commit f9bfe4e6a9d08d405fe7b081ee9a13e649c97ecf upstream.

tcp_tso_should_defer() can return true in three different cases :

 1) We are cwnd-limited
 2) We are rwnd-limited
 3) We are application limited.

Neal pointed out that my recent fix went too far, since
it assumed that if we were not in 1) case, we must be rwnd-limited

Fix this by properly populating the is_cwnd_limited and
is_rwnd_limited booleans.

After this change, we can finally move the silly check for FIN
flag only for the application-limited case.

The same move for EOR bit will be handled in net-next,
since commit 1c09f7d073b1 ("tcp: do not try to defer skbs
with eor mark (MSG_EOR)") is scheduled for linux-4.21

Tested by running 200 concurrent netperf -t TCP_RR -- -r 60000,100
and checking none of them was rwnd_limited in the chrono_stat
output from "ss -ti" command.

Fixes: 41727549de3e ("tcp: Do not underestimate rwnd_limited")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Suggested-by: NNeal Cardwell <ncardwell@google.com>
Reviewed-by: NNeal Cardwell <ncardwell@google.com>
Acked-by: NSoheil Hassas Yeganeh <soheil@google.com>
Reviewed-by: NYuchung Cheng <ycheng@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit afd594240806acc138cf696c09f2f4829d55d02f upstream.

When patching in a new sequence for the first insn of a subprog, the start
 of that subprog does not change (it's the first insn of the sequence), so
 adjust_subprog_starts should check start <= off (rather than < off).
Also added a test to test_verifier.c (it's essentially the syz reproducer).

Fixes: cc8b0b92 ("bpf: introduce function calls (function boundaries)")
Reported-by: syzbot+4fc427c7af994b0948be@syzkaller.appspotmail.com
Signed-off-by: NEdward Cree <ecree@solarflare.com>
Acked-by: NYonghong Song <yhs@fb.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 36d842194a57f1b21fbc6a6875f2fa2f9a7f8679 upstream.

When running with KASAN, the following trace is produced:

[   62.535888]

==================================================================
[   62.544930] BUG: KASAN: slab-out-of-bounds in
gut_hw_stats+0x122/0x230 [hfi1]
[   62.553856] Write of size 8 at addr ffff88080e8d6330 by task
kworker/0:1/14

[   62.565333] CPU: 0 PID: 14 Comm: kworker/0:1 Not tainted
4.19.0-test-build-kasan+ #8
[   62.575087] Hardware name: Intel Corporation S2600KPR/S2600KPR, BIOS
SE5C610.86B.01.01.0019.101220160604 10/12/2016
[   62.587951] Workqueue: events work_for_cpu_fn
[   62.594050] Call Trace:
[   62.598023]  dump_stack+0xc6/0x14c
[   62.603089]  ? dump_stack_print_info.cold.1+0x2f/0x2f
[   62.610041]  ? kmsg_dump_rewind_nolock+0x59/0x59
[   62.616615]  ? get_hw_stats+0x122/0x230 [hfi1]
[   62.622985]  print_address_description+0x6c/0x23c
[   62.629744]  ? get_hw_stats+0x122/0x230 [hfi1]
[   62.636108]  kasan_report.cold.6+0x241/0x308
[   62.642365]  get_hw_stats+0x122/0x230 [hfi1]
[   62.648703]  ? hfi1_alloc_rn+0x40/0x40 [hfi1]
[   62.655088]  ? __kmalloc+0x110/0x240
[   62.660695]  ? hfi1_alloc_rn+0x40/0x40 [hfi1]
[   62.667142]  setup_hw_stats+0xd8/0x430 [ib_core]
[   62.673972]  ? show_hfi+0x50/0x50 [hfi1]
[   62.680026]  ib_device_register_sysfs+0x165/0x180 [ib_core]
[   62.687995]  ib_register_device+0x5a2/0xa10 [ib_core]
[   62.695340]  ? show_hfi+0x50/0x50 [hfi1]
[   62.701421]  ? ib_unregister_device+0x2e0/0x2e0 [ib_core]
[   62.709222]  ? __vmalloc_node_range+0x2d0/0x380
[   62.716131]  ? rvt_driver_mr_init+0x11f/0x2d0 [rdmavt]
[   62.723735]  ? vmalloc_node+0x5c/0x70
[   62.729697]  ? rvt_driver_mr_init+0x11f/0x2d0 [rdmavt]
[   62.737347]  ? rvt_driver_mr_init+0x1f5/0x2d0 [rdmavt]
[   62.744998]  ? __rvt_alloc_mr+0x110/0x110 [rdmavt]
[   62.752315]  ? rvt_rc_error+0x140/0x140 [rdmavt]
[   62.759434]  ? rvt_vma_open+0x30/0x30 [rdmavt]
[   62.766364]  ? mutex_unlock+0x1d/0x40
[   62.772445]  ? kmem_cache_create_usercopy+0x15d/0x230
[   62.780115]  rvt_register_device+0x1f6/0x360 [rdmavt]
[   62.787823]  ? rvt_get_port_immutable+0x180/0x180 [rdmavt]
[   62.796058]  ? __get_txreq+0x400/0x400 [hfi1]
[   62.802969]  ? memcpy+0x34/0x50
[   62.808611]  hfi1_register_ib_device+0xde6/0xeb0 [hfi1]
[   62.816601]  ? hfi1_get_npkeys+0x10/0x10 [hfi1]
[   62.823760]  ? hfi1_init+0x89f/0x9a0 [hfi1]
[   62.830469]  ? hfi1_setup_eagerbufs+0xad0/0xad0 [hfi1]
[   62.838204]  ? pcie_capability_clear_and_set_word+0xcd/0xe0
[   62.846429]  ? pcie_capability_read_word+0xd0/0xd0
[   62.853791]  ? hfi1_pcie_init+0x187/0x4b0 [hfi1]
[   62.860958]  init_one+0x67f/0xae0 [hfi1]
[   62.867301]  ? hfi1_init+0x9a0/0x9a0 [hfi1]
[   62.873876]  ? wait_woken+0x130/0x130
[   62.879860]  ? read_word_at_a_time+0xe/0x20
[   62.886329]  ? strscpy+0x14b/0x280
[   62.891998]  ? hfi1_init+0x9a0/0x9a0 [hfi1]
[   62.898405]  local_pci_probe+0x70/0xd0
[   62.904295]  ? pci_device_shutdown+0x90/0x90
[   62.910833]  work_for_cpu_fn+0x29/0x40
[   62.916750]  process_one_work+0x584/0x960
[   62.922974]  ? rcu_work_rcufn+0x40/0x40
[   62.928991]  ? __schedule+0x396/0xdc0
[   62.934806]  ? __sched_text_start+0x8/0x8
[   62.941020]  ? pick_next_task_fair+0x68b/0xc60
[   62.947674]  ? run_rebalance_domains+0x260/0x260
[   62.954471]  ? __list_add_valid+0x29/0xa0
[   62.960607]  ? move_linked_works+0x1c7/0x230
[   62.967077]  ?
trace_event_raw_event_workqueue_execute_start+0x140/0x140
[   62.976248]  ? mutex_lock+0xa6/0x100
[   62.982029]  ? __mutex_lock_slowpath+0x10/0x10
[   62.988795]  ? __switch_to+0x37a/0x710
[   62.994731]  worker_thread+0x62e/0x9d0
[   63.000602]  ? max_active_store+0xf0/0xf0
[   63.006828]  ? __switch_to_asm+0x40/0x70
[   63.012932]  ? __switch_to_asm+0x34/0x70
[   63.019013]  ? __switch_to_asm+0x40/0x70
[   63.025042]  ? __switch_to_asm+0x34/0x70
[   63.031030]  ? __switch_to_asm+0x40/0x70
[   63.037006]  ? __schedule+0x396/0xdc0
[   63.042660]  ? kmem_cache_alloc_trace+0xf3/0x1f0
[   63.049323]  ? kthread+0x59/0x1d0
[   63.054594]  ? ret_from_fork+0x35/0x40
[   63.060257]  ? __sched_text_start+0x8/0x8
[   63.066212]  ? schedule+0xcf/0x250
[   63.071529]  ? __wake_up_common+0x110/0x350
[   63.077794]  ? __schedule+0xdc0/0xdc0
[   63.083348]  ? wait_woken+0x130/0x130
[   63.088963]  ? finish_task_switch+0x1f1/0x520
[   63.095258]  ? kasan_unpoison_shadow+0x30/0x40
[   63.101792]  ? __init_waitqueue_head+0xa0/0xd0
[   63.108183]  ? replenish_dl_entity.cold.60+0x18/0x18
[   63.115151]  ? _raw_spin_lock_irqsave+0x25/0x50
[   63.121754]  ? max_active_store+0xf0/0xf0
[   63.127753]  kthread+0x1ae/0x1d0
[   63.132894]  ? kthread_bind+0x30/0x30
[   63.138422]  ret_from_fork+0x35/0x40

