[PATCH mptcp-next 0/3] mptcp: avoid data-races around the sysctls

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* [PATCH mptcp-next 0/3] mptcp: avoid data-races around the sysctls
@ 2026-08-17  1:24 Gang Yan
  2026-08-17  1:24 ` [PATCH mptcp-next 1/3] mptcp: sched: change scheduler sysctl atomically Gang Yan
                   ` (3 more replies)
  0 siblings, 4 replies; 5+ messages in thread
From: Gang Yan @ 2026-08-17  1:24 UTC (permalink / raw)
  To: mptcp; +Cc: Gang Yan

From: Gang Yan <yangang@kylinos.cn>

Hi,

As decribed in [1], this series is for addressing the KCSAN issues in
sysctls.

Following the tcp_congestion_control() model, patch 1 and 2 now store
pointers to the immutable ops and swap them atomically via xchg().

Patch 3 (from Matthieu) covers the remaining scalar sysctls with READ_ONCE().

[1] https://github.com/multipath-tcp/mptcp_net-next/issues/626

Gang Yan (2):
  mptcp: sched: change scheduler sysctl atomically
  mptcp: pm: change path_manager sysctl atomically

Matthieu Baerts (NGI0) (1):
  mptcp: use READ_ONCE() over sysctls

 net/mptcp/ctrl.c     | 116 ++++++++++++++++++++++++++++++-------------
 net/mptcp/pm.c       |   3 +-
 net/mptcp/protocol.c |   5 +-
 net/mptcp/protocol.h |   6 +--
 net/mptcp/sched.c    |   2 +-
 5 files changed, 91 insertions(+), 41 deletions(-)

-- 
2.43.0


^ permalink raw reply	[flat|nested] 5+ messages in thread

* [PATCH mptcp-next 1/3] mptcp: sched: change scheduler sysctl atomically
  2026-08-17  1:24 [PATCH mptcp-next 0/3] mptcp: avoid data-races around the sysctls Gang Yan
@ 2026-08-17  1:24 ` Gang Yan
  2026-08-17  1:24 ` [PATCH mptcp-next 2/3] mptcp: pm: change path_manager " Gang Yan
                   ` (2 subsequent siblings)
  3 siblings, 0 replies; 5+ messages in thread
From: Gang Yan @ 2026-08-17  1:24 UTC (permalink / raw)
  To: mptcp; +Cc: Gang Yan, Tao Cui

From: Gang Yan <yangang@kylinos.cn>

The per-netns scheduler name is stored as an inline char[] buffer and
updated via strscpy() from the sysctl handler. A concurrent reader (e.g.
mptcp_init_sock() resolving the default scheduler) can observe a
half-written name, which is also flagged by KCSAN. READ_ONCE() does not
help here as it cannot read a multi-byte string atomically.

Following the tcp_congestion_control() model, store a pointer to the
immutable struct mptcp_sched_ops instead of the name string:
  - mptcp_set_scheduler() now looks the ops up, takes a module reference,
    and atomically swaps the pernet pointer with xchg(), releasing the
    previous reference;
  - mptcp_get_scheduler() copies the ops name out under rcu_read_lock();
  - the default reference is taken in mptcp_pernet_set_defaults() and
    released in mptcp_net_exit(), mirroring tcp_sk_init()/tcp_sk_exit().

A pointer store is a single atomic word, so readers always observe a
consistent value.

Assisted-by: Claude:GLM5.2
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/626
Co-developed-by: Tao Cui <cuitao@kylinos.cn>
Signed-off-by: Tao Cui <cuitao@kylinos.cn>
Signed-off-by: Gang Yan <yangang@kylinos.cn>
---
 net/mptcp/ctrl.c     | 50 +++++++++++++++++++++++++++++++++-----------
 net/mptcp/protocol.c |  5 +++--
 net/mptcp/protocol.h |  3 ++-
 net/mptcp/sched.c    |  2 +-
 4 files changed, 44 insertions(+), 16 deletions(-)

diff --git a/net/mptcp/ctrl.c b/net/mptcp/ctrl.c
index 63c5747f0f63..85e9d3e996db 100644
--- a/net/mptcp/ctrl.c
+++ b/net/mptcp/ctrl.c
@@ -39,7 +39,7 @@ struct mptcp_pernet {
 	u8 allow_join_initial_addr_port;
 	u8 pm_type;
 	u8 add_addr_v6_port_drop_ts;
-	char scheduler[MPTCP_SCHED_NAME_MAX];
+	struct mptcp_sched_ops __rcu *scheduler;
 	char path_manager[MPTCP_PM_NAME_MAX];
 };
 
