From cd3a1b8562d28490b334a61d5eb05df3d722d91e Mon Sep 17 00:00:00 2001 From: Jan Kiszka Date: Mon, 12 May 2008 21:21:04 +0200 Subject: [PATCH] printk: don't prefer unsuited consoles on registration console election: If some console happens to be registered first which does not provide a tty binding (!console->device), it prevents that more suited consoles which are registered later on can enter the candidate pool for console_device(). This is observable with KGDB's console which may already be registered (and exploited!) during early debugger connections, that is before any regular console registration. This patch fixes the issue by postponing the final, automated preferred_console selection until someone with a non-NULL device handler comes around. Signed-off-by: Jan Kiszka Cc: Jason Wessel Cc: Gerd Hoffmann Cc: Michael Ellerman Signed-off-by: Andrew Morton Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- kernel/printk.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/kernel/printk.c b/kernel/printk.c index 8b42f87e311..7d555615223 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -1157,8 +1157,11 @@ void register_console(struct console *console) console->index = 0; if (console->setup == NULL || console->setup(console, NULL) == 0) { - console->flags |= CON_ENABLED | CON_CONSDEV; - preferred_console = 0; + console->flags |= CON_ENABLED; + if (console->device) { + console->flags |= CON_CONSDEV; + preferred_console = 0; + } } }