1 /*-
2 * Copyright (c) 2005-2007 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 /*
33 * Logging code for hwpmc(4)
34 */
35
36 #include <sys/cdefs.h>
37 __FBSDID("$FreeBSD$");
38
39 #include <sys/param.h>
40 #if (__FreeBSD_version >= 1100000)
41 #include <sys/capsicum.h>
42 #else
43 #include <sys/capability.h>
44 #endif
45 #include <sys/file.h>
46 #include <sys/kernel.h>
47 #include <sys/kthread.h>
48 #include <sys/lock.h>
49 #include <sys/module.h>
50 #include <sys/mutex.h>
51 #include <sys/pmc.h>
52 #include <sys/pmckern.h>
53 #include <sys/pmclog.h>
54 #include <sys/proc.h>
55 #include <sys/signalvar.h>
56 #include <sys/sysctl.h>
57 #include <sys/systm.h>
58 #include <sys/uio.h>
59 #include <sys/unistd.h>
60 #include <sys/vnode.h>
61
62 /*
63 * Sysctl tunables
64 */
65
66 SYSCTL_DECL(_kern_hwpmc);
67
68 /*
69 * kern.hwpmc.logbuffersize -- size of the per-cpu owner buffers.
70 */
71
72 static int pmclog_buffer_size = PMC_LOG_BUFFER_SIZE;
73 #if (__FreeBSD_version < 1100000)
74 TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "logbuffersize", &pmclog_buffer_size);
75 #endif
76 SYSCTL_INT(_kern_hwpmc, OID_AUTO, logbuffersize, CTLFLAG_RDTUN,
77 &pmclog_buffer_size, 0, "size of log buffers in kilobytes");
78
79 /*
80 * kern.hwpmc.nbuffer -- number of global log buffers
81 */
82
83 static int pmc_nlogbuffers = PMC_NLOGBUFFERS;
84 #if (__FreeBSD_version < 1100000)
85 TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "nbuffers", &pmc_nlogbuffers);
86 #endif
87 SYSCTL_INT(_kern_hwpmc, OID_AUTO, nbuffers, CTLFLAG_RDTUN,
88 &pmc_nlogbuffers, 0, "number of global log buffers");
89
90 /*
91 * Global log buffer list and associated spin lock.
92 */
93
94 TAILQ_HEAD(, pmclog_buffer) pmc_bufferlist =
95 TAILQ_HEAD_INITIALIZER(pmc_bufferlist);
96 static struct mtx pmc_bufferlist_mtx; /* spin lock */
97 static struct mtx pmc_kthread_mtx; /* sleep lock */
98
99 #define PMCLOG_INIT_BUFFER_DESCRIPTOR(D) do { \
100 const int __roundup = roundup(sizeof(*D), \
101 sizeof(uint32_t)); \
102 (D)->plb_fence = ((char *) (D)) + \
103 1024*pmclog_buffer_size; \
104 (D)->plb_base = (D)->plb_ptr = ((char *) (D)) + \
105 __roundup; \
106 } while (0)
107
108
109 /*
110 * Log file record constructors.
111 */
112 #define _PMCLOG_TO_HEADER(T,L) \
113 ((PMCLOG_HEADER_MAGIC << 24) | \
114 (PMCLOG_TYPE_ ## T << 16) | \
115 ((L) & 0xFFFF))
116
117 /* reserve LEN bytes of space and initialize the entry header */
118 #define _PMCLOG_RESERVE(PO,TYPE,LEN,ACTION) do { \
119 uint32_t *_le; \
120 int _len = roundup((LEN), sizeof(uint32_t)); \
121 if ((_le = pmclog_reserve((PO), _len)) == NULL) { \
122 ACTION; \
123 } \
124 *_le = _PMCLOG_TO_HEADER(TYPE,_len); \
125 _le += 3 /* skip over timestamp */
126
127 #define PMCLOG_RESERVE(P,T,L) _PMCLOG_RESERVE(P,T,L,return)
128 #define PMCLOG_RESERVE_WITH_ERROR(P,T,L) _PMCLOG_RESERVE(P,T,L, \
129 error=ENOMEM;goto error)
130
131 #define PMCLOG_EMIT32(V) do { *_le++ = (V); } while (0)
132 #define PMCLOG_EMIT64(V) do { \
133 *_le++ = (uint32_t) ((V) & 0xFFFFFFFF); \
134 *_le++ = (uint32_t) (((V) >> 32) & 0xFFFFFFFF); \
135 } while (0)
136
137
138 /* Emit a string. Caution: does NOT update _le, so needs to be last */
139 #define PMCLOG_EMITSTRING(S,L) do { bcopy((S), _le, (L)); } while (0)
140 #define PMCLOG_EMITNULLSTRING(L) do { bzero(_le, (L)); } while (0)
141
142 #define PMCLOG_DESPATCH(PO) \
143 pmclog_release((PO)); \
144 } while (0)
145
146
147 /*
148 * Assertions about the log file format.
