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 int locked; 1636 vm_map_t map; 1637 struct vnode *vp; 1638 struct vmspace *vm; 1639 vm_map_entry_t entry; 1640 vm_offset_t last_end; 1641 u_int last_timestamp; 1642 struct vnode *last_vp; 1643 vm_offset_t start_addr; 1644 vm_object_t obj, lobj, tobj; 1645 char *fullpath, *freepath; 1646 1647 last_vp = NULL; 1648 last_end = (vm_offset_t) 0; 1649 fullpath = freepath = NULL; 1650 1651 if ((vm = vmspace_acquire_ref(p)) == NULL) 1652 return; 1653 1654 map = &vm->vm_map; 1655 vm_map_lock_read(map); 1656 1657 for (entry = map->header.next; entry != &map->header; entry = entry->next) { 1658 1659 if (entry == NULL) { 1660 PMCDBG(LOG,OPS,2, "hwpmc: vm_map entry unexpectedly " 1661 "NULL! pid=%d vm_map=%p\n", p->p_pid, map); 1662 break; 1663 } 1664 1665 /* 1666 * We only care about executable map entries. 1667 */ 1668 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) || 1669 !(entry->protection & VM_PROT_EXECUTE) || 1670 (entry->object.vm_object == NULL)) { 1671 continue; 1672 } 1673 1674 obj = entry->object.vm_object; 1675 VM_OBJECT_LOCK(obj); 1676 1677 /* 1678 * Walk the backing_object list to find the base 1679 * (non-shadowed) vm_object. 1680 */ 1681 for (lobj = tobj = obj; tobj != NULL; tobj = tobj->backing_object) { 1682 if (tobj != obj) 1683 VM_OBJECT_LOCK(tobj); 1684 if (lobj != obj) 1685 VM_OBJECT_UNLOCK(lobj); 1686 lobj = tobj; 1687 } 1688 1689 /* 1690 * At this point lobj is the base vm_object and it is locked. 1691 */ 1692 if (lobj == NULL) { 1693 PMCDBG(LOG,OPS,2, "hwpmc: lobj unexpectedly NULL! pid=%d " 1694 "vm_map=%p vm_obj=%p\n", p->p_pid, map, obj); 1695 VM_OBJECT_UNLOCK(obj); 1696 continue; 1697 } 1698 1699 if (lobj->type != OBJT_VNODE || lobj->handle == NULL) { 1700 if (lobj != obj) 1701 VM_OBJECT_UNLOCK(lobj); 1702 VM_OBJECT_UNLOCK(obj); 1703 continue; 1704 } 1705 1706 /* 1707 * Skip contiguous regions that point to the same 1708 * vnode, so we don't emit redundant MAP-IN 1709 * directives. 1710 */ 1711 if (entry->start == last_end && lobj->handle == last_vp) { 1712 last_end = entry->end; 1713 if (lobj != obj) 1714 VM_OBJECT_UNLOCK(lobj); 1715 VM_OBJECT_UNLOCK(obj); 1716 continue; 1717 } 1718 1719 /* 1720 * We don't want to keep the proc's vm_map or this 1721 * vm_object locked while we walk the pathname, since 1722 * vn_fullpath() can sleep. However, if we drop the 1723 * lock, it's possible for concurrent activity to 1724 * modify the vm_map list. To protect against this, 1725 * we save the vm_map timestamp before we release the 1726 * lock, and check it after we reacquire the lock 1727 * below. 1728 */ 1729 start_addr = entry->start; 1730 last_end = entry->end; 1731 last_timestamp = map->timestamp; 1732 vm_map_unlock_read(map); 1733 1734 vp = lobj->handle; 1735 vref(vp); 1736 if (lobj != obj) 1737 VM_OBJECT_UNLOCK(lobj); 1738 1739 VM_OBJECT_UNLOCK(obj); 1740 1741 freepath = NULL; 1742 pmc_getfilename(vp, &fullpath, &freepath); 1743 last_vp = vp; 1744 1745 locked = VFS_LOCK_GIANT(vp->v_mount); 1746 vrele(vp); 1747 VFS_UNLOCK_GIANT(locked); 1748 1749 vp = NULL; 1750 pmclog_process_map_in(po, p->p_pid, start_addr, fullpath); 1751 if (freepath) 1752 free(freepath, M_TEMP); 1753 1754 vm_map_lock_read(map); 1755 1756 /* 1757 * If our saved timestamp doesn't match, this means 1758 * that the vm_map was modified out from under us and 1759 * we can't trust our current "entry" pointer. Do a 1760 * new lookup for this entry. If there is no entry 1761 * for this address range, vm_map_lookup_entry() will 1762 * return the previous one, so we always want to go to 1763 * entry->next on the next loop iteration. 1764 * 1765 * There is an edge condition here that can occur if 1766 * there is no entry at or before this address. In 1767 * this situation, vm_map_lookup_entry returns 1768 * &map->header, which would cause our loop to abort 1769 * without processing the rest of the map. However, 1770 * in practice this will never happen for process 1771 * vm_map. This is because the executable's text 1772 * segment is the first mapping in the proc's address 1773 * space, and this mapping is never removed until the 1774 * process exits, so there will always be a non-header 1775 * entry at or before the requested address for 1776 * vm_map_lookup_entry to return. 1777 */ 1778 if (map->timestamp != last_timestamp) 1779 vm_map_lookup_entry(map, last_end - 1, &entry); 1780 } 1781 1782 vm_map_unlock_read(map); 1783 vmspace_free(vm); 1784 return; 1785 } 1786 1787 /* 1788 * Log mappings for all processes in the system. 1789 */ 1790 1791 static void 1792 pmc_log_all_process_mappings(struct pmc_owner *po) 1793 { 1794 struct proc *p, *top; 1795 1796 sx_assert(&pmc_sx, SX_XLOCKED); 1797 1798 if ((p = pfind(1)) == NULL) 1799 panic("[pmc,%d] Cannot find init", __LINE__); 1800 1801 PROC_UNLOCK(p); 1802 1803 sx_slock(&proctree_lock); 1804 1805 top = p; 1806 1807 for (;;) { 1808 pmc_log_process_mappings(po, p); 1809 if (!LIST_EMPTY(&p->p_children)) 1810 p = LIST_FIRST(&p->p_children); 1811 else for (;;) { 1812 if (p == top) 1813 goto done; 1814 if (LIST_NEXT(p, p_sibling)) { 1815 p = LIST_NEXT(p, p_sibling); 1816 break; 1817 } 1818 p = p->p_pptr; 1819 } 1820 } 1821 done: 1822 sx_sunlock(&proctree_lock); 1823 } 1824 1825 /* 1826 * The 'hook' invoked from the kernel proper 1827 */ 1828 1829 1830 #ifdef DEBUG 1831 const char *pmc_hooknames[] = { 1832 /* these strings correspond to PMC_FN_* in <sys/pmckern.h> */ 1833 "", 1834 "EXEC", 1835 "CSW-IN", 1836 "CSW-OUT", 1837 "SAMPLE", 1838 "KLDLOAD", 1839 "KLDUNLOAD", 1840 "MMAP", 1841 "MUNMAP", 1842 "CALLCHAIN-NMI", 1843 "CALLCHAIN-SOFT", 1844 "SOFTSAMPLING" 1845 }; 1846 #endif 1847 1848 static int 1849 pmc_hook_handler(struct thread *td, int function, void *arg) 1850 { 1851 1852 PMCDBG(MOD,PMH,1, "hook td=%p func=%d \"%s\" arg=%p", td, function, 1853 pmc_hooknames[function], arg); 1854 1855 switch (function) 1856 { 1857 1858 /* 1859 * Process exec() 1860 */ 1861 1862 case PMC_FN_PROCESS_EXEC: 1863 { 1864 char *fullpath, *freepath; 1865 unsigned int ri; 1866 int is_using_hwpmcs; 1867 struct pmc *pm; 1868 struct proc *p; 1869 struct pmc_owner *po; 1870 struct pmc_process *pp; 1871 struct pmckern_procexec *pk; 1872 1873 sx_assert(&pmc_sx, SX_XLOCKED); 1874 1875 p = td->td_proc; 1876 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 1877 1878 pk = (struct pmckern_procexec *) arg; 1879 1880 /* Inform owners of SS mode PMCs of the exec event. */ 1881 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1882 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1883 pmclog_process_procexec(po, PMC_ID_INVALID, 1884 p->p_pid, pk->pm_entryaddr, fullpath); 1885 1886 PROC_LOCK(p); 1887 is_using_hwpmcs = p->p_flag & P_HWPMC; 1888 PROC_UNLOCK(p); 1889 1890 if (!is_using_hwpmcs) { 1891 if (freepath) 1892 free(freepath, M_TEMP); 1893 break; 1894 } 1895 1896 /* 1897 * PMCs are not inherited across an exec(): remove any 1898 * PMCs that this process is the owner of. 1899 */ 1900 1901 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 1902 pmc_remove_owner(po); 1903 pmc_destroy_owner_descriptor(po); 1904 } 1905 1906 /* 1907 * If the process being exec'ed is not the target of any 1908 * PMC, we are done. 1909 */ 1910 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) { 1911 if (freepath) 1912 free(freepath, M_TEMP); 1913 break; 1914 } 1915 1916 /* 1917 * Log the exec event to all monitoring owners. Skip 1918 * owners who have already recieved the event because 1919 * they had system sampling PMCs active. 1920 */ 1921 for (ri = 0; ri < md->pmd_npmc; ri++) 1922 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 1923 po = pm->pm_owner; 1924 if (po->po_sscount == 0 && 1925 po->po_flags & PMC_PO_OWNS_LOGFILE) 1926 pmclog_process_procexec(po, pm->pm_id, 1927 p->p_pid, pk->pm_entryaddr, 1928 fullpath); 1929 } 1930 1931 if (freepath) 1932 free(freepath, M_TEMP); 1933 1934 1935 PMCDBG(PRC,EXC,1, "exec proc=%p (%d, %s) cred-changed=%d", 1936 p, p->p_pid, p->p_comm, pk->pm_credentialschanged); 1937 1938 if (pk->pm_credentialschanged == 0) /* no change */ 1939 break; 1940 1941 /* 1942 * If the newly exec()'ed process has a different credential 1943 * than before, allow it to be the target of a PMC only if 1944 * the PMC's owner has sufficient priviledge. 1945 */ 1946 1947 for (ri = 0; ri < md->pmd_npmc; ri++) 1948 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) 1949 if (pmc_can_attach(pm, td->td_proc) != 0) 1950 pmc_detach_one_process(td->td_proc, 1951 pm, PMC_FLAG_NONE); 1952 1953 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= (int) md->pmd_npmc, 1954 ("[pmc,%d] Illegal ref count %d on pp %p", __LINE__, 1955 pp->pp_refcnt, pp)); 1956 1957 /* 1958 * If this process is no longer the target of any 1959 * PMCs, we can remove the process entry and free 1960 * up space. 1961 */ 1962 1963 if (pp->pp_refcnt == 0) { 1964 pmc_remove_process_descriptor(pp); 1965 free(pp, M_PMC); 1966 break; 1967 } 1968 1969 } 1970 break; 1971 1972 case PMC_FN_CSW_IN: 1973 pmc_process_csw_in(td); 1974 break; 1975 1976 case PMC_FN_CSW_OUT: 1977 pmc_process_csw_out(td); 1978 break; 1979 1980 /* 1981 * Process accumulated PC samples. 1982 * 1983 * This function is expected to be called by hardclock() for 1984 * each CPU that has accumulated PC samples. 1985 * 1986 * This function is to be executed on the CPU whose samples 1987 * are being processed. 1988 */ 1989 case PMC_FN_DO_SAMPLES: 1990 1991 /* 1992 * Clear the cpu specific bit in the CPU mask before 1993 * do the rest of the processing. If the NMI handler 1994 * gets invoked after the "atomic_clear_int()" call 1995 * below but before "pmc_process_samples()" gets 1996 * around to processing the interrupt, then we will 1997 * come back here at the next hardclock() tick (and 1998 * may find nothing to do if "pmc_process_samples()" 1999 * had already processed the interrupt). We don't 2000 * lose the interrupt sample. 2001 */ 2002 CPU_CLR_ATOMIC(PCPU_GET(cpuid), &pmc_cpumask); 2003 pmc_process_samples(PCPU_GET(cpuid), PMC_HR); 2004 pmc_process_samples(PCPU_GET(cpuid), PMC_SR); 2005 break; 2006 2007 2008 case PMC_FN_KLD_LOAD: 2009 sx_assert(&pmc_sx, SX_LOCKED); 2010 pmc_process_kld_load((struct pmckern_map_in *) arg); 2011 break; 2012 2013 case PMC_FN_KLD_UNLOAD: 2014 sx_assert(&pmc_sx, SX_LOCKED); 2015 pmc_process_kld_unload((struct pmckern_map_out *) arg); 2016 break; 2017 2018 case PMC_FN_MMAP: 2019 sx_assert(&pmc_sx, SX_LOCKED); 2020 pmc_process_mmap(td, (struct pmckern_map_in *) arg); 2021 break; 2022 2023 case PMC_FN_MUNMAP: 2024 sx_assert(&pmc_sx, SX_LOCKED); 2025 pmc_process_munmap(td, (struct pmckern_map_out *) arg); 2026 break; 2027 2028 case PMC_FN_USER_CALLCHAIN: 2029 /* 2030 * Record a call chain. 2031 */ 2032 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 2033 __LINE__)); 2034 2035 pmc_capture_user_callchain(PCPU_GET(cpuid), PMC_HR, 2036 (struct trapframe *) arg); 2037 td->td_pflags &= ~TDP_CALLCHAIN; 2038 break; 2039 2040 case PMC_FN_USER_CALLCHAIN_SOFT: 2041 /* 2042 * Record a call chain. 