mirror/glibc
2
0
Fork 0
mirror of git://sourceware.org/git/glibc.git synced 2024-12-15 04:20:28 +08:00
Code Issues Packages Projects Releases Wiki Activity
50449bed17
glibc/sysdeps/mips/dl-machine.h
Alexandre Oliva 50449bed17 * sysdeps/mips/dl-machine.h (ELF_MIPS_GNU_GOT1_MASK): Define properly for n64. (elf_machine_runtime_setup): Cast link_map pointer to Elf Addr type. (elf_machine_rel, elf_machine_rel_relative): Cast symidx to Elf Word before comparing with gotsym. Take reloc_addr argument as void*. Remove the code added for the compiler to drop any alignment assumptions. 
2003-03-20  Alexandre Oliva  <aoliva@redhat.com>

	* sysdeps/mips/dl-machine.h (ELF_MIPS_GNU_GOT1_MASK): Define
	properly for n64.
	(elf_machine_runtime_setup): Cast link_map pointer to Elf Addr
	type.
	(elf_machine_rel, elf_machine_rel_relative): Cast symidx to Elf
	Word before comparing with gotsym.  Take reloc_addr argument as
	void*.  Remove the code added for the compiler to drop any
	alignment assumptions.
2003-03-20 07:54:21 +00:00

781 lines
25 KiB
C
Raw Blame History

/* Machine-dependent ELF dynamic relocation inline functions. MIPS version.
Copyright (C) 1996-2001, 2002, 2003 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Kazumoto Kojima <kkojima@info.kanagawa-u.ac.jp>.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
/* FIXME: Profiling of shared libraries is not implemented yet. */
#ifndef dl_machine_h
#define dl_machine_h
#define ELF_MACHINE_NAME "MIPS"
#define ELF_MACHINE_NO_PLT
#include <entry.h>
#ifndef ENTRY_POINT
#error ENTRY_POINT needs to be defined for MIPS.
#endif
#include <sys/asm.h>
/* The offset of gp from GOT might be system-dependent. It's set by
ld. The same value is also */
#define OFFSET_GP_GOT 0x7ff0
#ifndef _RTLD_PROLOGUE
# define _RTLD_PROLOGUE(entry) \
".globl\t" __STRING(entry) "\n\t" \
".ent\t" __STRING(entry) "\n\t" \
".type\t" __STRING(entry) ", @function\n" \
__STRING(entry) ":\n\t"
#endif
#ifndef _RTLD_EPILOGUE
# define _RTLD_EPILOGUE(entry) \
".end\t" __STRING(entry) "\n\t" \
".size\t" __STRING(entry) ", . - " __STRING(entry) "\n\t"
#endif
/* A reloc type used for ld.so cmdline arg lookups to reject PLT entries.
This makes no sense on MIPS but we have to define this to R_MIPS_REL32
to avoid the asserts in dl-lookup.c from blowing. */
#define ELF_MACHINE_JMP_SLOT R_MIPS_REL32
#define elf_machine_type_class(type) ELF_RTYPE_CLASS_PLT
/* Translate a processor specific dynamic tag to the index
in l_info array. */
#define DT_MIPS(x) (DT_MIPS_##x - DT_LOPROC + DT_NUM)
/* If there is a DT_MIPS_RLD_MAP entry in the dynamic section, fill it in
with the run-time address of the r_debug structure */
#define ELF_MACHINE_DEBUG_SETUP(l,r) \
do { if ((l)->l_info[DT_MIPS (RLD_MAP)]) \
*(ElfW(Addr) *)((l)->l_info[DT_MIPS (RLD_MAP)]->d_un.d_ptr) = \
(ElfW(Addr)) (r); \
} while (0)
/* Return nonzero iff ELF header is compatible with the running host. */
