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-rw-r--r--sysdeps/mips/dl-machine.h466
1 files changed, 466 insertions, 0 deletions
diff --git a/sysdeps/mips/dl-machine.h b/sysdeps/mips/dl-machine.h
new file mode 100644
index 0000000..822d9ab
--- /dev/null
+++ b/sysdeps/mips/dl-machine.h
@@ -0,0 +1,466 @@
+/* Machine-dependent ELF dynamic relocation inline functions. mips version.
+Copyright (C) 1996 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 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., 675 Mass Ave,
+Cambridge, MA 02139, USA. */
+
+#define ELF_MACHINE_NAME "MIPS"
+
+#include <assert.h>
+#include <string.h>
+#include <link.h>
+#include <sys/types.h>
+#include <sys/mman.h>
+#include <unistd.h>
+
+/* DT_MIPS macro ranslate a processor specific dynamic tag to the index
+ in l_info array. */
+#define DT_MIPS(x) (DT_MIPS_##x - DT_LOPROC + DT_NUM)
+
+#if 1
+/* XXX If FLAGS has the MAP_ALIGN bit, we need 64k alignement. */
+#ifndef MAP_ALIGN
+#define MAP_ALIGN 0x1000
+#endif
+#define ELF_MACHINE_ALIGN_MASK(flags) ((flags & MAP_ALIGN) ? 0xffff : 0)
+#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_SET_DEBUG(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 E_MACHINE is compatible with the running host. */
+static inline int
+elf_machine_matches_host (ElfW(Half) e_machine)
+{
+ switch (e_machine)
+ {
+ case EM_MIPS:
+ case EM_MIPS_RS4_BE:
+ 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 run-time address of the _GLOBAL_OFFSET_TABLE_.
+ Must be inlined in a function which uses global data. */
+static inline ElfW(Addr) *
+elf_machine_got (void)
+{
+ register ElfW(Addr) gpreg asm ("$28");
+ return elf_mips_got_from_gpreg (gpreg);
+}
+
+
+/* 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"
+ " la %0, here\n"
+ " bltzal $0, here\n"
+ " nop\n"
+ "here: subu %0, $31, %0\n"
+ " .set reorder\n"
+ : "=r" (addr));
+ return addr;
+}
+
+/* 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,
+ ElfW(Addr) (*resolve) (const ElfW(Sym) **ref,
+ ElfW(Addr) reloc_addr,
+ int noplt))
+{
+ ElfW(Addr) *const reloc_addr = (void *) (map->l_addr + reloc->r_offset);
+ ElfW(Addr) loadbase, undo;
+
+ switch (ELFW(R_TYPE) (reloc->r_info))
+ {
+ case R_MIPS_REL32:
+ 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;
+ else
+ {
+ if (resolve && map == &_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;
+ else
+ undo = 0;
+ loadbase = (resolve ? (*resolve) (&sym, (ElfW(Addr)) reloc_addr, 0) :
+ /* RESOLVE is null during bootstrap relocation. */
+ map->l_addr);
+ *reloc_addr += (sym ? (loadbase + sym->st_value) : 0) - undo;
+ }
+ break;
+ case R_MIPS_NONE: /* Alright, Wilbur. */
+ break;
+ default:
+ assert (! "unexpected dynamic reloc type");
+ break;
+ }
+}
+
+static inline void
+elf_machine_lazy_rel (struct link_map *map, const ElfW(Rel) *reloc)
+{
+ /* Do nothing. */
+}
+
+/* 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 void
+elf_machine_got_rel (struct link_map *map)
+{
+ ElfW(Addr) *got;
+ ElfW(Sym) *sym;
+ int i, n;
+ struct link_map **scope;
+ const char *strtab
+ = ((void *) map->l_addr + map->l_info[DT_STRTAB]->d_un.d_ptr);
+
+ ElfW(Addr) resolve (const ElfW(Sym) *sym)
+ {
+ ElfW(Sym) *ref = sym;
+ ElfW(Addr) sym_loadaddr;
+ sym_loadaddr = _dl_lookup_symbol (strtab + sym->st_name, &ref, scope,
+ map->l_name, 0, 1);
+ return (ref)? sym_loadaddr + ref->st_value: 0;
+ }
+
+ got = (ElfW(Addr) *) ((void *) map->l_addr
+ + map->l_info[DT_PLTGOT]->d_un.d_ptr);
+
+ /* 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;
+
+ /* Set scope. */
+ scope = _dl_object_relocation_scope (map);
+
+ /* Handle global got entries. */
+ got += n;
+ sym = (ElfW(Sym) *) ((void *) map->l_addr
