1. 13 Mar, 2015 5 commits
    • John Stultz's avatar
      clocksource: Improve clocksource watchdog reporting · 0b046b21
      John Stultz authored
      The clocksource watchdog reporting has been less helpful
      then desired, as it just printed the delta between
      the two clocksources. This prevents any useful analysis
      of why the skew occurred.
      
      Thus this patch tries to improve the output when we
      mark a clocksource as unstable, printing out the cycle
      last and now values for both the current clocksource
      and the watchdog clocksource. This will allow us to see
      if the result was due to a false positive caused by
      a problematic watchdog.
      Signed-off-by: default avatarJohn Stultz <john.stultz@linaro.org>
      Cc: Dave Jones <davej@codemonkey.org.uk>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Prarit Bhargava <prarit@redhat.com>
      Cc: Richard Cochran <richardcochran@gmail.com>
      Cc: Stephen Boyd <sboyd@codeaurora.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Link: http://lkml.kernel.org/r/1426133800-29329-9-git-send-email-john.stultz@linaro.org
      [ Minor cleanups of kernel messages. ]
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      0b046b21
    • John Stultz's avatar
      timekeeping: Add warnings when overflows or underflows are observed · 4ca22c26
      John Stultz authored
      It was suggested that the underflow/overflow protection
      should probably throw some sort of warning out, rather
      than just silently fixing the issue.
      
      So this patch adds some warnings here. The flag variables
      used are not protected by locks, but since we can't print
      from the reading functions, just being able to say we
      saw an issue in the update interval is useful enough,
      and can be slightly racy without real consequence.
      
      The big complication is that we're only under a read
      seqlock, so the data could shift under us during
      our calculation to see if there was a problem. This
      patch avoids this issue by nesting another seqlock
      which allows us to snapshot the just required values
      atomically. So we shouldn't see false positives.
      
      I also added some basic rate-limiting here, since
      on one build machine w/ skewed TSCs it was fairly
      noisy at bootup.
      Signed-off-by: default avatarJohn Stultz <john.stultz@linaro.org>
      Cc: Dave Jones <davej@codemonkey.org.uk>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Prarit Bhargava <prarit@redhat.com>
      Cc: Richard Cochran <richardcochran@gmail.com>
      Cc: Stephen Boyd <sboyd@codeaurora.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Link: http://lkml.kernel.org/r/1426133800-29329-8-git-send-email-john.stultz@linaro.orgSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      4ca22c26
    • John Stultz's avatar
      timekeeping: Try to catch clocksource delta underflows · 057b87e3
      John Stultz authored
      In the case where there is a broken clocksource
      where there are multiple actual clocks that
      aren't perfectly aligned, we may see small "negative"
      deltas when we subtract 'now' from 'cycle_last'.
      
      The values are actually negative with respect to the
      clocksource mask value, not necessarily negative
      if cast to a s64, but we can check by checking the
      delta to see if it is a small (relative to the mask)
      negative value (again negative relative to the mask).
      
      If so, we assume we jumped backwards somehow and
      instead use zero for our delta.
      Signed-off-by: default avatarJohn Stultz <john.stultz@linaro.org>
      Cc: Dave Jones <davej@codemonkey.org.uk>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Prarit Bhargava <prarit@redhat.com>
      Cc: Richard Cochran <richardcochran@gmail.com>
      Cc: Stephen Boyd <sboyd@codeaurora.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Link: http://lkml.kernel.org/r/1426133800-29329-7-git-send-email-john.stultz@linaro.orgSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      057b87e3
    • John Stultz's avatar
      timekeeping: Add checks to cap clocksource reads to the 'max_cycles' value · a558cd02
      John Stultz authored
      When calculating the current delta since the last tick, we
      currently have no hard protections to prevent a multiplication
      overflow from occuring.
      
      This patch introduces infrastructure to allow a cap that
      limits the clocksource read delta value to the 'max_cycles' value,
      which is where an overflow would occur.
      
      Since this is in the hotpath, it adds the extra checking under
      CONFIG_DEBUG_TIMEKEEPING=y.
      
      There was some concern that capping time like this could cause
      problems as we may stop expiring timers, which could go circular
      if the timer that triggers time accumulation were mis-scheduled
      too far in the future, which would cause time to stop.
      
      However, since the mult overflow would result in a smaller time
      value, we would effectively have the same problem there.
      Signed-off-by: default avatarJohn Stultz <john.stultz@linaro.org>
      Cc: Dave Jones <davej@codemonkey.org.uk>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Prarit Bhargava <prarit@redhat.com>
      Cc: Richard Cochran <richardcochran@gmail.com>
      Cc: Stephen Boyd <sboyd@codeaurora.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Link: http://lkml.kernel.org/r/1426133800-29329-6-git-send-email-john.stultz@linaro.orgSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      a558cd02
    • John Stultz's avatar
      timekeeping: Add debugging checks to warn if we see delays · 3c17ad19
      John Stultz authored
      Recently there's been requests for better sanity
      checking in the time code, so that it's more clear
      when something is going wrong, since timekeeping issues
      could manifest in a large number of strange ways in
      various subsystems.
      
