On large systems with a lot of memory, walking all RAM to determine page
types may take a half second or even more.

In non-blockable contexts, the page allocator will emit a page allocation
failure warning unless __GFP_NOWARN is specified.  In such contexts, irqs
are typically disabled and such a lengthy delay may even result in NMI
watchdog timeouts.

To fix this, suppress the page walk in such contexts when printing the
page allocation failure warning.
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

(cherry picked from commit 4b59e6c4)
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

This patch fixes the issues indicated by the test results that
ipmi_msg_handler() is invoked in atomic context.

BUG: scheduling while atomic: kipmi0/18933/0x10000100
Modules linked in: ipmi_si acpi_ipmi ...
CPU: 3 PID: 18933 Comm: kipmi0 Tainted: G       AW    3.10.0-rc7+ #2
Hardware name: QCI QSSC-S4R/QSSC-S4R, BIOS QSSC-S4R.QCI.01.00.0027.070120100606 07/01/2010
 ffff8838245eea00 ffff88103fc63c98 ffffffff814c4a1e ffff88103fc63ca8
 ffffffff814bfbab ffff88103fc63d28 ffffffff814c73e0 ffff88103933cbd4
 0000000000000096 ffff88103fc63ce8 ffff88102f618000 ffff881035c01fd8
Call Trace:
 <IRQ>  [<ffffffff814c4a1e>] dump_stack+0x19/0x1b
 [<ffffffff814bfbab>] __schedule_bug+0x46/0x54
 [<ffffffff814c73e0>] __schedule+0x83/0x59c
 [<ffffffff81058853>] __cond_resched+0x22/0x2d
 [<ffffffff814c794b>] _cond_resched+0x14/0x1d
 [<ffffffff814c6d82>] mutex_lock+0x11/0x32
 [<ffffffff8101e1e9>] ? __default_send_IPI_dest_field.constprop.0+0x53/0x58
 [<ffffffffa09e3f9c>] ipmi_msg_handler+0x23/0x166 [ipmi_si]
 [<ffffffff812bf6e4>] deliver_response+0x55/0x5a
 [<ffffffff812c0fd4>] handle_new_recv_msgs+0xb67/0xc65
 [<ffffffff81007ad1>] ? read_tsc+0x9/0x19
 [<ffffffff814c8620>] ? _raw_spin_lock_irq+0xa/0xc
 [<ffffffffa09e1128>] ipmi_thread+0x5c/0x146 [ipmi_si]
 ...

Also Tony Camuso says:

 We were getting occasional "Scheduling while atomic" call traces
 during boot on some systems. Problem was first seen on a Cisco C210
 but we were able to reproduce it on a Cisco c220m3. Setting
 CONFIG_LOCKDEP and LOCKDEP_SUPPORT to 'y' exposed a lockdep around
 tx_msg_lock in acpi_ipmi.c struct acpi_ipmi_device.

 =================================
 [ INFO: inconsistent lock state ]
 2.6.32-415.el6.x86_64-debug-splck #1
 ---------------------------------
 inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
 ksoftirqd/3/17 [HC0[0]:SC1[1]:HE1:SE0] takes:
  (&ipmi_device->tx_msg_lock){+.?...}, at: [<ffffffff81337a27>] ipmi_msg_handler+0x71/0x126
 {SOFTIRQ-ON-W} state was registered at:
   [<ffffffff810ba11c>] __lock_acquire+0x63c/0x1570
   [<ffffffff810bb0f4>] lock_acquire+0xa4/0x120
   [<ffffffff815581cc>] __mutex_lock_common+0x4c/0x400
   [<ffffffff815586ea>] mutex_lock_nested+0x4a/0x60
   [<ffffffff8133789d>] acpi_ipmi_space_handler+0x11b/0x234
   [<ffffffff81321c62>] acpi_ev_address_space_dispatch+0x170/0x1be

The fix implemented by this change has been tested by Tony:

 Tested the patch in a boot loop with lockdep debug enabled and never
 saw the problem in over 400 reboots.
Reported-and-tested-by: Tony Camuso <tcamuso@redhat.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Reviewed-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

(cherry picked from commit 06a8566b)
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

This reverts commit de77b795, which was
commit f6e80abe upstream.

This fix was only appropriate for Linux 3.7 onward, and introduced a
regression when applied to earlier versions.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
(cherry picked from commit 177c417c)

(cherry picked from commit HEAD)
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

Refuse RW mount of isofs filesystem. So far we just silently changed it
to RO mount but when the media is writeable, block layer won't notice
this change and thus will think device is used RW and will block eject
button of the drive. That is unexpected by users because for
non-writeable media eject button works just fine.

Userspace mount(8) command handles this just fine and retries mounting
with MS_RDONLY set so userspace shouldn't see any regression.  Plus any
tool mounting isofs is likely confronted with the case of read-only
media where block layer already refuses to mount the filesystem without
MS_RDONLY set so our behavior shouldn't be anything new for it.
Reported-by: Hui Wang <hui.wang@canonical.com>
Signed-off-by: Jan Kara <jack@suse.cz>

(cherry picked from commit 17b7f7cf)
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

Some devices of the "Speedlink VAD Cezanne" model need more aggressive fixing
than already done.

