int
_rtld_tls_offset_allocate(Obj_Entry *obj)
{
size_t offset, next_offset;
if (obj->tls_done)
return 0;
if (obj->tlssize == 0) {
obj->tlsoffset = 0;
obj->tls_done = 1;
return 0;
}
#ifdef __HAVE_TLS_VARIANT_I
offset = roundup2(_rtld_tls_static_offset, obj->tlsalign);
next_offset = offset + obj->tlssize;
#else
offset = roundup2(_rtld_tls_static_offset + obj->tlssize,
obj->tlsalign);
next_offset = offset;
#endif
/*
* Check if the static allocation was already done.
* This happens if dynamically loaded modules want to use
* static TLS space.
*
* XXX Keep an actual free list and callbacks for initialisation.
*/
if (_rtld_tls_static_space) {
if (obj->tlsinitsize) {
_rtld_error("%s: Use of initialized "
"Thread Local Storage with model initial-exec "
"and dlopen is not supported",
obj->path);
return -1;
}
if (next_offset > _rtld_tls_static_space) {
_rtld_error("%s: No space available "
"for static Thread Local Storage",
obj->path);
return -1;
}
}
obj->tlsoffset = offset;
_rtld_tls_static_offset = next_offset;
obj->tls_done = 1;
return 0;
}
/*
* Process the PLT relocations.
*/
int
reloc_plt(Obj_Entry *obj, int flags, RtldLockState *lockstate)
{
const Elf_Rela *relalim;
const Elf_Rela *rela;
relalim = (const Elf_Rela *)((const char *)obj->pltrela +
obj->pltrelasize);
for (rela = obj->pltrela; rela < relalim; rela++) {
Elf_Addr *where;
where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
switch(ELF_R_TYPE(rela->r_info)) {
case R_AARCH64_JUMP_SLOT:
*where += (Elf_Addr)obj->relocbase;
break;
case R_AARCH64_TLSDESC:
reloc_tlsdesc(obj, rela, where, SYMLOOK_IN_PLT | flags,
lockstate);
break;
case R_AARCH64_IRELATIVE:
obj->irelative = true;
break;
case R_AARCH64_NONE:
break;
default:
_rtld_error("Unknown relocation type %u in PLT",
(unsigned int)ELF_R_TYPE(rela->r_info));
return (-1);
}
}
return (0);
}
/* Process the PLT relocations. */
int
reloc_plt(Obj_Entry *obj)
{
const Elf_Rel *rellim;
const Elf_Rel *rel;
rellim = (const Elf_Rel *)((char *)obj->pltrel + obj->pltrelsize);
for (rel = obj->pltrel; rel < rellim; rel++) {
Elf_Addr *where/*, val*/;
switch (ELF_R_TYPE(rel->r_info)) {
case R_386_JMP_SLOT:
/* Relocate the GOT slot pointing into the PLT. */
where = (Elf_Addr *)(obj->relocbase + rel->r_offset);
*where += (Elf_Addr)obj->relocbase;
break;
case R_386_IRELATIVE:
obj->irelative = true;
break;
default:
_rtld_error("Unknown relocation type %x in PLT",
ELF_R_TYPE(rel->r_info));
return (-1);
}
}
return 0;
}
static int
_rtld_do_copy_relocation(const Obj_Entry *dstobj, const Elf_Rela *rela)
{
void *dstaddr = (void *)(dstobj->relocbase + rela->r_offset);
const Elf_Sym *dstsym = dstobj->symtab + ELF_R_SYM(rela->r_info);
const char *name = dstobj->strtab + dstsym->st_name;
unsigned long hash = _rtld_elf_hash(name);
size_t size = dstsym->st_size;
const void *srcaddr;
const Elf_Sym *srcsym = NULL;
Obj_Entry *srcobj;
for (srcobj = dstobj->next; srcobj != NULL; srcobj = srcobj->next)
if ((srcsym = _rtld_symlook_obj(name, hash, srcobj, false)) != NULL)
break;
if (srcobj == NULL) {
_rtld_error("Undefined symbol \"%s\" referenced from COPY"
" relocation in %s", name, dstobj->path);
return (-1);
}
srcaddr = (const void *)(srcobj->relocbase + srcsym->st_value);
(void)memcpy(dstaddr, srcaddr, size);
rdbg(("COPY %s %s %s --> src=%p dst=%p size %ld",
dstobj->path, srcobj->path, name, srcaddr,
(void *)dstaddr, (long)size));
return (0);
}
/* Process the PLT relocations. */
int
reloc_plt(Obj_Entry *obj)
{
const Elf_Rela *relalim;
const Elf_Rela *rela;
relalim = (const Elf_Rela *)((char *)obj->pltrela + obj->pltrelasize);
for (rela = obj->pltrela; rela < relalim; rela++) {
Elf_Addr *where;
switch(ELF_R_TYPE(rela->r_info)) {
case R_X86_64_JMP_SLOT:
/* Relocate the GOT slot pointing into the PLT. */
where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
*where += (Elf_Addr)obj->relocbase;
break;
case R_X86_64_IRELATIVE:
obj->irelative = true;
break;
default:
_rtld_error("Unknown relocation type %x in PLT",
(unsigned int)ELF_R_TYPE(rela->r_info));
return (-1);
}
}
return 0;
}
static Elf_Ehdr *
get_elf_header(int fd, const char *path)
{
Elf_Ehdr *hdr;
/* DragonFly mmap does not have MAP_PREFAULT_READ */
hdr = mmap(NULL, PAGE_SIZE, PROT_READ, MAP_PRIVATE, fd, 0);
if (hdr == (Elf_Ehdr *)MAP_FAILED) {
_rtld_error("%s: read error: %s", path, rtld_strerror(errno));
return (NULL);
}
/* Make sure the file is valid */
if (!IS_ELF(*hdr)) {
_rtld_error("%s: invalid file format", path);
goto error;
}
if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS ||
hdr->e_ident[EI_DATA] != ELF_TARG_DATA) {
_rtld_error("%s: unsupported file layout", path);
goto error;
}
if (hdr->e_ident[EI_VERSION] != EV_CURRENT ||
hdr->e_version != EV_CURRENT) {
_rtld_error("%s: unsupported file version", path);
goto error;
}
if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN) {
_rtld_error("%s: unsupported file type", path);
goto error;
}
if (hdr->e_machine != ELF_TARG_MACH) {
_rtld_error("%s: unsupported machine", path);
goto error;
}
/*
* We rely on the program header being in the first page. This is
* not strictly required by the ABI specification, but it seems to
* always true in practice. And, it simplifies things considerably.
*/
if (hdr->e_phentsize != sizeof(Elf_Phdr)) {
_rtld_error(
"%s: invalid shared object: e_phentsize != sizeof(Elf_Phdr)", path);
goto error;
}
if (hdr->e_phoff + hdr->e_phnum * sizeof(Elf_Phdr) >
(size_t)PAGE_SIZE) {
_rtld_error("%s: program header too large", path);
goto error;
}
return (hdr);
error:
munmap(hdr, PAGE_SIZE);
return (NULL);
}
static Elf_Ehdr *
get_elf_header (int fd, const char *path)
{
static union {
Elf_Ehdr hdr;
char buf[PAGE_SIZE];
} u;
ssize_t nbytes;
if ((nbytes = pread(fd, u.buf, PAGE_SIZE, 0)) == -1) {
_rtld_error("%s: read error: %s", path, strerror(errno));
return NULL;
}
/* Make sure the file is valid */
if (nbytes < (ssize_t)sizeof(Elf_Ehdr) || !IS_ELF(u.hdr)) {
_rtld_error("%s: invalid file format", path);
return NULL;
}
if (u.hdr.e_ident[EI_CLASS] != ELF_TARG_CLASS
|| u.hdr.e_ident[EI_DATA] != ELF_TARG_DATA) {
_rtld_error("%s: unsupported file layout", path);
return NULL;
}
if (u.hdr.e_ident[EI_VERSION] != EV_CURRENT
|| u.hdr.e_version != EV_CURRENT) {
_rtld_error("%s: unsupported file version", path);
return NULL;
}
if (u.hdr.e_type != ET_EXEC && u.hdr.e_type != ET_DYN) {
_rtld_error("%s: unsupported file type", path);
return NULL;
}
if (u.hdr.e_machine != ELF_TARG_MACH) {
_rtld_error("%s: unsupported machine", path);
return NULL;
}
/*
* We rely on the program header being in the first page. This is
* not strictly required by the ABI specification, but it seems to
* always true in practice. And, it simplifies things considerably.
*/
if (u.hdr.e_phentsize != sizeof(Elf_Phdr)) {
_rtld_error(
"%s: invalid shared object: e_phentsize != sizeof(Elf_Phdr)", path);
return NULL;
}
if (u.hdr.e_phoff + u.hdr.e_phnum * sizeof(Elf_Phdr) > (size_t)nbytes) {
_rtld_error("%s: program header too large", path);
return NULL;
}
return (&u.hdr);
}
int
do_copy_relocations(Obj_Entry *dstobj)
{
const Obj_Entry *srcobj, *defobj;
const Elf_Rel *rellim;
const Elf_Rel *rel;
const Elf_Sym *srcsym;
const Elf_Sym *dstsym;
const void *srcaddr;
const char *name;
void *dstaddr;
SymLook req;
size_t size;
int res;
/*
* COPY relocs are invalid outside of the main program
*/
assert(dstobj->mainprog);
rellim = (const Elf_Rel *)((const char *)dstobj->rel + dstobj->relsize);
for (rel = dstobj->rel; rel < rellim; rel++) {
if (ELF_R_TYPE(rel->r_info) != R_MIPS_COPY)
continue;
dstaddr = (void *)(dstobj->relocbase + rel->r_offset);
dstsym = dstobj->symtab + ELF_R_SYM(rel->r_info);
name = dstobj->strtab + dstsym->st_name;
size = dstsym->st_size;
symlook_init(&req, name);
req.ventry = fetch_ventry(dstobj, ELF_R_SYM(rel->r_info));
req.flags = SYMLOOK_EARLY;
for (srcobj = globallist_next(dstobj); srcobj != NULL;
srcobj = globallist_next(srcobj)) {
res = symlook_obj(&req, srcobj);
if (res == 0) {
srcsym = req.sym_out;
defobj = req.defobj_out;
break;
}
}
if (srcobj == NULL) {
_rtld_error(
"Undefined symbol \"%s\" referenced from COPY relocation in %s",
name, dstobj->path);
return (-1);
}
srcaddr = (const void *)(defobj->relocbase + srcsym->st_value);
memcpy(dstaddr, srcaddr, size);
}
return (0);
}
void *
libc_dlopen(const char *path, int mode)
{
if (__libc_restricted_mode) {
_rtld_error("Service unavailable -- libc in restricted mode");
return (NULL);
} else
return (dlopen(path, mode));
}
static void Pread(void *addr, size_t size, int fd, off_t off)
{
int s;
if((s=pread(fd,addr, size, off)) < 0) {
_rtld_error("pread failed");
exit(1);
}
#if MINIXVERBOSE
fprintf(stderr, "read 0x%lx bytes from offset 0x%lx to addr 0x%lx\n", size, off, addr);
#endif
}
/*
* Process the special R_X86_64_COPY relocations in the main program. These
* copy data from a shared object into a region in the main program's BSS
* segment.
*
* Returns 0 on success, -1 on failure.
