* 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6:
  [S390] ap: Setup timer for sending messages after reset.
  [S390] cio: fix chsc_chp_vary
  [S390] cio: provide fake irb for transport mode IO
  [S390] cio: disallow driver io for known to be broken paths
  [S390] hibernate: directly trigger subchannel evaluation
  [S390] remove reset of system call restart on psw changes
  [S390] add missing .set function for NT_S390_LAST_BREAK regset
  [S390] fix page change underindication in pgste_update_all
  [S390] ptrace inferior call interactions with TIF_SYSCALL
  [S390] kdump: Replace is_kdump_kernel() with OLDMEM_BASE check

I screwed up by compiling that driver for the machine rather
than the arch. Correcting this fixes the build error.

Cc: Grant Likely <grant.likely@secretlab.ca>
Reported-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

People with old AMD chips are getting hung boots, because commit
bcb80e53 ("x86, microcode, AMD: Add microcode revision to
/proc/cpuinfo") moved the microcode detection too early into
"early_init_amd()".

At that point we are *so* early in the booth that the exception tables
haven't even been set up yet, so the whole

	rdmsr_safe(MSR_AMD64_PATCH_LEVEL, &c->microcode, &dummy);

doesn't actually work: if the rdmsr does a GP fault (due to non-existant
MSR register on older CPU's), we can't fix it up yet, and the boot fails.

Fix it by simply moving the code to a slightly later point in the boot
(init_amd() instead of early_init_amd()), since the kernel itself
doesn't even really care about the microcode patchlevel at this point
(or really ever: it's made available to user space in /proc/cpuinfo, and
updated if you do a microcode load).
Reported-tested-and-bisected-by: Larry Finger <Larry.Finger@lwfinger.net>
Tested-by: Bob Tracy <rct@gherkin.frus.com>
Acked-by: Borislav Petkov <borislav.petkov@amd.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The idea behind commit d91ee586 ("cpuidle: replace xen access to x86
pm_idle and default_idle") was to have one call - disable_cpuidle()
which would make pm_idle not be molested by other code.  It disallows
cpuidle_idle_call to be set to pm_idle (which is excellent).

But in the select_idle_routine() and idle_setup(), the pm_idle can still
be set to either: amd_e400_idle, mwait_idle or default_idle.  This
depends on some CPU flags (MWAIT) and in AMD case on the type of CPU.

In case of mwait_idle we can hit some instances where the hypervisor
(Amazon EC2 specifically) sets the MWAIT and we get:

  Brought up 2 CPUs
  invalid opcode: 0000 [#1] SMP

  Pid: 0, comm: swapper Not tainted 3.1.0-0.rc6.git0.3.fc16.x86_64 #1
  RIP: e030:[<ffffffff81015d1d>]  [<ffffffff81015d1d>] mwait_idle+0x6f/0xb4
  ...
  Call Trace:
   [<ffffffff8100e2ed>] cpu_idle+0xae/0xe8
   [<ffffffff8149ee78>] cpu_bringup_and_idle+0xe/0x10
  RIP  [<ffffffff81015d1d>] mwait_idle+0x6f/0xb4
   RSP <ffff8801d28ddf10>

In the case of amd_e400_idle we don't get so spectacular crashes, but we
do end up making an MSR which is trapped in the hypervisor, and then
follow it up with a yield hypercall.  Meaning we end up going to
hypervisor twice instead of just once.

The previous behavior before v3.0 was that pm_idle was set to
default_idle regardless of select_idle_routine/idle_setup.

We want to do that, but only for one specific case: Xen.  This patch
does that.

Fixes RH BZ #739499 and Ubuntu #881076
Reported-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* 'usb-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (21 commits)
  usb: ftdi_sio: add PID for Propox ISPcable III
  Revert "xHCI: reset-on-resume quirk for NEC uPD720200"
  xHCI: fix bug in xhci_clear_command_ring()
  usb: gadget: fsl_udc: fix dequeuing a request in progress
  usb: fsl_mxc_udc.c: Remove compile-time dependency of MX35 SoC type
  usb: fsl_mxc_udc.c: Fix build issue by including missing header file
  USB: fsl_udc_core: use usb_endpoint_xfer_isoc to judge ISO XFER
  usb: udc: Fix gadget driver's speed check in various UDC drivers
  usb: gadget: fix g_serial regression
  usb: renesas_usbhs: fixup driver speed
  usb: renesas_usbhs: fixup gadget.dev.driver when udc_stop.
  usb: renesas_usbhs: fixup signal the driver that cable was disconnected
  usb: renesas_usbhs: fixup device_register timing
  usb: musb: PM: fix context save/restore in suspend/resume path
  USB: linux-cdc-acm.inf: add support for the acm_ms gadget
  EHCI : Fix a regression in the ISO scheduler
  xHCI: reset-on-resume quirk for NEC uPD720200
  USB: whci-hcd: fix endian conversion in qset_clear()
  USB: usb-storage: unusual_devs entry for Kingston DT 101 G2
  usb: option: add SIMCom SIM5218
  ...

