review.tizen.org Git - platform/kernel/linux-exynos.git/log

Btrfs: fix scheduler warning when syncing log

We try to lock a mutex while the current task state is not TASK_RUNNING,
which results in the following warning when CONFIG_DEBUG_LOCK_ALLOC=y:

[30736.772501] ------------[ cut here ]------------
[30736.774545] WARNING: CPU: 9 PID: 19972 at kernel/sched/core.c:7300 __might_sleep+0x8b/0xa8()
[30736.783453] do not call blocking ops when !TASK_RUNNING; state=2 set at [<ffffffff8107499b>] prepare_to_wait+0x43/0x89
[30736.786261] Modules linked in: dm_flakey dm_mod crc32c_generic btrfs xor raid6_pq nfsd auth_rpcgss oid_registry nfs_acl nfs lockd grace fscache sunrpc loop parport_pc psmouse parport pcspkr microcode serio_raw evdev processor thermal_sys i2c_piix4 i2c_core button ext4 crc16 jbd2 mbcache sg sr_mod cdrom sd_mod ata_generic virtio_scsi floppy ata_piix libata virtio_pci virtio_ring e1000 virtio scsi_mod
[30736.794323] CPU: 9 PID: 19972 Comm: fsstress Not tainted 3.19.0-rc7-btrfs-next-5+ #1
[30736.795821] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5-0-ge51488c-20140602_164612-nilsson.home.kraxel.org 04/01/2014
[30736.798788]  0000000000000009 ffff88042743fbd8 ffffffff814248ed ffff88043d32f2d8
[30736.800504]  ffff88042743fc28 ffff88042743fc18 ffffffff81045338 0000000000000001
[30736.802131]  ffffffff81064514 ffffffff817c52d1 000000000000026d 0000000000000000
[30736.803676] Call Trace:
[30736.804256]  [<ffffffff814248ed>] dump_stack+0x4c/0x65
[30736.805245]  [<ffffffff81045338>] warn_slowpath_common+0xa1/0xbb
[30736.806360]  [<ffffffff81064514>] ? __might_sleep+0x8b/0xa8
[30736.807391]  [<ffffffff81045398>] warn_slowpath_fmt+0x46/0x48
[30736.808511]  [<ffffffff8107499b>] ? prepare_to_wait+0x43/0x89
[30736.809620]  [<ffffffff8107499b>] ? prepare_to_wait+0x43/0x89
[30736.810691]  [<ffffffff81064514>] __might_sleep+0x8b/0xa8
[30736.811703]  [<ffffffff81426eaf>] mutex_lock_nested+0x2f/0x3a0
[30736.812889]  [<ffffffff8107bfa1>] ? trace_hardirqs_on_caller+0x18f/0x1ab
[30736.814138]  [<ffffffff8107bfca>] ? trace_hardirqs_on+0xd/0xf
[30736.819878]  [<ffffffffa038cfff>] wait_for_writer.isra.12+0x91/0xaa [btrfs]
[30736.821260]  [<ffffffff810748bd>] ? signal_pending_state+0x31/0x31
[30736.822410]  [<ffffffffa0391f0a>] btrfs_sync_log+0x160/0x947 [btrfs]
[30736.823574]  [<ffffffff8107bfa1>] ? trace_hardirqs_on_caller+0x18f/0x1ab
[30736.824847]  [<ffffffff8107bfca>] ? trace_hardirqs_on+0xd/0xf
[30736.825972]  [<ffffffffa036e555>] btrfs_sync_file+0x2b0/0x319 [btrfs]
[30736.827684]  [<ffffffff8117901a>] vfs_fsync_range+0x21/0x23
[30736.828932]  [<ffffffff81179038>] vfs_fsync+0x1c/0x1e
[30736.829917]  [<ffffffff8117928b>] do_fsync+0x34/0x4e
[30736.830862]  [<ffffffff811794b3>] SyS_fsync+0x10/0x14
[30736.831819]  [<ffffffff8142a512>] system_call_fastpath+0x12/0x17
[30736.832982] ---[ end trace c0b57df60d32ae5c ]---

Fix this my acquiring the mutex after calling finish_wait(), which sets the
task's state to TASK_RUNNING.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>

Btrfs: Remove unnecessary placeholder in btrfs_err_code

"notused" is not necessary. Set 1 to the first entry is enough.

Signed-off-by: Takeuchi Satoru <takeuchi_satoru@jp.fujitsu.com
Cc: Gui Hecheng <guihc.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>

btrfs: cleanup init for list in free-space-cache

o removed an unecessary INIT_LIST_HEAD after LIST_HEAD

o merge a declare & INIT_LIST_HEAD pair into one LIST_HEAD

Signed-off-by: Gui Hecheng <guihc.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>

btrfs: delete chunk allocation attemp when setting block group ro

Below test will fail currently:
      mkfs.ext4 -F /dev/sda
      btrfs-convert /dev/sda
      mount /dev/sda /mnt
      btrfs device add -f /dev/sdb /mnt
      btrfs balance start -v -dconvert=raid1 -mconvert=raid1 /mnt

The reason is there are some block groups with usage 0, but the whole
disk hasn't free space to allocate new chunk, so we even can't set such
block group readonly. This patch deletes the chunk allocation when
setting block group ro. For META, we already have reserve. But for
SYSTEM, we don't have, so the check_system_chunk is still required.

Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>

btrfs: clear bio reference after submit_one_bio()

After submit_one_bio(), `bio' can go away. However submit_extent_page()
leave `bio' referable if submit_one_bio() failed (e.g. -ENOMEM on OOM).
It will cause invalid paging request when submit_extent_page() is called
next time.

I reproduced ENOMEM case with the following script (need
CONFIG_FAIL_PAGE_ALLOC, and CONFIG_FAULT_INJECTION_DEBUG_FS).

  #!/bin/bash

  dmesgout=dmesg.txt
  start=100000
  end=300000
  step=1000

  # btrfs options
  device=/dev/vdb1
  directory=/mnt/btrfs

  # fault-injection options
  percent=100
  times=3

  mkdir -p $directory || exit 1
  mount -o compress $device $directory || exit 1

  rm -f $directory/file || exit 1
  dd if=/dev/zero of=$directory/file bs=1M count=512 || exit 1

  for interval in `seq $start $step $end`; do
          dmesg -C
          echo 1 > /proc/sys/vm/drop_caches
          sync
          export FAILCMD_TYPE=fail_page_alloc
          ./failcmd.sh -p $percent -t $times -i $interval \
                  --ignore-gfp-highmem=N --ignore-gfp-wait=N --min-order=0 \
                  -- \
                  cat $directory/file > /dev/null
          dmesg > ${dmesgout}
          if grep -q BUG: ${dmesgout}; then
                  cat ${dmesgout}
                  exit 1
          fi
  done

  umount $directory
  exit 0

Signed-off-by: Naohiro Aota <naota@elisp.net>
Tested-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>

Btrfs: fix scrub race leading to use-after-free

While running a scrub on a kernel with CONFIG_DEBUG_PAGEALLOC=y, I got
the following trace:

[68127.807663] BUG: unable to handle kernel paging request at ffff8803f8947a50
[68127.807663] IP: [<ffffffff8107da31>] do_raw_spin_lock+0x94/0x122
[68127.807663] PGD 3003067 PUD 43e1f5067 PMD 43e030067 PTE 80000003f8947060
[68127.807663] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC
[68127.807663] Modules linked in: dm_flakey dm_mod crc32c_generic btrfs xor raid6_pq nfsd auth_rpcgss oid_registry nfs_acl nfs lockd grace fscache sunrpc loop parport_pc processor parpo
[68127.807663] CPU: 2 PID: 3081 Comm: kworker/u8:5 Not tainted 3.18.0-rc6-btrfs-next-3+ #4
[68127.807663] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5-0-ge51488c-20140602_164612-nilsson.home.kraxel.org 04/01/2014
[68127.807663] Workqueue: btrfs-btrfs-scrub btrfs_scrub_helper [btrfs]
[68127.807663] task: ffff880101fc5250 ti: ffff8803f097c000 task.ti: ffff8803f097c000
[68127.807663] RIP: 0010:[<ffffffff8107da31>]  [<ffffffff8107da31>] do_raw_spin_lock+0x94/0x122
[68127.807663] RSP: 0018:ffff8803f097fbb8  EFLAGS: 00010093
[68127.807663] RAX: 0000000028dd386c RBX: ffff8803f8947a50 RCX: 0000000028dd3854
[68127.807663] RDX: 0000000000000018 RSI: 0000000000000002 RDI: 0000000000000001
[68127.807663] RBP: ffff8803f097fbd8 R08: 0000000000000004 R09: 0000000000000001
[68127.807663] R10: ffff880102620980 R11: ffff8801f3e8c900 R12: 000000000001d390
[68127.807663] R13: 00000000cabd13c8 R14: ffff8803f8947800 R15: ffff88037c574f00
[68127.807663] FS:  0000000000000000(0000) GS:ffff88043dd00000(0000) knlGS:0000000000000000
[68127.807663] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[68127.807663] CR2: ffff8803f8947a50 CR3: 00000000b6481000 CR4: 00000000000006e0
[68127.807663] Stack:
[68127.807663]  ffffffff823942a8 ffff8803f8947a50 ffff8802a3416f80 0000000000000000
[68127.807663]  ffff8803f097fc18 ffffffff8141e7c0 ffffffff81072948 000000000034f314
[68127.807663]  ffff8803f097fc08 0000000000000292 ffff8803f097fc48 ffff8803f8947a50
[68127.807663] Call Trace:
[68127.807663]  [<ffffffff8141e7c0>] _raw_spin_lock_irqsave+0x4b/0x55
[68127.807663]  [<ffffffff81072948>] ? __wake_up+0x22/0x4b
[68127.807663]  [<ffffffff81072948>] __wake_up+0x22/0x4b
[68127.807663]  [<ffffffffa0392327>] scrub_pending_bio_dec+0x32/0x36 [btrfs]
[68127.807663]  [<ffffffffa0395e70>] scrub_bio_end_io_worker+0x5a3/0x5c9 [btrfs]
[68127.807663]  [<ffffffff810e0c7c>] ? time_hardirqs_off+0x15/0x28
[68127.807663]  [<ffffffff81078106>] ? trace_hardirqs_off_caller+0x4c/0xb9
[68127.807663]  [<ffffffffa0372a7c>] normal_work_helper+0xf1/0x238 [btrfs]
[68127.807663]  [<ffffffffa0372d3d>] btrfs_scrub_helper+0x12/0x14 [btrfs]
[68127.807663]  [<ffffffff810582d2>] process_one_work+0x1e4/0x3b6
[68127.807663]  [<ffffffff81078180>] ? trace_hardirqs_off+0xd/0xf
[68127.807663]  [<ffffffff81058dc9>] worker_thread+0x1fb/0x2a8
[68127.807663]  [<ffffffff81058bce>] ? rescuer_thread+0x219/0x219
[68127.807663]  [<ffffffff8105cd75>] kthread+0xdb/0xe3
[68127.807663]  [<ffffffff8105cc9a>] ? __kthread_parkme+0x67/0x67
[68127.807663]  [<ffffffff8141f1ec>] ret_from_fork+0x7c/0xb0
[68127.807663]  [<ffffffff8105cc9a>] ? __kthread_parkme+0x67/0x67
[68127.807663] Code: 39 c2 75 14 8d 8a 00 00 01 00 89 d0 f0 0f b1 0b 39 d0 0f 84 81 00 00 00 4c 69 2d 27 86 99 00 fa 00 00 00 45 31 e4 4d 39 ec 74 2b <8b> 13 89 d0 c1 e8 10 66 39 c2 75
[68127.807663] RIP  [<ffffffff8107da31>] do_raw_spin_lock+0x94/0x122
[68127.807663]  RSP <ffff8803f097fbb8>
[68127.807663] CR2: ffff8803f8947a50
[68127.807663] ---[ end trace d7045aac00a66cd8 ]---