*/
int
do_copy_relocations(Obj_Entry *dstobj)
{
const Elf_Rela *relalim;
const Elf_Rela *rela;
assert(dstobj->mainprog); /* COPY relocations are invalid elsewhere */
relalim = (const Elf_Rela *) ((caddr_t) dstobj->rela + dstobj->relasize);
for (rela = dstobj->rela; rela < relalim; rela++) {
if (ELF_R_TYPE(rela->r_info) == R_X86_64_COPY) {
void *dstaddr;
const Elf_Sym *dstsym;
const char *name;
size_t size;
const void *srcaddr;
const Elf_Sym *srcsym;
const Obj_Entry *srcobj, *defobj;
SymLook req;
int res;
dstaddr = (void *) (dstobj->relocbase + rela->r_offset);
dstsym = dstobj->symtab + ELF_R_SYM(rela->r_info);
name = dstobj->strtab + dstsym->st_name;
size = dstsym->st_size;
symlook_init(&req, name);
req.ventry = fetch_ventry(dstobj, ELF_R_SYM(rela->r_info));
req.flags = SYMLOOK_EARLY;
for (srcobj = globallist_next(dstobj); srcobj != NULL;
srcobj = globallist_next(srcobj)) {
res = symlook_obj(&req, srcobj);
if (res == 0) {
srcsym = req.sym_out;
defobj = req.defobj_out;
break;
}
}
if (srcobj == NULL) {
_rtld_error("Undefined symbol \"%s\" referenced from COPY"
" relocation in %s", name, dstobj->path);
return -1;
}
srcaddr = (const void *) (defobj->relocbase + srcsym->st_value);
memcpy(dstaddr, srcaddr, size);
}
}
return 0;
}
static Elf_Ehdr *
get_elf_header (const char *path, char *buf, ssize_t nbytes)
{
Elf_Ehdr hdr = *(Elf_Ehdr *)buf;
/* Make sure the file is valid */
if (nbytes < (ssize_t)sizeof(Elf_Ehdr) || !IS_ELF(hdr)) {
_rtld_error("%s: invalid file format", path);
return NULL;
}
if (hdr.e_ident[EI_CLASS] != ELF_TARG_CLASS
|| hdr.e_ident[EI_DATA] != ELF_TARG_DATA) {
_rtld_error("%s: unsupported file layout", path);
return NULL;
}
if (hdr.e_ident[EI_VERSION] != EV_CURRENT
|| hdr.e_version != EV_CURRENT) {
_rtld_error("%s: unsupported file version", path);
return NULL;
}
if (hdr.e_type != ET_EXEC && hdr.e_type != ET_DYN) {
_rtld_error("%s: unsupported file type", path);
return NULL;
}
if (hdr.e_machine != ELF_TARG_MACH) {
_rtld_error("%s: unsupported machine", path);
return NULL;
}
/*
* We rely on the program header being in the first page. This is
* not strictly required by the ABI specification, but it seems to
* always true in practice. And, it simplifies things considerably.
*/
if (hdr.e_phentsize != sizeof(Elf_Phdr)) {
_rtld_error(
"%s: invalid shared object: e_phentsize != sizeof(Elf_Phdr)", path);
return NULL;
}
if (hdr.e_phoff + hdr.e_phnum * sizeof(Elf_Phdr) > (size_t)nbytes) {
_rtld_error("%s: program header too large", path);
return NULL;
}
return (Elf_Ehdr *)buf;
}
/*
* Process the special R_386_COPY relocations in the main program. These
* copy data from a shared object into a region in the main program's BSS
* segment.
*
* Returns 0 on success, -1 on failure.
*/
int
do_copy_relocations(Obj_Entry *dstobj)
{
const Elf_Rel *rellim;
const Elf_Rel *rel;
assert(dstobj->mainprog); /* COPY relocations are invalid elsewhere */
rellim = (const Elf_Rel *) ((caddr_t) dstobj->rel + dstobj->relsize);
for (rel = dstobj->rel; rel < rellim; rel++) {
if (ELF_R_TYPE(rel->r_info) == R_386_COPY) {
void *dstaddr;
const Elf_Sym *dstsym;
const char *name;
unsigned long hash;
size_t size;
const void *srcaddr;
const Elf_Sym *srcsym;
Obj_Entry *srcobj;
dstaddr = (void *) (dstobj->relocbase + rel->r_offset);
dstsym = dstobj->symtab + ELF_R_SYM(rel->r_info);
name = dstobj->strtab + dstsym->st_name;
hash = elf_hash(name);
size = dstsym->st_size;
for (srcobj = dstobj->next; srcobj != NULL; srcobj = srcobj->next)
if ((srcsym = symlook_obj(name, hash, srcobj, false)) != NULL)
break;
if (srcobj == NULL) {
_rtld_error("Undefined symbol \"%s\" referenced from COPY"
" relocation in %s", name, dstobj->path);
return -1;
}
srcaddr = (const void *) (srcobj->relocbase + srcsym->st_value);
memcpy(dstaddr, srcaddr, size);
}
}
return 0;
}
/* Relocate the jump slots in an object. */
int
reloc_jmpslots(Obj_Entry *obj, int flags, RtldLockState *lockstate)
{
const Elf_Rel *rellim;
const Elf_Rel *rel;
if (obj->jmpslots_done)
return 0;
rellim = (const Elf_Rel *)((char *)obj->pltrel + obj->pltrelsize);
for (rel = obj->pltrel; rel < rellim; rel++) {
Elf_Addr *where, target;
const Elf_Sym *def;
const Obj_Entry *defobj;
switch (ELF_R_TYPE(rel->r_info)) {
case R_386_JMP_SLOT:
where = (Elf_Addr *)(obj->relocbase + rel->r_offset);
def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj,
SYMLOOK_IN_PLT | flags, NULL, lockstate);
if (def == NULL)
return (-1);
if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) {
obj->gnu_ifunc = true;
continue;
}
target = (Elf_Addr)(defobj->relocbase + def->st_value);
reloc_jmpslot(where, target, defobj, obj, rel);
break;
case R_386_IRELATIVE:
break;
default:
_rtld_error("Unknown relocation type %x in PLT",
ELF_R_TYPE(rel->r_info));
return (-1);
}
}
obj->jmpslots_done = true;
return 0;
}
void *
_rtld_tls_module_allocate(size_t idx)
{
Obj_Entry *obj;
uint8_t *p;
for (obj = _rtld_objlist; obj != NULL; obj = obj->next) {
if (obj->tlsindex == idx)
break;
}
if (obj == NULL) {
_rtld_error("Module for TLS index %zu missing", idx);
_rtld_die();
}
p = xmalloc(obj->tlssize);
memcpy(p, obj->tlsinit, obj->tlsinitsize);
memset(p + obj->tlsinitsize, 0, obj->tlssize - obj->tlsinitsize);
return p;
}
Elf_Addr
_mips_rtld_bind(Obj_Entry *obj, Elf_Size reloff)
{
Elf_Addr *got = obj->pltgot;
const Elf_Sym *def;
const Obj_Entry *defobj;
Elf_Addr target;
def = find_symdef(reloff, obj, &defobj, SYMLOOK_IN_PLT, NULL,
NULL);
if (def == NULL)
_rtld_error("bind failed no symbol");
target = (Elf_Addr)(defobj->relocbase + def->st_value);
dbg("bind now/fixup at %s sym # %jd in %s --> was=%p new=%p",
obj->path,
(intmax_t)reloff, defobj->strtab + def->st_name,
(void *)got[obj->local_gotno + reloff - obj->gotsym],
(void *)target);
got[obj->local_gotno + reloff - obj->gotsym] = target;
return (Elf_Addr)target;
}
/* Process the non-PLT relocations. */
int
reloc_non_plt(Obj_Entry *obj, Obj_Entry *obj_rtld, int flags,
RtldLockState *lockstate)
{
const Elf_Rela *relalim;
const Elf_Rela *rela;
SymCache *cache;
const Elf_Sym *def;
const Obj_Entry *defobj;
Elf_Addr *where, symval;
Elf32_Addr *where32;
int r;
r = -1;
/*
* The dynamic loader may be called from a thread, we have
* limited amounts of stack available so we cannot use alloca().
*/
if (obj != obj_rtld) {
cache = calloc(obj->dynsymcount, sizeof(SymCache));
/* No need to check for NULL here */
} else
cache = NULL;
relalim = (const Elf_Rela *)((caddr_t)obj->rela + obj->relasize);
for (rela = obj->rela; rela < relalim; rela++) {
/*
* First, resolve symbol for relocations which
* reference symbols.
*/
switch (ELF_R_TYPE(rela->r_info)) {
case R_X86_64_64:
case R_X86_64_PC32:
case R_X86_64_GLOB_DAT:
case R_X86_64_TPOFF64:
case R_X86_64_TPOFF32:
case R_X86_64_DTPMOD64:
case R_X86_64_DTPOFF64:
case R_X86_64_DTPOFF32:
def = find_symdef(ELF_R_SYM(rela->r_info), obj,
&defobj, flags, cache, lockstate);
if (def == NULL)
goto done;
/*
* If symbol is IFUNC, only perform relocation
* when caller allowed it by passing
* SYMLOOK_IFUNC flag. Skip the relocations
* otherwise.
*
* Also error out in case IFUNC relocations
* are specified for TLS, which cannot be
* usefully interpreted.
*/
if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) {
switch (ELF_R_TYPE(rela->r_info)) {
case R_X86_64_64:
case R_X86_64_PC32:
case R_X86_64_GLOB_DAT:
if ((flags & SYMLOOK_IFUNC) == 0) {
obj->non_plt_gnu_ifunc = true;
continue;
}
symval = (Elf_Addr)rtld_resolve_ifunc(
defobj, def);
break;
case R_X86_64_TPOFF64:
case R_X86_64_TPOFF32:
case R_X86_64_DTPMOD64:
case R_X86_64_DTPOFF64:
case R_X86_64_DTPOFF32:
_rtld_error("%s: IFUNC for TLS reloc",
obj->path);
goto done;
}
} else {
if ((flags & SYMLOOK_IFUNC) != 0)
continue;
symval = (Elf_Addr)defobj->relocbase +
def->st_value;
}
break;
default:
if ((flags & SYMLOOK_IFUNC) != 0)
continue;
break;
}
where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
where32 = (Elf32_Addr *)where;
switch (ELF_R_TYPE(rela->r_info)) {
case R_X86_64_NONE:
break;
case R_X86_64_64:
*where = symval + rela->r_addend;
break;
case R_X86_64_PC32:
/*
* I don't think the dynamic linker should
* ever see this type of relocation. But the
* binutils-2.6 tools sometimes generate it.
*/
*where32 = (Elf32_Addr)(unsigned long)(symval +
rela->r_addend - (Elf_Addr)where);
break;
/* missing: R_X86_64_GOT32 R_X86_64_PLT32 */
case R_X86_64_COPY:
/*
* These are deferred until all other relocations have
* been done. All we do here is make sure that the COPY
* relocation is not in a shared library. They are
* allowed only in executable files.
*/
if (!obj->mainprog) {
_rtld_error("%s: Unexpected R_X86_64_COPY "
"relocation in shared library", obj->path);
goto done;
}
break;
case R_X86_64_GLOB_DAT:
*where = symval;
break;
case R_X86_64_TPOFF64:
/*
* We lazily allocate offsets for static TLS
* as we see the first relocation that
* references the TLS block. This allows us to
* support (small amounts of) static TLS in
* dynamically loaded modules. If we run out
* of space, we generate an error.
