmc_process_munmap(struct thread *td, struct pmckern_map_out *pkm) 1506 { 1507 int ri; 1508 pid_t pid; 1509 struct pmc_owner *po; 1510 const struct pmc *pm; 1511 const struct pmc_process *pp; 1512 1513 pid = td->td_proc->p_pid; 1514 1515 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1516 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1517 pmclog_process_map_out(po, pid, pkm->pm_address, 1518 pkm->pm_address + pkm->pm_size); 1519 1520 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1521 return; 1522 1523 for (ri = 0; ri < md->pmd_npmc; ri++) 1524 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1525 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1526 pmclog_process_map_out(pm->pm_owner, pid, 1527 pkm->pm_address, pkm->pm_address + pkm->pm_size); 1528 } 1529 1530 /* 1531 * The 'hook' invoked from the kernel proper 1532 */ 1533 1534 1535 #ifdef DEBUG 1536 const char *pmc_hooknames[] = { 1537 /* these strings correspond to PMC_FN_* in <sys/pmckern.h> */ 1538 "", 1539 "EXEC", 1540 "CSW-IN", 1541 "CSW-OUT", 1542 "SAMPLE", 1543 "KLDLOAD", 1544 "KLDUNLOAD", 1545 "MMAP", 1546 "MUNMAP" 1547 }; 1548 #endif 1549 1550 static int 1551 pmc_hook_handler(struct thread *td, int function, void *arg) 1552 { 1553 1554 PMCDBG(MOD,PMH,1, "hook td=%p func=%d \"%s\" arg=%p", td, function, 1555 pmc_hooknames[function], arg); 1556 1557 switch (function) 1558 { 1559 1560 /* 1561 * Process exec() 1562 */ 1563 1564 case PMC_FN_PROCESS_EXEC: 1565 { 1566 char *fullpath, *freepath; 1567 unsigned int ri; 1568 int is_using_hwpmcs; 1569 struct pmc *pm; 1570 struct proc *p; 1571 struct pmc_owner *po; 1572 struct pmc_process *pp; 1573 struct pmckern_procexec *pk; 1574 1575 sx_assert(&pmc_sx, SX_XLOCKED); 1576 1577 p = td->td_proc; 1578 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 1579 1580 pk = (struct pmckern_procexec *) arg; 1581 1582 /* Inform owners of SS mode PMCs of the exec event. */ 1583 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1584 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1585 pmclog_process_procexec(po, PMC_ID_INVALID, 1586 p->p_pid, pk->pm_entryaddr, fullpath); 1587 1588 PROC_LOCK(p); 1589 is_using_hwpmcs = p->p_flag & P_HWPMC; 1590 PROC_UNLOCK(p); 1591 1592 if (!is_using_hwpmcs) { 1593 if (freepath) 1594 FREE(freepath, M_TEMP); 1595 break; 1596 } 1597 1598 /* 1599 * PMCs are not inherited across an exec(): remove any 1600 * PMCs that this process is the owner of. 1601 */ 1602 1603 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 1604 pmc_remove_owner(po); 1605 pmc_destroy_owner_descriptor(po); 1606 } 1607 1608 /* 1609 * If the process being exec'ed is not the target of any 1610 * PMC, we are done. 1611 */ 1612 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) { 1613 if (freepath) 1614 FREE(freepath, M_TEMP); 1615 break; 1616 } 1617 1618 /* 1619 * Log the exec event to all monitoring owners. Skip 1620 * owners who have already recieved the event because 1621 * they had system sampling PMCs active. 1622 */ 1623 for (ri = 0; ri < md->pmd_npmc; ri++) 1624 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 1625 po = pm->pm_owner; 1626 if (po->po_sscount == 0 && 1627 po->po_flags & PMC_PO_OWNS_LOGFILE) 1628 pmclog_process_procexec(po, pm->pm_id, 1629 p->p_pid, pk->pm_entryaddr, 1630 fullpath); 1631 } 1632 1633 if (freepath) 1634 FREE(freepath, M_TEMP); 1635 1636 1637 PMCDBG(PRC,EXC,1, "exec proc=%p (%d, %s) cred-changed=%d", 1638 p, p->p_pid, p->p_comm, pk->pm_credentialschanged); 1639 1640 if (pk->pm_credentialschanged == 0) /* no change */ 1641 break; 1642 1643 /* 1644 * If the newly exec()'ed process has a different credential 1645 * than before, allow it to be the target of a PMC only if 1646 * the PMC's owner has sufficient priviledge. 1647 */ 1648 1649 for (ri = 0; ri < md->pmd_npmc; ri++) 1650 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) 1651 if (pmc_can_attach(pm, td->td_proc) != 0) 1652 pmc_detach_one_process(td->td_proc, 1653 pm, PMC_FLAG_NONE); 1654 1655 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt < (int) md->pmd_npmc, 1656 ("[pmc,%d] Illegal ref count %d on pp %p", __LINE__, 1657 pp->pp_refcnt, pp)); 1658 1659 /* 1660 * If this process is no longer the target of any 1661 * PMCs, we can remove the process entry and free 1662 * up space. 1663 */ 1664 1665 if (pp->pp_refcnt == 0) { 1666 pmc_remove_process_descriptor(pp); 1667 FREE(pp, M_PMC); 1668 break; 1669 } 1670 1671 } 1672 break; 1673 1674 case PMC_FN_CSW_IN: 1675 pmc_process_csw_in(td); 1676 break; 1677 1678 case PMC_FN_CSW_OUT: 1679 pmc_process_csw_out(td); 1680 break; 1681 1682 /* 1683 * Process accumulated PC samples. 1684 * 1685 * This function is expected to be called by hardclock() for 1686 * each CPU that has accumulated PC samples. 1687 * 1688 * This function is to be executed on the CPU whose samples 1689 * are being processed. 1690 */ 1691 case PMC_FN_DO_SAMPLES: 1692 1693 /* 1694 * Clear the cpu specific bit in the CPU mask before 1695 * do the rest of the processing. If the NMI handler 1696 * gets invoked after the "atomic_clear_int()" call 1697 * below but before "pmc_process_samples()" gets 1698 * around to processing the interrupt, then we will 1699 * come back here at the next hardclock() tick (and 1700 * may find nothing to do if "pmc_process_samples()" 1701 * had already processed the interrupt). We don't 1702 * lose the interrupt sample. 1703 */ 1704 atomic_clear_int(&pmc_cpumask, (1 << PCPU_GET(cpuid))); 1705 pmc_process_samples(PCPU_GET(cpuid)); 1706 break; 1707 1708 1709 case PMC_FN_KLD_LOAD: 1710 sx_assert(&pmc_sx, SX_LOCKED); 1711 pmc_process_kld_load((struct pmckern_map_in *) arg); 1712 break; 1713 1714 case PMC_FN_KLD_UNLOAD: 1715 sx_assert(&pmc_sx, SX_LOCKED); 1716 pmc_process_kld_unload((struct pmckern_map_out *) arg); 1717 break; 1718 1719 case PMC_FN_MMAP: 1720 sx_assert(&pmc_sx, SX_LOCKED); 1721 pmc_process_mmap(td, (struct pmckern_map_in *) arg); 1722 break; 1723 1724 case PMC_FN_MUNMAP: 1725 sx_assert(&pmc_sx, SX_LOCKED); 1726 pmc_process_munmap(td, (struct pmckern_map_out *) arg); 1727 break; 1728 1729 default: 1730 #ifdef DEBUG 1731 KASSERT(0, ("[pmc,%d] unknown hook %d\n", __LINE__, function)); 1732 #endif 1733 break; 1734 1735 } 1736 1737 return 0; 1738 } 1739 1740 /* 1741 * allocate a 'struct pmc_owner' descriptor in the owner hash table. 1742 */ 1743 1744 static struct pmc_owner * 1745 pmc_allocate_owner_descriptor(struct proc *p) 1746 { 1747 uint32_t hindex; 1748 struct pmc_owner *po; 1749 struct pmc_ownerhash *poh; 1750 1751 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 1752 poh = &pmc_ownerhash[hindex]; 1753 1754 /* allocate space for N pointers and one descriptor struct */ 1755 MALLOC(po, struct pmc_owner *, sizeof(struct pmc_owner), 1756 M_PMC, M_ZERO|M_WAITOK); 1757 1758 po->po_sscount = po->po_error = po->po_flags = 0; 1759 po->po_file = NULL; 1760 po->po_owner = p; 1761 po->po_kthread = NULL; 1762 LIST_INIT(&po->po_pmcs); 1763 LIST_INSERT_HEAD(poh, po, po_next); /* insert into hash table */ 1764 1765 TAILQ_INIT(&po->po_logbuffers); 1766 mtx_init(&po->po_mtx, "pmc-owner-mtx", "pmc-per-proc", MTX_SPIN); 1767 1768 PMCDBG(OWN,ALL,1, "allocate-owner proc=%p (%d, %s) pmc-owner=%p", 1769 p, p->p_pid, p->p_comm, po); 1770 1771 return po; 1772 } 1773 1774 static void 1775 pmc_destroy_owner_descriptor(struct pmc_owner *po) 1776 { 1777 1778 PMCDBG(OWN,REL,1, "destroy-owner po=%p proc=%p (%d, %s)", 1779 po, po->po_owner, po->po_owner->p_pid, po->po_owner->p_comm); 1780 1781 mtx_destroy(&po->po_mtx); 1782 FREE(po, M_PMC); 1783 } 1784 1785 /* 1786 * find the descriptor corresponding to process 'p', adding or removing it 1787 * as specified by 'mode'. 1788 */ 1789 1790 static struct pmc_process * 1791 pmc_find_process_descriptor(struct proc *p, uint32_t mode) 1792 { 1793 uint32_t hindex; 1794 struct pmc_process *pp, *ppnew; 1795 struct pmc_processhash *pph; 1796 1797 hindex = PMC_HASH_PTR(p, pmc_processhashmask); 1798 pph = &pmc_processhash[hindex]; 1799 1800 ppnew = NULL; 1801 1802 /* 1803 * Pre-allocate memory in the FIND_ALLOCATE case since we 1804 * cannot call malloc(9) once we hold a spin lock. 1805 */ 1806 1807 if (mode & PMC_FLAG_ALLOCATE) { 1808 /* allocate additional space for 'n' pmc pointers */ 1809 MALLOC(ppnew, struct pmc_process *, 1810 sizeof(struct pmc_process) + md->pmd_npmc * 1811 sizeof(struct pmc_targetstate), M_PMC, M_ZERO|M_WAITOK); 1812 } 1813 1814 mtx_lock_spin(&pmc_processhash_mtx); 1815 LIST_FOREACH(pp, pph, pp_next) 1816 if (pp->pp_proc == p) 1817 break; 1818 1819 if ((mode & PMC_FLAG_REMOVE) && pp != NULL) 1820 LIST_REMOVE(pp, pp_next); 1821 1822 if ((mode & PMC_FLAG_ALLOCATE) && pp == NULL && 1823 ppnew != NULL) { 1824 ppnew->pp_proc = p; 1825 LIST_INSERT_HEAD(pph, ppnew, pp_next); 1826 pp = ppnew; 1827 ppnew = NULL; 1828 } 1829 mtx_unlock_spin(&pmc_processhash_mtx); 1830 1831 if (pp != NULL && ppnew != NULL) 1832 FREE(ppnew, M_PMC); 1833 1834 return pp; 1835 } 1836 1837 /* 1838 * remove a process descriptor from the process hash table. 