149 */
150
151 CTASSERT(sizeof(struct pmclog_callchain) == 6*4 +
152 PMC_CALLCHAIN_DEPTH_MAX*sizeof(uintfptr_t));
153 CTASSERT(sizeof(struct pmclog_closelog) == 3*4);
154 CTASSERT(sizeof(struct pmclog_dropnotify) == 3*4);
155 CTASSERT(sizeof(struct pmclog_map_in) == PATH_MAX +
156 4*4 + sizeof(uintfptr_t));
157 CTASSERT(offsetof(struct pmclog_map_in,pl_pathname) ==
158 4*4 + sizeof(uintfptr_t));
159 CTASSERT(sizeof(struct pmclog_map_out) == 4*4 + 2*sizeof(uintfptr_t));
160 CTASSERT(sizeof(struct pmclog_pcsample) == 6*4 + sizeof(uintfptr_t));
161 CTASSERT(sizeof(struct pmclog_pmcallocate) == 6*4);
162 CTASSERT(sizeof(struct pmclog_pmcattach) == 5*4 + PATH_MAX);
163 CTASSERT(offsetof(struct pmclog_pmcattach,pl_pathname) == 5*4);
164 CTASSERT(sizeof(struct pmclog_pmcdetach) == 5*4);
165 CTASSERT(sizeof(struct pmclog_proccsw) == 5*4 + 8);
166 CTASSERT(sizeof(struct pmclog_procexec) == 5*4 + PATH_MAX +
167 sizeof(uintfptr_t));
168 CTASSERT(offsetof(struct pmclog_procexec,pl_pathname) == 5*4 +
169 sizeof(uintfptr_t));
170 CTASSERT(sizeof(struct pmclog_procexit) == 5*4 + 8);
171 CTASSERT(sizeof(struct pmclog_procfork) == 5*4);
172 CTASSERT(sizeof(struct pmclog_sysexit) == 4*4);
173 CTASSERT(sizeof(struct pmclog_userdata) == 4*4);
174
175 /*
176 * Log buffer structure
177 */
178
179 struct pmclog_buffer {
180 TAILQ_ENTRY(pmclog_buffer) plb_next;
181 char *plb_base;
182 char *plb_ptr;
183 char *plb_fence;
184 };
185
186 /*
187 * Prototypes
188 */
189
190 static int pmclog_get_buffer(struct pmc_owner *po);
191 static void pmclog_loop(void *arg);
192 static void pmclog_release(struct pmc_owner *po);
193 static uint32_t *pmclog_reserve(struct pmc_owner *po, int length);
194 static void pmclog_schedule_io(struct pmc_owner *po);
195 static void pmclog_stop_kthread(struct pmc_owner *po);
196
197 /*
198 * Helper functions
199 */
200
201 /*
202 * Get a log buffer
203 */
204
205 static int
pmclog_get_buffer(struct pmc_owner * po)206 pmclog_get_buffer(struct pmc_owner *po)
207 {
208 struct pmclog_buffer *plb;
209
210 mtx_assert(&po->po_mtx, MA_OWNED);
211
212 KASSERT(po->po_curbuf == NULL,
213 ("[pmclog,%d] po=%p current buffer still valid", __LINE__, po));
214
215 mtx_lock_spin(&pmc_bufferlist_mtx);
216 if ((plb = TAILQ_FIRST(&pmc_bufferlist)) != NULL)
217 TAILQ_REMOVE(&pmc_bufferlist, plb, plb_next);
218 mtx_unlock_spin(&pmc_bufferlist_mtx);
219
220 PMCDBG2(LOG,GTB,1, "po=%p plb=%p", po, plb);
221
222 #ifdef HWPMC_DEBUG
223 if (plb)
224 KASSERT(plb->plb_ptr == plb->plb_base &&
225 plb->plb_base < plb->plb_fence,
226 ("[pmclog,%d] po=%p buffer invariants: ptr=%p "
227 "base=%p fence=%p", __LINE__, po, plb->plb_ptr,
228 plb->plb_base, plb->plb_fence));
229 #endif
230
231 po->po_curbuf = plb;
232
233 /* update stats */
234 atomic_add_int(&pmc_stats.pm_buffer_requests, 1);
235 if (plb == NULL)
236 atomic_add_int(&pmc_stats.pm_buffer_requests_failed, 1);
237
238 return (plb ? 0 : ENOMEM);
239 }
240
241 /*
242 * Log handler loop.
243 *
244 * This function is executed by each pmc owner's helper thread.
245 */
246
247 static void
pmclog_loop(void * arg)248 pmclog_loop(void *arg)
249 {
250 int error;
251 struct pmc_owner *po;
252 struct pmclog_buffer *lb;
253 struct proc *p;
254 struct ucred *ownercred;
255 struct ucred *mycred;
256 struct thread *td;
257 struct uio auio;
258 struct iovec aiov;
259 size_t nbytes;
260
261 po = (struct pmc_owner *) arg;
262 p = po->po_owner;
263 td = curthread;
264 mycred = td->td_ucred;
265
266 PROC_LOCK(p);
267 ownercred = crhold(p->p_ucred);
268 PROC_UNLOCK(p);
269
270 PMCDBG2(LOG,INI,1, "po=%p kt=%p", po, po->po_kthread);
271 KASSERT(po->po_kthread == curthread->td_proc,
272 ("[pmclog,%d] proc mismatch po=%p po/kt=%p curproc=%p", __LINE__,
273 po, po->po_kthread, curthread->td_proc));
274
275 lb = NULL;
276
277
278 /*
279 * Loop waiting for I/O requests to be added to the owner
280 * struct's queue. The loop is exited when the log file
281 * is deconfigured.