      Thus, this patch adds some extra infrastructure to
      add a check to update_wall_time() to print two new
      warnings:
      
       1) if we see the call delayed beyond the 'max_cycles'
          overflow point,
      
       2) or if we see the call delayed beyond the clocksource's
          'max_idle_ns' value, which is currently 50% of the
          overflow point.
      
      This extra infrastructure is conditional on
      a new CONFIG_DEBUG_TIMEKEEPING option, also
      added in this patch - default off.
      
      Tested this a bit by halting qemu for specified
      lengths of time to trigger the warnings.
      Signed-off-by: default avatarJohn Stultz <john.stultz@linaro.org>
      Cc: Dave Jones <davej@codemonkey.org.uk>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Prarit Bhargava <prarit@redhat.com>
      Cc: Richard Cochran <richardcochran@gmail.com>
      Cc: Stephen Boyd <sboyd@codeaurora.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Link: http://lkml.kernel.org/r/1426133800-29329-5-git-send-email-john.stultz@linaro.org
      [ Improved the changelog and the messages a bit. ]
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      3c17ad19
  2. 12 Mar, 2015 3 commits
    • John Stultz's avatar
      clocksource: Add 'max_cycles' to 'struct clocksource' · fb82fe2f
      John Stultz authored
      In order to facilitate clocksource validation, add a
      'max_cycles' field to the clocksource structure which
      will hold the maximum cycle value that can safely be
      multiplied without potentially causing an overflow.
      Signed-off-by: default avatarJohn Stultz <john.stultz@linaro.org>
      Cc: Dave Jones <davej@codemonkey.org.uk>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Prarit Bhargava <prarit@redhat.com>
      Cc: Richard Cochran <richardcochran@gmail.com>
      Cc: Stephen Boyd <sboyd@codeaurora.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Link: http://lkml.kernel.org/r/1426133800-29329-4-git-send-email-john.stultz@linaro.orgSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      fb82fe2f
    • John Stultz's avatar
      clocksource: Simplify the logic around clocksource wrapping safety margins · 362fde04
      John Stultz authored
      The clocksource logic has a number of places where we try to
      include a safety margin. Most of these are 12% safety margins,
      but they are inconsistently applied and sometimes are applied
      on top of each other.
      
      Additionally, in the previous patch, we corrected an issue
      where we unintentionally in effect created a 50% safety margin,
      which these 12.5% margins where then added to.
      
      So to simplify the logic here, this patch removes the various
      12.5% margins, and consolidates adding the margin in one place:
      clocks_calc_max_nsecs().
      
      Additionally, Linus prefers a 50% safety margin, as it allows
      bad clock values to be more easily caught. This should really
      have no net effect, due to the corrected issue earlier which
      caused greater then 50% margins to be used w/o issue.
      Signed-off-by: default avatarJohn Stultz <john.stultz@linaro.org>
      Acked-by: Stephen Boyd <sboyd@codeaurora.org> (for the sched_clock.c bit)
      Cc: Dave Jones <davej@codemonkey.org.uk>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Prarit Bhargava <prarit@redhat.com>
      Cc: Richard Cochran <richardcochran@gmail.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Link: http://lkml.kernel.org/r/1426133800-29329-3-git-send-email-john.stultz@linaro.orgSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      362fde04
    • John Stultz's avatar
      clocksource: Simplify the clocks_calc_max_nsecs() logic · 6086e346
      John Stultz authored
      The previous clocks_calc_max_nsecs() code had some unecessarily
      complex bit logic to find the max interval that could cause
      multiplication overflows. Since this is not in the hot
      path, just do the divide to make it easier to read.
      
      The previous implementation also had a subtle issue
      that it avoided overflows with signed 64-bit values, where
      as the intervals are always unsigned. This resulted in
      overly conservative intervals, which other safety margins
      were then added to, reducing the intended interval length.
      Signed-off-by: default avatarJohn Stultz <john.stultz@linaro.org>
      Cc: Dave Jones <davej@codemonkey.org.uk>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Prarit Bhargava <prarit@redhat.com>
      Cc: Richard Cochran <richardcochran@gmail.com>
      Cc: Stephen Boyd <sboyd@codeaurora.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Link: http://lkml.kernel.org/r/1426133800-29329-2-git-send-email-john.stultz@linaro.orgSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      6086e346
  3. 04 Mar, 2015 1 commit
  4. 03 Mar, 2015 2 commits
    • Linus Torvalds's avatar
      Linux 4.0-rc2 · 13a7a6ac
      Linus Torvalds authored
      13a7a6ac
    • Daniel Vetter's avatar
      drm/i915: Fix modeset state confusion in the load detect code · 9128b040
      Daniel Vetter authored
      This is a tricky story of the new atomic state handling and the legacy
      code fighting over each another. The bug at hand is an underrun of the
      framebuffer reference with subsequent hilarity caused by the load
      detect code. Which is peculiar since the the exact same code works
      fine as the implementation of the legacy setcrtc ioctl.
      
