1. 19 Dec, 2018 1 commit
  2. 27 Nov, 2018 11 commits
  3. 25 Oct, 2018 2 commits
    • Wei Wang's avatar
      virtio-balloon: VIRTIO_BALLOON_F_PAGE_POISON · 2e991629
      Wei Wang authored
      The VIRTIO_BALLOON_F_PAGE_POISON feature bit is used to indicate if the
      guest is using page poisoning. Guest writes to the poison_val config
      field to tell host about the page poisoning value that is in use.
      Suggested-by: default avatarMichael S. Tsirkin <mst@redhat.com>
      Signed-off-by: default avatarWei Wang <wei.w.wang@intel.com>
      Cc: Michael S. Tsirkin <mst@redhat.com>
      Cc: Michal Hocko <mhocko@suse.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
      2e991629
    • Wei Wang's avatar
      virtio-balloon: VIRTIO_BALLOON_F_FREE_PAGE_HINT · 86a55978
      Wei Wang authored
      Negotiation of the VIRTIO_BALLOON_F_FREE_PAGE_HINT feature indicates the
      support of reporting hints of guest free pages to host via virtio-balloon.
      Currenlty, only free page blocks of MAX_ORDER - 1 are reported. They are
      obtained one by one from the mm free list via the regular allocation
      function.
      
      Host requests the guest to report free page hints by sending a new cmd id
      to the guest via the free_page_report_cmd_id configuration register. When
      the guest starts to report, it first sends a start cmd to host via the
      free page vq, which acks to host the cmd id received. When the guest
      finishes reporting free pages, a stop cmd is sent to host via the vq.
      Host may also send a stop cmd id to the guest to stop the reporting.
      
      VIRTIO_BALLOON_CMD_ID_STOP: Host sends this cmd to stop the guest
      reporting.
      VIRTIO_BALLOON_CMD_ID_DONE: Host sends this cmd to tell the guest that
      the reported pages are ready to be freed.
      
      Why does the guest free the reported pages when host tells it is ready to
      free?
      This is because freeing pages appears to be expensive for live migration.
      free_pages() dirties memory very quickly and makes the live migraion not
      converge in some cases. So it is good to delay the free_page operation
      when the migration is done, and host sends a command to guest about that.
      
      Why do we need the new VIRTIO_BALLOON_CMD_ID_DONE, instead of reusing
      VIRTIO_BALLOON_CMD_ID_STOP?
      This is because live migration is usually done in several rounds. At the
      end of each round, host needs to send a VIRTIO_BALLOON_CMD_ID_STOP cmd to
      the guest to stop (or say pause) the reporting. The guest resumes the
      reporting when it receives a new command id at the beginning of the next
      round. So we need a new cmd id to distinguish between "stop reporting" and
      "ready to free the reported pages".
      
      TODO:
      - Add a batch page allocation API to amortize the allocation overhead.
      Signed-off-by: default avatarWei Wang <wei.w.wang@intel.com>
      Signed-off-by: default avatarLiang Li <liang.z.li@intel.com>
      Cc: Michael S. Tsirkin <mst@redhat.com>
      Cc: Michal Hocko <mhocko@kernel.org>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
      86a55978
  4. 21 Aug, 2018 5 commits
    • Suzuki K Poulose's avatar
      virtio: pci-legacy: Validate queue pfn · 69599206
      Suzuki K Poulose authored
      Legacy PCI over virtio uses a 32bit PFN for the queue. If the
      queue pfn is too large to fit in 32bits, which we could hit on
      arm64 systems with 52bit physical addresses (even with 64K page
      size), we simply miss out a proper link to the other side of
      the queue.
      
      Add a check to validate the PFN, rather than silently breaking
      the devices.
      
      Cc: "Michael S. Tsirkin" <mst@redhat.com>
      Cc: Jason Wang <jasowang@redhat.com>
      Cc: Marc Zyngier <marc.zyngier@arm.com>
      Cc: Christoffer Dall <cdall@kernel.org>
      Cc: Peter Maydel <peter.maydell@linaro.org>
      Cc: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
      Signed-off-by: default avatarSuzuki K Poulose <suzuki.poulose@arm.com>
      Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
      69599206
    • Suzuki K Poulose's avatar
      virtio: mmio-v1: Validate queue PFN · 3fc92a96
      Suzuki K Poulose authored
      virtio-mmio with virtio-v1 uses a 32bit PFN for the queue.
      If the queue pfn is too large to fit in 32bits, which
      we could hit on arm64 systems with 52bit physical addresses
      (even with 64K page size), we simply miss out a proper link
      to the other side of the queue.
      
      Add a check to validate the PFN, rather than silently breaking
      the devices.
      
      Cc: "Michael S. Tsirkin" <mst@redhat.com>
      Cc: Jason Wang <jasowang@redhat.com>
      Cc: Marc Zyngier <marc.zyngier@arm.com>
      Cc: Christoffer Dall <cdall@kernel.org>
      Cc: Peter Maydel <peter.maydell@linaro.org>
      Cc: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
      Signed-off-by: default avatarSuzuki K Poulose <suzuki.poulose@arm.com>
      Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
      3fc92a96
    • Wei Wang's avatar
      virtio_balloon: replace oom notifier with shrinker · 71994620
      Wei Wang authored
      The OOM notifier is getting deprecated to use for the reasons:
      - As a callout from the oom context, it is too subtle and easy to
        generate bugs and corner cases which are hard to track;
      - It is called too late (after the reclaiming has been performed).
        Drivers with large amuont of reclaimable memory is expected to
        release them at an early stage of memory pressure;
      - The notifier callback isn't aware of oom contrains;
      Link: https://lkml.org/lkml/2018/7/12/314
      
      This patch replaces the virtio-balloon oom notifier with a shrinker
      to release balloon pages on memory pressure. The balloon pages are
      given back to mm adaptively by returning the number of pages that the
      reclaimer is asking for (i.e. sc->nr_to_scan).
      
