When unbinding a serial driver that's being used as a serial console,
the kernel may crash with a NULL pointer dereference in a uart_*() function
called from uart_close () (e.g. uart_flush_buffer() or
uart_chars_in_buffer()).
To fix this, let uart_close() check for port->count == 0. If this is the
case, bail out early. Else tty_port_close_start() will make the port
counts inconsistent, printing out warnings like
tty_port_close_start: tty->count = 1 port count = 0.
and
tty_port_close_start: count = -1
and once uport == NULL, it will also crash.
Also fix the related crash in pr_debug() by checking for a non-NULL uport
first.
Detailed description:
On driver unbind, uart_remove_one_port() is called. Basically it;
- marks the port dead,
- calls tty_vhangup(),
- sets state->uart_port = NULL.
What will happen depends on whether the port is just in use by e.g. getty,
or was also opened as a console.
A. If the tty was not opened as a console:
- tty_vhangup() will (in __tty_hangup()):
- mark all file descriptors for this tty hung up by pointing them to
hung_up_tty_fops,
- call uart_hangup(), which sets port->count to 0.
- A subsequent uart_open() (this may be through /dev/ttyS*, or through
/dev/console if this is a serial console) will fail with -ENXIO as the
port was marked dead,
- uart_close() after the failed uart_open() will return early, as
tty_hung_up_p() (called from tty_port_close_start()) will notice it was
hung up.
B. If the tty was also opened as a console:
- tty_vhangup() will (in __tty_hangup()):
- mark non-console file descriptors for this tty hung up by pointing
them to hung_up_tty_fops,
- NOT call uart_hangup(), but instead call uart_close() for every
non-console file descriptor, so port->count will still have a
non-zero value afterwards.
- A subsequent uart_open() will fail with -ENXIO as the port was
marked dead,
- uart_close() after the failed uart_open() starts to misbehave:
- tty_hung_up_p() will not notice it was hung up,
- As port->count is non-zero, tty_port_close_start() will decrease
port->count, making the tty and port counts inconsistent. Later,
warnings like these will be printed:
tty_port_close_start: tty->count = 1 port count = 0.
and
tty_port_close_start: count = -1
- If all of this happens after state->uart_port was set to zero, a
NULL pointer dereference will happen.
Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch adds cond_sched() calls during wait loop to perform
other tasks.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
While reviewing an i2c driver for efm32 that needs a similar property
Wolfram Sang pointed out that "location" is a too generic name for something
that is efm32 specific. So add an appropriate namespace and fall back to the
generic name in case of failure.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cris allmodconfig:
drivers/tty/serial/max310x.c: In function 'max310x_ioctl':
drivers/tty/serial/max310x.c:885:3: error: implicit declaration of function 'copy_from_user' [-Werror=implicit-function-declaration]
drivers/tty/serial/max310x.c:916:3: error: implicit declaration of function 'copy_to_user' [-Werror=implicit-function-declaration]
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The hdlcdev_ioctl() code fails to initialize the two padding bytes of
struct sync_serial_settings after the ->loopback member. Add an explicit
memset(0) before filling the structure to avoid the info leak.
Signed-off-by: Salva Peiró <speiro@ai2.upv.es>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In -RT the spin_lock_irqsave() does not spin but sleep if the lock is
taken. Before that, local_irq_save() is invoked which disables
interrupts even on -RT. Therefore local_irq_save() + spin_lock() does not
work.
In the ->sysrq and oops_in_progress case it is save to trylock the lock
i.e. this is what we do now anyway except for ->sysrq where we assume
that the lock is already taken.
The spin_lock_irqsave() grabs the lock and disables the interrupts on
vanilla (the same behavior) and on -RT it won't disable interrupts.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[bigeasy: add a patch description]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull drm fixes from Dave Airlie:
"Not a huge amount happening, some MAINTAINERS updates, radeon, vmwgfx
and tegra fixes"
* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
drm/vmwgfx: avoid null pointer dereference at failure paths
drm/vmwgfx: Make sure backing mobs are cleared when allocated. Update driver date.