*/
if (!defobj->tls_done) {
if (!allocate_tls_offset((Obj_Entry*) defobj)) {
_rtld_error("%s: No space available "
"for static Thread Local Storage",
obj->path);
goto done;
}
}
*where = (Elf_Addr)(def->st_value - defobj->tlsoffset +
rela->r_addend);
break;
case R_X86_64_TPOFF32:
/*
* We lazily allocate offsets for static TLS
* as we see the first relocation that
* references the TLS block. This allows us to
* support (small amounts of) static TLS in
* dynamically loaded modules. If we run out
* of space, we generate an error.
*/
if (!defobj->tls_done) {
if (!allocate_tls_offset((Obj_Entry*) defobj)) {
_rtld_error("%s: No space available "
"for static Thread Local Storage",
obj->path);
goto done;
}
}
*where32 = (Elf32_Addr)(def->st_value -
defobj->tlsoffset + rela->r_addend);
break;
case R_X86_64_DTPMOD64:
*where += (Elf_Addr)defobj->tlsindex;
break;
case R_X86_64_DTPOFF64:
*where += (Elf_Addr)(def->st_value + rela->r_addend);
break;
case R_X86_64_DTPOFF32:
*where32 += (Elf32_Addr)(def->st_value +
rela->r_addend);
break;
case R_X86_64_RELATIVE:
*where = (Elf_Addr)(obj->relocbase + rela->r_addend);
break;
/*
* missing:
* R_X86_64_GOTPCREL, R_X86_64_32, R_X86_64_32S, R_X86_64_16,
* R_X86_64_PC16, R_X86_64_8, R_X86_64_PC8
*/
default:
_rtld_error("%s: Unsupported relocation type %u"
" in non-PLT relocations\n", obj->path,
(unsigned int)ELF_R_TYPE(rela->r_info));
goto done;
}
}
r = 0;
done:
free(cache);
return (r);
}
int
_rtld_relocate_nonplt_objects(Obj_Entry *obj)
{
for (const Elf_Rela *rela = obj->rela; rela < obj->relalim; rela++) {
Elf_Addr *where;
const Elf_Sym *def;
const Obj_Entry *defobj;
unsigned long symnum;
Elf_Addr addend;
where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
symnum = ELF_R_SYM(rela->r_info);
addend = rela->r_addend;
switch (ELF_R_TYPE(rela->r_info)) {
case R_TYPE(NONE):
break;
case R_TYPE(ABS64): /* word B + S + A */
case R_TYPE(GLOB_DAT): /* word B + S */
def = _rtld_find_symdef(symnum, obj, &defobj, false);
if (def == NULL)
return -1;
*where = addend + (Elf_Addr)defobj->relocbase +
def->st_value;
rdbg(("ABS64/GLOB_DAT %s in %s --> %p @ %p in %s",
obj->strtab + obj->symtab[symnum].st_name,
obj->path, (void *)tmp, where, defobj->path));
break;
case R_TYPE(RELATIVE): /* word B + A */
*where = addend + (Elf_Addr)obj->relocbase;
rdbg(("RELATIVE in %s --> %p", obj->path,
(void *)tmp));
break;
case R_TYPE(COPY):
/*
* These are deferred until all other relocations have
* been done. All we do here is make sure that the
* COPY relocation is not in a shared library. They
* are allowed only in executable files.
*/
if (obj->isdynamic) {
_rtld_error(
"%s: Unexpected R_COPY relocation in shared library",
obj->path);
return -1;
}
rdbg(("COPY (avoid in main)"));
break;
case R_TLS_TYPE(TLS_DTPREL):
def = _rtld_find_symdef(symnum, obj, &defobj, false);
if (def == NULL)
return -1;
*where = addend + (Elf_Addr)(def->st_value);
rdbg(("TLS_DTPOFF32 %s in %s --> %p",
obj->strtab + obj->symtab[symnum].st_name,
obj->path, (void *)tmp));
break;
case R_TLS_TYPE(TLS_DTPMOD):
def = _rtld_find_symdef(symnum, obj, &defobj, false);
if (def == NULL)
return -1;
*where = (Elf_Addr)(defobj->tlsindex);
rdbg(("TLS_DTPMOD %s in %s --> %p",
obj->strtab + obj->symtab[symnum].st_name,
obj->path, (void *)tmp));
break;
case R_TLS_TYPE(TLS_TPREL):
def = _rtld_find_symdef(symnum, obj, &defobj, false);
if (def == NULL)
return -1;
if (!defobj->tls_done &&
_rtld_tls_offset_allocate(obj))
return -1;
*where = (Elf_Addr)def->st_value + defobj->tlsoffset +
sizeof(struct tls_tcb);
rdbg(("TLS_TPOFF32 %s in %s --> %p",
obj->strtab + obj->symtab[symnum].st_name,
obj->path, (void *)tmp));
break;
default:
rdbg(("sym = %lu, type = %lu, offset = %p, "
"contents = %p, symbol = %s",
symnum, (u_long)ELF_R_TYPE(rela->r_info),
(void *)rela->r_offset, *where,
obj->strtab + obj->symtab[symnum].st_name));
_rtld_error("%s: Unsupported relocation type %ld "
"in non-PLT relocations",
obj->path, (u_long) ELF_R_TYPE(rela->r_info));
return -1;
}
}
return 0;
}
/*
* Load a shared object into memory, if it is not already loaded.
*
* Returns a pointer to the Obj_Entry for the object. Returns NULL
* on failure.
*/
Obj_Entry *
_rtld_load_object(const char *filepath, int flags)
{
Obj_Entry *obj;
int fd = -1;
struct stat sb;
size_t pathlen = strlen(filepath);
for (obj = _rtld_objlist->next; obj != NULL; obj = obj->next)
if (pathlen == obj->pathlen && !strcmp(obj->path, filepath))
break;
/*
* If we didn't find a match by pathname, open the file and check
* again by device and inode. This avoids false mismatches caused
* by multiple links or ".." in pathnames.
*
* To avoid a race, we open the file and use fstat() rather than
* using stat().
*/
if (obj == NULL) {
if ((fd = open(filepath, O_RDONLY)) == -1) {
_rtld_error("Cannot open \"%s\"", filepath);
return NULL;
}
if (fstat(fd, &sb) == -1) {
_rtld_error("Cannot fstat \"%s\"", filepath);
close(fd);
return NULL;
}
for (obj = _rtld_objlist->next; obj != NULL; obj = obj->next) {
if (obj->ino == sb.st_ino && obj->dev == sb.st_dev) {
close(fd);
break;
}
}
}
if (obj == NULL) { /* First use of this object, so we must map it in */
obj = _rtld_map_object(filepath, fd, &sb);
(void)close(fd);
if (obj == NULL)
return NULL;
_rtld_digest_dynamic(filepath, obj);
if (flags & _RTLD_DLOPEN) {
if (obj->z_noopen || (flags & _RTLD_NOLOAD)) {
dbg(("refusing to load non-loadable \"%s\"",
obj->path));
_rtld_error("Cannot dlopen non-loadable %s",
obj->path);
munmap(obj->mapbase, obj->mapsize);
_rtld_obj_free(obj);
return OBJ_ERR;
}
}
*_rtld_objtail = obj;
_rtld_objtail = &obj->next;
_rtld_objcount++;
_rtld_objloads++;
#ifdef RTLD_LOADER
_rtld_linkmap_add(obj); /* for GDB */
#endif
dbg((" %p .. %p: %s", obj->mapbase,
obj->mapbase + obj->mapsize - 1, obj->path));
if (obj->textrel)
dbg((" WARNING: %s has impure text", obj->path));
}
++obj->refcount;
#ifdef RTLD_LOADER
if (flags & _RTLD_MAIN && !obj->mainref) {
obj->mainref = 1;
dbg(("adding %p (%s) to _rtld_list_main", obj, obj->path));
_rtld_objlist_push_tail(&_rtld_list_main, obj);
}
if (flags & _RTLD_GLOBAL && !obj->globalref) {
obj->globalref = 1;
dbg(("adding %p (%s) to _rtld_list_global", obj, obj->path));
_rtld_objlist_push_tail(&_rtld_list_global, obj);
}
#endif
return obj;
}
/* Process the non-PLT relocations. */
int
reloc_non_plt(Obj_Entry *obj, Obj_Entry *obj_rtld, int flags,
RtldLockState *lockstate)
{
const Elf_Rel *rellim;
const Elf_Rel *rel;
SymCache *cache;
const Elf_Sym *def;
const Obj_Entry *defobj;
Elf_Addr *where, symval, add;
int r;
r = -1;
/*
* The dynamic loader may be called from a thread, we have
* limited amounts of stack available so we cannot use alloca().
*/
if (obj != obj_rtld) {
cache = calloc(obj->dynsymcount, sizeof(SymCache));
/* No need to check for NULL here */
} else
cache = NULL;
rellim = (const Elf_Rel *)((caddr_t) obj->rel + obj->relsize);
for (rel = obj->rel; rel < rellim; rel++) {
switch (ELF_R_TYPE(rel->r_info)) {
case R_386_32:
case R_386_PC32:
case R_386_GLOB_DAT:
case R_386_TLS_TPOFF:
case R_386_TLS_TPOFF32:
case R_386_TLS_DTPMOD32:
case R_386_TLS_DTPOFF32:
def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj,
flags, cache, lockstate);
if (def == NULL)
goto done;
if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) {
switch (ELF_R_TYPE(rel->r_info)) {
case R_386_32:
case R_386_PC32:
case R_386_GLOB_DAT:
if ((flags & SYMLOOK_IFUNC) == 0) {
obj->non_plt_gnu_ifunc = true;
continue;
}
symval = (Elf_Addr)rtld_resolve_ifunc(
defobj, def);
break;
case R_386_TLS_TPOFF:
case R_386_TLS_TPOFF32:
case R_386_TLS_DTPMOD32:
case R_386_TLS_DTPOFF32:
_rtld_error("%s: IFUNC for TLS reloc",
obj->path);
goto done;
}
} else {
if ((flags & SYMLOOK_IFUNC) != 0)
continue;
symval = (Elf_Addr)defobj->relocbase +
def->st_value;
}
break;
default:
if ((flags & SYMLOOK_IFUNC) != 0)
continue;
break;
}
where = (Elf_Addr *)(obj->relocbase + rel->r_offset);
switch (ELF_R_TYPE(rel->r_info)) {
case R_386_NONE:
break;
case R_386_32:
*where += symval;
break;
case R_386_PC32:
/*
* I don't think the dynamic linker should ever
* see this type of relocation. But the
* binutils-2.6 tools sometimes generate it.
*/
*where += symval - (Elf_Addr)where;
break;
case R_386_COPY:
/*
* These are deferred until all other
* relocations have been done. All we do here
* is make sure that the COPY relocation is
* not in a shared library. They are allowed
* only in executable files.
*/
if (!obj->mainprog) {
_rtld_error("%s: Unexpected R_386_COPY "
"relocation in shared library", obj->path);
goto done;
}
break;
case R_386_GLOB_DAT:
*where = symval;
break;
case R_386_RELATIVE:
*where += (Elf_Addr)obj->relocbase;
break;
case R_386_TLS_TPOFF:
case R_386_TLS_TPOFF32:
/*
* We lazily allocate offsets for static TLS
* as we see the first relocation that
* references the TLS block. This allows us to
* support (small amounts of) static TLS in
* dynamically loaded modules. If we run out
* of space, we generate an error.
