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ld: reading of ELF object files
R=iant CC=golang-dev https://golang.org/cl/3507041
This commit is contained in:
Russ Cox
parent
7431a3165e
commit
4d8d6d5cda
822
src/cmd/ld/ldelf.c
Normal file
822
src/cmd/ld/ldelf.c
Normal file
@ -0,0 +1,822 @@
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/*
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Derived from Plan 9 from User Space's src/libmach/elf.h, elf.c
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http://code.swtch.com/plan9port/src/tip/src/libmach/
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Copyright © 2004 Russ Cox.
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Portions Copyright © 2008-2010 Google Inc.
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Portions Copyright © 2010 The Go Authors.
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Permission is hereby granted, free of charge, to any person obtaining a copy
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of this software and associated documentation files (the "Software"), to deal
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in the Software without restriction, including without limitation the rights
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to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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copies of the Software, and to permit persons to whom the Software is
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furnished to do so, subject to the following conditions:
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The above copyright notice and this permission notice shall be included in
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all copies or substantial portions of the Software.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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THE SOFTWARE.
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*/
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#include "l.h"
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#include "lib.h"
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#include "../ld/elf.h"
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enum
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{
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ElfClassNone = 0,
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ElfClass32,
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ElfClass64,
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ElfDataNone = 0,
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ElfDataLsb,
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ElfDataMsb,
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ElfTypeNone = 0,
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ElfTypeRelocatable,
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ElfTypeExecutable,
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ElfTypeSharedObject,
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ElfTypeCore,
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/* 0xFF00 - 0xFFFF reserved for processor-specific types */
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ElfMachNone = 0,
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ElfMach32100, /* AT&T WE 32100 */
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ElfMachSparc, /* SPARC */
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ElfMach386, /* Intel 80386 */
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ElfMach68000, /* Motorola 68000 */
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ElfMach88000, /* Motorola 88000 */
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ElfMach486, /* Intel 80486, no longer used */
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ElfMach860, /* Intel 80860 */
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ElfMachMips, /* MIPS RS3000 */
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ElfMachS370, /* IBM System/370 */
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ElfMachMipsLe, /* MIPS RS3000 LE */
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ElfMachParisc = 15, /* HP PA RISC */
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ElfMachVpp500 = 17, /* Fujitsu VPP500 */
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ElfMachSparc32Plus, /* SPARC V8+ */
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ElfMach960, /* Intel 80960 */
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ElfMachPower, /* PowerPC */
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ElfMachPower64, /* PowerPC 64 */
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ElfMachS390, /* IBM System/390 */
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ElfMachV800 = 36, /* NEC V800 */
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ElfMachFr20, /* Fujitsu FR20 */
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ElfMachRh32, /* TRW RH-32 */
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ElfMachRce, /* Motorola RCE */
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ElfMachArm, /* ARM */
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ElfMachAlpha, /* Digital Alpha */
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ElfMachSH, /* Hitachi SH */
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ElfMachSparc9, /* SPARC V9 */
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ElfMachAmd64 = 62,
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/* and the list goes on... */
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ElfAbiNone = 0,
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ElfAbiSystemV = 0, /* [sic] */
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ElfAbiHPUX,
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ElfAbiNetBSD,
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ElfAbiLinux,
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ElfAbiSolaris = 6,
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ElfAbiAix,
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ElfAbiIrix,
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ElfAbiFreeBSD,
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ElfAbiTru64,
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ElfAbiModesto,
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ElfAbiOpenBSD,
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ElfAbiARM = 97,
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ElfAbiEmbedded = 255,
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/* some of sections 0xFF00 - 0xFFFF reserved for various things */
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ElfSectNone = 0,
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ElfSectProgbits,
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ElfSectSymtab,
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ElfSectStrtab,
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ElfSectRela,
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ElfSectHash,
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ElfSectDynamic,
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ElfSectNote,
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ElfSectNobits,
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ElfSectRel,
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ElfSectShlib,
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ElfSectDynsym,
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ElfSectFlagWrite = 0x1,
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ElfSectFlagAlloc = 0x2,
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ElfSectFlagExec = 0x4,
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/* 0xF0000000 are reserved for processor specific */
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ElfSymBindLocal = 0,
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ElfSymBindGlobal,
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ElfSymBindWeak,
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/* 13-15 reserved */
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ElfSymTypeNone = 0,
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ElfSymTypeObject,
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ElfSymTypeFunc,
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ElfSymTypeSection,
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ElfSymTypeFile,
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/* 13-15 reserved */
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ElfSymShnNone = 0,
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ElfSymShnAbs = 0xFFF1,
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ElfSymShnCommon = 0xFFF2,
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/* 0xFF00-0xFF1F reserved for processors */
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/* 0xFF20-0xFF3F reserved for operating systems */
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ElfProgNone = 0,
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ElfProgLoad,
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ElfProgDynamic,
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ElfProgInterp,
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ElfProgNote,
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ElfProgShlib,
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ElfProgPhdr,
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ElfProgFlagExec = 0x1,
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ElfProgFlagWrite = 0x2,