drm/vmwgfx: Remove some unused surface formats
drm/radeon: enable speaker allocation setup on dce3.2
drm/radeon: change audio enable logic
drm/radeon: fix audio disable on dce6+
drm/radeon: free uvd ring on unload
drm/radeon: disable pll sharing for DP on DCE4.1
drm/radeon: fix missing bo reservation
drm/radeon: print the supported atpx function mask
MAINTAINERS: update drm git tree entry
MAINTAINERS: add entry for drm radeon driver
drm/tegra: Add guard to avoid double disable/enable of RGB outputs
gpu: host1x: do not check previously handled gathers
drm/tegra: fix typo 'CONFIG_TEGRA_DRM_FBDEV'
Pull USB fixes from Greg KH:
"Here are 2 USB patches for 3.14-rc5, one a new device id, and the
other fixes a reported problem with threaded irqs and the USB EHCI
driver"
* tag 'usb-3.14-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
usb: ehci: fix deadlock when threadirqs option is used
USB: ftdi_sio: add Cressi Leonardo PID
Pull sysfs fix from Greg KH:
"Here is a single sysfs fix for 3.14-rc5. It fixes a reported problem
with the namespace code in sysfs"
* tag 'driver-core-3.14-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
sysfs: fix namespace refcnt leak
Pull staging tree fixes from Greg KH:
"Here are a few IIO fixes, and a new device id for a staging driver for
3.14-rc5. All have been in linux-next for a while, I did a final
merge to get the IIO fixes into this tree, they were incorrectly in
the char-misc tree for a few weeks, and I forgot to tell you to pull
them from there. This makes it a single pull request for you"
* tag 'staging-3.14-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
staging: r8188eu: Add new device ID
staging:iio:adc:MXS:LRADC: fix touchscreen statemachine
iio:gyro: bug on L3GD20H gyroscope support
iio: cm32181: Change cm32181 ambient light sensor driver
iio: cm36651: Fix read/write integration time function.
more radeon fixes
* 'drm-fixes-3.14' of git://people.freedesktop.org/~agd5f/linux:
drm/radeon: enable speaker allocation setup on dce3.2
drm/radeon: change audio enable logic
drm/radeon: fix audio disable on dce6+
drm/radeon: free uvd ring on unload
drm/radeon: disable pll sharing for DP on DCE4.1
drm/radeon: fix missing bo reservation
drm/radeon: print the supported atpx function mask
Pull perf fixes from Ingo Molnar:
"Misc fixes, most of them on the tooling side"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf tools: Fix strict alias issue for find_first_bit
perf tools: fix BFD detection on opensuse
perf: Fix hotplug splat
perf/x86: Fix event scheduling
perf symbols: Destroy unused symsrcs
perf annotate: Check availability of annotate when processing samples
A couple of minor fixes.
Pull request of 2014-03-02
* tag 'vmwgfx-fixes-3.14-2014-03-02' of git://people.freedesktop.org/~thomash/linux:
drm/vmwgfx: avoid null pointer dereference at failure paths
drm/vmwgfx: Make sure backing mobs are cleared when allocated. Update driver date.
drm/vmwgfx: Remove some unused surface formats
vmw_takedown_otable_base() and vmw_mob_unbind() check for
potential vmw_fifo_reserve() failure and print error message,
but then immediately dereference NULL pointer.
Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Reviewed-by: Thomas Hellstrom <thellstrom@vmware.com>
Backing mob contents is propagated to user-space, so make sure backing
mobs are cleared when allocated. This also accidently fix rendering errors
with celestia when emulating legacy mode.
Also update driver date.
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Brian Paul <brianp@vmware.com>
Pull x86 fixes from Peter Anvin:
"The VMCOREINFO patch I'll pushing for this release to avoid having a
release with kASLR and but without that information.
I was hoping to include the FPU patches from Suresh, but ran into a
problem (see other thread); will try to make them happen next week"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, kaslr: add missed "static" declarations
x86, kaslr: export offset in VMCOREINFO ELF notes
Pull SCSI target fixes from Nicholas Bellinger:
"The bulk of the series are bugfixes for qla2xxx target NPIV support
that went in for v3.14-rc1. Also included are a few DIF related
fixes, a qla2xxx fix (Cc'ed to stable) from Greg W., and vhost/scsi
protocol version related fix from Venkatesh.