This is due to a race that can happen in a very tiny time window and is
illustrated by the following sequence diagram:

         CPU 1                                                     CPU 2

                                                                btrfs_scrub_dev()
scrub_bio_end_io_worker()
   scrub_pending_bio_dec()
       atomic_dec(&sctx->bios_in_flight)
                                                                   wait sctx->bios_in_flight == 0
                                                                   wait sctx->workers_pending == 0
                                                                   mutex_lock(&fs_info->scrub_lock)
                                                                   (...)
                                                                   mutex_lock(&fs_info->scrub_lock)
                                                                   scrub_free_ctx(sctx)
                                                                      kfree(sctx)
       wake_up(&sctx->list_wait)
          __wake_up()
              spin_lock_irqsave(&sctx->list_wait->lock, flags)

Another variation of this scenario that results in the same use-after-free
issue is:

         CPU 1                                                     CPU 2

                                                                btrfs_scrub_dev()
                                                                   wait sctx->bios_in_flight == 0
scrub_bio_end_io_worker()
   scrub_pending_bio_dec()
       __wake_up(&sctx->list_wait)
          spin_lock_irqsave(&sctx->list_wait->lock, flags)
          default_wake_function()
              wake up task at CPU 2
                                                                   wait sctx->workers_pending == 0
                                                                   mutex_lock(&fs_info->scrub_lock)
                                                                   (...)
                                                                   mutex_lock(&fs_info->scrub_lock)
                                                                   scrub_free_ctx(sctx)
                                                                      kfree(sctx)
          spin_unlock_irqrestore(&sctx->list_wait->lock, flags)

Fix this by holding the scrub lock while doing the wakeup.

This isn't a recent regression, the issue as been around since the scrub
feature was added (2011, commit a2de733c78fa7af51ba9670482fa7d392aa67c57).

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>

Btrfs: add missing cleanup on sysfs init failure

If we failed during initialization of sysfs, we weren't unregistering the
top level btrfs sysfs entry nor the debugfs stuff.
Not unregistering the top level sysfs entry makes future attempts to reload
the btrfs module impossible and the following is reported in dmesg:

[ 2246.451296] WARNING: CPU: 3 PID: 10999 at fs/sysfs/dir.c:486 sysfs_warn_dup+0x91/0xb0()
[ 2246.451298] sysfs: cannot create duplicate filename '/fs/btrfs'
[ 2246.451298] Modules linked in: btrfs(+) raid6_pq xor bnep rfcomm bluetooth binfmt_misc nfsd auth_rpcgss oid_registry nfs_acl nfs lockd fscache sunrpc parport_pc parport psmouse serio_raw pcspkr evbug i2c_piix4 e1000 floppy [last unloaded: btrfs]
[ 2246.451310] CPU: 3 PID: 10999 Comm: modprobe Tainted: G        W    3.13.0-fdm-btrfs-next-24+ #7
[ 2246.451311] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[ 2246.451312]  0000000000000009 ffff8800d353fa08 ffffffff816f1da6 0000000000000410
[ 2246.451314]  ffff8800d353fa58 ffff8800d353fa48 ffffffff8104a32c ffff88020821a290
[ 2246.451316]  ffff88020821a290 ffff88020821a290 ffff8802148f0000 ffff8800d353fb80
[ 2246.451318] Call Trace:
[ 2246.451322]  [<ffffffff816f1da6>] dump_stack+0x4e/0x68
[ 2246.451324]  [<ffffffff8104a32c>] warn_slowpath_common+0x8c/0xc0
[ 2246.451325]  [<ffffffff8104a416>] warn_slowpath_fmt+0x46/0x50
[ 2246.451328]  [<ffffffff81367dc5>] ? strlcat+0x65/0x90
(....)

This fixes the following change:

    btrfs: add simple debugfs interface
    commit 1bae30982bc86ab66d61ccb6e22792593b45d44d

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>

Btrfs: fix race between transaction commit and empty block group removal

Committing a transaction can race with automatic removal of empty block
groups (cleaner kthread), leading to a BUG_ON() in the transaction
commit code while running btrfs_finish_extent_commit(). The following
sequence diagram shows how it can happen:

           CPU 1                                       CPU 2

btrfs_commit_transaction()
  fs_info->running_transaction = NULL
  btrfs_finish_extent_commit()
    find_first_extent_bit()
      -> found range for block group X
         in fs_info->freed_extents[]

                                               btrfs_delete_unused_bgs()
                                                 -> found block group X

                                                 Removed block group X's range
                                                 from fs_info->freed_extents[]

                                                 btrfs_remove_chunk()
                                                    btrfs_remove_block_group(bg X)

    unpin_extent_range(bg X range)
       btrfs_lookup_block_group(bg X)
          -> returns NULL
            -> BUG_ON()

The trace that results from the BUG_ON() is:

[48665.187808] ------------[ cut here ]------------
[48665.188032] kernel BUG at fs/btrfs/extent-tree.c:5675!
[48665.188032] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC
[48665.188032] Modules linked in: dm_flakey dm_mod crc32c_generic btrfs xor raid6_pq nfsd auth_rpcgss oid_registry nfs_acl nfs lockd grace fscache sunrpc loop parport_pc evdev microcode
[48665.197388] CPU: 2 PID: 31211 Comm: kworker/u32:16 Tainted: G        W      3.19.0-rc5-btrfs-next-4+ #1
[48665.197388] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5-0-ge51488c-20140602_164612-nilsson.home.kraxel.org 04/01/2014
[48665.197388] Workqueue: events_unbound btrfs_async_reclaim_metadata_space [btrfs]
[48665.197388] task: ffff880222011810 ti: ffff8801b56a4000 task.ti: ffff8801b56a4000
[48665.197388] RIP: 0010:[<ffffffffa0350d05>]  [<ffffffffa0350d05>] unpin_extent_range+0x6a/0x1ba [btrfs]
[48665.197388] RSP: 0018:ffff8801b56a7b88  EFLAGS: 00010246
[48665.197388] RAX: 0000000000000000 RBX: ffff8802143a6000 RCX: ffff8802220120c8
[48665.197388] RDX: 0000000000000001 RSI: 0000000000000001 RDI: ffff8800a3c140b0
[48665.197388] RBP: ffff8801b56a7bd8 R08: 0000000000000003 R09: 0000000000000000
[48665.197388] R10: 0000000000000000 R11: 000000000000bbac R12: 0000000012e8e000
[48665.197388] R13: ffff8800a3c14000 R14: 0000000000000000 R15: 0000000000000000
[48665.197388] FS:  0000000000000000(0000) GS:ffff88023ec40000(0000) knlGS:0000000000000000
[48665.197388] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[48665.197388] CR2: 00007f065e42f270 CR3: 0000000206f70000 CR4: 00000000000006e0
[48665.197388] Stack:
[48665.197388]  ffff8801b56a7bd8 0000000012ea0000 01ff8800a3c14138 0000000012e9ffff
[48665.197388]  ffff880141df3dd8 ffff8802143a6000 ffff8800a3c14138 ffff880141df3df0
[48665.197388]  ffff880141df3dd8 0000000000000000 ffff8801b56a7c08 ffffffffa0354227
[48665.197388] Call Trace:
[48665.197388]  [<ffffffffa0354227>] btrfs_finish_extent_commit+0xb0/0xd9 [btrfs]
[48665.197388]  [<ffffffffa0366b4b>] btrfs_commit_transaction+0x791/0x92c [btrfs]
[48665.197388]  [<ffffffffa0352432>] flush_space+0x43d/0x452 [btrfs]
[48665.197388]  [<ffffffff814295c3>] ? _raw_spin_unlock+0x28/0x33
[48665.197388]  [<ffffffffa035255f>] btrfs_async_reclaim_metadata_space+0x118/0x164 [btrfs]
[48665.197388]  [<ffffffff81059917>] ? process_one_work+0x14b/0x3ab
[48665.197388]  [<ffffffff810599ac>] process_one_work+0x1e0/0x3ab
[48665.197388]  [<ffffffff81079fa9>] ? trace_hardirqs_off+0xd/0xf
[48665.197388]  [<ffffffff8105a55b>] worker_thread+0x210/0x2d0
[48665.197388]  [<ffffffff8105a34b>] ? rescuer_thread+0x2c3/0x2c3
[48665.197388]  [<ffffffff8105e5c0>] kthread+0xef/0xf7
[48665.197388]  [<ffffffff81429682>] ? _raw_spin_unlock_irq+0x2d/0x39
[48665.197388]  [<ffffffff8105e4d1>] ? __kthread_parkme+0xad/0xad
[48665.197388]  [<ffffffff81429dec>] ret_from_fork+0x7c/0xb0
[48665.197388]  [<ffffffff8105e4d1>] ? __kthread_parkme+0xad/0xad
[48665.197388] Code: 85 f6 74 14 49 8b 06 49 03 46 09 49 39 c4 72 1d 4c 89 f7 e8 83 ec ff ff 4c 89 e6 4c 89 ef e8 1e f1 ff ff 48 85 c0 49 89 c6 75 02 <0f> 0b 49 8b 1e 49 03 5e 09 48 8b
[48665.197388] RIP  [<ffffffffa0350d05>] unpin_extent_range+0x6a/0x1ba [btrfs]
[48665.197388]  RSP <ffff8801b56a7b88>
[48665.272246] ---[ end trace b9c6ab9957521376 ]---

Fix this by ensuring that unpining the block group's range in
btrfs_finish_extent_commit() is done in a synchronized fashion
with removing the block group's range from freed_extents[]
in btrfs_delete_unused_bgs()

This race got introduced with the change:

    Btrfs: remove empty block groups automatically
    commit 47ab2a6c689913db23ccae38349714edf8365e0a

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>

btrfs: add more checks to btrfs_read_sys_array

Verify that the sys_array has enough bytes to read the next item.

