This patch adds an infrastructure to keep track of the CPU feature
registers on the system. For each register, the infrastructure keeps
track of the system wide safe value of the feature bits. Also, tracks
the which fields of a register should be matched strictly across all
the CPUs on the system for the SANITY check infrastructure.
The feature bits are classified into following 3 types depending on
the implication of the possible values. This information is used to
decide the safe value for a feature.
LOWER_SAFE - The smaller value is safer
HIGHER_SAFE - The bigger value is safer
EXACT - We can't decide between the two, so a predefined safe_value is used.
This infrastructure will be later used to make better decisions for:
- Kernel features (e.g, KVM, Debug)
- SANITY Check
- CPU capability
- ELF HWCAP
- Exposing CPU Feature register to userspace.
Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com>
Tested-by: Dave Martin <Dave.Martin@arm.com>
[catalin.marinas@arm.com: whitespace fix]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Introduce a helper to extract cpuid feature for any given
width.
Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com>
Tested-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This patch moves the /proc/cpuinfo handling code:
arch/arm64/kernel/{setup.c to cpuinfo.c}
No functional changes
Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com>
Tested-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Move the mixed endian support detection code to cpufeature.c
from cpuinfo.c. This also moves the update_cpu_features()
used by mixed endian detection code, which will get more
functionality.
Also moves the ID register field shifts to asm/sysreg.h,
where all the useful definitions will end up in later patches.
Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com>
Tested-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This patch moves the CPU feature detection code from
arch/arm64/kernel/{setup.c to cpufeature.c}
The plan is to consolidate all the CPU feature handling
in cpufeature.c.
Apart from changing pr_fmt from "alternatives" to "cpu features",
there are no functional changes.
Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com>
Tested-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
At the moment the boot CPU stores the cpuinfo long before the
PERCPU areas are initialised by the kernel. This could be problematic
as the non-boot CPU data structures might get copied with the data
from the boot CPU, giving us no chance to detect if a particular CPU
updated its cpuinfo. This patch delays the boot cpu store to
smp_prepare_boot_cpu().
Also kills the setup_processor() which no longer does meaningful
work.
Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com>
Tested-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Delay the ELF HWCAP initialisation until all the (enabled) CPUs are
up, i.e, smp_cpus_done(). This is in preparation for detecting the
common features across the CPUS and creating a consistent ELF HWCAP
for the system.
Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com>
Tested-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
At early boot, we print the CPU version/revision. On a heterogeneous
system, we could have different types of CPUs. Print the CPU info for
all active cpus. Also, the secondary CPUs prints the message only when
they turn online.
Also, remove the redundant 'revision' information which doesn't
make any sense without the 'variant' field.
Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com>
Tested-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
The supplied script takes a signed module file and extracts the tailmost
signature (there could theoretically be more than one) and dumps all or
part of it or the unsigned file to stdout.
Call as:
scripts/extract-module-sig.pl -[0adnks] module-file >out
where the initial flag indicates which bit of the signed file you want dumping
to stdout:
(*) "-0". Dumps the unsigned data with the signature stripped.
(*) "-a". Dumps all of the signature data, including the magic number.
(*) "-d". Dumps the signature information block as a sequence of decimal
numbers in text form with spaces between (crypto algorithm type,
hash type, identifier type, signer's name length, key identifier
length and signature length).
(*) "-n". Dumps the signer's name contents.
(*) "-k". Dumps the key identifier contents.
(*) "-s". Dumps the cryptographic signature contents.
In the case that the signature is a PKCS#7 (or CMS) message, -n and -k will
print a warning to stderr and dump nothing to stdout, but will otherwise
complete okay; the entire PKCS#7/CMS message will be dumped by "-s"; and "-d"
will show "0 0 2 0 0 <pkcs#7-msg-len>".
Signed-off-by: David Howells <dhowells@redhat.com>
The supplied script takes a vmlinux file - and if necessary a System.map
file - locates the system certificates list and extracts it to the named
file.
