1 /*- 2 * Copyright (c) 2003-2008 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/mount.h> 45 #include <sys/mutex.h> 46 #include <sys/pmc.h> 47 #include <sys/pmckern.h> 48 #include <sys/pmclog.h> 49 #include <sys/priv.h> 50 #include <sys/proc.h> 51 #include <sys/queue.h> 52 #include <sys/resourcevar.h> 53 #include <sys/rwlock.h> 54 #include <sys/sched.h> 55 #include <sys/signalvar.h> 56 #include <sys/smp.h> 57 #include <sys/sx.h> 58 #include <sys/sysctl.h> 59 #include <sys/sysent.h> 60 #include <sys/systm.h> 61 #include <sys/vnode.h> 62 63 #include <sys/linker.h> /* needs to be after <sys/malloc.h> */ 64 65 #include <machine/atomic.h> 66 #include <machine/md_var.h> 67 68 #include <vm/vm.h> 69 #include <vm/vm_extern.h> 70 #include <vm/pmap.h> 71 #include <vm/vm_map.h> 72 #include <vm/vm_object.h> 73 74 #include "hwpmc_soft.h" 75 76 /* 77 * Types 78 */ 79 80 enum pmc_flags { 81 PMC_FLAG_NONE = 0x00, /* do nothing */ 82 PMC_FLAG_REMOVE = 0x01, /* atomically remove entry from hash */ 83 PMC_FLAG_ALLOCATE = 0x02, /* add entry to hash if not found */ 84 }; 85 86 /* 87 * The offset in sysent where the syscall is allocated. 88 */ 89 90 static int pmc_syscall_num = NO_SYSCALL; 91 struct pmc_cpu **pmc_pcpu; /* per-cpu state */ 92 pmc_value_t *pmc_pcpu_saved; /* saved PMC values: CSW handling */ 93 94 #define PMC_PCPU_SAVED(C,R) pmc_pcpu_saved[(R) + md->pmd_npmc*(C)] 95 96 struct mtx_pool *pmc_mtxpool; 97 static int *pmc_pmcdisp; /* PMC row dispositions */ 98 99 #define PMC_ROW_DISP_IS_FREE(R) (pmc_pmcdisp[(R)] == 0) 100 #define PMC_ROW_DISP_IS_THREAD(R) (pmc_pmcdisp[(R)] > 0) 101 #define PMC_ROW_DISP_IS_STANDALONE(R) (pmc_pmcdisp[(R)] < 0) 102 103 #define PMC_MARK_ROW_FREE(R) do { \ 104 pmc_pmcdisp[(R)] = 0; \ 105 } while (0) 106 107 #define PMC_MARK_ROW_STANDALONE(R) do { \ 108 KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \ 109 __LINE__)); \ 110 atomic_add_int(&pmc_pmcdisp[(R)], -1); \ 111 KASSERT(pmc_pmcdisp[(R)] >= (-pmc_cpu_max_active()), \ 112 ("[pmc,%d] row disposition error", __LINE__)); \ 113 } while (0) 114 115 #define PMC_UNMARK_ROW_STANDALONE(R) do { \ 116 atomic_add_int(&pmc_pmcdisp[(R)], 1); \ 117 KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \ 118 __LINE__)); \ 119 } while (0) 120 121 #define PMC_MARK_ROW_THREAD(R) do { \ 122 KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \ 123 __LINE__)); \ 124 atomic_add_int(&pmc_pmcdisp[(R)], 1); \ 125 } while (0) 126 127 #define PMC_UNMARK_ROW_THREAD(R) do { \ 128 atomic_add_int(&pmc_pmcdisp[(R)], -1); \ 129 KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \ 130 __LINE__)); \ 131 } while (0) 132 133 134 /* various event handlers */ 135 static eventhandler_tag pmc_exit_tag, pmc_fork_tag, pmc_kld_load_tag, 136 pmc_kld_unload_tag; 137 138 /* Module statistics */ 139 struct pmc_op_getdriverstats pmc_stats; 140 141 /* Machine/processor dependent operations */ 142 static struct pmc_mdep *md; 143 144 /* 145 * Hash tables mapping owner processes and target threads to PMCs. 146 */ 147 148 struct mtx pmc_processhash_mtx; /* spin mutex */ 149 static u_long pmc_processhashmask; 150 static LIST_HEAD(pmc_processhash, pmc_process) *pmc_processhash; 151 152 /* 153 * Hash table of PMC owner descriptors. This table is protected by 154 * the shared PMC "sx" lock. 155 */ 156 157 static u_long pmc_ownerhashmask; 158 static LIST_HEAD(pmc_ownerhash, pmc_owner) *pmc_ownerhash; 159 160 /* 161 * List of PMC owners with system-wide sampling PMCs. 162 */ 163 164 static LIST_HEAD(, pmc_owner) pmc_ss_owners; 165 166 167 /* 168 * A map of row indices to classdep structures. 169 */ 170 static struct pmc_classdep **pmc_rowindex_to_classdep; 171 172 /* 173 * Prototypes 174 */ 175 176 #ifdef DEBUG 177 static int pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS); 178 static int pmc_debugflags_parse(char *newstr, char *fence); 179 #endif 180 181 static int load(struct module *module, int cmd, void *arg); 182 static int pmc_attach_process(struct proc *p, struct pmc *pm); 183 static struct pmc *pmc_allocate_pmc_descriptor(void); 184 static struct pmc_owner *pmc_allocate_owner_descriptor(struct proc *p); 185 static int pmc_attach_one_process(struct proc *p, struct pmc *pm); 186 static int pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, 187 int cpu); 188 static int pmc_can_attach(struct pmc *pm, struct proc *p); 189 static void pmc_capture_user_callchain(int cpu, int soft, struct trapframe *tf); 190 static void pmc_cleanup(void); 191 static int pmc_detach_process(struct proc *p, struct pmc *pm); 192 static int pmc_detach_one_process(struct proc *p, struct pmc *pm, 193 int flags); 194 static void pmc_destroy_owner_descriptor(struct pmc_owner *po); 195 static struct pmc_owner *pmc_find_owner_descriptor(struct proc *p); 196 static int pmc_find_pmc(pmc_id_t pmcid, struct pmc **pm); 197 static struct pmc *pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, 198 pmc_id_t pmc); 199 static struct pmc_process *pmc_find_process_descriptor(struct proc *p, 200 uint32_t mode); 201 static void pmc_force_context_switch(void); 202 static void pmc_link_target_process(struct pmc *pm, 203 struct pmc_process *pp); 204 static void pmc_log_all_process_mappings(struct pmc_owner *po); 205 static void pmc_log_kernel_mappings(struct pmc *pm); 206 static void pmc_log_process_mappings(struct pmc_owner *po, struct proc *p); 207 static void pmc_maybe_remove_owner(struct pmc_owner *po); 208 static void pmc_process_csw_in(struct thread *td); 209 static void pmc_process_csw_out(struct thread *td); 210 static void pmc_process_exit(void *arg, struct proc *p); 211 static void pmc_process_fork(void *arg, struct proc *p1, 212 struct proc *p2, int n); 213 static void pmc_process_samples(int cpu, int soft); 214 static void pmc_release_pmc_descriptor(struct pmc *pmc); 215 static void pmc_remove_owner(struct pmc_owner *po); 216 static void pmc_remove_process_descriptor(struct pmc_process *pp); 217 static void pmc_restore_cpu_binding(struct pmc_binding *pb); 218 static void pmc_save_cpu_binding(struct pmc_binding *pb); 219 static void pmc_select_cpu(int cpu); 220 static int pmc_start(struct pmc *pm); 221 static int pmc_stop(struct pmc *pm); 222 static int pmc_syscall_handler(struct thread *td, void *syscall_args); 223 static void pmc_unlink_target_process(struct pmc *pmc, 224 struct pmc_process *pp); 225 static int generic_switch_in(struct pmc_cpu *pc, struct pmc_process *pp); 226 static int generic_switch_out(struct pmc_cpu *pc, struct pmc_process *pp); 227 static struct pmc_mdep *pmc_generic_cpu_initialize(void); 228 static void pmc_generic_cpu_finalize(struct pmc_mdep *md); 229 230 /* 231 * Kernel tunables and sysctl(8) interface. 232 */ 233 234 SYSCTL_DECL(_kern_hwpmc); 235 236 static int pmc_callchaindepth = PMC_CALLCHAIN_DEPTH; 237 TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "callchaindepth", &pmc_callchaindepth); 238 SYSCTL_INT(_kern_hwpmc, OID_AUTO, callchaindepth, CTLFLAG_TUN|CTLFLAG_RD, 239 &pmc_callchaindepth, 0, "depth of call chain records"); 240 241 #ifdef DEBUG 242 struct pmc_debugflags pmc_debugflags = PMC_DEBUG_DEFAULT_FLAGS; 243 char pmc_debugstr[PMC_DEBUG_STRSIZE]; 244 TUNABLE_STR(PMC_SYSCTL_NAME_PREFIX "debugflags", pmc_debugstr, 245 sizeof(pmc_debugstr)); 246 SYSCTL_PROC(_kern_hwpmc, OID_AUTO, debugflags, 247 CTLTYPE_STRING|CTLFLAG_RW|CTLFLAG_TUN, 248 0, 0, pmc_debugflags_sysctl_handler, "A", "debug flags"); 249 #endif 250 251 /* 252 * kern.hwpmc.hashrows -- determines the number of rows in the 253 * of the hash table used to look up threads 254 */ 255 256 static int pmc_hashsize = PMC_HASH_SIZE; 257 TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "hashsize", &pmc_hashsize); 258 SYSCTL_INT(_kern_hwpmc, OID_AUTO, hashsize, CTLFLAG_TUN|CTLFLAG_RD, 259 &pmc_hashsize, 0, "rows in hash tables"); 260 261 /* 262 * kern.hwpmc.nsamples --- number of PC samples/callchain stacks per CPU 263 */ 264 265 static int pmc_nsamples = PMC_NSAMPLES; 266 TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "nsamples", &pmc_nsamples); 267 SYSCTL_INT(_kern_hwpmc, OID_AUTO, nsamples, CTLFLAG_TUN|CTLFLAG_RD, 268 &pmc_nsamples, 0, "number of PC samples per CPU"); 269 270 271 /* 272 * kern.hwpmc.mtxpoolsize -- number of mutexes in the mutex pool. 273 */ 274 275 static int pmc_mtxpool_size = PMC_MTXPOOL_SIZE; 276 TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "mtxpoolsize", &pmc_mtxpool_size); 277 SYSCTL_INT(_kern_hwpmc, OID_AUTO, mtxpoolsize, CTLFLAG_TUN|CTLFLAG_RD, 278 &pmc_mtxpool_size, 0, "size of spin mutex pool"); 279 280 281 /* 282 * security.bsd.unprivileged_syspmcs -- allow non-root processes to 283 * allocate system-wide PMCs. 284 * 285 * Allowing unprivileged processes to allocate system PMCs is convenient 286 * if system-wide measurements need to be taken concurrently with other 287 * per-process measurements. This feature is turned off by default. 288 */ 289 290 static int pmc_unprivileged_syspmcs = 0; 291 TUNABLE_INT("security.bsd.unprivileged_syspmcs", &pmc_unprivileged_syspmcs); 292 SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_syspmcs, CTLFLAG_RW, 293 &pmc_unprivileged_syspmcs, 0, 294 "allow unprivileged process to allocate system PMCs"); 295 296 /* 297 * Hash function. Discard the lower 2 bits of the pointer since 298 * these are always zero for our uses. The hash multiplier is 299 * round((2^LONG_BIT) * ((sqrt(5)-1)/2)). 300 */ 301 302 #if LONG_BIT == 64 303 #define _PMC_HM 11400714819323198486u 304 #elif LONG_BIT == 32 305 #define _PMC_HM 2654435769u 306 #else 307 #error Must know the size of 'long' to compile 308 #endif 309 310 #define PMC_HASH_PTR(P,M) ((((unsigned long) (P) >> 2) * _PMC_HM) & (M)) 311 312 /* 313 * Syscall structures 314 */ 315 316 /* The `sysent' for the new syscall */ 317 static struct sysent pmc_sysent = { 318 2, /* sy_narg */ 319 pmc_syscall_handler /* sy_call */ 320 }; 321 322 static struct syscall_module_data pmc_syscall_mod = { 323 load, 324 NULL, 325 &pmc_syscall_num, 326 &pmc_sysent, 327 { 0, NULL } 328 }; 329 330 static moduledata_t pmc_mod = { 331 PMC_MODULE_NAME, 332 syscall_module_handler, 333 &pmc_syscall_mod 334 }; 335 336 DECLARE_MODULE(pmc, pmc_mod, SI_SUB_SMP, SI_ORDER_ANY); 337 MODULE_VERSION(pmc, PMC_VERSION); 338 339 #ifdef DEBUG 340 enum pmc_dbgparse_state { 341 PMCDS_WS, /* in whitespace */ 342 PMCDS_MAJOR, /* seen a major keyword */ 343 PMCDS_MINOR 344 }; 345 346 static int 347 pmc_debugflags_parse(char *newstr, char *fence) 348 { 349 char c, *p, *q; 350 struct pmc_debugflags *tmpflags; 351 int error, found, *newbits, tmp; 352 size_t kwlen; 353 354 tmpflags = malloc(sizeof(*tmpflags), M_PMC, M_WAITOK|M_ZERO); 355 356 p = newstr; 357 error = 0; 358 359 for (; p < fence && (c = *p); p++) { 360 361 /* skip white space */ 362 if (c == ' ' || c == '\t') 363 continue; 364 365 /* look for a keyword followed by "=" */ 366 for (q = p; p < fence && (c = *p) && c != '='; p++) 367 ; 368 if (c != '=') { 369 error = EINVAL; 370 goto done; 371 } 372 373 kwlen = p - q; 374 newbits = NULL; 375 376 /* lookup flag group name */ 377 #define DBG_SET_FLAG_MAJ(S,F) \ 378 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \ 379 newbits = &tmpflags->pdb_ ## F; 380 381 DBG_SET_FLAG_MAJ("cpu", CPU); 382 DBG_SET_FLAG_MAJ("csw", CSW); 383 DBG_SET_FLAG_MAJ("logging", LOG); 384 DBG_SET_FLAG_MAJ("module", MOD); 385 DBG_SET_FLAG_MAJ("md", MDP); 386 DBG_SET_FLAG_MAJ("owner", OWN); 387 DBG_SET_FLAG_MAJ("pmc", PMC); 388 DBG_SET_FLAG_MAJ("process", PRC); 389 DBG_SET_FLAG_MAJ("sampling", SAM); 390 391 if (newbits == NULL) { 392 error = EINVAL; 393 goto done; 394 } 395 396 p++; /* skip the '=' */ 397 398 /* Now parse the individual flags */ 399 tmp = 0; 400 newflag: 401 for (q = p; p < fence && (c = *p); p++) 402 if (c == ' ' || c == '\t' || c == ',') 403 break; 404 405 /* p == fence or c == ws or c == "," or c == 0 */ 406 407 if ((kwlen = p - q) == 0) { 408 *newbits = tmp; 409 continue; 410 } 411 412 found = 0; 413 #define DBG_SET_FLAG_MIN(S,F) \ 414 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \ 415 tmp |= found = (1 << PMC_DEBUG_MIN_ ## F) 416 417 /* a '*' denotes all possible flags in the group */ 418 if (kwlen == 1 && *q == '*') 419 tmp = found = ~0; 420 /* look for individual flag names */ 421 DBG_SET_FLAG_MIN("allocaterow", ALR); 422 DBG_SET_FLAG_MIN("allocate", ALL); 423 DBG_SET_FLAG_MIN("attach", ATT); 424 DBG_SET_FLAG_MIN("bind", BND); 425 DBG_SET_FLAG_MIN("config", CFG); 426 DBG_SET_FLAG_MIN("exec", EXC); 427 DBG_SET_FLAG_MIN("exit", EXT); 428 DBG_SET_FLAG_MIN("find", FND); 429 DBG_SET_FLAG_MIN("flush", FLS); 430 DBG_SET_FLAG_MIN("fork", FRK); 431 DBG_SET_FLAG_MIN("getbuf", GTB); 432 DBG_SET_FLAG_MIN("hook", PMH); 433 DBG_SET_FLAG_MIN("init", INI); 434 DBG_SET_FLAG_MIN("intr", INT); 435 DBG_SET_FLAG_MIN("linktarget", TLK); 436 DBG_SET_FLAG_MIN("mayberemove", OMR); 437 DBG_SET_FLAG_MIN("ops", OPS); 438 DBG_SET_FLAG_MIN("read", REA); 439 DBG_SET_FLAG_MIN("register", REG); 440 DBG_SET_FLAG_MIN("release", REL); 441 DBG_SET_FLAG_MIN("remove", ORM); 442 DBG_SET_FLAG_MIN("sample", SAM); 443 DBG_SET_FLAG_MIN("scheduleio", SIO); 444 DBG_SET_FLAG_MIN("select", SEL); 445 DBG_SET_FLAG_MIN("signal", SIG); 446 DBG_SET_FLAG_MIN("swi", SWI); 447 DBG_SET_FLAG_MIN("swo", SWO); 448 DBG_SET_FLAG_MIN("start", STA); 449 DBG_SET_FLAG_MIN("stop", STO); 450 DBG_SET_FLAG_MIN("syscall", PMS); 451 DBG_SET_FLAG_MIN("unlinktarget", TUL); 452 DBG_SET_FLAG_MIN("write", WRI); 453 if (found == 0) { 454 /* unrecognized flag name */ 455 error = EINVAL; 456 goto done; 457 } 458 459 if (c == 0 || c == ' ' || c == '\t') { /* end of flag group */ 460 *newbits = tmp; 461 continue; 462 } 463 464 p++; 465 goto newflag; 466 } 467 468 /* save the new flag set */ 469 bcopy(tmpflags, &pmc_debugflags, sizeof(pmc_debugflags)); 470 471 done: 472 free(tmpflags, M_PMC); 473 return error; 474 } 475 476 static int 477 pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS) 478 { 479 char *fence, *newstr; 480 int error; 481 unsigned int n; 482 483 (void) arg1; (void) arg2; /* unused parameters */ 484 485 n = sizeof(pmc_debugstr); 486 newstr = malloc(n, M_PMC, M_WAITOK|M_ZERO); 487 (void) strlcpy(newstr, pmc_debugstr, n); 488 489 error = sysctl_handle_string(oidp, newstr, n, req); 490 491 /* if there is a new string, parse and copy it */ 492 if (error == 0 && req->newptr != NULL) { 493 fence = newstr + (n < req->newlen ? n : req->newlen + 1); 494 if ((error = pmc_debugflags_parse(newstr, fence)) == 0) 495 (void) strlcpy(pmc_debugstr, newstr, 496 sizeof(pmc_debugstr)); 497 } 498 499 free(newstr, M_PMC); 500 501 return error; 502 } 503 #endif 504 505 /* 506 * Map a row index to a classdep structure and return the adjusted row 507 * index for the PMC class index. 508 */ 509 static struct pmc_classdep * 510 pmc_ri_to_classdep(struct pmc_mdep *md, int ri, int *adjri) 511 { 512 struct pmc_classdep *pcd; 513 514 (void) md; 515 516 KASSERT(ri >= 0 && ri < md->pmd_npmc, 517 ("[pmc,%d] illegal row-index %d", __LINE__, ri)); 518 519 pcd = pmc_rowindex_to_classdep[ri]; 520 521 KASSERT(pcd != NULL, 522 ("[pmc,%d] ri %d null pcd", __LINE__, ri)); 523 524 *adjri = ri - pcd->pcd_ri; 525 526 KASSERT(*adjri >= 0 && *adjri < pcd->pcd_num, 527 ("[pmc,%d] adjusted row-index %d", __LINE__, *adjri)); 528 529 return (pcd); 530 } 531 532 /* 533 * Concurrency Control 534 * 535 * The driver manages the following data structures: 536 * 537 * - target process descriptors, one per target process 538 * - owner process descriptors (and attached lists), one per owner process 539 * - lookup hash tables for owner and target processes 540 * - PMC descriptors (and attached lists) 541 * - per-cpu hardware state 542 * - the 'hook' variable through which the kernel calls into 543 * this module 544 * - the machine hardware state (managed by the MD layer) 545 * 546 * These data structures are accessed from: 547 * 548 * - thread context-switch code 549 * - interrupt handlers (possibly on multiple cpus) 550 * - kernel threads on multiple cpus running on behalf of user 551 * processes doing system calls 552 * - this driver's private kernel threads 553 * 554 * = Locks and Locking strategy = 555 * 556 * The driver uses four locking strategies for its operation: 557 * 558 * - The global SX lock "pmc_sx" is used to protect internal 559 * data structures. 560 * 561 * Calls into the module by syscall() start with this lock being 562 * held in exclusive mode. Depending on the requested operation, 563 * the lock may be downgraded to 'shared' mode to allow more 564 * concurrent readers into the module. Calls into the module from 565 * other parts of the kernel acquire the lock in shared mode. 566 * 567 * This SX lock is held in exclusive mode for any operations that 568 * modify the linkages between the driver's internal data structures. 569 * 570 * The 'pmc_hook' function pointer is also protected by this lock. 571 * It is only examined with the sx lock held in exclusive mode. The 572 * kernel module is allowed to be unloaded only with the sx lock held 573 * in exclusive mode. In normal syscall handling, after acquiring the 574 * pmc_sx lock we first check that 'pmc_hook' is non-null before 575 * proceeding. This prevents races between the thread unloading the module 576 * and other threads seeking to use the module. 