1839 */ 1840 1841 static void 1842 pmc_remove_process_descriptor(struct pmc_process *pp) 1843 { 1844 KASSERT(pp->pp_refcnt == 0, 1845 ("[pmc,%d] Removing process descriptor %p with count %d", 1846 __LINE__, pp, pp->pp_refcnt)); 1847 1848 mtx_lock_spin(&pmc_processhash_mtx); 1849 LIST_REMOVE(pp, pp_next); 1850 mtx_unlock_spin(&pmc_processhash_mtx); 1851 } 1852 1853 1854 /* 1855 * find an owner descriptor corresponding to proc 'p' 1856 */ 1857 1858 static struct pmc_owner * 1859 pmc_find_owner_descriptor(struct proc *p) 1860 { 1861 uint32_t hindex; 1862 struct pmc_owner *po; 1863 struct pmc_ownerhash *poh; 1864 1865 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 1866 poh = &pmc_ownerhash[hindex]; 1867 1868 po = NULL; 1869 LIST_FOREACH(po, poh, po_next) 1870 if (po->po_owner == p) 1871 break; 1872 1873 PMCDBG(OWN,FND,1, "find-owner proc=%p (%d, %s) hindex=0x%x -> " 1874 "pmc-owner=%p", p, p->p_pid, p->p_comm, hindex, po); 1875 1876 return po; 1877 } 1878 1879 /* 1880 * pmc_allocate_pmc_descriptor 1881 * 1882 * Allocate a pmc descriptor and initialize its 1883 * fields. 1884 */ 1885 1886 static struct pmc * 1887 pmc_allocate_pmc_descriptor(void) 1888 { 1889 struct pmc *pmc; 1890 1891 MALLOC(pmc, struct pmc *, sizeof(struct pmc), M_PMC, M_ZERO|M_WAITOK); 1892 1893 if (pmc != NULL) { 1894 pmc->pm_owner = NULL; 1895 LIST_INIT(&pmc->pm_targets); 1896 } 1897 1898 PMCDBG(PMC,ALL,1, "allocate-pmc -> pmc=%p", pmc); 1899 1900 return pmc; 1901 } 1902 1903 /* 1904 * Destroy a pmc descriptor. 1905 */ 1906 1907 static void 1908 pmc_destroy_pmc_descriptor(struct pmc *pm) 1909 { 1910 (void) pm; 1911 1912 #ifdef DEBUG 1913 KASSERT(pm->pm_state == PMC_STATE_DELETED || 1914 pm->pm_state == PMC_STATE_FREE, 1915 ("[pmc,%d] destroying non-deleted PMC", __LINE__)); 1916 KASSERT(LIST_EMPTY(&pm->pm_targets), 1917 ("[pmc,%d] destroying pmc with targets", __LINE__)); 1918 KASSERT(pm->pm_owner == NULL, 1919 ("[pmc,%d] destroying pmc attached to an owner", __LINE__)); 1920 KASSERT(pm->pm_runcount == 0, 1921 ("[pmc,%d] pmc has non-zero run count %d", __LINE__, 1922 pm->pm_runcount)); 1923 #endif 1924 } 1925 1926 static void 1927 pmc_wait_for_pmc_idle(struct pmc *pm) 1928 { 1929 #ifdef DEBUG 1930 volatile int maxloop; 1931 1932 maxloop = 100 * mp_ncpus; 1933 #endif 1934 1935 /* 1936 * Loop (with a forced context switch) till the PMC's runcount 1937 * comes down to zero. 1938 */ 1939 while (atomic_load_acq_32(&pm->pm_runcount) > 0) { 1940 #ifdef DEBUG 1941 maxloop--; 1942 KASSERT(maxloop > 0, 1943 ("[pmc,%d] (ri%d, rc%d) waiting too long for " 1944 "pmc to be free", __LINE__, 1945 PMC_TO_ROWINDEX(pm), pm->pm_runcount)); 1946 #endif 1947 pmc_force_context_switch(); 1948 } 1949 } 1950 1951 /* 1952 * This function does the following things: 1953 * 1954 * - detaches the PMC from hardware 1955 * - unlinks all target threads that were attached to it 1956 * - removes the PMC from its owner's list 1957 * - destroy's the PMC private mutex 1958 * 1959 * Once this function completes, the given pmc pointer can be safely 1960 * FREE'd by the caller. 1961 */ 1962 1963 static void 1964 pmc_release_pmc_descriptor(struct pmc *pm) 1965 { 1966 u_int ri, cpu; 1967 enum pmc_mode mode; 1968 struct pmc_hw *phw; 1969 struct pmc_owner *po; 1970 struct pmc_process *pp; 1971 struct pmc_target *ptgt, *tmp; 1972 struct pmc_binding pb; 1973 1974 sx_assert(&pmc_sx, SX_XLOCKED); 1975 1976 KASSERT(pm, ("[pmc,%d] null pmc", __LINE__)); 1977 1978 ri = PMC_TO_ROWINDEX(pm); 1979 mode = PMC_TO_MODE(pm); 1980 1981 PMCDBG(PMC,REL,1, "release-pmc pmc=%p ri=%d mode=%d", pm, ri, 1982 mode); 1983 1984 /* 1985 * First, we take the PMC off hardware. 1986 */ 1987 cpu = 0; 1988 if (PMC_IS_SYSTEM_MODE(mode)) { 1989 1990 /* 1991 * A system mode PMC runs on a specific CPU. Switch 1992 * to this CPU and turn hardware off. 1993 */ 1994 pmc_save_cpu_binding(&pb); 1995 1996 cpu = PMC_TO_CPU(pm); 1997 1998 pmc_select_cpu(cpu); 1999 2000 /* switch off non-stalled CPUs */ 2001 if (pm->pm_state == PMC_STATE_RUNNING && 2002 pm->pm_stalled == 0) { 2003 2004 phw = pmc_pcpu[cpu]->pc_hwpmcs[ri]; 2005 2006 KASSERT(phw->phw_pmc == pm, 2007 ("[pmc, %d] pmc ptr ri(%d) hw(%p) pm(%p)", 2008 __LINE__, ri, phw->phw_pmc, pm)); 2009 PMCDBG(PMC,REL,2, "stopping cpu=%d ri=%d", cpu, ri); 2010 2011 critical_enter(); 2012 md->pmd_stop_pmc(cpu, ri); 2013 critical_exit(); 2014 } 2015 2016 PMCDBG(PMC,REL,2, "decfg cpu=%d ri=%d", cpu, ri); 2017 2018 critical_enter(); 2019 md->pmd_config_pmc(cpu, ri, NULL); 2020 critical_exit(); 2021 2022 /* adjust the global and process count of SS mode PMCs */ 2023 if (mode == PMC_MODE_SS && pm->pm_state == PMC_STATE_RUNNING) { 2024 po = pm->pm_owner; 2025 po->po_sscount--; 2026 if (po->po_sscount == 0) { 2027 atomic_subtract_rel_int(&pmc_ss_count, 1); 2028 LIST_REMOVE(po, po_ssnext); 2029 } 2030 } 2031 2032 pm->pm_state = PMC_STATE_DELETED; 2033 2034 pmc_restore_cpu_binding(&pb); 2035 2036 /* 2037 * We could have references to this PMC structure in 2038 * the per-cpu sample queues. Wait for the queue to 2039 * drain. 2040 */ 2041 pmc_wait_for_pmc_idle(pm); 2042 2043 } else if (PMC_IS_VIRTUAL_MODE(mode)) { 2044 2045 /* 2046 * A virtual PMC could be running on multiple CPUs at 2047 * a given instant. 2048 * 2049 * By marking its state as DELETED, we ensure that 2050 * this PMC is never further scheduled on hardware. 2051 * 2052 * Then we wait till all CPUs are done with this PMC. 2053 */ 2054 pm->pm_state = PMC_STATE_DELETED; 2055 2056 2057 /* Wait for the PMCs runcount to come to zero. */ 2058 pmc_wait_for_pmc_idle(pm); 2059 2060 /* 2061 * At this point the PMC is off all CPUs and cannot be 2062 * freshly scheduled onto a CPU. It is now safe to 2063 * unlink all targets from this PMC. If a 2064 * process-record's refcount falls to zero, we remove 2065 * it from the hash table. The module-wide SX lock 2066 * protects us from races. 2067 */ 2068 LIST_FOREACH_SAFE(ptgt, &pm->pm_targets, pt_next, tmp) { 2069 pp = ptgt->pt_process; 2070 pmc_unlink_target_process(pm, pp); /* frees 'ptgt' */ 2071 2072 PMCDBG(PMC,REL,3, "pp->refcnt=%d", pp->pp_refcnt); 2073 2074 /* 2075 * If the target process record shows that no 2076 * PMCs are attached to it, reclaim its space. 2077 */ 2078 2079 if (pp->pp_refcnt == 0) { 2080 pmc_remove_process_descriptor(pp); 2081 FREE(pp, M_PMC); 2082 } 2083 } 2084 2085 cpu = curthread->td_oncpu; /* setup cpu for pmd_release() */ 2086 2087 } 2088 2089 /* 2090 * Release any MD resources 2091 */ 2092 2093 (void) md->pmd_release_pmc(cpu, ri, pm); 2094 2095 /* 2096 * Update row disposition 2097 */ 2098 2099 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) 2100 PMC_UNMARK_ROW_STANDALONE(ri); 2101 else 2102 PMC_UNMARK_ROW_THREAD(ri); 2103 2104 /* unlink from the owner's list */ 2105 if (pm->pm_owner) { 2106 LIST_REMOVE(pm, pm_next); 2107 pm->pm_owner = NULL; 2108 } 2109 2110 pmc_destroy_pmc_descriptor(pm); 2111 } 2112 2113 /* 2114 * Register an owner and a pmc. 2115 */ 2116 2117 static int 2118 pmc_register_owner(struct proc *p, struct pmc *pmc) 2119 { 2120 struct pmc_owner *po; 2121 2122 sx_assert(&pmc_sx, SX_XLOCKED); 2123 2124 if ((po = pmc_find_owner_descriptor(p)) == NULL) 2125 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) 2126 return ENOMEM; 2127 2128 KASSERT(pmc->pm_owner == NULL, 2129 ("[pmc,%d] attempting to own an initialized PMC", __LINE__)); 2130 pmc->pm_owner = po; 2131 2132 LIST_INSERT_HEAD(&po->po_pmcs, pmc, pm_next); 2133 2134 PROC_LOCK(p); 2135 p->p_flag |= P_HWPMC; 2136 PROC_UNLOCK(p); 2137 2138 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 2139 pmclog_process_pmcallocate(pmc); 2140 2141 PMCDBG(PMC,REG,1, "register-owner pmc-owner=%p pmc=%p", 2142 po, pmc); 2143 2144 return 0; 2145 } 2146 2147 /* 2148 * Return the current row disposition: 2149 * == 0 => FREE 2150 * > 0 => PROCESS MODE 2151 * < 0 => SYSTEM MODE 2152 */ 2153 2154 int 2155 pmc_getrowdisp(int ri) 2156 { 2157 return pmc_pmcdisp[ri]; 2158 } 2159 2160 /* 2161 * Check if a PMC at row index 'ri' can be allocated to the current 2162 * process. 2163 * 2164 * Allocation can fail if: 2165 * - the current process is already being profiled by a PMC at index 'ri', 2166 * attached to it via OP_PMCATTACH. 2167 * - the current process has already allocated a PMC at index 'ri' 2168 * via OP_ALLOCATE. 2169 */ 2170 2171 static int 2172 pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, int cpu) 2173 { 2174 enum pmc_mode mode; 2175 struct pmc *pm; 2176 struct pmc_owner *po; 2177 struct pmc_process *pp; 2178 2179 PMCDBG(PMC,ALR,1, "can-allocate-rowindex proc=%p (%d, %s) ri=%d " 2180 "cpu=%d", p, p->p_pid, p->p_comm, ri, cpu); 2181 2182 /* 2183 * We shouldn't have already allocated a process-mode PMC at 2184 * row index 'ri'. 2185 * 2186 * We shouldn't have allocated a system-wide PMC on the same 2187 * CPU and same RI. 2188 */ 2189 if ((po = pmc_find_owner_descriptor(p)) != NULL) 2190 LIST_FOREACH(pm, &po->po_pmcs, pm_next) { 2191 if (PMC_TO_ROWINDEX(pm) == ri) { 2192 mode = PMC_TO_MODE(pm); 2193 if (PMC_IS_VIRTUAL_MODE(mode)) 2194 return EEXIST; 2195 if (PMC_IS_SYSTEM_MODE(mode) && 2196 (int) PMC_TO_CPU(pm) == cpu) 2197 return EEXIST; 2198 } 2199 } 2200 2201 /* 2202 * We also shouldn't be the target of any PMC at this index 2203 * since otherwise a PMC_ATTACH to ourselves will fail. 2204 */ 2205 if ((pp = pmc_find_process_descriptor(p, 0)) != NULL) 2206 if (pp->pp_pmcs[ri].pp_pmc) 2207 return EEXIST; 2208 2209 PMCDBG(PMC,ALR,2, "can-allocate-rowindex proc=%p (%d, %s) ri=%d ok", 2210 p, p->p_pid, p->p_comm, ri); 2211 2212 return 0; 2213 } 2214 2215 /* 2216 * Check if a given PMC at row index 'ri' can be currently used in 2217 * mode 'mode'. 