1. 13 Dec, 2015 40 commits
    • Egbert Eich's avatar
      drm/ast: Initialized data needed to map fbdev memory · 479b601b
      Egbert Eich authored
      commit 28fb4cb7 upstream.
      
      Due to a missing initialization there was no way to map fbdev memory.
      Thus for example using the Xserver with the fbdev driver failed.
      This fix adds initialization for fix.smem_start and fix.smem_len
      in the fb_info structure, which fixes this problem.
      Requested-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
      Signed-off-by: default avatarEgbert Eich <eich@suse.de>
      [pulled from SuSE tree by me - airlied]
      Signed-off-by: default avatarDave Airlie <airlied@redhat.com>
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      479b601b
    • Jason Liu's avatar
      drivers: of: of_reserved_mem: fixup the alignment with CMA setup · 5b7bf79a
      Jason Liu authored
      commit 1cc8e345 upstream.
      
      There is an alignment mismatch issue between the of_reserved_mem and
      the CMA setup requirement. The of_reserved_mem will try to get the
      alignment value from the DTS and pass it to __memblock_alloc_base to
      do the memory block base allocation, but the alignment value specified
      in the DTS may not satisfy the CAM setup requirement since CMA setup
      required the alignment as the following in the code:
      
      align = PAGE_SIZE << max(MAX_ORDER - 1, pageblock_order);
      
      The sanity check in the function of rmem_cma_setup will fail if the
      alignment does not setup correctly and thus CMA will fail to setup.
      
      This patch is to fixup the alignment to meet the CMA setup required.
      
      Mailing-list-thread: https://lkml.org/lkml/2015/11/9/138Signed-off-by: default avatarJason Liu <r64343@freescale.com>
      Acked-by: default avatarMarek Szyprowski <m.szyprowski@samsung.com>
      Cc: Grant Likely <grant.likely@linaro.org>
      Cc: Rob Herring <robh+dt@kernel.org>
      Signed-off-by: default avatarRob Herring <robh@kernel.org>
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      5b7bf79a
    • Paolo Bonzini's avatar
      KVM: svm: unconditionally intercept #DB · 13961a17
      Paolo Bonzini authored
      commit cbdb967a upstream.
      
      This is needed to avoid the possibility that the guest triggers
      an infinite stream of #DB exceptions (CVE-2015-8104).
      
      VMX is not affected: because it does not save DR6 in the VMCS,
      it already intercepts #DB unconditionally.
      Reported-by: default avatarJan Beulich <jbeulich@suse.com>
      Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      13961a17
    • Eric Northup's avatar
      KVM: x86: work around infinite loop in microcode when #AC is delivered · 033edc3a
      Eric Northup authored
      commit 54a20552 upstream.
      
      It was found that a guest can DoS a host by triggering an infinite
      stream of "alignment check" (#AC) exceptions.  This causes the
      microcode to enter an infinite loop where the core never receives
      another interrupt.  The host kernel panics pretty quickly due to the
      effects (CVE-2015-5307).
      Signed-off-by: default avatarEric Northup <digitaleric@google.com>
      Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      033edc3a
    • Nadav Amit's avatar
      KVM: x86: Defining missing x86 vectors · 428a49dd
      Nadav Amit authored
      commit c9cdd085 upstream.
      
      Defining XE, XM and VE vector numbers.
      Signed-off-by: default avatarNadav Amit <namit@cs.technion.ac.il>
      Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      428a49dd
    • K. Y. Srinivasan's avatar
      storvsc: Don't set the SRB_FLAGS_QUEUE_ACTION_ENABLE flag · 06f7484b
      K. Y. Srinivasan authored
      commit 8cf308e1 upstream.
      
      Don't set the SRB_FLAGS_QUEUE_ACTION_ENABLE flag since we are not specifying
      tags.  Without this, the qlogic driver doesn't work properly with storvsc.
      Signed-off-by: default avatarK. Y. Srinivasan <kys@microsoft.com>
      Signed-off-by: default avatarJames Bottomley <JBottomley@Odin.com>
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      06f7484b
    • Hans de Goede's avatar
      ideapad-laptop: Add Lenovo Yoga 900 to no_hw_rfkill dmi list · 32592e53
      Hans de Goede authored
      commit f71c882d upstream.
      
      Like some of the other Yoga models the Lenovo Yoga 900 does not have a
      hw rfkill switch, and trying to read the hw rfkill switch through the
      ideapad module causes it to always reported blocking breaking wifi.
      
      This commit adds the Lenovo Yoga 900 to the no_hw_rfkill dmi list, fixing
      the wifi breakage.
      
      BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=1275490Reported-and-tested-by: default avatarKevin Fenzi <kevin@scrye.com>
      Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
      Signed-off-by: default avatarDarren Hart <dvhart@linux.intel.com>
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      32592e53
    • Filipe Manana's avatar
      Btrfs: fix race when listing an inode's xattrs · 2a907a29
      Filipe Manana authored
      commit f1cd1f0b upstream.
      
      When listing a inode's xattrs we have a time window where we race against
      a concurrent operation for adding a new hard link for our inode that makes
      us not return any xattr to user space. In order for this to happen, the
      first xattr of our inode needs to be at slot 0 of a leaf and the previous
      leaf must still have room for an inode ref (or extref) item, and this can
      happen because an inode's listxattrs callback does not lock the inode's
      i_mutex (nor does the VFS does it for us), but adding a hard link to an
      inode makes the VFS lock the inode's i_mutex before calling the inode's
      link callback.
      
      If we have the following leafs:
      
                     Leaf X (has N items)                    Leaf Y
      
       [ ... (257 INODE_ITEM 0) (257 INODE_REF 256) ]  [ (257 XATTR_ITEM 12345), ... ]
                 slot N - 2         slot N - 1              slot 0
      
      The race illustrated by the following sequence diagram is possible:
      
             CPU 1                                               CPU 2
      
        btrfs_listxattr()
      
          searches for key (257 XATTR_ITEM 0)
      
          gets path with path->nodes[0] == leaf X
          and path->slots[0] == N
      
          because path->slots[0] is >=
          btrfs_header_nritems(leaf X), it calls
          btrfs_next_leaf()
      
          btrfs_next_leaf()
            releases the path
      
                                                         adds key (257 INODE_REF 666)
                                                         to the end of leaf X (slot N),
                                                         and leaf X now has N + 1 items
      
            searches for the key (257 INODE_REF 256),
            with path->keep_locks == 1, because that
            is the last key it saw in leaf X before
            releasing the path
      
            ends up at leaf X again and it verifies
            that the key (257 INODE_REF 256) is no
            longer the last key in leaf X, so it
            returns with path->nodes[0] == leaf X
            and path->slots[0] == N, pointing to
            the new item with key (257 INODE_REF 666)
      
          btrfs_listxattr's loop iteration sees that
          the type of the key pointed by the path is
          different from the type BTRFS_XATTR_ITEM_KEY
          and so it breaks the loop and stops looking
          for more xattr items
            --> the application doesn't get any xattr
                listed for our inode
      
      So fix this by breaking the loop only if the key's type is greater than
      BTRFS_XATTR_ITEM_KEY and skip the current key if its type is smaller.
      Signed-off-by: default avatarFilipe Manana <fdmanana@suse.com>
      [ luis: backported to 3.16:
        - drop btrfs_key_type(), which was dropped upstream by
          962a298f ("btrfs: kill the key type accessor helpers") ]
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      2a907a29
    • Peter Oberparleiter's avatar
      scsi_sysfs: Fix queue_ramp_up_period return code · 8fc658bb
      Peter Oberparleiter authored
      commit 863e02d0 upstream.
      
