5.15-stable review patch. If anyone has any objections, please let me know.
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From: Uladzislau Rezki (Sony) urezki@gmail.com
[ Upstream commit 608723c41cd951fb32ade2f8371e61c270816175 ]
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 Stable-dep-of: 511e64e13d8c ("can: gw: fix RCU/BH usage in cgw_create_job()") Signed-off-by: Sasha Levin sashal@kernel.org --- include/linux/rcupdate.h | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index d908af5917339..978769e545b5f 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -979,6 +979,9 @@ 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 { \