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When there is no remote AMP controller found fallback to normal
L2CAP sequence.
Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
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When receiving HCI Command Status after HCI Create Physical Link
execute HCI Write Remote AMP Assoc command to AMP controller.
Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
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When receiving A2MP Get AMP Assoc Response execute HCI Create Physical
Link to AMP controller. Define function which will run when receiving
HCI Command Status.
Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
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Function calculates AMP keys using hmac_sha256 helper. Calculated keys
are Generic AMP Link Key (gamp) and Dedicated AMP Link Key with
keyID "802b" for 802.11 PAL.
Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
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Choose which L2CAP connection to establish by checking support
for HS and remote side supported features.
Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
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Create remote AMP controllers structure. It is used to keep information
about discovered remote AMP controllers by A2MP protocol.
Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
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Define physical link structures. Physical links are represented by
hci_conn structure. For BR/EDR we use type ACL_LINK and for AMP
we use AMP_LINK.
Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
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When receiving A2MP Get AMP Assoc Request execute Read Local AMP Assoc
HCI command to AMP controller. If the AMP Assoc data is larger than it
can fit to HCI event only fragment is read. When all fragments are read
send A2MP Get AMP Assoc Response.
Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
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When receiving A2MP Get Info Request execute Read Local AMP Info HCI
command to AMP controller with function to be executed upon receiving
command complete event. Function will handle A2MP Get Info Response.
Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
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Create amp_mgr_list global list which will be used by different
hci devices to find amp_mgr.
Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
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Add a few definitions to hci.h
Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
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git://git.kernel.org/pub/scm/linux/kernel/git/jberg/mac80211-next
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xmit callback provided by a driver encapsulates upper layers
data and sends it to the hardware. So, HCI does not know the
exact amount of data being sent and thus can't handle partially
sent frames properly.
Therefore, the driver must return 0 for completely sent frame or
negative for failure.
Signed-off-by: Waldemar Rymarkiewicz <waldemar.rymarkiewicz@tieto.com>
Acked-by: Eric Lapuyade <eric.lapuyade@intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
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The previous shdlc HCI driver and its header are removed from the tree.
PN544 now registers directly with HCI and passes the name of the llc it
requires (shdlc).
HCI instantiation now allocates the required llc instance. The llc is
started when the HCI device is brought up.
Signed-off-by: Eric Lapuyade <eric.lapuyade@intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
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This is used by HCI drivers such as the one for the pn544 which require
communications between HCI and the chip to use shdlc.
Signed-off-by: Eric Lapuyade <eric.lapuyade@intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
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This is a passthrough llc. It can be used by HCI drivers that don't
need link layer control. HCI will then write directly to the driver, and
driver will deliver incoming frames directly to HCI without any
processing.
Signed-off-by: Eric Lapuyade <eric.lapuyade@intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
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The LLC layer manages modules that control the link layer protocol (such
as shdlc) between HCI and an HCI driver. The driver must simply specify
the required llc when it registers with HCI.
Signed-off-by: Eric Lapuyade <eric.lapuyade@intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
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This enables the completion callback to be called from a different
context, preventing a possible deadlock if the callback resulted in the
invocation of a nested call to the currently locked nfc_dev.
This is also more in line with the im_transceive nfc_ops for NFC Core or
NCI drivers which already behave asynchronously.
Signed-off-by: Eric Lapuyade <eric.lapuyade@intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
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This method initiates execution of an HCI cmd. Result will be delivered
through an asynchronous callback.
Signed-off-by: Eric Lapuyade <eric.lapuyade@intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
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NFC is using a number of custom ordered workqueues w/ WQ_MEM_RECLAIM.
WQ_MEM_RECLAIM is unnecessary unless NFC is gonna be used as transport
for storage device, and all use cases match one work item to one
ordered workqueue - IOW, there's no actual ordering going on at all
and using system_nrt_wq gives the same behavior.
There's nothing to be gained by using custom workqueues. Use
system_nrt_wq instead and drop all the custom ones.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
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During NFC-DEP target activation, store the remote
general bytes to be used later in dep_link_up.
When dep_link_up is called, activate the NFC-DEP target,
and forward the remote general bytes.
When dep_link_down is called, deactivate the target.
