sched: Guarantee new group-entities always have weight

commit 0ac9b1c21874d2490331233b3242085f8151e166 upstream.

Currently, group entity load-weights are initialized to zero. This
admits some races with respect to the first time they are re-weighted in
earlty use. ( Let g[x] denote the se for "g" on cpu "x". )

Suppose that we have root->a and that a enters a throttled state,
immediately followed by a[0]->t1 (the only task running on cpu[0])
blocking:

  put_prev_task(group_cfs_rq(a[0]), t1)
  put_prev_entity(..., t1)
  check_cfs_rq_runtime(group_cfs_rq(a[0]))
  throttle_cfs_rq(group_cfs_rq(a[0]))

Then, before unthrottling occurs, let a[0]->b[0]->t2 wake for the first
time:

  enqueue_task_fair(rq[0], t2)
  enqueue_entity(group_cfs_rq(b[0]), t2)
  enqueue_entity_load_avg(group_cfs_rq(b[0]), t2)
  account_entity_enqueue(group_cfs_ra(b[0]), t2)
  update_cfs_shares(group_cfs_rq(b[0]))
  < skipped because b is part of a throttled hierarchy >
  enqueue_entity(group_cfs_rq(a[0]), b[0])
  ...

We now have b[0] enqueued, yet group_cfs_rq(a[0])->load.weight == 0
which violates invariants in several code-paths. Eliminate the
possibility of this by initializing group entity weight.

Signed-off-by: Paul Turner <pjt@google.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20131016181627.22647.47543.stgit@sword-of-the-dawn.mtv.corp.google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Chris J Arges <chris.j.arges@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
sched: Fix hrtimer_cancel()/rq->lock deadlock

commit 927b54fccbf04207ec92f669dce6806848cbec7d upstream.

__start_cfs_bandwidth calls hrtimer_cancel while holding rq->lock,
waiting for the hrtimer to finish. However, if sched_cfs_period_timer
runs for another loop iteration, the hrtimer can attempt to take
rq->lock, resulting in deadlock.

Fix this by ensuring that cfs_b->timer_active is cleared only if the
_latest_ call to do_sched_cfs_period_timer is returning as idle. Then
__start_cfs_bandwidth can just call hrtimer_try_to_cancel and wait for
that to succeed or timer_active == 1.

Signed-off-by: Ben Segall <bsegall@google.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: pjt@google.com
Link: http://lkml.kernel.org/r/20131016181622.22647.16643.stgit@sword-of-the-dawn.mtv.corp.google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Chris J Arges <chris.j.arges@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
sched: Fix cfs_bandwidth misuse of hrtimer_expires_remaining

commit db06e78cc13d70f10877e0557becc88ab3ad2be8 upstream.

hrtimer_expires_remaining does not take internal hrtimer locks and thus
must be guarded against concurrent __hrtimer_start_range_ns (but
returning HRTIMER_RESTART is safe). Use cfs_b->lock to make it safe.

Signed-off-by: Ben Segall <bsegall@google.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: pjt@google.com
Link: http://lkml.kernel.org/r/20131016181617.22647.73829.stgit@sword-of-the-dawn.mtv.corp.google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Chris J Arges <chris.j.arges@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
sched: Fix race on toggling cfs_bandwidth_used

commit 1ee14e6c8cddeeb8a490d7b54cd9016e4bb900b4 upstream.

When we transition cfs_bandwidth_used to false, any currently
throttled groups will incorrectly return false from cfs_rq_throttled.
While tg_set_cfs_bandwidth will unthrottle them eventually, currently
running code (including at least dequeue_task_fair and
distribute_cfs_runtime) will cause errors.

Fix this by turning off cfs_bandwidth_used only after unthrottling all
cfs_rqs.

Tested: toggle bandwidth back and forth on a loaded cgroup. Caused
crashes in minutes without the patch, hasn't crashed with it.

Signed-off-by: Ben Segall <bsegall@google.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: pjt@google.com
Link: http://lkml.kernel.org/r/20131016181611.22647.80365.stgit@sword-of-the-dawn.mtv.corp.google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Chris J Arges <chris.j.arges@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
x86, fpu, amd: Clear exceptions in AMD FXSAVE workaround

commit 26bef1318adc1b3a530ecc807ef99346db2aa8b0 upstream.