      Let's look at the ingredients:
      
      - Currently our code is a crazy mix of legacy modeset interfaces to
        set the parameters and half-baked atomic state tracking underneath.
        While this transition is going we're using the transitional plane
        helpers to update the atomic side (drm_plane_helper_disable/update
        and friends), i.e. plane->state->fb. Since the state structure owns
        the fb those functions take care of that themselves.
      
        The legacy state (specifically crtc->primary->fb) is still managed
        by the old code (and mostly by the drm core), with the fb reference
        counting done by callers (core drm for the ioctl or the i915 load
        detect code). The relevant commit is
      
        commit ea2c67bb
        Author: Matt Roper <matthew.d.roper@intel.com>
        Date:   Tue Dec 23 10:41:52 2014 -0800
      
            drm/i915: Move to atomic plane helpers (v9)
      
      - drm_plane_helper_disable has special code to handle multiple calls
        in a row - it checks plane->crtc == NULL and bails out. This is to
        match the proper atomic implementation which needs the crtc to get
        at the implied locking context atomic updates always need. See
      
        commit acf24a39
        Author: Daniel Vetter <daniel.vetter@ffwll.ch>
        Date:   Tue Jul 29 15:33:05 2014 +0200
      
            drm/plane-helper: transitional atomic plane helpers
      
      - The universal plane code split out the implicit primary plane from
        the CRTC into it's own full-blown drm_plane object. As part of that
        the setcrtc ioctl (which updated both the crtc mode and primary
        plane) learned to set crtc->primary->crtc on modeset to make sure
        the plane->crtc assignments statate up to date in
      
        commit e13161af
        Author: Matt Roper <matthew.d.roper@intel.com>
        Date:   Tue Apr 1 15:22:38 2014 -0700
      
            drm: Add drm_crtc_init_with_planes() (v2)
      
        Unfortunately we've forgotten to update the load detect code. Which
        wasn't a problem since the load detect modeset is temporary and
        always undone before we drop the locks.
      
      - Finally there is a organically grown history (i.e. don't ask) around
        who sets the legacy plane->fb for the various driver entry points.
        Originally updating that was the drivers duty, but for almost all
        places we've moved that (plus updating the refcounts) into the core.
        Again the exception is the load detect code.
      
      Taking all together the following happens:
      - The load detect code doesn't set crtc->primary->crtc. This is only
        really an issue on crtcs never before used or when userspace
        explicitly disabled the primary plane.
      
      - The plane helper glue code short-circuits because of that and leaves
        a non-NULL fb behind in plane->state->fb and plane->fb. The state
        fb isn't a real problem (it's properly refcounted on its own), it's
        just the canary.
      
      - Load detect code drops the reference for that fb, but doesn't set
        plane->fb = NULL. This is ok since it's still living in that old
        world where drivers had to clear the pointer but the core/callers
        handled the refcounting.
      
      - On the next modeset the drm core notices plane->fb and takes care of
        refcounting it properly by doing another unref. This drops the
        refcount to zero, leaving state->plane now pointing at freed memory.
      
      - intel_plane_duplicate_state still assume it owns a reference to that
        very state->fb and bad things start to happen.
      
      Fix this all by applying the same duct-tape as for the legacy setcrtc
      ioctl code and set crtc->primary->crtc properly.
      
      Cc: Matt Roper <matthew.d.roper@intel.com>
      Cc: Paul Bolle <pebolle@tiscali.nl>
      Cc: Rob Clark <robdclark@gmail.com>
      Cc: Paulo Zanoni <przanoni@gmail.com>
      Cc: Sean Paul <seanpaul@chromium.org>
      Cc: Matt Roper <matthew.d.roper@intel.com>
      Reported-and-tested-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Reported-by: default avatarPaul Bolle <pebolle@tiscali.nl>
      Signed-off-by: default avatarDaniel Vetter <daniel.vetter@intel.com>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      9128b040
  5. 02 Mar, 2015 4 commits
    • Linus Torvalds's avatar
      Merge tag 'gpio-v4.0-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio · 023a6007
      Linus Torvalds authored
      Pull GPIO fixes from Linus Walleij:
       "Two GPIO fixes:
      
         - Fix a translation problem in of_get_named_gpiod_flags()
      
         - Fix a long standing container_of() mistake in the TPS65912 driver"
      
      * tag 'gpio-v4.0-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio:
        gpio: tps65912: fix wrong container_of arguments
        gpiolib: of: allow of_gpiochip_find_and_xlate to find more than one chip per node
      023a6007
    • Linus Torvalds's avatar
      Merge branch 'fixes-for-4.0-rc2' of... · 10d6dfc1
      Linus Torvalds authored
      Merge branch 'fixes-for-4.0-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/evalenti/linux-soc-thermal
      
      Pull thermal management fixes from Eduardo Valentin:
       "Specifics:
      
         - Several fixes in tmon tool.
      
         - Fixes in intel int340x for _ART and _TRT tables.
      
         - Add id for Avoton SoC into powerclamp driver.
      