Signed-off-by: Ilan Elias <ilane@ti.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
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Signed-off-by: Ilan Elias <ilane@ti.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
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If initiator protocol is NFC-DEP, set the local general bytes
in nci_start_poll.
Signed-off-by: Ilan Elias <ilane@ti.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
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We currently use a per socket order-0 page cache for tcp_sendmsg()
operations.
This page is used to build fragments for skbs.
Its done to increase probability of coalescing small write() into
single segments in skbs still in write queue (not yet sent)
But it wastes a lot of memory for applications handling many mostly
idle sockets, since each socket holds one page in sk->sk_sndmsg_page
Its also quite inefficient to build TSO 64KB packets, because we need
about 16 pages per skb on arches where PAGE_SIZE = 4096, so we hit
page allocator more than wanted.
This patch adds a per task frag allocator and uses bigger pages,
if available. An automatic fallback is done in case of memory pressure.
(up to 32768 bytes per frag, thats order-3 pages on x86)
This increases TCP stream performance by 20% on loopback device,
but also benefits on other network devices, since 8x less frags are
mapped on transmit and unmapped on tx completion. Alexander Duyck
mentioned a probable performance win on systems with IOMMU enabled.
Its possible some SG enabled hardware cant cope with bigger fragments,
but their ndo_start_xmit() should already handle this, splitting a
fragment in sub fragments, since some arches have PAGE_SIZE=65536
Successfully tested on various ethernet devices.
(ixgbe, igb, bnx2x, tg3, mellanox mlx4)
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Ben Hutchings <bhutchings@solarflare.com>
Cc: Vijay Subramanian <subramanian.vijay@gmail.com>
Cc: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Vijay Subramanian <subramanian.vijay@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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All callers provide a non-NULL scm argument.
Signed-off-by: David S. Miller <davem@davemloft.net>
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git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth-next
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git://git.kernel.org/pub/scm/linux/kernel/git/jberg/mac80211-next
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When taking SYNACK RTT samples for servers using TCP Fast Open, fix
the code to ensure that we only call tcp_valid_rtt_meas() after we
receive the ACK that completes the 3-way handshake.
Previously we were always taking an RTT sample in
tcp_v4_syn_recv_sock(). However, for TCP Fast Open connections
tcp_v4_conn_req_fastopen() calls tcp_v4_syn_recv_sock() at the time we
receive the SYN. So for TFO we must wait until tcp_rcv_state_process()
to take the RTT sample.
To fix this, we wait until after TFO calls tcp_v4_syn_recv_sock()
before we set the snt_synack timestamp, since tcp_synack_rtt_meas()
already ensures that we only take a SYNACK RTT sample if snt_synack is
non-zero. To be careful, we only take a snt_synack timestamp when
a SYNACK transmit or retransmit succeeds.
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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In preparation for adding another spot where we compute the SYNACK
RTT, extract this code so that it can be shared.
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Pull networking updates from David Miller:
"More bug fixes, nothing gets past these guys"
1) More kernel info leaks found by Mathias Krause, this time in the
IPSEC configuration layers.
2) When IPSEC policies change, we do not properly make sure that cached
routes (which could now be stale) throughout the system will be
revalidated. Fix this by generalizing the generation count
invalidation scheme used by ipv4. From Nicolas Dichtel.
3) When repairing TCP sockets, we need to allow to restore not just the
send window scale, but the receive one too. Extend the existing
interface to achieve this in a backwards compatible way. From
Andrey Vagin.
4) A fix for FCOE scatter gather feature validation erroneously caused
scatter gather to be disabled for things like AOE too. From Ed L
Cashin.
5) Several cases of mishandling of error pointers, from Mathias Krause,
Wei Yongjun, and Devendra Naga.
6) Fix gianfar build, from Richard Cochran.
7) CAP_NET_* failures should return -EPERM not -EACCES, from Zhao
Hongjiang.
8) Hardware reset fix in janz-ican3 CAN driver, from Ira W Snyder.
9) Fix oops during rmmod in ti_hecc CAN driver, from Marc Kleine-Budde.
10) The removal of the conditional compilation of the clk support code
in the stmmac driver broke things. This is because the interfaces
used are the ones that don't also perform the enable/disable of the
clk. Fix from Stefan Roese.
