When in time-travel mode (infinite-cpu or external) time should not pass
for writing to the console. As such, it makes sense to put the FD for
the output side into blocking mode and simply let any write to it hang.
If we did not do this, then time could pass waiting for the console to
become writable again. This is not desirable as it has random effects on
the clock between runs.
Implement this by duplicating the FD if output is active in a relevant
mode and setting the duplicate to be blocking. This avoids changing the
input channel to be blocking should it exists. After this, use the
blocking FD for all write operations and do not allocate an IRQ it is
set.
Without time-travel mode fd_out will always match fd_in and IRQs are
registered.
Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Link: https://patch.msgid.link/20231018123643.1255813-4-benjamin@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Switch character types to u8 and sizes to size_t. To conform to
characters/sizes in the rest of the tty layer.
Note we use __u8 in the userspace files.
Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: linux-um@lists.infradead.org
Link: https://lore.kernel.org/r/20231206073712.17776-27-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
All uses of reactivate_chan() were removed by
commit 940b241d90 ("um: Remove obsolete reenable_XX
calls"), so remove the declaration, too.
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Convert files to use SPDX header. All files are licensed under the GPLv2.
Signed-off-by: Alex Dewar <alex.dewar@gmx.co.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
The tty below tty_port might get destroyed by the tty layer
while we hold a reference to it.
So we have to carry tty_port around...
Signed-off-by: Richard Weinberger <richard@nod.at>
Now, we start converting tty buffer functions to actually use
tty_port. This will allow us to get rid of the need of tty in many
call sites. Only tty_port will needed and hence no more
tty_port_tty_get in those paths.
Now, the one where most of tty_port_tty_get gets removed:
tty_flip_buffer_push.
IOW we also closed all the races in drivers not using tty_port_tty_get
at all yet.
Also we move tty_flip_buffer_push declaration from include/linux/tty.h
to include/linux/tty_flip.h to all others while we are changing it
anyway.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
... and switch chan_interrupt() to directly calling close_one_chan(),
so we can lose delay_free_irq argument of close_chan() as well.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
... since chan_interrupt() might schedule it if there's too much
incoming data. Kill task argument of chan_interrupt(), while
we are at it - it's always &line->task.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