282 */
283
284 mtx_lock(&pmc_kthread_mtx);
285
286 for (;;) {
287
288 /* check if we've been asked to exit */
289 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0)
290 break;
291
292 if (lb == NULL) { /* look for a fresh buffer to write */
293 mtx_lock_spin(&po->po_mtx);
294 if ((lb = TAILQ_FIRST(&po->po_logbuffers)) == NULL) {
295 mtx_unlock_spin(&po->po_mtx);
296
297 /* No more buffers and shutdown required. */
298 if (po->po_flags & PMC_PO_SHUTDOWN) {
299 mtx_unlock(&pmc_kthread_mtx);
300 /*
301 * Close the file to get PMCLOG_EOF
302 * error in pmclog(3).
303 */
304 fo_close(po->po_file, curthread);
305 mtx_lock(&pmc_kthread_mtx);
306 break;
307 }
308
309 (void) msleep(po, &pmc_kthread_mtx, PWAIT,
310 "pmcloop", 0);
311 continue;
312 }
313
314 TAILQ_REMOVE(&po->po_logbuffers, lb, plb_next);
315 mtx_unlock_spin(&po->po_mtx);
316 }
317
318 mtx_unlock(&pmc_kthread_mtx);
319
320 /* process the request */
321 PMCDBG3(LOG,WRI,2, "po=%p base=%p ptr=%p", po,
322 lb->plb_base, lb->plb_ptr);
323 /* change our thread's credentials before issuing the I/O */
324
325 aiov.iov_base = lb->plb_base;
326 aiov.iov_len = nbytes = lb->plb_ptr - lb->plb_base;
327
328 auio.uio_iov = &aiov;
329 auio.uio_iovcnt = 1;
330 auio.uio_offset = -1;
331 auio.uio_resid = nbytes;
332 auio.uio_rw = UIO_WRITE;
333 auio.uio_segflg = UIO_SYSSPACE;
334 auio.uio_td = td;
335
336 /* switch thread credentials -- see kern_ktrace.c */
337 td->td_ucred = ownercred;
338 error = fo_write(po->po_file, &auio, ownercred, 0, td);
339 td->td_ucred = mycred;
340
341 if (error) {
342 /* XXX some errors are recoverable */
343 /* send a SIGIO to the owner and exit */
344 PROC_LOCK(p);
345 kern_psignal(p, SIGIO);
346 PROC_UNLOCK(p);
347
348 mtx_lock(&pmc_kthread_mtx);
349
350 po->po_error = error; /* save for flush log */
351
352 PMCDBG2(LOG,WRI,2, "po=%p error=%d", po, error);
353
354 break;
355 }
356
357 mtx_lock(&pmc_kthread_mtx);
358
359 /* put the used buffer back into the global pool */
360 PMCLOG_INIT_BUFFER_DESCRIPTOR(lb);
361
362 mtx_lock_spin(&pmc_bufferlist_mtx);
363 TAILQ_INSERT_HEAD(&pmc_bufferlist, lb, plb_next);
364 mtx_unlock_spin(&pmc_bufferlist_mtx);
365
366 lb = NULL;
367 }
368
369 wakeup_one(po->po_kthread);
370 po->po_kthread = NULL;
371
372 mtx_unlock(&pmc_kthread_mtx);
373
374 /* return the current I/O buffer to the global pool */
375 if (lb) {
376 PMCLOG_INIT_BUFFER_DESCRIPTOR(lb);
377
378 mtx_lock_spin(&pmc_bufferlist_mtx);
379 TAILQ_INSERT_HEAD(&pmc_bufferlist, lb, plb_next);
380 mtx_unlock_spin(&pmc_bufferlist_mtx);
381 }
382
383 /*
384 * Exit this thread, signalling the waiter
385 */
386
387 crfree(ownercred);
388
389 kproc_exit(0);
390 }
391
392 /*
393 * Release and log entry and schedule an I/O if needed.
394 */
395
396 static void
pmclog_release(struct pmc_owner * po)397 pmclog_release(struct pmc_owner *po)
398 {
399 KASSERT(po->po_curbuf->plb_ptr >= po->po_curbuf->plb_base,
400 ("[pmclog,%d] buffer invariants po=%p ptr=%p base=%p", __LINE__,
401 po, po->po_curbuf->plb_ptr, po->po_curbuf->plb_base));
402 KASSERT(po->po_curbuf->plb_ptr <= po->po_curbuf->plb_fence,
403 ("[pmclog,%d] buffer invariants po=%p ptr=%p fenc=%p", __LINE__,
404 po, po->po_curbuf->plb_ptr, po->po_curbuf->plb_fence));
405
406 /* schedule an I/O if we've filled a buffer */
407 if (po->po_curbuf->plb_ptr >= po->po_curbuf->plb_fence)
408 pmclog_schedule_io(po);
409
410 mtx_unlock_spin(&po->po_mtx);
411
412 PMCDBG1(LOG,REL,1, "po=%p", po);
413 }
414
415
416 /*
417 * Attempt to reserve 'length' bytes of space in an owner's log
418 * buffer. The function returns a pointer to 'length' bytes of space
419 * if there was enough space or returns NULL if no space was
420 * available. Non-null returns do so with the po mutex locked. The
421 * caller must invoke pmclog_release() on the pmc owner structure
422 * when done.
