As pointed by recent post[1] on exploiting DRAM physical imperfection,
/proc/PID/pagemap exposes sensitive information which can be used to do
attacks.
This disallows anybody without CAP_SYS_ADMIN to read the pagemap.
commit 6ae9200f2cab7 ("enlarge console.name") increased the storage
for the console name to 16 bytes, but not the corresponding
struct console_cmdline::name storage. Console names longer than
8 bytes cause read beyond end-of-string and failure to match
console; I'm not sure if there are other unexpected consequences.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
For RoCE ports, we set the u32 PMA values based on u64 HCA counters. In case of
overflow, according to the IB spec, we have to saturate a counter to its
max value, do that.
Fixes: c37791349cc7 ('IB/mlx4: Support PMA counters for IBoE') Signed-off-by: Majd Dibbiny <majd@mellanox.com> Signed-off-by: Eran Ben Elisha <eranbe@mellanox.com> Signed-off-by: Hadar Hen Zion <hadarh@mellanox.com> Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Create constants that define the maximum and minimum values
representable by the kernel types u8, s8, u16, s16, and so on.
Signed-off-by: Alex Elder <elder@linaro.org> Cc: Sage Weil <sage@inktank.com> Cc: David Miller <davem@davemloft.net> 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>
The timeout entries are sizeof(int) rather than sizeof(long), which
means that when they were getting read we'd also leak kernel memory
to userspace along with the timeout values.
Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Max unacked packets/bytes is an int while sizeof(long) was used in the
sysctl table.
This means that when they were getting read we'd also leak kernel memory
to userspace along with the timeout values.
Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Compat function takes msgtyp argument as u32 and passes it down to
do_msgrcv which results in casting to long, thus the sign is lost and we
get a big positive number instead.
Cast the argument to signed type before passing it down.
Stable commit "core, nfqueue, openvswitch: Orphan frags in
skb_zerocopy and handle errors", upstream commit 36d5fe6a000790f56039afe26834265db0a3ad4c, was not correctly backported
and missed to change a const 'from' parameter to non-const. This
results in a new batch of warnings:
net/netfilter/nfnetlink_queue_core.c: In function ‘nfqnl_zcopy’:
net/netfilter/nfnetlink_queue_core.c:272:2: warning: passing argument 1 of ‘skb_orphan_frags’ discards ‘const’ qualifier from pointer target type [enabled by default]
if (unlikely(skb_orphan_frags(from, GFP_ATOMIC))) {
^
In file included from net/netfilter/nfnetlink_queue_core.c:18:0:
include/linux/skbuff.h:1822:19: note: expected ‘struct sk_buff *’ but argument is of type ‘const struct sk_buff *’
static inline int skb_orphan_frags(struct sk_buff *skb, gfp_t gfp_mask)
^
net/netfilter/nfnetlink_queue_core.c:273:3: warning: passing argument 1 of ‘skb_tx_error’ discards ‘const’ qualifier from pointer target type [enabled by default]
skb_tx_error(from);
^
In file included from net/netfilter/nfnetlink_queue_core.c:18:0:
include/linux/skbuff.h:630:13: note: expected ‘struct sk_buff *’ but argument is of type ‘const struct sk_buff *’
extern void skb_tx_error(struct sk_buff *skb);
Remove const from the 'from' parameter, the same as in the upstream
commit.
As far as I can see, this leaked into 3.10, 3.12, and 3.13 already.
Cc: Zoltan Kiss <zoltan.kiss@citrix.com> Cc: David S. Miller <davem@davemloft.net> Cc: Ben Hutchings <ben@decadent.org.uk> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Kamal Mostafa <kamal.mostafa@canonical.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
TASK_SIZE is depends on the systems architecture (32 or 64 bits) and it
should not be used for defining offset boundary for mmaping buffers for
CAPTURE and OUTPUT queues. This patch fixes support for MMAP calls on
the CAPTURE queue on 64bit architectures (like ARM64).
This fixes a oops due to a double list add when adding a reject PDU for
iscsit_allocate_iovecs allocation failures. The cmd has already been
added to the conn_cmd_list in iscsit_setup_scsi_cmd, so this has us call
iscsit_reject_cmd.
Note that for ERL0 the reject PDU is not actually sent, so this patch
is not completely tested. Just verified we do not oops. The problem is the
add reject functions return -1 which is returned all the way up to
iscsi_target_rx_thread which for ERL0 will drop the connection.
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
"ocfs2 syncs the wrong range" had been broken; prior to it the
code was doing the wrong thing in case of O_APPEND, all right,
but _after_ it we were syncing the wrong range in 100% cases.
*ppos, aka iocb->ki_pos is incremented prior to that point,
so we are always doing sync on the area _after_ the one we'd
written to.
Spotted by Joseph Qi <joseph.qi@huawei.com> back in January;
unfortunately, I'd missed his mail back then ;-/
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Kernel panic was happening as iscsi_host_remove() was called on
a host which was not yet added.