      Writing a number to /sys/bus/scsi/devices/<sdev>/queue_ramp_up_period
      returns the value of that number instead of the number of bytes written.
      This behavior can confuse programs expecting POSIX write() semantics.
      Fix this by returning the number of bytes written instead.
      Signed-off-by: default avatarPeter Oberparleiter <oberpar@linux.vnet.ibm.com>
      Reviewed-by: default avatarHannes Reinecke <hare@suse.de>
      Reviewed-by: default avatarMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
      Reviewed-by: default avatarEwan D. Milne <emilne@redhat.com>
      Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      8fc658bb
    • Peter Zijlstra's avatar
      perf: Fix inherited events vs. tracepoint filters · f7fc5a0c
      Peter Zijlstra authored
      commit b71b437e upstream.
      
      Arnaldo reported that tracepoint filters seem to misbehave (ie. not
      apply) on inherited events.
      
      The fix is obvious; filters are only set on the actual (parent)
      event, use the normal pattern of using this parent event for filters.
      This is safe because each child event has a reference to it.
      Reported-by: default avatarArnaldo Carvalho de Melo <acme@kernel.org>
      Tested-by: default avatarArnaldo Carvalho de Melo <acme@kernel.org>
      Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: Adrian Hunter <adrian.hunter@intel.com>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: David Ahern <dsahern@gmail.com>
      Cc: Frédéric Weisbecker <fweisbec@gmail.com>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Wang Nan <wangnan0@huawei.com>
      Link: http://lkml.kernel.org/r/20151102095051.GN17308@twins.programming.kicks-ass.netSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      f7fc5a0c
    • Filipe Manana's avatar
      Btrfs: fix race leading to BUG_ON when running delalloc for nodatacow · 4e7e67fb
      Filipe Manana authored
      commit 1d512cb7 upstream.
      
      If we are using the NO_HOLES feature, we have a tiny time window when
      running delalloc for a nodatacow inode where we can race with a concurrent
      link or xattr add operation leading to a BUG_ON.
      
      This happens because at run_delalloc_nocow() we end up casting a leaf item
      of type BTRFS_INODE_[REF|EXTREF]_KEY or of type BTRFS_XATTR_ITEM_KEY to a
      file extent item (struct btrfs_file_extent_item) and then analyse its
      extent type field, which won't match any of the expected extent types
      (values BTRFS_FILE_EXTENT_[REG|PREALLOC|INLINE]) and therefore trigger an
      explicit BUG_ON(1).
      
      The following sequence diagram shows how the race happens when running a
      no-cow dellaloc range [4K, 8K[ for inode 257 and we have the following
      neighbour leafs:
      
                   Leaf X (has N items)                    Leaf Y
      
       [ ... (257 INODE_ITEM 0) (257 INODE_REF 256) ]  [ (257 EXTENT_DATA 8192), ... ]
                    slot N - 2         slot N - 1              slot 0
      
       (Note the implicit hole for inode 257 regarding the [0, 8K[ range)
      
             CPU 1                                         CPU 2
      
       run_dealloc_nocow()
         btrfs_lookup_file_extent()
           --> searches for a key with value
               (257 EXTENT_DATA 4096) in the
               fs/subvol tree
           --> returns us a path with
               path->nodes[0] == leaf X and
               path->slots[0] == N
      
         because path->slots[0] is >=
         btrfs_header_nritems(leaf X), it
         calls btrfs_next_leaf()
      
         btrfs_next_leaf()
           --> releases the path
      
                                                    hard link added to our inode,
                                                    with key (257 INODE_REF 500)
                                                    added to the end of leaf X,
                                                    so leaf X now has N + 1 keys
      
           --> searches for the key
               (257 INODE_REF 256), because
               it was the last key in leaf X
               before it released the path,
               with path->keep_locks set to 1
      
           --> ends up at leaf X again and
               it verifies that the key
               (257 INODE_REF 256) is no longer
               the last key in the leaf, so it
               returns with path->nodes[0] ==
               leaf X and path->slots[0] == N,
               pointing to the new item with
               key (257 INODE_REF 500)
      
         the loop iteration of run_dealloc_nocow()
         does not break out the loop and continues
         because the key referenced in the path
         at path->nodes[0] and path->slots[0] is
         for inode 257, its type is < BTRFS_EXTENT_DATA_KEY
         and its offset (500) is less then our delalloc
         range's end (8192)
      
         the item pointed by the path, an inode reference item,
         is (incorrectly) interpreted as a file extent item and
         we get an invalid extent type, leading to the BUG_ON(1):
      
         if (extent_type == BTRFS_FILE_EXTENT_REG ||
            extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
             (...)
         } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
             (...)
         } else {
             BUG_ON(1)
         }
      
      The same can happen if a xattr is added concurrently and ends up having
      a key with an offset smaller then the delalloc's range end.
      
      So fix this by skipping keys with a type smaller than
      BTRFS_EXTENT_DATA_KEY.
      Signed-off-by: default avatarFilipe Manana <fdmanana@suse.com>
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      4e7e67fb
    • Filipe Manana's avatar
      Btrfs: fix race leading to incorrect item deletion when dropping extents · 6128a5a6
      Filipe Manana authored
      commit aeafbf84 upstream.
      
      While running a stress test I got the following warning triggered:
      
        [191627.672810] ------------[ cut here ]------------
        [191627.673949] WARNING: CPU: 8 PID: 8447 at fs/btrfs/file.c:779 __btrfs_drop_extents+0x391/0xa50 [btrfs]()
        (...)
        [191627.701485] Call Trace:
        [191627.702037]  [<ffffffff8145f077>] dump_stack+0x4f/0x7b
        [191627.702992]  [<ffffffff81095de5>] ? console_unlock+0x356/0x3a2
        [191627.704091]  [<ffffffff8104b3b0>] warn_slowpath_common+0xa1/0xbb
        [191627.705380]  [<ffffffffa0664499>] ? __btrfs_drop_extents+0x391/0xa50 [btrfs]
        [191627.706637]  [<ffffffff8104b46d>] warn_slowpath_null+0x1a/0x1c
        [191627.707789]  [<ffffffffa0664499>] __btrfs_drop_extents+0x391/0xa50 [btrfs]
        [191627.709155]  [<ffffffff8115663c>] ? cache_alloc_debugcheck_after.isra.32+0x171/0x1d0
        [191627.712444]  [<ffffffff81155007>] ? kmemleak_alloc_recursive.constprop.40+0x16/0x18
        [191627.714162]  [<ffffffffa06570c9>] insert_reserved_file_extent.constprop.40+0x83/0x24e [btrfs]
        [191627.715887]  [<ffffffffa065422b>] ? start_transaction+0x3bb/0x610 [btrfs]
        [191627.717287]  [<ffffffffa065b604>] btrfs_finish_ordered_io+0x273/0x4e2 [btrfs]
        [191627.728865]  [<ffffffffa065b888>] finish_ordered_fn+0x15/0x17 [btrfs]
        [191627.730045]  [<ffffffffa067d688>] normal_work_helper+0x14c/0x32c [btrfs]
        [191627.731256]  [<ffffffffa067d96a>] btrfs_endio_write_helper+0x12/0x14 [btrfs]
        [191627.732661]  [<ffffffff81061119>] process_one_work+0x24c/0x4ae
        [191627.733822]  [<ffffffff810615b0>] worker_thread+0x206/0x2c2
        [191627.734857]  [<ffffffff810613aa>] ? process_scheduled_works+0x2f/0x2f
        [191627.736052]  [<ffffffff810613aa>] ? process_scheduled_works+0x2f/0x2f
        [191627.737349]  [<ffffffff810669a6>] kthread+0xef/0xf7
        [191627.738267]  [<ffffffff810f3b3a>] ? time_hardirqs_on+0x15/0x28
        [191627.739330]  [<ffffffff810668b7>] ? __kthread_parkme+0xad/0xad
        [191627.741976]  [<ffffffff81465592>] ret_from_fork+0x42/0x70
        [191627.743080]  [<ffffffff810668b7>] ? __kthread_parkme+0xad/0xad
        [191627.744206] ---[ end trace bbfddacb7aaada8d ]---
      