      Currently the max possible value of sc->nr_to_scan passed to the balloon
      shrinker is SHRINK_BATCH, which is 128. This is smaller than the
      limitation that only VIRTIO_BALLOON_ARRAY_PFNS_MAX (256) pages can be
      returned via one invocation of leak_balloon. But this patch still
      considers the case that SHRINK_BATCH or shrinker->batch could be changed
      to a value larger than VIRTIO_BALLOON_ARRAY_PFNS_MAX, which will need to
      do multiple invocations of leak_balloon.
      
      Historically, the feature VIRTIO_BALLOON_F_DEFLATE_ON_OOM has been used
      to release balloon pages on OOM. We continue to use this feature bit for
      the shrinker, so the shrinker is only registered when this feature bit
      has been negotiated with host.
      Signed-off-by: default avatarWei Wang <wei.w.wang@intel.com>
      Cc: Michael S. Tsirkin <mst@redhat.com>
      Cc: Michal Hocko <mhocko@kernel.org>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
      Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
      71994620
    • Wei Wang's avatar
      virtio-balloon: kzalloc the vb struct · c51d8fca
      Wei Wang authored
      Zero all the vb fields at alloaction, so that we don't need to
      zero-initialize each field one by one later.
      Signed-off-by: default avatarWei Wang <wei.w.wang@intel.com>
      Cc: Michael S. Tsirkin <mst@redhat.com>
      Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
      Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
      c51d8fca
    • Wei Wang's avatar
      virtio-balloon: remove BUG() in init_vqs · 74cf5b16
      Wei Wang authored
      It's a bit overkill to use BUG when failing to add an entry to the
      stats_vq in init_vqs. So remove it and just return the error to the
      caller to bail out nicely.
      Signed-off-by: default avatarWei Wang <wei.w.wang@intel.com>
      Cc: Michael S. Tsirkin <mst@redhat.com>
      Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
      74cf5b16
  5. 11 Aug, 2018 1 commit
  6. 30 Jul, 2018 1 commit
    • Jiang Biao's avatar
      virtio_balloon: fix another race between migration and ballooning · 89da619b
      Jiang Biao authored
      Kernel panic when with high memory pressure, calltrace looks like,
      
      PID: 21439 TASK: ffff881be3afedd0 CPU: 16 COMMAND: "java"
       #0 [ffff881ec7ed7630] machine_kexec at ffffffff81059beb
       #1 [ffff881ec7ed7690] __crash_kexec at ffffffff81105942
       #2 [ffff881ec7ed7760] crash_kexec at ffffffff81105a30
       #3 [ffff881ec7ed7778] oops_end at ffffffff816902c8
       #4 [ffff881ec7ed77a0] no_context at ffffffff8167ff46
       #5 [ffff881ec7ed77f0] __bad_area_nosemaphore at ffffffff8167ffdc
       #6 [ffff881ec7ed7838] __node_set at ffffffff81680300
       #7 [ffff881ec7ed7860] __do_page_fault at ffffffff8169320f
       #8 [ffff881ec7ed78c0] do_page_fault at ffffffff816932b5
       #9 [ffff881ec7ed78f0] page_fault at ffffffff8168f4c8
          [exception RIP: _raw_spin_lock_irqsave+47]
          RIP: ffffffff8168edef RSP: ffff881ec7ed79a8 RFLAGS: 00010046
          RAX: 0000000000000246 RBX: ffffea0019740d00 RCX: ffff881ec7ed7fd8
          RDX: 0000000000020000 RSI: 0000000000000016 RDI: 0000000000000008
          RBP: ffff881ec7ed79a8 R8: 0000000000000246 R9: 000000000001a098
          R10: ffff88107ffda000 R11: 0000000000000000 R12: 0000000000000000
          R13: 0000000000000008 R14: ffff881ec7ed7a80 R15: ffff881be3afedd0
          ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018
      
      It happens in the pagefault and results in double pagefault
      during compacting pages when memory allocation fails.
      
      Analysed the vmcore, the page leads to second pagefault is corrupted
      with _mapcount=-256, but private=0.
      
      It's caused by the race between migration and ballooning, and lock
      missing in virtballoon_migratepage() of virtio_balloon driver.
      This patch fix the bug.
      
      Fixes: e2250429 ("virtio_balloon: introduce migration primitives to balloon pages")
      Cc: stable@vger.kernel.org
      Signed-off-by: default avatarJiang Biao <jiang.biao2@zte.com.cn>
      Signed-off-by: default avatarHuang Chong <huang.chong@zte.com.cn>
      Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
      89da619b
  7. 12 Jun, 2018 3 commits
    • Kees Cook's avatar
      treewide: kzalloc() -> kcalloc() · 6396bb22
      Kees Cook authored
      The kzalloc() function has a 2-factor argument form, kcalloc(). This
      patch replaces cases of:
      
              kzalloc(a * b, gfp)
      
      with:
              kcalloc(a * b, gfp)
      
      as well as handling cases of:
      
              kzalloc(a * b * c, gfp)
      
      with:
      
              kzalloc(array3_size(a, b, c), gfp)
      
      as it's slightly less ugly than:
      
              kzalloc_array(array_size(a, b), c, gfp)
      
      This does, however, attempt to ignore constant size factors like:
      
              kzalloc(4 * 1024, gfp)
      
      though any constants defined via macros get caught up in the conversion.
      
      Any factors with a sizeof() of "unsigned char", "char", and "u8" were
      dropped, since they're redundant.
      
