reenable_fd has been a NOP since the introduction of the EPOLL
based interrupt controller.
reenable_channel() is no longer needed as the flow control is
now handled via the write IRQs on the channel.
Signed-off-by: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
This fixes a long standing bug where large amounts of output
could freeze the tty (most commonly seen on stdio console).
While the bug has always been there it became more pronounced
after moving to the new interrupt controller.
The line semantics are now changed to have true IRQ write
semantics which should further improve the tty/line subsystem
stability and performance
Signed-off-by: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
1. Removes the need to walk the IRQ/Device list to determine
who triggered the IRQ.
2. Improves scalability (up to several times performance
improvement for cases with 10s of devices).
3. Improves UML baseline IO performance for one disk + one NIC
use case by up to 10%.
4. Introduces write poll triggered IRQs.
5. Prerequisite for introducing high performance mmesg family
of functions in network IO.
6. Fixes RNG shutdown which was leaking a file descriptor
Signed-off-by: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
We are going to split <linux/sched/signal.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.
Create a trivial placeholder <linux/sched/signal.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.
Include the new header in the files that are going to need it.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Although the tty core maintains a pid reference for the foreground
process group, if the foreground process group is changed that
pid reference is dropped. Thus, the pid reference used for signalling
could become stale.
Safely obtain a pid reference to the foreground process group and
release the reference after signalling is complete.
cc: Jeff Dike <jdike@addtoit.com>
Acked-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Reviewed-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
It allows for cleaning up on a considerable amount of places. They did
port_get, wakeup, kref_put. Now the only thing needed is to call
tty_port_tty_wakeup which does exactly that.
One exception is ifx6x60 where tty_wakeup was open-coded. We now call
tty_wakeup properly there.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The tty below tty_port might get destroyed by the tty layer
while we hold a reference to it.
So we have to carry tty_port around...
Signed-off-by: Richard Weinberger <richard@nod.at>
As we setup the SIGWINCH handler in tty_port_operations->activate
it makes sense to tear down it in ->destruct.
Signed-off-by: Richard Weinberger <richard@nod.at>
Now, we start converting tty buffer functions to actually use
tty_port. This will allow us to get rid of the need of tty in many
call sites. Only tty_port will needed and hence no more
tty_port_tty_get in those paths.
Now, the one where most of tty_port_tty_get gets removed:
tty_flip_buffer_push.
IOW we also closed all the races in drivers not using tty_port_tty_get
at all yet.
Also we move tty_flip_buffer_push declaration from include/linux/tty.h
to include/linux/tty_flip.h to all others while we are changing it
anyway.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
After commit "TTY: move tty buffers to tty_port", the tty buffers are
not freed in some drivers. This is because tty_port_destructor is not
called whenever a tty_port is freed. This was an assumption I counted
with but was unfortunately untrue. So fix the drivers to fulfil this
assumption.
To be sure, the TTY buffers (and later some stuff) are gone along with
the tty_port, we have to call tty_port_destroy at tear-down places.
This is mostly where the structure containing a tty_port is freed.
This patch does exactly that -- put tty_port_destroy at those places.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull UML changes from Richard Weinberger:
"UML receives this time only cleanups.
The most outstanding change is the 'include "foo.h"' do 'include
<foo.h>' conversion done by Al Viro.
It touches many files, that's why the diffstat is rather big."
* 'for-linus-37rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
typo in UserModeLinux-HOWTO
hppfs: fix the return value of get_inode()
hostfs: drop vmtruncate
um: get rid of pointless include "..." where include <...> will do
um: move sysrq.h out of include/shared
um/x86: merge 32 and 64 bit variants of ptrace.h
um/x86: merge 32 and 64bit variants of checksum.h
Currently we have no way to assign tty->port while performing tty
installation. There are two ways to provide the link tty_struct =>
tty_port. Either by calling tty_port_install from tty->ops->install or
tty_port_register_device called instead of tty_register_device when
the device is being set up after connected.
In this patch we modify most of the drivers to do the latter. When the
drivers use tty_register_device and we have tty_port already, we
switch to tty_port_register_device. So we have the tty_struct =>
tty_port link for free for those.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull UML fixes from Richard Weinberger:
"This patch set contains mostly fixes and cleanups. The UML tty driver
uses now tty_port and is no longer broken like hell :-)"
* 'for-linus-3.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
um: Add arch/x86/um to MAINTAINERS
um: pass siginfo to guest process
um: fix ubd_file_size for read-only files
um: pull interrupt_end() into userspace()
um: split syscall_trace(), pass pt_regs to it
um: switch UPT_SET_RETURN_VALUE and regs_return_value to pt_regs
um: set BLK_CGROUP=y in defconfig
um: remove count_lock
um: fully use tty_port
um: Remove dead code
um: remove line_ioctl()
TTY: um/line, use tty from tty_port
TTY: um/line, add tty_port
This means switching to the tty refcounted model so that we will not
race with interrupts.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: user-mode-linux-devel@lists.sourceforge.net
Signed-off-by: Richard Weinberger <richard@nod.at>
And use count from there.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: user-mode-linux-devel@lists.sourceforge.net
Signed-off-by: Richard Weinberger <richard@nod.at>
With the changes in the random tree, IRQF_SAMPLE_RANDOM is now a
no-op; interrupt randomness is now collected unconditionally in a very
low-overhead fashion; see commit 775f4b297b. The IRQF_SAMPLE_RANDOM
flag was scheduled to be removed in 2009 on the
feature-removal-schedule, so this patch is preparation for the final
removal of this flag.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Instead of using chip->release() we can achieve the same
using a simple wrapper for free_irq().
We have already um_request_irq(), so um_free_irq() is the perfect
counterpart.
Signed-off-by: Richard Weinberger <richard@nod.at>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
... and switch chan_interrupt() to directly calling close_one_chan(),
so we can lose delay_free_irq argument of close_chan() as well.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
... since chan_interrupt() might schedule it if there's too much
incoming data. Kill task argument of chan_interrupt(), while
we are at it - it's always &line->task.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
move config-independent parts of initialization into
register_lines(), call setup_one_line() after it instead
of abusing ->init_str.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
Current code doesn't update the symlinks in /sys/dev/char when we add/remove
tty lines. Fixing that allows to stop messing with ->valid before the driver
registration, which is a Good Thing(tm) - we shouldn't have it set before we
really have the things set up and ready for line_open().
We need tty_driver available to call tty_{un,}register_device(), so we just
stash a reference to it into struct line_driver.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
Pull parse_chan_pair() call into setup_one_line(), under the mutex.
We really don't want open() to succeed before parse_chan_pair() had
been done (or after it has failed, BTW). We also want "remove con<n>"
to free irqs, etc., same as "config con<n>=none".
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
If two processes are opening the same line, the second to get
into line_open() will decide that it doesn't need to do anything
(correctly) or wait for anything. The latter, unfortunately,
is incorrect - the first opener might not be through yet. We
need to have exclusion covering the entire line_init(), including
the blocking parts. Moreover, the next patch will need to
widen the exclusion on mconsole side of things, also including
the blocking bits, so let's just convert that sucker to mutex...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
make line_setup() act on a separate array of conf strings + default conf,
have lines array initialized explicitly by that data, bury LINE_INIT()
macro from hell.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
Since commit [e58aa3d2: genirq: Run irq handlers with interrupts disabled],
We run all interrupt handlers with interrupts disabled
and we even check and yell when an interrupt handler
returns with interrupts enabled (see commit [b738a50a:
genirq: Warn when handler enables interrupts]).
So now this flag is a NOOP and can be removed.
Signed-off-by: Yong Zhang <yong.zhang0@gmail.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
while not doing free_irq() from irq handler is commendable, kfree() on the
data passed to said handler before free_irq() is Not Good(tm). Freeing
the stack it's being run on is also not nice... Solution: delay actually
freeing stuff.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
... so set winch->fd to -1 before doing free_irq(), to avoid having
winch_interrupt() come from/during the latter and attempt to do
reactivate_fd() on something that's already gone.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
tty->count is decremented only after ->close() had been called and
several tasks can hit it in parallel. As the result, using tty->count
to check if you are the last one is broken. We end up leaving line->tty
not reset to NULL and the next IRQ on that sucker will blow up trying to
dereference pointers from kfree'd struct tty.
