summaryrefslogtreecommitdiff
path: root/sysdeps/mips/mips64/dl-machine.h
diff options
context:
space:
mode:
Diffstat (limited to 'sysdeps/mips/mips64/dl-machine.h')
-rw-r--r--sysdeps/mips/mips64/dl-machine.h594
1 files changed, 594 insertions, 0 deletions
diff --git a/sysdeps/mips/mips64/dl-machine.h b/sysdeps/mips/mips64/dl-machine.h
new file mode 100644
index 0000000000..3277b109d9
--- /dev/null
+++ b/sysdeps/mips/mips64/dl-machine.h
@@ -0,0 +1,594 @@
+/* Machine-dependent ELF dynamic relocation inline functions. MIPS version.
+ Copyright (C) 1996, 1997 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., 59 Temple Place - Suite 330,
+ Boston, MA 02111-1307, USA. */
+
+#ifndef dl_machine_h
+#define dl_machine_h
+
+#define ELF_MACHINE_NAME "MIPS"
+
+#include <assert.h>
+#include <entry.h>
+
+#ifndef ENTRY_POINT
+#error ENTRY_POINT needs to be defined for MIPS.
+#endif
+
+#ifndef _RTLD_PROLOGUE
+#ifdef __STDC__
+#define _RTLD_PROLOGUE(entry) "\n\t.globl " #entry \
+ "\n\t.ent " #entry \
+ "\n\t" #entry ":\n\t"
+#else
+#define _RTLD_PROLOGUE(entry) "\n\t.globl entry\n\t.ent entry\n\t entry:\n\t"
+#endif
+#endif
+
+#ifndef _RTLD_EPILOGUE
+#ifdef __STDC__
+#define _RTLD_EPILOGUE(entry) "\t.end " #entry "\n"
+#else
+#define _RTLD_EPILOGUE(entry) "\t.end entry\n"
+#endif
+#endif
+
+/* I have no idea what I am doing. */
+#define ELF_MACHINE_RELOC_NOPLT -1
+#define elf_machine_lookup_noplt_p(type) (1)
+#define elf_machine_lookup_noexec_p(type) (0)
+
+/* 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 0
+/* We may need 64k alignment. */
+#define ELF_MACHINE_ALIGN_MASK 0xffff
+#endif
+
+/*
+ * MIPS libraries are usually linked to a non-zero base address. We
+ * subtrace the base address from the address where we map the object
+ * to. This results in more efficient address space usage.
+ */
+#if 0
+#define MAP_BASE_ADDR(l) ((l)->l_info[DT_MIPS(BASE_ADDRESS)] ? \
+ (l)->l_info[DT_MIPS(BASE_ADDRESS)]->d_un.d_ptr : 0)
+#else
+#define MAP_BASE_ADDR(l) 0x5ffe0000
+#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_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 E_MACHINE is compatible with the running host. */
+static inline int __attribute__ ((unused))
+elf_machine_matches_host (ElfW(Half) e_machine)
+{
+ switch (e_machine)
+ {
+ case EM_MIPS:
+ case EM_MIPS_RS4_BE:
+ return 1;
+ default:
+ return 0;
+ }
+}
+
+/* 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 ElfW(Addr)
++elf_machine_dynamic (void)
++{
++ register ElfW(Addr) gp asm ("$28");
++ return * (ElfW(Addr) *) (gp - 0x7ff0);
++}
++
+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)
+{
+ ElfW(Addr) gp;
+
+ __asm__ __volatile__("move %0, $28\n\t" : "=r" (gp));
+ return elf_mips_got_from_gpreg (gp);
+}
+
+
+/* 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"
+ " dla %0, here\n"
+ " bltzal $0, here\n"
+ " nop\n"
+ "here: dsubu %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. */
+#define ELF_MIPS_GNU_GOT1_MASK 0x80000000
+
+/* Relocate GOT. */
+static inline void
+elf_machine_got_rel (struct link_map *map, int lazy)
+{
+ 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);
+
+#define RESOLVE_GOTSYM(sym) \
+ ({ \
+ const ElfW(Sym) *ref = sym; \
+ ElfW(Addr) sym_loadaddr; \
+ sym_loadaddr = _dl_lookup_symbol (strtab + sym->st_name, &ref, scope, \
+ map->l_name, ELF_MACHINE_RELOC_NOPLT);\
+ (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 && lazy)
+ *got = sym->st_value + map->l_addr;
+ else
+ *got = RESOLVE_GOTSYM (sym);
+ }
+ else /* if (*got == 0 || *got == QS) */
+ *got = RESOLVE_GOTSYM (sym);
+ }
+ else if (sym->st_shndx == SHN_COMMON)
+ *got = RESOLVE_GOTSYM (sym);
+ 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);
+
+ got++;
+ sym++;
+ }
+
+#undef RESOLVE_GOTSYM
+ *_dl_global_scope_end = NULL;
+
+ return;
+}
+
+/* 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 int
+elf_machine_runtime_setup (struct link_map *l, int lazy)
+{
+ ElfW(Addr) *got;
+ extern void _dl_runtime_resolve (ElfW(Word));
+ extern int _dl_mips_gnu_objects;
+
+#ifdef RTLD_BOOTSTRAP
+ {
+ return lazy;
+ }
+#endif
+ 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
+ _dl_mips_gnu_objects = 0;
+ }
+
+ /* Relocate global offset table. */