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>

btrfs: cleanup, rename a few variables in btrfs_read_sys_array

There's a pointer to buffer, integer offset and offset passed as
pointer, try to find matching names for them.

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>

btrfs: add checks for sys_chunk_array sizes

Verify that possible minimum and maximum size is set, validity of
contents is checked in btrfs_read_sys_array.

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>

btrfs: more superblock checks, lower bounds on devices and sectorsize/nodesize

I received a few crafted images from Jiri, all got through the recently
added superblock checks. The lower bounds checks for num_devices and
sector/node -sizes were missing and caused a crash during mount.

Tools for symbolic code execution were used to prepare the images
contents.

Reported-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>

Btrfs: Add code to support file creation time

This patch adds a new member to the 'struct btrfs_inode' structure to hold
the file creation time.

Signed-off-by: chandan <chandanrmail@gmail.com>
[refreshed, removed btrfs_inode_otime]
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>

btrfs: kill btrfs_inode_*time helpers

They just opencode taking address of the timespec member.

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>

Btrfs: insert_new_root: Fix lock type of the extent buffer.

btrfs_alloc_tree_block() returns an extent buffer on which a blocked lock has
been taken. Hence assign the appropriate value to path->locks[level].

Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
Signed-off-by: Chris Mason <clm@fb.com>

Btrfs: fix unused members in struct btrfs_root

There isn't any real use of following members of struct btrfs_root
so delete them.

struct kobject root_kobj;
struct completion kobj_unregister;

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>

btrfs: qgroup: move WARN_ON() to the correct location.

In function qgroup_excl_accounting(), we need to WARN when
qg->excl is less than what we want to free, same to child
and parents. But currently, for parent qgroup, the WARN_ON()
is located after freeing qg->excl. It will WARN out even we
free it normally.

This patch move this WARN_ON() before freeing qg->excl.

Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Reviewed-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>

Btrfs: cleanup unused run_most

"run_most" is not used anymore.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>

Rename all ref_count to refs in struct

refs is better than ref_count to record a struct's ref count.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Suggested-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>

Btrfs: Introduce BTRFS_BLOCK_GROUP_RAID56_MASK to check raid56 simply

So we can check raid56 with:
(map->type & BTRFS_BLOCK_GROUP_RAID56_MASK)
instead of long:
(map->type & (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6))

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>

Btrfs: Include map_type in raid_bio

Corrent code use many kinds of "clever" way to determine operation
target's raid type, as:
  raid_map != NULL
  or
  raid_map[MAX_NR] == RAID[56]_Q_STRIPE

To make code easy to maintenance, this patch put raid type into
bbio, and we can always get raid type from bbio with a "stupid"
way.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>

Btrfs: Simplify scrub_setup_recheck_block()'s argument

scrub_setup_recheck_block() have many arguments but most of them
can be get from one of them, we can remove them to make code clean.
Some other cleanup for that function also included in this patch.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>

Btrfs: Combine per-page recover in dev-replace and scrub

The code are similar, combine them to make code clean and easy to maintenance.
Some lost condition are also completed with benefit of this combination.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>

Btrfs: Separate finding-right-mirror and writing-to-target's process in scrub_handle_errored_block()

In corrent code, code of finding-right-mirror and writing-to-target
are mixed in logic, if we find a right mirror but failed in writing
to target, it will treat as "hadn't found right block", and fill the
target with sblock_bad.

Actually, "failed in writing to target" does not mean "source
block is wrong", this patch separate above two condition in logic,
and do some cleanup to make code clean.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>

Btrfs: Break loop when reach BTRFS_MAX_MIRRORS in scrub_setup_recheck_block()

Use break instead of useless loop should be more suitable in this
case.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>

Btrfs: btrfs_rm_dev_replace_blocked(): Use wait_event()

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>

Btrfs: Cleanup btrfs_bio_counter_inc_blocked()

1: Remove no-need DEFINE_WAIT(wait)
2: Add likely() for BTRFS_FS_STATE_DEV_REPLACING condition
3: Use while loop instead of goto

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>

Btrfs: Remove noneed force_write in scrub_write_block_to_dev_replace

It is always 1 in this place, because !1 case was already jumped
out in previous code.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>

Btrfs: Fix a jump typo of nodatasum_case to avoid wrong WARN_ON()

if (sctx->is_dev_replace && !is_metadata && !have_csum) {
    ...
    goto nodatasum_case;
}
...
nodatasum_case:
    WARN_ON(sctx->is_dev_replace);

In above code, nodatasum_case marker should be moved after
WARN_ON().

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>

Btrfs: add ref_count and free function for btrfs_bio

1: ref_count is simple than current RBIO_HOLD_BBIO_MAP_BIT flag
to keep btrfs_bio's memory in raid56 recovery implement.
2: free function for bbio will make code clean and flexible, plus
forced data type checking in compile.

Changelog v1->v2:
Rename following by David Sterba's suggestion:
put_btrfs_bio() -> btrfs_put_bio()
get_btrfs_bio() -> btrfs_get_bio()
bbio->ref_count -> bbio->refs

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>

Btrfs: Make raid_map array be inlined in btrfs_bio structure

It can make code more simple and clear, we need not care about
free bbio and raid_map together.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>

Btrfs: sort raid_map before adding tgtdev stripes

It can avoid complex calculation of real stripes in sort,
moreover, we can clean up code of sorting tgtdev_map because it
will be in order initially.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>

Btrfs: fix a out-of-bound access of raid_map

We add the number of stripes on target devices into bbio->num_stripes
if we are under device replacement, and we just sort the raid_map of
those stripes that not on the target devices, so if when we need
real raid_map, we need skip the stripes on the target devices.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>

Btrfs: fix fsync log replay for inodes with a mix of regular refs and extrefs

If we have an inode with a large number of hard links, some of which may
be extrefs, turn a regular ref into an extref, fsync the inode and then
replay the fsync log (after a crash/reboot), we can endup with an fsync
log that makes the replay code always fail with -EOVERFLOW when processing
the inode's references.

This is easy to reproduce with the test case I made for xfstests. Its steps
are the following:

   _scratch_mkfs "-O extref" >> $seqres.full 2>&1
   _init_flakey
   _mount_flakey

   # Create a test file with 3001 hard links. This number is large enough to
   # make btrfs start using extrefs at some point even if the fs has the maximum
   # possible leaf/node size (64Kb).
   echo "hello world" > $SCRATCH_MNT/foo
   for i in `seq 1 3000`; do
       ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_`printf "%04d" $i`
   done

   # Make sure all metadata and data are durably persisted.
   sync

   # Now remove one link, add a new one with a new name, add another new one with
   # the same name as the one we just removed and fsync the inode.
   rm -f $SCRATCH_MNT/foo_link_0001
   ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_3001
   ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_0001
   rm -f $SCRATCH_MNT/foo_link_0002
   ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_3002
   ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_3003
   $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo

   # Simulate a crash/power loss. This makes sure the next mount
   # will see an fsync log and will replay that log.

   _load_flakey_table $FLAKEY_DROP_WRITES
   _unmount_flakey

   _load_flakey_table $FLAKEY_ALLOW_WRITES
   _mount_flakey

   # Check that the number of hard links is correct, we are able to remove all
   # the hard links and read the file's data. This is just to verify we don't
   # get stale file handle errors (due to dangling directory index entries that
   # point to inodes that no longer exist).
   echo "Link count: $(stat --format=%h $SCRATCH_MNT/foo)"
   [ -f $SCRATCH_MNT/foo ] || echo "Link foo is missing"
   for ((i = 1; i <= 3003; i++)); do
       name=foo_link_`printf "%04d" $i`
       if [ $i -eq 2 ]; then
           [ -f $SCRATCH_MNT/$name ] && echo "Link $name found"
       else
           [ -f $SCRATCH_MNT/$name ] || echo "Link $name is missing"
       fi
   done
   rm -f $SCRATCH_MNT/foo_link_*
   cat $SCRATCH_MNT/foo
   rm -f $SCRATCH_MNT/foo

   status=0
   exit

The fix is simply to correct the overflow condition when overwriting a
reference item because it was wrong, trying to increase the item in the
fs/subvol tree by an impossible amount. Also ensure that we don't insert
one normal ref and one ext ref for the same dentry - this happened because
processing a dir index entry from the parent in the log happened when
the normal ref item was full, which made the logic insert an extref and
later when the normal ref had enough room, it would be inserted again
when processing the ref item from the child inode in the log.

This issue has been present since the introduction of the extrefs feature
(2012).

A test case for xfstests follows soon. This test only passes if the previous
patch titled "Btrfs: fix fsync when extend references are added to an inode"
is applied too.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>

Btrfs: fix fsync when extend references are added to an inode

If we added an extended reference to an inode and fsync'ed it, the log
replay code would make our inode have an incorrect link count, which
was lower then the expected/correct count.
This resulted in stale directory index entries after deleting some of
the hard links, and any access to the dangling directory entries resulted
in -ESTALE errors because the entries pointed to inode items that don't
exist anymore.

