commit d412275444 upstream.
Speakup has only one speakup_tty variable to store the tty it is managing. This
makes sense since its codebase currently assumes that there is only one user who
controls the screen reading.
That however means that we have to forbid using the line discipline several
times, otherwise the second closure would try to free a NULL ldisc_data, leading to
general protection fault: 0000 [#1] SMP KASAN PTI
RIP: 0010:spk_ttyio_ldisc_close+0x2c/0x60
Call Trace:
tty_ldisc_release+0xa2/0x340
tty_release_struct+0x17/0xd0
tty_release+0x9d9/0xcc0
__fput+0x231/0x740
task_work_run+0x12c/0x1a0
do_exit+0x9b5/0x2230
? release_task+0x1240/0x1240
? __do_page_fault+0x562/0xa30
do_group_exit+0xd5/0x2a0
__x64_sys_exit_group+0x35/0x40
do_syscall_64+0x89/0x2b0
? page_fault+0x8/0x30
entry_SYSCALL_64_after_hwframe+0x44/0xa9
Cc: stable@vger.kernel.org
Reported-by: 秦世松 <qinshisong1205@gmail.com>
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Tested-by: Shisong Qin <qinshisong1205@gmail.com>
Link: https://lore.kernel.org/r/20201110183541.fzgnlwhjpgqzjeth@function
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix coding style issues, detected by checkpatch.pl "CHECK: Comparison to
NULL could be written !tty->ops->write"
Signed-off-by: Bhagyashri Dighole <digholebhagyashri@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In this driver, both function the same way, but we want to eventually
kill off semaphores, so a completion is the better choice here.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add a pair of braces to make all arms of the if statement consistent.
Issue found by checkpatch.pl.
Signed-off-by: Maya Nakamura <m.maya.nakamura@gmail.com>
Acked-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add blank line after declaration. Issue found with checkpatch.
Signed-off-by: Nishka Dasgupta <nishka.dasgupta_ug18@ashoka.edu.in>
Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This extends spk_io_ops with a synth_out_unicode which takes a u16 character
instead of just a byte, and extends spk_ttyio to implement it to emit
utf-8. spk_do_catch_up_unicode can then be introduced to benefit from
synth_out_unicode, and speakup_dummy made to use spk_do_catch_up_unicode instead
of spk_do_catch_up.
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Match alignment with the open parenthesis to conform to the Linux kernel
coding style. Issue found using checkpatch.
Signed-off-by: Santha Meena Ramamoorthy <santhameena13@gmail.com>
Acked-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.
Fix up the remaining staging speakup files to have a proper SPDX
identifier, based on the license text in the file itself. The SPDX
identifier is a legally binding shorthand, which can be used instead of
the full boiler plate text.
This work is based on a script and data from Thomas Gleixner, Philippe
Ombredanne, and Kate Stewart.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: William Hubbs <w.d.hubbs@gmail.com>
Cc: Chris Brannon <chris@the-brannons.com>
Cc: Kirk Reiser <kirk@reisers.ca>
Cc: Samuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This is a patch to the spk_ttyio.c file that fix up a comment block
warninig, found by checkpatch.pl tool, by adding */ on a separte line.
WARNING: Block comments use a trailing */ on a separate line
Signed-off-by: Mihaela Muraru <mihaela.muraru21@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Remove print statement following unsuccessful kmalloc when there
is not enough memory. Kmalloc and variants normally produce a
backtrace in such a case. Hence, a print statement is not necessary.