11) The QFQ packet scheduler can record out of range virtual start
times, resulting later in misbehavior and even crashes. Fix from
Paolo Valente.
12) If MSG_WAITALL is used with IOAT DMA under TCP, we can wedge the
receiver when the advertised receive window goes to zero. Detect
this case and force the processing of the IOAT DMA queue when it
happens to avoid getting stuck. Fix from Michal Kubecek.
13) batman-adv assumes that test_bit() returns only 0 or 1, but this is
not true for x86 (which returns -1 or 0, via the 'sbb' instruction).
Fix from Linus Lussing.
14) Fix small packet corruption in e1000, from Tushar Dave.
15) make_blackhole() in the IPSEC policy code can do one read unlock too
many, fix from Li RongQing.
16) The new tcp_try_coalesce() code introduced a bug in TCP URG
handling, fix from Eric Dumazet.
17) Fix memory leak in __netif_receive_skb() when doing zerocopy and
when hit an OOM condition. From Michael S Tsirkin.
18) netxen blindly deferences pdev->bus->self, which is not guarenteed
to be non-NULL. Fix from Nikolay Aleksandrov.
19) Fix a performance regression caused by mistakes in ipv6 checksum
validation in the bnx2x driver, fix from Michal Schmidt.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (45 commits)
net/stmmac: Use clk_prepare_enable and clk_disable_unprepare
net: change return values from -EACCES to -EPERM
net/irda: sh_sir: fix return value check in sh_sir_set_baudrate()
stmmac: fix return value check in stmmac_open_ext_timer()
gianfar: fix phc index build failure
ipv6: fix return value check in fib6_add()
bnx2x: remove false warning regarding interrupt number
can: ti_hecc: fix oops during rmmod
can: janz-ican3: fix support for older hardware revisions
net: do not disable sg for packets requiring no checksum
aoe: assert AoE packets marked as requiring no checksum
at91ether: return PTR_ERR if call to clk_get fails
xfrm_user: don't copy esn replay window twice for new states
xfrm_user: ensure user supplied esn replay window is valid
xfrm_user: fix info leak in copy_to_user_tmpl()
xfrm_user: fix info leak in copy_to_user_policy()
xfrm_user: fix info leak in copy_to_user_state()
xfrm_user: fix info leak in copy_to_user_auth()
net: qmi_wwan: adding Huawei E367, ZTE MF683 and Pantech P4200
tcp: restore rcv_wscale in a repair mode (v2)
...
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Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Michal Kubeček <mkubecek@suse.cz>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Michal Kubeček <mkubecek@suse.cz>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Two years ago, Shan Wei tried to fix this:
http://patchwork.ozlabs.org/patch/43905/
The problem is that RFC2460 requires an ICMP Time
Exceeded -- Fragment Reassembly Time Exceeded message should be
sent to the source of that fragment, if the defragmentation
times out.
"
If insufficient fragments are received to complete reassembly of a
packet within 60 seconds of the reception of the first-arriving
fragment of that packet, reassembly of that packet must be
abandoned and all the fragments that have been received for that
packet must be discarded. If the first fragment (i.e., the one
with a Fragment Offset of zero) has been received, an ICMP Time
Exceeded -- Fragment Reassembly Time Exceeded message should be
sent to the source of that fragment.
"
As Herbert suggested, we could actually use the standard IPv6
reassembly code which follows RFC2460.
With this patch applied, I can see ICMP Time Exceeded sent
from the receiver when the sender sent out 3/4 fragmented
IPv6 UDP packet.
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Michal Kubeček <mkubecek@suse.cz>
Cc: David Miller <davem@davemloft.net>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: netfilter-devel@vger.kernel.org
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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As pointed by Michal, it is necessary to add a new
namespace for nf_conntrack_reasm code, this prepares
for the second patch.
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Michal Kubeček <mkubecek@suse.cz>
Cc: David Miller <davem@davemloft.net>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: netfilter-devel@vger.kernel.org
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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The name can't be modified by the driver,
make it const.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
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This patch adds support for Secure Simple Pairing with devices that have
KeyboardOnly as their IO capability. Such devices will cause a passkey
notification on our side and optionally also keypress notifications.