This is easy to reproduce with the test case I made for xfstests, and
the bulk of that test is:

    _scratch_mkfs "-O extref" >> $seqres.full 2>&1
    _init_flakey
    _mount_flakey

    # Create a test file with 3001 hard links. This number is large enough to
    # make btrfs start using extrefs at some point even if the fs has the maximum
    # possible leaf/node size (64Kb).
    echo "hello world" > $SCRATCH_MNT/foo
    for i in `seq 1 3000`; do
        ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_`printf "%04d" $i`
    done

    # Make sure all metadata and data are durably persisted.
    sync

    # Add one more link to the inode that ends up being a btrfs extref and fsync
    # the inode.
    ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_3001
    $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo

    # Simulate a crash/power loss. This makes sure the next mount
    # will see an fsync log and will replay that log.

    _load_flakey_table $FLAKEY_DROP_WRITES
    _unmount_flakey

    _load_flakey_table $FLAKEY_ALLOW_WRITES
    _mount_flakey

    # Now after the fsync log replay btrfs left our inode with a wrong link count N,
    # which was smaller than the correct link count M (N < M).
    # So after removing N hard links, the remaining M - N directory entries were
    # still visible to user space but it was impossible to do anything with them
    # because they pointed to an inode that didn't exist anymore. This resulted in
    # stale file handle errors (-ESTALE) when accessing those dentries for example.
    #
    # So remove all hard links except the first one and then attempt to read the
    # file, to verify we don't get an -ESTALE error when accessing the inodel
    #
    # The btrfs fsck tool also detected the incorrect inode link count and it
    # reported an error message like the following:
    #
    # root 5 inode 257 errors 2001, no inode item, link count wrong
    #   unresolved ref dir 256 index 2978 namelen 13 name foo_link_2976 filetype 1 errors 4, no inode ref
    #
    # The fstests framework automatically calls fsck after a test is run, so we
    # don't need to call fsck explicitly here.

    rm -f $SCRATCH_MNT/foo_link_*
    cat $SCRATCH_MNT/foo

    status=0
    exit

So make sure an fsync always flushes the delayed inode item, so that the
fsync log contains it (needed in order to trigger the link count fixup
code) and fix the extref counting function, which always return -ENOENT
to its caller (and made it assume there were always 0 extrefs).

This issue has been present since the introduction of the extrefs feature
(2012).

A test case for xfstests follows soon.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>

Btrfs: fix directory inconsistency after fsync log replay

If we have an inode (file) with a link count greater than 1, remove
one of its hard links, fsync the inode, power fail/crash and then
replay the fsync log on the next mount, we end up getting the parent
directory's metadata inconsistent - its i_size still reflects the
deleted hard link and has dangling index entries (with no matching
inode reference entries). This prevents the directory from ever being
deletable, as its i_size can never decrease to BTRFS_EMPTY_DIR_SIZE
even if all of its children inodes are deleted, and the dangling index
entries can never be removed (as they point to an inode that does not
exist anymore).

This is easy to reproduce with the following excerpt from the test case
for xfstests that I just made:

    _scratch_mkfs >> $seqres.full 2>&1

    _init_flakey
    _mount_flakey

    # Create a test file with 2 hard links in the same directory.
    mkdir -p $SCRATCH_MNT/a/b
    echo "hello world" > $SCRATCH_MNT/a/b/foo
    ln $SCRATCH_MNT/a/b/foo $SCRATCH_MNT/a/b/bar

    # Make sure all metadata and data are durably persisted.
    sync

    # Now remove one of the hard links and fsync the inode.
    rm -f $SCRATCH_MNT/a/b/bar
    $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/a/b/foo

    # Simulate a crash/power loss. This makes sure the next mount
    # will see an fsync log and will replay that log.

    _load_flakey_table $FLAKEY_DROP_WRITES
    _unmount_flakey

    _load_flakey_table $FLAKEY_ALLOW_WRITES
    _mount_flakey

    # Remove the last hard link of the file and attempt to remove its parent
    # directory - this failed in btrfs because the fsync log and replay code
    # didn't decrement the parent directory's i_size and left dangling directory
    # index entries - this made the btrfs rmdir implementation always fail with
    # the error -ENOTEMPTY.
    #
    # The dangling directory index entries were visible to user space, but it was
    # impossible to do anything on them (unlink, open, read, write, stat, etc)
    # because the inode they pointed to did not exist anymore.
    #
    # The parent directory's metadata inconsistency (stale index entries) was
    # also detected by btrfs' fsck tool, which is run automatically by the fstests
    # framework when the test finishes. The error message reported by fsck was:
    #
    # root 5 inode 259 errors 2001, no inode item, link count wrong
    #   unresolved ref dir 258 index 3 namelen 3 name bar filetype 1 errors 4, no inode ref
    #
    rm -f $SCRATCH_MNT/a/b/*
    rmdir $SCRATCH_MNT/a/b
    rmdir $SCRATCH_MNT/a

To fix this just make sure that after an unlink, if the inode is fsync'ed,
he parent inode is fully logged in the fsync log.

A test case for xfstests follows soon.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>

Btrfs: lookup for block group only if needed when freeing a tree block

Very often our extent buffer's header generation doesn't match the current
transaction's id or it is also referenced by other trees (snapshots), so
we don't need the corresponding block group cache object. Therefore only
search for it if we are going to use it, so we avoid an unnecessary search
in the block groups rbtree (and acquiring and releasing its spinlock).

Freeing a tree block is performed when COWing or deleting a node/leaf,
which implies we are holding the node/leaf's parent node lock, therefore
reducing the amount of time spent when freeing a tree block helps reducing
the amount of time we are holding the parent node's lock.

For example, for a run of xfstests/generic/083, the block group cache
object was needed only 682 times for a total of 226691 calls to free
a tree block.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>

btrfs: remove a no-op unfreeze superbock callback

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>

btrfs: switch extent_state state to unsigned

Currently there's a 4B hole in the structure between refs and state and there
are only 16 bits used so we can make it unsigned. This will get a better
packing and may save some stack space for local variables.

The size of extent_state gets reduced by 8B and there are usually a lot
of slab objects.

struct extent_state {
u64                        start;                /*     0     8 */
u64                        end;                  /*     8     8 */
struct rb_node             rb_node;              /*    16    24 */
wait_queue_head_t          wq;                   /*    40    24 */
/* --- cacheline 1 boundary (64 bytes) --- */
atomic_t                   refs;                 /*    64     4 */

/* XXX 4 bytes hole, try to pack */

long unsigned int          state;                /*    72     8 */
u64                        private;              /*    80     8 */

/* size: 88, cachelines: 2, members: 7 */
/* sum members: 84, holes: 1, sum holes: 4 */
/* last cacheline: 24 bytes */
};

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>

btrfs: set proper message level for skinny metadata

This has been confusing people for too long, the message is really just
informative.

CC: <stable@vger.kernel.org> # 3.10+
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>

btrfs: update message levels after checksum errors

The errors are worth noting and might get missed with INFO level.

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>

btrfs: update message levels during failed mount

All error conditions from open_ctree shall be ERR. Warning would
suggest that something's wrong and we can continue.

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>

btrfs: update message levels for errors

Several messages that point to some internal problem, level INFO is
wrong here.

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>

Btrfs: fix setup_leaf_for_split() to avoid leaf corruption

We were incorrectly detecting when the target key didn't exist anymore
after releasing the path and re-searching the tree. This could make
us split or duplicate (btrfs_split_item() and btrfs_duplicate_item()
are its only callers at the moment) an item when we should not.

For the case of duplicating an item, we currently only duplicate
checksum items (csum tree) and file extent items (fs/subvol trees).
For the checksum items we end up overriding the item completely,
but for file extent items we update only some of their fields in
the copy (done in __btrfs_drop_extents), which means we can end up
having a logical corruption for some values.

Also for the case where we duplicate a file extent item it will make
us produce a leaf with a wrong key order, as btrfs_duplicate_item()
advances us to the next slot and then its caller sets a smaller key
on the new item at that slot (like in __btrfs_drop_extents() e.g.).
Alternatively if the tree search in setup_leaf_for_split() leaves
with path->slots[0] == btrfs_header_nritems(path->nodes[0]), we end
up accessing beyond the leaf's end (when we check if the item's size
has changed) and make our caller insert an item at the invalid slot
btrfs_header_nritems(path->nodes[0]) + 1, causing an invalid memory
access if the leaf is full or nearly full.

This issue has been present since the introduction of this function
in 2009:

Btrfs: Add btrfs_duplicate_item
commit ad48fd754676bfae4139be1a897b1ea58f9aaf21

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>

Merge branch 'cleanup/blocksize-diet-part2' of git://git./linux/kernel/git/kdave/linux into for-linus

Merge branch 'fix/find-item-path-leak' of git://git./linux/kernel/git/kdave/linux into for-linus

Btrfs: track dirty block groups on their own list

Currently any time we try to update the block groups on disk we will walk _all_
block groups and check for the ->dirty flag to see if it is set.  This function
can get called several times during a commit.  So if you have several terabytes
of data you will be a very sad panda as we will loop through _all_ of the block
groups several times, which makes the commit take a while which slows down the
rest of the file system operations.

This patch introduces a dirty list for the block groups that we get added to
when we dirty the block group for the first time.  Then we simply update any
block groups that have been dirtied since the last time we called
btrfs_write_dirty_block_groups.  This allows us to clean up how we write the
free space cache out so it is much cleaner.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>

Btrfs: change how we track dirty roots

I've been overloading root->dirty_list to keep track of dirty roots and which
roots need to have their commit roots switched at transaction commit time.  This
could cause us to lose an update to the root which could corrupt the file
system.  To fix this use a state bit to know if the root is dirty, and if it
isn't set we go ahead and move the root to the dirty list.  This way if we
re-dirty the root after adding it to the switch_commit list we make sure to
update it.  This also makes it so that the extent root is always the last root
on the dirty list to try and keep the amount of churn down at this point in the
commit.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>

Linux 3.19-rc5

Merge tag 'armsoc-for-linus' of git://git./linux/kernel/git/arm/arm-soc

Pull ARM SoC fixes from Olof Johansson:
"We've been sitting on our fixes branch for a while, so this batch is
  unfortunately on the large side.

  A lot of these are tweaks and fixes to device trees, fixing various
  bugs around clocks, reg ranges, etc.  There's also a few defconfig
  updates (which are on the late side, no more of those).

  All in all the diffstat is bigger than ideal at this time, but nothing
  in here seems particularly risky"

* tag 'armsoc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (31 commits)
  reset: sunxi: fix spinlock initialization
  ARM: dts: disable CCI on exynos5420 based arndale-octa
  drivers: bus: check cci device tree node status
  ARM: rockchip: disable jtag/sdmmc autoswitching on rk3288
  ARM: nomadik: fix up leftover device tree pins
  ARM: at91: board-dt-sama5: add phy_fixup to override NAND_Tree
  ARM: at91/dt: sam9263: Add missing clocks to lcdc node
  ARM: at91: sama5d3: dt: correct the sound route
  ARM: at91/dt: sama5d4: fix the timer reg length
  ARM: exynos_defconfig: Enable LM90 driver
  ARM: exynos_defconfig: Enable options for display panel support
  arm: dts: Use pmu_system_controller phandle for dp phy
  ARM: shmobile: sh73a0 legacy: Set .control_parent for all irqpin instances
  ARM: dts: berlin: correct BG2Q's SM GPIO location.
  ARM: dts: berlin: add broken-cd and set bus width for eMMC in Marvell DMP DT
  ARM: dts: berlin: fix io clk and add missing core clk for BG2Q sdhci2 host
  ARM: dts: Revert disabling of smc91x for n900
  ARM: dts: imx51-babbage: Fix ULPI PHY reset modelling
  ARM: dts: dra7-evm: fix qspi device tree partition size
  ARM: omap2plus_defconfig: use CONFIG_CPUFREQ_DT
  ...

