Commit 0cb64249ca ("firmware_loader: abort request if wait_for_completion
is interrupted") added via 4.0 added support to abort the fallback mechanism
when a signal was detected and wait_for_completion_interruptible() returned
-ERESTARTSYS -- for instance when a user hits CTRL-C. The abort was overly
*too* effective.
When a child process terminates (successful or not) the signal SIGCHLD can
be sent to the parent process which ran the child in the background and
later triggered a sync request for firmware through a sysfs interface which
relies on the fallback mechanism. This signal in turn can be recieved by the
interruptible wait we constructed on firmware_class and detects it as an
abort *before* userspace could get a chance to write the firmware. Upon
failure -EAGAIN is returned, so userspace is also kept in the dark about
exactly what happened.
We can reproduce the issue with the fw_fallback.sh selftest:
Before this patch:
$ sudo tools/testing/selftests/firmware/fw_fallback.sh
...
tools/testing/selftests/firmware/fw_fallback.sh: error - sync firmware request cancelled due to SIGCHLD
After this patch:
$ sudo tools/testing/selftests/firmware/fw_fallback.sh
...
tools/testing/selftests/firmware/fw_fallback.sh: SIGCHLD on sync ignored as expected
Fix this by making the wait killable -- only killable by SIGKILL (kill -9).
We loose the ability to allow userspace to cancel a write with CTRL-C
(SIGINT), however its been decided the compromise to require SIGKILL is
worth the gains.
Chances of this issue occuring are low due to the number of drivers upstream
exclusively relying on the fallback mechanism for firmware (2 drivers),
however this is observed in the field with custom drivers with sysfs
triggers to load firmware. Only distributions relying on the fallback
mechanism are impacted as well. An example reported issue was on Android,
as follows:
1) Android init (pid=1) fork()s (say pid=42) [this child process is totally
unrelated to firmware loading, it could be sleep 2; for all we care ]
2) Android init (pid=1) does a write() on a (driver custom) sysfs file which
ends up calling request_firmware() kernel side
3) The firmware loading fallback mechanism is used, the request is sent to
userspace and pid 1 waits in the kernel on wait_*
4) before firmware loading completes pid 42 dies (for any reason, even
normal termination)
5) Kernel delivers SIGCHLD to pid=1 to tell it a child has died, which
causes -ERESTARTSYS to be returned from wait_*
6) The kernel's wait aborts and return -EAGAIN for the
request_firmware() caller.
Cc: stable <stable@vger.kernel.org> # 4.0
Fixes: 0cb64249ca ("firmware_loader: abort request if wait_for_completion is interrupted")
Suggested-by: "Eric W. Biederman" <ebiederm@xmission.com>
Suggested-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Tested-by: Martin Fuzzey <mfuzzey@parkeon.com>
Reported-by: Martin Fuzzey <mfuzzey@parkeon.com>
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix batched requests from waiting forever on failure.
The firmware API batched requests feature has been broken since the API call
request_firmware_direct() was introduced on commit bba3a87e98 ("firmware:
Introduce request_firmware_direct()"), added on v3.14 *iff* the firmware
being requested was not present in *certain kernel builds* [0].
When no firmware is found the worker which goes on to finish never informs
waiters queued up of this, so any batched request will stall in what seems
to be forever (MAX_SCHEDULE_TIMEOUT). Sadly, a reboot will also stall, as
the reboot notifier was only designed to kill custom fallback workers. The
issue seems to the user as a type of soft lockup, what *actually* happens
underneath the hood is a wait call which never completes as we failed to
issue a completion on error.
For device drivers with optional firmware schemes (ie, Intel iwlwifi, or
Netronome -- even though it uses request_firmware() and not
request_firmware_direct()), this could mean that when you boot a system with
multiple cards the firmware will seem to never load on the system, or that
the card is just not responsive even the driver initialization. Due to
differences in scheduling possible this should not always trigger --
one would need to to ensure that multiple requests are in place at the
right time for this to work, also release_firmware() must not be called
prior to any other incoming request. The complexity may not be worth
supporting batched requests in the future given the wait mechanism is
only used also for the fallback mechanism. We'll keep it for now and
just fix it.
Its reported that at least with the Intel WiFi cards on one system this
issue was creeping up 50% of the boots [0].
Before this commit batched requests testing revealed:
============================================================================
CONFIG_FW_LOADER_USER_HELPER_FALLBACK=n
CONFIG_FW_LOADER_USER_HELPER=y
Most common Linux distribution setup.
API-type no-firmware-found firmware-found
----------------------------------------------------------------------
request_firmware() FAIL OK
request_firmware_direct() FAIL OK
request_firmware_nowait(uevent=true) FAIL OK
request_firmware_nowait(uevent=false) FAIL OK
============================================================================
CONFIG_FW_LOADER_USER_HELPER_FALLBACK=n
CONFIG_FW_LOADER_USER_HELPER=n
Only possible if CONFIG_DELL_RBU=n and CONFIG_LEDS_LP55XX_COMMON=n, rare.
API-type no-firmware-found firmware-found
----------------------------------------------------------------------
request_firmware() FAIL OK
request_firmware_direct() FAIL OK
request_firmware_nowait(uevent=true) FAIL OK
request_firmware_nowait(uevent=false) FAIL OK
============================================================================
CONFIG_FW_LOADER_USER_HELPER_FALLBACK=y
CONFIG_FW_LOADER_USER_HELPER=y
Google Android setup.
