[ANNOUNCE] v5.9-rt16v5.9-rt16-patches

Dear RT folks!

I'm pleased to announce the v5.9-rt16 patch set.

Changes since v5.9-rt15:

  - The rtmutex rework resulted in "unused variable" warnings if built
    without lockdep. Reported by Mike Galbraith.

  - The softirq rework led to a warning which could be triggered by the
    `ss' tool. Reported by Mike Galbraith.

  - The migrate-disable rework removed a data from a trace-event. Adding
    it bad resulted in a compile failure for !RT. Patch by Clark
    Williams.

Known issues
     - It has been pointed out that due to changes to the printk code the
       internal buffer representation changed. This is only an issue if tools
       like `crash' are used to extract the printk buffer from a kernel memory
       image.

The delta patch against v5.9-rt15 is appended below and can be found here:

     https://cdn.kernel.org/pub/linux/kernel/projects/rt/5.9/incr/patch-5.9-rt15-rt16.patch.xz

You can get this release via the git tree at:

    git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git v5.9-rt16

The RT patch against v5.9 can be found here:

    https://cdn.kernel.org/pub/linux/kernel/projects/rt/5.9/older/patch-5.9-rt16.patch.xz

The split quilt queue is available at:

    https://cdn.kernel.org/pub/linux/kernel/projects/rt/5.9/older/patches-5.9-rt16.tar.xz

Sebastian

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

6 files changed, 139 insertions, 19 deletions

diff --git a/patches/0016-locking-rtmutex-add-sleeping-lock-implementation.patch b/patches/0016-locking-rtmutex-add-sleeping-lock-implementation.patch
index 13320e483313..5147454efed8 100644
--- a/patches/0016-locking-rtmutex-add-sleeping-lock-implementation.patch
+++ b/patches/0016-locking-rtmutex-add-sleeping-lock-implementation.patch
@@ -225,10 +225,10 @@ Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
 +		rt_spin_lock_nested(lock, subclass);	\
 +	} while (0)
 +
-+# define spin_lock_nest_lock(lock, nest_lock)		\
++# define spin_lock_nest_lock(lock, subclass)		\
 +	do {                                                           \
-+		typecheck(struct lockdep_map *, &(nest_lock)->dep_map);	\
-+		rt_spin_lock_nest_lock(lock, &(nest_lock)->dep_map);	\
++		typecheck(struct lockdep_map *, &(subclass)->dep_map);	\
++		rt_spin_lock_nest_lock(lock, &(subclass)->dep_map);	\
 +	} while (0)
 +
 +# define spin_lock_irqsave_nested(lock, flags, subclass) \
@@ -238,15 +238,15 @@ Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
 +		rt_spin_lock_nested(lock, subclass);	 \
 +	} while (0)
 +#else
-+# define spin_lock_nested(lock, subclass)	spin_lock(lock)
-+# define spin_lock_nest_lock(lock, nest_lock)	spin_lock(lock)
-+# define spin_lock_bh_nested(lock, subclass)	spin_lock_bh(lock)
++# define spin_lock_nested(lock, subclass)	spin_lock(((void)(subclass), (lock)))
++# define spin_lock_nest_lock(lock, subclass)	spin_lock(((void)(subclass), (lock)))
++# define spin_lock_bh_nested(lock, subclass)	spin_lock_bh(((void)(subclass), (lock)))
 +
 +# define spin_lock_irqsave_nested(lock, flags, subclass) \
 +	do {						 \
 +		typecheck(unsigned long, flags);	 \
 +		flags = 0;				 \
-+		spin_lock(lock);			 \
++		spin_lock(((void)(subclass), (lock)));	 \
 +	} while (0)
 +#endif
 +
diff --git a/patches/ftrace-migrate-disable-tracing.patch b/patches/ftrace-migrate-disable-tracing.patch
index ca08691b6957..9e0c0153f295 100644
--- a/patches/ftrace-migrate-disable-tracing.patch
+++ b/patches/ftrace-migrate-disable-tracing.patch
@@ -5,10 +5,10 @@ Subject: trace: Add migrate-disabled counter to tracing output
 Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
 ---
  include/linux/trace_events.h |    1 +
- kernel/trace/trace.c         |   16 ++++++++++------
+ kernel/trace/trace.c         |   25 +++++++++++++++++++------
  kernel/trace/trace_events.c  |    1 +
  kernel/trace/trace_output.c  |    5 +++++
- 4 files changed, 17 insertions(+), 6 deletions(-)
+ 4 files changed, 26 insertions(+), 6 deletions(-)
 