[   63.146973] Allocated by task 14:
[   63.152077]  kasan_kmalloc+0xbf/0xe0
[   63.157471]  __kmalloc+0x110/0x240
[   63.162804]  init_cntrs+0x34d/0xdf0 [hfi1]
[   63.168883]  hfi1_init_dd+0x29a3/0x2f90 [hfi1]
[   63.175244]  init_one+0x551/0xae0 [hfi1]
[   63.181065]  local_pci_probe+0x70/0xd0
[   63.186759]  work_for_cpu_fn+0x29/0x40
[   63.192310]  process_one_work+0x584/0x960
[   63.198163]  worker_thread+0x62e/0x9d0
[   63.203843]  kthread+0x1ae/0x1d0
[   63.208874]  ret_from_fork+0x35/0x40

[   63.217203] Freed by task 1:
[   63.221844]  __kasan_slab_free+0x12e/0x180
[   63.227844]  kfree+0x92/0x1a0
[   63.232570]  single_release+0x3a/0x60
[   63.238024]  __fput+0x1d9/0x480
[   63.242911]  task_work_run+0x139/0x190
[   63.248440]  exit_to_usermode_loop+0x191/0x1a0
[   63.254814]  do_syscall_64+0x301/0x330
[   63.260283]  entry_SYSCALL_64_after_hwframe+0x44/0xa9

[   63.270199] The buggy address belongs to the object at
ffff88080e8d5500
 which belongs to the cache kmalloc-4096 of size 4096
[   63.287247] The buggy address is located 3632 bytes inside of
 4096-byte region [ffff88080e8d5500, ffff88080e8d6500)
[   63.303564] The buggy address belongs to the page:
[   63.310447] page:ffffea00203a3400 count:1 mapcount:0
mapping:ffff88081380e840 index:0x0 compound_mapcount: 0
[   63.323102] flags: 0x2fffff80008100(slab|head)
[   63.329775] raw: 002fffff80008100 0000000000000000 0000000100000001
ffff88081380e840
[   63.340175] raw: 0000000000000000 0000000000070007 00000001ffffffff
0000000000000000
[   63.350564] page dumped because: kasan: bad access detected

[   63.361974] Memory state around the buggy address:
[   63.369137]  ffff88080e8d6200: 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00
[   63.379082]  ffff88080e8d6280: 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00
[   63.389032] >ffff88080e8d6300: 00 00 00 00 00 00 fc fc fc fc fc fc fc
fc fc fc
[   63.398944]                                      ^
[   63.406141]  ffff88080e8d6380: fc fc fc fc fc fc fc fc fc fc fc fc fc
fc fc fc
[   63.416109]  ffff88080e8d6400: fc fc fc fc fc fc fc fc fc fc fc fc fc
fc fc fc
[   63.426099]
==================================================================

The trace happens because get_hw_stats() assumes there is room in the
memory allocated in init_cntrs() to accommodate the driver counters.
Unfortunately, that routine only allocated space for the device
counters.

