glibc/sysdeps/powerpc/dl-machine.h
Ulrich Drepper c0282c0642 Update.
2000-05-05  Ulrich Drepper  <drepper@redhat.com>

	* elf/dl-load.c (_dl_map_object_from_fd): Little of computation of
	parameter to mprotect and for variable assignments.

2000-05-03  Jes Sorensen  <jes@linuxcare.com>

	* sysdeps/generic/ldsodefs.h (LOOKUP_VALUE_ADDRESS): Check the
	validity of map before dereferencing it.

	* elf/dl-reloc.c (RESOLVE_MAP): Define.

2000-05-02  Jes Sorensen  <jes@linuxcare.com>

	* elf/dl-runtime.c (fixup): Add the value returned in the symbol
	lookup to the arguments to elf_machine_fixup_plt().

	* sysdeps/ia64/dl-machine.h (elf_machine_fixup_plt): Add Link_map
	of the symbol being resolved to input argument list and make the
	function return the pointer to the reloc.

	* sysdeps/alpha/dl-machine.h (elf_machine_fixup_plt): Change
	return valuie to lookup_t and return the value.
	* sysdeps/arm/dl-machine.h (elf_machine_fixup_plt): Likewise.
	* sysdeps/generic/dl-machine.h (elf_machine_fixup_plt): Likewise.
	* sysdeps/i386/dl-machine.h (elf_machine_fixup_plt): Likewise.
	* sysdeps/m68k/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/powerpc/dl-machine.h (elf_machine_fixup_plt): Likewise.
	Make it an inline function returning value after calling
	__elf_machine_fixup_plt().

	* elf/dl-sym.c (_dl_vsym): Use DL_SYMBOL_ADDRESS() to obtain the
	symbol address.

	* elf/dl-symbol.c (_dl_symbol_value): Use LOOKUP_VALUE_ADDRESS to
	obtain the symbol address.

	* sysdeps/generic/ldsodefs.h: Add generic DL_SYMBOL_ADDRESS() macro
	depending on the definition of ELF_FUNCTION_PTR_IS_SPECIAL.

	* sysdeps/ia64/dl-machine.h: Add DL_SYMBOL_ADDRESS() macro calling
	_dl_symbol_address() - this way DL_SYMBOL_ADDRESS() turns into an
	inline on non ia64.

2000-04-28  Jes Sorensen  <jes@linuxcare.com>

	* elf/dl-runtime.c (fixup): Use the portable macros to get the
	symbol address of an object.

	* elf/dl-runtime.c (fixup-profile): Use the portable macros to get
	the symbol address of an object.

	* elf/dl-libc.c (struct do_dlsym_args): Change loadbase to a lookup_t.
	* elf/dl-lookup.c (_dl_lookup_symbol): Likewise.
	(_dl_lookup_symbol_skip): Likewise.
	(_dl_lookup_versioned_symbol): Likewise.
	(_dl_lookup_versioned_symbol_skip): Likewise.

2000-04-27  Jes Sorensen  <jes@linuxcare.com>

	* elf/rtld.c (_dl_start): Get the function pointer return address
	via _dl_start_address for architectures that need a function
	pointer descriptor rather than just a pointer (ia64).

	* sysdeps/generic/dl-lookupcfg.h: New file.
	* sysdeps/ia64/dl-lookupcfg.h: New file.
	* sysdeps/ia64/dl-machine.h: New file.
	* sysdeps/ia64/dl-symaddr.c: New file.
	* sysdeps/ia64/dl-fptr.c: New file.