@@ -90,9 +90,14 @@ const char *mptcp_get_path_manager(const struct net *net)
 	return mptcp_get_pernet(net)->path_manager;
 }
 
-const char *mptcp_get_scheduler(const struct net *net)
+void mptcp_get_scheduler(const struct net *net, char *name)
 {
-	return mptcp_get_pernet(net)->scheduler;
+	struct mptcp_sched_ops *sched;
+
+	rcu_read_lock();
+	sched = rcu_dereference(mptcp_get_pernet(net)->scheduler);
+	strscpy(name, sched ? sched->name : "default", MPTCP_SCHED_NAME_MAX);
+	rcu_read_unlock();
 }
 
 unsigned int mptcp_add_addr_v6_port_drop_ts(const struct net *net)
@@ -112,23 +117,33 @@ static void mptcp_pernet_set_defaults(struct mptcp_pernet *pernet)
 	pernet->allow_join_initial_addr_port = 1;
 	pernet->stale_loss_cnt = 4;
 	pernet->pm_type = MPTCP_PM_TYPE_KERNEL;
-	strscpy(pernet->scheduler, "default", sizeof(pernet->scheduler));
+
+	if (bpf_try_module_get(&mptcp_sched_default, mptcp_sched_default.owner))
+		RCU_INIT_POINTER(pernet->scheduler, &mptcp_sched_default);
+
 	strscpy(pernet->path_manager, "kernel", sizeof(pernet->path_manager));
 	pernet->add_addr_v6_port_drop_ts = 1;
 }
 
 #ifdef CONFIG_SYSCTL
-static int mptcp_set_scheduler(char *scheduler, const char *name)
+static int mptcp_set_scheduler(struct mptcp_pernet *pernet, const char *name)
 {
-	struct mptcp_sched_ops *sched;
+	struct mptcp_sched_ops *sched, *prev;
 	int ret = 0;
 
 	rcu_read_lock();
 	sched = mptcp_sched_find(name);
-	if (sched)
-		strscpy(scheduler, name, MPTCP_SCHED_NAME_MAX);
-	else
+	if (sched) {
+		if (bpf_try_module_get(sched, sched->owner)) {
+			prev = xchg(&pernet->scheduler, sched);
+			if (prev)
+				bpf_module_put(prev, prev->owner);
+		} else {
+			ret = -EBUSY;
+		}
+	} else {
 		ret = -ENOENT;
+	}
 	rcu_read_unlock();
 
 	return ret;
@@ -137,7 +152,10 @@ static int mptcp_set_scheduler(char *scheduler, const char *name)
 static int proc_scheduler(const struct ctl_table *ctl, int write,
 			  void *buffer, size_t *lenp, loff_t *ppos)
 {
-	char (*scheduler)[MPTCP_SCHED_NAME_MAX] = ctl->data;
+	struct mptcp_pernet *pernet = container_of(ctl->data,
+						   struct mptcp_pernet,
+						   scheduler);
+	struct mptcp_sched_ops *sched;
 	char val[MPTCP_SCHED_NAME_MAX];
 	struct ctl_table tbl = {
 		.data = val,
@@ -145,11 +163,14 @@ static int proc_scheduler(const struct ctl_table *ctl, int write,
 	};
 	int ret;
 
-	strscpy(val, *scheduler, MPTCP_SCHED_NAME_MAX);
+	rcu_read_lock();
+	sched = rcu_dereference(pernet->scheduler);
+	strscpy(val, sched ? sched->name : "default", MPTCP_SCHED_NAME_MAX);
+	rcu_read_unlock();
 
