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Bfq v8 v4.11 #1

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@ghost ghost commented Jul 31, 2017

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tndave and others added 30 commits April 21, 2017 15:45
Reducing real_num_tx_queues needs to be in sync with skb queue_mapping
otherwise skbs with queue_mapping greater than real_num_tx_queues
can be sent to the underlying driver and can result in kernel panic.

One such event is running netconsole and enabling VF on the same
device. Or running netconsole and changing number of tx queues via
ethtool on same device.

e.g.
Unable to handle kernel NULL pointer dereference
tsk->{mm,active_mm}->context = 0000000000001525
tsk->{mm,active_mm}->pgd = fff800130ff9a000
              \|/ ____ \|/
              "@'/ .. \`@"
              /_| \__/ |_\
                 \__U_/
kworker/48:1(475): Oops [#1]
CPU: 48 PID: 475 Comm: kworker/48:1 Tainted: G           OE
4.11.0-rc3-davem-net+ #7
Workqueue: events queue_process
task: fff80013113299c0 task.stack: fff800131132c000
TSTATE: 0000004480e01600 TPC: 00000000103f9e3c TNPC: 00000000103f9e40 Y:
00000000    Tainted: G           OE
TPC: <ixgbe_xmit_frame_ring+0x7c/0x6c0 [ixgbe]>
g0: 0000000000000000 g1: 0000000000003fff g2: 0000000000000000 g3:
0000000000000001
g4: fff80013113299c0 g5: fff8001fa6808000 g6: fff800131132c000 g7:
00000000000000c0
o0: fff8001fa760c460 o1: fff8001311329a50 o2: fff8001fa7607504 o3:
0000000000000003
o4: fff8001f96e63a40 o5: fff8001311d77ec0 sp: fff800131132f0e1 ret_pc:
000000000049ed94
RPC: <set_next_entity+0x34/0xb80>
l0: 0000000000000000 l1: 0000000000000800 l2: 0000000000000000 l3:
0000000000000000
l4: 000b2aa30e34b10d l5: 0000000000000000 l6: 0000000000000000 l7:
fff8001fa7605028
i0: fff80013111a8a00 i1: fff80013155a0780 i2: 0000000000000000 i3:
0000000000000000
i4: 0000000000000000 i5: 0000000000100000 i6: fff800131132f1a1 i7:
00000000103fa4b0
I7: <ixgbe_xmit_frame+0x30/0xa0 [ixgbe]>
Call Trace:
 [00000000103fa4b0] ixgbe_xmit_frame+0x30/0xa0 [ixgbe]
 [0000000000998c74] netpoll_start_xmit+0xf4/0x200
 [0000000000998e10] queue_process+0x90/0x160
 [0000000000485fa8] process_one_work+0x188/0x480
 [0000000000486410] worker_thread+0x170/0x4c0
 [000000000048c6b8] kthread+0xd8/0x120
 [0000000000406064] ret_from_fork+0x1c/0x2c
 [0000000000000000]           (null)
Disabling lock debugging due to kernel taint
Caller[00000000103fa4b0]: ixgbe_xmit_frame+0x30/0xa0 [ixgbe]
Caller[0000000000998c74]: netpoll_start_xmit+0xf4/0x200
Caller[0000000000998e10]: queue_process+0x90/0x160
Caller[0000000000485fa8]: process_one_work+0x188/0x480
Caller[0000000000486410]: worker_thread+0x170/0x4c0
Caller[000000000048c6b8]: kthread+0xd8/0x120
Caller[0000000000406064]: ret_from_fork+0x1c/0x2c
Caller[0000000000000000]:           (null)

Signed-off-by: Tushar Dave <tushar.n.dave@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull networking fixes from David Miller:

 1) Don't race in IPSEC dumps, from Yuejie Shi.

 2) Verify lengths properly in IPSEC reqeusts, from Herbert Xu.

 3) Fix out of bounds access in ipv6 segment routing code, from David
    Lebrun.

 4) Don't write into the header of cloned SKBs in smsc95xx driver, from
    James Hughes.

 5) Several other drivers have this bug too, fix them. From Eric
    Dumazet.

 6) Fix access to uninitialized data in TC action cookie code, from
    Wolfgang Bumiller.

 7) Fix double free in IPV6 segment routing, again from David Lebrun.

 8) Don't let userspace set the RTF_PCPU flag, oops. From David Ahern.

 9) Fix use after free in qrtr code, from Dan Carpenter.

10) Don't double-destroy devices in ip6mr code, from Nikolay
    Aleksandrov.

11) Don't pass out-of-range TX queue indices into drivers, from Tushar
    Dave.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (30 commits)
  netpoll: Check for skb->queue_mapping
  ip6mr: fix notification device destruction
  bpf, doc: update bpf maintainers entry
  net: qrtr: potential use after free in qrtr_sendmsg()
  bpf: Fix values type used in test_maps
  net: ipv6: RTF_PCPU should not be settable from userspace
  gso: Validate assumption of frag_list segementation
  kaweth: use skb_cow_head() to deal with cloned skbs
  ch9200: use skb_cow_head() to deal with cloned skbs
  lan78xx: use skb_cow_head() to deal with cloned skbs
  sr9700: use skb_cow_head() to deal with cloned skbs
  cx82310_eth: use skb_cow_head() to deal with cloned skbs
  smsc75xx: use skb_cow_head() to deal with cloned skbs
  ipv6: sr: fix double free of skb after handling invalid SRH
  MAINTAINERS: Add "B:" field for networking.
  net sched actions: allocate act cookie early
  qed: Fix issue in populating the PFC config paramters.
  qed: Fix possible system hang in the dcbnl-getdcbx() path.
  qed: Fix sending an invalid PFC error mask to MFW.
  qed: Fix possible error in populating max_tc field.
  ...
Pull nfsd bugfix from Bruce Fields:
 "Fix a 4.11 regression that triggers a BUG() on an attempt to use an
  unsupported NFSv4 compound op"

* tag 'nfsd-4.11-2' of git://linux-nfs.org/~bfields/linux:
  nfsd: fix oops on unsupported operation
If FW is stuck in initializing state we will skip the driver load, but
current error handling flow doesn't clean previously allocated command
interface resources.

