linux-toradex.git/Documentation, branch v3.12.11

mm, oom: base root bonus on current usage

2014-02-13T21:50:19+00:00

commit 778c14affaf94a9e4953179d3e13a544ccce7707 upstream.

A 3% of system memory bonus is sometimes too excessive in comparison to
other processes.

With commit a63d83f427fb ("oom: badness heuristic rewrite"), the OOM
killer tries to avoid killing privileged tasks by subtracting 3% of
overall memory (system or cgroup) from their per-task consumption.  But
as a result, all root tasks that consume less than 3% of overall memory
are considered equal, and so it only takes 33+ privileged tasks pushing
the system out of memory for the OOM killer to do something stupid and
kill dhclient or other root-owned processes.  For example, on a 32G
machine it can't tell the difference between the 1M agetty and the 10G
fork bomb member.

The changelog describes this 3% boost as the equivalent to the global
overcommit limit being 3% higher for privileged tasks, but this is not
the same as discounting 3% of overall memory from _every privileged task
individually_ during OOM selection.

Replace the 3% of system memory bonus with a 3% of current memory usage
bonus.

By giving root tasks a bonus that is proportional to their actual size,
they remain comparable even when relatively small.  In the example
above, the OOM killer will discount the 1M agetty's 256 badness points
down to 179, and the 10G fork bomb's 262144 points down to 183500 points
and make the right choice, instead of discounting both to 0 and killing
agetty because it's first in the task list.

Signed-off-by: David Rientjes 
Reported-by: Johannes Weiner 
Acked-by: Johannes Weiner 
Cc: Michal Hocko 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

i2c: piix4: Add support for AMD ML and CZ SMBus changes

2014-02-06T19:22:20+00:00

commit 032f708bc4f6da868ec49dac48ddf3670d8035d3 upstream.

The locations of SMBus register base address and enablement bit are changed
from AMD ML, which need this patch to be supported.

Signed-off-by: Shane Huang 
Reviewed-by: Jean Delvare 
Signed-off-by: Wolfram Sang 
Signed-off-by: Greg Kroah-Hartman

i2c: mv64xxx: Document the newly introduced Armada XP A0 compatible

2014-02-06T19:22:19+00:00

commit f8b94beb7e6a374cb0de531b72377c49857b35ca upstream.

The first variants of Armada XP SoCs (A0 stepping) have issues related
to the i2c controller which prevent to use the offload mechanism and
lead to a kernel hang during boot.

The commit introduces a new the compatible string
marvell,mv78230-a0-i2c for the i2c controller.

Signed-off-by: Gregory CLEMENT 
Acked-by: Arnd Bergmann 
cc: devicetree@vger.kernel.org
Fixes: 930ab3d403ae (i2c: mv64xxx: Add I2C Transaction Generator support)
Signed-off-by: Jason Cooper 
Signed-off-by: Greg Kroah-Hartman

ata: sata_mv: introduce compatible string "marvell, armada-370-sata"

2014-02-06T19:22:19+00:00

commit b1f5c73bd5a4752efb7d7af019034044b08aafe9 upstream.

The sata_mv driver supports the SATA IP found in several Marvell SoCs.
As some new SATA registers have been introduced with the Armada 370/XP
SoCs, a way to identify them is needed.

This patch introduces a new compatible string for the SATA IP found in
Armada 370/XP SoCs.

Signed-off-by: Simon Guinot 
Cc: Thomas Petazzoni 
Cc: Jason Cooper 
Cc: Andrew Lunn 
Cc: Gregory Clement 
Cc: Sebastian Hesselbarth 
Cc: Lior Amsalem 
Acked-by: Jason Cooper 
Signed-off-by: Tejun Heo 
Signed-off-by: Greg Kroah-Hartman

clk: samsung: exynos5250: Add MDMA0 clocks

2014-01-15T23:31:42+00:00

commit 8fb9aeb7a71ef4f3e0613d459a2e1366a7a90469 upstream.

