kernel/linux.git/drivers/tty/tty_ioctl.c, branch v6.6.132

tty: allow TIOCSLCKTRMIOS with CAP_CHECKPOINT_RESTORE

2024-02-05T20:14:32+00:00

[ Upstream commit e0f25b8992345aa5f113da2815f5add98738c611 ] The capability CAP_CHECKPOINT_RESTORE was introduced to allow non-root users to checkpoint and restore processes as non-root with CRIU. This change extends CAP_CHECKPOINT_RESTORE to enable the CRIU option '--shell-job' as non-root. CRIU's man-page describes the '--shell-job' option like this: Allow one to dump shell jobs. This implies the restored task will inherit session and process group ID from the criu itself. This option also allows to migrate a single external tty connection, to migrate applications like top. TIOCSLCKTRMIOS can only be done if the process has CAP_SYS_ADMIN and this change extends it to CAP_SYS_ADMIN or CAP_CHECKPOINT_RESTORE. With this change it is possible to checkpoint and restore processes which have a tty connection as non-root if CAP_CHECKPOINT_RESTORE is set. Acked-by: Christian Brauner Signed-off-by: Adrian Reber Acked-by: Andrei Vagin Link: https://lore.kernel.org/r/20231208143656.1019-1-areber@redhat.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

tty: make tty_change_softcar() more understandable

2023-08-11T19:12:44+00:00

* rename 'arg' to 'enable' as that is what it means. * make 'bit' a tcflag_t, not int, as that is what cflags are. Signed-off-by: "Jiri Slaby (SUSE)" Link: https://lore.kernel.org/r/20230810091510.13006-9-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman

tty: drop tty_debug_wait_until_sent()

2023-08-11T19:12:44+00:00

It's a nop for everyone as TTY_DEBUG_WAIT_UNTIL_SENT is never set. Provided, we have better debugging/printout mechanisms nowadays, remove this mechanism. Signed-off-by: "Jiri Slaby (SUSE)" Link: https://lore.kernel.org/r/20230810091510.13006-8-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman

tty: change tty_write_lock()'s ndelay parameter to bool

2023-08-11T19:12:44+00:00

It's a yes-no parameter, so convert it to bool to be obvious. Signed-off-by: "Jiri Slaby (SUSE)" Link: https://lore.kernel.org/r/20230810091510.13006-6-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman

tty: Prevent writing chars during tcsetattr TCSADRAIN/FLUSH

2023-03-29T08:55:53+00:00

If userspace races tcsetattr() with a write, the drained condition might not be guaranteed by the kernel. There is a race window after checking Tx is empty before tty_set_termios() takes termios_rwsem for write. During that race window, more characters can be queued by a racing writer. Any ongoing transmission might produce garbage during HW's ->set_termios() call. The intent of TCSADRAIN/FLUSH seems to be preventing such a character corruption. If those flags are set, take tty's write lock to stop any writer before performing the lower layer Tx empty check and wait for the pending characters to be sent (if any). The initial wait for all-writers-done must be placed outside of tty's write lock to avoid deadlock which makes it impossible to use tty_wait_until_sent(). The write lock is retried if a racing write is detected. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Signed-off-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20230317113318.31327-2-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman

tty_ioctl: Use BIT() for internal flags

2023-03-17T14:01:08+00:00

Convert internal flags to use BIT(). Signed-off-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20230309082035.14880-3-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman

tty: Return bool from tty_termios_hw_change()

2023-01-19T15:04:35+00:00

Change tty_termios_hw_change() to return bool. Reviewed-by: Jiri Slaby Reviewed-by: Johan Hovold Signed-off-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20230117090358.4796-11-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman

termios: start unifying non-UAPI parts of asm/termios.h

2022-09-09T08:44:34+00:00

* new header (linut/termios_internal.h), pulled by the users of those suckers * defaults for INIT_C_CC and externs for conversion helpers moved over there * remove termios-base.h (empty now) Signed-off-by: Al Viro Link: https://lore.kernel.org/r/YxDmptU7dNGZ+/Hn@ZenIV Signed-off-by: Greg Kroah-Hartman

termios: uninline conversion helpers

2022-09-09T08:44:34+00:00

default go into drivers/tty/tty_ioctl.c, unusual - into arch/*/kernel/termios.c (only alpha and sparc have those). Signed-off-by: Al Viro Link: https://lore.kernel.org/r/YxDmeUBHo0s/Ew8b@ZenIV Signed-off-by: Greg Kroah-Hartman

serial: Make ->set_termios() old ktermios const

2022-08-30T12:22:35+00:00

There should be no reason to adjust old ktermios which is going to get discarded anyway. Reviewed-by: Andy Shevchenko Signed-off-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20220816115739.10928-7-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman