The /dev/ptmx device node is changed to lookup the directory entry "pts"
in the same directory as the /dev/ptmx device node was opened in. If
there is a "pts" entry and that entry is a devpts filesystem /dev/ptmx
uses that filesystem. Otherwise the open of /dev/ptmx fails.
The DEVPTS_MULTIPLE_INSTANCES configuration option is removed, so that
userspace can now safely depend on each mount of devpts creating a new
instance of the filesystem.
Each mount of devpts is now a separate and equal filesystem.
Reserved ttys are now available to all instances of devpts where the
mounter is in the initial mount namespace.
A new vfs helper path_pts is introduced that finds a directory entry
named "pts" in the directory of the passed in path, and changes the
passed in path to point to it. The helper path_pts uses a function
path_parent_directory that was factored out of follow_dotdot.
In the implementation of devpts:
- devpts_mnt is killed as it is no longer meaningful if all mounts of
devpts are equal.
- pts_sb_from_inode is replaced by just inode->i_sb as all cached
inodes in the tty layer are now from the devpts filesystem.
- devpts_add_ref is rolled into the new function devpts_ptmx. And the
unnecessary inode hold is removed.
- devpts_del_ref is renamed devpts_release and reduced to just a
deacrivate_super.
- The newinstance mount option continues to be accepted but is now
ignored.
In devpts_fs.h definitions for when !CONFIG_UNIX98_PTYS are removed as
they are never used.
Documentation/filesystems/devices.txt is updated to describe the current
situation.
This has been verified to work properly on openwrt-15.05, centos5,
centos6, centos7, debian-6.0.2, debian-7.9, debian-8.2, ubuntu-14.04.3,
ubuntu-15.10, fedora23, magia-5, mint-17.3, opensuse-42.1,
slackware-14.1, gentoo-20151225 (13.0?), archlinux-2015-12-01. With the
caveat that on centos6 and on slackware-14.1 that there wind up being
two instances of the devpts filesystem mounted on /dev/pts, the lower
copy does not end up getting used.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Greg KH <greg@kroah.com>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: Peter Anvin <hpa@zytor.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Serge Hallyn <serge.hallyn@ubuntu.com>
Cc: Willy Tarreau <w@1wt.eu>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>
Cc: Jann Horn <jann@thejh.net>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Florian Weimer <fw@deneb.enyo.de>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When CONFIG_PCI is not set, enabling CONFIG_CYZ_INTR has no
practical effect other than generating a warning about an
unused function:
drivers/tty/cyclades.c:1184:20: warning: 'cyz_interrupt' defined but not used [-Wunused-function]
static irqreturn_t cyz_interrupt(int irq, void *dev_id)
This adds a dependency to avoid that warning.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Implement KGDB IO operations for MIPS Fast Debug Channel (FDC). This can
be enabled via Kconfig, which also allows the channel number to be
chosen.
The magic sysrq hack is implemented in the TTY driver, detecting just ^C
for the KGDB channel, and ^O followed by a letter for the FDC console
channel.
The KGDB operations are reasonably efficient thanks to the flush
callback, with a 4 byte buffer being used in both directions to allow up
to 4 bytes to be encoded per FDC word. Reading of data for KGDB will
discard any data received on other channels, which clearly isn't ideal,
but given that there is a single FIFO shared between channels we can't
do much better.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: linux-mips@linux-mips.org
Cc: kgdb-bugreport@lists.sourceforge.net
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/9147/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Add support for early console of MIPS Fast Debug Channel (FDC) on
channel 1 with a call very early from the MIPS setup_arch().
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/9145/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Add TTY driver and consoles for the MIPS EJTAG Fast Debug Channel (FDC),
which is found on the per-CPU MIPS Common Device Mapped Memory (CDMM)
bus.
The FDC is a per-CPU device which is used to communicate with an EJTAG
probe. RX and TX FIFOs exist, containing 32-bits of data and 4-bit
channel numbers. 16 general data streams are implemented on this for TTY
and console use by encoding up to 4 bytes on each 32-bit FDC word.
The TTY devices are named e.g. /dev/ttyFDC3c2 for channel 2 of the FDC
attached to logical CPU 3.
These can be used for getting the kernel log, a login prompt, or as a
GDB remote transport, all over EJTAG and without needing a serial port.
It can have an interrupt to notify of when incoming data is available in
the RX FIFO or when the TX FIFO is no longer full. The detection of this
interrupt occurs in architecture / platform code, but it may be shared
with the timer and/or performance counter interrupt.
Due to the per-CPU nature of the hardware, all outgoing TTY data is
written out from a kthread which is pinned to the appropriate CPU.
