1 /*- 2 * Copyright (c) 2003-2007 Joseph Koshy 3 * Copyright (c) 2007 The FreeBSD Foundation 4 * All rights reserved. 5 * 6 * Portions of this software were developed by A. Joseph Koshy under 7 * sponsorship from the FreeBSD Foundation and Google, Inc. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 * 30 */ 31 32 #include <sys/cdefs.h> 33 __FBSDID("$FreeBSD$"); 34 35 #include <sys/param.h> 36 #include <sys/eventhandler.h> 37 #include <sys/jail.h> 38 #include <sys/kernel.h> 39 #include <sys/kthread.h> 40 #include <sys/limits.h> 41 #include <sys/lock.h> 42 #include <sys/malloc.h> 43 #include <sys/module.h> 44 #include <sys/mutex.h> 45 #include <sys/pmc.h> 46 #include <sys/pmckern.h> 47 #include <sys/pmclog.h> 48 #include <sys/priv.h> 49 #include <sys/proc.h> 50 #include <sys/queue.h> 51 #include <sys/resourcevar.h> 52 #include <sys/sched.h> 53 #include <sys/signalvar.h> 54 #include <sys/smp.h> 55 #include <sys/sx.h> 56 #include <sys/sysctl.h> 57 #include <sys/sysent.h> 58 #include <sys/systm.h> 59 #include <sys/vnode.h> 60 61 #include <sys/linker.h> /* needs to be after <sys/malloc.h> */ 62 63 #include <machine/atomic.h> 64 #include <machine/md_var.h> 65 66 /* 67 * Types 68 */ 69 70 enum pmc_flags { 71 PMC_FLAG_NONE = 0x00, /* do nothing */ 72 PMC_FLAG_REMOVE = 0x01, /* atomically remove entry from hash */ 73 PMC_FLAG_ALLOCATE = 0x02, /* add entry to hash if not found */ 74 }; 75 76 /* 77 * The offset in sysent where the syscall is allocated. 78 */ 79 80 static int pmc_syscall_num = NO_SYSCALL; 81 struct pmc_cpu **pmc_pcpu; /* per-cpu state */ 82 pmc_value_t *pmc_pcpu_saved; /* saved PMC values: CSW handling */ 83 84 #define PMC_PCPU_SAVED(C,R) pmc_pcpu_saved[(R) + md->pmd_npmc*(C)] 85 86 struct mtx_pool *pmc_mtxpool; 87 static int *pmc_pmcdisp; /* PMC row dispositions */ 88 89 #define PMC_ROW_DISP_IS_FREE(R) (pmc_pmcdisp[(R)] == 0) 90 #define PMC_ROW_DISP_IS_THREAD(R) (pmc_pmcdisp[(R)] > 0) 91 #define PMC_ROW_DISP_IS_STANDALONE(R) (pmc_pmcdisp[(R)] < 0) 92 93 #define PMC_MARK_ROW_FREE(R) do { \ 94 pmc_pmcdisp[(R)] = 0; \ 95 } while (0) 96 97 #define PMC_MARK_ROW_STANDALONE(R) do { \ 98 KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \ 99 __LINE__)); \ 100 atomic_add_int(&pmc_pmcdisp[(R)], -1); \ 101 KASSERT(pmc_pmcdisp[(R)] >= (-mp_ncpus), ("[pmc,%d] row " \ 102 "disposition error", __LINE__)); \ 103 } while (0) 104 105 #define PMC_UNMARK_ROW_STANDALONE(R) do { \ 106 atomic_add_int(&pmc_pmcdisp[(R)], 1); \ 107 KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \ 108 __LINE__)); \ 109 } while (0) 110 111 #define PMC_MARK_ROW_THREAD(R) do { \ 112 KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \ 113 __LINE__)); \ 114 atomic_add_int(&pmc_pmcdisp[(R)], 1); \ 115 } while (0) 116 117 #define PMC_UNMARK_ROW_THREAD(R) do { \ 118 atomic_add_int(&pmc_pmcdisp[(R)], -1); \ 119 KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \ 120 __LINE__)); \ 121 } while (0) 122 123 124 /* various event handlers */ 125 static eventhandler_tag pmc_exit_tag, pmc_fork_tag; 126 127 /* Module statistics */ 128 struct pmc_op_getdriverstats pmc_stats; 129 130 /* Machine/processor dependent operations */ 131 struct pmc_mdep *md; 132 133 /* 134 * Hash tables mapping owner processes and target threads to PMCs. 135 */ 136 137 struct mtx pmc_processhash_mtx; /* spin mutex */ 138 static u_long pmc_processhashmask; 139 static LIST_HEAD(pmc_processhash, pmc_process) *pmc_processhash; 140 141 /* 142 * Hash table of PMC owner descriptors. This table is protected by 143 * the shared PMC "sx" lock. 144 */ 145 146 static u_long pmc_ownerhashmask; 147 static LIST_HEAD(pmc_ownerhash, pmc_owner) *pmc_ownerhash; 148 149 /* 150 * List of PMC owners with system-wide sampling PMCs. 151 */ 152 153 static LIST_HEAD(, pmc_owner) pmc_ss_owners; 154 155 156 /* 157 * Prototypes 158 */ 159 160 #ifdef DEBUG 161 static int pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS); 162 static int pmc_debugflags_parse(char *newstr, char *fence); 163 #endif 164 165 static int load(struct module *module, int cmd, void *arg); 166 static int pmc_attach_process(struct proc *p, struct pmc *pm); 167 static struct pmc *pmc_allocate_pmc_descriptor(void); 168 static struct pmc_owner *pmc_allocate_owner_descriptor(struct proc *p); 169 static int pmc_attach_one_process(struct proc *p, struct pmc *pm); 170 static int pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, 171 int cpu); 172 static int pmc_can_attach(struct pmc *pm, struct proc *p); 173 static void pmc_capture_user_callchain(int cpu, struct trapframe *tf); 174 static void pmc_cleanup(void); 175 static int pmc_detach_process(struct proc *p, struct pmc *pm); 176 static int pmc_detach_one_process(struct proc *p, struct pmc *pm, 177 int flags); 178 static void pmc_destroy_owner_descriptor(struct pmc_owner *po); 179 static struct pmc_owner *pmc_find_owner_descriptor(struct proc *p); 180 static int pmc_find_pmc(pmc_id_t pmcid, struct pmc **pm); 181 static struct pmc *pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, 182 pmc_id_t pmc); 183 static struct pmc_process *pmc_find_process_descriptor(struct proc *p, 184 uint32_t mode); 185 static void pmc_force_context_switch(void); 186 static void pmc_link_target_process(struct pmc *pm, 187 struct pmc_process *pp); 188 static void pmc_log_all_process_mappings(struct pmc_owner *po); 189 static void pmc_log_kernel_mappings(struct pmc *pm); 190 static void pmc_log_process_mappings(struct pmc_owner *po, struct proc *p); 191 static void pmc_maybe_remove_owner(struct pmc_owner *po); 192 static void pmc_process_csw_in(struct thread *td); 193 static void pmc_process_csw_out(struct thread *td); 194 static void pmc_process_exit(void *arg, struct proc *p); 195 static void pmc_process_fork(void *arg, struct proc *p1, 196 struct proc *p2, int n); 197 static void pmc_process_samples(int cpu); 198 static void pmc_release_pmc_descriptor(struct pmc *pmc); 199 static void pmc_remove_owner(struct pmc_owner *po); 200 static void pmc_remove_process_descriptor(struct pmc_process *pp); 201 static void pmc_restore_cpu_binding(struct pmc_binding *pb); 202 static void pmc_save_cpu_binding(struct pmc_binding *pb); 203 static void pmc_select_cpu(int cpu); 204 static int pmc_start(struct pmc *pm); 205 static int pmc_stop(struct pmc *pm); 206 static int pmc_syscall_handler(struct thread *td, void *syscall_args); 207 static void pmc_unlink_target_process(struct pmc *pmc, 208 struct pmc_process *pp); 209 210 /* 211 * Kernel tunables and sysctl(8) interface. 212 */ 213 214 SYSCTL_NODE(_kern, OID_AUTO, hwpmc, CTLFLAG_RW, 0, "HWPMC parameters"); 215 216 static int pmc_callchaindepth = PMC_CALLCHAIN_DEPTH; 217 TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "callchaindepth", &pmc_callchaindepth); 218 SYSCTL_INT(_kern_hwpmc, OID_AUTO, callchaindepth, CTLFLAG_TUN|CTLFLAG_RD, 219 &pmc_callchaindepth, 0, "depth of call chain records"); 220 221 #ifdef DEBUG 222 struct pmc_debugflags pmc_debugflags = PMC_DEBUG_DEFAULT_FLAGS; 223 char pmc_debugstr[PMC_DEBUG_STRSIZE]; 224 TUNABLE_STR(PMC_SYSCTL_NAME_PREFIX "debugflags", pmc_debugstr, 225 sizeof(pmc_debugstr)); 226 SYSCTL_PROC(_kern_hwpmc, OID_AUTO, debugflags, 227 CTLTYPE_STRING|CTLFLAG_RW|CTLFLAG_TUN, 228 0, 0, pmc_debugflags_sysctl_handler, "A", "debug flags"); 229 #endif 230 231 /* 232 * kern.hwpmc.hashrows -- determines the number of rows in the 233 * of the hash table used to look up threads 234 */ 235 236 static int pmc_hashsize = PMC_HASH_SIZE; 237 TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "hashsize", &pmc_hashsize); 238 SYSCTL_INT(_kern_hwpmc, OID_AUTO, hashsize, CTLFLAG_TUN|CTLFLAG_RD, 239 &pmc_hashsize, 0, "rows in hash tables"); 240 241 /* 242 * kern.hwpmc.nsamples --- number of PC samples/callchain stacks per CPU 243 */ 244 245 static int pmc_nsamples = PMC_NSAMPLES; 246 TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "nsamples", &pmc_nsamples); 247 SYSCTL_INT(_kern_hwpmc, OID_AUTO, nsamples, CTLFLAG_TUN|CTLFLAG_RD, 248 &pmc_nsamples, 0, "number of PC samples per CPU"); 249 250 251 /* 252 * kern.hwpmc.mtxpoolsize -- number of mutexes in the mutex pool. 253 */ 254 255 static int pmc_mtxpool_size = PMC_MTXPOOL_SIZE; 256 TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "mtxpoolsize", &pmc_mtxpool_size); 257 SYSCTL_INT(_kern_hwpmc, OID_AUTO, mtxpoolsize, CTLFLAG_TUN|CTLFLAG_RD, 258 &pmc_mtxpool_size, 0, "size of spin mutex pool"); 259 260 261 /* 262 * security.bsd.unprivileged_syspmcs -- allow non-root processes to 263 * allocate system-wide PMCs. 264 * 265 * Allowing unprivileged processes to allocate system PMCs is convenient 266 * if system-wide measurements need to be taken concurrently with other 267 * per-process measurements. This feature is turned off by default. 268 */ 269 270 static int pmc_unprivileged_syspmcs = 0; 271 TUNABLE_INT("security.bsd.unprivileged_syspmcs", &pmc_unprivileged_syspmcs); 272 SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_syspmcs, CTLFLAG_RW, 273 &pmc_unprivileged_syspmcs, 0, 274 "allow unprivileged process to allocate system PMCs"); 275 276 /* 277 * Hash function. Discard the lower 2 bits of the pointer since 278 * these are always zero for our uses. The hash multiplier is 279 * round((2^LONG_BIT) * ((sqrt(5)-1)/2)). 280 */ 281 282 #if LONG_BIT == 64 283 #define _PMC_HM 11400714819323198486u 284 #elif LONG_BIT == 32 285 #define _PMC_HM 2654435769u 286 #else 287 #error Must know the size of 'long' to compile 288 #endif 289 290 #define PMC_HASH_PTR(P,M) ((((unsigned long) (P) >> 2) * _PMC_HM) & (M)) 291 292 /* 293 * Syscall structures 294 */ 295 296 /* The `sysent' for the new syscall */ 297 static struct sysent pmc_sysent = { 298 2, /* sy_narg */ 299 pmc_syscall_handler /* sy_call */ 300 }; 301 302 static struct syscall_module_data pmc_syscall_mod = { 303 load, 304 NULL, 305 &pmc_syscall_num, 306 &pmc_sysent, 307 { 0, NULL } 308 }; 309 310 static moduledata_t pmc_mod = { 311 PMC_MODULE_NAME, 312 syscall_module_handler, 313 &pmc_syscall_mod 314 }; 315 316 DECLARE_MODULE(pmc, pmc_mod, SI_SUB_SMP, SI_ORDER_ANY); 317 MODULE_VERSION(pmc, PMC_VERSION); 318 319 #ifdef DEBUG 320 enum pmc_dbgparse_state { 321 PMCDS_WS, /* in whitespace */ 322 PMCDS_MAJOR, /* seen a major keyword */ 323 PMCDS_MINOR 324 }; 325 326 static int 327 pmc_debugflags_parse(char *newstr, char *fence) 328 { 329 char c, *p, *q; 330 struct pmc_debugflags *tmpflags; 331 int error, found, *newbits, tmp; 332 size_t kwlen; 333 334 MALLOC(tmpflags, struct pmc_debugflags *, sizeof(*tmpflags), 335 M_PMC, M_WAITOK|M_ZERO); 336 337 p = newstr; 338 error = 0; 339 340 for (; p < fence && (c = *p); p++) { 341 342 /* skip white space */ 343 if (c == ' ' || c == '\t') 344 continue; 345 346 /* look for a keyword followed by "=" */ 347 for (q = p; p < fence && (c = *p) && c != '='; p++) 348 ; 349 if (c != '=') { 350 error = EINVAL; 351 goto done; 352 } 353 354 kwlen = p - q; 355 newbits = NULL; 356 357 /* lookup flag group name */ 358 #define DBG_SET_FLAG_MAJ(S,F) \ 359 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \ 360 newbits = &tmpflags->pdb_ ## F; 361 362 DBG_SET_FLAG_MAJ("cpu", CPU); 363 DBG_SET_FLAG_MAJ("csw", CSW); 364 DBG_SET_FLAG_MAJ("logging", LOG); 365 DBG_SET_FLAG_MAJ("module", MOD); 366 DBG_SET_FLAG_MAJ("md", MDP); 367 DBG_SET_FLAG_MAJ("owner", OWN); 368 DBG_SET_FLAG_MAJ("pmc", PMC); 369 DBG_SET_FLAG_MAJ("process", PRC); 370 DBG_SET_FLAG_MAJ("sampling", SAM); 371 372 if (newbits == NULL) { 373 error = EINVAL; 374 goto done; 375 } 376 377 p++; /* skip the '=' */ 378 379 /* Now parse the individual flags */ 380 tmp = 0; 381 newflag: 382 for (q = p; p < fence && (c = *p); p++) 383 if (c == ' ' || c == '\t' || c == ',') 384 break; 385 386 /* p == fence or c == ws or c == "," or c == 0 */ 387 388 if ((kwlen = p - q) == 0) { 389 *newbits = tmp; 390 continue; 391 } 392 393 found = 0; 394 #define DBG_SET_FLAG_MIN(S,F) \ 395 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0) \ 396 tmp |= found = (1 << PMC_DEBUG_MIN_ ## F) 397 398 /* a '*' denotes all possible flags in the group */ 399 if (kwlen == 1 && *q == '*') 400 tmp = found = ~0; 401 /* look for individual flag names */ 402 DBG_SET_FLAG_MIN("allocaterow", ALR); 403 DBG_SET_FLAG_MIN("allocate", ALL); 404 DBG_SET_FLAG_MIN("attach", ATT); 405 DBG_SET_FLAG_MIN("bind", BND); 406 DBG_SET_FLAG_MIN("config", CFG); 407 DBG_SET_FLAG_MIN("exec", EXC); 408 DBG_SET_FLAG_MIN("exit", EXT); 409 DBG_SET_FLAG_MIN("find", FND); 410 DBG_SET_FLAG_MIN("flush", FLS); 411 DBG_SET_FLAG_MIN("fork", FRK); 412 DBG_SET_FLAG_MIN("getbuf", GTB); 413 DBG_SET_FLAG_MIN("hook", PMH); 414 DBG_SET_FLAG_MIN("init", INI); 415 DBG_SET_FLAG_MIN("intr", INT); 416 DBG_SET_FLAG_MIN("linktarget", TLK); 417 DBG_SET_FLAG_MIN("mayberemove", OMR); 418 DBG_SET_FLAG_MIN("ops", OPS); 419 DBG_SET_FLAG_MIN("read", REA); 420 DBG_SET_FLAG_MIN("register", REG); 421 DBG_SET_FLAG_MIN("release", REL); 422 DBG_SET_FLAG_MIN("remove", ORM); 423 DBG_SET_FLAG_MIN("sample", SAM); 424 DBG_SET_FLAG_MIN("scheduleio", SIO); 425 DBG_SET_FLAG_MIN("select", SEL); 426 DBG_SET_FLAG_MIN("signal", SIG); 427 DBG_SET_FLAG_MIN("swi", SWI); 428 DBG_SET_FLAG_MIN("swo", SWO); 429 DBG_SET_FLAG_MIN("start", STA); 430 DBG_SET_FLAG_MIN("stop", STO); 431 DBG_SET_FLAG_MIN("syscall", PMS); 432 DBG_SET_FLAG_MIN("unlinktarget", TUL); 433 DBG_SET_FLAG_MIN("write", WRI); 434 if (found == 0) { 435 /* unrecognized flag name */ 436 error = EINVAL; 437 goto done; 438 } 439 440 if (c == 0 || c == ' ' || c == '\t') { /* end of flag group */ 441 *newbits = tmp; 442 continue; 443 } 444 445 p++; 446 goto newflag; 447 } 448 449 /* save the new flag set */ 450 bcopy(tmpflags, &pmc_debugflags, sizeof(pmc_debugflags)); 451 452 done: 453 FREE(tmpflags, M_PMC); 454 return error; 455 } 456 457 static int 458 pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS) 459 { 460 char *fence, *newstr; 461 int error; 462 unsigned int n; 463 464 (void) arg1; (void) arg2; /* unused parameters */ 465 466 n = sizeof(pmc_debugstr); 467 MALLOC(newstr, char *, n, M_PMC, M_ZERO|M_WAITOK); 468 (void) strlcpy(newstr, pmc_debugstr, n); 469 470 error = sysctl_handle_string(oidp, newstr, n, req); 471 472 /* if there is a new string, parse and copy it */ 473 if (error == 0 && req->newptr != NULL) { 474 fence = newstr + (n < req->newlen ? n : req->newlen + 1); 475 if ((error = pmc_debugflags_parse(newstr, fence)) == 0) 476 (void) strlcpy(pmc_debugstr, newstr, 477 sizeof(pmc_debugstr)); 478 } 479 480 FREE(newstr, M_PMC); 481 482 return error; 483 } 484 #endif 485 486 /* 487 * Concurrency Control 488 * 489 * The driver manages the following data structures: 490 * 491 * - target process descriptors, one per target process 492 * - owner process descriptors (and attached lists), one per owner process 493 * - lookup hash tables for owner and target processes 494 * - PMC descriptors (and attached lists) 495 * - per-cpu hardware state 496 * - the 'hook' variable through which the kernel calls into 497 * this module 498 * - the machine hardware state (managed by the MD layer) 499 * 500 * These data structures are accessed from: 501 * 502 * - thread context-switch code 503 * - interrupt handlers (possibly on multiple cpus) 504 * - kernel threads on multiple cpus running on behalf of user 505 * processes doing system calls 506 * - this driver's private kernel threads 507 * 508 * = Locks and Locking strategy = 509 * 510 * The driver uses four locking strategies for its operation: 511 * 512 * - The global SX lock "pmc_sx" is used to protect internal 513 * data structures. 