Call as:
./scripts/extract-sys-certs vmlinux certs
if vmlinux contains symbols and:
./scripts/extract-sys-certs -s System.map vmlinux certs
if it does not.
It prints something like the following to stdout:
Have 27 sections
No symbols in vmlinux, trying System.map
Have 80088 symbols
Have 1346 bytes of certs at VMA 0xffffffff8201c540
Certificate list in section .init.data
Certificate list at file offset 0x141c540
If vmlinux contains symbols then that is used rather than System.map - even
if one is given.
Signed-off-by: David Howells <dhowells@redhat.com>
key->description and key->index_key.description are same because
they are unioned. But, for readability, using same name for
duplication and validation seems better.
Signed-off-by: Insu Yun <wuninsu@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Currently we see this in "git status" if we build in the source dir:
Untracked files:
(use "git add <file>..." to include in what will be committed)
certs/x509_certificate_list
It looks like it used to live in kernel/ so we squash that .gitignore
entry at the same time. I didn't bother to dig through git history to
see when it moved, since it is just a minor annoyance at most.
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: keyrings@linux-nfs.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David Howells <dhowells@redhat.com>
There is no need to make a flag to tell that this memory is allocated by
kmalloc or vmalloc. Just use kvfree to free the memory.
Signed-off-by: Geliang Tang <geliangtang@163.com>
Signed-off-by: David Howells <dhowells@redhat.com>
a20135ffbc ("writeback: don't drain bdi_writeback_congested on bdi
destruction") added rbtree_postorder_for_each_entry_safe() which is
used to remove all entries; however, according to Cody, the iterator
isn't safe against operations which may rebalance the tree. Fix it by
switching to repeatedly removing rb_first() until empty.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Cody P Schafer <dev@codyps.com>
Fixes: a20135ffbc ("writeback: don't drain bdi_writeback_congested on bdi destruction")
Link: http://lkml.kernel.org/g/1443997973-1700-1-git-send-email-dev@codyps.com
Signed-off-by: Jens Axboe <axboe@fb.com>
Both start_branch_trace() and stop_branch_trace() are used in only one
location, and are both static. As they are small functions there is no
need to keep them separated out.
Link: http://lkml.kernel.org/r/1445000689-32596-1-git-send-email-0x7f454c46@gmail.com
Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Yuchung Cheng says:
====================
RACK loss detection
RACK (Recent ACK) loss recovery uses the notion of time instead of
packet sequence (FACK) or counts (dupthresh).
It's inspired by the FACK heuristic in tcp_mark_lost_retrans(): when a
limited transmit (new data packet) is sacked in recovery, then any
retransmission sent before that newly sacked packet was sent must have
been lost, since at least one round trip time has elapsed.
But that existing heuristic from tcp_mark_lost_retrans()
has several limitations:
1) it can't detect tail drops since it depends on limited transmit
2) it's disabled upon reordering (assumes no reordering)
3) it's only enabled in fast recovery but not timeout recovery
RACK addresses these limitations with a core idea: an unacknowledged
packet P1 is deemed lost if a packet P2 that was sent later is is
s/acked, since at least one round trip has passed.
Since RACK cares about the time sequence instead of the data sequence
of packets, it can detect tail drops when a later retransmission is
s/acked, while FACK or dupthresh can't. For reordering RACK uses a
dynamically adjusted reordering window ("reo_wnd") to reduce false
positives on ever (small) degree of reordering, similar to the delayed
Early Retransmit.
In the current patch set RACK is only a supplemental loss detection
and does not trigger fast recovery. However we are developing RACK
to replace or consolidate FACK/dupthresh, early retransmit, and
thin-dupack. These heuristics all implicitly bear the time notion.
For example, the delayed Early Retransmit is simply applying RACK
to trigger the fast recovery with small inflight.