Fix by insuring the allocation has room for the additional driver
counters.

Cc: <Stable@vger.kernel.org> # v4.14+
Fixes: b7481944 ("IB/hfi1: Show statistics counters under IB stats interface")
Reviewed-by: NMike Marciniczyn <mike.marciniszyn@intel.com>
Reviewed-by: NMike Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: NPiotr Stankiewicz <piotr.stankiewicz@intel.com>
Signed-off-by: NDennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 6ba189c5c1a4bda70dc1e4826c58b0246068bb8d upstream.

Users reported a mute LED regression on Lenovo X1 Carbon, the root
cause is we applied the fixup of ALC285_FIXUP_LENOVO_HEADPHONE_NOISE
to this machine, then the machine can't apply the fixup of
ALC269_FIXUP_THINKPAD_ACPI anymore. To fix it, we chain two fixup
together.

Fixes: c4cfcf6f4297 ("ALSA: hda/realtek - fix the pop noise on headphone for lenovo laptops")
Cc: <stable@vger.kernel.org>
Signed-off-by: NHui Wang <hui.wang@canonical.com>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 0bea4cc8383519f78f3f74caca7bdebdfb346d3b upstream.

The ASUS UX433FN and UX333FA with ALC294 cannot detect the headset MIC
and output through the internal speaker and the headphone until
ALC294_FIXUP_ASUS_SPK and ALC294_FIXUP_ASUS_HEADSET_MIC quirk applied.
Signed-off-by: NDaniel Drake <drake@endlessm.com>
Signed-off-by: NJian-Hong Pan <jian-hong@endlessm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 4e051106730dfc640a8b49db88440af304726f4d upstream.

The ASUS UX533FD with ALC294 cannot detect the headset MIC and outputs
through the internal speaker and the headphone until
ALC294_FIXUP_ASUS_SPK and ALC294_FIXUP_ASUS_HEADSET_MIC quirk applied.
Signed-off-by: NDaniel Drake <drake@endlessm.com>
Signed-off-by: NJian-Hong Pan <jian-hong@endlessm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit d8ae458eeca9ed686e09a1b894867cb91fc4c1cb upstream.

The known ALC256_FIXUP_ASUS_MIC fixup can fix the headphone jack
sensing and enable use of the internal microphone on this laptop
X542UN. However, it's ALC294 so create a new fixup named
ALC294_FIXUP_ASUS_MIC to avoid confusion.
Signed-off-by: NJian-Hong Pan <jian-hong@endlessm.com>
Signed-off-by: NDaniel Drake <drake@endlessm.com>
Signed-off-by: NChris Chiu <chiu@endlessm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit bde1a7459623a66c2abec4d0a841e4b06cc88d9a upstream.

If it plugged headphone or headset into the jack, then
do the reboot, it will have a chance to cause headphone no sound.
It just need to run the headphone mode procedure after boot time.
The issue will be fixed.
It also suitable for ALC234 ALC274 and ALC294.
Signed-off-by: NKailang Yang <kailang@realtek.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit fa9c98e4b975bb3192ed6af09d9fa282ed3cd8a0 upstream.

In an initial commit, 'SYNC_STATUS' register is referred to get
clock configuration, however this is wrong, according to my local
note at hand for reverse-engineering about packet dump. It should
be 'CLOCK_CONFIG' register. Actually, ff400_dump_clock_config()
is correctly programmed.

This commit fixes the bug.

Cc: <stable@vger.kernel.org> # v4.12+
Fixes: 76fdb3a9 ('ALSA: fireface: add support for Fireface 400')
Signed-off-by: NTakashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit c93db7bb6ef3251e0ea48ade311d3e9942748e1c upstream.

If we race with inode destroy, it's possible for page->mapping to be
NULL before we even enter this routine, as well as after having slept
waiting for the dax entry to become unlocked.

Fixes: c2a7d2a1 ("filesystem-dax: Introduce dax_lock_mapping_entry()")
Cc: <stable@vger.kernel.org>
Reported-by: NJan Kara <jack@suse.cz>
Signed-off-by: NMatthew Wilcox <willy@infradead.org>
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: NJan Kara <jack@suse.cz>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 320f35b7bf8cccf1997ca3126843535e1b95e9c4 upstream.

Since commit bb21ce0ad227 we always enforce per-mirror stateid.
However, this makes sense only for v4+ servers.
Signed-off-by: NTigran Mkrtchyan <tigran.mkrtchyan@desy.de>
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

[ Upstream commit 164f7e586739d07eb56af6f6d66acebb11f315c8 ]

ocfs2_get_dentry() calls iput(inode) to drop the reference count of
inode, and if the reference count hits 0, inode is freed.  However, in
this function, it then reads inode->i_generation, which may result in a
use after free bug.  Move the put operation later.