Fixes: e329724 ('net/mlx5_core: Wait for FW readiness on startup')
Signed-off-by: Mohamad Haj Yahia <mohamad@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
On ConnectX5 the wqe inline mode is "none" and hence the FW
reports MLX5_CAP_INLINE_MODE_NOT_REQUIRED.

Fix our devlink callbacks to deal with that on get and set.

Also fix the tc flow parsing code not to fail anything when
inline isn't required.

Fixes: bffaa91 ('net/mlx5: E-Switch, Add control for inline mode')
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Reviewed-by: Roi Dayan <roid@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Otherwise the code that fills the ipv4 encapsulation headers could be writing
beyond the allocated headers buffer.

Fixes: a54e20b ('net/mlx5e: Add basic TC tunnel set action for SRIOV offloads')
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Reviewed-by: Roi Dayan <roid@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Otherwise the code that fills the ipv6 encapsulation headers could be writing
beyond the allocated headers buffer.

Fixes: ce99f6b ('net/mlx5e: Support SRIOV TC encapsulation offloads for IPv6 tunnels')
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Reviewed-by: Roi Dayan <roid@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
When UAR is released, we deallocate the device resource, but
don't unmmap the UAR mapping memory.
Fix the leak by unmapping this memory.

Fixes: a6d51b6 ('net/mlx5: Introduce blue flame register allocator)
Signed-off-by: Maor Gottlieb <maorg@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
RX packet headers are meant to be contained in SKB linear part,
and chose a threshold of 128.
It turns out this is not enough, i.e. for IPv6 packet over VxLAN.
In this case, UDP/IPv4 needs 42 bytes, GENEVE header is 8 bytes,
and 86 bytes for TCP/IPv6. In total 136 bytes that is more than
current 128 bytes. In this case expand header flow is reached.
The warning in skb_try_coalesce() caused by a wrong truesize
was already fixed here:
commit 158f323 ("net: adjust skb->truesize in pskb_expand_head()").
Still, we prefer to totally avoid the expand header flow for performance reasons.
Tested regular TCP_STREAM with iperf for 1 and 8 streams, no degradation was found.

Fixes: 461017c ("net/mlx5e: Support RX multi-packet WQE (Striding RQ)")
Signed-off-by: Eugenia Emantayev <eugenia@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Handler for ETHTOOL_GRXCLSRLALL must set info->data to the size
of the table, regardless of the amount of entries in it.
Existing code does not do that, and this breaks all usage of ethtool -N
or -n without explicit location, with this error:
rmgr: Invalid RX class rules table size: Success

Set info->data to the table size.

Tested:
ethtool -n ens8
ethtool -N ens8 flow-type ip4 src-ip 1.1.1.1 dst-ip 2.2.2.2 action 1
ethtool -N ens8 flow-type ip4 src-ip 1.1.1.1 dst-ip 2.2.2.2 action 1 loc 55
ethtool -n ens8
ethtool -N ens8 delete 1023
ethtool -N ens8 delete 55

Fixes: f913a72 ("net/mlx5e: Add support to get ethtool flow rules")
Signed-off-by: Ilan Tayari <ilant@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
…inux/kernel/git/tip/tip

Pull irq fix from Thomas Gleixner:
 "The (hopefully) final fix for the irq affinity spreading logic"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  genirq/affinity: Fix calculating vectors to assign
…inux/kernel/git/tip/tip

Pull RAS fix from Thomas Gleixner:
 "The MCE atomic notifier callchain invokes callbacks which might sleep.

  Convert it to a blocking notifier and prevent calls from atomic
  context"

* 'ras-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mce: Make the MCE notifier a blocking one
Pull UBI/UBIFS fixes from Richard Weinberger:
 "This contains fixes for issues in both UBI and UBIFS:

   - more O_TMPFILE fallout

   - RENAME_WHITEOUT regression due to a mis-merge

   - memory leak in ubifs_mknod()

   - power-cut problem in UBI's update volume feature"

* tag 'upstream-4.11-rc7' of git://git.infradead.org/linux-ubifs:
  ubifs: Fix O_TMPFILE corner case in ubifs_link()
  ubifs: Fix RENAME_WHITEOUT support
  ubifs: Fix debug messages for an invalid filename in ubifs_dump_inode
  ubifs: Fix debug messages for an invalid filename in ubifs_dump_node
  ubifs: Remove filename from debug messages in ubifs_readdir
  ubifs: Fix memory leak in error path in ubifs_mknod
  ubi/upd: Always flush after prepared for an update
This lets us enable KPROBE_EVENTS.

Signed-off-by: David S. Miller <davem@davemloft.net>
Hook up statx.

Ignore pkeys system calls, we don't have protection keeys
on SPARC.