Adds gate clock for MDMA0 on Exynos5250 SoC. This is needed to ensure
that the clock is enabled when MDMA0 is used on systems on which
firmware gates the clockby default.

Signed-off-by: Abhilash Kesavan 
Acked-by: Mike Turquette 
[t.figa: Updated patch description.]
Signed-off-by: Tomasz Figa 
Signed-off-by: Greg Kroah-Hartman

packet: fix send path when running with proto == 0

2014-01-15T23:31:34+00:00

[ Upstream commit 66e56cd46b93ef407c60adcac62cf33b06119d50 ]

Commit e40526cb20b5 introduced a cached dev pointer, that gets
hooked into register_prot_hook(), __unregister_prot_hook() to
update the device used for the send path.

We need to fix this up, as otherwise this will not work with
sockets created with protocol = 0, plus with sll_protocol = 0
passed via sockaddr_ll when doing the bind.

So instead, assign the pointer directly. The compiler can inline
these helper functions automagically.

While at it, also assume the cached dev fast-path as likely(),
and document this variant of socket creation as it seems it is
not widely used (seems not even the author of TX_RING was aware
of that in his reference example [1]). Tested with reproducer
from e40526cb20b5.

 [1] http://wiki.ipxwarzone.com/index.php5?title=Linux_packet_mmap#Example

Fixes: e40526cb20b5 ("packet: fix use after free race in send path when dev is released")
Signed-off-by: Daniel Borkmann 
Tested-by: Salam Noureddine 
Tested-by: Jesper Dangaard Brouer 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

libata: disable a disk via libata.force params

2014-01-09T20:25:12+00:00

commit b8bd6dc36186fe99afa7b73e9e2d9a98ad5c4865 upstream.

A user on StackExchange had a failing SSD that's soldered directly
onto the motherboard of his system. The BIOS does not give any option
to disable it at all, so he can't just hide it from the OS via the
BIOS.

The old IDE layer had hdX=noprobe override for situations like this,
but that was never ported to the libata layer.

This patch implements a disable flag for libata.force.

Example use:

 libata.force=2.0:disable

[v2 of the patch, removed the nodisable flag per Tejun Heo]

Signed-off-by: Robin H. Johnson 
Signed-off-by: Tejun Heo 
Link: http://unix.stackexchange.com/questions/102648/how-to-tell-linux-kernel-3-0-to-completely-ignore-a-failing-disk
Link: http://askubuntu.com/questions/352836/how-can-i-tell-linux-kernel-to-completely-ignore-a-disk-as-if-it-was-not-even-co
Link: http://superuser.com/questions/599333/how-to-disable-kernel-probing-for-drive
Signed-off-by: Greg Kroah-Hartman

tcp: tsq: restore minimal amount of queueing

2013-12-08T15:29:12+00:00

[ Upstream commit 98e09386c0ef4dfd48af7ba60ff908f0d525cdee ]

After commit c9eeec26e32e ("tcp: TSQ can use a dynamic limit"), several
users reported throughput regressions, notably on mvneta and wifi
adapters.

802.11 AMPDU requires a fair amount of queueing to be effective.

This patch partially reverts the change done in tcp_write_xmit()
so that the minimal amount is sysctl_tcp_limit_output_bytes.

It also remove the use of this sysctl while building skb stored
in write queue, as TSO autosizing does the right thing anyway.

Users with well behaving NICS and correct qdisc (like sch_fq),
can then lower the default sysctl_tcp_limit_output_bytes value from
128KB to 8KB.

This new usage of sysctl_tcp_limit_output_bytes permits each driver
authors to check how their driver performs when/if the value is set
to a minimum of 4KB.

Normally, line rate for a single TCP flow should be possible,
but some drivers rely on timers to perform TX completion and
too long TX completion delays prevent reaching full throughput.