Merge tag 'clk-fixes-for-linus' of git://git.linaro.org/people/mike.turquette/linux

Pull clock driver fixes from Mike Turquette:
"Small number of fixes for clock drivers and a single null pointer
  dereference fix in the framework core code.

  The driver fixes vary from fixing section mismatch warnings to
  preventing machines from hanging (and preventing developers from
  crying)"

* tag 'clk-fixes-for-linus' of git://git.linaro.org/people/mike.turquette/linux:
  clk: fix possible null pointer dereference
  Revert "clk: ppc-corenet: Fix Section mismatch warning"
  clk: rockchip: fix deadlock possibility in cpuclk
  clk: berlin: bg2q: remove non-exist "smemc" gate clock
  clk: at91: keep slow clk enabled to prevent system hang
  clk: rockchip: fix rk3288 cpuclk core dividers
  clk: rockchip: fix rk3066 pll lock bit location
  clk: rockchip: Fix clock gate for rk3188 hclk_emem_peri
  clk: rockchip: add CLK_IGNORE_UNUSED flag to fix rk3066/rk3188 USB Host

Merge tag 'scsi-fixes' of git://git./linux/kernel/git/jejb/scsi

Pull SCSI fixes from James Bottomley:
"This is one fix for a Multiqueue sleeping in invalid context problem
  and a MAINTAINER file update for Qlogic"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: ->queue_rq can't sleep
  MAINTAINERS: Update maintainer list for qla4xxx

clk: fix possible null pointer dereference

The commit 646cafc6 (clk: Change clk_ops->determine_rate to
return a clk_hw as the best parent) opens a possibility for
null pointer dereference, fix this.

Signed-off-by: Stanimir Varbanov <svarbanov@mm-sol.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Michael Turquette <mturquette@linaro.org>

Revert "clk: ppc-corenet: Fix Section mismatch warning"

This reverts commit da788acb28386aa896224e784954bb73c99ff26c.

That commit tried to fix the section mismatch warning by moving the
ppc_corenet_clk_driver struct to init section. This is definitely wrong
because the kernel would free the memories occupied by this struct
after boot while this driver is still registered in the driver core.
The kernel would panic when accessing this driver struct.

Cc: stable@vger.kernel.org # 3.17
Signed-off-by: Kevin Hao <haokexin@gmail.com>
Acked-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Michael Turquette <mturquette@linaro.org>

clk: rockchip: fix deadlock possibility in cpuclk

Lockdep reported a possible deadlock between the cpuclk lock and for example
the i2c driver.

       CPU0                    CPU1
       ----                    ----
  lock(clk_lock);
                               local_irq_disable();
                               lock(&(&i2c->lock)->rlock);
                               lock(clk_lock);
  <Interrupt>
    lock(&(&i2c->lock)->rlock);

*** DEADLOCK ***

The generic clock-types of the core ccf already use spin_lock_irqsave when
touching clock registers, so do the same for the cpuclk.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
[mturquette@linaro.org: removed initialization of "flags"]

Merge branch 'fixes' of git://git.infradead.org/users/vkoul/slave-dma

Pull dmaengine fixes from Vinod Koul:
"Two patches, the first by Andy to fix dw dmac runtime pm and second
  one by me to fix the dmaengine headers in MAINTAINERS"

* 'fixes' of git://git.infradead.org/users/vkoul/slave-dma:
  dmaengine: dw: balance PM runtime calls
  MAINTAINERS: dmaengine: fix the header file for dmaengine

Merge branch 'perf-urgent-for-linus' of git://git./linux/kernel/git/tip/tip

Pull perf fixes from Ingo Molnar:
"Mostly tooling fixes, but also two PMU driver fixes"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf tools powerpc: Use dwfl_report_elf() instead of offline.
  perf tools: Fix segfault for symbol annotation on TUI
  perf test: Fix dwarf unwind using libunwind.
  perf tools: Avoid build splat for syscall numbers with uclibc
  perf tools: Elide strlcpy warning with uclibc
  perf tools: Fix statfs.f_type data type mismatch build error with uclibc
  tools: Remove bitops/hweight usage of bits in tools/perf
  perf machine: Fix __machine__findnew_thread() error path
  perf tools: Fix building error in x86_64 when dwarf unwind is on
  perf probe: Propagate error code when write(2) failed
  perf/x86/intel: Fix bug for "cycles:p" and "cycles:pp" on SLM
  perf/rapl: Fix sysfs_show() initialization for RAPL PMU

Merge tag 'perf-urgent-for-mingo' of git://git./linux/kernel/git/acme/linux into perf/urgent

Pull perf/urgent fixes from Arnaldo Carvalho de Melo:

  - Fix segfault when using both the map symtab viewer and annotation
    in the TUI (Namhyung Kim).

  - uClibc build fixes (Alexey Brodkin, Vineet Gupta).

  - bitops/hweight were moved from tools/perf/ too tools/include, move
    some leftovers (Arnaldo Carvalho de Melo)

  - Fix dwarf unwind x86_64 build error (Namhyung Kim)

  - Fix __machine__findnew_thread() error path (Namhyung Kim)

  - Propagate error code when write(2) failed in 'perf probe' (Namhyung Kim)

  - Use dwfl_report_elf() instead of offline in powerpc bits to
    properly handle non prelinked DSOs (Sukadev Bhattiprolu).

  - Fix dwarf unwind using libunwind in 'perf test' (Wang Nan)

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Merge tag 'samsung-fixes-3.19' of git://git./linux/kernel/git/kgene/linux-samsung into fixes

Merge "Samsung fixes for v3.19" from Kukjin Kim:

Samsung fixes for v3.19
- exynos_defconfig: enable LM90 driver and display panel support
   - HWMON
   - SENSORS_LM90
   - Direct Rendering Manager (DRM)
   - DRM bridge registration and lookup framework
   - Parade ps8622/ps8625 eDP/LVDS bridge
   - NXP ptn3460 eDP/LVDS bridge
   - Exynos Fully Interactive Mobile Display controller (FIMD)
   - Panel registration and lookup framework
   - Simple panels
   - Backlight & LCD device support

- use pmu_system_controller phandle for dp phy
  : DP PHY requires pmu_system_controller to handle PMU reg. now

* tag 'samsung-fixes-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/kgene/linux-samsung:
  ARM: exynos_defconfig: Enable LM90 driver
  ARM: exynos_defconfig: Enable options for display panel support
  arm: dts: Use pmu_system_controller phandle for dp phy

Signed-off-by: Olof Johansson <olof@lixom.net>

reset: sunxi: fix spinlock initialization

Call spin_lock_init() before the spinlocks are used, both in early init
and probe functions preventing a lockdep splat.

I have been observing lockdep complaining [1] during boot on my a80 optimus [2]
when CONFIG_PROVE_LOCKING has been enabled. This patch resolves the splat,
and has been tested on a few other sunxi platforms without issue.

[1] http://storage.kernelci.org/next/next-20150107/arm-multi_v7_defconfig+CONFIG_PROVE_LOCKING=y/lab-tbaker/boot-sun9i-a80-optimus.html
[2] http://kernelci.org/boot/?a80-optimus

Signed-off-by: Tyler Baker <tyler.baker@linaro.org>
Cc: <stable@vger.kernel.org>
Acked-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Olof Johansson <olof@lixom.net>

Merge tag 'renesas-soc-fixes-for-v3.19' of git://git./linux/kernel/git/horms/renesas into fixes

Merge "Renesas ARM Based SoC Fixes for v3.19" from Simon Horman:

Renesas ARM Based SoC Fixes for v3.19

This pull request is based on the last round of SoC updates for v3.19,
Fourth Round of Renesas ARM Based SoC Updates for v3.19, tagged as
renesas-soc3-for-v3.19, merged into your next/soc branch and included in
v3.19-rc1.

- ARM: shmobile: r8a7740: Instantiate GIC from C board code in legacy builds

  Set .control_parent for all irqpin instances for sh73a0 SoC when booting
  using legacy C.

- ARM: shmobile: r8a7740: Instantiate GIC from C board code in legacy builds

  This fixes a long standing problem which has been present since
  the sh73a0 SoC started using the INTC External IRQ pin driver.

  The patch that introduced the problem is 341eb5465f67437a ("ARM:
  shmobile: INTC External IRQ pin driver on sh73a0") which was included
  in v3.10.

* tag 'renesas-soc-fixes-for-v3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas:
  ARM: shmobile: sh73a0 legacy: Set .control_parent for all irqpin instances
  ARM: shmobile: r8a7740: Instantiate GIC from C board code in legacy builds

ARM: dts: disable CCI on exynos5420 based arndale-octa

The arndale-octa board was giving "imprecise external aborts" during
boot-up with MCPM enabled. CCI enablement of the boot cluster was found
to be the cause of these aborts (possibly because the secure f/w was not
allowing it). Hence, disable CCI for the arndale-octa board.

Signed-off-by: Abhilash Kesavan <a.kesavan@samsung.com>
Tested-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Tested-by: Kevin Hilman <khilman@linaro.org>
Tested-by: Tyler Baker <tyler.baker@linaro.org>
Signed-off-by: Olof Johansson <olof@lixom.net>

drivers: bus: check cci device tree node status

The arm-cci driver completes the probe sequence even if the cci node is
marked as disabled. Add a check in the driver to honour the cci status
in the device tree.