The console is not bound to a specific CPU, so output will appear on the
chosen channel on whichever CPU the code is executing on. Enable with
e.g. console=fdc1 in kernel arguments. /dev/console is bound to the same
channel on the boot CPU's FDC if it exists.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/9146/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
ehv_bytechan is marked tristate but fails to build as a module:
drivers/tty/ehv_bytechan.c:363:1: error: type defaults to ‘int’ in declaration of ‘console_initcall’ [-Werror=implicit-int]
It doesn't make much sense for a console driver to be built as
a module, so change it to a bool.
Signed-off-by: Anton Blanchard <anton@samba.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Scott Wood <scottwood@freescale.com>
Add a TTY driver for communicating over a Meta DA (Debug Adapter)
channel using the bios channel SWITCH operation.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This provides a console driver for the Goldfish virtual platform. The original
is from Arve with changes from Jun Nakajima and Tom Keel. This has been then
been ported to the current kernel and to the tty port mechanism by Alan Cox.
In the process it gained proper POSIX semantics and vhangup works. The default
name is not ttyS as this belongs to the 8250 driver. Instead ttyGFx is now used.
In the normal usage case the first port serves as a kernel logging console and
the second one carries various other data streams for the emulation.
Signed-off-by: Arve Hjønnevåg <arve@google.com>
[Cleaned up to handle x86]
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Signed-off-by: Xiaohui Xin <xiaohui.xin@intel.com>
Signed-off-by: Jun Nakajima <jun.nakajima@intel.com>
Signed-off-by: Bruce Beare <bruce.j.beare@intel.com>
[Moved to 3.7 and chunks rewritten to use tty_port layer]
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The option allows you to remove TTY and compile without errors. This
saves space on systems that won't support TTY interfaces anyway.
bloat-o-meter output is below.
The bulk of this patch consists of Kconfig changes adding "depends on
TTY" to various serial devices and similar drivers that require the TTY
layer. Ideally, these dependencies would occur on a common intermediate
symbol such as SERIO, but most drivers "select SERIO" rather than
"depends on SERIO", and "select" does not respect dependencies.
bloat-o-meter output comparing our previous minimal to new minimal by
removing TTY. The list is filtered to not show removed entries with awk
'$3 != "-"' as the list was very long.
add/remove: 0/226 grow/shrink: 2/14 up/down: 6/-35356 (-35350)
function old new delta
chr_dev_init 166 170 +4
allow_signal 80 82 +2
static.__warned 143 142 -1
disallow_signal 63 62 -1
__set_special_pids 95 94 -1
unregister_console 126 121 -5
start_kernel 546 541 -5
register_console 593 588 -5
copy_from_user 45 40 -5
sys_setsid 128 120 -8
sys_vhangup 32 19 -13
do_exit 1543 1526 -17
bitmap_zero 60 40 -20
arch_local_irq_save 137 117 -20
release_task 674 652 -22
static.spin_unlock_irqrestore 308 260 -48
Signed-off-by: Joe Millenbach <jmillenbach@gmail.com>
Reviewed-by: Jamey Sharp <jamey@minilop.net>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Alan says these are not production ready, and users should be told this,
so put the "(EXPERIMENTAL)" marking back in the Kconfig entry string.
Reported-by: Alan Cox <alan@linux.intel.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
As discussed at the kernel summit this year, CONFIG_EXPERIMENTAL means
nothing, so let's get rid of it.
Cc: Kees Cook <keescook@chromium.org>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* 'for-linus' of git://github.com/richardweinberger/linux: (90 commits)
um: fix ubd cow size
um: Fix kmalloc argument order in um/vdso/vma.c
um: switch to use of drivers/Kconfig
UserModeLinux-HOWTO.txt: fix a typo
UserModeLinux-HOWTO.txt: remove ^H characters
um: we need sys/user.h only on i386
um: merge delay_{32,64}.c
um: distribute exports to where exported stuff is defined
um: kill system-um.h
um: generic ftrace.h will do...
um: segment.h is x86-only and needed only there
um: asm/pda.h is not needed anymore
um: hw_irq.h can go generic as well
um: switch to generic-y
um: clean Kconfig up a bit
um: a couple of missing dependencies...
um: kill useless argument of free_chan() and free_one_chan()
um: unify ptrace_user.h
um: unify KSTK_...
um: fix gcov build breakage
...
* 'tty-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (79 commits)
TTY: serial_core: Fix crash if DCD drop during suspend
tty/serial: atmel_serial: bootconsole removed from auto-enumerates
Revert "TTY: call tty_driver_lookup_tty unconditionally"
tty/serial: atmel_serial: add device tree support
tty/serial: atmel_serial: auto-enumerate ports
tty/serial: atmel_serial: whitespace and braces modifications
tty/serial: atmel_serial: change platform_data variable name
tty/serial: RS485 bindings for device tree
TTY: call tty_driver_lookup_tty unconditionally
TTY: pty, release tty in all ptmx_open fail paths
TTY: make tty_add_file non-failing
TTY: drop driver reference in tty_open fail path
8250_pci: Fix kernel panic when pch_uart is disabled
h8300: drivers/serial/Kconfig was moved
parport_pc: release IO region properly if unsupported ITE887x card is found
tty: Support compat_ioctl get/set termios_locked
hvc_console: display printk messages on console.
