1 /*- 2 * Copyright (c) 2003-2007 Joseph Koshy 3 * Copyright (c) 2007 The FreeBSD Foundation 4 * All rights reserved. 5 * 6 * Portions of this software were developed by A. Joseph Koshy under 7 * sponsorship from the FreeBSD Foundation and Google, Inc. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 * 30 */ 31 32 #include <sys/cdefs.h> 33 __FBSDID("$FreeBSD$"); 34 35 #include <sys/param.h> 36 #include <sys/eventhandler.h> 37 #include <sys/jail.h> 38 #include <sys/kernel.h> 39 #include <sys/kthread.h> 40 #include <sys/limits.h> 41 #include <sys/lock.h> 42 #include <sys/malloc.h> 43 #include <sys/module.h> 44 #include <sys/mutex.h> 45 #include <sys/pmc.h> 46 #include <sys/pmckern.h> 47 #include <sys/pmclog.h> 48 #include <sys/priv.h> 49 #include <sys/proc.h> 50 #include <sys/queue.h> 51 #include <sys/resourcevar.h> 52 #include <sys/sched.h> 53 #include <sys/signalvar.h> 54 #include <sys/smp.h> 55 #include <sys/sx.h> 56 #include <sys/sysctl.h> 57 #include <sys/sysent.h> 58 #include <sys/systm.h> 59 #include <sys/vnode.h> 60 61 #include <sys/linker.h> /* needs to be after <sys/malloc.h> */ 62 63 #include <machine/atomic.h> 64 #include <machine/md_var.h> 65 66 /* 67 * Types 68 */ 69 70 enum pmc_flags { 71 PMC_FLAG_NONE = 0x00, /* do nothing */ 72 PMC_FLAG_REMOVE = 0x01, /* atomically remove entry from hash */ 73 PMC_FLAG_ALLOCATE = 0x02, /* add entry to hash if not found */ 74 }; 75 76 /* 77 * The offset in sysent where the syscall is allocated. 78 */ 79 80 static int pmc_syscall_num = NO_SYSCALL; 81 struct pmc_cpu **pmc_pcpu; /* per-cpu state */ 82 pmc_value_t *pmc_pcpu_saved; /* saved PMC values: CSW handling */ 83 84 #define PMC_PCPU_SAVED(C,R) pmc_pcpu_saved[(R) + md->pmd_npmc*(C)] 85 86 struct mtx_pool *pmc_mtxpool; 87 static int *pmc_pmcdisp; /* PMC row dispositions */ 88 89 #define PMC_ROW_DISP_IS_FREE(R) (pmc_pmcdisp[(R)] == 0) 90 #define PMC_ROW_DISP_IS_THREAD(R) (pmc_pmcdisp[(R)] > 0) 91 #define PMC_ROW_DISP_IS_STANDALONE(R) (pmc_pmcdisp[(R)] < 0) 92 93 #define PMC_MARK_ROW_FREE(R) do { \ 94 pmc_pmcdisp[(R)] = 0; \ 95 } while (0) 96 97 #define PMC_MARK_ROW_STANDALONE(R) do { \ 98 KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \ 99 __LINE__)); \ 100 atomic_add_int(&pmc_pmcdisp[(R)], -1); \ 101 KASSERT(pmc_pmcdisp[(R)] >= (-mp_ncpus), ("[pmc,%d] row " \ 102 "disposition error", __LINE__)); \ 103 } while (0) 104 105 #define PMC_UNMARK_ROW_STANDALONE(R) do { \ 106 atomic_add_int(&pmc_pmcdisp[(R)], 1); \ 107 KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \ 108 __LINE__)); \ 109 } while (0) 110 111 #define PMC_MARK_ROW_THREAD(R) do { \ 112 KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \ 113 __LINE__)); \ 114 atomic_add_int(&pmc_pmcdisp[(R)], 1); \ 115 } while (0) 116 117 #define PMC_UNMARK_ROW_THREAD(R) do { \ 118 atomic_add_int(&pmc_pmcdisp[(R)], -1); \ 119 KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \ 120 __LINE__)); \ 121 } while (0) 122 123 124 /* various event handlers */ 125 static eventhandler_tag pmc_exit_tag, pmc_fork_tag; 126 127 /* Module statistics */ 128 struct pmc_op_getdriverstats pmc_stats; 129 130 /* Machine/processor dependent operations */ 131 struct pmc_mdep *md; 132 133 /* 134 * Hash tables mapping owner processes and target threads to PMCs. 135 */ 136 137 struct mtx pmc_processhash_mtx; /* spin mutex */ 138 static u_long pmc_processhashmask; 139 static LIST_HEAD(pmc_processhash, pmc_process) *pmc_processhash; 140 141 /* 142 * Hash table of PMC owner descriptors. This table is protected by 143 * the shared PMC "sx" lock. 144 */ 145 146 static u_long pmc_ownerhashmask; 147 static LIST_HEAD(pmc_ownerhash, pmc_owner) *pmc_ownerhash; 148 149 /* 150 * List of PMC owners with system-wide sampling PMCs. 151 */ 152 153 static LIST_HEAD(, pmc_owner) pmc_ss_owners; 154 155 156 /* 157 * Prototypes 158 */ 159 160 #ifdef DEBUG 161 static int pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS); 162 static int pmc_debugflags_parse(char *newstr, char *fence); 163 #endif 164 165 static int load(struct module *module, int cmd, void *arg); 166 static int pmc_attach_process(struct proc *p, struct pmc *pm); 167 static struct pmc *pmc_allocate_pmc_descriptor(void); 168 static struct pmc_owner *pmc_allocate_owner_descriptor(struct proc *p); 169 static int pmc_attach_one_process(struct proc *p, struct pmc *pm); 170 static int pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, 171 int cpu); 172 static int pmc_can_attach(struct pmc *pm, struct proc *p); 173 static void pmc_capture_user_callchain(int cpu, struct trapframe *tf); 174 static void pmc_cleanup(void); 175 static int pmc_detach_process(struct proc *p, struct pmc *pm); 176 static int pmc_detach_one_process(struct proc *p, struct pmc *pm, 177 int flags); 178 static void pmc_destroy_owner_descriptor(struct pmc_owner *po); 179 static struct pmc_owner *pmc_find_owner_descriptor(struct proc *p); 180 static int pmc_find_pmc(pmc_id_t pmcid, struct pmc **pm); 181 static struct pmc *pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, 182 pmc_id_t pmc); 183 static struct pmc_process *pmc_find_process_descriptor(struct proc *p, 184 uint32_t mode); 185 static void pmc_force_context_switch(void); 186 static void pmc_link_target_process(struct pmc *pm, 187 struct pmc_process *pp); 188 static void pmc_log_all_process_mappings(struct pmc_owner *po); 189 static void pmc_log_kernel_mappings(struct pmc *pm); 190 static void pmc_log_process_mappings(struct pmc_owner *po, struct proc *p); 191 static void pmc_maybe_remove_owner(struct pmc_owner *po); 192 static void pmc_process_csw_in(struct thread *td); 193 static void pmc_process_csw_out(struct thread *td); 194 static void pmc_process_exit(void *arg, struct proc *p); 195 static void pmc_process_fork(void *arg, struct proc *p1, 196 struct proc *p2, int n); 197 static void pmc_process_samples(int cpu); 198 static void pmc_release_pmc_descriptor(struct pmc *pmc); 199 static void pmc_remove_owner(struct pmc_owner *po); 200 static void pmc_remove_process_descriptor(struct pmc_process *pp); 201 static void pmc_restore_cpu_binding(struct pmc_binding *pb); 202 static void pmc_save_cpu_binding(struct pmc_binding *pb); 203 static void pmc_select_cpu(int cpu); 204 static int pmc_start(struct pmc *pm); 205 static int pmc_stop(struct pmc *pm); 206 static int pmc_syscall_handler(struct thread *td, void *syscall_args); 207 static void pmc_unlink_target_process(struct pmc *pmc, 208 struct pmc_process *pp); 209 210 /* 211 * Kernel tunables and sysctl(8) interface. 212 */ 213 214 SYSCTL_NODE(_kern, OID_AUTO, hwpmc, CTLFLAG_RW, 0, "HWPMC parameters"); 215 216 static int pmc_callchaindepth = PMC_CALLCHAIN_DEPTH; 217 TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "callchaindepth", &pmc_callchaindepth); 218 SYSCTL_INT(_kern_hwpmc, OID_AUTO, callchaindepth, CTLFLAG_TUN|CTLFLAG_RD, 219 &pmc_callchaindepth, 0, "depth of call chain records"); 220 221 #ifdef DEBUG 222 struct pmc_debugflags pmc_debugflags = PMC_DEBUG_DEFAULT_FLAGS; 223 char pmc_debugstr[PMC_DEBUG_STRSIZE]; 224 TUNABLE_STR(PMC_SYSCTL_NAME_PREFIX "debugflags", pmc_debugstr, 225 sizeof(pmc_debugstr)); 226 SYSCTL_PROC(_kern_hwpmc, OID_AUTO, debugflags, 227 CTLTYPE_STRING|CTLFLAG_RW|CTLFLAG_TUN, 228 0, 0, pmc_debugflags_sysctl_handler, "A", "debug flags"); 229 #endif 230 231 /* 232 * kern.hwpmc.hashrows -- determines the number of rows in the 233 * of the hash table used to look up threads 234 */ 235 236 static int pmc_hashsize = PMC_HASH_SIZE; 237 TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "hashsize", &pmc_hashsize); 238 SYSCTL_INT(_kern_hwpmc, OID_AUTO, hashsize, CTLFLAG_TUN|CTLFLAG_RD, 239 &pmc_hashsize, 0, "rows in hash tables"); 240 241 /* 242 * kern.hwpmc.nsamples --- number of PC samples/callchain stacks per CPU 243 */ 244 245 static int pmc_nsamples = PMC_NSAMPLES; 246 TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "nsamples", &pmc_nsamples); 247 SYSCTL_INT(_kern_hwpmc, OID_AUTO, nsamples, CTLFLAG_TUN|CTLFLAG_RD, 248 &pmc_nsamples, 0, "number of PC samples per CPU"); 249 250 251 /* 252 * kern.hwpmc.mtxpoolsize -- number of mutexes in the mutex pool. 253 */ 254 255 static int pmc_mtxpool_size = PMC_MTXPOOL_SIZE; 256 TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "mtxpoolsize", &pmc_mtxpool_size); 257 SYSCTL_INT(_kern_hwpmc, OID_AUTO, mtxpoolsize, CTLFLAG_TUN|CTLFLAG_RD, 258 &pmc_mtxpool_size, 0, "size of spin mutex pool"); 259 260 261 /* 262 * security.bsd.unprivileged_syspmcs -- allow non-root processes to 263 * allocate system-wide PMCs. 264 * 265 * Allowing unprivileged processes to allocate system PMCs is convenient 266 * if system-wide measurements need to be taken concurrently with other 267 * per-process measurements. This feature is turned off by default. 268 */ 269 270 static int pmc_unprivileged_syspmcs = 0; 271 TUNABLE_INT("security.bsd.unprivileged_syspmcs", &pmc_unprivileged_syspmcs); 272 SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_syspmcs, CTLFLAG_RW, 273 &pmc_unprivileged_syspmcs, 0, 274 "allow unprivileged process to allocate system PMCs"); 275 276 /* 277 * Hash function. Discard the lower 2 bits of the pointer since 278 * these are always zero for our uses. The hash multiplier is 279 * round((2^LONG_BIT) * ((sqrt(5)-1)/2)). 280 */ 281 282 #if LONG_BIT == 64 283 #define _PMC_HM 11400714819323198486u 284 #elif LONG_BIT == 32 285 #define _PMC_HM 2654435769u 286 #else 287 #error Must know the size of 'long' to compile 288 #endif 289 290 #define PMC_HASH_PTR(P,M) ((((unsigned long) (P) >> 2) * _PMC_HM) & (M)) 291 292 /* 293 * Syscall structures 294 */ 295 296 /* The `sysent' for the new syscall */ 297 static struct sysent pmc_sysent = { 298 2, /* sy_narg */ 299 pmc_syscall_handler /* sy_call */ 300 }; 301 302 static struct syscall_module_data pmc_syscall_mod = { 303 load, 304 NULL, 305 &pmc_syscall_num, 306 &pmc_sysent, 307 { 0, NULL } 308 }; 309 310 static moduledata_t pmc_mod = { 311 PMC_MODULE_NAME, 312 syscall_module_handler, 313 &pmc_syscall_mod 314 }; 315 316 DECLARE_MODULE(pmc, pmc_mod, SI_SUB_SMP, SI_ORDER_ANY); 317 MODULE_VERSION(pmc, PMC_VERSION); 318 319 #ifdef DEBUG 320 enum pmc_dbgparse_state { 321 PMCDS_WS, /* in whitespace */ 322 PMCDS_MAJOR, /* seen a major keyword */ 323 PMCDS_MINOR 324 }; 325 326 static int 327 pmc_debugflags_parse(char *newstr, char *fence) 328 { 329 char c, *p, *q; 330 struct pmc_debugflags *tmpflags; 331 int error, found, *newbits, tmp; 332 size_t kwlen; 333 334 MALLOC(tmpflags, struct pmc_debugflags *, sizeof(*tmpflags), 335 M_PMC, M_WAITOK|M_ZERO); 336 337 p = newstr; 338 error = 0; 339 340 for (; p < fence && (c = *p); p++) { 341 342 /* skip white space */ 343 if (c == ' ' || c == '\t') 344 continue; 345 346 /* look for a keyword followed by "=" */ 347 for (q = p; p < fence && (c = *p) && c != '='; p++) 348 ; 349 if (c != '=') { 350 error = EINVAL; 351 goto done; 352 } 353 354 kwlen = p - q; 355 newbits = NULL; 356 357 /* lookup flag group name */ 358 #define DBG_SET_FLAG_MAJ(S,F) \ 359 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \ 360 newbits = &tmpflags->pdb_ ## F; 361 362 DBG_SET_FLAG_MAJ("cpu", CPU); 363 DBG_SET_FLAG_MAJ("csw", CSW); 364 DBG_SET_FLAG_MAJ("logging", LOG); 365 DBG_SET_FLAG_MAJ("module", MOD); 366 DBG_SET_FLAG_MAJ("md", MDP); 367 DBG_SET_FLAG_MAJ("owner", OWN); 368 DBG_SET_FLAG_MAJ("pmc", PMC); 369 DBG_SET_FLAG_MAJ("process", PRC); 370 DBG_SET_FLAG_MAJ("sampling", SAM); 371 372 if (newbits == NULL) { 373 error = EINVAL; 374 goto done; 375 } 376 377 p++; /* skip the '=' */ 378 379 /* Now parse the individual flags */ 380 tmp = 0; 381 newflag: 382 for (q = p; p < fence && (c = *p); p++) 383 if (c == ' ' || c == '\t' || c == ',') 384 break; 385 386 /* p == fence or c == ws or c == "," or c == 0 */ 387 388 if ((kwlen = p - q) == 0) { 389 *newbits = tmp; 390 continue; 391 } 392 393 found = 0; 394 #define DBG_SET_FLAG_MIN(S,F) \ 395 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \ 396 tmp |= found = (1 << PMC_DEBUG_MIN_ ## F) 397 398 /* a '*' denotes all possible flags in the group */ 399 if (kwlen == 1 && *q == '*') 400 tmp = found = ~0; 401 /* look for individual flag names */ 402 DBG_SET_FLAG_MIN("allocaterow", ALR); 403 DBG_SET_FLAG_MIN("allocate", ALL); 404 DBG_SET_FLAG_MIN("attach", ATT); 405 DBG_SET_FLAG_MIN("bind", BND); 406 DBG_SET_FLAG_MIN("config", CFG); 407 DBG_SET_FLAG_MIN("exec", EXC); 408 DBG_SET_FLAG_MIN("exit", EXT); 409 DBG_SET_FLAG_MIN("find", FND); 410 DBG_SET_FLAG_MIN("flush", FLS); 411 DBG_SET_FLAG_MIN("fork", FRK); 412 DBG_SET_FLAG_MIN("getbuf", GTB); 413 DBG_SET_FLAG_MIN("hook", PMH); 414 DBG_SET_FLAG_MIN("init", INI); 415 DBG_SET_FLAG_MIN("intr", INT); 416 DBG_SET_FLAG_MIN("linktarget", TLK); 417 DBG_SET_FLAG_MIN("mayberemove", OMR); 418 DBG_SET_FLAG_MIN("ops", OPS); 419 DBG_SET_FLAG_MIN("read", REA); 420 DBG_SET_FLAG_MIN("register", REG); 421 DBG_SET_FLAG_MIN("release", REL); 422 DBG_SET_FLAG_MIN("remove", ORM); 423 DBG_SET_FLAG_MIN("sample", SAM); 424 DBG_SET_FLAG_MIN("scheduleio", SIO); 425 DBG_SET_FLAG_MIN("select", SEL); 426 DBG_SET_FLAG_MIN("signal", SIG); 427 DBG_SET_FLAG_MIN("swi", SWI); 428 DBG_SET_FLAG_MIN("swo", SWO); 429 DBG_SET_FLAG_MIN("start", STA); 430 DBG_SET_FLAG_MIN("stop", STO); 431 DBG_SET_FLAG_MIN("syscall", PMS); 432 DBG_SET_FLAG_MIN("unlinktarget", TUL); 433 DBG_SET_FLAG_MIN("write", WRI); 434 if (found == 0) { 435 /* unrecognized flag name */ 436 error = EINVAL; 437 goto done; 438 } 439 440 if (c == 0 || c == ' ' || c == '\t') { /* end of flag group */ 441 *newbits = tmp; 442 continue; 443 } 444 445 p++; 446 goto newflag; 447 } 448 449 /* save the new flag set */ 450 bcopy(tmpflags, &pmc_debugflags, sizeof(pmc_debugflags)); 451 452 done: 453 FREE(tmpflags, M_PMC); 454 return error; 455 } 456 457 static int 458 pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS) 459 { 460 char *fence, *newstr; 461 int error; 462 unsigned int n; 463 464 (void) arg1; (void) arg2; /* unused parameters */ 465 466 n = sizeof(pmc_debugstr); 467 MALLOC(newstr, char *, n, M_PMC, M_ZERO|M_WAITOK); 468 (void) strlcpy(newstr, pmc_debugstr, n); 469 470 error = sysctl_handle_string(oidp, newstr, n, req); 471 472 /* if there is a new string, parse and copy it */ 473 if (error == 0 && req->newptr != NULL) { 474 fence = newstr + (n < req->newlen ? n : req->newlen + 1); 475 if ((error = pmc_debugflags_parse(newstr, fence)) == 0) 476 (void) strlcpy(pmc_debugstr, newstr, 477 sizeof(pmc_debugstr)); 478 } 479 480 FREE(newstr, M_PMC); 481 482 return error; 483 } 484 #endif 485 486 /* 487 * Concurrency Control 488 * 489 * The driver manages the following data structures: 490 * 491 * - target process descriptors, one per target process 492 * - owner process descriptors (and attached lists), one per owner process 493 * - lookup hash tables for owner and target processes 494 * - PMC descriptors (and attached lists) 495 * - per-cpu hardware state 496 * - the 'hook' variable through which the kernel calls into 497 * this module 498 * - the machine hardware state (managed by the MD layer) 499 * 500 * These data structures are accessed from: 501 * 502 * - thread context-switch code 503 * - interrupt handlers (possibly on multiple cpus) 504 * - kernel threads on multiple cpus running on behalf of user 505 * processes doing system calls 506 * - this driver's private kernel threads 507 * 508 * = Locks and Locking strategy = 509 * 510 * The driver uses four locking strategies for its operation: 511 * 512 * - The global SX lock "pmc_sx" is used to protect internal 513 * data structures. 