1 /* Unaligned memory access functionality. 2 Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005 Red Hat, Inc. 3 This file is part of Red Hat elfutils. 4 Written by Ulrich Drepper <drepper (at) redhat.com>, 2001. 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 #ifndef _MEMORY_ACCESS_H 52 #define _MEMORY_ACCESS_H 1 53 54 #include <byteswap.h> 55 #include <limits.h> 56 #include <stdint.h> 57 58 59 /* Number decoding macros. See 7.6 Variable Length Data. */ 60 61 #define get_uleb128_step(var, addr, nth, break) \ 62 __b = *(addr)++; \ 63 var |= (uintmax_t) (__b & 0x7f) << (nth * 7); \ 64 if (likely ((__b & 0x80) == 0)) \ 65 break 66 67 #define get_uleb128(var, addr) \ 68 do { \ 69 unsigned char __b; \ 70 var = 0; \ 71 get_uleb128_step (var, addr, 0, break); \ 72 var = __libdw_get_uleb128 (var, 1, &(addr)); \ 73 } while (0) 74 75 #define get_uleb128_rest_return(var, i, addrp) \ 76 do { \ 77 for (; i < 10; ++i) \ 78 { \ 79 get_uleb128_step (var, *addrp, i, return var); \ 80 } \ 81 /* Other implementations set VALUE to UINT_MAX in this \ 82 case. So we better do this as well. */ \ 83 return UINT64_MAX; \ 84 } while (0) 85 86 /* The signed case is similar, but we sign-extend the result. */ 87 88 #define get_sleb128_step(var, addr, nth, break) \ 89 __b = *(addr)++; \ 90 _v |= (uint64_t) (__b & 0x7f) << (nth * 7); \ 91 if (likely ((__b & 0x80) == 0)) \ 92 { \ 93 var = (_v << (64 - (nth * 7) - 7) >> (64 - (nth * 7) - 7)); \ 94 break; \ 95 } \ 96 else do {} while (0) 97 98 #define get_sleb128(var, addr) \ 99 do { \ 100 unsigned char __b; \ 101 int64_t _v = 0; \ 102 get_sleb128_step (var, addr, 0, break); \ 103 var = __libdw_get_sleb128 (_v, 1, &(addr)); \ 104 } while (0) 105 106 #define get_sleb128_rest_return(var, i, addrp) \ 107 do { \ 108 for (; i < 9; ++i) \ 109 { \ 110 get_sleb128_step (var, *addrp, i, return var); \ 111 } \ 112 /* Other implementations set VALUE to INT_MAX in this \ 113 case. So we better do this as well. */ \ 114 return INT64_MAX; \ 115 } while (0) 116 117 #ifdef IS_LIBDW 118 extern uint64_t __libdw_get_uleb128 (uint64_t acc, unsigned int i, 119 const unsigned char **addrp) 120 internal_function attribute_hidden; 121 extern int64_t __libdw_get_sleb128 (int64_t acc, unsigned int i, 122 const unsigned char **addrp) 123 internal_function attribute_hidden; 124 #else 125 static uint64_t 126 __attribute__ ((unused)) 127 __libdw_get_uleb128 (uint64_t acc, unsigned int i, const unsigned char **addrp) 128 { 129 unsigned char __b; 130 get_uleb128_rest_return (acc, i, addrp); 131 } 132 static int64_t 133 __attribute__ ((unused)) 134 __libdw_get_sleb128 (int64_t acc, unsigned int i, const unsigned char **addrp) 135 { 136 unsigned char __b; 137 int64_t _v = acc; 138 get_sleb128_rest_return (acc, i, addrp); 139 } 140 #endif 141 142 143 /* We use simple memory access functions in case the hardware allows it. 144 The caller has to make sure we don't have alias problems. */ 145 #if ALLOW_UNALIGNED 146 147 # define read_2ubyte_unaligned(Dbg, Addr) \ 148 (unlikely ((Dbg)->other_byte_order) \ 149 ? bswap_16 (*((const uint16_t *) (Addr))) \ 150 : *((const uint16_t *) (Addr))) 151 # define read_2sbyte_unaligned(Dbg, Addr) \ 152 (unlikely ((Dbg)->other_byte_order) \ 153 ? (int16_t) bswap_16 (*((const int16_t *) (Addr))) \ 154 : *((const int16_t *) (Addr))) 155 156 # define read_4ubyte_unaligned_noncvt(Addr) \ 157 *((const uint32_t *) (Addr)) 158 # define read_4ubyte_unaligned(Dbg, Addr) \ 