mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-30 00:31:08 +00:00
60196d2ef2
With DT_RELR, there may be no relocations in DT_RELA/DT_REL and their entry values are zero. Don't relocate DT_RELA/DT_REL and update the combined relocation start address if their entry values are zero.
198 lines
8.0 KiB
C
198 lines
8.0 KiB
C
/* Inline functions for dynamic linking.
|
|
Copyright (C) 1995-2022 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
|
|
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, see
|
|
<https://www.gnu.org/licenses/>. */
|
|
|
|
#include <dl-machine.h>
|
|
#include <elf.h>
|
|
|
|
#ifdef RESOLVE_MAP
|
|
/* We pass reloc_addr as a pointer to void, as opposed to a pointer to
|
|
ElfW(Addr), because not all architectures can assume that the
|
|
relocated address is properly aligned, whereas the compiler is
|
|
entitled to assume that a pointer to a type is properly aligned for
|
|
the type. Even if we cast the pointer back to some other type with
|
|
less strict alignment requirements, the compiler might still
|
|
remember that the pointer was originally more aligned, thereby
|
|
optimizing away alignment tests or using word instructions for
|
|
copying memory, breaking the very code written to handle the
|
|
unaligned cases. */
|
|
# if ! ELF_MACHINE_NO_REL
|
|
static inline void __attribute__((always_inline))
|
|
elf_machine_rel (struct link_map *map, struct r_scope_elem *scope[],
|
|
const ElfW(Rel) *reloc, const ElfW(Sym) *sym,
|
|
const struct r_found_version *version,
|
|
void *const reloc_addr, int skip_ifunc);
|
|
static inline void __attribute__((always_inline))
|
|
elf_machine_rel_relative (ElfW(Addr) l_addr, const ElfW(Rel) *reloc,
|
|
void *const reloc_addr);
|
|
# endif
|
|
# if ! ELF_MACHINE_NO_RELA
|
|
static inline void __attribute__((always_inline))
|
|
elf_machine_rela (struct link_map *map, struct r_scope_elem *scope[],
|
|
const ElfW(Rela) *reloc, const ElfW(Sym) *sym,
|
|
const struct r_found_version *version, void *const reloc_addr,
|
|
int skip_ifunc);
|
|
static inline void __attribute__((always_inline))
|
|
elf_machine_rela_relative (ElfW(Addr) l_addr, const ElfW(Rela) *reloc,
|
|
void *const reloc_addr);
|
|
# endif
|
|
# if ELF_MACHINE_NO_RELA || defined ELF_MACHINE_PLT_REL
|
|
static inline void __attribute__((always_inline))
|
|
elf_machine_lazy_rel (struct link_map *map, struct r_scope_elem *scope[],
|
|
ElfW(Addr) l_addr, const ElfW(Rel) *reloc,
|
|
int skip_ifunc);
|
|
# else
|
|
static inline void __attribute__((always_inline))
|
|
elf_machine_lazy_rel (struct link_map *map, struct r_scope_elem *scope[],
|
|
ElfW(Addr) l_addr, const ElfW(Rela) *reloc,
|
|
int skip_ifunc);
|
|
# endif
|
|
#endif
|
|
|
|
#ifdef RESOLVE_MAP
|
|
|
|
/* Get the definitions of `elf_dynamic_do_rel' and `elf_dynamic_do_rela'.
|
|
These functions are almost identical, so we use cpp magic to avoid
|
|
duplicating their code. It cannot be done in a more general function
|
|
because we must be able to completely inline. */
|
|
|
|
/* On some machines, notably SPARC, DT_REL* includes DT_JMPREL in its
|
|
range. Note that according to the ELF spec, this is completely legal!
|
|
|
|
We are guarenteed that we have one of three situations. Either DT_JMPREL
|
|
comes immediately after DT_REL*, or there is overlap and DT_JMPREL
|
|
consumes precisely the very end of the DT_REL*, or DT_JMPREL and DT_REL*
|
|
are completely separate and there is a gap between them. */
|
|
|
|
# define _ELF_DYNAMIC_DO_RELOC(RELOC, reloc, map, scope, do_lazy, skip_ifunc, test_rel) \
|
|
do { \
|
|
struct { ElfW(Addr) start, size; \
|
|
__typeof (((ElfW(Dyn) *) 0)->d_un.d_val) nrelative; int lazy; } \
|
|