2218 */ 2219 2220 static int 2221 pmc_can_allocate_row(int ri, enum pmc_mode mode) 2222 { 2223 enum pmc_disp disp; 2224 2225 sx_assert(&pmc_sx, SX_XLOCKED); 2226 2227 PMCDBG(PMC,ALR,1, "can-allocate-row ri=%d mode=%d", ri, mode); 2228 2229 if (PMC_IS_SYSTEM_MODE(mode)) 2230 disp = PMC_DISP_STANDALONE; 2231 else 2232 disp = PMC_DISP_THREAD; 2233 2234 /* 2235 * check disposition for PMC row 'ri': 2236 * 2237 * Expected disposition Row-disposition Result 2238 * 2239 * STANDALONE STANDALONE or FREE proceed 2240 * STANDALONE THREAD fail 2241 * THREAD THREAD or FREE proceed 2242 * THREAD STANDALONE fail 2243 */ 2244 2245 if (!PMC_ROW_DISP_IS_FREE(ri) && 2246 !(disp == PMC_DISP_THREAD && PMC_ROW_DISP_IS_THREAD(ri)) && 2247 !(disp == PMC_DISP_STANDALONE && PMC_ROW_DISP_IS_STANDALONE(ri))) 2248 return EBUSY; 2249 2250 /* 2251 * All OK 2252 */ 2253 2254 PMCDBG(PMC,ALR,2, "can-allocate-row ri=%d mode=%d ok", ri, mode); 2255 2256 return 0; 2257 2258 } 2259 2260 /* 2261 * Find a PMC descriptor with user handle 'pmcid' for thread 'td'. 2262 */ 2263 2264 static struct pmc * 2265 pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, pmc_id_t pmcid) 2266 { 2267 struct pmc *pm; 2268 2269 KASSERT(PMC_ID_TO_ROWINDEX(pmcid) < md->pmd_npmc, 2270 ("[pmc,%d] Illegal pmc index %d (max %d)", __LINE__, 2271 PMC_ID_TO_ROWINDEX(pmcid), md->pmd_npmc)); 2272 2273 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 2274 if (pm->pm_id == pmcid) 2275 return pm; 2276 2277 return NULL; 2278 } 2279 2280 static int 2281 pmc_find_pmc(pmc_id_t pmcid, struct pmc **pmc) 2282 { 2283 2284 struct pmc *pm; 2285 struct pmc_owner *po; 2286 2287 PMCDBG(PMC,FND,1, "find-pmc id=%d", pmcid); 2288 2289 if ((po = pmc_find_owner_descriptor(curthread->td_proc)) == NULL) 2290 return ESRCH; 2291 2292 if ((pm = pmc_find_pmc_descriptor_in_process(po, pmcid)) == NULL) 2293 return EINVAL; 2294 2295 PMCDBG(PMC,FND,2, "find-pmc id=%d -> pmc=%p", pmcid, pm); 2296 2297 *pmc = pm; 2298 return 0; 2299 } 2300 2301 /* 2302 * Start a PMC. 2303 */ 2304 2305 static int 2306 pmc_start(struct pmc *pm) 2307 { 2308 int error, cpu, ri; 2309 enum pmc_mode mode; 2310 struct pmc_owner *po; 2311 struct pmc_binding pb; 2312 2313 KASSERT(pm != NULL, 2314 ("[pmc,%d] null pm", __LINE__)); 2315 2316 mode = PMC_TO_MODE(pm); 2317 ri = PMC_TO_ROWINDEX(pm); 2318 error = 0; 2319 2320 PMCDBG(PMC,OPS,1, "start pmc=%p mode=%d ri=%d", pm, mode, ri); 2321 2322 po = pm->pm_owner; 2323 2324 if (PMC_IS_VIRTUAL_MODE(mode)) { 2325 2326 /* 2327 * If a PMCATTACH has never been done on this PMC, 2328 * attach it to its owner process. 2329 */ 2330 2331 if (LIST_EMPTY(&pm->pm_targets)) 2332 error = (pm->pm_flags & PMC_F_ATTACH_DONE) ? ESRCH : 2333 pmc_attach_process(po->po_owner, pm); 2334 2335 /* 2336 * Disallow PMCSTART if a logfile is required but has not 2337 * been configured yet. 2338 */ 2339 2340 if (error == 0 && (pm->pm_flags & PMC_F_NEEDS_LOGFILE) && 2341 (po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) 2342 error = EDOOFUS; 2343 2344 /* 2345 * If the PMC is attached to its owner, then force a context 2346 * switch to ensure that the MD state gets set correctly. 2347 */ 2348 2349 if (error == 0) { 2350 pm->pm_state = PMC_STATE_RUNNING; 2351 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) 2352 pmc_force_context_switch(); 2353 } 2354 2355 return error; 2356 } 2357 2358 2359 /* 2360 * A system-wide PMC. 2361 */ 2362 2363 if ((pm->pm_flags & PMC_F_NEEDS_LOGFILE) && 2364 (po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) 2365 return EDOOFUS; /* programming error */ 2366 2367 /* 2368 * Add the owner to the global list if this is a system-wide 2369 * sampling PMC. 2370 */ 2371 2372 if (mode == PMC_MODE_SS) { 2373 if (po->po_sscount == 0) { 2374 LIST_INSERT_HEAD(&pmc_ss_owners, po, po_ssnext); 2375 atomic_add_rel_int(&pmc_ss_count, 1); 2376 PMCDBG(PMC,OPS,1, "po=%p in global list", po); 2377 } 2378 po->po_sscount++; 2379 } 2380 2381 /* TODO: dump system wide process mappings to the log? */ 2382 2383 /* 2384 * Move to the CPU associated with this 2385 * PMC, and start the hardware. 2386 */ 2387 2388 pmc_save_cpu_binding(&pb); 2389 2390 cpu = PMC_TO_CPU(pm); 2391 2392 if (pmc_cpu_is_disabled(cpu)) 2393 return ENXIO; 2394 2395 pmc_select_cpu(cpu); 2396 2397 /* 2398 * global PMCs are configured at allocation time 2399 * so write out the initial value and start the PMC. 2400 */ 2401 2402 pm->pm_state = PMC_STATE_RUNNING; 2403 2404 critical_enter(); 2405 if ((error = md->pmd_write_pmc(cpu, ri, 2406 PMC_IS_SAMPLING_MODE(mode) ? 2407 pm->pm_sc.pm_reloadcount : 2408 pm->pm_sc.pm_initial)) == 0) 2409 error = md->pmd_start_pmc(cpu, ri); 2410 critical_exit(); 2411 2412 pmc_restore_cpu_binding(&pb); 2413 2414 return error; 2415 } 2416 2417 /* 2418 * Stop a PMC. 2419 */ 2420 2421 static int 2422 pmc_stop(struct pmc *pm) 2423 { 2424 int cpu, error, ri; 2425 struct pmc_owner *po; 2426 struct pmc_binding pb; 2427 2428 KASSERT(pm != NULL, ("[pmc,%d] null pmc", __LINE__)); 2429 2430 PMCDBG(PMC,OPS,1, "stop pmc=%p mode=%d ri=%d", pm, 2431 PMC_TO_MODE(pm), PMC_TO_ROWINDEX(pm)); 2432 2433 pm->pm_state = PMC_STATE_STOPPED; 2434 2435 /* 2436 * If the PMC is a virtual mode one, changing the state to 2437 * non-RUNNING is enough to ensure that the PMC never gets 2438 * scheduled. 2439 * 2440 * If this PMC is current running on a CPU, then it will 2441 * handled correctly at the time its target process is context 2442 * switched out. 2443 */ 2444 2445 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 2446 return 0; 2447 2448 /* 2449 * A system-mode PMC. Move to the CPU associated with 2450 * this PMC, and stop the hardware. We update the 2451 * 'initial count' so that a subsequent PMCSTART will 2452 * resume counting from the current hardware count. 2453 */ 2454 2455 pmc_save_cpu_binding(&pb); 2456 2457 cpu = PMC_TO_CPU(pm); 2458 2459 KASSERT(cpu >= 0 && cpu < mp_ncpus, 2460 ("[pmc,%d] illegal cpu=%d", __LINE__, cpu)); 2461 2462 if (pmc_cpu_is_disabled(cpu)) 2463 return ENXIO; 2464 2465 pmc_select_cpu(cpu); 2466 2467 ri = PMC_TO_ROWINDEX(pm); 2468 2469 critical_enter(); 2470 if ((error = md->pmd_stop_pmc(cpu, ri)) == 0) 2471 error = md->pmd_read_pmc(cpu, ri, &pm->pm_sc.pm_initial); 2472 critical_exit(); 2473 2474 pmc_restore_cpu_binding(&pb); 2475 2476 po = pm->pm_owner; 2477 2478 /* remove this owner from the global list of SS PMC owners */ 2479 if (PMC_TO_MODE(pm) == PMC_MODE_SS) { 2480 po->po_sscount--; 2481 if (po->po_sscount == 0) { 2482 atomic_subtract_rel_int(&pmc_ss_count, 1); 2483 LIST_REMOVE(po, po_ssnext); 2484 PMCDBG(PMC,OPS,2,"po=%p removed from global list", po); 2485 } 2486 } 2487 2488 return error; 2489 } 2490 2491 2492 #ifdef DEBUG 2493 static const char *pmc_op_to_name[] = { 2494 #undef __PMC_OP 2495 #define __PMC_OP(N, D) #N , 2496 __PMC_OPS() 2497 NULL 2498 }; 2499 #endif 2500 2501 /* 2502 * The syscall interface 2503 */ 2504 2505 #define PMC_GET_SX_XLOCK(...) do { \ 2506 sx_xlock(&pmc_sx); \ 2507 if (pmc_hook == NULL) { \ 2508 sx_xunlock(&pmc_sx); \ 2509 return __VA_ARGS__; \ 2510 } \ 2511 } while (0) 2512 2513 #define PMC_DOWNGRADE_SX() do { \ 2514 sx_downgrade(&pmc_sx); \ 2515 is_sx_downgraded = 1; \ 2516 } while (0) 2517 2518 static int 2519 pmc_syscall_handler(struct thread *td, void *syscall_args) 2520 { 2521 int error, is_sx_downgraded, op; 2522 struct pmc_syscall_args *c; 2523 void *arg; 2524 2525 PMC_GET_SX_XLOCK(ENOSYS); 2526 2527 DROP_GIANT(); 2528 2529 is_sx_downgraded = 0; 2530 2531 c = (struct pmc_syscall_args *) syscall_args; 2532 2533 op = c->pmop_code; 2534 arg = c->pmop_data; 2535 2536 PMCDBG(MOD,PMS,1, "syscall op=%d \"%s\" arg=%p", op, 2537 pmc_op_to_name[op], arg); 2538 2539 error = 0; 2540 atomic_add_int(&pmc_stats.pm_syscalls, 1); 2541 2542 switch(op) 2543 { 2544 2545 2546 /* 2547 * Configure a log file. 2548 * 2549 * XXX This OP will be reworked. 2550 */ 2551 2552 case PMC_OP_CONFIGURELOG: 2553 { 2554 struct proc *p; 2555 struct pmc *pm; 2556 struct pmc_owner *po; 2557 struct pmckern_map_in *km, *kmbase; 2558 struct pmc_op_configurelog cl; 2559 2560 sx_assert(&pmc_sx, SX_XLOCKED); 2561 2562 if ((error = copyin(arg, &cl, sizeof(cl))) != 0) 2563 break; 2564 2565 /* mark this process as owning a log file */ 2566 p = td->td_proc; 2567 if ((po = pmc_find_owner_descriptor(p)) == NULL) 2568 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) { 2569 error = ENOMEM; 2570 break; 2571 } 2572 2573 /* 2574 * If a valid fd was passed in, try to configure that, 2575 * otherwise if 'fd' was less than zero and there was 2576 * a log file configured, flush its buffers and 2577 * de-configure it. 2578 */ 2579 if (cl.pm_logfd >= 0) 2580 error = pmclog_configure_log(po, cl.pm_logfd); 2581 else if (po->po_flags & PMC_PO_OWNS_LOGFILE) { 2582 pmclog_process_closelog(po); 2583 error = pmclog_flush(po); 2584 if (error == 0) { 2585 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 2586 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 2587 pm->pm_state == PMC_STATE_RUNNING) 2588 pmc_stop(pm); 2589 error = pmclog_deconfigure_log(po); 2590 } 2591 } else 2592 error = EINVAL; 2593 2594 if (error) 2595 break; 2596 2597 /* 2598 * Log the current set of kernel modules. 