The functions tty_audit_add_data() and tty_audit_tiocsti() are local to
the tty core code, and do not need to be in a "kernel-wide" header file
so move them to drivers/tty/tty.h

Cc: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20210408125134.3016837-9-gregkh@linuxfoundation.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

No one is calling this macro, and no one should, so remove it from the
.h file.

Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20210408125134.3016837-3-gregkh@linuxfoundation.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

There are a number of functions and #defines in include/linux/tty.h that
do not belong there as they are private to the tty core code.

Create an initial drivers/tty/tty.h file and copy the odd "tty logging"
macros into it to seed the file with some initial things that we know
nothing outside of the tty core should be calling.

Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20210408125134.3016837-2-gregkh@linuxfoundation.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add the error path for registering tty devices and roll back in case of error
in bid to avoid the UAF like the below one reported.

Plus syzbot reported general protection fault in cdev_del() on Sep 24, 2020
and both cases are down to the kobject_put() in tty_cdev_add().

 ------------[ cut here ]------------
 refcount_t: underflow; use-after-free.
 WARNING: CPU: 1 PID: 8923 at lib/refcount.c:28
 refcount_warn_saturate+0x1cf/0x210 -origin/lib/refcount.c:28
 Modules linked in:
 CPU: 1 PID: 8923 Comm: executor Not tainted 5.12.0-rc5+ #8
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
 1.13.0-1ubuntu1.1 04/01/2014
 RIP: 0010:refcount_warn_saturate+0x1cf/0x210 -origin/lib/refcount.c:28
 Code: 4f ff ff ff e8 32 fa b5 fe 48 c7 c7 3d f8 f6 86 e8 d6 ab c6 fe
 c6 05 7c 34 67 04 01 48 c7 c7 68 f8 6d 86 31 c0 e8 81 2e 9d fe <0f> 0b
 e9 22 ff ff ff e8 05 fa b5 fe 48 c7 c7 3e f8 f6 86 e8 a9 ab
 RSP: 0018:ffffc90001633c60 EFLAGS: 00010246
 RAX: 15d08b2e34b77800 RBX: 0000000000000003 RCX: ffff88804c056c80
 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
 RBP: 0000000000000003 R08: ffffffff813767aa R09: 0001ffffffffffff
 R10: 0001ffffffffffff R11: ffff88804c056c80 R12: ffff888040b7d000
 R13: ffff88804c206938 R14: ffff88804c206900 R15: ffff888041b18488
 FS:  00000000022c9940(0000) GS:ffff88807ec00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 00007f9f9b122008 CR3: 0000000044b4b000 CR4: 0000000000750ee0
 PKRU: 55555554
 Call Trace:
  __refcount_sub_and_test -origin/./include/linux/refcount.h:283 [inline]
  __refcount_dec_and_test -origin/./include/linux/refcount.h:315 [inline]
  refcount_dec_and_test -origin/./include/linux/refcount.h:333 [inline]
  kref_put -origin/./include/linux/kref.h:64 [inline]
  kobject_put+0x17b/0x180 -origin/lib/kobject.c:753
  cdev_del+0x4b/0x50 -origin/fs/char_dev.c:597
  tty_unregister_device+0x99/0xd0 -origin/drivers/tty/tty_io.c:3343
  gsmld_detach_gsm -origin/drivers/tty/n_gsm.c:2409 [inline]
  gsmld_close+0x6c/0x140 -origin/drivers/tty/n_gsm.c:2478
  tty_ldisc_close -origin/drivers/tty/tty_ldisc.c:488 [inline]
  tty_ldisc_kill -origin/drivers/tty/tty_ldisc.c:636 [inline]
  tty_ldisc_release+0x1b6/0x400 -origin/drivers/tty/tty_ldisc.c:809
  tty_release_struct+0x19/0xb0 -origin/drivers/tty/tty_io.c:1714
  tty_release+0x9ad/0xa00 -origin/drivers/tty/tty_io.c:1885
  __fput+0x260/0x4e0 -origin/fs/file_table.c:280
  ____fput+0x11/0x20 -origin/fs/file_table.c:313
  task_work_run+0x8e/0x110 -origin/kernel/task_work.c:140
  tracehook_notify_resume -origin/./include/linux/tracehook.h:189 [inline]
  exit_to_user_mode_loop -origin/kernel/entry/common.c:174 [inline]
  exit_to_user_mode_prepare+0x16b/0x1a0 -origin/kernel/entry/common.c:208
  __syscall_exit_to_user_mode_work -origin/kernel/entry/common.c:290 [inline]
  syscall_exit_to_user_mode+0x20/0x40 -origin/kernel/entry/common.c:301
  do_syscall_64+0x45/0x80 -origin/arch/x86/entry/common.c:56
  entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported-by: syzbot+c49fe6089f295a05e6f8@syzkaller.appspotmail.com
Reported-and-tested-by: NHao Sun <sunhao.th@gmail.com>
Signed-off-by: NHillf Danton <hdanton@sina.com>
Link: https://lore.kernel.org/r/20210412035758.1974-1-hdanton@sina.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