423 */
424
425 static uint32_t *
pmclog_reserve(struct pmc_owner * po,int length)426 pmclog_reserve(struct pmc_owner *po, int length)
427 {
428 uintptr_t newptr, oldptr;
429 uint32_t *lh;
430 struct timespec ts;
431
432 PMCDBG2(LOG,ALL,1, "po=%p len=%d", po, length);
433
434 KASSERT(length % sizeof(uint32_t) == 0,
435 ("[pmclog,%d] length not a multiple of word size", __LINE__));
436
437 mtx_lock_spin(&po->po_mtx);
438
439 /* No more data when shutdown in progress. */
440 if (po->po_flags & PMC_PO_SHUTDOWN) {
441 mtx_unlock_spin(&po->po_mtx);
442 return (NULL);
443 }
444
445 if (po->po_curbuf == NULL)
446 if (pmclog_get_buffer(po) != 0) {
447 mtx_unlock_spin(&po->po_mtx);
448 return (NULL);
449 }
450
451 KASSERT(po->po_curbuf != NULL,
452 ("[pmclog,%d] po=%p no current buffer", __LINE__, po));
453
454 KASSERT(po->po_curbuf->plb_ptr >= po->po_curbuf->plb_base &&
455 po->po_curbuf->plb_ptr <= po->po_curbuf->plb_fence,
456 ("[pmclog,%d] po=%p buffer invariants: ptr=%p base=%p fence=%p",
457 __LINE__, po, po->po_curbuf->plb_ptr, po->po_curbuf->plb_base,
458 po->po_curbuf->plb_fence));
459
460 oldptr = (uintptr_t) po->po_curbuf->plb_ptr;
461 newptr = oldptr + length;
462
463 KASSERT(oldptr != (uintptr_t) NULL,
464 ("[pmclog,%d] po=%p Null log buffer pointer", __LINE__, po));
465
466 /*
467 * If we have space in the current buffer, return a pointer to
468 * available space with the PO structure locked.
469 */
470 if (newptr <= (uintptr_t) po->po_curbuf->plb_fence) {
471 po->po_curbuf->plb_ptr = (char *) newptr;
472 goto done;
473 }
474
475 /*
476 * Otherwise, schedule the current buffer for output and get a
477 * fresh buffer.
478 */
479 pmclog_schedule_io(po);
480
481 if (pmclog_get_buffer(po) != 0) {
482 mtx_unlock_spin(&po->po_mtx);
483 return (NULL);
484 }
485
486 KASSERT(po->po_curbuf != NULL,
487 ("[pmclog,%d] po=%p no current buffer", __LINE__, po));
488
489 KASSERT(po->po_curbuf->plb_ptr != NULL,
490 ("[pmclog,%d] null return from pmc_get_log_buffer", __LINE__));
491
492 KASSERT(po->po_curbuf->plb_ptr == po->po_curbuf->plb_base &&
493 po->po_curbuf->plb_ptr <= po->po_curbuf->plb_fence,
494 ("[pmclog,%d] po=%p buffer invariants: ptr=%p base=%p fence=%p",
495 __LINE__, po, po->po_curbuf->plb_ptr, po->po_curbuf->plb_base,
496 po->po_curbuf->plb_fence));
497
498 oldptr = (uintptr_t) po->po_curbuf->plb_ptr;
499
500 done:
501 lh = (uint32_t *) oldptr;
502 lh++; /* skip header */
503 getnanotime(&ts); /* fill in the timestamp */
504 *lh++ = ts.tv_sec & 0xFFFFFFFF;
505 *lh++ = ts.tv_nsec & 0xFFFFFFF;
506 return ((uint32_t *) oldptr);
507 }
508
509 /*
510 * Schedule an I/O.
511 *
512 * Transfer the current buffer to the helper kthread.
513 */
514
515 static void
pmclog_schedule_io(struct pmc_owner * po)516 pmclog_schedule_io(struct pmc_owner *po)
517 {
518 KASSERT(po->po_curbuf != NULL,
519 ("[pmclog,%d] schedule_io with null buffer po=%p", __LINE__, po));
520
521 KASSERT(po->po_curbuf->plb_ptr >= po->po_curbuf->plb_base,
522 ("[pmclog,%d] buffer invariants po=%p ptr=%p base=%p", __LINE__,
523 po, po->po_curbuf->plb_ptr, po->po_curbuf->plb_base));
524 KASSERT(po->po_curbuf->plb_ptr <= po->po_curbuf->plb_fence,
525 ("[pmclog,%d] buffer invariants po=%p ptr=%p fenc=%p", __LINE__,
526 po, po->po_curbuf->plb_ptr, po->po_curbuf->plb_fence));
527
528 PMCDBG1(LOG,SIO, 1, "po=%p", po);
529
530 mtx_assert(&po->po_mtx, MA_OWNED);
531
532 /*
533 * Add the current buffer to the tail of the buffer list and
534 * wakeup the helper.
535 */
536 TAILQ_INSERT_TAIL(&po->po_logbuffers, po->po_curbuf, plb_next);
537 po->po_curbuf = NULL;
538 wakeup_one(po);
539 }
540
541 /*
542 * Stop the helper kthread.