+ + map->l_info[DT_SYMTAB]->d_un.d_ptr);
+ 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 /* && maybe_stub (sym->st_value) */)
+ *got = sym->st_value + map->l_addr;
+ else
+ *got = resolve (sym);
+ }
+ else /* if (*got == 0 || *got == QS) */
+ *got = resolve (sym);
+ }
+ else if (sym->st_shndx == SHN_COMMON)
+ *got = resolve (sym);
+ else if (ELFW(ST_TYPE) (sym->st_info) == STT_FUNC
+ && *got != sym->st_value
+ /* && maybe_stub (*got) */)
+ *got += map->l_addr;
+ else if (ELFW(ST_TYPE) (sym->st_info) == STT_SECTION
+ && ELFW(ST_BIND) (sym->st_info) == STB_GLOBAL)
+ {
+ if (sym->st_other == 0 && sym->st_shndx == SHN_ABS)
+ *got = sym->st_value + map->l_addr; /* only for _gp_disp */
+ /* else SGI stuff ignored */
+ }
+ else
+ *got = resolve (sym);
+
+ got++;
+ sym++;
+ }
+
+ *_dl_global_scope_end = NULL;
+
+ return;
+}
+
+/* The MIPS never uses Elfxx_Rela relocations. */
+#define ELF_MACHINE_NO_RELA 1
+
+/* 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 void
+elf_machine_runtime_setup (struct link_map *l, int lazy)
+{
+ ElfW(Addr) *got;
+ extern void _dl_runtime_resolve (ElfW(Word));
+
+ 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) *) ((void *) l->l_addr
+ + l->l_info[DT_PLTGOT]->d_un.d_ptr);
+
+ /* 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
+ ; /* Do nothing. */
+ }
+
+ /* Relocate global offset table. */
+ elf_machine_got_rel (l);
+}
+
+/* Get link_map for this object. */
+static inline struct link_map *
+elf_machine_runtime_link_map (ElfW(Addr) gpreg)
+{
+ ElfW(Addr) *got = elf_mips_got_from_gpreg (gpreg);
+ ElfW(Word) g1;
+
+ g1 = ((ElfW(Word) *) got)[1];
+
+ /* got[1] is reserved to keep its link map address for the shared
+ object generated by gnu linker. If not so, we must search GOT
+ in object list slowly. XXX */
+ if ((g1 & ELF_MIPS_GNU_GOT1_MASK) != 0)
+ return (struct link_map *) (g1 & ~ELF_MIPS_GNU_GOT1_MASK);
+ else
+ {
+ struct link_map *l = _dl_loaded;
+ while (l)
+ {
+ if (got == (ElfW(Addr) *) ((void *) l->l_addr
+ + l->l_info[DT_PLTGOT]->d_un.d_ptr))
+ return l;
+ l = l->l_next;
+ }
+ }
+ _dl_signal_error (0, NULL, "cannot find runtime link map");
+}
+
+/* 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 \
+static ElfW(Addr) \
+__dl_runtime_resolve (ElfW(Word) sym_index,\
+ ElfW(Word) return_address,\
+ ElfW(Addr) old_gpreg)\
+{\
+ struct link_map *l = elf_machine_runtime_link_map (old_gpreg);\
+ const ElfW(Sym) *const symtab\
+ = (const ElfW(Sym) *) (l->l_addr + l->l_info[DT_SYMTAB]->d_un.d_ptr);\
+ const char *strtab\
+ = (void *) (l->l_addr + l->l_info[DT_STRTAB]->d_un.d_ptr);\
+ const ElfW(Addr) *got\
+ = (const ElfW(Addr) *) (l->l_addr + l->l_info[DT_PLTGOT]->d_un.d_ptr);\
+ 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;\
+ struct link_map **scope;\
+\
+ /* Look up the symbol's run-time value. */\
+ scope = _dl_object_relocation_scope (l);\
+ definer = &symtab[sym_index];\
+\
+ loadbase = _dl_lookup_symbol (strtab + definer->st_name, &definer,\
+ scope, l->l_name, 0, 1);\
+\
+ *_dl_global_scope_end = NULL;\
+\
+ /* 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 2\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\
+ addu $25,8\n\
+ # 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\
+ sw $16, 28($29)\n\
+ move $16, $29\n\
+ move $4, $24\n\
+ move $5, $15\n\
+ move $6, $3\n\
+ jal __dl_runtime_resolve\n\
+ move $29, $16\n\
+ lw $31, 36($29)\n\
+ lw $4, 12($29)\n\
+ lw $5, 16($29)\n\
+ lw $6, 20($29)\n\
+ lw $7, 24($29)\n\
+ lw $16, 28($29)\n\
+ addu $29, 40\n\
+ move $25, $2\n\
+ jr $25\n\
+ .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\
+");
+
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