If a ftrace ops is registered with the SAVE_REGS flag set, and there's
already a ops registered to one of its functions but without the
SAVE_REGS flag, there's a small race window where the SAVE_REGS ops gets
added to the list of callbacks to call for that function before the
callback trampoline gets set to save the regs.
The problem is, the function is not currently saving regs, which opens
a small race window where the ops that is expecting regs to be passed
to it, wont. This can cause a crash if the callback were to reference
the regs, as the SAVE_REGS guarantees that regs will be set.
To fix this, we add a check in the loop case where it checks if the ops
has the SAVE_REGS flag set, and if so, it will ignore it if regs is
not set.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tracing_open() and tracing_snapshot_open() are racy, the memory
inode->i_private points to can be already freed.
Convert these last users of "inode->i_private == trace_cpu" to
use "i_private = trace_array" and rely on tracing_get_cpu().
v2: incorporate the fix from Steven, tracing_release() must not
blindly dereference file->private_data unless we know that
the file was opened for reading.
But tc (and tr) can be already freed before trace_array_get() is called.
And it doesn't matter whether this file is per-cpu or it was created by
init_tracer_debugfs(), free_percpu() or kfree() are equally bad.
Note that even 1. is not safe, the freed memory can be unmapped. But even
if it was safe trace_array_get() can wrongly succeed if we also race with
the next new_instance_create() which can re-allocate the same tr, or tc
was overwritten and ->tr points to the valid tr. In this case 3. uses the
freed/reused memory.
Add the new trivial helper, trace_create_cpu_file() which simply calls
trace_create_file() and encodes "cpu" in "struct inode". Another helper,
tracing_get_cpu() will be used to read cpu_nr-or-RING_BUFFER_ALL_CPUS.
The patch abuses ->i_cdev to encode the number, it is never used unless
the file is S_ISCHR(). But we could use something else, say, i_bytes or
even ->d_fsdata. In any case this hack is hidden inside these 2 helpers,
it would be trivial to change them if needed.
This patch only changes tracing_init_debugfs_percpu() to use the new
trace_create_cpu_file(), the next patches will change file_operations.
Note: tracing_get_cpu(inode) is always safe but you can't trust the
result unless trace_array_get() was called, without trace_types_lock
which acts as a barrier it can wrongly return RING_BUFFER_ALL_CPUS.
Link: http://lkml.kernel.org/r/20130723152554.GA23710@redhat.com Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Wait for disabling all running kprobe handlers when a kprobe
event is disabled, since the caller, trace_remove_event_call()
supposes that a removing event is disabled completely by
disabling the event.
With this change, ftrace can ensure that there is no running
event handlers after disabling it.
As the firmware API has changed significantly and we don't
have support code for the old APIs, bump the version to be
able to release the version 7 API firmware. Unfortunately
this means that the driver in 3.9 and 3.10 can't work, but
that's still better than crashing the device/driver there.
Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The MCAST queue should be enabled after DTIM only.
According to fw API, the MCAST must not be attached to any
station, but should appear in the mcast_qid of the AP's
mac context only.
In multicast, there is no retries nor RTS since there is no
specific recipient that can ACK or send CTS. This means
that we must not use the rate scale table for multicast
frames.
This true for any frame that doesn't have a valid
ieee80211_sta pointer.
The AP mode needs to use the MCAST fifo for the MCAST
frames sent after the DTIM. This fifo needs to be
configured with the same parameters as the VOICE FIFO.
A separate SCD queue is mapped to this fifo - the cab_queue
(cab stands for Content After Beacon). This queue isn't
connected to any station, but rather to the MAC context.
This queue should (and is already) be set as the MCAST
queue - this is part of the of MAC context command.
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com> Reviewed-by: Ilan Peer <ilan.peer@intel.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Without the new LLCP_CONNECTING state, non blocking sockets will be
woken up with a POLLHUP right after calling connect() because their
state is stuck at LLCP_CLOSED.
That prevents userspace from implementing any proper non blocking
socket based NFC p2p client.
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Due to a bug with RTC IMR, we cannot consider at91sam9x5 RTC compatible
with the previous one. Modify DT compatibility string, even if the driver
is not yet modified to take it into account.
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Vineet Gupta [Tue, 20 Aug 2013 08:08:10 +0000 (13:38 +0530)]
ARC: gdbserver breakage in Big-Endian configuration #1
[Based on mainline commit 502a0c775c7f0a: "ARC: pt_regs update #5"]
gdbserver needs @stop_pc, served by ptrace, but fetched from pt_regs
differently, based on in_brkpt_traps(), which in turn relies on
additional machine state in pt_regs->event bitfield.
unsigned long orig_r8:16, event:16;
For big endian config, this macro was returning false, despite being in
breakpoint Trap exception, causing wrong @stop_pc to be returned to gdb.
Issue #1: In BE, @event above is at offset 2 in word, while a STW insn
at offset 0 was used to update it. Resort to using ST insn
which updates the half-word at right location.