        $ cat -n fs/btrfs/file.c
        691  int __btrfs_drop_extents(struct btrfs_trans_handle *trans,
        (...)
        758                  btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
        759                  if (key.objectid > ino ||
        760                      key.type > BTRFS_EXTENT_DATA_KEY || key.offset >= end)
        761                          break;
        762
        763                  fi = btrfs_item_ptr(leaf, path->slots[0],
        764                                      struct btrfs_file_extent_item);
        765                  extent_type = btrfs_file_extent_type(leaf, fi);
        766
        767                  if (extent_type == BTRFS_FILE_EXTENT_REG ||
        768                      extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
        (...)
        774                  } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
        (...)
        778                  } else {
        779                          WARN_ON(1);
        780                          extent_end = search_start;
        781                  }
        (...)
      
      This happened because the item we were processing did not match a file
      extent item (its key type != BTRFS_EXTENT_DATA_KEY), and even on this
      case we cast the item to a struct btrfs_file_extent_item pointer and
      then find a type field value that does not match any of the expected
      values (BTRFS_FILE_EXTENT_[REG|PREALLOC|INLINE]). This scenario happens
      due to a tiny time window where a race can happen as exemplified below.
      For example, consider the following scenario where we're using the
      NO_HOLES feature and we have the following two neighbour leafs:
      
                     Leaf X (has N items)                    Leaf Y
      
      [ ... (257 INODE_ITEM 0) (257 INODE_REF 256) ]  [ (257 EXTENT_DATA 8192), ... ]
                slot N - 2         slot N - 1              slot 0
      
      Our inode 257 has an implicit hole in the range [0, 8K[ (implicit rather
      than explicit because NO_HOLES is enabled). Now if our inode has an
      ordered extent for the range [4K, 8K[ that is finishing, the following
      can happen:
      
                CPU 1                                       CPU 2
      
        btrfs_finish_ordered_io()
          insert_reserved_file_extent()
            __btrfs_drop_extents()
               Searches for the key
                (257 EXTENT_DATA 4096) through
                btrfs_lookup_file_extent()
      
               Key not found and we get a path where
               path->nodes[0] == leaf X and
               path->slots[0] == N
      
               Because path->slots[0] is >=
               btrfs_header_nritems(leaf X), we call
               btrfs_next_leaf()
      
               btrfs_next_leaf() releases the path
      
                                                        inserts key
                                                        (257 INODE_REF 4096)
                                                        at the end of leaf X,
                                                        leaf X now has N + 1 keys,
                                                        and the new key is at
                                                        slot N
      
               btrfs_next_leaf() searches for
               key (257 INODE_REF 256), with
               path->keep_locks set to 1,
               because it was the last key it
               saw in leaf X
      
                 finds it in leaf X again and
                 notices it's no longer the last
                 key of the leaf, so it returns 0
                 with path->nodes[0] == leaf X and
                 path->slots[0] == N (which is now
                 < btrfs_header_nritems(leaf X)),
                 pointing to the new key
                 (257 INODE_REF 4096)
      
               __btrfs_drop_extents() casts the
               item at path->nodes[0], slot
               path->slots[0], to a struct
               btrfs_file_extent_item - it does
               not skip keys for the target
               inode with a type less than
               BTRFS_EXTENT_DATA_KEY
               (BTRFS_INODE_REF_KEY < BTRFS_EXTENT_DATA_KEY)
      
               sees a bogus value for the type
               field triggering the WARN_ON in
               the trace shown above, and sets
               extent_end = search_start (4096)
      
               does the if-then-else logic to
               fixup 0 length extent items created
               by a past bug from hole punching:
      
                 if (extent_end == key.offset &&
                     extent_end >= search_start)
                     goto delete_extent_item;
      
               that evaluates to true and it ends
               up deleting the key pointed to by
               path->slots[0], (257 INODE_REF 4096),
               from leaf X
      
      The same could happen for example for a xattr that ends up having a key
      with an offset value that matches search_start (very unlikely but not
      impossible).
      
      So fix this by ensuring that keys smaller than BTRFS_EXTENT_DATA_KEY are
      skipped, never casted to struct btrfs_file_extent_item and never deleted
      by accident. Also protect against the unexpected case of getting a key
      for a lower inode number by skipping that key and issuing a warning.
      Signed-off-by: default avatarFilipe Manana <fdmanana@suse.com>
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      6128a5a6
    • Borislav Petkov's avatar
      x86/cpu: Call verify_cpu() after having entered long mode too · b80a164b
      Borislav Petkov authored
      commit 04633df0 upstream.
      
      When we get loaded by a 64-bit bootloader, kernel entry point is
      startup_64 in head_64.S. We don't trust any and all bootloaders because
      some will fiddle with CPU configuration so we go ahead and massage each
      CPU into sanity again.
      
      For example, some dell BIOSes have this XD disable feature which set
      IA32_MISC_ENABLE[34] and disable NX. This might be some dumb workaround
      for other OSes but Linux sure doesn't need it.
      
      A similar thing is present in the Surface 3 firmware - see
      https://bugzilla.kernel.org/show_bug.cgi?id=106051 - which sets this bit
      only on the BSP:
      
        # rdmsr -a 0x1a0
        400850089
        850089
        850089
        850089
      
      I know, right?!
      
      There's not even an off switch in there.
      
      So fix all those cases by sanitizing the 64-bit entry point too. For
      that, make verify_cpu() callable in 64-bit mode also.
      Requested-and-debugged-by: default avatar"H. Peter Anvin" <hpa@zytor.com>
      Reported-and-tested-by: default avatarBastien Nocera <bugzilla@hadess.net>
      Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
      Cc: Matt Fleming <matt@codeblueprint.co.uk>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Link: http://lkml.kernel.org/r/1446739076-21303-1-git-send-email-bp@alien8.deSigned-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      b80a164b
    • Krzysztof Mazur's avatar
      x86/setup: Fix low identity map for >= 2GB kernel range · e30dbbf3
      Krzysztof Mazur authored
      commit 68accac3 upstream.
      
      The commit f5f3497c extended the low identity mapping. However, if
      the kernel uses more than 2 GB (VMSPLIT_2G_OPT or VMSPLIT_1G memory
      split), the normal memory mapping is overwritten by the low identity
      mapping causing a crash. To avoid overwritting, limit the low identity
      map to cover only memory before kernel range (PAGE_OFFSET).
      
