ARM: 7306/1: vfp: flush thread hwstate before restoring context from sigframe

commit 2af276dfb1722e97b190bd2e646b079a2aa674db upstream.

Following execution of a signal handler, we currently restore the VFP
context from the ucontext in the signal frame. This involves copying
from the user stack into the current thread's vfp_hard_struct and then
flushing the new data out to the hardware registers.

This is problematic when using a preemptible kernel because we could be
context switched whilst updating the vfp_hard_struct. If the current
thread has made use of VFP since the last context switch, the VFP
notifier will copy from the hardware registers into the vfp_hard_struct,
overwriting any data that had been partially copied by the signal code.

Disabling preemption across copy_from_user calls is a terrible idea, so
instead we move the VFP thread flush *before* we update the
vfp_hard_struct. Since the flushing is performed lazily, this has the
effect of disabling VFP and clearing the CPU's VFP state pointer,
therefore preventing the thread from being updated with stale data on
the next context switch.

Tested-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ARM: 7307/1: vfp: fix ptrace regset modification race

commit 247f4993a5974e6759606c4d380748eecfd273ff upstream.

In a preemptible kernel, vfp_set() can be preempted, causing the
hardware VFP context to be switched while the thread vfp state is
being read and modified.  This leads to a race condition which can
cause the thread vfp state to become corrupted if lazy VFP context
save occurs due to preemption in between the time thread->vfpstate
is read and the time the modified state is written back.

This may occur if preemption occurs during the execution of a
ptrace() call which modifies the VFP register state of a thread.
Such instances should be very rare in most realistic scenarios --
none has been reported, so far as I am aware.  Only uniprocessor
systems should be affected, since VFP context save is not currently
lazy in SMP kernels.

The problem was introduced by my earlier patch migrating to use
regsets to implement ptrace.

This patch does a vfp_sync_hwstate() before reading
thread->vfpstate, to make sure that the thread's VFP state is not
live in the hardware registers while the registers are modified.

Thanks to Will Deacon for spotting this.

Signed-off-by: Dave Martin <dave.martin@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ARM: 7308/1: vfp: flush thread hwstate before copying ptrace registers

commit 8130b9d7b9d858aa04ce67805e8951e3cb6e9b2f upstream.

If we are context switched whilst copying into a thread's
vfp_hard_struct then the partial copy may be corrupted by the VFP
context switching code (see "ARM: vfp: flush thread hwstate before
restoring context from sigframe").

This patch updates the ptrace VFP set code so that the thread state is
flushed before the copy, therefore disabling VFP and preventing
corruption from occurring.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ARM: OMAP2+: GPMC: fix device size setup

commit 8ef5d844cc3a644ea6f7665932a4307e9fad01fa upstream.

following statement can only change device size from 8-bit(0) to 16-bit(1),
but not vice versa:

regval |= GPMC_CONFIG1_DEVICESIZE(wval);

so as this field has 1 reserved bit, that could be used in future,
just clear both bits and then OR with the desired value

Signed-off-by: Yegor Yefremov <yegorslists@googlemail.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/tty/vt/vt_ioctl.c: fix KDFONTOP 32bit compatibility layer

commit cbcb8346054073d000ecac324763372d6abd44ac upstream.

KDFONTOP(GET) currently fails with EIO when being run in a 32bit userland
with a 64bit kernel if the font width is not 8.

This is because of the setting of the KD_FONT_FLAG_OLD flag, which makes
con_font_get return EIO in such case.

This flag should *not* be set for KDFONTOP, since it's actually the whole
point of this flag (see comment in con_font_set for instance).

Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Cc: Arthur Taylor <art@ified.ca>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
proc: mem_release() should check mm != NULL

commit 71879d3cb3dd8f2dfdefb252775c1b3ea04a3dd4 upstream.

mem_release() can hit mm == NULL, add the necessary check.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
proc: unify mem_read() and mem_write()

commit 572d34b946bae070debd42db1143034d9687e13f upstream.

No functional changes, cleanup and preparation.

mem_read() and mem_write() are very similar. Move this code into the
new common helper, mem_rw(), which takes the additional "int write"
argument.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
proc: make sure mem_open() doesn't pin the target's memory

commit 6d08f2c7139790c268820a2e590795cb8333181a upstream.

Once /proc/pid/mem is opened, the memory can't be released until
mem_release() even if its owner exits.

Change mem_open() to do atomic_inc(mm_count) + mmput(), this only
pins mm_struct. Change mem_rw() to do atomic_inc_not_zero(mm_count)
before access_remote_vm(), this verifies that this mm is still alive.

