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path: root/drivers/tty
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2021-01-26serial: ifx6x60: Remove driver for deprecated platformAndy Shevchenko
Intel Moorestown and Medfield are quite old Intel Atom based 32-bit platforms, which were in limited use in some Android phones, tablets and consumer electronics more than eight years ago. There are no bugs or problems ever reported outside from Intel for breaking any of that platforms for years. It seems no real users exists who run more or less fresh kernel on it. The commit 05f4434bc130 ("ASoC: Intel: remove mfld_machine") also in align with this theory. Due to above and to reduce a burden of supporting outdated drivers we remove the support of outdated platforms completely. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Linus Walleij <linus.walleij@linaro.org> Link: https://lore.kernel.org/r/20210125150238.16980-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-26serial: stm32: Use of_device_get_match_data()Stephen Boyd
This driver casts away the constness of struct stm32_usart_info that is pointed to by the of match table. Use of_device_get_match_data() instead of of_match_device() here and push the const throughout the code so that we don't cast away const. This nicely avoids referencing the match table when it is undefined with configurations where CONFIG_OF=n and fixes the const issues. Signed-off-by: Stephen Boyd <swboyd@chromium.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> Cc: Alexandre Torgue <alexandre.torgue@st.com> Cc: Rob Herring <robh+dt@kernel.org> Cc: Frank Rowand <frowand.list@gmail.com> Cc: <linux-serial@vger.kernel.org> Signed-off-by: Rob Herring <robh@kernel.org> Link: https://lore.kernel.org/r/20210123034428.2841052-4-swboyd@chromium.org
2021-01-25Commit 9bb48c82aced ("tty: implement write_iter") converted the ttySami Tolvanen
layer to use write_iter. Fix the redirected_tty_write declaration also in n_tty and change the comparisons to use write_iter instead of write. [ Also moved the declaration of redirected_tty_write() to the proper location in a header file. The reason for the bug was the bogus extern declaration in n_tty.c silently not matching the changed definition in tty_io.c, and because it wasn't in a shared header file, there was no cross-checking of the declaration. Sami noticed because Clang's Control Flow Integrity checking ended up incidentally noticing the inconsistent declaration. - Linus ] Fixes: 9bb48c82aced ("tty: implement write_iter") Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-01-25Merge 5.11-rc5 into tty-nextGreg Kroah-Hartman
We need the fixes in here and this resolves a merge issue in drivers/tty/tty_io.c Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-24Merge tag 'tty-5.11-rc5' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty/serial fixes from Greg KH: "Here are three small tty/serial fixes for 5.11-rc5 to resolve reported problems: - two patches to fix up writing to ttys with splice - mvebu-uart driver fix for reported problem All of these have been in linux-next with no reported problems" * tag 'tty-5.11-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: tty: fix up hung_up_tty_write() conversion tty: implement write_iter serial: mvebu-uart: fix tx lost characters at power off
2021-01-22tty: fix up hung_up_tty_write() conversionLinus Torvalds
In commit "tty: implement write_iter", I left the write_iter conversion of the hung up tty case alone, because I incorrectly thought it didn't matter. Jiri showed me the errors of my ways, and pointed out the problems with that incomplete conversion. Fix it all up. Reported-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Link: https://lore.kernel.org/r/CAHk-=wh+-rGsa=xruEWdg_fJViFG8rN9bpLrfLz=_yBYh2tBhA@mail.gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-22tty: fix up iterate_tty_read() EOVERFLOW handlingLinus Torvalds