Signed-off-by: John Soni Jose <sony.john-n@emulex.com> Reviewed-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <JBottomley@Odin.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Under intermittent network outages, find_writable_file() is susceptible
to the following race condition, which results in a user-after-free in
the cifs_writepages code-path:
At this point we loop back through with an invalid inv_file pointer
and a refind value of 1. On second pass, inv_file is not overwritten on
openFileList traversal, and is subsequently dereferenced.
Signed-off-by: David Disseldorp <ddiss@suse.de> Reviewed-by: Jeff Layton <jlayton@samba.org> Signed-off-by: Steve French <smfrench@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When a device with an isochronous endpoint is plugged into the Intel
xHCI host controller, and the driver submits multiple frames per URB,
the xHCI driver will set the Block Event Interrupt (BEI) flag on all
but the last TD for the URB. This causes the host controller to place
an event on the event ring, but not send an interrupt. When the last
TD for the URB completes, BEI is cleared, and we get an interrupt for
the whole URB.
However, under Intel xHCI host controllers, if the event ring is full
of events from transfers with BEI set, an "Event Ring is Full" event
will be posted to the last entry of the event ring, but no interrupt
is generated. Host will cease all transfer and command executions and
wait until software completes handling the pending events in the event
ring. That means xHC stops, but event of "event ring is full" is not
notified. As the result, the xHC looks like dead to user.
This patch is to apply XHCI_AVOID_BEI quirk to Intel xHC devices. And
it should be backported to kernels as old as 3.0, that contains the
commit 69e848c2090a ("Intel xhci: Support EHCI/xHCI port switching.").
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Tested-by: Alistair Grant <akgrant0710@gmail.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix a bug that leads to showing the name and description of C-state C0
as "<null>" in sysfs after the ACPI C-states changed (e.g. after AC->DC
or DC->AC
transition).
The function poll_idle_init() in drivers/cpuidle/driver.c initializes the
state 0 during cpuidle_register_driver(), so we better do not overwrite it
again with '\0' during acpi_processor_cst_has_changed().
Signed-off-by: Thomas Schlichter <thomas.schlichter@web.de> Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In omap_dma_start_desc the vdesc->node is removed from the virt-dma
framework managed lists (to be precise from the desc_issued list).
If a terminate_all comes before the transfer finishes the omap_desc will
not be freed up because it is not in any of the lists and we stopped the
DMA channel so the transfer will not going to complete.
There is no special sequence for leaking memory when using cyclic (audio)
transfer: with every start and stop of a cyclic transfer the driver leaks
struct omap_desc worth of memory.
Free up the allocated memory directly in omap_dma_terminate_all() since the
framework will not going to do that for us.
This patch uses iio_trigger_get to increment the reference
count of trigger device, to avoid incorrect assignment.
Can result in a null pointer dereference during removal if the
trigger has been changed before removal.
This patch refers to a similar situation encountered through the
following discussion:
http://www.spinics.net/lists/linux-iio/msg13669.html
SCSI transport drivers and SCSI LLDs block a SCSI device if the
transport layer is not operational. This means that in this state
no requests should be processed, even if the REQ_PREEMPT flag has
been set. This patch avoids that a rescan shortly after a cable
pull sporadically triggers the following kernel oops:
This patch uses the existing CALAO Systems ftdi_8u2232c_probe in order
to avoid attaching a TTY to the JTAG port as this board is based on the
CALAO Systems reference design and needs the same fix up.
Signed-off-by: Doug Goldstein <cardoe@cardoe.com>
[johan: clean up probe logic ] Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use readb() and memcpy_fromio() accessors instead.
Reviewed-by: Christian König <christian.koenig@amd.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2f800fbd777b ("writeback: fix dirtied pages accounting on redirty")
introduced account_page_redirty() which reverts stat updates for a
redirtied page, making BDI_DIRTIED no longer monotonically increasing.
bdi_update_write_bandwidth() uses the delta in BDI_DIRTIED as the
basis for bandwidth calculation. While unlikely, since the above
patch, the newer value may be lower than the recorded past value and
underflow the bandwidth calculation leading to a wild result.
Fix it by subtracing min of the old and new values when calculating
delta. AFAIK, there hasn't been any report of it happening but the
resulting erratic behavior would be non-critical and temporary, so
it's possible that the issue is happening without being reported. The
risk of the fix is very low, so tagged for -stable.
global_update_bandwidth() uses static variable update_time as the
timestamp for the last update but forgets to initialize it to
INITIALIZE_JIFFIES.
This means that global_dirty_limit will be 5 mins into the future on
32bit and some large amount jiffies into the past on 64bit. This
isn't critical as the only effect is that global_dirty_limit won't be
updated for the first 5 mins after booting on 32bit machines,
especially given the auxiliary nature of global_dirty_limit's role -
protecting against global dirty threshold's sudden dips; however, it
does lead to unintended suboptimal behavior. Fix it.
