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/mutex.h> 45 #include <sys/pmc.h> 46 #include <sys/pmckern.h> 47 #include <sys/pmclog.h> 48 #include <sys/priv.h> 49 #include <sys/proc.h> 50 #include <sys/queue.h> 51 #include <sys/resourcevar.h> 52 #include <sys/sched.h> 53 #include <sys/signalvar.h> 54 #include <sys/smp.h> 55 #include <sys/sx.h> 56 #include <sys/sysctl.h> 57 #include <sys/sysent.h> 58 #include <sys/systm.h> 59 #include <sys/vnode.h> 60 61 #include <sys/linker.h> /* needs to be after <sys/malloc.h> */ 62 63 #include <machine/atomic.h> 64 #include <machine/md_var.h> 65 66 #include <vm/vm.h> 67 #include <vm/vm_extern.h> 68 #include <vm/pmap.h> 69 #include <vm/vm_map.h> 70 #include <vm/vm_object.h> 71 72 /* 73 * Types 74 */ 75 76 enum pmc_flags { 77 PMC_FLAG_NONE = 0x00, /* do nothing */ 78 PMC_FLAG_REMOVE = 0x01, /* atomically remove entry from hash */ 79 PMC_FLAG_ALLOCATE = 0x02, /* add entry to hash if not found */ 80 }; 81 82 /* 83 * The offset in sysent where the syscall is allocated. 84 */ 85 86 static int pmc_syscall_num = NO_SYSCALL; 87 struct pmc_cpu **pmc_pcpu; /* per-cpu state */ 88 pmc_value_t *pmc_pcpu_saved; /* saved PMC values: CSW handling */ 89 90 #define PMC_PCPU_SAVED(C,R) pmc_pcpu_saved[(R) + md->pmd_npmc*(C)] 91 92 struct mtx_pool *pmc_mtxpool; 93 static int *pmc_pmcdisp; /* PMC row dispositions */ 94 95 #define PMC_ROW_DISP_IS_FREE(R) (pmc_pmcdisp[(R)] == 0) 96 #define PMC_ROW_DISP_IS_THREAD(R) (pmc_pmcdisp[(R)] > 0) 97 #define PMC_ROW_DISP_IS_STANDALONE(R) (pmc_pmcdisp[(R)] < 0) 98 99 #define PMC_MARK_ROW_FREE(R) do { \ 100 pmc_pmcdisp[(R)] = 0; \ 101 } while (0) 102 103 #define PMC_MARK_ROW_STANDALONE(R) do { \ 104 KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \ 105 __LINE__)); \ 106 atomic_add_int(&pmc_pmcdisp[(R)], -1); \ 107 KASSERT(pmc_pmcdisp[(R)] >= (-pmc_cpu_max_active()), \ 108 ("[pmc,%d] row disposition error", __LINE__)); \ 109 } while (0) 110 111 #define PMC_UNMARK_ROW_STANDALONE(R) do { \ 112 atomic_add_int(&pmc_pmcdisp[(R)], 1); \ 113 KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \ 114 __LINE__)); \ 115 } while (0) 116 117 #define PMC_MARK_ROW_THREAD(R) do { \ 118 KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \ 119 __LINE__)); \ 120 atomic_add_int(&pmc_pmcdisp[(R)], 1); \ 121 } while (0) 122 123 #define PMC_UNMARK_ROW_THREAD(R) do { \ 124 atomic_add_int(&pmc_pmcdisp[(R)], -1); \ 125 KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \ 126 __LINE__)); \ 127 } while (0) 128 129 130 /* various event handlers */ 131 static eventhandler_tag pmc_exit_tag, pmc_fork_tag; 132 133 /* Module statistics */ 134 struct pmc_op_getdriverstats pmc_stats; 135 136 /* Machine/processor dependent operations */ 137 static struct pmc_mdep *md; 138 139 /* 140 * Hash tables mapping owner processes and target threads to PMCs. 141 */ 142 143 struct mtx pmc_processhash_mtx; /* spin mutex */ 144 static u_long pmc_processhashmask; 145 static LIST_HEAD(pmc_processhash, pmc_process) *pmc_processhash; 146 147 /* 148 * Hash table of PMC owner descriptors. This table is protected by 149 * the shared PMC "sx" lock. 150 */ 151 152 static u_long pmc_ownerhashmask; 153 static LIST_HEAD(pmc_ownerhash, pmc_owner) *pmc_ownerhash; 154 155 /* 156 * List of PMC owners with system-wide sampling PMCs. 157 */ 158 159 static LIST_HEAD(, pmc_owner) pmc_ss_owners; 160 161 162 /* 163 * A map of row indices to classdep structures. 164 */ 165 static struct pmc_classdep **pmc_rowindex_to_classdep; 166 167 /* 168 * Prototypes 169 */ 170 171 #ifdef DEBUG 172 static int pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS); 173 static int pmc_debugflags_parse(char *newstr, char *fence); 174 #endif 175 176 static int load(struct module *module, int cmd, void *arg); 177 static int pmc_attach_process(struct proc *p, struct pmc *pm); 178 static struct pmc *pmc_allocate_pmc_descriptor(void); 179 static struct pmc_owner *pmc_allocate_owner_descriptor(struct proc *p); 180 static int pmc_attach_one_process(struct proc *p, struct pmc *pm); 181 static int pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, 182 int cpu); 183 static int pmc_can_attach(struct pmc *pm, struct proc *p); 184 static void pmc_capture_user_callchain(int cpu, struct trapframe *tf); 185 static void pmc_cleanup(void); 186 static int pmc_detach_process(struct proc *p, struct pmc *pm); 187 static int pmc_detach_one_process(struct proc *p, struct pmc *pm, 188 int flags); 189 static void pmc_destroy_owner_descriptor(struct pmc_owner *po); 190 static struct pmc_owner *pmc_find_owner_descriptor(struct proc *p); 191 static int pmc_find_pmc(pmc_id_t pmcid, struct pmc **pm); 192 static struct pmc *pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, 193 pmc_id_t pmc); 194 static struct pmc_process *pmc_find_process_descriptor(struct proc *p, 195 uint32_t mode); 196 static void pmc_force_context_switch(void); 197 static void pmc_link_target_process(struct pmc *pm, 198 struct pmc_process *pp); 199 static void pmc_log_all_process_mappings(struct pmc_owner *po); 200 static void pmc_log_kernel_mappings(struct pmc *pm); 201 static void pmc_log_process_mappings(struct pmc_owner *po, struct proc *p); 202 static void pmc_maybe_remove_owner(struct pmc_owner *po); 203 static void pmc_process_csw_in(struct thread *td); 204 static void pmc_process_csw_out(struct thread *td); 205 static void pmc_process_exit(void *arg, struct proc *p); 206 static void pmc_process_fork(void *arg, struct proc *p1, 207 struct proc *p2, int n); 208 static void pmc_process_samples(int cpu); 209 static void pmc_release_pmc_descriptor(struct pmc *pmc); 210 static void pmc_remove_owner(struct pmc_owner *po); 211 static void pmc_remove_process_descriptor(struct pmc_process *pp); 212 static void pmc_restore_cpu_binding(struct pmc_binding *pb); 213 static void pmc_save_cpu_binding(struct pmc_binding *pb); 214 static void pmc_select_cpu(int cpu); 215 static int pmc_start(struct pmc *pm); 216 static int pmc_stop(struct pmc *pm); 217 static int pmc_syscall_handler(struct thread *td, void *syscall_args); 218 static void pmc_unlink_target_process(struct pmc *pmc, 219 struct pmc_process *pp); 220 221 /* 222 * Kernel tunables and sysctl(8) interface. 223 */ 224 225 SYSCTL_NODE(_kern, OID_AUTO, hwpmc, CTLFLAG_RW, 0, "HWPMC parameters"); 226 227 static int pmc_callchaindepth = PMC_CALLCHAIN_DEPTH; 228 TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "callchaindepth", &pmc_callchaindepth); 229 SYSCTL_INT(_kern_hwpmc, OID_AUTO, callchaindepth, CTLFLAG_TUN|CTLFLAG_RD, 230 &pmc_callchaindepth, 0, "depth of call chain records"); 231 232 #ifdef DEBUG 233 struct pmc_debugflags pmc_debugflags = PMC_DEBUG_DEFAULT_FLAGS; 234 char pmc_debugstr[PMC_DEBUG_STRSIZE]; 235 TUNABLE_STR(PMC_SYSCTL_NAME_PREFIX "debugflags", pmc_debugstr, 236 sizeof(pmc_debugstr)); 237 SYSCTL_PROC(_kern_hwpmc, OID_AUTO, debugflags, 238 CTLTYPE_STRING|CTLFLAG_RW|CTLFLAG_TUN, 239 0, 0, pmc_debugflags_sysctl_handler, "A", "debug flags"); 240 #endif 241 242 /* 243 * kern.hwpmc.hashrows -- determines the number of rows in the 244 * of the hash table used to look up threads 245 */ 246 247 static int pmc_hashsize = PMC_HASH_SIZE; 248 TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "hashsize", &pmc_hashsize); 249 SYSCTL_INT(_kern_hwpmc, OID_AUTO, hashsize, CTLFLAG_TUN|CTLFLAG_RD, 250 &pmc_hashsize, 0, "rows in hash tables"); 251 252 /* 253 * kern.hwpmc.nsamples --- number of PC samples/callchain stacks per CPU 254 */ 255 256 static int pmc_nsamples = PMC_NSAMPLES; 257 TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "nsamples", &pmc_nsamples); 258 SYSCTL_INT(_kern_hwpmc, OID_AUTO, nsamples, CTLFLAG_TUN|CTLFLAG_RD, 259 &pmc_nsamples, 0, "number of PC samples per CPU"); 260 261 262 /* 263 * kern.hwpmc.mtxpoolsize -- number of mutexes in the mutex pool. 264 */ 265 266 static int pmc_mtxpool_size = PMC_MTXPOOL_SIZE; 267 TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "mtxpoolsize", &pmc_mtxpool_size); 268 SYSCTL_INT(_kern_hwpmc, OID_AUTO, mtxpoolsize, CTLFLAG_TUN|CTLFLAG_RD, 269 &pmc_mtxpool_size, 0, "size of spin mutex pool"); 270 271 272 /* 273 * security.bsd.unprivileged_syspmcs -- allow non-root processes to 274 * allocate system-wide PMCs. 275 * 276 * Allowing unprivileged processes to allocate system PMCs is convenient 277 * if system-wide measurements need to be taken concurrently with other 278 * per-process measurements. This feature is turned off by default. 279 */ 280 281 static int pmc_unprivileged_syspmcs = 0; 282 TUNABLE_INT("security.bsd.unprivileged_syspmcs", &pmc_unprivileged_syspmcs); 283 SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_syspmcs, CTLFLAG_RW, 284 &pmc_unprivileged_syspmcs, 0, 285 "allow unprivileged process to allocate system PMCs"); 286 287 /* 288 * Hash function. Discard the lower 2 bits of the pointer since 289 * these are always zero for our uses. The hash multiplier is 290 * round((2^LONG_BIT) * ((sqrt(5)-1)/2)). 291 */ 292 293 #if LONG_BIT == 64 294 #define _PMC_HM 11400714819323198486u 295 #elif LONG_BIT == 32 296 #define _PMC_HM 2654435769u 297 #else 298 #error Must know the size of 'long' to compile 299 #endif 300 301 #define PMC_HASH_PTR(P,M) ((((unsigned long) (P) >> 2) * _PMC_HM) & (M)) 302 303 /* 304 * Syscall structures 305 */ 306 307 /* The `sysent' for the new syscall */ 308 static struct sysent pmc_sysent = { 309 2, /* sy_narg */ 310 pmc_syscall_handler /* sy_call */ 311 }; 312 313 static struct syscall_module_data pmc_syscall_mod = { 314 load, 315 NULL, 316 &pmc_syscall_num, 317 &pmc_sysent, 318 { 0, NULL } 319 }; 320 321 static moduledata_t pmc_mod = { 322 PMC_MODULE_NAME, 323 syscall_module_handler, 324 &pmc_syscall_mod 325 }; 326 327 DECLARE_MODULE(pmc, pmc_mod, SI_SUB_SMP, SI_ORDER_ANY); 328 MODULE_VERSION(pmc, PMC_VERSION); 329 330 #ifdef DEBUG 331 enum pmc_dbgparse_state { 332 PMCDS_WS, /* in whitespace */ 333 PMCDS_MAJOR, /* seen a major keyword */ 334 PMCDS_MINOR 335 }; 336 337 static int 338 pmc_debugflags_parse(char *newstr, char *fence) 339 { 340 char c, *p, *q; 341 struct pmc_debugflags *tmpflags; 342 int error, found, *newbits, tmp; 343 size_t kwlen; 344 345 tmpflags = malloc(sizeof(*tmpflags), M_PMC, M_WAITOK|M_ZERO); 346 347 p = newstr; 348 error = 0; 349 350 for (; p < fence && (c = *p); p++) { 351 352 /* skip white space */ 353 if (c == ' ' || c == '\t') 354 continue; 355 356 /* look for a keyword followed by "=" */ 357 for (q = p; p < fence && (c = *p) && c != '='; p++) 358 ; 359 if (c != '=') { 360 error = EINVAL; 361 goto done; 362 } 363 364 kwlen = p - q; 365 newbits = NULL; 366 367 /* lookup flag group name */ 368 #define DBG_SET_FLAG_MAJ(S,F) \ 369 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \ 370 newbits = &tmpflags->pdb_ ## F; 371 372 DBG_SET_FLAG_MAJ("cpu", CPU); 373 DBG_SET_FLAG_MAJ("csw", CSW); 374 DBG_SET_FLAG_MAJ("logging", LOG); 375 DBG_SET_FLAG_MAJ("module", MOD); 376 DBG_SET_FLAG_MAJ("md", MDP); 377 DBG_SET_FLAG_MAJ("owner", OWN); 378 DBG_SET_FLAG_MAJ("pmc", PMC); 379 DBG_SET_FLAG_MAJ("process", PRC); 380 DBG_SET_FLAG_MAJ("sampling", SAM); 381 382 if (newbits == NULL) { 383 error = EINVAL; 384 goto done; 385 } 386 387 p++; /* skip the '=' */ 388 389 /* Now parse the individual flags */ 390 tmp = 0; 391 newflag: 392 for (q = p; p < fence && (c = *p); p++) 393 if (c == ' ' || c == '\t' || c == ',') 394 break; 395 396 /* p == fence or c == ws or c == "," or c == 0 */ 397 398 if ((kwlen = p - q) == 0) { 399 *newbits = tmp; 400 continue; 401 } 402 403 found = 0; 404 #define DBG_SET_FLAG_MIN(S,F) \ 405 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \ 406 tmp |= found = (1 << PMC_DEBUG_MIN_ ## F) 407 408 /* a '*' denotes all possible flags in the group */ 409 if (kwlen == 1 && *q == '*') 410 tmp = found = ~0; 411 /* look for individual flag names */ 412 DBG_SET_FLAG_MIN("allocaterow", ALR); 413 DBG_SET_FLAG_MIN("allocate", ALL); 414 DBG_SET_FLAG_MIN("attach", ATT); 415 DBG_SET_FLAG_MIN("bind", BND); 416 DBG_SET_FLAG_MIN("config", CFG); 417 DBG_SET_FLAG_MIN("exec", EXC); 418 DBG_SET_FLAG_MIN("exit", EXT); 419 DBG_SET_FLAG_MIN("find", FND); 420 DBG_SET_FLAG_MIN("flush", FLS); 421 DBG_SET_FLAG_MIN("fork", FRK); 422 DBG_SET_FLAG_MIN("getbuf", GTB); 423 DBG_SET_FLAG_MIN("hook", PMH); 424 DBG_SET_FLAG_MIN("init", INI); 425 DBG_SET_FLAG_MIN("intr", INT); 426 DBG_SET_FLAG_MIN("linktarget", TLK); 427 DBG_SET_FLAG_MIN("mayberemove", OMR); 428 DBG_SET_FLAG_MIN("ops", OPS); 429 DBG_SET_FLAG_MIN("read", REA); 430 DBG_SET_FLAG_MIN("register", REG); 431 DBG_SET_FLAG_MIN("release", REL); 432 DBG_SET_FLAG_MIN("remove", ORM); 433 DBG_SET_FLAG_MIN("sample", SAM); 434 DBG_SET_FLAG_MIN("scheduleio", SIO); 435 DBG_SET_FLAG_MIN("select", SEL); 436 DBG_SET_FLAG_MIN("signal", SIG); 437 DBG_SET_FLAG_MIN("swi", SWI); 438 DBG_SET_FLAG_MIN("swo", SWO); 439 DBG_SET_FLAG_MIN("start", STA); 440 DBG_SET_FLAG_MIN("stop", STO); 441 DBG_SET_FLAG_MIN("syscall", PMS); 442 DBG_SET_FLAG_MIN("unlinktarget", TUL); 443 DBG_SET_FLAG_MIN("write", WRI); 444 if (found == 0) { 445 /* unrecognized flag name */ 446 error = EINVAL; 447 goto done; 448 } 449 450 if (c == 0 || c == ' ' || c == '\t') { /* end of flag group */ 451 *newbits = tmp; 452 continue; 453 } 454 455 p++; 456 goto newflag; 457 } 458 459 /* save the new flag set */ 460 bcopy(tmpflags, &pmc_debugflags, sizeof(pmc_debugflags)); 461 462 done: 463 free(tmpflags, M_PMC); 464 return error; 465 } 466 467 static int 468 pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS) 469 { 470 char *fence, *newstr; 471 int error; 472 unsigned int n; 473 474 (void) arg1; (void) arg2; /* unused parameters */ 475 476 n = sizeof(pmc_debugstr); 477 newstr = malloc(n, M_PMC, M_WAITOK|M_ZERO); 478 (void) strlcpy(newstr, pmc_debugstr, n); 479 480 error = sysctl_handle_string(oidp, newstr, n, req); 481 482 /* if there is a new string, parse and copy it */ 483 if (error == 0 && req->newptr != NULL) { 484 fence = newstr + (n < req->newlen ? n : req->newlen + 1); 485 if ((error = pmc_debugflags_parse(newstr, fence)) == 0) 486 (void) strlcpy(pmc_debugstr, newstr, 487 sizeof(pmc_debugstr)); 488 } 489 490 free(newstr, M_PMC); 491 492 return error; 493 } 494 #endif 495 496 /* 497 * Map a row index to a classdep structure and return the adjusted row 498 * index for the PMC class index. 499 */ 500 static struct pmc_classdep * 501 pmc_ri_to_classdep(struct pmc_mdep *md, int ri, int *adjri) 502 { 503 struct pmc_classdep *pcd; 504 505 (void) md; 506 507 KASSERT(ri >= 0 && ri < md->pmd_npmc, 508 ("[pmc,%d] illegal row-index %d", __LINE__, ri)); 509 510 pcd = pmc_rowindex_to_classdep[ri]; 511 512 KASSERT(pcd != NULL, 513 ("[pmc,%d] ri %d null pcd", __LINE__, ri)); 514 515 *adjri = ri - pcd->pcd_ri; 516 517 KASSERT(*adjri >= 0 && *adjri < pcd->pcd_num, 518 ("[pmc,%d] adjusted row-index %d", __LINE__, *adjri)); 519 520 return (pcd); 521 } 522 523 /* 524 * Concurrency Control 525 * 526 * The driver manages the following data structures: 527 * 528 * - target process descriptors, one per target process 529 * - owner process descriptors (and attached lists), one per owner process 530 * - lookup hash tables for owner and target processes 531 * - PMC descriptors (and attached lists) 532 * - per-cpu hardware state 533 * - the 'hook' variable through which the kernel calls into 534 * this module 535 * - the machine hardware state (managed by the MD layer) 536 * 537 * These data structures are accessed from: 538 * 539 * - thread context-switch code 540 * - interrupt handlers (possibly on multiple cpus) 541 * - kernel threads on multiple cpus running on behalf of user 542 * processes doing system calls 543 * - this driver's private kernel threads 544 * 545 * = Locks and Locking strategy = 546 * 547 * The driver uses four locking strategies for its operation: 548 * 549 * - The global SX lock "pmc_sx" is used to protect internal 550 * data structures. 551 * 552 * Calls into the module by syscall() start with this lock being 553 * held in exclusive mode. Depending on the requested operation, 554 * the lock may be downgraded to 'shared' mode to allow more 555 * concurrent readers into the module. Calls into the module from 556 * other parts of the kernel acquire the lock in shared mode. 557 * 558 * This SX lock is held in exclusive mode for any operations that 559 * modify the linkages between the driver's internal data structures. 