[PATCH 6.12.y 1/3] console: introduce console_lock guard()s

[Sasha Levin <sashal@kernel.org>]

From: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>

[ Upstream commit 4847d1187402a5027d9a04393f12d52a5a1d7f98 ]

Having this, guards like these work:
  guard(console_lock)();
or
  scoped_guard(console_lock) {
    ...
  }

See e.g. "vc_screen: use guard()s" later in this series.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250814072456.182853-2-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Stable-dep-of: 226bd5603371 ("vc_screen: reload vc pointer before if (ret) in vcs_write() to avoid UAF")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 include/linux/console.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/include/linux/console.h b/include/linux/console.h
index eba367bf605da..cfc7125daf626 100644
--- a/include/linux/console.h
+++ b/include/linux/console.h
@@ -666,6 +666,8 @@ void vcs_remove_sysfs(int index);
  */
 extern atomic_t ignore_console_lock_warning;
 
+DEFINE_LOCK_GUARD_0(console_lock, console_lock(), console_unlock());
+
 extern void console_init(void);
 
 /* For deferred console takeover */
-- 
2.53.0