I made sure through testing that this patch would not interfere with the proper
working of a device that is bug-free. (The driver drops EV_REL events with
abs(val) >= 256, which are not achievable even on the highest laser resolution
hardware setting.)
Signed-off-by: Stefan Kriwanek <mail@stefankriwanek.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

(cherry picked from commit 06bb5219)
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

Need to check for /dev/zero.

Most likely more strings are missing too.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Link: http://lkml.kernel.org/r/1366848182-30449-1-git-send-email-andi@firstfloor.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

(cherry picked from commit 89365e6c)
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

If we pass fd of memory.usage_in_bytes of cgroup A to cgroup.event_control
of cgroup B, then we won't get memory usage notification from A but B!

What's worse, if A and B are in different mount hierarchy, we'll end up
accessing NULL pointer!

Disallow this kind of invalid usage.
Signed-off-by: Li Zefan <lizefan@huawei.com>
Acked-by: Kirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: Tejun Heo <tj@kernel.org>

(cherry picked from commit f169007b)
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

This bug fix is only for stable branches older than 3.10.  The bug was
fixed upstream by commit 2768935a ('sfc: reuse pages to avoid DMA
mapping/unmapping costs'), but that change is totally unsuitable for
stable.

Commit b590ace0 ('sfc: Fix efx_rx_buf_offset() in the presence of
swiotlb') added an explicit page_offset member to struct
efx_rx_buffer, which must be set consistently with the u.page and
dma_addr fields.  However, it failed to add the necessary assignment
in efx_resurrect_rx_buffer().  It also did not correct the calculation
of efx_rx_buffer::dma_addr in efx_resurrect_rx_buffer(), which assumes
that DMA-mapping a page will result in a page-aligned DMA address
(exactly what swiotlb violates).

Add the assignment of efx_rx_buffer::page_offset and change the
calculation of dma_addr to make use of it.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
(cherry picked from commit 5f7f65da)

(cherry picked from commit HEAD)
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

This reverts commit 9e443904, which
was commit 57ab0485 upstream.

Taking the semaphore here leads to sleeping in atomic context.  This
was fixed in mainline commit a0c516cb ("zram: don't grab mutex in
zram_slot_free_noity") but that is too difficult to backport.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
(cherry picked from commit 98ed9120)

(cherry picked from commit HEAD)
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

debugfs_remove_recursive() is wrong,

1. it wrongly assumes that !list_empty(d_subdirs) means that this
   dir should be removed.

   This is not that bad by itself, but:

2. if d_subdirs does not becomes empty after __debugfs_remove()
   it gives up and silently fails, it doesn't even try to remove
   other entries.

   However ->d_subdirs can be non-empty because it still has the
   already deleted !debugfs_positive() entries.

3. simple_release_fs() is called even if __debugfs_remove() fails.

Suppose we have

	dir1/
		dir2/
			file2
		file1

and someone opens dir1/dir2/file2.

Now, debugfs_remove_recursive(dir1/dir2) succeeds, and dir1/dir2 goes
away.

But debugfs_remove_recursive(dir1) silently fails and doesn't remove
this directory. Because it tries to delete (the already deleted)
dir1/dir2/file2 again and then fails due to "Avoid infinite loop"
logic.

Test-case:

	#!/bin/sh

	cd /sys/kernel/debug/tracing
	echo 'p:probe/sigprocmask sigprocmask' >> kprobe_events
	sleep 1000 < events/probe/sigprocmask/id &
	echo -n >| kprobe_events

	[ -d events/probe ] && echo "ERR!! failed to rm probe"

And after that it is not possible to create another probe entry.

With this patch debugfs_remove_recursive() skips !debugfs_positive()
files although this is not strictly needed. The most important change
is that it does not try to make ->d_subdirs empty, it simply scans
the whole list(s) recursively and removes as much as possible.

Link: http://lkml.kernel.org/r/20130726151256.GC19472@redhat.comAcked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

(cherry picked from commit 776164c1)
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

We should not do temperature compensation on devices without
EXTERNAL_TX_ALC bit set (called DynamicTxAgcControl on vendor driver).
Such devices can have totally bogus TSSI parameters on the EEPROM,
but still threaded by us as valid and result doing wrong TX power
calculations.

This fix inability to connect to AP on slightly longer distance on
some Ralink chips/devices.
Reported-and-tested-by: Fabien ADAM <id2ndr@crocobox.org>
Cc: stable@vger.kernel.org
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

(cherry picked from commit 6e956da2)
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

If there are UNUSABLE regions in the machine memory map, dom0 will
attempt to map them 1:1 which is not permitted by Xen and the kernel
will crash.

There isn't anything interesting in the UNUSABLE region that the dom0
kernel needs access to so we can avoid making the 1:1 mapping and
treat it as RAM.

We only do this for dom0, as that is where tboot case shows up.
A PV domU could have an UNUSABLE region in its pseudo-physical map
and would need to be handled in another patch.

This fixes a boot failure on hosts with tboot.

tboot marks a region in the e820 map as unusable and the dom0 kernel
would attempt to map this region and Xen does not permit unusable
regions to be mapped by guests.

  (XEN)  0000000000000000 - 0000000000060000 (usable)
  (XEN)  0000000000060000 - 0000000000068000 (reserved)
  (XEN)  0000000000068000 - 000000000009e000 (usable)
  (XEN)  0000000000100000 - 0000000000800000 (usable)
  (XEN)  0000000000800000 - 0000000000972000 (unusable)

tboot marked this region as unusable.