         - Fixes in RCAR thermal driver to remove race conditions and fix fail
           path
      
         - Fixes in TI thermal driver: removal of unnecessary code and build
           fix if !CONFIG_PM_SLEEP
      
         - Cleanups in exynos thermal driver
      
         - Add stubs for include/linux/thermal.h.  Now drivers using thermal
           calls but that also work without CONFIG_THERMAL will be able to
           compile for systems that don't care about thermal.
      
        Note: I am sending this pull on Rui's behalf while he fixes issues in
        his Linux box"
      
      * 'fixes-for-4.0-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/evalenti/linux-soc-thermal:
        thermal: int340x_thermal: Ignore missing _ART, _TRT tables
        thermal/intel_powerclamp: add id for Avoton SoC
        tools/thermal: tmon: silence 'set but not used' warnings
        tools/thermal: tmon: use pkg-config to determine library dependencies
        tools/thermal: tmon: support cross-compiling
        tools/thermal: tmon: add .gitignore
        tools/thermal: tmon: fixup tui windowing calculations
        tools/thermal: tmon: tui: don't hard-code dialog window size assumptions
        tools/thermal: tmon: add min/max macros
        tools/thermal: tmon: add --target-temp parameter
        thermal: exynos: Clean-up code to use oneline entry for exynos compatible table
        thermal: rcar: Make error and remove paths symmetrical with init
        thermal: rcar: Fix race condition between init and interrupt
        thermal: Introduce dummy functions when thermal is not defined
        ti-soc-thermal: Delete an unnecessary check before the function call "cpufreq_cooling_unregister"
        thermal: ti-soc-thermal: bandgap: Fix build warning if !CONFIG_PM_SLEEP
      10d6dfc1
    • Linus Torvalds's avatar
      Merge tag 'md/4.0-fixes' of git://neil.brown.name/md · 1a6f77ab
      Linus Torvalds authored
      Pull md fixes from Neil Brown:
       "Three md fixes:
      
         - fix a read-balance problem that was reported 2 years ago, but that
           I never noticed the report :-(
      
         - fix for rare RAID6 problem causing incorrect bitmap updates when
           two devices fail.
      
         - add __ATTR_PREALLOC annotation now that it is possible"
      
      * tag 'md/4.0-fixes' of git://neil.brown.name/md:
        md: mark some attributes as pre-alloc
        raid5: check faulty flag for array status during recovery.
        md/raid1: fix read balance when a drive is write-mostly.
      1a6f77ab
    • Linus Torvalds's avatar
      Merge tag 'metag-fixes-v4.0-1' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/metag · 49db1f0e
      Linus Torvalds authored
      Pull arch/metag fix from James Hogan:
       "This is just a single patch to fix the KSTK_EIP() and KSTK_ESP()
        macros for metag which have always been erronously returning the PC
        and stack pointer of the task's kernel context rather than from its
        user context saved at entry from userland into the kernel, which
        affects the contents of /proc/<pid>/maps and /proc/<pid>/stat"
      
      * tag 'metag-fixes-v4.0-1' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/metag:
        metag: Fix KSTK_EIP() and KSTK_ESP() macros
      49db1f0e
  6. 01 Mar, 2015 6 commits
  7. 28 Feb, 2015 19 commits
    • Linus Torvalds's avatar
      Merge branch 'drm-fixes' of git://people.freedesktop.org/~airlied/linux · ae1aa797
      Linus Torvalds authored
      Pull drm fixes from Dave Airlie:
       "Just general fixes: radeon, i915, atmel, tegra, amdkfd and one core
        fix"
      
      * 'drm-fixes' of git://people.freedesktop.org/~airlied/linux: (28 commits)
        drm: atmel-hlcdc: remove clock polarity from crtc driver
        drm/radeon: only enable DP audio if the monitor supports it
        drm/radeon: fix atom aux payload size check for writes (v2)
        drm/radeon: fix 1 RB harvest config setup for TN/RL
        drm/radeon: enable SRBM timeout interrupt on EG/NI
        drm/radeon: enable SRBM timeout interrupt on SI
        drm/radeon: enable SRBM timeout interrupt on CIK v2
        drm/radeon: dump full IB if we hit a packet error
        drm/radeon: disable mclk switching with 120hz+ monitors
        drm/radeon: use drm_mode_vrefresh() rather than mode->vrefresh
        drm/radeon: enable native backlight control on old macs
        drm/i915: Fix frontbuffer false positve.
        drm/i915: Align initial plane backing objects correctly
        drm/i915: avoid processing spurious/shared interrupts in low-power states
        drm/i915: Check obj->vma_list under the struct_mutex
        drm/i915: Fix a use after free, and unbalanced refcounting
        drm: atmel-hlcdc: remove useless pm_runtime_put_sync in probe
        drm: atmel-hlcdc: reset layer A2Q and UPDATE bits when disabling it
        drm: Fix deadlock due to getconnector locking changes
        drm/i915: Dell Chromebook 11 has PWM backlight
        ...
      ae1aa797
    • Linus Torvalds's avatar
      Merge branch 'for-linus' of git://git.kernel.dk/linux-block · a015d33c
      Linus Torvalds authored
      Pull block layer fixes from Jens Axboe:
       "Two smaller fixes for this cycle:
      
         - A fixup from Keith so that NVMe compiles without BLK_INTEGRITY,
           basically just moving the code around appropriately.
      
