linux-stable.git/include, branch v3.15.7

net: fix sparse warning in sk_dst_set()

2014-07-28T15:08:23+00:00

[ Upstream commit 5925a0555bdaf0b396a84318cbc21ba085f6c0d3 ]

sk_dst_cache has __rcu annotation, so we need a cast to avoid
following sparse error :

include/net/sock.h:1774:19: warning: incorrect type in initializer (different address spaces)
include/net/sock.h:1774:19:    expected struct dst_entry [noderef] *__ret
include/net/sock.h:1774:19:    got struct dst_entry *dst

Signed-off-by: Eric Dumazet 
Reported-by: kbuild test robot 
Fixes: 7f502361531e ("ipv4: irq safe sk_dst_[re]set() and ipv4_sk_update_pmtu() fix")
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

ipv4: irq safe sk_dst_[re]set() and ipv4_sk_update_pmtu() fix

2014-07-28T15:08:23+00:00

[ Upstream commit 7f502361531e9eecb396cf99bdc9e9a59f7ebd7f ]

We have two different ways to handle changes to sk->sk_dst

First way (used by TCP) assumes socket lock is owned by caller, and use
no extra lock : __sk_dst_set() & __sk_dst_reset()

Another way (used by UDP) uses sk_dst_lock because socket lock is not
always taken. Note that sk_dst_lock is not softirq safe.

These ways are not inter changeable for a given socket type.

ipv4_sk_update_pmtu(), added in linux-3.8, added a race, as it used
the socket lock as synchronization, but users might be UDP sockets.

Instead of converting sk_dst_lock to a softirq safe version, use xchg()
as we did for sk_rx_dst in commit e47eb5dfb296b ("udp: ipv4: do not use
sk_dst_lock from softirq context")

In a follow up patch, we probably can remove sk_dst_lock, as it is
only used in IPv6.

Signed-off-by: Eric Dumazet 
Cc: Steffen Klassert 
Fixes: 9cb3a50c5f63e ("ipv4: Invalidate the socket cached route on pmtu events if possible")
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

ipv4: fix dst race in sk_dst_get()

2014-07-28T15:08:23+00:00

[ Upstream commit f88649721268999bdff09777847080a52004f691 ]

When IP route cache had been removed in linux-3.6, we broke assumption
that dst entries were all freed after rcu grace period. DST_NOCACHE
dst were supposed to be freed from dst_release(). But it appears
we want to keep such dst around, either in UDP sockets or tunnels.

In sk_dst_get() we need to make sure dst refcount is not 0
before incrementing it, or else we might end up freeing a dst
twice.

DST_NOCACHE set on a dst does not mean this dst can not be attached
to a socket or a tunnel.

Then, before actual freeing, we need to observe a rcu grace period
to make sure all other cpus can catch the fact the dst is no longer
usable.

Signed-off-by: Eric Dumazet 
Reported-by: Dormando 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

kernfs: introduce kernfs_pin_sb()

2014-07-17T23:23:19+00:00

commit 4e26445faad366d67d7723622bf6a60a6f0f5993 upstream.

kernfs_pin_sb() tries to get a refcnt of the superblock.

This will be used by cgroupfs.

v2:
- make kernfs_pin_sb() return the superblock.
- drop kernfs_drop_sb().

tj: Updated the comment a bit.

[ This is a prerequisite for a bugfix. ]
Acked-by: Greg Kroah-Hartman 
Signed-off-by: Li Zefan 
Signed-off-by: Tejun Heo 
Signed-off-by: Greg Kroah-Hartman

kernfs: implement kernfs_root->supers list

2014-07-17T23:23:19+00:00

commit 7d568a8383bbb9c1f5167781075906acb2bb1550 upstream.

Currently, there's no way to find out which super_blocks are
associated with a given kernfs_root.  Let's implement it - the planned
inotify extension to kernfs_notify() needs it.

Make kernfs_super_info point back to the super_block and chain it at
kernfs_root->supers.