These correspond to the existing lpc_address, sirq, and sirq_polarity
sysfs attributes; the second element of aspeed,lpc-interrupts provides
a replacement for the deprecated aspeed,sirq-polarity-sense property.
Reviewed-by: NRob Herring <robh@kernel.org>
Signed-off-by: NZev Weiss <zev@bewilderbeest.net>
Link: https://lore.kernel.org/r/20210412034712.16778-5-zev@bewilderbeest.netSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

These allow describing all the Aspeed VUART attributes currently
available via sysfs.  aspeed,lpc-interrupts provides a replacement for
the deprecated aspeed,sirq-polarity-sense property.
Reviewed-by: NAndrew Jeffery <andrew@aj.id.au>
Signed-off-by: NZev Weiss <zev@bewilderbeest.net>
Link: https://lore.kernel.org/r/20210412034712.16778-4-zev@bewilderbeest.netSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This splits dedicated aspeed_vuart_set_{sirq,lpc_address}() functions
out of the sysfs store functions in preparation for adding DT
properties that will be poking the same registers.  While we're at it,
these functions now provide some basic bounds-checking on their
arguments.
Reviewed-by: NAndrew Jeffery <andrew@aj.id.au>
Signed-off-by: NZev Weiss <zev@bewilderbeest.net>
Link: https://lore.kernel.org/r/20210412034712.16778-3-zev@bewilderbeest.netSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This property ties SIRQ polarity to SCU register bits that don't
necessarily have any direct relationship to it; the only use of it was
removed in commit c82bf6e1 ("ARM: aspeed: g5: Do not set sirq
polarity").
Reviewed-by: NJoel Stanley <joel@jms.id.au>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NZev Weiss <zev@bewilderbeest.net>
Link: https://lore.kernel.org/r/20210412034712.16778-2-zev@bewilderbeest.netSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The sparse tool complains as follows:

drivers/tty/hvc/hvc_udbg.c:20:19: warning:
 symbol 'hvc_udbg_dev' was not declared. Should it be static?

This symbol is not used outside of hvc_udbg.c, so this
commit marks it static.
Reported-by: NHulk Robot <hulkci@huawei.com>
Signed-off-by: NYu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20210407125826.4139130-1-yukuai3@huawei.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit 30004ac9 ("tty: add tty_struct->dev pointer to corresponding
device instance") added a struct device pointer field to struct
tty_struct which was populated with the corresponding tty class device
during initialisation.

Unfortunately, not all ttys have a class device (e.g. pseudoterminals
and serdev) in which case the device pointer will be set to NULL,
something which have bit driver authors over the years.

In retrospect perhaps this field should never have been added, but let's
at least document the current behaviour.
Signed-off-by: NJohan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210409073512.6876-1-johan@kernel.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch adds missing MODULE_DEVICE_TABLE definition which generates
correct modalias for automatic loading of this driver when it is built
as an external module.
Reported-by: NHulk Robot <hulkci@huawei.com>
Signed-off-by: NBixuan Cui <cuibixuan@huawei.com>
Link: https://lore.kernel.org/r/20210410035048.11466-1-cuibixuan@huawei.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Include the generic serial.yaml dtschema so the child node like
"bluetooth" will be properly matched:

  arch/arm/boot/dts/exynos4210-universal_c210.dt.yaml:
    serial@13800000: 'bluetooth' does not match any of the regexes: 'pinctrl-[0-9]+'
Reviewed-by: NRob Herring <robh@kernel.org>
Signed-off-by: NKrzysztof Kozlowski <krzk@kernel.org>
Link: https://lore.kernel.org/r/20210409172027.11296-1-krzysztof.kozlowski@canonical.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Drivers can return -ENOIOCTLCMD when an ioctl is not recognised to tell
the upper layers to continue looking for a handler.

