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authorRoland McGrath <roland@gnu.org>1995-05-02 06:35:55 +0000
committerRoland McGrath <roland@gnu.org>1995-05-02 06:35:55 +0000
commitd66e34cd423425c348bcc83df127dd19711b0b9a (patch)
tree97058e776d3b4fe06ef54bc4951596991652183f /sysdeps/stub
parent08162fa888913a5153d2fcdc4e1a816b57b1fe56 (diff)
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* sysdeps/mach/i386/sysdep.h (SNARF_ARGS, CALL_WITH_SP): Rewritten.
	* sysdeps/i386/dl-machine.h: New file.
	* sysdeps/stub/dl-machine.h: New file.
	* sysdeps/i386/dl-runtime.c: New file.
	* sysdeps/stub/dl-runtime.c: New file.
	* sysdeps/i386/elf/start.S: New file.
	* sysdeps/generic/dl-sysdep.c: New file.
	* sysdeps/mach/hurd/dl-sysdep.c: New file.
Diffstat (limited to 'sysdeps/stub')
-rw-r--r--sysdeps/stub/dl-machine.h115
-rw-r--r--sysdeps/stub/dl-runtime.c64
2 files changed, 179 insertions, 0 deletions
diff --git a/sysdeps/stub/dl-machine.h b/sysdeps/stub/dl-machine.h
new file mode 100644
index 0000000000..d9227233e4
--- /dev/null
+++ b/sysdeps/stub/dl-machine.h
@@ -0,0 +1,115 @@
+/* Machine-dependent ELF dynamic relocation inline functions.  Stub version.
+Copyright (C) 1995 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., 675 Mass Ave,
+Cambridge, MA 02139, USA.  */
+
+#define ELF_MACHINE_NAME "stub"
+
+#include <assert.h>
+#include <string.h>
+#include <link.h>
+
+
+/* Return nonzero iff E_MACHINE is compatible with the running host.  */
+static inline int
+elf_machine_matches_host (Elf32_Half e_machine)
+{
+  switch (e_machine)
+    {
+    default:
+      return 0;
+    }
+}
+
+
+/* Return the run-time address of the _GLOBAL_OFFSET_TABLE_.  */
+static inline Elf32_Addr *
+elf_machine_got (void)
+{
+#error "GOT not got"
+}
+
+
+/* Return the run-time load address of the shared object.  */
+static inline Elf32_Addr
+elf_machine_load_address (void)
+{
+#error "Where am I?"
+}
+
+/* This can modify DYNAMIC_INFO to avoid relocating code in
+   the functions above if they are doing bizarre magic.  */
+#define ELF_MACHINE_BEFORE_RTLD_RELOC(dynamic_info) /* nothing */
+
+/* Perform the relocation specified by RELOC and SYM (which is fully resolved).
+   LOADADDR is the load address of the object; INFO is an array indexed
+   by DT_* of the .dynamic section info.  */
+
+static inline void
+elf_machine_rel (Elf32_Addr loadaddr, Elf32_Dyn *info[DT_NUM],
+		 const Elf32_Rel *reloc,
+		 Elf32_Addr sym_loadaddr, const Elf32_Sym *sym)
+{
+  Elf32_Addr *const reloc_addr = (Elf32_Addr *) reloc->r_offset;
+  const Elf32_Addr sym_value = sym_loadaddr + sym->st_value;
+
+  switch (ELF32_R_TYPE (reloc->r_info))
+    {
+    case R_MACHINE_COPY:
+      memcpy (reloc_addr, (void *) sym_value, sym->st_size);
+      break;
+    default:
+      assert (! "unexpected dynamic reloc type");
+      break;
+    }
+}
+
+
+static inline void
+elf_machine_rela (Elf32_Addr loadaddr, Elf32_Dyn *info[DT_NUM],
+		  const Elf32_Rela *reloc, 
+		  Elf32_Addr sym_loadaddr, const Elf32_Sym *sym)
+{
+  _dl_signal_error (0, "Elf32_Rela relocation requested -- unused on "
+		    ELF_MACHINE_NAME);
+}
+
+
+/* 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 void
+elf_machine_runtime_setup (struct link_map *l)
+{
+  extern void _dl_runtime_resolve (Elf32_Word);
+  /* 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 .rel.plt section, push _GLOBAL_OFFSET_TABLE_[1],
+     and then jump to _GLOBAL_OFFSET_TABLE[2].  */
+  Elf32_Addr *got = (Elf32_Addr *) l->l_info[DT_PLTGOT]->d_un.d_ptr;
+  got[1] = (Elf32_Addr) l;	/* Identify this shared object.  */
+  /* 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;
+}
+
+
+/* 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 #error need some startup code
diff --git a/sysdeps/stub/dl-runtime.c b/sysdeps/stub/dl-runtime.c
new file mode 100644
index 0000000000..f660ef2197
--- /dev/null
+++ b/sysdeps/stub/dl-runtime.c
@@ -0,0 +1,64 @@
+/* On-demand PLT fixup for shared objects.  Stub version.
+Copyright (C) 1995 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., 675 Mass Ave,
+Cambridge, MA 02139, USA.  */
+
+#include <link.h>
+#include "dynamic-link.h"
+
+/* This function is not called in the normal way.  The PLT jumps here, not
+   using a call.  */
+void
+_dl_runtime_resolve ()
+{
+  struct link_map *l = ???;
+  Elf32_Word reloc_offset = ???;
+
+  const Elf32_Sym *const symtab
+    = (const Elf32_Sym *) 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 Elf32_Rel *const reloc = (void *) (l->l_info[DT_JMPREL]->d_un.d_ptr
+					   + reloc_offset);
+
+  const Elf32_Sym *definer;
+  Elf32_Addr loadbase;
+  struct link_map *scope, *real_next;
+
+  /* Look up the symbol's run-time value.  */
+
+  real_next = l->l_next;
+  if (l->l_info[DT_SYMBOLIC])
+    {
+      l->l_prev->l_next = real_next;
+      l->l_next = _dl_loaded;
+      scope = l;
+    }
+  else
+    scope = _dl_loaded;
+  
+  definer = &symtab[ELF32_R_SYM (reloc->r_info)];
+  loadbase = _dl_lookup_symbol (strtab + definer->st_name, &definer, scope);
+  
+  /* Restore list frobnication done above for DT_SYMBOLIC.  */
+  l->l_next = real_next;
+  l->l_prev->l_next = l;
+
+  /* Apply the relocation with that value.  */
+  elf_machine_rel (l->l_addr, l->l_info, reloc, loadbase, definer);
+}