Permalink
Cannot retrieve contributors at this time
Name already in use
A tag already exists with the provided branch name. Many Git commands accept both tag and branch names, so creating this branch may cause unexpected behavior. Are you sure you want to create this branch?
glibc/sysdeps/m68k/dl-machine.h
Go to fileThis commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
289 lines (254 sloc)
8.76 KB
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
/* Machine-dependent ELF dynamic relocation inline functions. m68k version. | |
Copyright (C) 1996, 1997 Free Software Foundation, Inc. | |
This file is part of the GNU C Library. | |
The GNU C Library is free software; you can redistribute it and/or | |
modify it under the terms of the GNU Library General Public License as | |
published by the Free Software Foundation; either version 2 of the | |
License, or (at your option) any later version. | |
The GNU C Library is distributed in the hope that it will be useful, | |
but WITHOUT ANY WARRANTY; without even the implied warranty of | |
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
Library General Public License for more details. | |
You should have received a copy of the GNU Library General Public | |
License along with the GNU C Library; see the file COPYING.LIB. If | |
not, write to the Free Software Foundation, Inc., | |
59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ | |
#ifndef dl_machine_h | |
#define dl_machine_h | |
#define ELF_MACHINE_NAME "m68k" | |
#include <sys/param.h> | |
#include <assert.h> | |
/* Return nonzero iff E_MACHINE is compatible with the running host. */ | |
static inline int | |
elf_machine_matches_host (Elf32_Half e_machine) | |
{ | |
switch (e_machine) | |
{ | |
case EM_68K: | |
return 1; | |
default: | |
return 0; | |
} | |
} | |
/* Return the link-time address of _DYNAMIC. Conveniently, this is the | |
first element of the GOT. This must be inlined in a function which | |
uses global data. */ | |
static inline Elf32_Addr | |
elf_machine_dynamic (void) | |
{ | |
register Elf32_Addr *got asm ("%a5"); | |
return *got; | |
} | |
/* Return the run-time load address of the shared object. */ | |
static inline Elf32_Addr | |
elf_machine_load_address (void) | |
{ | |
Elf32_Addr addr; | |
asm (".Lhere: lea .Lhere(%%pc), %0\n" | |
" sub.l %#.Lhere, %0" | |
: "=a" (addr)); | |
return addr; | |
} | |
/* The `subl' insn above will contain an R_68K_RELATIVE relocation | |
entry intended to insert the run-time address of the label `.Lhere'. | |
This will be the first relocation in the text of the dynamic | |
linker; we skip it to avoid trying to modify read-only text in this | |
early stage. */ | |
#define ELF_MACHINE_BEFORE_RTLD_RELOC(dynamic_info) \ | |
((dynamic_info)[DT_RELA]->d_un.d_ptr += sizeof (Elf32_Rela), \ | |
(dynamic_info)[DT_RELASZ]->d_un.d_val -= sizeof (Elf32_Rela)) | |
/* 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. */ | |
static inline void | |
elf_machine_runtime_setup (struct link_map *l, int lazy) | |
{ | |
Elf32_Addr *got; | |
extern void _dl_runtime_resolve (Elf32_Word); | |
if (l->l_info[DT_JMPREL] && lazy) | |
{ | |
/* The GOT entries for functions in the PLT have not yet been | |
filled in. Their initial contents will arrange when called | |
to push an offset into the .rela.plt section, push | |
_GLOBAL_OFFSET_TABLE_[1], and then jump to | |
_GLOBAL_OFFSET_TABLE_[2]. */ | |
got = (Elf32_Addr *) (l->l_addr + l->l_info[DT_PLTGOT]->d_un.d_ptr); | |
got[1] = (Elf32_Addr) l; /* Identify this shared object. */ | |
/* This function will get called to fix up the GOT entry | |
indicated by the offset on the stack, and then jump to the | |
resolved address. */ | |
got[2] = (Elf32_Addr) &_dl_runtime_resolve; | |
} | |
/* This code is used in dl-runtime.c to call the `fixup' function | |
and then redirect to the address it returns. */ | |
#define ELF_MACHINE_RUNTIME_TRAMPOLINE asm ("\ | |
| Trampoline for _dl_runtime_resolver | |
.globl _dl_runtime_resolve | |
.type _dl_runtime_resolve, @function | |
_dl_runtime_resolve: | |
| Save %a0 (struct return address) and %a1. | |
move.l %a0, -(%sp) | |
move.l %a1, -(%sp) | |
| Call the real address resolver. | |
jbsr fixup | |
| Restore register %a0 and %a1. | |
move.l (%sp)+, %a1 | |
move.l (%sp)+, %a0 | |
| Pop parameters | |
addq.l #8, %sp | |
| Call real function. | |
jmp (%d0) | |
.size _dl_runtime_resolve, . - _dl_runtime_resolve | |
"); | |
#define ELF_MACHINE_RUNTIME_FIXUP_ARGS long int save_a0, long int save_a1 | |
/* The PLT uses Elf32_Rela relocs. */ | |
#define elf_machine_relplt elf_machine_rela | |
} | |
/* Mask identifying addresses reserved for the user program, | |
where the dynamic linker should not map anything. */ | |
#define ELF_MACHINE_USER_ADDRESS_MASK 0x80000000UL | |