I am not sure what should mem_rw() return if atomic_inc_not_zero()
fails. With this patch it returns zero to match the "mm == NULL" case,
may be it should return -EINVAL like it did before e268337d.

Perhaps it makes sense to add the additional fatal_signal_pending()
check into the main loop, to ensure we do not hold this memory if
the target task was oom-killed.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
firewire: ohci: add reset packet quirk for SB Audigy

commit d1bb399ad03c11e792f6dea198d3b1e23061f094 upstream.

The Audigy's SB1394 controller is actually from Texas Instruments
and has the same bus reset packet generation bug, so it needs the
same quirk entry.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
firewire: ohci: disable MSI on Ricoh controllers

commit 320cfa6ce0b3dc794fedfa4bae54c0f65077234d upstream.

The PCIe device

    FireWire (IEEE 1394) [0c00]: Ricoh Co Ltd FireWire Host Controller
    [1180:e832] (prog-if 10 [OHCI])

is unable to access attached FireWire devices when MSI is enabled but
works if MSI is disabled.
http://www.mail-archive.com/alsa-user@lists.sourceforge.net/msg28251.html

Hence add the "disable MSI" quirks flag for this device, or in fact for
safety and simplicity for all current (R5U230, R5U231, R5U240) and
future Ricoh PCIe 1394 controllers.

Reported-by: Stefan Thomas <kontrapunktstefan@googlemail.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
IB/mlx4: pass SMP vendor-specific attribute MADs to firmware

commit a6f7feae6d19e84253918d88b04153af09d3a243 upstream.

In the current code, vendor-specific MADs (e.g with the FDR-10
attribute) are silently dropped by the driver, resulting in timeouts
at the sending side and inability to query/configure the relevant
feature.  However, the ConnectX firmware is able to handle such MADs.
For unsupported attributes, the firmware returns a GET_RESPONSE MAD
containing an error status.

For example, for a FDR-10 node with LID 11:

    # ibstat mlx4_0 1

    CA: 'mlx4_0'
    Port 1:
    State: Active
    Physical state: LinkUp
    Rate: 40 (FDR10)
    Base lid: 11
    LMC: 0
    SM lid: 24
    Capability mask: 0x02514868
    Port GUID: 0x0002c903002e65d1
    Link layer: InfiniBand

Extended Port Query (EPI) vendor mad timeouts before the patch:

    # smpquery MEPI 11 -d

    ibwarn: [4196] smp_query_via: attr 0xff90 mod 0x0 route Lid 11
    ibwarn: [4196] _do_madrpc: retry 1 (timeout 1000 ms)
    ibwarn: [4196] _do_madrpc: retry 2 (timeout 1000 ms)
    ibwarn: [4196] _do_madrpc: timeout after 3 retries, 3000 ms
    ibwarn: [4196] mad_rpc: _do_madrpc failed; dport (Lid 11)
    smpquery: iberror: [pid 4196] main: failed: operation EPI: ext port info query failed

EPI query works OK with the patch:

    # smpquery MEPI 11 -d

    ibwarn: [6548] smp_query_via: attr 0xff90 mod 0x0 route Lid 11
    ibwarn: [6548] mad_rpc: data offs 64 sz 64
    mad data
    0000 0000 0000 0001 0000 0001 0000 0001
    0000 0000 0000 0000 0000 0000 0000 0000
    0000 0000 0000 0000 0000 0000 0000 0000
    0000 0000 0000 0000 0000 0000 0000 0000
    # Ext Port info: Lid 11 port 0
    StateChangeEnable:...............0x00
    LinkSpeedSupported:..............0x01
    LinkSpeedEnabled:................0x01
    LinkSpeedActive:.................0x01

Signed-off-by: Jack Morgenstein <jackm@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Acked-by: Ira Weiny <weiny2@llnl.gov>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
kprobes: fix a memory leak in function pre_handler_kretprobe()

commit 55ca6140e9bb307efc97a9301a4f501de02a6fd6 upstream.

In function pre_handler_kretprobe(), the allocated kretprobe_instance
object will get leaked if the entry_handler callback returns non-zero.
This may cause all the preallocated kretprobe_instance objects exhausted.

This issue can be reproduced by changing
samples/kprobes/kretprobe_example.c to probe "mutex_unlock".  And the fix
is straightforward: just put the allocated kretprobe_instance object back
onto the free_instances list.