Fixes: c9eeec26e32e ("tcp: TSQ can use a dynamic limit")
Signed-off-by: Eric Dumazet 
Reported-by: Sujith Manoharan 
Reported-by: Arnaud Ebalard 
Tested-by: Sujith Manoharan 
Cc: Felix Fietkau 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

vsprintf: check real user/group id for %pK

2013-12-04T19:05:12+00:00

commit 312b4e226951f707e120b95b118cbc14f3d162b2 upstream.

Some setuid binaries will allow reading of files which have read
permission by the real user id.  This is problematic with files which
use %pK because the file access permission is checked at open() time,
but the kptr_restrict setting is checked at read() time.  If a setuid
binary opens a %pK file as an unprivileged user, and then elevates
permissions before reading the file, then kernel pointer values may be
leaked.

This happens for example with the setuid pppd application on Ubuntu 12.04:

  $ head -1 /proc/kallsyms
  00000000 T startup_32

  $ pppd file /proc/kallsyms
  pppd: In file /proc/kallsyms: unrecognized option 'c1000000'

This will only leak the pointer value from the first line, but other
setuid binaries may leak more information.

Fix this by adding a check that in addition to the current process having
CAP_SYSLOG, that effective user and group ids are equal to the real ids.
If a setuid binary reads the contents of a file which uses %pK then the
pointer values will be printed as NULL if the real user is unprivileged.

Update the sysctl documentation to reflect the changes, and also correct
the documentation to state the kptr_restrict=0 is the default.

This is a only temporary solution to the issue.  The correct solution is
to do the permission check at open() time on files, and to replace %pK
with a function which checks the open() time permission.  %pK uses in
printk should be removed since no sane permission check can be done, and
instead protected by using dmesg_restrict.

Signed-off-by: Ryan Mallon 
Cc: Kees Cook 
Cc: Alexander Viro 
Cc: Joe Perches 
Cc: "Eric W. Biederman" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2013-10-23T06:47:42+00:00

Pull networking fixes from David Miller:
 "Sorry I let so much accumulate, I was in Buffalo and wanted a few
  things to cook in my tree for a while before sending to you.  Anyways,
  it's a lot of little things as usual at this stage in the game"

 1) Make bonding MAINTAINERS entry reflect reality, from Andy
    Gospodarek.

 2) Fix accidental sock_put() on timewait mini sockets, from Eric
    Dumazet.

 3) Fix crashes in l2tp due to mis-handling of ipv4 mapped ipv6
    addresses, from François CACHEREUL.

 4) Fix heap overflow in __audit_sockaddr(), from the eagle eyed Dan
    Carpenter.

 5) tcp_shifted_skb() doesn't take handle FINs properly, from Eric
    Dumazet.

 6) SFC driver bug fixes from Ben Hutchings.

 7) Fix TX packet scheduling wedge after channel change in ath9k driver,
    from Felix Fietkau.

 8) Fix user after free in BPF JIT code, from Alexei Starovoitov.

 9) Source address selection test is reversed in
    __ip_route_output_key(), fix from Jiri Benc.

10) VLAN and CAN layer mis-size netlink attributes, from Marc
    Kleine-Budde.

11) Fix permission checks in sysctls to use current_euid() instead of
    current_uid().  From Eric W Biederman.

12) IPSEC policies can go away while a timer is still pending for them,
    add appropriate ref-counting to fix, from Steffen Klassert.

13) Fix mis-programming of FDR and RMCR registers on R8A7740 sh_eth
    chips, from Nguyen Hong Ky and Simon Horman.

14) MLX4 forgets to DMA unmap pages on RX, fix from Amir Vadai.

15) IPV6 GRE tunnel MTU upper limit is miscalculated, from Oussama
    Ghorbel.

16) Fix typo in fq_change(), we were assigning "initial quantum" to
    "quantum".  From Eric Dumazet.

17) Set a more appropriate sk_pacing_rate for non-TCP sockets, otherwise
    FQ packet scheduler does not pace those flows properly.  Also from
    Eric Dumazet.

18) rtlwifi miscalculates packet pointers, from Mark Cave-Ayland.