2043 */ 2044 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 2045 __LINE__)); 2046 pmc_capture_user_callchain(PCPU_GET(cpuid), PMC_SR, 2047 (struct trapframe *) arg); 2048 td->td_pflags &= ~TDP_CALLCHAIN; 2049 break; 2050 2051 case PMC_FN_SOFT_SAMPLING: 2052 /* 2053 * Call soft PMC sampling intr. 2054 */ 2055 pmc_soft_intr((struct pmckern_soft *) arg); 2056 break; 2057 2058 default: 2059 #ifdef DEBUG 2060 KASSERT(0, ("[pmc,%d] unknown hook %d\n", __LINE__, function)); 2061 #endif 2062 break; 2063 2064 } 2065 2066 return 0; 2067 } 2068 2069 /* 2070 * allocate a 'struct pmc_owner' descriptor in the owner hash table. 2071 */ 2072 2073 static struct pmc_owner * 2074 pmc_allocate_owner_descriptor(struct proc *p) 2075 { 2076 uint32_t hindex; 2077 struct pmc_owner *po; 2078 struct pmc_ownerhash *poh; 2079 2080 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 2081 poh = &pmc_ownerhash[hindex]; 2082 2083 /* allocate space for N pointers and one descriptor struct */ 2084 po = malloc(sizeof(struct pmc_owner), M_PMC, M_WAITOK|M_ZERO); 2085 po->po_sscount = po->po_error = po->po_flags = po->po_logprocmaps = 0; 2086 po->po_file = NULL; 2087 po->po_owner = p; 2088 po->po_kthread = NULL; 2089 LIST_INIT(&po->po_pmcs); 2090 LIST_INSERT_HEAD(poh, po, po_next); /* insert into hash table */ 2091 2092 TAILQ_INIT(&po->po_logbuffers); 2093 mtx_init(&po->po_mtx, "pmc-owner-mtx", "pmc-per-proc", MTX_SPIN); 2094 2095 PMCDBG(OWN,ALL,1, "allocate-owner proc=%p (%d, %s) pmc-owner=%p", 2096 p, p->p_pid, p->p_comm, po); 2097 2098 return po; 2099 } 2100 2101 static void 2102 pmc_destroy_owner_descriptor(struct pmc_owner *po) 2103 { 2104 2105 PMCDBG(OWN,REL,1, "destroy-owner po=%p proc=%p (%d, %s)", 2106 po, po->po_owner, po->po_owner->p_pid, po->po_owner->p_comm); 2107 2108 mtx_destroy(&po->po_mtx); 2109 free(po, M_PMC); 2110 } 2111 2112 /* 2113 * find the descriptor corresponding to process 'p', adding or removing it 2114 * as specified by 'mode'. 2115 */ 2116 2117 static struct pmc_process * 2118 pmc_find_process_descriptor(struct proc *p, uint32_t mode) 2119 { 2120 uint32_t hindex; 2121 struct pmc_process *pp, *ppnew; 2122 struct pmc_processhash *pph; 2123 2124 hindex = PMC_HASH_PTR(p, pmc_processhashmask); 2125 pph = &pmc_processhash[hindex]; 2126 2127 ppnew = NULL; 2128 2129 /* 2130 * Pre-allocate memory in the FIND_ALLOCATE case since we 2131 * cannot call malloc(9) once we hold a spin lock. 2132 */ 2133 if (mode & PMC_FLAG_ALLOCATE) 2134 ppnew = malloc(sizeof(struct pmc_process) + md->pmd_npmc * 2135 sizeof(struct pmc_targetstate), M_PMC, M_WAITOK|M_ZERO); 2136 2137 mtx_lock_spin(&pmc_processhash_mtx); 2138 LIST_FOREACH(pp, pph, pp_next) 2139 if (pp->pp_proc == p) 2140 break; 2141 2142 if ((mode & PMC_FLAG_REMOVE) && pp != NULL) 2143 LIST_REMOVE(pp, pp_next); 2144 2145 if ((mode & PMC_FLAG_ALLOCATE) && pp == NULL && 2146 ppnew != NULL) { 2147 ppnew->pp_proc = p; 2148 LIST_INSERT_HEAD(pph, ppnew, pp_next); 2149 pp = ppnew; 2150 ppnew = NULL; 2151 } 2152 mtx_unlock_spin(&pmc_processhash_mtx); 2153 2154 if (pp != NULL && ppnew != NULL) 2155 free(ppnew, M_PMC); 2156 2157 return pp; 2158 } 2159 2160 /* 2161 * remove a process descriptor from the process hash table. 2162 */ 2163 2164 static void 2165 pmc_remove_process_descriptor(struct pmc_process *pp) 2166 { 2167 KASSERT(pp->pp_refcnt == 0, 2168 ("[pmc,%d] Removing process descriptor %p with count %d", 2169 __LINE__, pp, pp->pp_refcnt)); 2170 2171 mtx_lock_spin(&pmc_processhash_mtx); 2172 LIST_REMOVE(pp, pp_next); 2173 mtx_unlock_spin(&pmc_processhash_mtx); 2174 } 2175 2176 2177 /* 2178 * find an owner descriptor corresponding to proc 'p' 2179 */ 2180 2181 static struct pmc_owner * 2182 pmc_find_owner_descriptor(struct proc *p) 2183 { 2184 uint32_t hindex; 2185 struct pmc_owner *po; 2186 struct pmc_ownerhash *poh; 2187 2188 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 2189 poh = &pmc_ownerhash[hindex]; 2190 2191 po = NULL; 2192 LIST_FOREACH(po, poh, po_next) 2193 if (po->po_owner == p) 2194 break; 2195 2196 PMCDBG(OWN,FND,1, "find-owner proc=%p (%d, %s) hindex=0x%x -> " 2197 "pmc-owner=%p", p, p->p_pid, p->p_comm, hindex, po); 2198 2199 return po; 2200 } 2201 2202 /* 2203 * pmc_allocate_pmc_descriptor 2204 * 2205 * Allocate a pmc descriptor and initialize its 2206 * fields. 2207 */ 2208 2209 static struct pmc * 2210 pmc_allocate_pmc_descriptor(void) 2211 { 2212 struct pmc *pmc; 2213 2214 pmc = malloc(sizeof(struct pmc), M_PMC, M_WAITOK|M_ZERO); 2215 2216 if (pmc != NULL) { 2217 pmc->pm_owner = NULL; 2218 LIST_INIT(&pmc->pm_targets); 2219 } 2220 2221 PMCDBG(PMC,ALL,1, "allocate-pmc -> pmc=%p", pmc); 2222 2223 return pmc; 2224 } 2225 2226 /* 2227 * Destroy a pmc descriptor. 2228 */ 2229 2230 static void 2231 pmc_destroy_pmc_descriptor(struct pmc *pm) 2232 { 2233 (void) pm; 2234 2235 #ifdef DEBUG 2236 KASSERT(pm->pm_state == PMC_STATE_DELETED || 2237 pm->pm_state == PMC_STATE_FREE, 2238 ("[pmc,%d] destroying non-deleted PMC", __LINE__)); 2239 KASSERT(LIST_EMPTY(&pm->pm_targets), 2240 ("[pmc,%d] destroying pmc with targets", __LINE__)); 2241 KASSERT(pm->pm_owner == NULL, 2242 ("[pmc,%d] destroying pmc attached to an owner", __LINE__)); 2243 KASSERT(pm->pm_runcount == 0, 2244 ("[pmc,%d] pmc has non-zero run count %d", __LINE__, 2245 pm->pm_runcount)); 2246 #endif 2247 } 2248 2249 static void 2250 pmc_wait_for_pmc_idle(struct pmc *pm) 2251 { 2252 #ifdef DEBUG 2253 volatile int maxloop; 2254 2255 maxloop = 100 * pmc_cpu_max(); 2256 #endif 2257 /* 2258 * Loop (with a forced context switch) till the PMC's runcount 2259 * comes down to zero. 2260 */ 2261 while (atomic_load_acq_32(&pm->pm_runcount) > 0) { 2262 #ifdef DEBUG 2263 maxloop--; 2264 KASSERT(maxloop > 0, 2265 ("[pmc,%d] (ri%d, rc%d) waiting too long for " 2266 "pmc to be free", __LINE__, 2267 PMC_TO_ROWINDEX(pm), pm->pm_runcount)); 2268 #endif 2269 pmc_force_context_switch(); 2270 } 2271 } 2272 2273 /* 2274 * This function does the following things: 2275 * 2276 * - detaches the PMC from hardware 2277 * - unlinks all target threads that were attached to it 2278 * - removes the PMC from its owner's list 2279 * - destroy's the PMC private mutex 2280 * 2281 * Once this function completes, the given pmc pointer can be safely 2282 * FREE'd by the caller. 2283 */ 2284 2285 static void 2286 pmc_release_pmc_descriptor(struct pmc *pm) 2287 { 2288 enum pmc_mode mode; 2289 struct pmc_hw *phw; 2290 u_int adjri, ri, cpu; 2291 struct pmc_owner *po; 2292 struct pmc_binding pb; 2293 struct pmc_process *pp; 2294 struct pmc_classdep *pcd; 2295 struct pmc_target *ptgt, *tmp; 2296 2297 sx_assert(&pmc_sx, SX_XLOCKED); 2298 2299 KASSERT(pm, ("[pmc,%d] null pmc", __LINE__)); 2300 2301 ri = PMC_TO_ROWINDEX(pm); 2302 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2303 mode = PMC_TO_MODE(pm); 2304 2305 PMCDBG(PMC,REL,1, "release-pmc pmc=%p ri=%d mode=%d", pm, ri, 2306 mode); 2307 2308 /* 2309 * First, we take the PMC off hardware. 2310 */ 2311 cpu = 0; 2312 if (PMC_IS_SYSTEM_MODE(mode)) { 2313 2314 /* 2315 * A system mode PMC runs on a specific CPU. Switch 2316 * to this CPU and turn hardware off. 2317 */ 2318 pmc_save_cpu_binding(&pb); 2319 2320 cpu = PMC_TO_CPU(pm); 2321 2322 pmc_select_cpu(cpu); 2323 2324 /* switch off non-stalled CPUs */ 2325 if (pm->pm_state == PMC_STATE_RUNNING && 2326 pm->pm_stalled == 0) { 2327 2328 phw = pmc_pcpu[cpu]->pc_hwpmcs[ri]; 2329 2330 KASSERT(phw->phw_pmc == pm, 2331 ("[pmc, %d] pmc ptr ri(%d) hw(%p) pm(%p)", 2332 __LINE__, ri, phw->phw_pmc, pm)); 2333 PMCDBG(PMC,REL,2, "stopping cpu=%d ri=%d", cpu, ri); 2334 2335 critical_enter(); 2336 pcd->pcd_stop_pmc(cpu, adjri); 2337 critical_exit(); 2338 } 2339 2340 PMCDBG(PMC,REL,2, "decfg cpu=%d ri=%d", cpu, ri); 2341 2342 critical_enter(); 2343 pcd->pcd_config_pmc(cpu, adjri, NULL); 2344 critical_exit(); 2345 2346 /* adjust the global and process count of SS mode PMCs */ 2347 if (mode == PMC_MODE_SS && pm->pm_state == PMC_STATE_RUNNING) { 2348 po = pm->pm_owner; 2349 po->po_sscount--; 2350 if (po->po_sscount == 0) { 2351 atomic_subtract_rel_int(&pmc_ss_count, 1); 2352 LIST_REMOVE(po, po_ssnext); 2353 } 2354 } 2355 2356 pm->pm_state = PMC_STATE_DELETED; 2357 2358 pmc_restore_cpu_binding(&pb); 2359 2360 /* 2361 * We could have references to this PMC structure in 2362 * the per-cpu sample queues. Wait for the queue to 2363 * drain. 2364 */ 2365 pmc_wait_for_pmc_idle(pm); 2366 2367 } else if (PMC_IS_VIRTUAL_MODE(mode)) { 2368 2369 /* 2370 * A virtual PMC could be running on multiple CPUs at 2371 * a given instant. 2372 * 2373 * By marking its state as DELETED, we ensure that 2374 * this PMC is never further scheduled on hardware. 2375 * 2376 * Then we wait till all CPUs are done with this PMC. 2377 */ 2378 pm->pm_state = PMC_STATE_DELETED; 2379 2380 2381 /* Wait for the PMCs runcount to come to zero. */ 2382 pmc_wait_for_pmc_idle(pm); 2383 2384 /* 2385 * At this point the PMC is off all CPUs and cannot be 2386 * freshly scheduled onto a CPU. It is now safe to 2387 * unlink all targets from this PMC. If a 2388 * process-record's refcount falls to zero, we remove 2389 * it from the hash table. The module-wide SX lock 2390 * protects us from races. 2391 */ 2392 LIST_FOREACH_SAFE(ptgt, &pm->pm_targets, pt_next, tmp) { 2393 pp = ptgt->pt_process; 2394 pmc_unlink_target_process(pm, pp); /* frees 'ptgt' */ 2395 2396 PMCDBG(PMC,REL,3, "pp->refcnt=%d", pp->pp_refcnt); 2397 2398 /* 2399 * If the target process record shows that no 2400 * PMCs are attached to it, reclaim its space. 2401 */ 2402 2403 if (pp->pp_refcnt == 0) { 2404 pmc_remove_process_descriptor(pp); 2405 free(pp, M_PMC); 2406 } 2407 } 2408 2409 cpu = curthread->td_oncpu; /* setup cpu for pmd_release() */ 2410 2411 } 2412 2413 /* 2414 * Release any MD resources 2415 */ 2416 (void) pcd->pcd_release_pmc(cpu, adjri, pm); 2417 2418 /* 2419 * Update row disposition 2420 */ 2421 2422 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) 2423 PMC_UNMARK_ROW_STANDALONE(ri); 2424 else 2425 PMC_UNMARK_ROW_THREAD(ri); 2426 2427 /* unlink from the owner's list */ 2428 if (pm->pm_owner) { 2429 LIST_REMOVE(pm, pm_next); 2430 pm->pm_owner = NULL; 2431 } 2432 2433 pmc_destroy_pmc_descriptor(pm); 2434 } 2435 2436 /* 2437 * Register an owner and a pmc. 2438 */ 2439 2440 static int 2441 pmc_register_owner(struct proc *p, struct pmc *pmc) 2442 { 2443 struct pmc_owner *po; 2444 2445 sx_assert(&pmc_sx, SX_XLOCKED); 2446 2447 if ((po = pmc_find_owner_descriptor(p)) == NULL) 2448 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) 2449 return ENOMEM; 2450 2451 KASSERT(pmc->pm_owner == NULL, 2452 ("[pmc,%d] attempting to own an initialized PMC", __LINE__)); 2453 pmc->pm_owner = po; 2454 2455 LIST_INSERT_HEAD(&po->po_pmcs, pmc, pm_next); 2456 2457 PROC_LOCK(p); 2458 p->p_flag |= P_HWPMC; 2459 PROC_UNLOCK(p); 2460 2461 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 2462 pmclog_process_pmcallocate(pmc); 2463 2464 PMCDBG(PMC,REG,1, "register-owner pmc-owner=%p pmc=%p", 2465 po, pmc); 2466 2467 return 0; 2468 } 2469 2470 /* 2471 * Return the current row disposition: 2472 * == 0 => FREE 2473 * > 0 => PROCESS MODE 2474 * < 0 => SYSTEM MODE 2475 */ 2476 2477 int 2478 pmc_getrowdisp(int ri) 2479 { 2480 return pmc_pmcdisp[ri]; 2481 } 2482 2483 /* 2484 * Check if a PMC at row index 'ri' can be allocated to the current 2485 * process. 2486 * 2487 * Allocation can fail if: 2488 * - the current process is already being profiled by a PMC at index 'ri', 2489 * attached to it via OP_PMCATTACH. 2490 * - the current process has already allocated a PMC at index 'ri' 2491 * via OP_ALLOCATE. 