Signed-off-by: David S. Miller <davem@davemloft.net>
We have observed a sudden spike in rx/tx_packets and rx/tx_bytes
reported under /proc/net/dev.  There is a race in mlx5e_update_stats()
and some of the get-stats functions (the one that we hit is the
mlx5e_get_stats() which is called by ndo_get_stats64()).

In particular, the very first thing mlx5e_update_sw_counters()
does is 'memset(s, 0, sizeof(*s))'.  For example, if mlx5e_get_stats()
is unlucky at one point, rx_bytes and rx_packets could be 0.  One second
later, a normal (and much bigger than 0) value will be reported.

This patch is to use a 'struct mlx5e_sw_stats temp' to avoid
a direct memset zero on priv->stats.sw.

mlx5e_update_vport_counters() has a similar race.  Hence, addressed
together.  However, memset zero is removed instead because
it is not needed.

I am lucky enough to catch this 0-reset in rx multicast:
eth0: 41457665   76804   70    0    0    70          0     47085 15586634   87502    3    0    0     0       3          0
eth0: 41459860   76815   70    0    0    70          0     47094 15588376   87516    3    0    0     0       3          0
eth0: 41460577   76822   70    0    0    70          0         0 15589083   87521    3    0    0     0       3          0
eth0: 41463293   76838   70    0    0    70          0     47108 15595872   87538    3    0    0     0       3          0
eth0: 41463379   76839   70    0    0    70          0     47116 15596138   87539    3    0    0     0       3          0

v2: Remove memset zero from mlx5e_update_vport_counters()
v1: Use temp and memcpy

Fixes: 9218b44 ("net/mlx5e: Statistics handling refactoring")
Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Suggested-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We dereference "skb" to get "skb->len" so we should probably do that
step before freeing the skb.

Fixes: eea221c ("tc35815 driver update (take 2)")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
David reported that doing the following:

    ip li add red type vrf table 10
    ip link set dev eth1 vrf red
    ip addr add 127.0.0.1/8 dev red
    ip link set dev eth1 up
    ip li set red up
    ping -c1 -w1 -I red 127.0.0.1
    ip li del red

when either policy routing IP rules are present or the local table
lookup ip rule is before the l3mdev lookup results in a hang with
these messages:

    unregister_netdevice: waiting for red to become free. Usage count = 1

The problem is caused by caching the dst used for sending the packet
out of the specified interface on a local route with a different
nexthop interface. Thus the dst could stay around until the route in
the table the lookup was done is deleted which may be never.

Address the problem by not forcing output device to be the l3mdev in
the flow's output interface if the lookup didn't use the l3mdev. This
then results in the dst using the right device according to the route.

Changes in v2:
 - make the dev_out passed in by __ip_route_output_key_hash correct
   instead of checking the nh dev if FLOWI_FLAG_SKIP_NH_OIF is set as
   suggested by David.

Fixes: 5f02ce2 ("net: l3mdev: Allow the l3mdev to be a loopback")
Reported-by: David Ahern <dsa@cumulusnetworks.com>
Suggested-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: Robert Shearman <rshearma@brocade.com>
Acked-by: David Ahern <dsa@cumulusnetworks.com>
Tested-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
While this may appear as a humdrum one line change, it's actually quite
important. An sk_buff stores data in three places:

1. A linear chunk of allocated memory in skb->data. This is the easiest
   one to work with, but it precludes using scatterdata since the memory
   must be linear.
2. The array skb_shinfo(skb)->frags, which is of maximum length
   MAX_SKB_FRAGS. This is nice for scattergather, since these fragments
   can point to different pages.
3. skb_shinfo(skb)->frag_list, which is a pointer to another sk_buff,
   which in turn can have data in either (1) or (2).

The first two are rather easy to deal with, since they're of a fixed
maximum length, while the third one is not, since there can be
potentially limitless chains of fragments. Fortunately dealing with
frag_list is opt-in for drivers, so drivers don't actually have to deal
with this mess. For whatever reason, macsec decided it wanted pain, and
so it explicitly specified NETIF_F_FRAGLIST.

Because dealing with (1), (2), and (3) is insane, most users of sk_buff
doing any sort of crypto or paging operation calls a convenient function
called skb_to_sgvec (which happens to be recursive if (3) is in use!).
This takes a sk_buff as input, and writes into its output pointer an
array of scattergather list items. Sometimes people like to declare a
fixed size scattergather list on the stack; othertimes people like to
allocate a fixed size scattergather list on the heap. However, if you're
doing it in a fixed-size fashion, you really shouldn't be using
NETIF_F_FRAGLIST too (unless you're also ensuring the sk_buff and its
frag_list children arent't shared and then you check the number of
fragments in total required.)

Macsec specifically does this:

        size += sizeof(struct scatterlist) * (MAX_SKB_FRAGS + 1);
        tmp = kmalloc(size, GFP_ATOMIC);
        *sg = (struct scatterlist *)(tmp + sg_offset);
	...
        sg_init_table(sg, MAX_SKB_FRAGS + 1);
        skb_to_sgvec(skb, sg, 0, skb->len);

Specifying MAX_SKB_FRAGS + 1 is the right answer usually, but not if you're
using NETIF_F_FRAGLIST, in which case the call to skb_to_sgvec will
overflow the heap, and disaster ensues.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: stable@vger.kernel.org
Cc: security@kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
Otherwise, UDP checksum offloads could corrupt ESP packets by attempting
to calculate UDP checksum when this inner UDP packet is already protected
by IPsec.