RACK requires measuring the minimum RTT. Tracking a global min is less
robust due to traffic engineering pathing changes. Therefore it uses a
windowed filter by Kathleen Nichols. The min RTT can also be useful
for various other purposes like congestion control or stat monitoring.
This patch has been used on Google servers for well over 1 year. RACK
has also been implemented in the QUIC protocol. We are submitting an
IETF draft as well.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch implements the second half of RACK that uses the the most
recent transmit time among all delivered packets to detect losses.
tcp_rack_mark_lost() is called upon receiving a dubious ACK.
It then checks if an not-yet-sacked packet was sent at least
"reo_wnd" prior to the sent time of the most recently delivered.
If so the packet is deemed lost.
The "reo_wnd" reordering window starts with 1msec for fast loss
detection and changes to min-RTT/4 when reordering is observed.
We found 1msec accommodates well on tiny degree of reordering
(<3 pkts) on faster links. We use min-RTT instead of SRTT because
reordering is more of a path property but SRTT can be inflated by
self-inflicated congestion. The factor of 4 is borrowed from the
delayed early retransmit and seems to work reasonably well.
Since RACK is still experimental, it is now used as a supplemental
loss detection on top of existing algorithms. It is only effective
after the fast recovery starts or after the timeout occurs. The
fast recovery is still triggered by FACK and/or dupack threshold
instead of RACK.
We introduce a new sysctl net.ipv4.tcp_recovery for future
experiments of loss recoveries. For now RACK can be disabled by
setting it to 0.
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch is the first half of the RACK loss recovery.
RACK loss recovery uses the notion of time instead
of packet sequence (FACK) or counts (dupthresh). It's inspired by the
previous FACK heuristic in tcp_mark_lost_retrans(): when a limited
transmit (new data packet) is sacked, then current retransmitted
sequence below the newly sacked sequence must been lost,
since at least one round trip time has elapsed.
But it has several limitations:
1) can't detect tail drops since it depends on limited transmit
2) is disabled upon reordering (assumes no reordering)
3) only enabled in fast recovery ut not timeout recovery
RACK (Recently ACK) addresses these limitations with the notion
of time instead: a packet P1 is lost if a later packet P2 is s/acked,
as at least one round trip has passed.
Since RACK cares about the time sequence instead of the data sequence
of packets, it can detect tail drops when later retransmission is
s/acked while FACK or dupthresh can't. For reordering RACK uses a
dynamically adjusted reordering window ("reo_wnd") to reduce false
positives on ever (small) degree of reordering.
This patch implements tcp_advanced_rack() which tracks the
most recent transmission time among the packets that have been
delivered (ACKed or SACKed) in tp->rack.mstamp. This timestamp
is the key to determine which packet has been lost.
Consider an example that the sender sends six packets:
T1: P1 (lost)
T2: P2
T3: P3
T4: P4
T100: sack of P2. rack.mstamp = T2
T101: retransmit P1
T102: sack of P2,P3,P4. rack.mstamp = T4
T205: ACK of P4 since the hole is repaired. rack.mstamp = T101
We need to be careful about spurious retransmission because it may
falsely advance tp->rack.mstamp by an RTT or an RTO, causing RACK
to falsely mark all packets lost, just like a spurious timeout.
We identify spurious retransmission by the ACK's TS echo value.
If TS option is not applicable but the retransmission is acknowledged
less than min-RTT ago, it is likely to be spurious. We refrain from
using the transmission time of these spurious retransmissions.
The second half is implemented in the next patch that marks packet
lost using RACK timestamp.
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
a helper to prepare the first main RACK patch.
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
a helper to prepare the main RACK patch
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Remove the existing lost retransmit detection because RACK subsumes
it completely. This also stops the overloading the ack_seq field of
the skb control block.