Found using the following Coccinelle semantic patch:
@@
identifier i;
@@
i = (\(kmalloc\|devm_kzalloc\|kmalloc_array\|
devm_ioremap\|usb_alloc_urb\|alloc_netdev\|dev_alloc_skb\|
kzalloc\|kcalloc\|kmem_cache_alloc\|kmem_cache_zalloc\|
kmem_cache_alloc_node\|kmalloc_node\|kzalloc_node\)(...));
(
if (i == NULL)
{
-\(DBG_8723A\|printk\|pr_err\|CERROR\|DBG_88E\)(...);
...when any
}
|
if (!i)
{
-\(DBG_8723A\|printk\|pr_err\|CERROR\|DBG_88E\)(...);
...when any
}
)
@@
identifier i;
@@
(
- if (i == NULL) {
+ if (i == NULL)
return ...;
- }
|
- if (!i) {
+ if (!i)
return ...;
- }
)
Signed-off-by: Meghana Madhyastha <meghana.madhyastha@gmail.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch replaces call to tty_open_by_driver with a tty_kopen and
uses tty_kclose instead of tty_release_struct to close it.
Signed-off-by: Okash Khawaja <okash.khawaja@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When an external USB synth is unplugged while the module is loaded, we
get a null pointer deref. This is because the tty disappears while
speakup tries to use to to communicate with the synth. This patch fixes
it by checking tty for null before using it. Since tty can become null
between the check and its usage, a mutex is introduced. tty usage is
now surrounded by the mutex, as is the code in speakup_ldisc_close which
sets the tty to null. The mutex also serialises calls to tty from
speakup code.
In case of tty being null, this sets synth->alive to zero and restarts
ttys in case they were stopped by speakup.
Signed-off-by: Okash Khawaja <okash.khawaja@gmail.com>
Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Testing has shown that lp* devices don't work correctly with speakup
just yet. That will require some additional work. Until then, this patch
removes code related to that.
Signed-off-by: Okash Khawaja <okash.khawaja@gmail.com>
Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch makes use of functions added in the previous patch. It
registers ldisc during init of main speakup module and unregisters it
during exit. It also removes the code to register ldisc every time a
synth module is loaded. This way we only register the ldisc once when
main speakup module is loaded. Since main speakup module is required by
all synth modules, it is only unloaded when all synths have been
unloaded. Therefore we unregister the ldisc once, when all speakup
related references to the ldisc have returned. In unlikely scenario of
something outside speakup using the ldisc, the ldisc refcount check in
tty_unregister_ldisc will ensure that it is not unregistered while in
use.
The function to register ldisc doesn't cause speakup init function to
fail. That is different from current behaviour where failure to register
ldisc results in failure to load the specific synth module. This is
because speakup module is also required by those synths which don't use
tty and ldisc. We don't want to prevent those modules from loading when
ldisc fails to register. The synth modules will correctly fail when
trying to set N_SPEAKUP to tty, if ldisc registrationi had failed.
Signed-off-by: Okash Khawaja <okash.khawaja@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch adds the above two functions and makes them available to
main.c where they will be called during init and exit functions of
main speakup module. Following patch will make use of them.
Signed-off-by: Okash Khawaja <okash.khawaja@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Speakup opens tty using tty_open_by_driver. When closing, it calls
tty_ldisc_release but doesn't close and remove the tty itself. As a
result, that tty cannot be opened from user space. This patch calls
tty_release_struct which ensures that tty is safely removed and freed
up. It also calls tty_ldisc_release, so speakup doesn't need to call it.
Signed-off-by: Okash Khawaja <okash.khawaja@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The helper function ser_to_dev does not need to be in global scope, so
make it static.
Cleans up sparse warning:
"warning: symbol 'ser_to_dev' was not declared. Should it be static?"
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Okash Khawaja <okash.khawaja@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch introduces new module parameter, dev, which takes a string
representing the device that the external synth is connected to, e.g.
ttyS0, ttyUSB0 etc. This is then used to communicate with the synth.
That way, speakup can support more than ttyS*. As of this patch, it
only supports ttyS*, ttyUSB* and selected synths for lp*. dev parameter
is only available for tty-migrated synths.
Users will either use dev or ser as both serve same purpose. This patch
maintains backward compatility by allowing ser to be specified. When
both are specified, whichever is non-default, i.e. not ttyS0, is used.
If both are non-default then dev is used.