Issue #2: The union involving bitfields causes all the members to be
laid out at offset 0. So with fix #1 above, ASM was now
updating at offset 2, "C" code was still referencing at
offset 0. Fixed by wrapping bitfield in a struct.
In theory, under a given ACPI namespace node there should be only
one child device object with _ADR whose value matches a given bus
address exactly. In practice, however, there are systems in which
multiple child device objects under a given parent have _ADR matching
exactly the same address. In those cases we use _STA to determine
which of the multiple matching devices is enabled, since some systems
are known to indicate which ACPI device object to associate with the
given physical (usually PCI) device this way.
Unfortunately, as it turns out, there are systems in which many
device objects under the same parent have _ADR matching exactly the
same bus address and none of them has _STA, in which case they all
should be regarded as enabled according to the spec. Still, if
those device objects are supposed to represent bridges (e.g. this
is the case for device objects corresponding to PCIe ports), we can
try harder and skip the ones that have no child device objects in the
ACPI namespace. With luck, we can avoid using device objects that we
are not expected to use this way.
Although this only works for bridges whose children also have ACPI
namespace representation, it is sufficient to address graphics
adapter detection issues on some systems, so rework the code finding
a matching device ACPI handle for a given bus address to implement
this idea.
Introduce a new function, acpi_find_child(), taking three arguments:
the ACPI handle of the device's parent, a bus address suitable for
the device's bus type and a bool indicating if the device is a
bridge and make it work as outlined above. Reimplement the function
currently used for this purpose, acpi_get_child(), as a call to
acpi_find_child() with the last argument set to 'false' and make
the PCI subsystem use acpi_find_child() with the bridge information
passed as the last argument to it. [Lan Tianyu notices that it is
not sufficient to use pci_is_bridge() for that, because the device's
subordinate pointer hasn't been set yet at this point, so use
hdr_type instead.]
This change fixes a regression introduced inadvertently by commit 33f767d (ACPI: Rework acpi_get_child() to be more efficient) which
overlooked the fact that for acpi_walk_namespace() "post-order" means
"after all children have been visited" rather than "on the way back",
so for device objects without children and for namespace walks of
depth 1, as in the acpi_get_child() case, the "post-order" callbacks
ordering is actually the same as the ordering of "pre-order" ones.
Since that commit changed the namespace walk in acpi_get_child() to
terminate after finding the first matching object instead of going
through all of them and returning the last one, it effectively
changed the result returned by that function in some rare cases and
that led to problems (the switch from a "pre-order" to a "post-order"
callback was supposed to prevent that from happening, but it was
ineffective).
As it turns out, the systems where the change made by commit 33f767d actually matters are those where there are multiple ACPI
device objects representing the same PCIe port (which effectively
is a bridge). Moreover, only one of them, and the one we are
expected to use, has child device objects in the ACPI namespace,
so the regression can be addressed as described above.
References: https://bugzilla.kernel.org/show_bug.cgi?id=60561 Reported-by: Peter Wu <lekensteyn@gmail.com> Tested-by: Vladimir Lalov <mail@vlalov.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Cc: Peter Wu <lekensteyn@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Once do_acpi_find_child() has found the first matching handle, it
makes the acpi_get_child() loop stop and return that handle. On some
platforms, though, there are multiple devices with the same value of
"_ADR" in the same namespace scope, and if one of them is enabled,
the others will be disabled. For example:
If DEV0 and DEV1 are disabled and DEV2 is enabled, the handle of DEV2
should be returned, but actually the function always returns the
handle of DEV0.
To address that issue, make do_acpi_find_child() evaluate _STA to
check the device status. If a matching device object exists, but is
disabled, acpi_get_child() will continue to walk the namespace in the
hope of finding an enabled one. If one is found, its handle will be
returned, but otherwise the function will return the handle of the
disabled object found before (in case it is enabled going forward).
[rjw: Changelog] Signed-off-by: Jeff Wu <zlinuxkernel@gmail.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Peter Wu <lekensteyn@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
TX status notification can get lost, or the frames could
get stuck on the queue, so don't wait for the callback
from the driver forever and instead time out after half
a second.
Any uaccess between guest_enter and guest_exit could trigger a page fault,
the page fault handler would handle it as a guest fault and translate a
user address as guest address.
Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Johannes Berg <johannes.berg@intel.com> Cc: Andrei Otcheretianski <andrei.otcheretianski@intel.com> Cc: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When jbd2_journal_dirty_metadata() returns error,
__ext4_handle_dirty_metadata() stops the handle. However callers of this
function do not count with that fact and still happily used now freed
handle. This use after free can result in various issues but very likely
we oops soon.
The motivation of adding __ext4_journal_stop() into
__ext4_handle_dirty_metadata() in commit 9ea7a0df seems to be only to
improve error reporting. So replace __ext4_journal_stop() with
ext4_journal_abort_handle() which was there before that commit and add
WARN_ON_ONCE() to dump stack to provide useful information.