514 * 515 * Calls into the module by syscall() start with this lock being 516 * held in exclusive mode. Depending on the requested operation, 517 * the lock may be downgraded to 'shared' mode to allow more 518 * concurrent readers into the module. Calls into the module from 519 * other parts of the kernel acquire the lock in shared mode. 520 * 521 * This SX lock is held in exclusive mode for any operations that 522 * modify the linkages between the driver's internal data structures. 523 * 524 * The 'pmc_hook' function pointer is also protected by this lock. 525 * It is only examined with the sx lock held in exclusive mode. The 526 * kernel module is allowed to be unloaded only with the sx lock held 527 * in exclusive mode. In normal syscall handling, after acquiring the 528 * pmc_sx lock we first check that 'pmc_hook' is non-null before 529 * proceeding. This prevents races between the thread unloading the module 530 * and other threads seeking to use the module. 531 * 532 * - Lookups of target process structures and owner process structures 533 * cannot use the global "pmc_sx" SX lock because these lookups need 534 * to happen during context switches and in other critical sections 535 * where sleeping is not allowed. We protect these lookup tables 536 * with their own private spin-mutexes, "pmc_processhash_mtx" and 537 * "pmc_ownerhash_mtx". 538 * 539 * - Interrupt handlers work in a lock free manner. At interrupt 540 * time, handlers look at the PMC pointer (phw->phw_pmc) configured 541 * when the PMC was started. If this pointer is NULL, the interrupt 542 * is ignored after updating driver statistics. We ensure that this 543 * pointer is set (using an atomic operation if necessary) before the 544 * PMC hardware is started. Conversely, this pointer is unset atomically 545 * only after the PMC hardware is stopped. 546 * 547 * We ensure that everything needed for the operation of an 548 * interrupt handler is available without it needing to acquire any 549 * locks. We also ensure that a PMC's software state is destroyed only 550 * after the PMC is taken off hardware (on all CPUs). 551 * 552 * - Context-switch handling with process-private PMCs needs more 553 * care. 554 * 555 * A given process may be the target of multiple PMCs. For example, 556 * PMCATTACH and PMCDETACH may be requested by a process on one CPU 557 * while the target process is running on another. A PMC could also 558 * be getting released because its owner is exiting. We tackle 559 * these situations in the following manner: 560 * 561 * - each target process structure 'pmc_process' has an array 562 * of 'struct pmc *' pointers, one for each hardware PMC. 563 * 564 * - At context switch IN time, each "target" PMC in RUNNING state 565 * gets started on hardware and a pointer to each PMC is copied into 566 * the per-cpu phw array. The 'runcount' for the PMC is 567 * incremented. 568 * 569 * - At context switch OUT time, all process-virtual PMCs are stopped 570 * on hardware. The saved value is added to the PMCs value field 571 * only if the PMC is in a non-deleted state (the PMCs state could 572 * have changed during the current time slice). 573 * 574 * Note that since in-between a switch IN on a processor and a switch 575 * OUT, the PMC could have been released on another CPU. Therefore 576 * context switch OUT always looks at the hardware state to turn 577 * OFF PMCs and will update a PMC's saved value only if reachable 578 * from the target process record. 579 * 580 * - OP PMCRELEASE could be called on a PMC at any time (the PMC could 581 * be attached to many processes at the time of the call and could 582 * be active on multiple CPUs). 583 * 584 * We prevent further scheduling of the PMC by marking it as in 585 * state 'DELETED'. If the runcount of the PMC is non-zero then 586 * this PMC is currently running on a CPU somewhere. The thread 587 * doing the PMCRELEASE operation waits by repeatedly doing a 588 * pause() till the runcount comes to zero. 589 * 590 * The contents of a PMC descriptor (struct pmc) are protected using 591 * a spin-mutex. In order to save space, we use a mutex pool. 592 * 593 * In terms of lock types used by witness(4), we use: 594 * - Type "pmc-sx", used by the global SX lock. 595 * - Type "pmc-sleep", for sleep mutexes used by logger threads. 596 * - Type "pmc-per-proc", for protecting PMC owner descriptors. 597 * - Type "pmc-leaf", used for all other spin mutexes. 598 */ 599 600 /* 601 * save the cpu binding of the current kthread 602 */ 603 604 static void 605 pmc_save_cpu_binding(struct pmc_binding *pb) 606 { 607 PMCDBG(CPU,BND,2, "%s", "save-cpu"); 608 thread_lock(curthread); 609 pb->pb_bound = sched_is_bound(curthread); 610 pb->pb_cpu = curthread->td_oncpu; 611 thread_unlock(curthread); 612 PMCDBG(CPU,BND,2, "save-cpu cpu=%d", pb->pb_cpu); 613 } 614 615 /* 616 * restore the cpu binding of the current thread 617 */ 618 619 static void 620 pmc_restore_cpu_binding(struct pmc_binding *pb) 621 { 622 PMCDBG(CPU,BND,2, "restore-cpu curcpu=%d restore=%d", 623 curthread->td_oncpu, pb->pb_cpu); 624 thread_lock(curthread); 625 if (pb->pb_bound) 626 sched_bind(curthread, pb->pb_cpu); 627 else 628 sched_unbind(curthread); 629 thread_unlock(curthread); 630 PMCDBG(CPU,BND,2, "%s", "restore-cpu done"); 631 } 632 633 /* 634 * move execution over the specified cpu and bind it there. 635 */ 636 637 static void 638 pmc_select_cpu(int cpu) 639 { 640 KASSERT(cpu >= 0 && cpu < mp_ncpus, 641 ("[pmc,%d] bad cpu number %d", __LINE__, cpu)); 642 643 /* never move to a disabled CPU */ 644 KASSERT(pmc_cpu_is_disabled(cpu) == 0, ("[pmc,%d] selecting " 645 "disabled CPU %d", __LINE__, cpu)); 646 647 PMCDBG(CPU,SEL,2, "select-cpu cpu=%d", cpu); 648 thread_lock(curthread); 649 sched_bind(curthread, cpu); 650 thread_unlock(curthread); 651 652 KASSERT(curthread->td_oncpu == cpu, 653 ("[pmc,%d] CPU not bound [cpu=%d, curr=%d]", __LINE__, 654 cpu, curthread->td_oncpu)); 655 656 PMCDBG(CPU,SEL,2, "select-cpu cpu=%d ok", cpu); 657 } 658 659 /* 660 * Force a context switch. 661 * 662 * We do this by pause'ing for 1 tick -- invoking mi_switch() is not 663 * guaranteed to force a context switch. 664 */ 665 666 static void 667 pmc_force_context_switch(void) 668 { 669 670 pause("pmcctx", 1); 671 } 672 673 /* 674 * Get the file name for an executable. This is a simple wrapper 675 * around vn_fullpath(9). 676 */ 677 678 static void 679 pmc_getfilename(struct vnode *v, char **fullpath, char **freepath) 680 { 681 682 *fullpath = "unknown"; 683 *freepath = NULL; 684 vn_lock(v, LK_CANRECURSE | LK_EXCLUSIVE | LK_RETRY); 685 vn_fullpath(curthread, v, fullpath, freepath); 686 VOP_UNLOCK(v, 0); 687 } 688 689 /* 690 * remove an process owning PMCs 691 */ 692 693 void 694 pmc_remove_owner(struct pmc_owner *po) 695 { 696 struct pmc *pm, *tmp; 697 698 sx_assert(&pmc_sx, SX_XLOCKED); 699 700 PMCDBG(OWN,ORM,1, "remove-owner po=%p", po); 701 702 /* Remove descriptor from the owner hash table */ 703 LIST_REMOVE(po, po_next); 704 705 /* release all owned PMC descriptors */ 706 LIST_FOREACH_SAFE(pm, &po->po_pmcs, pm_next, tmp) { 707 PMCDBG(OWN,ORM,2, "pmc=%p", pm); 708 KASSERT(pm->pm_owner == po, 709 ("[pmc,%d] owner %p != po %p", __LINE__, pm->pm_owner, po)); 710 711 pmc_release_pmc_descriptor(pm); /* will unlink from the list */ 712 } 713 714 KASSERT(po->po_sscount == 0, 715 ("[pmc,%d] SS count not zero", __LINE__)); 716 KASSERT(LIST_EMPTY(&po->po_pmcs), 717 ("[pmc,%d] PMC list not empty", __LINE__)); 718 719 /* de-configure the log file if present */ 720 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 721 pmclog_deconfigure_log(po); 722 } 723 724 /* 725 * remove an owner process record if all conditions are met. 726 */ 727 728 static void 729 pmc_maybe_remove_owner(struct pmc_owner *po) 730 { 731 732 PMCDBG(OWN,OMR,1, "maybe-remove-owner po=%p", po); 733 734 /* 735 * Remove owner record if 736 * - this process does not own any PMCs 737 * - this process has not allocated a system-wide sampling buffer 738 */ 739 740 if (LIST_EMPTY(&po->po_pmcs) && 741 ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0)) { 742 pmc_remove_owner(po); 743 pmc_destroy_owner_descriptor(po); 744 } 745 } 746 747 /* 748 * Add an association between a target process and a PMC. 749 */ 750 751 static void 752 pmc_link_target_process(struct pmc *pm, struct pmc_process *pp) 753 { 754 int ri; 755 struct pmc_target *pt; 756 757 sx_assert(&pmc_sx, SX_XLOCKED); 758 759 KASSERT(pm != NULL && pp != NULL, 760 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 761 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 762 ("[pmc,%d] Attaching a non-process-virtual pmc=%p to pid=%d", 763 __LINE__, pm, pp->pp_proc->p_pid)); 764 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt < ((int) md->pmd_npmc - 1), 765 ("[pmc,%d] Illegal reference count %d for process record %p", 766 __LINE__, pp->pp_refcnt, (void *) pp)); 767 768 ri = PMC_TO_ROWINDEX(pm); 769 770 PMCDBG(PRC,TLK,1, "link-target pmc=%p ri=%d pmc-process=%p", 771 pm, ri, pp); 772 773 #ifdef DEBUG 774 LIST_FOREACH(pt, &pm->pm_targets, pt_next) 775 if (pt->pt_process == pp) 776 KASSERT(0, ("[pmc,%d] pp %p already in pmc %p targets", 777 __LINE__, pp, pm)); 778 #endif 779 780 MALLOC(pt, struct pmc_target *, sizeof(struct pmc_target), 781 M_PMC, M_ZERO|M_WAITOK); 782 783 pt->pt_process = pp; 784 785 LIST_INSERT_HEAD(&pm->pm_targets, pt, pt_next); 786 787 atomic_store_rel_ptr((uintptr_t *)&pp->pp_pmcs[ri].pp_pmc, 788 (uintptr_t)pm); 789 790 if (pm->pm_owner->po_owner == pp->pp_proc) 791 pm->pm_flags |= PMC_F_ATTACHED_TO_OWNER; 792 793 /* 794 * Initialize the per-process values at this row index. 795 */ 796 pp->pp_pmcs[ri].pp_pmcval = PMC_TO_MODE(pm) == PMC_MODE_TS ? 797 pm->pm_sc.pm_reloadcount : 0; 798 799 pp->pp_refcnt++; 800 801 } 802 803 /* 804 * Removes the association between a target process and a PMC. 805 */ 806 807 static void 808 pmc_unlink_target_process(struct pmc *pm, struct pmc_process *pp) 809 { 810 int ri; 811 struct proc *p; 812 struct pmc_target *ptgt; 813 814 sx_assert(&pmc_sx, SX_XLOCKED); 815 816 KASSERT(pm != NULL && pp != NULL, 817 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 818 819 KASSERT(pp->pp_refcnt >= 1 && pp->pp_refcnt < (int) md->pmd_npmc, 820 ("[pmc,%d] Illegal ref count %d on process record %p", 821 __LINE__, pp->pp_refcnt, (void *) pp)); 822 823 ri = PMC_TO_ROWINDEX(pm); 824 825 PMCDBG(PRC,TUL,1, "unlink-target pmc=%p ri=%d pmc-process=%p", 826 pm, ri, pp); 827 828 KASSERT(pp->pp_pmcs[ri].pp_pmc == pm, 829 ("[pmc,%d] PMC ri %d mismatch pmc %p pp->[ri] %p", __LINE__, 830 ri, pm, pp->pp_pmcs[ri].pp_pmc)); 831 832 pp->pp_pmcs[ri].pp_pmc = NULL; 833 pp->pp_pmcs[ri].pp_pmcval = (pmc_value_t) 0; 834 835 /* Remove owner-specific flags */ 836 if (pm->pm_owner->po_owner == pp->pp_proc) { 837 pp->pp_flags &= ~PMC_PP_ENABLE_MSR_ACCESS; 838 pm->pm_flags &= ~PMC_F_ATTACHED_TO_OWNER; 839 } 840 841 pp->pp_refcnt--; 842 843 /* Remove the target process from the PMC structure */ 844 LIST_FOREACH(ptgt, &pm->pm_targets, pt_next) 845 if (ptgt->pt_process == pp) 846 break; 847 848 KASSERT(ptgt != NULL, ("[pmc,%d] process %p (pp: %p) not found " 849 "in pmc %p", __LINE__, pp->pp_proc, pp, pm)); 850 851 LIST_REMOVE(ptgt, pt_next); 852 FREE(ptgt, M_PMC); 853 854 /* if the PMC now lacks targets, send the owner a SIGIO */ 855 if (LIST_EMPTY(&pm->pm_targets)) { 856 p = pm->pm_owner->po_owner; 857 PROC_LOCK(p); 858 psignal(p, SIGIO); 859 PROC_UNLOCK(p); 860 861 PMCDBG(PRC,SIG,2, "signalling proc=%p signal=%d", p, 862 SIGIO); 863 } 864 } 865 866 /* 867 * Check if PMC 'pm' may be attached to target process 't'. 868 */ 869 870 static int 871 pmc_can_attach(struct pmc *pm, struct proc *t) 872 { 873 struct proc *o; /* pmc owner */ 874 struct ucred *oc, *tc; /* owner, target credentials */ 875 int decline_attach, i; 876 877 /* 878 * A PMC's owner can always attach that PMC to itself. 879 */ 880 881 if ((o = pm->pm_owner->po_owner) == t) 882 return 0; 883 884 PROC_LOCK(o); 885 oc = o->p_ucred; 886 crhold(oc); 887 PROC_UNLOCK(o); 888 889 PROC_LOCK(t); 890 tc = t->p_ucred; 891 crhold(tc); 892 PROC_UNLOCK(t); 893 894 /* 895 * The effective uid of the PMC owner should match at least one 896 * of the {effective,real,saved} uids of the target process. 897 */ 898 899 decline_attach = oc->cr_uid != tc->cr_uid && 900 oc->cr_uid != tc->cr_svuid && 901 oc->cr_uid != tc->cr_ruid; 902 903 /* 904 * Every one of the target's group ids, must be in the owner's 905 * group list. 906 */ 907 for (i = 0; !decline_attach && i < tc->cr_ngroups; i++) 908 decline_attach = !groupmember(tc->cr_groups[i], oc); 909 910 /* check the read and saved gids too */ 911 if (decline_attach == 0) 912 decline_attach = !groupmember(tc->cr_rgid, oc) || 913 !groupmember(tc->cr_svgid, oc); 914 915 crfree(tc); 916 crfree(oc); 917 918 return !decline_attach; 919 } 920 921 /* 922 * Attach a process to a PMC. 923 */ 924 925 static int 926 pmc_attach_one_process(struct proc *p, struct pmc *pm) 927 { 928 int ri; 929 char *fullpath, *freepath; 930 struct pmc_process *pp; 931 932 sx_assert(&pmc_sx, SX_XLOCKED); 933 934 PMCDBG(PRC,ATT,2, "attach-one pm=%p ri=%d proc=%p (%d, %s)", pm, 935 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 936 937 /* 938 * Locate the process descriptor corresponding to process 'p', 939 * allocating space as needed. 940 * 941 * Verify that rowindex 'pm_rowindex' is free in the process 942 * descriptor. 943 * 944 * If not, allocate space for a descriptor and link the 945 * process descriptor and PMC. 946 */ 947 ri = PMC_TO_ROWINDEX(pm); 948 949 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_ALLOCATE)) == NULL) 950 return ENOMEM; 951 952 if (pp->pp_pmcs[ri].pp_pmc == pm) /* already present at slot [ri] */ 953 return EEXIST; 954 955 if (pp->pp_pmcs[ri].pp_pmc != NULL) 956 return EBUSY; 957 958 pmc_link_target_process(pm, pp); 959 960 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) && 961 (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) == 0) 962 pm->pm_flags |= PMC_F_NEEDS_LOGFILE; 963 964 pm->pm_flags |= PMC_F_ATTACH_DONE; /* mark as attached */ 965 966 /* issue an attach event to a configured log file */ 967 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) { 968 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 969 if (p->p_flag & P_KTHREAD) { 970 fullpath = kernelname; 971 freepath = NULL; 972 } else 973 pmclog_process_pmcattach(pm, p->p_pid, fullpath); 974 if (freepath) 975 FREE(freepath, M_TEMP); 976 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 977 pmc_log_process_mappings(pm->pm_owner, p); 978 } 979 /* mark process as using HWPMCs */ 980 PROC_LOCK(p); 981 p->p_flag |= P_HWPMC; 982 PROC_UNLOCK(p); 983 984 return 0; 985 } 986 987 /* 988 * Attach a process and optionally its children 989 */ 990 991 static int 992 pmc_attach_process(struct proc *p, struct pmc *pm) 993 { 994 int error; 995 struct proc *top; 996 997 sx_assert(&pmc_sx, SX_XLOCKED); 998 999 PMCDBG(PRC,ATT,1, "attach pm=%p ri=%d proc=%p (%d, %s)", pm, 1000 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1001 1002 1003 /* 1004 * If this PMC successfully allowed a GETMSR operation 1005 * in the past, disallow further ATTACHes. 