When I converted the tty_ldisc_ops 'read()' function to take a kernel pointer, I was a bit too aggressive about the ldisc returning EOVERFLOW. Yes, we want to have EOVERFLOW override any partially read data (because the whole point is that the buffer was too small for the whole packet, and we don't want to see partial packets), but it shouldn't override a previous EFAULT. And in fact, it really is just EOVERFLOW that is special and should throw away any partially read data, not "any error". Admittedly EOVERFLOW is currently the only one that can happen for a continuation read - and if the first read iteration returns an error we won't have this issue. So this is more of a technicality, but let's just make the intent very explicit, and re-organize the error handling a bit so that this is all clearer. Reported-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Link: https://lore.kernel.org/r/CAHk-=wh+-rGsa=xruEWdg_fJViFG8rN9bpLrfLz=_yBYh2tBhA@mail.gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-22tty: fix up hung_up_tty_read() conversionLinus Torvalds
In commit "tty: implement read_iter", I left the read_iter conversion of the hung up tty case alone, because I incorrectly thought it didn't matter. Jiri showed me the errors of my ways, and pointed out the problems with that incomplete conversion. Fix it all up. Reported-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Link: https://lore.kernel.org/r/CAHk-=wh+-rGsa=xruEWdg_fJViFG8rN9bpLrfLz=_yBYh2tBhA@mail.gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-22tty: fix up hung_up_tty_write() conversionLinus Torvalds
In commit "tty: implement write_iter", I left the write_iter conversion of the hung up tty case alone, because I incorrectly thought it didn't matter. Jiri showed me the errors of my ways, and pointed out the problems with that incomplete conversion. Fix it all up. Reported-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Link: https://lore.kernel.org/r/CAHk-=wh+-rGsa=xruEWdg_fJViFG8rN9bpLrfLz=_yBYh2tBhA@mail.gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-21Merge branch 'tty-splice' of ↵Greg Kroah-Hartman
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux into tty-next Fixes both the "splice/sendfile to a tty" and "splice/sendfile from a tty" regression from 5.10. * 'tty-splice' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux: tty: teach the n_tty ICANON case about the new "cookie continuations" too tty: teach n_tty line discipline about the new "cookie continuations" tty: clean up legacy leftovers from n_tty line discipline tty: implement read_iter tty: convert tty_ldisc_ops 'read()' function to take a kernel pointer tty: implement write_iter
2021-01-21Merge 9bb48c82aced ("tty: implement write_iter") into tty-linusGreg Kroah-Hartman
We want the single "splice/sendfile to a tty" regression fix into tty-linus so it can get into 5.11-final, while the larger patch series fixing "splice/sendfile from a tty" should wait for 5.12-rc1 so that we get more testing. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-20tty: teach the n_tty ICANON case about the new "cookie continuations" tooLinus Torvalds
The ICANON case is a bit messy, since it has to look for the line ending, and has special code to then suppress line ending characters if they match the __DISABLED_CHAR. So it actually looks up the line ending even past the point where it knows it won't copy it to the result buffer. That said, apart from all those odd legacy N_TTY ICANON cases, the actual "should we continue copying" logic isn't really all that complicated or different from the non-canon case. In fact, the lack of "wait for at least N characters" arguably makes the repeat case slightly simpler. It really just boils down to "there's more of the line to be copied". So add the necessarily trivial logic, and now the N_TTY case will give long result lines even when in canon mode. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-01-20tty: teach n_tty line discipline about the new "cookie continuations"Linus Torvalds
With the conversion to do the tty ldisc read operations in small chunks, the n_tty line discipline became noticeably slower for throughput oriented loads, because rather than read things in up to 2kB chunks, it would return at most 64 bytes per read() system call. The cost is mainly all in the "do system calls over and over", not really in the new "copy to an extra kernel buffer". This can be fixed by teaching the n_tty line discipline about the "cookie continuation" model, which the chunking code supports because things like hdlc need to be able to handle packets up to 64kB in size. Doing that doesn't just get us back to the old performace, but to much better performance: my stupid "copy 10MB of data over a pty" test program is now almost twice as fast as it used to