2492 */ 2493 2494 static int 2495 pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, int cpu) 2496 { 2497 enum pmc_mode mode; 2498 struct pmc *pm; 2499 struct pmc_owner *po; 2500 struct pmc_process *pp; 2501 2502 PMCDBG(PMC,ALR,1, "can-allocate-rowindex proc=%p (%d, %s) ri=%d " 2503 "cpu=%d", p, p->p_pid, p->p_comm, ri, cpu); 2504 2505 /* 2506 * We shouldn't have already allocated a process-mode PMC at 2507 * row index 'ri'. 2508 * 2509 * We shouldn't have allocated a system-wide PMC on the same 2510 * CPU and same RI. 2511 */ 2512 if ((po = pmc_find_owner_descriptor(p)) != NULL) 2513 LIST_FOREACH(pm, &po->po_pmcs, pm_next) { 2514 if (PMC_TO_ROWINDEX(pm) == ri) { 2515 mode = PMC_TO_MODE(pm); 2516 if (PMC_IS_VIRTUAL_MODE(mode)) 2517 return EEXIST; 2518 if (PMC_IS_SYSTEM_MODE(mode) && 2519 (int) PMC_TO_CPU(pm) == cpu) 2520 return EEXIST; 2521 } 2522 } 2523 2524 /* 2525 * We also shouldn't be the target of any PMC at this index 2526 * since otherwise a PMC_ATTACH to ourselves will fail. 2527 */ 2528 if ((pp = pmc_find_process_descriptor(p, 0)) != NULL) 2529 if (pp->pp_pmcs[ri].pp_pmc) 2530 return EEXIST; 2531 2532 PMCDBG(PMC,ALR,2, "can-allocate-rowindex proc=%p (%d, %s) ri=%d ok", 2533 p, p->p_pid, p->p_comm, ri); 2534 2535 return 0; 2536 } 2537 2538 /* 2539 * Check if a given PMC at row index 'ri' can be currently used in 2540 * mode 'mode'. 2541 */ 2542 2543 static int 2544 pmc_can_allocate_row(int ri, enum pmc_mode mode) 2545 { 2546 enum pmc_disp disp; 2547 2548 sx_assert(&pmc_sx, SX_XLOCKED); 2549 2550 PMCDBG(PMC,ALR,1, "can-allocate-row ri=%d mode=%d", ri, mode); 2551 2552 if (PMC_IS_SYSTEM_MODE(mode)) 2553 disp = PMC_DISP_STANDALONE; 2554 else 2555 disp = PMC_DISP_THREAD; 2556 2557 /* 2558 * check disposition for PMC row 'ri': 2559 * 2560 * Expected disposition Row-disposition Result 2561 * 2562 * STANDALONE STANDALONE or FREE proceed 2563 * STANDALONE THREAD fail 2564 * THREAD THREAD or FREE proceed 2565 * THREAD STANDALONE fail 2566 */ 2567 2568 if (!PMC_ROW_DISP_IS_FREE(ri) && 2569 !(disp == PMC_DISP_THREAD && PMC_ROW_DISP_IS_THREAD(ri)) && 2570 !(disp == PMC_DISP_STANDALONE && PMC_ROW_DISP_IS_STANDALONE(ri))) 2571 return EBUSY; 2572 2573 /* 2574 * All OK 2575 */ 2576 2577 PMCDBG(PMC,ALR,2, "can-allocate-row ri=%d mode=%d ok", ri, mode); 2578 2579 return 0; 2580 2581 } 2582 2583 /* 2584 * Find a PMC descriptor with user handle 'pmcid' for thread 'td'. 2585 */ 2586 2587 static struct pmc * 2588 pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, pmc_id_t pmcid) 2589 { 2590 struct pmc *pm; 2591 2592 KASSERT(PMC_ID_TO_ROWINDEX(pmcid) < md->pmd_npmc, 2593 ("[pmc,%d] Illegal pmc index %d (max %d)", __LINE__, 2594 PMC_ID_TO_ROWINDEX(pmcid), md->pmd_npmc)); 2595 2596 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 2597 if (pm->pm_id == pmcid) 2598 return pm; 2599 2600 return NULL; 2601 } 2602 2603 static int 2604 pmc_find_pmc(pmc_id_t pmcid, struct pmc **pmc) 2605 { 2606 2607 struct pmc *pm; 2608 struct pmc_owner *po; 2609 2610 PMCDBG(PMC,FND,1, "find-pmc id=%d", pmcid); 2611 2612 if ((po = pmc_find_owner_descriptor(curthread->td_proc)) == NULL) 2613 return ESRCH; 2614 2615 if ((pm = pmc_find_pmc_descriptor_in_process(po, pmcid)) == NULL) 2616 return EINVAL; 2617 2618 PMCDBG(PMC,FND,2, "find-pmc id=%d -> pmc=%p", pmcid, pm); 2619 2620 *pmc = pm; 2621 return 0; 2622 } 2623 2624 /* 2625 * Start a PMC. 2626 */ 2627 2628 static int 2629 pmc_start(struct pmc *pm) 2630 { 2631 enum pmc_mode mode; 2632 struct pmc_owner *po; 2633 struct pmc_binding pb; 2634 struct pmc_classdep *pcd; 2635 int adjri, error, cpu, ri; 2636 2637 KASSERT(pm != NULL, 2638 ("[pmc,%d] null pm", __LINE__)); 2639 2640 mode = PMC_TO_MODE(pm); 2641 ri = PMC_TO_ROWINDEX(pm); 2642 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2643 2644 error = 0; 2645 2646 PMCDBG(PMC,OPS,1, "start pmc=%p mode=%d ri=%d", pm, mode, ri); 2647 2648 po = pm->pm_owner; 2649 2650 /* 2651 * Disallow PMCSTART if a logfile is required but has not been 2652 * configured yet. 2653 */ 2654 if ((pm->pm_flags & PMC_F_NEEDS_LOGFILE) && 2655 (po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) 2656 return (EDOOFUS); /* programming error */ 2657 2658 /* 2659 * If this is a sampling mode PMC, log mapping information for 2660 * the kernel modules that are currently loaded. 2661 */ 2662 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 2663 pmc_log_kernel_mappings(pm); 2664 2665 if (PMC_IS_VIRTUAL_MODE(mode)) { 2666 2667 /* 2668 * If a PMCATTACH has never been done on this PMC, 2669 * attach it to its owner process. 2670 */ 2671 2672 if (LIST_EMPTY(&pm->pm_targets)) 2673 error = (pm->pm_flags & PMC_F_ATTACH_DONE) ? ESRCH : 2674 pmc_attach_process(po->po_owner, pm); 2675 2676 /* 2677 * If the PMC is attached to its owner, then force a context 2678 * switch to ensure that the MD state gets set correctly. 2679 */ 2680 2681 if (error == 0) { 2682 pm->pm_state = PMC_STATE_RUNNING; 2683 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) 2684 pmc_force_context_switch(); 2685 } 2686 2687 return (error); 2688 } 2689 2690 2691 /* 2692 * A system-wide PMC. 2693 * 2694 * Add the owner to the global list if this is a system-wide 2695 * sampling PMC. 2696 */ 2697 2698 if (mode == PMC_MODE_SS) { 2699 if (po->po_sscount == 0) { 2700 LIST_INSERT_HEAD(&pmc_ss_owners, po, po_ssnext); 2701 atomic_add_rel_int(&pmc_ss_count, 1); 2702 PMCDBG(PMC,OPS,1, "po=%p in global list", po); 2703 } 2704 po->po_sscount++; 2705 2706 /* 2707 * Log mapping information for all existing processes in the 2708 * system. Subsequent mappings are logged as they happen; 2709 * see pmc_process_mmap(). 2710 */ 2711 if (po->po_logprocmaps == 0) { 2712 pmc_log_all_process_mappings(po); 2713 po->po_logprocmaps = 1; 2714 } 2715 } 2716 2717 /* 2718 * Move to the CPU associated with this 2719 * PMC, and start the hardware. 2720 */ 2721 2722 pmc_save_cpu_binding(&pb); 2723 2724 cpu = PMC_TO_CPU(pm); 2725 2726 if (!pmc_cpu_is_active(cpu)) 2727 return (ENXIO); 2728 2729 pmc_select_cpu(cpu); 2730 2731 /* 2732 * global PMCs are configured at allocation time 2733 * so write out the initial value and start the PMC. 2734 */ 2735 2736 pm->pm_state = PMC_STATE_RUNNING; 2737 2738 critical_enter(); 2739 if ((error = pcd->pcd_write_pmc(cpu, adjri, 2740 PMC_IS_SAMPLING_MODE(mode) ? 2741 pm->pm_sc.pm_reloadcount : 2742 pm->pm_sc.pm_initial)) == 0) 2743 error = pcd->pcd_start_pmc(cpu, adjri); 2744 critical_exit(); 2745 2746 pmc_restore_cpu_binding(&pb); 2747 2748 return (error); 2749 } 2750 2751 /* 2752 * Stop a PMC. 2753 */ 2754 2755 static int 2756 pmc_stop(struct pmc *pm) 2757 { 2758 struct pmc_owner *po; 2759 struct pmc_binding pb; 2760 struct pmc_classdep *pcd; 2761 int adjri, cpu, error, ri; 2762 2763 KASSERT(pm != NULL, ("[pmc,%d] null pmc", __LINE__)); 2764 2765 PMCDBG(PMC,OPS,1, "stop pmc=%p mode=%d ri=%d", pm, 2766 PMC_TO_MODE(pm), PMC_TO_ROWINDEX(pm)); 2767 2768 pm->pm_state = PMC_STATE_STOPPED; 2769 2770 /* 2771 * If the PMC is a virtual mode one, changing the state to 2772 * non-RUNNING is enough to ensure that the PMC never gets 2773 * scheduled. 2774 * 2775 * If this PMC is current running on a CPU, then it will 2776 * handled correctly at the time its target process is context 2777 * switched out. 2778 */ 2779 2780 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 2781 return 0; 2782 2783 /* 2784 * A system-mode PMC. Move to the CPU associated with 2785 * this PMC, and stop the hardware. We update the 2786 * 'initial count' so that a subsequent PMCSTART will 2787 * resume counting from the current hardware count. 2788 */ 2789 2790 pmc_save_cpu_binding(&pb); 2791 2792 cpu = PMC_TO_CPU(pm); 2793 2794 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 2795 ("[pmc,%d] illegal cpu=%d", __LINE__, cpu)); 2796 2797 if (!pmc_cpu_is_active(cpu)) 2798 return ENXIO; 2799 2800 pmc_select_cpu(cpu); 2801 2802 ri = PMC_TO_ROWINDEX(pm); 2803 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2804 2805 critical_enter(); 2806 if ((error = pcd->pcd_stop_pmc(cpu, adjri)) == 0) 2807 error = pcd->pcd_read_pmc(cpu, adjri, &pm->pm_sc.pm_initial); 2808 critical_exit(); 2809 2810 pmc_restore_cpu_binding(&pb); 2811 2812 po = pm->pm_owner; 2813 2814 /* remove this owner from the global list of SS PMC owners */ 2815 if (PMC_TO_MODE(pm) == PMC_MODE_SS) { 2816 po->po_sscount--; 2817 if (po->po_sscount == 0) { 2818 atomic_subtract_rel_int(&pmc_ss_count, 1); 2819 LIST_REMOVE(po, po_ssnext); 2820 PMCDBG(PMC,OPS,2,"po=%p removed from global list", po); 2821 } 2822 } 2823 2824 return (error); 2825 } 2826 2827 2828 #ifdef DEBUG 2829 static const char *pmc_op_to_name[] = { 2830 #undef __PMC_OP 2831 #define __PMC_OP(N, D) #N , 2832 __PMC_OPS() 2833 NULL 2834 }; 2835 #endif 2836 2837 /* 2838 * The syscall interface 2839 */ 2840 2841 #define PMC_GET_SX_XLOCK(...) do { \ 2842 sx_xlock(&pmc_sx); \ 2843 if (pmc_hook == NULL) { \ 2844 sx_xunlock(&pmc_sx); \ 2845 return __VA_ARGS__; \ 2846 } \ 2847 } while (0) 2848 2849 #define PMC_DOWNGRADE_SX() do { \ 2850 sx_downgrade(&pmc_sx); \ 2851 is_sx_downgraded = 1; \ 2852 } while (0) 2853 2854 static int 2855 pmc_syscall_handler(struct thread *td, void *syscall_args) 2856 { 2857 int error, is_sx_downgraded, is_sx_locked, op; 2858 struct pmc_syscall_args *c; 2859 void *arg; 2860 2861 PMC_GET_SX_XLOCK(ENOSYS); 2862 2863 DROP_GIANT(); 2864 2865 is_sx_downgraded = 0; 2866 is_sx_locked = 1; 2867 2868 c = (struct pmc_syscall_args *) syscall_args; 2869 2870 op = c->pmop_code; 2871 arg = c->pmop_data; 2872 2873 PMCDBG(MOD,PMS,1, "syscall op=%d \"%s\" arg=%p", op, 2874 pmc_op_to_name[op], arg); 2875 2876 error = 0; 2877 atomic_add_int(&pmc_stats.pm_syscalls, 1); 2878 2879 switch(op) 2880 { 2881 2882 2883 /* 2884 * Configure a log file. 2885 * 2886 * XXX This OP will be reworked. 2887 */ 2888 2889 case PMC_OP_CONFIGURELOG: 2890 { 2891 struct proc *p; 2892 struct pmc *pm; 2893 struct pmc_owner *po; 2894 struct pmc_op_configurelog cl; 2895 2896 sx_assert(&pmc_sx, SX_XLOCKED); 2897 2898 if ((error = copyin(arg, &cl, sizeof(cl))) != 0) 2899 break; 2900 2901 /* mark this process as owning a log file */ 2902 p = td->td_proc; 2903 if ((po = pmc_find_owner_descriptor(p)) == NULL) 2904 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) { 2905 error = ENOMEM; 2906 break; 2907 } 2908 2909 /* 2910 * If a valid fd was passed in, try to configure that, 2911 * otherwise if 'fd' was less than zero and there was 2912 * a log file configured, flush its buffers and 2913 * de-configure it. 2914 */ 2915 if (cl.pm_logfd >= 0) { 2916 sx_xunlock(&pmc_sx); 2917 is_sx_locked = 0; 2918 error = pmclog_configure_log(md, po, cl.pm_logfd); 2919 } else if (po->po_flags & PMC_PO_OWNS_LOGFILE) { 2920 pmclog_process_closelog(po); 2921 error = pmclog_close(po); 2922 if (error == 0) { 2923 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 2924 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 2925 pm->pm_state == PMC_STATE_RUNNING) 2926 pmc_stop(pm); 2927 error = pmclog_deconfigure_log(po); 2928 } 2929 } else 2930 error = EINVAL; 2931 2932 if (error) 2933 break; 2934 } 2935 break; 2936 2937 /* 2938 * Flush a log file. 2939 */ 2940 2941 case PMC_OP_FLUSHLOG: 2942 { 2943 struct pmc_owner *po; 2944 2945 sx_assert(&pmc_sx, SX_XLOCKED); 2946 2947 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 2948 error = EINVAL; 2949 break; 2950 } 2951 2952 error = pmclog_flush(po); 2953 } 2954 break; 2955 2956 /* 2957 * Close a log file. 2958 */ 2959 2960 case PMC_OP_CLOSELOG: 2961 { 2962 struct pmc_owner *po; 2963 2964 sx_assert(&pmc_sx, SX_XLOCKED); 2965 2966 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 2967 error = EINVAL; 2968 break; 2969 } 2970 2971 error = pmclog_close(po); 2972 } 2973 break; 2974 2975 /* 2976 * Retrieve hardware configuration. 