2599 */ 2600 kmbase = linker_hwpmc_list_objects(); 2601 for (km = kmbase; km->pm_file != NULL; km++) { 2602 PMCDBG(LOG,REG,1,"%s %p", (char *) km->pm_file, 2603 (void *) km->pm_address); 2604 pmclog_process_map_in(po, (pid_t) -1, km->pm_address, 2605 km->pm_file); 2606 } 2607 FREE(kmbase, M_LINKER); 2608 } 2609 break; 2610 2611 2612 /* 2613 * Flush a log file. 2614 */ 2615 2616 case PMC_OP_FLUSHLOG: 2617 { 2618 struct pmc_owner *po; 2619 2620 sx_assert(&pmc_sx, SX_XLOCKED); 2621 2622 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 2623 error = EINVAL; 2624 break; 2625 } 2626 2627 error = pmclog_flush(po); 2628 } 2629 break; 2630 2631 /* 2632 * Retrieve hardware configuration. 2633 */ 2634 2635 case PMC_OP_GETCPUINFO: /* CPU information */ 2636 { 2637 struct pmc_op_getcpuinfo gci; 2638 2639 gci.pm_cputype = md->pmd_cputype; 2640 gci.pm_ncpu = mp_ncpus; 2641 gci.pm_npmc = md->pmd_npmc; 2642 gci.pm_nclass = md->pmd_nclass; 2643 bcopy(md->pmd_classes, &gci.pm_classes, 2644 sizeof(gci.pm_classes)); 2645 error = copyout(&gci, arg, sizeof(gci)); 2646 } 2647 break; 2648 2649 2650 /* 2651 * Get module statistics 2652 */ 2653 2654 case PMC_OP_GETDRIVERSTATS: 2655 { 2656 struct pmc_op_getdriverstats gms; 2657 2658 bcopy(&pmc_stats, &gms, sizeof(gms)); 2659 error = copyout(&gms, arg, sizeof(gms)); 2660 } 2661 break; 2662 2663 2664 /* 2665 * Retrieve module version number 2666 */ 2667 2668 case PMC_OP_GETMODULEVERSION: 2669 { 2670 uint32_t cv, modv; 2671 2672 /* retrieve the client's idea of the ABI version */ 2673 if ((error = copyin(arg, &cv, sizeof(uint32_t))) != 0) 2674 break; 2675 /* don't service clients newer than our driver */ 2676 modv = PMC_VERSION; 2677 if ((cv & 0xFFFF0000) > (modv & 0xFFFF0000)) { 2678 error = EPROGMISMATCH; 2679 break; 2680 } 2681 error = copyout(&modv, arg, sizeof(int)); 2682 } 2683 break; 2684 2685 2686 /* 2687 * Retrieve the state of all the PMCs on a given 2688 * CPU. 2689 */ 2690 2691 case PMC_OP_GETPMCINFO: 2692 { 2693 uint32_t cpu, n, npmc; 2694 size_t pmcinfo_size; 2695 struct pmc *pm; 2696 struct pmc_info *p, *pmcinfo; 2697 struct pmc_op_getpmcinfo *gpi; 2698 struct pmc_owner *po; 2699 struct pmc_binding pb; 2700 2701 PMC_DOWNGRADE_SX(); 2702 2703 gpi = (struct pmc_op_getpmcinfo *) arg; 2704 2705 if ((error = copyin(&gpi->pm_cpu, &cpu, sizeof(cpu))) != 0) 2706 break; 2707 2708 if (cpu >= (unsigned int) mp_ncpus) { 2709 error = EINVAL; 2710 break; 2711 } 2712 2713 if (pmc_cpu_is_disabled(cpu)) { 2714 error = ENXIO; 2715 break; 2716 } 2717 2718 /* switch to CPU 'cpu' */ 2719 pmc_save_cpu_binding(&pb); 2720 pmc_select_cpu(cpu); 2721 2722 npmc = md->pmd_npmc; 2723 2724 pmcinfo_size = npmc * sizeof(struct pmc_info); 2725 MALLOC(pmcinfo, struct pmc_info *, pmcinfo_size, M_PMC, 2726 M_WAITOK); 2727 2728 p = pmcinfo; 2729 2730 for (n = 0; n < md->pmd_npmc; n++, p++) { 2731 2732 if ((error = md->pmd_describe(cpu, n, p, &pm)) != 0) 2733 break; 2734 2735 if (PMC_ROW_DISP_IS_STANDALONE(n)) 2736 p->pm_rowdisp = PMC_DISP_STANDALONE; 2737 else if (PMC_ROW_DISP_IS_THREAD(n)) 2738 p->pm_rowdisp = PMC_DISP_THREAD; 2739 else 2740 p->pm_rowdisp = PMC_DISP_FREE; 2741 2742 p->pm_ownerpid = -1; 2743 2744 if (pm == NULL) /* no PMC associated */ 2745 continue; 2746 2747 po = pm->pm_owner; 2748 2749 KASSERT(po->po_owner != NULL, 2750 ("[pmc,%d] pmc_owner had a null proc pointer", 2751 __LINE__)); 2752 2753 p->pm_ownerpid = po->po_owner->p_pid; 2754 p->pm_mode = PMC_TO_MODE(pm); 2755 p->pm_event = pm->pm_event; 2756 p->pm_flags = pm->pm_flags; 2757 2758 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 2759 p->pm_reloadcount = 2760 pm->pm_sc.pm_reloadcount; 2761 } 2762 2763 pmc_restore_cpu_binding(&pb); 2764 2765 /* now copy out the PMC info collected */ 2766 if (error == 0) 2767 error = copyout(pmcinfo, &gpi->pm_pmcs, pmcinfo_size); 2768 2769 FREE(pmcinfo, M_PMC); 2770 } 2771 break; 2772 2773 2774 /* 2775 * Set the administrative state of a PMC. I.e. whether 2776 * the PMC is to be used or not. 2777 */ 2778 2779 case PMC_OP_PMCADMIN: 2780 { 2781 int cpu, ri; 2782 enum pmc_state request; 2783 struct pmc_cpu *pc; 2784 struct pmc_hw *phw; 2785 struct pmc_op_pmcadmin pma; 2786 struct pmc_binding pb; 2787 2788 sx_assert(&pmc_sx, SX_XLOCKED); 2789 2790 KASSERT(td == curthread, 2791 ("[pmc,%d] td != curthread", __LINE__)); 2792 2793 error = priv_check(td, PRIV_PMC_MANAGE); 2794 if (error) 2795 break; 2796 2797 if ((error = copyin(arg, &pma, sizeof(pma))) != 0) 2798 break; 2799 2800 cpu = pma.pm_cpu; 2801 2802 if (cpu < 0 || cpu >= mp_ncpus) { 2803 error = EINVAL; 2804 break; 2805 } 2806 2807 if (pmc_cpu_is_disabled(cpu)) { 2808 error = ENXIO; 2809 break; 2810 } 2811 2812 request = pma.pm_state; 2813 2814 if (request != PMC_STATE_DISABLED && 2815 request != PMC_STATE_FREE) { 2816 error = EINVAL; 2817 break; 2818 } 2819 2820 ri = pma.pm_pmc; /* pmc id == row index */ 2821 if (ri < 0 || ri >= (int) md->pmd_npmc) { 2822 error = EINVAL; 2823 break; 2824 } 2825 2826 /* 2827 * We can't disable a PMC with a row-index allocated 2828 * for process virtual PMCs. 2829 */ 2830 2831 if (PMC_ROW_DISP_IS_THREAD(ri) && 2832 request == PMC_STATE_DISABLED) { 2833 error = EBUSY; 2834 break; 2835 } 2836 2837 /* 2838 * otherwise, this PMC on this CPU is either free or 2839 * in system-wide mode. 2840 */ 2841 2842 pmc_save_cpu_binding(&pb); 2843 pmc_select_cpu(cpu); 2844 2845 pc = pmc_pcpu[cpu]; 2846 phw = pc->pc_hwpmcs[ri]; 2847 2848 /* 2849 * XXX do we need some kind of 'forced' disable? 2850 */ 2851 2852 if (phw->phw_pmc == NULL) { 2853 if (request == PMC_STATE_DISABLED && 2854 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED)) { 2855 phw->phw_state &= ~PMC_PHW_FLAG_IS_ENABLED; 2856 PMC_MARK_ROW_STANDALONE(ri); 2857 } else if (request == PMC_STATE_FREE && 2858 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0) { 2859 phw->phw_state |= PMC_PHW_FLAG_IS_ENABLED; 2860 PMC_UNMARK_ROW_STANDALONE(ri); 2861 } 2862 /* other cases are a no-op */ 2863 } else 2864 error = EBUSY; 2865 2866 pmc_restore_cpu_binding(&pb); 2867 } 2868 break; 2869 2870 2871 /* 2872 * Allocate a PMC. 2873 */ 2874 2875 case PMC_OP_PMCALLOCATE: 2876 { 2877 uint32_t caps; 2878 u_int cpu; 2879 int n; 2880 enum pmc_mode mode; 2881 struct pmc *pmc; 2882 struct pmc_hw *phw; 2883 struct pmc_op_pmcallocate pa; 2884 struct pmc_binding pb; 2885 2886 if ((error = copyin(arg, &pa, sizeof(pa))) != 0) 2887 break; 2888 2889 caps = pa.pm_caps; 2890 mode = pa.pm_mode; 2891 cpu = pa.pm_cpu; 2892 2893 if ((mode != PMC_MODE_SS && mode != PMC_MODE_SC && 2894 mode != PMC_MODE_TS && mode != PMC_MODE_TC) || 2895 (cpu != (u_int) PMC_CPU_ANY && cpu >= (u_int) mp_ncpus)) { 2896 error = EINVAL; 2897 break; 2898 } 2899 2900 /* 2901 * Virtual PMCs should only ask for a default CPU. 2902 * System mode PMCs need to specify a non-default CPU. 2903 */ 2904 2905 if ((PMC_IS_VIRTUAL_MODE(mode) && cpu != (u_int) PMC_CPU_ANY) || 2906 (PMC_IS_SYSTEM_MODE(mode) && cpu == (u_int) PMC_CPU_ANY)) { 2907 error = EINVAL; 2908 break; 2909 } 2910 2911 /* 2912 * Check that a disabled CPU is not being asked for. 2913 */ 2914 2915 if (PMC_IS_SYSTEM_MODE(mode) && pmc_cpu_is_disabled(cpu)) { 2916 error = ENXIO; 2917 break; 2918 } 2919 2920 /* 2921 * Refuse an allocation for a system-wide PMC if this 2922 * process has been jailed, or if this process lacks 2923 * super-user credentials and the sysctl tunable 2924 * 'security.bsd.unprivileged_syspmcs' is zero. 2925 */ 2926 2927 if (PMC_IS_SYSTEM_MODE(mode)) { 2928 if (jailed(curthread->td_ucred)) { 2929 error = EPERM; 2930 break; 2931 } 2932 if (!pmc_unprivileged_syspmcs) { 2933 error = priv_check(curthread, 2934 PRIV_PMC_SYSTEM); 2935 if (error) 2936 break; 2937 } 2938 } 2939 2940 if (error) 2941 break; 2942 2943 /* 2944 * Look for valid values for 'pm_flags' 2945 */ 2946 2947 if ((pa.pm_flags & ~(PMC_F_DESCENDANTS | PMC_F_LOG_PROCCSW | 2948 PMC_F_LOG_PROCEXIT)) != 0) { 2949 error = EINVAL; 2950 break; 2951 } 2952 2953 /* process logging options are not allowed for system PMCs */ 2954 if (PMC_IS_SYSTEM_MODE(mode) && (pa.pm_flags & 2955 (PMC_F_LOG_PROCCSW | PMC_F_LOG_PROCEXIT))) { 2956 error = EINVAL; 2957 break; 2958 } 2959 2960 /* 2961 * All sampling mode PMCs need to be able to interrupt the 2962 * CPU. 2963 */ 2964 if (PMC_IS_SAMPLING_MODE(mode)) 2965 caps |= PMC_CAP_INTERRUPT; 2966 2967 /* A valid class specifier should have been passed in. */ 2968 for (n = 0; n < md->pmd_nclass; n++) 2969 if (md->pmd_classes[n].pm_class == pa.pm_class) 2970 break; 2971 if (n == md->pmd_nclass) { 2972 error = EINVAL; 2973 break; 2974 } 2975 2976 /* The requested PMC capabilities should be feasible. */ 2977 if ((md->pmd_classes[n].pm_caps & caps) != caps) { 2978 error = EOPNOTSUPP; 2979 break; 2980 } 2981 2982 PMCDBG(PMC,ALL,2, "event=%d caps=0x%x mode=%d cpu=%d", 2983 pa.pm_ev, caps, mode, cpu); 2984 2985 pmc = pmc_allocate_pmc_descriptor(); 2986 pmc->pm_id = PMC_ID_MAKE_ID(cpu,pa.pm_mode,pa.pm_class, 2987 PMC_ID_INVALID); 2988 pmc->pm_event = pa.pm_ev; 2989 pmc->pm_state = PMC_STATE_FREE; 2990 pmc->pm_caps = caps; 2991 pmc->pm_flags = pa.pm_flags; 2992 2993 /* switch thread to CPU 'cpu' */ 2994 pmc_save_cpu_binding(&pb); 2995 2996 #define PMC_IS_SHAREABLE_PMC(cpu, n) \ 2997 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_state & \ 2998 PMC_PHW_FLAG_IS_SHAREABLE) 2999 #define PMC_IS_UNALLOCATED(cpu, n) \ 3000 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_pmc == NULL) 3001 3002 if (PMC_IS_SYSTEM_MODE(mode)) { 3003 pmc_select_cpu(cpu); 3004 for (n = 0; n < (int) md->pmd_npmc; n++) 3005 if (pmc_can_allocate_row(n, mode) == 0 && 3006 pmc_can_allocate_rowindex( 3007 curthread->td_proc, n, cpu) == 0 && 3008 (PMC_IS_UNALLOCATED(cpu, n) || 3009 PMC_IS_SHAREABLE_PMC(cpu, n)) && 3010 md->pmd_allocate_pmc(cpu, n, pmc, 3011 &pa) == 0) 3012 break; 3013 } else { 3014 /* Process virtual mode */ 3015 for (n = 0; n < (int) md->pmd_npmc; n++) { 3016 if (pmc_can_allocate_row(n, mode) == 0 && 3017 pmc_can_allocate_rowindex( 3018 curthread->td_proc, n, 3019 PMC_CPU_ANY) == 0 && 3020 md->pmd_allocate_pmc(curthread->td_oncpu, 3021 n, pmc, &pa) == 0) 3022 break; 3023 } 3024 } 3025 3026 #undef PMC_IS_UNALLOCATED 3027 #undef PMC_IS_SHAREABLE_PMC 3028 3029 pmc_restore_cpu_binding(&pb); 3030 3031 if (n == (int) md->pmd_npmc) { 3032 pmc_destroy_pmc_descriptor(pmc); 3033 FREE(pmc, M_PMC); 3034 pmc = NULL; 3035 error = EINVAL; 3036 break; 3037 } 3038 3039 /* Fill in the correct value in the ID field */ 3040 pmc->pm_id = PMC_ID_MAKE_ID(cpu,mode,pa.pm_class,n); 3041 3042 PMCDBG(PMC,ALL,2, "ev=%d class=%d mode=%d n=%d -> pmcid=%x", 3043 pmc->pm_event, pa.pm_class, mode, n, pmc->pm_id); 3044 3045 /* Process mode PMCs with logging enabled need log files */ 3046 if (pmc->pm_flags & (PMC_F_LOG_PROCEXIT | PMC_F_LOG_PROCCSW)) 3047 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3048 3049 /* All system mode sampling PMCs require a log file */ 3050 if (PMC_IS_SAMPLING_MODE(mode) && PMC_IS_SYSTEM_MODE(mode)) 3051 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3052 3053 /* 3054 * Configure global pmc's immediately 3055 */ 3056 3057 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pmc))) { 3058 3059 pmc_save_cpu_binding(&pb); 3060 pmc_select_cpu(cpu); 3061 3062 phw = pmc_pcpu[cpu]->pc_hwpmcs[n]; 3063 3064 if ((phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0 || 3065 (error = md->pmd_config_pmc(cpu, n, pmc)) != 0) { 3066 (void) md->pmd_release_pmc(cpu, n, pmc); 3067 pmc_destroy_pmc_descriptor(pmc); 3068 FREE(pmc, M_PMC); 3069 pmc = NULL; 3070 pmc_restore_cpu_binding(&pb); 3071 error = EPERM; 3072 break; 3073 } 3074 3075 pmc_restore_cpu_binding(&pb); 3076 } 3077 3078 pmc->pm_state = PMC_STATE_ALLOCATED; 3079 3080 /* 3081 * mark row disposition 3082 */ 3083 3084 if (PMC_IS_SYSTEM_MODE(mode)) 3085 PMC_MARK_ROW_STANDALONE(n); 3086 else 3087 PMC_MARK_ROW_THREAD(n); 3088 3089 /* 3090 * Register this PMC with the current thread as its owner. 3091 */ 3092 3093 if ((error = 3094 pmc_register_owner(curthread->td_proc, pmc)) != 0) { 3095 pmc_release_pmc_descriptor(pmc); 3096 FREE(pmc, M_PMC); 3097 pmc = NULL; 3098 break; 3099 } 3100 3101 /* 3102 * Return the allocated index. 3103 */ 3104 3105 pa.pm_pmcid = pmc->pm_id; 3106 3107 error = copyout(&pa, arg, sizeof(pa)); 3108 } 3109 break; 3110 3111 3112 /* 3113 * Attach a PMC to a process. 3114 */ 3115 3116 case PMC_OP_PMCATTACH: 3117 { 3118 struct pmc *pm; 3119 struct proc *p; 3120 struct pmc_op_pmcattach a; 3121 3122 sx_assert(&pmc_sx, SX_XLOCKED); 3123 3124 if ((error = copyin(arg, &a, sizeof(a))) != 0) 3125 break; 3126 3127 if (a.pm_pid < 0) { 3128 error = EINVAL; 3129 break; 3130 } else if (a.pm_pid == 0) 3131 a.pm_pid = td->td_proc->p_pid; 3132 3133 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 3134 break; 3135 3136 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) { 3137 error = EINVAL; 3138 break; 3139 } 3140 3141 /* PMCs may be (re)attached only when allocated or stopped */ 3142 if (pm->pm_state == PMC_STATE_RUNNING) { 3143 error = EBUSY; 3144 break; 3145 } else if (pm->pm_state != PMC_STATE_ALLOCATED && 3146 pm->pm_state != PMC_STATE_STOPPED) { 3147 error = EINVAL; 3148 break; 3149 } 3150 3151 /* lookup pid */ 3152 if ((p = pfind(a.pm_pid)) == NULL) { 3153 error = ESRCH; 3154 break; 3155 } 3156 3157 /* 3158 * Ignore processes that are working on exiting. 3159 */ 3160 if (p->p_flag & P_WEXIT) { 3161 error = ESRCH; 3162 PROC_UNLOCK(p); /* pfind() returns a locked process */ 3163 break; 3164 } 3165 3166 /* 3167 * we are allowed to attach a PMC to a process if 3168 * we can debug it. 3169 */ 3170 error = p_candebug(curthread, p); 3171 3172 PROC_UNLOCK(p); 3173 3174 if (error == 0) 3175 error = pmc_attach_process(p, pm); 3176 } 3177 break; 3178 3179 3180 /* 3181 * Detach an attached PMC from a process. 3182 */ 3183 3184 case PMC_OP_PMCDETACH: 3185 { 3186 struct pmc *pm; 3187 struct proc *p; 3188 struct pmc_op_pmcattach a; 3189 3190 if ((error = copyin(arg, &a, sizeof(a))) != 0) 3191 break; 3192 3193 if (a.pm_pid < 0) { 3194 error = EINVAL; 3195 break; 3196 } else if (a.pm_pid == 0) 3197 a.pm_pid = td->td_proc->p_pid; 3198 3199 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 3200 break; 3201 3202 if ((p = pfind(a.pm_pid)) == NULL) { 3203 error = ESRCH; 3204 break; 3205 } 3206 3207 /* 3208 * Treat processes that are in the process of exiting 3209 * as if they were not present. 3210 */ 3211 3212 if (p->p_flag & P_WEXIT) 3213 error = ESRCH; 3214 3215 PROC_UNLOCK(p); /* pfind() returns a locked process */ 3216 3217 if (error == 0) 3218 error = pmc_detach_process(p, pm); 3219 } 3220 break; 3221 3222 3223 /* 3224 * Retrieve the MSR number associated with the counter 3225 * 'pmc_id'. This allows processes to directly use RDPMC 3226 * instructions to read their PMCs, without the overhead of a 3227 * system call. 3228 */ 3229 3230 case PMC_OP_PMCGETMSR: 3231 { 3232 int ri; 3233 struct pmc *pm; 3234 struct pmc_target *pt; 3235 struct pmc_op_getmsr gm; 3236 3237 PMC_DOWNGRADE_SX(); 3238 3239 /* CPU has no 'GETMSR' support */ 3240 if (md->pmd_get_msr == NULL) { 3241 error = ENOSYS; 3242 break; 3243 } 3244 3245 if ((error = copyin(arg, &gm, sizeof(gm))) != 0) 3246 break; 3247 3248 if ((error = pmc_find_pmc(gm.pm_pmcid, &pm)) != 0) 3249 break; 3250 3251 /* 3252 * The allocated PMC has to be a process virtual PMC, 3253 * i.e., of type MODE_T[CS]. Global PMCs can only be 3254 * read using the PMCREAD operation since they may be 3255 * allocated on a different CPU than the one we could 3256 * be running on at the time of the RDPMC instruction. 3257 * 3258 * The GETMSR operation is not allowed for PMCs that 3259 * are inherited across processes. 3260 */ 3261 3262 if (!PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)) || 3263 (pm->pm_flags & PMC_F_DESCENDANTS)) { 3264 error = EINVAL; 3265 break; 3266 } 3267 3268 /* 3269 * It only makes sense to use a RDPMC (or its 3270 * equivalent instruction on non-x86 architectures) on 3271 * a process that has allocated and attached a PMC to 3272 * itself. Conversely the PMC is only allowed to have 3273 * one process attached to it -- its owner. 3274 */ 3275 3276 if ((pt = LIST_FIRST(&pm->pm_targets)) == NULL || 3277 LIST_NEXT(pt, pt_next) != NULL || 3278 pt->pt_process->pp_proc != pm->pm_owner->po_owner) { 3279 error = EINVAL; 3280 break; 3281 } 3282 3283 ri = PMC_TO_ROWINDEX(pm); 3284 3285 if ((error = (*md->pmd_get_msr)(ri, &gm.pm_msr)) < 0) 3286 break; 3287 3288 if ((error = copyout(&gm, arg, sizeof(gm))) < 0) 3289 break; 3290 3291 /* 3292 * Mark our process as using MSRs. Update machine 3293 * state using a forced context switch. 3294 */ 3295 3296 pt->pt_process->pp_flags |= PMC_PP_ENABLE_MSR_ACCESS; 3297 pmc_force_context_switch(); 3298 3299 } 3300 break; 3301 3302 /* 3303 * Release an allocated PMC 3304 */ 3305 3306 case PMC_OP_PMCRELEASE: 3307 { 3308 pmc_id_t pmcid; 3309 struct pmc *pm; 3310 struct pmc_owner *po; 3311 struct pmc_op_simple sp; 3312 3313 /* 3314 * Find PMC pointer for the named PMC. 3315 * 3316 * Use pmc_release_pmc_descriptor() to switch off the 3317 * PMC, remove all its target threads, and remove the 3318 * PMC from its owner's list. 3319 * 3320 * Remove the owner record if this is the last PMC 3321 * owned. 3322 * 3323 * Free up space. 3324 */ 3325 3326 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3327 break; 3328 3329 pmcid = sp.pm_pmcid; 3330 3331 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3332 break; 3333 3334 po = pm->pm_owner; 3335 pmc_release_pmc_descriptor(pm); 3336 pmc_maybe_remove_owner(po); 3337 3338 FREE(pm, M_PMC); 3339 } 3340 break; 3341 3342 3343 /* 3344 * Read and/or write a PMC. 3345 */ 3346 3347 case PMC_OP_PMCRW: 3348 { 3349 uint32_t cpu, ri; 3350 struct pmc *pm; 3351 struct pmc_op_pmcrw *pprw; 3352 struct pmc_op_pmcrw prw; 3353 struct pmc_binding pb; 3354 pmc_value_t oldvalue; 3355 3356 PMC_DOWNGRADE_SX(); 3357 3358 if ((error = copyin(arg, &prw, sizeof(prw))) != 0) 3359 break; 3360 3361 ri = 0; 3362 PMCDBG(PMC,OPS,1, "rw id=%d flags=0x%x", prw.pm_pmcid, 3363 prw.pm_flags); 3364 3365 /* must have at least one flag set */ 3366 if ((prw.pm_flags & (PMC_F_OLDVALUE|PMC_F_NEWVALUE)) == 0) { 3367 error = EINVAL; 3368 break; 3369 } 3370 3371 /* locate pmc descriptor */ 3372 if ((error = pmc_find_pmc(prw.pm_pmcid, &pm)) != 0) 3373 break; 3374 3375 /* Can't read a PMC that hasn't been started. */ 3376 if (pm->pm_state != PMC_STATE_ALLOCATED && 3377 pm->pm_state != PMC_STATE_STOPPED && 3378 pm->pm_state != PMC_STATE_RUNNING) { 3379 error = EINVAL; 3380 break; 3381 } 3382 3383 /* writing a new value is allowed only for 'STOPPED' pmcs */ 3384 if (pm->pm_state == PMC_STATE_RUNNING && 3385 (prw.pm_flags & PMC_F_NEWVALUE)) { 3386 error = EBUSY; 3387 break; 3388 } 3389 3390 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) { 3391 3392 /* 3393 * If this PMC is attached to its owner (i.e., 3394 * the process requesting this operation) and 3395 * is running, then attempt to get an 3396 * upto-date reading from hardware for a READ. 3397 * Writes are only allowed when the PMC is 3398 * stopped, so only update the saved value 3399 * field. 