* 'staging-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  Staging: comedi: fix integer overflow in do_insnlist_ioctl()
  Revert "Staging: comedi: integer overflow in do_insnlist_ioctl()"
  Staging: comedi: integer overflow in do_insnlist_ioctl()
  Staging: comedi: fix signal handling in read and write
  Staging: comedi: fix mmap_count
  staging: comedi: fix oops for USB DAQ devices.
  staging: comedi: usbduxsigma: Fixed wrong range for the analogue channel.
  staging:rts_pstor:Complete scanning_done variable
  staging: usbip: bugfix for deadlock

* 'for-linus' of git://oss.sgi.com/xfs/xfs:
  xfs: fix attr2 vs large data fork assert
  xfs: force buffer writeback before blocking on the ilock in inode reclaim
  xfs: validate acl count

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid:
  HID: Correct General touch PID

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
  vmwgfx: integer overflow in vmw_kms_update_layout_ioctl()
  drm/radeon/kms: fix 2D tiling CS support on EG/CM
  drm/radeon/kms: fix scanout of 2D tiled buffers on EG/CM
  drm: Fix lack of CRTC disable for drm_crtc_helper_set_config(.fb=NULL)
  drm/radeon/kms: add some new pci ids
  drm/radeon/kms: Skip ACPI call to ATIF when possible
  drm/radeon/kms: Hide debugging message
  drm/radeon/kms: add some loop timeouts in pageflip code
  drm/nv50/disp: silence compiler warning
  drm/nouveau: fix oopses caused by clear being called on unpopulated ttms
  drm/nouveau: Keep RAMIN heap within the channel.
  drm/nvd0/disp: fix sor dpms typo, preventing dpms on in some situations
  drm/nvc0/gr: fix TP init for transform feedback offset queries
  drm/nouveau: add dumb ioctl support

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: hda - Fix S3/S4 problem on machines with VREF-pin mute-LED
  ALSA: hda_intel - revert a quirk that affect VIA chipsets
  ALSA: hda - Avoid touching mute-VREF pin for IDT codecs
  firmware: Sigma: Fix endianess issues
  firmware: Sigma: Skip header during CRC generation
  firmware: Sigma: Prevent out of bounds memory access
  ALSA: usb-audio - Support for Roland GAIA SH-01 Synthesizer
  ASoC: Supply dcs_codes for newer WM1811 revisions
  ASoC: Error out if we can't generate a LRCLK at all for WM8994
  ASoC: Correct name of Speyside Main Speaker widget
  ASoC: skip resume of soc-audio devices without codecs
  ASoC: cs42l51: Fix off-by-one for reg_cache_size
  ASoC: drop support for PlayPaq with WM8510
  ASoC: mpc8610: tell the CS4270 codec that it's the master
  ASoC: cs4720: use snd_soc_cache_sync()
  ASoC: SAMSUNG: Fix build error
  ASoC: max9877: Update register if either val or val2 is changed
  ASoC: Fix wrong define for AD1836_ADC_WORD_OFFSET

There are two issues in vmw_kms_update_layout_ioctl().  First, the
for loop forgets to index rects and only checks the first element.
Second, there is a potential integer overflow if userspace passes
in a large arg->num_outputs.  The call to kzalloc() would allocate
a small buffer, leading to out-of-bounds read.
Reported-by: Haogang Chen <haogangchen@gmail.com>
Signed-off-by: Xi Wang <xi.wang@gmail.com>
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

Fixes:
https://bugs.freedesktop.org/show_bug.cgi?id=43191Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

Fixes:
https://bugs.freedesktop.org/show_bug.cgi?id=43191Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

Disabling the CRTC by setting its framebuffer to NULL, as used by
drm_framebuffer_cleanup(), was failing to pass the current framebuffer
to the crtc_func->disable callback. This is because of the dance within
drm_crtc_helper_set_config to pass the new_fb (NULL in this case) to the
drm_crtc_helper_set_mode with the currently attached fb as a parameter.
drm_crtc_helper_set_mode treats this as a no-op and the encoder is still
enabled. And so the current fb is forgotten before the call to
drm_helper_disable_unused_functions.

