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2018-04-25tty: Use __GFP_NOFAIL for tty_ldisc_get()Tetsuo Handa
syzbot is reporting crashes triggered by memory allocation fault injection at tty_ldisc_get() [1]. As an attempt to handle OOM in a graceful way, we have tried commit 5362544bebe85071 ("tty: don't panic on OOM in tty_set_ldisc()"). But we reverted that attempt by commit a8983d01f9b7d600 ("Revert "tty: don't panic on OOM in tty_set_ldisc()"") due to reproducible crash. We should spend resource for finding and fixing race condition bugs rather than complicate error paths for 2 * sizeof(void *) bytes allocation failure. [1] https://syzkaller.appspot.com/bug?id=489d33fa386453859ead58ff5171d43772b13aa3 Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Reported-by: syzbot <syzbot+40b7287c2dc987c48c81@syzkaller.appspotmail.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Vegard Nossum <vegard.nossum@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Jiri Slaby <jslaby@suse.com> Cc: Peter Hurley <peter@hurleysoftware.com> Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-23tty: serial: xuartps: Setup early console when uartclk is also passedMichal Simek
Baudrate calculation depends on requested baudrate and uart clock. This patch is checking that uartclk is also passed. The same logic is used 8250_early.c/init_port function. Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-23tty: Don't call panic() at tty_ldisc_init()Tetsuo Handa
syzbot is reporting kernel panic [1] triggered by memory allocation failure at tty_ldisc_get() from tty_ldisc_init(). But since both tty_ldisc_get() and caller of tty_ldisc_init() can cleanly handle errors, tty_ldisc_init() does not need to call panic() when tty_ldisc_get() failed. [1] https://syzkaller.appspot.com/bug?id=883431818e036ae6a9981156a64b821110f39187 Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Reported-by: syzbot <syzkaller@googlegroups.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-23tty: Avoid possible error pointer dereference at tty_ldisc_restore().Tetsuo Handa
syzbot is reporting crashes [1] triggered by memory allocation failure at tty_ldisc_get() from tty_ldisc_restore(). While syzbot stops at WARN_ON() due to panic_on_warn == true, panic_on_warn == false will after all trigger an OOPS by dereferencing old->ops->num if IS_ERR(old) == true. We can simplify tty_ldisc_restore() as three calls (old->ops->num, N_TTY, N_NULL) to tty_ldisc_failto() in addition to avoiding possible error pointer dereference. If someone reports kernel panic triggered by forcing all memory allocations for tty_ldisc_restore() to fail, we can consider adding __GFP_NOFAIL for tty_ldisc_restore() case. [1] https://syzkaller.appspot.com/bug?id=6ac359c61e71d22e06db7f8f88243feb11d927e7 Reported-by: syzbot+40b7287c2dc987c48c81@syzkaller.appspotmail.com Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Alan Cox <alan@llwyncelyn.cymru> Cc: Christoph Hellwig <hch@lst.de> Cc: Michal Hocko <mhocko@suse.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-23tty: serial: qcom_geni_serial: Use signed variable to get IRQKarthikeyan Ramasubramanian
The platform_get_irq can return error. Assigning the return value to an unsigned variable and checking it for negative value will always return false. Use an intermediate signed variable to get IRQ information, check for any error and then assign it to 'irq' variable inside uart_port structure. Signed-off-by: Karthikeyan Ramasubramanian <kramasub@codeaurora.org> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Stephen Boyd <swboyd@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-23earlycon: Use a pointer table to fix __earlycon_table strideDaniel Kurtz
Commit 99492c39f39f ("earlycon: Fix __earlycon_table stride") tried to fix __earlycon_table stride by forcing the earlycon_id struct alignment to 32 and asking the linker to 32-byte align the __earlycon_table symbol. This fix was based on commit 07fca0e57fca92 ("tracing: Properly align linker defined symbols") which tried a similar fix for the tracing subsystem. However, this fix doesn't quite work because there is no guarantee that gcc will place structures packed into an array format. In fact, gcc 4.9 chooses to 64-byte align these structs by inserting additional padding between the entries because it has no clue that they are supposed to be in an array. If we are unlucky, the linker will assign symbol "__earlycon_table" to a 32-byte aligned address which does not correspond to the 64-byte aligned contents of