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Re: mips64 n32 and n64 support in dl-machine.h
On Mar 14, 2003, Andreas Jaeger <aj at suse dot de> wrote:
> Getting rid of the mips64-specific file is definitly fine. I don't
> think it ever worked.
Should I put it in in advance, or wait to check both files in at once?
>> [...]
>> Index: sysdeps/mips/dl-machine.h
>> [...]
>> -/* The MIPS never uses Elfxx_Rela relocations. */
>> +/* No mips dynamic relocations are RELA. We do have code in this file
>> + is conditional to ! ELF_MACHINE_NO_RELA. It was never
> Shouldn't this be: "We do have code in this file that is..." ?
Yes, thanks. I'm taking it out, along with the code referenced in the
new comment.
>> + __builtin_memcpy (&reloc_value, reloc_addr, sizeof (reloc_value));
> Why is this line needed? I don't understand the need for it.
To support mis-aligned relocations. According to Ralf Baechle, we
must support them. I had this in the ChangeLog, but somehow got rid
of it while cleaning up some duplication.
> And why a memcpy and not just an assignment? Please add a comment to
> explain this line - and the other memcpy line below.
Done.
> I suggest to leave this out completly since it's not used anywhere.
Ok. I'm adding comments for any differences I had found out between
them.
Here's the revised patch. Ok?
Index: ChangeLog
2003-03-14 Alexandre Oliva <aoliva at redhat dot com>
* sysdeps/mips/dl-machine.h: Include sys/asm.h.
(elf_machine_matches_host): Prevent linking of o32 and n32
together.
(elf_machine_dynamic): Document assumption on $gp.
(STRINGXP, STRINGXV, STRINGV_): New macros.
(elf_machine_load_address): Use them to stringize PTR_LA and
PTR_SUBU.
(ELF_DL_FRAME_SIZE, ELF_DL_SAVE_ARG_REGS,
ELF_DL_RESTORE_ARG_REGS, IFABIO32): New macros used in...
(_dl_runtime_resolve): Adjust it for all 3 ABIs.
(__dl_runtime_resolve): Cast the symtab initializer to the
right type.
(RTLD_START): Use it. Adjust it for all 3 ABIs.
(elf_machine_rel): Mark as always_inline in RTLD_BOOTSTRAP.
Handle 64-bit R_MIPS_REL composite relocation and accept
R_MIPS_64 relocations to shift addend size to 64 bits.
Document assumption regarding local GOT entries. Document
backward-compatibility departing from the ABI behavior in
applying relocations that reference section symbols, no longer
used. Support relocations to mis-aligned offsets.
* sysdeps/mips/mips64/dl-machine.h: Deleted, obsolete.
Index: sysdeps/mips/mips64/dl-machine.h
===================================================================
RCS file: sysdeps/mips/mips64/dl-machine.h
diff -N sysdeps/mips/mips64/dl-machine.h
--- sysdeps/mips/mips64/dl-machine.h 28 Feb 2002 22:36:31 -0000 1.21
+++ /dev/null 1 Jan 1970 00:00:00 -0000
@@ -1,594 +0,0 @@
-/* Machine-dependent ELF dynamic relocation inline functions. MIPS64 version.
- Copyright (C) 1996,1997,1999,2000,2001,2002 Free Software Foundation, Inc.
- This file is part of the GNU C Library.
- Contributed by Kazumoto Kojima <kkojima at info dot kanagawa-u dot ac dot jp>.
-
- The GNU C Library is free software; you can redistribute it and/or
- modify it under the terms of the GNU Lesser General Public
- License as published by the Free Software Foundation; either
- version 2.1 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
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public
- License along with the GNU C Library; 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 "MIPS"
-
-#define ELF_MACHINE_NO_PLT
-
-#include <entry.h>
-
-#ifndef ENTRY_POINT
-#error ENTRY_POINT needs to be defined for MIPS.
-#endif
-
-#ifndef _RTLD_PROLOGUE
-# define _RTLD_PROLOGUE(entry) "\n\t.globl " __STRING(entry) \
- "\n\t.ent " __STRING(entry) \
- "\n\t" __STRING(entry) ":\n\t"
-#endif
-
-#ifndef _RTLD_EPILOGUE
-# define _RTLD_EPILOGUE(entry) "\t.end " __STRING(entry) "\n"
-#endif
-
-/* A reloc type used for ld.so cmdline arg lookups to reject PLT entries.
- This makes no sense on MIPS but we have to define this to R_MIPS_REL32
- to avoid the asserts in dl-lookup.c from blowing. */
-#define ELF_MACHINE_JMP_SLOT R_MIPS_REL32
-#define elf_machine_type_class(type) ELF_RTYPE_CLASS_PLT
-
-/* Translate a processor specific dynamic tag to the index
- in l_info array. */
-#define DT_MIPS(x) (DT_MIPS_##x - DT_LOPROC + DT_NUM)
-
-#if 0
-/* We may need 64k alignment. */
-#define ELF_MACHINE_ALIGN_MASK 0xffff
-#endif
-
-/*
- * MIPS libraries are usually linked to a non-zero base address. We
- * subtrace the base address from the address where we map the object
- * to. This results in more efficient address space usage.
