6.1-stable review patch. If anyone has any objections, please let me know.
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From: Eric Dumazet edumazet@google.com
[ Upstream commit 5e6300e7b3a4ab5b72a82079753868e91fbf9efc ]
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 edumazet@google.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- include/net/sock.h | 12 +++++++++--- net/core/sock.c | 8 ++++---- net/ipv4/tcp_output.c | 2 +- net/ipv4/udp.c | 6 +++--- net/mptcp/protocol.c | 6 +++--- 5 files changed, 20 insertions(+), 14 deletions(-)
diff --git a/include/net/sock.h b/include/net/sock.h index d1f936ed97556..fe695e8bfe289 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -1049,6 +1049,12 @@ static inline void sk_wmem_queued_add(struct sock *sk, int val) WRITE_ONCE(sk->sk_wmem_queued, sk->sk_wmem_queued + val); }
+static inline void sk_forward_alloc_add(struct sock *sk, int val) +{ + /* Paired with lockless reads of sk->sk_forward_alloc */ + WRITE_ONCE(sk->sk_forward_alloc, sk->sk_forward_alloc + val); +} + void sk_stream_write_space(struct sock *sk);
/* OOB backlog add */ @@ -1401,7 +1407,7 @@ static inline int sk_forward_alloc_get(const struct sock *sk) if (sk->sk_prot->forward_alloc_get) return sk->sk_prot->forward_alloc_get(sk); #endif - return sk->sk_forward_alloc; + return READ_ONCE(sk->sk_forward_alloc); }
static inline bool __sk_stream_memory_free(const struct sock *sk, int wake) @@ -1697,14 +1703,14 @@ static inline void sk_mem_charge(struct sock *sk, int size) { if (!sk_has_account(sk)) return; - sk->sk_forward_alloc -= size; + sk_forward_alloc_add(sk, -size); }
static inline void sk_mem_uncharge(struct sock *sk, int size) { if (!sk_has_account(sk)) return; - sk->sk_forward_alloc += size; + sk_forward_alloc_add(sk, size); sk_mem_reclaim(sk); }
diff --git a/net/core/sock.c b/net/core/sock.c index 6ff58fa5f41ed..aa628c6314f64 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -1034,7 +1034,7 @@ static int sock_reserve_memory(struct sock *sk, int bytes) mem_cgroup_uncharge_skmem(sk->sk_memcg, pages); return -ENOMEM; } - sk->sk_forward_alloc += pages << PAGE_SHIFT; + sk_forward_alloc_add(sk, pages << PAGE_SHIFT);
WRITE_ONCE(sk->sk_reserved_mem, sk->sk_reserved_mem + (pages << PAGE_SHIFT)); @@ -3082,10 +3082,10 @@ int __sk_mem_schedule(struct sock *sk, int size, int kind) { int ret, amt = sk_mem_pages(size);
- sk->sk_forward_alloc += amt << PAGE_SHIFT; + sk_forward_alloc_add(sk, amt << PAGE_SHIFT); ret = __sk_mem_raise_allocated(sk, size, amt, kind); if (!ret) - sk->sk_forward_alloc -= amt << PAGE_SHIFT; + sk_forward_alloc_add(sk, -(amt << PAGE_SHIFT)); return ret; } EXPORT_SYMBOL(__sk_mem_schedule); @@ -3117,7 +3117,7 @@ void __sk_mem_reduce_allocated(struct sock *sk, int amount) void __sk_mem_reclaim(struct sock *sk, int amount) { amount >>= PAGE_SHIFT; - sk->sk_forward_alloc -= amount << PAGE_SHIFT; + sk_forward_alloc_add(sk, -(amount << PAGE_SHIFT)); __sk_mem_reduce_allocated(sk, amount); } EXPORT_SYMBOL(__sk_mem_reclaim); diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 26bd039f9296f..dc3166e56169f 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -3380,7 +3380,7 @@ void sk_forced_mem_schedule(struct sock *sk, int size) if (delta <= 0) return; amt = sk_mem_pages(delta); - sk->sk_forward_alloc += amt << PAGE_SHIFT; + sk_forward_alloc_add(sk, amt << PAGE_SHIFT); sk_memory_allocated_add(sk, amt);
if (mem_cgroup_sockets_enabled && sk->sk_memcg) diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index 42c1f7d9a980a..b2aa7777521f6 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -1474,9 +1474,9 @@ static void udp_rmem_release(struct sock *sk, int size, int partial, spin_lock(&sk_queue->lock);
- sk->sk_forward_alloc += size; + sk_forward_alloc_add(sk, size); amt = (sk->sk_forward_alloc - partial) & ~(PAGE_SIZE - 1); - sk->sk_forward_alloc -= amt; + sk_forward_alloc_add(sk, -amt);
if (amt) __sk_mem_reduce_allocated(sk, amt >> PAGE_SHIFT); @@ -1582,7 +1582,7 @@ int __udp_enqueue_schedule_skb(struct sock *sk, struct sk_buff *skb) sk->sk_forward_alloc += delta; }
- sk->sk_forward_alloc -= size; + sk_forward_alloc_add(sk, -size);
/* no need to setup a destructor, we will explicitly release the * forward allocated memory on dequeue diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 61fefa1a82db2..573db9c2bc1cd 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -1802,7 +1802,7 @@ 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; @@ -3278,7 +3278,7 @@ 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); @@ -3562,7 +3562,7 @@ 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)