section "__earlycon_table". To address this same problem, the fix to the tracing system was subsequently re-implemented using a more robust table of pointers approach by commits: 3d56e331b653 ("tracing: Replace syscall_meta_data struct array with pointer array") 654986462939 ("tracepoints: Fix section alignment using pointer array") e4a9ea5ee7c8 ("tracing: Replace trace_event struct array with pointer array") Let's use this same "array of pointers to structs" approach for EARLYCON_TABLE. Fixes: 99492c39f39f ("earlycon: Fix __earlycon_table stride") Signed-off-by: Daniel Kurtz <djkurtz@chromium.org> Suggested-by: Aaron Durbin <adurbin@chromium.org> Reviewed-by: Rob Herring <robh@kernel.org> Tested-by: Guenter Roeck <groeck@chromium.org> Reviewed-by: Guenter Roeck <groeck@chromium.org> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-23serial: imx: fix cached UCR2 read on software resetStefan Agner
To reset the UART the SRST needs be cleared (low active). According to the documentation the bit will remain active for 4 module clocks until it is cleared (set to 1). Hence the real register need to be read in case the cached register indicates that the SRST bit is zero. This bug lead to wrong baudrate because the baud rate register got restored before reset completed in imx_flush_buffer. Fixes: 3a0ab62f43de ("serial: imx: implement shadow registers for UCRx and UFCR") Signed-off-by: Stefan Agner <stefan@agner.ch> Reviewed-by: Fabio Estevam <fabio.estevam@nxp.com> Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-23serial: imx: warn user when using unsupported configurationStefan Agner
When using half-duplex mode (which disables receiver during txing) the RTS signal cannot be driven low during transmission when using i.MX UART RTS/CTS control. This seems to be a limitation of the i.MX UART IP: The RTS (CTS_B) signal is controlled by the receiver. When the receiver is disabled, the signal stays in UART logic idle state which is high... If SER_RS485_RTS_ON_SEND is used, RTS needs to be high active during transmission. Since this is the default state of the RTS (CTS_B) signal when the receiver is off, half-duplex mode in this configuration works fine. However, a low-active RTS signal (flag SER_RS485_RTS_ON_SEND not set) cannot be generated when the receiver is turned off. Print an error if the user selects this unsupported configuration (both SER_RS485_RTS_ON_SEND and SER_RS485_RX_DURING_TX unset) and configure the closest working configuration (set the SER_RS485_RX_DURING_TX flag). Signed-off-by: Stefan Agner <stefan@agner.ch> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-22serial: mvebu-uart: Fix local flags handling on termios updateMarc Zyngier
Commit 68a0db1d7da2 reworked the baud rate selection, but also added a (not so) subtle change in the way the local flags (c_lflag in the termios structure) are handled, forcing the new flags to always be the same as the old ones. The reason for that particular change is both obscure and undocumented. It also completely breaks userspace. Something as trivial as getty is unusable: <example> Debian GNU/Linux 9 sy-borg ttyMV0 sy-borg login: root root [timeout] Debian GNU/Linux 9 sy-borg ttyMV0 </example> which is quite obvious in retrospect: getty cannot get in control of the echo mode, is stuck in canonical mode, and times out without ever seeing anything valid. It also begs the question of how this change was ever tested. The fix is pretty obvious: stop messing with c_lflag, and the world will be a happier place. Cc: stable@vger.kernel.org # 4.15+ Fixes: 68a0db1d7da2 ("serial: mvebu-uart: add function to change baudrate") Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-22tty: n_gsm: Fix DLCI handling for ADM mode if debug & 2 is not setTony Lindgren
At least on droid 4 with control channel in ADM mode, there is no response to Modem Status Command (MSC). Currently gsmtty_modem_update() expects to have data in dlci->modem_rx unless debug & 2 is set. This means that on droid 4, things only work if debug & 2 is set. Let's fix the issue by ignoring empty dlci->modem_rx for ADM mode. In the AMD mode, CMD_MSC will never respond and gsm_process_modem() won't get called to set dlci->modem_rx. And according to ts_127010v140000p.pdf, MSC is only relevant if basic option is chosen, so let's test for that too. Fixes: ea3d8465ab9b ("tty: n_gsm: Allow ADM response in addition to UA for control dlci") Cc: linux-serial@vger.kernel.org Cc: Alan Cox <alan@llwyncelyn.cymru> Cc: Dan Williams <dcbw@redhat.com> Cc: Jiri Prchal <jiri.prchal@aksignal.cz> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Marcel Partap <mpartap@gmx.net> Cc: Merlijn Wajer <merlijn@wizzup.org> Cc: Michael Nazzareno Trimarchi <michael@amarulasolutions.com> Cc: Michael Scott <michael.scott@linaro.org> Cc: Pavel Machek <pavel@ucw.cz> Cc: Peter Hurley <peter@hurleysoftware.com> Cc: Russ Gorby <russ.gorby@intel.com> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: Sebastian Reichel <sre@kernel.org> Signed-off-by: Tony Lindgren <tony@atomide.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-22tty: n_gsm: Fix long delays with control frame timeouts in ADM modeTony Lindgren
