1 files changed, 459 insertions, 0 deletions

diff --git a/trunk/src/execstack.c b/trunk/src/execstack.c
new file mode 100644
index 0000000..f38fead
--- /dev/null
+++ b/trunk/src/execstack.c
@@ -0,0 +1,459 @@
+/* Copyright (C) 2003, 2005 Red Hat, Inc.
+   Written by Jakub Jelinek <jakub@redhat.com>, 2003.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program 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 General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+
+#include <config.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <string.h>
+#include <locale.h>
+#include <error.h>
+#include <argp.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/wait.h>
+
+#include "prelink.h"
+
+int set;
+int execflag;
+
+const char *argp_program_version = "execstack 1.0 (20061201) Wind River";
+
+const char *argp_program_bug_address = "<support@windriver.com>";
+
+static char argp_doc[] = "execstack -- program to query or set executable stack flag";
+
+static struct argp_option options[] = {
+  {"set-execstack",	's', 0, 0,  "Set executable stack flag bit" },
+  {"execstack",		's', 0, OPTION_HIDDEN, "" },
+  {"clear-execstack",	'c', 0, 0,  "Clear executable stack flag bit" },
+  {"noexecstack",	'c', 0, OPTION_HIDDEN, "" },
+  {"query",		'q', 0, 0,  "Query executable stack flag bit" },
+  { 0 }
+};
+
+static error_t
+parse_opt (int key, char *arg, struct argp_state *state)
+{
+  switch (key)
+    {
+    case 's':
+      set = 1;
+      execflag = 1;
+      break;
+    case 'c':
+      set = 1;
+      execflag = 0;
+      break;
+    case 'q':
+      set = 0;
+      break;
+    default:
+      return ARGP_ERR_UNKNOWN;
+    }
+  return 0;
+}
+
+static struct argp argp = { options, parse_opt, 0, argp_doc };
+
+static int execstack_set (DSO *dso, int flag);
+
+static void
+execstack_fill_phdr (DSO *dso, int i, int flag)
+{
+  memset (&dso->phdr[i], 0, sizeof (dso->phdr[i]));
+  dso->phdr[i].p_type = PT_GNU_STACK;
+  dso->phdr[i].p_flags = PF_W | PF_R | (flag ? PF_X : 0);
+  dso->phdr[i].p_align = gelf_fsize (dso->elf, ELF_T_ADDR, 1, EV_CURRENT);
+}
+
+static int
+execstack_make_rdwr (DSO *dso, int flag)
+{
+  int i, fd = -1, status;
+  pid_t pid;
+  DSO *ndso = NULL;
+  char *p = NULL;
+  char filename[strlen (dso->filename) + sizeof ".#execstack#.XXXXXX"];
+
+  for (i = 0; i < dso->ehdr.e_shnum; ++i)
+    {
+      const char *name = strptr (dso, dso->ehdr.e_shstrndx,
+				 dso->shdr[i].sh_name);
+      if (strcmp (name, ".gnu.prelink_undo") == 0)
+	break;
+    }
+
+  if (i == dso->ehdr.e_shnum)
+    return reopen_dso (dso, NULL, NULL) ? 1 : -1;
+
+  /* We need to unprelink the file first, so that prelink --undo
+     or reprelinking it doesn't destroy the PT_GNU_STACK segment
+     header we've created.  */
+  sprintf (filename, "%s.#execstack#.XXXXXX", dso->filename);
+
+  fd = wrap_mkstemp (filename);
+  if (fd == -1)
+    {
+      error (0, 0, "%s: Cannot create temporary file",
+	     dso->filename);
+      goto error_out;
+    }
+
+  p = strdup (dso->filename);
+  if (p == NULL)
+    {
+      error (0, ENOMEM, "%s: Cannot create temporary file",
+	     dso->filename);
+      goto error_out;
+    }
+
+  pid = vfork ();
+  if (pid == 0)
+    {
+      close (fd);
+      execlp ("prelink", "prelink", "-u", "-o", filename,
+	      dso->filename, NULL);
+      execl (SBINDIR "/prelink", "prelink", "-u", "-o", filename,
+	     dso->filename, NULL);
+      _exit (-1);
+    }
+
+  if (pid < 0)
+    {
+      error (0, errno, "%s: Cannot run prelink --undo",
+	     dso->filename);
+      goto error_out;
+    }
+
+  if (waitpid (pid, &status, 0) < 0
+      || !WIFEXITED (status)
+      || WEXITSTATUS (status))
+    {
+      error (0, 0, "%s: prelink --undo failed", dso->filename);