 	ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
 	if (write && ret == 0)
-		ret = mptcp_set_scheduler(*scheduler, val);
+		ret = mptcp_set_scheduler(pernet, val);
 
 	return ret;
 }
@@ -573,8 +594,13 @@ static int __net_init mptcp_net_init(struct net *net)
 static void __net_exit mptcp_net_exit(struct net *net)
 {
 	struct mptcp_pernet *pernet = mptcp_get_pernet(net);
+	struct mptcp_sched_ops *sched;
 
 	mptcp_pernet_del_table(pernet);
+
+	sched = rcu_dereference_protected(pernet->scheduler, true);
+	if (sched)
+		bpf_module_put(sched, sched->owner);
 }
 
 static struct pernet_operations mptcp_pernet_ops = {
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index f879b1061f2d..9d84dd803802 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -3260,6 +3260,7 @@ static void mptcp_ca_reset(struct sock *sk)
 static int mptcp_init_sock(struct sock *sk)
 {
 	struct net *net = sock_net(sk);
+	char sched_name[MPTCP_SCHED_NAME_MAX];
 	int ret;
 
 	__mptcp_init_sock(sk);
@@ -3271,8 +3272,8 @@ static int mptcp_init_sock(struct sock *sk)
 		return -ENOMEM;
 
 	rcu_read_lock();
-	ret = mptcp_init_sched(mptcp_sk(sk),
-			       mptcp_sched_find(mptcp_get_scheduler(net)));
+	mptcp_get_scheduler(net, sched_name);
+	ret = mptcp_init_sched(mptcp_sk(sk), mptcp_sched_find(sched_name));
 	rcu_read_unlock();
 	if (ret)
 		return ret;
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index 7e168e450fb0..af79b3450ab7 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -803,7 +803,7 @@ unsigned int mptcp_stale_loss_cnt(const struct net *net);
 unsigned int mptcp_close_timeout(const struct sock *sk);
 int mptcp_get_pm_type(const struct net *net);
 const char *mptcp_get_path_manager(const struct net *net);
-const char *mptcp_get_scheduler(const struct net *net);
+void mptcp_get_scheduler(const struct net *net, char *name);
 unsigned int mptcp_add_addr_v6_port_drop_ts(const struct net *net);
 
 void mptcp_active_disable(struct sock *sk);
@@ -1155,6 +1155,7 @@ int mptcp_pm_remove_addr(struct mptcp_sock *msk, const struct mptcp_rm_list *rm_
 
 /* the default path manager, used in mptcp_pm_unregister */
 extern struct mptcp_pm_ops mptcp_pm_kernel;
+extern struct mptcp_sched_ops mptcp_sched_default;
 
 struct mptcp_pm_ops *mptcp_pm_find(const char *name);
 int mptcp_pm_register(struct mptcp_pm_ops *pm_ops);
diff --git a/net/mptcp/sched.c b/net/mptcp/sched.c
index 1e59072d478c..0d13ee46ffdf 100644
--- a/net/mptcp/sched.c
+++ b/net/mptcp/sched.c
@@ -40,7 +40,7 @@ static int mptcp_sched_default_get_retrans(struct mptcp_sock *msk)
 	return 0;
 }
 
-static struct mptcp_sched_ops mptcp_sched_default = {
+struct mptcp_sched_ops mptcp_sched_default = {
 	.get_send	= mptcp_sched_default_get_send,
 	.get_retrans	= mptcp_sched_default_get_retrans,
 	.name		= "default",
-- 
2.43.0


^ permalink raw reply related	[flat|nested] 5+ messages in thread

* [PATCH mptcp-next 2/3] mptcp: pm: change path_manager sysctl atomically
  2026-08-17  1:24 [PATCH mptcp-next 0/3] mptcp: avoid data-races around the sysctls Gang Yan
  2026-08-17  1:24 ` [PATCH mptcp-next 1/3] mptcp: sched: change scheduler sysctl atomically Gang Yan
@ 2026-08-17  1:24 ` Gang Yan
  2026-08-17  1:24 ` [PATCH mptcp-next 3/3] mptcp: use READ_ONCE() over sysctls Gang Yan
  2026-08-17  2:31 ` [PATCH mptcp-next 0/3] mptcp: avoid data-races around the sysctls MPTCP CI
  3 siblings, 0 replies; 5+ messages in thread
From: Gang Yan @ 2026-08-17  1:24 UTC (permalink / raw)
  To: mptcp; +Cc: Gang Yan, Tao Cui

From: Gang Yan <yangang@kylinos.cn>

The per-netns path manager name is stored as an inline char[] buffer and
updated via strscpy() from the sysctl handler; a concurrent reader can
observe a half-written name (and KCSAN flags the race), which READ_ONCE()
cannot fix for a multi-byte string.