Commit ea3d8465ab9b ("tty: n_gsm: Allow ADM response in addition to UA for control dlci") added support for DLCI to stay in Asynchronous Disconnected Mode (ADM). But we still get long delays waiting for commands to other DLCI to complete: --> 5) C: SABM(P) Q> 0) C: UIH(F) Q> 0) C: UIH(F) Q> 0) C: UIH(F) ... This happens because gsm_control_send() sets cretries timer to T2 that is by default set to 34. This will cause resend for T2 times for the control frame. In ADM mode, we will never get a response so the control frame, so retries are just delaying all the commands. Let's fix the issue by setting DLCI_MODE_ADM flag after detecting the ADM mode for the control DLCI. Then we can use that in gsm_control_send() to set retries to 1. This means the control frame will be sent once allowing the other end at an opportunity to switch from ADM to ABM mode. Note that retries will be decremented in gsm_control_retransmit() so we don't want to set it to 0 here. Fixes: ea3d8465ab9b ("tty: n_gsm: Allow ADM response in addition to UA for control dlci") Cc: linux-serial@vger.kernel.org Cc: Alan Cox <alan@llwyncelyn.cymru> Cc: Dan Williams <dcbw@redhat.com> Cc: Jiri Prchal <jiri.prchal@aksignal.cz> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Marcel Partap <mpartap@gmx.net> Cc: Merlijn Wajer <merlijn@wizzup.org> Cc: Michael Nazzareno Trimarchi <michael@amarulasolutions.com> Cc: Michael Scott <michael.scott@linaro.org> Cc: Pavel Machek <pavel@ucw.cz> Cc: Peter Hurley <peter@hurleysoftware.com> Cc: Russ Gorby <russ.gorby@intel.com> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: Sebastian Reichel <sre@kernel.org> Signed-off-by: Tony Lindgren <tony@atomide.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-09Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Martin Schwidefsky: - Improvements for the spectre defense: * The spectre related code is consolidated to a single file nospec-branch.c * Automatic enable/disable for the spectre v2 defenses (expoline vs. nobp) * Syslog messages for specve v2 are added * Enable CONFIG_GENERIC_CPU_VULNERABILITIES and define the attribute functions for spectre v1 and v2 - Add helper macros for assembler alternatives and use them to shorten the code in entry.S. - Add support for persistent configuration data via the SCLP Store Data interface. The H/W interface requires a page table that uses 4K pages only, the code to setup such an address space is added as well. - Enable virtio GPU emulation in QEMU. To do this the depends statements for a few common Kconfig options are modified. - Add support for format-3 channel path descriptors and add a binary sysfs interface to export the associated utility strings. - Add a sysfs attribute to control the IFCC handling in case of constant channel errors. - The vfio-ccw changes from Cornelia. - Bug fixes and cleanups. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (40 commits) s390/kvm: improve stack frame constants in entry.S s390/lpp: use assembler alternatives for the LPP instruction s390/entry.S: use assembler alternatives s390: add assembler macros for CPU alternatives s390: add sysfs attributes for spectre s390: report spectre mitigation via syslog s390: add automatic detection of the spectre defense s390: move nobp parameter functions to nospec-branch.c s390/cio: add util_string sysfs attribute s390/chsc: query utility strings via fmt3 channel path descriptor s390/cio: rename struct channel_path_desc s390/cio: fix unbind of io_subchannel_driver s390/qdio: split up CCQ handling for EQBS / SQBS s390/qdio: don't retry EQBS after CCQ 96 s390/qdio: restrict buffer merging to eligible devices s390/qdio: don't merge ERROR output buffers s390/qdio: simplify math in get_*_buffer_frontier() s390/decompressor: trim uncompressed image head during the build s390/crypto: Fix kernel crash on aes_s390 module remove. s390/defkeymap: fix global init to zero ...
