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/sched.h> 54 #include <sys/signalvar.h> 55 #include <sys/smp.h> 56 #include <sys/sx.h> 57 #include <sys/sysctl.h> 58 #include <sys/sysent.h> 59 #include <sys/systm.h> 60 #include <sys/vnode.h> 61 62 #include <sys/linker.h> /* needs to be after <sys/malloc.h> */ 63 64 #include <machine/atomic.h> 65 #include <machine/md_var.h> 66 67 #include <vm/vm.h> 68 #include <vm/vm_extern.h> 69 #include <vm/pmap.h> 70 #include <vm/vm_map.h> 71 #include <vm/vm_object.h> 72 73 #include "hwpmc_soft.h" 74 75 /* 76 * Types 77 */ 78 79 enum pmc_flags { 80 PMC_FLAG_NONE = 0x00, /* do nothing */ 81 PMC_FLAG_REMOVE = 0x01, /* atomically remove entry from hash */ 82 PMC_FLAG_ALLOCATE = 0x02, /* add entry to hash if not found */ 83 }; 84 85 /* 86 * The offset in sysent where the syscall is allocated. 87 */ 88 89 static int pmc_syscall_num = NO_SYSCALL; 90 struct pmc_cpu **pmc_pcpu; /* per-cpu state */ 91 pmc_value_t *pmc_pcpu_saved; /* saved PMC values: CSW handling */ 92 93 #define PMC_PCPU_SAVED(C,R) pmc_pcpu_saved[(R) + md->pmd_npmc*(C)] 94 95 struct mtx_pool *pmc_mtxpool; 96 static int *pmc_pmcdisp; /* PMC row dispositions */ 97 98 #define PMC_ROW_DISP_IS_FREE(R) (pmc_pmcdisp[(R)] == 0) 99 #define PMC_ROW_DISP_IS_THREAD(R) (pmc_pmcdisp[(R)] > 0) 100 #define PMC_ROW_DISP_IS_STANDALONE(R) (pmc_pmcdisp[(R)] < 0) 101 102 #define PMC_MARK_ROW_FREE(R) do { \ 103 pmc_pmcdisp[(R)] = 0; \ 104 } while (0) 105 106 #define PMC_MARK_ROW_STANDALONE(R) do { \ 107 KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \ 108 __LINE__)); \ 109 atomic_add_int(&pmc_pmcdisp[(R)], -1); \ 110 KASSERT(pmc_pmcdisp[(R)] >= (-pmc_cpu_max_active()), \ 111 ("[pmc,%d] row disposition error", __LINE__)); \ 112 } while (0) 113 114 #define PMC_UNMARK_ROW_STANDALONE(R) do { \ 115 atomic_add_int(&pmc_pmcdisp[(R)], 1); \ 116 KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \ 117 __LINE__)); \ 118 } while (0) 119 120 #define PMC_MARK_ROW_THREAD(R) do { \ 121 KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \ 122 __LINE__)); \ 123 atomic_add_int(&pmc_pmcdisp[(R)], 1); \ 124 } while (0) 125 126 #define PMC_UNMARK_ROW_THREAD(R) do { \ 127 atomic_add_int(&pmc_pmcdisp[(R)], -1); \ 128 KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \ 129 __LINE__)); \ 130 } while (0) 131 132 133 /* various event handlers */ 134 static eventhandler_tag pmc_exit_tag, pmc_fork_tag; 135 136 /* Module statistics */ 137 struct pmc_op_getdriverstats pmc_stats; 138 139 /* Machine/processor dependent operations */ 140 static struct pmc_mdep *md; 141 142 /* 143 * Hash tables mapping owner processes and target threads to PMCs. 144 */ 145 146 struct mtx pmc_processhash_mtx; /* spin mutex */ 147 static u_long pmc_processhashmask; 148 static LIST_HEAD(pmc_processhash, pmc_process) *pmc_processhash; 149 150 /* 151 * Hash table of PMC owner descriptors. This table is protected by 152 * the shared PMC "sx" lock. 153 */ 154 155 static u_long pmc_ownerhashmask; 156 static LIST_HEAD(pmc_ownerhash, pmc_owner) *pmc_ownerhash; 157 158 /* 159 * List of PMC owners with system-wide sampling PMCs. 160 */ 161 162 static LIST_HEAD(, pmc_owner) pmc_ss_owners; 163 164 165 /* 166 * A map of row indices to classdep structures. 167 */ 168 static struct pmc_classdep **pmc_rowindex_to_classdep; 169 170 /* 171 * Prototypes 172 */ 173 174 #ifdef DEBUG 175 static int pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS); 176 static int pmc_debugflags_parse(char *newstr, char *fence); 177 #endif 178 179 static int load(struct module *module, int cmd, void *arg); 180 static int pmc_attach_process(struct proc *p, struct pmc *pm); 181 static struct pmc *pmc_allocate_pmc_descriptor(void); 182 static struct pmc_owner *pmc_allocate_owner_descriptor(struct proc *p); 183 static int pmc_attach_one_process(struct proc *p, struct pmc *pm); 184 static int pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, 185 int cpu); 186 static int pmc_can_attach(struct pmc *pm, struct proc *p); 187 static void pmc_capture_user_callchain(int cpu, int soft, struct trapframe *tf); 188 static void pmc_cleanup(void); 189 static int pmc_detach_process(struct proc *p, struct pmc *pm); 190 static int pmc_detach_one_process(struct proc *p, struct pmc *pm, 191 int flags); 192 static void pmc_destroy_owner_descriptor(struct pmc_owner *po); 193 static struct pmc_owner *pmc_find_owner_descriptor(struct proc *p); 194 static int pmc_find_pmc(pmc_id_t pmcid, struct pmc **pm); 195 static struct pmc *pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, 196 pmc_id_t pmc); 197 static struct pmc_process *pmc_find_process_descriptor(struct proc *p, 198 uint32_t mode); 199 static void pmc_force_context_switch(void); 200 static void pmc_link_target_process(struct pmc *pm, 201 struct pmc_process *pp); 202 static void pmc_log_all_process_mappings(struct pmc_owner *po); 203 static void pmc_log_kernel_mappings(struct pmc *pm); 204 static void pmc_log_process_mappings(struct pmc_owner *po, struct proc *p); 205 static void pmc_maybe_remove_owner(struct pmc_owner *po); 206 static void pmc_process_csw_in(struct thread *td); 207 static void pmc_process_csw_out(struct thread *td); 208 static void pmc_process_exit(void *arg, struct proc *p); 209 static void pmc_process_fork(void *arg, struct proc *p1, 210 struct proc *p2, int n); 211 static void pmc_process_samples(int cpu, int soft); 212 static void pmc_release_pmc_descriptor(struct pmc *pmc); 213 static void pmc_remove_owner(struct pmc_owner *po); 214 static void pmc_remove_process_descriptor(struct pmc_process *pp); 215 static void pmc_restore_cpu_binding(struct pmc_binding *pb); 216 static void pmc_save_cpu_binding(struct pmc_binding *pb); 217 static void pmc_select_cpu(int cpu); 218 static int pmc_start(struct pmc *pm); 219 static int pmc_stop(struct pmc *pm); 220 static int pmc_syscall_handler(struct thread *td, void *syscall_args); 221 static void pmc_unlink_target_process(struct pmc *pmc, 222 struct pmc_process *pp); 223 static int generic_switch_in(struct pmc_cpu *pc, struct pmc_process *pp); 224 static int generic_switch_out(struct pmc_cpu *pc, struct pmc_process *pp); 225 static struct pmc_mdep *pmc_generic_cpu_initialize(void); 226 static void pmc_generic_cpu_finalize(struct pmc_mdep *md); 227 228 /* 229 * Kernel tunables and sysctl(8) interface. 230 */ 231 232 SYSCTL_DECL(_kern_hwpmc); 233 234 static int pmc_callchaindepth = PMC_CALLCHAIN_DEPTH; 235 TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "callchaindepth", &pmc_callchaindepth); 236 SYSCTL_INT(_kern_hwpmc, OID_AUTO, callchaindepth, CTLFLAG_TUN|CTLFLAG_RD, 237 &pmc_callchaindepth, 0, "depth of call chain records"); 238 239 #ifdef DEBUG 240 struct pmc_debugflags pmc_debugflags = PMC_DEBUG_DEFAULT_FLAGS; 241 char pmc_debugstr[PMC_DEBUG_STRSIZE]; 242 TUNABLE_STR(PMC_SYSCTL_NAME_PREFIX "debugflags", pmc_debugstr, 243 sizeof(pmc_debugstr)); 244 SYSCTL_PROC(_kern_hwpmc, OID_AUTO, debugflags, 245 CTLTYPE_STRING|CTLFLAG_RW|CTLFLAG_TUN, 246 0, 0, pmc_debugflags_sysctl_handler, "A", "debug flags"); 247 #endif 248 249 /* 250 * kern.hwpmc.hashrows -- determines the number of rows in the 251 * of the hash table used to look up threads 252 */ 253 254 static int pmc_hashsize = PMC_HASH_SIZE; 255 TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "hashsize", &pmc_hashsize); 256 SYSCTL_INT(_kern_hwpmc, OID_AUTO, hashsize, CTLFLAG_TUN|CTLFLAG_RD, 257 &pmc_hashsize, 0, "rows in hash tables"); 258 259 /* 260 * kern.hwpmc.nsamples --- number of PC samples/callchain stacks per CPU 261 */ 262 263 static int pmc_nsamples = PMC_NSAMPLES; 264 TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "nsamples", &pmc_nsamples); 265 SYSCTL_INT(_kern_hwpmc, OID_AUTO, nsamples, CTLFLAG_TUN|CTLFLAG_RD, 266 &pmc_nsamples, 0, "number of PC samples per CPU"); 267 268 269 /* 270 * kern.hwpmc.mtxpoolsize -- number of mutexes in the mutex pool. 271 */ 272 273 static int pmc_mtxpool_size = PMC_MTXPOOL_SIZE; 274 TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "mtxpoolsize", &pmc_mtxpool_size); 275 SYSCTL_INT(_kern_hwpmc, OID_AUTO, mtxpoolsize, CTLFLAG_TUN|CTLFLAG_RD, 276 &pmc_mtxpool_size, 0, "size of spin mutex pool"); 277 278 279 /* 280 * security.bsd.unprivileged_syspmcs -- allow non-root processes to 281 * allocate system-wide PMCs. 282 * 283 * Allowing unprivileged processes to allocate system PMCs is convenient 284 * if system-wide measurements need to be taken concurrently with other 285 * per-process measurements. This feature is turned off by default. 286 */ 287 288 static int pmc_unprivileged_syspmcs = 0; 289 TUNABLE_INT("security.bsd.unprivileged_syspmcs", &pmc_unprivileged_syspmcs); 290 SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_syspmcs, CTLFLAG_RW, 291 &pmc_unprivileged_syspmcs, 0, 292 "allow unprivileged process to allocate system PMCs"); 293 294 /* 295 * Hash function. Discard the lower 2 bits of the pointer since 296 * these are always zero for our uses. The hash multiplier is 297 * round((2^LONG_BIT) * ((sqrt(5)-1)/2)). 298 */ 299 300 #if LONG_BIT == 64 301 #define _PMC_HM 11400714819323198486u 302 #elif LONG_BIT == 32 303 #define _PMC_HM 2654435769u 304 #else 305 #error Must know the size of 'long' to compile 306 #endif 307 308 #define PMC_HASH_PTR(P,M) ((((unsigned long) (P) >> 2) * _PMC_HM) & (M)) 309 310 /* 311 * Syscall structures 312 */ 313 314 /* The `sysent' for the new syscall */ 315 static struct sysent pmc_sysent = { 316 2, /* sy_narg */ 317 pmc_syscall_handler /* sy_call */ 318 }; 319 320 static struct syscall_module_data pmc_syscall_mod = { 321 load, 322 NULL, 323 &pmc_syscall_num, 324 &pmc_sysent, 325 { 0, NULL } 326 }; 327 328 static moduledata_t pmc_mod = { 329 PMC_MODULE_NAME, 330 syscall_module_handler, 331 &pmc_syscall_mod 332 }; 333 334 DECLARE_MODULE(pmc, pmc_mod, SI_SUB_SMP, SI_ORDER_ANY); 335 MODULE_VERSION(pmc, PMC_VERSION); 336 337 #ifdef DEBUG 338 enum pmc_dbgparse_state { 339 PMCDS_WS, /* in whitespace */ 340 PMCDS_MAJOR, /* seen a major keyword */ 341 PMCDS_MINOR 342 }; 343 344 static int 345 pmc_debugflags_parse(char *newstr, char *fence) 346 { 347 char c, *p, *q; 348 struct pmc_debugflags *tmpflags; 349 int error, found, *newbits, tmp; 350 size_t kwlen; 351 352 tmpflags = malloc(sizeof(*tmpflags), M_PMC, M_WAITOK|M_ZERO); 353 354 p = newstr; 355 error = 0; 356 357 for (; p < fence && (c = *p); p++) { 358 359 /* skip white space */ 360 if (c == ' ' || c == '\t') 361 continue; 362 363 /* look for a keyword followed by "=" */ 364 for (q = p; p < fence && (c = *p) && c != '='; p++) 365 ; 366 if (c != '=') { 367 error = EINVAL; 368 goto done; 369 } 370 371 kwlen = p - q; 372 newbits = NULL; 373 374 /* lookup flag group name */ 375 #define DBG_SET_FLAG_MAJ(S,F) \ 376 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \ 377 newbits = &tmpflags->pdb_ ## F; 378 379 DBG_SET_FLAG_MAJ("cpu", CPU); 380 DBG_SET_FLAG_MAJ("csw", CSW); 381 DBG_SET_FLAG_MAJ("logging", LOG); 382 DBG_SET_FLAG_MAJ("module", MOD); 383 DBG_SET_FLAG_MAJ("md", MDP); 384 DBG_SET_FLAG_MAJ("owner", OWN); 385 DBG_SET_FLAG_MAJ("pmc", PMC); 386 DBG_SET_FLAG_MAJ("process", PRC); 387 DBG_SET_FLAG_MAJ("sampling", SAM); 388 389 if (newbits == NULL) { 390 error = EINVAL; 391 goto done; 392 } 393 394 p++; /* skip the '=' */ 395 396 /* Now parse the individual flags */ 397 tmp = 0; 398 newflag: 399 for (q = p; p < fence && (c = *p); p++) 400 if (c == ' ' || c == '\t' || c == ',') 401 break; 402 403 /* p == fence or c == ws or c == "," or c == 0 */ 404 405 if ((kwlen = p - q) == 0) { 406 *newbits = tmp; 407 continue; 408 } 409 410 found = 0; 411 #define DBG_SET_FLAG_MIN(S,F) \ 412 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \ 413 tmp |= found = (1 << PMC_DEBUG_MIN_ ## F) 414 415 /* a '*' denotes all possible flags in the group */ 416 if (kwlen == 1 && *q == '*') 417 tmp = found = ~0; 418 /* look for individual flag names */ 419 DBG_SET_FLAG_MIN("allocaterow", ALR); 420 DBG_SET_FLAG_MIN("allocate", ALL); 421 DBG_SET_FLAG_MIN("attach", ATT); 422 DBG_SET_FLAG_MIN("bind", BND); 423 DBG_SET_FLAG_MIN("config", CFG); 424 DBG_SET_FLAG_MIN("exec", EXC); 425 DBG_SET_FLAG_MIN("exit", EXT); 426 DBG_SET_FLAG_MIN("find", FND); 427 DBG_SET_FLAG_MIN("flush", FLS); 428 DBG_SET_FLAG_MIN("fork", FRK); 429 DBG_SET_FLAG_MIN("getbuf", GTB); 430 DBG_SET_FLAG_MIN("hook", PMH); 431 DBG_SET_FLAG_MIN("init", INI); 432 DBG_SET_FLAG_MIN("intr", INT); 433 DBG_SET_FLAG_MIN("linktarget", TLK); 434 DBG_SET_FLAG_MIN("mayberemove", OMR); 435 DBG_SET_FLAG_MIN("ops", OPS); 436 DBG_SET_FLAG_MIN("read", REA); 437 DBG_SET_FLAG_MIN("register", REG); 438 DBG_SET_FLAG_MIN("release", REL); 439 DBG_SET_FLAG_MIN("remove", ORM); 440 DBG_SET_FLAG_MIN("sample", SAM); 441 DBG_SET_FLAG_MIN("scheduleio", SIO); 442 DBG_SET_FLAG_MIN("select", SEL); 443 DBG_SET_FLAG_MIN("signal", SIG); 444 DBG_SET_FLAG_MIN("swi", SWI); 445 DBG_SET_FLAG_MIN("swo", SWO); 446 DBG_SET_FLAG_MIN("start", STA); 447 DBG_SET_FLAG_MIN("stop", STO); 448 DBG_SET_FLAG_MIN("syscall", PMS); 449 DBG_SET_FLAG_MIN("unlinktarget", TUL); 450 DBG_SET_FLAG_MIN("write", WRI); 451 if (found == 0) { 452 /* unrecognized flag name */ 453 error = EINVAL; 454 goto done; 455 } 456 457 if (c == 0 || c == ' ' || c == '\t') { /* end of flag group */ 458 *newbits = tmp; 459 continue; 460 } 461 462 p++; 463 goto newflag; 464 } 465 466 /* save the new flag set */ 467 bcopy(tmpflags, &pmc_debugflags, sizeof(pmc_debugflags)); 468 469 done: 470 free(tmpflags, M_PMC); 471 return error; 472 } 473 474 static int 475 pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS) 476 { 477 char *fence, *newstr; 478 int error; 479 unsigned int n; 480 481 (void) arg1; (void) arg2; /* unused parameters */ 482 483 n = sizeof(pmc_debugstr); 484 newstr = malloc(n, M_PMC, M_WAITOK|M_ZERO); 485 (void) strlcpy(newstr, pmc_debugstr, n); 486 487 error = sysctl_handle_string(oidp, newstr, n, req); 488 489 /* if there is a new string, parse and copy it */ 490 if (error == 0 && req->newptr != NULL) { 491 fence = newstr + (n < req->newlen ? n : req->newlen + 1); 492 if ((error = pmc_debugflags_parse(newstr, fence)) == 0) 493 (void) strlcpy(pmc_debugstr, newstr, 494 sizeof(pmc_debugstr)); 495 } 496 497 free(newstr, M_PMC); 498 499 return error; 500 } 501 #endif 502 503 /* 504 * Map a row index to a classdep structure and return the adjusted row 505 * index for the PMC class index. 506 */ 507 static struct pmc_classdep * 508 pmc_ri_to_classdep(struct pmc_mdep *md, int ri, int *adjri) 509 { 510 struct pmc_classdep *pcd; 511 512 (void) md; 513 514 KASSERT(ri >= 0 && ri < md->pmd_npmc, 515 ("[pmc,%d] illegal row-index %d", __LINE__, ri)); 516 517 pcd = pmc_rowindex_to_classdep[ri]; 518 519 KASSERT(pcd != NULL, 520 ("[pmc,%d] ri %d null pcd", __LINE__, ri)); 521 522 *adjri = ri - pcd->pcd_ri; 523 524 KASSERT(*adjri >= 0 && *adjri < pcd->pcd_num, 525 ("[pmc,%d] adjusted row-index %d", __LINE__, *adjri)); 526 527 return (pcd); 528 } 529 530 /* 531 * Concurrency Control 532 * 533 * The driver manages the following data structures: 534 * 535 * - target process descriptors, one per target process 536 * - owner process descriptors (and attached lists), one per owner process 537 * - lookup hash tables for owner and target processes 538 * - PMC descriptors (and attached lists) 539 * - per-cpu hardware state 540 * - the 'hook' variable through which the kernel calls into 541 * this module 542 * - the machine hardware state (managed by the MD layer) 543 * 544 * These data structures are accessed from: 545 * 546 * - thread context-switch code 547 * - interrupt handlers (possibly on multiple cpus) 548 * - kernel threads on multiple cpus running on behalf of user 549 * processes doing system calls 550 * - this driver's private kernel threads 551 * 552 * = Locks and Locking strategy = 553 * 554 * The driver uses four locking strategies for its operation: 555 * 556 * - The global SX lock "pmc_sx" is used to protect internal 557 * data structures. 558 * 559 * Calls into the module by syscall() start with this lock being 560 * held in exclusive mode. Depending on the requested operation, 561 * the lock may be downgraded to 'shared' mode to allow more 562 * concurrent readers into the module. Calls into the module from 563 * other parts of the kernel acquire the lock in shared mode. 564 * 565 * This SX lock is held in exclusive mode for any operations that 566 * modify the linkages between the driver's internal data structures. 567 * 568 * The 'pmc_hook' function pointer is also protected by this lock. 569 * It is only examined with the sx lock held in exclusive mode. The 570 * kernel module is allowed to be unloaded only with the sx lock held 571 * in exclusive mode. In normal syscall handling, after acquiring the 572 * pmc_sx lock we first check that 'pmc_hook' is non-null before 573 * proceeding. This prevents races between the thread unloading the module 574 * and other threads seeking to use the module. 