+      goto error_out;
+    }
+
+  ndso = open_dso (filename);
+  if (ndso == NULL)
+    {
+      error (0, 0, "%s: Couldn't open prelink --undo output",
+	     dso->filename);
+      goto error_out;
+    }
+
+  for (i = 0; i < ndso->ehdr.e_shnum; ++i)
+    {
+      const char *name = strptr (ndso, ndso->ehdr.e_shstrndx,
+				 ndso->shdr[i].sh_name);
+      if (strcmp (name, ".gnu.prelink_undo") == 0)
+	break;
+    }
+
+  if (i != ndso->ehdr.e_shnum)
+    {
+      error (0, 0, "%s: prelink --undo output contains .gnu.prelink_undo section",
+	     dso->filename);
+      goto error_out;
+    }
+
+  if (ndso->ehdr.e_type != dso->ehdr.e_type)
+    {
+      error (0, 0, "%s: Object type changed during prelink --undo operation",
+	     dso->filename);
+    }
+
+  if (ndso->filename != ndso->soname)
+    free ((char *) ndso->filename);
+  ndso->filename = p;
+  p = NULL;
+
+  wrap_unlink (filename);
+  close (fd);
+  fd = -1;
+  close_dso (dso);
+  return execstack_set (ndso, flag);
+
+error_out:
+  free (p);
+  if (ndso != NULL)
+    close_dso (ndso);
+  if (fd != -1)
+    {
+      wrap_unlink (filename);
+      close (fd);
+    }
+  close_dso (dso);
+  return 1;
+}
+
+static int
+execstack_set (DSO *dso, int flag)
+{
+  int i, null = -1, last, ret;
+  GElf_Addr lowoff = ~(GElf_Addr) 0, start = 0, align = 0;
+  GElf_Addr adjust;
+
+  for (i = 0; i < dso->ehdr.e_phnum; ++i)
+    if (dso->phdr[i].p_type == PT_GNU_STACK)
+      {
+	/* Found PT_GNU_STACK.  Check if we need any change or not.  */
+	if (flag ^ ((dso->phdr[i].p_flags & PF_X) != 0))
+	  {
+	    ret = execstack_make_rdwr (dso, flag);
+	    if (ret != -1)
+	      return ret;
+	    dso->phdr[i].p_flags ^= PF_X;
+	    goto out_write;
+	  }
+	else
+	  goto out_close;
+      }
+    else if (dso->phdr[i].p_type == PT_NULL)
+      null = i;
+
+  if (null != -1)
+    {
+      /* Overwrite PT_NULL segment with PT_GNU_STACK.  */
+      ret = execstack_make_rdwr (dso, flag);
+      if (ret != -1)
+	return ret;
+      execstack_fill_phdr (dso, i, flag);
+      goto out_write;
+    }
+
+  if (dso->ehdr.e_shnum == 0)
+    {
+      error (0, 0, "%s: Section header table missing", dso->filename);
+      goto error_out;
+    }
+
+  for (i = 1; i < dso->ehdr.e_shnum; ++i)
+    {
+      if (lowoff > dso->shdr[i].sh_offset)
+	{
+	  if (dso->shdr[i].sh_flags & (SHF_WRITE | SHF_ALLOC | SHF_EXECINSTR))
+	    {
+	      lowoff = dso->shdr[i].sh_offset;
+	      start = dso->shdr[i].sh_addr;
+	    }
+	  else
+	    {
+	      error (0, 0, "%s: Non-alloced sections before alloced ones",
+		     dso->filename);
+	      goto error_out;
+	    }
+	}
+
+      if (dso->shdr[i].sh_addralign > align)
+	align = dso->shdr[i].sh_addralign;
+    }
+
+  if (dso->ehdr.e_phoff >= lowoff)
+    {
+      error (0, 0, "%s: Program header table not before all sections",
+	     dso->filename);
+      goto error_out;
+    }
+
+  if (dso->ehdr.e_shoff <= lowoff)
+    {
+      error (0, 0, "%s: Section header table before first section",
+	     dso->filename);
+      goto error_out;
+    }
+
+  if (dso->ehdr.e_phoff + (dso->ehdr.e_phnum + 1) * dso->ehdr.e_phentsize
+      <= lowoff)
+    {
+      /* There is enough space for the headers even without reshuffling
+	 anything.  */
+      for (i = 0; i < dso->ehdr.e_phnum; ++i)
+	if (dso->phdr[i].p_type == PT_PHDR)
+	  {
+	    if (dso->phdr[i].p_filesz
+		== dso->ehdr.e_phnum * dso->ehdr.e_phentsize)
+	      dso->phdr[i].p_filesz += dso->ehdr.e_phentsize;
+	    if (dso->phdr[i].p_memsz
+		== dso->ehdr.e_phnum * dso->ehdr.e_phentsize)
+	      dso->phdr[i].p_memsz += dso->ehdr.e_phentsize;
+	  }
+      i = dso->ehdr.e_phnum++;
+      ret = execstack_make_rdwr (dso, flag);
+      if (ret != -1)