Signed-off-by: Abhilash Kesavan <a.kesavan@samsung.com>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Sudeep Holla <sudeep.holla@arm.com>
Tested-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Olof Johansson <olof@lixom.net>

Merge tag 'at91-fixes' of git://git./linux/kernel/git/nferre/linux-at91 into fixes

Merge "at91: fixes for 3.19 #1 (ter)" from Nicolas Ferre:

First fixes batch for AT91 on 3.19:
- fix some DT entries
- correct clock entry for the at91sam9263 LCD
- add a phy_fixup for Eth1 on sama5d4

* tag 'at91-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nferre/linux-at91:
  ARM: at91: board-dt-sama5: add phy_fixup to override NAND_Tree
  ARM: at91/dt: sam9263: Add missing clocks to lcdc node
  ARM: at91: sama5d3: dt: correct the sound route
  ARM: at91/dt: sama5d4: fix the timer reg length

Signed-off-by: Olof Johansson <olof@lixom.net>

ARM: rockchip: disable jtag/sdmmc autoswitching on rk3288

rk3288 SoCs have a function to automatically switch between jtag/sdmmc pinmux
settings depending on the card state. This collides with a lot of assumptions.

It only works when using the internal card-detect mechanism and breaks
horribly when using either the normal card-detect via the slot-gpio function
or via any other pin. Also there is of course no link between the mmc and jtag
on the software-side, so the jtag clocks may very well be disabled when the
card is ejected and the soc switches back to the jtag pinmux.

Leaving the switching function enabled did result in mmc timeouts and rcu
stalls thus hanging the system on 3.19-rc1. Therefore disable it in all cases,
as we expect the devicetree to explicitly select either mmc or jtag pinmuxes
anyway.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Olof Johansson <olof@lixom.net>

Merge tag 'berlin-fixes-for-3.19-1' of git://git.infradead.org/users/hesselba/linux-berlin into fixes

Merge "ARM: berlin: Fixes for v3.19 (round 1)" from Sebastian Hesselbarth:

Marvell Berlin fixes for v3.19 round 1:
- SDHCI DT fixes for BG2Q and BG2Q reference board
- BG2Q SM GPIO DT node relocation

* tag 'berlin-fixes-for-3.19-1' of git://git.infradead.org/users/hesselba/linux-berlin:
  ARM: dts: berlin: correct BG2Q's SM GPIO location.
  ARM: dts: berlin: add broken-cd and set bus width for eMMC in Marvell DMP DT
  ARM: dts: berlin: fix io clk and add missing core clk for BG2Q sdhci2 host

Signed-off-by: Olof Johansson <olof@lixom.net>

ARM: nomadik: fix up leftover device tree pins

We altered the device tree bindings for the Nomadik family of
pin controllers to be standard, this file was merged out-of-order
so we missed fixing this. Fix it up.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Olof Johansson <olof@lixom.net>

Merge tag 'omap-for-v3.19/fixes-rc1' of git://git./linux/kernel/git/tmlind/linux-omap into fixes

Merge "omap fixes against v3.19-rc1" from Tony Lindgren:

Fixes for omaps mostly to deal with dra7 timer issues
and hypervisor mode. The other fixes are minor fixes for
various boards. The summary of the fixes is:

- Fix real-time counter rate typos for some frequencies
- Fix counter frequency drift for am572x
- Fix booting of secondary CPU in HYP mode
- Fix n900 board name for legacy user space
- Fix cpufreq in omap2plus_defconfig after Kconfig change
- Fix dra7 qspi partitions

And also, let's re-enable smc91x on some n900 boards that
we have sitting in a few test boot systems after the boot
loader dependencies got fixed.

* tag 'omap-for-v3.19/fixes-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap:
  ARM: dts: Revert disabling of smc91x for n900
  ARM: dts: dra7-evm: fix qspi device tree partition size
  ARM: omap2plus_defconfig: use CONFIG_CPUFREQ_DT
  ARM: OMAP2+: Fix n900 board name for legacy user space
  ARM: omap5/dra7xx: Enable booting secondary CPU in HYP mode
  ARM: dra7xx: Fix counter frequency drift for AM572x errata i856
  ARM: omap5/dra7xx: Fix frequency typos

Signed-off-by: Olof Johansson <olof@lixom.net>

Merge tag 'imx-fixes-3.19' of git://git./linux/kernel/git/shawnguo/linux into fixes

Merge "ARM: imx: fixes for 3.19" from Shawn Guo:

The i.MX fixes for 3.19:
- One fix for incorrect i.MX25 SPI1 clock assignment in device tree,
   which causes system hang when accessing SPI1.
- Correct i.MX6SX QSPI parent clock configuration to fix a kernel Oops.
- Fix ULPI PHY reset modelling on imx51-babbage board to remove the
   dependency on bootloader for USB3317 ULPI PHY reset.
- Correct video divider setting on i.MX6Q rev T0 1.0 to fix the issue
   that HDMI is not working at high resolution on T0 1.0.
- One incremental fix for CODA960 VPU enabling in device tree to
   correct interrupt order.
- LS1021A SCFG block works in BE mode, add device tree property
   big-endian to make it right.

* tag 'imx-fixes-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/shawnguo/linux:
  ARM: dts: imx51-babbage: Fix ULPI PHY reset modelling
  ARM: imx6sx: Set PLL2 as parent of QSPI clocks
  ARM: dts: imx25: Fix the SPI1 clocks
  ARM: clk-imx6q: fix video divider for rev T0 1.0
  ARM: dts: imx6qdl: Fix CODA960 interrupt order
  ARM: ls1021a: dtsi: add 'big-endian' property for scfg node

Signed-off-by: Olof Johansson <olof@lixom.net>

Merge tag 'v3.19-rockchip-dtsfixes1' of git://git./linux/kernel/git/mmind/linux-rockchip into fixes

Merge "ARM: rockchip: dts fix for 3.19" from Heiko Stübner:

Increase drive-strength to sdmmc pins on rk3288-evb to fix
an issue with the fixed highspeed card detection.

* tag 'v3.19-rockchip-dtsfixes1' of git://git.kernel.org/pub/scm/linux/kernel/git/mmind/linux-rockchip:
ARM: dts: rockchip: bump sd card pin drive strength up on rk3288-evb

Signed-off-by: Olof Johansson <olof@lixom.net>

kernel: avoid overflow in cmp_range

Avoid overflow possibility.

[ The overflow is purely theoretical, since this is used for memory
ranges that aren't even close to using the full 64 bits, but this is
the right thing to do regardless. - Linus ]

Signed-off-by: Louis Langholtz <lou_langholtz@me.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Peter Anvin <hpa@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

perf tools powerpc: Use dwfl_report_elf() instead of offline.

dwfl_report_offline() works only when libraries are prelinked.

Replace dwfl_report_offline() with dwfl_report_elf() so we correctly
extract debug info even from libraries that are not prelinked.

Reported-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Tested-by: Jiri Olsa <jolsa@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Link: http://lkml.kernel.org/r/20150114221045.GA17703@us.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf tools: Fix segfault for symbol annotation on TUI

Currently the symbol structure is allocated with symbol_conf.priv_size
to carry sideband information like annotation, map browser on TUI and
sort-by-name tree node.  So retrieving these information from symbol
needs to care about the details of such placement.

However the annotation code just assumes that the symbol is placed after
the struct annotation.  But actually there's other info between them.
So accessing those struct will lead to an undefined behavior (usually a
crash) after they write their info to the same location.

To reproduce the problem, please follow the steps below:

  1. run perf report (TUI of course) with -v option
  2. open map browser (by pressing right arrow key for any entry)
  3. search any function (by pressing '/' key and input whatever..)
  4. return to the hist browser (by pressing 'q' or left arrow key)
  5. open annotation window for the same entry (by pressing 'a' key)

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1421234288-22758-1-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf test: Fix dwarf unwind using libunwind.

Perf tool fails to unwind user stack if the event raises in a shared
object. This patch improves tests/dwarf-unwind.c to demonstrate the
problem by utilizing commonly used glibc function "bsearch". If perf is
not statically linked, the testcase will try to unwind a mixed call
trace.

By debugging libunwind I found that there is a bug in unwind-libunwind:
it always passes 0 as segbase to libunwind, cause libunwind unable to
locate debug_frame entry fir first level ip address (I add some more
debugging output into libunwind to make things clear):

               >_Uarm_dwarf_find_debug_frame: start_ip = 10be98, end_ip = 10c2a4
               >_Uarm_dwarf_find_debug_frame: found debug_frame table `/lib/libc-2.18.so': segbase=0x0, len=7, gp=0x0, table_data=0x449388
               >_Uarm_dwarf_search_unwind_table: call lookup:ip = b6cd3bcc, segbase = 0, rel_ip = b6cd3bcc
               >lookup: e->start_ip_offset = bcf18 (rel_ip = b6cd3bcc)
               >lookup: e->start_ip_offset = 6d314 (rel_ip = b6cd3bcc)
               >lookup: e->start_ip_offset = 33d0c (rel_ip = b6cd3bcc)
                ...
               >lookup: e->start_ip_offset = 15d0c (rel_ip = b6cd3bcc)
               >lookup: e->start_ip_offset = 15c40 (rel_ip = b6cd3bcc)
>_Uarm_dwarf_search_unwind_table: IP b6cd3bcc inside range b6c12000-b6d4c000, but no explicit unwind info found
                >put_rs_cache: unmasking signals/interrupts and releasing lock
               >_Uarm_dwarf_step: returning -10
>_Uarm_step: dwarf_step()=-10

This patch passes map->start as segbase to dwarf_find_debug_frame(), so
di will be initialized correctly.

