1. 23 Jul, 2018 9 commits
    • Lukas Wunner's avatar
      PCI: pciehp: Convert to threaded polling · ec07a447
      Lukas Wunner authored
      We've just converted pciehp to threaded IRQ handling, but still cannot
      sleep in pciehp_ist() because the function is also called in poll mode,
      which runs in softirq context (from a timer).
      
      Convert poll mode to a kthread so that pciehp_ist() always runs in task
      context.
      Signed-off-by: default avatarLukas Wunner <lukas@wunner.de>
      Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      ec07a447
    • Lukas Wunner's avatar
      PCI: pciehp: Convert to threaded IRQ · 7b4ce26b
      Lukas Wunner authored
      pciehp's IRQ handler queues up a work item for each event signaled by
      the hardware.  A more modern alternative is to let a long running
      kthread service the events.  The IRQ handler's sole job is then to check
      whether the IRQ originated from the device in question, acknowledge its
      receipt to the hardware to quiesce the interrupt and wake up the kthread.
      
      One benefit is reduced latency to handle the IRQ, which is a necessity
      for realtime environments.  Another benefit is that we can make pciehp
      simpler and more robust by handling events synchronously in process
      context, rather than asynchronously by queueing up work items.  pciehp's
      usage of work items is a historic artifact, it predates the introduction
      of threaded IRQ handlers by two years.  (The former was introduced in
      2007 with commit 5d386e1a ("pciehp: Event handling rework"), the
      latter in 2009 with commit 3aa551c9 ("genirq: add threaded interrupt
      handler support").)
      
      Convert pciehp to threaded IRQ handling by retrieving the pending events
      in pciehp_isr(), saving them for later consumption by the thread handler
      pciehp_ist() and clearing them in the Slot Status register.
      
      By clearing the Slot Status (and thereby acknowledging the events) in
      pciehp_isr(), we can avoid requesting the IRQ with IRQF_ONESHOT, which
      would have the unpleasant side effect of starving devices sharing the
      IRQ until pciehp_ist() has finished.
      
      pciehp_isr() does not count how many times each event occurred, but
      merely records the fact *that* an event occurred.  If the same event
      occurs a second time before pciehp_ist() is woken, that second event
      will not be recorded separately, which is problematic according to
      commit fad214b0 ("PCI: pciehp: Process all hotplug events before
      looking for new ones") because we may miss removal of a card in-between
      two back-to-back insertions.  We're about to make pciehp_ist() resilient
      to missed events.  The present commit regresses the driver's behavior
      temporarily in order to separate the changes into reviewable chunks.
      This doesn't affect regular slow-motion hotplug, only plug-unplug-plug
      operations that happen in a timespan shorter than wakeup of the IRQ
      thread.
      Signed-off-by: default avatarLukas Wunner <lukas@wunner.de>
      Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Mayurkumar Patel <mayurkumar.patel@intel.com>
      Cc: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
      7b4ce26b
    • Lukas Wunner's avatar
      PCI: pciehp: Document struct slot and struct controller · 4aed1cd6
      Lukas Wunner authored
      Document the driver's data structures to lower the barrier to entry for
      contributors.
      Signed-off-by: default avatarLukas Wunner <lukas@wunner.de>
      Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
      4aed1cd6
    • Lukas Wunner's avatar
      PCI: pciehp: Declare pciehp_unconfigure_device() void · 1d2e2673
      Lukas Wunner authored
      Since commit 0f4bd801 ("PCI: hotplug: Drop checking of PCI_BRIDGE_
      CONTROL in *_unconfigure_device()"), pciehp_unconfigure_device() can no
      longer fail, so declare it and its sole caller remove_board() void, in
      keeping with the usual kernel pattern that enablement can fail, but
      disablement cannot.  No functional change intended.
      Signed-off-by: default avatarLukas Wunner <lukas@wunner.de>
      Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
      Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
      1d2e2673
    • Lukas Wunner's avatar
      PCI: pciehp: Drop unnecessary NULL pointer check · 6641311d
      Lukas Wunner authored
      pciehp_disable_slot() checks if the ctrl attribute of the slot is NULL
      and bails out if so.  However the function is not called prior to the
      attribute being set in pcie_init_slot(), and pcie_init_slot() is not
      called if ctrl is NULL.  So the check is unnecessary.  Drop it.
      
      It has been present ever since the driver was introduced in 2004, but it
      was already unnecessary back then:
      https://git.kernel.org/tglx/history/c/c16b4b14d980Signed-off-by: default avatarLukas Wunner <lukas@wunner.de>
      Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
      6641311d
    • Lukas Wunner's avatar
      PCI: pciehp: Fix unprotected list iteration in IRQ handler · 1204e35b
      Lukas Wunner authored
      Commit b440bde7 ("PCI: Add pci_ignore_hotplug() to ignore hotplug
      events for a device") iterates over the devices on a hotplug port's
      subordinate bus in pciehp's IRQ handler without acquiring pci_bus_sem.
      It is thus possible for a user to cause a crash by concurrently
      manipulating the device list, e.g. by disabling slot power via sysfs
      on a different CPU or by initiating a remove/rescan via sysfs.
      
