kernel: audit/fix non-modular users of module_init in core code

Code that is obj-y (always built-in) or dependent on a bool Kconfig
(built-in or absent) can never be modular.  So using module_init as an
alias for __initcall can be somewhat misleading.

Fix these up now, so that we can relocate module_init from init.h into
module.h in the future.  If we don't do this, we'd have to add module.h to
obviously non-modular code, and that would be a worse thing.

The audit targets the following module_init users for change:
 kernel/user.c                  obj-y
 kernel/kexec.c                 bool KEXEC (one instance per arch)
 kernel/profile.c               bool PROFILING
 kernel/hung_task.c             bool DETECT_HUNG_TASK
 kernel/sched/stats.c           bool SCHEDSTATS
 kernel/user_namespace.c        bool USER_NS

Note that direct use of __initcall is discouraged, vs.  one of the
priority categorized subgroups.  As __initcall gets mapped onto
device_initcall, our use of subsys_initcall (which makes sense for these
files) will thus change this registration from level 6-device to level
4-subsys (i.e.  slightly earlier).  However no observable impact of that
difference has been observed during testing.

Also, two instances of missing ";" at EOL are fixed in kexec.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Eric Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Author: Paul Gortmaker

Diff for: kernel/hung_task.c

@@ -244,5 +244,4 @@ static int __init hung_task_init(void)
 
 	return 0;
 }
-
-module_init(hung_task_init);
+subsys_initcall(hung_task_init);

Diff for: kernel/kexec.c

@@ -1234,7 +1234,7 @@ static int __init crash_notes_memory_init(void)
 	}
 	return 0;
 }
-module_init(crash_notes_memory_init)
+subsys_initcall(crash_notes_memory_init);
 
 
 /*
@@ -1628,7 +1628,7 @@ static int __init crash_save_vmcoreinfo_init(void)
 	return 0;
 }
 
-module_init(crash_save_vmcoreinfo_init)
+subsys_initcall(crash_save_vmcoreinfo_init);
 
 /*
  * Move into place and start executing a preloaded standalone

Diff for: kernel/profile.c

@@ -604,5 +604,5 @@ int __ref create_proc_profile(void) /* false positive from hotcpu_notifier */
 	hotcpu_notifier(profile_cpu_callback, 0);
 	return 0;
 }
-module_init(create_proc_profile);
+subsys_initcall(create_proc_profile);
 #endif /* CONFIG_PROC_FS */

Diff for: kernel/sched/stats.c

@@ -142,4 +142,4 @@ static int __init proc_schedstat_init(void)
 	proc_create("schedstat", 0, NULL, &proc_schedstat_operations);
 	return 0;
 }
-module_init(proc_schedstat_init);
+subsys_initcall(proc_schedstat_init);

Diff for: kernel/user.c

@@ -222,5 +222,4 @@ static int __init uid_cache_init(void)
 
 	return 0;
 }
-
-module_init(uid_cache_init);
+subsys_initcall(uid_cache_init);

Diff for: kernel/user_namespace.c

@@ -902,4 +902,4 @@ static __init int user_namespaces_init(void)
 	user_ns_cachep = KMEM_CACHE(user_namespace, SLAB_PANIC);
 	return 0;
 }
-module_init(user_namespaces_init);
+subsys_initcall(user_namespaces_init);