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#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <libelf/gelf.h>
#include <libelfu/libelfu.h>
static ElfuScn* insertSection(ElfuElf *me, ElfuElf *mrel, ElfuScn *oldscn)
{
ElfuScn *newscn = NULL;
GElf_Addr injAddr;
GElf_Off injOffset;
ElfuPhdr *injPhdr;
if (oldscn->shdr.sh_flags & SHF_ALLOC) {
newscn = elfu_mCloneScn(oldscn);
if (!newscn) {
return NULL;
}
injAddr = elfu_mLayoutGetSpaceInPhdr(me,
newscn->shdr.sh_size,
newscn->shdr.sh_addralign,
newscn->shdr.sh_flags & SHF_WRITE,
newscn->shdr.sh_flags & SHF_EXECINSTR,
&injPhdr);
if (!injPhdr) {
ELFU_WARN("insertSection: Could not find a place to insert section.\n");
goto ERROR;
}
ELFU_INFO("Inserting %s at address 0x%jx...\n",
elfu_mScnName(mrel, oldscn),
injAddr);
injOffset = injAddr - injPhdr->phdr.p_vaddr + injPhdr->phdr.p_offset;
newscn->shdr.sh_addr = injAddr;
newscn->shdr.sh_offset = injOffset;
if (CIRCLEQ_EMPTY(&injPhdr->childScnList)
|| CIRCLEQ_LAST(&injPhdr->childScnList)->shdr.sh_offset < injOffset) {
CIRCLEQ_INSERT_TAIL(&injPhdr->childScnList, newscn, elemChildScn);
} else {
ElfuScn *ms;
CIRCLEQ_FOREACH(ms, &injPhdr->childScnList, elemChildScn) {
if (injOffset < ms->shdr.sh_offset) {
CIRCLEQ_INSERT_BEFORE(&injPhdr->childScnList, ms, newscn, elemChildScn);
break;
}
}
}
/* Inject name */
// TODO
newscn->shdr.sh_name = 0;
// TODO: Relocate
return newscn;
} else {
ELFU_WARN("insertSection: Skipping section %s with flags %jd (type %d).\n",
elfu_mScnName(mrel, oldscn),
oldscn->shdr.sh_flags,
oldscn->shdr.sh_type);
goto ERROR;
}
ERROR:
if (newscn) {
// TODO: Destroy newscn
}
return NULL;
}
int subScnAdd1(ElfuElf *mrel, ElfuScn *ms, void *aux1, void *aux2)
{
(void)aux2;
ElfuElf *me = (ElfuElf*)aux1;
ElfuScn *newscn;
switch(ms->shdr.sh_type) {
case SHT_PROGBITS: /* 1 */
/* Find a place where it belongs and shove it in. */
newscn = insertSection(me, mrel, ms);
if (!newscn) {
ELFU_WARN("mReladd: Could not insert section %s (type %d), skipping.\n",
elfu_mScnName(mrel, ms),
ms->shdr.sh_type);
}
break;
}
return 0;
}
int subScnAdd2(ElfuElf *mrel, ElfuScn *ms, void *aux1, void *aux2)
{
(void)aux2;
ElfuElf *me = (ElfuElf*)aux1;
(void)me;
switch(ms->shdr.sh_type) {
case SHT_NULL: /* 0 */
case SHT_PROGBITS: /* 1 */
break;
case SHT_SYMTAB: /* 2 */
case SHT_DYNSYM: /* 11 */
/* Merge with the existing table. Take care of string tables also. */
case SHT_STRTAB: /* 3 */
/* May have to be merged with the existing string table for
* the symbol table. */
case SHT_RELA: /* 4 */
case SHT_REL: /* 9 */
/* Possibly append this in memory to the section model
* that it describes. */
case SHT_NOBITS: /* 8 */
/* Expand this to SHT_PROGBITS, then insert as such. */
case SHT_HASH: /* 5 */
case SHT_DYNAMIC: /* 6 */
case SHT_SHLIB: /* 10 */
case SHT_SYMTAB_SHNDX: /* 18 */
/* Don't care about the next ones yet. I've never seen
* them and they can be implemented when necessary. */
case SHT_NOTE: /* 7 */
case SHT_INIT_ARRAY: /* 14 */
case SHT_FINI_ARRAY: /* 15 */
case SHT_PREINIT_ARRAY: /* 16 */
case SHT_GROUP: /* 17 */
case SHT_NUM: /* 19 */
default:
ELFU_WARN("mReladd: Skipping section %s (type %d).\n",
elfu_mScnName(mrel, ms),
ms->shdr.sh_type);
}
return 0;
}
void elfu_mReladd(ElfuElf *me, ElfuElf *mrel)
{
assert(me);
assert(mrel);
/* For each section in object file, guess how to insert it */
elfu_mScnForall(mrel, subScnAdd1, me, NULL);
/* Do relocations and other stuff */
elfu_mScnForall(mrel, subScnAdd2, me, NULL);
/* Re-layout to accommodate new contents */
elfu_mLayoutAuto(me);
}
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