unsigned int
elf_flagehdr(Elf *e, Elf_Cmd c, unsigned int flags)
{
int ec;
void *ehdr;
if (e == NULL)
return (0);
if ((c != ELF_C_SET && c != ELF_C_CLR) ||
(e->e_kind != ELF_K_ELF) || (flags & ~ELF_F_DIRTY) != 0 ||
((ec = e->e_class) != ELFCLASS32 && ec != ELFCLASS64)) {
LIBELF_SET_ERROR(ARGUMENT, 0);
return (0);
}
if (ec == ELFCLASS32)
ehdr = e->e_u.e_elf.e_ehdr.e_ehdr32;
else
ehdr = e->e_u.e_elf.e_ehdr.e_ehdr64;
if (ehdr == NULL) {
LIBELF_SET_ERROR(SEQUENCE, 0);
return (0);
}
return (elf_flagelf(e, c, flags));
}
int elf_utils_copy(Elf *dest, Elf *source)
{
GElf_Ehdr ehdr;
Elf_Scn *dst_scn, *src_scn;
GElf_Shdr shdr;
Elf_Data *dst_data, *src_data;
size_t segment_count, segndx;
GElf_Phdr phdr;
ELF_ASSERT(elf_flagelf(dest, ELF_C_SET, ELF_F_LAYOUT));
ELF_ASSERT(gelf_getehdr(source, &ehdr));
ELF_ASSERT(gelf_newehdr(dest, gelf_getclass(source)));
ELF_ASSERT(gelf_update_ehdr(dest, &ehdr));
src_scn = NULL;
while ((src_scn = elf_nextscn(source, src_scn)) != NULL) {
ELF_ASSERT(gelf_getshdr(src_scn, &shdr));
ELF_ASSERT(dst_scn = elf_newscn(dest));
ELF_ASSERT(gelf_update_shdr(dst_scn, &shdr));
src_data = NULL;
while ((src_data = elf_getdata(src_scn, src_data)) != NULL) {
ELF_ASSERT(dst_data = elf_newdata(dst_scn));
memcpy(dst_data, src_data, sizeof(Elf_Data));
}
}
ELF_ASSERT(elf_getphdrnum(source, &segment_count) == 0);
ELF_ASSERT(gelf_newphdr(dest, segment_count));
for (segndx = 0; segndx < segment_count; segndx++) {
ELF_ASSERT(gelf_getphdr(source, segndx, &phdr));
ELF_ASSERT(gelf_update_phdr(dest, segndx, &phdr));
}
return 1;
failure:
return 0;
}
DSO *
fdopen_dso (int fd, const char *name)
{
Elf *elf = NULL;
GElf_Ehdr ehdr;
GElf_Addr last_off;
int i, j, k, last, *sections, *invsections;
DSO *dso = NULL;
struct PLArch *plarch;
extern struct PLArch __start_pl_arch[], __stop_pl_arch[];
elf = elf_begin (fd, ELF_C_READ, NULL);
if (elf == NULL)
{
error (0, 0, "cannot open ELF file: %s", elf_errmsg (-1));
goto error_out;
}
if (elf_kind (elf) != ELF_K_ELF)
{
error (0, 0, "\"%s\" is not an ELF file", name);
goto error_out;
}
if (gelf_getehdr (elf, &ehdr) == NULL)
{
error (0, 0, "cannot get the ELF header: %s",
elf_errmsg (-1));
goto error_out;
}
if (ehdr.e_type != ET_DYN && ehdr.e_type != ET_EXEC)
{
error (0, 0, "\"%s\" is not a shared library", name);
goto error_out;
}
if (ehdr.e_shnum == 0)
{
GElf_Phdr phdr;
/* Check for UPX compressed executables. */
if (ehdr.e_type == ET_EXEC
&& ehdr.e_phnum > 0
&& (gelf_getphdr (elf, 0, &phdr), phdr.p_type == PT_LOAD)
&& phdr.p_filesz >= 256
&& phdr.p_filesz <= 4096
&& phdr.p_offset == 0
&& ehdr.e_phoff + ehdr.e_phnum * ehdr.e_phentsize < phdr.p_filesz)
{
char *buf = alloca (phdr.p_filesz);
size_t start = ehdr.e_phoff + ehdr.e_phnum * ehdr.e_phentsize;
if (pread (fd, buf, phdr.p_filesz, 0) == phdr.p_filesz
&& memmem (buf + start, phdr.p_filesz - start,
"UPX!", 4) != NULL)
{
error (0, 0, "\"%s\" is UPX compressed executable", name);
goto error_out;
}
}
error (0, 0, "\"%s\" has no section headers", name);
goto error_out;
}
/* Allocate DSO structure. Leave place for additional 20 new section
headers. */
dso = (DSO *)
malloc (sizeof(DSO) + (ehdr.e_shnum + 20) * sizeof(GElf_Shdr)
+ (ehdr.e_phnum + 1) * sizeof(GElf_Phdr)
+ (ehdr.e_shnum + 20) * sizeof(Elf_Scn *));
if (!dso)
{
error (0, ENOMEM, "Could not open DSO");
goto error_out;
}
elf_flagelf (elf, ELF_C_SET, ELF_F_LAYOUT | ELF_F_PERMISSIVE);
memset (dso, 0, sizeof(DSO));
dso->elf = elf;
dso->ehdr = ehdr;
dso->phdr = (GElf_Phdr *) &dso->shdr[ehdr.e_shnum + 20];
dso->scn = (Elf_Scn **) &dso->phdr[ehdr.e_phnum + 1];
switch (ehdr.e_ident[EI_CLASS])
{
case ELFCLASS32:
dso->mask = 0xffffffff; break;
case ELFCLASS64:
dso->mask = 0xffffffffffffffffULL; break;
}
for (i = 0; i < ehdr.e_phnum; ++i)
gelf_getphdr (elf, i, dso->phdr + i);
dso->fd = fd;
for (i = 0, j = 0; i < ehdr.e_shnum; ++i)
{
dso->scn[i] = elf_getscn (elf, i);
gelfx_getshdr (elf, dso->scn[i], dso->shdr + i);
if ((dso->shdr[i].sh_flags & SHF_ALLOC) && dso->shdr[i].sh_type != SHT_NOBITS)
j = 1;
}
if (j == 0)
{
/* If all ALLOC sections are SHT_NOBITS, then this is a
stripped-to-file debuginfo. Skip it silently. */
goto error_out;
}
sections = (int *) alloca (dso->ehdr.e_shnum * sizeof (int) * 2);
sections[0] = 0;
for (i = 1, j = 1, k = dso->ehdr.e_shnum, last = -1;
i < dso->ehdr.e_shnum; ++i)
if (RELOCATE_SCN (dso->shdr[i].sh_flags))
{
last = i;
sections[j++] = i;
}
else
sections[--k] = i;
assert (j == k);
section_cmp_dso = dso;
qsort (sections + k, dso->ehdr.e_shnum - k, sizeof (*sections), section_cmp);
invsections = sections + dso->ehdr.e_shnum;
invsections[0] = 0;
for (i = 1, j = 0; i < ehdr.e_shnum; ++i)
{
if (i != sections[i])
{
j = 1;
dso->scn[i] = elf_getscn (elf, sections[i]);
gelfx_getshdr (elf, dso->scn[i], dso->shdr + i);
}
invsections[sections[i]] = i;
}
if (j)
{
dso->move = init_section_move (dso);
if (dso->move == NULL)
goto error_out;
memcpy (dso->move->old_to_new, invsections, dso->ehdr.e_shnum * sizeof (int));
memcpy (dso->move->new_to_old, sections, dso->ehdr.e_shnum * sizeof (int));
}
last_off = 0;
for (i = 1; i < ehdr.e_shnum; ++i)
{
if (dso->shdr[i].sh_link >= ehdr.e_shnum)
{
error (0, 0, "%s: bogus sh_link value %d", name,
dso->shdr[i].sh_link);
goto error_out;
}
dso->shdr[i].sh_link = invsections[dso->shdr[i].sh_link];
if (dso->shdr[i].sh_type == SHT_REL
|| dso->shdr[i].sh_type == SHT_RELA
|| (dso->shdr[i].sh_flags & SHF_INFO_LINK))
{
if (dso->shdr[i].sh_info >= ehdr.e_shnum)
{
error (0, 0, "%s: bogus sh_info value %d", name,
dso->shdr[i].sh_info);
goto error_out;
}
dso->shdr[i].sh_info = invsections[dso->shdr[i].sh_info];
}
/* Some linkers mess up sh_offset fields for empty or nobits
sections. */
if (RELOCATE_SCN (dso->shdr[i].sh_flags)
&& (dso->shdr[i].sh_size == 0
|| dso->shdr[i].sh_type == SHT_NOBITS))
{
for (j = i + 1; j < ehdr.e_shnum; ++j)
if (! RELOCATE_SCN (dso->shdr[j].sh_flags))
break;
else if (dso->shdr[j].sh_size != 0
&& dso->shdr[j].sh_type != SHT_NOBITS)
break;
dso->shdr[i].sh_offset = (last_off + dso->shdr[i].sh_addralign - 1)
& ~(dso->shdr[i].sh_addralign - 1);
if (j < ehdr.e_shnum
&& dso->shdr[i].sh_offset > dso->shdr[j].sh_offset)
{
GElf_Addr k;
for (k = dso->shdr[i].sh_addralign - 1; k; )
{
k >>= 1;
dso->shdr[i].sh_offset = (last_off + k) & ~k;
if (dso->shdr[i].sh_offset <= dso->shdr[j].sh_offset)
break;
}
}
last_off = dso->shdr[i].sh_offset;
}
else
static int
build_file(Elf *src_elf, GElf_Ehdr *src_ehdr, Cmd_Info *cmd_info)
{
Elf_Scn *src_scn;
Elf_Scn *dst_scn;
int new_sh_name = 0; /* to hold the offset for the new */
/* section's name */
Elf *dst_elf = 0;
Elf_Data *elf_data;
Elf_Data *data;
int64_t scn_no, x;
size_t no_of_symbols = 0;
section_info_table *info;
unsigned int c = 0;
int fdtmp;
GElf_Shdr src_shdr;
GElf_Shdr dst_shdr;
GElf_Ehdr dst_ehdr;
GElf_Off new_offset = 0, r;
size_t shnum, shstrndx;
if (elf_getshnum(src_elf, &shnum) == NULL) {
error_message(LIBELF_ERROR,
LIBelf_ERROR, elf_errmsg(-1), prog);
return (FAILURE);
}
if (elf_getshstrndx(src_elf, &shstrndx) == NULL) {
error_message(LIBELF_ERROR,
LIBelf_ERROR, elf_errmsg(-1), prog);
return (FAILURE);
}
if ((fdtmp = open(elftmpfile, O_RDWR |
O_TRUNC | O_CREAT, (mode_t)0666)) == -1) {
error_message(OPEN_TEMP_ERROR,
SYSTEM_ERROR, strerror(errno),
prog, elftmpfile);
return (FAILURE);
}
if ((dst_elf = elf_begin(fdtmp, ELF_C_WRITE, (Elf *) 0)) == NULL) {
error_message(READ_ERROR,
LIBelf_ERROR, elf_errmsg(-1),
prog, elftmpfile);
(void) close(fdtmp);
return (FAILURE);
}
if (gelf_newehdr(dst_elf, gelf_getclass(src_elf)) == NULL) {
error_message(LIBELF_ERROR,
LIBelf_ERROR, elf_errmsg(-1), prog);
return (FAILURE);
}
/* initialize dst_ehdr */
(void) gelf_getehdr(dst_elf, &dst_ehdr);
dst_ehdr = *src_ehdr;
/*
* flush the changes to the ehdr so the
* ident array is filled in.
