xref: /titanic_41/usr/src/cmd/sgs/libelf/common/newehdr.c (revision 257873cfc1dd3337766407f80397db60a56f2f5a)
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 #pragma ident	"%Z%%M%	%I%	%E% SMI"
31 
32 #include <stdlib.h>
33 #include <errno.h>
34 #include "decl.h"
35 #include "msg.h"
36 
37 /*
38  * This module is compiled twice, the second time having
39  * -D_ELF64 defined.  The following set of macros, along
40  * with machelf.h, represent the differences between the
41  * two compilations.  Be careful *not* to add any class-
42  * dependent code (anything that has elf32 or elf64 in the
43  * name) to this code without hiding it behind a switch-
44  * able macro like these.
45  */
46 #if	defined(_ELF64)
47 
48 #define	ELFCLASS		ELFCLASS64
49 #define	_elf_ehdr_init		_elf64_ehdr_init
50 #define	elf_newehdr		elf64_newehdr
51 #define	getehdr			elf64_getehdr
52 
53 #else	/* else ELF32 */
54 
55 #define	ELFCLASS		ELFCLASS32
56 #define	_elf_ehdr_init		_elf32_ehdr_init
57 #define	elf_newehdr		elf32_newehdr
58 #define	getehdr			elf32_getehdr
59 
60 #endif	/* ELF64 */
61 
62 
63 Ehdr *
64 elf_newehdr(Elf * elf)
65 {
66 	Ehdr	*eh;
67 
68 	if (elf == 0)
69 		return (0);
70 
71 	/*
72 	 * If reading file, return its hdr
73 	 */
74 
75 	ELFWLOCK(elf)
76 	if (elf->ed_myflags & EDF_READ) {
77 		ELFUNLOCK(elf)
78 		if ((eh = (Ehdr *)getehdr(elf)) != 0) {
79 			ELFWLOCK(elf)
80 			elf->ed_ehflags |= ELF_F_DIRTY;
81 			ELFUNLOCK(elf)
82 		}
83 		return (eh);
84 	}
85 
86 	/*
87 	 * Writing file
88 	 */
89 
90 	if (elf->ed_class == ELFCLASSNONE)
91 		elf->ed_class = ELFCLASS;
92 	else if (elf->ed_class != ELFCLASS) {
93 		_elf_seterr(EREQ_CLASS, 0);
94 		ELFUNLOCK(elf)
95 		return (0);
96 	}
97 	ELFUNLOCK(elf);
98 	if ((eh = (Ehdr *)getehdr(elf)) != 0) {	/* this cooks if necessary */
99 		ELFWLOCK(elf)
100 		elf->ed_ehflags |= ELF_F_DIRTY;
101 		ELFUNLOCK(elf)
102 		return (eh);
103 	}
104 	ELFWLOCK(elf)
105 
106 	if ((eh = (Ehdr *)malloc(sizeof (Ehdr))) == 0) {
107 		_elf_seterr(EMEM_EHDR, errno);
108 		ELFUNLOCK(elf)
109 		return (0);
110 	}
111 	*eh = _elf_ehdr_init;
112 	elf->ed_myflags |= EDF_EHALLOC;
113 	elf->ed_ehflags |= ELF_F_DIRTY;
114 	elf->ed_ehdr = eh;
115 	ELFUNLOCK(elf)
116 	return (eh);
117 }
118