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>
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>
/home/wangcong/Projects/linux-2.6/arch/um/drivers/line.c: In function `line_write_interrupt':
/home/wangcong/Projects/linux-2.6/arch/um/drivers/line.c:366: error: `struct tty_ldisc' has no member named `write_wakeup'
/home/wangcong/Projects/linux-2.6/arch/um/drivers/line.c:367: error: `struct tty_ldisc' has no member named `write_wakeup'
Signed-off-by: WANG Cong <wangcong@zeuux.org>
Cc: Jeff Dike <jdike@addtoit.com>
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
'put_char' of 'struct tty_operations' has changed from 'void' into 'int'.
This can also shut up compiler warnings.
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: WANG Cong <wangcong@zeuux.org>
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
__FUNCTION__ is gcc-specific, use __func__
Signed-off-by: Harvey Harrison <harvey.harrison@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>
A couple more DEBUG_SHIRQ fixes.
The previous mconsole blocking fix exposed the lack of O_NONBLOCK on the
mconsole socket.
Also, winch_interrupt started crashing because it is called at irq free time
and it tries to dereference tty->driver_data, which has already been set to
NULL.
I added some error cleanup in mconsole_init while I was there.
Cc: "Karol Swietlicki" <magotari@gmail.com>
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Tidy kern_util.h. It turns out that most of the function declarations
aren't used, so they can go away. os.h no longer includes
kern_util.h, so files which got it through os.h now need to include it
directly. A number of other files never needed it, so these includes
are deleted.
The structure which was used to pass signal handlers from the kernel
side to the userspace side is gone. Instead, the handlers are
declared here, and used directly from libc code. This allows
arch/um/os-Linux/trap.c to be deleted, with its remnants being moved
to arch/um/os-Linux/skas/trap.c.
arch/um/os-Linux/tty.c had its inclusions changed, and it needed some
style attention, so it got tidied.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Console driver cleanups -
Changed an instance of foo = bar + foo to foo += bar
Removed checks of tty->stopped - I don't think the low-level
driver has any business looking at that
Removed an annoying warning
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Spelling fixes in arch/um/.
Signed-off-by: Simon Arlott <simon@fire.lp0.eu>
Acked-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Tidy line.c:
The includes are more minimal
Lots of style fixes
All the printks have severities
Removed some commented-out code
Deleted a useless printk when ioctl is called
Fixed some whitespace damage
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The previous console cleanup patch switched generic_read and generic_write
from calling os_{read,write}_file to calling read and write directly. Because
the calling convention is different, they now need to get any error from errno
rather than the return value. I did this for generic_read, but forgot about
generic_write.
While chasing some output corruption, I noticed that line_write was
unnecessarily calling flush_buffer, and deleted it. I don't understand why,
but the corruption disappeared. This is unneeded because there already is a
perfectly good mechanism for finding out when the host output device has some
room to write data - there is an interrupt that comes in when writes can
happen again. line_write calling flush_buffer seemed to just be an attempt to
opportunistically get some data out to the host.
I also made write_chan short-circuit calling into the host-level code for
zero-length writes. Calling libc write with a length of zero conflated write
not being able to write anything with asking it not to write anything. Better
to just cut it off as soon as possible.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cleanup of the SIGWINCH support.
Some code and comment reformatting.
The stack used for SIGWINCH threads was leaked. This is now fixed by storing
it with the pid and other information, and freeing it when the thread is
killed.
If something goes wrong with a WIGWINCH thread, and this is discovered in the
interrupt handler, the winch record would leak. It is now freed, except that
the IRQ isn't freed. This is hard to do from interrupt context. This has the
side-effect that the IRQ system maintains a reference to the freed structure,
but that shouldn't cause a problem since the descriptor is disabled.
register_winch_irq is now much better about cleaning up after an
initialization failure.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If the host side of a console can't be opened, this will now produce visible
error messages.
enable_chan now returns a status and this is passed up to con_open and
ssl_open, which will complain if anything went wrong.
The default host device for the serial line driver is now a pts device rather
than a pty device since lots of hosts have LEGACY_PTYS disabled. This had
always been failing on such hosts, but silently.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Include linux/kernel.h wherever simple_strtoul is used. This kills a
compile warning in stderr_console.c and potential ones in the other files.
This also fixes a bunch of style violations in exitcode.c.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
user_util.h isn't needed any more, so delete it and remove all includes of it.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix confusion about call context - comments and code are inconsistent and
plain wrong, my fault.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Acked-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Of kernel subsystems that work with pids the tty layer is probably the largest
consumer. But it has the nice virtue that the assiation with a session only
lasts until the session leader exits. Which means that no reference counting
is required. So using struct pid winds up being a simple optimization to
avoid hash table lookups.
In the long term the use of pid_nr also ensures that when we have multiple pid
spaces mixed everything will work correctly.
Signed-off-by: Eric W. Biederman <eric@maxwell.lnxi.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Eliminate the open_mutex after complaints from Blaisorblade. It turns out
that the tty count provides the information needed to tell whether we are the
first opener or last closer.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove the last vestiges of devfs from console registration. Change the name
of the function, plus remove a couple of unused fields from the line_driver
structure.
struct lines is no longer needed, all traces of it are gone.
The only way that I can see to mark a structure as being almost-const is to
individually const the fields. This is the case for the line_driver
structure, which has only one modifiable field - a list_head in a
sub-structure.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I noticed that errors happening while hotplugging devices from the host were
never returned back to the mconsole client. In some cases, success was
returned instead of even an information-free error.
This patch cleans that up by having the low-level configuration code pass back
an error string along with an error code. At the top level, which knows
whether it is early boot time or responding to an mconsole request, the string
is printk'd or returned to the mconsole client.
There are also whitespace and trivial code cleanups in the surrounding code.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Clean up the console driver locking. There are various problems here,
including sleeping under a spinlock and spinlock recursion, some of which are
fixed here. This patch deals with the locking involved with opens and closes.
The problem is that an mconsole request to change a console's configuration
can race with an open. Changing a configuration should only be done when a
console isn't opened. Also, an open must be looking at a stable
configuration. In addition, a get configuration request must observe the same
locking since it must also see a stable configuration. With the old locking,
it was possible for this to hang indefinitely in some cases because open would
block for a long time waiting for a connection from the host while holding the
lock needed by the mconsole request.
As explained in the long comment, this is fixed by adding a spinlock for the
use count and configuration and a mutex for the actual open and close.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is the grungy swap all the occurrences in the right places patch that
goes with the updates. At this point we have the same functionality as
before (except that sgttyb() returns speeds not zero) and are ready to
begin turning new stuff on providing nobody reports lots of bugs
If you are a tty driver author converting an out of tree driver the only
impact should be termios->ktermios name changes for the speed/property
setting functions from your upper layers.
If you are implementing your own TCGETS function before then your driver
was broken already and its about to get a whole lot more painful for you so
please fix it 8)
Also fill in c_ispeed/ospeed on init for most devices, although the current
code will do this for you anyway but I'd like eventually to lose that extra
paranoia
[akpm@osdl.org: bluetooth fix]
[mp3@de.ibm.com: sclp fix]
[mp3@de.ibm.com: warning fix for tty3270]
[hugh@veritas.com: fix tty_ioctl powerpc build]
[jdike@addtoit.com: uml: fix ->set_termios declaration]
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Martin Peschke <mp3@de.ibm.com>
Acked-by: Peter Oberparleiter <oberpar@de.ibm.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