560 * 561 * The 'pmc_hook' function pointer is also protected by this lock. 562 * It is only examined with the sx lock held in exclusive mode. The 563 * kernel module is allowed to be unloaded only with the sx lock held 564 * in exclusive mode. In normal syscall handling, after acquiring the 565 * pmc_sx lock we first check that 'pmc_hook' is non-null before 566 * proceeding. This prevents races between the thread unloading the module 567 * and other threads seeking to use the module. 568 * 569 * - Lookups of target process structures and owner process structures 570 * cannot use the global "pmc_sx" SX lock because these lookups need 571 * to happen during context switches and in other critical sections 572 * where sleeping is not allowed. We protect these lookup tables 573 * with their own private spin-mutexes, "pmc_processhash_mtx" and 574 * "pmc_ownerhash_mtx". 575 * 576 * - Interrupt handlers work in a lock free manner. At interrupt 577 * time, handlers look at the PMC pointer (phw->phw_pmc) configured 578 * when the PMC was started. If this pointer is NULL, the interrupt 579 * is ignored after updating driver statistics. We ensure that this 580 * pointer is set (using an atomic operation if necessary) before the 581 * PMC hardware is started. Conversely, this pointer is unset atomically 582 * only after the PMC hardware is stopped. 583 * 584 * We ensure that everything needed for the operation of an 585 * interrupt handler is available without it needing to acquire any 586 * locks. We also ensure that a PMC's software state is destroyed only 587 * after the PMC is taken off hardware (on all CPUs). 588 * 589 * - Context-switch handling with process-private PMCs needs more 590 * care. 591 * 592 * A given process may be the target of multiple PMCs. For example, 593 * PMCATTACH and PMCDETACH may be requested by a process on one CPU 594 * while the target process is running on another. A PMC could also 595 * be getting released because its owner is exiting. We tackle 596 * these situations in the following manner: 597 * 598 * - each target process structure 'pmc_process' has an array 599 * of 'struct pmc *' pointers, one for each hardware PMC. 600 * 601 * - At context switch IN time, each "target" PMC in RUNNING state 602 * gets started on hardware and a pointer to each PMC is copied into 603 * the per-cpu phw array. The 'runcount' for the PMC is 604 * incremented. 605 * 606 * - At context switch OUT time, all process-virtual PMCs are stopped 607 * on hardware. The saved value is added to the PMCs value field 608 * only if the PMC is in a non-deleted state (the PMCs state could 609 * have changed during the current time slice). 610 * 611 * Note that since in-between a switch IN on a processor and a switch 612 * OUT, the PMC could have been released on another CPU. Therefore 613 * context switch OUT always looks at the hardware state to turn 614 * OFF PMCs and will update a PMC's saved value only if reachable 615 * from the target process record. 616 * 617 * - OP PMCRELEASE could be called on a PMC at any time (the PMC could 618 * be attached to many processes at the time of the call and could 619 * be active on multiple CPUs). 620 * 621 * We prevent further scheduling of the PMC by marking it as in 622 * state 'DELETED'. If the runcount of the PMC is non-zero then 623 * this PMC is currently running on a CPU somewhere. The thread 624 * doing the PMCRELEASE operation waits by repeatedly doing a 625 * pause() till the runcount comes to zero. 626 * 627 * The contents of a PMC descriptor (struct pmc) are protected using 628 * a spin-mutex. In order to save space, we use a mutex pool. 629 * 630 * In terms of lock types used by witness(4), we use: 631 * - Type "pmc-sx", used by the global SX lock. 632 * - Type "pmc-sleep", for sleep mutexes used by logger threads. 633 * - Type "pmc-per-proc", for protecting PMC owner descriptors. 634 * - Type "pmc-leaf", used for all other spin mutexes. 635 */ 636 637 /* 638 * save the cpu binding of the current kthread 639 */ 640 641 static void 642 pmc_save_cpu_binding(struct pmc_binding *pb) 643 { 644 PMCDBG(CPU,BND,2, "%s", "save-cpu"); 645 thread_lock(curthread); 646 pb->pb_bound = sched_is_bound(curthread); 647 pb->pb_cpu = curthread->td_oncpu; 648 thread_unlock(curthread); 649 PMCDBG(CPU,BND,2, "save-cpu cpu=%d", pb->pb_cpu); 650 } 651 652 /* 653 * restore the cpu binding of the current thread 654 */ 655 656 static void 657 pmc_restore_cpu_binding(struct pmc_binding *pb) 658 { 659 PMCDBG(CPU,BND,2, "restore-cpu curcpu=%d restore=%d", 660 curthread->td_oncpu, pb->pb_cpu); 661 thread_lock(curthread); 662 if (pb->pb_bound) 663 sched_bind(curthread, pb->pb_cpu); 664 else 665 sched_unbind(curthread); 666 thread_unlock(curthread); 667 PMCDBG(CPU,BND,2, "%s", "restore-cpu done"); 668 } 669 670 /* 671 * move execution over the specified cpu and bind it there. 672 */ 673 674 static void 675 pmc_select_cpu(int cpu) 676 { 677 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 678 ("[pmc,%d] bad cpu number %d", __LINE__, cpu)); 679 680 /* Never move to an inactive CPU. */ 681 KASSERT(pmc_cpu_is_active(cpu), ("[pmc,%d] selecting inactive " 682 "CPU %d", __LINE__, cpu)); 683 684 PMCDBG(CPU,SEL,2, "select-cpu cpu=%d", cpu); 685 thread_lock(curthread); 686 sched_bind(curthread, cpu); 687 thread_unlock(curthread); 688 689 KASSERT(curthread->td_oncpu == cpu, 690 ("[pmc,%d] CPU not bound [cpu=%d, curr=%d]", __LINE__, 691 cpu, curthread->td_oncpu)); 692 693 PMCDBG(CPU,SEL,2, "select-cpu cpu=%d ok", cpu); 694 } 695 696 /* 697 * Force a context switch. 698 * 699 * We do this by pause'ing for 1 tick -- invoking mi_switch() is not 700 * guaranteed to force a context switch. 701 */ 702 703 static void 704 pmc_force_context_switch(void) 705 { 706 707 pause("pmcctx", 1); 708 } 709 710 /* 711 * Get the file name for an executable. This is a simple wrapper 712 * around vn_fullpath(9). 713 */ 714 715 static void 716 pmc_getfilename(struct vnode *v, char **fullpath, char **freepath) 717 { 718 719 *fullpath = "unknown"; 720 *freepath = NULL; 721 vn_fullpath(curthread, v, fullpath, freepath); 722 } 723 724 /* 725 * remove an process owning PMCs 726 */ 727 728 void 729 pmc_remove_owner(struct pmc_owner *po) 730 { 731 struct pmc *pm, *tmp; 732 733 sx_assert(&pmc_sx, SX_XLOCKED); 734 735 PMCDBG(OWN,ORM,1, "remove-owner po=%p", po); 736 737 /* Remove descriptor from the owner hash table */ 738 LIST_REMOVE(po, po_next); 739 740 /* release all owned PMC descriptors */ 741 LIST_FOREACH_SAFE(pm, &po->po_pmcs, pm_next, tmp) { 742 PMCDBG(OWN,ORM,2, "pmc=%p", pm); 743 KASSERT(pm->pm_owner == po, 744 ("[pmc,%d] owner %p != po %p", __LINE__, pm->pm_owner, po)); 745 746 pmc_release_pmc_descriptor(pm); /* will unlink from the list */ 747 } 748 749 KASSERT(po->po_sscount == 0, 750 ("[pmc,%d] SS count not zero", __LINE__)); 751 KASSERT(LIST_EMPTY(&po->po_pmcs), 752 ("[pmc,%d] PMC list not empty", __LINE__)); 753 754 /* de-configure the log file if present */ 755 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 756 pmclog_deconfigure_log(po); 757 } 758 759 /* 760 * remove an owner process record if all conditions are met. 761 */ 762 763 static void 764 pmc_maybe_remove_owner(struct pmc_owner *po) 765 { 766 767 PMCDBG(OWN,OMR,1, "maybe-remove-owner po=%p", po); 768 769 /* 770 * Remove owner record if 771 * - this process does not own any PMCs 772 * - this process has not allocated a system-wide sampling buffer 773 */ 774 775 if (LIST_EMPTY(&po->po_pmcs) && 776 ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0)) { 777 pmc_remove_owner(po); 778 pmc_destroy_owner_descriptor(po); 779 } 780 } 781 782 /* 783 * Add an association between a target process and a PMC. 784 */ 785 786 static void 787 pmc_link_target_process(struct pmc *pm, struct pmc_process *pp) 788 { 789 int ri; 790 struct pmc_target *pt; 791 792 sx_assert(&pmc_sx, SX_XLOCKED); 793 794 KASSERT(pm != NULL && pp != NULL, 795 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 796 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 797 ("[pmc,%d] Attaching a non-process-virtual pmc=%p to pid=%d", 798 __LINE__, pm, pp->pp_proc->p_pid)); 799 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= ((int) md->pmd_npmc - 1), 800 ("[pmc,%d] Illegal reference count %d for process record %p", 801 __LINE__, pp->pp_refcnt, (void *) pp)); 802 803 ri = PMC_TO_ROWINDEX(pm); 804 805 PMCDBG(PRC,TLK,1, "link-target pmc=%p ri=%d pmc-process=%p", 806 pm, ri, pp); 807 808 #ifdef DEBUG 809 LIST_FOREACH(pt, &pm->pm_targets, pt_next) 810 if (pt->pt_process == pp) 811 KASSERT(0, ("[pmc,%d] pp %p already in pmc %p targets", 812 __LINE__, pp, pm)); 813 #endif 814 815 pt = malloc(sizeof(struct pmc_target), M_PMC, M_WAITOK|M_ZERO); 816 pt->pt_process = pp; 817 818 LIST_INSERT_HEAD(&pm->pm_targets, pt, pt_next); 819 820 atomic_store_rel_ptr((uintptr_t *)&pp->pp_pmcs[ri].pp_pmc, 821 (uintptr_t)pm); 822 823 if (pm->pm_owner->po_owner == pp->pp_proc) 824 pm->pm_flags |= PMC_F_ATTACHED_TO_OWNER; 825 826 /* 827 * Initialize the per-process values at this row index. 828 */ 829 pp->pp_pmcs[ri].pp_pmcval = PMC_TO_MODE(pm) == PMC_MODE_TS ? 830 pm->pm_sc.pm_reloadcount : 0; 831 832 pp->pp_refcnt++; 833 834 } 835 836 /* 837 * Removes the association between a target process and a PMC. 838 */ 839 840 static void 841 pmc_unlink_target_process(struct pmc *pm, struct pmc_process *pp) 842 { 843 int ri; 844 struct proc *p; 845 struct pmc_target *ptgt; 846 847 sx_assert(&pmc_sx, SX_XLOCKED); 848 849 KASSERT(pm != NULL && pp != NULL, 850 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 851 852 KASSERT(pp->pp_refcnt >= 1 && pp->pp_refcnt <= (int) md->pmd_npmc, 853 ("[pmc,%d] Illegal ref count %d on process record %p", 854 __LINE__, pp->pp_refcnt, (void *) pp)); 855 856 ri = PMC_TO_ROWINDEX(pm); 857 858 PMCDBG(PRC,TUL,1, "unlink-target pmc=%p ri=%d pmc-process=%p", 859 pm, ri, pp); 860 861 KASSERT(pp->pp_pmcs[ri].pp_pmc == pm, 862 ("[pmc,%d] PMC ri %d mismatch pmc %p pp->[ri] %p", __LINE__, 863 ri, pm, pp->pp_pmcs[ri].pp_pmc)); 864 865 pp->pp_pmcs[ri].pp_pmc = NULL; 866 pp->pp_pmcs[ri].pp_pmcval = (pmc_value_t) 0; 867 868 /* Remove owner-specific flags */ 869 if (pm->pm_owner->po_owner == pp->pp_proc) { 870 pp->pp_flags &= ~PMC_PP_ENABLE_MSR_ACCESS; 871 pm->pm_flags &= ~PMC_F_ATTACHED_TO_OWNER; 872 } 873 874 pp->pp_refcnt--; 875 876 /* Remove the target process from the PMC structure */ 877 LIST_FOREACH(ptgt, &pm->pm_targets, pt_next) 878 if (ptgt->pt_process == pp) 879 break; 880 881 KASSERT(ptgt != NULL, ("[pmc,%d] process %p (pp: %p) not found " 882 "in pmc %p", __LINE__, pp->pp_proc, pp, pm)); 883 884 LIST_REMOVE(ptgt, pt_next); 885 free(ptgt, M_PMC); 886 887 /* if the PMC now lacks targets, send the owner a SIGIO */ 888 if (LIST_EMPTY(&pm->pm_targets)) { 889 p = pm->pm_owner->po_owner; 890 PROC_LOCK(p); 891 psignal(p, SIGIO); 892 PROC_UNLOCK(p); 893 894 PMCDBG(PRC,SIG,2, "signalling proc=%p signal=%d", p, 895 SIGIO); 896 } 897 } 898 899 /* 900 * Check if PMC 'pm' may be attached to target process 't'. 901 */ 902 903 static int 904 pmc_can_attach(struct pmc *pm, struct proc *t) 905 { 906 struct proc *o; /* pmc owner */ 907 struct ucred *oc, *tc; /* owner, target credentials */ 908 int decline_attach, i; 909 910 /* 911 * A PMC's owner can always attach that PMC to itself. 912 */ 913 914 if ((o = pm->pm_owner->po_owner) == t) 915 return 0; 916 917 PROC_LOCK(o); 918 oc = o->p_ucred; 919 crhold(oc); 920 PROC_UNLOCK(o); 921 922 PROC_LOCK(t); 923 tc = t->p_ucred; 924 crhold(tc); 925 PROC_UNLOCK(t); 926 927 /* 928 * The effective uid of the PMC owner should match at least one 929 * of the {effective,real,saved} uids of the target process. 930 */ 931 932 decline_attach = oc->cr_uid != tc->cr_uid && 933 oc->cr_uid != tc->cr_svuid && 934 oc->cr_uid != tc->cr_ruid; 935 936 /* 937 * Every one of the target's group ids, must be in the owner's 938 * group list. 939 */ 940 for (i = 0; !decline_attach && i < tc->cr_ngroups; i++) 941 decline_attach = !groupmember(tc->cr_groups[i], oc); 942 943 /* check the read and saved gids too */ 944 if (decline_attach == 0) 945 decline_attach = !groupmember(tc->cr_rgid, oc) || 946 !groupmember(tc->cr_svgid, oc); 947 948 crfree(tc); 949 crfree(oc); 950 951 return !decline_attach; 952 } 953 954 /* 955 * Attach a process to a PMC. 956 */ 957 958 static int 959 pmc_attach_one_process(struct proc *p, struct pmc *pm) 960 { 961 int ri; 962 char *fullpath, *freepath; 963 struct pmc_process *pp; 964 965 sx_assert(&pmc_sx, SX_XLOCKED); 966 967 PMCDBG(PRC,ATT,2, "attach-one pm=%p ri=%d proc=%p (%d, %s)", pm, 968 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 969 970 /* 971 * Locate the process descriptor corresponding to process 'p', 972 * allocating space as needed. 973 * 974 * Verify that rowindex 'pm_rowindex' is free in the process 975 * descriptor. 976 * 977 * If not, allocate space for a descriptor and link the 978 * process descriptor and PMC. 979 */ 980 ri = PMC_TO_ROWINDEX(pm); 981 982 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_ALLOCATE)) == NULL) 983 return ENOMEM; 984 985 if (pp->pp_pmcs[ri].pp_pmc == pm) /* already present at slot [ri] */ 986 return EEXIST; 987 988 if (pp->pp_pmcs[ri].pp_pmc != NULL) 989 return EBUSY; 990 991 pmc_link_target_process(pm, pp); 992 993 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) && 994 (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) == 0) 995 pm->pm_flags |= PMC_F_NEEDS_LOGFILE; 996 997 pm->pm_flags |= PMC_F_ATTACH_DONE; /* mark as attached */ 998 999 /* issue an attach event to a configured log file */ 1000 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) { 1001 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 1002 if (p->p_flag & P_KTHREAD) { 1003 fullpath = kernelname; 1004 freepath = NULL; 1005 } else 1006 pmclog_process_pmcattach(pm, p->p_pid, fullpath); 1007 if (freepath) 1008 free(freepath, M_TEMP); 1009 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1010 pmc_log_process_mappings(pm->pm_owner, p); 1011 } 1012 /* mark process as using HWPMCs */ 1013 PROC_LOCK(p); 1014 p->p_flag |= P_HWPMC; 1015 PROC_UNLOCK(p); 1016 1017 return 0; 1018 } 1019 1020 /* 1021 * Attach a process and optionally its children 1022 */ 1023 1024 static int 1025 pmc_attach_process(struct proc *p, struct pmc *pm) 1026 { 1027 int error; 1028 struct proc *top; 1029 1030 sx_assert(&pmc_sx, SX_XLOCKED); 1031 1032 PMCDBG(PRC,ATT,1, "attach pm=%p ri=%d proc=%p (%d, %s)", pm, 1033 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1034 1035 1036 /* 1037 * If this PMC successfully allowed a GETMSR operation 1038 * in the past, disallow further ATTACHes. 1039 */ 1040 1041 if ((pm->pm_flags & PMC_PP_ENABLE_MSR_ACCESS) != 0) 1042 return EPERM; 1043 1044 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 1045 return pmc_attach_one_process(p, pm); 1046 1047 /* 1048 * Traverse all child processes, attaching them to 1049 * this PMC. 1050 */ 1051 1052 sx_slock(&proctree_lock); 1053 1054 top = p; 1055 1056 for (;;) { 1057 if ((error = pmc_attach_one_process(p, pm)) != 0) 1058 break; 1059 if (!LIST_EMPTY(&p->p_children)) 1060 p = LIST_FIRST(&p->p_children); 1061 else for (;;) { 1062 if (p == top) 1063 goto done; 1064 if (LIST_NEXT(p, p_sibling)) { 1065 p = LIST_NEXT(p, p_sibling); 1066 break; 1067 } 1068 p = p->p_pptr; 1069 } 1070 } 1071 1072 if (error) 1073 (void) pmc_detach_process(top, pm); 1074 1075 done: 1076 sx_sunlock(&proctree_lock); 1077 return error; 1078 } 1079 1080 /* 1081 * Detach a process from a PMC. If there are no other PMCs tracking 1082 * this process, remove the process structure from its hash table. If 1083 * 'flags' contains PMC_FLAG_REMOVE, then free the process structure. 