1 /*- 2 * Copyright (c) 2003-2008 Joseph Koshy 3 * Copyright (c) 2007 The FreeBSD Foundation 4 * All rights reserved. 5 * 6 * Portions of this software were developed by A. Joseph Koshy under 7 * sponsorship from the FreeBSD Foundation and Google, Inc. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 * 30 */ 31 32 #include <sys/cdefs.h> 33 __FBSDID("$FreeBSD$"); 34 35 #include <sys/param.h> 36 #include <sys/eventhandler.h> 37 #include <sys/jail.h> 38 #include <sys/kernel.h> 39 #include <sys/kthread.h> 40 #include <sys/limits.h> 41 #include <sys/lock.h> 42 #include <sys/malloc.h> 43 #include <sys/module.h> 44 #include <sys/mount.h> 45 #include <sys/mutex.h> 46 #include <sys/pmc.h> 47 #include <sys/pmckern.h> 48 #include <sys/pmclog.h> 49 #include <sys/priv.h> 50 #include <sys/proc.h> 51 #include <sys/queue.h> 52 #include <sys/resourcevar.h> 53 #include <sys/rwlock.h> 54 #include <sys/sched.h> 55 #include <sys/signalvar.h> 56 #include <sys/smp.h> 57 #include <sys/sx.h> 58 #include <sys/sysctl.h> 59 #include <sys/sysent.h> 60 #include <sys/systm.h> 61 #include <sys/vnode.h> 62 63 #include <sys/linker.h> /* needs to be after <sys/malloc.h> */ 64 65 #include <machine/atomic.h> 66 #include <machine/md_var.h> 67 68 #include <vm/vm.h> 69 #include <vm/vm_extern.h> 70 #include <vm/pmap.h> 71 #include <vm/vm_map.h> 72 #include <vm/vm_object.h> 73 74 #include "hwpmc_soft.h" 75 76 /* 77 * Types 78 */ 79 80 enum pmc_flags { 81 PMC_FLAG_NONE = 0x00, /* do nothing */ 82 PMC_FLAG_REMOVE = 0x01, /* atomically remove entry from hash */ 83 PMC_FLAG_ALLOCATE = 0x02, /* add entry to hash if not found */ 84 }; 85 86 /* 87 * The offset in sysent where the syscall is allocated. 88 */ 89 90 static int pmc_syscall_num = NO_SYSCALL; 91 struct pmc_cpu **pmc_pcpu; /* per-cpu state */ 92 pmc_value_t *pmc_pcpu_saved; /* saved PMC values: CSW handling */ 93 94 #define PMC_PCPU_SAVED(C,R) pmc_pcpu_saved[(R) + md->pmd_npmc*(C)] 95 96 struct mtx_pool *pmc_mtxpool; 97 static int *pmc_pmcdisp; /* PMC row dispositions */ 98 99 #define PMC_ROW_DISP_IS_FREE(R) (pmc_pmcdisp[(R)] == 0) 100 #define PMC_ROW_DISP_IS_THREAD(R) (pmc_pmcdisp[(R)] > 0) 101 #define PMC_ROW_DISP_IS_STANDALONE(R) (pmc_pmcdisp[(R)] < 0) 102 103 #define PMC_MARK_ROW_FREE(R) do { \ 104 pmc_pmcdisp[(R)] = 0; \ 105 } while (0) 106 107 #define PMC_MARK_ROW_STANDALONE(R) do { \ 108 KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \ 109 __LINE__)); \ 110 atomic_add_int(&pmc_pmcdisp[(R)], -1); \ 111 KASSERT(pmc_pmcdisp[(R)] >= (-pmc_cpu_max_active()), \ 112 ("[pmc,%d] row disposition error", __LINE__)); \ 113 } while (0) 114 115 #define PMC_UNMARK_ROW_STANDALONE(R) do { \ 116 atomic_add_int(&pmc_pmcdisp[(R)], 1); \ 117 KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \ 118 __LINE__)); \ 119 } while (0) 120 121 #define PMC_MARK_ROW_THREAD(R) do { \ 122 KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \ 123 __LINE__)); \ 124 atomic_add_int(&pmc_pmcdisp[(R)], 1); \ 125 } while (0) 126 127 #define PMC_UNMARK_ROW_THREAD(R) do { \ 128 atomic_add_int(&pmc_pmcdisp[(R)], -1); \ 129 KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \ 130 __LINE__)); \ 131 } while (0) 132 133 134 /* various event handlers */ 135 static eventhandler_tag pmc_exit_tag, pmc_fork_tag, pmc_kld_load_tag, 136 pmc_kld_unload_tag; 137 138 /* Module statistics */ 139 struct pmc_op_getdriverstats pmc_stats; 140 141 /* Machine/processor dependent operations */ 142 static struct pmc_mdep *md; 143 144 /* 145 * Hash tables mapping owner processes and target threads to PMCs. 146 */ 147 148 struct mtx pmc_processhash_mtx; /* spin mutex */ 149 static u_long pmc_processhashmask; 150 static LIST_HEAD(pmc_processhash, pmc_process) *pmc_processhash; 151 152 /* 153 * Hash table of PMC owner descriptors. This table is protected by 154 * the shared PMC "sx" lock. 155 */ 156 157 static u_long pmc_ownerhashmask; 158 static LIST_HEAD(pmc_ownerhash, pmc_owner) *pmc_ownerhash; 159 160 /* 161 * List of PMC owners with system-wide sampling PMCs. 162 */ 163 164 static LIST_HEAD(, pmc_owner) pmc_ss_owners; 165 166 167 /* 168 * A map of row indices to classdep structures. 169 */ 170 static struct pmc_classdep **pmc_rowindex_to_classdep; 171 172 /* 173 * Prototypes 174 */ 175 176 #ifdef DEBUG 177 static int pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS); 178 static int pmc_debugflags_parse(char *newstr, char *fence); 179 #endif 180 181 static int load(struct module *module, int cmd, void *arg); 182 static int pmc_attach_process(struct proc *p, struct pmc *pm); 183 static struct pmc *pmc_allocate_pmc_descriptor(void); 184 static struct pmc_owner *pmc_allocate_owner_descriptor(struct proc *p); 185 static int pmc_attach_one_process(struct proc *p, struct pmc *pm); 186 static int pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, 187 int cpu); 188 static int pmc_can_attach(struct pmc *pm, struct proc *p); 189 static void pmc_capture_user_callchain(int cpu, int soft, struct trapframe *tf); 190 static void pmc_cleanup(void); 191 static int pmc_detach_process(struct proc *p, struct pmc *pm); 192 static int pmc_detach_one_process(struct proc *p, struct pmc *pm, 193 int flags); 194 static void pmc_destroy_owner_descriptor(struct pmc_owner *po); 195 static void pmc_destroy_pmc_descriptor(struct pmc *pm); 196 static struct pmc_owner *pmc_find_owner_descriptor(struct proc *p); 197 static int pmc_find_pmc(pmc_id_t pmcid, struct pmc **pm); 198 static struct pmc *pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, 199 pmc_id_t pmc); 200 static struct pmc_process *pmc_find_process_descriptor(struct proc *p, 201 uint32_t mode); 202 static void pmc_force_context_switch(void); 203 static void pmc_link_target_process(struct pmc *pm, 204 struct pmc_process *pp); 205 static void pmc_log_all_process_mappings(struct pmc_owner *po); 206 static void pmc_log_kernel_mappings(struct pmc *pm); 207 static void pmc_log_process_mappings(struct pmc_owner *po, struct proc *p); 208 static void pmc_maybe_remove_owner(struct pmc_owner *po); 209 static void pmc_process_csw_in(struct thread *td); 210 static void pmc_process_csw_out(struct thread *td); 211 static void pmc_process_exit(void *arg, struct proc *p); 212 static void pmc_process_fork(void *arg, struct proc *p1, 213 struct proc *p2, int n); 214 static void pmc_process_samples(int cpu, int soft); 215 static void pmc_release_pmc_descriptor(struct pmc *pmc); 216 static void pmc_remove_owner(struct pmc_owner *po); 217 static void pmc_remove_process_descriptor(struct pmc_process *pp); 218 static void pmc_restore_cpu_binding(struct pmc_binding *pb); 219 static void pmc_save_cpu_binding(struct pmc_binding *pb); 220 static void pmc_select_cpu(int cpu); 221 static int pmc_start(struct pmc *pm); 222 static int pmc_stop(struct pmc *pm); 223 static int pmc_syscall_handler(struct thread *td, void *syscall_args); 224 static void pmc_unlink_target_process(struct pmc *pmc, 225 struct pmc_process *pp); 226 static int generic_switch_in(struct pmc_cpu *pc, struct pmc_process *pp); 227 static int generic_switch_out(struct pmc_cpu *pc, struct pmc_process *pp); 228 static struct pmc_mdep *pmc_generic_cpu_initialize(void); 229 static void pmc_generic_cpu_finalize(struct pmc_mdep *md); 230 231 /* 232 * Kernel tunables and sysctl(8) interface. 233 */ 234 235 SYSCTL_DECL(_kern_hwpmc); 236 237 static int pmc_callchaindepth = PMC_CALLCHAIN_DEPTH; 238 SYSCTL_INT(_kern_hwpmc, OID_AUTO, callchaindepth, CTLFLAG_RDTUN, 239 &pmc_callchaindepth, 0, "depth of call chain records"); 240 241 #ifdef DEBUG 242 struct pmc_debugflags pmc_debugflags = PMC_DEBUG_DEFAULT_FLAGS; 243 char pmc_debugstr[PMC_DEBUG_STRSIZE]; 244 TUNABLE_STR(PMC_SYSCTL_NAME_PREFIX "debugflags", pmc_debugstr, 245 sizeof(pmc_debugstr)); 246 SYSCTL_PROC(_kern_hwpmc, OID_AUTO, debugflags, 247 CTLTYPE_STRING | CTLFLAG_RWTUN | CTLFLAG_NOFETCH, 248 0, 0, pmc_debugflags_sysctl_handler, "A", "debug flags"); 249 #endif 250 251 /* 252 * kern.hwpmc.hashrows -- determines the number of rows in the 253 * of the hash table used to look up threads 254 */ 255 256 static int pmc_hashsize = PMC_HASH_SIZE; 257 SYSCTL_INT(_kern_hwpmc, OID_AUTO, hashsize, CTLFLAG_RDTUN, 258 &pmc_hashsize, 0, "rows in hash tables"); 259 260 /* 261 * kern.hwpmc.nsamples --- number of PC samples/callchain stacks per CPU 262 */ 263 264 static int pmc_nsamples = PMC_NSAMPLES; 265 SYSCTL_INT(_kern_hwpmc, OID_AUTO, nsamples, CTLFLAG_RDTUN, 266 &pmc_nsamples, 0, "number of PC samples per CPU"); 267 268 269 /* 270 * kern.hwpmc.mtxpoolsize -- number of mutexes in the mutex pool. 271 */ 272 273 static int pmc_mtxpool_size = PMC_MTXPOOL_SIZE; 274 SYSCTL_INT(_kern_hwpmc, OID_AUTO, mtxpoolsize, CTLFLAG_RDTUN, 275 &pmc_mtxpool_size, 0, "size of spin mutex pool"); 276 277 278 /* 279 * security.bsd.unprivileged_syspmcs -- allow non-root processes to 280 * allocate system-wide PMCs. 281 * 282 * Allowing unprivileged processes to allocate system PMCs is convenient 283 * if system-wide measurements need to be taken concurrently with other 284 * per-process measurements. This feature is turned off by default. 285 */ 286 287 static int pmc_unprivileged_syspmcs = 0; 288 SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_syspmcs, CTLFLAG_RWTUN, 289 &pmc_unprivileged_syspmcs, 0, 290 "allow unprivileged process to allocate system PMCs"); 291 292 /* 293 * Hash function. Discard the lower 2 bits of the pointer since 294 * these are always zero for our uses. The hash multiplier is 295 * round((2^LONG_BIT) * ((sqrt(5)-1)/2)). 296 */ 297 298 #if LONG_BIT == 64 299 #define _PMC_HM 11400714819323198486u 300 #elif LONG_BIT == 32 301 #define _PMC_HM 2654435769u 302 #else 303 #error Must know the size of 'long' to compile 304 #endif 305 306 #define PMC_HASH_PTR(P,M) ((((unsigned long) (P) >> 2) * _PMC_HM) & (M)) 307 308 /* 309 * Syscall structures 310 */ 311 312 /* The `sysent' for the new syscall */ 313 static struct sysent pmc_sysent = { 314 2, /* sy_narg */ 315 pmc_syscall_handler /* sy_call */ 316 }; 317 318 static struct syscall_module_data pmc_syscall_mod = { 319 load, 320 NULL, 321 &pmc_syscall_num, 322 &pmc_sysent, 323 { 0, NULL } 324 }; 325 326 static moduledata_t pmc_mod = { 327 PMC_MODULE_NAME, 328 syscall_module_handler, 329 &pmc_syscall_mod 330 }; 331 332 DECLARE_MODULE(pmc, pmc_mod, SI_SUB_SMP, SI_ORDER_ANY); 333 MODULE_VERSION(pmc, PMC_VERSION); 334 335 #ifdef DEBUG 336 enum pmc_dbgparse_state { 337 PMCDS_WS, /* in whitespace */ 338 PMCDS_MAJOR, /* seen a major keyword */ 339 PMCDS_MINOR 340 }; 341 342 static int 343 pmc_debugflags_parse(char *newstr, char *fence) 344 { 345 char c, *p, *q; 346 struct pmc_debugflags *tmpflags; 347 int error, found, *newbits, tmp; 348 size_t kwlen; 349 350 tmpflags = malloc(sizeof(*tmpflags), M_PMC, M_WAITOK|M_ZERO); 351 352 p = newstr; 353 error = 0; 354 355 for (; p < fence && (c = *p); p++) { 356 357 /* skip white space */ 358 if (c == ' ' || c == '\t') 359 continue; 360 361 /* look for a keyword followed by "=" */ 362 for (q = p; p < fence && (c = *p) && c != '='; p++) 363 ; 364 if (c != '=') { 365 error = EINVAL; 366 goto done; 367 } 368 369 kwlen = p - q; 370 newbits = NULL; 371 372 /* lookup flag group name */ 373 #define DBG_SET_FLAG_MAJ(S,F) \ 374 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \ 375 newbits = &tmpflags->pdb_ ## F; 376 377 DBG_SET_FLAG_MAJ("cpu", CPU); 378 DBG_SET_FLAG_MAJ("csw", CSW); 379 DBG_SET_FLAG_MAJ("logging", LOG); 380 DBG_SET_FLAG_MAJ("module", MOD); 381 DBG_SET_FLAG_MAJ("md", MDP); 382 DBG_SET_FLAG_MAJ("owner", OWN); 383 DBG_SET_FLAG_MAJ("pmc", PMC); 384 DBG_SET_FLAG_MAJ("process", PRC); 385 DBG_SET_FLAG_MAJ("sampling", SAM); 386 387 if (newbits == NULL) { 388 error = EINVAL; 389 goto done; 390 } 391 392 p++; /* skip the '=' */ 393 394 /* Now parse the individual flags */ 395 tmp = 0; 396 newflag: 397 for (q = p; p < fence && (c = *p); p++) 398 if (c == ' ' || c == '\t' || c == ',') 399 break; 400 401 /* p == fence or c == ws or c == "," or c == 0 */ 402 403 if ((kwlen = p - q) == 0) { 404 *newbits = tmp; 405 continue; 406 } 407 408 found = 0; 409 #define DBG_SET_FLAG_MIN(S,F) \ 410 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \ 411 tmp |= found = (1 << PMC_DEBUG_MIN_ ## F) 412 413 /* a '*' denotes all possible flags in the group */ 414 if (kwlen == 1 && *q == '*') 415 tmp = found = ~0; 416 /* look for individual flag names */ 417 DBG_SET_FLAG_MIN("allocaterow", ALR); 418 DBG_SET_FLAG_MIN("allocate", ALL); 419 DBG_SET_FLAG_MIN("attach", ATT); 420 DBG_SET_FLAG_MIN("bind", BND); 421 DBG_SET_FLAG_MIN("config", CFG); 422 DBG_SET_FLAG_MIN("exec", EXC); 423 DBG_SET_FLAG_MIN("exit", EXT); 424 DBG_SET_FLAG_MIN("find", FND); 425 DBG_SET_FLAG_MIN("flush", FLS); 426 DBG_SET_FLAG_MIN("fork", FRK); 427 DBG_SET_FLAG_MIN("getbuf", GTB); 428 DBG_SET_FLAG_MIN("hook", PMH); 429 DBG_SET_FLAG_MIN("init", INI); 430 DBG_SET_FLAG_MIN("intr", INT); 431 DBG_SET_FLAG_MIN("linktarget", TLK); 432 DBG_SET_FLAG_MIN("mayberemove", OMR); 433 DBG_SET_FLAG_MIN("ops", OPS); 434 DBG_SET_FLAG_MIN("read", REA); 435 DBG_SET_FLAG_MIN("register", REG); 436 DBG_SET_FLAG_MIN("release", REL); 437 DBG_SET_FLAG_MIN("remove", ORM); 438 DBG_SET_FLAG_MIN("sample", SAM); 439 DBG_SET_FLAG_MIN("scheduleio", SIO); 440 DBG_SET_FLAG_MIN("select", SEL); 441 DBG_SET_FLAG_MIN("signal", SIG); 442 DBG_SET_FLAG_MIN("swi", SWI); 443 DBG_SET_FLAG_MIN("swo", SWO); 444 DBG_SET_FLAG_MIN("start", STA); 445 DBG_SET_FLAG_MIN("stop", STO); 446 DBG_SET_FLAG_MIN("syscall", PMS); 447 DBG_SET_FLAG_MIN("unlinktarget", TUL); 448 DBG_SET_FLAG_MIN("write", WRI); 449 if (found == 0) { 450 /* unrecognized flag name */ 451 error = EINVAL; 452 goto done; 453 } 454 455 if (c == 0 || c == ' ' || c == '\t') { /* end of flag group */ 456 *newbits = tmp; 457 continue; 458 } 459 460 p++; 461 goto newflag; 462 } 463 464 /* save the new flag set */ 465 bcopy(tmpflags, &pmc_debugflags, sizeof(pmc_debugflags)); 466 467 done: 468 free(tmpflags, M_PMC); 469 return error; 470 } 471 472 static int 473 pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS) 474 { 475 char *fence, *newstr; 476 int error; 477 unsigned int n; 478 479 (void) arg1; (void) arg2; /* unused parameters */ 480 481 n = sizeof(pmc_debugstr); 482 newstr = malloc(n, M_PMC, M_WAITOK|M_ZERO); 483 (void) strlcpy(newstr, pmc_debugstr, n); 484 485 error = sysctl_handle_string(oidp, newstr, n, req); 486 487 /* if there is a new string, parse and copy it */ 488 if (error == 0 && req->newptr != NULL) { 489 fence = newstr + (n < req->newlen ? n : req->newlen + 1); 490 if ((error = pmc_debugflags_parse(newstr, fence)) == 0) 491 (void) strlcpy(pmc_debugstr, newstr, 492 sizeof(pmc_debugstr)); 493 } 494 495 free(newstr, M_PMC); 496 497 return error; 498 } 499 #endif 500 501 /* 502 * Map a row index to a classdep structure and return the adjusted row 503 * index for the PMC class index. 504 */ 505 static struct pmc_classdep * 506 pmc_ri_to_classdep(struct pmc_mdep *md, int ri, int *adjri) 507 { 508 struct pmc_classdep *pcd; 509 510 (void) md; 511 512 KASSERT(ri >= 0 && ri < md->pmd_npmc, 513 ("[pmc,%d] illegal row-index %d", __LINE__, ri)); 514 515 pcd = pmc_rowindex_to_classdep[ri]; 516 517 KASSERT(pcd != NULL, 518 ("[pmc,%d] ri %d null pcd", __LINE__, ri)); 519 520 *adjri = ri - pcd->pcd_ri; 521 522 KASSERT(*adjri >= 0 && *adjri < pcd->pcd_num, 523 ("[pmc,%d] adjusted row-index %d", __LINE__, *adjri)); 524 525 return (pcd); 526 } 527 528 /* 529 * Concurrency Control 530 * 531 * The driver manages the following data structures: 532 * 533 * - target process descriptors, one per target process 534 * - owner process descriptors (and attached lists), one per owner process 535 * - lookup hash tables for owner and target processes 536 * - PMC descriptors (and attached lists) 537 * - per-cpu hardware state 538 * - the 'hook' variable through which the kernel calls into 539 * this module 540 * - the machine hardware state (managed by the MD layer) 541 * 542 * These data structures are accessed from: 543 * 544 * - thread context-switch code 545 * - interrupt handlers (possibly on multiple cpus) 546 * - kernel threads on multiple cpus running on behalf of user 547 * processes doing system calls 548 * - this driver's private kernel threads 549 * 550 * = Locks and Locking strategy = 551 * 552 * The driver uses four locking strategies for its operation: 553 * 554 * - The global SX lock "pmc_sx" is used to protect internal 555 * data structures. 556 * 557 * Calls into the module by syscall() start with this lock being 558 * held in exclusive mode. Depending on the requested operation, 559 * the lock may be downgraded to 'shared' mode to allow more 560 * concurrent readers into the module. Calls into the module from 561 * other parts of the kernel acquire the lock in shared mode. 562 * 563 * This SX lock is held in exclusive mode for any operations that 564 * modify the linkages between the driver's internal data structures. 565 * 566 * The 'pmc_hook' function pointer is also protected by this lock. 567 * It is only examined with the sx lock held in exclusive mode. The 568 * kernel module is allowed to be unloaded only with the sx lock held 569 * in exclusive mode. In normal syscall handling, after acquiring the 570 * pmc_sx lock we first check that 'pmc_hook' is non-null before 571 * proceeding. This prevents races between the thread unloading the module 572 * and other threads seeking to use the module. 