From: Petr Mladek <pmladek@suse.com>
To: John Ogness <john.ogness@linutronix.de>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>,
Steven Rostedt <rostedt@goodmis.org>,
Marcos Paulo de Souza <mpdesouza@suse.com>,
Chris Down <chris@chrisdown.name>,
Naveen Kumar Chaudhary <naveen.osdev@gmail.com>,
linux-kernel@vger.kernel.org, Petr Mladek <pmladek@suse.com>
Subject: [PATCH v5 10/16] printk: Allow to debug misuse of add_or_update_preferred_console()
Date: Tue, 29 Sep 2026 14:05:40 +0200 [thread overview]
Message-ID: <20260929120546.328616-11-pmladek@suse.com> (raw)
In-Reply-To: <20260929120546.328616-1-pmladek@suse.com>
__add_preferred_console() should always be called only when either @name
or @devname is defined. Allow to debug the case when they are misused.
Use WARN_ON() because it is rather an implementation problem, it should
never happen. Also the consoles are typically added during boot so this
should not panic a running system even when panic_on_warn is enabled.
Signed-off-by: Petr Mladek <pmladek@suse.com>
---
kernel/printk/printk.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index b458a920ce5a..683083405230 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -2585,7 +2585,7 @@ static int add_or_update_preferred_console(unsigned int i,
pc = &preferred_consoles[i];
- if (!name && !devname)
+ if (WARN_ON(!name && !devname))
return -EINVAL;
if (devname) {
--
2.55.0
next prev parent reply other threads:[~2026-09-29 12:07 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-29 12:05 [PATCH v5 00/16] printk: Clean up preferred console handling Petr Mladek
2026-09-29 12:05 ` [PATCH v5 01/16] printk: Rename struct console_cmdline to preferred_console Petr Mladek
2026-09-29 12:05 ` [PATCH v5 02/16] printk: Rename preferred_console to preferred_dev_console Petr Mladek
2026-09-29 12:05 ` [PATCH v5 03/16] printk: Cleanup _braille_(un)register_console() wrappers Petr Mladek
2026-09-29 12:05 ` [PATCH v5 04/16] printk: Separate code for adding/updating preferred console metadata Petr Mladek
2026-09-29 12:05 ` [PATCH v5 05/16] printk: Prefer the console either via name or devname exclusively Petr Mladek
2026-09-29 12:05 ` [PATCH v5 06/16] printk: Check that index is not defined when a console is preferred via devname Petr Mladek
2026-09-29 12:05 ` [PATCH v5 07/16] printk: Ensure consistent name and devname when updating preferred console Petr Mladek
2026-09-29 12:05 ` [PATCH v5 08/16] printk: Do not quietly ignore adding entry for a preferred console when there is no space Petr Mladek
2026-09-29 12:05 ` [PATCH v5 09/16] printk: Allow to override options via the command line Petr Mladek
2026-09-29 12:05 ` Petr Mladek [this message]
2026-09-29 12:05 ` [PATCH v5 11/16] console/braille: Lock console->setup() call during the registration Petr Mladek
2026-09-29 12:05 ` [PATCH v5 12/16] printk: Separate code for enabling console Petr Mladek
2026-09-29 12:05 ` [PATCH v5 13/16] printk: Try to register each console as Braille first Petr Mladek
2026-09-29 12:05 ` [PATCH v5 14/16] printk: Do not set Braille console as preferred_console Petr Mladek
2026-09-29 12:05 ` [PATCH v5 15/16] printk: Modify try_enable_default_console() to return error/success Petr Mladek
2026-09-29 12:05 ` [PATCH v5 16/16] printk: Try enable preferred consoles only when there are any Petr Mladek
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