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1998-08-09  Geoff Keating  <geoffk@ozemail.com.au>

	* sysdeps/powerpc/Makefile [subdir=elf]: Add new files split out of
	dl-machine.h.
	* sysdeps/powerpc/dl-machine.c: New file.
	* sysdeps/powerpc/dl-machine.h: Move much stuff into separate
	files.  Revise ELF_PREFERRED_ADDRESS to take account of
	the new mapping information (fixes bug involving huge bloated
	web browser).  Set ELF_MACHINE_PLTREL_OVERLAP.
	* sysdeps/powerpc/dl-start.S: New file.

	* elf/dl-load.c (_dl_map_object_from_fd): Initialise l_map_start,
	l_map_end.
	* elf/do-rel.h: Call elf_machine_rel only once (to save space).
	* elf/dynamic-link.h: Allow PLT relocs to be in the middle of the
	others.  Call elf_dynamic_do_##reloc only once (to save even more
	space).
	* elf/link.h: Add new members l_map_start and l_map_end to keep
	track of the memory map.
	* elf/rtld.c (_dl_start): Initialise l_map_start for ld.so and
	the executable.

1998-09-01 11:53  Ulrich Drepper  <drepper@cygnus.com>

	* debug/Makefile (catchsegv): We need not rewrite SOVER anymore.
	Reported by Andreas Jaeger.

	* posix/glob.h: Use __size_t instead of size_t in definitions and
	make sure this is defined.

	* manual/locale.texi: Almost complete rewrite.  Document more functions
This commit is contained in:
Ulrich Drepper 1998-09-01 14:31:49 +00:00
parent 85c165befc
commit 052b6a6c94
16 changed files with 848 additions and 527 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

32
ChangeLog
View File

@ -1,6 +1,36 @@
1998-08-09 Geoff Keating <geoffk@ozemail.com.au>
* sysdeps/powerpc/Makefile [subdir=elf]: Add new files split out of
dl-machine.h.
* sysdeps/powerpc/dl-machine.c: New file.
* sysdeps/powerpc/dl-machine.h: Move much stuff into separate
files. Revise ELF_PREFERRED_ADDRESS to take account of
the new mapping information (fixes bug involving huge bloated
web browser). Set ELF_MACHINE_PLTREL_OVERLAP.
* sysdeps/powerpc/dl-start.S: New file.
* elf/dl-load.c (_dl_map_object_from_fd): Initialise l_map_start,
l_map_end.
* elf/do-rel.h: Call elf_machine_rel only once (to save space).
* elf/dynamic-link.h: Allow PLT relocs to be in the middle of the
others. Call elf_dynamic_do_##reloc only once (to save even more
space).
* elf/link.h: Add new members l_map_start and l_map_end to keep
track of the memory map.
* elf/rtld.c (_dl_start): Initialise l_map_start for ld.so and
the executable.
1998-09-01 11:53 Ulrich Drepper <drepper@cygnus.com>
* debug/Makefile (catchsegv): We need not rewrite SOVER anymore.
Reported by Andreas Jaeger.
* posix/glob.h: Use __size_t instead of size_t in definitions and
make sure this is defined.
1998-09-01 10:34 Ulrich Drepper <drepper@cygnus.com>
* manual/locale.texi: Almost compelte rewrite. Document more functions
* manual/locale.texi: Almost complete rewrite. Document more functions
and functionality.
* manual/arith.texi: Correct reference.
* manual/string.texi: Pretty printing.

3
debug/Makefile
View File

@ -44,8 +44,7 @@ include ../Rules
$(objpfx)catchsegv: catchsegv.sh $(common-objpfx)soversions.mk \
$(common-objpfx)config.make
sed -e 's|@VERSION@|$(version)|' -e 's|@SLIB@|$(slibdir)|' \
-e 's|@SOVER@|$(libSegFault.so-version)|' $< > $@.new
sed -e 's|@VERSION@|$(version)|' -e 's|@SLIB@|$(slibdir)|' $< > $@.new
chmod 555 $@.new
mv -f $@.new $@

9
elf/dl-load.c
View File

@ -848,6 +848,11 @@ _dl_map_object_from_fd (char *name, int fd, char *realname,
__mprotect ((caddr_t) (l->l_addr + c->mapend),
loadcmds[nloadcmds - 1].allocend - c->mapend,
0);
/* Remember which part of the address space this object uses. */
l->l_map_start = c->mapstart + l->l_addr;
l->l_map_end = l->l_map_start + maplength;
goto postmap;
}
else
@ -857,6 +862,10 @@ _dl_map_object_from_fd (char *name, int fd, char *realname,
ELF_FIXED_ADDRESS (loader, c->mapstart);
}
/* Remember which part of the address space this object uses. */
l->l_map_start = c->mapstart + l->l_addr;
l->l_map_end = l->l_map_start + maplength;
while (c < &loadcmds[nloadcmds])
{
if (c->mapend > c->mapstart)

91
elf/dynamic-link.h
View File

@ -83,60 +83,75 @@ elf_get_dynamic_info (ElfW(Dyn) *dyn,
#ifdef ELF_MACHINE_PLTREL_OVERLAP
#define _ELF_DYNAMIC_DO_RELOC(RELOC, reloc, map, lazy) \
do { \
ElfW(Addr) r_addr, r_size, p_addr, p_size; \
struct { ElfW(Addr) start, size; int lazy; } ranges[3]; \
int ranges_index; \
\
ranges[0].lazy = ranges[2].lazy = 0; \
ranges[1].lazy = 1; \
ranges[0].size = ranges[1].size = ranges[2].size = 0; \
\
if ((map)->l_info[DT_##RELOC]) \
{ \
r_addr = (map)->l_info[DT_##RELOC]->d_un.d_ptr; \
r_size = (map)->l_info[DT_##RELOC##SZ]->d_un.d_val; \
if ((map)->l_info[DT_PLTREL] && \
(map)->l_info[DT_PLTREL]->d_un.d_val == DT_##RELOC) \
{ \
p_addr = (map)->l_info[DT_JMPREL]->d_un.d_ptr; \
p_size = (map)->l_info[DT_PLTRELSZ]->d_un.d_val; \
if (r_addr <= p_addr && r_addr+r_size > p_addr) \
{ \
ElfW(Addr) r2_addr, r2_size; \
r2_addr = p_addr + p_size; \
if (r2_addr < r_addr + r_size) \
{ \
r2_size = r_addr + r_size - r2_addr; \
elf_dynamic_do_##reloc ((map), r2_addr, r2_size, 0); \
} \
r_size = p_addr - r_addr; \
} \
} \
\
elf_dynamic_do_##reloc ((map), r_addr, r_size, 0); \
if (p_addr) \
elf_dynamic_do_##reloc ((map), p_addr, p_size, (lazy)); \
ranges[0].start = (map)->l_info[DT_##RELOC]->d_un.d_ptr; \
ranges[0].size = (map)->l_info[DT_##RELOC##SZ]->d_un.d_val; \
} \
else if ((map)->l_info[DT_PLTREL] && \
(map)->l_info[DT_PLTREL]->d_un.d_val == DT_##RELOC) \
\
if ((lazy) \
&& (map)->l_info[DT_PLTREL] \
&& (map)->l_info[DT_PLTREL]->d_un.d_val == DT_##RELOC) \
{ \
p_addr = (map)->l_info[DT_JMPREL]->d_un.d_ptr; \
p_size = (map)->l_info[DT_PLTRELSZ]->d_un.d_val; \
\
elf_dynamic_do_##reloc ((map), p_addr, p_size, (lazy)); \
ranges[1].start = (map)->l_info[DT_JMPREL]->d_un.d_ptr; \
ranges[1].size = (map)->l_info[DT_PLTRELSZ]->d_un.d_val; \
ranges[2].start = ranges[1].start + ranges[1].size; \
ranges[2].size = ranges[0].start + ranges[0].size - ranges[2].start; \
ranges[0].size = ranges[1].start - ranges[0].start; \
} \
\
for (ranges_index = 0; ranges_index < 3; ++ranges_index) \
elf_dynamic_do_##reloc ((map), \
ranges[ranges_index].start, \
ranges[ranges_index].size, \
ranges[ranges_index].lazy); \
} while (0)
#else
#define _ELF_DYNAMIC_DO_RELOC(RELOC, reloc, map, lazy) \
do { \
struct { ElfW(Addr) start, size; int lazy; } ranges[2]; \
int ranges_index; \
ranges[0].lazy = 0; \
ranges[1].lazy = 1; \
ranges[0].size = ranges[1].size = 0; \
ranges[0].start = 0; \
\
if ((map)->l_info[DT_##RELOC]) \
{ \
ElfW(Addr) r_addr, r_size; \
r_addr = (map)->l_info[DT_##RELOC]->d_un.d_ptr; \
r_size = (map)->l_info[DT_##RELOC##SZ]->d_un.d_val; \
elf_dynamic_do_##reloc ((map), r_addr, r_size, 0); \
ranges[0].start = (map)->l_info[DT_##RELOC]->d_un.d_ptr; \
ranges[0].size = (map)->l_info[DT_##RELOC##SZ]->d_un.d_val; \
} \
if ((map)->l_info[DT_PLTREL] && \
(map)->l_info[DT_PLTREL]->d_un.d_val == DT_##RELOC) \
{ \
ElfW(Addr) p_addr, p_size; \
p_addr = (map)->l_info[DT_JMPREL]->d_un.d_ptr; \
p_size = (map)->l_info[DT_PLTRELSZ]->d_un.d_val; \
elf_dynamic_do_##reloc ((map), p_addr, p_size, (lazy)); \
ElfW(Addr) start = (map)->l_info[DT_JMPREL]->d_un.d_ptr; \
\
if (lazy \
/* This test does not only detect whether the relocation \
sections are in the right order, it also checks whether \
there is a DT_REL/DT_RELA section. */ \
|| ranges[0].start + ranges[0].size != start) \
{ \
ranges[1].start = start; \
ranges[1].size = (map)->l_info[DT_PLTRELSZ]->d_un.d_val; \
} \
else \
/* Combine processing the sections. */ \
ranges[0].size += (map)->l_info[DT_PLTRELSZ]->d_un.d_val; \
} \
\
for (ranges_index = 0; ranges_index < 2; ++ranges_index) \
elf_dynamic_do_##reloc ((map), \
ranges[ranges_index].start, \
ranges[ranges_index].size, \
ranges[ranges_index].lazy); \
} while (0)
#endif

