diff options
| author | John Ogness <john.ogness@linutronix.de> | 2024-09-04 14:05:30 +0200 |
|---|---|---|
| committer | Petr Mladek <pmladek@suse.com> | 2024-09-04 15:56:32 +0200 |
| commit | 5102981d5e2a5a7a12424b5d26c7524ac2899898 (patch) | |
| tree | 546c0a008b95bc7241f81366856663fe553372e0 /kernel/printk/printk.c | |
| parent | printk: Provide helper for message prepending (diff) | |
| download | linux-5102981d5e2a5a7a12424b5d26c7524ac2899898.tar.xz linux-5102981d5e2a5a7a12424b5d26c7524ac2899898.zip | |
printk: nbcon: Show replay message on takeover
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>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20240904120536.115780-12-john.ogness@linutronix.de
Signed-off-by: Petr Mladek <pmladek@suse.com>
Diffstat (limited to 'kernel/printk/printk.c')
| -rw-r--r-- | kernel/printk/printk.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index e9458569bcfd..c27dc54f4151 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -2903,6 +2903,17 @@ void console_prepend_dropped(struct printk_message *pmsg, unsigned long dropped) } /* + * 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) +{ + console_prepend_message(pmsg, "** replaying previous printk message **\n"); +} + +/* * Read and format the specified record (or a later record if the specified * record is not available). * |