This patch removes the global variable composite in composite.c.
The private data which was saved there is now passed via an additional
argument to the bind() function in struct usb_gadget_driver.

Only the "old-style" UDC drivers have to be touched here, new style are
doing it right because this change is made in udc-core.
Acked-by: NMichal Nazarewicz <mina86@mina86.com>
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

This partly reverts 07a18bd7 ("usb gadget: don't save bind callback in
struct usb_composite_driver") and fixes new drivers. The section missmatch
problems was solved by whitelisting bind callback in modpost.
Acked-by: NMichal Nazarewicz <mina86@mina86.com>
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

This partly reverts 07a18bd7 ("usb gadget: don't save bind callback in
struct usb_composite_driver") and fixes new drivers. The section missmatch
problems was solved by whitelisting structs in question via __ref.

Cc: devel@driverdev.osuosl.org
Acked-by: NMichal Nazarewicz <mina86@mina86.com>
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

It was moved to be an argument in 07a18bd7 ("usb gadget: don't
save bind callback in struct usb_composite_driver"). The reason was to
avoid the section missmatch. The warning was shown because ->bind is
marked as __init becuase it is a one time init. The warning can be also
suppresed by whitelisting the variable i.e. rename it to lets say _probe.
Acked-by: NMichal Nazarewicz <mina86@mina86.com>
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

This commit removes USB_GADGET_DUALSPEED and USB_GADGET_SUPERSPEED
Kconfig options.  Since now kernel allows many UDC drivers to be
compiled, those options may turn to no longer be valid.  For
instance, if someone decides to build UDC that supports super
speed and UDC that supports high speed only, the latter will be
"assumed" to support super speed since USB_GADGET_SUPERSPEED will
be selected by the former.

The test of whether CONFIG_USB_GADGET_*SPEED was defined was just
an optimisation which removed otherwise dead code (ie. if UDC is
not dual speed, there is no need to handle cases that can happen
if speed is high).  This commit removes those checks.
Signed-off-by: NMichal Nazarewicz <mina86@mina86.com>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

Returns a snapshot of the GPU clock counter.  Needed
for certain OpenGL extensions.

v2: agd5f
- address Jerome's comments
- add function documentation
Signed-off-by: NMarek Olšák <maraeo@gmail.com>
Reviewed-by: NJerome Glisse <jglisse@redhat.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

One condition before codel_Newton_step() was not good if
we never left the dropping state for a flow. As a result
rec_inv_sqrt was 0, instead of the ~0 initial value.

codel control law was then set to a very aggressive mode, dropping
many packets before reaching 'target' and recovering from this problem.

To keep codel_vars_init() as efficient as possible, refine
the condition to make sure rec_inv_sqrt initial value is correct

Many thanks to Anton Mich for discovering the issue and suggesting
a fix.
Reported-by: NAnton Mich <lp2s1h@gmail.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

ip_send_skb() can send orphaned skb, so we must pass the net pointer to
avoid possible NULL dereference in error path.

Bug added by commit 3a7c384f (ipv4: tcp: unicast_sock should not
land outside of TCP stack)
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The higher ptrace restriction levels should be blocking even
PTRACE_TRACEME requests. The comments in the LSM documentation are
misleading about when the checks happen (the parent does not go through
security_ptrace_access_check() on a PTRACE_TRACEME call).
Signed-off-by: NKees Cook <keescook@chromium.org>
Cc: stable@vger.kernel.org # 3.5.x and later
Signed-off-by: NJames Morris <james.l.morris@oracle.com>

commit 5d299f3d (net: ipv6: fix TCP early demux) added a
regression for ipv6_mapped case.