577 * 578 * - Lookups of target process structures and owner process structures 579 * cannot use the global "pmc_sx" SX lock because these lookups need 580 * to happen during context switches and in other critical sections 581 * where sleeping is not allowed. We protect these lookup tables 582 * with their own private spin-mutexes, "pmc_processhash_mtx" and 583 * "pmc_ownerhash_mtx". 584 * 585 * - Interrupt handlers work in a lock free manner. At interrupt 586 * time, handlers look at the PMC pointer (phw->phw_pmc) configured 587 * when the PMC was started. If this pointer is NULL, the interrupt 588 * is ignored after updating driver statistics. We ensure that this 589 * pointer is set (using an atomic operation if necessary) before the 590 * PMC hardware is started. Conversely, this pointer is unset atomically 591 * only after the PMC hardware is stopped. 592 * 593 * We ensure that everything needed for the operation of an 594 * interrupt handler is available without it needing to acquire any 595 * locks. We also ensure that a PMC's software state is destroyed only 596 * after the PMC is taken off hardware (on all CPUs). 597 * 598 * - Context-switch handling with process-private PMCs needs more 599 * care. 600 * 601 * A given process may be the target of multiple PMCs. For example, 602 * PMCATTACH and PMCDETACH may be requested by a process on one CPU 603 * while the target process is running on another. A PMC could also 604 * be getting released because its owner is exiting. We tackle 605 * these situations in the following manner: 606 * 607 * - each target process structure 'pmc_process' has an array 608 * of 'struct pmc *' pointers, one for each hardware PMC. 609 * 610 * - At context switch IN time, each "target" PMC in RUNNING state 611 * gets started on hardware and a pointer to each PMC is copied into 612 * the per-cpu phw array. The 'runcount' for the PMC is 613 * incremented. 614 * 615 * - At context switch OUT time, all process-virtual PMCs are stopped 616 * on hardware. The saved value is added to the PMCs value field 617 * only if the PMC is in a non-deleted state (the PMCs state could 618 * have changed during the current time slice). 619 * 620 * Note that since in-between a switch IN on a processor and a switch 621 * OUT, the PMC could have been released on another CPU. Therefore 622 * context switch OUT always looks at the hardware state to turn 623 * OFF PMCs and will update a PMC's saved value only if reachable 624 * from the target process record. 625 * 626 * - OP PMCRELEASE could be called on a PMC at any time (the PMC could 627 * be attached to many processes at the time of the call and could 628 * be active on multiple CPUs). 629 * 630 * We prevent further scheduling of the PMC by marking it as in 631 * state 'DELETED'. If the runcount of the PMC is non-zero then 632 * this PMC is currently running on a CPU somewhere. The thread 633 * doing the PMCRELEASE operation waits by repeatedly doing a 634 * pause() till the runcount comes to zero. 635 * 636 * The contents of a PMC descriptor (struct pmc) are protected using 637 * a spin-mutex. In order to save space, we use a mutex pool. 638 * 639 * In terms of lock types used by witness(4), we use: 640 * - Type "pmc-sx", used by the global SX lock. 641 * - Type "pmc-sleep", for sleep mutexes used by logger threads. 642 * - Type "pmc-per-proc", for protecting PMC owner descriptors. 643 * - Type "pmc-leaf", used for all other spin mutexes. 644 */ 645 646 /* 647 * save the cpu binding of the current kthread 648 */ 649 650 static void 651 pmc_save_cpu_binding(struct pmc_binding *pb) 652 { 653 PMCDBG(CPU,BND,2, "%s", "save-cpu"); 654 thread_lock(curthread); 655 pb->pb_bound = sched_is_bound(curthread); 656 pb->pb_cpu = curthread->td_oncpu; 657 thread_unlock(curthread); 658 PMCDBG(CPU,BND,2, "save-cpu cpu=%d", pb->pb_cpu); 659 } 660 661 /* 662 * restore the cpu binding of the current thread 663 */ 664 665 static void 666 pmc_restore_cpu_binding(struct pmc_binding *pb) 667 { 668 PMCDBG(CPU,BND,2, "restore-cpu curcpu=%d restore=%d", 669 curthread->td_oncpu, pb->pb_cpu); 670 thread_lock(curthread); 671 if (pb->pb_bound) 672 sched_bind(curthread, pb->pb_cpu); 673 else 674 sched_unbind(curthread); 675 thread_unlock(curthread); 676 PMCDBG(CPU,BND,2, "%s", "restore-cpu done"); 677 } 678 679 /* 680 * move execution over the specified cpu and bind it there. 681 */ 682 683 static void 684 pmc_select_cpu(int cpu) 685 { 686 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 687 ("[pmc,%d] bad cpu number %d", __LINE__, cpu)); 688 689 /* Never move to an inactive CPU. */ 690 KASSERT(pmc_cpu_is_active(cpu), ("[pmc,%d] selecting inactive " 691 "CPU %d", __LINE__, cpu)); 692 693 PMCDBG(CPU,SEL,2, "select-cpu cpu=%d", cpu); 694 thread_lock(curthread); 695 sched_bind(curthread, cpu); 696 thread_unlock(curthread); 697 698 KASSERT(curthread->td_oncpu == cpu, 699 ("[pmc,%d] CPU not bound [cpu=%d, curr=%d]", __LINE__, 700 cpu, curthread->td_oncpu)); 701 702 PMCDBG(CPU,SEL,2, "select-cpu cpu=%d ok", cpu); 703 } 704 705 /* 706 * Force a context switch. 707 * 708 * We do this by pause'ing for 1 tick -- invoking mi_switch() is not 709 * guaranteed to force a context switch. 710 */ 711 712 static void 713 pmc_force_context_switch(void) 714 { 715 716 pause("pmcctx", 1); 717 } 718 719 /* 720 * Get the file name for an executable. This is a simple wrapper 721 * around vn_fullpath(9). 722 */ 723 724 static void 725 pmc_getfilename(struct vnode *v, char **fullpath, char **freepath) 726 { 727 728 *fullpath = "unknown"; 729 *freepath = NULL; 730 vn_fullpath(curthread, v, fullpath, freepath); 731 } 732 733 /* 734 * remove an process owning PMCs 735 */ 736 737 void 738 pmc_remove_owner(struct pmc_owner *po) 739 { 740 struct pmc *pm, *tmp; 741 742 sx_assert(&pmc_sx, SX_XLOCKED); 743 744 PMCDBG(OWN,ORM,1, "remove-owner po=%p", po); 745 746 /* Remove descriptor from the owner hash table */ 747 LIST_REMOVE(po, po_next); 748 749 /* release all owned PMC descriptors */ 750 LIST_FOREACH_SAFE(pm, &po->po_pmcs, pm_next, tmp) { 751 PMCDBG(OWN,ORM,2, "pmc=%p", pm); 752 KASSERT(pm->pm_owner == po, 753 ("[pmc,%d] owner %p != po %p", __LINE__, pm->pm_owner, po)); 754 755 pmc_release_pmc_descriptor(pm); /* will unlink from the list */ 756 } 757 758 KASSERT(po->po_sscount == 0, 759 ("[pmc,%d] SS count not zero", __LINE__)); 760 KASSERT(LIST_EMPTY(&po->po_pmcs), 761 ("[pmc,%d] PMC list not empty", __LINE__)); 762 763 /* de-configure the log file if present */ 764 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 765 pmclog_deconfigure_log(po); 766 } 767 768 /* 769 * remove an owner process record if all conditions are met. 770 */ 771 772 static void 773 pmc_maybe_remove_owner(struct pmc_owner *po) 774 { 775 776 PMCDBG(OWN,OMR,1, "maybe-remove-owner po=%p", po); 777 778 /* 779 * Remove owner record if 780 * - this process does not own any PMCs 781 * - this process has not allocated a system-wide sampling buffer 782 */ 783 784 if (LIST_EMPTY(&po->po_pmcs) && 785 ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0)) { 786 pmc_remove_owner(po); 787 pmc_destroy_owner_descriptor(po); 788 } 789 } 790 791 /* 792 * Add an association between a target process and a PMC. 793 */ 794 795 static void 796 pmc_link_target_process(struct pmc *pm, struct pmc_process *pp) 797 { 798 int ri; 799 struct pmc_target *pt; 800 801 sx_assert(&pmc_sx, SX_XLOCKED); 802 803 KASSERT(pm != NULL && pp != NULL, 804 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 805 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 806 ("[pmc,%d] Attaching a non-process-virtual pmc=%p to pid=%d", 807 __LINE__, pm, pp->pp_proc->p_pid)); 808 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= ((int) md->pmd_npmc - 1), 809 ("[pmc,%d] Illegal reference count %d for process record %p", 810 __LINE__, pp->pp_refcnt, (void *) pp)); 811 812 ri = PMC_TO_ROWINDEX(pm); 813 814 PMCDBG(PRC,TLK,1, "link-target pmc=%p ri=%d pmc-process=%p", 815 pm, ri, pp); 816 817 #ifdef DEBUG 818 LIST_FOREACH(pt, &pm->pm_targets, pt_next) 819 if (pt->pt_process == pp) 820 KASSERT(0, ("[pmc,%d] pp %p already in pmc %p targets", 821 __LINE__, pp, pm)); 822 #endif 823 824 pt = malloc(sizeof(struct pmc_target), M_PMC, M_WAITOK|M_ZERO); 825 pt->pt_process = pp; 826 827 LIST_INSERT_HEAD(&pm->pm_targets, pt, pt_next); 828 829 atomic_store_rel_ptr((uintptr_t *)&pp->pp_pmcs[ri].pp_pmc, 830 (uintptr_t)pm); 831 832 if (pm->pm_owner->po_owner == pp->pp_proc) 833 pm->pm_flags |= PMC_F_ATTACHED_TO_OWNER; 834 835 /* 836 * Initialize the per-process values at this row index. 837 */ 838 pp->pp_pmcs[ri].pp_pmcval = PMC_TO_MODE(pm) == PMC_MODE_TS ? 839 pm->pm_sc.pm_reloadcount : 0; 840 841 pp->pp_refcnt++; 842 843 } 844 845 /* 846 * Removes the association between a target process and a PMC. 847 */ 848 849 static void 850 pmc_unlink_target_process(struct pmc *pm, struct pmc_process *pp) 851 { 852 int ri; 853 struct proc *p; 854 struct pmc_target *ptgt; 855 856 sx_assert(&pmc_sx, SX_XLOCKED); 857 858 KASSERT(pm != NULL && pp != NULL, 859 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 860 861 KASSERT(pp->pp_refcnt >= 1 && pp->pp_refcnt <= (int) md->pmd_npmc, 862 ("[pmc,%d] Illegal ref count %d on process record %p", 863 __LINE__, pp->pp_refcnt, (void *) pp)); 864 865 ri = PMC_TO_ROWINDEX(pm); 866 867 PMCDBG(PRC,TUL,1, "unlink-target pmc=%p ri=%d pmc-process=%p", 868 pm, ri, pp); 869 870 KASSERT(pp->pp_pmcs[ri].pp_pmc == pm, 871 ("[pmc,%d] PMC ri %d mismatch pmc %p pp->[ri] %p", __LINE__, 872 ri, pm, pp->pp_pmcs[ri].pp_pmc)); 873 874 pp->pp_pmcs[ri].pp_pmc = NULL; 875 pp->pp_pmcs[ri].pp_pmcval = (pmc_value_t) 0; 876 877 /* Remove owner-specific flags */ 878 if (pm->pm_owner->po_owner == pp->pp_proc) { 879 pp->pp_flags &= ~PMC_PP_ENABLE_MSR_ACCESS; 880 pm->pm_flags &= ~PMC_F_ATTACHED_TO_OWNER; 881 } 882 883 pp->pp_refcnt--; 884 885 /* Remove the target process from the PMC structure */ 886 LIST_FOREACH(ptgt, &pm->pm_targets, pt_next) 887 if (ptgt->pt_process == pp) 888 break; 889 890 KASSERT(ptgt != NULL, ("[pmc,%d] process %p (pp: %p) not found " 891 "in pmc %p", __LINE__, pp->pp_proc, pp, pm)); 892 893 LIST_REMOVE(ptgt, pt_next); 894 free(ptgt, M_PMC); 895 896 /* if the PMC now lacks targets, send the owner a SIGIO */ 897 if (LIST_EMPTY(&pm->pm_targets)) { 898 p = pm->pm_owner->po_owner; 899 PROC_LOCK(p); 900 kern_psignal(p, SIGIO); 901 PROC_UNLOCK(p); 902 903 PMCDBG(PRC,SIG,2, "signalling proc=%p signal=%d", p, 904 SIGIO); 905 } 906 } 907 908 /* 909 * Check if PMC 'pm' may be attached to target process 't'. 910 */ 911 912 static int 913 pmc_can_attach(struct pmc *pm, struct proc *t) 914 { 915 struct proc *o; /* pmc owner */ 916 struct ucred *oc, *tc; /* owner, target credentials */ 917 int decline_attach, i; 918 919 /* 920 * A PMC's owner can always attach that PMC to itself. 921 */ 922 923 if ((o = pm->pm_owner->po_owner) == t) 924 return 0; 925 926 PROC_LOCK(o); 927 oc = o->p_ucred; 928 crhold(oc); 929 PROC_UNLOCK(o); 930 931 PROC_LOCK(t); 932 tc = t->p_ucred; 933 crhold(tc); 934 PROC_UNLOCK(t); 935 936 /* 937 * The effective uid of the PMC owner should match at least one 938 * of the {effective,real,saved} uids of the target process. 939 */ 940 941 decline_attach = oc->cr_uid != tc->cr_uid && 942 oc->cr_uid != tc->cr_svuid && 943 oc->cr_uid != tc->cr_ruid; 944 945 /* 946 * Every one of the target's group ids, must be in the owner's 947 * group list. 948 */ 949 for (i = 0; !decline_attach && i < tc->cr_ngroups; i++) 950 decline_attach = !groupmember(tc->cr_groups[i], oc); 951 952 /* check the read and saved gids too */ 953 if (decline_attach == 0) 954 decline_attach = !groupmember(tc->cr_rgid, oc) || 955 !groupmember(tc->cr_svgid, oc); 956 957 crfree(tc); 958 crfree(oc); 959 960 return !decline_attach; 961 } 962 963 /* 964 * Attach a process to a PMC. 965 */ 966 967 static int 968 pmc_attach_one_process(struct proc *p, struct pmc *pm) 969 { 970 int ri; 971 char *fullpath, *freepath; 972 struct pmc_process *pp; 973 974 sx_assert(&pmc_sx, SX_XLOCKED); 975 976 PMCDBG(PRC,ATT,2, "attach-one pm=%p ri=%d proc=%p (%d, %s)", pm, 977 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 978 979 /* 980 * Locate the process descriptor corresponding to process 'p', 981 * allocating space as needed. 982 * 983 * Verify that rowindex 'pm_rowindex' is free in the process 984 * descriptor. 985 * 986 * If not, allocate space for a descriptor and link the 987 * process descriptor and PMC. 988 */ 989 ri = PMC_TO_ROWINDEX(pm); 990 991 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_ALLOCATE)) == NULL) 992 return ENOMEM; 993 994 if (pp->pp_pmcs[ri].pp_pmc == pm) /* already present at slot [ri] */ 995 return EEXIST; 996 997 if (pp->pp_pmcs[ri].pp_pmc != NULL) 998 return EBUSY; 999 1000 pmc_link_target_process(pm, pp); 1001 1002 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) && 1003 (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) == 0) 1004 pm->pm_flags |= PMC_F_NEEDS_LOGFILE; 1005 1006 pm->pm_flags |= PMC_F_ATTACH_DONE; /* mark as attached */ 1007 1008 /* issue an attach event to a configured log file */ 1009 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) { 1010 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 1011 if (p->p_flag & P_KTHREAD) { 1012 fullpath = kernelname; 1013 freepath = NULL; 1014 } else 1015 pmclog_process_pmcattach(pm, p->p_pid, fullpath); 1016 if (freepath) 1017 free(freepath, M_TEMP); 1018 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1019 pmc_log_process_mappings(pm->pm_owner, p); 1020 } 1021 /* mark process as using HWPMCs */ 1022 PROC_LOCK(p); 1023 p->p_flag |= P_HWPMC; 1024 PROC_UNLOCK(p); 1025 1026 return 0; 1027 } 1028 1029 /* 1030 * Attach a process and optionally its children 1031 */ 1032 1033 static int 1034 pmc_attach_process(struct proc *p, struct pmc *pm) 1035 { 1036 int error; 1037 struct proc *top; 1038 1039 sx_assert(&pmc_sx, SX_XLOCKED); 1040 1041 PMCDBG(PRC,ATT,1, "attach pm=%p ri=%d proc=%p (%d, %s)", pm, 1042 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1043 1044 1045 /* 1046 * If this PMC successfully allowed a GETMSR operation 1047 * in the past, disallow further ATTACHes. 1048 */ 1049 1050 if ((pm->pm_flags & PMC_PP_ENABLE_MSR_ACCESS) != 0) 1051 return EPERM; 1052 1053 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 1054 return pmc_attach_one_process(p, pm); 1055 1056 /* 1057 * Traverse all child processes, attaching them to 1058 * this PMC. 1059 */ 1060 1061 sx_slock(&proctree_lock); 1062 1063 top = p; 1064 1065 for (;;) { 1066 if ((error = pmc_attach_one_process(p, pm)) != 0) 1067 break; 1068 if (!LIST_EMPTY(&p->p_children)) 1069 p = LIST_FIRST(&p->p_children); 1070 else for (;;) { 1071 if (p == top) 1072 goto done; 1073 if (LIST_NEXT(p, p_sibling)) { 1074 p = LIST_NEXT(p, p_sibling); 1075 break; 1076 } 1077 p = p->p_pptr; 1078 } 1079 } 1080 1081 if (error) 1082 (void) pmc_detach_process(top, pm); 1083 1084 done: 1085 sx_sunlock(&proctree_lock); 1086 return error; 1087 } 1088 1089 /* 1090 * Detach a process from a PMC. If there are no other PMCs tracking 1091 * this process, remove the process structure from its hash table. If 1092 * 'flags' contains PMC_FLAG_REMOVE, then free the process structure. 