rcu/kvfree: Add kvfree_rcu_mightsleep() and kfree_rcu_mightsleep()

The kvfree_rcu() and kfree_rcu() APIs are hazardous in that if you forget
the second argument, it works, but might sleep.  This sleeping can be a
correctness bug from atomic contexts, and even in non-atomic contexts
it might introduce unacceptable latencies.  This commit therefore adds
kvfree_rcu_mightsleep() and kfree_rcu_mightsleep(), which will replace
the single-argument kvfree_rcu() and kfree_rcu(), respectively.

This commit enables a series of commits that switch from single-argument
kvfree_rcu() and kfree_rcu() to their _mightsleep() counterparts.  Once
all of these commits land, the single-argument versions will be removed.

Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
This commit is contained in:
Uladzislau Rezki (Sony) 2023-02-01 16:08:07 +01:00 committed by Paul E. McKenney
parent 2ca836b1da
commit 608723c41c

View file

@ -1004,6 +1004,9 @@ static inline notrace void rcu_read_unlock_sched_notrace(void)
#define kvfree_rcu(...) KVFREE_GET_MACRO(__VA_ARGS__, \
kvfree_rcu_arg_2, kvfree_rcu_arg_1)(__VA_ARGS__)
#define kvfree_rcu_mightsleep(ptr) kvfree_rcu_arg_1(ptr)
#define kfree_rcu_mightsleep(ptr) kvfree_rcu_mightsleep(ptr)
#define KVFREE_GET_MACRO(_1, _2, NAME, ...) NAME
#define kvfree_rcu_arg_2(ptr, rhf) \
do { \