[   67.422369] SELinux: initialized (dev autofs, type autofs), uses
genfs_contexts
[   67.449678] SELinux: initialized (dev autofs, type autofs), uses
genfs_contexts
[   92.631060] BUG: unable to handle kernel NULL pointer dereference at
(null)
[   92.631435] IP: [<          (null)>]           (null)
[   92.631645] PGD 0
[   92.631846] Oops: 0010 [#1] SMP
[   92.632095] Modules linked in: autofs4 sunrpc ipv6 dm_mirror
dm_region_hash dm_log dm_multipath dm_mod video sbs sbshc battery ac lp
parport sg snd_hda_intel snd_hda_codec snd_seq_oss snd_seq_midi_event
snd_seq snd_seq_device pcspkr snd_pcm_oss snd_mixer_oss snd_pcm
snd_timer serio_raw button floppy snd i2c_i801 i2c_core soundcore
snd_page_alloc shpchp ide_cd_mod cdrom microcode ehci_hcd ohci_hcd
uhci_hcd
[   92.634294] CPU 0
[   92.634294] Pid: 4469, comm: sendmail Not tainted 3.6.0-rc1 #3
[   92.634294] RIP: 0010:[<0000000000000000>]  [<          (null)>]
(null)
[   92.634294] RSP: 0018:ffff880245fc7cb0  EFLAGS: 00010282
[   92.634294] RAX: ffffffffa01985f0 RBX: ffff88024827ad00 RCX:
0000000000000000
[   92.634294] RDX: 0000000000000218 RSI: ffff880254735380 RDI:
ffff88024827ad00
[   92.634294] RBP: ffff880245fc7cc8 R08: 0000000000000001 R09:
0000000000000000
[   92.634294] R10: 0000000000000000 R11: ffff880245fc7bf8 R12:
ffff880254735380
[   92.634294] R13: ffff880254735380 R14: 0000000000000000 R15:
7fffffffffff0218
[   92.634294] FS:  00007f4516ccd6f0(0000) GS:ffff880256600000(0000)
knlGS:0000000000000000
[   92.634294] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[   92.634294] CR2: 0000000000000000 CR3: 0000000245ed1000 CR4:
00000000000007f0
[   92.634294] DR0: 0000000000000000 DR1: 0000000000000000 DR2:
0000000000000000
[   92.634294] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7:
0000000000000400
[   92.634294] Process sendmail (pid: 4469, threadinfo ffff880245fc6000,
task ffff880254b8cac0)
[   92.634294] Stack:
[   92.634294]  ffffffff813837a7 ffff88024827ad00 ffff880254b6b0e8
ffff880245fc7d68
[   92.634294]  ffffffff81385083 00000000001d2680 ffff8802547353a8
ffff880245fc7d18
[   92.634294]  ffffffff8105903a ffff88024827ad60 0000000000000002
00000000000000ff
[   92.634294] Call Trace:
[   92.634294]  [<ffffffff813837a7>] ? tcp_finish_connect+0x2c/0xfa
[   92.634294]  [<ffffffff81385083>] tcp_rcv_state_process+0x2b6/0x9c6
[   92.634294]  [<ffffffff8105903a>] ? sched_clock_cpu+0xc3/0xd1
[   92.634294]  [<ffffffff81059073>] ? local_clock+0x2b/0x3c
[   92.634294]  [<ffffffff8138caf3>] tcp_v4_do_rcv+0x63a/0x670
[   92.634294]  [<ffffffff8133278e>] release_sock+0x128/0x1bd
[   92.634294]  [<ffffffff8139f060>] __inet_stream_connect+0x1b1/0x352
[   92.634294]  [<ffffffff813325f5>] ? lock_sock_nested+0x74/0x7f
[   92.634294]  [<ffffffff8104b333>] ? wake_up_bit+0x25/0x25
[   92.634294]  [<ffffffff813325f5>] ? lock_sock_nested+0x74/0x7f
[   92.634294]  [<ffffffff8139f223>] ? inet_stream_connect+0x22/0x4b
[   92.634294]  [<ffffffff8139f234>] inet_stream_connect+0x33/0x4b
[   92.634294]  [<ffffffff8132e8cf>] sys_connect+0x78/0x9e
[   92.634294]  [<ffffffff813fd407>] ? sysret_check+0x1b/0x56
[   92.634294]  [<ffffffff81088503>] ? __audit_syscall_entry+0x195/0x1c8
[   92.634294]  [<ffffffff811cc26e>] ? trace_hardirqs_on_thunk+0x3a/0x3f
[   92.634294]  [<ffffffff813fd3e2>] system_call_fastpath+0x16/0x1b
[   92.634294] Code:  Bad RIP value.
[   92.634294] RIP  [<          (null)>]           (null)
[   92.634294]  RSP <ffff880245fc7cb0>
[   92.634294] CR2: 0000000000000000
[   92.648982] ---[ end trace 24e2bed94314c8d9 ]---
[   92.649146] Kernel panic - not syncing: Fatal exception in interrupt

Fix this using inet_sk_rx_dst_set(), and export this function in case
IPv6 is modular.
Reported-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The EETI touchscreen asserts its IRQ line as soon as it has data in its
internal buffers. The line is automatically deasserted once all data has
been read via I2C. Hence, the driver has to monitor the GPIO line and
cannot simply rely on the interrupt handler reception.

