Public bug reported: [Impact] The agetty stopped working using serial tty when user logged out, especially if there is a remained process. The agetty failed to open tty device due to serial port used by previous process was not released.
[Test Case] 1. Run background processes from serial console $ while true; do sleep 10; done & 2. Log out $ logout 3. Read journal log by journalctl | tail Jan 28 16:07:01 ubuntu systemd[1]: Stopped Serial Getty on ttyAMA0. Jan 28 16:07:01 ubuntu systemd[1]: Started Serial Getty on ttyAMA0. Jan 28 16:07:02 ubuntu agetty[1643]: /dev/ttyAMA0: not a tty [Fix] The upstream has a fix since 4.20-rc6, which turns off TTY_IO_ERROR flag if port comes from console. The commit link is provided by https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/drivers/tty/tty_port.c?h=v4.20-rc6&id=2a48602615e0a2f563549c7d5c8d507f904cf96e [Regression Potential] Should be none, and it's regression becoz 4.4 kernel didn't have this case. ** Affects: linux (Ubuntu) Importance: Undecided Assignee: Woodrow Shen (woodrow-shen) Status: Confirmed ** Changed in: linux (Ubuntu) Status: New => Confirmed ** Changed in: linux (Ubuntu) Assignee: (unassigned) => Woodrow Shen (woodrow-shen) -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1808097 Title: Console got stuck using serial tty after logout Status in linux package in Ubuntu: Confirmed Bug description: [Impact] The agetty stopped working using serial tty when user logged out, especially if there is a remained process. The agetty failed to open tty device due to serial port used by previous process was not released. [Test Case] 1. Run background processes from serial console $ while true; do sleep 10; done & 2. Log out $ logout 3. Read journal log by journalctl | tail Jan 28 16:07:01 ubuntu systemd[1]: Stopped Serial Getty on ttyAMA0. Jan 28 16:07:01 ubuntu systemd[1]: Started Serial Getty on ttyAMA0. Jan 28 16:07:02 ubuntu agetty[1643]: /dev/ttyAMA0: not a tty [Fix] The upstream has a fix since 4.20-rc6, which turns off TTY_IO_ERROR flag if port comes from console. The commit link is provided by https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/drivers/tty/tty_port.c?h=v4.20-rc6&id=2a48602615e0a2f563549c7d5c8d507f904cf96e [Regression Potential] Should be none, and it's regression becoz 4.4 kernel didn't have this case. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1808097/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
