1 /* $NetBSD: mcount.c,v 1.18 2024/02/23 13:32:28 christos Exp $ */
2
3 /*
4 * Copyright (c) 2003, 2004 Wasabi Systems, Inc.
5 * All rights reserved.
6 *
7 * Written by Nathan J. Williams for Wasabi Systems, Inc.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. All advertising materials mentioning features or use of this software
18 * must display the following acknowledgement:
19 * This product includes software developed for the NetBSD Project by
20 * Wasabi Systems, Inc.
21 * 4. The name of Wasabi Systems, Inc. may not be used to endorse
22 * or promote products derived from this software without specific prior
23 * written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
27 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
28 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL WASABI SYSTEMS, INC
29 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
30 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
33 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35 * POSSIBILITY OF SUCH DAMAGE.
36 */
37
38 /*-
39 * Copyright (c) 1983, 1992, 1993
40 * The Regents of the University of California. All rights reserved.
41 *
42 * Redistribution and use in source and binary forms, with or without
43 * modification, are permitted provided that the following conditions
44 * are met:
45 * 1. Redistributions of source code must retain the above copyright
46 * notice, this list of conditions and the following disclaimer.
47 * 2. Redistributions in binary form must reproduce the above copyright
48 * notice, this list of conditions and the following disclaimer in the
49 * documentation and/or other materials provided with the distribution.
50 * 3. Neither the name of the University nor the names of its contributors
51 * may be used to endorse or promote products derived from this software
52 * without specific prior written permission.
53 *
54 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
55 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
56 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
57 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
58 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
59 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
60 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
61 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
62 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
63 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
64 * SUCH DAMAGE.
65 */
66
67 #ifdef _KERNEL_OPT
68 #include "opt_multiprocessor.h"
69 #endif
70
71 /* If building a standalone libkern, don't include mcount. */
72 #if (!defined(_KERNEL) || defined(GPROF)) && !defined(_STANDALONE)
73
74 #include <sys/cdefs.h>
75 #if !defined(lint) && !defined(_KERNEL) && defined(LIBC_SCCS)
76 #if 0
77 static char sccsid[] = "@(#)mcount.c 8.1 (Berkeley) 6/4/93";
78 #else
79 __RCSID("$NetBSD: mcount.c,v 1.18 2024/02/23 13:32:28 christos Exp $");
80 #endif
81 #endif
82
83 #include <sys/param.h>
84 #include <sys/gmon.h>
85 #include <sys/lock.h>
86 #include <sys/proc.h>
87
88 #ifndef _KERNEL
89 #include "reentrant.h"
90 #endif
91
92 #if defined(_REENTRANT) && !defined(_RUMPKERNEL)
93 extern thread_key_t _gmonkey;
94 extern struct gmonparam _gmondummy;
95 struct gmonparam *_m_gmon_alloc(void);
96 #endif
97
98 _MCOUNT_DECL(u_long, u_long)
99 #ifdef _KERNEL
100 __attribute__((__no_instrument_function__))
101 #endif
102 __used;
103
104 /* XXX: make these interfaces */
105 #ifdef _RUMPKERNEL
106 #undef MCOUNT_ENTER
107 #define MCOUNT_ENTER
108 #undef MCOUNT_EXIT
109 #define MCOUNT_EXIT
110 #undef MCOUNT
111 #define MCOUNT
112 #endif
113
114 /*
115 * mcount is called on entry to each function compiled with the profiling
116 * switch set. _mcount(), which is declared in a machine-dependent way
117 * with _MCOUNT_DECL, does the actual work and is either inlined into a
118 * C routine or called by an assembly stub. In any case, this magic is
119 * taken care of by the MCOUNT definition in <machine/profile.h>.
120 *
121 * _mcount updates data structures that represent traversals of the
122 * program's call graph edges. frompc and selfpc are the return
123 * address and function address that represents the given call graph edge.
124 *
125 * Note: the original BSD code used the same variable (frompcindex) for
126 * both frompcindex and frompc. Any reasonable, modern compiler will
127 * perform this optimization.
