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Finish IFUNC support for x86 and x86-64.

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Add support for the IRELAIVE relocation and IFUNC in static executables.
This commit is contained in:
Ulrich Drepper 2009-05-31 23:45:33 -07:00
parent 963cb6fcb4
commit 7441470835
9 changed files with 225 additions and 2 deletions
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27
ChangeLog
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@ -1,3 +1,30 @@
2009-05-29 H.J. Lu <hongjiu.lu@intel.com>
* csu/elf-init.c: Include <link.h> and <dl-irel.h> if LIBC_NONSHARED
is not defined.
(__rela_iplt_start): New declaration.
(__rela_iplt_end): Likewise.
(__rel_iplt_start): Likewise.
(__rel_iplt_end): Likewise.
(__libc_csu_init): Process __rela_iplt_start and __rel_iplt_start.
* elf/elf.h (R_386_IRELATIVE): New macro.
(R_X86_64_IRELATIVE): New macro.
(R_386_NUM): Updated.
(R_X86_64_NUM): Likewise.
* include/libc-symbols.h (libc_ifunc_hidden_def1): New macro.
(libc_ifunc_hidden_def): New macro.
* sysdeps/generic/dl-irel.h: New file.
* sysdeps/i386/dl-irel.h: New file.
* sysdeps/x86_64/dl-irel.h: New file.
* sysdeps/i386/dl-machine.h (elf_machine_rel): Handle R_386_IRELATIVE.
(elf_machine_rela): Check SHN_UNDEF for STT_GNU_IFUNC symbol.
Handle R_386_IRELATIVE.
(elf_machine_lazy_rel): Handle R_386_IRELATIVE.
(elf_machine_lazy_rela): Likewise.
* sysdeps/x86_64/dl-machine.h (elf_machine_rela): Handle
R_X86_64_IRELATIVE.
(elf_machine_lazy_rel): Handle R_X86_64_IRELATIVE.
2009-05-31 Ulrich Drepper <drepper@redhat.com>
* sysdeps/x86_64/multiarch/init-arch.h: Define COMMON_CPUID_INDEX_1

30
csu/elf-init.c
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@ -36,6 +36,20 @@
#include <stddef.h>
#ifndef LIBC_NONSHARED
# include <link.h>
# include <dl-irel.h>
# ifdef ELF_MACHINE_IRELA
extern const ElfW(Rela) __rela_iplt_start [];
extern const ElfW(Rela) __rela_iplt_end [];
# endif
# ifdef ELF_MACHINE_IREL
extern const ElfW(Rel) __rel_iplt_start [];
extern const ElfW(Rel) __rel_iplt_end [];
# endif
#endif /* LIBC_NONSHARED */
/* These magic symbols are provided by the linker. */
extern void (*__preinit_array_start []) (int, char **, char **)
@ -67,6 +81,22 @@ __libc_csu_init (int argc, char **argv, char **envp)
the dynamic linker (before initializing any shared object. */
#ifndef LIBC_NONSHARED
# ifdef ELF_MACHINE_IRELA
{
const size_t size = __rela_iplt_end - __rela_iplt_start;
for (size_t i = 0; i < size; i++)
elf_irela (&__rela_iplt_start [i]);
}
# endif
# ifdef ELF_MACHINE_IREL
{
const size_t size = __rel_iplt_end - __rel_iplt_start;
for (size_t i = 0; i < size; i++)
elf_irel (&__rel_iplt_start [i]);
}
# endif
/* For static executables, preinit happens rights before init. */
{
const size_t size = __preinit_array_end - __preinit_array_start;