Link: http://lkml.kernel.org/r/1543109237-110227-1-git-send-email-bianpan2016@163.com
Fixes: 781f200c("ocfs2: Remove masklog ML_EXPORT.")
Signed-off-by: NPan Bian <bianpan2016@163.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <jiangqi903@gmail.com>
Cc: Changwei Ge <ge.changwei@h3c.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>

[ Upstream commit 7c0950d455d6ab610d2990a13120f935b75abf2c ]

sys_link() can fail due to the new path already existing.  This case
ofen occurs when we use a concated initrd, for example:

1) prepare a basic rootfs, it contains a regular files rc.local
lizhijian@:~/yocto-tiny-i386-2016-04-22$ cat etc/rc.local
 #!/bin/sh
 echo "Running /etc/rc.local..."
yocto-tiny-i386-2016-04-22$ find . | sed 's,^\./,,' | cpio -o -H newc | gzip -n -9 >../rootfs.cgz

2) create a extra initrd which also includes a etc/rc.local
lizhijian@:~/lkp-x86_64/etc$ echo "append initrd" >rc.local
lizhijian@:~/lkp/lkp-x86_64/etc$ cat rc.local
append initrd
lizhijian@:~/lkp/lkp-x86_64/etc$ ln rc.local rc.local.hardlink
append initrd
lizhijian@:~/lkp/lkp-x86_64/etc$ stat rc.local rc.local.hardlink
  File: 'rc.local'
  Size: 14        	Blocks: 8          IO Block: 4096   regular file
Device: 801h/2049d	Inode: 11296086    Links: 2
Access: (0664/-rw-rw-r--)  Uid: ( 1002/lizhijian)   Gid: ( 1002/lizhijian)
Access: 2018-11-15 16:08:28.654464815 +0800
Modify: 2018-11-15 16:07:57.514903210 +0800
Change: 2018-11-15 16:08:24.180228872 +0800
 Birth: -
  File: 'rc.local.hardlink'
  Size: 14        	Blocks: 8          IO Block: 4096   regular file
Device: 801h/2049d	Inode: 11296086    Links: 2
Access: (0664/-rw-rw-r--)  Uid: ( 1002/lizhijian)   Gid: ( 1002/lizhijian)
Access: 2018-11-15 16:08:28.654464815 +0800
Modify: 2018-11-15 16:07:57.514903210 +0800
Change: 2018-11-15 16:08:24.180228872 +0800
 Birth: -

lizhijian@:~/lkp/lkp-x86_64$ find . | sed 's,^\./,,' | cpio -o -H newc | gzip -n -9 >../rc-local.cgz
lizhijian@:~/lkp/lkp-x86_64$ gzip -dc ../rc-local.cgz | cpio -t
.
etc
etc/rc.local.hardlink <<< it will be extracted first at this initrd
etc/rc.local

3) concate 2 initrds and boot
lizhijian@:~/lkp$ cat rootfs.cgz rc-local.cgz >concate-initrd.cgz
lizhijian@:~/lkp$ qemu-system-x86_64 -nographic -enable-kvm -cpu host -smp 1 -m 1024 -kernel ~/lkp/linux/arch/x86/boot/bzImage -append "console=ttyS0 earlyprint=ttyS0 ignore_loglevel" -initrd ./concate-initr.cgz -serial stdio -nodefaults

In this case, sys_link(2) will fail and return -EEXIST, so we can only get
the rc.local at rootfs.cgz instead of rc-local.cgz

[akpm@linux-foundation.org: move code to avoid forward declaration]
Link: http://lkml.kernel.org/r/1542352368-13299-1-git-send-email-lizhijian@cn.fujitsu.comSigned-off-by: NLi Zhijian <lizhijian@cn.fujitsu.com>
Cc: Philip Li <philip.li@intel.com>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Li Zhijian <zhijianx.li@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>

[ Upstream commit 903e8ff86753e6f327bb92166a0665e4ecb8e2e7 ]

Since __sanitizer_cov_trace_pc() is marked as notrace, function calls in
__sanitizer_cov_trace_pc() shouldn't be traced either.
ftrace_graph_caller() gets called for each function that isn't marked
'notrace', like canonicalize_ip().  This is the call trace from a run:

[  139.644550]  ftrace_graph_caller+0x1c/0x24
[  139.648352]  canonicalize_ip+0x18/0x28
[  139.652313]  __sanitizer_cov_trace_pc+0x14/0x58
[  139.656184]  sched_clock+0x34/0x1e8
[  139.659759]  trace_clock_local+0x40/0x88
[  139.663722]  ftrace_push_return_trace+0x8c/0x1f0
[  139.667767]  prepare_ftrace_return+0xa8/0x100
[  139.671709]  ftrace_graph_caller+0x1c/0x24

Rework so that check_kcov_mode() and canonicalize_ip() that are called
from __sanitizer_cov_trace_pc() are also marked as notrace.

Link: http://lkml.kernel.org/r/20181128081239.18317-1-anders.roxell@linaro.orgSigned-off-by: NArnd Bergmann <arnd@arndb.de>
Signen-off-by: NAnders Roxell <anders.roxell@linaro.org>
Co-developed-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>

[ Upstream commit dbd4af54745fc0c805217693c807a3928b2d408b ]

https://bugs.linaro.org/show_bug.cgi?id=3782

Turns out arm doesn't permit mapping address 0, so try minimum virtual
address instead.

Link: http://lkml.kernel.org/r/20181113165446.GA28157@avx2Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Reported-by: NRafael David Tinoco <rafael.tinoco@linaro.org>
Tested-by: NRafael David Tinoco <rafael.tinoco@linaro.org>
Acked-by: NCyrill Gorcunov <gorcunov@gmail.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>

[ Upstream commit 8de456cf87ba863e028c4dd01bae44255ce3d835 ]

CONFIG_DEBUG_OBJECTS_RCU_HEAD does not play well with kmemleak due to
recursive calls.

fill_pool
  kmemleak_ignore
    make_black_object
      put_object
        __call_rcu (kernel/rcu/tree.c)
          debug_rcu_head_queue
            debug_object_activate
              debug_object_init
                fill_pool
                  kmemleak_ignore
                    make_black_object
                      ...

So add SLAB_NOLEAKTRACE to kmem_cache_create() to not register newly
allocated debug objects at all.