514 * 515 * Calls into the module by syscall() start with this lock being 516 * held in exclusive mode. Depending on the requested operation, 517 * the lock may be downgraded to 'shared' mode to allow more 518 * concurrent readers into the module. Calls into the module from 519 * other parts of the kernel acquire the lock in shared mode. 520 * 521 * This SX lock is held in exclusive mode for any operations that 522 * modify the linkages between the driver's internal data structures. 523 * 524 * The 'pmc_hook' function pointer is also protected by this lock. 525 * It is only examined with the sx lock held in exclusive mode. The 526 * kernel module is allowed to be unloaded only with the sx lock held 527 * in exclusive mode. In normal syscall handling, after acquiring the 528 * pmc_sx lock we first check that 'pmc_hook' is non-null before 529 * proceeding. This prevents races between the thread unloading the module 530 * and other threads seeking to use the module. 531 * 532 * - Lookups of target process structures and owner process structures 533 * cannot use the global "pmc_sx" SX lock because these lookups need 534 * to happen during context switches and in other critical sections 535 * where sleeping is not allowed. We protect these lookup tables 536 * with their own private spin-mutexes, "pmc_processhash_mtx" and 537 * "pmc_ownerhash_mtx". 538 * 539 * - Interrupt handlers work in a lock free manner. At interrupt 540 * time, handlers look at the PMC pointer (phw->phw_pmc) configured 541 * when the PMC was started. If this pointer is NULL, the interrupt 542 * is ignored after updating driver statistics. We ensure that this 543 * pointer is set (using an atomic operation if necessary) before the 544 * PMC hardware is started. Conversely, this pointer is unset atomically 545 * only after the PMC hardware is stopped. 546 * 547 * We ensure that everything needed for the operation of an 548 * interrupt handler is available without it needing to acquire any 549 * locks. We also ensure that a PMC's software state is destroyed only 550 * after the PMC is taken off hardware (on all CPUs). 551 * 552 * - Context-switch handling with process-private PMCs needs more 553 * care. 554 * 555 * A given process may be the target of multiple PMCs. For example, 556 * PMCATTACH and PMCDETACH may be requested by a process on one CPU 557 * while the target process is running on another. A PMC could also 558 * be getting released because its owner is exiting. We tackle 559 * these situations in the following manner: 560 * 561 * - each target process structure 'pmc_process' has an array 562 * of 'struct pmc *' pointers, one for each hardware PMC. 563 * 564 * - At context switch IN time, each "target" PMC in RUNNING state 565 * gets started on hardware and a pointer to each PMC is copied into 566 * the per-cpu phw array. The 'runcount' for the PMC is 567 * incremented. 568 * 569 * - At context switch OUT time, all process-virtual PMCs are stopped 570 * on hardware. The saved value is added to the PMCs value field 571 * only if the PMC is in a non-deleted state (the PMCs state could 572 * have changed during the current time slice). 573 * 574 * Note that since in-between a switch IN on a processor and a switch 575 * OUT, the PMC could have been released on another CPU. Therefore 576 * context switch OUT always looks at the hardware state to turn 577 * OFF PMCs and will update a PMC's saved value only if reachable 578 * from the target process record. 579 * 580 * - OP PMCRELEASE could be called on a PMC at any time (the PMC could 581 * be attached to many processes at the time of the call and could 582 * be active on multiple CPUs). 583 * 584 * We prevent further scheduling of the PMC by marking it as in 585 * state 'DELETED'. If the runcount of the PMC is non-zero then 586 * this PMC is currently running on a CPU somewhere. The thread 587 * doing the PMCRELEASE operation waits by repeatedly doing a 588 * pause() till the runcount comes to zero. 589 * 590 * The contents of a PMC descriptor (struct pmc) are protected using 591 * a spin-mutex. In order to save space, we use a mutex pool. 592 * 593 * In terms of lock types used by witness(4), we use: 594 * - Type "pmc-sx", used by the global SX lock. 595 * - Type "pmc-sleep", for sleep mutexes used by logger threads. 596 * - Type "pmc-per-proc", for protecting PMC owner descriptors. 597 * - Type "pmc-leaf", used for all other spin mutexes. 598 */ 599 600 /* 601 * save the cpu binding of the current kthread 602 */ 603 604 static void 605 pmc_save_cpu_binding(struct pmc_binding *pb) 606 { 607 PMCDBG(CPU,BND,2, "%s", "save-cpu"); 608 thread_lock(curthread); 609 pb->pb_bound = sched_is_bound(curthread); 610 pb->pb_cpu = curthread->td_oncpu; 611 thread_unlock(curthread); 612 PMCDBG(CPU,BND,2, "save-cpu cpu=%d", pb->pb_cpu); 613 } 614 615 /* 616 * restore the cpu binding of the current thread 617 */ 618 619 static void 620 pmc_restore_cpu_binding(struct pmc_binding *pb) 621 { 622 PMCDBG(CPU,BND,2, "restore-cpu curcpu=%d restore=%d", 623 curthread->td_oncpu, pb->pb_cpu); 624 thread_lock(curthread); 625 if (pb->pb_bound) 626 sched_bind(curthread, pb->pb_cpu); 627 else 628 sched_unbind(curthread); 629 thread_unlock(curthread); 630 PMCDBG(CPU,BND,2, "%s", "restore-cpu done"); 631 } 632 633 /* 634 * move execution over the specified cpu and bind it there. 635 */ 636 637 static void 638 pmc_select_cpu(int cpu) 639 { 640 KASSERT(cpu >= 0 && cpu < mp_ncpus, 641 ("[pmc,%d] bad cpu number %d", __LINE__, cpu)); 642 643 /* never move to a disabled CPU */ 644 KASSERT(pmc_cpu_is_disabled(cpu) == 0, ("[pmc,%d] selecting " 645 "disabled CPU %d", __LINE__, cpu)); 646 647 PMCDBG(CPU,SEL,2, "select-cpu cpu=%d", cpu); 648 thread_lock(curthread); 649 sched_bind(curthread, cpu); 650 thread_unlock(curthread); 651 652 KASSERT(curthread->td_oncpu == cpu, 653 ("[pmc,%d] CPU not bound [cpu=%d, curr=%d]", __LINE__, 654 cpu, curthread->td_oncpu)); 655 656 PMCDBG(CPU,SEL,2, "select-cpu cpu=%d ok", cpu); 657 } 658 659 /* 660 * Force a context switch. 661 * 662 * We do this by pause'ing for 1 tick -- invoking mi_switch() is not 663 * guaranteed to force a context switch. 664 */ 665 666 static void 667 pmc_force_context_switch(void) 668 { 669 670 pause("pmcctx", 1); 671 } 672 673 /* 674 * Get the file name for an executable. This is a simple wrapper 675 * around vn_fullpath(9). 676 */ 677 678 static void 679 pmc_getfilename(struct vnode *v, char **fullpath, char **freepath) 680 { 681 682 *fullpath = "unknown"; 683 *freepath = NULL; 684 vn_lock(v, LK_CANRECURSE | LK_EXCLUSIVE | LK_RETRY); 685 vn_fullpath(curthread, v, fullpath, freepath); 686 VOP_UNLOCK(v, 0); 687 } 688 689 /* 690 * remove an process owning PMCs 691 */ 692 693 void 694 pmc_remove_owner(struct pmc_owner *po) 695 { 696 struct pmc *pm, *tmp; 697 698 sx_assert(&pmc_sx, SX_XLOCKED); 699 700 PMCDBG(OWN,ORM,1, "remove-owner po=%p", po); 701 702 /* Remove descriptor from the owner hash table */ 703 LIST_REMOVE(po, po_next); 704 705 /* release all owned PMC descriptors */ 706 LIST_FOREACH_SAFE(pm, &po->po_pmcs, pm_next, tmp) { 707 PMCDBG(OWN,ORM,2, "pmc=%p", pm); 708 KASSERT(pm->pm_owner == po, 709 ("[pmc,%d] owner %p != po %p", __LINE__, pm->pm_owner, po)); 710 711 pmc_release_pmc_descriptor(pm); /* will unlink from the list */ 712 } 713 714 KASSERT(po->po_sscount == 0, 715 ("[pmc,%d] SS count not zero", __LINE__)); 716 KASSERT(LIST_EMPTY(&po->po_pmcs), 717 ("[pmc,%d] PMC list not empty", __LINE__)); 718 719 /* de-configure the log file if present */ 720 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 721 pmclog_deconfigure_log(po); 722 } 723 724 /* 725 * remove an owner process record if all conditions are met. 726 */ 727 728 static void 729 pmc_maybe_remove_owner(struct pmc_owner *po) 730 { 731 732 PMCDBG(OWN,OMR,1, "maybe-remove-owner po=%p", po); 733 734 /* 735 * Remove owner record if 736 * - this process does not own any PMCs 737 * - this process has not allocated a system-wide sampling buffer 738 */ 739 740 if (LIST_EMPTY(&po->po_pmcs) && 741 ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0)) { 742 pmc_remove_owner(po); 743 pmc_destroy_owner_descriptor(po); 744 } 745 } 746 747 /* 748 * Add an association between a target process and a PMC. 749 */ 750 751 static void 752 pmc_link_target_process(struct pmc *pm, struct pmc_process *pp) 753 { 754 int ri; 755 struct pmc_target *pt; 756 757 sx_assert(&pmc_sx, SX_XLOCKED); 758 759 KASSERT(pm != NULL && pp != NULL, 760 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 761 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 762 ("[pmc,%d] Attaching a non-process-virtual pmc=%p to pid=%d", 763 __LINE__, pm, pp->pp_proc->p_pid)); 764 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt < ((int) md->pmd_npmc - 1), 765 ("[pmc,%d] Illegal reference count %d for process record %p", 766 __LINE__, pp->pp_refcnt, (void *) pp)); 767 768 ri = PMC_TO_ROWINDEX(pm); 769 770 PMCDBG(PRC,TLK,1, "link-target pmc=%p ri=%d pmc-process=%p", 771 pm, ri, pp); 772 773 #ifdef DEBUG 774 LIST_FOREACH(pt, &pm->pm_targets, pt_next) 775 if (pt->pt_process == pp) 776 KASSERT(0, ("[pmc,%d] pp %p already in pmc %p targets", 777 __LINE__, pp, pm)); 778 #endif 779 780 MALLOC(pt, struct pmc_target *, sizeof(struct pmc_target), 781 M_PMC, M_ZERO|M_WAITOK); 782 783 pt->pt_process = pp; 784 785 LIST_INSERT_HEAD(&pm->pm_targets, pt, pt_next); 786 787 atomic_store_rel_ptr((uintptr_t *)&pp->pp_pmcs[ri].pp_pmc, 788 (uintptr_t)pm); 789 790 if (pm->pm_owner->po_owner == pp->pp_proc) 791 pm->pm_flags |= PMC_F_ATTACHED_TO_OWNER; 792 793 /* 794 * Initialize the per-process values at this row index. 795 */ 796 pp->pp_pmcs[ri].pp_pmcval = PMC_TO_MODE(pm) == PMC_MODE_TS ? 797 pm->pm_sc.pm_reloadcount : 0; 798 799 pp->pp_refcnt++; 800 801 } 802 803 /* 804 * Removes the association between a target process and a PMC. 805 */ 806 807 static void 808 pmc_unlink_target_process(struct pmc *pm, struct pmc_process *pp) 809 { 810 int ri; 811 struct proc *p; 812 struct pmc_target *ptgt; 813 814 sx_assert(&pmc_sx, SX_XLOCKED); 815 816 KASSERT(pm != NULL && pp != NULL, 817 ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); 818 819 KASSERT(pp->pp_refcnt >= 1 && pp->pp_refcnt < (int) md->pmd_npmc, 820 ("[pmc,%d] Illegal ref count %d on process record %p", 821 __LINE__, pp->pp_refcnt, (void *) pp)); 822 823 ri = PMC_TO_ROWINDEX(pm); 824 825 PMCDBG(PRC,TUL,1, "unlink-target pmc=%p ri=%d pmc-process=%p", 826 pm, ri, pp); 827 828 KASSERT(pp->pp_pmcs[ri].pp_pmc == pm, 829 ("[pmc,%d] PMC ri %d mismatch pmc %p pp->[ri] %p", __LINE__, 830 ri, pm, pp->pp_pmcs[ri].pp_pmc)); 831 832 pp->pp_pmcs[ri].pp_pmc = NULL; 833 pp->pp_pmcs[ri].pp_pmcval = (pmc_value_t) 0; 834 835 /* Remove owner-specific flags */ 836 if (pm->pm_owner->po_owner == pp->pp_proc) { 837 pp->pp_flags &= ~PMC_PP_ENABLE_MSR_ACCESS; 838 pm->pm_flags &= ~PMC_F_ATTACHED_TO_OWNER; 839 } 840 841 pp->pp_refcnt--; 842 843 /* Remove the target process from the PMC structure */ 844 LIST_FOREACH(ptgt, &pm->pm_targets, pt_next) 845 if (ptgt->pt_process == pp) 846 break; 847 848 KASSERT(ptgt != NULL, ("[pmc,%d] process %p (pp: %p) not found " 849 "in pmc %p", __LINE__, pp->pp_proc, pp, pm)); 850 851 LIST_REMOVE(ptgt, pt_next); 852 FREE(ptgt, M_PMC); 853 854 /* if the PMC now lacks targets, send the owner a SIGIO */ 855 if (LIST_EMPTY(&pm->pm_targets)) { 856 p = pm->pm_owner->po_owner; 857 PROC_LOCK(p); 858 psignal(p, SIGIO); 859 PROC_UNLOCK(p); 860 861 PMCDBG(PRC,SIG,2, "signalling proc=%p signal=%d", p, 862 SIGIO); 863 } 864 } 865 866 /* 867 * Check if PMC 'pm' may be attached to target process 't'. 868 */ 869 870 static int 871 pmc_can_attach(struct pmc *pm, struct proc *t) 872 { 873 struct proc *o; /* pmc owner */ 874 struct ucred *oc, *tc; /* owner, target credentials */ 875 int decline_attach, i; 876 877 /* 878 * A PMC's owner can always attach that PMC to itself. 879 */ 880 881 if ((o = pm->pm_owner->po_owner) == t) 882 return 0; 883 884 PROC_LOCK(o); 885 oc = o->p_ucred; 886 crhold(oc); 887 PROC_UNLOCK(o); 888 889 PROC_LOCK(t); 890 tc = t->p_ucred; 891 crhold(tc); 892 PROC_UNLOCK(t); 893 894 /* 895 * The effective uid of the PMC owner should match at least one 896 * of the {effective,real,saved} uids of the target process. 897 */ 898 899 decline_attach = oc->cr_uid != tc->cr_uid && 900 oc->cr_uid != tc->cr_svuid && 901 oc->cr_uid != tc->cr_ruid; 902 903 /* 904 * Every one of the target's group ids, must be in the owner's 905 * group list. 906 */ 907 for (i = 0; !decline_attach && i < tc->cr_ngroups; i++) 908 decline_attach = !groupmember(tc->cr_groups[i], oc); 909 910 /* check the read and saved gids too */ 911 if (decline_attach == 0) 912 decline_attach = !groupmember(tc->cr_rgid, oc) || 913 !groupmember(tc->cr_svgid, oc); 914 915 crfree(tc); 916 crfree(oc); 917 918 return !decline_attach; 919 } 920 921 /* 922 * Attach a process to a PMC. 923 */ 924 925 static int 926 pmc_attach_one_process(struct proc *p, struct pmc *pm) 927 { 928 int ri; 929 char *fullpath, *freepath; 930 struct pmc_process *pp; 931 932 sx_assert(&pmc_sx, SX_XLOCKED); 933 934 PMCDBG(PRC,ATT,2, "attach-one pm=%p ri=%d proc=%p (%d, %s)", pm, 935 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 936 937 /* 938 * Locate the process descriptor corresponding to process 'p', 939 * allocating space as needed. 940 * 941 * Verify that rowindex 'pm_rowindex' is free in the process 942 * descriptor. 943 * 944 * If not, allocate space for a descriptor and link the 945 * process descriptor and PMC. 946 */ 947 ri = PMC_TO_ROWINDEX(pm); 948 949 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_ALLOCATE)) == NULL) 950 return ENOMEM; 951 952 if (pp->pp_pmcs[ri].pp_pmc == pm) /* already present at slot [ri] */ 953 return EEXIST; 954 955 if (pp->pp_pmcs[ri].pp_pmc != NULL) 956 return EBUSY; 957 958 pmc_link_target_process(pm, pp); 959 960 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) && 961 (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) == 0) 962 pm->pm_flags |= PMC_F_NEEDS_LOGFILE; 963 964 pm->pm_flags |= PMC_F_ATTACH_DONE; /* mark as attached */ 965 966 /* issue an attach event to a configured log file */ 967 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) { 968 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 969 pmclog_process_pmcattach(pm, p->p_pid, fullpath); 970 if (freepath) 971 FREE(freepath, M_TEMP); 972 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 973 pmc_log_process_mappings(pm->pm_owner, p); 974 } 975 /* mark process as using HWPMCs */ 976 PROC_LOCK(p); 977 p->p_flag |= P_HWPMC; 978 PROC_UNLOCK(p); 979 980 return 0; 981 } 982 983 /* 984 * Attach a process and optionally its children 985 */ 986 987 static int 988 pmc_attach_process(struct proc *p, struct pmc *pm) 989 { 990 int error; 991 struct proc *top; 992 993 sx_assert(&pmc_sx, SX_XLOCKED); 994 995 PMCDBG(PRC,ATT,1, "attach pm=%p ri=%d proc=%p (%d, %s)", pm, 996 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 997 998 999 /* 1000 * If this PMC successfully allowed a GETMSR operation 1001 * in the past, disallow further ATTACHes. 