159 (unlikely ((Dbg)->other_byte_order) \ 160 ? bswap_32 (*((const uint32_t *) (Addr))) \ 161 : *((const uint32_t *) (Addr))) 162 # define read_4sbyte_unaligned(Dbg, Addr) \ 163 (unlikely ((Dbg)->other_byte_order) \ 164 ? (int32_t) bswap_32 (*((const int32_t *) (Addr))) \ 165 : *((const int32_t *) (Addr))) 166 167 # define read_8ubyte_unaligned(Dbg, Addr) \ 168 (unlikely ((Dbg)->other_byte_order) \ 169 ? bswap_64 (*((const uint64_t *) (Addr))) \ 170 : *((const uint64_t *) (Addr))) 171 # define read_8sbyte_unaligned(Dbg, Addr) \ 172 (unlikely ((Dbg)->other_byte_order) \ 173 ? (int64_t) bswap_64 (*((const int64_t *) (Addr))) \ 174 : *((const int64_t *) (Addr))) 175 176 #else 177 178 union unaligned 179 { 180 void *p; 181 uint16_t u2; 182 uint32_t u4; 183 uint64_t u8; 184 int16_t s2; 185 int32_t s4; 186 int64_t s8; 187 } __attribute__ ((packed)); 188 189 static inline uint16_t 190 read_2ubyte_unaligned (Dwarf *dbg, const void *p) 191 { 192 const union unaligned *up = p; 193 if (dbg->other_byte_order) 194 return bswap_16 (up->u2); 195 return up->u2; 196 } 197 static inline int16_t 198 read_2sbyte_unaligned (Dwarf *dbg, const void *p) 199 { 200 const union unaligned *up = p; 201 if (dbg->other_byte_order) 202 return (int16_t) bswap_16 (up->u2); 203 return up->s2; 204 } 205 206 static inline uint32_t 207 read_4ubyte_unaligned_noncvt (const void *p) 208 { 209 const union unaligned *up = p; 210 return up->u4; 211 } 212 static inline uint32_t 213 read_4ubyte_unaligned (Dwarf *dbg, const void *p) 214 { 215 const union unaligned *up = p; 216 if (dbg->other_byte_order) 217 return bswap_32 (up->u4); 218 return up->u4; 219 } 220 static inline int32_t 221 read_4sbyte_unaligned (Dwarf *dbg, const void *p) 222 { 223 const union unaligned *up = p; 224 if (dbg->other_byte_order) 225 return (int32_t) bswap_32 (up->u4); 226 return up->s4; 227 } 228 229 static inline uint64_t 230 read_8ubyte_unaligned (Dwarf *dbg, const void *p) 231 { 232 const union unaligned *up = p; 233 if (dbg->other_byte_order) 234 return bswap_64 (up->u8); 235 return up->u8; 236 } 237 static inline int64_t 238 read_8sbyte_unaligned (Dwarf *dbg, const void *p) 239 { 240 const union unaligned *up = p; 241 if (dbg->other_byte_order) 242 return (int64_t) bswap_64 (up->u8); 243 return up->s8; 244 } 245 246 #endif /* allow unaligned */ 247 248 249 #define read_2ubyte_unaligned_inc(Dbg, Addr) \ 250 ({ uint16_t t_ = read_2ubyte_unaligned (Dbg, Addr); \ 251 Addr = (__typeof (Addr)) (((uintptr_t) (Addr)) + 2); \ 252 t_; }) 253 #define read_2sbyte_unaligned_inc(Dbg, Addr) \ 254 ({ int16_t t_ = read_2sbyte_unaligned (Dbg, Addr); \ 255 Addr = (__typeof (Addr)) (((uintptr_t) (Addr)) + 2); \ 256 t_; }) 257 258 #define read_4ubyte_unaligned_inc(Dbg, Addr) \ 259 ({ uint32_t t_ = read_4ubyte_unaligned (Dbg, Addr); \ 260 Addr = (__typeof (Addr)) (((uintptr_t) (Addr)) + 4); \ 261 t_; }) 262 #define read_4sbyte_unaligned_inc(Dbg, Addr) \ 263 ({ int32_t t_ = read_4sbyte_unaligned (Dbg, Addr); \ 264 Addr = (__typeof (Addr)) (((uintptr_t) (Addr)) + 4); \ 265 t_; }) 266 267 #define read_8ubyte_unaligned_inc(Dbg, Addr) \ 268 ({ uint64_t t_ = read_8ubyte_unaligned (Dbg, Addr); \ 269 Addr = (__typeof (Addr)) (((uintptr_t) (Addr)) + 8); \ 270 t_; }) 271 #define read_8sbyte_unaligned_inc(Dbg, Addr) \ 272 ({ int64_t t_ = read_8sbyte_unaligned (Dbg, Addr); \ 273 Addr = (__typeof (Addr)) (((uintptr_t) (Addr)) + 8); \ 274 t_; }) 275 276 #endif /* memory-access.h */ 277