3400 * 3401 * If the PMC is not running, or is not 3402 * attached to its owner, read/write to the 3403 * savedvalue field. 3404 */ 3405 3406 ri = PMC_TO_ROWINDEX(pm); 3407 3408 mtx_pool_lock_spin(pmc_mtxpool, pm); 3409 cpu = curthread->td_oncpu; 3410 3411 if (prw.pm_flags & PMC_F_OLDVALUE) { 3412 if ((pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) && 3413 (pm->pm_state == PMC_STATE_RUNNING)) 3414 error = (*md->pmd_read_pmc)(cpu, ri, 3415 &oldvalue); 3416 else 3417 oldvalue = pm->pm_gv.pm_savedvalue; 3418 } 3419 if (prw.pm_flags & PMC_F_NEWVALUE) 3420 pm->pm_gv.pm_savedvalue = prw.pm_value; 3421 3422 mtx_pool_unlock_spin(pmc_mtxpool, pm); 3423 3424 } else { /* System mode PMCs */ 3425 cpu = PMC_TO_CPU(pm); 3426 ri = PMC_TO_ROWINDEX(pm); 3427 3428 if (pmc_cpu_is_disabled(cpu)) { 3429 error = ENXIO; 3430 break; 3431 } 3432 3433 /* move this thread to CPU 'cpu' */ 3434 pmc_save_cpu_binding(&pb); 3435 pmc_select_cpu(cpu); 3436 3437 critical_enter(); 3438 /* save old value */ 3439 if (prw.pm_flags & PMC_F_OLDVALUE) 3440 if ((error = (*md->pmd_read_pmc)(cpu, ri, 3441 &oldvalue))) 3442 goto error; 3443 /* write out new value */ 3444 if (prw.pm_flags & PMC_F_NEWVALUE) 3445 error = (*md->pmd_write_pmc)(cpu, ri, 3446 prw.pm_value); 3447 error: 3448 critical_exit(); 3449 pmc_restore_cpu_binding(&pb); 3450 if (error) 3451 break; 3452 } 3453 3454 pprw = (struct pmc_op_pmcrw *) arg; 3455 3456 #ifdef DEBUG 3457 if (prw.pm_flags & PMC_F_NEWVALUE) 3458 PMCDBG(PMC,OPS,2, "rw id=%d new %jx -> old %jx", 3459 ri, prw.pm_value, oldvalue); 3460 else if (prw.pm_flags & PMC_F_OLDVALUE) 3461 PMCDBG(PMC,OPS,2, "rw id=%d -> old %jx", ri, oldvalue); 3462 #endif 3463 3464 /* return old value if requested */ 3465 if (prw.pm_flags & PMC_F_OLDVALUE) 3466 if ((error = copyout(&oldvalue, &pprw->pm_value, 3467 sizeof(prw.pm_value)))) 3468 break; 3469 3470 } 3471 break; 3472 3473 3474 /* 3475 * Set the sampling rate for a sampling mode PMC and the 3476 * initial count for a counting mode PMC. 3477 */ 3478 3479 case PMC_OP_PMCSETCOUNT: 3480 { 3481 struct pmc *pm; 3482 struct pmc_op_pmcsetcount sc; 3483 3484 PMC_DOWNGRADE_SX(); 3485 3486 if ((error = copyin(arg, &sc, sizeof(sc))) != 0) 3487 break; 3488 3489 if ((error = pmc_find_pmc(sc.pm_pmcid, &pm)) != 0) 3490 break; 3491 3492 if (pm->pm_state == PMC_STATE_RUNNING) { 3493 error = EBUSY; 3494 break; 3495 } 3496 3497 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 3498 pm->pm_sc.pm_reloadcount = sc.pm_count; 3499 else 3500 pm->pm_sc.pm_initial = sc.pm_count; 3501 } 3502 break; 3503 3504 3505 /* 3506 * Start a PMC. 3507 */ 3508 3509 case PMC_OP_PMCSTART: 3510 { 3511 pmc_id_t pmcid; 3512 struct pmc *pm; 3513 struct pmc_op_simple sp; 3514 3515 sx_assert(&pmc_sx, SX_XLOCKED); 3516 3517 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3518 break; 3519 3520 pmcid = sp.pm_pmcid; 3521 3522 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3523 break; 3524 3525 KASSERT(pmcid == pm->pm_id, 3526 ("[pmc,%d] pmcid %x != id %x", __LINE__, 3527 pm->pm_id, pmcid)); 3528 3529 if (pm->pm_state == PMC_STATE_RUNNING) /* already running */ 3530 break; 3531 else if (pm->pm_state != PMC_STATE_STOPPED && 3532 pm->pm_state != PMC_STATE_ALLOCATED) { 3533 error = EINVAL; 3534 break; 3535 } 3536 3537 error = pmc_start(pm); 3538 } 3539 break; 3540 3541 3542 /* 3543 * Stop a PMC. 3544 */ 3545 3546 case PMC_OP_PMCSTOP: 3547 { 3548 pmc_id_t pmcid; 3549 struct pmc *pm; 3550 struct pmc_op_simple sp; 3551 3552 PMC_DOWNGRADE_SX(); 3553 3554 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3555 break; 3556 3557 pmcid = sp.pm_pmcid; 3558 3559 /* 3560 * Mark the PMC as inactive and invoke the MD stop 3561 * routines if needed. 3562 */ 3563 3564 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3565 break; 3566 3567 KASSERT(pmcid == pm->pm_id, 3568 ("[pmc,%d] pmc id %x != pmcid %x", __LINE__, 3569 pm->pm_id, pmcid)); 3570 3571 if (pm->pm_state == PMC_STATE_STOPPED) /* already stopped */ 3572 break; 3573 else if (pm->pm_state != PMC_STATE_RUNNING) { 3574 error = EINVAL; 3575 break; 3576 } 3577 3578 error = pmc_stop(pm); 3579 } 3580 break; 3581 3582 3583 /* 3584 * Write a user supplied value to the log file. 3585 */ 3586 3587 case PMC_OP_WRITELOG: 3588 { 3589 struct pmc_op_writelog wl; 3590 struct pmc_owner *po; 3591 3592 PMC_DOWNGRADE_SX(); 3593 3594 if ((error = copyin(arg, &wl, sizeof(wl))) != 0) 3595 break; 3596 3597 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 3598 error = EINVAL; 3599 break; 3600 } 3601 3602 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) { 3603 error = EINVAL; 3604 break; 3605 } 3606 3607 error = pmclog_process_userlog(po, &wl); 3608 } 3609 break; 3610 3611 3612 default: 3613 error = EINVAL; 3614 break; 3615 } 3616 3617 if (is_sx_downgraded) 3618 sx_sunlock(&pmc_sx); 3619 else 3620 sx_xunlock(&pmc_sx); 3621 3622 if (error) 3623 atomic_add_int(&pmc_stats.pm_syscall_errors, 1); 3624 3625 PICKUP_GIANT(); 3626 3627 return error; 3628 } 3629 3630 /* 3631 * Helper functions 3632 */ 3633 3634 3635 /* 3636 * Interrupt processing. 3637 * 3638 * Find a free slot in the per-cpu array of PC samples and write the 3639 * current (PMC,PID,PC) triple to it. If an event was successfully 3640 * added, a bit is set in mask 'pmc_cpumask' denoting that the 3641 * DO_SAMPLES hook needs to be invoked from the clock handler. 3642 * 3643 * This function is meant to be called from an NMI handler. It cannot 3644 * use any of the locking primitives supplied by the OS. 3645 */ 3646 3647 int 3648 pmc_process_interrupt(int cpu, struct pmc *pm, uintfptr_t pc, int usermode) 3649 { 3650 int error, ri; 3651 struct thread *td; 3652 struct pmc_sample *ps; 3653 struct pmc_samplebuffer *psb; 3654 3655 error = 0; 3656 ri = PMC_TO_ROWINDEX(pm); 3657 3658 psb = pmc_pcpu[cpu]->pc_sb; 3659 3660 ps = psb->ps_write; 3661 if (ps->ps_pc) { /* in use, reader hasn't caught up */ 3662 pm->pm_stalled = 1; 3663 atomic_add_int(&pmc_stats.pm_intr_bufferfull, 1); 3664 PMCDBG(SAM,INT,1,"(spc) cpu=%d pm=%p pc=%jx um=%d wr=%d rd=%d", 3665 cpu, pm, (uint64_t) pc, usermode, 3666 (int) (psb->ps_write - psb->ps_samples), 3667 (int) (psb->ps_read - psb->ps_samples)); 3668 error = ENOMEM; 3669 goto done; 3670 } 3671 3672 /* fill in entry */ 3673 PMCDBG(SAM,INT,1,"cpu=%d pm=%p pc=%jx um=%d wr=%d rd=%d", cpu, pm, 3674 (uint64_t) pc, usermode, 3675 (int) (psb->ps_write - psb->ps_samples), 3676 (int) (psb->ps_read - psb->ps_samples)); 3677 3678 atomic_add_rel_32(&pm->pm_runcount, 1); /* hold onto PMC */ 3679 ps->ps_pmc = pm; 3680 if ((td = curthread) && td->td_proc) 3681 ps->ps_pid = td->td_proc->p_pid; 3682 else 3683 ps->ps_pid = -1; 3684 ps->ps_usermode = usermode; 3685 ps->ps_pc = pc; /* mark entry as in use */ 3686 3687 /* increment write pointer, modulo ring buffer size */ 3688 ps++; 3689 if (ps == psb->ps_fence) 3690 psb->ps_write = psb->ps_samples; 3691 else 3692 psb->ps_write = ps; 3693 3694 done: 3695 /* mark CPU as needing processing */ 3696 atomic_set_rel_int(&pmc_cpumask, (1 << cpu)); 3697 3698 return error; 3699 } 3700 3701 3702 /* 3703 * Process saved PC samples. 3704 */ 3705 3706 static void 3707 pmc_process_samples(int cpu) 3708 { 3709 int n, ri; 3710 struct pmc *pm; 3711 struct thread *td; 3712 struct pmc_owner *po; 3713 struct pmc_sample *ps; 3714 struct pmc_samplebuffer *psb; 3715 3716 KASSERT(PCPU_GET(cpuid) == cpu, 3717 ("[pmc,%d] not on the correct CPU pcpu=%d cpu=%d", __LINE__, 3718 PCPU_GET(cpuid), cpu)); 3719 3720 psb = pmc_pcpu[cpu]->pc_sb; 3721 3722 for (n = 0; n < pmc_nsamples; n++) { /* bound on #iterations */ 3723 3724 ps = psb->ps_read; 3725 if (ps->ps_pc == (uintfptr_t) 0) /* no data */ 3726 break; 3727 3728 pm = ps->ps_pmc; 3729 po = pm->pm_owner; 3730 3731 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 3732 ("[pmc,%d] pmc=%p non-sampling mode=%d", __LINE__, 3733 pm, PMC_TO_MODE(pm))); 3734 3735 /* Ignore PMCs that have been switched off */ 3736 if (pm->pm_state != PMC_STATE_RUNNING) 3737 goto entrydone; 3738 3739 PMCDBG(SAM,OPS,1,"cpu=%d pm=%p pc=%jx um=%d wr=%d rd=%d", cpu, 3740 pm, (uint64_t) ps->ps_pc, ps->ps_usermode, 3741 (int) (psb->ps_write - psb->ps_samples), 3742 (int) (psb->ps_read - psb->ps_samples)); 3743 3744 /* 3745 * If this is a process-mode PMC that is attached to 3746 * its owner, and if the PC is in user mode, update 3747 * profiling statistics like timer-based profiling 3748 * would have done. 3749 */ 3750 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) { 3751 if (ps->ps_usermode) { 3752 td = FIRST_THREAD_IN_PROC(po->po_owner); 3753 addupc_intr(td, ps->ps_pc, 1); 3754 } 3755 goto entrydone; 3756 } 3757 3758 /* 3759 * Otherwise, this is either a sampling mode PMC that 3760 * is attached to a different process than its owner, 3761 * or a system-wide sampling PMC. Dispatch a log 3762 * entry to the PMC's owner process. 