Following the tcp_congestion_control() model (and the scheduler change in
the previous patch), store a pointer to the immutable struct mptcp_pm_ops
instead of the name string:
  - mptcp_set_path_manager() looks the ops up, takes a module reference,
    and atomically swaps the pernet pointer with xchg(), releasing the
    previous reference;
  - mptcp_get_path_manager() copies the ops name out under rcu_read_lock();
  - the pm_type field derived from the name is now written
    with WRITE_ONCE() to pair with its READ_ONCE() readers;
  - the default reference is taken in mptcp_pernet_set_defaults() and
    released in mptcp_net_exit().

Assisted-by: Claude:GLM5.2
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/626
Co-developed-by: Tao Cui <cuitao@kylinos.cn>
Signed-off-by: Tao Cui <cuitao@kylinos.cn>
Signed-off-by: Gang Yan <yangang@kylinos.cn>
---
 net/mptcp/ctrl.c     | 50 +++++++++++++++++++++++++++++++-------------
 net/mptcp/pm.c       |  3 ++-
 net/mptcp/protocol.h |  3 +--
 3 files changed, 39 insertions(+), 17 deletions(-)

diff --git a/net/mptcp/ctrl.c b/net/mptcp/ctrl.c
index 85e9d3e996db..fa28aecfb856 100644
--- a/net/mptcp/ctrl.c
+++ b/net/mptcp/ctrl.c
@@ -40,7 +40,7 @@ struct mptcp_pernet {
 	u8 pm_type;
 	u8 add_addr_v6_port_drop_ts;
 	struct mptcp_sched_ops __rcu *scheduler;
-	char path_manager[MPTCP_PM_NAME_MAX];
+	struct mptcp_pm_ops __rcu *path_manager;
 };
 
 static struct mptcp_pernet *mptcp_get_pernet(const struct net *net)
@@ -85,9 +85,14 @@ int mptcp_get_pm_type(const struct net *net)
 	return mptcp_get_pernet(net)->pm_type;
 }
 
-const char *mptcp_get_path_manager(const struct net *net)
+void mptcp_get_path_manager(const struct net *net, char *name)
 {
-	return mptcp_get_pernet(net)->path_manager;
+	struct mptcp_pm_ops *pm_ops;
+
+	rcu_read_lock();
+	pm_ops = rcu_dereference(mptcp_get_pernet(net)->path_manager);
+	strscpy(name, pm_ops ? pm_ops->name : "kernel", MPTCP_PM_NAME_MAX);
+	rcu_read_unlock();
 }
 
 void mptcp_get_scheduler(const struct net *net, char *name)
@@ -121,7 +126,9 @@ static void mptcp_pernet_set_defaults(struct mptcp_pernet *pernet)
 	if (bpf_try_module_get(&mptcp_sched_default, mptcp_sched_default.owner))
 		RCU_INIT_POINTER(pernet->scheduler, &mptcp_sched_default);
 
-	strscpy(pernet->path_manager, "kernel", sizeof(pernet->path_manager));
+	if (bpf_try_module_get(&mptcp_pm_kernel, mptcp_pm_kernel.owner))
+		RCU_INIT_POINTER(pernet->path_manager, &mptcp_pm_kernel);
+
 	pernet->add_addr_v6_port_drop_ts = 1;
 }
 
@@ -209,17 +216,24 @@ static int proc_blackhole_detect_timeout(const struct ctl_table *table,
 	return ret;
 }
 
-static int mptcp_set_path_manager(char *path_manager, const char *name)
+static int mptcp_set_path_manager(struct mptcp_pernet *pernet, const char *name)
 {
-	struct mptcp_pm_ops *pm_ops;
+	struct mptcp_pm_ops *pm_ops, *prev;
 	int ret = 0;
 
 	rcu_read_lock();
 	pm_ops = mptcp_pm_find(name);
-	if (pm_ops)
-		strscpy(path_manager, name, MPTCP_PM_NAME_MAX);
-	else
+	if (pm_ops) {
+		if (bpf_try_module_get(pm_ops, pm_ops->owner)) {
+			prev = xchg(&pernet->path_manager, pm_ops);
+			if (prev)
+				bpf_module_put(prev, prev->owner);
+		} else {
+			ret = -EBUSY;
+		}
+	} else {
 		ret = -ENOENT;
+	}
 	rcu_read_unlock();
 