         - A fixup for shm, fixing an oops in shmem_mapping() for mapping with
           no inode.  From Sasha"
      
      [ The shmem fix doesn't look block-layer-related, but fixes a bug that
        happened due to the backing_dev_info removal..  - Linus ]
      
      * 'for-linus' of git://git.kernel.dk/linux-block:
        mm: shmem: check for mapping owner before dereferencing
        NVMe: Fix for BLK_DEV_INTEGRITY not set
      a015d33c
    • Linus Torvalds's avatar
      Merge tag 'xfs-for-linus-4.0-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs · 2aaeb784
      Linus Torvalds authored
      Pull xfs fixes from Dave Chinner:
       "These are fixes for regressions/bugs introduced in the 4.0 merge cycle
        and problems discovered during the merge window that need to be pushed
        back to stable kernels ASAP.
      
        This contains:
         - ensure quota type is reset in on-disk dquots
         - fix missing partial EOF block data flush on truncate extension
         - fix transaction leak in error handling for new pnfs block layout
           support
         - add missing target_ip check to RENAME_EXCHANGE"
      
      * tag 'xfs-for-linus-4.0-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs:
        xfs: cancel failed transaction in xfs_fs_commit_blocks()
        xfs: Ensure we have target_ip for RENAME_EXCHANGE
        xfs: ensure truncate forces zeroed blocks to disk
        xfs: Fix quota type in quota structures when reusing quota file
      2aaeb784
    • Linus Torvalds's avatar
      Merge branch 'akpm' (patches from Andrew) · e9738946
      Linus Torvalds authored
      Merge misc fixes from Andrew Morton:
       "13 fixes"
      
      * emailed patches from Andrew Morton <akpm@linux-foundation.org>:
        mm: add missing __PAGETABLE_{PUD,PMD}_FOLDED defines
        mm: page_alloc: revert inadvertent !__GFP_FS retry behavior change
        kernel/sys.c: fix UNAME26 for 4.0
        mm: memcontrol: use "max" instead of "infinity" in control knobs
        zram: use proper type to update max_used_pages
        drivers/rtc/rtc-ds1685.c: fix conditional in ds1685_rtc_sysfs_time_regs_{show,store}
        nilfs2: fix potential memory overrun on inode
        scripts/gdb: add empty package initialization script
        rtc: ds1685: remove superfluous checks for out-of-range u8 values
        rtc: ds1685: fix ds1685_rtc_alarm_irq_enable build error
        memcg: fix low limit calculation
        mm/nommu: fix memory leak
        ocfs2: update web page + git tree in documentation
      e9738946
    • Kirill A. Shutemov's avatar
      mm: add missing __PAGETABLE_{PUD,PMD}_FOLDED defines · c07af4f1
      Kirill A. Shutemov authored
      Core mm expects __PAGETABLE_{PUD,PMD}_FOLDED to be defined if these page
      table levels folded.  Usually, these defines are provided by
      <asm-generic/pgtable-nopmd.h> and <asm-generic/pgtable-nopud.h>.
      
      But some architectures fold page table levels in a custom way.  They
      need to define these macros themself.  This patch adds missing defines.
      
      The patch fixes mm->nr_pmds underflow and eliminates dead __pmd_alloc()
      and __pud_alloc() on architectures without these page table levels.
      Signed-off-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
      Cc: Aaro Koskinen <aaro.koskinen@iki.fi>
      Cc: David Howells <dhowells@redhat.com>
      Cc: Geert Uytterhoeven <geert@linux-m68k.org>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Helge Deller <deller@gmx.de>
      Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
      Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      c07af4f1
    • Johannes Weiner's avatar
      mm: page_alloc: revert inadvertent !__GFP_FS retry behavior change · cc873177
      Johannes Weiner authored
      Historically, !__GFP_FS allocations were not allowed to invoke the OOM
      killer once reclaim had failed, but nevertheless kept looping in the
      allocator.
      
      Commit 9879de73 ("mm: page_alloc: embed OOM killing naturally into
      allocation slowpath"), which should have been a simple cleanup patch,
      accidentally changed the behavior to aborting the allocation at that
      point.  This creates problems with filesystem callers (?) that currently
      rely on the allocator waiting for other tasks to intervene.
      
      Revert the behavior as it shouldn't have been changed as part of a
      cleanup patch.
      
