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#include <stdio.h>
#include <libelf.h>
#include <gelf.h>
#include <libelfu/libelfu.h>
void elfu_copySegments1(Elf *eo, Elf *ei)
{
size_t i, n;
if (elf_getphdrnum(ei, &n)) {
fprintf(stderr, "elf_getphdrnum() failed: %s\n", elf_errmsg(-1));
}
if (!gelf_newphdr(eo, n)) {
fprintf(stderr, "gelf_newphdr() failed: %s\n", elf_errmsg(-1));
}
for (i = 0; i < n; i++) {
GElf_Phdr phdr, phdrOut;
if (gelf_getphdr(ei, i, &phdr) != &phdr) {
fprintf(stderr, "gelf_getphdr() failed for #%d: %s\n", i, elf_errmsg(-1));
break;
}
if (gelf_getphdr(eo, i, &phdrOut) != &phdrOut) {
fprintf(stderr, "gelf_getphdr() failed for #%d: %s\n", i, elf_errmsg(-1));
break;
}
phdrOut.p_type = phdr.p_type;
/* p_offset */
phdrOut.p_vaddr = phdr.p_vaddr;
phdrOut.p_paddr = phdr.p_paddr;
/* p_filesz */
/* p_memsz */
phdrOut.p_flags = phdr.p_flags;
phdrOut.p_align = phdr.p_align;
if (!gelf_update_phdr (eo, i, &phdrOut)) {
fprintf(stderr, "gelf_update_ehdr() failed: %s\n", elf_errmsg(-1));
}
}
/* Tell libelf that phdrs have changed */
elf_flagphdr(eo, ELF_C_SET, ELF_F_DIRTY);
}
void elfu_copySegments2(Elf *eo, Elf *ei)
{
size_t i, n;
if (elf_getphdrnum(ei, &n)) {
fprintf(stderr, "elf_getphdrnum() failed: %s\n", elf_errmsg(-1));
}
for (i = 0; i < n; i++) {
GElf_Phdr phdr, phdrOut;
if (gelf_getphdr(ei, i, &phdr) != &phdr) {
fprintf(stderr, "gelf_getphdr() failed for #%d: %s\n", i, elf_errmsg(-1));
break;
}
if (gelf_getphdr(eo, i, &phdrOut) != &phdrOut) {
fprintf(stderr, "gelf_getphdr() failed for #%d: %s\n", i, elf_errmsg(-1));
break;
}
/* Start of segment */
if (phdr.p_type == PT_PHDR) {
/* Skip PHDR entries and fix them up later */
}
else if (phdr.p_offset == 0) {
/* The text segment usually loads the whole ELF header */
phdrOut.p_offset = 0;
} else {
/* Try to guess the start of the segment */
Elf_Scn *scn, *scnOut;
GElf_Shdr shdr, shdrOut;
scn = elfu_firstSectionInSegment(ei, &phdr);
if (!scn) {
fprintf(stderr, "elfu_firstSectionInSegment() failed for segment #%d\n", i);
continue;
}
if (gelf_getshdr(scn, &shdr) != &shdr) {
fprintf(stderr, "gelf_getshdr() failed: %s\n", elf_errmsg(-1));
}
if (phdr.p_offset < shdr.sh_offset) {
fprintf(stderr, "elfu_copySegments2: Segment #%d starts before first contained section.\n", i);
}
scnOut = elf_getscn(eo, elf_ndxscn(scn));
if (!scnOut) {
fprintf(stderr, "elf_getscn() failed: %s\n", elf_errmsg(-1));
}
if (gelf_getshdr(scnOut, &shdrOut) != &shdrOut) {
fprintf(stderr, "gelf_getshdr() failed: %s\n", elf_errmsg(-1));
}
phdrOut.p_offset = shdrOut.sh_offset;
}
/* File length of segment */
if (phdr.p_type == PT_PHDR) {
/* Skip PHDR entries and fix them up later */
}
else if (phdr.p_filesz == 0) {
phdrOut.p_filesz = 0;
} else {
/* Try to guess the end of the segment */
Elf_Scn *scn, *scnOut;
GElf_Shdr shdr, shdrOut;
scn = elfu_lastSectionInSegment(ei, &phdr);
if (!scn) {
fprintf(stderr, "elfu_lastSectionInSegment() failed for segment #%d\n", i);
continue;
}
if (gelf_getshdr(scn, &shdr) != &shdr) {
fprintf(stderr, "gelf_getshdr() failed: %s\n", elf_errmsg(-1));
}
if (phdr.p_offset + phdr.p_filesz > shdr.sh_offset + shdr.sh_size) {
fprintf(stderr, "elfu_copySegments2: Segment #%d ends after last contained section.\n", i);
}
scnOut = elf_getscn(eo, elf_ndxscn(scn));
if (!scnOut) {
fprintf(stderr, "elf_getscn() failed: %s\n", elf_errmsg(-1));
}
if (gelf_getshdr(scnOut, &shdrOut) != &shdrOut) {
fprintf(stderr, "gelf_getshdr() failed: %s\n", elf_errmsg(-1));
}
phdrOut.p_filesz = shdrOut.sh_offset - phdrOut.p_offset + shdrOut.sh_size;
}
if (phdr.p_type == PT_PHDR) {
/* Skip PHDR entries and fix them up later */
}
else if (phdr.p_memsz == 0) {
phdrOut.p_memsz = 0;
} else {
// TODO: Calculate memory size (depends on .bss, etc.)
phdrOut.p_memsz = phdrOut.p_filesz; // FIXME
}
if (!gelf_update_phdr (eo, i, &phdrOut)) {
fprintf(stderr, "gelf_update_ehdr() failed: %s\n", elf_errmsg(-1));
}
}
/* Tell libelf that phdrs have changed */
elf_flagphdr(eo, ELF_C_SET, ELF_F_DIRTY);
}
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