1. 12 10月, 2015 1 次提交
    • T
      efi: Add "efi_fake_mem" boot option · 0f96a99d
      Taku Izumi 提交于
      This patch introduces new boot option named "efi_fake_mem".
      By specifying this parameter, you can add arbitrary attribute
      to specific memory range.
      This is useful for debugging of Address Range Mirroring feature.
      
      For example, if "efi_fake_mem=2G@4G:0x10000,2G@0x10a0000000:0x10000"
      is specified, the original (firmware provided) EFI memmap will be
      updated so that the specified memory regions have
      EFI_MEMORY_MORE_RELIABLE attribute (0x10000):
      
       <original>
         efi: mem36: [Conventional Memory|  |  |  |  |  |   |WB|WT|WC|UC] range=[0x0000000100000000-0x00000020a0000000) (129536MB)
      
       <updated>
         efi: mem36: [Conventional Memory|  |MR|  |  |  |   |WB|WT|WC|UC] range=[0x0000000100000000-0x0000000180000000) (2048MB)
         efi: mem37: [Conventional Memory|  |  |  |  |  |   |WB|WT|WC|UC] range=[0x0000000180000000-0x00000010a0000000) (61952MB)
         efi: mem38: [Conventional Memory|  |MR|  |  |  |   |WB|WT|WC|UC] range=[0x00000010a0000000-0x0000001120000000) (2048MB)
         efi: mem39: [Conventional Memory|  |  |  |  |  |   |WB|WT|WC|UC] range=[0x0000001120000000-0x00000020a0000000) (63488MB)
      
      And you will find that the following message is output:
      
         efi: Memory: 4096M/131455M mirrored memory
      Signed-off-by: NTaku Izumi <izumi.taku@jp.fujitsu.com>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Xishi Qiu <qiuxishi@huawei.com>
      Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
      Signed-off-by: NMatt Fleming <matt.fleming@intel.com>
      0f96a99d
  2. 03 7月, 2015 1 次提交
    • R
      ACPI / init: Make it possible to override _REV · 18d78b64
      Rafael J. Wysocki 提交于
      The platform firmware on some systems expects Linux to return "5" as
      the supported ACPI revision which makes it expose system configuration
      information in a special way.
      
      For example, based on what ACPI exports as the supported revision,
      Dell XPS 13 (2015) configures its audio device to either work in HDA
      mode or in I2S mode, where the former is supposed to be used on Linux
      until the latter is fully supported (in the kernel as well as in user
      space).
      
      Since ACPI 6 mandates that _REV should return "2" if ACPI 2 or later
      is supported by the OS, a subsequent change will make that happen, so
      make it possible to override that on systems where "5" is expected to
      be returned for Linux to work correctly one them (such as the Dell
      machine mentioned above).
      Original-by: NDominik Brodowski <linux@dominikbrodowski.net>
      Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
      18d78b64
  3. 23 6月, 2015 1 次提交
  4. 16 6月, 2015 1 次提交
    • M
      ima: update builtin policies · 24fd03c8
      Mimi Zohar 提交于
      This patch defines a builtin measurement policy "tcb", similar to the
      existing "ima_tcb", but with additional rules to also measure files
      based on the effective uid and to measure files opened with the "read"
      mode bit set (eg. read, read-write).
      
      Changing the builtin "ima_tcb" policy could potentially break existing
      users.  Instead of defining a new separate boot command line option each
      time the builtin measurement policy is modified, this patch defines a
      single generic boot command line option "ima_policy=" to specify the
      builtin policy and deprecates the use of the builtin ima_tcb policy.
      
      [The "ima_policy=" boot command line option is based on Roberto Sassu's
      "ima: added new policy type exec" patch.]
      Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>
      Signed-off-by: NDr. Greg Wettstein <gw@idfusion.org>
      Cc: stable@vger.kernel.org
      24fd03c8
  5. 12 6月, 2015 1 次提交
    • D
      iommu/vt-d: Only enable extended context tables if PASID is supported · c83b2f20
      David Woodhouse 提交于
      Although the extended tables are theoretically a completely orthogonal
      feature to PASID and anything else that *uses* the newly-available bits,
      some of the early hardware has problems even when all we do is enable
      them and use only the same bits that were in the old context tables.
      
