From 5e6300e7b3a4ab5b72a82079753868e91fbf9efc Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 31 Aug 2023 13:52:09 +0000 Subject: net: annotate data-races around sk->sk_forward_alloc Every time sk->sk_forward_alloc is read locklessly, add a READ_ONCE(). Add sk_forward_alloc_add() helper to centralize updates, to reduce number of WRITE_ONCE(). Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/mptcp/protocol.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'net/mptcp') diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 933b257eee02..625df3a36c46 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -1800,7 +1800,7 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) } /* data successfully copied into the write queue */ - sk->sk_forward_alloc -= total_ts; + sk_forward_alloc_add(sk, -total_ts); copied += psize; dfrag->data_len += psize; frag_truesize += psize; @@ -3257,7 +3257,7 @@ void mptcp_destroy_common(struct mptcp_sock *msk, unsigned int flags) /* move all the rx fwd alloc into the sk_mem_reclaim_final in * inet_sock_destruct() will dispose it */ - sk->sk_forward_alloc += msk->rmem_fwd_alloc; + sk_forward_alloc_add(sk, msk->rmem_fwd_alloc); msk->rmem_fwd_alloc = 0; mptcp_token_destroy(msk); mptcp_pm_free_anno_list(msk); @@ -3522,7 +3522,7 @@ static void mptcp_shutdown(struct sock *sk, int how) static int mptcp_forward_alloc_get(const struct sock *sk) { - return sk->sk_forward_alloc + mptcp_sk(sk)->rmem_fwd_alloc; + return READ_ONCE(sk->sk_forward_alloc) + mptcp_sk(sk)->rmem_fwd_alloc; } static int mptcp_ioctl_outq(const struct mptcp_sock *msk, u64 v) -- cgit v1.2.3 From 9531e4a83febc3fb47ac77e24cfb5ea97e50034d Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 31 Aug 2023 13:52:10 +0000 Subject: mptcp: annotate data-races around msk->rmem_fwd_alloc 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 Cc: Paolo Abeni Signed-off-by: David S. Miller --- net/mptcp/protocol.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) (limited to 'net/mptcp') diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 625df3a36c46..a7fc16f5175d 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -134,9 +134,15 @@ 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, @@ -177,7 +183,7 @@ 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); } @@ -186,7 +192,7 @@ 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 */ @@ -341,7 +347,7 @@ 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; } @@ -3258,7 +3264,7 @@ 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); @@ -3522,7 +3528,8 @@ 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) -- cgit v1.2.3