575 * 576 * - Lookups of target process structures and owner process structures 577 * cannot use the global "pmc_sx" SX lock because these lookups need 578 * to happen during context switches and in other critical sections 579 * where sleeping is not allowed. We protect these lookup tables 580 * with their own private spin-mutexes, "pmc_processhash_mtx" and 581 * "pmc_ownerhash_mtx". 582 * 583 * - Interrupt handlers work in a lock free manner. At interrupt 584 * time, handlers look at the PMC pointer (phw->phw_pmc) configured 585 * when the PMC was started. If this pointer is NULL, the interrupt 586 * is ignored after updating driver statistics. We ensure that this 587 * pointer is set (using an atomic operation if necessary) before the 588 * PMC hardware is started. Conversely, this pointer is unset atomically 589 * only after the PMC hardware is stopped. 590 * 591 * We ensure that everything needed for the operation of an 592 * interrupt handler is available without it needing to acquire any 593 * locks. We also ensure that a PMC's software state is destroyed only 594 * after the PMC is taken off hardware (on all CPUs). 595 * 596 * - Context-switch handling with process-private PMCs needs more 597 * care. 598 * 599 * A given process may be the target of multiple PMCs. For example, 600 * PMCATTACH and PMCDETACH may be requested by a process on one CPU 601 * while the target process is running on another. A PMC could also 602 * be getting released because its owner is exiting. We tackle 603 * these situations in the following manner: 604 * 605 * - each target process structure 'pmc_process' has an array 606 * of 'struct pmc *' pointers, one for each hardware PMC. 607 * 608 * - At context switch IN time, each "target" PMC in RUNNING state 609 * gets started on hardware and a pointer to each PMC is copied into 610 * the per-cpu phw array. The 'runcount' for the PMC is 611 * incremented. 612 * 613 * - At context switch OUT time, all process-virtual PMCs are stopped 614 * on hardware. The saved value is added to the PMCs value field 615 * only if the PMC is in a non-deleted state (the PMCs state could 616 * have changed during the current time slice). 617 * 618 * Note that since in-between a switch IN on a processor and a switch 619 * OUT, the PMC could have been released on another CPU. Therefore 620 * context switch OUT always looks at the hardware state to turn 621 * OFF PMCs and will update a PMC's saved value only if reachable 622 * from the target process record. 623 * 624 * - OP PMCRELEASE could be called on a PMC at any time (the PMC could 625 * be attached to many processes at the time of the call and could 626 * be active on multiple CPUs). 627 * 628 * We prevent further scheduling of the PMC by marking it as in 629 * state 'DELETED'. If the runcount of the PMC is non-zero then 630 * this PMC is currently running on a CPU somewhere. The thread 631 * doing the PMCRELEASE operation waits by repeatedly doing a 632 * pause() till the runcount comes to zero. 633 * 634 * The contents of a PMC descriptor (struct pmc) are protected using 635 * a spin-mutex. In order to save space, we use a mutex pool. 636 * 637 * In terms of lock types used by witness(4), we use: 638 * - Type "pmc-sx", used by the global SX lock. 639 * - Type "pmc-sleep", for sleep mutexes used by logger threads. 640 * - Type "pmc-per-proc", for protecting PMC owner descriptors. 641 * - Type "pmc-leaf", used for all other spin mutexes. 642 */ 643 644 /* 645 * save the cpu binding of the current kthread 646 */ 647 648 static void 649 pmc_save_cpu_binding(struct pmc_binding *pb) 650 { 651 PMCDBG(CPU,BND,2, "%s", "save-cpu"); 652 thread_lock(curthread); 653 pb->pb_bound = sched_is_bound(curthread); 654 pb->pb_cpu = curthread->td_oncpu; 655 thread_unlock(curthread); 656 PMCDBG(CPU,BND,2, "save-cpu cpu=%d", pb->pb_cpu); 657 } 658 659 /* 660 * restore the cpu binding of the current thread 661 */ 662 663 static void 664 pmc_restore_cpu_binding(struct pmc_binding *pb) 665 { 666 PMCDBG(CPU,BND,2, "restore-cpu curcpu=%d restore=%d", 667 curthread->td_oncpu, pb->pb_cpu); 668 thread_lock(curthread); 669 if (pb->pb_bound) 670 sched_bind(curthread, pb->pb_cpu); 671 else 672 sched_unbind(curthread); 673 thread_unlock(curthread); 674 PMCDBG(CPU,BND,2, "%s", "restore-cpu done"); 675 } 676 677 /* 678 * move execution over the specified cpu and bind it there. 679 */ 680 681 static void 682 pmc_select_cpu(int cpu) 683 { 684 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 685 ("[pmc,%d] bad cpu number %d", __LINE__, cpu)); 686 687 /* Never move to an inactive CPU. */ 688 KASSERT(pmc_cpu_is_active(cpu), ("[pmc,%d] selecting inactive " 689 "CPU %d", __LINE__, cpu)); 690 691 PMCDBG(CPU,SEL,2, "select-cpu cpu=%d", cpu); 692 thread_lock(curthread); 693 sched_bind(curthread, cpu); 694 thread_unlock(curthread); 695 696 KASSERT(curthread->td_oncpu == cpu, 697 ("[pmc,%d] CPU not bound [cpu=%d, curr=%d]", __LINE__, 698 cpu, curthread->td_oncpu)); 699 700 PMCDBG(CPU,SEL,2, "select-cpu cpu=%d ok", cpu); 701 } 702 703 /* 704 * Force a context switch. 705 * 706 * We do this by pause'ing for 1 tick -- invoking mi_switch() is not 707 * guaranteed to force a context switch. 708 */ 709 710 static void 711 pmc_force_context_switch(void) 712 { 713 714 pause("pmcctx", 1); 715 } 716 717 /* 718 * Get the file name for an executable. This is a simple wrapper 719 * around vn_fullpath(9). 720 */ 721 722 static void 723 pmc_getfilename(struct vnode *v, char **fullpath, char **freepath) 724 { 725 726 *fullpath = "unknown"; 727 *freepath = NULL; 728 vn_fullpath(curthread, v, fullpath, freepath); 729 } 730 731 /* 732 * remove an process owning PMCs 733 */ 734 735 void 736 pmc_remove_owner(struct pmc_owner *po) 737 { 738 struct pmc *pm, *tmp; 739 740 sx_assert(&pmc_sx, SX_XLOCKED); 741 742 PMCDBG(OWN,ORM,1, "remove-owner po=%p", po); 743 744 /* Remove descriptor from the owner hash table */ 745 LIST_REMOVE(po, po_next); 746 747 /* release all owned PMC descriptors */ 748 LIST_FOREACH_SAFE(pm, &po->po_pmcs, pm_next, tmp) { 749 PMCDBG(OWN,ORM,2, "pmc=%p", pm); 750 KASSERT(pm->pm_owner == po, 751 ("[pmc,%d] owner %p != po %p", __LINE__, pm->pm_owner, po)); 752 753 pmc_release_pmc_descriptor(pm); /* will unlink from the list */ 754 } 755 756 KASSERT(po->po_sscount == 0, 757 ("[pmc,%d] SS count not zero", __LINE__)); 758 KASSERT(LIST_EMPTY(&po->po_pmcs), 759 ("[pmc,%d] PMC list not empty", __LINE__)); 760 761 /* de-configure the log file if present */ 762 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 763 pmclog_deconfigure_log(po); 764 } 765 766 /* 767 * remove an owner process record if all conditions are met. 768 */ 769 770 static void 771 pmc_maybe_remove_owner(struct pmc_owner *po) 772 { 773 774 PMCDBG(OWN,OMR,1, "maybe-remove-owner po=%p", po); 775 776 /* 777 * Remove owner record if 778 * - this process does not own any PMCs 779 * - this process has not allocated a system-wide sampling buffer 780 */ 781 782 if (LIST_EMPTY(&po->po_pmcs) && 783 ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0)) { 784 pmc_remove_owner(po); 785 pmc_destroy_owner_descriptor(po); 786 } 787 } 788 789 /* 790 * Add an association between a target process and a PMC. 791 */ 792 793 static void 794 pmc_link_target_process(struct pmc *pm, struct pmc_process *pp) 795 { 796 int ri; 797 struct pmc_target *pt; 798 799 sx_assert(&pmc_sx, SX_XLOCKED); 800 801 KASSERT(pm != NULL && pp != NULL, 802 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 803 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 804 ("[pmc,%d] Attaching a non-process-virtual pmc=%p to pid=%d", 805 __LINE__, pm, pp->pp_proc->p_pid)); 806 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= ((int) md->pmd_npmc - 1), 807 ("[pmc,%d] Illegal reference count %d for process record %p", 808 __LINE__, pp->pp_refcnt, (void *) pp)); 809 810 ri = PMC_TO_ROWINDEX(pm); 811 812 PMCDBG(PRC,TLK,1, "link-target pmc=%p ri=%d pmc-process=%p", 813 pm, ri, pp); 814 815 #ifdef DEBUG 816 LIST_FOREACH(pt, &pm->pm_targets, pt_next) 817 if (pt->pt_process == pp) 818 KASSERT(0, ("[pmc,%d] pp %p already in pmc %p targets", 819 __LINE__, pp, pm)); 820 #endif 821 822 pt = malloc(sizeof(struct pmc_target), M_PMC, M_WAITOK|M_ZERO); 823 pt->pt_process = pp; 824 825 LIST_INSERT_HEAD(&pm->pm_targets, pt, pt_next); 826 827 atomic_store_rel_ptr((uintptr_t *)&pp->pp_pmcs[ri].pp_pmc, 828 (uintptr_t)pm); 829 830 if (pm->pm_owner->po_owner == pp->pp_proc) 831 pm->pm_flags |= PMC_F_ATTACHED_TO_OWNER; 832 833 /* 834 * Initialize the per-process values at this row index. 835 */ 836 pp->pp_pmcs[ri].pp_pmcval = PMC_TO_MODE(pm) == PMC_MODE_TS ? 837 pm->pm_sc.pm_reloadcount : 0; 838 839 pp->pp_refcnt++; 840 841 } 842 843 /* 844 * Removes the association between a target process and a PMC. 845 */ 846 847 static void 848 pmc_unlink_target_process(struct pmc *pm, struct pmc_process *pp) 849 { 850 int ri; 851 struct proc *p; 852 struct pmc_target *ptgt; 853 854 sx_assert(&pmc_sx, SX_XLOCKED); 855 856 KASSERT(pm != NULL && pp != NULL, 857 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 858 859 KASSERT(pp->pp_refcnt >= 1 && pp->pp_refcnt <= (int) md->pmd_npmc, 860 ("[pmc,%d] Illegal ref count %d on process record %p", 861 __LINE__, pp->pp_refcnt, (void *) pp)); 862 863 ri = PMC_TO_ROWINDEX(pm); 864 865 PMCDBG(PRC,TUL,1, "unlink-target pmc=%p ri=%d pmc-process=%p", 866 pm, ri, pp); 867 868 KASSERT(pp->pp_pmcs[ri].pp_pmc == pm, 869 ("[pmc,%d] PMC ri %d mismatch pmc %p pp->[ri] %p", __LINE__, 870 ri, pm, pp->pp_pmcs[ri].pp_pmc)); 871 872 pp->pp_pmcs[ri].pp_pmc = NULL; 873 pp->pp_pmcs[ri].pp_pmcval = (pmc_value_t) 0; 874 875 /* Remove owner-specific flags */ 876 if (pm->pm_owner->po_owner == pp->pp_proc) { 877 pp->pp_flags &= ~PMC_PP_ENABLE_MSR_ACCESS; 878 pm->pm_flags &= ~PMC_F_ATTACHED_TO_OWNER; 879 } 880 881 pp->pp_refcnt--; 882 883 /* Remove the target process from the PMC structure */ 884 LIST_FOREACH(ptgt, &pm->pm_targets, pt_next) 885 if (ptgt->pt_process == pp) 886 break; 887 888 KASSERT(ptgt != NULL, ("[pmc,%d] process %p (pp: %p) not found " 889 "in pmc %p", __LINE__, pp->pp_proc, pp, pm)); 890 891 LIST_REMOVE(ptgt, pt_next); 892 free(ptgt, M_PMC); 893 894 /* if the PMC now lacks targets, send the owner a SIGIO */ 895 if (LIST_EMPTY(&pm->pm_targets)) { 896 p = pm->pm_owner->po_owner; 897 PROC_LOCK(p); 898 kern_psignal(p, SIGIO); 899 PROC_UNLOCK(p); 900 901 PMCDBG(PRC,SIG,2, "signalling proc=%p signal=%d", p, 902 SIGIO); 903 } 904 } 905 906 /* 907 * Check if PMC 'pm' may be attached to target process 't'. 908 */ 909 910 static int 911 pmc_can_attach(struct pmc *pm, struct proc *t) 912 { 913 struct proc *o; /* pmc owner */ 914 struct ucred *oc, *tc; /* owner, target credentials */ 915 int decline_attach, i; 916 917 /* 918 * A PMC's owner can always attach that PMC to itself. 919 */ 920 921 if ((o = pm->pm_owner->po_owner) == t) 922 return 0; 923 924 PROC_LOCK(o); 925 oc = o->p_ucred; 926 crhold(oc); 927 PROC_UNLOCK(o); 928 929 PROC_LOCK(t); 930 tc = t->p_ucred; 931 crhold(tc); 932 PROC_UNLOCK(t); 933 934 /* 935 * The effective uid of the PMC owner should match at least one 936 * of the {effective,real,saved} uids of the target process. 937 */ 938 939 decline_attach = oc->cr_uid != tc->cr_uid && 940 oc->cr_uid != tc->cr_svuid && 941 oc->cr_uid != tc->cr_ruid; 942 943 /* 944 * Every one of the target's group ids, must be in the owner's 945 * group list. 946 */ 947 for (i = 0; !decline_attach && i < tc->cr_ngroups; i++) 948 decline_attach = !groupmember(tc->cr_groups[i], oc); 949 950 /* check the read and saved gids too */ 951 if (decline_attach == 0) 952 decline_attach = !groupmember(tc->cr_rgid, oc) || 953 !groupmember(tc->cr_svgid, oc); 954 955 crfree(tc); 956 crfree(oc); 957 958 return !decline_attach; 959 } 960 961 /* 962 * Attach a process to a PMC. 963 */ 964 965 static int 966 pmc_attach_one_process(struct proc *p, struct pmc *pm) 967 { 968 int ri; 969 char *fullpath, *freepath; 970 struct pmc_process *pp; 971 972 sx_assert(&pmc_sx, SX_XLOCKED); 973 974 PMCDBG(PRC,ATT,2, "attach-one pm=%p ri=%d proc=%p (%d, %s)", pm, 975 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 976 977 /* 978 * Locate the process descriptor corresponding to process 'p', 979 * allocating space as needed. 980 * 981 * Verify that rowindex 'pm_rowindex' is free in the process 982 * descriptor. 983 * 984 * If not, allocate space for a descriptor and link the 985 * process descriptor and PMC. 986 */ 987 ri = PMC_TO_ROWINDEX(pm); 988 989 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_ALLOCATE)) == NULL) 990 return ENOMEM; 991 992 if (pp->pp_pmcs[ri].pp_pmc == pm) /* already present at slot [ri] */ 993 return EEXIST; 994 995 if (pp->pp_pmcs[ri].pp_pmc != NULL) 996 return EBUSY; 997 998 pmc_link_target_process(pm, pp); 999 1000 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) && 1001 (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) == 0) 1002 pm->pm_flags |= PMC_F_NEEDS_LOGFILE; 1003 1004 pm->pm_flags |= PMC_F_ATTACH_DONE; /* mark as attached */ 1005 1006 /* issue an attach event to a configured log file */ 1007 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) { 1008 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 1009 if (p->p_flag & P_KTHREAD) { 1010 fullpath = kernelname; 1011 freepath = NULL; 1012 } else 1013 pmclog_process_pmcattach(pm, p->p_pid, fullpath); 1014 if (freepath) 1015 free(freepath, M_TEMP); 1016 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1017 pmc_log_process_mappings(pm->pm_owner, p); 1018 } 1019 /* mark process as using HWPMCs */ 1020 PROC_LOCK(p); 1021 p->p_flag |= P_HWPMC; 1022 PROC_UNLOCK(p); 1023 1024 return 0; 1025 } 1026 1027 /* 1028 * Attach a process and optionally its children 1029 */ 1030 1031 static int 1032 pmc_attach_process(struct proc *p, struct pmc *pm) 1033 { 1034 int error; 1035 struct proc *top; 1036 1037 sx_assert(&pmc_sx, SX_XLOCKED); 1038 1039 PMCDBG(PRC,ATT,1, "attach pm=%p ri=%d proc=%p (%d, %s)", pm, 1040 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1041 1042 1043 /* 1044 * If this PMC successfully allowed a GETMSR operation 1045 * in the past, disallow further ATTACHes. 1046 */ 1047 1048 if ((pm->pm_flags & PMC_PP_ENABLE_MSR_ACCESS) != 0) 1049 return EPERM; 1050 1051 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 1052 return pmc_attach_one_process(p, pm); 1053 1054 /* 1055 * Traverse all child processes, attaching them to 1056 * this PMC. 1057 */ 1058 1059 sx_slock(&proctree_lock); 1060 1061 top = p; 1062 1063 for (;;) { 1064 if ((error = pmc_attach_one_process(p, pm)) != 0) 1065 break; 1066 if (!LIST_EMPTY(&p->p_children)) 1067 p = LIST_FIRST(&p->p_children); 1068 else for (;;) { 1069 if (p == top) 1070 goto done; 1071 if (LIST_NEXT(p, p_sibling)) { 1072 p = LIST_NEXT(p, p_sibling); 1073 break; 1074 } 1075 p = p->p_pptr; 1076 } 1077 } 1078 1079 if (error) 1080 (void) pmc_detach_process(top, pm); 1081 1082 done: 1083 sx_sunlock(&proctree_lock); 1084 return error; 1085 } 1086 1087 /* 1088 * Detach a process from a PMC. If there are no other PMCs tracking 1089 * this process, remove the process structure from its hash table. If 1090 * 'flags' contains PMC_FLAG_REMOVE, then free the process structure. 