One way to reproduce this bug is to have a VM with virtio_net driver (UFO
set to ON in the guest VM); and then encapsulate all guest's Ethernet
frames in Geneve; and then further encrypt Geneve with IPsec.  In this
case following symptoms are observed:
1. If using ixgbe NIC, then it will complain with following error message:
   ixgbe 0000:01:00.1: partial checksum but l4 proto=32!
2. Receiving IPsec stack will drop all the corrupted ESP packets and
   increase XfrmInStateProtoError counter in /proc/net/xfrm_stat.
3. iperf UDP test from the VM with packet sizes above MTU will not work at
   all.
4. iperf TCP test from the VM will get ridiculously low performance because.

Signed-off-by: Ansis Atteka <aatteka@ovn.org>
Co-authored-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If skb_put_padto() fails then it frees the skb.  I shifted that code
up a bit to make my error handling a little simpler.

Fixes: a0d2f20 ("Renesas Ethernet AVB PTP clock driver")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When arp_notify is set to 1 for either a specific interface or for 'all'
interfaces, gratuitous arp requests are sent. Since ndisc_notify is the
ipv6 equivalent to arp_notify, it should follow the same semantics.
Commit 4a6e3c5 ("net: ipv6: send unsolicited NA on admin up") sends
the NA on admin up. The final piece is checking devconf_all->ndisc_notify
in addition to the per device setting. Add it.

Fixes: 5cb0443 ("ipv6: add knob to send unsolicited ND on link-layer address change")
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
…ux/kernel/git/saeed/linux

Saeed Mahameed says:

====================
Mellanox, mlx5 fixes 2017-04-22

This series contains some mlx5 fixes for net.

For your convenience, the series doesn't introduce any conflict with
the ongoing net-next pull request.

Please pull and let me know if there's any problem.

For -stable:
("net/mlx5: E-Switch, Correctly deal with inline mode on ConnectX-5") kernels >= 4.10
("net/mlx5e: Fix ETHTOOL_GRXCLSRLALL handling") kernels >= 4.8
("net/mlx5e: Fix small packet threshold")       kernels >= 4.7
("net/mlx5: Fix driver load bad flow when having fw initializing timeout") kernels >= 4.4
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
…ream-linus

Pull MIPS fixes from Ralf Baechle:
 "Another round of 4.11 for the MIPS architecture. This time around it's
  mostly arch but little platforms-specific code.

   - PCI: Register controllers in the right order to aoid a PCI error
   - KGDB: Use kernel context for sleeping threads
   - smp-cps: Fix potentially uninitialised value of core
   - KASLR: Fix build
   - ELF: Fix BUG() warning in arch_check_elf
   - Fix modversioning of _mcount symbol
   - fix out-of-tree defconfig target builds
   - cevt-r4k: Fix out-of-bounds array access
   - perf: fix deadlock
   - Malta: Fix i8259 irqchip setup"

* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus:
  MIPS: PCI: add controllers before the specified head
  MIPS: KGDB: Use kernel context for sleeping threads
  MIPS: smp-cps: Fix potentially uninitialised value of core
  MIPS: KASLR: Add missing header files
  MIPS: Avoid BUG warning in arch_check_elf
  MIPS: Fix modversioning of _mcount symbol
  MIPS: generic: fix out-of-tree defconfig target builds
  MIPS: cevt-r4k: Fix out-of-bounds array access
  MIPS: perf: fix deadlock
  MIPS: Malta: Fix i8259 irqchip setup
…it/jejb/scsi

Pull SCSI fix from James Bottomley:
 "Our final fix before the 4.12 release (hopefully).

  It's an error leg again: the fix to not bug on empty DMA transfers is
  returning the wrong code and confusing the block layer"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: return correct blkprep status code in case scsi_init_io() fails.
Since Broadcom tags are not enabled in b53 (DSA_PROTO_TAG_NONE), we need
to make sure that the IMP/CPU port is included in the forwarding
decision.

Without this change, switching between non-management ports would work,
but not between management ports and non-management ports thus breaking
the default state in which DSA switch are brought up.

Fixes: 967dd82 ("net: dsa: b53: Add support for Broadcom RoboSwitch")
Reported-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Implement the correct software reset sequence for 58xx devices by
setting all 3 reset bits and polling for the SW_RST bit to clear itself
without a given timeout. We cannot use is58xx() here because that would
also include the 7445/7278 Starfighter 2 which have their own driver
doing the reset earlier on due to the HW specific integration.

Fixes: 991a36b ("net: dsa: b53: Add support for BCM585xx/586xx/88312 integrated switch")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The 58xx devices (Northstar Plus) do actually have their CPU port wired
at port 8, it was unfortunately set to port 5 (B53_CPU_PORT_25) which is
incorrect, since that is the second possible management port.

Fixes: 991a36b ("net: dsa: b53: Add support for BCM585xx/586xx/88312 integrated switch")
Reported-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Florian Fainelli says:

====================
net: dsa: b53: BCM58xx devices fixes

This patch series contains fixes for the 58xx devices (Broadcom Northstar
Plus), which were identified thanks to the help of Eric Anholt.
====================

Tested-by: Eric Anholt <eric@anholt.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
philmmanjaro pushed a commit to philmmanjaro/linux-bfq that referenced this pull request Aug 6, 2017
commit 8046e19 upstream.