  (XEN)  0000000000972000 - 00000000cf200000 (usable)
  (XEN)  00000000cf200000 - 00000000cf38f000 (reserved)
  (XEN)  00000000cf38f000 - 00000000cf3ce000 (ACPI data)
  (XEN)  00000000cf3ce000 - 00000000d0000000 (reserved)
  (XEN)  00000000e0000000 - 00000000f0000000 (reserved)
  (XEN)  00000000fe000000 - 0000000100000000 (reserved)
  (XEN)  0000000100000000 - 0000000630000000 (usable)
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
[v1: Altered the patch and description with domU's with UNUSABLE regions]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

(cherry picked from commit 3bc38cbc)
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

Otherwise if no references exist in the static kernel image,
we won't export the symbol properly to modules.
Signed-off-by: David S. Miller <davem@davemloft.net>

(cherry picked from commit 74c7b289)
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

Based on copy from microblaze add ucmpdi2 implementation.
This fixes build of niu driver which failed with:

drivers/built-in.o: In function `niu_get_nfc':
niu.c:(.text+0x91494): undefined reference to `__ucmpdi2'

This driver will never be used on a sparc32 system,
but patch added to fix build breakage with all*config builds.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

(cherry picked from commit de36e66d)
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

Due to all of the goodness being packed into today's kernels, the
resulting image isn't as slim as it once was.

In light of this, don't pass -msmall-data to gcc, which otherwise results
in link failures due to impossible relocations when compiling anything but
the most trivial configurations.

Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Reviewed-by: Matt Turner <mattst88@gmail.com>
Tested-by: Thorsten Kranzkowski <dl8bcu@dl8bcu.de>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Michael Cree <mcree@orcon.net.nz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

(cherry picked from commit cd8d2331)
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

Commit d4702b18 ("sound: Fix make allmodconfig on MIPS") added a
(negative) dependency on ISA_DMA_SUPPORT_BROKEN. Since that Kconfig
symbol doesn't exist, this dependency will always evaluate to true.
Apparently GENERIC_ISA_DMA_SUPPORT_BROKEN was meant to be used here.
Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

(cherry picked from commit a62ee234)
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

commit d4702b18 upstream.

The compile of soundcard.c is broken on MIPS when allmodconfig is used
because of the missing MAX_DMA_CHANNELS definition.  As a simple
workaround, just add a Kconfig dependency.
Reported-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
(cherry picked from commit b0538b44)

commit b497ceb9 upstream.

ARM cannot handle udelay for more than 2 miliseconds, so we
should use mdelay instead for those.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: GOTO Masanori <gotom@debian.or.jp>
Cc: YOKOTA Hiroshi <yokota@netlab.is.tsukuba.ac.jp>
Cc: "James E.J. Bottomley" <JBottomley@parallels.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
(cherry picked from commit 6d9ca51b)

(cherry picked from commit HEAD)
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

This reverts commit 5c6156fa, which
was commit cc85b207 upstream.

It broke ARM && PM configurations by adding a call to
genpd_dev_active_wakeup() which was only added in Linux 3.3.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
(cherry picked from commit 3c19c6a8)

(cherry picked from commit HEAD)
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

This patch adds wait_event_interruptible_lock_irq_timeout(), which is a
straight-forward descendant of wait_event_interruptible_timeout() and
wait_event_interruptible_lock_irq().

The zfcp driver used to call wait_event_interruptible_timeout()
in combination with some intricate and error-prone locking. Using
wait_event_interruptible_lock_irq_timeout() as a replacement
nicely cleans up that locking.

This rework removes a situation that resulted in a locking imbalance
in zfcp_qdio_sbal_get():

BUG: workqueue leaked lock or atomic: events/1/0xffffff00/10
    last function: zfcp_fc_wka_port_offline+0x0/0xa0 [zfcp]

It was introduced by commit c2af7545
"[SCSI] zfcp: Do not wait for SBALs on stopped queue", which had a new
code path related to ZFCP_STATUS_ADAPTER_QDIOUP that took an early exit
without a required lock being held. The problem occured when a
special, non-SCSI I/O request was being submitted in process context,
when the adapter's queues had been torn down. In this case the bug
surfaced when the Fibre Channel port connection for a well-known address
was closed during a concurrent adapter shut-down procedure, which is a
rare constellation.

This patch also fixes these warnings from the sparse tool (make C=1):

drivers/s390/scsi/zfcp_qdio.c:224:12: warning: context imbalance in
 'zfcp_qdio_sbal_check' - wrong count at exit
drivers/s390/scsi/zfcp_qdio.c:244:5: warning: context imbalance in
 'zfcp_qdio_sbal_get' - unexpected unlock

Last but not least, we get rid of that crappy lock-unlock-lock
sequence at the beginning of the critical section.

It is okay to call zfcp_erp_adapter_reopen() with req_q_lock held.
Reported-by: Mikulas Patocka <mpatocka@redhat.com>
Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Peschke <mpeschke@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org #2.6.35+
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

(cherry picked from commit d79ff142)
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

tracing_read_pipe zeros all fields bellow "seq". The declaration contains
a comment about that, but it doesn't help.

The first field is "snapshot", it's true when current open file is
snapshot. Looks obvious, that it should not be zeroed.

The second field is "started". It was converted from cpumask_t to
cpumask_var_t (v2.6.28-4983-g4462344e), in other words it was
converted from cpumask to pointer on cpumask.

