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 <sys/types.h>
 30  
 31  #include <libelf.h>
 32  
 33  #include "_libelf.h"
 34  
 35  ELFTC_VCSID("$Id$");
 36  
 37  struct align {
 38  	unsigned int a32;
 39  	unsigned int a64;
 40  };
 41  
 42  #ifdef	__GNUC__
 43  #define	MALIGN(N)	{					\
 44  		.a32 = __alignof__(Elf32_##N),			\
 45  		.a64 = __alignof__(Elf64_##N)			\
 46  	}
 47  #define	MALIGN64(V)	  {					\
 48  		.a32 = 0,					\
 49  		.a64 = __alignof__(Elf64_##V)			\
 50  	}
 51  #define	MALIGN_WORD()	{					\
 52  		.a32 = __alignof__(int32_t),			\
 53  		.a64 = __alignof__(int64_t)			\
 54  	    }
 55  #else
 56  #error	Need the __alignof__ builtin.
 57  #endif
 58  #define	UNSUPPORTED()	{					\
 59  		.a32 = 0,					\
 60  		.a64 = 0					\
 61  	}
 62  
 63  static struct align malign[ELF_T_NUM] = {
 64  	[ELF_T_ADDR]	= MALIGN(Addr),
 65  	[ELF_T_BYTE]	= { .a32 = 1, .a64 = 1 },
 66  	[ELF_T_CAP]	= MALIGN(Cap),
 67  	[ELF_T_DYN]	= MALIGN(Dyn),
 68  	[ELF_T_EHDR]	= MALIGN(Ehdr),
 69  	[ELF_T_HALF]	= MALIGN(Half),
 70  	[ELF_T_LWORD]	= MALIGN(Lword),
 71  	[ELF_T_MOVE]	= MALIGN(Move),
 72  	[ELF_T_MOVEP] 	= UNSUPPORTED(),
 73  	[ELF_T_NOTE]	= MALIGN(Nhdr),
 74  	[ELF_T_OFF]	= MALIGN(Off),
 75  	[ELF_T_PHDR]	= MALIGN(Phdr),
 76  	[ELF_T_REL]	= MALIGN(Rel),
 77  	[ELF_T_RELA]	= MALIGN(Rela),
 78  	[ELF_T_SHDR]	= MALIGN(Shdr),
 79  	[ELF_T_SWORD]	= MALIGN(Sword),
 80  	[ELF_T_SXWORD]	= MALIGN64(Sxword),
 81  	[ELF_T_SYM]	= MALIGN(Sym),
 82  	[ELF_T_SYMINFO]	= MALIGN(Syminfo),
 83  	[ELF_T_VDEF]	= MALIGN(Verdef),
 84  	[ELF_T_VNEED]	= MALIGN(Verneed),
 85  	[ELF_T_WORD]	= MALIGN(Word),
 86  	[ELF_T_XWORD]	= MALIGN64(Xword),
 87  	[ELF_T_GNUHASH] = MALIGN_WORD()
 88  };
 89  
 90  unsigned int
 91  _libelf_malign(Elf_Type t, int elfclass)
 92  {
 93  	if (t >= ELF_T_NUM || (int) t < 0)
 94  		return (0);
 95  
 96  	return (elfclass == ELFCLASS32 ? malign[t].a32 :
 97  	    malign[t].a64);
 98  }
 99  
100  #define	FALIGN(A32,A64)	{ .a32 = (A32), .a64 = (A64) }
101  
102  static struct align falign[ELF_T_NUM] = {
103  	[ELF_T_ADDR]	= FALIGN(4,8),
104  	[ELF_T_BYTE]	= FALIGN(1,1),
105  	[ELF_T_CAP]	= FALIGN(4,8),
106  	[ELF_T_DYN]	= FALIGN(4,8),
107  	[ELF_T_EHDR]	= FALIGN(4,8),
108  	[ELF_T_HALF]	= FALIGN(2,2),
109  	[ELF_T_LWORD]	= FALIGN(8,8),
110  	[ELF_T_MOVE]	= FALIGN(8,8),
111  	[ELF_T_MOVEP] 	= UNSUPPORTED(),
112  	[ELF_T_NOTE]	= FALIGN(4,4),
113  	[ELF_T_OFF]	= FALIGN(4,8),
114  	[ELF_T_PHDR]	= FALIGN(4,8),
115  	[ELF_T_REL]	= FALIGN(4,8),
116  	[ELF_T_RELA]	= FALIGN(4,8),
117  	[ELF_T_SHDR]	= FALIGN(4,8),
118  	[ELF_T_SWORD]	= FALIGN(4,4),
119  	[ELF_T_SXWORD]	= FALIGN(0,8),
120  	[ELF_T_SYM]	= FALIGN(4,8),
121  	[ELF_T_SYMINFO]	= FALIGN(2,2),
122  	[ELF_T_VDEF]	= FALIGN(4,4),
123  	[ELF_T_VNEED]	= FALIGN(4,4),
124  	[ELF_T_WORD]	= FALIGN(4,4),
125  	[ELF_T_XWORD]	= FALIGN(0,8),
126  	[ELF_T_GNUHASH] = FALIGN(4,8)
127  };
128  
129  unsigned int
130  _libelf_falign(Elf_Type t, int elfclass)
131  {
132  	if (t >= ELF_T_NUM || (int) t < 0)
133  		return (0);
134  
135  	return (elfclass == ELFCLASS32 ? falign[t].a32 :
136  	    falign[t].a64);
137  }