2018-04-04Merge tag 'tty-4.17-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty/serial driver updates from Greg KH: "Here is the big set of tty and serial driver patches for 4.17-rc1 Not all that big really, most are just small fixes and additions to existing drivers. There's a bunch of work on the imx serial driver recently for some reason, and a new embedded serial driver added as well. Full details are in the shortlog. All of these have been in the linux-next tree for a while with no reported issues" * tag 'tty-4.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (66 commits) serial: expose buf_overrun count through proc interface serial: mvebu-uart: fix tx lost characters tty: serial: msm_geni_serial: Fix return value check in qcom_geni_serial_probe() tty: serial: msm_geni_serial: Add serial driver support for GENI based QUP 8250-men-mcb: add support for 16z025 and 16z057 powerpc: Mark the variable earlycon_acpi_spcr_enable maybe_unused serial: stm32: fix initialization of RS485 mode ARM: dts: STi: Remove "console=ttyASN" from bootargs for STi boards vt: change SGR 21 to follow the standards serdev: Fix typo in serdev_device_alloc ARM: dts: STi: Fix aliases property name for STi boards tty: st-asc: Update tty alias serial: stm32: add support for RS485 hardware control mode dt-bindings: serial: stm32: add RS485 optional properties selftests: add devpts selftests devpts: comment devpts_mntget() devpts: resolve devpts bind-mounts devpts: hoist out check for DEVPTS_SUPER_MAGIC serial: 8250: Add Nuvoton NPCM UART serial: mxs-auart: disable clks of Alphascale ASM9260 ...
2018-04-02Merge branch 'syscalls-next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/brodo/linux Pull removal of in-kernel calls to syscalls from Dominik Brodowski: "System calls are interaction points between userspace and the kernel. Therefore, system call functions such as sys_xyzzy() or compat_sys_xyzzy() should only be called from userspace via the syscall table, but not from elsewhere in the kernel. At least on 64-bit x86, it will likely be a hard requirement from v4.17 onwards to not call system call functions in the kernel: It is better to use use a different calling convention for system calls there, where struct pt_regs is decoded on-the-fly in a syscall wrapper which then hands processing over to the actual syscall function. This means that only those parameters which are actually needed for a specific syscall are passed on during syscall entry, instead of filling in six CPU registers with random user space content all the time (which may cause serious trouble down the call chain). Those x86-specific patches will be pushed through the x86 tree in the near future. Moreover, rules on how data may be accessed may differ between kernel data and user data. This is another reason why calling sys_xyzzy() is generally a bad idea, and -- at most -- acceptable in arch-specific code. This patchset removes all in-kernel calls to syscall functions in the kernel with the exception of arch/. On top of this, it cleans up the three places where many syscalls are referenced or prototyped, namely kernel/sys_ni.c, include/linux/syscalls.h and include/linux/compat.h" * 'syscalls-next' of git://git.kernel.org/pub/scm/linux/kernel/git/brodo/linux: (109 commits) bpf: whitelist all syscalls for error injection kernel/sys_ni: remove {sys_,sys_compat} from cond_syscall definitions kernel/sys_ni: sort cond_syscall() entries syscalls/x86: auto-create compat_sys_*() prototypes syscalls: sort syscall prototypes in include/linux/compat.h net: remove compat_sys_*() prototypes from net/compat.h syscalls: sort syscall prototypes in include/linux/syscalls.h kexec: move sys_kexec_load() prototype to syscalls.h x86/sigreturn: use SYSCALL_DEFINE0 x86: fix sys_sigreturn() return type to be long, not unsigned long x86/ioport: add ksys_ioperm() helper; remove in-kernel calls to sys_ioperm() mm: add ksys_readahead() helper; remove in-kernel calls to sys_readahead() mm: add ksys_mmap_pgoff() helper; remove in-kernel calls to sys_mmap_pgoff() mm: add ksys_fadvise64_64() helper; remove in-kernel call to sys_fadvise64_64() fs: add ksys_fallocate() wrapper; remove in-kernel calls to sys_fallocate() fs: add ksys_p{read,write}64() helpers; remove in-kernel calls to syscalls fs: add ksys_truncate() wrapper; remove in-kernel calls to sys_truncate() fs: add ksys_sync_file_range helper(); remove in-kernel calls to syscall kernel: add ksys_setsid() helper; remove in-kernel call to sys_setsid() kernel: add ksys_unshare() helper; remove in-kernel calls to sys_unshare() ...
