Change maybe_disable_address_space_randomization to a class

This changes maybe_disable_address_space_randomization to be an RAII
class, rather than having it return a cleanup.

Regression tested by the buildbot.

ChangeLog
2017-11-26  Tom Tromey  <tom@tromey.com>

	* nat/linux-personality.h (class
	maybe_disable_address_space_randomization): New class.
	(maybe_disable_address_space_randomization): Don't declare
	function.
	* nat/linux-personality.c (restore_personality)
	(make_disable_asr_cleanup): Remove.
	(maybe_disable_address_space_randomization): Now a constructor.
	(~maybe_disable_address_space_randomization): New destructor.
	* linux-nat.c (linux_nat_create_inferior): Update.

gdbserver/ChangeLog
2017-11-26  Tom Tromey  <tom@tromey.com>

	* linux-low.c (linux_create_inferior): Update.

gdb/ChangeLog

@@ -1,3 +1,15 @@
+2017-11-26  Tom Tromey  <tom@tromey.com>
+
+	* nat/linux-personality.h (class
+	maybe_disable_address_space_randomization): New class.
+	(maybe_disable_address_space_randomization): Don't declare
+	function.
+	* nat/linux-personality.c (restore_personality)
+	(make_disable_asr_cleanup): Remove.
+	(maybe_disable_address_space_randomization): Now a constructor.
+	(~maybe_disable_address_space_randomization): New destructor.
+	* linux-nat.c (linux_nat_create_inferior): Update.
+
 2017-11-26  Tom Tromey  <tom@tromey.com>
 
 	* gcore.c (write_gcore_file_1): Use gdb::unique_xmalloc_ptr.

gdb/gdbserver/ChangeLog

@@ -1,3 +1,7 @@
+2017-11-26  Tom Tromey  <tom@tromey.com>
+
+	* linux-low.c (linux_create_inferior): Update.
+
 2017-11-24  Ulrich Weigand  <uweigand@de.ibm.com>
 
 	* spu-low.c (spu_create_inferior): Fix typo in argument name.

gdb/gdbserver/linux-low.c

@@ -998,16 +998,17 @@ linux_create_inferior (const char *program,
   struct lwp_info *new_lwp;
   int pid;
   ptid_t ptid;
-  struct cleanup *restore_personality
-    = maybe_disable_address_space_randomization (disable_randomization);
-  std::string str_program_args = stringify_argv (program_args);
 
-  pid = fork_inferior (program,
+  {
-		       str_program_args.c_str (),
+    maybe_disable_address_space_randomization restore_personality
-		       get_environ ()->envp (), linux_ptrace_fun,
+      (disable_randomization);
-		       NULL, NULL, NULL, NULL);
+    std::string str_program_args = stringify_argv (program_args);
 
-  do_cleanups (restore_personality);
+    pid = fork_inferior (program,
+			 str_program_args.c_str (),
+			 get_environ ()->envp (), linux_ptrace_fun,
+			 NULL, NULL, NULL, NULL);
+  }
 
   linux_add_process (pid, 0);
 

gdb/linux-nat.c

@@ -1118,8 +1118,8 @@ linux_nat_create_inferior (struct target_ops *ops,
 			   const char *exec_file, const std::string &allargs,
 			   char **env, int from_tty)
 {
-  struct cleanup *restore_personality
+  maybe_disable_address_space_randomization restore_personality
-    = maybe_disable_address_space_randomization (disable_randomization);
+    (disable_randomization);
 
   /* The fork_child mechanism is synchronous and calls target_wait, so
      we have to mask the async mode.  */
@@ -1128,8 +1128,6 @@ linux_nat_create_inferior (struct target_ops *ops,
   linux_nat_pass_signals (ops, 0, NULL);
 
   linux_ops->to_create_inferior (ops, exec_file, allargs, env, from_tty);
-
-  do_cleanups (restore_personality);
 }
 
 /* Callback for linux_proc_attach_tgid_threads.  Attach to PTID if not

gdb/nat/linux-personality.c

@@ -27,68 +27,43 @@
 # 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::
 maybe_disable_address_space_randomization (int disable_randomization)
+  : m_personality_set (false),
+    m_personality_orig (0)
 {
-  int personality_orig = 0;
-  int personality_set = 0;
-
 #ifdef HAVE_PERSONALITY
   if (disable_randomization)
     {
       errno = 0;
-      personality_orig = personality (0xffffffff);
+      m_personality_orig = personality (0xffffffff);
-      if (errno == 0 && !(personality_orig & ADDR_NO_RANDOMIZE))
+      if (errno == 0 && !(m_personality_orig & ADDR_NO_RANDOMIZE))
 	{
-	  personality_set = 1;
+	  m_personality_set = true;
-	  personality (personality_orig | ADDR_NO_RANDOMIZE);
+	  personality (m_personality_orig | ADDR_NO_RANDOMIZE);
 	}
-      if (errno != 0 || (personality_set
+      if (errno != 0 || (m_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);
+maybe_disable_address_space_randomization::
+~maybe_disable_address_space_randomization ()
+{
+#ifdef HAVE_PERSONALITY
+
+  if (m_personality_set)
+    {
+      errno = 0;
+      personality (m_personality_orig);
+      if (errno != 0)
+	warning (_("Error restoring address space randomization: %s"),
+		 safe_strerror (errno));
+    }
+#endif /* HAVE_PERSONALITY */
 }

gdb/nat/linux-personality.h

@@ -20,12 +20,27 @@
 #ifndef NAT_LINUX_PERSONALITY_H
 #define NAT_LINUX_PERSONALITY_H
 
-/* Disable the inferior's address space randomization if
+class maybe_disable_address_space_randomization
-   DISABLE_RANDOMIZATION is not zero and if we have
+{
-   <sys/personality.h>.  Return a cleanup which, when called, will
+public:
-   re-enable the inferior's address space randomization.  */
 
-extern struct cleanup *maybe_disable_address_space_randomization
+  /* Disable the inferior's address space randomization if
-  (int disable_randomization);
+     DISABLE_RANDOMIZATION is not zero and if we have
+     <sys/personality.h>. */
+  maybe_disable_address_space_randomization (int disable_randomization);
+
+  /* On destruction, re-enable address space randomization.  */
+  ~maybe_disable_address_space_randomization ();
+
+  DISABLE_COPY_AND_ASSIGN (maybe_disable_address_space_randomization);
+
+private:
+
+  /* True if the personality was set in the constructor.  */
+  bool m_personality_set;
+
+  /* If m_personality_set is true, the original personality value.  */
+  int m_personality_orig;
+};
 
 #endif /* ! NAT_LINUX_PERSONALITY_H */