Link: http://lkml.kernel.org/r/20181126165343.2339-1-cai@gmx.usSigned-off-by: NQian Cai <cai@gmx.us>
Suggested-by: NCatalin Marinas <catalin.marinas@arm.com>
Acked-by: NWaiman Long <longman@redhat.com>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>

[ Upstream commit c7d7d620dcbd2a1c595092280ca943f2fced7bbd ]

hfs_bmap_free() frees node via hfs_bnode_put(node).  However it then
reads node->this when dumping error message on an error path, which may
result in a use-after-free bug.  This patch frees node only when it is
never used.

Link: http://lkml.kernel.org/r/1543053441-66942-1-git-send-email-bianpan2016@163.comSigned-off-by: NPan Bian <bianpan2016@163.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Ernesto A. Fernandez <ernesto.mnd.fernandez@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Viacheslav Dubeyko <slava@dubeyko.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>

[ Upstream commit ce96a407adef126870b3f4a1b73529dd8aa80f49 ]

hfs_bmap_free() frees the node via hfs_bnode_put(node).  However, it
then reads node->this when dumping error message on an error path, which
may result in a use-after-free bug.  This patch frees the node only when
it is never again used.

Link: http://lkml.kernel.org/r/1542963889-128825-1-git-send-email-bianpan2016@163.com
Fixes: a1185ffa2fc ("HFS rewrite")
Signed-off-by: NPan Bian <bianpan2016@163.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Joe Perches <joe@perches.com>
Cc: Ernesto A. Fernandez <ernesto.mnd.fernandez@gmail.com>
Cc: Viacheslav Dubeyko <slava@dubeyko.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>

[ Upstream commit 8f416836 ]

init_currently_empty_zone() will adjust pgdat->nr_zones and set it to
'zone_idx(zone) + 1' unconditionally.  This is correct in the normal
case, while not exact in hot-plug situation.

This function is used in two places:

  * free_area_init_core()
  * move_pfn_range_to_zone()

In the first case, we are sure zone index increase monotonically.  While
in the second one, this is under users control.

One way to reproduce this is:
----------------------------

1. create a virtual machine with empty node1

   -m 4G,slots=32,maxmem=32G \
   -smp 4,maxcpus=8          \
   -numa node,nodeid=0,mem=4G,cpus=0-3 \
   -numa node,nodeid=1,mem=0G,cpus=4-7

2. hot-add cpu 3-7

   cpu-add [3-7]

2. hot-add memory to nod1

   object_add memory-backend-ram,id=ram0,size=1G
   device_add pc-dimm,id=dimm0,memdev=ram0,node=1

3. online memory with following order

   echo online_movable > memory47/state
   echo online > memory40/state

After this, node1 will have its nr_zones equals to (ZONE_NORMAL + 1)
instead of (ZONE_MOVABLE + 1).

Michal said:
 "Having an incorrect nr_zones might result in all sorts of problems
  which would be quite hard to debug (e.g. reclaim not considering the
  movable zone). I do not expect many users would suffer from this it
  but still this is trivial and obviously right thing to do so
  backporting to the stable tree shouldn't be harmful (last famous
  words)"

Link: http://lkml.kernel.org/r/20181117022022.9956-1-richard.weiyang@gmail.com
Fixes: f1dd2cd1 ("mm, memory_hotplug: do not associate hotadded memory to zones until online")
Signed-off-by: NWei Yang <richard.weiyang@gmail.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Reviewed-by: NOscar Salvador <osalvador@suse.de>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>

[ Upstream commit e21e57445a64598b29a6f629688f9b9a39e7242a ]

ocfs2_defrag_extent may fall into deadlock.

ocfs2_ioctl_move_extents
    ocfs2_ioctl_move_extents
      ocfs2_move_extents
        ocfs2_defrag_extent
          ocfs2_lock_allocators_move_extents

            ocfs2_reserve_clusters
              inode_lock GLOBAL_BITMAP_SYSTEM_INODE

	  __ocfs2_flush_truncate_log
              inode_lock GLOBAL_BITMAP_SYSTEM_INODE

As backtrace shows above, ocfs2_reserve_clusters() will call inode_lock
against the global bitmap if local allocator has not sufficient cluters.
Once global bitmap could meet the demand, ocfs2_reserve_cluster will
return success with global bitmap locked.

After ocfs2_reserve_cluster(), if truncate log is full,
__ocfs2_flush_truncate_log() will definitely fall into deadlock because
it needs to inode_lock global bitmap, which has already been locked.

To fix this bug, we could remove from
ocfs2_lock_allocators_move_extents() the code which intends to lock
global allocator, and put the removed code after
__ocfs2_flush_truncate_log().

ocfs2_lock_allocators_move_extents() is referred by 2 places, one is
here, the other does not need the data allocator context, which means
this patch does not affect the caller so far.

Link: http://lkml.kernel.org/r/20181101071422.14470-1-lchen@suse.comSigned-off-by: NLarry Chen <lchen@suse.com>
Reviewed-by: NChangwei Ge <ge.changwei@h3c.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <jiangqi903@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>

[ Upstream commit ea2412dc21cc790335d319181dddc43682aef164 ]

Running the Clang static analyzer on IORT code detected the following
error:

Logic error: Branch condition evaluates to a garbage value

in

iort_get_platform_device_domain()

If the named component associated with a given device has no IORT
mappings, iort_get_platform_device_domain() exits its MSI mapping loop
with msi_parent pointer containing garbage, which can lead to erroneous
code path execution.

Initialize the msi_parent pointer, fixing the bug.