543 */
544
545 static void
pmclog_stop_kthread(struct pmc_owner * po)546 pmclog_stop_kthread(struct pmc_owner *po)
547 {
548 /*
549 * Close the file to force the thread out of fo_write,
550 * unset flag, wakeup the helper thread,
551 * wait for it to exit
552 */
553
554 if (po->po_file != NULL)
555 fo_close(po->po_file, curthread);
556
557 mtx_lock(&pmc_kthread_mtx);
558 po->po_flags &= ~PMC_PO_OWNS_LOGFILE;
559 wakeup_one(po);
560 if (po->po_kthread)
561 msleep(po->po_kthread, &pmc_kthread_mtx, PPAUSE, "pmckstp", 0);
562 mtx_unlock(&pmc_kthread_mtx);
563 }
564
565 /*
566 * Public functions
567 */
568
569 /*
570 * Configure a log file for pmc owner 'po'.
571 *
572 * Parameter 'logfd' is a file handle referencing an open file in the
573 * owner process. This file needs to have been opened for writing.
574 */
575
576 int
pmclog_configure_log(struct pmc_mdep * md,struct pmc_owner * po,int logfd)577 pmclog_configure_log(struct pmc_mdep *md, struct pmc_owner *po, int logfd)
578 {
579 int error;
580 struct proc *p;
581 cap_rights_t rights;
582 /*
583 * As long as it is possible to get a LOR between pmc_sx lock and
584 * proctree/allproc sx locks used for adding a new process, assure
585 * the former is not held here.
586 */
587 sx_assert(&pmc_sx, SA_UNLOCKED);
588 PMCDBG2(LOG,CFG,1, "config po=%p logfd=%d", po, logfd);
589
590 p = po->po_owner;
591
592 /* return EBUSY if a log file was already present */
593 if (po->po_flags & PMC_PO_OWNS_LOGFILE)
594 return (EBUSY);
595
596 KASSERT(po->po_kthread == NULL,
597 ("[pmclog,%d] po=%p kthread (%p) already present", __LINE__, po,
598 po->po_kthread));
599 KASSERT(po->po_file == NULL,
600 ("[pmclog,%d] po=%p file (%p) already present", __LINE__, po,
601 po->po_file));
602
603 /* get a reference to the file state */
604 error = fget_write(curthread, logfd,
605 cap_rights_init(&rights, CAP_WRITE), &po->po_file);
606 if (error)
607 goto error;
608
609 /* mark process as owning a log file */
610 po->po_flags |= PMC_PO_OWNS_LOGFILE;
611 error = kproc_create(pmclog_loop, po, &po->po_kthread,
612 RFHIGHPID, 0, "hwpmc: proc(%d)", p->p_pid);
613 if (error)
614 goto error;
615
616 /* mark process as using HWPMCs */
617 PROC_LOCK(p);
618 p->p_flag |= P_HWPMC;
619 PROC_UNLOCK(p);
620
621 /* create a log initialization entry */
622 PMCLOG_RESERVE_WITH_ERROR(po, INITIALIZE,
623 sizeof(struct pmclog_initialize));
624 PMCLOG_EMIT32(PMC_VERSION);
625 PMCLOG_EMIT32(md->pmd_cputype);
626 PMCLOG_DESPATCH(po);
627
628 return (0);
629
630 error:
631 /* shutdown the thread */
632 if (po->po_kthread)
633 pmclog_stop_kthread(po);
634
635 KASSERT(po->po_kthread == NULL, ("[pmclog,%d] po=%p kthread not "
636 "stopped", __LINE__, po));
637
638 if (po->po_file)
639 (void) fdrop(po->po_file, curthread);
640 po->po_file = NULL; /* clear file and error state */
641 po->po_error = 0;
642
643 return (error);
644 }
645
646
647 /*
648 * De-configure a log file. This will throw away any buffers queued
649 * for this owner process.
650 */
651
652 int
pmclog_deconfigure_log(struct pmc_owner * po)653 pmclog_deconfigure_log(struct pmc_owner *po)
654 {
655 int error;
656 struct pmclog_buffer *lb;
657
658 PMCDBG1(LOG,CFG,1, "de-config po=%p", po);
659
660 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0)
661 return (EINVAL);
662
663 KASSERT(po->po_sscount == 0,
664 ("[pmclog,%d] po=%p still owning SS PMCs", __LINE__, po));
665 KASSERT(po->po_file != NULL,
666 ("[pmclog,%d] po=%p no log file", __LINE__, po));
667
668 /* stop the kthread, this will reset the 'OWNS_LOGFILE' flag */
669 pmclog_stop_kthread(po);
670
671 KASSERT(po->po_kthread == NULL,
672 ("[pmclog,%d] po=%p kthread not stopped", __LINE__, po));
673
674 /* return all queued log buffers to the global pool */
675 while ((lb = TAILQ_FIRST(&po->po_logbuffers)) != NULL) {
676 TAILQ_REMOVE(&po->po_logbuffers, lb, plb_next);
677 PMCLOG_INIT_BUFFER_DESCRIPTOR(lb);
678 mtx_lock_spin(&pmc_bufferlist_mtx);
679 TAILQ_INSERT_HEAD(&pmc_bufferlist, lb, plb_next);
680 mtx_unlock_spin(&pmc_bufferlist_mtx);
681 }
682
683 /* return the 'current' buffer to the global pool */
684 if ((lb = po->po_curbuf) != NULL) {
685 PMCLOG_INIT_BUFFER_DESCRIPTOR(lb);
686 mtx_lock_spin(&pmc_bufferlist_mtx);
687 TAILQ_INSERT_HEAD(&pmc_bufferlist, lb, plb_next);
688 mtx_unlock_spin(&pmc_bufferlist_mtx);
689 }
690
691 /* drop a reference to the fd */
692 error = fdrop(po->po_file, curthread);
693 po->po_file = NULL;
694 po->po_error = 0;
695
696 return (error);
697 }
698
699 /*
700 * Flush a process' log buffer.