1084 */ 1085 1086 static int 1087 pmc_detach_one_process(struct proc *p, struct pmc *pm, int flags) 1088 { 1089 int ri; 1090 struct pmc_process *pp; 1091 1092 sx_assert(&pmc_sx, SX_XLOCKED); 1093 1094 KASSERT(pm != NULL, 1095 ("[pmc,%d] null pm pointer", __LINE__)); 1096 1097 ri = PMC_TO_ROWINDEX(pm); 1098 1099 PMCDBG(PRC,ATT,2, "detach-one pm=%p ri=%d proc=%p (%d, %s) flags=0x%x", 1100 pm, ri, p, p->p_pid, p->p_comm, flags); 1101 1102 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) 1103 return ESRCH; 1104 1105 if (pp->pp_pmcs[ri].pp_pmc != pm) 1106 return EINVAL; 1107 1108 pmc_unlink_target_process(pm, pp); 1109 1110 /* Issue a detach entry if a log file is configured */ 1111 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) 1112 pmclog_process_pmcdetach(pm, p->p_pid); 1113 1114 /* 1115 * If there are no PMCs targetting this process, we remove its 1116 * descriptor from the target hash table and unset the P_HWPMC 1117 * flag in the struct proc. 1118 */ 1119 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= (int) md->pmd_npmc, 1120 ("[pmc,%d] Illegal refcnt %d for process struct %p", 1121 __LINE__, pp->pp_refcnt, pp)); 1122 1123 if (pp->pp_refcnt != 0) /* still a target of some PMC */ 1124 return 0; 1125 1126 pmc_remove_process_descriptor(pp); 1127 1128 if (flags & PMC_FLAG_REMOVE) 1129 free(pp, M_PMC); 1130 1131 PROC_LOCK(p); 1132 p->p_flag &= ~P_HWPMC; 1133 PROC_UNLOCK(p); 1134 1135 return 0; 1136 } 1137 1138 /* 1139 * Detach a process and optionally its descendants from a PMC. 1140 */ 1141 1142 static int 1143 pmc_detach_process(struct proc *p, struct pmc *pm) 1144 { 1145 struct proc *top; 1146 1147 sx_assert(&pmc_sx, SX_XLOCKED); 1148 1149 PMCDBG(PRC,ATT,1, "detach pm=%p ri=%d proc=%p (%d, %s)", pm, 1150 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1151 1152 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 1153 return pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); 1154 1155 /* 1156 * Traverse all children, detaching them from this PMC. We 1157 * ignore errors since we could be detaching a PMC from a 1158 * partially attached proc tree. 1159 */ 1160 1161 sx_slock(&proctree_lock); 1162 1163 top = p; 1164 1165 for (;;) { 1166 (void) pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); 1167 1168 if (!LIST_EMPTY(&p->p_children)) 1169 p = LIST_FIRST(&p->p_children); 1170 else for (;;) { 1171 if (p == top) 1172 goto done; 1173 if (LIST_NEXT(p, p_sibling)) { 1174 p = LIST_NEXT(p, p_sibling); 1175 break; 1176 } 1177 p = p->p_pptr; 1178 } 1179 } 1180 1181 done: 1182 sx_sunlock(&proctree_lock); 1183 1184 if (LIST_EMPTY(&pm->pm_targets)) 1185 pm->pm_flags &= ~PMC_F_ATTACH_DONE; 1186 1187 return 0; 1188 } 1189 1190 1191 /* 1192 * Thread context switch IN 1193 */ 1194 1195 static void 1196 pmc_process_csw_in(struct thread *td) 1197 { 1198 int cpu; 1199 unsigned int adjri, ri; 1200 struct pmc *pm; 1201 struct proc *p; 1202 struct pmc_cpu *pc; 1203 struct pmc_hw *phw; 1204 pmc_value_t newvalue; 1205 struct pmc_process *pp; 1206 struct pmc_classdep *pcd; 1207 1208 p = td->td_proc; 1209 1210 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE)) == NULL) 1211 return; 1212 1213 KASSERT(pp->pp_proc == td->td_proc, 1214 ("[pmc,%d] not my thread state", __LINE__)); 1215 1216 critical_enter(); /* no preemption from this point */ 1217 1218 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1219 1220 PMCDBG(CSW,SWI,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1221 p->p_pid, p->p_comm, pp); 1222 1223 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 1224 ("[pmc,%d] wierd CPU id %d", __LINE__, cpu)); 1225 1226 pc = pmc_pcpu[cpu]; 1227 1228 for (ri = 0; ri < md->pmd_npmc; ri++) { 1229 1230 if ((pm = pp->pp_pmcs[ri].pp_pmc) == NULL) 1231 continue; 1232 1233 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 1234 ("[pmc,%d] Target PMC in non-virtual mode (%d)", 1235 __LINE__, PMC_TO_MODE(pm))); 1236 1237 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1238 ("[pmc,%d] Row index mismatch pmc %d != ri %d", 1239 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1240 1241 /* 1242 * Only PMCs that are marked as 'RUNNING' need 1243 * be placed on hardware. 1244 */ 1245 1246 if (pm->pm_state != PMC_STATE_RUNNING) 1247 continue; 1248 1249 /* increment PMC runcount */ 1250 atomic_add_rel_32(&pm->pm_runcount, 1); 1251 1252 /* configure the HWPMC we are going to use. */ 1253 pcd = pmc_ri_to_classdep(md, ri, &adjri); 1254 pcd->pcd_config_pmc(cpu, adjri, pm); 1255 1256 phw = pc->pc_hwpmcs[ri]; 1257 1258 KASSERT(phw != NULL, 1259 ("[pmc,%d] null hw pointer", __LINE__)); 1260 1261 KASSERT(phw->phw_pmc == pm, 1262 ("[pmc,%d] hw->pmc %p != pmc %p", __LINE__, 1263 phw->phw_pmc, pm)); 1264 1265 /* 1266 * Write out saved value and start the PMC. 1267 * 1268 * Sampling PMCs use a per-process value, while 1269 * counting mode PMCs use a per-pmc value that is 1270 * inherited across descendants. 1271 */ 1272 if (PMC_TO_MODE(pm) == PMC_MODE_TS) { 1273 mtx_pool_lock_spin(pmc_mtxpool, pm); 1274 newvalue = PMC_PCPU_SAVED(cpu,ri) = 1275 pp->pp_pmcs[ri].pp_pmcval; 1276 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1277 } else { 1278 KASSERT(PMC_TO_MODE(pm) == PMC_MODE_TC, 1279 ("[pmc,%d] illegal mode=%d", __LINE__, 1280 PMC_TO_MODE(pm))); 1281 mtx_pool_lock_spin(pmc_mtxpool, pm); 1282 newvalue = PMC_PCPU_SAVED(cpu, ri) = 1283 pm->pm_gv.pm_savedvalue; 1284 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1285 } 1286 1287 PMCDBG(CSW,SWI,1,"cpu=%d ri=%d new=%jd", cpu, ri, newvalue); 1288 1289 pcd->pcd_write_pmc(cpu, adjri, newvalue); 1290 pcd->pcd_start_pmc(cpu, adjri); 1291 } 1292 1293 /* 1294 * perform any other architecture/cpu dependent thread 1295 * switch-in actions. 1296 */ 1297 1298 (void) (*md->pmd_switch_in)(pc, pp); 1299 1300 critical_exit(); 1301 1302 } 1303 1304 /* 1305 * Thread context switch OUT. 1306 */ 1307 1308 static void 1309 pmc_process_csw_out(struct thread *td) 1310 { 1311 int cpu; 1312 int64_t tmp; 1313 struct pmc *pm; 1314 struct proc *p; 1315 enum pmc_mode mode; 1316 struct pmc_cpu *pc; 1317 pmc_value_t newvalue; 1318 unsigned int adjri, ri; 1319 struct pmc_process *pp; 1320 struct pmc_classdep *pcd; 1321 1322 1323 /* 1324 * Locate our process descriptor; this may be NULL if 1325 * this process is exiting and we have already removed 1326 * the process from the target process table. 1327 * 1328 * Note that due to kernel preemption, multiple 1329 * context switches may happen while the process is 1330 * exiting. 1331 * 1332 * Note also that if the target process cannot be 1333 * found we still need to deconfigure any PMCs that 1334 * are currently running on hardware. 1335 */ 1336 1337 p = td->td_proc; 1338 pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE); 1339 1340 /* 1341 * save PMCs 1342 */ 1343 1344 critical_enter(); 1345 1346 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1347 1348 PMCDBG(CSW,SWO,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1349 p->p_pid, p->p_comm, pp); 1350 1351 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 1352 ("[pmc,%d wierd CPU id %d", __LINE__, cpu)); 1353 1354 pc = pmc_pcpu[cpu]; 1355 1356 /* 1357 * When a PMC gets unlinked from a target PMC, it will 1358 * be removed from the target's pp_pmc[] array. 1359 * 1360 * However, on a MP system, the target could have been 1361 * executing on another CPU at the time of the unlink. 1362 * So, at context switch OUT time, we need to look at 1363 * the hardware to determine if a PMC is scheduled on 1364 * it. 1365 */ 1366 1367 for (ri = 0; ri < md->pmd_npmc; ri++) { 1368 1369 pcd = pmc_ri_to_classdep(md, ri, &adjri); 1370 pm = NULL; 1371 (void) (*pcd->pcd_get_config)(cpu, adjri, &pm); 1372 1373 if (pm == NULL) /* nothing at this row index */ 1374 continue; 1375 1376 mode = PMC_TO_MODE(pm); 1377 if (!PMC_IS_VIRTUAL_MODE(mode)) 1378 continue; /* not a process virtual PMC */ 1379 1380 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1381 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 1382 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1383 1384 /* Stop hardware if not already stopped */ 1385 if (pm->pm_stalled == 0) 1386 pcd->pcd_stop_pmc(cpu, adjri); 1387 1388 /* reduce this PMC's runcount */ 1389 atomic_subtract_rel_32(&pm->pm_runcount, 1); 1390 1391 /* 1392 * If this PMC is associated with this process, 1393 * save the reading. 1394 */ 1395 1396 if (pp != NULL && pp->pp_pmcs[ri].pp_pmc != NULL) { 1397 1398 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 1399 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", __LINE__, 1400 pm, ri, pp->pp_pmcs[ri].pp_pmc)); 1401 1402 KASSERT(pp->pp_refcnt > 0, 1403 ("[pmc,%d] pp refcnt = %d", __LINE__, 1404 pp->pp_refcnt)); 1405 1406 pcd->pcd_read_pmc(cpu, adjri, &newvalue); 1407 1408 tmp = newvalue - PMC_PCPU_SAVED(cpu,ri); 1409 1410 PMCDBG(CSW,SWO,1,"cpu=%d ri=%d tmp=%jd", cpu, ri, 1411 tmp); 1412 1413 if (mode == PMC_MODE_TS) { 1414 1415 /* 1416 * For sampling process-virtual PMCs, 1417 * we expect the count to be 1418 * decreasing as the 'value' 1419 * programmed into the PMC is the 1420 * number of events to be seen till 1421 * the next sampling interrupt. 1422 */ 1423 if (tmp < 0) 1424 tmp += pm->pm_sc.pm_reloadcount; 1425 mtx_pool_lock_spin(pmc_mtxpool, pm); 1426 pp->pp_pmcs[ri].pp_pmcval -= tmp; 1427 if ((int64_t) pp->pp_pmcs[ri].pp_pmcval < 0) 1428 pp->pp_pmcs[ri].pp_pmcval += 1429 pm->pm_sc.pm_reloadcount; 1430 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1431 1432 } else { 1433 1434 /* 1435 * For counting process-virtual PMCs, 1436 * we expect the count to be 1437 * increasing monotonically, modulo a 64 1438 * bit wraparound. 1439 */ 1440 KASSERT((int64_t) tmp >= 0, 1441 ("[pmc,%d] negative increment cpu=%d " 1442 "ri=%d newvalue=%jx saved=%jx " 1443 "incr=%jx", __LINE__, cpu, ri, 1444 newvalue, PMC_PCPU_SAVED(cpu,ri), tmp)); 1445 1446 mtx_pool_lock_spin(pmc_mtxpool, pm); 1447 pm->pm_gv.pm_savedvalue += tmp; 1448 pp->pp_pmcs[ri].pp_pmcval += tmp; 1449 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1450 1451 if (pm->pm_flags & PMC_F_LOG_PROCCSW) 1452 pmclog_process_proccsw(pm, pp, tmp); 1453 } 1454 } 1455 1456 /* mark hardware as free */ 1457 pcd->pcd_config_pmc(cpu, adjri, NULL); 1458 } 1459 1460 /* 1461 * perform any other architecture/cpu dependent thread 1462 * switch out functions. 1463 */ 1464 1465 (void) (*md->pmd_switch_out)(pc, pp); 1466 1467 critical_exit(); 1468 } 1469 1470 /* 1471 * Log a KLD operation. 1472 */ 1473 1474 static void 1475 pmc_process_kld_load(struct pmckern_map_in *pkm) 1476 { 1477 struct pmc_owner *po; 1478 1479 sx_assert(&pmc_sx, SX_LOCKED); 1480 1481 /* 1482 * Notify owners of system sampling PMCs about KLD operations. 1483 */ 1484 1485 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1486 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1487 pmclog_process_map_in(po, (pid_t) -1, pkm->pm_address, 1488 (char *) pkm->pm_file); 1489 1490 /* 1491 * TODO: Notify owners of (all) process-sampling PMCs too. 1492 */ 1493 1494 return; 1495 } 1496 1497 static void 1498 pmc_process_kld_unload(struct pmckern_map_out *pkm) 1499 { 1500 struct pmc_owner *po; 1501 1502 sx_assert(&pmc_sx, SX_LOCKED); 1503 1504 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1505 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1506 pmclog_process_map_out(po, (pid_t) -1, 1507 pkm->pm_address, pkm->pm_address + pkm->pm_size); 1508 1509 /* 1510 * TODO: Notify owners of process-sampling PMCs. 1511 */ 1512 } 1513 1514 /* 1515 * A mapping change for a process. 1516 */ 1517 1518 static void 1519 pmc_process_mmap(struct thread *td, struct pmckern_map_in *pkm) 1520 { 1521 int ri; 1522 pid_t pid; 1523 char *fullpath, *freepath; 1524 const struct pmc *pm; 1525 struct pmc_owner *po; 1526 const struct pmc_process *pp; 1527 1528 freepath = fullpath = NULL; 1529 pmc_getfilename((struct vnode *) pkm->pm_file, &fullpath, &freepath); 1530 1531 pid = td->td_proc->p_pid; 1532 1533 /* Inform owners of all system-wide sampling PMCs. */ 1534 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1535 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1536 pmclog_process_map_in(po, pid, pkm->pm_address, fullpath); 1537 1538 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1539 goto done; 1540 1541 /* 1542 * Inform sampling PMC owners tracking this process. 1543 */ 1544 for (ri = 0; ri < md->pmd_npmc; ri++) 1545 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1546 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1547 pmclog_process_map_in(pm->pm_owner, 1548 pid, pkm->pm_address, fullpath); 1549 1550 done: 1551 if (freepath) 1552 free(freepath, M_TEMP); 1553 } 1554 1555 1556 /* 1557 * Log an munmap request. 1558 */ 1559 1560 static void 1561 pmc_process_munmap(struct thread *td, struct pmckern_map_out *pkm) 1562 { 1563 int ri; 1564 pid_t pid; 1565 struct pmc_owner *po; 1566 const struct pmc *pm; 1567 const struct pmc_process *pp; 1568 1569 pid = td->td_proc->p_pid; 1570 1571 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1572 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1573 pmclog_process_map_out(po, pid, pkm->pm_address, 1574 pkm->pm_address + pkm->pm_size); 1575 1576 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1577 return; 1578 1579 for (ri = 0; ri < md->pmd_npmc; ri++) 1580 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1581 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1582 pmclog_process_map_out(pm->pm_owner, pid, 1583 pkm->pm_address, pkm->pm_address + pkm->pm_size); 1584 } 1585 1586 /* 1587 * Log mapping information about the kernel. 1588 */ 1589 1590 static void 1591 pmc_log_kernel_mappings(struct pmc *pm) 1592 { 1593 struct pmc_owner *po; 1594 struct pmckern_map_in *km, *kmbase; 1595 1596 sx_assert(&pmc_sx, SX_LOCKED); 1597 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 1598 ("[pmc,%d] non-sampling PMC (%p) desires mapping information", 1599 __LINE__, (void *) pm)); 1600 1601 po = pm->pm_owner; 1602 1603 if (po->po_flags & PMC_PO_INITIAL_MAPPINGS_DONE) 1604 return; 1605 1606 /* 1607 * Log the current set of kernel modules. 1608 */ 1609 kmbase = linker_hwpmc_list_objects(); 1610 for (km = kmbase; km->pm_file != NULL; km++) { 1611 PMCDBG(LOG,REG,1,"%s %p", (char *) km->pm_file, 1612 (void *) km->pm_address); 1613 pmclog_process_map_in(po, (pid_t) -1, km->pm_address, 1614 km->pm_file); 1615 } 1616 free(kmbase, M_LINKER); 1617 1618 po->po_flags |= PMC_PO_INITIAL_MAPPINGS_DONE; 1619 } 1620 1621 /* 1622 * Log the mappings for a single process. 1623 */ 1624 1625 static void 1626 pmc_log_process_mappings(struct pmc_owner *po, struct proc *p) 1627 { 1628 vm_map_t map; 1629 struct vnode *vp; 1630 struct vmspace *vm; 1631 vm_map_entry_t entry; 1632 vm_offset_t last_end; 1633 u_int last_timestamp; 1634 struct vnode *last_vp; 1635 vm_offset_t start_addr; 1636 vm_object_t obj, lobj, tobj; 1637 char *fullpath, *freepath; 1638 1639 last_vp = NULL; 1640 last_end = (vm_offset_t) 0; 1641 fullpath = freepath = NULL; 1642 1643 if ((vm = vmspace_acquire_ref(p)) == NULL) 1644 return; 1645 1646 map = &vm->vm_map; 1647 vm_map_lock_read(map); 1648 1649 for (entry = map->header.next; entry != &map->header; entry = entry->next) { 1650 1651 if (entry == NULL) { 1652 PMCDBG(LOG,OPS,2, "hwpmc: vm_map entry unexpectedly " 1653 "NULL! pid=%d vm_map=%p\n", p->p_pid, map); 1654 break; 1655 } 1656 1657 /* 1658 * We only care about executable map entries. 1659 */ 1660 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) || 1661 !(entry->protection & VM_PROT_EXECUTE) || 1662 (entry->object.vm_object == NULL)) { 1663 continue; 1664 } 1665 1666 obj = entry->object.vm_object; 1667 VM_OBJECT_LOCK(obj); 1668 1669 /* 1670 * Walk the backing_object list to find the base 1671 * (non-shadowed) vm_object. 1672 */ 1673 for (lobj = tobj = obj; tobj != NULL; tobj = tobj->backing_object) { 1674 if (tobj != obj) 1675 VM_OBJECT_LOCK(tobj); 1676 if (lobj != obj) 1677 VM_OBJECT_UNLOCK(lobj); 1678 lobj = tobj; 1679 } 1680 1681 /* 1682 * At this point lobj is the base vm_object and it is locked. 1683 */ 1684 if (lobj == NULL) { 1685 PMCDBG(LOG,OPS,2, "hwpmc: lobj unexpectedly NULL! pid=%d " 1686 "vm_map=%p vm_obj=%p\n", p->p_pid, map, obj); 1687 VM_OBJECT_UNLOCK(obj); 1688 continue; 1689 } 1690 1691 if (lobj->type != OBJT_VNODE || lobj->handle == NULL) { 1692 if (lobj != obj) 1693 VM_OBJECT_UNLOCK(lobj); 1694 VM_OBJECT_UNLOCK(obj); 1695 continue; 1696 } 1697 1698 /* 1699 * Skip contiguous regions that point to the same 1700 * vnode, so we don't emit redundant MAP-IN 1701 * directives. 1702 */ 1703 if (entry->start == last_end && lobj->handle == last_vp) { 1704 last_end = entry->end; 1705 if (lobj != obj) 1706 VM_OBJECT_UNLOCK(lobj); 1707 VM_OBJECT_UNLOCK(obj); 1708 continue; 1709 } 1710 1711 /* 1712 * We don't want to keep the proc's vm_map or this 1713 * vm_object locked while we walk the pathname, since 1714 * vn_fullpath() can sleep. However, if we drop the 1715 * lock, it's possible for concurrent activity to 1716 * modify the vm_map list. To protect against this, 1717 * we save the vm_map timestamp before we release the 1718 * lock, and check it after we reacquire the lock 1719 * below. 