      The Coccinelle script used for this was:
      
      // Fix redundant parens around sizeof().
      @@
      type TYPE;
      expression THING, E;
      @@
      
      (
        kzalloc(
      -	(sizeof(TYPE)) * E
      +	sizeof(TYPE) * E
        , ...)
      |
        kzalloc(
      -	(sizeof(THING)) * E
      +	sizeof(THING) * E
        , ...)
      )
      
      // Drop single-byte sizes and redundant parens.
      @@
      expression COUNT;
      typedef u8;
      typedef __u8;
      @@
      
      (
        kzalloc(
      -	sizeof(u8) * (COUNT)
      +	COUNT
        , ...)
      |
        kzalloc(
      -	sizeof(__u8) * (COUNT)
      +	COUNT
        , ...)
      |
        kzalloc(
      -	sizeof(char) * (COUNT)
      +	COUNT
        , ...)
      |
        kzalloc(
      -	sizeof(unsigned char) * (COUNT)
      +	COUNT
        , ...)
      |
        kzalloc(
      -	sizeof(u8) * COUNT
      +	COUNT
        , ...)
      |
        kzalloc(
      -	sizeof(__u8) * COUNT
      +	COUNT
        , ...)
      |
        kzalloc(
      -	sizeof(char) * COUNT
      +	COUNT
        , ...)
      |
        kzalloc(
      -	sizeof(unsigned char) * COUNT
      +	COUNT
        , ...)
      )
      
      // 2-factor product with sizeof(type/expression) and identifier or constant.
      @@
      type TYPE;
      expression THING;
      identifier COUNT_ID;
      constant COUNT_CONST;
      @@
      
      (
      - kzalloc
      + kcalloc
        (
      -	sizeof(TYPE) * (COUNT_ID)
      +	COUNT_ID, sizeof(TYPE)
        , ...)
      |
      - kzalloc
      + kcalloc
        (
      -	sizeof(TYPE) * COUNT_ID
      +	COUNT_ID, sizeof(TYPE)
        , ...)
      |
      - kzalloc
      + kcalloc
        (
      -	sizeof(TYPE) * (COUNT_CONST)
      +	COUNT_CONST, sizeof(TYPE)
        , ...)
      |
      - kzalloc
      + kcalloc
        (
      -	sizeof(TYPE) * COUNT_CONST
      +	COUNT_CONST, sizeof(TYPE)
        , ...)
      |
      - kzalloc
      + kcalloc
        (
      -	sizeof(THING) * (COUNT_ID)
      +	COUNT_ID, sizeof(THING)
        , ...)
      |
      - kzalloc
      + kcalloc
        (
      -	sizeof(THING) * COUNT_ID
      +	COUNT_ID, sizeof(THING)
        , ...)
      |
      - kzalloc
      + kcalloc
        (
      -	sizeof(THING) * (COUNT_CONST)
      +	COUNT_CONST, sizeof(THING)
        , ...)
      |
      - kzalloc
      + kcalloc
        (
      -	sizeof(THING) * COUNT_CONST
      +	COUNT_CONST, sizeof(THING)
        , ...)
      )
      
      // 2-factor product, only identifiers.
      @@
      identifier SIZE, COUNT;
      @@
      
      - kzalloc
      + kcalloc
        (
      -	SIZE * COUNT
      +	COUNT, SIZE
        , ...)
      
      // 3-factor product with 1 sizeof(type) or sizeof(expression), with
      // redundant parens removed.
      @@
      expression THING;
      identifier STRIDE, COUNT;
      type TYPE;
      @@
      
      (
        kzalloc(
      -	sizeof(TYPE) * (COUNT) * (STRIDE)
      +	array3_size(COUNT, STRIDE, sizeof(TYPE))
        , ...)
      |
        kzalloc(
      -	sizeof(TYPE) * (COUNT) * STRIDE
      +	array3_size(COUNT, STRIDE, sizeof(TYPE))
        , ...)
      |
        kzalloc(
      -	sizeof(TYPE) * COUNT * (STRIDE)
      +	array3_size(COUNT, STRIDE, sizeof(TYPE))
        , ...)
      |
        kzalloc(
      -	sizeof(TYPE) * COUNT * STRIDE
      +	array3_size(COUNT, STRIDE, sizeof(TYPE))
        , ...)
      |
        kzalloc(
      -	sizeof(THING) * (COUNT) * (STRIDE)
      +	array3_size(COUNT, STRIDE, sizeof(THING))
        , ...)
      |
        kzalloc(
      -	sizeof(THING) * (COUNT) * STRIDE
      +	array3_size(COUNT, STRIDE, sizeof(THING))
        , ...)
      |
        kzalloc(
      -	sizeof(THING) * COUNT * (STRIDE)
      +	array3_size(COUNT, STRIDE, sizeof(THING))
        , ...)
      |
        kzalloc(
      -	sizeof(THING) * COUNT * STRIDE
      +	array3_size(COUNT, STRIDE, sizeof(THING))
        , ...)
      )
      
      // 3-factor product with 2 sizeof(variable), with redundant parens removed.
      @@
      expression THING1, THING2;
      identifier COUNT;
      type TYPE1, TYPE2;
      @@
      
      (
        kzalloc(
      -	sizeof(TYPE1) * sizeof(TYPE2) * COUNT
      +	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
        , ...)
      |
        kzalloc(
      -	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
      +	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
        , ...)
      |
        kzalloc(
      -	sizeof(THING1) * sizeof(THING2) * COUNT
      +	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
        , ...)
      |
        kzalloc(
      -	sizeof(THING1) * sizeof(THING2) * (COUNT)
      +	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
        , ...)
      |
        kzalloc(
      -	sizeof(TYPE1) * sizeof(THING2) * COUNT
      +	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
        , ...)
      |
        kzalloc(
      -	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
      +	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
        , ...)
      )
      
      // 3-factor product, only identifiers, with redundant parens removed.
      @@
      identifier STRIDE, SIZE, COUNT;
      @@
      