This patch treats disabling the CRTC as a simple special case rather
than adding further complexity into the configuration logic.

This fixes a pin-leak of the fb bo on Xserver close.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Dave Airlie <airlied@redhat.com>

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (73 commits)
  netfilter: Remove ADVANCED dependency from NF_CONNTRACK_NETBIOS_NS
  ipv4: flush route cache after change accept_local
  sch_red: fix red_change
  Revert "udp: remove redundant variable"
  bridge: master device stuck in no-carrier state forever when in user-stp mode
  ipv4: Perform peer validation on cached route lookup.
  net/core: fix rollback handler in register_netdevice_notifier
  sch_red: fix red_calc_qavg_from_idle_time
  bonding: only use primary address for ARP
  ipv4: fix lockdep splat in rt_cache_seq_show
  sch_teql: fix lockdep splat
  net: fec: Select the FEC driver by default for i.MX SoCs
  isdn: avoid copying too long drvid
  isdn: make sure strings are null terminated
  netlabel: Fix build problems when IPv6 is not enabled
  sctp: better integer overflow check in sctp_auth_create_key()
  sctp: integer overflow in sctp_auth_create_key()
  ipv6: Set mcast_hops to IPV6_DEFAULT_MCASTHOPS when -1 was given.
  net: Fix corruption in /proc/*/net/dev_mcast
  mac80211: fix race between the AGG SM and the Tx data path
  ...

firewalld in Fedora 16 needs this.
Signed-off-by: David S. Miller <davem@davemloft.net>

After reset ipv4_devconf->data[IPV4_DEVCONF_ACCEPT_LOCAL] to 0,
we should flush route cache, or it will continue receive packets with local
source address, which should be dropped.
Signed-off-by: Weiping Pan <panweiping3@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Le mercredi 30 novembre 2011 à 14:36 -0800, Stephen Hemminger a écrit :

> (Almost) nobody uses RED because they can't figure it out.
> According to Wikipedia, VJ says that:
>  "there are not one, but two bugs in classic RED."

RED is useful for high throughput routers, I doubt many linux machines
act as such devices.

I was considering adding Adaptative RED (Sally Floyd, Ramakrishna
Gummadi, Scott Shender), August 2001

In this version, maxp is dynamic (from 1% to 50%), and user only have to
setup min_th (target average queue size)
(max_th and wq (burst in linux RED) are automatically setup)

By the way it seems we have a small bug in red_change()

if (skb_queue_empty(&sch->q))
	red_end_of_idle_period(&q->parms);

First, if queue is empty, we should call
red_start_of_idle_period(&q->parms);

Second, since we dont use anymore sch->q, but q->qdisc, the test is
meaningless.

Oh well...

[PATCH] sch_red: fix red_change()

Now RED is classful, we must check q->qdisc->q.qlen, and if queue is empty,
we start an idle period, not end it.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jlbec/ocfs2: (31 commits)
  ocfs2: avoid unaligned access to dqc_bitmap
  ocfs2: Use filemap_write_and_wait() instead of write_inode_now()
  ocfs2: honor O_(D)SYNC flag in fallocate
  ocfs2: Add a missing journal credit in ocfs2_link_credits() -v2
  ocfs2: send correct UUID to cleancache initialization
  ocfs2: Commit transactions in error cases -v2
  ocfs2: make direntry invalid when deleting it
  fs/ocfs2/dlm/dlmlock.c: free kmem_cache_zalloc'd data using kmem_cache_free
  ocfs2: Avoid livelock in ocfs2_readpage()
  ocfs2: serialize unaligned aio
  ocfs2: Implement llseek()
  ocfs2: Fix ocfs2_page_mkwrite()
  ocfs2: Add comment about orphan scanning
  ocfs2: Clean up messages in the fs
  ocfs2/cluster: Cluster up now includes network connections too
  ocfs2/cluster: Add new function o2net_fill_node_map()
  ocfs2/cluster: Fix output in file elapsed_time_in_ms
  ocfs2/dlm: dlmlock_remote() needs to account for remastery
  ocfs2/dlm: Take inflight reference count for remotely mastered resources too
  ocfs2/dlm: Cleanup dlm_wait_for_node_death() and dlm_wait_for_node_recovery()
  ...