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ElfProgFlagRead = 0x4,
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ElfNotePrStatus = 1,
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ElfNotePrFpreg = 2,
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ElfNotePrPsinfo = 3,
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ElfNotePrTaskstruct = 4,
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ElfNotePrAuxv = 6,
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ElfNotePrXfpreg = 0x46e62b7f /* for gdb/386 */
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};
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typedef struct ElfHdrBytes ElfHdrBytes;
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typedef struct ElfSectBytes ElfSectBytes;
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typedef struct ElfProgBytes ElfProgBytes;
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typedef struct ElfSymBytes ElfSymBytes;
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typedef struct ElfHdrBytes64 ElfHdrBytes64;
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typedef struct ElfSectBytes64 ElfSectBytes64;
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typedef struct ElfProgBytes64 ElfProgBytes64;
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typedef struct ElfSymBytes64 ElfSymBytes64;
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struct ElfHdrBytes
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{
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uchar ident[16];
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uchar type[2];
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uchar machine[2];
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uchar version[4];
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uchar entry[4];
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uchar phoff[4];
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uchar shoff[4];
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uchar flags[4];
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uchar ehsize[2];
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uchar phentsize[2];
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uchar phnum[2];
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uchar shentsize[2];
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uchar shnum[2];
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uchar shstrndx[2];
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};
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struct ElfHdrBytes64
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{
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uchar ident[16];
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uchar type[2];
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uchar machine[2];
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uchar version[4];
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uchar entry[8];
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uchar phoff[8];
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uchar shoff[8];
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uchar flags[4];
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uchar ehsize[2];
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uchar phentsize[2];
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uchar phnum[2];
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uchar shentsize[2];
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uchar shnum[2];
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uchar shstrndx[2];
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};
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struct ElfSectBytes
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{
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uchar name[4];
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uchar type[4];
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uchar flags[4];
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uchar addr[4];
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uchar off[4];
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uchar size[4];
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uchar link[4];
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uchar info[4];
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uchar align[4];
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uchar entsize[4];
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};
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struct ElfSectBytes64
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{
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uchar name[4];
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uchar type[4];
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uchar flags[8];
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uchar addr[8];
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uchar off[8];
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uchar size[8];
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uchar link[4];
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uchar info[4];
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uchar align[8];
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uchar entsize[8];
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};
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struct ElfSymBytes
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{
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uchar name[4];
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uchar value[4];
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uchar size[4];
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uchar info; /* top4: bind, bottom4: type */
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uchar other;
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uchar shndx[2];
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};
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struct ElfSymBytes64
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{
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uchar name[4];
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uchar info; /* top4: bind, bottom4: type */
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uchar other;
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uchar shndx[2];
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uchar value[8];
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uchar size[8];
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};
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typedef struct ElfSect ElfSect;
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typedef struct ElfObj ElfObj;
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typedef struct ElfSym ElfSym;
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struct ElfSect
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{
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char *name;
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uint32 type;
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uint64 flags;
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uint64 addr;
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uint64 off;
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uint64 size;
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uint32 link;
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uint32 info;
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uint64 align;
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uint64 entsize;
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uchar *base;
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Sym *sym;
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};
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struct ElfObj
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{
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Biobuf *f;
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int64 base; // offset in f where ELF begins
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int64 len; // length of ELF
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int is64;
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char *name;
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Endian *e;
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ElfSect *sect;
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uint nsect;
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char *shstrtab;
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int nsymtab;
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ElfSect *symtab;
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ElfSect *symstr;
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uint32 type;
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uint32 machine;
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uint32 version;
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uint64 entry;
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uint64 phoff;
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uint64 shoff;
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uint32 flags;
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uint32 ehsize;
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uint32 phentsize;