Without this patch some keyboards cannot be paired using the mgmt
interface.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Cc: stable@vger.kernel.org
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
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IPv6 dst should take care of rt_genid too. When a xfrm policy is inserted or
deleted, all dst should be invalidated.
To force the validation, dst entries should be created with ->obsolete set to
DST_OBSOLETE_FORCE_CHK. This was already the case for all functions calling
ip6_dst_alloc(), except for ip6_rt_copy().
As a consequence, we can remove the specific code in inet6_connection_sock.
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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This commit prepares the use of rt_genid by both IPv4 and IPv6.
Initialization is left in IPv4 part.
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Since route cache deletion (89aef8921bfbac22f), delay is no
more used. Remove it.
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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In AP mode, when a station requests connection to an AP and if the
request is failed for particular reason, userspace is notified about the
failure through NL80211_CMD_CONN_FAILED command. Reason for the failure
is sent through the attribute NL80211_ATTR_CONN_FAILED_REASON.
Signed-off-by: Pandiyarajan Pitchaimuthu <c_ppitch@qca.qualcomm.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
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The kerneldoc comment for .sched_scan_stop() callback describes a
driver_initiated flag, but the interface does not hold such a flag.
Reviewed-by: Franky (Zhenhui) Lin <frankyl@broadcom.com>
Reviewed-by: Hante Meuleman <meuleman@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
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Always store audit loginuids in type kuid_t.
Print loginuids by converting them into uids in the appropriate user
namespace, and then printing the resulting uid.
Modify audit_get_loginuid to return a kuid_t.
Modify audit_set_loginuid to take a kuid_t.
Modify /proc/<pid>/loginuid on read to convert the loginuid into the
user namespace of the opener of the file.
Modify /proc/<pid>/loginud on write to convert the loginuid
rom the user namespace of the opener of the file.
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Cc: Paul Moore <paul@paul-moore.com> ?
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
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This warning:
In file included from linux/include/linux/tcp.h:227:0,
from linux/include/linux/ipv6.h:221,
from linux/include/net/ipv6.h:16,
from linux/include/linux/sunrpc/clnt.h:26,
from linux/net/sunrpc/stats.c:22:
linux/include/net/sock.h: In function `sk_rmem_schedule':
linux/nfs-2.6/include/net/sock.h:1339:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
is seen with gcc (GCC) 4.6.3 20120306 (Red Hat 4.6.3-2) using the
-Wextra option.
Commit c76562b6709f ("netvm: prevent a stream-specific deadlock")
accidentally replaced the "size" parameter of sk_rmem_schedule() with an
unsigned int. This changes the semantics of the comparison in the
return statement.
In sk_wmem_schedule we have syntactically the same comparison, but
"size" is a signed integer. In addition, __sk_mem_schedule() takes a
signed integer for its "size" parameter, so there is an implicit type
conversion in sk_rmem_schedule() anyway.
Revert the "size" parameter back to a signed integer so that the
semantics of the expressions in both sk_[rw]mem_schedule() are exactly
the same.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: David Miller <davem@davemloft.net>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Signed-off-by: David S. Miller <davem@davemloft.net>
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git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next
John W. Linville says:
====================
This is another batch of updates intended for the 3.7 stream.
There are not a lot of large items, but iwlwifi, mwifiex, rt2x00,
ath9k, and brcmfmac all get some attention. Wei Yongjun also provides
a series of small maintenance fixes.
This also includes a pull of the wireless tree in order to satisfy
some prerequisites for later patches.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
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This pulls in the fixes in 3.6-rc6
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Conflicts:
net/netfilter/nfnetlink_log.c
net/netfilter/xt_LOG.c
Rather easy conflict resolution, the 'net' tree had bug fixes to make
sure we checked if a socket is a time-wait one or not and elide the
logging code if so.
Whereas on the 'net-next' side we are calculating the UID and GID from
the creds using different interfaces due to the user namespace changes
from Eric Biederman.
Signed-off-by: David S. Miller <davem@davemloft.net>
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git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next into for-davem
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WARNING: With this change it is impossible to load external built
controllers anymore.