Reported-by: Sage Weil <sage@inktank.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In file included from fs/exec.c:61:0:
arch/s390/include/asm/tlb.h:35:23: error: expected identifier or '(' before 'unsigned'
arch/s390/include/asm/tlb.h:36:1: warning: no semicolon at end of struct or union [enabled by default]
arch/s390/include/asm/tlb.h: In function 'tlb_gather_mmu':
arch/s390/include/asm/tlb.h:57:5: error: 'struct mmu_gather' has no member named 'end'
Broken due to commit 2b047252d0 ("Fix TLB gather virtual address range
invalidation corner cases").
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
[ Oh well. We had build testing for ppc amd um, but no s390 - Linus ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
As pointed out by Andreas Schwab, pointers passed to ARAnyM NatFeat calls
should be physical addresses, not virtual addresses.
Fortunately on Atari, physical and virtual kernel addresses are the same,
as long as normal kernel memory is concerned, so this usually worked fine
without conversion.
But for modules, pointers to literal strings are located in vmalloc()ed
memory. Depending on the version of ARAnyM, this causes the nf_get_id()
call to just fail, or worse, crash ARAnyM itself with e.g.
Gotcha! Illegal memory access. Atari PC = $968c
This is a big issue for distro kernels, who want to have all drivers as
loadable modules in an initrd.
Add a wrapper for nf_get_id() that copies the literal to the stack to
work around this issue.
As diagnosed by Andreas, fs/btrfs/volumes.c:__btrfs_map_block()
calls
do_div(stripe_nr, stripe_len);
with stripe_len u64, while do_div() assumes the divisor is a 32-bit number.
Due to the lack of truncation in the m68k-specific implementation of
do_div(), the division is performed using the upper 32-bit word of
stripe_len, which is zero.
This was introduced by commit 53b381b3abeb86f12787a6c40fee9b2f71edc23b
("Btrfs: RAID5 and RAID6"), which changed the divisor from
map->stripe_len (struct map_lookup.stripe_len is int) to a 64-bit temporary.
It is possible to construct an event group with a software event as a
group leader and then subsequently add a hardware event to the group.
This results in the event group being validated by adding all members
of the group to a fake PMU and attempting to allocate each event on
their respective PMU.
Unfortunately, for software events wthout a corresponding arm_pmu, this
results in a kernel crash attempting to dereference the ->get_event_idx
function pointer.
This patch fixes the problem by checking explicitly for software events
and ignoring those in event validation (since they can always be
scheduled). We will probably want to revisit this for 3.12, since the
validation checks don't appear to work correctly when dealing with
multiple hardware PMUs anyway.
Reported-by: Vince Weaver <vincent.weaver@maine.edu> Tested-by: Vince Weaver <vincent.weaver@maine.edu> Tested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
"Since v3.7.2 on two independent machines a very specific Git
repository fails in 9/10 cases on git-fsck due to an SHA1/memory
failures. This only occurs on a very specific repository and can be
reproduced stably on two independent laptops. Git mailing list ran
out of ideas and for me this looks like some very exotic kernel issue"
and bisected the failure to the backport of commit 53a59fc67f97 ("mm:
limit mmu_gather batching to fix soft lockups on !CONFIG_PREEMPT").
That commit itself is not actually buggy, but what it does is to make it
much more likely to hit the partial TLB invalidation case, since it
introduces a new case in tlb_next_batch() that previously only ever
happened when running out of memory.
The real bug is that the TLB gather virtual memory range setup is subtly
buggered. It was introduced in commit 597e1c3580b7 ("mm/mmu_gather:
enable tlb flush range in generic mmu_gather"), and the range handling
was already fixed at least once in commit e6c495a96ce0 ("mm: fix the TLB
range flushed when __tlb_remove_page() runs out of slots"), but that fix
was not complete.
The problem with the TLB gather virtual address range is that it isn't
set up by the initial tlb_gather_mmu() initialization (which didn't get
the TLB range information), but it is set up ad-hoc later by the
functions that actually flush the TLB. And so any such case that forgot
to update the TLB range entries would potentially miss TLB invalidates.
Rather than try to figure out exactly which particular ad-hoc range
setup was missing (I personally suspect it's the hugetlb case in
zap_huge_pmd(), which didn't have the same logic as zap_pte_range()
did), this patch just gets rid of the problem at the source: make the
TLB range information available to tlb_gather_mmu(), and initialize it
when initializing all the other tlb gather fields.
This makes the patch larger, but conceptually much simpler. And the end
result is much more understandable; even if you want to play games with
partial ranges when invalidating the TLB contents in chunks, now the
range information is always there, and anybody who doesn't want to
bother with it won't introduce subtle bugs.
Ben verified that this fixes his problem.
Reported-bisected-and-tested-by: Ben Tebulin <tebulin@googlemail.com> Build-testing-by: Stephen Rothwell <sfr@canb.auug.org.au> Build-testing-by: Richard Weinberger <richard.weinberger@gmail.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Acked-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch fixes a kernel panic that can occur when disconnecting a
wireless USB->serial device. When the serial device disconnects, the
device cleanup procedure ends up calling usb_hcd_disable_endpoint on the
serial device's endpoints. The wusbcore uses the ABORT_RPIPE command to
abort all transfers on the given endpoint but it does not properly give
back the URBs when the transfer results return from the HWA. This patch
prevents the transfer result processing code from bailing out when it sees
a WA_XFER_STATUS_ABORTED result code so that these urbs are flushed
properly by usb_hcd_disable_endpoint. It also updates wa_urb_dequeue to
handle the case where the endpoint has already been cleaned up when
usb_kill_urb is called which is where the panic originally occurred.
