1 /* $NetBSD: mcount.c,v 1.10 2012/03/20 16:21:41 matt 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 /* If building a standalone libkern, don't include mcount. */
68 #if (!defined(_KERNEL) || defined(GPROF)) && !defined(_STANDALONE)
69
70 #ifdef _KERNEL_OPT
71 #include "opt_multiprocessor.h"
72 #endif
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 1.10 2012/03/20 16:21:41 matt Exp $");
80 #endif
81 #endif
82
83 #include <sys/param.h>
84 #include <sys/gmon.h>
85
86 #ifndef _KERNEL
87 #include "reentrant.h"
88 #endif
89
90 #ifdef _REENTRANT
91 extern thread_key_t _gmonkey;
92 extern struct gmonparam _gmondummy;
93 struct gmonparam *_m_gmon_alloc(void);
94 #endif
95
96 #ifndef __LINT__
97 _MCOUNT_DECL(u_long, u_long)
98 #ifdef _KERNEL
99 __attribute__((__no_instrument_function__))
100 #endif
101 __used;
102 #endif
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 #ifndef __LINT__
130 /* _mcount; may be static, inline, etc */
_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)
142 if (__isthreaded) {
143 p = thr_getspecific(_gmonkey);
144 if (p == NULL) {
145 /* Prevent recursive calls while allocating */
146 thr_setspecific(_gmonkey, &_gmondummy);
147 p = _m_gmon_alloc();
148 }
149 } else
150 #endif
151 p = &_gmonparam;
152 /*
153 * check that we are profiling
154 * and that we aren't recursively invoked.
155 */
156 if (p->state != GMON_PROF_ON)
157 return;
158 #ifdef _KERNEL
159 MCOUNT_ENTER;
160 #endif
161 p->state = GMON_PROF_BUSY;
162 /*
163 * check that frompcindex is a reasonable pc value.
164 * for example: signal catchers get called from the stack,
165 * not from text space. too bad.
166 */
167 frompc -= p->lowpc;
168 if (frompc > p->textsize)
169 goto done;
170
171 #if (HASHFRACTION & (HASHFRACTION - 1)) == 0
172 if (p->hashfraction == HASHFRACTION)
173 frompcindex =
174 &p->froms[
175 (size_t)(frompc / (HASHFRACTION * sizeof(*p->froms)))];
176 else
177 #endif
178 frompcindex =
179 &p->froms[
180 (size_t)(frompc / (p->hashfraction * sizeof(*p->froms)))];
181 toindex = *frompcindex;
182 if (toindex == 0) {
183 /*
184 * first time traversing this arc
185 */
186 toindex = ++p->tos[0].link;
187 if (toindex >= p->tolimit)
188 /* halt further profiling */
189 goto overflow;
190
191 *frompcindex = (u_short)toindex;
192 top = &p->tos[(size_t)toindex];
193 top->selfpc = selfpc;
194 top->count = 1;
195 top->link = 0;
196 goto done;
197 }
198 top = &p->tos[(size_t)toindex];
199 if (top->selfpc == selfpc) {
200 /*
201 * arc at front of chain; usual case.
202 */
203 top->count++;
204 goto done;
205 }
206 /*
207 * have to go looking down chain for it.
208 * top points to what we are looking at,
209 * prevtop points to previous top.
210 * we know it is not at the head of the chain.
211 */
212 for (; /* goto done */; ) {
213 if (top->link == 0) {
214 /*
215 * top is end of the chain and none of the chain
216 * had top->selfpc == selfpc.
217 * so we allocate a new tostruct
218 * and link it to the head of the chain.
219 */
220 toindex = ++p->tos[0].link;
221 if (toindex >= p->tolimit)
222 goto overflow;
223
224 top = &p->tos[(size_t)toindex];
225 top->selfpc = selfpc;
226 top->count = 1;
227 top->link = *frompcindex;
228 *frompcindex = (u_short)toindex;
229 goto done;
230 }
231 /*
232 * otherwise, check the next arc on the chain.
233 */
234 prevtop = top;
235 top = &p->tos[top->link];
236 if (top->selfpc == selfpc) {
237 /*
238 * there it is.
239 * increment its count
240 * move it to the head of the chain.
241 */
242 top->count++;
243 toindex = prevtop->link;
244 prevtop->link = top->link;
245 top->link = *frompcindex;
246 *frompcindex = (u_short)toindex;
247 goto done;
248 }
249
250 }
251 done:
252 p->state = GMON_PROF_ON;
253 #ifdef _KERNEL
254 MCOUNT_EXIT;
255 #endif
256 return;
257 overflow:
258 p->state = GMON_PROF_ERROR;
259 #ifdef _KERNEL
260 MCOUNT_EXIT;
261 #endif
262 return;
263 }
264 #endif
265
266 #ifdef MCOUNT
267 /*
268 * Actual definition of mcount function. Defined in <machine/profile.h>,
269 * which is included by <sys/gmon.h>.
270 */
271 MCOUNT
272 #endif
273
274 #endif /* (!_KERNEL || GPROF) && !_STANDALONE */
275