xref: /freebsd/contrib/elftoolchain/libelf/libelf_extended.c (revision a831d7d1c538b93ffec095657d9a6e6e778db195)
1 /*-
2  * Copyright (c) 2006,2008 Joseph Koshy
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 
29 #include <assert.h>
30 #include <libelf.h>
31 
32 #include "_libelf.h"
33 
34 ELFTC_VCSID("$Id: libelf_extended.c 3005 2014-03-22 07:43:25Z jkoshy $");
35 
36 /*
37  * Retrieve section #0, allocating a new section if needed.
38  */
39 static Elf_Scn *
40 _libelf_getscn0(Elf *e)
41 {
42 	Elf_Scn *s;
43 
44 	if ((s = STAILQ_FIRST(&e->e_u.e_elf.e_scn)) != NULL)
45 		return (s);
46 
47 	return (_libelf_allocate_scn(e, (size_t) SHN_UNDEF));
48 }
49 
50 int
51 _libelf_setshnum(Elf *e, void *eh, int ec, size_t shnum)
52 {
53 	Elf_Scn *scn;
54 
55 	if (shnum >= SHN_LORESERVE) {
56 		if ((scn = _libelf_getscn0(e)) == NULL)
57 			return (0);
58 
59 		assert(scn->s_ndx == SHN_UNDEF);
60 
61 		if (ec == ELFCLASS32)
62 			scn->s_shdr.s_shdr32.sh_size = shnum;
63 		else
64 			scn->s_shdr.s_shdr64.sh_size = shnum;
65 
66 		(void) elf_flagshdr(scn, ELF_C_SET, ELF_F_DIRTY);
67 
68 		shnum = 0;
69 	}
70 
71 	if (ec == ELFCLASS32)
72 		((Elf32_Ehdr *) eh)->e_shnum = shnum & 0xFFFFU;
73 	else
74 		((Elf64_Ehdr *) eh)->e_shnum = shnum & 0xFFFFU;
75 
76 
77 	return (1);
78 }
79 
80 int
81 _libelf_setshstrndx(Elf *e, void *eh, int ec, size_t shstrndx)
82 {
83 	Elf_Scn *scn;
84 
85 	if (shstrndx >= SHN_LORESERVE) {
86 		if ((scn = _libelf_getscn0(e)) == NULL)
87 			return (0);
88 
89 		assert(scn->s_ndx == SHN_UNDEF);
90 
91 		if (ec == ELFCLASS32)
92 			scn->s_shdr.s_shdr32.sh_link = shstrndx;
93 		else
94 			scn->s_shdr.s_shdr64.sh_link = shstrndx;
95 
96 		(void) elf_flagshdr(scn, ELF_C_SET, ELF_F_DIRTY);
97 
98 		shstrndx = SHN_XINDEX;
99 	}
100 
101 	if (ec == ELFCLASS32)
102 		((Elf32_Ehdr *) eh)->e_shstrndx = shstrndx & 0xFFFFU;
103 	else
104 		((Elf64_Ehdr *) eh)->e_shstrndx = shstrndx & 0xFFFFU;
105 
106 	return (1);
107 }
108 
109 int
110 _libelf_setphnum(Elf *e, void *eh, int ec, size_t phnum)
111 {
112 	Elf_Scn *scn;
113 
114 	if (phnum >= PN_XNUM) {
115 		if ((scn = _libelf_getscn0(e)) == NULL)
116 			return (0);
117 
118 		assert(scn->s_ndx == SHN_UNDEF);
119 
120 		if (ec == ELFCLASS32)
121 			scn->s_shdr.s_shdr32.sh_info = phnum;
122 		else
123 			scn->s_shdr.s_shdr64.sh_info = phnum;
124 
125 		(void) elf_flagshdr(scn, ELF_C_SET, ELF_F_DIRTY);
126 
127 		phnum = PN_XNUM;
128 	}
129 
130 	if (ec == ELFCLASS32)
131 		((Elf32_Ehdr *) eh)->e_phnum = phnum & 0xFFFFU;
132 	else
133 		((Elf64_Ehdr *) eh)->e_phnum = phnum & 0xFFFFU;
134 
135 	return (1);
136 }
137