1002 */ 1003 1004 if ((pm->pm_flags & PMC_PP_ENABLE_MSR_ACCESS) != 0) 1005 return EPERM; 1006 1007 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 1008 return pmc_attach_one_process(p, pm); 1009 1010 /* 1011 * Traverse all child processes, attaching them to 1012 * this PMC. 1013 */ 1014 1015 sx_slock(&proctree_lock); 1016 1017 top = p; 1018 1019 for (;;) { 1020 if ((error = pmc_attach_one_process(p, pm)) != 0) 1021 break; 1022 if (!LIST_EMPTY(&p->p_children)) 1023 p = LIST_FIRST(&p->p_children); 1024 else for (;;) { 1025 if (p == top) 1026 goto done; 1027 if (LIST_NEXT(p, p_sibling)) { 1028 p = LIST_NEXT(p, p_sibling); 1029 break; 1030 } 1031 p = p->p_pptr; 1032 } 1033 } 1034 1035 if (error) 1036 (void) pmc_detach_process(top, pm); 1037 1038 done: 1039 sx_sunlock(&proctree_lock); 1040 return error; 1041 } 1042 1043 /* 1044 * Detach a process from a PMC. If there are no other PMCs tracking 1045 * this process, remove the process structure from its hash table. If 1046 * 'flags' contains PMC_FLAG_REMOVE, then free the process structure. 1047 */ 1048 1049 static int 1050 pmc_detach_one_process(struct proc *p, struct pmc *pm, int flags) 1051 { 1052 int ri; 1053 struct pmc_process *pp; 1054 1055 sx_assert(&pmc_sx, SX_XLOCKED); 1056 1057 KASSERT(pm != NULL, 1058 ("[pmc,%d] null pm pointer", __LINE__)); 1059 1060 ri = PMC_TO_ROWINDEX(pm); 1061 1062 PMCDBG(PRC,ATT,2, "detach-one pm=%p ri=%d proc=%p (%d, %s) flags=0x%x", 1063 pm, ri, p, p->p_pid, p->p_comm, flags); 1064 1065 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) 1066 return ESRCH; 1067 1068 if (pp->pp_pmcs[ri].pp_pmc != pm) 1069 return EINVAL; 1070 1071 pmc_unlink_target_process(pm, pp); 1072 1073 /* Issue a detach entry if a log file is configured */ 1074 if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) 1075 pmclog_process_pmcdetach(pm, p->p_pid); 1076 1077 /* 1078 * If there are no PMCs targetting this process, we remove its 1079 * descriptor from the target hash table and unset the P_HWPMC 1080 * flag in the struct proc. 1081 */ 1082 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt < (int) md->pmd_npmc, 1083 ("[pmc,%d] Illegal refcnt %d for process struct %p", 1084 __LINE__, pp->pp_refcnt, pp)); 1085 1086 if (pp->pp_refcnt != 0) /* still a target of some PMC */ 1087 return 0; 1088 1089 pmc_remove_process_descriptor(pp); 1090 1091 if (flags & PMC_FLAG_REMOVE) 1092 FREE(pp, M_PMC); 1093 1094 PROC_LOCK(p); 1095 p->p_flag &= ~P_HWPMC; 1096 PROC_UNLOCK(p); 1097 1098 return 0; 1099 } 1100 1101 /* 1102 * Detach a process and optionally its descendants from a PMC. 1103 */ 1104 1105 static int 1106 pmc_detach_process(struct proc *p, struct pmc *pm) 1107 { 1108 struct proc *top; 1109 1110 sx_assert(&pmc_sx, SX_XLOCKED); 1111 1112 PMCDBG(PRC,ATT,1, "detach pm=%p ri=%d proc=%p (%d, %s)", pm, 1113 PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm); 1114 1115 if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) 1116 return pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); 1117 1118 /* 1119 * Traverse all children, detaching them from this PMC. We 1120 * ignore errors since we could be detaching a PMC from a 1121 * partially attached proc tree. 1122 */ 1123 1124 sx_slock(&proctree_lock); 1125 1126 top = p; 1127 1128 for (;;) { 1129 (void) pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); 1130 1131 if (!LIST_EMPTY(&p->p_children)) 1132 p = LIST_FIRST(&p->p_children); 1133 else for (;;) { 1134 if (p == top) 1135 goto done; 1136 if (LIST_NEXT(p, p_sibling)) { 1137 p = LIST_NEXT(p, p_sibling); 1138 break; 1139 } 1140 p = p->p_pptr; 1141 } 1142 } 1143 1144 done: 1145 sx_sunlock(&proctree_lock); 1146 1147 if (LIST_EMPTY(&pm->pm_targets)) 1148 pm->pm_flags &= ~PMC_F_ATTACH_DONE; 1149 1150 return 0; 1151 } 1152 1153 1154 /* 1155 * Thread context switch IN 1156 */ 1157 1158 static void 1159 pmc_process_csw_in(struct thread *td) 1160 { 1161 int cpu; 1162 unsigned int ri; 1163 struct pmc *pm; 1164 struct proc *p; 1165 struct pmc_cpu *pc; 1166 struct pmc_hw *phw; 1167 struct pmc_process *pp; 1168 pmc_value_t newvalue; 1169 1170 p = td->td_proc; 1171 1172 if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE)) == NULL) 1173 return; 1174 1175 KASSERT(pp->pp_proc == td->td_proc, 1176 ("[pmc,%d] not my thread state", __LINE__)); 1177 1178 critical_enter(); /* no preemption from this point */ 1179 1180 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1181 1182 PMCDBG(CSW,SWI,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1183 p->p_pid, p->p_comm, pp); 1184 1185 KASSERT(cpu >= 0 && cpu < mp_ncpus, 1186 ("[pmc,%d] wierd CPU id %d", __LINE__, cpu)); 1187 1188 pc = pmc_pcpu[cpu]; 1189 1190 for (ri = 0; ri < md->pmd_npmc; ri++) { 1191 1192 if ((pm = pp->pp_pmcs[ri].pp_pmc) == NULL) 1193 continue; 1194 1195 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)), 1196 ("[pmc,%d] Target PMC in non-virtual mode (%d)", 1197 __LINE__, PMC_TO_MODE(pm))); 1198 1199 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1200 ("[pmc,%d] Row index mismatch pmc %d != ri %d", 1201 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1202 1203 /* 1204 * Only PMCs that are marked as 'RUNNING' need 1205 * be placed on hardware. 1206 */ 1207 1208 if (pm->pm_state != PMC_STATE_RUNNING) 1209 continue; 1210 1211 /* increment PMC runcount */ 1212 atomic_add_rel_32(&pm->pm_runcount, 1); 1213 1214 /* configure the HWPMC we are going to use. */ 1215 md->pmd_config_pmc(cpu, ri, pm); 1216 1217 phw = pc->pc_hwpmcs[ri]; 1218 1219 KASSERT(phw != NULL, 1220 ("[pmc,%d] null hw pointer", __LINE__)); 1221 1222 KASSERT(phw->phw_pmc == pm, 1223 ("[pmc,%d] hw->pmc %p != pmc %p", __LINE__, 1224 phw->phw_pmc, pm)); 1225 1226 /* 1227 * Write out saved value and start the PMC. 1228 * 1229 * Sampling PMCs use a per-process value, while 1230 * counting mode PMCs use a per-pmc value that is 1231 * inherited across descendants. 1232 */ 1233 if (PMC_TO_MODE(pm) == PMC_MODE_TS) { 1234 mtx_pool_lock_spin(pmc_mtxpool, pm); 1235 newvalue = PMC_PCPU_SAVED(cpu,ri) = 1236 pp->pp_pmcs[ri].pp_pmcval; 1237 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1238 } else { 1239 KASSERT(PMC_TO_MODE(pm) == PMC_MODE_TC, 1240 ("[pmc,%d] illegal mode=%d", __LINE__, 1241 PMC_TO_MODE(pm))); 1242 mtx_pool_lock_spin(pmc_mtxpool, pm); 1243 newvalue = PMC_PCPU_SAVED(cpu, ri) = 1244 pm->pm_gv.pm_savedvalue; 1245 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1246 } 1247 1248 PMCDBG(CSW,SWI,1,"cpu=%d ri=%d new=%jd", cpu, ri, newvalue); 1249 1250 md->pmd_write_pmc(cpu, ri, newvalue); 1251 md->pmd_start_pmc(cpu, ri); 1252 } 1253 1254 /* 1255 * perform any other architecture/cpu dependent thread 1256 * switch-in actions. 1257 */ 1258 1259 (void) (*md->pmd_switch_in)(pc, pp); 1260 1261 critical_exit(); 1262 1263 } 1264 1265 /* 1266 * Thread context switch OUT. 1267 */ 1268 1269 static void 1270 pmc_process_csw_out(struct thread *td) 1271 { 1272 int cpu; 1273 enum pmc_mode mode; 1274 unsigned int ri; 1275 struct pmc *pm; 1276 struct proc *p; 1277 struct pmc_cpu *pc; 1278 struct pmc_process *pp; 1279 int64_t tmp; 1280 pmc_value_t newvalue; 1281 1282 /* 1283 * Locate our process descriptor; this may be NULL if 1284 * this process is exiting and we have already removed 1285 * the process from the target process table. 1286 * 1287 * Note that due to kernel preemption, multiple 1288 * context switches may happen while the process is 1289 * exiting. 1290 * 1291 * Note also that if the target process cannot be 1292 * found we still need to deconfigure any PMCs that 1293 * are currently running on hardware. 1294 */ 1295 1296 p = td->td_proc; 1297 pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE); 1298 1299 /* 1300 * save PMCs 1301 */ 1302 1303 critical_enter(); 1304 1305 cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ 1306 1307 PMCDBG(CSW,SWO,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, 1308 p->p_pid, p->p_comm, pp); 1309 1310 KASSERT(cpu >= 0 && cpu < mp_ncpus, 1311 ("[pmc,%d wierd CPU id %d", __LINE__, cpu)); 1312 1313 pc = pmc_pcpu[cpu]; 1314 1315 /* 1316 * When a PMC gets unlinked from a target PMC, it will 1317 * be removed from the target's pp_pmc[] array. 1318 * 1319 * However, on a MP system, the target could have been 1320 * executing on another CPU at the time of the unlink. 1321 * So, at context switch OUT time, we need to look at 1322 * the hardware to determine if a PMC is scheduled on 1323 * it. 1324 */ 1325 1326 for (ri = 0; ri < md->pmd_npmc; ri++) { 1327 1328 pm = NULL; 1329 (void) (*md->pmd_get_config)(cpu, ri, &pm); 1330 1331 if (pm == NULL) /* nothing at this row index */ 1332 continue; 1333 1334 mode = PMC_TO_MODE(pm); 1335 if (!PMC_IS_VIRTUAL_MODE(mode)) 1336 continue; /* not a process virtual PMC */ 1337 1338 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 1339 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 1340 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 1341 1342 /* Stop hardware if not already stopped */ 1343 if (pm->pm_stalled == 0) 1344 md->pmd_stop_pmc(cpu, ri); 1345 1346 /* reduce this PMC's runcount */ 1347 atomic_subtract_rel_32(&pm->pm_runcount, 1); 1348 1349 /* 1350 * If this PMC is associated with this process, 1351 * save the reading. 1352 */ 1353 1354 if (pp != NULL && pp->pp_pmcs[ri].pp_pmc != NULL) { 1355 1356 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 1357 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", __LINE__, 1358 pm, ri, pp->pp_pmcs[ri].pp_pmc)); 1359 1360 KASSERT(pp->pp_refcnt > 0, 1361 ("[pmc,%d] pp refcnt = %d", __LINE__, 1362 pp->pp_refcnt)); 1363 1364 md->pmd_read_pmc(cpu, ri, &newvalue); 1365 1366 tmp = newvalue - PMC_PCPU_SAVED(cpu,ri); 1367 1368 PMCDBG(CSW,SWI,1,"cpu=%d ri=%d tmp=%jd", cpu, ri, 1369 tmp); 1370 1371 if (mode == PMC_MODE_TS) { 1372 1373 /* 1374 * For sampling process-virtual PMCs, 1375 * we expect the count to be 1376 * decreasing as the 'value' 1377 * programmed into the PMC is the 1378 * number of events to be seen till 1379 * the next sampling interrupt. 1380 */ 1381 if (tmp < 0) 1382 tmp += pm->pm_sc.pm_reloadcount; 1383 mtx_pool_lock_spin(pmc_mtxpool, pm); 1384 pp->pp_pmcs[ri].pp_pmcval -= tmp; 1385 if ((int64_t) pp->pp_pmcs[ri].pp_pmcval < 0) 1386 pp->pp_pmcs[ri].pp_pmcval += 1387 pm->pm_sc.pm_reloadcount; 1388 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1389 1390 } else { 1391 1392 /* 1393 * For counting process-virtual PMCs, 1394 * we expect the count to be 1395 * increasing monotonically, modulo a 64 1396 * bit wraparound. 1397 */ 1398 KASSERT((int64_t) tmp >= 0, 1399 ("[pmc,%d] negative increment cpu=%d " 1400 "ri=%d newvalue=%jx saved=%jx " 1401 "incr=%jx", __LINE__, cpu, ri, 1402 newvalue, PMC_PCPU_SAVED(cpu,ri), tmp)); 1403 1404 mtx_pool_lock_spin(pmc_mtxpool, pm); 1405 pm->pm_gv.pm_savedvalue += tmp; 1406 pp->pp_pmcs[ri].pp_pmcval += tmp; 1407 mtx_pool_unlock_spin(pmc_mtxpool, pm); 1408 1409 if (pm->pm_flags & PMC_F_LOG_PROCCSW) 1410 pmclog_process_proccsw(pm, pp, tmp); 1411 } 1412 } 1413 1414 /* mark hardware as free */ 1415 md->pmd_config_pmc(cpu, ri, NULL); 1416 } 1417 1418 /* 1419 * perform any other architecture/cpu dependent thread 1420 * switch out functions. 1421 */ 1422 1423 (void) (*md->pmd_switch_out)(pc, pp); 1424 1425 critical_exit(); 1426 } 1427 1428 /* 1429 * Log a KLD operation. 1430 */ 1431 1432 static void 1433 pmc_process_kld_load(struct pmckern_map_in *pkm) 1434 { 1435 struct pmc_owner *po; 1436 1437 sx_assert(&pmc_sx, SX_LOCKED); 1438 1439 /* 1440 * Notify owners of system sampling PMCs about KLD operations. 1441 */ 1442 1443 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1444 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1445 pmclog_process_map_in(po, (pid_t) -1, pkm->pm_address, 1446 (char *) pkm->pm_file); 1447 1448 /* 1449 * TODO: Notify owners of (all) process-sampling PMCs too. 1450 */ 1451 1452 return; 1453 } 1454 1455 static void 1456 pmc_process_kld_unload(struct pmckern_map_out *pkm) 1457 { 1458 struct pmc_owner *po; 1459 1460 sx_assert(&pmc_sx, SX_LOCKED); 1461 1462 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1463 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1464 pmclog_process_map_out(po, (pid_t) -1, 1465 pkm->pm_address, pkm->pm_address + pkm->pm_size); 1466 1467 /* 1468 * TODO: Notify owners of process-sampling PMCs. 1469 */ 1470 } 1471 1472 /* 1473 * A mapping change for a process. 1474 */ 1475 1476 static void 1477 pmc_process_mmap(struct thread *td, struct pmckern_map_in *pkm) 1478 { 1479 int ri; 1480 pid_t pid; 1481 char *fullpath, *freepath; 1482 const struct pmc *pm; 1483 struct pmc_owner *po; 1484 const struct pmc_process *pp; 1485 1486 freepath = fullpath = NULL; 1487 pmc_getfilename((struct vnode *) pkm->pm_file, &fullpath, &freepath); 1488 1489 pid = td->td_proc->p_pid; 1490 1491 /* Inform owners of all system-wide sampling PMCs. */ 1492 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1493 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1494 pmclog_process_map_in(po, pid, pkm->pm_address, fullpath); 1495 1496 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1497 goto done; 1498 1499 /* 1500 * Inform sampling PMC owners tracking this process. 1501 */ 1502 for (ri = 0; ri < md->pmd_npmc; ri++) 1503 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1504 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1505 pmclog_process_map_in(pm->pm_owner, 1506 pid, pkm->pm_address, fullpath); 1507 1508 done: 1509 if (freepath) 1510 FREE(freepath, M_TEMP); 1511 } 1512 1513 1514 /* 1515 * Log an munmap request. 1516 */ 1517 1518 static void 1519 pmc_process_munmap(struct thread *td, struct pmckern_map_out *pkm) 1520 { 1521 int ri; 1522 pid_t pid; 1523 struct pmc_owner *po; 1524 const struct pmc *pm; 1525 const struct pmc_process *pp; 1526 1527 pid = td->td_proc->p_pid; 1528 1529 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1530 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1531 pmclog_process_map_out(po, pid, pkm->pm_address, 1532 pkm->pm_address + pkm->pm_size); 1533 1534 if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL) 1535 return; 1536 1537 for (ri = 0; ri < md->pmd_npmc; ri++) 1538 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL && 1539 PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 1540 pmclog_process_map_out(pm->pm_owner, pid, 1541 pkm->pm_address, pkm->pm_address + pkm->pm_size); 1542 } 1543 1544 /* 1545 * Log mapping information about the kernel. 1546 */ 1547 1548 static void 1549 pmc_log_kernel_mappings(struct pmc *pm) 1550 { 1551 struct pmc_owner *po; 1552 struct pmckern_map_in *km, *kmbase; 1553 1554 sx_assert(&pmc_sx, SX_LOCKED); 1555 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 1556 ("[pmc,%d] non-sampling PMC (%p) desires mapping information", 1557 __LINE__, (void *) pm)); 1558 1559 po = pm->pm_owner; 1560 1561 if (po->po_flags & PMC_PO_INITIAL_MAPPINGS_DONE) 1562 return; 1563 1564 /* 1565 * Log the current set of kernel modules. 1566 */ 1567 kmbase = linker_hwpmc_list_objects(); 1568 for (km = kmbase; km->pm_file != NULL; km++) { 1569 PMCDBG(LOG,REG,1,"%s %p", (char *) km->pm_file, 1570 (void *) km->pm_address); 1571 pmclog_process_map_in(po, (pid_t) -1, km->pm_address, 1572 km->pm_file); 1573 } 1574 FREE(kmbase, M_LINKER); 1575 1576 po->po_flags |= PMC_PO_INITIAL_MAPPINGS_DONE; 1577 } 1578 1579 /* 1580 * Log the mappings for a single process. 1581 */ 1582 1583 static void 1584 pmc_log_process_mappings(struct pmc_owner *po, struct proc *p) 1585 { 1586 } 1587 1588 /* 1589 * Log mappings for all processes in the system. 