Merging debian version 6.10.3-1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 136 insertions, 0 deletions

diff --git a/debian/patches-rt/0039-printk-nbcon-Show-replay-message-on-takeover.patch b/debian/patches-rt/0039-printk-nbcon-Show-replay-message-on-takeover.patch
new file mode 100644
index 0000000000..28fc95581c
--- /dev/null
+++ b/debian/patches-rt/0039-printk-nbcon-Show-replay-message-on-takeover.patch
@@ -0,0 +1,136 @@
+From: John Ogness <john.ogness@linutronix.de>
+Date: Mon, 25 Mar 2024 21:00:40 +0000
+Subject: [PATCH 39/48] printk: nbcon: Show replay message on takeover
+Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/6.10/older/patches-6.10.2-rt14.tar.xz
+
+An emergency or panic context can takeover console ownership
+while the current owner was printing a printk message. The
+atomic printer will re-print the message that the previous
+owner was printing. However, this can look confusing to the
+user and may even seem as though a message was lost.
+
+  [3430014.1
+  [3430014.181123] usb 1-2: Product: USB Audio
+
+Add a new field @nbcon_prev_seq to struct console to track
+the sequence number to print that was assigned to the previous
+console owner. If this matches the sequence number to print
+that the current owner is assigned, then a takeover must have
+occurred. In this case, print an additional message to inform
+the user that the previous message is being printed again.
+
+  [3430014.1
+  ** replaying previous printk message **
+  [3430014.181123] usb 1-2: Product: USB Audio
+
+Signed-off-by: John Ogness <john.ogness@linutronix.de>
+Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
+---
+ include/linux/console.h  |    3 +++
+ kernel/printk/internal.h |    1 +
+ kernel/printk/nbcon.c    |   24 ++++++++++++++++++++++++
+ kernel/printk/printk.c   |   19 +++++++++++++++++++
+ 4 files changed, 47 insertions(+)
+
+--- a/include/linux/console.h
++++ b/include/linux/console.h
+@@ -325,6 +325,7 @@ struct nbcon_write_context {
+  * @nbcon_state:	State for nbcon consoles
+  * @nbcon_seq:		Sequence number of the next record for nbcon to print
+  * @nbcon_device_ctxt:	Context available for non-printing operations
++ * @nbcon_prev_seq:	Seq num the previous nbcon owner was assigned to print
+  * @pbufs:		Pointer to nbcon private buffer
+  * @kthread:		Printer kthread for this console
+  * @rcuwait:		RCU-safe wait object for @kthread waking
+@@ -445,6 +446,8 @@ struct console {
+ 	atomic_t		__private nbcon_state;
+ 	atomic_long_t		__private nbcon_seq;
+ 	struct nbcon_context	__private nbcon_device_ctxt;
++	atomic_long_t           __private nbcon_prev_seq;
++
+ 	struct printk_buffers	*pbufs;
+ 	struct task_struct	*kthread;
+ 	struct rcuwait		rcuwait;
+--- a/kernel/printk/internal.h
++++ b/kernel/printk/internal.h
+@@ -233,4 +233,5 @@ bool printk_get_next_message(struct prin
+ 
+ #ifdef CONFIG_PRINTK
+ void console_prepend_dropped(struct printk_message *pmsg, unsigned long dropped);
++void console_prepend_replay(struct printk_message *pmsg);
+ #endif
+--- a/kernel/printk/nbcon.c
++++ b/kernel/printk/nbcon.c
+@@ -866,6 +866,7 @@ static bool nbcon_emit_next_record(struc
+ 	unsigned long con_dropped;
+ 	struct nbcon_state cur;
+ 	unsigned long dropped;
++	unsigned long ulseq;
+ 
+ 	/*
+ 	 * The printk buffers are filled within an unsafe section. This
+@@ -891,6 +892,28 @@ static bool nbcon_emit_next_record(struc
+ 	if (dropped && !is_extended)
+ 		console_prepend_dropped(&pmsg, dropped);
+ 
++	/*
++	 * If the previous owner was assigned the same record, this context
++	 * has taken over ownership and is replaying the record. Prepend a
++	 * message to let the user know the record is replayed.
++	 */
++	ulseq = atomic_long_read(&ACCESS_PRIVATE(con, nbcon_prev_seq));
++	if (__ulseq_to_u64seq(prb, ulseq) == pmsg.seq) {
++		console_prepend_replay(&pmsg);
++	} else {
++		/*
++		 * Ensure this context is still the owner before trying to
++		 * update @nbcon_prev_seq. Otherwise the value in @ulseq may
++		 * not be from the previous owner.
++		 */
++		nbcon_state_read(con, &cur);
++		if (!nbcon_context_can_proceed(ctxt, &cur))
++			return false;
++
++		atomic_long_try_cmpxchg(&ACCESS_PRIVATE(con, nbcon_prev_seq), &ulseq,
++					__u64seq_to_ulseq(pmsg.seq));
++	}
++
+ 	if (!nbcon_context_exit_unsafe(ctxt))
+ 		return false;
+ 
+@@ -1642,6 +1665,7 @@ void nbcon_init(struct console *con, u64
+ 	rcuwait_init(&con->rcuwait);
+ 	init_irq_work(&con->irq_work, nbcon_irq_work);
+ 	nbcon_seq_force(con, init_seq);
++	atomic_long_set(&ACCESS_PRIVATE(con, nbcon_prev_seq), -1UL);
+ 	nbcon_state_set(con, &state);
+ 	nbcon_kthread_create(con);
+ }
+--- a/kernel/printk/printk.c
++++ b/kernel/printk/printk.c
+@@ -2868,6 +2868,25 @@ void console_prepend_dropped(struct prin
+ }
+ 
+ /*
++ * Prepend the message in @pmsg->pbufs->outbuf with a "replay message".
++ * @pmsg->outbuf_len is updated appropriately.
++ *
++ * @pmsg is the printk message to prepend.
++ */
++void console_prepend_replay(struct printk_message *pmsg)
++{
++	struct printk_buffers *pbufs = pmsg->pbufs;
++	const size_t scratchbuf_sz = sizeof(pbufs->scratchbuf);
++	char *scratchbuf = &pbufs->scratchbuf[0];
++	size_t len;
++
++	len = scnprintf(scratchbuf, scratchbuf_sz,
++			"** replaying previous printk message **\n");
++
++	__console_prepend_scratch(pmsg, len);
++}
++
++/*
+  * Read and format the specified record (or a later record if the specified
+  * record is not available).
+  *