573 * 574 * - Lookups of target process structures and owner process structures 575 * cannot use the global "pmc_sx" SX lock because these lookups need 576 * to happen during context switches and in other critical sections 577 * where sleeping is not allowed. We protect these lookup tables 578 * with their own private spin-mutexes, "pmc_processhash_mtx" and 579 * "pmc_ownerhash_mtx". 580 * 581 * - Interrupt handlers work in a lock free manner. At interrupt 582 * time, handlers look at the PMC pointer (phw->phw_pmc) configured 583 * when the PMC was started. If this pointer is NULL, the interrupt 584 * is ignored after updating driver statistics. We ensure that this 585 * pointer is set (using an atomic operation if necessary) before the 586 * PMC hardware is started. Conversely, this pointer is unset atomically 587 * only after the PMC hardware is stopped. 588 * 589 * We ensure that everything needed for the operation of an 590 * interrupt handler is available without it needing to acquire any 591 * locks. We also ensure that a PMC's software state is destroyed only 592 * after the PMC is taken off hardware (on all CPUs). 593 * 594 * - Context-switch handling with process-private PMCs needs more 595 * care. 596 * 597 * A given process may be the target of multiple PMCs. For example, 598 * PMCATTACH and PMCDETACH may be requested by a process on one CPU 599 * while the target process is running on another. A PMC could also 600 * be getting released because its owner is exiting. We tackle 601 * these situations in the following manner: 602 * 603 * - each target process structure 'pmc_process' has an array 604 * of 'struct pmc *' pointers, one for each hardware PMC. 605 * 606 * - At context switch IN time, each "target" PMC in RUNNING state 607 * gets started on hardware and a pointer to each PMC is copied into 608 * the per-cpu phw array. The 'runcount' for the PMC is 609 * incremented. 610 * 611 * - At context switch OUT time, all process-virtual PMCs are stopped 612 * on hardware. The saved value is added to the PMCs value field 613 * only if the PMC is in a non-deleted state (the PMCs state could 614 * have changed during the current time slice). 615 * 616 * Note that since in-between a switch IN on a processor and a switch 617 * OUT, the PMC could have been released on another CPU. Therefore 618 * context switch OUT always looks at the hardware state to turn 619 * OFF PMCs and will update a PMC's saved value only if reachable 620 * from the target process record. 621 * 622 * - OP PMCRELEASE could be called on a PMC at any time (the PMC could 623 * be attached to many processes at the time of the call and could 624 * be active on multiple CPUs). 625 * 626 * We prevent further scheduling of the PMC by marking it as in 627 * state 'DELETED'. If the runcount of the PMC is non-zero then 628 * this PMC is currently running on a CPU somewhere. The thread 629 * doing the PMCRELEASE operation waits by repeatedly doing a 630 * pause() till the runcount comes to zero. 631 * 632 * The contents of a PMC descriptor (struct pmc) are protected using 633 * a spin-mutex. In order to save space, we use a mutex pool. 634 * 635 * In terms of lock types used by witness(4), we use: 636 * - Type "pmc-sx", used by the global SX lock. 637 * - Type "pmc-sleep", for sleep mutexes used by logger threads. 638 * - Type "pmc-per-proc", for protecting PMC owner descriptors. 639 * - Type "pmc-leaf", used for all other spin mutexes. 640 */ 641 642 /* 643 * save the cpu binding of the current kthread 644 */ 645 646 static void 647 pmc_save_cpu_binding(struct pmc_binding *pb) 648 { 649 PMCDBG(CPU,BND,2, "%s", "save-cpu"); 650 thread_lock(curthread); 651 pb->pb_bound = sched_is_bound(curthread); 652 pb->pb_cpu = curthread->td_oncpu; 653 thread_unlock(curthread); 654 PMCDBG(CPU,BND,2, "save-cpu cpu=%d", pb->pb_cpu); 655 } 656 657 /* 658 * restore the cpu binding of the current thread 659 */ 660 661 static void 662 pmc_restore_cpu_binding(struct pmc_binding *pb) 663 { 664 PMCDBG(CPU,BND,2, "restore-cpu curcpu=%d restore=%d", 665 curthread->td_oncpu, pb->pb_cpu); 666 thread_lock(curthread); 667 if (pb->pb_bound) 668 sched_bind(curthread, pb->pb_cpu); 669 else 670 sched_unbind(curthread); 671 thread_unlock(curthread); 672 PMCDBG(CPU,BND,2, "%s", "restore-cpu done"); 673 } 674 675 /* 676 * move execution over the specified cpu and bind it there. 677 */ 678 679 static void 680 pmc_select_cpu(int cpu) 681 { 682 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 683 ("[pmc,%d] bad cpu number %d", __LINE__, cpu)); 684 685 /* Never move to an inactive CPU. */ 686 KASSERT(pmc_cpu_is_active(cpu), ("[pmc,%d] selecting inactive " 687 "CPU %d", __LINE__, cpu)); 688 689 PMCDBG(CPU,SEL,2, "select-cpu cpu=%d", cpu); 690 thread_lock(curthread); 691 sched_bind(curthread, cpu); 692 thread_unlock(curthread); 693 694 KASSERT(curthread->td_oncpu == cpu, 695 ("[pmc,%d] CPU not bound [cpu=%d, curr=%d]", __LINE__, 696 cpu, curthread->td_oncpu)); 697 698 PMCDBG(CPU,SEL,2, "select-cpu cpu=%d ok", cpu); 699 } 700 701 /* 702 * Force a context switch. 703 * 704 * We do this by pause'ing for 1 tick -- invoking mi_switch() is not 705 * guaranteed to force a context switch. 706 */ 707 708 static void 709 pmc_force_context_switch(void) 710 { 711 712 pause("pmcctx", 1); 713 } 714 715 /* 716 * Get the file name for an executable. This is a simple wrapper 717 * around vn_fullpath(9). 718 */ 719 720 static void 721 pmc_getfilename(struct vnode *v, char **fullpath, char **freepath) 722 { 723 724 *fullpath = "unknown"; 725 *freepath = NULL; 726 vn_fullpath(curthread, v, fullpath, freepath); 727 } 728 729 /* 730 * remove an process owning PMCs 731 */ 732 733 void 734 pmc_remove_owner(struct pmc_owner *po) 735 { 736 struct pmc *pm, *tmp; 737 738 sx_assert(&pmc_sx, SX_XLOCKED); 739 740 PMCDBG(OWN,ORM,1, "remove-owner po=%p", po); 741 742 /* Remove descriptor from the owner hash table */ 743 LIST_REMOVE(po, po_next); 744 745 /* release all owned PMC descriptors */ 746 LIST_FOREACH_SAFE(pm, &po->po_pmcs, pm_next, tmp) { 747 PMCDBG(OWN,ORM,2, "pmc=%p", pm); 748 KASSERT(pm->pm_owner == po, 749 ("[pmc,%d] owner %p != po %p", __LINE__, pm->pm_owner, po)); 750 751 pmc_release_pmc_descriptor(pm); /* will unlink from the list */ 752 pmc_destroy_pmc_descriptor(pm); 753 } 754 755 KASSERT(po->po_sscount == 0, 756 ("[pmc,%d] SS count not zero", __LINE__)); 757 KASSERT(LIST_EMPTY(&po->po_pmcs), 758 ("[pmc,%d] PMC list not empty", __LINE__)); 759 760 /* de-configure the log file if present */ 761 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 762 pmclog_deconfigure_log(po); 763 } 764 765 /* 766 * remove an owner process record if all conditions are met. 767 */ 768 769 static void 770 pmc_maybe_remove_owner(struct pmc_owner *po) 771 { 772 773 PMCDBG(OWN,OMR,1, "maybe-remove-owner po=%p", po); 774 775 /* 776 * Remove owner record if 777 * - this process does not own any PMCs 778 * - this process has not allocated a system-wide sampling buffer 779 */ 780 781 if (LIST_EMPTY(&po->po_pmcs) && 782 ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0)) { 783 pmc_remove_owner(po); 784 pmc_destroy_owner_descriptor(po); 785 } 786 } 787 788 /* 789 * Add an association between a target process and a PMC. 790 */ 791 792 static void 793 pmc_link_target_process(struct pmc *pm, struct pmc_process *pp) 794 { 795 int ri; 796 struct pmc_target *pt; 797 798 sx_assert(&pmc_sx, SX_XLOCKED); 799 800 KASSERT(pm != NULL && pp != NULL, 801 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 802 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 803 ("[pmc,%d] Attaching a non-process-virtual pmc=%p to pid=%d", 804 __LINE__, pm, pp->pp_proc->p_pid)); 805 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= ((int) md->pmd_npmc - 1), 806 ("[pmc,%d] Illegal reference count %d for process record %p", 807 __LINE__, pp->pp_refcnt, (void *) pp)); 808 809 ri = PMC_TO_ROWINDEX(pm); 810 811 PMCDBG(PRC,TLK,1, "link-target pmc=%p ri=%d pmc-process=%p", 812 pm, ri, pp); 813 814 #ifdef DEBUG 815 LIST_FOREACH(pt, &pm->pm_targets, pt_next) 816 if (pt->pt_process == pp) 817 KASSERT(0, ("[pmc,%d] pp %p already in pmc %p targets", 818 __LINE__, pp, pm)); 819 #endif 820 821 pt = malloc(sizeof(struct pmc_target), M_PMC, M_WAITOK|M_ZERO); 822 pt->pt_process = pp; 823 824 LIST_INSERT_HEAD(&pm->pm_targets, pt, pt_next); 825 826 atomic_store_rel_ptr((uintptr_t *)&pp->pp_pmcs[ri].pp_pmc, 827 (uintptr_t)pm); 828 829 if (pm->pm_owner->po_owner == pp->pp_proc) 830 pm->pm_flags |= PMC_F_ATTACHED_TO_OWNER; 831 832 /* 833 * Initialize the per-process values at this row index. 834 */ 835 pp->pp_pmcs[ri].pp_pmcval = PMC_TO_MODE(pm) == PMC_MODE_TS ? 836 pm->pm_sc.pm_reloadcount : 0; 837 838 pp->pp_refcnt++; 839 840 } 841 842 /* 843 * Removes the association between a target process and a PMC. 844 */ 845 846 static void 847 pmc_unlink_target_process(struct pmc *pm, struct pmc_process *pp) 848 { 849 int ri; 850 struct proc *p; 851 struct pmc_target *ptgt; 852 853 sx_assert(&pmc_sx, SX_XLOCKED); 854 855 KASSERT(pm != NULL && pp != NULL, 856 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 857 858 KASSERT(pp->pp_refcnt >= 1 && pp->pp_refcnt <= (int) md->pmd_npmc, 859 ("[pmc,%d] Illegal ref count %d on process record %p", 860 __LINE__, pp->pp_refcnt, (void *) pp)); 861 862 ri = PMC_TO_ROWINDEX(pm); 863 864 PMCDBG(PRC,TUL,1, "unlink-target pmc=%p ri=%d pmc-process=%p", 865 pm, ri, pp); 866 867 KASSERT(pp->pp_pmcs[ri].pp_pmc == pm, 868 ("[pmc,%d] PMC ri %d mismatch pmc %p pp->[ri] %p", __LINE__, 869 ri, pm, pp->pp_pmcs[ri].pp_pmc)); 870 871 pp->pp_pmcs[ri].pp_pmc = NULL; 872 pp->pp_pmcs[ri].pp_pmcval = (pmc_value_t) 0; 873 874 /* Remove owner-specific flags */ 875 if (pm->pm_owner->po_owner == pp->pp_proc) { 876 pp->pp_flags &= ~PMC_PP_ENABLE_MSR_ACCESS; 877 pm->pm_flags &= ~PMC_F_ATTACHED_TO_OWNER; 878 } 879 880 pp->pp_refcnt--; 881 882 /* Remove the target process from the PMC structure */ 883 LIST_FOREACH(ptgt, &pm->pm_targets, pt_next) 884 if (ptgt->pt_process == pp) 885 break; 886 887 KASSERT(ptgt != NULL, ("[pmc,%d] process %p (pp: %p) not found " 888 "in pmc %p", __LINE__, pp->pp_proc, pp, pm)); 889 890 LIST_REMOVE(ptgt, pt_next); 891 free(ptgt, M_PMC); 892 893 /* if the PMC now lacks targets, send the owner a SIGIO */ 894 if (LIST_EMPTY(&pm->pm_targets)) { 895 p = pm->pm_owner->po_owner; 896 PROC_LOCK(p); 897 kern_psignal(p, SIGIO); 898 PROC_UNLOCK(p); 899 900 PMCDBG(PRC,SIG,2, "signalling proc=%p signal=%d", p, 901 SIGIO); 902 } 903 } 904 905 /* 906 * Check if PMC 'pm' may be attached to target process 't'. 907 */ 908 909 static int 910 pmc_can_attach(struct pmc *pm, struct proc *t) 911 { 912 struct proc *o; /* pmc owner */ 913 struct ucred *oc, *tc; /* owner, target credentials */ 914 int decline_attach, i; 915 916 /* 917 * A PMC's owner can always attach that PMC to itself. 918 */ 919 920 if ((o = pm->pm_owner->po_owner) == t) 921 return 0; 922 923 PROC_LOCK(o); 924 oc = o->p_ucred; 925 crhold(oc); 926 PROC_UNLOCK(o); 927 928 PROC_LOCK(t); 929 tc = t->p_ucred; 930 crhold(tc); 931 PROC_UNLOCK(t); 932 933 /* 934 * The effective uid of the PMC owner should match at least one 935 * of the {effective,real,saved} uids of the target process. 936 */ 937 938 decline_attach = oc->cr_uid != tc->cr_uid && 939 oc->cr_uid != tc->cr_svuid && 940 oc->cr_uid != tc->cr_ruid; 941 942 /* 943 * Every one of the target's group ids, must be in the owner's 944 * group list. 945 */ 946 for (i = 0; !decline_attach && i < tc->cr_ngroups; i++) 947 decline_attach = !groupmember(tc->cr_groups[i], oc); 948 949 /* check the read and saved gids too */ 950 if (decline_attach == 0) 951 decline_attach = !groupmember(tc->cr_rgid, oc) || 952 !groupmember(tc->cr_svgid, oc); 953 954 crfree(tc); 955 crfree(oc); 956 957 return !decline_attach; 958 } 959 960 /* 961 * Attach a process to a PMC. 962 */ 963 964 static int 965 pmc_attach_one_process(struct proc *p, struct pmc *pm) 966 { 967 int ri; 968 char *fullpath, *freepath; 969 struct pmc_process *pp; 970 971 sx_assert(&pmc_sx, SX_XLOCKED); 972 973 PMCDBG(PRC,ATT,2, "attach-one pm=%p ri=%d proc=%p (%d, %s)", pm, 974 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 975 976 /* 977 * Locate the process descriptor corresponding to process 'p', 978 * allocating space as needed. 979 * 980 * Verify that rowindex 'pm_rowindex' is free in the process 981 * descriptor. 982 * 983 * If not, allocate space for a descriptor and link the 984 * process descriptor and PMC. 985 */ 986 ri = PMC_TO_ROWINDEX(pm); 987 988 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_ALLOCATE)) == NULL) 989 return ENOMEM; 990 991 if (pp->pp_pmcs[ri].pp_pmc == pm) /* already present at slot [ri] */ 992 return EEXIST; 993 994 if (pp->pp_pmcs[ri].pp_pmc != NULL) 995 return EBUSY; 996 997 pmc_link_target_process(pm, pp); 998 999 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) && 1000 (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) == 0) 1001 pm->pm_flags |= PMC_F_NEEDS_LOGFILE; 1002 1003 pm->pm_flags |= PMC_F_ATTACH_DONE; /* mark as attached */ 1004 1005 /* issue an attach event to a configured log file */ 1006 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) { 1007 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 1008 if (p->p_flag & P_KTHREAD) { 1009 fullpath = kernelname; 1010 freepath = NULL; 1011 } else 1012 pmclog_process_pmcattach(pm, p->p_pid, fullpath); 1013 if (freepath) 1014 free(freepath, M_TEMP); 1015 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1016 pmc_log_process_mappings(pm->pm_owner, p); 1017 } 1018 /* mark process as using HWPMCs */ 1019 PROC_LOCK(p); 1020 p->p_flag |= P_HWPMC; 1021 PROC_UNLOCK(p); 1022 1023 return 0; 1024 } 1025 1026 /* 1027 * Attach a process and optionally its children 1028 */ 1029 1030 static int 1031 pmc_attach_process(struct proc *p, struct pmc *pm) 1032 { 1033 int error; 1034 struct proc *top; 1035 1036 sx_assert(&pmc_sx, SX_XLOCKED); 1037 1038 PMCDBG(PRC,ATT,1, "attach pm=%p ri=%d proc=%p (%d, %s)", pm, 1039 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1040 1041 1042 /* 1043 * If this PMC successfully allowed a GETMSR operation 1044 * in the past, disallow further ATTACHes. 1045 */ 1046 1047 if ((pm->pm_flags & PMC_PP_ENABLE_MSR_ACCESS) != 0) 1048 return EPERM; 1049 1050 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 1051 return pmc_attach_one_process(p, pm); 1052 1053 /* 1054 * Traverse all child processes, attaching them to 1055 * this PMC. 1056 */ 1057 1058 sx_slock(&proctree_lock); 1059 1060 top = p; 1061 1062 for (;;) { 1063 if ((error = pmc_attach_one_process(p, pm)) != 0) 1064 break; 1065 if (!LIST_EMPTY(&p->p_children)) 1066 p = LIST_FIRST(&p->p_children); 1067 else for (;;) { 1068 if (p == top) 1069 goto done; 1070 if (LIST_NEXT(p, p_sibling)) { 1071 p = LIST_NEXT(p, p_sibling); 1072 break; 1073 } 1074 p = p->p_pptr; 1075 } 1076 } 1077 1078 if (error) 1079 (void) pmc_detach_process(top, pm); 1080 1081 done: 1082 sx_sunlock(&proctree_lock); 1083 return error; 1084 } 1085 1086 /* 1087 * Detach a process from a PMC. If there are no other PMCs tracking 1088 * this process, remove the process structure from its hash table. If 1089 * 'flags' contains PMC_FLAG_REMOVE, then free the process structure. 