      (
        kzalloc(
      -	(COUNT) * STRIDE * SIZE
      +	array3_size(COUNT, STRIDE, SIZE)
        , ...)
      |
        kzalloc(
      -	COUNT * (STRIDE) * SIZE
      +	array3_size(COUNT, STRIDE, SIZE)
        , ...)
      |
        kzalloc(
      -	COUNT * STRIDE * (SIZE)
      +	array3_size(COUNT, STRIDE, SIZE)
        , ...)
      |
        kzalloc(
      -	(COUNT) * (STRIDE) * SIZE
      +	array3_size(COUNT, STRIDE, SIZE)
        , ...)
      |
        kzalloc(
      -	COUNT * (STRIDE) * (SIZE)
      +	array3_size(COUNT, STRIDE, SIZE)
        , ...)
      |
        kzalloc(
      -	(COUNT) * STRIDE * (SIZE)
      +	array3_size(COUNT, STRIDE, SIZE)
        , ...)
      |
        kzalloc(
      -	(COUNT) * (STRIDE) * (SIZE)
      +	array3_size(COUNT, STRIDE, SIZE)
        , ...)
      |
        kzalloc(
      -	COUNT * STRIDE * SIZE
      +	array3_size(COUNT, STRIDE, SIZE)
        , ...)
      )
      
      // Any remaining multi-factor products, first at least 3-factor products,
      // when they're not all constants...
      @@
      expression E1, E2, E3;
      constant C1, C2, C3;
      @@
      
      (
        kzalloc(C1 * C2 * C3, ...)
      |
        kzalloc(
      -	(E1) * E2 * E3
      +	array3_size(E1, E2, E3)
        , ...)
      |
        kzalloc(
      -	(E1) * (E2) * E3
      +	array3_size(E1, E2, E3)
        , ...)
      |
        kzalloc(
      -	(E1) * (E2) * (E3)
      +	array3_size(E1, E2, E3)
        , ...)
      |
        kzalloc(
      -	E1 * E2 * E3
      +	array3_size(E1, E2, E3)
        , ...)
      )
      
      // And then all remaining 2 factors products when they're not all constants,
      // keeping sizeof() as the second factor argument.
      @@
      expression THING, E1, E2;
      type TYPE;
      constant C1, C2, C3;
      @@
      
      (
        kzalloc(sizeof(THING) * C2, ...)
      |
        kzalloc(sizeof(TYPE) * C2, ...)
      |
        kzalloc(C1 * C2 * C3, ...)
      |
        kzalloc(C1 * C2, ...)
      |
      - kzalloc
      + kcalloc
        (
      -	sizeof(TYPE) * (E2)
      +	E2, sizeof(TYPE)
        , ...)
      |
      - kzalloc
      + kcalloc
        (
      -	sizeof(TYPE) * E2
      +	E2, sizeof(TYPE)
        , ...)
      |
      - kzalloc
      + kcalloc
        (
      -	sizeof(THING) * (E2)
      +	E2, sizeof(THING)
        , ...)
      |
      - kzalloc
      + kcalloc
        (
      -	sizeof(THING) * E2
      +	E2, sizeof(THING)
        , ...)
      |
      - kzalloc
      + kcalloc
        (
      -	(E1) * E2
      +	E1, E2
        , ...)
      |
      - kzalloc
      + kcalloc
        (
      -	(E1) * (E2)
      +	E1, E2
        , ...)
      |
      - kzalloc
      + kcalloc
        (
      -	E1 * E2
      +	E1, E2
        , ...)
      )
      Signed-off-by: default avatarKees Cook <keescook@chromium.org>
      6396bb22
    • Kees Cook's avatar
      treewide: kmalloc() -> kmalloc_array() · 6da2ec56
      Kees Cook authored
      The kmalloc() function has a 2-factor argument form, kmalloc_array(). This
      patch replaces cases of:
      
              kmalloc(a * b, gfp)
      
      with:
              kmalloc_array(a * b, gfp)
      
      as well as handling cases of:
      
              kmalloc(a * b * c, gfp)
      
      with:
      
              kmalloc(array3_size(a, b, c), gfp)
      
      as it's slightly less ugly than:
      
              kmalloc_array(array_size(a, b), c, gfp)
      
      This does, however, attempt to ignore constant size factors like:
      
              kmalloc(4 * 1024, gfp)
      
      though any constants defined via macros get caught up in the conversion.
      
      Any factors with a sizeof() of "unsigned char", "char", and "u8" were
      dropped, since they're redundant.
      
      The tools/ directory was manually excluded, since it has its own
      implementation of kmalloc().
      
      The Coccinelle script used for this was:
      
      // Fix redundant parens around sizeof().
      @@
      type TYPE;
      expression THING, E;
      @@
      
      (
        kmalloc(
      -	(sizeof(TYPE)) * E
      +	sizeof(TYPE) * E
        , ...)
      |
        kmalloc(
      -	(sizeof(THING)) * E
      +	sizeof(THING) * E
        , ...)
      )
      
      // Drop single-byte sizes and redundant parens.
      @@
      expression COUNT;
      typedef u8;
      typedef __u8;
      @@
      
      (
        kmalloc(
      -	sizeof(u8) * (COUNT)
      +	COUNT
        , ...)
      |
        kmalloc(
      -	sizeof(__u8) * (COUNT)
      +	COUNT
        , ...)
      |
        kmalloc(
      -	sizeof(char) * (COUNT)
      +	COUNT
        , ...)
      |
        kmalloc(
      -	sizeof(unsigned char) * (COUNT)
      +	COUNT
        , ...)
      |
        kmalloc(
      -	sizeof(u8) * COUNT
      +	COUNT
        , ...)
      |
        kmalloc(
      -	sizeof(__u8) * COUNT
      +	COUNT
        , ...)
      |
        kmalloc(
      -	sizeof(char) * COUNT
      +	COUNT
        , ...)
      |
        kmalloc(
      -	sizeof(unsigned char) * COUNT
      +	COUNT
        , ...)
      )
      
