xref: /illumos-gate/usr/src/cmd/sgs/libelf/common/newdata.c (revision 8119dad84d6416f13557b0ba8e2aaf9064cbcfd3)
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 /*
23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*	Copyright (c) 1988 AT&T	*/
28 /*	  All Rights Reserved  	*/
29 
30 #include "libelf.h"
31 #include "decl.h"
32 #include "msg.h"
33 
34 
35 Elf_Data *
36 elf_newdata(Elf_Scn * s)
37 {
38 	Dnode *		d;
39 	Elf_Data *	rc;
40 	Elf *		elf;
41 	unsigned	work;
42 
43 	if (s == 0)
44 		return (0);
45 	elf = s->s_elf;
46 	READLOCKS(elf, s)
47 	if (s->s_index == SHN_UNDEF) {
48 		_elf_seterr(EREQ_SCNNULL, 0);
49 		READUNLOCKS(elf, s)
50 		return (0);
51 	}
52 
53 	if ((s->s_myflags & SF_READY) == 0) {
54 		UPGRADELOCKS(elf, s)
55 		/*
56 		 * re-confirm that another 'thread' hasn't come along
57 		 * and cooked this section while the locks were
58 		 * obtained.
59 		 */
60 		if ((s->s_myflags & SF_READY) == 0)
61 			(void) _elf_cookscn(s);
62 		DOWNGRADELOCKS(elf, s)
63 	}
64 
65 	/*
66 	 * If this is the first new node, use the one allocated
67 	 * in the scn itself.  Update data buffer in both cases.
68 	 */
69 	ELFACCESSDATA(work, _elf_work)
70 	if (s->s_hdnode == 0) {
71 		s->s_dnode.db_uflags |= ELF_F_DIRTY;
72 		s->s_dnode.db_myflags |= DBF_READY;
73 		s->s_hdnode = &s->s_dnode;
74 		s->s_tlnode = &s->s_dnode;
75 		s->s_dnode.db_scn = s;
76 		s->s_dnode.db_data.d_version = work;
77 		rc = &s->s_dnode.db_data;
78 		READUNLOCKS(elf, s)
79 		return (rc);
80 	}
81 	if ((d = _elf_dnode()) == 0) {
82 		READUNLOCKS(elf, s)
83 		return (0);
84 	}
85 	d->db_data.d_version = work;
86 	d->db_scn = s;
87 	d->db_uflags |= ELF_F_DIRTY;
88 	d->db_myflags |= DBF_READY;
89 	s->s_tlnode->db_next = d;
90 	s->s_tlnode = d;
91 	rc = &d->db_data;
92 	READUNLOCKS(elf, s)
93 	return (rc);
94 }
95