      Fixes: f5f3497c "x86/setup: Extend low identity map to cover whole kernel range
      Signed-off-by: default avatarKrzysztof Mazur <krzysiek@podlesie.net>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Laszlo Ersek <lersek@redhat.com>
      Cc: Matt Fleming <matt.fleming@intel.com>
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Link: http://lkml.kernel.org/r/1446815916-22105-1-git-send-email-krzysiek@podlesie.netSigned-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      e30dbbf3
    • Paolo Bonzini's avatar
      x86/setup: Extend low identity map to cover whole kernel range · a18887a2
      Paolo Bonzini authored
      commit f5f3497c upstream.
      
      On 32-bit systems, the initial_page_table is reused by
      efi_call_phys_prolog as an identity map to call
      SetVirtualAddressMap.  efi_call_phys_prolog takes care of
      converting the current CPU's GDT to a physical address too.
      
      For PAE kernels the identity mapping is achieved by aliasing the
      first PDPE for the kernel memory mapping into the first PDPE
      of initial_page_table.  This makes the EFI stub's trick "just work".
      
      However, for non-PAE kernels there is no guarantee that the identity
      mapping in the initial_page_table extends as far as the GDT; in this
      case, accesses to the GDT will cause a page fault (which quickly becomes
      a triple fault).  Fix this by copying the kernel mappings from
      swapper_pg_dir to initial_page_table twice, both at PAGE_OFFSET and at
      identity mapping.
      
      For some reason, this is only reproducible with QEMU's dynamic translation
      mode, and not for example with KVM.  However, even under KVM one can clearly
      see that the page table is bogus:
      
          $ qemu-system-i386 -pflash OVMF.fd -M q35 vmlinuz0 -s -S -daemonize
          $ gdb
          (gdb) target remote localhost:1234
          (gdb) hb *0x02858f6f
          Hardware assisted breakpoint 1 at 0x2858f6f
          (gdb) c
          Continuing.
      
          Breakpoint 1, 0x02858f6f in ?? ()
          (gdb) monitor info registers
          ...
          GDT=     0724e000 000000ff
          IDT=     fffbb000 000007ff
          CR0=0005003b CR2=ff896000 CR3=032b7000 CR4=00000690
          ...
      
      The page directory is sane:
      
          (gdb) x/4wx 0x32b7000
          0x32b7000:	0x03398063	0x03399063	0x0339a063	0x0339b063
          (gdb) x/4wx 0x3398000
          0x3398000:	0x00000163	0x00001163	0x00002163	0x00003163
          (gdb) x/4wx 0x3399000
          0x3399000:	0x00400003	0x00401003	0x00402003	0x00403003
      
      but our particular page directory entry is empty:
      
          (gdb) x/1wx 0x32b7000 + (0x724e000 >> 22) * 4
          0x32b7070:	0x00000000
      
      [ It appears that you can skate past this issue if you don't receive
        any interrupts while the bogus GDT pointer is loaded, or if you avoid
        reloading the segment registers in general.
      
        Andy Lutomirski provides some additional insight:
      
         "AFAICT it's entirely permissible for the GDTR and/or LDT
          descriptor to point to unmapped memory.  Any attempt to use them
          (segment loads, interrupts, IRET, etc) will try to access that memory
          as if the access came from CPL 0 and, if the access fails, will
          generate a valid page fault with CR2 pointing into the GDT or
          LDT."
      
        Up until commit 23a0d4e8 ("efi: Disable interrupts around EFI
        calls, not in the epilog/prolog calls") interrupts were disabled
        around the prolog and epilog calls, and the functional GDT was
        re-installed before interrupts were re-enabled.
      
        Which explains why no one has hit this issue until now. ]
      Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      Reported-by: default avatarLaszlo Ersek <lersek@redhat.com>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Signed-off-by: default avatarMatt Fleming <matt.fleming@intel.com>
      [ Updated changelog. ]
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      a18887a2
    • Oleg Nesterov's avatar
      proc: actually make proc_fd_permission() thread-friendly · 720ae734
      Oleg Nesterov authored
      commit 54708d28 upstream.
      
      The commit 96d0df79 ("proc: make proc_fd_permission() thread-friendly")
      fixed the access to /proc/self/fd from sub-threads, but introduced another
      problem: a sub-thread can't access /proc/<tid>/fd/ or /proc/thread-self/fd
      if generic_permission() fails.
      
      Change proc_fd_permission() to check same_thread_group(pid_task(), current).
      
      Fixes: 96d0df79 ("proc: make proc_fd_permission() thread-friendly")
      Reported-by: default avatar"Jin, Yihua" <yihua.jin@intel.com>
      Signed-off-by: default avatarOleg Nesterov <oleg@redhat.com>
      Cc: "Eric W. Biederman" <ebiederm@xmission.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      720ae734
    • Takashi Iwai's avatar
      Input: elantech - add Fujitsu Lifebook U745 to force crc_enabled · edd540a6
      Takashi Iwai authored
      commit 60603950 upstream.
      
      Another Lifebook machine that needs the same quirk as other similar
      models to make the driver working.
      
      Bugzilla: https://bugzilla.opensuse.org/show_bug.cgi?id=883192Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      Signed-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      edd540a6
    • Catalin Marinas's avatar
      mm: slab: only move management objects off-slab for sizes larger than KMALLOC_MIN_SIZE · ca317d04
      Catalin Marinas authored
      commit d4322d88 upstream.
      
      On systems with a KMALLOC_MIN_SIZE of 128 (arm64, some mips and powerpc
      configurations defining ARCH_DMA_MINALIGN to 128), the first
      kmalloc_caches[] entry to be initialised after slab_early_init = 0 is
      "kmalloc-128" with index 7.  Depending on the debug kernel configuration,
      sizeof(struct kmem_cache) can be larger than 128 resulting in an
      INDEX_NODE of 8.
      
      Commit 8fc9cf42 ("slab: make more slab management structure off the
      slab") enables off-slab management objects for sizes starting with
      PAGE_SIZE >> 5 (128 bytes for a 4KB page configuration) and the creation
      of the "kmalloc-128" cache would try to place the management objects
      off-slab.  However, since KMALLOC_MIN_SIZE is already 128 and
      freelist_size == 32 in __kmem_cache_create(), kmalloc_slab(freelist_size)
      returns NULL (kmalloc_caches[7] not populated yet).  This triggers the
      following bug on arm64:
      
        kernel BUG at /work/Linux/linux-2.6-aarch64/mm/slab.c:2283!
        Internal error: Oops - BUG: 0 [#1] SMP
        Modules linked in:
        CPU: 0 PID: 0 Comm: swapper Not tainted 4.3.0-rc4+ #540
        Hardware name: Juno (DT)
        PC is at __kmem_cache_create+0x21c/0x280
        LR is at __kmem_cache_create+0x210/0x280
        [...]
        Call trace:
          __kmem_cache_create+0x21c/0x280
          create_boot_cache+0x48/0x80
          create_kmalloc_cache+0x50/0x88
          create_kmalloc_caches+0x4c/0xf4
          kmem_cache_init+0x100/0x118
          start_kernel+0x214/0x33c
      
      This patch introduces an OFF_SLAB_MIN_SIZE definition to avoid off-slab
      management objects for sizes equal to or smaller than KMALLOC_MIN_SIZE.
      
