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#include <assert.h>
#include <stdlib.h>
#include <libelfu/libelfu.h>
static GElf_Word symtabLookupVal(ElfuElf *metarget, ElfuScn *msst, GElf_Word entry)
{
GElf_Word i;
ElfuSym *sym;
assert(metarget);
assert(msst);
assert(msst->symtab);
assert(entry > 0);
assert(!CIRCLEQ_EMPTY(&msst->symtab->syms));
sym = CIRCLEQ_FIRST(&msst->symtab->syms);
for (i = 1; i < entry; i++) {
sym = CIRCLEQ_NEXT(sym, elem);
}
switch (sym->type) {
case STT_NOTYPE:
case STT_OBJECT:
case STT_FUNC:
if (sym->scnptr) {
assert(elfu_mScnByOldscn(metarget, sym->scnptr));
return elfu_mScnByOldscn(metarget, sym->scnptr)->shdr.sh_addr + sym->value;
} else {
// TODO: UNDEF, ABS, or COMMON
ELFU_WARN("symtabLookupVal: Returning 0 for UNDEF, ABS, or COMMON symbol.\n");
}
break;
case STT_SECTION:
assert(sym->scnptr);
assert(elfu_mScnByOldscn(metarget, sym->scnptr));
return elfu_mScnByOldscn(metarget, sym->scnptr)->shdr.sh_addr;
case STT_FILE:
// TODO
ELFU_WARN("symtabLookupVal: Returning 0 for FILE symbol.\n");
break;
default:
ELFU_WARN("symtabLookupVal: Unknown symbol type %d.\n", sym->type);
return 0;
}
}
void elfu_mRelocate32(ElfuElf *metarget, ElfuScn *mstarget, ElfuScn *msrt)
{
ElfuRel *rel;
assert(mstarget);
assert(msrt);
ELFU_DEBUG("Relocating in section of type %d size %jx\n",
mstarget->shdr.sh_type,
mstarget->shdr.sh_size);
CIRCLEQ_FOREACH(rel, &msrt->reltab->rels, elem) {
Elf32_Word *dest = (Elf32_Word*)(((char*)(mstarget->data.d_buf)) + rel->offset);
Elf32_Word a = rel->addendUsed ? rel->addend : *dest;
Elf32_Addr p = mstarget->shdr.sh_addr + rel->offset;
Elf32_Addr s = symtabLookupVal(metarget, msrt->linkptr, rel->sym);
Elf32_Word newval = *dest;
switch(rel->type) {
case R_386_NONE:
ELFU_DEBUG("Skipping relocation: R_386_NONE");
break;
case R_386_32:
ELFU_DEBUG("Relocation: R_386_32");
newval = s + a;
break;
case R_386_PC32:
ELFU_DEBUG("Relocation: R_386_PC32");
newval = s + a - p;
break;
default:
ELFU_DEBUG("Skipping relocation: Unknown type %d", rel->type);
}
ELFU_DEBUG(", overwriting %x with %x.\n", *dest, newval);
*dest = newval;
}
}
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