In the current implementation of the driver, irq_to_gpio() is used to
determine the GPIO number from the i2c_client's IRQ value.

As irq_to_gpio() is not available on all platforms, this patch changes
this and makes the driver ignore the passed in IRQ. Instead, a GPIO is
added to the platform_data struct and gpio_to_irq is used to derive the
IRQ from that GPIO. If this fails, bail out. The driver is only able to
work in environments where the touchscreen GPIO can be mapped to an
IRQ.

Without this patch, building raumfeld_defconfig results in:

drivers/input/touchscreen/eeti_ts.c: In function 'eeti_ts_irq_active':
drivers/input/touchscreen/eeti_ts.c:65:2: error: implicit declaration of function 'irq_to_gpio' [-Werror=implicit-function-declaration]
Signed-off-by: NDaniel Mack <zonque@gmail.com>
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Cc: stable@vger.kernel.org (v3.2+)
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Sven Neumann <s.neumann@raumfeld.com>
Cc: linux-input@vger.kernel.org
Cc: Haojian Zhuang <haojian.zhuang@gmail.com>

The irq_to_gpio function was removed from the pxa platform
in linux-3.2, and this driver has been broken since.

There is actually no in-tree user of this driver that adds
this platform device, but the driver can and does get enabled
on some platforms.

Without this patch, building ezx_defconfig results in:

drivers/mfd/ezx-pcap.c: In function 'pcap_isr_work':
drivers/mfd/ezx-pcap.c:205:2: error: implicit declaration of function 'irq_to_gpio' [-Werror=implicit-function-declaration]
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NHaojian Zhuang <haojian.zhuang@gmail.com>
Cc: stable@vger.kernel.org (v3.2+)
Cc: Samuel Ortiz <sameo@linux.intel.com>
Cc: Daniel Ribeiro <drwyrm@gmail.com>

While investigating on network performance problems, I found this little
gem :

$ nm -v vmlinux | grep -1 dst_default_metrics
ffffffff82736540 b busy.46605
ffffffff82736560 B dst_default_metrics
ffffffff82736598 b dst_busy_list

Apparently, declaring a const array without initializer put it in
(writeable) bss section, in middle of possibly often dirtied cache
lines.

Since we really want dst_default_metrics be const to avoid any possible
false sharing and catch any buggy writes, I force a null initializer.

ffffffff818a4c20 R dst_default_metrics
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Revert commit 45226e94 (NMI watchdog: fix for lockup detector breakage
on resume) which breaks resume from system suspend on my SH7372
Mackerel board (by causing a NULL pointer dereference to happen) and
is generally wrong, because it abuses the CPU hotplug functionality
in a shamelessly blatant way.

The original issue should be addressed through appropriate syscore
resume callback instead.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>

The first idea of the CAN FD implementation started with a new struct
canfd_frame to be used for both CAN FD frames and legacy CAN frames.
The now mainlined implementation supports both CAN frame types simultaneously
and distinguishes them only by their required sizes: CAN_MTU and CANFD_MTU.

Only the struct canfd_frame contains a flags element which is needed for the
additional CAN FD information. As CAN FD implicitly means that the 'Extened
Data Length' mode is enabled the formerly defined CANFD_EDL bit became
redundant and also confusing as an unset bit would be an error and would
always need to be tested.

This patch removes the obsolete CANFD_EDL bit and clarifies the documentation
for the use of struct canfd_frame and the CAN FD relevant flags.
Signed-off-by: NOliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

IPv6 needs a cookie in dst_check() call.

We need to add rx_dst_cookie and provide a family independent
sk_rx_dst_set(sk, skb) method to properly support IPv6 TCP early demux.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The pdflush thread is long gone, so this patch removes references to pdflush
from vfs comments.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Finally we can kill the 'sync_supers' kernel thread along with the
'->write_super()' superblock operation because all the users are gone.
Now every file-system is supposed to self-manage own superblock and
its dirty state.

