mcount.c revision 1.6
1 /* $NetBSD: mcount.c,v 1.6 2006/10/26 23:10:16 uwe 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 1.6 2006/10/26 23:10:16 uwe 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 _MCOUNT_DECL __P((u_long, u_long)) 97 #ifdef _KERNEL 98 #ifdef __vax__ 99 __attribute__((__unused__,__no_instrument_function__)); /* see below. */ 100 #else 101 __attribute__((__used__,__no_instrument_function__)); /* see below. */ 102 #endif 103 #else 104 #ifdef __vax__ 105 __attribute__((__unused__)); /* see below. */ 106 #else 107 __attribute__((__used__)); /* see below. */ 108 #endif 109 #endif 110 111 /* 112 * mcount is called on entry to each function compiled with the profiling 113 * switch set. _mcount(), which is declared in a machine-dependent way 114 * with _MCOUNT_DECL, does the actual work and is either inlined into a 115 * C routine or called by an assembly stub. In any case, this magic is 116 * taken care of by the MCOUNT definition in <machine/profile.h>. 117 * 118 * _mcount updates data structures that represent traversals of the 119 * program's call graph edges. frompc and selfpc are the return 120 * address and function address that represents the given call graph edge. 121 * 122 * Note: the original BSD code used the same variable (frompcindex) for 123 * both frompcindex and frompc. Any reasonable, modern compiler will 124 * perform this optimization. 125 */ 126 _MCOUNT_DECL(frompc, selfpc) /* _mcount; may be static, inline, etc */ 127 u_long frompc, selfpc; 128 { 129 u_short *frompcindex; 130 struct tostruct *top, *prevtop; 131 struct gmonparam *p; 132 long toindex; 133 #ifdef _KERNEL 134 int s; 135 #endif 136 137 #if defined(_REENTRANT) && !defined(_KERNEL) 138 if (__isthreaded) { 139 p = thr_getspecific(_gmonkey); 140 if (p == NULL) { 141 /* Prevent recursive calls while allocating */ 142 thr_setspecific(_gmonkey, &_gmondummy); 143 p = _m_gmon_alloc(); 144 } 145 } else 146 #endif 147 p = &_gmonparam; 148 /* 149 * check that we are profiling 150 * and that we aren't recursively invoked. 151 */ 152 if (p->state != GMON_PROF_ON) 153 return; 154 #ifdef _KERNEL 155 MCOUNT_ENTER; 156 #endif 157 p->state = GMON_PROF_BUSY; 158 /* 159 * check that frompcindex is a reasonable pc value. 160 * for example: signal catchers get called from the stack, 161 * not from text space. too bad. 162 */ 163 frompc -= p->lowpc; 164 if (frompc > p->textsize) 165 goto done; 166 167 #if (HASHFRACTION & (HASHFRACTION - 1)) == 0 168 if (p->hashfraction == HASHFRACTION) 169 frompcindex = 170 &p->froms[ 171 (size_t)(frompc / (HASHFRACTION * sizeof(*p->froms)))]; 172 else 173 #endif 174 frompcindex = 175 &p->froms[ 176 (size_t)(frompc / (p->hashfraction * sizeof(*p->froms)))]; 177 toindex = *frompcindex; 178 if (toindex == 0) { 179 /* 180 * first time traversing this arc 181 */ 182 toindex = ++p->tos[0].link; 183 if (toindex >= p->tolimit) 184 /* halt further profiling */ 185 goto overflow; 186 187 *frompcindex = (u_short)toindex; 188 top = &p->tos[(size_t)toindex]; 189 top->selfpc = selfpc; 190 top->count = 1; 191 top->link = 0; 192 goto done; 193 } 194 top = &p->tos[(size_t)toindex]; 195 if (top->selfpc == selfpc) { 196 /* 197 * arc at front of chain; usual case. 198 */ 199 top->count++; 200 goto done; 201 } 202 /* 203 * have to go looking down chain for it. 204 * top points to what we are looking at, 205 * prevtop points to previous top. 206 * we know it is not at the head of the chain. 207 */ 208 for (; /* goto done */; ) { 209 if (top->link == 0) { 210 /* 211 * top is end of the chain and none of the chain 212 * had top->selfpc == selfpc. 213 * so we allocate a new tostruct 214 * and link it to the head of the chain. 215 */ 216 toindex = ++p->tos[0].link; 217 if (toindex >= p->tolimit) 218 goto overflow; 219 220 top = &p->tos[(size_t)toindex]; 221 top->selfpc = selfpc; 222 top->count = 1; 223 top->link = *frompcindex; 224 *frompcindex = (u_short)toindex; 225 goto done; 226 } 227 /* 228 * otherwise, check the next arc on the chain. 229 */ 230 prevtop = top; 231 top = &p->tos[top->link]; 232 if (top->selfpc == selfpc) { 233 /* 234 * there it is. 235 * increment its count 236 * move it to the head of the chain. 237 */ 238 top->count++; 239 toindex = prevtop->link; 240 prevtop->link = top->link; 241 top->link = *frompcindex; 242 *frompcindex = (u_short)toindex; 243 goto done; 244 } 245 246 } 247 done: 248 p->state = GMON_PROF_ON; 249 #ifdef _KERNEL 250 MCOUNT_EXIT; 251 #endif 252 return; 253 overflow: 254 p->state = GMON_PROF_ERROR; 255 #ifdef _KERNEL 256 MCOUNT_EXIT; 257 #endif 258 return; 259 } 260 261 #ifdef MCOUNT 262 /* 263 * Actual definition of mcount function. Defined in <machine/profile.h>, 264 * which is included by <sys/gmon.h>. 265 */ 266 MCOUNT 267 #endif 268 269 #endif /* (!_KERNEL || GPROF) && !_STANDALONE */ 270
Indexes created Wed Oct 01 13:09:50 GMT 2025