701 */
702
703 int
pmclog_flush(struct pmc_owner * po)704 pmclog_flush(struct pmc_owner *po)
705 {
706 int error;
707 struct pmclog_buffer *lb;
708
709 PMCDBG1(LOG,FLS,1, "po=%p", po);
710
711 /*
712 * If there is a pending error recorded by the logger thread,
713 * return that.
714 */
715 if (po->po_error)
716 return (po->po_error);
717
718 error = 0;
719
720 /*
721 * Check that we do have an active log file.
722 */
723 mtx_lock(&pmc_kthread_mtx);
724 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) {
725 error = EINVAL;
726 goto error;
727 }
728
729 /*
730 * Schedule the current buffer if any and not empty.
731 */
732 mtx_lock_spin(&po->po_mtx);
733 lb = po->po_curbuf;
734 if (lb && lb->plb_ptr != lb->plb_base) {
735 pmclog_schedule_io(po);
736 } else
737 error = ENOBUFS;
738 mtx_unlock_spin(&po->po_mtx);
739
740 error:
741 mtx_unlock(&pmc_kthread_mtx);
742
743 return (error);
744 }
745
746 int
pmclog_close(struct pmc_owner * po)747 pmclog_close(struct pmc_owner *po)
748 {
749
750 PMCDBG1(LOG,CLO,1, "po=%p", po);
751
752 mtx_lock(&pmc_kthread_mtx);
753
754 /*
755 * Schedule the current buffer.
756 */
757 mtx_lock_spin(&po->po_mtx);
758 if (po->po_curbuf)
759 pmclog_schedule_io(po);
760 else
761 wakeup_one(po);
762 mtx_unlock_spin(&po->po_mtx);
763
764 /*
765 * Initiate shutdown: no new data queued,
766 * thread will close file on last block.
767 */
768 po->po_flags |= PMC_PO_SHUTDOWN;
769
770 mtx_unlock(&pmc_kthread_mtx);
771
772 return (0);
773 }
774
775 void
pmclog_process_callchain(struct pmc * pm,struct pmc_sample * ps)776 pmclog_process_callchain(struct pmc *pm, struct pmc_sample *ps)
777 {
778 int n, recordlen;
779 uint32_t flags;
780 struct pmc_owner *po;
781
782 PMCDBG3(LOG,SAM,1,"pm=%p pid=%d n=%d", pm, ps->ps_pid,
783 ps->ps_nsamples);
784
785 recordlen = offsetof(struct pmclog_callchain, pl_pc) +
786 ps->ps_nsamples * sizeof(uintfptr_t);
787 po = pm->pm_owner;
788 flags = PMC_CALLCHAIN_TO_CPUFLAGS(ps->ps_cpu,ps->ps_flags);
789 PMCLOG_RESERVE(po, CALLCHAIN, recordlen);
790 PMCLOG_EMIT32(ps->ps_pid);
791 PMCLOG_EMIT32(pm->pm_id);
792 PMCLOG_EMIT32(flags);
793 for (n = 0; n < ps->ps_nsamples; n++)
794 PMCLOG_EMITADDR(ps->ps_pc[n]);
795 PMCLOG_DESPATCH(po);
796 }
797
798 void
pmclog_process_closelog(struct pmc_owner * po)799 pmclog_process_closelog(struct pmc_owner *po)
800 {
801 PMCLOG_RESERVE(po,CLOSELOG,sizeof(struct pmclog_closelog));
802 PMCLOG_DESPATCH(po);
803 }
804
805 void
pmclog_process_dropnotify(struct pmc_owner * po)806 pmclog_process_dropnotify(struct pmc_owner *po)
807 {
808 PMCLOG_RESERVE(po,DROPNOTIFY,sizeof(struct pmclog_dropnotify));
809 PMCLOG_DESPATCH(po);
810 }
811
812 void
pmclog_process_map_in(struct pmc_owner * po,pid_t pid,uintfptr_t start,const char * path)813 pmclog_process_map_in(struct pmc_owner *po, pid_t pid, uintfptr_t start,
814 const char *path)
815 {
816 int pathlen, recordlen;
817
818 KASSERT(path != NULL, ("[pmclog,%d] map-in, null path", __LINE__));
819
820 pathlen = strlen(path) + 1; /* #bytes for path name */
821 recordlen = offsetof(struct pmclog_map_in, pl_pathname) +
822 pathlen;
823
824 PMCLOG_RESERVE(po, MAP_IN, recordlen);
825 PMCLOG_EMIT32(pid);
826 PMCLOG_EMITADDR(start);
827 PMCLOG_EMITSTRING(path,pathlen);
828 PMCLOG_DESPATCH(po);
829 }
830
831 void
pmclog_process_map_out(struct pmc_owner * po,pid_t pid,uintfptr_t start,uintfptr_t end)832 pmclog_process_map_out(struct pmc_owner *po, pid_t pid, uintfptr_t start,
833 uintfptr_t end)
834 {
835 KASSERT(start <= end, ("[pmclog,%d] start > end", __LINE__));