+ elf_machine_got_rel (l, lazy);
+
+ return lazy;
+}
+
+/* Get link_map for this object. */
+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 gnu linker. If all are such object, we can
+ find link map from current GPREG simply. If not so, get link map
+ for callers 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)
+ return (struct link_map *) (g1 & ~ELF_MIPS_GNU_GOT1_MASK);
+ }
+
+ {
+ struct link_map *l = _dl_loaded;
+ struct link_map *ret = 0;
+ ElfW(Addr) candidate = 0;
+
+ while (l)
+ {
+ ElfW(Addr) base = 0;
+ const ElfW(Phdr) *p = l->l_phdr;
+ ElfW(Half) this, nent = l->l_phnum;
+
+ /* Get the base. */
+ for (this = 0; this < nent; this++)
+ if (p[this].p_type == PT_LOAD)
+ {
+ base = p[this].p_vaddr + l->l_addr;
+ break;
+ }
+ if (! base)
+ {
+ l = l->l_next;
+ continue;
+ }
+
+ /* Find closest link base addr. */
+ if ((base < stub_pc) && (candidate < base))
+ {
+ candidate = base;
+ ret = l;
+ }
+ l = l->l_next;
+ }
+ if (candidate && ret && (candidate < stub_pc))
+ return ret;
+ else if (!candidate)
+ return _dl_loaded;
+ }
+
+ _dl_signal_error (0, NULL, "cannot find runtime link map");
+ return NULL;
+}
+
+/* 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 \
+/* 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__ ((unused)); \
+ \
+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) *) (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, ELF_MACHINE_RELOC_NOPLT); \
+ \
+ *_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 3\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 \
+ daddu $25,2*8\n \
+ # Compute GP.\n \
+ .cpload $25\n \
+ .set reorder\n \
+ # Save slot call pc.\n \
+ move $2, $31\n \
+ # Save arguments and sp value in stack.\n \
+ dsubu $29, 10*8\n \
+ .cprestore 8*8\n \
+ sd $15, 9*8($29)\n \
+ sd $4, 3*8($29)\n \
+ sd $5, 4*8($29)\n \
+ sd $6, 5*8($29)\n \
+ sd $7, 6*8($29)\n \
+ sd $16, 7*8($29)\n \
+ move $16, $29\n \
+ move $4, $24\n \
+ move $5, $15\n \
+ move $6, $3\n \
+ move $7, $2\n \
+ jal __dl_runtime_resolve\n \
+ move $29, $16\n \
+ ld $31, 9*8($29)\n \
+ ld $4, 3*8($29)\n \
+ ld $5, 4*8($29)\n \
+ ld $6, 5*8($29)\n \
+ ld $7, 6*8($29)\n \
+ ld $16, 7*8($29)\n \
+ daddu $29, 10*8\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 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\
+ .align 3\n"\
+_RTLD_PROLOGUE (ENTRY_POINT)\
+" .globl _dl_start_user\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\
+ dla $4, _DYNAMIC\n\
+ sd $4, -0x7ff0($28)\n\
+ move $4, $29\n\
+ jal _dl_start\n\
+ # Get the value of label '_dl_start_user' in t9 ($25).\n\
+ dla $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\
+ ld $2, _dl_skip_args\n\
+ beq $2, $0, 1f\n\
+ # Load the original argument count.\n\
+ ld $4, 0($29)\n\
+ # Subtract _dl_skip_args from it.\n\
+ dsubu $4, $2\n\
+ # Adjust the stack pointer to skip _dl_skip_args words.\n\
+ dsll $2,2\n\
+ daddu $29, $2\n\
+ # Save back the modified argument count.\n\
+ sd $4, 0($29)\n\
+ # Get _dl_default_scope[2] as argument in _dl_init_next call below.\n\
+1: dla $2, _dl_default_scope\n\
+ ld $4, 2*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\
+ ld $4, 0($29)\n\
+ ld $5, 1*8($29)\n\
+ ld $6, 2*8($29)\n\
+ ld $7, 3*8($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: dla $31, _dl_fini\n\
+ # Jump to the user entry point.\n\
+ move $25, $17\n\
+ ld $4, 0($29)\n\
+ ld $5, 1*8($29)\n\
+ ld $6, 2*8$29)\n\
+ ld $7, 3*8($29)\n\
+ jr $25\n"\
+_RTLD_EPILOGUE(ENTRY_POINT) \
+);
+
+
+/* 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
+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 = (void *) (map->l_addr + reloc->r_offset);
+ ElfW(Addr) loadbase;
+ ElfW(Addr) undo __attribute__ ((unused));
+
+ switch (ELFW(R_TYPE) (reloc->r_info))
+ {
+ case R_MIPS_REL32:
+ {
+ ElfW(Addr) undo = 0;
+
+ 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;
+ break;
+ }
+#ifndef RTLD_BOOTSTRAP
+ /* 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 (_dl_rtld_map);
+ if (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;
+#endif
+ loadbase = RESOLVE (&sym, version, 0);
+ *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. */
+}
+
+#endif /* RESOLVE */
View Lorry Controller Status