- */
-#if 0
-#define MAP_BASE_ADDR(l) ((l)->l_info[DT_MIPS(BASE_ADDRESS)] ? \
- (l)->l_info[DT_MIPS(BASE_ADDRESS)]->d_un.d_ptr : 0)
-#else
-#define MAP_BASE_ADDR(l) 0x5ffe0000
-#endif
-
-/* If there is a DT_MIPS_RLD_MAP entry in the dynamic section, fill it in
- with the run-time address of the r_debug structure */
-#define ELF_MACHINE_DEBUG_SETUP(l,r) \
-do { if ((l)->l_info[DT_MIPS (RLD_MAP)]) \
- *(ElfW(Addr) *)((l)->l_info[DT_MIPS (RLD_MAP)]->d_un.d_ptr) = \
- (ElfW(Addr)) (r); \
- } while (0)
-
-/* Return nonzero iff ELF header is compatible with the running host. */
-static inline int __attribute__ ((unused))
-elf_machine_matches_host (const ElfW(Ehdr) *ehdr)
-{
- switch (ehdr->e_machine)
- {
- case EM_MIPS:
- case EM_MIPS_RS3_LE:
- return 1;
- default:
- return 0;
- }
-}
-
-static inline ElfW(Addr) *
-elf_mips_got_from_gpreg (ElfW(Addr) gpreg)
-{
- /* FIXME: the offset of gp from GOT may be system-dependent. */
- return (ElfW(Addr) *) (gpreg - 0x7ff0);
-}
-
-/* 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 ElfW(Addr)
-elf_machine_dynamic (void)
-{
- register ElfW(Addr) gp __asm__ ("$28");
-
- return *elf_mips_got_from_gpreg (gp);
-}
-
-
-/* Return the run-time load address of the shared object. */
-static inline ElfW(Addr)
-elf_machine_load_address (void)
-{
- ElfW(Addr) addr;
- asm (" .set noreorder\n"
- " dla %0, here\n"
- " bltzal $0, here\n"
- " nop\n"
- "here: dsubu %0, $31, %0\n"
- " .set reorder\n"
- : "=r" (addr)
- : /* No inputs */
- : "$31");
- return addr;
-}
-
-/* The MSB of got[1] of a gnu object is set to identify gnu objects. */
-#define ELF_MIPS_GNU_GOT1_MASK 0x80000000
-
-/* Relocate GOT. */
-static inline void
-elf_machine_got_rel (struct link_map *map, int lazy)
-{
- ElfW(Addr) *got;
- ElfW(Sym) *sym;
- int i, n;
- const char *strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);
-
-#define RESOLVE_GOTSYM(sym) \
- ({ \
- const ElfW(Sym) *ref = sym; \
- ElfW(Addr) sym_loadaddr; \
- sym_loadaddr = _dl_lookup_symbol (strtab + sym->st_name, &ref, \
- map->l_scope, \
- map->l_name, R_MIPS_REL32);\
- (ref)? sym_loadaddr + ref->st_value: 0; \
- })
-
- got = (ElfW(Addr) *) D_PTR (map, l_info[DT_PLTGOT]);
-
- /* got[0] is reserved. got[1] is also reserved for the dynamic object
- generated by gnu ld. Skip these reserved entries from relocation. */
- i = (got[1] & ELF_MIPS_GNU_GOT1_MASK)? 2: 1;
- n = map->l_info[DT_MIPS (LOCAL_GOTNO)]->d_un.d_val;
- /* Add the run-time display to all local got entries. */
- while (i < n)
- got[i++] += map->l_addr;
-
- /* Handle global got entries. */
- got += n;
- sym = (ElfW(Sym) *) D_PTR (map, l_info[DT_SYMTAB]);
- sym += map->l_info[DT_MIPS (GOTSYM)]->d_un.d_val;
- i = (map->l_info[DT_MIPS (SYMTABNO)]->d_un.d_val
- - map->l_info[DT_MIPS (GOTSYM)]->d_un.d_val);
-
- while (i--)
- {
- if (sym->st_shndx == SHN_UNDEF)
- {
- if (ELFW(ST_TYPE) (sym->st_info) == STT_FUNC)
- {
- if (sym->st_value && lazy)
- *got = sym->st_value + map->l_addr;
- else
- *got = RESOLVE_GOTSYM (sym);
- }
- else /* if (*got == 0 || *got == QS) */
- *got = RESOLVE_GOTSYM (sym);
- }
- else if (sym->st_shndx == SHN_COMMON)
- *got = RESOLVE_GOTSYM (sym);
- else if (ELFW(ST_TYPE) (sym->st_info) == STT_FUNC
- && *got != sym->st_value
- && lazy)
- *got += map->l_addr;
- else if (ELFW(ST_TYPE) (sym->st_info) == STT_SECTION)
- {
- if (sym->st_other == 0)
- *got += map->l_addr;
- }
- else
- *got = RESOLVE_GOTSYM (sym);
-
- got++;
- sym++;
- }
-
-#undef RESOLVE_GOTSYM
-
- return;
-}
-
-/* Set up the loaded object described by L so its stub function
- will jump to the on-demand fixup code in dl-runtime.c. */
-
-static inline int
-elf_machine_runtime_setup (struct link_map *l, int lazy, int profile)
-{
- ElfW(Addr) *got;
- extern void _dl_runtime_resolve (ElfW(Word));
- extern int _dl_mips_gnu_objects;
-
-#ifdef RTLD_BOOTSTRAP
- {
- return lazy;
- }
-#endif
- if (lazy)
- {
- /* The GOT entries for functions have not yet been filled in.
