Implement IFUNC for PPC.

This commit is contained in:
Alan Modra 2009-10-30 00:39:38 -07:00 committed by Ulrich Drepper
parent 9fd76770c3
commit 77799d9d9b
7 changed files with 187 additions and 14 deletions

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@ -1,4 +1,24 @@
2009-10-30 Ulrich Drepper <drepper@redhat.com>
2009-07-30 Alan Modra <amodra@bigpond.net.au>
* elf/elf.h (R_PPC_NUM, R_PPC64_NUM): Delete unused and incorrect.
(R_PPC_REL16*): Correct comments.
(R_PPC_IRELATIVE, R_PPC64_IRELATIVE, R_PPC64_JMP_IREL): Define.
(R_PPC64_REL16, R_PPC64_REL16_LO, R_PPC64_REL16_HI,
R_PPC64_REL16_HA): Define.
* sysdeps/powerpc/powerpc32/dl-irel.h: New file.
* sysdeps/powerpc/powerpc64/dl-irel.h: New file.
* sysdeps/powerpc/powerpc32/dl-machine.c (__elf_machine_fixup_plt):
Delete unused "reloc" param.
(__process_machine_rela): Handle R_PPC_IRELATIVE.
* sysdeps/powerpc/powerpc32/dl-machine.h (__elf_machine_fixup_plt):
Delete "reloc" param.
(elf_machine_rela): Handle STT_GNU_IFUNC functions and
R_PPC_IRELATIVE.
* sysdeps/powerpc/powerpc64/dl-machine.h (resolve_ifunc): New function.
(elf_machine_rela): Handle STT_GNU_IFUNC functions and new ifunc
relocations.
d2009-10-30 Ulrich Drepper <drepper@redhat.com>
[BZ #10315]
* sysdeps/gnu/netinet/udp.h: Define UDP_CORK, UDP_ENCAP,

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@ -2041,9 +2041,6 @@ typedef Elf32_Addr Elf32_Conflict;
#define R_PPC_GOT_DTPREL16_HI 93 /* half16* (sym+add)@got@dtprel@h */
#define R_PPC_GOT_DTPREL16_HA 94 /* half16* (sym+add)@got@dtprel@ha */
/* Keep this the last entry. */
#define R_PPC_NUM 95
/* The remaining relocs are from the Embedded ELF ABI, and are not
in the SVR4 ELF ABI. */
#define R_PPC_EMB_NADDR32 101
@ -2071,11 +2068,14 @@ typedef Elf32_Addr Elf32_Conflict;
#define R_PPC_DIAB_RELSDA_HI 184 /* like EMB_RELSDA, but high 16 bit */
#define R_PPC_DIAB_RELSDA_HA 185 /* like EMB_RELSDA, adjusted high 16 */
/* GNU extension to support local ifunc. */
#define R_PPC_IRELATIVE 248
/* GNU relocs used in PIC code sequences. */
#define R_PPC_REL16 249 /* word32 (sym-.) */
#define R_PPC_REL16_LO 250 /* half16 (sym-.)@l */
#define R_PPC_REL16_HI 251 /* half16 (sym-.)@h */
#define R_PPC_REL16_HA 252 /* half16 (sym-.)@ha */
#define R_PPC_REL16 249 /* half16 (sym+add-.) */
#define R_PPC_REL16_LO 250 /* half16 (sym+add-.)@l */
#define R_PPC_REL16_HI 251 /* half16 (sym+add-.)@h */
#define R_PPC_REL16_HA 252 /* half16 (sym+add-.)@ha */
/* This is a phony reloc to handle any old fashioned TOC16 references
that may still be in object files. */
@ -2197,8 +2197,13 @@ typedef Elf32_Addr Elf32_Conflict;
#define R_PPC64_DTPREL16_HIGHEST 105 /* half16 (sym+add)@dtprel@highest */
#define R_PPC64_DTPREL16_HIGHESTA 106 /* half16 (sym+add)@dtprel@highesta */
/* Keep this the last entry. */
#define R_PPC64_NUM 107
/* GNU extension to support local ifunc. */
#define R_PPC64_JMP_IREL 247
#define R_PPC64_IRELATIVE 248
#define R_PPC64_REL16 249 /* half16 (sym+add-.) */
#define R_PPC64_REL16_LO 250 /* half16 (sym+add-.)@l */
#define R_PPC64_REL16_HI 251 /* half16 (sym+add-.)@h */
#define R_PPC64_REL16_HA 252 /* half16 (sym+add-.)@ha */
/* PowerPC64 specific values for the Dyn d_tag field. */
#define DT_PPC64_GLINK (DT_LOPROC + 0)