In case where CONFIG_NETPRIO_CGROUP=m and CONFIG_NET_CLS_CGROUP=m is
set, corresponding subsys_id should also be a constant. Up to now,
net_prio_subsys_id and net_cls_subsys_id would be of the type int and
the value would be assigned during runtime.
By switching the macro definition IS_SUBSYS_ENABLED from IS_BUILTIN
to IS_ENABLED, all *_subsys_id will have constant value. That means we
need to remove all the code which assumes a value can be assigned to
net_prio_subsys_id and net_cls_subsys_id.
A close look is necessary on the RCU part which was introduces by
following patch:
commit f845172531fb7410c7fb7780b1a6e51ee6df7d52
Author: Herbert Xu <herbert@gondor.apana.org.au> Mon May 24 09:12:34 2010
Committer: David S. Miller <davem@davemloft.net> Mon May 24 09:12:34 2010
cls_cgroup: Store classid in struct sock
Tis code was added to init_cgroup_cls()
/* We can't use rcu_assign_pointer because this is an int. */
smp_wmb();
net_cls_subsys_id = net_cls_subsys.subsys_id;
respectively to exit_cgroup_cls()
net_cls_subsys_id = -1;
synchronize_rcu();
and in module version of task_cls_classid()
rcu_read_lock();
id = rcu_dereference(net_cls_subsys_id);
if (id >= 0)
classid = container_of(task_subsys_state(p, id),
struct cgroup_cls_state, css)->classid;
rcu_read_unlock();
Without an explicit explaination why the RCU part is needed. (The
rcu_deference was fixed by exchanging it to rcu_derefence_index_check()
in a later commit, but that is a minor detail.)
So here is my pondering why it was introduced and why it safe to
remove it now. Note that this code was copied over to net_prio the
reasoning holds for that subsystem too.
The idea behind the RCU use for net_cls_subsys_id is to make sure we
get a valid pointer back from task_subsys_state(). task_subsys_state()
is just blindly accessing the subsys array and returning the
pointer. Obviously, passing in -1 as id into task_subsys_state()
returns an invalid value (out of lower bound).
So this code makes sure that only after module is loaded and the
subsystem registered, the id is assigned.
Before unregistering the module all old readers must have left the
critical section. This is done by assigning -1 to the id and issuing a
synchronized_rcu(). Any new readers wont call task_subsys_state()
anymore and therefore it is safe to unregister the subsystem.
The new code relies on the same trick, but it looks at the subsys
pointer return by task_subsys_state() (remember the id is constant
and therefore we allways have a valid index into the subsys
array).
No precautions need to be taken during module loading
module. Eventually, all CPUs will get a valid pointer back from
task_subsys_state() because rebind_subsystem() which is called after
the module init() function will assigned subsys[net_cls_subsys_id] the
newly loaded module subsystem pointer.
When the subsystem is about to be removed, rebind_subsystem() will
called before the module exit() function. In this case,
rebind_subsys() will assign subsys[net_cls_subsys_id] a NULL pointer
and then it calls synchronize_rcu(). All old readers have left by then
the critical section. Any new reader wont access the subsystem
anymore. At this point we are safe to unregister the subsystem. No
synchronize_rcu() call is needed.
Signed-off-by: Daniel Wagner <daniel.wagner@bmw-carit.de>
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Gao feng <gaofeng@cn.fujitsu.com>
Cc: Glauber Costa <glommer@parallels.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: John Fastabend <john.r.fastabend@intel.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: netdev@vger.kernel.org
Cc: cgroups@vger.kernel.org
|
|
task_netprioidx() should not be defined in case the configuration is
CONFIG_NETPRIO_CGROUP=n. The reason is that in a following patch the
net_prio_subsys_id will only be defined if CONFIG_NETPRIO_CGROUP!=n.
When net_prio is not built at all any callee should only get an empty
task_netprioidx() without any references to net_prio_subsys_id.
Signed-off-by: Daniel Wagner <daniel.wagner@bmw-carit.de>
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Cc: Gao feng <gaofeng@cn.fujitsu.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: John Fastabend <john.r.fastabend@intel.com>
Cc: netdev@vger.kernel.org
Cc: cgroups@vger.kernel.org
|