static inline int __attribute_used__
elf_machine_matches_host (const ElfW(Ehdr) *ehdr)
{
#if _MIPS_SIM == _MIPS_SIM_ABI32 || _MIPS_SIM == _MIPS_SIM_NABI32
/* Don't link o32 and n32 together. */
if (((ehdr->e_flags & EF_MIPS_ABI2) != 0)
!= (_MIPS_SIM != _MIPS_SIM_ABI32))
return 0;
#endif
switch (ehdr->e_machine)
{
case EM_MIPS:
case EM_MIPS_RS3_LE:
return 1;
default:
return 0;
}
}
static inline ElfW(Addr) *
elf_mips_got_from_gpreg (ElfW(Addr) gpreg)
{
/* FIXME: the offset of gp from GOT may be system-dependent. */
return (ElfW(Addr) *) (gpreg - OFFSET_GP_GOT);
}
/* Return the link-time address of _DYNAMIC. Conveniently, this is the
first element of the GOT. This must be inlined in a function which
uses global data. We assume its $gp points to the primary GOT. */
static inline ElfW(Addr)
elf_machine_dynamic (void)
{
register ElfW(Addr) gp __asm__ ("$28");
return *elf_mips_got_from_gpreg (gp);
}
#define STRINGXP(X) __STRING(X)
#define STRINGXV(X) STRINGV_(X)
#define STRINGV_(...) # __VA_ARGS__
/* Return the run-time load address of the shared object. */
static inline ElfW(Addr)
elf_machine_load_address (void)
{
ElfW(Addr) addr;
asm (" .set noreorder\n"
" " STRINGXP (PTR_LA) " %0, 0f\n"
" bltzal $0, 0f\n"
" nop\n"
"0: " STRINGXP (PTR_SUBU) " %0, $31, %0\n"
" .set reorder\n"
: "=r" (addr)
: /* No inputs */
: "$31");
return addr;
}
/* The MSB of got[1] of a gnu object is set to identify gnu objects. */
#ifdef _ABI64 && _MIPS_SIM == _ABI64
# define ELF_MIPS_GNU_GOT1_MASK 0x8000000000000000L
#else
# define ELF_MIPS_GNU_GOT1_MASK 0x80000000L
#endif
/* We can't rely on elf_machine_got_rel because _dl_object_relocation_scope
fiddles with global data. */
#define ELF_MACHINE_BEFORE_RTLD_RELOC(dynamic_info) \
do { \
struct link_map *map = &bootstrap_map; \
ElfW(Sym) *sym; \
ElfW(Addr) *got; \
int i, n; \
\
got = (ElfW(Addr) *) D_PTR (map, l_info[DT_PLTGOT]); \
\
if (__builtin_expect (map->l_addr == 0, 1)) \
break; \
\
/* got[0] is reserved. got[1] is also reserved for the dynamic object \
generated by gnu ld. Skip these reserved entries from \
relocation. */ \
i = (got[1] & ELF_MIPS_GNU_GOT1_MASK)? 2 : 1; \
n = map->l_info[DT_MIPS (LOCAL_GOTNO)]->d_un.d_val; \
\
/* Add the run-time displacement to all local got entries. */ \
while (i < n) \
got[i++] += map->l_addr; \
\
/* Handle global got entries. */ \
got += n; \
sym = (ElfW(Sym) *) D_PTR(map, l_info[DT_SYMTAB]) \
+ map->l_info[DT_MIPS (GOTSYM)]->d_un.d_val; \
i = (map->l_info[DT_MIPS (SYMTABNO)]->d_un.d_val \
- map->l_info[DT_MIPS (GOTSYM)]->d_un.d_val); \
\
while (i--) \
{ \
if (sym->st_shndx == SHN_UNDEF || sym->st_shndx == SHN_COMMON) \
*got = map->l_addr + sym->st_value; \
else if (ELFW(ST_TYPE) (sym->st_info) == STT_FUNC \
&& *got != sym->st_value) \
*got += map->l_addr; \
else if (ELFW(ST_TYPE) (sym->st_info) == STT_SECTION) \
{ \
if (sym->st_other == 0) \