In addition, dso and executable are different when setting segbase. This
patch first check whether the elf is executable, and pass segbase only
for shared object.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1421203007-75799-1-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf tools: Avoid build splat for syscall numbers with uclibc

This is due to duplicated unistd inclusion (via uClibc headers + kernel headers)
Also seen on ARM uClibc based tools

   ------- ARC build ---------->8-------------

  CC       util/evlist.o
In file included from
~/arc/k.org/arch/arc/include/uapi/asm/unistd.h:25:0,
                 from util/../perf-sys.h:10,
                 from util/../perf.h:15,
                 from util/event.h:7,
                 from util/event.c:3:
~/arc/k.org/include/uapi/asm-generic/unistd.h:906:0:
warning: "__NR_fcntl64" redefined [enabled by default]
#define __NR_fcntl64 __NR3264_fcntl
^
In file included from
~/arc/gnu/INSTALL_1412-arc-2014.12-rc1/arc-snps-linux-uclibc/sysroot/usr/include/sys/syscall.h:24:0,
                 from util/../perf-sys.h:6,
   ----------------->8-------------------

   ------- ARM build ---------->8-------------

  CC FPIC  plugin_scsi.o
In file included from util/../perf-sys.h:9:0,
                 from util/../perf.h:15,
                 from util/cache.h:7,
                 from perf.c:12:
~/arc/k.org/arch/arm/include/uapi/asm/unistd.h:28:0:
warning: "__NR_restart_syscall" redefined [enabled by default]
In file included from
~/buildroot/host/usr/arm-buildroot-linux-uclibcgnueabi/sysroot/usr/include/sys/syscall.h:25:0,
                 from util/../perf-sys.h:6,
                 from util/../perf.h:15,
                 from util/cache.h:7,
                 from perf.c:12:
~/buildroot/host/usr/arm-buildroot-linux-uclibcgnueabi/sysroot/usr/include/bits/sysnum.h:17:0:
note: this is the location of the previous definition
   ----------------->8-------------------

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Alexey Brodkin <Alexey.Brodkin@synopsys.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1421156604-30603-4-git-send-email-vgupta@synopsys.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf tools: Elide strlcpy warning with uclibc

   ----------------->8------------------
  CC       bench/sched-pipe.o
In file included from builtin-annotate.c:13:0:
util/cache.h:76:15: warning: redundant redeclaration of 'strlcpy'
[-Wredundant-decls]
extern size_t strlcpy(char *dest, const char *src, size_t size);
               ^
In file included from util/util.h:55:0,
                 from builtin.h:4,
                 from builtin-annotate.c:8:
~/vineetg/arc/gnu/INSTALL_1412-arc-2014.12-rc1/arc-snps-linux-uclibc/sysroot/usr/include/string.h:396:15:
note: previous declaration of 'strlcpy' was here
extern size_t strlcpy(char *__restrict dst, const char *__restrict src,
   ----------------->8------------------

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Alexey Brodkin <Alexey.Brodkin@synopsys.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1421156604-30603-3-git-send-email-vgupta@synopsys.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf tools: Fix statfs.f_type data type mismatch build error with uclibc

ARC Linux uses the no legacy syscalls abi and corresponding uClibc headers
statfs defines f_type to be U32 which causes perf build breakage

http://git.uclibc.org/uClibc/tree/libc/sysdeps/linux/common-generic/bits/statfs.h

  ----------->8---------------
    CC       fs/fs.o
  fs/fs.c: In function 'fs__valid_mount':
  fs/fs.c:82:24: error: comparison between signed and unsigned integer
  expressions [-Werror=sign-compare]
    else if (st_fs.f_type != magic)
                          ^
  cc1: all warnings being treated as errors
  ----------->8---------------

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Cody P Schafer <dev@codyps.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Vineet Gupta <Vineet.Gupta1@synopsys.com>
Link: http://lkml.kernel.org/r/1420888254-17504-2-git-send-email-vgupta@synopsys.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools: Remove bitops/hweight usage of bits in tools/perf

We need to use lib/hweight.c for that, just like we do for lib/rbtree.c,
so tools need to link hweight.o. For now do it directly, but we need to
have a tools/lib/lk.a or .so that collects these goodies...

Reported-by: Jan Beulich <JBeulich@suse.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-a1e91dx3apzqw5kbdt7ut21s@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf machine: Fix __machine__findnew_thread() error path

When thread__init_map_groups() fails, a new thread should be removed
from the rbtree since it's gonna be freed. Also update last match cache
only if the function succeeded.

Reported-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1420763892-15535-1-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf tools: Fix building error in x86_64 when dwarf unwind is on

When build with 'make ARCH=x86' and dwarf unwind is on, there is a
compiling error:

CC /home/wn/perf/arch/x86/util/unwind-libdw.o
CC /home/wn/perf/arch/x86/tests/regs_load.o
arch/x86/tests/regs_load.S: Assembler messages:
arch/x86/tests/regs_load.S:65: Error: operand type mismatch for `push'
arch/x86/tests/regs_load.S:72: Error: operand type mismatch for `pop'
make[1]: *** [/home/wn/perf/arch/x86/tests/regs_load.o] Error 1
make[1]: INTERNAL: Exiting with 25 jobserver tokens available; should be 24!
make: *** [all] Error 2
...

Which is caused by incorrectly undefine macro HAVE_ARCH_X86_64_SUPPORT.
'config/Makefile.arch' tests __x86_64__ only when 'ARCH=x86_64'.
However, when building x86_64 kernel, ARCH=x86 is valid and commonly
used. Build systems, such as yocto, uses x86_64 compiler with 'ARCH=x86'
to build x86_64 perf, which causes mismatching.

As __LP64__ is defined for x86_64 as well, we can consolidate the
__x86_64__ check to the __LP64__ check and get rid of the IS_X86_64
IMHO.

(This patch is made by Namhyung Kim when replying my v1 patch:

https://lkml.org/lkml/2015/1/7/17

I modified the code to remove dependency on RAW_ARCH:

https://lkml.org/lkml/2015/1/7/865

Namhyung Kim didn't provide his SOB in his original email. I add
mine only for my modification.)

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1421029255-23039-1-git-send-email-wangnan0@huawei.com
[ Namhyung provided his S-o-B on a followup to this patch thread on lkml ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf probe: Propagate error code when write(2) failed

When it failed to write probe commands to the probe_event file in
debugfs, it needs to propagate the error code properly. Current code
blindly uses the return value of the write(2) so it always uses
-1 (-EPERM) and it might confuse users.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1420886028-15135-4-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Merge tag 'char-misc-3.19-rc5' of git://git./linux/kernel/git/gregkh/char-misc

Pull char/misc driver fixes from Greg KH:
"Here are three small driver fixes for reported issues for 3.19-rc5.

  All of these have been in linux-next for a while with no reported
  problems"

* tag 'char-misc-3.19-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  mcb: mcb-pci: Only remap the 1st 0x200 bytes of BAR 0
  mei: add ABI documentation for fw_status exported through sysfs
  mei: clean reset bit before reset

Merge tag 'driver-core-3.19-rc5' of git://git./linux/kernel/git/gregkh/driver-core

Pull driver core fix from Greg KH:
"Here is one kernfs fix for a reported issue for 3.19-rc5.

It has been in linux-next for a while"

* tag 'driver-core-3.19-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
kernfs: Fix kernfs_name_compare

Merge tag 'tty-3.19-rc5' of git://git./linux/kernel/git/gregkh/tty

Pull tty/serial driver fixes from Greg KH:
"Here are some tty and serial driver fixes for 3.19-rc5 that resolve
  some reported issues, and add a new device id to the 8250 serial port
  driver.

  All have been in linux-next with no reported problems"

* tag 'tty-3.19-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  serial: samsung: Add the support for Exynos5433 SoC
  Revert "tty: Fix pty master poll() after slave closes v2"
  tty: Prevent hw state corruption in exclusive mode reopen
  tty: Add support for the WCH384 4S multi-IO card
  serial: fix parisc boot hang

Merge tag 'staging-3.19-rc5' of git://git./linux/kernel/git/gregkh/staging

Pull staging driver fixes from Greg KH:
"Here are 6 staging driver fixes for 3.19-rc5.

  They fix some reported issues with some IIO drivers, as well as some
  issues with the vt6655 wireless driver.

  All have been in linux-next for a while"

* tag 'staging-3.19-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  staging: vt6655: fix sparse warning: argument type
  staging: vt6655: Fix loss of distant/weak access points on channel change.
  staging: vt6655: vnt_tx_packet Fix corrupted tx packets.
  staging: vt6655: fix sparse warnings: incorrect argument type
  iio: iio: Fix iio_channel_read return if channel havn't info
  iio: ad799x: Fix ad7991/ad7995/ad7999 config setup

Merge tag 'usb-3.19-rc5' of git://git./linux/kernel/git/gregkh/usb

Pull USB fixes from Greg KH:
"Here is a bunch of USB fixes for 3.19-rc5.

  Most of these are gadget driver fixes, along with the xhci driver fix
  that we both reported having problems with, as well as some new device
  ids and other tiny fixes.

  All have been in linux-next with no problems"

* tag 'usb-3.19-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (43 commits)
  usb: dwc3: gadget: Stop TRB preparation after limit is reached
  usb: dwc3: gadget: Fix TRB preparation during SG
  usb: phy: mv-usb: fix usb_phy build errors
  usb: serial: handle -ENODEV quietly in generic_submit_read_urb
  usb: serial: silence all non-critical read errors
  USB: console: fix potential use after free
  USB: console: fix uninitialised ldisc semaphore
  usb: gadget: udc: atmel: fix possible oops when unloading module
  usb: gadget: gadgetfs: fix an oops in ep_write()
  usb: phy: Fix deferred probing
  OHCI: add a quirk for ULi M5237 blocking on reset
  uas: Add US_FL_NO_ATA_1X for 2 more Seagate disk enclosures
  uas: Do not blacklist ASM1153 disk enclosures
  usb: gadget: udc: avoid dereference before NULL check in ep_queue
  usb: host: ehci-tegra: request deferred probe when failing to get phy
  uas: disable UAS on Apricorn SATA dongles
  uas: Add US_FL_NO_REPORT_OPCODES for JMicron JMS566 with usb-id 0bc2:a013
  uas: Add US_FL_NO_ATA_1X for Seagate devices with usb-id 0bc2:a013
  xhci: Add broken-streams quirk for Fresco Logic FL1000G xhci controllers
  USB: EHCI: adjust error return code
  ...

Merge tag 'arm64-fixes' of git://git./linux/kernel/git/arm64/linux

Pull arm64 fixes from Will Deacon:
- Wire up compat_sys_execveat for compat (AArch32) tasks
- Revert 421520ba9829, as this breaks our side of the boot protocol

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
arm64: partially revert "ARM: 8167/1: extend the reserved memory for initrd to be page aligned"
arm64: compat: wire up compat_sys_execveat

Merge tag 'nfs-for-3.19-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

Pull NFS client bugfixes from Trond Myklebust:
"Highlights include:

   - Stable fix for a NFSv3/lockd race
   - Fixes for several NFSv4.1 client id trunking bugs
   - Remove an incorrect test when checking for delegated opens"

* tag 'nfs-for-3.19-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  NFSv4: Remove incorrect check in can_open_delegated()
  NFS: Ignore transport protocol when detecting server trunking
  NFSv4/v4.1: Verify the client owner id during trunking detection
  NFSv4: Cache the NFSv4/v4.1 client owner_id in the struct nfs_client
  NFSv4.1: Fix client id trunking on Linux
  LOCKD: Fix a race when initialising nlmsvc_timeout

Merge tag 'trace-fixes-v3.19-rc3' of git://git./linux/kernel/git/rostedt/linux-trace

Pull ftrace fixes from Steven Rostedt:
"This holds a few fixes to the ftrace infrastructure as well as the
  mixture of function graph tracing and kprobes.

