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authorEric Dumazet <edumazet@google.com>2023-08-31 16:52:10 +0300
committerDavid S. Miller <davem@davemloft.net>2023-09-01 09:27:33 +0300
commit9531e4a83febc3fb47ac77e24cfb5ea97e50034d (patch)
treee840aa2a06bb4c1a2a0dee027a6d256681a52020
parent5e6300e7b3a4ab5b72a82079753868e91fbf9efc (diff)
downloadlinux-9531e4a83febc3fb47ac77e24cfb5ea97e50034d.tar.xz
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 <edumazet@google.com> Cc: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/mptcp/protocol.c19
1 files changed, 13 insertions, 6 deletions
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)