What to do with ELF '.group' sections
Posted: Sat Feb 19, 2011 12:25 pm
I'm working on my ELF linker to load relocatable ELF files for my modular kernel. I've implemented relocation and got it working. Then I added some code to work with a c++ class in my module and the linker blew up. I tried running readelf and there is about 150 '.group' sections now. Along with several sections that have a sh_addr of 0 (I link with a base address of 0) and a sh_size of not zero.
First, I just sequentially added 0-offset sections to the allocated virtual address and then relocate them (because the next section is a .rel section).
But that still doesn't work. I feel like I'm missing something with this whole ELF loader. Like I've done it wrong from the beginning. The '.group' sections have a type of 11 or DYNSYM. However there is no other DYNx sections in the file.
Anyway, any help on the right track would be much appreciated.
First, here is the readelf output of the module I'm trying to load:
And here is my code:
Thank you.
First, I just sequentially added 0-offset sections to the allocated virtual address and then relocate them (because the next section is a .rel section).
But that still doesn't work. I feel like I'm missing something with this whole ELF loader. Like I've done it wrong from the beginning. The '.group' sections have a type of 11 or DYNSYM. However there is no other DYNx sections in the file.
Anyway, any help on the right track would be much appreciated.
First, here is the readelf output of the module I'm trying to load:
Code: Select all
There are 393 section headers, starting at offset 0x1d10:
Section Headers:
[Nr] Name Type Addr Off Size ES Flg Lk Inf Al
[ 0] NULL 00000000 000000 000000 00 0 0 0
[ 1] .group GROUP 00000000 000034 000008 04 391 438 4
[ 2] .group GROUP 00000000 00003c 000008 04 391 393 4
[ 3] .group GROUP 00000000 000044 000008 04 391 548 4
[ 4] .group GROUP 00000000 00004c 00000c 04 391 326 4
[ 5] .group GROUP 00000000 000058 00000c 04 391 327 4
[ 6] .group GROUP 00000000 000064 00000c 04 391 328 4
[ 7] .group GROUP 00000000 000070 00000c 04 391 329 4
[ 8] .group GROUP 00000000 00007c 000008 04 391 397 4
[ 9] .group GROUP 00000000 000084 000008 04 391 366 4
[10] .group GROUP 00000000 00008c 000008 04 391 500 4
[11] .group GROUP 00000000 000094 000008 04 391 418 4
[12] .group GROUP 00000000 00009c 000008 04 391 543 4
[13] .group GROUP 00000000 0000a4 000008 04 391 549 4
[14] .group GROUP 00000000 0000ac 000008 04 391 557 4
[15] .group GROUP 00000000 0000b4 000008 04 391 411 4
[16] .group GROUP 00000000 0000bc 000008 04 391 402 4
[17] .group GROUP 00000000 0000c4 000008 04 391 508 4
[18] .group GROUP 00000000 0000cc 000008 04 391 477 4
[19] .group GROUP 00000000 0000d4 000008 04 391 503 4
[20] .group GROUP 00000000 0000dc 000008 04 391 494 4
[21] .group GROUP 00000000 0000e4 000008 04 391 547 4
[22] .group GROUP 00000000 0000ec 000008 04 391 485 4
[23] .group GROUP 00000000 0000f4 000008 04 391 528 4
[24] .group GROUP 00000000 0000fc 000008 04 391 420 4
[25] .group GROUP 00000000 000104 000008 04 391 465 4
[26] .group GROUP 00000000 00010c 000008 04 391 419 4
[27] .group GROUP 00000000 000114 000008 04 391 409 4
[28] .group GROUP 00000000 00011c 000008 04 391 441 4
[29] .group GROUP 00000000 000124 000008 04 391 480 4
[30] .group GROUP 00000000 00012c 000008 04 391 353 4
[31] .group GROUP 00000000 000134 000008 04 391 417 4
[32] .group GROUP 00000000 00013c 000008 04 391 463 4
[33] .group GROUP 00000000 000144 000008 04 391 545 4
[34] .group GROUP 00000000 00014c 000008 04 391 429 4
[35] .group GROUP 00000000 000154 000008 04 391 491 4
[36] .group GROUP 00000000 00015c 000008 04 391 454 4
[37] .group GROUP 00000000 000164 000008 04 391 512 4