1091 */ 1092 1093 static int 1094 pmc_detach_one_process(struct proc *p, struct pmc *pm, int flags) 1095 { 1096 int ri; 1097 struct pmc_process *pp; 1098 1099 sx_assert(&pmc_sx, SX_XLOCKED); 1100 1101 KASSERT(pm != NULL, 1102 ("[pmc,%d] null pm pointer", __LINE__)); 1103 1104 ri = PMC_TO_ROWINDEX(pm); 1105 1106 PMCDBG(PRC,ATT,2, "detach-one pm=%p ri=%d proc=%p (%d, %s) flags=0x%x", 1107 pm, ri, p, p->p_pid, p->p_comm, flags); 1108 1109 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) 1110 return ESRCH; 1111 1112 if (pp->pp_pmcs[ri].pp_pmc != pm) 1113 return EINVAL; 1114 1115 pmc_unlink_target_process(pm, pp); 1116 1117 /* Issue a detach entry if a log file is configured */ 1118 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) 1119 pmclog_process_pmcdetach(pm, p->p_pid); 1120 1121 /* 1122 * If there are no PMCs targetting this process, we remove its 1123 * descriptor from the target hash table and unset the P_HWPMC 1124 * flag in the struct proc. 1125 */ 1126 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= (int) md->pmd_npmc, 1127 ("[pmc,%d] Illegal refcnt %d for process struct %p", 1128 __LINE__, pp->pp_refcnt, pp)); 1129 1130 if (pp->pp_refcnt != 0) /* still a target of some PMC */ 1131 return 0; 1132 1133 pmc_remove_process_descriptor(pp); 1134 1135 if (flags & PMC_FLAG_REMOVE) 1136 free(pp, M_PMC); 1137 1138 PROC_LOCK(p); 1139 p->p_flag &= ~P_HWPMC; 1140 PROC_UNLOCK(p); 1141 1142 return 0; 1143 } 1144 1145 /* 1146 * Detach a process and optionally its descendants from a PMC. 1147 */ 1148 1149 static int 1150 pmc_detach_process(struct proc *p, struct pmc *pm) 1151 { 1152 struct proc *top; 1153 1154 sx_assert(&pmc_sx, SX_XLOCKED); 1155 1156 PMCDBG(PRC,ATT,1, "detach pm=%p ri=%d proc=%p (%d, %s)", pm, 1157 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1158 1159 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 1160 return pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); 1161 1162 /* 1163 * Traverse all children, detaching them from this PMC. We 1164 * ignore errors since we could be detaching a PMC from a 1165 * partially attached proc tree. 1166 */ 1167 1168 sx_slock(&proctree_lock); 1169 1170 top = p; 1171 1172 for (;;) { 1173 (void) pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); 1174 1175 if (!LIST_EMPTY(&p->p_children)) 1176 p = LIST_FIRST(&p->p_children); 1177 else for (;;) { 1178 if (p == top) 1179 goto done; 1180 if (LIST_NEXT(p, p_sibling)) { 1181 p = LIST_NEXT(p, p_sibling); 1182 break; 1183 } 1184 p = p->p_pptr; 1185 } 1186 } 1187 1188 done: 1189 sx_sunlock(&proctree_lock); 1190 1191 if (LIST_EMPTY(&pm->pm_targets)) 1192 pm->pm_flags &= ~PMC_F_ATTACH_DONE; 1193 1194 return 0; 1195 } 1196 1197 1198 /* 1199 * Thread context switch IN 1200 */ 1201 1202 static void 1203 pmc_process_csw_in(struct thread *td) 1204 { 1205 int cpu; 1206 unsigned int adjri, ri; 1207 struct pmc *pm; 1208 struct proc *p; 1209 struct pmc_cpu *pc; 1210 struct pmc_hw *phw; 1211 pmc_value_t newvalue; 1212 struct pmc_process *pp; 1213 struct pmc_classdep *pcd; 1214 1215 p = td->td_proc; 1216 1217 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE)) == NULL) 1218 return; 1219 1220 KASSERT(pp->pp_proc == td->td_proc, 1221 ("[pmc,%d] not my thread state", __LINE__)); 1222 1223 critical_enter(); /* no preemption from this point */ 1224 1225 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1226 1227 PMCDBG(CSW,SWI,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1228 p->p_pid, p->p_comm, pp); 1229 1230 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 1231 ("[pmc,%d] wierd CPU id %d", __LINE__, cpu)); 1232 1233 pc = pmc_pcpu[cpu]; 1234 1235 for (ri = 0; ri < md->pmd_npmc; ri++) { 1236 1237 if ((pm = pp->pp_pmcs[ri].pp_pmc) == NULL) 1238 continue; 1239 1240 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 1241 ("[pmc,%d] Target PMC in non-virtual mode (%d)", 1242 __LINE__, PMC_TO_MODE(pm))); 1243 1244 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1245 ("[pmc,%d] Row index mismatch pmc %d != ri %d", 1246 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1247 1248 /* 1249 * Only PMCs that are marked as 'RUNNING' need 1250 * be placed on hardware. 1251 */ 1252 1253 if (pm->pm_state != PMC_STATE_RUNNING) 1254 continue; 1255 1256 /* increment PMC runcount */ 1257 atomic_add_rel_int(&pm->pm_runcount, 1); 1258 1259 /* configure the HWPMC we are going to use. */ 1260 pcd = pmc_ri_to_classdep(md, ri, &adjri); 1261 pcd->pcd_config_pmc(cpu, adjri, pm); 1262 1263 phw = pc->pc_hwpmcs[ri]; 1264 1265 KASSERT(phw != NULL, 1266 ("[pmc,%d] null hw pointer", __LINE__)); 1267 1268 KASSERT(phw->phw_pmc == pm, 1269 ("[pmc,%d] hw->pmc %p != pmc %p", __LINE__, 1270 phw->phw_pmc, pm)); 1271 1272 /* 1273 * Write out saved value and start the PMC. 1274 * 1275 * Sampling PMCs use a per-process value, while 1276 * counting mode PMCs use a per-pmc value that is 1277 * inherited across descendants. 1278 */ 1279 if (PMC_TO_MODE(pm) == PMC_MODE_TS) { 1280 mtx_pool_lock_spin(pmc_mtxpool, pm); 1281 newvalue = PMC_PCPU_SAVED(cpu,ri) = 1282 pp->pp_pmcs[ri].pp_pmcval; 1283 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1284 } else { 1285 KASSERT(PMC_TO_MODE(pm) == PMC_MODE_TC, 1286 ("[pmc,%d] illegal mode=%d", __LINE__, 1287 PMC_TO_MODE(pm))); 1288 mtx_pool_lock_spin(pmc_mtxpool, pm); 1289 newvalue = PMC_PCPU_SAVED(cpu, ri) = 1290 pm->pm_gv.pm_savedvalue; 1291 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1292 } 1293 1294 PMCDBG(CSW,SWI,1,"cpu=%d ri=%d new=%jd", cpu, ri, newvalue); 1295 1296 pcd->pcd_write_pmc(cpu, adjri, newvalue); 1297 pcd->pcd_start_pmc(cpu, adjri); 1298 } 1299 1300 /* 1301 * perform any other architecture/cpu dependent thread 1302 * switch-in actions. 1303 */ 1304 1305 (void) (*md->pmd_switch_in)(pc, pp); 1306 1307 critical_exit(); 1308 1309 } 1310 1311 /* 1312 * Thread context switch OUT. 1313 */ 1314 1315 static void 1316 pmc_process_csw_out(struct thread *td) 1317 { 1318 int cpu; 1319 int64_t tmp; 1320 struct pmc *pm; 1321 struct proc *p; 1322 enum pmc_mode mode; 1323 struct pmc_cpu *pc; 1324 pmc_value_t newvalue; 1325 unsigned int adjri, ri; 1326 struct pmc_process *pp; 1327 struct pmc_classdep *pcd; 1328 1329 1330 /* 1331 * Locate our process descriptor; this may be NULL if 1332 * this process is exiting and we have already removed 1333 * the process from the target process table. 1334 * 1335 * Note that due to kernel preemption, multiple 1336 * context switches may happen while the process is 1337 * exiting. 1338 * 1339 * Note also that if the target process cannot be 1340 * found we still need to deconfigure any PMCs that 1341 * are currently running on hardware. 1342 */ 1343 1344 p = td->td_proc; 1345 pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE); 1346 1347 /* 1348 * save PMCs 1349 */ 1350 1351 critical_enter(); 1352 1353 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1354 1355 PMCDBG(CSW,SWO,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1356 p->p_pid, p->p_comm, pp); 1357 1358 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 1359 ("[pmc,%d wierd CPU id %d", __LINE__, cpu)); 1360 1361 pc = pmc_pcpu[cpu]; 1362 1363 /* 1364 * When a PMC gets unlinked from a target PMC, it will 1365 * be removed from the target's pp_pmc[] array. 1366 * 1367 * However, on a MP system, the target could have been 1368 * executing on another CPU at the time of the unlink. 1369 * So, at context switch OUT time, we need to look at 1370 * the hardware to determine if a PMC is scheduled on 1371 * it. 1372 */ 1373 1374 for (ri = 0; ri < md->pmd_npmc; ri++) { 1375 1376 pcd = pmc_ri_to_classdep(md, ri, &adjri); 1377 pm = NULL; 1378 (void) (*pcd->pcd_get_config)(cpu, adjri, &pm); 1379 1380 if (pm == NULL) /* nothing at this row index */ 1381 continue; 1382 1383 mode = PMC_TO_MODE(pm); 1384 if (!PMC_IS_VIRTUAL_MODE(mode)) 1385 continue; /* not a process virtual PMC */ 1386 1387 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1388 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 1389 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1390 1391 /* Stop hardware if not already stopped */ 1392 if (pm->pm_stalled == 0) 1393 pcd->pcd_stop_pmc(cpu, adjri); 1394 1395 /* reduce this PMC's runcount */ 1396 atomic_subtract_rel_int(&pm->pm_runcount, 1); 1397 1398 /* 1399 * If this PMC is associated with this process, 1400 * save the reading. 1401 */ 1402 1403 if (pp != NULL && pp->pp_pmcs[ri].pp_pmc != NULL) { 1404 1405 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 1406 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", __LINE__, 1407 pm, ri, pp->pp_pmcs[ri].pp_pmc)); 1408 1409 KASSERT(pp->pp_refcnt > 0, 1410 ("[pmc,%d] pp refcnt = %d", __LINE__, 1411 pp->pp_refcnt)); 1412 1413 pcd->pcd_read_pmc(cpu, adjri, &newvalue); 1414 1415 tmp = newvalue - PMC_PCPU_SAVED(cpu,ri); 1416 1417 PMCDBG(CSW,SWO,1,"cpu=%d ri=%d tmp=%jd", cpu, ri, 1418 tmp); 1419 1420 if (mode == PMC_MODE_TS) { 1421 1422 /* 1423 * For sampling process-virtual PMCs, 1424 * we expect the count to be 1425 * decreasing as the 'value' 1426 * programmed into the PMC is the 1427 * number of events to be seen till 1428 * the next sampling interrupt. 1429 */ 1430 if (tmp < 0) 1431 tmp += pm->pm_sc.pm_reloadcount; 1432 mtx_pool_lock_spin(pmc_mtxpool, pm); 1433 pp->pp_pmcs[ri].pp_pmcval -= tmp; 1434 if ((int64_t) pp->pp_pmcs[ri].pp_pmcval < 0) 1435 pp->pp_pmcs[ri].pp_pmcval += 1436 pm->pm_sc.pm_reloadcount; 1437 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1438 1439 } else { 1440 1441 /* 1442 * For counting process-virtual PMCs, 1443 * we expect the count to be 1444 * increasing monotonically, modulo a 64 1445 * bit wraparound. 1446 */ 1447 KASSERT((int64_t) tmp >= 0, 1448 ("[pmc,%d] negative increment cpu=%d " 1449 "ri=%d newvalue=%jx saved=%jx " 1450 "incr=%jx", __LINE__, cpu, ri, 1451 newvalue, PMC_PCPU_SAVED(cpu,ri), tmp)); 1452 1453 mtx_pool_lock_spin(pmc_mtxpool, pm); 1454 pm->pm_gv.pm_savedvalue += tmp; 1455 pp->pp_pmcs[ri].pp_pmcval += tmp; 1456 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1457 1458 if (pm->pm_flags & PMC_F_LOG_PROCCSW) 1459 pmclog_process_proccsw(pm, pp, tmp); 1460 } 1461 } 1462 1463 /* mark hardware as free */ 1464 pcd->pcd_config_pmc(cpu, adjri, NULL); 1465 } 1466 1467 /* 1468 * perform any other architecture/cpu dependent thread 1469 * switch out functions. 1470 */ 1471 1472 (void) (*md->pmd_switch_out)(pc, pp); 1473 1474 critical_exit(); 1475 } 1476 1477 /* 1478 * Log a KLD operation. 1479 */ 1480 1481 static void 1482 pmc_process_kld_load(struct pmckern_map_in *pkm) 1483 { 1484 struct pmc_owner *po; 1485 1486 sx_assert(&pmc_sx, SX_LOCKED); 1487 1488 /* 1489 * Notify owners of system sampling PMCs about KLD operations. 1490 */ 1491 1492 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1493 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1494 pmclog_process_map_in(po, (pid_t) -1, pkm->pm_address, 1495 (char *) pkm->pm_file); 1496 1497 /* 1498 * TODO: Notify owners of (all) process-sampling PMCs too. 1499 */ 1500 1501 return; 1502 } 1503 1504 static void 1505 pmc_process_kld_unload(struct pmckern_map_out *pkm) 1506 { 1507 struct pmc_owner *po; 1508 1509 sx_assert(&pmc_sx, SX_LOCKED); 1510 1511 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1512 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1513 pmclog_process_map_out(po, (pid_t) -1, 1514 pkm->pm_address, pkm->pm_address + pkm->pm_size); 1515 1516 /* 1517 * TODO: Notify owners of process-sampling PMCs. 1518 */ 1519 } 1520 1521 /* 1522 * A mapping change for a process. 1523 */ 1524 1525 static void 1526 pmc_process_mmap(struct thread *td, struct pmckern_map_in *pkm) 1527 { 1528 int ri; 1529 pid_t pid; 1530 char *fullpath, *freepath; 1531 const struct pmc *pm; 1532 struct pmc_owner *po; 1533 const struct pmc_process *pp; 1534 1535 freepath = fullpath = NULL; 1536 pmc_getfilename((struct vnode *) pkm->pm_file, &fullpath, &freepath); 1537 1538 pid = td->td_proc->p_pid; 1539 1540 /* Inform owners of all system-wide sampling PMCs. */ 1541 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1542 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1543 pmclog_process_map_in(po, pid, pkm->pm_address, fullpath); 1544 1545 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1546 goto done; 1547 1548 /* 1549 * Inform sampling PMC owners tracking this process. 1550 */ 1551 for (ri = 0; ri < md->pmd_npmc; ri++) 1552 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1553 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1554 pmclog_process_map_in(pm->pm_owner, 1555 pid, pkm->pm_address, fullpath); 1556 1557 done: 1558 if (freepath) 1559 free(freepath, M_TEMP); 1560 } 1561 1562 1563 /* 1564 * Log an munmap request. 1565 */ 1566 1567 static void 1568 pmc_process_munmap(struct thread *td, struct pmckern_map_out *pkm) 1569 { 1570 int ri; 1571 pid_t pid; 1572 struct pmc_owner *po; 1573 const struct pmc *pm; 1574 const struct pmc_process *pp; 1575 1576 pid = td->td_proc->p_pid; 1577 1578 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1579 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1580 pmclog_process_map_out(po, pid, pkm->pm_address, 1581 pkm->pm_address + pkm->pm_size); 1582 1583 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1584 return; 1585 1586 for (ri = 0; ri < md->pmd_npmc; ri++) 1587 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1588 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1589 pmclog_process_map_out(pm->pm_owner, pid, 1590 pkm->pm_address, pkm->pm_address + pkm->pm_size); 1591 } 1592 1593 /* 1594 * Log mapping information about the kernel. 1595 */ 1596 1597 static void 1598 pmc_log_kernel_mappings(struct pmc *pm) 1599 { 1600 struct pmc_owner *po; 1601 struct pmckern_map_in *km, *kmbase; 1602 1603 sx_assert(&pmc_sx, SX_LOCKED); 1604 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 1605 ("[pmc,%d] non-sampling PMC (%p) desires mapping information", 1606 __LINE__, (void *) pm)); 1607 1608 po = pm->pm_owner; 1609 1610 if (po->po_flags & PMC_PO_INITIAL_MAPPINGS_DONE) 1611 return; 1612 1613 /* 1614 * Log the current set of kernel modules. 1615 */ 1616 kmbase = linker_hwpmc_list_objects(); 1617 for (km = kmbase; km->pm_file != NULL; km++) { 1618 PMCDBG(LOG,REG,1,"%s %p", (char *) km->pm_file, 1619 (void *) km->pm_address); 1620 pmclog_process_map_in(po, (pid_t) -1, km->pm_address, 1621 km->pm_file); 1622 } 1623 free(kmbase, M_LINKER); 1624 1625 po->po_flags |= PMC_PO_INITIAL_MAPPINGS_DONE; 1626 } 1627 1628 /* 1629 * Log the mappings for a single process. 1630 */ 1631 1632 static void 1633 pmc_log_process_mappings(struct pmc_owner *po, struct proc *p) 1634 { 1635 vm_map_t map; 1636 struct vnode *vp; 1637 struct vmspace *vm; 1638 vm_map_entry_t entry; 1639 vm_offset_t last_end; 1640 u_int last_timestamp; 1641 struct vnode *last_vp; 1642 vm_offset_t start_addr; 1643 vm_object_t obj, lobj, tobj; 1644 char *fullpath, *freepath; 1645 1646 last_vp = NULL; 1647 last_end = (vm_offset_t) 0; 1648 fullpath = freepath = NULL; 1649 1650 if ((vm = vmspace_acquire_ref(p)) == NULL) 1651 return; 1652 1653 map = &vm->vm_map; 1654 vm_map_lock_read(map); 1655 1656 for (entry = map->header.next; entry != &map->header; entry = entry->next) { 1657 1658 if (entry == NULL) { 1659 PMCDBG(LOG,OPS,2, "hwpmc: vm_map entry unexpectedly " 1660 "NULL! pid=%d vm_map=%p\n", p->p_pid, map); 1661 break; 1662 } 1663 1664 /* 1665 * We only care about executable map entries. 1666 */ 1667 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) || 1668 !(entry->protection & VM_PROT_EXECUTE) || 1669 (entry->object.vm_object == NULL)) { 1670 continue; 1671 } 1672 1673 obj = entry->object.vm_object; 1674 VM_OBJECT_LOCK(obj); 1675 1676 /* 1677 * Walk the backing_object list to find the base 1678 * (non-shadowed) vm_object. 1679 */ 1680 for (lobj = tobj = obj; tobj != NULL; tobj = tobj->backing_object) { 1681 if (tobj != obj) 1682 VM_OBJECT_LOCK(tobj); 1683 if (lobj != obj) 1684 VM_OBJECT_UNLOCK(lobj); 1685 lobj = tobj; 1686 } 1687 1688 /* 1689 * At this point lobj is the base vm_object and it is locked. 1690 */ 1691 if (lobj == NULL) { 1692 PMCDBG(LOG,OPS,2, "hwpmc: lobj unexpectedly NULL! pid=%d " 1693 "vm_map=%p vm_obj=%p\n", p->p_pid, map, obj); 1694 VM_OBJECT_UNLOCK(obj); 1695 continue; 1696 } 1697 1698 if (lobj->type != OBJT_VNODE || lobj->handle == NULL) { 1699 if (lobj != obj) 1700 VM_OBJECT_UNLOCK(lobj); 1701 VM_OBJECT_UNLOCK(obj); 1702 continue; 1703 } 1704 1705 /* 1706 * Skip contiguous regions that point to the same 1707 * vnode, so we don't emit redundant MAP-IN 1708 * directives. 1709 */ 1710 if (entry->start == last_end && lobj->handle == last_vp) { 1711 last_end = entry->end; 1712 if (lobj != obj) 1713 VM_OBJECT_UNLOCK(lobj); 1714 VM_OBJECT_UNLOCK(obj); 1715 continue; 1716 } 1717 1718 /* 1719 * We don't want to keep the proc's vm_map or this 1720 * vm_object locked while we walk the pathname, since 1721 * vn_fullpath() can sleep. However, if we drop the 1722 * lock, it's possible for concurrent activity to 1723 * modify the vm_map list. To protect against this, 1724 * we save the vm_map timestamp before we release the 1725 * lock, and check it after we reacquire the lock 1726 * below. 1727 */ 1728 start_addr = entry->start; 1729 last_end = entry->end; 1730 last_timestamp = map->timestamp; 1731 vm_map_unlock_read(map); 1732 1733 vp = lobj->handle; 1734 vref(vp); 1735 if (lobj != obj) 1736 VM_OBJECT_UNLOCK(lobj); 1737 1738 VM_OBJECT_UNLOCK(obj); 1739 1740 freepath = NULL; 1741 pmc_getfilename(vp, &fullpath, &freepath); 1742 last_vp = vp; 1743 1744 vrele(vp); 1745 1746 vp = NULL; 1747 pmclog_process_map_in(po, p->p_pid, start_addr, fullpath); 1748 if (freepath) 1749 free(freepath, M_TEMP); 1750 1751 vm_map_lock_read(map); 1752 1753 /* 1754 * If our saved timestamp doesn't match, this means 1755 * that the vm_map was modified out from under us and 1756 * we can't trust our current "entry" pointer. Do a 1757 * new lookup for this entry. If there is no entry 1758 * for this address range, vm_map_lookup_entry() will 1759 * return the previous one, so we always want to go to 1760 * entry->next on the next loop iteration. 1761 * 1762 * There is an edge condition here that can occur if 1763 * there is no entry at or before this address. In 1764 * this situation, vm_map_lookup_entry returns 1765 * &map->header, which would cause our loop to abort 1766 * without processing the rest of the map. However, 1767 * in practice this will never happen for process 1768 * vm_map. This is because the executable's text 1769 * segment is the first mapping in the proc's address 1770 * space, and this mapping is never removed until the 1771 * process exits, so there will always be a non-header 1772 * entry at or before the requested address for 1773 * vm_map_lookup_entry to return. 1774 */ 1775 if (map->timestamp != last_timestamp) 1776 vm_map_lookup_entry(map, last_end - 1, &entry); 1777 } 1778 1779 vm_map_unlock_read(map); 1780 vmspace_free(vm); 1781 return; 1782 } 1783 1784 /* 1785 * Log mappings for all processes in the system. 