Before we do an EMMS in the AMD FXSAVE information leak workaround we
need to clear any pending exceptions, otherwise we trap with a
floating-point exception inside this code.

Reported-by: halfdog <me@halfdog.net>
Tested-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/CA%2B55aFxQnY_PCG_n4=0w-VG=YLXL-yr7oMxyy0WU2gCBAf3ydg@mail.gmail.com
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ARM: shmobile: mackerel: Fix coherent DMA mask

commit b6328a6b7ba57fc84c38248f6f0e387e1170f1a8 upstream.

Commit 4dcfa60071b3d23f0181f27d8519f12e37cefbb9 ("ARM: DMA-API: better
handing of DMA masks for coherent allocations") added an additional
check to the coherent DMA mask that results in an error when the mask is
larger than what dma_addr_t can address.

Set the LCDC coherent DMA mask to DMA_BIT_MASK(32) instead of ~0 to fix
the problem.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ARM: fix "bad mode in ... handler" message for undefined instructions

commit 29c350bf28da333e41e30497b649fe335712a2ab upstream.

The array was missing the final entry for the undefined instruction
exception handler; this commit adds it.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Conflicts:
	arch/arm/kernel/traps.c
bridge: use spin_lock_bh() in br_multicast_set_hash_max

[ Upstream commit fe0d692bbc645786bce1a98439e548ae619269f5 ]

br_multicast_set_hash_max() is called from process context in
net/bridge/br_sysfs_br.c by the sysfs store_hash_max() function.

br_multicast_set_hash_max() calls spin_lock(&br->multicast_lock),
which can deadlock the CPU if a softirq that also tries to take the
same lock interrupts br_multicast_set_hash_max() while the lock is
held .  This can happen quite easily when any of the bridge multicast
timers expire, which try to take the same lock.

The fix here is to use spin_lock_bh(), preventing other softirqs from
executing on this CPU.

Steps to reproduce:

1. Create a bridge with several interfaces (I used 4).
2. Set the "multicast query interval" to a low number, like 2.
3. Enable the bridge as a multicast querier.
4. Repeatedly set the bridge hash_max parameter via sysfs.

  # brctl addbr br0
  # brctl addif br0 eth1 eth2 eth3 eth4
  # brctl setmcqi br0 2
  # brctl setmcquerier br0 1

  # while true ; do echo 4096 > /sys/class/net/br0/bridge/hash_max; done

Signed-off-by: Curt Brune <curt@cumulusnetworks.com>
Signed-off-by: Scott Feldman <sfeldma@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net: llc: fix use after free in llc_ui_recvmsg

[ Upstream commit 4d231b76eef6c4a6bd9c96769e191517765942cb ]

While commit 30a584d944fb fixes datagram interface in LLC, a use
after free bug has been introduced for SOCK_STREAM sockets that do
not make use of MSG_PEEK.

The flow is as follow ...

  if (!(flags & MSG_PEEK)) {
    ...
    sk_eat_skb(sk, skb, false);
    ...
  }
  ...
  if (used + offset < skb->len)
    continue;

... where sk_eat_skb() calls __kfree_skb(). Therefore, cache
original length and work on skb_len to check partial reads.

Fixes: 30a584d944fb ("[LLX]: SOCK_DGRAM interface fixes")
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
vlan: Fix header ops passthru when doing TX VLAN offload.

[ Upstream commit 2205369a314e12fcec4781cc73ac9c08fc2b47de ]

When the vlan code detects that the real device can do TX VLAN offloads
in hardware, it tries to arrange for the real device's header_ops to
be invoked directly.

But it does so illegally, by simply hooking the real device's
header_ops up to the VLAN device.

This doesn't work because we will end up invoking a set of header_ops
routines which expect a device type which matches the real device, but
will see a VLAN device instead.

Fix this by providing a pass-thru set of header_ops which will arrange
to pass the proper real device instead.

To facilitate this add a dev_rebuild_header().  There are
implementations which provide a ->cache and ->create but not a
->rebuild (f.e. PLIP).  So we need a helper function just like
dev_hard_header() to avoid crashes.