      Fixes: 8fc9cf42 ("slab: make more slab management structure off the slab")
      Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
      Reported-by: default avatarGeert Uytterhoeven <geert@linux-m68k.org>
      Acked-by: default avatarChristoph Lameter <cl@linux.com>
      Cc: Pekka Enberg <penberg@kernel.org>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      ca317d04
    • Christoph Hellwig's avatar
      scsi: restart list search after unlock in scsi_remove_target · 0c422a84
      Christoph Hellwig authored
      commit 40998193 upstream.
      
      When dropping a lock while iterating a list we must restart the search
      as other threads could have manipulated the list under us.  Without this
      we can get stuck in an endless loop.  This bug was introduced by
      
      commit bc3f02a7
      Author: Dan Williams <djbw@fb.com>
      Date:   Tue Aug 28 22:12:10 2012 -0700
      
          [SCSI] scsi_remove_target: fix softlockup regression on hot remove
      
      Which was itself trying to fix a reported soft lockup issue
      
      http://thread.gmane.org/gmane.linux.kernel/1348679
      
      However, we believe even with this revert of the original patch, the soft
      lockup problem has been fixed by
      
      commit f2495e22
      Author: James Bottomley <JBottomley@Parallels.com>
      Date:   Tue Jan 21 07:01:41 2014 -0800
      
          [SCSI] dual scan thread bug fix
      
      Thanks go to Dan Williams <dan.j.williams@intel.com> for tracking all this
      prior history down.
      Reported-by: default avatarJohannes Thumshirn <jthumshirn@suse.de>
      Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
      Tested-by: default avatarJohannes Thumshirn <jthumshirn@suse.de>
      Reviewed-by: default avatarJohannes Thumshirn <jthumshirn@suse.de>
      Fixes: bc3f02a7Signed-off-by: default avatarJames Bottomley <JBottomley@Odin.com>
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      0c422a84
    • Stefan Richter's avatar
      firewire: ohci: fix JMicron JMB38x IT context discovery · bf60a52f
      Stefan Richter authored
      commit 100ceb66 upstream.
      
      Reported by Clifford and Craig for JMicron OHCI-1394 + SDHCI combo
      controllers:  Often or even most of the time, the controller is
      initialized with the message "added OHCI v1.10 device as card 0, 4 IR +
      0 IT contexts, quirks 0x10".  With 0 isochronous transmit DMA contexts
      (IT contexts), applications like audio output are impossible.
      
      However, OHCI-1394 demands that at least 4 IT contexts are implemented
      by the link layer controller, and indeed JMicron JMB38x do implement
      four of them.  Only their IsoXmitIntMask register is unreliable at early
      access.
      
      With my own JMB381 single function controller I found:
        - I can reproduce the problem with a lower probability than Craig's.
        - If I put a loop around the section which clears and reads
          IsoXmitIntMask, then either the first or the second attempt will
          return the correct initial mask of 0x0000000f.  I never encountered
          a case of needing more than a second attempt.
        - Consequently, if I put a dummy reg_read(...IsoXmitIntMaskSet)
          before the first write, the subsequent read will return the correct
          result.
        - If I merely ignore a wrong read result and force the known real
          result, later isochronous transmit DMA usage works just fine.
      
      So let's just fix this chip bug up by the latter method.  Tested with
      JMB381 on kernel 3.13 and 4.3.
      
      Since OHCI-1394 generally requires 4 IT contexts at a minium, this
      workaround is simply applied whenever the initial read of IsoXmitIntMask
      returns 0, regardless whether it's a JMicron chip or not.  I never heard
      of this issue together with any other chip though.
      
      I am not 100% sure that this fix works on the OHCI-1394 part of JMB380
      and JMB388 combo controllers exactly the same as on the JMB381 single-
      function controller, but so far I haven't had a chance to let an owner
      of a combo chip run a patched kernel.
      
      Strangely enough, IsoRecvIntMask is always reported correctly, even
      though it is probed right before IsoXmitIntMask.
      
      Reported-by: Clifford Dunn
      Reported-by: default avatarCraig Moore <craig.moore@qenos.com>
      Signed-off-by: default avatarStefan Richter <stefanr@s5r6.in-berlin.de>
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      bf60a52f
    • Alexandra Yates's avatar
      ALSA: hda - Add Intel Lewisburg device IDs Audio · 2bec64a0
      Alexandra Yates authored
      commit 5cf92c8b upstream.
      
      Adding Intel codename Lewisburg platform device IDs for audio.
      
      [rearranged the position by tiwai]
      Signed-off-by: default avatarAlexandra Yates <alexandra.yates@linux.intel.com>
      Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      2bec64a0
    • Takashi Iwai's avatar
      ALSA: hda - Apply pin fixup for HP ProBook 6550b · 9927f021
      Takashi Iwai authored
      commit c932b98c upstream.
      
      HP ProBook 6550b needs the same pin fixup applied to other HP B-series
      laptops with docks for making its headphone and dock headphone jacks
      working properly.  We just need to add the codec SSID to the list.
      
      Bugzilla: https://bugzilla.kernel.org/attachment.cgi?id=191971Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      9927f021
    • Krzysztof Kozlowski's avatar
      thermal: exynos: Fix unbalanced regulator disable on probe failure · b6f74a6e
      Krzysztof Kozlowski authored
      commit 824ead03 upstream.
      
      During probe if the regulator could not be enabled, the error exit path
      would still disable it. This could lead to unbalanced counter of
      regulator enable/disable.
      
      The patch moves code for getting and enabling the regulator from
      exynos_map_dt_data() to probe function because it is really not a part
      of getting Device Tree properties.
      Acked-by: default avatarLukasz Majewski <l.majewski@samsung.com>
      Tested-by: default avatarLukasz Majewski <l.majewski@samsung.com>
      Reviewed-by: default avatarAlim Akhtar <alim.akhtar@samsung.com>
      Signed-off-by: default avatarKrzysztof Kozlowski <k.kozlowski@samsung.com>
      Fixes: 5f09a5cb ("thermal: exynos: Disable the regulator on probe failure")
      Signed-off-by: default avatarEduardo Valentin <edubezval@gmail.com>
      [ luis: backported to 3.16: adjusted context ]
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      b6f74a6e
    • Radim Krčmář's avatar
      KVM: VMX: fix SMEP and SMAP without EPT · 2628ad5d
      Radim Krčmář authored
      commit 656ec4a4 upstream.
      
      The comment in code had it mostly right, but we enable paging for
      emulated real mode regardless of EPT.
      
      Without EPT (which implies emulated real mode), secondary VCPUs won't
      start unless we disable SM[AE]P when the guest doesn't use paging.
      Signed-off-by: default avatarRadim Krčmář <rkrcmar@redhat.com>
      Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      2628ad5d
    • libin's avatar
      recordmcount: Fix endianness handling bug for nop_mcount · 811f0bd9
      libin authored
      commit c84da8b9 upstream.
      
      In nop_mcount, shdr->sh_offset and welp->r_offset should handle
      endianness properly, otherwise it will trigger Segmentation fault
      if the recordmcount main and file.o have different endianness.
      
      Link: http://lkml.kernel.org/r/563806C7.7070606@huawei.comSigned-off-by: default avatarLi Bin <huawei.libin@huawei.com>
      Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      811f0bd9
    • Max Filippov's avatar
      xtensa: fix secondary core boot in SMP · fd5507ba
      Max Filippov authored
      commit ab45fb14 upstream.
      