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@ -0,0 +1,45 @@
/* Machine-dependent ELF indirect relocation inline functions.
PowerPC 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 <stdio.h>
#include <unistd.h>
#define ELF_MACHINE_IRELA 1
static inline void
__attribute ((always_inline))
elf_irela (const Elf32_Rela *reloc)
{
unsigned int r_type = ELF32_R_TYPE (reloc->r_info);
if (__builtin_expect (r_type == R_PPC_IRELATIVE, 1))
{
Elf32_Addr *const reloc_addr = (void *) reloc->r_offset;
Elf32_Addr value = ((Elf32_Addr (*) (void)) reloc->r_addend) ();
*reloc_addr = value;
}
else
__libc_fatal ("unexpected reloc type in static binary");
}
#endif /* dl-irel.h */

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@ -337,7 +337,7 @@ __elf_machine_runtime_setup (struct link_map *map, int lazy, int profile)
}
Elf32_Addr
__elf_machine_fixup_plt (struct link_map *map, const Elf32_Rela *reloc,
__elf_machine_fixup_plt (struct link_map *map,
Elf32_Addr *reloc_addr, Elf32_Addr finaladdr)
{
Elf32_Sword delta = finaladdr - (Elf32_Word) reloc_addr;
@ -430,6 +430,10 @@ __process_machine_rela (struct link_map *map,
*reloc_addr = finaladdr;
return;
case R_PPC_IRELATIVE:
*reloc_addr = ((Elf32_Addr (*) (void)) finaladdr) ();
return;
case R_PPC_UADDR32:
((char *) reloc_addr)[0] = finaladdr >> 24;
((char *) reloc_addr)[1] = finaladdr >> 16;

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@ -226,7 +226,6 @@ elf_machine_runtime_setup (struct link_map *map,
/* Change the PLT entry whose reloc is 'reloc' to call the actual routine. */
extern Elf32_Addr __elf_machine_fixup_plt (struct link_map *map,
const Elf32_Rela *reloc,
Elf32_Addr *reloc_addr,
Elf32_Addr finaladdr);
@ -237,7 +236,7 @@ elf_machine_fixup_plt (struct link_map *map, lookup_t t,
{
if (map->l_info[DT_PPC(GOT)] == 0)
/* Handle old style PLT. */
return __elf_machine_fixup_plt (map, reloc, reloc_addr, finaladdr);
return __elf_machine_fixup_plt (map, reloc_addr, finaladdr);
*reloc_addr = finaladdr;
return finaladdr;
@ -317,6 +316,11 @@ elf_machine_rela (struct link_map *map, const Elf32_Rela *reloc,
value = reloc->r_addend;
#endif
if (sym != NULL
&& __builtin_expect (ELFW(ST_TYPE) (sym->st_info) == STT_GNU_IFUNC, 0)
&& __builtin_expect (sym->st_shndx != SHN_UNDEF, 1))
value = ((Elf32_Addr (*) (void)) value) ();
/* A small amount of code is duplicated here for speed. In libc,
more than 90% of the relocs are R_PPC_RELATIVE; in the X11 shared
libraries, 60% are R_PPC_RELATIVE, 24% are R_PPC_GLOB_DAT or