      Fixes: 9879de73 ("mm: page_alloc: embed OOM killing naturally into allocation slowpath")
      Signed-off-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
      Acked-by: default avatarMichal Hocko <mhocko@suse.cz>
      Reported-by: default avatarTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
      Cc: Theodore Ts'o <tytso@mit.edu>
      Cc: Dave Chinner <david@fromorbit.com>
      Acked-by: default avatarDavid Rientjes <rientjes@google.com>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: <stable@vger.kernel.org>	[3.19.x]
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      cc873177
    • Jon DeVree's avatar
      kernel/sys.c: fix UNAME26 for 4.0 · 39afb5ee
      Jon DeVree authored
      There's a uname workaround for broken userspace which can't handle kernel
      versions of 3.x.  Update it for 4.x.
      Signed-off-by: default avatarJon DeVree <nuxi@vault24.org>
      Cc: Andi Kleen <andi@firstfloor.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      39afb5ee
    • Johannes Weiner's avatar
      mm: memcontrol: use "max" instead of "infinity" in control knobs · d2973697
      Johannes Weiner authored
      The memcg control knobs indicate the highest possible value using the
      symbolic name "infinity", which is long and awkward to type.
      
      Switch to the string "max", which is just as descriptive but shorter and
      sweeter.
      
      This changes a user interface, so do it before the release and before
      the development flag is dropped from the default hierarchy.
      Signed-off-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Tejun Heo <tj@kernel.org>
      Cc: Vladimir Davydov <vdavydov@parallels.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      d2973697
    • Joonsoo Kim's avatar
      zram: use proper type to update max_used_pages · 2ea55a2c
      Joonsoo Kim authored
      max_used_pages is defined as atomic_long_t so we need to use unsigned
      long to keep temporary value for it rather than int which is smaller
      than unsigned long in a 64 bit system.
      Signed-off-by: default avatarJoonsoo Kim <iamjoonsoo.kim@lge.com>
      Cc: Minchan Kim <minchan@kernel.org>
      Cc: Jerome Marchand <jmarchan@redhat.com>
      Cc: Nitin Gupta <ngupta@vflare.org>
      Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      2ea55a2c
    • Joshua Kinard's avatar
      drivers/rtc/rtc-ds1685.c: fix conditional in ds1685_rtc_sysfs_time_regs_{show,store} · b00eeaed
      Joshua Kinard authored
      Fix a conditional statement checking for NULL in both
      ds1685_rtc_sysfs_time_regs_show and ds1685_rtc_sysfs_time_regs_store
      that was using a logical AND when it should be using a logical OR so
      that we fail out of the function properly if the condition ever
      evaluates to true.
      
      Fixes: aaaf5fbf ("rtc: add driver for DS1685 family of real time clocks")
      Signed-off-by: default avatarJoshua Kinard <kumba@gentoo.org>
      Reported-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      b00eeaed
    • Ryusuke Konishi's avatar
      nilfs2: fix potential memory overrun on inode · 957ed60b
      Ryusuke Konishi authored
      Each inode of nilfs2 stores a root node of a b-tree, and it turned out to
      have a memory overrun issue:
      
      Each b-tree node of nilfs2 stores a set of key-value pairs and the number
      of them (in "bn_nchildren" member of nilfs_btree_node struct), as well as
      a few other "bn_*" members.
      
      Since the value of "bn_nchildren" is used for operations on the key-values
      within the b-tree node, it can cause memory access overrun if a large
      number is incorrectly set to "bn_nchildren".
      
      For instance, nilfs_btree_node_lookup() function determines the range of
      binary search with it, and too large "bn_nchildren" leads
      nilfs_btree_node_get_key() in that function to overrun.
      
      As for intermediate b-tree nodes, this is prevented by a sanity check
      performed when each node is read from a drive, however, no sanity check
      has been done for root nodes stored in inodes.
      
      This patch fixes the issue by adding missing sanity check against b-tree
      root nodes so that it's called when on-memory inodes are read from ifile,
      inode metadata file.
      Signed-off-by: default avatarRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      957ed60b
    • Jan Kiszka's avatar
      scripts/gdb: add empty package initialization script · 586a1a12
      Jan Kiszka authored
      This got lost during the initial merge process: Python requires an
      __init__.py script, even if empty, in order to accept a directory as
      package.  Add it, this time as a non-empty file.
      Signed-off-by: default avatarJan Kiszka <jan.kiszka@siemens.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      586a1a12
    • Geert Uytterhoeven's avatar
      rtc: ds1685: remove superfluous checks for out-of-range u8 values · 39ea34cc
      Geert Uytterhoeven authored
      drivers/rtc/rtc-ds1685.c: In function `ds1685_rtc_read_alarm':
      drivers/rtc/rtc-ds1685.c:402: warning: comparison is always true due to limited range of data type
      drivers/rtc/rtc-ds1685.c:409: warning: comparison is always true due to limited range of data type
      drivers/rtc/rtc-ds1685.c:416: warning: comparison is always true due to limited range of data type
      drivers/rtc/rtc-ds1685.c: In function `ds1685_rtc_set_alarm':
      drivers/rtc/rtc-ds1685.c:475: warning: comparison is always true due to limited range of data type
      drivers/rtc/rtc-ds1685.c:478: warning: comparison is always true due to limited range of data type
      drivers/rtc/rtc-ds1685.c:481: warning: comparison is always true due to limited range of data type
      
