1 /* $NetBSD: mcount.c,v 1.8 2009/01/05 18:06:57 pooka 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 1.8 2009/01/05 18:06:57 pooka 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 /* XXX: make these interfaces */ 103 #ifdef _RUMPKERNEL 104 #undef MCOUNT_ENTER 105 #define MCOUNT_ENTER 106 #undef MCOUNT_EXIT 107 #define MCOUNT_EXIT 108 #undef MCOUNT 109 #define MCOUNT 110 #endif 111 112 /* 113 * mcount is called on entry to each function compiled with the profiling 114 * switch set. _mcount(), which is declared in a machine-dependent way 115 * with _MCOUNT_DECL, does the actual work and is either inlined into a 116 * C routine or called by an assembly stub. In any case, this magic is 117 * taken care of by the MCOUNT definition in <machine/profile.h>. 118 * 119 * _mcount updates data structures that represent traversals of the 120 * program's call graph edges. frompc and selfpc are the return 121 * address and function address that represents the given call graph edge. 122 * 123 * Note: the original BSD code used the same variable (frompcindex) for 124 * both frompcindex and frompc. Any reasonable, modern compiler will 125 * perform this optimization. 126 */ 127 _MCOUNT_DECL(frompc, selfpc) /* _mcount; may be static, inline, etc */ 128 u_long frompc, selfpc; 129 { 130 u_short *frompcindex; 131 struct tostruct *top, *prevtop; 132 struct gmonparam *p; 133 long toindex; 134 #if defined(_KERNEL) && !defined(_RUMPKERNEL) 135 int s; 136 #endif 137 138 #if defined(_REENTRANT) && !defined(_KERNEL) 139 if (__isthreaded) { 140 p = thr_getspecific(_gmonkey); 141 if (p == NULL) { 142 /* Prevent recursive calls while allocating */ 143 thr_setspecific(_gmonkey, &_gmondummy); 144 p = _m_gmon_alloc(); 145 } 146 } else 147 #endif 148 p = &_gmonparam; 149 /* 150 * check that we are profiling 151 * and that we aren't recursively invoked. 152 */ 153 if (p->state != GMON_PROF_ON) 154 return; 155 #ifdef _KERNEL 156 MCOUNT_ENTER; 157 #endif 158 p->state = GMON_PROF_BUSY; 159 /* 160 * check that frompcindex is a reasonable pc value. 161 * for example: signal catchers get called from the stack, 162 * not from text space. too bad. 163 */ 164 frompc -= p->lowpc; 165 if (frompc > p->textsize) 166 goto done; 167 168 #if (HASHFRACTION & (HASHFRACTION - 1)) == 0 169 if (p->hashfraction == HASHFRACTION) 170 frompcindex = 171 &p->froms[ 172 (size_t)(frompc / (HASHFRACTION * sizeof(*p->froms)))]; 173 else 174 #endif 175 frompcindex = 176 &p->froms[ 177 (size_t)(frompc / (p->hashfraction * sizeof(*p->froms)))]; 178 toindex = *frompcindex; 179 if (toindex == 0) { 180 /* 181 * first time traversing this arc 182 */ 183 toindex = ++p->tos[0].link; 184 if (toindex >= p->tolimit) 185 /* halt further profiling */ 186 goto overflow; 187 188 *frompcindex = (u_short)toindex; 189 top = &p->tos[(size_t)toindex]; 190 top->selfpc = selfpc; 191 top->count = 1; 192 top->link = 0; 193 goto done; 194 } 195 top = &p->tos[(size_t)toindex]; 196 if (top->selfpc == selfpc) { 197 /* 198 * arc at front of chain; usual case. 199 */ 200 top->count++; 201 goto done; 202 } 203 /* 204 * have to go looking down chain for it. 205 * top points to what we are looking at, 206 * prevtop points to previous top. 207 * we know it is not at the head of the chain. 208 */ 209 for (; /* goto done */; ) { 210 if (top->link == 0) { 211 /* 212 * top is end of the chain and none of the chain 213 * had top->selfpc == selfpc. 214 * so we allocate a new tostruct 215 * and link it to the head of the chain. 216 */ 217 toindex = ++p->tos[0].link; 218 if (toindex >= p->tolimit) 219 goto overflow; 220 221 top = &p->tos[(size_t)toindex]; 222 top->selfpc = selfpc; 223 top->count = 1; 224 top->link = *frompcindex; 225 *frompcindex = (u_short)toindex; 226 goto done; 227 } 228 /* 229 * otherwise, check the next arc on the chain. 230 */ 231 prevtop = top; 232 top = &p->tos[top->link]; 233 if (top->selfpc == selfpc) { 234 /* 235 * there it is. 236 * increment its count 237 * move it to the head of the chain. 238 */ 239 top->count++; 240 toindex = prevtop->link; 241 prevtop->link = top->link; 242 top->link = *frompcindex; 243 *frompcindex = (u_short)toindex; 244 goto done; 245 } 246 247 } 248 done: 249 p->state = GMON_PROF_ON; 250 #ifdef _KERNEL 251 MCOUNT_EXIT; 252 #endif 253 return; 254 overflow: 255 p->state = GMON_PROF_ERROR; 256 #ifdef _KERNEL 257 MCOUNT_EXIT; 258 #endif 259 return; 260 } 261 262 #ifdef MCOUNT 263 /* 264 * Actual definition of mcount function. Defined in <machine/profile.h>, 265 * which is included by <sys/gmon.h>. 266 */ 267 MCOUNT 268 #endif 269 270 #endif /* (!_KERNEL || GPROF) && !_STANDALONE */ 271