be (going down from 0.1s to 0.054s). This is entirely because it now creates maximal chunks (which happens to be "one byte less than one page" due to how we do the circular tty buffers). NOTE! This case only handles the simpler non-icanon case, which is the one where people may care about throughput. I'm going to do the icanon case later too, because while performance isn't a major issue for that, there may be programs that think they'll always get a full line and don't like the 64-byte chunking for that reason. Such programs are arguably buggy (signals etc can cause random partial results from tty reads anyway), and good programs will handle such partial reads, but expecting everybody to write "good programs" has never been a winning policy for the kernel.. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-01-20tty: clean up legacy leftovers from n_tty line disciplineLinus Torvalds
Back when the line disciplines did their own direct user accesses, they had to deal with the data copy possibly failing in the middle. Now that the user copy is done by the tty_io.c code, that failure case no longer exists. Remove the left-over error handling code that cannot trigger. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-01-20tty: implement write_iterLinus Torvalds
This makes the tty layer use the .write_iter() function instead of the traditional .write() functionality. That allows writev(), but more importantly also makes it possible to enable .splice_write() for ttys, reinstating the "splice to tty" functionality that was lost in commit 36e2c7421f02 ("fs: don't allow splice read/write without explicit ops"). Fixes: 36e2c7421f02 ("fs: don't allow splice read/write without explicit ops") Reported-by: Oliver Giles <ohw.giles@gmail.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-01-20tty: implement read_iterLinus Torvalds
Now that the ldisc read() function takes kernel pointers, it's fairly straightforward to make the tty file operations use .read_iter() instead of .read(). That automatically gives us vread() and friends, and also makes it possible to do .splice_read() on ttys again. Fixes: 36e2c7421f02 ("fs: don't allow splice read/write without explicit ops") Reported-by: Oliver Giles <ohw.giles@gmail.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-01-20tty: convert tty_ldisc_ops 'read()' function to take a kernel pointerLinus Torvalds
The tty line discipline .read() function was passed the final user pointer destination as an argument, which doesn't match the 'write()' function, and makes it very inconvenient to do a splice method for ttys. This is a conversion to use a kernel buffer instead. NOTE! It does this by passing the tty line discipline ->read() function an additional "cookie" to fill in, and an offset into the cookie data. The line discipline can fill in the cookie data with its own private information, and then the reader will repeat the read until either the cookie is cleared or it runs out of data. The only real user of this is N_HDLC, which can use this to handle big packets, even if the kernel buffer is smaller than the whole packet. Cc: Christoph Hellwig <hch@lst.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-01-20serial: remove sirf prima/atlas driverArnd Bergmann
The CSR SiRF prima2/atlas platforms are getting removed, so this driver is no longer needed. Cc: Barry Song <baohua@kernel.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Link: https://lore.kernel.org/r/20210120161324.3728294-1-arnd@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-20serial: mxs-auart: Remove <asm/cacheflush.h>Fabio Estevam
There is nothing in the driver that uses the definitions from <asm/cacheflush.h>. Remove the unused header file inclusion. Signed-off-by: Fabio Estevam <festevam@gmail.com> Link: https://lore.kernel.org/r/20210118152154.1644569-2-festevam@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-20serial: mxs-auart: Remove serial_mxs_probe_dt()Fabio Estevam
The mxs platform is devicetree-only, so there is no need to check whether it was instantiated via devicetree. Simplify the code my removing serial_mxs_probe_dt() and add its content into the main probe function. Signed-off-by: Fabio Estevam <festevam@gmail.com> Link: https://lore.kernel.org/r/20210118152154.1644569-1-festevam@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-20serial: fsl_lpuart: Use of_device_get_match_data()Fabio Estevam