 --- a/include/linux/trace_events.h
 +++ b/include/linux/trace_events.h
@@ -22,16 +22,32 @@ Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
  #define TRACE_EVENT_TYPE_MAX						\
 --- a/kernel/trace/trace.c
 +++ b/kernel/trace/trace.c
-@@ -2457,6 +2457,8 @@ tracing_generic_entry_update(struct trac
+@@ -2437,6 +2437,15 @@ enum print_line_t trace_handle_return(st
+ }
+ EXPORT_SYMBOL_GPL(trace_handle_return);
+ 
++static unsigned short migration_disable_value(struct task_struct *tsk)
++{
++#if defined(CONFIG_SMP) && defined(CONFIG_PREEMPT_RT)
++	return tsk ? tsk->migration_disabled : 0;
++#else
++	return 0;
++#endif
++}
++
+ void
+ tracing_generic_entry_update(struct trace_entry *entry, unsigned short type,
+ 			     unsigned long flags, int pc)
+@@ -2457,6 +2466,8 @@ tracing_generic_entry_update(struct trac
  		((pc & SOFTIRQ_OFFSET) ? TRACE_FLAG_SOFTIRQ : 0) |
  		(tif_need_resched() ? TRACE_FLAG_NEED_RESCHED : 0) |
  		(test_preempt_need_resched() ? TRACE_FLAG_PREEMPT_RESCHED : 0);
 +
-+	entry->migrate_disable = (tsk) ? tsk->migration_disabled & 0xFF : 0;
++	entry->migrate_disable = migration_disable_value(tsk);
  }
  EXPORT_SYMBOL_GPL(tracing_generic_entry_update);
  
-@@ -3789,9 +3791,10 @@ static void print_lat_help_header(struct
+@@ -3789,9 +3800,10 @@ static void print_lat_help_header(struct
  		    "#                  | / _----=> need-resched    \n"
  		    "#                  || / _---=> hardirq/softirq \n"
  		    "#                  ||| / _--=> preempt-depth   \n"
@@ -45,7 +61,7 @@ Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
  }
  
  static void print_event_info(struct array_buffer *buf, struct seq_file *m)
-@@ -3829,9 +3832,10 @@ static void print_func_help_header_irq(s
+@@ -3829,9 +3841,10 @@ static void print_func_help_header_irq(s
  	seq_printf(m, "#                            %.*s / _----=> need-resched\n", prec, space);
  	seq_printf(m, "#                            %.*s| / _---=> hardirq/softirq\n", prec, space);
  	seq_printf(m, "#                            %.*s|| / _--=> preempt-depth\n", prec, space);
diff --git a/patches/localversion.patch b/patches/localversion.patch
index 340816c8febc..0cccc7790a5d 100644
--- a/patches/localversion.patch
+++ b/patches/localversion.patch
@@ -10,4 +10,4 @@ Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
 --- /dev/null
 +++ b/localversion-rt
 @@ -0,0 +1 @@
-+-rt15
++-rt16
diff --git a/patches/preempt-lazy-support.patch b/patches/preempt-lazy-support.patch
index 8cee64c5571d..ba62c99f49c5 100644
--- a/patches/preempt-lazy-support.patch
+++ b/patches/preempt-lazy-support.patch
@@ -484,7 +484,7 @@ Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
  
 --- a/kernel/trace/trace.c
 +++ b/kernel/trace/trace.c
-@@ -2444,6 +2444,7 @@ tracing_generic_entry_update(struct trac
+@@ -2453,6 +2453,7 @@ tracing_generic_entry_update(struct trac
  	struct task_struct *tsk = current;
  
  	entry->preempt_count		= pc & 0xff;
@@ -492,7 +492,7 @@ Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
  	entry->pid			= (tsk) ? tsk->pid : 0;
  	entry->type			= type;
  	entry->flags =
-@@ -2455,7 +2456,8 @@ tracing_generic_entry_update(struct trac
+@@ -2464,7 +2465,8 @@ tracing_generic_entry_update(struct trac
  		((pc & NMI_MASK    ) ? TRACE_FLAG_NMI     : 0) |
  		((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) |
  		((pc & SOFTIRQ_OFFSET) ? TRACE_FLAG_SOFTIRQ : 0) |
@@ -501,8 +501,8 @@ Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
 +		(need_resched_lazy() ? TRACE_FLAG_NEED_RESCHED_LAZY : 0) |
  		(test_preempt_need_resched() ? TRACE_FLAG_PREEMPT_RESCHED : 0);
  
- 	entry->migrate_disable = (tsk) ? tsk->migration_disabled & 0xFF : 0;
-@@ -3786,15 +3788,17 @@ unsigned long trace_total_entries(struct
+ 	entry->migrate_disable = migration_disable_value(tsk);
+@@ -3795,15 +3797,17 @@ unsigned long trace_total_entries(struct
  
  static void print_lat_help_header(struct seq_file *m)
  {
@@ -529,7 +529,7 @@ Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
  }
  
  static void print_event_info(struct array_buffer *buf, struct seq_file *m)
-@@ -3828,14 +3832,16 @@ static void print_func_help_header_irq(s
+@@ -3837,14 +3841,16 @@ static void print_func_help_header_irq(s
  
  	print_event_info(buf, m);
  
diff --git a/patches/series b/patches/series
index 26a10ebbd376..1a9a9eb1e033 100644
--- a/patches/series
+++ b/patches/series
@@ -126,6 +126,7 @@ tpm-remove-tpm_dev_wq_lock.patch
 ############################################################
 shmem-Use-raw_spinlock_t-for-stat_lock.patch
 net--Move-lockdep-where-it-belongs.patch
+tcp-Remove-superfluous-BH-disable-around-listening_h.patch
 