128 */
129 /* _mcount; may be static, inline, etc */
130 /*LINTED unused*/
_MCOUNT_DECL(u_long frompc,u_long selfpc)131 _MCOUNT_DECL(u_long frompc, u_long selfpc)
132 {
133 u_short *frompcindex;
134 struct tostruct *top, *prevtop;
135 struct gmonparam *p;
136 long toindex;
137 #if defined(_KERNEL) && !defined(_RUMPKERNEL)
138 int s;
139 #endif
140
141 #if defined(_REENTRANT) && !defined(_KERNEL) && !defined(_RUMPKERNEL)
142 if (__isthreaded) {
143 /* prevent re-entry via thr_getspecific */
144 if (_gmonparam.state != GMON_PROF_ON)
145 return;
146 _gmonparam.state = GMON_PROF_BUSY;
147 p = thr_getspecific(_gmonkey);
148 if (p == NULL) {
149 /* Prevent recursive calls while allocating */
150 thr_setspecific(_gmonkey, &_gmondummy);
151 p = _m_gmon_alloc();
152 }
153 _gmonparam.state = GMON_PROF_ON;
154 } else
155 #endif
156 p = &_gmonparam;
157 /*
158 * check that we are profiling
159 * and that we aren't recursively invoked.
160 */
161 if (p->state != GMON_PROF_ON)
162 return;
163 #if defined(_KERNEL) && !defined(_RUMPKERNEL)
164 MCOUNT_ENTER;
165 #ifdef MULTIPROCESSOR
166 p = curcpu()->ci_gmon;
167 if (p == NULL || p->state != GMON_PROF_ON) {
168 MCOUNT_EXIT;
169 return;
170 }
171 #endif
172 #endif
173 p->state = GMON_PROF_BUSY;
174 /*
175 * check that frompcindex is a reasonable pc value.
176 * for example: signal catchers get called from the stack,
177 * not from text space. too bad.
178 */
179 frompc -= p->lowpc;
180 if (frompc > p->textsize)
181 goto done;
182
183 #if (HASHFRACTION & (HASHFRACTION - 1)) == 0
184 if (p->hashfraction == HASHFRACTION)
185 frompcindex =
186 &p->froms[
187 (size_t)(frompc / (HASHFRACTION * sizeof(*p->froms)))];
188 else
189 #endif
190 frompcindex =
191 &p->froms[
192 (size_t)(frompc / (p->hashfraction * sizeof(*p->froms)))];
193 toindex = *frompcindex;
194 if (toindex == 0) {
195 /*
196 * first time traversing this arc
197 */
198 toindex = ++p->tos[0].link;
199 if (toindex >= p->tolimit)
200 /* halt further profiling */
201 goto overflow;
202
203 *frompcindex = (u_short)toindex;
204 top = &p->tos[(size_t)toindex];
205 top->selfpc = selfpc;
206 top->count = 1;
207 top->link = 0;
208 goto done;
209 }
210 top = &p->tos[(size_t)toindex];
211 if (top->selfpc == selfpc) {
212 /*
213 * arc at front of chain; usual case.
214 */
215 top->count++;
216 goto done;
217 }
218 /*
219 * have to go looking down chain for it.
220 * top points to what we are looking at,
221 * prevtop points to previous top.
222 * we know it is not at the head of the chain.
223 */
224 for (; /* goto done */; ) {
225 if (top->link == 0) {
226 /*
227 * top is end of the chain and none of the chain
228 * had top->selfpc == selfpc.
229 * so we allocate a new tostruct
230 * and link it to the head of the chain.
231 */
232 toindex = ++p->tos[0].link;
233 if (toindex >= p->tolimit)
234 goto overflow;
235
236 top = &p->tos[(size_t)toindex];
237 top->selfpc = selfpc;
238 top->count = 1;
239 top->link = *frompcindex;
240 *frompcindex = (u_short)toindex;
241 goto done;
242 }
243 /*
244 * otherwise, check the next arc on the chain.
245 */
246 prevtop = top;
247 top = &p->tos[top->link];
248 if (top->selfpc == selfpc) {
249 /*
250 * there it is.
251 * increment its count
252 * move it to the head of the chain.