The cause is the "memset(pgdat, 0, sizeof(*pgdat))" at the end of
try_offline_node, which will reset all the content of pgdat to 0, as the
pgdat is accessed lock-free, so that the users still using the pgdat
will panic, such as the vmstat_update routine.
process A: offline node XX:
vmstat_updat()
refresh_cpu_vm_stats()
for_each_populated_zone()
find online node XX
cond_resched()
offline cpu and memory, then try_offline_node()
node_set_offline(nid), and memset(pgdat, 0, sizeof(*pgdat))
zone = next_zone(zone)
pg_data_t *pgdat = zone->zone_pgdat; // here pgdat is NULL now
next_online_pgdat(pgdat)
next_online_node(pgdat->node_id); // NULL pointer access
So the solution here is postponing the reset of obsolete pgdat from
try_offline_node() to hotadd_new_pgdat(), and just resetting
pgdat->nr_zones and pgdat->classzone_idx to be 0 rather than the memset
0 to avoid breaking pointer information in pgdat.
The assumption before this patch was that we don't need to
run again the INIT firmware after the system booted. The
INIT firmware runs calibrations which impact the physical
layer's behavior.
Users reported that it may be helpful to run these
calibrations again every time the interface is brought up.
The penatly is minimal, since the calibrations run fast.
This fixes:
https://bugzilla.kernel.org/show_bug.cgi?id=94341
Properly verify that the resulting page aligned end address is larger
than both the start address and the length of the memory area requested.
Both the start and length arguments for ib_umem_get are controlled by
the user. A misbehaving user can provide values which will cause an
integer overflow when calculating the page aligned end address.
This overflow can cause also miscalculation of the number of pages
mapped, and additional logic issues.
Addresses: CVE-2014-8159 Signed-off-by: Shachar Raindel <raindel@mellanox.com> Signed-off-by: Jack Morgenstein <jackm@mellanox.com> Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com> Signed-off-by: Roland Dreier <roland@purestorage.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Ben Hutchings [Wed, 15 Apr 2015 18:00:32 +0000 (19:00 +0100)]
tcp: Fix crash in TCP Fast Open
Commit 355a901e6cf1 ("tcp: make connect() mem charging friendly")
changed tcp_send_syn_data() to perform an open-coded copy of the 'syn'
skb rather than using skb_copy_expand().
The open-coded copy does not cover the skb_shared_info::gso_segs
field, so in the new skb it is left set to 0. When this commit was
backported into stable branches between 3.10.y and 3.16.7-ckty
inclusive, it triggered the BUG() in tcp_transmit_skb().
Since Linux 3.18 the GSO segment count is kept in the
tcp_skb_cb::tcp_gso_segs field and tcp_send_syn_data() does copy the
tcp_skb_cb structure to the new skb, so mainline and newer stable
branches are not affected.
Set skb_shared_info::gso_segs to the correct value of 1.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Return a negative error value like the rest of the entries in this function.
Signed-off-by: Joe Perches <joe@perches.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
[PM: tweaked subject line] Signed-off-by: Paul Moore <pmoore@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Some BIOS version of Fujitsu Lifebook T731 seems to set up the
headphone pin (0x21) without the assoc number 0x0f while it's set only
to the output on the docking port (0x1a). With the recent commit
[03ad6a8c93b6: ALSA: hda - Fix "PCM" name being used on one DAC when
there are two DACs], this resulted in the weird mixer element
mapping where the headphone on the laptop is assigned as a shared
volume with the speaker and the docking port is assigned as an
individual headphone.
This patch improves the situation by correcting the headphone pin
config to the more appropriate value.
Adds an entry for Creative USB X-Fi to the rc_config array in
mixer_quirks.c to allow use of volume knob on the device.
Adds support for newer X-Fi Pro card, known as "Model No. SB1095"
with USB ID "041e:3237"
We have a HP machine which use the codec node 0x17 connecting the
internal speaker, and from the node capability, we saw the EAPD,
if we don't set the EAPD on for this node, the internal speaker
can't output any sound.
On a MIPS Malta board, tons of fifo underflow errors have been observed
when using u-boot as bootloader instead of YAMON. The reason for that
is that YAMON used to set the pcnet device to SRAM mode but u-boot does
not. As a result, the default Tx threshold (64 bytes) is now too small to
keep the fifo relatively used and it can result to Tx fifo underflow errors.
As a result of which, it's best to setup the SRAM on supported controllers
so we can always use the NOUFLO bit.
Cc: <netdev@vger.kernel.org> Cc: <linux-kernel@vger.kernel.org> Cc: Don Fry <pcnet32@frontier.com> Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 746c9e9f92dd "of/base: Fix PowerPC address parsing hack" limited
the applicability of the workaround whereby a missing ranges is treated
as an empty ranges. This workaround was hiding a bug in the etsec2
device tree nodes, which have children with reg, but did not have
ranges.
Signed-off-by: Scott Wood <scottwood@freescale.com> Reported-by: Alexander Graf <agraf@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix B-tree corruption when a new record is inserted at position 0 in the
node in hfs_brec_insert(). In this case a hfs_brec_update_parent() is
called to update the parent index node (if exists) and it is passed
hfs_find_data with a search_key containing a newly inserted key instead
of the key to be updated. This results in an inconsistent index node.
The bug reproduces on my machine after an extents overflow record for
the catalog file (CNID=4) is inserted into the extents overflow B-tree.
Because of a low (reserved) value of CNID=4, it has to become the first
record in the first leaf node.