      // 2-factor product with sizeof(type/expression) and identifier or constant.
      @@
      type TYPE;
      expression THING;
      identifier COUNT_ID;
      constant COUNT_CONST;
      @@
      
      (
      - kmalloc
      + kmalloc_array
        (
      -	sizeof(TYPE) * (COUNT_ID)
      +	COUNT_ID, sizeof(TYPE)
        , ...)
      |
      - kmalloc
      + kmalloc_array
        (
      -	sizeof(TYPE) * COUNT_ID
      +	COUNT_ID, sizeof(TYPE)
        , ...)
      |
      - kmalloc
      + kmalloc_array
        (
      -	sizeof(TYPE) * (COUNT_CONST)
      +	COUNT_CONST, sizeof(TYPE)
        , ...)
      |
      - kmalloc
      + kmalloc_array
        (
      -	sizeof(TYPE) * COUNT_CONST
      +	COUNT_CONST, sizeof(TYPE)
        , ...)
      |
      - kmalloc
      + kmalloc_array
        (
      -	sizeof(THING) * (COUNT_ID)
      +	COUNT_ID, sizeof(THING)
        , ...)
      |
      - kmalloc
      + kmalloc_array
        (
      -	sizeof(THING) * COUNT_ID
      +	COUNT_ID, sizeof(THING)
        , ...)
      |
      - kmalloc
      + kmalloc_array
        (
      -	sizeof(THING) * (COUNT_CONST)
      +	COUNT_CONST, sizeof(THING)
        , ...)
      |
      - kmalloc
      + kmalloc_array
        (
      -	sizeof(THING) * COUNT_CONST
      +	COUNT_CONST, sizeof(THING)
        , ...)
      )
      
      // 2-factor product, only identifiers.
      @@
      identifier SIZE, COUNT;
      @@
      
      - kmalloc
      + kmalloc_array
        (
      -	SIZE * COUNT
      +	COUNT, SIZE
        , ...)
      
      // 3-factor product with 1 sizeof(type) or sizeof(expression), with
      // redundant parens removed.
      @@
      expression THING;
      identifier STRIDE, COUNT;
      type TYPE;
      @@
      
      (
        kmalloc(
      -	sizeof(TYPE) * (COUNT) * (STRIDE)
      +	array3_size(COUNT, STRIDE, sizeof(TYPE))
        , ...)
      |
        kmalloc(
      -	sizeof(TYPE) * (COUNT) * STRIDE
      +	array3_size(COUNT, STRIDE, sizeof(TYPE))
        , ...)
      |
        kmalloc(
      -	sizeof(TYPE) * COUNT * (STRIDE)
      +	array3_size(COUNT, STRIDE, sizeof(TYPE))
        , ...)
      |
        kmalloc(
      -	sizeof(TYPE) * COUNT * STRIDE
      +	array3_size(COUNT, STRIDE, sizeof(TYPE))
        , ...)
      |
        kmalloc(
      -	sizeof(THING) * (COUNT) * (STRIDE)
      +	array3_size(COUNT, STRIDE, sizeof(THING))
        , ...)
      |
        kmalloc(
      -	sizeof(THING) * (COUNT) * STRIDE
      +	array3_size(COUNT, STRIDE, sizeof(THING))
        , ...)
      |
        kmalloc(
      -	sizeof(THING) * COUNT * (STRIDE)
      +	array3_size(COUNT, STRIDE, sizeof(THING))
        , ...)
      |
        kmalloc(
      -	sizeof(THING) * COUNT * STRIDE
      +	array3_size(COUNT, STRIDE, sizeof(THING))
        , ...)
      )
      
      // 3-factor product with 2 sizeof(variable), with redundant parens removed.
      @@
      expression THING1, THING2;
      identifier COUNT;
      type TYPE1, TYPE2;
      @@
      
      (
        kmalloc(
      -	sizeof(TYPE1) * sizeof(TYPE2) * COUNT
      +	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
        , ...)
      |
        kmalloc(
      -	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
      +	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
        , ...)
      |
        kmalloc(
      -	sizeof(THING1) * sizeof(THING2) * COUNT
      +	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
        , ...)
      |
        kmalloc(
      -	sizeof(THING1) * sizeof(THING2) * (COUNT)
      +	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
        , ...)
      |
        kmalloc(
      -	sizeof(TYPE1) * sizeof(THING2) * COUNT
      +	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
        , ...)
      |
        kmalloc(
      -	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
      +	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
        , ...)
      )
      
      // 3-factor product, only identifiers, with redundant parens removed.
      @@
      identifier STRIDE, SIZE, COUNT;
      @@
      
      (
        kmalloc(
      -	(COUNT) * STRIDE * SIZE
      +	array3_size(COUNT, STRIDE, SIZE)
        , ...)
      |
        kmalloc(
      -	COUNT * (STRIDE) * SIZE
      +	array3_size(COUNT, STRIDE, SIZE)
        , ...)
      |
        kmalloc(
      -	COUNT * STRIDE * (SIZE)
      +	array3_size(COUNT, STRIDE, SIZE)
        , ...)
      |
        kmalloc(
      -	(COUNT) * (STRIDE) * SIZE
      +	array3_size(COUNT, STRIDE, SIZE)
        , ...)
      |
        kmalloc(
      -	COUNT * (STRIDE) * (SIZE)
      +	array3_size(COUNT, STRIDE, SIZE)
        , ...)
      |
        kmalloc(
      -	(COUNT) * STRIDE * (SIZE)
      +	array3_size(COUNT, STRIDE, SIZE)
        , ...)
      |
        kmalloc(
      -	(COUNT) * (STRIDE) * (SIZE)
      +	array3_size(COUNT, STRIDE, SIZE)
        , ...)
      |
        kmalloc(
      -	COUNT * STRIDE * SIZE
      +	array3_size(COUNT, STRIDE, SIZE)
        , ...)
      )
      
