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-rw-r--r--sysdeps/arm/dl-machine.h478
1 files changed, 478 insertions, 0 deletions
diff --git a/sysdeps/arm/dl-machine.h b/sysdeps/arm/dl-machine.h
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+/* Machine-dependent ELF dynamic relocation inline functions.  ARM version.
+   Copyright (C) 1995, 1996, 1997, 1998 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 "ARM"
+
+#include <sys/param.h>
+
+#include <assert.h>
+
+/* Return nonzero iff E_MACHINE is compatible with the running host.  */
+static inline int __attribute__ ((unused))
+elf_machine_matches_host (Elf32_Half e_machine)
+{
+  switch (e_machine)
+    {
+    case EM_ARM:
+      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 Elf32_Addr __attribute__ ((unused))
+elf_machine_dynamic (void)
+{
+  register Elf32_Addr *got asm ("r10");
+  return *got;
+}
+
+
+/* Return the run-time load address of the shared object.  */
+// patb
+static inline Elf32_Addr __attribute__ ((unused))
+elf_machine_load_address (void)
+{
+  Elf32_Addr addr;
+  asm (" ldr ip,.L1
+  	ldr r3,.L3
+	add r3, r3, sl
+  	ldr ip,[sl, ip]
+  	sub ip, r3, ip
+  	b .L2
+  	.L1: .word _dl_start(GOT)
+	.L3: .word _dl_start(GOTOFF)
+  	.L2: mov %0, ip"
+       : "=r" (addr) : : "ip", "r3");
+  return addr;
+}
+
+
+/* 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 __attribute__ ((unused))
+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)
+    {
+      /* patb: this is different than i386 */
+      /* The GOT entries for functions in the PLT have not yet been filled
+	 in.  Their initial contents will arrange when called to push an
+	 index into the .got section, load ip with &_GLOBAL_OFFSET_TABLE_[3],
+	 and then jump to _GLOBAL_OFFSET_TABLE[2].  */
+      got = (Elf32_Addr *) (l->l_addr + l->l_info[DT_PLTGOT]->d_un.d_ptr);
+      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 (profile)
+	{
+	  got[2] = (Elf32_Addr) &_dl_runtime_profile;
+	  /* 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.  */
+   // macro for handling PIC situation....
+#ifdef PIC
+#define CALL_ROUTINE(x) " ldr sl,0f
+	add 	sl, pc, sl
+1:	ldr	r2, 2f
+	mov	lr, pc
+	add	pc, sl, r2
+	b	3f
+0:	.word	_GLOBAL_OFFSET_TABLE_ - 1b - 4
+2:	.word " #x "(GOTOFF)
+3:	"
+#else
+#define CALL_ROUTINE(x) " bl " #x
+#endif
+
+#ifndef PROF
+# define ELF_MACHINE_RUNTIME_TRAMPOLINE asm ("\
+	.text
+	.globl _dl_runtime_resolve
+	.type _dl_runtime_resolve, #function
+	.align 2
+_dl_runtime_resolve:
+	@ we get called with
+	@ 	stack[0] contains the return address from this call
+	@	ip contains &GOT[n+3] (pointer to function)
+	@	lr points to &GOT[2]
+
+	@ save almost everything; lr is already on the stack
+	stmdb	sp!,{r0-r3,sl,fp}
+
+	@ prepare to call fixup()
+
+	@ change &GOT[n+3] into 8*n        NOTE: reloc are 8 bytes each
+	sub	r1, ip, lr
+	sub	r1, r1, #4
+	add	r1, r1, r1
+
+	@ get pointer to linker struct
+	ldr	r0, [lr, #-4]
+
+	" CALL_ROUTINE(fixup) "
+
+	@ save the return
+	mov	ip, r0
+
+	@ restore the stack
+	ldmia	sp!,{r0-r3,sl,fp,lr}
+
+	@ jump to the newly found address
+	mov	pc, ip
+
+	.size _dl_runtime_resolve, .-_dl_runtime_resolve
+
+	.globl _dl_runtime_profile
+	.type _dl_runtime_profile, #function
