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>

This reverts commit 616c310e.
(Move PREEMPT_RCU preemption to switch_to() invocation).
Testing by Sasha Levin <levinsasha928@gmail.com> showed that this
can result in deadlock due to invoking the scheduler when one of
the runqueue locks is held.  Because this commit was simply a
performance optimization, revert it.

Reported-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Sasha Levin <levinsasha928@gmail.com>

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>

Currently, PREEMPT_RCU readers are enqueued upon entry to the scheduler.
This is inefficient because enqueuing is required only if there is a
context switch, and entry to the scheduler does not guarantee a context
switch.

The commit therefore moves the enqueuing to immediately precede the
call to switch_to() from the scheduler.

Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Linus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: Richard Weinberger <richard@nod.at>
Reported-by: Toralf Förster <toralf.foerster@gmx.de>
CC: dhowells@redhat.com

... rather than open-coding the 64bit versions.  endian.h has those guys.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>

... 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>

looks like a half-arsed duplicate of line->enabled

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>

put references to in and out chans associated with line into
explicit struct chan * fields in it.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>

now we can do that...

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>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>

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>

Set addr_assign_type correctly to NET_ADDR_RANDOM in case
a random MAC address was generated and assigned to the netdevice.

Return state from setup_etheraddr() about returning a random
MAC address or not and check this state in eth_configure().

Signed-off-by: Danny Kukawka <danny.kukawka@bisect.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

ubd_file_size() cannot use ubd_dev->cow.file because at this time
ubd_dev->cow.file is not initialized.
Therefore, ubd_file_size() will always report a wrong disk size when
COW files are used.
Reading from /dev/ubd* would crash the kernel.

We have to read the correct disk size from the COW file's backing
file.

Signed-off-by: Richard Weinberger <richard@nod.at>
CC: stable@kernel.org

delay_free_irq is always 0 for those...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>

... nothing declared there exists

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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>

I could use out_close1, but that seems to be the code path to close the fd
returned by os_create_unix_socket, and using it to close the fd returned
by mkstemp might lead to some confusion, so I don't do it.

Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
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>

replace it by ndo_set_rx_mode

Signed-off-by: Jiri Pirko <jpirko@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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>

Linux can have pids up to 4*1024*1024.  To handle such huge numbers
pid_buf needs to be larger.

Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
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>