*got += map->l_addr; \
} \
else \
*got = map->l_addr + sym->st_value; \
\
got++; \
sym++; \
} \
} while(0)
/* Get link map for callers object containing STUB_PC. */
static inline struct link_map *
elf_machine_runtime_link_map (ElfW(Addr) gpreg, ElfW(Addr) stub_pc)
{
extern int _dl_mips_gnu_objects;
/* got[1] is reserved to keep its link map address for the shared
object generated by the gnu linker. If all are such objects, we
can find the link map from current GPREG simply. If not so, get
the link map for caller's object containing STUB_PC. */
if (_dl_mips_gnu_objects)
{
ElfW(Addr) *got = elf_mips_got_from_gpreg (gpreg);
ElfW(Word) g1;
g1 = ((ElfW(Word) *) got)[1];
if ((g1 & ELF_MIPS_GNU_GOT1_MASK) != 0)
{
struct link_map *l =
(struct link_map *) (g1 & ~ELF_MIPS_GNU_GOT1_MASK);
ElfW(Addr) base, limit;
const ElfW(Phdr) *p = l->l_phdr;
ElfW(Half) this, nent = l->l_phnum;
/* For the common case of a stub being called from the containing
object, STUB_PC will point to somewhere within the object that
is described by the link map fetched via got[1]. Otherwise we
have to scan all maps. */
for (this = 0; this < nent; this++)
{
if (p[this].p_type == PT_LOAD)
{
base = p[this].p_vaddr + l->l_addr;
limit = base + p[this].p_memsz;
if (stub_pc >= base && stub_pc < limit)
return l;
}
}
}
}
{
struct link_map *l = GL(dl_loaded);
while (l)
{
ElfW(Addr) base, limit;
const ElfW(Phdr) *p = l->l_phdr;
ElfW(Half) this, nent = l->l_phnum;
for (this = 0; this < nent; ++this)
{
if (p[this].p_type == PT_LOAD)
{
base = p[this].p_vaddr + l->l_addr;
limit = base + p[this].p_memsz;
if (stub_pc >= base && stub_pc < limit)
return l;
}
}
l = l->l_next;
}
}
INTUSE (_dl_signal_error) (0, NULL, NULL, "cannot find runtime link map");
return NULL;
}
#if _MIPS_SIM == _MIPS_SIM_ABI32
#define ELF_DL_FRAME_SIZE 40
#define ELF_DL_SAVE_ARG_REGS "\
sw $15, 36($29)\n \
sw $4, 16($29)\n \
sw $5, 20($29)\n \
sw $6, 24($29)\n \
sw $7, 28($29)\n \
"
#define ELF_DL_RESTORE_ARG_REGS "\
lw $31, 36($29)\n \
lw $4, 16($29)\n \
lw $5, 20($29)\n \
lw $6, 24($29)\n \
lw $7, 28($29)\n \
"
#define IFABIO32(X) X
#else /* _MIPS_SIM == _MIPS_SIM_NABI32 || _MIPS_SIM == _MIPS_SIM_ABI64 */
#define ELF_DL_FRAME_SIZE 64
#define ELF_DL_SAVE_ARG_REGS "\
sd $15, 56($29)\n \
sd $4, 8($29)\n \
sd $5, 16($29)\n \
sd $6, 24($29)\n \
sd $7, 32($29)\n \
sd $8, 40($29)\n \
sd $9, 48($29)\n \
"
#define ELF_DL_RESTORE_ARG_REGS "\
ld $31, 56($29)\n \
ld $4, 8($29)\n \
ld $5, 16($29)\n \
ld $6, 24($29)\n \
ld $7, 32($29)\n \
ld $8, 40($29)\n \
ld $9, 48($29)\n \
"
#define IFABIO32(X)
#endif
/* Define mips specific runtime resolver. The function __dl_runtime_resolve
is called from assembler function _dl_runtime_resolve which converts
special argument registers t7 ($15) and t8 ($24):
t7 address to return to the caller of the function
t8 index for this function symbol in .dynsym
to usual c arguments.