Currently the reference on "started" memory is lost after the first read
from tracing_read_pipe and a proper object will never be freed.

The "started" is never dereferenced for trace_pipe, because trace_pipe
can't have the TRACE_FILE_ANNOTATE options.

Link: http://lkml.kernel.org/r/1375463803-3085183-1-git-send-email-avagin@openvz.org

Cc: stable@vger.kernel.org # 2.6.30
Signed-off-by: Andrew Vagin <avagin@openvz.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

(cherry picked from commit ed5467da)
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

We used to keep the port's char device structs and the /sys entries
around till the last reference to the port was dropped.  This is
actually unnecessary, and resulted in buggy behaviour:

1. Open port in guest
2. Hot-unplug port
3. Hot-plug a port with the same 'name' property as the unplugged one

This resulted in hot-plug being unsuccessful, as a port with the same
name already exists (even though it was unplugged).

This behaviour resulted in a warning message like this one:

-------------------8<---------------------------------------
WARNING: at fs/sysfs/dir.c:512 sysfs_add_one+0xc9/0x130() (Not tainted)
Hardware name: KVM
sysfs: cannot create duplicate filename
'/devices/pci0000:00/0000:00:04.0/virtio0/virtio-ports/vport0p1'

Call Trace:
 [<ffffffff8106b607>] ? warn_slowpath_common+0x87/0xc0
 [<ffffffff8106b6f6>] ? warn_slowpath_fmt+0x46/0x50
 [<ffffffff811f2319>] ? sysfs_add_one+0xc9/0x130
 [<ffffffff811f23e8>] ? create_dir+0x68/0xb0
 [<ffffffff811f2469>] ? sysfs_create_dir+0x39/0x50
 [<ffffffff81273129>] ? kobject_add_internal+0xb9/0x260
 [<ffffffff812733d8>] ? kobject_add_varg+0x38/0x60
 [<ffffffff812734b4>] ? kobject_add+0x44/0x70
 [<ffffffff81349de4>] ? get_device_parent+0xf4/0x1d0
 [<ffffffff8134b389>] ? device_add+0xc9/0x650

-------------------8<---------------------------------------

Instead of relying on guest applications to release all references to
the ports, we should go ahead and unregister the port from all the core
layers.  Any open/read calls on the port will then just return errors,
and an unplug/plug operation on the host will succeed as expected.

This also caused buggy behaviour in case of the device removal (not just
a port): when the device was removed (which means all ports on that
device are removed automatically as well), the ports with active
users would clean up only when the last references were dropped -- and
it would be too late then to be referencing char device pointers,
resulting in oopses:

-------------------8<---------------------------------------
PID: 6162   TASK: ffff8801147ad500  CPU: 0   COMMAND: "cat"
 #0 [ffff88011b9d5a90] machine_kexec at ffffffff8103232b
 #1 [ffff88011b9d5af0] crash_kexec at ffffffff810b9322
 #2 [ffff88011b9d5bc0] oops_end at ffffffff814f4a50
 #3 [ffff88011b9d5bf0] die at ffffffff8100f26b
 #4 [ffff88011b9d5c20] do_general_protection at ffffffff814f45e2
 #5 [ffff88011b9d5c50] general_protection at ffffffff814f3db5
    [exception RIP: strlen+2]
    RIP: ffffffff81272ae2  RSP: ffff88011b9d5d00  RFLAGS: 00010246
    RAX: 0000000000000000  RBX: ffff880118901c18  RCX: 0000000000000000
    RDX: ffff88011799982c  RSI: 00000000000000d0  RDI: 3a303030302f3030
    RBP: ffff88011b9d5d38   R8: 0000000000000006   R9: ffffffffa0134500
    R10: 0000000000001000  R11: 0000000000001000  R12: ffff880117a1cc10
    R13: 00000000000000d0  R14: 0000000000000017  R15: ffffffff81aff700
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 #6 [ffff88011b9d5d00] kobject_get_path at ffffffff8126dc5d
 #7 [ffff88011b9d5d40] kobject_uevent_env at ffffffff8126e551
 #8 [ffff88011b9d5dd0] kobject_uevent at ffffffff8126e9eb
 #9 [ffff88011b9d5de0] device_del at ffffffff813440c7

-------------------8<---------------------------------------

So clean up when we have all the context, and all that's left to do when
the references to the port have dropped is to free up the port struct
itself.

CC: <stable@vger.kernel.org>
Reported-by: chayang <chayang@redhat.com>
Reported-by: YOGANANTH SUBRAMANIAN <anantyog@in.ibm.com>
Reported-by: FuXiangChun <xfu@redhat.com>
Reported-by: Qunfang Zhang <qzhang@redhat.com>
Reported-by: Sibiao Luo <sluo@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

(cherry picked from commit ea3768b4)
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

I think we could just move the full vm_iomap_memory() function into
util.h or similar, but I didn't get any reply from anybody actually
using nommu even to this trivial patch, so I'm not going to touch it any
more than required.

Here's the fairly minimal stub to make the nommu case at least
potentially work.  It doesn't seem like anybody cares, though.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

(cherry picked from commit 3c0b9de6)
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

NFSv4 reserves readdir cookie values 0-2 for special entries (. and ..),
but jfs allows a value of 2 for a non-special entry. This incompatibility
can result in the nfs client reporting a readdir loop.