The retrieval of driver data via of_device_get_match_data() can make the code simpler. Use of_device_get_match_data() to simplify the code. Signed-off-by: Fabio Estevam <festevam@gmail.com> Link: https://lore.kernel.org/r/20210118124447.1632092-1-festevam@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-16Merge tag 'riscv-for-linus-5.11-rc4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux Pull RISC-V fixes from Palmer Dabbelt: "There are a few more fixes than a normal rc4, largely due to the bubble introduced by the holiday break: - return -ENOSYS for syscall number -1, which previously returned an uninitialized value. - ensure of_clk_init() has been called in time_init(), without which clock drivers may not be initialized. - fix sifive,uart0 driver to properly display the baud rate. A fix to initialize MPIE that allows interrupts to be processed during system calls. - avoid erronously begin tracing IRQs when interrupts are disabled, which at least triggers suprious lockdep failures. - workaround for a warning related to calling smp_processor_id() while preemptible. The warning itself is suprious on currently availiable systems. - properly include the generic time VDSO calls. A fix to our kasan address mapping. A fix to the HiFive Unleashed device tree, which allows the Ethernet PHY to be properly initialized by Linux (as opposed to relying on the bootloader). - defconfig update to include SiFive's GPIO driver, which is present on the HiFive Unleashed and necessary to initialize the PHY. - avoid allocating memory while initializing reserved memory. - avoid allocating the last 4K of memory, as pointers there alias with syscall errors. There are also two cleanups that should have no functional effect but do fix build warnings: - drop a duplicated definition of PAGE_KERNEL_EXEC. - properly declare the asm register SP shim. - cleanup the rv32 memory size Kconfig entry, to reflect the actual size of memory availiable" * tag 'riscv-for-linus-5.11-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: RISC-V: Fix maximum allowed phsyical memory for RV32 RISC-V: Set current memblock limit RISC-V: Do not allocate memblock while iterating reserved memblocks riscv: stacktrace: Move register keyword to beginning of declaration riscv: defconfig: enable gpio support for HiFive Unleashed dts: phy: add GPIO number and active state used for phy reset dts: phy: fix missing mdio device and probe failure of vsc8541-01 device riscv: Fix KASAN memory mapping. riscv: Fixup CONFIG_GENERIC_TIME_VSYSCALL riscv: cacheinfo: Fix using smp_processor_id() in preemptible riscv: Trace irq on only interrupt is enabled riscv: Drop a duplicated PAGE_KERNEL_EXEC riscv: Enable interrupts during syscalls with M-Mode riscv: Fix sifive serial driver riscv: Fix kernel time_init() riscv: return -ENOSYS for syscall -1
2021-01-15tty: serial: Drop unused efm32 serial driverUwe Kleine-König
Support for this machine was just removed, so drop the now unused UART driver, too. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Link: https://lore.kernel.org/r/20210115155130.185010-7-u.kleine-koenig@pengutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-15tty: vcc: Drop impossible to hit WARN_ONUwe Kleine-König
vcc_get() returns the port that has provided port->index. As the port that is about to be removed isn't removed yet this trivially will find this port. So simplify the call to not assign an identical value to the port pointer and drop the warning that is never hit. Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Link: https://lore.kernel.org/r/20210114175718.137483-4-u.kleine-koenig@pengutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-15tty: vcc: Drop unnecessary if blockUwe Kleine-König
If vcc_probe() succeeded dev_set_drvdata() is called with a non-NULL value, and if vcc_probe() failed vcc_remove() isn't called. So there is no way dev_get_drvdata() can return NULL in vcc_remove() and the check can just go away. Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Link: https://lore.kernel.org/r/20210114175718.137483-3-u.kleine-koenig@pengutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-15tty: hvcs: Drop unnecessary if blockUwe Kleine-König
