From: Hans de Goede Date: Fri, 10 Aug 2018 15:23:02 +0000 (+0200) Subject: fbcon: Do not takeover the console from atomic context X-Git-Tag: v4.19-rc1~37^2~1 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=df37e225f25933732c17e43cbe7d21eec31b24be;p=thirdparty%2Fkernel%2Fstable.git fbcon: Do not takeover the console from atomic context Taking over the console involves allocating mem with GFP_KERNEL, talking to drm drivers, etc. So this should not be done from an atomic context. But the console-output trigger deferred console takeover may happen from an atomic context, which leads to "BUG: sleeping function called from invalid context" errors. This commit fixes these errors by doing the deferred takeover from a workqueue. Signed-off-by: Hans de Goede [b.zolnierkie: remove unused variable] Signed-off-by: Bartlomiej Zolnierkiewicz --- diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c index ef8b2d0b7071b..75ebbbf0a1fbb 100644 --- a/drivers/video/fbdev/core/fbcon.c +++ b/drivers/video/fbdev/core/fbcon.c @@ -3592,13 +3592,24 @@ static int fbcon_init_device(void) } #ifdef CONFIG_FRAMEBUFFER_CONSOLE_DEFERRED_TAKEOVER +static void fbcon_register_existing_fbs(struct work_struct *work) +{ + int i; + + console_lock(); + + for_each_registered_fb(i) + fbcon_fb_registered(registered_fb[i]); + + console_unlock(); +} + static struct notifier_block fbcon_output_nb; +static DECLARE_WORK(fbcon_deferred_takeover_work, fbcon_register_existing_fbs); static int fbcon_output_notifier(struct notifier_block *nb, unsigned long action, void *data) { - int i; - WARN_CONSOLE_UNLOCKED(); pr_info("fbcon: Taking over console\n"); @@ -3607,8 +3618,8 @@ static int fbcon_output_notifier(struct notifier_block *nb, deferred_takeover = false; logo_shown = FBCON_LOGO_DONTSHOW; - for_each_registered_fb(i) - fbcon_fb_registered(registered_fb[i]); + /* We may get called in atomic context */ + schedule_work(&fbcon_deferred_takeover_work); return NOTIFY_OK; }