mcount.c revision 1.1
1 /* $NetBSD: mcount.c,v 1.1 2005/12/20 19:28:51 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(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 1.1 2005/12/20 19:28:51 christos Exp $"); 80 #endif 81 #endif 82 83 #include <sys/param.h> 84 #include <sys/gmon.h> 85 86 #include "reentrant.h" 87 88 #ifdef _REENTRANT 89 extern thread_key_t _gmonkey; 90 extern struct gmonparam _gmondummy; 91 struct gmonparam *_m_gmon_alloc(void); 92 #endif 93 94 _MCOUNT_DECL __P((u_long, u_long)) 95 #ifdef _KERNEL 96 __attribute__((__unused__,__no_instrument_function__)); /* see below. */ 97 #else 98 #ifdef __vax__ 99 _MCOUNT_DECL __P((u_long, u_long)) __attribute__((__unused__)); /* see below. */ 100 #else 101 _MCOUNT_DECL __P((u_long, u_long)) __attribute__((__used__)); /* see below. */ 102 #endif 103 #endif 104 105 /* 106 * mcount is called on entry to each function compiled with the profiling 107 * switch set. _mcount(), which is declared in a machine-dependent way 108 * with _MCOUNT_DECL, does the actual work and is either inlined into a 109 * C routine or called by an assembly stub. In any case, this magic is 110 * taken care of by the MCOUNT definition in <machine/profile.h>. 111 * 112 * _mcount updates data structures that represent traversals of the 113 * program's call graph edges. frompc and selfpc are the return 114 * address and function address that represents the given call graph edge. 115 * 116 * Note: the original BSD code used the same variable (frompcindex) for 117 * both frompcindex and frompc. Any reasonable, modern compiler will 118 * perform this optimization. 119 */ 120 _MCOUNT_DECL(frompc, selfpc) /* _mcount; may be static, inline, etc */ 121 u_long frompc, selfpc; 122 { 123 u_short *frompcindex; 124 struct tostruct *top, *prevtop; 125 struct gmonparam *p; 126 long toindex; 127 #ifdef _KERNEL 128 int s; 129 #endif 130 131 #if defined(_REENTRANT) && !defined(_KERNEL) 132 if (__isthreaded) { 133 p = thr_getspecific(_gmonkey); 134 if (p == NULL) { 135 /* Prevent recursive calls while allocating */ 136 thr_setspecific(_gmonkey, &_gmondummy); 137 p = _m_gmon_alloc(); 138 } 139 } else 140 #endif 141 p = &_gmonparam; 142 /* 143 * check that we are profiling 144 * and that we aren't recursively invoked. 145 */ 146 if (p->state != GMON_PROF_ON) 147 return; 148 #ifdef _KERNEL 149 MCOUNT_ENTER; 150 #endif 151 p->state = GMON_PROF_BUSY; 152 /* 153 * check that frompcindex is a reasonable pc value. 154 * for example: signal catchers get called from the stack, 155 * not from text space. too bad. 156 */ 157 frompc -= p->lowpc; 158 if (frompc > p->textsize) 159 goto done; 160 161 #if (HASHFRACTION & (HASHFRACTION - 1)) == 0 162 if (p->hashfraction == HASHFRACTION) 163 frompcindex = 164 &p->froms[ 165 (size_t)(frompc / (HASHFRACTION * sizeof(*p->froms)))]; 166 else 167 #endif 168 frompcindex = 169 &p->froms[ 170 (size_t)(frompc / (p->hashfraction * sizeof(*p->froms)))]; 171 toindex = *frompcindex; 172 if (toindex == 0) { 173 /* 174 * first time traversing this arc 175 */ 176 toindex = ++p->tos[0].link; 177 if (toindex >= p->tolimit) 178 /* halt further profiling */ 179 goto overflow; 180 181 *frompcindex = (u_short)toindex; 182 top = &p->tos[(size_t)toindex]; 183 top->selfpc = selfpc; 184 top->count = 1; 185 top->link = 0; 186 goto done; 187 } 188 top = &p->tos[(size_t)toindex]; 189 if (top->selfpc == selfpc) { 190 /* 191 * arc at front of chain; usual case. 192 */ 193 top->count++; 194 goto done; 195 } 196 /* 197 * have to go looking down chain for it. 198 * top points to what we are looking at, 199 * prevtop points to previous top. 200 * we know it is not at the head of the chain. 201 */ 202 for (; /* goto done */; ) { 203 if (top->link == 0) { 204 /* 205 * top is end of the chain and none of the chain 206 * had top->selfpc == selfpc. 207 * so we allocate a new tostruct 208 * and link it to the head of the chain. 209 */ 210 toindex = ++p->tos[0].link; 211 if (toindex >= p->tolimit) 212 goto overflow; 213 214 top = &p->tos[(size_t)toindex]; 215 top->selfpc = selfpc; 216 top->count = 1; 217 top->link = *frompcindex; 218 *frompcindex = (u_short)toindex; 219 goto done; 220 } 221 /* 222 * otherwise, check the next arc on the chain. 223 */ 224 prevtop = top; 225 top = &p->tos[top->link]; 226 if (top->selfpc == selfpc) { 227 /* 228 * there it is. 229 * increment its count 230 * move it to the head of the chain. 231 */ 232 top->count++; 233 toindex = prevtop->link; 234 prevtop->link = top->link; 235 top->link = *frompcindex; 236 *frompcindex = (u_short)toindex; 237 goto done; 238 } 239 240 } 241 done: 242 p->state = GMON_PROF_ON; 243 #ifdef _KERNEL 244 MCOUNT_EXIT; 245 #endif 246 return; 247 overflow: 248 p->state = GMON_PROF_ERROR; 249 #ifdef _KERNEL 250 MCOUNT_EXIT; 251 #endif 252 return; 253 } 254 255 #ifdef MCOUNT 256 /* 257 * Actual definition of mcount function. Defined in <machine/profile.h>, 258 * which is included by <sys/gmon.h>. 259 */ 260 MCOUNT 261 #endif 262 263 #endif /* GPROF && !_STANDALONE */ 264
Indexes created Tue Sep 23 07:09:52 GMT 2025