usr/src/cmd/sgs/prof/common/lookup.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 /*
  23  * Copyright (c) 1998 by Sun Microsystems, Inc.
  24  * All rights reserved.
  25  */
  26 #pragma ident   "%Z%%M% %I%     %E% SMI"
  27
  28 /*
  29  * Search routines for processing new-style mon.out files.
  30  */
  31
  32 #include "profv.h"
  33
  34 /*
  35  * Look up an address in a sorted-by-address namelist; this deals with
  36  * misses by mapping them to the next lower entry point.
  37  */
  38 nltype *
  39 nllookup(mod_info_t *module, Address address, Address *nxtsym_val)
  40 {
  41         size_t          low = 0, middle, high = module->nfuncs - 1;
  42         nltype          *nl = module->nl;
  43         Address         keyval;
  44
  45         /*
  46          * If this is the program executable in which we are looking up
  47          * a symbol, then the actual load address will be the same as the
  48          * address specified in the ELF file. For shared objects, the
  49          * load address may differ from what is specified in the file. In
  50          * this case, we may need to look for a different value altogether.
  51          */
  52         keyval = module->txt_origin + (address - module->load_base);
  53
  54         if (keyval < nl[low].value) {
  55                 if (nxtsym_val) {
  56                         *nxtsym_val = module->load_base +
  57                                         (nl[low].value - module->txt_origin);
  58                 }
  59                 return (NULL);
  60         }
  61
  62         if (keyval >= nl[high].value) {
  63                 if (nxtsym_val)
  64                         *nxtsym_val = module->load_end;
  65                 return (&nl[high]);
  66         }
  67
  68         while (low != high) {
  69                 middle = (high + low) >> 1;
  70
  71                 if ((nl[middle].value <= keyval) &&
  72                                         (nl[middle + 1].value > keyval)) {
  73                         if (nxtsym_val) {
  74                                 *nxtsym_val = module->load_base +
  75                                     (nl[middle + 1].value - module->txt_origin);
  76                         }
  77
  78                         return (&nl[middle]);
  79                 }
  80
  81                 if (nl[middle].value > keyval)
  82                         high = middle;
  83                 else
  84                         low = middle + 1;
  85         }
  86
  87         /* must never reach here! */
  88         return (NULL);
  89 }
  90
  91 /*
  92  * Look up a module's base address in a sorted list of pc-hits. Unlike
  93  * nllookup(), this deals with misses by mapping them to the next *higher*
  94  * pc-hit. This is so that we get into the module's first pc-hit rightaway,
  95  * even if the module's entry-point (load_base) itself is not a hit.
  96  */
  97 Address *
  98 locate(Address  *pclist, size_t nelem, Address keypc)
  99 {
 100         size_t  low = 0, middle, high = nelem - 1;
 101
 102         if (keypc <= pclist[low])
 103                 return (pclist);
 104
 105         if (keypc > pclist[high])
 106                 return (NULL);
 107
 108         while (low != high) {
 109                 middle = (high + low) >> 1;
 110
 111                 if ((pclist[middle] < keypc) && (pclist[middle + 1] >= keypc))
 112                         return (&pclist[middle + 1]);
 113
 114                 if (pclist[middle] >= keypc)
 115                         high = middle;
 116                 else
 117                         low = middle + 1;
 118         }
 119
 120         /* must never reach here! */
 121         return (NULL);
 122 }