4
elf/link.h
View File

@ -164,6 +164,10 @@ struct link_map
/* String specifying the path where this object was found. */
const char *l_origin;
/* Start and finish of memory map for this object. l_map_start
need not be the same as l_addr. */
ElfW(Addr) l_map_start, l_map_end;
};
#endif /* link.h */

18
elf/rtld.c
View File

@ -165,6 +165,10 @@ _dl_start (void *arg)
_dl_rtld_map.l_info[DT_RPATH]->d_un.d_val);
}
/* Don't bother trying to work out how ld.so is mapped in memory. */
_dl_rtld_map.l_map_start = ~0;
_dl_rtld_map.l_map_end = ~0;
/* Call the OS-dependent function to set up life so we can do things like
file access. It will call `dl_main' (below) to do all the real work
of the dynamic linker, and then unwind our frame and run the user
@ -432,6 +436,11 @@ of this helper program; chances are you did not intend to run this program.\n\
information for the program. */
}
/* It is not safe to load stuff after the main program. */
main_map->l_map_end = ~0;
/* Perhaps the executable has no PT_LOAD header entries at all. */
main_map->l_map_start = ~0;
/* Scan the program header table for the dynamic section. */
for (ph = phdr; ph < &phdr[phent]; ++ph)
switch (ph->p_type)
@ -474,6 +483,15 @@ of this helper program; chances are you did not intend to run this program.\n\
has_interp = 1;
break;
case PT_LOAD:
/* Remember where the main program starts in memory. */
{
ElfW(Addr) mapstart;
mapstart = main_map->l_addr + (ph->p_vaddr & ~(ph->p_align - 1));
if (main_map->l_map_start > mapstart)
main_map->l_map_start = mapstart;
}
break;
}
if (! _dl_rtld_map.l_libname && _dl_rtld_map.l_name)
{

5
manual/examples/argp-ex1.c
View File

@ -1,5 +1,10 @@
/* Argp example #1 -- a minimal program using argp */
/* This is (probably) the smallest possible program that
uses argp. It won't do much except give an error
messages and exit when there are any arguments, and print
a (rather pointless) messages for --help. */
#include <argp.h>
int main (int argc, char **argv)

21
manual/examples/argp-ex2.c
View File

@ -1,11 +1,30 @@
/* Argp example #2 -- a pretty minimal program using argp */
/* This program doesn't use any options or arguments, but uses
argp to be compliant with the GNU standard command line
format.
In addition to making sure no arguments are given, and
implementing a --help option, this example will have a
--version option, and will put the given documentation string
and bug address in the --help output, as per GNU standards.
The variable ARGP contains the argument parser specification;
adding fields to this structure is the way most parameters are
passed to argp_parse (the first three fields are usually used,
but not in this small program). There are also two global
variables that argp knows about defined here,
ARGP_PROGRAM_VERSION and ARGP_PROGRAM_BUG_ADDRESS (they are
global variables becuase they will almost always be constant
for a given program, even if it uses different argument
parsers for various tasks). */
#include <argp.h>
const char *argp_program_version =
"argp-ex2 1.0";
const char *argp_program_bug_address =
"<bug-gnu-utils@@prep.ai.mit.edu>";
"<bug-gnu-utils@@gnu.org>";
/* Program documentation. */
static char doc[] =

54
manual/examples/argp-ex3.c
View File

@ -1,11 +1,63 @@
/* Argp example #3 -- a program with options and arguments using argp */
/* This program uses the same features as example 2, and uses options and
arguments.
We now use the first four fields in ARGP, so here's a description of them:
OPTIONS -- A pointer to a vector of struct argp_option (see below)
PARSER -- A function to parse a single option, called by argp
ARGS_DOC -- A string describing how the non-option arguments should look
DOC -- A descriptive string about this program; if it contains a
vertical tab character (\v), the part after it will be
printed *following* the options
The function PARSER takes the following arguments:
KEY -- An integer specifying which option this is (taken
from the KEY field in each struct argp_option), or
a special key specifying something else; the only
special keys we use here are ARGP_KEY_ARG, meaning
a non-option argument, and ARGP_KEY_END, meaning
that all argumens have been parsed
ARG -- For an option KEY, the string value of its
argument, or NULL if it has none
STATE-- A pointer to a struct argp_state, containing
various useful information about the parsing state; used here
are the INPUT field, which reflects the INPUT argument to
argp_parse, and the ARG_NUM field, which is the number of the
current non-option argument being parsed
It should return either 0, meaning success, ARGP_ERR_UNKNOWN, meaning the
given KEY wasn't recognized, or an errno value indicating some other
error.
Note that in this example, main uses a structure to communicate with the
parse_opt function, a pointer to which it passes in the INPUT argument to
argp_parse. Of course, it's also possible to use global variables
instead, but this is somewhat more flexible.
The OPTIONS field contains a pointer to a vector of struct argp_option's;
that structure has the following fields (if you assign your option
structures using array initialization like this example, unspecified
fields will be defaulted to 0, and need not be specified):
NAME -- The name of this option's long option (may be zero)
KEY -- The KEY to pass to the PARSER function when parsing this option,
*and* the name of this option's short option, if it is a
printable ascii character
ARG -- The name of this option's argument, if any
FLAGS -- Flags describing this option; some of them are:
OPTION_ARG_OPTIONAL -- The argument to this option is optional
OPTION_ALIAS -- This option is an alias for the
previous option
OPTION_HIDDEN -- Don't show this option in --help output
DOC -- A documentation string for this option, shown in --help output
An options vector should be terminated by an option with all fields zero. */
#include <argp.h>
const char *argp_program_version =
"argp-ex3 1.0";
const char *argp_program_bug_address =
"<bug-gnu-utils@@prep.ai.mit.edu>";
"<bug-gnu-utils@@gnu.org>";
/* Program documentation. */
static char doc[] =