[akpm@linux-foundation.org: use raw_spin_lock/unlock]
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Acked-by: Jim Keniston <jkenisto@us.ibm.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
at_hdmac: bugfix for enabling channel irq

commit bda3a47c886664e86ee14eb79e9072b9e341f575 upstream.

commit 463894705e4089d0ff69e7d877312d496ac70e5b deleted redundant
chan_id and chancnt initialization in dma drivers as this is done
in dma_async_device_register().

However, atc_enable_irq() relied on chan_id set before registering
the device, what left only channel 0 functional for this driver.

This patch introduces atc_enable/disable_chan_irq() as a variant
of atc_enable/disable_irq() with the channel as explicit argument.

Signed-off-by: Nikolaus Voss <n.voss@weinmann.de>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mm/filemap_xip.c: fix race condition in xip_file_fault()

commit 99f02ef1f18631eb0a4e0ea0a3d56878dbcb4b90 upstream.

Fix a race condition that shows in conjunction with xip_file_fault() when
two threads of the same user process fault on the same memory page.

In this case, the race winner will install the page table entry and the
unlucky loser will cause an oops: xip_file_fault calls vm_insert_pfn (via
vm_insert_mixed) which drops out at this check:

	retval = -EBUSY;
	if (!pte_none(*pte))
		goto out_unlock;

The resulting -EBUSY return value will trigger a BUG_ON() in
xip_file_fault.

This fix simply considers the fault as fixed in this case, because the
race winner has successfully installed the pte.

[akpm@linux-foundation.org: use conventional (and consistent) comment layout]
Reported-by: David Sadler <dsadler@us.ibm.com>
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Reported-by: Louis Alex Eisner <leisner@cs.ucsd.edu>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mm: compaction: check pfn_valid when entering a new MAX_ORDER_NR_PAGES block during isolation for migration

commit 0bf380bc70ecba68cb4d74dc656cc2fa8c4d801a upstream.

When isolating for migration, migration starts at the start of a zone
which is not necessarily pageblock aligned.  Further, it stops isolating
when COMPACT_CLUSTER_MAX pages are isolated so migrate_pfn is generally
not aligned.  This allows isolate_migratepages() to call pfn_to_page() on
an invalid PFN which can result in a crash.  This was originally reported
against a 3.0-based kernel with the following trace in a crash dump.

PID: 9902   TASK: d47aecd0  CPU: 0   COMMAND: "memcg_process_s"
 #0 [d72d3ad0] crash_kexec at c028cfdb
 #1 [d72d3b24] oops_end at c05c5322
 #2 [d72d3b38] __bad_area_nosemaphore at c0227e60
 #3 [d72d3bec] bad_area at c0227fb6
 #4 [d72d3c00] do_page_fault at c05c72ec
 #5 [d72d3c80] error_code (via page_fault) at c05c47a4
    EAX: 00000000  EBX: 000c0000  ECX: 00000001  EDX: 00000807  EBP: 000c0000
    DS:  007b      ESI: 00000001  ES:  007b      EDI: f3000a80  GS:  6f50
    CS:  0060      EIP: c030b15a  ERR: ffffffff  EFLAGS: 00010002
 #6 [d72d3cb4] isolate_migratepages at c030b15a
 #7 [d72d3d14] zone_watermark_ok at c02d26cb
 #8 [d72d3d2c] compact_zone at c030b8de
 #9 [d72d3d68] compact_zone_order at c030bba1
#10 [d72d3db4] try_to_compact_pages at c030bc84
#11 [d72d3ddc] __alloc_pages_direct_compact at c02d61e7
#12 [d72d3e08] __alloc_pages_slowpath at c02d66c7
#13 [d72d3e78] __alloc_pages_nodemask at c02d6a97
#14 [d72d3eb8] alloc_pages_vma at c030a845
#15 [d72d3ed4] do_huge_pmd_anonymous_page at c03178eb
#16 [d72d3f00] handle_mm_fault at c02f36c6
#17 [d72d3f30] do_page_fault at c05c70ed
#18 [d72d3fb0] error_code (via page_fault) at c05c47a4
    EAX: b71ff000  EBX: 00000001  ECX: 00001600  EDX: 00000431
    DS:  007b      ESI: 08048950  ES:  007b      EDI: bfaa3788
    SS:  007b      ESP: bfaa36e0  EBP: bfaa3828  GS:  6f50
    CS:  0073      EIP: 080487c8  ERR: ffffffff  EFLAGS: 00010202

It was also reported by Herbert van den Bergh against 3.1-based kernel
with the following snippet from the console log.

