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 (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21/*
22 * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
23 * Use is subject to license terms.
24 */
25
26#include "misc.h"
27
28#define	UMEM_OBJNAME "libumem.so.1"
29
30int umem_debug_level = 0;
31int umem_is_standalone = 0;
32
33/*ARGSUSED*/
34int
35umem_debug(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
36{
37	umem_debug_level ^= 1;
38
39	mdb_printf("umem: debugging is now %s\n",
40	    umem_debug_level ? "on" : "off");
41
42	return (DCMD_OK);
43}
44
45/*
46 * To further confuse the issue, this dmod can run against either
47 * libumem.so.1 *or* the libstandumem.so linked into kmdb(1M).  To figure
48 * out which one we are working against, we look up "umem_alloc" in both
49 * libumem.so and the executable.
50 *
51 * A further wrinkle is that libumem.so may not yet be loaded into the
52 * process' address space.  That can lead to either the lookup failing, or
53 * being unable to read from the data segment.  We treat either case as
54 * an error.
55 */
56int
57umem_set_standalone(void)
58{
59	GElf_Sym sym;
60	int ready;
61
62	if (mdb_lookup_by_obj(UMEM_OBJNAME, "umem_alloc", &sym) == 0)
63		umem_is_standalone = 0;
64	else if (mdb_lookup_by_obj(MDB_OBJ_EXEC, "umem_alloc", &sym) == 0)
65		umem_is_standalone = 1;
66	else
67		return (-1);
68
69	/*
70	 * now that we know where things should be, make sure we can actually
71	 * read things out.
72	 */
73	if (umem_readvar(&ready, "umem_ready") == -1)
74		return (-1);
75	return (0);
76}
77
78ssize_t
79umem_lookup_by_name(const char *name, GElf_Sym *sym)
80{
81	return (mdb_lookup_by_obj((umem_is_standalone ? MDB_OBJ_EXEC :
82	    UMEM_OBJNAME), name, sym));
83}
84
85/* This is like mdb_readvar, only for libumem.so's symbols */
86ssize_t
87umem_readvar(void *buf, const char *name)
88{
89	GElf_Sym sym;
90
91	if (umem_lookup_by_name(name, &sym))
92		return (-1);
93
94	if (mdb_vread(buf, sym.st_size, (uintptr_t)sym.st_value)
95	    == sym.st_size)
96		return ((ssize_t)sym.st_size);
97
98	return (-1);
99}
100
101int
102is_umem_sym(const char *sym, const char *prefix)
103{
104	char *tick_p = strrchr(sym, '`');
105
106	return (strncmp(sym, "libumem", 7) == 0 && tick_p != NULL &&
107	    strncmp(tick_p + 1, prefix, strlen(prefix)) == 0);
108}
109