      There are multiple factors adding to the issue in different
      configurations:
      
      - commit 17290231 ("xtensa: add fixup for double exception raised
        in window overflow") added function window_overflow_restore_a0_fixup to
        double exception vector overlapping reset vector location of secondary
        processor cores.
      - on MMUv2 cores RESET_VECTOR1_VADDR may point to uncached kernel memory
        making code overlapping depend on cache type and size, so that without
        cache or with WT cache reset vector code overwrites double exception
        code, making issue even harder to detect.
      - on MMUv3 cores RESET_VECTOR1_VADDR may point to unmapped area, as
        MMUv3 cores change virtual address map to match MMUv2 layout, but
        reset vector virtual address is given for the original MMUv3 mapping.
      - physical memory region of the secondary reset vector is not reserved
        in the physical memory map, and thus may be allocated and overwritten
        at arbitrary moment.
      
      Fix it as follows:
      
      - move window_overflow_restore_a0_fixup code to .text section.
      - define RESET_VECTOR1_VADDR so that it points to reset vector in the
        cacheable MMUv2 map for cores with MMU.
      - reserve reset vector region in the physical memory map. Drop separate
        literal section and build mxhead.S with text section literals.
      Signed-off-by: default avatarMax Filippov <jcmvbkbc@gmail.com>
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      fd5507ba
    • Arik Nemtsov's avatar
      mac80211: allow null chandef in tracing · 50025953
      Arik Nemtsov authored
      commit 254d3dfe upstream.
      
      In TDLS channel-switch operations the chandef can sometimes be NULL.
      Avoid an oops in the trace code for these cases and just print a
      chandef full of zeros.
      
      Fixes: a7a6bdd0 ("mac80211: introduce TDLS channel switch ops")
      Signed-off-by: default avatarArik Nemtsov <arikx.nemtsov@intel.com>
      Signed-off-by: default avatarEmmanuel Grumbach <emmanuel.grumbach@intel.com>
      Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      50025953
    • Janusz.Dziedzic@tieto.com's avatar
      mac80211: fix divide by zero when NOA update · f5e1cc75
      Janusz.Dziedzic@tieto.com authored
      commit 519ee691 upstream.
      
      In case of one shot NOA the interval can be 0, catch that
      instead of potentially (depending on the driver) crashing
      like this:
      
      divide error: 0000 [#1] SMP
      [...]
      Call Trace:
      <IRQ>
      [<ffffffffc08e891c>] ieee80211_extend_absent_time+0x6c/0xb0 [mac80211]
      [<ffffffffc08e8a17>] ieee80211_update_p2p_noa+0xb7/0xe0 [mac80211]
      [<ffffffffc069cc30>] ath9k_p2p_ps_timer+0x170/0x190 [ath9k]
      [<ffffffffc070adf8>] ath_gen_timer_isr+0xc8/0xf0 [ath9k_hw]
      [<ffffffffc0691156>] ath9k_tasklet+0x296/0x2f0 [ath9k]
      [<ffffffff8107ad65>] tasklet_action+0xe5/0xf0
      [...]
      Signed-off-by: default avatarJanusz Dziedzic <janusz.dziedzic@tieto.com>
      Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      f5e1cc75
    • sumit.saxena@avagotech.com's avatar
      megaraid_sas : SMAP restriction--do not access user memory from IOCTL code · bdd07ab7
      sumit.saxena@avagotech.com authored
      commit 323c4a02 upstream.
      
      This is an issue on SMAP enabled CPUs and 32 bit apps running on 64 bit
      OS. Do not access user memory from kernel code. The SMAP bit restricts
      accessing user memory from kernel code.
      Signed-off-by: default avatarSumit Saxena <sumit.saxena@avagotech.com>
      Signed-off-by: default avatarKashyap Desai <kashyap.desai@avagotech.com>
      Reviewed-by: default avatarTomas Henzl <thenzl@redhat.com>
      Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      bdd07ab7
    • Max Filippov's avatar
      xtensa: fixes for configs without loop option · 84e3da3b
      Max Filippov authored
      commit 5029615e upstream.
      
      Build-time fixes:
      - make lbeg/lend/lcount save/restore conditional on kernel entry;
      - don't clear lcount in platform_restart functions unconditionally.
      
      Run-time fixes:
      - use correct end of range register in __endla paired with __loopt, not
        the unused temporary register. This fixes .bss zero-initialization.
        Update comments in asmmacro.h;
      - don't clobber a10 in the usercopy that leads to access to unmapped
        memory.
      Signed-off-by: default avatarMax Filippov <jcmvbkbc@gmail.com>
      [ luis: backported to 3.16: adjusted context ]
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      84e3da3b
    • Herbert Xu's avatar
      crypto: algif_hash - Only export and import on sockets with data · 214fcf79
      Herbert Xu authored
      commit 4afa5f96 upstream.
      
      The hash_accept call fails to work on sockets that have not received
      any data.  For some algorithm implementations it may cause crashes.
      
      This patch fixes this by ensuring that we only export and import on
      sockets that have received data.
      Reported-by: default avatarHarsh Jain <harshjain.prof@gmail.com>
      Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
      Tested-by: default avatarStephan Mueller <smueller@chronox.de>
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      214fcf79
    • Jani Nikula's avatar
    • Mauricio Faria de Oliveira's avatar
      Revert "dm mpath: fix stalls when handling invalid ioctls" · f5699565
      Mauricio Faria de Oliveira authored
      commit 47796938 upstream.
      
      This reverts commit a1989b33.
      
      That commit introduced a regression at least for the case of the SG_IO ioctl()
      running without CAP_SYS_RAWIO capability (e.g., unprivileged users) when there
      are no active paths: the ioctl() fails with the ENOTTY errno immediately rather
      than blocking due to queue_if_no_path until a path becomes active, for example.
      
      That case happens to be exercised by QEMU KVM guests with 'scsi-block' devices
      (qemu "-device scsi-block" [1], libvirt "<disk type='block' device='lun'>" [2])
      from multipath devices; which leads to SCSI/filesystem errors in such a guest.
      
      More general scenarios can hit that regression too. The following demonstration
      employs a SG_IO ioctl() with a standard SCSI INQUIRY command for this objective
      (some output & user changes omitted for brevity and comments added for clarity).
      
      Reverting that commit restores normal operation (queueing) in failing scenarios;
      tested on linux-next (next-20151022).
      
      1) Test-case is based on sg_simple0 [3] (just SG_IO; remove SG_GET_VERSION_NUM)
      
          $ cat sg_simple0.c
          ... see [3] ...
          $ sed '/SG_GET_VERSION_NUM/,/}/d' sg_simple0.c > sgio_inquiry.c
          $ gcc sgio_inquiry.c -o sgio_inquiry
      
      2) The ioctl() works fine with active paths present.
      
          # multipath -l 85ag56
          85ag56 (...) dm-19 IBM     ,2145
          size=60G features='1 queue_if_no_path' hwhandler='0' wp=rw
          |-+- policy='service-time 0' prio=0 status=active
          | |- 8:0:11:0  sdz  65:144  active undef running
          | `- 9:0:9:0   sdbf 67:144  active undef running
          `-+- policy='service-time 0' prio=0 status=enabled
            |- 8:0:12:0  sdae 65:224  active undef running
            `- 9:0:12:0  sdbo 68:32   active undef running
      
          $ ./sgio_inquiry /dev/mapper/85ag56
          Some of the INQUIRY command's response:
              IBM       2145              0000
          INQUIRY duration=0 millisecs, resid=0
      
      3) The ioctl() fails with ENOTTY errno with _no_ active paths present,
         for unprivileged users (rather than blocking due to queue_if_no_path).
      
