aff56c67b0
This reverts commit757055ae8d. The commit caused that ttynull was used as the default console on many systems. It happened when there was no console configured on the command line and ttynull_init() was the first initcall calling register_console(). The commit fixed a historical problem that have been there for ages. The primary motivation was the commit3cffa06aee("printk/console: Allow to disable console output by using console="" or console=null"). It provided a clean solution for a workaround that was widely used and worked only by chance. This revert causes that the console="" or console=null command line options will again work only by chance. These options will cause that a particular console will be preferred and the default (tty) ones will not get enabled. There will be no console registered at all. As a result there won't be stdin, stdout, and stderr for the init process. But it worked exactly this way even before. The proper solution has to fulfill many conditions: + Register ttynull only when explicitly required or as the ultimate fallback. + ttynull must get associated with /dev/console but it must not become preferred console when used as a fallback. Especially, it must still be possible to replace it by a better console later. Such a change requires clean up of the register_console() code. Otherwise, it would be even harder to follow. Especially, the use of has_preferred_console and CON_CONSDEV flag is tricky. The clean up is risky. The ordering of consoles is not well defined. And any changes tend to break existing user settings. Do the revert at the least risky solution for now. Fixes:757055ae8d("init/console: Use ttynull as a fallback when there is no console") Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20210107164400.17904-2-pmladek@suse.com Signed-off-by: Greg Kroah-Hartman <gregkh@google.com> Change-Id: I839b9bd17c7280b538f04de8d6b08885bb5d6585
7.3 KiB
7.3 KiB