We unref the man->move fence in ttm_bo_clean_mm() and then call
ttm_bo_force_list_clean() which waits on it, except the refcount is now
zero so a warning is generated (or worse):

[149492.279301] refcount_t: increment on 0; use-after-free.
[149492.279309] ------------[ cut here ]------------
[149492.279315] WARNING: CPU: 3 PID: 18726 at lib/refcount.c:150 refcount_inc+0x2b/0x30
[149492.279315] Modules linked in: vhost_net vhost tun x86_pkg_temp_thermal crc32_pclmul ghash_clmulni_intel efivarfs amdgpu(
-) i2c_algo_bit drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm drm
[149492.279326] CPU: 3 PID: 18726 Comm: rmmod Not tainted 4.12.0-rc5-drm-next-4.13-ttmpatch+ linusw#1
[149492.279326] Hardware name: Gigabyte Technology Co., Ltd. Z97X-UD3H-BK/Z97X-UD3H-BK-CF, BIOS F6 06/17/2014
[149492.279327] task: ffff8804ddfedcc0 task.stack: ffffc90008d20000
[149492.279329] RIP: 0010:refcount_inc+0x2b/0x30
[149492.279330] RSP: 0018:ffffc90008d23c30 EFLAGS: 00010286
[149492.279331] RAX: 000000000000002b RBX: 0000000000000170 RCX: 0000000000000000
[149492.279331] RDX: 0000000000000000 RSI: ffff88051ecccbe8 RDI: ffff88051ecccbe8
[149492.279332] RBP: ffffc90008d23c30 R08: 0000000000000001 R09: 00000000000003ee
[149492.279333] R10: ffffc90008d23bb0 R11: 00000000000003ee R12: ffff88043aaac960
[149492.279333] R13: ffff8805005e28a8 R14: 0000000000000002 R15: ffff88050115e178
[149492.279334] FS:  00007fc540168700(0000) GS:ffff88051ecc0000(0000) knlGS:0000000000000000
[149492.279335] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[149492.279336] CR2: 00007fc3e8654140 CR3: 000000027ba77000 CR4: 00000000001426e0
[149492.279337] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[149492.279337] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[149492.279338] Call Trace:
[149492.279345]  ttm_bo_force_list_clean+0xb9/0x110 [ttm]
[149492.279348]  ttm_bo_clean_mm+0x7a/0xe0 [ttm]
[149492.279375]  amdgpu_ttm_fini+0xc9/0x1f0 [amdgpu]
[149492.279392]  amdgpu_bo_fini+0x12/0x40 [amdgpu]
[149492.279415]  gmc_v7_0_sw_fini+0x32/0x40 [amdgpu]
[149492.279430]  amdgpu_fini+0x2c9/0x490 [amdgpu]
[149492.279445]  amdgpu_device_fini+0x58/0x1b0 [amdgpu]
[149492.279461]  amdgpu_driver_unload_kms+0x4f/0xa0 [amdgpu]
[149492.279470]  drm_dev_unregister+0x3c/0xe0 [drm]
[149492.279485]  amdgpu_pci_remove+0x19/0x30 [amdgpu]
[149492.279487]  pci_device_remove+0x39/0xc0
[149492.279490]  device_release_driver_internal+0x155/0x210
[149492.279491]  driver_detach+0x38/0x70
[149492.279493]  bus_remove_driver+0x4c/0xa0
[149492.279494]  driver_unregister+0x2c/0x40
[149492.279496]  pci_unregister_driver+0x21/0x90
[149492.279520]  amdgpu_exit+0x15/0x406 [amdgpu]
[149492.279523]  SyS_delete_module+0x1a8/0x270
[149492.279525]  ? exit_to_usermode_loop+0x92/0xa0
[149492.279528]  entry_SYSCALL_64_fastpath+0x13/0x94
[149492.279529] RIP: 0033:0x7fc53fcb68e7
[149492.279529] RSP: 002b:00007ffcfbfaabb8 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0
[149492.279531] RAX: ffffffffffffffda RBX: 0000563117adb200 RCX: 00007fc53fcb68e7
[149492.279531] RDX: 000000000000000a RSI: 0000000000000800 RDI: 0000563117adb268
[149492.279532] RBP: 0000000000000003 R08: 0000000000000000 R09: 1999999999999999
[149492.279533] R10: 0000000000000883 R11: 0000000000000206 R12: 00007ffcfbfa9ba0
[149492.279533] R13: 0000000000000000 R14: 0000000000000000 R15: 0000563117adb200
[149492.279534] Code: 55 48 89 e5 e8 77 fe ff ff 84 c0 74 02 5d c3 80 3d 40 f2 a4 00 00 75 f5 48 c7 c7 20 3c ca 81 c6 05 30 f2 a4 00 01 e8 91 f0 d7 ff <0f> ff 5d c3 90 55 48 89 fe bf 01 00 00 00 48 89 e5 e8 9f fe ff
[149492.279557] ---[ end trace 2d4e0ffcb66a1016 ]---

Unref the fence *after* waiting for it.

v2: Set man->move to NULL after dropping the last ref (Christian König)

Fixes: aff98ba (drm/ttm: wait for eviction in ttm_bo_force_list_clean)
Signed-off-by: John Brooks <john@fastquake.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
philmmanjaro pushed a commit to philmmanjaro/linux-bfq that referenced this pull request Aug 6, 2017
commit cdea465 upstream.