If hvcs_probe() succeeded dev_set_drvdata() is called with a non-NULL value, and if hvcs_probe() failed hvcs_remove() isn't called. So there is no way dev_get_drvdata() can return NULL in hvcs_remove() and the check can just go away. Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Link: https://lore.kernel.org/r/20210114175718.137483-2-u.kleine-koenig@pengutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-13tty: serial: owl: Add support for kernel debuggerCristian Ciocaltea
Implement 'poll_put_char' and 'poll_get_char' callbacks in struct 'owl_uart_ops' that enables OWL UART to be used for kernel debugging over serial line. Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@gmail.com> Link: https://lore.kernel.org/r/026543195b9aeefb339d90abc5660a6ac7463c63.1610484108.git.cristian.ciocaltea@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-08Revert "init/console: Use ttynull as a fallback when there is no console"Petr Mladek
This reverts commit 757055ae8dedf5333af17b3b5b4b70ba9bc9da4e. The commit caused that ttynull was used as the default console on several systems[1][2][3]. As a result, the console was blank even when a better alternative existed. It happened when there was no console configured on the command line and ttynull_init() was the first initcall calling register_console(). Or it happened when /dev/ did not exist when console_on_rootfs() was called. It was not able to open /dev/console even though a console driver was registered. It tried to add ttynull console but it obviously did not help. But ttynull became the preferred console and was used by /dev/console when it was available later. The commit tried to fix a historical problem that have been there for ages. The primary motivation was the commit 3cffa06aeef7ece30f6 ("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 should 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. [1] https://lore.kernel.org/linux-kselftest/20201221144302.GR4077@smile.fi.intel.com/ [2] https://lore.kernel.org/lkml/d2a3b3c0-e548-7dd1-730f-59bc5c04e191@synopsys.com/ [3] https://patchwork.ozlabs.org/project/linux-um/patch/20210105120128.10854-1-thomas@m3y3r.de/ Reported-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reported-by: Vineet Gupta <vgupta@synopsys.com> Reported-by: Thomas Meyer <thomas@m3y3r.de> Signed-off-by: Petr Mladek <pmladek@suse.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-01-07riscv: Fix sifive serial driverDamien Le Moal
Setup the port uartclk in sifive_serial_probe() so that the base baud rate is correctly printed during device probe instead of always showing "0". I.e. the probe message is changed from 38000000.serial: ttySIF0 at MMIO 0x38000000 (irq = 1, base_baud = 0) is a SiFive UART v0 to the correct: 38000000.serial: ttySIF0 at MMIO 0x38000000 (irq = 1, base_baud = 115200) is a SiFive UART v0 Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com> Acked-by: Palmer Dabbelt <palmerdabbelt@google.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-01-07tty: Protect disc_data in n_tty_close and n_tty_flush_bufferYan.Gao
n_tty_flush_buffer can happen in parallel with n_tty_close that the tty->disc_data will be set to NULL. n_tty_flush_buffer accesses tty->disc_data, so we must prevent n_tty_close clear tty->disc_data while n_tty_flush_buffer has a non-NULL view of tty->disc_data. So we need to make sure that accesses to disc_data are atomic using tty->termios_rwsem. There is an example I meet: When n_tty_flush_buffer accesses tty struct, the disc_data is right. However, then reset_buffer_flags accesses tty->disc_data, disc_data become NULL, So kernel crash when accesses tty->disc_data->real_tail. I guess there could be another thread change tty->disc_data to NULL, and during N_TTY line discipline, n_tty_close will set tty->disc_data to be NULL. So use tty->termios_rwsem to protect disc_data between close and flush_buffer. IP: reset_buffer_flags+0x9/0xf0 PGD 0 P4D 0 Oops: 0002 [#1] SMP CPU: 23 PID: 2087626 Comm: (agetty) Kdump: loaded Tainted: G Hardware name: UNISINSIGHT X3036P-G3/ST01M2C7S, BIOS 2.00.13 01/11/2019 task: ffff9c4e9da71e80 task.stack: ffffb30cfe898000 RIP: 0010:reset_buffer_flags+0x9/0xf0 RSP: 0018:ffffb30cfe89bca8 EFLAGS: 00010246 RAX: ffff9c4e9da71e80 RBX: ffff9c368d1bac00 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffff9c4ea17b50f0 RDI: 0000000000000000 RBP: ffffb30cfe89bcc8 R08: 0000000000000100 R09: 0000000000000001 R10: 0000000000000001 R11: 0000000000000000 R12: ffff9c368d1bacc0 R13: ffff9c20cfd18428 R14: ffff9c4ea17b50f0 R15: ffff9c368d1bac00 FS: 00007f9fbbe97940(0000) GS:ffff9c375c740000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000002260 CR3: 0000002f72233003 CR4: 00000000007606e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: ? n_tty_flush_buffer+0x2a/0x60 tty_buffer_flush+0x76/0x90 tty_ldisc_flush+0x22/0x40 vt_ioctl+0x5a7/0x10b0 ? n_tty_ioctl_helper+0x27/0x110 tty_ioctl+0xef/0x8c0 do_vfs_ioctl+0xa7/0x5e0 ? __audit_syscall_entry+0xaf/0x100 ? syscall_trace_enter+0x1d0/0x2b0 SyS_ioctl+0x79/0x90 do_syscall_64+0x6c/0x1b0 entry_SYSCALL64_slow_path+0x25/0x25 n_tty_flush_buffer --->tty->disc_data is OK ->reset_buffer_flags -->tty->disc_data is NULL Signed-off-by: Yan.Gao <gao.yanB@h3c.com> Reviewed-by: Xianting Tian <tian.xianting@h3c.com> Link: https://lore.kernel.org/r/20201210022507.30729-1-gao.yanB@h3c.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-07drivers:tty:pty: Fix a race causing data loss on closeCorey Minyard
Remove the tty_vhangup() from the pty code and just release the redirect. The tty_vhangup() results in data loss and data out of order issues. If you write to a pty master an immediately close the pty master, the receiver might get a chunk of data dropped, but then receive some later data. That's obviously something rather unexpected for a user. It certainly confused my test program. It turns out that tty_vhangup() on the slave pty gets called from pty_close(), and that causes the data on the slave side to be flushed, but due to races more data can be copied into the slave side's buffer after that. Consider the following sequence: thread1 thread2 thread3 ------- ------- ------- | |-write data into buffer, | | n_tty buffer is filled | | along with other buffers | |-pty_close(master) | |--tty_vhangup(slave) | |---tty_ldisc_hangup() | |----n_tty_flush_buffer() | |-----reset_buffer_flags() |-n_tty_read() | |--up_read(&tty->termios_rwsem); | |------down_read(&tty->termios_rwsem) | |------clear n_tty buffer contents | |------up_read(&tty->termios_rwsem) |--tty_buffer_flush_work() | |--schedules work calling | | flush_to_ldisc() | | |-flush_to_ldisc() | |--receive_buf() | |---tty_port_default_receive_buf() | |----tty_ldisc_receive_buf() | |-----n_tty_receive_buf2() | |------n_tty_receive_buf_common() | |-------down_read(&tty->termios_rwsem) | |-------__receive_buf() | | copies data into n_tty buffer | |-------up_read(&tty->termios_rwsem) |--down_read(&tty->termios_rwsem) |--copy buffer data to user >From this sequence, you can see that thread2 writes to the buffer then only clears the part of the buffer in n_tty. The n_tty receive buffer code then copies more data into the n_tty buffer. But part of the vhangup, releasing the redirect, is still required to avoid issues with consoles running on pty slaves. So do that. As far as I can tell, that is all that should be required. Signed-off-by: Corey Minyard <cminyard@mvista.com> Link: https://lore.kernel.org/r/20201124004902.1398477-3-minyard@acm.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-07tty: Export redirect releaseCorey Minyard
This will be required by the pty code when it removes tty_vhangup() on master close. Signed-off-by: Corey Minyard <cminyard@mvista.com> Link: https://lore.kernel.org/r/20201124004902.1398477-2-minyard@acm.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-07serial: stm32: update transmission complete error message in shutdownErwan Le Ray
The transmission complete error message provides the status of the ISR_USART_TC bit. This bit, when set, indicates that the transmission has not been completed. The bit status indication is not a very understandable information. The error message sent on console should indicate that the transmission is not complete, instead of providing USART_TC bit status. Update the error message and add a comment for better understanding. Signed-off-by: Erwan Le Ray <erwan.leray@foss.st.com> Link: https://lore.kernel.org/r/20210106162203.28854-9-erwan.leray@foss.st.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-07serial: stm32: clean probe and remove port deinitErwan Le Ray
Clean probe and remove port deinit by moving clk_disable_unprepare in a new dedicated deinit_port function. Signed-off-by: Erwan Le Ray <erwan.leray@foss.st.com> Signed-off-by: Etienne Carriere <etienne.carriere@foss.st.com> Link: https://lore.kernel.org/r/20210106162203.28854-8-erwan.leray@foss.st.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-07serial: stm32: update conflicting RTS/CTS config commentErwan Le Ray