- Their initial contents will arrange when called to put an
- offset into the .dynsym section in t8, the return address
- in t7 and then jump to _GLOBAL_OFFSET_TABLE[0]. */
- got = (ElfW(Addr) *) D_PTR (l, l_info[DT_PLTGOT]);
-
- /* This function will get called to fix up the GOT entry indicated by
- the register t8, and then jump to the resolved address. */
- got[0] = (ElfW(Addr)) &_dl_runtime_resolve;
-
- /* Store l to _GLOBAL_OFFSET_TABLE[1] for gnu object. The MSB
- of got[1] of a gnu object is set to identify gnu objects.
- Where we can store l for non gnu objects? XXX */
- if ((got[1] & ELF_MIPS_GNU_GOT1_MASK) != 0)
- got[1] = (ElfW(Addr)) ((unsigned) l | ELF_MIPS_GNU_GOT1_MASK);
- else
- _dl_mips_gnu_objects = 0;
- }
-
- /* Relocate global offset table. */
- elf_machine_got_rel (l, lazy);
-
- return lazy;
-}
-
-/* Get link_map for this object. */
-static inline struct link_map *
-elf_machine_runtime_link_map (ElfW(Addr) gpreg, ElfW(Addr) stub_pc)
-{
- extern int _dl_mips_gnu_objects;
-
- /* got[1] is reserved to keep its link map address for the shared
- object generated by the gnu linker. If all are such objects, we
- can find the link map from current GPREG simply. If not so, get
- the link map for caller's object containing STUB_PC. */
-
- if (_dl_mips_gnu_objects)
- {
- ElfW(Addr) *got = elf_mips_got_from_gpreg (gpreg);
- ElfW(Word) g1;
-
- g1 = ((ElfW(Word) *) got)[1];
-
- if ((g1 & ELF_MIPS_GNU_GOT1_MASK) != 0)
- {
- struct link_map *l =
- (struct link_map *) (g1 & ~ELF_MIPS_GNU_GOT1_MASK);
- ElfW(Addr) base, limit;
- const ElfW(Phdr) *p = l->l_phdr;
- ElfW(Half) this, nent = l->l_phnum;
-
- /* For the common case of a stub being called from the containing
- object, STUB_PC will point to somewhere within the object that
- is described by the link map fetched via got[1]. Otherwise we
- have to scan all maps. */
- for (this = 0; this < nent; this++)
- {
- if (p[this].p_type == PT_LOAD)
- {
- base = p[this].p_vaddr + l->l_addr;
- limit = base + p[this].p_memsz;
- if (stub_pc >= base && stub_pc < limit)
- return l;
- }
- this++;
- }
- }
- }
-
- {
- struct link_map *l = GL(dl_loaded);
-
- while (l)
- {
- ElfW(Addr) base, limit;
- const ElfW(Phdr) *p = l->l_phdr;
- ElfW(Half) this, nent = l->l_phnum;
-
- for (this = 0; this < nent; this++)
- {
- if (p[this].p_type == PT_LOAD)
- {
- base = p[this].p_vaddr + l->l_addr;
- limit = base + p[this].p_memsz;
- if (stub_pc >= base && stub_pc < limit)
- return l;
- }
- }
- l = l->l_next;
- }
- }
-
- _dl_signal_error (0, NULL, NULL, "cannot find runtime link map");
- return NULL;
-}
-
-/* Mips has no PLT but define elf_machine_relplt to be elf_machine_rel. */
-#define elf_machine_relplt elf_machine_rel
-
-/* Define mips specific runtime resolver. The function __dl_runtime_resolve
- is called from assembler function _dl_runtime_resolve which converts
- special argument registers t7 ($15) and t8 ($24):
- t7 address to return to the caller of the function
- t8 index for this function symbol in .dynsym
- to usual c arguments. */
-
-#define ELF_MACHINE_RUNTIME_TRAMPOLINE \
-/* The flag _dl_mips_gnu_objects is set if all dynamic objects are \
- generated by the gnu linker. */ \
-int _dl_mips_gnu_objects = 1; \
- \
-/* This is called from assembly stubs below which the compiler can't see. */ \
-static ElfW(Addr) \
-__dl_runtime_resolve (ElfW(Word), ElfW(Word), ElfW(Addr), ElfW(Addr)) \
- __attribute__ ((unused)); \
- \
-static ElfW(Addr) \
-__dl_runtime_resolve (ElfW(Word) sym_index, \
- ElfW(Word) return_address, \
- ElfW(Addr) old_gpreg, \
- ElfW(Addr) stub_pc) \
-{ \