A vendor with a system having more than 128 CPUs occasionally encounters
the following crash during shutdown. This is not an easily reproduceable
event, but the vendor was able to provide the following analysis of the
crash, which exhibits the same footprint each time.

crash> bt
PID: 0      TASK: ffff88017c70ce70  CPU: 5   COMMAND: "swapper/5"
 #0 [ffff88085c143ac8] machine_kexec at ffffffff81059c8b
 linusw#1 [ffff88085c143b28] __crash_kexec at ffffffff811052e2
 #2 [ffff88085c143bf8] crash_kexec at ffffffff811053d0
 #3 [ffff88085c143c10] oops_end at ffffffff8168ef88
 #4 [ffff88085c143c38] no_context at ffffffff8167ebb3
 #5 [ffff88085c143c88] __bad_area_nosemaphore at ffffffff8167ec49
 #6 [ffff88085c143cd0] bad_area_nosemaphore at ffffffff8167edb3
 #7 [ffff88085c143ce0] __do_page_fault at ffffffff81691d1e
 #8 [ffff88085c143d40] do_page_fault at ffffffff81691ec5
 #9 [ffff88085c143d70] page_fault at ffffffff8168e188
    [exception RIP: unknown or invalid address]
    RIP: ffffffffa053c800  RSP: ffff88085c143e28  RFLAGS: 00010206
    RAX: ffff88017c72bfd8  RBX: ffff88017a8dc000  RCX: ffff8810588b5ac8
    RDX: ffff8810588b5a00  RSI: ffffffffa053c800  RDI: ffff8810588b5a00
    RBP: ffff88085c143e58   R8: ffff88017c70d408   R9: ffff88017a8dc000
    R10: 0000000000000002  R11: ffff88085c143da0  R12: ffff8810588b5ac8
    R13: 0000000000000100  R14: ffffffffa053c800  R15: ffff8810588b5a00
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
    <IRQ stack>
    [exception RIP: cpuidle_enter_state+82]
    RIP: ffffffff81514192  RSP: ffff88017c72be50  RFLAGS: 00000202
    RAX: 0000001e4c3c6f16  RBX: 000000000000f8a0  RCX: 0000000000000018
    RDX: 0000000225c17d03  RSI: ffff88017c72bfd8  RDI: 0000001e4c3c6f16
    RBP: ffff88017c72be78   R8: 000000000000237e   R9: 0000000000000018
    R10: 0000000000002494  R11: 0000000000000001  R12: ffff88017c72be20
    R13: ffff88085c14f8e0  R14: 0000000000000082  R15: 0000001e4c3bb400
    ORIG_RAX: ffffffffffffff10  CS: 0010  SS: 0018

This is the corresponding stack trace

It has crashed because the area pointed with RIP extracted from timer
element is already removed during a shutdown process.

The function is smi_timeout().

And we think ffff8810588b5a00 in RDX is a parameter struct smi_info

crash> rd ffff8810588b5a00 20
ffff8810588b5a00:  ffff8810588b6000 0000000000000000   .`.X............
ffff8810588b5a10:  ffff880853264400 ffffffffa05417e0   .D&S......T.....
ffff8810588b5a20:  24a024a000000000 0000000000000000   .....$.$........
ffff8810588b5a30:  0000000000000000 0000000000000000   ................
ffff8810588b5a30:  0000000000000000 0000000000000000   ................
ffff8810588b5a40:  ffffffffa053a040 ffffffffa053a060   @.S.....`.S.....
ffff8810588b5a50:  0000000000000000 0000000100000001   ................
ffff8810588b5a60:  0000000000000000 0000000000000e00   ................
ffff8810588b5a70:  ffffffffa053a580 ffffffffa053a6e0   ..S.......S.....
ffff8810588b5a80:  ffffffffa053a4a0 ffffffffa053a250   ..S.....P.S.....
ffff8810588b5a90:  0000000500000002 0000000000000000   ................

Unfortunately the top of this area is already detroyed by someone.
But because of two reasonns we think this is struct smi_info
 1) The address included in between  ffff8810588b5a70 and ffff8810588b5a80:
  are inside of ipmi_si_intf.c  see crash> module ffff88085779d2c0

 2) We've found the area which point this.
  It is offset 0x68 of  ffff880859df4000

crash> rd  ffff880859df4000 100
ffff880859df4000:  0000000000000000 0000000000000001   ................
ffff880859df4010:  ffffffffa0535290 dead000000000200   .RS.............
ffff880859df4020:  ffff880859df4020 ffff880859df4020    @.Y.... @.Y....
ffff880859df4030:  0000000000000002 0000000000100010   ................
ffff880859df4040:  ffff880859df4040 ffff880859df4040   @@.Y....@@.Y....
ffff880859df4050:  0000000000000000 0000000000000000   ................
ffff880859df4060:  0000000000000000 ffff8810588b5a00   .........Z.X....
ffff880859df4070:  0000000000000001 ffff880859df4078   ........x@.Y....

 If we regards it as struct ipmi_smi in shutdown process
 it looks consistent.

The remedy for this apparent race is affixed below.

Signed-off-by: Tony Camuso <tcamuso@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This was first introduced in 7ea0ed2 ipmi: Make the
message handler easier to use for SMI interfaces
where some code was moved outside of the rcu_read_lock()
and the lock was not added.

Signed-off-by: Corey Minyard <cminyard@mvista.com>
philmmanjaro pushed a commit to philmmanjaro/linux-bfq that referenced this pull request Aug 6, 2017
commit d1aa245 upstream.

generic/361 reports below warning, this is because: once, there is
someone entering into critical region of sbi.cp_lock, if write_end_io.
f2fs_stop_checkpoint is invoked from an triggered IRQ, we will encounter
deadlock.