1090 */ 1091 1092 static int 1093 pmc_detach_one_process(struct proc *p, struct pmc *pm, int flags) 1094 { 1095 int ri; 1096 struct pmc_process *pp; 1097 1098 sx_assert(&pmc_sx, SX_XLOCKED); 1099 1100 KASSERT(pm != NULL, 1101 ("[pmc,%d] null pm pointer", __LINE__)); 1102 1103 ri = PMC_TO_ROWINDEX(pm); 1104 1105 PMCDBG(PRC,ATT,2, "detach-one pm=%p ri=%d proc=%p (%d, %s) flags=0x%x", 1106 pm, ri, p, p->p_pid, p->p_comm, flags); 1107 1108 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) 1109 return ESRCH; 1110 1111 if (pp->pp_pmcs[ri].pp_pmc != pm) 1112 return EINVAL; 1113 1114 pmc_unlink_target_process(pm, pp); 1115 1116 /* Issue a detach entry if a log file is configured */ 1117 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) 1118 pmclog_process_pmcdetach(pm, p->p_pid); 1119 1120 /* 1121 * If there are no PMCs targetting this process, we remove its 1122 * descriptor from the target hash table and unset the P_HWPMC 1123 * flag in the struct proc. 1124 */ 1125 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= (int) md->pmd_npmc, 1126 ("[pmc,%d] Illegal refcnt %d for process struct %p", 1127 __LINE__, pp->pp_refcnt, pp)); 1128 1129 if (pp->pp_refcnt != 0) /* still a target of some PMC */ 1130 return 0; 1131 1132 pmc_remove_process_descriptor(pp); 1133 1134 if (flags & PMC_FLAG_REMOVE) 1135 free(pp, M_PMC); 1136 1137 PROC_LOCK(p); 1138 p->p_flag &= ~P_HWPMC; 1139 PROC_UNLOCK(p); 1140 1141 return 0; 1142 } 1143 1144 /* 1145 * Detach a process and optionally its descendants from a PMC. 1146 */ 1147 1148 static int 1149 pmc_detach_process(struct proc *p, struct pmc *pm) 1150 { 1151 struct proc *top; 1152 1153 sx_assert(&pmc_sx, SX_XLOCKED); 1154 1155 PMCDBG(PRC,ATT,1, "detach pm=%p ri=%d proc=%p (%d, %s)", pm, 1156 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1157 1158 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 1159 return pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); 1160 1161 /* 1162 * Traverse all children, detaching them from this PMC. We 1163 * ignore errors since we could be detaching a PMC from a 1164 * partially attached proc tree. 1165 */ 1166 1167 sx_slock(&proctree_lock); 1168 1169 top = p; 1170 1171 for (;;) { 1172 (void) pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); 1173 1174 if (!LIST_EMPTY(&p->p_children)) 1175 p = LIST_FIRST(&p->p_children); 1176 else for (;;) { 1177 if (p == top) 1178 goto done; 1179 if (LIST_NEXT(p, p_sibling)) { 1180 p = LIST_NEXT(p, p_sibling); 1181 break; 1182 } 1183 p = p->p_pptr; 1184 } 1185 } 1186 1187 done: 1188 sx_sunlock(&proctree_lock); 1189 1190 if (LIST_EMPTY(&pm->pm_targets)) 1191 pm->pm_flags &= ~PMC_F_ATTACH_DONE; 1192 1193 return 0; 1194 } 1195 1196 1197 /* 1198 * Thread context switch IN 1199 */ 1200 1201 static void 1202 pmc_process_csw_in(struct thread *td) 1203 { 1204 int cpu; 1205 unsigned int adjri, ri; 1206 struct pmc *pm; 1207 struct proc *p; 1208 struct pmc_cpu *pc; 1209 struct pmc_hw *phw; 1210 pmc_value_t newvalue; 1211 struct pmc_process *pp; 1212 struct pmc_classdep *pcd; 1213 1214 p = td->td_proc; 1215 1216 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE)) == NULL) 1217 return; 1218 1219 KASSERT(pp->pp_proc == td->td_proc, 1220 ("[pmc,%d] not my thread state", __LINE__)); 1221 1222 critical_enter(); /* no preemption from this point */ 1223 1224 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1225 1226 PMCDBG(CSW,SWI,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1227 p->p_pid, p->p_comm, pp); 1228 1229 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 1230 ("[pmc,%d] wierd CPU id %d", __LINE__, cpu)); 1231 1232 pc = pmc_pcpu[cpu]; 1233 1234 for (ri = 0; ri < md->pmd_npmc; ri++) { 1235 1236 if ((pm = pp->pp_pmcs[ri].pp_pmc) == NULL) 1237 continue; 1238 1239 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 1240 ("[pmc,%d] Target PMC in non-virtual mode (%d)", 1241 __LINE__, PMC_TO_MODE(pm))); 1242 1243 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1244 ("[pmc,%d] Row index mismatch pmc %d != ri %d", 1245 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1246 1247 /* 1248 * Only PMCs that are marked as 'RUNNING' need 1249 * be placed on hardware. 1250 */ 1251 1252 if (pm->pm_state != PMC_STATE_RUNNING) 1253 continue; 1254 1255 /* increment PMC runcount */ 1256 atomic_add_rel_int(&pm->pm_runcount, 1); 1257 1258 /* configure the HWPMC we are going to use. */ 1259 pcd = pmc_ri_to_classdep(md, ri, &adjri); 1260 pcd->pcd_config_pmc(cpu, adjri, pm); 1261 1262 phw = pc->pc_hwpmcs[ri]; 1263 1264 KASSERT(phw != NULL, 1265 ("[pmc,%d] null hw pointer", __LINE__)); 1266 1267 KASSERT(phw->phw_pmc == pm, 1268 ("[pmc,%d] hw->pmc %p != pmc %p", __LINE__, 1269 phw->phw_pmc, pm)); 1270 1271 /* 1272 * Write out saved value and start the PMC. 1273 * 1274 * Sampling PMCs use a per-process value, while 1275 * counting mode PMCs use a per-pmc value that is 1276 * inherited across descendants. 1277 */ 1278 if (PMC_TO_MODE(pm) == PMC_MODE_TS) { 1279 mtx_pool_lock_spin(pmc_mtxpool, pm); 1280 newvalue = PMC_PCPU_SAVED(cpu,ri) = 1281 pp->pp_pmcs[ri].pp_pmcval; 1282 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1283 } else { 1284 KASSERT(PMC_TO_MODE(pm) == PMC_MODE_TC, 1285 ("[pmc,%d] illegal mode=%d", __LINE__, 1286 PMC_TO_MODE(pm))); 1287 mtx_pool_lock_spin(pmc_mtxpool, pm); 1288 newvalue = PMC_PCPU_SAVED(cpu, ri) = 1289 pm->pm_gv.pm_savedvalue; 1290 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1291 } 1292 1293 PMCDBG(CSW,SWI,1,"cpu=%d ri=%d new=%jd", cpu, ri, newvalue); 1294 1295 pcd->pcd_write_pmc(cpu, adjri, newvalue); 1296 pcd->pcd_start_pmc(cpu, adjri); 1297 } 1298 1299 /* 1300 * perform any other architecture/cpu dependent thread 1301 * switch-in actions. 1302 */ 1303 1304 (void) (*md->pmd_switch_in)(pc, pp); 1305 1306 critical_exit(); 1307 1308 } 1309 1310 /* 1311 * Thread context switch OUT. 1312 */ 1313 1314 static void 1315 pmc_process_csw_out(struct thread *td) 1316 { 1317 int cpu; 1318 int64_t tmp; 1319 struct pmc *pm; 1320 struct proc *p; 1321 enum pmc_mode mode; 1322 struct pmc_cpu *pc; 1323 pmc_value_t newvalue; 1324 unsigned int adjri, ri; 1325 struct pmc_process *pp; 1326 struct pmc_classdep *pcd; 1327 1328 1329 /* 1330 * Locate our process descriptor; this may be NULL if 1331 * this process is exiting and we have already removed 1332 * the process from the target process table. 1333 * 1334 * Note that due to kernel preemption, multiple 1335 * context switches may happen while the process is 1336 * exiting. 1337 * 1338 * Note also that if the target process cannot be 1339 * found we still need to deconfigure any PMCs that 1340 * are currently running on hardware. 1341 */ 1342 1343 p = td->td_proc; 1344 pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE); 1345 1346 /* 1347 * save PMCs 1348 */ 1349 1350 critical_enter(); 1351 1352 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1353 1354 PMCDBG(CSW,SWO,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1355 p->p_pid, p->p_comm, pp); 1356 1357 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 1358 ("[pmc,%d wierd CPU id %d", __LINE__, cpu)); 1359 1360 pc = pmc_pcpu[cpu]; 1361 1362 /* 1363 * When a PMC gets unlinked from a target PMC, it will 1364 * be removed from the target's pp_pmc[] array. 1365 * 1366 * However, on a MP system, the target could have been 1367 * executing on another CPU at the time of the unlink. 1368 * So, at context switch OUT time, we need to look at 1369 * the hardware to determine if a PMC is scheduled on 1370 * it. 1371 */ 1372 1373 for (ri = 0; ri < md->pmd_npmc; ri++) { 1374 1375 pcd = pmc_ri_to_classdep(md, ri, &adjri); 1376 pm = NULL; 1377 (void) (*pcd->pcd_get_config)(cpu, adjri, &pm); 1378 1379 if (pm == NULL) /* nothing at this row index */ 1380 continue; 1381 1382 mode = PMC_TO_MODE(pm); 1383 if (!PMC_IS_VIRTUAL_MODE(mode)) 1384 continue; /* not a process virtual PMC */ 1385 1386 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1387 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 1388 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1389 1390 /* Stop hardware if not already stopped */ 1391 if (pm->pm_stalled == 0) 1392 pcd->pcd_stop_pmc(cpu, adjri); 1393 1394 /* reduce this PMC's runcount */ 1395 atomic_subtract_rel_int(&pm->pm_runcount, 1); 1396 1397 /* 1398 * If this PMC is associated with this process, 1399 * save the reading. 1400 */ 1401 1402 if (pp != NULL && pp->pp_pmcs[ri].pp_pmc != NULL) { 1403 1404 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 1405 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", __LINE__, 1406 pm, ri, pp->pp_pmcs[ri].pp_pmc)); 1407 1408 KASSERT(pp->pp_refcnt > 0, 1409 ("[pmc,%d] pp refcnt = %d", __LINE__, 1410 pp->pp_refcnt)); 1411 1412 pcd->pcd_read_pmc(cpu, adjri, &newvalue); 1413 1414 tmp = newvalue - PMC_PCPU_SAVED(cpu,ri); 1415 1416 PMCDBG(CSW,SWO,1,"cpu=%d ri=%d tmp=%jd", cpu, ri, 1417 tmp); 1418 1419 if (mode == PMC_MODE_TS) { 1420 1421 /* 1422 * For sampling process-virtual PMCs, 1423 * we expect the count to be 1424 * decreasing as the 'value' 1425 * programmed into the PMC is the 1426 * number of events to be seen till 1427 * the next sampling interrupt. 1428 */ 1429 if (tmp < 0) 1430 tmp += pm->pm_sc.pm_reloadcount; 1431 mtx_pool_lock_spin(pmc_mtxpool, pm); 1432 pp->pp_pmcs[ri].pp_pmcval -= tmp; 1433 if ((int64_t) pp->pp_pmcs[ri].pp_pmcval < 0) 1434 pp->pp_pmcs[ri].pp_pmcval += 1435 pm->pm_sc.pm_reloadcount; 1436 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1437 1438 } else { 1439 1440 /* 1441 * For counting process-virtual PMCs, 1442 * we expect the count to be 1443 * increasing monotonically, modulo a 64 1444 * bit wraparound. 1445 */ 1446 KASSERT((int64_t) tmp >= 0, 1447 ("[pmc,%d] negative increment cpu=%d " 1448 "ri=%d newvalue=%jx saved=%jx " 1449 "incr=%jx", __LINE__, cpu, ri, 1450 newvalue, PMC_PCPU_SAVED(cpu,ri), tmp)); 1451 1452 mtx_pool_lock_spin(pmc_mtxpool, pm); 1453 pm->pm_gv.pm_savedvalue += tmp; 1454 pp->pp_pmcs[ri].pp_pmcval += tmp; 1455 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1456 1457 if (pm->pm_flags & PMC_F_LOG_PROCCSW) 1458 pmclog_process_proccsw(pm, pp, tmp); 1459 } 1460 } 1461 1462 /* mark hardware as free */ 1463 pcd->pcd_config_pmc(cpu, adjri, NULL); 1464 } 1465 1466 /* 1467 * perform any other architecture/cpu dependent thread 1468 * switch out functions. 1469 */ 1470 1471 (void) (*md->pmd_switch_out)(pc, pp); 1472 1473 critical_exit(); 1474 } 1475 1476 /* 1477 * A mapping change for a process. 1478 */ 1479 1480 static void 1481 pmc_process_mmap(struct thread *td, struct pmckern_map_in *pkm) 1482 { 1483 int ri; 1484 pid_t pid; 1485 char *fullpath, *freepath; 1486 const struct pmc *pm; 1487 struct pmc_owner *po; 1488 const struct pmc_process *pp; 1489 1490 freepath = fullpath = NULL; 1491 pmc_getfilename((struct vnode *) pkm->pm_file, &fullpath, &freepath); 1492 1493 pid = td->td_proc->p_pid; 1494 1495 /* Inform owners of all system-wide sampling PMCs. */ 1496 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1497 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1498 pmclog_process_map_in(po, pid, pkm->pm_address, fullpath); 1499 1500 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1501 goto done; 1502 1503 /* 1504 * Inform sampling PMC owners tracking this process. 1505 */ 1506 for (ri = 0; ri < md->pmd_npmc; ri++) 1507 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1508 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1509 pmclog_process_map_in(pm->pm_owner, 1510 pid, pkm->pm_address, fullpath); 1511 1512 done: 1513 if (freepath) 1514 free(freepath, M_TEMP); 1515 } 1516 1517 1518 /* 1519 * Log an munmap request. 1520 */ 1521 1522 static void 1523 pmc_process_munmap(struct thread *td, struct pmckern_map_out *pkm) 1524 { 1525 int ri; 1526 pid_t pid; 1527 struct pmc_owner *po; 1528 const struct pmc *pm; 1529 const struct pmc_process *pp; 1530 1531 pid = td->td_proc->p_pid; 1532 1533 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1534 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1535 pmclog_process_map_out(po, pid, pkm->pm_address, 1536 pkm->pm_address + pkm->pm_size); 1537 1538 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1539 return; 1540 1541 for (ri = 0; ri < md->pmd_npmc; ri++) 1542 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1543 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1544 pmclog_process_map_out(pm->pm_owner, pid, 1545 pkm->pm_address, pkm->pm_address + pkm->pm_size); 1546 } 1547 1548 /* 1549 * Log mapping information about the kernel. 1550 */ 1551 1552 static void 1553 pmc_log_kernel_mappings(struct pmc *pm) 1554 { 1555 struct pmc_owner *po; 1556 struct pmckern_map_in *km, *kmbase; 1557 1558 sx_assert(&pmc_sx, SX_LOCKED); 1559 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 1560 ("[pmc,%d] non-sampling PMC (%p) desires mapping information", 1561 __LINE__, (void *) pm)); 1562 1563 po = pm->pm_owner; 1564 1565 if (po->po_flags & PMC_PO_INITIAL_MAPPINGS_DONE) 1566 return; 1567 1568 /* 1569 * Log the current set of kernel modules. 1570 */ 1571 kmbase = linker_hwpmc_list_objects(); 1572 for (km = kmbase; km->pm_file != NULL; km++) { 1573 PMCDBG(LOG,REG,1,"%s %p", (char *) km->pm_file, 1574 (void *) km->pm_address); 1575 pmclog_process_map_in(po, (pid_t) -1, km->pm_address, 1576 km->pm_file); 1577 } 1578 free(kmbase, M_LINKER); 1579 1580 po->po_flags |= PMC_PO_INITIAL_MAPPINGS_DONE; 1581 } 1582 1583 /* 1584 * Log the mappings for a single process. 1585 */ 1586 1587 static void 1588 pmc_log_process_mappings(struct pmc_owner *po, struct proc *p) 1589 { 1590 vm_map_t map; 1591 struct vnode *vp; 1592 struct vmspace *vm; 1593 vm_map_entry_t entry; 1594 vm_offset_t last_end; 1595 u_int last_timestamp; 1596 struct vnode *last_vp; 1597 vm_offset_t start_addr; 1598 vm_object_t obj, lobj, tobj; 1599 char *fullpath, *freepath; 1600 1601 last_vp = NULL; 1602 last_end = (vm_offset_t) 0; 1603 fullpath = freepath = NULL; 1604 1605 if ((vm = vmspace_acquire_ref(p)) == NULL) 1606 return; 1607 1608 map = &vm->vm_map; 1609 vm_map_lock_read(map); 1610 1611 for (entry = map->header.next; entry != &map->header; entry = entry->next) { 1612 1613 if (entry == NULL) { 1614 PMCDBG(LOG,OPS,2, "hwpmc: vm_map entry unexpectedly " 1615 "NULL! pid=%d vm_map=%p\n", p->p_pid, map); 1616 break; 1617 } 1618 1619 /* 1620 * We only care about executable map entries. 1621 */ 1622 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) || 1623 !(entry->protection & VM_PROT_EXECUTE) || 1624 (entry->object.vm_object == NULL)) { 1625 continue; 1626 } 1627 1628 obj = entry->object.vm_object; 1629 VM_OBJECT_RLOCK(obj); 1630 1631 /* 1632 * Walk the backing_object list to find the base 1633 * (non-shadowed) vm_object. 1634 */ 1635 for (lobj = tobj = obj; tobj != NULL; tobj = tobj->backing_object) { 1636 if (tobj != obj) 1637 VM_OBJECT_RLOCK(tobj); 1638 if (lobj != obj) 1639 VM_OBJECT_RUNLOCK(lobj); 1640 lobj = tobj; 1641 } 1642 1643 /* 1644 * At this point lobj is the base vm_object and it is locked. 1645 */ 1646 if (lobj == NULL) { 1647 PMCDBG(LOG,OPS,2, "hwpmc: lobj unexpectedly NULL! pid=%d " 1648 "vm_map=%p vm_obj=%p\n", p->p_pid, map, obj); 1649 VM_OBJECT_RUNLOCK(obj); 1650 continue; 1651 } 1652 1653 if (lobj->type != OBJT_VNODE || lobj->handle == NULL) { 1654 if (lobj != obj) 1655 VM_OBJECT_RUNLOCK(lobj); 1656 VM_OBJECT_RUNLOCK(obj); 1657 continue; 1658 } 1659 1660 /* 1661 * Skip contiguous regions that point to the same 1662 * vnode, so we don't emit redundant MAP-IN 1663 * directives. 1664 */ 1665 if (entry->start == last_end && lobj->handle == last_vp) { 1666 last_end = entry->end; 1667 if (lobj != obj) 1668 VM_OBJECT_RUNLOCK(lobj); 1669 VM_OBJECT_RUNLOCK(obj); 1670 continue; 1671 } 1672 1673 /* 1674 * We don't want to keep the proc's vm_map or this 1675 * vm_object locked while we walk the pathname, since 1676 * vn_fullpath() can sleep. However, if we drop the 1677 * lock, it's possible for concurrent activity to 1678 * modify the vm_map list. To protect against this, 1679 * we save the vm_map timestamp before we release the 1680 * lock, and check it after we reacquire the lock 1681 * below. 1682 */ 1683 start_addr = entry->start; 1684 last_end = entry->end; 1685 last_timestamp = map->timestamp; 1686 vm_map_unlock_read(map); 1687 1688 vp = lobj->handle; 1689 vref(vp); 1690 if (lobj != obj) 1691 VM_OBJECT_RUNLOCK(lobj); 1692 1693 VM_OBJECT_RUNLOCK(obj); 1694 1695 freepath = NULL; 1696 pmc_getfilename(vp, &fullpath, &freepath); 1697 last_vp = vp; 1698 1699 vrele(vp); 1700 1701 vp = NULL; 1702 pmclog_process_map_in(po, p->p_pid, start_addr, fullpath); 1703 if (freepath) 1704 free(freepath, M_TEMP); 1705 1706 vm_map_lock_read(map); 1707 1708 /* 1709 * If our saved timestamp doesn't match, this means 1710 * that the vm_map was modified out from under us and 1711 * we can't trust our current "entry" pointer. Do a 1712 * new lookup for this entry. If there is no entry 1713 * for this address range, vm_map_lookup_entry() will 1714 * return the previous one, so we always want to go to 1715 * entry->next on the next loop iteration. 1716 * 1717 * There is an edge condition here that can occur if 1718 * there is no entry at or before this address. In 1719 * this situation, vm_map_lookup_entry returns 1720 * &map->header, which would cause our loop to abort 1721 * without processing the rest of the map. However, 1722 * in practice this will never happen for process 1723 * vm_map. This is because the executable's text 1724 * segment is the first mapping in the proc's address 1725 * space, and this mapping is never removed until the 1726 * process exits, so there will always be a non-header 1727 * entry at or before the requested address for 1728 * vm_map_lookup_entry to return. 1729 */ 1730 if (map->timestamp != last_timestamp) 1731 vm_map_lookup_entry(map, last_end - 1, &entry); 1732 } 1733 1734 vm_map_unlock_read(map); 1735 vmspace_free(vm); 1736 return; 1737 } 1738 1739 /* 1740 * Log mappings for all processes in the system. 