xref: /freebsd/usr.sbin/pmcstat/pmcpl_gprof.c (revision eb69d1f144a6fcc765d1b9d44a5ae8082353e70b)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2005-2007, Joseph Koshy
5  * Copyright (c) 2007 The FreeBSD Foundation
6  * Copyright (c) 2009, Fabien Thomas
7  * All rights reserved.
8  *
9  * Portions of this software were developed by A. Joseph Koshy under
10  * sponsorship from the FreeBSD Foundation and Google, Inc.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 /*
35  * Transform a hwpmc(4) log into human readable form, and into
36  * gprof(1) compatible profiles.
37  */
38 
39 #include <sys/cdefs.h>
40 __FBSDID("$FreeBSD$");
41 
42 #include <sys/param.h>
43 #include <sys/endian.h>
44 #include <sys/gmon.h>
45 #include <sys/imgact_aout.h>
46 #include <sys/imgact_elf.h>
47 #include <sys/mman.h>
48 #include <sys/pmc.h>
49 #include <sys/queue.h>
50 #include <sys/socket.h>
51 #include <sys/stat.h>
52 #include <sys/wait.h>
53 
54 #include <netinet/in.h>
55 
56 #include <assert.h>
57 #include <curses.h>
58 #include <err.h>
59 #include <errno.h>
60 #include <fcntl.h>
61 #include <gelf.h>
62 #include <libgen.h>
63 #include <limits.h>
64 #include <netdb.h>
65 #include <pmc.h>
66 #include <pmclog.h>
67 #include <sysexits.h>
68 #include <stdint.h>
69 #include <stdio.h>
70 #include <stdlib.h>
71 #include <string.h>
72 #include <unistd.h>
73 
74 #include "pmcstat.h"
75 #include "pmcstat_log.h"
76 #include "pmcpl_callgraph.h"
77 #include "pmcpl_gprof.h"
78 
79 typedef	uint64_t	WIDEHISTCOUNTER;
80 
81 #define	min(A,B)		((A) < (B) ? (A) : (B))
82 #define	max(A,B)		((A) > (B) ? (A) : (B))
83 
84 #define	WIDEHISTCOUNTER_MAX		UINT64_MAX
85 #define	HISTCOUNTER_MAX			USHRT_MAX
86 #define	WIDEHISTCOUNTER_GMONTYPE	((int) 64)
87 #define	HISTCOUNTER_GMONTYPE		((int) 0)
88 static int hc_sz=0;
89 
90 /*
91  * struct pmcstat_gmonfile tracks a given 'gmon.out' file.  These
92  * files are mmap()'ed in as needed.
93  */
94 
95 struct pmcstat_gmonfile {
96 	LIST_ENTRY(pmcstat_gmonfile)	pgf_next; /* list of entries */
97 	int		pgf_overflow;	/* whether a count overflowed */
98 	pmc_id_t	pgf_pmcid;	/* id of the associated pmc */
99 	size_t		pgf_nbuckets;	/* #buckets in this gmon.out */
100 	unsigned int	pgf_nsamples;	/* #samples in this gmon.out */
101 	pmcstat_interned_string pgf_name;	/* pathname of gmon.out file */
102 	size_t		pgf_ndatabytes;	/* number of bytes mapped */
103 	void		*pgf_gmondata;	/* pointer to mmap'ed data */
104 	FILE		*pgf_file;	/* used when writing gmon arcs */
105 };
106 
107 /*
108  * Prototypes
109  */
110 
111 static void	pmcstat_gmon_create_file(struct pmcstat_gmonfile *_pgf,
112     struct pmcstat_image *_image);
113 static pmcstat_interned_string pmcstat_gmon_create_name(const char *_sd,
114     struct pmcstat_image *_img, pmc_id_t _pmcid);
115 static void	pmcstat_gmon_map_file(struct pmcstat_gmonfile *_pgf);
116 static void	pmcstat_gmon_unmap_file(struct pmcstat_gmonfile *_pgf);
117 
118 static struct pmcstat_gmonfile *pmcstat_image_find_gmonfile(struct
119     pmcstat_image *_i, pmc_id_t _id);
120 
121 /*
122  * Create a gmon.out file and size it.