The nice thing about killing this thread is that it improves power management.
Indeed, 'sync_supers' is a source of monotonic system wake-ups - it woke up
every 5 seconds no matter what - even if there were no dirty superblocks and
even if there were no file-systems using this service (e.g., btrfs and
journalled ext4 do not need it). So it was wasting power most of the time. And
because the thread was in the core of the kernel, all systems had to have it.
So I am quite happy to make it go away.

Interestingly, this thread is a left-over from the pdflush kernel thread which
was a self-forking kernel thread responsible for all the write-back in old
Linux kernels. It was turned into per-block device BDI threads, and
'sync_supers' was a left-over. Thus, R.I.P, pdflush as well.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

The 'struct notifier_block' is not used in linux/iommu.h but
not declared anywhere. Add a forward declaration for it.
Reported-by: NThierry Reding <thierry.reding@avionic-design.de>
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>

The linux/iommu.h header uses types defined in linux/types.h but doesn't
include it.
Signed-off-by: NThierry Reding <thierry.reding@avionic-design.de>
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>

Otherwise you could run into:
WARN_ON in numa_register_memblks(), because node_possible_map is zero

References: https://bugzilla.novell.com/show_bug.cgi?id=757888

On this machine (ProLiant ML570 G3) the SRAT table contains:
  - No processor affinities
  - One memory affinity structure (which is set disabled)

CC: Per Jessen <per@opensuse.org>
CC: Andi Kleen <andi@firstfloor.org>
Signed-off-by: NThomas Renninger <trenn@suse.de>
Signed-off-by: NLen Brown <len.brown@intel.com>

Signed-off-by: NRafał Miłecki <zajec5@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Currently the only way for wireless drivers to tell whether or not OFDM
is allowed on the current channel is to check the regulatory
information. However, this requires hodling cfg80211_mutex, which is not
visible to the drivers.

Other regulatory restrictions are provided as flags in the channel
definition, so let's do similarly with OFDM. This patch adds a new flag,
IEEE80211_CHAN_NO_OFDM, to tell drivers that OFDM on a channel is not
allowed. This flag is set on any channels for which regulatory indicates
that OFDM is prohibited.
Signed-off-by: NSeth Forshee <seth.forshee@canonical.com>
Tested-by: NArend van Spriel <arend@broadcom.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

After SA is setup, one timer is armed to detect soft/hard expiration,
however the timer handler uses xtime to do the math. This makes hard
expiration occurs first before soft expiration after setting new date
with big interval. As a result new child SA is deleted before rekeying
the new one.
Signed-off-by: NFan Du <fdu@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Cache the device gso_max_segs in sock::sk_gso_max_segs and use it to
limit the size of TSO skbs.  This avoids the need to fall back to
software GSO for local TCP senders.
Signed-off-by: NBen Hutchings <bhutchings@solarflare.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

A peer (or local user) may cause TCP to use a nominal MSS of as little
as 88 (actual MSS of 76 with timestamps).  Given that we have a
sufficiently prodigious local sender and the peer ACKs quickly enough,
it is nevertheless possible to grow the window for such a connection
to the point that we will try to send just under 64K at once.  This
results in a single skb that expands to 861 segments.

In some drivers with TSO support, such an skb will require hundreds of
DMA descriptors; a substantial fraction of a TX ring or even more than
a full ring.  The TX queue selected for the skb may stall and trigger
the TX watchdog repeatedly (since the problem skb will be retried
after the TX reset).  This particularly affects sfc, for which the
issue is designated as CVE-2012-3412.

Therefore:
1. Add the field net_device::gso_max_segs holding the device-specific
   limit.
2. In netif_skb_features(), if the number of segments is too high then
   mask out GSO features to force fall back to software GSO.
Signed-off-by: NBen Hutchings <bhutchings@solarflare.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In commit 3b6e2723 ("locks: prevent side-effects of
locks_release_private before file_lock is initialized") we removed the
last user of lm_release_private without removing the field itself.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add a new operation code (BLKPG_RESIZE_PARTITION) to the BLKPG ioctl that
allows altering the size of an existing partition, even if it is currently
in use.

This patch converts hd_struct->nr_sects into sequence counter because
One might extend a partition while IO is happening to it and update of
nr_sects can be non-atomic on 32bit machines with 64bit sector_t. This
can lead to issues like reading inconsistent size of a partition. Sequence
counter have been used so that readers don't have to take bdev mutex lock
as we call sector_in_part() very frequently.