[38] .group GROUP 00000000 00016c 000008 04 391 392 4
[39] .group GROUP 00000000 000174 000008 04 391 385 4
[40] .group GROUP 00000000 00017c 000008 04 391 540 4
[41] .group GROUP 00000000 000184 000008 04 391 468 4
[42] .group GROUP 00000000 00018c 000008 04 391 518 4
[43] .group GROUP 00000000 000194 000008 04 391 464 4
[44] .group GROUP 00000000 00019c 000008 04 391 355 4
[45] .group GROUP 00000000 0001a4 000008 04 391 435 4
[46] .group GROUP 00000000 0001ac 000008 04 391 479 4
[47] .group GROUP 00000000 0001b4 000008 04 391 376 4
[48] .group GROUP 00000000 0001bc 000008 04 391 527 4
[49] .group GROUP 00000000 0001c4 000008 04 391 386 4
[50] .group GROUP 00000000 0001cc 000008 04 391 498 4
[51] .group GROUP 00000000 0001d4 000008 04 391 444 4
[52] .group GROUP 00000000 0001dc 000008 04 391 551 4
[53] .group GROUP 00000000 0001e4 000008 04 391 529 4
[54] .group GROUP 00000000 0001ec 000008 04 391 460 4
[55] .group GROUP 00000000 0001f4 000008 04 391 462 4
[56] .group GROUP 00000000 0001fc 000008 04 391 516 4
[57] .group GROUP 00000000 000204 000008 04 391 552 4
[58] .group GROUP 00000000 00020c 000008 04 391 352 4
[59] .group GROUP 00000000 000214 000008 04 391 489 4
[60] .group GROUP 00000000 00021c 000008 04 391 499 4
[61] .group GROUP 00000000 000224 000008 04 391 351 4
[62] .group GROUP 00000000 00022c 000008 04 391 492 4
[63] .group GROUP 00000000 000234 000008 04 391 408 4
[64] .group GROUP 00000000 00023c 000008 04 391 360 4
[65] .group GROUP 00000000 000244 000008 04 391 348 4
[66] .group GROUP 00000000 00024c 000008 04 391 554 4
[67] .group GROUP 00000000 000254 000008 04 391 459 4
[68] .group GROUP 00000000 00025c 000008 04 391 426 4
[69] .group GROUP 00000000 000264 000008 04 391 461 4
[70] .group GROUP 00000000 00026c 000008 04 391 350 4
[71] .group GROUP 00000000 000274 000008 04 391 381 4
[72] .group GROUP 00000000 00027c 000008 04 391 415 4
[73] .group GROUP 00000000 000284 000008 04 391 389 4
[74] .group GROUP 00000000 00028c 000008 04 391 522 4
[75] .group GROUP 00000000 000294 000008 04 391 388 4
[76] .group GROUP 00000000 00029c 000008 04 391 534 4
[77] .group GROUP 00000000 0002a4 000008 04 391 513 4
[78] .group GROUP 00000000 0002ac 000008 04 391 405 4
[79] .group GROUP 00000000 0002b4 000008 04 391 410 4
[80] .group GROUP 00000000 0002bc 000008 04 391 423 4
[81] .group GROUP 00000000 0002c4 000008 04 391 470 4
[82] .group GROUP 00000000 0002cc 000008 04 391 422 4
[83] .group GROUP 00000000 0002d4 000008 04 391 467 4
[84] .group GROUP 00000000 0002dc 000008 04 391 510 4
[85] .group GROUP 00000000 0002e4 000008 04 391 519 4
[86] .group GROUP 00000000 0002ec 000008 04 391 514 4
[87] .group GROUP 00000000 0002f4 000008 04 391 361 4
[88] .group GROUP 00000000 0002fc 000008 04 391 541 4
[89] .group GROUP 00000000 000304 000008 04 391 431 4
[90] .group GROUP 00000000 00030c 000008 04 391 432 4
[91] .group GROUP 00000000 000314 000008 04 391 428 4
[92] .group GROUP 00000000 00031c 000008 04 391 450 4
[93] .group GROUP 00000000 000324 000008 04 391 523 4
[94] .group GROUP 00000000 00032c 000008 04 391 505 4
[95] .group GROUP 00000000 000334 000008 04 391 483 4
[96] .group GROUP 00000000 00033c 000008 04 391 403 4
[97] .group GROUP 00000000 000344 000008 04 391 427 4
[98] .group GROUP 00000000 00034c 000008 04 391 539 4
[99] .group GROUP 00000000 000354 000008 04 391 471 4
[100] .group GROUP 00000000 00035c 000008 04 391 425 4
[101] .group GROUP 00000000 000364 000008 04 391 488 4
[102] .group GROUP 00000000 00036c 000008 04 391 375 4
[103] .group GROUP 00000000 000374 000008 04 391 413 4
[104] .group GROUP 00000000 00037c 000008 04 391 532 4
[105] .group GROUP 00000000 000384 000008 04 391 448 4
[106] .group GROUP 00000000 00038c 000008 04 391 359 4
