xref: /illumos-gate/usr/src/cmd/sgs/prof/common/lookup.c (revision 7c478bd9)
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 *
nllookup(mod_info_t * module,Address address,Address * nxtsym_val)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 *
locate(Address * pclist,size_t nelem,Address keypc)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 }
123