1720 */ 1721 start_addr = entry->start; 1722 last_end = entry->end; 1723 last_timestamp = map->timestamp; 1724 vm_map_unlock_read(map); 1725 1726 vp = lobj->handle; 1727 vref(vp); 1728 if (lobj != obj) 1729 VM_OBJECT_UNLOCK(lobj); 1730 1731 VM_OBJECT_UNLOCK(obj); 1732 1733 freepath = NULL; 1734 pmc_getfilename(vp, &fullpath, &freepath); 1735 last_vp = vp; 1736 vrele(vp); 1737 vp = NULL; 1738 pmclog_process_map_in(po, p->p_pid, start_addr, fullpath); 1739 if (freepath) 1740 free(freepath, M_TEMP); 1741 1742 vm_map_lock_read(map); 1743 1744 /* 1745 * If our saved timestamp doesn't match, this means 1746 * that the vm_map was modified out from under us and 1747 * we can't trust our current "entry" pointer. Do a 1748 * new lookup for this entry. If there is no entry 1749 * for this address range, vm_map_lookup_entry() will 1750 * return the previous one, so we always want to go to 1751 * entry->next on the next loop iteration. 1752 * 1753 * There is an edge condition here that can occur if 1754 * there is no entry at or before this address. In 1755 * this situation, vm_map_lookup_entry returns 1756 * &map->header, which would cause our loop to abort 1757 * without processing the rest of the map. However, 1758 * in practice this will never happen for process 1759 * vm_map. This is because the executable's text 1760 * segment is the first mapping in the proc's address 1761 * space, and this mapping is never removed until the 1762 * process exits, so there will always be a non-header 1763 * entry at or before the requested address for 1764 * vm_map_lookup_entry to return. 1765 */ 1766 if (map->timestamp != last_timestamp) 1767 vm_map_lookup_entry(map, last_end - 1, &entry); 1768 } 1769 1770 vm_map_unlock_read(map); 1771 vmspace_free(vm); 1772 return; 1773 } 1774 1775 /* 1776 * Log mappings for all processes in the system. 1777 */ 1778 1779 static void 1780 pmc_log_all_process_mappings(struct pmc_owner *po) 1781 { 1782 struct proc *p, *top; 1783 1784 sx_assert(&pmc_sx, SX_XLOCKED); 1785 1786 if ((p = pfind(1)) == NULL) 1787 panic("[pmc,%d] Cannot find init", __LINE__); 1788 1789 PROC_UNLOCK(p); 1790 1791 sx_slock(&proctree_lock); 1792 1793 top = p; 1794 1795 for (;;) { 1796 pmc_log_process_mappings(po, p); 1797 if (!LIST_EMPTY(&p->p_children)) 1798 p = LIST_FIRST(&p->p_children); 1799 else for (;;) { 1800 if (p == top) 1801 goto done; 1802 if (LIST_NEXT(p, p_sibling)) { 1803 p = LIST_NEXT(p, p_sibling); 1804 break; 1805 } 1806 p = p->p_pptr; 1807 } 1808 } 1809 done: 1810 sx_sunlock(&proctree_lock); 1811 } 1812 1813 /* 1814 * The 'hook' invoked from the kernel proper 1815 */ 1816 1817 1818 #ifdef DEBUG 1819 const char *pmc_hooknames[] = { 1820 /* these strings correspond to PMC_FN_* in <sys/pmckern.h> */ 1821 "", 1822 "EXEC", 1823 "CSW-IN", 1824 "CSW-OUT", 1825 "SAMPLE", 1826 "KLDLOAD", 1827 "KLDUNLOAD", 1828 "MMAP", 1829 "MUNMAP", 1830 "CALLCHAIN" 1831 }; 1832 #endif 1833 1834 static int 1835 pmc_hook_handler(struct thread *td, int function, void *arg) 1836 { 1837 1838 PMCDBG(MOD,PMH,1, "hook td=%p func=%d \"%s\" arg=%p", td, function, 1839 pmc_hooknames[function], arg); 1840 1841 switch (function) 1842 { 1843 1844 /* 1845 * Process exec() 1846 */ 1847 1848 case PMC_FN_PROCESS_EXEC: 1849 { 1850 char *fullpath, *freepath; 1851 unsigned int ri; 1852 int is_using_hwpmcs; 1853 struct pmc *pm; 1854 struct proc *p; 1855 struct pmc_owner *po; 1856 struct pmc_process *pp; 1857 struct pmckern_procexec *pk; 1858 1859 sx_assert(&pmc_sx, SX_XLOCKED); 1860 1861 p = td->td_proc; 1862 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 1863 1864 pk = (struct pmckern_procexec *) arg; 1865 1866 /* Inform owners of SS mode PMCs of the exec event. */ 1867 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1868 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1869 pmclog_process_procexec(po, PMC_ID_INVALID, 1870 p->p_pid, pk->pm_entryaddr, fullpath); 1871 1872 PROC_LOCK(p); 1873 is_using_hwpmcs = p->p_flag & P_HWPMC; 1874 PROC_UNLOCK(p); 1875 1876 if (!is_using_hwpmcs) { 1877 if (freepath) 1878 free(freepath, M_TEMP); 1879 break; 1880 } 1881 1882 /* 1883 * PMCs are not inherited across an exec(): remove any 1884 * PMCs that this process is the owner of. 1885 */ 1886 1887 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 1888 pmc_remove_owner(po); 1889 pmc_destroy_owner_descriptor(po); 1890 } 1891 1892 /* 1893 * If the process being exec'ed is not the target of any 1894 * PMC, we are done. 1895 */ 1896 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) { 1897 if (freepath) 1898 free(freepath, M_TEMP); 1899 break; 1900 } 1901 1902 /* 1903 * Log the exec event to all monitoring owners. Skip 1904 * owners who have already recieved the event because 1905 * they had system sampling PMCs active. 1906 */ 1907 for (ri = 0; ri < md->pmd_npmc; ri++) 1908 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 1909 po = pm->pm_owner; 1910 if (po->po_sscount == 0 && 1911 po->po_flags & PMC_PO_OWNS_LOGFILE) 1912 pmclog_process_procexec(po, pm->pm_id, 1913 p->p_pid, pk->pm_entryaddr, 1914 fullpath); 1915 } 1916 1917 if (freepath) 1918 free(freepath, M_TEMP); 1919 1920 1921 PMCDBG(PRC,EXC,1, "exec proc=%p (%d, %s) cred-changed=%d", 1922 p, p->p_pid, p->p_comm, pk->pm_credentialschanged); 1923 1924 if (pk->pm_credentialschanged == 0) /* no change */ 1925 break; 1926 1927 /* 1928 * If the newly exec()'ed process has a different credential 1929 * than before, allow it to be the target of a PMC only if 1930 * the PMC's owner has sufficient priviledge. 1931 */ 1932 1933 for (ri = 0; ri < md->pmd_npmc; ri++) 1934 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) 1935 if (pmc_can_attach(pm, td->td_proc) != 0) 1936 pmc_detach_one_process(td->td_proc, 1937 pm, PMC_FLAG_NONE); 1938 1939 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= (int) md->pmd_npmc, 1940 ("[pmc,%d] Illegal ref count %d on pp %p", __LINE__, 1941 pp->pp_refcnt, pp)); 1942 1943 /* 1944 * If this process is no longer the target of any 1945 * PMCs, we can remove the process entry and free 1946 * up space. 1947 */ 1948 1949 if (pp->pp_refcnt == 0) { 1950 pmc_remove_process_descriptor(pp); 1951 free(pp, M_PMC); 1952 break; 1953 } 1954 1955 } 1956 break; 1957 1958 case PMC_FN_CSW_IN: 1959 pmc_process_csw_in(td); 1960 break; 1961 1962 case PMC_FN_CSW_OUT: 1963 pmc_process_csw_out(td); 1964 break; 1965 1966 /* 1967 * Process accumulated PC samples. 1968 * 1969 * This function is expected to be called by hardclock() for 1970 * each CPU that has accumulated PC samples. 1971 * 1972 * This function is to be executed on the CPU whose samples 1973 * are being processed. 1974 */ 1975 case PMC_FN_DO_SAMPLES: 1976 1977 /* 1978 * Clear the cpu specific bit in the CPU mask before 1979 * do the rest of the processing. If the NMI handler 1980 * gets invoked after the "atomic_clear_int()" call 1981 * below but before "pmc_process_samples()" gets 1982 * around to processing the interrupt, then we will 1983 * come back here at the next hardclock() tick (and 1984 * may find nothing to do if "pmc_process_samples()" 1985 * had already processed the interrupt). We don't 1986 * lose the interrupt sample. 1987 */ 1988 atomic_clear_int(&pmc_cpumask, (1 << PCPU_GET(cpuid))); 1989 pmc_process_samples(PCPU_GET(cpuid)); 1990 break; 1991 1992 1993 case PMC_FN_KLD_LOAD: 1994 sx_assert(&pmc_sx, SX_LOCKED); 1995 pmc_process_kld_load((struct pmckern_map_in *) arg); 1996 break; 1997 1998 case PMC_FN_KLD_UNLOAD: 1999 sx_assert(&pmc_sx, SX_LOCKED); 2000 pmc_process_kld_unload((struct pmckern_map_out *) arg); 2001 break; 2002 2003 case PMC_FN_MMAP: 2004 sx_assert(&pmc_sx, SX_LOCKED); 2005 pmc_process_mmap(td, (struct pmckern_map_in *) arg); 2006 break; 2007 2008 case PMC_FN_MUNMAP: 2009 sx_assert(&pmc_sx, SX_LOCKED); 2010 pmc_process_munmap(td, (struct pmckern_map_out *) arg); 2011 break; 2012 2013 case PMC_FN_USER_CALLCHAIN: 2014 /* 2015 * Record a call chain. 2016 */ 2017 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 2018 __LINE__)); 2019 pmc_capture_user_callchain(PCPU_GET(cpuid), 2020 (struct trapframe *) arg); 2021 td->td_pflags &= ~TDP_CALLCHAIN; 2022 break; 2023 2024 default: 2025 #ifdef DEBUG 2026 KASSERT(0, ("[pmc,%d] unknown hook %d\n", __LINE__, function)); 2027 #endif 2028 break; 2029 2030 } 2031 2032 return 0; 2033 } 2034 2035 /* 2036 * allocate a 'struct pmc_owner' descriptor in the owner hash table. 2037 */ 2038 2039 static struct pmc_owner * 2040 pmc_allocate_owner_descriptor(struct proc *p) 2041 { 2042 uint32_t hindex; 2043 struct pmc_owner *po; 2044 struct pmc_ownerhash *poh; 2045 2046 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 2047 poh = &pmc_ownerhash[hindex]; 2048 2049 /* allocate space for N pointers and one descriptor struct */ 2050 po = malloc(sizeof(struct pmc_owner), M_PMC, M_WAITOK|M_ZERO); 2051 po->po_sscount = po->po_error = po->po_flags = po->po_logprocmaps = 0; 2052 po->po_file = NULL; 2053 po->po_owner = p; 2054 po->po_kthread = NULL; 2055 LIST_INIT(&po->po_pmcs); 2056 LIST_INSERT_HEAD(poh, po, po_next); /* insert into hash table */ 2057 2058 TAILQ_INIT(&po->po_logbuffers); 2059 mtx_init(&po->po_mtx, "pmc-owner-mtx", "pmc-per-proc", MTX_SPIN); 2060 2061 PMCDBG(OWN,ALL,1, "allocate-owner proc=%p (%d, %s) pmc-owner=%p", 2062 p, p->p_pid, p->p_comm, po); 2063 2064 return po; 2065 } 2066 2067 static void 2068 pmc_destroy_owner_descriptor(struct pmc_owner *po) 2069 { 2070 2071 PMCDBG(OWN,REL,1, "destroy-owner po=%p proc=%p (%d, %s)", 2072 po, po->po_owner, po->po_owner->p_pid, po->po_owner->p_comm); 2073 2074 mtx_destroy(&po->po_mtx); 2075 free(po, M_PMC); 2076 } 2077 2078 /* 2079 * find the descriptor corresponding to process 'p', adding or removing it 2080 * as specified by 'mode'. 2081 */ 2082 2083 static struct pmc_process * 2084 pmc_find_process_descriptor(struct proc *p, uint32_t mode) 2085 { 2086 uint32_t hindex; 2087 struct pmc_process *pp, *ppnew; 2088 struct pmc_processhash *pph; 2089 2090 hindex = PMC_HASH_PTR(p, pmc_processhashmask); 2091 pph = &pmc_processhash[hindex]; 2092 2093 ppnew = NULL; 2094 2095 /* 2096 * Pre-allocate memory in the FIND_ALLOCATE case since we 2097 * cannot call malloc(9) once we hold a spin lock. 2098 */ 2099 if (mode & PMC_FLAG_ALLOCATE) 2100 ppnew = malloc(sizeof(struct pmc_process) + md->pmd_npmc * 2101 sizeof(struct pmc_targetstate), M_PMC, M_WAITOK|M_ZERO); 2102 2103 mtx_lock_spin(&pmc_processhash_mtx); 2104 LIST_FOREACH(pp, pph, pp_next) 2105 if (pp->pp_proc == p) 2106 break; 2107 2108 if ((mode & PMC_FLAG_REMOVE) && pp != NULL) 2109 LIST_REMOVE(pp, pp_next); 2110 2111 if ((mode & PMC_FLAG_ALLOCATE) && pp == NULL && 2112 ppnew != NULL) { 2113 ppnew->pp_proc = p; 2114 LIST_INSERT_HEAD(pph, ppnew, pp_next); 2115 pp = ppnew; 2116 ppnew = NULL; 2117 } 2118 mtx_unlock_spin(&pmc_processhash_mtx); 2119 2120 if (pp != NULL && ppnew != NULL) 2121 free(ppnew, M_PMC); 2122 2123 return pp; 2124 } 2125 2126 /* 2127 * remove a process descriptor from the process hash table. 2128 */ 2129 2130 static void 2131 pmc_remove_process_descriptor(struct pmc_process *pp) 2132 { 2133 KASSERT(pp->pp_refcnt == 0, 2134 ("[pmc,%d] Removing process descriptor %p with count %d", 2135 __LINE__, pp, pp->pp_refcnt)); 2136 2137 mtx_lock_spin(&pmc_processhash_mtx); 2138 LIST_REMOVE(pp, pp_next); 2139 mtx_unlock_spin(&pmc_processhash_mtx); 2140 } 2141 2142 2143 /* 2144 * find an owner descriptor corresponding to proc 'p' 2145 */ 2146 2147 static struct pmc_owner * 2148 pmc_find_owner_descriptor(struct proc *p) 2149 { 2150 uint32_t hindex; 2151 struct pmc_owner *po; 2152 struct pmc_ownerhash *poh; 2153 2154 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 2155 poh = &pmc_ownerhash[hindex]; 2156 2157 po = NULL; 2158 LIST_FOREACH(po, poh, po_next) 2159 if (po->po_owner == p) 2160 break; 2161 2162 PMCDBG(OWN,FND,1, "find-owner proc=%p (%d, %s) hindex=0x%x -> " 2163 "pmc-owner=%p", p, p->p_pid, p->p_comm, hindex, po); 2164 2165 return po; 2166 } 2167 2168 /* 2169 * pmc_allocate_pmc_descriptor 2170 * 2171 * Allocate a pmc descriptor and initialize its 2172 * fields. 2173 */ 2174 2175 static struct pmc * 2176 pmc_allocate_pmc_descriptor(void) 2177 { 2178 struct pmc *pmc; 2179 2180 pmc = malloc(sizeof(struct pmc), M_PMC, M_WAITOK|M_ZERO); 2181 2182 if (pmc != NULL) { 2183 pmc->pm_owner = NULL; 2184 LIST_INIT(&pmc->pm_targets); 2185 } 2186 2187 PMCDBG(PMC,ALL,1, "allocate-pmc -> pmc=%p", pmc); 2188 2189 return pmc; 2190 } 2191 2192 /* 2193 * Destroy a pmc descriptor. 2194 */ 2195 2196 static void 2197 pmc_destroy_pmc_descriptor(struct pmc *pm) 2198 { 2199 (void) pm; 2200 2201 #ifdef DEBUG 2202 KASSERT(pm->pm_state == PMC_STATE_DELETED || 2203 pm->pm_state == PMC_STATE_FREE, 2204 ("[pmc,%d] destroying non-deleted PMC", __LINE__)); 2205 KASSERT(LIST_EMPTY(&pm->pm_targets), 2206 ("[pmc,%d] destroying pmc with targets", __LINE__)); 2207 KASSERT(pm->pm_owner == NULL, 2208 ("[pmc,%d] destroying pmc attached to an owner", __LINE__)); 2209 KASSERT(pm->pm_runcount == 0, 2210 ("[pmc,%d] pmc has non-zero run count %d", __LINE__, 2211 pm->pm_runcount)); 2212 #endif 2213 } 2214 2215 static void 2216 pmc_wait_for_pmc_idle(struct pmc *pm) 2217 { 2218 #ifdef DEBUG 2219 volatile int maxloop; 2220 2221 maxloop = 100 * pmc_cpu_max(); 2222 #endif 2223 2224 /* 2225 * Loop (with a forced context switch) till the PMC's runcount 2226 * comes down to zero. 2227 */ 2228 while (atomic_load_acq_32(&pm->pm_runcount) > 0) { 2229 #ifdef DEBUG 2230 maxloop--; 2231 KASSERT(maxloop > 0, 2232 ("[pmc,%d] (ri%d, rc%d) waiting too long for " 2233 "pmc to be free", __LINE__, 2234 PMC_TO_ROWINDEX(pm), pm->pm_runcount)); 2235 #endif 2236 pmc_force_context_switch(); 2237 } 2238 } 2239 2240 /* 2241 * This function does the following things: 2242 * 2243 * - detaches the PMC from hardware 2244 * - unlinks all target threads that were attached to it 2245 * - removes the PMC from its owner's list 2246 * - destroy's the PMC private mutex 2247 * 2248 * Once this function completes, the given pmc pointer can be safely 2249 * FREE'd by the caller. 2250 */ 2251 2252 static void 2253 pmc_release_pmc_descriptor(struct pmc *pm) 2254 { 2255 enum pmc_mode mode; 2256 struct pmc_hw *phw; 2257 u_int adjri, ri, cpu; 2258 struct pmc_owner *po; 2259 struct pmc_binding pb; 2260 struct pmc_process *pp; 2261 struct pmc_classdep *pcd; 2262 struct pmc_target *ptgt, *tmp; 2263 2264 sx_assert(&pmc_sx, SX_XLOCKED); 2265 2266 KASSERT(pm, ("[pmc,%d] null pmc", __LINE__)); 2267 2268 ri = PMC_TO_ROWINDEX(pm); 2269 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2270 mode = PMC_TO_MODE(pm); 2271 2272 PMCDBG(PMC,REL,1, "release-pmc pmc=%p ri=%d mode=%d", pm, ri, 2273 mode); 2274 2275 /* 2276 * First, we take the PMC off hardware. 2277 */ 2278 cpu = 0; 2279 if (PMC_IS_SYSTEM_MODE(mode)) { 2280 2281 /* 2282 * A system mode PMC runs on a specific CPU. Switch 2283 * to this CPU and turn hardware off. 2284 */ 2285 pmc_save_cpu_binding(&pb); 2286 2287 cpu = PMC_TO_CPU(pm); 2288 2289 pmc_select_cpu(cpu); 2290 2291 /* switch off non-stalled CPUs */ 2292 if (pm->pm_state == PMC_STATE_RUNNING && 2293 pm->pm_stalled == 0) { 2294 2295 phw = pmc_pcpu[cpu]->pc_hwpmcs[ri]; 2296 2297 KASSERT(phw->phw_pmc == pm, 2298 ("[pmc, %d] pmc ptr ri(%d) hw(%p) pm(%p)", 2299 __LINE__, ri, phw->phw_pmc, pm)); 2300 PMCDBG(PMC,REL,2, "stopping cpu=%d ri=%d", cpu, ri); 2301 2302 critical_enter(); 2303 pcd->pcd_stop_pmc(cpu, adjri); 2304 critical_exit(); 2305 } 2306 2307 PMCDBG(PMC,REL,2, "decfg cpu=%d ri=%d", cpu, ri); 2308 2309 critical_enter(); 2310 pcd->pcd_config_pmc(cpu, adjri, NULL); 2311 critical_exit(); 2312 2313 /* adjust the global and process count of SS mode PMCs */ 2314 if (mode == PMC_MODE_SS && pm->pm_state == PMC_STATE_RUNNING) { 2315 po = pm->pm_owner; 2316 po->po_sscount--; 2317 if (po->po_sscount == 0) { 2318 atomic_subtract_rel_int(&pmc_ss_count, 1); 2319 LIST_REMOVE(po, po_ssnext); 2320 } 2321 } 2322 2323 pm->pm_state = PMC_STATE_DELETED; 2324 2325 pmc_restore_cpu_binding(&pb); 2326 2327 /* 2328 * We could have references to this PMC structure in 2329 * the per-cpu sample queues. Wait for the queue to 2330 * drain. 2331 */ 2332 pmc_wait_for_pmc_idle(pm); 2333 2334 } else if (PMC_IS_VIRTUAL_MODE(mode)) { 2335 2336 /* 2337 * A virtual PMC could be running on multiple CPUs at 2338 * a given instant. 2339 * 2340 * By marking its state as DELETED, we ensure that 2341 * this PMC is never further scheduled on hardware. 2342 * 2343 * Then we wait till all CPUs are done with this PMC. 2344 */ 2345 pm->pm_state = PMC_STATE_DELETED; 2346 2347 2348 /* Wait for the PMCs runcount to come to zero. */ 2349 pmc_wait_for_pmc_idle(pm); 2350 2351 /* 2352 * At this point the PMC is off all CPUs and cannot be 2353 * freshly scheduled onto a CPU. It is now safe to 2354 * unlink all targets from this PMC. If a 2355 * process-record's refcount falls to zero, we remove 2356 * it from the hash table. The module-wide SX lock 2357 * protects us from races. 