xref: /freebsd/usr.sbin/pmcstat/pmcpl_gprof.c (revision 8d20be1e22095c27faf8fe8b2f0d089739cc742e) 
1 /*-
2  * Copyright (c) 2005-2007, Joseph Koshy
3  * Copyright (c) 2007 The FreeBSD Foundation
4  * Copyright (c) 2009, Fabien Thomas
5  * All rights reserved.
6  *
7  * Portions of this software were developed by A. Joseph Koshy under
8  * sponsorship from the FreeBSD Foundation and Google, Inc.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 /*
33  * Transform a hwpmc(4) log into human readable form, and into
34  * gprof(1) compatible profiles.
35  */
36 
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
39 
40 #include <sys/param.h>
41 #include <sys/endian.h>
42 #include <sys/gmon.h>
43 #include <sys/imgact_aout.h>
44 #include <sys/imgact_elf.h>
45 #include <sys/mman.h>
46 #include <sys/pmc.h>
47 #include <sys/queue.h>
48 #include <sys/socket.h>
49 #include <sys/stat.h>
50 #include <sys/wait.h>
51 
52 #include <netinet/in.h>
53 
54 #include <assert.h>
55 #include <curses.h>
56 #include <err.h>
57 #include <errno.h>
58 #include <fcntl.h>
59 #include <gelf.h>
60 #include <libgen.h>
61 #include <limits.h>
62 #include <netdb.h>
63 #include <pmc.h>
64 #include <pmclog.h>
65 #include <sysexits.h>
66 #include <stdint.h>
67 #include <stdio.h>
68 #include <stdlib.h>
69 #include <string.h>
70 #include <unistd.h>
71 
72 #include "pmcstat.h"
73 #include "pmcstat_log.h"
74 #include "pmcpl_callgraph.h"
75 #include "pmcpl_gprof.h"
76 
77 /*
78  * struct pmcstat_gmonfile tracks a given 'gmon.out' file.  These
79  * files are mmap()'ed in as needed.
80  */
81 
82 struct pmcstat_gmonfile {
83 	LIST_ENTRY(pmcstat_gmonfile)	pgf_next; /* list of entries */
84 	int		pgf_overflow;	/* whether a count overflowed */
85 	pmc_id_t	pgf_pmcid;	/* id of the associated pmc */
86 	size_t		pgf_nbuckets;	/* #buckets in this gmon.out */
87 	unsigned int	pgf_nsamples;	/* #samples in this gmon.out */
88 	pmcstat_interned_string pgf_name;	/* pathname of gmon.out file */
89 	size_t		pgf_ndatabytes;	/* number of bytes mapped */
90 	void		*pgf_gmondata;	/* pointer to mmap'ed data */
91 	FILE		*pgf_file;	/* used when writing gmon arcs */
92 };
93 
94 /*
95  * Prototypes
96  */
97 
98 static void	pmcstat_gmon_create_file(struct pmcstat_gmonfile *_pgf,
99     struct pmcstat_image *_image);
100 static pmcstat_interned_string pmcstat_gmon_create_name(const char *_sd,
101     struct pmcstat_image *_img, pmc_id_t _pmcid);
102 static void	pmcstat_gmon_map_file(struct pmcstat_gmonfile *_pgf);
103 static void	pmcstat_gmon_unmap_file(struct pmcstat_gmonfile *_pgf);
104 
105 static struct pmcstat_gmonfile *pmcstat_image_find_gmonfile(struct
106     pmcstat_image *_i, pmc_id_t _id);
107 
108 /*
109  * Create a gmon.out file and size it.