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Kathleen Nichols' algorithm for tracking the minimum RTT of a
data stream over some measurement window. It uses constant space
and constant time per update. Yet it almost always delivers
the same minimum as an implementation that has to keep all
the data in the window. The measurement window is tunable via
sysctl.net.ipv4.tcp_min_rtt_wlen with a default value of 5 minutes.
The algorithm keeps track of the best, 2nd best & 3rd best min
values, maintaining an invariant that the measurement time of
the n'th best >= n-1'th best. It also makes sure that the three
values are widely separated in the time window since that bounds
the worse case error when that data is monotonically increasing
over the window.
Upon getting a new min, we can forget everything earlier because
it has no value - the new min is less than everything else in the
window by definition and it's the most recent. So we restart fresh
on every new min and overwrites the 2nd & 3rd choices. The same
property holds for the 2nd & 3rd best.
Therefore we have to maintain two invariants to maximize the
information in the samples, one on values (1st.v <= 2nd.v <=
3rd.v) and the other on times (now-win <=1st.t <= 2nd.t <= 3rd.t <=
now). These invariants determine the structure of the code
The RTT input to the windowed filter is the minimum RTT measured
from ACK or SACK, or as the last resort from TCP timestamps.
The accessor tcp_min_rtt() returns the minimum RTT seen in the
window. ~0U indicates it is not available. The minimum is 1usec
even if the true RTT is below that.
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently ca_seq_rtt_us does not use Kern's check. Fix that by
checking if any packet acked is a retransmit, for both RTT used
for RTT estimation and congestion control.
Fixes: 5b08e47ca ("tcp: prefer packet timing to TS-ECR for RTT")
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Heiko Schocher says:
====================
net, phy, smsc: add posibility to disable energy detect mode
On some boards the energy enable detect mode leads in
trouble with some switches, so make the enabling of
this mode configurable through DT.
Therefore the property "smsc,disable-energy-detect" is
introduced.
Patch 1 introduces phy-handle support for the ti,cpsw
driver. This is needed now for the smsc phy.
Patch 2 adds the disable energy mode functionality
to the smsc phy
Changes in v2:
- add comments from Florian Fainelli
- I did not change disable property name into enable
because I fear to break existing behaviour
- add smsc vendor prefix
- remove CONFIG_OF and use __maybe_unused
- introduce "phy-handle" ability into ti,cpsw
driver, so I can remove bogus:
if (!of_node && dev->parent->of_node)
of_node = dev->parent->of_node;
construct. Therefore new patch for the ti,cpsw
driver is necessary.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
On some boards the energy enable detect mode leads in
trouble with some switches, so make the enabling of
this mode configurable through DT.
Signed-off-by: Heiko Schocher <hs@denx.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
add the ability to parse "phy-handle". This
is needed for phys, which have a DT node, and
need to parse DT properties.
Signed-off-by: Heiko Schocher <hs@denx.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
If a gigabit ethernet PHY is connected to a fast ethernet MAC,
then it can detect 1000 support from the partner but not use it.
This results in a forced speed of 1000 and RX/TX failure.
Check for 1000BASE-T support and then check the advertisement
configuration before setting the MAC speed to 1000mbit.
Signed-off-by: Simon Arlott <simon@fire.lp0.eu>
Signed-off-by: David S. Miller <davem@davemloft.net>
Jeff Kirsher says:
====================
Intel Wired LAN Driver Updates 2015-10-19
This series contains updates to i40e and i40evf only.
Kiran adds a spinlock around code accessing VSI MAC filter list to
ensure that we are synchronizing access to the filter list, otherwise
we can end up with multiple accesses at the same time which can cause
the VSI MAC filter list to get in an unstable or corrupted state.
Jesse fixes overlong BIT defines, where the RSS enabling call were
mistakenly missed. Also fixes a bug where the enable function was
enabling the interrupt twice while trying to update the two interrupt
throttle rate thresholds for Rx and Tx, while refactoring the IRQ
enable function to simplify reading the flow. Addressed the high
CPU utilization of some small streaming workloads that the driver should
reduce CPU in.
