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1 /* Transformation functions for ELF data types.
2    Copyright (C) 1998,1999,2000,2002,2004,2005,2006,2007 Red Hat, Inc.
3    This file is part of Red Hat elfutils.
4    Written by Ulrich Drepper <drepper@redhat.com>, 1998.
5 
6    Red Hat elfutils is free software; you can redistribute it and/or modify
7    it under the terms of the GNU General Public License as published by the
8    Free Software Foundation; version 2 of the License.
9 
10    Red Hat elfutils is distributed in the hope that it will be useful, but
11    WITHOUT ANY WARRANTY; without even the implied warranty of
12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13    General Public License for more details.
14 
15    You should have received a copy of the GNU General Public License along
16    with Red Hat elfutils; if not, write to the Free Software Foundation,
17    Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA.
18 
19    In addition, as a special exception, Red Hat, Inc. gives You the
20    additional right to link the code of Red Hat elfutils with code licensed
21    under any Open Source Initiative certified open source license
22    (http://www.opensource.org/licenses/index.php) which requires the
23    distribution of source code with any binary distribution and to
24    distribute linked combinations of the two.  Non-GPL Code permitted under
25    this exception must only link to the code of Red Hat elfutils through
26    those well defined interfaces identified in the file named EXCEPTION
27    found in the source code files (the "Approved Interfaces").  The files
28    of Non-GPL Code may instantiate templates or use macros or inline
29    functions from the Approved Interfaces without causing the resulting
30    work to be covered by the GNU General Public License.  Only Red Hat,
31    Inc. may make changes or additions to the list of Approved Interfaces.
32    Red Hat's grant of this exception is conditioned upon your not adding
33    any new exceptions.  If you wish to add a new Approved Interface or
34    exception, please contact Red Hat.  You must obey the GNU General Public
35    License in all respects for all of the Red Hat elfutils code and other
36    code used in conjunction with Red Hat elfutils except the Non-GPL Code
37    covered by this exception.  If you modify this file, you may extend this
38    exception to your version of the file, but you are not obligated to do
39    so.  If you do not wish to provide this exception without modification,
40    you must delete this exception statement from your version and license
41    this file solely under the GPL without exception.
42 
43    Red Hat elfutils is an included package of the Open Invention Network.
44    An included package of the Open Invention Network is a package for which
45    Open Invention Network licensees cross-license their patents.  No patent
46    license is granted, either expressly or impliedly, by designation as an
47    included package.  Should you wish to participate in the Open Invention
48    Network licensing program, please visit www.openinventionnetwork.com
49    <http://www.openinventionnetwork.com>.  */
50 
51 #ifdef HAVE_CONFIG_H
52 # include <config.h>
53 #endif
54 
55 #include <byteswap.h>
56 #include <stdint.h>
57 #include <string.h>
58 #include <stdlib.h>
59 
60 #include "libelfP.h"
61 
62 #ifndef LIBELFBITS
63 # define LIBELFBITS	32
64 #endif
65 
66 
67 /* Well, what shall I say.  Nothing to do here.  */
68 #define elf_cvt_Byte(dest, src, n) \
69   (__builtin_constant_p (n) && (n) == 1					      \
70    ? (void) (*((char *) (dest)) = *((char *) (src)))			      \
71    : Elf32_cvt_Byte (dest, src, n))
72 static void
73 (elf_cvt_Byte) (void *dest, const void *src, size_t n,
74 		int encode __attribute__ ((unused)))
75 {
76   memmove (dest, src, n);
77 }
78 
79 
80 /* We'll optimize the definition of the conversion functions here a
81    bit.  We need only functions for 16, 32, and 64 bits.  The
82    functions referenced in the table will be aliases for one of these
83    functions.  Which one is decided by the ELFxx_FSZ_type.  */
84 
85 #if ALLOW_UNALIGNED
86 
87 #define FETCH(Bits, ptr)	(*(const uint##Bits##_t *) ptr)
88 #define STORE(Bits, ptr, val)	(*(uint##Bits##_t *) ptr = val)
89 
90 #else
91 
92 union unaligned
93   {
94     uint16_t u16;
95     uint32_t u32;
96     uint64_t u64;
97   } __attribute__ ((packed));
98 
99 #define FETCH(Bits, ptr)	(((const union unaligned *) ptr)->u##Bits)
100 #define STORE(Bits, ptr, val)	(((union unaligned *) ptr)->u##Bits = val)