*/
(void) gelf_update_ehdr(dst_elf, &dst_ehdr);
if (src_ehdr->e_phnum != 0) {
(void) elf_flagelf(dst_elf, ELF_C_SET, ELF_F_LAYOUT);
if (gelf_newphdr(dst_elf, src_ehdr->e_phnum) == NULL) {
error_message(LIBELF_ERROR,
LIBelf_ERROR, elf_errmsg(-1), prog);
return (FAILURE);
}
for (x = 0; x < src_ehdr->e_phnum; ++x) {
GElf_Phdr dst;
GElf_Phdr src;
/* LINTED */
(void) gelf_getphdr(src_elf, (int)x, &src);
/* LINTED */
(void) gelf_getphdr(dst_elf, (int)x, &dst);
(void) memcpy(&dst, &src, sizeof (GElf_Phdr));
/* LINTED */
(void) gelf_update_phdr(dst_elf, (int)x, &dst);
}
x = location(dst_ehdr.e_phoff, 0, src_elf);
if (x == AFTER)
new_offset = (GElf_Off)src_ehdr->e_ehsize;
}
scn_no = 1;
while ((src_scn = sec_table[scn_no].scn) != (Elf_Scn *) -1) {
info = &sec_table[scn_no];
/* If section should be copied to new file NOW */
if ((info->secno != (GElf_Word)DELETED) &&
info->secno <= scn_no) {
if ((dst_scn = elf_newscn(dst_elf)) == NULL) {
error_message(LIBELF_ERROR,
LIBelf_ERROR, elf_errmsg(-1), prog);
return (FAILURE);
}
(void) gelf_getshdr(dst_scn, &dst_shdr);
(void) gelf_getshdr(info->scn, &src_shdr);
(void) memcpy(&dst_shdr, &src_shdr, sizeof (GElf_Shdr));
/*
* Update link and info fields
* The sh_link field may have special values so
* check them first.
*/
if ((src_shdr.sh_link >= shnum) ||
(src_shdr.sh_link == 0))
dst_shdr.sh_link = src_shdr.sh_link;
else if ((int)sec_table[src_shdr.sh_link].secno < 0)
dst_shdr.sh_link = 0;
else
dst_shdr.sh_link =
sec_table[src_shdr.sh_link].secno;
if ((src_shdr.sh_type == SHT_REL) ||
(src_shdr.sh_type == SHT_RELA)) {
if ((src_shdr.sh_info >= shnum) ||
((int)sec_table[src_shdr.
sh_info].secno < 0))
dst_shdr.sh_info = 0;
else
dst_shdr.sh_info =
sec_table[src_shdr.sh_info].secno;
}
data = sec_table[scn_no].data;
if ((elf_data = elf_newdata(dst_scn)) == NULL) {
error_message(LIBELF_ERROR,
LIBelf_ERROR, elf_errmsg(-1), prog);
return (FAILURE);
}
*elf_data = *data;
/* SHT_{DYNSYM, SYMTAB} might need some change */
if (((src_shdr.sh_type == SHT_SYMTAB) ||
(src_shdr.sh_type == SHT_DYNSYM)) &&
src_shdr.sh_entsize != 0 &&
(cmd_info->no_of_delete != 0 ||
cmd_info->no_of_nulled != 0)) {
char *new_sym;
no_of_symbols = src_shdr.sh_size /
src_shdr.sh_entsize;
new_sym = malloc(no_of_symbols *
src_shdr.sh_entsize);
if (new_sym == NULL) {
error_message(MALLOC_ERROR,
PLAIN_ERROR, (char *)0, prog);
mcs_exit(FAILURE);
}
/* CSTYLED */
elf_data->d_buf = (void *) new_sym;
for (c = 0; c < no_of_symbols; c++) {
GElf_Sym csym;
(void) gelf_getsym(data, c, &csym);
if ((csym.st_shndx < SHN_LORESERVE) &&
(csym.st_shndx != SHN_UNDEF)) {
section_info_table *i;
i = &sec_table[csym.st_shndx];
if (((int)i->secno !=
DELETED) &&
((int)i->secno != NULLED))
csym.st_shndx =
i->secno;
else {
if (src_shdr.sh_type ==
SHT_SYMTAB)
/*
* The section which
* this * symbol relates
* to is removed.
* There is no way to
* specify this fact,
* just change the shndx
* to 1.
*/
csym.st_shndx = 1;
else {
/*
* If this is in a
* .dynsym, NULL it out.
*/
csym.st_shndx = 0;
csym.st_name = 0;
csym.st_value = 0;
csym.st_size = 0;
csym.st_info = 0;
csym.st_other = 0;
csym.st_shndx = 0;
}
}
}
(void) gelf_update_sym(elf_data, c,
&csym);
}
}
/* update SHT_SYMTAB_SHNDX */
if ((src_shdr.sh_type == SHT_SYMTAB_SHNDX) &&
(src_shdr.sh_entsize != 0) &&
((cmd_info->no_of_delete != 0) ||
(cmd_info->no_of_nulled != 0))) {
GElf_Word *oldshndx;
GElf_Word *newshndx;
uint_t entcnt;
entcnt = src_shdr.sh_size /
src_shdr.sh_entsize;
oldshndx = data->d_buf;
newshndx = malloc(entcnt *
src_shdr.sh_entsize);
if (newshndx == NULL) {
error_message(MALLOC_ERROR,
PLAIN_ERROR, (char *)0, prog);
mcs_exit(FAILURE);
}
elf_data->d_buf = (void *)newshndx;
for (c = 0; c < entcnt; c++) {
if (oldshndx[c] != SHN_UNDEF) {
section_info_table *i;
i = &sec_table[oldshndx[c]];
if (((int)i->secno !=
DELETED) &&
((int)i->secno != NULLED))
newshndx[c] = i->secno;
else
newshndx[c] =
oldshndx[c];
} else
newshndx[c] =
oldshndx[c];
}
}
/*
* If the section is to be updated,
* do so.
*/
if (ISCANDIDATE(info->flags)) {
if ((GET_LOC(info->flags) == PRIOR) &&
(((int)info->secno == NULLED) ||
((int)info->secno == EXPANDED) ||
((int)info->secno == SHRUNK))) {
/*
* The section is updated,
* but the position is not too
* good. Need to NULL this out.
*/
dst_shdr.sh_name = 0;
dst_shdr.sh_type = SHT_PROGBITS;
if ((int)info->secno != NULLED) {
(cmd_info->no_of_moved)++;
SET_MOVING(info->flags);
}
} else {
/*
* The section is positioned AFTER,
* or there are no segments.
* It is safe to update this section.