This patch doesn't change the value stored internally, but adds one to
the value exposed to the iterate method.
Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Tested-by: Christian Kujau <lists@nerdbynature.de>

(cherry picked from commit 44512449)
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

Judging anonymous memory's vm_area_struct, perf_mmap_event's filename
will be set to "//anon" indicating this vma belongs to anonymous
memory.

Once hugepage is used, vma's vm_file points to hugetlbfs. In this way,
this vma will not be regarded as anonymous memory by is_anon_memory() in
perf user space utility.
Signed-off-by: Joshua Zhu <zhu.wen-jie@hp.com>
Cc: Akihiro Nagai <akihiro.nagai.hw@hitachi.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Joshua Zhu <zhu.wen-jie@hp.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1357363797-3550-1-git-send-email-zhu.wen-jie@hp.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

(cherry picked from commit d0528b5d)
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

sata_inic162x never reached a state where it's reliable enough for
production use and data corruption is a relatively common occurrence.
Make the driver generate warning about the issues and mark the Kconfig
option as experimental.

If the situation doesn't improve, we'd be better off making it depend
on CONFIG_BROKEN.  Let's wait for several cycles and see if the kernel
message draws any attention.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Martin Braure de Calignon <braurede@free.fr>
Reported-by: Ben Hutchings <ben@decadent.org.uk>
Reported-by: risc4all@yahoo.com

(cherry picked from commit bb969619)
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

commit b51c3427 ('ifb: fix rcu_sched self-detected stalls', commit
440d57bc upstream) added a call to cond_resched(), which is
declared in '#include <linux/sched.h>'.  In Linux 3.2.y that header is
included indirectly in some but not all configurations, so add a
direct #include.
Reported-by: Teck Choon Giam <giamteckchoon@gmail.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
(cherry picked from commit 22cbb1bd)

(cherry picked from commit HEAD)
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

The assumption was that update_mmu_cache() (and the equivalent for PMDs) would
only be called when the PTE being installed will be accessible by the user.

This is not true for code paths originating from remove_migration_pte().

There are dire consequences for placing a non-valid PTE into the TSB.  The TLB
miss frramework assumes thatwhen a TSB entry matches we can just load it into
the TLB and return from the TLB miss trap.

So if a non-valid PTE is in there, we will deadlock taking the TLB miss over
and over, never satisfying the miss.

Just exit early from update_mmu_cache() and friends in this situation.

Based upon a report and patch from Christopher Alexander Tobias Schulze.
Signed-off-by: David S. Miller <davem@davemloft.net>

(cherry picked from commit 18f38132)
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

Make espfix64 a hidden Kconfig option.  This fixes the x86-64 UML
build which had broken due to the non-existence of init_espfix_bsp()
in UML: since UML uses its own Kconfig, this option does not appear in
the UML build.

This also makes it possible to make support for 16-bit segments a
configuration option, for the people who want to minimize the size of
the kernel.
Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Richard Weinberger <richard@nod.at>
Link: http://lkml.kernel.org/r/1398816946-3351-1-git-send-email-hpa@linux.intel.com

(cherry picked from commit 197725de)
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

Commit 554086d8 ("x86_32, entry: Do syscall exit work on badsys
(CVE-2014-4508)") introduced a regression in the x86_32 syscall entry
code, resulting in syscall() not returning proper errors for undefined
syscalls on CPUs supporting the sysenter feature.

The following code:

> int result = syscall(666);
> printf("result=%d errno=%d error=%s\n", result, errno, strerror(errno));

results in:

> result=666 errno=0 error=Success

Obviously, the syscall return value is the called syscall number, but it
should have been an ENOSYS error. When run under ptrace it behaves
correctly, which makes it hard to debug in the wild:

> result=-1 errno=38 error=Function not implemented

The %eax register is the return value register. For debugging via ptrace
the syscall entry code stores the complete register context on the
stack. The badsys handlers only store the ENOSYS error code in the
ptrace register set and do not set %eax like a regular syscall handler
would. The old resume_userspace call chain contains code that clobbers
%eax and it restores %eax from the ptrace registers afterwards. The same
goes for the ptrace-enabled call chain. When ptrace is not used, the
syscall return value is the passed-in syscall number from the untouched
%eax register.

Use %eax as the return value register in syscall_badsys and
sysenter_badsys, like a real syscall handler does, and have the caller
push the value onto the stack for ptrace access.
Signed-off-by: Sven Wegener <sven.wegener@stealer.net>
Link: http://lkml.kernel.org/r/alpine.LNX.2.11.1407221022380.31021@titan.int.lan.stealer.netReviewed-and-tested-by: Andy Lutomirski <luto@amacapital.net>
Cc: <stable@vger.kernel.org> # If 554086d8 is backported
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

(cherry picked from commit 8142b215)
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

The commit [247bc037: PM / Sleep: Mitigate race between the freezer
and request_firmware()] introduced the finer state control, but it
also leads to a new bug; for example, a bug report regarding the
firmware loading of intel BT device at suspend/resume:
  https://bugzilla.novell.com/show_bug.cgi?id=873790

The root cause seems to be a small window between the process resume
and the clear of usermodehelper lock.  The request_firmware() function
checks the UMH lock and gives up when it's in UMH_DISABLE state.  This
is for avoiding the invalid  f/w loading during suspend/resume phase.
The problem is, however, that usermodehelper_enable() is called at the
end of thaw_processes().  Thus, a thawed process in between can kick
off the f/w loader code path (in this case, via btusb_setup_intel())
even before the call of usermodehelper_enable().  Then
usermodehelper_read_trylock() returns an error and request_firmware()
spews WARN_ON() in the end.