Fix is obvious: we need to use a counter of our own.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
GCC 4.6's -Wunused-but-set-variable found some dead code.
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 6caa76b ("tty: now phase out the ioctl file pointer for good")
removed the ioctl file pointer. User Mode Linux's line driver uses this
ioctl and needs a signature update too.
Signed-off-by: Richard Weinberger <richard@nod.at>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Greg KH <greg@kroah.com>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
unregister_winch() should use list_for_each_safe(), as it can delete from
the list.
Signed-off-by: Will Newton <will.newton@gmail.com>
Cc: richard -rw- weinberger <richard.weinberger@gmail.com>
Acked-by: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Disable the winch irq early to make sure we don't take an interrupt part
way through the freeing of the handler data, resulting in a crash on
shutdown:
winch_interrupt : read failed, errno = 9
fd 13 is losing SIGWINCH support
------------[ cut here ]------------
WARNING: at lib/list_debug.c:48 list_del+0xc6/0x100()
list_del corruption, next is LIST_POISON1 (00100100)
082578c8: [<081fd77f>] dump_stack+0x22/0x24
082578e0: [<0807a18a>] warn_slowpath_common+0x5a/0x80
08257908: [<0807a23e>] warn_slowpath_fmt+0x2e/0x30
08257920: [<08172196>] list_del+0xc6/0x100
08257940: [<08060244>] free_winch+0x14/0x80
08257958: [<080606fb>] winch_interrupt+0xdb/0xe0
08257978: [<080a65b5>] handle_IRQ_event+0x35/0xe0
08257998: [<080a8717>] handle_edge_irq+0xb7/0x170
082579bc: [<08059bc4>] do_IRQ+0x34/0x50
082579d4: [<08059e1b>] sigio_handler+0x5b/0x80
082579ec: [<0806a374>] sig_handler_common+0x44/0xb0
08257a68: [<0806a538>] sig_handler+0x38/0x50
08257a78: [<0806a77c>] handle_signal+0x5c/0xa0
08257a9c: [<0806be28>] hard_handler+0x18/0x20
08257aac: [<00c14400>] 0xc14400
Signed-off-by: Will Newton <will.newton@gmail.com>
Acked-by: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (44 commits)
vlynq: make whole Kconfig-menu dependant on architecture
add descriptive comment for TIF_MEMDIE task flag declaration.
EEPROM: max6875: Header file cleanup
EEPROM: 93cx6: Header file cleanup
EEPROM: Header file cleanup
agp: use NULL instead of 0 when pointer is needed
rtc-v3020: make bitfield unsigned
PCI: make bitfield unsigned
jbd2: use NULL instead of 0 when pointer is needed
cciss: fix shadows sparse warning
doc: inode uses a mutex instead of a semaphore.
uml: i386: Avoid redefinition of NR_syscalls
fix "seperate" typos in comments
cocbalt_lcdfb: correct sections
doc: Change urls for sparse
Powerpc: wii: Fix typo in comment
i2o: cleanup some exit paths
Documentation/: it's -> its where appropriate
UML: Fix compiler warning due to missing task_struct declaration
UML: add kernel.h include to signal.c
...
We now have to to include linux/slab.h explicitly for kmalloc &
friends. Files that build against host headers already get their
prototypes via um_malloc.h, linux/slab.h may even be unavailable.
Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: Tejun Heo <tj@kernel.org>
Assign tty only if line is not NULL.
[akpm@linux-foundation.org: simplification]
Signed-off-by: Alexander Beregalov <a.beregalov@gmail.com>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
After m68k's task_thread_info() doesn't refer to current,
it's possible to remove sched.h from interrupt.h and not break m68k!
Many thanks to Heiko Carstens for allowing this.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Anton Ivanov