1006 */ 1007 1008 if ((pm->pm_flags & PMC_PP_ENABLE_MSR_ACCESS) != 0) 1009 return EPERM; 1010 1011 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 1012 return pmc_attach_one_process(p, pm); 1013 1014 /* 1015 * Traverse all child processes, attaching them to 1016 * this PMC. 1017 */ 1018 1019 sx_slock(&proctree_lock); 1020 1021 top = p; 1022 1023 for (;;) { 1024 if ((error = pmc_attach_one_process(p, pm)) != 0) 1025 break; 1026 if (!LIST_EMPTY(&p->p_children)) 1027 p = LIST_FIRST(&p->p_children); 1028 else for (;;) { 1029 if (p == top) 1030 goto done; 1031 if (LIST_NEXT(p, p_sibling)) { 1032 p = LIST_NEXT(p, p_sibling); 1033 break; 1034 } 1035 p = p->p_pptr; 1036 } 1037 } 1038 1039 if (error) 1040 (void) pmc_detach_process(top, pm); 1041 1042 done: 1043 sx_sunlock(&proctree_lock); 1044 return error; 1045 } 1046 1047 /* 1048 * Detach a process from a PMC. If there are no other PMCs tracking 1049 * this process, remove the process structure from its hash table. If 1050 * 'flags' contains PMC_FLAG_REMOVE, then free the process structure. 1051 */ 1052 1053 static int 1054 pmc_detach_one_process(struct proc *p, struct pmc *pm, int flags) 1055 { 1056 int ri; 1057 struct pmc_process *pp; 1058 1059 sx_assert(&pmc_sx, SX_XLOCKED); 1060 1061 KASSERT(pm != NULL, 1062 ("[pmc,%d] null pm pointer", __LINE__)); 1063 1064 ri = PMC_TO_ROWINDEX(pm); 1065 1066 PMCDBG(PRC,ATT,2, "detach-one pm=%p ri=%d proc=%p (%d, %s) flags=0x%x", 1067 pm, ri, p, p->p_pid, p->p_comm, flags); 1068 1069 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) 1070 return ESRCH; 1071 1072 if (pp->pp_pmcs[ri].pp_pmc != pm) 1073 return EINVAL; 1074 1075 pmc_unlink_target_process(pm, pp); 1076 1077 /* Issue a detach entry if a log file is configured */ 1078 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) 1079 pmclog_process_pmcdetach(pm, p->p_pid); 1080 1081 /* 1082 * If there are no PMCs targetting this process, we remove its 1083 * descriptor from the target hash table and unset the P_HWPMC 1084 * flag in the struct proc. 1085 */ 1086 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt < (int) md->pmd_npmc, 1087 ("[pmc,%d] Illegal refcnt %d for process struct %p", 1088 __LINE__, pp->pp_refcnt, pp)); 1089 1090 if (pp->pp_refcnt != 0) /* still a target of some PMC */ 1091 return 0; 1092 1093 pmc_remove_process_descriptor(pp); 1094 1095 if (flags & PMC_FLAG_REMOVE) 1096 FREE(pp, M_PMC); 1097 1098 PROC_LOCK(p); 1099 p->p_flag &= ~P_HWPMC; 1100 PROC_UNLOCK(p); 1101 1102 return 0; 1103 } 1104 1105 /* 1106 * Detach a process and optionally its descendants from a PMC. 1107 */ 1108 1109 static int 1110 pmc_detach_process(struct proc *p, struct pmc *pm) 1111 { 1112 struct proc *top; 1113 1114 sx_assert(&pmc_sx, SX_XLOCKED); 1115 1116 PMCDBG(PRC,ATT,1, "detach pm=%p ri=%d proc=%p (%d, %s)", pm, 1117 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1118 1119 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 1120 return pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); 1121 1122 /* 1123 * Traverse all children, detaching them from this PMC. We 1124 * ignore errors since we could be detaching a PMC from a 1125 * partially attached proc tree. 1126 */ 1127 1128 sx_slock(&proctree_lock); 1129 1130 top = p; 1131 1132 for (;;) { 1133 (void) pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); 1134 1135 if (!LIST_EMPTY(&p->p_children)) 1136 p = LIST_FIRST(&p->p_children); 1137 else for (;;) { 1138 if (p == top) 1139 goto done; 1140 if (LIST_NEXT(p, p_sibling)) { 1141 p = LIST_NEXT(p, p_sibling); 1142 break; 1143 } 1144 p = p->p_pptr; 1145 } 1146 } 1147 1148 done: 1149 sx_sunlock(&proctree_lock); 1150 1151 if (LIST_EMPTY(&pm->pm_targets)) 1152 pm->pm_flags &= ~PMC_F_ATTACH_DONE; 1153 1154 return 0; 1155 } 1156 1157 1158 /* 1159 * Thread context switch IN 1160 */ 1161 1162 static void 1163 pmc_process_csw_in(struct thread *td) 1164 { 1165 int cpu; 1166 unsigned int ri; 1167 struct pmc *pm; 1168 struct proc *p; 1169 struct pmc_cpu *pc; 1170 struct pmc_hw *phw; 1171 struct pmc_process *pp; 1172 pmc_value_t newvalue; 1173 1174 p = td->td_proc; 1175 1176 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE)) == NULL) 1177 return; 1178 1179 KASSERT(pp->pp_proc == td->td_proc, 1180 ("[pmc,%d] not my thread state", __LINE__)); 1181 1182 critical_enter(); /* no preemption from this point */ 1183 1184 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1185 1186 PMCDBG(CSW,SWI,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1187 p->p_pid, p->p_comm, pp); 1188 1189 KASSERT(cpu >= 0 && cpu < mp_ncpus, 1190 ("[pmc,%d] wierd CPU id %d", __LINE__, cpu)); 1191 1192 pc = pmc_pcpu[cpu]; 1193 1194 for (ri = 0; ri < md->pmd_npmc; ri++) { 1195 1196 if ((pm = pp->pp_pmcs[ri].pp_pmc) == NULL) 1197 continue; 1198 1199 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 1200 ("[pmc,%d] Target PMC in non-virtual mode (%d)", 1201 __LINE__, PMC_TO_MODE(pm))); 1202 1203 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1204 ("[pmc,%d] Row index mismatch pmc %d != ri %d", 1205 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1206 1207 /* 1208 * Only PMCs that are marked as 'RUNNING' need 1209 * be placed on hardware. 1210 */ 1211 1212 if (pm->pm_state != PMC_STATE_RUNNING) 1213 continue; 1214 1215 /* increment PMC runcount */ 1216 atomic_add_rel_32(&pm->pm_runcount, 1); 1217 1218 /* configure the HWPMC we are going to use. */ 1219 md->pmd_config_pmc(cpu, ri, pm); 1220 1221 phw = pc->pc_hwpmcs[ri]; 1222 1223 KASSERT(phw != NULL, 1224 ("[pmc,%d] null hw pointer", __LINE__)); 1225 1226 KASSERT(phw->phw_pmc == pm, 1227 ("[pmc,%d] hw->pmc %p != pmc %p", __LINE__, 1228 phw->phw_pmc, pm)); 1229 1230 /* 1231 * Write out saved value and start the PMC. 1232 * 1233 * Sampling PMCs use a per-process value, while 1234 * counting mode PMCs use a per-pmc value that is 1235 * inherited across descendants. 1236 */ 1237 if (PMC_TO_MODE(pm) == PMC_MODE_TS) { 1238 mtx_pool_lock_spin(pmc_mtxpool, pm); 1239 newvalue = PMC_PCPU_SAVED(cpu,ri) = 1240 pp->pp_pmcs[ri].pp_pmcval; 1241 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1242 } else { 1243 KASSERT(PMC_TO_MODE(pm) == PMC_MODE_TC, 1244 ("[pmc,%d] illegal mode=%d", __LINE__, 1245 PMC_TO_MODE(pm))); 1246 mtx_pool_lock_spin(pmc_mtxpool, pm); 1247 newvalue = PMC_PCPU_SAVED(cpu, ri) = 1248 pm->pm_gv.pm_savedvalue; 1249 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1250 } 1251 1252 PMCDBG(CSW,SWI,1,"cpu=%d ri=%d new=%jd", cpu, ri, newvalue); 1253 1254 md->pmd_write_pmc(cpu, ri, newvalue); 1255 md->pmd_start_pmc(cpu, ri); 1256 } 1257 1258 /* 1259 * perform any other architecture/cpu dependent thread 1260 * switch-in actions. 1261 */ 1262 1263 (void) (*md->pmd_switch_in)(pc, pp); 1264 1265 critical_exit(); 1266 1267 } 1268 1269 /* 1270 * Thread context switch OUT. 1271 */ 1272 1273 static void 1274 pmc_process_csw_out(struct thread *td) 1275 { 1276 int cpu; 1277 enum pmc_mode mode; 1278 unsigned int ri; 1279 struct pmc *pm; 1280 struct proc *p; 1281 struct pmc_cpu *pc; 1282 struct pmc_process *pp; 1283 int64_t tmp; 1284 pmc_value_t newvalue; 1285 1286 /* 1287 * Locate our process descriptor; this may be NULL if 1288 * this process is exiting and we have already removed 1289 * the process from the target process table. 1290 * 1291 * Note that due to kernel preemption, multiple 1292 * context switches may happen while the process is 1293 * exiting. 1294 * 1295 * Note also that if the target process cannot be 1296 * found we still need to deconfigure any PMCs that 1297 * are currently running on hardware. 1298 */ 1299 1300 p = td->td_proc; 1301 pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE); 1302 1303 /* 1304 * save PMCs 1305 */ 1306 1307 critical_enter(); 1308 1309 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1310 1311 PMCDBG(CSW,SWO,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1312 p->p_pid, p->p_comm, pp); 1313 1314 KASSERT(cpu >= 0 && cpu < mp_ncpus, 1315 ("[pmc,%d wierd CPU id %d", __LINE__, cpu)); 1316 1317 pc = pmc_pcpu[cpu]; 1318 1319 /* 1320 * When a PMC gets unlinked from a target PMC, it will 1321 * be removed from the target's pp_pmc[] array. 1322 * 1323 * However, on a MP system, the target could have been 1324 * executing on another CPU at the time of the unlink. 1325 * So, at context switch OUT time, we need to look at 1326 * the hardware to determine if a PMC is scheduled on 1327 * it. 1328 */ 1329 1330 for (ri = 0; ri < md->pmd_npmc; ri++) { 1331 1332 pm = NULL; 1333 (void) (*md->pmd_get_config)(cpu, ri, &pm); 1334 1335 if (pm == NULL) /* nothing at this row index */ 1336 continue; 1337 1338 mode = PMC_TO_MODE(pm); 1339 if (!PMC_IS_VIRTUAL_MODE(mode)) 1340 continue; /* not a process virtual PMC */ 1341 1342 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1343 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 1344 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1345 1346 /* Stop hardware if not already stopped */ 1347 if (pm->pm_stalled == 0) 1348 md->pmd_stop_pmc(cpu, ri); 1349 1350 /* reduce this PMC's runcount */ 1351 atomic_subtract_rel_32(&pm->pm_runcount, 1); 1352 1353 /* 1354 * If this PMC is associated with this process, 1355 * save the reading. 1356 */ 1357 1358 if (pp != NULL && pp->pp_pmcs[ri].pp_pmc != NULL) { 1359 1360 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 1361 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", __LINE__, 1362 pm, ri, pp->pp_pmcs[ri].pp_pmc)); 1363 1364 KASSERT(pp->pp_refcnt > 0, 1365 ("[pmc,%d] pp refcnt = %d", __LINE__, 1366 pp->pp_refcnt)); 1367 1368 md->pmd_read_pmc(cpu, ri, &newvalue); 1369 1370 tmp = newvalue - PMC_PCPU_SAVED(cpu,ri); 1371 1372 PMCDBG(CSW,SWI,1,"cpu=%d ri=%d tmp=%jd", cpu, ri, 1373 tmp); 1374 1375 if (mode == PMC_MODE_TS) { 1376 1377 /* 1378 * For sampling process-virtual PMCs, 1379 * we expect the count to be 1380 * decreasing as the 'value' 1381 * programmed into the PMC is the 1382 * number of events to be seen till 1383 * the next sampling interrupt. 1384 */ 1385 if (tmp < 0) 1386 tmp += pm->pm_sc.pm_reloadcount; 1387 mtx_pool_lock_spin(pmc_mtxpool, pm); 1388 pp->pp_pmcs[ri].pp_pmcval -= tmp; 1389 if ((int64_t) pp->pp_pmcs[ri].pp_pmcval < 0) 1390 pp->pp_pmcs[ri].pp_pmcval += 1391 pm->pm_sc.pm_reloadcount; 1392 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1393 1394 } else { 1395 1396 /* 1397 * For counting process-virtual PMCs, 1398 * we expect the count to be 1399 * increasing monotonically, modulo a 64 1400 * bit wraparound. 1401 */ 1402 KASSERT((int64_t) tmp >= 0, 1403 ("[pmc,%d] negative increment cpu=%d " 1404 "ri=%d newvalue=%jx saved=%jx " 1405 "incr=%jx", __LINE__, cpu, ri, 1406 newvalue, PMC_PCPU_SAVED(cpu,ri), tmp)); 1407 1408 mtx_pool_lock_spin(pmc_mtxpool, pm); 1409 pm->pm_gv.pm_savedvalue += tmp; 1410 pp->pp_pmcs[ri].pp_pmcval += tmp; 1411 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1412 1413 if (pm->pm_flags & PMC_F_LOG_PROCCSW) 1414 pmclog_process_proccsw(pm, pp, tmp); 1415 } 1416 } 1417 1418 /* mark hardware as free */ 1419 md->pmd_config_pmc(cpu, ri, NULL); 1420 } 1421 1422 /* 1423 * perform any other architecture/cpu dependent thread 1424 * switch out functions. 1425 */ 1426 1427 (void) (*md->pmd_switch_out)(pc, pp); 1428 1429 critical_exit(); 1430 } 1431 1432 /* 1433 * Log a KLD operation. 1434 */ 1435 1436 static void 1437 pmc_process_kld_load(struct pmckern_map_in *pkm) 1438 { 1439 struct pmc_owner *po; 1440 1441 sx_assert(&pmc_sx, SX_LOCKED); 1442 1443 /* 1444 * Notify owners of system sampling PMCs about KLD operations. 1445 */ 1446 1447 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1448 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1449 pmclog_process_map_in(po, (pid_t) -1, pkm->pm_address, 1450 (char *) pkm->pm_file); 1451 1452 /* 1453 * TODO: Notify owners of (all) process-sampling PMCs too. 1454 */ 1455 1456 return; 1457 } 1458 1459 static void 1460 pmc_process_kld_unload(struct pmckern_map_out *pkm) 1461 { 1462 struct pmc_owner *po; 1463 1464 sx_assert(&pmc_sx, SX_LOCKED); 1465 1466 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1467 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1468 pmclog_process_map_out(po, (pid_t) -1, 1469 pkm->pm_address, pkm->pm_address + pkm->pm_size); 1470 1471 /* 1472 * TODO: Notify owners of process-sampling PMCs. 1473 */ 1474 } 1475 1476 /* 1477 * A mapping change for a process. 1478 */ 1479 1480 static void 1481 pmc_process_mmap(struct thread *td, struct pmckern_map_in *pkm) 1482 { 1483 int ri; 1484 pid_t pid; 1485 char *fullpath, *freepath; 1486 const struct pmc *pm; 1487 struct pmc_owner *po; 1488 const struct pmc_process *pp; 1489 1490 freepath = fullpath = NULL; 1491 pmc_getfilename((struct vnode *) pkm->pm_file, &fullpath, &freepath); 1492 1493 pid = td->td_proc->p_pid; 1494 1495 /* Inform owners of all system-wide sampling PMCs. */ 1496 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1497 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1498 pmclog_process_map_in(po, pid, pkm->pm_address, fullpath); 1499 1500 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1501 goto done; 1502 1503 /* 1504 * Inform sampling PMC owners tracking this process. 1505 */ 1506 for (ri = 0; ri < md->pmd_npmc; ri++) 1507 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1508 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1509 pmclog_process_map_in(pm->pm_owner, 1510 pid, pkm->pm_address, fullpath); 1511 1512 done: 1513 if (freepath) 1514 FREE(freepath, M_TEMP); 1515 } 1516 1517 1518 /* 1519 * Log an munmap request. 1520 */ 1521 1522 static void 1523 pmc_process_munmap(struct thread *td, struct pmckern_map_out *pkm) 1524 { 1525 int ri; 1526 pid_t pid; 1527 struct pmc_owner *po; 1528 const struct pmc *pm; 1529 const struct pmc_process *pp; 1530 1531 pid = td->td_proc->p_pid; 1532 1533 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1534 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1535 pmclog_process_map_out(po, pid, pkm->pm_address, 1536 pkm->pm_address + pkm->pm_size); 1537 1538 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1539 return; 1540 1541 for (ri = 0; ri < md->pmd_npmc; ri++) 1542 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1543 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1544 pmclog_process_map_out(pm->pm_owner, pid, 1545 pkm->pm_address, pkm->pm_address + pkm->pm_size); 1546 } 1547 1548 /* 1549 * Log mapping information about the kernel. 1550 */ 1551 1552 static void 1553 pmc_log_kernel_mappings(struct pmc *pm) 1554 { 1555 struct pmc_owner *po; 1556 struct pmckern_map_in *km, *kmbase; 1557 1558 sx_assert(&pmc_sx, SX_LOCKED); 1559 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 1560 ("[pmc,%d] non-sampling PMC (%p) desires mapping information", 1561 __LINE__, (void *) pm)); 1562 1563 po = pm->pm_owner; 1564 1565 if (po->po_flags & PMC_PO_INITIAL_MAPPINGS_DONE) 1566 return; 1567 1568 /* 1569 * Log the current set of kernel modules. 1570 */ 1571 kmbase = linker_hwpmc_list_objects(); 1572 for (km = kmbase; km->pm_file != NULL; km++) { 1573 PMCDBG(LOG,REG,1,"%s %p", (char *) km->pm_file, 1574 (void *) km->pm_address); 1575 pmclog_process_map_in(po, (pid_t) -1, km->pm_address, 1576 km->pm_file); 1577 } 1578 FREE(kmbase, M_LINKER); 1579 1580 po->po_flags |= PMC_PO_INITIAL_MAPPINGS_DONE; 1581 } 1582 1583 /* 1584 * Log the mappings for a single process. 1585 */ 1586 1587 static void 1588 pmc_log_process_mappings(struct pmc_owner *po, struct proc *p) 1589 { 1590 } 1591 1592 /* 1593 * Log mappings for all processes in the system. 