123  */
124 
125 static void
126 pmcstat_gmon_create_file(struct pmcstat_gmonfile *pgf,
127     struct pmcstat_image *image)
128 {
129 	int fd;
130 	size_t count;
131 	struct gmonhdr gm;
132 	const char *pathname;
133 	char buffer[DEFAULT_BUFFER_SIZE];
134 
135 	pathname = pmcstat_string_unintern(pgf->pgf_name);
136 	if ((fd = open(pathname, O_RDWR|O_NOFOLLOW|O_CREAT,
137 		 S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH)) < 0)
138 		err(EX_OSERR, "ERROR: Cannot open \"%s\"", pathname);
139 
140 	gm.lpc = image->pi_start;
141 	gm.hpc = image->pi_end;
142 	gm.ncnt = (pgf->pgf_nbuckets * hc_sz) + sizeof(struct gmonhdr);
143 	gm.version = GMONVERSION;
144 	gm.profrate = 0;		/* use ticks */
145 	if (args.pa_flags & FLAG_DO_WIDE_GPROF_HC)
146 		gm.histcounter_type = WIDEHISTCOUNTER_GMONTYPE;
147 	else
148 		gm.histcounter_type = HISTCOUNTER_GMONTYPE;
149 	gm.spare[0] = gm.spare[1] = 0;
150 
151 	/* Write out the gmon header */
152 	if (write(fd, &gm, sizeof(gm)) < 0)
153 		goto error;
154 
155 	/* Zero fill the samples[] array */
156 	(void) memset(buffer, 0, sizeof(buffer));
157 
158 	count = pgf->pgf_ndatabytes - sizeof(struct gmonhdr);
159 	while (count > sizeof(buffer)) {
160 		if (write(fd, &buffer, sizeof(buffer)) < 0)
161 			goto error;
162 		count -= sizeof(buffer);
163 	}
164 
165 	if (write(fd, &buffer, count) < 0)
166 		goto error;
167 
168 	(void) close(fd);
169 
170 	return;
171 
172  error:
173 	err(EX_OSERR, "ERROR: Cannot write \"%s\"", pathname);
174 }
175 
176 /*
177  * Determine the full pathname of a gmon.out file for a given
178  * (image,pmcid) combination.  Return the interned string.
179  */
180 
181 pmcstat_interned_string
182 pmcstat_gmon_create_name(const char *samplesdir, struct pmcstat_image *image,
183     pmc_id_t pmcid)
184 {
185 	const char *pmcname;
186 	char fullpath[PATH_MAX];
187 
188 	pmcname = pmcstat_pmcid_to_name(pmcid);
189 	if (!pmcname)
190 		err(EX_SOFTWARE, "ERROR: cannot find pmcid");
191 
192 	(void) snprintf(fullpath, sizeof(fullpath),
193 	    "%s/%s/%s", samplesdir, pmcname,
194 	    pmcstat_string_unintern(image->pi_samplename));
195 
196 	return (pmcstat_string_intern(fullpath));
197 }
198 
199 
200 /*
201  * Mmap in a gmon.out file for processing.
202  */
203 
204 static void
205 pmcstat_gmon_map_file(struct pmcstat_gmonfile *pgf)
206 {
207 	int fd;
208 	const char *pathname;
209 
210 	pathname = pmcstat_string_unintern(pgf->pgf_name);
211 
212 	/* the gmon.out file must already exist */
213 	if ((fd = open(pathname, O_RDWR | O_NOFOLLOW, 0)) < 0)
214 		err(EX_OSERR, "ERROR: cannot open \"%s\"", pathname);
215 
216 	pgf->pgf_gmondata = mmap(NULL, pgf->pgf_ndatabytes,
217 	    PROT_READ|PROT_WRITE, MAP_NOSYNC|MAP_SHARED, fd, 0);
218 
219 	if (pgf->pgf_gmondata == MAP_FAILED)
220 		err(EX_OSERR, "ERROR: cannot map \"%s\"", pathname);
221 
222 	(void) close(fd);
223 }
224 
225 /*
226  * Unmap a gmon.out file after sync'ing its data to disk.