*/
if (!defobj->tls_done) {
if (!allocate_tls_offset((Obj_Entry*) defobj)) {
_rtld_error("%s: No space available "
"for static Thread Local Storage",
obj->path);
goto done;
}
}
add = (Elf_Addr)(def->st_value - defobj->tlsoffset);
if (ELF_R_TYPE(rel->r_info) == R_386_TLS_TPOFF)
*where += add;
else
*where -= add;
break;
case R_386_TLS_DTPMOD32:
*where += (Elf_Addr)defobj->tlsindex;
break;
case R_386_TLS_DTPOFF32:
*where += (Elf_Addr) def->st_value;
break;
default:
_rtld_error("%s: Unsupported relocation type %d"
" in non-PLT relocations\n", obj->path,
ELF_R_TYPE(rel->r_info));
goto done;
}
}
r = 0;
done:
free(cache);
return (r);
}
static int
reloc_nonplt_object(Obj_Entry *obj, const Elf_Rel *rel, SymCache *cache,
RtldLockState *lockstate)
{
Elf_Addr *where;
const Elf_Sym *def;
const Obj_Entry *defobj;
Elf_Addr tmp;
unsigned long symnum;
where = (Elf_Addr *)(obj->relocbase + rel->r_offset);
symnum = ELF_R_SYM(rel->r_info);
switch (ELF_R_TYPE(rel->r_info)) {
case R_ARM_NONE:
break;
#if 1 /* XXX should not occur */
case R_ARM_PC24: { /* word32 S - P + A */
Elf32_Sword addend;
/*
* Extract addend and sign-extend if needed.
*/
addend = *where;
if (addend & 0x00800000)
addend |= 0xff000000;
def = find_symdef(symnum, obj, &defobj, false, cache,
lockstate);
if (def == NULL)
return -1;
tmp = (Elf_Addr)obj->relocbase + def->st_value
- (Elf_Addr)where + (addend << 2);
if ((tmp & 0xfe000000) != 0xfe000000 &&
(tmp & 0xfe000000) != 0) {
_rtld_error(
"%s: R_ARM_PC24 relocation @ %p to %s failed "
"(displacement %ld (%#lx) out of range)",
obj->path, where,
obj->strtab + obj->symtab[symnum].st_name,
(long) tmp, (long) tmp);
return -1;
}
tmp >>= 2;
*where = (*where & 0xff000000) | (tmp & 0x00ffffff);
dbg("PC24 %s in %s --> %p @ %p in %s",
obj->strtab + obj->symtab[symnum].st_name,
obj->path, (void *)*where, where, defobj->path);
break;
}
#endif
case R_ARM_ABS32: /* word32 B + S + A */
case R_ARM_GLOB_DAT: /* word32 B + S */
def = find_symdef(symnum, obj, &defobj, false, cache,
lockstate);
if (def == NULL)
return -1;
if (__predict_true(RELOC_ALIGNED_P(where))) {
tmp = *where + (Elf_Addr)defobj->relocbase +
def->st_value;
*where = tmp;
} else {
tmp = load_ptr(where) +
(Elf_Addr)defobj->relocbase +
def->st_value;
store_ptr(where, tmp);
}
dbg("ABS32/GLOB_DAT %s in %s --> %p @ %p in %s",
obj->strtab + obj->symtab[symnum].st_name,
obj->path, (void *)tmp, where, defobj->path);
break;
case R_ARM_RELATIVE: /* word32 B + A */
if (__predict_true(RELOC_ALIGNED_P(where))) {
tmp = *where + (Elf_Addr)obj->relocbase;
*where = tmp;
} else {
tmp = load_ptr(where) +
(Elf_Addr)obj->relocbase;
store_ptr(where, tmp);
}
dbg("RELATIVE in %s --> %p", obj->path,
(void *)tmp);
break;
case R_ARM_COPY:
/*
* These are deferred until all other relocations have
* been done. All we do here is make sure that the
* COPY relocation is not in a shared library. They
* are allowed only in executable files.
*/
if (!obj->mainprog) {
_rtld_error(
"%s: Unexpected R_COPY relocation in shared library",
obj->path);
return -1;
}
dbg("COPY (avoid in main)");
break;
default:
dbg("sym = %lu, type = %lu, offset = %p, "
"contents = %p, symbol = %s",
symnum, (u_long)ELF_R_TYPE(rel->r_info),
(void *)rel->r_offset, (void *)load_ptr(where),
obj->strtab + obj->symtab[symnum].st_name);
_rtld_error("%s: Unsupported relocation type %ld "
"in non-PLT relocations\n",
obj->path, (u_long) ELF_R_TYPE(rel->r_info));
return -1;
}
return 0;
}
/*
* Map a shared object into memory. The "fd" argument is a file descriptor,
* which must be open on the object and positioned at its beginning.
* The "path" argument is a pathname that is used only for error messages.
*
* The return value is a pointer to a newly-allocated Obj_Entry structure
* for the shared object. Returns NULL on failure.
*/
Obj_Entry *
map_object(int fd, const char *path, const struct stat *sb)
{
Obj_Entry *obj;
Elf_Ehdr *hdr;
int i;
Elf_Phdr *phdr;
Elf_Phdr *phlimit;
Elf_Phdr **segs;
int nsegs;
Elf_Phdr *phdyn;
Elf_Phdr *phinterp;
Elf_Phdr *phtls;
caddr_t mapbase;
caddr_t shlib_base;
size_t mapsize;
Elf_Addr base_vaddr;
Elf_Addr base_vlimit;
caddr_t base_addr;
Elf_Off data_offset;
Elf_Addr data_vaddr;
Elf_Addr data_vlimit;
caddr_t data_addr;
int data_prot;
int data_flags;
Elf_Addr clear_vaddr;
caddr_t clear_addr;
caddr_t clear_page;
Elf_Addr phdr_vaddr;
size_t nclear, phsize;
Elf_Addr bss_vaddr;
Elf_Addr bss_vlimit;
caddr_t bss_addr;
Elf_Word stack_flags;
Elf_Addr relro_page;
size_t relro_size;
Elf_Addr note_start;
Elf_Addr note_end;
hdr = get_elf_header(fd, path);
if (hdr == NULL)
return (NULL);
if (__ld_sharedlib_base) {
shlib_base = (void *)(intptr_t)strtoul(__ld_sharedlib_base, NULL, 0);
} else {
shlib_base = NULL;
}
/*
* Scan the program header entries, and save key information.
*
* We expect that the loadable segments are ordered by load address.
*/
phdr = (Elf_Phdr *) ((char *)hdr + hdr->e_phoff);
phsize = hdr->e_phnum * sizeof (phdr[0]);
phlimit = phdr + hdr->e_phnum;
nsegs = -1;
phdyn = phinterp = phtls = NULL;
phdr_vaddr = 0;
relro_page = 0;
relro_size = 0;
note_start = 0;
note_end = 0;
segs = alloca(sizeof(segs[0]) * hdr->e_phnum);
stack_flags = RTLD_DEFAULT_STACK_PF_EXEC | PF_R | PF_W;
while (phdr < phlimit) {
switch (phdr->p_type) {
case PT_INTERP:
phinterp = phdr;
break;
case PT_LOAD:
segs[++nsegs] = phdr;
if ((segs[nsegs]->p_align & (PAGE_SIZE - 1)) != 0) {
_rtld_error("%s: PT_LOAD segment %d not page-aligned",
path, nsegs);
goto error;
}
break;
case PT_PHDR:
phdr_vaddr = phdr->p_vaddr;
phsize = phdr->p_memsz;
break;
case PT_DYNAMIC:
phdyn = phdr;
break;
case PT_TLS:
phtls = phdr;
break;
case PT_GNU_STACK:
stack_flags = phdr->p_flags;
break;
case PT_GNU_RELRO:
relro_page = phdr->p_vaddr;
relro_size = phdr->p_memsz;
break;
case PT_NOTE:
if (phdr->p_offset > PAGE_SIZE ||
phdr->p_offset + phdr->p_filesz > PAGE_SIZE)
break;
note_start = (Elf_Addr)(char *)hdr + phdr->p_offset;
note_end = note_start + phdr->p_filesz;
break;
}
++phdr;
}
if (phdyn == NULL) {
_rtld_error("%s: object is not dynamically-linked", path);
goto error;
}
if (nsegs < 0) {
_rtld_error("%s: too few PT_LOAD segments", path);
goto error;
}
/*
* Map the entire address space of the object, to stake out our
* contiguous region, and to establish the base address for relocation.
*/
base_vaddr = trunc_page(segs[0]->p_vaddr);
base_vlimit = round_page(segs[nsegs]->p_vaddr + segs[nsegs]->p_memsz);
mapsize = base_vlimit - base_vaddr;
base_addr = (caddr_t) base_vaddr;
if (base_addr == NULL && shlib_base) {
size_t limit = 1024 * 256 * 1024;
size_t offset;
for (offset = 0; offset < limit; offset += 256 * 1024) {
mapbase = mmap(shlib_base + offset, mapsize,
PROT_NONE,
MAP_ANON | MAP_PRIVATE | MAP_NOCORE |
MAP_TRYFIXED,
-1, 0);
if (mapbase != MAP_FAILED)
break;
}
} else {
mapbase = mmap(base_addr, mapsize,
PROT_NONE,
MAP_ANON | MAP_PRIVATE | MAP_NOCORE,
-1, 0);
}
if (mapbase == (caddr_t) -1) {
_rtld_error("%s: mmap of entire address space failed: %s",
path, rtld_strerror(errno));
goto error;
}
if (base_addr != NULL && mapbase != base_addr) {
_rtld_error("%s: mmap returned wrong address: wanted %p, got %p",
path, base_addr, mapbase);
goto error1;
}
for (i = 0; i <= nsegs; i++) {
/* Overlay the segment onto the proper region. */
data_offset = trunc_page(segs[i]->p_offset);
data_vaddr = trunc_page(segs[i]->p_vaddr);
data_vlimit = round_page(segs[i]->p_vaddr + segs[i]->p_filesz);
data_addr = mapbase + (data_vaddr - base_vaddr);
data_prot = convert_prot(segs[i]->p_flags);
data_flags = convert_flags(segs[i]->p_flags) | MAP_FIXED;
if (mmap(data_addr, data_vlimit - data_vaddr, data_prot,
data_flags, fd, data_offset) == (caddr_t) -1) {
_rtld_error("%s: mmap of data failed: %s", path,
rtld_strerror(errno));
goto error1;
}
/* Do BSS setup */
if (segs[i]->p_filesz != segs[i]->p_memsz) {
/* Clear any BSS in the last page of the segment. */
clear_vaddr = segs[i]->p_vaddr + segs[i]->p_filesz;
clear_addr = mapbase + (clear_vaddr - base_vaddr);
clear_page = mapbase + (trunc_page(clear_vaddr) - base_vaddr);
if ((nclear = data_vlimit - clear_vaddr) > 0) {
/* Make sure the end of the segment is writable */
if ((data_prot & PROT_WRITE) == 0 && -1 ==
mprotect(clear_page, PAGE_SIZE, data_prot|PROT_WRITE)) {
_rtld_error("%s: mprotect failed: %s", path,
rtld_strerror(errno));
goto error1;
}
memset(clear_addr, 0, nclear);
/*
* reset the data protection back, enable the segment to be
* coredumped since we modified it.
