gmon.c revision 1.21 1 /* $NetBSD: gmon.c,v 1.21 2003/08/07 16:43:02 agc 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. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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 #include <sys/cdefs.h>
33 #if !defined(lint) && defined(LIBC_SCCS)
34 #if 0
35 static char sccsid[] = "@(#)gmon.c 8.1 (Berkeley) 6/4/93";
36 #else
37 __RCSID("$NetBSD: gmon.c,v 1.21 2003/08/07 16:43:02 agc Exp $");
38 #endif
39 #endif
40
41 #include "namespace.h"
42 #include <sys/param.h>
43 #include <sys/time.h>
44 #include <sys/gmon.h>
45 #include <sys/sysctl.h>
46
47 #include <stdio.h>
48 #include <stdlib.h>
49 #include <fcntl.h>
50 #include <limits.h>
51 #include <unistd.h>
52 #include <err.h>
53 #include "extern.h"
54
55 struct gmonparam _gmonparam = { GMON_PROF_OFF };
56
57 static u_int s_scale;
58 /* see profil(2) where this is describe (incorrectly) */
59 #define SCALE_1_TO_1 0x10000L
60
61 #define ERR(s) write(STDERR_FILENO, s, sizeof(s))
62
63 void moncontrol __P((int));
64 void monstartup __P((u_long, u_long));
65 void _mcleanup __P((void));
66 static int hertz __P((void));
67
68
69 void
70 monstartup(lowpc, highpc)
71 u_long lowpc;
72 u_long highpc;
73 {
74 u_long o;
75 char *cp;
76 struct gmonparam *p = &_gmonparam;
77
78 /*
79 * round lowpc and highpc to multiples of the density we're using
80 * so the rest of the scaling (here and in gprof) stays in ints.
81 */
82 p->lowpc = ROUNDDOWN(lowpc, HISTFRACTION * sizeof(HISTCOUNTER));
83 p->highpc = ROUNDUP(highpc, HISTFRACTION * sizeof(HISTCOUNTER));
84 p->textsize = p->highpc - p->lowpc;
85 p->kcountsize = p->textsize / HISTFRACTION;
86 p->hashfraction = HASHFRACTION;
87 p->fromssize = p->textsize / p->hashfraction;
88 p->tolimit = p->textsize * ARCDENSITY / 100;
89 if (p->tolimit < MINARCS)
90 p->tolimit = MINARCS;
91 else if (p->tolimit > MAXARCS)
92 p->tolimit = MAXARCS;
93 p->tossize = p->tolimit * sizeof(struct tostruct);
94
95 cp = sbrk((intptr_t)(p->kcountsize + p->fromssize + p->tossize));
96 if (cp == (char *)-1) {
97 ERR("monstartup: out of memory\n");
98 return;
99 }
100 #ifdef notdef
101 memset(cp, 0, p->kcountsize + p->fromssize + p->tossize);
102 #endif
103 p->tos = (struct tostruct *)(void *)cp;
104 cp += (size_t)p->tossize;
105 p->kcount = (u_short *)(void *)cp;
106 cp += (size_t)p->kcountsize;
107 p->froms = (u_short *)(void *)cp;
108
109 __minbrk = sbrk((intptr_t)0);
110 p->tos[0].link = 0;
111
112 o = p->highpc - p->lowpc;
113 if (p->kcountsize < o) {
114 #ifndef notdef
115 s_scale = ((float)p->kcountsize / o ) * SCALE_1_TO_1;
116 #else /* avoid floating point */
117 u_long quot = o / p->kcountsize;
118
119 if (quot >= 0x10000)
120 s_scale = 1;
121 else if (quot >= 0x100)
122 s_scale = 0x10000 / quot;
123 else if (o >= 0x800000)
124 s_scale = 0x1000000 / (o / (p->kcountsize >> 8));
125 else
126 s_scale = 0x1000000 / ((o << 8) / p->kcountsize);
127 #endif
128 } else
129 s_scale = SCALE_1_TO_1;
130
131 moncontrol(1);
132 }
133
134 void
135 _mcleanup()
136 {
137 int fd;
138 int fromindex;
139 int endfrom;
140 u_long frompc;
141 int toindex;
142 struct rawarc rawarc;
143 struct gmonparam *p = &_gmonparam;
144 struct gmonhdr gmonhdr, *hdr;
145 struct clockinfo clockinfo;
146 int mib[2];
147 size_t size;
148 char *profdir;
149 char *proffile;
150 char buf[PATH_MAX];
151 #ifdef DEBUG
152 int log, len;
153 char buf2[200];
154 #endif
155
156 /*
157 * We disallow writing to the profiling file, if we are a
158 * set{u,g}id program and our effective {u,g}id does not match
159 * our real one.