API-type no-firmware-found firmware-found
----------------------------------------------------------------------
request_firmware() OK OK
request_firmware_direct() FAIL OK
request_firmware_nowait(uevent=true) OK OK
request_firmware_nowait(uevent=false) OK OK
============================================================================
Ater this commit batched testing results:
============================================================================
CONFIG_FW_LOADER_USER_HELPER_FALLBACK=n
CONFIG_FW_LOADER_USER_HELPER=y
Most common Linux distribution setup.
API-type no-firmware-found firmware-found
----------------------------------------------------------------------
request_firmware() OK OK
request_firmware_direct() OK OK
request_firmware_nowait(uevent=true) OK OK
request_firmware_nowait(uevent=false) OK OK
============================================================================
CONFIG_FW_LOADER_USER_HELPER_FALLBACK=n
CONFIG_FW_LOADER_USER_HELPER=n
Only possible if CONFIG_DELL_RBU=n and CONFIG_LEDS_LP55XX_COMMON=n, rare.
API-type no-firmware-found firmware-found
----------------------------------------------------------------------
request_firmware() OK OK
request_firmware_direct() OK OK
request_firmware_nowait(uevent=true) OK OK
request_firmware_nowait(uevent=false) OK OK
============================================================================
CONFIG_FW_LOADER_USER_HELPER_FALLBACK=y
CONFIG_FW_LOADER_USER_HELPER=y
Google Android setup.
API-type no-firmware-found firmware-found
----------------------------------------------------------------------
request_firmware() OK OK
request_firmware_direct() OK OK
request_firmware_nowait(uevent=true) OK OK
request_firmware_nowait(uevent=false) OK OK
============================================================================
[0] https://bugzilla.kernel.org/show_bug.cgi?id=195477
Cc: stable <stable@vger.kernel.org> # v3.14
Fixes: bba3a87e98 ("firmware: Introduce request_firmware_direct()"
Reported-by: Nicolas <nbroeking@me.com>
Reported-by: John Ewalt <jewalt@lgsinnovations.com>
Reported-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The firmware cache mechanism serves two purposes, the secondary purpose is
not well documented nor understood. This fixes a regression with the
secondary purpose of the firmware cache mechanism: batched requests on
successful lookups. Without this fix *any* time a batched request is
triggered, secondary requests for which the batched request mechanism
was designed for will seem to last forver and seem to never return.
This issue is present for all kernel builds possible, and a hard reset
is required.
The firmware cache is used for:
1) Addressing races with file lookups during the suspend/resume cycle
by keeping firmware in memory during the suspend/resume cycle
2) Batched requests for the same file rely only on work from the first file
lookup, which keeps the firmware in memory until the last
release_firmware() is called
Batched requests *only* take effect if secondary requests come in prior to
the first user calling release_firmware(). The devres name used for the
internal firmware cache is used as a hint other pending requests are
ongoing, the firmware buffer data is kept in memory until the last user of
the buffer calls release_firmware(), therefore serializing requests and
delaying the release until all requests are done.
Batched requests wait for a wakup or signal so we can rely on the first file
fetch to write to the pending secondary requests. Commit 5b02962494
("firmware: do not use fw_lock for fw_state protection") ported the firmware
API to use swait, and in doing so failed to convert complete_all() to
swake_up_all() -- it used swake_up(), loosing the ability for *some* batched
requests to take effect.
We *could* fix this by just using swake_up_all() *but* swait is now known
to be very special use case, so its best to just move away from it. So we
just go back to using completions as before commit 5b02962494 ("firmware:
do not use fw_lock for fw_state protection") given this was using
complete_all().
Without this fix it has been reported plugging in two Intel 6260 Wifi cards
on a system will end up enumerating the two devices only 50% of the time
[0]. The ported swake_up() should have actually handled the case with two
devices, however, *if more than two cards are used* the swake_up() would
not have sufficed. This change is only part of the required fixes for
batched requests. Another fix is provided in the next patch.
This particular change should fix the cases where more than three requests
with the same firmware name is used, otherwise batched requests will wait
for MAX_SCHEDULE_TIMEOUT and just timeout eventually.
Below is a summary of tests triggering batched requests on different
kernel builds.
Before this patch:
============================================================================
CONFIG_FW_LOADER_USER_HELPER_FALLBACK=n
CONFIG_FW_LOADER_USER_HELPER=y
Most common Linux distribution setup.
API-type no-firmware-found firmware-found
----------------------------------------------------------------------
request_firmware() FAIL FAIL
request_firmware_direct() FAIL FAIL
request_firmware_nowait(uevent=true) FAIL FAIL
request_firmware_nowait(uevent=false) FAIL FAIL
============================================================================
CONFIG_FW_LOADER_USER_HELPER_FALLBACK=n
CONFIG_FW_LOADER_USER_HELPER=n
Only possible if CONFIG_DELL_RBU=n and CONFIG_LEDS_LP55XX_COMMON=n, rare.