Use this helper in the one existing place where the
header_ops->rebuild was being invoked, the neighbour code.

With lots of help from Florian Westphal.

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net: rose: restore old recvmsg behavior
rds: prevent dereference of a NULL device

[ Upstream commit c2349758acf1874e4c2b93fe41d072336f1a31d0 ]

Binding might result in a NULL device, which is dereferenced
causing this BUG:

[ 1317.260548] BUG: unable to handle kernel NULL pointer dereference at 000000000000097
4
[ 1317.261847] IP: [<ffffffff84225f52>] rds_ib_laddr_check+0x82/0x110
[ 1317.263315] PGD 418bcb067 PUD 3ceb21067 PMD 0
[ 1317.263502] Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
[ 1317.264179] Dumping ftrace buffer:
[ 1317.264774]    (ftrace buffer empty)
[ 1317.265220] Modules linked in:
[ 1317.265824] CPU: 4 PID: 836 Comm: trinity-child46 Tainted: G        W    3.13.0-rc4-
next-20131218-sasha-00013-g2cebb9b-dirty #4159
[ 1317.267415] task: ffff8803ddf33000 ti: ffff8803cd31a000 task.ti: ffff8803cd31a000
[ 1317.268399] RIP: 0010:[<ffffffff84225f52>]  [<ffffffff84225f52>] rds_ib_laddr_check+
0x82/0x110
[ 1317.269670] RSP: 0000:ffff8803cd31bdf8  EFLAGS: 00010246
[ 1317.270230] RAX: 0000000000000000 RBX: ffff88020b0dd388 RCX: 0000000000000000
[ 1317.270230] RDX: ffffffff8439822e RSI: 00000000000c000a RDI: 0000000000000286
[ 1317.270230] RBP: ffff8803cd31be38 R08: 0000000000000000 R09: 0000000000000000
[ 1317.270230] R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000
[ 1317.270230] R13: 0000000054086700 R14: 0000000000a25de0 R15: 0000000000000031
[ 1317.270230] FS:  00007ff40251d700(0000) GS:ffff88022e200000(0000) knlGS:000000000000
0000
[ 1317.270230] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[ 1317.270230] CR2: 0000000000000974 CR3: 00000003cd478000 CR4: 00000000000006e0
[ 1317.270230] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 1317.270230] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000090602
[ 1317.270230] Stack:
[ 1317.270230]  0000000054086700 5408670000a25de0 5408670000000002 0000000000000000
[ 1317.270230]  ffffffff84223542 00000000ea54c767 0000000000000000 ffffffff86d26160
[ 1317.270230]  ffff8803cd31be68 ffffffff84223556 ffff8803cd31beb8 ffff8800c6765280
[ 1317.270230] Call Trace:
[ 1317.270230]  [<ffffffff84223542>] ? rds_trans_get_preferred+0x42/0xa0
[ 1317.270230]  [<ffffffff84223556>] rds_trans_get_preferred+0x56/0xa0
[ 1317.270230]  [<ffffffff8421c9c3>] rds_bind+0x73/0xf0
[ 1317.270230]  [<ffffffff83e4ce62>] SYSC_bind+0x92/0xf0
[ 1317.270230]  [<ffffffff812493f8>] ? context_tracking_user_exit+0xb8/0x1d0
[ 1317.270230]  [<ffffffff8119313d>] ? trace_hardirqs_on+0xd/0x10
[ 1317.270230]  [<ffffffff8107a852>] ? syscall_trace_enter+0x32/0x290
[ 1317.270230]  [<ffffffff83e4cece>] SyS_bind+0xe/0x10
[ 1317.270230]  [<ffffffff843a6ad0>] tracesys+0xdd/0xe2
[ 1317.270230] Code: 00 8b 45 cc 48 8d 75 d0 48 c7 45 d8 00 00 00 00 66 c7 45 d0 02 00
89 45 d4 48 89 df e8 78 49 76 ff 41 89 c4 85 c0 75 0c 48 8b 03 <80> b8 74 09 00 00 01 7
4 06 41 bc 9d ff ff ff f6 05 2a b6 c2 02
[ 1317.270230] RIP  [<ffffffff84225f52>] rds_ib_laddr_check+0x82/0x110
[ 1317.270230]  RSP <ffff8803cd31bdf8>
[ 1317.270230] CR2: 0000000000000974

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>
hamradio/yam: fix info leak in ioctl

[ Upstream commit 8e3fbf870481eb53b2d3a322d1fc395ad8b367ed ]

The yam_ioctl() code fails to initialise the cmd field
of the struct yamdrv_ioctl_cfg. Add an explicit memset(0)
before filling the structure to avoid the 4-byte info leak.