      u8 cannot contain a value larger than 0xff, hence drop the checks.
      Wrapping the checks in unlikely() indicated some sense of humor, though ;-)
      Signed-off-by: default avatarGeert Uytterhoeven <geert@linux-m68k.org>
      Acked-by: default avatarJoshua Kinard <kumba@gentoo.org>
      Cc: Alessandro Zummo <a.zummo@towertech.it>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      39ea34cc
    • Arnd Bergmann's avatar
      rtc: ds1685: fix ds1685_rtc_alarm_irq_enable build error · 682354d4
      Arnd Bergmann authored
      The newly added ds1685 driver causes a build error when enabled without
      CONFIG_RTC_INTF_DEV:
      
        drivers/rtc/rtc-ds1685.c:919:22: error: 'ds1685_rtc_alarm_irq_enable' undeclared here (not in a function)
          .alarm_irq_enable = ds1685_rtc_alarm_irq_enable,
      
      Apparently the driver was incorrectly changed to reflect the interface
      change from 16380c15 ("RTC: Convert rtc drivers to use the
      alarm_irq_enable method"), which removed the respective #ifdef from all
      other rtc drivers.
      
      This does the same change that was merged for the other drivers before and
      removes the #ifdef, allowing the interrupts to be enabled through the
      in-kernel rtc interface independent of the existence of /dev/rtc.
      
      Fixes: aaaf5fbf ("rtc: add driver for DS1685 family of real time clocks")
      Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
      Acked-by: default avatarJoshua Kinard <kumba@gentoo.org>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Alessandro Zummo <a.zummo@towertech.it>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      682354d4
    • Michal Hocko's avatar
      memcg: fix low limit calculation · 4e54dede
      Michal Hocko authored
      A memcg is considered low limited even when the current usage is equal to
      the low limit.  This leads to interesting side effects e.g.
      groups/hierarchies with no memory accounted are considered protected and
      so the reclaim will emit MEMCG_LOW event when encountering them.
      
      Another and much bigger issue was reported by Joonsoo Kim.  He has hit a
      NULL ptr dereference with the legacy cgroup API which even doesn't have
      low limit exposed.  The limit is 0 by default but the initial check fails
      for memcg with 0 consumption and parent_mem_cgroup() would return NULL if
      use_hierarchy is 0 and so page_counter_read would try to dereference NULL.
      
      I suppose that the current implementation is just an overlook because the
      documentation in Documentation/cgroups/unified-hierarchy.txt says:
      
        "The memory.low boundary on the other hand is a top-down allocated
        reserve.  A cgroup enjoys reclaim protection when it and all its
        ancestors are below their low boundaries"
      
      Fix the usage and the low limit comparision in mem_cgroup_low accordingly.
      
      Fixes: 241994ed (mm: memcontrol: default hierarchy interface for memory)
      Reported-by: default avatarJoonsoo Kim <js1304@gmail.com>
      Signed-off-by: default avatarMichal Hocko <mhocko@suse.cz>
      Acked-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      4e54dede
    • Joonsoo Kim's avatar
      mm/nommu: fix memory leak · da616534
      Joonsoo Kim authored
      Maxime reported the following memory leak regression due to commit
      dbc8358c ("mm/nommu: use alloc_pages_exact() rather than its own
      implementation").
      
      On v3.19, I am facing a memory leak.  Each time I run a command one page
      is lost.  Here an example with busybox's free command:
      
        / # free
                     total       used       free     shared    buffers     cached
        Mem:          7928       1972       5956          0          0        492
        -/+ buffers/cache:       1480       6448
        / # free
                     total       used       free     shared    buffers     cached
        Mem:          7928       1976       5952          0          0        492
        -/+ buffers/cache:       1484       6444
        / # free
                     total       used       free     shared    buffers     cached
        Mem:          7928       1980       5948          0          0        492
        -/+ buffers/cache:       1488       6440
        / # free
                     total       used       free     shared    buffers     cached
        Mem:          7928       1984       5944          0          0        492
        -/+ buffers/cache:       1492       6436
        / # free
                     total       used       free     shared    buffers     cached
        Mem:          7928       1988       5940          0          0        492
        -/+ buffers/cache:       1496       6432
      
      At some point, the system fails to sastisfy 256KB allocations:
      