1590 */ 1591 1592 static void 1593 pmc_log_all_process_mappings(struct pmc_owner *po) 1594 { 1595 struct proc *p, *top; 1596 1597 sx_assert(&pmc_sx, SX_XLOCKED); 1598 1599 if ((p = pfind(1)) == NULL) 1600 panic("[pmc,%d] Cannot find init", __LINE__); 1601 1602 PROC_UNLOCK(p); 1603 1604 sx_slock(&proctree_lock); 1605 1606 top = p; 1607 1608 for (;;) { 1609 pmc_log_process_mappings(po, p); 1610 if (!LIST_EMPTY(&p->p_children)) 1611 p = LIST_FIRST(&p->p_children); 1612 else for (;;) { 1613 if (p == top) 1614 goto done; 1615 if (LIST_NEXT(p, p_sibling)) { 1616 p = LIST_NEXT(p, p_sibling); 1617 break; 1618 } 1619 p = p->p_pptr; 1620 } 1621 } 1622 done: 1623 sx_sunlock(&proctree_lock); 1624 } 1625 1626 /* 1627 * The 'hook' invoked from the kernel proper 1628 */ 1629 1630 1631 #ifdef DEBUG 1632 const char *pmc_hooknames[] = { 1633 /* these strings correspond to PMC_FN_* in <sys/pmckern.h> */ 1634 "", 1635 "EXEC", 1636 "CSW-IN", 1637 "CSW-OUT", 1638 "SAMPLE", 1639 "KLDLOAD", 1640 "KLDUNLOAD", 1641 "MMAP", 1642 "MUNMAP", 1643 "CALLCHAIN" 1644 }; 1645 #endif 1646 1647 static int 1648 pmc_hook_handler(struct thread *td, int function, void *arg) 1649 { 1650 1651 PMCDBG(MOD,PMH,1, "hook td=%p func=%d \"%s\" arg=%p", td, function, 1652 pmc_hooknames[function], arg); 1653 1654 switch (function) 1655 { 1656 1657 /* 1658 * Process exec() 1659 */ 1660 1661 case PMC_FN_PROCESS_EXEC: 1662 { 1663 char *fullpath, *freepath; 1664 unsigned int ri; 1665 int is_using_hwpmcs; 1666 struct pmc *pm; 1667 struct proc *p; 1668 struct pmc_owner *po; 1669 struct pmc_process *pp; 1670 struct pmckern_procexec *pk; 1671 1672 sx_assert(&pmc_sx, SX_XLOCKED); 1673 1674 p = td->td_proc; 1675 pmc_getfilename(p->p_textvp, &fullpath, &freepath); 1676 1677 pk = (struct pmckern_procexec *) arg; 1678 1679 /* Inform owners of SS mode PMCs of the exec event. */ 1680 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 1681 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 1682 pmclog_process_procexec(po, PMC_ID_INVALID, 1683 p->p_pid, pk->pm_entryaddr, fullpath); 1684 1685 PROC_LOCK(p); 1686 is_using_hwpmcs = p->p_flag & P_HWPMC; 1687 PROC_UNLOCK(p); 1688 1689 if (!is_using_hwpmcs) { 1690 if (freepath) 1691 FREE(freepath, M_TEMP); 1692 break; 1693 } 1694 1695 /* 1696 * PMCs are not inherited across an exec(): remove any 1697 * PMCs that this process is the owner of. 1698 */ 1699 1700 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 1701 pmc_remove_owner(po); 1702 pmc_destroy_owner_descriptor(po); 1703 } 1704 1705 /* 1706 * If the process being exec'ed is not the target of any 1707 * PMC, we are done. 1708 */ 1709 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) { 1710 if (freepath) 1711 FREE(freepath, M_TEMP); 1712 break; 1713 } 1714 1715 /* 1716 * Log the exec event to all monitoring owners. Skip 1717 * owners who have already recieved the event because 1718 * they had system sampling PMCs active. 1719 */ 1720 for (ri = 0; ri < md->pmd_npmc; ri++) 1721 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 1722 po = pm->pm_owner; 1723 if (po->po_sscount == 0 && 1724 po->po_flags & PMC_PO_OWNS_LOGFILE) 1725 pmclog_process_procexec(po, pm->pm_id, 1726 p->p_pid, pk->pm_entryaddr, 1727 fullpath); 1728 } 1729 1730 if (freepath) 1731 FREE(freepath, M_TEMP); 1732 1733 1734 PMCDBG(PRC,EXC,1, "exec proc=%p (%d, %s) cred-changed=%d", 1735 p, p->p_pid, p->p_comm, pk->pm_credentialschanged); 1736 1737 if (pk->pm_credentialschanged == 0) /* no change */ 1738 break; 1739 1740 /* 1741 * If the newly exec()'ed process has a different credential 1742 * than before, allow it to be the target of a PMC only if 1743 * the PMC's owner has sufficient priviledge. 1744 */ 1745 1746 for (ri = 0; ri < md->pmd_npmc; ri++) 1747 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) 1748 if (pmc_can_attach(pm, td->td_proc) != 0) 1749 pmc_detach_one_process(td->td_proc, 1750 pm, PMC_FLAG_NONE); 1751 1752 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt < (int) md->pmd_npmc, 1753 ("[pmc,%d] Illegal ref count %d on pp %p", __LINE__, 1754 pp->pp_refcnt, pp)); 1755 1756 /* 1757 * If this process is no longer the target of any 1758 * PMCs, we can remove the process entry and free 1759 * up space. 1760 */ 1761 1762 if (pp->pp_refcnt == 0) { 1763 pmc_remove_process_descriptor(pp); 1764 FREE(pp, M_PMC); 1765 break; 1766 } 1767 1768 } 1769 break; 1770 1771 case PMC_FN_CSW_IN: 1772 pmc_process_csw_in(td); 1773 break; 1774 1775 case PMC_FN_CSW_OUT: 1776 pmc_process_csw_out(td); 1777 break; 1778 1779 /* 1780 * Process accumulated PC samples. 1781 * 1782 * This function is expected to be called by hardclock() for 1783 * each CPU that has accumulated PC samples. 1784 * 1785 * This function is to be executed on the CPU whose samples 1786 * are being processed. 1787 */ 1788 case PMC_FN_DO_SAMPLES: 1789 1790 /* 1791 * Clear the cpu specific bit in the CPU mask before 1792 * do the rest of the processing. If the NMI handler 1793 * gets invoked after the "atomic_clear_int()" call 1794 * below but before "pmc_process_samples()" gets 1795 * around to processing the interrupt, then we will 1796 * come back here at the next hardclock() tick (and 1797 * may find nothing to do if "pmc_process_samples()" 1798 * had already processed the interrupt). We don't 1799 * lose the interrupt sample. 1800 */ 1801 atomic_clear_int(&pmc_cpumask, (1 << PCPU_GET(cpuid))); 1802 pmc_process_samples(PCPU_GET(cpuid)); 1803 break; 1804 1805 1806 case PMC_FN_KLD_LOAD: 1807 sx_assert(&pmc_sx, SX_LOCKED); 1808 pmc_process_kld_load((struct pmckern_map_in *) arg); 1809 break; 1810 1811 case PMC_FN_KLD_UNLOAD: 1812 sx_assert(&pmc_sx, SX_LOCKED); 1813 pmc_process_kld_unload((struct pmckern_map_out *) arg); 1814 break; 1815 1816 case PMC_FN_MMAP: 1817 sx_assert(&pmc_sx, SX_LOCKED); 1818 pmc_process_mmap(td, (struct pmckern_map_in *) arg); 1819 break; 1820 1821 case PMC_FN_MUNMAP: 1822 sx_assert(&pmc_sx, SX_LOCKED); 1823 pmc_process_munmap(td, (struct pmckern_map_out *) arg); 1824 break; 1825 1826 case PMC_FN_USER_CALLCHAIN: 1827 /* 1828 * Record a call chain. 1829 */ 1830 pmc_capture_user_callchain(PCPU_GET(cpuid), 1831 (struct trapframe *) arg); 1832 break; 1833 1834 default: 1835 #ifdef DEBUG 1836 KASSERT(0, ("[pmc,%d] unknown hook %d\n", __LINE__, function)); 1837 #endif 1838 break; 1839 1840 } 1841 1842 return 0; 1843 } 1844 1845 /* 1846 * allocate a 'struct pmc_owner' descriptor in the owner hash table. 1847 */ 1848 1849 static struct pmc_owner * 1850 pmc_allocate_owner_descriptor(struct proc *p) 1851 { 1852 uint32_t hindex; 1853 struct pmc_owner *po; 1854 struct pmc_ownerhash *poh; 1855 1856 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 1857 poh = &pmc_ownerhash[hindex]; 1858 1859 /* allocate space for N pointers and one descriptor struct */ 1860 MALLOC(po, struct pmc_owner *, sizeof(struct pmc_owner), 1861 M_PMC, M_ZERO|M_WAITOK); 1862 1863 po->po_sscount = po->po_error = po->po_flags = 0; 1864 po->po_file = NULL; 1865 po->po_owner = p; 1866 po->po_kthread = NULL; 1867 LIST_INIT(&po->po_pmcs); 1868 LIST_INSERT_HEAD(poh, po, po_next); /* insert into hash table */ 1869 1870 TAILQ_INIT(&po->po_logbuffers); 1871 mtx_init(&po->po_mtx, "pmc-owner-mtx", "pmc-per-proc", MTX_SPIN); 1872 1873 PMCDBG(OWN,ALL,1, "allocate-owner proc=%p (%d, %s) pmc-owner=%p", 1874 p, p->p_pid, p->p_comm, po); 1875 1876 return po; 1877 } 1878 1879 static void 1880 pmc_destroy_owner_descriptor(struct pmc_owner *po) 1881 { 1882 1883 PMCDBG(OWN,REL,1, "destroy-owner po=%p proc=%p (%d, %s)", 1884 po, po->po_owner, po->po_owner->p_pid, po->po_owner->p_comm); 1885 1886 mtx_destroy(&po->po_mtx); 1887 FREE(po, M_PMC); 1888 } 1889 1890 /* 1891 * find the descriptor corresponding to process 'p', adding or removing it 1892 * as specified by 'mode'. 1893 */ 1894 1895 static struct pmc_process * 1896 pmc_find_process_descriptor(struct proc *p, uint32_t mode) 1897 { 1898 uint32_t hindex; 1899 struct pmc_process *pp, *ppnew; 1900 struct pmc_processhash *pph; 1901 1902 hindex = PMC_HASH_PTR(p, pmc_processhashmask); 1903 pph = &pmc_processhash[hindex]; 1904 1905 ppnew = NULL; 1906 1907 /* 1908 * Pre-allocate memory in the FIND_ALLOCATE case since we 1909 * cannot call malloc(9) once we hold a spin lock. 1910 */ 1911 1912 if (mode & PMC_FLAG_ALLOCATE) { 1913 /* allocate additional space for 'n' pmc pointers */ 1914 MALLOC(ppnew, struct pmc_process *, 1915 sizeof(struct pmc_process) + md->pmd_npmc * 1916 sizeof(struct pmc_targetstate), M_PMC, M_ZERO|M_WAITOK); 1917 } 1918 1919 mtx_lock_spin(&pmc_processhash_mtx); 1920 LIST_FOREACH(pp, pph, pp_next) 1921 if (pp->pp_proc == p) 1922 break; 1923 1924 if ((mode & PMC_FLAG_REMOVE) && pp != NULL) 1925 LIST_REMOVE(pp, pp_next); 1926 1927 if ((mode & PMC_FLAG_ALLOCATE) && pp == NULL && 1928 ppnew != NULL) { 1929 ppnew->pp_proc = p; 1930 LIST_INSERT_HEAD(pph, ppnew, pp_next); 1931 pp = ppnew; 1932 ppnew = NULL; 1933 } 1934 mtx_unlock_spin(&pmc_processhash_mtx); 1935 1936 if (pp != NULL && ppnew != NULL) 1937 FREE(ppnew, M_PMC); 1938 1939 return pp; 1940 } 1941 1942 /* 1943 * remove a process descriptor from the process hash table. 1944 */ 1945 1946 static void 1947 pmc_remove_process_descriptor(struct pmc_process *pp) 1948 { 1949 KASSERT(pp->pp_refcnt == 0, 1950 ("[pmc,%d] Removing process descriptor %p with count %d", 1951 __LINE__, pp, pp->pp_refcnt)); 1952 1953 mtx_lock_spin(&pmc_processhash_mtx); 1954 LIST_REMOVE(pp, pp_next); 1955 mtx_unlock_spin(&pmc_processhash_mtx); 1956 } 1957 1958 1959 /* 1960 * find an owner descriptor corresponding to proc 'p' 1961 */ 1962 1963 static struct pmc_owner * 1964 pmc_find_owner_descriptor(struct proc *p) 1965 { 1966 uint32_t hindex; 1967 struct pmc_owner *po; 1968 struct pmc_ownerhash *poh; 1969 1970 hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); 1971 poh = &pmc_ownerhash[hindex]; 1972 1973 po = NULL; 1974 LIST_FOREACH(po, poh, po_next) 1975 if (po->po_owner == p) 1976 break; 1977 1978 PMCDBG(OWN,FND,1, "find-owner proc=%p (%d, %s) hindex=0x%x -> " 1979 "pmc-owner=%p", p, p->p_pid, p->p_comm, hindex, po); 1980 1981 return po; 1982 } 1983 1984 /* 1985 * pmc_allocate_pmc_descriptor 1986 * 1987 * Allocate a pmc descriptor and initialize its 1988 * fields. 1989 */ 1990 1991 static struct pmc * 1992 pmc_allocate_pmc_descriptor(void) 1993 { 1994 struct pmc *pmc; 1995 1996 MALLOC(pmc, struct pmc *, sizeof(struct pmc), M_PMC, M_ZERO|M_WAITOK); 1997 1998 if (pmc != NULL) { 1999 pmc->pm_owner = NULL; 2000 LIST_INIT(&pmc->pm_targets); 2001 } 2002 2003 PMCDBG(PMC,ALL,1, "allocate-pmc -> pmc=%p", pmc); 2004 2005 return pmc; 2006 } 2007 2008 /* 2009 * Destroy a pmc descriptor. 2010 */ 2011 2012 static void 2013 pmc_destroy_pmc_descriptor(struct pmc *pm) 2014 { 2015 (void) pm; 2016 2017 #ifdef DEBUG 2018 KASSERT(pm->pm_state == PMC_STATE_DELETED || 2019 pm->pm_state == PMC_STATE_FREE, 2020 ("[pmc,%d] destroying non-deleted PMC", __LINE__)); 2021 KASSERT(LIST_EMPTY(&pm->pm_targets), 2022 ("[pmc,%d] destroying pmc with targets", __LINE__)); 2023 KASSERT(pm->pm_owner == NULL, 2024 ("[pmc,%d] destroying pmc attached to an owner", __LINE__)); 2025 KASSERT(pm->pm_runcount == 0, 2026 ("[pmc,%d] pmc has non-zero run count %d", __LINE__, 2027 pm->pm_runcount)); 2028 #endif 2029 } 2030 2031 static void 2032 pmc_wait_for_pmc_idle(struct pmc *pm) 2033 { 2034 #ifdef DEBUG 2035 volatile int maxloop; 2036 2037 maxloop = 100 * mp_ncpus; 2038 #endif 2039 2040 /* 2041 * Loop (with a forced context switch) till the PMC's runcount 2042 * comes down to zero. 2043 */ 2044 while (atomic_load_acq_32(&pm->pm_runcount) > 0) { 2045 #ifdef DEBUG 2046 maxloop--; 2047 KASSERT(maxloop > 0, 2048 ("[pmc,%d] (ri%d, rc%d) waiting too long for " 2049 "pmc to be free", __LINE__, 2050 PMC_TO_ROWINDEX(pm), pm->pm_runcount)); 2051 #endif 2052 pmc_force_context_switch(); 2053 } 2054 } 2055 2056 /* 2057 * This function does the following things: 2058 * 2059 * - detaches the PMC from hardware 2060 * - unlinks all target threads that were attached to it 2061 * - removes the PMC from its owner's list 2062 * - destroy's the PMC private mutex 2063 * 2064 * Once this function completes, the given pmc pointer can be safely 2065 * FREE'd by the caller. 2066 */ 2067 2068 static void 2069 pmc_release_pmc_descriptor(struct pmc *pm) 2070 { 2071 u_int ri, cpu; 2072 enum pmc_mode mode; 2073 struct pmc_hw *phw; 2074 struct pmc_owner *po; 2075 struct pmc_process *pp; 2076 struct pmc_target *ptgt, *tmp; 2077 struct pmc_binding pb; 2078 2079 sx_assert(&pmc_sx, SX_XLOCKED); 2080 2081 KASSERT(pm, ("[pmc,%d] null pmc", __LINE__)); 2082 2083 ri = PMC_TO_ROWINDEX(pm); 2084 mode = PMC_TO_MODE(pm); 2085 2086 PMCDBG(PMC,REL,1, "release-pmc pmc=%p ri=%d mode=%d", pm, ri, 2087 mode); 2088 2089 /* 2090 * First, we take the PMC off hardware. 2091 */ 2092 cpu = 0; 2093 if (PMC_IS_SYSTEM_MODE(mode)) { 2094 2095 /* 2096 * A system mode PMC runs on a specific CPU. Switch 2097 * to this CPU and turn hardware off. 2098 */ 2099 pmc_save_cpu_binding(&pb); 2100 2101 cpu = PMC_TO_CPU(pm); 2102 2103 pmc_select_cpu(cpu); 2104 2105 /* switch off non-stalled CPUs */ 2106 if (pm->pm_state == PMC_STATE_RUNNING && 2107 pm->pm_stalled == 0) { 2108 2109 phw = pmc_pcpu[cpu]->pc_hwpmcs[ri]; 2110 2111 KASSERT(phw->phw_pmc == pm, 2112 ("[pmc, %d] pmc ptr ri(%d) hw(%p) pm(%p)", 2113 __LINE__, ri, phw->phw_pmc, pm)); 2114 PMCDBG(PMC,REL,2, "stopping cpu=%d ri=%d", cpu, ri); 2115 2116 critical_enter(); 2117 md->pmd_stop_pmc(cpu, ri); 2118 critical_exit(); 2119 } 2120 2121 PMCDBG(PMC,REL,2, "decfg cpu=%d ri=%d", cpu, ri); 2122 2123 critical_enter(); 2124 md->pmd_config_pmc(cpu, ri, NULL); 2125 critical_exit(); 2126 2127 /* adjust the global and process count of SS mode PMCs */ 2128 if (mode == PMC_MODE_SS && pm->pm_state == PMC_STATE_RUNNING) { 2129 po = pm->pm_owner; 2130 po->po_sscount--; 2131 if (po->po_sscount == 0) { 2132 atomic_subtract_rel_int(&pmc_ss_count, 1); 2133 LIST_REMOVE(po, po_ssnext); 2134 } 2135 } 2136 2137 pm->pm_state = PMC_STATE_DELETED; 2138 2139 pmc_restore_cpu_binding(&pb); 2140 2141 /* 2142 * We could have references to this PMC structure in 2143 * the per-cpu sample queues. Wait for the queue to 2144 * drain. 2145 */ 2146 pmc_wait_for_pmc_idle(pm); 2147 2148 } else if (PMC_IS_VIRTUAL_MODE(mode)) { 2149 2150 /* 2151 * A virtual PMC could be running on multiple CPUs at 2152 * a given instant. 2153 * 2154 * By marking its state as DELETED, we ensure that 2155 * this PMC is never further scheduled on hardware. 2156 * 2157 * Then we wait till all CPUs are done with this PMC. 2158 */ 2159 pm->pm_state = PMC_STATE_DELETED; 2160 2161 2162 /* Wait for the PMCs runcount to come to zero. */ 2163 pmc_wait_for_pmc_idle(pm); 2164 2165 /* 2166 * At this point the PMC is off all CPUs and cannot be 2167 * freshly scheduled onto a CPU. It is now safe to 2168 * unlink all targets from this PMC. If a 2169 * process-record's refcount falls to zero, we remove 2170 * it from the hash table. The module-wide SX lock 2171 * protects us from races. 2172 */ 2173 LIST_FOREACH_SAFE(ptgt, &pm->pm_targets, pt_next, tmp) { 2174 pp = ptgt->pt_process; 2175 pmc_unlink_target_process(pm, pp); /* frees 'ptgt' */ 2176 2177 PMCDBG(PMC,REL,3, "pp->refcnt=%d", pp->pp_refcnt); 2178 2179 /* 2180 * If the target process record shows that no 2181 * PMCs are attached to it, reclaim its space. 