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uint32 phnum;
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uint32 shentsize;
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uint32 shnum;
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uint32 shstrndx;
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};
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struct ElfSym
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{
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char* name;
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uint64 value;
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uint64 size;
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uchar bind;
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uchar type;
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uchar other;
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uint16 shndx;
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Sym* sym;
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};
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uchar ElfMagic[4] = { 0x7F, 'E', 'L', 'F' };
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static ElfSect* section(ElfObj*, char*);
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static int map(ElfObj*, ElfSect*);
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static int readsym(ElfObj*, int i, ElfSym*);
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static int reltype(char*, int, uchar*);
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void
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ldelf(Biobuf *f, char *pkg, int64 len, char *pn)
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{
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int32 base;
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uint64 add, info;
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char *name;
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int i, j, rela, is64, n;
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uchar hdrbuf[64];
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uchar *p, *dp;
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ElfHdrBytes *hdr;
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ElfObj *obj;
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ElfSect *sect, *rsect, *text, *data, *bss, *rodata;
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ElfSym sym;
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Endian *e;
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Reloc *r, *rp;
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Sym *s;
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if(debug['v'])
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Bprint(&bso, "%5.2f ldelf %s\n", cputime(), pn);
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version++;
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base = Boffset(f);
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if(Bread(f, &hdrbuf, sizeof hdrbuf) != sizeof hdrbuf)
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goto bad;
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hdr = (ElfHdrBytes*)&hdrbuf;
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if(memcmp(hdr->ident, ElfMagic, 4) != 0)
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goto bad;
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switch(hdr->ident[5]) {
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case ElfDataLsb:
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e = ≤
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break;
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case ElfDataMsb:
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e = &be;
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break;
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default:
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goto bad;
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}
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// read header
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obj = mal(sizeof *obj);
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obj->e = e;
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obj->f = f;
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obj->base = base;
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obj->len = len;
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obj->name = pn;
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is64 = 0;
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if(hdr->ident[4] == ElfClass64) {
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ElfHdrBytes64* hdr;
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is64 = 1;
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hdr = (ElfHdrBytes64*)hdrbuf;
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obj->type = e->e16(hdr->type);
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obj->machine = e->e16(hdr->machine);
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obj->version = e->e32(hdr->version);
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obj->phoff = e->e64(hdr->phoff);
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obj->shoff = e->e64(hdr->shoff);
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obj->flags = e->e32(hdr->flags);
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obj->ehsize = e->e16(hdr->ehsize);
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obj->phentsize = e->e16(hdr->phentsize);
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obj->phnum = e->e16(hdr->phnum);
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obj->shentsize = e->e16(hdr->shentsize);
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obj->shnum = e->e16(hdr->shnum);
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obj->shstrndx = e->e16(hdr->shstrndx);
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} else {
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obj->type = e->e16(hdr->type);
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obj->machine = e->e16(hdr->machine);
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obj->version = e->e32(hdr->version);
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obj->entry = e->e32(hdr->entry);
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obj->phoff = e->e32(hdr->phoff);
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obj->shoff = e->e32(hdr->shoff);
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obj->flags = e->e32(hdr->flags);
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obj->ehsize = e->e16(hdr->ehsize);
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obj->phentsize = e->e16(hdr->phentsize);
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obj->phnum = e->e16(hdr->phnum);
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obj->shentsize = e->e16(hdr->shentsize);
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obj->shnum = e->e16(hdr->shnum);
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obj->shstrndx = e->e16(hdr->shstrndx);
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}
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obj->is64 = is64;
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if(hdr->ident[6] != obj->version)
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goto bad;
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if(e->e16(hdr->type) != ElfTypeRelocatable) {
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diag("%s: elf but not elf relocatable object");
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return;
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}
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switch(thechar) {
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default:
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diag("%s: elf %s unimplemented", thestring);
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return;
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case '5':
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if(e != &le || obj->machine != ElfMachArm || hdr->ident[4] != ElfClass32) {
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diag("%s: elf object but not arm", pn);
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return;
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}
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break;
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case '6':
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if(e != &le || obj->machine != ElfMachAmd64 || hdr->ident[4] != ElfClass64) {
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diag("%s: elf object but not amd64", pn);
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return;
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}
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break;
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case '8':
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if(e != &le || obj->machine != ElfMach386 || hdr->ident[4] != ElfClass32) {
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diag("%s: elf object but not 386", pn);
|
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return;
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}
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break;
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}
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// load section list into memory.
