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authorPeter Zijlstra <peterz@infradead.org>2018-02-20 16:01:36 +0100
committerIngo Molnar <mingo@kernel.org>2018-02-21 08:56:40 +0100
commit88e77dc6a354095ddaaae715bc0d3b55702fa3db (patch)
tree203d07a95e41da5b4b415f7117c092c4eb8da20e /include
parent91ab883eb21325ad80f3473633f794c78ac87f51 (diff)
locking/mutex: Add comment to __mutex_owner() to deter usage
Attempt to deter usage, this is not a public interface. It is entirely possible to implement a conformant mutex without having this owner field (in fact, we used to have that). Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'include')
-rw-r--r--include/linux/mutex.h5
1 files changed, 5 insertions, 0 deletions
diff --git a/include/linux/mutex.h b/include/linux/mutex.h
index f25c13423bd4..cb3bbed4e633 100644
--- a/include/linux/mutex.h
+++ b/include/linux/mutex.h
@@ -66,6 +66,11 @@ struct mutex {
#endif
};
+/*
+ * Internal helper function; C doesn't allow us to hide it :/
+ *
+ * DO NOT USE (outside of mutex code).
+ */
static inline struct task_struct *__mutex_owner(struct mutex *lock)
{
return (struct task_struct *)(atomic_long_read(&lock->owner) & ~0x07);