2182 */ 2183 2184 if (pp->pp_refcnt == 0) { 2185 pmc_remove_process_descriptor(pp); 2186 FREE(pp, M_PMC); 2187 } 2188 } 2189 2190 cpu = curthread->td_oncpu; /* setup cpu for pmd_release() */ 2191 2192 } 2193 2194 /* 2195 * Release any MD resources 2196 */ 2197 2198 (void) md->pmd_release_pmc(cpu, ri, pm); 2199 2200 /* 2201 * Update row disposition 2202 */ 2203 2204 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) 2205 PMC_UNMARK_ROW_STANDALONE(ri); 2206 else 2207 PMC_UNMARK_ROW_THREAD(ri); 2208 2209 /* unlink from the owner's list */ 2210 if (pm->pm_owner) { 2211 LIST_REMOVE(pm, pm_next); 2212 pm->pm_owner = NULL; 2213 } 2214 2215 pmc_destroy_pmc_descriptor(pm); 2216 } 2217 2218 /* 2219 * Register an owner and a pmc. 2220 */ 2221 2222 static int 2223 pmc_register_owner(struct proc *p, struct pmc *pmc) 2224 { 2225 struct pmc_owner *po; 2226 2227 sx_assert(&pmc_sx, SX_XLOCKED); 2228 2229 if ((po = pmc_find_owner_descriptor(p)) == NULL) 2230 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) 2231 return ENOMEM; 2232 2233 KASSERT(pmc->pm_owner == NULL, 2234 ("[pmc,%d] attempting to own an initialized PMC", __LINE__)); 2235 pmc->pm_owner = po; 2236 2237 LIST_INSERT_HEAD(&po->po_pmcs, pmc, pm_next); 2238 2239 PROC_LOCK(p); 2240 p->p_flag |= P_HWPMC; 2241 PROC_UNLOCK(p); 2242 2243 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 2244 pmclog_process_pmcallocate(pmc); 2245 2246 PMCDBG(PMC,REG,1, "register-owner pmc-owner=%p pmc=%p", 2247 po, pmc); 2248 2249 return 0; 2250 } 2251 2252 /* 2253 * Return the current row disposition: 2254 * == 0 => FREE 2255 * > 0 => PROCESS MODE 2256 * < 0 => SYSTEM MODE 2257 */ 2258 2259 int 2260 pmc_getrowdisp(int ri) 2261 { 2262 return pmc_pmcdisp[ri]; 2263 } 2264 2265 /* 2266 * Check if a PMC at row index 'ri' can be allocated to the current 2267 * process. 2268 * 2269 * Allocation can fail if: 2270 * - the current process is already being profiled by a PMC at index 'ri', 2271 * attached to it via OP_PMCATTACH. 2272 * - the current process has already allocated a PMC at index 'ri' 2273 * via OP_ALLOCATE. 2274 */ 2275 2276 static int 2277 pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, int cpu) 2278 { 2279 enum pmc_mode mode; 2280 struct pmc *pm; 2281 struct pmc_owner *po; 2282 struct pmc_process *pp; 2283 2284 PMCDBG(PMC,ALR,1, "can-allocate-rowindex proc=%p (%d, %s) ri=%d " 2285 "cpu=%d", p, p->p_pid, p->p_comm, ri, cpu); 2286 2287 /* 2288 * We shouldn't have already allocated a process-mode PMC at 2289 * row index 'ri'. 2290 * 2291 * We shouldn't have allocated a system-wide PMC on the same 2292 * CPU and same RI. 2293 */ 2294 if ((po = pmc_find_owner_descriptor(p)) != NULL) 2295 LIST_FOREACH(pm, &po->po_pmcs, pm_next) { 2296 if (PMC_TO_ROWINDEX(pm) == ri) { 2297 mode = PMC_TO_MODE(pm); 2298 if (PMC_IS_VIRTUAL_MODE(mode)) 2299 return EEXIST; 2300 if (PMC_IS_SYSTEM_MODE(mode) && 2301 (int) PMC_TO_CPU(pm) == cpu) 2302 return EEXIST; 2303 } 2304 } 2305 2306 /* 2307 * We also shouldn't be the target of any PMC at this index 2308 * since otherwise a PMC_ATTACH to ourselves will fail. 2309 */ 2310 if ((pp = pmc_find_process_descriptor(p, 0)) != NULL) 2311 if (pp->pp_pmcs[ri].pp_pmc) 2312 return EEXIST; 2313 2314 PMCDBG(PMC,ALR,2, "can-allocate-rowindex proc=%p (%d, %s) ri=%d ok", 2315 p, p->p_pid, p->p_comm, ri); 2316 2317 return 0; 2318 } 2319 2320 /* 2321 * Check if a given PMC at row index 'ri' can be currently used in 2322 * mode 'mode'. 2323 */ 2324 2325 static int 2326 pmc_can_allocate_row(int ri, enum pmc_mode mode) 2327 { 2328 enum pmc_disp disp; 2329 2330 sx_assert(&pmc_sx, SX_XLOCKED); 2331 2332 PMCDBG(PMC,ALR,1, "can-allocate-row ri=%d mode=%d", ri, mode); 2333 2334 if (PMC_IS_SYSTEM_MODE(mode)) 2335 disp = PMC_DISP_STANDALONE; 2336 else 2337 disp = PMC_DISP_THREAD; 2338 2339 /* 2340 * check disposition for PMC row 'ri': 2341 * 2342 * Expected disposition Row-disposition Result 2343 * 2344 * STANDALONE STANDALONE or FREE proceed 2345 * STANDALONE THREAD fail 2346 * THREAD THREAD or FREE proceed 2347 * THREAD STANDALONE fail 2348 */ 2349 2350 if (!PMC_ROW_DISP_IS_FREE(ri) && 2351 !(disp == PMC_DISP_THREAD && PMC_ROW_DISP_IS_THREAD(ri)) && 2352 !(disp == PMC_DISP_STANDALONE && PMC_ROW_DISP_IS_STANDALONE(ri))) 2353 return EBUSY; 2354 2355 /* 2356 * All OK 2357 */ 2358 2359 PMCDBG(PMC,ALR,2, "can-allocate-row ri=%d mode=%d ok", ri, mode); 2360 2361 return 0; 2362 2363 } 2364 2365 /* 2366 * Find a PMC descriptor with user handle 'pmcid' for thread 'td'. 2367 */ 2368 2369 static struct pmc * 2370 pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, pmc_id_t pmcid) 2371 { 2372 struct pmc *pm; 2373 2374 KASSERT(PMC_ID_TO_ROWINDEX(pmcid) < md->pmd_npmc, 2375 ("[pmc,%d] Illegal pmc index %d (max %d)", __LINE__, 2376 PMC_ID_TO_ROWINDEX(pmcid), md->pmd_npmc)); 2377 2378 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 2379 if (pm->pm_id == pmcid) 2380 return pm; 2381 2382 return NULL; 2383 } 2384 2385 static int 2386 pmc_find_pmc(pmc_id_t pmcid, struct pmc **pmc) 2387 { 2388 2389 struct pmc *pm; 2390 struct pmc_owner *po; 2391 2392 PMCDBG(PMC,FND,1, "find-pmc id=%d", pmcid); 2393 2394 if ((po = pmc_find_owner_descriptor(curthread->td_proc)) == NULL) 2395 return ESRCH; 2396 2397 if ((pm = pmc_find_pmc_descriptor_in_process(po, pmcid)) == NULL) 2398 return EINVAL; 2399 2400 PMCDBG(PMC,FND,2, "find-pmc id=%d -> pmc=%p", pmcid, pm); 2401 2402 *pmc = pm; 2403 return 0; 2404 } 2405 2406 /* 2407 * Start a PMC. 2408 */ 2409 2410 static int 2411 pmc_start(struct pmc *pm) 2412 { 2413 int error, cpu, ri; 2414 enum pmc_mode mode; 2415 struct pmc_owner *po; 2416 struct pmc_binding pb; 2417 2418 KASSERT(pm != NULL, 2419 ("[pmc,%d] null pm", __LINE__)); 2420 2421 mode = PMC_TO_MODE(pm); 2422 ri = PMC_TO_ROWINDEX(pm); 2423 error = 0; 2424 2425 PMCDBG(PMC,OPS,1, "start pmc=%p mode=%d ri=%d", pm, mode, ri); 2426 2427 po = pm->pm_owner; 2428 2429 /* 2430 * Disallow PMCSTART if a logfile is required but has not been 2431 * configured yet. 2432 */ 2433 if ((pm->pm_flags & PMC_F_NEEDS_LOGFILE) && 2434 (po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) 2435 return EDOOFUS; /* programming error */ 2436 2437 /* 2438 * If this is a sampling mode PMC, log mapping information for 2439 * the kernel modules that are currently loaded. 2440 */ 2441 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 2442 pmc_log_kernel_mappings(pm); 2443 2444 if (PMC_IS_VIRTUAL_MODE(mode)) { 2445 2446 /* 2447 * If a PMCATTACH has never been done on this PMC, 2448 * attach it to its owner process. 2449 */ 2450 2451 if (LIST_EMPTY(&pm->pm_targets)) 2452 error = (pm->pm_flags & PMC_F_ATTACH_DONE) ? ESRCH : 2453 pmc_attach_process(po->po_owner, pm); 2454 2455 /* 2456 * If the PMC is attached to its owner, then force a context 2457 * switch to ensure that the MD state gets set correctly. 2458 */ 2459 2460 if (error == 0) { 2461 pm->pm_state = PMC_STATE_RUNNING; 2462 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) 2463 pmc_force_context_switch(); 2464 } 2465 2466 return error; 2467 } 2468 2469 2470 /* 2471 * A system-wide PMC. 2472 * 2473 * Add the owner to the global list if this is a system-wide 2474 * sampling PMC. 2475 */ 2476 2477 if (mode == PMC_MODE_SS) { 2478 if (po->po_sscount == 0) { 2479 LIST_INSERT_HEAD(&pmc_ss_owners, po, po_ssnext); 2480 atomic_add_rel_int(&pmc_ss_count, 1); 2481 PMCDBG(PMC,OPS,1, "po=%p in global list", po); 2482 } 2483 po->po_sscount++; 2484 } 2485 2486 /* Log mapping information for all processes in the system. */ 2487 pmc_log_all_process_mappings(po); 2488 2489 /* 2490 * Move to the CPU associated with this 2491 * PMC, and start the hardware. 2492 */ 2493 2494 pmc_save_cpu_binding(&pb); 2495 2496 cpu = PMC_TO_CPU(pm); 2497 2498 if (pmc_cpu_is_disabled(cpu)) 2499 return ENXIO; 2500 2501 pmc_select_cpu(cpu); 2502 2503 /* 2504 * global PMCs are configured at allocation time 2505 * so write out the initial value and start the PMC. 2506 */ 2507 2508 pm->pm_state = PMC_STATE_RUNNING; 2509 2510 critical_enter(); 2511 if ((error = md->pmd_write_pmc(cpu, ri, 2512 PMC_IS_SAMPLING_MODE(mode) ? 2513 pm->pm_sc.pm_reloadcount : 2514 pm->pm_sc.pm_initial)) == 0) 2515 error = md->pmd_start_pmc(cpu, ri); 2516 critical_exit(); 2517 2518 pmc_restore_cpu_binding(&pb); 2519 2520 return error; 2521 } 2522 2523 /* 2524 * Stop a PMC. 2525 */ 2526 2527 static int 2528 pmc_stop(struct pmc *pm) 2529 { 2530 int cpu, error, ri; 2531 struct pmc_owner *po; 2532 struct pmc_binding pb; 2533 2534 KASSERT(pm != NULL, ("[pmc,%d] null pmc", __LINE__)); 2535 2536 PMCDBG(PMC,OPS,1, "stop pmc=%p mode=%d ri=%d", pm, 2537 PMC_TO_MODE(pm), PMC_TO_ROWINDEX(pm)); 2538 2539 pm->pm_state = PMC_STATE_STOPPED; 2540 2541 /* 2542 * If the PMC is a virtual mode one, changing the state to 2543 * non-RUNNING is enough to ensure that the PMC never gets 2544 * scheduled. 2545 * 2546 * If this PMC is current running on a CPU, then it will 2547 * handled correctly at the time its target process is context 2548 * switched out. 2549 */ 2550 2551 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 2552 return 0; 2553 2554 /* 2555 * A system-mode PMC. Move to the CPU associated with 2556 * this PMC, and stop the hardware. We update the 2557 * 'initial count' so that a subsequent PMCSTART will 2558 * resume counting from the current hardware count. 2559 */ 2560 2561 pmc_save_cpu_binding(&pb); 2562 2563 cpu = PMC_TO_CPU(pm); 2564 2565 KASSERT(cpu >= 0 && cpu < mp_ncpus, 2566 ("[pmc,%d] illegal cpu=%d", __LINE__, cpu)); 2567 2568 if (pmc_cpu_is_disabled(cpu)) 2569 return ENXIO; 2570 2571 pmc_select_cpu(cpu); 2572 2573 ri = PMC_TO_ROWINDEX(pm); 2574 2575 critical_enter(); 2576 if ((error = md->pmd_stop_pmc(cpu, ri)) == 0) 2577 error = md->pmd_read_pmc(cpu, ri, &pm->pm_sc.pm_initial); 2578 critical_exit(); 2579 2580 pmc_restore_cpu_binding(&pb); 2581 2582 po = pm->pm_owner; 2583 2584 /* remove this owner from the global list of SS PMC owners */ 2585 if (PMC_TO_MODE(pm) == PMC_MODE_SS) { 2586 po->po_sscount--; 2587 if (po->po_sscount == 0) { 2588 atomic_subtract_rel_int(&pmc_ss_count, 1); 2589 LIST_REMOVE(po, po_ssnext); 2590 PMCDBG(PMC,OPS,2,"po=%p removed from global list", po); 2591 } 2592 } 2593 2594 return error; 2595 } 2596 2597 2598 #ifdef DEBUG 2599 static const char *pmc_op_to_name[] = { 2600 #undef __PMC_OP 2601 #define __PMC_OP(N, D) #N , 2602 __PMC_OPS() 2603 NULL 2604 }; 2605 #endif 2606 2607 /* 2608 * The syscall interface 2609 */ 2610 2611 #define PMC_GET_SX_XLOCK(...) do { \ 2612 sx_xlock(&pmc_sx); \ 2613 if (pmc_hook == NULL) { \ 2614 sx_xunlock(&pmc_sx); \ 2615 return __VA_ARGS__; \ 2616 } \ 2617 } while (0) 2618 2619 #define PMC_DOWNGRADE_SX() do { \ 2620 sx_downgrade(&pmc_sx); \ 2621 is_sx_downgraded = 1; \ 2622 } while (0) 2623 2624 static int 2625 pmc_syscall_handler(struct thread *td, void *syscall_args) 2626 { 2627 int error, is_sx_downgraded, op; 2628 struct pmc_syscall_args *c; 2629 void *arg; 2630 2631 PMC_GET_SX_XLOCK(ENOSYS); 2632 2633 DROP_GIANT(); 2634 2635 is_sx_downgraded = 0; 2636 2637 c = (struct pmc_syscall_args *) syscall_args; 2638 2639 op = c->pmop_code; 2640 arg = c->pmop_data; 2641 2642 PMCDBG(MOD,PMS,1, "syscall op=%d \"%s\" arg=%p", op, 2643 pmc_op_to_name[op], arg); 2644 2645 error = 0; 2646 atomic_add_int(&pmc_stats.pm_syscalls, 1); 2647 2648 switch(op) 2649 { 2650 2651 2652 /* 2653 * Configure a log file. 2654 * 2655 * XXX This OP will be reworked. 2656 */ 2657 2658 case PMC_OP_CONFIGURELOG: 2659 { 2660 struct proc *p; 2661 struct pmc *pm; 2662 struct pmc_owner *po; 2663 struct pmc_op_configurelog cl; 2664 2665 sx_assert(&pmc_sx, SX_XLOCKED); 2666 2667 if ((error = copyin(arg, &cl, sizeof(cl))) != 0) 2668 break; 2669 2670 /* mark this process as owning a log file */ 2671 p = td->td_proc; 2672 if ((po = pmc_find_owner_descriptor(p)) == NULL) 2673 if ((po = pmc_allocate_owner_descriptor(p)) == NULL) { 2674 error = ENOMEM; 2675 break; 2676 } 2677 2678 /* 2679 * If a valid fd was passed in, try to configure that, 2680 * otherwise if 'fd' was less than zero and there was 2681 * a log file configured, flush its buffers and 2682 * de-configure it. 2683 */ 2684 if (cl.pm_logfd >= 0) 2685 error = pmclog_configure_log(po, cl.pm_logfd); 2686 else if (po->po_flags & PMC_PO_OWNS_LOGFILE) { 2687 pmclog_process_closelog(po); 2688 error = pmclog_flush(po); 2689 if (error == 0) { 2690 LIST_FOREACH(pm, &po->po_pmcs, pm_next) 2691 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 2692 pm->pm_state == PMC_STATE_RUNNING) 2693 pmc_stop(pm); 2694 error = pmclog_deconfigure_log(po); 2695 } 2696 } else 2697 error = EINVAL; 2698 2699 if (error) 2700 break; 2701 } 2702 break; 2703 2704 2705 /* 2706 * Flush a log file. 2707 */ 2708 2709 case PMC_OP_FLUSHLOG: 2710 { 2711 struct pmc_owner *po; 2712 2713 sx_assert(&pmc_sx, SX_XLOCKED); 2714 2715 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 2716 error = EINVAL; 2717 break; 2718 } 2719 2720 error = pmclog_flush(po); 2721 } 2722 break; 2723 2724 /* 2725 * Retrieve hardware configuration. 2726 */ 2727 2728 case PMC_OP_GETCPUINFO: /* CPU information */ 2729 { 2730 struct pmc_op_getcpuinfo gci; 2731 2732 gci.pm_cputype = md->pmd_cputype; 2733 gci.pm_ncpu = mp_ncpus; 2734 gci.pm_npmc = md->pmd_npmc; 2735 gci.pm_nclass = md->pmd_nclass; 2736 bcopy(md->pmd_classes, &gci.pm_classes, 2737 sizeof(gci.pm_classes)); 2738 error = copyout(&gci, arg, sizeof(gci)); 2739 } 2740 break; 2741 2742 2743 /* 2744 * Get module statistics 2745 */ 2746 2747 case PMC_OP_GETDRIVERSTATS: 2748 { 2749 struct pmc_op_getdriverstats gms; 2750 2751 bcopy(&pmc_stats, &gms, sizeof(gms)); 2752 error = copyout(&gms, arg, sizeof(gms)); 2753 } 2754 break; 2755 2756 2757 /* 2758 * Retrieve module version number 2759 */ 2760 2761 case PMC_OP_GETMODULEVERSION: 2762 { 2763 uint32_t cv, modv; 2764 2765 /* retrieve the client's idea of the ABI version */ 2766 if ((error = copyin(arg, &cv, sizeof(uint32_t))) != 0) 2767 break; 2768 /* don't service clients newer than our driver */ 2769 modv = PMC_VERSION; 2770 if ((cv & 0xFFFF0000) > (modv & 0xFFFF0000)) { 2771 error = EPROGMISMATCH; 2772 break; 2773 } 2774 error = copyout(&modv, arg, sizeof(int)); 2775 } 2776 break; 2777 2778 2779 /* 2780 * Retrieve the state of all the PMCs on a given 2781 * CPU. 2782 */ 2783 2784 case PMC_OP_GETPMCINFO: 2785 { 2786 uint32_t cpu, n, npmc; 2787 size_t pmcinfo_size; 2788 struct pmc *pm; 2789 struct pmc_info *p, *pmcinfo; 2790 struct pmc_op_getpmcinfo *gpi; 2791 struct pmc_owner *po; 2792 struct pmc_binding pb; 2793 2794 PMC_DOWNGRADE_SX(); 2795 2796 gpi = (struct pmc_op_getpmcinfo *) arg; 2797 2798 if ((error = copyin(&gpi->pm_cpu, &cpu, sizeof(cpu))) != 0) 2799 break; 2800 2801 if (cpu >= (unsigned int) mp_ncpus) { 2802 error = EINVAL; 2803 break; 2804 } 2805 2806 if (pmc_cpu_is_disabled(cpu)) { 2807 error = ENXIO; 2808 break; 2809 } 2810 2811 /* switch to CPU 'cpu' */ 2812 pmc_save_cpu_binding(&pb); 2813 pmc_select_cpu(cpu); 2814 2815 npmc = md->pmd_npmc; 2816 2817 pmcinfo_size = npmc * sizeof(struct pmc_info); 2818 MALLOC(pmcinfo, struct pmc_info *, pmcinfo_size, M_PMC, 2819 M_WAITOK); 2820 2821 p = pmcinfo; 2822 2823 for (n = 0; n < md->pmd_npmc; n++, p++) { 2824 2825 if ((error = md->pmd_describe(cpu, n, p, &pm)) != 0) 2826 break; 2827 2828 if (PMC_ROW_DISP_IS_STANDALONE(n)) 2829 p->pm_rowdisp = PMC_DISP_STANDALONE; 2830 else if (PMC_ROW_DISP_IS_THREAD(n)) 2831 p->pm_rowdisp = PMC_DISP_THREAD; 2832 else 2833 p->pm_rowdisp = PMC_DISP_FREE; 2834 2835 p->pm_ownerpid = -1; 2836 2837 if (pm == NULL) /* no PMC associated */ 2838 continue; 2839 2840 po = pm->pm_owner; 2841 2842 KASSERT(po->po_owner != NULL, 2843 ("[pmc,%d] pmc_owner had a null proc pointer", 2844 __LINE__)); 2845 2846 p->pm_ownerpid = po->po_owner->p_pid; 2847 p->pm_mode = PMC_TO_MODE(pm); 2848 p->pm_event = pm->pm_event; 2849 p->pm_flags = pm->pm_flags; 2850 2851 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 2852 p->pm_reloadcount = 2853 pm->pm_sc.pm_reloadcount; 2854 } 2855 2856 pmc_restore_cpu_binding(&pb); 2857 2858 /* now copy out the PMC info collected */ 2859 if (error == 0) 2860 error = copyout(pmcinfo, &gpi->pm_pmcs, pmcinfo_size); 2861 2862 FREE(pmcinfo, M_PMC); 2863 } 2864 break; 2865 2866 2867 /* 2868 * Set the administrative state of a PMC. I.e. whether 2869 * the PMC is to be used or not. 2870 */ 2871 2872 case PMC_OP_PMCADMIN: 2873 { 2874 int cpu, ri; 2875 enum pmc_state request; 2876 struct pmc_cpu *pc; 2877 struct pmc_hw *phw; 2878 struct pmc_op_pmcadmin pma; 2879 struct pmc_binding pb; 2880 2881 sx_assert(&pmc_sx, SX_XLOCKED); 2882 2883 KASSERT(td == curthread, 2884 ("[pmc,%d] td != curthread", __LINE__)); 2885 2886 error = priv_check(td, PRIV_PMC_MANAGE); 2887 if (error) 2888 break; 2889 2890 if ((error = copyin(arg, &pma, sizeof(pma))) != 0) 2891 break; 2892 2893 cpu = pma.pm_cpu; 2894 2895 if (cpu < 0 || cpu >= mp_ncpus) { 2896 error = EINVAL; 2897 break; 2898 } 2899 2900 if (pmc_cpu_is_disabled(cpu)) { 2901 error = ENXIO; 2902 break; 2903 } 2904 2905 request = pma.pm_state; 2906 2907 if (request != PMC_STATE_DISABLED && 2908 request != PMC_STATE_FREE) { 2909 error = EINVAL; 2910 break; 2911 } 2912 2913 ri = pma.pm_pmc; /* pmc id == row index */ 2914 if (ri < 0 || ri >= (int) md->pmd_npmc) { 2915 error = EINVAL; 2916 break; 2917 } 2918 2919 /* 2920 * We can't disable a PMC with a row-index allocated 2921 * for process virtual PMCs. 2922 */ 2923 2924 if (PMC_ROW_DISP_IS_THREAD(ri) && 2925 request == PMC_STATE_DISABLED) { 2926 error = EBUSY; 2927 break; 2928 } 2929 2930 /* 2931 * otherwise, this PMC on this CPU is either free or 2932 * in system-wide mode. 2933 */ 2934 2935 pmc_save_cpu_binding(&pb); 2936 pmc_select_cpu(cpu); 2937 2938 pc = pmc_pcpu[cpu]; 2939 phw = pc->pc_hwpmcs[ri]; 2940 2941 /* 2942 * XXX do we need some kind of 'forced' disable? 