1594 */ 1595 1596 static void 1597 pmc_log_all_process_mappings(struct pmc_owner *po) 1598 { 1599 struct proc *p, *top; 1600 1601 sx_assert(&pmc_sx, SX_XLOCKED); 1602 1603 if ((p = pfind(1)) == NULL) 1604 panic("[pmc,%d] Cannot find init", __LINE__); 1605 1606 PROC_UNLOCK(p); 1607 1608 sx_slock(&proctree_lock); 1609 1610 top = p; 1611 1612 for (;;) { 1613 pmc_log_process_mappings(po, p); 1614 if (!LIST_EMPTY(&p->p_children)) 1615 p = LIST_FIRST(&p->p_children); 1616 else for (;;) { 1617 if (p == top) 1618 goto done; 1619 if (LIST_NEXT(p, p_sibling)) { 1620 p = LIST_NEXT(p, p_sibling); 1621 break; 1622 } 1623 p = p->p_pptr; 1624 } 1625 } 1626 done: 1627 sx_sunlock(&proctree_lock); 1628 } 1629 1630 /* 1631 * The 'hook' invoked from the kernel proper 1632 */ 1633 1634 1635 #ifdef DEBUG 1636 const char *pmc_hooknames[] = { 1637 /* these strings correspond to PMC_FN_* in <sys/pmckern.h> */ 1638 "", 1639 "EXEC", 1640 "CSW-IN", 1641 "CSW-OUT", 1642 "SAMPLE", 1643 "KLDLOAD", 1644 "KLDUNLOAD", 1645 "MMAP", 1646 "MUNMAP", 1647 "CALLCHAIN" 1648 }; 1649 #endif 1650 1651 static int 1652 pmc_hook_handler(struct thread *td, int function, void *arg) 1653 { 1654 1655 PMCDBG(MOD,PMH,1, "hook td=%p func=%d \"%s\" arg=%p", td, function, 1656 pmc_hooknames[function], arg); 1657 1658 switch (function) 1659 { 1660 1661 /* 1662 * Process exec() 1663 */ 1664 1665 case PMC_FN_PROCESS_EXEC: 1666 { 1667 char *fullpath, *freepath; 1668 unsigned int ri; 1669 int is_using_hwpmcs; 1670 struct pmc *pm; 1671 struct proc *p; 1672 struct pmc_owner *po; 1673 struct pmc_process *pp; 1674 struct pmckern_procexec *pk; 1675 1676 sx_assert(&pmc_sx, SX_XLOCKED); 1677 1678 p = td->td_proc; 1679 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 1680 1681 pk = (struct pmckern_procexec *) arg; 1682 1683 /* Inform owners of SS mode PMCs of the exec event. */ 1684 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1685 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1686 pmclog_process_procexec(po, PMC_ID_INVALID, 1687 p->p_pid, pk->pm_entryaddr, fullpath); 1688 1689 PROC_LOCK(p); 1690 is_using_hwpmcs = p->p_flag & P_HWPMC; 1691 PROC_UNLOCK(p); 1692 1693 if (!is_using_hwpmcs) { 1694 if (freepath) 1695 FREE(freepath, M_TEMP); 1696 break; 1697 } 1698 1699 /* 1700 * PMCs are not inherited across an exec(): remove any 1701 * PMCs that this process is the owner of. 1702 */ 1703 1704 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 1705 pmc_remove_owner(po); 1706 pmc_destroy_owner_descriptor(po); 1707 } 1708 1709 /* 1710 * If the process being exec'ed is not the target of any 1711 * PMC, we are done. 1712 */ 1713 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) { 1714 if (freepath) 1715 FREE(freepath, M_TEMP); 1716 break; 1717 } 1718 1719 /* 1720 * Log the exec event to all monitoring owners. Skip 1721 * owners who have already recieved the event because 1722 * they had system sampling PMCs active. 1723 */ 1724 for (ri = 0; ri < md->pmd_npmc; ri++) 1725 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 1726 po = pm->pm_owner; 1727 if (po->po_sscount == 0 && 1728 po->po_flags & PMC_PO_OWNS_LOGFILE) 1729 pmclog_process_procexec(po, pm->pm_id, 1730 p->p_pid, pk->pm_entryaddr, 1731 fullpath); 1732 } 1733 1734 if (freepath) 1735 FREE(freepath, M_TEMP); 1736 1737 1738 PMCDBG(PRC,EXC,1, "exec proc=%p (%d, %s) cred-changed=%d", 1739 p, p->p_pid, p->p_comm, pk->pm_credentialschanged); 1740 1741 if (pk->pm_credentialschanged == 0) /* no change */ 1742 break; 1743 1744 /* 1745 * If the newly exec()'ed process has a different credential 1746 * than before, allow it to be the target of a PMC only if 1747 * the PMC's owner has sufficient priviledge. 1748 */ 1749 1750 for (ri = 0; ri < md->pmd_npmc; ri++) 1751 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) 1752 if (pmc_can_attach(pm, td->td_proc) != 0) 1753 pmc_detach_one_process(td->td_proc, 1754 pm, PMC_FLAG_NONE); 1755 1756 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt < (int) md->pmd_npmc, 1757 ("[pmc,%d] Illegal ref count %d on pp %p", __LINE__, 1758 pp->pp_refcnt, pp)); 1759 1760 /* 1761 * If this process is no longer the target of any 1762 * PMCs, we can remove the process entry and free 1763 * up space. 1764 */ 1765 1766 if (pp->pp_refcnt == 0) { 1767 pmc_remove_process_descriptor(pp); 1768 FREE(pp, M_PMC); 1769 break; 1770 } 1771 1772 } 1773 break; 1774 1775 case PMC_FN_CSW_IN: 1776 pmc_process_csw_in(td); 1777 break; 1778 1779 case PMC_FN_CSW_OUT: 1780 pmc_process_csw_out(td); 1781 break; 1782 1783 /* 1784 * Process accumulated PC samples. 1785 * 1786 * This function is expected to be called by hardclock() for 1787 * each CPU that has accumulated PC samples. 1788 * 1789 * This function is to be executed on the CPU whose samples 1790 * are being processed. 1791 */ 1792 case PMC_FN_DO_SAMPLES: 1793 1794 /* 1795 * Clear the cpu specific bit in the CPU mask before 1796 * do the rest of the processing. If the NMI handler 1797 * gets invoked after the "atomic_clear_int()" call 1798 * below but before "pmc_process_samples()" gets 1799 * around to processing the interrupt, then we will 1800 * come back here at the next hardclock() tick (and 1801 * may find nothing to do if "pmc_process_samples()" 1802 * had already processed the interrupt). We don't 1803 * lose the interrupt sample. 1804 */ 1805 atomic_clear_int(&pmc_cpumask, (1 << PCPU_GET(cpuid))); 1806 pmc_process_samples(PCPU_GET(cpuid)); 1807 break; 1808 1809 1810 case PMC_FN_KLD_LOAD: 1811 sx_assert(&pmc_sx, SX_LOCKED); 1812 pmc_process_kld_load((struct pmckern_map_in *) arg); 1813 break; 1814 1815 case PMC_FN_KLD_UNLOAD: 1816 sx_assert(&pmc_sx, SX_LOCKED); 1817 pmc_process_kld_unload((struct pmckern_map_out *) arg); 1818 break; 1819 1820 case PMC_FN_MMAP: 1821 sx_assert(&pmc_sx, SX_LOCKED); 1822 pmc_process_mmap(td, (struct pmckern_map_in *) arg); 1823 break; 1824 1825 case PMC_FN_MUNMAP: 1826 sx_assert(&pmc_sx, SX_LOCKED); 1827 pmc_process_munmap(td, (struct pmckern_map_out *) arg); 1828 break; 1829 1830 case PMC_FN_USER_CALLCHAIN: 1831 /* 1832 * Record a call chain. 1833 */ 1834 pmc_capture_user_callchain(PCPU_GET(cpuid), 1835 (struct trapframe *) arg); 1836 break; 1837 1838 default: 1839 #ifdef DEBUG 1840 KASSERT(0, ("[pmc,%d] unknown hook %d\n", __LINE__, function)); 1841 #endif 1842 break; 1843 1844 } 1845 1846 return 0; 1847 } 1848 1849 /* 1850 * allocate a 'struct pmc_owner' descriptor in the owner hash table. 1851 */ 1852 1853 static struct pmc_owner * 1854 pmc_allocate_owner_descriptor(struct proc *p) 1855 { 1856 uint32_t hindex; 1857 struct pmc_owner *po; 1858 struct pmc_ownerhash *poh; 1859 1860 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 1861 poh = &pmc_ownerhash[hindex]; 1862 1863 /* allocate space for N pointers and one descriptor struct */ 1864 MALLOC(po, struct pmc_owner *, sizeof(struct pmc_owner), 1865 M_PMC, M_ZERO|M_WAITOK); 1866 1867 po->po_sscount = po->po_error = po->po_flags = 0; 1868 po->po_file = NULL; 1869 po->po_owner = p; 1870 po->po_kthread = NULL; 1871 LIST_INIT(&po->po_pmcs); 1872 LIST_INSERT_HEAD(poh, po, po_next); /* insert into hash table */ 1873 1874 TAILQ_INIT(&po->po_logbuffers); 1875 mtx_init(&po->po_mtx, "pmc-owner-mtx", "pmc-per-proc", MTX_SPIN); 1876 1877 PMCDBG(OWN,ALL,1, "allocate-owner proc=%p (%d, %s) pmc-owner=%p", 1878 p, p->p_pid, p->p_comm, po); 1879 1880 return po; 1881 } 1882 1883 static void 1884 pmc_destroy_owner_descriptor(struct pmc_owner *po) 1885 { 1886 1887 PMCDBG(OWN,REL,1, "destroy-owner po=%p proc=%p (%d, %s)", 1888 po, po->po_owner, po->po_owner->p_pid, po->po_owner->p_comm); 1889 1890 mtx_destroy(&po->po_mtx); 1891 FREE(po, M_PMC); 1892 } 1893 1894 /* 1895 * find the descriptor corresponding to process 'p', adding or removing it 1896 * as specified by 'mode'. 1897 */ 1898 1899 static struct pmc_process * 1900 pmc_find_process_descriptor(struct proc *p, uint32_t mode) 1901 { 1902 uint32_t hindex; 1903 struct pmc_process *pp, *ppnew; 1904 struct pmc_processhash *pph; 1905 1906 hindex = PMC_HASH_PTR(p, pmc_processhashmask); 1907 pph = &pmc_processhash[hindex]; 1908 1909 ppnew = NULL; 1910 1911 /* 1912 * Pre-allocate memory in the FIND_ALLOCATE case since we 1913 * cannot call malloc(9) once we hold a spin lock. 1914 */ 1915 1916 if (mode & PMC_FLAG_ALLOCATE) { 1917 /* allocate additional space for 'n' pmc pointers */ 1918 MALLOC(ppnew, struct pmc_process *, 1919 sizeof(struct pmc_process) + md->pmd_npmc * 1920 sizeof(struct pmc_targetstate), M_PMC, M_ZERO|M_WAITOK); 1921 } 1922 1923 mtx_lock_spin(&pmc_processhash_mtx); 1924 LIST_FOREACH(pp, pph, pp_next) 1925 if (pp->pp_proc == p) 1926 break; 1927 1928 if ((mode & PMC_FLAG_REMOVE) && pp != NULL) 1929 LIST_REMOVE(pp, pp_next); 1930 1931 if ((mode & PMC_FLAG_ALLOCATE) && pp == NULL && 1932 ppnew != NULL) { 1933 ppnew->pp_proc = p; 1934 LIST_INSERT_HEAD(pph, ppnew, pp_next); 1935 pp = ppnew; 1936 ppnew = NULL; 1937 } 1938 mtx_unlock_spin(&pmc_processhash_mtx); 1939 1940 if (pp != NULL && ppnew != NULL) 1941 FREE(ppnew, M_PMC); 1942 1943 return pp; 1944 } 1945 1946 /* 1947 * remove a process descriptor from the process hash table. 1948 */ 1949 1950 static void 1951 pmc_remove_process_descriptor(struct pmc_process *pp) 1952 { 1953 KASSERT(pp->pp_refcnt == 0, 1954 ("[pmc,%d] Removing process descriptor %p with count %d", 1955 __LINE__, pp, pp->pp_refcnt)); 1956 1957 mtx_lock_spin(&pmc_processhash_mtx); 1958 LIST_REMOVE(pp, pp_next); 1959 mtx_unlock_spin(&pmc_processhash_mtx); 1960 } 1961 1962 1963 /* 1964 * find an owner descriptor corresponding to proc 'p' 1965 */ 1966 1967 static struct pmc_owner * 1968 pmc_find_owner_descriptor(struct proc *p) 1969 { 1970 uint32_t hindex; 1971 struct pmc_owner *po; 1972 struct pmc_ownerhash *poh; 1973 1974 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 1975 poh = &pmc_ownerhash[hindex]; 1976 1977 po = NULL; 1978 LIST_FOREACH(po, poh, po_next) 1979 if (po->po_owner == p) 1980 break; 1981 1982 PMCDBG(OWN,FND,1, "find-owner proc=%p (%d, %s) hindex=0x%x -> " 1983 "pmc-owner=%p", p, p->p_pid, p->p_comm, hindex, po); 1984 1985 return po; 1986 } 1987 1988 /* 1989 * pmc_allocate_pmc_descriptor 1990 * 1991 * Allocate a pmc descriptor and initialize its 1992 * fields. 1993 */ 1994 1995 static struct pmc * 1996 pmc_allocate_pmc_descriptor(void) 1997 { 1998 struct pmc *pmc; 1999 2000 MALLOC(pmc, struct pmc *, sizeof(struct pmc), M_PMC, M_ZERO|M_WAITOK); 2001 2002 if (pmc != NULL) { 2003 pmc->pm_owner = NULL; 2004 LIST_INIT(&pmc->pm_targets); 2005 } 2006 2007 PMCDBG(PMC,ALL,1, "allocate-pmc -> pmc=%p", pmc); 2008 2009 return pmc; 2010 } 2011 2012 /* 2013 * Destroy a pmc descriptor. 2014 */ 2015 2016 static void 2017 pmc_destroy_pmc_descriptor(struct pmc *pm) 2018 { 2019 (void) pm; 2020 2021 #ifdef DEBUG 2022 KASSERT(pm->pm_state == PMC_STATE_DELETED || 2023 pm->pm_state == PMC_STATE_FREE, 2024 ("[pmc,%d] destroying non-deleted PMC", __LINE__)); 2025 KASSERT(LIST_EMPTY(&pm->pm_targets), 2026 ("[pmc,%d] destroying pmc with targets", __LINE__)); 2027 KASSERT(pm->pm_owner == NULL, 2028 ("[pmc,%d] destroying pmc attached to an owner", __LINE__)); 2029 KASSERT(pm->pm_runcount == 0, 2030 ("[pmc,%d] pmc has non-zero run count %d", __LINE__, 2031 pm->pm_runcount)); 2032 #endif 2033 } 2034 2035 static void 2036 pmc_wait_for_pmc_idle(struct pmc *pm) 2037 { 2038 #ifdef DEBUG 2039 volatile int maxloop; 2040 2041 maxloop = 100 * mp_ncpus; 2042 #endif 2043 2044 /* 2045 * Loop (with a forced context switch) till the PMC's runcount 2046 * comes down to zero. 2047 */ 2048 while (atomic_load_acq_32(&pm->pm_runcount) > 0) { 2049 #ifdef DEBUG 2050 maxloop--; 2051 KASSERT(maxloop > 0, 2052 ("[pmc,%d] (ri%d, rc%d) waiting too long for " 2053 "pmc to be free", __LINE__, 2054 PMC_TO_ROWINDEX(pm), pm->pm_runcount)); 2055 #endif 2056 pmc_force_context_switch(); 2057 } 2058 } 2059 2060 /* 2061 * This function does the following things: 2062 * 2063 * - detaches the PMC from hardware 2064 * - unlinks all target threads that were attached to it 2065 * - removes the PMC from its owner's list 2066 * - destroy's the PMC private mutex 2067 * 2068 * Once this function completes, the given pmc pointer can be safely 2069 * FREE'd by the caller. 2070 */ 2071 2072 static void 2073 pmc_release_pmc_descriptor(struct pmc *pm) 2074 { 2075 u_int ri, cpu; 2076 enum pmc_mode mode; 2077 struct pmc_hw *phw; 2078 struct pmc_owner *po; 2079 struct pmc_process *pp; 2080 struct pmc_target *ptgt, *tmp; 2081 struct pmc_binding pb; 2082 2083 sx_assert(&pmc_sx, SX_XLOCKED); 2084 2085 KASSERT(pm, ("[pmc,%d] null pmc", __LINE__)); 2086 2087 ri = PMC_TO_ROWINDEX(pm); 2088 mode = PMC_TO_MODE(pm); 2089 2090 PMCDBG(PMC,REL,1, "release-pmc pmc=%p ri=%d mode=%d", pm, ri, 2091 mode); 2092 2093 /* 2094 * First, we take the PMC off hardware. 2095 */ 2096 cpu = 0; 2097 if (PMC_IS_SYSTEM_MODE(mode)) { 2098 2099 /* 2100 * A system mode PMC runs on a specific CPU. Switch 2101 * to this CPU and turn hardware off. 2102 */ 2103 pmc_save_cpu_binding(&pb); 2104 2105 cpu = PMC_TO_CPU(pm); 2106 2107 pmc_select_cpu(cpu); 2108 2109 /* switch off non-stalled CPUs */ 2110 if (pm->pm_state == PMC_STATE_RUNNING && 2111 pm->pm_stalled == 0) { 2112 2113 phw = pmc_pcpu[cpu]->pc_hwpmcs[ri]; 2114 2115 KASSERT(phw->phw_pmc == pm, 2116 ("[pmc, %d] pmc ptr ri(%d) hw(%p) pm(%p)", 2117 __LINE__, ri, phw->phw_pmc, pm)); 2118 PMCDBG(PMC,REL,2, "stopping cpu=%d ri=%d", cpu, ri); 2119 2120 critical_enter(); 2121 md->pmd_stop_pmc(cpu, ri); 2122 critical_exit(); 2123 } 2124 2125 PMCDBG(PMC,REL,2, "decfg cpu=%d ri=%d", cpu, ri); 2126 2127 critical_enter(); 2128 md->pmd_config_pmc(cpu, ri, NULL); 2129 critical_exit(); 2130 2131 /* adjust the global and process count of SS mode PMCs */ 2132 if (mode == PMC_MODE_SS && pm->pm_state == PMC_STATE_RUNNING) { 2133 po = pm->pm_owner; 2134 po->po_sscount--; 2135 if (po->po_sscount == 0) { 2136 atomic_subtract_rel_int(&pmc_ss_count, 1); 2137 LIST_REMOVE(po, po_ssnext); 2138 } 2139 } 2140 2141 pm->pm_state = PMC_STATE_DELETED; 2142 2143 pmc_restore_cpu_binding(&pb); 2144 2145 /* 2146 * We could have references to this PMC structure in 2147 * the per-cpu sample queues. Wait for the queue to 2148 * drain. 2149 */ 2150 pmc_wait_for_pmc_idle(pm); 2151 2152 } else if (PMC_IS_VIRTUAL_MODE(mode)) { 2153 2154 /* 2155 * A virtual PMC could be running on multiple CPUs at 2156 * a given instant. 2157 * 2158 * By marking its state as DELETED, we ensure that 2159 * this PMC is never further scheduled on hardware. 2160 * 2161 * Then we wait till all CPUs are done with this PMC. 2162 */ 2163 pm->pm_state = PMC_STATE_DELETED; 2164 2165 2166 /* Wait for the PMCs runcount to come to zero. */ 2167 pmc_wait_for_pmc_idle(pm); 2168 2169 /* 2170 * At this point the PMC is off all CPUs and cannot be 2171 * freshly scheduled onto a CPU. It is now safe to 2172 * unlink all targets from this PMC. If a 2173 * process-record's refcount falls to zero, we remove 2174 * it from the hash table. The module-wide SX lock 2175 * protects us from races. 2176 */ 2177 LIST_FOREACH_SAFE(ptgt, &pm->pm_targets, pt_next, tmp) { 2178 pp = ptgt->pt_process; 2179 pmc_unlink_target_process(pm, pp); /* frees 'ptgt' */ 2180 2181 PMCDBG(PMC,REL,3, "pp->refcnt=%d", pp->pp_refcnt); 2182 2183 /* 2184 * If the target process record shows that no 2185 * PMCs are attached to it, reclaim its space. 