So this patch changes to use spin_{,un}lock_irq{save,restore} to create
critical region without IRQ enabled to avoid potential deadlock.

 irq event stamp: 83391573
 loop: Write error at byte offset 438729728, length 1024.
 hardirqs last  enabled at (83391573): [<c1809752>] restore_all+0xf/0x65
 hardirqs last disabled at (83391572): [<c1809eac>] reschedule_interrupt+0x30/0x3c
 loop: Write error at byte offset 438860288, length 1536.
 softirqs last  enabled at (83389244): [<c180cc4e>] __do_softirq+0x1ae/0x476
 softirqs last disabled at (83389237): [<c101ca7c>] do_softirq_own_stack+0x2c/0x40
 loop: Write error at byte offset 438990848, length 2048.
 ================================
 WARNING: inconsistent lock state
 4.12.0-rc2+ #30 Tainted: G           O
 --------------------------------
 inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W} usage.
 xfs_io/7959 [HC1[1]:SC0[0]:HE0:SE1] takes:
  (&(&sbi->cp_lock)->rlock){?.+...}, at: [<f96f96cc>] f2fs_stop_checkpoint+0x1c/0x50 [f2fs]
 {HARDIRQ-ON-W} state was registered at:
   __lock_acquire+0x527/0x7b0
   lock_acquire+0xae/0x220
   _raw_spin_lock+0x42/0x50
   do_checkpoint+0x165/0x9e0 [f2fs]
   write_checkpoint+0x33f/0x740 [f2fs]
   __f2fs_sync_fs+0x92/0x1f0 [f2fs]
   f2fs_sync_fs+0x12/0x20 [f2fs]
   sync_filesystem+0x67/0x80
   generic_shutdown_super+0x27/0x100
   kill_block_super+0x22/0x50
   kill_f2fs_super+0x3a/0x40 [f2fs]
   deactivate_locked_super+0x3d/0x70
   deactivate_super+0x40/0x60
   cleanup_mnt+0x39/0x70
   __cleanup_mnt+0x10/0x20
   task_work_run+0x69/0x80
   exit_to_usermode_loop+0x57/0x85
   do_fast_syscall_32+0x18c/0x1b0
   entry_SYSENTER_32+0x4c/0x7b
 irq event stamp: 1957420
 hardirqs last  enabled at (1957419): [<c1808f37>] _raw_spin_unlock_irq+0x27/0x50
 hardirqs last disabled at (1957420): [<c1809f9c>] call_function_single_interrupt+0x30/0x3c
 softirqs last  enabled at (1953784): [<c180cc4e>] __do_softirq+0x1ae/0x476
 softirqs last disabled at (1953773): [<c101ca7c>] do_softirq_own_stack+0x2c/0x40

 other info that might help us debug this:
  Possible unsafe locking scenario:

        CPU0
        ----
   lock(&(&sbi->cp_lock)->rlock);
   <Interrupt>
     lock(&(&sbi->cp_lock)->rlock);

  *** DEADLOCK ***

 2 locks held by xfs_io/7959:
  #0:  (sb_writers#13){.+.+.+}, at: [<c11fd7ca>] vfs_write+0x16a/0x190
  linusw#1:  (&sb->s_type->i_mutex_key#16){+.+.+.}, at: [<f96e33f5>] f2fs_file_write_iter+0x25/0x140 [f2fs]

 stack backtrace:
 CPU: 2 PID: 7959 Comm: xfs_io Tainted: G           O    4.12.0-rc2+ #30
 Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
 Call Trace:
  dump_stack+0x5f/0x92
  print_usage_bug+0x1d3/0x1dd
  ? check_usage_backwards+0xe0/0xe0
  mark_lock+0x23d/0x280
  __lock_acquire+0x699/0x7b0
  ? __this_cpu_preempt_check+0xf/0x20
  ? trace_hardirqs_off_caller+0x91/0xe0
  lock_acquire+0xae/0x220
  ? f2fs_stop_checkpoint+0x1c/0x50 [f2fs]
  _raw_spin_lock+0x42/0x50
  ? f2fs_stop_checkpoint+0x1c/0x50 [f2fs]
  f2fs_stop_checkpoint+0x1c/0x50 [f2fs]
  f2fs_write_end_io+0x147/0x150 [f2fs]
  bio_endio+0x7a/0x1e0
  blk_update_request+0xad/0x410
  blk_mq_end_request+0x16/0x60
  lo_complete_rq+0x3c/0x70
  __blk_mq_complete_request_remote+0x11/0x20
  flush_smp_call_function_queue+0x6d/0x120
  ? debug_smp_processor_id+0x12/0x20
  generic_smp_call_function_single_interrupt+0x12/0x30
  smp_call_function_single_interrupt+0x25/0x40
  call_function_single_interrupt+0x37/0x3c
 EIP: _raw_spin_unlock_irq+0x2d/0x50
 EFLAGS: 00000296 CPU: 2
 EAX: 00000001 EBX: d2ccc51c ECX: 00000001 EDX: c1aacebd
 ESI: 00000000 EDI: 00000000 EBP: c96c9d1c ESP: c96c9d18
  DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
  ? inherit_task_group.isra.98.part.99+0x6b/0xb0
  __add_to_page_cache_locked+0x1d4/0x290
  add_to_page_cache_lru+0x38/0xb0
  pagecache_get_page+0x8e/0x200
  f2fs_write_begin+0x96/0xf00 [f2fs]
  ? trace_hardirqs_on_caller+0xdd/0x1c0
  ? current_time+0x17/0x50
  ? trace_hardirqs_on+0xb/0x10
  generic_perform_write+0xa9/0x170
  __generic_file_write_iter+0x1a2/0x1f0
  ? f2fs_preallocate_blocks+0x137/0x160 [f2fs]
  f2fs_file_write_iter+0x6e/0x140 [f2fs]
  ? __lock_acquire+0x429/0x7b0
  __vfs_write+0xc1/0x140
  vfs_write+0x9b/0x190
  SyS_pwrite64+0x63/0xa0
  do_fast_syscall_32+0xa1/0x1b0
  entry_SYSENTER_32+0x4c/0x7b
 EIP: 0xb7786c61
 EFLAGS: 00000293 CPU: 2
 EAX: ffffffda EBX: 00000003 ECX: 08416000 EDX: 00001000
 ESI: 18b24000 EDI: 00000000 EBP: 00000003 ESP: bf9b36b0
  DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 007b

Fixes: aaec2b1 ("f2fs: introduce cp_lock to protect updating of ckpt_flags")
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
philmmanjaro pushed a commit to philmmanjaro/linux-bfq that referenced this pull request Aug 6, 2017
commit 340d394 upstream.

