CRIS-specific part of ELF dynamic loader.

1 files changed, 392 insertions, 0 deletions

diff --git a/sysdeps/cris/dl-machine.h b/sysdeps/cris/dl-machine.h
new file mode 100644
index 0000000000..beec38184d
--- /dev/null
+++ b/sysdeps/cris/dl-machine.h
@@ -0,0 +1,392 @@
+/* Machine-dependent ELF dynamic relocation inline functions.  CRIS version.
+   Copyright (C) 1996,1997,1998,1999,2000,2001 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.  */
+
+#ifndef dl_machine_h
+#define dl_machine_h
+
+#define ELF_MACHINE_NAME "CRIS"
+
+#include <sys/param.h>
+
+#ifdef __PIC__
+# define CALL_FN(x)							      \
+	"move.d	$pc,$r9\n\t"						      \
+	"add.d	" #x " - .,$r9\n\t"					      \
+	"jsr	$r9"
+#else
+# define CALL_FN(x) "jsr " #x
+#endif
+
+/* Return nonzero iff ELF header is compatible with the running host.  */
+
+static inline int
+elf_machine_matches_host (const Elf32_Ehdr *ehdr)
+{
+  return ehdr->e_machine == EM_CRIS;
+}
+
+/* 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)
+{
+  /* Don't just set this to an asm variable "r0" since that's not logical
+     (like, the variable is uninitialized and the register is fixed) and
+     may make GCC trip over itself doing register allocation.  Yes, I'm
+     paranoid.  Why do you ask?  */
+  Elf32_Addr *got;
+
+  __asm__ ("move.d $r0,%0" : "=rm" (got));
+  return *got;
+}
+
+/* Return the run-time load address of the shared object.  We do it like
+   m68k and i386, by taking an arbitrary local symbol, forcing a GOT entry
+   for it, and peeking into the GOT table, which is set to the link-time
+   file-relative symbol value (regardless of whether the target is REL or
+   RELA).  We subtract this link-time file-relative value from the "local"
+   value we calculate from GOT position and GOT offset.  FIXME: Perhaps
+   there's some other symbol we could use, that we don't *have* to force a
+   GOT entry for.  */
+
+static inline Elf32_Addr
+elf_machine_load_address (void)
+{
+  Elf32_Addr gotaddr_diff;
+  __asm__ ("sub.d [$r0+_dl_start:GOT16],$r0,%0\n\t"
+	   "add.d _dl_start:GOTOFF,%0" : "=r" (gotaddr_diff));
+  return gotaddr_diff;
+}
+
+/* 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 *got;
+  extern void _dl_runtime_resolve (Elf32_Word);
+  extern void _dl_runtime_profile (Elf32_Word);
+
+  if (l->l_info[DT_JMPREL] && lazy)
+    {
+      /* The GOT entries for functions in the PLT have not yet been
+	 filled in.  Their initial contents will arrange when called
+	 to push an offset into the .rela.plt section, push
+	 _GLOBAL_OFFSET_TABLE_[1], and then jump to
+	 _GLOBAL_OFFSET_TABLE_[2].  */
+      got = (Elf32_Addr *) D_PTR (l, l_info[DT_PLTGOT]);
+      got[1] = (Elf32_Addr) l;	/* Identify this shared object.  */
+
+      /* The got[2] entry contains the address of a function which gets
+	 called to get the address of a so far unresolved function and
+	 jump to it.  The profiling extension of the dynamic linker allows
+	 to intercept the calls to collect information.  In this case we
+	 don't store the address in the GOT so that all future calls also
+	 end in this function.  */
+      if (__builtin_expect (profile, 0))
+	{
+	  got[2] = (Elf32_Addr) &_dl_runtime_profile;
+
+	  if (_dl_name_match_p (_dl_profile, l))
+	    {
+	      /* This is the object we are looking for.  Say that we really
+		 want profiling and the timers are started.  */
+	      _dl_profile_map = l;
+	    }
+	}
+      else
+	/* This function will get called to fix up the GOT entry indicated by
+	   the offset on the stack, and then jump to the resolved address.  */
+	got[2] = (Elf32_Addr) &_dl_runtime_resolve;
+    }
+
+  return lazy;
+}
+
+/* This code is used in dl-runtime.c to call the `fixup' function
+   and then redirect to the address it returns.