1786 */ 1787 1788 static void 1789 pmc_log_all_process_mappings(struct pmc_owner *po) 1790 { 1791 struct proc *p, *top; 1792 1793 sx_assert(&pmc_sx, SX_XLOCKED); 1794 1795 if ((p = pfind(1)) == NULL) 1796 panic("[pmc,%d] Cannot find init", __LINE__); 1797 1798 PROC_UNLOCK(p); 1799 1800 sx_slock(&proctree_lock); 1801 1802 top = p; 1803 1804 for (;;) { 1805 pmc_log_process_mappings(po, p); 1806 if (!LIST_EMPTY(&p->p_children)) 1807 p = LIST_FIRST(&p->p_children); 1808 else for (;;) { 1809 if (p == top) 1810 goto done; 1811 if (LIST_NEXT(p, p_sibling)) { 1812 p = LIST_NEXT(p, p_sibling); 1813 break; 1814 } 1815 p = p->p_pptr; 1816 } 1817 } 1818 done: 1819 sx_sunlock(&proctree_lock); 1820 } 1821 1822 /* 1823 * The 'hook' invoked from the kernel proper 1824 */ 1825 1826 1827 #ifdef DEBUG 1828 const char *pmc_hooknames[] = { 1829 /* these strings correspond to PMC_FN_* in <sys/pmckern.h> */ 1830 "", 1831 "EXEC", 1832 "CSW-IN", 1833 "CSW-OUT", 1834 "SAMPLE", 1835 "KLDLOAD", 1836 "KLDUNLOAD", 1837 "MMAP", 1838 "MUNMAP", 1839 "CALLCHAIN-NMI", 1840 "CALLCHAIN-SOFT", 1841 "SOFTSAMPLING" 1842 }; 1843 #endif 1844 1845 static int 1846 pmc_hook_handler(struct thread *td, int function, void *arg) 1847 { 1848 1849 PMCDBG(MOD,PMH,1, "hook td=%p func=%d \"%s\" arg=%p", td, function, 1850 pmc_hooknames[function], arg); 1851 1852 switch (function) 1853 { 1854 1855 /* 1856 * Process exec() 1857 */ 1858 1859 case PMC_FN_PROCESS_EXEC: 1860 { 1861 char *fullpath, *freepath; 1862 unsigned int ri; 1863 int is_using_hwpmcs; 1864 struct pmc *pm; 1865 struct proc *p; 1866 struct pmc_owner *po; 1867 struct pmc_process *pp; 1868 struct pmckern_procexec *pk; 1869 1870 sx_assert(&pmc_sx, SX_XLOCKED); 1871 1872 p = td->td_proc; 1873 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 1874 1875 pk = (struct pmckern_procexec *) arg; 1876 1877 /* Inform owners of SS mode PMCs of the exec event. */ 1878 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1879 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1880 pmclog_process_procexec(po, PMC_ID_INVALID, 1881 p->p_pid, pk->pm_entryaddr, fullpath); 1882 1883 PROC_LOCK(p); 1884 is_using_hwpmcs = p->p_flag & P_HWPMC; 1885 PROC_UNLOCK(p); 1886 1887 if (!is_using_hwpmcs) { 1888 if (freepath) 1889 free(freepath, M_TEMP); 1890 break; 1891 } 1892 1893 /* 1894 * PMCs are not inherited across an exec(): remove any 1895 * PMCs that this process is the owner of. 1896 */ 1897 1898 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 1899 pmc_remove_owner(po); 1900 pmc_destroy_owner_descriptor(po); 1901 } 1902 1903 /* 1904 * If the process being exec'ed is not the target of any 1905 * PMC, we are done. 1906 */ 1907 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) { 1908 if (freepath) 1909 free(freepath, M_TEMP); 1910 break; 1911 } 1912 1913 /* 1914 * Log the exec event to all monitoring owners. Skip 1915 * owners who have already recieved the event because 1916 * they had system sampling PMCs active. 1917 */ 1918 for (ri = 0; ri < md->pmd_npmc; ri++) 1919 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 1920 po = pm->pm_owner; 1921 if (po->po_sscount == 0 && 1922 po->po_flags & PMC_PO_OWNS_LOGFILE) 1923 pmclog_process_procexec(po, pm->pm_id, 1924 p->p_pid, pk->pm_entryaddr, 1925 fullpath); 1926 } 1927 1928 if (freepath) 1929 free(freepath, M_TEMP); 1930 1931 1932 PMCDBG(PRC,EXC,1, "exec proc=%p (%d, %s) cred-changed=%d", 1933 p, p->p_pid, p->p_comm, pk->pm_credentialschanged); 1934 1935 if (pk->pm_credentialschanged == 0) /* no change */ 1936 break; 1937 1938 /* 1939 * If the newly exec()'ed process has a different credential 1940 * than before, allow it to be the target of a PMC only if 1941 * the PMC's owner has sufficient priviledge. 1942 */ 1943 1944 for (ri = 0; ri < md->pmd_npmc; ri++) 1945 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) 1946 if (pmc_can_attach(pm, td->td_proc) != 0) 1947 pmc_detach_one_process(td->td_proc, 1948 pm, PMC_FLAG_NONE); 1949 1950 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= (int) md->pmd_npmc, 1951 ("[pmc,%d] Illegal ref count %d on pp %p", __LINE__, 1952 pp->pp_refcnt, pp)); 1953 1954 /* 1955 * If this process is no longer the target of any 1956 * PMCs, we can remove the process entry and free 1957 * up space. 1958 */ 1959 1960 if (pp->pp_refcnt == 0) { 1961 pmc_remove_process_descriptor(pp); 1962 free(pp, M_PMC); 1963 break; 1964 } 1965 1966 } 1967 break; 1968 1969 case PMC_FN_CSW_IN: 1970 pmc_process_csw_in(td); 1971 break; 1972 1973 case PMC_FN_CSW_OUT: 1974 pmc_process_csw_out(td); 1975 break; 1976 1977 /* 1978 * Process accumulated PC samples. 1979 * 1980 * This function is expected to be called by hardclock() for 1981 * each CPU that has accumulated PC samples. 1982 * 1983 * This function is to be executed on the CPU whose samples 1984 * are being processed. 1985 */ 1986 case PMC_FN_DO_SAMPLES: 1987 1988 /* 1989 * Clear the cpu specific bit in the CPU mask before 1990 * do the rest of the processing. If the NMI handler 1991 * gets invoked after the "atomic_clear_int()" call 1992 * below but before "pmc_process_samples()" gets 1993 * around to processing the interrupt, then we will 1994 * come back here at the next hardclock() tick (and 1995 * may find nothing to do if "pmc_process_samples()" 1996 * had already processed the interrupt). We don't 1997 * lose the interrupt sample. 1998 */ 1999 CPU_CLR_ATOMIC(PCPU_GET(cpuid), &pmc_cpumask); 2000 pmc_process_samples(PCPU_GET(cpuid), PMC_HR); 2001 pmc_process_samples(PCPU_GET(cpuid), PMC_SR); 2002 break; 2003 2004 2005 case PMC_FN_KLD_LOAD: 2006 sx_assert(&pmc_sx, SX_LOCKED); 2007 pmc_process_kld_load((struct pmckern_map_in *) arg); 2008 break; 2009 2010 case PMC_FN_KLD_UNLOAD: 2011 sx_assert(&pmc_sx, SX_LOCKED); 2012 pmc_process_kld_unload((struct pmckern_map_out *) arg); 2013 break; 2014 2015 case PMC_FN_MMAP: 2016 sx_assert(&pmc_sx, SX_LOCKED); 2017 pmc_process_mmap(td, (struct pmckern_map_in *) arg); 2018 break; 2019 2020 case PMC_FN_MUNMAP: 2021 sx_assert(&pmc_sx, SX_LOCKED); 2022 pmc_process_munmap(td, (struct pmckern_map_out *) arg); 2023 break; 2024 2025 case PMC_FN_USER_CALLCHAIN: 2026 /* 2027 * Record a call chain. 2028 */ 2029 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 2030 __LINE__)); 2031 2032 pmc_capture_user_callchain(PCPU_GET(cpuid), PMC_HR, 2033 (struct trapframe *) arg); 2034 td->td_pflags &= ~TDP_CALLCHAIN; 2035 break; 2036 2037 case PMC_FN_USER_CALLCHAIN_SOFT: 2038 /* 2039 * Record a call chain. 2040 */ 2041 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 2042 __LINE__)); 2043 pmc_capture_user_callchain(PCPU_GET(cpuid), PMC_SR, 2044 (struct trapframe *) arg); 2045 td->td_pflags &= ~TDP_CALLCHAIN; 2046 break; 2047 2048 case PMC_FN_SOFT_SAMPLING: 2049 /* 2050 * Call soft PMC sampling intr. 2051 */ 2052 pmc_soft_intr((struct pmckern_soft *) arg); 2053 break; 2054 2055 default: 2056 #ifdef DEBUG 2057 KASSERT(0, ("[pmc,%d] unknown hook %d\n", __LINE__, function)); 2058 #endif 2059 break; 2060 2061 } 2062 2063 return 0; 2064 } 2065 2066 /* 2067 * allocate a 'struct pmc_owner' descriptor in the owner hash table. 2068 */ 2069 2070 static struct pmc_owner * 2071 pmc_allocate_owner_descriptor(struct proc *p) 2072 { 2073 uint32_t hindex; 2074 struct pmc_owner *po; 2075 struct pmc_ownerhash *poh; 2076 2077 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 2078 poh = &pmc_ownerhash[hindex]; 2079 2080 /* allocate space for N pointers and one descriptor struct */ 2081 po = malloc(sizeof(struct pmc_owner), M_PMC, M_WAITOK|M_ZERO); 2082 po->po_sscount = po->po_error = po->po_flags = po->po_logprocmaps = 0; 2083 po->po_file = NULL; 2084 po->po_owner = p; 2085 po->po_kthread = NULL; 2086 LIST_INIT(&po->po_pmcs); 2087 LIST_INSERT_HEAD(poh, po, po_next); /* insert into hash table */ 2088 2089 TAILQ_INIT(&po->po_logbuffers); 2090 mtx_init(&po->po_mtx, "pmc-owner-mtx", "pmc-per-proc", MTX_SPIN); 2091 2092 PMCDBG(OWN,ALL,1, "allocate-owner proc=%p (%d, %s) pmc-owner=%p", 2093 p, p->p_pid, p->p_comm, po); 2094 2095 return po; 2096 } 2097 2098 static void 2099 pmc_destroy_owner_descriptor(struct pmc_owner *po) 2100 { 2101 2102 PMCDBG(OWN,REL,1, "destroy-owner po=%p proc=%p (%d, %s)", 2103 po, po->po_owner, po->po_owner->p_pid, po->po_owner->p_comm); 2104 2105 mtx_destroy(&po->po_mtx); 2106 free(po, M_PMC); 2107 } 2108 2109 /* 2110 * find the descriptor corresponding to process 'p', adding or removing it 2111 * as specified by 'mode'. 2112 */ 2113 2114 static struct pmc_process * 2115 pmc_find_process_descriptor(struct proc *p, uint32_t mode) 2116 { 2117 uint32_t hindex; 2118 struct pmc_process *pp, *ppnew; 2119 struct pmc_processhash *pph; 2120 2121 hindex = PMC_HASH_PTR(p, pmc_processhashmask); 2122 pph = &pmc_processhash[hindex]; 2123 2124 ppnew = NULL; 2125 2126 /* 2127 * Pre-allocate memory in the FIND_ALLOCATE case since we 2128 * cannot call malloc(9) once we hold a spin lock. 2129 */ 2130 if (mode & PMC_FLAG_ALLOCATE) 2131 ppnew = malloc(sizeof(struct pmc_process) + md->pmd_npmc * 2132 sizeof(struct pmc_targetstate), M_PMC, M_WAITOK|M_ZERO); 2133 2134 mtx_lock_spin(&pmc_processhash_mtx); 2135 LIST_FOREACH(pp, pph, pp_next) 2136 if (pp->pp_proc == p) 2137 break; 2138 2139 if ((mode & PMC_FLAG_REMOVE) && pp != NULL) 2140 LIST_REMOVE(pp, pp_next); 2141 2142 if ((mode & PMC_FLAG_ALLOCATE) && pp == NULL && 2143 ppnew != NULL) { 2144 ppnew->pp_proc = p; 2145 LIST_INSERT_HEAD(pph, ppnew, pp_next); 2146 pp = ppnew; 2147 ppnew = NULL; 2148 } 2149 mtx_unlock_spin(&pmc_processhash_mtx); 2150 2151 if (pp != NULL && ppnew != NULL) 2152 free(ppnew, M_PMC); 2153 2154 return pp; 2155 } 2156 2157 /* 2158 * remove a process descriptor from the process hash table. 2159 */ 2160 2161 static void 2162 pmc_remove_process_descriptor(struct pmc_process *pp) 2163 { 2164 KASSERT(pp->pp_refcnt == 0, 2165 ("[pmc,%d] Removing process descriptor %p with count %d", 2166 __LINE__, pp, pp->pp_refcnt)); 2167 2168 mtx_lock_spin(&pmc_processhash_mtx); 2169 LIST_REMOVE(pp, pp_next); 2170 mtx_unlock_spin(&pmc_processhash_mtx); 2171 } 2172 2173 2174 /* 2175 * find an owner descriptor corresponding to proc 'p' 2176 */ 2177 2178 static struct pmc_owner * 2179 pmc_find_owner_descriptor(struct proc *p) 2180 { 2181 uint32_t hindex; 2182 struct pmc_owner *po; 2183 struct pmc_ownerhash *poh; 2184 2185 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 2186 poh = &pmc_ownerhash[hindex]; 2187 2188 po = NULL; 2189 LIST_FOREACH(po, poh, po_next) 2190 if (po->po_owner == p) 2191 break; 2192 2193 PMCDBG(OWN,FND,1, "find-owner proc=%p (%d, %s) hindex=0x%x -> " 2194 "pmc-owner=%p", p, p->p_pid, p->p_comm, hindex, po); 2195 2196 return po; 2197 } 2198 2199 /* 2200 * pmc_allocate_pmc_descriptor 2201 * 2202 * Allocate a pmc descriptor and initialize its 2203 * fields. 2204 */ 2205 2206 static struct pmc * 2207 pmc_allocate_pmc_descriptor(void) 2208 { 2209 struct pmc *pmc; 2210 2211 pmc = malloc(sizeof(struct pmc), M_PMC, M_WAITOK|M_ZERO); 2212 2213 if (pmc != NULL) { 2214 pmc->pm_owner = NULL; 2215 LIST_INIT(&pmc->pm_targets); 2216 } 2217 2218 PMCDBG(PMC,ALL,1, "allocate-pmc -> pmc=%p", pmc); 2219 2220 return pmc; 2221 } 2222 2223 /* 2224 * Destroy a pmc descriptor. 2225 */ 2226 2227 static void 2228 pmc_destroy_pmc_descriptor(struct pmc *pm) 2229 { 2230 (void) pm; 2231 2232 #ifdef DEBUG 2233 KASSERT(pm->pm_state == PMC_STATE_DELETED || 2234 pm->pm_state == PMC_STATE_FREE, 2235 ("[pmc,%d] destroying non-deleted PMC", __LINE__)); 2236 KASSERT(LIST_EMPTY(&pm->pm_targets), 2237 ("[pmc,%d] destroying pmc with targets", __LINE__)); 2238 KASSERT(pm->pm_owner == NULL, 2239 ("[pmc,%d] destroying pmc attached to an owner", __LINE__)); 2240 KASSERT(pm->pm_runcount == 0, 2241 ("[pmc,%d] pmc has non-zero run count %d", __LINE__, 2242 pm->pm_runcount)); 2243 #endif 2244 } 2245 2246 static void 2247 pmc_wait_for_pmc_idle(struct pmc *pm) 2248 { 2249 #ifdef DEBUG 2250 volatile int maxloop; 2251 2252 maxloop = 100 * pmc_cpu_max(); 2253 #endif 2254 /* 2255 * Loop (with a forced context switch) till the PMC's runcount 2256 * comes down to zero. 2257 */ 2258 while (atomic_load_acq_32(&pm->pm_runcount) > 0) { 2259 #ifdef DEBUG 2260 maxloop--; 2261 KASSERT(maxloop > 0, 2262 ("[pmc,%d] (ri%d, rc%d) waiting too long for " 2263 "pmc to be free", __LINE__, 2264 PMC_TO_ROWINDEX(pm), pm->pm_runcount)); 2265 #endif 2266 pmc_force_context_switch(); 2267 } 2268 } 2269 2270 /* 2271 * This function does the following things: 2272 * 2273 * - detaches the PMC from hardware 2274 * - unlinks all target threads that were attached to it 2275 * - removes the PMC from its owner's list 2276 * - destroy's the PMC private mutex 2277 * 2278 * Once this function completes, the given pmc pointer can be safely 2279 * FREE'd by the caller. 2280 */ 2281 2282 static void 2283 pmc_release_pmc_descriptor(struct pmc *pm) 2284 { 2285 enum pmc_mode mode; 2286 struct pmc_hw *phw; 2287 u_int adjri, ri, cpu; 2288 struct pmc_owner *po; 2289 struct pmc_binding pb; 2290 struct pmc_process *pp; 2291 struct pmc_classdep *pcd; 2292 struct pmc_target *ptgt, *tmp; 2293 2294 sx_assert(&pmc_sx, SX_XLOCKED); 2295 2296 KASSERT(pm, ("[pmc,%d] null pmc", __LINE__)); 2297 2298 ri = PMC_TO_ROWINDEX(pm); 2299 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2300 mode = PMC_TO_MODE(pm); 2301 2302 PMCDBG(PMC,REL,1, "release-pmc pmc=%p ri=%d mode=%d", pm, ri, 2303 mode); 2304 2305 /* 2306 * First, we take the PMC off hardware. 2307 */ 2308 cpu = 0; 2309 if (PMC_IS_SYSTEM_MODE(mode)) { 2310 2311 /* 2312 * A system mode PMC runs on a specific CPU. Switch 2313 * to this CPU and turn hardware off. 2314 */ 2315 pmc_save_cpu_binding(&pb); 2316 2317 cpu = PMC_TO_CPU(pm); 2318 2319 pmc_select_cpu(cpu); 2320 2321 /* switch off non-stalled CPUs */ 2322 if (pm->pm_state == PMC_STATE_RUNNING && 2323 pm->pm_stalled == 0) { 2324 2325 phw = pmc_pcpu[cpu]->pc_hwpmcs[ri]; 2326 2327 KASSERT(phw->phw_pmc == pm, 2328 ("[pmc, %d] pmc ptr ri(%d) hw(%p) pm(%p)", 2329 __LINE__, ri, phw->phw_pmc, pm)); 2330 PMCDBG(PMC,REL,2, "stopping cpu=%d ri=%d", cpu, ri); 2331 2332 critical_enter(); 2333 pcd->pcd_stop_pmc(cpu, adjri); 2334 critical_exit(); 2335 } 2336 2337 PMCDBG(PMC,REL,2, "decfg cpu=%d ri=%d", cpu, ri); 2338 2339 critical_enter(); 2340 pcd->pcd_config_pmc(cpu, adjri, NULL); 2341 critical_exit(); 2342 2343 /* adjust the global and process count of SS mode PMCs */ 2344 if (mode == PMC_MODE_SS && pm->pm_state == PMC_STATE_RUNNING) { 2345 po = pm->pm_owner; 2346 po->po_sscount--; 2347 if (po->po_sscount == 0) { 2348 atomic_subtract_rel_int(&pmc_ss_count, 1); 2349 LIST_REMOVE(po, po_ssnext); 2350 } 2351 } 2352 2353 pm->pm_state = PMC_STATE_DELETED; 2354 2355 pmc_restore_cpu_binding(&pb); 2356 2357 /* 2358 * We could have references to this PMC structure in 2359 * the per-cpu sample queues. Wait for the queue to 2360 * drain. 2361 */ 2362 pmc_wait_for_pmc_idle(pm); 2363 2364 } else if (PMC_IS_VIRTUAL_MODE(mode)) { 2365 2366 /* 2367 * A virtual PMC could be running on multiple CPUs at 2368 * a given instant. 2369 * 2370 * By marking its state as DELETED, we ensure that 2371 * this PMC is never further scheduled on hardware. 2372 * 2373 * Then we wait till all CPUs are done with this PMC. 2374 */ 2375 pm->pm_state = PMC_STATE_DELETED; 2376 2377 2378 /* Wait for the PMCs runcount to come to zero. */ 2379 pmc_wait_for_pmc_idle(pm); 2380 2381 /* 2382 * At this point the PMC is off all CPUs and cannot be 2383 * freshly scheduled onto a CPU. It is now safe to 2384 * unlink all targets from this PMC. If a 2385 * process-record's refcount falls to zero, we remove 2386 * it from the hash table. The module-wide SX lock 2387 * protects us from races. 2388 */ 2389 LIST_FOREACH_SAFE(ptgt, &pm->pm_targets, pt_next, tmp) { 2390 pp = ptgt->pt_process; 2391 pmc_unlink_target_process(pm, pp); /* frees 'ptgt' */ 2392 2393 PMCDBG(PMC,REL,3, "pp->refcnt=%d", pp->pp_refcnt); 2394 2395 /* 2396 * If the target process record shows that no 2397 * PMCs are attached to it, reclaim its space. 2398 */ 2399 2400 if (pp->pp_refcnt == 0) { 2401 pmc_remove_process_descriptor(pp); 2402 free(pp, M_PMC); 2403 } 2404 } 2405 2406 cpu = curthread->td_oncpu; /* setup cpu for pmd_release() */ 2407 2408 } 2409 2410 /* 2411 * Release any MD resources 2412 */ 2413 (void) pcd->pcd_release_pmc(cpu, adjri, pm); 2414 2415 /* 2416 * Update row disposition 2417 */ 2418 2419 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) 2420 PMC_UNMARK_ROW_STANDALONE(ri); 2421 else 2422 PMC_UNMARK_ROW_THREAD(ri); 2423 2424 /* unlink from the owner's list */ 2425 if (pm->pm_owner) { 2426 LIST_REMOVE(pm, pm_next); 2427 pm->pm_owner = NULL; 2428 } 2429 2430 pmc_destroy_pmc_descriptor(pm); 2431 } 2432 2433 /* 2434 * Register an owner and a pmc. 2435 */ 2436 2437 static int 2438 pmc_register_owner(struct proc *p, struct pmc *pmc) 2439 { 2440 struct pmc_owner *po; 2441 2442 sx_assert(&pmc_sx, SX_XLOCKED); 2443 2444 if ((po = pmc_find_owner_descriptor(p)) == NULL) 2445 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) 2446 return ENOMEM; 2447 2448 KASSERT(pmc->pm_owner == NULL, 2449 ("[pmc,%d] attempting to own an initialized PMC", __LINE__)); 2450 pmc->pm_owner = po; 2451 2452 LIST_INSERT_HEAD(&po->po_pmcs, pmc, pm_next); 2453 2454 PROC_LOCK(p); 2455 p->p_flag |= P_HWPMC; 2456 PROC_UNLOCK(p); 2457 2458 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 2459 pmclog_process_pmcallocate(pmc); 2460 2461 PMCDBG(PMC,REG,1, "register-owner pmc-owner=%p pmc=%p", 2462 po, pmc); 2463 2464 return 0; 2465 } 2466 2467 /* 2468 * Return the current row disposition: 2469 * == 0 => FREE 2470 * > 0 => PROCESS MODE 2471 * < 0 => SYSTEM MODE 2472 */ 2473 2474 int 2475 pmc_getrowdisp(int ri) 2476 { 2477 return pmc_pmcdisp[ri]; 2478 } 2479 2480 /* 2481 * Check if a PMC at row index 'ri' can be allocated to the current 2482 * process. 