110  */
111 
112 static void
113 pmcstat_gmon_create_file(struct pmcstat_gmonfile *pgf,
114     struct pmcstat_image *image)
115 {
116 	int fd;
117 	size_t count;
118 	struct gmonhdr gm;
119 	const char *pathname;
120 	char buffer[DEFAULT_BUFFER_SIZE];
121 
122 	pathname = pmcstat_string_unintern(pgf->pgf_name);
123 	if ((fd = open(pathname, O_RDWR|O_NOFOLLOW|O_CREAT,
124 		 S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH)) < 0)
125 		err(EX_OSERR, "ERROR: Cannot open \"%s\"", pathname);
126 
127 	gm.lpc = image->pi_start;
128 	gm.hpc = image->pi_end;
129 	gm.ncnt = (pgf->pgf_nbuckets * sizeof(HISTCOUNTER)) +
130 	    sizeof(struct gmonhdr);
131 	gm.version = GMONVERSION;
132 	gm.profrate = 0;		/* use ticks */
133 	gm.histcounter_type = 0;	/* compatibility with moncontrol() */
134 	gm.spare[0] = gm.spare[1] = 0;
135 
136 	/* Write out the gmon header */
137 	if (write(fd, &gm, sizeof(gm)) < 0)
138 		goto error;
139 
140 	/* Zero fill the samples[] array */
141 	(void) memset(buffer, 0, sizeof(buffer));
142 
143 	count = pgf->pgf_ndatabytes - sizeof(struct gmonhdr);
144 	while (count > sizeof(buffer)) {
145 		if (write(fd, &buffer, sizeof(buffer)) < 0)
146 			goto error;
147 		count -= sizeof(buffer);
148 	}
149 
150 	if (write(fd, &buffer, count) < 0)
151 		goto error;
152 
153 	(void) close(fd);
154 
155 	return;
156 
157  error:
158 	err(EX_OSERR, "ERROR: Cannot write \"%s\"", pathname);
159 }
160 
161 /*
162  * Determine the full pathname of a gmon.out file for a given
163  * (image,pmcid) combination.  Return the interned string.
164  */
165 
166 pmcstat_interned_string
167 pmcstat_gmon_create_name(const char *samplesdir, struct pmcstat_image *image,
168     pmc_id_t pmcid)
169 {
170 	const char *pmcname;
171 	char fullpath[PATH_MAX];
172 
173 	pmcname = pmcstat_pmcid_to_name(pmcid);
174 	if (!pmcname)
175 		err(EX_SOFTWARE, "ERROR: cannot find pmcid");
176 
177 	(void) snprintf(fullpath, sizeof(fullpath),
178 	    "%s/%s/%s", samplesdir, pmcname,
179 	    pmcstat_string_unintern(image->pi_samplename));
180 
181 	return (pmcstat_string_intern(fullpath));
182 }
183 
184 
185 /*
186  * Mmap in a gmon.out file for processing.
187  */
188 
189 static void
190 pmcstat_gmon_map_file(struct pmcstat_gmonfile *pgf)
191 {
192 	int fd;
193 	const char *pathname;
194 
195 	pathname = pmcstat_string_unintern(pgf->pgf_name);
196 
197 	/* the gmon.out file must already exist */
198 	if ((fd = open(pathname, O_RDWR | O_NOFOLLOW, 0)) < 0)
199 		err(EX_OSERR, "ERROR: cannot open \"%s\"", pathname);
200 
201 	pgf->pgf_gmondata = mmap(NULL, pgf->pgf_ndatabytes,
202 	    PROT_READ|PROT_WRITE, MAP_NOSYNC|MAP_SHARED, fd, 0);
203 
204 	if (pgf->pgf_gmondata == MAP_FAILED)
205 		err(EX_OSERR, "ERROR: cannot map \"%s\"", pathname);
206 
207 	(void) close(fd);
208 }
209 
210 /*
211  * Unmap a gmon.out file after sync'ing its data to disk.