 	return ret;
@@ -231,7 +245,7 @@ static int proc_path_manager(const struct ctl_table *ctl, int write,
 	struct mptcp_pernet *pernet = container_of(ctl->data,
 						   struct mptcp_pernet,
 						   path_manager);
-	char (*path_manager)[MPTCP_PM_NAME_MAX] = ctl->data;
+	struct mptcp_pm_ops *pm_ops;
 	char pm_name[MPTCP_PM_NAME_MAX];
 	const struct ctl_table tbl = {
 		.data = pm_name,
@@ -239,11 +253,14 @@ static int proc_path_manager(const struct ctl_table *ctl, int write,
 	};
 	int ret;
 
-	strscpy(pm_name, *path_manager, MPTCP_PM_NAME_MAX);
+	rcu_read_lock();
+	pm_ops = rcu_dereference(pernet->path_manager);
+	strscpy(pm_name, pm_ops ? pm_ops->name : "kernel", MPTCP_PM_NAME_MAX);
+	rcu_read_unlock();
 
 	ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
 	if (write && ret == 0) {
-		ret = mptcp_set_path_manager(*path_manager, pm_name);
+		ret = mptcp_set_path_manager(pernet, pm_name);
 		if (ret == 0) {
 			u8 pm_type = __MPTCP_PM_TYPE_NR;
 
@@ -251,7 +268,7 @@ static int proc_path_manager(const struct ctl_table *ctl, int write,
 				pm_type = MPTCP_PM_TYPE_KERNEL;
 			else if (strncmp(pm_name, "userspace", MPTCP_PM_NAME_MAX) == 0)
 				pm_type = MPTCP_PM_TYPE_USERSPACE;
-			pernet->pm_type = pm_type;
+			WRITE_ONCE(pernet->pm_type, pm_type);
 		}
 	}
 
@@ -275,7 +292,7 @@ static int proc_pm_type(const struct ctl_table *ctl, int write,
 			pm_name = "kernel";
 		else if (pm_type == MPTCP_PM_TYPE_USERSPACE)
 			pm_name = "userspace";
-		mptcp_set_path_manager(pernet->path_manager, pm_name);
+		mptcp_set_path_manager(pernet, pm_name);
 	}
 
 	return ret;
@@ -595,12 +612,17 @@ static void __net_exit mptcp_net_exit(struct net *net)
 {
 	struct mptcp_pernet *pernet = mptcp_get_pernet(net);
 	struct mptcp_sched_ops *sched;
+	struct mptcp_pm_ops *pm;
 
 	mptcp_pernet_del_table(pernet);
 
 	sched = rcu_dereference_protected(pernet->scheduler, true);
 	if (sched)
 		bpf_module_put(sched, sched->owner);
+
+	pm = rcu_dereference_protected(pernet->path_manager, true);
+	if (pm)
+		bpf_module_put(pm, pm->owner);
 }
 
 static struct pernet_operations mptcp_pernet_ops = {
diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index ba7c6f80a183..09f99bcd827c 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -1204,7 +1204,7 @@ void mptcp_pm_destroy(struct mptcp_sock *msk)
 void mptcp_pm_data_reset(struct mptcp_sock *msk)
 {
 	const struct net *net = sock_net((struct sock *)msk);
-	const char *pm_name = mptcp_get_path_manager(net);
+	char pm_name[MPTCP_PM_NAME_MAX];
 	u8 pm_type = mptcp_get_pm_type(net);
 	struct mptcp_pm_data *pm = &msk->pm;
 
@@ -1213,6 +1213,7 @@ void mptcp_pm_data_reset(struct mptcp_sock *msk)
 	pm->rm_list_rx.nr = 0;
 	WRITE_ONCE(pm->pm_type, pm_type);
 