Anjali fixes two X722 issues with respect to EEPROM checksum verify and
reading NVM version info. Fixed where a mask value was accidentally
replaced with a bit mask causing Flow Director sideband to be broken.
Alex Duyck fixes areas of the drivers which run from hard interrupt
context or with interrupts already disabled in netpoll, so use
napi_schedule_irqoff() instead of napi_schedule().
Mitch fixes the VF drivers to not easily give up when it is not able
to communicate with the PF driver.
Carolyn fixes a problem where our tools MAC loopback test, after driver
unbind would fail because the hardware was configured for multiqueue and
unbind operation did not clear this configuration. Also fixed a issue
where the NVMUpdate tool gets bad data from the PHY when using the PHY
NVM feature because of contention on the MDIO interface from getting
PHY capability calls from the driver during regular operations.
Catherine fixed an issue where we were checking if autoneg was allowed
to change before checking if autoneg was changing, these checks need to
be in the reverse order.
Jean Sacren fixes up an function header comment to align the kernel-docs
with the actual code.
v2: Cleaned up the use of spin_is_locked() in patch 1 based on feedback
from David Miller, since it always evaluates to zero on uni-processor
builds
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Tested-by: Adam Thomson <Adam.Thomson.Opensource@diasemi.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
Neither the rockchip i2s nor the rockchip spdif binding support child
devices so #address-cells and #size-cells properties aren't required.
Remove these from the bindings.
Signed-off-by: Sjoerd Simons <sjoerd.simons@collabora.co.uk>
Signed-off-by: Mark Brown <broonie@kernel.org>
Check if GPIO pin is valid by API helper function.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Use the new snd_pcm_hw_constraint_single() helper function rather than
installing a list constraint with a single value. Since
snd_pcm_hw_constraint_single() sets a static constraint while
snd_pcm_hw_constraint_list() sets a dynamic constraint the former is
slightly more efficient and it also needs less code.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Acked-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Use the new snd_pcm_hw_constraint_single() helper function rather than
installing a list constraint with a single value. Since
snd_pcm_hw_constraint_single() sets a static constraint while
snd_pcm_hw_constraint_list() sets a dynamic constraint the former is
slightly more efficient and it also needs less code.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Acked-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Use the new snd_pcm_hw_constraint_single() helper function rather than
installing a list constraint with a single value. Since
snd_pcm_hw_constraint_single() sets a static constraint while
snd_pcm_hw_constraint_list() sets a dynamic constraint the former is
slightly more efficient and it also needs less code.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Acked-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Use the new snd_pcm_hw_constraint_single() helper function rather than
installing a list constraint with a single value. Since
snd_pcm_hw_constraint_single() sets a static constraint while
snd_pcm_hw_constraint_list() sets a dynamic constraint the former is
slightly more efficient and it also needs less code.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Acked-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Use the new snd_pcm_hw_constraint_single() helper function instead of
calling snd_pcm_hw_constraint_minmax() with the same value for min and max
to install a constraint that limits the possible configuration values to a
single value. Using snd_pcm_hw_constraint_single() makes the indented
result clearer.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Use the new snd_pcm_hw_constraint_single() helper function instead of
calling snd_pcm_hw_constraint_minmax() with the same value for min and max
to install a constraint that limits the possible configuration values to a
single value. Using snd_pcm_hw_constraint_single() makes the indented
result clearer and is slightly shorter.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Use the new snd_pcm_hw_constraint_single() helper function instead of
calling snd_pcm_hw_constraint_minmax() with the same value for min and max
to install a constraint that limits the possible configuration values to a
single value. Using snd_pcm_hw_constraint_single() makes the indented
result clearer and is slightly shorter.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Jarkko Nikula <jarkko.nikula@bitmer.com>
Tested-by: Jarkko Nikula <jarkko.nikula@bitmer.com>
Acked-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
The hci_conn objects don't have a dedicated lock themselves but rely
on the caller to hold the hci_dev lock for most types of access. The
hci_conn_timeout() function has so far sent certain HCI commands based
on the hci_conn state which has been possible without holding the
hci_dev lock.