253 */
254 top->count++;
255 toindex = prevtop->link;
256 prevtop->link = top->link;
257 top->link = *frompcindex;
258 *frompcindex = (u_short)toindex;
259 goto done;
260 }
261 }
262 done:
263 p->state = GMON_PROF_ON;
264 #if defined(_KERNEL) && !defined(_RUMPKERNEL)
265 MCOUNT_EXIT;
266 #endif
267 return;
268
269 overflow:
270 p->state = GMON_PROF_ERROR;
271 #if defined(_KERNEL) && !defined(_RUMPKERNEL)
272 MCOUNT_EXIT;
273 #endif
274 return;
275 }
276
277 #ifdef MCOUNT
278 /*
279 * Actual definition of mcount function. Defined in <machine/profile.h>,
280 * which is included by <sys/gmon.h>.
281 */
282 MCOUNT
283 #endif
284
285 #if defined(_KERNEL) && !defined(_RUMPKERNEL) && defined(MULTIPROCESSOR)
286 void _gmonparam_merge(struct gmonparam *, struct gmonparam *);
287
288 void
_gmonparam_merge(struct gmonparam * p,struct gmonparam * q)289 _gmonparam_merge(struct gmonparam *p, struct gmonparam *q)
290 {
291 u_long fromindex;
292 u_short *frompcindex, qtoindex, toindex;
293 u_long selfpc;
294 u_long endfrom;
295 long count;
296 struct tostruct *top;
297 int i;
298
299 count = q->kcountsize / sizeof(*q->kcount);
300 for (i = 0; i < count; i++)
301 p->kcount[i] += q->kcount[i];
302
303 endfrom = (q->fromssize / sizeof(*q->froms));
304 for (fromindex = 0; fromindex < endfrom; fromindex++) {
305 if (q->froms[fromindex] == 0)
306 continue;
307 for (qtoindex = q->froms[fromindex]; qtoindex != 0;
308 qtoindex = q->tos[qtoindex].link) {
309 selfpc = q->tos[qtoindex].selfpc;
310 count = q->tos[qtoindex].count;
311 /* cribbed from mcount */
312 frompcindex = &p->froms[fromindex];
313 toindex = *frompcindex;
314 if (toindex == 0) {
315 /*
316 * first time traversing this arc
317 */
318 toindex = ++p->tos[0].link;
319 if (toindex >= p->tolimit)
320 /* halt further profiling */
321 goto overflow;
322
323 *frompcindex = (u_short)toindex;
324 top = &p->tos[(size_t)toindex];
325 top->selfpc = selfpc;
326 top->count = count;
327 top->link = 0;
328 goto done;
329 }
330 top = &p->tos[(size_t)toindex];
331 if (top->selfpc == selfpc) {
332 /*
333 * arc at front of chain; usual case.
334 */
335 top->count+= count;
336 goto done;
337 }
338 /*
339 * have to go looking down chain for it.
340 * top points to what we are looking at,
341 * we know it is not at the head of the chain.
342 */
343 for (; /* goto done */; ) {
344 if (top->link == 0) {
345 /*
346 * top is end of the chain and
347 * none of the chain had
348 * top->selfpc == selfpc. so
349 * we allocate a new tostruct
350 * and link it to the head of
351 * the chain.
352 */
353 toindex = ++p->tos[0].link;
354 if (toindex >= p->tolimit)
355 goto overflow;
356
357 top = &p->tos[(size_t)toindex];
358 top->selfpc = selfpc;
359 top->count = count;
360 top->link = *frompcindex;
361 *frompcindex = (u_short)toindex;
362 goto done;
363 }
364 /*
365 * otherwise, check the next arc on the chain.
366 */
367 top = &p->tos[top->link];
368 if (top->selfpc == selfpc) {
369 /*
370 * there it is.
371 * add to its count.
372 */
373 top->count += count;
374 goto done;
375 }
376 }
377
378 done: ;
379 }
380
381 }
382 overflow: ;
383
384 }
385 #endif
386
387 #endif /* (!_KERNEL || GPROF) && !_STANDALONE */
388