API-type no-firmware-found firmware-found
----------------------------------------------------------------------
request_firmware() FAIL FAIL
request_firmware_direct() FAIL FAIL
request_firmware_nowait(uevent=true) FAIL FAIL
request_firmware_nowait(uevent=false) FAIL FAIL
============================================================================
CONFIG_FW_LOADER_USER_HELPER_FALLBACK=y
CONFIG_FW_LOADER_USER_HELPER=y
Google Android setup.
API-type no-firmware-found firmware-found
----------------------------------------------------------------------
request_firmware() FAIL FAIL
request_firmware_direct() FAIL FAIL
request_firmware_nowait(uevent=true) FAIL FAIL
request_firmware_nowait(uevent=false) FAIL FAIL
============================================================================
After this patch:
============================================================================
CONFIG_FW_LOADER_USER_HELPER_FALLBACK=n
CONFIG_FW_LOADER_USER_HELPER=y
Most common Linux distribution setup.
API-type no-firmware-found firmware-found
----------------------------------------------------------------------
request_firmware() FAIL OK
request_firmware_direct() FAIL OK
request_firmware_nowait(uevent=true) FAIL OK
request_firmware_nowait(uevent=false) FAIL OK
============================================================================
CONFIG_FW_LOADER_USER_HELPER_FALLBACK=n
CONFIG_FW_LOADER_USER_HELPER=n
Only possible if CONFIG_DELL_RBU=n and CONFIG_LEDS_LP55XX_COMMON=n, rare.
API-type no-firmware-found firmware-found
----------------------------------------------------------------------
request_firmware() FAIL OK
request_firmware_direct() FAIL OK
request_firmware_nowait(uevent=true) FAIL OK
request_firmware_nowait(uevent=false) FAIL OK
============================================================================
CONFIG_FW_LOADER_USER_HELPER_FALLBACK=y
CONFIG_FW_LOADER_USER_HELPER=y
Google Android setup.
API-type no-firmware-found firmware-found
----------------------------------------------------------------------
request_firmware() OK OK
request_firmware_direct() FAIL OK
request_firmware_nowait(uevent=true) OK OK
request_firmware_nowait(uevent=false) OK OK
============================================================================
[0] https://bugzilla.kernel.org/show_bug.cgi?id=195477
CC: <stable@vger.kernel.org> [4.10+]
Cc: Ming Lei <ming.lei@redhat.com>
Fixes: 5b02962494 ("firmware: do not use fw_lock for fw_state protection")
Reported-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This adds a new ATEN device id for a new pl2303-based device.
Reported-by: Peter Kuo <PeterKuo@aten.com.tw>
Cc: stable <stable@vger.kernel.org>
Cc: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Moshi USB to Ethernet Adapter internally uses a Genesys Logic hub to
connect to Realtek r8153.
The Realtek r8153 ethernet does not work on the internal hub, no-lpm quirk
can make it work.
Since another r8153 dongle at my hand does not have the issue, so add
the quirk to the Genesys Logic hub instead.
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Some buggy USB disk adapters disconnect and reconnect multiple times
during the enumeration procedure. This may lead to a device
connecting at full speed instead of high speed, because when the USB
stack sees that a device isn't able to enumerate at high speed, it
tries to hand the connection over to a full-speed companion
controller.
The logic for doing this is careful to check that the device is still
connected. But this check is inadequate if the device disconnects and
reconnects before the check is done. The symptom is that a device
works, but much more slowly than it is capable of operating.
The situation was made worse recently by commit 22547c4cc4 ("usb:
hub: Wait for connection to be reestablished after port reset"), which
increases the delay following a reset before a disconnect is
recognized, thus giving the device more time to reconnect.
This patch makes the check more robust. If the device was
disconnected at any time during enumeration, we will now skip the
full-speed handover.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-and-tested-by: Zdenek Kabelac <zkabelac@redhat.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Certain HP keyboards would keep inputting a character automatically which
is the wake-up key after S3 resume
On some AMD platforms USB host fails to respond (by holding resume-K) to
USB device (an HP keyboard) resume request within 1ms (TURSM) and ensures
that resume is signaled for at least 20 ms (TDRSMDN), which is defined in
USB 2.0 spec. The result is that the keyboard is out of function.
In SNPS USB design, the host responds to the resume request only after
system gets back to S0 and the host gets to functional after the internal
HW restore operation that is more than 1 second after the initial resume
request from the USB device.
As a workaround for specific keyboard ID(HP Keyboards), applying port reset
after resume when the keyboard is plugged in.
Signed-off-by: Sandeep Singh <Sandeep.Singh@amd.com>
Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
cc: Nehal Shah <Nehal-bakulchandra.Shah@amd.com>
Reviewed-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The numd field of directive receive command takes number of dwords to
transfer. This fix has the correct calculation for numd.
Signed-off-by: Kwan (Hingkwan) Huen-SSI <kwan.huen@samsung.com>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Christoph Hellwig <hch@lst.de>
We need to return an error if a timeout occurs on any NVMe command during
initialization. Without this, the nvme reset work will be stuck. A timeout
will have a negative error code, meaning we need to stop initializing
the controller. All postitive returns mean the controller is still usable.
bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=196325
Signed-off-by: Keith Busch <keith.busch@intel.com>
Cc: Martin Peres <martin.peres@intel.com>
[jth consolidated cleanup path ]
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Pull networking fixes from David Miller:
1) Fix handling of initial STATE message in TIPC, from Jon Paul Maloy.