1741 */ 1742 1743 static void 1744 pmc_log_all_process_mappings(struct pmc_owner *po) 1745 { 1746 struct proc *p, *top; 1747 1748 sx_assert(&pmc_sx, SX_XLOCKED); 1749 1750 if ((p = pfind(1)) == NULL) 1751 panic("[pmc,%d] Cannot find init", __LINE__); 1752 1753 PROC_UNLOCK(p); 1754 1755 sx_slock(&proctree_lock); 1756 1757 top = p; 1758 1759 for (;;) { 1760 pmc_log_process_mappings(po, p); 1761 if (!LIST_EMPTY(&p->p_children)) 1762 p = LIST_FIRST(&p->p_children); 1763 else for (;;) { 1764 if (p == top) 1765 goto done; 1766 if (LIST_NEXT(p, p_sibling)) { 1767 p = LIST_NEXT(p, p_sibling); 1768 break; 1769 } 1770 p = p->p_pptr; 1771 } 1772 } 1773 done: 1774 sx_sunlock(&proctree_lock); 1775 } 1776 1777 /* 1778 * The 'hook' invoked from the kernel proper 1779 */ 1780 1781 1782 #ifdef DEBUG 1783 const char *pmc_hooknames[] = { 1784 /* these strings correspond to PMC_FN_* in <sys/pmckern.h> */ 1785 "", 1786 "EXEC", 1787 "CSW-IN", 1788 "CSW-OUT", 1789 "SAMPLE", 1790 "UNUSED1", 1791 "UNUSED2", 1792 "MMAP", 1793 "MUNMAP", 1794 "CALLCHAIN-NMI", 1795 "CALLCHAIN-SOFT", 1796 "SOFTSAMPLING" 1797 }; 1798 #endif 1799 1800 static int 1801 pmc_hook_handler(struct thread *td, int function, void *arg) 1802 { 1803 1804 PMCDBG(MOD,PMH,1, "hook td=%p func=%d \"%s\" arg=%p", td, function, 1805 pmc_hooknames[function], arg); 1806 1807 switch (function) 1808 { 1809 1810 /* 1811 * Process exec() 1812 */ 1813 1814 case PMC_FN_PROCESS_EXEC: 1815 { 1816 char *fullpath, *freepath; 1817 unsigned int ri; 1818 int is_using_hwpmcs; 1819 struct pmc *pm; 1820 struct proc *p; 1821 struct pmc_owner *po; 1822 struct pmc_process *pp; 1823 struct pmckern_procexec *pk; 1824 1825 sx_assert(&pmc_sx, SX_XLOCKED); 1826 1827 p = td->td_proc; 1828 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 1829 1830 pk = (struct pmckern_procexec *) arg; 1831 1832 /* Inform owners of SS mode PMCs of the exec event. */ 1833 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1834 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1835 pmclog_process_procexec(po, PMC_ID_INVALID, 1836 p->p_pid, pk->pm_entryaddr, fullpath); 1837 1838 PROC_LOCK(p); 1839 is_using_hwpmcs = p->p_flag & P_HWPMC; 1840 PROC_UNLOCK(p); 1841 1842 if (!is_using_hwpmcs) { 1843 if (freepath) 1844 free(freepath, M_TEMP); 1845 break; 1846 } 1847 1848 /* 1849 * PMCs are not inherited across an exec(): remove any 1850 * PMCs that this process is the owner of. 1851 */ 1852 1853 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 1854 pmc_remove_owner(po); 1855 pmc_destroy_owner_descriptor(po); 1856 } 1857 1858 /* 1859 * If the process being exec'ed is not the target of any 1860 * PMC, we are done. 1861 */ 1862 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) { 1863 if (freepath) 1864 free(freepath, M_TEMP); 1865 break; 1866 } 1867 1868 /* 1869 * Log the exec event to all monitoring owners. Skip 1870 * owners who have already recieved the event because 1871 * they had system sampling PMCs active. 1872 */ 1873 for (ri = 0; ri < md->pmd_npmc; ri++) 1874 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 1875 po = pm->pm_owner; 1876 if (po->po_sscount == 0 && 1877 po->po_flags & PMC_PO_OWNS_LOGFILE) 1878 pmclog_process_procexec(po, pm->pm_id, 1879 p->p_pid, pk->pm_entryaddr, 1880 fullpath); 1881 } 1882 1883 if (freepath) 1884 free(freepath, M_TEMP); 1885 1886 1887 PMCDBG(PRC,EXC,1, "exec proc=%p (%d, %s) cred-changed=%d", 1888 p, p->p_pid, p->p_comm, pk->pm_credentialschanged); 1889 1890 if (pk->pm_credentialschanged == 0) /* no change */ 1891 break; 1892 1893 /* 1894 * If the newly exec()'ed process has a different credential 1895 * than before, allow it to be the target of a PMC only if 1896 * the PMC's owner has sufficient priviledge. 1897 */ 1898 1899 for (ri = 0; ri < md->pmd_npmc; ri++) 1900 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) 1901 if (pmc_can_attach(pm, td->td_proc) != 0) 1902 pmc_detach_one_process(td->td_proc, 1903 pm, PMC_FLAG_NONE); 1904 1905 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= (int) md->pmd_npmc, 1906 ("[pmc,%d] Illegal ref count %d on pp %p", __LINE__, 1907 pp->pp_refcnt, pp)); 1908 1909 /* 1910 * If this process is no longer the target of any 1911 * PMCs, we can remove the process entry and free 1912 * up space. 1913 */ 1914 1915 if (pp->pp_refcnt == 0) { 1916 pmc_remove_process_descriptor(pp); 1917 free(pp, M_PMC); 1918 break; 1919 } 1920 1921 } 1922 break; 1923 1924 case PMC_FN_CSW_IN: 1925 pmc_process_csw_in(td); 1926 break; 1927 1928 case PMC_FN_CSW_OUT: 1929 pmc_process_csw_out(td); 1930 break; 1931 1932 /* 1933 * Process accumulated PC samples. 1934 * 1935 * This function is expected to be called by hardclock() for 1936 * each CPU that has accumulated PC samples. 1937 * 1938 * This function is to be executed on the CPU whose samples 1939 * are being processed. 1940 */ 1941 case PMC_FN_DO_SAMPLES: 1942 1943 /* 1944 * Clear the cpu specific bit in the CPU mask before 1945 * do the rest of the processing. If the NMI handler 1946 * gets invoked after the "atomic_clear_int()" call 1947 * below but before "pmc_process_samples()" gets 1948 * around to processing the interrupt, then we will 1949 * come back here at the next hardclock() tick (and 1950 * may find nothing to do if "pmc_process_samples()" 1951 * had already processed the interrupt). We don't 1952 * lose the interrupt sample. 1953 */ 1954 CPU_CLR_ATOMIC(PCPU_GET(cpuid), &pmc_cpumask); 1955 pmc_process_samples(PCPU_GET(cpuid), PMC_HR); 1956 pmc_process_samples(PCPU_GET(cpuid), PMC_SR); 1957 break; 1958 1959 case PMC_FN_MMAP: 1960 sx_assert(&pmc_sx, SX_LOCKED); 1961 pmc_process_mmap(td, (struct pmckern_map_in *) arg); 1962 break; 1963 1964 case PMC_FN_MUNMAP: 1965 sx_assert(&pmc_sx, SX_LOCKED); 1966 pmc_process_munmap(td, (struct pmckern_map_out *) arg); 1967 break; 1968 1969 case PMC_FN_USER_CALLCHAIN: 1970 /* 1971 * Record a call chain. 1972 */ 1973 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 1974 __LINE__)); 1975 1976 pmc_capture_user_callchain(PCPU_GET(cpuid), PMC_HR, 1977 (struct trapframe *) arg); 1978 td->td_pflags &= ~TDP_CALLCHAIN; 1979 break; 1980 1981 case PMC_FN_USER_CALLCHAIN_SOFT: 1982 /* 1983 * Record a call chain. 1984 */ 1985 KASSERT(td == curthread, ("[pmc,%d] td != curthread", 1986 __LINE__)); 1987 pmc_capture_user_callchain(PCPU_GET(cpuid), PMC_SR, 1988 (struct trapframe *) arg); 1989 td->td_pflags &= ~TDP_CALLCHAIN; 1990 break; 1991 1992 case PMC_FN_SOFT_SAMPLING: 1993 /* 1994 * Call soft PMC sampling intr. 1995 */ 1996 pmc_soft_intr((struct pmckern_soft *) arg); 1997 break; 1998 1999 default: 2000 #ifdef DEBUG 2001 KASSERT(0, ("[pmc,%d] unknown hook %d\n", __LINE__, function)); 2002 #endif 2003 break; 2004 2005 } 2006 2007 return 0; 2008 } 2009 2010 /* 2011 * allocate a 'struct pmc_owner' descriptor in the owner hash table. 2012 */ 2013 2014 static struct pmc_owner * 2015 pmc_allocate_owner_descriptor(struct proc *p) 2016 { 2017 uint32_t hindex; 2018 struct pmc_owner *po; 2019 struct pmc_ownerhash *poh; 2020 2021 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 2022 poh = &pmc_ownerhash[hindex]; 2023 2024 /* allocate space for N pointers and one descriptor struct */ 2025 po = malloc(sizeof(struct pmc_owner), M_PMC, M_WAITOK|M_ZERO); 2026 po->po_owner = p; 2027 LIST_INSERT_HEAD(poh, po, po_next); /* insert into hash table */ 2028 2029 TAILQ_INIT(&po->po_logbuffers); 2030 mtx_init(&po->po_mtx, "pmc-owner-mtx", "pmc-per-proc", MTX_SPIN); 2031 2032 PMCDBG(OWN,ALL,1, "allocate-owner proc=%p (%d, %s) pmc-owner=%p", 2033 p, p->p_pid, p->p_comm, po); 2034 2035 return po; 2036 } 2037 2038 static void 2039 pmc_destroy_owner_descriptor(struct pmc_owner *po) 2040 { 2041 2042 PMCDBG(OWN,REL,1, "destroy-owner po=%p proc=%p (%d, %s)", 2043 po, po->po_owner, po->po_owner->p_pid, po->po_owner->p_comm); 2044 2045 mtx_destroy(&po->po_mtx); 2046 free(po, M_PMC); 2047 } 2048 2049 /* 2050 * find the descriptor corresponding to process 'p', adding or removing it 2051 * as specified by 'mode'. 2052 */ 2053 2054 static struct pmc_process * 2055 pmc_find_process_descriptor(struct proc *p, uint32_t mode) 2056 { 2057 uint32_t hindex; 2058 struct pmc_process *pp, *ppnew; 2059 struct pmc_processhash *pph; 2060 2061 hindex = PMC_HASH_PTR(p, pmc_processhashmask); 2062 pph = &pmc_processhash[hindex]; 2063 2064 ppnew = NULL; 2065 2066 /* 2067 * Pre-allocate memory in the FIND_ALLOCATE case since we 2068 * cannot call malloc(9) once we hold a spin lock. 2069 */ 2070 if (mode & PMC_FLAG_ALLOCATE) 2071 ppnew = malloc(sizeof(struct pmc_process) + md->pmd_npmc * 2072 sizeof(struct pmc_targetstate), M_PMC, M_WAITOK|M_ZERO); 2073 2074 mtx_lock_spin(&pmc_processhash_mtx); 2075 LIST_FOREACH(pp, pph, pp_next) 2076 if (pp->pp_proc == p) 2077 break; 2078 2079 if ((mode & PMC_FLAG_REMOVE) && pp != NULL) 2080 LIST_REMOVE(pp, pp_next); 2081 2082 if ((mode & PMC_FLAG_ALLOCATE) && pp == NULL && 2083 ppnew != NULL) { 2084 ppnew->pp_proc = p; 2085 LIST_INSERT_HEAD(pph, ppnew, pp_next); 2086 pp = ppnew; 2087 ppnew = NULL; 2088 } 2089 mtx_unlock_spin(&pmc_processhash_mtx); 2090 2091 if (pp != NULL && ppnew != NULL) 2092 free(ppnew, M_PMC); 2093 2094 return pp; 2095 } 2096 2097 /* 2098 * remove a process descriptor from the process hash table. 2099 */ 2100 2101 static void 2102 pmc_remove_process_descriptor(struct pmc_process *pp) 2103 { 2104 KASSERT(pp->pp_refcnt == 0, 2105 ("[pmc,%d] Removing process descriptor %p with count %d", 2106 __LINE__, pp, pp->pp_refcnt)); 2107 2108 mtx_lock_spin(&pmc_processhash_mtx); 2109 LIST_REMOVE(pp, pp_next); 2110 mtx_unlock_spin(&pmc_processhash_mtx); 2111 } 2112 2113 2114 /* 2115 * find an owner descriptor corresponding to proc 'p' 2116 */ 2117 2118 static struct pmc_owner * 2119 pmc_find_owner_descriptor(struct proc *p) 2120 { 2121 uint32_t hindex; 2122 struct pmc_owner *po; 2123 struct pmc_ownerhash *poh; 2124 2125 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 2126 poh = &pmc_ownerhash[hindex]; 2127 2128 po = NULL; 2129 LIST_FOREACH(po, poh, po_next) 2130 if (po->po_owner == p) 2131 break; 2132 2133 PMCDBG(OWN,FND,1, "find-owner proc=%p (%d, %s) hindex=0x%x -> " 2134 "pmc-owner=%p", p, p->p_pid, p->p_comm, hindex, po); 2135 2136 return po; 2137 } 2138 2139 /* 2140 * pmc_allocate_pmc_descriptor 2141 * 2142 * Allocate a pmc descriptor and initialize its 2143 * fields. 2144 */ 2145 2146 static struct pmc * 2147 pmc_allocate_pmc_descriptor(void) 2148 { 2149 struct pmc *pmc; 2150 2151 pmc = malloc(sizeof(struct pmc), M_PMC, M_WAITOK|M_ZERO); 2152 2153 PMCDBG(PMC,ALL,1, "allocate-pmc -> pmc=%p", pmc); 2154 2155 return pmc; 2156 } 2157 2158 /* 2159 * Destroy a pmc descriptor. 2160 */ 2161 2162 static void 2163 pmc_destroy_pmc_descriptor(struct pmc *pm) 2164 { 2165 2166 KASSERT(pm->pm_state == PMC_STATE_DELETED || 2167 pm->pm_state == PMC_STATE_FREE, 2168 ("[pmc,%d] destroying non-deleted PMC", __LINE__)); 2169 KASSERT(LIST_EMPTY(&pm->pm_targets), 2170 ("[pmc,%d] destroying pmc with targets", __LINE__)); 2171 KASSERT(pm->pm_owner == NULL, 2172 ("[pmc,%d] destroying pmc attached to an owner", __LINE__)); 2173 KASSERT(pm->pm_runcount == 0, 2174 ("[pmc,%d] pmc has non-zero run count %d", __LINE__, 2175 pm->pm_runcount)); 2176 2177 free(pm, M_PMC); 2178 } 2179 2180 static void 2181 pmc_wait_for_pmc_idle(struct pmc *pm) 2182 { 2183 #ifdef DEBUG 2184 volatile int maxloop; 2185 2186 maxloop = 100 * pmc_cpu_max(); 2187 #endif 2188 /* 2189 * Loop (with a forced context switch) till the PMC's runcount 2190 * comes down to zero. 2191 */ 2192 while (atomic_load_acq_32(&pm->pm_runcount) > 0) { 2193 #ifdef DEBUG 2194 maxloop--; 2195 KASSERT(maxloop > 0, 2196 ("[pmc,%d] (ri%d, rc%d) waiting too long for " 2197 "pmc to be free", __LINE__, 2198 PMC_TO_ROWINDEX(pm), pm->pm_runcount)); 2199 #endif 2200 pmc_force_context_switch(); 2201 } 2202 } 2203 2204 /* 2205 * This function does the following things: 2206 * 2207 * - detaches the PMC from hardware 2208 * - unlinks all target threads that were attached to it 2209 * - removes the PMC from its owner's list 2210 * - destroys the PMC private mutex 2211 * 2212 * Once this function completes, the given pmc pointer can be freed by 2213 * calling pmc_destroy_pmc_descriptor(). 2214 */ 2215 2216 static void 2217 pmc_release_pmc_descriptor(struct pmc *pm) 2218 { 2219 enum pmc_mode mode; 2220 struct pmc_hw *phw; 2221 u_int adjri, ri, cpu; 2222 struct pmc_owner *po; 2223 struct pmc_binding pb; 2224 struct pmc_process *pp; 2225 struct pmc_classdep *pcd; 2226 struct pmc_target *ptgt, *tmp; 2227 2228 sx_assert(&pmc_sx, SX_XLOCKED); 2229 2230 KASSERT(pm, ("[pmc,%d] null pmc", __LINE__)); 2231 2232 ri = PMC_TO_ROWINDEX(pm); 2233 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2234 mode = PMC_TO_MODE(pm); 2235 2236 PMCDBG(PMC,REL,1, "release-pmc pmc=%p ri=%d mode=%d", pm, ri, 2237 mode); 2238 2239 /* 2240 * First, we take the PMC off hardware. 2241 */ 2242 cpu = 0; 2243 if (PMC_IS_SYSTEM_MODE(mode)) { 2244 2245 /* 2246 * A system mode PMC runs on a specific CPU. Switch 2247 * to this CPU and turn hardware off. 2248 */ 2249 pmc_save_cpu_binding(&pb); 2250 2251 cpu = PMC_TO_CPU(pm); 2252 2253 pmc_select_cpu(cpu); 2254 2255 /* switch off non-stalled CPUs */ 2256 if (pm->pm_state == PMC_STATE_RUNNING && 2257 pm->pm_stalled == 0) { 2258 2259 phw = pmc_pcpu[cpu]->pc_hwpmcs[ri]; 2260 2261 KASSERT(phw->phw_pmc == pm, 2262 ("[pmc, %d] pmc ptr ri(%d) hw(%p) pm(%p)", 2263 __LINE__, ri, phw->phw_pmc, pm)); 2264 PMCDBG(PMC,REL,2, "stopping cpu=%d ri=%d", cpu, ri); 2265 2266 critical_enter(); 2267 pcd->pcd_stop_pmc(cpu, adjri); 2268 critical_exit(); 2269 } 2270 2271 PMCDBG(PMC,REL,2, "decfg cpu=%d ri=%d", cpu, ri); 2272 2273 critical_enter(); 2274 pcd->pcd_config_pmc(cpu, adjri, NULL); 2275 critical_exit(); 2276 2277 /* adjust the global and process count of SS mode PMCs */ 2278 if (mode == PMC_MODE_SS && pm->pm_state == PMC_STATE_RUNNING) { 2279 po = pm->pm_owner; 2280 po->po_sscount--; 2281 if (po->po_sscount == 0) { 2282 atomic_subtract_rel_int(&pmc_ss_count, 1); 2283 LIST_REMOVE(po, po_ssnext); 2284 } 2285 } 2286 2287 pm->pm_state = PMC_STATE_DELETED; 2288 2289 pmc_restore_cpu_binding(&pb); 2290 2291 /* 2292 * We could have references to this PMC structure in 2293 * the per-cpu sample queues. Wait for the queue to 2294 * drain. 2295 */ 2296 pmc_wait_for_pmc_idle(pm); 2297 2298 } else if (PMC_IS_VIRTUAL_MODE(mode)) { 2299 2300 /* 2301 * A virtual PMC could be running on multiple CPUs at 2302 * a given instant. 2303 * 2304 * By marking its state as DELETED, we ensure that 2305 * this PMC is never further scheduled on hardware. 2306 * 2307 * Then we wait till all CPUs are done with this PMC. 2308 */ 2309 pm->pm_state = PMC_STATE_DELETED; 2310 2311 2312 /* Wait for the PMCs runcount to come to zero. */ 2313 pmc_wait_for_pmc_idle(pm); 2314 2315 /* 2316 * At this point the PMC is off all CPUs and cannot be 2317 * freshly scheduled onto a CPU. It is now safe to 2318 * unlink all targets from this PMC. If a 2319 * process-record's refcount falls to zero, we remove 2320 * it from the hash table. The module-wide SX lock 2321 * protects us from races. 2322 */ 2323 LIST_FOREACH_SAFE(ptgt, &pm->pm_targets, pt_next, tmp) { 2324 pp = ptgt->pt_process; 2325 pmc_unlink_target_process(pm, pp); /* frees 'ptgt' */ 2326 2327 PMCDBG(PMC,REL,3, "pp->refcnt=%d", pp->pp_refcnt); 2328 2329 /* 2330 * If the target process record shows that no 2331 * PMCs are attached to it, reclaim its space. 2332 */ 2333 2334 if (pp->pp_refcnt == 0) { 2335 pmc_remove_process_descriptor(pp); 2336 free(pp, M_PMC); 2337 } 2338 } 2339 2340 cpu = curthread->td_oncpu; /* setup cpu for pmd_release() */ 2341 2342 } 2343 2344 /* 2345 * Release any MD resources 2346 */ 2347 (void) pcd->pcd_release_pmc(cpu, adjri, pm); 2348 2349 /* 2350 * Update row disposition 2351 */ 2352 2353 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) 2354 PMC_UNMARK_ROW_STANDALONE(ri); 2355 else 2356 PMC_UNMARK_ROW_THREAD(ri); 2357 2358 /* unlink from the owner's list */ 2359 if (pm->pm_owner) { 2360 LIST_REMOVE(pm, pm_next); 2361 pm->pm_owner = NULL; 2362 } 2363 } 2364 2365 /* 2366 * Register an owner and a pmc. 2367 */ 2368 2369 static int 2370 pmc_register_owner(struct proc *p, struct pmc *pmc) 2371 { 2372 struct pmc_owner *po; 2373 2374 sx_assert(&pmc_sx, SX_XLOCKED); 2375 2376 if ((po = pmc_find_owner_descriptor(p)) == NULL) 2377 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) 2378 return ENOMEM; 2379 2380 KASSERT(pmc->pm_owner == NULL, 2381 ("[pmc,%d] attempting to own an initialized PMC", __LINE__)); 2382 pmc->pm_owner = po; 2383 2384 LIST_INSERT_HEAD(&po->po_pmcs, pmc, pm_next); 2385 2386 PROC_LOCK(p); 2387 p->p_flag |= P_HWPMC; 2388 PROC_UNLOCK(p); 2389 2390 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 2391 pmclog_process_pmcallocate(pmc); 2392 2393 PMCDBG(PMC,REG,1, "register-owner pmc-owner=%p pmc=%p", 2394 po, pmc); 2395 2396 return 0; 2397 } 2398 2399 /* 2400 * Return the current row disposition: 2401 * == 0 => FREE 2402 * > 0 => PROCESS MODE 2403 * < 0 => SYSTEM MODE 2404 */ 2405 2406 int 2407 pmc_getrowdisp(int ri) 2408 { 2409 return pmc_pmcdisp[ri]; 2410 } 2411 2412 /* 2413 * Check if a PMC at row index 'ri' can be allocated to the current 2414 * process. 2415 * 2416 * Allocation can fail if: 2417 * - the current process is already being profiled by a PMC at index 'ri', 2418 * attached to it via OP_PMCATTACH. 2419 * - the current process has already allocated a PMC at index 'ri' 2420 * via OP_ALLOCATE. 2421 */ 2422 2423 static int 2424 pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, int cpu) 2425 { 2426 enum pmc_mode mode; 2427 struct pmc *pm; 2428 struct pmc_owner *po; 2429 struct pmc_process *pp; 2430 2431 PMCDBG(PMC,ALR,1, "can-allocate-rowindex proc=%p (%d, %s) ri=%d " 2432 "cpu=%d", p, p->p_pid, p->p_comm, ri, cpu); 2433 2434 /* 2435 * We shouldn't have already allocated a process-mode PMC at 2436 * row index 'ri'. 