  When jprobes and function graph tracing is enabled at the same time it
  will crash the system:

      # modprobe jprobe_example
      # echo function_graph > /sys/kernel/debug/tracing/current_tracer

  After the first fork (jprobe_example probes it), the system will
  crash.

  This is due to the way jprobes copies the stack frame and does not do
  a normal function return.  This messes up with the function graph
  tracing accounting which hijacks the return address from the stack and
  replaces it with a hook function.  It saves the return addresses in a
  separate stack to put back the correct return address when done.  But
  because the jprobe functions do not do a normal return, their stack
  addresses are not put back until the function they probe is called,
  which means that the probed function will get the return address of
  the jprobe handler instead of its own.

  The simple fix here was to disable function graph tracing while the
  jprobe handler is being called.

  While debugging this I found two minor bugs with the function graph
  tracing.

  The first was about the function graph tracer sharing its function
  hash with the function tracer (they both get filtered by the same
  input).  The changing of the set_ftrace_filter would not sync the
  function recording records after a change if the function tracer was
  disabled but the function graph tracer was enabled.  This was due to
  the update only checking one of the ops instead of the shared ops to
  see if they were enabled and should perform the sync.  This caused the
  ftrace accounting to break and a ftrace_bug() would be triggered,
  disabling ftrace until a reboot.

  The second was that the check to update records only checked one of
  the filter hashes.  It needs to test both the "filter" and "notrace"
  hashes.  The "filter" hash determines what functions to trace where as
  the "notrace" hash determines what functions not to trace (trace all
  but these).  Both hashes need to be passed to the update code to find
  out what change is being done during the update.  This also broke the
  ftrace record accounting and triggered a ftrace_bug().

  This patch set also include two more fixes that were reported
  separately from the kprobe issue.

  One was that init_ftrace_syscalls() was called twice at boot up.  This
  is not a major bug, but that call performed a rather large kmalloc
  (NR_syscalls * sizeof(*syscalls_metadata)).  The second call made the
  first one a memory leak, and wastes memory.

  The other fix is a regression caused by an update in the v3.19 merge
  window.  The moving to enable events early, moved the enabling before
  PID 1 was created.  The syscall events require setting the
  TIF_SYSCALL_TRACEPOINT for all tasks.  But for_each_process_thread()
  does not include the swapper task (PID 0), and ended up being a nop.

  A suggested fix was to add the init_task() to have its flag set, but I
  didn't really want to mess with PID 0 for this minor bug.  Instead I
  disable and re-enable events again at early_initcall() where it use to
  be enabled.  This also handles any other event that might have its own
  reg function that could break at early boot up"

* tag 'trace-fixes-v3.19-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Fix enabling of syscall events on the command line
  tracing: Remove extra call to init_ftrace_syscalls()
  ftrace/jprobes/x86: Fix conflict between jprobes and function graph tracing
  ftrace: Check both notrace and filter for old hash
  ftrace: Fix updating of filters for shared global_ops filters

arm64: partially revert "ARM: 8167/1: extend the reserved memory for initrd to be page aligned"

This patch partially reverts commit 421520ba98290a73b35b7644e877a48f18e06004
(only the arm64 part). There is no guarantee that the boot-loader places other
images like dtb in a different page than initrd start/end, especially when the
kernel is built with 64KB pages. When this happens, such pages must not be
freed. The free_reserved_area() already takes care of rounding up "start" and
rounding down "end" to avoid freeing partially used pages.

Cc: <stable@vger.kernel.org> # 3.17+
Reported-by: Peter Maydell <Peter.Maydell@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

perf/x86/intel: Fix bug for "cycles:p" and "cycles:pp" on SLM

cycles:p and cycles:pp do not work on SLM since commit:

86a04461a99f ("perf/x86: Revamp PEBS event selection")

UOPS_RETIRED.ALL is not a PEBS capable event, so it should not be used
to count cycle number.

Actually SLM calls intel_pebs_aliases_core2() which uses INST_RETIRED.ANY_P
to count the number of cycles. It's a PEBS capable event. But inv and
cmask must be set to count cycles.

Considering SLM allows all events as PEBS with no flags, only
INST_RETIRED.ANY_P, inv=1, cmask=16 needs to handled specially.

Signed-off-by: Kan Liang <kan.liang@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1421084541-31639-1-git-send-email-kan.liang@intel.com
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

perf/rapl: Fix sysfs_show() initialization for RAPL PMU

This patch fixes a problem with the initialization of the
sysfs_show() routine for the RAPL PMU.

The current code was wrongly relying on the EVENT_ATTR_STR()
macro which uses the events_sysfs_show() function in the x86
PMU code. That function itself was relying on the x86_pmu data
structure. Yet RAPL and the core PMU (x86_pmu) have nothing to
do with each other. They should therefore not interact with
each other.

The x86_pmu structure is initialized at boot time based on
the host CPU model. When the host CPU is not supported, the
x86_pmu remains uninitialized and some of the callbacks it
contains are NULL.

The false dependency with x86_pmu could potentially cause crashes
in case the x86_pmu is not initialized while the RAPL PMU is. This
may, for instance, be the case in virtualized environments.

This patch fixes the problem by using a private sysfs_show()
routine for exporting the RAPL PMU events.

Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20150113225953.GA21525@thinkpad
Cc: vincent.weaver@maine.edu
Cc: jolsa@redhat.com
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Merge branch 'for-linus' of git://git./linux/kernel/git/mszeredi/fuse

Pull fuse fixes from Miklos Szeredi:
"This fixes a regression in the latest fuse update plus a fix for a
  rather theoretical memory ordering issue"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  fuse: add memory barrier to INIT
  fuse: fix LOOKUP vs INIT compat handling

Merge tag 'fbdev-fixes-3.19' of git://git./linux/kernel/git/tomba/linux

Pull fbdev fixes from Tomi Valkeinen:
- broadsheetfb: fix memory leak
- simplefb: fix build failure on sparc

* tag 'fbdev-fixes-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tomba/linux:
fbdev/broadsheetfb: fix memory leak
simplefb: Fix build failure on Sparc

Merge tag 'mmc-v3.19-4' of git://git.linaro.org/people/ulf.hansson/mmc

Pull MMC bugfix from Ulf Hansson:
"Fix sdhci regulator regression for Qualcomm and Nvidia boards"

* tag 'mmc-v3.19-4' of git://git.linaro.org/people/ulf.hansson/mmc:
mmc: sdhci: Set SDHCI_POWER_ON with external vmmc

Merge branch 'for-linus' of git://git./linux/kernel/git/geert/linux-m68k

Pull m68k fixlet from Geert Uytterhoeven.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k:
m68k: Wire up execveat

Merge tag 'powerpc-3.19-4' of git://git./linux/kernel/git/mpe/linux

Pull powerpc fixes from Michael Ellerman:
"A few powerpc fixes"

* tag 'powerpc-3.19-4' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux:
  powerpc: Work around gcc bug in current_thread_info()
  cxl: Fix issues when unmapping contexts
  powernv: Fix OPAL tracepoint code

tracing: Fix enabling of syscall events on the command line

Commit 5f893b2639b2 "tracing: Move enabling tracepoints to just after
rcu_init()" broke the enabling of system call events from the command
line. The reason was that the enabling of command line trace events
was moved before PID 1 started, and the syscall tracepoints require
that all tasks have the TIF_SYSCALL_TRACEPOINT flag set. But the
swapper task (pid 0) is not part of that. Since the swapper task is the
only task that is running at this early in boot, no task gets the
flag set, and the tracepoint never gets reached.

Instead of setting the swapper task flag (there should be no reason to
do that), re-enabled trace events again after the init thread (PID 1)
has been started. It requires disabling all command line events and
re-enabling them, as just enabling them again will not reset the logic
to set the TIF_SYSCALL_TRACEPOINT flag, as the syscall tracepoint will
be fooled into thinking that it was already set, and wont try setting
it again. For this reason, we must first disable it and re-enable it.

Link: http://lkml.kernel.org/r/1421188517-18312-1-git-send-email-mpe@ellerman.id.au
Link: http://lkml.kernel.org/r/20150115040506.216066449@goodmis.org
Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

tracing: Remove extra call to init_ftrace_syscalls()

trace_init() calls init_ftrace_syscalls() and then calls trace_event_init()
which also calls init_ftrace_syscalls(). It makes more sense to only
call it from trace_event_init().

Calling it twice wastes memory, as it allocates the syscall events twice,
and loses the first copy of it.

Link: http://lkml.kernel.org/r/54AF53BD.5070303@huawei.com
Link: http://lkml.kernel.org/r/20150115040505.930398632@goodmis.org
Reported-by: Wang Nan <wangnan0@huawei.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

ftrace/jprobes/x86: Fix conflict between jprobes and function graph tracing

If the function graph tracer traces a jprobe callback, the system will
crash. This can easily be demonstrated by compiling the jprobe
sample module that is in the kernel tree, loading it and running the
function graph tracer.

# modprobe jprobe_example.ko
# echo function_graph > /sys/kernel/debug/tracing/current_tracer
# ls

The first two commands end up in a nice crash after the first fork.
(do_fork has a jprobe attached to it, so "ls" just triggers that fork)

The problem is caused by the jprobe_return() that all jprobe callbacks
must end with. The way jprobes works is that the function a jprobe
is attached to has a breakpoint placed at the start of it (or it uses
ftrace if fentry is supported). The breakpoint handler (or ftrace callback)
will copy the stack frame and change the ip address to return to the
jprobe handler instead of the function. The jprobe handler must end
with jprobe_return() which swaps the stack and does an int3 (breakpoint).
This breakpoint handler will then put back the saved stack frame,
simulate the instruction at the beginning of the function it added
a breakpoint to, and then continue on.

For function tracing to work, it hijakes the return address from the
stack frame, and replaces it with a hook function that will trace
the end of the call. This hook function will restore the return
address of the function call.

If the function tracer traces the jprobe handler, the hook function
for that handler will not be called, and its saved return address
will be used for the next function. This will result in a kernel crash.

To solve this, pause function tracing before the jprobe handler is called
and unpause it before it returns back to the function it probed.

Some other updates:

Used a variable "saved_sp" to hold kcb->jprobe_saved_sp. This makes the
code look a bit cleaner and easier to understand (various tries to fix
this bug required this change).

Note, if fentry is being used, jprobes will change the ip address before
the function graph tracer runs and it will not be able to trace the
function that the jprobe is probing.

Link: http://lkml.kernel.org/r/20150114154329.552437962@goodmis.org
Cc: stable@vger.kernel.org # 2.6.30+
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>