mcount.c revision 1.12
1 /* $NetBSD: mcount.c,v 1.12 2016/01/11 01:57:12 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(_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 1.12 2016/01/11 01:57:12 christos Exp $"); 80 #endif 81 #endif 82 83 #include <sys/param.h> 84 #include <sys/gmon.h> 85 #include <sys/lock.h> 86 87 #ifndef _KERNEL 88 #include "reentrant.h" 89 #endif 90 91 #ifdef _REENTRANT 92 extern thread_key_t _gmonkey; 93 extern struct gmonparam _gmondummy; 94 struct gmonparam *_m_gmon_alloc(void); 95 #endif 96 97 #if defined(_KERNEL) && !defined(_RUMPKERNEL) && defined(MULTIPROCESSOR) 98 __cpu_simple_lock_t __mcount_lock; 99 #endif 100 101 #ifndef __LINT__ 102 _MCOUNT_DECL(u_long, u_long) 103 #ifdef _KERNEL 104 __attribute__((__no_instrument_function__)) 105 #endif 106 __used; 107 #endif 108 109 /* XXX: make these interfaces */ 110 #ifdef _RUMPKERNEL 111 #undef MCOUNT_ENTER 112 #define MCOUNT_ENTER 113 #undef MCOUNT_EXIT 114 #define MCOUNT_EXIT 115 #undef MCOUNT 116 #define MCOUNT 117 #endif 118 119 /* 120 * mcount is called on entry to each function compiled with the profiling 121 * switch set. _mcount(), which is declared in a machine-dependent way 122 * with _MCOUNT_DECL, does the actual work and is either inlined into a 123 * C routine or called by an assembly stub. In any case, this magic is 124 * taken care of by the MCOUNT definition in <machine/profile.h>. 125 * 126 * _mcount updates data structures that represent traversals of the 127 * program's call graph edges. frompc and selfpc are the return 128 * address and function address that represents the given call graph edge. 129 * 130 * Note: the original BSD code used the same variable (frompcindex) for 131 * both frompcindex and frompc. Any reasonable, modern compiler will 132 * perform this optimization. 133 */ 134 #ifndef __LINT__ 135 /* _mcount; may be static, inline, etc */ 136 _MCOUNT_DECL(u_long frompc, u_long selfpc) 137 { 138 u_short *frompcindex; 139 struct tostruct *top, *prevtop; 140 struct gmonparam *p; 141 long toindex; 142 #if defined(_KERNEL) && !defined(_RUMPKERNEL) 143 int s; 144 #endif 145 146 #if defined(_REENTRANT) && !defined(_KERNEL) 147 if (__isthreaded) { 148 p = thr_getspecific(_gmonkey); 149 if (p == NULL) { 150 /* Prevent recursive calls while allocating */ 151 thr_setspecific(_gmonkey, &_gmondummy); 152 p = _m_gmon_alloc(); 153 } 154 } else 155 #endif 156 p = &_gmonparam; 157 /* 158 * check that we are profiling 159 * and that we aren't recursively invoked. 160 */ 161 if (p->state != GMON_PROF_ON) 162 return; 163 #if defined(_KERNEL) && !defined(_RUMPKERNEL) 164 MCOUNT_ENTER; 165 #ifdef MULTIPROCESSOR 166 __cpu_simple_lock(&__mcount_lock); 167 __insn_barrier(); 168 #endif 169 #endif 170 p->state = GMON_PROF_BUSY; 171 /* 172 * check that frompcindex is a reasonable pc value. 173 * for example: signal catchers get called from the stack, 174 * not from text space. too bad. 175 */ 176 frompc -= p->lowpc; 177 if (frompc > p->textsize) 178 goto done; 179 180 #if (HASHFRACTION & (HASHFRACTION - 1)) == 0 181 if (p->hashfraction == HASHFRACTION) 182 frompcindex = 183 &p->froms[ 184 (size_t)(frompc / (HASHFRACTION * sizeof(*p->froms)))]; 185 else 186 #endif 187 frompcindex = 188 &p->froms[ 189 (size_t)(frompc / (p->hashfraction * sizeof(*p->froms)))]; 190 toindex = *frompcindex; 191 if (toindex == 0) { 192 /* 193 * first time traversing this arc 194 */ 195 toindex = ++p->tos[0].link; 196 if (toindex >= p->tolimit) 197 /* halt further profiling */ 198 goto overflow; 199 200 *frompcindex = (u_short)toindex; 201 top = &p->tos[(size_t)toindex]; 202 top->selfpc = selfpc; 203 top->count = 1; 204 top->link = 0; 205 goto done; 206 } 207 top = &p->tos[(size_t)toindex]; 208 if (top->selfpc == selfpc) { 209 /* 210 * arc at front of chain; usual case. 211 */ 212 top->count++; 213 goto done; 214 } 215 /* 216 * have to go looking down chain for it. 217 * top points to what we are looking at, 218 * prevtop points to previous top. 219 * we know it is not at the head of the chain. 220 */ 221 for (; /* goto done */; ) { 222 if (top->link == 0) { 223 /* 224 * top is end of the chain and none of the chain 225 * had top->selfpc == selfpc. 226 * so we allocate a new tostruct 227 * and link it to the head of the chain. 228 */ 229 toindex = ++p->tos[0].link; 230 if (toindex >= p->tolimit) 231 goto overflow; 232 233 top = &p->tos[(size_t)toindex]; 234 top->selfpc = selfpc; 235 top->count = 1; 236 top->link = *frompcindex; 237 *frompcindex = (u_short)toindex; 238 goto done; 239 } 240 /* 241 * otherwise, check the next arc on the chain. 242 */ 243 prevtop = top; 244 top = &p->tos[top->link]; 245 if (top->selfpc == selfpc) { 246 /* 247 * there it is. 248 * increment its count 249 * move it to the head of the chain. 250 */ 251 top->count++; 252 toindex = prevtop->link; 253 prevtop->link = top->link; 254 top->link = *frompcindex; 255 *frompcindex = (u_short)toindex; 256 goto done; 257 } 258 } 259 done: 260 p->state = GMON_PROF_ON; 261 #if defined(_KERNEL) && !defined(_RUMPKERNEL) 262 #ifdef MULTIPROCESSOR 263 __insn_barrier(); 264 __cpu_simple_unlock(&__mcount_lock); 265 #endif 266 MCOUNT_EXIT; 267 #endif 268 return; 269 270 overflow: 271 p->state = GMON_PROF_ERROR; 272 #if defined(_KERNEL) && !defined(_RUMPKERNEL) 273 #ifdef MULTIPROCESSOR 274 __insn_barrier(); 275 __cpu_simple_unlock(&__mcount_lock); 276 #endif 277 MCOUNT_EXIT; 278 #endif 279 return; 280 } 281 #endif 282 283 #ifdef MCOUNT 284 /* 285 * Actual definition of mcount function. Defined in <machine/profile.h>, 286 * which is included by <sys/gmon.h>. 287 */ 288 MCOUNT 289 #endif 290 291 #endif /* (!_KERNEL || GPROF) && !_STANDALONE */ 292
Indexes created Mon Sep 22 05:09:51 GMT 2025