1093 */ 1094 1095 static int 1096 pmc_detach_one_process(struct proc *p, struct pmc *pm, int flags) 1097 { 1098 int ri; 1099 struct pmc_process *pp; 1100 1101 sx_assert(&pmc_sx, SX_XLOCKED); 1102 1103 KASSERT(pm != NULL, 1104 ("[pmc,%d] null pm pointer", __LINE__)); 1105 1106 ri = PMC_TO_ROWINDEX(pm); 1107 1108 PMCDBG(PRC,ATT,2, "detach-one pm=%p ri=%d proc=%p (%d, %s) flags=0x%x", 1109 pm, ri, p, p->p_pid, p->p_comm, flags); 1110 1111 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) 1112 return ESRCH; 1113 1114 if (pp->pp_pmcs[ri].pp_pmc != pm) 1115 return EINVAL; 1116 1117 pmc_unlink_target_process(pm, pp); 1118 1119 /* Issue a detach entry if a log file is configured */ 1120 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) 1121 pmclog_process_pmcdetach(pm, p->p_pid); 1122 1123 /* 1124 * If there are no PMCs targetting this process, we remove its 1125 * descriptor from the target hash table and unset the P_HWPMC 1126 * flag in the struct proc. 1127 */ 1128 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= (int) md->pmd_npmc, 1129 ("[pmc,%d] Illegal refcnt %d for process struct %p", 1130 __LINE__, pp->pp_refcnt, pp)); 1131 1132 if (pp->pp_refcnt != 0) /* still a target of some PMC */ 1133 return 0; 1134 1135 pmc_remove_process_descriptor(pp); 1136 1137 if (flags & PMC_FLAG_REMOVE) 1138 free(pp, M_PMC); 1139 1140 PROC_LOCK(p); 1141 p->p_flag &= ~P_HWPMC; 1142 PROC_UNLOCK(p); 1143 1144 return 0; 1145 } 1146 1147 /* 1148 * Detach a process and optionally its descendants from a PMC. 1149 */ 1150 1151 static int 1152 pmc_detach_process(struct proc *p, struct pmc *pm) 1153 { 1154 struct proc *top; 1155 1156 sx_assert(&pmc_sx, SX_XLOCKED); 1157 1158 PMCDBG(PRC,ATT,1, "detach pm=%p ri=%d proc=%p (%d, %s)", pm, 1159 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1160 1161 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 1162 return pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); 1163 1164 /* 1165 * Traverse all children, detaching them from this PMC. We 1166 * ignore errors since we could be detaching a PMC from a 1167 * partially attached proc tree. 1168 */ 1169 1170 sx_slock(&proctree_lock); 1171 1172 top = p; 1173 1174 for (;;) { 1175 (void) pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); 1176 1177 if (!LIST_EMPTY(&p->p_children)) 1178 p = LIST_FIRST(&p->p_children); 1179 else for (;;) { 1180 if (p == top) 1181 goto done; 1182 if (LIST_NEXT(p, p_sibling)) { 1183 p = LIST_NEXT(p, p_sibling); 1184 break; 1185 } 1186 p = p->p_pptr; 1187 } 1188 } 1189 1190 done: 1191 sx_sunlock(&proctree_lock); 1192 1193 if (LIST_EMPTY(&pm->pm_targets)) 1194 pm->pm_flags &= ~PMC_F_ATTACH_DONE; 1195 1196 return 0; 1197 } 1198 1199 1200 /* 1201 * Thread context switch IN 1202 */ 1203 1204 static void 1205 pmc_process_csw_in(struct thread *td) 1206 { 1207 int cpu; 1208 unsigned int adjri, ri; 1209 struct pmc *pm; 1210 struct proc *p; 1211 struct pmc_cpu *pc; 1212 struct pmc_hw *phw; 1213 pmc_value_t newvalue; 1214 struct pmc_process *pp; 1215 struct pmc_classdep *pcd; 1216 1217 p = td->td_proc; 1218 1219 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE)) == NULL) 1220 return; 1221 1222 KASSERT(pp->pp_proc == td->td_proc, 1223 ("[pmc,%d] not my thread state", __LINE__)); 1224 1225 critical_enter(); /* no preemption from this point */ 1226 1227 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1228 1229 PMCDBG(CSW,SWI,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1230 p->p_pid, p->p_comm, pp); 1231 1232 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 1233 ("[pmc,%d] wierd CPU id %d", __LINE__, cpu)); 1234 1235 pc = pmc_pcpu[cpu]; 1236 1237 for (ri = 0; ri < md->pmd_npmc; ri++) { 1238 1239 if ((pm = pp->pp_pmcs[ri].pp_pmc) == NULL) 1240 continue; 1241 1242 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 1243 ("[pmc,%d] Target PMC in non-virtual mode (%d)", 1244 __LINE__, PMC_TO_MODE(pm))); 1245 1246 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1247 ("[pmc,%d] Row index mismatch pmc %d != ri %d", 1248 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1249 1250 /* 1251 * Only PMCs that are marked as 'RUNNING' need 1252 * be placed on hardware. 1253 */ 1254 1255 if (pm->pm_state != PMC_STATE_RUNNING) 1256 continue; 1257 1258 /* increment PMC runcount */ 1259 atomic_add_rel_int(&pm->pm_runcount, 1); 1260 1261 /* configure the HWPMC we are going to use. */ 1262 pcd = pmc_ri_to_classdep(md, ri, &adjri); 1263 pcd->pcd_config_pmc(cpu, adjri, pm); 1264 1265 phw = pc->pc_hwpmcs[ri]; 1266 1267 KASSERT(phw != NULL, 1268 ("[pmc,%d] null hw pointer", __LINE__)); 1269 1270 KASSERT(phw->phw_pmc == pm, 1271 ("[pmc,%d] hw->pmc %p != pmc %p", __LINE__, 1272 phw->phw_pmc, pm)); 1273 1274 /* 1275 * Write out saved value and start the PMC. 1276 * 1277 * Sampling PMCs use a per-process value, while 1278 * counting mode PMCs use a per-pmc value that is 1279 * inherited across descendants. 1280 */ 1281 if (PMC_TO_MODE(pm) == PMC_MODE_TS) { 1282 mtx_pool_lock_spin(pmc_mtxpool, pm); 1283 newvalue = PMC_PCPU_SAVED(cpu,ri) = 1284 pp->pp_pmcs[ri].pp_pmcval; 1285 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1286 } else { 1287 KASSERT(PMC_TO_MODE(pm) == PMC_MODE_TC, 1288 ("[pmc,%d] illegal mode=%d", __LINE__, 1289 PMC_TO_MODE(pm))); 1290 mtx_pool_lock_spin(pmc_mtxpool, pm); 1291 newvalue = PMC_PCPU_SAVED(cpu, ri) = 1292 pm->pm_gv.pm_savedvalue; 1293 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1294 } 1295 1296 PMCDBG(CSW,SWI,1,"cpu=%d ri=%d new=%jd", cpu, ri, newvalue); 1297 1298 pcd->pcd_write_pmc(cpu, adjri, newvalue); 1299 pcd->pcd_start_pmc(cpu, adjri); 1300 } 1301 1302 /* 1303 * perform any other architecture/cpu dependent thread 1304 * switch-in actions. 1305 */ 1306 1307 (void) (*md->pmd_switch_in)(pc, pp); 1308 1309 critical_exit(); 1310 1311 } 1312 1313 /* 1314 * Thread context switch OUT. 1315 */ 1316 1317 static void 1318 pmc_process_csw_out(struct thread *td) 1319 { 1320 int cpu; 1321 int64_t tmp; 1322 struct pmc *pm; 1323 struct proc *p; 1324 enum pmc_mode mode; 1325 struct pmc_cpu *pc; 1326 pmc_value_t newvalue; 1327 unsigned int adjri, ri; 1328 struct pmc_process *pp; 1329 struct pmc_classdep *pcd; 1330 1331 1332 /* 1333 * Locate our process descriptor; this may be NULL if 1334 * this process is exiting and we have already removed 1335 * the process from the target process table. 1336 * 1337 * Note that due to kernel preemption, multiple 1338 * context switches may happen while the process is 1339 * exiting. 1340 * 1341 * Note also that if the target process cannot be 1342 * found we still need to deconfigure any PMCs that 1343 * are currently running on hardware. 1344 */ 1345 1346 p = td->td_proc; 1347 pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE); 1348 1349 /* 1350 * save PMCs 1351 */ 1352 1353 critical_enter(); 1354 1355 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1356 1357 PMCDBG(CSW,SWO,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1358 p->p_pid, p->p_comm, pp); 1359 1360 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 1361 ("[pmc,%d wierd CPU id %d", __LINE__, cpu)); 1362 1363 pc = pmc_pcpu[cpu]; 1364 1365 /* 1366 * When a PMC gets unlinked from a target PMC, it will 1367 * be removed from the target's pp_pmc[] array. 1368 * 1369 * However, on a MP system, the target could have been 1370 * executing on another CPU at the time of the unlink. 1371 * So, at context switch OUT time, we need to look at 1372 * the hardware to determine if a PMC is scheduled on 1373 * it. 1374 */ 1375 1376 for (ri = 0; ri < md->pmd_npmc; ri++) { 1377 1378 pcd = pmc_ri_to_classdep(md, ri, &adjri); 1379 pm = NULL; 1380 (void) (*pcd->pcd_get_config)(cpu, adjri, &pm); 1381 1382 if (pm == NULL) /* nothing at this row index */ 1383 continue; 1384 1385 mode = PMC_TO_MODE(pm); 1386 if (!PMC_IS_VIRTUAL_MODE(mode)) 1387 continue; /* not a process virtual PMC */ 1388 1389 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1390 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 1391 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1392 1393 /* Stop hardware if not already stopped */ 1394 if (pm->pm_stalled == 0) 1395 pcd->pcd_stop_pmc(cpu, adjri); 1396 1397 /* reduce this PMC's runcount */ 1398 atomic_subtract_rel_int(&pm->pm_runcount, 1); 1399 1400 /* 1401 * If this PMC is associated with this process, 1402 * save the reading. 1403 */ 1404 1405 if (pp != NULL && pp->pp_pmcs[ri].pp_pmc != NULL) { 1406 1407 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 1408 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", __LINE__, 1409 pm, ri, pp->pp_pmcs[ri].pp_pmc)); 1410 1411 KASSERT(pp->pp_refcnt > 0, 1412 ("[pmc,%d] pp refcnt = %d", __LINE__, 1413 pp->pp_refcnt)); 1414 1415 pcd->pcd_read_pmc(cpu, adjri, &newvalue); 1416 1417 tmp = newvalue - PMC_PCPU_SAVED(cpu,ri); 1418 1419 PMCDBG(CSW,SWO,1,"cpu=%d ri=%d tmp=%jd", cpu, ri, 1420 tmp); 1421 1422 if (mode == PMC_MODE_TS) { 1423 1424 /* 1425 * For sampling process-virtual PMCs, 1426 * we expect the count to be 1427 * decreasing as the 'value' 1428 * programmed into the PMC is the 1429 * number of events to be seen till 1430 * the next sampling interrupt. 1431 */ 1432 if (tmp < 0) 1433 tmp += pm->pm_sc.pm_reloadcount; 1434 mtx_pool_lock_spin(pmc_mtxpool, pm); 1435 pp->pp_pmcs[ri].pp_pmcval -= tmp; 1436 if ((int64_t) pp->pp_pmcs[ri].pp_pmcval < 0) 1437 pp->pp_pmcs[ri].pp_pmcval += 1438 pm->pm_sc.pm_reloadcount; 1439 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1440 1441 } else { 1442 1443 /* 1444 * For counting process-virtual PMCs, 1445 * we expect the count to be 1446 * increasing monotonically, modulo a 64 1447 * bit wraparound. 1448 */ 1449 KASSERT((int64_t) tmp >= 0, 1450 ("[pmc,%d] negative increment cpu=%d " 1451 "ri=%d newvalue=%jx saved=%jx " 1452 "incr=%jx", __LINE__, cpu, ri, 1453 newvalue, PMC_PCPU_SAVED(cpu,ri), tmp)); 1454 1455 mtx_pool_lock_spin(pmc_mtxpool, pm); 1456 pm->pm_gv.pm_savedvalue += tmp; 1457 pp->pp_pmcs[ri].pp_pmcval += tmp; 1458 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1459 1460 if (pm->pm_flags & PMC_F_LOG_PROCCSW) 1461 pmclog_process_proccsw(pm, pp, tmp); 1462 } 1463 } 1464 1465 /* mark hardware as free */ 1466 pcd->pcd_config_pmc(cpu, adjri, NULL); 1467 } 1468 1469 /* 1470 * perform any other architecture/cpu dependent thread 1471 * switch out functions. 1472 */ 1473 1474 (void) (*md->pmd_switch_out)(pc, pp); 1475 1476 critical_exit(); 1477 } 1478 1479 /* 1480 * A mapping change for a process. 1481 */ 1482 1483 static void 1484 pmc_process_mmap(struct thread *td, struct pmckern_map_in *pkm) 1485 { 1486 int ri; 1487 pid_t pid; 1488 char *fullpath, *freepath; 1489 const struct pmc *pm; 1490 struct pmc_owner *po; 1491 const struct pmc_process *pp; 1492 1493 freepath = fullpath = NULL; 1494 pmc_getfilename((struct vnode *) pkm->pm_file, &fullpath, &freepath); 1495 1496 pid = td->td_proc->p_pid; 1497 1498 /* Inform owners of all system-wide sampling PMCs. */ 1499 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1500 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1501 pmclog_process_map_in(po, pid, pkm->pm_address, fullpath); 1502 1503 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1504 goto done; 1505 1506 /* 1507 * Inform sampling PMC owners tracking this process. 1508 */ 1509 for (ri = 0; ri < md->pmd_npmc; ri++) 1510 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1511 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1512 pmclog_process_map_in(pm->pm_owner, 1513 pid, pkm->pm_address, fullpath); 1514 1515 done: 1516 if (freepath) 1517 free(freepath, M_TEMP); 1518 } 1519 1520 1521 /* 1522 * Log an munmap request. 1523 */ 1524 1525 static void 1526 pmc_process_munmap(struct thread *td, struct pmckern_map_out *pkm) 1527 { 1528 int ri; 1529 pid_t pid; 1530 struct pmc_owner *po; 1531 const struct pmc *pm; 1532 const struct pmc_process *pp; 1533 1534 pid = td->td_proc->p_pid; 1535 1536 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1537 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1538 pmclog_process_map_out(po, pid, pkm->pm_address, 1539 pkm->pm_address + pkm->pm_size); 1540 1541 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1542 return; 1543 1544 for (ri = 0; ri < md->pmd_npmc; ri++) 1545 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1546 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1547 pmclog_process_map_out(pm->pm_owner, pid, 1548 pkm->pm_address, pkm->pm_address + pkm->pm_size); 1549 } 1550 1551 /* 1552 * Log mapping information about the kernel. 1553 */ 1554 1555 static void 1556 pmc_log_kernel_mappings(struct pmc *pm) 1557 { 1558 struct pmc_owner *po; 1559 struct pmckern_map_in *km, *kmbase; 1560 1561 sx_assert(&pmc_sx, SX_LOCKED); 1562 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 1563 ("[pmc,%d] non-sampling PMC (%p) desires mapping information", 1564 __LINE__, (void *) pm)); 1565 1566 po = pm->pm_owner; 1567 1568 if (po->po_flags & PMC_PO_INITIAL_MAPPINGS_DONE) 1569 return; 1570 1571 /* 1572 * Log the current set of kernel modules. 1573 */ 1574 kmbase = linker_hwpmc_list_objects(); 1575 for (km = kmbase; km->pm_file != NULL; km++) { 1576 PMCDBG(LOG,REG,1,"%s %p", (char *) km->pm_file, 1577 (void *) km->pm_address); 1578 pmclog_process_map_in(po, (pid_t) -1, km->pm_address, 1579 km->pm_file); 1580 } 1581 free(kmbase, M_LINKER); 1582 1583 po->po_flags |= PMC_PO_INITIAL_MAPPINGS_DONE; 1584 } 1585 1586 /* 1587 * Log the mappings for a single process. 1588 */ 1589 1590 static void 1591 pmc_log_process_mappings(struct pmc_owner *po, struct proc *p) 1592 { 1593 vm_map_t map; 1594 struct vnode *vp; 1595 struct vmspace *vm; 1596 vm_map_entry_t entry; 1597 vm_offset_t last_end; 1598 u_int last_timestamp; 1599 struct vnode *last_vp; 1600 vm_offset_t start_addr; 1601 vm_object_t obj, lobj, tobj; 1602 char *fullpath, *freepath; 1603 1604 last_vp = NULL; 1605 last_end = (vm_offset_t) 0; 1606 fullpath = freepath = NULL; 1607 1608 if ((vm = vmspace_acquire_ref(p)) == NULL) 1609 return; 1610 1611 map = &vm->vm_map; 1612 vm_map_lock_read(map); 1613 1614 for (entry = map->header.next; entry != &map->header; entry = entry->next) { 1615 1616 if (entry == NULL) { 1617 PMCDBG(LOG,OPS,2, "hwpmc: vm_map entry unexpectedly " 1618 "NULL! pid=%d vm_map=%p\n", p->p_pid, map); 1619 break; 1620 } 1621 1622 /* 1623 * We only care about executable map entries. 1624 */ 1625 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) || 1626 !(entry->protection & VM_PROT_EXECUTE) || 1627 (entry->object.vm_object == NULL)) { 1628 continue; 1629 } 1630 1631 obj = entry->object.vm_object; 1632 VM_OBJECT_RLOCK(obj); 1633 1634 /* 1635 * Walk the backing_object list to find the base 1636 * (non-shadowed) vm_object. 1637 */ 1638 for (lobj = tobj = obj; tobj != NULL; tobj = tobj->backing_object) { 1639 if (tobj != obj) 1640 VM_OBJECT_RLOCK(tobj); 1641 if (lobj != obj) 1642 VM_OBJECT_RUNLOCK(lobj); 1643 lobj = tobj; 1644 } 1645 1646 /* 1647 * At this point lobj is the base vm_object and it is locked. 1648 */ 1649 if (lobj == NULL) { 1650 PMCDBG(LOG,OPS,2, "hwpmc: lobj unexpectedly NULL! pid=%d " 1651 "vm_map=%p vm_obj=%p\n", p->p_pid, map, obj); 1652 VM_OBJECT_RUNLOCK(obj); 1653 continue; 1654 } 1655 1656 if (lobj->type != OBJT_VNODE || lobj->handle == NULL) { 1657 if (lobj != obj) 1658 VM_OBJECT_RUNLOCK(lobj); 1659 VM_OBJECT_RUNLOCK(obj); 1660 continue; 1661 } 1662 1663 /* 1664 * Skip contiguous regions that point to the same 1665 * vnode, so we don't emit redundant MAP-IN 1666 * directives. 1667 */ 1668 if (entry->start == last_end && lobj->handle == last_vp) { 1669 last_end = entry->end; 1670 if (lobj != obj) 1671 VM_OBJECT_RUNLOCK(lobj); 1672 VM_OBJECT_RUNLOCK(obj); 1673 continue; 1674 } 1675 1676 /* 1677 * We don't want to keep the proc's vm_map or this 1678 * vm_object locked while we walk the pathname, since 1679 * vn_fullpath() can sleep. However, if we drop the 1680 * lock, it's possible for concurrent activity to 1681 * modify the vm_map list. To protect against this, 1682 * we save the vm_map timestamp before we release the 1683 * lock, and check it after we reacquire the lock 1684 * below. 1685 */ 1686 start_addr = entry->start; 1687 last_end = entry->end; 1688 last_timestamp = map->timestamp; 1689 vm_map_unlock_read(map); 1690 1691 vp = lobj->handle; 1692 vref(vp); 1693 if (lobj != obj) 1694 VM_OBJECT_RUNLOCK(lobj); 1695 1696 VM_OBJECT_RUNLOCK(obj); 1697 1698 freepath = NULL; 1699 pmc_getfilename(vp, &fullpath, &freepath); 1700 last_vp = vp; 1701 1702 vrele(vp); 1703 1704 vp = NULL; 1705 pmclog_process_map_in(po, p->p_pid, start_addr, fullpath); 1706 if (freepath) 1707 free(freepath, M_TEMP); 1708 1709 vm_map_lock_read(map); 1710 1711 /* 1712 * If our saved timestamp doesn't match, this means 1713 * that the vm_map was modified out from under us and 1714 * we can't trust our current "entry" pointer. Do a 1715 * new lookup for this entry. If there is no entry 1716 * for this address range, vm_map_lookup_entry() will 1717 * return the previous one, so we always want to go to 1718 * entry->next on the next loop iteration. 1719 * 1720 * There is an edge condition here that can occur if 1721 * there is no entry at or before this address. In 1722 * this situation, vm_map_lookup_entry returns 1723 * &map->header, which would cause our loop to abort 1724 * without processing the rest of the map. However, 1725 * in practice this will never happen for process 1726 * vm_map. This is because the executable's text 1727 * segment is the first mapping in the proc's address 1728 * space, and this mapping is never removed until the 1729 * process exits, so there will always be a non-header 1730 * entry at or before the requested address for 1731 * vm_map_lookup_entry to return. 1732 */ 1733 if (map->timestamp != last_timestamp) 1734 vm_map_lookup_entry(map, last_end - 1, &entry); 1735 } 1736 1737 vm_map_unlock_read(map); 1738 vmspace_free(vm); 1739 return; 1740 } 1741 1742 /* 1743 * Log mappings for all processes in the system. 