From 365eccdb099f7cff2fdc589bef7be7806a4bc9c7 Mon Sep 17 00:00:00 2001 From: Alexandre Oliva Date: Fri, 14 Mar 2003 08:43:13 +0000 Subject: * 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. * 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. --- sysdeps/mips/dl-machine.h | 221 +++++++++++++++++++++++++++++++++------------- 1 file changed, 159 insertions(+), 62 deletions(-) (limited to 'sysdeps/mips/dl-machine.h') diff --git a/sysdeps/mips/dl-machine.h b/sysdeps/mips/dl-machine.h index c4864c21d2..62c3f20736 100644 --- a/sysdeps/mips/dl-machine.h +++ b/sysdeps/mips/dl-machine.h @@ -32,6 +32,8 @@ #error ENTRY_POINT needs to be defined for MIPS. #endif +#include + /* 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) gpreg) /* 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) gpreg, ElfW(Addr) stub_pc) 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_index, \ { \ 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, const ElfW(Rel) *reloc, 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, const ElfW(Rel) *reloc, 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, const ElfW(Rel) *reloc, = (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, const ElfW(Rel) *reloc, #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; -- cgit v1.2.3