2483 * 2484 * Allocation can fail if: 2485 * - the current process is already being profiled by a PMC at index 'ri', 2486 * attached to it via OP_PMCATTACH. 2487 * - the current process has already allocated a PMC at index 'ri' 2488 * via OP_ALLOCATE. 2489 */ 2490 2491 static int 2492 pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, int cpu) 2493 { 2494 enum pmc_mode mode; 2495 struct pmc *pm; 2496 struct pmc_owner *po; 2497 struct pmc_process *pp; 2498 2499 PMCDBG(PMC,ALR,1, "can-allocate-rowindex proc=%p (%d, %s) ri=%d " 2500 "cpu=%d", p, p->p_pid, p->p_comm, ri, cpu); 2501 2502 /* 2503 * We shouldn't have already allocated a process-mode PMC at 2504 * row index 'ri'. 2505 * 2506 * We shouldn't have allocated a system-wide PMC on the same 2507 * CPU and same RI. 2508 */ 2509 if ((po = pmc_find_owner_descriptor(p)) != NULL) 2510 LIST_FOREACH(pm, &po->po_pmcs, pm_next) { 2511 if (PMC_TO_ROWINDEX(pm) == ri) { 2512 mode = PMC_TO_MODE(pm); 2513 if (PMC_IS_VIRTUAL_MODE(mode)) 2514 return EEXIST; 2515 if (PMC_IS_SYSTEM_MODE(mode) && 2516 (int) PMC_TO_CPU(pm) == cpu) 2517 return EEXIST; 2518 } 2519 } 2520 2521 /* 2522 * We also shouldn't be the target of any PMC at this index 2523 * since otherwise a PMC_ATTACH to ourselves will fail. 2524 */ 2525 if ((pp = pmc_find_process_descriptor(p, 0)) != NULL) 2526 if (pp->pp_pmcs[ri].pp_pmc) 2527 return EEXIST; 2528 2529 PMCDBG(PMC,ALR,2, "can-allocate-rowindex proc=%p (%d, %s) ri=%d ok", 2530 p, p->p_pid, p->p_comm, ri); 2531 2532 return 0; 2533 } 2534 2535 /* 2536 * Check if a given PMC at row index 'ri' can be currently used in 2537 * mode 'mode'. 2538 */ 2539 2540 static int 2541 pmc_can_allocate_row(int ri, enum pmc_mode mode) 2542 { 2543 enum pmc_disp disp; 2544 2545 sx_assert(&pmc_sx, SX_XLOCKED); 2546 2547 PMCDBG(PMC,ALR,1, "can-allocate-row ri=%d mode=%d", ri, mode); 2548 2549 if (PMC_IS_SYSTEM_MODE(mode)) 2550 disp = PMC_DISP_STANDALONE; 2551 else 2552 disp = PMC_DISP_THREAD; 2553 2554 /* 2555 * check disposition for PMC row 'ri': 2556 * 2557 * Expected disposition Row-disposition Result 2558 * 2559 * STANDALONE STANDALONE or FREE proceed 2560 * STANDALONE THREAD fail 2561 * THREAD THREAD or FREE proceed 2562 * THREAD STANDALONE fail 2563 */ 2564 2565 if (!PMC_ROW_DISP_IS_FREE(ri) && 2566 !(disp == PMC_DISP_THREAD && PMC_ROW_DISP_IS_THREAD(ri)) && 2567 !(disp == PMC_DISP_STANDALONE && PMC_ROW_DISP_IS_STANDALONE(ri))) 2568 return EBUSY; 2569 2570 /* 2571 * All OK 2572 */ 2573 2574 PMCDBG(PMC,ALR,2, "can-allocate-row ri=%d mode=%d ok", ri, mode); 2575 2576 return 0; 2577 2578 } 2579 2580 /* 2581 * Find a PMC descriptor with user handle 'pmcid' for thread 'td'. 2582 */ 2583 2584 static struct pmc * 2585 pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, pmc_id_t pmcid) 2586 { 2587 struct pmc *pm; 2588 2589 KASSERT(PMC_ID_TO_ROWINDEX(pmcid) < md->pmd_npmc, 2590 ("[pmc,%d] Illegal pmc index %d (max %d)", __LINE__, 2591 PMC_ID_TO_ROWINDEX(pmcid), md->pmd_npmc)); 2592 2593 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 2594 if (pm->pm_id == pmcid) 2595 return pm; 2596 2597 return NULL; 2598 } 2599 2600 static int 2601 pmc_find_pmc(pmc_id_t pmcid, struct pmc **pmc) 2602 { 2603 2604 struct pmc *pm; 2605 struct pmc_owner *po; 2606 2607 PMCDBG(PMC,FND,1, "find-pmc id=%d", pmcid); 2608 2609 if ((po = pmc_find_owner_descriptor(curthread->td_proc)) == NULL) 2610 return ESRCH; 2611 2612 if ((pm = pmc_find_pmc_descriptor_in_process(po, pmcid)) == NULL) 2613 return EINVAL; 2614 2615 PMCDBG(PMC,FND,2, "find-pmc id=%d -> pmc=%p", pmcid, pm); 2616 2617 *pmc = pm; 2618 return 0; 2619 } 2620 2621 /* 2622 * Start a PMC. 2623 */ 2624 2625 static int 2626 pmc_start(struct pmc *pm) 2627 { 2628 enum pmc_mode mode; 2629 struct pmc_owner *po; 2630 struct pmc_binding pb; 2631 struct pmc_classdep *pcd; 2632 int adjri, error, cpu, ri; 2633 2634 KASSERT(pm != NULL, 2635 ("[pmc,%d] null pm", __LINE__)); 2636 2637 mode = PMC_TO_MODE(pm); 2638 ri = PMC_TO_ROWINDEX(pm); 2639 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2640 2641 error = 0; 2642 2643 PMCDBG(PMC,OPS,1, "start pmc=%p mode=%d ri=%d", pm, mode, ri); 2644 2645 po = pm->pm_owner; 2646 2647 /* 2648 * Disallow PMCSTART if a logfile is required but has not been 2649 * configured yet. 2650 */ 2651 if ((pm->pm_flags & PMC_F_NEEDS_LOGFILE) && 2652 (po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) 2653 return (EDOOFUS); /* programming error */ 2654 2655 /* 2656 * If this is a sampling mode PMC, log mapping information for 2657 * the kernel modules that are currently loaded. 2658 */ 2659 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 2660 pmc_log_kernel_mappings(pm); 2661 2662 if (PMC_IS_VIRTUAL_MODE(mode)) { 2663 2664 /* 2665 * If a PMCATTACH has never been done on this PMC, 2666 * attach it to its owner process. 2667 */ 2668 2669 if (LIST_EMPTY(&pm->pm_targets)) 2670 error = (pm->pm_flags & PMC_F_ATTACH_DONE) ? ESRCH : 2671 pmc_attach_process(po->po_owner, pm); 2672 2673 /* 2674 * If the PMC is attached to its owner, then force a context 2675 * switch to ensure that the MD state gets set correctly. 2676 */ 2677 2678 if (error == 0) { 2679 pm->pm_state = PMC_STATE_RUNNING; 2680 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) 2681 pmc_force_context_switch(); 2682 } 2683 2684 return (error); 2685 } 2686 2687 2688 /* 2689 * A system-wide PMC. 2690 * 2691 * Add the owner to the global list if this is a system-wide 2692 * sampling PMC. 2693 */ 2694 2695 if (mode == PMC_MODE_SS) { 2696 if (po->po_sscount == 0) { 2697 LIST_INSERT_HEAD(&pmc_ss_owners, po, po_ssnext); 2698 atomic_add_rel_int(&pmc_ss_count, 1); 2699 PMCDBG(PMC,OPS,1, "po=%p in global list", po); 2700 } 2701 po->po_sscount++; 2702 2703 /* 2704 * Log mapping information for all existing processes in the 2705 * system. Subsequent mappings are logged as they happen; 2706 * see pmc_process_mmap(). 2707 */ 2708 if (po->po_logprocmaps == 0) { 2709 pmc_log_all_process_mappings(po); 2710 po->po_logprocmaps = 1; 2711 } 2712 } 2713 2714 /* 2715 * Move to the CPU associated with this 2716 * PMC, and start the hardware. 2717 */ 2718 2719 pmc_save_cpu_binding(&pb); 2720 2721 cpu = PMC_TO_CPU(pm); 2722 2723 if (!pmc_cpu_is_active(cpu)) 2724 return (ENXIO); 2725 2726 pmc_select_cpu(cpu); 2727 2728 /* 2729 * global PMCs are configured at allocation time 2730 * so write out the initial value and start the PMC. 2731 */ 2732 2733 pm->pm_state = PMC_STATE_RUNNING; 2734 2735 critical_enter(); 2736 if ((error = pcd->pcd_write_pmc(cpu, adjri, 2737 PMC_IS_SAMPLING_MODE(mode) ? 2738 pm->pm_sc.pm_reloadcount : 2739 pm->pm_sc.pm_initial)) == 0) 2740 error = pcd->pcd_start_pmc(cpu, adjri); 2741 critical_exit(); 2742 2743 pmc_restore_cpu_binding(&pb); 2744 2745 return (error); 2746 } 2747 2748 /* 2749 * Stop a PMC. 2750 */ 2751 2752 static int 2753 pmc_stop(struct pmc *pm) 2754 { 2755 struct pmc_owner *po; 2756 struct pmc_binding pb; 2757 struct pmc_classdep *pcd; 2758 int adjri, cpu, error, ri; 2759 2760 KASSERT(pm != NULL, ("[pmc,%d] null pmc", __LINE__)); 2761 2762 PMCDBG(PMC,OPS,1, "stop pmc=%p mode=%d ri=%d", pm, 2763 PMC_TO_MODE(pm), PMC_TO_ROWINDEX(pm)); 2764 2765 pm->pm_state = PMC_STATE_STOPPED; 2766 2767 /* 2768 * If the PMC is a virtual mode one, changing the state to 2769 * non-RUNNING is enough to ensure that the PMC never gets 2770 * scheduled. 2771 * 2772 * If this PMC is current running on a CPU, then it will 2773 * handled correctly at the time its target process is context 2774 * switched out. 2775 */ 2776 2777 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 2778 return 0; 2779 2780 /* 2781 * A system-mode PMC. Move to the CPU associated with 2782 * this PMC, and stop the hardware. We update the 2783 * 'initial count' so that a subsequent PMCSTART will 2784 * resume counting from the current hardware count. 2785 */ 2786 2787 pmc_save_cpu_binding(&pb); 2788 2789 cpu = PMC_TO_CPU(pm); 2790 2791 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 2792 ("[pmc,%d] illegal cpu=%d", __LINE__, cpu)); 2793 2794 if (!pmc_cpu_is_active(cpu)) 2795 return ENXIO; 2796 2797 pmc_select_cpu(cpu); 2798 2799 ri = PMC_TO_ROWINDEX(pm); 2800 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2801 2802 critical_enter(); 2803 if ((error = pcd->pcd_stop_pmc(cpu, adjri)) == 0) 2804 error = pcd->pcd_read_pmc(cpu, adjri, &pm->pm_sc.pm_initial); 2805 critical_exit(); 2806 2807 pmc_restore_cpu_binding(&pb); 2808 2809 po = pm->pm_owner; 2810 2811 /* remove this owner from the global list of SS PMC owners */ 2812 if (PMC_TO_MODE(pm) == PMC_MODE_SS) { 2813 po->po_sscount--; 2814 if (po->po_sscount == 0) { 2815 atomic_subtract_rel_int(&pmc_ss_count, 1); 2816 LIST_REMOVE(po, po_ssnext); 2817 PMCDBG(PMC,OPS,2,"po=%p removed from global list", po); 2818 } 2819 } 2820 2821 return (error); 2822 } 2823 2824 2825 #ifdef DEBUG 2826 static const char *pmc_op_to_name[] = { 2827 #undef __PMC_OP 2828 #define __PMC_OP(N, D) #N , 2829 __PMC_OPS() 2830 NULL 2831 }; 2832 #endif 2833 2834 /* 2835 * The syscall interface 2836 */ 2837 2838 #define PMC_GET_SX_XLOCK(...) do { \ 2839 sx_xlock(&pmc_sx); \ 2840 if (pmc_hook == NULL) { \ 2841 sx_xunlock(&pmc_sx); \ 2842 return __VA_ARGS__; \ 2843 } \ 2844 } while (0) 2845 2846 #define PMC_DOWNGRADE_SX() do { \ 2847 sx_downgrade(&pmc_sx); \ 2848 is_sx_downgraded = 1; \ 2849 } while (0) 2850 2851 static int 2852 pmc_syscall_handler(struct thread *td, void *syscall_args) 2853 { 2854 int error, is_sx_downgraded, is_sx_locked, op; 2855 struct pmc_syscall_args *c; 2856 void *arg; 2857 2858 PMC_GET_SX_XLOCK(ENOSYS); 2859 2860 DROP_GIANT(); 2861 2862 is_sx_downgraded = 0; 2863 is_sx_locked = 1; 2864 2865 c = (struct pmc_syscall_args *) syscall_args; 2866 2867 op = c->pmop_code; 2868 arg = c->pmop_data; 2869 2870 PMCDBG(MOD,PMS,1, "syscall op=%d \"%s\" arg=%p", op, 2871 pmc_op_to_name[op], arg); 2872 2873 error = 0; 2874 atomic_add_int(&pmc_stats.pm_syscalls, 1); 2875 2876 switch(op) 2877 { 2878 2879 2880 /* 2881 * Configure a log file. 2882 * 2883 * XXX This OP will be reworked. 2884 */ 2885 2886 case PMC_OP_CONFIGURELOG: 2887 { 2888 struct proc *p; 2889 struct pmc *pm; 2890 struct pmc_owner *po; 2891 struct pmc_op_configurelog cl; 2892 2893 sx_assert(&pmc_sx, SX_XLOCKED); 2894 2895 if ((error = copyin(arg, &cl, sizeof(cl))) != 0) 2896 break; 2897 2898 /* mark this process as owning a log file */ 2899 p = td->td_proc; 2900 if ((po = pmc_find_owner_descriptor(p)) == NULL) 2901 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) { 2902 error = ENOMEM; 2903 break; 2904 } 2905 2906 /* 2907 * If a valid fd was passed in, try to configure that, 2908 * otherwise if 'fd' was less than zero and there was 2909 * a log file configured, flush its buffers and 2910 * de-configure it. 2911 */ 2912 if (cl.pm_logfd >= 0) { 2913 sx_xunlock(&pmc_sx); 2914 is_sx_locked = 0; 2915 error = pmclog_configure_log(md, po, cl.pm_logfd); 2916 } else if (po->po_flags & PMC_PO_OWNS_LOGFILE) { 2917 pmclog_process_closelog(po); 2918 error = pmclog_close(po); 2919 if (error == 0) { 2920 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 2921 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 2922 pm->pm_state == PMC_STATE_RUNNING) 2923 pmc_stop(pm); 2924 error = pmclog_deconfigure_log(po); 2925 } 2926 } else 2927 error = EINVAL; 2928 2929 if (error) 2930 break; 2931 } 2932 break; 2933 2934 /* 2935 * Flush a log file. 2936 */ 2937 2938 case PMC_OP_FLUSHLOG: 2939 { 2940 struct pmc_owner *po; 2941 2942 sx_assert(&pmc_sx, SX_XLOCKED); 2943 2944 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 2945 error = EINVAL; 2946 break; 2947 } 2948 2949 error = pmclog_flush(po); 2950 } 2951 break; 2952 2953 /* 2954 * Close a log file. 2955 */ 2956 2957 case PMC_OP_CLOSELOG: 2958 { 2959 struct pmc_owner *po; 2960 2961 sx_assert(&pmc_sx, SX_XLOCKED); 2962 2963 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 2964 error = EINVAL; 2965 break; 2966 } 2967 2968 error = pmclog_close(po); 2969 } 2970 break; 2971 2972 /* 2973 * Retrieve hardware configuration. 2974 */ 2975 2976 case PMC_OP_GETCPUINFO: /* CPU information */ 2977 { 2978 struct pmc_op_getcpuinfo gci; 2979 struct pmc_classinfo *pci; 2980 struct pmc_classdep *pcd; 2981 int cl; 2982 2983 gci.pm_cputype = md->pmd_cputype; 2984 gci.pm_ncpu = pmc_cpu_max(); 2985 gci.pm_npmc = md->pmd_npmc; 2986 gci.pm_nclass = md->pmd_nclass; 2987 pci = gci.pm_classes; 2988 pcd = md->pmd_classdep; 2989 for (cl = 0; cl < md->pmd_nclass; cl++, pci++, pcd++) { 2990 pci->pm_caps = pcd->pcd_caps; 2991 pci->pm_class = pcd->pcd_class; 2992 pci->pm_width = pcd->pcd_width; 2993 pci->pm_num = pcd->pcd_num; 2994 } 2995 error = copyout(&gci, arg, sizeof(gci)); 2996 } 2997 break; 2998 2999 /* 3000 * Retrieve soft events list. 3001 */ 3002 case PMC_OP_GETDYNEVENTINFO: 3003 { 3004 enum pmc_class cl; 3005 enum pmc_event ev; 3006 struct pmc_op_getdyneventinfo *gei; 3007 struct pmc_dyn_event_descr dev; 3008 struct pmc_soft *ps; 3009 uint32_t nevent; 3010 3011 sx_assert(&pmc_sx, SX_LOCKED); 3012 3013 gei = (struct pmc_op_getdyneventinfo *) arg; 3014 3015 if ((error = copyin(&gei->pm_class, &cl, sizeof(cl))) != 0) 3016 break; 3017 3018 /* Only SOFT class is dynamic. */ 3019 if (cl != PMC_CLASS_SOFT) { 3020 error = EINVAL; 3021 break; 3022 } 3023 3024 nevent = 0; 3025 for (ev = PMC_EV_SOFT_FIRST; ev <= PMC_EV_SOFT_LAST; ev++) { 3026 ps = pmc_soft_ev_acquire(ev); 3027 if (ps == NULL) 3028 continue; 3029 bcopy(&ps->ps_ev, &dev, sizeof(dev)); 3030 pmc_soft_ev_release(ps); 3031 3032 error = copyout(&dev, 3033 &gei->pm_events[nevent], 3034 sizeof(struct pmc_dyn_event_descr)); 3035 if (error != 0) 3036 break; 3037 nevent++; 3038 } 3039 if (error != 0) 3040 break; 3041 3042 error = copyout(&nevent, &gei->pm_nevent, 3043 sizeof(nevent)); 3044 } 3045 break; 3046 3047 /* 3048 * Get module statistics 3049 */ 3050 3051 case PMC_OP_GETDRIVERSTATS: 3052 { 3053 struct pmc_op_getdriverstats gms; 3054 3055 bcopy(&pmc_stats, &gms, sizeof(gms)); 3056 error = copyout(&gms, arg, sizeof(gms)); 3057 } 3058 break; 3059 3060 3061 /* 3062 * Retrieve module version number 3063 */ 3064 3065 case PMC_OP_GETMODULEVERSION: 3066 { 3067 uint32_t cv, modv; 3068 3069 /* retrieve the client's idea of the ABI version */ 3070 if ((error = copyin(arg, &cv, sizeof(uint32_t))) != 0) 3071 break; 3072 /* don't service clients newer than our driver */ 3073 modv = PMC_VERSION; 3074 if ((cv & 0xFFFF0000) > (modv & 0xFFFF0000)) { 3075 error = EPROGMISMATCH; 3076 break; 3077 } 3078 error = copyout(&modv, arg, sizeof(int)); 3079 } 3080 break; 3081 3082 3083 /* 3084 * Retrieve the state of all the PMCs on a given 3085 * CPU. 3086 */ 3087 3088 case PMC_OP_GETPMCINFO: 3089 { 3090 int ari; 3091 struct pmc *pm; 3092 size_t pmcinfo_size; 3093 uint32_t cpu, n, npmc; 3094 struct pmc_owner *po; 3095 struct pmc_binding pb; 3096 struct pmc_classdep *pcd; 3097 struct pmc_info *p, *pmcinfo; 3098 struct pmc_op_getpmcinfo *gpi; 3099 3100 PMC_DOWNGRADE_SX(); 3101 3102 gpi = (struct pmc_op_getpmcinfo *) arg; 3103 3104 if ((error = copyin(&gpi->pm_cpu, &cpu, sizeof(cpu))) != 0) 3105 break; 3106 3107 if (cpu >= pmc_cpu_max()) { 3108 error = EINVAL; 3109 break; 3110 } 3111 3112 if (!pmc_cpu_is_active(cpu)) { 3113 error = ENXIO; 3114 break; 3115 } 3116 3117 /* switch to CPU 'cpu' */ 3118 pmc_save_cpu_binding(&pb); 3119 pmc_select_cpu(cpu); 3120 3121 npmc = md->pmd_npmc; 3122 3123 pmcinfo_size = npmc * sizeof(struct pmc_info); 3124 pmcinfo = malloc(pmcinfo_size, M_PMC, M_WAITOK); 3125 3126 p = pmcinfo; 3127 3128 for (n = 0; n < md->pmd_npmc; n++, p++) { 3129 3130 pcd = pmc_ri_to_classdep(md, n, &ari); 3131 3132 KASSERT(pcd != NULL, 3133 ("[pmc,%d] null pcd ri=%d", __LINE__, n)); 3134 3135 if ((error = pcd->pcd_describe(cpu, ari, p, &pm)) != 0) 3136 break; 3137 3138 if (PMC_ROW_DISP_IS_STANDALONE(n)) 3139 p->pm_rowdisp = PMC_DISP_STANDALONE; 3140 else if (PMC_ROW_DISP_IS_THREAD(n)) 3141 p->pm_rowdisp = PMC_DISP_THREAD; 3142 else 3143 p->pm_rowdisp = PMC_DISP_FREE; 3144 3145 p->pm_ownerpid = -1; 3146 3147 if (pm == NULL) /* no PMC associated */ 3148 continue; 3149 3150 po = pm->pm_owner; 3151 3152 KASSERT(po->po_owner != NULL, 3153 ("[pmc,%d] pmc_owner had a null proc pointer", 3154 __LINE__)); 3155 3156 p->pm_ownerpid = po->po_owner->p_pid; 3157 p->pm_mode = PMC_TO_MODE(pm); 3158 p->pm_event = pm->pm_event; 3159 p->pm_flags = pm->pm_flags; 3160 3161 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 3162 p->pm_reloadcount = 3163 pm->pm_sc.pm_reloadcount; 3164 } 3165 3166 pmc_restore_cpu_binding(&pb); 3167 3168 /* now copy out the PMC info collected */ 3169 if (error == 0) 3170 error = copyout(pmcinfo, &gpi->pm_pmcs, pmcinfo_size); 3171 3172 free(pmcinfo, M_PMC); 3173 } 3174 break; 3175 3176 3177 /* 3178 * Set the administrative state of a PMC. I.e. whether 3179 * the PMC is to be used or not. 3180 */ 3181 3182 case PMC_OP_PMCADMIN: 3183 { 3184 int cpu, ri; 3185 enum pmc_state request; 3186 struct pmc_cpu *pc; 3187 struct pmc_hw *phw; 3188 struct pmc_op_pmcadmin pma; 3189 struct pmc_binding pb; 3190 3191 sx_assert(&pmc_sx, SX_XLOCKED); 3192 3193 KASSERT(td == curthread, 3194 ("[pmc,%d] td != curthread", __LINE__)); 3195 3196 error = priv_check(td, PRIV_PMC_MANAGE); 3197 if (error) 3198 break; 3199 3200 if ((error = copyin(arg, &pma, sizeof(pma))) != 0) 3201 break; 3202 3203 cpu = pma.pm_cpu; 3204 3205 if (cpu < 0 || cpu >= (int) pmc_cpu_max()) { 3206 error = EINVAL; 3207 break; 3208 } 3209 3210 if (!pmc_cpu_is_active(cpu)) { 3211 error = ENXIO; 3212 break; 3213 } 3214 3215 request = pma.pm_state; 3216 3217 if (request != PMC_STATE_DISABLED && 3218 request != PMC_STATE_FREE) { 3219 error = EINVAL; 3220 break; 3221 } 3222 3223 ri = pma.pm_pmc; /* pmc id == row index */ 3224 if (ri < 0 || ri >= (int) md->pmd_npmc) { 3225 error = EINVAL; 3226 break; 3227 } 3228 3229 /* 3230 * We can't disable a PMC with a row-index allocated 3231 * for process virtual PMCs. 3232 */ 3233 3234 if (PMC_ROW_DISP_IS_THREAD(ri) && 3235 request == PMC_STATE_DISABLED) { 3236 error = EBUSY; 3237 break; 3238 } 3239 3240 /* 3241 * otherwise, this PMC on this CPU is either free or 3242 * in system-wide mode. 3243 */ 3244 3245 pmc_save_cpu_binding(&pb); 3246 pmc_select_cpu(cpu); 3247 3248 pc = pmc_pcpu[cpu]; 3249 phw = pc->pc_hwpmcs[ri]; 3250 3251 /* 3252 * XXX do we need some kind of 'forced' disable? 