- struct link_map *l = elf_machine_runtime_link_map (old_gpreg, stub_pc); \
- const ElfW(Sym) *const symtab \
- = (const ElfW(Sym) *) D_PTR (l, l_info[DT_SYMTAB]); \
- const char *strtab = (const void *) D_PTR (l, l_info[DT_STRTAB]); \
- const ElfW(Addr) *got \
- = (const ElfW(Addr) *) D_PTR (l, l_info[DT_PLTGOT]); \
- const ElfW(Word) local_gotno \
- = (const ElfW(Word)) l->l_info[DT_MIPS (LOCAL_GOTNO)]->d_un.d_val; \
- const ElfW(Word) gotsym \
- = (const ElfW(Word)) l->l_info[DT_MIPS (GOTSYM)]->d_un.d_val; \
- const ElfW(Sym) *definer; \
- ElfW(Addr) loadbase; \
- ElfW(Addr) funcaddr; \
- \
- /* Look up the symbol's run-time value. */ \
- definer = &symtab[sym_index]; \
- \
- loadbase = _dl_lookup_symbol (strtab + definer->st_name, &definer, \
- l->l_scope, l->l_name, \
- R_MIPS_REL32); \
- \
- /* Apply the relocation with that value. */ \
- funcaddr = loadbase + definer->st_value; \
- *(got + local_gotno + sym_index - gotsym) = funcaddr; \
- \
- return funcaddr; \
-} \
- \
-asm ("\n \
- .text\n \
- .align 3\n \
- .globl _dl_runtime_resolve\n \
- .type _dl_runtime_resolve,@function\n \
- .ent _dl_runtime_resolve\n \
-_dl_runtime_resolve:\n \
- .set noreorder\n \
- # Save old GP to $3.\n \
- move $3,$28\n \
- # Modify t9 ($25) so as to point .cpload instruction.\n \
- daddu $25,2*8\n \
- # Compute GP.\n \
- .cpload $25\n \
- .set reorder\n \
- # Save slot call pc.\n \
- move $2, $31\n \
- # Save arguments and sp value in stack.\n \
- dsubu $29, 10*8\n \
- .cprestore 8*8\n \
- sd $15, 9*8($29)\n \
- sd $4, 3*8($29)\n \
- sd $5, 4*8($29)\n \
- sd $6, 5*8($29)\n \
- sd $7, 6*8($29)\n \
- sd $16, 7*8($29)\n \
- move $16, $29\n \
- move $4, $24\n \
- move $5, $15\n \
- move $6, $3\n \
- move $7, $2\n \
- jal __dl_runtime_resolve\n \
- move $29, $16\n \
- ld $31, 9*8($29)\n \
- ld $4, 3*8($29)\n \
- ld $5, 4*8($29)\n \
- ld $6, 5*8($29)\n \
- ld $7, 6*8($29)\n \
- ld $16, 7*8($29)\n \
- daddu $29, 10*8\n \
- move $25, $2\n \
- jr $25\n \
- .end _dl_runtime_resolve\n \
- .previous\n \
-");
-
-/* 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.
- Note how we have to be careful about two things:
-
- 1) That we allocate a minimal stack of 24 bytes for
- every function call, the MIPS ABI states that even
- if all arguments are passed in registers the procedure
- called can use the 16 byte area pointed to by $sp
- when it is called to store away the arguments passed
- to it.
-
- 2) That under Linux the entry is named __start
- and not just plain _start. */
-
-#define RTLD_START asm ("\
- .text\n\
- .align 3\n"\
-_RTLD_PROLOGUE (ENTRY_POINT)\
-" .globl _dl_start_user\n\
- .set noreorder\n\
- bltzal $0, 0f\n\
- nop\n\
-0: .cpload $31\n\
- .set reorder\n\
- # i386 ABI book says that the first entry of GOT holds\n\
- # the address of the dynamic structure. Though MIPS ABI\n\
- # doesn't say nothing about this, I emulate this here.\n\
- dla $4, _DYNAMIC\n\
- sd $4, -0x7ff0($28)\n\
- dsubu $29, 16\n\
- move $4, $29\n\
- jal _dl_start\n\
- daddiu $29, 16\n\
- # Get the value of label '_dl_start_user' in t9 ($25).\n\
- dla $25, _dl_start_user\n\
-_dl_start_user:\n\
- .set noreorder\n\
- .cpload $25\n\
- .set reorder\n\
- move $16, $28\n\
- # Save the user entry point address in saved register.\n\
- move $17, $2\n\
- # Store the highest stack address\n\
- sd $29, __libc_stack_end\n\
- # See if we were run as a command with the executable file\n\
- # name as an extra leading argument.\n\
- ld $2, _dl_skip_args\n\
- beq $2, $0, 1f\n\
- # Load the original argument count.\n\
- ld $4, 0($29)\n\
- # Subtract _dl_skip_args from it.\n\
- dsubu $4, $2\n\
