Revert "mptcp: add get_subflow wrappers" - fix divide error in mptcp_…

…subflow_get_send This reverts commit 8ae8437. The wrapper mptcp_sched_get_send() will be added in the later patch "mptcp: use get_send wrapper", and the wrapper mptcp_sched_get_retrans() will be added in the later patch "mptcp: use get_retrans wrapper". Fix this divide error: ---- divide error: 0000 [#1] PREEMPT SMP KASAN NOPTI CPU: 0 PID: 14336 Comm: syz-executor.6 Not tainted 6.1.0-rc1-00215-g47aa7f23f440 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 RIP: 0010:div_u64_rem include/linux/math64.h:29 [inline] RIP: 0010:div_u64 include/linux/math64.h:128 [inline] RIP: 0010:mptcp_subflow_get_send+0xa87/0x1200 net/mptcp/protocol.c:1486 ---- Closes: #314 Reported-by: Mat Martineau <[email protected]> Signed-off-by: Geliang Tang <[email protected]> Link: https://lore.kernel.org/r/95f77f38e54f9564608e844f507701c04745475b.1666668425.git.geliang.tang@suse.com Signed-off-by: Matthieu Baerts <[email protected]>
multipath-tcp · Oct 31, 2022 · dce423f · dce423f
1 parent 6d193ac
commit dce423f
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Showing 3 changed files with 16 additions and 88 deletions.
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
@@ -1406,7 +1406,7 @@ bool mptcp_subflow_active(struct mptcp_subflow_context *subflow)
  * returns the subflow that will transmit the next DSS
  * additionally updates the rtx timeout
  */
-struct sock *mptcp_subflow_get_send(struct mptcp_sock *msk)
+static struct sock *mptcp_subflow_get_send(struct mptcp_sock *msk)
 {
 	struct subflow_send_info send_info[SSK_MODE_MAX];
 	struct mptcp_subflow_context *subflow;
@@ -1417,6 +1417,15 @@ struct sock *mptcp_subflow_get_send(struct mptcp_sock *msk)
 	u64 linger_time;
 	long tout = 0;
 
+	sock_owned_by_me(sk);
+
+	if (__mptcp_check_fallback(msk)) {
+		if (!msk->first)
+			return NULL;
+		return __tcp_can_send(msk->first) &&
+		       sk_stream_memory_free(msk->first) ? msk->first : NULL;
+	}
+
 	/* re-use last subflow, if the burst allow that */
 	if (msk->last_snd && msk->snd_burst > 0 &&
 	    sk_stream_memory_free(msk->last_snd) &&
@@ -2210,12 +2219,17 @@ static void mptcp_timeout_timer(struct timer_list *t)
  *
  * A backup subflow is returned only if that is the only kind available.
  */
-struct sock *mptcp_subflow_get_retrans(struct mptcp_sock *msk)
+static struct sock *mptcp_subflow_get_retrans(struct mptcp_sock *msk)
 {
 	struct sock *backup = NULL, *pick = NULL;
 	struct mptcp_subflow_context *subflow;
 	int min_stale_count = INT_MAX;
 
+	sock_owned_by_me((const struct sock *)msk);
+
+	if (__mptcp_check_fallback(msk))
+		return NULL;
+
 	mptcp_for_each_subflow(msk, subflow) {
 		struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
 

diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
@@ -641,10 +641,6 @@ int mptcp_init_sched(struct mptcp_sock *msk,
 void mptcp_release_sched(struct mptcp_sock *msk);
 void mptcp_subflow_set_scheduled(struct mptcp_subflow_context *subflow,
 				 bool scheduled);
-struct sock *mptcp_subflow_get_send(struct mptcp_sock *msk);
-struct sock *mptcp_subflow_get_retrans(struct mptcp_sock *msk);
-int mptcp_sched_get_send(struct mptcp_sock *msk);
-int mptcp_sched_get_retrans(struct mptcp_sock *msk);
 
 static inline bool __tcp_can_send(const struct sock *ssk)
 {

diff --git a/net/mptcp/sched.c b/net/mptcp/sched.c
@@ -93,85 +93,3 @@ void mptcp_subflow_set_scheduled(struct mptcp_subflow_context *subflow,
 {
 	WRITE_ONCE(subflow->scheduled, scheduled);
 }
-
-static int mptcp_sched_data_init(struct mptcp_sock *msk, bool reinject,
-				 struct mptcp_sched_data *data)
-{
-	struct mptcp_subflow_context *subflow;
-	int i = 0;
-
-	data->reinject = reinject;
-
-	mptcp_for_each_subflow(msk, subflow) {
-		if (i == MPTCP_SUBFLOWS_MAX) {
-			pr_warn_once("too many subflows");
-			break;
-		}
-		mptcp_subflow_set_scheduled(subflow, false);
-		data->contexts[i++] = subflow;
-	}
-
-	for (; i < MPTCP_SUBFLOWS_MAX; i++)
-		data->contexts[i] = NULL;
-
-	msk->snd_burst = 0;
-
-	return 0;
-}
-
-int mptcp_sched_get_send(struct mptcp_sock *msk)
-{
-	struct mptcp_sched_data data;
-	struct sock *ssk = NULL;
-
-	sock_owned_by_me((const struct sock *)msk);
-
-	/* the following check is moved out of mptcp_subflow_get_send */
-	if (__mptcp_check_fallback(msk)) {
-		if (msk->first &&
-		    __tcp_can_send(msk->first) &&
-		    sk_stream_memory_free(msk->first)) {
-			mptcp_subflow_set_scheduled(mptcp_subflow_ctx(msk->first), true);
-			return 0;
-		}
-		return -EINVAL;
-	}
-
-	if (!msk->sched) {
-		ssk = mptcp_subflow_get_send(msk);
-		if (!ssk)
-			return -EINVAL;
-		mptcp_subflow_set_scheduled(mptcp_subflow_ctx(ssk), true);
-		return 0;
-	}
-
-	mptcp_sched_data_init(msk, false, &data);
-	msk->sched->get_subflow(msk, &data);
-
-	return 0;
-}
-
-int mptcp_sched_get_retrans(struct mptcp_sock *msk)
-{
-	struct mptcp_sched_data data;
-	struct sock *ssk = NULL;
-
-	sock_owned_by_me((const struct sock *)msk);
-
-	/* the following check is moved out of mptcp_subflow_get_retrans */
-	if (__mptcp_check_fallback(msk))
-		return -EINVAL;
-
-	if (!msk->sched) {
-		ssk = mptcp_subflow_get_retrans(msk);
-		if (!ssk)
-			return -EINVAL;
-		mptcp_subflow_set_scheduled(mptcp_subflow_ctx(ssk), true);
-		return 0;
-	}
-
-	mptcp_sched_data_init(msk, true, &data);
-	msk->sched->get_subflow(msk, &data);
-
-	return 0;
-}