	* elf/elf.h: Add IA-64 specific definitions.
2000-05-05 07:15:29 +00:00

351 lines
11 KiB
C

/* Machine-dependent ELF dynamic relocation inline functions. PowerPC version.
Copyright (C) 1995, 96, 97, 98, 99, 2000 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,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#ifndef dl_machine_h
#define dl_machine_h
#define ELF_MACHINE_NAME "powerpc"
#include <assert.h>
/* Return nonzero iff E_MACHINE is compatible with the running host. */
static inline int
elf_machine_matches_host (Elf32_Half e_machine)
{
return e_machine == EM_PPC;
}
/* Return the link-time address of _DYNAMIC, stored as
the first value in the GOT. */
static inline Elf32_Addr
elf_machine_dynamic (void)
{
Elf32_Addr *got;
asm (" bl _GLOBAL_OFFSET_TABLE_-4@local"
: "=l"(got));
return *got;
}
/* Return the run-time load address of the shared object. */
static inline Elf32_Addr
elf_machine_load_address (void)
{
unsigned int *got;
unsigned int *branchaddr;
/* This is much harder than you'd expect. Possibly I'm missing something.
The 'obvious' way:
Apparently, "bcl 20,31,$+4" is what should be used to load LR
with the address of the next instruction.
I think this is so that machines that do bl/blr pairing don't
get confused.
asm ("bcl 20,31,0f ;"
"0: mflr 0 ;"
"lis %0,0b@ha;"
"addi %0,%0,0b@l;"
"subf %0,%0,0"
: "=b" (addr) : : "r0", "lr");
doesn't work, because the linker doesn't have to (and in fact doesn't)
update the @ha and @l references; the loader (which runs after this
code) will do that.
Instead, we use the following trick:
The linker puts the _link-time_ address of _DYNAMIC at the first
word in the GOT. We could branch to that address, if we wanted,
by using an @local reloc; the linker works this out, so it's safe
to use now. We can't, of course, actually branch there, because
we'd cause an illegal instruction exception; so we need to compute
the address ourselves. That gives us the following code: */
/* Get address of the 'b _DYNAMIC@local'... */
asm ("bl 0f ;"
"b _DYNAMIC@local;"
"0:"
: "=l"(branchaddr));
/* ... and the address of the GOT. */
asm (" bl _GLOBAL_OFFSET_TABLE_-4@local"
: "=l"(got));
/* So now work out the difference between where the branch actually points,
and the offset of that location in memory from the start of the file. */
return ((Elf32_Addr)branchaddr - *got
+ ((int)(*branchaddr << 6 & 0xffffff00) >> 6));
}
#define ELF_MACHINE_BEFORE_RTLD_RELOC(dynamic_info) /* nothing */
/* The PLT uses Elf32_Rela relocs. */
#define elf_machine_relplt elf_machine_rela
/* This code is used in dl-runtime.c to call the `fixup' function
and then redirect to the address it returns. It is called
from code built in the PLT by elf_machine_runtime_setup. */
#define ELF_MACHINE_RUNTIME_TRAMPOLINE asm ("\
.section \".text\"
.align 2
.globl _dl_runtime_resolve
.type _dl_runtime_resolve,@function
_dl_runtime_resolve:
# We need to save the registers used to pass parameters, and register 0,
# which is used by _mcount; the registers are saved in a stack frame.
stwu 1,-64(1)
stw 0,12(1)
stw 3,16(1)
stw 4,20(1)
# The code that calls this has put parameters for `fixup' in r12 and r11.
mr 3,12
stw 5,24(1)
mr 4,11
stw 6,28(1)
mflr 0
# We also need to save some of the condition register fields.
stw 7,32(1)
stw 0,48(1)
stw 8,36(1)
mfcr 0
stw 9,40(1)
stw 10,44(1)
stw 0,8(1)
bl fixup@local
# 'fixup' returns the address we want to branch to.
mtctr 3
# Put the registers back...
lwz 0,48(1)
lwz 10,44(1)
lwz 9,40(1)
mtlr 0
lwz 8,36(1)
lwz 0,8(1)
lwz 7,32(1)
lwz 6,28(1)
mtcrf 0xFF,0
lwz 5,24(1)
lwz 4,20(1)
lwz 3,16(1)
lwz 0,12(1)
# ...unwind the stack frame, and jump to the PLT entry we updated.
addi 1,1,64
bctr
.size _dl_runtime_resolve,.-_dl_runtime_resolve
.align 2
.globl _dl_prof_resolve
.type _dl_prof_resolve,@function
_dl_prof_resolve:
# We need to save the registers used to pass parameters, and register 0,
# which is used by _mcount; the registers are saved in a stack frame.
stwu 1,-64(1)
stw 0,12(1)
stw 3,16(1)
stw 4,20(1)
# The code that calls this has put parameters for `fixup' in r12 and r11.
mr 3,12
stw 5,24(1)
mr 4,11
stw 6,28(1)
mflr 5
# We also need to save some of the condition register fields.
stw 7,32(1)
stw 5,48(1)
stw 8,36(1)
mfcr 0
stw 9,40(1)
stw 10,44(1)
stw 0,8(1)
bl profile_fixup@local
# 'fixup' returns the address we want to branch to.
mtctr 3
# Put the registers back...
lwz 0,48(1)
lwz 10,44(1)
lwz 9,40(1)
mtlr 0
lwz 8,36(1)
lwz 0,8(1)
lwz 7,32(1)
lwz 6,28(1)
mtcrf 0xFF,0
lwz 5,24(1)
lwz 4,20(1)
lwz 3,16(1)
lwz 0,12(1)
# ...unwind the stack frame, and jump to the PLT entry we updated.
addi 1,1,64
bctr