2437 * 2438 * We shouldn't have allocated a system-wide PMC on the same 2439 * CPU and same RI. 2440 */ 2441 if ((po = pmc_find_owner_descriptor(p)) != NULL) 2442 LIST_FOREACH(pm, &po->po_pmcs, pm_next) { 2443 if (PMC_TO_ROWINDEX(pm) == ri) { 2444 mode = PMC_TO_MODE(pm); 2445 if (PMC_IS_VIRTUAL_MODE(mode)) 2446 return EEXIST; 2447 if (PMC_IS_SYSTEM_MODE(mode) && 2448 (int) PMC_TO_CPU(pm) == cpu) 2449 return EEXIST; 2450 } 2451 } 2452 2453 /* 2454 * We also shouldn't be the target of any PMC at this index 2455 * since otherwise a PMC_ATTACH to ourselves will fail. 2456 */ 2457 if ((pp = pmc_find_process_descriptor(p, 0)) != NULL) 2458 if (pp->pp_pmcs[ri].pp_pmc) 2459 return EEXIST; 2460 2461 PMCDBG(PMC,ALR,2, "can-allocate-rowindex proc=%p (%d, %s) ri=%d ok", 2462 p, p->p_pid, p->p_comm, ri); 2463 2464 return 0; 2465 } 2466 2467 /* 2468 * Check if a given PMC at row index 'ri' can be currently used in 2469 * mode 'mode'. 2470 */ 2471 2472 static int 2473 pmc_can_allocate_row(int ri, enum pmc_mode mode) 2474 { 2475 enum pmc_disp disp; 2476 2477 sx_assert(&pmc_sx, SX_XLOCKED); 2478 2479 PMCDBG(PMC,ALR,1, "can-allocate-row ri=%d mode=%d", ri, mode); 2480 2481 if (PMC_IS_SYSTEM_MODE(mode)) 2482 disp = PMC_DISP_STANDALONE; 2483 else 2484 disp = PMC_DISP_THREAD; 2485 2486 /* 2487 * check disposition for PMC row 'ri': 2488 * 2489 * Expected disposition Row-disposition Result 2490 * 2491 * STANDALONE STANDALONE or FREE proceed 2492 * STANDALONE THREAD fail 2493 * THREAD THREAD or FREE proceed 2494 * THREAD STANDALONE fail 2495 */ 2496 2497 if (!PMC_ROW_DISP_IS_FREE(ri) && 2498 !(disp == PMC_DISP_THREAD && PMC_ROW_DISP_IS_THREAD(ri)) && 2499 !(disp == PMC_DISP_STANDALONE && PMC_ROW_DISP_IS_STANDALONE(ri))) 2500 return EBUSY; 2501 2502 /* 2503 * All OK 2504 */ 2505 2506 PMCDBG(PMC,ALR,2, "can-allocate-row ri=%d mode=%d ok", ri, mode); 2507 2508 return 0; 2509 2510 } 2511 2512 /* 2513 * Find a PMC descriptor with user handle 'pmcid' for thread 'td'. 2514 */ 2515 2516 static struct pmc * 2517 pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, pmc_id_t pmcid) 2518 { 2519 struct pmc *pm; 2520 2521 KASSERT(PMC_ID_TO_ROWINDEX(pmcid) < md->pmd_npmc, 2522 ("[pmc,%d] Illegal pmc index %d (max %d)", __LINE__, 2523 PMC_ID_TO_ROWINDEX(pmcid), md->pmd_npmc)); 2524 2525 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 2526 if (pm->pm_id == pmcid) 2527 return pm; 2528 2529 return NULL; 2530 } 2531 2532 static int 2533 pmc_find_pmc(pmc_id_t pmcid, struct pmc **pmc) 2534 { 2535 2536 struct pmc *pm; 2537 struct pmc_owner *po; 2538 2539 PMCDBG(PMC,FND,1, "find-pmc id=%d", pmcid); 2540 2541 if ((po = pmc_find_owner_descriptor(curthread->td_proc)) == NULL) 2542 return ESRCH; 2543 2544 if ((pm = pmc_find_pmc_descriptor_in_process(po, pmcid)) == NULL) 2545 return EINVAL; 2546 2547 PMCDBG(PMC,FND,2, "find-pmc id=%d -> pmc=%p", pmcid, pm); 2548 2549 *pmc = pm; 2550 return 0; 2551 } 2552 2553 /* 2554 * Start a PMC. 2555 */ 2556 2557 static int 2558 pmc_start(struct pmc *pm) 2559 { 2560 enum pmc_mode mode; 2561 struct pmc_owner *po; 2562 struct pmc_binding pb; 2563 struct pmc_classdep *pcd; 2564 int adjri, error, cpu, ri; 2565 2566 KASSERT(pm != NULL, 2567 ("[pmc,%d] null pm", __LINE__)); 2568 2569 mode = PMC_TO_MODE(pm); 2570 ri = PMC_TO_ROWINDEX(pm); 2571 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2572 2573 error = 0; 2574 2575 PMCDBG(PMC,OPS,1, "start pmc=%p mode=%d ri=%d", pm, mode, ri); 2576 2577 po = pm->pm_owner; 2578 2579 /* 2580 * Disallow PMCSTART if a logfile is required but has not been 2581 * configured yet. 2582 */ 2583 if ((pm->pm_flags & PMC_F_NEEDS_LOGFILE) && 2584 (po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) 2585 return (EDOOFUS); /* programming error */ 2586 2587 /* 2588 * If this is a sampling mode PMC, log mapping information for 2589 * the kernel modules that are currently loaded. 2590 */ 2591 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 2592 pmc_log_kernel_mappings(pm); 2593 2594 if (PMC_IS_VIRTUAL_MODE(mode)) { 2595 2596 /* 2597 * If a PMCATTACH has never been done on this PMC, 2598 * attach it to its owner process. 2599 */ 2600 2601 if (LIST_EMPTY(&pm->pm_targets)) 2602 error = (pm->pm_flags & PMC_F_ATTACH_DONE) ? ESRCH : 2603 pmc_attach_process(po->po_owner, pm); 2604 2605 /* 2606 * If the PMC is attached to its owner, then force a context 2607 * switch to ensure that the MD state gets set correctly. 2608 */ 2609 2610 if (error == 0) { 2611 pm->pm_state = PMC_STATE_RUNNING; 2612 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) 2613 pmc_force_context_switch(); 2614 } 2615 2616 return (error); 2617 } 2618 2619 2620 /* 2621 * A system-wide PMC. 2622 * 2623 * Add the owner to the global list if this is a system-wide 2624 * sampling PMC. 2625 */ 2626 2627 if (mode == PMC_MODE_SS) { 2628 if (po->po_sscount == 0) { 2629 LIST_INSERT_HEAD(&pmc_ss_owners, po, po_ssnext); 2630 atomic_add_rel_int(&pmc_ss_count, 1); 2631 PMCDBG(PMC,OPS,1, "po=%p in global list", po); 2632 } 2633 po->po_sscount++; 2634 2635 /* 2636 * Log mapping information for all existing processes in the 2637 * system. Subsequent mappings are logged as they happen; 2638 * see pmc_process_mmap(). 2639 */ 2640 if (po->po_logprocmaps == 0) { 2641 pmc_log_all_process_mappings(po); 2642 po->po_logprocmaps = 1; 2643 } 2644 } 2645 2646 /* 2647 * Move to the CPU associated with this 2648 * PMC, and start the hardware. 2649 */ 2650 2651 pmc_save_cpu_binding(&pb); 2652 2653 cpu = PMC_TO_CPU(pm); 2654 2655 if (!pmc_cpu_is_active(cpu)) 2656 return (ENXIO); 2657 2658 pmc_select_cpu(cpu); 2659 2660 /* 2661 * global PMCs are configured at allocation time 2662 * so write out the initial value and start the PMC. 2663 */ 2664 2665 pm->pm_state = PMC_STATE_RUNNING; 2666 2667 critical_enter(); 2668 if ((error = pcd->pcd_write_pmc(cpu, adjri, 2669 PMC_IS_SAMPLING_MODE(mode) ? 2670 pm->pm_sc.pm_reloadcount : 2671 pm->pm_sc.pm_initial)) == 0) 2672 error = pcd->pcd_start_pmc(cpu, adjri); 2673 critical_exit(); 2674 2675 pmc_restore_cpu_binding(&pb); 2676 2677 return (error); 2678 } 2679 2680 /* 2681 * Stop a PMC. 2682 */ 2683 2684 static int 2685 pmc_stop(struct pmc *pm) 2686 { 2687 struct pmc_owner *po; 2688 struct pmc_binding pb; 2689 struct pmc_classdep *pcd; 2690 int adjri, cpu, error, ri; 2691 2692 KASSERT(pm != NULL, ("[pmc,%d] null pmc", __LINE__)); 2693 2694 PMCDBG(PMC,OPS,1, "stop pmc=%p mode=%d ri=%d", pm, 2695 PMC_TO_MODE(pm), PMC_TO_ROWINDEX(pm)); 2696 2697 pm->pm_state = PMC_STATE_STOPPED; 2698 2699 /* 2700 * If the PMC is a virtual mode one, changing the state to 2701 * non-RUNNING is enough to ensure that the PMC never gets 2702 * scheduled. 2703 * 2704 * If this PMC is current running on a CPU, then it will 2705 * handled correctly at the time its target process is context 2706 * switched out. 2707 */ 2708 2709 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 2710 return 0; 2711 2712 /* 2713 * A system-mode PMC. Move to the CPU associated with 2714 * this PMC, and stop the hardware. We update the 2715 * 'initial count' so that a subsequent PMCSTART will 2716 * resume counting from the current hardware count. 2717 */ 2718 2719 pmc_save_cpu_binding(&pb); 2720 2721 cpu = PMC_TO_CPU(pm); 2722 2723 KASSERT(cpu >= 0 && cpu < pmc_cpu_max(), 2724 ("[pmc,%d] illegal cpu=%d", __LINE__, cpu)); 2725 2726 if (!pmc_cpu_is_active(cpu)) 2727 return ENXIO; 2728 2729 pmc_select_cpu(cpu); 2730 2731 ri = PMC_TO_ROWINDEX(pm); 2732 pcd = pmc_ri_to_classdep(md, ri, &adjri); 2733 2734 critical_enter(); 2735 if ((error = pcd->pcd_stop_pmc(cpu, adjri)) == 0) 2736 error = pcd->pcd_read_pmc(cpu, adjri, &pm->pm_sc.pm_initial); 2737 critical_exit(); 2738 2739 pmc_restore_cpu_binding(&pb); 2740 2741 po = pm->pm_owner; 2742 2743 /* remove this owner from the global list of SS PMC owners */ 2744 if (PMC_TO_MODE(pm) == PMC_MODE_SS) { 2745 po->po_sscount--; 2746 if (po->po_sscount == 0) { 2747 atomic_subtract_rel_int(&pmc_ss_count, 1); 2748 LIST_REMOVE(po, po_ssnext); 2749 PMCDBG(PMC,OPS,2,"po=%p removed from global list", po); 2750 } 2751 } 2752 2753 return (error); 2754 } 2755 2756 2757 #ifdef DEBUG 2758 static const char *pmc_op_to_name[] = { 2759 #undef __PMC_OP 2760 #define __PMC_OP(N, D) #N , 2761 __PMC_OPS() 2762 NULL 2763 }; 2764 #endif 2765 2766 /* 2767 * The syscall interface 2768 */ 2769 2770 #define PMC_GET_SX_XLOCK(...) do { \ 2771 sx_xlock(&pmc_sx); \ 2772 if (pmc_hook == NULL) { \ 2773 sx_xunlock(&pmc_sx); \ 2774 return __VA_ARGS__; \ 2775 } \ 2776 } while (0) 2777 2778 #define PMC_DOWNGRADE_SX() do { \ 2779 sx_downgrade(&pmc_sx); \ 2780 is_sx_downgraded = 1; \ 2781 } while (0) 2782 2783 static int 2784 pmc_syscall_handler(struct thread *td, void *syscall_args) 2785 { 2786 int error, is_sx_downgraded, is_sx_locked, op; 2787 struct pmc_syscall_args *c; 2788 void *arg; 2789 2790 PMC_GET_SX_XLOCK(ENOSYS); 2791 2792 DROP_GIANT(); 2793 2794 is_sx_downgraded = 0; 2795 is_sx_locked = 1; 2796 2797 c = (struct pmc_syscall_args *) syscall_args; 2798 2799 op = c->pmop_code; 2800 arg = c->pmop_data; 2801 2802 PMCDBG(MOD,PMS,1, "syscall op=%d \"%s\" arg=%p", op, 2803 pmc_op_to_name[op], arg); 2804 2805 error = 0; 2806 atomic_add_int(&pmc_stats.pm_syscalls, 1); 2807 2808 switch(op) 2809 { 2810 2811 2812 /* 2813 * Configure a log file. 2814 * 2815 * XXX This OP will be reworked. 2816 */ 2817 2818 case PMC_OP_CONFIGURELOG: 2819 { 2820 struct proc *p; 2821 struct pmc *pm; 2822 struct pmc_owner *po; 2823 struct pmc_op_configurelog cl; 2824 2825 sx_assert(&pmc_sx, SX_XLOCKED); 2826 2827 if ((error = copyin(arg, &cl, sizeof(cl))) != 0) 2828 break; 2829 2830 /* mark this process as owning a log file */ 2831 p = td->td_proc; 2832 if ((po = pmc_find_owner_descriptor(p)) == NULL) 2833 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) { 2834 error = ENOMEM; 2835 break; 2836 } 2837 2838 /* 2839 * If a valid fd was passed in, try to configure that, 2840 * otherwise if 'fd' was less than zero and there was 2841 * a log file configured, flush its buffers and 2842 * de-configure it. 2843 */ 2844 if (cl.pm_logfd >= 0) { 2845 sx_xunlock(&pmc_sx); 2846 is_sx_locked = 0; 2847 error = pmclog_configure_log(md, po, cl.pm_logfd); 2848 } else if (po->po_flags & PMC_PO_OWNS_LOGFILE) { 2849 pmclog_process_closelog(po); 2850 error = pmclog_close(po); 2851 if (error == 0) { 2852 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 2853 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 2854 pm->pm_state == PMC_STATE_RUNNING) 2855 pmc_stop(pm); 2856 error = pmclog_deconfigure_log(po); 2857 } 2858 } else 2859 error = EINVAL; 2860 2861 if (error) 2862 break; 2863 } 2864 break; 2865 2866 /* 2867 * Flush a log file. 2868 */ 2869 2870 case PMC_OP_FLUSHLOG: 2871 { 2872 struct pmc_owner *po; 2873 2874 sx_assert(&pmc_sx, SX_XLOCKED); 2875 2876 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 2877 error = EINVAL; 2878 break; 2879 } 2880 2881 error = pmclog_flush(po); 2882 } 2883 break; 2884 2885 /* 2886 * Close a log file. 2887 */ 2888 2889 case PMC_OP_CLOSELOG: 2890 { 2891 struct pmc_owner *po; 2892 2893 sx_assert(&pmc_sx, SX_XLOCKED); 2894 2895 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 2896 error = EINVAL; 2897 break; 2898 } 2899 2900 error = pmclog_close(po); 2901 } 2902 break; 2903 2904 /* 2905 * Retrieve hardware configuration. 2906 */ 2907 2908 case PMC_OP_GETCPUINFO: /* CPU information */ 2909 { 2910 struct pmc_op_getcpuinfo gci; 2911 struct pmc_classinfo *pci; 2912 struct pmc_classdep *pcd; 2913 int cl; 2914 2915 gci.pm_cputype = md->pmd_cputype; 2916 gci.pm_ncpu = pmc_cpu_max(); 2917 gci.pm_npmc = md->pmd_npmc; 2918 gci.pm_nclass = md->pmd_nclass; 2919 pci = gci.pm_classes; 2920 pcd = md->pmd_classdep; 2921 for (cl = 0; cl < md->pmd_nclass; cl++, pci++, pcd++) { 2922 pci->pm_caps = pcd->pcd_caps; 2923 pci->pm_class = pcd->pcd_class; 2924 pci->pm_width = pcd->pcd_width; 2925 pci->pm_num = pcd->pcd_num; 2926 } 2927 error = copyout(&gci, arg, sizeof(gci)); 2928 } 2929 break; 2930 2931 /* 2932 * Retrieve soft events list. 2933 */ 2934 case PMC_OP_GETDYNEVENTINFO: 2935 { 2936 enum pmc_class cl; 2937 enum pmc_event ev; 2938 struct pmc_op_getdyneventinfo *gei; 2939 struct pmc_dyn_event_descr dev; 2940 struct pmc_soft *ps; 2941 uint32_t nevent; 2942 2943 sx_assert(&pmc_sx, SX_LOCKED); 2944 2945 gei = (struct pmc_op_getdyneventinfo *) arg; 2946 2947 if ((error = copyin(&gei->pm_class, &cl, sizeof(cl))) != 0) 2948 break; 2949 2950 /* Only SOFT class is dynamic. */ 2951 if (cl != PMC_CLASS_SOFT) { 2952 error = EINVAL; 2953 break; 2954 } 2955 2956 nevent = 0; 2957 for (ev = PMC_EV_SOFT_FIRST; (int)ev <= PMC_EV_SOFT_LAST; ev++) { 2958 ps = pmc_soft_ev_acquire(ev); 2959 if (ps == NULL) 2960 continue; 2961 bcopy(&ps->ps_ev, &dev, sizeof(dev)); 2962 pmc_soft_ev_release(ps); 2963 2964 error = copyout(&dev, 2965 &gei->pm_events[nevent], 2966 sizeof(struct pmc_dyn_event_descr)); 2967 if (error != 0) 2968 break; 2969 nevent++; 2970 } 2971 if (error != 0) 2972 break; 2973 2974 error = copyout(&nevent, &gei->pm_nevent, 2975 sizeof(nevent)); 2976 } 2977 break; 2978 2979 /* 2980 * Get module statistics 2981 */ 2982 2983 case PMC_OP_GETDRIVERSTATS: 2984 { 2985 struct pmc_op_getdriverstats gms; 2986 2987 bcopy(&pmc_stats, &gms, sizeof(gms)); 2988 error = copyout(&gms, arg, sizeof(gms)); 2989 } 2990 break; 2991 2992 2993 /* 2994 * Retrieve module version number 2995 */ 2996 2997 case PMC_OP_GETMODULEVERSION: 2998 { 2999 uint32_t cv, modv; 3000 3001 /* retrieve the client's idea of the ABI version */ 3002 if ((error = copyin(arg, &cv, sizeof(uint32_t))) != 0) 3003 break; 3004 /* don't service clients newer than our driver */ 3005 modv = PMC_VERSION; 3006 if ((cv & 0xFFFF0000) > (modv & 0xFFFF0000)) { 3007 error = EPROGMISMATCH; 3008 break; 3009 } 3010 error = copyout(&modv, arg, sizeof(int)); 3011 } 3012 break; 3013 3014 3015 /* 3016 * Retrieve the state of all the PMCs on a given 3017 * CPU. 3018 */ 3019 3020 case PMC_OP_GETPMCINFO: 3021 { 3022 int ari; 3023 struct pmc *pm; 3024 size_t pmcinfo_size; 3025 uint32_t cpu, n, npmc; 3026 struct pmc_owner *po; 3027 struct pmc_binding pb; 3028 struct pmc_classdep *pcd; 3029 struct pmc_info *p, *pmcinfo; 3030 struct pmc_op_getpmcinfo *gpi; 3031 3032 PMC_DOWNGRADE_SX(); 3033 3034 gpi = (struct pmc_op_getpmcinfo *) arg; 3035 3036 if ((error = copyin(&gpi->pm_cpu, &cpu, sizeof(cpu))) != 0) 3037 break; 3038 3039 if (cpu >= pmc_cpu_max()) { 3040 error = EINVAL; 3041 break; 3042 } 3043 3044 if (!pmc_cpu_is_active(cpu)) { 3045 error = ENXIO; 3046 break; 3047 } 3048 3049 /* switch to CPU 'cpu' */ 3050 pmc_save_cpu_binding(&pb); 3051 pmc_select_cpu(cpu); 3052 3053 npmc = md->pmd_npmc; 3054 3055 pmcinfo_size = npmc * sizeof(struct pmc_info); 3056 pmcinfo = malloc(pmcinfo_size, M_PMC, M_WAITOK); 3057 3058 p = pmcinfo; 3059 3060 for (n = 0; n < md->pmd_npmc; n++, p++) { 3061 3062 pcd = pmc_ri_to_classdep(md, n, &ari); 3063 3064 KASSERT(pcd != NULL, 3065 ("[pmc,%d] null pcd ri=%d", __LINE__, n)); 3066 3067 if ((error = pcd->pcd_describe(cpu, ari, p, &pm)) != 0) 3068 break; 3069 3070 if (PMC_ROW_DISP_IS_STANDALONE(n)) 3071 p->pm_rowdisp = PMC_DISP_STANDALONE; 3072 else if (PMC_ROW_DISP_IS_THREAD(n)) 3073 p->pm_rowdisp = PMC_DISP_THREAD; 3074 else 3075 p->pm_rowdisp = PMC_DISP_FREE; 3076 3077 p->pm_ownerpid = -1; 3078 3079 if (pm == NULL) /* no PMC associated */ 3080 continue; 3081 3082 po = pm->pm_owner; 3083 3084 KASSERT(po->po_owner != NULL, 3085 ("[pmc,%d] pmc_owner had a null proc pointer", 3086 __LINE__)); 3087 3088 p->pm_ownerpid = po->po_owner->p_pid; 3089 p->pm_mode = PMC_TO_MODE(pm); 3090 p->pm_event = pm->pm_event; 3091 p->pm_flags = pm->pm_flags; 3092 3093 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 3094 p->pm_reloadcount = 3095 pm->pm_sc.pm_reloadcount; 3096 } 3097 3098 pmc_restore_cpu_binding(&pb); 3099 3100 /* now copy out the PMC info collected */ 3101 if (error == 0) 3102 error = copyout(pmcinfo, &gpi->pm_pmcs, pmcinfo_size); 3103 3104 free(pmcinfo, M_PMC); 3105 } 3106 break; 3107 3108 3109 /* 3110 * Set the administrative state of a PMC. I.e. whether 3111 * the PMC is to be used or not. 3112 */ 3113 3114 case PMC_OP_PMCADMIN: 3115 { 3116 int cpu, ri; 3117 enum pmc_state request; 3118 struct pmc_cpu *pc; 3119 struct pmc_hw *phw; 3120 struct pmc_op_pmcadmin pma; 3121 struct pmc_binding pb; 3122 3123 sx_assert(&pmc_sx, SX_XLOCKED); 3124 3125 KASSERT(td == curthread, 3126 ("[pmc,%d] td != curthread", __LINE__)); 3127 3128 error = priv_check(td, PRIV_PMC_MANAGE); 3129 if (error) 3130 break; 3131 3132 if ((error = copyin(arg, &pma, sizeof(pma))) != 0) 3133 break; 3134 3135 cpu = pma.pm_cpu; 3136 3137 if (cpu < 0 || cpu >= (int) pmc_cpu_max()) { 3138 error = EINVAL; 3139 break; 3140 } 3141 3142 if (!pmc_cpu_is_active(cpu)) { 3143 error = ENXIO; 3144 break; 3145 } 3146 3147 request = pma.pm_state; 3148 3149 if (request != PMC_STATE_DISABLED && 3150 request != PMC_STATE_FREE) { 3151 error = EINVAL; 3152 break; 3153 } 3154 3155 ri = pma.pm_pmc; /* pmc id == row index */ 3156 if (ri < 0 || ri >= (int) md->pmd_npmc) { 3157 error = EINVAL; 3158 break; 3159 } 3160 3161 /* 3162 * We can't disable a PMC with a row-index allocated 3163 * for process virtual PMCs. 3164 */ 3165 3166 if (PMC_ROW_DISP_IS_THREAD(ri) && 3167 request == PMC_STATE_DISABLED) { 3168 error = EBUSY; 3169 break; 3170 } 3171 3172 /* 3173 * otherwise, this PMC on this CPU is either free or 3174 * in system-wide mode. 3175 */ 3176 3177 pmc_save_cpu_binding(&pb); 3178 pmc_select_cpu(cpu); 3179 3180 pc = pmc_pcpu[cpu]; 3181 phw = pc->pc_hwpmcs[ri]; 3182 3183 /* 3184 * XXX do we need some kind of 'forced' disable? 