2977 */ 2978 2979 case PMC_OP_GETCPUINFO: /* CPU information */ 2980 { 2981 struct pmc_op_getcpuinfo gci; 2982 struct pmc_classinfo *pci; 2983 struct pmc_classdep *pcd; 2984 int cl; 2985 2986 gci.pm_cputype = md->pmd_cputype; 2987 gci.pm_ncpu = pmc_cpu_max(); 2988 gci.pm_npmc = md->pmd_npmc; 2989 gci.pm_nclass = md->pmd_nclass; 2990 pci = gci.pm_classes; 2991 pcd = md->pmd_classdep; 2992 for (cl = 0; cl < md->pmd_nclass; cl++, pci++, pcd++) { 2993 pci->pm_caps = pcd->pcd_caps; 2994 pci->pm_class = pcd->pcd_class; 2995 pci->pm_width = pcd->pcd_width; 2996 pci->pm_num = pcd->pcd_num; 2997 } 2998 error = copyout(&gci, arg, sizeof(gci)); 2999 } 3000 break; 3001 3002 /* 3003 * Retrieve soft events list. 3004 */ 3005 case PMC_OP_GETDYNEVENTINFO: 3006 { 3007 enum pmc_class cl; 3008 enum pmc_event ev; 3009 struct pmc_op_getdyneventinfo *gei; 3010 struct pmc_dyn_event_descr dev; 3011 struct pmc_soft *ps; 3012 uint32_t nevent; 3013 3014 sx_assert(&pmc_sx, SX_LOCKED); 3015 3016 gei = (struct pmc_op_getdyneventinfo *) arg; 3017 3018 if ((error = copyin(&gei->pm_class, &cl, sizeof(cl))) != 0) 3019 break; 3020 3021 /* Only SOFT class is dynamic. */ 3022 if (cl != PMC_CLASS_SOFT) { 3023 error = EINVAL; 3024 break; 3025 } 3026 3027 nevent = 0; 3028 for (ev = PMC_EV_SOFT_FIRST; ev <= PMC_EV_SOFT_LAST; ev++) { 3029 ps = pmc_soft_ev_acquire(ev); 3030 if (ps == NULL) 3031 continue; 3032 bcopy(&ps->ps_ev, &dev, sizeof(dev)); 3033 pmc_soft_ev_release(ps); 3034 3035 error = copyout(&dev, 3036 &gei->pm_events[nevent], 3037 sizeof(struct pmc_dyn_event_descr)); 3038 if (error != 0) 3039 break; 3040 nevent++; 3041 } 3042 if (error != 0) 3043 break; 3044 3045 error = copyout(&nevent, &gei->pm_nevent, 3046 sizeof(nevent)); 3047 } 3048 break; 3049 3050 /* 3051 * Get module statistics 3052 */ 3053 3054 case PMC_OP_GETDRIVERSTATS: 3055 { 3056 struct pmc_op_getdriverstats gms; 3057 3058 bcopy(&pmc_stats, &gms, sizeof(gms)); 3059 error = copyout(&gms, arg, sizeof(gms)); 3060 } 3061 break; 3062 3063 3064 /* 3065 * Retrieve module version number 3066 */ 3067 3068 case PMC_OP_GETMODULEVERSION: 3069 { 3070 uint32_t cv, modv; 3071 3072 /* retrieve the client's idea of the ABI version */ 3073 if ((error = copyin(arg, &cv, sizeof(uint32_t))) != 0) 3074 break; 3075 /* don't service clients newer than our driver */ 3076 modv = PMC_VERSION; 3077 if ((cv & 0xFFFF0000) > (modv & 0xFFFF0000)) { 3078 error = EPROGMISMATCH; 3079 break; 3080 } 3081 error = copyout(&modv, arg, sizeof(int)); 3082 } 3083 break; 3084 3085 3086 /* 3087 * Retrieve the state of all the PMCs on a given 3088 * CPU. 3089 */ 3090 3091 case PMC_OP_GETPMCINFO: 3092 { 3093 int ari; 3094 struct pmc *pm; 3095 size_t pmcinfo_size; 3096 uint32_t cpu, n, npmc; 3097 struct pmc_owner *po; 3098 struct pmc_binding pb; 3099 struct pmc_classdep *pcd; 3100 struct pmc_info *p, *pmcinfo; 3101 struct pmc_op_getpmcinfo *gpi; 3102 3103 PMC_DOWNGRADE_SX(); 3104 3105 gpi = (struct pmc_op_getpmcinfo *) arg; 3106 3107 if ((error = copyin(&gpi->pm_cpu, &cpu, sizeof(cpu))) != 0) 3108 break; 3109 3110 if (cpu >= pmc_cpu_max()) { 3111 error = EINVAL; 3112 break; 3113 } 3114 3115 if (!pmc_cpu_is_active(cpu)) { 3116 error = ENXIO; 3117 break; 3118 } 3119 3120 /* switch to CPU 'cpu' */ 3121 pmc_save_cpu_binding(&pb); 3122 pmc_select_cpu(cpu); 3123 3124 npmc = md->pmd_npmc; 3125 3126 pmcinfo_size = npmc * sizeof(struct pmc_info); 3127 pmcinfo = malloc(pmcinfo_size, M_PMC, M_WAITOK); 3128 3129 p = pmcinfo; 3130 3131 for (n = 0; n < md->pmd_npmc; n++, p++) { 3132 3133 pcd = pmc_ri_to_classdep(md, n, &ari); 3134 3135 KASSERT(pcd != NULL, 3136 ("[pmc,%d] null pcd ri=%d", __LINE__, n)); 3137 3138 if ((error = pcd->pcd_describe(cpu, ari, p, &pm)) != 0) 3139 break; 3140 3141 if (PMC_ROW_DISP_IS_STANDALONE(n)) 3142 p->pm_rowdisp = PMC_DISP_STANDALONE; 3143 else if (PMC_ROW_DISP_IS_THREAD(n)) 3144 p->pm_rowdisp = PMC_DISP_THREAD; 3145 else 3146 p->pm_rowdisp = PMC_DISP_FREE; 3147 3148 p->pm_ownerpid = -1; 3149 3150 if (pm == NULL) /* no PMC associated */ 3151 continue; 3152 3153 po = pm->pm_owner; 3154 3155 KASSERT(po->po_owner != NULL, 3156 ("[pmc,%d] pmc_owner had a null proc pointer", 3157 __LINE__)); 3158 3159 p->pm_ownerpid = po->po_owner->p_pid; 3160 p->pm_mode = PMC_TO_MODE(pm); 3161 p->pm_event = pm->pm_event; 3162 p->pm_flags = pm->pm_flags; 3163 3164 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 3165 p->pm_reloadcount = 3166 pm->pm_sc.pm_reloadcount; 3167 } 3168 3169 pmc_restore_cpu_binding(&pb); 3170 3171 /* now copy out the PMC info collected */ 3172 if (error == 0) 3173 error = copyout(pmcinfo, &gpi->pm_pmcs, pmcinfo_size); 3174 3175 free(pmcinfo, M_PMC); 3176 } 3177 break; 3178 3179 3180 /* 3181 * Set the administrative state of a PMC. I.e. whether 3182 * the PMC is to be used or not. 3183 */ 3184 3185 case PMC_OP_PMCADMIN: 3186 { 3187 int cpu, ri; 3188 enum pmc_state request; 3189 struct pmc_cpu *pc; 3190 struct pmc_hw *phw; 3191 struct pmc_op_pmcadmin pma; 3192 struct pmc_binding pb; 3193 3194 sx_assert(&pmc_sx, SX_XLOCKED); 3195 3196 KASSERT(td == curthread, 3197 ("[pmc,%d] td != curthread", __LINE__)); 3198 3199 error = priv_check(td, PRIV_PMC_MANAGE); 3200 if (error) 3201 break; 3202 3203 if ((error = copyin(arg, &pma, sizeof(pma))) != 0) 3204 break; 3205 3206 cpu = pma.pm_cpu; 3207 3208 if (cpu < 0 || cpu >= (int) pmc_cpu_max()) { 3209 error = EINVAL; 3210 break; 3211 } 3212 3213 if (!pmc_cpu_is_active(cpu)) { 3214 error = ENXIO; 3215 break; 3216 } 3217 3218 request = pma.pm_state; 3219 3220 if (request != PMC_STATE_DISABLED && 3221 request != PMC_STATE_FREE) { 3222 error = EINVAL; 3223 break; 3224 } 3225 3226 ri = pma.pm_pmc; /* pmc id == row index */ 3227 if (ri < 0 || ri >= (int) md->pmd_npmc) { 3228 error = EINVAL; 3229 break; 3230 } 3231 3232 /* 3233 * We can't disable a PMC with a row-index allocated 3234 * for process virtual PMCs. 3235 */ 3236 3237 if (PMC_ROW_DISP_IS_THREAD(ri) && 3238 request == PMC_STATE_DISABLED) { 3239 error = EBUSY; 3240 break; 3241 } 3242 3243 /* 3244 * otherwise, this PMC on this CPU is either free or 3245 * in system-wide mode. 3246 */ 3247 3248 pmc_save_cpu_binding(&pb); 3249 pmc_select_cpu(cpu); 3250 3251 pc = pmc_pcpu[cpu]; 3252 phw = pc->pc_hwpmcs[ri]; 3253 3254 /* 3255 * XXX do we need some kind of 'forced' disable? 3256 */ 3257 3258 if (phw->phw_pmc == NULL) { 3259 if (request == PMC_STATE_DISABLED && 3260 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED)) { 3261 phw->phw_state &= ~PMC_PHW_FLAG_IS_ENABLED; 3262 PMC_MARK_ROW_STANDALONE(ri); 3263 } else if (request == PMC_STATE_FREE && 3264 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0) { 3265 phw->phw_state |= PMC_PHW_FLAG_IS_ENABLED; 3266 PMC_UNMARK_ROW_STANDALONE(ri); 3267 } 3268 /* other cases are a no-op */ 3269 } else 3270 error = EBUSY; 3271 3272 pmc_restore_cpu_binding(&pb); 3273 } 3274 break; 3275 3276 3277 /* 3278 * Allocate a PMC. 3279 */ 3280 3281 case PMC_OP_PMCALLOCATE: 3282 { 3283 int adjri, n; 3284 u_int cpu; 3285 uint32_t caps; 3286 struct pmc *pmc; 3287 enum pmc_mode mode; 3288 struct pmc_hw *phw; 3289 struct pmc_binding pb; 3290 struct pmc_classdep *pcd; 3291 struct pmc_op_pmcallocate pa; 3292 3293 if ((error = copyin(arg, &pa, sizeof(pa))) != 0) 3294 break; 3295 3296 caps = pa.pm_caps; 3297 mode = pa.pm_mode; 3298 cpu = pa.pm_cpu; 3299 3300 if ((mode != PMC_MODE_SS && mode != PMC_MODE_SC && 3301 mode != PMC_MODE_TS && mode != PMC_MODE_TC) || 3302 (cpu != (u_int) PMC_CPU_ANY && cpu >= pmc_cpu_max())) { 3303 error = EINVAL; 3304 break; 3305 } 3306 3307 /* 3308 * Virtual PMCs should only ask for a default CPU. 3309 * System mode PMCs need to specify a non-default CPU. 3310 */ 3311 3312 if ((PMC_IS_VIRTUAL_MODE(mode) && cpu != (u_int) PMC_CPU_ANY) || 3313 (PMC_IS_SYSTEM_MODE(mode) && cpu == (u_int) PMC_CPU_ANY)) { 3314 error = EINVAL; 3315 break; 3316 } 3317 3318 /* 3319 * Check that an inactive CPU is not being asked for. 3320 */ 3321 3322 if (PMC_IS_SYSTEM_MODE(mode) && !pmc_cpu_is_active(cpu)) { 3323 error = ENXIO; 3324 break; 3325 } 3326 3327 /* 3328 * Refuse an allocation for a system-wide PMC if this 3329 * process has been jailed, or if this process lacks 3330 * super-user credentials and the sysctl tunable 3331 * 'security.bsd.unprivileged_syspmcs' is zero. 3332 */ 3333 3334 if (PMC_IS_SYSTEM_MODE(mode)) { 3335 if (jailed(curthread->td_ucred)) { 3336 error = EPERM; 3337 break; 3338 } 3339 if (!pmc_unprivileged_syspmcs) { 3340 error = priv_check(curthread, 3341 PRIV_PMC_SYSTEM); 3342 if (error) 3343 break; 3344 } 3345 } 3346 3347 /* 3348 * Look for valid values for 'pm_flags' 3349 */ 3350 3351 if ((pa.pm_flags & ~(PMC_F_DESCENDANTS | PMC_F_LOG_PROCCSW | 3352 PMC_F_LOG_PROCEXIT | PMC_F_CALLCHAIN)) != 0) { 3353 error = EINVAL; 3354 break; 3355 } 3356 3357 /* process logging options are not allowed for system PMCs */ 3358 if (PMC_IS_SYSTEM_MODE(mode) && (pa.pm_flags & 3359 (PMC_F_LOG_PROCCSW | PMC_F_LOG_PROCEXIT))) { 3360 error = EINVAL; 3361 break; 3362 } 3363 3364 /* 3365 * All sampling mode PMCs need to be able to interrupt the 3366 * CPU. 3367 */ 3368 if (PMC_IS_SAMPLING_MODE(mode)) 3369 caps |= PMC_CAP_INTERRUPT; 3370 3371 /* A valid class specifier should have been passed in. */ 3372 for (n = 0; n < md->pmd_nclass; n++) 3373 if (md->pmd_classdep[n].pcd_class == pa.pm_class) 3374 break; 3375 if (n == md->pmd_nclass) { 3376 error = EINVAL; 3377 break; 3378 } 3379 3380 /* The requested PMC capabilities should be feasible. */ 3381 if ((md->pmd_classdep[n].pcd_caps & caps) != caps) { 3382 error = EOPNOTSUPP; 3383 break; 3384 } 3385 3386 PMCDBG(PMC,ALL,2, "event=%d caps=0x%x mode=%d cpu=%d", 3387 pa.pm_ev, caps, mode, cpu); 3388 3389 pmc = pmc_allocate_pmc_descriptor(); 3390 pmc->pm_id = PMC_ID_MAKE_ID(cpu,pa.pm_mode,pa.pm_class, 3391 PMC_ID_INVALID); 3392 pmc->pm_event = pa.pm_ev; 3393 pmc->pm_state = PMC_STATE_FREE; 3394 pmc->pm_caps = caps; 3395 pmc->pm_flags = pa.pm_flags; 3396 3397 /* switch thread to CPU 'cpu' */ 3398 pmc_save_cpu_binding(&pb); 3399 3400 #define PMC_IS_SHAREABLE_PMC(cpu, n) \ 3401 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_state & \ 3402 PMC_PHW_FLAG_IS_SHAREABLE) 3403 #define PMC_IS_UNALLOCATED(cpu, n) \ 3404 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_pmc == NULL) 3405 3406 if (PMC_IS_SYSTEM_MODE(mode)) { 3407 pmc_select_cpu(cpu); 3408 for (n = 0; n < (int) md->pmd_npmc; n++) { 3409 pcd = pmc_ri_to_classdep(md, n, &adjri); 3410 if (pmc_can_allocate_row(n, mode) == 0 && 3411 pmc_can_allocate_rowindex( 3412 curthread->td_proc, n, cpu) == 0 && 3413 (PMC_IS_UNALLOCATED(cpu, n) || 3414 PMC_IS_SHAREABLE_PMC(cpu, n)) && 3415 pcd->pcd_allocate_pmc(cpu, adjri, pmc, 3416 &pa) == 0) 3417 break; 3418 } 3419 } else { 3420 /* Process virtual mode */ 3421 for (n = 0; n < (int) md->pmd_npmc; n++) { 3422 pcd = pmc_ri_to_classdep(md, n, &adjri); 3423 if (pmc_can_allocate_row(n, mode) == 