1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
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 #if defined(LIBC_SCCS) && !defined(lint)
33 static char sccsid[] = "@(#)gmon.c 8.1 (Berkeley) 6/4/93";
34 #endif
35 #include "namespace.h"
36 #include <sys/param.h>
37 #include <sys/time.h>
38 #include <sys/gmon.h>
39 #include <sys/mman.h>
40 #include <sys/sysctl.h>
41
42 #include <err.h>
43 #include <fcntl.h>
44 #include <inttypes.h>
45 #include <stdio.h>
46 #include <stdlib.h>
47 #include <string.h>
48 #include <unistd.h>
49 #include "un-namespace.h"
50
51 #include "libc_private.h"
52
53 struct gmonparam _gmonparam = { GMON_PROF_OFF };
54
55 static int s_scale;
56 /* See profil(2) where this is described (incorrectly). */
57 #define SCALE_SHIFT 16
58
59 #define ERR(s) _write(2, s, sizeof(s))
60
61 void moncontrol(int);
62 static int hertz(void);
63 void _mcleanup(void);
64
65 void
monstartup(u_long lowpc,u_long highpc)66 monstartup(u_long lowpc, u_long highpc)
67 {
68 int o;
69 char *cp;
70 struct gmonparam *p = &_gmonparam;
71
72 /*
73 * round lowpc and highpc to multiples of the density we're using
74 * so the rest of the scaling (here and in gprof) stays in ints.
75 */
76 p->lowpc = ROUNDDOWN(lowpc, HISTFRACTION * sizeof(HISTCOUNTER));
77 p->highpc = ROUNDUP(highpc, HISTFRACTION * sizeof(HISTCOUNTER));
78 p->textsize = p->highpc - p->lowpc;
79 p->kcountsize = p->textsize / HISTFRACTION;
80 p->hashfraction = HASHFRACTION;
81 p->fromssize = p->textsize / HASHFRACTION;
82 p->tolimit = p->textsize * ARCDENSITY / 100;
83 if (p->tolimit < MINARCS)
84 p->tolimit = MINARCS;
85 else if (p->tolimit > MAXARCS)
86 p->tolimit = MAXARCS;
87 p->tossize = p->tolimit * sizeof(struct tostruct);
88
89 cp = mmap(NULL, p->kcountsize + p->fromssize + p->tossize,
90 PROT_READ | PROT_WRITE, MAP_ANON, -1, 0);
91 if (cp == MAP_FAILED) {
92 ERR("monstartup: out of memory\n");
93 return;
94 }
95 #ifdef notdef
96 bzero(cp, p->kcountsize + p->fromssize + p->tossize);
97 #endif
98 p->tos = (struct tostruct *)cp;
99 cp += p->tossize;
100 p->kcount = (u_short *)cp;
101 cp += p->kcountsize;
102 p->froms = (u_short *)cp;
103
104 p->tos[0].link = 0;
105
106 o = p->highpc - p->lowpc;
107 s_scale = (p->kcountsize < o) ?