3185 */ 3186 3187 if (phw->phw_pmc == NULL) { 3188 if (request == PMC_STATE_DISABLED && 3189 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED)) { 3190 phw->phw_state &= ~PMC_PHW_FLAG_IS_ENABLED; 3191 PMC_MARK_ROW_STANDALONE(ri); 3192 } else if (request == PMC_STATE_FREE && 3193 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0) { 3194 phw->phw_state |= PMC_PHW_FLAG_IS_ENABLED; 3195 PMC_UNMARK_ROW_STANDALONE(ri); 3196 } 3197 /* other cases are a no-op */ 3198 } else 3199 error = EBUSY; 3200 3201 pmc_restore_cpu_binding(&pb); 3202 } 3203 break; 3204 3205 3206 /* 3207 * Allocate a PMC. 3208 */ 3209 3210 case PMC_OP_PMCALLOCATE: 3211 { 3212 int adjri, n; 3213 u_int cpu; 3214 uint32_t caps; 3215 struct pmc *pmc; 3216 enum pmc_mode mode; 3217 struct pmc_hw *phw; 3218 struct pmc_binding pb; 3219 struct pmc_classdep *pcd; 3220 struct pmc_op_pmcallocate pa; 3221 3222 if ((error = copyin(arg, &pa, sizeof(pa))) != 0) 3223 break; 3224 3225 caps = pa.pm_caps; 3226 mode = pa.pm_mode; 3227 cpu = pa.pm_cpu; 3228 3229 if ((mode != PMC_MODE_SS && mode != PMC_MODE_SC && 3230 mode != PMC_MODE_TS && mode != PMC_MODE_TC) || 3231 (cpu != (u_int) PMC_CPU_ANY && cpu >= pmc_cpu_max())) { 3232 error = EINVAL; 3233 break; 3234 } 3235 3236 /* 3237 * Virtual PMCs should only ask for a default CPU. 3238 * System mode PMCs need to specify a non-default CPU. 3239 */ 3240 3241 if ((PMC_IS_VIRTUAL_MODE(mode) && cpu != (u_int) PMC_CPU_ANY) || 3242 (PMC_IS_SYSTEM_MODE(mode) && cpu == (u_int) PMC_CPU_ANY)) { 3243 error = EINVAL; 3244 break; 3245 } 3246 3247 /* 3248 * Check that an inactive CPU is not being asked for. 3249 */ 3250 3251 if (PMC_IS_SYSTEM_MODE(mode) && !pmc_cpu_is_active(cpu)) { 3252 error = ENXIO; 3253 break; 3254 } 3255 3256 /* 3257 * Refuse an allocation for a system-wide PMC if this 3258 * process has been jailed, or if this process lacks 3259 * super-user credentials and the sysctl tunable 3260 * 'security.bsd.unprivileged_syspmcs' is zero. 3261 */ 3262 3263 if (PMC_IS_SYSTEM_MODE(mode)) { 3264 if (jailed(curthread->td_ucred)) { 3265 error = EPERM; 3266 break; 3267 } 3268 if (!pmc_unprivileged_syspmcs) { 3269 error = priv_check(curthread, 3270 PRIV_PMC_SYSTEM); 3271 if (error) 3272 break; 3273 } 3274 } 3275 3276 /* 3277 * Look for valid values for 'pm_flags' 3278 */ 3279 3280 if ((pa.pm_flags & ~(PMC_F_DESCENDANTS | PMC_F_LOG_PROCCSW | 3281 PMC_F_LOG_PROCEXIT | PMC_F_CALLCHAIN)) != 0) { 3282 error = EINVAL; 3283 break; 3284 } 3285 3286 /* process logging options are not allowed for system PMCs */ 3287 if (PMC_IS_SYSTEM_MODE(mode) && (pa.pm_flags & 3288 (PMC_F_LOG_PROCCSW | PMC_F_LOG_PROCEXIT))) { 3289 error = EINVAL; 3290 break; 3291 } 3292 3293 /* 3294 * All sampling mode PMCs need to be able to interrupt the 3295 * CPU. 3296 */ 3297 if (PMC_IS_SAMPLING_MODE(mode)) 3298 caps |= PMC_CAP_INTERRUPT; 3299 3300 /* A valid class specifier should have been passed in. */ 3301 for (n = 0; n < md->pmd_nclass; n++) 3302 if (md->pmd_classdep[n].pcd_class == pa.pm_class) 3303 break; 3304 if (n == md->pmd_nclass) { 3305 error = EINVAL; 3306 break; 3307 } 3308 3309 /* The requested PMC capabilities should be feasible. */ 3310 if ((md->pmd_classdep[n].pcd_caps & caps) != caps) { 3311 error = EOPNOTSUPP; 3312 break; 3313 } 3314 3315 PMCDBG(PMC,ALL,2, "event=%d caps=0x%x mode=%d cpu=%d", 3316 pa.pm_ev, caps, mode, cpu); 3317 3318 pmc = pmc_allocate_pmc_descriptor(); 3319 pmc->pm_id = PMC_ID_MAKE_ID(cpu,pa.pm_mode,pa.pm_class, 3320 PMC_ID_INVALID); 3321 pmc->pm_event = pa.pm_ev; 3322 pmc->pm_state = PMC_STATE_FREE; 3323 pmc->pm_caps = caps; 3324 pmc->pm_flags = pa.pm_flags; 3325 3326 /* switch thread to CPU 'cpu' */ 3327 pmc_save_cpu_binding(&pb); 3328 3329 #define PMC_IS_SHAREABLE_PMC(cpu, n) \ 3330 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_state & \ 3331 PMC_PHW_FLAG_IS_SHAREABLE) 3332 #define PMC_IS_UNALLOCATED(cpu, n) \ 3333 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_pmc == NULL) 3334 3335 if (PMC_IS_SYSTEM_MODE(mode)) { 3336 pmc_select_cpu(cpu); 3337 for (n = 0; n < (int) md->pmd_npmc; n++) { 3338 pcd = pmc_ri_to_classdep(md, n, &adjri); 3339 if (pmc_can_allocate_row(n, mode) == 0 && 3340 pmc_can_allocate_rowindex( 3341 curthread->td_proc, n, cpu) == 0 && 3342 (PMC_IS_UNALLOCATED(cpu, n) || 3343 PMC_IS_SHAREABLE_PMC(cpu, n)) && 3344 pcd->pcd_allocate_pmc(cpu, adjri, pmc, 3345 &pa) == 0) 3346 break; 3347 } 3348 } else { 3349 /* Process virtual mode */ 3350 for (n = 0; n < (int) md->pmd_npmc; n++) { 3351 pcd = pmc_ri_to_classdep(md, n, &adjri); 3352 if (pmc_can_allocate_row(n, mode) == 0 && 3353 pmc_can_allocate_rowindex( 3354 curthread->td_proc, n, 3355 PMC_CPU_ANY) == 0 && 3356 pcd->pcd_allocate_pmc(curthread->td_oncpu, 3357 adjri, pmc, &pa) == 0) 3358 break; 3359 } 3360 } 3361 3362 #undef PMC_IS_UNALLOCATED 3363 #undef PMC_IS_SHAREABLE_PMC 3364 3365 pmc_restore_cpu_binding(&pb); 3366 3367 if (n == (int) md->pmd_npmc) { 3368 pmc_destroy_pmc_descriptor(pmc); 3369 pmc = NULL; 3370 error = EINVAL; 3371 break; 3372 } 3373 3374 /* Fill in the correct value in the ID field */ 3375 pmc->pm_id = PMC_ID_MAKE_ID(cpu,mode,pa.pm_class,n); 3376 3377 PMCDBG(PMC,ALL,2, "ev=%d class=%d mode=%d n=%d -> pmcid=%x", 3378 pmc->pm_event, pa.pm_class, mode, n, pmc->pm_id); 3379 3380 /* Process mode PMCs with logging enabled need log files */ 3381 if (pmc->pm_flags & (PMC_F_LOG_PROCEXIT | PMC_F_LOG_PROCCSW)) 3382 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3383 3384 /* All system mode sampling PMCs require a log file */ 3385 if (PMC_IS_SAMPLING_MODE(mode) && PMC_IS_SYSTEM_MODE(mode)) 3386 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3387 3388 /* 3389 * Configure global pmc's immediately 3390 */ 3391 3392 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pmc))) { 3393 3394 pmc_save_cpu_binding(&pb); 3395 pmc_select_cpu(cpu); 3396 3397 phw = pmc_pcpu[cpu]->pc_hwpmcs[n]; 3398 pcd = pmc_ri_to_classdep(md, n, &adjri); 3399 3400 if ((phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0 || 3401 (error = pcd->pcd_config_pmc(cpu, adjri, pmc)) != 0) { 3402 (void) pcd->pcd_release_pmc(cpu, adjri, pmc); 3403 pmc_destroy_pmc_descriptor(pmc); 3404 pmc = NULL; 3405 pmc_restore_cpu_binding(&pb); 3406 error = EPERM; 3407 break; 3408 } 3409 3410 pmc_restore_cpu_binding(&pb); 3411 } 3412 3413 pmc->pm_state = PMC_STATE_ALLOCATED; 3414 3415 /* 3416 * mark row disposition 3417 */ 3418 3419 if (PMC_IS_SYSTEM_MODE(mode)) 3420 PMC_MARK_ROW_STANDALONE(n); 3421 else 3422 PMC_MARK_ROW_THREAD(n); 3423 3424 /* 3425 * Register this PMC with the current thread as its owner. 3426 */ 3427 3428 if ((error = 3429 pmc_register_owner(curthread->td_proc, pmc)) != 0) { 3430 pmc_release_pmc_descriptor(pmc); 3431 pmc_destroy_pmc_descriptor(pmc); 3432 pmc = NULL; 3433 break; 3434 } 3435 3436 /* 3437 * Return the allocated index. 3438 */ 3439 3440 pa.pm_pmcid = pmc->pm_id; 3441 3442 error = copyout(&pa, arg, sizeof(pa)); 3443 } 3444 break; 3445 3446 3447 /* 3448 * Attach a PMC to a process. 3449 */ 3450 3451 case PMC_OP_PMCATTACH: 3452 { 3453 struct pmc *pm; 3454 struct proc *p; 3455 struct pmc_op_pmcattach a; 3456 3457 sx_assert(&pmc_sx, SX_XLOCKED); 3458 3459 if ((error = copyin(arg, &a, sizeof(a))) != 0) 3460 break; 3461 3462 if (a.pm_pid < 0) { 3463 error = EINVAL; 3464 break; 3465 } else if (a.pm_pid == 0) 3466 a.pm_pid = td->td_proc->p_pid; 3467 3468 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 3469 break; 3470 3471 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) { 3472 error = EINVAL; 3473 break; 3474 } 3475 3476 /* PMCs may be (re)attached only when allocated or stopped */ 3477 if (pm->pm_state == PMC_STATE_RUNNING) { 3478 error = EBUSY; 3479 break; 3480 } else if (pm->pm_state != PMC_STATE_ALLOCATED && 3481 pm->pm_state != PMC_STATE_STOPPED) { 3482 error = EINVAL; 3483 break; 3484 } 3485 3486 /* lookup pid */ 3487 if ((p = pfind(a.pm_pid)) == NULL) { 3488 error = ESRCH; 3489 break; 3490 } 3491 3492 /* 3493 * Ignore processes that are working on exiting. 3494 */ 3495 if (p->p_flag & P_WEXIT) { 3496 error = ESRCH; 3497 PROC_UNLOCK(p); /* pfind() returns a locked process */ 3498 break; 3499 } 3500 3501 /* 3502 * we are allowed to attach a PMC to a process if 3503 * we can debug it. 3504 */ 3505 error = p_candebug(curthread, p); 3506 3507 PROC_UNLOCK(p); 3508 3509 if (error == 0) 3510 error = pmc_attach_process(p, pm); 3511 } 3512 break; 3513 3514 3515 /* 3516 * Detach an attached PMC from a process. 3517 */ 3518 3519 case PMC_OP_PMCDETACH: 3520 { 3521 struct pmc *pm; 3522 struct proc *p; 3523 struct pmc_op_pmcattach a; 3524 3525 if ((error = copyin(arg, &a, sizeof(a))) != 0) 3526 break; 3527 3528 if (a.pm_pid < 0) { 3529 error = EINVAL; 3530 break; 3531 } else if (a.pm_pid == 0) 3532 a.pm_pid = td->td_proc->p_pid; 3533 3534 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 3535 break; 3536 3537 if ((p = pfind(a.pm_pid)) == NULL) { 3538 error = ESRCH; 3539 break; 3540 } 3541 3542 /* 3543 * Treat processes that are in the process of exiting 3544 * as if they were not present. 3545 */ 3546 3547 if (p->p_flag & P_WEXIT) 3548 error = ESRCH; 3549 3550 PROC_UNLOCK(p); /* pfind() returns a locked process */ 3551 3552 if (error == 0) 3553 error = pmc_detach_process(p, pm); 3554 } 3555 break; 3556 3557 3558 /* 3559 * Retrieve the MSR number associated with the counter 3560 * 'pmc_id'. This allows processes to directly use RDPMC 3561 * instructions to read their PMCs, without the overhead of a 3562 * system call. 3563 */ 3564 3565 case PMC_OP_PMCGETMSR: 3566 { 3567 int adjri, ri; 3568 struct pmc *pm; 3569 struct pmc_target *pt; 3570 struct pmc_op_getmsr gm; 3571 struct pmc_classdep *pcd; 3572 3573 PMC_DOWNGRADE_SX(); 3574 3575 if ((error = copyin(arg, &gm, sizeof(gm))) != 0) 3576 break; 3577 3578 if ((error = pmc_find_pmc(gm.pm_pmcid, &pm)) != 0) 3579 break; 3580 3581 /* 3582 * The allocated PMC has to be a process virtual PMC, 3583 * i.e., of type MODE_T[CS]. Global PMCs can only be 3584 * read using the PMCREAD operation since they may be 3585 * allocated on a different CPU than the one we could 3586 * be running on at the time of the RDPMC instruction. 3587 * 3588 * The GETMSR operation is not allowed for PMCs that 3589 * are inherited across processes. 3590 */ 3591 3592 if (!PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)) || 3593 (pm->pm_flags & PMC_F_DESCENDANTS)) { 3594 error = EINVAL; 3595 break; 3596 } 3597 3598 /* 3599 * It only makes sense to use a RDPMC (or its 3600 * equivalent instruction on non-x86 architectures) on 3601 * a process that has allocated and attached a PMC to 3602 * itself. Conversely the PMC is only allowed to have 3603 * one process attached to it -- its owner. 3604 */ 3605 3606 if ((pt = LIST_FIRST(&pm->pm_targets)) == NULL || 3607 LIST_NEXT(pt, pt_next) != NULL || 3608 pt->pt_process->pp_proc != pm->pm_owner->po_owner) { 3609 error = EINVAL; 3610 break; 3611 } 3612 3613 ri = PMC_TO_ROWINDEX(pm); 3614 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3615 3616 /* PMC class has no 'GETMSR' support */ 3617 if (pcd->pcd_get_msr == NULL) { 3618 error = ENOSYS; 3619 break; 3620 } 3621 3622 if ((error = (*pcd->pcd_get_msr)(adjri, &gm.pm_msr)) < 0) 3623 break; 3624 3625 if ((error = copyout(&gm, arg, sizeof(gm))) < 0) 3626 break; 3627 3628 /* 3629 * Mark our process as using MSRs. Update machine 3630 * state using a forced context switch. 3631 */ 3632 3633 pt->pt_process->pp_flags |= PMC_PP_ENABLE_MSR_ACCESS; 3634 pmc_force_context_switch(); 3635 3636 } 3637 break; 3638 3639 /* 3640 * Release an allocated PMC 3641 */ 3642 3643 case PMC_OP_PMCRELEASE: 3644 { 3645 pmc_id_t pmcid; 3646 struct pmc *pm; 3647 struct pmc_owner *po; 3648 struct pmc_op_simple sp; 3649 3650 /* 3651 * Find PMC pointer for the named PMC. 3652 * 3653 * Use pmc_release_pmc_descriptor() to switch off the 3654 * PMC, remove all its target threads, and remove the 3655 * PMC from its owner's list. 3656 * 3657 * Remove the owner record if this is the last PMC 3658 * owned. 3659 * 3660 * Free up space. 3661 */ 3662 3663 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3664 break; 3665 3666 pmcid = sp.pm_pmcid; 3667 3668 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3669 break; 3670 3671 po = pm->pm_owner; 3672 pmc_release_pmc_descriptor(pm); 3673 pmc_maybe_remove_owner(po); 3674 pmc_destroy_pmc_descriptor(pm); 3675 } 3676 break; 3677 3678 3679 /* 3680 * Read and/or write a PMC. 3681 */ 3682 3683 case PMC_OP_PMCRW: 3684 { 3685 int adjri; 3686 struct pmc *pm; 3687 uint32_t cpu, ri; 3688 pmc_value_t oldvalue; 3689 struct pmc_binding pb; 3690 struct pmc_op_pmcrw prw; 3691 struct pmc_classdep *pcd; 3692 struct pmc_op_pmcrw *pprw; 3693 3694 PMC_DOWNGRADE_SX(); 3695 3696 if ((error = copyin(arg, &prw, sizeof(prw))) != 0) 3697 break; 3698 3699 ri = 0; 3700 PMCDBG(PMC,OPS,1, "rw id=%d flags=0x%x", prw.pm_pmcid, 3701 prw.pm_flags); 3702 3703 /* must have at least one flag set */ 3704 if ((prw.pm_flags & (PMC_F_OLDVALUE|PMC_F_NEWVALUE)) == 0) { 3705 error = EINVAL; 3706 break; 3707 } 3708 3709 /* locate pmc descriptor */ 3710 if ((error = pmc_find_pmc(prw.pm_pmcid, &pm)) != 0) 3711 break; 3712 3713 /* Can't read a PMC that hasn't been started. */ 3714 if (pm->pm_state != PMC_STATE_ALLOCATED && 3715 pm->pm_state != PMC_STATE_STOPPED && 3716 pm->pm_state != PMC_STATE_RUNNING) { 3717 error = EINVAL; 3718 break; 3719 } 3720 3721 /* writing a new value is allowed only for 'STOPPED' pmcs */ 3722 if (pm->pm_state == PMC_STATE_RUNNING && 3723 (prw.pm_flags & PMC_F_NEWVALUE)) { 3724 error = EBUSY; 3725 break; 3726 } 3727 3728 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) { 3729 3730 /* 3731 * If this PMC is attached to its owner (i.e., 3732 * the process requesting this operation) and 3733 * is running, then attempt to get an 3734 * upto-date reading from hardware for a READ. 3735 * Writes are only allowed when the PMC is 3736 * stopped, so only update the saved value 3737 * field. 3738 * 3739 * If the PMC is not running, or is not 3740 * attached to its owner, read/write to the 3741 * savedvalue field. 3742 */ 3743 3744 ri = PMC_TO_ROWINDEX(pm); 3745 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3746 3747 mtx_pool_lock_spin(pmc_mtxpool, pm); 3748 cpu = curthread->td_oncpu; 3749 3750 if (prw.pm_flags & PMC_F_OLDVALUE) { 3751 if ((pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) && 3752 (pm->pm_state == PMC_STATE_RUNNING)) 3753 error = (*pcd->pcd_read_pmc)(cpu, adjri, 3754 &oldvalue); 3755 else 3756 oldvalue = pm->pm_gv.pm_savedvalue; 3757 } 3758 if (prw.pm_flags & PMC_F_NEWVALUE) 3759 pm->pm_gv.pm_savedvalue = prw.pm_value; 3760 3761 mtx_pool_unlock_spin(pmc_mtxpool, pm); 3762 3763 } else { /* System mode PMCs */ 3764 cpu = PMC_TO_CPU(pm); 3765 ri = PMC_TO_ROWINDEX(pm); 3766 pcd = pmc_ri_to_classdep(md, ri, &adjri); 3767 3768 if (!pmc_cpu_is_active(cpu)) { 3769 error = ENXIO; 3770 break; 3771 } 3772 3773 /* move this thread to CPU 'cpu' */ 3774 pmc_save_cpu_binding(&pb); 3775 pmc_select_cpu(cpu); 3776 3777 critical_enter(); 3778 /* save old value */ 3779 if (prw.pm_flags & PMC_F_OLDVALUE) 3780 if ((error = (*pcd->pcd_read_pmc)(cpu, adjri, 3781 &oldvalue))) 3782 goto error; 3783 /* write out new value */ 3784 if (prw.pm_flags & PMC_F_NEWVALUE) 3785 error = (*pcd->pcd_write_pmc)(cpu, adjri, 3786 prw.pm_value); 3787 error: 3788 critical_exit(); 3789 pmc_restore_cpu_binding(&pb); 3790 if (error) 3791 break; 3792 } 3793 3794 pprw = (struct pmc_op_pmcrw *) arg; 3795 3796 #ifdef DEBUG 3797 if (prw.pm_flags & PMC_F_NEWVALUE) 3798 PMCDBG(PMC,OPS,2, "rw id=%d new %jx -> old %jx", 3799 ri, prw.pm_value, oldvalue); 3800 else if (prw.pm_flags & PMC_F_OLDVALUE) 3801 PMCDBG(PMC,OPS,2, "rw id=%d -> old %jx", ri, oldvalue); 3802 #endif 3803 3804 /* return old value if requested */ 3805 if (prw.pm_flags & PMC_F_OLDVALUE) 3806 if ((error = copyout(&oldvalue, &pprw->pm_value, 3807 sizeof(prw.pm_value)))) 3808 break; 3809 3810 } 3811 break; 3812 3813 3814 /* 3815 * Set the sampling rate for a sampling mode PMC and the 3816 * initial count for a counting mode PMC. 3817 */ 3818 3819 case PMC_OP_PMCSETCOUNT: 3820 { 3821 struct pmc *pm; 3822 struct pmc_op_pmcsetcount sc; 3823 3824 PMC_DOWNGRADE_SX(); 3825 3826 if ((error = copyin(arg, &sc, sizeof(sc))) != 0) 3827 break; 3828 3829 if ((error = pmc_find_pmc(sc.pm_pmcid, &pm)) != 0) 3830 break; 3831 3832 if (pm->pm_state == PMC_STATE_RUNNING) { 3833 error = EBUSY; 3834 break; 3835 } 3836 3837 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 3838 pm->pm_sc.pm_reloadcount = sc.pm_count; 3839 else 3840 pm->pm_sc.pm_initial = sc.pm_count; 3841 } 3842 break; 3843 3844 3845 /* 3846 * Start a PMC. 3847 */ 3848 3849 case PMC_OP_PMCSTART: 3850 { 3851 pmc_id_t pmcid; 3852 struct pmc *pm; 3853 struct pmc_op_simple sp; 3854 3855 sx_assert(&pmc_sx, SX_XLOCKED); 3856 3857 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3858 break; 3859 3860 pmcid = sp.pm_pmcid; 3861 3862 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3863 break; 3864 3865 KASSERT(pmcid == pm->pm_id, 3866 ("[pmc,%d] pmcid %x != id %x", __LINE__, 3867 pm->pm_id, pmcid)); 3868 3869 if (pm->pm_state == PMC_STATE_RUNNING) /* already running */ 3870 break; 3871 else if (pm->pm_state != PMC_STATE_STOPPED && 3872 pm->pm_state != PMC_STATE_ALLOCATED) { 3873 error = EINVAL; 3874 break; 3875 } 3876 3877 error = pmc_start(pm); 3878 } 3879 break; 3880 3881 3882 /* 3883 * Stop a PMC. 3884 */ 3885 3886 case PMC_OP_PMCSTOP: 3887 { 3888 pmc_id_t pmcid; 3889 struct pmc *pm; 3890 struct pmc_op_simple sp; 3891 3892 PMC_DOWNGRADE_SX(); 3893 3894 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3895 break; 3896 3897 pmcid = sp.pm_pmcid; 3898 3899 /* 3900 * Mark the PMC as inactive and invoke the MD stop 3901 * routines if needed. 