Also just a heads up that a series to address a number of issues with
iser-target active I/O reset/shutdown is still being tested, and will
be included in a separate -rc6 PULL request"
* git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending:
vhost/scsi: Check LUN structure byte 0 is set to 1, per spec
qla2xxx: Fix kernel panic on selective retransmission request
Target/sbc: Don't use sg as iterator in sbc_verify_read
target: Add DIF sense codes in transport_generic_request_failure
target/sbc: Fix sbc_dif_copy_prot addr offset bug
tcm_qla2xxx: Fix NAA formatted name for NPIV WWPNs
tcm_qla2xxx: Perform configfs depend/undepend for base_tpg
tcm_qla2xxx: Add NPIV specific enable/disable attribute logic
qla2xxx: Check + fail when npiv_vports_inuse exists in shutdown
qla2xxx: Fix qlt_lport_register base_vha callback race
Pull slave-dma fixes from Vinod Koul:
"This request brings you two small fixes. First one for fixing
dereference of freed descriptor and second for fixing sdma bindings
for it to work for imx25.
I was planning to send this about 10days ago but then I had to proceed
on my paternity leave and didnt get chance to send this. Now got a
bit of time from dady duties :)"
* 'fixes' of git://git.infradead.org/users/vkoul/slave-dma:
dma: sdma: Add imx25 compatible
dma: ste_dma40: don't dereference free:d descriptor
Pull ACPI and power management fixes from Rafael Wysocki:
"These three commits fix a recent intel_pstate regression and two old
bugs that should be fixed in -stable too, one in the ACPI processor
driver and one in the firmare loader.
Specifics:
- One of the recent intel_pstate driver fixes introduced a rounding
error that on some systems causes the frequency to be stuck at the
lowest level forever. Fix from Dirk Brandewie.
- The firmware_class driver's PM notifier doesn't handle the
PM_RESTORE_PREPARE event during hibernation image restore and that
leads to a deadlock on umhelper_sem in __usermodehelper_disable().
Fix from Sebastian Capella.
- acpi_processor_set_throttling() abuses set_cpus_allowed_ptr() in a
nasty way which triggers the WARN_ON_ONCE() in wq_worker_waking_up()
among other things. Fix from Lan Tianyu"
* tag 'pm+acpi-3.14-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
ACPI / processor: Rework processor throttling with work_on_cpu()
PM / hibernate: Fix restore hang in freeze_processes()
intel_pstate: Change busy calculation to use fixed point math.
Pull perf/urgent build fixes for certain distro environments, from Arnaldo Carvalho de Melo:
* Problem on recent gcc on x86-32 related to strict alias issue for
find_first_bit (Jiri Olsa).
* OpenSuSE: BFD detection problems related to not explicitely listing all
required libraries (Andi Kleen)
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Jonathan writes:
Fourth set of IIO fixes for the 3.14 kernel.
A single line patch fixing a regression that was introduced in 3.13 in the
reworking of the mxs touch screen and ADC drivers to be interrupt rather
than polling driven. It resulted in a stray double reporting of the release
coordinate in the touch screen driver. The bug lay in the adc side
of the driver which left the statemachine in the wrong state.
If cpufreq_register_notifier() fails, we have to remove the port added by
sci_probe_single(), which is not done by sci_cleanup_single().
Else the serial port stays active from the point of view of the serial
subsystem, and it may crash when userspace getty is started, or when the
loadable driver module is unloaded.
This was introduced by commit 6dae14216c
("serial: sh-sci: Fix probe error paths").
Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If the serial port being removed is used as a console, it must also be
unregistered from the console subsystem using unregister_console().
uart_ops.release_port() will release resources (e.g. iounmap() the serial
port registers), causing a crash on subsequent kernel output if the console
is still registered.
Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 95e629b761 removed the use of board
specific hooks in serial_at91.h, so now, the open/close hook are just
dead code.
Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The 'active' sysfs attribute should refer to the currently active tty
devices the console is running on, not the currently active console. The
console structure doesn't refer to any device in sysfs, only the tty the
console is running on has. So we need to print out the tty names in
'active', not the console names.
There is one special-case, which is tty0. If the console is directed to
it, we want 'tty0' to show up in the file, so user-space knows that the
messages get forwarded to the active VT. The ->device() callback would
resolve tty0, though. Hence, treat it special and don't call into the VT
layer to resolve it (plymouth is known to depend on it).
