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Fri Jul 26 00:36:50 1996 Roland McGrath <roland@delasyd.gnu.ai.mit.edu>
* sysdeps/mips/dl-machine.h: New file, contributed by Kazumoto Kojima <kkojima@info.kanagawa-u.ac.jp>.
This commit is contained in:
Roland McGrath
parent
036cc82fbc
commit
fa8463e5ed
@ -1,3 +1,8 @@
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Fri Jul 26 00:36:50 1996 Roland McGrath <roland@delasyd.gnu.ai.mit.edu>
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* sysdeps/mips/dl-machine.h: New file, contributed by Kazumoto Kojima
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<kkojima@info.kanagawa-u.ac.jp>.
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Fri Jul 26 04:41:28 1996 Ulrich Drepper <drepper@cygnus.com>
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* intl/libintl.h: Define optimizing macros if __OPTIMIZE__ is
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466
sysdeps/mips/dl-machine.h
Normal file
466
sysdeps/mips/dl-machine.h
Normal file
@ -0,0 +1,466 @@
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/* Machine-dependent ELF dynamic relocation inline functions. mips version.
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Copyright (C) 1996 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Kazumoto Kojima <kkojima@info.kanagawa-u.ac.jp>.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Library General Public License as
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published by the Free Software Foundation; either version 2 of the
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License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Library General Public License for more details.
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You should have received a copy of the GNU Library General Public
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License along with the GNU C Library; see the file COPYING.LIB. If
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not, write to the Free Software Foundation, Inc., 675 Mass Ave,
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Cambridge, MA 02139, USA. */
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#define ELF_MACHINE_NAME "MIPS"
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#include <assert.h>
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#include <string.h>
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#include <link.h>
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#include <sys/types.h>
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#include <sys/mman.h>
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#include <unistd.h>
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/* DT_MIPS macro ranslate a processor specific dynamic tag to the index
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in l_info array. */
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#define DT_MIPS(x) (DT_MIPS_##x - DT_LOPROC + DT_NUM)
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#if 1
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/* XXX If FLAGS has the MAP_ALIGN bit, we need 64k alignement. */
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#ifndef MAP_ALIGN
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#define MAP_ALIGN 0x1000
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#endif
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#define ELF_MACHINE_ALIGN_MASK(flags) ((flags & MAP_ALIGN) ? 0xffff : 0)
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#endif
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/* If there is a DT_MIPS_RLD_MAP entry in the dynamic section, fill it in
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with the run-time address of the r_debug structure */
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#define ELF_MACHINE_SET_DEBUG(l,r) \
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do { if ((l)->l_info[DT_MIPS (RLD_MAP)]) \
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*(ElfW(Addr) *)((l)->l_info[DT_MIPS (RLD_MAP)]->d_un.d_ptr) = \
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(ElfW(Addr)) (r); \
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} while (0)
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/* Return nonzero iff E_MACHINE is compatible with the running host. */
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static inline int
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elf_machine_matches_host (ElfW(Half) e_machine)
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{
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switch (e_machine)
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{
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case EM_MIPS:
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case EM_MIPS_RS4_BE:
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return 1;
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default:
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return 0;
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}
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}
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static inline ElfW(Addr) *
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elf_mips_got_from_gpreg (ElfW(Addr) gpreg)
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{
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/* FIXME: the offset of gp from GOT may be system-dependent. */
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return (ElfW(Addr) *) (gpreg - 0x7ff0);
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}
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/* Return the run-time address of the _GLOBAL_OFFSET_TABLE_.
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Must be inlined in a function which uses global data. */
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static inline ElfW(Addr) *
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elf_machine_got (void)
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{
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register ElfW(Addr) gpreg asm ("$28");
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return elf_mips_got_from_gpreg (gpreg);
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}
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/* Return the run-time load address of the shared object. */
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static inline ElfW(Addr)
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elf_machine_load_address (void)
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{
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ElfW(Addr) addr;
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asm (" .set noreorder\n"
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" la %0, here\n"
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" bltzal $0, here\n"
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" nop\n"
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"here: subu %0, $31, %0\n"
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" .set reorder\n"
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: "=r" (addr));
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return addr;
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}
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/* Perform the relocation specified by RELOC and SYM (which is fully resolved).