+
+   We get here with the offset into the relocation table pushed on stack,
+   and the link map in MOF.  */
+
+#define TRAMPOLINE_TEMPLATE(tramp_name, fixup_name) \
+"; Trampoline for " #fixup_name "
+	.globl " #tramp_name "
+	.type " #tramp_name ", @function
+" #tramp_name ":
+	push	$r13
+	push	$r12
+	push	$r11
+	push	$r10
+	push	$r9
+	push	$srp
+	move.d	[$sp+6*4],$r11
+	move	$mof,$r10
+	" CALL_FN (fixup_name) "
+	move.d	$r10,[$sp+6*4]
+	pop	$srp
+	pop	$r9
+	pop	$r10
+	pop	$r11
+	pop	$r12
+	pop	$r13
+	jump	[$sp+]
+	.size " #tramp_name ", . - " #tramp_name "\n"
+#ifndef PROF
+#define ELF_MACHINE_RUNTIME_TRAMPOLINE \
+asm (TRAMPOLINE_TEMPLATE (_dl_runtime_resolve, fixup) \
+     TRAMPOLINE_TEMPLATE (_dl_runtime_profile, profile_fixup));
+#else
+#define ELF_MACHINE_RUNTIME_TRAMPOLINE \
+asm (TRAMPOLINE_TEMPLATE (_dl_runtime_resolve, fixup) \
+     ".globl _dl_runtime_profile\n" \
+     ".set _dl_runtime_profile, _dl_runtime_resolve");
+#endif
+
+
+/* Mask identifying addresses reserved for the user program,
+   where the dynamic linker should not map anything.  */
+#define ELF_MACHINE_USER_ADDRESS_MASK	0xf8000000UL
+
+/* 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
+	.globl	_start
+	.type	_start,@function
+_start:
+	move.d	$sp,$r10
+	" CALL_FN (_dl_start) "
+	/* FALLTHRU */
+
+	.globl _dl_start_user
+	.type _dl_start_user,@function
+_dl_start_user:
+	; Save the user entry point address in R1.
+	move.d	$r10,$r1
+	; Point R0 at the GOT.
+	move.d	$pc,$r0
+	sub.d	.:GOTOFF,$r0
+	; Remember the highest stack address.
+	move.d	[$r0+__libc_stack_end:GOT16],$r13
+	move.d	$sp,[$r13]
+	; See if we were run as a command with the executable file
+	; name as an extra leading argument.
+	move.d	[$r0+_dl_skip_args:GOT16],$r13
+	move.d	[$r13],$r9
+	; Get the original argument count
+	move.d	[$sp],$r11
+	; Subtract _dl_skip_args from it.
+	sub.d	$r9,$r11
+	; Adjust the stack pointer to skip _dl_skip_args words.
+	addi	$r9.d,$sp
+	; Put the new argc in place as expected by the user entry.
+	move.d	$r11,[$sp]
+	; Call _dl_init (struct link_map *main_map, int argc, char **argv, char **env)
+	;  env: skip scaled argc and skip stored argc and NULL at end of argv[].
+	move.d	$sp,$r13
+	addi	$r11.d,$r13
+	addq	8,$r13
+	;  argv: skip stored argc.
+	move.d	$sp,$r12
+	addq	4,$r12
+	;  main_map: at _dl_loaded.
+	move.d	[$r0+_dl_loaded:GOT16],$r9
+	move.d	[$r9],$r10
+	move.d	_dl_init:PLTG,$r9
+	add.d	$r0,$r9
+	jsr	$r9
+	; Pass our finalizer function to the user in R10.
+	move.d [$r0+_dl_fini:GOT16],$r10
+	; Terminate the frame-pointer.
+	moveq	0,$r8
+	; Cause SEGV if user entry returns.
+	move	$r8,$srp
+	; Jump to the user's entry point.