23
manual/examples/argp-ex4.c
View File

@ -1,5 +1,28 @@
/* Argp example #4 -- a program with somewhat more complicated options */
/* This program uses the same features as example 3, but has more
options, and somewhat more structure in the -help output. It
also shows how you can `steal' the remainder of the input
arguments past a certain point, for programs that accept a
list of items. It also shows the special argp KEY value
ARGP_KEY_NO_ARGS, which is only given if no non-option
arguments were supplied to the program.
For structuring the help output, two features are used,
*headers* which are entries in the options vector with the
first four fields being zero, and a two part documentation
string (in the variable DOC), which allows documentation both
before and after the options; the two parts of DOC are
separated by a vertical-tab character ('\v', or '\013'). By
convention, the documentation before the options is just a
short string saying what the program does, and that afterwards
is longer, describing the behavior in more detail. All
documentation strings are automatically filled for output,
although newlines may be included to force a line break at a
particular point. All documenation strings are also passed to
the `gettext' function, for possible translation into the
current locale. */
#include <stdlib.h>
#include <error.h>
#include <argp.h>

6
manual/startup.texi
View File

@ -82,7 +82,7 @@ allow this three-argument form, so to be portable it is best to write
* Parsing Program Arguments:: Ways to parse program options and arguments.
@end menu
@node Argument Syntax
@node Argument Syntax, Parsing Program Arguments, , Program Arguments
@subsection Program Argument Syntax Conventions
@cindex program argument syntax
@cindex syntax, for program arguments
@ -154,7 +154,7 @@ accept an argument that is itself optional.
Eventually, the GNU system will provide completion for long option names
in the shell.
@node Parsing Program Arguments
@node Parsing Program Arguments, , Argument Syntax, Program Arguments
@subsection Parsing Program Arguments
@cindex program arguments, parsing
@ -188,7 +188,7 @@ it does more of the dirty work for you.
@node Suboptions, Suboptions Example, Argp, Parsing Program Arguments
@c This is a @section so that it's at the same level as getopt and argp
@section Parsing of Suboptions
@subsubsection Parsing of Suboptions
Having a single level of options is sometimes not enough. There might
be too many options which have to be available or a set of options is

23
posix/glob.h
View File

@ -43,6 +43,21 @@ extern "C" {
# define __ptr_t char *
#endif /* C++ or ANSI C. */
/* We need `size_t' for the following definitions. */
#ifndef __size_t
# if defined __GNUC__ && __GNUC__ >= 2
typedef __SIZE_TYPE__ __size_t;
# else
/* This is a guess. */
typedef unsigned long int __size_t;
# endif
#else
/* The GNU CC stddef.h version defines __size_t as empty. We need a real
definition. */
# undef __size_t
# define __size_t size_t
#endif
/* Bits set in the FLAGS argument to `glob'. */
#define GLOB_ERR (1 << 0)/* Return on read errors. */
#define GLOB_MARK (1 << 1)/* Append a slash to each name. */
@ -90,9 +105,9 @@ struct stat;
#endif
typedef struct
{
size_t gl_pathc; /* Count of paths matched by the pattern. */
__size_t gl_pathc; /* Count of paths matched by the pattern. */
char **gl_pathv; /* List of matched pathnames. */
size_t gl_offs; /* Slots to reserve in `gl_pathv'. */
__size_t gl_offs; /* Slots to reserve in `gl_pathv'. */
int gl_flags; /* Set to FLAGS, maybe | GLOB_MAGCHAR. */
/* If the GLOB_ALTDIRFUNC flag is set, the following functions
@ -108,9 +123,9 @@ typedef struct
struct stat64;
typedef struct
{
size_t gl_pathc;
__size_t gl_pathc;
char **gl_pathv;
size_t gl_offs;
__size_t gl_offs;
int gl_flags;
/* If the GLOB_ALTDIRFUNC flag is set, the following functions

5
sysdeps/powerpc/Makefile
View File

@ -28,3 +28,8 @@ endif
ifeq ($(subdir),string)
CFLAGS-memcmp.c += -Wno-uninitialized
endif
ifeq ($(subdir),elf)
dl-routines += dl-machine
rtld-routines += dl-machine dl-start
endif

