[PATCH 01/33] dummycon: Sprinkle locking checks

From: Daniel Vetter
Date: Tue May 28 2019 - 05:06:35 EST


As part of trying to understand the locking (or lack thereof) in the
fbcon/vt/fbdev maze, annotate everything.

Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxxx>
Reviewed-by: Sam Ravnborg <sam@xxxxxxxxxxxx>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@xxxxxxxxxxx>
Cc: Hans de Goede <hdegoede@xxxxxxxxxx>
Cc: Daniel Vetter <daniel.vetter@xxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Nicolas Pitre <nicolas.pitre@xxxxxxxxxx>
---
drivers/video/console/dummycon.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/drivers/video/console/dummycon.c b/drivers/video/console/dummycon.c
index ff886e99104b..2a0d0bda7faa 100644
--- a/drivers/video/console/dummycon.c
+++ b/drivers/video/console/dummycon.c
@@ -34,6 +34,8 @@ static bool dummycon_putc_called;

void dummycon_register_output_notifier(struct notifier_block *nb)
{
+ WARN_CONSOLE_UNLOCKED();
+
raw_notifier_chain_register(&dummycon_output_nh, nb);

if (dummycon_putc_called)
@@ -42,11 +44,15 @@ void dummycon_register_output_notifier(struct notifier_block *nb)

void dummycon_unregister_output_notifier(struct notifier_block *nb)
{
+ WARN_CONSOLE_UNLOCKED();
+
raw_notifier_chain_unregister(&dummycon_output_nh, nb);
}

static void dummycon_putc(struct vc_data *vc, int c, int ypos, int xpos)
{
+ WARN_CONSOLE_UNLOCKED();
+
dummycon_putc_called = true;
raw_notifier_call_chain(&dummycon_output_nh, 0, NULL);
}
--
2.20.1