Fixes: d4f54a18 ("ACPI: platform: setup MSI domain for ACPI based
platform device")
Reported-by: NPatrick Bellasi <patrick.bellasi@arm.com>
Reviewed-by: NHanjun Guo <hanjun.guo@linaro.org>
Acked-by: NWill Deacon <will.deacon@arm.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Signed-off-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>

[ Upstream commit 6344d02dc8f886b6bbcd922ae1a17e4a41500f2d ]

Some error paths in configuration of admin queue free data buffer
associated with async request SQE without resetting the data buffer
pointer to NULL, This buffer is also freed up again if the controller
is shutdown or reset.
Signed-off-by: NPrabhath Sajeepa <psajeepa@purestorage.com>
Reviewed-by: NRoland Dreier <roland@purestorage.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NSasha Levin <sashal@kernel.org>

[ Upstream commit f6c8e432cb0479255322c5d0335b9f1699a0270c ]

nvme_stop_ctrl can be called also for reset flow and there is no need to
flush the scan_work as namespaces are not being removed. This can cause
deadlock in rdma, fc and loop drivers since nvme_stop_ctrl barriers
before controller teardown (and specifically I/O cancellation of the
scan_work itself) takes place, but the scan_work will be blocked anyways
so there is no need to flush it.

Instead, move scan_work flush to nvme_remove_namespaces() where it really
needs to flush.
Reported-by: NMing Lei <ming.lei@redhat.com>
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NKeith Busch <keith.busch@intel.com>
Reviewed by: James Smart <jsmart2021@gmail.com>
Tested-by: NEwan D. Milne <emilne@redhat.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NSasha Levin <sashal@kernel.org>

[ Upstream commit 14a1336e6fff47dd1028b484d6c802105c58e2ee ]

Without CONFIG_NVME_MULTIPATH enabled a multi-port subsystem might
show up as invididual devices and cause problems, warn about it.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Signed-off-by: NSasha Levin <sashal@kernel.org>

[ Upstream commit 31ffa563833576bd49a8bf53120568312755e6e2 ]

Variable 'cache' is being assigned but is never used hence it is
redundant and can be removed.

Cleans up clang warning:
warning: variable 'cache' set but not used [-Wunused-but-set-variable]
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>

[ Upstream commit b7e768b7e3522695ed36dcb48ecdcd344bd30a9b ]

Clang warns when one enumerated type is implicitly converted to another.

fs/cachefiles/namei.c:247:50: warning: implicit conversion from
enumeration type 'enum cachefiles_obj_ref_trace' to different
enumeration type 'enum fscache_obj_ref_trace' [-Wenum-conversion]
        cache->cache.ops->put_object(&xobject->fscache,
cachefiles_obj_put_wait_retry);

Silence this warning by explicitly casting to fscache_obj_ref_trace,
which is also done in put_object.
Reported-by: NNick Desaulniers <ndesaulniers@google.com>
Signed-off-by: NNathan Chancellor <natechancellor@gmail.com>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>

[ Upstream commit c5a94f434c82529afda290df3235e4d85873c5b4 ]

It was observed that a process blocked indefintely in
__fscache_read_or_alloc_page(), waiting for FSCACHE_COOKIE_LOOKING_UP
to be cleared via fscache_wait_for_deferred_lookup().

At this time, ->backing_objects was empty, which would normaly prevent
__fscache_read_or_alloc_page() from getting to the point of waiting.
This implies that ->backing_objects was cleared *after*
__fscache_read_or_alloc_page was was entered.

When an object is "killed" and then "dropped",
FSCACHE_COOKIE_LOOKING_UP is cleared in fscache_lookup_failure(), then
KILL_OBJECT and DROP_OBJECT are "called" and only in DROP_OBJECT is
->backing_objects cleared.  This leaves a window where
something else can set FSCACHE_COOKIE_LOOKING_UP and
__fscache_read_or_alloc_page() can start waiting, before
->backing_objects is cleared

There is some uncertainty in this analysis, but it seems to be fit the
observations.  Adding the wake in this patch will be handled correctly
by __fscache_read_or_alloc_page(), as it checks if ->backing_objects
is empty again, after waiting.

Customer which reported the hang, also report that the hang cannot be
reproduced with this fix.

The backtrace for the blocked process looked like:

PID: 29360  TASK: ffff881ff2ac0f80  CPU: 3   COMMAND: "zsh"
 #0 [ffff881ff43efbf8] schedule at ffffffff815e56f1
 #1 [ffff881ff43efc58] bit_wait at ffffffff815e64ed
 #2 [ffff881ff43efc68] __wait_on_bit at ffffffff815e61b8
 #3 [ffff881ff43efca0] out_of_line_wait_on_bit at ffffffff815e625e
 #4 [ffff881ff43efd08] fscache_wait_for_deferred_lookup at ffffffffa04f2e8f [fscache]
 #5 [ffff881ff43efd18] __fscache_read_or_alloc_page at ffffffffa04f2ffe [fscache]
 #6 [ffff881ff43efd58] __nfs_readpage_from_fscache at ffffffffa0679668 [nfs]
 #7 [ffff881ff43efd78] nfs_readpage at ffffffffa067092b [nfs]
 #8 [ffff881ff43efda0] generic_file_read_iter at ffffffff81187a73
 #9 [ffff881ff43efe50] nfs_file_read at ffffffffa066544b [nfs]
#10 [ffff881ff43efe70] __vfs_read at ffffffff811fc756
#11 [ffff881ff43efee8] vfs_read at ffffffff811fccfa
#12 [ffff881ff43eff18] sys_read at ffffffff811fda62
#13 [ffff881ff43eff50] entry_SYSCALL_64_fastpath at ffffffff815e986e
Signed-off-by: NNeilBrown <neilb@suse.com>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>

[ Upstream commit ae3b7361dc0ee9a425bf7d77ce211f533500b39b ]

When afs_validate() is called to validate a vnode (inode), there are two
unhandled cases in the fastpath at the top of the function:

 (1) If the vnode is promised (AFS_VNODE_CB_PROMISED is set), the break
     counters match and the data has expired, then there's an implicit case
     in which the vnode needs revalidating.