+	mptcp_get_path_manager(net, pm_name);
 	rcu_read_lock();
 	mptcp_pm_ops_init(msk, pm_name);
 	rcu_read_unlock();
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index af79b3450ab7..99f447f2808f 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -802,7 +802,7 @@ int mptcp_allow_join_id0(const struct net *net);
 unsigned int mptcp_stale_loss_cnt(const struct net *net);
 unsigned int mptcp_close_timeout(const struct sock *sk);
 int mptcp_get_pm_type(const struct net *net);
-const char *mptcp_get_path_manager(const struct net *net);
+void mptcp_get_path_manager(const struct net *net, char *name);
 void mptcp_get_scheduler(const struct net *net, char *name);
 unsigned int mptcp_add_addr_v6_port_drop_ts(const struct net *net);
 
@@ -1153,7 +1153,6 @@ int mptcp_pm_announce_addr(struct mptcp_sock *msk,
 			   bool echo);
 int mptcp_pm_remove_addr(struct mptcp_sock *msk, const struct mptcp_rm_list *rm_list);
 
-/* the default path manager, used in mptcp_pm_unregister */
 extern struct mptcp_pm_ops mptcp_pm_kernel;
 extern struct mptcp_sched_ops mptcp_sched_default;
 
-- 
2.43.0


^ permalink raw reply related	[flat|nested] 5+ messages in thread

* [PATCH mptcp-next 3/3] mptcp: use READ_ONCE() over sysctls
  2026-08-17  1:24 [PATCH mptcp-next 0/3] mptcp: avoid data-races around the sysctls Gang Yan
  2026-08-17  1:24 ` [PATCH mptcp-next 1/3] mptcp: sched: change scheduler sysctl atomically Gang Yan
  2026-08-17  1:24 ` [PATCH mptcp-next 2/3] mptcp: pm: change path_manager " Gang Yan
@ 2026-08-17  1:24 ` Gang Yan
  2026-08-17  2:31 ` [PATCH mptcp-next 0/3] mptcp: avoid data-races around the sysctls MPTCP CI
  3 siblings, 0 replies; 5+ messages in thread
From: Gang Yan @ 2026-08-17  1:24 UTC (permalink / raw)
  To: mptcp; +Cc: Matthieu Baerts (NGI0), Eric Dumazet

From: "Matthieu Baerts (NGI0)" <matttbe@kernel.org>

To avoid KCSAN issues.

This patch is in theory for -net, and will need to be split in multiple
patches, with different Fixes tags. But I prefer to wait for Eric's
patches, as I noticed he already started to modify mptcp_is_enabled:

  https://lore.kernel.org/CANn89iLdwhhwLyO6zRjWMEY3t9g60ZE8ZhOVx33ucg_uRETbmQ@mail.gmail.com

Still, keeping this patch in this series, not to forget about it.

Reported-by: Eric Dumazet <edumazet@google.com>
Closes: https://lore.kernel.org/CANn89iL=os-60kDKqMDdyiXuPF5CG=eejS0vmthwpDGXz_Bp8A@mail.gmail.com
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
 net/mptcp/ctrl.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/net/mptcp/ctrl.c b/net/mptcp/ctrl.c
index fa28aecfb856..309bbb2a4eb0 100644
--- a/net/mptcp/ctrl.c
+++ b/net/mptcp/ctrl.c
@@ -50,39 +50,39 @@ static struct mptcp_pernet *mptcp_get_pernet(const struct net *net)
 
 int mptcp_is_enabled(const struct net *net)
 {
-	return mptcp_get_pernet(net)->mptcp_enabled;
+	return READ_ONCE(mptcp_get_pernet(net)->mptcp_enabled);
 }
 
 unsigned int mptcp_get_add_addr_timeout(const struct net *net)
 {
-	return mptcp_get_pernet(net)->add_addr_timeout;
+	return READ_ONCE(mptcp_get_pernet(net)->add_addr_timeout);
 }
 
 int mptcp_is_checksum_enabled(const struct net *net)
 {
-	return mptcp_get_pernet(net)->checksum_enabled;
+	return READ_ONCE(mptcp_get_pernet(net)->checksum_enabled);
 }
 
 int mptcp_allow_join_id0(const struct net *net)
 {
-	return mptcp_get_pernet(net)->allow_join_initial_addr_port;
+	return READ_ONCE(mptcp_get_pernet(net)->allow_join_initial_addr_port);
 }
 
 unsigned int mptcp_stale_loss_cnt(const struct net *net)
 {
-	return mptcp_get_pernet(net)->stale_loss_cnt;
+	return READ_ONCE(mptcp_get_pernet(net)->stale_loss_cnt);
 }
 