3763 */ 3764 3765 pmclog_process_pcsample(pm, ps); 3766 3767 entrydone: 3768 ps->ps_pc = (uintfptr_t) 0; /* mark entry as free */ 3769 atomic_subtract_rel_32(&pm->pm_runcount, 1); 3770 3771 /* increment read pointer, modulo sample size */ 3772 if (++ps == psb->ps_fence) 3773 psb->ps_read = psb->ps_samples; 3774 else 3775 psb->ps_read = ps; 3776 } 3777 3778 atomic_add_int(&pmc_stats.pm_log_sweeps, 1); 3779 3780 /* Do not re-enable stalled PMCs if we failed to process any samples */ 3781 if (n == 0) 3782 return; 3783 3784 /* 3785 * Restart any stalled sampling PMCs on this CPU. 3786 * 3787 * If the NMI handler sets the pm_stalled field of a PMC after 3788 * the check below, we'll end up processing the stalled PMC at 3789 * the next hardclock tick. 3790 */ 3791 for (n = 0; n < md->pmd_npmc; n++) { 3792 (void) (*md->pmd_get_config)(cpu,n,&pm); 3793 if (pm == NULL || /* !cfg'ed */ 3794 pm->pm_state != PMC_STATE_RUNNING || /* !active */ 3795 !PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) || /* !sampling */ 3796 pm->pm_stalled == 0) /* !stalled */ 3797 continue; 3798 3799 pm->pm_stalled = 0; 3800 ri = PMC_TO_ROWINDEX(pm); 3801 (*md->pmd_start_pmc)(cpu, ri); 3802 } 3803 } 3804 3805 /* 3806 * Event handlers. 3807 */ 3808 3809 /* 3810 * Handle a process exit. 3811 * 3812 * Remove this process from all hash tables. If this process 3813 * owned any PMCs, turn off those PMCs and deallocate them, 3814 * removing any associations with target processes. 3815 * 3816 * This function will be called by the last 'thread' of a 3817 * process. 3818 * 3819 * XXX This eventhandler gets called early in the exit process. 3820 * Consider using a 'hook' invocation from thread_exit() or equivalent 3821 * spot. Another negative is that kse_exit doesn't seem to call 3822 * exit1() [??]. 3823 * 3824 */ 3825 3826 static void 3827 pmc_process_exit(void *arg __unused, struct proc *p) 3828 { 3829 int is_using_hwpmcs; 3830 int cpu; 3831 unsigned int ri; 3832 struct pmc *pm; 3833 struct pmc_process *pp; 3834 struct pmc_owner *po; 3835 pmc_value_t newvalue, tmp; 3836 3837 PROC_LOCK(p); 3838 is_using_hwpmcs = p->p_flag & P_HWPMC; 3839 PROC_UNLOCK(p); 3840 3841 /* 3842 * Log a sysexit event to all SS PMC owners. 3843 */ 3844 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 3845 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 3846 pmclog_process_sysexit(po, p->p_pid); 3847 3848 if (!is_using_hwpmcs) 3849 return; 3850 3851 PMC_GET_SX_XLOCK(); 3852 PMCDBG(PRC,EXT,1,"process-exit proc=%p (%d, %s)", p, p->p_pid, 3853 p->p_comm); 3854 3855 /* 3856 * Since this code is invoked by the last thread in an exiting 3857 * process, we would have context switched IN at some prior 3858 * point. However, with PREEMPTION, kernel mode context 3859 * switches may happen any time, so we want to disable a 3860 * context switch OUT till we get any PMCs targetting this 3861 * process off the hardware. 3862 * 3863 * We also need to atomically remove this process' 3864 * entry from our target process hash table, using 3865 * PMC_FLAG_REMOVE. 3866 */ 3867 PMCDBG(PRC,EXT,1, "process-exit proc=%p (%d, %s)", p, p->p_pid, 3868 p->p_comm); 3869 3870 critical_enter(); /* no preemption */ 3871 3872 cpu = curthread->td_oncpu; 3873 3874 if ((pp = pmc_find_process_descriptor(p, 3875 PMC_FLAG_REMOVE)) != NULL) { 3876 3877 PMCDBG(PRC,EXT,2, 3878 "process-exit proc=%p pmc-process=%p", p, pp); 3879 3880 /* 3881 * The exiting process could the target of 3882 * some PMCs which will be running on 3883 * currently executing CPU. 3884 * 3885 * We need to turn these PMCs off like we 3886 * would do at context switch OUT time. 3887 */ 3888 for (ri = 0; ri < md->pmd_npmc; ri++) { 3889 3890 /* 3891 * Pick up the pmc pointer from hardware 3892 * state similar to the CSW_OUT code. 3893 */ 3894 pm = NULL; 3895 (void) (*md->pmd_get_config)(cpu, ri, &pm); 3896 3897 PMCDBG(PRC,EXT,2, "ri=%d pm=%p", ri, pm); 3898 3899 if (pm == NULL || 3900 !PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 3901 continue; 3902 3903 PMCDBG(PRC,EXT,2, "ppmcs[%d]=%p pm=%p " 3904 "state=%d", ri, pp->pp_pmcs[ri].pp_pmc, 3905 pm, pm->pm_state); 3906 3907 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 3908 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 3909 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 3910 3911 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 3912 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", 3913 __LINE__, pm, ri, pp->pp_pmcs[ri].pp_pmc)); 3914 3915 (void) md->pmd_stop_pmc(cpu, ri); 3916 3917 KASSERT(pm->pm_runcount > 0, 3918 ("[pmc,%d] bad runcount ri %d rc %d", 3919 __LINE__, ri, pm->pm_runcount)); 3920 3921 /* Stop hardware only if it is actually running */ 3922 if (pm->pm_state == PMC_STATE_RUNNING && 3923 pm->pm_stalled == 0) { 3924 md->pmd_read_pmc(cpu, ri, &newvalue); 3925 tmp = newvalue - 3926 PMC_PCPU_SAVED(cpu,ri); 3927 3928 mtx_pool_lock_spin(pmc_mtxpool, pm); 3929 pm->pm_gv.pm_savedvalue += tmp; 3930 pp->pp_pmcs[ri].pp_pmcval += tmp; 3931 mtx_pool_unlock_spin(pmc_mtxpool, pm); 3932 } 3933 3934 atomic_subtract_rel_32(&pm->pm_runcount,1); 3935 3936 KASSERT((int) pm->pm_runcount >= 0, 3937 ("[pmc,%d] runcount is %d", __LINE__, ri)); 3938 3939 (void) md->pmd_config_pmc(cpu, ri, NULL); 3940 } 3941 3942 /* 3943 * Inform the MD layer of this pseudo "context switch 3944 * out" 3945 */ 3946 (void) md->pmd_switch_out(pmc_pcpu[cpu], pp); 3947 3948 critical_exit(); /* ok to be pre-empted now */ 3949 3950 /* 3951 * Unlink this process from the PMCs that are 3952 * targetting it. This will send a signal to 3953 * all PMC owner's whose PMCs are orphaned. 3954 * 3955 * Log PMC value at exit time if requested. 3956 */ 3957 for (ri = 0; ri < md->pmd_npmc; ri++) 3958 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 3959 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 3960 PMC_IS_COUNTING_MODE(PMC_TO_MODE(pm))) 3961 pmclog_process_procexit(pm, pp); 3962 pmc_unlink_target_process(pm, pp); 3963 } 3964 FREE(pp, M_PMC); 3965 3966 } else 3967 critical_exit(); /* pp == NULL */ 3968 3969 3970 /* 3971 * If the process owned PMCs, free them up and free up 3972 * memory. 3973 */ 3974 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 3975 pmc_remove_owner(po); 3976 pmc_destroy_owner_descriptor(po); 3977 } 3978 3979 sx_xunlock(&pmc_sx); 3980 } 3981 3982 /* 3983 * Handle a process fork. 3984 * 3985 * If the parent process 'p1' is under HWPMC monitoring, then copy 3986 * over any attached PMCs that have 'do_descendants' semantics. 3987 */ 3988 3989 static void 3990 pmc_process_fork(void *arg __unused, struct proc *p1, struct proc *newproc, 3991 int flags) 3992 { 3993 int is_using_hwpmcs; 3994 unsigned int ri; 3995 uint32_t do_descendants; 3996 struct pmc *pm; 3997 struct pmc_owner *po; 3998 struct pmc_process *ppnew, *ppold; 3999 4000 (void) flags; /* unused parameter */ 4001 4002 PROC_LOCK(p1); 4003 is_using_hwpmcs = p1->p_flag & P_HWPMC; 4004 PROC_UNLOCK(p1); 4005 4006 /* 4007 * If there are system-wide sampling PMCs active, we need to 4008 * log all fork events to their owner's logs. 4009 */ 4010 4011 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4012 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4013 pmclog_process_procfork(po, p1->p_pid, newproc->p_pid); 4014 4015 if (!is_using_hwpmcs) 4016 return; 4017 4018 PMC_GET_SX_XLOCK(); 4019 PMCDBG(PMC,FRK,1, "process-fork proc=%p (%d, %s) -> %p", p1, 4020 p1->p_pid, p1->p_comm, newproc); 4021 4022 /* 4023 * If the parent process (curthread->td_proc) is a 4024 * target of any PMCs, look for PMCs that are to be 4025 * inherited, and link these into the new process 4026 * descriptor. 4027 */ 4028 if ((ppold = pmc_find_process_descriptor(curthread->td_proc, 4029 PMC_FLAG_NONE)) == NULL) 4030 goto done; /* nothing to do */ 4031 4032 do_descendants = 0; 4033 for (ri = 0; ri < md->pmd_npmc; ri++) 4034 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL) 4035 do_descendants |= pm->pm_flags & PMC_F_DESCENDANTS; 4036 if (do_descendants == 0) /* nothing to do */ 4037 goto done; 4038 4039 /* allocate a descriptor for the new process */ 4040 if ((ppnew = pmc_find_process_descriptor(newproc, 4041 PMC_FLAG_ALLOCATE)) == NULL) 4042 goto done; 4043 4044 /* 4045 * Run through all PMCs that were targeting the old process 4046 * and which specified F_DESCENDANTS and attach them to the 4047 * new process. 4048 * 4049 * Log the fork event to all owners of PMCs attached to this 4050 * process, if not already logged. 4051 */ 4052 for (ri = 0; ri < md->pmd_npmc; ri++) 4053 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL && 4054 (pm->pm_flags & PMC_F_DESCENDANTS)) { 4055 pmc_link_target_process(pm, ppnew); 4056 po = pm->pm_owner; 4057 if (po->po_sscount == 0 && 4058 po->po_flags & PMC_PO_OWNS_LOGFILE) 4059 pmclog_process_procfork(po, p1->p_pid, 4060 newproc->p_pid); 4061 } 4062 4063 /* 4064 * Now mark the new process as being tracked by this driver. 