A change in hfs_brec_insert() makes hfs_brec_update_parent() work
correctly by preventing it from getting fd->record=-1 value from
__hfs_brec_find().
Along the way, I removed duplicate code with unification of the if
condition. The resulting code is equivalent to the original code
because node is never 0.
Also hfs_brec_update_parent() will now return an error after getting a
negative fd->record value. However, the return value of
hfs_brec_update_parent() is not checked anywhere in the file and I'm
leaving it unchanged by this patch. brec.c lacks error checking after
some other calls too, but this issue is of less importance than the one
being fixed by this patch.
Signed-off-by: Sergei Antonov <saproj@gmail.com> Cc: Joe Perches <joe@perches.com> Reviewed-by: Vyacheslav Dubeyko <slava@dubeyko.com> Acked-by: Hin-Tak Leung <htl10@users.sourceforge.net> Cc: Anton Altaparmakov <aia21@cam.ac.uk> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@infradead.org> 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>
Which is caused by an irq_work generating new irq_work and therefore
not allowing forward progress.
This happens because processing the perf irq_work triggers another
perf event (tracepoint stuff) which in turn generates an irq_work ad
infinitum.
Avoid this by raising the recursion counter in the irq_work -- which
effectively disables all software events (including tracepoints) from
actually triggering again.
Reported-by: Vince Weaver <vincent.weaver@maine.edu> Tested-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/20150219170311.GH21418@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Some APs experience problems when working with
U-APSD. Decreasing the probability of that
happening by using legacy mode for all ACs but VO
isn't enough.
Cisco 4410N originally forced us to enable VO by
default only because it treated non-VO ACs as
legacy.
However some APs (notably Netgear R7000) silently
reclassify packets to different ACs. Since u-APSD
ACs require trigger frames for frame retrieval
clients would never see some frames (e.g. ARP
responses) or would fetch them accidentally after
a long time.
It makes little sense to enable u-APSD queues by
default because it needs userspace applications to
be aware of it to actually take advantage of the
possible additional powersavings. Implicitly
depending on driver autotrigger frame support
doesn't make much sense.
Signed-off-by: Michal Kazior <michal.kazior@tieto.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
As HT/VHT depend heavily on QoS/WMM, it's not a good idea to
let userspace add clients that have HT/VHT but not QoS/WMM.
Since it does so in certain cases we've observed (client is
using HT IEs but not QoS/WMM) just ignore the HT/VHT info at
this point and don't pass it down to the drivers which might
unconditionally use it.
Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch fixes the incorrect use of __transport_register_session()
in tcm_qla2xxx_check_initiator_node_acl() code, that does not perform
explicit se_tpg->session_lock when accessing se_tpg->tpg_sess_list
to add new se_sess nodes.
Given that tcm_qla2xxx_check_initiator_node_acl() is not called with
qla_hw->hardware_lock held for all accesses of ->tpg_sess_list, the
code should be using transport_register_session() instead.
This patch adds a missing set of conditional check braces in
ft_invl_hw_context() originally introduced by commit dcd998ccd
when handling DDP failures in ft_recv_write_data() code.
The correct values referred by a boolean control are
value.integer.value[], not value.enumerated.item[].
The former is long while the latter is int, so it's even incompatible
on 64bit architectures.
Signed-off-by: Takashi Iwai <tiwai@suse.de> Acked-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com> Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The correct values referred by a boolean control are
value.integer.value[], not value.enumerated.item[].
The former is long while the latter is int, so it's even incompatible
on 64bit architectures.
Signed-off-by: Takashi Iwai <tiwai@suse.de> Acked-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The correct values referred by a boolean control are
value.integer.value[], not value.enumerated.item[].
The former is long while the latter is int, so it's even incompatible
on 64bit architectures.
Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The correct values referred by a boolean control are
value.integer.value[], not value.enumerated.item[].
The former is long while the latter is int, so it's even incompatible
on 64bit architectures.
Signed-off-by: Takashi Iwai <tiwai@suse.de> Acked-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com> Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The correct values referred by a boolean control are
value.integer.value[], not value.enumerated.item[].
The former is long while the latter is int, so it's even incompatible
on 64bit architectures.
Signed-off-by: Takashi Iwai <tiwai@suse.de> Acked-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com> Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The correct values referred by a boolean control are
value.integer.value[], not value.enumerated.item[].
The former is long while the latter is int, so it's even incompatible
on 64bit architectures.
Signed-off-by: Takashi Iwai <tiwai@suse.de> Acked-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com> Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The correct values referred by a boolean control are
value.integer.value[], not value.enumerated.item[].
The former is long while the latter is int, so it's even incompatible
on 64bit architectures.
Signed-off-by: Takashi Iwai <tiwai@suse.de> Acked-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com> Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The correct values referred by a boolean control are
value.integer.value[], not value.enumerated.item[].
The former is long while the latter is int, so it's even incompatible
on 64bit architectures.
Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The correct values referred by a boolean control are
value.integer.value[], not value.enumerated.item[].
The former is long while the latter is int, so it's even incompatible
on 64bit architectures.
Signed-off-by: Takashi Iwai <tiwai@suse.de> Acked-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com> Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The correct values referred by a boolean control are
value.integer.value[], not value.enumerated.item[].
