bpf: Use pcpu_alloc_size() in bpf_mem_free{_rcu}()

bpf: Use pcpu_alloc_size() in bpf_mem_free{_rcu}()

[ Upstream commit 3f2189e4f77b7a3e979d143dc4ff586488c7e8a5 ]

For bpf_global_percpu_ma, the pointer passed to bpf_mem_free_rcu() is
allocated by kmalloc() and its size is fixed (16-bytes on x86-64). So
no matter which cache allocates the dynamic per-cpu area, on x86-64
cache[2] will always be used to free the per-cpu area.

Fix the unbalance by checking whether the bpf memory allocator is
per-cpu or not and use pcpu_alloc_size() instead of ksize() to
find the correct cache for per-cpu free.

Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20231020133202.4043247-5-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Stable-dep-of: 7ac5c53e0073 ("bpf: Use c->unit_size to select target cache during free")
Signed-off-by: Sasha Levin <sashal@kernel.org>