The dqc_bitmap field of struct ocfs2_local_disk_chunk is 32-bit aligned,
but not 64-bit aligned.  The dqc_bitmap is accessed by ocfs2_set_bit(),
ocfs2_clear_bit(), ocfs2_test_bit(), or ocfs2_find_next_zero_bit().  These
are wrapper macros for ext2_*_bit() which need to take an unsigned long
aligned address (though some architectures are able to handle unaligned
address correctly)

So some 64bit architectures may not be able to access the dqc_bitmap
correctly.

This avoids such unaligned access by using another wrapper functions for
ext2_*_bit().  The code is taken from fs/ext4/mballoc.c which also need to
handle unaligned bitmap access.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Acked-by: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Joel Becker <jlbec@evilplan.org>

* 'fixes' of http://ftp.arm.linux.org.uk/pub/linux/arm/kernel/git-cur/linux-2.6-arm:
  ARM: 7182/1: ARM cpu topology: fix warning
  ARM: 7181/1: Restrict kprobes probing SWP instructions to ARMv5 and below
  ARM: 7180/1: Change kprobes testcase with unpredictable STRD instruction
  ARM: 7177/1: GIC: avoid skipping non-existent PPIs in irq_start calculation
  ARM: 7176/1: cpu_pm: register GIC PM notifier only once
  ARM: 7175/1: add subname parameter to mfp_set_groupg callers
  ARM: 7174/1: Fix build error in kprobes test code on Thumb2 kernels
  ARM: 7172/1: dma: Drop GFP_COMP for DMA memory allocations
  ARM: 7171/1: unwind: add unwind directives to bitops assembly macros
  ARM: 7170/2: fix compilation breakage in entry-armv.S
  ARM: 7168/1: use cache type functions for arch_get_unmapped_area
  ARM: perf: check that we have a platform device when reserving PMU
  ARM: 7166/1: Use PMD_SHIFT instead of PGDIR_SHIFT in dma-consistent.c
  ARM: 7165/2: PL330: Fix typo in _prepare_ccr()
  ARM: 7163/2: PL330: Only register usable channels
  ARM: 7162/1: errata: tidy up Kconfig options for PL310 errata workarounds
  ARM: 7161/1: errata: no automatic store buffer drain
  ARM: perf: initialise used_mask for fake PMU during validation
  ARM: PMU: remove pmu_init declaration
  ARM: PMU: re-export release_pmu symbol to modules

This reverts commit 81d54ec8.

If we take the "try_again" goto, due to a checksum error,
the 'len' has already been truncated.  So we won't compute
the same values as the original code did.
Reported-by: paul bilke <fsmail@conspiracy.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

Merge branch 'for-usb-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sarah/xhci into usb-linus

* 'for-usb-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sarah/xhci:
  Revert "xHCI: reset-on-resume quirk for NEC uPD720200"
  xHCI: fix bug in xhci_clear_command_ring()

When in user-stp mode, bridge master do not follow state of its slaves, so
after the following sequence of events it can stuck forever in no-carrier
state:
1) turn stp off
2) put all slaves down - master device will follow their state and also go in
no-carrier state
3) turn stp on with bridge-stp script returning 0 (go to the user-stp mode)
Now bridge master won't follow slaves' state and will never reach running
state.

This patch solves the problem by making user-stp and kernel-stp behavior
similar regarding master following slaves' states.
Signed-off-by: Vitalii Demianets <vitas@nppfactor.kiev.ua>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Signed-off-by: Marcin Kościelnicki <koriakin@0x04.net>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

This reverts commit df711fc9.

The commit added a reset-on-resume quirk because the NEC chipset stopped
responding to commands about 30 minutes after a system resume from
suspend.  We thought it was a chipset issue, but it turns out that the
xHCI driver was zeroing out the link TRB after a successful context
restore during resume.  The host controller would fall off the command
ring sometime later, causing it to not respond to new commands.

The link TRB issue has been fixed with commit
158886cd "xHCI: fix bug in
xhci_clear_command_ring()", so revert the reset-on-resume quirk, as it's
not necessary.

Commit df711fc9 was marked for stable
trees back to 2.6.37, but according to my mail, it has not made it into
Linus' tree or the stable trees yet.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Tested-by: Julian Sikorski <belegdol@gmail.com>
Cc: Andiry Xu <andiry.xu@amd.com>

Otherwise we won't notice the peer GENID change.
Reported-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When system enters suspend, xHCI driver clears command ring by writing zero
to all the TRBs. However, this also writes zero to the Link TRB, and the ring
is mangled. This may cause driver accesses wrong memory address and the
result is unpredicted.