Now all the access to hd_struct->nr_sects should happen using sequence
counter read/update helper functions part_nr_sects_read/part_nr_sects_write.
There is one exception though, set_capacity()/get_capacity(). I think
theoritically race should exist there too but this patch does not
modify set_capacity()/get_capacity() due to sheer number of call sites
and I am afraid that change might break something. I have left that as a
TODO item. We can handle it later if need be. This patch does not introduce
any new races as such w.r.t set_capacity()/get_capacity().

v2: Add CONFIG_LBDAF test to UP preempt case as suggested by Phillip.
Signed-off-by: NVivek Goyal <vgoyal@redhat.com>
Signed-off-by: NPhillip Susi <psusi@ubuntu.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

The recent shdma driver split has mistakenly removed support for partial
DMA transfer size calculation on forced termination. This patch restores
it.
Signed-off-by: NGuennadi Liakhovetski <g.liakhovetski@gmx.de>
Acked-by: NVinod Koul <vinod.koul@linux.intel.com>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

The 1.75-based OLPC EC driver already does this; let's do it for all EC
drivers.  This gives us nice suspend/resume hooks, amongst other things.

We want to run the EC's suspend hooks later than other drivers (which may
be setting wakeup masks or be running EC commands).  We also want to run
the EC's resume hooks earlier than other drivers (which may want to run EC
commands).
Signed-off-by: NAndres Salomon <dilinger@queued.net>
Acked-by: NPaul Fox <pgf@laptop.org>
Reviewed-by: NThomas Gleixner <tglx@linutronix.de>

This provides a new API allows different OLPC architectures to override the
EC driver.  x86 and ARM OLPC machines use completely different EC backends.

The olpc_ec_cmd is synchronous, and waits for the workqueue to send the
command to the EC.  Multiple callers can run olpc_ec_cmd() at once, and
they will by serialized and sleep while only one executes on the EC at a time.

We don't provide an unregister function, as that doesn't make sense within
the context of OLPC machines - there's only ever 1 EC, it's critical to
functionality, and it certainly not hotpluggable.
Signed-off-by: NAndres Salomon <dilinger@queued.net>
Acked-by: NPaul Fox <pgf@laptop.org>
Reviewed-by: NThomas Gleixner <tglx@linutronix.de>

The OLPC EC driver has outgrown arch/x86/platform/.  It's time to both
share common code amongst different architectures, as well as move it out
of arch/x86/.  The XO-1.75 is ARM-based, and the EC driver shares a lot of
code with the x86 code.
Signed-off-by: NAndres Salomon <dilinger@queued.net>
Acked-by: NPaul Fox <pgf@laptop.org>
Reviewed-by: NThomas Gleixner <tglx@linutronix.de>

If a process creates a large hugetlbfs mapping that is eligible for page
table sharing and forks heavily with children some of whom fault and
others which destroy the mapping then it is possible for page tables to
get corrupted.  Some teardowns of the mapping encounter a "bad pmd" and
output a message to the kernel log.  The final teardown will trigger a
BUG_ON in mm/filemap.c.

This was reproduced in 3.4 but is known to have existed for a long time
and goes back at least as far as 2.6.37.  It was probably was introduced
in 2.6.20 by [39dde65c: shared page table for hugetlb page].  The messages
look like this;

