Commit 7b984359 authored Jan 08, 2025 by Hou Tao Committed by Alexei Starovoitov Jan 08, 2025

bpf: Remove migrate_{disable|enable} from bpf_local_storage_free()



bpf_local_storage_free() has three callers:

1) bpf_local_storage_alloc()
Its caller must have disabled migration.

2) bpf_local_storage_destroy()
Its four callers (bpf_{cgrp|inode|task|sk}_storage_free()) have already
invoked migrate_disable() before invoking bpf_local_storage_destroy().

3) bpf_selem_unlink()
Its callers include: cgrp/inode/task/sk storage ->map_delete_elem
callbacks, bpf_{cgrp|inode|task|sk}_storage_delete() helpers and
bpf_local_storage_map_free(). All of these callers have already disabled
migration before invoking bpf_selem_unlink().

Therefore, it is OK to remove migrate_{disable|enable} pair from
bpf_local_storage_free().

Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20250108010728.207536-16-houtao@huaweicloud.com


Signed-off-by: Alexei Starovoitov <ast@kernel.org>

parent 4855a75e

kernel/bpf/bpf_local_storage.c

+2 −5

Original line number	Diff line number	Diff line
		@@ -172,18 +172,15 @@ static void bpf_local_storage_free(struct bpf_local_storage *local_storage,
		return;
		}

		if (smap) {
		migrate_disable();
		if (smap)
		bpf_mem_cache_free(&smap->storage_ma, local_storage);
		migrate_enable();
		} else {
		else
		/* smap could be NULL if the selem that triggered
		* this 'local_storage' creation had been long gone.
		* In this case, directly do call_rcu().
		*/
		call_rcu(&local_storage->rcu, bpf_local_storage_free_rcu);
		}
		}

		/* rcu tasks trace callback for bpf_ma == false */
		static void __bpf_selem_free_trace_rcu(struct rcu_head *rcu)