2358 */ 2359 LIST_FOREACH_SAFE(ptgt, &pm->pm_targets, pt_next, tmp) { 2360 pp = ptgt->pt_process; 2361 pmc_unlink_target_process(pm, pp); /* frees 'ptgt' */ 2362 2363 PMCDBG(PMC,REL,3, "pp->refcnt=%d", pp->pp_refcnt); 2364 2365 /* 2366 * If the target process record shows that no 2367 * PMCs are attached to it, reclaim its space. 2368 */ 2369 2370 if (pp->pp_refcnt == 0) { 2371 pmc_remove_process_descriptor(pp); 2372 free(pp, M_PMC); 2373 } 2374 } 2375 2376 cpu = curthread->td_oncpu; /* setup cpu for pmd_release() */ 2377 2378 } 2379 2380 /* 2381 * Release any MD resources 2382 */ 2383 (void) pcd->pcd_release_pmc(cpu, adjri, pm); 2384 2385 /* 2386 * Update row disposition 2387 */ 2388 2389 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) 2390 PMC_UNMARK_ROW_STANDALONE(ri); 2391 else 2392 PMC_UNMARK_ROW_THREAD(ri); 2393 2394 /* unlink from the owner's list */ 2395 if (pm->pm_owner) { 2396 LIST_REMOVE(pm, pm_next); 2397 pm->pm_owner = NULL; 2398 } 2399 2400 pmc_destroy_pmc_descriptor(pm); 2401 } 2402 2403 /* 2404 * Register an owner and a pmc. 2405 */ 2406 2407 static int 2408 pmc_register_owner(struct proc *p, struct pmc *pmc) 2409 { 2410 struct pmc_owner *po; 2411 2412 sx_assert(&pmc_sx, SX_XLOCKED); 2413 2414 if ((po = pmc_find_owner_descriptor(p)) == NULL) 2415 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) 2416 return ENOMEM; 2417 2418 KASSERT(pmc->pm_owner == NULL, 2419 ("[pmc,%d] attempting to own an initialized PMC", __LINE__)); 2420 pmc->pm_owner = po; 2421 2422 LIST_INSERT_HEAD(&po->po_pmcs, pmc, pm_next); 2423 2424 PROC_LOCK(p); 2425 p->p_flag |= P_HWPMC; 2426 PROC_UNLOCK(p); 2427 2428 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 2429 pmclog_process_pmcallocate(pmc); 2430 2431 PMCDBG(PMC,REG,1, "register-owner pmc-owner=%p pmc=%p", 2432 po, pmc); 2433 2434 return 0; 2435 } 2436 2437 /* 2438 * Return the current row disposition: 2439 * == 0 => FREE 2440 * > 0 => PROCESS MODE 2441 * < 0 => SYSTEM MODE 2442 */ 2443 2444 int 2445 pmc_getrowdisp(int ri) 2446 { 2447 return pmc_pmcdisp[ri]; 2448 } 2449 2450 /* 2451 * Check if a PMC at row index 'ri' can be allocated to the current 2452 * process. 2453 * 2454 * Allocation can fail if: 2455 * - the current process is already being profiled by a PMC at index 'ri', 2456 * attached to it via OP_PMCATTACH. 2457 * - the current process has already allocated a PMC at index 'ri' 2458 * via OP_ALLOCATE. 2459 */ 2460 2461 static int 2462 pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, int cpu) 2463 { 2464 enum pmc_mode mode; 2465 struct pmc *pm; 2466 struct pmc_owner *po; 2467 struct pmc_process *pp; 2468 2469 PMCDBG(PMC,ALR,1, "can-allocate-rowindex proc=%p (%d, %s) ri=%d " 2470 "cpu=%d", p, p->p_pid, p->p_comm, ri, cpu); 2471 2472 /* 2473 * We shouldn't have already allocated a process-mode PMC at 2474 * row index 'ri'. 2475 * 2476 * We shouldn't have allocated a system-wide PMC on the same 2477 * CPU and same RI. 2478 */ 2479 if ((po = pmc_find_owner_descriptor(p)) != NULL) 2480 LIST_FOREACH(pm, &po->po_pmcs, pm_next) { 2481 if (PMC_TO_ROWINDEX(pm) == ri) { 2482 mode = PMC_TO_MODE(pm); 2483 if (PMC_IS_VIRTUAL_MODE(mode)) 2484 return EEXIST; 2485 if (PMC_IS_SYSTEM_MODE(mode) && 2486 (int) PMC_TO_CPU(pm) == cpu) 2487 return EEXIST; 2488 } 2489 } 2490 2491 /* 2492 * We also shouldn't be the target of any PMC at this index 2493 * since otherwise a PMC_ATTACH to ourselves will fail. 2494 */ 2495 if ((pp = pmc_find_process_descriptor(p, 0)) != NULL) 2496 if (pp->pp_pmcs[ri].pp_pmc) 2497 return EEXIST; 2498 2499 PMCDBG(PMC,ALR,2, "can-allocate-rowindex proc=%p (%d, %s) ri=%d ok", 2500 p, p->p_pid, p->p_comm, ri); 2501 2502 return 0; 2503 } 2504 2505 /* 2506 * Check if a given PMC at row index 'ri' can be currently used in 2507 * mode 'mode'. 2508 */ 2509 2510 static int 2511 pmc_can_allocate_row(int ri, enum pmc_mode mode) 2512 { 2513 enum pmc_disp disp; 2514 2515 sx_assert(&pmc_sx, SX_XLOCKED); 2516 2517 PMCDBG(PMC,ALR,1, "can-allocate-row ri=%d mode=%d", ri, mode); 2518 2519 if (PMC_IS_SYSTEM_MODE(mode)) 2520 disp = PMC_DISP_STANDALONE; 2521 else 2522 disp = PMC_DISP_THREAD; 2523 2524 /* 2525 * check disposition for PMC row 'ri': 2526 * 2527 * Expected disposition Row-disposition Result 2528 * 2529 * STANDALONE STANDALONE or FREE proceed 2530 * STANDALONE THREAD fail 2531 * THREAD THREAD or FREE proceed 2532 * THREAD STANDALONE fail 2533 */ 2534 2535 if (!PMC_ROW_DISP_IS_FREE(ri) && 2536 !(disp == PMC_DISP_THREAD && PMC_ROW_DISP_IS_THREAD(ri)) && 2537 !(disp == PMC_DISP_STANDALONE && PMC_ROW_DISP_IS_STANDALONE(ri))) 2538 return EBUSY; 2539 2540 /* 2541 * All OK 2542 */ 2543 2544 PMCDBG(PMC,ALR,2, "can-allocate-row ri=%d mode=%d ok", ri, mode); 2545 2546 return 0; 2547 2548 } 2549 2550 /* 2551 * Find a PMC descriptor with user handle 'pmcid' for thread 'td'. 2552 */ 2553 2554 static struct pmc * 2555 pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, pmc_id_t pmcid) 2556 { 2557 struct pmc *pm; 2558 2559 KASSERT(PMC_ID_TO_ROWINDEX(pmcid) < md->pmd_npmc, 2560 ("[pmc,%d] Illegal pmc index %d (max %d)", __LINE__, 2561 PMC_ID_TO_ROWINDEX(pmcid), md->pmd_npmc)); 2562 2563 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 2564 if (pm->pm_id == pmcid) 2565 return pm; 2566 2567 return NULL; 2568 } 2569 2570 static int 2571 pmc_find_pmc(pmc_id_t pmcid, struct pmc **pmc) 2572 { 2573 2574 struct pmc *pm; 2575 struct pmc_owner *po; 2576 2577 PMCDBG(PMC,FND,1, "find-pmc id=%d", pmcid); 2578 2579 if ((po = pmc_find_owner_descriptor(curthread->td_proc)) == NULL) 2580 return ESRCH; 2581 2582 if ((pm = pmc_find_pmc_descriptor_in_process(po, pmcid)) == NULL) 2583 return EINVAL; 2584 2585 PMCDBG(PMC,FND,2, "find-pmc id=%d -> pmc=%p", pmcid, pm); 2586 2587 *pmc = pm; 2588 return 0; 2589 } 2590 2591 /* 2592 * Start a PMC. 2593 */ 2594 2595 static int 2596 pmc_start(struct pmc *pm) 2597 { 2598 enum pmc_mode mode; 2599 struct pmc_owner *po; 2600 struct pmc_binding pb; 2601 struct pmc_classdep *pcd; 2602 int adjri, error, cpu, ri; 2603 2604 KASSERT(pm != NULL, 2605 ("[pmc,%d] null pm", __LINE__)); 2606 2607 mode = PMC_TO_MODE(pm); 2608 ri = PMC_TO_ROWINDEX(pm); 2609 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2610 2611 error = 0; 2612 2613 PMCDBG(PMC,OPS,1, "start pmc=%p mode=%d ri=%d", pm, mode, ri); 2614 2615 po = pm->pm_owner; 2616 2617 /* 2618 * Disallow PMCSTART if a logfile is required but has not been 2619 * configured yet. 2620 */ 2621 if ((pm->pm_flags & PMC_F_NEEDS_LOGFILE) && 2622 (po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) 2623 return (EDOOFUS); /* programming error */ 2624 2625 /* 2626 * If this is a sampling mode PMC, log mapping information for 2627 * the kernel modules that are currently loaded. 2628 */ 2629 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 2630 pmc_log_kernel_mappings(pm); 2631 2632 if (PMC_IS_VIRTUAL_MODE(mode)) { 2633 2634 /* 2635 * If a PMCATTACH has never been done on this PMC, 2636 * attach it to its owner process. 2637 */ 2638 2639 if (LIST_EMPTY(&pm->pm_targets)) 2640 error = (pm->pm_flags & PMC_F_ATTACH_DONE) ? ESRCH : 2641 pmc_attach_process(po->po_owner, pm); 2642 2643 /* 2644 * If the PMC is attached to its owner, then force a context 2645 * switch to ensure that the MD state gets set correctly. 2646 */ 2647 2648 if (error == 0) { 2649 pm->pm_state = PMC_STATE_RUNNING; 2650 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) 2651 pmc_force_context_switch(); 2652 } 2653 2654 return (error); 2655 } 2656 2657 2658 /* 2659 * A system-wide PMC. 2660 * 2661 * Add the owner to the global list if this is a system-wide 2662 * sampling PMC. 2663 */ 2664 2665 if (mode == PMC_MODE_SS) { 2666 if (po->po_sscount == 0) { 2667 LIST_INSERT_HEAD(&pmc_ss_owners, po, po_ssnext); 2668 atomic_add_rel_int(&pmc_ss_count, 1); 2669 PMCDBG(PMC,OPS,1, "po=%p in global list", po); 2670 } 2671 po->po_sscount++; 2672 } 2673 2674 /* 2675 * Log mapping information for all existing processes in the 2676 * system. Subsequent mappings are logged as they happen; 2677 * see pmc_process_mmap(). 2678 */ 2679 if (po->po_logprocmaps == 0) { 2680 pmc_log_all_process_mappings(po); 2681 po->po_logprocmaps = 1; 2682 } 2683 2684 /* 2685 * Move to the CPU associated with this 2686 * PMC, and start the hardware. 2687 */ 2688 2689 pmc_save_cpu_binding(&pb); 2690 2691 cpu = PMC_TO_CPU(pm); 2692 2693 if (!pmc_cpu_is_active(cpu)) 2694 return (ENXIO); 2695 2696 pmc_select_cpu(cpu); 2697 2698 /* 2699 * global PMCs are configured at allocation time 2700 * so write out the initial value and start the PMC. 2701 */ 2702 2703 pm->pm_state = PMC_STATE_RUNNING; 2704 2705 critical_enter(); 2706 if ((error = pcd->pcd_write_pmc(cpu, adjri, 2707 PMC_IS_SAMPLING_MODE(mode) ? 2708 pm->pm_sc.pm_reloadcount : 2709 pm->pm_sc.pm_initial)) == 0) 2710 error = pcd->pcd_start_pmc(cpu, adjri); 2711 critical_exit(); 2712 2713 pmc_restore_cpu_binding(&pb); 2714 2715 return (error); 2716 } 2717 2718 /* 2719 * Stop a PMC. 2720 */ 2721 2722 static int 2723 pmc_stop(struct pmc *pm) 2724 { 2725 struct pmc_owner *po; 2726 struct pmc_binding pb; 2727 struct pmc_classdep *pcd; 2728 int adjri, cpu, error, ri; 2729 2730 KASSERT(pm != NULL, ("[pmc,%d] null pmc", __LINE__)); 2731 2732 PMCDBG(PMC,OPS,1, "stop pmc=%p mode=%d ri=%d", pm, 2733 PMC_TO_MODE(pm), PMC_TO_ROWINDEX(pm)); 2734 2735 pm->pm_state = PMC_STATE_STOPPED; 2736 2737 /* 2738 * If the PMC is a virtual mode one, changing the state to 2739 * non-RUNNING is enough to ensure that the PMC never gets 2740 * scheduled. 2741 * 2742 * If this PMC is current running on a CPU, then it will 2743 * handled correctly at the time its target process is context 2744 * switched out. 2745 */ 2746 2747 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 2748 return 0; 2749 2750 /* 2751 * A system-mode PMC. Move to the CPU associated with 2752 * this PMC, and stop the hardware. We update the 2753 * 'initial count' so that a subsequent PMCSTART will 2754 * resume counting from the current hardware count. 2755 */ 2756 2757 pmc_save_cpu_binding(&pb); 2758 2759 cpu = PMC_TO_CPU(pm); 2760 2761 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 2762 ("[pmc,%d] illegal cpu=%d", __LINE__, cpu)); 2763 2764 if (!pmc_cpu_is_active(cpu)) 2765 return ENXIO; 2766 2767 pmc_select_cpu(cpu); 2768 2769 ri = PMC_TO_ROWINDEX(pm); 2770 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2771 2772 critical_enter(); 2773 if ((error = pcd->pcd_stop_pmc(cpu, adjri)) == 0) 2774 error = pcd->pcd_read_pmc(cpu, adjri, &pm->pm_sc.pm_initial); 2775 critical_exit(); 2776 2777 pmc_restore_cpu_binding(&pb); 2778 2779 po = pm->pm_owner; 2780 2781 /* remove this owner from the global list of SS PMC owners */ 2782 if (PMC_TO_MODE(pm) == PMC_MODE_SS) { 2783 po->po_sscount--; 2784 if (po->po_sscount == 0) { 2785 atomic_subtract_rel_int(&pmc_ss_count, 1); 2786 LIST_REMOVE(po, po_ssnext); 2787 PMCDBG(PMC,OPS,2,"po=%p removed from global list", po); 2788 } 2789 } 2790 2791 return (error); 2792 } 2793 2794 2795 #ifdef DEBUG 2796 static const char *pmc_op_to_name[] = { 2797 #undef __PMC_OP 2798 #define __PMC_OP(N, D) #N , 2799 __PMC_OPS() 2800 NULL 2801 }; 2802 #endif 2803 2804 /* 2805 * The syscall interface 2806 */ 2807 2808 #define PMC_GET_SX_XLOCK(...) do { \ 2809 sx_xlock(&pmc_sx); \ 2810 if (pmc_hook == NULL) { \ 2811 sx_xunlock(&pmc_sx); \ 2812 return __VA_ARGS__; \ 2813 } \ 2814 } while (0) 2815 2816 #define PMC_DOWNGRADE_SX() do { \ 2817 sx_downgrade(&pmc_sx); \ 2818 is_sx_downgraded = 1; \ 2819 } while (0) 2820 2821 static int 2822 pmc_syscall_handler(struct thread *td, void *syscall_args) 2823 { 2824 int error, is_sx_downgraded, is_sx_locked, op; 2825 struct pmc_syscall_args *c; 2826 void *arg; 2827 2828 PMC_GET_SX_XLOCK(ENOSYS); 2829 2830 DROP_GIANT(); 2831 2832 is_sx_downgraded = 0; 2833 is_sx_locked = 1; 2834 2835 c = (struct pmc_syscall_args *) syscall_args; 2836 2837 op = c->pmop_code; 2838 arg = c->pmop_data; 2839 2840 PMCDBG(MOD,PMS,1, "syscall op=%d \"%s\" arg=%p", op, 2841 pmc_op_to_name[op], arg); 2842 2843 error = 0; 2844 atomic_add_int(&pmc_stats.pm_syscalls, 1); 2845 2846 switch(op) 2847 { 2848 2849 2850 /* 2851 * Configure a log file. 2852 * 2853 * XXX This OP will be reworked. 2854 */ 2855 2856 case PMC_OP_CONFIGURELOG: 2857 { 2858 struct proc *p; 2859 struct pmc *pm; 2860 struct pmc_owner *po; 2861 struct pmc_op_configurelog cl; 2862 2863 sx_assert(&pmc_sx, SX_XLOCKED); 2864 2865 if ((error = copyin(arg, &cl, sizeof(cl))) != 0) 2866 break; 2867 2868 /* mark this process as owning a log file */ 2869 p = td->td_proc; 2870 if ((po = pmc_find_owner_descriptor(p)) == NULL) 2871 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) { 2872 error = ENOMEM; 2873 break; 2874 } 2875 2876 /* 2877 * If a valid fd was passed in, try to configure that, 2878 * otherwise if 'fd' was less than zero and there was 2879 * a log file configured, flush its buffers and 2880 * de-configure it. 2881 */ 2882 if (cl.pm_logfd >= 0) { 2883 sx_xunlock(&pmc_sx); 2884 is_sx_locked = 0; 2885 error = pmclog_configure_log(md, po, cl.pm_logfd); 2886 } else if (po->po_flags & PMC_PO_OWNS_LOGFILE) { 2887 pmclog_process_closelog(po); 2888 error = pmclog_flush(po); 2889 if (error == 0) { 2890 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 2891 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 2892 pm->pm_state == PMC_STATE_RUNNING) 2893 pmc_stop(pm); 2894 error = pmclog_deconfigure_log(po); 2895 } 2896 } else 2897 error = EINVAL; 2898 2899 if (error) 2900 break; 2901 } 2902 break; 2903 2904 2905 /* 2906 * Flush a log file. 2907 */ 2908 2909 case PMC_OP_FLUSHLOG: 2910 { 2911 struct pmc_owner *po; 2912 2913 sx_assert(&pmc_sx, SX_XLOCKED); 2914 2915 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 2916 error = EINVAL; 2917 break; 2918 } 2919 2920 error = pmclog_flush(po); 2921 } 2922 break; 2923 2924 /* 2925 * Retrieve hardware configuration. 2926 */ 2927 2928 case PMC_OP_GETCPUINFO: /* CPU information */ 2929 { 2930 struct pmc_op_getcpuinfo gci; 2931 struct pmc_classinfo *pci; 2932 struct pmc_classdep *pcd; 2933 int cl; 2934 2935 gci.pm_cputype = md->pmd_cputype; 2936 gci.pm_ncpu = pmc_cpu_max(); 2937 gci.pm_npmc = md->pmd_npmc; 2938 gci.pm_nclass = md->pmd_nclass; 2939 pci = gci.pm_classes; 2940 pcd = md->pmd_classdep; 2941 for (cl = 0; cl < md->pmd_nclass; cl++, pci++, pcd++) { 2942 pci->pm_caps = pcd->pcd_caps; 2943 pci->pm_class = pcd->pcd_class; 2944 pci->pm_width = pcd->pcd_width; 2945 pci->pm_num = pcd->pcd_num; 2946 } 2947 error = copyout(&gci, arg, sizeof(gci)); 2948 } 2949 break; 2950 2951 2952 /* 2953 * Get module statistics 2954 */ 2955 2956 case PMC_OP_GETDRIVERSTATS: 2957 { 2958 struct pmc_op_getdriverstats gms; 2959 2960 bcopy(&pmc_stats, &gms, sizeof(gms)); 2961 error = copyout(&gms, arg, sizeof(gms)); 2962 } 2963 break; 2964 2965 2966 /* 2967 * Retrieve module version number 2968 */ 2969 2970 case PMC_OP_GETMODULEVERSION: 2971 { 2972 uint32_t cv, modv; 2973 2974 /* retrieve the client's idea of the ABI version */ 2975 if ((error = copyin(arg, &cv, sizeof(uint32_t))) != 0) 2976 break; 2977 /* don't service clients newer than our driver */ 2978 modv = PMC_VERSION; 2979 if ((cv & 0xFFFF0000) > (modv & 0xFFFF0000)) { 2980 error = EPROGMISMATCH; 2981 break; 2982 } 2983 error = copyout(&modv, arg, sizeof(int)); 2984 } 2985 break; 2986 2987 2988 /* 2989 * Retrieve the state of all the PMCs on a given 2990 * CPU. 2991 */ 2992 2993 case PMC_OP_GETPMCINFO: 2994 { 2995 int ari; 2996 struct pmc *pm; 2997 size_t pmcinfo_size; 2998 uint32_t cpu, n, npmc; 2999 struct pmc_owner *po; 3000 struct pmc_binding pb; 3001 struct pmc_classdep *pcd; 3002 struct pmc_info *p, *pmcinfo; 3003 struct pmc_op_getpmcinfo *gpi; 3004 3005 PMC_DOWNGRADE_SX(); 3006 3007 gpi = (struct pmc_op_getpmcinfo *) arg; 3008 3009 if ((error = copyin(&gpi->pm_cpu, &cpu, sizeof(cpu))) != 0) 3010 break; 3011 3012 if (cpu >= pmc_cpu_max()) { 3013 error = EINVAL; 3014 break; 3015 } 3016 3017 if (!pmc_cpu_is_active(cpu)) { 3018 error = ENXIO; 3019 break; 3020 } 3021 3022 /* switch to CPU 'cpu' */ 3023 pmc_save_cpu_binding(&pb); 3024 pmc_select_cpu(cpu); 3025 3026 npmc = md->pmd_npmc; 3027 3028 pmcinfo_size = npmc * sizeof(struct pmc_info); 3029 pmcinfo = malloc(pmcinfo_size, M_PMC, M_WAITOK); 3030 3031 p = pmcinfo; 3032 3033 for (n = 0; n < md->pmd_npmc; n++, p++) { 3034 3035 pcd = pmc_ri_to_classdep(md, n, &ari); 3036 3037 KASSERT(pcd != NULL, 3038 ("[pmc,%d] null pcd ri=%d", __LINE__, n)); 3039 3040 if ((error = pcd->pcd_describe(cpu, ari, p, &pm)) != 