The former is long while the latter is int, so it's even incompatible
on 64bit architectures.
Signed-off-by: Takashi Iwai <tiwai@suse.de> Acked-by: Paul Handrigan <Paul.Handrigan@cirrus.com> Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The SGTL5000_CHIP_ANA_POWER register is cached. Update the cached
value instead of writing it directly.
Patch inspired by Russell King's more colorful remarks in this
patch:
https://github.com/SolidRun/linux-imx6-3.14/commit/dd4bf6a
Signed-off-by: Eric Nelson <eric.nelson@boundarydevices.com> Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch changes core_scsi3_pro_release() logic to allow an
existing AllRegistrants type reservation to be re-reserved by
any registered I_T nexus.
This addresses a issue where AllRegistrants type RESERVE was
receiving RESERVATION_CONFLICT status if dev_pr_res_holder did
not match the same I_T nexus, instead of just returning GOOD
status following spc4r34 Section 5.9.9:
"If the device server receives a PERSISTENT RESERVE OUT command
with RESERVE service action where the TYPE field and the SCOPE
field contain the same values as the existing type and scope
from a persistent reservation holder, it shall not make any
change to the existing persistent reservation and shall complete
the command with GOOD status."
Reported-by: Ilias Tsitsimpis <i.tsitsimpis@gmail.com> Cc: Ilias Tsitsimpis <i.tsitsimpis@gmail.com> Cc: Lee Duncan <lduncan@suse.com> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch fixes the usage of R_HOLDER bit for an All Registrants
reservation in READ_FULL_STATUS, where only the registration who
issued RESERVE was being reported as having an active reservation.
It changes core_scsi3_pri_read_full_status() to check ahead of the
list walk of active registrations to see if All Registrants is active,
and if so set R_HOLDER bit and scope/type fields for all active
registrations.
Reported-by: Ilias Tsitsimpis <i.tsitsimpis@gmail.com> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch fixes a NULL pointer dereference OOPs with pSCSI backends
within target_core_stat.c code. The bug is caused by a configfs attr
read if no pscsi_dev_virt->pdv_sd has been configured.
Reported-by: Olaf Hering <olaf@aepfle.de> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch fixes a iser specific logout bug where early complete()
of conn->conn_logout_comp in iscsit_close_connection() was causing
isert_wait4logout() to complete too soon, triggering a use after
free NULL pointer dereference of iscsi_conn memory.
The complete() was originally added for traditional iscsi-target
when a ISCSI_LOGOUT_OP failed in iscsi_target_rx_opcode(), but given
iser-target does not wait in logout failure, this special case needs
to be avoided.
at91rm9200 standby and suspend to ram has been broken since 00482a4078f4. It is wrongly using AT91_BASE_SYS which is a physical address
and actually doesn't correspond to any register on at91rm9200.
Use the correct at91_ramc_base[0] instead.
Fixes: 00482a4078f4 (ARM: at91: implement the standby function for pm/cpuidle) Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f5a41847acc5 ("ipvs: move ip_route_me_harder for ICMP")
from 2.6.37 introduced ip_route_me_harder() call for responses to
local clients, so that we can provide valid rt_src after SNAT.
It was used by TCP to provide valid daddr for ip_send_reply().
After commit 0a5ebb8000c5 ("ipv4: Pass explicit daddr arg to
ip_send_reply()." from 3.0 this rerouting is not needed anymore
and should be avoided, especially in LOCAL_IN.
Fixes 3.12.33 crash in xfrm reported by Florian Wiessner:
"3.12.33 - BUG xfrm_selector_match+0x25/0x2f6"
ip_vs_conn_fill_param_sync() gets in param.pe a module
reference for persistence engine from __ip_vs_pe_getbyname()
but forgets to put it. Problem occurs in backup for
sync protocol v1 (2.6.39).
Also, pe_data usually comes in sync messages for
connection templates and ip_vs_conn_new() copies
the pointer only in this case. Make sure pe_data
is not leaked if it comes unexpectedly for normal
connections. Leak can happen only if bogus messages
are sent to backup server.
Anton has a busy ppc64le KVM box where guests sometimes hit the infamous
"kernel BUG at kernel/smpboot.c:134!" issue during boot:
BUG_ON(td->cpu != smp_processor_id());
Basically a per CPU hotplug thread scheduled on the wrong CPU. The oops
output confirms it:
CPU: 0
Comm: watchdog/130
The problem is that we aren't ensuring the CPU active bit is set for the
secondary before allowing the master to continue on. The master unparks
the secondary CPU's kthreads and the scheduler looks for a CPU to run
on. It calls select_task_rq() and realises the suggested CPU is not in
the cpus_allowed mask. It then ends up in select_fallback_rq(), and
since the active bit isnt't set we choose some other CPU to run on.
This seems to have been introduced by 6acbfb96976f "sched: Fix hotplug
vs. set_cpus_allowed_ptr()", which changed from setting active before
online to setting active after online. However that was in turn fixing a
bug where other code assumed an active CPU was also online, so we can't
just revert that fix.
The simplest fix is just to spin waiting for both active & online to be
set. We already have a barrier prior to set_cpu_online() (which also
sets active), to ensure all other setup is completed before online &
active are set.