4065 */ 4066 PROC_LOCK(newproc); 4067 newproc->p_flag |= P_HWPMC; 4068 PROC_UNLOCK(newproc); 4069 4070 done: 4071 sx_xunlock(&pmc_sx); 4072 } 4073 4074 4075 /* 4076 * initialization 4077 */ 4078 4079 static const char *pmc_name_of_pmcclass[] = { 4080 #undef __PMC_CLASS 4081 #define __PMC_CLASS(N) #N , 4082 __PMC_CLASSES() 4083 }; 4084 4085 static int 4086 pmc_initialize(void) 4087 { 4088 int cpu, error, n; 4089 struct pmc_binding pb; 4090 struct pmc_samplebuffer *sb; 4091 4092 md = NULL; 4093 error = 0; 4094 4095 #ifdef DEBUG 4096 /* parse debug flags first */ 4097 if (TUNABLE_STR_FETCH(PMC_SYSCTL_NAME_PREFIX "debugflags", 4098 pmc_debugstr, sizeof(pmc_debugstr))) 4099 pmc_debugflags_parse(pmc_debugstr, 4100 pmc_debugstr+strlen(pmc_debugstr)); 4101 #endif 4102 4103 PMCDBG(MOD,INI,0, "PMC Initialize (version %x)", PMC_VERSION); 4104 4105 /* check kernel version */ 4106 if (pmc_kernel_version != PMC_VERSION) { 4107 if (pmc_kernel_version == 0) 4108 printf("hwpmc: this kernel has not been compiled with " 4109 "'options HWPMC_HOOKS'.\n"); 4110 else 4111 printf("hwpmc: kernel version (0x%x) does not match " 4112 "module version (0x%x).\n", pmc_kernel_version, 4113 PMC_VERSION); 4114 return EPROGMISMATCH; 4115 } 4116 4117 /* 4118 * check sysctl parameters 4119 */ 4120 4121 if (pmc_hashsize <= 0) { 4122 (void) printf("hwpmc: tunable hashsize=%d must be greater " 4123 "than zero.\n", pmc_hashsize); 4124 pmc_hashsize = PMC_HASH_SIZE; 4125 } 4126 4127 if (pmc_nsamples <= 0 || pmc_nsamples > 65535) { 4128 (void) printf("hwpmc: tunable nsamples=%d out of range.\n", 4129 pmc_nsamples); 4130 pmc_nsamples = PMC_NSAMPLES; 4131 } 4132 4133 md = pmc_md_initialize(); 4134 4135 if (md == NULL || md->pmd_init == NULL) 4136 return ENOSYS; 4137 4138 /* allocate space for the per-cpu array */ 4139 MALLOC(pmc_pcpu, struct pmc_cpu **, mp_ncpus * sizeof(struct pmc_cpu *), 4140 M_PMC, M_WAITOK|M_ZERO); 4141 4142 /* per-cpu 'saved values' for managing process-mode PMCs */ 4143 MALLOC(pmc_pcpu_saved, pmc_value_t *, 4144 sizeof(pmc_value_t) * mp_ncpus * md->pmd_npmc, M_PMC, M_WAITOK); 4145 4146 /* perform cpu dependent initialization */ 4147 pmc_save_cpu_binding(&pb); 4148 for (cpu = 0; cpu < mp_ncpus; cpu++) { 4149 if (pmc_cpu_is_disabled(cpu)) 4150 continue; 4151 pmc_select_cpu(cpu); 4152 if ((error = md->pmd_init(cpu)) != 0) 4153 break; 4154 } 4155 pmc_restore_cpu_binding(&pb); 4156 4157 if (error != 0) 4158 return error; 4159 4160 /* allocate space for the sample array */ 4161 for (cpu = 0; cpu < mp_ncpus; cpu++) { 4162 if (pmc_cpu_is_disabled(cpu)) 4163 continue; 4164 MALLOC(sb, struct pmc_samplebuffer *, 4165 sizeof(struct pmc_samplebuffer) + 4166 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 4167 M_WAITOK|M_ZERO); 4168 4169 sb->ps_read = sb->ps_write = sb->ps_samples; 4170 sb->ps_fence = sb->ps_samples + pmc_nsamples; 4171 KASSERT(pmc_pcpu[cpu] != NULL, 4172 ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu)); 4173 4174 pmc_pcpu[cpu]->pc_sb = sb; 4175 } 4176 4177 /* allocate space for the row disposition array */ 4178 pmc_pmcdisp = malloc(sizeof(enum pmc_mode) * md->pmd_npmc, 4179 M_PMC, M_WAITOK|M_ZERO); 4180 4181 KASSERT(pmc_pmcdisp != NULL, 4182 ("[pmc,%d] pmcdisp allocation returned NULL", __LINE__)); 4183 4184 /* mark all PMCs as available */ 4185 for (n = 0; n < (int) md->pmd_npmc; n++) 4186 PMC_MARK_ROW_FREE(n); 4187 4188 /* allocate thread hash tables */ 4189 pmc_ownerhash = hashinit(pmc_hashsize, M_PMC, 4190 &pmc_ownerhashmask); 4191 4192 pmc_processhash = hashinit(pmc_hashsize, M_PMC, 4193 &pmc_processhashmask); 4194 mtx_init(&pmc_processhash_mtx, "pmc-process-hash", "pmc-leaf", 4195 MTX_SPIN); 4196 4197 LIST_INIT(&pmc_ss_owners); 4198 pmc_ss_count = 0; 4199 4200 /* allocate a pool of spin mutexes */ 4201 pmc_mtxpool = mtx_pool_create("pmc-leaf", pmc_mtxpool_size, 4202 MTX_SPIN); 4203 4204 PMCDBG(MOD,INI,1, "pmc_ownerhash=%p, mask=0x%lx " 4205 "targethash=%p mask=0x%lx", pmc_ownerhash, pmc_ownerhashmask, 4206 pmc_processhash, pmc_processhashmask); 4207 4208 /* register process {exit,fork,exec} handlers */ 4209 pmc_exit_tag = EVENTHANDLER_REGISTER(process_exit, 4210 pmc_process_exit, NULL, EVENTHANDLER_PRI_ANY); 4211 pmc_fork_tag = EVENTHANDLER_REGISTER(process_fork, 4212 pmc_process_fork, NULL, EVENTHANDLER_PRI_ANY); 4213 4214 /* initialize logging */ 4215 pmclog_initialize(); 4216 4217 /* set hook functions */ 4218 pmc_intr = md->pmd_intr; 4219 pmc_hook = pmc_hook_handler; 4220 4221 if (error == 0) { 4222 printf(PMC_MODULE_NAME ":"); 4223 for (n = 0; n < (int) md->pmd_nclass; n++) { 4224 printf(" %s/%d/0x%b", 4225 pmc_name_of_pmcclass[md->pmd_classes[n].pm_class], 4226 md->pmd_nclasspmcs[n], 4227 md->pmd_classes[n].pm_caps, 4228 "\20" 4229 "\1INT\2USR\3SYS\4EDG\5THR" 4230 "\6REA\7WRI\10INV\11QUA\12PRC" 4231 "\13TAG\14CSC"); 4232 } 4233 printf("\n"); 4234 } 4235 4236 return error; 4237 } 4238 4239 /* prepare to be unloaded */ 4240 static void 4241 pmc_cleanup(void) 4242 { 4243 int cpu; 4244 struct pmc_ownerhash *ph; 4245 struct pmc_owner *po, *tmp; 4246 struct pmc_binding pb; 4247 #ifdef DEBUG 4248 struct pmc_processhash *prh; 4249 #endif 4250 4251 PMCDBG(MOD,INI,0, "%s", "cleanup"); 4252 4253 /* switch off sampling */ 4254 atomic_store_rel_int(&pmc_cpumask, 0); 4255 pmc_intr = NULL; 4256 4257 sx_xlock(&pmc_sx); 4258 if (pmc_hook == NULL) { /* being unloaded already */ 4259 sx_xunlock(&pmc_sx); 4260 return; 4261 } 4262 4263 pmc_hook = NULL; /* prevent new threads from entering module */ 4264 4265 /* deregister event handlers */ 4266 EVENTHANDLER_DEREGISTER(process_fork, pmc_fork_tag); 4267 EVENTHANDLER_DEREGISTER(process_exit, pmc_exit_tag); 4268 4269 /* send SIGBUS to all owner threads, free up allocations */ 4270 if (pmc_ownerhash) 4271 for (ph = pmc_ownerhash; 4272 ph <= &pmc_ownerhash[pmc_ownerhashmask]; 4273 ph++) { 4274 LIST_FOREACH_SAFE(po, ph, po_next, tmp) { 4275 pmc_remove_owner(po); 4276 4277 /* send SIGBUS to owner processes */ 4278 PMCDBG(MOD,INI,2, "cleanup signal proc=%p " 4279 "(%d, %s)", po->po_owner, 4280 po->po_owner->p_pid, 4281 po->po_owner->p_comm); 4282 4283 PROC_LOCK(po->po_owner); 4284 psignal(po->po_owner, SIGBUS); 4285 PROC_UNLOCK(po->po_owner); 4286 4287 pmc_destroy_owner_descriptor(po); 4288 } 4289 } 4290 4291 /* reclaim allocated data structures */ 4292 if (pmc_mtxpool) 4293 mtx_pool_destroy(&pmc_mtxpool); 4294 4295 mtx_destroy(&pmc_processhash_mtx); 4296 if (pmc_processhash) { 4297 #ifdef DEBUG 4298 struct pmc_process *pp; 4299 4300 PMCDBG(MOD,INI,3, "%s", "destroy process hash"); 4301 for (prh = pmc_processhash; 4302 prh <= &pmc_processhash[pmc_processhashmask]; 4303 prh++) 4304 LIST_FOREACH(pp, prh, pp_next) 4305 PMCDBG(MOD,INI,3, "pid=%d", pp->pp_proc->p_pid); 4306 #endif 4307 4308 hashdestroy(pmc_processhash, M_PMC, pmc_processhashmask); 4309 pmc_processhash = NULL; 4310 } 4311 4312 if (pmc_ownerhash) { 4313 PMCDBG(MOD,INI,3, "%s", "destroy owner hash"); 4314 hashdestroy(pmc_ownerhash, M_PMC, pmc_ownerhashmask); 4315 pmc_ownerhash = NULL; 4316 } 4317 4318 KASSERT(LIST_EMPTY(&pmc_ss_owners), 4319 ("[pmc,%d] Global SS owner list not empty", __LINE__)); 4320 KASSERT(pmc_ss_count == 0, 4321 ("[pmc,%d] Global SS count not empty", __LINE__)); 4322 4323 /* free the per-cpu sample buffers */ 4324 for (cpu = 0; cpu < mp_ncpus; cpu++) { 4325 if (pmc_cpu_is_disabled(cpu)) 4326 continue; 4327 KASSERT(pmc_pcpu[cpu]->pc_sb != NULL, 4328 ("[pmc,%d] Null cpu sample buffer cpu=%d", __LINE__, 4329 cpu)); 4330 FREE(pmc_pcpu[cpu]->pc_sb, M_PMC); 4331 pmc_pcpu[cpu]->pc_sb = NULL; 4332 } 4333 4334 /* do processor dependent cleanup */ 4335 PMCDBG(MOD,INI,3, "%s", "md cleanup"); 4336 if (md) { 4337 pmc_save_cpu_binding(&pb); 4338 for (cpu = 0; cpu < mp_ncpus; cpu++) { 4339 PMCDBG(MOD,INI,1,"pmc-cleanup cpu=%d pcs=%p", 4340 cpu, pmc_pcpu[cpu]); 4341 if (pmc_cpu_is_disabled(cpu)) 4342 continue; 4343 pmc_select_cpu(cpu); 4344 if (pmc_pcpu[cpu]) 4345 (void) md->pmd_cleanup(cpu); 4346 } 4347 FREE(md, M_PMC); 4348 md = NULL; 4349 pmc_restore_cpu_binding(&pb); 4350 } 4351 4352 /* deallocate per-cpu structures */ 4353 FREE(pmc_pcpu, M_PMC); 4354 pmc_pcpu = NULL; 4355 4356 FREE(pmc_pcpu_saved, M_PMC); 4357 pmc_pcpu_saved = NULL; 4358 4359 if (pmc_pmcdisp) { 4360 FREE(pmc_pmcdisp, M_PMC); 4361 pmc_pmcdisp = NULL; 4362 } 4363 4364 pmclog_shutdown(); 4365 4366 sx_xunlock(&pmc_sx); /* we are done */ 4367 } 4368 4369 /* 4370 * The function called at load/unload. 4371 */ 4372 4373 static int 4374 load (struct module *module __unused, int cmd, void *arg __unused) 4375 { 4376 int error; 4377 4378 error = 0; 4379 4380 switch (cmd) { 4381 case MOD_LOAD : 4382 /* initialize the subsystem */ 4383 error = pmc_initialize(); 4384 if (error != 0) 4385 break; 4386 PMCDBG(MOD,INI,1, "syscall=%d ncpus=%d", 4387 pmc_syscall_num, mp_ncpus); 4388 break; 4389 4390 4391 case MOD_UNLOAD : 4392 case MOD_SHUTDOWN: 4393 pmc_cleanup(); 4394 PMCDBG(MOD,INI,1, "%s", "unloaded"); 4395 break; 4396 4397 default : 4398 error = EINVAL; /* XXX should panic(9) */ 4399 break; 4400 } 4401 4402 return error; 4403 } 4404 4405 /* memory pool */ 4406 MALLOC_DEFINE(M_PMC, "pmc", "Memory space for the PMC module"); 4407