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t_elf64x86.c
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t_elf64x86.c
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/* $VER: vlink t_elf64x86.c V0.16d (28.02.20)
*
* This file is part of vlink, a portable linker for multiple
* object formats.
* Copyright (c) 1997-2020 Frank Wille
*/
#include "config.h"
#if defined(ELF64_X86)
#define T_ELF64X86_C
#include "vlink.h"
#include "elf64.h"
#include "rel_elfx86_64.h"
static int x86_64_identify(struct GlobalVars *,char *,uint8_t *,unsigned long,bool);
static void x86_64_readconv(struct GlobalVars *,struct LinkFile *);
static struct Symbol *x86_64_dynentry(struct GlobalVars *,DynArg,int);
static void x86_64_dyncreate(struct GlobalVars *);
static void x86_64_writeobject(struct GlobalVars *,FILE *);
static void x86_64_writeshared(struct GlobalVars *,FILE *);
static void x86_64_writeexec(struct GlobalVars *,FILE *);
struct FFFuncs fff_elf64x86 = {
"elf64x86",
NULL,
NULL,
NULL,
NULL,
elf64_headersize,
x86_64_identify,
x86_64_readconv,
NULL,
elf_targetlink,
NULL,
elf_lnksym,
elf_setlnksym,
elf64_initdynlink,
x86_64_dynentry,
x86_64_dyncreate,
x86_64_writeobject,
x86_64_writeshared,
x86_64_writeexec,
bss_name,sbss_name,
0x1000,
0, /* no small data support */
0,
0,
RTAB_ADDEND,RTAB_STANDARD|RTAB_ADDEND,
_LITTLE_ENDIAN_,
64,0
};
/*****************************************************************/
/* Read ELF */
/*****************************************************************/
static int x86_64_identify(struct GlobalVars *gv,char *name,uint8_t *p,
unsigned long plen,bool lib)
/* identify ELF-x86_64-LittleEndian */
{
return elf_identify(&fff_elf64x86,name,p,plen,
ELFCLASS64,ELFDATA2LSB,EM_X86_64,ELF_VER);
}
static uint8_t x86_64_reloc_elf2vlink(uint8_t rtype,struct RelocInsert *ri)
/* Determine vlink internal reloc type from ELF reloc type and fill in
reloc-insert description information.
All fields of the RelocInsert structure are preset to zero. */
{
/* Reloc conversion table for V.4-ABI */
static struct ELF2vlink convertV4[] = {
R_NONE,0,0,-1,
R_ABS,0,64,-1, /* R_X86_64_64 */
R_PC,0,32,-1, /* R_X86_64_PC32 */
R_GOT,0,32,-1, /* R_X86_64_GOT32 */
R_PLT,0,32,-1, /* R_X86_64_PLT32 */
R_COPY,0,64,-1, /* R_X86_64_COPY */
R_GLOBDAT,0,64,-1, /* R_X86_64_GLOB_DAT */
R_JMPSLOT,0,0,-1, /* R_X86_64_JUMP_SLOT */
R_LOADREL,0,64,-1, /* R_X86_64_RELATIVE */
R_GOTPC,0,32,-1, /* R_X86_64_GOTPCREL @@@ */
R_ABS,0,32,-1, /* R_X86_64_32 */
R_ABS,0,32,-1, /* R_X86_64_32S @@@ signed 32-bit? */
R_ABS,0,16,-1, /* R_X86_64_16 */
R_PC,0,16,-1, /* R_X86_64_PC16 */
R_ABS,0,8,-1, /* R_X86_64_8 */
R_PC,0,8,-1 /* R_X86_64_PC8 */
};
if (rtype <= R_X86_64_PC8) {
ri->bpos = convertV4[rtype].bpos;
ri->bsiz = convertV4[rtype].bsiz;
ri->mask = convertV4[rtype].mask;
rtype = convertV4[rtype].rtype;
}
else
rtype = R_NONE;
return rtype;
}
static void x86_64_readconv(struct GlobalVars *gv,struct LinkFile *lf)
/* Read ELF-x86_64 executable / object / shared obj. */
{
if (lf->type == ID_LIBARCH) {
struct ar_info ai;
if (ar_init(&ai,(char *)lf->data,lf->length,lf->filename)) {
while (ar_extract(&ai)) {
lf->objname = allocstring(ai.name);
if (elf_check_ar_type(fff[lf->format],lf->pathname,ai.data,