BUG: unable to handle kernel paging request at 01c00008
IP: [<c0522399>] isolate_migratepages+0x119/0x390
*pdpt = 000000002f7ce001 *pde = 0000000000000000

It is expected that it also affects 3.2.x and current mainline.

The problem is that pfn_valid is only called on the first PFN being
checked and that PFN is not necessarily aligned.  Lets say we have a case
like this

H = MAX_ORDER_NR_PAGES boundary
| = pageblock boundary
m = cc->migrate_pfn
f = cc->free_pfn
o = memory hole

H------|------H------|----m-Hoooooo|ooooooH-f----|------H

The migrate_pfn is just below a memory hole and the free scanner is beyond
the hole.  When isolate_migratepages started, it scans from migrate_pfn to
migrate_pfn+pageblock_nr_pages which is now in a memory hole.  It checks
pfn_valid() on the first PFN but then scans into the hole where there are
not necessarily valid struct pages.

This patch ensures that isolate_migratepages calls pfn_valid when
necessary.

Reported-by: Herbert van den Bergh <herbert.van.den.bergh@oracle.com>
Tested-by: Herbert van den Bergh <herbert.van.den.bergh@oracle.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drm/radeon: Set DESKTOP_HEIGHT register to the framebuffer (not mode) height.

commit 1b61925061660009f5b8047f93c5297e04541273 upstream.

The value of this register is transferred to the V_COUNTER register at the
beginning of vertical blank. V_COUNTER is the reference for VLINE waits and
goes from VIEWPORT_Y_START to VIEWPORT_Y_START+VIEWPORT_HEIGHT during scanout,
so if VIEWPORT_Y_START is not 0, V_COUNTER actually went backwards at the
beginning of vertical blank, and VLINE waits excluding the whole scanout area
could never finish (possibly only if VIEWPORT_Y_START is larger than the length
of vertical blank in scanlines). Setting DESKTOP_HEIGHT to the framebuffer
height should prevent this for any kind of VLINE wait.

Fixes https://bugs.freedesktop.org/show_bug.cgi?id=45329 .

Signed-off-by: Michel Dänzer <michel.daenzer@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drm/nouveau/gem: fix fence_sync race / oops

commit 525895ba388c949aa906f26e3ec5cb1ab041f56b upstream.

Due to a race it was possible for a fence to be destroyed while another
thread was trying to synchronise with it.  If this happened in the fallback
non-semaphore path, it lead to the following oops due to fence->channel
being NULL.

BUG: unable to handle kernel NULL pointer dereference at   (null)
IP: [<fa9632ce>] nouveau_fence_update+0xe/0xe0 [nouveau]
*pde = a649c067
SMP
Modules linked in: fuse nouveau(O) ttm(O) drm_kms_helper(O) drm(O) mxm_wmi video wmi netconsole configfs lockd bnep bluetooth rfkill ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 nf_conntrack_ipv4 nf_defrag_ipv4 xt_state nf_conntrack ip6table_filter ip6_tables snd_hda_codec_realtek snd_hda_intel snd_hda_cobinfmt_misc uinput ata_generic pata_acpi pata_aet2c_algo_bit i2c_core [last unloaded: wmi]