101 
102 #endif
103 
104 /* Now define the conversion functions for the basic types.  We use here
105    the fact that file and memory types are the same and that we have the
106    ELFxx_FSZ_* macros.
107 
108    At the same time we define inline functions which we will use to
109    convert the complex types.  */
110 #define FUNDAMENTAL(NAME, Name, Bits) \
111   INLINE2 (ELFW2(Bits,FSZ_##NAME), ElfW2(Bits,cvt_##Name), ElfW2(Bits,Name))
112 #define INLINE2(Bytes, FName, TName) \
113   INLINE3 (Bytes, FName, TName)
114 #define INLINE3(Bytes, FName, TName)					      \
115   static inline void FName##1 (void *dest, const void *ptr)		      \
116   {									      \
117     switch (Bytes)							      \
118       {									      \
119       case 2: STORE (16, dest, bswap_16 (FETCH (16, ptr))); break;	      \
120       case 4: STORE (32, dest, bswap_32 (FETCH (32, ptr))); break;	      \
121       case 8: STORE (64, dest, bswap_64 (FETCH (64, ptr))); break;	      \
122       default:								      \
123 	abort ();							      \
124       }									      \
125   }									      \
126 									      \
127   static void FName (void *dest, const void *ptr, size_t len,		      \
128 		     int encode __attribute__ ((unused)))		      \
129   {									      \
130     size_t n = len / sizeof (TName);					      \
131     if (dest < ptr)							      \
132       while (n-- > 0)							      \
133 	{								      \
134 	  FName##1 (dest, ptr);						      \
135 	  dest += Bytes;						      \
136 	  ptr += Bytes;							      \
137 	}								      \
138     else								      \
139       {									      \
140 	dest += len;							      \
141 	ptr += len;							      \
142 	while (n-- > 0)							      \
143 	  {								      \
144 	    ptr -= Bytes;						      \
145 	    dest -= Bytes;						      \
146 	    FName##1 (dest, ptr);					      \
147 	  }								      \
148       }									      \
149   }
150 
151 
152 /* Now the tricky part: define the transformation functions for the
153    complex types.  We will use the definitions of the types in
154    abstract.h.  */
155 #define START(Bits, Name, EName) \
156   static void								      \
157   ElfW2 (Bits, cvt_##Name) (void *dest, const void *src, size_t len,	      \
158 			    int encode __attribute__ ((unused)))	      \
159   { ElfW2(Bits, Name) *tdest = (ElfW2(Bits, Name) *) dest;		      \
160     ElfW2(Bits, Name) *tsrc = (ElfW2(Bits, Name) *) src;		      \
161     size_t n;								      \
162     for (n = len / sizeof (ElfW2(Bits, Name)); n > 0; ++tdest, ++tsrc, --n) {
163 #define END(Bits, Name) } }
164 #define TYPE_EXTRA(Code)
165 #define TYPE_XLATE(Code) Code
166 #define TYPE_NAME(Type, Name) TYPE_NAME2 (Type, Name)
167 #define TYPE_NAME2(Type, Name) Type##1 (&tdest->Name, &tsrc->Name);