- # Adjust the stack pointer to skip _dl_skip_args words.\n\
- dsll $2,2\n\
- daddu $29, $2\n\
- # Save back the modified argument count.\n\
- sd $4, 0($29)\n\
-1: # Call _dl_init (struct link_map *main_map, int argc, char **argv, char **env) \n\
- ld $4, _rtld_local\n\
- ld $5, 0($29)\n\
- dla $6, 4($29)\n\
- dla $7, 8($29)\n\
- dsubu $29, 16\n\
- # Call the function to run the initializers.\n\
- jal _dl_init_internal\n\
- daddiu $29, 16\n\
- # Pass our finalizer function to the user in ra.\n\
- dla $31, _dl_fini\n\
- # Jump to the user entry point.\n\
-1: # Call _dl_init (struct link_map *main_map, int argc, char **argv, char **env) \n\
- lw $4, _rtld_local\n\
- lw $5, 0($29)\n\
- la $6, 4($29)\n\
- la $7, 8($29)\n\
- subu $29, 16\n\
- # Call the function to run the initializers.\n\
- jal _dl_init_internal\n\
- addiu $29, 16\n\
- # Pass our finalizer function to the user in ra.\n\
- dla $31, _dl_fini\n\
- # Jump to the user entry point.\n\
- move $25, $17\n\
- ld $4, 0($29)\n\
- ld $5, 1*8($29)\n\
- ld $6, 2*8$29)\n\
- ld $7, 3*8($29)\n\
- jr $25\n"\
-_RTLD_EPILOGUE(ENTRY_POINT) \
- "\n.previous"\
-);
-
-
-/* The MIPS never uses Elfxx_Rela relocations. */
-#define ELF_MACHINE_NO_RELA 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_rel (struct link_map *map, const ElfW(Rel) *reloc,
- const ElfW(Sym) *sym, const struct r_found_version *version,
- ElfW(Addr) *const reloc_addr)
-{
- const unsigned long int r_type = ELFW(R_TYPE) (reloc->r_info);
- ElfW(Addr) loadbase;
- ElfW(Addr) undo __attribute__ ((unused));
-
- switch (r_type)
- {
- case R_MIPS_REL32:
- {
- ElfW(Addr) undo = 0;
-
- if (ELFW(ST_BIND) (sym->st_info) == STB_LOCAL
- && (ELFW(ST_TYPE) (sym->st_info) == STT_SECTION
- || ELFW(ST_TYPE) (sym->st_info) == STT_NOTYPE))
- {
- *reloc_addr += map->l_addr;
- break;
- }
-#ifndef RTLD_BOOTSTRAP
- /* This is defined in rtld.c, but nowhere in the static libc.a;
- make the reference weak so static programs can still link. This
- declaration cannot be done when compiling rtld.c (i.e. #ifdef
- RTLD_BOOTSTRAP) because rtld.c contains the common defn for
- _dl_rtld_map, which is incompatible with a weak decl in the same
- file. */
-# ifndef SHARED
- weak_extern (GL(dl_rtld_map));
-# endif
- if (map == &GL(dl_rtld_map))
- /* Undo the relocation done here during bootstrapping. Now we will
- relocate it anew, possibly using a binding found in the user
- program or a loaded library rather than the dynamic linker's
- built-in definitions used while loading those libraries. */
- undo = map->l_addr + sym->st_value;
-#endif
- loadbase = RESOLVE (&sym, version, 0);
- *reloc_addr += (sym ? (loadbase + sym->st_value) : 0) - undo;
- }
- break;
-#ifndef RTLD_BOOTSTRAP
- case R_MIPS_NONE: /* Alright, Wilbur. */
- break;
-#endif
- default:
- _dl_reloc_bad_type (map, r_type, 0);
- break;
- }
-}
-
-static inline void
-elf_machine_rel_relative (ElfW(Addr) l_addr, const ElfW(Rel) *reloc,
- ElfW(Addr) *const reloc_addr)
-{
- /* XXX Nothing to do. There is no relative relocation, right? */
-}
-
-static inline void
-elf_machine_lazy_rel (struct link_map *map, ElfW(Addr) l_addr,
- const ElfW(Rel) *reloc)
-{
- /* Do nothing. */
-}
-
-#endif /* RESOLVE */
Index: sysdeps/mips/dl-machine.h
===================================================================
RCS file: /cvs/glibc/libc/sysdeps/mips/dl-machine.h,v
retrieving revision 1.65
diff -u -p -r1.65 dl-machine.h
--- sysdeps/mips/dl-machine.h 12 Feb 2003 09:42:48 -0000 1.65
+++ sysdeps/mips/dl-machine.h 14 Mar 2003 07:43:38 -0000
@@ -32,6 +32,8 @@
#error ENTRY_POINT needs to be defined for MIPS.