*/
data = sec_table[scn_no].mdata;
*elf_data = *data;
dst_shdr.sh_size = elf_data->d_size;
}
}
/* add new section name to shstrtab? */
else if (!Sect_exists &&
(new_sec_string != NULL) &&
(scn_no == shstrndx) &&
(dst_shdr.sh_type == SHT_STRTAB) &&
((src_ehdr->e_phnum == 0) ||
((x = scn_location(dst_scn, dst_elf)) != IN) ||
(x != PRIOR))) {
size_t sect_len;
sect_len = strlen(SECT_NAME);
if ((elf_data->d_buf =
malloc((dst_shdr.sh_size +
sect_len + 1))) == NULL) {
error_message(MALLOC_ERROR,
PLAIN_ERROR, (char *)0, prog);
mcs_exit(FAILURE);
}
/* put original data plus new data in section */
(void) memcpy(elf_data->d_buf,
data->d_buf, data->d_size);
(void) memcpy(&((char *)elf_data->d_buf)
[data->d_size],
SECT_NAME,
sect_len + 1);
/* LINTED */
new_sh_name = (int)dst_shdr.sh_size;
dst_shdr.sh_size += sect_len + 1;
elf_data->d_size += sect_len + 1;
}
/*
* Compute offsets.
*/
if (src_ehdr->e_phnum != 0) {
/*
* Compute section offset.
*/
if (off_table[scn_no] == 0) {
if (dst_shdr.sh_addralign != 0) {
r = new_offset %
dst_shdr.sh_addralign;
if (r)
new_offset +=
dst_shdr.sh_addralign - r;
}
dst_shdr.sh_offset = new_offset;
elf_data->d_off = 0;
} else {
if (nobits_table[scn_no] == 0)
new_offset = off_table[scn_no];
}
if (nobits_table[scn_no] == 0)
new_offset += dst_shdr.sh_size;
}
}
(void) gelf_update_shdr(dst_scn, &dst_shdr); /* flush changes */
scn_no++;
}
/*
* This is the real new section.
*/
if (!Sect_exists && new_sec_string != NULL) {
size_t string_size;
string_size = strlen(new_sec_string) + 1;
if ((dst_scn = elf_newscn(dst_elf)) == NULL) {
error_message(LIBELF_ERROR,
LIBelf_ERROR, elf_errmsg(-1), prog);
return (FAILURE);
}
(void) gelf_getshdr(dst_scn, &dst_shdr);
dst_shdr.sh_name = new_sh_name;
dst_shdr.sh_type = SHT_PROGBITS;
dst_shdr.sh_flags = 0;
dst_shdr.sh_addr = 0;
if (src_ehdr->e_phnum != NULL)
dst_shdr.sh_offset = new_offset;
else
dst_shdr.sh_offset = 0;
dst_shdr.sh_size = string_size + 1;
dst_shdr.sh_link = 0;
dst_shdr.sh_info = 0;
dst_shdr.sh_addralign = 1;
dst_shdr.sh_entsize = 0;
(void) gelf_update_shdr(dst_scn, &dst_shdr); /* flush changes */
if ((elf_data = elf_newdata(dst_scn)) == NULL) {
error_message(LIBELF_ERROR,
LIBelf_ERROR, elf_errmsg(-1), prog);
return (FAILURE);
}
elf_data->d_size = string_size + 1;
if ((elf_data->d_buf = (char *)
calloc(1, string_size + 1)) == NULL) {
error_message(MALLOC_ERROR,
PLAIN_ERROR, (char *)0,
prog);
mcs_exit(FAILURE);
}
(void) memcpy(&((char *)elf_data->d_buf)[1],
new_sec_string, string_size);
elf_data->d_align = 1;
new_offset += string_size + 1;
}
/*
* If there are sections which needed to be moved,
* then do it here.
*/
if (cmd_info->no_of_moved != 0) {
int cnt;
info = &sec_table[0];
for (cnt = 0; cnt < shnum; cnt++, info++) {
if ((GET_MOVING(info->flags)) == 0)
continue;
if ((src_scn = elf_getscn(src_elf, info->osecno)) ==
NULL) {
error_message(LIBELF_ERROR,
LIBelf_ERROR, elf_errmsg(-1), prog);
return (FAILURE);
}
if (gelf_getshdr(src_scn, &src_shdr) == NULL) {
error_message(LIBELF_ERROR,
LIBelf_ERROR, elf_errmsg(-1), prog);
return (FAILURE);
}
if ((dst_scn = elf_newscn(dst_elf)) == NULL) {
error_message(LIBELF_ERROR,
LIBelf_ERROR, elf_errmsg(-1), prog);
return (FAILURE);
}
if (gelf_getshdr(dst_scn, &dst_shdr) == NULL) {
error_message(LIBELF_ERROR,
LIBelf_ERROR, elf_errmsg(-1), prog);
return (FAILURE);
}
dst_shdr = src_shdr;
data = info->mdata;
dst_shdr.sh_offset = new_offset; /* UPDATE fields */
dst_shdr.sh_size = data->d_size;
if ((shnum >= src_shdr.sh_link) ||
(src_shdr.sh_link == 0))
dst_shdr.sh_link = src_shdr.sh_link;
else
dst_shdr.sh_link =
sec_table[src_shdr.sh_link].osecno;
if ((shnum >= src_shdr.sh_info) ||
(src_shdr.sh_info == 0))
dst_shdr.sh_info = src_shdr.sh_info;
else
dst_shdr.sh_info =
sec_table[src_shdr.sh_info].osecno;
(void) gelf_update_shdr(dst_scn, &dst_shdr);
if ((elf_data = elf_newdata(dst_scn)) == NULL) {
error_message(LIBELF_ERROR,
LIBelf_ERROR, elf_errmsg(-1), prog);
return (FAILURE);
}
(void) memcpy(elf_data, data, sizeof (Elf_Data));
new_offset += data->d_size;
}
}
/*
* In the event that the position of the sting table has changed,
* as a result of deleted sections, update the ehdr->e_shstrndx.
*/
if ((shstrndx > 0) && (shnum > 0) &&
(sec_table[shstrndx].secno < shnum)) {
if (sec_table[shstrndx].secno < SHN_LORESERVE) {
dst_ehdr.e_shstrndx =
sec_table[dst_ehdr.e_shstrndx].secno;
} else {
Elf_Scn *_scn;
GElf_Shdr shdr0;
/*
* If shstrndx requires 'Extended ELF Sections'
* then it is stored in shdr[0].sh_link
*/
dst_ehdr.e_shstrndx = SHN_XINDEX;
if ((_scn = elf_getscn(dst_elf, 0)) == NULL) {
error_message(LIBELF_ERROR,
LIBelf_ERROR, elf_errmsg(-1), prog);
return (FAILURE);
}
(void) gelf_getshdr(_scn, &shdr0);
shdr0.sh_link = sec_table[shstrndx].secno;
(void) gelf_update_shdr(_scn, &shdr0);
}
}
if (src_ehdr->e_phnum != 0) {
size_t align = gelf_fsize(dst_elf, ELF_T_ADDR, 1, EV_CURRENT);
/* UPDATE location of program header table */
if (location(dst_ehdr.e_phoff, 0, dst_elf) == AFTER) {
r = new_offset % align;
if (r)
new_offset += align - r;
dst_ehdr.e_phoff = new_offset;
new_offset += dst_ehdr.e_phnum
* dst_ehdr.e_phentsize;
}
/* UPDATE location of section header table */
if ((location(dst_ehdr.e_shoff, 0, src_elf) == AFTER) ||
((location(dst_ehdr.e_shoff, 0, src_elf) == PRIOR) &&
(!Sect_exists && new_sec_string != NULL))) {
r = new_offset % align;
if (r)
new_offset += align - r;
dst_ehdr.e_shoff = new_offset;
}
free(b_e_seg_table);
/*
* The NOTE segment is the one segment whos
* sections might get moved by mcs processing.
* Make sure that the NOTE segments offset points
* to the .note section.
*/
if ((notesegndx != -1) && (notesctndx != -1) &&
(sec_table[notesctndx].secno)) {
Elf_Scn * notescn;
GElf_Shdr nshdr;
notescn = elf_getscn(dst_elf,
sec_table[notesctndx].secno);
(void) gelf_getshdr(notescn, &nshdr);
if (gelf_getclass(dst_elf) == ELFCLASS32) {
Elf32_Phdr * ph = elf32_getphdr(dst_elf) +
notesegndx;
/* LINTED */
ph->p_offset = (Elf32_Off)nshdr.sh_offset;
} else {
Elf64_Phdr * ph = elf64_getphdr(dst_elf) +
notesegndx;
ph->p_offset = (Elf64_Off)nshdr.sh_offset;
}
}
}
/* copy ehdr changes back into real ehdr */
(void) gelf_update_ehdr(dst_elf, &dst_ehdr);
if (elf_update(dst_elf, ELF_C_WRITE) < 0) {
error_message(LIBELF_ERROR,
LIBelf_ERROR, elf_errmsg(-1), prog);
return (FAILURE);
}
(void) elf_end(dst_elf);
(void) close(fdtmp);
return (SUCCESS);
}
static int
ctf_write_elf(ctf_file_t *fp, Elf *src, Elf *dst, int flags)
{
GElf_Ehdr sehdr, dehdr;
Elf_Scn *sscn, *dscn;
Elf_Data *sdata, *ddata;
GElf_Shdr shdr;
int symtab_idx = -1;
off_t new_offset = 0;
off_t ctfnameoff = 0;
int compress = (flags & CTF_ELFWRITE_F_COMPRESS);
int *secxlate = NULL;
int srcidx, dstidx, pad, i;
int curnmoff = 0;
int changing = 0;
int ret;
size_t nshdr, nphdr, strndx;
void *strdatabuf = NULL, *symdatabuf = NULL;
size_t strdatasz = 0, symdatasz = 0;
void *cdata = NULL;
size_t elfsize, asize;
if ((flags & ~(CTF_ELFWRITE_F_COMPRESS)) != 0) {
ret = ctf_set_errno(fp, EINVAL);
goto out;
}
if (gelf_newehdr(dst, gelf_getclass(src)) == 0) {
ret = ctf_set_errno(fp, ECTF_ELF);
goto out;
}
if (gelf_getehdr(src, &sehdr) == NULL) {
ret = ctf_set_errno(fp, ECTF_ELF);
goto out;
}
(void) memcpy(&dehdr, &sehdr, sizeof (GElf_Ehdr));
if (gelf_update_ehdr(dst, &dehdr) == 0) {
ret = ctf_set_errno(fp, ECTF_ELF);
goto out;
}
/*
* Use libelf to get the number of sections and the string section to
* deal with ELF files that may have a large number of sections. We just
* always use this to make our live easier.