168 #define TYPE(Name, Bits) TYPE2 (Name, Bits)
169 #define TYPE2(Name, Bits) TYPE3 (Name##Bits)
170 #define TYPE3(Name) Name (cvt_)
171 
172 /* Signal that we are generating conversion functions.  */
173 #define GENERATE_CONVERSION
174 
175 /* First generate the 32-bit conversion functions.  */
176 #define LIBELFBITS 32
177 #include "gelf_xlate.h"
178 
179 /* Now generate the 64-bit conversion functions.  */
180 #define LIBELFBITS 64
181 #include "gelf_xlate.h"
182 
183 
184 /* We have a few functions which we must create by hand since the sections
185    do not contain records of only one type.  */
186 #include "version_xlate.h"
187 #include "gnuhash_xlate.h"
188 #include "note_xlate.h"
189 
190 
191 /* Now the externally visible table with the function pointers.  */
192 const xfct_t __elf_xfctstom[EV_NUM - 1][EV_NUM - 1][ELFCLASSNUM - 1][ELF_T_NUM] =
193 {
194   [EV_CURRENT - 1] = {
195     [EV_CURRENT - 1] = {
196       [ELFCLASS32 - 1] = {
197 #define define_xfcts(Bits) \
198 	[ELF_T_BYTE]	= elf_cvt_Byte,					      \
199 	[ELF_T_ADDR]	= ElfW2(Bits, cvt_Addr),			      \
200 	[ELF_T_DYN]	= ElfW2(Bits, cvt_Dyn),				      \
201 	[ELF_T_EHDR]	= ElfW2(Bits, cvt_Ehdr),			      \
202 	[ELF_T_HALF]	= ElfW2(Bits, cvt_Half),			      \
203 	[ELF_T_OFF]	= ElfW2(Bits, cvt_Off),				      \
204 	[ELF_T_PHDR]	= ElfW2(Bits, cvt_Phdr),			      \
205 	[ELF_T_RELA]	= ElfW2(Bits, cvt_Rela),			      \
206 	[ELF_T_REL]	= ElfW2(Bits, cvt_Rel),				      \
207 	[ELF_T_SHDR]	= ElfW2(Bits, cvt_Shdr),			      \
208 	[ELF_T_SWORD]	= ElfW2(Bits, cvt_Sword),			      \
209 	[ELF_T_SYM]	= ElfW2(Bits, cvt_Sym),				      \
210 	[ELF_T_WORD]	= ElfW2(Bits, cvt_Word),			      \
211 	[ELF_T_XWORD]	= ElfW2(Bits, cvt_Xword),			      \
212 	[ELF_T_SXWORD]	= ElfW2(Bits, cvt_Sxword),			      \
213 	[ELF_T_VDEF]	= elf_cvt_Verdef,				      \
214 	[ELF_T_VDAUX]	= elf_cvt_Verdef,				      \
215 	[ELF_T_VNEED]	= elf_cvt_Verneed,				      \
216 	[ELF_T_VNAUX]	= elf_cvt_Verneed,				      \
217 	[ELF_T_NHDR]	= elf_cvt_note,					      \
218 	[ELF_T_SYMINFO] = ElfW2(Bits, cvt_Syminfo),			      \
219 	[ELF_T_MOVE]	= ElfW2(Bits, cvt_Move),			      \
220 	[ELF_T_LIB]	= ElfW2(Bits, cvt_Lib),				      \
221 	[ELF_T_AUXV]	= ElfW2(Bits, cvt_auxv_t)
222         define_xfcts (32),
223 	[ELF_T_GNUHASH] = Elf32_cvt_Word
224       },
225       [ELFCLASS64 - 1] = {
226 	define_xfcts (64),
227 	[ELF_T_GNUHASH] = elf_cvt_gnuhash
228       }
229     }
230   }
231 };
232 /* For now we only handle the case where the memory representation is the
233    same as the file representation.  Should this change we have to define
234    separate functions.  For now reuse them.  */
235 #ifndef __APPLE__
236 strong_alias (__elf_xfctstom, __elf_xfctstof)
237 #endif
238