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Diffstat (limited to 'sysdeps/mips/dl-machine.h')
| -rw-r--r-- | sysdeps/mips/dl-machine.h | 777 |
1 files changed, 777 insertions, 0 deletions
diff --git a/sysdeps/mips/dl-machine.h b/sysdeps/mips/dl-machine.h new file mode 100644 index 0000000000..0d87b65691 --- /dev/null +++ b/sysdeps/mips/dl-machine.h @@ -0,0 +1,777 @@ +/* Machine-dependent ELF dynamic relocation inline functions. MIPS version. + Copyright (C) 1996-2001, 2002, 2003, 2004 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Kazumoto Kojima <kkojima@info.kanagawa-u.ac.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. */ + +/* FIXME: Profiling of shared libraries is not implemented yet. */ +#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 + +#include <sgidefs.h> +#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 + +#ifndef _RTLD_PROLOGUE +# define _RTLD_PROLOGUE(entry) \ + ".globl\t" __STRING(entry) "\n\t" \ + ".ent\t" __STRING(entry) "\n\t" \ + ".type\t" __STRING(entry) ", @function\n" \ + __STRING(entry) ":\n\t" +#endif + +#ifndef _RTLD_EPILOGUE +# define _RTLD_EPILOGUE(entry) \ + ".end\t" __STRING(entry) "\n\t" \ + ".size\t" __STRING(entry) ", . - " __STRING(entry) "\n\t" +#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 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_used__ +elf_machine_matches_host (const ElfW(Ehdr) *ehdr) +{ +#if _MIPS_SIM == _ABIO32 || _MIPS_SIM == _ABIN32 + /* Don't link o32 and n32 together. */ + if (((ehdr->e_flags & EF_MIPS_ABI2) != 0) != (_MIPS_SIM == _ABIN32)) + return 0; +#endif + + 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 - OFFSET_GP_GOT); +} + +/* 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. We assume its $gp points to the primary GOT. */ +static inline ElfW(Addr) +elf_machine_dynamic (void) +{ + register ElfW(Addr) gp __asm__ ("$28"); + 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) +elf_machine_load_address (void) +{ + ElfW(Addr) addr; + asm (" .set noreorder\n" + " " STRINGXP (PTR_LA) " %0, 0f\n" + " bltzal $0, 0f\n" + " nop\n" + "0: " STRINGXP (PTR_SUBU) " %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. */ +#if _MIPS_SIM == _ABI64 +# define ELF_MIPS_GNU_GOT1_MASK 0x8000000000000000L +#else +# define ELF_MIPS_GNU_GOT1_MASK 0x80000000L +#endif + +/* We can't rely on elf_machine_got_rel because _dl_object_relocation_scope + fiddles with global data. */ +#define ELF_MACHINE_BEFORE_RTLD_RELOC(dynamic_info) \ +do { \ + struct link_map *map = &bootstrap_map; \ + ElfW(Sym) *sym; \ + ElfW(Addr) *got; \ + int i, n; \ + \ + got = (ElfW(Addr) *) D_PTR (map, l_info[DT_PLTGOT]); \ + \ + if (__builtin_expect (map->l_addr == 0, 1)) \ + break; \ + \ + /* 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 displacement 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]) \ + + 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 || sym->st_shndx == SHN_COMMON) \ + *got = map->l_addr + sym->st_value; \ + else if (ELFW(ST_TYPE) (sym->st_info) == STT_FUNC \ + && *got != sym->st_value) \ + *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 = map->l_addr + sym->st_value; \ + \ + got++; \ + sym++; \ + } \ +} while(0) + + +/* Get link map for callers object containing STUB_PC. */ +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; + } + } + } + } + + struct link_map *l; + Lmid_t nsid; + + for (nsid = 0; nsid < DL_NNS; ++nsid) + for (l = GL(dl_ns)[nsid]._ns_loaded; l != NULL; l = l->l_next) + { + 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; + } + } + } + + _dl_signal_error (0, NULL, NULL, "cannot find runtime link map"); + return NULL; +} + +#if _MIPS_SIM == _ABIO32 +#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 == _ABIN32 || _MIPS_SIM == _ABI64 */ + +#define ELF_DL_FRAME_SIZE 80 + +#define ELF_DL_SAVE_ARG_REGS "\ + sd $15, 72($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 \ + sd $10, 56($29)\n \ + sd $11, 64($29)\n \ +" + +#define