*/
if ((data_prot & PROT_WRITE) == 0) {
madvise(clear_page, PAGE_SIZE, MADV_CORE);
mprotect(clear_page, PAGE_SIZE, data_prot);
}
}
/* Overlay the BSS segment onto the proper region. */
bss_vaddr = data_vlimit;
bss_vlimit = round_page(segs[i]->p_vaddr + segs[i]->p_memsz);
bss_addr = mapbase + (bss_vaddr - base_vaddr);
if (bss_vlimit > bss_vaddr) { /* There is something to do */
if (mmap(bss_addr, bss_vlimit - bss_vaddr, data_prot,
data_flags | MAP_ANON, -1, 0) == (caddr_t)-1) {
_rtld_error("%s: mmap of bss failed: %s", path,
rtld_strerror(errno));
goto error1;
}
}
}
if (phdr_vaddr == 0 && data_offset <= hdr->e_phoff &&
(data_vlimit - data_vaddr + data_offset) >=
(hdr->e_phoff + hdr->e_phnum * sizeof (Elf_Phdr))) {
phdr_vaddr = data_vaddr + hdr->e_phoff - data_offset;
}
}
obj = obj_new();
if (sb != NULL) {
obj->dev = sb->st_dev;
obj->ino = sb->st_ino;
}
obj->mapbase = mapbase;
obj->mapsize = mapsize;
obj->textsize = round_page(segs[0]->p_vaddr + segs[0]->p_memsz) -
base_vaddr;
obj->vaddrbase = base_vaddr;
obj->relocbase = mapbase - base_vaddr;
obj->dynamic = (const Elf_Dyn *) (obj->relocbase + phdyn->p_vaddr);
if (hdr->e_entry != 0)
obj->entry = (caddr_t) (obj->relocbase + hdr->e_entry);
if (phdr_vaddr != 0) {
obj->phdr = (const Elf_Phdr *) (obj->relocbase + phdr_vaddr);
} else {
obj->phdr = malloc(phsize);
if (obj->phdr == NULL) {
obj_free(obj);
_rtld_error("%s: cannot allocate program header", path);
goto error1;
}
memcpy((char *)obj->phdr, (char *)hdr + hdr->e_phoff, phsize);
obj->phdr_alloc = true;
}
obj->phsize = phsize;
if (phinterp != NULL)
obj->interp = (const char *) (obj->relocbase + phinterp->p_vaddr);
if (phtls != NULL) {
tls_dtv_generation++;
obj->tlsindex = ++tls_max_index;
obj->tlssize = phtls->p_memsz;
obj->tlsalign = phtls->p_align;
obj->tlsinitsize = phtls->p_filesz;
obj->tlsinit = mapbase + phtls->p_vaddr;
}
obj->stack_flags = stack_flags;
if (relro_size) {
obj->relro_page = obj->relocbase + trunc_page(relro_page);
obj->relro_size = round_page(relro_size);
}
if (note_start < note_end)
digest_notes(obj, note_start, note_end);
munmap(hdr, PAGE_SIZE);
return (obj);
error1:
munmap(mapbase, mapsize);
error:
munmap(hdr, PAGE_SIZE);
return (NULL);
}
int
_rtld_relocate_nonplt_objects(Obj_Entry *obj)
{
const Elf_Rela *rela;
for (rela = obj->rela; rela < obj->relalim; rela++) {
Elf_Addr *where;
const Elf_Sym *def;
const Obj_Entry *defobj;
Elf_Addr tmp;
unsigned long symnum;
where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
symnum = ELF_R_SYM(rela->r_info);
switch (ELF_R_TYPE(rela->r_info)) {
case R_TYPE(NONE):
break;
case R_TYPE(32): /* word32 S + A */
case R_TYPE(GLOB_DAT): /* word32 S + A */
def = _rtld_find_symdef(symnum, obj, &defobj, false);
if (def == NULL)
return -1;
tmp = (Elf_Addr)(defobj->relocbase + def->st_value +
rela->r_addend);
if (*where != tmp)
*where = tmp;
rdbg(("32/GLOB_DAT %s in %s --> %p in %s",
obj->strtab + obj->symtab[symnum].st_name,
obj->path, (void *)*where, defobj->path));
break;
case R_TYPE(RELATIVE): /* word32 B + A */
tmp = (Elf_Addr)(obj->relocbase + rela->r_addend);
if (*where != tmp)
*where = tmp;
rdbg(("RELATIVE in %s --> %p", obj->path,
(void *)*where));
break;
case R_TYPE(COPY):
/*
* These are deferred until all other relocations have
* been done. All we do here is make sure that the
* COPY relocation is not in a shared library. They
* are allowed only in executable files.
*/
if (obj->isdynamic) {
_rtld_error(
"%s: Unexpected R_COPY relocation in shared library",
obj->path);
return -1;
}
rdbg(("COPY (avoid in main)"));
break;
default:
rdbg(("sym = %lu, type = %lu, offset = %p, "
"addend = %p, contents = %p, symbol = %s",
symnum, (u_long)ELF_R_TYPE(rela->r_info),
(void *)rela->r_offset, (void *)rela->r_addend,
(void *)*where,
obj->strtab + obj->symtab[symnum].st_name));
_rtld_error("%s: Unsupported relocation type %ld "
"in non-PLT relocations",
obj->path, (u_long) ELF_R_TYPE(rela->r_info));
return -1;
}
}
return 0;
}
/*
* Relocate newly-loaded shared objects. The argument is a pointer to
* the Obj_Entry for the first such object. All objects from the first
* to the end of the list of objects are relocated. Returns 0 on success,
* or -1 on failure.
*/
int
_rtld_relocate_objects(Obj_Entry *first, bool bind_now)
{
Obj_Entry *obj;
int ok = 1;
for (obj = first; obj != NULL; obj = obj->next) {
if (obj->nbuckets == 0 || obj->nchains == 0 ||
obj->buckets == NULL || obj->symtab == NULL ||
obj->strtab == NULL) {
_rtld_error("%s: Shared object has no run-time"
" symbol table", obj->path);
return -1;
}
if (obj->nbuckets == UINT32_MAX) {
_rtld_error("%s: Symbol table too large", obj->path);
return -1;
}
rdbg((" relocating %s (%ld/%ld rel/rela, %ld/%ld plt rel/rela)",
obj->path,
(long)(obj->rellim - obj->rel),
(long)(obj->relalim - obj->rela),
(long)(obj->pltrellim - obj->pltrel),
(long)(obj->pltrelalim - obj->pltrela)));
#ifndef __minix
if (obj->textrel) {
/*
* There are relocations to the write-protected text
* segment.
*/
if (mprotect(obj->mapbase, obj->textsize,
PROT_READ | PROT_WRITE | PROT_EXEC) == -1) {
_rtld_error("%s: Cannot write-enable text "
"segment: %s", obj->path, xstrerror(errno));
return -1;
}
}
#endif
dbg(("doing non-PLT relocations"));
if (_rtld_relocate_nonplt_objects(obj) < 0)
ok = 0;
#ifndef __minix
if (obj->textrel) { /* Re-protected the text segment. */
if (mprotect(obj->mapbase, obj->textsize,
PROT_READ | PROT_EXEC) == -1) {
_rtld_error("%s: Cannot write-protect text "
"segment: %s", obj->path, xstrerror(errno));
return -1;
}
}
#endif
dbg(("doing lazy PLT binding"));
if (_rtld_relocate_plt_lazy(obj) < 0)
ok = 0;
#if defined(__hppa__)
bind_now = 1;
#endif
if (obj->z_now || bind_now) {
dbg(("doing immediate PLT binding"));
if (_rtld_relocate_plt_objects(obj) < 0)
ok = 0;
}
if (!ok)
return -1;
/* Set some sanity-checking numbers in the Obj_Entry. */
obj->magic = RTLD_MAGIC;
obj->version = RTLD_VERSION;
/* Fill in the dynamic linker entry points. */
obj->dlopen = dlopen;
obj->dlsym = dlsym;
obj->dlerror = dlerror;
obj->dlclose = dlclose;
obj->dladdr = dladdr;
dbg(("fixing up PLTGOT"));
/* Set the special PLTGOT entries. */
if (obj->pltgot != NULL)
_rtld_setup_pltgot(obj);
}
return 0;
}
/*
* Map a shared object into memory. The argument is a file descriptor,
* which must be open on the object and positioned at its beginning.
*
* The return value is a pointer to a newly-allocated Obj_Entry structure
* for the shared object. Returns NULL on failure.
*/
Obj_Entry *
_rtld_map_object(const char *path, int fd, const struct stat *sb)
{
Obj_Entry *obj;
Elf_Ehdr *ehdr;
Elf_Phdr *phdr;
size_t phsize;
Elf_Phdr *phlimit;
Elf_Phdr *segs[2];
int nsegs;
caddr_t mapbase = MAP_FAILED;
size_t mapsize = 0;
size_t bsssize = 0;
int mapflags;
Elf_Off base_offset;
#ifdef MAP_ALIGNED
Elf_Addr base_alignment;
#endif
Elf_Addr base_vaddr;
Elf_Addr base_vlimit;
Elf_Addr text_vlimit;
int text_flags;
caddr_t base_addr;
Elf_Off data_offset;
Elf_Addr data_vaddr;
Elf_Addr data_vlimit;
int data_flags;
caddr_t data_addr;
Elf_Addr phdr_vaddr;
size_t phdr_memsz;
caddr_t gap_addr;
size_t gap_size;
int i;
#ifdef RTLD_LOADER
Elf_Addr clear_vaddr;
caddr_t clear_addr;
size_t nclear;
#endif
if (sb != NULL && sb->st_size < (off_t)sizeof (Elf_Ehdr)) {
_rtld_error("%s: unrecognized file format1", path);
return NULL;
}
obj = _rtld_obj_new();
obj->path = xstrdup(path);
obj->pathlen = strlen(path);
if (sb != NULL) {
obj->dev = sb->st_dev;
obj->ino = sb->st_ino;
}
ehdr = mmap(NULL, _rtld_pagesz, PROT_READ, MAP_FILE | MAP_SHARED, fd,
(off_t)0);
obj->ehdr = ehdr;
if (ehdr == MAP_FAILED) {
_rtld_error("%s: read error: %s", path, xstrerror(errno));
goto bad;
}
/* Make sure the file is valid */
if (memcmp(ELFMAG, ehdr->e_ident, SELFMAG) != 0 ||
ehdr->e_ident[EI_CLASS] != ELFCLASS) {
_rtld_error("%s: unrecognized file format2 [%x != %x]", path,
ehdr->e_ident[EI_CLASS], ELFCLASS);
goto bad;
}
/* Elf_e_ident includes class */
if (ehdr->e_ident[EI_VERSION] != EV_CURRENT ||
ehdr->e_version != EV_CURRENT ||
ehdr->e_ident[EI_DATA] != ELFDEFNNAME(MACHDEP_ENDIANNESS)) {
_rtld_error("%s: unsupported file version", path);
goto bad;
}
if (ehdr->e_type != ET_EXEC && ehdr->e_type != ET_DYN) {
_rtld_error("%s: unsupported file type", path);
goto bad;
}
switch (ehdr->e_machine) {
ELFDEFNNAME(MACHDEP_ID_CASES)
default:
_rtld_error("%s: unsupported machine", path);
goto bad;
}
/*
* We rely on the program header being in the first page. This is
* not strictly required by the ABI specification, but it seems to
* always true in practice. And, it simplifies things considerably.
*/
assert(ehdr->e_phentsize == sizeof(Elf_Phdr));
assert(ehdr->e_phoff + ehdr->e_phnum * sizeof(Elf_Phdr) <=
_rtld_pagesz);
/*
* Scan the program header entries, and save key information.
*
* We rely on there being exactly two load segments, text and data,
* in that order.