1744 */ 1745 1746 static void 1747 pmc_log_all_process_mappings(struct pmc_owner *po) 1748 { 1749 struct proc *p, *top; 1750 1751 sx_assert(&pmc_sx, SX_XLOCKED); 1752 1753 if ((p = pfind(1)) == NULL) 1754 panic("[pmc,%d] Cannot find init", __LINE__); 1755 1756 PROC_UNLOCK(p); 1757 1758 sx_slock(&proctree_lock); 1759 1760 top = p; 1761 1762 for (;;) { 1763 pmc_log_process_mappings(po, p); 1764 if (!LIST_EMPTY(&p->p_children)) 1765 p = LIST_FIRST(&p->p_children); 1766 else for (;;) { 1767 if (p == top) 1768 goto done; 1769 if (LIST_NEXT(p, p_sibling)) { 1770 p = LIST_NEXT(p, p_sibling); 1771 break; 1772 } 1773 p = p->p_pptr; 1774 } 1775 } 1776 done: 1777 sx_sunlock(&proctree_lock); 1778 } 1779 1780 /* 1781 * The 'hook' invoked from the kernel proper 1782 */ 1783 1784 1785 #ifdef DEBUG 1786 const char *pmc_hooknames[] = { 1787 /* these strings correspond to PMC_FN_* in <sys/pmckern.h> */ 1788 "", 1789 "EXEC", 1790 "CSW-IN", 1791 "CSW-OUT", 1792 "SAMPLE", 1793 "UNUSED1", 1794 "UNUSED2", 1795 "MMAP", 1796 "MUNMAP", 1797 "CALLCHAIN-NMI", 1798 "CALLCHAIN-SOFT", 1799 "SOFTSAMPLING" 1800 }; 1801 #endif 1802 1803 static int 1804 pmc_hook_handler(struct thread *td, int function, void *arg) 1805 { 1806 1807 PMCDBG(MOD,PMH,1, "hook td=%p func=%d \"%s\" arg=%p", td, function, 1808 pmc_hooknames[function], arg); 1809 1810 switch (function) 1811 { 1812 1813 /* 1814 * Process exec() 1815 */ 1816 1817 case PMC_FN_PROCESS_EXEC: 1818 { 1819 char *fullpath, *freepath; 1820 unsigned int ri; 1821 int is_using_hwpmcs; 1822 struct pmc *pm; 1823 struct proc *p; 1824 struct pmc_owner *po; 1825 struct pmc_process *pp; 1826 struct pmckern_procexec *pk; 1827 1828 sx_assert(&pmc_sx, SX_XLOCKED); 1829 1830 p = td->td_proc; 1831 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 1832 1833 pk = (struct pmckern_procexec *) arg; 1834 1835 /* Inform owners of SS mode PMCs of the exec event. */ 1836 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1837 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1838 pmclog_process_procexec(po, PMC_ID_INVALID, 1839 p->p_pid, pk->pm_entryaddr, fullpath); 1840 1841 PROC_LOCK(p); 1842 is_using_hwpmcs = p->p_flag & P_HWPMC; 1843 PROC_UNLOCK(p); 1844 1845 if (!is_using_hwpmcs) { 1846 if (freepath) 1847 free(freepath, M_TEMP); 1848 break; 1849 } 1850 1851 /* 1852 * PMCs are not inherited across an exec(): remove any 1853 * PMCs that this process is the owner of. 1854 */ 1855 1856 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 1857 pmc_remove_owner(po); 1858 pmc_destroy_owner_descriptor(po); 1859 } 1860 1861 /* 1862 * If the process being exec'ed is not the target of any 1863 * PMC, we are done. 1864 */ 1865 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) { 1866 if (freepath) 1867 free(freepath, M_TEMP); 1868 break; 1869 } 1870 1871 /* 1872 * Log the exec event to all monitoring owners. Skip 1873 * owners who have already recieved the event because 1874 * they had system sampling PMCs active. 1875 */ 1876 for (ri = 0; ri < md->pmd_npmc; ri++) 1877 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 1878 po = pm->pm_owner; 1879 if (po->po_sscount == 0 && 1880 po->po_flags & PMC_PO_OWNS_LOGFILE) 1881 pmclog_process_procexec(po, pm->pm_id, 1882 p->p_pid, pk->pm_entryaddr, 1883 fullpath); 1884 } 1885 1886 if (freepath) 1887 free(freepath, M_TEMP); 1888 1889 1890 PMCDBG(PRC,EXC,1, "exec proc=%p (%d, %s) cred-changed=%d", 1891 p, p->p_pid, p->p_comm, pk->pm_credentialschanged); 1892 1893 if (pk->pm_credentialschanged == 0) /* no change */ 1894 break; 1895 1896 /* 1897 * If the newly exec()'ed process has a different credential 1898 * than before, allow it to be the target of a PMC only if 1899 * the PMC's owner has sufficient priviledge. 1900 */ 1901 1902 for (ri = 0; ri < md->pmd_npmc; ri++) 1903 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) 1904 if (pmc_can_attach(pm, td->td_proc) != 0) 1905 pmc_detach_one_process(td->td_proc, 1906 pm, PMC_FLAG_NONE); 1907 1908 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= (int) md->pmd_npmc, 1909 ("[pmc,%d] Illegal ref count %d on pp %p", __LINE__, 1910 pp->pp_refcnt, pp)); 1911 1912 /* 1913 * If this process is no longer the target of any 1914 * PMCs, we can remove the process entry and free 1915 * up space. 1916 */ 1917 1918 if (pp->pp_refcnt == 0) { 1919 pmc_remove_process_descriptor(pp); 1920 free(pp, M_PMC); 1921 break; 1922 } 1923 1924 } 1925 break; 1926 1927 case PMC_FN_CSW_IN: 1928 pmc_process_csw_in(td); 1929 break; 1930 1931 case PMC_FN_CSW_OUT: 1932 pmc_process_csw_out(td); 1933 break; 1934 1935 /* 1936 * Process accumulated PC samples. 1937 * 1938 * This function is expected to be called by hardclock() for 1939 * each CPU that has accumulated PC samples. 1940 * 1941 * This function is to be executed on the CPU whose samples 1942 * are being processed. 1943 */ 1944 case PMC_FN_DO_SAMPLES: 1945 1946 /* 1947 * Clear the cpu specific bit in the CPU mask before 1948 * do the rest of the processing. If the NMI handler 1949 * gets invoked after the "atomic_clear_int()" call 1950 * below but before "pmc_process_samples()" gets 1951 * around to processing the interrupt, then we will 1952 * come back here at the next hardclock() tick (and 1953 * may find nothing to do if "pmc_process_samples()" 1954 * had already processed the interrupt). We don't 1955 * lose the interrupt sample. 1956 */ 1957 CPU_CLR_ATOMIC(PCPU_GET(cpuid), &pmc_cpumask); 1958 pmc_process_samples(PCPU_GET(cpuid), PMC_HR); 1959 pmc_process_samples(PCPU_GET(cpuid), PMC_SR); 1960 break; 1961 1962 case PMC_FN_MMAP: 1963 sx_assert(&pmc_sx, SX_LOCKED); 1964 pmc_process_mmap(td, (struct pmckern_map_in *) arg); 1965 break; 1966 1967 case PMC_FN_MUNMAP: 1968 sx_assert(&pmc_sx, SX_LOCKED); 1969 pmc_process_munmap(td, (struct pmckern_map_out *) arg); 1970 break; 1971 1972 case PMC_FN_USER_CALLCHAIN: 1973 /* 1974 * Record a call chain. 1975 */ 1976 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 1977 __LINE__)); 1978 1979 pmc_capture_user_callchain(PCPU_GET(cpuid), PMC_HR, 1980 (struct trapframe *) arg); 1981 td->td_pflags &= ~TDP_CALLCHAIN; 1982 break; 1983 1984 case PMC_FN_USER_CALLCHAIN_SOFT: 1985 /* 1986 * Record a call chain. 1987 */ 1988 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 1989 __LINE__)); 1990 pmc_capture_user_callchain(PCPU_GET(cpuid), PMC_SR, 1991 (struct trapframe *) arg); 1992 td->td_pflags &= ~TDP_CALLCHAIN; 1993 break; 1994 1995 case PMC_FN_SOFT_SAMPLING: 1996 /* 1997 * Call soft PMC sampling intr. 1998 */ 1999 pmc_soft_intr((struct pmckern_soft *) arg); 2000 break; 2001 2002 default: 2003 #ifdef DEBUG 2004 KASSERT(0, ("[pmc,%d] unknown hook %d\n", __LINE__, function)); 2005 #endif 2006 break; 2007 2008 } 2009 2010 return 0; 2011 } 2012 2013 /* 2014 * allocate a 'struct pmc_owner' descriptor in the owner hash table. 2015 */ 2016 2017 static struct pmc_owner * 2018 pmc_allocate_owner_descriptor(struct proc *p) 2019 { 2020 uint32_t hindex; 2021 struct pmc_owner *po; 2022 struct pmc_ownerhash *poh; 2023 2024 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 2025 poh = &pmc_ownerhash[hindex]; 2026 2027 /* allocate space for N pointers and one descriptor struct */ 2028 po = malloc(sizeof(struct pmc_owner), M_PMC, M_WAITOK|M_ZERO); 2029 po->po_sscount = po->po_error = po->po_flags = po->po_logprocmaps = 0; 2030 po->po_file = NULL; 2031 po->po_owner = p; 2032 po->po_kthread = NULL; 2033 LIST_INIT(&po->po_pmcs); 2034 LIST_INSERT_HEAD(poh, po, po_next); /* insert into hash table */ 2035 2036 TAILQ_INIT(&po->po_logbuffers); 2037 mtx_init(&po->po_mtx, "pmc-owner-mtx", "pmc-per-proc", MTX_SPIN); 2038 2039 PMCDBG(OWN,ALL,1, "allocate-owner proc=%p (%d, %s) pmc-owner=%p", 2040 p, p->p_pid, p->p_comm, po); 2041 2042 return po; 2043 } 2044 2045 static void 2046 pmc_destroy_owner_descriptor(struct pmc_owner *po) 2047 { 2048 2049 PMCDBG(OWN,REL,1, "destroy-owner po=%p proc=%p (%d, %s)", 2050 po, po->po_owner, po->po_owner->p_pid, po->po_owner->p_comm); 2051 2052 mtx_destroy(&po->po_mtx); 2053 free(po, M_PMC); 2054 } 2055 2056 /* 2057 * find the descriptor corresponding to process 'p', adding or removing it 2058 * as specified by 'mode'. 2059 */ 2060 2061 static struct pmc_process * 2062 pmc_find_process_descriptor(struct proc *p, uint32_t mode) 2063 { 2064 uint32_t hindex; 2065 struct pmc_process *pp, *ppnew; 2066 struct pmc_processhash *pph; 2067 2068 hindex = PMC_HASH_PTR(p, pmc_processhashmask); 2069 pph = &pmc_processhash[hindex]; 2070 2071 ppnew = NULL; 2072 2073 /* 2074 * Pre-allocate memory in the FIND_ALLOCATE case since we 2075 * cannot call malloc(9) once we hold a spin lock. 2076 */ 2077 if (mode & PMC_FLAG_ALLOCATE) 2078 ppnew = malloc(sizeof(struct pmc_process) + md->pmd_npmc * 2079 sizeof(struct pmc_targetstate), M_PMC, M_WAITOK|M_ZERO); 2080 2081 mtx_lock_spin(&pmc_processhash_mtx); 2082 LIST_FOREACH(pp, pph, pp_next) 2083 if (pp->pp_proc == p) 2084 break; 2085 2086 if ((mode & PMC_FLAG_REMOVE) && pp != NULL) 2087 LIST_REMOVE(pp, pp_next); 2088 2089 if ((mode & PMC_FLAG_ALLOCATE) && pp == NULL && 2090 ppnew != NULL) { 2091 ppnew->pp_proc = p; 2092 LIST_INSERT_HEAD(pph, ppnew, pp_next); 2093 pp = ppnew; 2094 ppnew = NULL; 2095 } 2096 mtx_unlock_spin(&pmc_processhash_mtx); 2097 2098 if (pp != NULL && ppnew != NULL) 2099 free(ppnew, M_PMC); 2100 2101 return pp; 2102 } 2103 2104 /* 2105 * remove a process descriptor from the process hash table. 2106 */ 2107 2108 static void 2109 pmc_remove_process_descriptor(struct pmc_process *pp) 2110 { 2111 KASSERT(pp->pp_refcnt == 0, 2112 ("[pmc,%d] Removing process descriptor %p with count %d", 2113 __LINE__, pp, pp->pp_refcnt)); 2114 2115 mtx_lock_spin(&pmc_processhash_mtx); 2116 LIST_REMOVE(pp, pp_next); 2117 mtx_unlock_spin(&pmc_processhash_mtx); 2118 } 2119 2120 2121 /* 2122 * find an owner descriptor corresponding to proc 'p' 2123 */ 2124 2125 static struct pmc_owner * 2126 pmc_find_owner_descriptor(struct proc *p) 2127 { 2128 uint32_t hindex; 2129 struct pmc_owner *po; 2130 struct pmc_ownerhash *poh; 2131 2132 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 2133 poh = &pmc_ownerhash[hindex]; 2134 2135 po = NULL; 2136 LIST_FOREACH(po, poh, po_next) 2137 if (po->po_owner == p) 2138 break; 2139 2140 PMCDBG(OWN,FND,1, "find-owner proc=%p (%d, %s) hindex=0x%x -> " 2141 "pmc-owner=%p", p, p->p_pid, p->p_comm, hindex, po); 2142 2143 return po; 2144 } 2145 2146 /* 2147 * pmc_allocate_pmc_descriptor 2148 * 2149 * Allocate a pmc descriptor and initialize its 2150 * fields. 2151 */ 2152 2153 static struct pmc * 2154 pmc_allocate_pmc_descriptor(void) 2155 { 2156 struct pmc *pmc; 2157 2158 pmc = malloc(sizeof(struct pmc), M_PMC, M_WAITOK|M_ZERO); 2159 pmc->pm_owner = NULL; 2160 LIST_INIT(&pmc->pm_targets); 2161 2162 PMCDBG(PMC,ALL,1, "allocate-pmc -> pmc=%p", pmc); 2163 2164 return pmc; 2165 } 2166 2167 /* 2168 * Destroy a pmc descriptor. 2169 */ 2170 2171 static void 2172 pmc_destroy_pmc_descriptor(struct pmc *pm) 2173 { 2174 (void) pm; 2175 2176 #ifdef DEBUG 2177 KASSERT(pm->pm_state == PMC_STATE_DELETED || 2178 pm->pm_state == PMC_STATE_FREE, 2179 ("[pmc,%d] destroying non-deleted PMC", __LINE__)); 2180 KASSERT(LIST_EMPTY(&pm->pm_targets), 2181 ("[pmc,%d] destroying pmc with targets", __LINE__)); 2182 KASSERT(pm->pm_owner == NULL, 2183 ("[pmc,%d] destroying pmc attached to an owner", __LINE__)); 2184 KASSERT(pm->pm_runcount == 0, 2185 ("[pmc,%d] pmc has non-zero run count %d", __LINE__, 2186 pm->pm_runcount)); 2187 #endif 2188 } 2189 2190 static void 2191 pmc_wait_for_pmc_idle(struct pmc *pm) 2192 { 2193 #ifdef DEBUG 2194 volatile int maxloop; 2195 2196 maxloop = 100 * pmc_cpu_max(); 2197 #endif 2198 /* 2199 * Loop (with a forced context switch) till the PMC's runcount 2200 * comes down to zero. 2201 */ 2202 while (atomic_load_acq_32(&pm->pm_runcount) > 0) { 2203 #ifdef DEBUG 2204 maxloop--; 2205 KASSERT(maxloop > 0, 2206 ("[pmc,%d] (ri%d, rc%d) waiting too long for " 2207 "pmc to be free", __LINE__, 2208 PMC_TO_ROWINDEX(pm), pm->pm_runcount)); 2209 #endif 2210 pmc_force_context_switch(); 2211 } 2212 } 2213 2214 /* 2215 * This function does the following things: 2216 * 2217 * - detaches the PMC from hardware 2218 * - unlinks all target threads that were attached to it 2219 * - removes the PMC from its owner's list 2220 * - destroy's the PMC private mutex 2221 * 2222 * Once this function completes, the given pmc pointer can be safely 2223 * FREE'd by the caller. 2224 */ 2225 2226 static void 2227 pmc_release_pmc_descriptor(struct pmc *pm) 2228 { 2229 enum pmc_mode mode; 2230 struct pmc_hw *phw; 2231 u_int adjri, ri, cpu; 2232 struct pmc_owner *po; 2233 struct pmc_binding pb; 2234 struct pmc_process *pp; 2235 struct pmc_classdep *pcd; 2236 struct pmc_target *ptgt, *tmp; 2237 2238 sx_assert(&pmc_sx, SX_XLOCKED); 2239 2240 KASSERT(pm, ("[pmc,%d] null pmc", __LINE__)); 2241 2242 ri = PMC_TO_ROWINDEX(pm); 2243 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2244 mode = PMC_TO_MODE(pm); 2245 2246 PMCDBG(PMC,REL,1, "release-pmc pmc=%p ri=%d mode=%d", pm, ri, 2247 mode); 2248 2249 /* 2250 * First, we take the PMC off hardware. 2251 */ 2252 cpu = 0; 2253 if (PMC_IS_SYSTEM_MODE(mode)) { 2254 2255 /* 2256 * A system mode PMC runs on a specific CPU. Switch 2257 * to this CPU and turn hardware off. 2258 */ 2259 pmc_save_cpu_binding(&pb); 2260 2261 cpu = PMC_TO_CPU(pm); 2262 2263 pmc_select_cpu(cpu); 2264 2265 /* switch off non-stalled CPUs */ 2266 if (pm->pm_state == PMC_STATE_RUNNING && 2267 pm->pm_stalled == 0) { 2268 2269 phw = pmc_pcpu[cpu]->pc_hwpmcs[ri]; 2270 2271 KASSERT(phw->phw_pmc == pm, 2272 ("[pmc, %d] pmc ptr ri(%d) hw(%p) pm(%p)", 2273 __LINE__, ri, phw->phw_pmc, pm)); 2274 PMCDBG(PMC,REL,2, "stopping cpu=%d ri=%d", cpu, ri); 2275 2276 critical_enter(); 2277 pcd->pcd_stop_pmc(cpu, adjri); 2278 critical_exit(); 2279 } 2280 2281 PMCDBG(PMC,REL,2, "decfg cpu=%d ri=%d", cpu, ri); 2282 2283 critical_enter(); 2284 pcd->pcd_config_pmc(cpu, adjri, NULL); 2285 critical_exit(); 2286 2287 /* adjust the global and process count of SS mode PMCs */ 2288 if (mode == PMC_MODE_SS && pm->pm_state == PMC_STATE_RUNNING) { 2289 po = pm->pm_owner; 2290 po->po_sscount--; 2291 if (po->po_sscount == 0) { 2292 atomic_subtract_rel_int(&pmc_ss_count, 1); 2293 LIST_REMOVE(po, po_ssnext); 2294 } 2295 } 2296 2297 pm->pm_state = PMC_STATE_DELETED; 2298 2299 pmc_restore_cpu_binding(&pb); 2300 2301 /* 2302 * We could have references to this PMC structure in 2303 * the per-cpu sample queues. Wait for the queue to 2304 * drain. 2305 */ 2306 pmc_wait_for_pmc_idle(pm); 2307 2308 } else if (PMC_IS_VIRTUAL_MODE(mode)) { 2309 2310 /* 2311 * A virtual PMC could be running on multiple CPUs at 2312 * a given instant. 2313 * 2314 * By marking its state as DELETED, we ensure that 2315 * this PMC is never further scheduled on hardware. 2316 * 2317 * Then we wait till all CPUs are done with this PMC. 2318 */ 2319 pm->pm_state = PMC_STATE_DELETED; 2320 2321 2322 /* Wait for the PMCs runcount to come to zero. */ 2323 pmc_wait_for_pmc_idle(pm); 2324 2325 /* 2326 * At this point the PMC is off all CPUs and cannot be 2327 * freshly scheduled onto a CPU. It is now safe to 2328 * unlink all targets from this PMC. If a 2329 * process-record's refcount falls to zero, we remove 2330 * it from the hash table. The module-wide SX lock 2331 * protects us from races. 2332 */ 2333 LIST_FOREACH_SAFE(ptgt, &pm->pm_targets, pt_next, tmp) { 2334 pp = ptgt->pt_process; 2335 pmc_unlink_target_process(pm, pp); /* frees 'ptgt' */ 2336 2337 PMCDBG(PMC,REL,3, "pp->refcnt=%d", pp->pp_refcnt); 2338 2339 /* 2340 * If the target process record shows that no 2341 * PMCs are attached to it, reclaim its space. 2342 */ 2343 2344 if (pp->pp_refcnt == 0) { 2345 pmc_remove_process_descriptor(pp); 2346 free(pp, M_PMC); 2347 } 2348 } 2349 2350 cpu = curthread->td_oncpu; /* setup cpu for pmd_release() */ 2351 2352 } 2353 2354 /* 2355 * Release any MD resources 2356 */ 2357 (void) pcd->pcd_release_pmc(cpu, adjri, pm); 2358 2359 /* 2360 * Update row disposition 2361 */ 2362 2363 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) 2364 PMC_UNMARK_ROW_STANDALONE(ri); 2365 else 2366 PMC_UNMARK_ROW_THREAD(ri); 2367 2368 /* unlink from the owner's list */ 2369 if (pm->pm_owner) { 2370 LIST_REMOVE(pm, pm_next); 2371 pm->pm_owner = NULL; 2372 } 2373 2374 pmc_destroy_pmc_descriptor(pm); 2375 } 2376 2377 /* 2378 * Register an owner and a pmc. 2379 */ 2380 2381 static int 2382 pmc_register_owner(struct proc *p, struct pmc *pmc) 2383 { 2384 struct pmc_owner *po; 2385 2386 sx_assert(&pmc_sx, SX_XLOCKED); 2387 2388 if ((po = pmc_find_owner_descriptor(p)) == NULL) 2389 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) 2390 return ENOMEM; 2391 2392 KASSERT(pmc->pm_owner == NULL, 2393 ("[pmc,%d] attempting to own an initialized PMC", __LINE__)); 2394 pmc->pm_owner = po; 2395 2396 LIST_INSERT_HEAD(&po->po_pmcs, pmc, pm_next); 2397 2398 PROC_LOCK(p); 2399 p->p_flag |= P_HWPMC; 2400 PROC_UNLOCK(p); 2401 2402 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 2403 pmclog_process_pmcallocate(pmc); 2404 2405 PMCDBG(PMC,REG,1, "register-owner pmc-owner=%p pmc=%p", 2406 po, pmc); 2407 2408 return 0; 2409 } 2410 2411 /* 2412 * Return the current row disposition: 2413 * == 0 => FREE 2414 * > 0 => PROCESS MODE 2415 * < 0 => SYSTEM MODE 2416 */ 2417 2418 int 2419 pmc_getrowdisp(int ri) 2420 { 2421 return pmc_pmcdisp[ri]; 2422 } 2423 2424 /* 2425 * Check if a PMC at row index 'ri' can be allocated to the current 2426 * process. 2427 * 2428 * Allocation can fail if: 2429 * - the current process is already being profiled by a PMC at index 'ri', 2430 * attached to it via OP_PMCATTACH. 2431 * - the current process has already allocated a PMC at index 'ri' 2432 * via OP_ALLOCATE. 2433 */ 2434 2435 static int 2436 pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, int cpu) 2437 { 2438 enum pmc_mode mode; 2439 struct pmc *pm; 2440 struct pmc_owner *po; 2441 struct pmc_process *pp; 2442 2443 PMCDBG(PMC,ALR,1, "can-allocate-rowindex proc=%p (%d, %s) ri=%d " 2444 "cpu=%d", p, p->p_pid, p->p_comm, ri, cpu); 2445 2446 /* 2447 * We shouldn't have already allocated a process-mode PMC at 2448 * row index 'ri'. 