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obj->sect = mal(obj->shnum*sizeof obj->sect[0]);
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obj->nsect = obj->shnum;
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for(i=0; i<obj->nsect; i++) {
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if(Bseek(f, base+obj->shoff+i*obj->shentsize, 0) < 0)
|
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goto bad;
|
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sect = &obj->sect[i];
|
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if(is64) {
|
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ElfSectBytes64 b;
|
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|
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werrstr("short read");
|
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if(Bread(f, &b, sizeof b) != sizeof b)
|
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goto bad;
|
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|
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sect->name = (char*)(uintptr)e->e32(b.name);
|
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sect->type = e->e32(b.type);
|
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sect->flags = e->e64(b.flags);
|
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sect->addr = e->e64(b.addr);
|
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sect->off = e->e64(b.off);
|
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sect->size = e->e64(b.size);
|
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sect->link = e->e32(b.link);
|
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sect->info = e->e32(b.info);
|
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sect->align = e->e64(b.align);
|
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sect->entsize = e->e64(b.entsize);
|
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} else {
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ElfSectBytes b;
|
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|
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werrstr("short read");
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if(Bread(f, &b, sizeof b) != sizeof b)
|
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goto bad;
|
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|
||||
sect->name = (char*)(uintptr)e->e32(b.name);
|
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sect->type = e->e32(b.type);
|
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sect->flags = e->e32(b.flags);
|
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sect->addr = e->e32(b.addr);
|
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sect->off = e->e32(b.off);
|
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sect->size = e->e32(b.size);
|
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sect->link = e->e32(b.link);
|
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sect->info = e->e32(b.info);
|
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sect->align = e->e32(b.align);
|
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sect->entsize = e->e32(b.entsize);
|
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}
|
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}
|
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|
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// read section string table and translate names
|
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if(obj->shstrndx >= obj->nsect) {
|
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werrstr("shstrndx out of range %d >= %d", obj->shstrndx, obj->nsect);
|
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goto bad;
|
||||
}
|
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sect = &obj->sect[obj->shstrndx];
|
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if(map(obj, sect) < 0)
|
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goto bad;
|
||||
for(i=0; i<obj->nsect; i++)
|
||||
if(obj->sect[i].name != nil)
|
||||
obj->sect[i].name = (char*)sect->base + (uintptr)obj->sect[i].name;
|
||||
|
||||
// load string table for symbols into memory.
|
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obj->symtab = section(obj, ".symtab");
|
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if(obj->symtab == nil) {
|
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diag("%s: elf object has no symbol table", pn);
|
||||
return;
|
||||
}
|
||||
if(obj->symtab->link <= 0 || obj->symtab->link >= obj->nsect) {
|
||||
diag("%s: elf object has symbol table with invalid string table link", pn);
|
||||
return;
|
||||
}
|
||||
obj->symstr = &obj->sect[obj->symtab->link];
|
||||
if(is64)
|
||||
obj->nsymtab = obj->symtab->size / sizeof(ElfSymBytes64);
|
||||
else
|
||||
obj->nsymtab = obj->symtab->size / sizeof(ElfSymBytes);
|
||||
|
||||
if(map(obj, obj->symtab) < 0)
|
||||
goto bad;
|
||||
if(map(obj, obj->symstr) < 0)
|
||||
goto bad;
|
||||
|
||||
// load text and data segments into memory.
|
||||
// they are not as small as the section lists, but we'll need
|
||||
// the memory anyway for the symbol images, so we might
|
||||
// as well use one large chunk.