This is not the case for the RS485 and ISO7816 ioctls whose handlers
should return -ENOTTY directly in case a serial driver does not
implement the corresponding methods.

Fixes: a5f276f1 ("serial_core: Handle TIOC[GS]RS485 ioctls.")
Fixes: ad8c0eaa ("tty/serial_core: add ISO7816 infrastructure")
Signed-off-by: NJohan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210407095208.31838-9-johan@kernel.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Since commit 5099d234 ("serial_core: switch to ->[sg]et_serial()")
the serial structure passed to uart_get_info() has already have been
cleared by the tty layer so drop the redundant memset.
Signed-off-by: NJohan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210407095208.31838-8-johan@kernel.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Callout devices are long-gone, but the ASYNC_SPLIT_TERMIOS flag was
never added to the deprecation mask.

Add it so that a warning is printed if it is ever used.

Fixes: 8a8ae62f ("tty: warn on deprecated serial flags")
Signed-off-by: NJohan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210407095208.31838-7-johan@kernel.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Factor out the deprecated serial flags handling and tty-operation check
shared with the compat TIOCSSERIAL handler.
Signed-off-by: NJohan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210407095208.31838-6-johan@kernel.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Use pr_warn_ratelimited() when warning about deprecated serial flags
instead of open coding.
Signed-off-by: NJohan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210407095208.31838-5-johan@kernel.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Drivers should return -ENOTTY ("Inappropriate I/O control operation")
when an ioctl isn't supported, while -EINVAL is used for invalid
arguments.

Support for termiox was added by commit 1d65b4a0 ("tty: Add
termiox") in 2008 but no driver support ever followed and it was
recently ripped out by commit e0efb316 ("tty: Remove dead termiox
code").

Fix the return value for the unsupported termiox ioctls, which have
always returned -EINVAL, by explicitly returning -ENOTTY rather than
removing them completely and falling back to the default unrecognised-
ioctl handling.

Fixes: 1d65b4a0 ("tty: Add termiox")
Signed-off-by: NJohan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210407095208.31838-4-johan@kernel.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Drivers should return -ENOTTY ("Inappropriate I/O control operation")
when an ioctl isn't supported, while -EINVAL is used for invalid
arguments.

Fix up the TIOCMGET, TIOCMSET and TIOCGICOUNT helpers which returned
-EINVAL when a tty driver did not implement the corresponding
operations.

Note that the TIOCMGET and TIOCMSET helpers predate git and do not get a
corresponding Fixes tag below.

Fixes: d281da7f ("tty: Make tiocgicount a handler")
Signed-off-by: NJohan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210407095208.31838-3-johan@kernel.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Some kernel-internal ASYNC flags have been superseded by tty-port flags
and should no longer be used by kernel drivers.

Fix the misspelled "__KERNEL__" compile guards which failed their sole
purpose to break out-of-tree drivers that have not yet been updated.

Fixes: 5c0517fe ("tty: core: Undefine ASYNC_* flags superceded by TTY_PORT* flags")
Signed-off-by: NJohan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210407095208.31838-2-johan@kernel.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Remove the repeated word 'the' following advice of checkpatch.pl
Signed-off-by: NXiaofei Tan <tanxiaofei@huawei.com>
Link: https://lore.kernel.org/r/1617779210-51576-11-git-send-email-tanxiaofei@huawei.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Do not use assignment in if condition following the advice of
checkpatch.pl.
Signed-off-by: NXiaofei Tan <tanxiaofei@huawei.com>
Link: https://lore.kernel.org/r/1617779210-51576-10-git-send-email-tanxiaofei@huawei.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Fix coding style issues of block comments, reported by checkpatch.pl.
Signed-off-by: NXiaofei Tan <tanxiaofei@huawei.com>
Link: https://lore.kernel.org/r/1617779210-51576-9-git-send-email-tanxiaofei@huawei.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add a blank line after declarations, reported by checkpatch.pl.
Signed-off-by: NXiaofei Tan <tanxiaofei@huawei.com>
Link: https://lore.kernel.org/r/1617779210-51576-8-git-send-email-tanxiaofei@huawei.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Fix an issue of code indent should use tabs, reported by checkpatch.pl.
Signed-off-by: NXiaofei Tan <tanxiaofei@huawei.com>
Link: https://lore.kernel.org/r/1617779210-51576-7-git-send-email-tanxiaofei@huawei.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Remove spaces before tabs following the advice of checkpatch.pl.
Signed-off-by: NXiaofei Tan <tanxiaofei@huawei.com>
Link: https://lore.kernel.org/r/1617779210-51576-6-git-send-email-tanxiaofei@huawei.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Fix coding style issues of block comments, reported by checkpatch.pl.
Besides, do some expression optimization for the sentenses.
Signed-off-by: NXiaofei Tan <tanxiaofei@huawei.com>
Link: https://lore.kernel.org/r/1617779210-51576-5-git-send-email-tanxiaofei@huawei.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add a blank line after declarations, reported by checkpatch.pl.
Signed-off-by: NXiaofei Tan <tanxiaofei@huawei.com>
Link: https://lore.kernel.org/r/1617779210-51576-4-git-send-email-tanxiaofei@huawei.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Fix issues of code indent should use tabs, reported by checkpatch.pl.
Signed-off-by: NXiaofei Tan <tanxiaofei@huawei.com>
Link: https://lore.kernel.org/r/1617779210-51576-3-git-send-email-tanxiaofei@huawei.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add a blank line after declarations, reported by checkpatch.pl.
Signed-off-by: NXiaofei Tan <tanxiaofei@huawei.com>
Link: https://lore.kernel.org/r/1617779210-51576-2-git-send-email-tanxiaofei@huawei.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The commit 8ba59e9d ("misc: pti: Remove driver for deprecated platform")
got rid of deprecated drivers under TTY subsystem, but cleaned only one Kconfig
entry. Remove Kconfig leftovers.