When clear the command ring, keep the last Link TRB intact, only clear its
cycle bit. This should fix the "command ring full" issue reported by Oliver
Neukum.

This should be backported to stable kernels as old as 2.6.37, since the
commit 89821320 "xhci: Fix command ring replay after resume" is merged.
Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Reported-by: Oliver Neukum <oneukum@suse.de>

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: fix meta data raid-repair merge problem
  Btrfs: skip allocation attempt from empty cluster
  Btrfs: skip block groups without enough space for a cluster
  Btrfs: start search for new cluster at the beginning
  Btrfs: reset cluster's max_size when creating bitmap
  Btrfs: initialize new bitmaps' list
  Btrfs: fix oops when calling statfs on readonly device
  Btrfs: Don't error on resizing FS to same size
  Btrfs: fix deadlock on metadata reservation when evicting a inode
  Fix URL of btrfs-progs git repository in docs
  btrfs scrub: handle -ENOMEM from init_ipath()

Commit 4a54c8c1 introduced raid-repair, killing the individual
readpage_io_failed_hook entries from inode.c and disk-io.c. Commit
4bb31e92 introduced new readahead code, adding a readpage_io_failed_hook to
disk-io.c.

The raid-repair commit had logic to disable raid-repair, if
readpage_io_failed_hook is set. Thus, the readahead commit effectively
disabled raid-repair for meta data.

This commit changes the logic to always attempt raid-repair when needed and
call the readpage_io_failed_hook in case raid-repair fails. This is much
more straight forward and should have been like that from the beginning.
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
Reported-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

Setup timer for processing messages in request queue after a
successful AP bus device reset.
Signed-off-by: Holger Dengler <hd@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

The functions called by chsc_chp_vary operate on pointers to channel
path ids not channel path links. (This worked by chance since the id
is the first member of the link structure)
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

If a driver wants to do command mode IO while CIO is doing
online path verification we ignore this request and provide
a fake irb when we are done and the driver can do IO again.

For transport mode IO we have no such mechanism, giving the
driver no other chance then to retry the action until we are
done. This is not very reliable.

Provide a fake irb for transport mode IO as well.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

When a driver requests to do IO, we will adjust the mask of
paths to be used to exclude varied offline paths.

Drivers trying to do IO solely on paths which are online but some
way defective may lack the information to do proper error handling.

There is no reason to allow the usage of known to be broken paths.
Thus restrict the paths a ccw driver can use for IO to a subset of
the paths cio found usable (this also excludes offline paths).
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

Using the generic css_schedule_eval to evaluate subchannels
while resuming from hibernation is very slow when used with
many devices. Provide a new evaluation trigger which exploits
css_sched_sch_todo and use this in the resume callback for
ccw devices.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

git commit 20b40a79 "signal race with restarting system calls"
added code to the poke_user/poke_user_compat to reset the system call
restart information in the thread-info if the PSW address is changed.
The purpose of that change has been to workaround old gdbs that do
not know about the REGSET_SYSTEM_CALL. It turned out that this is not
a good idea, it makes the behaviour of the debuggee dependent on the
order of specific ptrace call, e.g. the REGSET_SYSTEM_CALL register
set needs to be written last. And the workaround does not really fix
old gdbs, inferior calls on interrupted restarting system calls do not
work either way.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

The last breaking event address is a read-only value, the regset misses the
.set function. If a PTRACE_SETREGSET is done for NT_S390_LAST_BREAK we
get an oops due to a branch to zero:

Kernel BUG at 0000000000000002 verbose debug info unavailable
illegal operation: 0001 #1 SMP
...
Call Trace:
(<0000000000158294> ptrace_regset+0x184/0x188)
 <00000000001595b6> ptrace_request+0x37a/0x4fc
 <0000000000109a78> arch_ptrace+0x108/0x1fc
 <00000000001590d6> SyS_ptrace+0xaa/0x12c
 <00000000005c7a42> sysc_noemu+0x16/0x1c
 <000003fffd5ec10c> 0x3fffd5ec10c
Last Breaking-Event-Address:
 <0000000000158242> ptrace_regset+0x132/0x188

Add a nop .set function to prevent the branch to zero.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: stable@kernel.org