gmon.c revision 1.17.2.1 1 /* $NetBSD: gmon.c,v 1.17.2.1 2002/06/21 18:18:13 nathanw Exp $ */
2
3 /*-
4 * Copyright (c) 1983, 1992, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. All advertising materials mentioning features or use of this software
16 * must display the following acknowledgement:
17 * This product includes software developed by the University of
18 * California, Berkeley and its contributors.
19 * 4. Neither the name of the University nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36 #include <sys/cdefs.h>
37 #if !defined(lint) && defined(LIBC_SCCS)
38 #if 0
39 static char sccsid[] = "@(#)gmon.c 8.1 (Berkeley) 6/4/93";
40 #else
41 __RCSID("$NetBSD: gmon.c,v 1.17.2.1 2002/06/21 18:18:13 nathanw Exp $");
42 #endif
43 #endif
44
45 #include "namespace.h"
46 #include <sys/param.h>
47 #include <sys/time.h>
48 #include <sys/gmon.h>
49 #include <sys/sysctl.h>
50
51 #include <stdio.h>
52 #include <stdlib.h>
53 #include <fcntl.h>
54 #include <limits.h>
55 #include <unistd.h>
56 #include <err.h>
57 #include "extern.h"
58
59 struct gmonparam _gmonparam = { GMON_PROF_OFF };
60
61 static u_int s_scale;
62 /* see profil(2) where this is describe (incorrectly) */
63 #define SCALE_1_TO_1 0x10000L
64
65 #define ERR(s) write(STDERR_FILENO, s, sizeof(s))
66
67 void moncontrol __P((int));
68 void monstartup __P((u_long, u_long));
69 void _mcleanup __P((void));
70 static int hertz __P((void));
71
72
73 void
74 monstartup(lowpc, highpc)
75 u_long lowpc;
76 u_long highpc;
77 {
78 long o;
79 char *cp;
80 struct gmonparam *p = &_gmonparam;
81
82 /*
83 * round lowpc and highpc to multiples of the density we're using
84 * so the rest of the scaling (here and in gprof) stays in ints.
85 */
86 p->lowpc = ROUNDDOWN(lowpc, HISTFRACTION * sizeof(HISTCOUNTER));
87 p->highpc = ROUNDUP(highpc, HISTFRACTION * sizeof(HISTCOUNTER));
88 p->textsize = p->highpc - p->lowpc;
89 p->kcountsize = p->textsize / HISTFRACTION;
90 p->hashfraction = HASHFRACTION;
91 p->fromssize = p->textsize / p->hashfraction;
92 p->tolimit = p->textsize * ARCDENSITY / 100;
93 if (p->tolimit < MINARCS)
94 p->tolimit = MINARCS;
95 else if (p->tolimit > MAXARCS)
96 p->tolimit = MAXARCS;
97 p->tossize = p->tolimit * sizeof(struct tostruct);
98
99 cp = sbrk((intptr_t)(p->kcountsize + p->fromssize + p->tossize));
100 if (cp == (char *)-1) {
101 ERR("monstartup: out of memory\n");
102 return;
103 }
104 #ifdef notdef
105 memset(cp, 0, p->kcountsize + p->fromssize + p->tossize);
106 #endif
107 p->tos = (struct tostruct *)(void *)cp;
108 cp += (size_t)p->tossize;
109 p->kcount = (u_short *)(void *)cp;
110 cp += (size_t)p->kcountsize;
111 p->froms = (u_short *)(void *)cp;
112
113 __minbrk = sbrk((intptr_t)0);
114 p->tos[0].link = 0;
115
116 o = p->highpc - p->lowpc;
117 if (p->kcountsize < o) {
118 #ifndef notdef
119 s_scale = ((float)p->kcountsize / o ) * SCALE_1_TO_1;
120 #else /* avoid floating point */
121 int quot = o / p->kcountsize;
122
123 if (quot >= 0x10000)
124 s_scale = 1;
125 else if (quot >= 0x100)
126 s_scale = 0x10000 / quot;
127 else if (o >= 0x800000)
128 s_scale = 0x1000000 / (o / (p->kcountsize >> 8));
129 else
130 s_scale = 0x1000000 / ((o << 8) / p->kcountsize);
131 #endif
132 } else
133 s_scale = SCALE_1_TO_1;
134
135 moncontrol(1);
136 }
137
138 void
139 _mcleanup()
140 {
141 int fd;
142 int fromindex;
143 int endfrom;
144 u_long frompc;
145 int toindex;
146 struct rawarc rawarc;
147 struct gmonparam *p = &_gmonparam;
148 struct gmonhdr gmonhdr, *hdr;
149 struct clockinfo clockinfo;
150 int mib[2];
151 size_t size;
152 char *profdir;
153 char *proffile;
154 char buf[PATH_MAX];
155 int len = sizeof(buf) - 1;
156 #ifdef DEBUG
157 int log, len;
158 char buf2[200];
159 #endif
160
161 /*
162 * We disallow writing to the profiling file, if we are a
163 * set{u,g}id program and our effective {u,g}id does not match
164 * our real one.
