1 /*-
2 * Copyright (c) 2006 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 __FBSDID("$FreeBSD$");
29
30 #include <assert.h>
31 #include <libelf.h>
32
33 #include "_libelf.h"
34
35 /*
36 * Retrieve section #0, allocating a new section if needed.
37 */
38 static Elf_Scn *
_libelf_getscn0(Elf * e)39 _libelf_getscn0(Elf *e)
40 {
41 Elf_Scn *s;
42
43 if ((s = STAILQ_FIRST(&e->e_u.e_elf.e_scn)) != NULL)
44 return (s);
45
46 return (_libelf_allocate_scn(e, (size_t) SHN_UNDEF));
47 }
48
49 int
_libelf_setshnum(Elf * e,void * eh,int ec,size_t shnum)50 _libelf_setshnum(Elf *e, void *eh, int ec, size_t shnum)
51 {
52 Elf_Scn *scn;
53
54 if (shnum >= SHN_LORESERVE) {
55 if ((scn = _libelf_getscn0(e)) == NULL)
56 return (0);
57
58 assert(scn->s_ndx == SHN_UNDEF);
59
60 if (ec == ELFCLASS32)
61 scn->s_shdr.s_shdr32.sh_size = shnum;
62 else
63 scn->s_shdr.s_shdr64.sh_size = shnum;
64
65 (void) elf_flagshdr(scn, ELF_C_SET, ELF_F_DIRTY);
66
67 shnum = 0;
68 }
69
70 if (ec == ELFCLASS32)
71 ((Elf32_Ehdr *) eh)->e_shnum = shnum;
72 else
73 ((Elf64_Ehdr *) eh)->e_shnum = shnum;
74
75
76 return (1);
77 }
78
79 int
_libelf_setshstrndx(Elf * e,void * eh,int ec,size_t shstrndx)80 _libelf_setshstrndx(Elf *e, void *eh, int ec, size_t shstrndx)
81 {
82 Elf_Scn *scn;
83
84 if (shstrndx >= SHN_LORESERVE) {
85 if ((scn = _libelf_getscn0(e)) == NULL)
86 return (0);
87
88 assert(scn->s_ndx == SHN_UNDEF);
89
90 if (ec == ELFCLASS32)
91 scn->s_shdr.s_shdr32.sh_link = shstrndx;
92 else
93 scn->s_shdr.s_shdr64.sh_link = shstrndx;
94
95 (void) elf_flagshdr(scn, ELF_C_SET, ELF_F_DIRTY);
96
97 shstrndx = SHN_XINDEX;
98 }
99
100 if (ec == ELFCLASS32)
101 ((Elf32_Ehdr *) eh)->e_shstrndx = shstrndx;
102 else
103 ((Elf64_Ehdr *) eh)->e_shstrndx = shstrndx;
104
105 return (1);
106 }
107
108 int
_libelf_setphnum(Elf * e,void * eh,int ec,size_t phnum)109 _libelf_setphnum(Elf *e, void *eh, int ec, size_t phnum)
110 {
111 Elf_Scn *scn;
112
113 if (phnum >= PN_XNUM) {
114 if ((scn = _libelf_getscn0(e)) == NULL)
115 return (0);
116
117 assert(scn->s_ndx == SHN_UNDEF);
118
119 if (ec == ELFCLASS32)
120 scn->s_shdr.s_shdr32.sh_info = phnum;
121 else
122 scn->s_shdr.s_shdr64.sh_info = phnum;
123
124 (void) elf_flagshdr(scn, ELF_C_SET, ELF_F_DIRTY);
125
126 phnum = PN_XNUM;
127 }
128
129 if (ec == ELFCLASS32)
130 ((Elf32_Ehdr *) eh)->e_phnum = phnum;
131 else
132 ((Elf64_Ehdr *) eh)->e_phnum = phnum;
133
134 return (1);
135 }
136
137