     This has no consequences since the default "valid = false" set at the
     top of the function happens to do the right thing.

 (2) If the vnode is not promised and it hasn't been deleted
     (AFS_VNODE_DELETED is not set) then there's a default case we're not
     handling in which the vnode is invalid.  If the vnode is invalid, we
     need to bring cb_s_break and cb_v_break up to date before we refetch
     the status.

     As a consequence, once the server loses track of the client
     (ie. sufficient time has passed since we last sent it an operation),
     it will send us a CB.InitCallBackState* operation when we next try to
     talk to it.  This calls afs_init_callback_state() which increments
     afs_server::cb_s_break, but this then doesn't propagate to the
     afs_vnode record.

     The result being that every afs_validate() call thereafter sends a
     status fetch operation to the server.

Clarify and fix this by:

 (A) Setting valid in all the branches rather than initialising it at the
     top so that the compiler catches where we've missed.

 (B) Restructuring the logic in the 'promised' branch so that we set valid
     to false if the callback is due to expire (or has expired) and so that
     the final case is that the vnode is still valid.

 (C) Adding an else-statement that ups cb_s_break and cb_v_break if the
     promised and deleted cases don't match.

Fixes: c435ee34 ("afs: Overhaul the callback handling")
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NSasha Levin <sashal@kernel.org>

[ Upstream commit 89d328f637b9904b6d4c9af73c8a608b8dd4d6f8 ]

The actual number of bytes stored in a PRZ is smaller than the
bytes requested by platform data, since there is a header on each
PRZ. Additionally, if ECC is enabled, there are trailing bytes used
as well. Normally this mismatch doesn't matter since PRZs are circular
buffers and the leading "overflow" bytes are just thrown away. However, in
the case of a compressed record, this rather badly corrupts the results.

This corruption was visible with "ramoops.mem_size=204800 ramoops.ecc=1".
Any stored crashes would not be uncompressable (producing a pstorefs
"dmesg-*.enc.z" file), and triggering errors at boot:

  [    2.790759] pstore: crypto_comp_decompress failed, ret = -22!

Backporting this depends on commit 70ad35db ("pstore: Convert console
write to use ->write_buf")
Reported-by: NJoel Fernandes <joel@joelfernandes.org>
Fixes: b0aad7a9 ("pstore: Add compression support to pstore")
Signed-off-by: NKees Cook <keescook@chromium.org>
Reviewed-by: NJoel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>

[ Upstream commit 975ef94a0284648fb0137bd5e949b18cef604e33 ]

kfree() is incorrectly used to release the pages allocated by
__get_free_page() and __get_free_pages(). Use the matching deallocators
i.e., free_page() and free_pages(), respectively.
Signed-off-by: NPan Bian <bianpan2016@163.com>
Reviewed-by: NStefano Stabellini <sstabellini@kernel.org>
Signed-off-by: NJuergen Gross <jgross@suse.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>

[ Upstream commit 123664101aa2156d05251704fc63f9bcbf77741a ]

This reverts commit b3cf8528.

That commit unintentionally broke Xen balloon memory hotplug with
"hotplug_unpopulated" set to 1. As long as "System RAM" resource
got assigned under a new "Unusable memory" resource in IO/Mem tree
any attempt to online this memory would fail due to general kernel
restrictions on having "System RAM" resources as 1st level only.

The original issue that commit has tried to workaround fa564ad9
("x86/PCI: Enable a 64bit BAR on AMD Family 15h (Models 00-1f, 30-3f,
60-7f)") also got amended by the following 03a55173 ("x86/PCI: Move
and shrink AMD 64-bit window to avoid conflict") which made the
original fix to Xen ballooning unnecessary.
Signed-off-by: NIgor Druzhinin <igor.druzhinin@citrix.com>
Reviewed-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: NJuergen Gross <jgross@suse.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>

[ Upstream commit 72791ac854fea36034fa7976b748fde585008e78 ]

Add a missing header otherwise compiler warns about missed prototype:

drivers/xen/xlate_mmu.c:183:5: warning: no previous prototype for 'xen_xlate_unmap_gfn_range?' [-Wmissing-prototypes]
  int xen_xlate_unmap_gfn_range(struct vm_area_struct *vma,
      ^~~~~~~~~~~~~~~~~~~~~~~~~
Signed-off-by: NSrikanth Boddepalli <boddepalli.srikanth@gmail.com>
Reviewed-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: NJoey Pabalinas <joeypabalinas@gmail.com>
Signed-off-by: NJuergen Gross <jgross@suse.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>

[ Upstream commit 300625620314194d9e6d4f6dda71f2dc9cf62d9f ]

v1: over-sample data to increase the stability with some specific monitors
v2: refine to avoid infinite loop
v3: remove un-necessary "volatile" declaration

[airlied: fix two checkpatch warnings]
Signed-off-by: NY.C. Chen <yc_chen@aspeedtech.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1542858988-1127-1-git-send-email-yc_chen@aspeedtech.comSigned-off-by: NSasha Levin <sashal@kernel.org>

[ Upstream commit ad97d9de45835b6a0f71983b0ae0cffd7306730a ]

Driver shouldn't try to access any GFX registers until RLC is idle.
During the test, it took 12 seconds for RLC to clear the BUSY bit
in RLC_GPM_STAT register which is un-acceptable for driver.
As per RLC engineer, it would take RLC Ucode less than 10,000 GFXCLK
cycles to finish its critical section. In a lowest 300M enginer clock
setting(default from vbios), 50 us delay is enough.

