diff options
Diffstat (limited to 'sysdeps/sparc/sparc32/dl-machine.h')
| -rw-r--r-- | sysdeps/sparc/sparc32/dl-machine.h | 363 |
1 files changed, 363 insertions, 0 deletions
diff --git a/sysdeps/sparc/sparc32/dl-machine.h b/sysdeps/sparc/sparc32/dl-machine.h new file mode 100644 index 0000000000..f7bcba0c2f --- /dev/null +++ b/sysdeps/sparc/sparc32/dl-machine.h @@ -0,0 +1,363 @@ +/* Machine-dependent ELF dynamic relocation inline functions. SPARC 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. */ + +#define ELF_MACHINE_NAME "sparc" + +#include <assert.h> +#include <string.h> +#include <link.h> +#include <sys/param.h> + + +/* Some SPARC opcodes we need to use for self-modifying code. */ +#define OPCODE_NOP 0x01000000 /* nop */ +#define OPCODE_CALL 0x40000000 /* call ?; add PC-rel word address */ +#define OPCODE_SETHI_G1 0x03000000 /* sethi ?, %g1; add value>>10 */ +#define OPCODE_JMP_G1 0x81c06000 /* jmp %g1+?; add lo 10 bits of value */ +#define OPCODE_SAVE_SP64 0x9de3bfc0 /* save %sp, -64, %sp */ + + +/* Return nonzero iff E_MACHINE is compatible with the running host. */ +static inline int +elf_machine_matches_host (Elf32_Half e_machine) +{ + return e_machine == EM_SPARC; +} + + +/* 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 ("%l7"); + return *got; +} + +/* Return the run-time load address of the shared object. */ +static inline Elf32_Addr +elf_machine_load_address (void) +{ + register Elf32_Addr pc __asm("%o7"), got; + + /* Utilize the fact that a local .got entry will be partially + initialized at startup awaiting its RELATIVE fixup. */ + + __asm("sethi %%hi(.Load_address),%1\n" + ".Load_address:\n\t" + "call 1f\n\t" + "or %1,%%lo(.Load_address),%1\n" + "1:\tld [%%l7+%1],%1" + : "=r"(pc), "=r"(got)); + + return pc - got; +} + + Elf32_Addr addr; + + asm ( + "add %%fp,0x44,%%o2\n\t" /* o2 = point to argc */ + "ld [%%o2 - 4],%%o0\n\t" /* o0 = load argc */ + "sll %%o0, 2, %%o0\n\t" /* o0 = argc * sizeof (int) */ + "add %%o2,%%o0,%%o2\n\t" /* o2 = skip over argv */ + "add %%o2,4,%%o2\n\t" /* skip over null after argv */ + + /* Now %o2 is pointing to env, skip over that as well. */ + "1:\n\t" + "ld [%%o2],%%o0\n\t" + "cmp %%o0,0\n\t" + "bnz 1b\n\t" + "add %%o2,4,%%o2\n\t" + + /* Note that above, we want to advance the NULL after envp so + we always add 4. */ + + /* Now, search for the AT_BASE property. */ + "2:\n\t" + "ld [%%o2],%%o0\n\t" + "cmp %%o0,0\n\t" + "be,a 3f\n\t" + "or %%g0,%%g0,%0\n\t" + "cmp %%o0,7\n\t" /* AT_BASE = 7 */ + "be,a 3f\n\t" + "ld [%%o2+4],%0\n\t" + "b 2b\n\t" + "add %%o2,8,%%o2\n\t" + /* At this point %0 has the load address for the interpreter */ + "3:\n\t" + : "=r" (addr) + : /* no inputs */ + : "o0", "o2"); + return addr; +} + +#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) +{ + Elf32_Addr loadbase; + + if (ELF32_R_TYPE (reloc->r_info) == R_SPARC_RELATIVE) + { +#ifndef RTLD_BOOTSTRAP + if (map != &_dl_rtld_map) /* Already done in rtld itself. */ +#endif + *reloc_addr += map->l_addr + reloc->r_addend; + } + else + { + const Elf32_Sym *const refsym = sym; + Elf32_Addr value; + if (sym->st_shndx != SHN_UNDEF && + ELF32_ST_BIND (sym->st_info) == STB_LOCAL) + value = map->l_addr; + else + { + value = RESOLVE (&sym, version, ELF32_R_TYPE (reloc->r_info)); + if (sym) + value += sym->st_value; + } + value += reloc->r_addend; /* Assume copy relocs have zero addend. */ + + switch (ELF32_R_TYPE (reloc->r_info)) + { + case R_SPARC_COPY: + if (sym->st_size > refsym->st_size + || (_dl_verbose && sym->st_size < refsym->st_size)) + { + extern char **_dl_argv; + 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, (void *) value, MIN (sym->st_size, + refsym->st_size)); + break; + case R_SPARC_GLOB_DAT: + case R_SPARC_32: + *reloc_addr = value; + break; + case R_SPARC_JMP_SLOT: + reloc_addr[1] = OPCODE_SETHI_G1 | (value >> 10); + reloc_addr[2] = OPCODE_JMP_G1 | (value & 0x3ff); + break; + case R_SPARC_8: + *(char *) reloc_addr = value; + break; + case R_SPARC_16: + *(short *) reloc_addr = value; + break; + case R_SPARC_DISP8: + *(char *) reloc_addr = (value - (Elf32_Addr) reloc_addr); + break; + case R_SPARC_DISP16: + *(short *) reloc_addr = (value - (Elf32_Addr) reloc_addr); + break; + case R_SPARC_DISP32: + *reloc_addr = (value - (Elf32_Addr) reloc_addr); + break; + case R_SPARC_LO10: + *reloc_addr = (*reloc_addr & ~0x3ff) | (value & 0x3ff); + break; + case R_SPARC_WDISP30: + *reloc_addr = ((*reloc_addr & 0xc0000000) + | ((value - (unsigned int) reloc_addr) >> 2)); + break; + case R_SPARC_HI22: + *reloc_addr = (*reloc_addr & 0xffc00000) | (value >> 10); + break; + case R_SPARC_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) +{ + switch (ELF32_R_TYPE (reloc->r_info)) + { + case R_SPARC_NONE: + break; + case R_SPARC_JMP_SLOT: + break; + default: + assert (! "unexpected PLT reloc type"); + break; + } +} + +#endif /* RESOLVE */ + +/* Nonzero iff TYPE should not be allowed to resolve to one of + the main executable's symbols, as for a COPY reloc. */ +#define elf_machine_lookup_noexec_p(type) ((type) == R_SPARC_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_SPARC_JMP_SLOT) + +/* A reloc type used for ld.so cmdline arg lookups to reject PLT entries. */ +#define ELF_MACHINE_RELOC_NOPLT R_SPARC_JMP_SLOT + +/* The SPARC never uses Elf32_Rel relocations. */ +#define ELF_MACHINE_NO_REL 1 + +/* The SPARC overlaps DT_RELA and DT_PLTREL. */ +#define ELF_MACHINE_PLTREL_OVERLAP 1 + +/* 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 int +elf_machine_runtime_setup (struct link_map *l, int lazy, int profile) +{ + Elf32_Addr *plt; + extern void _dl_runtime_resolve (Elf32_Word); + + if (l->l_info[DT_JMPREL] && lazy) + { + /* The entries for functions in the PLT have not yet been filled in. + Their initial contents will arrange when called to set the high 22 + bits of %g1 with an offset into the .rela.plt section and jump to + the beginning of the PLT. */ + plt = (Elf32_Addr *) (l->l_addr + l->l_info[DT_PLTGOT]->d_un.d_ptr); + + /* The beginning of the PLT does: + + save %sp, -64, %sp + pltpc: call _dl_runtime_resolve + nop + .word MAP + + This saves the register window containing the arguments, and the + PC value (pltpc) implicitly saved in %o7 by the call points near the + location where we store the link_map pointer for this object. */ + + plt[0] = OPCODE_SAVE_SP64; /* save %sp, -64, %sp */ + /* Construct PC-relative word address. */ + plt[1] = OPCODE_CALL | (((Elf32_Addr) &_dl_runtime_resolve - + (Elf32_Addr) &plt[1]) >> 2); + plt[2] = OPCODE_NOP; /* Fill call delay slot. */ + plt[3] = (Elf32_Addr *) l; + } + + return lazy; +} + +/* 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: + t 1 + #call %g0 + # Pass two args to fixup: the PLT address computed from the PC saved + # in the PLT's call insn, and the reloc offset passed in %g1. + #ld [%o7 + 8], %o1 | Second arg, loaded from PLTPC[2]. + #call fixup + #shrl %g1, 22, %o0 | First arg, set in delay slot of call. + # Jump to the real function. + #jmpl %o0, %g0 + # In the delay slot of that jump, restore the register window + # saved by the first insn of the PLT. + #restore + .size _dl_runtime_resolve, . - _dl_runtime_resolve +"); + +/* 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 ??? + +/* 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\n\ + .globl _start\n\ + .type _start,@function\n\ +_start:\n\ + /* Pass pointer to argument block to _dl_start. */\n\ + add %sp,64,%o0\n\ + call _dl_start\n\ + nop\n\ + \n\ + mov %o0,%l0\n\ + \n\ +2:\n\ + call 1f\n\ + nop\n\ +1:\n\ + sethi %hi(_GLOBAL_OFFSET_TABLE_-(2b-.)),%l2\n\ + sethi %hi(_dl_default_scope),%l3\n\ + or %l2,%lo(_GLOBAL_OFFSET_TABLE_-(2b-.)),%l2\n\ + or %l3,%lo(_dl_default_scope),%l3\n\ + add %o7,%l2,%l1\n\ + # %l1 has the GOT. %l3 has _dl_default_scope GOT offset\n\ + ld [%l1+%l3],%l4\n\ + # %l4 has pointer to _dl_default_scope. Now, load _dl_default_scope [2]\n\ + ld [%l4+8],%l4\n\ + # %l4 has _dl_default_scope [2]\n\ + # call _dl_init_next until it returns 0, pass _dl_default_scope [2]\n\ +3:\n\ + call _dl_init_next\n\ + mov %l4,%o0\n\ + cmp %o0,%g0\n\ + bz,a 4f\n\ + nop\n\ + call %o0\n\ + /* Pass pointer to argument block to this init function */\n\ + add %sp,64,%o0\n\ + b,a 3b\n\ +4:\n\ + # Clear the _dl_starting_up variable and pass _dl_fini in %g1 as per ELF ABI.\n\ + sethi %hi(_dl_starting_up),%l4\n\ + sethi %hi(_dl_fini),%l3\n\ + or %l4,%lo(_dl_starting_up),%l4\n\ + or %l3,%lo(_dl_fini),%l3\n\ + # clear _dl_starting_up\n\ + ld [%l1+%l4],%l5\n\ + st %g0,[%l5]\n\ + # load out fini function for atexit in %g1\n\ + ld [%l3+%l1],%g1\n\ + # jump to the user program entry point.\n\ + jmpl %l0,%g0\n\ + nop\n\ +"); |