Signed-off-by: Thomas Pugliese <thomas.pugliese@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
pm_qos_update_request_timeout() updates a qos and then schedules
a delayed work item to bring the qos back down to the default
after the timeout. When the work item runs, pm_qos_work_fn() will
call pm_qos_update_request() and deadlock because it tries to
cancel itself via cancel_delayed_work_sync(). Future callers of
that qos will also hang waiting to cancel the work that is
canceling itself. Let's extract the little bit of code that does
the real work of pm_qos_update_request() and call it from the
work function so that we don't deadlock.
Before ed1ac6e (PM: don't use [delayed_]work_pending()) this didn't
happen because the work function wouldn't try to cancel itself.
[backport to 3.10 - gregkh]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Reviewed-by: Tejun Heo <tj@kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This fixes an issue where the bulk-in urb used for incoming data transfer
is not resubmitted if the packet recieved contains an error status. This
results in the driver locking until the port is closed and re-opened.
Tested on a custom board with a Cinterion GSM module.
Signed-off-by: Matt Burtch <matt@grid-net.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since commits 4005ad4390bf (EHCI: implement new semantics for
URB_ISO_ASAP) and c75c5ab575af (ALSA: USB: adjust for changed 3.8 USB
API) became widely distributed, people have been experiencing problems
with audio transfers. The slightest underrun causes complete failure,
requiring the audio stream to be restarted.
It turns out that the current isochronous API doesn't handle underruns
in the best way. The ALSA developers would much rather have transfers
that are submitted too late be accepted and complete in the normal
fashion, rather than being refused outright.
This patch implements the requested approach. When an isochronous URB
submission is so late that all its scheduled slots have already
expired, a debugging message will be printed in the log and the URB
will be accepted as usual. Assuming it was submitted by a completion
handler (which is normally the case), it will complete shortly
thereafter with all the usb_iso_packet_descriptor status fields marked
-EXDEV.
Make sure to fail properly if the device is not accepted during attach
in order to avoid null-pointer derefs (of missing interface private
data) at disconnect or release.
Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The parallel-port code of the drivers used a stack allocated
control-request buffer for asynchronous (and possibly deferred) control
requests. This not only violates the no-DMA-from-stack requirement but
could also lead to corrupt control requests being submitted.
Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix bug in device-type detection on big-endian machines originally
introduced by commit 0eafe4de ("USB: serial: mos7840: add support for
MCS7810 devices") which always matched on little-endian product ids.
Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix endianess bugs in firmware handling introduced by commits cb7a7c6a
("ti_usb_3410_5052: add Multi-Tech modem support") and 05a3d905
("ti_usb_3410_5052: support alternate firmware") which made the driver
use the wrong firmware for certain devices on big-endian machines.
Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This is similar to the race Linus had reported, but in this case
it's an older bug: nl80211_prepare_wdev_dump() uses the wiphy
index in cb->args[0] as it is and thus parses the message over
and over again instead of just once because 0 is the first valid
wiphy index. Similar code in nl80211_testmode_dump() correctly
offsets the wiphy_index by 1, do that here as well.
Reported-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We've added a fake mute control (setting the amp volume to zero) for
CX5051 at commit [3868137e: ALSA: hda - Add a fake mute feature], but
this feature was overlooked in the generic parser implementation. Now
the driver lacks of mute controls on these codecs.
The fix is just to check both AC_AMPCAP_MUTE and AC_AMPCAP_MIN_MUTE
bits in each place checking the amp capabilities.
Add the volume control quirk for avoiding the kernel warning
for the Logitech HD Webcam C525
as in the similar commit 36691e1be6ec551eef4a5225f126a281f8c051c2
for the Logitech HD Webcam C310.
Reported-by: Maksim Boyko <maksim.a.boyko@gmail.com> Tested-by: Maksim Boyko <maksim.a.boyko@gmail.com> Signed-off-by: Maksim Boyko <maksim.a.boyko@gmail.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The Tegra30 I2S driver was writing the AHUB interface parameters to the
playback path register rather than the capture path register. This
caused the capture parameters not to be configured at all, so if
capturing using non-HW-default parameters (e.g. 16-bit stereo rather
than 8-bit mono) the audio would be corrupted.
With this fixed, audio capture from an analog microphone works correctly
on the Cardhu board.
Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Mark Brown <broonie@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Beep Volume Min/Max was backwards.