*/
phdr = (Elf_Phdr *) ((caddr_t)ehdr + ehdr->e_phoff);
phsize = ehdr->e_phnum * sizeof(phdr[0]);
obj->phdr = NULL;
phdr_vaddr = EA_UNDEF;
phdr_memsz = 0;
phlimit = phdr + ehdr->e_phnum;
nsegs = 0;
while (phdr < phlimit) {
switch (phdr->p_type) {
case PT_INTERP:
obj->interp = (void *)(uintptr_t)phdr->p_vaddr;
dbg(("%s: PT_INTERP %p", obj->path, obj->interp));
break;
case PT_LOAD:
if (nsegs < 2)
segs[nsegs] = phdr;
++nsegs;
dbg(("%s: PT_LOAD %p", obj->path, phdr));
break;
case PT_PHDR:
phdr_vaddr = phdr->p_vaddr;
phdr_memsz = phdr->p_memsz;
dbg(("%s: PT_PHDR %p phsize %zu", obj->path,
(void *)(uintptr_t)phdr_vaddr, phdr_memsz));
break;
case PT_DYNAMIC:
obj->dynamic = (void *)(uintptr_t)phdr->p_vaddr;
dbg(("%s: PT_DYNAMIC %p", obj->path, obj->dynamic));
break;
}
++phdr;
}
phdr = (Elf_Phdr *) ((caddr_t)ehdr + ehdr->e_phoff);
obj->entry = (void *)(uintptr_t)ehdr->e_entry;
if (!obj->dynamic) {
_rtld_error("%s: not dynamically linked", path);
goto bad;
}
if (nsegs != 2) {
_rtld_error("%s: wrong number of segments (%d != 2)", path,
nsegs);
goto bad;
}
/*
* Map the entire address space of the object as a file
* region to stake out our contiguous region and establish a
* base for relocation. We use a file mapping so that
* the kernel will give us whatever alignment is appropriate
* for the platform we're running on.
*
* We map it using the text protection, map the data segment
* into the right place, then map an anon segment for the bss
* and unmap the gaps left by padding to alignment.
*/
#ifdef MAP_ALIGNED
base_alignment = segs[0]->p_align;
#endif
base_offset = round_down(segs[0]->p_offset);
base_vaddr = round_down(segs[0]->p_vaddr);
base_vlimit = round_up(segs[1]->p_vaddr + segs[1]->p_memsz);
text_vlimit = round_up(segs[0]->p_vaddr + segs[0]->p_memsz);
text_flags = protflags(segs[0]->p_flags);
data_offset = round_down(segs[1]->p_offset);
data_vaddr = round_down(segs[1]->p_vaddr);
data_vlimit = round_up(segs[1]->p_vaddr + segs[1]->p_filesz);
data_flags = protflags(segs[1]->p_flags);
#ifdef RTLD_LOADER
clear_vaddr = segs[1]->p_vaddr + segs[1]->p_filesz;
#endif
obj->textsize = text_vlimit - base_vaddr;
obj->vaddrbase = base_vaddr;
obj->isdynamic = ehdr->e_type == ET_DYN;
obj->phdr_loaded = false;
for (i = 0; i < nsegs; i++) {
if (phdr_vaddr != EA_UNDEF &&
segs[i]->p_vaddr <= phdr_vaddr &&
segs[i]->p_memsz >= phdr_memsz) {
obj->phdr_loaded = true;
break;
}
if (segs[i]->p_offset <= ehdr->e_phoff &&
segs[i]->p_memsz >= phsize) {
phdr_vaddr = segs[i]->p_vaddr + ehdr->e_phoff;
phdr_memsz = phsize;
obj->phdr_loaded = true;
break;
}
}
if (obj->phdr_loaded) {
obj->phdr = (void *)(uintptr_t)phdr_vaddr;
obj->phsize = phdr_memsz;
} else {
Elf_Phdr *buf;
buf = xmalloc(phsize);
if (buf == NULL) {
_rtld_error("%s: cannot allocate program header", path);
goto bad;
}
memcpy(buf, phdr, phsize);
obj->phdr = buf;
obj->phsize = phsize;
}
dbg(("%s: phdr %p phsize %zu (%s)", obj->path, obj->phdr, obj->phsize,
obj->phdr_loaded ? "loaded" : "allocated"));
/* Unmap header if it overlaps the first load section. */
if (base_offset < _rtld_pagesz) {
munmap(ehdr, _rtld_pagesz);
obj->ehdr = MAP_FAILED;
}
/*
* Calculate log2 of the base section alignment.
*/
mapflags = 0;
#ifdef MAP_ALIGNED
if (base_alignment > _rtld_pagesz) {
unsigned int log2 = 0;
for (; base_alignment > 1; base_alignment >>= 1)
log2++;
mapflags = MAP_ALIGNED(log2);
}
int
_rtld_relocate_nonplt_objects(Obj_Entry *obj)
{
const Elf_Rel *rel;
for (rel = obj->rel; rel < obj->rellim; rel++) {
Elf_Addr *where;
const Elf_Sym *def;
const Obj_Entry *defobj;
Elf_Addr tmp;
unsigned long symnum;
where = (Elf_Addr *)(obj->relocbase + rel->r_offset);
symnum = ELF_R_SYM(rel->r_info);
switch (ELF_R_TYPE(rel->r_info)) {
case R_TYPE(NONE):
break;
#if 1 /* XXX should not occur */
case R_TYPE(PC24): { /* word32 S - P + A */
Elf32_Sword addend;
/*
* Extract addend and sign-extend if needed.
*/
addend = *where;
if (addend & 0x00800000)
addend |= 0xff000000;
def = _rtld_find_symdef(symnum, obj, &defobj, false);
if (def == NULL)
return -1;
tmp = (Elf_Addr)obj->relocbase + def->st_value
- (Elf_Addr)where + (addend << 2);
if ((tmp & 0xfe000000) != 0xfe000000 &&
(tmp & 0xfe000000) != 0) {
_rtld_error(
"%s: R_ARM_PC24 relocation @ %p to %s failed "
"(displacement %ld (%#lx) out of range)",
obj->path, where,
obj->strtab + obj->symtab[symnum].st_name,
(long) tmp, (long) tmp);
return -1;
}
tmp >>= 2;
*where = (*where & 0xff000000) | (tmp & 0x00ffffff);
rdbg(("PC24 %s in %s --> %p @ %p in %s",
obj->strtab + obj->symtab[symnum].st_name,
obj->path, (void *)*where, where, defobj->path));
break;
}
#endif
case R_TYPE(ABS32): /* word32 B + S + A */
case R_TYPE(GLOB_DAT): /* word32 B + S */
def = _rtld_find_symdef(symnum, obj, &defobj, false);
if (def == NULL)
return -1;
if (__predict_true(RELOC_ALIGNED_P(where))) {
tmp = *where + (Elf_Addr)defobj->relocbase +
def->st_value;
/* Set the Thumb bit, if needed. */
if (ELF_ST_TYPE(def->st_info) == STT_ARM_TFUNC)
tmp |= 1;
*where = tmp;
} else {
tmp = load_ptr(where) +
(Elf_Addr)defobj->relocbase +
def->st_value;
/* Set the Thumb bit, if needed. */
if (ELF_ST_TYPE(def->st_info) == STT_ARM_TFUNC)
tmp |= 1;
store_ptr(where, tmp);
}
rdbg(("ABS32/GLOB_DAT %s in %s --> %p @ %p in %s",
obj->strtab + obj->symtab[symnum].st_name,
obj->path, (void *)tmp, where, defobj->path));
break;
case R_TYPE(RELATIVE): /* word32 B + A */
if (__predict_true(RELOC_ALIGNED_P(where))) {
tmp = *where + (Elf_Addr)obj->relocbase;
*where = tmp;
} else {
tmp = load_ptr(where) +
(Elf_Addr)obj->relocbase;
store_ptr(where, tmp);
}
rdbg(("RELATIVE in %s --> %p", obj->path,
(void *)tmp));
break;
case R_TYPE(COPY):
/*
* These are deferred until all other relocations have
* been done. All we do here is make sure that the
* COPY relocation is not in a shared library. They
* are allowed only in executable files.
*/
if (obj->isdynamic) {
_rtld_error(
"%s: Unexpected R_COPY relocation in shared library",
obj->path);
return -1;
}
rdbg(("COPY (avoid in main)"));
break;
#if defined(__HAVE_TLS_VARIANT_I) || defined(__HAVE_TLS_VARIANT_II)
case R_TYPE(TLS_DTPOFF32):
def = _rtld_find_symdef(symnum, obj, &defobj, false);
if (def == NULL)
return -1;
tmp = (Elf_Addr)(def->st_value);
if (__predict_true(RELOC_ALIGNED_P(where)))
*where = tmp;
else
store_ptr(where, tmp);
rdbg(("TLS_DTPOFF32 %s in %s --> %p",
obj->strtab + obj->symtab[symnum].st_name,
obj->path, (void *)tmp));
break;
case R_TYPE(TLS_DTPMOD32):
def = _rtld_find_symdef(symnum, obj, &defobj, false);
if (def == NULL)
return -1;
tmp = (Elf_Addr)(defobj->tlsindex);
if (__predict_true(RELOC_ALIGNED_P(where)))
*where = tmp;
else
store_ptr(where, tmp);
rdbg(("TLS_DTPMOD32 %s in %s --> %p",
obj->strtab + obj->symtab[symnum].st_name,
obj->path, (void *)tmp));
break;
case R_TYPE(TLS_TPOFF32):
def = _rtld_find_symdef(symnum, obj, &defobj, false);
if (def == NULL)
return -1;
if (!defobj->tls_done &&
_rtld_tls_offset_allocate(obj))
return -1;
tmp = (Elf_Addr)def->st_value + defobj->tlsoffset +
sizeof(struct tls_tcb);
if (__predict_true(RELOC_ALIGNED_P(where)))
*where = tmp;
else
store_ptr(where, tmp);
rdbg(("TLS_TPOFF32 %s in %s --> %p",
obj->strtab + obj->symtab[symnum].st_name,
obj->path, (void *)tmp));
break;
#endif
default:
rdbg(("sym = %lu, type = %lu, offset = %p, "
"contents = %p, symbol = %s",
symnum, (u_long)ELF_R_TYPE(rel->r_info),
(void *)rel->r_offset, (void *)load_ptr(where),
obj->strtab + obj->symtab[symnum].st_name));
_rtld_error("%s: Unsupported relocation type %ld "
"in non-PLT relocations",
obj->path, (u_long) ELF_R_TYPE(rel->r_info));
return -1;
}
}
return 0;
}
int
reloc_non_plt(Obj_Entry *obj, Obj_Entry *obj_rtld, int flags,
RtldLockState *lockstate)
{
const Elf_Rel *rel;
const Elf_Rel *rellim;
Elf_Addr *got = obj->pltgot;
const Elf_Sym *sym, *def;
const Obj_Entry *defobj;
Elf_Word i;
#ifdef SUPPORT_OLD_BROKEN_LD
int broken;
#endif
/* The relocation for the dynamic loader has already been done. */
if (obj == obj_rtld)
return (0);
if ((flags & SYMLOOK_IFUNC) != 0)
/* XXX not implemented */
return (0);
#ifdef SUPPORT_OLD_BROKEN_LD
broken = 0;
sym = obj->symtab;
for (i = 1; i < 12; i++)
if (sym[i].st_info == ELF_ST_INFO(STB_LOCAL, STT_NOTYPE))
broken = 1;
dbg("%s: broken=%d", obj->path, broken);
#endif
i = (got[1] & GOT1_MASK) ? 2 : 1;
/* Relocate the local GOT entries */
got += i;
dbg("got:%p for %d entries adding %p",
got, obj->local_gotno, obj->relocbase);
for (; i < obj->local_gotno; i++) {
*got += (Elf_Addr)obj->relocbase;
got++;
}
sym = obj->symtab + obj->gotsym;
dbg("got:%p for %d entries",
got, obj->symtabno);
/* Now do the global GOT entries */
for (i = obj->gotsym; i < obj->symtabno; i++) {
dbg(" doing got %d sym %p (%s, %lx)", i - obj->gotsym, sym,
sym->st_name + obj->strtab, (u_long) *got);
#ifdef SUPPORT_OLD_BROKEN_LD
if (ELF_ST_TYPE(sym->st_info) == STT_FUNC &&
broken && sym->st_shndx == SHN_UNDEF) {
/*
* XXX DANGER WILL ROBINSON!