0 && 3424 pmc_can_allocate_rowindex( 3425 curthread->td_proc, n, 3426 PMC_CPU_ANY) == 0 && 3427 pcd->pcd_allocate_pmc(curthread->td_oncpu, 3428 adjri, pmc, &pa) == 0) 3429 break; 3430 } 3431 } 3432 3433 #undef PMC_IS_UNALLOCATED 3434 #undef PMC_IS_SHAREABLE_PMC 3435 3436 pmc_restore_cpu_binding(&pb); 3437 3438 if (n == (int) md->pmd_npmc) { 3439 pmc_destroy_pmc_descriptor(pmc); 3440 free(pmc, M_PMC); 3441 pmc = NULL; 3442 error = EINVAL; 3443 break; 3444 } 3445 3446 /* Fill in the correct value in the ID field */ 3447 pmc->pm_id = PMC_ID_MAKE_ID(cpu,mode,pa.pm_class,n); 3448 3449 PMCDBG(PMC,ALL,2, "ev=%d class=%d mode=%d n=%d -> pmcid=%x", 3450 pmc->pm_event, pa.pm_class, mode, n, pmc->pm_id); 3451 3452 /* Process mode PMCs with logging enabled need log files */ 3453 if (pmc->pm_flags & (PMC_F_LOG_PROCEXIT | PMC_F_LOG_PROCCSW)) 3454 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3455 3456 /* All system mode sampling PMCs require a log file */ 3457 if (PMC_IS_SAMPLING_MODE(mode) && PMC_IS_SYSTEM_MODE(mode)) 3458 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3459 3460 /* 3461 * Configure global pmc's immediately 3462 */ 3463 3464 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pmc))) { 3465 3466 pmc_save_cpu_binding(&pb); 3467 pmc_select_cpu(cpu); 3468 3469 phw = pmc_pcpu[cpu]->pc_hwpmcs[n]; 3470 pcd = pmc_ri_to_classdep(md, n, &adjri); 3471 3472 if ((phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0 || 3473 (error = pcd->pcd_config_pmc(cpu, adjri, pmc)) != 0) { 3474 (void) pcd->pcd_release_pmc(cpu, adjri, pmc); 3475 pmc_destroy_pmc_descriptor(pmc); 3476 free(pmc, M_PMC); 3477 pmc = NULL; 3478 pmc_restore_cpu_binding(&pb); 3479 error = EPERM; 3480 break; 3481 } 3482 3483 pmc_restore_cpu_binding(&pb); 3484 } 3485 3486 pmc->pm_state = PMC_STATE_ALLOCATED; 3487 3488 /* 3489 * mark row disposition 3490 */ 3491 3492 if (PMC_IS_SYSTEM_MODE(mode)) 3493 PMC_MARK_ROW_STANDALONE(n); 3494 else 3495 PMC_MARK_ROW_THREAD(n); 3496 3497 /* 3498 * Register this PMC with the current thread as its owner. 3499 */ 3500 3501 if ((error = 3502 pmc_register_owner(curthread->td_proc, pmc)) != 0) { 3503 pmc_release_pmc_descriptor(pmc); 3504 free(pmc, M_PMC); 3505 pmc = NULL; 3506 break; 3507 } 3508 3509 /* 3510 * Return the allocated index. 3511 */ 3512 3513 pa.pm_pmcid = pmc->pm_id; 3514 3515 error = copyout(&pa, arg, sizeof(pa)); 3516 } 3517 break; 3518 3519 3520 /* 3521 * Attach a PMC to a process. 3522 */ 3523 3524 case PMC_OP_PMCATTACH: 3525 { 3526 struct pmc *pm; 3527 struct proc *p; 3528 struct pmc_op_pmcattach a; 3529 3530 sx_assert(&pmc_sx, SX_XLOCKED); 3531 3532 if ((error = copyin(arg, &a, sizeof(a))) != 0) 3533 break; 3534 3535 if (a.pm_pid < 0) { 3536 error = EINVAL; 3537 break; 3538 } else if (a.pm_pid == 0) 3539 a.pm_pid = td->td_proc->p_pid; 3540 3541 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 3542 break; 3543 3544 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) { 3545 error = EINVAL; 3546 break; 3547 } 3548 3549 /* PMCs may be (re)attached only when allocated or stopped */ 3550 if (pm->pm_state == PMC_STATE_RUNNING) { 3551 error = EBUSY; 3552 break; 3553 } else if (pm->pm_state != PMC_STATE_ALLOCATED && 3554 pm->pm_state != PMC_STATE_STOPPED) { 3555 error = EINVAL; 3556 break; 3557 } 3558 3559 /* lookup pid */ 3560 if ((p = pfind(a.pm_pid)) == NULL) { 3561 error = ESRCH; 3562 break; 3563 } 3564 3565 /* 3566 * Ignore processes that are working on exiting. 3567 */ 3568 if (p->p_flag & P_WEXIT) { 3569 error = ESRCH; 3570 PROC_UNLOCK(p); /* pfind() returns a locked process */ 3571 break; 3572 } 3573 3574 /* 3575 * we are allowed to attach a PMC to a process if 3576 * we can debug it. 3577 */ 3578 error = p_candebug(curthread, p); 3579 3580 PROC_UNLOCK(p); 3581 3582 if (error == 0) 3583 error = pmc_attach_process(p, pm); 3584 } 3585 break; 3586 3587 3588 /* 3589 * Detach an attached PMC from a process. 3590 */ 3591 3592 case PMC_OP_PMCDETACH: 3593 { 3594 struct pmc *pm; 3595 struct proc *p; 3596 struct pmc_op_pmcattach a; 3597 3598 if ((error = copyin(arg, &a, sizeof(a))) != 0) 3599 break; 3600 3601 if (a.pm_pid < 0) { 3602 error = EINVAL; 3603 break; 3604 } else if (a.pm_pid == 0) 3605 a.pm_pid = td->td_proc->p_pid; 3606 3607 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 3608 break; 3609 3610 if ((p = pfind(a.pm_pid)) == NULL) { 3611 error = ESRCH; 3612 break; 3613 } 3614 3615 /* 3616 * Treat processes that are in the process of exiting 3617 * as if they were not present. 3618 */ 3619 3620 if (p->p_flag & P_WEXIT) 3621 error = ESRCH; 3622 3623 PROC_UNLOCK(p); /* pfind() returns a locked process */ 3624 3625 if (error == 0) 3626 error = pmc_detach_process(p, pm); 3627 } 3628 break; 3629 3630 3631 /* 3632 * Retrieve the MSR number associated with the counter 3633 * 'pmc_id'. This allows processes to directly use RDPMC 3634 * instructions to read their PMCs, without the overhead of a 3635 * system call. 3636 */ 3637 3638 case PMC_OP_PMCGETMSR: 3639 { 3640 int adjri, ri; 3641 struct pmc *pm; 3642 struct pmc_target *pt; 3643 struct pmc_op_getmsr gm; 3644 struct pmc_classdep *pcd; 3645 3646 PMC_DOWNGRADE_SX(); 3647 3648 if ((error = copyin(arg, &gm, sizeof(gm))) != 0) 3649 break; 3650 3651 if ((error = pmc_find_pmc(gm.pm_pmcid, &pm)) != 0) 3652 break; 3653 3654 /* 3655 * The allocated PMC has to be a process virtual PMC, 3656 * i.e., of type MODE_T[CS]. Global PMCs can only be 3657 * read using the PMCREAD operation since they may be 3658 * allocated on a different CPU than the one we could 3659 * be running on at the time of the RDPMC instruction. 3660 * 3661 * The GETMSR operation is not allowed for PMCs that 3662 * are inherited across processes. 3663 */ 3664 3665 if (!PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)) || 3666 (pm->pm_flags & PMC_F_DESCENDANTS)) { 3667 error = EINVAL; 3668 break; 3669 } 3670 3671 /* 3672 * It only makes sense to use a RDPMC (or its 3673 * equivalent instruction on non-x86 architectures) on 3674 * a process that has allocated and attached a PMC to 3675 * itself. Conversely the PMC is only allowed to have 3676 * one process attached to it -- its owner. 3677 */ 3678 3679 if ((pt = LIST_FIRST(&pm->pm_targets)) == NULL || 3680 LIST_NEXT(pt, pt_next) != NULL || 3681 pt->pt_process->pp_proc != pm->pm_owner->po_owner) { 3682 error = EINVAL; 3683 break; 3684 } 3685 3686 ri = PMC_TO_ROWINDEX(pm); 3687 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3688 3689 /* PMC class has no 'GETMSR' support */ 3690 if (pcd->pcd_get_msr == NULL) { 3691 error = ENOSYS; 3692 break; 3693 } 3694 3695 if ((error = (*pcd->pcd_get_msr)(adjri, &gm.pm_msr)) < 0) 3696 break; 3697 3698 if ((error = copyout(&gm, arg, sizeof(gm))) < 0) 3699 break; 3700 3701 /* 3702 * Mark our process as using MSRs. Update machine 3703 * state using a forced context switch. 3704 */ 3705 3706 pt->pt_process->pp_flags |= PMC_PP_ENABLE_MSR_ACCESS; 3707 pmc_force_context_switch(); 3708 3709 } 3710 break; 3711 3712 /* 3713 * Release an allocated PMC 3714 */ 3715 3716 case PMC_OP_PMCRELEASE: 3717 { 3718 pmc_id_t pmcid; 3719 struct pmc *pm; 3720 struct pmc_owner *po; 3721 struct pmc_op_simple sp; 3722 3723 /* 3724 * Find PMC pointer for the named PMC. 3725 * 3726 * Use pmc_release_pmc_descriptor() to switch off the 3727 * PMC, remove all its target threads, and remove the 3728 * PMC from its owner's list. 3729 * 3730 * Remove the owner record if this is the last PMC 3731 * owned. 3732 * 3733 * Free up space. 3734 */ 3735 3736 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3737 break; 3738 3739 pmcid = sp.pm_pmcid; 3740 3741 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3742 break; 3743 3744 po = pm->pm_owner; 3745 pmc_release_pmc_descriptor(pm); 3746 pmc_maybe_remove_owner(po); 3747 3748 free(pm, M_PMC); 3749 } 3750 break; 3751 3752 3753 /* 3754 * Read and/or write a PMC. 3755 */ 3756 3757 case PMC_OP_PMCRW: 3758 { 3759 int adjri; 3760 struct pmc *pm; 3761 uint32_t cpu, ri; 3762 pmc_value_t oldvalue; 3763 struct pmc_binding pb; 3764 struct pmc_op_pmcrw prw; 3765 struct pmc_classdep *pcd; 3766 struct pmc_op_pmcrw *pprw; 3767 3768 PMC_DOWNGRADE_SX(); 3769 3770 if ((error = copyin(arg, &prw, sizeof(prw))) != 0) 3771 break; 3772 3773 ri = 0; 3774 PMCDBG(PMC,OPS,1, "rw id=%d flags=0x%x", prw.pm_pmcid, 3775 prw.pm_flags); 3776 3777 /* must have at least one flag set */ 3778 if ((prw.pm_flags & (PMC_F_OLDVALUE|PMC_F_NEWVALUE)) == 0) { 3779 error = EINVAL; 3780 break; 3781 } 3782 3783 /* locate pmc descriptor */ 3784 if ((error = pmc_find_pmc(prw.pm_pmcid, &pm)) != 0) 3785 break; 3786 3787 /* Can't read a PMC that hasn't been started. */ 3788 if (pm->pm_state != PMC_STATE_ALLOCATED && 3789 pm->pm_state != PMC_STATE_STOPPED && 3790 pm->pm_state != PMC_STATE_RUNNING) { 3791 error = EINVAL; 3792 break; 3793 } 3794 3795 /* writing a new value is allowed only for 'STOPPED' pmcs */ 3796 if (pm->pm_state == PMC_STATE_RUNNING && 3797 (prw.pm_flags & PMC_F_NEWVALUE)) { 3798 error = EBUSY; 3799 break; 3800 } 3801 3802 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) { 3803 3804 /* 3805 * If this PMC is attached to its owner (i.e., 3806 * the process requesting this operation) and 3807 * is running, then attempt to get an 3808 * upto-date reading from hardware for a READ. 3809 * Writes are only allowed when the PMC is 3810 * stopped, so only update the saved value 3811 * field. 3812 * 3813 * If the PMC is not running, or is not 3814 * attached to its owner, read/write to the 3815 * savedvalue field. 3816 */ 3817 3818 ri = PMC_TO_ROWINDEX(pm); 3819 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3820 3821 mtx_pool_lock_spin(pmc_mtxpool, pm); 3822 cpu = curthread->td_oncpu; 3823 3824 if (prw.pm_flags & PMC_F_OLDVALUE) { 3825 if ((pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) && 3826 (pm->pm_state == PMC_STATE_RUNNING)) 3827 error = (*pcd->pcd_read_pmc)(cpu, adjri, 3828 &oldvalue); 3829 else 3830 oldvalue = pm->pm_gv.pm_savedvalue; 3831 } 3832 if (prw.pm_flags & PMC_F_NEWVALUE) 3833 pm->pm_gv.pm_savedvalue = prw.pm_value; 3834 3835 mtx_pool_unlock_spin(pmc_mtxpool, pm); 3836 3837 } else { /* System mode PMCs */ 3838 cpu = PMC_TO_CPU(pm); 3839 ri = PMC_TO_ROWINDEX(pm); 3840 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3841 3842 if (!pmc_cpu_is_active(cpu)) { 3843 error = ENXIO; 3844 break; 3845 } 3846 3847 /* move this thread to CPU 'cpu' */ 3848 pmc_save_cpu_binding(&pb); 3849 pmc_select_cpu(cpu); 3850 3851 critical_enter(); 3852 /* save old value */ 3853 if (prw.pm_flags & PMC_F_OLDVALUE) 3854 if ((error = (*pcd->pcd_read_pmc)(cpu, adjri, 3855 &oldvalue))) 3856 goto error; 3857 /* write out new value */ 3858 if (prw.pm_flags & PMC_F_NEWVALUE) 3859 error = (*pcd->pcd_write_pmc)(cpu, adjri, 3860 prw.pm_value); 3861 error: 3862 critical_exit(); 3863 pmc_restore_cpu_binding(&pb); 3864 if (error) 3865 break; 3866 } 3867 3868 pprw = (struct pmc_op_pmcrw *) arg; 3869 3870 #ifdef DEBUG 3871 if (prw.pm_flags & PMC_F_NEWVALUE) 3872 PMCDBG(PMC,OPS,2, "rw id=%d new %jx -> old %jx", 3873 ri, prw.pm_value, oldvalue); 3874 else if (prw.pm_flags & PMC_F_OLDVALUE) 3875 PMCDBG(PMC,OPS,2, "rw id=%d -> old %jx", ri, oldvalue); 3876 #endif 3877 3878 /* return old value if requested */ 3879 if (prw.pm_flags & PMC_F_OLDVALUE) 3880 if ((error = copyout(&oldvalue, &pprw->pm_value, 