      This can't be fixed by acquiring pci_bus_sem because it may sleep.
      The simplest fix is to avoid the list iteration altogether and just
      check the ignore_hotplug flag on the port itself.  This works because
      pci_ignore_hotplug() sets the flag both on the device as well as on its
      parent bridge.
      
      We do lose the ability to print the name of the device blocking hotplug
      in the debug message, but that's probably bearable.
      
      Fixes: b440bde7 ("PCI: Add pci_ignore_hotplug() to ignore hotplug events for a device")
      Signed-off-by: default avatarLukas Wunner <lukas@wunner.de>
      Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
      Cc: stable@vger.kernel.org
      1204e35b
    • Lukas Wunner's avatar
      PCI: pciehp: Fix use-after-free on unplug · 281e878e
      Lukas Wunner authored
      When pciehp is unbound (e.g. on unplug of a Thunderbolt device), the
      hotplug_slot struct is deregistered and thus freed before freeing the
      IRQ.  The IRQ handler and the work items it schedules print the slot
      name referenced from the freed structure in various informational and
      debug log messages, each time resulting in a quadruple dereference of
      freed pointers (hotplug_slot -> pci_slot -> kobject -> name).
      
      At best the slot name is logged as "(null)", at worst kernel memory is
      exposed in logs or the driver crashes:
      
        pciehp 0000:10:00.0:pcie204: Slot((null)): Card not present
      
      An attacker may provoke the bug by unplugging multiple devices on a
      Thunderbolt daisy chain at once.  Unplugging can also be simulated by
      powering down slots via sysfs.  The bug is particularly easy to trigger
      in poll mode.
      
      It has been present since the driver's introduction in 2004:
      https://git.kernel.org/tglx/history/c/c16b4b14d980
      
      Fix by rearranging teardown such that the IRQ is freed first.  Run the
      work items queued by the IRQ handler to completion before freeing the
      hotplug_slot struct by draining the work queue from the ->release_slot
      callback which is invoked by pci_hp_deregister().
      Signed-off-by: default avatarLukas Wunner <lukas@wunner.de>
      Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
      Cc: stable@vger.kernel.org # v2.6.4
      281e878e
    • Lukas Wunner's avatar
      PCI: hotplug: Don't leak pci_slot on registration failure · 4ce64358
      Lukas Wunner authored
      If addition of sysfs files fails on registration of a hotplug slot, the
      struct pci_slot as well as the entry in the slot_list is leaked.  The
      issue has been present since the hotplug core was introduced in 2002:
      https://git.kernel.org/tglx/history/c/a8a2069f432c
      
      Perhaps the idea was that even though sysfs addition fails, the slot
      should still be usable.  But that's not how drivers use the interface,
      they abort probe if a non-zero value is returned.
      Signed-off-by: default avatarLukas Wunner <lukas@wunner.de>
      Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
      Cc: stable@vger.kernel.org # v2.4.15+
      Cc: Greg Kroah-Hartman <greg@kroah.com>
      4ce64358
    • Lukas Wunner's avatar
      PCI: hotplug: Delete skeleton driver · b4efce5c
      Lukas Wunner authored
      Ten years ago, commit 58319b80 ("PCI: Hotplug core: remove 'name'")
      dropped the name element from struct hotplug_slot but neglected to update
      the skeleton driver.
      
      That same year, commit f46753c5 ("PCI: introduce pci_slot") raised the
      number of arguments to pci_hp_register() from one to four.
      
      Fourteen years ago, historic commit 7ab60fc1 ("PCI Hotplug skeleton:
      final cleanups") removed all usages of the retval variable from
      pcihp_skel_init() but not the variable itself, provoking a compiler
      warning: https://git.kernel.org/tglx/history/c/7ab60fc1b8e7
      
      It seems fair to assume the driver hasn't been used as a template for a new
      driver in a while.  Per Bjorn's and Christoph's preference, delete it.
      Signed-off-by: default avatarLukas Wunner <lukas@wunner.de>
      Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
      Cc: Christoph Hellwig <hch@lst.de>
      b4efce5c
  2. 26 Jun, 2018 2 commits
  3. 16 Jun, 2018 8 commits
    • Linus Torvalds's avatar
      Linux 4.18-rc1 · ce397d21
      Linus Torvalds authored
      ce397d21
    • Linus Torvalds's avatar
      Merge tag 'for-linus-20180616' of git://git.kernel.dk/linux-block · 265c5596
      Linus Torvalds authored
      Pull block fixes from Jens Axboe:
       "A collection of fixes that should go into -rc1. This contains:
      
         - bsg_open vs bsg_unregister race fix (Anatoliy)
      
         - NVMe pull request from Christoph, with fixes for regressions in
           this window, FC connect/reconnect path code unification, and a
           trace point addition.
      
