1 files changed, 115 insertions, 0 deletions
diff --git a/elf/dl-reloc.c b/elf/dl-reloc.c
new file mode 100644
index 0000000000..8efb3f04a6
--- /dev/null
+++ b/elf/dl-reloc.c
@@ -0,0 +1,115 @@
+/* Relocate a shared object and resolve its references to other loaded objects.
+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 <sys/types.h>
+#include <sys/mman.h>
+#include <unistd.h>
+#include <errno.h>
+#include "dynamic-link.h"
+
+
+void
+_dl_relocate_object (struct link_map *l, int lazy)
+{
+  const size_t pagesize = getpagesize ();
+
+  if (l->l_relocated)
+    return;
+
+  if (l->l_info[DT_TEXTREL])
+    {
+      /* Bletch.  We must make read-only segments writable
+	 long enough to relocate them.  */
+      const Elf32_Phdr *ph;
+      for (ph = l->l_phdr; ph < &l->l_phdr[l->l_phnum]; ++ph)
+	if (ph->p_type == PT_LOAD && (ph->p_flags & PF_W) == 0)
+	  {
+	    caddr_t mapstart = ((caddr_t) l->l_addr +
+				(ph->p_vaddr & ~(pagesize - 1)));
+	    caddr_t mapend = ((caddr_t) l->l_addr +
+			      ((ph->p_vaddr + ph->p_memsz + pagesize - 1)
+			       & ~(pagesize - 1)));
+	    if (mprotect (mapstart, mapend - mapstart,
+			  PROT_READ|PROT_WRITE) < 0)
+	      _dl_signal_error (errno,
+				"cannot make segment writable for relocation");
+	  }
+    }
+
+  {
+    struct link_map *real_next, *scope;
+
+    const char *strtab
+      = ((void *) l->l_addr + l->l_info[DT_STRTAB]->d_un.d_ptr);
+
+
+    Elf32_Addr resolve (const Elf32_Sym **ref)
+      {
+	return _dl_lookup_symbol (strtab + (*ref)->st_name, ref, scope);
+      }
+
+    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;
+
+    elf_dynamic_relocate (l->l_info, l->l_addr, lazy, resolve);
+
+    /* Restore list frobnication done above for DT_SYMBOLIC.  */
+    l->l_next = real_next;
+    l->l_prev->l_next = l;
+  }
+
+  if (l->l_info[DT_JMPREL] && ! lazy)
+    /* Set up the PLT so its unrelocated entries will
+       jump to _dl_runtime_resolve, which will relocate them.  */
+    elf_machine_runtime_setup (l);
+
+  l->l_relocated = 1;
+
+  if (l->l_info[DT_TEXTREL])
+    {
+      /* Undo the protection change we made before relocating.  */
+      const Elf32_Phdr *ph;
+      for (ph = l->l_phdr; ph < &l->l_phdr[l->l_phnum]; ++ph)
+	if (ph->p_type == PT_LOAD && (ph->p_flags & PF_W) == 0)
+	  {
+	    caddr_t mapstart = ((caddr_t) l->l_addr +
+				(ph->p_vaddr & ~(pagesize - 1)));
+	    caddr_t mapend = ((caddr_t) l->l_addr +
+			      ((ph->p_vaddr + ph->p_memsz + pagesize - 1)
+			       & ~(pagesize - 1)));
+	    int prot = 0;
+	    if (ph->p_flags & PF_R)
+	      prot |= PROT_READ;
+	    if (ph->p_flags & PF_X)
+	      prot |= PROT_EXEC;
+	    if (mprotect (mapstart, mapend - mapstart, prot) < 0)
+	      _dl_signal_error (errno,
+				"can't restore segment prot after reloc");
+	  }
+    }
+
+}