ELFCLASS64,ELFDATA2LSB,ELF_VER,1,EM_X86_64))
elf64_parse(gv,lf,(struct Elf64_Ehdr *)ai.data,x86_64_reloc_elf2vlink);
}
}
else
ierror("x86_64_readconv(): archive %s corrupted since last access",
lf->pathname);
}
else {
lf->objname = lf->filename;
elf64_parse(gv,lf,(struct Elf64_Ehdr *)lf->data,x86_64_reloc_elf2vlink);
}
}
static struct Symbol *x86_64_dynentry(struct GlobalVars *gv,DynArg a,int etype)
/* Create an entry into .got/.plt/.bss for the referenced symbol. */
{
struct Symbol *entry_sym = NULL;
struct Section *sec;
switch (etype) {
case GOT_ENTRY:
case GOT_LOCAL:
/* @@@ .got has ?? bytes reserved at the beginning,
is writable, a new entry occupies ? bytes. */
ierror("x86_64_dynentry(): GOT_ENTRY not yet written");
sec = elf_dyntable(gv,12,12,ST_DATA,SF_ALLOC,SP_READ|SP_WRITE,GOT_ENTRY);
entry_sym = elf64_pltgotentry(gv,sec,a,SYMI_OBJECT,4,4,etype);
break;
case PLT_ENTRY:
/* .got.plt has ?? bytes reserved at the beginning, is executable,
a new entry occupies another ?? bytes. */
ierror("x86_64_dynentry(): PLT_ENTRY not yet written");
sec = elf_dyntable(gv,16,16,ST_CODE,SF_ALLOC,SP_READ|SP_EXEC,PLT_ENTRY);
entry_sym = elf64_pltgotentry(gv,sec,a,SYMI_FUNC,16,16,PLT_ENTRY);
break;
case BSS_ENTRY:
/* @@@ */
ierror("x86_64_dynentry(): BSS_ENTRY not yet written");
break;
default:
ierror("x86_64_dynentry(): illegal entrytype: %d",etype);
break;
}
return entry_sym;
}
static void x86_64_dyncreate(struct GlobalVars *gv)
{
elf64_dyncreate(gv,got_name);
}
/*****************************************************************/
/* Write ELF */
/*****************************************************************/
static uint8_t x86_64_reloc_vlink2elf(struct Reloc *r)
/* Try to map vlink-internal representation to a valid ELF reloc type */
{
if (isstdreloc(r,R_ABS,8)) return R_X86_64_8;
else if (isstdreloc(r,R_ABS,16)) return R_X86_64_16;
else if (isstdreloc(r,R_ABS,32)) return R_X86_64_32;
else if (isstdreloc(r,R_ABS,64)) return R_X86_64_64;
else if (isstdreloc(r,R_PC,8)) return R_X86_64_PC8;
else if (isstdreloc(r,R_PC,16)) return R_X86_64_PC16;
else if (isstdreloc(r,R_PC,32)) return R_X86_64_PC32;
else if (isstdreloc(r,R_GOT,32)) return R_X86_64_GOT32;
else if (isstdreloc(r,R_GOTPC,32)) return R_X86_64_GOTPCREL; /* @@@ */
else if (isstdreloc(r,R_PLT,32)) return R_X86_64_PLT32;
else if (r->rtype == R_COPY) return R_X86_64_COPY;
else if (r->rtype == R_GLOBDAT) return R_X86_64_GLOB_DAT;
else if (r->rtype == R_JMPSLOT) return R_X86_64_JUMP_SLOT;
else if (r->rtype == R_LOADREL) return R_X86_64_RELATIVE;
return R_NONE;
}
static void x86_64_writeshared(struct GlobalVars *gv,FILE *f)
/* creates a target-elf32i386 shared object (which is pos. independent) */
{
ierror("x86_64_writeshared(): Shared object generation has not "
"yet been implemented");
}
static void x86_64_writeobject(struct GlobalVars *gv,FILE *f)
/* creates a target-elf32i386 relocatable object file */
{
elf64_writeobject(gv,f,EM_X86_64,_LITTLE_ENDIAN_,x86_64_reloc_vlink2elf);
}
static void x86_64_writeexec(struct GlobalVars *gv,FILE *f)
/* creates a target-elf32i386 executable file (with absolute addresses) */
{
elf64_writeexec(gv,f,EM_X86_64,_LITTLE_ENDIAN_,x86_64_reloc_vlink2elf);
}
#endif /* ELF64_X86 */