3881 sizeof(prw.pm_value)))) 3882 break; 3883 3884 } 3885 break; 3886 3887 3888 /* 3889 * Set the sampling rate for a sampling mode PMC and the 3890 * initial count for a counting mode PMC. 3891 */ 3892 3893 case PMC_OP_PMCSETCOUNT: 3894 { 3895 struct pmc *pm; 3896 struct pmc_op_pmcsetcount sc; 3897 3898 PMC_DOWNGRADE_SX(); 3899 3900 if ((error = copyin(arg, &sc, sizeof(sc))) != 0) 3901 break; 3902 3903 if ((error = pmc_find_pmc(sc.pm_pmcid, &pm)) != 0) 3904 break; 3905 3906 if (pm->pm_state == PMC_STATE_RUNNING) { 3907 error = EBUSY; 3908 break; 3909 } 3910 3911 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 3912 pm->pm_sc.pm_reloadcount = sc.pm_count; 3913 else 3914 pm->pm_sc.pm_initial = sc.pm_count; 3915 } 3916 break; 3917 3918 3919 /* 3920 * Start a PMC. 3921 */ 3922 3923 case PMC_OP_PMCSTART: 3924 { 3925 pmc_id_t pmcid; 3926 struct pmc *pm; 3927 struct pmc_op_simple sp; 3928 3929 sx_assert(&pmc_sx, SX_XLOCKED); 3930 3931 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3932 break; 3933 3934 pmcid = sp.pm_pmcid; 3935 3936 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3937 break; 3938 3939 KASSERT(pmcid == pm->pm_id, 3940 ("[pmc,%d] pmcid %x != id %x", __LINE__, 3941 pm->pm_id, pmcid)); 3942 3943 if (pm->pm_state == PMC_STATE_RUNNING) /* already running */ 3944 break; 3945 else if (pm->pm_state != PMC_STATE_STOPPED && 3946 pm->pm_state != PMC_STATE_ALLOCATED) { 3947 error = EINVAL; 3948 break; 3949 } 3950 3951 error = pmc_start(pm); 3952 } 3953 break; 3954 3955 3956 /* 3957 * Stop a PMC. 3958 */ 3959 3960 case PMC_OP_PMCSTOP: 3961 { 3962 pmc_id_t pmcid; 3963 struct pmc *pm; 3964 struct pmc_op_simple sp; 3965 3966 PMC_DOWNGRADE_SX(); 3967 3968 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3969 break; 3970 3971 pmcid = sp.pm_pmcid; 3972 3973 /* 3974 * Mark the PMC as inactive and invoke the MD stop 3975 * routines if needed. 3976 */ 3977 3978 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3979 break; 3980 3981 KASSERT(pmcid == pm->pm_id, 3982 ("[pmc,%d] pmc id %x != pmcid %x", __LINE__, 3983 pm->pm_id, pmcid)); 3984 3985 if (pm->pm_state == PMC_STATE_STOPPED) /* already stopped */ 3986 break; 3987 else if (pm->pm_state != PMC_STATE_RUNNING) { 3988 error = EINVAL; 3989 break; 3990 } 3991 3992 error = pmc_stop(pm); 3993 } 3994 break; 3995 3996 3997 /* 3998 * Write a user supplied value to the log file. 3999 */ 4000 4001 case PMC_OP_WRITELOG: 4002 { 4003 struct pmc_op_writelog wl; 4004 struct pmc_owner *po; 4005 4006 PMC_DOWNGRADE_SX(); 4007 4008 if ((error = copyin(arg, &wl, sizeof(wl))) != 0) 4009 break; 4010 4011 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 4012 error = EINVAL; 4013 break; 4014 } 4015 4016 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) { 4017 error = EINVAL; 4018 break; 4019 } 4020 4021 error = pmclog_process_userlog(po, &wl); 4022 } 4023 break; 4024 4025 4026 default: 4027 error = EINVAL; 4028 break; 4029 } 4030 4031 if (is_sx_locked != 0) { 4032 if (is_sx_downgraded) 4033 sx_sunlock(&pmc_sx); 4034 else 4035 sx_xunlock(&pmc_sx); 4036 } 4037 4038 if (error) 4039 atomic_add_int(&pmc_stats.pm_syscall_errors, 1); 4040 4041 PICKUP_GIANT(); 4042 4043 return error; 4044 } 4045 4046 /* 4047 * Helper functions 4048 */ 4049 4050 4051 /* 4052 * Mark the thread as needing callchain capture and post an AST. The 4053 * actual callchain capture will be done in a context where it is safe 4054 * to take page faults. 4055 */ 4056 4057 static void 4058 pmc_post_callchain_callback(void) 4059 { 4060 struct thread *td; 4061 4062 td = curthread; 4063 4064 /* 4065 * If there is multiple PMCs for the same interrupt ignore new post 4066 */ 4067 if (td->td_pflags & TDP_CALLCHAIN) 4068 return; 4069 4070 /* 4071 * Mark this thread as needing callchain capture. 4072 * `td->td_pflags' will be safe to touch because this thread 4073 * was in user space when it was interrupted. 4074 */ 4075 td->td_pflags |= TDP_CALLCHAIN; 4076 4077 /* 4078 * Don't let this thread migrate between CPUs until callchain 4079 * capture completes. 4080 */ 4081 sched_pin(); 4082 4083 return; 4084 } 4085 4086 /* 4087 * Interrupt processing. 4088 * 4089 * Find a free slot in the per-cpu array of samples and capture the 4090 * current callchain there. If a sample was successfully added, a bit 4091 * is set in mask 'pmc_cpumask' denoting that the DO_SAMPLES hook 4092 * needs to be invoked from the clock handler. 4093 * 4094 * This function is meant to be called from an NMI handler. It cannot 4095 * use any of the locking primitives supplied by the OS. 4096 */ 4097 4098 int 4099 pmc_process_interrupt(int cpu, int ring, struct pmc *pm, struct trapframe *tf, 4100 int inuserspace) 4101 { 4102 int error, callchaindepth; 4103 struct thread *td; 4104 struct pmc_sample *ps; 4105 struct pmc_samplebuffer *psb; 4106 4107 error = 0; 4108 4109 /* 4110 * Allocate space for a sample buffer. 4111 */ 4112 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4113 4114 ps = psb->ps_write; 4115 if (ps->ps_nsamples) { /* in use, reader hasn't caught up */ 4116 pm->pm_stalled = 1; 4117 atomic_add_int(&pmc_stats.pm_intr_bufferfull, 1); 4118 PMCDBG(SAM,INT,1,"(spc) cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", 4119 cpu, pm, (void *) tf, inuserspace, 4120 (int) (psb->ps_write - psb->ps_samples), 4121 (int) (psb->ps_read - psb->ps_samples)); 4122 error = ENOMEM; 4123 goto done; 4124 } 4125 4126 4127 /* Fill in entry. */ 4128 PMCDBG(SAM,INT,1,"cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", cpu, pm, 4129 (void *) tf, inuserspace, 4130 (int) (psb->ps_write - psb->ps_samples), 4131 (int) (psb->ps_read - psb->ps_samples)); 4132 4133 KASSERT(pm->pm_runcount >= 0, 4134 ("[pmc,%d] pm=%p runcount %d", __LINE__, (void *) pm, 4135 pm->pm_runcount)); 4136 4137 atomic_add_rel_int(&pm->pm_runcount, 1); /* hold onto PMC */ 4138 4139 ps->ps_pmc = pm; 4140 if ((td = curthread) && td->td_proc) 4141 ps->ps_pid = td->td_proc->p_pid; 4142 else 4143 ps->ps_pid = -1; 4144 ps->ps_cpu = cpu; 4145 ps->ps_td = td; 4146 ps->ps_flags = inuserspace ? PMC_CC_F_USERSPACE : 0; 4147 4148 callchaindepth = (pm->pm_flags & PMC_F_CALLCHAIN) ? 4149 pmc_callchaindepth : 1; 4150 4151 if (callchaindepth == 1) 4152 ps->ps_pc[0] = PMC_TRAPFRAME_TO_PC(tf); 4153 else { 4154 /* 4155 * Kernel stack traversals can be done immediately, 4156 * while we defer to an AST for user space traversals. 4157 */ 4158 if (!inuserspace) { 4159 callchaindepth = 4160 pmc_save_kernel_callchain(ps->ps_pc, 4161 callchaindepth, tf); 4162 } else { 4163 pmc_post_callchain_callback(); 4164 callchaindepth = PMC_SAMPLE_INUSE; 4165 } 4166 } 4167 4168 ps->ps_nsamples = callchaindepth; /* mark entry as in use */ 4169 4170 /* increment write pointer, modulo ring buffer size */ 4171 ps++; 4172 if (ps == psb->ps_fence) 4173 psb->ps_write = psb->ps_samples; 4174 else 4175 psb->ps_write = ps; 4176 4177 done: 4178 /* mark CPU as needing processing */ 4179 CPU_SET_ATOMIC(cpu, &pmc_cpumask); 4180 4181 return (error); 4182 } 4183 4184 /* 4185 * Capture a user call chain. This function will be called from ast() 4186 * before control returns to userland and before the process gets 4187 * rescheduled. 4188 */ 4189 4190 static void 4191 pmc_capture_user_callchain(int cpu, int ring, struct trapframe *tf) 4192 { 4193 int i; 4194 struct pmc *pm; 4195 struct thread *td; 4196 struct pmc_sample *ps; 4197 struct pmc_samplebuffer *psb; 4198 #ifdef INVARIANTS 4199 int ncallchains; 4200 #endif 4201 4202 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4203 td = curthread; 4204 4205 KASSERT(td->td_pflags & TDP_CALLCHAIN, 4206 ("[pmc,%d] Retrieving callchain for thread that doesn't want it", 4207 __LINE__)); 4208 4209 #ifdef INVARIANTS 4210 ncallchains = 0; 4211 #endif 4212 4213 /* 4214 * Iterate through all deferred callchain requests. 4215 */ 4216 4217 ps = psb->ps_samples; 4218 for (i = 0; i < pmc_nsamples; i++, ps++) { 4219 4220 if (ps->ps_nsamples != PMC_SAMPLE_INUSE) 4221 continue; 4222 if (ps->ps_td != td) 4223 continue; 4224 4225 KASSERT(ps->ps_cpu == cpu, 4226 ("[pmc,%d] cpu mismatch ps_cpu=%d pcpu=%d", __LINE__, 4227 ps->ps_cpu, PCPU_GET(cpuid))); 4228 4229 pm = ps->ps_pmc; 4230 4231 KASSERT(pm->pm_flags & PMC_F_CALLCHAIN, 4232 ("[pmc,%d] Retrieving callchain for PMC that doesn't " 4233 "want it", __LINE__)); 4234 4235 KASSERT(pm->pm_runcount > 0, 4236 ("[pmc,%d] runcount %d", __LINE__, pm->pm_runcount)); 4237 4238 /* 4239 * Retrieve the callchain and mark the sample buffer 4240 * as 'processable' by the timer tick sweep code. 4241 */ 4242 ps->ps_nsamples = pmc_save_user_callchain(ps->ps_pc, 4243 pmc_callchaindepth, tf); 4244 4245 #ifdef INVARIANTS 4246 ncallchains++; 4247 #endif 4248 } 4249 4250 KASSERT(ncallchains > 0, 4251 ("[pmc,%d] cpu %d didn't find a sample to collect", __LINE__, 4252 cpu)); 4253 4254 KASSERT(td->td_pinned > 0, 4255 ("[pmc,%d] invalid td_pinned value", __LINE__)); 4256 sched_unpin(); /* Can migrate safely now. */ 4257 4258 return; 4259 } 4260 4261 /* 4262 * Process saved PC samples. 4263 */ 4264 4265 static void 4266 pmc_process_samples(int cpu, int ring) 4267 { 4268 struct pmc *pm; 4269 int adjri, n; 4270 struct thread *td; 4271 struct pmc_owner *po; 4272 struct pmc_sample *ps; 4273 struct pmc_classdep *pcd; 4274 struct pmc_samplebuffer *psb; 4275 4276 KASSERT(PCPU_GET(cpuid) == cpu, 4277 ("[pmc,%d] not on the correct CPU pcpu=%d cpu=%d", __LINE__, 4278 PCPU_GET(cpuid), cpu)); 4279 4280 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4281 4282 for (n = 0; n < pmc_nsamples; n++) { /* bound on #iterations */ 4283 4284 ps = psb->ps_read; 4285 if (ps->ps_nsamples == PMC_SAMPLE_FREE) 4286 break; 4287 4288 pm = ps->ps_pmc; 4289 4290 KASSERT(pm->pm_runcount > 0, 4291 ("[pmc,%d] pm=%p runcount %d", __LINE__, (void *) pm, 4292 pm->pm_runcount)); 4293 4294 po = pm->pm_owner; 4295 4296 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 4297 ("[pmc,%d] pmc=%p non-sampling mode=%d", __LINE__, 4298 pm, PMC_TO_MODE(pm))); 4299 4300 /* Ignore PMCs that have been switched off */ 4301 if (pm->pm_state != PMC_STATE_RUNNING) 4302 goto entrydone; 4303 4304 /* If there is a pending AST wait for completion */ 4305 if (ps->ps_nsamples == PMC_SAMPLE_INUSE) { 4306 /* Need a rescan at a later time. */ 4307 CPU_SET_ATOMIC(cpu, &pmc_cpumask); 4308 break; 4309 } 4310 4311 PMCDBG(SAM,OPS,1,"cpu=%d pm=%p n=%d fl=%x wr=%d rd=%d", cpu, 4312 pm, ps->ps_nsamples, ps->ps_flags, 4313 (int) (psb->ps_write - psb->ps_samples), 4314 (int) (psb->ps_read - psb->ps_samples)); 4315 4316 /* 4317 * If this is a process-mode PMC that is attached to 4318 * its owner, and if the PC is in user mode, update 4319 * profiling statistics like timer-based profiling 4320 * would have done. 4321 */ 4322 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) { 4323 if (ps->ps_flags & PMC_CC_F_USERSPACE) { 4324 td = FIRST_THREAD_IN_PROC(po->po_owner); 4325 addupc_intr(td, ps->ps_pc[0], 1); 4326 } 4327 goto entrydone; 4328 } 4329 4330 /* 4331 * Otherwise, this is either a sampling mode PMC that 4332 * is attached to a different process than its owner, 4333 * or a system-wide sampling PMC. Dispatch a log 4334 * entry to the PMC's owner process. 