Pid: 2255, comm: gnome-shell Tainted: G           O 3.2.0-0.rc5.git0.1.fc17.i686 #1 System manufacturer System Product Name/M2A-VM
EIP: 0060:[<fa9632ce>] EFLAGS: 00010296 CPU: 1
EIP is at nouveau_fence_update+0xe/0xe0 [nouveau]
EAX: 00000000 EBX: ddfc6dd0 ECX: dd111580 EDX: 00000000
ESI: 00003e80 EDI: dd111580 EBP: dd121d00 ESP: dd121ce8
 DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
Process gnome-shell (pid: 2255, ti=dd120000 task=dd111580 task.ti=dd120000)
Stack:
 7dc86c76 00000000 00003e80 ddfc6dd0 00003e80 dd111580 dd121d0c fa96371f
 00000000 dd121d3c fa963773 dd111580 01000246 000ec53d 00000000 ddfc6dd0
 00001f40 00000000 ddfc6dd0 00000010 dc7df840 dd121d6c fa9639a0 00000000
Call Trace:
 [<fa96371f>] __nouveau_fence_signalled+0x1f/0x30 [nouveau]
 [<fa963773>] __nouveau_fence_wait+0x43/0xd0 [nouveau]
 [<fa9639a0>] nouveau_fence_sync+0x1a0/0x1c0 [nouveau]
 [<fa964046>] validate_list+0x176/0x300 [nouveau]
 [<f7d9c9c0>] ? ttm_bo_mem_put+0x30/0x30 [ttm]
 [<fa964b8a>] nouveau_gem_ioctl_pushbuf+0x48a/0xfd0 [nouveau]
 [<c0406481>] ? die+0x31/0x80
 [<f7c93d98>] drm_ioctl+0x388/0x490 [drm]
 [<c0406481>] ? die+0x31/0x80
 [<fa964700>] ? nouveau_gem_ioctl_new+0x150/0x150 [nouveau]
 [<c0635c7b>] ? file_has_perm+0xcb/0xe0
 [<f7c93a10>] ? drm_copy_field+0x80/0x80 [drm]
 [<c0564f56>] do_vfs_ioctl+0x86/0x5b0
 [<c0406481>] ? die+0x31/0x80
 [<c0635f22>] ? selinux_file_ioctl+0x62/0x130
 [<c0554f30>] ? fget_light+0x30/0x340
 [<c05654ef>] sys_ioctl+0x6f/0x80
 [<c099e3a4>] syscall_call+0x7/0xb
 [<c0406481>] ? die+0x31/0x80
 [<c0406481>] ? die+0x31/0x80

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drm/radeon/kms: disable output polling when suspended

commit 86698c20f71d488b32c49ed4687fb3cf8a88a5ca upstream.

Polling the outputs when the device is suspended can result in erroneous
status updates. Disable output polling during suspend to prevent this
from happening.

Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
sched/rt: Fix task stack corruption under __ARCH_WANT_INTERRUPTS_ON_CTXSW

commit cb297a3e433dbdcf7ad81e0564e7b804c941ff0d upstream.

This issue happens under the following conditions:

 1. preemption is off
 2. __ARCH_WANT_INTERRUPTS_ON_CTXSW is defined
 3. RT scheduling class
 4. SMP system

Sequence is as follows:

 1.suppose current task is A. start schedule()
 2.task A is enqueued pushable task at the entry of schedule()
   __schedule
    prev = rq->curr;
    ...
    put_prev_task
     put_prev_task_rt
      enqueue_pushable_task
 4.pick the task B as next task.
   next = pick_next_task(rq);
 3.rq->curr set to task B and context_switch is started.
   rq->curr = next;
 4.At the entry of context_swtich, release this cpu's rq->lock.
   context_switch
    prepare_task_switch
     prepare_lock_switch
      raw_spin_unlock_irq(&rq->lock);
 5.Shortly after rq->lock is released, interrupt is occurred and start IRQ context
 6.try_to_wake_up() which called by ISR acquires rq->lock
    try_to_wake_up
     ttwu_remote
      rq = __task_rq_lock(p)
      ttwu_do_wakeup(rq, p, wake_flags);
        task_woken_rt
 7.push_rt_task picks the task A which is enqueued before.
   task_woken_rt
    push_rt_tasks(rq)
     next_task = pick_next_pushable_task(rq)
 8.At find_lock_lowest_rq(), If double_lock_balance() returns 0,
   lowest_rq can be the remote rq.
  (But,If preemption is on, double_lock_balance always return 1 and it
   does't happen.)
   push_rt_task
    find_lock_lowest_rq
     if (double_lock_balance(rq, lowest_rq))..
 9.find_lock_lowest_rq return the available rq. task A is migrated to
   the remote cpu/rq.
   push_rt_task
    ...
    deactivate_task(rq, next_task, 0);
    set_task_cpu(next_task, lowest_rq->cpu);
    activate_task(lowest_rq, next_task, 0);
 10. But, task A is on irq context at this cpu.
     So, task A is scheduled by two cpus at the same time until restore from IRQ.
     Task A's stack is corrupted.

To fix it, don't migrate an RT task if it's still running.

Signed-off-by: Chanho Min <chanho.min@lge.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/CAOAMb1BHA=5fm7KTewYyke6u-8DP0iUuJMpgQw54vNeXFsGpoQ@mail.gmail.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ASoC: Ensure we generate a driver name

commit f0e8ed858edb327802ee65fd695cc1538286226f upstream.

Commit 873bd4c (ASoC: Don't set invalid name string to snd_card->driver
field) broke generation of a driver name for all ASoC cards relying on the
automatic generation of one. Fix this by using the old default with spaces
replaced by underscores.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>