#include <libelfu/libelfu.h>
-
-static GElf_Word makeSpaceAtOffset(ElfuElf *me, GElf_Off offset, GElf_Word size)
-{
- ElfuPhdr *mp;
- ElfuScn *ms;
- /* Force a minimum alignment, just to be sure. */
- GElf_Word align = 64;
-
- /* Find maximum alignment size by which we have to shift.
- * Assumes alignment sizes are always 2^x. */
- CIRCLEQ_FOREACH(mp, &me->phdrList, elem) {
- if (mp->phdr.p_offset >= offset) {
- if (mp->phdr.p_align > align) {
- align = mp->phdr.p_align;
- }
- }
- }
-
- CIRCLEQ_FOREACH(ms, &me->orphanScnList, elemChildScn) {
- if (ms->shdr.sh_offset >= offset) {
- if (ms->shdr.sh_addralign > align) {
- align = ms->shdr.sh_addralign;
- }
- }
- }
-
- size = ROUNDUP(size, align);
-
- /* Shift stuff */
- CIRCLEQ_FOREACH(mp, &me->phdrList, elem) {
- if (mp->phdr.p_type != PT_LOAD) {
- continue;
- }
-
- if (mp->phdr.p_offset >= offset) {
- ElfuScn *ms;
- ElfuPhdr *mpc;
-
- mp->phdr.p_offset += size;
- CIRCLEQ_FOREACH(mpc, &mp->childPhdrList, elemChildPhdr) {
- mpc->phdr.p_offset += size;
- }
- CIRCLEQ_FOREACH(ms, &mp->childScnList, elemChildScn) {
- ms->shdr.sh_offset += size;
- }
- }
- }
-
- CIRCLEQ_FOREACH(ms, &me->orphanScnList, elemChildScn) {
- if (ms->shdr.sh_offset >= offset) {
- ms->shdr.sh_offset += size;
- }
- }
-
- if (me->ehdr.e_phoff >= offset) {
- me->ehdr.e_phoff += size;
- }
-
- if (me->ehdr.e_shoff >= offset) {
- me->ehdr.e_shoff += size;
- }
-
- return size;
-}
-
-
-
-/* Finds a suitable PHDR to insert a hole into and expands it
- * if necessary.
- * Returns memory address the hole will be mapped to, or 0 if
- * the operation failed. */
-static GElf_Addr getSpaceInPhdr(ElfuElf *me, GElf_Word size,
- GElf_Word align, int w, int x,
- ElfuPhdr **injPhdr)
+static int appendData(ElfuScn *ms, void *buf, size_t len)
{
- ElfuPhdr *first = NULL;
- ElfuPhdr *last = NULL;
- ElfuPhdr *mp;
+ void *newbuf;
- assert(!(w && x));
+ assert(ms);
+ assert(ms->shdr.sh_type != SHT_NOBITS);
+ assert(ms->data.d_buf);
- /* Find first and last LOAD PHDRs.
- * Don't compare p_memsz - segments don't overlap in memory. */
- CIRCLEQ_FOREACH(mp, &me->phdrList, elem) {
- if (mp->phdr.p_type != PT_LOAD) {
- continue;
- }
- if (!first || mp->phdr.p_vaddr < first->phdr.p_vaddr) {
- first = mp;
- }
- if (!last || mp->phdr.p_vaddr > last->phdr.p_vaddr) {
- last = mp;
- }
+ newbuf = realloc(ms->data.d_buf, ms->shdr.sh_size + len);
+ if (!newbuf) {
+ ELFU_WARN("appendData: malloc() failed for newbuf.\n");
+ return 1;
}
- if ((w && (last->phdr.p_flags & PF_W))
- || (x && (last->phdr.p_flags & PF_X))) {
- /* Need to append. */
- GElf_Off injOffset = OFFS_END(last->phdr.p_offset, last->phdr.p_filesz);
- GElf_Word injSpace = 0;
- GElf_Word nobitsize = last->phdr.p_memsz - last->phdr.p_filesz;
-
- /* Expand NOBITS if any */
- if (nobitsize > 0) {
- GElf_Off endOff = OFFS_END(last->phdr.p_offset, last->phdr.p_filesz);
- GElf_Off endAddr = OFFS_END(last->phdr.p_vaddr, last->phdr.p_filesz);
- ElfuScn *ms;
-
- ELFU_INFO("Expanding NOBITS at address 0x%jx...\n", endAddr);
-
- CIRCLEQ_FOREACH(ms, &last->childScnList, elemChildScn) {
- if (ms->shdr.sh_offset == endOff) {
- assert(ms->shdr.sh_type == SHT_NOBITS);
- assert(ms->shdr.sh_size == nobitsize);
- ms->data.d_buf = malloc(ms->shdr.sh_size);
- memset(ms->data.d_buf, '\0', ms->shdr.sh_size);
- if (!ms->data.d_buf) {
- ELFU_WARN("mExpandNobits: Could not allocate %jd bytes for NOBITS expansion. Data may be inconsistent.\n", ms->shdr.sh_size);
- assert(0);
- goto ERROR;
- }
-
- ms->data.d_align = 1;
- ms->data.d_off = 0;
- ms->data.d_type = ELF_T_BYTE;
- ms->data.d_size = ms->shdr.sh_size;
- ms->data.d_version = elf_version(EV_NONE);
-
- ms->shdr.sh_type = SHT_PROGBITS;