[  ..........] Lots of bad pmd messages followed by this
[  127.164256] mm/memory.c:391: bad pmd ffff880412e04fe8(80000003de4000e7).
[  127.164257] mm/memory.c:391: bad pmd ffff880412e04ff0(80000003de6000e7).
[  127.164258] mm/memory.c:391: bad pmd ffff880412e04ff8(80000003de0000e7).
[  127.186778] ------------[ cut here ]------------
[  127.186781] kernel BUG at mm/filemap.c:134!
[  127.186782] invalid opcode: 0000 [#1] SMP
[  127.186783] CPU 7
[  127.186784] Modules linked in: af_packet cpufreq_conservative cpufreq_userspace cpufreq_powersave acpi_cpufreq mperf ext3 jbd dm_mod coretemp crc32c_intel usb_storage ghash_clmulni_intel aesni_intel i2c_i801 r8169 mii uas sr_mod cdrom sg iTCO_wdt iTCO_vendor_support shpchp serio_raw cryptd aes_x86_64 e1000e pci_hotplug dcdbas aes_generic container microcode ext4 mbcache jbd2 crc16 sd_mod crc_t10dif i915 drm_kms_helper drm i2c_algo_bit ehci_hcd ahci libahci usbcore rtc_cmos usb_common button i2c_core intel_agp video intel_gtt fan processor thermal thermal_sys hwmon ata_generic pata_atiixp libata scsi_mod
[  127.186801]
[  127.186802] Pid: 9017, comm: hugetlbfs-test Not tainted 3.4.0-autobuild #53 Dell Inc. OptiPlex 990/06D7TR
[  127.186804] RIP: 0010:[<ffffffff810ed6ce>]  [<ffffffff810ed6ce>] __delete_from_page_cache+0x15e/0x160
[  127.186809] RSP: 0000:ffff8804144b5c08  EFLAGS: 00010002
[  127.186810] RAX: 0000000000000001 RBX: ffffea000a5c9000 RCX: 00000000ffffffc0
[  127.186811] RDX: 0000000000000000 RSI: 0000000000000009 RDI: ffff88042dfdad00
[  127.186812] RBP: ffff8804144b5c18 R08: 0000000000000009 R09: 0000000000000003
[  127.186813] R10: 0000000000000000 R11: 000000000000002d R12: ffff880412ff83d8
[  127.186814] R13: ffff880412ff83d8 R14: 0000000000000000 R15: ffff880412ff83d8
[  127.186815] FS:  00007fe18ed2c700(0000) GS:ffff88042dce0000(0000) knlGS:0000000000000000
[  127.186816] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[  127.186817] CR2: 00007fe340000503 CR3: 0000000417a14000 CR4: 00000000000407e0
[  127.186818] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  127.186819] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[  127.186820] Process hugetlbfs-test (pid: 9017, threadinfo ffff8804144b4000, task ffff880417f803c0)
[  127.186821] Stack:
[  127.186822]  ffffea000a5c9000 0000000000000000 ffff8804144b5c48 ffffffff810ed83b
[  127.186824]  ffff8804144b5c48 000000000000138a 0000000000001387 ffff8804144b5c98
[  127.186825]  ffff8804144b5d48 ffffffff811bc925 ffff8804144b5cb8 0000000000000000
[  127.186827] Call Trace:
[  127.186829]  [<ffffffff810ed83b>] delete_from_page_cache+0x3b/0x80
[  127.186832]  [<ffffffff811bc925>] truncate_hugepages+0x115/0x220
[  127.186834]  [<ffffffff811bca43>] hugetlbfs_evict_inode+0x13/0x30
[  127.186837]  [<ffffffff811655c7>] evict+0xa7/0x1b0
[  127.186839]  [<ffffffff811657a3>] iput_final+0xd3/0x1f0
[  127.186840]  [<ffffffff811658f9>] iput+0x39/0x50
[  127.186842]  [<ffffffff81162708>] d_kill+0xf8/0x130
[  127.186843]  [<ffffffff81162812>] dput+0xd2/0x1a0
[  127.186845]  [<ffffffff8114e2d0>] __fput+0x170/0x230
[  127.186848]  [<ffffffff81236e0e>] ? rb_erase+0xce/0x150
[  127.186849]  [<ffffffff8114e3ad>] fput+0x1d/0x30
[  127.186851]  [<ffffffff81117db7>] remove_vma+0x37/0x80
[  127.186853]  [<ffffffff81119182>] do_munmap+0x2d2/0x360
[  127.186855]  [<ffffffff811cc639>] sys_shmdt+0xc9/0x170
[  127.186857]  [<ffffffff81410a39>] system_call_fastpath+0x16/0x1b
[  127.186858] Code: 0f 1f 44 00 00 48 8b 43 08 48 8b 00 48 8b 40 28 8b b0 40 03 00 00 85 f6 0f 88 df fe ff ff 48 89 df e8 e7 cb 05 00 e9 d2 fe ff ff <0f> 0b 55 83 e2 fd 48 89 e5 48 83 ec 30 48 89 5d d8 4c 89 65 e0
[  127.186868] RIP  [<ffffffff810ed6ce>] __delete_from_page_cache+0x15e/0x160
[  127.186870]  RSP <ffff8804144b5c08>
[  127.186871] ---[ end trace 7cbac5d1db69f426 ]---

The bug is a race and not always easy to reproduce.  To reproduce it I was
doing the following on a single socket I7-based machine with 16G of RAM.