* You might think this is stupid, as it intentionally
* defeats lazy binding -- and you'd be right.
* Unfortunately, for lazy binding to work right, we
* need to a way to force the GOT slots used for
* function pointers to be resolved immediately. This
* is supposed to be done automatically by the linker,
* by not outputting a PLT slot and setting st_value
* to 0 if there are non-PLT references, but older
* versions of GNU ld do not do this.
*/
def = find_symdef(i, obj, &defobj, flags, NULL,
lockstate);
if (def == NULL)
return -1;
*got = def->st_value + (Elf_Addr)defobj->relocbase;
} else
#endif
if (ELF_ST_TYPE(sym->st_info) == STT_FUNC &&
sym->st_value != 0 && sym->st_shndx == SHN_UNDEF) {
/*
* If there are non-PLT references to the function,
* st_value should be 0, forcing us to resolve the
* address immediately.
*
* XXX DANGER WILL ROBINSON!
* The linker is not outputting PLT slots for calls to
* functions that are defined in the same shared
* library. This is a bug, because it can screw up
* link ordering rules if the symbol is defined in
* more than one module. For now, if there is a
* definition, we fail the test above and force a full
* symbol lookup. This means that all intra-module
* calls are bound immediately. - mycroft, 2003/09/24
*/
*got = sym->st_value + (Elf_Addr)obj->relocbase;
if ((Elf_Addr)(*got) == (Elf_Addr)obj->relocbase) {
dbg("Warning2, i:%d maps to relocbase address:%p",
i, obj->relocbase);
}
} else if (sym->st_info == ELF_ST_INFO(STB_GLOBAL, STT_SECTION)) {
/* Symbols with index SHN_ABS are not relocated. */
if (sym->st_shndx != SHN_ABS) {
*got = sym->st_value +
(Elf_Addr)obj->relocbase;
if ((Elf_Addr)(*got) == (Elf_Addr)obj->relocbase) {
dbg("Warning3, i:%d maps to relocbase address:%p",
i, obj->relocbase);
}
}
} else {
/* TODO: add cache here */
def = find_symdef(i, obj, &defobj, flags, NULL,
lockstate);
if (def == NULL) {
dbg("Warning4, can't find symbole %d", i);
return -1;
}
*got = def->st_value + (Elf_Addr)defobj->relocbase;
if ((Elf_Addr)(*got) == (Elf_Addr)obj->relocbase) {
dbg("Warning4, i:%d maps to relocbase address:%p",
i, obj->relocbase);
dbg("via first obj symbol %s",
obj->strtab + obj->symtab[i].st_name);
dbg("found in obj %p:%s",
defobj, defobj->path);
}
}
dbg(" --> now %lx", (u_long) *got);
++sym;
++got;
}
got = obj->pltgot;
rellim = (const Elf_Rel *)((caddr_t)obj->rel + obj->relsize);
for (rel = obj->rel; rel < rellim; rel++) {
Elf_Word r_symndx, r_type;
void *where;
where = obj->relocbase + rel->r_offset;
r_symndx = ELF_R_SYM(rel->r_info);
r_type = ELF_R_TYPE(rel->r_info);
switch (r_type & 0xff) {
case R_TYPE(NONE):
break;
case R_TYPE(REL32): {
/* 32-bit PC-relative reference */
const size_t rlen =
ELF_R_NXTTYPE_64_P(r_type)
? sizeof(Elf_Sxword)
: sizeof(Elf_Sword);
Elf_Sxword old = load_ptr(where, rlen);
Elf_Sxword val = old;
def = obj->symtab + r_symndx;
if (r_symndx >= obj->gotsym) {
val += got[obj->local_gotno + r_symndx - obj->gotsym];
dbg("REL32/G(%p) %p --> %p (%s) in %s",
where, (void *)old, (void *)val,
obj->strtab + def->st_name,
obj->path);
} else {
/*
* XXX: ABI DIFFERENCE!
*
* Old NetBSD binutils would generate shared
* libs with section-relative relocations being
* already adjusted for the start address of
* the section.
*
* New binutils, OTOH, generate shared libs
* with the same relocations being based at
* zero, so we need to add in the start address
* of the section.
*
* --rkb, Oct 6, 2001
*/
if (def->st_info ==
ELF_ST_INFO(STB_LOCAL, STT_SECTION)
#ifdef SUPPORT_OLD_BROKEN_LD
&& !broken
#endif
)
val += (Elf_Addr)def->st_value;
val += (Elf_Addr)obj->relocbase;
dbg("REL32/L(%p) %p -> %p (%s) in %s",
where, (void *)old, (void *)val,
obj->strtab + def->st_name, obj->path);
}
store_ptr(where, val, rlen);
break;
}
#ifdef __mips_n64
case R_TYPE(TLS_DTPMOD64):
#else
case R_TYPE(TLS_DTPMOD32):
#endif
{
const size_t rlen = sizeof(Elf_Addr);
Elf_Addr old = load_ptr(where, rlen);
Elf_Addr val = old;
def = find_symdef(r_symndx, obj, &defobj, flags, NULL,
lockstate);
if (def == NULL)
return -1;
val += (Elf_Addr)defobj->tlsindex;
store_ptr(where, val, rlen);
dbg("DTPMOD %s in %s %p --> %p in %s",
obj->strtab + obj->symtab[r_symndx].st_name,
obj->path, (void *)old, (void*)val, defobj->path);
break;
}
#ifdef __mips_n64
case R_TYPE(TLS_DTPREL64):
#else
case R_TYPE(TLS_DTPREL32):
#endif
{
const size_t rlen = sizeof(Elf_Addr);
Elf_Addr old = load_ptr(where, rlen);
Elf_Addr val = old;
def = find_symdef(r_symndx, obj, &defobj, flags, NULL,
lockstate);
if (def == NULL)
return -1;
if (!defobj->tls_done && allocate_tls_offset(obj))
return -1;
val += (Elf_Addr)def->st_value - TLS_DTP_OFFSET;
store_ptr(where, val, rlen);
dbg("DTPREL %s in %s %p --> %p in %s",
obj->strtab + obj->symtab[r_symndx].st_name,
obj->path, (void*)old, (void *)val, defobj->path);
break;
}
#ifdef __mips_n64
case R_TYPE(TLS_TPREL64):
#else
case R_TYPE(TLS_TPREL32):
#endif
{
const size_t rlen = sizeof(Elf_Addr);
Elf_Addr old = load_ptr(where, rlen);
Elf_Addr val = old;
def = find_symdef(r_symndx, obj, &defobj, flags, NULL,
lockstate);
if (def == NULL)
return -1;
if (!defobj->tls_done && allocate_tls_offset(obj))
return -1;
val += (Elf_Addr)(def->st_value + defobj->tlsoffset
- TLS_TP_OFFSET - TLS_TCB_SIZE);
store_ptr(where, val, rlen);
dbg("TPREL %s in %s %p --> %p in %s",
obj->strtab + obj->symtab[r_symndx].st_name,
obj->path, (void*)old, (void *)val, defobj->path);
break;
}
default:
dbg("sym = %lu, type = %lu, offset = %p, "
"contents = %p, symbol = %s",
(u_long)r_symndx, (u_long)ELF_R_TYPE(rel->r_info),
(void *)rel->r_offset,
(void *)load_ptr(where, sizeof(Elf_Sword)),
obj->strtab + obj->symtab[r_symndx].st_name);
_rtld_error("%s: Unsupported relocation type %ld "
"in non-PLT relocations",
obj->path, (u_long) ELF_R_TYPE(rel->r_info));
return -1;
}
}
return 0;
}
/* Relocate a non-PLT object with addend. */
static int
reloc_non_plt_obj(Obj_Entry *obj_rtld, Obj_Entry *obj, const Elf_Rela *rela,
SymCache *cache, int flags, RtldLockState *lockstate)
{
struct fptr **fptrs;
Elf_Addr *where = (Elf_Addr *) (obj->relocbase + rela->r_offset);
switch (ELF_R_TYPE(rela->r_info)) {
case R_IA_64_REL64LSB:
/*
* We handle rtld's relocations in rtld_start.S
*/
if (obj != obj_rtld)
store64(where,
load64(where) + (Elf_Addr) obj->relocbase);
break;
case R_IA_64_DIR64LSB: {
const Elf_Sym *def;
const Obj_Entry *defobj;
Elf_Addr target;
def = find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj,
flags, cache, lockstate);
if (def == NULL)
return -1;
target = (def->st_shndx != SHN_UNDEF)
? (Elf_Addr)(defobj->relocbase + def->st_value) : 0;
store64(where, target + rela->r_addend);
break;
}
case R_IA_64_FPTR64LSB: {
/*
* We have to make sure that all @fptr references to
* the same function are identical so that code can
* compare function pointers.
*/
const Elf_Sym *def;
const Obj_Entry *defobj;
struct fptr *fptr = 0;
Elf_Addr target, gp;
int sym_index;
def = find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj,
SYMLOOK_IN_PLT | flags, cache, lockstate);
if (def == NULL) {
/*
* XXX r_debug_state is problematic and find_symdef()
* returns NULL for it. This probably has something to
* do with symbol versioning (r_debug_state is in the
* symbol map). If we return -1 in that case we abort
* relocating rtld, which typically is fatal. So, for
* now just skip the symbol when we're relocating
* rtld. We don't care about r_debug_state unless we
* are being debugged.
*/
if (obj != obj_rtld)
return -1;
break;
}
if (def->st_shndx != SHN_UNDEF) {
target = (Elf_Addr)(defobj->relocbase + def->st_value);
gp = (Elf_Addr)defobj->pltgot;
/* rtld is allowed to reference itself only */
assert(!obj->rtld || obj == defobj);
fptrs = defobj->priv;
if (fptrs == NULL)
fptrs = alloc_fptrs((Obj_Entry *) defobj,
obj->rtld);
sym_index = def - defobj->symtab;
/*
* Find the @fptr, using fptrs as a helper.
*/
if (fptrs)
fptr = fptrs[sym_index];
if (!fptr) {
fptr = alloc_fptr(target, gp);
if (fptrs)
fptrs[sym_index] = fptr;
}
} else
fptr = NULL;
store64(where, (Elf_Addr)fptr);
break;
}
case R_IA_64_IPLTLSB: {
/*
* Relocation typically used to populate C++ virtual function
* tables. It creates a 128-bit function descriptor at the
* specified memory address.