Signed-off-by: Tejun Heo 
[lizf: Backported to 3.15: Adjust context]
Signed-off-by: Li Zefan 
Signed-off-by: Greg Kroah-Hartman

ring-buffer: Check if buffer exists before polling

2014-07-17T23:23:18+00:00

commit 8b8b36834d0fff67fc8668093f4312dd04dcf21d upstream.

The per_cpu buffers are created one per possible CPU. But these do
not mean that those CPUs are online, nor do they even exist.

With the addition of the ring buffer polling, it assumes that the
caller polls on an existing buffer. But this is not the case if
the user reads trace_pipe from a CPU that does not exist, and this
causes the kernel to crash.

Simple fix is to check the cpu against buffer bitmask against to see
if the buffer was allocated or not and return -ENODEV if it is
not.

More updates were done to pass the -ENODEV back up to userspace.

Link: http://lkml.kernel.org/r/5393DB61.6060707@oracle.com

Reported-by: Sasha Levin 
Signed-off-by: Steven Rostedt 
Signed-off-by: Greg Kroah-Hartman

drm/i915: provide interface for audio driver to query cdclk

2014-07-09T18:21:26+00:00

commit c149dcb5c60bfea8871f16dfcc0690255eeb825f upstream.

For Haswell and Broadwell, if the display power well has been disabled,
the display audio controller divider values EM4 M VALUE and EM5 N VALUE
will have been lost. The CDCLK frequency is required for reprogramming them
to generate 24MHz HD-A link BCLK. So provide a private interface for the
audio driver to query CDCLK.

This is a stopgap solution until a more generic interface between audio
and display drivers has been implemented.

Signed-off-by: Jani Nikula 
Reviewed-by: Damien Lespiau 
Signed-off-by: Mengdong Lin 
Signed-off-by: Takashi Iwai 
Signed-off-by: Greg Kroah-Hartman

drm/i915, HD-audio: Don't continue probing when nomodeset is given

2014-07-09T18:21:26+00:00

commit 74b0c2d75fb4cc89173944e6d8f9eb47aca0c343 upstream.

When a machine is booted with nomodeset option, i915 driver skips the
whole initialization.  Meanwhile, HD-audio tries to bind wth i915 just
by request_symbol() without knowing that the initialization was
skipped, and eventually it hits WARN_ON() in i915_request_power_well()
and i915_release_power_well() wrongly but still continues probing,
even though it doesn't work at all.

In this patch, both functions are changed to return an error in case
of uninitialized state instead of WARN_ON(), so that HD-audio driver
can give up HDMI controller initialization at the right time.

Acked-by: Daniel Vetter 
Signed-off-by: Takashi Iwai 
Signed-off-by: Greg Kroah-Hartman

usb: gadget: f_fs: resurect usb_functionfs_descs_head structure

2014-07-09T18:21:24+00:00

commit 09122141785348bf9539762a5f5dbbae3761c783 upstream.

Even though usb_functionfs_descs_head structure is now deprecated,
it has been used by some user space tools.  Its removel in commit
[ac8dde1: “Add flags to descriptors block”] was an oversight
leading to build breakage for such tools.

Bring it back so that old user space tools can still be build
without problems on newer kernel versions.

Reported-by: Lad, Prabhakar 
Reported-by: Krzysztof Opasiak 
Signed-off-by: Michal Nazarewicz 
Signed-off-by: Felipe Balbi 
Signed-off-by: Greg Kroah-Hartman

usb-storage/SCSI: Add broken_fua blacklist flag

2014-07-09T18:21:23+00:00

commit b14bf2d0c0358140041d1c1805a674376964d0e0 upstream.

Some buggy JMicron USB-ATA bridges don't know how to translate the FUA
bit in READs or WRITEs.  This patch adds an entry in unusual_devs.h
and a blacklist flag to tell the sd driver not to use FUA.

Signed-off-by: Alan Stern 
Reported-by: Michael Büsch 
Tested-by: Michael Büsch 
Acked-by: James Bottomley 
CC: Matthew Dharm 
Signed-off-by: Greg Kroah-Hartman