227  */
228 
229 static void
230 pmcstat_gmon_unmap_file(struct pmcstat_gmonfile *pgf)
231 {
232 	(void) msync(pgf->pgf_gmondata, pgf->pgf_ndatabytes,
233 	    MS_SYNC);
234 	(void) munmap(pgf->pgf_gmondata, pgf->pgf_ndatabytes);
235 	pgf->pgf_gmondata = NULL;
236 }
237 
238 static void
239 pmcstat_gmon_append_arc(struct pmcstat_image *image, pmc_id_t pmcid,
240     uintptr_t rawfrom, uintptr_t rawto, uint32_t count)
241 {
242 	struct rawarc arc;	/* from <sys/gmon.h> */
243 	const char *pathname;
244 	struct pmcstat_gmonfile *pgf;
245 
246 	if ((pgf = pmcstat_image_find_gmonfile(image, pmcid)) == NULL)
247 		return;
248 
249 	if (pgf->pgf_file == NULL) {
250 		pathname = pmcstat_string_unintern(pgf->pgf_name);
251 		if ((pgf->pgf_file = fopen(pathname, "a")) == NULL)
252 			return;
253 	}
254 
255 	arc.raw_frompc = rawfrom + image->pi_vaddr;
256 	arc.raw_selfpc = rawto + image->pi_vaddr;
257 	arc.raw_count = count;
258 
259 	(void) fwrite(&arc, sizeof(arc), 1, pgf->pgf_file);
260 
261 }
262 
263 static struct pmcstat_gmonfile *
264 pmcstat_image_find_gmonfile(struct pmcstat_image *image, pmc_id_t pmcid)
265 {
266 	struct pmcstat_gmonfile *pgf;
267 	LIST_FOREACH(pgf, &image->pi_gmlist, pgf_next)
268 	    if (pgf->pgf_pmcid == pmcid)
269 		    return (pgf);
270 	return (NULL);
271 }
272 
273 static void
274 pmcstat_cgnode_do_gmon_arcs(struct pmcstat_cgnode *cg, pmc_id_t pmcid)
275 {
276 	struct pmcstat_cgnode *cgc;
277 
278 	/*
279 	 * Look for child nodes that belong to the same image.
280 	 */
281 
282 	LIST_FOREACH(cgc, &cg->pcg_children, pcg_sibling) {
283 		if (cgc->pcg_image == cg->pcg_image)
284 			pmcstat_gmon_append_arc(cg->pcg_image, pmcid,
285 			    cgc->pcg_func, cg->pcg_func, cgc->pcg_count);
286 		if (cgc->pcg_nchildren > 0)
287 			pmcstat_cgnode_do_gmon_arcs(cgc, pmcid);
288 	}
289 }
290 
291 static void
292 pmcstat_callgraph_do_gmon_arcs_for_pmcid(pmc_id_t pmcid)
293 {
294 	int n;
295 	struct pmcstat_cgnode_hash *pch;
296 
297 	for (n = 0; n < PMCSTAT_NHASH; n++)
298 		LIST_FOREACH(pch, &pmcstat_cgnode_hash[n], pch_next)
299 			if (pch->pch_pmcid == pmcid &&
300 			    pch->pch_cgnode->pcg_nchildren > 1)
301 				pmcstat_cgnode_do_gmon_arcs(pch->pch_cgnode,
302 				    pmcid);
303 }
304 
305 
306 static void
307 pmcstat_callgraph_do_gmon_arcs(void)
308 {
309 	struct pmcstat_pmcrecord *pmcr;
310 
311 	LIST_FOREACH(pmcr, &pmcstat_pmcs, pr_next)
312 		pmcstat_callgraph_do_gmon_arcs_for_pmcid(pmcr->pr_pmcid);
313 }
314 
315 void
316 pmcpl_gmon_initimage(struct pmcstat_image *pi)
317 {
318 	const char *execpath;
319 	int count, nlen;
320 	char *sn, *snbuf;
321 	char name[NAME_MAX];
322 
323 	/*
324 	 * Look for a suitable name for the sample files associated
325 	 * with this image: if `basename(path)`+".gmon" is available,
326 	 * we use that, otherwise we try iterating through
327 	 * `basename(path)`+ "~" + NNN + ".gmon" till we get a free
328 	 * entry.
329 	 */
330 	execpath = pmcstat_string_unintern(pi->pi_execpath);
331 	if ((snbuf = strdup(execpath)) == NULL)
332 		err(EX_OSERR, "ERROR: Cannot copy \"%s\"", execpath);
333 	if ((sn = basename(snbuf)) == NULL)
334 		err(EX_OSERR, "ERROR: Cannot process \"%s\"", execpath);
335 
336 	nlen = strlen(sn);
337 	nlen = min(nlen, (int) (sizeof(name) - sizeof(".gmon")));
338 
339 	snprintf(name, sizeof(name), "%.*s.gmon", nlen, sn);
340 
341 	/* try use the unabridged name first */
342 	if (pmcstat_string_lookup(name) == NULL)
343 		pi->pi_samplename = pmcstat_string_intern(name);
344 	else {
345 		/*
346 		 * Otherwise use a prefix from the original name and
347 		 * up to 3 digits.
