mcount.c revision 1.7.2.2
1 /* $NetBSD: mcount.c,v 1.7.2.2 2006/10/27 22:14:14 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 1.7.2.2 2006/10/27 22:14:14 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 __attribute__((__no_instrument_function__)) 99 #endif 100 __used; 101 102 /* 103 * mcount is called on entry to each function compiled with the profiling 104 * switch set. _mcount(), which is declared in a machine-dependent way 105 * with _MCOUNT_DECL, does the actual work and is either inlined into a 106 * C routine or called by an assembly stub. In any case, this magic is 107 * taken care of by the MCOUNT definition in <machine/profile.h>. 108 * 109 * _mcount updates data structures that represent traversals of the 110 * program's call graph edges. frompc and selfpc are the return 111 * address and function address that represents the given call graph edge. 112 * 113 * Note: the original BSD code used the same variable (frompcindex) for 114 * both frompcindex and frompc. Any reasonable, modern compiler will 115 * perform this optimization. 116 */ 117 _MCOUNT_DECL(frompc, selfpc) /* _mcount; may be static, inline, etc */ 118 u_long frompc, selfpc; 119 { 120 u_short *frompcindex; 121 struct tostruct *top, *prevtop; 122 struct gmonparam *p; 123 long toindex; 124 #ifdef _KERNEL 125 int s; 126 #endif 127 128 #if defined(_REENTRANT) && !defined(_KERNEL) 129 if (__isthreaded) { 130 p = thr_getspecific(_gmonkey); 131 if (p == NULL) { 132 /* Prevent recursive calls while allocating */ 133 thr_setspecific(_gmonkey, &_gmondummy); 134 p = _m_gmon_alloc(); 135 } 136 } else 137 #endif 138 p = &_gmonparam; 139 /* 140 * check that we are profiling 141 * and that we aren't recursively invoked. 142 */ 143 if (p->state != GMON_PROF_ON) 144 return; 145 #ifdef _KERNEL 146 MCOUNT_ENTER; 147 #endif 148 p->state = GMON_PROF_BUSY; 149 /* 150 * check that frompcindex is a reasonable pc value. 151 * for example: signal catchers get called from the stack, 152 * not from text space. too bad. 153 */ 154 frompc -= p->lowpc; 155 if (frompc > p->textsize) 156 goto done; 157 158 #if (HASHFRACTION & (HASHFRACTION - 1)) == 0 159 if (p->hashfraction == HASHFRACTION) 160 frompcindex = 161 &p->froms[ 162 (size_t)(frompc / (HASHFRACTION * sizeof(*p->froms)))]; 163 else 164 #endif 165 frompcindex = 166 &p->froms[ 167 (size_t)(frompc / (p->hashfraction * sizeof(*p->froms)))]; 168 toindex = *frompcindex; 169 if (toindex == 0) { 170 /* 171 * first time traversing this arc 172 */ 173 toindex = ++p->tos[0].link; 174 if (toindex >= p->tolimit) 175 /* halt further profiling */ 176 goto overflow; 177 178 *frompcindex = (u_short)toindex; 179 top = &p->tos[(size_t)toindex]; 180 top->selfpc = selfpc; 181 top->count = 1; 182 top->link = 0; 183 goto done; 184 } 185 top = &p->tos[(size_t)toindex]; 186 if (top->selfpc == selfpc) { 187 /* 188 * arc at front of chain; usual case. 189 */ 190 top->count++; 191 goto done; 192 } 193 /* 194 * have to go looking down chain for it. 195 * top points to what we are looking at, 196 * prevtop points to previous top. 197 * we know it is not at the head of the chain. 198 */ 199 for (; /* goto done */; ) { 200 if (top->link == 0) { 201 /* 202 * top is end of the chain and none of the chain 203 * had top->selfpc == selfpc. 204 * so we allocate a new tostruct 205 * and link it to the head of the chain. 206 */ 207 toindex = ++p->tos[0].link; 208 if (toindex >= p->tolimit) 209 goto overflow; 210 211 top = &p->tos[(size_t)toindex]; 212 top->selfpc = selfpc; 213 top->count = 1; 214 top->link = *frompcindex; 215 *frompcindex = (u_short)toindex; 216 goto done; 217 } 218 /* 219 * otherwise, check the next arc on the chain. 220 */ 221 prevtop = top; 222 top = &p->tos[top->link]; 223 if (top->selfpc == selfpc) { 224 /* 225 * there it is. 226 * increment its count 227 * move it to the head of the chain. 228 */ 229 top->count++; 230 toindex = prevtop->link; 231 prevtop->link = top->link; 232 top->link = *frompcindex; 233 *frompcindex = (u_short)toindex; 234 goto done; 235 } 236 237 } 238 done: 239 p->state = GMON_PROF_ON; 240 #ifdef _KERNEL 241 MCOUNT_EXIT; 242 #endif 243 return; 244 overflow: 245 p->state = GMON_PROF_ERROR; 246 #ifdef _KERNEL 247 MCOUNT_EXIT; 248 #endif 249 return; 250 } 251 252 #ifdef MCOUNT 253 /* 254 * Actual definition of mcount function. Defined in <machine/profile.h>, 255 * which is included by <sys/gmon.h>. 256 */ 257 MCOUNT 258 #endif 259 260 #endif /* (!_KERNEL || GPROF) && !_STANDALONE */ 261
Indexes created Wed Oct 01 13:09:50 GMT 2025