* [PATCH net-next v1] net: fix sock compilation error under CONFIG_PREEMPT_RT
@ 2026-02-28 9:06 Jiayuan Chen
2026-02-28 10:43 ` Eric Dumazet
0 siblings, 1 reply; 3+ messages in thread
From: Jiayuan Chen @ 2026-02-28 9:06 UTC (permalink / raw)
To: netdev
Cc: jiayuan.chen, Jiayuan Chen, Eric Dumazet, Kuniyuki Iwashima,
Paolo Abeni, Willem de Bruijn, David S. Miller, Jakub Kicinski,
Simon Horman, Sebastian Andrzej Siewior, Clark Williams,
Steven Rostedt, Jason Xing, linux-kernel, linux-rt-devel
From: Jiayuan Chen <jiayuan.chen@shopee.com>
When CONFIG_PREEMPT_RT is enabled, __SPIN_LOCK_UNLOCKED() expands to a
brace-enclosed initializer rather than a compound literal, which cannot
be used in assignment expressions. This causes a build failure:
net/core/sock.c:3787:29: error: expected expression before '{' token
3787 | tmp.slock = __SPIN_LOCK_UNLOCKED(tmp.slock);
Use declaration-with-initializer instead of assignment, consistent with
how __SPIN_LOCK_UNLOCKED() is used elsewhere in the kernel (e.g.
DEFINE_SPINLOCK).
Fixes: 5151ec54f586 ("net: use try_cmpxchg() in lock_sock_nested()")
Signed-off-by: Jiayuan Chen <jiayuan.chen@shopee.com>
---
net/core/sock.c | 10 ++++------
1 file changed, 4 insertions(+), 6 deletions(-)
diff --git a/net/core/sock.c b/net/core/sock.c
index 9d841975a7a1..2461aba7b18a 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -3782,12 +3782,10 @@ void noinline lock_sock_nested(struct sock *sk, int subclass)
might_sleep();
#ifdef CONFIG_64BIT
if (sizeof(struct slock_owned) == sizeof(long)) {
- socket_lock_t tmp, old;
-
- tmp.slock = __SPIN_LOCK_UNLOCKED(tmp.slock);
- tmp.owned = 1;
- old.slock = __SPIN_LOCK_UNLOCKED(old.slock);
- old.owned = 0;
+ socket_lock_t tmp = { .slock = __SPIN_LOCK_UNLOCKED(tmp.slock),
+ .owned = 1 };
+ socket_lock_t old = { .slock = __SPIN_LOCK_UNLOCKED(old.slock),
+ .owned = 0 };
if (likely(try_cmpxchg(&sk->sk_lock.combined,
&old.combined, tmp.combined)))
return;
--
2.43.0
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH net-next v1] net: fix sock compilation error under CONFIG_PREEMPT_RT 2026-02-28 9:06 [PATCH net-next v1] net: fix sock compilation error under CONFIG_PREEMPT_RT Jiayuan Chen @ 2026-02-28 10:43 ` Eric Dumazet 2026-02-28 10:48 ` Jiayuan Chen 0 siblings, 1 reply; 3+ messages in thread From: Eric Dumazet @ 2026-02-28 10:43 UTC (permalink / raw) To: Jiayuan Chen Cc: netdev, Jiayuan Chen, Kuniyuki Iwashima, Paolo Abeni, Willem de Bruijn, David S. Miller, Jakub Kicinski, Simon Horman, Sebastian Andrzej Siewior, Clark Williams, Steven Rostedt, Jason Xing, linux-kernel, linux-rt-devel On Sat, Feb 28, 2026 at 10:07 AM Jiayuan Chen <jiayuan.chen@linux.dev> wrote: > > From: Jiayuan Chen <jiayuan.chen@shopee.com> > > When CONFIG_PREEMPT_RT is enabled, __SPIN_LOCK_UNLOCKED() expands to a > brace-enclosed initializer rather than a compound literal, which cannot > be used in assignment expressions. This causes a build failure: > > net/core/sock.c:3787:29: error: expected expression before '{' token > 3787 | tmp.slock = __SPIN_LOCK_UNLOCKED(tmp.slock); > > Use declaration-with-initializer instead of assignment, consistent with > how __SPIN_LOCK_UNLOCKED() is used elsewhere in the kernel (e.g. > DEFINE_SPINLOCK). > > Fixes: 5151ec54f586 ("net: use try_cmpxchg() in lock_sock_nested()") > Signed-off-by: Jiayuan Chen <jiayuan.chen@shopee.com> > --- > net/core/sock.c | 10 ++++------ > 1 file changed, 4 insertions(+), 6 deletions(-) > > diff --git a/net/core/sock.c b/net/core/sock.c > index 9d841975a7a1..2461aba7b18a 100644 > --- a/net/core/sock.c > +++ b/net/core/sock.c > @@ -3782,12 +3782,10 @@ void noinline lock_sock_nested(struct sock *sk, int subclass) > might_sleep(); > #ifdef CONFIG_64BIT > if (sizeof(struct slock_owned) == sizeof(long)) { > - socket_lock_t tmp, old; > - > - tmp.slock = __SPIN_LOCK_UNLOCKED(tmp.slock); > - tmp.owned = 1; > - old.slock = __SPIN_LOCK_UNLOCKED(old.slock); > - old.owned = 0; > + socket_lock_t tmp = { .slock = __SPIN_LOCK_UNLOCKED(tmp.slock), > + .owned = 1 }; > + socket_lock_t old = { .slock = __SPIN_LOCK_UNLOCKED(old.slock), > + .owned = 0 }; > if (likely(try_cmpxchg(&sk->sk_lock.combined, > &old.combined, tmp.combined))) > return; Thanks for your patch, could you please use a nicer formatting ? (And keep an empty line between variables and code) diff --git a/net/core/sock.c b/net/core/sock.c index 9d841975a7a14a12769450a8d937af96f7777070..fba4d5b8553c58f700bda3dbd82ce68ec74187da 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -3782,12 +3782,15 @@ void noinline lock_sock_nested(struct sock *sk, int subclass) might_sleep(); #ifdef CONFIG_64BIT if (sizeof(struct slock_owned) == sizeof(long)) { - socket_lock_t tmp, old; + socket_lock_t tmp = { + .slock = __SPIN_LOCK_UNLOCKED(tmp.slock), + .owned = 1, + }; + socket_lock_t old = { + .slock = __SPIN_LOCK_UNLOCKED(old.slock), + .owned = 0, + }; - tmp.slock = __SPIN_LOCK_UNLOCKED(tmp.slock); - tmp.owned = 1; - old.slock = __SPIN_LOCK_UNLOCKED(old.slock); - old.owned = 0; if (likely(try_cmpxchg(&sk->sk_lock.combined, &old.combined, tmp.combined))) return; ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH net-next v1] net: fix sock compilation error under CONFIG_PREEMPT_RT 2026-02-28 10:43 ` Eric Dumazet @ 2026-02-28 10:48 ` Jiayuan Chen 0 siblings, 0 replies; 3+ messages in thread From: Jiayuan Chen @ 2026-02-28 10:48 UTC (permalink / raw) To: Eric Dumazet Cc: netdev, Jiayuan Chen, Kuniyuki Iwashima, Paolo Abeni, Willem de Bruijn, David S. Miller, Jakub Kicinski, Simon Horman, Sebastian Andrzej Siewior, Clark Williams, Steven Rostedt, Jason Xing, linux-kernel, linux-rt-devel February 28, 2026 at 18:43, "Eric Dumazet" <edumazet@google.com mailto:edumazet@google.com?to=%22Eric%20Dumazet%22%20%3Cedumazet%40google.com%3E > wrote: > > On Sat, Feb 28, 2026 at 10:07 AM Jiayuan Chen <jiayuan.chen@linux.dev> wrote: > > > > > From: Jiayuan Chen <jiayuan.chen@shopee.com> > > > > When CONFIG_PREEMPT_RT is enabled, __SPIN_LOCK_UNLOCKED() expands to a > > brace-enclosed initializer rather than a compound literal, which cannot > > be used in assignment expressions. This causes a build failure: > > > > net/core/sock.c:3787:29: error: expected expression before '{' token > > 3787 | tmp.slock = __SPIN_LOCK_UNLOCKED(tmp.slock); > > > > Use declaration-with-initializer instead of assignment, consistent with > > how __SPIN_LOCK_UNLOCKED() is used elsewhere in the kernel (e.g. > > DEFINE_SPINLOCK). > > > > Fixes: 5151ec54f586 ("net: use try_cmpxchg() in lock_sock_nested()") > > Signed-off-by: Jiayuan Chen <jiayuan.chen@shopee.com> > > --- > > net/core/sock.c | 10 ++++------ > > 1 file changed, 4 insertions(+), 6 deletions(-) > > > > diff --git a/net/core/sock.c b/net/core/sock.c > > index 9d841975a7a1..2461aba7b18a 100644 > > --- a/net/core/sock.c > > +++ b/net/core/sock.c > > @@ -3782,12 +3782,10 @@ void noinline lock_sock_nested(struct sock *sk, int subclass) > > might_sleep(); > > #ifdef CONFIG_64BIT > > if (sizeof(struct slock_owned) == sizeof(long)) { > > - socket_lock_t tmp, old; > > - > > - tmp.slock = __SPIN_LOCK_UNLOCKED(tmp.slock); > > - tmp.owned = 1; > > - old.slock = __SPIN_LOCK_UNLOCKED(old.slock); > > - old.owned = 0; > > + socket_lock_t tmp = { .slock = __SPIN_LOCK_UNLOCKED(tmp.slock), > > + .owned = 1 }; > > + socket_lock_t old = { .slock = __SPIN_LOCK_UNLOCKED(old.slock), > > + .owned = 0 }; > > if (likely(try_cmpxchg(&sk->sk_lock.combined, > > &old.combined, tmp.combined))) > > return; > > > Thanks for your patch, could you please use a nicer formatting ? > (And keep an empty line between variables and code) Ack. I will send it later. > diff --git a/net/core/sock.c b/net/core/sock.c > index 9d841975a7a14a12769450a8d937af96f7777070..fba4d5b8553c58f700bda3dbd82ce68ec74187da > 100644 > --- a/net/core/sock.c > +++ b/net/core/sock.c > @@ -3782,12 +3782,15 @@ void noinline lock_sock_nested(struct sock > *sk, int subclass) > might_sleep(); > #ifdef CONFIG_64BIT > if (sizeof(struct slock_owned) == sizeof(long)) { > - socket_lock_t tmp, old; > + socket_lock_t tmp = { > + .slock = __SPIN_LOCK_UNLOCKED(tmp.slock), > + .owned = 1, > + }; > + socket_lock_t old = { > + .slock = __SPIN_LOCK_UNLOCKED(old.slock), > + .owned = 0, > + }; > > - tmp.slock = __SPIN_LOCK_UNLOCKED(tmp.slock); > - tmp.owned = 1; > - old.slock = __SPIN_LOCK_UNLOCKED(old.slock); > - old.owned = 0; > if (likely(try_cmpxchg(&sk->sk_lock.combined, > &old.combined, tmp.combined))) > return; > ^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2026-02-28 10:48 UTC | newest] Thread overview: 3+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2026-02-28 9:06 [PATCH net-next v1] net: fix sock compilation error under CONFIG_PREEMPT_RT Jiayuan Chen 2026-02-28 10:43 ` Eric Dumazet 2026-02-28 10:48 ` Jiayuan Chen
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