Fixes: 8ba59e9d ("misc: pti: Remove driver for deprecated platform")
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210406131615.85432-1-andriy.shevchenko@linux.intel.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The port close_delay and closing_wait parameters have already been by
tty_port_init() so drop the redundant driver initialisation to the
default values.
Signed-off-by: NJohan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210407102334.32361-17-johan@kernel.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The port close_delay and closing_wait parameters have already been by
tty_port_init() so drop the redundant driver initialisation to the
default values.
Signed-off-by: NJohan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210407102334.32361-16-johan@kernel.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Changing the port type and closing_wait parameter are privileged
operations so make sure to return -EPERM if a regular user tries to
change them.

Note that the closing_wait parameter would not actually have been
changed but the return value did not indicate that.

Cc: stable@vger.kernel.org
Signed-off-by: NJohan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210407102334.32361-15-johan@kernel.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The port close_delay and closing wait parameters set by TIOCSSERIAL are
specified in jiffies, while the values returned by TIOCGSERIAL are
specified in centiseconds.

Add the missing conversions so that TIOCSSERIAL works as expected also
when HZ is not 100.

Cc: stable@vger.kernel.org
Signed-off-by: NJohan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210407102334.32361-14-johan@kernel.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

TIOCSSERIAL is a horrid, underspecified, legacy interface which for most
serial devices is only useful for setting the close_delay and
closing_wait parameters.

A non-privileged user has only ever been able to set the since long
deprecated ASYNC_SPD flags and trying to change any other *supported*
feature should result in -EPERM being returned. Setting the current
values for any supported features should return success.

Fix the moxa implementation which was returning -EPERM also for a
privileged user when trying to change certain unsupported parameters and
instead return success consistently.
Signed-off-by: NJohan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210407102334.32361-13-johan@kernel.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Changing the port close delay or type are privileged operations so make
sure to return -EPERM if a regular user tries to change them.

Cc: stable@vger.kernel.org
Signed-off-by: NJohan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210407102334.32361-12-johan@kernel.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The port close_delay parameter set by TIOCSSERIAL is specified in
jiffies, while the value returned by TIOCGSERIAL is specified in
centiseconds.

Add the missing conversions so that TIOCGSERIAL works as expected also
when HZ is not 100.

Cc: stable@vger.kernel.org
Signed-off-by: NJohan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210407102334.32361-11-johan@kernel.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The tty-port close_delay and closing_wait parameters set by TIOCSSERIAL
are specified in jiffies, while the values returned by TIOCGSERIAL are
specified in centiseconds.

Add the missing conversions so that TIOCSSERIAL works as expected also
if this code is ever reused on a system where HZ is not 100.
Signed-off-by: NJohan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210407102334.32361-10-johan@kernel.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Changing the port closing_wait parameter is a privileged operation.

Add the missing check to TIOCSSERIAL so that -EPERM is returned in case
an unprivileged user tries to change the closing-wait setting.

Cc: stable@vger.kernel.org
Signed-off-by: NJohan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210407102334.32361-9-johan@kernel.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>