rcu: Export init_rcu_head() and destroy_rcu_head() to GPL modules

paulmck · martinkpetersen · commit 156baec39732 · 2017-12-07T19:51:49.000-05:00
Use of init_rcu_head() and destroy_rcu_head() from modules results in
the following build-time error with CONFIG_DEBUG_OBJECTS_RCU_HEAD=y:

	ERROR: "init_rcu_head" [drivers/scsi/scsi_mod.ko] undefined!
	ERROR: "destroy_rcu_head" [drivers/scsi/scsi_mod.ko] undefined!

This commit therefore adds EXPORT_SYMBOL_GPL() for each to allow them to
be used by GPL-licensed kernel modules.

Reported-by: Bart Van Assche &lt;Bart.VanAssche@wdc.com&gt;
Reported-by: Stephen Rothwell &lt;sfr@canb.auug.org.au&gt;
Signed-off-by: Paul E. McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
Signed-off-by: Martin K. Petersen &lt;martin.petersen@oracle.com&gt;
diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c
@@ -422,11 +422,13 @@ void init_rcu_head(struct rcu_head *head)
 {
 	debug_object_init(head, &rcuhead_debug_descr);
 }
+EXPORT_SYMBOL_GPL(init_rcu_head);
 
 void destroy_rcu_head(struct rcu_head *head)
 {
 	debug_object_free(head, &rcuhead_debug_descr);
 }
+EXPORT_SYMBOL_GPL(destroy_rcu_head);
 
 static bool rcuhead_is_static_object(void *addr)
 {

Original file line number	Diff line number	Diff line change
`@@ -422,11 +422,13 @@ void init_rcu_head(struct rcu_head *head)`
`422`	`422`	`{`
`423`	`423`	`debug_object_init(head, &rcuhead_debug_descr);`
`424`	`424`	`}`
	`425`	`+EXPORT_SYMBOL_GPL(init_rcu_head);`
`425`	`426`
`426`	`427`	`void destroy_rcu_head(struct rcu_head *head)`
`427`	`428`	`{`
`428`	`429`	`debug_object_free(head, &rcuhead_debug_descr);`
`429`	`430`	`}`
	`431`	`+EXPORT_SYMBOL_GPL(destroy_rcu_head);`
`430`	`432`
`431`	`433`	`static bool rcuhead_is_static_object(void *addr)`
`432`	`434`	`{`