3253 */ 3254 3255 if (phw->phw_pmc == NULL) { 3256 if (request == PMC_STATE_DISABLED && 3257 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED)) { 3258 phw->phw_state &= ~PMC_PHW_FLAG_IS_ENABLED; 3259 PMC_MARK_ROW_STANDALONE(ri); 3260 } else if (request == PMC_STATE_FREE && 3261 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0) { 3262 phw->phw_state |= PMC_PHW_FLAG_IS_ENABLED; 3263 PMC_UNMARK_ROW_STANDALONE(ri); 3264 } 3265 /* other cases are a no-op */ 3266 } else 3267 error = EBUSY; 3268 3269 pmc_restore_cpu_binding(&pb); 3270 } 3271 break; 3272 3273 3274 /* 3275 * Allocate a PMC. 3276 */ 3277 3278 case PMC_OP_PMCALLOCATE: 3279 { 3280 int adjri, n; 3281 u_int cpu; 3282 uint32_t caps; 3283 struct pmc *pmc; 3284 enum pmc_mode mode; 3285 struct pmc_hw *phw; 3286 struct pmc_binding pb; 3287 struct pmc_classdep *pcd; 3288 struct pmc_op_pmcallocate pa; 3289 3290 if ((error = copyin(arg, &pa, sizeof(pa))) != 0) 3291 break; 3292 3293 caps = pa.pm_caps; 3294 mode = pa.pm_mode; 3295 cpu = pa.pm_cpu; 3296 3297 if ((mode != PMC_MODE_SS && mode != PMC_MODE_SC && 3298 mode != PMC_MODE_TS && mode != PMC_MODE_TC) || 3299 (cpu != (u_int) PMC_CPU_ANY && cpu >= pmc_cpu_max())) { 3300 error = EINVAL; 3301 break; 3302 } 3303 3304 /* 3305 * Virtual PMCs should only ask for a default CPU. 3306 * System mode PMCs need to specify a non-default CPU. 3307 */ 3308 3309 if ((PMC_IS_VIRTUAL_MODE(mode) && cpu != (u_int) PMC_CPU_ANY) || 3310 (PMC_IS_SYSTEM_MODE(mode) && cpu == (u_int) PMC_CPU_ANY)) { 3311 error = EINVAL; 3312 break; 3313 } 3314 3315 /* 3316 * Check that an inactive CPU is not being asked for. 3317 */ 3318 3319 if (PMC_IS_SYSTEM_MODE(mode) && !pmc_cpu_is_active(cpu)) { 3320 error = ENXIO; 3321 break; 3322 } 3323 3324 /* 3325 * Refuse an allocation for a system-wide PMC if this 3326 * process has been jailed, or if this process lacks 3327 * super-user credentials and the sysctl tunable 3328 * 'security.bsd.unprivileged_syspmcs' is zero. 3329 */ 3330 3331 if (PMC_IS_SYSTEM_MODE(mode)) { 3332 if (jailed(curthread->td_ucred)) { 3333 error = EPERM; 3334 break; 3335 } 3336 if (!pmc_unprivileged_syspmcs) { 3337 error = priv_check(curthread, 3338 PRIV_PMC_SYSTEM); 3339 if (error) 3340 break; 3341 } 3342 } 3343 3344 /* 3345 * Look for valid values for 'pm_flags' 3346 */ 3347 3348 if ((pa.pm_flags & ~(PMC_F_DESCENDANTS | PMC_F_LOG_PROCCSW | 3349 PMC_F_LOG_PROCEXIT | PMC_F_CALLCHAIN)) != 0) { 3350 error = EINVAL; 3351 break; 3352 } 3353 3354 /* process logging options are not allowed for system PMCs */ 3355 if (PMC_IS_SYSTEM_MODE(mode) && (pa.pm_flags & 3356 (PMC_F_LOG_PROCCSW | PMC_F_LOG_PROCEXIT))) { 3357 error = EINVAL; 3358 break; 3359 } 3360 3361 /* 3362 * All sampling mode PMCs need to be able to interrupt the 3363 * CPU. 3364 */ 3365 if (PMC_IS_SAMPLING_MODE(mode)) 3366 caps |= PMC_CAP_INTERRUPT; 3367 3368 /* A valid class specifier should have been passed in. */ 3369 for (n = 0; n < md->pmd_nclass; n++) 3370 if (md->pmd_classdep[n].pcd_class == pa.pm_class) 3371 break; 3372 if (n == md->pmd_nclass) { 3373 error = EINVAL; 3374 break; 3375 } 3376 3377 /* The requested PMC capabilities should be feasible. */ 3378 if ((md->pmd_classdep[n].pcd_caps & caps) != caps) { 3379 error = EOPNOTSUPP; 3380 break; 3381 } 3382 3383 PMCDBG(PMC,ALL,2, "event=%d caps=0x%x mode=%d cpu=%d", 3384 pa.pm_ev, caps, mode, cpu); 3385 3386 pmc = pmc_allocate_pmc_descriptor(); 3387 pmc->pm_id = PMC_ID_MAKE_ID(cpu,pa.pm_mode,pa.pm_class, 3388 PMC_ID_INVALID); 3389 pmc->pm_event = pa.pm_ev; 3390 pmc->pm_state = PMC_STATE_FREE; 3391 pmc->pm_caps = caps; 3392 pmc->pm_flags = pa.pm_flags; 3393 3394 /* switch thread to CPU 'cpu' */ 3395 pmc_save_cpu_binding(&pb); 3396 3397 #define PMC_IS_SHAREABLE_PMC(cpu, n) \ 3398 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_state & \ 3399 PMC_PHW_FLAG_IS_SHAREABLE) 3400 #define PMC_IS_UNALLOCATED(cpu, n) \ 3401 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_pmc == NULL) 3402 3403 if (PMC_IS_SYSTEM_MODE(mode)) { 3404 pmc_select_cpu(cpu); 3405 for (n = 0; n < (int) md->pmd_npmc; n++) { 3406 pcd = pmc_ri_to_classdep(md, n, &adjri); 3407 if (pmc_can_allocate_row(n, mode) == 0 && 3408 pmc_can_allocate_rowindex( 3409 curthread->td_proc, n, cpu) == 0 && 3410 (PMC_IS_UNALLOCATED(cpu, n) || 3411 PMC_IS_SHAREABLE_PMC(cpu, n)) && 3412 pcd->pcd_allocate_pmc(cpu, adjri, pmc, 3413 &pa) == 0) 3414 break; 3415 } 3416 } else { 3417 /* Process virtual mode */ 3418 for (n = 0; n < (int) md->pmd_npmc; n++) { 3419 pcd = pmc_ri_to_classdep(md, n, &adjri); 3420 if (pmc_can_allocate_row(n, mode) == 0 && 3421 pmc_can_allocate_rowindex( 3422 curthread->td_proc, n, 3423 PMC_CPU_ANY) == 0 && 3424 pcd->pcd_allocate_pmc(curthread->td_oncpu, 3425 adjri, pmc, &pa) == 0) 3426 break; 3427 } 3428 } 3429 3430 #undef PMC_IS_UNALLOCATED 3431 #undef PMC_IS_SHAREABLE_PMC 3432 3433 pmc_restore_cpu_binding(&pb); 3434 3435 if (n == (int) md->pmd_npmc) { 3436 pmc_destroy_pmc_descriptor(pmc); 3437 free(pmc, M_PMC); 3438 pmc = NULL; 3439 error = EINVAL; 3440 break; 3441 } 3442 3443 /* Fill in the correct value in the ID field */ 3444 pmc->pm_id = PMC_ID_MAKE_ID(cpu,mode,pa.pm_class,n); 3445 3446 PMCDBG(PMC,ALL,2, "ev=%d class=%d mode=%d n=%d -> pmcid=%x", 3447 pmc->pm_event, pa.pm_class, mode, n, pmc->pm_id); 3448 3449 /* Process mode PMCs with logging enabled need log files */ 3450 if (pmc->pm_flags & (PMC_F_LOG_PROCEXIT | PMC_F_LOG_PROCCSW)) 3451 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3452 3453 /* All system mode sampling PMCs require a log file */ 3454 if (PMC_IS_SAMPLING_MODE(mode) && PMC_IS_SYSTEM_MODE(mode)) 3455 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3456 3457 /* 3458 * Configure global pmc's immediately 3459 */ 3460 3461 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pmc))) { 3462 3463 pmc_save_cpu_binding(&pb); 3464 pmc_select_cpu(cpu); 3465 3466 phw = pmc_pcpu[cpu]->pc_hwpmcs[n]; 3467 pcd = pmc_ri_to_classdep(md, n, &adjri); 3468 3469 if ((phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0 || 3470 (error = pcd->pcd_config_pmc(cpu, adjri, pmc)) != 0) { 3471 (void) pcd->pcd_release_pmc(cpu, adjri, pmc); 3472 pmc_destroy_pmc_descriptor(pmc); 3473 free(pmc, M_PMC); 3474 pmc = NULL; 3475 pmc_restore_cpu_binding(&pb); 3476 error = EPERM; 3477 break; 3478 } 3479 3480 pmc_restore_cpu_binding(&pb); 3481 } 3482 3483 pmc->pm_state = PMC_STATE_ALLOCATED; 3484 3485 /* 3486 * mark row disposition 3487 */ 3488 3489 if (PMC_IS_SYSTEM_MODE(mode)) 3490 PMC_MARK_ROW_STANDALONE(n); 3491 else 3492 PMC_MARK_ROW_THREAD(n); 3493 3494 /* 3495 * Register this PMC with the current thread as its owner. 3496 */ 3497 3498 if ((error = 3499 pmc_register_owner(curthread->td_proc, pmc)) != 0) { 3500 pmc_release_pmc_descriptor(pmc); 3501 free(pmc, M_PMC); 3502 pmc = NULL; 3503 break; 3504 } 3505 3506 /* 3507 * Return the allocated index. 3508 */ 3509 3510 pa.pm_pmcid = pmc->pm_id; 3511 3512 error = copyout(&pa, arg, sizeof(pa)); 3513 } 3514 break; 3515 3516 3517 /* 3518 * Attach a PMC to a process. 3519 */ 3520 3521 case PMC_OP_PMCATTACH: 3522 { 3523 struct pmc *pm; 3524 struct proc *p; 3525 struct pmc_op_pmcattach a; 3526 3527 sx_assert(&pmc_sx, SX_XLOCKED); 3528 3529 if ((error = copyin(arg, &a, sizeof(a))) != 0) 3530 break; 3531 3532 if (a.pm_pid < 0) { 3533 error = EINVAL; 3534 break; 3535 } else if (a.pm_pid == 0) 3536 a.pm_pid = td->td_proc->p_pid; 3537 3538 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 3539 break; 3540 3541 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) { 3542 error = EINVAL; 3543 break; 3544 } 3545 3546 /* PMCs may be (re)attached only when allocated or stopped */ 3547 if (pm->pm_state == PMC_STATE_RUNNING) { 3548 error = EBUSY; 3549 break; 3550 } else if (pm->pm_state != PMC_STATE_ALLOCATED && 3551 pm->pm_state != PMC_STATE_STOPPED) { 3552 error = EINVAL; 3553 break; 3554 } 3555 3556 /* lookup pid */ 3557 if ((p = pfind(a.pm_pid)) == NULL) { 3558 error = ESRCH; 3559 break; 3560 } 3561 3562 /* 3563 * Ignore processes that are working on exiting. 3564 */ 3565 if (p->p_flag & P_WEXIT) { 3566 error = ESRCH; 3567 PROC_UNLOCK(p); /* pfind() returns a locked process */ 3568 break; 3569 } 3570 3571 /* 3572 * we are allowed to attach a PMC to a process if 3573 * we can debug it. 3574 */ 3575 error = p_candebug(curthread, p); 3576 3577 PROC_UNLOCK(p); 3578 3579 if (error == 0) 3580 error = pmc_attach_process(p, pm); 3581 } 3582 break; 3583 3584 3585 /* 3586 * Detach an attached PMC from a process. 3587 */ 3588 3589 case PMC_OP_PMCDETACH: 3590 { 3591 struct pmc *pm; 3592 struct proc *p; 3593 struct pmc_op_pmcattach a; 3594 3595 if ((error = copyin(arg, &a, sizeof(a))) != 0) 3596 break; 3597 3598 if (a.pm_pid < 0) { 3599 error = EINVAL; 3600 break; 3601 } else if (a.pm_pid == 0) 3602 a.pm_pid = td->td_proc->p_pid; 3603 3604 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 3605 break; 3606 3607 if ((p = pfind(a.pm_pid)) == NULL) { 3608 error = ESRCH; 3609 break; 3610 } 3611 3612 /* 3613 * Treat processes that are in the process of exiting 3614 * as if they were not present. 3615 */ 3616 3617 if (p->p_flag & P_WEXIT) 3618 error = ESRCH; 3619 3620 PROC_UNLOCK(p); /* pfind() returns a locked process */ 3621 3622 if (error == 0) 3623 error = pmc_detach_process(p, pm); 3624 } 3625 break; 3626 3627 3628 /* 3629 * Retrieve the MSR number associated with the counter 3630 * 'pmc_id'. This allows processes to directly use RDPMC 3631 * instructions to read their PMCs, without the overhead of a 3632 * system call. 3633 */ 3634 3635 case PMC_OP_PMCGETMSR: 3636 { 3637 int adjri, ri; 3638 struct pmc *pm; 3639 struct pmc_target *pt; 3640 struct pmc_op_getmsr gm; 3641 struct pmc_classdep *pcd; 3642 3643 PMC_DOWNGRADE_SX(); 3644 3645 if ((error = copyin(arg, &gm, sizeof(gm))) != 0) 3646 break; 3647 3648 if ((error = pmc_find_pmc(gm.pm_pmcid, &pm)) != 0) 3649 break; 3650 3651 /* 3652 * The allocated PMC has to be a process virtual PMC, 3653 * i.e., of type MODE_T[CS]. Global PMCs can only be 3654 * read using the PMCREAD operation since they may be 3655 * allocated on a different CPU than the one we could 3656 * be running on at the time of the RDPMC instruction. 3657 * 3658 * The GETMSR operation is not allowed for PMCs that 3659 * are inherited across processes. 3660 */ 3661 3662 if (!PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)) || 3663 (pm->pm_flags & PMC_F_DESCENDANTS)) { 3664 error = EINVAL; 3665 break; 3666 } 3667 3668 /* 3669 * It only makes sense to use a RDPMC (or its 3670 * equivalent instruction on non-x86 architectures) on 3671 * a process that has allocated and attached a PMC to 3672 * itself. Conversely the PMC is only allowed to have 3673 * one process attached to it -- its owner. 3674 */ 3675 3676 if ((pt = LIST_FIRST(&pm->pm_targets)) == NULL || 3677 LIST_NEXT(pt, pt_next) != NULL || 3678 pt->pt_process->pp_proc != pm->pm_owner->po_owner) { 3679 error = EINVAL; 3680 break; 3681 } 3682 3683 ri = PMC_TO_ROWINDEX(pm); 3684 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3685 3686 /* PMC class has no 'GETMSR' support */ 3687 if (pcd->pcd_get_msr == NULL) { 3688 error = ENOSYS; 3689 break; 3690 } 3691 3692 if ((error = (*pcd->pcd_get_msr)(adjri, &gm.pm_msr)) < 0) 3693 break; 3694 3695 if ((error = copyout(&gm, arg, sizeof(gm))) < 0) 3696 break; 3697 3698 /* 3699 * Mark our process as using MSRs. Update machine 3700 * state using a forced context switch. 3701 */ 3702 3703 pt->pt_process->pp_flags |= PMC_PP_ENABLE_MSR_ACCESS; 3704 pmc_force_context_switch(); 3705 3706 } 3707 break; 3708 3709 /* 3710 * Release an allocated PMC 3711 */ 3712 3713 case PMC_OP_PMCRELEASE: 3714 { 3715 pmc_id_t pmcid; 3716 struct pmc *pm; 3717 struct pmc_owner *po; 3718 struct pmc_op_simple sp; 3719 3720 /* 3721 * Find PMC pointer for the named PMC. 3722 * 3723 * Use pmc_release_pmc_descriptor() to switch off the 3724 * PMC, remove all its target threads, and remove the 3725 * PMC from its owner's list. 3726 * 3727 * Remove the owner record if this is the last PMC 3728 * owned. 3729 * 3730 * Free up space. 3731 */ 3732 3733 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3734 break; 3735 3736 pmcid = sp.pm_pmcid; 3737 3738 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3739 break; 3740 3741 po = pm->pm_owner; 3742 pmc_release_pmc_descriptor(pm); 3743 pmc_maybe_remove_owner(po); 3744 3745 free(pm, M_PMC); 3746 } 3747 break; 3748 3749 3750 /* 3751 * Read and/or write a PMC. 3752 */ 3753 3754 case PMC_OP_PMCRW: 3755 { 3756 int adjri; 3757 struct pmc *pm; 3758 uint32_t cpu, ri; 3759 pmc_value_t oldvalue; 3760 struct pmc_binding pb; 3761 struct pmc_op_pmcrw prw; 3762 struct pmc_classdep *pcd; 3763 struct pmc_op_pmcrw *pprw; 3764 3765 PMC_DOWNGRADE_SX(); 3766 3767 if ((error = copyin(arg, &prw, sizeof(prw))) != 0) 3768 break; 3769 3770 ri = 0; 3771 PMCDBG(PMC,OPS,1, "rw id=%d flags=0x%x", prw.pm_pmcid, 3772 prw.pm_flags); 3773 3774 /* must have at least one flag set */ 3775 if ((prw.pm_flags & (PMC_F_OLDVALUE|PMC_F_NEWVALUE)) == 0) { 3776 error = EINVAL; 3777 break; 3778 } 3779 3780 /* locate pmc descriptor */ 3781 if ((error = pmc_find_pmc(prw.pm_pmcid, &pm)) != 0) 3782 break; 3783 3784 /* Can't read a PMC that hasn't been started. */ 3785 if (pm->pm_state != PMC_STATE_ALLOCATED && 3786 pm->pm_state != PMC_STATE_STOPPED && 3787 pm->pm_state != PMC_STATE_RUNNING) { 3788 error = EINVAL; 3789 break; 3790 } 3791 3792 /* writing a new value is allowed only for 'STOPPED' pmcs */ 3793 if (pm->pm_state == PMC_STATE_RUNNING && 3794 (prw.pm_flags & PMC_F_NEWVALUE)) { 3795 error = EBUSY; 3796 break; 3797 } 3798 3799 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) { 3800 3801 /* 3802 * If this PMC is attached to its owner (i.e., 3803 * the process requesting this operation) and 3804 * is running, then attempt to get an 3805 * upto-date reading from hardware for a READ. 3806 * Writes are only allowed when the PMC is 3807 * stopped, so only update the saved value 3808 * field. 3809 * 3810 * If the PMC is not running, or is not 3811 * attached to its owner, read/write to the 3812 * savedvalue field. 