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  1. 31 May, 2015 4 commits
    • Vitaly Kuznetsov's avatar
      Drivers: hv: balloon: check if ha_region_mutex was acquired in MEM_CANCEL_ONLINE case · 4e4bd36f
      Vitaly Kuznetsov authored 
      Memory notifiers are being executed in a sequential order and when one of
them fails returning something different from NOTIFY_OK the remainder of
the notification chain is not being executed. When a memory block is being
onlined in online_pages() we do memory_notify(MEM_GOING_ONLINE, ) and if
one of the notifiers in the chain fails we end up doing
memory_notify(MEM_CANCEL_ONLINE, ) so it is possible for a notifier to see
MEM_CANCEL_ONLINE without seeing the corresponding MEM_GOING_ONLINE event.
E.g. when CONFIG_KASAN is enabled the kasan_mem_notifier() is being used
to prevent memory hotplug, it returns NOTIFY_BAD for all MEM_GOING_ONLINE
events. As kasan_mem_notifier() comes before the hv_memory_notifier() in
the notification chain we don't see the MEM_GOING_ONLINE event and we do
not take the ha_region_mutex. We, however, see the MEM_CANCEL_ONLINE event
and unconditionally try to release the lock, the following is observed:

[  110.850927] =====================================
[  110.850927] [ BUG: bad unlock balance detected! ]
[  110.850927] 4.1.0-rc3_bugxxxxxxx_test_xxxx #595 Not tainted
[  110.850927] -------------------------------------
[  110.850927] systemd-udevd/920 is trying to release lock
(&dm_device.ha_region_mutex) at:
[  110.850927] [<ffffffff81acda0e>] mutex_unlock+0xe/0x10
[  110.850927] but there are no more locks to release!

At the same time we can have the ha_region_mutex taken when we get the
MEM_CANCEL_ONLINE event in case one of the memory notifiers after the
hv_memory_notifier() in the notification chain failed so we need to add
the mutex_is_locked() check. In case of MEM_ONLINE we are always supposed
to have the mutex locked.
Signed-off-by: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: default avatarK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      4e4bd36f
    • Keith Mange's avatar
      Drivers: hv: vmbus:Update preferred vmbus protocol version to windows 10. · 6c4e5f9c
      Keith Mange authored 
      Add support for Windows 10.
Signed-off-by: default avatarKeith Mange <keith.mange@microsoft.com>
Signed-off-by: default avatarK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      6c4e5f9c
    • Vladimir Zapolskiy's avatar
      char: misc: restore MISC_DYNAMIC_MINOR on device_create() failure · b575f712
      Vladimir Zapolskiy authored 
      On attempt to register a dynamic minor misc device its minor number is
updated to a virtual minor number prior to device_create() call,
however on error path misc->minor == MISC_DYNAMIC_MINOR is not
restored.

Following the rule of thumb that a function returning an error must
not change the state of the caller, assign MISC_DYNAMIC_MINOR back.

The problem is met in a sutuation, when subsys_initcall(misc_init) is
not yet called and misc_class is not created, but misc_register()
modifies statically defined ".minor = MISC_DYNAMIC_MINOR", therefore
implicitly changing the client's logic on next attempt (e.g. retrying
from deferred list) to register a misc device, whose minor number is
converted from dynamic to some unknown static one.
Signed-off-by: default avatarVladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      b575f712
    • Greg Kroah-Hartman's avatar
      mei: fix up uuid matching · b144ce2d
      Greg Kroah-Hartman authored 
      A previous commit, c93b76b3 ("mei: bus: report also uuid in module
alias") caused a build error as I missed applying a needed patch to add
some macros to uapi/linux/uuid.h.  Instead of those additional macros,
change the mei code to use the existing uuid structure directly.

Fixes: c93b76b3
Cc: Tomas Winkler <tomas.winkler@intel.com>
Cc: Samuel Ortiz <sameo@linux.intel.com>
Reported-by: default avatarStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      b144ce2d
  3. 24 May, 2015 36 commits
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