2449 * 2450 * We shouldn't have allocated a system-wide PMC on the same 2451 * CPU and same RI. 2452 */ 2453 if ((po = pmc_find_owner_descriptor(p)) != NULL) 2454 LIST_FOREACH(pm, &po->po_pmcs, pm_next) { 2455 if (PMC_TO_ROWINDEX(pm) == ri) { 2456 mode = PMC_TO_MODE(pm); 2457 if (PMC_IS_VIRTUAL_MODE(mode)) 2458 return EEXIST; 2459 if (PMC_IS_SYSTEM_MODE(mode) && 2460 (int) PMC_TO_CPU(pm) == cpu) 2461 return EEXIST; 2462 } 2463 } 2464 2465 /* 2466 * We also shouldn't be the target of any PMC at this index 2467 * since otherwise a PMC_ATTACH to ourselves will fail. 2468 */ 2469 if ((pp = pmc_find_process_descriptor(p, 0)) != NULL) 2470 if (pp->pp_pmcs[ri].pp_pmc) 2471 return EEXIST; 2472 2473 PMCDBG(PMC,ALR,2, "can-allocate-rowindex proc=%p (%d, %s) ri=%d ok", 2474 p, p->p_pid, p->p_comm, ri); 2475 2476 return 0; 2477 } 2478 2479 /* 2480 * Check if a given PMC at row index 'ri' can be currently used in 2481 * mode 'mode'. 2482 */ 2483 2484 static int 2485 pmc_can_allocate_row(int ri, enum pmc_mode mode) 2486 { 2487 enum pmc_disp disp; 2488 2489 sx_assert(&pmc_sx, SX_XLOCKED); 2490 2491 PMCDBG(PMC,ALR,1, "can-allocate-row ri=%d mode=%d", ri, mode); 2492 2493 if (PMC_IS_SYSTEM_MODE(mode)) 2494 disp = PMC_DISP_STANDALONE; 2495 else 2496 disp = PMC_DISP_THREAD; 2497 2498 /* 2499 * check disposition for PMC row 'ri': 2500 * 2501 * Expected disposition Row-disposition Result 2502 * 2503 * STANDALONE STANDALONE or FREE proceed 2504 * STANDALONE THREAD fail 2505 * THREAD THREAD or FREE proceed 2506 * THREAD STANDALONE fail 2507 */ 2508 2509 if (!PMC_ROW_DISP_IS_FREE(ri) && 2510 !(disp == PMC_DISP_THREAD && PMC_ROW_DISP_IS_THREAD(ri)) && 2511 !(disp == PMC_DISP_STANDALONE && PMC_ROW_DISP_IS_STANDALONE(ri))) 2512 return EBUSY; 2513 2514 /* 2515 * All OK 2516 */ 2517 2518 PMCDBG(PMC,ALR,2, "can-allocate-row ri=%d mode=%d ok", ri, mode); 2519 2520 return 0; 2521 2522 } 2523 2524 /* 2525 * Find a PMC descriptor with user handle 'pmcid' for thread 'td'. 2526 */ 2527 2528 static struct pmc * 2529 pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, pmc_id_t pmcid) 2530 { 2531 struct pmc *pm; 2532 2533 KASSERT(PMC_ID_TO_ROWINDEX(pmcid) < md->pmd_npmc, 2534 ("[pmc,%d] Illegal pmc index %d (max %d)", __LINE__, 2535 PMC_ID_TO_ROWINDEX(pmcid), md->pmd_npmc)); 2536 2537 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 2538 if (pm->pm_id == pmcid) 2539 return pm; 2540 2541 return NULL; 2542 } 2543 2544 static int 2545 pmc_find_pmc(pmc_id_t pmcid, struct pmc **pmc) 2546 { 2547 2548 struct pmc *pm; 2549 struct pmc_owner *po; 2550 2551 PMCDBG(PMC,FND,1, "find-pmc id=%d", pmcid); 2552 2553 if ((po = pmc_find_owner_descriptor(curthread->td_proc)) == NULL) 2554 return ESRCH; 2555 2556 if ((pm = pmc_find_pmc_descriptor_in_process(po, pmcid)) == NULL) 2557 return EINVAL; 2558 2559 PMCDBG(PMC,FND,2, "find-pmc id=%d -> pmc=%p", pmcid, pm); 2560 2561 *pmc = pm; 2562 return 0; 2563 } 2564 2565 /* 2566 * Start a PMC. 2567 */ 2568 2569 static int 2570 pmc_start(struct pmc *pm) 2571 { 2572 enum pmc_mode mode; 2573 struct pmc_owner *po; 2574 struct pmc_binding pb; 2575 struct pmc_classdep *pcd; 2576 int adjri, error, cpu, ri; 2577 2578 KASSERT(pm != NULL, 2579 ("[pmc,%d] null pm", __LINE__)); 2580 2581 mode = PMC_TO_MODE(pm); 2582 ri = PMC_TO_ROWINDEX(pm); 2583 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2584 2585 error = 0; 2586 2587 PMCDBG(PMC,OPS,1, "start pmc=%p mode=%d ri=%d", pm, mode, ri); 2588 2589 po = pm->pm_owner; 2590 2591 /* 2592 * Disallow PMCSTART if a logfile is required but has not been 2593 * configured yet. 2594 */ 2595 if ((pm->pm_flags & PMC_F_NEEDS_LOGFILE) && 2596 (po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) 2597 return (EDOOFUS); /* programming error */ 2598 2599 /* 2600 * If this is a sampling mode PMC, log mapping information for 2601 * the kernel modules that are currently loaded. 2602 */ 2603 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 2604 pmc_log_kernel_mappings(pm); 2605 2606 if (PMC_IS_VIRTUAL_MODE(mode)) { 2607 2608 /* 2609 * If a PMCATTACH has never been done on this PMC, 2610 * attach it to its owner process. 2611 */ 2612 2613 if (LIST_EMPTY(&pm->pm_targets)) 2614 error = (pm->pm_flags & PMC_F_ATTACH_DONE) ? ESRCH : 2615 pmc_attach_process(po->po_owner, pm); 2616 2617 /* 2618 * If the PMC is attached to its owner, then force a context 2619 * switch to ensure that the MD state gets set correctly. 2620 */ 2621 2622 if (error == 0) { 2623 pm->pm_state = PMC_STATE_RUNNING; 2624 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) 2625 pmc_force_context_switch(); 2626 } 2627 2628 return (error); 2629 } 2630 2631 2632 /* 2633 * A system-wide PMC. 2634 * 2635 * Add the owner to the global list if this is a system-wide 2636 * sampling PMC. 2637 */ 2638 2639 if (mode == PMC_MODE_SS) { 2640 if (po->po_sscount == 0) { 2641 LIST_INSERT_HEAD(&pmc_ss_owners, po, po_ssnext); 2642 atomic_add_rel_int(&pmc_ss_count, 1); 2643 PMCDBG(PMC,OPS,1, "po=%p in global list", po); 2644 } 2645 po->po_sscount++; 2646 2647 /* 2648 * Log mapping information for all existing processes in the 2649 * system. Subsequent mappings are logged as they happen; 2650 * see pmc_process_mmap(). 2651 */ 2652 if (po->po_logprocmaps == 0) { 2653 pmc_log_all_process_mappings(po); 2654 po->po_logprocmaps = 1; 2655 } 2656 } 2657 2658 /* 2659 * Move to the CPU associated with this 2660 * PMC, and start the hardware. 2661 */ 2662 2663 pmc_save_cpu_binding(&pb); 2664 2665 cpu = PMC_TO_CPU(pm); 2666 2667 if (!pmc_cpu_is_active(cpu)) 2668 return (ENXIO); 2669 2670 pmc_select_cpu(cpu); 2671 2672 /* 2673 * global PMCs are configured at allocation time 2674 * so write out the initial value and start the PMC. 2675 */ 2676 2677 pm->pm_state = PMC_STATE_RUNNING; 2678 2679 critical_enter(); 2680 if ((error = pcd->pcd_write_pmc(cpu, adjri, 2681 PMC_IS_SAMPLING_MODE(mode) ? 2682 pm->pm_sc.pm_reloadcount : 2683 pm->pm_sc.pm_initial)) == 0) 2684 error = pcd->pcd_start_pmc(cpu, adjri); 2685 critical_exit(); 2686 2687 pmc_restore_cpu_binding(&pb); 2688 2689 return (error); 2690 } 2691 2692 /* 2693 * Stop a PMC. 2694 */ 2695 2696 static int 2697 pmc_stop(struct pmc *pm) 2698 { 2699 struct pmc_owner *po; 2700 struct pmc_binding pb; 2701 struct pmc_classdep *pcd; 2702 int adjri, cpu, error, ri; 2703 2704 KASSERT(pm != NULL, ("[pmc,%d] null pmc", __LINE__)); 2705 2706 PMCDBG(PMC,OPS,1, "stop pmc=%p mode=%d ri=%d", pm, 2707 PMC_TO_MODE(pm), PMC_TO_ROWINDEX(pm)); 2708 2709 pm->pm_state = PMC_STATE_STOPPED; 2710 2711 /* 2712 * If the PMC is a virtual mode one, changing the state to 2713 * non-RUNNING is enough to ensure that the PMC never gets 2714 * scheduled. 2715 * 2716 * If this PMC is current running on a CPU, then it will 2717 * handled correctly at the time its target process is context 2718 * switched out. 2719 */ 2720 2721 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 2722 return 0; 2723 2724 /* 2725 * A system-mode PMC. Move to the CPU associated with 2726 * this PMC, and stop the hardware. We update the 2727 * 'initial count' so that a subsequent PMCSTART will 2728 * resume counting from the current hardware count. 2729 */ 2730 2731 pmc_save_cpu_binding(&pb); 2732 2733 cpu = PMC_TO_CPU(pm); 2734 2735 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 2736 ("[pmc,%d] illegal cpu=%d", __LINE__, cpu)); 2737 2738 if (!pmc_cpu_is_active(cpu)) 2739 return ENXIO; 2740 2741 pmc_select_cpu(cpu); 2742 2743 ri = PMC_TO_ROWINDEX(pm); 2744 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2745 2746 critical_enter(); 2747 if ((error = pcd->pcd_stop_pmc(cpu, adjri)) == 0) 2748 error = pcd->pcd_read_pmc(cpu, adjri, &pm->pm_sc.pm_initial); 2749 critical_exit(); 2750 2751 pmc_restore_cpu_binding(&pb); 2752 2753 po = pm->pm_owner; 2754 2755 /* remove this owner from the global list of SS PMC owners */ 2756 if (PMC_TO_MODE(pm) == PMC_MODE_SS) { 2757 po->po_sscount--; 2758 if (po->po_sscount == 0) { 2759 atomic_subtract_rel_int(&pmc_ss_count, 1); 2760 LIST_REMOVE(po, po_ssnext); 2761 PMCDBG(PMC,OPS,2,"po=%p removed from global list", po); 2762 } 2763 } 2764 2765 return (error); 2766 } 2767 2768 2769 #ifdef DEBUG 2770 static const char *pmc_op_to_name[] = { 2771 #undef __PMC_OP 2772 #define __PMC_OP(N, D) #N , 2773 __PMC_OPS() 2774 NULL 2775 }; 2776 #endif 2777 2778 /* 2779 * The syscall interface 2780 */ 2781 2782 #define PMC_GET_SX_XLOCK(...) do { \ 2783 sx_xlock(&pmc_sx); \ 2784 if (pmc_hook == NULL) { \ 2785 sx_xunlock(&pmc_sx); \ 2786 return __VA_ARGS__; \ 2787 } \ 2788 } while (0) 2789 2790 #define PMC_DOWNGRADE_SX() do { \ 2791 sx_downgrade(&pmc_sx); \ 2792 is_sx_downgraded = 1; \ 2793 } while (0) 2794 2795 static int 2796 pmc_syscall_handler(struct thread *td, void *syscall_args) 2797 { 2798 int error, is_sx_downgraded, is_sx_locked, op; 2799 struct pmc_syscall_args *c; 2800 void *arg; 2801 2802 PMC_GET_SX_XLOCK(ENOSYS); 2803 2804 DROP_GIANT(); 2805 2806 is_sx_downgraded = 0; 2807 is_sx_locked = 1; 2808 2809 c = (struct pmc_syscall_args *) syscall_args; 2810 2811 op = c->pmop_code; 2812 arg = c->pmop_data; 2813 2814 PMCDBG(MOD,PMS,1, "syscall op=%d \"%s\" arg=%p", op, 2815 pmc_op_to_name[op], arg); 2816 2817 error = 0; 2818 atomic_add_int(&pmc_stats.pm_syscalls, 1); 2819 2820 switch(op) 2821 { 2822 2823 2824 /* 2825 * Configure a log file. 2826 * 2827 * XXX This OP will be reworked. 2828 */ 2829 2830 case PMC_OP_CONFIGURELOG: 2831 { 2832 struct proc *p; 2833 struct pmc *pm; 2834 struct pmc_owner *po; 2835 struct pmc_op_configurelog cl; 2836 2837 sx_assert(&pmc_sx, SX_XLOCKED); 2838 2839 if ((error = copyin(arg, &cl, sizeof(cl))) != 0) 2840 break; 2841 2842 /* mark this process as owning a log file */ 2843 p = td->td_proc; 2844 if ((po = pmc_find_owner_descriptor(p)) == NULL) 2845 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) { 2846 error = ENOMEM; 2847 break; 2848 } 2849 2850 /* 2851 * If a valid fd was passed in, try to configure that, 2852 * otherwise if 'fd' was less than zero and there was 2853 * a log file configured, flush its buffers and 2854 * de-configure it. 2855 */ 2856 if (cl.pm_logfd >= 0) { 2857 sx_xunlock(&pmc_sx); 2858 is_sx_locked = 0; 2859 error = pmclog_configure_log(md, po, cl.pm_logfd); 2860 } else if (po->po_flags & PMC_PO_OWNS_LOGFILE) { 2861 pmclog_process_closelog(po); 2862 error = pmclog_close(po); 2863 if (error == 0) { 2864 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 2865 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 2866 pm->pm_state == PMC_STATE_RUNNING) 2867 pmc_stop(pm); 2868 error = pmclog_deconfigure_log(po); 2869 } 2870 } else 2871 error = EINVAL; 2872 2873 if (error) 2874 break; 2875 } 2876 break; 2877 2878 /* 2879 * Flush a log file. 2880 */ 2881 2882 case PMC_OP_FLUSHLOG: 2883 { 2884 struct pmc_owner *po; 2885 2886 sx_assert(&pmc_sx, SX_XLOCKED); 2887 2888 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 2889 error = EINVAL; 2890 break; 2891 } 2892 2893 error = pmclog_flush(po); 2894 } 2895 break; 2896 2897 /* 2898 * Close a log file. 2899 */ 2900 2901 case PMC_OP_CLOSELOG: 2902 { 2903 struct pmc_owner *po; 2904 2905 sx_assert(&pmc_sx, SX_XLOCKED); 2906 2907 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 2908 error = EINVAL; 2909 break; 2910 } 2911 2912 error = pmclog_close(po); 2913 } 2914 break; 2915 2916 /* 2917 * Retrieve hardware configuration. 2918 */ 2919 2920 case PMC_OP_GETCPUINFO: /* CPU information */ 2921 { 2922 struct pmc_op_getcpuinfo gci; 2923 struct pmc_classinfo *pci; 2924 struct pmc_classdep *pcd; 2925 int cl; 2926 2927 gci.pm_cputype = md->pmd_cputype; 2928 gci.pm_ncpu = pmc_cpu_max(); 2929 gci.pm_npmc = md->pmd_npmc; 2930 gci.pm_nclass = md->pmd_nclass; 2931 pci = gci.pm_classes; 2932 pcd = md->pmd_classdep; 2933 for (cl = 0; cl < md->pmd_nclass; cl++, pci++, pcd++) { 2934 pci->pm_caps = pcd->pcd_caps; 2935 pci->pm_class = pcd->pcd_class; 2936 pci->pm_width = pcd->pcd_width; 2937 pci->pm_num = pcd->pcd_num; 2938 } 2939 error = copyout(&gci, arg, sizeof(gci)); 2940 } 2941 break; 2942 2943 /* 2944 * Retrieve soft events list. 2945 */ 2946 case PMC_OP_GETDYNEVENTINFO: 2947 { 2948 enum pmc_class cl; 2949 enum pmc_event ev; 2950 struct pmc_op_getdyneventinfo *gei; 2951 struct pmc_dyn_event_descr dev; 2952 struct pmc_soft *ps; 2953 uint32_t nevent; 2954 2955 sx_assert(&pmc_sx, SX_LOCKED); 2956 2957 gei = (struct pmc_op_getdyneventinfo *) arg; 2958 2959 if ((error = copyin(&gei->pm_class, &cl, sizeof(cl))) != 0) 2960 break; 2961 2962 /* Only SOFT class is dynamic. */ 2963 if (cl != PMC_CLASS_SOFT) { 2964 error = EINVAL; 2965 break; 2966 } 2967 2968 nevent = 0; 2969 for (ev = PMC_EV_SOFT_FIRST; (int)ev <= PMC_EV_SOFT_LAST; ev++) { 2970 ps = pmc_soft_ev_acquire(ev); 2971 if (ps == NULL) 2972 continue; 2973 bcopy(&ps->ps_ev, &dev, sizeof(dev)); 2974 pmc_soft_ev_release(ps); 2975 2976 error = copyout(&dev, 2977 &gei->pm_events[nevent], 2978 sizeof(struct pmc_dyn_event_descr)); 2979 if (error != 0) 2980 break; 2981 nevent++; 2982 } 2983 if (error != 0) 2984 break; 2985 2986 error = copyout(&nevent, &gei->pm_nevent, 2987 sizeof(nevent)); 2988 } 2989 break; 2990 2991 /* 2992 * Get module statistics 2993 */ 2994 2995 case PMC_OP_GETDRIVERSTATS: 2996 { 2997 struct pmc_op_getdriverstats gms; 2998 2999 bcopy(&pmc_stats, &gms, sizeof(gms)); 3000 error = copyout(&gms, arg, sizeof(gms)); 3001 } 3002 break; 3003 3004 3005 /* 3006 * Retrieve module version number 3007 */ 3008 3009 case PMC_OP_GETMODULEVERSION: 3010 { 3011 uint32_t cv, modv; 3012 3013 /* retrieve the client's idea of the ABI version */ 3014 if ((error = copyin(arg, &cv, sizeof(uint32_t))) != 0) 3015 break; 3016 /* don't service clients newer than our driver */ 3017 modv = PMC_VERSION; 3018 if ((cv & 0xFFFF0000) > (modv & 0xFFFF0000)) { 3019 error = EPROGMISMATCH; 3020 break; 3021 } 3022 error = copyout(&modv, arg, sizeof(int)); 3023 } 3024 break; 3025 3026 3027 /* 3028 * Retrieve the state of all the PMCs on a given 3029 * CPU. 3030 */ 3031 3032 case PMC_OP_GETPMCINFO: 3033 { 3034 int ari; 3035 struct pmc *pm; 3036 size_t pmcinfo_size; 3037 uint32_t cpu, n, npmc; 3038 struct pmc_owner *po; 3039 struct pmc_binding pb; 3040 struct pmc_classdep *pcd; 3041 struct pmc_info *p, *pmcinfo; 3042 struct pmc_op_getpmcinfo *gpi; 3043 3044 PMC_DOWNGRADE_SX(); 3045 3046 gpi = (struct pmc_op_getpmcinfo *) arg; 3047 3048 if ((error = copyin(&gpi->pm_cpu, &cpu, sizeof(cpu))) != 0) 3049 break; 3050 3051 if (cpu >= pmc_cpu_max()) { 3052 error = EINVAL; 3053 break; 3054 } 3055 3056 if (!pmc_cpu_is_active(cpu)) { 3057 error = ENXIO; 3058 break; 3059 } 3060 3061 /* switch to CPU 'cpu' */ 3062 pmc_save_cpu_binding(&pb); 3063 pmc_select_cpu(cpu); 3064 3065 npmc = md->pmd_npmc; 3066 3067 pmcinfo_size = npmc * sizeof(struct pmc_info); 3068 pmcinfo = malloc(pmcinfo_size, M_PMC, M_WAITOK); 3069 3070 p = pmcinfo; 3071 3072 for (n = 0; n < md->pmd_npmc; n++, p++) { 3073 3074 pcd = pmc_ri_to_classdep(md, n, &ari); 3075 3076 KASSERT(pcd != NULL, 3077 ("[pmc,%d] null pcd ri=%d", __LINE__, n)); 3078 3079 if ((error = pcd->pcd_describe(cpu, ari, p, &pm)) != 0) 3080 break; 3081 3082 if (PMC_ROW_DISP_IS_STANDALONE(n)) 3083 p->pm_rowdisp = PMC_DISP_STANDALONE; 3084 else if (PMC_ROW_DISP_IS_THREAD(n)) 3085 p->pm_rowdisp = PMC_DISP_THREAD; 3086 else 3087 p->pm_rowdisp = PMC_DISP_FREE; 3088 3089 p->pm_ownerpid = -1; 3090 3091 if (pm == NULL) /* no PMC associated */ 3092 continue; 3093 3094 po = pm->pm_owner; 3095 3096 KASSERT(po->po_owner != NULL, 3097 ("[pmc,%d] pmc_owner had a null proc pointer", 3098 __LINE__)); 3099 3100 p->pm_ownerpid = po->po_owner->p_pid; 3101 p->pm_mode = PMC_TO_MODE(pm); 3102 p->pm_event = pm->pm_event; 3103 p->pm_flags = pm->pm_flags; 3104 3105 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 3106 p->pm_reloadcount = 3107 pm->pm_sc.pm_reloadcount; 3108 } 3109 3110 pmc_restore_cpu_binding(&pb); 3111 3112 /* now copy out the PMC info collected */ 3113 if (error == 0) 3114 error = copyout(pmcinfo, &gpi->pm_pmcs, pmcinfo_size); 3115 3116 free(pmcinfo, M_PMC); 3117 } 3118 break; 3119 3120 3121 /* 3122 * Set the administrative state of a PMC. I.e. whether 3123 * the PMC is to be used or not. 3124 */ 3125 3126 case PMC_OP_PMCADMIN: 3127 { 3128 int cpu, ri; 3129 enum pmc_state request; 3130 struct pmc_cpu *pc; 3131 struct pmc_hw *phw; 3132 struct pmc_op_pmcadmin pma; 3133 struct pmc_binding pb; 3134 3135 sx_assert(&pmc_sx, SX_XLOCKED); 3136 3137 KASSERT(td == curthread, 3138 ("[pmc,%d] td != curthread", __LINE__)); 3139 3140 error = priv_check(td, PRIV_PMC_MANAGE); 3141 if (error) 3142 break; 3143 3144 if ((error = copyin(arg, &pma, sizeof(pma))) != 0) 3145 break; 3146 3147 cpu = pma.pm_cpu; 3148 3149 if (cpu < 0 || cpu >= (int) pmc_cpu_max()) { 3150 error = EINVAL; 3151 break; 3152 } 3153 3154 if (!pmc_cpu_is_active(cpu)) { 3155 error = ENXIO; 3156 break; 3157 } 3158 3159 request = pma.pm_state; 3160 3161 if (request != PMC_STATE_DISABLED && 3162 request != PMC_STATE_FREE) { 3163 error = EINVAL; 3164 break; 3165 } 3166 3167 ri = pma.pm_pmc; /* pmc id == row index */ 3168 if (ri < 0 || ri >= (int) md->pmd_npmc) { 3169 error = EINVAL; 3170 break; 3171 } 3172 3173 /* 3174 * We can't disable a PMC with a row-index allocated 3175 * for process virtual PMCs. 3176 */ 3177 3178 if (PMC_ROW_DISP_IS_THREAD(ri) && 3179 request == PMC_STATE_DISABLED) { 3180 error = EBUSY; 3181 break; 3182 } 3183 3184 /* 3185 * otherwise, this PMC on this CPU is either free or 3186 * in system-wide mode. 3187 */ 3188 3189 pmc_save_cpu_binding(&pb); 3190 pmc_select_cpu(cpu); 3191 3192 pc = pmc_pcpu[cpu]; 3193 phw = pc->pc_hwpmcs[ri]; 3194 3195 /* 3196 * XXX do we need some kind of 'forced' disable? 