$ hugeadm --pool-pages-max DEFAULT:13G
$ echo $((18*1048576*1024)) > /proc/sys/kernel/shmmax
$ echo $((18*1048576*1024)) > /proc/sys/kernel/shmall
$ for i in `seq 1 9000`; do ./hugetlbfs-test; done

On my particular machine, it usually triggers within 10 minutes but
enabling debug options can change the timing such that it never hits.
Once the bug is triggered, the machine is in trouble and needs to be
rebooted.  The machine will respond but processes accessing proc like "ps
aux" will hang due to the BUG_ON.  shutdown will also hang and needs a
hard reset or a sysrq-b.

The basic problem is a race between page table sharing and teardown.  For
the most part page table sharing depends on i_mmap_mutex.  In some cases,
it is also taking the mm->page_table_lock for the PTE updates but with
shared page tables, it is the i_mmap_mutex that is more important.

Unfortunately it appears to be also insufficient. Consider the following
situation

Process A					Process B
---------					---------
hugetlb_fault					shmdt
  						LockWrite(mmap_sem)
    						  do_munmap
						    unmap_region
						      unmap_vmas
						        unmap_single_vma
						          unmap_hugepage_range
      						            Lock(i_mmap_mutex)
							    Lock(mm->page_table_lock)
							    huge_pmd_unshare/unmap tables <--- (1)
							    Unlock(mm->page_table_lock)
      						            Unlock(i_mmap_mutex)
  huge_pte_alloc				      ...
    Lock(i_mmap_mutex)				      ...
    vma_prio_walk, find svma, spte		      ...
    Lock(mm->page_table_lock)			      ...
    share spte					      ...
    Unlock(mm->page_table_lock)			      ...
    Unlock(i_mmap_mutex)			      ...
  hugetlb_no_page									  <--- (2)
						      free_pgtables
						        unlink_file_vma
							hugetlb_free_pgd_range
						    remove_vma_list

In this scenario, it is possible for Process A to share page tables with
Process B that is trying to tear them down.  The i_mmap_mutex on its own
does not prevent Process A walking Process B's page tables.  At (1) above,
the page tables are not shared yet so it unmaps the PMDs.  Process A sets
up page table sharing and at (2) faults a new entry.  Process B then trips
up on it in free_pgtables.

This patch fixes the problem by adding a new function
__unmap_hugepage_range_final that is only called when the VMA is about to
be destroyed.  This function clears VM_MAYSHARE during
unmap_hugepage_range() under the i_mmap_mutex.  This makes the VMA
ineligible for sharing and avoids the race.  Superficially this looks like
it would then be vunerable to truncate and madvise issues but hugetlbfs
has its own truncate handlers so does not use unmap_mapping_range() and
does not support madvise(DONTNEED).

This should be treated as a -stable candidate if it is merged.

Test program is as follows. The test case was mostly written by Michal
Hocko with a few minor changes to reproduce this bug.

==== CUT HERE ====

static size_t huge_page_size = (2UL << 20);
static size_t nr_huge_page_A = 512;
static size_t nr_huge_page_B = 5632;

unsigned int get_random(unsigned int max)
{
	struct timeval tv;

	gettimeofday(&tv, NULL);
	srandom(tv.tv_usec);
	return random() % max;
}

static void play(void *addr, size_t size)
{
	unsigned char *start = addr,
		      *end = start + size,
		      *a;
	start += get_random(size/2);

	/* we could itterate on huge pages but let's give it more time. */
	for (a = start; a < end; a += 4096)
		*a = 0;
}

int main(int argc, char **argv)
{
	key_t key = IPC_PRIVATE;
	size_t sizeA = nr_huge_page_A * huge_page_size;
	size_t sizeB = nr_huge_page_B * huge_page_size;
	int shmidA, shmidB;
	void *addrA = NULL, *addrB = NULL;
	int nr_children = 300, n = 0;

	if ((shmidA = shmget(key, sizeA, IPC_CREAT|SHM_HUGETLB|0660)) == -1) {
		perror("shmget:");
		return 1;
	}

	if ((addrA = shmat(shmidA, addrA, SHM_R|SHM_W)) == (void *)-1UL) {
		perror("shmat");
		return 1;
	}
	if ((shmidB = shmget(key, sizeB, IPC_CREAT|SHM_HUGETLB|0660)) == -1) {
		perror("shmget:");
		return 1;
	}

	if ((addrB = shmat(shmidB, addrB, SHM_R|SHM_W)) == (void *)-1UL) {
		perror("shmat");
		return 1;
	}

