xref: /titanic_41/usr/src/cmd/sgs/libelf/common/newphdr.c (revision 7257d1b4d25bfac0c802847390e98a464fd787ac)
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 <memory.h>
34 #include <errno.h>
35 #include "decl.h"
36 #include "msg.h"
37 
38 /*
39  * This module is compiled twice, the second time having
40  * -D_ELF64 defined.  The following set of macros, along
41  * with machelf.h, represent the differences between the
42  * two compilations.  Be careful *not* to add any class-
43  * dependent code (anything that has elf32 or elf64 in the
44  * name) to this code without hiding it behind a switch-
45  * able macro like these.
46  */
47 #if	defined(_ELF64)
48 
49 #define	ELFCLASS	ELFCLASS64
50 #define	elf_newphdr	elf64_newphdr
51 #define	elf_getehdr	elf64_getehdr
52 #define	_elf_msize	_elf64_msize
53 #define	elf_fsize	elf64_fsize
54 
55 #else	/* else ELF32 */
56 
57 #define	ELFCLASS	ELFCLASS32
58 #define	elf_newphdr	elf32_newphdr
59 #define	elf_getehdr	elf32_getehdr
60 #define	_elf_msize	_elf32_msize
61 #define	elf_fsize	elf32_fsize
62 
63 #endif /* ELF64 */
64 
65 
66 Phdr *
elf_newphdr(Elf * elf,size_t count)67 elf_newphdr(Elf * elf, size_t count)
68 {
69 	Elf_Void *	ph;
70 	size_t		sz;
71 	Phdr *		rc;
72 	unsigned	work;
73 
74 	if (elf == 0)
75 		return (0);
76 	ELFRLOCK(elf)
77 	if (elf->ed_class != ELFCLASS) {
78 		_elf_seterr(EREQ_CLASS, 0);
79 		ELFUNLOCK(elf)
80 		return (0);
81 	}
82 	ELFUNLOCK(elf)
83 	if (elf_getehdr(elf) == 0) {		/* this cooks if necessary */
84 		_elf_seterr(ESEQ_EHDR, 0);
85 		return (0);
86 	}
87 
88 	/*
89 	 * Free the existing header if appropriate.  This could reuse
90 	 * existing space if big enough, but that's unlikely, benefit
91 	 * would be negligible, and code would be more complicated.
92 	 */
93 
94 	ELFWLOCK(elf)
95 	if (elf->ed_myflags & EDF_PHALLOC) {
96 		elf->ed_myflags &= ~EDF_PHALLOC;
97 		rc = elf->ed_phdr;
98 		free(rc);
99 	}
100 
101 	/*
102 	 * Delete the header if count is zero.
103 	 */
104 
105 	ELFACCESSDATA(work, _elf_work)
106 	if ((sz = count * _elf_msize(ELF_T_PHDR, work)) == 0) {
107 		elf->ed_phflags &= ~ELF_F_DIRTY;
108 		elf->ed_phdr = 0;
109 		((Ehdr*)elf->ed_ehdr)->e_phnum = 0;
110 		((Ehdr*)elf->ed_ehdr)->e_phentsize = 0;
111 		elf->ed_phdrsz = 0;
112 		ELFUNLOCK(elf)
113 		return (0);
114 	}
115 
116 	if ((ph = malloc(sz)) == 0) {
117 		_elf_seterr(EMEM_PHDR, errno);
118 		elf->ed_phflags &= ~ELF_F_DIRTY;
119 		elf->ed_phdr = 0;
120 		((Ehdr*)elf->ed_ehdr)->e_phnum = 0;
121 		((Ehdr*)elf->ed_ehdr)->e_phentsize = 0;
122 		elf->ed_phdrsz = 0;
123 		ELFUNLOCK(elf)
124 		return (0);
125 	}
126 
127 	elf->ed_myflags |= EDF_PHALLOC;
128 	(void) memset(ph, 0, sz);
129 	elf->ed_phflags |= ELF_F_DIRTY;
130 	/* LINTED */
131 	((Ehdr*)elf->ed_ehdr)->e_phnum = (Half)count;
132 	((Ehdr*)elf->ed_ehdr)->e_phentsize
133 	    /* LINTED */
134 	    = (Half)elf_fsize(ELF_T_PHDR, 1, work);
135 	elf->ed_phdrsz = sz;
136 	elf->ed_phdr = rc = ph;
137 
138 	ELFUNLOCK(elf)
139 	return (rc);
140 }
141