3197 */ 3198 3199 if (phw->phw_pmc == NULL) { 3200 if (request == PMC_STATE_DISABLED && 3201 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED)) { 3202 phw->phw_state &= ~PMC_PHW_FLAG_IS_ENABLED; 3203 PMC_MARK_ROW_STANDALONE(ri); 3204 } else if (request == PMC_STATE_FREE && 3205 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0) { 3206 phw->phw_state |= PMC_PHW_FLAG_IS_ENABLED; 3207 PMC_UNMARK_ROW_STANDALONE(ri); 3208 } 3209 /* other cases are a no-op */ 3210 } else 3211 error = EBUSY; 3212 3213 pmc_restore_cpu_binding(&pb); 3214 } 3215 break; 3216 3217 3218 /* 3219 * Allocate a PMC. 3220 */ 3221 3222 case PMC_OP_PMCALLOCATE: 3223 { 3224 int adjri, n; 3225 u_int cpu; 3226 uint32_t caps; 3227 struct pmc *pmc; 3228 enum pmc_mode mode; 3229 struct pmc_hw *phw; 3230 struct pmc_binding pb; 3231 struct pmc_classdep *pcd; 3232 struct pmc_op_pmcallocate pa; 3233 3234 if ((error = copyin(arg, &pa, sizeof(pa))) != 0) 3235 break; 3236 3237 caps = pa.pm_caps; 3238 mode = pa.pm_mode; 3239 cpu = pa.pm_cpu; 3240 3241 if ((mode != PMC_MODE_SS && mode != PMC_MODE_SC && 3242 mode != PMC_MODE_TS && mode != PMC_MODE_TC) || 3243 (cpu != (u_int) PMC_CPU_ANY && cpu >= pmc_cpu_max())) { 3244 error = EINVAL; 3245 break; 3246 } 3247 3248 /* 3249 * Virtual PMCs should only ask for a default CPU. 3250 * System mode PMCs need to specify a non-default CPU. 3251 */ 3252 3253 if ((PMC_IS_VIRTUAL_MODE(mode) && cpu != (u_int) PMC_CPU_ANY) || 3254 (PMC_IS_SYSTEM_MODE(mode) && cpu == (u_int) PMC_CPU_ANY)) { 3255 error = EINVAL; 3256 break; 3257 } 3258 3259 /* 3260 * Check that an inactive CPU is not being asked for. 3261 */ 3262 3263 if (PMC_IS_SYSTEM_MODE(mode) && !pmc_cpu_is_active(cpu)) { 3264 error = ENXIO; 3265 break; 3266 } 3267 3268 /* 3269 * Refuse an allocation for a system-wide PMC if this 3270 * process has been jailed, or if this process lacks 3271 * super-user credentials and the sysctl tunable 3272 * 'security.bsd.unprivileged_syspmcs' is zero. 3273 */ 3274 3275 if (PMC_IS_SYSTEM_MODE(mode)) { 3276 if (jailed(curthread->td_ucred)) { 3277 error = EPERM; 3278 break; 3279 } 3280 if (!pmc_unprivileged_syspmcs) { 3281 error = priv_check(curthread, 3282 PRIV_PMC_SYSTEM); 3283 if (error) 3284 break; 3285 } 3286 } 3287 3288 /* 3289 * Look for valid values for 'pm_flags' 3290 */ 3291 3292 if ((pa.pm_flags & ~(PMC_F_DESCENDANTS | PMC_F_LOG_PROCCSW | 3293 PMC_F_LOG_PROCEXIT | PMC_F_CALLCHAIN)) != 0) { 3294 error = EINVAL; 3295 break; 3296 } 3297 3298 /* process logging options are not allowed for system PMCs */ 3299 if (PMC_IS_SYSTEM_MODE(mode) && (pa.pm_flags & 3300 (PMC_F_LOG_PROCCSW | PMC_F_LOG_PROCEXIT))) { 3301 error = EINVAL; 3302 break; 3303 } 3304 3305 /* 3306 * All sampling mode PMCs need to be able to interrupt the 3307 * CPU. 3308 */ 3309 if (PMC_IS_SAMPLING_MODE(mode)) 3310 caps |= PMC_CAP_INTERRUPT; 3311 3312 /* A valid class specifier should have been passed in. */ 3313 for (n = 0; n < md->pmd_nclass; n++) 3314 if (md->pmd_classdep[n].pcd_class == pa.pm_class) 3315 break; 3316 if (n == md->pmd_nclass) { 3317 error = EINVAL; 3318 break; 3319 } 3320 3321 /* The requested PMC capabilities should be feasible. */ 3322 if ((md->pmd_classdep[n].pcd_caps & caps) != caps) { 3323 error = EOPNOTSUPP; 3324 break; 3325 } 3326 3327 PMCDBG(PMC,ALL,2, "event=%d caps=0x%x mode=%d cpu=%d", 3328 pa.pm_ev, caps, mode, cpu); 3329 3330 pmc = pmc_allocate_pmc_descriptor(); 3331 pmc->pm_id = PMC_ID_MAKE_ID(cpu,pa.pm_mode,pa.pm_class, 3332 PMC_ID_INVALID); 3333 pmc->pm_event = pa.pm_ev; 3334 pmc->pm_state = PMC_STATE_FREE; 3335 pmc->pm_caps = caps; 3336 pmc->pm_flags = pa.pm_flags; 3337 3338 /* switch thread to CPU 'cpu' */ 3339 pmc_save_cpu_binding(&pb); 3340 3341 #define PMC_IS_SHAREABLE_PMC(cpu, n) \ 3342 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_state & \ 3343 PMC_PHW_FLAG_IS_SHAREABLE) 3344 #define PMC_IS_UNALLOCATED(cpu, n) \ 3345 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_pmc == NULL) 3346 3347 if (PMC_IS_SYSTEM_MODE(mode)) { 3348 pmc_select_cpu(cpu); 3349 for (n = 0; n < (int) md->pmd_npmc; n++) { 3350 pcd = pmc_ri_to_classdep(md, n, &adjri); 3351 if (pmc_can_allocate_row(n, mode) == 0 && 3352 pmc_can_allocate_rowindex( 3353 curthread->td_proc, n, cpu) == 0 && 3354 (PMC_IS_UNALLOCATED(cpu, n) || 3355 PMC_IS_SHAREABLE_PMC(cpu, n)) && 3356 pcd->pcd_allocate_pmc(cpu, adjri, pmc, 3357 &pa) == 0) 3358 break; 3359 } 3360 } else { 3361 /* Process virtual mode */ 3362 for (n = 0; n < (int) md->pmd_npmc; n++) { 3363 pcd = pmc_ri_to_classdep(md, n, &adjri); 3364 if (pmc_can_allocate_row(n, mode) == 0 && 3365 pmc_can_allocate_rowindex( 3366 curthread->td_proc, n, 3367 PMC_CPU_ANY) == 0 && 3368 pcd->pcd_allocate_pmc(curthread->td_oncpu, 3369 adjri, pmc, &pa) == 0) 3370 break; 3371 } 3372 } 3373 3374 #undef PMC_IS_UNALLOCATED 3375 #undef PMC_IS_SHAREABLE_PMC 3376 3377 pmc_restore_cpu_binding(&pb); 3378 3379 if (n == (int) md->pmd_npmc) { 3380 pmc_destroy_pmc_descriptor(pmc); 3381 free(pmc, M_PMC); 3382 pmc = NULL; 3383 error = EINVAL; 3384 break; 3385 } 3386 3387 /* Fill in the correct value in the ID field */ 3388 pmc->pm_id = PMC_ID_MAKE_ID(cpu,mode,pa.pm_class,n); 3389 3390 PMCDBG(PMC,ALL,2, "ev=%d class=%d mode=%d n=%d -> pmcid=%x", 3391 pmc->pm_event, pa.pm_class, mode, n, pmc->pm_id); 3392 3393 /* Process mode PMCs with logging enabled need log files */ 3394 if (pmc->pm_flags & (PMC_F_LOG_PROCEXIT | PMC_F_LOG_PROCCSW)) 3395 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3396 3397 /* All system mode sampling PMCs require a log file */ 3398 if (PMC_IS_SAMPLING_MODE(mode) && PMC_IS_SYSTEM_MODE(mode)) 3399 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3400 3401 /* 3402 * Configure global pmc's immediately 3403 */ 3404 3405 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pmc))) { 3406 3407 pmc_save_cpu_binding(&pb); 3408 pmc_select_cpu(cpu); 3409 3410 phw = pmc_pcpu[cpu]->pc_hwpmcs[n]; 3411 pcd = pmc_ri_to_classdep(md, n, &adjri); 3412 3413 if ((phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0 || 3414 (error = pcd->pcd_config_pmc(cpu, adjri, pmc)) != 0) { 3415 (void) pcd->pcd_release_pmc(cpu, adjri, pmc); 3416 pmc_destroy_pmc_descriptor(pmc); 3417 free(pmc, M_PMC); 3418 pmc = NULL; 3419 pmc_restore_cpu_binding(&pb); 3420 error = EPERM; 3421 break; 3422 } 3423 3424 pmc_restore_cpu_binding(&pb); 3425 } 3426 3427 pmc->pm_state = PMC_STATE_ALLOCATED; 3428 3429 /* 3430 * mark row disposition 3431 */ 3432 3433 if (PMC_IS_SYSTEM_MODE(mode)) 3434 PMC_MARK_ROW_STANDALONE(n); 3435 else 3436 PMC_MARK_ROW_THREAD(n); 3437 3438 /* 3439 * Register this PMC with the current thread as its owner. 3440 */ 3441 3442 if ((error = 3443 pmc_register_owner(curthread->td_proc, pmc)) != 0) { 3444 pmc_release_pmc_descriptor(pmc); 3445 free(pmc, M_PMC); 3446 pmc = NULL; 3447 break; 3448 } 3449 3450 /* 3451 * Return the allocated index. 3452 */ 3453 3454 pa.pm_pmcid = pmc->pm_id; 3455 3456 error = copyout(&pa, arg, sizeof(pa)); 3457 } 3458 break; 3459 3460 3461 /* 3462 * Attach a PMC to a process. 3463 */ 3464 3465 case PMC_OP_PMCATTACH: 3466 { 3467 struct pmc *pm; 3468 struct proc *p; 3469 struct pmc_op_pmcattach a; 3470 3471 sx_assert(&pmc_sx, SX_XLOCKED); 3472 3473 if ((error = copyin(arg, &a, sizeof(a))) != 0) 3474 break; 3475 3476 if (a.pm_pid < 0) { 3477 error = EINVAL; 3478 break; 3479 } else if (a.pm_pid == 0) 3480 a.pm_pid = td->td_proc->p_pid; 3481 3482 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 3483 break; 3484 3485 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) { 3486 error = EINVAL; 3487 break; 3488 } 3489 3490 /* PMCs may be (re)attached only when allocated or stopped */ 3491 if (pm->pm_state == PMC_STATE_RUNNING) { 3492 error = EBUSY; 3493 break; 3494 } else if (pm->pm_state != PMC_STATE_ALLOCATED && 3495 pm->pm_state != PMC_STATE_STOPPED) { 3496 error = EINVAL; 3497 break; 3498 } 3499 3500 /* lookup pid */ 3501 if ((p = pfind(a.pm_pid)) == NULL) { 3502 error = ESRCH; 3503 break; 3504 } 3505 3506 /* 3507 * Ignore processes that are working on exiting. 3508 */ 3509 if (p->p_flag & P_WEXIT) { 3510 error = ESRCH; 3511 PROC_UNLOCK(p); /* pfind() returns a locked process */ 3512 break; 3513 } 3514 3515 /* 3516 * we are allowed to attach a PMC to a process if 3517 * we can debug it. 3518 */ 3519 error = p_candebug(curthread, p); 3520 3521 PROC_UNLOCK(p); 3522 3523 if (error == 0) 3524 error = pmc_attach_process(p, pm); 3525 } 3526 break; 3527 3528 3529 /* 3530 * Detach an attached PMC from a process. 3531 */ 3532 3533 case PMC_OP_PMCDETACH: 3534 { 3535 struct pmc *pm; 3536 struct proc *p; 3537 struct pmc_op_pmcattach a; 3538 3539 if ((error = copyin(arg, &a, sizeof(a))) != 0) 3540 break; 3541 3542 if (a.pm_pid < 0) { 3543 error = EINVAL; 3544 break; 3545 } else if (a.pm_pid == 0) 3546 a.pm_pid = td->td_proc->p_pid; 3547 3548 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 3549 break; 3550 3551 if ((p = pfind(a.pm_pid)) == NULL) { 3552 error = ESRCH; 3553 break; 3554 } 3555 3556 /* 3557 * Treat processes that are in the process of exiting 3558 * as if they were not present. 3559 */ 3560 3561 if (p->p_flag & P_WEXIT) 3562 error = ESRCH; 3563 3564 PROC_UNLOCK(p); /* pfind() returns a locked process */ 3565 3566 if (error == 0) 3567 error = pmc_detach_process(p, pm); 3568 } 3569 break; 3570 3571 3572 /* 3573 * Retrieve the MSR number associated with the counter 3574 * 'pmc_id'. This allows processes to directly use RDPMC 3575 * instructions to read their PMCs, without the overhead of a 3576 * system call. 3577 */ 3578 3579 case PMC_OP_PMCGETMSR: 3580 { 3581 int adjri, ri; 3582 struct pmc *pm; 3583 struct pmc_target *pt; 3584 struct pmc_op_getmsr gm; 3585 struct pmc_classdep *pcd; 3586 3587 PMC_DOWNGRADE_SX(); 3588 3589 if ((error = copyin(arg, &gm, sizeof(gm))) != 0) 3590 break; 3591 3592 if ((error = pmc_find_pmc(gm.pm_pmcid, &pm)) != 0) 3593 break; 3594 3595 /* 3596 * The allocated PMC has to be a process virtual PMC, 3597 * i.e., of type MODE_T[CS]. Global PMCs can only be 3598 * read using the PMCREAD operation since they may be 3599 * allocated on a different CPU than the one we could 3600 * be running on at the time of the RDPMC instruction. 3601 * 3602 * The GETMSR operation is not allowed for PMCs that 3603 * are inherited across processes. 3604 */ 3605 3606 if (!PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)) || 3607 (pm->pm_flags & PMC_F_DESCENDANTS)) { 3608 error = EINVAL; 3609 break; 3610 } 3611 3612 /* 3613 * It only makes sense to use a RDPMC (or its 3614 * equivalent instruction on non-x86 architectures) on 3615 * a process that has allocated and attached a PMC to 3616 * itself. Conversely the PMC is only allowed to have 3617 * one process attached to it -- its owner. 3618 */ 3619 3620 if ((pt = LIST_FIRST(&pm->pm_targets)) == NULL || 3621 LIST_NEXT(pt, pt_next) != NULL || 3622 pt->pt_process->pp_proc != pm->pm_owner->po_owner) { 3623 error = EINVAL; 3624 break; 3625 } 3626 3627 ri = PMC_TO_ROWINDEX(pm); 3628 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3629 3630 /* PMC class has no 'GETMSR' support */ 3631 if (pcd->pcd_get_msr == NULL) { 3632 error = ENOSYS; 3633 break; 3634 } 3635 3636 if ((error = (*pcd->pcd_get_msr)(adjri, &gm.pm_msr)) < 0) 3637 break; 3638 3639 if ((error = copyout(&gm, arg, sizeof(gm))) < 0) 3640 break; 3641 3642 /* 3643 * Mark our process as using MSRs. Update machine 3644 * state using a forced context switch. 3645 */ 3646 3647 pt->pt_process->pp_flags |= PMC_PP_ENABLE_MSR_ACCESS; 3648 pmc_force_context_switch(); 3649 3650 } 3651 break; 3652 3653 /* 3654 * Release an allocated PMC 3655 */ 3656 3657 case PMC_OP_PMCRELEASE: 3658 { 3659 pmc_id_t pmcid; 3660 struct pmc *pm; 3661 struct pmc_owner *po; 3662 struct pmc_op_simple sp; 3663 3664 /* 3665 * Find PMC pointer for the named PMC. 3666 * 3667 * Use pmc_release_pmc_descriptor() to switch off the 3668 * PMC, remove all its target threads, and remove the 3669 * PMC from its owner's list. 3670 * 3671 * Remove the owner record if this is the last PMC 3672 * owned. 3673 * 3674 * Free up space. 3675 */ 3676 3677 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3678 break; 3679 3680 pmcid = sp.pm_pmcid; 3681 3682 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3683 break; 3684 3685 po = pm->pm_owner; 3686 pmc_release_pmc_descriptor(pm); 3687 pmc_maybe_remove_owner(po); 3688 3689 free(pm, M_PMC); 3690 } 3691 break; 3692 3693 3694 /* 3695 * Read and/or write a PMC. 3696 */ 3697 3698 case PMC_OP_PMCRW: 3699 { 3700 int adjri; 3701 struct pmc *pm; 3702 uint32_t cpu, ri; 3703 pmc_value_t oldvalue; 3704 struct pmc_binding pb; 3705 struct pmc_op_pmcrw prw; 3706 struct pmc_classdep *pcd; 3707 struct pmc_op_pmcrw *pprw; 3708 3709 PMC_DOWNGRADE_SX(); 3710 3711 if ((error = copyin(arg, &prw, sizeof(prw))) != 0) 3712 break; 3713 3714 ri = 0; 3715 PMCDBG(PMC,OPS,1, "rw id=%d flags=0x%x", prw.pm_pmcid, 3716 prw.pm_flags); 3717 3718 /* must have at least one flag set */ 3719 if ((prw.pm_flags & (PMC_F_OLDVALUE|PMC_F_NEWVALUE)) == 0) { 3720 error = EINVAL; 3721 break; 3722 } 3723 3724 /* locate pmc descriptor */ 3725 if ((error = pmc_find_pmc(prw.pm_pmcid, &pm)) != 0) 3726 break; 3727 3728 /* Can't read a PMC that hasn't been started. */ 3729 if (pm->pm_state != PMC_STATE_ALLOCATED && 3730 pm->pm_state != PMC_STATE_STOPPED && 3731 pm->pm_state != PMC_STATE_RUNNING) { 3732 error = EINVAL; 3733 break; 3734 } 3735 3736 /* writing a new value is allowed only for 'STOPPED' pmcs */ 3737 if (pm->pm_state == PMC_STATE_RUNNING && 3738 (prw.pm_flags & PMC_F_NEWVALUE)) { 3739 error = EBUSY; 3740 break; 3741 } 3742 3743 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) { 3744 3745 /* 3746 * If this PMC is attached to its owner (i.e., 3747 * the process requesting this operation) and 3748 * is running, then attempt to get an 3749 * upto-date reading from hardware for a READ. 3750 * Writes are only allowed when the PMC is 3751 * stopped, so only update the saved value 3752 * field. 3753 * 3754 * If the PMC is not running, or is not 3755 * attached to its owner, read/write to the 3756 * savedvalue field. 3757 */ 3758 3759 ri = PMC_TO_ROWINDEX(pm); 3760 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3761 3762 mtx_pool_lock_spin(pmc_mtxpool, pm); 3763 cpu = curthread->td_oncpu; 3764 3765 if (prw.pm_flags & PMC_F_OLDVALUE) { 3766 if ((pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) && 3767 (pm->pm_state == PMC_STATE_RUNNING)) 3768 error = (*pcd->pcd_read_pmc)(cpu, adjri, 3769 &oldvalue); 3770 else 3771 oldvalue = pm->pm_gv.pm_savedvalue; 3772 } 3773 if (prw.pm_flags & PMC_F_NEWVALUE) 3774 pm->pm_gv.pm_savedvalue = prw.pm_value; 3775 3776 mtx_pool_unlock_spin(pmc_mtxpool, pm); 3777 3778 } else { /* System mode PMCs */ 3779 cpu = PMC_TO_CPU(pm); 3780 ri = PMC_TO_ROWINDEX(pm); 3781 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3782 3783 if (!pmc_cpu_is_active(cpu)) { 3784 error = ENXIO; 3785 break; 3786 } 3787 3788 /* move this thread to CPU 'cpu' */ 3789 pmc_save_cpu_binding(&pb); 3790 pmc_select_cpu(cpu); 3791 3792 critical_enter(); 3793 /* save old value */ 3794 if (prw.pm_flags & PMC_F_OLDVALUE) 3795 if ((error = (*pcd->pcd_read_pmc)(cpu, adjri, 3796 &oldvalue))) 3797 goto error; 3798 /* write out new value */ 3799 if (prw.pm_flags & PMC_F_NEWVALUE) 3800 error = (*pcd->pcd_write_pmc)(cpu, adjri, 3801 prw.pm_value); 3802 error: 3803 critical_exit(); 3804 pmc_restore_cpu_binding(&pb); 3805 if (error) 3806 break; 3807 } 3808 3809 pprw = (struct pmc_op_pmcrw *) arg; 3810 3811 #ifdef DEBUG 3812 if (prw.pm_flags & PMC_F_NEWVALUE) 3813 PMCDBG(PMC,OPS,2, "rw id=%d new %jx -> old %jx", 3814 ri, prw.pm_value, oldvalue); 3815 else if (prw.pm_flags & PMC_F_OLDVALUE) 3816 PMCDBG(PMC,OPS,2, "rw id=%d -> old %jx", ri, oldvalue); 3817 #endif 3818 3819 /* return old value if requested */ 3820 if (prw.pm_flags & PMC_F_OLDVALUE) 3821 if ((error = copyout(&oldvalue, &pprw->pm_value, 3822 sizeof(prw.pm_value)))) 3823 break; 3824 3825 } 3826 break; 3827 3828 3829 /* 3830 * Set the sampling rate for a sampling mode PMC and the 3831 * initial count for a counting mode PMC. 3832 */ 3833 3834 case PMC_OP_PMCSETCOUNT: 3835 { 3836 struct pmc *pm; 3837 struct pmc_op_pmcsetcount sc; 3838 3839 PMC_DOWNGRADE_SX(); 3840 3841 if ((error = copyin(arg, &sc, sizeof(sc))) != 0) 3842 break; 3843 3844 if ((error = pmc_find_pmc(sc.pm_pmcid, &pm)) != 0) 3845 break; 3846 3847 if (pm->pm_state == PMC_STATE_RUNNING) { 3848 error = EBUSY; 3849 break; 3850 } 3851 3852 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 3853 pm->pm_sc.pm_reloadcount = sc.pm_count; 3854 else 3855 pm->pm_sc.pm_initial = sc.pm_count; 3856 } 3857 break; 3858 3859 3860 /* 3861 * Start a PMC. 3862 */ 3863 3864 case PMC_OP_PMCSTART: 3865 { 3866 pmc_id_t pmcid; 3867 struct pmc *pm; 3868 struct pmc_op_simple sp; 3869 3870 sx_assert(&pmc_sx, SX_XLOCKED); 3871 3872 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3873 break; 3874 3875 pmcid = sp.pm_pmcid; 3876 3877 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3878 break; 3879 3880 KASSERT(pmcid == pm->pm_id, 3881 ("[pmc,%d] pmcid %x != id %x", __LINE__, 3882 pm->pm_id, pmcid)); 3883 3884 if (pm->pm_state == PMC_STATE_RUNNING) /* already running */ 3885 break; 3886 else if (pm->pm_state != PMC_STATE_STOPPED && 3887 pm->pm_state != PMC_STATE_ALLOCATED) { 3888 error = EINVAL; 3889 break; 3890 } 3891 3892 error = pmc_start(pm); 3893 } 3894 break; 3895 3896 3897 /* 3898 * Stop a PMC. 3899 */ 3900 3901 case PMC_OP_PMCSTOP: 3902 { 3903 pmc_id_t pmcid; 3904 struct pmc *pm; 3905 struct pmc_op_simple sp; 3906 3907 PMC_DOWNGRADE_SX(); 3908 3909 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3910 break; 3911 3912 pmcid = sp.pm_pmcid; 3913 3914 /* 3915 * Mark the PMC as inactive and invoke the MD stop 3916 * routines if needed. 