|
||||
text = section(obj, ".text");
|
||||
if(text && map(obj, text) < 0)
|
||||
goto bad;
|
||||
data = section(obj, ".data");
|
||||
if(data && map(obj, data) < 0)
|
||||
goto bad;
|
||||
bss = section(obj, ".bss");
|
||||
rodata = section(obj, ".rodata");
|
||||
if(rodata && map(obj, rodata) < 0)
|
||||
goto bad;
|
||||
|
||||
// create symbols for mapped sections
|
||||
for(i=0; i<obj->nsect; i++) {
|
||||
sect = &obj->sect[i];
|
||||
if(sect->type != ElfSectProgbits || !(sect->flags&ElfSectFlagAlloc))
|
||||
continue;
|
||||
if(map(obj, sect) < 0)
|
||||
goto bad;
|
||||
|
||||
name = smprint("%s(%s)", pn, sect->name);
|
||||
s = lookup(name, version);
|
||||
free(name);
|
||||
switch(sect->flags&(ElfSectFlagAlloc|ElfSectFlagWrite|ElfSectFlagExec)) {
|
||||
default:
|
||||
werrstr("unexpected flags for ELF section %s", sect->name);
|
||||
goto bad;
|
||||
case ElfSectFlagAlloc:
|
||||
s->type = SRODATA;
|
||||
break;
|
||||
case ElfSectFlagAlloc + ElfSectFlagWrite:
|
||||
s->type = SDATA;
|
||||
break;
|
||||
case ElfSectFlagAlloc + ElfSectFlagExec:
|
||||
s->type = STEXT;
|
||||
break;
|
||||
}
|
||||
s->p = sect->base;
|
||||
s->np = sect->size;
|
||||
s->size = sect->size;
|
||||
if(s->type == STEXT) {
|
||||
if(etextp)
|
||||
etextp->next = s;
|
||||
else
|
||||
textp = s;
|
||||
etextp = s;
|
||||
}
|
||||
sect->sym = s;
|
||||
}
|
||||
|
||||
// load relocations
|
||||
for(i=0; i<obj->nsect; i++) {
|
||||
rsect = &obj->sect[i];
|
||||
if(rsect->type != ElfSectRela && rsect->type != ElfSectRel)
|
||||
continue;
|
||||
if(rsect->info >= obj->nsect || obj->sect[rsect->info].base == nil)
|
||||
continue;
|
||||
sect = &obj->sect[rsect->info];
|
||||
if(map(obj, rsect) < 0)
|
||||
goto bad;
|
||||
rela = rsect->type == ElfSectRela;
|
||||
n = rsect->size/(4+4*is64)/(2+rela);
|
||||
r = mal(n*sizeof r[0]);
|
||||
p = rsect->base;
|
||||
dp = sect->base;
|
||||
for(j=0; j<n; j++) {
|
||||
add = 0;
|
||||
rp = &r[j];
|
||||
if(is64) {
|
||||
// 64-bit rel/rela
|
||||
rp->off = e->e64(p);
|
||||
p += 8;
|
||||
info = e->e64(p);
|
||||
p += 8;
|
||||
if(rela) {
|
||||
add = e->e64(p);
|
||||
p += 8;
|
||||
}
|
||||
} else {
|
||||
// 32-bit rel/rela
|
||||
rp->off = e->e32(p);
|
||||
p += 4;
|
||||
info = e->e32(p);
|
||||
info = info>>8<<32 | (info&0xff); // convert to 64-bit info
|
||||
p += 4;
|
||||
if(rela) {
|
||||
add = e->e32(p);
|
||||
p += 4;
|
||||
}
|
||||
}
|
||||
if(readsym(obj, info>>32, &sym) < 0)
|
||||
goto bad;
|
||||
if(sym.sym == nil) {
|
||||
werrstr("reloc of invalid sym %s shndx=%d type=%d", sym.name, sym.shndx, sym.type);
|
||||
goto bad;
|
||||
}
|
||||
rp->sym = sym.sym;
|
||||
rp->type = reltype(pn, (uint32)info, &rp->siz);
|
||||
if(rela)
|
||||
rp->add = add;
|
||||
else {
|
||||
// load addend from image
|
||||
if(rp->siz == 4)
|
||||
rp->add = e->e32(sect->base+rp->off);
|
||||
else if(rp->siz == 8)
|
||||
rp->add = e->e64(sect->base+rp->off);
|
||||
else
|
||||
diag("invalid rela size %d", rp->siz);
|
||||
}
|
||||
}
|
||||
qsort(r, n, sizeof r[0], rbyoff); // just in case
|
||||
|
||||
s = sect->sym;
|
||||
s->r = r;
|
||||
s->nr = n;
|
||||
}
|
||||
|
||||
// enter sub-symbols into symbol table.
