diff options
| -rw-r--r-- | ChangeLog | 32 | ||||
| -rw-r--r-- | debug/Makefile | 3 | ||||
| -rw-r--r-- | elf/dl-load.c | 9 | ||||
| -rw-r--r-- | elf/dynamic-link.h | 91 | ||||
| -rw-r--r-- | elf/link.h | 4 | ||||
| -rw-r--r-- | elf/rtld.c | 18 | ||||
| -rw-r--r-- | manual/examples/argp-ex1.c | 5 | ||||
| -rw-r--r-- | manual/examples/argp-ex2.c | 21 | ||||
| -rw-r--r-- | manual/examples/argp-ex3.c | 54 | ||||
| -rw-r--r-- | manual/examples/argp-ex4.c | 23 | ||||
| -rw-r--r-- | manual/startup.texi | 6 | ||||
| -rw-r--r-- | posix/glob.h | 23 | ||||
| -rw-r--r-- | sysdeps/powerpc/Makefile | 5 | ||||
| -rw-r--r-- | sysdeps/powerpc/dl-machine.c | 442 | ||||
| -rw-r--r-- | sysdeps/powerpc/dl-machine.h | 528 | ||||
| -rw-r--r-- | sysdeps/powerpc/dl-start.S | 111 |
16 files changed, 848 insertions, 527 deletions
@@ -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. diff --git a/debug/Makefile b/debug/Makefile index fc1f950572..698ad07d12 100644 --- a/debug/Makefile +++ b/debug/Makefile @@ -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 $@ diff --git a/elf/dl-load.c b/elf/dl-load.c index 81c1d8ba2e..e961cb0784 100644 --- a/elf/dl-load.c +++ b/elf/dl-load.c @@ -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) diff --git a/elf/dynamic-link.h b/elf/dynamic-link.h index 9d7ae3d3fa..9e2ca03543 100644 --- a/elf/dynamic-link.h +++ b/elf/dynamic-link.h @@ -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) \ - { \ - 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)); \ + if ((lazy) \ + && (map)->l_info[DT_PLTREL] \ + && (map)->l_info[DT_PLTREL]->d_un.d_val == DT_##RELOC) \ + { \ + 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 diff --git a/elf/link.h b/elf/link.h index 40f7435a84..e31dd2dd65 100644 --- a/elf/link.h +++ b/elf/link.h @@ -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 */ diff --git a/elf/rtld.c b/elf/rtld.c index 3ae51e68ab..b25fb20fd3 100644 --- a/elf/rtld.c +++ b/elf/rtld.c @@ -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) { diff --git a/manual/examples/argp-ex1.c b/manual/examples/argp-ex1.c index c87ebbb532..50ac0ed978 100644 --- a/manual/examples/argp-ex1.c +++ b/manual/examples/argp-ex1.c @@ -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) diff --git a/manual/examples/argp-ex2.c b/manual/examples/argp-ex2.c index d1b149b494..55f59f2ab8 100644 --- a/manual/examples/argp-ex2.c +++ b/manual/examples/argp-ex2.c @@ -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[] = diff --git a/manual/examples/argp-ex3.c b/manual/examples/argp-ex3.c index 363ee59e11..87d993f8ae 100644 --- a/manual/examples/argp-ex3.c +++ b/manual/examples/argp-ex3.c @@ -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[] = diff --git a/manual/examples/argp-ex4.c b/manual/examples/argp-ex4.c index 24dd417a81..fa5a8d00ec 100644 --- a/manual/examples/argp-ex4.c +++ b/manual/examples/argp-ex4.c @@ -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> diff --git a/manual/startup.texi b/manual/startup.texi index dd21c89e6f..bea6c39676 100644 --- a/manual/startup.texi +++ b/manual/startup.texi @@ -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 diff --git a/posix/glob.h b/posix/glob.h index 609f2177e5..f4c0974011 100644 --- a/posix/glob.h +++ b/posix/glob.h @@ -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 diff --git a/sysdeps/powerpc/Makefile b/sysdeps/powerpc/Makefile index 0f8860b1d0..d2f0eb275c 100644 --- a/sysdeps/powerpc/Makefile +++ b/sysdeps/powerpc/Makefile @@ -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 diff --git a/sysdeps/powerpc/dl-machine.c b/sysdeps/powerpc/dl-machine.c new file mode 100644 index 0000000000..095a3f21d8 --- /dev/null +++ b/sysdeps/powerpc/dl-machine.c @@ -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); +} diff --git a/sysdeps/powerpc/dl-machine.h b/sysdeps/powerpc/dl-machine.h index ab75aa1390..bb449a9d34 100644 --- a/sysdeps/powerpc/dl-machine.h +++ b/sysdeps/powerpc/dl-machine.h @@ -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? - - # 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 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"); -/* 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 */ diff --git a/sysdeps/powerpc/dl-start.S b/sysdeps/powerpc/dl-start.S new file mode 100644 index 0000000000..91c0896a8f --- /dev/null +++ b/sysdeps/powerpc/dl-start.S @@ -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) |