3917 */ 3918 3919 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3920 break; 3921 3922 KASSERT(pmcid == pm->pm_id, 3923 ("[pmc,%d] pmc id %x != pmcid %x", __LINE__, 3924 pm->pm_id, pmcid)); 3925 3926 if (pm->pm_state == PMC_STATE_STOPPED) /* already stopped */ 3927 break; 3928 else if (pm->pm_state != PMC_STATE_RUNNING) { 3929 error = EINVAL; 3930 break; 3931 } 3932 3933 error = pmc_stop(pm); 3934 } 3935 break; 3936 3937 3938 /* 3939 * Write a user supplied value to the log file. 3940 */ 3941 3942 case PMC_OP_WRITELOG: 3943 { 3944 struct pmc_op_writelog wl; 3945 struct pmc_owner *po; 3946 3947 PMC_DOWNGRADE_SX(); 3948 3949 if ((error = copyin(arg, &wl, sizeof(wl))) != 0) 3950 break; 3951 3952 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 3953 error = EINVAL; 3954 break; 3955 } 3956 3957 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) { 3958 error = EINVAL; 3959 break; 3960 } 3961 3962 error = pmclog_process_userlog(po, &wl); 3963 } 3964 break; 3965 3966 3967 default: 3968 error = EINVAL; 3969 break; 3970 } 3971 3972 if (is_sx_locked != 0) { 3973 if (is_sx_downgraded) 3974 sx_sunlock(&pmc_sx); 3975 else 3976 sx_xunlock(&pmc_sx); 3977 } 3978 3979 if (error) 3980 atomic_add_int(&pmc_stats.pm_syscall_errors, 1); 3981 3982 PICKUP_GIANT(); 3983 3984 return error; 3985 } 3986 3987 /* 3988 * Helper functions 3989 */ 3990 3991 3992 /* 3993 * Mark the thread as needing callchain capture and post an AST. The 3994 * actual callchain capture will be done in a context where it is safe 3995 * to take page faults. 3996 */ 3997 3998 static void 3999 pmc_post_callchain_callback(void) 4000 { 4001 struct thread *td; 4002 4003 td = curthread; 4004 4005 /* 4006 * If there is multiple PMCs for the same interrupt ignore new post 4007 */ 4008 if (td->td_pflags & TDP_CALLCHAIN) 4009 return; 4010 4011 /* 4012 * Mark this thread as needing callchain capture. 4013 * `td->td_pflags' will be safe to touch because this thread 4014 * was in user space when it was interrupted. 4015 */ 4016 td->td_pflags |= TDP_CALLCHAIN; 4017 4018 /* 4019 * Don't let this thread migrate between CPUs until callchain 4020 * capture completes. 4021 */ 4022 sched_pin(); 4023 4024 return; 4025 } 4026 4027 /* 4028 * Interrupt processing. 4029 * 4030 * Find a free slot in the per-cpu array of samples and capture the 4031 * current callchain there. If a sample was successfully added, a bit 4032 * is set in mask 'pmc_cpumask' denoting that the DO_SAMPLES hook 4033 * needs to be invoked from the clock handler. 4034 * 4035 * This function is meant to be called from an NMI handler. It cannot 4036 * use any of the locking primitives supplied by the OS. 4037 */ 4038 4039 int 4040 pmc_process_interrupt(int cpu, int ring, struct pmc *pm, struct trapframe *tf, 4041 int inuserspace) 4042 { 4043 int error, callchaindepth; 4044 struct thread *td; 4045 struct pmc_sample *ps; 4046 struct pmc_samplebuffer *psb; 4047 4048 error = 0; 4049 4050 /* 4051 * Allocate space for a sample buffer. 4052 */ 4053 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4054 4055 ps = psb->ps_write; 4056 if (ps->ps_nsamples) { /* in use, reader hasn't caught up */ 4057 pm->pm_stalled = 1; 4058 atomic_add_int(&pmc_stats.pm_intr_bufferfull, 1); 4059 PMCDBG(SAM,INT,1,"(spc) cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", 4060 cpu, pm, (void *) tf, inuserspace, 4061 (int) (psb->ps_write - psb->ps_samples), 4062 (int) (psb->ps_read - psb->ps_samples)); 4063 error = ENOMEM; 4064 goto done; 4065 } 4066 4067 4068 /* Fill in entry. */ 4069 PMCDBG(SAM,INT,1,"cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", cpu, pm, 4070 (void *) tf, inuserspace, 4071 (int) (psb->ps_write - psb->ps_samples), 4072 (int) (psb->ps_read - psb->ps_samples)); 4073 4074 KASSERT(pm->pm_runcount >= 0, 4075 ("[pmc,%d] pm=%p runcount %d", __LINE__, (void *) pm, 4076 pm->pm_runcount)); 4077 4078 atomic_add_rel_int(&pm->pm_runcount, 1); /* hold onto PMC */ 4079 4080 ps->ps_pmc = pm; 4081 if ((td = curthread) && td->td_proc) 4082 ps->ps_pid = td->td_proc->p_pid; 4083 else 4084 ps->ps_pid = -1; 4085 ps->ps_cpu = cpu; 4086 ps->ps_td = td; 4087 ps->ps_flags = inuserspace ? PMC_CC_F_USERSPACE : 0; 4088 4089 callchaindepth = (pm->pm_flags & PMC_F_CALLCHAIN) ? 4090 pmc_callchaindepth : 1; 4091 4092 if (callchaindepth == 1) 4093 ps->ps_pc[0] = PMC_TRAPFRAME_TO_PC(tf); 4094 else { 4095 /* 4096 * Kernel stack traversals can be done immediately, 4097 * while we defer to an AST for user space traversals. 4098 */ 4099 if (!inuserspace) { 4100 callchaindepth = 4101 pmc_save_kernel_callchain(ps->ps_pc, 4102 callchaindepth, tf); 4103 } else { 4104 pmc_post_callchain_callback(); 4105 callchaindepth = PMC_SAMPLE_INUSE; 4106 } 4107 } 4108 4109 ps->ps_nsamples = callchaindepth; /* mark entry as in use */ 4110 4111 /* increment write pointer, modulo ring buffer size */ 4112 ps++; 4113 if (ps == psb->ps_fence) 4114 psb->ps_write = psb->ps_samples; 4115 else 4116 psb->ps_write = ps; 4117 4118 done: 4119 /* mark CPU as needing processing */ 4120 CPU_SET_ATOMIC(cpu, &pmc_cpumask); 4121 4122 return (error); 4123 } 4124 4125 /* 4126 * Capture a user call chain. This function will be called from ast() 4127 * before control returns to userland and before the process gets 4128 * rescheduled. 4129 */ 4130 4131 static void 4132 pmc_capture_user_callchain(int cpu, int ring, struct trapframe *tf) 4133 { 4134 int i; 4135 struct pmc *pm; 4136 struct thread *td; 4137 struct pmc_sample *ps; 4138 struct pmc_samplebuffer *psb; 4139 #ifdef INVARIANTS 4140 int ncallchains; 4141 #endif 4142 4143 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4144 td = curthread; 4145 4146 KASSERT(td->td_pflags & TDP_CALLCHAIN, 4147 ("[pmc,%d] Retrieving callchain for thread that doesn't want it", 4148 __LINE__)); 4149 4150 #ifdef INVARIANTS 4151 ncallchains = 0; 4152 #endif 4153 4154 /* 4155 * Iterate through all deferred callchain requests. 4156 */ 4157 4158 ps = psb->ps_samples; 4159 for (i = 0; i < pmc_nsamples; i++, ps++) { 4160 4161 if (ps->ps_nsamples != PMC_SAMPLE_INUSE) 4162 continue; 4163 if (ps->ps_td != td) 4164 continue; 4165 4166 KASSERT(ps->ps_cpu == cpu, 4167 ("[pmc,%d] cpu mismatch ps_cpu=%d pcpu=%d", __LINE__, 4168 ps->ps_cpu, PCPU_GET(cpuid))); 4169 4170 pm = ps->ps_pmc; 4171 4172 KASSERT(pm->pm_flags & PMC_F_CALLCHAIN, 4173 ("[pmc,%d] Retrieving callchain for PMC that doesn't " 4174 "want it", __LINE__)); 4175 4176 KASSERT(pm->pm_runcount > 0, 4177 ("[pmc,%d] runcount %d", __LINE__, pm->pm_runcount)); 4178 4179 /* 4180 * Retrieve the callchain and mark the sample buffer 4181 * as 'processable' by the timer tick sweep code. 4182 */ 4183 ps->ps_nsamples = pmc_save_user_callchain(ps->ps_pc, 4184 pmc_callchaindepth, tf); 4185 4186 #ifdef INVARIANTS 4187 ncallchains++; 4188 #endif 4189 } 4190 4191 KASSERT(ncallchains > 0, 4192 ("[pmc,%d] cpu %d didn't find a sample to collect", __LINE__, 4193 cpu)); 4194 4195 KASSERT(td->td_pinned == 1, 4196 ("[pmc,%d] invalid td_pinned value", __LINE__)); 4197 sched_unpin(); /* Can migrate safely now. */ 4198 4199 return; 4200 } 4201 4202 /* 4203 * Process saved PC samples. 4204 */ 4205 4206 static void 4207 pmc_process_samples(int cpu, int ring) 4208 { 4209 struct pmc *pm; 4210 int adjri, n; 4211 struct thread *td; 4212 struct pmc_owner *po; 4213 struct pmc_sample *ps; 4214 struct pmc_classdep *pcd; 4215 struct pmc_samplebuffer *psb; 4216 4217 KASSERT(PCPU_GET(cpuid) == cpu, 4218 ("[pmc,%d] not on the correct CPU pcpu=%d cpu=%d", __LINE__, 4219 PCPU_GET(cpuid), cpu)); 4220 4221 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4222 4223 for (n = 0; n < pmc_nsamples; n++) { /* bound on #iterations */ 4224 4225 ps = psb->ps_read; 4226 if (ps->ps_nsamples == PMC_SAMPLE_FREE) 4227 break; 4228 4229 pm = ps->ps_pmc; 4230 4231 KASSERT(pm->pm_runcount > 0, 4232 ("[pmc,%d] pm=%p runcount %d", __LINE__, (void *) pm, 4233 pm->pm_runcount)); 4234 4235 po = pm->pm_owner; 4236 4237 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 4238 ("[pmc,%d] pmc=%p non-sampling mode=%d", __LINE__, 4239 pm, PMC_TO_MODE(pm))); 4240 4241 /* Ignore PMCs that have been switched off */ 4242 if (pm->pm_state != PMC_STATE_RUNNING) 4243 goto entrydone; 4244 4245 /* If there is a pending AST wait for completion */ 4246 if (ps->ps_nsamples == PMC_SAMPLE_INUSE) { 4247 /* Need a rescan at a later time. */ 4248 CPU_SET_ATOMIC(cpu, &pmc_cpumask); 4249 break; 4250 } 4251 4252 PMCDBG(SAM,OPS,1,"cpu=%d pm=%p n=%d fl=%x wr=%d rd=%d", cpu, 4253 pm, ps->ps_nsamples, ps->ps_flags, 4254 (int) (psb->ps_write - psb->ps_samples), 4255 (int) (psb->ps_read - psb->ps_samples)); 4256 4257 /* 4258 * If this is a process-mode PMC that is attached to 4259 * its owner, and if the PC is in user mode, update 4260 * profiling statistics like timer-based profiling 4261 * would have done. 4262 */ 4263 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) { 4264 if (ps->ps_flags & PMC_CC_F_USERSPACE) { 4265 td = FIRST_THREAD_IN_PROC(po->po_owner); 4266 addupc_intr(td, ps->ps_pc[0], 1); 4267 } 4268 goto entrydone; 4269 } 4270 4271 /* 4272 * Otherwise, this is either a sampling mode PMC that 4273 * is attached to a different process than its owner, 4274 * or a system-wide sampling PMC. Dispatch a log 4275 * entry to the PMC's owner process. 4276 */ 4277 pmclog_process_callchain(pm, ps); 4278 4279 entrydone: 4280 ps->ps_nsamples = 0; /* mark entry as free */ 4281 atomic_subtract_rel_int(&pm->pm_runcount, 1); 4282 4283 /* increment read pointer, modulo sample size */ 4284 if (++ps == psb->ps_fence) 4285 psb->ps_read = psb->ps_samples; 4286 else 4287 psb->ps_read = ps; 4288 } 4289 4290 atomic_add_int(&pmc_stats.pm_log_sweeps, 1); 4291 4292 /* Do not re-enable stalled PMCs if we failed to process any samples */ 4293 if (n == 0) 4294 return; 4295 4296 /* 4297 * Restart any stalled sampling PMCs on this CPU. 4298 * 4299 * If the NMI handler sets the pm_stalled field of a PMC after 4300 * the check below, we'll end up processing the stalled PMC at 4301 * the next hardclock tick. 4302 */ 4303 for (n = 0; n < md->pmd_npmc; n++) { 4304 pcd = pmc_ri_to_classdep(md, n, &adjri); 4305 KASSERT(pcd != NULL, 4306 ("[pmc,%d] null pcd ri=%d", __LINE__, n)); 4307 (void) (*pcd->pcd_get_config)(cpu,adjri,&pm); 4308 4309 if (pm == NULL || /* !cfg'ed */ 4310 pm->pm_state != PMC_STATE_RUNNING || /* !active */ 4311 !PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) || /* !sampling */ 4312 pm->pm_stalled == 0) /* !stalled */ 4313 continue; 4314 4315 pm->pm_stalled = 0; 4316 (*pcd->pcd_start_pmc)(cpu, adjri); 4317 } 4318 } 4319 4320 /* 4321 * Event handlers. 4322 */ 4323 4324 /* 4325 * Handle a process exit. 4326 * 4327 * Remove this process from all hash tables. If this process 4328 * owned any PMCs, turn off those PMCs and deallocate them, 4329 * removing any associations with target processes. 4330 * 4331 * This function will be called by the last 'thread' of a 4332 * process. 4333 * 4334 * XXX This eventhandler gets called early in the exit process. 4335 * Consider using a 'hook' invocation from thread_exit() or equivalent 4336 * spot. Another negative is that kse_exit doesn't seem to call 4337 * exit1() [??]. 4338 * 4339 */ 4340 4341 static void 4342 pmc_process_exit(void *arg __unused, struct proc *p) 4343 { 4344 struct pmc *pm; 4345 int adjri, cpu; 4346 unsigned int ri; 4347 int is_using_hwpmcs; 4348 struct pmc_owner *po; 4349 struct pmc_process *pp; 4350 struct pmc_classdep *pcd; 4351 pmc_value_t newvalue, tmp; 4352 4353 PROC_LOCK(p); 4354 is_using_hwpmcs = p->p_flag & P_HWPMC; 4355 PROC_UNLOCK(p); 4356 4357 /* 4358 * Log a sysexit event to all SS PMC owners. 4359 */ 4360 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4361 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4362 pmclog_process_sysexit(po, p->p_pid); 4363 4364 if (!is_using_hwpmcs) 4365 return; 4366 4367 PMC_GET_SX_XLOCK(); 4368 PMCDBG(PRC,EXT,1,"process-exit proc=%p (%d, %s)", p, p->p_pid, 4369 p->p_comm); 4370 4371 /* 4372 * Since this code is invoked by the last thread in an exiting 4373 * process, we would have context switched IN at some prior 4374 * point. However, with PREEMPTION, kernel mode context 4375 * switches may happen any time, so we want to disable a 4376 * context switch OUT till we get any PMCs targetting this 4377 * process off the hardware. 4378 * 4379 * We also need to atomically remove this process' 4380 * entry from our target process hash table, using 4381 * PMC_FLAG_REMOVE. 4382 */ 4383 PMCDBG(PRC,EXT,1, "process-exit proc=%p (%d, %s)", p, p->p_pid, 4384 p->p_comm); 4385 4386 critical_enter(); /* no preemption */ 4387 4388 cpu = curthread->td_oncpu; 4389 4390 if ((pp = pmc_find_process_descriptor(p, 4391 PMC_FLAG_REMOVE)) != NULL) { 4392 4393 PMCDBG(PRC,EXT,2, 4394 "process-exit proc=%p pmc-process=%p", p, pp); 4395 4396 /* 4397 * The exiting process could the target of 4398 * some PMCs which will be running on 4399 * currently executing CPU. 4400 * 4401 * We need to turn these PMCs off like we 4402 * would do at context switch OUT time. 4403 */ 4404 for (ri = 0; ri < md->pmd_npmc; ri++) { 4405 4406 /* 4407 * Pick up the pmc pointer from hardware 4408 * state similar to the CSW_OUT code. 4409 */ 4410 pm = NULL; 4411 4412 pcd = pmc_ri_to_classdep(md, ri, &adjri); 4413 4414 (void) (*pcd->pcd_get_config)(cpu, adjri, &pm); 4415 4416 PMCDBG(PRC,EXT,2, "ri=%d pm=%p", ri, pm); 4417 4418 if (pm == NULL || 4419 !PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 4420 continue; 4421 4422 PMCDBG(PRC,EXT,2, "ppmcs[%d]=%p pm=%p " 4423 "state=%d", ri, pp->pp_pmcs[ri].pp_pmc, 4424 pm, pm->pm_state); 4425 4426 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 4427 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 4428 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 4429 4430 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 4431 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", 4432 __LINE__, pm, ri, pp->pp_pmcs[ri].pp_pmc)); 4433 4434 (void) pcd->pcd_stop_pmc(cpu, adjri); 4435 4436 KASSERT(pm->pm_runcount > 0, 4437 ("[pmc,%d] bad runcount ri %d rc %d", 4438 __LINE__, ri, pm->pm_runcount)); 4439 4440 /* Stop hardware only if it is actually running */ 4441 if (pm->pm_state == PMC_STATE_RUNNING && 4442 pm->pm_stalled == 0) { 4443 pcd->pcd_read_pmc(cpu, adjri, &newvalue); 4444 tmp = newvalue - 4445 PMC_PCPU_SAVED(cpu,ri); 4446 4447 mtx_pool_lock_spin(pmc_mtxpool, pm); 4448 pm->pm_gv.pm_savedvalue += tmp; 4449 pp->pp_pmcs[ri].pp_pmcval += tmp; 4450 mtx_pool_unlock_spin(pmc_mtxpool, pm); 4451 } 4452 4453 atomic_subtract_rel_int(&pm->pm_runcount,1); 4454 4455 KASSERT((int) pm->pm_runcount >= 0, 4456 ("[pmc,%d] runcount is %d", __LINE__, ri)); 4457 4458 (void) pcd->pcd_config_pmc(cpu, adjri, NULL); 4459 } 4460 4461 /* 4462 * Inform the MD layer of this pseudo "context switch 4463 * out" 4464 */ 4465 (void) md->pmd_switch_out(pmc_pcpu[cpu], pp); 4466 4467 critical_exit(); /* ok to be pre-empted now */ 4468 4469 /* 4470 * Unlink this process from the PMCs that are 4471 * targetting it. This will send a signal to 4472 * all PMC owner's whose PMCs are orphaned. 4473 * 4474 * Log PMC value at exit time if requested. 4475 */ 4476 for (ri = 0; ri < md->pmd_npmc; ri++) 4477 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 4478 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 4479 PMC_IS_COUNTING_MODE(PMC_TO_MODE(pm))) 4480 pmclog_process_procexit(pm, pp); 4481 pmc_unlink_target_process(pm, pp); 4482 } 4483 free(pp, M_PMC); 4484 4485 } else 4486 critical_exit(); /* pp == NULL */ 4487 4488 4489 /* 4490 * If the process owned PMCs, free them up and free up 4491 * memory. 4492 */ 4493 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 4494 pmc_remove_owner(po); 4495 pmc_destroy_owner_descriptor(po); 4496 } 4497 4498 sx_xunlock(&pmc_sx); 4499 } 4500 4501 /* 4502 * Handle a process fork. 4503 * 4504 * If the parent process 'p1' is under HWPMC monitoring, then copy 4505 * over any attached PMCs that have 'do_descendants' semantics. 