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MAP is the object containing the reloc. */
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static inline void
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elf_machine_rel (struct link_map *map,
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const ElfW(Rel) *reloc, const ElfW(Sym) *sym,
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ElfW(Addr) (*resolve) (const ElfW(Sym) **ref,
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ElfW(Addr) reloc_addr,
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int noplt))
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{
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ElfW(Addr) *const reloc_addr = (void *) (map->l_addr + reloc->r_offset);
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ElfW(Addr) loadbase, undo;
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switch (ELFW(R_TYPE) (reloc->r_info))
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{
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case R_MIPS_REL32:
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if (ELFW(ST_BIND) (sym->st_info) == STB_LOCAL
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&& (ELFW(ST_TYPE) (sym->st_info) == STT_SECTION
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|| ELFW(ST_TYPE) (sym->st_info) == STT_NOTYPE))
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*reloc_addr += map->l_addr;
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else
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{
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if (resolve && map == &_dl_rtld_map)
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/* Undo the relocation done here during bootstrapping. Now we will
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relocate it anew, possibly using a binding found in the user
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program or a loaded library rather than the dynamic linker's
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built-in definitions used while loading those libraries. */
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undo = map->l_addr + sym->st_value;
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else
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undo = 0;
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loadbase = (resolve ? (*resolve) (&sym, (ElfW(Addr)) reloc_addr, 0) :
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/* RESOLVE is null during bootstrap relocation. */
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map->l_addr);
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*reloc_addr += (sym ? (loadbase + sym->st_value) : 0) - undo;
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}
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break;
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case R_MIPS_NONE: /* Alright, Wilbur. */
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break;
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default:
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assert (! "unexpected dynamic reloc type");
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break;
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}
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}
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static inline void
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elf_machine_lazy_rel (struct link_map *map, const ElfW(Rel) *reloc)
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{
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/* Do nothing. */
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}
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/* The MSB of got[1] of a gnu object is set to identify gnu objects. */
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#define ELF_MIPS_GNU_GOT1_MASK 0x80000000
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/* Relocate GOT. */
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static void
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elf_machine_got_rel (struct link_map *map)
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{
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ElfW(Addr) *got;
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ElfW(Sym) *sym;
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int i, n;
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struct link_map **scope;
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const char *strtab
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= ((void *) map->l_addr + map->l_info[DT_STRTAB]->d_un.d_ptr);
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ElfW(Addr) resolve (const ElfW(Sym) *sym)
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{
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ElfW(Sym) *ref = sym;
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ElfW(Addr) sym_loadaddr;
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sym_loadaddr = _dl_lookup_symbol (strtab + sym->st_name, &ref, scope,
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map->l_name, 0, 1);
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return (ref)? sym_loadaddr + ref->st_value: 0;
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}
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got = (ElfW(Addr) *) ((void *) map->l_addr
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+ map->l_info[DT_PLTGOT]->d_un.d_ptr);
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/* got[0] is reserved. got[1] is also reserved for the dynamic object
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generated by gnu ld. Skip these reserved entries from relocation. */
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i = (got[1] & ELF_MIPS_GNU_GOT1_MASK)? 2: 1;
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n = map->l_info[DT_MIPS (LOCAL_GOTNO)]->d_un.d_val;
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/* Add the run-time display to all local got entries. */
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while (i < n)
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got[i++] += map->l_addr;
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/* Set scope. */
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scope = _dl_object_relocation_scope (map);
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/* Handle global got entries. */
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got += n;
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sym = (ElfW(Sym) *) ((void *) map->l_addr
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+ map->l_info[DT_SYMTAB]->d_un.d_ptr);
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sym += map->l_info[DT_MIPS (GOTSYM)]->d_un.d_val;
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i = (map->l_info[DT_MIPS (SYMTABNO)]->d_un.d_val
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- map->l_info[DT_MIPS (GOTSYM)]->d_un.d_val);
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while (i--)
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{
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if (sym->st_shndx == SHN_UNDEF)
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{
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if (ELFW(ST_TYPE) (sym->st_info) == STT_FUNC)
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{
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if (sym->st_value /* && maybe_stub (sym->st_value) */)
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*got = sym->st_value + map->l_addr;
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else
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*got = resolve (sym);
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}
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else /* if (*got == 0 || *got == QS) */
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*got = resolve (sym);
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}
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else if (sym->st_shndx == SHN_COMMON)
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*got = resolve (sym);
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else if (ELFW(ST_TYPE) (sym->st_info) == STT_FUNC
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&& *got != sym->st_value
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/* && maybe_stub (*got) */)
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*got += map->l_addr;
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else if (ELFW(ST_TYPE) (sym->st_info) == STT_SECTION
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&& ELFW(ST_BIND) (sym->st_info) == STB_GLOBAL)
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{
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if (sym->st_other == 0 && sym->st_shndx == SHN_ABS)
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*got = sym->st_value + map->l_addr; /* only for _gp_disp */
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/* else SGI stuff ignored */
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}
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else
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*got = resolve (sym);
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got++;
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sym++;
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}
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*_dl_global_scope_end = NULL;
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return;
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}
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/* The MIPS never uses Elfxx_Rela relocations. */
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#define ELF_MACHINE_NO_RELA 1
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/* Set up the loaded object described by L so its stub function
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will jump to the on-demand fixup code in dl-runtime.c. */
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static inline void
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elf_machine_runtime_setup (struct link_map *l, int lazy)
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{
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ElfW(Addr) *got;
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extern void _dl_runtime_resolve (ElfW(Word));
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if (lazy)
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{
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/* The GOT entries for functions have not yet been filled in.