2186 */ 2187 2188 if (pp->pp_refcnt == 0) { 2189 pmc_remove_process_descriptor(pp); 2190 FREE(pp, M_PMC); 2191 } 2192 } 2193 2194 cpu = curthread->td_oncpu; /* setup cpu for pmd_release() */ 2195 2196 } 2197 2198 /* 2199 * Release any MD resources 2200 */ 2201 2202 (void) md->pmd_release_pmc(cpu, ri, pm); 2203 2204 /* 2205 * Update row disposition 2206 */ 2207 2208 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) 2209 PMC_UNMARK_ROW_STANDALONE(ri); 2210 else 2211 PMC_UNMARK_ROW_THREAD(ri); 2212 2213 /* unlink from the owner's list */ 2214 if (pm->pm_owner) { 2215 LIST_REMOVE(pm, pm_next); 2216 pm->pm_owner = NULL; 2217 } 2218 2219 pmc_destroy_pmc_descriptor(pm); 2220 } 2221 2222 /* 2223 * Register an owner and a pmc. 2224 */ 2225 2226 static int 2227 pmc_register_owner(struct proc *p, struct pmc *pmc) 2228 { 2229 struct pmc_owner *po; 2230 2231 sx_assert(&pmc_sx, SX_XLOCKED); 2232 2233 if ((po = pmc_find_owner_descriptor(p)) == NULL) 2234 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) 2235 return ENOMEM; 2236 2237 KASSERT(pmc->pm_owner == NULL, 2238 ("[pmc,%d] attempting to own an initialized PMC", __LINE__)); 2239 pmc->pm_owner = po; 2240 2241 LIST_INSERT_HEAD(&po->po_pmcs, pmc, pm_next); 2242 2243 PROC_LOCK(p); 2244 p->p_flag |= P_HWPMC; 2245 PROC_UNLOCK(p); 2246 2247 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 2248 pmclog_process_pmcallocate(pmc); 2249 2250 PMCDBG(PMC,REG,1, "register-owner pmc-owner=%p pmc=%p", 2251 po, pmc); 2252 2253 return 0; 2254 } 2255 2256 /* 2257 * Return the current row disposition: 2258 * == 0 => FREE 2259 * > 0 => PROCESS MODE 2260 * < 0 => SYSTEM MODE 2261 */ 2262 2263 int 2264 pmc_getrowdisp(int ri) 2265 { 2266 return pmc_pmcdisp[ri]; 2267 } 2268 2269 /* 2270 * Check if a PMC at row index 'ri' can be allocated to the current 2271 * process. 2272 * 2273 * Allocation can fail if: 2274 * - the current process is already being profiled by a PMC at index 'ri', 2275 * attached to it via OP_PMCATTACH. 2276 * - the current process has already allocated a PMC at index 'ri' 2277 * via OP_ALLOCATE. 2278 */ 2279 2280 static int 2281 pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, int cpu) 2282 { 2283 enum pmc_mode mode; 2284 struct pmc *pm; 2285 struct pmc_owner *po; 2286 struct pmc_process *pp; 2287 2288 PMCDBG(PMC,ALR,1, "can-allocate-rowindex proc=%p (%d, %s) ri=%d " 2289 "cpu=%d", p, p->p_pid, p->p_comm, ri, cpu); 2290 2291 /* 2292 * We shouldn't have already allocated a process-mode PMC at 2293 * row index 'ri'. 2294 * 2295 * We shouldn't have allocated a system-wide PMC on the same 2296 * CPU and same RI. 2297 */ 2298 if ((po = pmc_find_owner_descriptor(p)) != NULL) 2299 LIST_FOREACH(pm, &po->po_pmcs, pm_next) { 2300 if (PMC_TO_ROWINDEX(pm) == ri) { 2301 mode = PMC_TO_MODE(pm); 2302 if (PMC_IS_VIRTUAL_MODE(mode)) 2303 return EEXIST; 2304 if (PMC_IS_SYSTEM_MODE(mode) && 2305 (int) PMC_TO_CPU(pm) == cpu) 2306 return EEXIST; 2307 } 2308 } 2309 2310 /* 2311 * We also shouldn't be the target of any PMC at this index 2312 * since otherwise a PMC_ATTACH to ourselves will fail. 2313 */ 2314 if ((pp = pmc_find_process_descriptor(p, 0)) != NULL) 2315 if (pp->pp_pmcs[ri].pp_pmc) 2316 return EEXIST; 2317 2318 PMCDBG(PMC,ALR,2, "can-allocate-rowindex proc=%p (%d, %s) ri=%d ok", 2319 p, p->p_pid, p->p_comm, ri); 2320 2321 return 0; 2322 } 2323 2324 /* 2325 * Check if a given PMC at row index 'ri' can be currently used in 2326 * mode 'mode'. 2327 */ 2328 2329 static int 2330 pmc_can_allocate_row(int ri, enum pmc_mode mode) 2331 { 2332 enum pmc_disp disp; 2333 2334 sx_assert(&pmc_sx, SX_XLOCKED); 2335 2336 PMCDBG(PMC,ALR,1, "can-allocate-row ri=%d mode=%d", ri, mode); 2337 2338 if (PMC_IS_SYSTEM_MODE(mode)) 2339 disp = PMC_DISP_STANDALONE; 2340 else 2341 disp = PMC_DISP_THREAD; 2342 2343 /* 2344 * check disposition for PMC row 'ri': 2345 * 2346 * Expected disposition Row-disposition Result 2347 * 2348 * STANDALONE STANDALONE or FREE proceed 2349 * STANDALONE THREAD fail 2350 * THREAD THREAD or FREE proceed 2351 * THREAD STANDALONE fail 2352 */ 2353 2354 if (!PMC_ROW_DISP_IS_FREE(ri) && 2355 !(disp == PMC_DISP_THREAD && PMC_ROW_DISP_IS_THREAD(ri)) && 2356 !(disp == PMC_DISP_STANDALONE && PMC_ROW_DISP_IS_STANDALONE(ri))) 2357 return EBUSY; 2358 2359 /* 2360 * All OK 2361 */ 2362 2363 PMCDBG(PMC,ALR,2, "can-allocate-row ri=%d mode=%d ok", ri, mode); 2364 2365 return 0; 2366 2367 } 2368 2369 /* 2370 * Find a PMC descriptor with user handle 'pmcid' for thread 'td'. 2371 */ 2372 2373 static struct pmc * 2374 pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, pmc_id_t pmcid) 2375 { 2376 struct pmc *pm; 2377 2378 KASSERT(PMC_ID_TO_ROWINDEX(pmcid) < md->pmd_npmc, 2379 ("[pmc,%d] Illegal pmc index %d (max %d)", __LINE__, 2380 PMC_ID_TO_ROWINDEX(pmcid), md->pmd_npmc)); 2381 2382 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 2383 if (pm->pm_id == pmcid) 2384 return pm; 2385 2386 return NULL; 2387 } 2388 2389 static int 2390 pmc_find_pmc(pmc_id_t pmcid, struct pmc **pmc) 2391 { 2392 2393 struct pmc *pm; 2394 struct pmc_owner *po; 2395 2396 PMCDBG(PMC,FND,1, "find-pmc id=%d", pmcid); 2397 2398 if ((po = pmc_find_owner_descriptor(curthread->td_proc)) == NULL) 2399 return ESRCH; 2400 2401 if ((pm = pmc_find_pmc_descriptor_in_process(po, pmcid)) == NULL) 2402 return EINVAL; 2403 2404 PMCDBG(PMC,FND,2, "find-pmc id=%d -> pmc=%p", pmcid, pm); 2405 2406 *pmc = pm; 2407 return 0; 2408 } 2409 2410 /* 2411 * Start a PMC. 2412 */ 2413 2414 static int 2415 pmc_start(struct pmc *pm) 2416 { 2417 int error, cpu, ri; 2418 enum pmc_mode mode; 2419 struct pmc_owner *po; 2420 struct pmc_binding pb; 2421 2422 KASSERT(pm != NULL, 2423 ("[pmc,%d] null pm", __LINE__)); 2424 2425 mode = PMC_TO_MODE(pm); 2426 ri = PMC_TO_ROWINDEX(pm); 2427 error = 0; 2428 2429 PMCDBG(PMC,OPS,1, "start pmc=%p mode=%d ri=%d", pm, mode, ri); 2430 2431 po = pm->pm_owner; 2432 2433 /* 2434 * Disallow PMCSTART if a logfile is required but has not been 2435 * configured yet. 2436 */ 2437 if ((pm->pm_flags & PMC_F_NEEDS_LOGFILE) && 2438 (po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) 2439 return EDOOFUS; /* programming error */ 2440 2441 /* 2442 * If this is a sampling mode PMC, log mapping information for 2443 * the kernel modules that are currently loaded. 2444 */ 2445 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 2446 pmc_log_kernel_mappings(pm); 2447 2448 if (PMC_IS_VIRTUAL_MODE(mode)) { 2449 2450 /* 2451 * If a PMCATTACH has never been done on this PMC, 2452 * attach it to its owner process. 2453 */ 2454 2455 if (LIST_EMPTY(&pm->pm_targets)) 2456 error = (pm->pm_flags & PMC_F_ATTACH_DONE) ? ESRCH : 2457 pmc_attach_process(po->po_owner, pm); 2458 2459 /* 2460 * If the PMC is attached to its owner, then force a context 2461 * switch to ensure that the MD state gets set correctly. 2462 */ 2463 2464 if (error == 0) { 2465 pm->pm_state = PMC_STATE_RUNNING; 2466 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) 2467 pmc_force_context_switch(); 2468 } 2469 2470 return error; 2471 } 2472 2473 2474 /* 2475 * A system-wide PMC. 2476 * 2477 * Add the owner to the global list if this is a system-wide 2478 * sampling PMC. 2479 */ 2480 2481 if (mode == PMC_MODE_SS) { 2482 if (po->po_sscount == 0) { 2483 LIST_INSERT_HEAD(&pmc_ss_owners, po, po_ssnext); 2484 atomic_add_rel_int(&pmc_ss_count, 1); 2485 PMCDBG(PMC,OPS,1, "po=%p in global list", po); 2486 } 2487 po->po_sscount++; 2488 } 2489 2490 /* Log mapping information for all processes in the system. */ 2491 pmc_log_all_process_mappings(po); 2492 2493 /* 2494 * Move to the CPU associated with this 2495 * PMC, and start the hardware. 2496 */ 2497 2498 pmc_save_cpu_binding(&pb); 2499 2500 cpu = PMC_TO_CPU(pm); 2501 2502 if (pmc_cpu_is_disabled(cpu)) 2503 return ENXIO; 2504 2505 pmc_select_cpu(cpu); 2506 2507 /* 2508 * global PMCs are configured at allocation time 2509 * so write out the initial value and start the PMC. 2510 */ 2511 2512 pm->pm_state = PMC_STATE_RUNNING; 2513 2514 critical_enter(); 2515 if ((error = md->pmd_write_pmc(cpu, ri, 2516 PMC_IS_SAMPLING_MODE(mode) ? 2517 pm->pm_sc.pm_reloadcount : 2518 pm->pm_sc.pm_initial)) == 0) 2519 error = md->pmd_start_pmc(cpu, ri); 2520 critical_exit(); 2521 2522 pmc_restore_cpu_binding(&pb); 2523 2524 return error; 2525 } 2526 2527 /* 2528 * Stop a PMC. 2529 */ 2530 2531 static int 2532 pmc_stop(struct pmc *pm) 2533 { 2534 int cpu, error, ri; 2535 struct pmc_owner *po; 2536 struct pmc_binding pb; 2537 2538 KASSERT(pm != NULL, ("[pmc,%d] null pmc", __LINE__)); 2539 2540 PMCDBG(PMC,OPS,1, "stop pmc=%p mode=%d ri=%d", pm, 2541 PMC_TO_MODE(pm), PMC_TO_ROWINDEX(pm)); 2542 2543 pm->pm_state = PMC_STATE_STOPPED; 2544 2545 /* 2546 * If the PMC is a virtual mode one, changing the state to 2547 * non-RUNNING is enough to ensure that the PMC never gets 2548 * scheduled. 2549 * 2550 * If this PMC is current running on a CPU, then it will 2551 * handled correctly at the time its target process is context 2552 * switched out. 2553 */ 2554 2555 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 2556 return 0; 2557 2558 /* 2559 * A system-mode PMC. Move to the CPU associated with 2560 * this PMC, and stop the hardware. We update the 2561 * 'initial count' so that a subsequent PMCSTART will 2562 * resume counting from the current hardware count. 2563 */ 2564 2565 pmc_save_cpu_binding(&pb); 2566 2567 cpu = PMC_TO_CPU(pm); 2568 2569 KASSERT(cpu >= 0 && cpu < mp_ncpus, 2570 ("[pmc,%d] illegal cpu=%d", __LINE__, cpu)); 2571 2572 if (pmc_cpu_is_disabled(cpu)) 2573 return ENXIO; 2574 2575 pmc_select_cpu(cpu); 2576 2577 ri = PMC_TO_ROWINDEX(pm); 2578 2579 critical_enter(); 2580 if ((error = md->pmd_stop_pmc(cpu, ri)) == 0) 2581 error = md->pmd_read_pmc(cpu, ri, &pm->pm_sc.pm_initial); 2582 critical_exit(); 2583 2584 pmc_restore_cpu_binding(&pb); 2585 2586 po = pm->pm_owner; 2587 2588 /* remove this owner from the global list of SS PMC owners */ 2589 if (PMC_TO_MODE(pm) == PMC_MODE_SS) { 2590 po->po_sscount--; 2591 if (po->po_sscount == 0) { 2592 atomic_subtract_rel_int(&pmc_ss_count, 1); 2593 LIST_REMOVE(po, po_ssnext); 2594 PMCDBG(PMC,OPS,2,"po=%p removed from global list", po); 2595 } 2596 } 2597 2598 return error; 2599 } 2600 2601 2602 #ifdef DEBUG 2603 static const char *pmc_op_to_name[] = { 2604 #undef __PMC_OP 2605 #define __PMC_OP(N, D) #N , 2606 __PMC_OPS() 2607 NULL 2608 }; 2609 #endif 2610 2611 /* 2612 * The syscall interface 2613 */ 2614 2615 #define PMC_GET_SX_XLOCK(...) do { \ 2616 sx_xlock(&pmc_sx); \ 2617 if (pmc_hook == NULL) { \ 2618 sx_xunlock(&pmc_sx); \ 2619 return __VA_ARGS__; \ 2620 } \ 2621 } while (0) 2622 2623 #define PMC_DOWNGRADE_SX() do { \ 2624 sx_downgrade(&pmc_sx); \ 2625 is_sx_downgraded = 1; \ 2626 } while (0) 2627 2628 static int 2629 pmc_syscall_handler(struct thread *td, void *syscall_args) 2630 { 2631 int error, is_sx_downgraded, op; 2632 struct pmc_syscall_args *c; 2633 void *arg; 2634 2635 PMC_GET_SX_XLOCK(ENOSYS); 2636 2637 DROP_GIANT(); 2638 2639 is_sx_downgraded = 0; 2640 2641 c = (struct pmc_syscall_args *) syscall_args; 2642 2643 op = c->pmop_code; 2644 arg = c->pmop_data; 2645 2646 PMCDBG(MOD,PMS,1, "syscall op=%d \"%s\" arg=%p", op, 2647 pmc_op_to_name[op], arg); 2648 2649 error = 0; 2650 atomic_add_int(&pmc_stats.pm_syscalls, 1); 2651 2652 switch(op) 2653 { 2654 2655 2656 /* 2657 * Configure a log file. 2658 * 2659 * XXX This OP will be reworked. 2660 */ 2661 2662 case PMC_OP_CONFIGURELOG: 2663 { 2664 struct proc *p; 2665 struct pmc *pm; 2666 struct pmc_owner *po; 2667 struct pmc_op_configurelog cl; 2668 2669 sx_assert(&pmc_sx, SX_XLOCKED); 2670 2671 if ((error = copyin(arg, &cl, sizeof(cl))) != 0) 2672 break; 2673 2674 /* mark this process as owning a log file */ 2675 p = td->td_proc; 2676 if ((po = pmc_find_owner_descriptor(p)) == NULL) 2677 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) { 2678 error = ENOMEM; 2679 break; 2680 } 2681 2682 /* 2683 * If a valid fd was passed in, try to configure that, 2684 * otherwise if 'fd' was less than zero and there was 2685 * a log file configured, flush its buffers and 2686 * de-configure it. 2687 */ 2688 if (cl.pm_logfd >= 0) 2689 error = pmclog_configure_log(po, cl.pm_logfd); 2690 else if (po->po_flags & PMC_PO_OWNS_LOGFILE) { 2691 pmclog_process_closelog(po); 2692 error = pmclog_flush(po); 2693 if (error == 0) { 2694 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 2695 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 2696 pm->pm_state == PMC_STATE_RUNNING) 2697 pmc_stop(pm); 2698 error = pmclog_deconfigure_log(po); 2699 } 2700 } else 2701 error = EINVAL; 2702 2703 if (error) 2704 break; 2705 } 2706 break; 2707 2708 2709 /* 2710 * Flush a log file. 2711 */ 2712 2713 case PMC_OP_FLUSHLOG: 2714 { 2715 struct pmc_owner *po; 2716 2717 sx_assert(&pmc_sx, SX_XLOCKED); 2718 2719 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 2720 error = EINVAL; 2721 break; 2722 } 2723 2724 error = pmclog_flush(po); 2725 } 2726 break; 2727 2728 /* 2729 * Retrieve hardware configuration. 2730 */ 2731 2732 case PMC_OP_GETCPUINFO: /* CPU information */ 2733 { 2734 struct pmc_op_getcpuinfo gci; 2735 2736 gci.pm_cputype = md->pmd_cputype; 2737 gci.pm_ncpu = mp_ncpus; 2738 gci.pm_npmc = md->pmd_npmc; 2739 gci.pm_nclass = md->pmd_nclass; 2740 bcopy(md->pmd_classes, &gci.pm_classes, 2741 sizeof(gci.pm_classes)); 2742 error = copyout(&gci, arg, sizeof(gci)); 2743 } 2744 break; 2745 2746 2747 /* 2748 * Get module statistics 2749 */ 2750 2751 case PMC_OP_GETDRIVERSTATS: 2752 { 2753 struct pmc_op_getdriverstats gms; 2754 2755 bcopy(&pmc_stats, &gms, sizeof(gms)); 2756 error = copyout(&gms, arg, sizeof(gms)); 2757 } 2758 break; 2759 2760 2761 /* 2762 * Retrieve module version number 2763 */ 2764 2765 case PMC_OP_GETMODULEVERSION: 2766 { 2767 uint32_t cv, modv; 2768 2769 /* retrieve the client's idea of the ABI version */ 2770 if ((error = copyin(arg, &cv, sizeof(uint32_t))) != 0) 2771 break; 2772 /* don't service clients newer than our driver */ 2773 modv = PMC_VERSION; 2774 if ((cv & 0xFFFF0000) > (modv & 0xFFFF0000)) { 2775 error = EPROGMISMATCH; 2776 break; 2777 } 2778 error = copyout(&modv, arg, sizeof(int)); 2779 } 2780 break; 2781 2782 2783 /* 2784 * Retrieve the state of all the PMCs on a given 2785 * CPU. 2786 */ 2787 2788 case PMC_OP_GETPMCINFO: 2789 { 2790 uint32_t cpu, n, npmc; 2791 size_t pmcinfo_size; 2792 struct pmc *pm; 2793 struct pmc_info *p, *pmcinfo; 2794 struct pmc_op_getpmcinfo *gpi; 2795 struct pmc_owner *po; 2796 struct pmc_binding pb; 2797 2798 PMC_DOWNGRADE_SX(); 2799 2800 gpi = (struct pmc_op_getpmcinfo *) arg; 2801 2802 if ((error = copyin(&gpi->pm_cpu, &cpu, sizeof(cpu))) != 0) 2803 break; 2804 2805 if (cpu >= (unsigned int) mp_ncpus) { 2806 error = EINVAL; 2807 break; 2808 } 2809 2810 if (pmc_cpu_is_disabled(cpu)) { 2811 error = ENXIO; 2812 break; 2813 } 2814 2815 /* switch to CPU 'cpu' */ 2816 pmc_save_cpu_binding(&pb); 2817 pmc_select_cpu(cpu); 2818 2819 npmc = md->pmd_npmc; 2820 2821 pmcinfo_size = npmc * sizeof(struct pmc_info); 2822 MALLOC(pmcinfo, struct pmc_info *, pmcinfo_size, M_PMC, 2823 M_WAITOK); 2824 2825 p = pmcinfo; 2826 2827 for (n = 0; n < md->pmd_npmc; n++, p++) { 2828 2829 if ((error = md->pmd_describe(cpu, n, p, &pm)) != 0) 2830 break; 2831 2832 if (PMC_ROW_DISP_IS_STANDALONE(n)) 2833 p->pm_rowdisp = PMC_DISP_STANDALONE; 2834 else if (PMC_ROW_DISP_IS_THREAD(n)) 2835 p->pm_rowdisp = PMC_DISP_THREAD; 2836 else 2837 p->pm_rowdisp = PMC_DISP_FREE; 2838 2839 p->pm_ownerpid = -1; 2840 2841 if (pm == NULL) /* no PMC associated */ 2842 continue; 2843 2844 po = pm->pm_owner; 2845 2846 KASSERT(po->po_owner != NULL, 2847 ("[pmc,%d] pmc_owner had a null proc pointer", 2848 __LINE__)); 2849 2850 p->pm_ownerpid = po->po_owner->p_pid; 2851 p->pm_mode = PMC_TO_MODE(pm); 2852 p->pm_event = pm->pm_event; 2853 p->pm_flags = pm->pm_flags; 2854 2855 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 2856 p->pm_reloadcount = 2857 pm->pm_sc.pm_reloadcount; 2858 } 2859 2860 pmc_restore_cpu_binding(&pb); 2861 2862 /* now copy out the PMC info collected */ 2863 if (error == 0) 2864 error = copyout(pmcinfo, &gpi->pm_pmcs, pmcinfo_size); 2865 2866 FREE(pmcinfo, M_PMC); 2867 } 2868 break; 2869 2870 2871 /* 2872 * Set the administrative state of a PMC. I.e. whether 2873 * the PMC is to be used or not. 2874 */ 2875 2876 case PMC_OP_PMCADMIN: 2877 { 2878 int cpu, ri; 2879 enum pmc_state request; 2880 struct pmc_cpu *pc; 2881 struct pmc_hw *phw; 2882 struct pmc_op_pmcadmin pma; 2883 struct pmc_binding pb; 2884 2885 sx_assert(&pmc_sx, SX_XLOCKED); 2886 2887 KASSERT(td == curthread, 2888 ("[pmc,%d] td != curthread", __LINE__)); 2889 2890 error = priv_check(td, PRIV_PMC_MANAGE); 2891 if (error) 2892 break; 2893 2894 if ((error = copyin(arg, &pma, sizeof(pma))) != 0) 2895 break; 2896 2897 cpu = pma.pm_cpu; 2898 2899 if (cpu < 0 || cpu >= mp_ncpus) { 2900 error = EINVAL; 2901 break; 2902 } 2903 2904 if (pmc_cpu_is_disabled(cpu)) { 2905 error = ENXIO; 2906 break; 2907 } 2908 2909 request = pma.pm_state; 2910 2911 if (request != PMC_STATE_DISABLED && 2912 request != PMC_STATE_FREE) { 2913 error = EINVAL; 2914 break; 2915 } 2916 2917 ri = pma.pm_pmc; /* pmc id == row index */ 2918 if (ri < 0 || ri >= (int) md->pmd_npmc) { 2919 error = EINVAL; 2920 break; 2921 } 2922 2923 /* 2924 * We can't disable a PMC with a row-index allocated 2925 * for process virtual PMCs. 2926 */ 2927 2928 if (PMC_ROW_DISP_IS_THREAD(ri) && 2929 request == PMC_STATE_DISABLED) { 2930 error = EBUSY; 2931 break; 2932 } 2933 2934 /* 2935 * otherwise, this PMC on this CPU is either free or 2936 * in system-wide mode. 2937 */ 2938 2939 pmc_save_cpu_binding(&pb); 2940 pmc_select_cpu(cpu); 2941 2942 pc = pmc_pcpu[cpu]; 2943 phw = pc->pc_hwpmcs[ri]; 2944 2945 /* 2946 * XXX do we need some kind of 'forced' disable? 