Signed-off-by: Salva Peiró <speiro@ai2.upv.es>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/net/hamradio: Integer overflow in hdlcdrv_ioctl()

[ Upstream commit e9db5c21d3646a6454fcd04938dd215ac3ab620a ]

The local variable 'bi' comes from userspace. If userspace passed a
large number to 'bi.data.calibrate', there would be an integer overflow
in the following line:
	s->hdlctx.calibrate = bi.data.calibrate * s->par.bitrate / 16;

Signed-off-by: Wenliang Fan <fanwlexca@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net: inet_diag: zero out uninitialized idiag_{src,dst} fields

[ Upstream commit b1aac815c0891fe4a55a6b0b715910142227700f ]

Jakub reported while working with nlmon netlink sniffer that parts of
the inet_diag_sockid are not initialized when r->idiag_family != AF_INET6.
That is, fields of r->id.idiag_src[1 ... 3], r->id.idiag_dst[1 ... 3].

In fact, it seems that we can leak 6 * sizeof(u32) byte of kernel [slab]
memory through this. At least, in udp_dump_one(), we allocate a skb in ...

  rep = nlmsg_new(sizeof(struct inet_diag_msg) + ..., GFP_KERNEL);

... and then pass that to inet_sk_diag_fill() that puts the whole struct
inet_diag_msg into the skb, where we only fill out r->id.idiag_src[0],
r->id.idiag_dst[0] and leave the rest untouched:

  r->id.idiag_src[0] = inet->inet_rcv_saddr;
  r->id.idiag_dst[0] = inet->inet_daddr;

struct inet_diag_msg embeds struct inet_diag_sockid that is correctly /
fully filled out in IPv6 case, but for IPv4 not.

So just zero them out by using plain memset (for this little amount of
bytes it's probably not worth the extra check for idiag_family == AF_INET).

Similarly, fix also other places where we fill that out.

Reported-by: Jakub Zawadzki <darkjames-ws@darkjames.pl>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net: unix: allow bind to fail on mutex lock

[ Upstream commit 37ab4fa7844a044dc21fde45e2a0fc2f3c3b6490 ]

This is similar to the set_peek_off patch where calling bind while the
socket is stuck in unix_dgram_recvmsg() will block and cause a hung task
spew after a while.

This is also the last place that did a straightforward mutex_lock(), so
there shouldn't be any more of these patches.

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>
netvsc: don't flush peers notifying work during setting mtu

[ Upstream commit 50dc875f2e6e2e04aed3b3033eb0ac99192d6d02 ]

There's a possible deadlock if we flush the peers notifying work during setting
mtu:

[   22.991149] ======================================================
[   22.991173] [ INFO: possible circular locking dependency detected ]
[   22.991198] 3.10.0-54.0.1.el7.x86_64.debug #1 Not tainted
[   22.991219] -------------------------------------------------------
[   22.991243] ip/974 is trying to acquire lock:
[   22.991261]  ((&(&net_device_ctx->dwork)->work)){+.+.+.}, at: [<ffffffff8108af95>] flush_work+0x5/0x2e0
[   22.991307]
but task is already holding lock:
[   22.991330]  (rtnl_mutex){+.+.+.}, at: [<ffffffff81539deb>] rtnetlink_rcv+0x1b/0x40
[   22.991367]
which lock already depends on the new lock.