*/
if (elf_getphdrnum(src, &nphdr) != 0) {
ret = ctf_set_errno(fp, ECTF_ELF);
goto out;
}
if (elf_getshdrnum(src, &nshdr) != 0) {
ret = ctf_set_errno(fp, ECTF_ELF);
goto out;
}
if (elf_getshdrstrndx(src, &strndx) != 0) {
ret = ctf_set_errno(fp, ECTF_ELF);
goto out;
}
/*
* Neither the existing debug sections nor the SUNW_ctf sections (new or
* existing) are SHF_ALLOC'd, so they won't be in areas referenced by
* program headers. As such, we can just blindly copy the program
* headers from the existing file to the new file.
*/
if (nphdr != 0) {
(void) elf_flagelf(dst, ELF_C_SET, ELF_F_LAYOUT);
if (gelf_newphdr(dst, nphdr) == 0) {
ret = ctf_set_errno(fp, ECTF_ELF);
goto out;
}
for (i = 0; i < nphdr; i++) {
GElf_Phdr phdr;
if (gelf_getphdr(src, i, &phdr) == NULL) {
ret = ctf_set_errno(fp, ECTF_ELF);
goto out;
}
if (gelf_update_phdr(dst, i, &phdr) == 0) {
ret = ctf_set_errno(fp, ECTF_ELF);
goto out;
}
}
}
secxlate = ctf_alloc(sizeof (int) * nshdr);
for (srcidx = dstidx = 0; srcidx < nshdr; srcidx++) {
Elf_Scn *scn = elf_getscn(src, srcidx);
GElf_Shdr shdr;
char *sname;
if (gelf_getshdr(scn, &shdr) == NULL) {
ret = ctf_set_errno(fp, ECTF_ELF);
goto out;
}
sname = elf_strptr(src, strndx, shdr.sh_name);
if (sname == NULL) {
ret = ctf_set_errno(fp, ECTF_ELF);
goto out;
}
if (strcmp(sname, CTF_ELF_SCN_NAME) == 0) {
secxlate[srcidx] = -1;
} else {
secxlate[srcidx] = dstidx++;
curnmoff += strlen(sname) + 1;
}
new_offset = (off_t)dehdr.e_phoff;
}
for (srcidx = 1; srcidx < nshdr; srcidx++) {
char *sname;
sscn = elf_getscn(src, srcidx);
if (gelf_getshdr(sscn, &shdr) == NULL) {
ret = ctf_set_errno(fp, ECTF_ELF);
goto out;
}
if (secxlate[srcidx] == -1) {
changing = 1;
continue;
}
dscn = elf_newscn(dst);
if (dscn == NULL) {
ret = ctf_set_errno(fp, ECTF_ELF);
goto out;
}
/*
* If this file has program headers, we need to explicitly lay
* out sections. If none of the sections prior to this one have
* been removed, then we can just use the existing location. If
* one or more sections have been changed, then we need to
* adjust this one to avoid holes.
*/
if (changing && nphdr != 0) {
pad = new_offset % shdr.sh_addralign;
if (pad != 0)
new_offset += shdr.sh_addralign - pad;
shdr.sh_offset = new_offset;
}
shdr.sh_link = secxlate[shdr.sh_link];
if (shdr.sh_type == SHT_REL || shdr.sh_type == SHT_RELA)
shdr.sh_info = secxlate[shdr.sh_info];
sname = elf_strptr(src, strndx, shdr.sh_name);
if (sname == NULL) {
ret = ctf_set_errno(fp, ECTF_ELF);
goto out;
}
if ((sdata = elf_getdata(sscn, NULL)) == NULL) {
ret = ctf_set_errno(fp, ECTF_ELF);
goto out;
}
if ((ddata = elf_newdata(dscn)) == NULL) {
ret = ctf_set_errno(fp, ECTF_ELF);
goto out;
}
bcopy(sdata, ddata, sizeof (Elf_Data));
if (srcidx == strndx) {
char seclen = strlen(CTF_ELF_SCN_NAME);
strdatasz = ddata->d_size + shdr.sh_size +
seclen + 1;
ddata->d_buf = strdatabuf = ctf_alloc(strdatasz);
if (ddata->d_buf == NULL) {
ret = ctf_set_errno(fp, ECTF_ELF);
goto out;
}
bcopy(sdata->d_buf, ddata->d_buf, shdr.sh_size);
(void) strcpy((caddr_t)ddata->d_buf + shdr.sh_size,
CTF_ELF_SCN_NAME);
ctfnameoff = (off_t)shdr.sh_size;
shdr.sh_size += seclen + 1;
ddata->d_size += seclen + 1;
if (nphdr != 0)
changing = 1;
}
if (shdr.sh_type == SHT_SYMTAB && shdr.sh_entsize != 0) {
int nsym = shdr.sh_size / shdr.sh_entsize;
symtab_idx = secxlate[srcidx];
symdatasz = shdr.sh_size;
ddata->d_buf = symdatabuf = ctf_alloc(symdatasz);
if (ddata->d_buf == NULL) {
ret = ctf_set_errno(fp, ECTF_ELF);
goto out;
}
(void) bcopy(sdata->d_buf, ddata->d_buf, shdr.sh_size);
for (i = 0; i < nsym; i++) {
GElf_Sym sym;
short newscn;
(void) gelf_getsym(ddata, i, &sym);
if (sym.st_shndx >= SHN_LORESERVE)
continue;
if ((newscn = secxlate[sym.st_shndx]) !=
sym.st_shndx) {
sym.st_shndx =
(newscn == -1 ? 1 : newscn);
if (gelf_update_sym(ddata, i, &sym) ==
0) {
ret = ctf_set_errno(fp,
ECTF_ELF);
goto out;
}
}
}
}
if (gelf_update_shdr(dscn, &shdr) == 0) {
ret = ctf_set_errno(fp, ECTF_ELF);
goto out;
}
new_offset = (off_t)shdr.sh_offset;
if (shdr.sh_type != SHT_NOBITS)
new_offset += shdr.sh_size;
}
if (symtab_idx == -1) {
ret = ctf_set_errno(fp, ECTF_ELF);
goto out;
}
/* Add the ctf section */
if ((dscn = elf_newscn(dst)) == NULL) {
ret = ctf_set_errno(fp, ECTF_ELF);
goto out;
}
if (gelf_getshdr(dscn, &shdr) == NULL) {
ret = ctf_set_errno(fp, ECTF_ELF);
goto out;
}
shdr.sh_name = ctfnameoff;
shdr.sh_type = SHT_PROGBITS;
shdr.sh_size = fp->ctf_size;
shdr.sh_link = symtab_idx;
shdr.sh_addralign = 4;
if (changing && nphdr != 0) {
pad = new_offset % shdr.sh_addralign;
if (pad)
new_offset += shdr.sh_addralign - pad;
shdr.sh_offset = new_offset;
new_offset += shdr.sh_size;
}
if ((ddata = elf_newdata(dscn)) == NULL) {
ret = ctf_set_errno(fp, ECTF_ELF);
goto out;
}
if (compress != 0) {
int err;
if (ctf_zopen(&err) == NULL) {
ret = ctf_set_errno(fp, err);
goto out;
}
if ((err = ctf_compress(fp, &cdata, &asize, &elfsize)) != 0) {
ret = ctf_set_errno(fp, err);
goto out;
}
ddata->d_buf = cdata;
ddata->d_size = elfsize;
} else {
ddata->d_buf = (void *)fp->ctf_base;
ddata->d_size = fp->ctf_size;
}
ddata->d_align = shdr.sh_addralign;
if (gelf_update_shdr(dscn, &shdr) == 0) {
ret = ctf_set_errno(fp, ECTF_ELF);
goto out;
}
/* update the section header location */
if (nphdr != 0) {
size_t align = gelf_fsize(dst, ELF_T_ADDR, 1, EV_CURRENT);
size_t r = new_offset % align;
if (r)
new_offset += align - r;
dehdr.e_shoff = new_offset;
}
/* commit to disk */
if (sehdr.e_shstrndx == SHN_XINDEX)
dehdr.e_shstrndx = SHN_XINDEX;
else
dehdr.e_shstrndx = secxlate[sehdr.e_shstrndx];
if (gelf_update_ehdr(dst, &dehdr) == 0) {
ret = ctf_set_errno(fp, ECTF_ELF);
goto out;
}
if (elf_update(dst, ELF_C_WRITE) < 0) {
ret = ctf_set_errno(fp, ECTF_ELF);
goto out;
}
ret = 0;
out:
if (strdatabuf != NULL)
ctf_free(strdatabuf, strdatasz);
if (symdatabuf != NULL)
ctf_free(symdatabuf, symdatasz);
if (cdata != NULL)
ctf_data_free(cdata, fp->ctf_size);
if (secxlate != NULL)
ctf_free(secxlate, sizeof (int) * nshdr);
return (ret);
}
int
main (int argc, char *argv[])
{
if (argc < 3)
error (EXIT_FAILURE, 0, "usage: %s FROMNAME TONAME", argv[0]);
elf_version (EV_CURRENT);
int infd = open (argv[1], O_RDONLY);
if (infd == -1)
error (EXIT_FAILURE, errno, "cannot open input file '%s'", argv[1]);
Elf *inelf = elf_begin (infd, ELF_C_READ, NULL);
if (inelf == NULL)
error (EXIT_FAILURE, 0, "problems opening '%s' as ELF file: %s",
argv[1], elf_errmsg (-1));
int outfd = creat (argv[2], 0666);
if (outfd == -1)
error (EXIT_FAILURE, errno, "cannot open output file '%s'", argv[2]);
Elf *outelf = elf_begin (outfd, ELF_C_WRITE, NULL);
if (outelf == NULL)
error (EXIT_FAILURE, 0, "problems opening '%s' as ELF file: %s",
argv[2], elf_errmsg (-1));
gelf_newehdr (outelf, gelf_getclass (inelf));
GElf_Ehdr ehdr_mem;
GElf_Ehdr *ehdr;
gelf_update_ehdr (outelf, (ehdr = gelf_getehdr (inelf, &ehdr_mem)));
if (ehdr->e_phnum > 0)
{
int cnt;
if (gelf_newphdr (outelf, ehdr->e_phnum) == 0)
error (EXIT_FAILURE, 0, "cannot create program header: %s",
