1 | /* $NetBSD: mcount.c,v 1.13 2016/02/28 02:56:39 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 | /* 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 1.13 2016/02/28 02:56:39 christos Exp $" ); |
80 | #endif |
81 | #endif |
82 | |
83 | #include <sys/param.h> |
84 | #include <sys/gmon.h> |
85 | #include <sys/lock.h> |
86 | |
87 | #ifndef _KERNEL |
88 | #include "reentrant.h" |
89 | #endif |
90 | |
91 | #ifdef _REENTRANT |
92 | extern thread_key_t _gmonkey; |
93 | extern struct gmonparam _gmondummy; |
94 | struct gmonparam *_m_gmon_alloc(void); |
95 | #endif |
96 | |
97 | #if defined(_KERNEL) && !defined(_RUMPKERNEL) && defined(MULTIPROCESSOR) |
98 | __cpu_simple_lock_t __mcount_lock; |
99 | #endif |
100 | |
101 | #ifndef __LINT__ |
102 | _MCOUNT_DECL(u_long, u_long) |
103 | #ifdef _KERNEL |
104 | __attribute__((__no_instrument_function__)) |
105 | #endif |
106 | __used; |
107 | #endif |
108 | |
109 | /* XXX: make these interfaces */ |
110 | #ifdef _RUMPKERNEL |
111 | #undef MCOUNT_ENTER |
112 | #define MCOUNT_ENTER |
113 | #undef MCOUNT_EXIT |
114 | #define MCOUNT_EXIT |
115 | #undef MCOUNT |
116 | #define MCOUNT |
117 | #endif |
118 | |
119 | /* |
120 | * mcount is called on entry to each function compiled with the profiling |
121 | * switch set. _mcount(), which is declared in a machine-dependent way |
122 | * with _MCOUNT_DECL, does the actual work and is either inlined into a |
123 | * C routine or called by an assembly stub. In any case, this magic is |
124 | * taken care of by the MCOUNT definition in <machine/profile.h>. |
125 | * |
126 | * _mcount updates data structures that represent traversals of the |
127 | * program's call graph edges. frompc and selfpc are the return |
128 | * address and function address that represents the given call graph edge. |
129 | * |
130 | * Note: the original BSD code used the same variable (frompcindex) for |
131 | * both frompcindex and frompc. Any reasonable, modern compiler will |
132 | * perform this optimization. |
133 | */ |
134 | #ifndef __LINT__ |
135 | /* _mcount; may be static, inline, etc */ |
136 | _MCOUNT_DECL(u_long frompc, u_long selfpc) |
137 | { |
138 | u_short *frompcindex; |
139 | struct tostruct *top, *prevtop; |
140 | struct gmonparam *p; |
141 | long toindex; |
142 | #if defined(_KERNEL) && !defined(_RUMPKERNEL) |
143 | int s; |
144 | #endif |
145 | |
146 | #if defined(_REENTRANT) && !defined(_KERNEL) |
147 | if (__isthreaded) { |
148 | /* prevent re-entry via thr_getspecific */ |
149 | if (_gmonparam.state != GMON_PROF_ON) |
150 | return; |
151 | _gmonparam.state = GMON_PROF_BUSY; |
152 | p = thr_getspecific(_gmonkey); |
153 | if (p == NULL) { |
154 | /* Prevent recursive calls while allocating */ |
155 | thr_setspecific(_gmonkey, &_gmondummy); |
156 | p = _m_gmon_alloc(); |
157 | } |
158 | _gmonparam.state = GMON_PROF_ON; |
159 | } else |
160 | #endif |
161 | p = &_gmonparam; |
162 | /* |
163 | * check that we are profiling |
164 | * and that we aren't recursively invoked. |
165 | */ |
166 | if (p->state != GMON_PROF_ON) |
167 | return; |
168 | #if defined(_KERNEL) && !defined(_RUMPKERNEL) |
169 | MCOUNT_ENTER; |
170 | #ifdef MULTIPROCESSOR |
171 | __cpu_simple_lock(&__mcount_lock); |
172 | __insn_barrier(); |
173 | #endif |
174 | #endif |
175 | p->state = GMON_PROF_BUSY; |
176 | /* |