[107] .group GROUP 00000000 000394 000008 04 391 550 4
[108] .group GROUP 00000000 00039c 000008 04 391 407 4
[109] .group GROUP 00000000 0003a4 000008 04 391 362 4
[110] .group GROUP 00000000 0003ac 000008 04 391 434 4
[111] .group GROUP 00000000 0003b4 000008 04 391 383 4
[112] .group GROUP 00000000 0003bc 000008 04 391 442 4
[113] .group GROUP 00000000 0003c4 000008 04 391 533 4
[114] .group GROUP 00000000 0003cc 000008 04 391 452 4
[115] .group GROUP 00000000 0003d4 000008 04 391 357 4
[116] .group GROUP 00000000 0003dc 000008 04 391 367 4
[117] .group GROUP 00000000 0003e4 000008 04 391 414 4
[118] .group GROUP 00000000 0003ec 000008 04 391 424 4
[119] .group GROUP 00000000 0003f4 000008 04 391 531 4
[120] .group GROUP 00000000 0003fc 000008 04 391 563 4
[121] .group GROUP 00000000 000404 000008 04 391 398 4
[122] .group GROUP 00000000 00040c 000008 04 391 526 4
[123] .group GROUP 00000000 000414 000008 04 391 562 4
[124] .group GROUP 00000000 00041c 000008 04 391 535 4
[125] .group GROUP 00000000 000424 000008 04 391 421 4
[126] .group GROUP 00000000 00042c 000008 04 391 521 4
[127] .group GROUP 00000000 000434 000008 04 391 561 4
[128] .group GROUP 00000000 00043c 000008 04 391 455 4
[129] .group GROUP 00000000 000444 000008 04 391 473 4
[130] .group GROUP 00000000 00044c 000008 04 391 377 4
[131] .group GROUP 00000000 000454 000008 04 391 354 4
[132] .group GROUP 00000000 00045c 000008 04 391 373 4
[133] .group GROUP 00000000 000464 000008 04 391 506 4
[134] .group GROUP 00000000 00046c 000008 04 391 451 4
[135] .group GROUP 00000000 000474 000008 04 391 390 4
[136] .group GROUP 00000000 00047c 000008 04 391 371 4
[137] .group GROUP 00000000 000484 000008 04 391 497 4
[138] .group GROUP 00000000 00048c 000008 04 391 443 4
[139] .group GROUP 00000000 000494 000008 04 391 437 4
[140] .group GROUP 00000000 00049c 000008 04 391 447 4
[141] .group GROUP 00000000 0004a4 000008 04 391 553 4
[142] .group GROUP 00000000 0004ac 000008 04 391 430 4
[143] .group GROUP 00000000 0004b4 000008 04 391 504 4
[144] .group GROUP 00000000 0004bc 000008 04 391 374 4
[145] .group GROUP 00000000 0004c4 000008 04 391 458 4
[146] .group GROUP 00000000 0004cc 000008 04 391 372 4
[147] .group GROUP 00000000 0004d4 000008 04 391 380 4
[148] .group GROUP 00000000 0004dc 000008 04 391 387 4
[149] .group GROUP 00000000 0004e4 000008 04 391 524 4
[150] .text PROGBITS 00000000 0004f0 000627 00 AX 0 0 16
[151] .rel.text REL 00000000 005a78 000150 08 391 150 4
[152] .text._ZNSt9type_ PROGBITS 00000000 000b18 00000e 00 AXG 0 0 2
[153] .rel.text._ZNSt9t REL 00000000 005bc8 000008 08 391 152 4
[154] .text._ZN10__cxxa PROGBITS 00000000 000b26 00000e 00 AXG 0 0 2
[155] .rel.text._ZN10__ REL 00000000 005bd0 000008 08 391 154 4
[156] .text._ZN10__cxxa PROGBITS 00000000 000b34 00000e 00 AXG 0 0 2
[157] .rel.text._ZN10__ REL 00000000 005bd8 000008 08 391 156 4
[158] .text._ZN10__cxxa PROGBITS 00000000 000b42 00000e 00 AXG 0 0 2
[159] .rel.text._ZN10__ REL 00000000 005be0 000008 08 391 158 4
[160] .text._ZN10__cxxa PROGBITS 00000000 000b50 000015 00 AXG 0 0 2
[161] .rel.text._ZN10__ REL 00000000 005be8 000010 08 391 160 4
[162] .text._ZN10__cxxa PROGBITS 00000000 000b66 000015 00 AXG 0 0 2
[163] .rel.text._ZN10__ REL 00000000 005bf8 000010 08 391 162 4
[164] .text._ZN10__cxxa PROGBITS 00000000 000b7c 000015 00 AXG 0 0 2
[165] .rel.text._ZN10__ REL 00000000 005c08 000010 08 391 164 4
[166] .text._ZNSt9type_ PROGBITS 00000000 000b92 000015 00 AXG 0 0 2
[167] .rel.text._ZNSt9t REL 00000000 005c18 000010 08 391 166 4
[168] .rodata PROGBITS 00001000 000ba7 000000 00 WA 0 0 1
[169] .rodata._ZTVN6sys PROGBITS 00000000 000ba8 000018 00 AG 0 0 8
[170] .rel.rodata._ZTVN REL 00000000 005c28 000020 08 391 169 4