This commit fix the hang when RLC introduce the work around for XGMI
which requires more cycles to setup more registers than normal
Signed-off-by: Nshaoyunl <shaoyun.liu@amd.com>
Acked-by: NFelix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>

[ Upstream commit c758940158bf29fe14e9d0f89d5848f227b48134 ]

The net device ndev is freed via free_netdev when failing to register
the device. The control flow then jumps to the error handling code
block. ndev is used and freed again. Resulting in a use-after-free bug.
Signed-off-by: NPan Bian <bianpan2016@163.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NSasha Levin <sashal@kernel.org>

[ Upstream commit a8bf879af7b1999eba36303ce9cc60e0e7dd816c ]

Add the two 1000BaseLX enum values to the X550's check for 1Gbps modules,
allowing the core driver code to establish a link over this SFP type.

This is done by the out-of-tree driver but the fix wasn't in mainline.

Fixes: e23f3336 ("ixgbe: Fix 1G and 10G link stability for X550EM_x SFP+”)
Fixes: 6a14ee0c ("ixgbe: Add X550 support function pointers")
Signed-off-by: NJosh Elsasser <jelsasser@appneta.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>

[ Upstream commit e4c39f7926b4de355f7df75651d75003806aae09 ]

This patch fixes the variable 'phy_word' may be used uninitialized.
Signed-off-by: NYunjian Wang <wangyunjian@huawei.com>
Tested-by: NAaron Brown <aaron.f.brown@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>

[ Upstream commit 9a24ce5b66f9c8190d63b15f4473600db4935f1f ]

[Description]

In a heavily loaded system where the system pagecache is nearing memory
limits and fscache is enabled, pages can be leaked by fscache while trying
read pages from cachefiles backend.  This can happen because two
applications can be reading same page from a single mount, two threads can
be trying to read the backing page at same time.  This results in one of
the threads finding that a page for the backing file or netfs file is
already in the radix tree.  During the error handling cachefiles does not
clean up the reference on backing page, leading to page leak.

[Fix]
The fix is straightforward, to decrement the reference when error is
encountered.

  [dhowells: Note that I've removed the clearance and put of newpage as
   they aren't attested in the commit message and don't appear to actually
   achieve anything since a new page is only allocated is newpage!=NULL and
   any residual new page is cleared before returning.]

[Testing]
I have tested the fix using following method for 12+ hrs.

1) mkdir -p /mnt/nfs ; mount -o vers=3,fsc <server_ip>:/export /mnt/nfs
2) create 10000 files of 2.8MB in a NFS mount.
3) start a thread to simulate heavy VM presssure
   (while true ; do echo 3 > /proc/sys/vm/drop_caches ; sleep 1 ; done)&
4) start multiple parallel reader for data set at same time
   find /mnt/nfs -type f | xargs -P 80 cat > /dev/null &
   find /mnt/nfs -type f | xargs -P 80 cat > /dev/null &
   find /mnt/nfs -type f | xargs -P 80 cat > /dev/null &
   ..
   ..
   find /mnt/nfs -type f | xargs -P 80 cat > /dev/null &
   find /mnt/nfs -type f | xargs -P 80 cat > /dev/null &
5) finally check using cat /proc/fs/fscache/stats | grep -i pages ;
   free -h , cat /proc/meminfo and page-types -r -b lru
   to ensure all pages are freed.
Reviewed-by: NDaniel Axtens <dja@axtens.net>
Signed-off-by: NShantanu Goel <sgoel01@yahoo.com>
Signed-off-by: NKiran Kumar Modukuri <kiran.modukuri@gmail.com>
[dja: forward ported to current upstream]
Signed-off-by: NDaniel Axtens <dja@axtens.net>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>

[ Upstream commit 3f2b7b9035107d6096ea438ea3d97dcf0481b6d2 ]

The code in fscache_retrieval_complete is using atomic_sub followed by an
atomic_read:

        atomic_sub(n_pages, &op->n_pages);
        if (atomic_read(&op->n_pages) <= 0)
                fscache_op_complete(&op->op, true);

This causes two threads doing a decrement of n_pages to race with each
other seeing the op->refcount 0 at same time - and they end up calling
fscache_op_complete() in both the threads leading to an assertion failure.

Fix this by using atomic_sub_return_relaxed() instead of two calls.  Note
that I'm using 'relaxed' rather than, say, 'release' as there aren't
multiple variables that appear to need ordering across the release.

The oops looks something like:

FS-Cache: Assertion failed
FS-Cache: 0 > 0 is false
...
kernel BUG at /usr/src/linux-4.4.0/fs/fscache/operation.c:449!
...
Workqueue: fscache_operation fscache_op_work_func [fscache]
...
RIP: 0010:[<ffffffffc037eacd>] fscache_op_complete+0x10d/0x180 [fscache]
...
Call Trace:
 [<ffffffffc1464cf9>] cachefiles_read_copier+0x3a9/0x410 [cachefiles]
 [<ffffffffc037e272>] fscache_op_work_func+0x22/0x50 [fscache]
 [<ffffffff81096da0>] process_one_work+0x150/0x3f0
 [<ffffffff8109751a>] worker_thread+0x11a/0x470
 [<ffffffff81808e59>] ? __schedule+0x359/0x980
 [<ffffffff81097400>] ? rescuer_thread+0x310/0x310
 [<ffffffff8109cdd6>] kthread+0xd6/0xf0
 [<ffffffff8109cd00>] ? kthread_park+0x60/0x60
 [<ffffffff8180d0cf>] ret_from_fork+0x3f/0x70
 [<ffffffff8109cd00>] ? kthread_park+0x60/0x60

This seen this in 4.4.x kernels and the same bug affects fscache in latest
upstreams kernels.

Fixes: 1bb4b7f9 ("FS-Cache: The retrieval remaining-pages counter needs to be atomic_t")
Signed-off-by: NKiran Kumar Modukuri <kiran.modukuri@gmail.com>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>