Other architectures call fixup from dl-runtime.c in
_dl_runtime_resolve. MIPS instead calls __dl_runtime_resolve. We
have to use our own version because of the way the got section is
treated on MIPS (we've also got ELF_MACHINE_PLT defined). */
#define ELF_MACHINE_RUNTIME_TRAMPOLINE \
/* The flag _dl_mips_gnu_objects is set if all dynamic objects are \
generated by the gnu linker. */ \
int _dl_mips_gnu_objects = 1; \
\
/* This is called from assembly stubs below which the compiler can't see. */ \
static ElfW(Addr) \
__dl_runtime_resolve (ElfW(Word), ElfW(Word), ElfW(Addr), ElfW(Addr)) \
__attribute_used__; \
\
static ElfW(Addr) \
__dl_runtime_resolve (ElfW(Word) sym_index, \
ElfW(Word) return_address, \
ElfW(Addr) old_gpreg, \
ElfW(Addr) stub_pc) \
{ \
struct link_map *l = elf_machine_runtime_link_map (old_gpreg, stub_pc); \
const ElfW(Sym) *const symtab \
= (const ElfW(Sym) *) D_PTR (l, l_info[DT_SYMTAB]); \
const char *strtab = (const void *) D_PTR (l, l_info[DT_STRTAB]); \
ElfW(Addr) *got \
= (ElfW(Addr) *) D_PTR (l, l_info[DT_PLTGOT]); \
const ElfW(Word) local_gotno \
= (const ElfW(Word)) l->l_info[DT_MIPS (LOCAL_GOTNO)]->d_un.d_val; \
const ElfW(Word) gotsym \
= (const ElfW(Word)) l->l_info[DT_MIPS (GOTSYM)]->d_un.d_val; \
const ElfW(Sym) *sym = &symtab[sym_index]; \
ElfW(Addr) value; \
\
/* FIXME: The symbol versioning stuff is not tested yet. */ \
if (__builtin_expect (ELFW(ST_VISIBILITY) (sym->st_other), 0) == 0) \
{ \
switch (l->l_info[VERSYMIDX (DT_VERSYM)] != NULL) \
{ \
default: \
{ \
const ElfW(Half) *vernum = \
(const void *) D_PTR (l, l_info[VERSYMIDX (DT_VERSYM)]); \
ElfW(Half) ndx = vernum[sym_index] & 0x7fff; \
const struct r_found_version *version = &l->l_versions[ndx]; \
\
if (version->hash != 0) \
{ \
value = _dl_lookup_versioned_symbol(strtab + sym->st_name, l, \
&sym, l->l_scope, version,\
ELF_RTYPE_CLASS_PLT, 0); \
break; \
} \
/* Fall through. */ \
} \
case 0: \
value = _dl_lookup_symbol (strtab + sym->st_name, l, &sym, \
l->l_scope, ELF_RTYPE_CLASS_PLT, \
DL_LOOKUP_ADD_DEPENDENCY); \
} \
\
/* Currently value contains the base load address of the object \
that defines sym. Now add in the symbol offset. */ \
value = (sym ? value + sym->st_value : 0); \
} \
else \
/* We already found the symbol. The module (and therefore its load \
address) is also known. */ \
value = l->l_addr + sym->st_value; \
\
/* Apply the relocation with that value. */ \
*(got + local_gotno + sym_index - gotsym) = value; \
\
return value; \
} \
\
asm ("\n \
.text\n \
.align 2\n \
.globl _dl_runtime_resolve\n \
.type _dl_runtime_resolve,@function\n \
.ent _dl_runtime_resolve\n \
_dl_runtime_resolve:\n \
.frame $29, " STRINGXP(ELF_DL_FRAME_SIZE) ", $31\n \
.set noreorder\n \
# Save GP.\n \
move $3, $28\n \
# Save arguments and sp value in stack.\n \
" STRINGXP(PTR_SUBIU) " $29, " STRINGXP(ELF_DL_FRAME_SIZE) "\n \
# Modify t9 ($25) so as to point .cpload instruction.\n \
" IFABIO32(STRINGXP(PTR_ADDIU) " $25, 12\n") " \
# Compute GP.\n \
" STRINGXP(SETUP_GP) "\n \
" STRINGXV(SETUP_GP64 (0, _dl_runtime_resolve)) "\n \
.set reorder\n \
# Save slot call pc.\n \
move $2, $31\n \
" IFABIO32(STRINGXP(CPRESTORE(32))) "\n \
" ELF_DL_SAVE_ARG_REGS " \
move $4, $24\n \
move $5, $15\n \
move $6, $3\n \
move $7, $2\n \
jal __dl_runtime_resolve\n \
" ELF_DL_RESTORE_ARG_REGS " \
" STRINGXP(RESTORE_GP64) "\n \
" STRINGXP(PTR_ADDIU) " $29, " STRINGXP(ELF_DL_FRAME_SIZE) "\n \
move $25, $2\n \
jr $25\n \
.end _dl_runtime_resolve\n \
.previous\n \
");
/* Mask identifying addresses reserved for the user program,
where the dynamic linker should not map anything. */
#define ELF_MACHINE_USER_ADDRESS_MASK 0x80000000UL
/* Initial entry point code for the dynamic linker.
The C function `_dl_start' is the real entry point;
its return value is the user program's entry point.
Note how we have to be careful about two things:
1) That we allocate a minimal stack of 24 bytes for
every function call, the MIPS ABI states that even
if all arguments are passed in registers the procedure
called can use the 16 byte area pointed to by $sp
when it is called to store away the arguments passed
to it.