Change to SOC_SONGLE_SX_TLV for correct volume representation
Signed-off-by: Brian Austin <brian.austin@cirrus.com> Signed-off-by: Mark Brown <broonie@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
list_first_entry() will always return a valid pointer, even if the list is
empty. So the check whether path is NULL will always be false. So we end up
calling dapm_create_or_share_mixmux_kcontrol() with a path struct that points
right in the middle of the widget struct and by trying to modify the path the
widgets memory will become corrupted. Fix this by using list_emtpy() to check if
the widget doesn't have any paths.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Tested-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Mark Brown <broonie@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When a P2P GO interface goes down, cfg80211 doesn't properly
tear it down, leading to warnings later. Add the GO interface
type to the enumeration to tear it down like AP interfaces.
Otherwise, we leave it pending and mac80211's state can get
very confused, leading to warnings later.
Reported-by: Ilan Peer <ilan.peer@intel.com> Tested-by: Ilan Peer <ilan.peer@intel.com> Reviewed-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When dumping generic netlink families, only the first dump call
is locked with genl_lock(), which protects the list of families,
and thus subsequent calls can access the data without locking,
racing against family addition/removal. This can cause a crash.
Fix it - the locking needs to be conditional because the first
time around it's already locked.
A similar bug was reported to me on an old kernel (3.4.47) but
the exact scenario that happened there is no longer possible,
on those kernels the first round wasn't locked either. Looking
at the current code I found the race described above, which had
also existed on the old kernel.
Reported-by: Andrei Otcheretianski <andrei.otcheretianski@intel.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix possibly wrong memcpy() bytes length since some CAN records received from
PCAN-USB could define a DLC field in range [9..15].
In that case, the real DLC value MUST be used to move forward the record pointer
but, only 8 bytes max. MUST be copied into the data field of the struct
can_frame object of the skb given to the network core.
Signed-off-by: Stephane Grosjean <s.grosjean@peak-system.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In case the AP has different regulatory information than we do,
it can happen that we connect to an AP based on e.g. the world
roaming regulatory data, and then update our database with the
AP's country information disables the channel the AP is using.
If this happens on an HT AP, the bandwidth tracking code will
hit the WARN_ON() and disconnect. Since that's not very useful,
ignore the channel-disable flag in bandwidth tracking.
Reported-by: Chris Wright <chrisw@sous-sol.org> Tested-by: Chris Wright <chrisw@sous-sol.org> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit "3d9646d mac80211: fix channel selection bug" introduced a possible
infinite loop by moving the out target above the chandef_downgrade
while loop. When we downgrade to NL80211_CHAN_WIDTH_20_NOHT, we jump
back up to re-run the while loop...indefinitely. Replace goto with
break and carry on. This may not be sufficient to connect to the AP,
but will at least keep the cpu from livelocking. Thanks to Derek Atkins
as an extra pair of debugging eyes.
Signed-off-by: Chris Wright <chrisw@sous-sol.org> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
While we're connected, the AP shouldn't change the primary channel
in the HT information. We checked this, and dropped the connection
if it did change it.
Unfortunately, this is causing problems on some APs, e.g. on the
Netgear WRT610NL: the beacons seem to always contain a bad channel
and if we made a connection using a probe response (correct data)
we drop the connection immediately and can basically not connect
properly at all.
Work around this by ignoring the HT primary channel information in
beacons if we're already connected.
Also print out more verbose messages in the other situations to
help diagnose similar bugs quicker in the future.
Acked-by: Andy Isaacson <adi@hexapodia.org> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Using rfkill switch can make firmware unstable, what cause various
Microcode errors and kernel warnings. Reseting firmware just after
rfkill off (radio on) helped with that.
If device was put into a sleep and system was restarted or module
reloaded, we have to wake device up before sending other commands.
Otherwise it will fail to start with Microcode error.
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com> Signed-off-by: John W. Linville <linville@tuxdriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Not saving PAR is an unfortunate oversight. If the guest performs
an AT* operation and gets scheduled out before reading the result
of the translation from PAR, it could become corrupted by another
guest or the host.
Saving this register is made slightly more complicated as KVM also
uses it on the permission fault handling path, leading to an ugly
"stash and restore" sequence. Fortunately, this is already a slow
path so we don't really care. Also, Linux doesn't do any AT*
operation, so Linux guests are not impacted by this bug.
[ Slightly tweaked to use an even register as first operand to ldrd
and strd operations in interrupts_head.S - Christoffer ]
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Jonghwan Choi <jhbird.choi@samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There's a race between elevator switching and normal io operation.
Because the allocation of struct elevator_queue and struct elevator_data
don't in a atomic operation.So there are have chance to use NULL
->elevator_data.
For example:
Thread A: Thread B
blk_queu_bio elevator_switch
spin_lock_irq(q->queue_block) elevator_alloc
elv_merge elevator_init_fn
Because call elevator_alloc, it can't hold queue_lock and the
->elevator_data is NULL.So at the same time, threadA call elv_merge and
nedd some info of elevator_data.So the crash happened.
Move the elevator_alloc into func elevator_init_fn, it make the
operations in a atomic operation.