2) Fix stats handling in bcm_sysport_get_stats(), from Florian
Fainelli.
3) Reject 16777215 VNI value in geneve_validate(), from Girish
Moodalbail.
4) Fix initial IGMP sysctl setting regression, from Nikolay Borisov.
5) Once a UFO fragmented frame is treated as UFO, we should continue
doing so. Likewise once a frame has been segmented, we should
continue doing that and not try to convert it to a UFO frame. From
Willem de Bruijn.
6) Test the AF_PACKET RX/TX ring pg_vec state under the socket lock to
prevent races. From Willem de Bruijn.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
packet: fix tp_reserve race in packet_set_ring
udp: consistently apply ufo or fragmentation
net: sched: set xt_tgchk_param par.nft_compat as 0 in ipt_init_target
igmp: Fix regression caused by igmp sysctl namespace code.
geneve: maximum value of VNI cannot be used
net: systemport: Fix software statistics for SYSTEMPORT Lite
tipc: remove premature ESTABLISH FSM event at link synchronization
Updates to tp_reserve can race with reads of the field in
packet_set_ring. Avoid this by holding the socket lock during
updates in setsockopt PACKET_RESERVE.
This bug was discovered by syzkaller.
Fixes: 8913336a7e ("packet: add PACKET_RESERVE sockopt")
Reported-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When iteratively building a UDP datagram with MSG_MORE and that
datagram exceeds MTU, consistently choose UFO or fragmentation.
Once skb_is_gso, always apply ufo. Conversely, once a datagram is
split across multiple skbs, do not consider ufo.
Sendpage already maintains the first invariant, only add the second.
IPv6 does not have a sendpage implementation to modify.
A gso skb must have a partial checksum, do not follow sk_no_check_tx
in udp_send_skb.
Found by syzkaller.
Fixes: e89e9cf539 ("[IPv4/IPv6]: UFO Scatter-gather approach")
Reported-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull sparc updates from David Miller:
1) Recognize M8 cpus, just basic chip ID matching, from Allen Pais.
2) Prevent crashes when bringing up sunvdc virtual block devices in
some environments. From Jim Quigley.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc:
sunvdc: prevent sunvdc panic when mpgroup disk added to guest domain
sparc64: Increase max_phys_bits to 51 and VA bits to 53 for M8.
sparc64: recognize and support sparc M8 cpu type
sparc64: properly name the cpu constants
Currently we create the sysfs entry even if we fail mapping
it. In that case, the unmapping will not remove the sysfs created
file. There is no good reason to create a sysfs entry for a non
working CMB and show his characteristics.
Fixes: f63572dff ("nvme: unmap CMB and remove sysfs file in reset path")
Signed-off-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Stephen Bates <sbates@raithlin.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Currently, calls to nvmet_fc_rcv_fcp_req() always copied the
FC-NVME cmd iu to a temporary buffer before returning, allowing
the driver to immediately repost the buffer to the hardware.
To address timing conditions on queue element structures vs async
command reception, the nvmet_fc transport occasionally may need to
hold on to the command iu buffer for a short period. In these cases,
the nvmet_fc_rcv_fcp_req() will return a special return code
(-EOVERFLOW). In these cases, the LLDD must delay until the new
defer_rcv lldd callback is called before recycling the buffer back
to the hw.
This patch adds support for the new nvmet_fc transport defer_rcv
callback and recognition of the new error code when passing commands
to the transport.
Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: James Smart <james.smart@broadcom.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
At queue creation, the transport allocates a local job struct
(struct nvmet_fc_fcp_iod) for each possible element of the queue.
When a new CMD is received from the wire, a jobs struct is allocated
from the queue and then used for the duration of the command.
The job struct contains buffer space for the wire command iu. Thus,
upon allocation of the job struct, the cmd iu buffer is copied to
the job struct and the LLDD may immediately free/reuse the CMD IU
buffer passed in the call.
However, in some circumstances, due to the packetized nature of FC
and the api of the FC LLDD which may issue a hw command to send the
wire response, but the LLDD may not get the hw completion for the
command and upcall the nvmet_fc layer before a new command may be
asynchronously received on the wire. In other words, its possible
for the initiator to get the response from the wire, thus believe a
command slot free, and send a new command iu. The new command iu
may be received by the LLDD and passed to the transport before the
LLDD had serviced the hw completion and made the teardown calls for
the original job struct. As such, there is no available job struct
available for the new io. E.g. it appears like the host sent more
queue elements than the queue size. It didn't based on it's
understanding.
Rather than treat this as a hard connection failure queue the new
request until the job struct does free up. As the buffer isn't
copied as there's no job struct, a special return value must be
returned to the LLDD to signify to hold off on recycling the cmd
iu buffer. And later, when a job struct is allocated and the
buffer copied, a new LLDD callback is introduced to notify the
LLDD and allow it to recycle it's command iu buffer.
Signed-off-by: James Smart <james.smart@broadcom.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Some broken controllers (such as earlier Linux targets) pad model or
serial fields with 0-bytes rather than spaces. The NVMe spec disallows
0 bytes in "ASCII" fields. Thus strip trailing 0-bytes, too. Also make
sure that we get no underflow for pathological input.