2947 */ 2948 2949 if (phw->phw_pmc == NULL) { 2950 if (request == PMC_STATE_DISABLED && 2951 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED)) { 2952 phw->phw_state &= ~PMC_PHW_FLAG_IS_ENABLED; 2953 PMC_MARK_ROW_STANDALONE(ri); 2954 } else if (request == PMC_STATE_FREE && 2955 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0) { 2956 phw->phw_state |= PMC_PHW_FLAG_IS_ENABLED; 2957 PMC_UNMARK_ROW_STANDALONE(ri); 2958 } 2959 /* other cases are a no-op */ 2960 } else 2961 error = EBUSY; 2962 2963 pmc_restore_cpu_binding(&pb); 2964 } 2965 break; 2966 2967 2968 /* 2969 * Allocate a PMC. 2970 */ 2971 2972 case PMC_OP_PMCALLOCATE: 2973 { 2974 uint32_t caps; 2975 u_int cpu; 2976 int n; 2977 enum pmc_mode mode; 2978 struct pmc *pmc; 2979 struct pmc_hw *phw; 2980 struct pmc_op_pmcallocate pa; 2981 struct pmc_binding pb; 2982 2983 if ((error = copyin(arg, &pa, sizeof(pa))) != 0) 2984 break; 2985 2986 caps = pa.pm_caps; 2987 mode = pa.pm_mode; 2988 cpu = pa.pm_cpu; 2989 2990 if ((mode != PMC_MODE_SS && mode != PMC_MODE_SC && 2991 mode != PMC_MODE_TS && mode != PMC_MODE_TC) || 2992 (cpu != (u_int) PMC_CPU_ANY && cpu >= (u_int) mp_ncpus)) { 2993 error = EINVAL; 2994 break; 2995 } 2996 2997 /* 2998 * Virtual PMCs should only ask for a default CPU. 2999 * System mode PMCs need to specify a non-default CPU. 3000 */ 3001 3002 if ((PMC_IS_VIRTUAL_MODE(mode) && cpu != (u_int) PMC_CPU_ANY) || 3003 (PMC_IS_SYSTEM_MODE(mode) && cpu == (u_int) PMC_CPU_ANY)) { 3004 error = EINVAL; 3005 break; 3006 } 3007 3008 /* 3009 * Check that a disabled CPU is not being asked for. 3010 */ 3011 3012 if (PMC_IS_SYSTEM_MODE(mode) && pmc_cpu_is_disabled(cpu)) { 3013 error = ENXIO; 3014 break; 3015 } 3016 3017 /* 3018 * Refuse an allocation for a system-wide PMC if this 3019 * process has been jailed, or if this process lacks 3020 * super-user credentials and the sysctl tunable 3021 * 'security.bsd.unprivileged_syspmcs' is zero. 3022 */ 3023 3024 if (PMC_IS_SYSTEM_MODE(mode)) { 3025 if (jailed(curthread->td_ucred)) { 3026 error = EPERM; 3027 break; 3028 } 3029 if (!pmc_unprivileged_syspmcs) { 3030 error = priv_check(curthread, 3031 PRIV_PMC_SYSTEM); 3032 if (error) 3033 break; 3034 } 3035 } 3036 3037 if (error) 3038 break; 3039 3040 /* 3041 * Look for valid values for 'pm_flags' 3042 */ 3043 3044 if ((pa.pm_flags & ~(PMC_F_DESCENDANTS | PMC_F_LOG_PROCCSW | 3045 PMC_F_LOG_PROCEXIT | PMC_F_CALLCHAIN)) != 0) { 3046 error = EINVAL; 3047 break; 3048 } 3049 3050 /* process logging options are not allowed for system PMCs */ 3051 if (PMC_IS_SYSTEM_MODE(mode) && (pa.pm_flags & 3052 (PMC_F_LOG_PROCCSW | PMC_F_LOG_PROCEXIT))) { 3053 error = EINVAL; 3054 break; 3055 } 3056 3057 /* 3058 * All sampling mode PMCs need to be able to interrupt the 3059 * CPU. 3060 */ 3061 if (PMC_IS_SAMPLING_MODE(mode)) 3062 caps |= PMC_CAP_INTERRUPT; 3063 3064 /* A valid class specifier should have been passed in. */ 3065 for (n = 0; n < md->pmd_nclass; n++) 3066 if (md->pmd_classes[n].pm_class == pa.pm_class) 3067 break; 3068 if (n == md->pmd_nclass) { 3069 error = EINVAL; 3070 break; 3071 } 3072 3073 /* The requested PMC capabilities should be feasible. */ 3074 if ((md->pmd_classes[n].pm_caps & caps) != caps) { 3075 error = EOPNOTSUPP; 3076 break; 3077 } 3078 3079 PMCDBG(PMC,ALL,2, "event=%d caps=0x%x mode=%d cpu=%d", 3080 pa.pm_ev, caps, mode, cpu); 3081 3082 pmc = pmc_allocate_pmc_descriptor(); 3083 pmc->pm_id = PMC_ID_MAKE_ID(cpu,pa.pm_mode,pa.pm_class, 3084 PMC_ID_INVALID); 3085 pmc->pm_event = pa.pm_ev; 3086 pmc->pm_state = PMC_STATE_FREE; 3087 pmc->pm_caps = caps; 3088 pmc->pm_flags = pa.pm_flags; 3089 3090 /* switch thread to CPU 'cpu' */ 3091 pmc_save_cpu_binding(&pb); 3092 3093 #define PMC_IS_SHAREABLE_PMC(cpu, n) \ 3094 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_state & \ 3095 PMC_PHW_FLAG_IS_SHAREABLE) 3096 #define PMC_IS_UNALLOCATED(cpu, n) \ 3097 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_pmc == NULL) 3098 3099 if (PMC_IS_SYSTEM_MODE(mode)) { 3100 pmc_select_cpu(cpu); 3101 for (n = 0; n < (int) md->pmd_npmc; n++) 3102 if (pmc_can_allocate_row(n, mode) == 0 && 3103 pmc_can_allocate_rowindex( 3104 curthread->td_proc, n, cpu) == 0 && 3105 (PMC_IS_UNALLOCATED(cpu, n) || 3106 PMC_IS_SHAREABLE_PMC(cpu, n)) && 3107 md->pmd_allocate_pmc(cpu, n, pmc, 3108 &pa) == 0) 3109 break; 3110 } else { 3111 /* Process virtual mode */ 3112 for (n = 0; n < (int) md->pmd_npmc; n++) { 3113 if (pmc_can_allocate_row(n, mode) == 0 && 3114 pmc_can_allocate_rowindex( 3115 curthread->td_proc, n, 3116 PMC_CPU_ANY) == 0 && 3117 md->pmd_allocate_pmc(curthread->td_oncpu, 3118 n, pmc, &pa) == 0) 3119 break; 3120 } 3121 } 3122 3123 #undef PMC_IS_UNALLOCATED 3124 #undef PMC_IS_SHAREABLE_PMC 3125 3126 pmc_restore_cpu_binding(&pb); 3127 3128 if (n == (int) md->pmd_npmc) { 3129 pmc_destroy_pmc_descriptor(pmc); 3130 FREE(pmc, M_PMC); 3131 pmc = NULL; 3132 error = EINVAL; 3133 break; 3134 } 3135 3136 /* Fill in the correct value in the ID field */ 3137 pmc->pm_id = PMC_ID_MAKE_ID(cpu,mode,pa.pm_class,n); 3138 3139 PMCDBG(PMC,ALL,2, "ev=%d class=%d mode=%d n=%d -> pmcid=%x", 3140 pmc->pm_event, pa.pm_class, mode, n, pmc->pm_id); 3141 3142 /* Process mode PMCs with logging enabled need log files */ 3143 if (pmc->pm_flags & (PMC_F_LOG_PROCEXIT | PMC_F_LOG_PROCCSW)) 3144 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3145 3146 /* All system mode sampling PMCs require a log file */ 3147 if (PMC_IS_SAMPLING_MODE(mode) && PMC_IS_SYSTEM_MODE(mode)) 3148 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3149 3150 /* 3151 * Configure global pmc's immediately 3152 */ 3153 3154 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pmc))) { 3155 3156 pmc_save_cpu_binding(&pb); 3157 pmc_select_cpu(cpu); 3158 3159 phw = pmc_pcpu[cpu]->pc_hwpmcs[n]; 3160 3161 if ((phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0 || 3162 (error = md->pmd_config_pmc(cpu, n, pmc)) != 0) { 3163 (void) md->pmd_release_pmc(cpu, n, pmc); 3164 pmc_destroy_pmc_descriptor(pmc); 3165 FREE(pmc, M_PMC); 3166 pmc = NULL; 3167 pmc_restore_cpu_binding(&pb); 3168 error = EPERM; 3169 break; 3170 } 3171 3172 pmc_restore_cpu_binding(&pb); 3173 } 3174 3175 pmc->pm_state = PMC_STATE_ALLOCATED; 3176 3177 /* 3178 * mark row disposition 3179 */ 3180 3181 if (PMC_IS_SYSTEM_MODE(mode)) 3182 PMC_MARK_ROW_STANDALONE(n); 3183 else 3184 PMC_MARK_ROW_THREAD(n); 3185 3186 /* 3187 * Register this PMC with the current thread as its owner. 3188 */ 3189 3190 if ((error = 3191 pmc_register_owner(curthread->td_proc, pmc)) != 0) { 3192 pmc_release_pmc_descriptor(pmc); 3193 FREE(pmc, M_PMC); 3194 pmc = NULL; 3195 break; 3196 } 3197 3198 /* 3199 * Return the allocated index. 3200 */ 3201 3202 pa.pm_pmcid = pmc->pm_id; 3203 3204 error = copyout(&pa, arg, sizeof(pa)); 3205 } 3206 break; 3207 3208 3209 /* 3210 * Attach a PMC to a process. 3211 */ 3212 3213 case PMC_OP_PMCATTACH: 3214 { 3215 struct pmc *pm; 3216 struct proc *p; 3217 struct pmc_op_pmcattach a; 3218 3219 sx_assert(&pmc_sx, SX_XLOCKED); 3220 3221 if ((error = copyin(arg, &a, sizeof(a))) != 0) 3222 break; 3223 3224 if (a.pm_pid < 0) { 3225 error = EINVAL; 3226 break; 3227 } else if (a.pm_pid == 0) 3228 a.pm_pid = td->td_proc->p_pid; 3229 3230 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 3231 break; 3232 3233 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) { 3234 error = EINVAL; 3235 break; 3236 } 3237 3238 /* PMCs may be (re)attached only when allocated or stopped */ 3239 if (pm->pm_state == PMC_STATE_RUNNING) { 3240 error = EBUSY; 3241 break; 3242 } else if (pm->pm_state != PMC_STATE_ALLOCATED && 3243 pm->pm_state != PMC_STATE_STOPPED) { 3244 error = EINVAL; 3245 break; 3246 } 3247 3248 /* lookup pid */ 3249 if ((p = pfind(a.pm_pid)) == NULL) { 3250 error = ESRCH; 3251 break; 3252 } 3253 3254 /* 3255 * Ignore processes that are working on exiting. 3256 */ 3257 if (p->p_flag & P_WEXIT) { 3258 error = ESRCH; 3259 PROC_UNLOCK(p); /* pfind() returns a locked process */ 3260 break; 3261 } 3262 3263 /* 3264 * we are allowed to attach a PMC to a process if 3265 * we can debug it. 3266 */ 3267 error = p_candebug(curthread, p); 3268 3269 PROC_UNLOCK(p); 3270 3271 if (error == 0) 3272 error = pmc_attach_process(p, pm); 3273 } 3274 break; 3275 3276 3277 /* 3278 * Detach an attached PMC from a process. 3279 */ 3280 3281 case PMC_OP_PMCDETACH: 3282 { 3283 struct pmc *pm; 3284 struct proc *p; 3285 struct pmc_op_pmcattach a; 3286 3287 if ((error = copyin(arg, &a, sizeof(a))) != 0) 3288 break; 3289 3290 if (a.pm_pid < 0) { 3291 error = EINVAL; 3292 break; 3293 } else if (a.pm_pid == 0) 3294 a.pm_pid = td->td_proc->p_pid; 3295 3296 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 3297 break; 3298 3299 if ((p = pfind(a.pm_pid)) == NULL) { 3300 error = ESRCH; 3301 break; 3302 } 3303 3304 /* 3305 * Treat processes that are in the process of exiting 3306 * as if they were not present. 3307 */ 3308 3309 if (p->p_flag & P_WEXIT) 3310 error = ESRCH; 3311 3312 PROC_UNLOCK(p); /* pfind() returns a locked process */ 3313 3314 if (error == 0) 3315 error = pmc_detach_process(p, pm); 3316 } 3317 break; 3318 3319 3320 /* 3321 * Retrieve the MSR number associated with the counter 3322 * 'pmc_id'. This allows processes to directly use RDPMC 3323 * instructions to read their PMCs, without the overhead of a 3324 * system call. 3325 */ 3326 3327 case PMC_OP_PMCGETMSR: 3328 { 3329 int ri; 3330 struct pmc *pm; 3331 struct pmc_target *pt; 3332 struct pmc_op_getmsr gm; 3333 3334 PMC_DOWNGRADE_SX(); 3335 3336 /* CPU has no 'GETMSR' support */ 3337 if (md->pmd_get_msr == NULL) { 3338 error = ENOSYS; 3339 break; 3340 } 3341 3342 if ((error = copyin(arg, &gm, sizeof(gm))) != 0) 3343 break; 3344 3345 if ((error = pmc_find_pmc(gm.pm_pmcid, &pm)) != 0) 3346 break; 3347 3348 /* 3349 * The allocated PMC has to be a process virtual PMC, 3350 * i.e., of type MODE_T[CS]. Global PMCs can only be 3351 * read using the PMCREAD operation since they may be 3352 * allocated on a different CPU than the one we could 3353 * be running on at the time of the RDPMC instruction. 3354 * 3355 * The GETMSR operation is not allowed for PMCs that 3356 * are inherited across processes. 3357 */ 3358 3359 if (!PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)) || 3360 (pm->pm_flags & PMC_F_DESCENDANTS)) { 3361 error = EINVAL; 3362 break; 3363 } 3364 3365 /* 3366 * It only makes sense to use a RDPMC (or its 3367 * equivalent instruction on non-x86 architectures) on 3368 * a process that has allocated and attached a PMC to 3369 * itself. Conversely the PMC is only allowed to have 3370 * one process attached to it -- its owner. 3371 */ 3372 3373 if ((pt = LIST_FIRST(&pm->pm_targets)) == NULL || 3374 LIST_NEXT(pt, pt_next) != NULL || 3375 pt->pt_process->pp_proc != pm->pm_owner->po_owner) { 3376 error = EINVAL; 3377 break; 3378 } 3379 3380 ri = PMC_TO_ROWINDEX(pm); 3381 3382 if ((error = (*md->pmd_get_msr)(ri, &gm.pm_msr)) < 0) 3383 break; 3384 3385 if ((error = copyout(&gm, arg, sizeof(gm))) < 0) 3386 break; 3387 3388 /* 3389 * Mark our process as using MSRs. Update machine 3390 * state using a forced context switch. 3391 */ 3392 3393 pt->pt_process->pp_flags |= PMC_PP_ENABLE_MSR_ACCESS; 3394 pmc_force_context_switch(); 3395 3396 } 3397 break; 3398 3399 /* 3400 * Release an allocated PMC 3401 */ 3402 3403 case PMC_OP_PMCRELEASE: 3404 { 3405 pmc_id_t pmcid; 3406 struct pmc *pm; 3407 struct pmc_owner *po; 3408 struct pmc_op_simple sp; 3409 3410 /* 3411 * Find PMC pointer for the named PMC. 3412 * 3413 * Use pmc_release_pmc_descriptor() to switch off the 3414 * PMC, remove all its target threads, and remove the 3415 * PMC from its owner's list. 3416 * 3417 * Remove the owner record if this is the last PMC 3418 * owned. 3419 * 3420 * Free up space. 3421 */ 3422 3423 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3424 break; 3425 3426 pmcid = sp.pm_pmcid; 3427 3428 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3429 break; 3430 3431 po = pm->pm_owner; 3432 pmc_release_pmc_descriptor(pm); 3433 pmc_maybe_remove_owner(po); 3434 3435 FREE(pm, M_PMC); 3436 } 3437 break; 3438 3439 3440 /* 3441 * Read and/or write a PMC. 3442 */ 3443 3444 case PMC_OP_PMCRW: 3445 { 3446 uint32_t cpu, ri; 3447 struct pmc *pm; 3448 struct pmc_op_pmcrw *pprw; 3449 struct pmc_op_pmcrw prw; 3450 struct pmc_binding pb; 3451 pmc_value_t oldvalue; 3452 3453 PMC_DOWNGRADE_SX(); 3454 3455 if ((error = copyin(arg, &prw, sizeof(prw))) != 0) 3456 break; 3457 3458 ri = 0; 3459 PMCDBG(PMC,OPS,1, "rw id=%d flags=0x%x", prw.pm_pmcid, 3460 prw.pm_flags); 3461 3462 /* must have at least one flag set */ 3463 if ((prw.pm_flags & (PMC_F_OLDVALUE|PMC_F_NEWVALUE)) == 0) { 3464 error = EINVAL; 3465 break; 3466 } 3467 3468 /* locate pmc descriptor */ 3469 if ((error = pmc_find_pmc(prw.pm_pmcid, &pm)) != 0) 3470 break; 3471 3472 /* Can't read a PMC that hasn't been started. */ 3473 if (pm->pm_state != PMC_STATE_ALLOCATED && 3474 pm->pm_state != PMC_STATE_STOPPED && 3475 pm->pm_state != PMC_STATE_RUNNING) { 3476 error = EINVAL; 3477 break; 3478 } 3479 3480 /* writing a new value is allowed only for 'STOPPED' pmcs */ 3481 if (pm->pm_state == PMC_STATE_RUNNING && 3482 (prw.pm_flags & PMC_F_NEWVALUE)) { 3483 error = EBUSY; 3484 break; 3485 } 3486 3487 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) { 3488 3489 /* 3490 * If this PMC is attached to its owner (i.e., 3491 * the process requesting this operation) and 3492 * is running, then attempt to get an 3493 * upto-date reading from hardware for a READ. 3494 * Writes are only allowed when the PMC is 3495 * stopped, so only update the saved value 3496 * field. 