          # for path in $(multipath -l 85ag56 | grep -o 'sd[a-z]\+'); \
                do multipathd -k"fail path $path"; done
      
          # multipath -l 85ag56
          85ag56 (...) dm-19 IBM     ,2145
          size=60G features='1 queue_if_no_path' hwhandler='0' wp=rw
          |-+- policy='service-time 0' prio=0 status=enabled
          | |- 8:0:11:0  sdz  65:144  failed undef running
          | `- 9:0:9:0   sdbf 67:144  failed undef running
          `-+- policy='service-time 0' prio=0 status=enabled
            |- 8:0:12:0  sdae 65:224  failed undef running
            `- 9:0:12:0  sdbo 68:32   failed undef running
      
          $ ./sgio_inquiry /dev/mapper/85ag56
          sg_simple0: Inquiry SG_IO ioctl error: Inappropriate ioctl for device
      
      4) dmesg shows that scsi_verify_blk_ioctl() failed for SG_IO (0x2285);
         it returns -ENOIOCTLCMD, later replaced with -ENOTTY in vfs_ioctl().
      
          $ dmesg
          <...>
          [] device-mapper: multipath: Failing path 65:144.
          [] device-mapper: multipath: Failing path 67:144.
          [] device-mapper: multipath: Failing path 65:224.
          [] device-mapper: multipath: Failing path 68:32.
          [] sgio_inquiry: sending ioctl 2285 to a partition!
      
      5) The ioctl() only works if the SYS_CAP_RAWIO capability is present
         (then queueing happens -- in this example, queue_if_no_path is set);
         this is due to a conditional check in scsi_verify_blk_ioctl().
      
          # capsh --drop=cap_sys_rawio -- -c './sgio_inquiry /dev/mapper/85ag56'
          sg_simple0: Inquiry SG_IO ioctl error: Inappropriate ioctl for device
      
          # ./sgio_inquiry /dev/mapper/85ag56 &
          [1] 72830
      
          # cat /proc/72830/stack
          [<c00000171c0df700>] 0xc00000171c0df700
          [<c000000000015934>] __switch_to+0x204/0x350
          [<c000000000152d4c>] msleep+0x5c/0x80
          [<c00000000077dfb0>] dm_blk_ioctl+0x70/0x170
          [<c000000000487c40>] blkdev_ioctl+0x2b0/0x9b0
          [<c0000000003128e4>] block_ioctl+0x64/0xd0
          [<c0000000002dd3b0>] do_vfs_ioctl+0x490/0x780
          [<c0000000002dd774>] SyS_ioctl+0xd4/0xf0
          [<c000000000009358>] system_call+0x38/0xd0
      
      6) This is the function call chain exercised in this analysis:
      
      SYSCALL_DEFINE3(ioctl, <...>) @ fs/ioctl.c
          -> do_vfs_ioctl()
              -> vfs_ioctl()
                  ...
                  error = filp->f_op->unlocked_ioctl(filp, cmd, arg);
                  ...
                      -> dm_blk_ioctl() @ drivers/md/dm.c
                          -> multipath_ioctl() @ drivers/md/dm-mpath.c
                              ...
                              (bdev = NULL, due to no active paths)
                              ...
                              if (!bdev || <...>) {
                                  int err = scsi_verify_blk_ioctl(NULL, cmd);
                                  if (err)
                                      r = err;
                              }
                              ...
                                  -> scsi_verify_blk_ioctl() @ block/scsi_ioctl.c
                                      ...
                                      if (bd && bd == bd->bd_contains) // not taken (bd = NULL)
                                          return 0;
                                      ...
                                      if (capable(CAP_SYS_RAWIO)) // not taken (unprivileged user)
                                          return 0;
                                      ...
                                      printk_ratelimited(KERN_WARNING
                                                 "%s: sending ioctl %x to a partition!\n" <...>);
      
                                      return -ENOIOCTLCMD;
                                  <-
                              ...
                              return r ? : <...>
                          <-
                  ...
                  if (error == -ENOIOCTLCMD)
                      error = -ENOTTY;
                   out:
                      return error;
                  ...
      
      Links:
      [1] http://git.qemu.org/?p=qemu.git;a=commit;h=336a6915bc7089fb20fea4ba99972ad9a97c5f52
      [2] https://libvirt.org/formatdomain.html#elementsDisks (see 'disk' -> 'device')
      [3] http://tldp.org/HOWTO/SCSI-Generic-HOWTO/pexample.html (Revision 1.2, 2002-05-03)
      Signed-off-by: default avatarMauricio Faria de Oliveira <mauricfo@linux.vnet.ibm.com>
      Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      f5699565
    • Brian Norris's avatar
      mtd: blkdevs: fix potential deadlock + lockdep warnings · 9ea06026
      Brian Norris authored
      commit f3c63795 upstream.
      
      Commit 073db4a5 ("mtd: fix: avoid race condition when accessing
      mtd->usecount") fixed a race condition but due to poor ordering of the
      mutex acquisition, introduced a potential deadlock.
      
      The deadlock can occur, for example, when rmmod'ing the m25p80 module, which
      will delete one or more MTDs, along with any corresponding mtdblock
      devices. This could potentially race with an acquisition of the block
      device as follows.
      
       -> blktrans_open()
          ->  mutex_lock(&dev->lock);
          ->  mutex_lock(&mtd_table_mutex);
      
       -> del_mtd_device()
          ->  mutex_lock(&mtd_table_mutex);
          ->  blktrans_notify_remove() -> del_mtd_blktrans_dev()
             ->  mutex_lock(&dev->lock);
      
      This is a classic (potential) ABBA deadlock, which can be fixed by
      making the A->B ordering consistent everywhere. There was no real
      purpose to the ordering in the original patch, AFAIR, so this shouldn't
      be a problem. This ordering was actually already present in
      del_mtd_blktrans_dev(), for one, where the function tried to ensure that
      its caller already held mtd_table_mutex before it acquired &dev->lock:
      
              if (mutex_trylock(&mtd_table_mutex)) {
                      mutex_unlock(&mtd_table_mutex);
                      BUG();
              }
      
      So, reverse the ordering of acquisition of &dev->lock and &mtd_table_mutex so
      we always acquire mtd_table_mutex first.
      
      Snippets of the lockdep output follow:
      