[171] .rodata._ZTIPKDn PROGBITS 00000000 000bc0 000010 00 AG 0 0 4
[172] .rel.rodata._ZTIP REL 00000000 005c48 000018 08 391 171 4
[173] .rodata._ZTIPDn PROGBITS 00000000 000bd0 000010 00 AG 0 0 4
[174] .rel.rodata._ZTIP REL 00000000 005c60 000018 08 391 173 4
[175] .rodata._ZTIDn PROGBITS 00000000 000be0 000008 00 AG 0 0 4
[176] .rel.rodata._ZTID REL 00000000 005c78 000010 08 391 175 4
[177] .rodata._ZTIPKDe PROGBITS 00000000 000be8 000010 00 AG 0 0 4
[178] .rel.rodata._ZTIP REL 00000000 005c88 000018 08 391 177 4
[179] .rodata._ZTIPDe PROGBITS 00000000 000bf8 000010 00 AG 0 0 4
[180] .rel.rodata._ZTIP REL 00000000 005ca0 000018 08 391 179 4
[181] .rodata._ZTIDe PROGBITS 00000000 000c08 000008 00 AG 0 0 4
[182] .rel.rodata._ZTID REL 00000000 005cb8 000010 08 391 181 4
[183] .rodata._ZTIPKDd PROGBITS 00000000 000c10 000010 00 AG 0 0 4
[184] .rel.rodata._ZTIP REL 00000000 005cc8 000018 08 391 183 4
[185] .rodata._ZTIPDd PROGBITS 00000000 000c20 000010 00 AG 0 0 4
[186] .rel.rodata._ZTIP REL 00000000 005ce0 000018 08 391 185 4
[187] .rodata._ZTIDd PROGBITS 00000000 000c30 000008 00 AG 0 0 4
[188] .rel.rodata._ZTID REL 00000000 005cf8 000010 08 391 187 4
[189] .rodata._ZTIPKDf PROGBITS 00000000 000c38 000010 00 AG 0 0 4
[190] .rel.rodata._ZTIP REL 00000000 005d08 000018 08 391 189 4
[191] .rodata._ZTIPDf PROGBITS 00000000 000c48 000010 00 AG 0 0 4
[192] .rel.rodata._ZTIP REL 00000000 005d20 000018 08 391 191 4
[193] .rodata._ZTIDf PROGBITS 00000000 000c58 000008 00 AG 0 0 4
[194] .rel.rodata._ZTID REL 00000000 005d38 000010 08 391 193 4
[195] .rodata._ZTIPKe PROGBITS 00000000 000c60 000010 00 AG 0 0 4
[196] .rel.rodata._ZTIP REL 00000000 005d48 000018 08 391 195 4
[197] .rodata._ZTIPe PROGBITS 00000000 000c70 000010 00 AG 0 0 4
[198] .rel.rodata._ZTIP REL 00000000 005d60 000018 08 391 197 4
[199] .rodata._ZTIe PROGBITS 00000000 000c80 000008 00 AG 0 0 4
[200] .rel.rodata._ZTIe REL 00000000 005d78 000010 08 391 199 4
[201] .rodata._ZTIPKd PROGBITS 00000000 000c88 000010 00 AG 0 0 4
[202] .rel.rodata._ZTIP REL 00000000 005d88 000018 08 391 201 4
[203] .rodata._ZTIPd PROGBITS 00000000 000c98 000010 00 AG 0 0 4
[204] .rel.rodata._ZTIP REL 00000000 005da0 000018 08 391 203 4
[205] .rodata._ZTId PROGBITS 00000000 000ca8 000008 00 AG 0 0 4
[206] .rel.rodata._ZTId REL 00000000 005db8 000010 08 391 205 4
[207] .rodata._ZTIPKf PROGBITS 00000000 000cb0 000010 00 AG 0 0 4
[208] .rel.rodata._ZTIP REL 00000000 005dc8 000018 08 391 207 4
[209] .rodata._ZTIPf PROGBITS 00000000 000cc0 000010 00 AG 0 0 4
[210] .rel.rodata._ZTIP REL 00000000 005de0 000018 08 391 209 4
[211] .rodata._ZTIf PROGBITS 00000000 000cd0 000008 00 AG 0 0 4
[212] .rel.rodata._ZTIf REL 00000000 005df8 000010 08 391 211 4
[213] .rodata._ZTIPKy PROGBITS 00000000 000cd8 000010 00 AG 0 0 4
[214] .rel.rodata._ZTIP REL 00000000 005e08 000018 08 391 213 4
[215] .rodata._ZTIPy PROGBITS 00000000 000ce8 000010 00 AG 0 0 4
[216] .rel.rodata._ZTIP REL 00000000 005e20 000018 08 391 215 4
[217] .rodata._ZTIy PROGBITS 00000000 000cf8 000008 00 AG 0 0 4
[218] .rel.rodata._ZTIy REL 00000000 005e38 000010 08 391 217 4
[219] .rodata._ZTIPKx PROGBITS 00000000 000d00 000010 00 AG 0 0 4
[220] .rel.rodata._ZTIP REL 00000000 005e48 000018 08 391 219 4
[221] .rodata._ZTIPx PROGBITS 00000000 000d10 000010 00 AG 0 0 4
[222] .rel.rodata._ZTIP REL 00000000 005e60 000018 08 391 221 4
[223] .rodata._ZTIx PROGBITS 00000000 000d20 000008 00 AG 0 0 4
[224] .rel.rodata._ZTIx REL 00000000 005e78 000010 08 391 223 4
[225] .rodata._ZTIPKm PROGBITS 00000000 000d28 000010 00 AG 0 0 4
[226] .rel.rodata._ZTIP REL 00000000 005e88 000018 08 391 225 4
[227] .rodata._ZTIPm PROGBITS 00000000 000d38 000010 00 AG 0 0 4