      For now, there's no motivation to support extended tables unless we're
      going to use PASID support to do SVM. So just don't use them unless
      PASID support is advertised too. Also add a command-line bailout just in
      case later chips also have issues.
      
      The equivalent problem for PASID support has already been fixed with the
      upcoming VT-d spec update and commit bd00c606 ("iommu/vt-d: Change
      PASID support to bit 40 of Extended Capability Register"), because the
      problematic platforms use the old definition of the PASID-capable bit,
      which is now marked as reserved and meaningless.
      
      So with this change, we'll magically start using ECS again only when we
      see the new hardware advertising "hey, we have PASID support and we
      actually tested it this time" on bit 40.
      
      The VT-d hardware architect has promised that we are not going to have
      any reason to support ECS *without* PASID any time soon, and he'll make
      sure he checks with us before changing that.
      
      In the future, if hypothetical new features also use new bits in the
      context tables and can be seen on implementations *without* PASID support,
      we might need to add their feature bits to the ecs_enabled() macro.
      Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>
      c83b2f20
  6. 09 6月, 2015 1 次提交
    • D
      x86/mpx: Introduce a boot-time disable flag · 8c3641e9
      Dave Hansen 提交于
      MPX has the _potential_ to cause some issues.  Say part of your
      init system tried to protect one of its components from buffer
      overflows with MPX.  If there were a false positive, it's
      possible that MPX could keep a system from booting.
      
      MPX could also potentially cause performance issues since it is
      present in hot paths like the unmap path.
      