This oneliner patch fixes the issue just by setting to UMH_FREEZING
state again before restarting tasks, so that the call of
request_firmware() will be blocked until the end of this function
instead of returning an error.

Fixes: 247bc037 (PM / Sleep: Mitigate race between the freezer and request_firmware())
Link: https://bugzilla.novell.com/show_bug.cgi?id=873790
Cc: 3.4+ <stable@vger.kernel.org> # 3.4+
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

(cherry picked from commit 4320f6b1)
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

Sharvil noticed with the posix timer_settime interface, using the
CLOCK_REALTIME_ALARM or CLOCK_BOOTTIME_ALARM clockid, if the users
tried to specify a relative time timer, it would incorrectly be
treated as absolute regardless of the state of the flags argument.

This patch corrects this, properly checking the absolute/relative flag,
as well as adds further error checking that no invalid flag bits are set.
Reported-by: Sharvil Nanavati <sharvil@google.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Sharvil Nanavati <sharvil@google.com>
Cc: stable <stable@vger.kernel.org> #3.0+
Link: http://lkml.kernel.org/r/1404767171-6902-1-git-send-email-john.stultz@linaro.orgSigned-off-by: Thomas Gleixner <tglx@linutronix.de>

(cherry picked from commit 16927776)
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

In some cases we fetch the edid in the detect() callback
in order to determine what sort of monitor is connected.
If that happens, don't fetch the edid again in the get_modes()
callback or we will leak the edid.
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

(cherry picked from commit 0ac66eff)
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

https://bugzilla.kernel.org/show_bug.cgi?id=70191
https://bugzilla.kernel.org/show_bug.cgi?id=77581

It is observed that sometimes Tx packet is downloaded without
adding driver's txpd header. This results in firmware parsing
garbage data as packet length. Sometimes firmware is unable
to read the packet if length comes out as invalid. This stops
further traffic and timeout occurs.

The root cause is uninitialized fields in tx_info(skb->cb) of
packet used to get garbage values. In this case if
MWIFIEX_BUF_FLAG_REQUEUED_PKT flag is mistakenly set, txpd
header was skipped. This patch makes sure that tx_info is
correctly initialized to fix the problem.

Cc: <stable@vger.kernel.org>
Reported-by: Andrew Wiley <wiley.andrew.j@gmail.com>
Reported-by: Linus Gasser <list@markas-al-nour.org>
Reported-by: Michael Hirsch <hirsch@teufel.de>
Tested-by: Xinming Hu <huxm@marvell.com>
Signed-off-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Maithili Hinge <maithili@marvell.com>
Signed-off-by: Avinash Patil <patila@marvell.com>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

(cherry picked from commit d76744a9)
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

Currently, any NMI is falsely handled by a NMI handler of NMI watchdog
if CondChgd bit in MSR_CORE_PERF_GLOBAL_STATUS MSR is set.

For example, we use external NMI to make system panic to get crash
dump, but in this case, the external NMI is falsely handled do to the
issue.

This commit deals with the issue simply by ignoring CondChgd bit.

Here is explanation in detail.

On x86 NMI watchdog uses performance monitoring feature to
periodically signal NMI each time performance counter gets overflowed.

intel_pmu_handle_irq() is called as a NMI_LOCAL handler from a NMI
handler of NMI watchdog, perf_event_nmi_handler(). It identifies an
owner of a given NMI by looking at overflow status bits in
MSR_CORE_PERF_GLOBAL_STATUS MSR. If some of the bits are set, then it
handles the given NMI as its own NMI.

The problem is that the intel_pmu_handle_irq() doesn't distinguish
CondChgd bit from other bits. Unlike the other status bits, CondChgd
bit doesn't represent overflow status for performance counters. Thus,
CondChgd bit cannot be thought of as a mark indicating a given NMI is
NMI watchdog's.

As a result, if CondChgd bit is set, any NMI is falsely handled by the
NMI handler of NMI watchdog. Also, if type of the falsely handled NMI
is either NMI_UNKNOWN, NMI_SERR or NMI_IO_CHECK, the corresponding
action is never performed until CondChgd bit is cleared.

I noticed this behavior on systems with Ivy Bridge processors: Intel
Xeon CPU E5-2630 v2 and Intel Xeon CPU E7-8890 v2. On both systems,
CondChgd bit in MSR_CORE_PERF_GLOBAL_STATUS MSR has already been set
in the beginning at boot. Then the CondChgd bit is immediately cleared
by next wrmsr to MSR_CORE_PERF_GLOBAL_CTRL MSR and appears to remain
0.

On the other hand, on older processors such as Nehalem, Xeon E7540,
CondChgd bit is not set in the beginning at boot.

I'm not sure about exact behavior of CondChgd bit, in particular when
this bit is set. Although I read Intel System Programmer's Manual to
figure out that, the descriptions I found are:

  In 18.9.1:

  "The MSR_PERF_GLOBAL_STATUS MSR also provides a ¡sticky bit¢ to
   indicate changes to the state of performancmonitoring hardware"

  In Table 35-2 IA-32 Architectural MSRs

  63 CondChg: status bits of this register has changed.

These are different from the bahviour I see on the actual system as I
explained above.