[228] .rel.rodata._ZTIP REL 00000000 005ea0 000018 08 391 227 4
[229] .rodata._ZTIm PROGBITS 00000000 000d48 000008 00 AG 0 0 4
[230] .rel.rodata._ZTIm REL 00000000 005eb8 000010 08 391 229 4
[231] .rodata._ZTIPKl PROGBITS 00000000 000d50 000010 00 AG 0 0 4
[232] .rel.rodata._ZTIP REL 00000000 005ec8 000018 08 391 231 4
[233] .rodata._ZTIPl PROGBITS 00000000 000d60 000010 00 AG 0 0 4
[234] .rel.rodata._ZTIP REL 00000000 005ee0 000018 08 391 233 4
[235] .rodata._ZTIl PROGBITS 00000000 000d70 000008 00 AG 0 0 4
[236] .rel.rodata._ZTIl REL 00000000 005ef8 000010 08 391 235 4
[237] .rodata._ZTIPKj PROGBITS 00000000 000d78 000010 00 AG 0 0 4
[238] .rel.rodata._ZTIP REL 00000000 005f08 000018 08 391 237 4
[239] .rodata._ZTIPj PROGBITS 00000000 000d88 000010 00 AG 0 0 4
[240] .rel.rodata._ZTIP REL 00000000 005f20 000018 08 391 239 4
[241] .rodata._ZTIj PROGBITS 00000000 000d98 000008 00 AG 0 0 4
[242] .rel.rodata._ZTIj REL 00000000 005f38 000010 08 391 241 4
[243] .rodata._ZTIPKi PROGBITS 00000000 000da0 000010 00 AG 0 0 4
[244] .rel.rodata._ZTIP REL 00000000 005f48 000018 08 391 243 4
[245] .rodata._ZTIPi PROGBITS 00000000 000db0 000010 00 AG 0 0 4
[246] .rel.rodata._ZTIP REL 00000000 005f60 000018 08 391 245 4
[247] .rodata._ZTIi PROGBITS 00000000 000dc0 000008 00 AG 0 0 4
[248] .rel.rodata._ZTIi REL 00000000 005f78 000010 08 391 247 4
[249] .rodata._ZTIPKt PROGBITS 00000000 000dc8 000010 00 AG 0 0 4
[250] .rel.rodata._ZTIP REL 00000000 005f88 000018 08 391 249 4
[251] .rodata._ZTIPt PROGBITS 00000000 000dd8 000010 00 AG 0 0 4
[252] .rel.rodata._ZTIP REL 00000000 005fa0 000018 08 391 251 4
[253] .rodata._ZTIt PROGBITS 00000000 000de8 000008 00 AG 0 0 4
[254] .rel.rodata._ZTIt REL 00000000 005fb8 000010 08 391 253 4
[255] .rodata._ZTIPKs PROGBITS 00000000 000df0 000010 00 AG 0 0 4
[256] .rel.rodata._ZTIP REL 00000000 005fc8 000018 08 391 255 4
[257] .rodata._ZTIPs PROGBITS 00000000 000e00 000010 00 AG 0 0 4
[258] .rel.rodata._ZTIP REL 00000000 005fe0 000018 08 391 257 4
[259] .rodata._ZTIs PROGBITS 00000000 000e10 000008 00 AG 0 0 4
[260] .rel.rodata._ZTIs REL 00000000 005ff8 000010 08 391 259 4
[261] .rodata._ZTIPKh PROGBITS 00000000 000e18 000010 00 AG 0 0 4
[262] .rel.rodata._ZTIP REL 00000000 006008 000018 08 391 261 4
[263] .rodata._ZTIPh PROGBITS 00000000 000e28 000010 00 AG 0 0 4
[264] .rel.rodata._ZTIP REL 00000000 006020 000018 08 391 263 4
[265] .rodata._ZTIh PROGBITS 00000000 000e38 000008 00 AG 0 0 4
[266] .rel.rodata._ZTIh REL 00000000 006038 000010 08 391 265 4
[267] .rodata._ZTIPKa PROGBITS 00000000 000e40 000010 00 AG 0 0 4
[268] .rel.rodata._ZTIP REL 00000000 006048 000018 08 391 267 4
[269] .rodata._ZTIPa PROGBITS 00000000 000e50 000010 00 AG 0 0 4
[270] .rel.rodata._ZTIP REL 00000000 006060 000018 08 391 269 4
[271] .rodata._ZTIa PROGBITS 00000000 000e60 000008 00 AG 0 0 4
[272] .rel.rodata._ZTIa REL 00000000 006078 000010 08 391 271 4
[273] .rodata._ZTIPKc PROGBITS 00000000 000e68 000010 00 AG 0 0 4
[274] .rel.rodata._ZTIP REL 00000000 006088 000018 08 391 273 4
[275] .rodata._ZTIPc PROGBITS 00000000 000e78 000010 00 AG 0 0 4
[276] .rel.rodata._ZTIP REL 00000000 0060a0 000018 08 391 275 4
[277] .rodata._ZTIc PROGBITS 00000000 000e88 000008 00 AG 0 0 4
[278] .rel.rodata._ZTIc REL 00000000 0060b8 000010 08 391 277 4
[279] .rodata._ZTIPKDi PROGBITS 00000000 000e90 000010 00 AG 0 0 4
[280] .rel.rodata._ZTIP REL 00000000 0060c8 000018 08 391 279 4
[281] .rodata._ZTIPDi PROGBITS 00000000 000ea0 000010 00 AG 0 0 4
[282] .rel.rodata._ZTIP REL 00000000 0060e0 000018 08 391 281 4
[283] .rodata._ZTIDi PROGBITS 00000000 000eb0 000008 00 AG 0 0 4
[284] .rel.rodata._ZTID REL 00000000 0060f8 000010 08 391 283 4
[285] .rodata._ZTIPKDs PROGBITS 00000000 000eb8 000010 00 AG 0 0 4