+	.align 2
+_dl_runtime_profile:
+	@ we get caled with
+	@ 	stack[0] contains the return address from this call
+	@	ip contains &GOT[n+3] (pointer to function)
+	@	lr points to &GOT[2]
+
+	@ save almost everything; return add is already on the stack
+	stmdb	sp!,{r0-r3,fp}
+
+	@ prepare to call fixup()
+
+	@ change &GOT[n+3] into 8*n        NOTE: reloc are 8 bytes each
+	sub	r1, ip, lr
+	sub	r1, r1, #4
+	add	r1, r1, r1
+
+	@ get pointer to linker struct
+	ldr	r0, [lr, #-4]
+
+	" CALL_ROUTINE(profile_fixup) "
+
+	@ save the return
+	mov	ip, r0
+
+	@ restore the stack
+	ldmia	sp!,{r0-r3,fp,lr}
+
+	@ jump to the newly found address
+	mov	pc, ip
+
+	.size _dl_runtime_profile, .-_dl_runtime_profile
+	.previous
+");
+#else // PROF
+# define ELF_MACHINE_RUNTIME_TRAMPOLINE asm ("\
+	.text
+	.globl _dl_runtime_resolve
+	.globl _dl_runtime_profile
+	.type _dl_runtime_resolve, #function
+	.type _dl_runtime_profile, #function
+	.align 2
+_dl_runtime_resolve:
+_dl_runtime_profile:
+	stmdb	sp!,{r0-r3,fp}
+	ldr	r1,[sp,#0x34]
+	sub	r1, ip, lr
+	sub	r1, r1, #4
+	add	r1, r1, r1
+	ldr	r0, [lr, #-4]
+	" CALL_ROUTINE(fixup) "
+	mov	ip, r0
+	ldmia	sp!,{r0-r3,fp,lr}
+	mov	pc, ip
+
+	.size _dl_runtime_profile, .-_dl_runtime_profile
+	.previous
+");
+#endif //PROF
+
+/* 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
+.globl _dl_start_user
+_start:
+	@ at start time, all the args are on the stack
+	mov	r0, sp
+	bl	_dl_start
+	@ returns user entry point in r0
+_dl_start_user:
+	mov	r6, r0
+	@ we are PIC code, so get global offset table
+	ldr	sl, .L_GET_GOT
+	add	sl, pc, sl
+.L_GOT_GOT:
+	@ See if we were run as a command with the executable file
+	@ name as an extra leading argument.
+	ldr	r1, .L_SKIP_ARGS
+	ldr	r1, [sl, r1]
+	@ get the original arg count
+	ldr	r0, [sp]
+	@ subtract _dl_skip_args from it
+	sub	r0, r0, r1
+	@ adjust the stack pointer to skip them
+	add	sp, sp, r1, lsl #2
+	@ store the new argc in the new stack location
+	str	r0, [sp]
+
+	@ now we enter a _dl_init_next loop
+	ldr	r2, .L_DEF_SCOPE
+	ldr	r2, [sl, r2]
+	ldr	r4, [r2, #8]
+	@ call _dl_init_next to get the address of an initalizer
+0:	mov	r0, r4
+	bl	_dl_init_next(PLT)
+	cmp	r0, #0
+	beq	1f
+	@ call the shared-object initializer
+	@ during this call, the stack may get moved around
+	mov	lr, pc
+	mov	pc, r0
+	@ go back and look for another initializer
+	b	0b
+1:	@ clear the startup flag
+	ldr	r2, .L_STARTUP_FLAG
+	ldr	r1, [sl, r2]
+	@ we know r0==0 at this point
+	str	r0, [r1]
+	@ load the finalizer function
+	ldr	r0, .L_FINI_PROC
+	ldr	r0, [sl, r0]
+	@ jump to the user_s entry point
+	mov	pc, r6
+.L_GET_GOT:
+	.word	_GLOBAL_OFFSET_TABLE_ - .L_GOT_GOT - 4	\n\
+.L_SKIP_ARGS:					\n\
+	.word	_dl_skip_args(GOTOFF)		\n\
+.L_DEF_SCOPE:					\n\
+	.word	_dl_default_scope(GOT)		\n\
+.L_STARTUP_FLAG:
+	.word	_dl_starting_up(GOT)
+.L_FINI_PROC:
+	.word	_dl_fini(GOT)
+.previous\n\
+");
+
+/* 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_ARM_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_ARM_JMP_SLOT)
+
+/* A reloc type used for ld.so cmdline arg lookups to reject PLT entries.  */
+#define ELF_MACHINE_JMP_SLOT	R_ARM_JMP_SLOT
+
+/* The i386 never uses Elf32_Rela relocations.  */