442
sysdeps/powerpc/dl-machine.c Normal file
View File

@ -0,0 +1,442 @@
/* Machine-dependent ELF dynamic relocation functions. PowerPC version.
Copyright (C) 1995, 1996, 1997, 1998 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. */
#include <unistd.h>
#include <string.h>
#include <sys/param.h>
#include <link.h>
#include <dl-machine.h>
#include <elf/ldsodefs.h>
#include <elf/dynamic-link.h>
/* Because ld.so is now versioned, these functions can be in their own file;
no relocations need to be done to call them.
Of course, if ld.so is not versioned... */
#if !(DO_VERSIONING - 0)
#error This will not work with versioning turned off, sorry.
#endif
/* stuff for the PLT */
#define PLT_INITIAL_ENTRY_WORDS 18
#define PLT_LONGBRANCH_ENTRY_WORDS 10
#define PLT_DOUBLE_SIZE (1<<13)
#define PLT_ENTRY_START_WORDS(entry_number) \
(PLT_INITIAL_ENTRY_WORDS + (entry_number)*2 + \
((entry_number) > PLT_DOUBLE_SIZE ? \
((entry_number) - PLT_DOUBLE_SIZE)*2 : \
0))
#define PLT_DATA_START_WORDS(num_entries) PLT_ENTRY_START_WORDS(num_entries)
#define OPCODE_ADDI(rd,ra,simm) \
(0x38000000 | (rd) << 21 | (ra) << 16 | (simm) & 0xffff)
#define OPCODE_ADDIS(rd,ra,simm) \
(0x3c000000 | (rd) << 21 | (ra) << 16 | (simm) & 0xffff)
#define OPCODE_ADD(rd,ra,rb) \
(0x7c000214 | (rd) << 21 | (ra) << 16 | (rb) << 11)
#define OPCODE_B(target) (0x48000000 | (target) & 0x03fffffc)
#define OPCODE_BA(target) (0x48000002 | (target) & 0x03fffffc)
#define OPCODE_BCTR() 0x4e800420
#define OPCODE_LWZ(rd,d,ra) \
(0x80000000 | (rd) << 21 | (ra) << 16 | (d) & 0xffff)
#define OPCODE_MTCTR(rd) (0x7C0903A6 | (rd) << 21)
#define OPCODE_RLWINM(ra,rs,sh,mb,me) \
(0x54000000 | (rs) << 21 | (ra) << 16 | (sh) << 11 | (mb) << 6 | (me) << 1)
#define OPCODE_LI(rd,simm) OPCODE_ADDI(rd,0,simm)
#define OPCODE_SLWI(ra,rs,sh) OPCODE_RLWINM(ra,rs,sh,0,31-sh)
#define PPC_DCBST(where) asm volatile ("dcbst 0,%0" : : "r"(where))
#define PPC_SYNC asm volatile ("sync")
#define PPC_ISYNC asm volatile ("sync; isync")
#define PPC_ICBI(where) asm volatile ("icbi 0,%0" : : "r"(where))
#define PPC_DIE asm volatile ("tweq 0,0")
/* Use this when you've modified some code, but it won't be in the
instruction fetch queue (or when it doesn't matter if it is). */
#define MODIFIED_CODE_NOQUEUE(where) \
do { PPC_DCBST(where); PPC_SYNC; PPC_ICBI(where); } while (0)
/* Use this when it might be in the instruction queue. */
#define MODIFIED_CODE(where) \
do { PPC_DCBST(where); PPC_SYNC; PPC_ICBI(where); PPC_ISYNC; } while (0)
/* The idea here is that to conform to the ABI, we are supposed to try
to load dynamic objects between 0x10000 (we actually use 0x40000 as
the lower bound, to increase the chance of a memory reference from
a null pointer giving a segfault) and the program's load address;
this may allow us to use a branch instruction in the PLT rather
than a computed jump. The address is only used as a preference for
mmap, so if we get it wrong the worst that happens is that it gets
mapped somewhere else. */
ElfW(Addr)
__elf_preferred_address(struct link_map *loader, size_t maplength,
ElfW(Addr) mapstartpref)
{
ElfW(Addr) low, high;
struct link_map *l;
/* If the object has a preference, load it there! */
if (mapstartpref != 0)
return mapstartpref;
/* Otherwise, quickly look for a suitable gap between 0x3FFFF and
0x70000000. 0x3FFFF is so that references off NULL pointers will
cause a segfault, 0x70000000 is just paranoia (it should always
be superceded by the program's load address). */
low = 0x0003FFFF;
high = 0x70000000;
for (l = _dl_loaded; l; l = l->l_next)
{
ElfW(Addr) mapstart, mapend;
mapstart = l->l_map_start & ~(_dl_pagesize - 1);
mapend = l->l_map_end | (_dl_pagesize - 1);
assert (mapend > mapstart);
if (mapend >= high && high >= mapstart)
high = mapstart;
else if (mapend >= low && low >= mapstart)
low = mapend;
else if (high >= mapend && mapstart >= low)
{
if (high - mapend >= mapstart - low)
low = mapend;
else
high = mapstart;
}
}
high -= 0x10000; /* Allow some room between objects. */
maplength = (maplength | (_dl_pagesize-1)) + 1;
if (high <= low || high - low < maplength )
return 0;
return high - maplength; /* Both high and maplength are page-aligned. */
}
/* 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. */
/* A PLT entry does one of three things:
(i) Jumps to the actual routine. Such entries are set up above, in
elf_machine_rela.
(ii) Jumps to the actual routine via glue at the start of the PLT.
We do this by putting the address of the routine in space
allocated at the end of the PLT, and when the PLT entry is
called we load the offset of that word (from the start of the
space) into r11, then call the glue, which loads the word and
branches to that address. These entries are set up in
elf_machine_rela, but the glue is set up here.
(iii) Loads the index of this PLT entry (we count the double-size
entries as one entry for this purpose) into r11, then
branches to code at the start of the PLT. This code then
calls `fixup', in dl-runtime.c, via the glue in the macro
ELF_MACHINE_RUNTIME_TRAMPOLINE, which resets the PLT entry to
be one of the above two types. These entries are set up here. */
int
__elf_machine_runtime_setup (struct link_map *map, int lazy, int profile)
{
if (map->l_info[DT_JMPREL])
{
Elf32_Word i;
/* Fill in the PLT. Its initial contents are directed to a
function earlier in the PLT which arranges for the dynamic
linker to be called back. */
Elf32_Word *plt = (Elf32_Word *) ((char *) map->l_addr
+ map->l_info[DT_PLTGOT]->d_un.d_val);
Elf32_Word num_plt_entries = (map->l_info[DT_PLTRELSZ]->d_un.d_val
/ sizeof (Elf32_Rela));
Elf32_Word rel_offset_words = PLT_DATA_START_WORDS (num_plt_entries);
Elf32_Word size_modified;
extern void _dl_runtime_resolve (void);
extern void _dl_prof_resolve (void);
Elf32_Word dlrr;
dlrr = (Elf32_Word)(char *)(profile
? _dl_prof_resolve
: _dl_runtime_resolve);
if (lazy)
for (i = 0; i < num_plt_entries; i++)
{
Elf32_Word offset = PLT_ENTRY_START_WORDS (i);
if (i >= PLT_DOUBLE_SIZE)
{
plt[offset ] = OPCODE_LI (11, i * 4);
plt[offset+1] = OPCODE_ADDIS (11, 11, (i * 4 + 0x8000) >> 16);
plt[offset+2] = OPCODE_B (-(4 * (offset + 2)));
}
else
{
plt[offset ] = OPCODE_LI (11, i * 4);
plt[offset+1] = OPCODE_B (-(4 * (offset + 1)));
}
}
/* Multiply index of entry by 3 (in r11). */
plt[0] = OPCODE_SLWI (12, 11, 1);
plt[1] = OPCODE_ADD (11, 12, 11);