Fixes: 6acbfb96976f ("sched: Fix hotplug vs. set_cpus_allowed_ptr()") Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Because prior GCC versions always emitted NOPs on ALIGN directives, but
gcc5 started omitting them.
.LSTARTFDEDLSI1 says:
/* HACK: The dwarf2 unwind routines will subtract 1 from the
return address to get an address in the middle of the
presumed call instruction. Since we didn't get here via
a call, we need to include the nop before the real start
to make up for it. */
.long .LSTART_sigreturn-1-. /* PC-relative start address */
But commit 69d0627a7f6e ("x86 vDSO: reorder vdso32 code") from 2.6.25
replaced .org __kernel_vsyscall+32,0x90 by ALIGN right before
__kernel_sigreturn.
Of course, ALIGN need not generate any NOP in there. Esp. gcc5 collapses
vclock_gettime.o and int80.o together with no generated NOPs as "ALIGN".
So fix this by adding to that point at least a single NOP and make the
function ALIGN possibly with more NOPs then.
Kudos for reporting and diagnosing should go to Richard.
Reported-by: Richard Biener <rguenther@suse.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1425543211-12542-1-git-send-email-jslaby@suse.cz Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drop_fpu() does clear_used_math() and usually this is correct
because tsk == current.
However switch_fpu_finish()->restore_fpu_checking() is called before
__switch_to() updates the "current_task" variable. If it fails,
we will wrongly clear the PF_USED_MATH flag of the previous task.
So use clear_stopped_child_used_math() instead.
Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Pekka Riikonen <priikone@iki.fi> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Suresh Siddha <sbsiddha@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20150309171041.GB11388@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
math_state_restore() assumes it is called with irqs disabled,
but this is not true if the caller is __restore_xstate_sig().
This means that if ia32_fxstate == T and __copy_from_user()
fails, __restore_xstate_sig() returns with irqs disabled too.
This triggers:
BUG: sleeping function called from invalid context at kernel/locking/rwsem.c:41
dump_stack
___might_sleep
? _raw_spin_unlock_irqrestore
__might_sleep
down_read
? _raw_spin_unlock_irqrestore
print_vma_addr
signal_fault
sys32_rt_sigreturn
Change __restore_xstate_sig() to call set_used_math()
unconditionally. This avoids enabling and disabling interrupts
in math_state_restore(). If copy_from_user() fails, we can
simply do fpu_finit() by hand.
[ Note: this is only the first step. math_state_restore() should
not check used_math(), it should set this flag. While
init_fpu() should simply die. ]
Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Pekka Riikonen <priikone@iki.fi> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Rik van Riel <riel@redhat.com> Cc: Suresh Siddha <sbsiddha@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20150307153844.GB25954@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The kernel crypto API logic requires the caller to provide the
length of (ciphertext || authentication tag) as cryptlen for the
AEAD decryption operation. Thus, the cipher implementation must
calculate the size of the plaintext output itself and cannot simply use
cryptlen.
The RFC4106 GCM decryption operation tries to overwrite cryptlen memory
in req->dst. As the destination buffer for decryption only needs to hold
the plaintext memory but cryptlen references the input buffer holding
(ciphertext || authentication tag), the assumption of the destination
buffer length in RFC4106 GCM operation leads to a too large size. This
patch simply uses the already calculated plaintext size.
In addition, this patch fixes the offset calculation of the AAD buffer
pointer: as mentioned before, cryptlen already includes the size of the
tag. Thus, the tag does not need to be added. With the addition, the AAD
will be written beyond the already allocated buffer.
Note, this fixes a kernel crash that can be triggered from user space
via AF_ALG(aead) -- simply use the libkcapi test application
from [1] and update it to use rfc4106-gcm-aes.
Using [1], the changes were tested using CAVS vectors to demonstrate
that the crypto operation still delivers the right results.
[1] http://www.chronox.de/libkcapi.html
CC: Tadeusz Struk <tadeusz.struk@intel.com> Signed-off-by: Stephan Mueller <smueller@chronox.de> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
It's directly caused by 89d3cf6 [SCSI] libsas: add mutex for SMP task
execution, but shows a deeper cause: expander functions expect to be able to
cast to and treat domain devices as expanders. The correct fix is to only do
expander discover when we know we've got an expander device to avoid wrongly
casting a non-expander device.
Otherwise the guest can abuse that control to cause e.g. PCIe
Unsupported Request responses by disabling memory and/or I/O decoding
and subsequently causing (CPU side) accesses to the respective address
ranges, which (depending on system configuration) may be fatal to the
host.
Note that to alter any of the bits collected together as
PCI_COMMAND_GUEST permissive mode is now required to be enabled
globally or on the specific device.
This is CVE-2015-2150 / XSA-120.