19) l2tp_xmit_skb() can be called from process context, not just softirq
    context, so we must always make sure to BH disable around it.  From
    Eric Dumazet.

20) On qdisc reset, we forget to purge the RB tree of SKBs in netem
    packet scheduler.  From Stephen Hemminger.

21) Fix info leak in farsync WAN driver ioctl() handler, from Dan
    Carpenter and Salva Peiró.

22) Fix PHY reset and other issues in dm9000 driver, from Nikita
    Kiryanov and Michael Abbott.

23) When hardware can do SCTP crc32 checksums, we accidently don't
    disable the csum offload when IPSEC transformations have been
    applied.  From Fan Du and Vlad Yasevich.

24) Tail loss probing in TCP leaves the socket in the wrong congestion
    avoidance state.  From Yuchung Cheng.

25) In CPSW driver, enable NAPI before interrupts are turned on, from
    Markus Pargmann.

26) Integer underflow and dual-assignment in YAM hamradio driver, from
    Dan Carpenter.

27) If we are going to mangle a packet in tcp_set_skb_tso_segs() we must
    unclone it.  This fixes various hard to track down crashes in
    drivers where the SKBs ->gso_segs was changing right from underneath
    the driver during TX queueing.  From Eric Dumazet.

28) Fix the handling of VLAN IDs, and in particular the special IDs 0
    and 4095, in the bridging layer.  From Toshiaki Makita.

29) Another info leak, this time in wanxl WAN driver, from Salva Peiró.

30) Fix race in socket credential passing, from Daniel Borkmann.

31) WHen NETLABEL is disabled, we don't validate CIPSO packets properly,
    from Seif Mazareeb.

32) Fix identification of fragmented frames in ipv4/ipv6 UDP
    Fragmentation Offload output paths, from Jiri Pirko.

33) Virtual Function fixes in bnx2x driver from Yuval Mintz and Ariel
    Elior.

34) When we removed the explicit neighbour pointer from ipv6 routes a
    slight regression was introduced for users such as IPVS, xt_TEE, and
    raw sockets.  We mix up the users requested destination address with
    the routes assigned nexthop/gateway.  From Julian Anastasov and
    Simon Horman.

35) Fix stack overruns in rt6_probe(), the issue is that can end up
    doing two full packet xmit paths at the same time when emitting
    neighbour discovery messages.  From Hannes Frederic Sowa.

36) davinci_emac driver doesn't handle IFF_ALLMULTI correctly, from
    Mariusz Ceier.

37) Make sure to set TCP sk_pacing_rate after the first legitimate RTT
    sample, from Neal Cardwell.

38) Wrong netlink attribute passed to xfrm_replay_verify_len(), from
    Steffen Klassert.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (152 commits)
  ax88179_178a: Add VID:DID for Samsung USB Ethernet Adapter
  ax88179_178a: Correct the RX error definition in RX header
  Revert "bridge: only expire the mdb entry when query is received"
  tcp: initialize passive-side sk_pacing_rate after 3WHS
  davinci_emac.c: Fix IFF_ALLMULTI setup
  mac802154: correct a typo in ieee802154_alloc_device() prototype
  ipv6: probe routes asynchronous in rt6_probe
  netfilter: nf_conntrack: fix rt6i_gateway checks for H.323 helper
  ipv6: fill rt6i_gateway with nexthop address
  ipv6: always prefer rt6i_gateway if present
  bnx2x: Set NETIF_F_HIGHDMA unconditionally
  bnx2x: Don't pretend during register dump
  bnx2x: Lock DMAE when used by statistic flow
  bnx2x: Prevent null pointer dereference on error flow
  bnx2x: Fix config when SR-IOV and iSCSI are enabled
  bnx2x: Fix Coalescing configuration
  bnx2x: Unlock VF-PF channel on MAC/VLAN config error
  bnx2x: Prevent an illegal pointer dereference during panic
  bnx2x: Fix Maximum CoS estimation for VFs
  drivers: net: cpsw: fix kernel warn during iperf test with interrupt pacing
  ...