3497 * 3498 * If the PMC is not running, or is not 3499 * attached to its owner, read/write to the 3500 * savedvalue field. 3501 */ 3502 3503 ri = PMC_TO_ROWINDEX(pm); 3504 3505 mtx_pool_lock_spin(pmc_mtxpool, pm); 3506 cpu = curthread->td_oncpu; 3507 3508 if (prw.pm_flags & PMC_F_OLDVALUE) { 3509 if ((pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) && 3510 (pm->pm_state == PMC_STATE_RUNNING)) 3511 error = (*md->pmd_read_pmc)(cpu, ri, 3512 &oldvalue); 3513 else 3514 oldvalue = pm->pm_gv.pm_savedvalue; 3515 } 3516 if (prw.pm_flags & PMC_F_NEWVALUE) 3517 pm->pm_gv.pm_savedvalue = prw.pm_value; 3518 3519 mtx_pool_unlock_spin(pmc_mtxpool, pm); 3520 3521 } else { /* System mode PMCs */ 3522 cpu = PMC_TO_CPU(pm); 3523 ri = PMC_TO_ROWINDEX(pm); 3524 3525 if (pmc_cpu_is_disabled(cpu)) { 3526 error = ENXIO; 3527 break; 3528 } 3529 3530 /* move this thread to CPU 'cpu' */ 3531 pmc_save_cpu_binding(&pb); 3532 pmc_select_cpu(cpu); 3533 3534 critical_enter(); 3535 /* save old value */ 3536 if (prw.pm_flags & PMC_F_OLDVALUE) 3537 if ((error = (*md->pmd_read_pmc)(cpu, ri, 3538 &oldvalue))) 3539 goto error; 3540 /* write out new value */ 3541 if (prw.pm_flags & PMC_F_NEWVALUE) 3542 error = (*md->pmd_write_pmc)(cpu, ri, 3543 prw.pm_value); 3544 error: 3545 critical_exit(); 3546 pmc_restore_cpu_binding(&pb); 3547 if (error) 3548 break; 3549 } 3550 3551 pprw = (struct pmc_op_pmcrw *) arg; 3552 3553 #ifdef DEBUG 3554 if (prw.pm_flags & PMC_F_NEWVALUE) 3555 PMCDBG(PMC,OPS,2, "rw id=%d new %jx -> old %jx", 3556 ri, prw.pm_value, oldvalue); 3557 else if (prw.pm_flags & PMC_F_OLDVALUE) 3558 PMCDBG(PMC,OPS,2, "rw id=%d -> old %jx", ri, oldvalue); 3559 #endif 3560 3561 /* return old value if requested */ 3562 if (prw.pm_flags & PMC_F_OLDVALUE) 3563 if ((error = copyout(&oldvalue, &pprw->pm_value, 3564 sizeof(prw.pm_value)))) 3565 break; 3566 3567 } 3568 break; 3569 3570 3571 /* 3572 * Set the sampling rate for a sampling mode PMC and the 3573 * initial count for a counting mode PMC. 3574 */ 3575 3576 case PMC_OP_PMCSETCOUNT: 3577 { 3578 struct pmc *pm; 3579 struct pmc_op_pmcsetcount sc; 3580 3581 PMC_DOWNGRADE_SX(); 3582 3583 if ((error = copyin(arg, &sc, sizeof(sc))) != 0) 3584 break; 3585 3586 if ((error = pmc_find_pmc(sc.pm_pmcid, &pm)) != 0) 3587 break; 3588 3589 if (pm->pm_state == PMC_STATE_RUNNING) { 3590 error = EBUSY; 3591 break; 3592 } 3593 3594 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 3595 pm->pm_sc.pm_reloadcount = sc.pm_count; 3596 else 3597 pm->pm_sc.pm_initial = sc.pm_count; 3598 } 3599 break; 3600 3601 3602 /* 3603 * Start a PMC. 3604 */ 3605 3606 case PMC_OP_PMCSTART: 3607 { 3608 pmc_id_t pmcid; 3609 struct pmc *pm; 3610 struct pmc_op_simple sp; 3611 3612 sx_assert(&pmc_sx, SX_XLOCKED); 3613 3614 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3615 break; 3616 3617 pmcid = sp.pm_pmcid; 3618 3619 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3620 break; 3621 3622 KASSERT(pmcid == pm->pm_id, 3623 ("[pmc,%d] pmcid %x != id %x", __LINE__, 3624 pm->pm_id, pmcid)); 3625 3626 if (pm->pm_state == PMC_STATE_RUNNING) /* already running */ 3627 break; 3628 else if (pm->pm_state != PMC_STATE_STOPPED && 3629 pm->pm_state != PMC_STATE_ALLOCATED) { 3630 error = EINVAL; 3631 break; 3632 } 3633 3634 error = pmc_start(pm); 3635 } 3636 break; 3637 3638 3639 /* 3640 * Stop a PMC. 3641 */ 3642 3643 case PMC_OP_PMCSTOP: 3644 { 3645 pmc_id_t pmcid; 3646 struct pmc *pm; 3647 struct pmc_op_simple sp; 3648 3649 PMC_DOWNGRADE_SX(); 3650 3651 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3652 break; 3653 3654 pmcid = sp.pm_pmcid; 3655 3656 /* 3657 * Mark the PMC as inactive and invoke the MD stop 3658 * routines if needed. 3659 */ 3660 3661 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3662 break; 3663 3664 KASSERT(pmcid == pm->pm_id, 3665 ("[pmc,%d] pmc id %x != pmcid %x", __LINE__, 3666 pm->pm_id, pmcid)); 3667 3668 if (pm->pm_state == PMC_STATE_STOPPED) /* already stopped */ 3669 break; 3670 else if (pm->pm_state != PMC_STATE_RUNNING) { 3671 error = EINVAL; 3672 break; 3673 } 3674 3675 error = pmc_stop(pm); 3676 } 3677 break; 3678 3679 3680 /* 3681 * Write a user supplied value to the log file. 3682 */ 3683 3684 case PMC_OP_WRITELOG: 3685 { 3686 struct pmc_op_writelog wl; 3687 struct pmc_owner *po; 3688 3689 PMC_DOWNGRADE_SX(); 3690 3691 if ((error = copyin(arg, &wl, sizeof(wl))) != 0) 3692 break; 3693 3694 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 3695 error = EINVAL; 3696 break; 3697 } 3698 3699 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) { 3700 error = EINVAL; 3701 break; 3702 } 3703 3704 error = pmclog_process_userlog(po, &wl); 3705 } 3706 break; 3707 3708 3709 default: 3710 error = EINVAL; 3711 break; 3712 } 3713 3714 if (is_sx_downgraded) 3715 sx_sunlock(&pmc_sx); 3716 else 3717 sx_xunlock(&pmc_sx); 3718 3719 if (error) 3720 atomic_add_int(&pmc_stats.pm_syscall_errors, 1); 3721 3722 PICKUP_GIANT(); 3723 3724 return error; 3725 } 3726 3727 /* 3728 * Helper functions 3729 */ 3730 3731 3732 /* 3733 * Mark the thread as needing callchain capture and post an AST. The 3734 * actual callchain capture will be done in a context where it is safe 3735 * to take page faults. 3736 */ 3737 3738 static void 3739 pmc_post_callchain_ast(void) 3740 { 3741 struct thread *td; 3742 3743 td = curthread; 3744 3745 /* 3746 * Mark this thread as needing processing in ast(). 3747 * td->td_pflags will be safe to touch as the process was in 3748 * user space when it was interrupted. 3749 */ 3750 td->td_pflags |= TDP_CALLCHAIN; 3751 3752 /* 3753 * Again, since we've entered this function directly from 3754 * userland, `td' is guaranteed to be not locked by this CPU, 3755 * so its safe to try acquire the thread lock even though we 3756 * are executing in an NMI context. We need to acquire this 3757 * lock before touching `td_flags' because other CPUs may be 3758 * in the process of touching this field. 3759 */ 3760 thread_lock(td); 3761 td->td_flags |= TDF_ASTPENDING; 3762 thread_unlock(td); 3763 3764 return; 3765 } 3766 3767 /* 3768 * Interrupt processing. 3769 * 3770 * Find a free slot in the per-cpu array of samples and capture the 3771 * current callchain there. If a sample was successfully added, a bit 3772 * is set in mask 'pmc_cpumask' denoting that the DO_SAMPLES hook 3773 * needs to be invoked from the clock handler. 3774 * 3775 * This function is meant to be called from an NMI handler. It cannot 3776 * use any of the locking primitives supplied by the OS. 3777 */ 3778 3779 int 3780 pmc_process_interrupt(int cpu, struct pmc *pm, struct trapframe *tf, 3781 int inuserspace) 3782 { 3783 int error, callchaindepth; 3784 struct thread *td; 3785 struct pmc_sample *ps; 3786 struct pmc_samplebuffer *psb; 3787 3788 error = 0; 3789 3790 /* 3791 * Allocate space for a sample buffer. 3792 */ 3793 psb = pmc_pcpu[cpu]->pc_sb; 3794 3795 ps = psb->ps_write; 3796 if (ps->ps_nsamples) { /* in use, reader hasn't caught up */ 3797 pm->pm_stalled = 1; 3798 atomic_add_int(&pmc_stats.pm_intr_bufferfull, 1); 3799 PMCDBG(SAM,INT,1,"(spc) cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", 3800 cpu, pm, (void *) tf, inuserspace, 3801 (int) (psb->ps_write - psb->ps_samples), 3802 (int) (psb->ps_read - psb->ps_samples)); 3803 error = ENOMEM; 3804 goto done; 3805 } 3806 3807 3808 /* Fill in entry. */ 3809 PMCDBG(SAM,INT,1,"cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", cpu, pm, 3810 (void *) tf, inuserspace, 3811 (int) (psb->ps_write - psb->ps_samples), 3812 (int) (psb->ps_read - psb->ps_samples)); 3813 3814 atomic_add_rel_32(&pm->pm_runcount, 1); /* hold onto PMC */ 3815 ps->ps_pmc = pm; 3816 if ((td = curthread) && td->td_proc) 3817 ps->ps_pid = td->td_proc->p_pid; 3818 else 3819 ps->ps_pid = -1; 3820 ps->ps_cpu = cpu; 3821 ps->ps_flags = inuserspace ? PMC_CC_F_USERSPACE : 0; 3822 3823 callchaindepth = (pm->pm_flags & PMC_F_CALLCHAIN) ? 3824 pmc_callchaindepth : 1; 3825 3826 if (callchaindepth == 1) 3827 ps->ps_pc[0] = PMC_TRAPFRAME_TO_PC(tf); 3828 else { 3829 /* 3830 * Kernel stack traversals can be done immediately, 3831 * while we defer to an AST for user space traversals. 3832 */ 3833 if (!inuserspace) 3834 callchaindepth = 3835 pmc_save_kernel_callchain(ps->ps_pc, 3836 callchaindepth, tf); 3837 else { 3838 pmc_post_callchain_ast(); 3839 callchaindepth = PMC_SAMPLE_INUSE; 3840 } 3841 } 3842 3843 ps->ps_nsamples = callchaindepth; /* mark entry as in use */ 3844 3845 /* increment write pointer, modulo ring buffer size */ 3846 ps++; 3847 if (ps == psb->ps_fence) 3848 psb->ps_write = psb->ps_samples; 3849 else 3850 psb->ps_write = ps; 3851 3852 done: 3853 /* mark CPU as needing processing */ 3854 atomic_set_rel_int(&pmc_cpumask, (1 << cpu)); 3855 3856 return (error); 3857 } 3858 3859 /* 3860 * Capture a user call chain. This function will be called from ast() 3861 * before control returns to userland and before the process gets 3862 * rescheduled. 3863 */ 3864 3865 static void 3866 pmc_capture_user_callchain(int cpu, struct trapframe *tf) 3867 { 3868 int i; 3869 struct pmc *pm; 3870 struct pmc_sample *ps; 3871 struct pmc_samplebuffer *psb; 3872 3873 psb = pmc_pcpu[cpu]->pc_sb; 3874 3875 /* 3876 * Iterate through all deferred callchain requests. 3877 */ 3878 3879 for (i = 0; i < pmc_nsamples; i++) { 3880 3881 ps = &psb->ps_samples[i]; 3882 if (ps->ps_nsamples != PMC_SAMPLE_INUSE) 3883 continue; 3884 3885 pm = ps->ps_pmc; 3886 3887 KASSERT(pm->pm_flags & PMC_F_CALLCHAIN, 3888 ("[pmc,%d] Retrieving callchain for PMC that doesn't " 3889 "want it", __LINE__)); 3890 3891 /* 3892 * Retrieve the callchain and mark the sample buffer 3893 * as 'processable' by the timer tick sweep code. 3894 */ 3895 ps->ps_nsamples = pmc_save_user_callchain(ps->ps_pc, 3896 pmc_callchaindepth, tf); 3897 } 3898 3899 return; 3900 } 3901 3902 3903 /* 3904 * Process saved PC samples. 3905 */ 3906 3907 static void 3908 pmc_process_samples(int cpu) 3909 { 3910 int n, ri; 3911 struct pmc *pm; 3912 struct thread *td; 3913 struct pmc_owner *po; 3914 struct pmc_sample *ps; 3915 struct pmc_samplebuffer *psb; 3916 3917 KASSERT(PCPU_GET(cpuid) == cpu, 3918 ("[pmc,%d] not on the correct CPU pcpu=%d cpu=%d", __LINE__, 3919 PCPU_GET(cpuid), cpu)); 3920 3921 psb = pmc_pcpu[cpu]->pc_sb; 3922 3923 for (n = 0; n < pmc_nsamples; n++) { /* bound on #iterations */ 3924 3925 ps = psb->ps_read; 3926 if (ps->ps_nsamples == PMC_SAMPLE_FREE) 3927 break; 3928 if (ps->ps_nsamples == PMC_SAMPLE_INUSE) { 3929 /* Need a rescan at a later time. */ 3930 atomic_set_rel_int(&pmc_cpumask, (1 << cpu)); 3931 break; 3932 } 3933 3934 pm = ps->ps_pmc; 3935 po = pm->pm_owner; 3936 3937 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 3938 ("[pmc,%d] pmc=%p non-sampling mode=%d", __LINE__, 3939 pm, PMC_TO_MODE(pm))); 3940 3941 /* Ignore PMCs that have been switched off */ 3942 if (pm->pm_state != PMC_STATE_RUNNING) 3943 goto entrydone; 3944 3945 PMCDBG(SAM,OPS,1,"cpu=%d pm=%p n=%d fl=%x wr=%d rd=%d", cpu, 3946 pm, ps->ps_nsamples, ps->ps_flags, 3947 (int) (psb->ps_write - psb->ps_samples), 3948 (int) (psb->ps_read - psb->ps_samples)); 3949 3950 /* 3951 * If this is a process-mode PMC that is attached to 3952 * its owner, and if the PC is in user mode, update 3953 * profiling statistics like timer-based profiling 3954 * would have done. 3955 */ 3956 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) { 3957 if (ps->ps_flags & PMC_CC_F_USERSPACE) { 3958 td = FIRST_THREAD_IN_PROC(po->po_owner); 3959 addupc_intr(td, ps->ps_pc[0], 1); 3960 } 3961 goto entrydone; 3962 } 3963 3964 /* 3965 * Otherwise, this is either a sampling mode PMC that 3966 * is attached to a different process than its owner, 3967 * or a system-wide sampling PMC. Dispatch a log 3968 * entry to the PMC's owner process. 3969 */ 3970 3971 pmclog_process_callchain(pm, ps); 3972 3973 entrydone: 3974 ps->ps_nsamples = 0; /* mark entry as free */ 3975 atomic_subtract_rel_32(&pm->pm_runcount, 1); 3976 3977 /* increment read pointer, modulo sample size */ 3978 if (++ps == psb->ps_fence) 3979 psb->ps_read = psb->ps_samples; 3980 else 3981 psb->ps_read = ps; 3982 } 3983 3984 atomic_add_int(&pmc_stats.pm_log_sweeps, 1); 3985 3986 /* Do not re-enable stalled PMCs if we failed to process any samples */ 3987 if (n == 0) 3988 return; 3989 3990 /* 3991 * Restart any stalled sampling PMCs on this CPU. 3992 * 3993 * If the NMI handler sets the pm_stalled field of a PMC after 3994 * the check below, we'll end up processing the stalled PMC at 3995 * the next hardclock tick. 3996 */ 3997 for (n = 0; n < md->pmd_npmc; n++) { 3998 (void) (*md->pmd_get_config)(cpu,n,&pm); 3999 if (pm == NULL || /* !cfg'ed */ 4000 pm->pm_state != PMC_STATE_RUNNING || /* !active */ 4001 !PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) || /* !sampling */ 4002 pm->pm_stalled == 0) /* !stalled */ 4003 continue; 4004 4005 pm->pm_stalled = 0; 4006 ri = PMC_TO_ROWINDEX(pm); 4007 (*md->pmd_start_pmc)(cpu, ri); 4008 } 4009 } 4010 4011 /* 4012 * Event handlers. 4013 */ 4014 4015 /* 4016 * Handle a process exit. 4017 * 4018 * Remove this process from all hash tables. If this process 4019 * owned any PMCs, turn off those PMCs and deallocate them, 4020 * removing any associations with target processes. 4021 * 4022 * This function will be called by the last 'thread' of a 4023 * process. 4024 * 4025 * XXX This eventhandler gets called early in the exit process. 4026 * Consider using a 'hook' invocation from thread_exit() or equivalent 4027 * spot. Another negative is that kse_exit doesn't seem to call 4028 * exit1() [??]. 4029 * 4030 */ 4031 4032 static void 4033 pmc_process_exit(void *arg __unused, struct proc *p) 4034 { 4035 int is_using_hwpmcs; 4036 int cpu; 4037 unsigned int ri; 4038 struct pmc *pm; 4039 struct pmc_process *pp; 4040 struct pmc_owner *po; 4041 pmc_value_t newvalue, tmp; 4042 4043 PROC_LOCK(p); 4044 is_using_hwpmcs = p->p_flag & P_HWPMC; 4045 PROC_UNLOCK(p); 4046 4047 /* 4048 * Log a sysexit event to all SS PMC owners. 4049 */ 4050 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4051 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4052 pmclog_process_sysexit(po, p->p_pid); 4053 4054 if (!is_using_hwpmcs) 4055 return; 4056 4057 PMC_GET_SX_XLOCK(); 4058 PMCDBG(PRC,EXT,1,"process-exit proc=%p (%d, %s)", p, p->p_pid, 4059 p->p_comm); 4060 4061 /* 4062 * Since this code is invoked by the last thread in an exiting 4063 * process, we would have context switched IN at some prior 4064 * point. However, with PREEMPTION, kernel mode context 4065 * switches may happen any time, so we want to disable a 4066 * context switch OUT till we get any PMCs targetting this 4067 * process off the hardware. 4068 * 4069 * We also need to atomically remove this process' 4070 * entry from our target process hash table, using 4071 * PMC_FLAG_REMOVE. 