Signed-off-by: Jan Beulich <jbeulich@suse.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
According to a report from Yuxuan Shui, nilfs2 in kernel 3.19 got stuck
during recovery at mount time. The code path that caused the deadlock was
as follows:
nilfs_fill_super()
load_nilfs()
nilfs_salvage_orphan_logs()
* Do roll-forwarding, attach segment constructor for recovery,
and kick it.
nilfs_segctor_thread()
nilfs_segctor_thread_construct()
* A lock is held with nilfs_transaction_lock()
nilfs_segctor_do_construct()
nilfs_segctor_drop_written_files()
iput()
iput_final()
write_inode_now()
writeback_single_inode()
__writeback_single_inode()
do_writepages()
nilfs_writepage()
nilfs_construct_dsync_segment()
nilfs_transaction_lock() --> deadlock
This can happen if commit 7ef3ff2fea8b ("nilfs2: fix deadlock of segment
constructor over I_SYNC flag") is applied and roll-forward recovery was
performed at mount time. The roll-forward recovery can happen if datasync
write is done and the file system crashes immediately after that. For
instance, we can reproduce the issue with the following steps:
< nilfs2 is mounted on /nilfs (device: /dev/sdb1) >
# dd if=/dev/zero of=/nilfs/test bs=4k count=1 && sync
# dd if=/dev/zero of=/nilfs/test conv=notrunc oflag=dsync bs=4k
count=1 && reboot -nfh
< the system will immediately reboot >
# mount -t nilfs2 /dev/sdb1 /nilfs
The deadlock occurs because iput() can run segment constructor through
writeback_single_inode() if MS_ACTIVE flag is not set on sb->s_flags. The
above commit changed segment constructor so that it calls iput()
asynchronously for inodes with i_nlink == 0, but that change was
imperfect.
This fixes the another deadlock by deferring iput() in segment constructor
even for the case that mount is not finished, that is, for the case that
MS_ACTIVE flag is not set.
Normally _regulator_do_enable() isn't called on an already-enabled
rdev. That's because the main caller, _regulator_enable() always
calls _regulator_is_enabled() and only calls _regulator_do_enable() if
the rdev was not already enabled.
However, there is one caller of _regulator_do_enable() that doesn't
check: regulator_suspend_finish(). While we might want to make
regulator_suspend_finish() behave more like _regulator_enable(), it's
probably also a good idea to make _regulator_do_enable() robust if it
is called on an already enabled rdev.
At the moment, _regulator_do_enable() is _not_ robust for already
enabled rdevs if we're using an ena_pin. Each time
_regulator_do_enable() is called for an rdev using an ena_pin the
reference count of the ena_pin is incremented even if the rdev was
already enabled. This is not as intended because the ena_pin is for
something else: for keeping track of how many active rdevs there are
sharing the same ena_pin.
Here's how the reference counting works here:
* Each time _regulator_enable() is called we increment
rdev->use_count, so _regulator_enable() calls need to be balanced
with _regulator_disable() calls.
* There is no explicit reference counting in _regulator_do_enable()
which is normally just a warapper around rdev->desc->ops->enable()
with code for supporting delays. It's not expected that the
"ops->enable()" call do reference counting.
* Since regulator_ena_gpio_ctrl() does have reference counting
(handling the sharing of the pin amongst multiple rdevs), we
shouldn't call it if the current rdev is already enabled.
Note that as part of this we cleanup (remove) the initting of
ena_gpio_state in regulator_register(). In _regulator_do_enable(),
_regulator_do_disable() and _regulator_is_enabled() is is clear that
ena_gpio_state should be the state of whether this particular rdev has
requested the GPIO be enabled. regulator_register() was initting it
as the actual state of the pin.
Fixes: 967cfb18c0e3 ("regulator: core: manage enable GPIO list") Signed-off-by: Doug Anderson <dianders@chromium.org> Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The _regulator_do_enable() call ought to be a no-op when called on an
already-enabled regulator. However, as an optimization
_regulator_enable() doesn't call _regulator_do_enable() on an already
enabled regulator. That means we never test the case of calling
_regulator_do_enable() during normal usage and there may be hidden
bugs or warnings. We have seen warnings issued by the tps65090 driver
and bugs when using the GPIO enable pin.
Let's match the same optimization that _regulator_enable() in
regulator_suspend_finish(). That may speed up suspend/resume and also
avoids exposing hidden bugs.
[Use much clearer commit message from Doug Anderson]
Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk> Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The commit [ef403edb7558: ALSA: hda - Don't access stereo amps for
mono channel widgets] fixed the handling of mono widgets in general,
but it still misses an exceptional case: namely, a mono mixer widget
taking a single stereo input. In this case, it has stereo volumes
although it's a mono widget, and thus we have to take care of both
left and right input channels, as stated in HD-audio spec ("7.1.3
Widget Interconnection Rules").
This patch covers this missing piece by adding proper checks of stereo
amps in both the generic parser and the proc output codes.
MacBook Air 5,2 has the same problem as MacBook Pro 8,1 where the
built-in mic records only the right channel. Apply the same
workaround as MBP8,1 to spread the mono channel via a Cirrus codec
vendor-specific COEF setup.
CS420x codecs seem to deal only the single amps of ADC nodes even
though the nodes receive multiple inputs. This leads to the
inconsistent amp value after S3/S4 resume, for example.
The fix is just to set codec->single_adc_amp flag. Then the driver
handles these ADC amps as if single connections.
