From: David Laight There are two: min_t(int, xxx, mptcp_wnd_end(msk) - msk->snd_nxt); Both mptcp_wnd_end(msk) and msk->snd_nxt are u64, their difference (aka the window size) might be limited to 32 bits - but that isn't knowable from this code. So checks being added to min_t() detect the potential discard of significant bits. Provided the 'avail_size' and return of mptcp_check_allowed_size() are changed to an unsigned type (size_t matches the type the caller uses) both min_t() can be changed to min(). Signed-off-by: David Laight Reviewed-by: Matthieu Baerts (NGI0) [ wrapped too long lines when declaring mptcp_check_allowed_size() ] Signed-off-by: Matthieu Baerts (NGI0) --- net/mptcp/protocol.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 197ee169c0bc..e0b4745bbaa9 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -1160,8 +1160,9 @@ struct mptcp_sendmsg_info { bool data_lock_held; }; -static int mptcp_check_allowed_size(const struct mptcp_sock *msk, struct sock *ssk, - u64 data_seq, int avail_size) +static size_t mptcp_check_allowed_size(const struct mptcp_sock *msk, + struct sock *ssk, u64 data_seq, + size_t avail_size) { u64 window_end = mptcp_wnd_end(msk); u64 mptcp_snd_wnd; @@ -1170,7 +1171,7 @@ static int mptcp_check_allowed_size(const struct mptcp_sock *msk, struct sock *s return avail_size; mptcp_snd_wnd = window_end - data_seq; - avail_size = min_t(unsigned int, mptcp_snd_wnd, avail_size); + avail_size = min(mptcp_snd_wnd, avail_size); if (unlikely(tcp_sk(ssk)->snd_wnd < mptcp_snd_wnd)) { tcp_sk(ssk)->snd_wnd = min_t(u64, U32_MAX, mptcp_snd_wnd); @@ -1514,7 +1515,7 @@ struct sock *mptcp_subflow_get_send(struct mptcp_sock *msk) if (!ssk || !sk_stream_memory_free(ssk)) return NULL; - burst = min_t(int, MPTCP_SEND_BURST_SIZE, mptcp_wnd_end(msk) - msk->snd_nxt); + burst = min(MPTCP_SEND_BURST_SIZE, mptcp_wnd_end(msk) - msk->snd_nxt); wmem = READ_ONCE(ssk->sk_wmem_queued); if (!burst) return ssk; -- 2.51.0