elf_errmsg (-1));
for (cnt = 0; cnt < ehdr->e_phnum; ++cnt)
{
GElf_Phdr phdr_mem;
gelf_update_phdr (outelf, cnt, gelf_getphdr (inelf, cnt, &phdr_mem));
}
}
Elf_Scn *scn = NULL;
while ((scn = elf_nextscn (inelf, scn)) != NULL)
{
Elf_Scn *newscn = elf_newscn (outelf);
GElf_Shdr shdr_mem;
gelf_update_shdr (newscn, gelf_getshdr (scn, &shdr_mem));
*elf_newdata (newscn) = *elf_getdata (scn, NULL);
}
elf_flagelf (outelf, ELF_C_SET, ELF_F_LAYOUT);
if (elf_update (outelf, ELF_C_WRITE) == -1)
error (EXIT_FAILURE, 0, "elf_update failed: %s", elf_errmsg (-1));
close (outfd);
return 0;
}
int main(int argc, const char *argv[]) {
ssize_t bytes_written; // only used to silence compiler warnings
if (argc < 2)
errx(EX_USAGE, "Usage: PatchEntry <binary>");
if (elf_version(EV_CURRENT) == EV_NONE)
errx(EX_SOFTWARE, "Invalid ELF version: %s", elf_errmsg(-1));
int fd = open(argv[1], O_RDWR);
if (fd == -1)
err(EX_NOINPUT, "open() failed");
Elf *e;
e = elf_begin(fd, ELF_C_RDWR, NULL);
if (e == nullptr)
errx(EX_SOFTWARE, "Failed to read from ELF file: %s", elf_errmsg(-1));
if (elf_kind(e) != ELF_K_ELF)
errx(EX_SOFTWARE, "File is not an ELF object");
// Read the ELF header to find the entry point
// FIXME: check the class/architecture, make sure it's the same as ours
GElf_Ehdr elf_hdr;
if (gelf_getehdr(e, &elf_hdr) == NULL)
errx(EX_SOFTWARE, "Failed to read ELF header: %s", elf_errmsg(-1));
auto dt_init = FindDynamicInit(e);
auto dt_init_ofs = 0;
if (dt_init) {
dt_init_ofs = dt_init->info.second.sh_offset +
dt_init->data->d_off +
dt_init->index * sizeof(Elf_Dyn) +
offsetof(Elf_Dyn, d_un);
}
auto pit_sym = FindSymbol(e, kProgramInfoTableName);
auto pit_info = FindSectionDataByAddr(e, pit_sym.st_value);
auto pit_ofs = std::get<0>(pit_info).second.sh_offset + // Section file offset
std::get<1>(pit_info)->d_off + // Elf_Data offset
std::get<2>(pit_info); // Offset relative to Elf_Data
#if 1
if (dt_init)
printf("Old ELF entry:%p DT_INIT:%p@%x PIT:%p@%lx\n",
(void*) elf_hdr.e_entry,
(void*) dt_init->dyn_section.d_un.d_ptr,
dt_init_ofs,
(void*) pit_sym.st_value,
pit_ofs);
else
printf("Old ELF entry:%p DT_INIT:NULL PIT:%p@%lx\n",
(void*) elf_hdr.e_entry,
(void*) pit_sym.st_value,
pit_ofs);
#endif
// Replace the ProgramInfoTable values
auto pit_data = std::get<1>(pit_info);
auto orig_pit = reinterpret_cast<TrapProgramInfoTable*>(
reinterpret_cast<uint8_t*>(pit_data->d_buf) + std::get<2>(pit_info));
TrapProgramInfoTable pit = *orig_pit; // Need to copy it here, since elf_end releases it
if (pit.num_sections != 0)
errx(EX_USAGE, "Binary already contains full ProgramInfoTable structure");
if (dt_init)
pit.orig_dt_init = dt_init->dyn_section.d_un.d_ptr;
else
pit.orig_dt_init = 0;
pit.orig_entry = elf_hdr.e_entry;
// Find executable sections in the binary (.text/.plt/others)
// then copy them over to the PIT
pit.num_sections = TRAP_NUM_SECTIONS;
for (size_t i = 0; i < TRAP_NUM_SECTIONS; i++) {
auto sec_info = FindSectionByName(e, kExecSections[i][0]);
if (sec_info.first != nullptr) {
pit.sections[i].start = sec_info.second.sh_addr;
pit.sections[i].size = sec_info.second.sh_size;
}
auto trap_sec_info = FindSectionByName(e, kExecSections[i][1]);
if (trap_sec_info.first != nullptr) {
pit.sections[i].trap = trap_sec_info.second.sh_addr;
pit.sections[i].trap_size = trap_sec_info.second.sh_size;
}
}
// Set the new entry point addresses
auto entry_trampoline_sym = FindSymbol(e, kEntryTrampolineName);
auto init_trampoline_sym = FindSymbol(e, kInitTrampolineName);
elf_hdr.e_entry = entry_trampoline_sym.st_value;
auto new_dt_init = static_cast<ArchPointer>(init_trampoline_sym.st_value);
// Find export trampolines
auto xptramp_info = FindSectionByName(e, ".xptramp");
DynamicSymbolMap dyn_sym_map;
ExportTrampolineVector xptramp_vec;
size_t xptramp_shndx = 0;
if (xptramp_info.first != nullptr) {
pit.xptramp_start = xptramp_info.second.sh_addr;
pit.xptramp_size = xptramp_info.second.sh_size;
dyn_sym_map = FindDynamicSymbols(e);
xptramp_vec = FindExportTrampolines(e, xptramp_info);
xptramp_shndx = elf_ndxscn(xptramp_info.first);
}
// Update the ELF header, then write it out
// There's some pretty ugly behavior from libelf here:
// if we let it handle the layout, it mis-aligns the data sections
// It also doesn't seem to update the contents correctly,
// so we do that manually
elf_flagelf(e, ELF_C_SET, ELF_F_LAYOUT);
gelf_update_ehdr(e, &elf_hdr);
if (elf_update(e, ELF_C_WRITE) <= 0)
errx(EX_SOFTWARE, "Couldn't update ELF file: %s", elf_errmsg(-1));
elf_end(e);
// FIXME: libelf shenanigans force us to
// write data out to the file manually
// 1) DT_INIT inside .dynamic
if (dt_init) {
printf("writing new DT_INIT: 0x%lu\n", new_dt_init);
lseek(fd, dt_init_ofs, SEEK_SET);
bytes_written = write(fd, &new_dt_init, sizeof(new_dt_init));
}
// 2) The ProgramInfoTable
lseek(fd, pit_ofs, SEEK_SET);
bytes_written = write(fd, &pit, sizeof(pit));
// 3) Exported symbols
WriteExportSymbols(fd, xptramp_info, xptramp_vec, xptramp_shndx, dyn_sym_map);
close(fd);
return 0;
}
void clone_elf(Elf *elf, Elf *newelf,
const char *elf_name,
const char *newelf_name,
bool *sym_filter, int num_symbols,
int shady
#ifdef SUPPORT_ANDROID_PRELINK_TAGS
, int *prelinked,
int *elf_little,
long *prelink_addr
#endif
, bool rebuild_shstrtab,
bool strip_debug,
bool dry_run)
{
GElf_Ehdr ehdr_mem, *ehdr; /* store ELF header of original library */
size_t shstrndx; /* section-strings-section index */
size_t shnum; /* number of sections in the original file */
/* string table for section headers in new file */
struct Ebl_Strtab *shst = NULL;
int dynamic_idx = -1; /* index in shdr_info[] of .dynamic section */
int dynsym_idx = -1; /* index in shdr_info[] of dynamic symbol table
section */
unsigned int cnt; /* general-purpose counter */
/* This flag is true when at least one section is dropped or when the
relative order of sections has changed, so that section indices in
the resulting file will be different from those in the original. */
bool sections_dropped_or_rearranged;
Elf_Scn *scn; /* general-purpose section */
size_t idx; /* general-purporse section index */
shdr_info_t *shdr_info = NULL;
unsigned int shdr_info_len = 0;
GElf_Phdr *phdr_info = NULL;
/* Get the information from the old file. */
ehdr = gelf_getehdr (elf, &ehdr_mem);
FAILIF_LIBELF(NULL == ehdr, gelf_getehdr);
/* Create new program header for the elf file */
FAILIF(gelf_newehdr (newelf, gelf_getclass (elf)) == 0 ||
(ehdr->e_type != ET_REL && gelf_newphdr (newelf,
ehdr->e_phnum) == 0),
"Cannot create new file: %s", elf_errmsg (-1));
#ifdef SUPPORT_ANDROID_PRELINK_TAGS
ASSERT(prelinked);
ASSERT(prelink_addr);
ASSERT(elf_little);
*elf_little = (ehdr->e_ident[EI_DATA] == ELFDATA2LSB);
*prelinked = check_prelinked(elf_name, *elf_little, prelink_addr);
#endif
INFO("\n\nCALCULATING MODIFICATIONS\n\n");
/* Copy out the old program header: notice that if the ELF file does not
have a program header, this loop won't execute.