      Allow it to be disabled at boot time.
      Signed-off-by: NDave Hansen <dave.hansen@linux.intel.com>
      Reviewed-by: Thomas Gleixner <tglx@linutronix.de
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Dave Hansen <dave@sr71.net>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Link: http://lkml.kernel.org/r/20150607183702.2E8B77AB@viggo.jf.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      8c3641e9
  7. 01 6月, 2015 1 次提交
  8. 28 5月, 2015 4 次提交
    • P
      rcutorture: Allow negative values of nreaders to oversubscribe · 3838cc18
      Paul E. McKenney 提交于
      By default, with rcutorture.nreaders equal to -1, rcutorture provisions
      N-1 reader kthreads, where N is the number of CPUs.  This avoids
      rcutorture-induced stalls, but also avoids heavier levels of torture.
      This commit therefore allows negative values of rcutorture.nreaders
      to specify larger numbers of reader kthreads, so that for example
      rcutorture.nreaders=-2 provisions N kthreads and rcutorture.nreaders=-5
      provisions N+3 kthreads.
      Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      [ paulmck: Update documentation, as suggested by Josh Triplett. ]
      3838cc18
    • P
      rcu: Enable diagnostic dump of rcu_node combining tree · a3dc2948
      Paul E. McKenney 提交于
      The purpose of this commit is to make it easier to verify that RCU's
      combining tree is set up correctly, which is useful to have when making
      changes in how that tree is initialized.
      Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      Reviewed-by: NPranith Kumar <bobby.prani@gmail.com>
      [ paulmck: Fold fix found by Fengguang's 0-day test robot. ]
      a3dc2948
    • P
      rcu: Convert CONFIG_RCU_FANOUT_EXACT to boot parameter · 7fa27001
      Paul E. McKenney 提交于
      The CONFIG_RCU_FANOUT_EXACT Kconfig parameter is used primarily (and
      perhaps only) by rcutorture to verify that RCU works correctly in specific
      rcu_node combining-tree configurations.  It therefore does not make
      much sense have this as a question to people attempting to configure
      their kernels.  So this commit creates an rcutree.rcu_fanout_exact=
      boot parameter that rcutorture can use, and eliminates the original
      CONFIG_RCU_FANOUT_EXACT Kconfig parameter.
      Reported-by: NIngo Molnar <mingo@kernel.org>
      Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      Reviewed-by: NPranith Kumar <bobby.prani@gmail.com>
      7fa27001
    • P
      rcu: Provide diagnostic option to slow down grace-period scans · 0f41c0dd
      Paul E. McKenney 提交于
      Grace-period scans of the rcu_node combining tree normally
      proceed quite quickly, so that it is very difficult to reproduce
      races against them.  This commit therefore allows grace-period
      pre-initialization and cleanup to be artificially slowed down,
      increasing race-reproduction probability.  A pair of pairs of new
      Kconfig parameters are provided, RCU_TORTURE_TEST_SLOW_PREINIT to
      enable the slowing down of propagating CPU-hotplug changes up the
      combining tree along with RCU_TORTURE_TEST_SLOW_PREINIT_DELAY to
      specify the delay in jiffies, and RCU_TORTURE_TEST_SLOW_CLEANUP
      to enable the slowing down of the end-of-grace-period cleanup scan
      along with RCU_TORTURE_TEST_SLOW_CLEANUP_DELAY to specify the delay
      in jiffies.  Boot-time parameters named rcutree.gp_preinit_delay and
      rcutree.gp_cleanup_delay allow these delays to be specified at boot time.
      Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      0f41c0dd
  9. 20 5月, 2015 1 次提交
  10. 16 5月, 2015 1 次提交
  11. 15 5月, 2015 1 次提交
  12. 13 5月, 2015 1 次提交
  13. 12 5月, 2015 1 次提交
  14. 05 5月, 2015 1 次提交
  15. 28 4月, 2015 1 次提交
  16. 15 4月, 2015 3 次提交
    • V
      Documentation: update arch list in the 'memtest' entry · e4b0db72
      Vladimir Murzin 提交于
      Since arm64/arm support memtest command line option update the "memtest"
      entry.
      Signed-off-by: NVladimir Murzin <vladimir.murzin@arm.com>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Mark Rutland <mark.rutland@arm.com>
      Cc: Russell King <rmk@arm.linux.org.uk>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Will Deacon <will.deacon@arm.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      e4b0db72
    • T
      lib/ioremap.c: add huge I/O map capability interfaces · 0ddab1d2
      Toshi Kani 提交于
      Add ioremap_pud_enabled() and ioremap_pmd_enabled(), which return 1 when
      I/O mappings with pud/pmd are enabled on the kernel.
      
      ioremap_huge_init() calls arch_ioremap_pud_supported() and
      arch_ioremap_pmd_supported() to initialize the capabilities at boot-time.
      
      A new kernel option "nohugeiomap" is also added, so that user can disable
      the huge I/O map capabilities when necessary.
      Signed-off-by: NToshi Kani <toshi.kani@hp.com>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Dave Hansen <dave.hansen@intel.com>
      Cc: Robert Elliott <Elliott@hp.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      0ddab1d2
    • U
      watchdog: enable the new user interface of the watchdog mechanism · 195daf66
      Ulrich Obergfell 提交于
      With the current user interface of the watchdog mechanism it is only
      possible to disable or enable both lockup detectors at the same time.
      This series introduces new kernel parameters and changes the semantics of
      some existing kernel parameters, so that the hard lockup detector and the
      soft lockup detector can be disabled or enabled individually.  With this
      series applied, the user interface is as follows.
      
      - parameters in /proc/sys/kernel
      
        . soft_watchdog
          This is a new parameter to control and examine the run state of
          the soft lockup detector.
      
        . nmi_watchdog
          The semantics of this parameter have changed. It can now be used
          to control and examine the run state of the hard lockup detector.
      