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Their initial contents will arrange when called to put an
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offset into the .dynsym section in t8, the return address
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in t7 and then jump to _GLOBAL_OFFSET_TABLE[0]. */
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got = (ElfW(Addr) *) ((void *) l->l_addr
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+ l->l_info[DT_PLTGOT]->d_un.d_ptr);
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/* This function will get called to fix up the GOT entry indicated by
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the register t8, and then jump to the resolved address. */
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got[0] = (ElfW(Addr)) &_dl_runtime_resolve;
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/* Store l to _GLOBAL_OFFSET_TABLE[1] for gnu object. The MSB
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of got[1] of a gnu object is set to identify gnu objects.
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Where we can store l for non gnu objects? XXX */
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if ((got[1] & ELF_MIPS_GNU_GOT1_MASK) != 0)
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got[1] = (ElfW(Addr)) ((unsigned) l | ELF_MIPS_GNU_GOT1_MASK);
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else
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; /* Do nothing. */
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}
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/* Relocate global offset table. */
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elf_machine_got_rel (l);
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}
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/* Get link_map for this object. */
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static inline struct link_map *
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elf_machine_runtime_link_map (ElfW(Addr) gpreg)
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{
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ElfW(Addr) *got = elf_mips_got_from_gpreg (gpreg);
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ElfW(Word) g1;
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g1 = ((ElfW(Word) *) got)[1];
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/* got[1] is reserved to keep its link map address for the shared
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object generated by gnu linker. If not so, we must search GOT
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in object list slowly. XXX */
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if ((g1 & ELF_MIPS_GNU_GOT1_MASK) != 0)
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return (struct link_map *) (g1 & ~ELF_MIPS_GNU_GOT1_MASK);
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else
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{
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struct link_map *l = _dl_loaded;
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while (l)
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{
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if (got == (ElfW(Addr) *) ((void *) l->l_addr
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+ l->l_info[DT_PLTGOT]->d_un.d_ptr))
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return l;
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l = l->l_next;
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}
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}
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_dl_signal_error (0, NULL, "cannot find runtime link map");
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}
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/* Mips has no PLT but define elf_machine_relplt to be elf_machine_rel. */
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#define elf_machine_relplt elf_machine_rel
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/* Define mips specific runtime resolver. The function __dl_runtime_resolve
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is called from assembler function _dl_runtime_resolve which converts
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special argument registers t7 ($15) and t8 ($24):
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t7 address to return to the caller of the function
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t8 index for this function symbol in .dynsym
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to usual c arguments. */
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#define ELF_MACHINE_RUNTIME_TRAMPOLINE \
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static ElfW(Addr) \
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__dl_runtime_resolve (ElfW(Word) sym_index,\
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ElfW(Word) return_address,\
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ElfW(Addr) old_gpreg)\
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{\
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struct link_map *l = elf_machine_runtime_link_map (old_gpreg);\
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const ElfW(Sym) *const symtab\
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= (const ElfW(Sym) *) (l->l_addr + l->l_info[DT_SYMTAB]->d_un.d_ptr);\
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const char *strtab\
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= (void *) (l->l_addr + l->l_info[DT_STRTAB]->d_un.d_ptr);\
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const ElfW(Addr) *got\
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= (const ElfW(Addr) *) (l->l_addr + l->l_info[DT_PLTGOT]->d_un.d_ptr);\
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const ElfW(Word) local_gotno\
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= (const ElfW(Word)) l->l_info[DT_MIPS (LOCAL_GOTNO)]->d_un.d_val;\
