6.5-stable review patch. If anyone has any objections, please let me know.
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From: Eric Dumazet edumazet@google.com
[ Upstream commit 9531e4a83febc3fb47ac77e24cfb5ea97e50034d ]
msk->rmem_fwd_alloc can be read locklessly.
Add mptcp_rmem_fwd_alloc_add(), similar to sk_forward_alloc_add(), and appropriate READ_ONCE()/WRITE_ONCE() annotations.
Fixes: 6511882cdd82 ("mptcp: allocate fwd memory separately on the rx and tx path") Signed-off-by: Eric Dumazet edumazet@google.com Cc: Paolo Abeni pabeni@redhat.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- net/mptcp/protocol.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-)
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 996e031dff78a..40258d9f8c799 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -136,9 +136,15 @@ static void mptcp_drop(struct sock *sk, struct sk_buff *skb) __kfree_skb(skb); }
+static void mptcp_rmem_fwd_alloc_add(struct sock *sk, int size) +{ + WRITE_ONCE(mptcp_sk(sk)->rmem_fwd_alloc, + mptcp_sk(sk)->rmem_fwd_alloc + size); +} + static void mptcp_rmem_charge(struct sock *sk, int size) { - mptcp_sk(sk)->rmem_fwd_alloc -= size; + mptcp_rmem_fwd_alloc_add(sk, -size); }
static bool mptcp_try_coalesce(struct sock *sk, struct sk_buff *to, @@ -179,7 +185,7 @@ static bool mptcp_ooo_try_coalesce(struct mptcp_sock *msk, struct sk_buff *to, static void __mptcp_rmem_reclaim(struct sock *sk, int amount) { amount >>= PAGE_SHIFT; - mptcp_sk(sk)->rmem_fwd_alloc -= amount << PAGE_SHIFT; + mptcp_rmem_charge(sk, amount << PAGE_SHIFT); __sk_mem_reduce_allocated(sk, amount); }
@@ -188,7 +194,7 @@ static void mptcp_rmem_uncharge(struct sock *sk, int size) struct mptcp_sock *msk = mptcp_sk(sk); int reclaimable;
- msk->rmem_fwd_alloc += size; + mptcp_rmem_fwd_alloc_add(sk, size); reclaimable = msk->rmem_fwd_alloc - sk_unused_reserved_mem(sk);
/* see sk_mem_uncharge() for the rationale behind the following schema */ @@ -343,7 +349,7 @@ static bool mptcp_rmem_schedule(struct sock *sk, struct sock *ssk, int size) if (!__sk_mem_raise_allocated(sk, size, amt, SK_MEM_RECV)) return false;
- msk->rmem_fwd_alloc += amount; + mptcp_rmem_fwd_alloc_add(sk, amount); return true; }
@@ -3243,7 +3249,7 @@ void mptcp_destroy_common(struct mptcp_sock *msk, unsigned int flags) * inet_sock_destruct() will dispose it */ sk_forward_alloc_add(sk, msk->rmem_fwd_alloc); - msk->rmem_fwd_alloc = 0; + WRITE_ONCE(msk->rmem_fwd_alloc, 0); mptcp_token_destroy(msk); mptcp_pm_free_anno_list(msk); mptcp_free_local_addr_list(msk); @@ -3513,7 +3519,8 @@ static void mptcp_shutdown(struct sock *sk, int how)
static int mptcp_forward_alloc_get(const struct sock *sk) { - return READ_ONCE(sk->sk_forward_alloc) + mptcp_sk(sk)->rmem_fwd_alloc; + return READ_ONCE(sk->sk_forward_alloc) + + READ_ONCE(mptcp_sk(sk)->rmem_fwd_alloc); }
static int mptcp_ioctl_outq(const struct mptcp_sock *msk, u64 v)