4072 */ 4073 PMCDBG(PRC,EXT,1, "process-exit proc=%p (%d, %s)", p, p->p_pid, 4074 p->p_comm); 4075 4076 critical_enter(); /* no preemption */ 4077 4078 cpu = curthread->td_oncpu; 4079 4080 if ((pp = pmc_find_process_descriptor(p, 4081 PMC_FLAG_REMOVE)) != NULL) { 4082 4083 PMCDBG(PRC,EXT,2, 4084 "process-exit proc=%p pmc-process=%p", p, pp); 4085 4086 /* 4087 * The exiting process could the target of 4088 * some PMCs which will be running on 4089 * currently executing CPU. 4090 * 4091 * We need to turn these PMCs off like we 4092 * would do at context switch OUT time. 4093 */ 4094 for (ri = 0; ri < md->pmd_npmc; ri++) { 4095 4096 /* 4097 * Pick up the pmc pointer from hardware 4098 * state similar to the CSW_OUT code. 4099 */ 4100 pm = NULL; 4101 (void) (*md->pmd_get_config)(cpu, ri, &pm); 4102 4103 PMCDBG(PRC,EXT,2, "ri=%d pm=%p", ri, pm); 4104 4105 if (pm == NULL || 4106 !PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 4107 continue; 4108 4109 PMCDBG(PRC,EXT,2, "ppmcs[%d]=%p pm=%p " 4110 "state=%d", ri, pp->pp_pmcs[ri].pp_pmc, 4111 pm, pm->pm_state); 4112 4113 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 4114 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 4115 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 4116 4117 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 4118 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", 4119 __LINE__, pm, ri, pp->pp_pmcs[ri].pp_pmc)); 4120 4121 (void) md->pmd_stop_pmc(cpu, ri); 4122 4123 KASSERT(pm->pm_runcount > 0, 4124 ("[pmc,%d] bad runcount ri %d rc %d", 4125 __LINE__, ri, pm->pm_runcount)); 4126 4127 /* Stop hardware only if it is actually running */ 4128 if (pm->pm_state == PMC_STATE_RUNNING && 4129 pm->pm_stalled == 0) { 4130 md->pmd_read_pmc(cpu, ri, &newvalue); 4131 tmp = newvalue - 4132 PMC_PCPU_SAVED(cpu,ri); 4133 4134 mtx_pool_lock_spin(pmc_mtxpool, pm); 4135 pm->pm_gv.pm_savedvalue += tmp; 4136 pp->pp_pmcs[ri].pp_pmcval += tmp; 4137 mtx_pool_unlock_spin(pmc_mtxpool, pm); 4138 } 4139 4140 atomic_subtract_rel_32(&pm->pm_runcount,1); 4141 4142 KASSERT((int) pm->pm_runcount >= 0, 4143 ("[pmc,%d] runcount is %d", __LINE__, ri)); 4144 4145 (void) md->pmd_config_pmc(cpu, ri, NULL); 4146 } 4147 4148 /* 4149 * Inform the MD layer of this pseudo "context switch 4150 * out" 4151 */ 4152 (void) md->pmd_switch_out(pmc_pcpu[cpu], pp); 4153 4154 critical_exit(); /* ok to be pre-empted now */ 4155 4156 /* 4157 * Unlink this process from the PMCs that are 4158 * targetting it. This will send a signal to 4159 * all PMC owner's whose PMCs are orphaned. 4160 * 4161 * Log PMC value at exit time if requested. 4162 */ 4163 for (ri = 0; ri < md->pmd_npmc; ri++) 4164 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 4165 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 4166 PMC_IS_COUNTING_MODE(PMC_TO_MODE(pm))) 4167 pmclog_process_procexit(pm, pp); 4168 pmc_unlink_target_process(pm, pp); 4169 } 4170 FREE(pp, M_PMC); 4171 4172 } else 4173 critical_exit(); /* pp == NULL */ 4174 4175 4176 /* 4177 * If the process owned PMCs, free them up and free up 4178 * memory. 4179 */ 4180 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 4181 pmc_remove_owner(po); 4182 pmc_destroy_owner_descriptor(po); 4183 } 4184 4185 sx_xunlock(&pmc_sx); 4186 } 4187 4188 /* 4189 * Handle a process fork. 4190 * 4191 * If the parent process 'p1' is under HWPMC monitoring, then copy 4192 * over any attached PMCs that have 'do_descendants' semantics. 4193 */ 4194 4195 static void 4196 pmc_process_fork(void *arg __unused, struct proc *p1, struct proc *newproc, 4197 int flags) 4198 { 4199 int is_using_hwpmcs; 4200 unsigned int ri; 4201 uint32_t do_descendants; 4202 struct pmc *pm; 4203 struct pmc_owner *po; 4204 struct pmc_process *ppnew, *ppold; 4205 4206 (void) flags; /* unused parameter */ 4207 4208 PROC_LOCK(p1); 4209 is_using_hwpmcs = p1->p_flag & P_HWPMC; 4210 PROC_UNLOCK(p1); 4211 4212 /* 4213 * If there are system-wide sampling PMCs active, we need to 4214 * log all fork events to their owner's logs. 4215 */ 4216 4217 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4218 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4219 pmclog_process_procfork(po, p1->p_pid, newproc->p_pid); 4220 4221 if (!is_using_hwpmcs) 4222 return; 4223 4224 PMC_GET_SX_XLOCK(); 4225 PMCDBG(PMC,FRK,1, "process-fork proc=%p (%d, %s) -> %p", p1, 4226 p1->p_pid, p1->p_comm, newproc); 4227 4228 /* 4229 * If the parent process (curthread->td_proc) is a 4230 * target of any PMCs, look for PMCs that are to be 4231 * inherited, and link these into the new process 4232 * descriptor. 4233 */ 4234 if ((ppold = pmc_find_process_descriptor(curthread->td_proc, 4235 PMC_FLAG_NONE)) == NULL) 4236 goto done; /* nothing to do */ 4237 4238 do_descendants = 0; 4239 for (ri = 0; ri < md->pmd_npmc; ri++) 4240 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL) 4241 do_descendants |= pm->pm_flags & PMC_F_DESCENDANTS; 4242 if (do_descendants == 0) /* nothing to do */ 4243 goto done; 4244 4245 /* allocate a descriptor for the new process */ 4246 if ((ppnew = pmc_find_process_descriptor(newproc, 4247 PMC_FLAG_ALLOCATE)) == NULL) 4248 goto done; 4249 4250 /* 4251 * Run through all PMCs that were targeting the old process 4252 * and which specified F_DESCENDANTS and attach them to the 4253 * new process. 4254 * 4255 * Log the fork event to all owners of PMCs attached to this 4256 * process, if not already logged. 4257 */ 4258 for (ri = 0; ri < md->pmd_npmc; ri++) 4259 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL && 4260 (pm->pm_flags & PMC_F_DESCENDANTS)) { 4261 pmc_link_target_process(pm, ppnew); 4262 po = pm->pm_owner; 4263 if (po->po_sscount == 0 && 4264 po->po_flags & PMC_PO_OWNS_LOGFILE) 4265 pmclog_process_procfork(po, p1->p_pid, 4266 newproc->p_pid); 4267 } 4268 4269 /* 4270 * Now mark the new process as being tracked by this driver. 4271 */ 4272 PROC_LOCK(newproc); 4273 newproc->p_flag |= P_HWPMC; 4274 PROC_UNLOCK(newproc); 4275 4276 done: 4277 sx_xunlock(&pmc_sx); 4278 } 4279 4280 4281 /* 4282 * initialization 4283 */ 4284 4285 static const char *pmc_name_of_pmcclass[] = { 4286 #undef __PMC_CLASS 4287 #define __PMC_CLASS(N) #N , 4288 __PMC_CLASSES() 4289 }; 4290 4291 static int 4292 pmc_initialize(void) 4293 { 4294 int cpu, error, n; 4295 struct pmc_binding pb; 4296 struct pmc_sample *ps; 4297 struct pmc_samplebuffer *sb; 4298 4299 md = NULL; 4300 error = 0; 4301 4302 #ifdef DEBUG 4303 /* parse debug flags first */ 4304 if (TUNABLE_STR_FETCH(PMC_SYSCTL_NAME_PREFIX "debugflags", 4305 pmc_debugstr, sizeof(pmc_debugstr))) 4306 pmc_debugflags_parse(pmc_debugstr, 4307 pmc_debugstr+strlen(pmc_debugstr)); 4308 #endif 4309 4310 PMCDBG(MOD,INI,0, "PMC Initialize (version %x)", PMC_VERSION); 4311 4312 /* check kernel version */ 4313 if (pmc_kernel_version != PMC_VERSION) { 4314 if (pmc_kernel_version == 0) 4315 printf("hwpmc: this kernel has not been compiled with " 4316 "'options HWPMC_HOOKS'.\n"); 4317 else 4318 printf("hwpmc: kernel version (0x%x) does not match " 4319 "module version (0x%x).\n", pmc_kernel_version, 4320 PMC_VERSION); 4321 return EPROGMISMATCH; 4322 } 4323 4324 /* 4325 * check sysctl parameters 4326 */ 4327 4328 if (pmc_hashsize <= 0) { 4329 (void) printf("hwpmc: tunable \"hashsize\"=%d must be " 4330 "greater than zero.\n", pmc_hashsize); 4331 pmc_hashsize = PMC_HASH_SIZE; 4332 } 4333 4334 if (pmc_nsamples <= 0 || pmc_nsamples > 65535) { 4335 (void) printf("hwpmc: tunable \"nsamples\"=%d out of " 4336 "range.\n", pmc_nsamples); 4337 pmc_nsamples = PMC_NSAMPLES; 4338 } 4339 4340 if (pmc_callchaindepth <= 0 || 4341 pmc_callchaindepth > PMC_CALLCHAIN_DEPTH_MAX) { 4342 (void) printf("hwpmc: tunable \"callchaindepth\"=%d out of " 4343 "range.\n", pmc_callchaindepth); 4344 pmc_callchaindepth = PMC_CALLCHAIN_DEPTH; 4345 } 4346 4347 md = pmc_md_initialize(); 4348 4349 if (md == NULL || md->pmd_init == NULL) 4350 return ENOSYS; 4351 4352 /* allocate space for the per-cpu array */ 4353 MALLOC(pmc_pcpu, struct pmc_cpu **, mp_ncpus * sizeof(struct pmc_cpu *), 4354 M_PMC, M_WAITOK|M_ZERO); 4355 4356 /* per-cpu 'saved values' for managing process-mode PMCs */ 4357 MALLOC(pmc_pcpu_saved, pmc_value_t *, 4358 sizeof(pmc_value_t) * mp_ncpus * md->pmd_npmc, M_PMC, M_WAITOK); 4359 4360 /* perform cpu dependent initialization */ 4361 pmc_save_cpu_binding(&pb); 4362 for (cpu = 0; cpu < mp_ncpus; cpu++) { 4363 if (pmc_cpu_is_disabled(cpu)) 4364 continue; 4365 pmc_select_cpu(cpu); 4366 if ((error = md->pmd_init(cpu)) != 0) 4367 break; 4368 } 4369 pmc_restore_cpu_binding(&pb); 4370 4371 if (error != 0) 4372 return error; 4373 4374 /* allocate space for the sample array */ 4375 for (cpu = 0; cpu < mp_ncpus; cpu++) { 4376 if (pmc_cpu_is_disabled(cpu)) 4377 continue; 4378 MALLOC(sb, struct pmc_samplebuffer *, 4379 sizeof(struct pmc_samplebuffer) + 4380 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 4381 M_WAITOK|M_ZERO); 4382 4383 sb->ps_read = sb->ps_write = sb->ps_samples; 4384 sb->ps_fence = sb->ps_samples + pmc_nsamples; 4385 KASSERT(pmc_pcpu[cpu] != NULL, 4386 ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu)); 4387 4388 MALLOC(sb->ps_callchains, uintptr_t *, 4389 pmc_callchaindepth * pmc_nsamples * sizeof(uintptr_t), 4390 M_PMC, M_WAITOK|M_ZERO); 4391 4392 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 4393 ps->ps_pc = sb->ps_callchains + 4394 (n * pmc_callchaindepth); 4395 4396 pmc_pcpu[cpu]->pc_sb = sb; 4397 } 4398 4399 /* allocate space for the row disposition array */ 4400 pmc_pmcdisp = malloc(sizeof(enum pmc_mode) * md->pmd_npmc, 4401 M_PMC, M_WAITOK|M_ZERO); 4402 4403 KASSERT(pmc_pmcdisp != NULL, 4404 ("[pmc,%d] pmcdisp allocation returned NULL", __LINE__)); 4405 4406 /* mark all PMCs as available */ 4407 for (n = 0; n < (int) md->pmd_npmc; n++) 4408 PMC_MARK_ROW_FREE(n); 4409 4410 /* allocate thread hash tables */ 4411 pmc_ownerhash = hashinit(pmc_hashsize, M_PMC, 4412 &pmc_ownerhashmask); 4413 4414 pmc_processhash = hashinit(pmc_hashsize, M_PMC, 4415 &pmc_processhashmask); 4416 mtx_init(&pmc_processhash_mtx, "pmc-process-hash", "pmc-leaf", 4417 MTX_SPIN); 4418 4419 LIST_INIT(&pmc_ss_owners); 4420 pmc_ss_count = 0; 4421 4422 /* allocate a pool of spin mutexes */ 4423 pmc_mtxpool = mtx_pool_create("pmc-leaf", pmc_mtxpool_size, 4424 MTX_SPIN); 4425 4426 PMCDBG(MOD,INI,1, "pmc_ownerhash=%p, mask=0x%lx " 4427 "targethash=%p mask=0x%lx", pmc_ownerhash, pmc_ownerhashmask, 4428 pmc_processhash, pmc_processhashmask); 4429 4430 /* register process {exit,fork,exec} handlers */ 4431 pmc_exit_tag = EVENTHANDLER_REGISTER(process_exit, 4432 pmc_process_exit, NULL, EVENTHANDLER_PRI_ANY); 4433 pmc_fork_tag = EVENTHANDLER_REGISTER(process_fork, 4434 pmc_process_fork, NULL, EVENTHANDLER_PRI_ANY); 4435 4436 /* initialize logging */ 4437 pmclog_initialize(); 4438 4439 /* set hook functions */ 4440 pmc_intr = md->pmd_intr; 4441 pmc_hook = pmc_hook_handler; 4442 4443 if (error == 0) { 4444 printf(PMC_MODULE_NAME ":"); 4445 for (n = 0; n < (int) md->pmd_nclass; n++) { 4446 printf(" %s/%d/0x%b", 4447 pmc_name_of_pmcclass[md->pmd_classes[n].pm_class], 4448 md->pmd_nclasspmcs[n], 4449 md->pmd_classes[n].pm_caps, 4450 "\20" 4451 "\1INT\2USR\3SYS\4EDG\5THR" 4452 "\6REA\7WRI\10INV\11QUA\12PRC" 4453 "\13TAG\14CSC"); 4454 } 4455 printf("\n"); 4456 } 4457 4458 return error; 4459 } 4460 4461 /* prepare to be unloaded */ 4462 static void 4463 pmc_cleanup(void) 4464 { 4465 int cpu; 4466 struct pmc_ownerhash *ph; 4467 struct pmc_owner *po, *tmp; 4468 struct pmc_binding pb; 4469 #ifdef DEBUG 4470 struct pmc_processhash *prh; 4471 #endif 4472 4473 PMCDBG(MOD,INI,0, "%s", "cleanup"); 4474 4475 /* switch off sampling */ 4476 atomic_store_rel_int(&pmc_cpumask, 0); 4477 pmc_intr = NULL; 4478 4479 sx_xlock(&pmc_sx); 4480 if (pmc_hook == NULL) { /* being unloaded already */ 4481 sx_xunlock(&pmc_sx); 4482 return; 4483 } 4484 4485 pmc_hook = NULL; /* prevent new threads from entering module */ 4486 4487 /* deregister event handlers */ 4488 EVENTHANDLER_DEREGISTER(process_fork, pmc_fork_tag); 4489 EVENTHANDLER_DEREGISTER(process_exit, pmc_exit_tag); 4490 4491 /* send SIGBUS to all owner threads, free up allocations */ 4492 if (pmc_ownerhash) 4493 for (ph = pmc_ownerhash; 4494 ph <= &pmc_ownerhash[pmc_ownerhashmask]; 4495 ph++) { 4496 LIST_FOREACH_SAFE(po, ph, po_next, tmp) { 4497 pmc_remove_owner(po); 4498 4499 /* send SIGBUS to owner processes */ 4500 PMCDBG(MOD,INI,2, "cleanup signal proc=%p " 4501 "(%d, %s)", po->po_owner, 4502 po->po_owner->p_pid, 4503 po->po_owner->p_comm); 4504 4505 PROC_LOCK(po->po_owner); 4506 psignal(po->po_owner, SIGBUS); 4507 PROC_UNLOCK(po->po_owner); 4508 4509 pmc_destroy_owner_descriptor(po); 4510 } 4511 } 4512 4513 /* reclaim allocated data structures */ 4514 if (pmc_mtxpool) 4515 mtx_pool_destroy(&pmc_mtxpool); 4516 4517 mtx_destroy(&pmc_processhash_mtx); 4518 if (pmc_processhash) { 4519 #ifdef DEBUG 4520 struct pmc_process *pp; 4521 4522 PMCDBG(MOD,INI,3, "%s", "destroy process hash"); 4523 for (prh = pmc_processhash; 4524 prh <= &pmc_processhash[pmc_processhashmask]; 4525 prh++) 4526 LIST_FOREACH(pp, prh, pp_next) 4527 PMCDBG(MOD,INI,3, "pid=%d", pp->pp_proc->p_pid); 4528 #endif 4529 4530 hashdestroy(pmc_processhash, M_PMC, pmc_processhashmask); 4531 pmc_processhash = NULL; 4532 } 4533 4534 if (pmc_ownerhash) { 4535 PMCDBG(MOD,INI,3, "%s", "destroy owner hash"); 4536 hashdestroy(pmc_ownerhash, M_PMC, pmc_ownerhashmask); 4537 pmc_ownerhash = NULL; 4538 } 4539 4540 KASSERT(LIST_EMPTY(&pmc_ss_owners), 4541 ("[pmc,%d] Global SS owner list not empty", __LINE__)); 4542 KASSERT(pmc_ss_count == 0, 4543 ("[pmc,%d] Global SS count not empty", __LINE__)); 4544 4545 /* free the per-cpu sample buffers */ 4546 for (cpu = 0; cpu < mp_ncpus; cpu++) { 4547 if (pmc_cpu_is_disabled(cpu)) 4548 continue; 4549 KASSERT(pmc_pcpu[cpu]->pc_sb != NULL, 4550 ("[pmc,%d] Null cpu sample buffer cpu=%d", __LINE__, 4551 cpu)); 4552 FREE(pmc_pcpu[cpu]->pc_sb->ps_callchains, M_PMC); 4553 FREE(pmc_pcpu[cpu]->pc_sb, M_PMC); 4554 pmc_pcpu[cpu]->pc_sb = NULL; 4555 } 4556 4557 /* do processor dependent cleanup */ 4558 PMCDBG(MOD,INI,3, "%s", "md cleanup"); 4559 if (md) { 4560 pmc_save_cpu_binding(&pb); 4561 for (cpu = 0; cpu < mp_ncpus; cpu++) { 4562 PMCDBG(MOD,INI,1,"pmc-cleanup cpu=%d pcs=%p", 4563 cpu, pmc_pcpu[cpu]); 4564 if (pmc_cpu_is_disabled(cpu)) 4565 continue; 4566 pmc_select_cpu(cpu); 4567 if (pmc_pcpu[cpu]) 4568 (void) md->pmd_cleanup(cpu); 4569 } 4570 FREE(md, M_PMC); 4571 md = NULL; 4572 pmc_restore_cpu_binding(&pb); 4573 } 4574 4575 /* deallocate per-cpu structures */ 4576 FREE(pmc_pcpu, M_PMC); 4577 pmc_pcpu = NULL; 4578 4579 FREE(pmc_pcpu_saved, M_PMC); 4580 pmc_pcpu_saved = NULL; 4581 4582 if (pmc_pmcdisp) { 4583 FREE(pmc_pmcdisp, M_PMC); 4584 pmc_pmcdisp = NULL; 4585 } 4586 4587 pmclog_shutdown(); 4588 4589 sx_xunlock(&pmc_sx); /* we are done */ 4590 } 4591 4592 /* 4593 * The function called at load/unload. 4594 */ 4595 4596 static int 4597 load (struct module *module __unused, int cmd, void *arg __unused) 4598 { 4599 int error; 4600 4601 error = 0; 4602 4603 switch (cmd) { 4604 case MOD_LOAD : 4605 /* initialize the subsystem */ 4606 error = pmc_initialize(); 4607 if (error != 0) 4608 break; 4609 PMCDBG(MOD,INI,1, "syscall=%d ncpus=%d", 4610 pmc_syscall_num, mp_ncpus); 4611 break; 4612 4613 4614 case MOD_UNLOAD : 4615 case MOD_SHUTDOWN: 4616 pmc_cleanup(); 4617 PMCDBG(MOD,INI,1, "%s", "unloaded"); 4618 break; 4619 4620 default : 4621 error = EINVAL; /* XXX should panic(9) */ 4622 break; 4623 } 4624 4625 return error; 4626 } 4627 4628 /* memory pool */ 4629 MALLOC_DEFINE(M_PMC, "pmc", "Memory space for the PMC module"); 4630