pidns: remove recursion from free_pid_ns()

free_pid_ns() operates in a recursive fashion:

free_pid_ns(parent)
  put_pid_ns(parent)
    kref_put(&ns->kref, free_pid_ns);
      free_pid_ns

thus if there was a huge nesting of namespaces the userspace may trigger
avalanche calling of free_pid_ns leading to kernel stack exhausting and a
panic eventually.

This patch turns the recursion into an iterative loop.

Based on a patch by Andrew Vagin.

[akpm@linux-foundation.org: export put_pid_ns() to modules]
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Andrew Vagin <avagin@openvz.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
firmware/memmap: avoid type conflicts with the generic memmap_init()

Fix this build error:

  drivers/firmware/memmap.c:240:19: error: conflicting types for 'memmap_init'
  arch/ia64/include/asm/pgtable.h:565:17: note: previous declaration of 'memmap_init' was here

Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Cc: Bernhard Walle <bwalle@suse.de>
Cc: Glauber Costa <glommer@parallels.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm: compaction: correct the nr_strict va isolated check for CMA

Thierry reported that the "iron out" patch for isolate_freepages_block()
had problems due to the strict check being too strict with "mm:
compaction: Iron out isolate_freepages_block() and
isolate_freepages_range() -fix1".  It's possible that more pages than
necessary are isolated but the check still fails and I missed that this
fix was not picked up before RC1.  This same problem has been identified
in 3.7-RC1 by Tony Prisk and should be addressed by the following patch.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Tested-by: Tony Prisk <linux@prisktech.co.nz>
Reported-by: Thierry Reding <thierry.reding@avionic-design.de>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Richard Davies <richard@arachsys.com>
Cc: Shaohua Li <shli@kernel.org>
Cc: Avi Kivity <avi@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
lib/dma-debug.c: fix __hash_bucket_find()

If there is only one match, the unique matched entry should be returned.

Without the fix, the upcoming dma debug interfaces ("dma-debug: new
interfaces to debug dma mapping errors") can't work reliably because
only device and dma_addr are passed to dma_mapping_error().

Signed-off-by: Ming Lei <ming.lei@canonical.com>
Reported-by: Wu Fengguang <fengguang.wu@intel.com>
Cc: Joerg Roedel <joerg.roedel@amd.com>
Tested-by: Shuah Khan <shuah.khan@hp.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Jakub Kicinski <kubakici@wp.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge branch 'akpm' (Fixes from Andrew)

Merge misc fixes from Andrew Morton:
 "Seven fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (7 patches)
  lib/dma-debug.c: fix __hash_bucket_find()
  mm: compaction: correct the nr_strict va isolated check for CMA
  firmware/memmap: avoid type conflicts with the generic memmap_init()
  pidns: remove recursion from free_pid_ns()
  drivers/video/backlight/lm3639_bl.c: return proper error in lm3639_bled_mode_store() error paths
  kernel/sys.c: fix stack memory content leak via UNAME26
  linux/coredump.h needs asm/siginfo.h
Revert "cgroup: Drop task_lock(parent) on cgroup_fork()"

This reverts commit 7e381b0eb1e1a9805c37335562e8dc02e7d7848c.

The commit incorrectly assumed that fork path always performed
threadgroup_change_begin/end() and depended on that for
synchronization against task exit and cgroup migration paths instead
of explicitly grabbing task_lock().

threadgroup_change is not locked when forking a new process (as
opposed to a new thread in the same process) and even if it were it
wouldn't be effective as different processes use different threadgroup
locks.

Revert the incorrect optimization.

Signed-off-by: Tejun Heo <tj@kernel.org>
LKML-Reference: <20121008020000.GB2575@localhost>
Acked-by: Li Zefan <lizefan@huawei.com>
Bitterly-Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: stable@vger.kernel.org
Revert "cgroup: Remove task_lock() from cgroup_post_fork()"

This reverts commit 7e3aa30ac8c904a706518b725c451bb486daaae9.

The commit incorrectly assumed that fork path always performed
threadgroup_change_begin/end() and depended on that for
synchronization against task exit and cgroup migration paths instead
of explicitly grabbing task_lock().

threadgroup_change is not locked when forking a new process (as
opposed to a new thread in the same process) and even if it were it
wouldn't be effective as different processes use different threadgroup
locks.

Revert the incorrect optimization.

Signed-off-by: Tejun Heo <tj@kernel.org>
LKML-Reference: <20121008020000.GB2575@localhost>
Acked-by: Li Zefan <lizefan@huawei.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: stable@vger.kernel.org
Merge branch 'x86/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull miscellaneous x86 fixes from Peter Anvin:
 "The biggest ones are fixing suspend/resume breakage on 32 bits, and an
  interrim fix for mapping over holes that allows AMD kit with more than
  1 TB.