2943 */ 2944 2945 if (phw->phw_pmc == NULL) { 2946 if (request == PMC_STATE_DISABLED && 2947 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED)) { 2948 phw->phw_state &= ~PMC_PHW_FLAG_IS_ENABLED; 2949 PMC_MARK_ROW_STANDALONE(ri); 2950 } else if (request == PMC_STATE_FREE && 2951 (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0) { 2952 phw->phw_state |= PMC_PHW_FLAG_IS_ENABLED; 2953 PMC_UNMARK_ROW_STANDALONE(ri); 2954 } 2955 /* other cases are a no-op */ 2956 } else 2957 error = EBUSY; 2958 2959 pmc_restore_cpu_binding(&pb); 2960 } 2961 break; 2962 2963 2964 /* 2965 * Allocate a PMC. 2966 */ 2967 2968 case PMC_OP_PMCALLOCATE: 2969 { 2970 uint32_t caps; 2971 u_int cpu; 2972 int n; 2973 enum pmc_mode mode; 2974 struct pmc *pmc; 2975 struct pmc_hw *phw; 2976 struct pmc_op_pmcallocate pa; 2977 struct pmc_binding pb; 2978 2979 if ((error = copyin(arg, &pa, sizeof(pa))) != 0) 2980 break; 2981 2982 caps = pa.pm_caps; 2983 mode = pa.pm_mode; 2984 cpu = pa.pm_cpu; 2985 2986 if ((mode != PMC_MODE_SS && mode != PMC_MODE_SC && 2987 mode != PMC_MODE_TS && mode != PMC_MODE_TC) || 2988 (cpu != (u_int) PMC_CPU_ANY && cpu >= (u_int) mp_ncpus)) { 2989 error = EINVAL; 2990 break; 2991 } 2992 2993 /* 2994 * Virtual PMCs should only ask for a default CPU. 2995 * System mode PMCs need to specify a non-default CPU. 2996 */ 2997 2998 if ((PMC_IS_VIRTUAL_MODE(mode) && cpu != (u_int) PMC_CPU_ANY) || 2999 (PMC_IS_SYSTEM_MODE(mode) && cpu == (u_int) PMC_CPU_ANY)) { 3000 error = EINVAL; 3001 break; 3002 } 3003 3004 /* 3005 * Check that a disabled CPU is not being asked for. 3006 */ 3007 3008 if (PMC_IS_SYSTEM_MODE(mode) && pmc_cpu_is_disabled(cpu)) { 3009 error = ENXIO; 3010 break; 3011 } 3012 3013 /* 3014 * Refuse an allocation for a system-wide PMC if this 3015 * process has been jailed, or if this process lacks 3016 * super-user credentials and the sysctl tunable 3017 * 'security.bsd.unprivileged_syspmcs' is zero. 3018 */ 3019 3020 if (PMC_IS_SYSTEM_MODE(mode)) { 3021 if (jailed(curthread->td_ucred)) { 3022 error = EPERM; 3023 break; 3024 } 3025 if (!pmc_unprivileged_syspmcs) { 3026 error = priv_check(curthread, 3027 PRIV_PMC_SYSTEM); 3028 if (error) 3029 break; 3030 } 3031 } 3032 3033 if (error) 3034 break; 3035 3036 /* 3037 * Look for valid values for 'pm_flags' 3038 */ 3039 3040 if ((pa.pm_flags & ~(PMC_F_DESCENDANTS | PMC_F_LOG_PROCCSW | 3041 PMC_F_LOG_PROCEXIT | PMC_F_CALLCHAIN)) != 0) { 3042 error = EINVAL; 3043 break; 3044 } 3045 3046 /* process logging options are not allowed for system PMCs */ 3047 if (PMC_IS_SYSTEM_MODE(mode) && (pa.pm_flags & 3048 (PMC_F_LOG_PROCCSW | PMC_F_LOG_PROCEXIT))) { 3049 error = EINVAL; 3050 break; 3051 } 3052 3053 /* 3054 * All sampling mode PMCs need to be able to interrupt the 3055 * CPU. 3056 */ 3057 if (PMC_IS_SAMPLING_MODE(mode)) 3058 caps |= PMC_CAP_INTERRUPT; 3059 3060 /* A valid class specifier should have been passed in. */ 3061 for (n = 0; n < md->pmd_nclass; n++) 3062 if (md->pmd_classes[n].pm_class == pa.pm_class) 3063 break; 3064 if (n == md->pmd_nclass) { 3065 error = EINVAL; 3066 break; 3067 } 3068 3069 /* The requested PMC capabilities should be feasible. */ 3070 if ((md->pmd_classes[n].pm_caps & caps) != caps) { 3071 error = EOPNOTSUPP; 3072 break; 3073 } 3074 3075 PMCDBG(PMC,ALL,2, "event=%d caps=0x%x mode=%d cpu=%d", 3076 pa.pm_ev, caps, mode, cpu); 3077 3078 pmc = pmc_allocate_pmc_descriptor(); 3079 pmc->pm_id = PMC_ID_MAKE_ID(cpu,pa.pm_mode,pa.pm_class, 3080 PMC_ID_INVALID); 3081 pmc->pm_event = pa.pm_ev; 3082 pmc->pm_state = PMC_STATE_FREE; 3083 pmc->pm_caps = caps; 3084 pmc->pm_flags = pa.pm_flags; 3085 3086 /* switch thread to CPU 'cpu' */ 3087 pmc_save_cpu_binding(&pb); 3088 3089 #define PMC_IS_SHAREABLE_PMC(cpu, n) \ 3090 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_state & \ 3091 PMC_PHW_FLAG_IS_SHAREABLE) 3092 #define PMC_IS_UNALLOCATED(cpu, n) \ 3093 (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_pmc == NULL) 3094 3095 if (PMC_IS_SYSTEM_MODE(mode)) { 3096 pmc_select_cpu(cpu); 3097 for (n = 0; n < (int) md->pmd_npmc; n++) 3098 if (pmc_can_allocate_row(n, mode) == 0 && 3099 pmc_can_allocate_rowindex( 3100 curthread->td_proc, n, cpu) == 0 && 3101 (PMC_IS_UNALLOCATED(cpu, n) || 3102 PMC_IS_SHAREABLE_PMC(cpu, n)) && 3103 md->pmd_allocate_pmc(cpu, n, pmc, 3104 &pa) == 0) 3105 break; 3106 } else { 3107 /* Process virtual mode */ 3108 for (n = 0; n < (int) md->pmd_npmc; n++) { 3109 if (pmc_can_allocate_row(n, mode) == 0 && 3110 pmc_can_allocate_rowindex( 3111 curthread->td_proc, n, 3112 PMC_CPU_ANY) == 0 && 3113 md->pmd_allocate_pmc(curthread->td_oncpu, 3114 n, pmc, &pa) == 0) 3115 break; 3116 } 3117 } 3118 3119 #undef PMC_IS_UNALLOCATED 3120 #undef PMC_IS_SHAREABLE_PMC 3121 3122 pmc_restore_cpu_binding(&pb); 3123 3124 if (n == (int) md->pmd_npmc) { 3125 pmc_destroy_pmc_descriptor(pmc); 3126 FREE(pmc, M_PMC); 3127 pmc = NULL; 3128 error = EINVAL; 3129 break; 3130 } 3131 3132 /* Fill in the correct value in the ID field */ 3133 pmc->pm_id = PMC_ID_MAKE_ID(cpu,mode,pa.pm_class,n); 3134 3135 PMCDBG(PMC,ALL,2, "ev=%d class=%d mode=%d n=%d -> pmcid=%x", 3136 pmc->pm_event, pa.pm_class, mode, n, pmc->pm_id); 3137 3138 /* Process mode PMCs with logging enabled need log files */ 3139 if (pmc->pm_flags & (PMC_F_LOG_PROCEXIT | PMC_F_LOG_PROCCSW)) 3140 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3141 3142 /* All system mode sampling PMCs require a log file */ 3143 if (PMC_IS_SAMPLING_MODE(mode) && PMC_IS_SYSTEM_MODE(mode)) 3144 pmc->pm_flags |= PMC_F_NEEDS_LOGFILE; 3145 3146 /* 3147 * Configure global pmc's immediately 3148 */ 3149 3150 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pmc))) { 3151 3152 pmc_save_cpu_binding(&pb); 3153 pmc_select_cpu(cpu); 3154 3155 phw = pmc_pcpu[cpu]->pc_hwpmcs[n]; 3156 3157 if ((phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0 || 3158 (error = md->pmd_config_pmc(cpu, n, pmc)) != 0) { 3159 (void) md->pmd_release_pmc(cpu, n, pmc); 3160 pmc_destroy_pmc_descriptor(pmc); 3161 FREE(pmc, M_PMC); 3162 pmc = NULL; 3163 pmc_restore_cpu_binding(&pb); 3164 error = EPERM; 3165 break; 3166 } 3167 3168 pmc_restore_cpu_binding(&pb); 3169 } 3170 3171 pmc->pm_state = PMC_STATE_ALLOCATED; 3172 3173 /* 3174 * mark row disposition 3175 */ 3176 3177 if (PMC_IS_SYSTEM_MODE(mode)) 3178 PMC_MARK_ROW_STANDALONE(n); 3179 else 3180 PMC_MARK_ROW_THREAD(n); 3181 3182 /* 3183 * Register this PMC with the current thread as its owner. 3184 */ 3185 3186 if ((error = 3187 pmc_register_owner(curthread->td_proc, pmc)) != 0) { 3188 pmc_release_pmc_descriptor(pmc); 3189 FREE(pmc, M_PMC); 3190 pmc = NULL; 3191 break; 3192 } 3193 3194 /* 3195 * Return the allocated index. 3196 */ 3197 3198 pa.pm_pmcid = pmc->pm_id; 3199 3200 error = copyout(&pa, arg, sizeof(pa)); 3201 } 3202 break; 3203 3204 3205 /* 3206 * Attach a PMC to a process. 3207 */ 3208 3209 case PMC_OP_PMCATTACH: 3210 { 3211 struct pmc *pm; 3212 struct proc *p; 3213 struct pmc_op_pmcattach a; 3214 3215 sx_assert(&pmc_sx, SX_XLOCKED); 3216 3217 if ((error = copyin(arg, &a, sizeof(a))) != 0) 3218 break; 3219 3220 if (a.pm_pid < 0) { 3221 error = EINVAL; 3222 break; 3223 } else if (a.pm_pid == 0) 3224 a.pm_pid = td->td_proc->p_pid; 3225 3226 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 3227 break; 3228 3229 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) { 3230 error = EINVAL; 3231 break; 3232 } 3233 3234 /* PMCs may be (re)attached only when allocated or stopped */ 3235 if (pm->pm_state == PMC_STATE_RUNNING) { 3236 error = EBUSY; 3237 break; 3238 } else if (pm->pm_state != PMC_STATE_ALLOCATED && 3239 pm->pm_state != PMC_STATE_STOPPED) { 3240 error = EINVAL; 3241 break; 3242 } 3243 3244 /* lookup pid */ 3245 if ((p = pfind(a.pm_pid)) == NULL) { 3246 error = ESRCH; 3247 break; 3248 } 3249 3250 /* 3251 * Ignore processes that are working on exiting. 3252 */ 3253 if (p->p_flag & P_WEXIT) { 3254 error = ESRCH; 3255 PROC_UNLOCK(p); /* pfind() returns a locked process */ 3256 break; 3257 } 3258 3259 /* 3260 * we are allowed to attach a PMC to a process if 3261 * we can debug it. 3262 */ 3263 error = p_candebug(curthread, p); 3264 3265 PROC_UNLOCK(p); 3266 3267 if (error == 0) 3268 error = pmc_attach_process(p, pm); 3269 } 3270 break; 3271 3272 3273 /* 3274 * Detach an attached PMC from a process. 3275 */ 3276 3277 case PMC_OP_PMCDETACH: 3278 { 3279 struct pmc *pm; 3280 struct proc *p; 3281 struct pmc_op_pmcattach a; 3282 3283 if ((error = copyin(arg, &a, sizeof(a))) != 0) 3284 break; 3285 3286 if (a.pm_pid < 0) { 3287 error = EINVAL; 3288 break; 3289 } else if (a.pm_pid == 0) 3290 a.pm_pid = td->td_proc->p_pid; 3291 3292 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) 3293 break; 3294 3295 if ((p = pfind(a.pm_pid)) == NULL) { 3296 error = ESRCH; 3297 break; 3298 } 3299 3300 /* 3301 * Treat processes that are in the process of exiting 3302 * as if they were not present. 3303 */ 3304 3305 if (p->p_flag & P_WEXIT) 3306 error = ESRCH; 3307 3308 PROC_UNLOCK(p); /* pfind() returns a locked process */ 3309 3310 if (error == 0) 3311 error = pmc_detach_process(p, pm); 3312 } 3313 break; 3314 3315 3316 /* 3317 * Retrieve the MSR number associated with the counter 3318 * 'pmc_id'. This allows processes to directly use RDPMC 3319 * instructions to read their PMCs, without the overhead of a 3320 * system call. 3321 */ 3322 3323 case PMC_OP_PMCGETMSR: 3324 { 3325 int ri; 3326 struct pmc *pm; 3327 struct pmc_target *pt; 3328 struct pmc_op_getmsr gm; 3329 3330 PMC_DOWNGRADE_SX(); 3331 3332 /* CPU has no 'GETMSR' support */ 3333 if (md->pmd_get_msr == NULL) { 3334 error = ENOSYS; 3335 break; 3336 } 3337 3338 if ((error = copyin(arg, &gm, sizeof(gm))) != 0) 3339 break; 3340 3341 if ((error = pmc_find_pmc(gm.pm_pmcid, &pm)) != 0) 3342 break; 3343 3344 /* 3345 * The allocated PMC has to be a process virtual PMC, 3346 * i.e., of type MODE_T[CS]. Global PMCs can only be 3347 * read using the PMCREAD operation since they may be 3348 * allocated on a different CPU than the one we could 3349 * be running on at the time of the RDPMC instruction. 3350 * 3351 * The GETMSR operation is not allowed for PMCs that 3352 * are inherited across processes. 3353 */ 3354 3355 if (!PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)) || 3356 (pm->pm_flags & PMC_F_DESCENDANTS)) { 3357 error = EINVAL; 3358 break; 3359 } 3360 3361 /* 3362 * It only makes sense to use a RDPMC (or its 3363 * equivalent instruction on non-x86 architectures) on 3364 * a process that has allocated and attached a PMC to 3365 * itself. Conversely the PMC is only allowed to have 3366 * one process attached to it -- its owner. 3367 */ 3368 3369 if ((pt = LIST_FIRST(&pm->pm_targets)) == NULL || 3370 LIST_NEXT(pt, pt_next) != NULL || 3371 pt->pt_process->pp_proc != pm->pm_owner->po_owner) { 3372 error = EINVAL; 3373 break; 3374 } 3375 3376 ri = PMC_TO_ROWINDEX(pm); 3377 3378 if ((error = (*md->pmd_get_msr)(ri, &gm.pm_msr)) < 0) 3379 break; 3380 3381 if ((error = copyout(&gm, arg, sizeof(gm))) < 0) 3382 break; 3383 3384 /* 3385 * Mark our process as using MSRs. Update machine 3386 * state using a forced context switch. 3387 */ 3388 3389 pt->pt_process->pp_flags |= PMC_PP_ENABLE_MSR_ACCESS; 3390 pmc_force_context_switch(); 3391 3392 } 3393 break; 3394 3395 /* 3396 * Release an allocated PMC 3397 */ 3398 3399 case PMC_OP_PMCRELEASE: 3400 { 3401 pmc_id_t pmcid; 3402 struct pmc *pm; 3403 struct pmc_owner *po; 3404 struct pmc_op_simple sp; 3405 3406 /* 3407 * Find PMC pointer for the named PMC. 3408 * 3409 * Use pmc_release_pmc_descriptor() to switch off the 3410 * PMC, remove all its target threads, and remove the 3411 * PMC from its owner's list. 3412 * 3413 * Remove the owner record if this is the last PMC 3414 * owned. 3415 * 3416 * Free up space. 3417 */ 3418 3419 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3420 break; 3421 3422 pmcid = sp.pm_pmcid; 3423 3424 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3425 break; 3426 3427 po = pm->pm_owner; 3428 pmc_release_pmc_descriptor(pm); 3429 pmc_maybe_remove_owner(po); 3430 3431 FREE(pm, M_PMC); 3432 } 3433 break; 3434 3435 3436 /* 3437 * Read and/or write a PMC. 3438 */ 3439 3440 case PMC_OP_PMCRW: 3441 { 3442 uint32_t cpu, ri; 3443 struct pmc *pm; 3444 struct pmc_op_pmcrw *pprw; 3445 struct pmc_op_pmcrw prw; 3446 struct pmc_binding pb; 3447 pmc_value_t oldvalue; 3448 3449 PMC_DOWNGRADE_SX(); 3450 3451 if ((error = copyin(arg, &prw, sizeof(prw))) != 0) 3452 break; 3453 3454 ri = 0; 3455 PMCDBG(PMC,OPS,1, "rw id=%d flags=0x%x", prw.pm_pmcid, 3456 prw.pm_flags); 3457 3458 /* must have at least one flag set */ 3459 if ((prw.pm_flags & (PMC_F_OLDVALUE|PMC_F_NEWVALUE)) == 0) { 3460 error = EINVAL; 3461 break; 3462 } 3463 3464 /* locate pmc descriptor */ 3465 if ((error = pmc_find_pmc(prw.pm_pmcid, &pm)) != 0) 3466 break; 3467 3468 /* Can't read a PMC that hasn't been started. */ 3469 if (pm->pm_state != PMC_STATE_ALLOCATED && 3470 pm->pm_state != PMC_STATE_STOPPED && 3471 pm->pm_state != PMC_STATE_RUNNING) { 3472 error = EINVAL; 3473 break; 3474 } 3475 3476 /* writing a new value is allowed only for 'STOPPED' pmcs */ 3477 if (pm->pm_state == PMC_STATE_RUNNING && 3478 (prw.pm_flags & PMC_F_NEWVALUE)) { 3479 error = EBUSY; 3480 break; 3481 } 3482 3483 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) { 3484 3485 /* 3486 * If this PMC is attached to its owner (i.e., 3487 * the process requesting this operation) and 3488 * is running, then attempt to get an 3489 * upto-date reading from hardware for a READ. 3490 * Writes are only allowed when the PMC is 3491 * stopped, so only update the saved value 3492 * field. 