if (dlrr <= 0x01fffffc || dlrr >= 0xfe000000)
{
/* Load address of link map in r12. */
plt[2] = OPCODE_LI (12, (Elf32_Word) (char *) map);
plt[3] = OPCODE_ADDIS (12, 12, (((Elf32_Word) (char *) map
+ 0x8000) >> 16));
/* Call _dl_runtime_resolve. */
plt[4] = OPCODE_BA (dlrr);
}
else
{
/* Get address of _dl_runtime_resolve in CTR. */
plt[2] = OPCODE_LI (12, dlrr);
plt[3] = OPCODE_ADDIS (12, 12, (dlrr + 0x8000) >> 16);
plt[4] = OPCODE_MTCTR (12);
/* Load address of link map in r12. */
plt[5] = OPCODE_LI (12, (Elf32_Word) (char *) map);
plt[6] = OPCODE_ADDIS (12, 12, (((Elf32_Word) (char *) map
+ 0x8000) >> 16));
/* Call _dl_runtime_resolve. */
plt[7] = OPCODE_BCTR ();
}
/* Convert the index in r11 into an actual address, and get the
word at that address. */
plt[PLT_LONGBRANCH_ENTRY_WORDS] =
OPCODE_ADDIS (11, 11, (((Elf32_Word) (char*) (plt + rel_offset_words)
+ 0x8000) >> 16));
plt[PLT_LONGBRANCH_ENTRY_WORDS+1] =
OPCODE_LWZ (11, (Elf32_Word) (char*) (plt+rel_offset_words), 11);
/* Call the procedure at that address. */
plt[PLT_LONGBRANCH_ENTRY_WORDS+2] = OPCODE_MTCTR (11);
plt[PLT_LONGBRANCH_ENTRY_WORDS+3] = OPCODE_BCTR ();
/* Now, we've modified code (quite a lot of code, possibly). We
need to write the changes from the data cache to a
second-level unified cache, then make sure that stale data in
the instruction cache is removed. (In a multiprocessor
system, the effect is more complex.)
Assumes the cache line size is at least 32 bytes, or at least
that dcbst and icbi apply to 32-byte lines. At present, all
PowerPC processors have line sizes of exactly 32 bytes. */
size_modified = lazy ? rel_offset_words : PLT_INITIAL_ENTRY_WORDS;
for (i = 0; i < size_modified; i+=8)
PPC_DCBST (plt + i);
PPC_SYNC;
for (i = 0; i < size_modified; i+=8)
PPC_ICBI (plt + i);
PPC_ISYNC;
}
return lazy;
}
void
__elf_machine_fixup_plt(struct link_map *map, const Elf32_Rela *reloc,
Elf32_Addr *reloc_addr, Elf32_Addr finaladdr)
{
Elf32_Sword delta = finaladdr - (Elf32_Word) (char *) reloc_addr;
if (delta << 6 >> 6 == delta)
*reloc_addr = OPCODE_B (delta);
else if (finaladdr <= 0x01fffffc || finaladdr >= 0xfe000000)
*reloc_addr = OPCODE_BA (finaladdr);
else
{
Elf32_Word *plt;
Elf32_Word index;
plt = (Elf32_Word *)((char *)map->l_addr
+ map->l_info[DT_PLTGOT]->d_un.d_val);
index = (reloc_addr - plt - PLT_INITIAL_ENTRY_WORDS)/2;
if (index >= PLT_DOUBLE_SIZE)
{
/* Slots greater than or equal to 2^13 have 4 words available
instead of two. */
/* FIXME: There are some possible race conditions in this code,
when called from 'fixup'.
1) Suppose that a lazy PLT entry is executing, a context switch
between threads (or a signal) occurs, and the new thread or
signal handler calls the same lazy PLT entry. Then the PLT entry
would be changed while it's being run, which will cause a segfault
(almost always).
2) Suppose the reverse: that a lazy PLT entry is being updated,
a context switch occurs, and the new code calls the lazy PLT
entry that is being updated. Then the half-fixed PLT entry will
be executed, which will also almost always cause a segfault.
These problems don't happen with the 2-word entries, because
only one of the two instructions are changed when a lazy entry
is retargeted at the actual PLT entry; the li instruction stays
the same (we have to update it anyway, because we might not be
updating a lazy PLT entry). */
reloc_addr[0] = OPCODE_LI (11, finaladdr);
reloc_addr[1] = OPCODE_ADDIS (11, 11, finaladdr + 0x8000 >> 16);
reloc_addr[2] = OPCODE_MTCTR (11);
reloc_addr[3] = OPCODE_BCTR ();
}
else
{
Elf32_Word num_plt_entries;
num_plt_entries = (map->l_info[DT_PLTRELSZ]->d_un.d_val
/ sizeof(Elf32_Rela));
plt[index+PLT_DATA_START_WORDS (num_plt_entries)] = finaladdr;
reloc_addr[0] = OPCODE_LI (11, index*4);
reloc_addr[1] = OPCODE_B (-(4*(index*2
+ 1
- PLT_LONGBRANCH_ENTRY_WORDS
+ PLT_INITIAL_ENTRY_WORDS)));
}
}
MODIFIED_CODE (reloc_addr);
}
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 const finaladdr,
int rinfo)
{
switch (rinfo)
{
case R_PPC_NONE:
return;
case R_PPC_ADDR32:
case R_PPC_UADDR32:
case R_PPC_GLOB_DAT:
case R_PPC_RELATIVE:
*reloc_addr = finaladdr;
return;
case R_PPC_ADDR24:
if (finaladdr > 0x01fffffc && finaladdr < 0xfe000000)
{
_dl_signal_error(0, map->l_name,
"R_PPC_ADDR24 relocation out of range");
}
*reloc_addr = *reloc_addr & 0xfc000003 | finaladdr & 0x3fffffc;
break;
case R_PPC_ADDR16:
case R_PPC_UADDR16:
if (finaladdr > 0x7fff && finaladdr < 0x8000)
{
_dl_signal_error(0, map->l_name,
"R_PPC_ADDR16 relocation out of range");
}
*(Elf32_Half*) reloc_addr = finaladdr;
break;
case R_PPC_ADDR16_LO:
*(Elf32_Half*) reloc_addr = finaladdr;
break;
case R_PPC_ADDR16_HI:
*(Elf32_Half*) reloc_addr = finaladdr >> 16;
break;
case R_PPC_ADDR16_HA:
*(Elf32_Half*) reloc_addr = (finaladdr + 0x8000) >> 16;
break;
case R_PPC_ADDR14:
case R_PPC_ADDR14_BRTAKEN:
case R_PPC_ADDR14_BRNTAKEN:
if (finaladdr > 0x7fff && finaladdr < 0x8000)
{
_dl_signal_error(0, map->l_name,
"R_PPC_ADDR14 relocation out of range");
}
*reloc_addr = *reloc_addr & 0xffff0003 | finaladdr & 0xfffc;
if (rinfo != R_PPC_ADDR14)
*reloc_addr = (*reloc_addr & 0xffdfffff
| (rinfo == R_PPC_ADDR14_BRTAKEN
^ finaladdr >> 31) << 21);
break;
case R_PPC_REL24:
{
Elf32_Sword delta = finaladdr - (Elf32_Word) (char *) reloc_addr;
if (delta << 6 >> 6 != delta)
{
_dl_signal_error(0, map->l_name,
"R_PPC_REL24 relocation out of range");
}
*reloc_addr = *reloc_addr & 0xfc000003 | delta & 0x3fffffc;
}
break;
case R_PPC_COPY:
if (sym == NULL)
/* This can happen in trace mode when an object could not be
found. */
return;
if (sym->st_size > refsym->st_size
|| (_dl_verbose && sym->st_size < refsym->st_size))
{
const char *strtab;
strtab = ((void *) map->l_addr
+ map->l_info[DT_STRTAB]->d_un.d_ptr);
_dl_sysdep_error (_dl_argv[0] ?: "<program name unknown>",
": Symbol `", strtab + refsym->st_name,
"' has different size in shared object, "
"consider re-linking\n", NULL);
}
memcpy (reloc_addr, (char *) finaladdr, MIN (sym->st_size,
refsym->st_size));
return;
case R_PPC_REL32:
*reloc_addr = finaladdr - (Elf32_Word) (char *) reloc_addr;
return;
case R_PPC_JMP_SLOT:
elf_machine_fixup_plt(map, reloc, reloc_addr, finaladdr);
return;
default:
_dl_sysdep_error (_dl_argv[0] ?: "<program name unknown>",
": Unknown relocation type\n", NULL);
return;
}
MODIFIED_CODE_NOQUEUE (reloc_addr);
}