/* 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 asm ("\ | |
.text | |
.globl _start | |
.globl _dl_start_user | |
_start: | |
move.l %sp, -(%sp) | |
jbsr _dl_start | |
addq.l #4, %sp | |
_dl_start_user: | |
| Save the user entry point address in %a4. | |
move.l %d0, %a4 | |
| Point %a5 at the GOT. | |
lea _GLOBAL_OFFSET_TABLE_@GOTPC(%pc), %a5 | |
| See if we were run as a command with the executable file | |
| name as an extra leading argument. | |
move.l ([_dl_skip_args@GOT, %a5]), %d0 | |
jeq 0f | |
| Pop the original argument count | |
move.l (%sp)+, %d1 | |
| Subtract _dl_skip_args from it. | |
sub.l %d0, %d1 | |
| Adjust the stack pointer to skip _dl_skip_args words. | |
lea (%sp, %d0*4), %sp | |
| Push back the modified argument count. | |
move.l %d1, -(%sp) | |
0: | Push _dl_default_scope[2] as argument in _dl_init_next call below. | |
move.l ([_dl_default_scope@GOT, %a5], 8), %d2 | |
0: move.l %d2, -(%sp) | |
| Call _dl_init_next to return the address of an initializer | |
| function to run. | |
bsr.l _dl_init_next@PLTPC | |
add.l #4, %sp | Pop argument. | |
| Check for zero return, when out of initializers. | |
tst.l %d0 | |
jeq 1f | |
| Call the shared object initializer function. | |
| NOTE: We depend only on the registers (%d2, %a4 and %a5) | |
| and the return address pushed by this call; | |
| the initializer is called with the stack just | |
| as it appears on entry, and it is free to move | |
| the stack around, as long as it winds up jumping to | |
| the return address on the top of the stack. | |
move.l %d0, %a0 | |
jsr (%a0) | |
| Loop to call _dl_init_next for the next initializer. | |
jra 0b | |
1: | Clear the startup flag. | |
clr.l _dl_starting_up@GOT(%a5) | |
| Pass our finalizer function to the user in %a1. | |
move.l _dl_fini@GOT(%a5), %a1 | |
| Initialize %fp with the stack pointer. | |
move.l %sp, %fp | |
| Jump to the user's entry point. | |
jmp (%a4)"); | |
/* Nonzero iff TYPE describes a relocation that should | |
skip the executable when looking up the symbol value. */ | |
#define elf_machine_lookup_noexec_p(type) ((type) == R_68K_COPY) | |
/* Nonzero iff TYPE describes relocation of a PLT entry, so | |
PLT entries should not be allowed to define the value. */ | |
#define elf_machine_lookup_noplt_p(type) ((type) == R_68K_JMP_SLOT) | |
/* A reloc type used for ld.so cmdline arg lookups to reject PLT entries. */ | |
#define ELF_MACHINE_RELOC_NOPLT R_68K_JMP_SLOT | |
/* The m68k never uses Elf32_Rel relocations. */ | |
#define ELF_MACHINE_NO_REL 1 | |
#endif /* !dl_machine_h */ | |
#ifdef RESOLVE | |
/* Perform the relocation specified by RELOC and SYM (which is fully resolved). | |
MAP is the object containing the reloc. */ | |
static inline void | |
elf_machine_rela (struct link_map *map, const Elf32_Rela *reloc, | |
const Elf32_Sym *sym, const struct r_found_version *version) | |
{ | |
Elf32_Addr *const reloc_addr = (void *) (map->l_addr + reloc->r_offset); | |
if (ELF32_R_TYPE (reloc->r_info) == R_68K_RELATIVE) | |
*reloc_addr = map->l_addr + reloc->r_addend; | |
else | |
{ | |
const Elf32_Sym *const refsym = sym; | |
Elf32_Addr value = RESOLVE (&sym, version, ELF32_R_TYPE (reloc->r_info)); | |
if (sym) | |
value += sym->st_value; | |
switch (ELF32_R_TYPE (reloc->r_info)) | |
{ | |
case R_68K_COPY: | |
if (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 ("Symbol `", strtab + refsym->st_name, | |
"' has different size in shared object, " | |
"consider re-linking\n", NULL); | |
} | |
memcpy (reloc_addr, (void *) value, MIN (sym->st_size, | |
refsym->st_size)); | |
break; | |
case R_68K_GLOB_DAT: | |
case R_68K_JMP_SLOT: | |
*reloc_addr = value; | |
break; | |
case R_68K_8: | |
*(char *) reloc_addr = value + reloc->r_addend; | |
break; | |
case R_68K_16: | |
*(short *) reloc_addr = value + reloc->r_addend; | |
break; | |
case R_68K_32: | |
*reloc_addr = value + reloc->r_addend; | |
break; | |
case R_68K_PC8: | |
*(char *) reloc_addr | |
= value + reloc->r_addend - (Elf32_Addr) reloc_addr; | |
break; | |
case R_68K_PC16: | |
*(short *) reloc_addr | |
= value + reloc->r_addend - (Elf32_Addr) reloc_addr; | |
break; | |
case R_68K_PC32: | |
*reloc_addr = value + reloc->r_addend - (Elf32_Addr) reloc_addr; | |
break; | |
case R_68K_NONE: /* Alright, Wilbur. */ | |
break; | |
default: | |
assert (! "unexpected dynamic reloc type"); | |
break; | |
} | |
} | |
} | |
static inline void | |
elf_machine_lazy_rel (struct link_map *map, const Elf32_Rela *reloc) | |
{ | |
Elf32_Addr *const reloc_addr = (void *) (map->l_addr + reloc->r_offset); | |
switch (ELF32_R_TYPE (reloc->r_info)) | |
{ | |
case R_68K_JMP_SLOT: | |
*reloc_addr += map->l_addr; | |
break; | |
default: | |
assert (! "unexpected PLT reloc type"); | |
break; | |
} | |
} | |
#endif /* RESOLVE */ |