[PATCH] refcount: restore kref_get and kref_put to non-GPL status

john.hubbard
2017-03-08T09:35:44Z

From: John Hubbard <jhubbard@nvidia.com>

Originally, kref_get and kref_put were available as
standard routines that even non-GPL device drivers
could use. However, as an unintended side effect of
the recent kref_*() upgrade[1], these calls are now
effectively GPL, because they get routed to the
new refcount_inc() and refcount_dec_and_test()
routines.

Make just those routines non-GPL, in order to restore
the original behavior--and to avoid forcing simple
users of krefs to re-implement atomic refcounting.

[1] commit 10383aea2f44 ("kref: Implement 'struct kref' using refcount_t")

Signed-off-by: John Hubbard <jhubbard@nvidia.com>
---
lib/refcount.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/refcount.c b/lib/refcount.c
index aa09ad3c30b0..6421a4930484 100644
--- a/lib/refcount.c
+++ b/lib/refcount.c
@@ -113,7 +113,7 @@ void refcount_inc(refcount_t *r)
{
WARN_ONCE(!refcount_inc_not_zero(r), "refcount_t: increment on 0; use-after-free.\n");
}
-EXPORT_SYMBOL_GPL(refcount_inc);
+EXPORT_SYMBOL(refcount_inc);

bool refcount_sub_and_test(unsigned int i, refcount_t *r)
{
@@ -152,7 +152,7 @@ bool refcount_dec_and_test(refcount_t *r)
{
return refcount_sub_and_test(1, r);
}
-EXPORT_SYMBOL_GPL(refcount_dec_and_test);
+EXPORT_SYMBOL(refcount_dec_and_test);

/*
* Similar to atomic_dec(), it will WARN on underflow and fail to decrement
--
2.12.0