*/
INFO("Copying ELF program header...\n");
phdr_info = (GElf_Phdr *)CALLOC(ehdr->e_phnum, sizeof(GElf_Phdr));
for (cnt = 0; cnt < ehdr->e_phnum; ++cnt) {
INFO("\tRetrieving entry %d\n", cnt);
FAILIF_LIBELF(NULL == gelf_getphdr(elf, cnt, phdr_info + cnt),
gelf_getphdr);
/* -- we update the header at the end
FAILIF_LIBELF(gelf_update_phdr (newelf, cnt, phdr_info + cnt) == 0,
gelf_update_phdr);
*/
}
/* Get the section-header strings section. This section contains the
strings used to name the other sections. */
FAILIF_LIBELF(elf_getshstrndx(elf, &shstrndx) < 0, elf_getshstrndx);
/* Get the number of sections. */
FAILIF_LIBELF(elf_getshnum (elf, &shnum) < 0, elf_getshnum);
INFO("Original ELF file has %zd sections.\n", shnum);
/* Allocate the section-header-info buffer. We allocate one more entry
for the section-strings section because we regenerate that one and
place it at the very end of the file. Note that just because we create
an extra entry in the shdr_info array, it does not mean that we create
one more section the header. We just mark the old section for removal
and create one as the last section.
*/
INFO("Allocating section-header info structure (%zd) bytes...\n",
shnum*sizeof (shdr_info_t));
shdr_info_len = rebuild_shstrtab ? shnum + 1 : shnum;
shdr_info = (shdr_info_t *)CALLOC(shdr_info_len, sizeof (shdr_info_t));
/* Iterate over all the sections and initialize the internal section-info
array...
*/
INFO("Initializing section-header info structure...\n");
/* Gather information about the sections in this file. */
scn = NULL;
cnt = 1;
while ((scn = elf_nextscn (elf, scn)) != NULL) {
ASSERT(elf_ndxscn(scn) == cnt);
shdr_info[cnt].scn = scn;
FAILIF_LIBELF(NULL == gelf_getshdr(scn, &shdr_info[cnt].shdr),
gelf_getshdr);
/* Get the name of the section. */
shdr_info[cnt].name = elf_strptr (elf, shstrndx,
shdr_info[cnt].shdr.sh_name);
INFO("\tname: %s\n", shdr_info[cnt].name);
FAILIF(shdr_info[cnt].name == NULL,
"Malformed file: section %d name is null\n",
cnt);
/* Mark them as present but not yet investigated. By "investigating"
sections, we mean that we check to see if by stripping other
sections, the sections under investigation will be compromised. For
example, if we are removing a section of code, then we want to make
sure that the symbol table does not contain symbols that refer to
this code, so we investigate the symbol table. If we do find such
symbols, we will not strip the code section.
*/
shdr_info[cnt].idx = 1;
/* Remember the shdr.sh_link value. We need to remember this value
for those sections that refer to other sections. For example,
we need to remember it for relocation-entry sections, because if
we modify the symbol table that a relocation-entry section is
relative to, then we need to patch the relocation section. By the
time we get to deciding whether we need to patch the relocation
section, we will have overwritten its header's sh_link field with
a new value.
*/
shdr_info[cnt].old_shdr = shdr_info[cnt].shdr;
INFO("\t\toriginal sh_link: %08d\n", shdr_info[cnt].old_shdr.sh_link);
INFO("\t\toriginal sh_addr: %lld\n", shdr_info[cnt].old_shdr.sh_addr);
INFO("\t\toriginal sh_offset: %lld\n",
shdr_info[cnt].old_shdr.sh_offset);
INFO("\t\toriginal sh_size: %lld\n", shdr_info[cnt].old_shdr.sh_size);
if (shdr_info[cnt].shdr.sh_type == SHT_DYNAMIC) {
INFO("\t\tthis is the SHT_DYNAMIC section [%s] at index %d\n",
shdr_info[cnt].name,
cnt);
dynamic_idx = cnt;
}
else if (shdr_info[cnt].shdr.sh_type == SHT_DYNSYM) {
INFO("\t\tthis is the SHT_DYNSYM section [%s] at index %d\n",
shdr_info[cnt].name,
cnt);
dynsym_idx = cnt;
}
FAILIF(shdr_info[cnt].shdr.sh_type == SHT_SYMTAB_SHNDX,
"Cannot handle sh_type SHT_SYMTAB_SHNDX!\n");
FAILIF(shdr_info[cnt].shdr.sh_type == SHT_GROUP,
"Cannot handle sh_type SHT_GROUP!\n");
FAILIF(shdr_info[cnt].shdr.sh_type == SHT_GNU_versym,
"Cannot handle sh_type SHT_GNU_versym!\n");
/* Increment the counter. */
++cnt;
} /* while */
/* Get the EBL handling. */
Ebl *ebl = ebl_openbackend (elf);
FAILIF_LIBELF(NULL == ebl, ebl_openbackend);
FAILIF_LIBELF(0 != arm_init(elf, ehdr->e_machine, ebl, sizeof(Ebl)),
arm_init);
if (strip_debug) {
/* This will actually strip more than just sections. It will strip
anything not essential to running the image.
*/
INFO("Finding debug sections to strip.\n");
/* Now determine which sections can go away. The general rule is that
all sections which are not used at runtime are stripped out. But
there are a few exceptions:
- special sections named ".comment" and ".note" are kept
- OS or architecture specific sections are kept since we might not
know how to handle them
- if a section is referred to from a section which is not removed
in the sh_link or sh_info element it cannot be removed either
*/
for (cnt = 1; cnt < shnum; ++cnt) {
/* Check whether the section can be removed. */
if (SECTION_STRIP_P (ebl, elf, ehdr, &shdr_info[cnt].shdr,
shdr_info[cnt].name,
1, /* remove .comment sections */
1 /* remove all debug sections */) ||
/* The macro above is broken--check for .comment explicitly */
!strcmp(".comment", shdr_info[cnt].name)
#ifdef ARM_SPECIFIC_HACKS
||
/* We ignore this section, that's why we can remove it. */
!strcmp(".stack", shdr_info[cnt].name)
#endif
)
{
/* For now assume this section will be removed. */
INFO("Section [%s] will be stripped from image.\n",
shdr_info[cnt].name);
shdr_info[cnt].idx = 0;
}
#ifdef STRIP_STATIC_SYMBOLS
else if (shdr_info[cnt].shdr.sh_type == SHT_SYMTAB) {
/* Mark the static symbol table for removal */
INFO("Section [%s] (static symbol table) will be stripped from image.\n",
shdr_info[cnt].name);
shdr_info[cnt].idx = 0;
if (shdr_info[shdr_info[cnt].shdr.sh_link].shdr.sh_type ==
SHT_STRTAB)
{
/* Mark the symbol table's string table for removal. */
INFO("Section [%s] (static symbol-string table) will be stripped from image.\n",
shdr_info[shdr_info[cnt].shdr.sh_link].name);
shdr_info[shdr_info[cnt].shdr.sh_link].idx = 0;
}
else {
ERROR("Expecting the sh_link field of a symbol table to point to"
" associated symbol-strings table! This is not mandated by"
" the standard, but is a common practice and the only way "
" to know for sure which strings table corresponds to which"
" symbol table!\n");
}
}
#endif
}
/* Mark the SHT_NULL section as handled. */
shdr_info[0].idx = 2;
/* Handle exceptions: section groups and cross-references. We might have
to repeat this a few times since the resetting of the flag might
propagate.