 # SoftIRQ
 x86-fpu--Do-not-disable-BH-on-RT.patch
diff --git a/patches/tcp-Remove-superfluous-BH-disable-around-listening_h.patch b/patches/tcp-Remove-superfluous-BH-disable-around-listening_h.patch
new file mode 100644
index 000000000000..dc4f24c2d0d9
--- /dev/null
+++ b/patches/tcp-Remove-superfluous-BH-disable-around-listening_h.patch
@@ -0,0 +1,103 @@
+From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
+Date: Mon, 12 Oct 2020 17:33:54 +0200
+Subject: [PATCH] tcp: Remove superfluous BH-disable around listening_hash
+
+Commit
+   9652dc2eb9e40 ("tcp: relax listening_hash operations")
+
+removed the need to disable bottom half while acquiring
+listening_hash.lock. There are still two callers left which disable
+bottom half before the lock is acquired.
+
+Drop local_bh_disable() around __inet_hash() which acquires
+listening_hash->lock, invoke inet_ehash_nolisten() with disabled BH.
+inet_unhash() conditionally acquires listening_hash->lock.
+
+Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
+---
+ net/ipv4/inet_hashtables.c  | 19 ++++++++++++-------
+ net/ipv6/inet6_hashtables.c |  5 +----
+ 2 files changed, 13 insertions(+), 11 deletions(-)
+
+diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c
+index 239e54474b653..fcb105cbb5465 100644
+--- a/net/ipv4/inet_hashtables.c
++++ b/net/ipv4/inet_hashtables.c
+@@ -585,7 +585,9 @@ int __inet_hash(struct sock *sk, struct sock *osk)
+ 	int err = 0;
+ 
+ 	if (sk->sk_state != TCP_LISTEN) {
++		local_bh_disable();
+ 		inet_ehash_nolisten(sk, osk);
++		local_bh_enable();
+ 		return 0;
+ 	}
+ 	WARN_ON(!sk_unhashed(sk));
+@@ -617,11 +619,8 @@ int inet_hash(struct sock *sk)
+ {
+ 	int err = 0;
+ 
+-	if (sk->sk_state != TCP_CLOSE) {
+-		local_bh_disable();
++	if (sk->sk_state != TCP_CLOSE)
+ 		err = __inet_hash(sk, NULL);
+-		local_bh_enable();
+-	}
+ 
+ 	return err;
+ }
+@@ -632,17 +631,20 @@ void inet_unhash(struct sock *sk)
+ 	struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
+ 	struct inet_listen_hashbucket *ilb = NULL;
+ 	spinlock_t *lock;
++	bool state_listen;
+ 
+ 	if (sk_unhashed(sk))
+ 		return;
+ 
+ 	if (sk->sk_state == TCP_LISTEN) {
++		state_listen = true;
+ 		ilb = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)];
+-		lock = &ilb->lock;
++		spin_lock(&ilb->lock);
+ 	} else {
++		state_listen = false;
+ 		lock = inet_ehash_lockp(hashinfo, sk->sk_hash);
++		spin_lock_bh(lock);
+ 	}
+-	spin_lock_bh(lock);
+ 	if (sk_unhashed(sk))
+ 		goto unlock;
+ 
+@@ -655,7 +657,10 @@ void inet_unhash(struct sock *sk)
+ 	__sk_nulls_del_node_init_rcu(sk);
+ 	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
+ unlock:
+-	spin_unlock_bh(lock);
++	if (state_listen)
++		spin_unlock(&ilb->lock);
++	else
++		spin_unlock_bh(lock);
+ }
+ EXPORT_SYMBOL_GPL(inet_unhash);
+ 
+diff --git a/net/ipv6/inet6_hashtables.c b/net/ipv6/inet6_hashtables.c
+index 2d3add9e61162..50fd17cbf3ec7 100644
+--- a/net/ipv6/inet6_hashtables.c
++++ b/net/ipv6/inet6_hashtables.c
+@@ -335,11 +335,8 @@ int inet6_hash(struct sock *sk)
+ {
+ 	int err = 0;
+ 
+-	if (sk->sk_state != TCP_CLOSE) {
+-		local_bh_disable();
++	if (sk->sk_state != TCP_CLOSE)
+ 		err = __inet_hash(sk, NULL);
+-		local_bh_enable();
+-	}
+ 
+ 	return err;
+ }
+-- 
+2.28.0
+