108 ((uintmax_t)p->kcountsize << SCALE_SHIFT) / o : (1 << SCALE_SHIFT);
109 moncontrol(1);
110 }
111
112 void
_mcleanup(void)113 _mcleanup(void)
114 {
115 int fd;
116 int fromindex;
117 int endfrom;
118 u_long frompc;
119 int toindex;
120 struct rawarc rawarc;
121 struct gmonparam *p = &_gmonparam;
122 struct gmonhdr gmonhdr, *hdr;
123 struct clockinfo clockinfo;
124 char outname[128];
125 int mib[2];
126 size_t size;
127 #ifdef DEBUG
128 int log, len;
129 char buf[200];
130 #endif
131
132 if (p->state == GMON_PROF_ERROR)
133 ERR("_mcleanup: tos overflow\n");
134
135 size = sizeof(clockinfo);
136 mib[0] = CTL_KERN;
137 mib[1] = KERN_CLOCKRATE;
138 if (sysctl(mib, 2, &clockinfo, &size, NULL, 0) < 0) {
139 /*
140 * Best guess
141 */
142 clockinfo.profhz = hertz();
143 } else if (clockinfo.profhz == 0) {
144 if (clockinfo.hz != 0)
145 clockinfo.profhz = clockinfo.hz;
146 else
147 clockinfo.profhz = hertz();
148 }
149
150 moncontrol(0);
151 if (getenv("PROFIL_USE_PID"))
152 snprintf(outname, sizeof(outname), "%s.%d.gmon",
153 _getprogname(), getpid());
154 else
155 snprintf(outname, sizeof(outname), "%s.gmon", _getprogname());
156
157 fd = _open(outname, O_CREAT|O_TRUNC|O_WRONLY|O_CLOEXEC, 0666);
158 if (fd < 0) {
159 _warn("_mcleanup: %s", outname);
160 return;
161 }
162 #ifdef DEBUG
163 log = _open("gmon.log", O_CREAT|O_TRUNC|O_WRONLY|O_CLOEXEC, 0664);
164 if (log < 0) {
165 _warn("_mcleanup: gmon.log");
166 return;
167 }
168 len = sprintf(buf, "[mcleanup1] kcount 0x%p ssiz %lu\n",
169 p->kcount, p->kcountsize);
170 _write(log, buf, len);
171 #endif
172 hdr = (struct gmonhdr *)&gmonhdr;
173 bzero(hdr, sizeof(*hdr));
174 hdr->lpc = p->lowpc;
175 hdr->hpc = p->highpc;
176 hdr->ncnt = p->kcountsize + sizeof(gmonhdr);
177 hdr->version = GMONVERSION;
178 hdr->profrate = clockinfo.profhz;
179 _write(fd, (char *)hdr, sizeof *hdr);
180 _write(fd, p->kcount, p->kcountsize);
181 endfrom = p->fromssize / sizeof(*p->froms);
182 for (fromindex = 0; fromindex < endfrom; fromindex++) {
183 if (p->froms[fromindex] == 0)
184 continue;
185
186 frompc = p->lowpc;
187 frompc += fromindex * p->hashfraction * sizeof(*p->froms);
188 for (toindex = p->froms[fromindex]; toindex != 0;
189 toindex = p->tos[toindex].link) {
190 #ifdef DEBUG
191 len = sprintf(buf,
192 "[mcleanup2] frompc 0x%lx selfpc 0x%lx count %lu\n" ,
193 frompc, p->tos[toindex].selfpc,
194 p->tos[toindex].count);
195 _write(log, buf, len);
196 #endif
197 rawarc.raw_frompc = frompc;
198 rawarc.raw_selfpc = p->tos[toindex].selfpc;
199 rawarc.raw_count = p->tos[toindex].count;
200 _write(fd, &rawarc, sizeof rawarc);
201 }
202 }
203 _close(fd);
204 }
205
206 /*
207 * Control profiling
208 * profiling is what mcount checks to see if
209 * all the data structures are ready.
210 */
211 void
moncontrol(int mode)212 moncontrol(int mode)
213 {
214 struct gmonparam *p = &_gmonparam;
215
216 if (mode) {
217 /* start */
218 profil((char *)p->kcount, p->kcountsize, p->lowpc, s_scale);
219 p->state = GMON_PROF_ON;
220 } else {
221 /* stop */
222 profil((char *)0, 0, 0, 0);
223 p->state = GMON_PROF_OFF;
224 }
225 }
226
227 /*
228 * discover the tick frequency of the machine
229 * if something goes wrong, we return 0, an impossible hertz.
230 */
231 static int
hertz(void)232 hertz(void)
233 {
234 struct itimerval tim;
235
236 tim.it_interval.tv_sec = 0;
237 tim.it_interval.tv_usec = 1;
238 tim.it_value.tv_sec = 0;
239 tim.it_value.tv_usec = 0;
240 setitimer(ITIMER_REAL, &tim, 0);
241 setitimer(ITIMER_REAL, 0, &tim);
242 if (tim.it_interval.tv_usec < 2)
243 return(0);
244 return (1000000 / tim.it_interval.tv_usec);
245 }
246