3493 * 3494 * If the PMC is not running, or is not 3495 * attached to its owner, read/write to the 3496 * savedvalue field. 3497 */ 3498 3499 ri = PMC_TO_ROWINDEX(pm); 3500 3501 mtx_pool_lock_spin(pmc_mtxpool, pm); 3502 cpu = curthread->td_oncpu; 3503 3504 if (prw.pm_flags & PMC_F_OLDVALUE) { 3505 if ((pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) && 3506 (pm->pm_state == PMC_STATE_RUNNING)) 3507 error = (*md->pmd_read_pmc)(cpu, ri, 3508 &oldvalue); 3509 else 3510 oldvalue = pm->pm_gv.pm_savedvalue; 3511 } 3512 if (prw.pm_flags & PMC_F_NEWVALUE) 3513 pm->pm_gv.pm_savedvalue = prw.pm_value; 3514 3515 mtx_pool_unlock_spin(pmc_mtxpool, pm); 3516 3517 } else { /* System mode PMCs */ 3518 cpu = PMC_TO_CPU(pm); 3519 ri = PMC_TO_ROWINDEX(pm); 3520 3521 if (pmc_cpu_is_disabled(cpu)) { 3522 error = ENXIO; 3523 break; 3524 } 3525 3526 /* move this thread to CPU 'cpu' */ 3527 pmc_save_cpu_binding(&pb); 3528 pmc_select_cpu(cpu); 3529 3530 critical_enter(); 3531 /* save old value */ 3532 if (prw.pm_flags & PMC_F_OLDVALUE) 3533 if ((error = (*md->pmd_read_pmc)(cpu, ri, 3534 &oldvalue))) 3535 goto error; 3536 /* write out new value */ 3537 if (prw.pm_flags & PMC_F_NEWVALUE) 3538 error = (*md->pmd_write_pmc)(cpu, ri, 3539 prw.pm_value); 3540 error: 3541 critical_exit(); 3542 pmc_restore_cpu_binding(&pb); 3543 if (error) 3544 break; 3545 } 3546 3547 pprw = (struct pmc_op_pmcrw *) arg; 3548 3549 #ifdef DEBUG 3550 if (prw.pm_flags & PMC_F_NEWVALUE) 3551 PMCDBG(PMC,OPS,2, "rw id=%d new %jx -> old %jx", 3552 ri, prw.pm_value, oldvalue); 3553 else if (prw.pm_flags & PMC_F_OLDVALUE) 3554 PMCDBG(PMC,OPS,2, "rw id=%d -> old %jx", ri, oldvalue); 3555 #endif 3556 3557 /* return old value if requested */ 3558 if (prw.pm_flags & PMC_F_OLDVALUE) 3559 if ((error = copyout(&oldvalue, &pprw->pm_value, 3560 sizeof(prw.pm_value)))) 3561 break; 3562 3563 } 3564 break; 3565 3566 3567 /* 3568 * Set the sampling rate for a sampling mode PMC and the 3569 * initial count for a counting mode PMC. 3570 */ 3571 3572 case PMC_OP_PMCSETCOUNT: 3573 { 3574 struct pmc *pm; 3575 struct pmc_op_pmcsetcount sc; 3576 3577 PMC_DOWNGRADE_SX(); 3578 3579 if ((error = copyin(arg, &sc, sizeof(sc))) != 0) 3580 break; 3581 3582 if ((error = pmc_find_pmc(sc.pm_pmcid, &pm)) != 0) 3583 break; 3584 3585 if (pm->pm_state == PMC_STATE_RUNNING) { 3586 error = EBUSY; 3587 break; 3588 } 3589 3590 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) 3591 pm->pm_sc.pm_reloadcount = sc.pm_count; 3592 else 3593 pm->pm_sc.pm_initial = sc.pm_count; 3594 } 3595 break; 3596 3597 3598 /* 3599 * Start a PMC. 3600 */ 3601 3602 case PMC_OP_PMCSTART: 3603 { 3604 pmc_id_t pmcid; 3605 struct pmc *pm; 3606 struct pmc_op_simple sp; 3607 3608 sx_assert(&pmc_sx, SX_XLOCKED); 3609 3610 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3611 break; 3612 3613 pmcid = sp.pm_pmcid; 3614 3615 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3616 break; 3617 3618 KASSERT(pmcid == pm->pm_id, 3619 ("[pmc,%d] pmcid %x != id %x", __LINE__, 3620 pm->pm_id, pmcid)); 3621 3622 if (pm->pm_state == PMC_STATE_RUNNING) /* already running */ 3623 break; 3624 else if (pm->pm_state != PMC_STATE_STOPPED && 3625 pm->pm_state != PMC_STATE_ALLOCATED) { 3626 error = EINVAL; 3627 break; 3628 } 3629 3630 error = pmc_start(pm); 3631 } 3632 break; 3633 3634 3635 /* 3636 * Stop a PMC. 3637 */ 3638 3639 case PMC_OP_PMCSTOP: 3640 { 3641 pmc_id_t pmcid; 3642 struct pmc *pm; 3643 struct pmc_op_simple sp; 3644 3645 PMC_DOWNGRADE_SX(); 3646 3647 if ((error = copyin(arg, &sp, sizeof(sp))) != 0) 3648 break; 3649 3650 pmcid = sp.pm_pmcid; 3651 3652 /* 3653 * Mark the PMC as inactive and invoke the MD stop 3654 * routines if needed. 3655 */ 3656 3657 if ((error = pmc_find_pmc(pmcid, &pm)) != 0) 3658 break; 3659 3660 KASSERT(pmcid == pm->pm_id, 3661 ("[pmc,%d] pmc id %x != pmcid %x", __LINE__, 3662 pm->pm_id, pmcid)); 3663 3664 if (pm->pm_state == PMC_STATE_STOPPED) /* already stopped */ 3665 break; 3666 else if (pm->pm_state != PMC_STATE_RUNNING) { 3667 error = EINVAL; 3668 break; 3669 } 3670 3671 error = pmc_stop(pm); 3672 } 3673 break; 3674 3675 3676 /* 3677 * Write a user supplied value to the log file. 3678 */ 3679 3680 case PMC_OP_WRITELOG: 3681 { 3682 struct pmc_op_writelog wl; 3683 struct pmc_owner *po; 3684 3685 PMC_DOWNGRADE_SX(); 3686 3687 if ((error = copyin(arg, &wl, sizeof(wl))) != 0) 3688 break; 3689 3690 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) { 3691 error = EINVAL; 3692 break; 3693 } 3694 3695 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) { 3696 error = EINVAL; 3697 break; 3698 } 3699 3700 error = pmclog_process_userlog(po, &wl); 3701 } 3702 break; 3703 3704 3705 default: 3706 error = EINVAL; 3707 break; 3708 } 3709 3710 if (is_sx_downgraded) 3711 sx_sunlock(&pmc_sx); 3712 else 3713 sx_xunlock(&pmc_sx); 3714 3715 if (error) 3716 atomic_add_int(&pmc_stats.pm_syscall_errors, 1); 3717 3718 PICKUP_GIANT(); 3719 3720 return error; 3721 } 3722 3723 /* 3724 * Helper functions 3725 */ 3726 3727 3728 /* 3729 * Mark the thread as needing callchain capture and post an AST. The 3730 * actual callchain capture will be done in a context where it is safe 3731 * to take page faults. 3732 */ 3733 3734 static void 3735 pmc_post_callchain_ast(void) 3736 { 3737 struct thread *td; 3738 3739 td = curthread; 3740 3741 /* 3742 * Mark this thread as needing processing in ast(). 3743 * td->td_pflags will be safe to touch as the process was in 3744 * user space when it was interrupted. 3745 */ 3746 td->td_pflags |= TDP_CALLCHAIN; 3747 3748 /* 3749 * Again, since we've entered this function directly from 3750 * userland, `td' is guaranteed to be not locked by this CPU, 3751 * so its safe to try acquire the thread lock even though we 3752 * are executing in an NMI context. We need to acquire this 3753 * lock before touching `td_flags' because other CPUs may be 3754 * in the process of touching this field. 3755 */ 3756 thread_lock(td); 3757 td->td_flags |= TDF_ASTPENDING; 3758 thread_unlock(td); 3759 3760 return; 3761 } 3762 3763 /* 3764 * Interrupt processing. 3765 * 3766 * Find a free slot in the per-cpu array of samples and capture the 3767 * current callchain there. If a sample was successfully added, a bit 3768 * is set in mask 'pmc_cpumask' denoting that the DO_SAMPLES hook 3769 * needs to be invoked from the clock handler. 3770 * 3771 * This function is meant to be called from an NMI handler. It cannot 3772 * use any of the locking primitives supplied by the OS. 3773 */ 3774 3775 int 3776 pmc_process_interrupt(int cpu, struct pmc *pm, struct trapframe *tf, 3777 int inuserspace) 3778 { 3779 int error, callchaindepth; 3780 struct thread *td; 3781 struct pmc_sample *ps; 3782 struct pmc_samplebuffer *psb; 3783 3784 error = 0; 3785 3786 /* 3787 * Allocate space for a sample buffer. 3788 */ 3789 psb = pmc_pcpu[cpu]->pc_sb; 3790 3791 ps = psb->ps_write; 3792 if (ps->ps_nsamples) { /* in use, reader hasn't caught up */ 3793 pm->pm_stalled = 1; 3794 atomic_add_int(&pmc_stats.pm_intr_bufferfull, 1); 3795 PMCDBG(SAM,INT,1,"(spc) cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", 3796 cpu, pm, (void *) tf, inuserspace, 3797 (int) (psb->ps_write - psb->ps_samples), 3798 (int) (psb->ps_read - psb->ps_samples)); 3799 error = ENOMEM; 3800 goto done; 3801 } 3802 3803 3804 /* Fill in entry. */ 3805 PMCDBG(SAM,INT,1,"cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", cpu, pm, 3806 (void *) tf, inuserspace, 3807 (int) (psb->ps_write - psb->ps_samples), 3808 (int) (psb->ps_read - psb->ps_samples)); 3809 3810 atomic_add_rel_32(&pm->pm_runcount, 1); /* hold onto PMC */ 3811 ps->ps_pmc = pm; 3812 if ((td = curthread) && td->td_proc) 3813 ps->ps_pid = td->td_proc->p_pid; 3814 else 3815 ps->ps_pid = -1; 3816 ps->ps_cpu = cpu; 3817 ps->ps_flags = inuserspace ? PMC_CC_F_USERSPACE : 0; 3818 3819 callchaindepth = (pm->pm_flags & PMC_F_CALLCHAIN) ? 3820 pmc_callchaindepth : 1; 3821 3822 if (callchaindepth == 1) 3823 ps->ps_pc[0] = PMC_TRAPFRAME_TO_PC(tf); 3824 else { 3825 /* 3826 * Kernel stack traversals can be done immediately, 3827 * while we defer to an AST for user space traversals. 3828 */ 3829 if (!inuserspace) 3830 callchaindepth = 3831 pmc_save_kernel_callchain(ps->ps_pc, 3832 callchaindepth, tf); 3833 else { 3834 pmc_post_callchain_ast(); 3835 callchaindepth = PMC_SAMPLE_INUSE; 3836 } 3837 } 3838 3839 ps->ps_nsamples = callchaindepth; /* mark entry as in use */ 3840 3841 /* increment write pointer, modulo ring buffer size */ 3842 ps++; 3843 if (ps == psb->ps_fence) 3844 psb->ps_write = psb->ps_samples; 3845 else 3846 psb->ps_write = ps; 3847 3848 done: 3849 /* mark CPU as needing processing */ 3850 atomic_set_rel_int(&pmc_cpumask, (1 << cpu)); 3851 3852 return (error); 3853 } 3854 3855 /* 3856 * Capture a user call chain. This function will be called from ast() 3857 * before control returns to userland and before the process gets 3858 * rescheduled. 3859 */ 3860 3861 static void 3862 pmc_capture_user_callchain(int cpu, struct trapframe *tf) 3863 { 3864 int i; 3865 struct pmc *pm; 3866 struct pmc_sample *ps; 3867 struct pmc_samplebuffer *psb; 3868 3869 psb = pmc_pcpu[cpu]->pc_sb; 3870 3871 /* 3872 * Iterate through all deferred callchain requests. 3873 */ 3874 3875 for (i = 0; i < pmc_nsamples; i++) { 3876 3877 ps = &psb->ps_samples[i]; 3878 if (ps->ps_nsamples != PMC_SAMPLE_INUSE) 3879 continue; 3880 3881 pm = ps->ps_pmc; 3882 3883 KASSERT(pm->pm_flags & PMC_F_CALLCHAIN, 3884 ("[pmc,%d] Retrieving callchain for PMC that doesn't " 3885 "want it", __LINE__)); 3886 3887 /* 3888 * Retrieve the callchain and mark the sample buffer 3889 * as 'processable' by the timer tick sweep code. 3890 */ 3891 ps->ps_nsamples = pmc_save_user_callchain(ps->ps_pc, 3892 pmc_callchaindepth, tf); 3893 } 3894 3895 return; 3896 } 3897 3898 3899 /* 3900 * Process saved PC samples. 3901 */ 3902 3903 static void 3904 pmc_process_samples(int cpu) 3905 { 3906 int n, ri; 3907 struct pmc *pm; 3908 struct thread *td; 3909 struct pmc_owner *po; 3910 struct pmc_sample *ps; 3911 struct pmc_samplebuffer *psb; 3912 3913 KASSERT(PCPU_GET(cpuid) == cpu, 3914 ("[pmc,%d] not on the correct CPU pcpu=%d cpu=%d", __LINE__, 3915 PCPU_GET(cpuid), cpu)); 3916 3917 psb = pmc_pcpu[cpu]->pc_sb; 3918 3919 for (n = 0; n < pmc_nsamples; n++) { /* bound on #iterations */ 3920 3921 ps = psb->ps_read; 3922 if (ps->ps_nsamples == PMC_SAMPLE_FREE) 3923 break; 3924 if (ps->ps_nsamples == PMC_SAMPLE_INUSE) { 3925 /* Need a rescan at a later time. */ 3926 atomic_set_rel_int(&pmc_cpumask, (1 << cpu)); 3927 break; 3928 } 3929 3930 pm = ps->ps_pmc; 3931 po = pm->pm_owner; 3932 3933 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)), 3934 ("[pmc,%d] pmc=%p non-sampling mode=%d", __LINE__, 3935 pm, PMC_TO_MODE(pm))); 3936 3937 /* Ignore PMCs that have been switched off */ 3938 if (pm->pm_state != PMC_STATE_RUNNING) 3939 goto entrydone; 3940 3941 PMCDBG(SAM,OPS,1,"cpu=%d pm=%p n=%d fl=%x wr=%d rd=%d", cpu, 3942 pm, ps->ps_nsamples, ps->ps_flags, 3943 (int) (psb->ps_write - psb->ps_samples), 3944 (int) (psb->ps_read - psb->ps_samples)); 3945 3946 /* 3947 * If this is a process-mode PMC that is attached to 3948 * its owner, and if the PC is in user mode, update 3949 * profiling statistics like timer-based profiling 3950 * would have done. 3951 */ 3952 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) { 3953 if (ps->ps_flags & PMC_CC_F_USERSPACE) { 3954 td = FIRST_THREAD_IN_PROC(po->po_owner); 3955 addupc_intr(td, ps->ps_pc[0], 1); 3956 } 3957 goto entrydone; 3958 } 3959 3960 /* 3961 * Otherwise, this is either a sampling mode PMC that 3962 * is attached to a different process than its owner, 3963 * or a system-wide sampling PMC. Dispatch a log 3964 * entry to the PMC's owner process. 3965 */ 3966 3967 pmclog_process_callchain(pm, ps); 3968 3969 entrydone: 3970 ps->ps_nsamples = 0; /* mark entry as free */ 3971 atomic_subtract_rel_32(&pm->pm_runcount, 1); 3972 3973 /* increment read pointer, modulo sample size */ 3974 if (++ps == psb->ps_fence) 3975 psb->ps_read = psb->ps_samples; 3976 else 3977 psb->ps_read = ps; 3978 } 3979 3980 atomic_add_int(&pmc_stats.pm_log_sweeps, 1); 3981 3982 /* Do not re-enable stalled PMCs if we failed to process any samples */ 3983 if (n == 0) 3984 return; 3985 3986 /* 3987 * Restart any stalled sampling PMCs on this CPU. 3988 * 3989 * If the NMI handler sets the pm_stalled field of a PMC after 3990 * the check below, we'll end up processing the stalled PMC at 3991 * the next hardclock tick. 3992 */ 3993 for (n = 0; n < md->pmd_npmc; n++) { 3994 (void) (*md->pmd_get_config)(cpu,n,&pm); 3995 if (pm == NULL || /* !cfg'ed */ 3996 pm->pm_state != PMC_STATE_RUNNING || /* !active */ 3997 !PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) || /* !sampling */ 3998 pm->pm_stalled == 0) /* !stalled */ 3999 continue; 4000 4001 pm->pm_stalled = 0; 4002 ri = PMC_TO_ROWINDEX(pm); 4003 (*md->pmd_start_pmc)(cpu, ri); 4004 } 4005 } 4006 4007 /* 4008 * Event handlers. 4009 */ 4010 4011 /* 4012 * Handle a process exit. 4013 * 4014 * Remove this process from all hash tables. If this process 4015 * owned any PMCs, turn off those PMCs and deallocate them, 4016 * removing any associations with target processes. 4017 * 4018 * This function will be called by the last 'thread' of a 4019 * process. 4020 * 4021 * XXX This eventhandler gets called early in the exit process. 4022 * Consider using a 'hook' invocation from thread_exit() or equivalent 4023 * spot. Another negative is that kse_exit doesn't seem to call 4024 * exit1() [??]. 4025 * 4026 */ 4027 4028 static void 4029 pmc_process_exit(void *arg __unused, struct proc *p) 4030 { 4031 int is_using_hwpmcs; 4032 int cpu; 4033 unsigned int ri; 4034 struct pmc *pm; 4035 struct pmc_process *pp; 4036 struct pmc_owner *po; 4037 pmc_value_t newvalue, tmp; 4038 4039 PROC_LOCK(p); 4040 is_using_hwpmcs = p->p_flag & P_HWPMC; 4041 PROC_UNLOCK(p); 4042 4043 /* 4044 * Log a sysexit event to all SS PMC owners. 4045 */ 4046 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4047 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4048 pmclog_process_sysexit(po, p->p_pid); 4049 4050 if (!is_using_hwpmcs) 4051 return; 4052 4053 PMC_GET_SX_XLOCK(); 4054 PMCDBG(PRC,EXT,1,"process-exit proc=%p (%d, %s)", p, p->p_pid, 4055 p->p_comm); 4056 4057 /* 4058 * Since this code is invoked by the last thread in an exiting 4059 * process, we would have context switched IN at some prior 4060 * point. However, with PREEMPTION, kernel mode context 4061 * switches may happen any time, so we want to disable a 4062 * context switch OUT till we get any PMCs targetting this 4063 * process off the hardware. 4064 * 4065 * We also need to atomically remove this process' 4066 * entry from our target process hash table, using 4067 * PMC_FLAG_REMOVE. 