836
837 PMCLOG_RESERVE(po, MAP_OUT, sizeof(struct pmclog_map_out));
838 PMCLOG_EMIT32(pid);
839 PMCLOG_EMITADDR(start);
840 PMCLOG_EMITADDR(end);
841 PMCLOG_DESPATCH(po);
842 }
843
844 void
pmclog_process_pmcallocate(struct pmc * pm)845 pmclog_process_pmcallocate(struct pmc *pm)
846 {
847 struct pmc_owner *po;
848 struct pmc_soft *ps;
849
850 po = pm->pm_owner;
851
852 PMCDBG1(LOG,ALL,1, "pm=%p", pm);
853
854 if (PMC_TO_CLASS(pm) == PMC_CLASS_SOFT) {
855 PMCLOG_RESERVE(po, PMCALLOCATEDYN,
856 sizeof(struct pmclog_pmcallocatedyn));
857 PMCLOG_EMIT32(pm->pm_id);
858 PMCLOG_EMIT32(pm->pm_event);
859 PMCLOG_EMIT32(pm->pm_flags);
860 ps = pmc_soft_ev_acquire(pm->pm_event);
861 if (ps != NULL)
862 PMCLOG_EMITSTRING(ps->ps_ev.pm_ev_name,PMC_NAME_MAX);
863 else
864 PMCLOG_EMITNULLSTRING(PMC_NAME_MAX);
865 pmc_soft_ev_release(ps);
866 PMCLOG_DESPATCH(po);
867 } else {
868 PMCLOG_RESERVE(po, PMCALLOCATE,
869 sizeof(struct pmclog_pmcallocate));
870 PMCLOG_EMIT32(pm->pm_id);
871 PMCLOG_EMIT32(pm->pm_event);
872 PMCLOG_EMIT32(pm->pm_flags);
873 PMCLOG_DESPATCH(po);
874 }
875 }
876
877 void
pmclog_process_pmcattach(struct pmc * pm,pid_t pid,char * path)878 pmclog_process_pmcattach(struct pmc *pm, pid_t pid, char *path)
879 {
880 int pathlen, recordlen;
881 struct pmc_owner *po;
882
883 PMCDBG2(LOG,ATT,1,"pm=%p pid=%d", pm, pid);
884
885 po = pm->pm_owner;
886
887 pathlen = strlen(path) + 1; /* #bytes for the string */
888 recordlen = offsetof(struct pmclog_pmcattach, pl_pathname) + pathlen;
889
890 PMCLOG_RESERVE(po, PMCATTACH, recordlen);
891 PMCLOG_EMIT32(pm->pm_id);
892 PMCLOG_EMIT32(pid);
893 PMCLOG_EMITSTRING(path, pathlen);
894 PMCLOG_DESPATCH(po);
895 }
896
897 void
pmclog_process_pmcdetach(struct pmc * pm,pid_t pid)898 pmclog_process_pmcdetach(struct pmc *pm, pid_t pid)
899 {
900 struct pmc_owner *po;
901
902 PMCDBG2(LOG,ATT,1,"!pm=%p pid=%d", pm, pid);
903
904 po = pm->pm_owner;
905
906 PMCLOG_RESERVE(po, PMCDETACH, sizeof(struct pmclog_pmcdetach));
907 PMCLOG_EMIT32(pm->pm_id);
908 PMCLOG_EMIT32(pid);
909 PMCLOG_DESPATCH(po);
910 }
911
912 /*
913 * Log a context switch event to the log file.
914 */
915
916 void
pmclog_process_proccsw(struct pmc * pm,struct pmc_process * pp,pmc_value_t v)917 pmclog_process_proccsw(struct pmc *pm, struct pmc_process *pp, pmc_value_t v)
918 {
919 struct pmc_owner *po;
920
921 KASSERT(pm->pm_flags & PMC_F_LOG_PROCCSW,
922 ("[pmclog,%d] log-process-csw called gratuitously", __LINE__));
923
924 PMCDBG3(LOG,SWO,1,"pm=%p pid=%d v=%jx", pm, pp->pp_proc->p_pid,
925 v);
926
927 po = pm->pm_owner;
928
929 PMCLOG_RESERVE(po, PROCCSW, sizeof(struct pmclog_proccsw));
930 PMCLOG_EMIT32(pm->pm_id);
931 PMCLOG_EMIT64(v);
932 PMCLOG_EMIT32(pp->pp_proc->p_pid);
933 PMCLOG_DESPATCH(po);
934 }
935
936 void
pmclog_process_procexec(struct pmc_owner * po,pmc_id_t pmid,pid_t pid,uintfptr_t startaddr,char * path)937 pmclog_process_procexec(struct pmc_owner *po, pmc_id_t pmid, pid_t pid,
938 uintfptr_t startaddr, char *path)
939 {
940 int pathlen, recordlen;
941
942 PMCDBG3(LOG,EXC,1,"po=%p pid=%d path=\"%s\"", po, pid, path);
943
944 pathlen = strlen(path) + 1; /* #bytes for the path */
945 recordlen = offsetof(struct pmclog_procexec, pl_pathname) + pathlen;
946
947 PMCLOG_RESERVE(po, PROCEXEC, recordlen);
948 PMCLOG_EMIT32(pid);
949 PMCLOG_EMITADDR(startaddr);
950 PMCLOG_EMIT32(pmid);
951 PMCLOG_EMITSTRING(path,pathlen);
952 PMCLOG_DESPATCH(po);
953 }
954
955 /*
956 * Log a process exit event (and accumulated pmc value) to the log file.
