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/types.h>
28
29#include <libelf.h>
30
31#include "_libelf.h"
32
33ELFTC_VCSID("$Id: libelf_align.c,v 1.1 2019/02/01 05:27:38 jsg Exp $");
34
35struct align {
36	unsigned int a32;
37	unsigned int a64;
38};
39
40#ifdef	__GNUC__
41#define	MALIGN(N)	{					\
42		.a32 = __alignof__(Elf32_##N),			\
43		.a64 = __alignof__(Elf64_##N)			\
44	}
45#define	MALIGN64(V)	  {					\
46		.a32 = 0,					\
47		.a64 = __alignof__(Elf64_##V)			\
48	}
49#define	MALIGN_WORD()	{					\
50		.a32 = __alignof__(int32_t),			\
51		.a64 = __alignof__(int64_t)			\
52	    }
53#else
54#error	Need the __alignof__ builtin.
55#endif
56#define	UNSUPPORTED()	{					\
57		.a32 = 0,					\
58		.a64 = 0					\
59	}
60
61static struct align malign[ELF_T_NUM] = {
62	[ELF_T_ADDR]	= MALIGN(Addr),
63	[ELF_T_BYTE]	= { .a32 = 1, .a64 = 1 },
64	[ELF_T_CAP]	= MALIGN(Cap),
65	[ELF_T_DYN]	= MALIGN(Dyn),
66	[ELF_T_EHDR]	= MALIGN(Ehdr),
67	[ELF_T_HALF]	= MALIGN(Half),
68	[ELF_T_LWORD]	= MALIGN(Lword),
69	[ELF_T_MOVE]	= MALIGN(Move),
70	[ELF_T_MOVEP] 	= UNSUPPORTED(),
71	[ELF_T_NOTE]	= MALIGN(Nhdr),
72	[ELF_T_OFF]	= MALIGN(Off),
73	[ELF_T_PHDR]	= MALIGN(Phdr),
74	[ELF_T_REL]	= MALIGN(Rel),
75	[ELF_T_RELA]	= MALIGN(Rela),
76	[ELF_T_SHDR]	= MALIGN(Shdr),
77	[ELF_T_SWORD]	= MALIGN(Sword),
78	[ELF_T_SXWORD]	= MALIGN64(Sxword),
79	[ELF_T_SYM]	= MALIGN(Sym),
80	[ELF_T_SYMINFO]	= MALIGN(Syminfo),
81	[ELF_T_VDEF]	= MALIGN(Verdef),
82	[ELF_T_VNEED]	= MALIGN(Verneed),
83	[ELF_T_WORD]	= MALIGN(Word),
84	[ELF_T_XWORD]	= MALIGN64(Xword),
85	[ELF_T_GNUHASH] = MALIGN_WORD()
86};
87
88unsigned int
89_libelf_malign(Elf_Type t, int elfclass)
90{
91	if (t >= ELF_T_NUM || (int) t < 0)
92		return (0);
93
94	return (elfclass == ELFCLASS32 ? malign[t].a32 :
95	    malign[t].a64);
96}
97
98#define	FALIGN(A32,A64)	{ .a32 = (A32), .a64 = (A64) }
99
100static struct align falign[ELF_T_NUM] = {
101	[ELF_T_ADDR]	= FALIGN(4,8),
102	[ELF_T_BYTE]	= FALIGN(1,1),
103	[ELF_T_CAP]	= FALIGN(4,8),
104	[ELF_T_DYN]	= FALIGN(4,8),
105	[ELF_T_EHDR]	= FALIGN(4,8),
106	[ELF_T_HALF]	= FALIGN(2,2),
107	[ELF_T_LWORD]	= FALIGN(8,8),
108	[ELF_T_MOVE]	= FALIGN(8,8),
109	[ELF_T_MOVEP] 	= UNSUPPORTED(),
110	[ELF_T_NOTE]	= FALIGN(4,4),
111	[ELF_T_OFF]	= FALIGN(4,8),
112	[ELF_T_PHDR]	= FALIGN(4,8),
113	[ELF_T_REL]	= FALIGN(4,8),
114	[ELF_T_RELA]	= FALIGN(4,8),
115	[ELF_T_SHDR]	= FALIGN(4,8),
116	[ELF_T_SWORD]	= FALIGN(4,4),
117	[ELF_T_SXWORD]	= FALIGN(0,8),
118	[ELF_T_SYM]	= FALIGN(4,8),
119	[ELF_T_SYMINFO]	= FALIGN(2,2),
120	[ELF_T_VDEF]	= FALIGN(4,4),
121	[ELF_T_VNEED]	= FALIGN(4,4),
122	[ELF_T_WORD]	= FALIGN(4,4),
123	[ELF_T_XWORD]	= FALIGN(0,8),
124	[ELF_T_GNUHASH] = FALIGN(4,8)
125};
126
127unsigned int
128_libelf_falign(Elf_Type t, int elfclass)
129{
130	if (t >= ELF_T_NUM || (int) t < 0)
131		return (0);
132
133	return (elfclass == ELFCLASS32 ? falign[t].a32 :
134	    falign[t].a64);
135}
136