Signed-off-by: Martin Wilck <mwilck@suse.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Commit 55917a21d0 ("netfilter: x_tables: add context to know if
extension runs from nft_compat") introduced a member nft_compat to
xt_tgchk_param structure.
But it didn't set it's value for ipt_init_target. With unexpected
value in par.nft_compat, it may return unexpected result in some
target's checkentry.
This patch is to set all it's fields as 0 and only initialize the
non-zero fields in ipt_init_target.
v1->v2:
As Wang Cong's suggestion, fix it by setting all it's fields as
0 and only initializing the non-zero fields.
Fixes: 55917a21d0 ("netfilter: x_tables: add context to know if extension runs from nft_compat")
Suggested-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit dcd87999d4 ("igmp: net: Move igmp namespace init to correct file")
moved the igmp sysctls initialization from tcp_sk_init to igmp_net_init. This
function is only called as part of per-namespace initialization, only if
CONFIG_IP_MULTICAST is defined, otherwise igmp_mc_init() call in ip_init is
compiled out, casuing the igmp pernet ops to not be registerd and those sysctl
being left initialized with 0. However, there are certain functions, such as
ip_mc_join_group which are always compiled and make use of some of those
sysctls. Let's do a partial revert of the aforementioned commit and move the
sysctl initialization into inet_init_net, that way they will always have
sane values.
Fixes: dcd87999d4 ("igmp: net: Move igmp namespace init to correct file")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=196595
Reported-by: Gerardo Exequiel Pozzi <vmlinuz386@gmail.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Geneve's Virtual Network Identifier (VNI) is 24 bit long, so the range
of values for it would be from 0 to 16777215 (2^24 -1). However, one
cannot create a geneve device with VNI set to 16777215. This patch fixes
this issue.
Signed-off-by: Girish Moodalbail <girish.moodalbail@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
With SYSTEMPORT Lite we have holes in our statistics layout that make us
skip over the hardware MIB counters, bcm_sysport_get_stats() was not
taking that into account resulting in reporting 0 for all SW-maintained
statistics, fix this by skipping accordingly.
Fixes: 44a4524c54 ("net: systemport: Add support for SYSTEMPORT Lite")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When a link between two nodes come up, both endpoints will initially
send out a STATE message to the peer, to increase the probability that
the peer endpoint also is up when the first traffic message arrives.
Thereafter, if the establishing link is the second link between two
nodes, this first "traffic" message is a TUNNEL_PROTOCOL/SYNCH message,
helping the peer to perform initial synchronization between the two
links.
However, the initial STATE message may be lost, in which case the SYNCH
message will be the first one arriving at the peer. This should also
work, as the SYNCH message itself will be used to take up the link
endpoint before initializing synchronization.
Unfortunately the code for this case is broken. Currently, the link is
brought up through a tipc_link_fsm_evt(ESTABLISHED) when a SYNCH
arrives, whereupon __tipc_node_link_up() is called to distribute the
link slots and take the link into traffic. But, __tipc_node_link_up() is
itself starting with a test for whether the link is up, and if true,
returns without action. Clearly, the tipc_link_fsm_evt(ESTABLISHED) call
is unnecessary, since tipc_node_link_up() is itself issuing such an
event, but also harmful, since it inhibits tipc_node_link_up() to
perform the test of its tasks, and the link endpoint in question hence
is never taken into traffic.
This problem has been exposed when we set up dual links between pre-
and post-4.4 kernels, because the former ones don't send out the
initial STATE message described above.
We fix this by removing the unnecessary event call.
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Using mpgroup to define multiple paths for a virtual disk causes multiple
virtual-device-port ports to be created for that virtual device.
Each virtual-device-port port then gets a vdisk created for it by the Linux
sunvdc driver. As mpgroup is not supported by the Linux sunvdc driver it
cannot handle multiple ports for a single vdisk, leading to a kernel panic
at startup.
This fix prevents more than one vdisk per virtual-device-port being created
until full virtual disk multipathing (mpgroup) support is implemented.
Signed-off-by: Jim Quigley <Jim.Quigley@oracle.com>
Reviewed-by: Liam Merwick <liam.merwick@oracle.com>
Reviewed-by: Shannon Nelson <shannon.nelson@oracle.com>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Reviewed-by: Aaron Young <aaron.young@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The blk_mq_delay_kick_requeue_list() function is used by the device
mapper and only by the device mapper to rerun the queue and requeue
list after a delay. This function is called once per request that
gets requeued. Modify this function such that the queue is run once
per path change event instead of once per request that is requeued.
Fixes: commit 2849450ad3 ("blk-mq: introduce blk_mq_delay_kick_requeue_list()")
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Laurence Oberman <loberman@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This gets us back to the behavior in 4.12 and earlier.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Fixes: 7c20f116 ("bio-integrity: stop abusing bi_end_io")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
In dm-integrity target we register integrity profile that have
both generate_fn and verify_fn callbacks set to NULL.
This is used if dm-integrity is stacked under a dm-crypt device
for authenticated encryption (integrity payload contains authentication
tag and IV seed).
In this case the verification is done through own crypto API
processing inside dm-crypt; integrity profile is only holder
of these data. (And memory is owned by dm-crypt as well.)