4335 */ 4336 pmclog_process_callchain(pm, ps); 4337 4338 entrydone: 4339 ps->ps_nsamples = 0; /* mark entry as free */ 4340 atomic_subtract_rel_int(&pm->pm_runcount, 1); 4341 4342 /* increment read pointer, modulo sample size */ 4343 if (++ps == psb->ps_fence) 4344 psb->ps_read = psb->ps_samples; 4345 else 4346 psb->ps_read = ps; 4347 } 4348 4349 atomic_add_int(&pmc_stats.pm_log_sweeps, 1); 4350 4351 /* Do not re-enable stalled PMCs if we failed to process any samples */ 4352 if (n == 0) 4353 return; 4354 4355 /* 4356 * Restart any stalled sampling PMCs on this CPU. 4357 * 4358 * If the NMI handler sets the pm_stalled field of a PMC after 4359 * the check below, we'll end up processing the stalled PMC at 4360 * the next hardclock tick. 4361 */ 4362 for (n = 0; n < md->pmd_npmc; n++) { 4363 pcd = pmc_ri_to_classdep(md, n, &adjri); 4364 KASSERT(pcd != NULL, 4365 ("[pmc,%d] null pcd ri=%d", __LINE__, n)); 4366 (void) (*pcd->pcd_get_config)(cpu,adjri,&pm); 4367 4368 if (pm == NULL || /* !cfg'ed */ 4369 pm->pm_state != PMC_STATE_RUNNING || /* !active */ 4370 !PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) || /* !sampling */ 4371 pm->pm_stalled == 0) /* !stalled */ 4372 continue; 4373 4374 pm->pm_stalled = 0; 4375 (*pcd->pcd_start_pmc)(cpu, adjri); 4376 } 4377 } 4378 4379 /* 4380 * Event handlers. 4381 */ 4382 4383 /* 4384 * Handle a process exit. 4385 * 4386 * Remove this process from all hash tables. If this process 4387 * owned any PMCs, turn off those PMCs and deallocate them, 4388 * removing any associations with target processes. 4389 * 4390 * This function will be called by the last 'thread' of a 4391 * process. 4392 * 4393 * XXX This eventhandler gets called early in the exit process. 4394 * Consider using a 'hook' invocation from thread_exit() or equivalent 4395 * spot. Another negative is that kse_exit doesn't seem to call 4396 * exit1() [??]. 4397 * 4398 */ 4399 4400 static void 4401 pmc_process_exit(void *arg __unused, struct proc *p) 4402 { 4403 struct pmc *pm; 4404 int adjri, cpu; 4405 unsigned int ri; 4406 int is_using_hwpmcs; 4407 struct pmc_owner *po; 4408 struct pmc_process *pp; 4409 struct pmc_classdep *pcd; 4410 pmc_value_t newvalue, tmp; 4411 4412 PROC_LOCK(p); 4413 is_using_hwpmcs = p->p_flag & P_HWPMC; 4414 PROC_UNLOCK(p); 4415 4416 /* 4417 * Log a sysexit event to all SS PMC owners. 4418 */ 4419 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4420 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4421 pmclog_process_sysexit(po, p->p_pid); 4422 4423 if (!is_using_hwpmcs) 4424 return; 4425 4426 PMC_GET_SX_XLOCK(); 4427 PMCDBG(PRC,EXT,1,"process-exit proc=%p (%d, %s)", p, p->p_pid, 4428 p->p_comm); 4429 4430 /* 4431 * Since this code is invoked by the last thread in an exiting 4432 * process, we would have context switched IN at some prior 4433 * point. However, with PREEMPTION, kernel mode context 4434 * switches may happen any time, so we want to disable a 4435 * context switch OUT till we get any PMCs targetting this 4436 * process off the hardware. 4437 * 4438 * We also need to atomically remove this process' 4439 * entry from our target process hash table, using 4440 * PMC_FLAG_REMOVE. 4441 */ 4442 PMCDBG(PRC,EXT,1, "process-exit proc=%p (%d, %s)", p, p->p_pid, 4443 p->p_comm); 4444 4445 critical_enter(); /* no preemption */ 4446 4447 cpu = curthread->td_oncpu; 4448 4449 if ((pp = pmc_find_process_descriptor(p, 4450 PMC_FLAG_REMOVE)) != NULL) { 4451 4452 PMCDBG(PRC,EXT,2, 4453 "process-exit proc=%p pmc-process=%p", p, pp); 4454 4455 /* 4456 * The exiting process could the target of 4457 * some PMCs which will be running on 4458 * currently executing CPU. 4459 * 4460 * We need to turn these PMCs off like we 4461 * would do at context switch OUT time. 4462 */ 4463 for (ri = 0; ri < md->pmd_npmc; ri++) { 4464 4465 /* 4466 * Pick up the pmc pointer from hardware 4467 * state similar to the CSW_OUT code. 4468 */ 4469 pm = NULL; 4470 4471 pcd = pmc_ri_to_classdep(md, ri, &adjri); 4472 4473 (void) (*pcd->pcd_get_config)(cpu, adjri, &pm); 4474 4475 PMCDBG(PRC,EXT,2, "ri=%d pm=%p", ri, pm); 4476 4477 if (pm == NULL || 4478 !PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 4479 continue; 4480 4481 PMCDBG(PRC,EXT,2, "ppmcs[%d]=%p pm=%p " 4482 "state=%d", ri, pp->pp_pmcs[ri].pp_pmc, 4483 pm, pm->pm_state); 4484 4485 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 4486 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 4487 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 4488 4489 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 4490 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", 4491 __LINE__, pm, ri, pp->pp_pmcs[ri].pp_pmc)); 4492 4493 (void) pcd->pcd_stop_pmc(cpu, adjri); 4494 4495 KASSERT(pm->pm_runcount > 0, 4496 ("[pmc,%d] bad runcount ri %d rc %d", 4497 __LINE__, ri, pm->pm_runcount)); 4498 4499 /* Stop hardware only if it is actually running */ 4500 if (pm->pm_state == PMC_STATE_RUNNING && 4501 pm->pm_stalled == 0) { 4502 pcd->pcd_read_pmc(cpu, adjri, &newvalue); 4503 tmp = newvalue - 4504 PMC_PCPU_SAVED(cpu,ri); 4505 4506 mtx_pool_lock_spin(pmc_mtxpool, pm); 4507 pm->pm_gv.pm_savedvalue += tmp; 4508 pp->pp_pmcs[ri].pp_pmcval += tmp; 4509 mtx_pool_unlock_spin(pmc_mtxpool, pm); 4510 } 4511 4512 atomic_subtract_rel_int(&pm->pm_runcount,1); 4513 4514 KASSERT((int) pm->pm_runcount >= 0, 4515 ("[pmc,%d] runcount is %d", __LINE__, ri)); 4516 4517 (void) pcd->pcd_config_pmc(cpu, adjri, NULL); 4518 } 4519 4520 /* 4521 * Inform the MD layer of this pseudo "context switch 4522 * out" 4523 */ 4524 (void) md->pmd_switch_out(pmc_pcpu[cpu], pp); 4525 4526 critical_exit(); /* ok to be pre-empted now */ 4527 4528 /* 4529 * Unlink this process from the PMCs that are 4530 * targetting it. This will send a signal to 4531 * all PMC owner's whose PMCs are orphaned. 4532 * 4533 * Log PMC value at exit time if requested. 4534 */ 4535 for (ri = 0; ri < md->pmd_npmc; ri++) 4536 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 4537 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 4538 PMC_IS_COUNTING_MODE(PMC_TO_MODE(pm))) 4539 pmclog_process_procexit(pm, pp); 4540 pmc_unlink_target_process(pm, pp); 4541 } 4542 free(pp, M_PMC); 4543 4544 } else 4545 critical_exit(); /* pp == NULL */ 4546 4547 4548 /* 4549 * If the process owned PMCs, free them up and free up 4550 * memory. 4551 */ 4552 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 4553 pmc_remove_owner(po); 4554 pmc_destroy_owner_descriptor(po); 4555 } 4556 4557 sx_xunlock(&pmc_sx); 4558 } 4559 4560 /* 4561 * Handle a process fork. 4562 * 4563 * If the parent process 'p1' is under HWPMC monitoring, then copy 4564 * over any attached PMCs that have 'do_descendants' semantics. 4565 */ 4566 4567 static void 4568 pmc_process_fork(void *arg __unused, struct proc *p1, struct proc *newproc, 4569 int flags) 4570 { 4571 int is_using_hwpmcs; 4572 unsigned int ri; 4573 uint32_t do_descendants; 4574 struct pmc *pm; 4575 struct pmc_owner *po; 4576 struct pmc_process *ppnew, *ppold; 4577 4578 (void) flags; /* unused parameter */ 4579 4580 PROC_LOCK(p1); 4581 is_using_hwpmcs = p1->p_flag & P_HWPMC; 4582 PROC_UNLOCK(p1); 4583 4584 /* 4585 * If there are system-wide sampling PMCs active, we need to 4586 * log all fork events to their owner's logs. 4587 */ 4588 4589 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4590 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4591 pmclog_process_procfork(po, p1->p_pid, newproc->p_pid); 4592 4593 if (!is_using_hwpmcs) 4594 return; 4595 4596 PMC_GET_SX_XLOCK(); 4597 PMCDBG(PMC,FRK,1, "process-fork proc=%p (%d, %s) -> %p", p1, 4598 p1->p_pid, p1->p_comm, newproc); 4599 4600 /* 4601 * If the parent process (curthread->td_proc) is a 4602 * target of any PMCs, look for PMCs that are to be 4603 * inherited, and link these into the new process 4604 * descriptor. 4605 */ 4606 if ((ppold = pmc_find_process_descriptor(curthread->td_proc, 4607 PMC_FLAG_NONE)) == NULL) 4608 goto done; /* nothing to do */ 4609 4610 do_descendants = 0; 4611 for (ri = 0; ri < md->pmd_npmc; ri++) 4612 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL) 4613 do_descendants |= pm->pm_flags & PMC_F_DESCENDANTS; 4614 if (do_descendants == 0) /* nothing to do */ 4615 goto done; 4616 4617 /* allocate a descriptor for the new process */ 4618 if ((ppnew = pmc_find_process_descriptor(newproc, 4619 PMC_FLAG_ALLOCATE)) == NULL) 4620 goto done; 4621 4622 /* 4623 * Run through all PMCs that were targeting the old process 4624 * and which specified F_DESCENDANTS and attach them to the 4625 * new process. 4626 * 4627 * Log the fork event to all owners of PMCs attached to this 4628 * process, if not already logged. 4629 */ 4630 for (ri = 0; ri < md->pmd_npmc; ri++) 4631 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL && 4632 (pm->pm_flags & PMC_F_DESCENDANTS)) { 4633 pmc_link_target_process(pm, ppnew); 4634 po = pm->pm_owner; 4635 if (po->po_sscount == 0 && 4636 po->po_flags & PMC_PO_OWNS_LOGFILE) 4637 pmclog_process_procfork(po, p1->p_pid, 4638 newproc->p_pid); 4639 } 4640 4641 /* 4642 * Now mark the new process as being tracked by this driver. 4643 */ 4644 PROC_LOCK(newproc); 4645 newproc->p_flag |= P_HWPMC; 4646 PROC_UNLOCK(newproc); 4647 4648 done: 4649 sx_xunlock(&pmc_sx); 4650 } 4651 4652 4653 /* 4654 * initialization 4655 */ 4656 4657 static const char *pmc_name_of_pmcclass[] = { 4658 #undef __PMC_CLASS 4659 #define __PMC_CLASS(N) #N , 4660 __PMC_CLASSES() 4661 }; 4662 4663 /* 4664 * Base class initializer: allocate structure and set default classes. 4665 */ 4666 struct pmc_mdep * 4667 pmc_mdep_alloc(int nclasses) 4668 { 4669 struct pmc_mdep *md; 4670 int n; 4671 4672 /* SOFT + md classes */ 4673 n = 1 + nclasses; 4674 md = malloc(sizeof(struct pmc_mdep) + n * 4675 sizeof(struct pmc_classdep), M_PMC, M_WAITOK|M_ZERO); 4676 if (md != NULL) { 4677 md->pmd_nclass = n; 4678 4679 /* Add base class. */ 4680 pmc_soft_initialize(md); 4681 } 4682 4683 return md; 4684 } 4685 4686 void 4687 pmc_mdep_free(struct pmc_mdep *md) 4688 { 4689 pmc_soft_finalize(md); 4690 free(md, M_PMC); 4691 } 4692 4693 static int 4694 generic_switch_in(struct pmc_cpu *pc, struct pmc_process *pp) 4695 { 4696 (void) pc; (void) pp; 4697 4698 return (0); 4699 } 4700 4701 static int 4702 generic_switch_out(struct pmc_cpu *pc, struct pmc_process *pp) 4703 { 4704 (void) pc; (void) pp; 4705 4706 return (0); 4707 } 4708 4709 static struct pmc_mdep * 4710 pmc_generic_cpu_initialize(void) 4711 { 4712 struct pmc_mdep *md; 4713 4714 md = pmc_mdep_alloc(0); 4715 4716 md->pmd_cputype = PMC_CPU_GENERIC; 4717 4718 md->pmd_pcpu_init = NULL; 4719 md->pmd_pcpu_fini = NULL; 4720 md->pmd_switch_in = generic_switch_in; 4721 md->pmd_switch_out = generic_switch_out; 4722 4723 return (md); 4724 } 4725 4726 static void 4727 pmc_generic_cpu_finalize(struct pmc_mdep *md) 4728 { 4729 (void) md; 4730 } 4731 4732 4733 static int 4734 pmc_initialize(void) 4735 { 4736 int c, cpu, error, n, ri; 4737 unsigned int maxcpu; 4738 struct pmc_binding pb; 4739 struct pmc_sample *ps; 4740 struct pmc_classdep *pcd; 4741 struct pmc_samplebuffer *sb; 4742 4743 md = NULL; 4744 error = 0; 4745 4746 #ifdef DEBUG 4747 /* parse debug flags first */ 4748 if (TUNABLE_STR_FETCH(PMC_SYSCTL_NAME_PREFIX "debugflags", 4749 pmc_debugstr, sizeof(pmc_debugstr))) 4750 pmc_debugflags_parse(pmc_debugstr, 4751 pmc_debugstr+strlen(pmc_debugstr)); 4752 #endif 4753 4754 PMCDBG(MOD,INI,0, "PMC Initialize (version %x)", PMC_VERSION); 4755 4756 /* check kernel version */ 4757 if (pmc_kernel_version != PMC_VERSION) { 4758 if (pmc_kernel_version == 0) 4759 printf("hwpmc: this kernel has not been compiled with " 4760 "'options HWPMC_HOOKS'.