#endif
+#include <sys/asm.h>
+
/* The offset of gp from GOT might be system-dependent. It's set by
ld. The same value is also */
#define OFFSET_GP_GOT 0x7ff0
@@ -72,6 +74,13 @@ do { if ((l)->l_info[DT_MIPS (RLD_MAP)])
static inline int __attribute_used__
elf_machine_matches_host (const ElfW(Ehdr) *ehdr)
{
+#if _MIPS_SIM == _MIPS_SIM_ABI32 || _MIPS_SIM == _MIPS_SIM_NABI32
+ /* Don't link o32 and n32 together. */
+ if (((ehdr->e_flags & EF_MIPS_ABI2) != 0)
+ != (_MIPS_SIM != _MIPS_SIM_ABI32))
+ return 0;
+#endif
+
switch (ehdr->e_machine)
{
case EM_MIPS:
@@ -91,7 +100,7 @@ elf_mips_got_from_gpreg (ElfW(Addr) gpre
/* 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. */
+ uses global data. We assume its $gp points to the primary GOT. */
static inline ElfW(Addr)
elf_machine_dynamic (void)
{
@@ -99,6 +108,9 @@ elf_machine_dynamic (void)
return *elf_mips_got_from_gpreg (gp);
}
+#define STRINGXP(X) __STRING(X)
+#define STRINGXV(X) STRINGV_(X)
+#define STRINGV_(...) # __VA_ARGS__
/* Return the run-time load address of the shared object. */
static inline ElfW(Addr)
@@ -106,10 +118,10 @@ elf_machine_load_address (void)
{
ElfW(Addr) addr;
asm (" .set noreorder\n"
- " la %0, here\n"
- " bltzal $0, here\n"
+ " " STRINGXP (PTR_LA) " %0, 0f\n"
+ " bltzal $0, 0f\n"
" nop\n"
- "here: subu %0, $31, %0\n"
+ "0: " STRINGXP (PTR_SUBU) " %0, $31, %0\n"
" .set reorder\n"
: "=r" (addr)
: /* No inputs */
@@ -242,6 +254,55 @@ elf_machine_runtime_link_map (ElfW(Addr)
return NULL;
}
+#if _MIPS_SIM == _MIPS_SIM_ABI32
+#define ELF_DL_FRAME_SIZE 40
+
+#define ELF_DL_SAVE_ARG_REGS "\
+ sw $15, 36($29)\n \
+ sw $4, 16($29)\n \
+ sw $5, 20($29)\n \
+ sw $6, 24($29)\n \
+ sw $7, 28($29)\n \
+"
+
+#define ELF_DL_RESTORE_ARG_REGS "\
+ lw $31, 36($29)\n \
+ lw $4, 16($29)\n \
+ lw $5, 20($29)\n \
+ lw $6, 24($29)\n \
+ lw $7, 28($29)\n \
+"
+
+#define IFABIO32(X) X
+
+#else /* _MIPS_SIM == _MIPS_SIM_NABI32 || _MIPS_SIM == _MIPS_SIM_ABI64 */
+
+#define ELF_DL_FRAME_SIZE 64
+
+#define ELF_DL_SAVE_ARG_REGS "\
+ sd $15, 56($29)\n \
+ sd $4, 8($29)\n \
+ sd $5, 16($29)\n \
+ sd $6, 24($29)\n \
+ sd $7, 32($29)\n \
+ sd $8, 40($29)\n \
+ sd $9, 48($29)\n \
+"
+
+#define ELF_DL_RESTORE_ARG_REGS "\
+ ld $31, 56($29)\n \
+ ld $4, 8($29)\n \
+ ld $5, 16($29)\n \
+ ld $6, 24($29)\n \
+ ld $7, 32($29)\n \
+ ld $8, 40($29)\n \
+ ld $9, 48($29)\n \
+"
+
+#define IFABIO32(X)
+
+#endif
+
/* Define mips specific runtime resolver. The function __dl_runtime_resolve
is called from assembler function _dl_runtime_resolve which converts
special argument registers t7 ($15) and t8 ($24):
@@ -272,9 +333,8 @@ __dl_runtime_resolve (ElfW(Word) sym_ind
{ \
struct link_map *l = elf_machine_runtime_link_map (old_gpreg, stub_pc); \
const ElfW(Sym) *const symtab \
- = (const void *) D_PTR (l, l_info[DT_SYMTAB]); \
- const char *strtab \
- = (const void *) D_PTR (l, l_info[DT_STRTAB]); \
+ = (const ElfW(Sym) *) D_PTR (l, l_info[DT_SYMTAB]); \
+ const char *strtab = (const void *) D_PTR (l, l_info[DT_STRTAB]); \
ElfW(Addr) *got \
= (ElfW(Addr) *) D_PTR (l, l_info[DT_PLTGOT]); \
const ElfW(Word) local_gotno \
@@ -333,36 +393,30 @@ asm ("\n \
.type _dl_runtime_resolve,@function\n \
.ent _dl_runtime_resolve\n \
_dl_runtime_resolve:\n \
- .frame $29, 40, $31\n \
+ .frame $29, " STRINGXP(ELF_DL_FRAME_SIZE) ", $31\n \
.set noreorder\n \
# Save GP.\n \
move $3, $28\n \
+ # Save arguments and sp value in stack.\n \
+ " STRINGXP(PTR_SUBIU) " $29, " STRINGXP(ELF_DL_FRAME_SIZE) "\n \
# Modify t9 ($25) so as to point .cpload instruction.\n \
- addu $25, 8\n \
+ " IFABIO32(STRINGXP(PTR_ADDIU) " $25, 12\n") " \
# Compute GP.\n \
- .cpload $25\n \
+ " STRINGXP(SETUP_GP) "\n \
+ " STRINGXV(SETUP_GP64 (0, _dl_runtime_resolve)) "\n \
.set reorder\n \
# Save slot call pc.\n \
move $2, $31\n \
- # Save arguments and sp value in stack.\n \
- subu $29, 40\n \
- .cprestore 32\n \
- sw $15, 36($29)\n \
- sw $4, 16($29)\n \
- sw $5, 20($29)\n \
- sw $6, 24($29)\n \
- sw $7, 28($29)\n \
+ " IFABIO32(STRINGXP(CPRESTORE(32))) "\n \
+ " ELF_DL_SAVE_ARG_REGS " \
move $4, $24\n \
move $5, $15\n \
move $6, $3\n \
move $7, $2\n \
jal __dl_runtime_resolve\n \
- lw $31, 36($29)\n \
- lw $4, 16($29)\n \
- lw $5, 20($29)\n \
- lw $6, 24($29)\n \
- lw $7, 28($29)\n \
- addu $29, 40\n \
+ " ELF_DL_RESTORE_ARG_REGS " \
+ " STRINGXP(RESTORE_GP64) "\n \
+ " STRINGXP(PTR_ADDIU) " $29, " STRINGXP(ELF_DL_FRAME_SIZE) "\n \
move $25, $2\n \
jr $25\n \
.end _dl_runtime_resolve\n \
@@ -374,7 +428,6 @@ _dl_runtime_resolve:\n \
#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.