4068 */ 4069 PMCDBG(PRC,EXT,1, "process-exit proc=%p (%d, %s)", p, p->p_pid, 4070 p->p_comm); 4071 4072 critical_enter(); /* no preemption */ 4073 4074 cpu = curthread->td_oncpu; 4075 4076 if ((pp = pmc_find_process_descriptor(p, 4077 PMC_FLAG_REMOVE)) != NULL) { 4078 4079 PMCDBG(PRC,EXT,2, 4080 "process-exit proc=%p pmc-process=%p", p, pp); 4081 4082 /* 4083 * The exiting process could the target of 4084 * some PMCs which will be running on 4085 * currently executing CPU. 4086 * 4087 * We need to turn these PMCs off like we 4088 * would do at context switch OUT time. 4089 */ 4090 for (ri = 0; ri < md->pmd_npmc; ri++) { 4091 4092 /* 4093 * Pick up the pmc pointer from hardware 4094 * state similar to the CSW_OUT code. 4095 */ 4096 pm = NULL; 4097 (void) (*md->pmd_get_config)(cpu, ri, &pm); 4098 4099 PMCDBG(PRC,EXT,2, "ri=%d pm=%p", ri, pm); 4100 4101 if (pm == NULL || 4102 !PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) 4103 continue; 4104 4105 PMCDBG(PRC,EXT,2, "ppmcs[%d]=%p pm=%p " 4106 "state=%d", ri, pp->pp_pmcs[ri].pp_pmc, 4107 pm, pm->pm_state); 4108 4109 KASSERT(PMC_TO_ROWINDEX(pm) == ri, 4110 ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", 4111 __LINE__, PMC_TO_ROWINDEX(pm), ri)); 4112 4113 KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, 4114 ("[pmc,%d] pm %p != pp_pmcs[%d] %p", 4115 __LINE__, pm, ri, pp->pp_pmcs[ri].pp_pmc)); 4116 4117 (void) md->pmd_stop_pmc(cpu, ri); 4118 4119 KASSERT(pm->pm_runcount > 0, 4120 ("[pmc,%d] bad runcount ri %d rc %d", 4121 __LINE__, ri, pm->pm_runcount)); 4122 4123 /* Stop hardware only if it is actually running */ 4124 if (pm->pm_state == PMC_STATE_RUNNING && 4125 pm->pm_stalled == 0) { 4126 md->pmd_read_pmc(cpu, ri, &newvalue); 4127 tmp = newvalue - 4128 PMC_PCPU_SAVED(cpu,ri); 4129 4130 mtx_pool_lock_spin(pmc_mtxpool, pm); 4131 pm->pm_gv.pm_savedvalue += tmp; 4132 pp->pp_pmcs[ri].pp_pmcval += tmp; 4133 mtx_pool_unlock_spin(pmc_mtxpool, pm); 4134 } 4135 4136 atomic_subtract_rel_32(&pm->pm_runcount,1); 4137 4138 KASSERT((int) pm->pm_runcount >= 0, 4139 ("[pmc,%d] runcount is %d", __LINE__, ri)); 4140 4141 (void) md->pmd_config_pmc(cpu, ri, NULL); 4142 } 4143 4144 /* 4145 * Inform the MD layer of this pseudo "context switch 4146 * out" 4147 */ 4148 (void) md->pmd_switch_out(pmc_pcpu[cpu], pp); 4149 4150 critical_exit(); /* ok to be pre-empted now */ 4151 4152 /* 4153 * Unlink this process from the PMCs that are 4154 * targetting it. This will send a signal to 4155 * all PMC owner's whose PMCs are orphaned. 4156 * 4157 * Log PMC value at exit time if requested. 4158 */ 4159 for (ri = 0; ri < md->pmd_npmc; ri++) 4160 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { 4161 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE && 4162 PMC_IS_COUNTING_MODE(PMC_TO_MODE(pm))) 4163 pmclog_process_procexit(pm, pp); 4164 pmc_unlink_target_process(pm, pp); 4165 } 4166 FREE(pp, M_PMC); 4167 4168 } else 4169 critical_exit(); /* pp == NULL */ 4170 4171 4172 /* 4173 * If the process owned PMCs, free them up and free up 4174 * memory. 4175 */ 4176 if ((po = pmc_find_owner_descriptor(p)) != NULL) { 4177 pmc_remove_owner(po); 4178 pmc_destroy_owner_descriptor(po); 4179 } 4180 4181 sx_xunlock(&pmc_sx); 4182 } 4183 4184 /* 4185 * Handle a process fork. 4186 * 4187 * If the parent process 'p1' is under HWPMC monitoring, then copy 4188 * over any attached PMCs that have 'do_descendants' semantics. 4189 */ 4190 4191 static void 4192 pmc_process_fork(void *arg __unused, struct proc *p1, struct proc *newproc, 4193 int flags) 4194 { 4195 int is_using_hwpmcs; 4196 unsigned int ri; 4197 uint32_t do_descendants; 4198 struct pmc *pm; 4199 struct pmc_owner *po; 4200 struct pmc_process *ppnew, *ppold; 4201 4202 (void) flags; /* unused parameter */ 4203 4204 PROC_LOCK(p1); 4205 is_using_hwpmcs = p1->p_flag & P_HWPMC; 4206 PROC_UNLOCK(p1); 4207 4208 /* 4209 * If there are system-wide sampling PMCs active, we need to 4210 * log all fork events to their owner's logs. 4211 */ 4212 4213 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) 4214 if (po->po_flags & PMC_PO_OWNS_LOGFILE) 4215 pmclog_process_procfork(po, p1->p_pid, newproc->p_pid); 4216 4217 if (!is_using_hwpmcs) 4218 return; 4219 4220 PMC_GET_SX_XLOCK(); 4221 PMCDBG(PMC,FRK,1, "process-fork proc=%p (%d, %s) -> %p", p1, 4222 p1->p_pid, p1->p_comm, newproc); 4223 4224 /* 4225 * If the parent process (curthread->td_proc) is a 4226 * target of any PMCs, look for PMCs that are to be 4227 * inherited, and link these into the new process 4228 * descriptor. 4229 */ 4230 if ((ppold = pmc_find_process_descriptor(curthread->td_proc, 4231 PMC_FLAG_NONE)) == NULL) 4232 goto done; /* nothing to do */ 4233 4234 do_descendants = 0; 4235 for (ri = 0; ri < md->pmd_npmc; ri++) 4236 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL) 4237 do_descendants |= pm->pm_flags & PMC_F_DESCENDANTS; 4238 if (do_descendants == 0) /* nothing to do */ 4239 goto done; 4240 4241 /* allocate a descriptor for the new process */ 4242 if ((ppnew = pmc_find_process_descriptor(newproc, 4243 PMC_FLAG_ALLOCATE)) == NULL) 4244 goto done; 4245 4246 /* 4247 * Run through all PMCs that were targeting the old process 4248 * and which specified F_DESCENDANTS and attach them to the 4249 * new process. 4250 * 4251 * Log the fork event to all owners of PMCs attached to this 4252 * process, if not already logged. 4253 */ 4254 for (ri = 0; ri < md->pmd_npmc; ri++) 4255 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL && 4256 (pm->pm_flags & PMC_F_DESCENDANTS)) { 4257 pmc_link_target_process(pm, ppnew); 4258 po = pm->pm_owner; 4259 if (po->po_sscount == 0 && 4260 po->po_flags & PMC_PO_OWNS_LOGFILE) 4261 pmclog_process_procfork(po, p1->p_pid, 4262 newproc->p_pid); 4263 } 4264 4265 /* 4266 * Now mark the new process as being tracked by this driver. 4267 */ 4268 PROC_LOCK(newproc); 4269 newproc->p_flag |= P_HWPMC; 4270 PROC_UNLOCK(newproc); 4271 4272 done: 4273 sx_xunlock(&pmc_sx); 4274 } 4275 4276 4277 /* 4278 * initialization 4279 */ 4280 4281 static const char *pmc_name_of_pmcclass[] = { 4282 #undef __PMC_CLASS 4283 #define __PMC_CLASS(N) #N , 4284 __PMC_CLASSES() 4285 }; 4286 4287 static int 4288 pmc_initialize(void) 4289 { 4290 int cpu, error, n; 4291 struct pmc_binding pb; 4292 struct pmc_sample *ps; 4293 struct pmc_samplebuffer *sb; 4294 4295 md = NULL; 4296 error = 0; 4297 4298 #ifdef DEBUG 4299 /* parse debug flags first */ 4300 if (TUNABLE_STR_FETCH(PMC_SYSCTL_NAME_PREFIX "debugflags", 4301 pmc_debugstr, sizeof(pmc_debugstr))) 4302 pmc_debugflags_parse(pmc_debugstr, 4303 pmc_debugstr+strlen(pmc_debugstr)); 4304 #endif 4305 4306 PMCDBG(MOD,INI,0, "PMC Initialize (version %x)", PMC_VERSION); 4307 4308 /* check kernel version */ 4309 if (pmc_kernel_version != PMC_VERSION) { 4310 if (pmc_kernel_version == 0) 4311 printf("hwpmc: this kernel has not been compiled with " 4312 "'options HWPMC_HOOKS'.\n"); 4313 else 4314 printf("hwpmc: kernel version (0x%x) does not match " 4315 "module version (0x%x).\n", pmc_kernel_version, 4316 PMC_VERSION); 4317 return EPROGMISMATCH; 4318 } 4319 4320 /* 4321 * check sysctl parameters 4322 */ 4323 4324 if (pmc_hashsize <= 0) { 4325 (void) printf("hwpmc: tunable \"hashsize\"=%d must be " 4326 "greater than zero.\n", pmc_hashsize); 4327 pmc_hashsize = PMC_HASH_SIZE; 4328 } 4329 4330 if (pmc_nsamples <= 0 || pmc_nsamples > 65535) { 4331 (void) printf("hwpmc: tunable \"nsamples\"=%d out of " 4332 "range.\n", pmc_nsamples); 4333 pmc_nsamples = PMC_NSAMPLES; 4334 } 4335 4336 if (pmc_callchaindepth <= 0 || 4337 pmc_callchaindepth > PMC_CALLCHAIN_DEPTH_MAX) { 4338 (void) printf("hwpmc: tunable \"callchaindepth\"=%d out of " 4339 "range.\n", pmc_callchaindepth); 4340 pmc_callchaindepth = PMC_CALLCHAIN_DEPTH; 4341 } 4342 4343 md = pmc_md_initialize(); 4344 4345 if (md == NULL || md->pmd_init == NULL) 4346 return ENOSYS; 4347 4348 /* allocate space for the per-cpu array */ 4349 MALLOC(pmc_pcpu, struct pmc_cpu **, mp_ncpus * sizeof(struct pmc_cpu *), 4350 M_PMC, M_WAITOK|M_ZERO); 4351 4352 /* per-cpu 'saved values' for managing process-mode PMCs */ 4353 MALLOC(pmc_pcpu_saved, pmc_value_t *, 4354 sizeof(pmc_value_t) * mp_ncpus * md->pmd_npmc, M_PMC, M_WAITOK); 4355 4356 /* perform cpu dependent initialization */ 4357 pmc_save_cpu_binding(&pb); 4358 for (cpu = 0; cpu < mp_ncpus; cpu++) { 4359 if (pmc_cpu_is_disabled(cpu)) 4360 continue; 4361 pmc_select_cpu(cpu); 4362 if ((error = md->pmd_init(cpu)) != 0) 4363 break; 4364 } 4365 pmc_restore_cpu_binding(&pb); 4366 4367 if (error != 0) 4368 return error; 4369 4370 /* allocate space for the sample array */ 4371 for (cpu = 0; cpu < mp_ncpus; cpu++) { 4372 if (pmc_cpu_is_disabled(cpu)) 4373 continue; 4374 MALLOC(sb, struct pmc_samplebuffer *, 4375 sizeof(struct pmc_samplebuffer) + 4376 pmc_nsamples * sizeof(struct pmc_sample), M_PMC, 4377 M_WAITOK|M_ZERO); 4378 4379 sb->ps_read = sb->ps_write = sb->ps_samples; 4380 sb->ps_fence = sb->ps_samples + pmc_nsamples; 4381 KASSERT(pmc_pcpu[cpu] != NULL, 4382 ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu)); 4383 4384 MALLOC(sb->ps_callchains, uintptr_t *, 4385 pmc_callchaindepth * pmc_nsamples * sizeof(uintptr_t), 4386 M_PMC, M_WAITOK|M_ZERO); 4387 4388 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++) 4389 ps->ps_pc = sb->ps_callchains + 4390 (n * pmc_callchaindepth); 4391 4392 pmc_pcpu[cpu]->pc_sb = sb; 4393 } 4394 4395 /* allocate space for the row disposition array */ 4396 pmc_pmcdisp = malloc(sizeof(enum pmc_mode) * md->pmd_npmc, 4397 M_PMC, M_WAITOK|M_ZERO); 4398 4399 KASSERT(pmc_pmcdisp != NULL, 4400 ("[pmc,%d] pmcdisp allocation returned NULL", __LINE__)); 4401 4402 /* mark all PMCs as available */ 4403 for (n = 0; n < (int) md->pmd_npmc; n++) 4404 PMC_MARK_ROW_FREE(n); 4405 4406 /* allocate thread hash tables */ 4407 pmc_ownerhash = hashinit(pmc_hashsize, M_PMC, 4408 &pmc_ownerhashmask); 4409 4410 pmc_processhash = hashinit(pmc_hashsize, M_PMC, 4411 &pmc_processhashmask); 4412 mtx_init(&pmc_processhash_mtx, "pmc-process-hash", "pmc-leaf", 4413 MTX_SPIN); 4414 4415 LIST_INIT(&pmc_ss_owners); 4416 pmc_ss_count = 0; 4417 4418 /* allocate a pool of spin mutexes */ 4419 pmc_mtxpool = mtx_pool_create("pmc-leaf", pmc_mtxpool_size, 4420 MTX_SPIN); 4421 4422 PMCDBG(MOD,INI,1, "pmc_ownerhash=%p, mask=0x%lx " 4423 "targethash=%p mask=0x%lx", pmc_ownerhash, pmc_ownerhashmask, 4424 pmc_processhash, pmc_processhashmask); 4425 4426 /* register process {exit,fork,exec} handlers */ 4427 pmc_exit_tag = EVENTHANDLER_REGISTER(process_exit, 4428 pmc_process_exit, NULL, EVENTHANDLER_PRI_ANY); 4429 pmc_fork_tag = EVENTHANDLER_REGISTER(process_fork, 4430 pmc_process_fork, NULL, EVENTHANDLER_PRI_ANY); 4431 4432 /* initialize logging */ 4433 pmclog_initialize(); 4434 4435 /* set hook functions */ 4436 pmc_intr = md->pmd_intr; 4437 pmc_hook = pmc_hook_handler; 4438 4439 if (error == 0) { 4440 printf(PMC_MODULE_NAME ":"); 4441 for (n = 0; n < (int) md->pmd_nclass; n++) { 4442 printf(" %s/%d/0x%b", 4443 pmc_name_of_pmcclass[md->pmd_classes[n].pm_class], 4444 md->pmd_nclasspmcs[n], 4445 md->pmd_classes[n].pm_caps, 4446 "\20" 4447 "\1INT\2USR\3SYS\4EDG\5THR" 4448 "\6REA\7WRI\10INV\11QUA\12PRC" 4449 "\13TAG\14CSC"); 4450 } 4451 printf("\n"); 4452 } 4453 4454 return error; 4455 } 4456 4457 /* prepare to be unloaded */ 4458 static void 4459 pmc_cleanup(void) 4460 { 4461 int cpu; 4462 struct pmc_ownerhash *ph; 4463 struct pmc_owner *po, *tmp; 4464 struct pmc_binding pb; 4465 #ifdef DEBUG 4466 struct pmc_processhash *prh; 4467 #endif 4468 4469 PMCDBG(MOD,INI,0, "%s", "cleanup"); 4470 4471 /* switch off sampling */ 4472 atomic_store_rel_int(&pmc_cpumask, 0); 4473 pmc_intr = NULL; 4474 4475 sx_xlock(&pmc_sx); 4476 if (pmc_hook == NULL) { /* being unloaded already */ 4477 sx_xunlock(&pmc_sx); 4478 return; 4479 } 4480 4481 pmc_hook = NULL; /* prevent new threads from entering module */ 4482 4483 /* deregister event handlers */ 4484 EVENTHANDLER_DEREGISTER(process_fork, pmc_fork_tag); 4485 EVENTHANDLER_DEREGISTER(process_exit, pmc_exit_tag); 4486 4487 /* send SIGBUS to all owner threads, free up allocations */ 4488 if (pmc_ownerhash) 4489 for (ph = pmc_ownerhash; 4490 ph <= &pmc_ownerhash[pmc_ownerhashmask]; 4491 ph++) { 4492 LIST_FOREACH_SAFE(po, ph, po_next, tmp) { 4493 pmc_remove_owner(po); 4494 4495 /* send SIGBUS to owner processes */ 4496 PMCDBG(MOD,INI,2, "cleanup signal proc=%p " 4497 "(%d, %s)", po->po_owner, 4498 po->po_owner->p_pid, 4499 po->po_owner->p_comm); 4500 4501 PROC_LOCK(po->po_owner); 4502 psignal(po->po_owner, SIGBUS); 4503 PROC_UNLOCK(po->po_owner); 4504 4505 pmc_destroy_owner_descriptor(po); 4506 } 4507 } 4508 4509 /* reclaim allocated data structures */ 4510 if (pmc_mtxpool) 4511 mtx_pool_destroy(&pmc_mtxpool); 4512 4513 mtx_destroy(&pmc_processhash_mtx); 4514 if (pmc_processhash) { 4515 #ifdef DEBUG 4516 struct pmc_process *pp; 4517 4518 PMCDBG(MOD,INI,3, "%s", "destroy process hash"); 4519 for (prh = pmc_processhash; 4520 prh <= &pmc_processhash[pmc_processhashmask]; 4521 prh++) 4522 LIST_FOREACH(pp, prh, pp_next) 4523 PMCDBG(MOD,INI,3, "pid=%d", pp->pp_proc->p_pid); 4524 #endif 4525 4526 hashdestroy(pmc_processhash, M_PMC, pmc_processhashmask); 4527 pmc_processhash = NULL; 4528 } 4529 4530 if (pmc_ownerhash) { 4531 PMCDBG(MOD,INI,3, "%s", "destroy owner hash"); 4532 hashdestroy(pmc_ownerhash, M_PMC, pmc_ownerhashmask); 4533 pmc_ownerhash = NULL; 4534 } 4535 4536 KASSERT(LIST_EMPTY(&pmc_ss_owners), 4537 ("[pmc,%d] Global SS owner list not empty", __LINE__)); 4538 KASSERT(pmc_ss_count == 0, 4539 ("[pmc,%d] Global SS count not empty", __LINE__)); 4540 4541 /* free the per-cpu sample buffers */ 4542 for (cpu = 0; cpu < mp_ncpus; cpu++) { 4543 if (pmc_cpu_is_disabled(cpu)) 4544 continue; 4545 KASSERT(pmc_pcpu[cpu]->pc_sb != NULL, 4546 ("[pmc,%d] Null cpu sample buffer cpu=%d", __LINE__, 4547 cpu)); 4548 FREE(pmc_pcpu[cpu]->pc_sb->ps_callchains, M_PMC); 4549 FREE(pmc_pcpu[cpu]->pc_sb, M_PMC); 4550 pmc_pcpu[cpu]->pc_sb = NULL; 4551 } 4552 4553 /* do processor dependent cleanup */ 4554 PMCDBG(MOD,INI,3, "%s", "md cleanup"); 4555 if (md) { 4556 pmc_save_cpu_binding(&pb); 4557 for (cpu = 0; cpu < mp_ncpus; cpu++) { 4558 PMCDBG(MOD,INI,1,"pmc-cleanup cpu=%d pcs=%p", 4559 cpu, pmc_pcpu[cpu]); 4560 if (pmc_cpu_is_disabled(cpu)) 4561 continue; 4562 pmc_select_cpu(cpu); 4563 if (pmc_pcpu[cpu]) 4564 (void) md->pmd_cleanup(cpu); 4565 } 4566 FREE(md, M_PMC); 4567 md = NULL; 4568 pmc_restore_cpu_binding(&pb); 4569 } 4570 4571 /* deallocate per-cpu structures */ 4572 FREE(pmc_pcpu, M_PMC); 4573 pmc_pcpu = NULL; 4574 4575 FREE(pmc_pcpu_saved, M_PMC); 4576 pmc_pcpu_saved = NULL; 4577 4578 if (pmc_pmcdisp) { 4579 FREE(pmc_pmcdisp, M_PMC); 4580 pmc_pmcdisp = NULL; 4581 } 4582 4583 pmclog_shutdown(); 4584 4585 sx_xunlock(&pmc_sx); /* we are done */ 4586 } 4587 4588 /* 4589 * The function called at load/unload. 4590 */ 4591 4592 static int 4593 load (struct module *module __unused, int cmd, void *arg __unused) 4594 { 4595 int error; 4596 4597 error = 0; 4598 4599 switch (cmd) { 4600 case MOD_LOAD : 4601 /* initialize the subsystem */ 4602 error = pmc_initialize(); 4603 if (error != 0) 4604 break; 4605 PMCDBG(MOD,INI,1, "syscall=%d ncpus=%d", 4606 pmc_syscall_num, mp_ncpus); 4607 break; 4608 4609 4610 case MOD_UNLOAD : 4611 case MOD_SHUTDOWN: 4612 pmc_cleanup(); 4613 PMCDBG(MOD,INI,1, "%s", "unloaded"); 4614 break; 4615 4616 default : 4617 error = EINVAL; /* XXX should panic(9) */ 4618 break; 4619 } 4620 4621 return error; 4622 } 4623 4624 /* memory pool */ 4625 MALLOC_DEFINE(M_PMC, "pmc", "Memory space for the PMC module"); 4626