2018-04-02Merge tag 'arch-removal' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic Pul removal of obsolete architecture ports from Arnd Bergmann: "This removes the entire architecture code for blackfin, cris, frv, m32r, metag, mn10300, score, and tile, including the associated device drivers. I have been working with the (former) maintainers for each one to ensure that my interpretation was right and the code is definitely unused in mainline kernels. Many had fond memories of working on the respective ports to start with and getting them included in upstream, but also saw no point in keeping the port alive without any users. In the end, it seems that while the eight architectures are extremely different, they all suffered the same fate: There was one company in charge of an SoC line, a CPU microarchitecture and a software ecosystem, which was more costly than licensing newer off-the-shelf CPU cores from a third party (typically ARM, MIPS, or RISC-V). It seems that all the SoC product lines are still around, but have not used the custom CPU architectures for several years at this point. In contrast, CPU instruction sets that remain popular and have actively maintained kernel ports tend to all be used across multiple licensees. [ See the new nds32 port merged in the previous commit for the next generation of "one company in charge of an SoC line, a CPU microarchitecture and a software ecosystem" - Linus ] The removal came out of a discussion that is now documented at https://lwn.net/Articles/748074/. Unlike the original plans, I'm not marking any ports as deprecated but remove them all at once after I made sure that they are all unused. Some architectures (notably tile, mn10300, and blackfin) are still being shipped in products with old kernels, but those products will never be updated to newer kernel releases. After this series, we still have a few architectures without mainline gcc support: - unicore32 and hexagon both have very outdated gcc releases, but the maintainers promised to work on providing something newer. At least in case of hexagon, this will only be llvm, not gcc. - openrisc, risc-v and nds32 are still in the process of finishing their support or getting it added to mainline gcc in the first place. They all have patched gcc-7.3 ports that work to some degree, but complete upstream support won't happen before gcc-8.1. Csky posted their first kernel patch set last week, their situation will be similar [ Palmer Dabbelt points out that RISC-V support is in mainline gcc since gcc-7, although gcc-7.3.0 is the recommended minimum - Linus ]" This really says it all: 2498 files changed, 95 insertions(+), 467668 deletions(-) * tag 'arch-removal' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: (74 commits) MAINTAINERS: UNICORE32: Change email account staging: iio: remove iio-trig-bfin-timer driver tty: hvc: remove tile driver tty: remove bfin_jtag_comm and hvc_bfin_jtag drivers serial: remove tile uart driver serial: remove m32r_sio driver serial: remove blackfin drivers serial: remove cris/etrax uart drivers usb: Remove Blackfin references in USB support usb: isp1362: remove blackfin arch glue usb: musb: remove blackfin port usb: host: remove tilegx platform glue pwm: remove pwm-bfin driver i2c: remove bfin-twi driver spi: remove blackfin related host drivers watchdog: remove bfin_wdt driver can: remove bfin_can driver mmc: remove bfin_sdh driver input: misc: remove blackfin rotary driver input: keyboard: remove bf54x driver ...