      // Any remaining multi-factor products, first at least 3-factor products,
      // when they're not all constants...
      @@
      expression E1, E2, E3;
      constant C1, C2, C3;
      @@
      
      (
        kmalloc(C1 * C2 * C3, ...)
      |
        kmalloc(
      -	(E1) * E2 * E3
      +	array3_size(E1, E2, E3)
        , ...)
      |
        kmalloc(
      -	(E1) * (E2) * E3
      +	array3_size(E1, E2, E3)
        , ...)
      |
        kmalloc(
      -	(E1) * (E2) * (E3)
      +	array3_size(E1, E2, E3)
        , ...)
      |
        kmalloc(
      -	E1 * E2 * E3
      +	array3_size(E1, E2, E3)
        , ...)
      )
      
      // And then all remaining 2 factors products when they're not all constants,
      // keeping sizeof() as the second factor argument.
      @@
      expression THING, E1, E2;
      type TYPE;
      constant C1, C2, C3;
      @@
      
      (
        kmalloc(sizeof(THING) * C2, ...)
      |
        kmalloc(sizeof(TYPE) * C2, ...)
      |
        kmalloc(C1 * C2 * C3, ...)
      |
        kmalloc(C1 * C2, ...)
      |
      - kmalloc
      + kmalloc_array
        (
      -	sizeof(TYPE) * (E2)
      +	E2, sizeof(TYPE)
        , ...)
      |
      - kmalloc
      + kmalloc_array
        (
      -	sizeof(TYPE) * E2
      +	E2, sizeof(TYPE)
        , ...)
      |
      - kmalloc
      + kmalloc_array
        (
      -	sizeof(THING) * (E2)
      +	E2, sizeof(THING)
        , ...)
      |
      - kmalloc
      + kmalloc_array
        (
      -	sizeof(THING) * E2
      +	E2, sizeof(THING)
        , ...)
      |
      - kmalloc
      + kmalloc_array
        (
      -	(E1) * E2
      +	E1, E2
        , ...)
      |
      - kmalloc
      + kmalloc_array
        (
      -	(E1) * (E2)
      +	E1, E2
        , ...)
      |
      - kmalloc
      + kmalloc_array
        (
      -	E1 * E2
      +	E1, E2
        , ...)
      )
      Signed-off-by: default avatarKees Cook <keescook@chromium.org>
      6da2ec56
    • Tiwei Bie's avatar
      virtio_pci: support enabling VFs · cfecc291
      Tiwei Bie authored
      There is a new feature bit allocated in virtio spec to
      support SR-IOV (Single Root I/O Virtualization):
      
      https://github.com/oasis-tcs/virtio-spec/issues/11
      
      This patch enables the support for this feature bit in
      virtio driver.
      Signed-off-by: default avatarTiwei Bie <tiwei.bie@intel.com>
      Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
      cfecc291
  8. 10 Apr, 2018 1 commit
  9. 06 Apr, 2018 1 commit
    • Randy Dunlap's avatar
      headers: untangle kmemleak.h from mm.h · 514c6032
      Randy Dunlap authored
      Currently <linux/slab.h> #includes <linux/kmemleak.h> for no obvious
      reason.  It looks like it's only a convenience, so remove kmemleak.h
      from slab.h and add <linux/kmemleak.h> to any users of kmemleak_* that
      don't already #include it.  Also remove <linux/kmemleak.h> from source
      files that do not use it.
      
      This is tested on i386 allmodconfig and x86_64 allmodconfig.  It would
      be good to run it through the 0day bot for other $ARCHes.  I have
      neither the horsepower nor the storage space for the other $ARCHes.
      
      Update: This patch has been extensively build-tested by both the 0day
      bot & kisskb/ozlabs build farms.  Both of them reported 2 build failures
      for which patches are included here (in v2).
      
      [ slab.h is the second most used header file after module.h; kernel.h is
        right there with slab.h. There could be some minor error in the
        counting due to some #includes having comments after them and I didn't
        combine all of those. ]
      
      [akpm@linux-foundation.org: security/keys/big_key.c needs vmalloc.h, per sfr]
      Link: http://lkml.kernel.org/r/e4309f98-3749-93e1-4bb7-d9501a39d015@infradead.org
      Link: http://kisskb.ellerman.id.au/kisskb/head/13396/Signed-off-by: default avatarRandy Dunlap <rdunlap@infradead.org>
      Reviewed-by: default avatarIngo Molnar <mingo@kernel.org>
      Reported-by: Michael Ellerman <mpe@ellerman.id.au>	[2 build failures]
      Reported-by: Fengguang Wu <fengguang.wu@intel.com>	[2 build failures]
      Reviewed-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Cc: Wei Yongjun <weiyongjun1@huawei.com>
      Cc: Luis R. Rodriguez <mcgrof@kernel.org>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
      Cc: John Johansen <john.johansen@canonical.com>
      Cc: Stephen Rothwell <sfr@canb.auug.org.au>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      514c6032
  10. 01 Mar, 2018 1 commit
  11. 01 Feb, 2018 3 commits
  12. 30 Jan, 2018 3 commits
  13. 14 Dec, 2017 1 commit
    • Mark Rutland's avatar
      virtio_mmio: fix devm cleanup · c2e90800
      Mark Rutland authored
      Recent rework of the virtio_mmio probe/remove paths balanced a
      devm_ioremap() with an iounmap() rather than its devm variant. This ends
      up corrupting the devm datastructures, and results in the following
      boot-time splat on arm64 under QEMU 2.9.0:
      
