mcount.c revision 1.9
1 /* $NetBSD: mcount.c,v 1.9 2012/03/17 21:40:21 martin 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 1.9 2012/03/17 21:40:21 martin 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 #ifndef __LINT__ 97 _MCOUNT_DECL __P((u_long, u_long)) 98 #ifdef _KERNEL 99 __attribute__((__no_instrument_function__)) 100 #endif 101 __used; 102 #endif 103 104 /* XXX: make these interfaces */ 105 #ifdef _RUMPKERNEL 106 #undef MCOUNT_ENTER 107 #define MCOUNT_ENTER 108 #undef MCOUNT_EXIT 109 #define MCOUNT_EXIT 110 #undef MCOUNT 111 #define MCOUNT 112 #endif 113 114 /* 115 * mcount is called on entry to each function compiled with the profiling 116 * switch set. _mcount(), which is declared in a machine-dependent way 117 * with _MCOUNT_DECL, does the actual work and is either inlined into a 118 * C routine or called by an assembly stub. In any case, this magic is 119 * taken care of by the MCOUNT definition in <machine/profile.h>. 120 * 121 * _mcount updates data structures that represent traversals of the 122 * program's call graph edges. frompc and selfpc are the return 123 * address and function address that represents the given call graph edge. 124 * 125 * Note: the original BSD code used the same variable (frompcindex) for 126 * both frompcindex and frompc. Any reasonable, modern compiler will 127 * perform this optimization. 128 */ 129 #ifndef __LINT__ 130 _MCOUNT_DECL(frompc, selfpc) /* _mcount; may be static, inline, etc */ 131 u_long frompc, selfpc; 132 { 133 u_short *frompcindex; 134 struct tostruct *top, *prevtop; 135 struct gmonparam *p; 136 long toindex; 137 #if defined(_KERNEL) && !defined(_RUMPKERNEL) 138 int s; 139 #endif 140 141 #if defined(_REENTRANT) && !defined(_KERNEL) 142 if (__isthreaded) { 143 p = thr_getspecific(_gmonkey); 144 if (p == NULL) { 145 /* Prevent recursive calls while allocating */ 146 thr_setspecific(_gmonkey, &_gmondummy); 147 p = _m_gmon_alloc(); 148 } 149 } else 150 #endif 151 p = &_gmonparam; 152 /* 153 * check that we are profiling 154 * and that we aren't recursively invoked. 155 */ 156 if (p->state != GMON_PROF_ON) 157 return; 158 #ifdef _KERNEL 159 MCOUNT_ENTER; 160 #endif 161 p->state = GMON_PROF_BUSY; 162 /* 163 * check that frompcindex is a reasonable pc value. 164 * for example: signal catchers get called from the stack, 165 * not from text space. too bad. 166 */ 167 frompc -= p->lowpc; 168 if (frompc > p->textsize) 169 goto done; 170 171 #if (HASHFRACTION & (HASHFRACTION - 1)) == 0 172 if (p->hashfraction == HASHFRACTION) 173 frompcindex = 174 &p->froms[ 175 (size_t)(frompc / (HASHFRACTION * sizeof(*p->froms)))]; 176 else 177 #endif 178 frompcindex = 179 &p->froms[ 180 (size_t)(frompc / (p->hashfraction * sizeof(*p->froms)))]; 181 toindex = *frompcindex; 182 if (toindex == 0) { 183 /* 184 * first time traversing this arc 185 */ 186 toindex = ++p->tos[0].link; 187 if (toindex >= p->tolimit) 188 /* halt further profiling */ 189 goto overflow; 190 191 *frompcindex = (u_short)toindex; 192 top = &p->tos[(size_t)toindex]; 193 top->selfpc = selfpc; 194 top->count = 1; 195 top->link = 0; 196 goto done; 197 } 198 top = &p->tos[(size_t)toindex]; 199 if (top->selfpc == selfpc) { 200 /* 201 * arc at front of chain; usual case. 202 */ 203 top->count++; 204 goto done; 205 } 206 /* 207 * have to go looking down chain for it. 208 * top points to what we are looking at, 209 * prevtop points to previous top. 210 * we know it is not at the head of the chain. 211 */ 212 for (; /* goto done */; ) { 213 if (top->link == 0) { 214 /* 215 * top is end of the chain and none of the chain 216 * had top->selfpc == selfpc. 217 * so we allocate a new tostruct 218 * and link it to the head of the chain. 219 */ 220 toindex = ++p->tos[0].link; 221 if (toindex >= p->tolimit) 222 goto overflow; 223 224 top = &p->tos[(size_t)toindex]; 225 top->selfpc = selfpc; 226 top->count = 1; 227 top->link = *frompcindex; 228 *frompcindex = (u_short)toindex; 229 goto done; 230 } 231 /* 232 * otherwise, check the next arc on the chain. 233 */ 234 prevtop = top; 235 top = &p->tos[top->link]; 236 if (top->selfpc == selfpc) { 237 /* 238 * there it is. 239 * increment its count 240 * move it to the head of the chain. 241 */ 242 top->count++; 243 toindex = prevtop->link; 244 prevtop->link = top->link; 245 top->link = *frompcindex; 246 *frompcindex = (u_short)toindex; 247 goto done; 248 } 249 250 } 251 done: 252 p->state = GMON_PROF_ON; 253 #ifdef _KERNEL 254 MCOUNT_EXIT; 255 #endif 256 return; 257 overflow: 258 p->state = GMON_PROF_ERROR; 259 #ifdef _KERNEL 260 MCOUNT_EXIT; 261 #endif 262 return; 263 } 264 #endif 265 266 #ifdef MCOUNT 267 /* 268 * Actual definition of mcount function. Defined in <machine/profile.h>, 269 * which is included by <sys/gmon.h>. 270 */ 271 MCOUNT 272 #endif 273 274 #endif /* (!_KERNEL || GPROF) && !_STANDALONE */ 275
Indexes created Wed Oct 01 13:09:50 GMT 2025