bpf: Simplify code of destroy_mem_alloc() with kmemdup().

Use kmemdup() to simplify the code.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/bpf/20230706033447.54696-3-alexei.starovoitov@gmail.com

diff --git a/kernel/bpf/memalloc.c b/kernel/bpf/memalloc.c
index cc5b8adb4c83c5fa03bc70f05cd555baa092ff59..b0011217be6c953e5913cd8a8fad322c2fc537e4 100644 (file)
--- a/kernel/bpf/memalloc.c
+++ b/kernel/bpf/memalloc.c
@@ -499,7 +499,7 @@ static void destroy_mem_alloc(struct bpf_mem_alloc *ma, int rcu_in_progress)
                return;
        }
 
-       copy = kmalloc(sizeof(*ma), GFP_KERNEL);
+       copy = kmemdup(ma, sizeof(*ma), GFP_KERNEL);
        if (!copy) {
                /* Slow path with inline barrier-s */
                free_mem_alloc(ma);
@@ -507,10 +507,7 @@ static void destroy_mem_alloc(struct bpf_mem_alloc *ma, int rcu_in_progress)
        }
 
        /* Defer barriers into worker to let the rest of map memory to be freed */
-       copy->cache = ma->cache;
-       ma->cache = NULL;
-       copy->caches = ma->caches;
-       ma->caches = NULL;
+       memset(ma, 0, sizeof(*ma));
        INIT_WORK(&copy->work, free_mem_alloc_deferred);
        queue_work(system_unbound_wq, &copy->work);
 }