      [    3.450397] ------------[ cut here ]------------
      [    3.453822] Trying to vfree() nonexistent vm area (00000000c05b4844)
      [    3.460534] WARNING: CPU: 1 PID: 1 at mm/vmalloc.c:1525 __vunmap+0x1b8/0x220
      [    3.475898] Kernel panic - not syncing: panic_on_warn set ...
      [    3.475898]
      [    3.493933] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 4.15.0-rc3 #1
      [    3.513109] Hardware name: linux,dummy-virt (DT)
      [    3.525382] Call trace:
      [    3.531683]  dump_backtrace+0x0/0x368
      [    3.543921]  show_stack+0x20/0x30
      [    3.547767]  dump_stack+0x108/0x164
      [    3.559584]  panic+0x25c/0x51c
      [    3.569184]  __warn+0x29c/0x31c
      [    3.576023]  report_bug+0x1d4/0x290
      [    3.586069]  bug_handler.part.2+0x40/0x100
      [    3.597820]  bug_handler+0x4c/0x88
      [    3.608400]  brk_handler+0x11c/0x218
      [    3.613430]  do_debug_exception+0xe8/0x318
      [    3.627370]  el1_dbg+0x18/0x78
      [    3.634037]  __vunmap+0x1b8/0x220
      [    3.648747]  vunmap+0x6c/0xc0
      [    3.653864]  __iounmap+0x44/0x58
      [    3.659771]  devm_ioremap_release+0x34/0x68
      [    3.672983]  release_nodes+0x404/0x880
      [    3.683543]  devres_release_all+0x6c/0xe8
      [    3.695692]  driver_probe_device+0x250/0x828
      [    3.706187]  __driver_attach+0x190/0x210
      [    3.717645]  bus_for_each_dev+0x14c/0x1f0
      [    3.728633]  driver_attach+0x48/0x78
      [    3.740249]  bus_add_driver+0x26c/0x5b8
      [    3.752248]  driver_register+0x16c/0x398
      [    3.757211]  __platform_driver_register+0xd8/0x128
      [    3.770860]  virtio_mmio_init+0x1c/0x24
      [    3.782671]  do_one_initcall+0xe0/0x398
      [    3.791890]  kernel_init_freeable+0x594/0x660
      [    3.798514]  kernel_init+0x18/0x190
      [    3.810220]  ret_from_fork+0x10/0x18
      
      To fix this, we can simply rip out the explicit cleanup that the devm
      infrastructure will do for us when our probe function returns an error
      code, or when our remove function returns.
      
      We only need to ensure that we call put_device() if a call to
      register_virtio_device() fails in the probe path.
      Signed-off-by: default avatarMark Rutland <mark.rutland@arm.com>
      Fixes: 7eb781b1 ("virtio_mmio: add cleanup for virtio_mmio_probe")
      Fixes: 25f32223 ("virtio_mmio: add cleanup for virtio_mmio_remove")
      Cc: Cornelia Huck <cohuck@redhat.com>
      Cc: Michael S. Tsirkin <mst@redhat.com>
      Cc: weiping zhang <zhangweiping@didichuxing.com>
      Cc: virtualization@lists.linux-foundation.org
      Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
      Reviewed-by: default avatarCornelia Huck <cohuck@redhat.com>
      c2e90800
  14. 07 Dec, 2017 2 commits
  15. 01 Dec, 2017 2 commits
  16. 14 Nov, 2017 1 commit
    • Michael S. Tsirkin's avatar
      virtio_balloon: fix deadlock on OOM · c7cdff0e
      Michael S. Tsirkin authored
      fill_balloon doing memory allocations under balloon_lock
      can cause a deadlock when leak_balloon is called from
      virtballoon_oom_notify and tries to take same lock.
      
      To fix, split page allocation and enqueue and do allocations outside the lock.
      
      Here's a detailed analysis of the deadlock by Tetsuo Handa:
      
      In leak_balloon(), mutex_lock(&vb->balloon_lock) is called in order to
      serialize against fill_balloon(). But in fill_balloon(),
      alloc_page(GFP_HIGHUSER[_MOVABLE] | __GFP_NOMEMALLOC | __GFP_NORETRY) is
      called with vb->balloon_lock mutex held. Since GFP_HIGHUSER[_MOVABLE]
      implies __GFP_DIRECT_RECLAIM | __GFP_IO | __GFP_FS, despite __GFP_NORETRY
      is specified, this allocation attempt might indirectly depend on somebody
      else's __GFP_DIRECT_RECLAIM memory allocation. And such indirect
      __GFP_DIRECT_RECLAIM memory allocation might call leak_balloon() via
      virtballoon_oom_notify() via blocking_notifier_call_chain() callback via
      out_of_memory() when it reached __alloc_pages_may_oom() and held oom_lock
      mutex. Since vb->balloon_lock mutex is already held by fill_balloon(), it
      will cause OOM lockup.
      
        Thread1                                       Thread2
          fill_balloon()
            takes a balloon_lock
            balloon_page_enqueue()
              alloc_page(GFP_HIGHUSER_MOVABLE)
                direct reclaim (__GFP_FS context)       takes a fs lock
                  waits for that fs lock                  alloc_page(GFP_NOFS)
                                                            __alloc_pages_may_oom()
                                                              takes the oom_lock
                                                              out_of_memory()
                                                                blocking_notifier_call_chain()
                                                                  leak_balloon()
                                                                    tries to take that balloon_lock and deadlocks
      Reported-by: default avatarTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
      Cc: Michal Hocko <mhocko@suse.com>
      Cc: Wei Wang <wei.w.wang@intel.com>
      Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
      c7cdff0e
  17. 02 Nov, 2017 1 commit
    • Greg Kroah-Hartman's avatar
      License cleanup: add SPDX GPL-2.0 license identifier to files with no license · b2441318
      Greg Kroah-Hartman authored
      Many source files in the tree are missing licensing information, which
      makes it harder for compliance tools to determine the correct license.
      
