common/lib/libc/gmon/mcount.c

   1 /*      $NetBSD: mcount.c,v 1.10 2012/03/20 16:21:41 matt 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 1.10 2012/03/20 16:21:41 matt 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(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; may be static, inline, etc */
 131 _MCOUNT_DECL(u_long frompc, u_long 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 */