ELF_DL_RESTORE_ARG_REGS "\ + ld $31, 72($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 \ + ld $10, 56($29)\n \ + ld $11, 64($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): + t7 address to return to the caller of the function + t8 index for this function symbol in .dynsym + to usual c arguments. + + Other architectures call fixup from dl-runtime.c in + _dl_runtime_resolve. MIPS instead calls __dl_runtime_resolve. We + have to use our own version because of the way the got section is + treated on MIPS (we've also got ELF_MACHINE_PLT defined). */ + +#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_used__; \ + \ +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]); \ + ElfW(Addr) *got \ + = (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) *sym = &symtab[sym_index]; \ + ElfW(Addr) value; \ + \ + /* FIXME: The symbol versioning stuff is not tested yet. */ \ + if (__builtin_expect (ELFW(ST_VISIBILITY) (sym->st_other), 0) == 0) \ + { \ + switch (l->l_info[VERSYMIDX (DT_VERSYM)] != NULL) \ + { \ + default: \ + { \ + const ElfW(Half) *vernum = \ + (const void *) D_PTR (l, l_info[VERSYMIDX (DT_VERSYM)]); \ + ElfW(Half) ndx = vernum[sym_index] & 0x7fff; \ + const struct r_found_version *version = &l->l_versions[ndx]; \ + \ + if (version->hash != 0) \ + { \ + value = _dl_lookup_symbol_x (strtab + sym->st_name, l, \ + &sym, l->l_scope, version, \ + ELF_RTYPE_CLASS_PLT, 0, 0); \ + break; \ + } \ + /* Fall through. */ \ + } \ + case 0: \ + value = _dl_lookup_symbol_x (strtab + sym->st_name, l, &sym, \ + l->l_scope, 0, ELF_RTYPE_CLASS_PLT, \ + DL_LOOKUP_ADD_DEPENDENCY, 0); \ + } \ + \ + /* Currently value contains the base load address of the object \ + that defines sym. Now add in the symbol offset. */ \ + value = (sym ? value + sym->st_value : 0); \ + } \ + else \ + /* We already found the symbol. The module (and therefore its load \ + address) is also known. */ \ + value = l->l_addr + sym->st_value; \ + \ + /* Apply the relocation with that value. */ \ + *(got + local_gotno + sym_index - gotsym) = value; \ + \ + return value; \ +} \ + \ +asm ("\n \ + .text\n \ + .align 2\n \ + .globl _dl_runtime_resolve\n \ + .type _dl_runtime_resolve,@function\n \ + .ent _dl_runtime_resolve\n \ +_dl_runtime_resolve:\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 \ + " IFABIO32(STRINGXP(PTR_ADDIU) " $25, 12\n") " \ + # Compute GP.\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 \ + " 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 \ + " 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 \ + .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"\ + _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\ + " STRINGXP(PTR_LA) " $4, _DYNAMIC\n\ + # Subtract OFFSET_GP_GOT\n\ + " STRINGXP(PTR_S) " $4, -0x7ff0($28)\n\ + move $4, $29\n\ + " STRINGXP(PTR_SUBIU) " $29, 16\n\ + \n\ + " STRINGXP(PTR_LA) " $8, .Lcoff\n\ + bltzal $8, .Lcoff\n\ +.Lcoff: " STRINGXP(PTR_SUBU) " $8, $31, $8\n\ + \n\ + " STRINGXP(PTR_LA) " $25, _dl_start\n\ + " STRINGXP(PTR_ADDU) " $25, $8\n\ + jalr $25\n\ + \n\ + " STRINGXP(PTR_ADDIU) " $29, 16\n\ + # Get the value of label '_dl_start_user' in t9 ($25).\n\ + " STRINGXP(PTR_LA) " $25, _dl_start_user\n\ + .globl _dl_start_user\n\ + .type _dl_start_user,@function\n\ + .aent _dl_start_user\n\ +_dl_start_user:\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\ + # 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\ + " 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, " STRINGXP (PTRLOG) "\n\ + " STRINGXP(PTR_ADDU) " $29, $2\n\ + # Save back the modified argument count.\n\ + " STRINGXP(PTR_S) " $4, 0($29)\n\ +1: # Call _dl_init (struct link_map *main_map, int argc, char **argv, char **env) \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\ + " STRINGXP(PTR_ADDIU) " $29, 32\n\ + # Pass our finalizer function to the user in $2 as per ELF ABI.\n\ + " STRINGXP(PTR_LA) " $2, _dl_fini\n\ + # Jump to the user entry point.