linux-toradex.git/Documentation, branch v3.15.3

mm/memory-failure.c: support use of a dedicated thread to handle SIGBUS(BUS_MCEERR_AO)

2014-07-01T03:13:55+00:00

commit 3ba08129e38437561df44c36b7ea9081185d5333 upstream.

Currently memory error handler handles action optional errors in the
deferred manner by default.  And if a recovery aware application wants
to handle it immediately, it can do it by setting PF_MCE_EARLY flag.
However, such signal can be sent only to the main thread, so it's
problematic if the application wants to have a dedicated thread to
handler such signals.

So this patch adds dedicated thread support to memory error handler.  We
have PF_MCE_EARLY flags for each thread separately, so with this patch
AO signal is sent to the thread with PF_MCE_EARLY flag set, not the main
thread.  If you want to implement a dedicated thread, you call prctl()
to set PF_MCE_EARLY on the thread.

Memory error handler collects processes to be killed, so this patch lets
it check PF_MCE_EARLY flag on each thread in the collecting routines.

No behavioral change for all non-early kill cases.

Tony said:

: The old behavior was crazy - someone with a multithreaded process might
: well expect that if they call prctl(PF_MCE_EARLY) in just one thread, then
: that thread would see the SIGBUS with si_code = BUS_MCEERR_A0 - even if
: that thread wasn't the main thread for the process.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Naoya Horiguchi 
Reviewed-by: Tony Luck 
Cc: Kamil Iskra 
Cc: Andi Kleen 
Cc: Borislav Petkov 
Cc: Chen Gong 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

ima: audit log files opened with O_DIRECT flag

2014-06-26T19:17:33+00:00

commit f9b2a735bdddf836214b5dca74f6ca7712e5a08c upstream.

Files are measured or appraised based on the IMA policy.  When a
file, in policy, is opened with the O_DIRECT flag, a deadlock
occurs.

The first attempt at resolving this lockdep temporarily removed the
O_DIRECT flag and restored it, after calculating the hash.  The
second attempt introduced the O_DIRECT_HAVELOCK flag. Based on this
flag, do_blockdev_direct_IO() would skip taking the i_mutex a second
time.  The third attempt, by Dmitry Kasatkin, resolves the i_mutex
locking issue, by re-introducing the IMA mutex, but uncovered
another problem.  Reading a file with O_DIRECT flag set, writes
directly to userspace pages.  A second patch allocates a user-space
like memory.  This works for all IMA hooks, except ima_file_free(),
which is called on __fput() to recalculate the file hash.

Until this last issue is addressed, do not 'collect' the
measurement for measuring, appraising, or auditing files opened
with the O_DIRECT flag set.  Based on policy, permit or deny file
access.  This patch defines a new IMA policy rule option named
'permit_directio'.  Policy rules could be defined, based on LSM
or other criteria, to permit specific applications to open files
with the O_DIRECT flag set.

Changelog v1:
- permit or deny file access based IMA policy rules

Signed-off-by: Mimi Zohar 
Acked-by: Dmitry Kasatkin 
Signed-off-by: Greg Kroah-Hartman

Merge tag 'firewire-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394

2014-05-30T19:06:15+00:00

Pull firewire fix from Stefan Richter:
 "A regression fix for the IEEE 1394 subsystem: re-enable IRQ-based
  asynchronous request reception at addresses below 128 TB"

* tag 'firewire-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394:
  firewire: revert to 4 GB RDMA, fix protocols using Memory Space

Merge tag 'dm-3.15-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

2014-05-30T19:04:56+00:00

Pull device-mapper fixes from Mike Snitzer:
 "A dm-cache stable fix to split discards on cache block boundaries
  because dm-cache cannot yet handle discards that span cache blocks.

  Really fix a dm-mpath LOCKDEP warning that was introduced in -rc1.

  Add a 'no_space_timeout' control to dm-thinp to restore the ability to
  queue IO indefinitely when no data space is available.  This fixes a
  change in behavior that was introduced in -rc6 where the timeout
  couldn't be disabled"

* tag 'dm-3.15-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm mpath: really fix lockdep warning
  dm cache: always split discards on cache block boundaries
  dm thin: add 'no_space_timeout' dm-thin-pool module param

firewire: revert to 4 GB RDMA, fix protocols using Memory Space

2014-05-29T13:50:30+00:00

Undo a feature introduced in v3.14 by commit fcd46b34425d
"firewire: Enable remote DMA above 4 GB".  That change raised the
minimum address at which protocol drivers and user programs can register
for request reception from 0x0001'0000'0000 to 0x8000'0000'0000.
It turned out that at least one vendor-specific protocol exists which
uses lower addresses:  https://bugzilla.kernel.org/show_bug.cgi?id=76921

For the time being, revert most of commit fcd46b34425d so that affected
protocols work like with kernel v3.13 and before.  Just keep the valid
documentation parts from the regressing commit, and the ability to
identify controllers which could be programmed to accept >32 bit
physical DMA addresses.  The rest of fcd46b34425d should probably be
brought back as an optional instead of default feature.

Reported-by: Fabien Spindler 
Cc:  # 3.14+
Signed-off-by: Stefan Richter

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

2014-05-28T15:08:03+00:00

Pull kvm fixes from Paolo Bonzini:
 "Small fixes for x86, slightly larger fixes for PPC, and a forgotten
  s390 patch.  The PPC fixes are important because they fix breakage
  that is new in 3.15"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: s390: announce irqfd capability
  KVM: x86: disable master clock if TSC is reset during suspend
  KVM: vmx: disable APIC virtualization in nested guests
  KVM guest: Make pv trampoline code executable
  KVM: PPC: Book3S: ifdef on CONFIG_KVM_BOOK3S_32_HANDLER for 32bit
  KVM: PPC: Book3S HV: Add missing code for transaction reclaim on guest exit
  KVM: PPC: Book3S: HV: make _PAGE_NUMA take effect

Merge branch 'rdunlap' (patches from Randy Dunlap)

2014-05-25T19:39:08+00:00

Merge documentation fixes from Randy Dunlap.

* emailed patches from Randy Dunlap :
  Documentation: update /proc/stat "intr" count summary
  Documentation: update java sample wrapper for java 7
  Documentation: update thunderbird email client settings
  Documentation: fix typos in drm docbook

Documentation: update /proc/stat "intr" count summary

2014-05-25T19:39:00+00:00

The sum at the beginning of line "intr" includes also unnumbered
interrupts.  It implies that the sum at the beginning isn't the sum
of the remainder of the line, not even an estimation.

Fixed the documentation to mention that.

This behaviour was added to /proc/stat in commit a2eddfa95919 ("x86:
make /proc/stat account for all interrupts")

Signed-off-by: Jan Moskyto Matejka 
Signed-off-by: Randy Dunlap 
Signed-off-by: Linus Torvalds

Documentation: update java sample wrapper for java 7

2014-05-25T19:39:00+00:00

The sample wrapper currently fails on some Java 7 .class files.  This
updates the wrapper to properly handle those files.

Signed-off-by: Jonathan Callen 
Signed-off-by: Randy Dunlap 
Signed-off-by: Linus Torvalds

Documentation: update thunderbird email client settings

2014-05-25T19:39:00+00:00

Added setting to email-clients that is easier to read and is easier to
setup thunderbird.  Removed config settings and added GUI settings.

Signed-off-by: Paul McQuade 
Signed-off-by: Randy Dunlap 
Signed-off-by: Linus Torvalds