        free: page allocation failure: order:6, mode:0xd0
        CPU: 0 PID: 67 Comm: free Not tainted 3.19.0-05389-gacf2cf1-dirty #64
        Hardware name: STM32 (Device Tree Support)
          show_stack+0xb/0xc
          warn_alloc_failed+0x97/0xbc
          __alloc_pages_nodemask+0x295/0x35c
          __get_free_pages+0xb/0x24
          alloc_pages_exact+0x19/0x24
          do_mmap_pgoff+0x423/0x658
          vm_mmap_pgoff+0x3f/0x4e
          load_flat_file+0x20d/0x4f8
          load_flat_binary+0x3f/0x26c
          search_binary_handler+0x51/0xe4
          do_execveat_common+0x271/0x35c
          do_execve+0x19/0x1c
          ret_fast_syscall+0x1/0x4a
        Mem-info:
        Normal per-cpu:
        CPU    0: hi:    0, btch:   1 usd:   0
        active_anon:0 inactive_anon:0 isolated_anon:0
         active_file:0 inactive_file:0 isolated_file:0
         unevictable:123 dirty:0 writeback:0 unstable:0
         free:1515 slab_reclaimable:17 slab_unreclaimable:139
         mapped:0 shmem:0 pagetables:0 bounce:0
         free_cma:0
        Normal free:6060kB min:352kB low:440kB high:528kB active_anon:0kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:492kB isolated(anon):0ks
        lowmem_reserve[]: 0 0
        Normal: 23*4kB (U) 22*8kB (U) 24*16kB (U) 23*32kB (U) 23*64kB (U) 23*128kB (U) 1*256kB (U) 0*512kB 0*1024kB 0*2048kB 0*4096kB = 6060kB
        123 total pagecache pages
        2048 pages of RAM
        1538 free pages
        66 reserved pages
        109 slab pages
        -46 pages shared
        0 pages swap cached
        nommu: Allocation of length 221184 from process 67 (free) failed
        Normal per-cpu:
        CPU    0: hi:    0, btch:   1 usd:   0
        active_anon:0 inactive_anon:0 isolated_anon:0
         active_file:0 inactive_file:0 isolated_file:0
         unevictable:123 dirty:0 writeback:0 unstable:0
         free:1515 slab_reclaimable:17 slab_unreclaimable:139
         mapped:0 shmem:0 pagetables:0 bounce:0
         free_cma:0
        Normal free:6060kB min:352kB low:440kB high:528kB active_anon:0kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:492kB isolated(anon):0ks
        lowmem_reserve[]: 0 0
        Normal: 23*4kB (U) 22*8kB (U) 24*16kB (U) 23*32kB (U) 23*64kB (U) 23*128kB (U) 1*256kB (U) 0*512kB 0*1024kB 0*2048kB 0*4096kB = 6060kB
        123 total pagecache pages
        Unable to allocate RAM for process text/data, errno 12 SEGV
      
      This problem happens because we allocate ordered page through
      __get_free_pages() in do_mmap_private() in some cases and we try to free
      individual pages rather than ordered page in free_page_series().  In
      this case, freeing pages whose refcount is not 0 won't be freed to the
      page allocator so memory leak happens.
      
      To fix the problem, this patch changes __get_free_pages() to
      alloc_pages_exact() since alloc_pages_exact() returns
      physically-contiguous pages but each pages are refcounted.
      
      Fixes: dbc8358c ("mm/nommu: use alloc_pages_exact() rather than its own implementation").
      Reported-by: default avatarMaxime Coquelin <mcoquelin.stm32@gmail.com>
      Tested-by: default avatarMaxime Coquelin <mcoquelin.stm32@gmail.com>
      Signed-off-by: default avatarJoonsoo Kim <iamjoonsoo.kim@lge.com>
      Cc: <stable@vger.kernel.org>	[3.19]
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      da616534
    • Mark Fasheh's avatar
      ocfs2: update web page + git tree in documentation · 01945fa2
      Mark Fasheh authored
      We (the Ocfs2 project) recently moved the location of our ocfs2-tools
      git tree and project web page.  The pertinent discussion can be seen
      here:
      
        https://oss.oracle.com/pipermail/ocfs2-devel/2015-February/010579.html
      
      The following patch updates the Ocfs2 documentation in MAINTAINERS,
      ocfs2.txt, and dlmfs.txt.  I added our new official web page, changed
      the location of our tools git tree and removed the link to Joel's
      ancient kernel git tree - Andrew has handled our patches for a while
      now.
      Signed-off-by: default avatarMark Fasheh <mfasheh@suse.de>
      Cc: Joel Becker <jlbec@evilplan.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      01945fa2
    • Steven Rostedt's avatar
      x86: Init per-cpu shadow copy of CR4 on 32-bit CPUs too · 5b2bdbc8
      Steven Rostedt authored
      Commit:
      
         1e02ce4c ("x86: Store a per-cpu shadow copy of CR4")
      
      added a shadow CR4 such that reads and writes that do not
      modify the CR4 execute much faster than always reading the
      register itself.
      
      The change modified cpu_init() in common.c, so that the
      shadow CR4 gets initialized before anything uses it.
      
      Unfortunately, there's two cpu_init()s in common.c. There's
      one for 64-bit and one for 32-bit. The commit only added
      the shadow init to the 64-bit path, but the 32-bit path
      needs the init too.
      
      Link: http://lkml.kernel.org/r/20150227125208.71c36402@gandalf.local.home Fixes: 1e02ce4c "x86: Store a per-cpu shadow copy of CR4"
      Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      Acked-by: default avatarAndy Lutomirski <luto@amacapital.net>
      Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Link: http://lkml.kernel.org/r/20150227145019.2bdd4354@gandalf.local.homeSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      5b2bdbc8
    • Ingo Molnar's avatar