*: add optimization barrier to all "G trick" locations

libbb/Kbuild

@@ -69,6 +69,7 @@ lib-y += pidfile.o
 lib-y += printable.o
 lib-y += process_escape_sequence.o
 lib-y += procps.o
+lib-y += ptr_to_globals.o
 lib-y += read.o
 lib-y += recursive_action.o
 lib-y += remove_file.o

libbb/appletlib.c

@@ -127,6 +127,7 @@ void lbb_prepare(const char *applet, char **argv)
 {
 #ifdef __GLIBC__
 	(*(int **)&bb_errno) = __errno_location();
+	barrier();
 #endif
 	applet_name = applet;
 

libbb/lineedit.c

@@ -146,6 +146,7 @@ static struct statics *const ptr_to_statics __attribute__ ((section (".data")));
 
 #define INIT_S() do { \
 	(*(struct statics**)&ptr_to_statics) = xzalloc(sizeof(S)); \
+	barrier(); \
 	cmdedit_termw = 80; \
 	USE_FEATURE_EDITING_FANCY_PROMPT(num_ok_lines = 1;) \
 	USE_FEATURE_GETUSERNAME_AND_HOMEDIR(home_pwd_buf = (char*)null_str;) \

libbb/messages.c

@@ -71,7 +71,3 @@ const char bb_path_wtmp_file[] ALIGN1 =
  * Since gcc insists on aligning struct global's members, it would be a pity
  * (and an alignment fault on some CPUs) to mess it up. */
 char bb_common_bufsiz1[COMMON_BUFSIZE] __attribute__(( aligned(sizeof(long long)) ));
-
-struct globals;
-/* Make it reside in R/W memory: */
-struct globals *const ptr_to_globals __attribute__ ((section (".data")));

libbb/ptr_to_globals.c

@@ -0,0 +1,11 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Copyright (C) 2008 by Denys Vlasenko <vda.linux@googlemail.com>
+ *
+ * Licensed under GPLv2, see file LICENSE in this tarball for details.
+ */
+
+/* We cheat here. It is declared as const ptr in libbb.h,
+ * but here we make it live in R/W memory */
+struct globals;
+struct globals *ptr_to_globals;