         - timeout fix (Christoph)
      
         - remove a few unused functions (Christoph)
      
         - blk-mq tag_set reinit fix (Roman)"
      
      * tag 'for-linus-20180616' of git://git.kernel.dk/linux-block:
        bsg: fix race of bsg_open and bsg_unregister
        block: remov blk_queue_invalidate_tags
        nvme-fabrics: fix and refine state checks in __nvmf_check_ready
        nvme-fabrics: handle the admin-only case properly in nvmf_check_ready
        nvme-fabrics: refactor queue ready check
        blk-mq: remove blk_mq_tagset_iter
        nvme: remove nvme_reinit_tagset
        nvme-fc: fix nulling of queue data on reconnect
        nvme-fc: remove reinit_request routine
        blk-mq: don't time out requests again that are in the timeout handler
        nvme-fc: change controllers first connect to use reconnect path
        nvme: don't rely on the changed namespace list log
        nvmet: free smart-log buffer after use
        nvme-rdma: fix error flow during mapping request data
        nvme: add bio remapping tracepoint
        nvme: fix NULL pointer dereference in nvme_init_subsystem
        blk-mq: reinit q->tag_set_list entry only after grace period
      265c5596
    • Linus Torvalds's avatar
      Merge tag 'docs-broken-links' of git://linuxtv.org/mchehab/experimental · 5e7b9212
      Linus Torvalds authored
      Pull documentation fixes from Mauro Carvalho Chehab:
       "This solves a series of broken links for files under Documentation,
        and improves a script meant to detect such broken links (see
        scripts/documentation-file-ref-check).
      
        The changes on this series are:
      
         - can.rst: fix a footnote reference;
      
         - crypto_engine.rst: Fix two parsing warnings;
      
         - Fix a lot of broken references to Documentation/*;
      
         - improve the scripts/documentation-file-ref-check script, in order
           to help detecting/fixing broken references, preventing
           false-positives.
      
        After this patch series, only 33 broken references to doc files are
        detected by scripts/documentation-file-ref-check"
      
      * tag 'docs-broken-links' of git://linuxtv.org/mchehab/experimental: (26 commits)
        fix a series of Documentation/ broken file name references
        Documentation: rstFlatTable.py: fix a broken reference
        ABI: sysfs-devices-system-cpu: remove a broken reference
        devicetree: fix a series of wrong file references
        devicetree: fix name of pinctrl-bindings.txt
        devicetree: fix some bindings file names
        MAINTAINERS: fix location of DT npcm files
        MAINTAINERS: fix location of some display DT bindings
        kernel-parameters.txt: fix pointers to sound parameters
        bindings: nvmem/zii: Fix location of nvmem.txt
        docs: Fix more broken references
        scripts/documentation-file-ref-check: check tools/*/Documentation
        scripts/documentation-file-ref-check: get rid of false-positives
        scripts/documentation-file-ref-check: hint: dash or underline
        scripts/documentation-file-ref-check: add a fix logic for DT
        scripts/documentation-file-ref-check: accept more wildcards at filenames
        scripts/documentation-file-ref-check: fix help message
        media: max2175: fix location of driver's companion documentation
        media: v4l: fix broken video4linux docs locations
        media: dvb: point to the location of the old README.dvb-usb file
        ...
      5e7b9212
    • Linus Torvalds's avatar
      Merge tag 'fsnotify_for_v4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs · dbb2816f
      Linus Torvalds authored
      Pull fsnotify updates from Jan Kara:
       "fsnotify cleanups unifying handling of different watch types.
      
        This is the shortened fsnotify series from Amir with the last five
        patches pulled out. Amir has modified those patches to not change
        struct inode but obviously it's too late for those to go into this
        merge window"
      
      * tag 'fsnotify_for_v4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
        fsnotify: add fsnotify_add_inode_mark() wrappers
        fanotify: generalize fanotify_should_send_event()
        fsnotify: generalize send_to_group()
        fsnotify: generalize iteration of marks by object type
        fsnotify: introduce marks iteration helpers
        fsnotify: remove redundant arguments to handle_event()
        fsnotify: use type id to identify connector object type
      dbb2816f
    • Linus Torvalds's avatar
      Merge tag 'fbdev-v4.18' of git://github.com/bzolnier/linux · 644f2639
      Linus Torvalds authored
      Pull fbdev updates from Bartlomiej Zolnierkiewicz:
       "There is nothing really major here, few small fixes, some cleanups and
        dead drivers removal:
      
