[PATCH bpf 2/3] bpf: bpf_sk_storage: Fix the missing uncharge in sk_omem_alloc

[Martin KaFai Lau <martin.lau@linux.dev>]

From: Martin KaFai Lau <martin.lau@kernel.org>

The commit c83597fa5dc6 ("bpf: Refactor some inode/task/sk storage functions for reuse"),
refactored the bpf_{sk,task,inode}_storage_free() into
bpf_local_storage_unlink_nolock() which then later renamed
to bpf_local_storage_destroy(). The commit accidentally passed the
"bool uncharge_mem = false" argument to bpf_selem_unlink_storage_nolock()
which then stopped the uncharge from happening to the sk->sk_omem_alloc.

This missing uncharge only happens when the sk is going away (during
__sk_destruct).

This patch fixes it by always passing "uncharge_mem = true". It is a
noop to the task/inode/cgroup storage because they do not have the
map_local_storage_(un)charge enabled in the map_ops. A followup patch will
be done in bpf-next to remove the uncharge_mem argument.

A selftest is added in the next patch.

Fixes: c83597fa5dc6 ("bpf: Refactor some inode/task/sk storage functions for reuse")
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
---
 kernel/bpf/bpf_local_storage.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/bpf/bpf_local_storage.c b/kernel/bpf/bpf_local_storage.c
index 37ad47d52dc5..146824cc9689 100644
--- a/kernel/bpf/bpf_local_storage.c
+++ b/kernel/bpf/bpf_local_storage.c
@@ -760,7 +760,7 @@ void bpf_local_storage_destroy(struct bpf_local_storage *local_storage)
 		 * of the loop will set the free_cgroup_storage to true.
 		 */
 		free_storage = bpf_selem_unlink_storage_nolock(
-			local_storage, selem, false, true);
+			local_storage, selem, true, true);
 	}
 	raw_spin_unlock_irqrestore(&local_storage->lock, flags);
 
-- 
2.34.1