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([128.93.90.48]) by mail2-relais-roc.national.inria.fr with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Jun 2024 10:27:48 +0200 From: Julia Lawall To: "Jason A. Donenfeld" Cc: kernel-janitors@vger.kernel.org, "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , wireguard@lists.zx2c4.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, "Paul E . McKenney" , Vlastimil Babka Subject: [PATCH 01/14] wireguard: allowedips: replace call_rcu by kfree_rcu for simple kmem_cache_free callback Date: Sun, 9 Jun 2024 10:27:13 +0200 Message-Id: <20240609082726.32742-2-Julia.Lawall@inria.fr> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20240609082726.32742-1-Julia.Lawall@inria.fr> References: <20240609082726.32742-1-Julia.Lawall@inria.fr> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: kuba@kernel.org Since SLOB was removed, it is not necessary to use call_rcu when the callback only performs kmem_cache_free. Use kfree_rcu() directly. The changes were done using the following Coccinelle semantic patch. This semantic patch is designed to ignore cases where the callback function is used in another way. // @r@ expression e; local idexpression e2; identifier cb,f; position p; @@ ( call_rcu(...,e2) | call_rcu(&e->f,cb@p) ) @r1@ type T; identifier x,r.cb; @@ cb(...) { ( kmem_cache_free(...); | T x = ...; kmem_cache_free(...,x); | T x; x = ...; kmem_cache_free(...,x); ) } @s depends on r1@ position p != r.p; identifier r.cb; @@ cb@p @script:ocaml@ cb << r.cb; p << s.p; @@ Printf.eprintf "Other use of %s at %s:%d\n" cb (List.hd p).file (List.hd p).line @depends on r1 && !s@ expression e; identifier r.cb,f; position r.p; @@ - call_rcu(&e->f,cb@p) + kfree_rcu(e,f) @r1a depends on !s@ type T; identifier x,r.cb; @@ - cb(...) { ( - kmem_cache_free(...); | - T x = ...; - kmem_cache_free(...,x); | - T x; - x = ...; - kmem_cache_free(...,x); ) - } // Signed-off-by: Julia Lawall Reviewed-by: Paul E. McKenney Reviewed-by: Vlastimil Babka --- drivers/net/wireguard/allowedips.c | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-) diff --git a/drivers/net/wireguard/allowedips.c b/drivers/net/wireguard/allowedips.c index 0ba714ca5185..e4e1638fce1b 100644 --- a/drivers/net/wireguard/allowedips.c +++ b/drivers/net/wireguard/allowedips.c @@ -48,11 +48,6 @@ static void push_rcu(struct allowedips_node **stack, } } -static void node_free_rcu(struct rcu_head *rcu) -{ - kmem_cache_free(node_cache, container_of(rcu, struct allowedips_node, rcu)); -} - static void root_free_rcu(struct rcu_head *rcu) { struct allowedips_node *node, *stack[MAX_ALLOWEDIPS_DEPTH] = { @@ -330,13 +325,13 @@ void wg_allowedips_remove_by_peer(struct allowedips *table, child = rcu_dereference_protected( parent->bit[!(node->parent_bit_packed & 1)], lockdep_is_held(lock)); - call_rcu(&node->rcu, node_free_rcu); + kfree_rcu(node, rcu); if (!free_parent) continue; if (child) child->parent_bit_packed = parent->parent_bit_packed; *(struct allowedips_node **)(parent->parent_bit_packed & ~3UL) = child; - call_rcu(&parent->rcu, node_free_rcu); + kfree_rcu(parent, rcu); } }