6.5-stable review patch. If anyone has any objections, please let me know.
------------------
From: Eric Dumazet <edumazet@xxxxxxxxxx>
[ 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@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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 e8927f2d47a3c..85f9dffde05d0 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -1053,6 +1053,12 @@ 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 */
@@ -1377,7 +1383,7 @@ 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)
@@ -1673,14 +1679,14 @@ 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 3109eb0cd512e..5edb17de6d1df 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1045,7 +1045,7 @@ 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));
@@ -3138,10 +3138,10 @@ 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);
@@ -3173,7 +3173,7 @@ 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 51d8638d4b4c6..9f9ca68c47026 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -3459,7 +3459,7 @@ 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 b3aa68ea29de2..4c847baf52d1c 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1443,9 +1443,9 @@ 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);
@@ -1556,7 +1556,7 @@ int __udp_enqueue_schedule_skb(struct sock *sk, struct sk_buff *skb)
goto uncharge_drop;
}
- 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 0efc52c640b59..996e031dff78a 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -1773,7 +1773,7 @@ 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;
@@ -3242,7 +3242,7 @@ 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);
@@ -3513,7 +3513,7 @@ 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)
--
2.40.1