Using the follow method can easy reproduce this bug
1:dd if=/dev/sdb of=/dev/null
2:while true;do echo noop > scheduler;echo deadline > scheduler;done
We typically update a task_group's shares within the dequeue/enqueue
path. However, continuously running tasks sharing a CPU are not
subject to these updates as they are only put/picked. Unfortunately,
when we reverted f269ae046 (in 17bc14b7), we lost the augmenting
periodic update that was supposed to account for this; resulting in a
potential loss of fairness.
To fix this, re-introduce the explicit update in
update_cfs_rq_blocked_load() [called via entity_tick()].
Reported-by: Max Hailperin <max@gustavus.edu> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Reviewed-by: Paul Turner <pjt@google.com> Link: http://lkml.kernel.org/n/tip-9545m3apw5d93ubyrotrj31y@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Recently we met quite a lot of random kernel panic issues after enabling
CONFIG_PROC_PAGE_MONITOR. After debuggind we found this has something
to do with following bug in pagemap:
pos is number of PM_ENTRY_BYTES in buffer, but len is the size of
buffer, it is a mistake to compare pos and len in add_page_map() for
checking buffer is full or not, and this can lead to buffer overflow and
random kernel panic issue.
Correct len to be total number of PM_ENTRY_BYTES in buffer.
When the stack is set to unlimited, the bottomup direction is used for
mmap-ings but the mmap_base is not used and thus effectively renders
ASLR for mmapings along with PIE useless.
Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Michel Lespinasse <walken@google.com> Cc: Oleg Nesterov <oleg@redhat.com> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Adrian Sendroiu <molecula2788@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix inadvertent breakage in the clone syscall ABI for Microblaze that
was introduced in commit f3268edbe6fe ("microblaze: switch to generic
fork/vfork/clone").
The Microblaze syscall ABI for clone takes the parent tid address in the
4th argument; the third argument slot is used for the stack size. The
incorrectly-used CLONE_BACKWARDS type assigned parent tid to the 3rd
slot.
This commit restores the original ABI so that existing userspace libc
code will work correctly.
All kernel versions from v3.8-rc1 were affected.
Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
struct memcg_cache_params has a union. Different parts of this union
are used for root and non-root caches. A part with destroying work is
used only for non-root caches.
I fixed the same problem in another place v3.9-rc1-16204-gf101a94, but
didn't notice this one.
John McCalpin reports that the "drs_data" and "ncb_data" QPI
uncore events are missing the "extra bit" and always return zero
values unless the bit is properly set.
More details from him:
According to the Xeon E5-2600 Product Family Uncore Performance
Monitoring Guide, Table 2-94, about 1/2 of the QPI Link Layer events
(including the ones that "perf" calls "drs_data" and "ncb_data") require
that the "extra bit" be set.
This was confusing for a while -- a note at the bottom of page 94 says
that the "extra bit" is bit 16 of the control register.
Unfortunately, Table 2-86 clearly says that bit 16 is reserved and must
be zero. Looking around a bit, I found that bit 21 appears to be the
correct "extra bit", and further investigation shows that "perf" actually
agrees with me:
[root@c560-003.stampede]# cat /sys/bus/event_source/devices/uncore_qpi_0/format/event
config:0-7,21
So the command
# perf -e "uncore_qpi_0/event=drs_data/"
Is the same as
# perf -e "uncore_qpi_0/event=0x02,umask=0x08/"
While it should be
# perf -e "uncore_qpi_0/event=0x102,umask=0x08/"
I confirmed that this last version gives results that agree with the
amount of data that I expected the STREAM benchmark to move across the QPI
link in the second (cross-chip) test of the original script.
Reported-by: John McCalpin <mccalpin@tacc.utexas.edu> Signed-off-by: Vince Weaver <vincent.weaver@maine.edu> Cc: zheng.z.yan@intel.com Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Cc: Paul Mackerras <paulus@samba.org> Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1308021037280.26119@vincent-weaver-1.um.maine.edu Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The GENERIC_PCI_IOMAP does not depend on CONFIG_PCI so move
it to the CONFIG_MIPS symbol so it's always selected for MIPS.
This fixes the missing pci_iomap declaration for MIPS.
Moreover, the pci_iounmap function was not defined in the
io.h header file if the CONFIG_PCI symbol is not set,
but it should since MIPS is not using CONFIG_GENERIC_IOMAP.
This fixes the following problem on a allyesconfig:
drivers/net/ethernet/3com/3c59x.c:1031:2: error: implicit declaration of
function 'pci_iomap' [-Werror=implicit-function-declaration]
drivers/net/ethernet/3com/3c59x.c:1044:3: error: implicit declaration of
function 'pci_iounmap' [-Werror=implicit-function-declaration]
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Acked-by: Steven J. Hill <Steven.Hill@imgtec.com>
Patchwork: https://patchwork.linux-mips.org/patch/5478/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Cc: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The omap2 nand device driver calls into the the elm code, which can
be a loadable module, and in that case it cannot be built-in itself.
I can see no reason why the omap2 driver cannot also be a module,
so let's make the option "tristate" in Kconfig to fix this allmodconfig
build error:
For r6xx+ asics. This mirrors the behavior of pre-r6xx
asics. We need to program the MC even if something
else in startup() fails. Failure to do so results in
an unusable GPU.