348 		 */
349 		nlen = strlen(sn);
350 		nlen = min(nlen, (int) (sizeof(name)-sizeof("~NNN.gmon")));
351 		count = 0;
352 		do {
353 			if (++count > 999)
354 				errx(EX_CANTCREAT,
355 				    "ERROR: cannot create a gmon file for"
356 				    " \"%s\"", name);
357 			snprintf(name, sizeof(name), "%.*s~%3.3d.gmon",
358 			    nlen, sn, count);
359 			if (pmcstat_string_lookup(name) == NULL) {
360 				pi->pi_samplename =
361 				    pmcstat_string_intern(name);
362 				count = 0;
363 			}
364 		} while (count > 0);
365 	}
366 	free(snbuf);
367 
368 	LIST_INIT(&pi->pi_gmlist);
369 }
370 
371 void
372 pmcpl_gmon_shutdownimage(struct pmcstat_image *pi)
373 {
374 	struct pmcstat_gmonfile *pgf, *pgftmp;
375 
376 	LIST_FOREACH_SAFE(pgf, &pi->pi_gmlist, pgf_next, pgftmp) {
377 		if (pgf->pgf_file)
378 			(void) fclose(pgf->pgf_file);
379 		LIST_REMOVE(pgf, pgf_next);
380 		free(pgf);
381 	}
382 }
383 
384 void
385 pmcpl_gmon_newpmc(pmcstat_interned_string ps, struct pmcstat_pmcrecord *pr)
386 {
387 	struct stat st;
388 	char fullpath[PATH_MAX];
389 
390 	(void) pr;
391 
392 	/*
393 	 * Create the appropriate directory to hold gmon.out files.
394 	 */
395 
396 	(void) snprintf(fullpath, sizeof(fullpath), "%s/%s", args.pa_samplesdir,
397 	    pmcstat_string_unintern(ps));
398 
399 	/* If the path name exists, it should be a directory */
400 	if (stat(fullpath, &st) == 0 && S_ISDIR(st.st_mode))
401 		return;
402 
403 	if (mkdir(fullpath, S_IRWXU|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH) < 0)
404 		err(EX_OSERR, "ERROR: Cannot create directory \"%s\"",
405 		    fullpath);
406 }
407 
408 /*
409  * Increment the bucket in the gmon.out file corresponding to 'pmcid'
410  * and 'pc'.
411  */
412 
413 void
414 pmcpl_gmon_process(struct pmcstat_process *pp, struct pmcstat_pmcrecord *pmcr,
415     uint32_t nsamples, uintfptr_t *cc, int usermode, uint32_t cpu)
416 {
417 	struct pmcstat_pcmap *map;
418 	struct pmcstat_image *image;
419 	struct pmcstat_gmonfile *pgf;
420 	uintfptr_t bucket;
421 	HISTCOUNTER *hc;
422 	WIDEHISTCOUNTER *whc;
423 	pmc_id_t pmcid;
424 
425 	(void) nsamples; (void) usermode; (void) cpu;
426 
427 	map = pmcstat_process_find_map(usermode ? pp : pmcstat_kernproc, cc[0]);
428 	if (map == NULL) {
429 		/* Unknown offset. */
430 		pmcstat_stats.ps_samples_unknown_offset++;
431 		return;
432 	}
433 
434 	assert(cc[0] >= map->ppm_lowpc && cc[0] < map->ppm_highpc);
435 
436 	image = map->ppm_image;
437 	pmcid = pmcr->pr_pmcid;
438 
439 	/*
440 	 * If this is the first time we are seeing a sample for
441 	 * this executable image, try determine its parameters.
442 	 */
443 	if (image->pi_type == PMCSTAT_IMAGE_UNKNOWN)
444 		pmcstat_image_determine_type(image, &args);
445 
446 	assert(image->pi_type != PMCSTAT_IMAGE_UNKNOWN);
447 
448 	/* Ignore samples in images that we know nothing about. */
449 	if (image->pi_type == PMCSTAT_IMAGE_INDETERMINABLE) {
450 		pmcstat_stats.ps_samples_indeterminable++;
451 		return;
452 	}
453 
454 	/*
455 	 * Find the gmon file corresponding to 'pmcid', creating it if
456 	 * needed.