TTY: snyclinkmp: forever loop in tx_load_dma_buffer()
tty/n_gsm: avoid fifo overflow in gsm_dlci_data_output
tty/n_gsm: fix a bug in gsm_dlci_data_output (adaption = 2 case)
...
Fix up Conflicts in:
- drivers/tty/serial/8250_pci.c
Trivial conflict with removed duplicate device ID
- drivers/tty/serial/atmel_serial.c
Annoying silly conflict between "specify the port num via
platform_data" and other changes to atmel_console_init
* 'pm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (63 commits)
PM / Clocks: Remove redundant NULL checks before kfree()
PM / Documentation: Update docs about suspend and CPU hotplug
ACPI / PM: Add Sony VGN-FW21E to nonvs blacklist.
ARM: mach-shmobile: sh7372 A4R support (v4)
ARM: mach-shmobile: sh7372 A3SP support (v4)
PM / Sleep: Mark devices involved in wakeup signaling during suspend
PM / Hibernate: Improve performance of LZO/plain hibernation, checksum image
PM / Hibernate: Do not initialize static and extern variables to 0
PM / Freezer: Make fake_signal_wake_up() wake TASK_KILLABLE tasks too
PM / Hibernate: Add resumedelay kernel param in addition to resumewait
MAINTAINERS: Update linux-pm list address
PM / ACPI: Blacklist Vaio VGN-FW520F machine known to require acpi_sleep=nonvs
PM / ACPI: Blacklist Sony Vaio known to require acpi_sleep=nonvs
PM / Hibernate: Add resumewait param to support MMC-like devices as resume file
PM / Hibernate: Fix typo in a kerneldoc comment
PM / Hibernate: Freeze kernel threads after preallocating memory
PM: Update the policy on default wakeup settings
PM / VT: Cleanup #if defined uglyness and fix compile error
PM / Suspend: Off by one in pm_suspend()
PM / Hibernate: Include storage keys in hibernation image on s390
...
Introduce the config option CONFIG_VT_CONSOLE_SLEEP in order to cleanup
the #if defined ugliness for the vt suspend support functions. Note that
CONFIG_VT_CONSOLE is already dependant on CONFIG_VT.
The function pm_set_vt_switch is actually dependant on CONFIG_VT and not
CONFIG_PM_SLEEP. This fixes a compile error when CONFIG_PM_SLEEP is
not set:
drivers/tty/vt/vt_ioctl.c:1794: error: redefinition of 'pm_set_vt_switch'
include/linux/suspend.h:17: error: previous definition of 'pm_set_vt_switch' was here
Also, remove the incorrect path from the comment in console.c.
[rjw: Replaced #if defined() with #ifdef in suspend.h.]
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
HW_CONSOLE doesn't need to depend on both VT and !S390 as VT already
depends on !S390.
Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
The ePAPR embedded hypervisor specification provides an API for "byte
channels", which are serial-like virtual devices for sending and receiving
streams of bytes. This driver provides Linux kernel support for byte
channels via three distinct interfaces:
1) An early-console (udbg) driver. This provides early console output
through a byte channel. The byte channel handle must be specified in a
Kconfig option.
2) A normal console driver. Output is sent to the byte channel designated
for stdout in the device tree. The console driver is for handling kernel
printk calls.
3) A tty driver, which is used to handle user-space input and output. The
byte channel used for the console is designated as the default tty.
Signed-off-by: Timur Tabi <timur@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The n_tracerouter and n_tracesink line discpline drivers use the
Linux tty line discpline framework to route trace data coming
from a tty port (say UART for example) to the trace sink line
discipline driver and to another tty port(say USB). Those
these two line discipline drivers can be used together,
independently from pti.c, they are part of the original
implementation solution of the MIPI P1149.7, compact JTAG, PTI
solution for Intel mobile platforms starting with the
Medfield platform.
Signed-off-by: J Freyensee <james_p_freyensee@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
As planned by Arnd Bergmann, this moves the following drivers from
drivers/char/ to drivers/tty/ as that's where they really belong:
amiserial
nozomi
synclink
rocket
cyclades
moxa
mxser
isicom
bfin_jtag_comm
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The Kconfig options for the drivers/tty/ files still were hanging around
in the "big" drivers/char/Kconfig file, so move them to the proper
location under drivers/tty and drivers/tty/hvc/
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Eric W. Biederman