linux.git/include/linux, branch v4.10.1

ptr_ring: fix race conditions when resizing

2017-02-26T10:09:17+00:00

[ Upstream commit e71695307114335be1ed912f4a347396c2ed0e69 ]

Resizing currently drops consumer lock.  This can cause entries to be
reordered, which isn't good in itself.  More importantly, consumer can
detect a false ring empty condition and block forever.

Further, nesting of consumer within producer lock is problematic for
tun, since it produces entries in a BH, which causes a lock order
reversal:

       CPU0                    CPU1
       ----                    ----
  consume:
  lock(&(&r->consumer_lock)->rlock);
                               resize:
                               local_irq_disable();
                               lock(&(&r->producer_lock)->rlock);
                               lock(&(&r->consumer_lock)->rlock);
  
  produce:
  lock(&(&r->producer_lock)->rlock);

To fix, nest producer lock within consumer lock during resize,
and keep consumer lock during the whole swap operation.

Reported-by: Dmitry Vyukov 
Cc: stable@vger.kernel.org
Cc: "David S. Miller" 
Acked-by: Jason Wang 
Signed-off-by: Michael S. Tsirkin 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

rhashtable: Revert nested table changes.

2017-02-16T03:29:51+00:00

This reverts commits:

6a25478077d987edc5e2f880590a2bc5fcab4441
9dbbfb0ab6680c6a85609041011484e6658e7d3c
40137906c5f55c252194ef5834130383e639536f

It's too risky to put in this late in the release
cycle.  We'll put these changes into the next merge
window instead.

Signed-off-by: David S. Miller

rhashtable: Add nested tables

2017-02-14T03:17:05+00:00

This patch adds code that handles GFP_ATOMIC kmalloc failure on
insertion.  As we cannot use vmalloc, we solve it by making our
hash table nested.  That is, we allocate single pages at each level
and reach our desired table size by nesting them.

When a nested table is created, only a single page is allocated
at the top-level.  Lower levels are allocated on demand during
insertion.  Therefore for each insertion to succeed, only two
(non-consecutive) pages are needed.

After a nested table is created, a rehash will be scheduled in
order to switch to a vmalloced table as soon as possible.  Also,
the rehash code will never rehash into a nested table.  If we
detect a nested table during a rehash, the rehash will be aborted
and a new rehash will be scheduled.

Signed-off-by: Herbert Xu 
Signed-off-by: David S. Miller

bpf: introduce BPF_F_ALLOW_OVERRIDE flag

2017-02-13T02:52:19+00:00

If BPF_F_ALLOW_OVERRIDE flag is used in BPF_PROG_ATTACH command
to the given cgroup the descendent cgroup will be able to override
effective bpf program that was inherited from this cgroup.
By default it's not passed, therefore override is disallowed.

Examples:
1.
prog X attached to /A with default
prog Y fails to attach to /A/B and /A/B/C
Everything under /A runs prog X

2.
prog X attached to /A with allow_override.
prog Y fails to attach to /A/B with default (non-override)
prog M attached to /A/B with allow_override.
Everything under /A/B runs prog M only.

3.
prog X attached to /A with allow_override.
prog Y fails to attach to /A with default.
The user has to detach first to switch the mode.

In the future this behavior may be extended with a chain of
non-overridable programs.

Also fix the bug where detach from cgroup where nothing is attached
was not throwing error. Return ENOENT in such case.

Add several testcases and adjust libbpf.

Fixes: 3007098494be ("cgroup: add support for eBPF programs")
Signed-off-by: Alexei Starovoitov 
Acked-by: Daniel Borkmann 
Acked-by: Tejun Heo 
Acked-by: Daniel Mack 
Signed-off-by: David S. Miller

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

2017-02-10T22:44:49+00:00

Pull networking fixes from David Miller:

 1) If the timing is wrong we can indefinitely stop generating new ipv6
    temporary addresses, from Marcus Huewe.

 2) Don't double free per-cpu stats in ipv6 SIT tunnel driver, from Cong
    Wang.

 3) Put protections in place so that AF_PACKET is not able to submit
    packets which don't even have a link level header to drivers. From
    Willem de Bruijn.

 4) Fix memory leaks in ipv4 and ipv6 multicast code, from Hangbin Liu.

 5) Don't use udp_ioctl() in l2tp code, UDP version expects a UDP socket
    and that doesn't go over very well when it is passed an L2TP one.
    Fix from Eric Dumazet.