2) That under Linux the entry is named __start
and not just plain _start. */
#define RTLD_START asm (\
".text\n"\
_RTLD_PROLOGUE(ENTRY_POINT) "\
" STRINGXV(SETUP_GPX($25)) "\n\
" STRINGXV(SETUP_GPX64($18,$25)) "\n\
# i386 ABI book says that the first entry of GOT holds\n\
# the address of the dynamic structure. Though MIPS ABI\n\
# doesn't say nothing about this, I emulate this here.\n\
" STRINGXP(PTR_LA) " $4, _DYNAMIC\n\
# Subtract OFFSET_GP_GOT\n\
" STRINGXP(PTR_S) " $4, -0x7ff0($28)\n\
move $4, $29\n\
" STRINGXP(PTR_SUBIU) " $29, 16\n\
\n\
" STRINGXP(PTR_LA) " $8, .Lcoff\n\
bltzal $8, .Lcoff\n\
.Lcoff: " STRINGXP(PTR_SUBU) " $8, $31, $8\n\
\n\
" STRINGXP(PTR_LA) " $25, _dl_start\n\
" STRINGXP(PTR_ADDU) " $25, $8\n\
jalr $25\n\
\n\
" STRINGXP(PTR_ADDIU) " $29, 16\n\
# Get the value of label '_dl_start_user' in t9 ($25).\n\
" STRINGXP(PTR_LA) " $25, _dl_start_user\n\
.globl _dl_start_user\n\
.type _dl_start_user,@function\n\
.ent _dl_start_user\n\
_dl_start_user:\n\
" STRINGXP(SETUP_GP) "\n\
" STRINGXV(SETUP_GP64($18,_dl_start_user)) "\n\
move $16, $28\n\
# Save the user entry point address in a saved register.\n\
move $17, $2\n\
# Store the highest stack address\n\
" STRINGXP(PTR_S) " $29, __libc_stack_end\n\
# See if we were run as a command with the executable file\n\
# name as an extra leading argument.\n\
lw $2, _dl_skip_args\n\
beq $2, $0, 1f\n\
# Load the original argument count.\n\
" STRINGXP(PTR_L) " $4, 0($29)\n\
# Subtract _dl_skip_args from it.\n\
subu $4, $2\n\
# Adjust the stack pointer to skip _dl_skip_args words.\n\
sll $2, " STRINGXP (PTRLOG) "\n\
" STRINGXP(PTR_ADDU) " $29, $2\n\
# Save back the modified argument count.\n\
" STRINGXP(PTR_S) " $4, 0($29)\n\
1: # Call _dl_init (struct link_map *main_map, int argc, char **argv, char **env) \n\
" STRINGXP(PTR_L) " $4, _rtld_local\n\
" STRINGXP(PTR_L) /* or lw??? fixme */ " $5, 0($29)\n\
" STRINGXP(PTR_LA) " $6, " STRINGXP (PTRSIZE) "($29)\n\
sll $7, $5, " STRINGXP (PTRLOG) "\n\
" STRINGXP(PTR_ADDU) " $7, $7, $6\n\
" STRINGXP(PTR_ADDU) " $7, $7, " STRINGXP (PTRSIZE) " \n\
" STRINGXP(PTR_SUBIU) " $29, 32\n\
" STRINGXP(SAVE_GP(16)) "\n\
# Call the function to run the initializers.\n\
jal _dl_init_internal\n\
" STRINGXP(PTR_ADDIU) " $29, 32\n\
# Pass our finalizer function to the user in $2 as per ELF ABI.\n\
" STRINGXP(PTR_LA) " $2, _dl_fini\n\
# Jump to the user entry point.\n\
move $25, $17\n\
jr $25\n\
.end _dl_start_user\n\t"\
_RTLD_EPILOGUE(ENTRY_POINT)\
".previous"\
);
/* The MIPS never uses Elfxx_Rela relocations. */
#define ELF_MACHINE_NO_RELA 1
#endif /* !dl_machine_h */
#ifdef RESOLVE
/* Perform the relocation specified by RELOC and SYM (which is fully resolved).