[286] .rel.rodata._ZTIP REL 00000000 006108 000018 08 391 285 4
[287] .rodata._ZTIPDs PROGBITS 00000000 000ec8 000010 00 AG 0 0 4
[288] .rel.rodata._ZTIP REL 00000000 006120 000018 08 391 287 4
[289] .rodata._ZTIDs PROGBITS 00000000 000ed8 000008 00 AG 0 0 4
[290] .rel.rodata._ZTID REL 00000000 006138 000010 08 391 289 4
[291] .rodata._ZTIPKw PROGBITS 00000000 000ee0 000010 00 AG 0 0 4
[292] .rel.rodata._ZTIP REL 00000000 006148 000018 08 391 291 4
[293] .rodata._ZTIPw PROGBITS 00000000 000ef0 000010 00 AG 0 0 4
[294] .rel.rodata._ZTIP REL 00000000 006160 000018 08 391 293 4
[295] .rodata._ZTIw PROGBITS 00000000 000f00 000008 00 AG 0 0 4
[296] .rel.rodata._ZTIw REL 00000000 006178 000010 08 391 295 4
[297] .rodata._ZTIPKb PROGBITS 00000000 000f08 000010 00 AG 0 0 4
[298] .rel.rodata._ZTIP REL 00000000 006188 000018 08 391 297 4
[299] .rodata._ZTIPb PROGBITS 00000000 000f18 000010 00 AG 0 0 4
[300] .rel.rodata._ZTIP REL 00000000 0061a0 000018 08 391 299 4
[301] .rodata._ZTIb PROGBITS 00000000 000f28 000008 00 AG 0 0 4
[302] .rel.rodata._ZTIb REL 00000000 0061b8 000010 08 391 301 4
[303] .rodata._ZTIPKv PROGBITS 00000000 000f30 000010 00 AG 0 0 4
[304] .rel.rodata._ZTIP REL 00000000 0061c8 000018 08 391 303 4
[305] .rodata._ZTIPv PROGBITS 00000000 000f40 000010 00 AG 0 0 4
[306] .rel.rodata._ZTIP REL 00000000 0061e0 000018 08 391 305 4
[307] .rodata._ZTIv PROGBITS 00000000 000f50 000008 00 AG 0 0 4
[308] .rel.rodata._ZTIv REL 00000000 0061f8 000010 08 391 307 4
[309] .rodata._ZTVN10__ PROGBITS 00000000 000f58 000010 00 AG 0 0 8
[310] .rel.rodata._ZTVN REL 00000000 006208 000010 08 391 309 4
[311] .rodata._ZTVSt9ty PROGBITS 00000000 000f68 000010 00 AG 0 0 8
[312] .rel.rodata._ZTVS REL 00000000 006218 000010 08 391 311 4
[313] .rodata._ZTVN10__ PROGBITS 00000000 000f78 000010 00 AG 0 0 8
[314] .rel.rodata._ZTVN REL 00000000 006228 000010 08 391 313 4
[315] .rodata._ZTVN10__ PROGBITS 00000000 000f88 000010 00 AG 0 0 8
[316] .rel.rodata._ZTVN REL 00000000 006238 000010 08 391 315 4
[317] .rodata._ZTSPKDn PROGBITS 00000000 000f98 000005 00 AG 0 0 4
[318] .rodata._ZTSPDn PROGBITS 00000000 000fa0 000004 00 AG 0 0 4
[319] .rodata._ZTSDn PROGBITS 00000000 000fa4 000003 00 AG 0 0 1
[320] .rodata._ZTSPKDe PROGBITS 00000000 000fa8 000005 00 AG 0 0 4
[321] .rodata._ZTSPDe PROGBITS 00000000 000fb0 000004 00 AG 0 0 4
[322] .rodata._ZTSDe PROGBITS 00000000 000fb4 000003 00 AG 0 0 1
[323] .rodata._ZTSPKDd PROGBITS 00000000 000fb8 000005 00 AG 0 0 4
[324] .rodata._ZTSPDd PROGBITS 00000000 000fc0 000004 00 AG 0 0 4
[325] .rodata._ZTSDd PROGBITS 00000000 000fc4 000003 00 AG 0 0 1
[326] .rodata._ZTSPKDf PROGBITS 00000000 000fc8 000005 00 AG 0 0 4
[327] .rodata._ZTSPDf PROGBITS 00000000 000fd0 000004 00 AG 0 0 4
[328] .rodata._ZTSDf PROGBITS 00000000 000fd4 000003 00 AG 0 0 1
[329] .rodata._ZTSPKe PROGBITS 00000000 000fd8 000004 00 AG 0 0 4
[330] .rodata._ZTSPe PROGBITS 00000000 000fdc 000003 00 AG 0 0 1
[331] .rodata._ZTSe PROGBITS 00000000 000fdf 000002 00 AG 0 0 1
[332] .rodata._ZTSPKd PROGBITS 00000000 000fe4 000004 00 AG 0 0 4
[333] .rodata._ZTSPd PROGBITS 00000000 000fe8 000003 00 AG 0 0 1
[334] .rodata._ZTSd PROGBITS 00000000 000feb 000002 00 AG 0 0 1
[335] .rodata._ZTSPKf PROGBITS 00000000 000ff0 000004 00 AG 0 0 4
[336] .rodata._ZTSPf PROGBITS 00000000 000ff4 000003 00 AG 0 0 1
[337] .rodata._ZTSf PROGBITS 00000000 000ff7 000002 00 AG 0 0 1
[338] .rodata._ZTSPKy PROGBITS 00000000 000ffc 000004 00 AG 0 0 4
[339] .rodata._ZTSPy PROGBITS 00000000 001000 000003 00 AG 0 0 1
[340] .rodata._ZTSy PROGBITS 00000000 001003 000002 00 AG 0 0 1
[341] .rodata._ZTSPKx PROGBITS 00000000 001008 000004 00 AG 0 0 4
[342] .rodata._ZTSPx PROGBITS 00000000 00100c 000003 00 AG 0 0 1