fork_child:
	switch(fork()) {
		case 0:
			switch (n%3) {
			case 0:
				play(addrA, sizeA);
				break;
			case 1:
				play(addrB, sizeB);
				break;
			case 2:
				break;
			}
			break;
		case -1:
			perror("fork:");
			break;
		default:
			if (++n < nr_children)
				goto fork_child;
			play(addrA, sizeA);
			break;
	}
	shmdt(addrA);
	shmdt(addrB);
	do {
		wait(NULL);
	} while (--n > 0);
	shmctl(shmidA, IPC_RMID, NULL);
	shmctl(shmidB, IPC_RMID, NULL);
	return 0;
}

[akpm@linux-foundation.org: name the declaration's args, fix CONFIG_HUGETLBFS=n build]
Signed-off-by: NHugh Dickins <hughd@google.com>
Reviewed-by: NMichal Hocko <mhocko@suse.cz>
Signed-off-by: NMel Gorman <mgorman@suse.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

pg_data_t is zeroed before reaching free_area_init_core(), so remove the
now unnecessary initializations.
Signed-off-by: NMinchan Kim <minchan@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Compaction (and page migration in general) can currently be hindered
through pages being owned by memory cgroups that are at their limits and
unreclaimable.

The reason is that the replacement page is being charged against the limit
while the page being replaced is also still charged.  But this seems
unnecessary, given that only one of the two pages will still be in use
after migration finishes.

This patch changes the memcg migration sequence so that the replacement
page is not charged.  Whatever page is still in use after successful or
failed migration gets to keep the charge of the page that was going to be
replaced.

The replacement page will still show up temporarily in the rss/cache
statistics, this can be fixed in a later patch as it's less urgent.
Reported-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Acked-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: NMichal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Wanpeng Li <liwp.linux@gmail.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Implement the new swapfile a_ops for NFS and hook up ->direct_IO.  This
will set the NFS socket to SOCK_MEMALLOC and run socket reconnect under
PF_MEMALLOC as well as reset SOCK_MEMALLOC before engaging the protocol
->connect() method.

PF_MEMALLOC should allow the allocation of struct socket and related
objects and the early (re)setting of SOCK_MEMALLOC should allow us to
receive the packets required for the TCP connection buildup.

[jlayton@redhat.com: Restore PF_MEMALLOC task flags in all cases]
[dfeng@redhat.com: Fix handling of multiple swap files]
[a.p.zijlstra@chello.nl: Original patch]
Signed-off-by: NMel Gorman <mgorman@suse.de>
Acked-by: NRik van Riel <riel@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Eric B Munson <emunson@mgebm.net>
Cc: Eric Paris <eparis@redhat.com>
Cc: James Morris <jmorris@namei.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Mike Christie <michaelc@cs.wisc.edu>
Cc: Neil Brown <neilb@suse.de>
Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Xiaotian Feng <dfeng@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The patch "mm: add support for a filesystem to activate swap files and use
direct_IO for writing swap pages" added support for using direct_IO to
write swap pages but it is insufficient for highmem pages.

To support highmem pages, this patch kmaps() the page before calling the
direct_IO() handler.  As direct_IO deals with virtual addresses an
additional helper is necessary for get_kernel_pages() to lookup the struct
page for a kmap virtual address.
Signed-off-by: NMel Gorman <mgorman@suse.de>
Acked-by: NRik van Riel <riel@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Eric B Munson <emunson@mgebm.net>
Cc: Eric Paris <eparis@redhat.com>
Cc: James Morris <jmorris@namei.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Mike Christie <michaelc@cs.wisc.edu>
Cc: Neil Brown <neilb@suse.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Xiaotian Feng <dfeng@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The version of swap_activate introduced is sufficient for swap-over-NFS
but would not provide enough information to implement a generic handler.
This patch shuffles things slightly to ensure the same information is
available for aops->swap_activate() as is available to the core.

No functionality change.
Signed-off-by: NMel Gorman <mgorman@suse.de>
Acked-by: NRik van Riel <riel@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Eric B Munson <emunson@mgebm.net>
Cc: Eric Paris <eparis@redhat.com>
Cc: James Morris <jmorris@namei.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Mike Christie <michaelc@cs.wisc.edu>
Cc: Neil Brown <neilb@suse.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Xiaotian Feng <dfeng@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>