+	jump	$r1
+	.size _dl_start_user, . - _dl_start_user
+	.previous");
+
+/* Nonzero iff TYPE describes a relocation that should
+   skip the executable when looking up the symbol value.  */
+#define elf_machine_lookup_noexec_p(type) ((type) == R_CRIS_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_CRIS_JUMP_SLOT)
+
+/* A reloc type used for ld.so cmdline arg lookups to reject PLT entries.  */
+#define ELF_MACHINE_JMP_SLOT	R_CRIS_JUMP_SLOT
+
+/* CRIS never uses Elf32_Rel relocations.  */
+#define ELF_MACHINE_NO_REL 1
+
+/* We define an initialization functions.  This is called very early in
+   _dl_sysdep_start.  */
+#define DL_PLATFORM_INIT dl_platform_init ()
+
+extern const char *_dl_platform;
+
+static inline void __attribute__ ((unused))
+dl_platform_init (void)
+{
+  if (_dl_platform != NULL && *_dl_platform == '\0')
+    /* Avoid an empty string which would disturb us.  */
+    _dl_platform = NULL;
+}
+
+static inline Elf32_Addr
+elf_machine_fixup_plt (struct link_map *map, lookup_t t,
+		       const Elf32_Rela *reloc,
+		       Elf32_Addr *reloc_addr, Elf32_Addr value)
+{
+  return *reloc_addr = value;
+}
+
+/* Return the final value of a plt relocation.  */
+static inline Elf32_Addr
+elf_machine_plt_value (struct link_map *map, const Elf32_Rela *reloc,
+		       Elf32_Addr value)
+{
+  return value + reloc->r_addend;
+}
+
+#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_rela (struct link_map *map, const Elf32_Rela *reloc,
+		  const Elf32_Sym *sym, const struct r_found_version *version,
+		  Elf32_Addr *const reloc_addr)
+{
+#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);
+#endif
+
+  if (ELF32_R_TYPE (reloc->r_info) == R_CRIS_RELATIVE)
+    {
+#ifndef RTLD_BOOTSTRAP
+      if (map != &_dl_rtld_map) /* Already done in rtld itself. */
+#endif
+	*reloc_addr = map->l_addr + reloc->r_addend;
+    }
+  else
+    {
+#ifndef RTLD_BOOTSTRAP
+      const Elf32_Sym *const refsym = sym;
+#endif
+      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))
+	{
+#ifndef RTLD_BOOTSTRAP
+	case R_CRIS_COPY:
+	  if (sym == NULL)
+	    /* This can happen in trace mode if an object could not be
+	       found.  */
+	    break;
+	  if (sym->st_size > refsym->st_size
+	      || (_dl_verbose && sym->st_size < refsym->st_size))
+	    {
+	      extern char **_dl_argv;
+	      const char *strtab;
+
+	      strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);
+	      _dl_error_printf ("\
+%s: Symbol `%s' has different size in shared object, consider re-linking\n",
+				_dl_argv[0] ?: "<program name unknown>",
+				strtab + refsym->st_name);
+	    }
+	  memcpy (reloc_addr, (void *) value, MIN (sym->st_size,
+						   refsym->st_size));
+	  break;
+
+	case R_CRIS_32:
+#endif
+	case R_CRIS_GLOB_DAT:
+	case R_CRIS_JUMP_SLOT:
+	  *reloc_addr = value;
+	  break;
+#ifndef RTLD_BOOTSTRAP
+	case R_CRIS_8:
+	  *(char *) reloc_addr = value;
+	  break;
+	case R_CRIS_16:
+	  *(short *) reloc_addr = value;
+	  break;
+	case R_CRIS_8_PCREL:
+	  *(char *) reloc_addr
+	    = value + reloc->r_addend - (Elf32_Addr) reloc_addr - 1;
+	  break;
+	case R_CRIS_16_PCREL:
+	  *(short *) reloc_addr
+	    = value + reloc->r_addend - (Elf32_Addr) reloc_addr - 2;
+	  break;
+	case R_CRIS_32_PCREL:
+	  *reloc_addr = value + reloc->r_addend - (Elf32_Addr) reloc_addr - 4;
+	  break;
+#endif
+	case R_CRIS_NONE:
+	  break;
+#if !defined RTLD_BOOTSTRAP || defined _NDEBUG
+	default:
+	  _dl_reloc_bad_type (map, ELFW(R_TYPE) (reloc->r_info), 0);
+	  break;
+#endif
+	}
+    }
+}
+
+static inline void
+elf_machine_lazy_rel (struct link_map *map,
+		      Elf32_Addr l_addr, const Elf32_Rela *reloc)
+{
+  Elf32_Addr *const reloc_addr = (void *) (l_addr + reloc->r_offset);
+  if (__builtin_expect (ELF32_R_TYPE (reloc->r_info), R_CRIS_JUMP_SLOT)
+      == R_CRIS_JUMP_SLOT)
+    *reloc_addr += l_addr;
+  else
+    _dl_reloc_bad_type (map, ELF32_R_TYPE (reloc->r_info), 1);
+}
+
+#endif /* RESOLVE */