3902 */ 3903 3904 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3905 break; 3906 3907 KASSERT(pmcid == pm->pm_id, 3908 ("[pmc,%d] pmc id %x != pmcid %x", __LINE__, 3909 pm->pm_id, pmcid)); 3910 3911 if (pm->pm_state == PMC_STATE_STOPPED) /* already stopped */ 3912 break; 3913 else if (pm->pm_state != PMC_STATE_RUNNING) { 3914 error = EINVAL; 3915 break; 3916 } 3917 3918 error = pmc_stop(pm); 3919 } 3920 break; 3921 3922 3923 /* 3924 * Write a user supplied value to the log file. 3925 */ 3926 3927 case PMC_OP_WRITELOG: 3928 { 3929 struct pmc_op_writelog wl; 3930 struct pmc_owner *po; 3931 3932 PMC_DOWNGRADE_SX(); 3933 3934 if ((error = copyin(arg, &wl, sizeof(wl))) != 0) 3935 break; 3936 3937 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 3938 error = EINVAL; 3939 break; 3940 } 3941 3942 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) { 3943 error = EINVAL; 3944 break; 3945 } 3946 3947 error = pmclog_process_userlog(po, &wl); 3948 } 3949 break; 3950 3951 3952 default: 3953 error = EINVAL; 3954 break; 3955 } 3956 3957 if (is_sx_locked != 0) { 3958 if (is_sx_downgraded) 3959 sx_sunlock(&pmc_sx); 3960 else 3961 sx_xunlock(&pmc_sx); 3962 } 3963 3964 if (error) 3965 atomic_add_int(&pmc_stats.pm_syscall_errors, 1); 3966 3967 PICKUP_GIANT(); 3968 3969 return error; 3970 } 3971 3972 /* 3973 * Helper functions 3974 */ 3975 3976 3977 /* 3978 * Mark the thread as needing callchain capture and post an AST. The 3979 * actual callchain capture will be done in a context where it is safe 3980 * to take page faults. 3981 */ 3982 3983 static void 3984 pmc_post_callchain_callback(void) 3985 { 3986 struct thread *td; 3987 3988 td = curthread; 3989 3990 /* 3991 * If there is multiple PMCs for the same interrupt ignore new post 3992 */ 3993 if (td->td_pflags & TDP_CALLCHAIN) 3994 return; 3995 3996 /* 3997 * Mark this thread as needing callchain capture. 3998 * `td->td_pflags' will be safe to touch because this thread 3999 * was in user space when it was interrupted. 4000 */ 4001 td->td_pflags |= TDP_CALLCHAIN; 4002 4003 /* 4004 * Don't let this thread migrate between CPUs until callchain 4005 * capture completes. 4006 */ 4007 sched_pin(); 4008 4009 return; 4010 } 4011 4012 /* 4013 * Interrupt processing. 4014 * 4015 * Find a free slot in the per-cpu array of samples and capture the 4016 * current callchain there. If a sample was successfully added, a bit 4017 * is set in mask 'pmc_cpumask' denoting that the DO_SAMPLES hook 4018 * needs to be invoked from the clock handler. 4019 * 4020 * This function is meant to be called from an NMI handler. It cannot 4021 * use any of the locking primitives supplied by the OS. 4022 */ 4023 4024 int 4025 pmc_process_interrupt(int cpu, int ring, struct pmc *pm, struct trapframe *tf, 4026 int inuserspace) 4027 { 4028 int error, callchaindepth; 4029 struct thread *td; 4030 struct pmc_sample *ps; 4031 struct pmc_samplebuffer *psb; 4032 4033 error = 0; 4034 4035 /* 4036 * Allocate space for a sample buffer. 4037 */ 4038 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4039 4040 ps = psb->ps_write; 4041 if (ps->ps_nsamples) { /* in use, reader hasn't caught up */ 4042 pm->pm_stalled = 1; 4043 atomic_add_int(&pmc_stats.pm_intr_bufferfull, 1); 4044 PMCDBG(SAM,INT,1,"(spc) cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", 4045 cpu, pm, (void *) tf, inuserspace, 4046 (int) (psb->ps_write - psb->ps_samples), 4047 (int) (psb->ps_read - psb->ps_samples)); 4048 error = ENOMEM; 4049 goto done; 4050 } 4051 4052 4053 /* Fill in entry. */ 4054 PMCDBG(SAM,INT,1,"cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", cpu, pm, 4055 (void *) tf, inuserspace, 4056 (int) (psb->ps_write - psb->ps_samples), 4057 (int) (psb->ps_read - psb->ps_samples)); 4058 4059 KASSERT(pm->pm_runcount >= 0, 4060 ("[pmc,%d] pm=%p runcount %d", __LINE__, (void *) pm, 4061 pm->pm_runcount)); 4062 4063 atomic_add_rel_int(&pm->pm_runcount, 1); /* hold onto PMC */ 4064 4065 ps->ps_pmc = pm; 4066 if ((td = curthread) && td->td_proc) 4067 ps->ps_pid = td->td_proc->p_pid; 4068 else 4069 ps->ps_pid = -1; 4070 ps->ps_cpu = cpu; 4071 ps->ps_td = td; 4072 ps->ps_flags = inuserspace ? PMC_CC_F_USERSPACE : 0; 4073 4074 callchaindepth = (pm->pm_flags & PMC_F_CALLCHAIN) ? 4075 pmc_callchaindepth : 1; 4076 4077 if (callchaindepth == 1) 4078 ps->ps_pc[0] = PMC_TRAPFRAME_TO_PC(tf); 4079 else { 4080 /* 4081 * Kernel stack traversals can be done immediately, 4082 * while we defer to an AST for user space traversals. 4083 */ 4084 if (!inuserspace) { 4085 callchaindepth = 4086 pmc_save_kernel_callchain(ps->ps_pc, 4087 callchaindepth, tf); 4088 } else { 4089 pmc_post_callchain_callback(); 4090 callchaindepth = PMC_SAMPLE_INUSE; 4091 } 4092 } 4093 4094 ps->ps_nsamples = callchaindepth; /* mark entry as in use */ 4095 4096 /* increment write pointer, modulo ring buffer size */ 4097 ps++; 4098 if (ps == psb->ps_fence) 4099 psb->ps_write = psb->ps_samples; 4100 else 4101 psb->ps_write = ps; 4102 4103 done: 4104 /* mark CPU as needing processing */ 4105 CPU_SET_ATOMIC(cpu, &pmc_cpumask); 4106 4107 return (error); 4108 } 4109 4110 /* 4111 * Capture a user call chain. This function will be called from ast() 4112 * before control returns to userland and before the process gets 4113 * rescheduled. 4114 */ 4115 4116 static void 4117 pmc_capture_user_callchain(int cpu, int ring, struct trapframe *tf) 4118 { 4119 int i; 4120 struct pmc *pm; 4121 struct thread *td; 4122 struct pmc_sample *ps; 4123 struct pmc_samplebuffer *psb; 4124 #ifdef INVARIANTS 4125 int ncallchains; 4126 #endif 4127 4128 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4129 td = curthread; 4130 4131 KASSERT(td->td_pflags & TDP_CALLCHAIN, 4132 ("[pmc,%d] Retrieving callchain for thread that doesn't want it", 4133 __LINE__)); 4134 4135 #ifdef INVARIANTS 4136 ncallchains = 0; 4137 #endif 4138 4139 /* 4140 * Iterate through all deferred callchain requests. 4141 */ 4142 4143 ps = psb->ps_samples; 4144 for (i = 0; i < pmc_nsamples; i++, ps++) { 4145 4146 if (ps->ps_nsamples != PMC_SAMPLE_INUSE) 4147 continue; 4148 if (ps->ps_td != td) 4149 continue; 4150 4151 KASSERT(ps->ps_cpu == cpu, 4152 ("[pmc,%d] cpu mismatch ps_cpu=%d pcpu=%d", __LINE__, 4153 ps->ps_cpu, PCPU_GET(cpuid))); 4154 4155 pm = ps->ps_pmc; 4156 4157 KASSERT(pm->pm_flags & PMC_F_CALLCHAIN, 4158 ("[pmc,%d] Retrieving callchain for PMC that doesn't " 4159 "want it", __LINE__)); 4160 4161 KASSERT(pm->pm_runcount > 0, 4162 ("[pmc,%d] runcount %d", __LINE__, pm->pm_runcount)); 4163 4164 /* 4165 * Retrieve the callchain and mark the sample buffer 4166 * as 'processable' by the timer tick sweep code. 4167 */ 4168 ps->ps_nsamples = pmc_save_user_callchain(ps->ps_pc, 4169 pmc_callchaindepth, tf); 4170 4171 #ifdef INVARIANTS 4172 ncallchains++; 4173 #endif 4174 } 4175 4176 KASSERT(ncallchains > 0, 4177 ("[pmc,%d] cpu %d didn't find a sample to collect", __LINE__, 4178 cpu)); 4179 4180 KASSERT(td->td_pinned == 1, 4181 ("[pmc,%d] invalid td_pinned value", __LINE__)); 4182 sched_unpin(); /* Can migrate safely now. */ 4183 4184 return; 4185 } 4186 4187 /* 4188 * Process saved PC samples. 4189 */ 4190 4191 static void 4192 pmc_process_samples(int cpu, int ring) 4193 { 4194 struct pmc *pm; 4195 int adjri, n; 4196 struct thread *td; 4197 struct pmc_owner *po; 4198 struct pmc_sample *ps; 4199 struct pmc_classdep *pcd; 4200 struct pmc_samplebuffer *psb; 4201 4202 KASSERT(PCPU_GET(cpuid) == cpu, 4203 ("[pmc,%d] not on the correct CPU pcpu=%d cpu=%d", __LINE__, 4204 PCPU_GET(cpuid), cpu)); 4205 4206 psb = pmc_pcpu[cpu]->pc_sb[ring]; 4207 4208 for (n = 0; n < pmc_nsamples; n++) { /* bound on #iterations */ 4209 4210 ps = psb->ps_read; 4211 if (ps->ps_nsamples == PMC_SAMPLE_FREE) 4212 break; 4213 4214 pm = ps->ps_pmc; 4215 4216 KASSERT(pm->pm_runcount > 0, 4217 ("[pmc,%d] pm=%p runcount %d", __LINE__, (void *) pm, 4218 pm->pm_runcount)); 4219 4220 po = pm->pm_owner; 4221 4222 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 4223 ("[pmc,%d] pmc=%p non-sampling mode=%d", __LINE__, 4224 pm, PMC_TO_MODE(pm))); 4225 4226 /* Ignore PMCs that have been switched off */ 4227 if (pm->pm_state != PMC_STATE_RUNNING) 4228 goto entrydone; 4229 4230 /* If there is a pending AST wait for completion */ 4231 if (ps->ps_nsamples == PMC_SAMPLE_INUSE) { 4232 /* Need a rescan at a later time. */ 4233 CPU_SET_ATOMIC(cpu, &pmc_cpumask); 4234 break; 4235 } 4236 4237 PMCDBG(SAM,OPS,1,"cpu=%d pm=%p n=%d fl=%x wr=%d rd=%d", cpu, 4238 pm, ps->ps_nsamples, ps->ps_flags, 4239 (int) (psb->ps_write - psb->ps_samples), 4240 (int) (psb->ps_read - psb->ps_samples)); 4241 4242 /* 4243 * If this is a process-mode PMC that is attached to 4244 * its owner, and if the PC is in user mode, update 4245 * profiling statistics like timer-based profiling 4246 * would have done. 4247 */ 4248 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) { 4249 if (ps->ps_flags & PMC_CC_F_USERSPACE) { 4250 td = FIRST_THREAD_IN_PROC(po->po_owner); 4251 addupc_intr(td, ps->ps_pc[0], 1); 4252 } 4253 goto entrydone; 4254 } 4255 4256 /* 4257 * Otherwise, this is either a sampling mode PMC that 4258 * is attached to a different process than its owner, 4259 * or a system-wide sampling PMC. Dispatch a log 4260 * entry to the PMC's owner process. 4261 */ 4262 pmclog_process_callchain(pm, ps); 4263 4264 entrydone: 4265 ps->ps_nsamples = 0; /* mark entry as free */ 4266 atomic_subtract_rel_int(&pm->pm_runcount, 1); 4267 4268 /* increment read pointer, modulo sample size */ 4269 if (++ps == psb->ps_fence) 4270 psb->ps_read = psb->ps_samples; 4271 else 4272 psb->ps_read = ps; 4273 } 4274 4275 atomic_add_int(&pmc_stats.pm_log_sweeps, 1); 4276 4277 /* Do not re-enable stalled PMCs if we failed to process any samples */ 4278 if (n == 0) 4279 return; 4280 4281 /* 4282 * Restart any stalled sampling PMCs on this CPU. 4283 * 4284 * If the NMI handler sets the pm_stalled field of a PMC after 4285 * the check below, we'll end up processing the stalled PMC at 4286 * the next hardclock tick. 4287 */ 4288 for (n = 0; n < md->pmd_npmc; n++) { 4289 pcd = pmc_ri_to_classdep(md, n, &adjri); 4290 KASSERT(pcd != NULL, 4291 ("[pmc,%d] null pcd ri=%d", __LINE__, n)); 4292 (void) (*pcd->pcd_get_config)(cpu,adjri,&pm); 4293 4294 if (pm == NULL || /* !cfg'ed */ 4295 pm->pm_state != PMC_STATE_RUNNING || /* !active */ 4296 !PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) || /* !sampling */ 4297 pm->pm_stalled == 0) /* !stalled */ 4298 continue; 4299 4300 pm->pm_stalled = 0; 4301 (*pcd->pcd_start_pmc)(cpu, adjri); 4302 } 4303 } 4304 4305 /* 4306 * Event handlers. 4307 */ 4308 4309 /* 4310 * Handle a process exit. 4311 * 4312 * Remove this process from all hash tables. If this process 4313 * owned any PMCs, turn off those PMCs and deallocate them, 4314 * removing any associations with target processes. 4315 * 4316 * This function will be called by the last 'thread' of a 4317 * process. 4318 * 4319 * XXX This eventhandler gets called early in the exit process. 4320 * Consider using a 'hook' invocation from thread_exit() or equivalent 4321 * spot. Another negative is that kse_exit doesn't seem to call 4322 * exit1() [??]. 4323 * 4324 */ 4325 4326 static void 4327 pmc_process_exit(void *arg __unused, struct proc *p) 4328 { 4329 struct pmc *pm; 4330 int adjri, cpu; 4331 unsigned int ri; 4332 int is_using_hwpmcs; 4333 struct pmc_owner *po; 4334 struct pmc_process *pp; 4335 struct pmc_classdep *pcd; 4336 pmc_value_t newvalue, tmp; 4337 4338 PROC_LOCK(p); 4339 is_using_hwpmcs = p->p_flag & P_HWPMC; 4340 PROC_UNLOCK(p); 4341 4342 /* 4343 * Log a sysexit event to all SS PMC owners. 4344 */ 4345 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4346 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4347 pmclog_process_sysexit(po, p->p_pid); 4348 4349 if (!is_using_hwpmcs) 4350 return; 4351 4352 PMC_GET_SX_XLOCK(); 4353 PMCDBG(PRC,EXT,1,"process-exit proc=%p (%d, %s)", p, p->p_pid, 4354 p->p_comm); 4355 4356 /* 4357 * Since this code is invoked by the last thread in an exiting 4358 * process, we would have context switched IN at some prior 4359 * point. However, with PREEMPTION, kernel mode context 4360 * switches may happen any time, so we want to disable a 4361 * context switch OUT till we get any PMCs targetting this 4362 * process off the hardware. 4363 * 4364 * We also need to atomically remove this process' 4365 * entry from our target process hash table, using 4366 * PMC_FLAG_REMOVE. 4367 */ 4368 PMCDBG(PRC,EXT,1, "process-exit proc=%p (%d, %s)", p, p->p_pid, 4369 p->p_comm); 4370 4371 critical_enter(); /* no preemption */ 4372 4373 cpu = curthread->td_oncpu; 4374 4375 if ((pp = pmc_find_process_descriptor(p, 4376 PMC_FLAG_REMOVE)) != NULL) { 4377 4378 PMCDBG(PRC,EXT,2, 4379 "process-exit proc=%p pmc-process=%p", p, pp); 4380 4381 /* 4382 * The exiting process could the target of 4383 * some PMCs which will be running on 4384 * currently executing CPU. 4385 * 4386 * We need to turn these PMCs off like we 4387 * would do at context switch OUT time. 4388 */ 4389 for (ri = 0; ri < md->pmd_npmc; ri++) { 4390 4391 /* 4392 * Pick up the pmc pointer from hardware 4393 * state similar to the CSW_OUT code. 4394 */ 4395 pm = NULL; 4396 4397 pcd = pmc_ri_to_classdep(md, ri, &adjri); 4398 4399 (void) (*pcd->pcd_get_config)(cpu, adjri, &pm); 4400 4401 PMCDBG(PRC,EXT,2, "ri=%d pm=%p", ri, pm); 4402 4403 if (pm == NULL || 4404 !PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 4405 continue; 4406 4407 PMCDBG(PRC,EXT,2, "ppmcs[%d]=%p pm=%p " 4408 "state=%d", ri, pp->pp_pmcs[ri].pp_pmc, 4409 pm, pm->pm_state); 4410 4411 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 4412 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 4413 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 4414 4415 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 4416 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", 4417 __LINE__, pm, ri, pp->pp_pmcs[ri].pp_pmc)); 4418 4419 (void) pcd->pcd_stop_pmc(cpu, adjri); 4420 4421 KASSERT(pm->pm_runcount > 0, 4422 ("[pmc,%d] bad runcount ri %d rc %d", 4423 __LINE__, ri, pm->pm_runcount)); 4424 4425 /* Stop hardware only if it is actually running */ 4426 if (pm->pm_state == PMC_STATE_RUNNING && 4427 pm->pm_stalled == 0) { 4428 pcd->pcd_read_pmc(cpu, adjri, &newvalue); 4429 tmp = newvalue - 4430 PMC_PCPU_SAVED(cpu,ri); 4431 4432 mtx_pool_lock_spin(pmc_mtxpool, pm); 4433 pm->pm_gv.pm_savedvalue += tmp; 4434 pp->pp_pmcs[ri].pp_pmcval += tmp; 4435 mtx_pool_unlock_spin(pmc_mtxpool, pm); 4436 } 4437 4438 atomic_subtract_rel_int(&pm->pm_runcount,1); 4439 4440 KASSERT((int) pm->pm_runcount >= 0, 4441 ("[pmc,%d] runcount is %d", __LINE__, ri)); 4442 4443 (void) pcd->pcd_config_pmc(cpu, adjri, NULL); 4444 } 4445 4446 /* 4447 * Inform the MD layer of this pseudo "context switch 4448 * out" 4449 */ 4450 (void) md->pmd_switch_out(pmc_pcpu[cpu], pp); 4451 4452 critical_exit(); /* ok to be pre-empted now */ 4453 4454 /* 4455 * Unlink this process from the PMCs that are 4456 * targetting it. This will send a signal to 4457 * all PMC owner's whose PMCs are orphaned. 4458 * 4459 * Log PMC value at exit time if requested. 4460 */ 4461 for (ri = 0; ri < md->pmd_npmc; ri++) 4462 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 4463 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 4464 PMC_IS_COUNTING_MODE(PMC_TO_MODE(pm))) 4465 pmclog_process_procexit(pm, pp); 4466 pmc_unlink_target_process(pm, pp); 4467 } 4468 free(pp, M_PMC); 4469 4470 } else 4471 critical_exit(); /* pp == NULL */ 4472 4473 4474 /* 4475 * If the process owned PMCs, free them up and free up 4476 * memory. 4477 */ 4478 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 4479 pmc_remove_owner(po); 4480 pmc_destroy_owner_descriptor(po); 4481 } 4482 4483 sx_xunlock(&pmc_sx); 4484 } 4485 4486 /* 4487 * Handle a process fork. 4488 * 4489 * If the parent process 'p1' is under HWPMC monitoring, then copy 4490 * over any attached PMCs that have 'do_descendants' semantics. 