The current HDA generic parser initializes / modifies the amp values
always in stereo, but this seems causing the problem on ALC3229 codec
that has a few mono channel widgets: namely, these mono widgets react
to actions for both channels equally.
In the driver code, we do care the mono channel and create a control
only for the left channel (as defined in HD-audio spec) for such a
node. When the control is updated, only the left channel value is
changed. However, in the resume, the right channel value is also
restored from the initial value we took as stereo, and this overwrites
the left channel value. This ends up being the silent output as the
right channel has been never touched and remains muted.
This patch covers the places where unconditional stereo amp accesses
are done and converts to the conditional accesses.
Compaq Presario CQ60 laptop with CX20561 gives a wrong pin for the
built-in mic NID 0x17 instead of NID 0x1d, and it results in the
non-working mic. This patch just remaps the pin correctly via fixup.
There was no check about the id string of user control elements, so we
accepted even a control element with an empty string, which is
obviously bogus. This patch adds more sanity checks of id strings.
Commit fd316941c ("spi/pl022: disable port when unused") introduced a race,
which leads to possible driver lock up (easily reproducible on SMP).
The problem happens in giveback() function where the completion of the transfer
is signalled to SPI subsystem and then the HW SPI controller is disabled. Another
transfer might be setup in between, which brings driver in locked-up state.
Lockup! SPI controller is disabled and the data will never be received. Whole
SPI subsystem is waiting for transfer ACK and blocked.
So, only signal transfer completion after disabling the controller.
Fixes: fd316941c (spi/pl022: disable port when unused) Signed-off-by: Alexander Sverdlin <alexander.sverdlin@nokia.com> Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Problem: When IMA and VTPM are both enabled in kernel config,
kernel hangs during bootup on LE OS.
Why?: IMA calls tpm_pcr_read() which results in tpm_ibmvtpm_send
and tpm_ibmtpm_recv getting called. A trace showed that
tpm_ibmtpm_recv was hanging.
Resolution: tpm_ibmtpm_recv was hanging because tpm_ibmvtpm_send
was sending CRQ message that probably did not make much sense
to phype because of Endianness. The fix below sends correctly
converted CRQ for LE. This was not caught before because it
seems IMA is not enabled by default in kernel config and
IMA exercises this particular code path in vtpm.
Tested with IMA and VTPM enabled in kernel config and VTPM
enabled on both a BE OS and a LE OS ppc64 lpar. This exercised
CRQ and TPM command code paths in vtpm.
Patch is against Peter's tpmdd tree on github which included
Vicky's previous vtpm le patches.
Signed-off-by: Joy Latten <jmlatten@linux.vnet.ibm.com> Reviewed-by: Ashley Lai <ashley@ahsleylai.com> Signed-off-by: Peter Huewe <peterhuewe@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cancel[_delayed]_work_sync() are implemented using
__cancel_work_timer() which grabs the PENDING bit using
try_to_grab_pending() and then flushes the work item with PENDING set
to prevent the on-going execution of the work item from requeueing
itself.
try_to_grab_pending() can always grab PENDING bit without blocking
except when someone else is doing the above flushing during
cancelation. In that case, try_to_grab_pending() returns -ENOENT. In
this case, __cancel_work_timer() currently invokes flush_work(). The
assumption is that the completion of the work item is what the other
canceling task would be waiting for too and thus waiting for the same
condition and retrying should allow forward progress without excessive
busy looping
Unfortunately, this doesn't work if preemption is disabled or the
latter task has real time priority. Let's say task A just got woken
up from flush_work() by the completion of the target work item. If,
before task A starts executing, task B gets scheduled and invokes
__cancel_work_timer() on the same work item, its try_to_grab_pending()
will return -ENOENT as the work item is still being canceled by task A
and flush_work() will also immediately return false as the work item
is no longer executing. This puts task B in a busy loop possibly
preventing task A from executing and clearing the canceling state on
the work item leading to a hang.
task A task B worker
executing work
__cancel_work_timer()
try_to_grab_pending()
set work CANCELING
flush_work()
block for work completion
completion, wakes up A
__cancel_work_timer()
while (forever) {
try_to_grab_pending()
-ENOENT as work is being canceled
flush_work()
false as work is no longer executing
}
This patch removes the possible hang by updating __cancel_work_timer()
to explicitly wait for clearing of CANCELING rather than invoking
flush_work() after try_to_grab_pending() fails with -ENOENT.
Link: http://lkml.kernel.org/g/20150206171156.GA8942@axis.com
v3: bit_waitqueue() can't be used for work items defined in vmalloc
area. Switched to custom wake function which matches the target
work item and exclusive wait and wakeup.
v2: v1 used wake_up() on bit_waitqueue() which leads to NULL deref if
the target bit waitqueue has wait_bit_queue's on it. Use
DEFINE_WAIT_BIT() and __wake_up_bit() instead. Reported by Tomeu
Vizoso.
when multiport is off, we don't initialize config work,
but we then cancel uninitialized control_work on freeze.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-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>
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>
Reviewed-by: Christian König <christian.koenig@amd.com> Signed-off-by: Tommi Rantala <tt.rantala@gmail.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
projects / linux-stable / log