MAP is the object containing the reloc. */
static inline void
#ifdef RTLD_BOOTSTRAP
__attribute__ ((always_inline))
#endif
elf_machine_rel (struct link_map *map, const ElfW(Rel) *reloc,
const ElfW(Sym) *sym, const struct r_found_version *version,
/* We use void* because the location to be relocated
is not required to be properly aligned for a
ELFW(Addr). */
void /* ElfW(Addr) */ *const reloc_addr)
{
const unsigned long int r_type = ELFW(R_TYPE) (reloc->r_info);
#if !defined RTLD_BOOTSTRAP && !defined SHARED
/* This is defined in rtld.c, but nowhere in the static libc.a;
make the reference weak so static programs can still link. This
declaration cannot be done when compiling rtld.c (i.e. #ifdef
RTLD_BOOTSTRAP) because rtld.c contains the common defn for
_dl_rtld_map, which is incompatible with a weak decl in the same
file. */
weak_extern (GL(dl_rtld_map));
#endif
switch (r_type)
{
#if _MIPS_SIM == _MIPS_SIM_ABI64
case (R_MIPS_64 << 8) | R_MIPS_REL32:
#else
case R_MIPS_REL32:
#endif
{
int symidx = ELFW(R_SYM) (reloc->r_info);
ElfW(Addr) reloc_value;
/* Support relocations on mis-aligned offsets. Should we ever
implement RELA, this should be replaced with an assignment
from reloc->r_addend. */
__builtin_memcpy (&reloc_value, reloc_addr, sizeof (reloc_value));
if (symidx)
{
const ElfW(Word) gotsym
= (const ElfW(Word)) map->l_info[DT_MIPS (GOTSYM)]->d_un.d_val;
if ((ElfW(Word))symidx < gotsym)
{
/* This wouldn't work for a symbol imported from other
libraries for which there's no GOT entry, but MIPS
requires every symbol referenced in a dynamic
relocation to have a GOT entry in the primary GOT,
so we only get here for locally-defined symbols.
For section symbols, we should *NOT* be adding
sym->st_value (per the definition of the meaning of
S in reloc expressions in the ELF64 MIPS ABI),
since it should have already been added to
reloc_value by the linker, but older versions of
GNU ld didn't add it, and newer versions don't emit
useless relocations to section symbols any more, so
it is safe to keep on adding sym->st_value, even
though it's not ABI compliant. Some day we should
bite the bullet and stop doing this. */
#ifndef RTLD_BOOTSTRAP
if (map != &GL(dl_rtld_map))
#endif
reloc_value += sym->st_value + map->l_addr;
}
else
{
#ifndef RTLD_BOOTSTRAP
const ElfW(Addr) *got
= (const ElfW(Addr) *) D_PTR (map, l_info[DT_PLTGOT]);
const ElfW(Word) local_gotno
= (const ElfW(Word))
map->l_info[DT_MIPS (LOCAL_GOTNO)]->d_un.d_val;
reloc_value += got[symidx + local_gotno - gotsym];
#endif
}
}
else
#ifndef RTLD_BOOTSTRAP
if (map != &GL(dl_rtld_map))
#endif
reloc_value += map->l_addr;
__builtin_memcpy (reloc_addr, &reloc_value, sizeof (reloc_value));
}
break;
case R_MIPS_NONE: /* Alright, Wilbur. */
break;
#if _MIPS_SIM == _MIPS_SIM_ABI64
case R_MIPS_64:
/* For full compliance with the ELF64 ABI, one must precede the
_REL32/_64 pair of relocations with a _64 relocation, such
that the in-place addend is read as a 64-bit value. IRIX
didn't pick up on this requirement, so we treat the
_REL32/_64 relocation as a 64-bit relocation even if it's by
itself. For ABI compliance, we ignore such _64 dummy
relocations. For RELA, this may be simply removed, since
it's totally unnecessary. */
if (ELFW(R_SYM) (reloc->r_info) == 0)
break;
/* Fall through. */
#endif
default:
_dl_reloc_bad_type (map, r_type, 0);
break;
}
}
static inline void
elf_machine_rel_relative (ElfW(Addr) l_addr, const ElfW(Rel) *reloc,
void /* ElfW(Addr) */ *const reloc_addr)
{
/* XXX Nothing to do. There is no relative relocation, right? */