457 	 */
458 	pgf = pmcstat_image_find_gmonfile(image, pmcid);
459 	if (pgf == NULL) {
460 		if (hc_sz == 0) {
461 			/* Determine the correct histcounter size. */
462 			if (args.pa_flags & FLAG_DO_WIDE_GPROF_HC)
463 				hc_sz = sizeof(WIDEHISTCOUNTER);
464 			else
465 				hc_sz = sizeof(HISTCOUNTER);
466 		}
467 
468 		if ((pgf = calloc(1, sizeof(*pgf))) == NULL)
469 			err(EX_OSERR, "ERROR:");
470 
471 		pgf->pgf_gmondata = NULL;	/* mark as unmapped */
472 		pgf->pgf_name = pmcstat_gmon_create_name(args.pa_samplesdir,
473 		    image, pmcid);
474 		pgf->pgf_pmcid = pmcid;
475 		assert(image->pi_end > image->pi_start);
476 		pgf->pgf_nbuckets = howmany(image->pi_end - image->pi_start,
477 		    FUNCTION_ALIGNMENT);	/* see <machine/profile.h> */
478 		pgf->pgf_ndatabytes = sizeof(struct gmonhdr) +
479 		    pgf->pgf_nbuckets * hc_sz;
480 		pgf->pgf_nsamples = 0;
481 		pgf->pgf_file = NULL;
482 
483 		pmcstat_gmon_create_file(pgf, image);
484 
485 		LIST_INSERT_HEAD(&image->pi_gmlist, pgf, pgf_next);
486 	}
487 
488 	/*
489 	 * Map the gmon file in if needed.  It may have been mapped
490 	 * out under memory pressure.
491 	 */
492 	if (pgf->pgf_gmondata == NULL)
493 		pmcstat_gmon_map_file(pgf);
494 
495 	assert(pgf->pgf_gmondata != NULL);
496 
497 	/*
498 	 *
499 	 */
500 
501 	bucket = (cc[0] - map->ppm_lowpc) / FUNCTION_ALIGNMENT;
502 
503 	assert(bucket < pgf->pgf_nbuckets);
504 
505 	if (args.pa_flags & FLAG_DO_WIDE_GPROF_HC) {
506 		whc = (WIDEHISTCOUNTER *) ((uintptr_t) pgf->pgf_gmondata +
507 		    sizeof(struct gmonhdr));
508 
509 		/* saturating add */
510 		if (whc[bucket] < WIDEHISTCOUNTER_MAX)
511 			whc[bucket]++;
512 		else /* mark that an overflow occurred */
513 			pgf->pgf_overflow = 1;
514 	} else {
515 		hc = (HISTCOUNTER *) ((uintptr_t) pgf->pgf_gmondata +
516 		    sizeof(struct gmonhdr));
517 
518 		/* saturating add */
519 		if (hc[bucket] < HISTCOUNTER_MAX)
520 			hc[bucket]++;
521 		else /* mark that an overflow occurred */
522 			pgf->pgf_overflow = 1;
523 	}
524 
525 	pgf->pgf_nsamples++;
526 }
527 
528 /*
529  * Shutdown module.
530  */
531 
532 void
533 pmcpl_gmon_shutdown(FILE *mf)
534 {
535 	int i;
536 	struct pmcstat_gmonfile *pgf;
537 	struct pmcstat_image *pi;
538 
539 	/*
540 	 * Sync back all gprof flat profile data.
541 	 */
542 	for (i = 0; i < PMCSTAT_NHASH; i++) {
543 		LIST_FOREACH(pi, &pmcstat_image_hash[i], pi_next) {
544 			if (mf)
545 				(void) fprintf(mf, " \"%s\" => \"%s\"",
546 				    pmcstat_string_unintern(pi->pi_execpath),
547 				    pmcstat_string_unintern(
548 				    pi->pi_samplename));
549 
550 			/* flush gmon.out data to disk */
551 			LIST_FOREACH(pgf, &pi->pi_gmlist, pgf_next) {
552 				pmcstat_gmon_unmap_file(pgf);
553 				if (mf)
554 					(void) fprintf(mf, " %s/%d",
555 					    pmcstat_pmcid_to_name(
556 					    pgf->pgf_pmcid),
557 					    pgf->pgf_nsamples);
558 				if (pgf->pgf_overflow && args.pa_verbosity >= 1)
559 					warnx(
560 "WARNING: profile \"%s\" overflowed.",
561 					    pmcstat_string_unintern(
562 					        pgf->pgf_name));
563 			}
564 
565 			if (mf)
566 				(void) fprintf(mf, "\n");
567 		}
568 	}
569 
570 	/*
571 	 * Compute arcs and add these to the gprof files.
572 	 */
573 	if (args.pa_flags & FLAG_DO_GPROF && args.pa_graphdepth > 1)
574 		pmcstat_callgraph_do_gmon_arcs();
575 }
576