After the commit (and previous changes)
Commit 7c20f11680
Author: Christoph Hellwig <hch@lst.de>
Date: Mon Jul 3 16:58:43 2017 -0600
bio-integrity: stop abusing bi_end_io
we get this crash:
: BUG: unable to handle kernel NULL pointer dereference at (null)
: IP: (null)
: *pde = 00000000
...
:
: Workqueue: kintegrityd bio_integrity_verify_fn
: task: f48ae180 task.stack: f4b5c000
: EIP: (null)
: EFLAGS: 00210286 CPU: 0
: EAX: f4b5debc EBX: 00001000 ECX: 00000001 EDX: 00000000
: ESI: 00001000 EDI: ed25f000 EBP: f4b5dee8 ESP: f4b5dea4
: DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
: CR0: 80050033 CR2: 00000000 CR3: 32823000 CR4: 001406d0
: Call Trace:
: ? bio_integrity_process+0xe3/0x1e0
: bio_integrity_verify_fn+0xea/0x150
: process_one_work+0x1c7/0x5c0
: worker_thread+0x39/0x380
: kthread+0xd6/0x110
: ? process_one_work+0x5c0/0x5c0
: ? kthread_worker_fn+0x100/0x100
: ? kthread_worker_fn+0x100/0x100
: ret_from_fork+0x19/0x24
: Code: Bad EIP value.
: EIP: (null) SS:ESP: 0068:f4b5dea4
: CR2: 0000000000000000
Patch just skip the whole verify workqueue if verify_fn is set to NULL.
Fixes: 7c20f116 ("bio-integrity: stop abusing bi_end_io")
Signed-off-by: Milan Broz <gmazyland@gmail.com>
[hch: trivial whitespace fix]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Fixes hitting WARN_ON() during initialisation of pre-NV50 GPUs, caused
by the recent changes to support pad macro routing on GM20x.
We currently don't use them here for older GPUs anyway.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Default config value for all other drivers is N.
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: Dave Airlie <airlied@redhat.com>
drm/i915 fixes for v4.13-rc5
* tag 'drm-intel-fixes-2017-08-09-1' of git://anongit.freedesktop.org/git/drm-intel:
drm/i915: fix backlight invert for non-zero minimum brightness
drm/i915/shrinker: Wrap need_resched() inside preempt-disable
drm/i915/perf: fix flex eu registers programming
drm/i915: Fix out-of-bounds array access in bdw_load_gamma_lut
drm/i915/gvt: Change the max length of mmio_reg_rw from 4 to 8
drm/i915/gvt: Initialize MMIO Block with HW state
drm/i915/gvt: clean workload queue if error happened
drm/i915/gvt: change resetting to resetting_eng
Core Changes:
- dma-buf: Allow multiple sync_files to wrap a single dma-fence (Chris)
Driver Changes:
- rockchip: misc fixes to vop driver from the downstream rockchip tree (Mark)
- Error path cleanups to tc358767 & host1x (Lucas & Paul, respectively)
* tag 'drm-misc-fixes-2017-08-08' of git://anongit.freedesktop.org/git/drm-misc:
drm/rockchip: vop: report error when check resource error
drm/rockchip: vop: round_up pitches to word align
drm/rockchip: vop: fix NV12 video display error
drm/rockchip: vop: fix iommu page fault when resume
dma-buf/sync_file: Allow multiple sync_files to wrap a single dma-fence
drm/bridge: tc358767: fix probe without attached output node
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1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=CUpE
-----END PGP SIGNATURE-----
Merge tag 'exynos-drm-fixes-for-v4.13-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/daeinki/drm-exynos into drm-fixes
Fix a issue to display system memory region outside a gem buffer.
* tag 'exynos-drm-fixes-for-v4.13-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/daeinki/drm-exynos:
drm/exynos: forbid creating framebuffers from too small GEM buffers
Bunch of msm fixes for 4.13
* 'msm-fixes-4.13-rc3' of git://people.freedesktop.org/~robclark/linux:
drm/msm: gpu: don't abuse dma_alloc for non-DMA allocations
drm/msm: gpu: call qcom_mdt interfaces only for ARCH_QCOM
drm/msm/adreno: Prevent unclocked access when retrieving timestamps
drm/msm: Remove __user from __u64 data types
drm/msm: args->fence should be args->flags
drm/msm: Turn off hardware clock gating before reading A5XX registers
drm/msm: Allow hardware clock gating to be toggled
drm/msm: Remove some potentially blocked register ranges
drm/msm/mdp5: Drop clock names with "_clk" suffix
drm/msm/mdp5: Fix typo in encoder_enable path
drm/msm: NULL pointer dereference in drivers/gpu/drm/msm/msm_gem_vma.c
drm/msm: fix WARN_ON in add_vma() with no iommu
drm/msm/dsi: Calculate link clock rates with updated dsi->lanes
drm/msm/mdp5: fix unclocked register access in _cursor_set()
drm/msm: unlock on error in msm_gem_get_iova()
drm/msm: fix an integer overflow test
drm/msm/mdp5: Fix compilation warnings
- Fix the documentation build as the docs were moved.
- Correct the UART pin list on the Intell Merrifield.
- Fix pin assignment and number of pins on the Marvell Armada
37xx pin controller.