 6) Don't crash on NULL pointer in phy_attach_direct(), from Florian
    Fainelli.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
  l2tp: do not use udp_ioctl()
  xen-netfront: Delete rx_refill_timer in xennet_disconnect_backend()
  NET: mkiss: Fix panic
  net: hns: Fix the device being used for dma mapping during TX
  net: phy: Initialize mdio clock at probe function
  igmp, mld: Fix memory leak in igmpv3/mld_del_delrec()
  xen-netfront: Improve error handling during initialization
  sierra_net: Skip validating irrelevant fields for IDLE LSIs
  sierra_net: Add support for IPv6 and Dual-Stack Link Sense Indications
  kcm: fix 0-length case for kcm_sendmsg()
  xen-netfront: Rework the fix for Rx stall during OOM and network stress
  net: phy: Fix PHY module checks and NULL deref in phy_attach_direct()
  net: thunderx: Fix PHY autoneg for SGMII QLM mode
  net: dsa: Do not destroy invalid network devices
  ping: fix a null pointer dereference
  packet: round up linear to header len
  net: introduce device min_header_len
  sit: fix a double free on error path
  lwtunnel: valid encap attr check should return 0 when lwtunnel is disabled
  ipv6: addrconf: fix generation of new temporary addresses

cpumask: use nr_cpumask_bits for parsing functions

2017-02-08T23:41:43+00:00

Commit 513e3d2d11c9 ("cpumask: always use nr_cpu_ids in formatting and
parsing functions") converted both cpumask printing and parsing
functions to use nr_cpu_ids instead of nr_cpumask_bits.  While this was
okay for the printing functions as it just picked one of the two output
formats that we were alternating between depending on a kernel config,
doing the same for parsing wasn't okay.

nr_cpumask_bits can be either nr_cpu_ids or NR_CPUS.  We can always use
nr_cpu_ids but that is a variable while NR_CPUS is a constant, so it can
be more efficient to use NR_CPUS when we can get away with it.
Converting the printing functions to nr_cpu_ids makes sense because it
affects how the masks get presented to userspace and doesn't break
anything; however, using nr_cpu_ids for parsing functions can
incorrectly leave the higher bits uninitialized while reading in these
masks from userland.  As all testing and comparison functions use
nr_cpumask_bits which can be larger than nr_cpu_ids, the parsed cpumasks
can erroneously yield false negative results.

This made the taskstats interface incorrectly return -EINVAL even when
the inputs were correct.

Fix it by restoring the parse functions to use nr_cpumask_bits instead
of nr_cpu_ids.

Link: http://lkml.kernel.org/r/20170206182442.GB31078@htj.duckdns.org
Fixes: 513e3d2d11c9 ("cpumask: always use nr_cpu_ids in formatting and parsing functions")
Signed-off-by: Tejun Heo 
Reported-by: Martin Steigerwald 
Debugged-by: Ben Hutchings 
Cc: 	[4.0+]
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: avoid returning VM_FAULT_RETRY from ->page_mkwrite handlers

2017-02-08T23:41:43+00:00

Some ->page_mkwrite handlers may return VM_FAULT_RETRY as its return
code (GFS2 or Lustre can definitely do this).  However VM_FAULT_RETRY
from ->page_mkwrite is completely unhandled by the mm code and results
in locking and writeably mapping the page which definitely is not what
the caller wanted.

Fix Lustre and block_page_mkwrite_ret() used by other filesystems
(notably GFS2) to return VM_FAULT_NOPAGE instead which results in
bailing out from the fault code, the CPU then retries the access, and we
fault again effectively doing what the handler wanted.

Link: http://lkml.kernel.org/r/20170203150729.15863-1-jack@suse.cz
Signed-off-by: Jan Kara 
Reported-by: Al Viro 
Reviewed-by: Jinshan Xiong 
Cc: Matthew Wilcox 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

net: introduce device min_header_len

2017-02-08T18:56:37+00:00

The stack must not pass packets to device drivers that are shorter
than the minimum link layer header length.

Previously, packet sockets would drop packets smaller than or equal
to dev->hard_header_len, but this has false positives. Zero length
payload is used over Ethernet. Other link layer protocols support
variable length headers. Support for validation of these protocols
removed the min length check for all protocols.

Introduce an explicit dev->min_header_len parameter and drop all
packets below this value. Initially, set it to non-zero only for
Ethernet and loopback. Other protocols can follow in a patch to
net-next.

Fixes: 9ed988cd5915 ("packet: validate variable length ll headers")
Reported-by: Sowmini Varadhan 
Signed-off-by: Willem de Bruijn 
Acked-by: Eric Dumazet 
Acked-by: Sowmini Varadhan 
Signed-off-by: David S. Miller

Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2017-02-04T20:18:01+00:00

Pull irq fixes from Thomas Gleixner:

 - Prevent double activation of interrupt lines, which causes problems
   on certain interrupt controllers

 - Handle the fallout of the above because x86 (ab)uses the activation
   function to reconfigure interrupts under the hood.

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/irq: Make irq activate operations symmetric
  irqdomain: Avoid activating interrupts more than once

Merge tag 'char-misc-4.10-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

2017-02-04T18:44:15+00:00

Pull char/misc driver fixes from Greg KH:
 "Here are two bugfixes that resolve some reported issues. One in the
  firmware loader, that should fix the much-reported problem of crashes
  with it. The other is a hyperv fix for a reported regression.

  Both have been in linux-next for a week or so with no reported issues"

* tag 'char-misc-4.10-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  Drivers: hv: vmbus: finally fix hv_need_to_signal_on_read()
  firmware: fix NULL pointer dereference in __fw_load_abort()