This patch continues 10dce8af3422 (fs: stream_open - opener for
stream-like files so that read and write can run simultaneously without
deadlock) and c5bf68fe0c86 (*: convert stream-like files from
nonseekable_open -> stream_open) and teaches steam_open.cocci to
consider files as being stream-like not only if they have
.llseek=no_llseek, but also if they have .llseek=noop_llseek.

This is safe to do: the comment about noop_llseek says

	This is an implementation of ->llseek useable for the rare special case when
	userspace expects the seek to succeed but the (device) file is actually not
	able to perform the seek. In this case you use noop_llseek() instead of
	falling back to the default implementation of ->llseek.

and in general noop_llseek was massively added to drivers in 6038f373a3dc
(llseek: automatically add .llseek fop) when changing default for NULL .llseek
from NOP to no_llseek with the idea to avoid breaking compatibility, if
maybe some user-space program was using lseek on a device without caring
about the result, but caring if it was an error or not.

Amended semantic patch produces two changes when applied tree-wide:

        drivers/hid/hid-sensor-custom.c:690:8-24: WARNING: hid_sensor_custom_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.
        drivers/input/mousedev.c:564:1-17: ERROR: mousedev_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix.

Cc: Julia Lawall <Julia.Lawall@lip6.fr>
Cc: Jan Blunck <jblunck@suse.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Kirill Smelkov <kirr@nexedi.com>

Based on 2 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

syzbot was able to trigger rcu stalls by calling write()
with large number of bytes.

Add a cond_resched() in the loop to avoid this.

Link: https://lkml.org/lkml/2018/8/23/1106
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot+9436b02171ac0894d33e@syzkaller.appspotmail.com
Reviewed-by: Paul E. McKenney <paulmck@linux.ibm.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

This is the mindless scripted replacement of kernel use of POLL*
variables as described by Al, done by this script:

    for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do
        L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'`
        for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done
    done

with de-mangling cleanups yet to come.

NOTE! On almost all architectures, the EPOLL* constants have the same
values as the POLL* constants do.  But they keyword here is "almost".
For various bad reasons they aren't the same, and epoll() doesn't
actually work quite correctly in some cases due to this on Sparc et al.

The next patch from Al will sort out the final differences, and we
should be all done.

Scripted-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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

Clang warns:

drivers/input/mousedev.c:653:63: error: implicit conversion from 'int'
to 'signed char' changes value from 200 to -56
[-Wconstant-conversion]
  client->ps2[1] = 0x60; client->ps2[2] = 3; client->ps2[3] = 200;
                                                            ~ ^~~
As the PS2 data is really a stream of bytes, let's switch to using u8 type
for it, which silences this warning.

Signed-off-by: Nick Desaulniers <nick.desaulniers@gmail.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Replace the open coded registration of the cdev and dev with the
new device_add_cdev() helper in evdev, joydev and mousedev. The helper
replaces a common pattern by taking the proper reference against the
parent device and adding both the cdev and the device.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

We should not be using static variable mousedev_mix in methods that can be
called before that singleton gets assigned. While at it let's add open and
close methods to mousedev structure so that we do not need to test if we
are dealing with multiplexor or normal device and simply call appropriate
method directly.

This fixes: https://bugzilla.kernel.org/show_bug.cgi?id=71551

Reported-by: GiulioDP <depasquale.giulio@gmail.com>
Tested-by: GiulioDP <depasquale.giulio@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

When doing conversion to dynamic input numbers I inadvertently moved
/dev/input/mice from c,13,63 to c,13,31. We need to fix this so that
setups with statically populated /dev continue working.

Tested-by: Krzysztof Mazur <krzysiek@podlesie.net>
Tested-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Commit 7f8d4cad1e4e ("Input: extend the number of event (and other)
devices") made evdev, joydev and mousedev to embed struct cdev into
their respective structures representing input devices.

Unfortunately character device structure may outlive the parent
structure unless we do not set it up as parent of character device so
that it will stay pinned until character device is freed.

Also, now that parent structure is pinned while character device exists
we do not need to pin and unpin it every time user opens or closes it.

Reported-by: Dave Jones <davej@redhat.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>