        . watchdog
          This parameter is still available to control the run state of both
          lockup detectors at the same time. If this parameter is examined,
          it shows the logical OR of soft_watchdog and nmi_watchdog.
      
        . watchdog_thresh
          The semantics of this parameter are not affected by the patch.
      
      - kernel command line parameters
      
        . nosoftlockup
          The semantics of this parameter have changed. It can now be used
          to disable the soft lockup detector at boot time.
      
        . nmi_watchdog=0 or nmi_watchdog=1
          Disable or enable the hard lockup detector at boot time. The patch
          introduces '=1' as a new option.
      
        . nowatchdog
          The semantics of this parameter are not affected by the patch. It
          is still available to disable both lockup detectors at boot time.
      
      Also, remove the proc_dowatchdog() function which is no longer needed.
      
      [dzickus@redhat.com: wrote changelog]
      [dzickus@redhat.com: update documentation for kernel params and sysctl]
      Signed-off-by: NUlrich Obergfell <uobergfe@redhat.com>
      Signed-off-by: NDon Zickus <dzickus@redhat.com>
      Cc: Ingo Molnar <mingo@elte.hu>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      195daf66
  17. 10 4月, 2015 1 次提交
  18. 08 4月, 2015 1 次提交
  19. 04 4月, 2015 1 次提交
  20. 01 4月, 2015 2 次提交
  21. 25 3月, 2015 1 次提交
  22. 12 3月, 2015 1 次提交
    • P
      rcu: Provide diagnostic option to slow down grace-period initialization · 37745d28
      Paul E. McKenney 提交于
      Grace-period initialization normally proceeds quite quickly, so
      that it is very difficult to reproduce races against grace-period
      initialization.  This commit therefore allows grace-period
      initialization to be artificially slowed down, increasing
      race-reproduction probability.  A pair of new Kconfig parameters are
      provided, CONFIG_RCU_TORTURE_TEST_SLOW_INIT to enable the slowdowns, and
      CONFIG_RCU_TORTURE_TEST_SLOW_INIT_DELAY to specify the number of jiffies
      of slowdown to apply.  A boot-time parameter named rcutree.gp_init_delay
      allows boot-time delay to be specified.  By default, no delay will be
      applied even if CONFIG_RCU_TORTURE_TEST_SLOW_INIT is set.
      Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      37745d28
  23. 27 2月, 2015 1 次提交
  24. 26 2月, 2015 1 次提交
    • B
      PM / sleep: add configurable delay for pm_test · 1d4a9c17
      Brian Norris 提交于
      When CONFIG_PM_DEBUG=y, we provide a sysfs file (/sys/power/pm_test) for
      selecting one of a few suspend test modes, where rather than entering a
      full suspend state, the kernel will perform some subset of suspend
      steps, wait 5 seconds, and then resume back to normal operation.
      
      This mode is useful for (among other things) observing the state of the
      system just before entering a sleep mode, for debugging or analysis
      purposes. However, a constant 5 second wait is not sufficient for some
      sorts of analysis; for example, on an SoC, one might want to use
      external tools to probe the power states of various on-chip controllers
      or clocks.
      
      This patch turns this 5 second delay into a configurable module
      parameter, so users can determine how long to wait in this
      pseudo-suspend state before resuming the system.
      
      Example (wait 30 seconds);
      
        # echo 30 > /sys/module/suspend/parameters/pm_test_delay
        # echo core > /sys/power/pm_test
        # time echo mem  > /sys/power/state
        ...
        [   17.583625] suspend debug: Waiting for 30 second(s).
        ...
        real	0m30.381s
        user	0m0.017s
        sys	0m0.080s
      Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
      Acked-by: NPavel Machek <pavel@ucw.cz>
      Reviewed-by: NKevin Cernekee <cernekee@chromium.org>
      Acked-by: NFlorian Fainelli <f.fainelli@gmail.com>
      Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
      1d4a9c17
  25. 07 2月, 2015 1 次提交
  26. 03 2月, 2015 1 次提交
  27. 23 1月, 2015 1 次提交
  28. 10 1月, 2015 1 次提交
  29. 08 1月, 2015 1 次提交
  30. 15 12月, 2014 1 次提交
  31. 14 12月, 2014 3 次提交
    • J
      mm/page_owner: keep track of page owners · 48c96a36
      Joonsoo Kim 提交于
      This is the page owner tracking code which is introduced so far ago.  It
      is resident on Andrew's tree, though, nobody tried to upstream so it
      remain as is.  Our company uses this feature actively to debug memory leak
      or to find a memory hogger so I decide to upstream this feature.
      