}
static inline void
elf_machine_lazy_rel (struct link_map *map,
ElfW(Addr) l_addr, const ElfW(Rel) *reloc)
{
/* Do nothing. */
}
#ifndef RTLD_BOOTSTRAP
/* Relocate GOT. */
static inline void
elf_machine_got_rel (struct link_map *map, int lazy)
{
ElfW(Addr) *got;
ElfW(Sym) *sym;
const ElfW(Half) *vernum;
int i, n, symidx;
#define RESOLVE_GOTSYM(sym,vernum,sym_index) \
({ \
const ElfW(Sym) *ref = sym; \
const struct r_found_version *version \
= vernum ? &map->l_versions[vernum[sym_index] & 0x7fff] : NULL; \
ElfW(Addr) value; \
value = RESOLVE (&ref, version, R_MIPS_REL32); \
(ref)? value + ref->st_value: 0; \
})
if (map->l_info[VERSYMIDX (DT_VERSYM)] != NULL)
vernum = (const void *) D_PTR (map, l_info[VERSYMIDX (DT_VERSYM)]);
else
vernum = NULL;
got = (ElfW(Addr) *) D_PTR (map, l_info[DT_PLTGOT]);
n = map->l_info[DT_MIPS (LOCAL_GOTNO)]->d_un.d_val;
/* The dynamic linker's local got entries have already been relocated. */
if (map != &GL(dl_rtld_map))
{
/* got[0] is reserved. got[1] is also reserved for the dynamic object
generated by gnu ld. Skip these reserved entries from relocation. */
i = (got[1] & ELF_MIPS_GNU_GOT1_MASK)? 2 : 1;
/* Add the run-time displacement to all local got entries if
needed. */
if (__builtin_expect (map->l_addr != 0, 0))
{
while (i < n)
got[i++] += map->l_addr;
}
}
/* Handle global got entries. */
got += n;
/* Keep track of the symbol index. */
symidx = map->l_info[DT_MIPS (GOTSYM)]->d_un.d_val;
sym = (ElfW(Sym) *) D_PTR (map, l_info[DT_SYMTAB]) + symidx;
i = (map->l_info[DT_MIPS (SYMTABNO)]->d_un.d_val
- map->l_info[DT_MIPS (GOTSYM)]->d_un.d_val);
/* This loop doesn't handle Quickstart. */
while (i--)
{
if (sym->st_shndx == SHN_UNDEF)
{
if (ELFW(ST_TYPE) (sym->st_info) == STT_FUNC
&& sym->st_value && lazy)
*got = sym->st_value + map->l_addr;
else
*got = RESOLVE_GOTSYM (sym, vernum, symidx);
}
else if (sym->st_shndx == SHN_COMMON)
*got = RESOLVE_GOTSYM (sym, vernum, symidx);
else if (ELFW(ST_TYPE) (sym->st_info) == STT_FUNC
&& *got != sym->st_value
&& lazy)
*got += map->l_addr;
else if (ELFW(ST_TYPE) (sym->st_info) == STT_SECTION)
{
if (sym->st_other == 0)
*got += map->l_addr;
}
else
*got = RESOLVE_GOTSYM (sym, vernum, symidx);
++got;
++sym;
++symidx;
}
#undef RESOLVE_GOTSYM
}
#endif
/* Set up the loaded object described by L so its stub function
will jump to the on-demand fixup code __dl_runtime_resolve. */
static inline int
elf_machine_runtime_setup (struct link_map *l, int lazy, int profile)
{
# ifndef RTLD_BOOTSTRAP
ElfW(Addr) *got;
extern void _dl_runtime_resolve (ElfW(Word));
extern int _dl_mips_gnu_objects;
if (lazy)
{
/* The GOT entries for functions have not yet been filled in.
Their initial contents will arrange when called to put an
offset into the .dynsym section in t8, the return address
in t7 and then jump to _GLOBAL_OFFSET_TABLE[0]. */
got = (ElfW(Addr) *) D_PTR (l, l_info[DT_PLTGOT]);
/* This function will get called to fix up the GOT entry indicated by
the register t8, and then jump to the resolved address. */
got[0] = (ElfW(Addr)) &_dl_runtime_resolve;
/* Store l to _GLOBAL_OFFSET_TABLE[1] for gnu object. The MSB
of got[1] of a gnu object is set to identify gnu objects.
Where we can store l for non gnu objects? XXX */
if ((got[1] & ELF_MIPS_GNU_GOT1_MASK) != 0)
got[1] = ((ElfW(Addr)) l | ELF_MIPS_GNU_GOT1_MASK);
else
_dl_mips_gnu_objects = 0;
}
/* Relocate global offset table. */
elf_machine_got_rel (l, lazy);
# endif
return lazy;
}
#endif /* RESOLVE */
Reference in New Issue View Git Blame Copy Permalink