165 */
166 if (issetugid() && (geteuid() != getuid() || getegid() != getgid())) {
167 warnx("mcount: Profiling of set{u,g}id binaries is not"
168 " allowed");
169 return;
170 }
171
172 if (p->state == GMON_PROF_ERROR)
173 ERR("_mcleanup: tos overflow\n");
174
175 size = sizeof(clockinfo);
176 mib[0] = CTL_KERN;
177 mib[1] = KERN_CLOCKRATE;
178 if (sysctl(mib, 2, &clockinfo, &size, NULL, 0) < 0) {
179 /*
180 * Best guess
181 */
182 clockinfo.profhz = hertz();
183 } else if (clockinfo.profhz == 0) {
184 if (clockinfo.hz != 0)
185 clockinfo.profhz = clockinfo.hz;
186 else
187 clockinfo.profhz = hertz();
188 }
189
190 moncontrol(0);
191
192 if ((profdir = getenv("PROFDIR")) != NULL) {
193 const char *s;
194 char *t;
195 pid_t pid;
196 long divisor;
197
198 /* If PROFDIR contains a null value, no profiling
199 output is produced */
200 if (*profdir == '\0') {
201 return;
202 }
203
204 t = buf;
205 s = profdir;
206 while ((*t = *s) != '\0') {
207 if (len-- == 0) {
208 warnx("_mcleanup: internal buffer overflow, PROFDIR too long");
209 return;
210 }
211 t++;
212 s++;
213 }
214 *t++ = '/';
215
216 /*
217 * Copy and convert pid from a pid_t to a string. For
218 * best performance, divisor should be initialized to
219 * the largest power of 10 less than PID_MAX.
220 */
221 pid = getpid();
222 divisor=10000;
223 while (divisor > pid) divisor /= 10; /* skip leading zeros */
224 do {
225 *t++ = (char)((pid/divisor) + '0');
226 pid %= (pid_t)divisor;
227 } while (divisor /= 10);
228 *t++ = '.';
229
230 s = getprogname();
231 while ((*t++ = *s++) != '\0')
232 ;
233
234 proffile = buf;
235 } else {
236 proffile = "gmon.out";
237 }
238
239 fd = open(proffile , O_CREAT|O_TRUNC|O_WRONLY, 0666);
240 if (fd < 0) {
241 warn("mcount: Cannot open `%s'", proffile);
242 return;
243 }
244 #ifdef DEBUG
245 log = open("gmon.log", O_CREAT|O_TRUNC|O_WRONLY, 0664);
246 if (log < 0) {
247 warn("mcount: Cannot open `gmon.log'");
248 return;
249 }
250 len = snprintf(buf2, sizeof buf2, "[mcleanup1] kcount 0x%x ssiz %d\n",
251 p->kcount, p->kcountsize);
252 write(log, buf2, len);
253 #endif
254 hdr = (struct gmonhdr *)&gmonhdr;
255 hdr->lpc = p->lowpc;
256 hdr->hpc = p->highpc;
257 hdr->ncnt = (int)(p->kcountsize + sizeof(gmonhdr));
258 hdr->version = GMONVERSION;
259 hdr->profrate = clockinfo.profhz;
260 (void)write(fd, hdr, sizeof *hdr);
261 (void)write(fd, p->kcount, (size_t)p->kcountsize);
262 endfrom = (int)(p->fromssize / sizeof(*p->froms));
263 for (fromindex = 0; fromindex < endfrom; fromindex++) {
264 if (p->froms[fromindex] == 0)
265 continue;
266
267 frompc = p->lowpc;
268 frompc += fromindex * p->hashfraction * sizeof(*p->froms);
269 for (toindex = p->froms[fromindex]; toindex != 0;
270 toindex = p->tos[toindex].link) {
271 #ifdef DEBUG
272 len = snprintf(buf2, sizeof buf2,
273 "[mcleanup2] frompc 0x%x selfpc 0x%x count %d\n" ,
274 frompc, p->tos[toindex].selfpc,
275 p->tos[toindex].count);
276 write(log, buf2, len);
277 #endif
278 rawarc.raw_frompc = frompc;
279 rawarc.raw_selfpc = p->tos[toindex].selfpc;
280 rawarc.raw_count = p->tos[toindex].count;
281 write(fd, &rawarc, sizeof rawarc);
282 }
283 }
284 close(fd);
285 }
286
287 /*
288 * Control profiling
289 * profiling is what mcount checks to see if
290 * all the data structures are ready.
291 */
292 void
293 moncontrol(mode)
294 int mode;
295 {
296 struct gmonparam *p = &_gmonparam;
297
298 if (mode) {
299 /* start */
300 profil((char *)(void *)p->kcount, (size_t)p->kcountsize,
301 p->lowpc, s_scale);
302 p->state = GMON_PROF_ON;
303 } else {
304 /* stop */
305 profil(NULL, 0, (u_long)0, 0);
306 p->state = GMON_PROF_OFF;
307 }
308 }
309
310 /*
311 * discover the tick frequency of the machine
312 * if something goes wrong, we return 0, an impossible hertz.
313 */
314 static int
315 hertz()
316 {
317 struct itimerval tim;
318
319 tim.it_interval.tv_sec = 0;
320 tim.it_interval.tv_usec = 1;
321 tim.it_value.tv_sec = 0;
322 tim.it_value.tv_usec = 0;
323 setitimer(ITIMER_REAL, &tim, 0);
324 setitimer(ITIMER_REAL, 0, &tim);
325 if (tim.it_interval.tv_usec < 2)
326 return(0);
327 return (int)(1000000 / tim.it_interval.tv_usec);
328 }
329