At least, I think ignoring CondChgd bit should be enough for NMI
watchdog perspective.
Signed-off-by: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Acked-by: Don Zickus <dzickus@redhat.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: <stable@vger.kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/20140625.103503.409316067.d.hatayama@jp.fujitsu.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

(cherry picked from commit b292d7a1)
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

There is a benign buffer overflow in ip_options_compile spotted by
AddressSanitizer[1] :

Its benign because we always can access one extra byte in skb->head
(because header is followed by struct skb_shared_info), and in this case
this byte is not even used.

[28504.910798] ==================================================================
[28504.912046] AddressSanitizer: heap-buffer-overflow in ip_options_compile
[28504.913170] Read of size 1 by thread T15843:
[28504.914026]  [<ffffffff81802f91>] ip_options_compile+0x121/0x9c0
[28504.915394]  [<ffffffff81804a0d>] ip_options_get_from_user+0xad/0x120
[28504.916843]  [<ffffffff8180dedf>] do_ip_setsockopt.isra.15+0x8df/0x1630
[28504.918175]  [<ffffffff8180ec60>] ip_setsockopt+0x30/0xa0
[28504.919490]  [<ffffffff8181e59b>] tcp_setsockopt+0x5b/0x90
[28504.920835]  [<ffffffff8177462f>] sock_common_setsockopt+0x5f/0x70
[28504.922208]  [<ffffffff817729c2>] SyS_setsockopt+0xa2/0x140
[28504.923459]  [<ffffffff818cfb69>] system_call_fastpath+0x16/0x1b
[28504.924722]
[28504.925106] Allocated by thread T15843:
[28504.925815]  [<ffffffff81804995>] ip_options_get_from_user+0x35/0x120
[28504.926884]  [<ffffffff8180dedf>] do_ip_setsockopt.isra.15+0x8df/0x1630
[28504.927975]  [<ffffffff8180ec60>] ip_setsockopt+0x30/0xa0
[28504.929175]  [<ffffffff8181e59b>] tcp_setsockopt+0x5b/0x90
[28504.930400]  [<ffffffff8177462f>] sock_common_setsockopt+0x5f/0x70
[28504.931677]  [<ffffffff817729c2>] SyS_setsockopt+0xa2/0x140
[28504.932851]  [<ffffffff818cfb69>] system_call_fastpath+0x16/0x1b
[28504.934018]
[28504.934377] The buggy address ffff880026382828 is located 0 bytes to the right
[28504.934377]  of 40-byte region [ffff880026382800, ffff880026382828)
[28504.937144]
[28504.937474] Memory state around the buggy address:
[28504.938430]  ffff880026382300: ........ rrrrrrrr rrrrrrrr rrrrrrrr
[28504.939884]  ffff880026382400: ffffffff rrrrrrrr rrrrrrrr rrrrrrrr
[28504.941294]  ffff880026382500: .....rrr rrrrrrrr rrrrrrrr rrrrrrrr
[28504.942504]  ffff880026382600: ffffffff rrrrrrrr rrrrrrrr rrrrrrrr
[28504.943483]  ffff880026382700: ffffffff rrrrrrrr rrrrrrrr rrrrrrrr
[28504.944511] >ffff880026382800: .....rrr rrrrrrrr rrrrrrrr rrrrrrrr
[28504.945573]                         ^
[28504.946277]  ffff880026382900: ffffffff rrrrrrrr rrrrrrrr rrrrrrrr
[28505.094949]  ffff880026382a00: ffffffff rrrrrrrr rrrrrrrr rrrrrrrr
[28505.096114]  ffff880026382b00: ffffffff rrrrrrrr rrrrrrrr rrrrrrrr
[28505.097116]  ffff880026382c00: ffffffff rrrrrrrr rrrrrrrr rrrrrrrr
[28505.098472]  ffff880026382d00: ffffffff rrrrrrrr rrrrrrrr rrrrrrrr
[28505.099804] Legend:
[28505.100269]  f - 8 freed bytes
[28505.100884]  r - 8 redzone bytes
[28505.101649]  . - 8 allocated bytes
[28505.102406]  x=1..7 - x allocated bytes + (8-x) redzone bytes
[28505.103637] ==================================================================

[1] https://code.google.com/p/address-sanitizer/wiki/AddressSanitizerForKernelSigned-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

(cherry picked from commit 10ec9472)
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

*_result[len] is parsed as *(_result[len]) which is not at all what we
want to touch here.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Fixes: 84a7c0b1 ("dns_resolver: assure that dns_query() result is null-terminated")
Signed-off-by: David S. Miller <davem@davemloft.net>

(cherry picked from commit 640d7efe)
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

[ Upstream commit 84a7c0b1 ]

dns_query() credulously assumes that keys are null-terminated and
returns a copy of a memory block that is off by one.
Signed-off-by: Manuel Schölling <manuel.schoelling@gmx.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit c304a23b)

Nothing cleans up the objects created by
vnet_new(), they are completely leaked.

vnet_exit(), after doing the vio_unregister_driver() to clean
up ports, should call a helper function that iterates over vnet_list
and cleans up those objects. This includes unregister_netdevice()
as well as free_netdev().
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Acked-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Reviewed-by: Karl Volz <karl.volz@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