- Cover the Setzer models in the Chromebook DMI quirk in the
Intel cheryview driver so they start working.
- Add the missing "sim" function to the sunxi driver.
- Fix USB pin definitions on Uniphier Pro4.
- Smatch fix for invalid reference in the zx pin control driver.
-----BEGIN PGP SIGNATURE-----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=Dyh5
-----END PGP SIGNATURE-----
Merge tag 'pinctrl-v4.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl
Pull pin control fixes from Linus Walleij:
"These are the pin control fixes I have gathered since the return from
my vacation. They boiled in -next a while so let's get them in.
Apart from the documentation build it is purely driver fixes. Which is
nice. The Intel fixes seem kind of important.
- Fix the documentation build as the docs were moved
- Correct the UART pin list on the Intel Merrifield
- Fix pin assignment and number of pins on the Marvell Armada 37xx
pin controller
- Cover the Setzer models in the Chromebook DMI quirk in the Intel
cheryview driver so they start working
- Add the missing "sim" function to the sunxi driver
- Fix USB pin definitions on Uniphier Pro4
- Smatch fix for invalid reference in the zx pin control driver"
* tag 'pinctrl-v4.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl:
pinctrl: generic: update references to Documentation/pinctrl.txt
pinctrl: intel: merrifield: Correct UART pin lists
pinctrl: armada-37xx: Fix number of pin in south bridge
pinctrl: armada-37xx: Fix the pin 23 on south bridge
pinctrl: cherryview: Add Setzer models to the Chromebook DMI quirk
pinctrl: sunxi: add a missing function of A10/A20 pinctrl driver
pinctrl: uniphier: fix USB3 pin assignment for Pro4
pinctrl: zte: fix dereference of 'data' in zx_set_mux()
Commit 65d8fc777f ("futex: Remove requirement for lock_page() in
get_futex_key()") removed an unnecessary lock_page() with the
side-effect that page->mapping needed to be treated very carefully.
Two defensive warnings were added in case any assumption was missed and
the first warning assumed a correct application would not alter a
mapping backing a futex key. Since merging, it has not triggered for
any unexpected case but Mark Rutland reported the following bug
triggering due to the first warning.
kernel BUG at kernel/futex.c:679!
Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 3695 Comm: syz-executor1 Not tainted 4.13.0-rc3-00020-g307fec773ba3 #3
Hardware name: linux,dummy-virt (DT)
task: ffff80001e271780 task.stack: ffff000010908000
PC is at get_futex_key+0x6a4/0xcf0 kernel/futex.c:679
LR is at get_futex_key+0x6a4/0xcf0 kernel/futex.c:679
pc : [<ffff00000821ac14>] lr : [<ffff00000821ac14>] pstate: 80000145
The fact that it's a bug instead of a warning was due to an unrelated
arm64 problem, but the warning itself triggered because the underlying
mapping changed.
This is an application issue but from a kernel perspective it's a
recoverable situation and the warning is unnecessary so this patch
removes the warning. The warning may potentially be triggered with the
following test program from Mark although it may be necessary to adjust
NR_FUTEX_THREADS to be a value smaller than the number of CPUs in the
system.
#include <linux/futex.h>
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/mman.h>
#include <sys/syscall.h>
#include <sys/time.h>
#include <unistd.h>
#define NR_FUTEX_THREADS 16
pthread_t threads[NR_FUTEX_THREADS];
void *mem;
#define MEM_PROT (PROT_READ | PROT_WRITE)
#define MEM_SIZE 65536
static int futex_wrapper(int *uaddr, int op, int val,
const struct timespec *timeout,
int *uaddr2, int val3)
{
syscall(SYS_futex, uaddr, op, val, timeout, uaddr2, val3);
}
void *poll_futex(void *unused)
{
for (;;) {
futex_wrapper(mem, FUTEX_CMP_REQUEUE_PI, 1, NULL, mem + 4, 1);
}
}
int main(int argc, char *argv[])
{
int i;
mem = mmap(NULL, MEM_SIZE, MEM_PROT,
MAP_SHARED | MAP_ANONYMOUS, -1, 0);
printf("Mapping @ %p\n", mem);
printf("Creating futex threads...\n");
for (i = 0; i < NR_FUTEX_THREADS; i++)
pthread_create(&threads[i], NULL, poll_futex, NULL);
printf("Flipping mapping...\n");
for (;;) {
mmap(mem, MEM_SIZE, MEM_PROT,
MAP_FIXED | MAP_SHARED | MAP_ANONYMOUS, -1, 0);
}
return 0;
}
Reported-and-tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org # 4.7+
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull i2c fixes from Wolfram Sang:
"The main thing is to allow empty id_tables for ACPI to make some
drivers get probed again. It looks a bit bigger than usual because it
needs some internal renaming, too.
Other than that, there is a fix for broken DSTDs, a super simple
enablement for ARM MPS, and two documentation fixes which I'd like to
see in v4.13 already"
* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
i2c: rephrase explanation of I2C_CLASS_DEPRECATED
i2c: allow i2c-versatile for ARM MPS platforms
i2c: designware: Some broken DSTDs use 1MiHz instead of 1MHz
i2c: designware: Print clock freq on invalid clock freq error
i2c: core: Allow empty id_table in ACPI case as well
i2c: mux: pinctrl: mention correct module name in Kconfig help text
Pull block fixes from Jens Axboe:
"Three patches that should go into this release.