The comment for conflicting RTS/CTS config refers to "st, hw-flow-ctrl", but this property is deprecated since the generic RTS/CTS property has been introduced by the patch 'serial: stm32: Use generic DT binding for announcing RTS/CTS lines'. Update the comment to refer to both generic and deprecated RTS/CTS properties. Signed-off-by: Erwan Le Ray <erwan.leray@foss.st.com> Link: https://lore.kernel.org/r/20210106162203.28854-7-erwan.leray@foss.st.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-07serial: stm32: add authorErwan Le Ray
Update email address add new author in authors list. Signed-off-by: Erwan Le Ray <erwan.leray@foss.st.com> Link: https://lore.kernel.org/r/20210106162203.28854-5-erwan.leray@foss.st.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-07serial: stm32: add "_usart" prefix in functions nameErwan Le Ray
Adds the prefix "_usart" in the name of stm32 usart functions in order to ease the usage of kernel trace and tools, such as f-trace. Allows to trace "stm32_usart_*" functions with f-trace. Without this patch, all the driver functions needs to be added manually in f-trace filter. Signed-off-by: Erwan Le Ray <erwan.leray@foss.st.com> Signed-off-by: Valentin Caron <valentin.caron@foss.st.com> Link: https://lore.kernel.org/r/20210106162203.28854-4-erwan.leray@foss.st.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-07serial: stm32: fix code cleaning warnings and checksErwan Le Ray
Fixes checkpatch --strict warnings and checks: - checkpatch --strict "Unnecessary parentheses" - checkpatch --strict "Blank lines aren't necessary before a close brace - checkpatch --strict "Alignment should match open parenthesis" - checkpatch --strict "Please don't use multiple blank lines" - checkpatch --strict "Comparison to NULL could be written ..." - visual check code ordering warning Signed-off-by: Erwan Le Ray <erwan.leray@foss.st.com> Link: https://lore.kernel.org/r/20210106162203.28854-3-erwan.leray@foss.st.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-07serial: stm32: fix DMA initialization error handlingErwan Le Ray
DMA initialization error handling is not properly implemented in the driver. Fix DMA initialization error handling by: - moving TX DMA descriptor request error handling in a new dedicated fallback_err label - adding error handling to TX DMA descriptor submission - adding error handling to RX DMA descriptor submission This patch depends on '24832ca3ee85 ("tty: serial: stm32-usart: Remove set but unused 'cookie' variables")' which unfortunately doesn't include a "Fixes" tag. Fixes: 3489187204eb ("serial: stm32: adding dma support") Signed-off-by: Erwan Le Ray <erwan.leray@foss.st.com> Link: https://lore.kernel.org/r/20210106162203.28854-2-erwan.leray@foss.st.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-07tty_port: drop last traces of low_latencyJiri Slaby
The main purpose of tty_port::low_latency was removed in commit a9c3f68f3cd8 (tty: Fix low_latency BUG) back in 2014. It was left in place for drivers as an optional tune knob. But only one driver has been using it until the previous commit. So remove this misconcept completely, given there are no users. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20210105120239.28031-11-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-07tty: cpm_uart, use port->flags instead of low_latencyJiri Slaby
This is the only in-kernel user of tty_port::low_latency. Switch this last one to test uport->flags directly as tty_port::low_latency is going away in the next patch. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20210105120239.28031-10-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-07vt: drop old FONT ioctlsJiri Slaby