         - mark omapfb drivers as orphans in MAINTAINERS file (Tomi Valkeinen)
      
         - add missing module license tags to omap/omapfb driver (Arnd
           Bergmann)
      
         - add missing GPIOLIB dependendy to omap2/omapfb driver (Arnd
           Bergmann)
      
         - convert savagefb, aty128fb & radeonfb drivers to use msleep & co.
           (Jia-Ju Bai)
      
         - allow COMPILE_TEST build for viafb driver (media part was reviewed
           by media subsystem Maintainer)
      
         - remove unused MERAM support from sh_mobile_lcdcfb and shmob-drm
           drivers (drm parts were acked by shmob-drm driver Maintainer)
      
         - remove unused auo_k190xfb drivers
      
         - misc cleanups (Souptick Joarder, Wolfram Sang, Markus Elfring, Andy
           Shevchenko, Colin Ian King)"
      
      * tag 'fbdev-v4.18' of git://github.com/bzolnier/linux: (26 commits)
        fb_omap2: add gpiolib dependency
        video/omap: add module license tags
        MAINTAINERS: make omapfb orphan
        video: fbdev: pxafb: match_string() conversion fixup
        video: fbdev: nvidia: fix spelling mistake: "scaleing" -> "scaling"
        video: fbdev: fix spelling mistake: "frambuffer" -> "framebuffer"
        video: fbdev: pxafb: Convert to use match_string() helper
        video: fbdev: via: allow COMPILE_TEST build
        video: fbdev: remove unused sh_mobile_meram driver
        drm: shmobile: remove unused MERAM support
        video: fbdev: sh_mobile_lcdcfb: remove unused MERAM support
        video: fbdev: remove unused auo_k190xfb drivers
        video: omap: Improve a size determination in omapfb_do_probe()
        video: sm501fb: Improve a size determination in sm501fb_probe()
        video: fbdev-MMP: Improve a size determination in path_init()
        video: fbdev-MMP: Delete an error message for a failed memory allocation in two functions
        video: auo_k190x: Delete an error message for a failed memory allocation in auok190x_common_probe()
        video: sh_mobile_lcdcfb: Delete an error message for a failed memory allocation in two functions
        video: sh_mobile_meram: Delete an error message for a failed memory allocation in sh_mobile_meram_probe()
        video: fbdev: sh_mobile_meram: Drop SUPERH platform dependency
        ...
      644f2639
    • Linus Torvalds's avatar
      Merge branch 'afs-proc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs · 35773c93
      Linus Torvalds authored
      Pull AFS updates from Al Viro:
       "Assorted AFS stuff - ended up in vfs.git since most of that consists
        of David's AFS-related followups to Christoph's procfs series"
      
      * 'afs-proc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
        afs: Optimise callback breaking by not repeating volume lookup
        afs: Display manually added cells in dynamic root mount
        afs: Enable IPv6 DNS lookups
        afs: Show all of a server's addresses in /proc/fs/afs/servers
        afs: Handle CONFIG_PROC_FS=n
        proc: Make inline name size calculation automatic
        afs: Implement network namespacing
        afs: Mark afs_net::ws_cell as __rcu and set using rcu functions
        afs: Fix a Sparse warning in xdr_decode_AFSFetchStatus()
        proc: Add a way to make network proc files writable
        afs: Rearrange fs/afs/proc.c to remove remaining predeclarations.
        afs: Rearrange fs/afs/proc.c to move the show routines up
        afs: Rearrange fs/afs/proc.c by moving fops and open functions down
        afs: Move /proc management functions to the end of the file
      35773c93
    • Linus Torvalds's avatar
      Merge branch 'work.compat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs · 29d6849d
      Linus Torvalds authored
      Pull compat updates from Al Viro:
       "Some biarch patches - getting rid of assorted (mis)uses of
        compat_alloc_user_space().
      
        Not much in that area this cycle..."
      
      * 'work.compat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
        orangefs: simplify compat ioctl handling
        signalfd: lift sigmask copyin and size checks to callers of do_signalfd4()
        vmsplice(): lift importing iovec into vmsplice(2) and compat counterpart
      29d6849d
    • Linus Torvalds's avatar
      Merge branch 'work.aio' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs · a5b729ea
      Linus Torvalds authored
      Pull aio fixes from Al Viro:
       "Assorted AIO followups and fixes"
      
      * 'work.aio' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
        eventpoll: switch to ->poll_mask
        aio: only return events requested in poll_mask() for IOCB_CMD_POLL
        eventfd: only return events requested in poll_mask()
        aio: mark __aio_sigset::sigmask const
      a5b729ea
  4. 15 Jun, 2018 21 commits