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@ -0,0 +1,58 @@
/* Machine-dependent ELF indirect relocation inline functions.
PowerPC64 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 <stdio.h>
#include <unistd.h>
#define ELF_MACHINE_IRELA 1
typedef struct
{
Elf64_Addr fd_func;
Elf64_Addr fd_toc;
Elf64_Addr fd_aux;
} Elf64_FuncDesc;
static inline void
__attribute ((always_inline))
elf_irela (const Elf64_Rela *reloc)
{
unsigned int r_type = ELF64_R_TYPE (reloc->r_info);
if (__builtin_expect (r_type == R_PPC64_IRELATIVE, 1))
{
Elf64_Addr *const reloc_addr = (void *) reloc->r_offset;
Elf64_Addr value = ((Elf64_Addr (*) (void)) reloc->r_addend) ();
*reloc_addr = value;
}
else if (__builtin_expect (r_type == R_PPC64_JMP_IREL, 1))
{
Elf64_Addr *const reloc_addr = (void *) reloc->r_offset;
Elf64_Addr value = ((Elf64_Addr (*) (void)) reloc->r_addend) ();
*(Elf64_FuncDesc *) reloc_addr = *(Elf64_FuncDesc *) value;
}
else
__libc_fatal ("unexpected reloc type in static binary");
}
#endif /* dl-irel.h */

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@ -526,6 +526,29 @@ elf_machine_tprel (struct link_map *map,
}
#endif
/* Call function at address VALUE (an OPD entry) to resolve ifunc relocs. */
auto inline Elf64_Addr __attribute__ ((always_inline))
resolve_ifunc (Elf64_Addr value,
const struct link_map *map, const struct link_map *sym_map)
{
/* The function we are calling may not yet have its opd entry relocated. */
Elf64_FuncDesc opd;
if (map != sym_map
#if !defined RTLD_BOOTSTRAP && defined SHARED
/* Bootstrap map doesn't have l_relocated set for it. */
&& sym_map != &GL(dl_rtld_map)
#endif
&& !sym_map->l_relocated)
{
Elf64_FuncDesc *func = (Elf64_FuncDesc *) value;
opd.fd_func = func->fd_func + sym_map->l_addr;
opd.fd_toc = func->fd_toc + sym_map->l_addr;
opd.fd_aux = func->fd_aux;
value = (Elf64_Addr) &opd;
}
return ((Elf64_Addr (*) (void)) value) ();
}
/* Perform the relocation specified by RELOC and SYM (which is fully
resolved). MAP is the object containing the reloc. */
auto inline void __attribute__ ((always_inline))
@ -550,11 +573,17 @@ elf_machine_rela (struct link_map *map,
if (__builtin_expect (r_type == R_PPC64_NONE, 0))
return;
/* We need SYM_MAP even in the absence of TLS, for elf_machine_fixup_plt. */
/* We need SYM_MAP even in the absence of TLS, for elf_machine_fixup_plt
and STT_GNU_IFUNC. */
struct link_map *sym_map = RESOLVE_MAP (&sym, version, r_type);
Elf64_Addr value = ((sym_map == NULL ? 0 : sym_map->l_addr + sym->st_value)
+ reloc->r_addend);
if (sym != NULL
&& __builtin_expect (ELFW(ST_TYPE) (sym->st_info) == STT_GNU_IFUNC, 0)
&& __builtin_expect (sym->st_shndx != SHN_UNDEF, 1))
value = resolve_ifunc (value, map, sym_map);
/* For relocs that don't edit code, return.
For relocs that might edit instructions, break from the switch. */
switch (r_type)
@ -564,6 +593,14 @@ elf_machine_rela (struct link_map *map,
*reloc_addr = value;
return;
case R_PPC64_IRELATIVE:
value = resolve_ifunc (value, map, sym_map);
*reloc_addr = value;
return;
case R_PPC64_JMP_IREL:
value = resolve_ifunc (value, map, sym_map);
/* Fall thru */
case R_PPC64_JMP_SLOT:
#ifdef RESOLVE_CONFLICT_FIND_MAP
elf_machine_plt_conflict (reloc_addr, value);