From 6ae9d5e99e1dd26babdd9502759fa25a3fd348ad Mon Sep 17 00:00:00 2001 From: Martin KaFai Lau Date: Wed, 22 Mar 2023 14:52:44 -0700 Subject: bpf: Use bpf_mem_cache_alloc/free for bpf_local_storage This patch uses bpf_mem_cache_alloc/free for allocating and freeing bpf_local_storage for task and cgroup storage. The changes are similar to the previous patch. A few things that worth to mention for bpf_local_storage: The local_storage is freed when the last selem is deleted. Before deleting a selem from local_storage, it needs to retrieve the local_storage->smap because the bpf_selem_unlink_storage_nolock() may have set it to NULL. Note that local_storage->smap may have already been NULL when the selem created this local_storage has been removed. In this case, call_rcu will be used to free the local_storage. Also, the bpf_ma (true or false) value is needed before calling bpf_local_storage_free(). The bpf_ma can either be obtained from the local_storage->smap (if available) or any of its selem's smap. A new helper check_storage_bpf_ma() is added to obtain bpf_ma for a deleting bpf_local_storage. When bpf_local_storage_alloc getting a reused memory, all fields are either in the correct values or will be initialized. 'cache[]' must already be all NULLs. 'list' must be empty. Others will be initialized. Cc: Namhyung Kim Signed-off-by: Martin KaFai Lau Link: https://lore.kernel.org/r/20230322215246.1675516-4-martin.lau@linux.dev Signed-off-by: Alexei Starovoitov --- include/linux/bpf_local_storage.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/bpf_local_storage.h b/include/linux/bpf_local_storage.h index 30efbcab2798..173ec7f43ed1 100644 --- a/include/linux/bpf_local_storage.h +++ b/include/linux/bpf_local_storage.h @@ -57,6 +57,7 @@ struct bpf_local_storage_map { u16 elem_size; u16 cache_idx; struct bpf_mem_alloc selem_ma; + struct bpf_mem_alloc storage_ma; bool bpf_ma; }; -- cgit v1.2.3