0) 3041 break; 3042 3043 if (PMC_ROW_DISP_IS_STANDALONE(n)) 3044 p->pm_rowdisp = PMC_DISP_STANDALONE; 3045 else if (PMC_ROW_DISP_IS_THREAD(n)) 3046 p->pm_rowdisp = PMC_DISP_THREAD; 3047 else 3048 p->pm_rowdisp = PMC_DISP_FREE; 3049 3050 p->pm_ownerpid = -1; 3051 3052 if (pm == NULL) /* no PMC associated */ 3053 continue; 3054 3055 po = pm->pm_owner; 3056 3057 KASSERT(po->po_owner != NULL, 3058 ("[pmc,%d] pmc_owner had a null proc pointer", 3059 __LINE__)); 3060 3061 p->pm_ownerpid = po->po_owner->p_pid; 3062 p->pm_mode = PMC_TO_MODE(pm); 3063 p->pm_event = pm->pm_event; 3064 p->pm_flags = pm->pm_flags; 3065 3066 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 3067 p->pm_reloadcount = 3068 pm->pm_sc.pm_reloadcount; 3069 } 3070 3071 pmc_restore_cpu_binding(&pb); 3072 3073 /* now copy out the PMC info collected */ 3074 if (error == 0) 3075 error = copyout(pmcinfo, &gpi->pm_pmcs, pmcinfo_size); 3076 3077 free(pmcinfo, M_PMC); 3078 } 3079 break; 3080 3081 3082 /* 3083 * Set the administrative state of a PMC. I.e. whether 3084 * the PMC is to be used or not. 3085 */ 3086 3087 case PMC_OP_PMCADMIN: 3088 { 3089 int cpu, ri; 3090 enum pmc_state request; 3091 struct pmc_cpu *pc; 3092 struct pmc_hw *phw; 3093 struct pmc_op_pmcadmin pma; 3094 struct pmc_binding pb; 3095 3096 sx_assert(&pmc_sx, SX_XLOCKED); 3097 3098 KASSERT(td == curthread, 3099 ("[pmc,%d] td != curthread", __LINE__)); 3100 3101 error = priv_check(td, PRIV_PMC_MANAGE); 3102 if (error) 3103 break; 3104 3105 if ((error = copyin(arg, &pma, sizeof(pma))) != 0) 3106 break; 3107 3108 cpu = pma.pm_cpu; 3109 3110 if (cpu < 0 || cpu >= (int) 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 request = pma.pm_state; 3121 3122 if (request != PMC_STATE_DISABLED && 3123 request != PMC_STATE_FREE) { 3124 error = EINVAL; 3125 break; 3126 } 3127 3128 ri = pma.pm_pmc; /* pmc id == row index */ 3129 if (ri < 0 || ri >= (int) md->pmd_npmc) { 3130 error = EINVAL; 3131 break; 3132 } 3133 3134 /* 3135 * We can't disable a PMC with a row-index allocated 3136 * for process virtual PMCs. 3137 */ 3138 3139 if (PMC_ROW_DISP_IS_THREAD(ri) && 3140 request == PMC_STATE_DISABLED) { 3141 error = EBUSY; 3142 break; 3143 } 3144 3145 /* 3146 * otherwise, this PMC on this CPU is either free or 3147 * in system-wide mode. 3148 */ 3149 3150 pmc_save_cpu_binding(&pb); 3151 pmc_select_cpu(cpu); 3152 3153 pc = pmc_pcpu[cpu]; 3154 phw = pc->pc_hwpmcs[ri]; 3155 3156 /* 3157 * XXX do we need some kind of 'forced' disable? 3158 */ 3159 3160 if (phw->phw_pmc == NULL) { 3161 if (request == PMC_STATE_DISABLED && 3162 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED)) { 3163 phw->phw_state &= ~PMC_PHW_FLAG_IS_ENABLED; 3164 PMC_MARK_ROW_STANDALONE(ri); 3165 } else if (request == PMC_STATE_FREE && 3166 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0) { 3167 phw->phw_state |= PMC_PHW_FLAG_IS_ENABLED; 3168 PMC_UNMARK_ROW_STANDALONE(ri); 3169 } 3170 /* other cases are a no-op */ 3171 } else 3172 error = EBUSY; 3173 3174 pmc_restore_cpu_binding(&pb); 3175 } 3176 break; 3177 3178 3179 /* 3180 * Allocate a PMC. 3181 */ 3182 3183 case PMC_OP_PMCALLOCATE: 3184 { 3185 int adjri, n; 3186 u_int cpu; 3187 uint32_t caps; 3188 struct pmc *pmc; 3189 enum pmc_mode mode; 3190 struct pmc_hw *phw; 3191 struct pmc_binding pb; 3192 struct pmc_classdep *pcd; 3193 struct pmc_op_pmcallocate pa; 3194 3195 if ((error = copyin(arg, &pa, sizeof(pa))) != 0) 3196 break; 3197 3198 caps = pa.pm_caps; 3199 mode = pa.pm_mode; 3200 cpu = pa.pm_cpu; 3201 3202 if ((mode != PMC_MODE_SS && mode != PMC_MODE_SC && 3203 mode != PMC_MODE_TS && mode != PMC_MODE_TC) || 3204 (cpu != (u_int) PMC_CPU_ANY && cpu >= pmc_cpu_max())) { 3205 error = EINVAL; 3206 break; 3207 } 3208 3209 /* 3210 * Virtual PMCs should only ask for a default CPU. 3211 * System mode PMCs need to specify a non-default CPU. 3212 */ 3213 3214 if ((PMC_IS_VIRTUAL_MODE(mode) && cpu != (u_int) PMC_CPU_ANY) || 3215 (PMC_IS_SYSTEM_MODE(mode) && cpu == (u_int) PMC_CPU_ANY)) { 3216 error = EINVAL; 3217 break; 3218 } 3219 3220 /* 3221 * Check that an inactive CPU is not being asked for. 3222 */ 3223 3224 if (PMC_IS_SYSTEM_MODE(mode) && !pmc_cpu_is_active(cpu)) { 3225 error = ENXIO; 3226 break; 3227 } 3228 3229 /* 3230 * Refuse an allocation for a system-wide PMC if this 3231 * process has been jailed, or if this process lacks 3232 * super-user credentials and the sysctl tunable 3233 * 'security.bsd.unprivileged_syspmcs' is zero. 3234 */ 3235 3236 if (PMC_IS_SYSTEM_MODE(mode)) { 3237 if (jailed(curthread->td_ucred)) { 3238 error = EPERM; 3239 break; 3240 } 3241 if (!pmc_unprivileged_syspmcs) { 3242 error = priv_check(curthread, 3243 PRIV_PMC_SYSTEM); 3244 if (error) 3245 break; 3246 } 3247 } 3248 3249 if (error) 3250 break; 3251 3252 /* 3253 * Look for valid values for 'pm_flags' 3254 */ 3255 3256 if ((pa.pm_flags & ~(PMC_F_DESCENDANTS | PMC_F_LOG_PROCCSW | 3257 PMC_F_LOG_PROCEXIT | PMC_F_CALLCHAIN)) != 0) { 3258 error = EINVAL; 3259 break; 3260 } 3261 3262 /* process logging options are not allowed for system PMCs */ 3263 if (PMC_IS_SYSTEM_MODE(mode) && (pa.pm_flags & 3264 (PMC_F_LOG_PROCCSW | PMC_F_LOG_PROCEXIT))) { 3265 error = EINVAL; 3266 break; 3267 } 3268 3269 /* 3270 * All sampling mode PMCs need to be able to interrupt the 3271 * CPU. 3272 */ 3273 if (PMC_IS_SAMPLING_MODE(mode)) 3274 caps |= PMC_CAP_INTERRUPT; 3275 3276 /* A valid class specifier should have been passed in. */ 3277 for (n = 0; n < md->pmd_nclass; n++) 3278 if (md->pmd_classdep[n].pcd_class == pa.pm_class) 3279 break; 3280 if (n == md->pmd_nclass) { 3281 error = EINVAL; 3282 break; 3283 } 3284 3285 /* The requested PMC capabilities should be feasible. */ 3286 if ((md->pmd_classdep[n].pcd_caps & caps) != caps) { 3287 error = EOPNOTSUPP; 3288 break; 3289 } 3290 3291 PMCDBG(PMC,ALL,2, "event=%d caps=0x%x mode=%d cpu=%d", 3292 pa.pm_ev, caps, mode, cpu); 3293 3294 pmc = pmc_allocate_pmc_descriptor(); 3295 pmc->pm_id = PMC_ID_MAKE_ID(cpu,pa.pm_mode,pa.pm_class, 3296 PMC_ID_INVALID); 3297 pmc->pm_event = pa.pm_ev; 3298 pmc->pm_state = PMC_STATE_FREE; 3299 pmc->pm_caps = caps; 3300 pmc->pm_flags = pa.pm_flags; 3301 3302 /* switch thread to CPU 'cpu' */ 3303 pmc_save_cpu_binding(&pb); 3304 3305 #define PMC_IS_SHAREABLE_PMC(cpu, n) \ 3306 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_state & \ 3307 PMC_PHW_FLAG_IS_SHAREABLE) 3308 #define PMC_IS_UNALLOCATED(cpu, n) \ 3309 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_pmc == NULL) 3310 3311 if (PMC_IS_SYSTEM_MODE(mode)) { 3312 pmc_select_cpu(cpu); 3313 for (n = 0; n < (int) md->pmd_npmc; n++) { 3314 pcd = pmc_ri_to_classdep(md, n, &adjri); 3315 if (pmc_can_allocate_row(n, mode) == 0 && 3316 pmc_can_allocate_rowindex( 3317 curthread->td_proc, n, cpu) == 0 && 3318 (PMC_IS_UNALLOCATED(cpu, n) || 3319 PMC_IS_SHAREABLE_PMC(cpu, n)) && 3320 pcd->pcd_allocate_pmc(cpu, adjri, pmc, 3321 &pa) == 0) 3322 break; 3323 } 3324 } else { 3325 /* Process virtual mode */ 3326 for (n = 0; n < (int) md->pmd_npmc; n++) { 3327 pcd = pmc_ri_to_classdep(md, n, &adjri); 3328 if (pmc_can_allocate_row(n, mode) == 0 && 3329 pmc_can_allocate_rowindex( 3330 curthread->td_proc, n, 3331 PMC_CPU_ANY) == 0 && 3332 pcd->pcd_allocate_pmc(curthread->td_oncpu, 3333 adjri, pmc, &pa) == 0) 3334 break; 3335 } 3336 } 3337 3338 #undef PMC_IS_UNALLOCATED 3339 #undef PMC_IS_SHAREABLE_PMC 3340 3341 pmc_restore_cpu_binding(&pb); 3342 3343 if (n == (int) md->pmd_npmc) { 3344 pmc_destroy_pmc_descriptor(pmc); 3345 free(pmc, M_PMC); 3346 pmc = NULL; 3347 error = EINVAL; 3348 break; 3349 } 3350 3351 /* Fill in the correct value in the ID field */ 3352 pmc->pm_id = PMC_ID_MAKE_ID(cpu,mode,pa.pm_class,n); 3353 3354 PMCDBG(PMC,ALL,2, "ev=%d class=%d mode=%d n=%d -> pmcid=%x", 3355 pmc->pm_event, pa.pm_class, mode, n, pmc->pm_id); 3356 3357 /* Process mode PMCs with logging enabled need log files */ 3358 if (pmc->pm_flags & (PMC_F_LOG_PROCEXIT | PMC_F_LOG_PROCCSW)) 3359 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3360 3361 /* All system mode sampling PMCs require a log file */ 3362 if (PMC_IS_SAMPLING_MODE(mode) && PMC_IS_SYSTEM_MODE(mode)) 3363 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3364 3365 /* 3366 * Configure global pmc's immediately 3367 */ 3368 3369 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pmc))) { 3370 3371 pmc_save_cpu_binding(&pb); 3372 pmc_select_cpu(cpu); 3373 3374 phw = pmc_pcpu[cpu]->pc_hwpmcs[n]; 3375 pcd = pmc_ri_to_classdep(md, n, &adjri); 3376 3377 if ((phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0 || 3378 (error = pcd->pcd_config_pmc(cpu, adjri, pmc)) != 0) { 3379 (void) pcd->pcd_release_pmc(cpu, adjri, pmc); 3380 pmc_destroy_pmc_descriptor(pmc); 3381 free(pmc, M_PMC); 3382 pmc = NULL; 3383 pmc_restore_cpu_binding(&pb); 3384 error = EPERM; 3385 break; 3386 } 3387 3388 pmc_restore_cpu_binding(&pb); 3389 } 3390 3391 pmc->pm_state = PMC_STATE_ALLOCATED; 3392 3393 /* 3394 * mark row disposition 3395 */ 3396 3397 if (PMC_IS_SYSTEM_MODE(mode)) 3398 PMC_MARK_ROW_STANDALONE(n); 3399 else 3400 PMC_MARK_ROW_THREAD(n); 3401 3402 /* 3403 * Register this PMC with the current thread as its owner. 3404 */ 3405 3406 if ((error = 3407 pmc_register_owner(curthread->td_proc, pmc)) != 0) { 3408 pmc_release_pmc_descriptor(pmc); 3409 free(pmc, M_PMC); 3410 pmc = NULL; 3411 break; 3412 } 3413 3414 /* 3415 * Return the allocated index. 3416 */ 3417 3418 pa.pm_pmcid = pmc->pm_id; 3419 3420 error = copyout(&pa, arg, sizeof(pa)); 3421 } 3422 break; 3423 3424 3425 /* 3426 * Attach a PMC to a process. 3427 */ 3428 3429 case PMC_OP_PMCATTACH: 3430 { 3431 struct pmc *pm; 3432 struct proc *p; 3433 struct pmc_op_pmcattach a; 3434 3435 sx_assert(&pmc_sx, SX_XLOCKED); 3436 3437 if ((error = copyin(arg, &a, sizeof(a))) != 0) 3438 break; 3439 3440 if (a.pm_pid < 0) { 3441 error = EINVAL; 3442 break; 3443 } else if (a.pm_pid == 0) 3444 a.pm_pid = td->td_proc->p_pid; 3445 3446 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 3447 break; 3448 3449 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) { 3450 error = EINVAL; 3451 break; 3452 } 3453 3454 /* PMCs may be (re)attached only when allocated or stopped */ 3455 if (pm->pm_state == PMC_STATE_RUNNING) { 3456 error = EBUSY; 3457 break; 3458 } else if (pm->pm_state != PMC_STATE_ALLOCATED && 3459 pm->pm_state != PMC_STATE_STOPPED) { 3460 error = EINVAL; 3461 break; 3462 } 3463 3464 /* lookup pid */ 3465 if ((p = pfind(a.pm_pid)) == NULL) { 3466 error = ESRCH; 3467 break; 3468 } 3469 3470 /* 3471 * Ignore processes that are working on exiting. 3472 */ 3473 if (p->p_flag & P_WEXIT) { 3474 error = ESRCH; 3475 PROC_UNLOCK(p); /* pfind() returns a locked process */ 3476 break; 3477 } 3478 3479 /* 3480 * we are allowed to attach a PMC to a process if 3481 * we can debug it. 3482 */ 3483 error = p_candebug(curthread, p); 3484 3485 PROC_UNLOCK(p); 3486 3487 if (error == 0) 3488 error = pmc_attach_process(p, pm); 3489 } 3490 break; 3491 3492 3493 /* 3494 * Detach an attached PMC from a process. 3495 */ 3496 3497 case PMC_OP_PMCDETACH: 3498 { 3499 struct pmc *pm; 3500 struct proc *p; 3501 struct pmc_op_pmcattach a; 3502 3503 if ((error = copyin(arg, &a, sizeof(a))) != 0) 3504 break; 3505 3506 if (a.pm_pid < 0) { 3507 error = EINVAL; 3508 break; 3509 } else if (a.pm_pid == 0) 3510 a.pm_pid = td->td_proc->p_pid; 3511 3512 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 3513 break; 3514 3515 if ((p = pfind(a.pm_pid)) == NULL) { 3516 error = ESRCH; 3517 break; 3518 } 3519 3520 /* 3521 * Treat processes that are in the process of exiting 3522 * as if they were not present. 3523 */ 3524 3525 if (p->p_flag & P_WEXIT) 3526 error = ESRCH; 3527 3528 PROC_UNLOCK(p); /* pfind() returns a locked process */ 3529 3530 if (error == 0) 3531 error = pmc_detach_process(p, pm); 3532 } 3533 break; 3534 3535 3536 /* 3537 * Retrieve the MSR number associated with the counter 3538 * 'pmc_id'. This allows processes to directly use RDPMC 3539 * instructions to read their PMCs, without the overhead of a 3540 * system call. 3541 */ 3542 3543 case PMC_OP_PMCGETMSR: 3544 { 3545 int adjri, ri; 3546 struct pmc *pm; 3547 struct pmc_target *pt; 3548 struct pmc_op_getmsr gm; 3549 struct pmc_classdep *pcd; 3550 3551 PMC_DOWNGRADE_SX(); 3552 3553 if ((error = copyin(arg, &gm, sizeof(gm))) != 0) 3554 break; 3555 3556 if ((error = pmc_find_pmc(gm.pm_pmcid, &pm)) != 0) 3557 break; 3558 3559 /* 3560 * The allocated PMC has to be a process virtual PMC, 3561 * i.e., of type MODE_T[CS]. Global PMCs can only be 3562 * read using the PMCREAD operation since they may be 3563 * allocated on a different CPU than the one we could 3564 * be running on at the time of the RDPMC instruction. 3565 * 3566 * The GETMSR operation is not allowed for PMCs that 3567 * are inherited across processes. 3568 */ 3569 3570 if (!PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)) || 3571 (pm->pm_flags & PMC_F_DESCENDANTS)) { 3572 error = EINVAL; 3573 break; 3574 } 3575 3576 /* 3577 * It only makes sense to use a RDPMC (or its 3578 * equivalent instruction on non-x86 architectures) on 3579 * a process that has allocated and attached a PMC to 3580 * itself. Conversely the PMC is only allowed to have 3581 * one process attached to it -- its owner. 3582 */ 3583 3584 if ((pt = LIST_FIRST(&pm->pm_targets)) == NULL || 3585 LIST_NEXT(pt, pt_next) != NULL || 3586 pt->pt_process->pp_proc != pm->pm_owner->po_owner) { 3587 error = EINVAL; 3588 break; 3589 } 3590 3591 ri = PMC_TO_ROWINDEX(pm); 3592 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3593 3594 /* PMC class has no 'GETMSR' support */ 3595 if (pcd->pcd_get_msr == NULL) { 3596 error = ENOSYS; 3597 break; 3598 } 3599 3600 if ((error = (*pcd->pcd_get_msr)(adjri, &gm.pm_msr)) < 0) 3601 break; 3602 3603 if ((error = copyout(&gm, arg, sizeof(gm))) < 0) 3604 break; 3605 3606 /* 3607 * Mark our process as using MSRs. Update machine 3608 * state using a forced context switch. 3609 */ 3610 3611 pt->pt_process->pp_flags |= PMC_PP_ENABLE_MSR_ACCESS; 3612 pmc_force_context_switch(); 3613 3614 } 3615 break; 3616 3617 /* 3618 * Release an allocated PMC 3619 */ 3620 3621 case PMC_OP_PMCRELEASE: 3622 { 3623 pmc_id_t pmcid; 3624 struct pmc *pm; 3625 struct pmc_owner *po; 3626 struct pmc_op_simple sp; 3627 3628 /* 3629 * Find PMC pointer for the named PMC. 3630 * 3631 * Use pmc_release_pmc_descriptor() to switch off the 3632 * PMC, remove all its target threads, and remove the 3633 * PMC from its owner's list. 3634 * 3635 * Remove the owner record if this is the last PMC 3636 * owned. 3637 * 3638 * Free up space. 3639 */ 3640 3641 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3642 break; 3643 3644 pmcid = sp.pm_pmcid; 3645 3646 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3647 break; 3648 3649 po = pm->pm_owner; 3650 pmc_release_pmc_descriptor(pm); 3651 pmc_maybe_remove_owner(po); 3652 3653 free(pm, M_PMC); 3654 } 3655 break; 3656 3657 3658 /* 3659 * Read and/or write a PMC. 3660 */ 3661 3662 case PMC_OP_PMCRW: 3663 { 3664 int adjri; 3665 struct pmc *pm; 3666 uint32_t cpu, ri; 3667 pmc_value_t oldvalue; 3668 struct pmc_binding pb; 3669 struct pmc_op_pmcrw prw; 3670 struct pmc_classdep *pcd; 3671 struct pmc_op_pmcrw *pprw; 3672 3673 PMC_DOWNGRADE_SX(); 3674 3675 if ((error = copyin(arg, &prw, sizeof(prw))) != 0) 3676 break; 3677 3678 ri = 0; 3679 PMCDBG(PMC,OPS,1, "rw id=%d flags=0x%x", prw.pm_pmcid, 3680 prw.pm_flags); 3681 3682 /* must have at least one flag set */ 3683 if ((prw.pm_flags & (PMC_F_OLDVALUE|PMC_F_NEWVALUE)) == 0) { 3684 error = EINVAL; 3685 break; 3686 } 3687 3688 /* locate pmc descriptor */ 3689 if ((error = pmc_find_pmc(prw.pm_pmcid, &pm)) != 0) 3690 break; 3691 3692 /* Can't read a PMC that hasn't been started. */ 3693 if (pm->pm_state != PMC_STATE_ALLOCATED && 3694 pm->pm_state != PMC_STATE_STOPPED && 3695 pm->pm_state != PMC_STATE_RUNNING) { 3696 error = EINVAL; 3697 break; 3698 } 3699 3700 /* writing a new value is allowed only for 'STOPPED' pmcs */ 3701 if (pm->pm_state == PMC_STATE_RUNNING && 3702 (prw.pm_flags & PMC_F_NEWVALUE)) { 3703 error = EBUSY; 3704 break; 3705 } 3706 3707 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) { 3708 3709 /* 3710 * If this PMC is attached to its owner (i.e., 3711 * the process requesting this operation) and 3712 * is running, then attempt to get an 3713 * upto-date reading from hardware for a READ. 3714 * Writes are only allowed when the PMC is 3715 * stopped, so only update the saved value 3716 * field. 