160 */
161 if (issetugid() && (geteuid() != getuid() || getegid() != getgid())) {
162 warnx("mcount: Profiling of set{u,g}id binaries is not"
163 " allowed");
164 return;
165 }
166
167 if (p->state == GMON_PROF_ERROR)
168 ERR("_mcleanup: tos overflow\n");
169
170 size = sizeof(clockinfo);
171 mib[0] = CTL_KERN;
172 mib[1] = KERN_CLOCKRATE;
173 if (sysctl(mib, 2, &clockinfo, &size, NULL, 0) < 0) {
174 /*
175 * Best guess
176 */
177 clockinfo.profhz = hertz();
178 } else if (clockinfo.profhz == 0) {
179 if (clockinfo.hz != 0)
180 clockinfo.profhz = clockinfo.hz;
181 else
182 clockinfo.profhz = hertz();
183 }
184
185 moncontrol(0);
186
187 if ((profdir = getenv("PROFDIR")) != NULL) {
188 /* If PROFDIR contains a null value, no profiling
189 output is produced */
190 if (*profdir == '\0')
191 return;
192
193 if (snprintf(buf, sizeof buf, "%s/%d.%s",
194 profdir, getpid(), getprogname()) >= sizeof buf) {
195 warnx("_mcleanup: internal buffer overflow, PROFDIR too long");
196 return;
197 }
198
199 proffile = buf;
200 } else {
201 proffile = "gmon.out";
202 }
203
204 fd = open(proffile , O_CREAT|O_TRUNC|O_WRONLY, 0666);
205 if (fd < 0) {
206 warn("mcount: Cannot open `%s'", proffile);
207 return;
208 }
209 #ifdef DEBUG
210 log = open("gmon.log", O_CREAT|O_TRUNC|O_WRONLY, 0664);
211 if (log < 0) {
212 warn("mcount: Cannot open `gmon.log'");
213 return;
214 }
215 len = snprintf(buf2, sizeof buf2, "[mcleanup1] kcount 0x%x ssiz %d\n",
216 p->kcount, p->kcountsize);
217 write(log, buf2, len);
218 #endif
219 hdr = (struct gmonhdr *)&gmonhdr;
220 hdr->lpc = p->lowpc;
221 hdr->hpc = p->highpc;
222 hdr->ncnt = (int)(p->kcountsize + sizeof(gmonhdr));
223 hdr->version = GMONVERSION;
224 hdr->profrate = clockinfo.profhz;
225 (void)write(fd, hdr, sizeof *hdr);
226 (void)write(fd, p->kcount, (size_t)p->kcountsize);
227 endfrom = (int)(p->fromssize / sizeof(*p->froms));
228 for (fromindex = 0; fromindex < endfrom; fromindex++) {
229 if (p->froms[fromindex] == 0)
230 continue;
231
232 frompc = p->lowpc;
233 frompc += fromindex * p->hashfraction * sizeof(*p->froms);
234 for (toindex = p->froms[fromindex]; toindex != 0;
235 toindex = p->tos[toindex].link) {
236 #ifdef DEBUG
237 len = snprintf(buf2, sizeof buf2,
238 "[mcleanup2] frompc 0x%x selfpc 0x%x count %d\n" ,
239 frompc, p->tos[toindex].selfpc,
240 p->tos[toindex].count);
241 write(log, buf2, len);
242 #endif
243 rawarc.raw_frompc = frompc;
244 rawarc.raw_selfpc = p->tos[toindex].selfpc;
245 rawarc.raw_count = p->tos[toindex].count;
246 write(fd, &rawarc, sizeof rawarc);
247 }
248 }
249 close(fd);
250 }
251
252 /*
253 * Control profiling
254 * profiling is what mcount checks to see if
255 * all the data structures are ready.
256 */
257 void
258 moncontrol(mode)
259 int mode;
260 {
261 struct gmonparam *p = &_gmonparam;
262
263 if (mode) {
264 /* start */
265 profil((char *)(void *)p->kcount, (size_t)p->kcountsize,
266 p->lowpc, s_scale);
267 p->state = GMON_PROF_ON;
268 } else {
269 /* stop */
270 profil(NULL, 0, (u_long)0, 0);
271 p->state = GMON_PROF_OFF;
272 }
273 }
274
275 /*
276 * discover the tick frequency of the machine
277 * if something goes wrong, we return 0, an impossible hertz.
278 */
279 static int
280 hertz()
281 {
282 struct itimerval tim;
283
284 tim.it_interval.tv_sec = 0;
285 tim.it_interval.tv_usec = 1;
286 tim.it_value.tv_sec = 0;
287 tim.it_value.tv_usec = 0;
288 setitimer(ITIMER_REAL, &tim, 0);
289 setitimer(ITIMER_REAL, 0, &tim);
290 if (tim.it_interval.tv_usec < 2)
291 return(0);
292 return (int)(1000000 / tim.it_interval.tv_usec);
293 }
294