|
||||
// symbol 0 is the null symbol.
|
||||
for(i=1; i<obj->nsymtab; i++) {
|
||||
if(readsym(obj, i, &sym) < 0)
|
||||
goto bad;
|
||||
if(sym.type != ElfSymTypeFunc && sym.type != ElfSymTypeObject && sym.type != ElfSymTypeNone)
|
||||
continue;
|
||||
if(sym.shndx == ElfSymShnCommon) {
|
||||
s = sym.sym;
|
||||
if(s->size < sym.size)
|
||||
s->size = sym.size;
|
||||
if(s->type == 0 || s->type == SXREF)
|
||||
s->type = SBSS;
|
||||
continue;
|
||||
}
|
||||
if(sym.shndx >= obj->nsect || sym.shndx == 0)
|
||||
continue;
|
||||
sect = obj->sect+sym.shndx;
|
||||
if(sect->sym == nil) {
|
||||
diag("%s: sym#%d: ignoring %s in section %d (type %d)", pn, i, sym.name, sym.shndx, sym.type);
|
||||
continue;
|
||||
}
|
||||
s = sym.sym;
|
||||
s->sub = sect->sym->sub;
|
||||
sect->sym->sub = s;
|
||||
s->type = sect->sym->type | SSUB;
|
||||
s->dynimplib = nil; // satisfy dynimport
|
||||
s->dynimpname = nil; // satisfy dynimport
|
||||
s->value = sym.value;
|
||||
s->size = sym.size;
|
||||
s->outer = sect->sym;
|
||||
if(sect->sym->type == STEXT) {
|
||||
Prog *p;
|
||||
|
||||
if(s->text != P)
|
||||
diag("%s: duplicate definition of %s", pn, s->name);
|
||||
// build a TEXT instruction with a unique pc
|
||||
// just to make the rest of the linker happy.
|
||||
// TODO: this is too 6l-specific ?
|
||||
p = prg();
|
||||
p->as = ATEXT;
|
||||
p->from.type = D_EXTERN;
|
||||
p->from.sym = s;
|
||||
p->from.scale = 7;
|
||||
p->to.type = D_CONST;
|
||||
p->link = nil;
|
||||
p->pc = pc++;
|
||||
s->text = p;
|
||||
|
||||
etextp->next = s;
|
||||
etextp = s;
|
||||
}
|
||||
}
|
||||
return;
|
||||
|
||||
bad:
|
||||
diag("%s: malformed elf file: %r", pn);
|
||||
}
|
||||
|
||||
static ElfSect*
|
||||
section(ElfObj *obj, char *name)
|
||||
{
|
||||
int i;
|
||||
|
||||
for(i=0; i<obj->nsect; i++)
|
||||
if(obj->sect[i].name && name && strcmp(obj->sect[i].name, name) == 0)
|
||||
return &obj->sect[i];
|
||||
return nil;
|
||||
}
|
||||
|
||||
static int
|
||||
map(ElfObj *obj, ElfSect *sect)
|
||||
{
|
||||
if(sect->base != nil)
|
||||
return 0;
|
||||
|
||||
if(sect->off+sect->size > obj->len) {
|
||||
werrstr("elf section past end of file");
|
||||
return -1;
|
||||
}
|
||||
|
||||
sect->base = mal(sect->size);
|
||||
werrstr("short read");
|
||||
if(Bseek(obj->f, obj->base+sect->off, 0) < 0 || Bread(obj->f, sect->base, sect->size) != sect->size)
|
||||
return -1;
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int
|
||||
readsym(ElfObj *obj, int i, ElfSym *sym)
|
||||
{
|
||||
Sym *s;
|
||||
|
||||
if(i >= obj->nsymtab || i < 0) {
|
||||
werrstr("invalid elf symbol index");
|
||||
return -1;
|
||||
}
|
||||
|
||||
if(obj->is64) {
|
||||
ElfSymBytes64 *b;
|
||||
|
||||