3813 */ 3814 3815 ri = PMC_TO_ROWINDEX(pm); 3816 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3817 3818 mtx_pool_lock_spin(pmc_mtxpool, pm); 3819 cpu = curthread->td_oncpu; 3820 3821 if (prw.pm_flags & PMC_F_OLDVALUE) { 3822 if ((pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) && 3823 (pm->pm_state == PMC_STATE_RUNNING)) 3824 error = (*pcd->pcd_read_pmc)(cpu, adjri, 3825 &oldvalue); 3826 else 3827 oldvalue = pm->pm_gv.pm_savedvalue; 3828 } 3829 if (prw.pm_flags & PMC_F_NEWVALUE) 3830 pm->pm_gv.pm_savedvalue = prw.pm_value; 3831 3832 mtx_pool_unlock_spin(pmc_mtxpool, pm); 3833 3834 } else { /* System mode PMCs */ 3835 cpu = PMC_TO_CPU(pm); 3836 ri = PMC_TO_ROWINDEX(pm); 3837 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3838 3839 if (!pmc_cpu_is_active(cpu)) { 3840 error = ENXIO; 3841 break; 3842 } 3843 3844 /* move this thread to CPU 'cpu' */ 3845 pmc_save_cpu_binding(&pb); 3846 pmc_select_cpu(cpu); 3847 3848 critical_enter(); 3849 /* save old value */ 3850 if (prw.pm_flags & PMC_F_OLDVALUE) 3851 if ((error = (*pcd->pcd_read_pmc)(cpu, adjri, 3852 &oldvalue))) 3853 goto error; 3854 /* write out new value */ 3855 if (prw.pm_flags & PMC_F_NEWVALUE) 3856 error = (*pcd->pcd_write_pmc)(cpu, adjri, 3857 prw.pm_value); 3858 error: 3859 critical_exit(); 3860 pmc_restore_cpu_binding(&pb); 3861 if (error) 3862 break; 3863 } 3864 3865 pprw = (struct pmc_op_pmcrw *) arg; 3866 3867 #ifdef DEBUG 3868 if (prw.pm_flags & PMC_F_NEWVALUE) 3869 PMCDBG(PMC,OPS,2, "rw id=%d new %jx -> old %jx", 3870 ri, prw.pm_value, oldvalue); 3871 else if (prw.pm_flags & PMC_F_OLDVALUE) 3872 PMCDBG(PMC,OPS,2, "rw id=%d -> old %jx", ri, oldvalue); 3873 #endif 3874 3875 /* return old value if requested */ 3876 if (prw.pm_flags & PMC_F_OLDVALUE) 3877 if ((error = copyout(&oldvalue, &pprw->pm_value, 3878 sizeof(prw.pm_value)))) 3879 break; 3880 3881 } 3882 break; 3883 3884 3885 /* 3886 * Set the sampling rate for a sampling mode PMC and the 3887 * initial count for a counting mode PMC. 3888 */ 3889 3890 case PMC_OP_PMCSETCOUNT: 3891 { 3892 struct pmc *pm; 3893 struct pmc_op_pmcsetcount sc; 3894 3895 PMC_DOWNGRADE_SX(); 3896 3897 if ((error = copyin(arg, &sc, sizeof(sc))) != 0) 3898 break; 3899 3900 if ((error = pmc_find_pmc(sc.pm_pmcid, &pm)) != 0) 3901 break; 3902 3903 if (pm->pm_state == PMC_STATE_RUNNING) { 3904 error = EBUSY; 3905 break; 3906 } 3907 3908 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 3909 pm->pm_sc.pm_reloadcount = sc.pm_count; 3910 else 3911 pm->pm_sc.pm_initial = sc.pm_count; 3912 } 3913 break; 3914 3915 3916 /* 3917 * Start a PMC. 3918 */ 3919 3920 case PMC_OP_PMCSTART: 3921 { 3922 pmc_id_t pmcid; 3923 struct pmc *pm; 3924 struct pmc_op_simple sp; 3925 3926 sx_assert(&pmc_sx, SX_XLOCKED); 3927 3928 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3929 break; 3930 3931 pmcid = sp.pm_pmcid; 3932 3933 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3934 break; 3935 3936 KASSERT(pmcid == pm->pm_id, 3937 ("[pmc,%d] pmcid %x != id %x", __LINE__, 3938 pm->pm_id, pmcid)); 3939 3940 if (pm->pm_state == PMC_STATE_RUNNING) /* already running */ 3941 break; 3942 else if (pm->pm_state != PMC_STATE_STOPPED && 3943 pm->pm_state != PMC_STATE_ALLOCATED) { 3944 error = EINVAL; 3945 break; 3946 } 3947 3948 error = pmc_start(pm); 3949 } 3950 break; 3951 3952 3953 /* 3954 * Stop a PMC. 3955 */ 3956 3957 case PMC_OP_PMCSTOP: 3958 { 3959 pmc_id_t pmcid; 3960 struct pmc *pm; 3961 struct pmc_op_simple sp; 3962 3963 PMC_DOWNGRADE_SX(); 3964 3965 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3966 break; 3967 3968 pmcid = sp.pm_pmcid; 3969 3970 /* 3971 * Mark the PMC as inactive and invoke the MD stop 3972 * routines if needed. 3973 */ 3974 3975 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3976 break; 3977 3978 KASSERT(pmcid == pm->pm_id, 3979 ("[pmc,%d] pmc id %x != pmcid %x", __LINE__, 3980 pm->pm_id, pmcid)); 3981 3982 if (pm->pm_state == PMC_STATE_STOPPED) /* already stopped */ 3983 break; 3984 else if (pm->pm_state != PMC_STATE_RUNNING) { 3985 error = EINVAL; 3986 break; 3987 } 3988 3989 error = pmc_stop(pm); 3990 } 3991 break; 3992 3993 3994 /* 3995 * Write a user supplied value to the log file. 3996 */ 3997 3998 case PMC_OP_WRITELOG: 3999 { 4000 struct pmc_op_writelog wl; 4001 struct pmc_owner *po; 4002 4003 PMC_DOWNGRADE_SX(); 4004 4005 if ((error = copyin(arg, &wl, sizeof(wl))) != 0) 4006 break; 4007 4008 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 4009 error = EINVAL; 4010 break; 4011 } 4012 4013 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) { 4014 error = EINVAL; 4015 break; 4016 } 4017 4018 error = pmclog_process_userlog(po, &wl); 4019 } 4020 break; 4021 4022 4023 default: 4024 error = EINVAL; 4025 break; 4026 } 4027 4028 if (is_sx_locked != 0) { 4029 if (is_sx_downgraded) 4030 sx_sunlock(&pmc_sx); 4031 else 4032 sx_xunlock(&pmc_sx); 4033 } 4034 4035 if (error) 4036 atomic_add_int(&pmc_stats.pm_syscall_errors, 1); 4037 4038 PICKUP_GIANT(); 4039 4040 return error; 4041 } 4042 4043 /* 4044 * Helper functions 4045 */ 4046 4047 4048 /* 4049 * Mark the thread as needing callchain capture and post an AST. The 4050 * actual callchain capture will be done in a context where it is safe 4051 * to take page faults. 4052 */ 4053 4054 static void 4055 pmc_post_callchain_callback(void) 4056 { 4057 struct thread *td; 4058 4059 td = curthread; 4060 4061 /* 4062 * If there is multiple PMCs for the same interrupt ignore new post 4063 */ 4064 if (td->td_pflags & TDP_CALLCHAIN) 4065 return; 4066 4067 /* 4068 * Mark this thread as needing callchain capture. 4069 * `td->td_pflags' will be safe to touch because this thread 4070 * was in user space when it was interrupted. 4071 */ 4072 td->td_pflags |= TDP_CALLCHAIN; 4073 4074 /* 4075 * Don't let this thread migrate between CPUs until callchain 4076 * capture completes. 4077 */ 4078 sched_pin(); 4079 4080 return; 4081 } 4082 4083 /* 4084 * Interrupt processing. 4085 * 4086 * Find a free slot in the per-cpu array of samples and capture the 4087 * current callchain there. If a sample was successfully added, a bit 4088 * is set in mask 'pmc_cpumask' denoting that the DO_SAMPLES hook 4089 * needs to be invoked from the clock handler. 4090 * 4091 * This function is meant to be called from an NMI handler. It cannot 4092 * use any of the locking primitives supplied by the OS. 4093 */ 4094 4095 int 4096 pmc_process_interrupt(int cpu, int ring, struct pmc *pm, struct trapframe *tf, 4097 int inuserspace) 4098 { 4099 int error, callchaindepth; 4100 struct thread *td; 4101 struct pmc_sample *ps; 4102 struct pmc_samplebuffer *psb; 4103 4104 error = 0; 4105 4106 /* 4107 * Allocate space for a sample buffer. 4108 */ 4109 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4110 4111 ps = psb->ps_write; 4112 if (ps->ps_nsamples) { /* in use, reader hasn't caught up */ 4113 pm->pm_stalled = 1; 4114 atomic_add_int(&pmc_stats.pm_intr_bufferfull, 1); 4115 PMCDBG(SAM,INT,1,"(spc) cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", 4116 cpu, pm, (void *) tf, inuserspace, 4117 (int) (psb->ps_write - psb->ps_samples), 4118 (int) (psb->ps_read - psb->ps_samples)); 4119 error = ENOMEM; 4120 goto done; 4121 } 4122 4123 4124 /* Fill in entry. */ 4125 PMCDBG(SAM,INT,1,"cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", cpu, pm, 4126 (void *) tf, inuserspace, 4127 (int) (psb->ps_write - psb->ps_samples), 4128 (int) (psb->ps_read - psb->ps_samples)); 4129 4130 KASSERT(pm->pm_runcount >= 0, 4131 ("[pmc,%d] pm=%p runcount %d", __LINE__, (void *) pm, 4132 pm->pm_runcount)); 4133 4134 atomic_add_rel_int(&pm->pm_runcount, 1); /* hold onto PMC */ 4135 4136 ps->ps_pmc = pm; 4137 if ((td = curthread) && td->td_proc) 4138 ps->ps_pid = td->td_proc->p_pid; 4139 else 4140 ps->ps_pid = -1; 4141 ps->ps_cpu = cpu; 4142 ps->ps_td = td; 4143 ps->ps_flags = inuserspace ? PMC_CC_F_USERSPACE : 0; 4144 4145 callchaindepth = (pm->pm_flags & PMC_F_CALLCHAIN) ? 4146 pmc_callchaindepth : 1; 4147 4148 if (callchaindepth == 1) 4149 ps->ps_pc[0] = PMC_TRAPFRAME_TO_PC(tf); 4150 else { 4151 /* 4152 * Kernel stack traversals can be done immediately, 4153 * while we defer to an AST for user space traversals. 4154 */ 4155 if (!inuserspace) { 4156 callchaindepth = 4157 pmc_save_kernel_callchain(ps->ps_pc, 4158 callchaindepth, tf); 4159 } else { 4160 pmc_post_callchain_callback(); 4161 callchaindepth = PMC_SAMPLE_INUSE; 4162 } 4163 } 4164 4165 ps->ps_nsamples = callchaindepth; /* mark entry as in use */ 4166 4167 /* increment write pointer, modulo ring buffer size */ 4168 ps++; 4169 if (ps == psb->ps_fence) 4170 psb->ps_write = psb->ps_samples; 4171 else 4172 psb->ps_write = ps; 4173 4174 done: 4175 /* mark CPU as needing processing */ 4176 CPU_SET_ATOMIC(cpu, &pmc_cpumask); 4177 4178 return (error); 4179 } 4180 4181 /* 4182 * Capture a user call chain. This function will be called from ast() 4183 * before control returns to userland and before the process gets 4184 * rescheduled. 4185 */ 4186 4187 static void 4188 pmc_capture_user_callchain(int cpu, int ring, struct trapframe *tf) 4189 { 4190 int i; 4191 struct pmc *pm; 4192 struct thread *td; 4193 struct pmc_sample *ps; 4194 struct pmc_samplebuffer *psb; 4195 #ifdef INVARIANTS 4196 int ncallchains; 4197 #endif 4198 4199 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4200 td = curthread; 4201 4202 KASSERT(td->td_pflags & TDP_CALLCHAIN, 4203 ("[pmc,%d] Retrieving callchain for thread that doesn't want it", 4204 __LINE__)); 4205 4206 #ifdef INVARIANTS 4207 ncallchains = 0; 4208 #endif 4209 4210 /* 4211 * Iterate through all deferred callchain requests. 4212 */ 4213 4214 ps = psb->ps_samples; 4215 for (i = 0; i < pmc_nsamples; i++, ps++) { 4216 4217 if (ps->ps_nsamples != PMC_SAMPLE_INUSE) 4218 continue; 4219 if (ps->ps_td != td) 4220 continue; 4221 4222 KASSERT(ps->ps_cpu == cpu, 4223 ("[pmc,%d] cpu mismatch ps_cpu=%d pcpu=%d", __LINE__, 4224 ps->ps_cpu, PCPU_GET(cpuid))); 4225 4226 pm = ps->ps_pmc; 4227 4228 KASSERT(pm->pm_flags & PMC_F_CALLCHAIN, 4229 ("[pmc,%d] Retrieving callchain for PMC that doesn't " 4230 "want it", __LINE__)); 4231 4232 KASSERT(pm->pm_runcount > 0, 4233 ("[pmc,%d] runcount %d", __LINE__, pm->pm_runcount)); 4234 4235 /* 4236 * Retrieve the callchain and mark the sample buffer 4237 * as 'processable' by the timer tick sweep code. 4238 */ 4239 ps->ps_nsamples = pmc_save_user_callchain(ps->ps_pc, 4240 pmc_callchaindepth, tf); 4241 4242 #ifdef INVARIANTS 4243 ncallchains++; 4244 #endif 4245 } 4246 4247 KASSERT(ncallchains > 0, 4248 ("[pmc,%d] cpu %d didn't find a sample to collect", __LINE__, 4249 cpu)); 4250 4251 KASSERT(td->td_pinned > 0, 4252 ("[pmc,%d] invalid td_pinned value", __LINE__)); 4253 sched_unpin(); /* Can migrate safely now. */ 4254 4255 return; 4256 } 4257 4258 /* 4259 * Process saved PC samples. 4260 */ 4261 4262 static void 4263 pmc_process_samples(int cpu, int ring) 4264 { 4265 struct pmc *pm; 4266 int adjri, n; 4267 struct thread *td; 4268 struct pmc_owner *po; 4269 struct pmc_sample *ps; 4270 struct pmc_classdep *pcd; 4271 struct pmc_samplebuffer *psb; 4272 4273 KASSERT(PCPU_GET(cpuid) == cpu, 4274 ("[pmc,%d] not on the correct CPU pcpu=%d cpu=%d", __LINE__, 4275 PCPU_GET(cpuid), cpu)); 4276 4277 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4278 4279 for (n = 0; n < pmc_nsamples; n++) { /* bound on #iterations */ 4280 4281 ps = psb->ps_read; 4282 if (ps->ps_nsamples == PMC_SAMPLE_FREE) 4283 break; 4284 4285 pm = ps->ps_pmc; 4286 4287 KASSERT(pm->pm_runcount > 0, 4288 ("[pmc,%d] pm=%p runcount %d", __LINE__, (void *) pm, 4289 pm->pm_runcount)); 4290 4291 po = pm->pm_owner; 4292 4293 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 4294 ("[pmc,%d] pmc=%p non-sampling mode=%d", __LINE__, 4295 pm, PMC_TO_MODE(pm))); 4296 4297 /* Ignore PMCs that have been switched off */ 4298 if (pm->pm_state != PMC_STATE_RUNNING) 4299 goto entrydone; 4300 4301 /* If there is a pending AST wait for completion */ 4302 if (ps->ps_nsamples == PMC_SAMPLE_INUSE) { 4303 /* Need a rescan at a later time. */ 4304 CPU_SET_ATOMIC(cpu, &pmc_cpumask); 4305 break; 4306 } 4307 4308 PMCDBG(SAM,OPS,1,"cpu=%d pm=%p n=%d fl=%x wr=%d rd=%d", cpu, 4309 pm, ps->ps_nsamples, ps->ps_flags, 4310 (int) (psb->ps_write - psb->ps_samples), 4311 (int) (psb->ps_read - psb->ps_samples)); 4312 4313 /* 4314 * If this is a process-mode PMC that is attached to 4315 * its owner, and if the PC is in user mode, update 4316 * profiling statistics like timer-based profiling 4317 * would have done. 4318 */ 4319 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) { 4320 if (ps->ps_flags & PMC_CC_F_USERSPACE) { 4321 td = FIRST_THREAD_IN_PROC(po->po_owner); 4322 addupc_intr(td, ps->ps_pc[0], 1); 4323 } 4324 goto entrydone; 4325 } 4326 4327 /* 4328 * Otherwise, this is either a sampling mode PMC that 4329 * is attached to a different process than its owner, 4330 * or a system-wide sampling PMC. Dispatch a log 4331 * entry to the PMC's owner process. 4332 */ 4333 pmclog_process_callchain(pm, ps); 4334 4335 entrydone: 4336 ps->ps_nsamples = 0; /* mark entry as free */ 4337 atomic_subtract_rel_int(&pm->pm_runcount, 1); 4338 4339 /* increment read pointer, modulo sample size */ 4340 if (++ps == psb->ps_fence) 4341 psb->ps_read = psb->ps_samples; 4342 else 4343 psb->ps_read = ps; 4344 } 4345 4346 atomic_add_int(&pmc_stats.pm_log_sweeps, 1); 4347 4348 /* Do not re-enable stalled PMCs if we failed to process any samples */ 4349 if (n == 0) 4350 return; 4351 4352 /* 4353 * Restart any stalled sampling PMCs on this CPU. 4354 * 4355 * If the NMI handler sets the pm_stalled field of a PMC after 4356 * the check below, we'll end up processing the stalled PMC at 4357 * the next hardclock tick. 4358 */ 4359 for (n = 0; n < md->pmd_npmc; n++) { 4360 pcd = pmc_ri_to_classdep(md, n, &adjri); 4361 KASSERT(pcd != NULL, 4362 ("[pmc,%d] null pcd ri=%d", __LINE__, n)); 4363 (void) (*pcd->pcd_get_config)(cpu,adjri,&pm); 4364 4365 if (pm == NULL || /* !cfg'ed */ 4366 pm->pm_state != PMC_STATE_RUNNING || /* !active */ 4367 !PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) || /* !sampling */ 4368 pm->pm_stalled == 0) /* !stalled */ 4369 continue; 4370 4371 pm->pm_stalled = 0; 4372 (*pcd->pcd_start_pmc)(cpu, adjri); 4373 } 4374 } 4375 4376 /* 4377 * Event handlers. 4378 */ 4379 4380 /* 4381 * Handle a process exit. 4382 * 4383 * Remove this process from all hash tables. If this process 4384 * owned any PMCs, turn off those PMCs and deallocate them, 4385 * removing any associations with target processes. 4386 * 4387 * This function will be called by the last 'thread' of a 4388 * process. 4389 * 4390 * XXX This eventhandler gets called early in the exit process. 4391 * Consider using a 'hook' invocation from thread_exit() or equivalent 4392 * spot. Another negative is that kse_exit doesn't seem to call 4393 * exit1() [??]. 4394 * 4395 */ 4396 4397 static void 4398 pmc_process_exit(void *arg __unused, struct proc *p) 4399 { 4400 struct pmc *pm; 4401 int adjri, cpu; 4402 unsigned int ri; 4403 int is_using_hwpmcs; 4404 struct pmc_owner *po; 4405 struct pmc_process *pp; 4406 struct pmc_classdep *pcd; 4407 pmc_value_t newvalue, tmp; 4408 4409 PROC_LOCK(p); 4410 is_using_hwpmcs = p->p_flag & P_HWPMC; 4411 PROC_UNLOCK(p); 4412 4413 /* 4414 * Log a sysexit event to all SS PMC owners. 4415 */ 4416 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4417 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4418 pmclog_process_sysexit(po, p->p_pid); 4419 4420 if (!is_using_hwpmcs) 4421 return; 4422 4423 PMC_GET_SX_XLOCK(); 4424 PMCDBG(PRC,EXT,1,"process-exit proc=%p (%d, %s)", p, p->p_pid, 4425 p->p_comm); 4426 4427 /* 4428 * Since this code is invoked by the last thread in an exiting 4429 * process, we would have context switched IN at some prior 4430 * point. However, with PREEMPTION, kernel mode context 4431 * switches may happen any time, so we want to disable a 4432 * context switch OUT till we get any PMCs targetting this 4433 * process off the hardware. 4434 * 4435 * We also need to atomically remove this process' 4436 * entry from our target process hash table, using 4437 * PMC_FLAG_REMOVE. 4438 */ 4439 PMCDBG(PRC,EXT,1, "process-exit proc=%p (%d, %s)", p, p->p_pid, 4440 p->p_comm); 4441 4442 critical_enter(); /* no preemption */ 4443 4444 cpu = curthread->td_oncpu; 4445 4446 if ((pp = pmc_find_process_descriptor(p, 4447 PMC_FLAG_REMOVE)) != NULL) { 4448 4449 PMCDBG(PRC,EXT,2, 4450 "process-exit proc=%p pmc-process=%p", p, pp); 4451 4452 /* 4453 * The exiting process could the target of 4454 * some PMCs which will be running on 4455 * currently executing CPU. 4456 * 4457 * We need to turn these PMCs off like we 4458 * would do at context switch OUT time. 4459 */ 4460 for (ri = 0; ri < md->pmd_npmc; ri++) { 4461 4462 /* 4463 * Pick up the pmc pointer from hardware 4464 * state similar to the CSW_OUT code. 4465 */ 4466 pm = NULL; 4467 4468 pcd = pmc_ri_to_classdep(md, ri, &adjri); 4469 4470 (void) (*pcd->pcd_get_config)(cpu, adjri, &pm); 4471 4472 PMCDBG(PRC,EXT,2, "ri=%d pm=%p", ri, pm); 4473 4474 if (pm == NULL || 4475 !PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 4476 continue; 4477 4478 PMCDBG(PRC,EXT,2, "ppmcs[%d]=%p pm=%p " 4479 "state=%d", ri, pp->pp_pmcs[ri].pp_pmc, 4480 pm, pm->pm_state); 4481 4482 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 4483 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 4484 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 4485 4486 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 4487 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", 4488 __LINE__, pm, ri, pp->pp_pmcs[ri].pp_pmc)); 4489 4490 (void) pcd->pcd_stop_pmc(cpu, adjri); 4491 4492 KASSERT(pm->pm_runcount > 0, 4493 ("[pmc,%d] bad runcount ri %d rc %d", 4494 __LINE__, ri, pm->pm_runcount)); 4495 4496 /* Stop hardware only if it is actually running */ 4497 if (pm->pm_state == PMC_STATE_RUNNING && 4498 pm->pm_stalled == 0) { 4499 pcd->pcd_read_pmc(cpu, adjri, &newvalue); 4500 tmp = newvalue - 4501 PMC_PCPU_SAVED(cpu,ri); 4502 4503 mtx_pool_lock_spin(pmc_mtxpool, pm); 4504 pm->pm_gv.pm_savedvalue += tmp; 4505 pp->pp_pmcs[ri].pp_pmcval += tmp; 4506 mtx_pool_unlock_spin(pmc_mtxpool, pm); 4507 } 4508 4509 atomic_subtract_rel_int(&pm->pm_runcount,1); 4510 4511 KASSERT((int) pm->pm_runcount >= 0, 4512 ("[pmc,%d] runcount is %d", __LINE__, ri)); 4513 4514 (void) pcd->pcd_config_pmc(cpu, adjri, NULL); 4515 } 4516 4517 /* 4518 * Inform the MD layer of this pseudo "context switch 4519 * out" 4520 */ 4521 (void) md->pmd_switch_out(pmc_pcpu[cpu], pp); 4522 4523 critical_exit(); /* ok to be pre-empted now */ 4524 4525 /* 4526 * Unlink this process from the PMCs that are 4527 * targetting it. This will send a signal to 4528 * all PMC owner's whose PMCs are orphaned. 