212  */
213 
214 static void
215 pmcstat_gmon_unmap_file(struct pmcstat_gmonfile *pgf)
216 {
217 	(void) msync(pgf->pgf_gmondata, pgf->pgf_ndatabytes,
218 	    MS_SYNC);
219 	(void) munmap(pgf->pgf_gmondata, pgf->pgf_ndatabytes);
220 	pgf->pgf_gmondata = NULL;
221 }
222 
223 static void
224 pmcstat_gmon_append_arc(struct pmcstat_image *image, pmc_id_t pmcid,
225     uintptr_t rawfrom, uintptr_t rawto, uint32_t count)
226 {
227 	struct rawarc arc;	/* from <sys/gmon.h> */
228 	const char *pathname;
229 	struct pmcstat_gmonfile *pgf;
230 
231 	if ((pgf = pmcstat_image_find_gmonfile(image, pmcid)) == NULL)
232 		return;
233 
234 	if (pgf->pgf_file == NULL) {
235 		pathname = pmcstat_string_unintern(pgf->pgf_name);
236 		if ((pgf->pgf_file = fopen(pathname, "a")) == NULL)
237 			return;
238 	}
239 
240 	arc.raw_frompc = rawfrom + image->pi_vaddr;
241 	arc.raw_selfpc = rawto + image->pi_vaddr;
242 	arc.raw_count = count;
243 
244 	(void) fwrite(&arc, sizeof(arc), 1, pgf->pgf_file);
245 
246 }
247 
248 static struct pmcstat_gmonfile *
249 pmcstat_image_find_gmonfile(struct pmcstat_image *image, pmc_id_t pmcid)
250 {
251 	struct pmcstat_gmonfile *pgf;
252 	LIST_FOREACH(pgf, &image->pi_gmlist, pgf_next)
253 	    if (pgf->pgf_pmcid == pmcid)
254 		    return (pgf);
255 	return (NULL);
256 }
257 
258 static void
259 pmcstat_cgnode_do_gmon_arcs(struct pmcstat_cgnode *cg, pmc_id_t pmcid)
260 {
261 	struct pmcstat_cgnode *cgc;
262 
263 	/*
264 	 * Look for child nodes that belong to the same image.
265 	 */
266 
267 	LIST_FOREACH(cgc, &cg->pcg_children, pcg_sibling) {
268 		if (cgc->pcg_image == cg->pcg_image)
269 			pmcstat_gmon_append_arc(cg->pcg_image, pmcid,
270 			    cgc->pcg_func, cg->pcg_func, cgc->pcg_count);
271 		if (cgc->pcg_nchildren > 0)
272 			pmcstat_cgnode_do_gmon_arcs(cgc, pmcid);
273 	}
274 }
275 
276 static void
277 pmcstat_callgraph_do_gmon_arcs_for_pmcid(pmc_id_t pmcid)
278 {
279 	int n;
280 	struct pmcstat_cgnode_hash *pch;
281 
282 	for (n = 0; n < PMCSTAT_NHASH; n++)
283 		LIST_FOREACH(pch, &pmcstat_cgnode_hash[n], pch_next)
284 			if (pch->pch_pmcid == pmcid &&
285 			    pch->pch_cgnode->pcg_nchildren > 1)
286 				pmcstat_cgnode_do_gmon_arcs(pch->pch_cgnode,
287 				    pmcid);
288 }
289 
290 
291 static void
292 pmcstat_callgraph_do_gmon_arcs(void)
293 {
294 	struct pmcstat_pmcrecord *pmcr;
295 
296 	LIST_FOREACH(pmcr, &pmcstat_pmcs, pr_next)
297 		pmcstat_callgraph_do_gmon_arcs_for_pmcid(pmcr->pr_pmcid);
298 }
299 
300 void
301 pmcpl_gmon_initimage(struct pmcstat_image *pi)
302 {
303 	int count, nlen;
304 	char *sn;
305 	char name[NAME_MAX];
306 
307 	/*
308 	 * Look for a suitable name for the sample files associated
309 	 * with this image: if `basename(path)`+".gmon" is available,
310 	 * we use that, otherwise we try iterating through
311 	 * `basename(path)`+ "~" + NNN + ".gmon" till we get a free
312 	 * entry.
313 	 */
314 	if ((sn = basename(pmcstat_string_unintern(pi->pi_execpath))) == NULL)
315 		err(EX_OSERR, "ERROR: Cannot process \"%s\"",
316 		    pmcstat_string_unintern(pi->pi_execpath));
317 
318 	nlen = strlen(sn);
319 	nlen = min(nlen, (int) (sizeof(name) - sizeof(".gmon")));
320 
321 	snprintf(name, sizeof(name), "%.*s.gmon", nlen, sn);
322 
323 	/* try use the unabridged name first */
324 	if (pmcstat_string_lookup(name) == NULL)
325 		pi->pi_samplename = pmcstat_string_intern(name);
326 	else {
327 		/*
328 		 * Otherwise use a prefix from the original name and
329 		 * up to 3 digits.
