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From: Julia Lawall <Julia.Lawall@inria.fr>
To: linux-block@vger.kernel.org
Cc: kernel-janitors@vger.kernel.org,
	bridge@lists.linux.dev,
	linux-trace-kernel@vger.kernel.org,
	Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
	kvm@vger.kernel.org,
	linuxppc-dev@lists.ozlabs.org,
	"Naveen N. Rao" <naveen.n.rao@linux.ibm.com>,
	Christophe Leroy <christophe.leroy@csgroup.eu>,
	Nicholas Piggin <npiggin@gmail.com>,
	netdev@vger.kernel.org,
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	linux-kernel@vger.kernel.org,
	ecryptfs@vger.kernel.org,
	Neil Brown <neilb@suse.de>,
	Olga Kornievskaia <kolga@netapp.com>,
	Dai Ngo <Dai.Ngo@oracle.com>,
	Tom Talpey <tom@talpey.com>,
	linux-nfs@vger.kernel.org,
	linux-can@vger.kernel.org,
	Lai Jiangshan <jiangshanlai@gmail.com>,
	netfilter-devel@vger.kernel.org,
	coreteam@netfilter.org,
	"Paul E . McKenney" <paulmck@kernel.org>,
	Vlastimil Babka <vbabka@suse.cz>
Subject: [PATCH 00/14] replace call_rcu by kfree_rcu for simple kmem_cache_free callback
Date: Sun,  9 Jun 2024 10:27:12 +0200
Message-Id: <20240609082726.32742-1-Julia.Lawall@inria.fr>
Precedence: bulk
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit

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.

// <smpl>
@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);
)
- }
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>

---

 arch/powerpc/kvm/book3s_mmu_hpte.c  |    8 +-------
 block/blk-ioc.c                     |    9 +--------
 drivers/net/wireguard/allowedips.c  |    9 ++-------
 fs/ecryptfs/dentry.c                |    8 +-------
 fs/nfsd/nfs4state.c                 |    9 +--------
 fs/tracefs/inode.c                  |   10 +---------
 kernel/time/posix-timers.c          |    9 +--------
 kernel/workqueue.c                  |    8 +-------
 net/bridge/br_fdb.c                 |    9 +--------
 net/can/gw.c                        |   13 +++----------
 net/ipv4/fib_trie.c                 |    8 +-------
 net/ipv4/inetpeer.c                 |    9 ++-------
 net/ipv6/ip6_fib.c                  |    9 +--------
 net/ipv6/xfrm6_tunnel.c             |    8 +-------
 net/kcm/kcmsock.c                   |   10 +---------
 net/netfilter/nf_conncount.c        |   10 +---------
 net/netfilter/nf_conntrack_expect.c |   10 +---------
 net/netfilter/xt_hashlimit.c        |    9 +--------
 18 files changed, 22 insertions(+), 143 deletions(-)