kmod: move call_usermodehelper_fns() to .c file and unexport all it's helpers

If we move call_usermodehelper_fns() to kmod.c file and EXPORT_SYMBOL it
we can avoid exporting all it's helper functions:
	call_usermodehelper_setup
	call_usermodehelper_setfns
	call_usermodehelper_exec
And make all of them static to kmod.c

Since the optimizer will see all these as a single call site it will
inline them inside call_usermodehelper_fns().  So we loose the call to
_fns but gain 3 calls to the helpers.  (Not that it matters)

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 22 insertions, 3 deletions

diff --git a/kernel/kmod.c b/kernel/kmod.c
index 21a0f8e99102..1f596e4de306 100644
--- a/kernel/kmod.c
+++ b/kernel/kmod.c
@@ -478,6 +478,7 @@ static void helper_unlock(void)
  * structure.  This should be passed to call_usermodehelper_exec to
  * exec the process and free the structure.
  */
+static
 struct subprocess_info *call_usermodehelper_setup(char *path, char **argv,
                                                   char **envp, gfp_t gfp_mask)
 {
@@ -493,7 +494,6 @@ struct subprocess_info *call_usermodehelper_setup(char *path, char **argv,
   out:
         return sub_info;
 }
-EXPORT_SYMBOL(call_usermodehelper_setup);
 
 /**
  * call_usermodehelper_setfns - set a cleanup/init function
@@ -511,6 +511,7 @@ EXPORT_SYMBOL(call_usermodehelper_setup);
  * Function must be runnable in either a process context or the
  * context in which call_usermodehelper_exec is called.
  */
+static
 void call_usermodehelper_setfns(struct subprocess_info *info,
                     int (*init)(struct subprocess_info *info, struct cred *new),
                     void (*cleanup)(struct subprocess_info *info),
@@ -520,7 +521,6 @@ void call_usermodehelper_setfns(struct subprocess_info *info,
         info->init = init;
         info->data = data;
 }
-EXPORT_SYMBOL(call_usermodehelper_setfns);
 
 /**
  * call_usermodehelper_exec - start a usermode application
@@ -534,6 +534,7 @@ EXPORT_SYMBOL(call_usermodehelper_setfns);
  * asynchronously if wait is not set, and runs as a child of keventd.
  * (ie. it runs with full root capabilities).
  */
+static
 int call_usermodehelper_exec(struct subprocess_info *sub_info, int wait)
 {
         DECLARE_COMPLETION_ONSTACK(done);
@@ -575,7 +576,25 @@ unlock:
         helper_unlock();
         return retval;
 }
-EXPORT_SYMBOL(call_usermodehelper_exec);
+
+int call_usermodehelper_fns(
+        char *path, char **argv, char **envp, int wait,
+        int (*init)(struct subprocess_info *info, struct cred *new),
+        void (*cleanup)(struct subprocess_info *), void *data)
+{
+        struct subprocess_info *info;
+        gfp_t gfp_mask = (wait == UMH_NO_WAIT) ? GFP_ATOMIC : GFP_KERNEL;
+
+        info = call_usermodehelper_setup(path, argv, envp, gfp_mask);
+
+        if (info == NULL)
+                return -ENOMEM;
+
+        call_usermodehelper_setfns(info, init, cleanup, data);
+
+        return call_usermodehelper_exec(info, wait);
+}
+EXPORT_SYMBOL(call_usermodehelper_fns);
 
 static int proc_cap_handler(struct ctl_table *table, int write,
                          void __user *buffer, size_t *lenp, loff_t *ppos)