ranges[2] = { { 0, 0, 0, 0 }, { 0, 0, 0, 0 } }; \
|
|
\
|
|
/* With DT_RELR, DT_RELA/DT_REL can have zero value. */ \
|
|
if ((map)->l_info[DT_##RELOC] != NULL \
|
|
&& (map)->l_info[DT_##RELOC]->d_un.d_ptr != 0) \
|
|
{ \
|
|
ranges[0].start = D_PTR ((map), l_info[DT_##RELOC]); \
|
|
ranges[0].size = (map)->l_info[DT_##RELOC##SZ]->d_un.d_val; \
|
|
if (map->l_info[VERSYMIDX (DT_##RELOC##COUNT)] != NULL) \
|
|
ranges[0].nrelative \
|
|
= map->l_info[VERSYMIDX (DT_##RELOC##COUNT)]->d_un.d_val; \
|
|
} \
|
|
if ((map)->l_info[DT_PLTREL] \
|
|
&& (!test_rel || (map)->l_info[DT_PLTREL]->d_un.d_val == DT_##RELOC)) \
|
|
{ \
|
|
ElfW(Addr) start = D_PTR ((map), l_info[DT_JMPREL]); \
|
|
ElfW(Addr) size = (map)->l_info[DT_PLTRELSZ]->d_un.d_val; \
|
|
\
|
|
if (ranges[0].start == 0) \
|
|
ranges[0].start = start; \
|
|
if (ranges[0].start + ranges[0].size == (start + size)) \
|
|
ranges[0].size -= size; \
|
|
if (!(do_lazy) \
|
|
&& (ranges[0].start + ranges[0].size) == start) \
|
|
{ \
|
|
/* Combine processing the sections. */ \
|
|
ranges[0].size += size; \
|
|
} \
|
|
else \
|
|
{ \
|
|
ranges[1].start = start; \
|
|
ranges[1].size = size; \
|
|
ranges[1].lazy = (do_lazy); \
|
|
} \
|
|
} \
|
|
\
|
|
for (int ranges_index = 0; ranges_index < 2; ++ranges_index) \
|
|
elf_dynamic_do_##reloc ((map), scope, \
|
|
ranges[ranges_index].start, \
|
|
ranges[ranges_index].size, \
|
|
ranges[ranges_index].nrelative, \
|
|
ranges[ranges_index].lazy, \
|
|
skip_ifunc); \
|
|
} while (0)
|
|
|
|
# if ELF_MACHINE_NO_REL || ELF_MACHINE_NO_RELA
|
|
# define _ELF_CHECK_REL 0
|
|
# else
|
|
# define _ELF_CHECK_REL 1
|
|
# endif
|
|
|
|
# if ! ELF_MACHINE_NO_REL
|
|
# include "do-rel.h"
|
|
# define ELF_DYNAMIC_DO_REL(map, scope, lazy, skip_ifunc) \
|
|
_ELF_DYNAMIC_DO_RELOC (REL, Rel, map, scope, lazy, skip_ifunc, _ELF_CHECK_REL)
|
|
# else
|
|
# define ELF_DYNAMIC_DO_REL(map, scope, lazy, skip_ifunc) /* Nothing to do. */
|
|
# endif
|
|
|
|
# if ! ELF_MACHINE_NO_RELA
|
|
# define DO_RELA
|
|
# include "do-rel.h"
|
|
# define ELF_DYNAMIC_DO_RELA(map, scope, lazy, skip_ifunc) \
|
|
_ELF_DYNAMIC_DO_RELOC (RELA, Rela, map, scope, lazy, skip_ifunc, _ELF_CHECK_REL)
|
|
# else
|
|
# define ELF_DYNAMIC_DO_RELA(map, scope, lazy, skip_ifunc) /* Nothing to do. */
|
|
# endif
|
|
|
|
# define ELF_DYNAMIC_DO_RELR(map) \
|
|
do { \
|
|
ElfW(Addr) l_addr = (map)->l_addr, *where = 0; \
|
|
const ElfW(Relr) *r, *end; \
|
|
if ((map)->l_info[DT_RELR] == NULL) \
|
|
break; \
|
|
r = (const ElfW(Relr) *)D_PTR((map), l_info[DT_RELR]); \
|
|
end = (const ElfW(Relr) *)((const char *)r + \
|
|
(map)->l_info[DT_RELRSZ]->d_un.d_val); \
|
|
for (; r < end; r++) \
|
|
{ \
|
|
ElfW(Relr) entry = *r; \
|
|
if ((entry & 1) == 0) \
|
|
{ \
|
|
where = (ElfW(Addr) *)(l_addr + entry); \
|
|
*where++ += l_addr; \
|
|
} \
|
|
else \
|
|
{ \
|
|
for (long int i = 0; (entry >>= 1) != 0; i++) \
|
|
if ((entry & 1) != 0) \
|
|
where[i] += l_addr; \
|
|
where += CHAR_BIT * sizeof(ElfW(Relr)) - 1; \
|
|
} \
|
|
} \
|
|
} while (0);
|
|
|
|
/* This can't just be an inline function because GCC is too dumb
|
|
to inline functions containing inlines themselves. */
|
|
# ifdef RTLD_BOOTSTRAP
|
|
# define DO_RTLD_BOOTSTRAP 1
|
|
# else
|
|
# define DO_RTLD_BOOTSTRAP 0
|
|
# endif
|
|
# define ELF_DYNAMIC_RELOCATE(map, scope, lazy, consider_profile, skip_ifunc) \
|
|
do { \
|
|
int edr_lazy = elf_machine_runtime_setup ((map), (scope), (lazy), \
|
|
(consider_profile)); \
|
|
if (((map) != &GL(dl_rtld_map) || DO_RTLD_BOOTSTRAP)) \
|
|
ELF_DYNAMIC_DO_RELR (map); \
|
|
ELF_DYNAMIC_DO_REL ((map), (scope), edr_lazy, skip_ifunc); \
|
|
ELF_DYNAMIC_DO_RELA ((map), (scope), edr_lazy, skip_ifunc); \
|
|
} while (0)
|
|
|
|
#endif
|