Based on a fix from: Mark Kettenis <kettenis@openbsd.org> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
[ rebased for 3.10 and dropped the drivers/gpu/drm/radeon/cik.c
bit as it's 3.11 specific code / tmb ] Signed-off-by: Thomas Backlund <tmb@mageia.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Otherwise just reinitialize from scratch on resume,
and so make it more likely to succeed.
v2: rebased for 3.10-stable tree
Signed-off-by: Christian König <christian.koenig@amd.com> Cc: stable@vger.kernel.org Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Removing the clock/power or resetting the VCPU can cause
hangs if that happens in the middle of a register write.
Stall the memory and register bus before putting the VCPU
into reset. Keep it in reset when unloading the module or
suspending.
v2: rebased on 3.10-stable tree
Signed-off-by: Christian König <christian.koenig@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since remove_proc_entry() started to wait for IO in progress (i.e.
since 2007 or so), the locking in fs/reiserfs/proc.c became wrong;
if procfs read happens between the moment when umount() locks the
victim superblock and removal of /proc/fs/reiserfs/<device>/*,
we'll get a deadlock - read will wait for s_umount (in sget(),
called by r_start()), while umount will wait in remove_proc_entry()
for that read to finish, holding s_umount all along.
Fortunately, the same change allows a much simpler race avoidance -
all we need to do is remove the procfs entries in the very beginning
of reiserfs ->kill_sb(); that'll guarantee that pointer to superblock
will remain valid for the duration for procfs IO, so we don't need
sget() to keep the sucker alive. As the matter of fact, we can
get rid of the home-grown iterator completely, and use single_open()
instead.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1. it wrongly assumes that !list_empty(d_subdirs) means that this
dir should be removed.
This is not that bad by itself, but:
2. if d_subdirs does not becomes empty after __debugfs_remove()
it gives up and silently fails, it doesn't even try to remove
other entries.
However ->d_subdirs can be non-empty because it still has the
already deleted !debugfs_positive() entries.
3. simple_release_fs() is called even if __debugfs_remove() fails.
Suppose we have
dir1/
dir2/
file2
file1
and someone opens dir1/dir2/file2.
Now, debugfs_remove_recursive(dir1/dir2) succeeds, and dir1/dir2 goes
away.
But debugfs_remove_recursive(dir1) silently fails and doesn't remove
this directory. Because it tries to delete (the already deleted)
dir1/dir2/file2 again and then fails due to "Avoid infinite loop"
logic.
And after that it is not possible to create another probe entry.
With this patch debugfs_remove_recursive() skips !debugfs_positive()
files although this is not strictly needed. The most important change
is that it does not try to make ->d_subdirs empty, it simply scans
the whole list(s) recursively and removes as much as possible.
The USB hub driver's event handler contains a check to catch SuperSpeed
devices that transitioned into the SS.Inactive state and tries to fix
them with a reset. It decides whether to do a plain hub port reset or
call the usb_reset_device() function based on whether there was a device
attached to the port.
However, there are device/hub combinations (found with a JetFlash
Transcend mass storage stick (8564:1000) on the root hub of an Intel
LynxPoint PCH) which can transition to the SS.Inactive state on
disconnect (and stay there long enough for the host to notice). In this
case, above-mentioned reset check will call usb_reset_device() on the
stale device data structure. The kernel will send pointless LPM control
messages to the no longer connected device address and can even cause
several 5 second khubd stalls on some (buggy?) host controllers, before
finally accepting the device's fate amongst a flurry of error messages.
This patch makes the choice of reset dependent on the port status that
has just been read from the hub in addition to the existence of an
in-kernel data structure for the device, and only proceeds with the more
extensive reset if both are valid.
Signed-off-by: Julius Werner <jwerner@chromium.org> Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
David reported that commit c2b93e06 (cifs: only set ops for inodes in
I_NEW state) caused a regression with mfsymlinks. Prior to that patch,
if a mfsymlink dentry was instantiated at readdir time, the inode would
get a new set of ops when it was revalidated. After that patch, this
did not occur.
This patch addresses this by simply skipping instantiating dentries in
the readdir codepath when we know that they will need to be immediately
revalidated. The next attempt to use that dentry will cause a new lookup
to occur (which is basically what we want to happen anyway).
Reported-and-Tested-by: David McBride <dwm37@cam.ac.uk> Cc: "Stefan (metze) Metzmacher" <metze@samba.org> Cc: Sachin Prabhu <sprabhu@redhat.com> Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Steve French <smfrench@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
For cifs_set_cifscreds() in "fs/cifs/connect.c", 'desc' buffer length
is 'CIFSCREDS_DESC_SIZE' (56 is less than 256), and 'ses->domainName'
length may be "255 + '\0'".
The related sprintf() may cause memory overflow, so need extend related
buffer enough to hold all things.
It is also necessary to be sure of 'ses->domainName' must be less than
256, and define the related macro instead of hard code number '256'.
