linux/drivers/tty, branch v5.11

tty: avoid using vfs_iocb_iter_write() for redirected console writes

2021-01-29T21:12:17Z

It turns out that the vfs_iocb_iter_{read,write}() functions are entirely broken, and don't actually use the passed-in file pointer for IO - only for the preparatory work (permission checking and for the write_iter function lookup). That worked fine for overlayfs, which always builds the new iocb with the same file pointer that it passes in, but in the general case it ends up doing nonsensical things (and could cause an iterator call that doesn't even match the passed-in file pointer). This subtly broke the tty conversion to write_iter in commit 9bb48c82aced ("tty: implement write_iter"), because the console redirection didn't actually end up redirecting anything, since the passed-in file pointer was basically ignored, and the actual write was done with the original non-redirected console tty after all. The main visible effect of this is that the console messages were no longer logged to /var/log/boot.log during graphical boot. Fix the issue by simply not using the vfs write "helper" function at all, and just redirecting the write entirely internally to the tty layer. Do the target writability permission checks when actually registering the target tty with TIOCCONS instead of at write time. Fixes: 9bb48c82aced ("tty: implement write_iter") Reported-and-tested-by: Hans de Goede Cc: Greg Kroah-Hartman Cc: stable@kernel.org Signed-off-by: Linus Torvalds

Commit 9bb48c82aced ("tty: implement write_iter") converted the tty

2021-01-25T20:08:07Z

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 Signed-off-by: Linus Torvalds

Merge tag 'tty-5.11-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

2021-01-24T18:56:45Z

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

tty: fix up hung_up_tty_write() conversion

2021-01-22T10:01:55Z

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 Signed-off-by: Linus Torvalds Reviewed-by: Jiri Slaby Link: https://lore.kernel.org/r/CAHk-=wh+-rGsa=xruEWdg_fJViFG8rN9bpLrfLz=_yBYh2tBhA@mail.gmail.com Signed-off-by: Greg Kroah-Hartman

Merge 9bb48c82aced ("tty: implement write_iter") into tty-linus

2021-01-21T08:38:37Z

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

tty: implement write_iter

2021-01-21T00:48:47Z

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 Cc: Christoph Hellwig Cc: Greg Kroah-Hartman Cc: Al Viro Signed-off-by: Linus Torvalds

Merge tag 'riscv-for-linus-5.11-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

2021-01-16T19:00:08Z

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

Revert "init/console: Use ttynull as a fallback when there is no console"

2021-01-08T19:02:18Z

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 Reported-by: Vineet Gupta Reported-by: Thomas Meyer Signed-off-by: Petr Mladek Acked-by: Greg Kroah-Hartman Acked-by: Sergey Senozhatsky Signed-off-by: Linus Torvalds

riscv: Fix sifive serial driver

2021-01-08T02:02:13Z

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 Reviewed-by: Palmer Dabbelt Acked-by: Palmer Dabbelt Signed-off-by: Palmer Dabbelt

serial: mvebu-uart: fix tx lost characters at power off

2020-12-28T15:17:34Z

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 Cc: stable Link: https://lore.kernel.org/r/20201223191931.18343-1-pali@kernel.org Signed-off-by: Greg Kroah-Hartman