.size _dl_prof_resolve,.-_dl_prof_resolve
# Undo '.section text'.
.previous
");
/* The actual _start code is in dl-start.S. Use a really
ugly bit of assembler to let dl-start.o see _dl_start. */
#define RTLD_START asm (".globl _dl_start");
/* Decide where a relocatable object should be loaded. */
extern ElfW(Addr)
__elf_preferred_address(struct link_map *loader, size_t maplength,
ElfW(Addr) mapstartpref);
#define ELF_PREFERRED_ADDRESS(loader, maplength, mapstartpref) \
__elf_preferred_address (loader, maplength, mapstartpref)
/* Nonzero iff TYPE should not be allowed to resolve to one of
the main executable's symbols, as for a COPY reloc. */
#define elf_machine_lookup_noexec_p(type) ((type) == R_PPC_COPY)
/* Nonzero iff TYPE describes relocation of a PLT entry, so
PLT entries should not be allowed to define the value. */
/* We never want to use a PLT entry as the destination of a
reloc, when what is being relocated is a branch. This is
partly for efficiency, but mostly so we avoid loops. */
#define elf_machine_lookup_noplt_p(type) ((type) == R_PPC_REL24 || \
(type) == R_PPC_ADDR24 || \
(type) == R_PPC_JMP_SLOT)
/* A reloc type used for ld.so cmdline arg lookups to reject PLT entries. */
#define ELF_MACHINE_JMP_SLOT R_PPC_JMP_SLOT
/* Nonzero iff TYPE describes relocation of a PLT entry, so
PLT entries should not be allowed to define the value. */
#define elf_machine_pltrel_p(type) ((type) == R_PPC_JMP_SLOT)
/* Set up the loaded object described by L so its unrelocated PLT
entries will jump to the on-demand fixup code in dl-runtime.c.
Also install a small trampoline to be used by entries that have
been relocated to an address too far away for a single branch. */
extern int __elf_machine_runtime_setup (struct link_map *map,
int lazy, int profile);
#define elf_machine_runtime_setup __elf_machine_runtime_setup
static inline void
elf_machine_lazy_rel (struct link_map *map,
Elf32_Addr l_addr, const Elf32_Rela *reloc)
{
/* elf_machine_runtime_setup handles this. */
}
/* 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);
static inline Elf32_Addr
elf_machine_fixup_plt (struct link_map *l, lookup_t t,
const Elf32_Rela *reloc,
Elf32_Addr *reloc_addr, Elf64_Addr value)
{
__elf_machine_fixup_plt (map, reloc, reloc_addr, finaladdr);
return value;
}
/* Return the final value of a plt relocation. */
static inline Elf32_Addr
elf_machine_plt_value (struct link_map *map, const Elf32_Rela *reloc,
Elf32_Addr value)
{
return value + reloc->r_addend;
}
#endif /* dl_machine_h */
#ifdef RESOLVE
/* Do the actual processing of a reloc, once its target address
has been determined. */
extern void __process_machine_rela (struct link_map *map,
const Elf32_Rela *reloc,
const Elf32_Sym *sym,
const Elf32_Sym *refsym,
Elf32_Addr *const reloc_addr,
Elf32_Addr finaladdr,
int rinfo);
/* Perform the relocation specified by RELOC and SYM (which is fully resolved).
LOADADDR is the load address of the object; INFO is an array indexed
by DT_* of the .dynamic section info. */
inline void
elf_machine_rela (struct link_map *map, const Elf32_Rela *reloc,
const Elf32_Sym *sym, const struct r_found_version *version,
Elf32_Addr *const reloc_addr)
{
const Elf32_Sym *const refsym = sym;
Elf32_Word loadbase, finaladdr;
const int rinfo = ELF32_R_TYPE (reloc->r_info);
if (rinfo == R_PPC_NONE)
return;
/* The condition on the next two lines is a hack around a bug in Solaris
tools on Sparc. It's not clear whether it should really be here at all,
but if not the binutils need to be changed. */
if (rinfo == R_PPC_RELATIVE
|| (sym->st_shndx != SHN_UNDEF
&& ELF32_ST_BIND (sym->st_info) == STB_LOCAL))
{
/* Has already been relocated. */
loadbase = map->l_addr;
finaladdr = loadbase + reloc->r_addend;
}
else
{
loadbase = (Elf32_Word) (char *) (RESOLVE (&sym, version,
ELF32_R_TYPE(reloc->r_info)));
if (sym == NULL)
{
/* Weak symbol that wasn't actually defined anywhere. */
assert(loadbase == 0);
finaladdr = reloc->r_addend;
}
else
finaladdr = (loadbase + (Elf32_Word) (char *) sym->st_value
+ reloc->r_addend);
}
/* 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
R_PPC_ADDR32, and 16% are R_PPC_JMP_SLOT (which this routine
wouldn't usually handle). As an bonus, doing this here allows
the switch statement in __process_machine_rela to work. */
if (rinfo == R_PPC_RELATIVE
|| rinfo == R_PPC_GLOB_DAT
|| rinfo == R_PPC_ADDR32)
{
*reloc_addr = finaladdr;
}
else
__process_machine_rela (map, reloc, sym, refsym,
reloc_addr, finaladdr, rinfo);
}
#define ELF_MACHINE_NO_REL 1
/* The SVR4 ABI specifies that the JMPREL relocs must be inside the
DT_RELA table. */
#define ELF_MACHINE_PLTREL_OVERLAP 1
#endif /* RESOLVE */