(cherry picked from commit a4b70a07)
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

The PPP channel MTU is used with Multilink PPP when ppp_mp_explode() (see
ppp_generic module) tries to determine how big a fragment might be. According
to RFC 1661, the MTU excludes the 2-byte PPP protocol field, see the
corresponding comment and code in ppp_mp_explode():

		/*
		 * hdrlen includes the 2-byte PPP protocol field, but the
		 * MTU counts only the payload excluding the protocol field.
		 * (RFC1661 Section 2)
		 */
		mtu = pch->chan->mtu - (hdrlen - 2);

However, the pppoe module *does* include the PPP protocol field in the channel
MTU, which is wrong as it causes the PPP payload to be 1-2 bytes too big under
certain circumstances (one byte if PPP protocol compression is used, two
otherwise), causing the generated Ethernet packets to be dropped. So the pppoe
module has to subtract two bytes from the channel MTU. This error only
manifests itself when using Multilink PPP, as otherwise the channel MTU is not
used anywhere.

In the following, I will describe how to reproduce this bug. We configure two
pppd instances for multilink PPP over two PPPoE links, say eth2 and eth3, with
a MTU of 1492 bytes for each link and a MRRU of 2976 bytes. (This MRRU is
computed by adding the two link MTUs and subtracting the MP header twice, which
is 4 bytes long.) The necessary pppd statements on both sides are "multilink
mtu 1492 mru 1492 mrru 2976". On the client side, we additionally need "plugin
rp-pppoe.so eth2" and "plugin rp-pppoe.so eth3", respectively; on the server
side, we additionally need to start two pppoe-server instances to be able to
establish two PPPoE sessions, one over eth2 and one over eth3. We set the MTU
of the PPP network interface to the MRRU (2976) on both sides of the connection
in order to make use of the higher bandwidth. (If we didn't do that, IP
fragmentation would kick in, which we want to avoid.)

Now we send a ICMPv4 echo request with a payload of 2948 bytes from client to
server over the PPP link. This results in the following network packet:

   2948 (echo payload)
 +    8 (ICMPv4 header)
 +   20 (IPv4 header)
---------------------
   2976 (PPP payload)

These 2976 bytes do not exceed the MTU of the PPP network interface, so the
IP packet is not fragmented. Now the multilink PPP code in ppp_mp_explode()
prepends one protocol byte (0x21 for IPv4), making the packet one byte bigger
than the negotiated MRRU. So this packet would have to be divided in three
fragments. But this does not happen as each link MTU is assumed to be two bytes
larger. So this packet is diveded into two fragments only, one of size 1489 and
one of size 1488. Now we have for that bigger fragment:

   1489 (PPP payload)
 +    4 (MP header)
 +    2 (PPP protocol field for the MP payload (0x3d))
 +    6 (PPPoE header)
--------------------------
   1501 (Ethernet payload)

This packet exceeds the link MTU and is discarded.

If one configures the link MTU on the client side to 1501, one can see the
discarded Ethernet frames with tcpdump running on the client. A

ping -s 2948 -c 1 192.168.15.254

leads to the smaller fragment that is correctly received on the server side:

(tcpdump -vvvne -i eth3 pppoes and ppp proto 0x3d)
52:54:00:ad:87:fd > 52:54:00:79:5c:d0, ethertype PPPoE S (0x8864),
  length 1514: PPPoE  [ses 0x3] MLPPP (0x003d), length 1494: seq 0x000,
  Flags [end], length 1492

and to the bigger fragment that is not received on the server side:

(tcpdump -vvvne -i eth2 pppoes and ppp proto 0x3d)
52:54:00:70:9e:89 > 52:54:00:5d:6f:b0, ethertype PPPoE S (0x8864),
  length 1515: PPPoE  [ses 0x5] MLPPP (0x003d), length 1495: seq 0x000,
  Flags [begin], length 1493

With the patch below, we correctly obtain three fragments:

52:54:00:ad:87:fd > 52:54:00:79:5c:d0, ethertype PPPoE S (0x8864),
  length 1514: PPPoE  [ses 0x1] MLPPP (0x003d), length 1494: seq 0x000,
  Flags [begin], length 1492
52:54:00:70:9e:89 > 52:54:00:5d:6f:b0, ethertype PPPoE S (0x8864),
  length 1514: PPPoE  [ses 0x1] MLPPP (0x003d), length 1494: seq 0x000,
  Flags [none], length 1492
52:54:00:ad:87:fd > 52:54:00:79:5c:d0, ethertype PPPoE S (0x8864),
  length 27: PPPoE  [ses 0x1] MLPPP (0x003d), length 7: seq 0x000,
  Flags [end], length 5

And the ICMPv4 echo request is successfully received at the server side:

IP (tos 0x0, ttl 64, id 21925, offset 0, flags [DF], proto ICMP (1),
  length 2976)
    192.168.222.2 > 192.168.15.254: ICMP echo request, id 30530, seq 0,
      length 2956

The bug was introduced in commit c9aa6895
("[PPPOE]: Advertise PPPoE MTU") from the very beginning. This patch applies
to 3.10 upwards but the fix can be applied (with minor modifications) to
kernels as old as 2.6.32.
Signed-off-by: Christoph Schulz <develop@kristov.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

(cherry picked from commit a8a3e41c)
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>