Signed-off-by: Chen Gang <gang.chen@asianux.com> Reviewed-by: Jeff Layton <jlayton@redhat.com> Reviewed-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com> Reviewed-by: Scott Lovenberg <scott.lovenberg@gmail.com> Signed-off-by: Steve French <smfrench@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Previously we weren't swapping only some of the extent_status LRU
fields during the processing of the EXT4_IOC_SWAP_BOOT ioctl. The
much safer thing to do is to just completely flush the extent status
tree when doing the swap.
Commit 5688978 ("ext4: improve handling of conflicting mount options")
introduced incorrect messages shown while choosing wrong mount options.
First of all, both cases of incorrect mount options,
"data=journal,delalloc" and "data=journal,dioread_nolock" result in
the same error message.
Secondly, the problem above isn't solved for remount option: the
mismatched parameter is simply ignored. Moreover, ext4_msg states
that remount with options "data=journal,delalloc" succeeded, which is
not true.
To fix it up, I added a simple check after parse_options() call to
ensure that data=journal and delalloc/dioread_nolock parameters are
not present at the same time.
Signed-off-by: Piotr Sarna <p.sarna@partner.samsung.com> Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 26092bf ("ext4: use a table-driven handler for mount options")
wrongly disallows the specifying the mount options nodelalloc and
data=journal simultaneously. This is incorrect; it should have only
disallowed the combination of delalloc and data=journal
simultaneously.
Signed-off-by: Christian König <christian.koenig@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There are two audio dtos on radeon asics that you can
select between. Normally, dto0 is used for hdmi and
dto1 for DP, but it seems that the dto is somehow
tied to the encoders on DCE3 asics.
It takes an unsigned value. This happens not to blow up on 64-bit
architectures, but it does on 32-bit, causing
drm_calc_vbltimestamp_from_scanoutpos() to calculate totally bogus
timestamps for vblank events. Which in turn causes e.g. gnome-shell to
hang after a DPMS off cycle with current xf86-video-ati Git.
[airlied: regression introduced in drm: use monotonic time in drm_calc_vbltimestamp_from_scanoutpos]
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=59339
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=59836 Tested-by: shui yangwei <yangweix.shui@intel.com> Signed-off-by: Michel Dänzer <michel.daenzer@amd.com> Reviewed-by: Imre Deak <imre.deak@intel.com> Signed-off-by: Dave Airlie <airlied@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When a BO gets pinned the placement may get changed. If the memory is
mapped into user space and user space has already accessed the mapped
range the page tables are set up but now point to the wrong memory.
Set bo.mdev->dev_mapping in mgag200_bo_create() to make sure that
ttm_bo_unmap_virtual() called from ttm_bo_handle_move_mem() will take
care of this.
v2: Don't call ttm_bo_unmap_virtual() in mgag200_bo_pin(), fix comment.
This is a cirrus version of Egbert Eich's patch for mgag200.
Without bo.bdev->dev_mapping set, the ttm_bo_unmap_virtual_locked
called from ttm_bo_handle_move_mem returns with no effect. If any
application accessed the memory before it was moved, it will
access wrong memory next time. This causes crashes when changing
resolution down.
Signed-off-by: Michal Srb <msrb@suse.com> Signed-off-by: Dave Airlie <airlied@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If a port gets unplugged while a user is blocked on read(), -ENODEV is
returned. However, subsequent read()s returned 0, indicating there's no
host-side connection (but not indicating the device went away).
This also happened when a port was unplugged and the user didn't have
any blocking operation pending. If the user didn't monitor the SIGIO
signal, they won't have a chance to find out if the port went away.
Fix by returning -ENODEV on all read()s after the port gets unplugged.
write() already behaves this way.
Signed-off-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
SIGIO should be sent when a port gets unplugged. It should only be sent
to prcesses that have the port opened, and have asked for SIGIO to be
delivered. We were clearing out guest_connected before calling
send_sigio_to_port(), resulting in a sigio not getting sent to
processes.
Fix by setting guest_connected to false after invoking the sigio
function.
Signed-off-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We used to keep the port's char device structs and the /sys entries
around till the last reference to the port was dropped. This is
actually unnecessary, and resulted in buggy behaviour:
1. Open port in guest
2. Hot-unplug port
3. Hot-plug a port with the same 'name' property as the unplugged one
This resulted in hot-plug being unsuccessful, as a port with the same
name already exists (even though it was unplugged).
This behaviour resulted in a warning message like this one:
Instead of relying on guest applications to release all references to
the ports, we should go ahead and unregister the port from all the core
layers. Any open/read calls on the port will then just return errors,
and an unplug/plug operation on the host will succeed as expected.
This also caused buggy behaviour in case of the device removal (not just
a port): when the device was removed (which means all ports on that
device are removed automatically as well), the ports with active
users would clean up only when the last references were dropped -- and
it would be too late then to be referencing char device pointers,
resulting in oopses:
Between open() being called and processed, the port can be unplugged.
Check if this happened, and bail out.
A simple test script to reproduce this is:
while true; do for i in $(seq 1 100); do echo $i > /dev/vport0p3; done; done;
This opens and closes the port a lot of times; unplugging the port while
this is happening triggers the bug.
Signed-off-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>