mcount.c revision 1.3
1 /* $NetBSD: mcount.c,v 1.3 2005/12/21 16:58:04 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 #ifndef _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 1.3 2005/12/21 16:58:04 christos 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__((__unused__,__no_instrument_function__)); /* see below. */ 99 #else 100 #ifdef __vax__ 101 __attribute__((__unused__)); /* see below. */ 102 #else 103 __attribute__((__used__)); /* see below. */ 104 #endif 105 #endif 106 107 /* 108 * mcount is called on entry to each function compiled with the profiling 109 * switch set. _mcount(), which is declared in a machine-dependent way 110 * with _MCOUNT_DECL, does the actual work and is either inlined into a 111 * C routine or called by an assembly stub. In any case, this magic is 112 * taken care of by the MCOUNT definition in <machine/profile.h>. 113 * 114 * _mcount updates data structures that represent traversals of the 115 * program's call graph edges. frompc and selfpc are the return 116 * address and function address that represents the given call graph edge. 117 * 118 * Note: the original BSD code used the same variable (frompcindex) for 119 * both frompcindex and frompc. Any reasonable, modern compiler will 120 * perform this optimization. 121 */ 122 _MCOUNT_DECL(frompc, selfpc) /* _mcount; may be static, inline, etc */ 123 u_long frompc, selfpc; 124 { 125 u_short *frompcindex; 126 struct tostruct *top, *prevtop; 127 struct gmonparam *p; 128 long toindex; 129 #ifdef _KERNEL 130 int s; 131 #endif 132 133 #if defined(_REENTRANT) && !defined(_KERNEL) 134 if (__isthreaded) { 135 p = thr_getspecific(_gmonkey); 136 if (p == NULL) { 137 /* Prevent recursive calls while allocating */ 138 thr_setspecific(_gmonkey, &_gmondummy); 139 p = _m_gmon_alloc(); 140 } 141 } else 142 #endif 143 p = &_gmonparam; 144 /* 145 * check that we are profiling 146 * and that we aren't recursively invoked. 147 */ 148 if (p->state != GMON_PROF_ON) 149 return; 150 #ifdef _KERNEL 151 MCOUNT_ENTER; 152 #endif 153 p->state = GMON_PROF_BUSY; 154 /* 155 * check that frompcindex is a reasonable pc value. 156 * for example: signal catchers get called from the stack, 157 * not from text space. too bad. 158 */ 159 frompc -= p->lowpc; 160 if (frompc > p->textsize) 161 goto done; 162 163 #if (HASHFRACTION & (HASHFRACTION - 1)) == 0 164 if (p->hashfraction == HASHFRACTION) 165 frompcindex = 166 &p->froms[ 167 (size_t)(frompc / (HASHFRACTION * sizeof(*p->froms)))]; 168 else 169 #endif 170 frompcindex = 171 &p->froms[ 172 (size_t)(frompc / (p->hashfraction * sizeof(*p->froms)))]; 173 toindex = *frompcindex; 174 if (toindex == 0) { 175 /* 176 * first time traversing this arc 177 */ 178 toindex = ++p->tos[0].link; 179 if (toindex >= p->tolimit) 180 /* halt further profiling */ 181 goto overflow; 182 183 *frompcindex = (u_short)toindex; 184 top = &p->tos[(size_t)toindex]; 185 top->selfpc = selfpc; 186 top->count = 1; 187 top->link = 0; 188 goto done; 189 } 190 top = &p->tos[(size_t)toindex]; 191 if (top->selfpc == selfpc) { 192 /* 193 * arc at front of chain; usual case. 194 */ 195 top->count++; 196 goto done; 197 } 198 /* 199 * have to go looking down chain for it. 200 * top points to what we are looking at, 201 * prevtop points to previous top. 202 * we know it is not at the head of the chain. 203 */ 204 for (; /* goto done */; ) { 205 if (top->link == 0) { 206 /* 207 * top is end of the chain and none of the chain 208 * had top->selfpc == selfpc. 209 * so we allocate a new tostruct 210 * and link it to the head of the chain. 211 */ 212 toindex = ++p->tos[0].link; 213 if (toindex >= p->tolimit) 214 goto overflow; 215 216 top = &p->tos[(size_t)toindex]; 217 top->selfpc = selfpc; 218 top->count = 1; 219 top->link = *frompcindex; 220 *frompcindex = (u_short)toindex; 221 goto done; 222 } 223 /* 224 * otherwise, check the next arc on the chain. 225 */ 226 prevtop = top; 227 top = &p->tos[top->link]; 228 if (top->selfpc == selfpc) { 229 /* 230 * there it is. 231 * increment its count 232 * move it to the head of the chain. 233 */ 234 top->count++; 235 toindex = prevtop->link; 236 prevtop->link = top->link; 237 top->link = *frompcindex; 238 *frompcindex = (u_short)toindex; 239 goto done; 240 } 241 242 } 243 done: 244 p->state = GMON_PROF_ON; 245 #ifdef _KERNEL 246 MCOUNT_EXIT; 247 #endif 248 return; 249 overflow: 250 p->state = GMON_PROF_ERROR; 251 #ifdef _KERNEL 252 MCOUNT_EXIT; 253 #endif 254 return; 255 } 256 257 #ifdef MCOUNT 258 /* 259 * Actual definition of mcount function. Defined in <machine/profile.h>, 260 * which is included by <sys/gmon.h>. 261 */ 262 MCOUNT 263 #endif 264 265 #endif /* !_STANDALONE */ 266
Indexes created Sun Sep 21 20:09:37 GMT 2025