3717 * 3718 * If the PMC is not running, or is not 3719 * attached to its owner, read/write to the 3720 * savedvalue field. 3721 */ 3722 3723 ri = PMC_TO_ROWINDEX(pm); 3724 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3725 3726 mtx_pool_lock_spin(pmc_mtxpool, pm); 3727 cpu = curthread->td_oncpu; 3728 3729 if (prw.pm_flags & PMC_F_OLDVALUE) { 3730 if ((pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) && 3731 (pm->pm_state == PMC_STATE_RUNNING)) 3732 error = (*pcd->pcd_read_pmc)(cpu, adjri, 3733 &oldvalue); 3734 else 3735 oldvalue = pm->pm_gv.pm_savedvalue; 3736 } 3737 if (prw.pm_flags & PMC_F_NEWVALUE) 3738 pm->pm_gv.pm_savedvalue = prw.pm_value; 3739 3740 mtx_pool_unlock_spin(pmc_mtxpool, pm); 3741 3742 } else { /* System mode PMCs */ 3743 cpu = PMC_TO_CPU(pm); 3744 ri = PMC_TO_ROWINDEX(pm); 3745 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3746 3747 if (!pmc_cpu_is_active(cpu)) { 3748 error = ENXIO; 3749 break; 3750 } 3751 3752 /* move this thread to CPU 'cpu' */ 3753 pmc_save_cpu_binding(&pb); 3754 pmc_select_cpu(cpu); 3755 3756 critical_enter(); 3757 /* save old value */ 3758 if (prw.pm_flags & PMC_F_OLDVALUE) 3759 if ((error = (*pcd->pcd_read_pmc)(cpu, adjri, 3760 &oldvalue))) 3761 goto error; 3762 /* write out new value */ 3763 if (prw.pm_flags & PMC_F_NEWVALUE) 3764 error = (*pcd->pcd_write_pmc)(cpu, adjri, 3765 prw.pm_value); 3766 error: 3767 critical_exit(); 3768 pmc_restore_cpu_binding(&pb); 3769 if (error) 3770 break; 3771 } 3772 3773 pprw = (struct pmc_op_pmcrw *) arg; 3774 3775 #ifdef DEBUG 3776 if (prw.pm_flags & PMC_F_NEWVALUE) 3777 PMCDBG(PMC,OPS,2, "rw id=%d new %jx -> old %jx", 3778 ri, prw.pm_value, oldvalue); 3779 else if (prw.pm_flags & PMC_F_OLDVALUE) 3780 PMCDBG(PMC,OPS,2, "rw id=%d -> old %jx", ri, oldvalue); 3781 #endif 3782 3783 /* return old value if requested */ 3784 if (prw.pm_flags & PMC_F_OLDVALUE) 3785 if ((error = copyout(&oldvalue, &pprw->pm_value, 3786 sizeof(prw.pm_value)))) 3787 break; 3788 3789 } 3790 break; 3791 3792 3793 /* 3794 * Set the sampling rate for a sampling mode PMC and the 3795 * initial count for a counting mode PMC. 3796 */ 3797 3798 case PMC_OP_PMCSETCOUNT: 3799 { 3800 struct pmc *pm; 3801 struct pmc_op_pmcsetcount sc; 3802 3803 PMC_DOWNGRADE_SX(); 3804 3805 if ((error = copyin(arg, &sc, sizeof(sc))) != 0) 3806 break; 3807 3808 if ((error = pmc_find_pmc(sc.pm_pmcid, &pm)) != 0) 3809 break; 3810 3811 if (pm->pm_state == PMC_STATE_RUNNING) { 3812 error = EBUSY; 3813 break; 3814 } 3815 3816 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 3817 pm->pm_sc.pm_reloadcount = sc.pm_count; 3818 else 3819 pm->pm_sc.pm_initial = sc.pm_count; 3820 } 3821 break; 3822 3823 3824 /* 3825 * Start a PMC. 3826 */ 3827 3828 case PMC_OP_PMCSTART: 3829 { 3830 pmc_id_t pmcid; 3831 struct pmc *pm; 3832 struct pmc_op_simple sp; 3833 3834 sx_assert(&pmc_sx, SX_XLOCKED); 3835 3836 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3837 break; 3838 3839 pmcid = sp.pm_pmcid; 3840 3841 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3842 break; 3843 3844 KASSERT(pmcid == pm->pm_id, 3845 ("[pmc,%d] pmcid %x != id %x", __LINE__, 3846 pm->pm_id, pmcid)); 3847 3848 if (pm->pm_state == PMC_STATE_RUNNING) /* already running */ 3849 break; 3850 else if (pm->pm_state != PMC_STATE_STOPPED && 3851 pm->pm_state != PMC_STATE_ALLOCATED) { 3852 error = EINVAL; 3853 break; 3854 } 3855 3856 error = pmc_start(pm); 3857 } 3858 break; 3859 3860 3861 /* 3862 * Stop a PMC. 3863 */ 3864 3865 case PMC_OP_PMCSTOP: 3866 { 3867 pmc_id_t pmcid; 3868 struct pmc *pm; 3869 struct pmc_op_simple sp; 3870 3871 PMC_DOWNGRADE_SX(); 3872 3873 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3874 break; 3875 3876 pmcid = sp.pm_pmcid; 3877 3878 /* 3879 * Mark the PMC as inactive and invoke the MD stop 3880 * routines if needed. 3881 */ 3882 3883 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3884 break; 3885 3886 KASSERT(pmcid == pm->pm_id, 3887 ("[pmc,%d] pmc id %x != pmcid %x", __LINE__, 3888 pm->pm_id, pmcid)); 3889 3890 if (pm->pm_state == PMC_STATE_STOPPED) /* already stopped */ 3891 break; 3892 else if (pm->pm_state != PMC_STATE_RUNNING) { 3893 error = EINVAL; 3894 break; 3895 } 3896 3897 error = pmc_stop(pm); 3898 } 3899 break; 3900 3901 3902 /* 3903 * Write a user supplied value to the log file. 3904 */ 3905 3906 case PMC_OP_WRITELOG: 3907 { 3908 struct pmc_op_writelog wl; 3909 struct pmc_owner *po; 3910 3911 PMC_DOWNGRADE_SX(); 3912 3913 if ((error = copyin(arg, &wl, sizeof(wl))) != 0) 3914 break; 3915 3916 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 3917 error = EINVAL; 3918 break; 3919 } 3920 3921 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) { 3922 error = EINVAL; 3923 break; 3924 } 3925 3926 error = pmclog_process_userlog(po, &wl); 3927 } 3928 break; 3929 3930 3931 default: 3932 error = EINVAL; 3933 break; 3934 } 3935 3936 if (is_sx_locked != 0) { 3937 if (is_sx_downgraded) 3938 sx_sunlock(&pmc_sx); 3939 else 3940 sx_xunlock(&pmc_sx); 3941 } 3942 3943 if (error) 3944 atomic_add_int(&pmc_stats.pm_syscall_errors, 1); 3945 3946 PICKUP_GIANT(); 3947 3948 return error; 3949 } 3950 3951 /* 3952 * Helper functions 3953 */ 3954 3955 3956 /* 3957 * Mark the thread as needing callchain capture and post an AST. The 3958 * actual callchain capture will be done in a context where it is safe 3959 * to take page faults. 3960 */ 3961 3962 static void 3963 pmc_post_callchain_callback(void) 3964 { 3965 struct thread *td; 3966 3967 td = curthread; 3968 3969 KASSERT((td->td_pflags & TDP_CALLCHAIN) == 0, 3970 ("[pmc,%d] thread %p already marked for callchain capture", 3971 __LINE__, (void *) td)); 3972 3973 /* 3974 * Mark this thread as needing callchain capture. 3975 * `td->td_pflags' will be safe to touch because this thread 3976 * was in user space when it was interrupted. 3977 */ 3978 td->td_pflags |= TDP_CALLCHAIN; 3979 3980 /* 3981 * Don't let this thread migrate between CPUs until callchain 3982 * capture completes. 3983 */ 3984 sched_pin(); 3985 3986 return; 3987 } 3988 3989 /* 3990 * Interrupt processing. 3991 * 3992 * Find a free slot in the per-cpu array of samples and capture the 3993 * current callchain there. If a sample was successfully added, a bit 3994 * is set in mask 'pmc_cpumask' denoting that the DO_SAMPLES hook 3995 * needs to be invoked from the clock handler. 3996 * 3997 * This function is meant to be called from an NMI handler. It cannot 3998 * use any of the locking primitives supplied by the OS. 3999 */ 4000 4001 int 4002 pmc_process_interrupt(int cpu, struct pmc *pm, struct trapframe *tf, 4003 int inuserspace) 4004 { 4005 int error, callchaindepth; 4006 struct thread *td; 4007 struct pmc_sample *ps; 4008 struct pmc_samplebuffer *psb; 4009 4010 error = 0; 4011 4012 /* 4013 * Allocate space for a sample buffer. 4014 */ 4015 psb = pmc_pcpu[cpu]->pc_sb; 4016 4017 ps = psb->ps_write; 4018 if (ps->ps_nsamples) { /* in use, reader hasn't caught up */ 4019 pm->pm_stalled = 1; 4020 atomic_add_int(&pmc_stats.pm_intr_bufferfull, 1); 4021 PMCDBG(SAM,INT,1,"(spc) cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", 4022 cpu, pm, (void *) tf, inuserspace, 4023 (int) (psb->ps_write - psb->ps_samples), 4024 (int) (psb->ps_read - psb->ps_samples)); 4025 error = ENOMEM; 4026 goto done; 4027 } 4028 4029 4030 /* Fill in entry. */ 4031 PMCDBG(SAM,INT,1,"cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", cpu, pm, 4032 (void *) tf, inuserspace, 4033 (int) (psb->ps_write - psb->ps_samples), 4034 (int) (psb->ps_read - psb->ps_samples)); 4035 4036 KASSERT(pm->pm_runcount >= 0, 4037 ("[pmc,%d] pm=%p runcount %d", __LINE__, (void *) pm, 4038 pm->pm_runcount)); 4039 4040 atomic_add_rel_32(&pm->pm_runcount, 1); /* hold onto PMC */ 4041 ps->ps_pmc = pm; 4042 if ((td = curthread) && td->td_proc) 4043 ps->ps_pid = td->td_proc->p_pid; 4044 else 4045 ps->ps_pid = -1; 4046 ps->ps_cpu = cpu; 4047 ps->ps_td = td; 4048 ps->ps_flags = inuserspace ? PMC_CC_F_USERSPACE : 0; 4049 4050 callchaindepth = (pm->pm_flags & PMC_F_CALLCHAIN) ? 4051 pmc_callchaindepth : 1; 4052 4053 if (callchaindepth == 1) 4054 ps->ps_pc[0] = PMC_TRAPFRAME_TO_PC(tf); 4055 else { 4056 /* 4057 * Kernel stack traversals can be done immediately, 4058 * while we defer to an AST for user space traversals. 4059 */ 4060 if (!inuserspace) 4061 callchaindepth = 4062 pmc_save_kernel_callchain(ps->ps_pc, 4063 callchaindepth, tf); 4064 else { 4065 pmc_post_callchain_callback(); 4066 callchaindepth = PMC_SAMPLE_INUSE; 4067 } 4068 } 4069 4070 ps->ps_nsamples = callchaindepth; /* mark entry as in use */ 4071 4072 /* increment write pointer, modulo ring buffer size */ 4073 ps++; 4074 if (ps == psb->ps_fence) 4075 psb->ps_write = psb->ps_samples; 4076 else 4077 psb->ps_write = ps; 4078 4079 done: 4080 /* mark CPU as needing processing */ 4081 atomic_set_rel_int(&pmc_cpumask, (1 << cpu)); 4082 4083 return (error); 4084 } 4085 4086 /* 4087 * Capture a user call chain. This function will be called from ast() 4088 * before control returns to userland and before the process gets 4089 * rescheduled. 4090 */ 4091 4092 static void 4093 pmc_capture_user_callchain(int cpu, struct trapframe *tf) 4094 { 4095 int i; 4096 struct pmc *pm; 4097 struct thread *td; 4098 struct pmc_sample *ps; 4099 struct pmc_samplebuffer *psb; 4100 #ifdef INVARIANTS 4101 int ncallchains; 4102 #endif 4103 4104 sched_unpin(); /* Can migrate safely now. */ 4105 4106 psb = pmc_pcpu[cpu]->pc_sb; 4107 td = curthread; 4108 4109 KASSERT(td->td_pflags & TDP_CALLCHAIN, 4110 ("[pmc,%d] Retrieving callchain for thread that doesn't want it", 4111 __LINE__)); 4112 4113 #ifdef INVARIANTS 4114 ncallchains = 0; 4115 #endif 4116 4117 /* 4118 * Iterate through all deferred callchain requests. 4119 */ 4120 4121 ps = psb->ps_samples; 4122 for (i = 0; i < pmc_nsamples; i++, ps++) { 4123 4124 if (ps->ps_nsamples != PMC_SAMPLE_INUSE) 4125 continue; 4126 if (ps->ps_td != td) 4127 continue; 4128 4129 KASSERT(ps->ps_cpu == cpu, 4130 ("[pmc,%d] cpu mismatch ps_cpu=%d pcpu=%d", __LINE__, 4131 ps->ps_cpu, PCPU_GET(cpuid))); 4132 4133 pm = ps->ps_pmc; 4134 4135 KASSERT(pm->pm_flags & PMC_F_CALLCHAIN, 4136 ("[pmc,%d] Retrieving callchain for PMC that doesn't " 4137 "want it", __LINE__)); 4138 4139 KASSERT(pm->pm_runcount > 0, 4140 ("[pmc,%d] runcount %d", __LINE__, pm->pm_runcount)); 4141 4142 /* 4143 * Retrieve the callchain and mark the sample buffer 4144 * as 'processable' by the timer tick sweep code. 4145 */ 4146 ps->ps_nsamples = pmc_save_user_callchain(ps->ps_pc, 4147 pmc_callchaindepth, tf); 4148 4149 #ifdef INVARIANTS 4150 ncallchains++; 4151 #endif 4152 4153 } 4154 4155 KASSERT(ncallchains > 0, 4156 ("[pmc,%d] cpu %d didn't find a sample to collect", __LINE__, 4157 cpu)); 4158 4159 return; 4160 } 4161 4162 4163 /* 4164 * Process saved PC samples. 4165 */ 4166 4167 static void 4168 pmc_process_samples(int cpu) 4169 { 4170 struct pmc *pm; 4171 int adjri, n; 4172 struct thread *td; 4173 struct pmc_owner *po; 4174 struct pmc_sample *ps; 4175 struct pmc_classdep *pcd; 4176 struct pmc_samplebuffer *psb; 4177 4178 KASSERT(PCPU_GET(cpuid) == cpu, 4179 ("[pmc,%d] not on the correct CPU pcpu=%d cpu=%d", __LINE__, 4180 PCPU_GET(cpuid), cpu)); 4181 4182 psb = pmc_pcpu[cpu]->pc_sb; 4183 4184 for (n = 0; n < pmc_nsamples; n++) { /* bound on #iterations */ 4185 4186 ps = psb->ps_read; 4187 if (ps->ps_nsamples == PMC_SAMPLE_FREE) 4188 break; 4189 if (ps->ps_nsamples == PMC_SAMPLE_INUSE) { 4190 /* Need a rescan at a later time. */ 4191 atomic_set_rel_int(&pmc_cpumask, (1 << cpu)); 4192 break; 4193 } 4194 4195 pm = ps->ps_pmc; 4196 4197 KASSERT(pm->pm_runcount > 0, 4198 ("[pmc,%d] pm=%p runcount %d", __LINE__, (void *) pm, 4199 pm->pm_runcount)); 4200 4201 po = pm->pm_owner; 4202 4203 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 4204 ("[pmc,%d] pmc=%p non-sampling mode=%d", __LINE__, 4205 pm, PMC_TO_MODE(pm))); 4206 4207 /* Ignore PMCs that have been switched off */ 4208 if (pm->pm_state != PMC_STATE_RUNNING) 4209 goto entrydone; 4210 4211 PMCDBG(SAM,OPS,1,"cpu=%d pm=%p n=%d fl=%x wr=%d rd=%d", cpu, 4212 pm, ps->ps_nsamples, ps->ps_flags, 4213 (int) (psb->ps_write - psb->ps_samples), 4214 (int) (psb->ps_read - psb->ps_samples)); 4215 4216 /* 4217 * If this is a process-mode PMC that is attached to 4218 * its owner, and if the PC is in user mode, update 4219 * profiling statistics like timer-based profiling 4220 * would have done. 4221 */ 4222 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) { 4223 if (ps->ps_flags & PMC_CC_F_USERSPACE) { 4224 td = FIRST_THREAD_IN_PROC(po->po_owner); 4225 addupc_intr(td, ps->ps_pc[0], 1); 4226 } 4227 goto entrydone; 4228 } 4229 4230 /* 4231 * Otherwise, this is either a sampling mode PMC that 4232 * is attached to a different process than its owner, 4233 * or a system-wide sampling PMC. Dispatch a log 4234 * entry to the PMC's owner process. 4235 */ 4236 4237 pmclog_process_callchain(pm, ps); 4238 4239 entrydone: 4240 ps->ps_nsamples = 0; /* mark entry as free */ 4241 atomic_subtract_rel_32(&pm->pm_runcount, 1); 4242 4243 /* increment read pointer, modulo sample size */ 4244 if (++ps == psb->ps_fence) 4245 psb->ps_read = psb->ps_samples; 4246 else 4247 psb->ps_read = ps; 4248 } 4249 4250 atomic_add_int(&pmc_stats.pm_log_sweeps, 1); 4251 4252 /* Do not re-enable stalled PMCs if we failed to process any samples */ 4253 if (n == 0) 4254 return; 4255 4256 /* 4257 * Restart any stalled sampling PMCs on this CPU. 4258 * 4259 * If the NMI handler sets the pm_stalled field of a PMC after 4260 * the check below, we'll end up processing the stalled PMC at 4261 * the next hardclock tick. 4262 */ 4263 for (n = 0; n < md->pmd_npmc; n++) { 4264 pcd = pmc_ri_to_classdep(md, n, &adjri); 4265 KASSERT(pcd != NULL, 4266 ("[pmc,%d] null pcd ri=%d", __LINE__, n)); 4267 (void) (*pcd->pcd_get_config)(cpu,adjri,&pm); 4268 4269 if (pm == NULL || /* !cfg'ed */ 4270 pm->pm_state != PMC_STATE_RUNNING || /* !active */ 4271 !PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) || /* !sampling */ 4272 pm->pm_stalled == 0) /* !stalled */ 4273 continue; 4274 4275 pm->pm_stalled = 0; 4276 (*pcd->pcd_start_pmc)(cpu, adjri); 4277 } 4278 } 4279 4280 /* 4281 * Event handlers. 4282 */ 4283 4284 /* 4285 * Handle a process exit. 4286 * 4287 * Remove this process from all hash tables. If this process 4288 * owned any PMCs, turn off those PMCs and deallocate them, 4289 * removing any associations with target processes. 4290 * 4291 * This function will be called by the last 'thread' of a 4292 * process. 4293 * 4294 * XXX This eventhandler gets called early in the exit process. 4295 * Consider using a 'hook' invocation from thread_exit() or equivalent 4296 * spot. Another negative is that kse_exit doesn't seem to call 4297 * exit1() [??]. 4298 * 4299 */ 4300 4301 static void 4302 pmc_process_exit(void *arg __unused, struct proc *p) 4303 { 4304 struct pmc *pm; 4305 int adjri, cpu; 4306 unsigned int ri; 4307 int is_using_hwpmcs; 4308 struct pmc_owner *po; 4309 struct pmc_process *pp; 4310 struct pmc_classdep *pcd; 4311 pmc_value_t newvalue, tmp; 4312 4313 PROC_LOCK(p); 4314 is_using_hwpmcs = p->p_flag & P_HWPMC; 4315 PROC_UNLOCK(p); 4316 4317 /* 4318 * Log a sysexit event to all SS PMC owners. 4319 */ 4320 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4321 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4322 pmclog_process_sysexit(po, p->p_pid); 4323 4324 if (!is_using_hwpmcs) 4325 return; 4326 4327 PMC_GET_SX_XLOCK(); 4328 PMCDBG(PRC,EXT,1,"process-exit proc=%p (%d, %s)", p, p->p_pid, 4329 p->p_comm); 4330 4331 /* 4332 * Since this code is invoked by the last thread in an exiting 4333 * process, we would have context switched IN at some prior 4334 * point. However, with PREEMPTION, kernel mode context 4335 * switches may happen any time, so we want to disable a 4336 * context switch OUT till we get any PMCs targetting this 4337 * process off the hardware. 4338 * 4339 * We also need to atomically remove this process' 4340 * entry from our target process hash table, using 4341 * PMC_FLAG_REMOVE. 