*/
int exceptions_pass = 0;
bool changes;
do {
changes = false;
INFO("\nHandling exceptions, pass %d\n\n", exceptions_pass++);
for (cnt = 1; cnt < shnum; ++cnt) {
if (shdr_info[cnt].idx == 0) {
/* If a relocation section is marked as being removed but the
section it is relocating is not, then do not remove the
relocation section.
*/
if ((shdr_info[cnt].shdr.sh_type == SHT_REL
|| shdr_info[cnt].shdr.sh_type == SHT_RELA)
&& shdr_info[shdr_info[cnt].shdr.sh_info].idx != 0) {
PRINT("\tSection [%s] will not be removed because the "
"section it is relocating (%s) stays.\n",
shdr_info[cnt].name,
shdr_info[shdr_info[cnt].shdr.sh_info].name);
}
}
if (shdr_info[cnt].idx == 1) {
INFO("Processing section [%s]...\n", shdr_info[cnt].name);
/* The content of symbol tables we don't remove must not
reference any section which we do remove. Otherwise
we cannot remove the referred section.
*/
if (shdr_info[cnt].shdr.sh_type == SHT_DYNSYM ||
shdr_info[cnt].shdr.sh_type == SHT_SYMTAB)
{
Elf_Data *symdata;
size_t elsize;
INFO("\tSection [%s] is a symbol table that's not being"
" removed.\n\tChecking to make sure that no symbols"
" refer to sections that are being removed.\n",
shdr_info[cnt].name);
/* Make sure the data is loaded. */
symdata = elf_getdata (shdr_info[cnt].scn, NULL);
FAILIF_LIBELF(NULL == symdata, elf_getdata);
/* Go through all symbols and make sure the section they
reference is not removed. */
elsize = gelf_fsize (elf, ELF_T_SYM, 1, ehdr->e_version);
/* Check the length of the dynamic-symbol filter. */
FAILIF(sym_filter != NULL &&
(size_t)num_symbols != symdata->d_size / elsize,
"Length of dynsym filter (%d) must equal the number"
" of dynamic symbols (%zd)!\n",
num_symbols,
symdata->d_size / elsize);
size_t inner;
for (inner = 0;
inner < symdata->d_size / elsize;
++inner)
{
GElf_Sym sym_mem;
GElf_Sym *sym;
size_t scnidx;
sym = gelf_getsymshndx (symdata, NULL,
inner, &sym_mem, NULL);
FAILIF_LIBELF(sym == NULL, gelf_getsymshndx);
scnidx = sym->st_shndx;
FAILIF(scnidx == SHN_XINDEX,
"Can't handle SHN_XINDEX!\n");
if (scnidx == SHN_UNDEF ||
scnidx >= shnum ||
(scnidx >= SHN_LORESERVE &&
scnidx <= SHN_HIRESERVE) ||
GELF_ST_TYPE (sym->st_info) == STT_SECTION)
{
continue;
}
/* If the symbol is going to be thrown and it is a
global or weak symbol that is defined (not imported),
then continue. Since the symbol is going away, we
do not care whether it refers to a section that is
also going away.
*/
if (sym_filter && !sym_filter[inner])
{
bool global_or_weak =
ELF32_ST_BIND(sym->st_info) == STB_GLOBAL ||
ELF32_ST_BIND(sym->st_info) == STB_WEAK;
if (!global_or_weak && sym->st_shndx != SHN_UNDEF)
continue;
}
/* -- far too much output
INFO("\t\t\tSymbol [%s] (%d)\n",
elf_strptr(elf,
shdr_info[cnt].shdr.sh_link,
sym->st_name),
shdr_info[cnt].shdr.sh_info);
*/
if (shdr_info[scnidx].idx == 0)
{
PRINT("\t\t\tSymbol [%s] refers to section [%s], "
"which is being removed. Will keep that "
"section.\n",
elf_strptr(elf,
shdr_info[cnt].shdr.sh_link,
sym->st_name),
shdr_info[scnidx].name);
/* Mark this section as used. */
shdr_info[scnidx].idx = 1;
changes |= scnidx < cnt;
}
} /* for each symbol */
} /* section type is SHT_DYNSYM or SHT_SYMTAB */
/* Cross referencing happens:
- for the cases the ELF specification says. That are
+ SHT_DYNAMIC in sh_link to string table
+ SHT_HASH in sh_link to symbol table
+ SHT_REL and SHT_RELA in sh_link to symbol table
+ SHT_SYMTAB and SHT_DYNSYM in sh_link to string table
+ SHT_GROUP in sh_link to symbol table
+ SHT_SYMTAB_SHNDX in sh_link to symbol table
Other (OS or architecture-specific) sections might as
well use this field so we process it unconditionally.
- references inside section groups
- specially marked references in sh_info if the SHF_INFO_LINK
flag is set
*/
if (shdr_info[shdr_info[cnt].shdr.sh_link].idx == 0) {
shdr_info[shdr_info[cnt].shdr.sh_link].idx = 1;
changes |= shdr_info[cnt].shdr.sh_link < cnt;
}
/* Handle references through sh_info. */
if (SH_INFO_LINK_P (&shdr_info[cnt].shdr) &&
shdr_info[shdr_info[cnt].shdr.sh_info].idx == 0) {
PRINT("\tSection [%s] links to section [%s], which was "
"marked for removal--it will not be removed.\n",
shdr_info[cnt].name,
shdr_info[shdr_info[cnt].shdr.sh_info].name);
shdr_info[shdr_info[cnt].shdr.sh_info].idx = 1;
changes |= shdr_info[cnt].shdr.sh_info < cnt;
}
/* Mark the section as investigated. */
shdr_info[cnt].idx = 2;
} /* if (shdr_info[cnt].idx == 1) */
} /* for (cnt = 1; cnt < shnum; ++cnt) */
} while (changes);
}
else {
INFO("Not stripping sections.\n");
/* Mark the SHT_NULL section as handled. */
shdr_info[0].idx = 2;
}
/* Mark the section header string table as unused, we will create
a new one as the very last section in the new ELF file.
*/
shdr_info[shstrndx].idx = rebuild_shstrtab ? 0 : 2;
/* We need a string table for the section headers. */
FAILIF_LIBELF((shst = ebl_strtabinit (1 /* null-terminated */)) == NULL,
ebl_strtabinit);
/* Assign new section numbers. */
INFO("Creating new sections...\n");
//shdr_info[0].idx = 0;
for (cnt = idx = 1; cnt < shnum; ++cnt) {
if (shdr_info[cnt].idx > 0) {
shdr_info[cnt].idx = idx++;
/* Create a new section. */
FAILIF_LIBELF((shdr_info[cnt].newscn =
elf_newscn(newelf)) == NULL, elf_newscn);
ASSERT(elf_ndxscn (shdr_info[cnt].newscn) == shdr_info[cnt].idx);
/* Add this name to the section header string table. */
shdr_info[cnt].se = ebl_strtabadd (shst, shdr_info[cnt].name, 0);
INFO("\tsection [%s] (old offset %lld, old size %lld) will have index %d "
"(was %zd).\n",
shdr_info[cnt].name,
shdr_info[cnt].old_shdr.sh_offset,
shdr_info[cnt].old_shdr.sh_size,
shdr_info[cnt].idx,
elf_ndxscn(shdr_info[cnt].scn));
} else {
INFO("\tIgnoring section [%s] (offset %lld, size %lld, index %zd), "
"it will be discarded.\n",
shdr_info[cnt].name,
shdr_info[cnt].shdr.sh_offset,
shdr_info[cnt].shdr.sh_size,
elf_ndxscn(shdr_info[cnt].scn));
}
} /* for */
sections_dropped_or_rearranged = idx != cnt;
Elf_Data *shstrtab_data = NULL;
#if 0
/* Fail if sections are being dropped or rearranged (except for moving shstrtab) or the
symbol filter is not empty, AND the file is an executable.