@@ -392,71 +445,71 @@ _dl_runtime_resolve:\n \
#define RTLD_START asm (\
".text\n"\
- _RTLD_PROLOGUE(ENTRY_POINT)\
- ".set noreorder\n\
- bltzal $0, 0f\n\
- nop\n\
-0: .cpload $31\n\
- .set reorder\n\
+ _RTLD_PROLOGUE(ENTRY_POINT) "\
+ " STRINGXV(SETUP_GPX($25)) "\n\
+ " STRINGXV(SETUP_GPX64($18,$25)) "\n\
# i386 ABI book says that the first entry of GOT holds\n\
# the address of the dynamic structure. Though MIPS ABI\n\
# doesn't say nothing about this, I emulate this here.\n\
- la $4, _DYNAMIC\n\
+ " STRINGXP(PTR_LA) " $4, _DYNAMIC\n\
# Subtract OFFSET_GP_GOT\n\
- sw $4, -0x7ff0($28)\n\
+ " STRINGXP(PTR_S) " $4, -0x7ff0($28)\n\
move $4, $29\n\
- subu $29, 16\n\
+ " STRINGXP(PTR_SUBIU) " $29, 16\n\
\n\
- la $8, coff\n\
- bltzal $8, coff\n\
-coff: subu $8, $31, $8\n\
+ " STRINGXP(PTR_LA) " $8, .Lcoff\n\
+ bltzal $8, .Lcoff\n\
+.Lcoff: " STRINGXP(PTR_SUBU) " $8, $31, $8\n\
\n\
- la $25, _dl_start\n\
- addu $25, $8\n\
+ " STRINGXP(PTR_LA) " $25, _dl_start\n\
+ " STRINGXP(PTR_ADDU) " $25, $8\n\
jalr $25\n\
\n\
- addiu $29, 16\n\
+ " STRINGXP(PTR_ADDIU) " $29, 16\n\
# Get the value of label '_dl_start_user' in t9 ($25).\n\
- la $25, _dl_start_user\n\
+ " STRINGXP(PTR_LA) " $25, _dl_start_user\n\
.globl _dl_start_user\n\
+ .type _dl_start_user,@function\n\
+ .ent _dl_start_user\n\
_dl_start_user:\n\
- .set noreorder\n\
- .cpload $25\n\
- .set reorder\n\
+ " STRINGXP(SETUP_GP) "\n\
+ " STRINGXV(SETUP_GP64($18,_dl_start_user)) "\n\
move $16, $28\n\
# Save the user entry point address in a saved register.\n\
move $17, $2\n\
# Store the highest stack address\n\
- sw $29, __libc_stack_end\n\
+ " STRINGXP(PTR_S) " $29, __libc_stack_end\n\
# See if we were run as a command with the executable file\n\
# name as an extra leading argument.\n\
lw $2, _dl_skip_args\n\
beq $2, $0, 1f\n\
# Load the original argument count.\n\
- lw $4, 0($29)\n\
+ " STRINGXP(PTR_L) " $4, 0($29)\n\
# Subtract _dl_skip_args from it.\n\
subu $4, $2\n\
# Adjust the stack pointer to skip _dl_skip_args words.\n\
- sll $2, 2\n\
- addu $29, $2\n\
+ sll $2, " STRINGXP (PTRLOG) "\n\
+ " STRINGXP(PTR_ADDU) " $29, $2\n\
# Save back the modified argument count.\n\
- sw $4, 0($29)\n\
+ " STRINGXP(PTR_S) " $4, 0($29)\n\
1: # Call _dl_init (struct link_map *main_map, int argc, char **argv, char **env) \n\
- lw $4, _rtld_local\n\
- lw $5, 0($29)\n\
- la $6, 4($29)\n\
- sll $7, $5, 2\n\
- addu $7, $7, $6\n\
- addu $7, $7, 4\n\
- subu $29, 16\n\
+ " STRINGXP(PTR_L) " $4, _rtld_local\n\
+ " STRINGXP(PTR_L) /* or lw??? fixme */ " $5, 0($29)\n\
+ " STRINGXP(PTR_LA) " $6, " STRINGXP (PTRSIZE) "($29)\n\
+ sll $7, $5, " STRINGXP (PTRLOG) "\n\
+ " STRINGXP(PTR_ADDU) " $7, $7, $6\n\
+ " STRINGXP(PTR_ADDU) " $7, $7, " STRINGXP (PTRSIZE) " \n\
+ " STRINGXP(PTR_SUBIU) " $29, 32\n\
+ " STRINGXP(SAVE_GP(16)) "\n\
# Call the function to run the initializers.\n\
jal _dl_init_internal\n\
- addiu $29, 16\n\
+ " STRINGXP(PTR_ADDIU) " $29, 32\n\
# Pass our finalizer function to the user in $2 as per ELF ABI.\n\
- la $2, _dl_fini\n\
+ " STRINGXP(PTR_LA) " $2, _dl_fini\n\
# Jump to the user entry point.\n\
move $25, $17\n\
- jr $25\n\t"\
+ jr $25\n\
+ .end _dl_start_user\n\t"\
_RTLD_EPILOGUE(ENTRY_POINT)\
".previous"\
);
@@ -472,6 +525,9 @@ _dl_start_user:\n\