6
elf/elf.h
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@ -1177,8 +1177,9 @@ typedef struct
pointer to code and to
argument, returning the TLS
offset for the symbol. */
#define R_386_IRELATIVE 42 /* Adjust indirectly by program base */
/* Keep this the last entry. */
#define R_386_NUM 42
#define R_386_NUM 43
/* SUN SPARC specific definitions. */
@ -2625,8 +2626,9 @@ typedef Elf32_Addr Elf32_Conflict;
#define R_X86_64_TLSDESC_CALL 35 /* Marker for call through TLS
descriptor. */
#define R_X86_64_TLSDESC 36 /* TLS descriptor. */
#define R_X86_64_IRELATIVE 37 /* Adjust indirectly by program base */
#define R_X86_64_NUM 37
#define R_X86_64_NUM 38
/* AM33 relocations. */

17
include/libc-symbols.h
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@ -845,4 +845,21 @@ for linking")
} \
__asm__ (".type " #name ", %gnu_indirect_function");
#ifdef HAVE_ASM_SET_DIRECTIVE
# define libc_ifunc_hidden_def1(local, name) \
__asm__ (declare_symbol_alias_1_stringify (ASM_GLOBAL_DIRECTIVE) \
" " #local "\n\t" \
".hidden " #local "\n\t" \
".set " #local ", " #name);
#else
# define libc_ifunc_hidden_def1(local, name) \
__asm__ (declare_symbol_alias_1_stringify (ASM_GLOBAL_DIRECTIVE) \
" " #local "\n\t" \
".hidden " #local "\n\t" \
#local " = " #name);
#endif
#define libc_ifunc_hidden_def(name) \
libc_ifunc_hidden_def1 (__GI_##name, name)
#endif /* libc-symbols.h */

23
sysdeps/generic/dl-irel.h Normal file
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@ -0,0 +1,23 @@
/* Machine-dependent ELF indirect relocation inline functions.
Copyright (C) 2009 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, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#ifndef _DL_IREL_h
#define _DL_IREL_H
#endif /* dl-irel.h */

44
sysdeps/i386/dl-irel.h Normal file
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@ -0,0 +1,44 @@
/* Machine-dependent ELF indirect relocation inline functions.
i386 version.
Copyright (C) 2009 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, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#ifndef _DL_IREL_H
#define _DL_IREL_H
#include <unistd.h>
#define ELF_MACHINE_IREL 1
static inline void
__attribute ((always_inline))
elf_irel (const Elf32_Rel *reloc)
{
Elf32_Addr *const reloc_addr = (void *) reloc->r_offset;
const unsigned long int r_type = ELF32_R_TYPE (reloc->r_info);
if (__builtin_expect (r_type == R_386_IRELATIVE, 1))
{
Elf64_Addr value = ((Elf32_Addr (*) (void)) (*reloc_addr)) ();
*reloc_addr = value;
}
else
_exit (-1);
}
#endif /* dl-irel.h */