2018-04-02x86/ioport: add ksys_ioperm() helper; remove in-kernel calls to sys_ioperm()Dominik Brodowski
Using this helper allows us to avoid the in-kernel calls to the sys_ioperm() syscall. The ksys_ prefix denotes that this function is meant as a drop-in replacement for the syscall. In particular, it uses the same calling convention as sys_ioperm(). This patch is part of a series which removes in-kernel calls to syscalls. On this basis, the syscall entry path can be streamlined. For details, see http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Slaby <jslaby@suse.com> Cc: x86@kernel.org Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2018-04-02fs: add ksys_sync() helper; remove in-kernel calls to sys_sync()Dominik Brodowski
Using this helper allows us to avoid the in-kernel calls to the sys_sync() syscall. The ksys_ prefix denotes that this function is meant as a drop-in replacement for the syscall. In particular, it uses the same calling convention as sys_sync(). This patch is part of a series which removes in-kernel calls to syscalls. On this basis, the syscall entry path can be streamlined. For details, see http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net Cc: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2018-03-26tty: hvc: remove tile driverArnd Bergmann
The Tile architecture is obsolete and getting removed from the kernel, this removes the corresponding console driver as well. Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2018-03-26tty: remove bfin_jtag_comm and hvc_bfin_jtag driversArnd Bergmann
The blackfin architecture is getting removed, so these drivers are not needed any more. Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Aaron Wu <aaron.wu@analog.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2018-03-26serial: remove tile uart driverArnd Bergmann
The tile architecture is getting removed, and this driver is useless without it. Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2018-03-26serial: remove m32r_sio driverArnd Bergmann
The m32r architecture is getting removed, so we don't need this any more. Acked-by: Nicolas Pitre <nico@fluxnic.net> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2018-03-26serial: remove blackfin driversArnd Bergmann
The blackfin architecture is getting removed, so both the bfin_uart and bfin_sport_uart can be removed as well. Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Aaron Wu <aaron.wu@analog.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2018-03-26serial: remove cris/etrax uart driversArnd Bergmann
The cris architecture is getting removed, so we don't need the uart driver any more. Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2018-03-25tty: vt: fix up tabstops properlyLinus Torvalds
Tabs on a console with long lines do not wrap properly, so correctly account for the line length when computing the tab placement location. Reported-by: James Holderness <j4_james@hotmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: stable <stable@vger.kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-03-23serial: expose buf_overrun count through proc interfaceJeremy Kerr
The buf_overrun count is only every written, and not exposed to userspace anywhere. This means that dropped characters due to flip buffer overruns are never visible to userspace. The /proc/tty/driver/serial file exports a bunch of metrics (including hardware overruns) already, so add the buf_overrun (as "bo:") to this file. Signed-off-by: Jeremy Kerr <jk@ozlabs.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-22serial: mvebu-uart: fix tx lost charactersGabriel Matni
Fixes missing characters on kernel console at low baud rates (i.e.9600). The driver should poll TX_RDY or TX_FIFO_EMP instead of TX_EMP to ensure that the transmitter holding register (THR) is ready to receive a new byte. TX_EMP tells us when it is possible to send a break sequence via SND_BRK_SEQ. While this also indicates that both the THR and the TSR are empty, it does not guarantee that a new byte can be written just yet. Fixes: 30530791a7a0 ("serial: mvebu-uart: initial support for Armada-3700 serial port") Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com> Acked-by: Gregory CLEMENT <gregory.clement@bootlin.com> Signed-off-by: Gabriel Matni <gabriel.matni@exfo.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-22tty: serial: msm_geni_serial: Fix return value check in qcom_geni_serial_probe()Wei Yongjun
In case of error, the function platform_get_resource() returns NULL pointer not ERR_PTR(). The IS_ERR() test in the return value check should be replaced with NULL test. Fixes: c4f528795d1a ("tty: serial: msm_geni_serial: Add serial driver support for GENI based QUP") Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-20Merge 4.16-rc6 into tty-nextGreg Kroah-Hartman
We want the serial/tty fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-20tty: serial: msm_geni_serial: Add serial driver support for GENI based QUPKarthikeyan Ramasubramanian
This driver supports GENI based UART Controller in the Qualcomm SOCs. The Qualcomm Generic Interface (GENI) is a programmable module supporting a wide range of serial interfaces including UART. This driver support console operations using FIFO mode of transfer. Signed-off-by: Girish Mahadevan <girishm@codeaurora.org> Signed-off-by: Karthikeyan Ramasubramanian <kramasub@codeaurora.org> Signed-off-by: Sagar Dharia <sdharia@codeaurora.org> Signed-off-by: Doug Anderson <dianders@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-18s390/setup : enable display support for KVM guestFarhan Ali