MAP is the object containing the reloc. */
static inline void
+#ifdef RTLD_BOOTSTRAP
+ __attribute__ ((always_inline))
+#endif
elf_machine_rel (struct link_map *map, const ElfW(Rel) *reloc,
const ElfW(Sym) *sym, const struct r_found_version *version,
ElfW(Addr) *const reloc_addr)
@@ -490,9 +546,19 @@ elf_machine_rel (struct link_map *map, c
switch (r_type)
{
+#if _MIPS_SIM == _MIPS_SIM_ABI64
+ case (R_MIPS_64 << 8) | R_MIPS_REL32:
+#else
case R_MIPS_REL32:
+#endif
{
int symidx = ELFW(R_SYM) (reloc->r_info);
+ ElfW(Addr) reloc_value;
+
+ /* Support relocations on mis-aligned offsets. Should we ever
+ implement RELA, this should be replaced with an assignment
+ from reloc->r_addend. */
+ __builtin_memcpy (&reloc_value, reloc_addr, sizeof (reloc_value));
if (symidx)
{
@@ -501,10 +567,25 @@ elf_machine_rel (struct link_map *map, c
if (symidx < gotsym)
{
+ /* This wouldn't work for a symbol imported from other
+ libraries for which there's no GOT entry, but MIPS
+ requires every symbol referenced in a dynamic
+ relocation to have a GOT entry in the primary GOT,
+ so we only get here for locally-defined symbols.
+ For section symbols, we should *NOT* be adding
+ sym->st_value (per the definition of the meaning of
+ S in reloc expressions in the ELF64 MIPS ABI),
+ since it should have already been added to
+ reloc_value by the linker, but older versions of
+ GNU ld didn't add it, and newer versions don't emit
+ useless relocations to section symbols any more, so
+ it is safe to keep on adding sym->st_value, even
+ though it's not ABI compliant. Some day we should
+ bite the bullet and stop doing this. */
#ifndef RTLD_BOOTSTRAP
if (map != &GL(dl_rtld_map))
#endif
- *reloc_addr += sym->st_value + map->l_addr;
+ reloc_value += sym->st_value + map->l_addr;
}
else
{
@@ -515,7 +596,7 @@ elf_machine_rel (struct link_map *map, c
= (const ElfW(Word))
map->l_info[DT_MIPS (LOCAL_GOTNO)]->d_un.d_val;
- *reloc_addr += got[symidx + local_gotno - gotsym];
+ reloc_value += got[symidx + local_gotno - gotsym];
#endif
}
}
@@ -523,11 +604,27 @@ elf_machine_rel (struct link_map *map, c
#ifndef RTLD_BOOTSTRAP
if (map != &GL(dl_rtld_map))
#endif
- *reloc_addr += map->l_addr;
+ reloc_value += map->l_addr;
+
+ __builtin_memcpy (reloc_addr, &reloc_value, sizeof (reloc_value));
}
break;
case R_MIPS_NONE: /* Alright, Wilbur. */
break;
+#if _MIPS_SIM == _MIPS_SIM_ABI64
+ case R_MIPS_64:
+ /* For full compliance with the ELF64 ABI, one must precede the
+ _REL32/_64 pair of relocations with a _64 relocation, such
+ that the in-place addend is read as a 64-bit value. IRIX
+ didn't pick up on this requirement, so we treat the
+ _REL32/_64 relocation as a 64-bit relocation even if it's by
+ itself. For ABI compliance, we ignore such _64 dummy
+ relocations. For RELA, this may be simply removed, since
+ it's totally unnecessary. */
+ if (ELFW(R_SYM) (reloc->r_info) == 0)
+ break;
+ /* Fall through. */
+#endif
default:
_dl_reloc_bad_type (map, r_type, 0);
break;
--
Alexandre Oliva Enjoy Guarana', see http://www.ic.unicamp.br/~oliva/
Red Hat GCC Developer aoliva at {redhat dot com, gcc.gnu.org}
CS PhD student at IC-Unicamp oliva at {lsd dot ic dot unicamp dot br, gnu.org}
Free Software Evangelist Professional serial bug killer