      This functionality help us to know who allocates the page.  When
      allocating a page, we store some information about allocation in extra
      memory.  Later, if we need to know status of all pages, we can get and
      analyze it from this stored information.
      
      In previous version of this feature, extra memory is statically defined in
      struct page, but, in this version, extra memory is allocated outside of
      struct page.  It enables us to turn on/off this feature at boottime
      without considerable memory waste.
      
      Although we already have tracepoint for tracing page allocation/free,
      using it to analyze page owner is rather complex.  We need to enlarge the
      trace buffer for preventing overlapping until userspace program launched.
      And, launched program continually dump out the trace buffer for later
      analysis and it would change system behaviour with more possibility rather
      than just keeping it in memory, so bad for debug.
      
      Moreover, we can use page_owner feature further for various purposes.  For
      example, we can use it for fragmentation statistics implemented in this
      patch.  And, I also plan to implement some CMA failure debugging feature
      using this interface.
      
      I'd like to give the credit for all developers contributed this feature,
      but, it's not easy because I don't know exact history.  Sorry about that.
      Below is people who has "Signed-off-by" in the patches in Andrew's tree.
      
      Contributor:
      Alexander Nyberg <alexn@dsv.su.se>
      Mel Gorman <mgorman@suse.de>
      Dave Hansen <dave@linux.vnet.ibm.com>
      Minchan Kim <minchan@kernel.org>
      Michal Nazarewicz <mina86@mina86.com>
      Andrew Morton <akpm@linux-foundation.org>
      Jungsoo Son <jungsoo.son@lge.com>
      Signed-off-by: NJoonsoo Kim <iamjoonsoo.kim@lge.com>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: Minchan Kim <minchan@kernel.org>
      Cc: Dave Hansen <dave@sr71.net>
      Cc: Michal Nazarewicz <mina86@mina86.com>
      Cc: Jungsoo Son <jungsoo.son@lge.com>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      48c96a36
    • J
      mm/debug-pagealloc: make debug-pagealloc boottime configurable · 031bc574
      Joonsoo Kim 提交于
      Now, we have prepared to avoid using debug-pagealloc in boottime.  So
      introduce new kernel-parameter to disable debug-pagealloc in boottime, and
      makes related functions to be disabled in this case.
      
      Only non-intuitive part is change of guard page functions.  Because guard
      page is effective only if debug-pagealloc is enabled, turning off
      according to debug-pagealloc is reasonable thing to do.
      Signed-off-by: NJoonsoo Kim <iamjoonsoo.kim@lge.com>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: Minchan Kim <minchan@kernel.org>
      Cc: Dave Hansen <dave@sr71.net>
      Cc: Michal Nazarewicz <mina86@mina86.com>
      Cc: Jungsoo Son <jungsoo.son@lge.com>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      031bc574
    • L
      hugetlb: fix hugepages= entry in kernel-parameters.txt · 27ec26ec
      Luiz Capitulino 提交于
      The hugepages= entry in kernel-parameters.txt states that 1GB pages can
      only be allocated at boot time and not freed afterwards.  This is not
      true since commit 944d9fec ("hugetlb: add support for gigantic page
      allocation at runtime"), at least for x86_64.
      