330 		 */
331 		nlen = strlen(sn);
332 		nlen = min(nlen, (int) (sizeof(name)-sizeof("~NNN.gmon")));
333 		count = 0;
334 		do {
335 			if (++count > 999)
336 				errx(EX_CANTCREAT,
337 				    "ERROR: cannot create a gmon file for"
338 				    " \"%s\"", name);
339 			snprintf(name, sizeof(name), "%.*s~%3.3d.gmon",
340 			    nlen, sn, count);
341 			if (pmcstat_string_lookup(name) == NULL) {
342 				pi->pi_samplename =
343 				    pmcstat_string_intern(name);
344 				count = 0;
345 			}
346 		} while (count > 0);
347 	}
348 
349 	LIST_INIT(&pi->pi_gmlist);
350 }
351 
352 void
353 pmcpl_gmon_shutdownimage(struct pmcstat_image *pi)
354 {
355 	struct pmcstat_gmonfile *pgf, *pgftmp;
356 
357 	LIST_FOREACH_SAFE(pgf, &pi->pi_gmlist, pgf_next, pgftmp) {
358 		if (pgf->pgf_file)
359 			(void) fclose(pgf->pgf_file);
360 		LIST_REMOVE(pgf, pgf_next);
361 		free(pgf);
362 	}
363 }
364 
365 void
366 pmcpl_gmon_newpmc(pmcstat_interned_string ps, struct pmcstat_pmcrecord *pr)
367 {
368 	struct stat st;
369 	char fullpath[PATH_MAX];
370 
371 	(void) pr;
372 
373 	/*
374 	 * Create the appropriate directory to hold gmon.out files.
375 	 */
376 
377 	(void) snprintf(fullpath, sizeof(fullpath), "%s/%s", args.pa_samplesdir,
378 	    pmcstat_string_unintern(ps));
379 
380 	/* If the path name exists, it should be a directory */
381 	if (stat(fullpath, &st) == 0 && S_ISDIR(st.st_mode))
382 		return;
383 
384 	if (mkdir(fullpath, S_IRWXU|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH) < 0)
385 		err(EX_OSERR, "ERROR: Cannot create directory \"%s\"",
386 		    fullpath);
387 }
388 
389 /*
390  * Increment the bucket in the gmon.out file corresponding to 'pmcid'
391  * and 'pc'.
392  */
393 
394 void
395 pmcpl_gmon_process(struct pmcstat_process *pp, struct pmcstat_pmcrecord *pmcr,
396     uint32_t nsamples, uintfptr_t *cc, int usermode, uint32_t cpu)
397 {
398 	struct pmcstat_pcmap *map;
399 	struct pmcstat_image *image;
400 	struct pmcstat_gmonfile *pgf;
401 	uintfptr_t bucket;
402 	HISTCOUNTER *hc;
403 	pmc_id_t pmcid;
404 
405 	(void) nsamples; (void) usermode; (void) cpu;
406 
407 	map = pmcstat_process_find_map(usermode ? pp : pmcstat_kernproc, cc[0]);
408 	if (map == NULL) {
409 		/* Unknown offset. */
410 		pmcstat_stats.ps_samples_unknown_offset++;
411 		return;
412 	}
413 
414 	assert(cc[0] >= map->ppm_lowpc && cc[0] < map->ppm_highpc);
415 
416 	image = map->ppm_image;
417 	pmcid = pmcr->pr_pmcid;
418 
419 	/*
420 	 * If this is the first time we are seeing a sample for
421 	 * this executable image, try determine its parameters.
422 	 */
423 	if (image->pi_type == PMCSTAT_IMAGE_UNKNOWN)
424 		pmcstat_image_determine_type(image);
425 
426 	assert(image->pi_type != PMCSTAT_IMAGE_UNKNOWN);
427 
428 	/* Ignore samples in images that we know nothing about. */
429 	if (image->pi_type == PMCSTAT_IMAGE_INDETERMINABLE) {
430 		pmcstat_stats.ps_samples_indeterminable++;
431 		return;
432 	}
433 
434 	/*
435 	 * Find the gmon file corresponding to 'pmcid', creating it if
436 	 * needed.