The recent changes to do LE scanning before connect attempts added
even more operations to hci_conn and hci_dev from hci_conn_timeout,
thereby exposing potential race conditions with the hci_dev and
hci_conn states.
As an example of such a race, here there's a timeout but an
l2cap_sock_connect() call manages to race with the cleanup routine:
[Oct21 08:14] l2cap_chan_timeout: chan ee4b12c0 state BT_CONNECT
[ +0.000004] l2cap_chan_close: chan ee4b12c0 state BT_CONNECT
[ +0.000002] l2cap_chan_del: chan ee4b12c0, conn f3141580, err 111, state BT_CONNECT
[ +0.000002] l2cap_sock_teardown_cb: chan ee4b12c0 state BT_CONNECT
[ +0.000005] l2cap_chan_put: chan ee4b12c0 orig refcnt 4
[ +0.000010] hci_conn_drop: hcon f53d56e0 orig refcnt 1
[ +0.000013] l2cap_chan_put: chan ee4b12c0 orig refcnt 3
[ +0.000063] hci_conn_timeout: hcon f53d56e0 state BT_CONNECT
[ +0.000049] hci_conn_params_del: addr ee:0d:30:09:53:1f (type 1)
[ +0.000002] hci_chan_list_flush: hcon f53d56e0
[ +0.000001] hci_chan_del: hci0 hcon f53d56e0 chan f4e7ccc0
[ +0.004528] l2cap_sock_create: sock e708fc00
[ +0.000023] l2cap_chan_create: chan ee4b1770
[ +0.000001] l2cap_chan_hold: chan ee4b1770 orig refcnt 1
[ +0.000002] l2cap_sock_init: sk ee4b3390
[ +0.000029] l2cap_sock_bind: sk ee4b3390
[ +0.000010] l2cap_sock_setsockopt: sk ee4b3390
[ +0.000037] l2cap_sock_connect: sk ee4b3390
[ +0.000002] l2cap_chan_connect: 00:02:72:d9:e5:8b -> ee:0d:30:09:53:1f (type 2) psm 0x00
[ +0.000002] hci_get_route: 00:02:72:d9:e5:8b -> ee:0d:30:09:53:1f
[ +0.000001] hci_dev_hold: hci0 orig refcnt 8
[ +0.000003] hci_conn_hold: hcon f53d56e0 orig refcnt 0
Above the l2cap_chan_connect() shouldn't have been able to reach the
hci_conn f53d56e0 anymore but since hci_conn_timeout didn't do proper
locking that's not the case. The end result is a reference to hci_conn
that's not in the conn_hash list, resulting in list corruption when
trying to remove it later:
[Oct21 08:15] l2cap_chan_timeout: chan ee4b1770 state BT_CONNECT
[ +0.000004] l2cap_chan_close: chan ee4b1770 state BT_CONNECT
[ +0.000003] l2cap_chan_del: chan ee4b1770, conn f3141580, err 111, state BT_CONNECT
[ +0.000001] l2cap_sock_teardown_cb: chan ee4b1770 state BT_CONNECT
[ +0.000005] l2cap_chan_put: chan ee4b1770 orig refcnt 4
[ +0.000002] hci_conn_drop: hcon f53d56e0 orig refcnt 1
[ +0.000015] l2cap_chan_put: chan ee4b1770 orig refcnt 3
[ +0.000038] hci_conn_timeout: hcon f53d56e0 state BT_CONNECT
[ +0.000003] hci_chan_list_flush: hcon f53d56e0
[ +0.000002] hci_conn_hash_del: hci0 hcon f53d56e0
[ +0.000001] ------------[ cut here ]------------
[ +0.000461] WARNING: CPU: 0 PID: 1782 at lib/list_debug.c:56 __list_del_entry+0x3f/0x71()
[ +0.000839] list_del corruption, f53d56e0->prev is LIST_POISON2 (00000200)
The necessary fix is unfortunately more complicated than just adding
hci_dev_lock/unlock calls to the hci_conn_timeout() call path.