b = (ElfSymBytes64*)(obj->symtab->base + i*sizeof *b);
|
||||
sym->name = (char*)obj->symstr->base + obj->e->e32(b->name);
|
||||
sym->value = obj->e->e64(b->value);
|
||||
sym->size = obj->e->e64(b->size);
|
||||
sym->shndx = obj->e->e16(b->shndx);
|
||||
sym->bind = b->info>>4;
|
||||
sym->type = b->info&0xf;
|
||||
sym->other = b->other;
|
||||
} else {
|
||||
ElfSymBytes *b;
|
||||
|
||||
b = (ElfSymBytes*)(obj->symtab->base + i*sizeof *b);
|
||||
sym->name = (char*)obj->symstr->base + obj->e->e32(b->name);
|
||||
sym->value = obj->e->e32(b->value);
|
||||
sym->size = obj->e->e32(b->size);
|
||||
sym->shndx = obj->e->e16(b->shndx);
|
||||
sym->bind = b->info>>4;
|
||||
sym->type = b->info&0xf;
|
||||
sym->other = b->other;
|
||||
}
|
||||
|
||||
s = nil;
|
||||
if(strcmp(sym->name, "_GLOBAL_OFFSET_TABLE_") == 0)
|
||||
sym->name = ".got";
|
||||
if(strcmp(sym->name, "__stack_chk_fail_local") == 0)
|
||||
sym->other = 0; // rewrite hidden -> default visibility
|
||||
switch(sym->type) {
|
||||
case ElfSymTypeSection:
|
||||
s = obj->sect[sym->shndx].sym;
|
||||
break;
|
||||
case ElfSymTypeObject:
|
||||
case ElfSymTypeFunc:
|
||||
case ElfSymTypeNone:
|
||||
switch(sym->bind) {
|
||||
case ElfSymBindGlobal:
|
||||
if(sym->other != 2) {
|
||||
s = lookup(sym->name, 0);
|
||||
break;
|
||||
}
|
||||
// fall through
|
||||
case ElfSymBindLocal:
|
||||
s = lookup(sym->name, version);
|
||||
break;
|
||||
default:
|
||||
werrstr("%s: invalid symbol binding %d", sym->name, sym->bind);
|
||||
return -1;
|
||||
}
|
||||
break;
|
||||
}
|
||||
if(s != nil && s->type == 0 && sym->type != ElfSymTypeSection)
|
||||
s->type = SXREF;
|
||||
sym->sym = s;
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
int
|
||||
rbyoff(const void *va, const void *vb)
|
||||
{
|
||||
Reloc *a, *b;
|
||||
|
||||
a = (Reloc*)va;
|
||||
b = (Reloc*)vb;
|
||||
if(a->off < b->off)
|
||||
return -1;
|
||||
if(a->off > b->off)
|
||||
return +1;
|
||||
return 0;
|
||||
}
|
||||
|
||||
#define R(x, y) ((x)|((y)<<24))
|
||||
|
||||
static int
|
||||
reltype(char *pn, int elftype, uchar *siz)
|
||||
{
|
||||
switch(R(thechar, elftype)) {
|
||||
default:
|
||||
diag("%s: unknown relocation type %d; compiled without -fpic?", pn, elftype);
|
||||
case R('6', R_X86_64_PC32):
|
||||
case R('6', R_X86_64_PLT32):
|
||||
case R('6', R_X86_64_GOTPCREL):
|
||||
case R('8', R_386_32):
|
||||
case R('8', R_386_PC32):
|
||||
case R('8', R_386_GOT32):
|
||||
case R('8', R_386_PLT32):
|
||||
case R('8', R_386_GOTOFF):
|
||||
case R('8', R_386_GOTPC):
|
||||
*siz = 4;
|
||||
break;
|
||||
case R('6', R_X86_64_64):
|
||||
*siz = 8;
|
||||
break;
|
||||
}
|
||||
|
||||
return 256+elftype;
|
||||
}
|
||||
Loading…
Reference in New Issue
Block a user