*/
const Elf_Sym *def;
const Obj_Entry *defobj;
struct fptr *fptr;
Elf_Addr target, gp;
def = find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj,
flags, cache, lockstate);
if (def == NULL)
return -1;
if (def->st_shndx != SHN_UNDEF) {
target = (Elf_Addr)(defobj->relocbase + def->st_value);
gp = (Elf_Addr)defobj->pltgot;
} else {
target = 0;
gp = 0;
}
fptr = (void*)where;
store64(&fptr->target, target);
store64(&fptr->gp, gp);
break;
}
case R_IA_64_DTPMOD64LSB: {
const Elf_Sym *def;
const Obj_Entry *defobj;
def = find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj,
flags, cache, lockstate);
if (def == NULL)
return -1;
store64(where, defobj->tlsindex);
break;
}
case R_IA_64_DTPREL64LSB: {
const Elf_Sym *def;
const Obj_Entry *defobj;
def = find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj,
flags, cache, lockstate);
if (def == NULL)
return -1;
store64(where, def->st_value + rela->r_addend);
break;
}
case R_IA_64_TPREL64LSB: {
const Elf_Sym *def;
const Obj_Entry *defobj;
def = find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj,
flags, cache, lockstate);
if (def == NULL)
return -1;
/*
* We lazily allocate offsets for static TLS as we
* see the first relocation that references the
* TLS block. This allows us to support (small
* amounts of) static TLS in dynamically loaded
* modules. If we run out of space, we generate an
* error.
*/
if (!defobj->tls_done) {
if (!allocate_tls_offset((Obj_Entry*) defobj)) {
_rtld_error("%s: No space available for static "
"Thread Local Storage", obj->path);
return -1;
}
}
store64(where, defobj->tlsoffset + def->st_value + rela->r_addend);
break;
}
case R_IA_64_NONE:
break;
default:
_rtld_error("%s: Unsupported relocation type %u"
" in non-PLT relocations\n", obj->path,
(unsigned int)ELF_R_TYPE(rela->r_info));
return -1;
}
return(0);
}
/*
* Map a shared object into memory. The "fd" argument is a file descriptor,
* which must be open on the object and positioned at its beginning.
* The "path" argument is a pathname that is used only for error messages.
*
* The return value is a pointer to a newly-allocated Obj_Entry structure
* for the shared object. Returns NULL on failure.
*/
Obj_Entry *
map_object(const char *path, char *buf, ssize_t size)
{
Obj_Entry *obj;
Elf_Ehdr *hdr;
int i;
Elf_Phdr *phdr;
Elf_Phdr *phlimit;
Elf_Phdr **segs;
int nsegs;
Elf_Phdr *phdyn;
Elf_Phdr *phinterp;
Elf_Phdr *phtls;
caddr_t mapbase;
size_t mapsize;
Elf_Off base_offset;
Elf_Addr base_vaddr;
Elf_Addr base_vlimit;
caddr_t base_addr;
Elf_Off data_offset;
Elf_Addr data_vaddr;
Elf_Addr data_vlimit;
caddr_t data_addr;
int data_prot;
int data_flags;
Elf_Addr clear_vaddr;
caddr_t clear_addr;
caddr_t clear_page;
Elf_Addr phdr_vaddr;
size_t nclear, phsize;
Elf_Addr bss_vaddr;
Elf_Addr bss_vlimit;
caddr_t bss_addr;
hdr = get_elf_header(path, buf, size);
if (hdr == NULL)
return (NULL);
/*
* Scan the program header entries, and save key information.
*
* We expect that the loadable segments are ordered by load address.
*/
phdr = (Elf_Phdr *) ((char *)hdr + hdr->e_phoff);
phsize = hdr->e_phnum * sizeof (phdr[0]);
phlimit = phdr + hdr->e_phnum;
nsegs = -1;
phdyn = phinterp = phtls = NULL;
phdr_vaddr = 0;
segs = alloca(sizeof(segs[0]) * hdr->e_phnum);
while (phdr < phlimit) {
switch (phdr->p_type) {
case PT_INTERP:
phinterp = phdr;
break;
case PT_LOAD:
segs[++nsegs] = phdr;
if ((segs[nsegs]->p_align & (PAGE_SIZE - 1)) != 0) {
_rtld_error("%s: PT_LOAD segment %d not page-aligned",
path, nsegs);
return NULL;
}
break;
case PT_PHDR:
phdr_vaddr = phdr->p_vaddr;
phsize = phdr->p_memsz;
break;
case PT_DYNAMIC:
phdyn = phdr;
break;
case PT_TLS:
phtls = phdr;
break;
}
++phdr;
}
if (phdyn == NULL) {
_rtld_error("%s: object is not dynamically-linked", path);
return NULL;
}
if (nsegs < 0) {
_rtld_error("%s: too few PT_LOAD segments", path);
return NULL;
}
/*
* Map the entire address space of the object, to stake out our
* contiguous region, and to establish the base address for relocation.
*/
base_offset = trunc_page(segs[0]->p_offset);
base_vaddr = trunc_page(segs[0]->p_vaddr);
base_vlimit = round_page(segs[nsegs]->p_vaddr + segs[nsegs]->p_memsz);
mapsize = base_vlimit - base_vaddr;
base_addr = hdr->e_type == ET_EXEC ? (caddr_t) base_vaddr : NULL;
mapbase = mmap(base_addr, mapsize, PROT_NONE, MAP_ANON | MAP_PRIVATE |
MAP_NOCORE, -1, 0);
if (mapbase == (caddr_t) -1) {
_rtld_error("%s: mmap of entire address space failed: %s",
path, strerror(errno));
return NULL;
}
if (base_addr != NULL && mapbase != base_addr) {
_rtld_error("%s: mmap returned wrong address: wanted %p, got %p",
path, base_addr, mapbase);
munmap(mapbase, mapsize);
return NULL;
}
for (i = 0; i <= nsegs; i++) {
size_t data_vsize;
/* Overlay the segment onto the proper region. */
data_offset = trunc_page(segs[i]->p_offset);
data_vaddr = trunc_page(segs[i]->p_vaddr);
data_vlimit = round_page(segs[i]->p_vaddr + segs[i]->p_filesz);
data_addr = mapbase + (data_vaddr - base_vaddr);
data_prot = convert_prot(segs[i]->p_flags) | PROT_WRITE;
data_vsize = data_vlimit - data_vaddr;
data_flags = convert_flags(segs[i]->p_flags) | \
MAP_FIXED | MAP_ANON | MAP_PRIVATE;
if (mmap(data_addr, data_vsize, data_prot, data_flags,
-1, data_offset) == (caddr_t) -1) {
_rtld_error("%s: mmap of data failed: %s", path, strerror(errno));
return NULL;
}
bcopy(buf + data_offset, data_addr, MIN(data_vsize, (size - data_offset)));
/* Do BSS setup */
if (segs[i]->p_filesz != segs[i]->p_memsz) {
/* Clear any BSS in the last page of the segment. */
clear_vaddr = segs[i]->p_vaddr + segs[i]->p_filesz;
clear_addr = mapbase + (clear_vaddr - base_vaddr);
clear_page = mapbase + (trunc_page(clear_vaddr) - base_vaddr);
if ((nclear = data_vlimit - clear_vaddr) > 0) {
/* Make sure the end of the segment is writable */
if ((data_prot & PROT_WRITE) == 0 && -1 ==
mprotect(clear_page, PAGE_SIZE, data_prot|PROT_WRITE)) {
_rtld_error("%s: mprotect failed: %s", path,
strerror(errno));
return NULL;
}
memset(clear_addr, 0, nclear);
/* Reset the data protection back */
if ((data_prot & PROT_WRITE) == 0)
mprotect(clear_page, PAGE_SIZE, data_prot);
}
/* Overlay the BSS segment onto the proper region. */
bss_vaddr = data_vlimit;
bss_vlimit = round_page(segs[i]->p_vaddr + segs[i]->p_memsz);
bss_addr = mapbase + (bss_vaddr - base_vaddr);
if (bss_vlimit > bss_vaddr) { /* There is something to do */
if (mprotect(bss_addr, bss_vlimit - bss_vaddr, data_prot) == -1) {
_rtld_error("%s: mprotect of bss failed: %s", path,
strerror(errno));
return NULL;
}
}
}
if (phdr_vaddr == 0 && data_offset <= hdr->e_phoff &&
(data_vlimit - data_vaddr + data_offset) >=
(hdr->e_phoff + hdr->e_phnum * sizeof (Elf_Phdr))) {
phdr_vaddr = data_vaddr + hdr->e_phoff - data_offset;
}
}
obj = obj_new();
obj->mapbase = mapbase;
obj->mapsize = mapsize;
obj->textsize = round_page(segs[0]->p_vaddr + segs[0]->p_memsz) -
base_vaddr;
obj->vaddrbase = base_vaddr;
obj->relocbase = mapbase - base_vaddr;
obj->dynamic = (const Elf_Dyn *) (obj->relocbase + phdyn->p_vaddr);
if (hdr->e_entry != 0)
obj->entry = (caddr_t) (obj->relocbase + hdr->e_entry);
if (phdr_vaddr != 0) {
obj->phdr = (const Elf_Phdr *) (obj->relocbase + phdr_vaddr);
} else {
obj->phdr = malloc(phsize);
if (obj->phdr == NULL) {
obj_free(obj);
_rtld_error("%s: cannot allocate program header", path);
return NULL;
}
memcpy((char *)obj->phdr, (char *)hdr + hdr->e_phoff, phsize);
obj->phdr_alloc = true;
}
obj->phsize = phsize;
if (phinterp != NULL)
obj->interp = (const char *) (obj->relocbase + phinterp->p_vaddr);
if (phtls != NULL) {
tls_dtv_generation++;
obj->tlsindex = ++tls_max_index;
obj->tlssize = phtls->p_memsz;
obj->tlsalign = phtls->p_align;
obj->tlsinitsize = phtls->p_filesz;
obj->tlsinit = mapbase + phtls->p_vaddr;
}
return obj;
}
/* Process the non-PLT relocations. */
int
reloc_non_plt(Obj_Entry *obj)
{
const Elf_Rel *rellim;
const Elf_Rel *rel;
rellim = (const Elf_Rel *) ((caddr_t) obj->rel + obj->relsize);
for (rel = obj->rel; rel < rellim; rel++) {
Elf_Addr *where = (Elf_Addr *) (obj->relocbase + rel->r_offset);
switch (ELF_R_TYPE(rel->r_info)) {
case R_386_NONE:
break;
case R_386_32:
{
const Elf_Sym *def;
const Obj_Entry *defobj;
def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj,
false);
if (def == NULL)
return -1;
*where += (Elf_Addr) (defobj->relocbase + def->st_value);
}
break;
case R_386_PC32:
/*
* I don't think the dynamic linker should ever see this
* type of relocation. But the binutils-2.6 tools sometimes
* generate it.
*/
{
const Elf_Sym *def;
const Obj_Entry *defobj;
def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj,
false);
if (def == NULL)
return -1;
*where +=
(Elf_Addr) (defobj->relocbase + def->st_value) -
(Elf_Addr) where;
}
break;
case R_386_COPY:
/*
* These are deferred until all other relocations have
* been done. All we do here is make sure that the COPY
* relocation is not in a shared library. They are allowed
* only in executable files.
*/
if (!obj->mainprog) {
_rtld_error("%s: Unexpected R_386_COPY relocation"
" in shared library", obj->path);
return -1;
}
break;
case R_386_GLOB_DAT:
{
const Elf_Sym *def;
const Obj_Entry *defobj;
def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj,
false);
if (def == NULL)
return -1;
*where = (Elf_Addr) (defobj->relocbase + def->st_value);
}
break;
case R_386_RELATIVE:
*where += (Elf_Addr) obj->relocbase;
break;
default:
_rtld_error("%s: Unsupported relocation type %d"
" in non-PLT relocations\n", obj->path,
ELF_R_TYPE(rel->r_info));
return -1;
}
}
return 0;
}