Two of them are from Paolo and fix up some corner cases with BFQ, and
the last patch is from Ming and fixes up a potential usage count
imbalance regression due to the recent NOWAIT work"
* 'for-linus' of git://git.kernel.dk/linux-block:
blk-mq: don't leak preempt counter/q_usage_counter when allocating rq failed
block, bfq: consider also in_service_entity to state whether an entity is active
block, bfq: reset in_service_entity if it becomes idle
If the call to TEST_STATEID returns NFS4ERR_OLD_STATEID, then it just
means we raced with other calls to OPEN.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Pull crypto fixes from Herbert Xu:
"Fix two regressions in the inside-secure driver with respect to
hmac(sha1)"
* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
crypto: inside-secure - fix the sha state length in hmac_sha1_setkey
crypto: inside-secure - fix invalidation check in hmac_sha1_setkey
Pull networking fixes from David Miller:
"The pull requests are getting smaller, that's progress I suppose :-)
1) Fix infinite loop in CIPSO option parsing, from Yujuan Qi.
2) Fix remote checksum handling in VXLAN and GUE tunneling drivers,
from Koichiro Den.
3) Missing u64_stats_init() calls in several drivers, from Florian
Fainelli.
4) TCP can set the congestion window to an invalid ssthresh value
after congestion window reductions, from Yuchung Cheng.
5) Fix BPF jit branch generation on s390, from Daniel Borkmann.
6) Correct MIPS ebpf JIT merge, from David Daney.
7) Correct byte order test in BPF test_verifier.c, from Daniel
Borkmann.
8) Fix various crashes and leaks in ASIX driver, from Dean Jenkins.
9) Handle SCTP checksums properly in mlx4 driver, from Davide
Caratti.
10) We can potentially enter tcp_connect() with a cached route
already, due to fastopen, so we have to explicitly invalidate it.
11) skb_warn_bad_offload() can bark in legitimate situations, fix from
Willem de Bruijn"
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (52 commits)
net: avoid skb_warn_bad_offload false positives on UFO
qmi_wwan: fix NULL deref on disconnect
ppp: fix xmit recursion detection on ppp channels
rds: Reintroduce statistics counting
tcp: fastopen: tcp_connect() must refresh the route
net: sched: set xt_tgchk_param par.net properly in ipt_init_target
net: dsa: mediatek: add adjust link support for user ports
net/mlx4_en: don't set CHECKSUM_COMPLETE on SCTP packets
qed: Fix a memory allocation failure test in 'qed_mcp_cmd_init()'
hysdn: fix to a race condition in put_log_buffer
s390/qeth: fix L3 next-hop in xmit qeth hdr
asix: Fix small memory leak in ax88772_unbind()
asix: Ensure asix_rx_fixup_info members are all reset
asix: Add rx->ax_skb = NULL after usbnet_skb_return()
bpf: fix selftest/bpf/test_pkt_md_access on s390x
netvsc: fix race on sub channel creation
bpf: fix byte order test in test_verifier
xgene: Always get clk source, but ignore if it's missing for SGMII ports
MIPS: Add missing file for eBPF JIT.
bpf, s390: fix build for libbpf and selftest suite
...
When CPUs start and stop the watchdog, they manipulate shared data
that is normally protected by the lock. Other CPUs can be running
concurrently at this time, so it's a good idea to use locking here
to be on the safe side.
Remove the barrier which is undocumented and didn't do anything.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When the SMP detector finds other CPUs stuck, it iterates over
them and marks them as stuck. This pulls them out of the pending
mask and allows the detector to continue with remaining good
CPUs (if nmi_watchdog=panic is not enabled).
The code to dothat was buggy because when setting a CPU stuck,
if the pending mask became empty, it resets it to keep the
watchdog running. However the iterator will continue to run
over the new pending mask and mark remaining good CPUs sas stuck.
Fix this by doing it with cpumask bitwise operations.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When the watchdog decides to panic, it takes the lock and double
checks everything (to avoid races with the CPU being unstuck or
panic()ed by something else).
The exit label was misplaced and would result in all-CPUs backtrace
and watchdog panic even in the case that the condition was found to be
resolved.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Some code can go into a tight loop calling touch_nmi_watchdog (e.g.,
stop_machine CPU hotplug code). This can cause contention on watchdog
locks particularly if all CPUs with watchdog enabled are spinning in
the loops.
Avoid this storm of activity by running the watchdog timer callback
from this path if we have exceeded the timer period since it was last
run.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
- Hard-disable interrupts before taking the lock, which prevents
soft-NMI re-entrancy and therefore can prevent deadlocks.
- Use raw_ variants of local_irq_disable to avoid irq debugging.
- When the lock is contended, spin at low SMT priority, using
loads only, and with interrupts enabled (where possible).
Some stalls have been noticed at high loads that go away with improved
locking. There should not be so much locking contention in the first
place (which is addressed in a subsequent patch), but locking should
still be improved.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When the NMI IPI lock is contended, spin at low SMT priority, using
loads only, and with interrupts enabled (where possible). This
improves behaviour under high contention (e.g., a system crash when
a number of CPUs are trying to enter the debugger).
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Mika Westerberg