+#define ELF_MACHINE_NO_RELA 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)
+    /* We default to ARM
+    This is where processors could be distinguished arm2, arm6, sa110, etc */
+    _dl_platform = "ARM";
+}
+
+static inline void
+elf_machine_fixup_plt (struct link_map *map, const Elf32_Rel *reloc,
+		       Elf32_Addr *reloc_addr, Elf32_Addr value)
+{
+  *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_Rel *reloc,
+		       Elf32_Addr value)
+{
+  return value;
+}
+
+#endif /* !dl_machine_h */
+
+#ifdef RESOLVE
+
+extern char **_dl_argv;
+
+/* 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 Elf32_Rel *reloc,
+		 const Elf32_Sym *sym, const struct r_found_version *version,
+		 Elf32_Addr *const reloc_addr)
+{
+  if (ELF32_R_TYPE (reloc->r_info) == R_ARM_RELATIVE)
+    {
+#ifndef RTLD_BOOTSTRAP
+      if (map != &_dl_rtld_map) /* Already done in rtld itself.  */
+#endif
+	*reloc_addr += map->l_addr;
+    }
+  else if (ELF32_R_TYPE (reloc->r_info) != R_ARM_NONE)
+    {
+      const Elf32_Sym *const refsym = sym;
+      Elf32_Addr value = RESOLVE (&sym, version, ELF32_R_TYPE (reloc->r_info));
+      if (sym)
+	value += sym->st_value;
+
+      switch (ELF32_R_TYPE (reloc->r_info))
+	{
+	case R_ARM_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))
+	    {
+	      const char *strtab;
+
+	      strtab = ((const char *) 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_ARM_GLOB_DAT:
+	case R_ARM_JMP_SLOT:
+
+#if 0
+#define _HEX(i) for (j=28; j>=0; j-=4) b[7-j/4]="0123456789abcdef"[((int)i>>j)&15];
+{
+char b[10];
+int j;
+_HEX(map->l_addr);
+__asm__ (" mov r0, #2; mov r1, %0; mov r2, #9; swi 0x00900004; "
+	: : "r"(b) : "r0", "r1", "r2" );
+_HEX(sym->st_size);
+__asm__ (" mov r0, #2; mov r1, %0; mov r2, #9; swi 0x00900004; "
+	: : "r"(b) : "r0", "r1", "r2" );
+_HEX(&sym->st_value);
+__asm__ (" mov r0, #2; mov r1, %0; mov r2, #9; swi 0x00900004; "
+	: : "r"(b) : "r0", "r1", "r2" );
+_HEX(sym->st_value);
+__asm__ (" mov r0, #2; mov r1, %0; mov r2, #9; swi 0x00900004; "
+	: : "r"(b) : "r0", "r1", "r2" );
+_HEX(sym);
+__asm__ (" mov r0, #2; mov r1, %0; mov r2, #9; swi 0x00900004; "
+	: : "r"(b) : "r0", "r1", "r2" );
+_HEX(reloc_addr);
+__asm__ (" mov r0, #2; mov r1, %0; mov r2, #9; swi 0x00900004; "
+	: : "r"(b) : "r0", "r1", "r2" );
+b[0]=' '; b[1]='\n';
+__asm__ (" mov r0, #2; mov r1, %0; mov r2, #2; swi 0x00900004; "
+	: : "r"(b) : "r0", "r1", "r2" );
+}
+#endif
+	  *reloc_addr = value;
+	  break;
+	case R_ARM_32:
+	  {
+#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.  */
+	      value -= map->l_addr + refsym->st_value;
+#endif
+	    *reloc_addr += value;
+	    break;
+	  }
+	case R_ARM_PC26:
+	  *reloc_addr += (value - (Elf32_Addr) reloc_addr);
+	  break;
+	default:
+	  assert (! "unexpected dynamic reloc type");
+	  break;
+	}
+    }
+}
+
+static inline void
+elf_machine_lazy_rel (struct link_map *map, const Elf32_Rel *reloc)
+{
+  Elf32_Addr *const reloc_addr = (void *) (map->l_addr + reloc->r_offset);
+  switch (ELF32_R_TYPE (reloc->r_info))
+    {
+    case R_ARM_JMP_SLOT:
+      *reloc_addr += map->l_addr;
+      break;
+    default:
+      assert (! "unexpected PLT reloc type");
+      break;
+    }
+}
+
+#endif /* RESOLVE */