- ms->shdr.sh_addr = endAddr;
- }
- }
-
- injSpace += makeSpaceAtOffset(me, endOff, nobitsize);
- injSpace -= nobitsize;
- injOffset += nobitsize;
- last->phdr.p_filesz += nobitsize;
- assert(last->phdr.p_filesz == last->phdr.p_memsz);
- }
-
- /* Calculate how much space we need, taking alignment into account */
- size += ROUNDUP(injOffset, align) - injOffset;
-
- /* If there is not enough space left, create even more. */
- if (injSpace < size) {
- injSpace += makeSpaceAtOffset(me, injOffset, size - injSpace);
- }
- assert(injSpace >= size);
-
- /* Remap ourselves */
- last->phdr.p_filesz += size;
- last->phdr.p_memsz += size;
-
- injOffset = ROUNDUP(injOffset, align);
-
- if (injPhdr) {
- *injPhdr = last;
- }
- return last->phdr.p_vaddr + (injOffset - last->phdr.p_offset);
- } else if ((w && (first->phdr.p_flags & PF_W))
- || (x && (first->phdr.p_flags & PF_X))) {
- /* Need to prepend or split up the PHDR. */
- GElf_Off injOffset = OFFS_END(first->phdr.p_offset, first->phdr.p_filesz);
- ElfuScn *ms;
-
- /* Round up size to take PHDR alignment into account.
- * We assume that this is a multiple of the alignment asked for. */
- assert(first->phdr.p_align >= align);
- size = ROUNDUP(size, first->phdr.p_align);
-
- /* Find first section. We assume there is at least one. */
- assert(!CIRCLEQ_EMPTY(&first->childScnList));
- injOffset = CIRCLEQ_FIRST(&first->childScnList)->shdr.sh_offset;
-
- /* Move our sections */
- CIRCLEQ_FOREACH(ms, &first->childScnList, elemChildScn) {
- if (ms->shdr.sh_offset >= injOffset) {
- ms->shdr.sh_offset += size;
- }
- }
-
- /* Move our PHDRs */
- CIRCLEQ_FOREACH(mp, &first->childPhdrList, elemChildPhdr) {
- if (mp->phdr.p_offset >= injOffset) {
- mp->phdr.p_offset += size;
- } else {
- mp->phdr.p_vaddr -= size;
- mp->phdr.p_paddr -= size;
- }
- }
-
- /* Move other PHDRs and sections */
- assert(size <= makeSpaceAtOffset(me, injOffset, size));
-
- /* Remap ourselves */
- first->phdr.p_vaddr -= size;
- first->phdr.p_paddr -= size;
- first->phdr.p_filesz += size;
- first->phdr.p_memsz += size;
-
- injOffset = ROUNDUP(injOffset, align);
-
- if (injPhdr) {
- *injPhdr = first;
- }
- return first->phdr.p_vaddr + (injOffset - first->phdr.p_offset);
- }
+ ms->data.d_buf = newbuf;
+ memcpy(newbuf + ms->shdr.sh_size, buf, len);
+ ms->shdr.sh_size += len;
+ ms->data.d_size += len;
+ assert(ms->shdr.sh_size == ms->data.d_size);
- ERROR:
- if (injPhdr) {
- *injPhdr = NULL;
- }
return 0;
}
-
-
static ElfuScn* insertSection(ElfuElf *me, ElfuElf *mrel, ElfuScn *oldscn)
{
ElfuScn *newscn = NULL;
}
- injAddr = getSpaceInPhdr(me, newscn->shdr.sh_size,
- newscn->shdr.sh_addralign,
- newscn->shdr.sh_flags & SHF_WRITE,
- newscn->shdr.sh_flags & SHF_EXECINSTR,
- &injPhdr);
+ 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");
}
}
+
/* Inject name */
- // TODO
- newscn->shdr.sh_name = 0;
+ if (me->shstrtab) {
+ char *newname;
+ size_t newnamelen;
+
+ newnamelen = strlen("reladd") + 1;
+ if (elfu_mScnName(mrel, oldscn)) {
+ newnamelen += strlen(elfu_mScnName(mrel, oldscn));
+ }
+
+ newname = malloc(newnamelen);
+ strcpy(newname, "reladd");
+ strcat(newname, elfu_mScnName(mrel, oldscn));
+
+ if (!newname) {
+ ELFU_WARN("insertSection: malloc() failed for newname. Leaving section name empty.\n");
+ newscn->shdr.sh_name = 0;
+ } else {
+ size_t offset = me->shstrtab->shdr.sh_size;
+
+ if (!appendData(me->shstrtab, newname, newnamelen)) {
+ newscn->shdr.sh_name = offset;
+ }
+
+ free(newname);
+ }
+ }
+
// TODO: Relocate
/* Do relocations and other stuff */
elfu_mScnForall(mrel, subScnAdd2, me, NULL);
+
+ /* Re-layout to accommodate new contents */
+ elfu_mLayoutAuto(me);
}
projects / centaur.git / blobdiff