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const ElfW(Word) gotsym\
|
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= (const ElfW(Word)) l->l_info[DT_MIPS (GOTSYM)]->d_un.d_val;\
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const ElfW(Sym) *definer;\
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ElfW(Addr) loadbase;\
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ElfW(Addr) funcaddr;\
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struct link_map **scope;\
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\
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/* Look up the symbol's run-time value. */\
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scope = _dl_object_relocation_scope (l);\
|
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definer = &symtab[sym_index];\
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\
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loadbase = _dl_lookup_symbol (strtab + definer->st_name, &definer,\
|
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scope, l->l_name, 0, 1);\
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\
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*_dl_global_scope_end = NULL;\
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\
|
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/* Apply the relocation with that value. */\
|
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funcaddr = loadbase + definer->st_value;\
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*(got + local_gotno + sym_index - gotsym) = funcaddr;\
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\
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return funcaddr;\
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||||
}\
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||||
\
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||||
asm ("\n\
|
||||
.text\n\
|
||||
.align 2\n\
|
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.globl _dl_runtime_resolve\n\
|
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.type _dl_runtime_resolve,@function\n\
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.ent _dl_runtime_resolve\n\
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_dl_runtime_resolve:\n\
|
||||
.set noreorder\n\
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||||
# Save old GP to $3.\n\
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||||
move $3,$28\n\
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# Modify t9 ($25) so as to point .cpload instruction.\n\
|
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addu $25,8\n\
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# Compute GP.\n\
|
||||
.cpload $25\n\
|
||||
.set reorder\n\
|
||||
# Save arguments and sp value in stack.\n\
|
||||
subu $29, 40\n\
|
||||
.cprestore 32\n\
|
||||
sw $15, 36($29)\n\
|
||||
sw $4, 12($29)\n\
|
||||
sw $5, 16($29)\n\
|
||||
sw $6, 20($29)\n\
|
||||
sw $7, 24($29)\n\
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||||
sw $16, 28($29)\n\
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||||
move $16, $29\n\
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move $4, $24\n\
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||||
move $5, $15\n\
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||||
move $6, $3\n\
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jal __dl_runtime_resolve\n\
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||||
move $29, $16\n\
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lw $31, 36($29)\n\
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lw $4, 12($29)\n\
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||||
lw $5, 16($29)\n\
|
||||
lw $6, 20($29)\n\
|
||||
lw $7, 24($29)\n\
|
||||
lw $16, 28($29)\n\
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||||
addu $29, 40\n\
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||||
move $25, $2\n\
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||||
jr $25\n\
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||||
.end _dl_runtime_resolve\n\
|
||||
");
|
||||
|
||||
/* Mask identifying addresses reserved for the user program,
|
||||
where the dynamic linker should not map anything. */
|
||||
#define ELF_MACHINE_USER_ADDRESS_MASK 0x00000000UL
|
||||
|
||||
|
||||
|
||||
/* 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\
|
||||
.globl _dl_start_user\n\
|
||||
.ent _start\n\
|
||||
_start:\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\
|
||||
la $4, _DYNAMIC\n\
|
||||
sw $4, -0x7ff0($28)\n\
|
||||
move $4, $29\n\
|
||||
jal _dl_start\n\
|
||||
# Get the value of label '_dl_start_user' in t9 ($25).\n\
|
||||
la $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\
|
||||
# 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\
|
||||
# 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\
|
||||
# Save back the modified argument count.\n\
|
||||
sw $4, 0($29)\n\
|
||||
# Get _dl_default_scope[2] as argument in _dl_init_next call below.\n\
|
||||
1: la $2, _dl_default_scope\n\
|
||||
lw $4, 8($2)\n\
|
||||
# Call _dl_init_next to return the address of an initializer\n\
|
||||
# function to run.\n\
|
||||
jal _dl_init_next\n\
|
||||
move $28, $16\n\
|
||||
# Check for zero return, when out of initializers.\n\
|
||||
beq $2, $0, 2f\n\
|
||||
# Call the shared object initializer function.\n\
|
||||
move $25, $2\n\
|
||||
lw $4, 0($29)\n\
|
||||
lw $5, 4($29)\n\
|
||||
lw $6, 8($29)\n\
|
||||
lw $7, 12($29)\n\
|
||||
jalr $25\n\
|
||||
move $28, $16\n\
|
||||
# Loop to call _dl_init_next for the next initializer.\n\
|
||||
b 1b\n\
|
||||
# Pass our finalizer function to the user in ra.\n\
|
||||
2: la $31, _dl_fini\n\
|
||||
# Jump to the user entry point.\n\
|
||||
move $25, $17\n\
|
||||
lw $4, 0($29)\n\
|
||||
lw $5, 4($29)\n\
|
||||
lw $6, 8($29)\n\
|
||||
lw $7, 12($29)\n\
|
||||
jr $25\n\
|
||||
.end _start\n\
|
||||
");
|
||||
|
||||
Loading…
Reference in New Issue
Block a user