  A final solution for the latter is in the works, but involves some
  fairly invasive changes that will probably mean it will only be
  appropriate for 3.8."

* 'x86/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, MCE: Remove bios_cmci_threshold sysfs attribute
  x86, amd, mce: Avoid NULL pointer reference on CPU northbridge lookup
  x86: Exclude E820_RESERVED regions and memory holes above 4 GB from direct mapping.
  x86/cache_info: Use ARRAY_SIZE() in amd_l3_attrs()
  x86/reboot: Remove quirk entry for SBC FITPC
  x86, suspend: Correct the restore of CR4, EFER; skip computing EFLAGS.ID
hold task->mempolicy while numa_maps scans.

  /proc/<pid>/numa_maps scans vma and show mempolicy under
  mmap_sem. It sometimes accesses task->mempolicy which can
  be freed without mmap_sem and numa_maps can show some
  garbage while scanning.

This patch tries to take reference count of task->mempolicy at reading
numa_maps before calling get_vma_policy(). By this, task->mempolicy
will not be freed until numa_maps reaches its end.

V2->v3
  -  updated comments to be more verbose.
  -  removed task_lock() in numa_maps code.
V1->V2
  -  access task->mempolicy only once and remember it.  Becase kernel/exit.c
     can overwrite it.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge branch 'testing/driver-warnings' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc into fixes

A collection of warning fixes on non-ARM code from Arnd Bergmann:

* 'testing/driver-warnings' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  ARM: s3c: mark s3c2440_clk_add as __init_refok
  spi/s3c64xx: use correct dma_transfer_direction type
  pcmcia: sharpsl: don't discard sharpsl_pcmcia_ops
  USB: EHCI: mark ehci_orion_conf_mbus_windows __devinit
  mm/slob: use min_t() to compare ARCH_SLAB_MINALIGN
  SCSI: ARM: make fas216_dumpinfo function conditional
  SCSI: ARM: ncr5380/oak uses no interrupts
MODSIGN: perlify sign-file and merge in x509keyid

Turn sign-file into perl and merge in x509keyid.  The latter doesn't
need to be a separate script as it doesn't actually need to work out the
SHA1 sum of the X.509 certificate itself, since it can get that from the
X.509 certificate.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
MODSIGN: Cleanup .gitignore

The module build process no longer creates intermediate files for module
signing, so remove them from .gitignore.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge tag 'kirkwood_fixes_for_v3.7' of git://git.infradead.org/users/jcooper/linux into fixes

From Jason Cooper:
 - improve #ifdef logic to prevent linker errors with CACHE_FEROCEON_L2
 - lsxl board dts fixes

* tag 'kirkwood_fixes_for_v3.7' of git://git.infradead.org/users/jcooper/linux:
  ARM: kirkwood: fix buttons on lsxl boards
  ARM: kirkwood: fix LEDs names for lsxl boards
  ARM: Kirkwood: fix disabling CACHE_FEROCEON_L2
MODSIGN: Move the magic string to the end of a module and eliminate the search

Emit the magic string that indicates a module has a signature after the
signature data instead of before it.  This allows module_sig_check() to
be made simpler and faster by the elimination of the search for the
magic string.  Instead we just need to do a single memcmp().

This works because at the end of the signature data there is the
fixed-length signature information block.  This block then falls
immediately prior to the magic number.

From the contents of the information block, it is trivial to calculate
the size of the signature data and thus the size of the actual module
data.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc

Pull ARM soc fixes from Olof Johansson:
 "A set of fixes and some minor cleanups for -rc2:

   - A series from Arnd that fixes warnings in drivers and other code
     included by ARM defconfigs.  Most have been acked by corresponding
     maintainers (and seem quite hard to argue not picking up anyway in
     the few exception cases).
   - A few misc patches from the list for integrator/vt8500/i.MX
   - A batch of fixes to OMAP platforms, fixing:
     - boot problems on beaglebone,
     - regression fixes for local timers
     - clockdomain locking fixes
     - a few boot/sparse warnings
   - For Tegra:
     - Clock rate calculation overflow fix
     - Revert a change that removed timer clocks and a fix for symbol
       name clashes
   - For Renesas:
     - IO accessor / annotation cleanups to remove warnings
   - For Kirkwood/Dove/mvebu:
     - Fixes for device trees for Dove (some minor cleanups, some fixes)
     - Fixes for the mvebu gpio driver
     - Fix build problem for Feroceon due to missing ifdefs
     - Fix lsxl DTS files"

* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (31 commits)
  ARM: kirkwood: fix buttons on lsxl boards
  ARM: kirkwood: fix LEDs names for lsxl boards
  ARM: Kirkwood: fix disabling CACHE_FEROCEON_L2
  gpio: mvebu: Add missing breaks in mvebu_gpio_irq_set_type
  ARM: dove: Add crypto engine to DT
  ARM: dove: Remove watchdog from DT
  ARM: dove: Restructure SoC device tree descriptor
  ARM: dove: Fix clock names of sata and gbe
  ARM: dove: Fix tauros2 device tree init
  ARM: dove: Add pcie clock support
  ARM: OMAP2+: Allow kernel to boot even if GPMC fails to reserve memory
  ARM: OMAP: clockdomain: Fix locking on _clkdm_clk_hwmod_enable / disable
  ARM: s3c: mark s3c2440_clk_add as __init_refok
  spi/s3c64xx: use correct dma_transfer_direction type
  ARM: OMAP4: devices: fixup OMAP4 DMIC platform device error message
  ARM: OMAP2+: clock data: Add dev-id for the omap-gpmc dummy fck
  ARM: OMAP: resolve sparse warning concerning debug_card_init()
  ARM: OMAP4: Fix twd_local_timer_register regression
  ARM: tegra: add tegra_timer clock
  ARM: tegra: rename tegra system timer
  ...
Merge tag 'perf-urgent-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent

Pull perf/urgent fixes from Arnaldo Carvalho de Melo:

* The python binding needs to link with libtraceevent and to initialize
  the 'page_size' variable so that mmaping works again.

* The callchain folding character that appears on the TUI just before
  the overhead had disappeared due to recent changes, add it back.

* Intel PEBS in VT-x context uses the DS address as a guest linear address,
  even though its programmed by the host as a host linear address. This either
  results in guest memory corruption and or the hardware faulting and 'crashing'
  the virtual machine.  Therefore we have to disable PEBS on VT-x enter and
  re-enable on VT-x exit, enforcing a strict exclude_guest.

  Kernel side enforcement fix by Peter Zijlstra, tooling side fix by David Ahern.

* Fix build on sparc due to UAPI, fix from David Miller.

* Fixes for the srclike sort key for unresolved symbols and when processing
  samples in JITted code, where we don't have an ELF file, just an special
  symbol table, fixes from Namhyung Kim.

* Fix some leaks in libtraceevent, from Steven Rostedt.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
perf python: Properly link with libtraceevent

Namhyung Kim reported that the build fails with:

  GEN python/perf.so
  gcc: error: python_ext_build/tmp//../../libtraceevent.a: No such file or directory
  error: command 'gcc' failed with exit status 1
  cp: cannot stat `python_ext_build/lib/perf.so': No such file or directory
  make: *** [python/perf.so] Error 1

We need to propagate the TE_PATH variable to the setup.py file.

Reported-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Link: http://lkml.kernel.org/n/tip-8umiPbm4sxpknKivbjgykhut@git.kernel.org
[ Fixed superfluous variable build error. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull perf fixes from Ingo Molnar:
 "Assorted small fixes"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf python: Properly link with libtraceevent
  perf hists browser: Add back callchain folding symbol
  perf tools: Fix build on sparc.
  perf python: Link with libtraceevent
  perf python: Initialize 'page_size' variable
  tools lib traceevent: Fix missed freeing of subargs in free_arg() in filter
  lib tools traceevent: Add back pevent assignment in __pevent_parse_format()
  perf hists browser: Fix off-by-two bug on the first column
  perf tools: Remove warnings on JIT samples for srcline sort key
  perf tools: Fix segfault when using srcline sort key
  perf: Require exclude_guest to use PEBS - kernel side enforcement
  perf tool: Precise mode requires exclude_guest
use clamp_t in UNAME26 fix

The min/max call needed to have explicit types on some architectures
(e.g. mn10300). Use clamp_t instead to avoid the warning:

  kernel/sys.c: In function 'override_release':
  kernel/sys.c:1287:10: warning: comparison of distinct pointer types lacks a cast [enabled by default]

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
perf/x86: Disable uncore on virtualized CPUs

Initializing uncore PMU on virtualized CPU may hang the kernel.
This is because kvm does not emulate the entire hardware. Thers
are lots of uncore related MSRs, making kvm enumerate them all
is a non-trival task. So just disable uncore on virtualized CPU.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Tested-by: Pekka Enberg <penberg@kernel.org>
Cc: a.p.zijlstra@chello.nl
Cc: eranian@google.com
Cc: andi@firstfloor.org
Cc: avi@redhat.com
Link: http://lkml.kernel.org/r/1345540117-14164-1-git-send-email-zheng.z.yan@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>