        # modprobe -r m25p80
        [   53.419251]
        [   53.420838] ======================================================
        [   53.427300] [ INFO: possible circular locking dependency detected ]
        [   53.433865] 4.3.0-rc6 #96 Not tainted
        [   53.437686] -------------------------------------------------------
        [   53.444220] modprobe/372 is trying to acquire lock:
        [   53.449320]  (&new->lock){+.+...}, at: [<c043fe4c>] del_mtd_blktrans_dev+0x80/0xdc
        [   53.457271]
        [   53.457271] but task is already holding lock:
        [   53.463372]  (mtd_table_mutex){+.+.+.}, at: [<c0439994>] del_mtd_device+0x18/0x100
        [   53.471321]
        [   53.471321] which lock already depends on the new lock.
        [   53.471321]
        [   53.479856]
        [   53.479856] the existing dependency chain (in reverse order) is:
        [   53.487660]
        -> #1 (mtd_table_mutex){+.+.+.}:
        [   53.492331]        [<c043fc5c>] blktrans_open+0x34/0x1a4
        [   53.497879]        [<c01afce0>] __blkdev_get+0xc4/0x3b0
        [   53.503364]        [<c01b0bb8>] blkdev_get+0x108/0x320
        [   53.508743]        [<c01713c0>] do_dentry_open+0x218/0x314
        [   53.514496]        [<c0180454>] path_openat+0x4c0/0xf9c
        [   53.519959]        [<c0182044>] do_filp_open+0x5c/0xc0
        [   53.525336]        [<c0172758>] do_sys_open+0xfc/0x1cc
        [   53.530716]        [<c000f740>] ret_fast_syscall+0x0/0x1c
        [   53.536375]
        -> #0 (&new->lock){+.+...}:
        [   53.540587]        [<c063f124>] mutex_lock_nested+0x38/0x3cc
        [   53.546504]        [<c043fe4c>] del_mtd_blktrans_dev+0x80/0xdc
        [   53.552606]        [<c043f164>] blktrans_notify_remove+0x7c/0x84
        [   53.558891]        [<c04399f0>] del_mtd_device+0x74/0x100
        [   53.564544]        [<c043c670>] del_mtd_partitions+0x80/0xc8
        [   53.570451]        [<c0439aa0>] mtd_device_unregister+0x24/0x48
        [   53.576637]        [<c046ce6c>] spi_drv_remove+0x1c/0x34
        [   53.582207]        [<c03de0f0>] __device_release_driver+0x88/0x114
        [   53.588663]        [<c03de19c>] device_release_driver+0x20/0x2c
        [   53.594843]        [<c03dd9e8>] bus_remove_device+0xd8/0x108
        [   53.600748]        [<c03dacc0>] device_del+0x10c/0x210
        [   53.606127]        [<c03dadd0>] device_unregister+0xc/0x20
        [   53.611849]        [<c046d878>] __unregister+0x10/0x20
        [   53.617211]        [<c03da868>] device_for_each_child+0x50/0x7c
        [   53.623387]        [<c046eae8>] spi_unregister_master+0x58/0x8c
        [   53.629578]        [<c03e12f0>] release_nodes+0x15c/0x1c8
        [   53.635223]        [<c03de0f8>] __device_release_driver+0x90/0x114
        [   53.641689]        [<c03de900>] driver_detach+0xb4/0xb8
        [   53.647147]        [<c03ddc78>] bus_remove_driver+0x4c/0xa0
        [   53.652970]        [<c00cab50>] SyS_delete_module+0x11c/0x1e4
        [   53.658976]        [<c000f740>] ret_fast_syscall+0x0/0x1c
        [   53.664621]
        [   53.664621] other info that might help us debug this:
        [   53.664621]
        [   53.672979]  Possible unsafe locking scenario:
        [   53.672979]
        [   53.679169]        CPU0                    CPU1
        [   53.683900]        ----                    ----
        [   53.688633]   lock(mtd_table_mutex);
        [   53.692383]                                lock(&new->lock);
        [   53.698306]                                lock(mtd_table_mutex);
        [   53.704658]   lock(&new->lock);
        [   53.707946]
        [   53.707946]  *** DEADLOCK ***
      
      Fixes: 073db4a5 ("mtd: fix: avoid race condition when accessing mtd->usecount")
      Reported-by: default avatarFelipe Balbi <balbi@ti.com>
      Tested-by: default avatarFelipe Balbi <balbi@ti.com>
      Signed-off-by: default avatarBrian Norris <computersforpeace@gmail.com>
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      9ea06026
    • Marek Vasut's avatar
      can: Use correct type in sizeof() in nla_put() · a4d95541
      Marek Vasut authored
      commit 562b103a upstream.
      
      The sizeof() is invoked on an incorrect variable, likely due to some
      copy-paste error, and this might result in memory corruption. Fix this.
      Signed-off-by: default avatarMarek Vasut <marex@denx.de>
      Cc: Wolfgang Grandegger <wg@grandegger.com>
      Cc: netdev@vger.kernel.org
      Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      a4d95541
    • Robin Murphy's avatar
      arm64: Fix compat register mappings · 25a0fff8
      Robin Murphy authored
      commit 5accd17d upstream.
      
      For reasons not entirely apparent, but now enshrined in history, the
      architectural mapping of AArch32 banked registers to AArch64 registers
      actually orders SP_<mode> and LR_<mode> backwards compared to the
      intuitive r13/r14 order, for all modes except FIQ.
      
      Fix the compat_<reg>_<mode> macros accordingly, in the hope of avoiding
      subtle bugs with KVM and AArch32 guests.
      Signed-off-by: default avatarRobin Murphy <robin.murphy@arm.com>
      Acked-by: default avatarWill Deacon <will.deacon@arm.com>
      Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      25a0fff8
    • David Hildenbrand's avatar
      KVM: s390: SCA must not cross page boundaries · 7c724edb
      David Hildenbrand authored
      commit c5c2c393 upstream.
      
      We seemed to have missed a few corner cases in commit f6c137ff
      ("KVM: s390: randomize sca address").
      
      The SCA has a maximum size of 2112 bytes. By setting the sca_offset to
      some unlucky numbers, we exceed the page.
      
      0x7c0 (1984) -> Fits exactly
      0x7d0 (2000) -> 16 bytes out
      0x7e0 (2016) -> 32 bytes out
      0x7f0 (2032) -> 48 bytes out
      
      One VCPU entry is 32 bytes long.
      
      For the last two cases, we actually write data to the other page.
      1. The address of the VCPU.
      2. Injection/delivery/clearing of SIGP externall calls via SIGP IF.
      
      Especially the 2. happens regularly. So this could produce two problems:
      1. The guest losing/getting external calls.
      2. Random memory overwrites in the host.
      
      So this problem happens on every 127 + 128 created VM with 64 VCPUs.
      Acked-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
      Signed-off-by: default avatarDavid Hildenbrand <dahi@linux.vnet.ibm.com>
      Signed-off-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      7c724edb
    • sumit.saxena@avagotech.com's avatar
      megaraid_sas: Do not use PAGE_SIZE for max_sectors · dea853b1
      sumit.saxena@avagotech.com authored
      commit 357ae967 upstream.
      
      Do not use PAGE_SIZE marco to calculate max_sectors per I/O
      request. Driver code assumes PAGE_SIZE will be always 4096 which can
      lead to wrongly calculated value if PAGE_SIZE is not 4096. This issue
      was reported in Ubuntu Bugzilla Bug #1475166.
      Signed-off-by: default avatarSumit Saxena <sumit.saxena@avagotech.com>
      Signed-off-by: default avatarKashyap Desai <kashyap.desai@avagotech.com>
      Reviewed-by: default avatarTomas Henzl <thenzl@redhat.com>
      Reviewed-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
      Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      dea853b1
    • Vineet Gupta's avatar
      MAINTAINERS: Add public mailing list for ARC · fae7751f
      Vineet Gupta authored
      commit 9acdc911 upstream.
      Signed-off-by: default avatarVineet Gupta <vgupta@synopsys.com>
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      fae7751f
    • Kailang Yang's avatar
      ALSA: hda/realtek - Dell XPS one ALC3260 speaker no sound after resume back · c1fc5009
      Kailang Yang authored
      commit 6ed1131f upstream.
      
      This machine had I2S codec for speaker output.
      It need to refill the I2S codec initial verb after resume back.
      Signed-off-by: default avatarKailang Yang <kailang@realtek.com>
      Reported-and-tested-by: default avatarGeorge Gugulea <gugulea@gmail.com>
      Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      [ luis: backported to 3.16: adjusted context ]
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      c1fc5009