4342 */ 4343 PMCDBG(PRC,EXT,1, "process-exit proc=%p (%d, %s)", p, p->p_pid, 4344 p->p_comm); 4345 4346 critical_enter(); /* no preemption */ 4347 4348 cpu = curthread->td_oncpu; 4349 4350 if ((pp = pmc_find_process_descriptor(p, 4351 PMC_FLAG_REMOVE)) != NULL) { 4352 4353 PMCDBG(PRC,EXT,2, 4354 "process-exit proc=%p pmc-process=%p", p, pp); 4355 4356 /* 4357 * The exiting process could the target of 4358 * some PMCs which will be running on 4359 * currently executing CPU. 4360 * 4361 * We need to turn these PMCs off like we 4362 * would do at context switch OUT time. 4363 */ 4364 for (ri = 0; ri < md->pmd_npmc; ri++) { 4365 4366 /* 4367 * Pick up the pmc pointer from hardware 4368 * state similar to the CSW_OUT code. 4369 */ 4370 pm = NULL; 4371 4372 pcd = pmc_ri_to_classdep(md, ri, &adjri); 4373 4374 (void) (*pcd->pcd_get_config)(cpu, adjri, &pm); 4375 4376 PMCDBG(PRC,EXT,2, "ri=%d pm=%p", ri, pm); 4377 4378 if (pm == NULL || 4379 !PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 4380 continue; 4381 4382 PMCDBG(PRC,EXT,2, "ppmcs[%d]=%p pm=%p " 4383 "state=%d", ri, pp->pp_pmcs[ri].pp_pmc, 4384 pm, pm->pm_state); 4385 4386 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 4387 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 4388 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 4389 4390 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 4391 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", 4392 __LINE__, pm, ri, pp->pp_pmcs[ri].pp_pmc)); 4393 4394 (void) pcd->pcd_stop_pmc(cpu, adjri); 4395 4396 KASSERT(pm->pm_runcount > 0, 4397 ("[pmc,%d] bad runcount ri %d rc %d", 4398 __LINE__, ri, pm->pm_runcount)); 4399 4400 /* Stop hardware only if it is actually running */ 4401 if (pm->pm_state == PMC_STATE_RUNNING && 4402 pm->pm_stalled == 0) { 4403 pcd->pcd_read_pmc(cpu, adjri, &newvalue); 4404 tmp = newvalue - 4405 PMC_PCPU_SAVED(cpu,ri); 4406 4407 mtx_pool_lock_spin(pmc_mtxpool, pm); 4408 pm->pm_gv.pm_savedvalue += tmp; 4409 pp->pp_pmcs[ri].pp_pmcval += tmp; 4410 mtx_pool_unlock_spin(pmc_mtxpool, pm); 4411 } 4412 4413 atomic_subtract_rel_32(&pm->pm_runcount,1); 4414 4415 KASSERT((int) pm->pm_runcount >= 0, 4416 ("[pmc,%d] runcount is %d", __LINE__, ri)); 4417 4418 (void) pcd->pcd_config_pmc(cpu, adjri, NULL); 4419 } 4420 4421 /* 4422 * Inform the MD layer of this pseudo "context switch 4423 * out" 4424 */ 4425 (void) md->pmd_switch_out(pmc_pcpu[cpu], pp); 4426 4427 critical_exit(); /* ok to be pre-empted now */ 4428 4429 /* 4430 * Unlink this process from the PMCs that are 4431 * targetting it. This will send a signal to 4432 * all PMC owner's whose PMCs are orphaned. 4433 * 4434 * Log PMC value at exit time if requested. 4435 */ 4436 for (ri = 0; ri < md->pmd_npmc; ri++) 4437 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 4438 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 4439 PMC_IS_COUNTING_MODE(PMC_TO_MODE(pm))) 4440 pmclog_process_procexit(pm, pp); 4441 pmc_unlink_target_process(pm, pp); 4442 } 4443 free(pp, M_PMC); 4444 4445 } else 4446 critical_exit(); /* pp == NULL */ 4447 4448 4449 /* 4450 * If the process owned PMCs, free them up and free up 4451 * memory. 4452 */ 4453 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 4454 pmc_remove_owner(po); 4455 pmc_destroy_owner_descriptor(po); 4456 } 4457 4458 sx_xunlock(&pmc_sx); 4459 } 4460 4461 /* 4462 * Handle a process fork. 4463 * 4464 * If the parent process 'p1' is under HWPMC monitoring, then copy 4465 * over any attached PMCs that have 'do_descendants' semantics. 4466 */ 4467 4468 static void 4469 pmc_process_fork(void *arg __unused, struct proc *p1, struct proc *newproc, 4470 int flags) 4471 { 4472 int is_using_hwpmcs; 4473 unsigned int ri; 4474 uint32_t do_descendants; 4475 struct pmc *pm; 4476 struct pmc_owner *po; 4477 struct pmc_process *ppnew, *ppold; 4478 4479 (void) flags; /* unused parameter */ 4480 4481 PROC_LOCK(p1); 4482 is_using_hwpmcs = p1->p_flag & P_HWPMC; 4483 PROC_UNLOCK(p1); 4484 4485 /* 4486 * If there are system-wide sampling PMCs active, we need to 4487 * log all fork events to their owner's logs. 4488 */ 4489 4490 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4491 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4492 pmclog_process_procfork(po, p1->p_pid, newproc->p_pid); 4493 4494 if (!is_using_hwpmcs) 4495 return; 4496 4497 PMC_GET_SX_XLOCK(); 4498 PMCDBG(PMC,FRK,1, "process-fork proc=%p (%d, %s) -> %p", p1, 4499 p1->p_pid, p1->p_comm, newproc); 4500 4501 /* 4502 * If the parent process (curthread->td_proc) is a 4503 * target of any PMCs, look for PMCs that are to be 4504 * inherited, and link these into the new process 4505 * descriptor. 4506 */ 4507 if ((ppold = pmc_find_process_descriptor(curthread->td_proc, 4508 PMC_FLAG_NONE)) == NULL) 4509 goto done; /* nothing to do */ 4510 4511 do_descendants = 0; 4512 for (ri = 0; ri < md->pmd_npmc; ri++) 4513 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL) 4514 do_descendants |= pm->pm_flags & PMC_F_DESCENDANTS; 4515 if (do_descendants == 0) /* nothing to do */ 4516 goto done; 4517 4518 /* allocate a descriptor for the new process */ 4519 if ((ppnew = pmc_find_process_descriptor(newproc, 4520 PMC_FLAG_ALLOCATE)) == NULL) 4521 goto done; 4522 4523 /* 4524 * Run through all PMCs that were targeting the old process 4525 * and which specified F_DESCENDANTS and attach them to the 4526 * new process. 4527 * 4528 * Log the fork event to all owners of PMCs attached to this 4529 * process, if not already logged. 4530 */ 4531 for (ri = 0; ri < md->pmd_npmc; ri++) 4532 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL && 4533 (pm->pm_flags & PMC_F_DESCENDANTS)) { 4534 pmc_link_target_process(pm, ppnew); 4535 po = pm->pm_owner; 4536 if (po->po_sscount == 0 && 4537 po->po_flags & PMC_PO_OWNS_LOGFILE) 4538 pmclog_process_procfork(po, p1->p_pid, 4539 newproc->p_pid); 4540 } 4541 4542 /* 4543 * Now mark the new process as being tracked by this driver. 4544 */ 4545 PROC_LOCK(newproc); 4546 newproc->p_flag |= P_HWPMC; 4547 PROC_UNLOCK(newproc); 4548 4549 done: 4550 sx_xunlock(&pmc_sx); 4551 } 4552 4553 4554 /* 4555 * initialization 4556 */ 4557 4558 static const char *pmc_name_of_pmcclass[] = { 4559 #undef __PMC_CLASS 4560 #define __PMC_CLASS(N) #N , 4561 __PMC_CLASSES() 4562 }; 4563 4564 static int 4565 pmc_initialize(void) 4566 { 4567 int c, cpu, error, n, ri; 4568 unsigned int maxcpu; 4569 struct pmc_binding pb; 4570 struct pmc_sample *ps; 4571 struct pmc_classdep *pcd; 4572 struct pmc_samplebuffer *sb; 4573 4574 md = NULL; 4575 error = 0; 4576 4577 #ifdef DEBUG 4578 /* parse debug flags first */ 4579 if (TUNABLE_STR_FETCH(PMC_SYSCTL_NAME_PREFIX "debugflags", 4580 pmc_debugstr, sizeof(pmc_debugstr))) 4581 pmc_debugflags_parse(pmc_debugstr, 4582 pmc_debugstr+strlen(pmc_debugstr)); 4583 #endif 4584 4585 PMCDBG(MOD,INI,0, "PMC Initialize (version %x)", PMC_VERSION); 4586 4587 /* check kernel version */ 4588 if (pmc_kernel_version != PMC_VERSION) { 4589 if (pmc_kernel_version == 0) 4590 printf("hwpmc: this kernel has not been compiled with " 4591 "'options HWPMC_HOOKS'.\n"); 4592 else 4593 printf("hwpmc: kernel version (0x%x) does not match " 4594 "module version (0x%x).\n", pmc_kernel_version, 4595 PMC_VERSION); 4596 return EPROGMISMATCH; 4597 } 4598 4599 /* 4600 * check sysctl parameters 4601 */ 4602 4603 if (pmc_hashsize <= 0) { 4604 (void) printf("hwpmc: tunable \"hashsize\"=%d must be " 4605 "greater than zero.\n", pmc_hashsize); 4606 pmc_hashsize = PMC_HASH_SIZE; 4607 } 4608 4609 if (pmc_nsamples <= 0 || pmc_nsamples > 65535) { 4610 (void) printf("hwpmc: tunable \"nsamples\"=%d out of " 4611 "range.\n", pmc_nsamples); 4612 pmc_nsamples = PMC_NSAMPLES; 4613 } 4614 4615 if (pmc_callchaindepth <= 0 || 4616 pmc_callchaindepth > PMC_CALLCHAIN_DEPTH_MAX) { 4617 (void) printf("hwpmc: tunable \"callchaindepth\"=%d out of " 4618 "range.\n", pmc_callchaindepth); 4619 pmc_callchaindepth = PMC_CALLCHAIN_DEPTH; 4620 } 4621 4622 md = pmc_md_initialize(); 4623 4624 if (md == NULL) 4625 return (ENOSYS); 4626 4627 KASSERT(md->pmd_nclass >= 1 && md->pmd_npmc >= 1, 4628 ("[pmc,%d] no classes or pmcs", __LINE__)); 4629 4630 /* Compute the map from row-indices to classdep pointers. */ 4631 pmc_rowindex_to_classdep = malloc(sizeof(struct pmc_classdep *) * 4632 md->pmd_npmc, M_PMC, M_WAITOK|M_ZERO); 4633 4634 for (n = 0; n < md->pmd_npmc; n++) 4635 pmc_rowindex_to_classdep[n] = NULL; 4636 for (ri = c = 0; c < md->pmd_nclass; c++) { 4637 pcd = &md->pmd_classdep[c]; 4638 for (n = 0; n < pcd->pcd_num; n++, ri++) 4639 pmc_rowindex_to_classdep[ri] = pcd; 4640 } 4641 4642 KASSERT(ri == md->pmd_npmc, 4643 ("[pmc,%d] npmc miscomputed: ri=%d, md->npmc=%d", __LINE__, 4644 ri, md->pmd_npmc)); 4645 4646 maxcpu = pmc_cpu_max(); 4647 4648 /* allocate space for the per-cpu array */ 4649 pmc_pcpu = malloc(maxcpu * sizeof(struct pmc_cpu *), M_PMC, 4650 M_WAITOK|M_ZERO); 4651 4652 /* per-cpu 'saved values' for managing process-mode PMCs */ 4653 pmc_pcpu_saved = malloc(sizeof(pmc_value_t) * maxcpu * md->pmd_npmc, 4654 M_PMC, M_WAITOK); 4655 4656 /* Perform CPU-dependent initialization. */ 4657 pmc_save_cpu_binding(&pb); 4658 error = 0; 4659 for (cpu = 0; error == 0 && cpu < maxcpu; cpu++) { 4660 if (!pmc_cpu_is_active(cpu)) 4661 continue; 4662 pmc_select_cpu(cpu); 4663 pmc_pcpu[cpu] = malloc(sizeof(struct pmc_cpu) + 4664 md->pmd_npmc * sizeof(struct pmc_hw *), M_PMC, 4665 M_WAITOK|M_ZERO); 4666 if (md->pmd_pcpu_init) 4667 error = md->pmd_pcpu_init(md, cpu); 4668 for (n = 0; error == 0 && n < md->pmd_nclass; n++) 4669 error = md->pmd_classdep[n].pcd_pcpu_init(md, cpu); 4670 } 4671 pmc_restore_cpu_binding(&pb); 4672 4673 if (error) 4674 return (error); 4675 4676 /* allocate space for the sample array */ 4677 for (cpu = 0; cpu < maxcpu; cpu++) { 4678 if (!pmc_cpu_is_active(cpu)) 4679 continue; 4680 4681 sb = malloc(sizeof(struct pmc_samplebuffer) + 4682 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 4683 M_WAITOK|M_ZERO); 4684 sb->ps_read = sb->ps_write = sb->ps_samples; 4685 sb->ps_fence = sb->ps_samples + pmc_nsamples; 4686 4687 KASSERT(pmc_pcpu[cpu] != NULL, 4688 ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu)); 4689 4690 sb->ps_callchains = malloc(pmc_callchaindepth * pmc_nsamples * 4691 sizeof(uintptr_t), M_PMC, M_WAITOK|M_ZERO); 4692 4693 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 4694 ps->ps_pc = sb->ps_callchains + 4695 (n * pmc_callchaindepth); 4696 4697 pmc_pcpu[cpu]->pc_sb = sb; 4698 } 4699 4700 /* allocate space for the row disposition array */ 4701 pmc_pmcdisp = malloc(sizeof(enum pmc_mode) * md->pmd_npmc, 4702 M_PMC, M_WAITOK|M_ZERO); 4703 4704 KASSERT(pmc_pmcdisp != NULL, 4705 ("[pmc,%d] pmcdisp allocation returned NULL", __LINE__)); 4706 4707 /* mark all PMCs as available */ 4708 for (n = 0; n < (int) md->pmd_npmc; n++) 4709 PMC_MARK_ROW_FREE(n); 4710 4711 /* allocate thread hash tables */ 4712 pmc_ownerhash = hashinit(pmc_hashsize, M_PMC, 4713 &pmc_ownerhashmask); 4714 4715 pmc_processhash = hashinit(pmc_hashsize, M_PMC, 4716 &pmc_processhashmask); 4717 mtx_init(&pmc_processhash_mtx, "pmc-process-hash", "pmc-leaf", 4718 MTX_SPIN); 4719 4720 LIST_INIT(&pmc_ss_owners); 4721 pmc_ss_count = 0; 4722 4723 /* allocate a pool of spin mutexes */ 4724 pmc_mtxpool = mtx_pool_create("pmc-leaf", pmc_mtxpool_size, 4725 MTX_SPIN); 4726 4727 PMCDBG(MOD,INI,1, "pmc_ownerhash=%p, mask=0x%lx " 4728 "targethash=%p mask=0x%lx", pmc_ownerhash, pmc_ownerhashmask, 4729 pmc_processhash, pmc_processhashmask); 4730 4731 /* register process {exit,fork,exec} handlers */ 4732 pmc_exit_tag = EVENTHANDLER_REGISTER(process_exit, 4733 pmc_process_exit, NULL, EVENTHANDLER_PRI_ANY); 4734 pmc_fork_tag = EVENTHANDLER_REGISTER(process_fork, 4735 pmc_process_fork, NULL, EVENTHANDLER_PRI_ANY); 4736 4737 /* initialize logging */ 4738 pmclog_initialize(); 4739 4740 /* set hook functions */ 4741 pmc_intr = md->pmd_intr; 4742 pmc_hook = pmc_hook_handler; 4743 4744 if (error == 0) { 4745 printf(PMC_MODULE_NAME ":"); 4746 for (n = 0; n < (int) md->pmd_nclass; n++) { 4747 pcd = &md->pmd_classdep[n]; 4748 printf(" %s/%d/%d/0x%b", 4749 pmc_name_of_pmcclass[pcd->pcd_class], 4750 pcd->pcd_num, 4751 pcd->pcd_width, 4752 pcd->pcd_caps, 4753 "\20" 4754 "\1INT\2USR\3SYS\4EDG\5THR" 4755 "\6REA\7WRI\10INV\11QUA\12PRC" 4756 "\13TAG\14CSC"); 4757 } 4758 printf("\n"); 4759 } 4760 4761 return (error); 4762 } 4763 4764 /* prepare to be unloaded */ 4765 static void 4766 pmc_cleanup(void) 4767 { 4768 int c, cpu; 4769 unsigned int maxcpu; 4770 struct pmc_ownerhash *ph; 4771 struct pmc_owner *po, *tmp; 4772 struct pmc_binding pb; 4773 #ifdef DEBUG 4774 struct pmc_processhash *prh; 4775 #endif 4776 4777 PMCDBG(MOD,INI,0, "%s", "cleanup"); 4778 4779 /* switch off sampling */ 4780 atomic_store_rel_int(&pmc_cpumask, 0); 4781 pmc_intr = NULL; 4782 4783 sx_xlock(&pmc_sx); 4784 if (pmc_hook == NULL) { /* being unloaded already */ 4785 sx_xunlock(&pmc_sx); 4786 return; 4787 } 4788 4789 pmc_hook = NULL; /* prevent new threads from entering module */ 4790 4791 /* deregister event handlers */ 4792 EVENTHANDLER_DEREGISTER(process_fork, pmc_fork_tag); 4793 EVENTHANDLER_DEREGISTER(process_exit, pmc_exit_tag); 4794 4795 /* send SIGBUS to all owner threads, free up allocations */ 4796 if (pmc_ownerhash) 4797 for (ph = pmc_ownerhash; 4798 ph <= &pmc_ownerhash[pmc_ownerhashmask]; 4799 ph++) { 4800 LIST_FOREACH_SAFE(po, ph, po_next, tmp) { 4801 pmc_remove_owner(po); 4802 4803 /* send SIGBUS to owner processes */ 4804 PMCDBG(MOD,INI,2, "cleanup signal proc=%p " 4805 "(%d, %s)", po->po_owner, 4806 po->po_owner->p_pid, 4807 po->po_owner->p_comm); 4808 4809 PROC_LOCK(po->po_owner); 4810 psignal(po->po_owner, SIGBUS); 4811 PROC_UNLOCK(po->po_owner); 4812 4813 pmc_destroy_owner_descriptor(po); 4814 } 4815 } 4816 4817 /* reclaim allocated data structures */ 4818 if (pmc_mtxpool) 4819 mtx_pool_destroy(&pmc_mtxpool); 4820 4821 mtx_destroy(&pmc_processhash_mtx); 4822 if (pmc_processhash) { 4823 #ifdef DEBUG 4824 struct pmc_process *pp; 4825 4826 PMCDBG(MOD,INI,3, "%s", "destroy process hash"); 4827 for (prh = pmc_processhash; 4828 prh <= &pmc_processhash[pmc_processhashmask]; 4829 prh++) 4830 LIST_FOREACH(pp, prh, pp_next) 4831 PMCDBG(MOD,INI,3, "pid=%d", pp->pp_proc->p_pid); 4832 #endif 4833 4834 hashdestroy(pmc_processhash, M_PMC, pmc_processhashmask); 4835 pmc_processhash = NULL; 4836 } 4837 4838 if (pmc_ownerhash) { 4839 PMCDBG(MOD,INI,3, "%s", "destroy owner hash"); 4840 hashdestroy(pmc_ownerhash, M_PMC, pmc_ownerhashmask); 4841 pmc_ownerhash = NULL; 4842 } 4843 4844 KASSERT(LIST_EMPTY(&pmc_ss_owners), 4845 ("[pmc,%d] Global SS owner list not empty", __LINE__)); 4846 KASSERT(pmc_ss_count == 0, 4847 ("[pmc,%d] Global SS count not empty", __LINE__)); 4848 4849 /* do processor and pmc-class dependent cleanup */ 4850 maxcpu = pmc_cpu_max(); 4851 4852 PMCDBG(MOD,INI,3, "%s", "md cleanup"); 4853 if (md) { 4854 pmc_save_cpu_binding(&pb); 4855 for (cpu = 0; cpu < maxcpu; cpu++) { 4856 PMCDBG(MOD,INI,1,"pmc-cleanup cpu=%d pcs=%p", 4857 cpu, pmc_pcpu[cpu]); 4858 if (!pmc_cpu_is_active(cpu) || pmc_pcpu[cpu] == NULL) 4859 continue; 4860 pmc_select_cpu(cpu); 4861 for (c = 0; c < md->pmd_nclass; c++) 4862 md->pmd_classdep[c].pcd_pcpu_fini(md, cpu); 4863 if (md->pmd_pcpu_fini) 4864 md->pmd_pcpu_fini(md, cpu); 4865 } 4866 4867 pmc_md_finalize(md); 4868 4869 free(md, M_PMC); 4870 md = NULL; 4871 pmc_restore_cpu_binding(&pb); 4872 } 4873 4874 /* Free per-cpu descriptors. */ 4875 for (cpu = 0; cpu < maxcpu; cpu++) { 4876 if (!pmc_cpu_is_active(cpu)) 4877 continue; 4878 KASSERT(pmc_pcpu[cpu]->pc_sb != NULL, 4879 ("[pmc,%d] Null cpu sample buffer cpu=%d", __LINE__, 4880 cpu)); 4881 free(pmc_pcpu[cpu]->pc_sb->ps_callchains, M_PMC); 4882 free(pmc_pcpu[cpu]->pc_sb, M_PMC); 4883 free(pmc_pcpu[cpu], M_PMC); 4884 } 4885 4886 free(pmc_pcpu, M_PMC); 4887 pmc_pcpu = NULL; 4888 4889 free(pmc_pcpu_saved, M_PMC); 4890 pmc_pcpu_saved = NULL; 4891 4892 if (pmc_pmcdisp) { 4893 free(pmc_pmcdisp, M_PMC); 4894 pmc_pmcdisp = NULL; 4895 } 4896 4897 if (pmc_rowindex_to_classdep) { 4898 free(pmc_rowindex_to_classdep, M_PMC); 4899 pmc_rowindex_to_classdep = NULL; 4900 } 4901 4902 pmclog_shutdown(); 4903 4904 sx_xunlock(&pmc_sx); /* we are done */ 4905 } 4906 4907 /* 4908 * The function called at load/unload. 4909 */ 4910 4911 static int 4912 load (struct module *module __unused, int cmd, void *arg __unused) 4913 { 4914 int error; 4915 4916 error = 0; 4917 4918 switch (cmd) { 4919 case MOD_LOAD : 4920 /* initialize the subsystem */ 4921 error = pmc_initialize(); 4922 if (error != 0) 4923 break; 4924 PMCDBG(MOD,INI,1, "syscall=%d maxcpu=%d", 4925 pmc_syscall_num, pmc_cpu_max()); 4926 break; 4927 4928 4929 case MOD_UNLOAD : 4930 case MOD_SHUTDOWN: 4931 pmc_cleanup(); 4932 PMCDBG(MOD,INI,1, "%s", "unloaded"); 4933 break; 4934 4935 default : 4936 error = EINVAL; /* XXX should panic(9) */ 4937 break; 4938 } 4939 4940 return error; 4941 } 4942 4943 /* memory pool */ 4944 MALLOC_DEFINE(M_PMC, "pmc", "Memory space for the PMC module"); 4945