24
sysdeps/i386/dl-machine.h
View File

@ -345,6 +345,7 @@ elf_machine_rel (struct link_map *map, const Elf32_Rel *reloc,
Elf32_Addr value = sym_map == NULL ? 0 : sym_map->l_addr + sym->st_value;
if (sym != NULL
&& __builtin_expect (sym->st_shndx != SHN_UNDEF, 1)
&& __builtin_expect (ELFW(ST_TYPE) (sym->st_info) == STT_GNU_IFUNC,
0))
value = ((Elf32_Addr (*) (void)) value) ();
@ -471,6 +472,11 @@ elf_machine_rel (struct link_map *map, const Elf32_Rel *reloc,
memcpy (reloc_addr_arg, (void *) value,
MIN (sym->st_size, refsym->st_size));
break;
case R_386_IRELATIVE:
value = map->l_addr + *reloc_addr;
value = ((Elf32_Addr (*) (void)) value) ();
*reloc_addr = value;
break;
default:
_dl_reloc_bad_type (map, r_type, 0);
break;
@ -500,6 +506,7 @@ elf_machine_rela (struct link_map *map, const Elf32_Rela *reloc,
Elf32_Addr value = sym == NULL ? 0 : sym_map->l_addr + sym->st_value;
if (sym != NULL
&& __builtin_expect (sym->st_shndx != SHN_UNDEF, 1)
&& __builtin_expect (ELFW(ST_TYPE) (sym->st_info) == STT_GNU_IFUNC,
0))
value = ((Elf32_Addr (*) (void)) value) ();
@ -609,6 +616,11 @@ elf_machine_rela (struct link_map *map, const Elf32_Rela *reloc,
MIN (sym->st_size, refsym->st_size));
break;
# endif /* !RESOLVE_CONFLICT_FIND_MAP */
case R_386_IRELATIVE:
value = map->l_addr + reloc->r_addend;
value = ((Elf32_Addr (*) (void)) value) ();
*reloc_addr = value;
break;
default:
/* We add these checks in the version to relocate ld.so only
if we are still debugging. */
@ -703,6 +715,12 @@ elf_machine_lazy_rel (struct link_map *map,
# endif
}
}
else if (__builtin_expect (r_type == R_386_IRELATIVE, 0))
{
Elf32_Addr value = map->l_addr + *reloc_addr;
value = ((Elf32_Addr (*) (void)) value) ();
*reloc_addr = value;
}
else
_dl_reloc_bad_type (map, r_type, 1);
}
@ -726,6 +744,12 @@ elf_machine_lazy_rela (struct link_map *map,
td->arg = (void*)reloc;
td->entry = _dl_tlsdesc_resolve_rela;
}
else if (__builtin_expect (r_type == R_386_IRELATIVE, 0))
{
Elf32_Addr value = map->l_addr + reloc->r_addend;
value = ((Elf32_Addr (*) (void)) value) ();
*reloc_addr = value;
}
else
_dl_reloc_bad_type (map, r_type, 1);
}

44
sysdeps/x86_64/dl-irel.h Normal file
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@ -0,0 +1,44 @@
/* Machine-dependent ELF indirect relocation inline functions.
x86-64 version.
Copyright (C) 2009 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, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#ifndef _DL_IREL_H
#define _DL_IREL_H
#include <unistd.h>
#define ELF_MACHINE_IRELA 1
static inline void
__attribute ((always_inline))
elf_irela (const Elf64_Rela *reloc)
{
Elf64_Addr *const reloc_addr = (void *) reloc->r_offset;
const unsigned long int r_type = ELF64_R_TYPE (reloc->r_info);
if (__builtin_expect (r_type == R_X86_64_IRELATIVE, 1))
{
Elf64_Addr value = ((Elf64_Addr (*) (void)) reloc->r_addend) ();
*reloc_addr = value;
}
else
_exit (-1);
}
#endif /* dl-irel.h */

12
sysdeps/x86_64/dl-machine.h
View File

@ -297,6 +297,7 @@ elf_machine_rela (struct link_map *map, const Elf64_Rela *reloc,
: (Elf64_Addr) sym_map->l_addr + sym->st_value);
if (sym != NULL
&& __builtin_expect (sym->st_shndx != SHN_UNDEF, 1)
&& __builtin_expect (ELFW(ST_TYPE) (sym->st_info) == STT_GNU_IFUNC,
0))
value = ((Elf64_Addr (*) (void)) value) ();
@ -442,6 +443,11 @@ elf_machine_rela (struct link_map *map, const Elf64_Rela *reloc,
}
break;
# endif
case R_X86_64_IRELATIVE:
value = map->l_addr + reloc->r_addend;
value = ((Elf64_Addr (*) (void)) value) ();
*reloc_addr = value;
break;
default:
_dl_reloc_bad_type (map, r_type, 0);
break;
@ -488,6 +494,12 @@ elf_machine_lazy_rel (struct link_map *map,
td->entry = (void*)(D_PTR (map, l_info[ADDRIDX (DT_TLSDESC_PLT)])
+ map->l_addr);
}
else if (__builtin_expect (r_type == R_X86_64_IRELATIVE, 0))
{
Elf64_Addr value = map->l_addr + reloc->r_addend;
value = ((Elf64_Addr (*) (void)) value) ();
*reloc_addr = value;
}
else
_dl_reloc_bad_type (map, r_type, 1);
}