\n\ + move $25, $17\n\ + jr $25\n\t"\ + _RTLD_EPILOGUE(ENTRY_POINT)\ + ".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 +#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, + void *const reloc_addr) +{ + const unsigned long int r_type = ELFW(R_TYPE) (reloc->r_info); + +#if !defined RTLD_BOOTSTRAP && !defined SHARED + /* 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. */ + weak_extern (GL(dl_rtld_map)); +#endif + + switch (r_type) + { +#if _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) + { + const ElfW(Word) gotsym + = (const ElfW(Word)) map->l_info[DT_MIPS (GOTSYM)]->d_un.d_val; + + if ((ElfW(Word))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_value += sym->st_value + map->l_addr; + } + else + { +#ifndef RTLD_BOOTSTRAP + const ElfW(Addr) *got + = (const ElfW(Addr) *) D_PTR (map, l_info[DT_PLTGOT]); + const ElfW(Word) local_gotno + = (const ElfW(Word)) + map->l_info[DT_MIPS (LOCAL_GOTNO)]->d_un.d_val; + + reloc_value += got[symidx + local_gotno - gotsym]; +#endif + } + } + else +#ifndef RTLD_BOOTSTRAP + if (map != &GL(dl_rtld_map)) +#endif + 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 == _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; + } +} + +static inline void +elf_machine_rel_relative (ElfW(Addr) l_addr, const ElfW(Rel) *reloc, + void *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. */ +} + +#ifndef RTLD_BOOTSTRAP +/* Relocate GOT. */ +static inline void +elf_machine_got_rel (struct link_map *map, int lazy) +{ + ElfW(Addr) *got; + ElfW(Sym) *sym; + const ElfW(Half) *vernum; + int i, n, symidx; + +#define RESOLVE_GOTSYM(sym,vernum,sym_index) \ + ({ \ + const ElfW(Sym) *ref = sym; \ + const struct r_found_version *version \ + = vernum ? &map->l_versions[vernum[sym_index] & 0x7fff] : NULL; \ + ElfW(Addr) value; \ + value = RESOLVE (&ref, version, R_MIPS_REL32); \ + (ref)? value + ref->st_value: 0; \ + }) + + if (map->l_info[VERSYMIDX (DT_VERSYM)] != NULL) + vernum = (const void *) D_PTR (map, l_info[VERSYMIDX (DT_VERSYM)]); + else + vernum = NULL; + + got = (ElfW(Addr) *) D_PTR (map, l_info[DT_PLTGOT]); + + n = map->l_info[DT_MIPS (LOCAL_GOTNO)]->d_un.d_val; + /* The dynamic linker's local got entries have already been relocated. */ + if (map != &GL(dl_rtld_map)) + { + /* 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; + + /* Add the run-time displacement to all local got entries if + needed. */ + if (__builtin_expect (map->l_addr != 0, 0)) + { + while (i < n) + got[i++] += map->l_addr; + } + } + + /* Handle global got entries. */ + got += n; + /* Keep track of the symbol index. */ + symidx = map->l_info[DT_MIPS (GOTSYM)]->d_un.d_val; + sym = (ElfW(Sym) *) D_PTR (map, l_info[DT_SYMTAB]) + symidx; + i = (map->l_info[DT_MIPS (SYMTABNO)]->d_un.d_val + - map->l_info[DT_MIPS (GOTSYM)]->d_un.d_val); + + /* This loop doesn't handle Quickstart. */ + while (i--) + { + if (sym->st_shndx == SHN_UNDEF) + { + if (ELFW(ST_TYPE) (sym->st_info) == STT_FUNC + && sym->st_value && lazy) + *got = sym->st_value + map->l_addr; + else + *got = RESOLVE_GOTSYM (sym, vernum, symidx); + } + else if (sym->st_shndx == SHN_COMMON) + *got = RESOLVE_GOTSYM (sym, vernum, symidx); + 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, vernum, symidx); + + ++got; + ++sym; + ++symidx; + } + +#undef RESOLVE_GOTSYM +} +#endif + +/* Set up the loaded object described by L so its stub function + will jump to the on-demand fixup code __dl_runtime_resolve. */ + +static inline int +elf_machine_runtime_setup (struct link_map *l, int lazy, int profile) +{ +# ifndef RTLD_BOOTSTRAP + ElfW(Addr) *got; + extern void _dl_runtime_resolve (ElfW(Word)); + extern int _dl_mips_gnu_objects; + + 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)) l | ELF_MIPS_GNU_GOT1_MASK); + else + _dl_mips_gnu_objects = 0; + } + + /* Relocate global offset table. */ + elf_machine_got_rel (l, lazy); + +# endif + return lazy; +} + +#endif /* RESOLVE */ |