177 | * check that frompcindex is a reasonable pc value. |
178 | * for example: signal catchers get called from the stack, |
179 | * not from text space. too bad. |
180 | */ |
181 | frompc -= p->lowpc; |
182 | if (frompc > p->textsize) |
183 | goto done; |
184 | |
185 | #if (HASHFRACTION & (HASHFRACTION - 1)) == 0 |
186 | if (p->hashfraction == HASHFRACTION) |
187 | frompcindex = |
188 | &p->froms[ |
189 | (size_t)(frompc / (HASHFRACTION * sizeof(*p->froms)))]; |
190 | else |
191 | #endif |
192 | frompcindex = |
193 | &p->froms[ |
194 | (size_t)(frompc / (p->hashfraction * sizeof(*p->froms)))]; |
195 | toindex = *frompcindex; |
196 | if (toindex == 0) { |
197 | /* |
198 | * first time traversing this arc |
199 | */ |
200 | toindex = ++p->tos[0].link; |
201 | if (toindex >= p->tolimit) |
202 | /* halt further profiling */ |
203 | goto overflow; |
204 | |
205 | *frompcindex = (u_short)toindex; |
206 | top = &p->tos[(size_t)toindex]; |
207 | top->selfpc = selfpc; |
208 | top->count = 1; |
209 | top->link = 0; |
210 | goto done; |
211 | } |
212 | top = &p->tos[(size_t)toindex]; |
213 | if (top->selfpc == selfpc) { |
214 | /* |
215 | * arc at front of chain; usual case. |
216 | */ |
217 | top->count++; |
218 | goto done; |
219 | } |
220 | /* |
221 | * have to go looking down chain for it. |
222 | * top points to what we are looking at, |
223 | * prevtop points to previous top. |
224 | * we know it is not at the head of the chain. |
225 | */ |
226 | for (; /* goto done */; ) { |
227 | if (top->link == 0) { |
228 | /* |
229 | * top is end of the chain and none of the chain |
230 | * had top->selfpc == selfpc. |
231 | * so we allocate a new tostruct |
232 | * and link it to the head of the chain. |
233 | */ |
234 | toindex = ++p->tos[0].link; |
235 | if (toindex >= p->tolimit) |
236 | goto overflow; |
237 | |
238 | top = &p->tos[(size_t)toindex]; |
239 | top->selfpc = selfpc; |
240 | top->count = 1; |
241 | top->link = *frompcindex; |
242 | *frompcindex = (u_short)toindex; |
243 | goto done; |
244 | } |
245 | /* |
246 | * otherwise, check the next arc on the chain. |
247 | */ |
248 | prevtop = top; |
249 | top = &p->tos[top->link]; |
250 | if (top->selfpc == selfpc) { |
251 | /* |
252 | * there it is. |
253 | * increment its count |
254 | * move it to the head of the chain. |
255 | */ |
256 | top->count++; |
257 | toindex = prevtop->link; |
258 | prevtop->link = top->link; |
259 | top->link = *frompcindex; |
260 | *frompcindex = (u_short)toindex; |
261 | goto done; |
262 | } |
263 | } |
264 | done: |
265 | p->state = GMON_PROF_ON; |
266 | #if defined(_KERNEL) && !defined(_RUMPKERNEL) |
267 | #ifdef MULTIPROCESSOR |
268 | __insn_barrier(); |
269 | __cpu_simple_unlock(&__mcount_lock); |
270 | #endif |
271 | MCOUNT_EXIT; |
272 | #endif |
273 | return; |
274 | |
275 | overflow: |
276 | p->state = GMON_PROF_ERROR; |
277 | #if defined(_KERNEL) && !defined(_RUMPKERNEL) |
278 | #ifdef MULTIPROCESSOR |
279 | __insn_barrier(); |
280 | __cpu_simple_unlock(&__mcount_lock); |
281 | #endif |
282 | MCOUNT_EXIT; |
283 | #endif |
284 | return; |
285 | } |
286 | #endif |
287 | |
288 | #ifdef MCOUNT |
289 | /* |
290 | * Actual definition of mcount function. Defined in <machine/profile.h>, |
291 | * which is included by <sys/gmon.h>. |
292 | */ |
293 | MCOUNT |
294 | #endif |
295 | |
296 | #endif /* (!_KERNEL || GPROF) && !_STANDALONE */ |
297 | |