Signed-off-by: Okash Khawaja <okash.khawaja@gmail.com>
Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch adds functionality to validate and convert either a device
name or 'ser' memmber of synth into dev_t. Subsequent patch in this set
will call it to convert user-specified device into device number. For
device name, this patch does some basic sanity checks on the string
passed in. It currently supports ttyS*, ttyUSB* and, for selected
synths, lp*.
The patch also introduces a string member variable named 'dev_name' to
struct spk_synth. 'dev_name' represents the device name - ttyUSB0 etc -
which needs conversion to dev_t.
Signed-off-by: Okash Khawaja <okash.khawaja@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch fixes checkpatch warnings about adding a blank line after
variable declaration.
Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In spk_ttyio_release we read tty's index but never do anything with it.
The patch removes this dead code.
Signed-off-by: Okash Khawaja <okash.khawaja@gmail.com>
Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We should check the flush_buffer method of a tty for null before
invoking it. Some drivers such as usbserial don't implement
flush_buffer. This will be required for upcoming patches where we expand
spk_ttyio to support more than just ttyS*.
Signed-off-by: Okash Khawaja <okash.khawaja@gmail.com>
Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This is a patch to the spk_ttyio.c file which fixes up the indent error
reported by the checkpatch.pl tool.
Signed-off-by: Rui Teng <rui.teng@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On most of the common arches char is signed so it can't ever == 0xff.
Let's fix this by making it a u8.
Fixes: 6b9ad1c742 ("staging: speakup: add send_xchar, tiocmset and input functionality for tty")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch fixes the issue where TTY-migrated synths would take a while
to shut up after hitting numpad enter key. When calling synth_flush,
even though XOFF character is sent as high priority, data buffered in
TTY layer is still sent to the synth. This patch flushes that buffered
data when synth_flush is called.
It also tries to ensure that hardware flow control is enabled, by
setting CRTSCTS using tty's termios.
Reported-by: John Covici <covici@ccs.covici.com>
Signed-off-by: Okash Khawaja <okash.khawaja@gmail.com>
Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch adds further TTY-based functionality, specifically implementation
of send_xchar and tiocmset methods, and input. send_xchar and tiocmset
methods simply delegate to corresponding TTY operations.
For input, it implements the receive_buf2 callback in tty_ldisc_ops of
speakup's ldisc. If a synth defines read_buff_add method then receive_buf2
simply delegates to that and returns.
For spk_ttyio_in, the data is passed from receive_buf2 thread to
spk_ttyio_in thread through spk_ldisc_data structure. It has following
members:
- char buf: represents data received
- struct semaphore sem: used to signal to spk_ttyio_in thread that data
is available to be read without having to busy wait
- bool buf_free: this is used in comination with mb() calls to syncronise
the two threads over buf
receive_buf2 only writes to buf if buf_free is true. The check for buf_free
and writing to buf are separated by mb() to ensure that spk_ttyio_in has read
buf before receive_buf2 writes to it. After writing, it ups the semaphore to
signal to spk_ttyio_in that there is now data to read.
spk_ttyio_in waits for data to read by downing the semaphore. Thus when
signalled by receive_buf2 thread above, it reads from buf and sets buf_free
to true. These two operations are separated by mb() to ensure that
receive_buf2 thread finds buf_free to be true only after buf has been read.
After that spk_ttyio_in calls tty_schedule_flip for subsequent data to come
in through receive_buf2.
Signed-off-by: Okash Khawaja <okash.khawaja@gmail.com>
Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This adds spk_ttyio.c file. It contains a set of functions which implement
those methods in spk_synth struct which relate to sending bytes out using
serial comms. Implementations in this file perform the same function but
using TTY subsystem instead. Currently synths access serial ports, directly
poking standard ISA ports by trying to steal them from serial driver. Some ISA
cards actually need this way of doing it, but most other synthesizers don't,
and can actually work by using the proper TTY subsystem through a new N_SPEAKUP
line discipline. So this adds the methods for drivers to switch to accessing
serial ports through the TTY subsystem, whenever appropriate.
Signed-off-by: Okash Khawaja <okash.khawaja@gmail.com>
Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Samuel Thibault