4491 */ 4492 4493 static void 4494 pmc_process_fork(void *arg __unused, struct proc *p1, struct proc *newproc, 4495 int flags) 4496 { 4497 int is_using_hwpmcs; 4498 unsigned int ri; 4499 uint32_t do_descendants; 4500 struct pmc *pm; 4501 struct pmc_owner *po; 4502 struct pmc_process *ppnew, *ppold; 4503 4504 (void) flags; /* unused parameter */ 4505 4506 PROC_LOCK(p1); 4507 is_using_hwpmcs = p1->p_flag & P_HWPMC; 4508 PROC_UNLOCK(p1); 4509 4510 /* 4511 * If there are system-wide sampling PMCs active, we need to 4512 * log all fork events to their owner's logs. 4513 */ 4514 4515 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4516 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4517 pmclog_process_procfork(po, p1->p_pid, newproc->p_pid); 4518 4519 if (!is_using_hwpmcs) 4520 return; 4521 4522 PMC_GET_SX_XLOCK(); 4523 PMCDBG(PMC,FRK,1, "process-fork proc=%p (%d, %s) -> %p", p1, 4524 p1->p_pid, p1->p_comm, newproc); 4525 4526 /* 4527 * If the parent process (curthread->td_proc) is a 4528 * target of any PMCs, look for PMCs that are to be 4529 * inherited, and link these into the new process 4530 * descriptor. 4531 */ 4532 if ((ppold = pmc_find_process_descriptor(curthread->td_proc, 4533 PMC_FLAG_NONE)) == NULL) 4534 goto done; /* nothing to do */ 4535 4536 do_descendants = 0; 4537 for (ri = 0; ri < md->pmd_npmc; ri++) 4538 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL) 4539 do_descendants |= pm->pm_flags & PMC_F_DESCENDANTS; 4540 if (do_descendants == 0) /* nothing to do */ 4541 goto done; 4542 4543 /* allocate a descriptor for the new process */ 4544 if ((ppnew = pmc_find_process_descriptor(newproc, 4545 PMC_FLAG_ALLOCATE)) == NULL) 4546 goto done; 4547 4548 /* 4549 * Run through all PMCs that were targeting the old process 4550 * and which specified F_DESCENDANTS and attach them to the 4551 * new process. 4552 * 4553 * Log the fork event to all owners of PMCs attached to this 4554 * process, if not already logged. 4555 */ 4556 for (ri = 0; ri < md->pmd_npmc; ri++) 4557 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL && 4558 (pm->pm_flags & PMC_F_DESCENDANTS)) { 4559 pmc_link_target_process(pm, ppnew); 4560 po = pm->pm_owner; 4561 if (po->po_sscount == 0 && 4562 po->po_flags & PMC_PO_OWNS_LOGFILE) 4563 pmclog_process_procfork(po, p1->p_pid, 4564 newproc->p_pid); 4565 } 4566 4567 /* 4568 * Now mark the new process as being tracked by this driver. 4569 */ 4570 PROC_LOCK(newproc); 4571 newproc->p_flag |= P_HWPMC; 4572 PROC_UNLOCK(newproc); 4573 4574 done: 4575 sx_xunlock(&pmc_sx); 4576 } 4577 4578 static void 4579 pmc_kld_load(void *arg __unused, linker_file_t lf) 4580 { 4581 struct pmc_owner *po; 4582 4583 sx_slock(&pmc_sx); 4584 4585 /* 4586 * Notify owners of system sampling PMCs about KLD operations. 4587 */ 4588 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4589 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4590 pmclog_process_map_in(po, (pid_t) -1, 4591 (uintfptr_t) lf->address, lf->filename); 4592 4593 /* 4594 * TODO: Notify owners of (all) process-sampling PMCs too. 4595 */ 4596 4597 sx_sunlock(&pmc_sx); 4598 } 4599 4600 static void 4601 pmc_kld_unload(void *arg __unused, const char *filename __unused, 4602 caddr_t address, size_t size) 4603 { 4604 struct pmc_owner *po; 4605 4606 sx_slock(&pmc_sx); 4607 4608 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4609 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4610 pmclog_process_map_out(po, (pid_t) -1, 4611 (uintfptr_t) address, (uintfptr_t) address + size); 4612 4613 /* 4614 * TODO: Notify owners of process-sampling PMCs. 4615 */ 4616 4617 sx_sunlock(&pmc_sx); 4618 } 4619 4620 /* 4621 * initialization 4622 */ 4623 4624 static const char *pmc_name_of_pmcclass[] = { 4625 #undef __PMC_CLASS 4626 #define __PMC_CLASS(N) #N , 4627 __PMC_CLASSES() 4628 }; 4629 4630 /* 4631 * Base class initializer: allocate structure and set default classes. 4632 */ 4633 struct pmc_mdep * 4634 pmc_mdep_alloc(int nclasses) 4635 { 4636 struct pmc_mdep *md; 4637 int n; 4638 4639 /* SOFT + md classes */ 4640 n = 1 + nclasses; 4641 md = malloc(sizeof(struct pmc_mdep) + n * 4642 sizeof(struct pmc_classdep), M_PMC, M_WAITOK|M_ZERO); 4643 md->pmd_nclass = n; 4644 4645 /* Add base class. */ 4646 pmc_soft_initialize(md); 4647 return md; 4648 } 4649 4650 void 4651 pmc_mdep_free(struct pmc_mdep *md) 4652 { 4653 pmc_soft_finalize(md); 4654 free(md, M_PMC); 4655 } 4656 4657 static int 4658 generic_switch_in(struct pmc_cpu *pc, struct pmc_process *pp) 4659 { 4660 (void) pc; (void) pp; 4661 4662 return (0); 4663 } 4664 4665 static int 4666 generic_switch_out(struct pmc_cpu *pc, struct pmc_process *pp) 4667 { 4668 (void) pc; (void) pp; 4669 4670 return (0); 4671 } 4672 4673 static struct pmc_mdep * 4674 pmc_generic_cpu_initialize(void) 4675 { 4676 struct pmc_mdep *md; 4677 4678 md = pmc_mdep_alloc(0); 4679 4680 md->pmd_cputype = PMC_CPU_GENERIC; 4681 4682 md->pmd_pcpu_init = NULL; 4683 md->pmd_pcpu_fini = NULL; 4684 md->pmd_switch_in = generic_switch_in; 4685 md->pmd_switch_out = generic_switch_out; 4686 4687 return (md); 4688 } 4689 4690 static void 4691 pmc_generic_cpu_finalize(struct pmc_mdep *md) 4692 { 4693 (void) md; 4694 } 4695 4696 4697 static int 4698 pmc_initialize(void) 4699 { 4700 int c, cpu, error, n, ri; 4701 unsigned int maxcpu; 4702 struct pmc_binding pb; 4703 struct pmc_sample *ps; 4704 struct pmc_classdep *pcd; 4705 struct pmc_samplebuffer *sb; 4706 4707 md = NULL; 4708 error = 0; 4709 4710 #ifdef DEBUG 4711 /* parse debug flags first */ 4712 if (TUNABLE_STR_FETCH(PMC_SYSCTL_NAME_PREFIX "debugflags", 4713 pmc_debugstr, sizeof(pmc_debugstr))) 4714 pmc_debugflags_parse(pmc_debugstr, 4715 pmc_debugstr+strlen(pmc_debugstr)); 4716 #endif 4717 4718 PMCDBG(MOD,INI,0, "PMC Initialize (version %x)", PMC_VERSION); 4719 4720 /* check kernel version */ 4721 if (pmc_kernel_version != PMC_VERSION) { 4722 if (pmc_kernel_version == 0) 4723 printf("hwpmc: this kernel has not been compiled with " 4724 "'options HWPMC_HOOKS'.\n"); 4725 else 4726 printf("hwpmc: kernel version (0x%x) does not match " 4727 "module version (0x%x).\n", pmc_kernel_version, 4728 PMC_VERSION); 4729 return EPROGMISMATCH; 4730 } 4731 4732 /* 4733 * check sysctl parameters 4734 */ 4735 4736 if (pmc_hashsize <= 0) { 4737 (void) printf("hwpmc: tunable \"hashsize\"=%d must be " 4738 "greater than zero.\n", pmc_hashsize); 4739 pmc_hashsize = PMC_HASH_SIZE; 4740 } 4741 4742 if (pmc_nsamples <= 0 || pmc_nsamples > 65535) { 4743 (void) printf("hwpmc: tunable \"nsamples\"=%d out of " 4744 "range.\n", pmc_nsamples); 4745 pmc_nsamples = PMC_NSAMPLES; 4746 } 4747 4748 if (pmc_callchaindepth <= 0 || 4749 pmc_callchaindepth > PMC_CALLCHAIN_DEPTH_MAX) { 4750 (void) printf("hwpmc: tunable \"callchaindepth\"=%d out of " 4751 "range.\n", pmc_callchaindepth); 4752 pmc_callchaindepth = PMC_CALLCHAIN_DEPTH; 4753 } 4754 4755 md = pmc_md_initialize(); 4756 if (md == NULL) { 4757 /* Default to generic CPU. */ 4758 md = pmc_generic_cpu_initialize(); 4759 if (md == NULL) 4760 return (ENOSYS); 4761 } 4762 4763 KASSERT(md->pmd_nclass >= 1 && md->pmd_npmc >= 1, 4764 ("[pmc,%d] no classes or pmcs", __LINE__)); 4765 4766 /* Compute the map from row-indices to classdep pointers. */ 4767 pmc_rowindex_to_classdep = malloc(sizeof(struct pmc_classdep *) * 4768 md->pmd_npmc, M_PMC, M_WAITOK|M_ZERO); 4769 4770 for (n = 0; n < md->pmd_npmc; n++) 4771 pmc_rowindex_to_classdep[n] = NULL; 4772 for (ri = c = 0; c < md->pmd_nclass; c++) { 4773 pcd = &md->pmd_classdep[c]; 4774 for (n = 0; n < pcd->pcd_num; n++, ri++) 4775 pmc_rowindex_to_classdep[ri] = pcd; 4776 } 4777 4778 KASSERT(ri == md->pmd_npmc, 4779 ("[pmc,%d] npmc miscomputed: ri=%d, md->npmc=%d", __LINE__, 4780 ri, md->pmd_npmc)); 4781 4782 maxcpu = pmc_cpu_max(); 4783 4784 /* allocate space for the per-cpu array */ 4785 pmc_pcpu = malloc(maxcpu * sizeof(struct pmc_cpu *), M_PMC, 4786 M_WAITOK|M_ZERO); 4787 4788 /* per-cpu 'saved values' for managing process-mode PMCs */ 4789 pmc_pcpu_saved = malloc(sizeof(pmc_value_t) * maxcpu * md->pmd_npmc, 4790 M_PMC, M_WAITOK); 4791 4792 /* Perform CPU-dependent initialization. */ 4793 pmc_save_cpu_binding(&pb); 4794 error = 0; 4795 for (cpu = 0; error == 0 && cpu < maxcpu; cpu++) { 4796 if (!pmc_cpu_is_active(cpu)) 4797 continue; 4798 pmc_select_cpu(cpu); 4799 pmc_pcpu[cpu] = malloc(sizeof(struct pmc_cpu) + 4800 md->pmd_npmc * sizeof(struct pmc_hw *), M_PMC, 4801 M_WAITOK|M_ZERO); 4802 if (md->pmd_pcpu_init) 4803 error = md->pmd_pcpu_init(md, cpu); 4804 for (n = 0; error == 0 && n < md->pmd_nclass; n++) 4805 error = md->pmd_classdep[n].pcd_pcpu_init(md, cpu); 4806 } 4807 pmc_restore_cpu_binding(&pb); 4808 4809 if (error) 4810 return (error); 4811 4812 /* allocate space for the sample array */ 4813 for (cpu = 0; cpu < maxcpu; cpu++) { 4814 if (!pmc_cpu_is_active(cpu)) 4815 continue; 4816 4817 sb = malloc(sizeof(struct pmc_samplebuffer) + 4818 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 4819 M_WAITOK|M_ZERO); 4820 sb->ps_read = sb->ps_write = sb->ps_samples; 4821 sb->ps_fence = sb->ps_samples + pmc_nsamples; 4822 4823 KASSERT(pmc_pcpu[cpu] != NULL, 4824 ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu)); 4825 4826 sb->ps_callchains = malloc(pmc_callchaindepth * pmc_nsamples * 4827 sizeof(uintptr_t), M_PMC, M_WAITOK|M_ZERO); 4828 4829 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 4830 ps->ps_pc = sb->ps_callchains + 4831 (n * pmc_callchaindepth); 4832 4833 pmc_pcpu[cpu]->pc_sb[PMC_HR] = sb; 4834 4835 sb = malloc(sizeof(struct pmc_samplebuffer) + 4836 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 4837 M_WAITOK|M_ZERO); 4838 sb->ps_read = sb->ps_write = sb->ps_samples; 4839 sb->ps_fence = sb->ps_samples + pmc_nsamples; 4840 4841 KASSERT(pmc_pcpu[cpu] != NULL, 4842 ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu)); 4843 4844 sb->ps_callchains = malloc(pmc_callchaindepth * pmc_nsamples * 4845 sizeof(uintptr_t), M_PMC, M_WAITOK|M_ZERO); 4846 4847 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 4848 ps->ps_pc = sb->ps_callchains + 4849 (n * pmc_callchaindepth); 4850 4851 pmc_pcpu[cpu]->pc_sb[PMC_SR] = sb; 4852 } 4853 4854 /* allocate space for the row disposition array */ 4855 pmc_pmcdisp = malloc(sizeof(enum pmc_mode) * md->pmd_npmc, 4856 M_PMC, M_WAITOK|M_ZERO); 4857 4858 /* mark all PMCs as available */ 4859 for (n = 0; n < (int) md->pmd_npmc; n++) 4860 PMC_MARK_ROW_FREE(n); 4861 4862 /* allocate thread hash tables */ 4863 pmc_ownerhash = hashinit(pmc_hashsize, M_PMC, 4864 &pmc_ownerhashmask); 4865 4866 pmc_processhash = hashinit(pmc_hashsize, M_PMC, 4867 &pmc_processhashmask); 4868 mtx_init(&pmc_processhash_mtx, "pmc-process-hash", "pmc-leaf", 4869 MTX_SPIN); 4870 4871 LIST_INIT(&pmc_ss_owners); 4872 pmc_ss_count = 0; 4873 4874 /* allocate a pool of spin mutexes */ 4875 pmc_mtxpool = mtx_pool_create("pmc-leaf", pmc_mtxpool_size, 4876 MTX_SPIN); 4877 4878 PMCDBG(MOD,INI,1, "pmc_ownerhash=%p, mask=0x%lx " 4879 "targethash=%p mask=0x%lx", pmc_ownerhash, pmc_ownerhashmask, 4880 pmc_processhash, pmc_processhashmask); 4881 4882 /* register process {exit,fork,exec} handlers */ 4883 pmc_exit_tag = EVENTHANDLER_REGISTER(process_exit, 4884 pmc_process_exit, NULL, EVENTHANDLER_PRI_ANY); 4885 pmc_fork_tag = EVENTHANDLER_REGISTER(process_fork, 4886 pmc_process_fork, NULL, EVENTHANDLER_PRI_ANY); 4887 4888 /* register kld event handlers */ 4889 pmc_kld_load_tag = EVENTHANDLER_REGISTER(kld_load, pmc_kld_load, 4890 NULL, EVENTHANDLER_PRI_ANY); 4891 pmc_kld_unload_tag = EVENTHANDLER_REGISTER(kld_unload, pmc_kld_unload, 4892 NULL, EVENTHANDLER_PRI_ANY); 4893 4894 /* initialize logging */ 4895 pmclog_initialize(); 4896 4897 /* set hook functions */ 4898 pmc_intr = md->pmd_intr; 4899 pmc_hook = pmc_hook_handler; 4900 4901 if (error == 0) { 4902 printf(PMC_MODULE_NAME ":"); 4903 for (n = 0; n < (int) md->pmd_nclass; n++) { 4904 pcd = &md->pmd_classdep[n]; 4905 printf(" %s/%d/%d/0x%b", 4906 pmc_name_of_pmcclass[pcd->pcd_class], 4907 pcd->pcd_num, 4908 pcd->pcd_width, 4909 pcd->pcd_caps, 4910 "\20" 4911 "\1INT\2USR\3SYS\4EDG\5THR" 4912 "\6REA\7WRI\10INV\11QUA\12PRC" 4913 "\13TAG\14CSC"); 4914 } 4915 printf("\n"); 4916 } 4917 4918 return (error); 4919 } 4920 4921 /* prepare to be unloaded */ 4922 static void 4923 pmc_cleanup(void) 4924 { 4925 int c, cpu; 4926 unsigned int maxcpu; 4927 struct pmc_ownerhash *ph; 4928 struct pmc_owner *po, *tmp; 4929 struct pmc_binding pb; 4930 #ifdef DEBUG 4931 struct pmc_processhash *prh; 4932 #endif 4933 4934 PMCDBG(MOD,INI,0, "%s", "cleanup"); 4935 4936 /* switch off sampling */ 4937 CPU_ZERO(&pmc_cpumask); 4938 pmc_intr = NULL; 4939 4940 sx_xlock(&pmc_sx); 4941 if (pmc_hook == NULL) { /* being unloaded already */ 4942 sx_xunlock(&pmc_sx); 4943 return; 4944 } 4945 4946 pmc_hook = NULL; /* prevent new threads from entering module */ 4947 4948 /* deregister event handlers */ 4949 EVENTHANDLER_DEREGISTER(process_fork, pmc_fork_tag); 4950 EVENTHANDLER_DEREGISTER(process_exit, pmc_exit_tag); 4951 EVENTHANDLER_DEREGISTER(kld_load, pmc_kld_load_tag); 4952 EVENTHANDLER_DEREGISTER(kld_unload, pmc_kld_unload_tag); 4953 4954 /* send SIGBUS to all owner threads, free up allocations */ 4955 if (pmc_ownerhash) 4956 for (ph = pmc_ownerhash; 4957 ph <= &pmc_ownerhash[pmc_ownerhashmask]; 4958 ph++) { 4959 LIST_FOREACH_SAFE(po, ph, po_next, tmp) { 4960 pmc_remove_owner(po); 4961 4962 /* send SIGBUS to owner processes */ 4963 PMCDBG(MOD,INI,2, "cleanup signal proc=%p " 4964 "(%d, %s)", po->po_owner, 4965 po->po_owner->p_pid, 4966 po->po_owner->p_comm); 4967 4968 PROC_LOCK(po->po_owner); 4969 kern_psignal(po->po_owner, SIGBUS); 4970 PROC_UNLOCK(po->po_owner); 4971 4972 pmc_destroy_owner_descriptor(po); 4973 } 4974 } 4975 4976 /* reclaim allocated data structures */ 4977 if (pmc_mtxpool) 4978 mtx_pool_destroy(&pmc_mtxpool); 4979 4980 mtx_destroy(&pmc_processhash_mtx); 4981 if (pmc_processhash) { 4982 #ifdef DEBUG 4983 struct pmc_process *pp; 4984 4985 PMCDBG(MOD,INI,3, "%s", "destroy process hash"); 4986 for (prh = pmc_processhash; 4987 prh <= &pmc_processhash[pmc_processhashmask]; 4988 prh++) 4989 LIST_FOREACH(pp, prh, pp_next) 4990 PMCDBG(MOD,INI,3, "pid=%d", pp->pp_proc->p_pid); 4991 #endif 4992 4993 hashdestroy(pmc_processhash, M_PMC, pmc_processhashmask); 4994 pmc_processhash = NULL; 4995 } 4996 4997 if (pmc_ownerhash) { 4998 PMCDBG(MOD,INI,3, "%s", "destroy owner hash"); 4999 hashdestroy(pmc_ownerhash, M_PMC, pmc_ownerhashmask); 5000 pmc_ownerhash = NULL; 5001 } 5002 5003 KASSERT(LIST_EMPTY(&pmc_ss_owners), 5004 ("[pmc,%d] Global SS owner list not empty", __LINE__)); 5005 KASSERT(pmc_ss_count == 0, 5006 ("[pmc,%d] Global SS count not empty", __LINE__)); 5007 5008 /* do processor and pmc-class dependent cleanup */ 5009 maxcpu = pmc_cpu_max(); 5010 5011 PMCDBG(MOD,INI,3, "%s", "md cleanup"); 5012 if (md) { 5013 pmc_save_cpu_binding(&pb); 5014 for (cpu = 0; cpu < maxcpu; cpu++) { 5015 PMCDBG(MOD,INI,1,"pmc-cleanup cpu=%d pcs=%p", 5016 cpu, pmc_pcpu[cpu]); 5017 if (!pmc_cpu_is_active(cpu) || pmc_pcpu[cpu] == NULL) 5018 continue; 5019 pmc_select_cpu(cpu); 5020 for (c = 0; c < md->pmd_nclass; c++) 5021 md->pmd_classdep[c].pcd_pcpu_fini(md, cpu); 5022 if (md->pmd_pcpu_fini) 5023 md->pmd_pcpu_fini(md, cpu); 5024 } 5025 5026 if (md->pmd_cputype == PMC_CPU_GENERIC) 5027 pmc_generic_cpu_finalize(md); 5028 else 5029 pmc_md_finalize(md); 5030 5031 pmc_mdep_free(md); 5032 md = NULL; 5033 pmc_restore_cpu_binding(&pb); 5034 } 5035 5036 /* Free per-cpu descriptors. */ 5037 for (cpu = 0; cpu < maxcpu; cpu++) { 5038 if (!pmc_cpu_is_active(cpu)) 5039 continue; 5040 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_HR] != NULL, 5041 ("[pmc,%d] Null hw cpu sample buffer cpu=%d", __LINE__, 5042 cpu)); 5043 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_SR] != NULL, 5044 ("[pmc,%d] Null sw cpu sample buffer cpu=%d", __LINE__, 5045 cpu)); 5046 free(pmc_pcpu[cpu]->pc_sb[PMC_HR]->ps_callchains, M_PMC); 5047 free(pmc_pcpu[cpu]->pc_sb[PMC_HR], M_PMC); 5048 free(pmc_pcpu[cpu]->pc_sb[PMC_SR]->ps_callchains, M_PMC); 5049 free(pmc_pcpu[cpu]->pc_sb[PMC_SR], M_PMC); 5050 free(pmc_pcpu[cpu], M_PMC); 5051 } 5052 5053 free(pmc_pcpu, M_PMC); 5054 pmc_pcpu = NULL; 5055 5056 free(pmc_pcpu_saved, M_PMC); 5057 pmc_pcpu_saved = NULL; 5058 5059 if (pmc_pmcdisp) { 5060 free(pmc_pmcdisp, M_PMC); 5061 pmc_pmcdisp = NULL; 5062 } 5063 5064 if (pmc_rowindex_to_classdep) { 5065 free(pmc_rowindex_to_classdep, M_PMC); 5066 pmc_rowindex_to_classdep = NULL; 5067 } 5068 5069 pmclog_shutdown(); 5070 5071 sx_xunlock(&pmc_sx); /* we are done */ 5072 } 5073 5074 /* 5075 * The function called at load/unload. 5076 */ 5077 5078 static int 5079 load (struct module *module __unused, int cmd, void *arg __unused) 5080 { 5081 int error; 5082 5083 error = 0; 5084 5085 switch (cmd) { 5086 case MOD_LOAD : 5087 /* initialize the subsystem */ 5088 error = pmc_initialize(); 5089 if (error != 0) 5090 break; 5091 PMCDBG(MOD,INI,1, "syscall=%d maxcpu=%d", 5092 pmc_syscall_num, pmc_cpu_max()); 5093 break; 5094 5095 5096 case MOD_UNLOAD : 5097 case MOD_SHUTDOWN: 5098 pmc_cleanup(); 5099 PMCDBG(MOD,INI,1, "%s", "unloaded"); 5100 break; 5101 5102 default : 5103 error = EINVAL; /* XXX should panic(9) */ 5104 break; 5105 } 5106 5107 return error; 5108 } 5109 5110 /* memory pool */ 5111 MALLOC_DEFINE(M_PMC, "pmc", "Memory space for the PMC module"); 5112