      By default all files without license information are under the default
      license of the kernel, which is GPL version 2.
      
      Update the files which contain no license information with the 'GPL-2.0'
      SPDX license identifier.  The SPDX identifier is a legally binding
      shorthand, which can be used instead of the full boiler plate text.
      
      This patch is based on work done by Thomas Gleixner and Kate Stewart and
      Philippe Ombredanne.
      
      How this work was done:
      
      Patches were generated and checked against linux-4.14-rc6 for a subset of
      the use cases:
       - file had no licensing information it it.
       - file was a */uapi/* one with no licensing information in it,
       - file was a */uapi/* one with existing licensing information,
      
      Further patches will be generated in subsequent months to fix up cases
      where non-standard license headers were used, and references to license
      had to be inferred by heuristics based on keywords.
      
      The analysis to determine which SPDX License Identifier to be applied to
      a file was done in a spreadsheet of side by side results from of the
      output of two independent scanners (ScanCode & Windriver) producing SPDX
      tag:value files created by Philippe Ombredanne.  Philippe prepared the
      base worksheet, and did an initial spot review of a few 1000 files.
      
      The 4.13 kernel was the starting point of the analysis with 60,537 files
      assessed.  Kate Stewart did a file by file comparison of the scanner
      results in the spreadsheet to determine which SPDX license identifier(s)
      to be applied to the file. She confirmed any determination that was not
      immediately clear with lawyers working with the Linux Foundation.
      
      Criteria used to select files for SPDX license identifier tagging was:
       - Files considered eligible had to be source code files.
       - Make and config files were included as candidates if they contained >5
         lines of source
       - File already had some variant of a license header in it (even if <5
         lines).
      
      All documentation files were explicitly excluded.
      
      The following heuristics were used to determine which SPDX license
      identifiers to apply.
      
       - when both scanners couldn't find any license traces, file was
         considered to have no license information in it, and the top level
         COPYING file license applied.
      
         For non */uapi/* files that summary was:
      
         SPDX license identifier                            # files
         ---------------------------------------------------|-------
         GPL-2.0                                              11139
      
         and resulted in the first patch in this series.
      
         If that file was a */uapi/* path one, it was "GPL-2.0 WITH
         Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:
      
         SPDX license identifier                            # files
         ---------------------------------------------------|-------
         GPL-2.0 WITH Linux-syscall-note                        930
      
         and resulted in the second patch in this series.
      
       - if a file had some form of licensing information in it, and was one
         of the */uapi/* ones, it was denoted with the Linux-syscall-note if
         any GPL family license was found in the file or had no licensing in
         it (per prior point).  Results summary:
      
         SPDX license identifier                            # files
         ---------------------------------------------------|------
         GPL-2.0 WITH Linux-syscall-note                       270
         GPL-2.0+ WITH Linux-syscall-note                      169
         ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
         ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
         LGPL-2.1+ WITH Linux-syscall-note                      15
         GPL-1.0+ WITH Linux-syscall-note                       14
         ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
         LGPL-2.0+ WITH Linux-syscall-note                       4
         LGPL-2.1 WITH Linux-syscall-note                        3
         ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
         ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1
      
         and that resulted in the third patch in this series.
      
       - when the two scanners agreed on the detected license(s), that became
         the concluded license(s).
      
       - when there was disagreement between the two scanners (one detected a
         license but the other didn't, or they both detected different
         licenses) a manual inspection of the file occurred.
      
       - In most cases a manual inspection of the information in the file
         resulted in a clear resolution of the license that should apply (and
         which scanner probably needed to revisit its heuristics).
      
       - When it was not immediately clear, the license identifier was
         confirmed with lawyers working with the Linux Foundation.
      
       - If there was any question as to the appropriate license identifier,
         the file was flagged for further research and to be revisited later
         in time.
      
      In total, over 70 hours of logged manual review was done on the
      spreadsheet to determine the SPDX license identifiers to apply to the
      source files by Kate, Philippe, Thomas and, in some cases, confirmation
      by lawyers working with the Linux Foundation.
      
      Kate also obtained a third independent scan of the 4.13 code base from
      FOSSology, and compared selected files where the other two scanners
      disagreed against that SPDX file, to see if there was new insights.  The
      Windriver scanner is based on an older version of FOSSology in part, so
      they are related.
      
      Thomas did random spot checks in about 500 files from the spreadsheets
      for the uapi headers and agreed with SPDX license identifier in the
      files he inspected. For the non-uapi files Thomas did random spot checks
      in about 15000 files.
      
      In initial set of patches against 4.14-rc6, 3 files were found to have
      copy/paste license identifier errors, and have been fixed to reflect the
      correct identifier.
      
      Additionally Philippe spent 10 hours this week doing a detailed manual
      inspection and review of the 12,461 patched files from the initial patch
      version early this week with:
       - a full scancode scan run, collecting the matched texts, detected
         license ids and scores
       - reviewing anything where there was a license detected (about 500+
         files) to ensure that the applied SPDX license was correct
       - reviewing anything where there was no detection but the patch license
         was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
         SPDX license was correct
      
      This produced a worksheet with 20 files needing minor correction.  This
      worksheet was then exported into 3 different .csv files for the
      different types of files to be modified.
      
      These .csv files were then reviewed by Greg.  Thomas wrote a script to
      parse the csv files and add the proper SPDX tag to the file, in the
      format that the file expected.  This script was further refined by Greg
      based on the output to detect more types of files automatically and to
      distinguish between header and source .c files (which need different
      comment types.)  Finally Greg ran the script using the .csv files to
      generate the patches.
      Reviewed-by: default avatarKate Stewart <kstewart@linuxfoundation.org>
      Reviewed-by: default avatarPhilippe Ombredanne <pombredanne@nexb.com>
      Reviewed-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      b2441318