      Instead of adding arch-specifc observations to the hugepages= entry,
      this commit just drops the out of date information.  Further information
      about arch-specific support and available features can be obtained in
      the hugetlb documentation.
      Signed-off-by: NLuiz Capitulino <lcapitulino@redhat.com>
      Cc: Andi Kleen <andi@firstfloor.org>
      Acked-by: NDavid Rientjes <rientjes@google.com>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Cc: Davidlohr Bueso <dave@stgolabs.net>
      Acked-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      27ec26ec
  32. 11 12月, 2014 1 次提交
    • P
      kernel: add panic_on_warn · 9e3961a0
      Prarit Bhargava 提交于
      There have been several times where I have had to rebuild a kernel to
      cause a panic when hitting a WARN() in the code in order to get a crash
      dump from a system.  Sometimes this is easy to do, other times (such as
      in the case of a remote admin) it is not trivial to send new images to
      the user.
      
      A much easier method would be a switch to change the WARN() over to a
      panic.  This makes debugging easier in that I can now test the actual
      image the WARN() was seen on and I do not have to engage in remote
      debugging.
      
      This patch adds a panic_on_warn kernel parameter and
      /proc/sys/kernel/panic_on_warn calls panic() in the
      warn_slowpath_common() path.  The function will still print out the
      location of the warning.
      
      An example of the panic_on_warn output:
      
      The first line below is from the WARN_ON() to output the WARN_ON()'s
      location.  After that the panic() output is displayed.
      
          WARNING: CPU: 30 PID: 11698 at /home/prarit/dummy_module/dummy-module.c:25 init_dummy+0x1f/0x30 [dummy_module]()
          Kernel panic - not syncing: panic_on_warn set ...
      
          CPU: 30 PID: 11698 Comm: insmod Tainted: G        W  OE  3.17.0+ #57
          Hardware name: Intel Corporation S2600CP/S2600CP, BIOS RMLSDP.86I.00.29.D696.1311111329 11/11/2013
           0000000000000000 000000008e3f87df ffff88080f093c38 ffffffff81665190
           0000000000000000 ffffffff818aea3d ffff88080f093cb8 ffffffff8165e2ec
           ffffffff00000008 ffff88080f093cc8 ffff88080f093c68 000000008e3f87df
          Call Trace:
           [<ffffffff81665190>] dump_stack+0x46/0x58
           [<ffffffff8165e2ec>] panic+0xd0/0x204
           [<ffffffffa038e05f>] ? init_dummy+0x1f/0x30 [dummy_module]
           [<ffffffff81076b90>] warn_slowpath_common+0xd0/0xd0
           [<ffffffffa038e040>] ? dummy_greetings+0x40/0x40 [dummy_module]
           [<ffffffff81076c8a>] warn_slowpath_null+0x1a/0x20
           [<ffffffffa038e05f>] init_dummy+0x1f/0x30 [dummy_module]
           [<ffffffff81002144>] do_one_initcall+0xd4/0x210
           [<ffffffff811b52c2>] ? __vunmap+0xc2/0x110
           [<ffffffff810f8889>] load_module+0x16a9/0x1b30
           [<ffffffff810f3d30>] ? store_uevent+0x70/0x70
           [<ffffffff810f49b9>] ? copy_module_from_fd.isra.44+0x129/0x180
           [<ffffffff810f8ec6>] SyS_finit_module+0xa6/0xd0
           [<ffffffff8166cf29>] system_call_fastpath+0x12/0x17
      
      Successfully tested by me.
      
      hpa said: There is another very valid use for this: many operators would
      rather a machine shuts down than being potentially compromised either
      functionally or security-wise.
      Signed-off-by: NPrarit Bhargava <prarit@redhat.com>
      Cc: Jonathan Corbet <corbet@lwn.net>
      Cc: Rusty Russell <rusty@rustcorp.com.au>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Andi Kleen <ak@linux.intel.com>
      Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
      Acked-by: NYasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
      Cc: Fabian Frederick <fabf@skynet.be>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      9e3961a0