Drop support for these ioctls: * PIO_FONT, PIO_FONTX * GIO_FONT, GIO_FONTX * PIO_FONTRESET As was demonstrated by commit 90bfdeef83f1 (tty: make FONTX ioctl use the tty pointer they were actually passed), these ioctls are not used from userspace, as: 1) they used to be broken (set up font on current console, not the open one) and racy (before the commit above) 2) KDFONTOP ioctl is used for years instead Note that PIO_FONTRESET is defunct on most systems as VGA_CONSOLE is set on them for ages. That turns on BROKEN_GRAPHICS_PROGRAMS which makes PIO_FONTRESET just return an error. We are removing KD_FONT_FLAG_OLD here as it was used only by these removed ioctls. kd.h header exists both in kernel and uapi headers, so we can remove the kernel one completely. Everyone includeing kd.h will now automatically get the uapi one. There are now unused definitions of the ioctl numbers and "struct consolefontdesc" in kd.h, but as it is a uapi header, I am not touching these. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20210105120239.28031-8-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-07vt/consolemap: do font sum unsignedJiri Slaby
The constant 20 makes the font sum computation signed which can lead to sign extensions and signed wraps. It's not much of a problem as we build with -fno-strict-overflow. But if we ever decide not to, be ready, so switch the constant to unsigned. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20210105120239.28031-7-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-078250_tegra: clean up tegra_uart_handle_breakJiri Slaby
* switch "do { A; } while (1)" to "while (1) { A; }" * switch "if (A) B; else break;" to "if (!A) break; B;" * remove unused assignment from p->serial_in() to status Objdump -d shows no difference. Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Jonathan Hunter <jonathanh@nvidia.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20210105120239.28031-6-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-07tty: pty, remove BUG_ON from pty_closeJiri Slaby
tty->ops->close is always called with a valid tty, so the BUG_ON cannot trigger. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20210105120239.28031-5-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-07vt: keyboard, defkeymap.c_shipped, approach the unicode tableJiri Slaby
Commit 5ce2087ed0eb (Fix default compose table initialization) fixed unicode table so that the values are not sign extended. The upstream (kbd package) chose a different approach. They use hexadecimal values. So use the same, so that the output of loadkeys and our shipped file correspond more to each other. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20210105120239.28031-4-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-07vt: keyboard, defkeymap.c_shipped, approach the definitionsJiri Slaby
loadkeys (from kbd) generates 'unsigned short' instead of 'u_short' since 2.0.3. It also marks maps as 'static' for longer than kbd's history. So adapt the shipped defkeymap.c to conform more to loadkeys output. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20210105120239.28031-3-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-07vt: keyboard, make keyboard_tasklet localJiri Slaby
Now that the last extern user of the tasklet (set_leds) is in keyboard.c, we can make keyboard_tasklet local to this unit too. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20210105120239.28031-2-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-07vt: move set_leds to keyboard.cJiri Slaby
set_leds and compute_shiftstate are called from a single place in vt.c. Let's combine these two into vt_set_leds_compute_shiftstate. This allows for making keyboard_tasklet local in the next patch. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20210105120239.28031-1-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-28serial: mvebu-uart: fix tx lost characters at power offPali Rohár
Commit c685af1108d7 ("serial: mvebu-uart: fix tx lost characters") fixed tx lost characters at low baud rates but started causing tx lost characters when kernel is going to power off or reboot. TX_EMP tells us when transmit queue is empty therefore all characters were transmitted. TX_RDY tells us when CPU can send a new character. Therefore we need to use different check prior transmitting new character and different check after all characters were sent. This patch splits polling code into two functions: wait_for_xmitr() which waits for TX_RDY and wait_for_xmite() which waits for TX_EMP. When rebooting A3720 platform without this patch on UART is print only: [ 42.699� And with this patch on UART is full output: [ 39.530216] reboot: Restarting system Fixes: c685af1108d7 ("serial: mvebu-uart: fix tx lost characters") Signed-off-by: Pali Rohár <pali@kernel.org> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20201223191931.18343-1-pali@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>