528
sysdeps/powerpc/dl-machine.h
View File

@ -23,57 +23,9 @@
#define ELF_MACHINE_NAME "powerpc"
#include <assert.h>
#include <string.h>
#include <link.h>
#include <sys/param.h>
/* stuff for the PLT */
#define PLT_INITIAL_ENTRY_WORDS 18
#define PLT_LONGBRANCH_ENTRY_WORDS 10
#define PLT_DOUBLE_SIZE (1<<13)
#define PLT_ENTRY_START_WORDS(entry_number) \
(PLT_INITIAL_ENTRY_WORDS + (entry_number)*2 + \
((entry_number) > PLT_DOUBLE_SIZE ? \
((entry_number) - PLT_DOUBLE_SIZE)*2 : \
0))
#define PLT_DATA_START_WORDS(num_entries) PLT_ENTRY_START_WORDS(num_entries)
#define OPCODE_ADDI(rd,ra,simm) \
(0x38000000 | (rd) << 21 | (ra) << 16 | (simm) & 0xffff)
#define OPCODE_ADDIS(rd,ra,simm) \
(0x3c000000 | (rd) << 21 | (ra) << 16 | (simm) & 0xffff)
#define OPCODE_ADD(rd,ra,rb) \
(0x7c000214 | (rd) << 21 | (ra) << 16 | (rb) << 11)
#define OPCODE_B(target) (0x48000000 | (target) & 0x03fffffc)
#define OPCODE_BA(target) (0x48000002 | (target) & 0x03fffffc)
#define OPCODE_BCTR() 0x4e800420
#define OPCODE_LWZ(rd,d,ra) \
(0x80000000 | (rd) << 21 | (ra) << 16 | (d) & 0xffff)
#define OPCODE_MTCTR(rd) (0x7C0903A6 | (rd) << 21)
#define OPCODE_RLWINM(ra,rs,sh,mb,me) \
(0x54000000 | (rs) << 21 | (ra) << 16 | (sh) << 11 | (mb) << 6 | (me) << 1)
#define OPCODE_LI(rd,simm) OPCODE_ADDI(rd,0,simm)
#define OPCODE_SLWI(ra,rs,sh) OPCODE_RLWINM(ra,rs,sh,0,31-sh)
#define PPC_DCBST(where) asm volatile ("dcbst 0,%0" : : "r"(where))
#define PPC_SYNC asm volatile ("sync")
#define PPC_ISYNC asm volatile ("sync; isync")
#define PPC_ICBI(where) asm volatile ("icbi 0,%0" : : "r"(where))
#define PPC_DIE asm volatile ("tweq 0,0")
/* Use this when you've modified some code, but it won't be in the
instruction fetch queue (or when it doesn't matter if it is). */
#define MODIFIED_CODE_NOQUEUE(where) \
do { PPC_DCBST(where); PPC_SYNC; PPC_ICBI(where); } while (0)
/* Use this when it might be in the instruction queue. */
#define MODIFIED_CODE(where) \
do { PPC_DCBST(where); PPC_SYNC; PPC_ICBI(where); PPC_ISYNC; } while (0)
/* Return nonzero iff E_MACHINE is compatible with the running host. */
static inline int
extern inline int
elf_machine_matches_host (Elf32_Half e_machine)
{
return e_machine == EM_PPC;
@ -82,7 +34,7 @@ elf_machine_matches_host (Elf32_Half e_machine)
/* Return the link-time address of _DYNAMIC, stored as
the first value in the GOT. */
static inline Elf32_Addr
extern inline Elf32_Addr
elf_machine_dynamic (void)
{
Elf32_Addr *got;
@ -248,150 +200,16 @@ _dl_prof_resolve:
.previous
");
/* Initial entry point code for the dynamic linker.
The C function `_dl_start' is the real entry point;
its return value is the user program's entry point. */
#define RTLD_START \
static ElfW(Addr) _dl_start (void *arg) __attribute__((unused)); \
asm ("\
.section \".text\"
.align 2
.globl _start
.type _start,@function
_start:
# We start with the following on the stack, from top:
# argc (4 bytes);
# arguments for program (terminated by NULL);
# environment variables (terminated by NULL);
# arguments for the program loader.
# FIXME: perhaps this should do the same trick as elf/start.c?
/* 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");
# Call _dl_start with one parameter pointing at argc
mr 3,1
# (we have to frob the stack pointer a bit to allow room for
# _dl_start to save the link register)
li 4,0
addi 1,1,-16
stw 4,0(1)
bl _dl_start@local
# Now, we do our main work of calling initialisation procedures.
# The ELF ABI doesn't say anything about parameters for these,
# so we just pass argc, argv, and the environment.
# Changing these is strongly discouraged (not least because argc is
# passed by value!).
# Put our GOT pointer in r31,
bl _GLOBAL_OFFSET_TABLE_-4@local
mflr 31
# the address of _start in r30,
mr 30,3
# &_dl_argc in 29, &_dl_argv in 27, and _dl_default_scope in 28.
lwz 28,_dl_default_scope@got(31)
lwz 29,_dl_argc@got(31)
lwz 27,_dl_argv@got(31)
0:
# Set initfunc = _dl_init_next(_dl_default_scope[2])
lwz 3,8(28)
bl _dl_init_next@plt
# If initfunc is NULL, we exit the loop; otherwise,
cmpwi 3,0
beq 1f
# call initfunc(_dl_argc, _dl_argv, _dl_argv+_dl_argc+1)
mtlr 3
lwz 3,0(29)
lwz 4,0(27)
slwi 5,3,2
add 5,4,5
addi 5,5,4
blrl
# and loop.
b 0b
1:
# Now, to conform to the ELF ABI, we have to:
# Pass argc (actually _dl_argc) in r3;
lwz 3,0(29)
# pass argv (actually _dl_argv) in r4;
lwz 4,0(27)
# pass envp (actually _dl_argv+_dl_argc+1) in r5;
slwi 5,3,2
add 6,4,5
addi 5,6,4
# pass the auxilary vector in r6. This is passed to us just after _envp.
2: lwzu 0,4(6)
cmpwi 0,0,0
bne 2b
addi 6,6,4
# Pass a termination function pointer (in this case _dl_fini) in r7.
lwz 7,_dl_fini@got(31)
# Now, call the start function in r30...
mtctr 30
lwz 26,_dl_starting_up@got(31)
# Pass the stack pointer in r1 (so far so good), pointing to a NULL value.
# (This lets our startup code distinguish between a program linked statically,
# which linux will call with argc on top of the stack which will hopefully
# never be zero, and a dynamically linked program which will always have
# a NULL on the top of the stack).
# Take the opportunity to clear LR, so anyone who accidentally returns
# from _start gets SEGV. Also clear the next few words of the stack.
li 31,0
stw 31,0(1)
mtlr 31
stw 31,4(1)
stw 31,8(1)
stw 31,12(1)
# Clear _dl_starting_up.
stw 31,0(26)
# Go do it!
bctr
0:
.size _start,0b-_start
# Undo '.section text'.
.previous
");
/* The idea here is that to conform to the ABI, we are supposed to try
to load dynamic objects between 0x10000 (we actually use 0x40000 as
the lower bound, to increase the chance of a memory reference from
a null pointer giving a segfault) and the program's load address.
Regrettably, in this code we can't find the program's load address,
so we punt and choose 0x01800000, which is below the ABI's
recommended default, and what GNU ld currently chooses. We only use
the address as a preference for mmap, so if we get it wrong the
worst that happens is that it gets mapped somewhere else.
FIXME: Unfortunately, 'somewhere else' is probably right after the
program's break, which causes malloc to fail. We really need more
information here about the way memory is mapped. */
#define ELF_PREFERRED_ADDRESS_DATA \
static ElfW(Addr) _dl_preferred_address = 1
#define ELF_PREFERRED_ADDRESS(loader, maplength, mapstartpref) \
( { \
ElfW(Addr) prefd; \
if (mapstartpref != 0 && _dl_preferred_address == 1) \
_dl_preferred_address = mapstartpref; \
if (mapstartpref != 0) \
prefd = mapstartpref; \
else if (_dl_preferred_address == 1) \
prefd = _dl_preferred_address = \
(0x01800000 - maplength - 0x10000) & \
~(_dl_pagesize - 1); \
else if (_dl_preferred_address < maplength + 0x50000) \
prefd = 0; \
else \
prefd = _dl_preferred_address = \
((_dl_preferred_address - maplength - 0x10000) \
& ~(_dl_pagesize - 1)); \
prefd; \
} )
#define ELF_FIXED_ADDRESS(loader, mapstart) \
( { \
if (mapstart != 0 && _dl_preferred_address == 1) \
_dl_preferred_address = mapstart; \
} )
/* 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. */
@ -417,203 +235,25 @@ static ElfW(Addr) _dl_preferred_address = 1
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
/* A PLT entry does one of three things:
(i) Jumps to the actual routine. Such entries are set up above, in
elf_machine_rela.
(ii) Jumps to the actual routine via glue at the start of the PLT.
We do this by putting the address of the routine in space
allocated at the end of the PLT, and when the PLT entry is
called we load the offset of that word (from the start of the
space) into r11, then call the glue, which loads the word and
branches to that address. These entries are set up in
elf_machine_rela, but the glue is set up here.
(iii) Loads the index of this PLT entry (we count the double-size
entries as one entry for this purpose) into r11, then
branches to code at the start of the PLT. This code then
calls `fixup', in dl-runtime.c, via the glue in the macro
ELF_MACHINE_RUNTIME_TRAMPOLINE, which resets the PLT entry to
be one of the above two types. These entries are set up here. */
static inline int
elf_machine_runtime_setup (struct link_map *map, int lazy, int profile)
{
if (map->l_info[DT_JMPREL])
{
Elf32_Word i;
/* Fill in the PLT. Its initial contents are directed to a
function earlier in the PLT which arranges for the dynamic
linker to be called back. */
Elf32_Word *plt = (Elf32_Word *) ((char *) map->l_addr
+ map->l_info[DT_PLTGOT]->d_un.d_val);
Elf32_Word num_plt_entries = (map->l_info[DT_PLTRELSZ]->d_un.d_val