[   22.991398]
the existing dependency chain (in reverse order) is:
[   22.991426]
-> #1 (rtnl_mutex){+.+.+.}:
[   22.991449]        [<ffffffff810dfdd9>] __lock_acquire+0xb19/0x1260
[   22.991477]        [<ffffffff810e0d12>] lock_acquire+0xa2/0x1f0
[   22.991501]        [<ffffffff81673659>] mutex_lock_nested+0x89/0x4f0
[   22.991529]        [<ffffffff815392b7>] rtnl_lock+0x17/0x20
[   22.991552]        [<ffffffff815230b2>] netdev_notify_peers+0x12/0x30
[   22.991579]        [<ffffffffa0340212>] netvsc_send_garp+0x22/0x30 [hv_netvsc]
[   22.991610]        [<ffffffff8108d251>] process_one_work+0x211/0x6e0
[   22.991637]        [<ffffffff8108d83b>] worker_thread+0x11b/0x3a0
[   22.991663]        [<ffffffff81095e5d>] kthread+0xed/0x100
[   22.991686]        [<ffffffff81681c6c>] ret_from_fork+0x7c/0xb0
[   22.991715]
-> #0 ((&(&net_device_ctx->dwork)->work)){+.+.+.}:
[   22.991715]        [<ffffffff810de817>] check_prevs_add+0x967/0x970
[   22.991715]        [<ffffffff810dfdd9>] __lock_acquire+0xb19/0x1260
[   22.991715]        [<ffffffff810e0d12>] lock_acquire+0xa2/0x1f0
[   22.991715]        [<ffffffff8108afde>] flush_work+0x4e/0x2e0
[   22.991715]        [<ffffffff8108e1b5>] __cancel_work_timer+0x95/0x130
[   22.991715]        [<ffffffff8108e303>] cancel_delayed_work_sync+0x13/0x20
[   22.991715]        [<ffffffffa03404e4>] netvsc_change_mtu+0x84/0x200 [hv_netvsc]
[   22.991715]        [<ffffffff815233d4>] dev_set_mtu+0x34/0x80
[   22.991715]        [<ffffffff8153bc2a>] do_setlink+0x23a/0xa00
[   22.991715]        [<ffffffff8153d054>] rtnl_newlink+0x394/0x5e0
[   22.991715]        [<ffffffff81539eac>] rtnetlink_rcv_msg+0x9c/0x260
[   22.991715]        [<ffffffff8155cdd9>] netlink_rcv_skb+0xa9/0xc0
[   22.991715]        [<ffffffff81539dfa>] rtnetlink_rcv+0x2a/0x40
[   22.991715]        [<ffffffff8155c41d>] netlink_unicast+0xdd/0x190
[   22.991715]        [<ffffffff8155c807>] netlink_sendmsg+0x337/0x750
[   22.991715]        [<ffffffff8150d219>] sock_sendmsg+0x99/0xd0
[   22.991715]        [<ffffffff8150d63e>] ___sys_sendmsg+0x39e/0x3b0
[   22.991715]        [<ffffffff8150eba2>] __sys_sendmsg+0x42/0x80
[   22.991715]        [<ffffffff8150ebf2>] SyS_sendmsg+0x12/0x20
[   22.991715]        [<ffffffff81681d19>] system_call_fastpath+0x16/0x1b

This is because we hold the rtnl_lock() before ndo_change_mtu() and try to flush
the work in netvsc_change_mtu(), in the mean time, netdev_notify_peers() may be
called from worker and also trying to hold the rtnl_lock. This will lead the
flush won't succeed forever. Solve this by not canceling and flushing the work,
this is safe because the transmission done by NETDEV_NOTIFY_PEERS was
synchronized with the netif_tx_disable() called by netvsc_change_mtu().

Reported-by: Yaju Cao <yacao@redhat.com>
Tested-by: Yaju Cao <yacao@redhat.com>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Acked-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tg3: Initialize REG_BASE_ADDR at PCI config offset 120 to 0

[ Upstream commit 388d3335575f4c056dcf7138a30f1454e2145cd8 ]

The new tg3 driver leaves REG_BASE_ADDR (PCI config offset 120)
uninitialized. From power on reset this register may have garbage in it. The
Register Base Address register defines the device local address of a
register. The data pointed to by this location is read or written using
the Register Data register (PCI config offset 128). When REG_BASE_ADDR has
garbage any read or write of Register Data Register (PCI 128) will cause the
PCI bus to lock up. The TCO watchdog will fire and bring down the system.

Signed-off-by: Nat Gurumoorthy <natg@google.com>
Acked-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>