*/
FAILIF(((idx != cnt && !(cnt - idx == 1 && rebuild_shstrtab)) || sym_filter != NULL) &&
ehdr->e_type != ET_DYN,
"You may not rearrange sections or strip symbols on an executable file!\n");
#endif
INFO("\n\nADJUSTING ELF FILE\n\n");
adjust_elf(elf, elf_name,
newelf, newelf_name,
ebl,
ehdr, /* store ELF header of original library */
sym_filter, num_symbols,
shdr_info, shdr_info_len,
phdr_info,
idx, /* highest_scn_num */
shnum,
shstrndx,
shst,
sections_dropped_or_rearranged,
dynamic_idx, /* index in shdr_info[] of .dynamic section */
dynsym_idx, /* index in shdr_info[] of dynamic symbol table */
shady,
&shstrtab_data,
ehdr->e_type == ET_DYN, /* adjust section ofsets only when the file is a shared library */
rebuild_shstrtab);
/* We have everything from the old file. */
FAILIF_LIBELF(elf_cntl(elf, ELF_C_FDDONE) != 0, elf_cntl);
/* The ELF library better follows our layout when this is not a
relocatable object file. */
elf_flagelf (newelf,
ELF_C_SET,
(ehdr->e_type != ET_REL ? ELF_F_LAYOUT : 0));
/* Finally write the file. */
FAILIF_LIBELF(!dry_run && elf_update(newelf, ELF_C_WRITE) == -1, elf_update);
if (shdr_info != NULL) {
/* For some sections we might have created an table to map symbol
table indices. */
for (cnt = 1; cnt < shdr_info_len; ++cnt) {
FREEIF(shdr_info[cnt].newsymidx);
FREEIF(shdr_info[cnt].symse);
if(shdr_info[cnt].dynsymst != NULL)
ebl_strtabfree (shdr_info[cnt].dynsymst);
}
/* Free the memory. */
FREE (shdr_info);
}
FREEIF(phdr_info);
ebl_closebackend(ebl);
/* Free other resources. */
if (shst != NULL) ebl_strtabfree (shst);
if (shstrtab_data != NULL)
FREEIF(shstrtab_data->d_buf);
}
int
main(int argc, char **argv)
{
GElf_Ehdr ehdr;
Elf *elf;
Elf_Kind kind;
int type = ELFOSABI_NONE;
int retval = 0;
int ch, change = 0, verbose = 0, force = 0, listed = 0;
if (elf_version(EV_CURRENT) == EV_NONE)
errx(EXIT_FAILURE, "elf_version error");
while ((ch = getopt_long(argc, argv, "Vf:hlt:v", brandelf_longopts,
NULL)) != -1)
switch (ch) {
case 'f':
if (change)
errx(EXIT_FAILURE, "ERROR: the -f option is "
"incompatible with the -t option.");
force = 1;
type = atoi(optarg);
if (errno == ERANGE || type < 0 || type > 255) {
warnx("ERROR: invalid argument to option "
"-f: %s", optarg);
usage();
}
break;
case 'h':
usage();
break;
case 'l':
printelftypes();
listed = 1;
break;
case 'v':
verbose = 1;
break;
case 't':
if (force)
errx(EXIT_FAILURE, "the -t option is "
"incompatible with the -f option.");
if ((type = elftype(optarg)) == -1) {
warnx("ERROR: invalid ELF type '%s'", optarg);
usage();
}
change = 1;
break;
case 'V':
printversion();
break;
default:
usage();
}
argc -= optind;
argv += optind;
if (!argc) {
if (listed)
exit(0);
else {
warnx("no file(s) specified");
usage();
}
}
while (argc) {
int fd;
elf = NULL;
if ((fd = open(argv[0], (change || force) ? O_RDWR :
O_RDONLY, 0)) < 0) {
warn("error opening file %s", argv[0]);
retval = 1;
goto fail;
}
if ((elf = elf_begin(fd, (change || force) ? ELF_C_RDWR :
ELF_C_READ, NULL)) == NULL) {
warnx("elf_begin failed: %s", elf_errmsg(-1));
retval = 1;
goto fail;
}
if ((kind = elf_kind(elf)) != ELF_K_ELF) {
if (kind == ELF_K_AR)
warnx("file '%s' is an archive.", argv[0]);
else
warnx("file '%s' is not an ELF file.",
argv[0]);
retval = 1;
goto fail;
}
if (gelf_getehdr(elf, &ehdr) == NULL) {
warnx("gelf_getehdr: %s", elf_errmsg(-1));
retval = 1;
goto fail;
}
if (!change && !force) {
fprintf(stdout,
"File '%s' is of brand '%s' (%u).\n",
argv[0], iselftype(ehdr.e_ident[EI_OSABI]),
ehdr.e_ident[EI_OSABI]);
if (!iselftype(type)) {
warnx("ELF ABI Brand '%u' is unknown",
type);
printelftypes();
}
} else {
/*
* Keep the existing layout of the ELF object.
*/
if (elf_flagelf(elf, ELF_C_SET, ELF_F_LAYOUT) == 0) {
warnx("elf_flagelf failed: %s",
elf_errmsg(-1));
retval = 1;
goto fail;
}
/*
* Update the ABI type.
*/
ehdr.e_ident[EI_OSABI] = type;
if (gelf_update_ehdr(elf, &ehdr) == 0) {
warnx("gelf_update_ehdr error: %s",
elf_errmsg(-1));
retval = 1;
goto fail;
}
/*
* Write back changes.
*/
if (elf_update(elf, ELF_C_WRITE) == -1) {
warnx("elf_update error: %s", elf_errmsg(-1));
retval = 1;
goto fail;
}
}
fail:
if (elf)
elf_end(elf);
if (fd >= 0 && close(fd) == -1) {
warnx("%s: close error", argv[0]);
retval = 1;
}
argc--;
argv++;
}
return (retval);
}
static int replaceAMDILSection(Elf* e, int nStream, MWCALtargetEnum target)
{
Elf_Scn* scn = NULL;
size_t shstrndx = 0;
static const int verbose = 0;
static const int verboseDebug = 0;
/* Get section index of section containing the string table of section names */
if (elf_getshdrstrndx(e, &shstrndx) != 0)
{
mw_printf("elf_getshdrstrndx failed: %s\n", elf_errmsg(-1));
return 1;
}
/* Iterate through all the sections */
while ((scn = elf_nextscn(e, scn)))
{
Elf32_Shdr* shdr;
const char* name;
/* Get the header for this section */
shdr = elf32_getshdr(scn);
if (!shdr)
{
mw_printf("elf32_getshdr() failed: %s\n", elf_errmsg(-1));
return 1;
}
/* Look up the name of the section in the string table */
name = elf_strptr(e, shstrndx, shdr->sh_name);
if (!name)
{
mw_printf("elf_strptr() failed: %s\n", elf_errmsg(-1));
return 1;
}
/*
if (strstr(name, ".rodata") != NULL)
{
Elf_Data* data = elf_getdata(scn, NULL);
FILE* f = fopen("rodata_section.bin", "wb");
if (f)
{
fwrite(data->d_buf, 1, data->d_size, f);
fclose(f);
}
else
{
perror("Failed to open file");
}
size_t roSize;
char* r770RO = mwReadFileWithSize("rodata_section_RV770.bin", &roSize);
assert(r770RO);
data->d_buf = r770RO;
data->d_size = roSize;
if (!elf_flagdata(data, ELF_C_SET, ELF_F_DIRTY))
{
mw_printf("elf_flagdata() failed: %s\n", elf_errmsg(-1));
return 1;
}
if (!elf_flagscn(scn, ELF_C_SET, ELF_F_DIRTY))
{
mw_printf("elf_flagscn() failed: %s\n", elf_errmsg(-1));
return 1;
}
if (elf_update(e, ELF_C_NULL) < 0)
{
mw_printf("elf_update(NULL) failed: %s\n", elf_errmsg(-1));
return 1;
}
}
*/
if (strstr(name, ".amdil") != NULL)
{
int uavId;
const char* uavComment;
Elf_Data* data;
data = elf_getdata(scn, NULL);
if (!data)
{
mw_printf("Failed to get data for .amdil section: %s\n", elf_errmsg(-1));
return 1;
}
if (verbose)
{
mw_printf("Replacing section data of type %d, off %d align "ZU"\n",
data->d_type,
(int) data->d_off,
data->d_align);
}
/* Before we overwrite it, there is information we would like to extract */
uavComment = strstr((const char*) data->d_buf, ";uavid:");
if (!uavComment || (sscanf(uavComment, ";uavid:%d\n", &uavId) != 1))
{
mw_printf("Error reading uavid from IL comment\n");
uavId = -1;
}
ilSrc = getILSrc(nStream, target, uavId, &ilSrcLen);
if (!ilSrc || (ilSrcLen == 0))
{
mw_printf("Failed to get IL source\n");
return 1;
}
data->d_buf = (void*) ilSrc;
data->d_size = ilSrcLen;
if (!elf_flagdata(data, ELF_C_SET, ELF_F_DIRTY))
{
mw_printf("elf_flagdata() failed: %s\n", elf_errmsg(-1));
return 1;
}
if (!elf_flagscn(scn, ELF_C_SET, ELF_F_DIRTY))
{
mw_printf("elf_flagscn() failed: %s\n", elf_errmsg(-1));
return 1;
}
/* Don't let libelf rearrange the sections when writing.
clBuildProgram() crashes on Windows if you don't do
this with some(?) Catalyst versions
*/
if (!elf_flagelf(e, ELF_C_SET, ELF_F_LAYOUT))
{
mw_printf("elf_flagelf() failed: %s\n", elf_errmsg(-1));
return 1;
}
if (elf_update(e, ELF_C_NULL) < 0)
{
mw_printf("elf_update(NULL) failed: %s\n", elf_errmsg(-1));
return 1;
}
}
if (verboseDebug)
{
printf("Section %u %s\n", (unsigned int) elf_ndxscn(scn), name);
}
}
if (elf_update(e, ELF_C_WRITE) < 0)
{
mw_printf("elf_update(ELF_C_WRITE) failed: %s\n", elf_errmsg(-1));
return 1;
}
return 0;
}
