From 59911be7e5ab7f1d02bceb956f05455c594cdc47 Mon Sep 17 00:00:00 2001
From: Greg Kroah-Hartman <gregkh@google.com>
Date: Tue, 7 Sep 2021 07:58:26 +0200
Subject: [PATCH] Revert "once: Fix panic when module unload"

This reverts commit 6815e21fe28ddfe8f55b4ca53031957dcd65843a which is
commit 1027b96ec9d34f9abab69bc1a4dc5b1ad8ab1349 upstream.

The function __do_once_done() added a new parameter to handle the
problem when unloading modules with that function in it.  Android does
not support module unloading so just revert this as it breaks the kabi.

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I4d5279c00c64f2f1836837c13c27cea5ed3ea073
---
 include/linux/once.h |  4 ++--
 lib/once.c           | 11 +++--------
 2 files changed, 5 insertions(+), 10 deletions(-)

diff --git a/include/linux/once.h b/include/linux/once.h
index ae6f4eb41cbe..9225ee6d96c7 100644
--- a/include/linux/once.h
+++ b/include/linux/once.h
@@ -7,7 +7,7 @@
 
 bool __do_once_start(bool *done, unsigned long *flags);
 void __do_once_done(bool *done, struct static_key_true *once_key,
-		    unsigned long *flags, struct module *mod);
+		    unsigned long *flags);
 
 /* Call a function exactly once. The idea of DO_ONCE() is to perform
  * a function call such as initialization of random seeds, etc, only
@@ -46,7 +46,7 @@ void __do_once_done(bool *done, struct static_key_true *once_key,
 			if (unlikely(___ret)) {				     \
 				func(__VA_ARGS__);			     \
 				__do_once_done(&___done, &___once_key,	     \
-					       &___flags, THIS_MODULE);	     \
+					       &___flags);		     \
 			}						     \
 		}							     \
 		___ret;							     \
diff --git a/lib/once.c b/lib/once.c
index 59149bf3bfb4..8b7d6235217e 100644
--- a/lib/once.c
+++ b/lib/once.c
@@ -3,12 +3,10 @@
 #include <linux/spinlock.h>
 #include <linux/once.h>
 #include <linux/random.h>
-#include <linux/module.h>
 
 struct once_work {
 	struct work_struct work;
 	struct static_key_true *key;
-	struct module *module;
 };
 
 static void once_deferred(struct work_struct *w)
@@ -18,11 +16,10 @@ static void once_deferred(struct work_struct *w)
 	work = container_of(w, struct once_work, work);
 	BUG_ON(!static_key_enabled(work->key));
 	static_branch_disable(work->key);
-	module_put(work->module);
 	kfree(work);
 }
 
-static void once_disable_jump(struct static_key_true *key, struct module *mod)
+static void once_disable_jump(struct static_key_true *key)
 {
 	struct once_work *w;
 
@@ -32,8 +29,6 @@ static void once_disable_jump(struct static_key_true *key, struct module *mod)
 
 	INIT_WORK(&w->work, once_deferred);
 	w->key = key;
-	w->module = mod;
-	__module_get(mod);
 	schedule_work(&w->work);
 }
 
@@ -58,11 +53,11 @@ bool __do_once_start(bool *done, unsigned long *flags)
 EXPORT_SYMBOL(__do_once_start);
 
 void __do_once_done(bool *done, struct static_key_true *once_key,
-		    unsigned long *flags, struct module *mod)
+		    unsigned long *flags)
 	__releases(once_lock)
 {
 	*done = true;
 	spin_unlock_irqrestore(&once_lock, *flags);
-	once_disable_jump(once_key, mod);
+	once_disable_jump(once_key);
 }
 EXPORT_SYMBOL(__do_once_done);