Cc: Lennart Poettering <lennart@poettering.net>
Cc: Kay Sievers <kay@vrfy.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Werner Fink <werner@suse.de>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use devm_ioremap_resource() in order to make the code simpler and
it gives proper codes on errors.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The user-settable knob, low_latency, has been the source of
several BUG reports which stem from flush_to_ldisc() running
in interrupt context. Since 3.12, which added several sleeping
locks (termios_rwsem and buf->lock) to the input processing path,
the frequency of these BUG reports has increased.
Note that changes in 3.12 did not introduce this regression;
sleeping locks were first added to the input processing path
with the removal of the BKL from N_TTY in commit
a88a69c912,
'n_tty: Fix loss of echoed characters and remove bkl from n_tty'
and later in commit 38db89799b,
'tty: throttling race fix'. Since those changes, executing
flush_to_ldisc() in interrupt_context (ie, low_latency set), is unsafe.
However, since most devices do not validate if the low_latency
setting is appropriate for the context (process or interrupt) in
which they receive data, some reports are due to misconfiguration.
Further, serial dma devices for which dma fails, resort to
interrupt receiving as a backup without resetting low_latency.
Historically, low_latency was used to force wake-up the reading
process rather than wait for the next scheduler tick. The
effect was to trim multiple milliseconds of latency from
when the process would receive new data.
Recent tests [1] have shown that the reading process now receives
data with only 10's of microseconds latency without low_latency set.
Remove the low_latency rx steering from tty_flip_buffer_push();
however, leave the knob as an optional hint to drivers that can
tune their rx fifos and such like. Cleanup stale code comments
regarding low_latency.
[1] https://lkml.org/lkml/2014/2/20/434
"Yay.. thats an annoying historical pain in the butt gone."
-- Alan Cox
Reported-by: Beat Bolli <bbolli@ewanet.ch>
Reported-by: Pavel Roskin <proski@gnu.org>
Acked-by: David Sterba <dsterba@suse.cz>
Cc: Grant Edwards <grant.b.edwards@gmail.com>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Hal Murray <murray+fedora@ip-64-139-1-69.sjc.megapath.net>
Cc: <stable@vger.kernel.org> # 3.12.x+
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add a matching table for the the bcm63xx_uart driver on the compatible
string "brcm,bcm6345-uart" which covers all BCM63xx implementations and
reflects the fact that this block was first introduced with the BCM6345
SoC. Also make sure that we convert the id based on the uart aliases
provided by the relevant Device Tree.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The bcm63xx_uart driver uses RSET_UART_SIZE which is a constant defined
for MIPS-based BCM63xx platforms, pull this constant value from the
MIPS-specific header and put it in include/linux/serial_bcm63xx.h to
make the driver platform agnostic.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Include linux/io.h which provides the definition for
__raw_{readl,writel}, this is not necessary on MIPS since there is an
implicit inclusion, but it is on ARM for instance.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
These can be used to send commands consisting of an arbitrary string to the
terminal, most often used to set a terminal's window title or to redefine
the colour palette. Our console doesn't use OSC, unlike everything else,
which can lead to junk being displayed if a process sends such a code
unconditionally.
The rules for termination follow established practice rather than Ecma-48.
Ecma-48 requires the string to use only byte values 0x08..0x0D and
0x20..0x7E, terminated with either ESC \ or 0x9C. This would disallow using
8-bit characters, which are reasonable for example in window titles.
A widespread idiom is to terminate with 0x07. The behaviour for other
control characters differs between terminal emulators, I followed libvte and
xterm:
* 0x07 and ESC anything terminate
* nothing else terminates, all 8-bit values including 0x9C are considered a
part of the string
Signed-off-by: Adam Borowski <kilobyte@angband.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Every couple of months, someone sends a patch to fix:
drivers/tty/serial/8250/8250_core.c: In function 'serial_unlink_irq_chain':
drivers/tty/serial/8250/8250_core.c:1712:2: warning: 'i' may be used uninitialized in this function [-Wuninitialized]
and they in turn get a NACK for their efforts, and are told that
their compiler is broken. This has been going on since at least
the year 2008: https://lkml.org/lkml/2008/11/24/433
Lets add a comment, so that subsequent patches don't get as far as
the maintainers or the mailing lists.
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