 unsigned int mptcp_close_timeout(const struct sock *sk)
 {
 	if (sock_flag(sk, SOCK_DEAD))
 		return TCP_TIMEWAIT_LEN;
-	return mptcp_get_pernet(sock_net(sk))->close_timeout;
+	return READ_ONCE(mptcp_get_pernet(sock_net(sk))->close_timeout);
 }
 
 int mptcp_get_pm_type(const struct net *net)
 {
-	return mptcp_get_pernet(net)->pm_type;
+	return READ_ONCE(mptcp_get_pernet(net)->pm_type);
 }
 
 void mptcp_get_path_manager(const struct net *net, char *name)
@@ -589,7 +589,7 @@ void mptcp_active_detect_blackhole(struct sock *ssk, bool expired)
 
 	net = sock_net(ssk);
 	timeouts = inet_csk(ssk)->icsk_retransmits;
-	to_max = mptcp_get_pernet(net)->syn_retrans_before_tcp_fallback;
+	to_max = READ_ONCE(mptcp_get_pernet(net)->syn_retrans_before_tcp_fallback);
 
 	if (timeouts == to_max || (timeouts < to_max && expired)) {
 		subflow->mpc_drop = 1;
-- 
2.43.0


^ permalink raw reply related	[flat|nested] 5+ messages in thread

* Re: [PATCH mptcp-next 0/3] mptcp: avoid data-races around the sysctls
  2026-08-17  1:24 [PATCH mptcp-next 0/3] mptcp: avoid data-races around the sysctls Gang Yan
                   ` (2 preceding siblings ...)
  2026-08-17  1:24 ` [PATCH mptcp-next 3/3] mptcp: use READ_ONCE() over sysctls Gang Yan
@ 2026-08-17  2:31 ` MPTCP CI
  3 siblings, 0 replies; 5+ messages in thread
From: MPTCP CI @ 2026-08-17  2:31 UTC (permalink / raw)
  To: Matthieu Baerts; +Cc: mptcp

Hi Matthieu,

Thank you for your modifications, that's great!

Our CI did some validations and here is its report:

- KVM Validation: normal (except selftest_mptcp_join): Success! ✅
- KVM Validation: normal (only selftest_mptcp_join): Success! ✅
- KVM Validation: debug (except selftest_mptcp_join): Success! ✅
- KVM Validation: debug (only selftest_mptcp_join): Success! ✅
- KVM Validation: btf-normal (only bpftest_all): Success! ✅
- KVM Validation: btf-debug (only bpftest_all): Success! ✅
- Task: https://github.com/multipath-tcp/mptcp_net-next/actions/runs/31986048689

Initiator: Patchew Applier
Commits: https://github.com/multipath-tcp/mptcp_net-next/commits/fa35ee6d384f
Patchwork: https://patchwork.kernel.org/project/mptcp/list/?series=1146872


If there are some issues, you can reproduce them using the same environment as
the one used by the CI thanks to a docker image, e.g.:

    $ cd [kernel source code]
    $ docker run -v "${PWD}:${PWD}:rw" -w "${PWD}" --privileged --rm -it \
        --pull always mptcp/mptcp-upstream-virtme-docker:latest \
        auto-normal

For more details:

    https://github.com/multipath-tcp/mptcp-upstream-virtme-docker


Please note that despite all the efforts that have been already done to have a
stable tests suite when executed on a public CI like here, it is possible some
reported issues are not due to your modifications. Still, do not hesitate to
help us improve that ;-)

Cheers,
MPTCP GH Action bot
Bot operated by Matthieu Baerts (NGI0 Core)

^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2026-08-17  2:31 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-08-17  1:24 [PATCH mptcp-next 0/3] mptcp: avoid data-races around the sysctls Gang Yan
2026-08-17  1:24 ` [PATCH mptcp-next 1/3] mptcp: sched: change scheduler sysctl atomically Gang Yan
2026-08-17  1:24 ` [PATCH mptcp-next 2/3] mptcp: pm: change path_manager " Gang Yan
2026-08-17  1:24 ` [PATCH mptcp-next 3/3] mptcp: use READ_ONCE() over sysctls Gang Yan
2026-08-17  2:31 ` [PATCH mptcp-next 0/3] mptcp: avoid data-races around the sysctls MPTCP CI

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