4506 */ 4507 4508 static void 4509 pmc_process_fork(void *arg __unused, struct proc *p1, struct proc *newproc, 4510 int flags) 4511 { 4512 int is_using_hwpmcs; 4513 unsigned int ri; 4514 uint32_t do_descendants; 4515 struct pmc *pm; 4516 struct pmc_owner *po; 4517 struct pmc_process *ppnew, *ppold; 4518 4519 (void) flags; /* unused parameter */ 4520 4521 PROC_LOCK(p1); 4522 is_using_hwpmcs = p1->p_flag & P_HWPMC; 4523 PROC_UNLOCK(p1); 4524 4525 /* 4526 * If there are system-wide sampling PMCs active, we need to 4527 * log all fork events to their owner's logs. 4528 */ 4529 4530 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4531 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4532 pmclog_process_procfork(po, p1->p_pid, newproc->p_pid); 4533 4534 if (!is_using_hwpmcs) 4535 return; 4536 4537 PMC_GET_SX_XLOCK(); 4538 PMCDBG(PMC,FRK,1, "process-fork proc=%p (%d, %s) -> %p", p1, 4539 p1->p_pid, p1->p_comm, newproc); 4540 4541 /* 4542 * If the parent process (curthread->td_proc) is a 4543 * target of any PMCs, look for PMCs that are to be 4544 * inherited, and link these into the new process 4545 * descriptor. 4546 */ 4547 if ((ppold = pmc_find_process_descriptor(curthread->td_proc, 4548 PMC_FLAG_NONE)) == NULL) 4549 goto done; /* nothing to do */ 4550 4551 do_descendants = 0; 4552 for (ri = 0; ri < md->pmd_npmc; ri++) 4553 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL) 4554 do_descendants |= pm->pm_flags & PMC_F_DESCENDANTS; 4555 if (do_descendants == 0) /* nothing to do */ 4556 goto done; 4557 4558 /* allocate a descriptor for the new process */ 4559 if ((ppnew = pmc_find_process_descriptor(newproc, 4560 PMC_FLAG_ALLOCATE)) == NULL) 4561 goto done; 4562 4563 /* 4564 * Run through all PMCs that were targeting the old process 4565 * and which specified F_DESCENDANTS and attach them to the 4566 * new process. 4567 * 4568 * Log the fork event to all owners of PMCs attached to this 4569 * process, if not already logged. 4570 */ 4571 for (ri = 0; ri < md->pmd_npmc; ri++) 4572 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL && 4573 (pm->pm_flags & PMC_F_DESCENDANTS)) { 4574 pmc_link_target_process(pm, ppnew); 4575 po = pm->pm_owner; 4576 if (po->po_sscount == 0 && 4577 po->po_flags & PMC_PO_OWNS_LOGFILE) 4578 pmclog_process_procfork(po, p1->p_pid, 4579 newproc->p_pid); 4580 } 4581 4582 /* 4583 * Now mark the new process as being tracked by this driver. 4584 */ 4585 PROC_LOCK(newproc); 4586 newproc->p_flag |= P_HWPMC; 4587 PROC_UNLOCK(newproc); 4588 4589 done: 4590 sx_xunlock(&pmc_sx); 4591 } 4592 4593 static void 4594 pmc_kld_load(void *arg __unused, linker_file_t lf) 4595 { 4596 struct pmc_owner *po; 4597 4598 sx_slock(&pmc_sx); 4599 4600 /* 4601 * Notify owners of system sampling PMCs about KLD operations. 4602 */ 4603 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4604 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4605 pmclog_process_map_in(po, (pid_t) -1, 4606 (uintfptr_t) lf->address, lf->filename); 4607 4608 /* 4609 * TODO: Notify owners of (all) process-sampling PMCs too. 4610 */ 4611 4612 sx_sunlock(&pmc_sx); 4613 } 4614 4615 static void 4616 pmc_kld_unload(void *arg __unused, const char *filename __unused, 4617 caddr_t address, size_t size) 4618 { 4619 struct pmc_owner *po; 4620 4621 sx_slock(&pmc_sx); 4622 4623 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4624 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4625 pmclog_process_map_out(po, (pid_t) -1, 4626 (uintfptr_t) address, (uintfptr_t) address + size); 4627 4628 /* 4629 * TODO: Notify owners of process-sampling PMCs. 4630 */ 4631 4632 sx_sunlock(&pmc_sx); 4633 } 4634 4635 /* 4636 * initialization 4637 */ 4638 4639 static const char *pmc_name_of_pmcclass[] = { 4640 #undef __PMC_CLASS 4641 #define __PMC_CLASS(N) #N , 4642 __PMC_CLASSES() 4643 }; 4644 4645 /* 4646 * Base class initializer: allocate structure and set default classes. 4647 */ 4648 struct pmc_mdep * 4649 pmc_mdep_alloc(int nclasses) 4650 { 4651 struct pmc_mdep *md; 4652 int n; 4653 4654 /* SOFT + md classes */ 4655 n = 1 + nclasses; 4656 md = malloc(sizeof(struct pmc_mdep) + n * 4657 sizeof(struct pmc_classdep), M_PMC, M_WAITOK|M_ZERO); 4658 md->pmd_nclass = n; 4659 4660 /* Add base class. */ 4661 pmc_soft_initialize(md); 4662 return md; 4663 } 4664 4665 void 4666 pmc_mdep_free(struct pmc_mdep *md) 4667 { 4668 pmc_soft_finalize(md); 4669 free(md, M_PMC); 4670 } 4671 4672 static int 4673 generic_switch_in(struct pmc_cpu *pc, struct pmc_process *pp) 4674 { 4675 (void) pc; (void) pp; 4676 4677 return (0); 4678 } 4679 4680 static int 4681 generic_switch_out(struct pmc_cpu *pc, struct pmc_process *pp) 4682 { 4683 (void) pc; (void) pp; 4684 4685 return (0); 4686 } 4687 4688 static struct pmc_mdep * 4689 pmc_generic_cpu_initialize(void) 4690 { 4691 struct pmc_mdep *md; 4692 4693 md = pmc_mdep_alloc(0); 4694 4695 md->pmd_cputype = PMC_CPU_GENERIC; 4696 4697 md->pmd_pcpu_init = NULL; 4698 md->pmd_pcpu_fini = NULL; 4699 md->pmd_switch_in = generic_switch_in; 4700 md->pmd_switch_out = generic_switch_out; 4701 4702 return (md); 4703 } 4704 4705 static void 4706 pmc_generic_cpu_finalize(struct pmc_mdep *md) 4707 { 4708 (void) md; 4709 } 4710 4711 4712 static int 4713 pmc_initialize(void) 4714 { 4715 int c, cpu, error, n, ri; 4716 unsigned int maxcpu; 4717 struct pmc_binding pb; 4718 struct pmc_sample *ps; 4719 struct pmc_classdep *pcd; 4720 struct pmc_samplebuffer *sb; 4721 4722 md = NULL; 4723 error = 0; 4724 4725 #ifdef DEBUG 4726 /* parse debug flags first */ 4727 if (TUNABLE_STR_FETCH(PMC_SYSCTL_NAME_PREFIX "debugflags", 4728 pmc_debugstr, sizeof(pmc_debugstr))) 4729 pmc_debugflags_parse(pmc_debugstr, 4730 pmc_debugstr+strlen(pmc_debugstr)); 4731 #endif 4732 4733 PMCDBG(MOD,INI,0, "PMC Initialize (version %x)", PMC_VERSION); 4734 4735 /* check kernel version */ 4736 if (pmc_kernel_version != PMC_VERSION) { 4737 if (pmc_kernel_version == 0) 4738 printf("hwpmc: this kernel has not been compiled with " 4739 "'options HWPMC_HOOKS'.\n"); 4740 else 4741 printf("hwpmc: kernel version (0x%x) does not match " 4742 "module version (0x%x).\n", pmc_kernel_version, 4743 PMC_VERSION); 4744 return EPROGMISMATCH; 4745 } 4746 4747 /* 4748 * check sysctl parameters 4749 */ 4750 4751 if (pmc_hashsize <= 0) { 4752 (void) printf("hwpmc: tunable \"hashsize\"=%d must be " 4753 "greater than zero.\n", pmc_hashsize); 4754 pmc_hashsize = PMC_HASH_SIZE; 4755 } 4756 4757 if (pmc_nsamples <= 0 || pmc_nsamples > 65535) { 4758 (void) printf("hwpmc: tunable \"nsamples\"=%d out of " 4759 "range.\n", pmc_nsamples); 4760 pmc_nsamples = PMC_NSAMPLES; 4761 } 4762 4763 if (pmc_callchaindepth <= 0 || 4764 pmc_callchaindepth > PMC_CALLCHAIN_DEPTH_MAX) { 4765 (void) printf("hwpmc: tunable \"callchaindepth\"=%d out of " 4766 "range.\n", pmc_callchaindepth); 4767 pmc_callchaindepth = PMC_CALLCHAIN_DEPTH; 4768 } 4769 4770 md = pmc_md_initialize(); 4771 if (md == NULL) { 4772 /* Default to generic CPU. */ 4773 md = pmc_generic_cpu_initialize(); 4774 if (md == NULL) 4775 return (ENOSYS); 4776 } 4777 4778 KASSERT(md->pmd_nclass >= 1 && md->pmd_npmc >= 1, 4779 ("[pmc,%d] no classes or pmcs", __LINE__)); 4780 4781 /* Compute the map from row-indices to classdep pointers. */ 4782 pmc_rowindex_to_classdep = malloc(sizeof(struct pmc_classdep *) * 4783 md->pmd_npmc, M_PMC, M_WAITOK|M_ZERO); 4784 4785 for (n = 0; n < md->pmd_npmc; n++) 4786 pmc_rowindex_to_classdep[n] = NULL; 4787 for (ri = c = 0; c < md->pmd_nclass; c++) { 4788 pcd = &md->pmd_classdep[c]; 4789 for (n = 0; n < pcd->pcd_num; n++, ri++) 4790 pmc_rowindex_to_classdep[ri] = pcd; 4791 } 4792 4793 KASSERT(ri == md->pmd_npmc, 4794 ("[pmc,%d] npmc miscomputed: ri=%d, md->npmc=%d", __LINE__, 4795 ri, md->pmd_npmc)); 4796 4797 maxcpu = pmc_cpu_max(); 4798 4799 /* allocate space for the per-cpu array */ 4800 pmc_pcpu = malloc(maxcpu * sizeof(struct pmc_cpu *), M_PMC, 4801 M_WAITOK|M_ZERO); 4802 4803 /* per-cpu 'saved values' for managing process-mode PMCs */ 4804 pmc_pcpu_saved = malloc(sizeof(pmc_value_t) * maxcpu * md->pmd_npmc, 4805 M_PMC, M_WAITOK); 4806 4807 /* Perform CPU-dependent initialization. */ 4808 pmc_save_cpu_binding(&pb); 4809 error = 0; 4810 for (cpu = 0; error == 0 && cpu < maxcpu; cpu++) { 4811 if (!pmc_cpu_is_active(cpu)) 4812 continue; 4813 pmc_select_cpu(cpu); 4814 pmc_pcpu[cpu] = malloc(sizeof(struct pmc_cpu) + 4815 md->pmd_npmc * sizeof(struct pmc_hw *), M_PMC, 4816 M_WAITOK|M_ZERO); 4817 if (md->pmd_pcpu_init) 4818 error = md->pmd_pcpu_init(md, cpu); 4819 for (n = 0; error == 0 && n < md->pmd_nclass; n++) 4820 error = md->pmd_classdep[n].pcd_pcpu_init(md, cpu); 4821 } 4822 pmc_restore_cpu_binding(&pb); 4823 4824 if (error) 4825 return (error); 4826 4827 /* allocate space for the sample array */ 4828 for (cpu = 0; cpu < maxcpu; cpu++) { 4829 if (!pmc_cpu_is_active(cpu)) 4830 continue; 4831 4832 sb = malloc(sizeof(struct pmc_samplebuffer) + 4833 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 4834 M_WAITOK|M_ZERO); 4835 sb->ps_read = sb->ps_write = sb->ps_samples; 4836 sb->ps_fence = sb->ps_samples + pmc_nsamples; 4837 4838 KASSERT(pmc_pcpu[cpu] != NULL, 4839 ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu)); 4840 4841 sb->ps_callchains = malloc(pmc_callchaindepth * pmc_nsamples * 4842 sizeof(uintptr_t), M_PMC, M_WAITOK|M_ZERO); 4843 4844 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 4845 ps->ps_pc = sb->ps_callchains + 4846 (n * pmc_callchaindepth); 4847 4848 pmc_pcpu[cpu]->pc_sb[PMC_HR] = sb; 4849 4850 sb = malloc(sizeof(struct pmc_samplebuffer) + 4851 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 4852 M_WAITOK|M_ZERO); 4853 sb->ps_read = sb->ps_write = sb->ps_samples; 4854 sb->ps_fence = sb->ps_samples + pmc_nsamples; 4855 4856 KASSERT(pmc_pcpu[cpu] != NULL, 4857 ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu)); 4858 4859 sb->ps_callchains = malloc(pmc_callchaindepth * pmc_nsamples * 4860 sizeof(uintptr_t), M_PMC, M_WAITOK|M_ZERO); 4861 4862 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 4863 ps->ps_pc = sb->ps_callchains + 4864 (n * pmc_callchaindepth); 4865 4866 pmc_pcpu[cpu]->pc_sb[PMC_SR] = sb; 4867 } 4868 4869 /* allocate space for the row disposition array */ 4870 pmc_pmcdisp = malloc(sizeof(enum pmc_mode) * md->pmd_npmc, 4871 M_PMC, M_WAITOK|M_ZERO); 4872 4873 /* mark all PMCs as available */ 4874 for (n = 0; n < (int) md->pmd_npmc; n++) 4875 PMC_MARK_ROW_FREE(n); 4876 4877 /* allocate thread hash tables */ 4878 pmc_ownerhash = hashinit(pmc_hashsize, M_PMC, 4879 &pmc_ownerhashmask); 4880 4881 pmc_processhash = hashinit(pmc_hashsize, M_PMC, 4882 &pmc_processhashmask); 4883 mtx_init(&pmc_processhash_mtx, "pmc-process-hash", "pmc-leaf", 4884 MTX_SPIN); 4885 4886 LIST_INIT(&pmc_ss_owners); 4887 pmc_ss_count = 0; 4888 4889 /* allocate a pool of spin mutexes */ 4890 pmc_mtxpool = mtx_pool_create("pmc-leaf", pmc_mtxpool_size, 4891 MTX_SPIN); 4892 4893 PMCDBG(MOD,INI,1, "pmc_ownerhash=%p, mask=0x%lx " 4894 "targethash=%p mask=0x%lx", pmc_ownerhash, pmc_ownerhashmask, 4895 pmc_processhash, pmc_processhashmask); 4896 4897 /* register process {exit,fork,exec} handlers */ 4898 pmc_exit_tag = EVENTHANDLER_REGISTER(process_exit, 4899 pmc_process_exit, NULL, EVENTHANDLER_PRI_ANY); 4900 pmc_fork_tag = EVENTHANDLER_REGISTER(process_fork, 4901 pmc_process_fork, NULL, EVENTHANDLER_PRI_ANY); 4902 4903 /* register kld event handlers */ 4904 pmc_kld_load_tag = EVENTHANDLER_REGISTER(kld_load, pmc_kld_load, 4905 NULL, EVENTHANDLER_PRI_ANY); 4906 pmc_kld_unload_tag = EVENTHANDLER_REGISTER(kld_unload, pmc_kld_unload, 4907 NULL, EVENTHANDLER_PRI_ANY); 4908 4909 /* initialize logging */ 4910 pmclog_initialize(); 4911 4912 /* set hook functions */ 4913 pmc_intr = md->pmd_intr; 4914 pmc_hook = pmc_hook_handler; 4915 4916 if (error == 0) { 4917 printf(PMC_MODULE_NAME ":"); 4918 for (n = 0; n < (int) md->pmd_nclass; n++) { 4919 pcd = &md->pmd_classdep[n]; 4920 printf(" %s/%d/%d/0x%b", 4921 pmc_name_of_pmcclass[pcd->pcd_class], 4922 pcd->pcd_num, 4923 pcd->pcd_width, 4924 pcd->pcd_caps, 4925 "\20" 4926 "\1INT\2USR\3SYS\4EDG\5THR" 4927 "\6REA\7WRI\10INV\11QUA\12PRC" 4928 "\13TAG\14CSC"); 4929 } 4930 printf("\n"); 4931 } 4932 4933 return (error); 4934 } 4935 4936 /* prepare to be unloaded */ 4937 static void 4938 pmc_cleanup(void) 4939 { 4940 int c, cpu; 4941 unsigned int maxcpu; 4942 struct pmc_ownerhash *ph; 4943 struct pmc_owner *po, *tmp; 4944 struct pmc_binding pb; 4945 #ifdef DEBUG 4946 struct pmc_processhash *prh; 4947 #endif 4948 4949 PMCDBG(MOD,INI,0, "%s", "cleanup"); 4950 4951 /* switch off sampling */ 4952 CPU_ZERO(&pmc_cpumask); 4953 pmc_intr = NULL; 4954 4955 sx_xlock(&pmc_sx); 4956 if (pmc_hook == NULL) { /* being unloaded already */ 4957 sx_xunlock(&pmc_sx); 4958 return; 4959 } 4960 4961 pmc_hook = NULL; /* prevent new threads from entering module */ 4962 4963 /* deregister event handlers */ 4964 EVENTHANDLER_DEREGISTER(process_fork, pmc_fork_tag); 4965 EVENTHANDLER_DEREGISTER(process_exit, pmc_exit_tag); 4966 EVENTHANDLER_DEREGISTER(kld_load, pmc_kld_load_tag); 4967 EVENTHANDLER_DEREGISTER(kld_unload, pmc_kld_unload_tag); 4968 4969 /* send SIGBUS to all owner threads, free up allocations */ 4970 if (pmc_ownerhash) 4971 for (ph = pmc_ownerhash; 4972 ph <= &pmc_ownerhash[pmc_ownerhashmask]; 4973 ph++) { 4974 LIST_FOREACH_SAFE(po, ph, po_next, tmp) { 4975 pmc_remove_owner(po); 4976 4977 /* send SIGBUS to owner processes */ 4978 PMCDBG(MOD,INI,2, "cleanup signal proc=%p " 4979 "(%d, %s)", po->po_owner, 4980 po->po_owner->p_pid, 4981 po->po_owner->p_comm); 4982 4983 PROC_LOCK(po->po_owner); 4984 kern_psignal(po->po_owner, SIGBUS); 4985 PROC_UNLOCK(po->po_owner); 4986 4987 pmc_destroy_owner_descriptor(po); 4988 } 4989 } 4990 4991 /* reclaim allocated data structures */ 4992 if (pmc_mtxpool) 4993 mtx_pool_destroy(&pmc_mtxpool); 4994 4995 mtx_destroy(&pmc_processhash_mtx); 4996 if (pmc_processhash) { 4997 #ifdef DEBUG 4998 struct pmc_process *pp; 4999 5000 PMCDBG(MOD,INI,3, "%s", "destroy process hash"); 5001 for (prh = pmc_processhash; 5002 prh <= &pmc_processhash[pmc_processhashmask]; 5003 prh++) 5004 LIST_FOREACH(pp, prh, pp_next) 5005 PMCDBG(MOD,INI,3, "pid=%d", pp->pp_proc->p_pid); 5006 #endif 5007 5008 hashdestroy(pmc_processhash, M_PMC, pmc_processhashmask); 5009 pmc_processhash = NULL; 5010 } 5011 5012 if (pmc_ownerhash) { 5013 PMCDBG(MOD,INI,3, "%s", "destroy owner hash"); 5014 hashdestroy(pmc_ownerhash, M_PMC, pmc_ownerhashmask); 5015 pmc_ownerhash = NULL; 5016 } 5017 5018 KASSERT(LIST_EMPTY(&pmc_ss_owners), 5019 ("[pmc,%d] Global SS owner list not empty", __LINE__)); 5020 KASSERT(pmc_ss_count == 0, 5021 ("[pmc,%d] Global SS count not empty", __LINE__)); 5022 5023 /* do processor and pmc-class dependent cleanup */ 5024 maxcpu = pmc_cpu_max(); 5025 5026 PMCDBG(MOD,INI,3, "%s", "md cleanup"); 5027 if (md) { 5028 pmc_save_cpu_binding(&pb); 5029 for (cpu = 0; cpu < maxcpu; cpu++) { 5030 PMCDBG(MOD,INI,1,"pmc-cleanup cpu=%d pcs=%p", 5031 cpu, pmc_pcpu[cpu]); 5032 if (!pmc_cpu_is_active(cpu) || pmc_pcpu[cpu] == NULL) 5033 continue; 5034 pmc_select_cpu(cpu); 5035 for (c = 0; c < md->pmd_nclass; c++) 5036 md->pmd_classdep[c].pcd_pcpu_fini(md, cpu); 5037 if (md->pmd_pcpu_fini) 5038 md->pmd_pcpu_fini(md, cpu); 5039 } 5040 5041 if (md->pmd_cputype == PMC_CPU_GENERIC) 5042 pmc_generic_cpu_finalize(md); 5043 else 5044 pmc_md_finalize(md); 5045 5046 pmc_mdep_free(md); 5047 md = NULL; 5048 pmc_restore_cpu_binding(&pb); 5049 } 5050 5051 /* Free per-cpu descriptors. */ 5052 for (cpu = 0; cpu < maxcpu; cpu++) { 5053 if (!pmc_cpu_is_active(cpu)) 5054 continue; 5055 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_HR] != NULL, 5056 ("[pmc,%d] Null hw cpu sample buffer cpu=%d", __LINE__, 5057 cpu)); 5058 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_SR] != NULL, 5059 ("[pmc,%d] Null sw cpu sample buffer cpu=%d", __LINE__, 5060 cpu)); 5061 free(pmc_pcpu[cpu]->pc_sb[PMC_HR]->ps_callchains, M_PMC); 5062 free(pmc_pcpu[cpu]->pc_sb[PMC_HR], M_PMC); 5063 free(pmc_pcpu[cpu]->pc_sb[PMC_SR]->ps_callchains, M_PMC); 5064 free(pmc_pcpu[cpu]->pc_sb[PMC_SR], M_PMC); 5065 free(pmc_pcpu[cpu], M_PMC); 5066 } 5067 5068 free(pmc_pcpu, M_PMC); 5069 pmc_pcpu = NULL; 5070 5071 free(pmc_pcpu_saved, M_PMC); 5072 pmc_pcpu_saved = NULL; 5073 5074 if (pmc_pmcdisp) { 5075 free(pmc_pmcdisp, M_PMC); 5076 pmc_pmcdisp = NULL; 5077 } 5078 5079 if (pmc_rowindex_to_classdep) { 5080 free(pmc_rowindex_to_classdep, M_PMC); 5081 pmc_rowindex_to_classdep = NULL; 5082 } 5083 5084 pmclog_shutdown(); 5085 5086 sx_xunlock(&pmc_sx); /* we are done */ 5087 } 5088 5089 /* 5090 * The function called at load/unload. 5091 */ 5092 5093 static int 5094 load (struct module *module __unused, int cmd, void *arg __unused) 5095 { 5096 int error; 5097 5098 error = 0; 5099 5100 switch (cmd) { 5101 case MOD_LOAD : 5102 /* initialize the subsystem */ 5103 error = pmc_initialize(); 5104 if (error != 0) 5105 break; 5106 PMCDBG(MOD,INI,1, "syscall=%d maxcpu=%d", 5107 pmc_syscall_num, pmc_cpu_max()); 5108 break; 5109 5110 5111 case MOD_UNLOAD : 5112 case MOD_SHUTDOWN: 5113 pmc_cleanup(); 5114 PMCDBG(MOD,INI,1, "%s", "unloaded"); 5115 break; 5116 5117 default : 5118 error = EINVAL; /* XXX should panic(9) */ 5119 break; 5120 } 5121 5122 return error; 5123 } 5124 5125 /* memory pool */ 5126 MALLOC_DEFINE(M_PMC, "pmc", "Memory space for the PMC module"); 5127