4529 * 4530 * Log PMC value at exit time if requested. 4531 */ 4532 for (ri = 0; ri < md->pmd_npmc; ri++) 4533 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 4534 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 4535 PMC_IS_COUNTING_MODE(PMC_TO_MODE(pm))) 4536 pmclog_process_procexit(pm, pp); 4537 pmc_unlink_target_process(pm, pp); 4538 } 4539 free(pp, M_PMC); 4540 4541 } else 4542 critical_exit(); /* pp == NULL */ 4543 4544 4545 /* 4546 * If the process owned PMCs, free them up and free up 4547 * memory. 4548 */ 4549 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 4550 pmc_remove_owner(po); 4551 pmc_destroy_owner_descriptor(po); 4552 } 4553 4554 sx_xunlock(&pmc_sx); 4555 } 4556 4557 /* 4558 * Handle a process fork. 4559 * 4560 * If the parent process 'p1' is under HWPMC monitoring, then copy 4561 * over any attached PMCs that have 'do_descendants' semantics. 4562 */ 4563 4564 static void 4565 pmc_process_fork(void *arg __unused, struct proc *p1, struct proc *newproc, 4566 int flags) 4567 { 4568 int is_using_hwpmcs; 4569 unsigned int ri; 4570 uint32_t do_descendants; 4571 struct pmc *pm; 4572 struct pmc_owner *po; 4573 struct pmc_process *ppnew, *ppold; 4574 4575 (void) flags; /* unused parameter */ 4576 4577 PROC_LOCK(p1); 4578 is_using_hwpmcs = p1->p_flag & P_HWPMC; 4579 PROC_UNLOCK(p1); 4580 4581 /* 4582 * If there are system-wide sampling PMCs active, we need to 4583 * log all fork events to their owner's logs. 4584 */ 4585 4586 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4587 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4588 pmclog_process_procfork(po, p1->p_pid, newproc->p_pid); 4589 4590 if (!is_using_hwpmcs) 4591 return; 4592 4593 PMC_GET_SX_XLOCK(); 4594 PMCDBG(PMC,FRK,1, "process-fork proc=%p (%d, %s) -> %p", p1, 4595 p1->p_pid, p1->p_comm, newproc); 4596 4597 /* 4598 * If the parent process (curthread->td_proc) is a 4599 * target of any PMCs, look for PMCs that are to be 4600 * inherited, and link these into the new process 4601 * descriptor. 4602 */ 4603 if ((ppold = pmc_find_process_descriptor(curthread->td_proc, 4604 PMC_FLAG_NONE)) == NULL) 4605 goto done; /* nothing to do */ 4606 4607 do_descendants = 0; 4608 for (ri = 0; ri < md->pmd_npmc; ri++) 4609 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL) 4610 do_descendants |= pm->pm_flags & PMC_F_DESCENDANTS; 4611 if (do_descendants == 0) /* nothing to do */ 4612 goto done; 4613 4614 /* allocate a descriptor for the new process */ 4615 if ((ppnew = pmc_find_process_descriptor(newproc, 4616 PMC_FLAG_ALLOCATE)) == NULL) 4617 goto done; 4618 4619 /* 4620 * Run through all PMCs that were targeting the old process 4621 * and which specified F_DESCENDANTS and attach them to the 4622 * new process. 4623 * 4624 * Log the fork event to all owners of PMCs attached to this 4625 * process, if not already logged. 4626 */ 4627 for (ri = 0; ri < md->pmd_npmc; ri++) 4628 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL && 4629 (pm->pm_flags & PMC_F_DESCENDANTS)) { 4630 pmc_link_target_process(pm, ppnew); 4631 po = pm->pm_owner; 4632 if (po->po_sscount == 0 && 4633 po->po_flags & PMC_PO_OWNS_LOGFILE) 4634 pmclog_process_procfork(po, p1->p_pid, 4635 newproc->p_pid); 4636 } 4637 4638 /* 4639 * Now mark the new process as being tracked by this driver. 4640 */ 4641 PROC_LOCK(newproc); 4642 newproc->p_flag |= P_HWPMC; 4643 PROC_UNLOCK(newproc); 4644 4645 done: 4646 sx_xunlock(&pmc_sx); 4647 } 4648 4649 4650 /* 4651 * initialization 4652 */ 4653 4654 static const char *pmc_name_of_pmcclass[] = { 4655 #undef __PMC_CLASS 4656 #define __PMC_CLASS(N) #N , 4657 __PMC_CLASSES() 4658 }; 4659 4660 /* 4661 * Base class initializer: allocate structure and set default classes. 4662 */ 4663 struct pmc_mdep * 4664 pmc_mdep_alloc(int nclasses) 4665 { 4666 struct pmc_mdep *md; 4667 int n; 4668 4669 /* SOFT + md classes */ 4670 n = 1 + nclasses; 4671 md = malloc(sizeof(struct pmc_mdep) + n * 4672 sizeof(struct pmc_classdep), M_PMC, M_WAITOK|M_ZERO); 4673 if (md != NULL) { 4674 md->pmd_nclass = n; 4675 4676 /* Add base class. */ 4677 pmc_soft_initialize(md); 4678 } 4679 4680 return md; 4681 } 4682 4683 void 4684 pmc_mdep_free(struct pmc_mdep *md) 4685 { 4686 pmc_soft_finalize(md); 4687 free(md, M_PMC); 4688 } 4689 4690 static int 4691 generic_switch_in(struct pmc_cpu *pc, struct pmc_process *pp) 4692 { 4693 (void) pc; (void) pp; 4694 4695 return (0); 4696 } 4697 4698 static int 4699 generic_switch_out(struct pmc_cpu *pc, struct pmc_process *pp) 4700 { 4701 (void) pc; (void) pp; 4702 4703 return (0); 4704 } 4705 4706 static struct pmc_mdep * 4707 pmc_generic_cpu_initialize(void) 4708 { 4709 struct pmc_mdep *md; 4710 4711 md = pmc_mdep_alloc(0); 4712 4713 md->pmd_cputype = PMC_CPU_GENERIC; 4714 4715 md->pmd_pcpu_init = NULL; 4716 md->pmd_pcpu_fini = NULL; 4717 md->pmd_switch_in = generic_switch_in; 4718 md->pmd_switch_out = generic_switch_out; 4719 4720 return (md); 4721 } 4722 4723 static void 4724 pmc_generic_cpu_finalize(struct pmc_mdep *md) 4725 { 4726 (void) md; 4727 } 4728 4729 4730 static int 4731 pmc_initialize(void) 4732 { 4733 int c, cpu, error, n, ri; 4734 unsigned int maxcpu; 4735 struct pmc_binding pb; 4736 struct pmc_sample *ps; 4737 struct pmc_classdep *pcd; 4738 struct pmc_samplebuffer *sb; 4739 4740 md = NULL; 4741 error = 0; 4742 4743 #ifdef DEBUG 4744 /* parse debug flags first */ 4745 if (TUNABLE_STR_FETCH(PMC_SYSCTL_NAME_PREFIX "debugflags", 4746 pmc_debugstr, sizeof(pmc_debugstr))) 4747 pmc_debugflags_parse(pmc_debugstr, 4748 pmc_debugstr+strlen(pmc_debugstr)); 4749 #endif 4750 4751 PMCDBG(MOD,INI,0, "PMC Initialize (version %x)", PMC_VERSION); 4752 4753 /* check kernel version */ 4754 if (pmc_kernel_version != PMC_VERSION) { 4755 if (pmc_kernel_version == 0) 4756 printf("hwpmc: this kernel has not been compiled with " 4757 "'options HWPMC_HOOKS'.\n"); 4758 else 4759 printf("hwpmc: kernel version (0x%x) does not match " 4760 "module version (0x%x).\n", pmc_kernel_version, 4761 PMC_VERSION); 4762 return EPROGMISMATCH; 4763 } 4764 4765 /* 4766 * check sysctl parameters 4767 */ 4768 4769 if (pmc_hashsize <= 0) { 4770 (void) printf("hwpmc: tunable \"hashsize\"=%d must be " 4771 "greater than zero.\n", pmc_hashsize); 4772 pmc_hashsize = PMC_HASH_SIZE; 4773 } 4774 4775 if (pmc_nsamples <= 0 || pmc_nsamples > 65535) { 4776 (void) printf("hwpmc: tunable \"nsamples\"=%d out of " 4777 "range.\n", pmc_nsamples); 4778 pmc_nsamples = PMC_NSAMPLES; 4779 } 4780 4781 if (pmc_callchaindepth <= 0 || 4782 pmc_callchaindepth > PMC_CALLCHAIN_DEPTH_MAX) { 4783 (void) printf("hwpmc: tunable \"callchaindepth\"=%d out of " 4784 "range.\n", pmc_callchaindepth); 4785 pmc_callchaindepth = PMC_CALLCHAIN_DEPTH; 4786 } 4787 4788 md = pmc_md_initialize(); 4789 if (md == NULL) { 4790 /* Default to generic CPU. */ 4791 md = pmc_generic_cpu_initialize(); 4792 if (md == NULL) 4793 return (ENOSYS); 4794 } 4795 4796 KASSERT(md->pmd_nclass >= 1 && md->pmd_npmc >= 1, 4797 ("[pmc,%d] no classes or pmcs", __LINE__)); 4798 4799 /* Compute the map from row-indices to classdep pointers. */ 4800 pmc_rowindex_to_classdep = malloc(sizeof(struct pmc_classdep *) * 4801 md->pmd_npmc, M_PMC, M_WAITOK|M_ZERO); 4802 4803 for (n = 0; n < md->pmd_npmc; n++) 4804 pmc_rowindex_to_classdep[n] = NULL; 4805 for (ri = c = 0; c < md->pmd_nclass; c++) { 4806 pcd = &md->pmd_classdep[c]; 4807 for (n = 0; n < pcd->pcd_num; n++, ri++) 4808 pmc_rowindex_to_classdep[ri] = pcd; 4809 } 4810 4811 KASSERT(ri == md->pmd_npmc, 4812 ("[pmc,%d] npmc miscomputed: ri=%d, md->npmc=%d", __LINE__, 4813 ri, md->pmd_npmc)); 4814 4815 maxcpu = pmc_cpu_max(); 4816 4817 /* allocate space for the per-cpu array */ 4818 pmc_pcpu = malloc(maxcpu * sizeof(struct pmc_cpu *), M_PMC, 4819 M_WAITOK|M_ZERO); 4820 4821 /* per-cpu 'saved values' for managing process-mode PMCs */ 4822 pmc_pcpu_saved = malloc(sizeof(pmc_value_t) * maxcpu * md->pmd_npmc, 4823 M_PMC, M_WAITOK); 4824 4825 /* Perform CPU-dependent initialization. */ 4826 pmc_save_cpu_binding(&pb); 4827 error = 0; 4828 for (cpu = 0; error == 0 && cpu < maxcpu; cpu++) { 4829 if (!pmc_cpu_is_active(cpu)) 4830 continue; 4831 pmc_select_cpu(cpu); 4832 pmc_pcpu[cpu] = malloc(sizeof(struct pmc_cpu) + 4833 md->pmd_npmc * sizeof(struct pmc_hw *), M_PMC, 4834 M_WAITOK|M_ZERO); 4835 if (md->pmd_pcpu_init) 4836 error = md->pmd_pcpu_init(md, cpu); 4837 for (n = 0; error == 0 && n < md->pmd_nclass; n++) 4838 error = md->pmd_classdep[n].pcd_pcpu_init(md, cpu); 4839 } 4840 pmc_restore_cpu_binding(&pb); 4841 4842 if (error) 4843 return (error); 4844 4845 /* allocate space for the sample array */ 4846 for (cpu = 0; cpu < maxcpu; cpu++) { 4847 if (!pmc_cpu_is_active(cpu)) 4848 continue; 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_HR] = sb; 4867 4868 sb = malloc(sizeof(struct pmc_samplebuffer) + 4869 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 4870 M_WAITOK|M_ZERO); 4871 sb->ps_read = sb->ps_write = sb->ps_samples; 4872 sb->ps_fence = sb->ps_samples + pmc_nsamples; 4873 4874 KASSERT(pmc_pcpu[cpu] != NULL, 4875 ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu)); 4876 4877 sb->ps_callchains = malloc(pmc_callchaindepth * pmc_nsamples * 4878 sizeof(uintptr_t), M_PMC, M_WAITOK|M_ZERO); 4879 4880 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 4881 ps->ps_pc = sb->ps_callchains + 4882 (n * pmc_callchaindepth); 4883 4884 pmc_pcpu[cpu]->pc_sb[PMC_SR] = sb; 4885 } 4886 4887 /* allocate space for the row disposition array */ 4888 pmc_pmcdisp = malloc(sizeof(enum pmc_mode) * md->pmd_npmc, 4889 M_PMC, M_WAITOK|M_ZERO); 4890 4891 KASSERT(pmc_pmcdisp != NULL, 4892 ("[pmc,%d] pmcdisp allocation returned NULL", __LINE__)); 4893 4894 /* mark all PMCs as available */ 4895 for (n = 0; n < (int) md->pmd_npmc; n++) 4896 PMC_MARK_ROW_FREE(n); 4897 4898 /* allocate thread hash tables */ 4899 pmc_ownerhash = hashinit(pmc_hashsize, M_PMC, 4900 &pmc_ownerhashmask); 4901 4902 pmc_processhash = hashinit(pmc_hashsize, M_PMC, 4903 &pmc_processhashmask); 4904 mtx_init(&pmc_processhash_mtx, "pmc-process-hash", "pmc-leaf", 4905 MTX_SPIN); 4906 4907 LIST_INIT(&pmc_ss_owners); 4908 pmc_ss_count = 0; 4909 4910 /* allocate a pool of spin mutexes */ 4911 pmc_mtxpool = mtx_pool_create("pmc-leaf", pmc_mtxpool_size, 4912 MTX_SPIN); 4913 4914 PMCDBG(MOD,INI,1, "pmc_ownerhash=%p, mask=0x%lx " 4915 "targethash=%p mask=0x%lx", pmc_ownerhash, pmc_ownerhashmask, 4916 pmc_processhash, pmc_processhashmask); 4917 4918 /* register process {exit,fork,exec} handlers */ 4919 pmc_exit_tag = EVENTHANDLER_REGISTER(process_exit, 4920 pmc_process_exit, NULL, EVENTHANDLER_PRI_ANY); 4921 pmc_fork_tag = EVENTHANDLER_REGISTER(process_fork, 4922 pmc_process_fork, NULL, EVENTHANDLER_PRI_ANY); 4923 4924 /* initialize logging */ 4925 pmclog_initialize(); 4926 4927 /* set hook functions */ 4928 pmc_intr = md->pmd_intr; 4929 pmc_hook = pmc_hook_handler; 4930 4931 if (error == 0) { 4932 printf(PMC_MODULE_NAME ":"); 4933 for (n = 0; n < (int) md->pmd_nclass; n++) { 4934 pcd = &md->pmd_classdep[n]; 4935 printf(" %s/%d/%d/0x%b", 4936 pmc_name_of_pmcclass[pcd->pcd_class], 4937 pcd->pcd_num, 4938 pcd->pcd_width, 4939 pcd->pcd_caps, 4940 "\20" 4941 "\1INT\2USR\3SYS\4EDG\5THR" 4942 "\6REA\7WRI\10INV\11QUA\12PRC" 4943 "\13TAG\14CSC"); 4944 } 4945 printf("\n"); 4946 } 4947 4948 return (error); 4949 } 4950 4951 /* prepare to be unloaded */ 4952 static void 4953 pmc_cleanup(void) 4954 { 4955 int c, cpu; 4956 unsigned int maxcpu; 4957 struct pmc_ownerhash *ph; 4958 struct pmc_owner *po, *tmp; 4959 struct pmc_binding pb; 4960 #ifdef DEBUG 4961 struct pmc_processhash *prh; 4962 #endif 4963 4964 PMCDBG(MOD,INI,0, "%s", "cleanup"); 4965 4966 /* switch off sampling */ 4967 CPU_ZERO(&pmc_cpumask); 4968 pmc_intr = NULL; 4969 4970 sx_xlock(&pmc_sx); 4971 if (pmc_hook == NULL) { /* being unloaded already */ 4972 sx_xunlock(&pmc_sx); 4973 return; 4974 } 4975 4976 pmc_hook = NULL; /* prevent new threads from entering module */ 4977 4978 /* deregister event handlers */ 4979 EVENTHANDLER_DEREGISTER(process_fork, pmc_fork_tag); 4980 EVENTHANDLER_DEREGISTER(process_exit, pmc_exit_tag); 4981 4982 /* send SIGBUS to all owner threads, free up allocations */ 4983 if (pmc_ownerhash) 4984 for (ph = pmc_ownerhash; 4985 ph <= &pmc_ownerhash[pmc_ownerhashmask]; 4986 ph++) { 4987 LIST_FOREACH_SAFE(po, ph, po_next, tmp) { 4988 pmc_remove_owner(po); 4989 4990 /* send SIGBUS to owner processes */ 4991 PMCDBG(MOD,INI,2, "cleanup signal proc=%p " 4992 "(%d, %s)", po->po_owner, 4993 po->po_owner->p_pid, 4994 po->po_owner->p_comm); 4995 4996 PROC_LOCK(po->po_owner); 4997 kern_psignal(po->po_owner, SIGBUS); 4998 PROC_UNLOCK(po->po_owner); 4999 5000 pmc_destroy_owner_descriptor(po); 5001 } 5002 } 5003 5004 /* reclaim allocated data structures */ 5005 if (pmc_mtxpool) 5006 mtx_pool_destroy(&pmc_mtxpool); 5007 5008 mtx_destroy(&pmc_processhash_mtx); 5009 if (pmc_processhash) { 5010 #ifdef DEBUG 5011 struct pmc_process *pp; 5012 5013 PMCDBG(MOD,INI,3, "%s", "destroy process hash"); 5014 for (prh = pmc_processhash; 5015 prh <= &pmc_processhash[pmc_processhashmask]; 5016 prh++) 5017 LIST_FOREACH(pp, prh, pp_next) 5018 PMCDBG(MOD,INI,3, "pid=%d", pp->pp_proc->p_pid); 5019 #endif 5020 5021 hashdestroy(pmc_processhash, M_PMC, pmc_processhashmask); 5022 pmc_processhash = NULL; 5023 } 5024 5025 if (pmc_ownerhash) { 5026 PMCDBG(MOD,INI,3, "%s", "destroy owner hash"); 5027 hashdestroy(pmc_ownerhash, M_PMC, pmc_ownerhashmask); 5028 pmc_ownerhash = NULL; 5029 } 5030 5031 KASSERT(LIST_EMPTY(&pmc_ss_owners), 5032 ("[pmc,%d] Global SS owner list not empty", __LINE__)); 5033 KASSERT(pmc_ss_count == 0, 5034 ("[pmc,%d] Global SS count not empty", __LINE__)); 5035 5036 /* do processor and pmc-class dependent cleanup */ 5037 maxcpu = pmc_cpu_max(); 5038 5039 PMCDBG(MOD,INI,3, "%s", "md cleanup"); 5040 if (md) { 5041 pmc_save_cpu_binding(&pb); 5042 for (cpu = 0; cpu < maxcpu; cpu++) { 5043 PMCDBG(MOD,INI,1,"pmc-cleanup cpu=%d pcs=%p", 5044 cpu, pmc_pcpu[cpu]); 5045 if (!pmc_cpu_is_active(cpu) || pmc_pcpu[cpu] == NULL) 5046 continue; 5047 pmc_select_cpu(cpu); 5048 for (c = 0; c < md->pmd_nclass; c++) 5049 md->pmd_classdep[c].pcd_pcpu_fini(md, cpu); 5050 if (md->pmd_pcpu_fini) 5051 md->pmd_pcpu_fini(md, cpu); 5052 } 5053 5054 if (md->pmd_cputype == PMC_CPU_GENERIC) 5055 pmc_generic_cpu_finalize(md); 5056 else 5057 pmc_md_finalize(md); 5058 5059 pmc_mdep_free(md); 5060 md = NULL; 5061 pmc_restore_cpu_binding(&pb); 5062 } 5063 5064 /* Free per-cpu descriptors. */ 5065 for (cpu = 0; cpu < maxcpu; cpu++) { 5066 if (!pmc_cpu_is_active(cpu)) 5067 continue; 5068 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_HR] != NULL, 5069 ("[pmc,%d] Null hw cpu sample buffer cpu=%d", __LINE__, 5070 cpu)); 5071 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_SR] != NULL, 5072 ("[pmc,%d] Null sw cpu sample buffer cpu=%d", __LINE__, 5073 cpu)); 5074 free(pmc_pcpu[cpu]->pc_sb[PMC_HR]->ps_callchains, M_PMC); 5075 free(pmc_pcpu[cpu]->pc_sb[PMC_HR], M_PMC); 5076 free(pmc_pcpu[cpu]->pc_sb[PMC_SR]->ps_callchains, M_PMC); 5077 free(pmc_pcpu[cpu]->pc_sb[PMC_SR], M_PMC); 5078 free(pmc_pcpu[cpu], M_PMC); 5079 } 5080 5081 free(pmc_pcpu, M_PMC); 5082 pmc_pcpu = NULL; 5083 5084 free(pmc_pcpu_saved, M_PMC); 5085 pmc_pcpu_saved = NULL; 5086 5087 if (pmc_pmcdisp) { 5088 free(pmc_pmcdisp, M_PMC); 5089 pmc_pmcdisp = NULL; 5090 } 5091 5092 if (pmc_rowindex_to_classdep) { 5093 free(pmc_rowindex_to_classdep, M_PMC); 5094 pmc_rowindex_to_classdep = NULL; 5095 } 5096 5097 pmclog_shutdown(); 5098 5099 sx_xunlock(&pmc_sx); /* we are done */ 5100 } 5101 5102 /* 5103 * The function called at load/unload. 5104 */ 5105 5106 static int 5107 load (struct module *module __unused, int cmd, void *arg __unused) 5108 { 5109 int error; 5110 5111 error = 0; 5112 5113 switch (cmd) { 5114 case MOD_LOAD : 5115 /* initialize the subsystem */ 5116 error = pmc_initialize(); 5117 if (error != 0) 5118 break; 5119 PMCDBG(MOD,INI,1, "syscall=%d maxcpu=%d", 5120 pmc_syscall_num, pmc_cpu_max()); 5121 break; 5122 5123 5124 case MOD_UNLOAD : 5125 case MOD_SHUTDOWN: 5126 pmc_cleanup(); 5127 PMCDBG(MOD,INI,1, "%s", "unloaded"); 5128 break; 5129 5130 default : 5131 error = EINVAL; /* XXX should panic(9) */ 5132 break; 5133 } 5134 5135 return error; 5136 } 5137 5138 /* memory pool */ 5139 MALLOC_DEFINE(M_PMC, "pmc", "Memory space for the PMC module"); 5140