[343] .rodata._ZTSx PROGBITS 00000000 00100f 000002 00 AG 0 0 1
[344] .rodata._ZTSPKm PROGBITS 00000000 001014 000004 00 AG 0 0 4
[345] .rodata._ZTSPm PROGBITS 00000000 001018 000003 00 AG 0 0 1
[346] .rodata._ZTSm PROGBITS 00000000 00101b 000002 00 AG 0 0 1
[347] .rodata._ZTSPKl PROGBITS 00000000 001020 000004 00 AG 0 0 4
[348] .rodata._ZTSPl PROGBITS 00000000 001024 000003 00 AG 0 0 1
[349] .rodata._ZTSl PROGBITS 00000000 001027 000002 00 AG 0 0 1
[350] .rodata._ZTSPKj PROGBITS 00000000 00102c 000004 00 AG 0 0 4
[351] .rodata._ZTSPj PROGBITS 00000000 001030 000003 00 AG 0 0 1
[352] .rodata._ZTSj PROGBITS 00000000 001033 000002 00 AG 0 0 1
[353] .rodata._ZTSPKi PROGBITS 00000000 001038 000004 00 AG 0 0 4
[354] .rodata._ZTSPi PROGBITS 00000000 00103c 000003 00 AG 0 0 1
[355] .rodata._ZTSi PROGBITS 00000000 00103f 000002 00 AG 0 0 1
[356] .rodata._ZTSPKt PROGBITS 00000000 001044 000004 00 AG 0 0 4
[357] .rodata._ZTSPt PROGBITS 00000000 001048 000003 00 AG 0 0 1
[358] .rodata._ZTSt PROGBITS 00000000 00104b 000002 00 AG 0 0 1
[359] .rodata._ZTSPKs PROGBITS 00000000 001050 000004 00 AG 0 0 4
[360] .rodata._ZTSPs PROGBITS 00000000 001054 000003 00 AG 0 0 1
[361] .rodata._ZTSs PROGBITS 00000000 001057 000002 00 AG 0 0 1
[362] .rodata._ZTSPKh PROGBITS 00000000 00105c 000004 00 AG 0 0 4
[363] .rodata._ZTSPh PROGBITS 00000000 001060 000003 00 AG 0 0 1
[364] .rodata._ZTSh PROGBITS 00000000 001063 000002 00 AG 0 0 1
[365] .rodata._ZTSPKa PROGBITS 00000000 001068 000004 00 AG 0 0 4
[366] .rodata._ZTSPa PROGBITS 00000000 00106c 000003 00 AG 0 0 1
[367] .rodata._ZTSa PROGBITS 00000000 00106f 000002 00 AG 0 0 1
[368] .rodata._ZTSPKc PROGBITS 00000000 001074 000004 00 AG 0 0 4
[369] .rodata._ZTSPc PROGBITS 00000000 001078 000003 00 AG 0 0 1
[370] .rodata._ZTSc PROGBITS 00000000 00107b 000002 00 AG 0 0 1
[371] .rodata._ZTSPKDi PROGBITS 00000000 001080 000005 00 AG 0 0 4
[372] .rodata._ZTSPDi PROGBITS 00000000 001088 000004 00 AG 0 0 4
[373] .rodata._ZTSDi PROGBITS 00000000 00108c 000003 00 AG 0 0 1
[374] .rodata._ZTSPKDs PROGBITS 00000000 001090 000005 00 AG 0 0 4
[375] .rodata._ZTSPDs PROGBITS 00000000 001098 000004 00 AG 0 0 4
[376] .rodata._ZTSDs PROGBITS 00000000 00109c 000003 00 AG 0 0 1
[377] .rodata._ZTSPKw PROGBITS 00000000 0010a0 000004 00 AG 0 0 4
[378] .rodata._ZTSPw PROGBITS 00000000 0010a4 000003 00 AG 0 0 1
[379] .rodata._ZTSw PROGBITS 00000000 0010a7 000002 00 AG 0 0 1
[380] .rodata._ZTSPKb PROGBITS 00000000 0010ac 000004 00 AG 0 0 4
[381] .rodata._ZTSPb PROGBITS 00000000 0010b0 000003 00 AG 0 0 1
[382] .rodata._ZTSb PROGBITS 00000000 0010b3 000002 00 AG 0 0 1
[383] .rodata._ZTSPKv PROGBITS 00000000 0010b8 000004 00 AG 0 0 4
[384] .rodata._ZTSPv PROGBITS 00000000 0010bc 000003 00 AG 0 0 1
[385] .rodata._ZTSv PROGBITS 00000000 0010bf 000002 00 AG 0 0 1
[386] .data PROGBITS 00001000 0010c4 000000 00 WA 0 0 4
[387] .bss NOBITS 00001000 0010c4 004500 00 WA 0 0 4
[388] .bss._ZGVZN6syste NOBITS 00000000 0010c8 000008 00 WAG 0 0 8
[389] .bss._ZZN6system7 NOBITS 00000000 0010c8 000008 00 WAG 0 0 4
[390] .shstrtab STRTAB 00000000 0010c8 000c48 00 0 0 1
[391] .symtab SYMTAB 00000000 006248 002350 10 392 348 4
[392] .strtab STRTAB 00000000 008598 000f97 00 0 0 1
Key to Flags:
W (write), A (alloc), X (execute), M (merge), S (strings)
I (info), L (link order), G (group), x (unknown)
O (extra OS processing required) o (OS specific), p (processor specific)Code: Select all
void* module_loader::open(void* in_memory)
{
// Get byte array for module
unsigned char* module = reinterpret_cast<unsigned char*>(in_memory);
// Get ELF header
Elf32_Ehdr* header = reinterpret_cast<Elf32_Ehdr*>(module);
// Iterate through type-1 and type-8 sections to find module size,
// also find the symbol table.