+	return ret;
+      execstack_fill_phdr (dso, i, flag);
+      goto out_write;
+    }
+
+  if (dso->ehdr.e_type != ET_DYN)
+    {
+      error (0, 0, "%s: Reshuffling of objects to make room for\n"
+		   "program header entry only supported for shared libraries",
+	     dso->filename);
+      goto error_out;
+    }
+
+  adjust = dso->ehdr.e_phoff + (dso->ehdr.e_phnum + 1) * dso->ehdr.e_phentsize
+	   - lowoff;
+  if (align)
+    adjust = (adjust + align - 1) & ~(align - 1);
+
+  /* Need to make sure adjust doesn't cause different Phdr segments
+     to overlap on the same page.  */
+  last = -1;
+  for (i = 0; i < dso->ehdr.e_phnum; ++i)
+    if (dso->phdr[i].p_type == PT_LOAD
+	&& dso->phdr[i].p_vaddr + dso->phdr[i].p_memsz >= start)
+      {
+	if (last != -1
+	    && (((dso->phdr[last].p_vaddr + dso->phdr[last].p_memsz - 1)
+		 ^ dso->phdr[i].p_vaddr)
+		& ~(dso->arch->max_page_size - 1))
+	    && !(((dso->phdr[last].p_vaddr + dso->phdr[last].p_memsz
+		   + adjust - 1)
+		  ^ (dso->phdr[i].p_vaddr + adjust))
+		 & ~(dso->arch->max_page_size - 1)))
+	  {
+	    if (align >= dso->arch->max_page_size)
+	      {
+		error (0, 0, "%s: Cannot grow reloc sections", dso->filename);
+		goto error_out;
+	      }
+	    adjust = (adjust + dso->arch->max_page_size - 1)
+		     & ~(dso->arch->max_page_size - 1);
+	  }
+	last = i;
+      }
+
+  for (i = 0; i < dso->ehdr.e_phnum; ++i)
+    if (dso->phdr[i].p_type == PT_PHDR)
+      {
+	if (dso->phdr[i].p_filesz == dso->ehdr.e_phnum * dso->ehdr.e_phentsize)
+	  dso->phdr[i].p_filesz += dso->ehdr.e_phentsize;
+	if (dso->phdr[i].p_memsz == dso->ehdr.e_phnum * dso->ehdr.e_phentsize)
+	  dso->phdr[i].p_memsz += dso->ehdr.e_phentsize;
+      }
+
+  i = dso->ehdr.e_phnum++;
+  ret = execstack_make_rdwr (dso, flag);
+  if (ret != -1)
+    return ret;
+
+  if (adjust_dso (dso, start, adjust))
+    goto error_out;
+
+  execstack_fill_phdr (dso, i, flag);
+
+out_write:
+  if (dynamic_info_is_set (dso, DT_CHECKSUM_BIT)
+      && dso_is_rdwr (dso)
+      && prelink_set_checksum (dso))
+    goto error_out;
+
+  dso->permissive = 1;
+
+  return update_dso (dso, NULL);
+
+out_close:
+  close_dso (dso);
+  return 0;
+
+error_out:
+  close_dso (dso);
+  return 1;
+}
+
+static int
+execstack_query (DSO *dso)
+{
+  int stack = '?', i;
+
+  for (i = 0; i < dso->ehdr.e_phnum; ++i)
+    if (dso->phdr[i].p_type == PT_GNU_STACK)
+      {
+	stack = (dso->phdr[i].p_flags & PF_X) ? 'X' : '-';
+	break;
+      }
+  printf ("%c %s\n", stack, dso->filename);
+  close_dso (dso);
+  return 0;
+}
+
+int
+main (int argc, char *argv[])
+{
+  int remaining, failures = 0;
+
+  setlocale (LC_ALL, "");
+
+  argp_parse (&argp, argc, argv, 0, &remaining, 0);
+
+  elf_version (EV_CURRENT);
+
+  if (remaining == argc)
+    error (EXIT_FAILURE, 0, "no files given");
+
+  while (remaining < argc)
+    {
+      DSO *dso = open_dso (argv[remaining++]);
+      int ret;
+
+      if (dso == NULL)
+	{
+	  ++failures;
+	  continue;
+	}
+
+      if (dso->ehdr.e_type != ET_DYN
+	  && dso->ehdr.e_type != ET_EXEC)
+	{
+	  ++failures;
+	  error (0, 0, "%s is not a shared library nor executable", dso->filename);
+	  continue;
+	}
+
+      if (set)
+	ret = execstack_set (dso, execflag);
+      else
+	ret = execstack_query (dso);
+
+      if (ret)
+	++failures;
+    }
+
+  return failures;
+}
+
+/* FIXME: Dummy.  When arch dependent files are split into adjust and prelink
+   parts, this can go away.  */
+struct prelink_conflict *
+prelink_conflict (struct prelink_info *info, GElf_Word r_sym, int reloc_type)
+{
+  abort ();
+}
+
+GElf_Rela *
+prelink_conflict_add_rela (struct prelink_info *info)
+{
+  abort ();
+}
+
+GElf_Addr mmap_reg_start;
+GElf_Addr mmap_reg_end;
+int exec_shield;