/ sizeof (Elf32_Rela));
Elf32_Word rel_offset_words = PLT_DATA_START_WORDS (num_plt_entries);
Elf32_Word size_modified;
extern void _dl_runtime_resolve (void);
extern void _dl_prof_resolve (void);
Elf32_Word dlrr;
dlrr = (Elf32_Word)(char *)(profile
? _dl_prof_resolve
: _dl_runtime_resolve);
if (lazy)
for (i = 0; i < num_plt_entries; i++)
{
Elf32_Word offset = PLT_ENTRY_START_WORDS (i);
if (i >= PLT_DOUBLE_SIZE)
{
plt[offset ] = OPCODE_LI (11, i * 4);
plt[offset+1] = OPCODE_ADDIS (11, 11, (i * 4 + 0x8000) >> 16);
plt[offset+2] = OPCODE_B (-(4 * (offset + 2)));
}
else
{
plt[offset ] = OPCODE_LI (11, i * 4);
plt[offset+1] = OPCODE_B (-(4 * (offset + 1)));
}
}
/* Multiply index of entry by 3 (in r11). */
plt[0] = OPCODE_SLWI (12, 11, 1);
plt[1] = OPCODE_ADD (11, 12, 11);
if (dlrr <= 0x01fffffc || dlrr >= 0xfe000000)
{
/* Load address of link map in r12. */
plt[2] = OPCODE_LI (12, (Elf32_Word) (char *) map);
plt[3] = OPCODE_ADDIS (12, 12, (((Elf32_Word) (char *) map
+ 0x8000) >> 16));
/* Call _dl_runtime_resolve. */
plt[4] = OPCODE_BA (dlrr);
}
else
{
/* Get address of _dl_runtime_resolve in CTR. */
plt[2] = OPCODE_LI (12, dlrr);
plt[3] = OPCODE_ADDIS (12, 12, (dlrr + 0x8000) >> 16);
plt[4] = OPCODE_MTCTR (12);
/* Load address of link map in r12. */
plt[5] = OPCODE_LI (12, (Elf32_Word) (char *) map);
plt[6] = OPCODE_ADDIS (12, 12, (((Elf32_Word) (char *) map
+ 0x8000) >> 16));
/* Call _dl_runtime_resolve. */
plt[7] = OPCODE_BCTR ();
}
/* Convert the index in r11 into an actual address, and get the
word at that address. */
plt[PLT_LONGBRANCH_ENTRY_WORDS] =
OPCODE_ADDIS (11, 11, (((Elf32_Word) (char*) (plt + rel_offset_words)
+ 0x8000) >> 16));
plt[PLT_LONGBRANCH_ENTRY_WORDS+1] =
OPCODE_LWZ (11, (Elf32_Word) (char*) (plt+rel_offset_words), 11);
/* Call the procedure at that address. */
plt[PLT_LONGBRANCH_ENTRY_WORDS+2] = OPCODE_MTCTR (11);
plt[PLT_LONGBRANCH_ENTRY_WORDS+3] = OPCODE_BCTR ();
/* Now, we've modified code (quite a lot of code, possibly). We
need to write the changes from the data cache to a
second-level unified cache, then make sure that stale data in
the instruction cache is removed. (In a multiprocessor
system, the effect is more complex.)
Assumes the cache line size is at least 32 bytes, or at least
that dcbst and icbi apply to 32-byte lines. At present, all
PowerPC processors have line sizes of exactly 32 bytes. */
size_modified = lazy ? rel_offset_words : PLT_INITIAL_ENTRY_WORDS;
for (i = 0; i < size_modified; i+=8)
PPC_DCBST (plt + i);
PPC_SYNC;
for (i = 0; i < size_modified; i+=8)
PPC_ICBI (plt + i);
PPC_ISYNC;
}
return lazy;
}
static inline void
extern inline void
elf_machine_lazy_rel (Elf32_Addr l_addr, const Elf32_Rela *reloc)
{
/* elf_machine_runtime_setup handles this. */
}
static inline void
elf_machine_fixup_plt(struct link_map *map, const Elf32_Rela *reloc,
Elf32_Addr *reloc_addr, Elf32_Addr finaladdr)
{
Elf32_Sword delta = finaladdr - (Elf32_Word) (char *) reloc_addr;
if (delta << 6 >> 6 == delta)
*reloc_addr = OPCODE_B (delta);
else if (finaladdr <= 0x01fffffc || finaladdr >= 0xfe000000)
*reloc_addr = OPCODE_BA (finaladdr);
else
{
Elf32_Word *plt;
Elf32_Word index;
plt = (Elf32_Word *)((char *)map->l_addr
+ map->l_info[DT_PLTGOT]->d_un.d_val);
index = (reloc_addr - plt - PLT_INITIAL_ENTRY_WORDS)/2;
if (index >= PLT_DOUBLE_SIZE)
{
/* Slots greater than or equal to 2^13 have 4 words available
instead of two. */
/* FIXME: There are some possible race conditions in this code,
when called from 'fixup'.
1) Suppose that a lazy PLT entry is executing, a context switch
between threads (or a signal) occurs, and the new thread or
signal handler calls the same lazy PLT entry. Then the PLT entry
would be changed while it's being run, which will cause a segfault
(almost always).
2) Suppose the reverse: that a lazy PLT entry is being updated,
a context switch occurs, and the new code calls the lazy PLT
entry that is being updated. Then the half-fixed PLT entry will
be executed, which will also almost always cause a segfault.
These problems don't happen with the 2-word entries, because
only one of the two instructions are changed when a lazy entry
is retargeted at the actual PLT entry; the li instruction stays
the same (we have to update it anyway, because we might not be
updating a lazy PLT entry). */
reloc_addr[0] = OPCODE_LI (11, finaladdr);
reloc_addr[1] = OPCODE_ADDIS (11, 11, finaladdr + 0x8000 >> 16);
reloc_addr[2] = OPCODE_MTCTR (11);
reloc_addr[3] = OPCODE_BCTR ();
}
else
{
Elf32_Word num_plt_entries;
num_plt_entries = (map->l_info[DT_PLTRELSZ]->d_un.d_val
/ sizeof(Elf32_Rela));
plt[index+PLT_DATA_START_WORDS (num_plt_entries)] = finaladdr;
reloc_addr[0] = OPCODE_LI (11, index*4);
reloc_addr[1] = OPCODE_B (-(4*(index*2
+ 1
- PLT_LONGBRANCH_ENTRY_WORDS
+ PLT_INITIAL_ENTRY_WORDS)));
}
}
MODIFIED_CODE (reloc_addr);
}
/* Change the PLT entry whose reloc is 'reloc' to call the actual routine. */
extern void __elf_machine_fixup_plt(struct link_map *map,
const Elf32_Rela *reloc,
Elf32_Addr *reloc_addr,
Elf32_Addr finaladdr);
#define elf_machine_fixup_plt __elf_machine_fixup_plt
/* Return the final value of a plt relocation. */
static inline Elf32_Addr
extern inline Elf32_Addr
elf_machine_plt_value (struct link_map *map, const Elf32_Rela *reloc,
Elf32_Addr value)
{
@ -624,32 +264,38 @@ elf_machine_plt_value (struct link_map *map, const Elf32_Rela *reloc,
#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. */
static void
extern 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)
{
#ifndef RTLD_BOOTSTRAP
const Elf32_Sym *const refsym = sym;
extern char **_dl_argv;
#endif
Elf32_Word loadbase, finaladdr;
const int rinfo = ELF32_R_TYPE (reloc->r_info);
if (rinfo == R_PPC_NONE)
return;
assert (sym != NULL);
/* 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 ((sym->st_shndx != SHN_UNDEF
&& ELF32_ST_BIND (sym->st_info) == STB_LOCAL)
|| rinfo == R_PPC_RELATIVE)
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;
@ -670,99 +316,27 @@ elf_machine_rela (struct link_map *map, const Elf32_Rela *reloc,
+ reloc->r_addend);
}
/* This is still an if/else if chain because GCC uses the GOT to find
the table for table-based switch statements, and we haven't set it
up yet. */
if (rinfo == R_PPC_UADDR32 ||
rinfo == R_PPC_GLOB_DAT ||
rinfo == R_PPC_ADDR32 ||
rinfo == R_PPC_RELATIVE)
/* 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;
}
#ifndef RTLD_BOOTSTRAP
else if (rinfo == R_PPC_ADDR16_LO)
{
*(Elf32_Half*) reloc_addr = finaladdr;
}
else if (rinfo == R_PPC_ADDR16_HI)
{
*(Elf32_Half*) reloc_addr = finaladdr >> 16;
}
else if (rinfo == R_PPC_ADDR16_HA)
{
*(Elf32_Half*) reloc_addr = (finaladdr + 0x8000) >> 16;
}
else if (rinfo == R_PPC_REL24)
{
Elf32_Sword delta = finaladdr - (Elf32_Word) (char *) reloc_addr;
if (delta << 6 >> 6 != delta)
{
_dl_signal_error(0, map->l_name,
"R_PPC_REL24 relocation out of range");
}
*reloc_addr = *reloc_addr & 0xfc000003 | delta & 0x3fffffc;
}
else if (rinfo == R_PPC_ADDR24)
{
if (finaladdr << 6 >> 6 != finaladdr)
{
_dl_signal_error(0, map->l_name,
"R_PPC_ADDR24 relocation out of range");
}
*reloc_addr = *reloc_addr & 0xfc000003 | finaladdr & 0x3fffffc;
}
else if (rinfo == R_PPC_COPY)
{
if (sym == NULL)
/* This can happen in trace mode when an object could not be
found. */
return;
if (sym->st_size > refsym->st_size
|| (_dl_verbose && sym->st_size < refsym->st_size))
{
const char *strtab;
strtab = ((void *) map->l_addr
+ map->l_info[DT_STRTAB]->d_un.d_ptr);
_dl_sysdep_error (_dl_argv[0] ?: "<program name unknown>",
": Symbol `", strtab + refsym->st_name,
"' has different size in shared object, "
"consider re-linking\n", NULL);
}
memcpy (reloc_addr, (char *) finaladdr, MIN (sym->st_size,
refsym->st_size));
}
#endif
else if (rinfo == R_PPC_REL32)
{
*reloc_addr = finaladdr - (Elf32_Word) (char *) reloc_addr;
}
else if (rinfo == R_PPC_JMP_SLOT)
{
elf_machine_fixup_plt (map, reloc, reloc_addr, finaladdr);
}
else
{
#ifdef RTLD_BOOTSTRAP
PPC_DIE; /* There is no point calling _dl_sysdep_error, it
almost certainly hasn't been relocated properly. */
#else
_dl_sysdep_error (_dl_argv[0] ?: "<program name unknown>",
": Unknown relocation type\n", NULL);
#endif
}
#ifndef RTLD_BOOTSTRAP
if (rinfo == R_PPC_ADDR16_LO ||
rinfo == R_PPC_ADDR16_HI ||
rinfo == R_PPC_ADDR16_HA ||
rinfo == R_PPC_REL24 ||
rinfo == R_PPC_ADDR24)
MODIFIED_CODE_NOQUEUE (reloc_addr);
#endif
__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 */

111
sysdeps/powerpc/dl-start.S Normal file
View File

@ -0,0 +1,111 @@
/* Machine-dependent ELF startup code. PowerPC version.
Copyright (C) 1995, 1996, 1997, 1998 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. */
#include <sysdep.h>
/* Initial entry point code for the dynamic linker.
The C function `_dl_start' is the real entry point;
its return value is the user program's entry point. */
ENTRY(_start)
/* We start with the following on the stack, from top:
argc (4 bytes);
arguments for program (terminated by NULL);
environment variables (terminated by NULL);
arguments for the program loader. */
/* Call _dl_start with one parameter pointing at argc */
mr %r3,%r1
/* (we have to frob the stack pointer a bit to allow room for
_dl_start to save the link register). */
li %r4,0
addi %r1,%r1,-16
stw %r4,0(%r1)
bl _dl_start@local
/* Now, we do our main work of calling initialisation procedures.
The ELF ABI doesn't say anything about parameters for these,
so we just pass argc, argv, and the environment.
Changing these is strongly discouraged (not least because argc is
passed by value!). */
/* Put our GOT pointer in r31, */
bl _GLOBAL_OFFSET_TABLE_-4@local
mflr %r31
/* the address of _start in r30, */
mr %r30,%r3
/* &_dl_argc in 29, &_dl_argv in 27, and _dl_default_scope in 28. */
lwz %r28,_dl_default_scope@got(%r31)
lwz %r29,_dl_argc@got(%r31)
lwz %r27,_dl_argv@got(%r31)
0:
/* Set initfunc = _dl_init_next(_dl_default_scope[2]) */
lwz %r3,8(%r28)
bl _dl_init_next@plt
/* If initfunc is NULL, we exit the loop; otherwise, */
cmpwi %r3,0
beq 1f
/* call initfunc(_dl_argc, _dl_argv, _dl_argv+_dl_argc+1) */
mtlr %r3
lwz %r3,0(%r29)
lwz %r4,0(%r27)
slwi %r5,%r3,2
add %r5,%r4,%r5
addi %r5,%r5,4
blrl
/* and loop. */
b 0b
1:
/* Now, to conform to the ELF ABI, we have to: */
/* Pass argc (actually _dl_argc) in r3; */
lwz %r3,0(%r29)
/* pass argv (actually _dl_argv) in r4; */
lwz %r4,0(%r27)
/* pass envp (actually _dl_argv+_dl_argc+1) in r5; */
slwi %r5,%r3,2
add %r6,%r4,%r5
addi %r5,%r6,4
/* pass the auxilary vector in r6. This is passed to us just after _envp. */
2: lwzu %r0,4(%r6)
cmpwi %r0,0
bne 2b
addi %r6,%r6,4
/* Pass a termination function pointer (in this case _dl_fini) in r7. */
lwz %r7,_dl_fini@got(%r31)
/* Now, call the start function in r30... */
mtctr %r30
lwz %r26,_dl_starting_up@got(%r31)
/* Pass the stack pointer in r1 (so far so good), pointing to a NULL value.
(This lets our startup code distinguish between a program linked statically,
which linux will call with argc on top of the stack which will hopefully
never be zero, and a dynamically linked program which will always have
a NULL on the top of the stack).
Take the opportunity to clear LR, so anyone who accidentally returns
from _start gets SEGV. Also clear the next few words of the stack. */
li %r31,0
stw %r31,0(%r1)
mtlr %r31
stw %r31,4(%r1)
stw %r31,8(%r1)
stw %r31,12(%r1)
/* Clear _dl_starting_up. */
stw %r31,0(%r26)
/* Go do it! */
bctr
END(_start)