unsigned int module_size = 0;
Elf32_Sym* symbol_table = nullptr;
for (unsigned int offset = header->e_shoff, index = 0;
index < header->e_shnum;
offset += header->e_shentsize, ++index)
{
// Get section header
Elf32_Shdr* section = reinterpret_cast<Elf32_Shdr*>(module + offset);
// If type-1 or type-8 add the size to the total
if (section->sh_type == 1 || section->sh_type == 8)
{
// Get size
unsigned int section_size = section->sh_size;
// Page-align it
if ((section_size % 0x1000) != 0)
{
section_size = (section_size & 0xFFFFF000) + 0x1000;
}
// Add to total size
module_size += section_size;
}
else if (section->sh_type == 2)
{
symbol_table = reinterpret_cast<Elf32_Sym*>(
module + section->sh_offset);
}
}
// Allocate pages
unsigned char* memory = reinterpret_cast<unsigned char*>(
indirect::allocator::instance().allocate(module_size / 0x1000));
// Iterate through once more and place program bits in memory
unsigned char* memory_last = memory;
unsigned char* memory_current = memory;
for (unsigned int offset = header->e_shoff, index = 0;
index < header->e_shnum;
offset += header->e_shentsize, ++index)
{
// Get section header
Elf32_Shdr* section = reinterpret_cast<Elf32_Shdr*>(module + offset);
switch (section->sh_type)
{
case 1: // Place program bits in memory
{
// Copy bits
std::memcpy(memory_current + section->sh_addr,
module + section->sh_offset, section->sh_size);
// Increment memory_current
memory_last = memory_current;
memory_current += section->sh_size;
} break;
case 8: // Null region ('.bss')
{
// Set memory
memory_current = memory + section->sh_addr;
// Null
std::memset(memory_current, 0, section->sh_size);
// Increment memory_current
memory_last = memory_current;
memory_current += section->sh_size;
} break;
case 9: // Apply relocations
{
// Get array
Elf32_Rel* reloc = reinterpret_cast<Elf32_Rel*>(
module + section->sh_offset);
Elf32_Rel* reloc_end = reinterpret_cast<Elf32_Rel*>(
module + section->sh_offset + section->sh_size);
while (reloc < reloc_end)
{
// Apply Relocation
unsigned int* address = reinterpret_cast<unsigned int*>(
memory_last + reloc->r_offset);
// Evaluate Relocation
switch (static_cast<unsigned char>(reloc->r_info))
{
case 1: // Symbol + Addend
{
(*address) =
symbol_table[reloc->r_info >> 8].st_value +
(*address);
} break;
case 2: // Symbol + Addend - Offset
{
(*address) =
symbol_table[reloc->r_info >> 8].st_value +
(*address) - reloc->r_offset;
} break;
default:
{
console::instance() << "Unhandled relocation type: "
<< (unsigned int)(unsigned char)(reloc->r_info)
<< '\n';
}
}
// Advance to next once
reloc = reinterpret_cast<Elf32_Rel*>(
reinterpret_cast<unsigned char*>(reloc) +
section->sh_entsize);
}
} break;
}
}
// Call entry point
unsigned int entry = reinterpret_cast<unsigned int>(memory) +
header->e_entry;
// Push begin and end for runtime, and call
unsigned char* memory_end = memory + module_size;
__asm__ ("movl %0, %%eax;"
"movl %1, %%ebx;"
: : "m" (memory_end), "m" (memory)
: "%eax", "%ebx");
reinterpret_cast<void (*)()>(entry)();
// Return module memory address
return reinterpret_cast<void*>(memory);
}
One of the many reasons I just love programming (much more so osdev): that barely describable feeling you get when the piece of code you've been working on for the last several hours or more to actually work. 