437 	 */
438 	pgf = pmcstat_image_find_gmonfile(image, pmcid);
439 	if (pgf == NULL) {
440 		if ((pgf = calloc(1, sizeof(*pgf))) == NULL)
441 			err(EX_OSERR, "ERROR:");
442 
443 		pgf->pgf_gmondata = NULL;	/* mark as unmapped */
444 		pgf->pgf_name = pmcstat_gmon_create_name(args.pa_samplesdir,
445 		    image, pmcid);
446 		pgf->pgf_pmcid = pmcid;
447 		assert(image->pi_end > image->pi_start);
448 		pgf->pgf_nbuckets = (image->pi_end - image->pi_start) /
449 		    FUNCTION_ALIGNMENT;	/* see <machine/profile.h> */
450 		pgf->pgf_ndatabytes = sizeof(struct gmonhdr) +
451 		    pgf->pgf_nbuckets * sizeof(HISTCOUNTER);
452 		pgf->pgf_nsamples = 0;
453 		pgf->pgf_file = NULL;
454 
455 		pmcstat_gmon_create_file(pgf, image);
456 
457 		LIST_INSERT_HEAD(&image->pi_gmlist, pgf, pgf_next);
458 	}
459 
460 	/*
461 	 * Map the gmon file in if needed.  It may have been mapped
462 	 * out under memory pressure.
463 	 */
464 	if (pgf->pgf_gmondata == NULL)
465 		pmcstat_gmon_map_file(pgf);
466 
467 	assert(pgf->pgf_gmondata != NULL);
468 
469 	/*
470 	 *
471 	 */
472 
473 	bucket = (cc[0] - map->ppm_lowpc) / FUNCTION_ALIGNMENT;
474 
475 	assert(bucket < pgf->pgf_nbuckets);
476 
477 	hc = (HISTCOUNTER *) ((uintptr_t) pgf->pgf_gmondata +
478 	    sizeof(struct gmonhdr));
479 
480 	/* saturating add */
481 	if (hc[bucket] < 0xFFFFU)  /* XXX tie this to sizeof(HISTCOUNTER) */
482 		hc[bucket]++;
483 	else /* mark that an overflow occurred */
484 		pgf->pgf_overflow = 1;
485 
486 	pgf->pgf_nsamples++;
487 }
488 
489 /*
490  * Shutdown module.
491  */
492 
493 void
494 pmcpl_gmon_shutdown(FILE *mf)
495 {
496 	int i;
497 	struct pmcstat_gmonfile *pgf;
498 	struct pmcstat_image *pi;
499 
500 	/*
501 	 * Sync back all gprof flat profile data.
502 	 */
503 	for (i = 0; i < PMCSTAT_NHASH; i++) {
504 		LIST_FOREACH(pi, &pmcstat_image_hash[i], pi_next) {
505 			if (mf)
506 				(void) fprintf(mf, " \"%s\" => \"%s\"",
507 				    pmcstat_string_unintern(pi->pi_execpath),
508 				    pmcstat_string_unintern(
509 				    pi->pi_samplename));
510 
511 			/* flush gmon.out data to disk */
512 			LIST_FOREACH(pgf, &pi->pi_gmlist, pgf_next) {
513 				pmcstat_gmon_unmap_file(pgf);
514 				if (mf)
515 					(void) fprintf(mf, " %s/%d",
516 					    pmcstat_pmcid_to_name(
517 					    pgf->pgf_pmcid),
518 					    pgf->pgf_nsamples);
519 				if (pgf->pgf_overflow && args.pa_verbosity >= 1)
520 					warnx(
521 "WARNING: profile \"%s\" overflowed.",
522 					    pmcstat_string_unintern(
523 					        pgf->pgf_name));
524 			}
525 
526 			if (mf)
527 				(void) fprintf(mf, "\n");
528 		}
529 	}
530 
531 	/*
532 	 * Compute arcs and add these to the gprof files.
533 	 */
534 	if (args.pa_flags & FLAG_DO_GPROF && args.pa_graphdepth > 1)
535 		pmcstat_callgraph_do_gmon_arcs();
536 }
537