The S390 architecture does not support any graphics hardware, but with the latest support for Virtio GPU in Linux and Virtio GPU emulation in QEMU, it's possible to enable graphics for S390 using the Virtio GPU device. To enable display we need to enable the Linux Virtual Terminal (VT) layer for S390. But the VT subsystem initializes quite early at boot so we need a dummy console driver till the Virtio GPU driver is initialized and we can run the framebuffer console. The framebuffer console over a Virtio GPU device can be run in combination with the serial SCLP console (default on S390). The SCLP console can still be accessed by management applications (eg: via Libvirt's virsh console). Signed-off-by: Farhan Ali <alifm@linux.vnet.ibm.com> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Thomas Huth <thuth@redhat.com> Message-Id: <e23b61f4f599ba23881727a1e8880e9d60cc6a48.1519315352.git.alifm@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-03-158250-men-mcb: add support for 16z025 and 16z057Michael Moese
Add support for two MEN UARTs (16z025 and 16z057) to the 8250_men_mcb driver. The 16z025 consists of up to four ports, the 16z057 has exactly four ports. Apart from that, all of them share the Port settings. Signed-off-by: Michael Moese <mmoese@suse.de> Reported-by: Ben Turner <ben.turner@21net.com> Tested-by: Ben Turner <ben.turner@21net.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-15serial: stm32: fix initialization of RS485 modeBich HEMON
Configure RS485 mode during port initialization. Fixes: 1bcda09d2910 ("serial: stm32: add support for RS485 hardware control mode") Signed-off-by: Bich Hemon <bich.hemon@st.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-14vt: change SGR 21 to follow the standardsMike Frysinger
ECMA-48 [1] (aka ISO 6429) has defined SGR 21 as "doubly underlined" since at least March 1984. The Linux kernel has treated it as SGR 22 "normal intensity" since it was added in Linux-0.96b in June 1992. Before that, it was simply ignored. Other terminal emulators have either ignored it, or treat it as double underline now. xterm for example added support in its 304 release (May 2014) [2] where it was previously ignoring it. Changing this behavior shouldn't be an issue: - It isn't a named capability in ncurses's terminfo database, so no script is using libtinfo/libcurses to look this up, or using tput to query & output the right sequence. - Any script assuming SGR 21 will reset intensity in all terminals already do not work correctly on non-Linux VTs (including running under screen/tmux/etc...). - If someone has written a script that only runs in the Linux VT, and they're using SGR 21 (instead of SGR 22), the output should still be readable. imo it's important to change this as the Linux VT's non-conformance is sometimes used as an argument for other terminal emulators to not implement SGR 21 at all, or do so incorrectly. [1]: https://www.ecma-international.org/publications/standards/Ecma-048.htm [2]: https://github.com/ThomasDickey/xterm-snapshots/commit/2fd29cb98d214cb536bcafbee00bc73b3f1eeb9d Signed-off-by: Mike Frysinger <vapier@chromium.org> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-14serdev: Fix typo in serdev_device_allocFrédéric Danis
Fix function name in serdev_device_alloc() definition Signed-off-by: Frédéric Danis <frederic.danis.oss@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-14tty: st-asc: Update tty aliasPatrice Chotard
Since dtc v1.4.6-9-gaadd0b65c987, aliases property name must include only lowercase and '-'. After having updated all STi boards serial aliases from "ttyASN" to "serialN", st-asc driver need to be updated accordingly as tty aliases id is retrieved using of_alias_get_id(). Signed-off-by: Patrice Chotard <patrice.chotard@st.com> Reviewed-by: Rob Herring <robh@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-14serial: stm32: add support for RS485 hardware control modeBich HEMON
Implement Driver Enable signal (DE) to activate the transmission mode of the external transceiver. Signed-off-by: Yves Coppeaux <yves.coppeaux@st.com> Signed-off-by: Bich Hemon <bich.hemon@st.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-09serial: 8250: Add Nuvoton NPCM UARTJoel Stanley
The Nuvoton UART is almost compatible with the 8250 driver when probed via the 8250_of driver, however it requires some extra configuration at startup. Reviewed-by: Rob Herring <robh@kernel.org> Signed-off-by: Joel Stanley <joel@jms.id.au> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-09serial: mxs-auart: disable clks of Alphascale ASM9260Alexey Khoroshilov
In case of Alphascale ASM9260 probe() enables s->clk and s->clk_ahb via mxs_get_clks(), but there is no disable of the clocks. The patch adds it to error paths and to mxs_auart_remove(). Found by Linux Driver Verification project (linuxtesting.org). Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru> Fixes: 254da0d753fb ("serial: mxs-auart: add Alphascale ASM9260 support") Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-09serial: 8250_dw: Switch to use acpi_dev_present()Andy Shevchenko