Particularly, the hci_conn_del() API, which expects the hci_dev lock to
be held, performs a cancel_delayed_work_sync(&hcon->disc_work) which
would lead to a deadlock if the hci_conn_timeout() call path tries to
acquire the same lock.
This patch solves the problem by deferring the cleanup work to a
separate work callback. To protect against the hci_dev or hci_conn
going away meanwhile temporary references are taken with the help of
hci_dev_hold() and hci_conn_get().
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Cc: stable@vger.kernel.org # 4.3
Use the new snd_pcm_hw_constraint_single() helper function instead of
calling snd_pcm_hw_constraint_minmax() with the same value for min and max
to install a constraint that limits the possible configuration values to a
single value. Using snd_pcm_hw_constraint_single() makes the indented
result clearer and is slightly shorter.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Jarkko Nikula <jarkko.nikula@bitmer.com>
Acked-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Use the new snd_pcm_hw_constraint_single() helper function instead of
calling snd_pcm_hw_constraint_minmax() with the same value for min and max
to install a constraint that limits the possible configuration values to a
single value. Using snd_pcm_hw_constraint_single() makes the indented
result clearer.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Use the new snd_pcm_hw_constraint_single() helper function instead of
calling snd_pcm_hw_constraint_minmax() with the same value for min and max
to install a constraint that limits the possible configuration values to a
single value. Using snd_pcm_hw_constraint_single() makes the indented
result clearer and is slightly shorter.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Use the new snd_pcm_hw_constraint_single() helper function instead of
calling snd_pcm_hw_constraint_minmax() with the same value for min and max
to install a constraint that limits the possible configuration values to a
single value. Using snd_pcm_hw_constraint_single() makes the indented
result clearer and is slightly shorter.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Acked-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Use the new snd_pcm_hw_constraint_single() helper function instead of
calling snd_pcm_hw_constraint_minmax() with the same value for min and max
to install a constraint that limits the possible configuration values to a
single value. Using snd_pcm_hw_constraint_single() makes the indented
result clearer.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Use the new snd_pcm_hw_constraint_single() helper function instead of
calling snd_pcm_hw_constraint_minmax() with the same value for min and max
to install a constraint that limits the possible configuration values to a
single value. Using snd_pcm_hw_constraint_single() makes the indented
result clearer.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Use the new snd_pcm_hw_constraint_single() helper function instead of
calling snd_pcm_hw_constraint_minmax() with the same value for min and max
to install a constraint that limits the possible configuration values to a
single value. Using snd_pcm_hw_constraint_single() makes the indented
result clearer.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Use the new snd_pcm_hw_constraint_single() helper function instead of
calling snd_pcm_hw_constraint_minmax() with the same value for min and max
to install a constraint that limits the possible configuration values to a
single value. Using snd_pcm_hw_constraint_single() makes the indented
result clearer.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Use the new snd_pcm_hw_constraint_single() helper function instead of
calling snd_pcm_hw_constraint_minmax() with the same value for min and max
to install a constraint that limits the possible configuration values to a
single value. Using snd_pcm_hw_constraint_single() makes the indented
result clearer.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Use the new snd_pcm_hw_constraint_single() helper function instead of
calling snd_pcm_hw_constraint_minmax() with the same value for min and max
to install a constraint that limits the possible configuration values to a
single value. Using snd_pcm_hw_constraint_single() makes the indented
result clearer.
While we are at it also fix some code style issues in the affected lines.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
