glibc/sysdeps/powerpc/powerpc64/dl-machine.c
Alan Modra 0572433b5b PowerPC64 ELFv2 PPC64_OPT_LOCALENTRY
ELFv2 functions with localentry:0 are those with a single entry point,
ie. global entry == local entry, that have no requirement on r2 or
r12 and guarantee r2 is unchanged on return.  Such an external
function can be called via the PLT without saving r2 or restoring it
on return, avoiding a common load-hit-store for small functions.

This patch implements the ld.so changes necessary for this
optimization.  ld.so needs to check that an optimized plt call
sequence is in fact calling a function implemented with localentry:0,
end emit a fatal error otherwise.

The elf/testobj6.c change is to stop "error while loading shared
libraries: expected localentry:0 `preload'" when running
elf/preloadtest, which we'd get otherwise.

	* elf/elf.h (PPC64_OPT_LOCALENTRY): Define.
	* sysdeps/alpha/dl-machine.h (elf_machine_fixup_plt): Add
	refsym and sym parameters.  Adjust callers.
	* sysdeps/aarch64/dl-machine.h (elf_machine_fixup_plt): Likewise.
	* sysdeps/arm/dl-machine.h (elf_machine_fixup_plt): Likewise.
	* sysdeps/generic/dl-machine.h (elf_machine_fixup_plt): Likewise.
	* sysdeps/hppa/dl-machine.h (elf_machine_fixup_plt): Likewise.
	* sysdeps/i386/dl-machine.h (elf_machine_fixup_plt): Likewise.
	* sysdeps/ia64/dl-machine.h (elf_machine_fixup_plt): Likewise.
	* sysdeps/m68k/dl-machine.h (elf_machine_fixup_plt): Likewise.
	* sysdeps/microblaze/dl-machine.h (elf_machine_fixup_plt): Likewise.
	* sysdeps/mips/dl-machine.h (elf_machine_fixup_plt): Likewise.
	* sysdeps/nios2/dl-machine.h (elf_machine_fixup_plt): Likewise.
	* sysdeps/powerpc/powerpc32/dl-machine.h (elf_machine_fixup_plt):
	Likewise.
	* sysdeps/s390/s390-32/dl-machine.h (elf_machine_fixup_plt): Likewise.
	* sysdeps/s390/s390-64/dl-machine.h (elf_machine_fixup_plt): Likewise.
	* sysdeps/sh/dl-machine.h (elf_machine_fixup_plt): Likewise.
	* sysdeps/sparc/sparc32/dl-machine.h (elf_machine_fixup_plt): Likewise.
	* sysdeps/sparc/sparc64/dl-machine.h (elf_machine_fixup_plt): Likewise.
	* sysdeps/tile/dl-machine.h (elf_machine_fixup_plt): Likewise.
	* sysdeps/x86_64/dl-machine.h (elf_machine_fixup_plt): Likewise.
	* sysdeps/powerpc/powerpc64/dl-machine.c (_dl_error_localentry): New.
	(_dl_reloc_overflow): Increase buffser size.  Formatting.
	* sysdeps/powerpc/powerpc64/dl-machine.h (ppc64_local_entry_offset):
	Delete reloc param, add refsym and sym.  Check optimized plt
	call stubs for localentry:0 functions.  Adjust callers.
	(elf_machine_fixup_plt, elf_machine_plt_conflict): Add refsym
	and sym parameters.  Adjust callers.
	(_dl_reloc_overflow): Move attribute.
	(_dl_error_localentry): Declare.
	* elf/dl-runtime.c (_dl_fixup): Save original sym.  Pass
	refsym and sym to elf_machine_fixup_plt.
	* elf/testobj6.c (preload): Call printf.
2017-06-14 10:47:25 +09:30

64 lines
1.9 KiB
C

/* Machine-dependent ELF dynamic relocation functions. PowerPC64 version.
Copyright (C) 1995-2017 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 Library General Public License as
published by the Free Software Foundation; either version 2 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, see <http://www.gnu.org/licenses/>. */
#include <string.h>
#include <unistd.h>
#include <ldsodefs.h>
#include <_itoa.h>
#include <dl-machine.h>
void
_dl_reloc_overflow (struct link_map *map,
const char *name,
Elf64_Addr *const reloc_addr,
const Elf64_Sym *refsym)
{
char buffer[1024];
char *t;
t = stpcpy (buffer, name);
t = stpcpy (t, " reloc at 0x");
_itoa_word ((unsigned long) reloc_addr, t, 16, 0);
if (refsym)
{
const char *strtab;
strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);
t = stpcpy (t, " for symbol `");
t = stpcpy (t, strtab + refsym->st_name);
t = stpcpy (t, "'");
}
t = stpcpy (t, " out of range");
_dl_signal_error (0, map->l_name, NULL, buffer);
}
#if _CALL_ELF == 2
void
_dl_error_localentry (struct link_map *map, const Elf64_Sym *refsym)
{
char buffer[1024];
char *t;
const char *strtab;
strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);
t = stpcpy (buffer, "expected localentry:0 `");
t = stpcpy (t, strtab + refsym->st_name);
t = stpcpy (t, "'");
_dl_signal_error (0, map->l_name, NULL, buffer);
}
#endif