\n"); 4761 else 4762 printf("hwpmc: kernel version (0x%x) does not match " 4763 "module version (0x%x).\n", pmc_kernel_version, 4764 PMC_VERSION); 4765 return EPROGMISMATCH; 4766 } 4767 4768 /* 4769 * check sysctl parameters 4770 */ 4771 4772 if (pmc_hashsize <= 0) { 4773 (void) printf("hwpmc: tunable \"hashsize\"=%d must be " 4774 "greater than zero.\n", pmc_hashsize); 4775 pmc_hashsize = PMC_HASH_SIZE; 4776 } 4777 4778 if (pmc_nsamples <= 0 || pmc_nsamples > 65535) { 4779 (void) printf("hwpmc: tunable \"nsamples\"=%d out of " 4780 "range.\n", pmc_nsamples); 4781 pmc_nsamples = PMC_NSAMPLES; 4782 } 4783 4784 if (pmc_callchaindepth <= 0 || 4785 pmc_callchaindepth > PMC_CALLCHAIN_DEPTH_MAX) { 4786 (void) printf("hwpmc: tunable \"callchaindepth\"=%d out of " 4787 "range.\n", pmc_callchaindepth); 4788 pmc_callchaindepth = PMC_CALLCHAIN_DEPTH; 4789 } 4790 4791 md = pmc_md_initialize(); 4792 if (md == NULL) { 4793 /* Default to generic CPU. */ 4794 md = pmc_generic_cpu_initialize(); 4795 if (md == NULL) 4796 return (ENOSYS); 4797 } 4798 4799 KASSERT(md->pmd_nclass >= 1 && md->pmd_npmc >= 1, 4800 ("[pmc,%d] no classes or pmcs", __LINE__)); 4801 4802 /* Compute the map from row-indices to classdep pointers. */ 4803 pmc_rowindex_to_classdep = malloc(sizeof(struct pmc_classdep *) * 4804 md->pmd_npmc, M_PMC, M_WAITOK|M_ZERO); 4805 4806 for (n = 0; n < md->pmd_npmc; n++) 4807 pmc_rowindex_to_classdep[n] = NULL; 4808 for (ri = c = 0; c < md->pmd_nclass; c++) { 4809 pcd = &md->pmd_classdep[c]; 4810 for (n = 0; n < pcd->pcd_num; n++, ri++) 4811 pmc_rowindex_to_classdep[ri] = pcd; 4812 } 4813 4814 KASSERT(ri == md->pmd_npmc, 4815 ("[pmc,%d] npmc miscomputed: ri=%d, md->npmc=%d", __LINE__, 4816 ri, md->pmd_npmc)); 4817 4818 maxcpu = pmc_cpu_max(); 4819 4820 /* allocate space for the per-cpu array */ 4821 pmc_pcpu = malloc(maxcpu * sizeof(struct pmc_cpu *), M_PMC, 4822 M_WAITOK|M_ZERO); 4823 4824 /* per-cpu 'saved values' for managing process-mode PMCs */ 4825 pmc_pcpu_saved = malloc(sizeof(pmc_value_t) * maxcpu * md->pmd_npmc, 4826 M_PMC, M_WAITOK); 4827 4828 /* Perform CPU-dependent initialization. */ 4829 pmc_save_cpu_binding(&pb); 4830 error = 0; 4831 for (cpu = 0; error == 0 && cpu < maxcpu; cpu++) { 4832 if (!pmc_cpu_is_active(cpu)) 4833 continue; 4834 pmc_select_cpu(cpu); 4835 pmc_pcpu[cpu] = malloc(sizeof(struct pmc_cpu) + 4836 md->pmd_npmc * sizeof(struct pmc_hw *), M_PMC, 4837 M_WAITOK|M_ZERO); 4838 if (md->pmd_pcpu_init) 4839 error = md->pmd_pcpu_init(md, cpu); 4840 for (n = 0; error == 0 && n < md->pmd_nclass; n++) 4841 error = md->pmd_classdep[n].pcd_pcpu_init(md, cpu); 4842 } 4843 pmc_restore_cpu_binding(&pb); 4844 4845 if (error) 4846 return (error); 4847 4848 /* allocate space for the sample array */ 4849 for (cpu = 0; cpu < maxcpu; cpu++) { 4850 if (!pmc_cpu_is_active(cpu)) 4851 continue; 4852 4853 sb = malloc(sizeof(struct pmc_samplebuffer) + 4854 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 4855 M_WAITOK|M_ZERO); 4856 sb->ps_read = sb->ps_write = sb->ps_samples; 4857 sb->ps_fence = sb->ps_samples + pmc_nsamples; 4858 4859 KASSERT(pmc_pcpu[cpu] != NULL, 4860 ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu)); 4861 4862 sb->ps_callchains = malloc(pmc_callchaindepth * pmc_nsamples * 4863 sizeof(uintptr_t), M_PMC, M_WAITOK|M_ZERO); 4864 4865 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 4866 ps->ps_pc = sb->ps_callchains + 4867 (n * pmc_callchaindepth); 4868 4869 pmc_pcpu[cpu]->pc_sb[PMC_HR] = sb; 4870 4871 sb = malloc(sizeof(struct pmc_samplebuffer) + 4872 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 4873 M_WAITOK|M_ZERO); 4874 sb->ps_read = sb->ps_write = sb->ps_samples; 4875 sb->ps_fence = sb->ps_samples + pmc_nsamples; 4876 4877 KASSERT(pmc_pcpu[cpu] != NULL, 4878 ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu)); 4879 4880 sb->ps_callchains = malloc(pmc_callchaindepth * pmc_nsamples * 4881 sizeof(uintptr_t), M_PMC, M_WAITOK|M_ZERO); 4882 4883 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 4884 ps->ps_pc = sb->ps_callchains + 4885 (n * pmc_callchaindepth); 4886 4887 pmc_pcpu[cpu]->pc_sb[PMC_SR] = sb; 4888 } 4889 4890 /* allocate space for the row disposition array */ 4891 pmc_pmcdisp = malloc(sizeof(enum pmc_mode) * md->pmd_npmc, 4892 M_PMC, M_WAITOK|M_ZERO); 4893 4894 KASSERT(pmc_pmcdisp != NULL, 4895 ("[pmc,%d] pmcdisp allocation returned NULL", __LINE__)); 4896 4897 /* mark all PMCs as available */ 4898 for (n = 0; n < (int) md->pmd_npmc; n++) 4899 PMC_MARK_ROW_FREE(n); 4900 4901 /* allocate thread hash tables */ 4902 pmc_ownerhash = hashinit(pmc_hashsize, M_PMC, 4903 &pmc_ownerhashmask); 4904 4905 pmc_processhash = hashinit(pmc_hashsize, M_PMC, 4906 &pmc_processhashmask); 4907 mtx_init(&pmc_processhash_mtx, "pmc-process-hash", "pmc-leaf", 4908 MTX_SPIN); 4909 4910 LIST_INIT(&pmc_ss_owners); 4911 pmc_ss_count = 0; 4912 4913 /* allocate a pool of spin mutexes */ 4914 pmc_mtxpool = mtx_pool_create("pmc-leaf", pmc_mtxpool_size, 4915 MTX_SPIN); 4916 4917 PMCDBG(MOD,INI,1, "pmc_ownerhash=%p, mask=0x%lx " 4918 "targethash=%p mask=0x%lx", pmc_ownerhash, pmc_ownerhashmask, 4919 pmc_processhash, pmc_processhashmask); 4920 4921 /* register process {exit,fork,exec} handlers */ 4922 pmc_exit_tag = EVENTHANDLER_REGISTER(process_exit, 4923 pmc_process_exit, NULL, EVENTHANDLER_PRI_ANY); 4924 pmc_fork_tag = EVENTHANDLER_REGISTER(process_fork, 4925 pmc_process_fork, NULL, EVENTHANDLER_PRI_ANY); 4926 4927 /* initialize logging */ 4928 pmclog_initialize(); 4929 4930 /* set hook functions */ 4931 pmc_intr = md->pmd_intr; 4932 pmc_hook = pmc_hook_handler; 4933 4934 if (error == 0) { 4935 printf(PMC_MODULE_NAME ":"); 4936 for (n = 0; n < (int) md->pmd_nclass; n++) { 4937 pcd = &md->pmd_classdep[n]; 4938 printf(" %s/%d/%d/0x%b", 4939 pmc_name_of_pmcclass[pcd->pcd_class], 4940 pcd->pcd_num, 4941 pcd->pcd_width, 4942 pcd->pcd_caps, 4943 "\20" 4944 "\1INT\2USR\3SYS\4EDG\5THR" 4945 "\6REA\7WRI\10INV\11QUA\12PRC" 4946 "\13TAG\14CSC"); 4947 } 4948 printf("\n"); 4949 } 4950 4951 return (error); 4952 } 4953 4954 /* prepare to be unloaded */ 4955 static void 4956 pmc_cleanup(void) 4957 { 4958 int c, cpu; 4959 unsigned int maxcpu; 4960 struct pmc_ownerhash *ph; 4961 struct pmc_owner *po, *tmp; 4962 struct pmc_binding pb; 4963 #ifdef DEBUG 4964 struct pmc_processhash *prh; 4965 #endif 4966 4967 PMCDBG(MOD,INI,0, "%s", "cleanup"); 4968 4969 /* switch off sampling */ 4970 CPU_ZERO(&pmc_cpumask); 4971 pmc_intr = NULL; 4972 4973 sx_xlock(&pmc_sx); 4974 if (pmc_hook == NULL) { /* being unloaded already */ 4975 sx_xunlock(&pmc_sx); 4976 return; 4977 } 4978 4979 pmc_hook = NULL; /* prevent new threads from entering module */ 4980 4981 /* deregister event handlers */ 4982 EVENTHANDLER_DEREGISTER(process_fork, pmc_fork_tag); 4983 EVENTHANDLER_DEREGISTER(process_exit, pmc_exit_tag); 4984 4985 /* send SIGBUS to all owner threads, free up allocations */ 4986 if (pmc_ownerhash) 4987 for (ph = pmc_ownerhash; 4988 ph <= &pmc_ownerhash[pmc_ownerhashmask]; 4989 ph++) { 4990 LIST_FOREACH_SAFE(po, ph, po_next, tmp) { 4991 pmc_remove_owner(po); 4992 4993 /* send SIGBUS to owner processes */ 4994 PMCDBG(MOD,INI,2, "cleanup signal proc=%p " 4995 "(%d, %s)", po->po_owner, 4996 po->po_owner->p_pid, 4997 po->po_owner->p_comm); 4998 4999 PROC_LOCK(po->po_owner); 5000 kern_psignal(po->po_owner, SIGBUS); 5001 PROC_UNLOCK(po->po_owner); 5002 5003 pmc_destroy_owner_descriptor(po); 5004 } 5005 } 5006 5007 /* reclaim allocated data structures */ 5008 if (pmc_mtxpool) 5009 mtx_pool_destroy(&pmc_mtxpool); 5010 5011 mtx_destroy(&pmc_processhash_mtx); 5012 if (pmc_processhash) { 5013 #ifdef DEBUG 5014 struct pmc_process *pp; 5015 5016 PMCDBG(MOD,INI,3, "%s", "destroy process hash"); 5017 for (prh = pmc_processhash; 5018 prh <= &pmc_processhash[pmc_processhashmask]; 5019 prh++) 5020 LIST_FOREACH(pp, prh, pp_next) 5021 PMCDBG(MOD,INI,3, "pid=%d", pp->pp_proc->p_pid); 5022 #endif 5023 5024 hashdestroy(pmc_processhash, M_PMC, pmc_processhashmask); 5025 pmc_processhash = NULL; 5026 } 5027 5028 if (pmc_ownerhash) { 5029 PMCDBG(MOD,INI,3, "%s", "destroy owner hash"); 5030 hashdestroy(pmc_ownerhash, M_PMC, pmc_ownerhashmask); 5031 pmc_ownerhash = NULL; 5032 } 5033 5034 KASSERT(LIST_EMPTY(&pmc_ss_owners), 5035 ("[pmc,%d] Global SS owner list not empty", __LINE__)); 5036 KASSERT(pmc_ss_count == 0, 5037 ("[pmc,%d] Global SS count not empty", __LINE__)); 5038 5039 /* do processor and pmc-class dependent cleanup */ 5040 maxcpu = pmc_cpu_max(); 5041 5042 PMCDBG(MOD,INI,3, "%s", "md cleanup"); 5043 if (md) { 5044 pmc_save_cpu_binding(&pb); 5045 for (cpu = 0; cpu < maxcpu; cpu++) { 5046 PMCDBG(MOD,INI,1,"pmc-cleanup cpu=%d pcs=%p", 5047 cpu, pmc_pcpu[cpu]); 5048 if (!pmc_cpu_is_active(cpu) || pmc_pcpu[cpu] == NULL) 5049 continue; 5050 pmc_select_cpu(cpu); 5051 for (c = 0; c < md->pmd_nclass; c++) 5052 md->pmd_classdep[c].pcd_pcpu_fini(md, cpu); 5053 if (md->pmd_pcpu_fini) 5054 md->pmd_pcpu_fini(md, cpu); 5055 } 5056 5057 if (md->pmd_cputype == PMC_CPU_GENERIC) 5058 pmc_generic_cpu_finalize(md); 5059 else 5060 pmc_md_finalize(md); 5061 5062 pmc_mdep_free(md); 5063 md = NULL; 5064 pmc_restore_cpu_binding(&pb); 5065 } 5066 5067 /* Free per-cpu descriptors. */ 5068 for (cpu = 0; cpu < maxcpu; cpu++) { 5069 if (!pmc_cpu_is_active(cpu)) 5070 continue; 5071 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_HR] != NULL, 5072 ("[pmc,%d] Null hw cpu sample buffer cpu=%d", __LINE__, 5073 cpu)); 5074 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_SR] != NULL, 5075 ("[pmc,%d] Null sw cpu sample buffer cpu=%d", __LINE__, 5076 cpu)); 5077 free(pmc_pcpu[cpu]->pc_sb[PMC_HR]->ps_callchains, M_PMC); 5078 free(pmc_pcpu[cpu]->pc_sb[PMC_HR], M_PMC); 5079 free(pmc_pcpu[cpu]->pc_sb[PMC_SR]->ps_callchains, M_PMC); 5080 free(pmc_pcpu[cpu]->pc_sb[PMC_SR], M_PMC); 5081 free(pmc_pcpu[cpu], M_PMC); 5082 } 5083 5084 free(pmc_pcpu, M_PMC); 5085 pmc_pcpu = NULL; 5086 5087 free(pmc_pcpu_saved, M_PMC); 5088 pmc_pcpu_saved = NULL; 5089 5090 if (pmc_pmcdisp) { 5091 free(pmc_pmcdisp, M_PMC); 5092 pmc_pmcdisp = NULL; 5093 } 5094 5095 if (pmc_rowindex_to_classdep) { 5096 free(pmc_rowindex_to_classdep, M_PMC); 5097 pmc_rowindex_to_classdep = NULL; 5098 } 5099 5100 pmclog_shutdown(); 5101 5102 sx_xunlock(&pmc_sx); /* we are done */ 5103 } 5104 5105 /* 5106 * The function called at load/unload. 5107 */ 5108 5109 static int 5110 load (struct module *module __unused, int cmd, void *arg __unused) 5111 { 5112 int error; 5113 5114 error = 0; 5115 5116 switch (cmd) { 5117 case MOD_LOAD : 5118 /* initialize the subsystem */ 5119 error = pmc_initialize(); 5120 if (error != 0) 5121 break; 5122 PMCDBG(MOD,INI,1, "syscall=%d maxcpu=%d", 5123 pmc_syscall_num, pmc_cpu_max()); 5124 break; 5125 5126 5127 case MOD_UNLOAD : 5128 case MOD_SHUTDOWN: 5129 pmc_cleanup(); 5130 PMCDBG(MOD,INI,1, "%s", "unloaded"); 5131 break; 5132 5133 default : 5134 error = EINVAL; /* XXX should panic(9) */ 5135 break; 5136 } 5137 5138 return error; 5139 } 5140 5141 /* memory pool */ 5142 MALLOC_DEFINE(M_PMC, "pmc", "Memory space for the PMC module"); 5143