957 */
958
959 void
pmclog_process_procexit(struct pmc * pm,struct pmc_process * pp)960 pmclog_process_procexit(struct pmc *pm, struct pmc_process *pp)
961 {
962 int ri;
963 struct pmc_owner *po;
964
965 ri = PMC_TO_ROWINDEX(pm);
966 PMCDBG3(LOG,EXT,1,"pm=%p pid=%d v=%jx", pm, pp->pp_proc->p_pid,
967 pp->pp_pmcs[ri].pp_pmcval);
968
969 po = pm->pm_owner;
970
971 PMCLOG_RESERVE(po, PROCEXIT, sizeof(struct pmclog_procexit));
972 PMCLOG_EMIT32(pm->pm_id);
973 PMCLOG_EMIT64(pp->pp_pmcs[ri].pp_pmcval);
974 PMCLOG_EMIT32(pp->pp_proc->p_pid);
975 PMCLOG_DESPATCH(po);
976 }
977
978 /*
979 * Log a fork event.
980 */
981
982 void
pmclog_process_procfork(struct pmc_owner * po,pid_t oldpid,pid_t newpid)983 pmclog_process_procfork(struct pmc_owner *po, pid_t oldpid, pid_t newpid)
984 {
985 PMCLOG_RESERVE(po, PROCFORK, sizeof(struct pmclog_procfork));
986 PMCLOG_EMIT32(oldpid);
987 PMCLOG_EMIT32(newpid);
988 PMCLOG_DESPATCH(po);
989 }
990
991 /*
992 * Log a process exit event of the form suitable for system-wide PMCs.
993 */
994
995 void
pmclog_process_sysexit(struct pmc_owner * po,pid_t pid)996 pmclog_process_sysexit(struct pmc_owner *po, pid_t pid)
997 {
998 PMCLOG_RESERVE(po, SYSEXIT, sizeof(struct pmclog_sysexit));
999 PMCLOG_EMIT32(pid);
1000 PMCLOG_DESPATCH(po);
1001 }
1002
1003 /*
1004 * Write a user log entry.
1005 */
1006
1007 int
pmclog_process_userlog(struct pmc_owner * po,struct pmc_op_writelog * wl)1008 pmclog_process_userlog(struct pmc_owner *po, struct pmc_op_writelog *wl)
1009 {
1010 int error;
1011
1012 PMCDBG2(LOG,WRI,1, "writelog po=%p ud=0x%x", po, wl->pm_userdata);
1013
1014 error = 0;
1015
1016 PMCLOG_RESERVE_WITH_ERROR(po, USERDATA,
1017 sizeof(struct pmclog_userdata));
1018 PMCLOG_EMIT32(wl->pm_userdata);
1019 PMCLOG_DESPATCH(po);
1020
1021 error:
1022 return (error);
1023 }
1024
1025 /*
1026 * Initialization.
1027 *
1028 * Create a pool of log buffers and initialize mutexes.
1029 */
1030
1031 void
pmclog_initialize()1032 pmclog_initialize()
1033 {
1034 int n;
1035 struct pmclog_buffer *plb;
1036
1037 if (pmclog_buffer_size <= 0) {
1038 (void) printf("hwpmc: tunable logbuffersize=%d must be "
1039 "greater than zero.\n", pmclog_buffer_size);
1040 pmclog_buffer_size = PMC_LOG_BUFFER_SIZE;
1041 }
1042
1043 if (pmc_nlogbuffers <= 0) {
1044 (void) printf("hwpmc: tunable nlogbuffers=%d must be greater "
1045 "than zero.\n", pmc_nlogbuffers);
1046 pmc_nlogbuffers = PMC_NLOGBUFFERS;
1047 }
1048
1049 /* create global pool of log buffers */
1050 for (n = 0; n < pmc_nlogbuffers; n++) {
1051 plb = malloc(1024 * pmclog_buffer_size, M_PMC,
1052 M_WAITOK|M_ZERO);
1053 PMCLOG_INIT_BUFFER_DESCRIPTOR(plb);
1054 TAILQ_INSERT_HEAD(&pmc_bufferlist, plb, plb_next);
1055 }
1056 mtx_init(&pmc_bufferlist_mtx, "pmc-buffer-list", "pmc-leaf",
1057 MTX_SPIN);
1058 mtx_init(&pmc_kthread_mtx, "pmc-kthread", "pmc-sleep", MTX_DEF);
1059 }
1060
1061 /*
1062 * Shutdown logging.
1063 *
1064 * Destroy mutexes and release memory back the to free pool.
1065 */
1066
1067 void
pmclog_shutdown()1068 pmclog_shutdown()
1069 {
1070 struct pmclog_buffer *plb;
1071
1072 mtx_destroy(&pmc_kthread_mtx);
1073 mtx_destroy(&pmc_bufferlist_mtx);
1074
1075 while ((plb = TAILQ_FIRST(&pmc_bufferlist)) != NULL) {
1076 TAILQ_REMOVE(&pmc_bufferlist, plb, plb_next);
1077 free(plb, M_PMC);
1078 }
1079 }
1080