Move code to disable ASR to nat/

This patch moves the shared code present on
gdb/linux-nat.c:linux_nat_create_inferior and
gdb/gdbserver/linux-low.c:linux_create_inferior to
nat/linux-personality.c.  This code is responsible for disabling
address space randomization based on user setting, and using
<sys/personality.h> to do that.  I decided to put the prototype of the
maybe_disable_address_space_randomization on nat/linux-osdata.h
because it seemed the best place to put it.

I regression-tested this patch on Fedora 20 x86_64, and found no
regressions.

gdb/ChangeLog
2015-01-15  Sergio Durigan Junior  <sergiodj@redhat.com>

	* Makefile.in (HFILES_NO_SRCDIR): Add nat/linux-personality.h.
	(linux-personality.o): New rule.
	* common/common-defs.h: Include <stdint.h>.
	* config/aarch64/linux.mh (NATDEPFILES): Include
	linux-personality.o.
	* config/alpha/alpha-linux.mh (NATDEPFILES): Likewise.
	* config/arm/linux.mh (NATDEPFILES): Likewise.
	* config/i386/linux64.mh (NATDEPFILES): Likewise.
	* config/i386/linux.mh (NATDEPFILES): Likewise.
	* config/ia64/linux.mh (NATDEPFILES): Likewise.
	* config/m32r/linux.mh (NATDEPFILES): Likewise.
	* config/m68k/linux.mh (NATDEPFILES): Likewise.
	* config/mips/linux.mh (NATDEPFILES): Likewise.
	* config/pa/linux.mh (NATDEPFILES): Likewise.
	* config/powerpc/linux.mh (NATDEPFILES): Likewise.
	* config/powerpc/ppc64-linux.mh (NATDEPFILES): Likewise.
	* config/powerpc/spu-linux.mh (NATDEPFILES): Likewise.
	* config/s390/linux.mh (NATDEPFILES): Likewise.
	* config/sparc/linux64.mh (NATDEPFILES): Likewise.
	* config/sparc/linux.mh (NATDEPFILES): Likewise.
	* config/tilegx/linux.mh (NATDEPFILES): Likewise.
	* config/xtensa/linux.mh (NATDEPFILES): Likewise.
	* defs.h: Remove #include <stdint.h> (moved to
	common/common-defs.h).
	* linux-nat.c: Include nat/linux-personality.h.  Remove #include
	<sys/personality.h>; do not define ADDR_NO_RANDOMIZE (moved to
	nat/linux-personality.c).
	(linux_nat_create_inferior): Remove code to disable address space
	randomization (moved to nat/linux-personality.c).  Create cleanup
	to disable address space randomization.
	* nat/linux-personality.c: New file.
	* nat/linux-personality.h: Likewise.

gdb/gdbserver/ChangeLog
2015-01-15  Sergio Durigan Junior  <sergiodj@redhat.com>

	* Makefile.in (SFILES): Add linux-personality.c.
	(linux-personality.o): New rule.
	* configure.srv (srv_linux_obj): Add linux-personality.o to the
	list of objects to be built.
	* linux-low.c: Include nat/linux-personality.h.
	(linux_create_inferior): Remove code to disable address space
	randomization (moved to ../nat/linux-personality.c).  Create
	cleanup to disable address space randomization.

1 files changed, 94 insertions, 0 deletions

diff --git a/gdb/nat/linux-personality.c b/gdb/nat/linux-personality.c
new file mode 100644
index 0000000..f61a2c6
--- /dev/null
+++ b/gdb/nat/linux-personality.c
@@ -0,0 +1,94 @@
+/* Disable address space randomization based on inferior personality.
+
+   Copyright (C) 2008-2015 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   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 3 of the License, 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, see <http://www.gnu.org/licenses/>.  */
+
+#include "common-defs.h"
+#include "nat/linux-personality.h"
+
+#ifdef HAVE_PERSONALITY
+# include <sys/personality.h>
+# ifndef HAVE_DECL_ADDR_NO_RANDOMIZE
+#  define ADDR_NO_RANDOMIZE 0x0040000
+# endif /* ! HAVE_DECL_ADDR_NO_RANDOMIZE */
+#endif /* HAVE_PERSONALITY */
+
+#ifdef HAVE_PERSONALITY
+
+/* Restore address space randomization of the inferior.  ARG is the
+   original inferior's personality value before the address space
+   randomization was disabled.  */
+
+static void
+restore_personality (void *arg)
+{
+  int personality_orig = (int) (uintptr_t) arg;
+
+  errno = 0;
+  personality (personality_orig);
+  if (errno != 0)
+    warning (_("Error restoring address space randomization: %s"),
+	     safe_strerror (errno));
+}
+#endif /* HAVE_PERSONALITY */
+
+/* Return a cleanup responsible for restoring the inferior's
+   personality (and restoring the inferior's address space
+   randomization) if HAVE_PERSONALITY and if PERSONALITY_SET is not
+   zero; return a null cleanup if not HAVE_PERSONALITY or if
+   PERSONALITY_SET is zero.  */
+
+static struct cleanup *
+make_disable_asr_cleanup (int personality_set, int personality_orig)
+{
+#ifdef HAVE_PERSONALITY
+  if (personality_set != 0)
+    return make_cleanup (restore_personality,
+			 (void *) (uintptr_t) personality_orig);
+#endif /* HAVE_PERSONALITY */
+
+  return make_cleanup (null_cleanup, NULL);
+}
+
+/* See comment on nat/linux-personality.h.  */
+
+struct cleanup *
+maybe_disable_address_space_randomization (int disable_randomization)
+{
+  int personality_orig = 0;
+  int personality_set = 0;
+
+#ifdef HAVE_PERSONALITY
+  if (disable_randomization)
+    {
+      errno = 0;
+      personality_orig = personality (0xffffffff);
+      if (errno == 0 && !(personality_orig & ADDR_NO_RANDOMIZE))
+	{
+	  personality_set = 1;
+	  personality (personality_orig | ADDR_NO_RANDOMIZE);
+	}
+      if (errno != 0 || (personality_set
+			 && !(personality (0xffffffff) & ADDR_NO_RANDOMIZE)))
+	warning (_("Error disabling address space randomization: %s"),
+		 safe_strerror (errno));
+    }
+#endif /* HAVE_PERSONALITY */
+
+  return make_disable_asr_cleanup (personality_set,
+				   personality_orig);
+}