Special settings for APMC0D08 are applied when device is present in the system. To check its presence we may use acpi_dev_present() instead of current open coded variant. Cc: Feng Kan <fkan@apm.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-09serial: imx: consistently use imx_uart_ as prefix for all functionsUwe Kleine-König
Having a fixed prefix helps at several places. It ensures that another driver doesn't use the same function name which confuses the linker and tools like ctags. It simplifies working with function tracing and dynamic printk() support which can filter on function names. And last but not least it helps the human source code reader to understand if a given function belongs to a driver or a more general part of the kernel. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-09serial: imx: don't prepare to send if no data is availableUwe Kleine-König
serial_core might call the .start_tx callback without any data being available to send. In this case return early instead of going through all the setup needed for sending which might include disabling RX in RS485 half-duplex mode. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-09serial: imx: Fix handling of TC irq in combination with DMAUwe Kleine-König
When using RS485 half duplex the Transmitter Complete irq is needed to determine the moment when the transmitter can be disabled. When using DMA this irq must only be enabled when DMA has completed to transfer all data. Otherwise the CPU might busily trigger this irq which is not properly handled and so the also pending irq for the DMA transfer cannot trigger. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-09serial: imx: Also enable the aging timer in PIO modeUwe Kleine-König
This allows to increase the RX waterlevel which allows to delay the RRDY irq. The desired effect is that less irqs are needed to handle characters and so reduce irq count of the system. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-09serial: imx: ensure that RX irqs are off if RX is offUwe Kleine-König
Make sure that UCR1.RXDMAEN and UCR1.ATDMAEN (for the DMA case) and UCR1.RRDYEN (for the PIO case) are off iff UCR1.RXEN is disabled. This ensures that the fifo isn't read with RX disabled which results in an exception. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-09serial: imx: Stop to receive in .stop_rx()Uwe Kleine-König
When the UART is used in DMA mode, .stop_rx() does nothing if the port isn't suspended. This is wrong as .stop_rx() should stop receiving characters unconditionally. When the port is about to be closed the DMA channel is stopped in .shutdown(), so this isn't necessary to be in .stop_rx() here, too. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-09serial: imx: setup fifo waterlevel before enabling aging timerUwe Kleine-König
The aging timer fires if there are characters in the RX fifo but the water level isn't reached yet. Make sure that the waterlevel is configured before the aging timer is enabled to trigger a DMA request (UCR1_ATDMAEN). Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-09serial: imx: use u32 variables with matching names for registersUwe Kleine-König
The serial/imx driver is full of inconsistently named and typed variables that hold different register values. Consistently use u32 as type (matching what readl and writel use) and name the variables after the register whose value they are holding. This makes it easier to notice when UCR2_RTSEN is written to UCR1. The only difference introduced by this commit in the compiled driver is that twice the second argument to warn_slowpath_null() changed because the two WARN_ON in dma_rx_callback() pass __LINE__ to warn_slowpath_null(). Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-09serial: imx: simplify check that prevents starting PIO when DMA is in useUwe Kleine-König
The original code looks as follows: if (sport->dma_is_enabled) { ... make sure TX DMA is running, i.e. .dma_is_txing = 1 } if (sport->dma_is_txing) return; As .dma_is_txing can only be true if .dma_is_enabled is, the return can go at the end of the first if body without an additional check. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-09serial: imx: simplify some conditions related to dmaUwe Kleine-König
Neither .dma_is_txing nor .dma_is_rxing can evaluate to true if .dma_is_enabled evaluates to false: The only function that sets .dma_is_txing to a non-zero value is imx_dma_tx() which is only called if .dma_is_enabled is true. Same for .dma_is_rxing and start_rx_dma(). And before .dma_is_enabled is set to 0 when imx_shutdown calls imx_disable_dma(), .dma_is_rxing and .dma_is_txing are reset to zero before, too. For this reason sport->dma_is_enabled && sport->dma_is_rxing has the same value as sport->dma_is_rxing which allows to simplify three if conditions. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-09serial: imx: implement shadow registers for UCRx and UFCRUwe Kleine-König
This reduces the amount of read accesses to the register space by shadowing the values for five registers that only change on writing them. There is a single bit in UCR2 that might change without being written to it, this is handled accordingly. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>