The driver checks port->exists twice in i8042_interrupt(), first when
trying to assign temporary "serio" variable, and second time when deciding
whether it should call serio_interrupt(). The value of port->exists may
change between the 2 checks, and we may end up calling serio_interrupt()
with a NULL pointer:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000050
IP: [<ffffffff8150feaf>] _spin_lock_irqsave+0x1f/0x40
PGD 0
Oops: 0002 [linusw#1] SMP
last sysfs file:
CPU 0
Modules linked in:

Pid: 1, comm: swapper Not tainted 2.6.32-358.el6.x86_64 linusw#1 QEMU Standard PC (i440FX + PIIX, 1996)
RIP: 0010:[<ffffffff8150feaf>]  [<ffffffff8150feaf>] _spin_lock_irqsave+0x1f/0x40
RSP: 0018:ffff880028203cc0  EFLAGS: 00010082
RAX: 0000000000010000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000282 RSI: 0000000000000098 RDI: 0000000000000050
RBP: ffff880028203cc0 R08: ffff88013e79c000 R09: ffff880028203ee0
R10: 0000000000000298 R11: 0000000000000282 R12: 0000000000000050
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000098
FS:  0000000000000000(0000) GS:ffff880028200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0018 ES: 0018 CR0: 000000008005003b
CR2: 0000000000000050 CR3: 0000000001a85000 CR4: 00000000001407f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process swapper (pid: 1, threadinfo ffff88013e79c000, task ffff88013e79b500)
Stack:
ffff880028203d00 ffffffff813de186 ffffffffffffff02 0000000000000000
<d> 0000000000000000 0000000000000000 0000000000000000 0000000000000098
<d> ffff880028203d70 ffffffff813e0162 ffff880028203d20 ffffffff8103b8ac
Call Trace:
<IRQ>
 [<ffffffff813de186>] serio_interrupt+0x36/0xa0
[<ffffffff813e0162>] i8042_interrupt+0x132/0x3a0
[<ffffffff8103b8ac>] ? kvm_clock_read+0x1c/0x20
[<ffffffff8103b8b9>] ? kvm_clock_get_cycles+0x9/0x10
[<ffffffff810e1640>] handle_IRQ_event+0x60/0x170
[<ffffffff8103b154>] ? kvm_guest_apic_eoi_write+0x44/0x50
[<ffffffff810e3d8e>] handle_edge_irq+0xde/0x180
[<ffffffff8100de89>] handle_irq+0x49/0xa0
[<ffffffff81516c8c>] do_IRQ+0x6c/0xf0
[<ffffffff8100b9d3>] ret_from_intr+0x0/0x11
[<ffffffff81076f63>] ? __do_softirq+0x73/0x1e0
[<ffffffff8109b75b>] ? hrtimer_interrupt+0x14b/0x260
[<ffffffff8100c1cc>] ? call_softirq+0x1c/0x30
[<ffffffff8100de05>] ? do_softirq+0x65/0xa0
[<ffffffff81076d95>] ? irq_exit+0x85/0x90
[<ffffffff81516d80>] ? smp_apic_timer_interrupt+0x70/0x9b
[<ffffffff8100bb93>] ? apic_timer_interrupt+0x13/0x20

To avoid the issue let's change the second check to test whether serio is
NULL or not.

Also, let's take i8042_lock in i8042_start() and i8042_stop() instead of
trying to be overly smart and using memory barriers.

Signed-off-by: Chen Hong <chenhong3@huawei.com>
[dtor: take lock in i8042_start()/i8042_stop()]
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
philmmanjaro pushed a commit to philmmanjaro/linux-bfq that referenced this pull request Aug 6, 2017
commit 0e4097c upstream.

Recent kernels trigger this warning:

 BUG: using smp_processor_id() in preemptible [00000000] code: 99-trinity/181
 caller is debug_smp_processor_id+0x17/0x19
 CPU: 0 PID: 181 Comm: 99-trinity Not tainted 4.12.0-01059-g2a42eb9 linusw#1
 Call Trace:
  dump_stack+0x82/0xb8
  check_preemption_disabled()
  debug_smp_processor_id()
  vtime_delta()
  task_cputime()
  thread_group_cputime()
  thread_group_cputime_adjusted()
  wait_consider_task()
  do_wait()
  SYSC_wait4()
  do_syscall_64()
  entry_SYSCALL64_slow_path()

As Frederic pointed out:

| Although those sched_clock_cpu() things seem to only matter when the
| sched_clock() is unstable. And that stability is a condition for nohz_full
| to work anyway. So probably sched_clock() alone would be enough.

This patch fixes it by replacing sched_clock_cpu() with sched_clock() to
avoid calling smp_processor_id() in a preemptible context.

Reported-by: Xiaolong Ye <xiaolong.ye@intel.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1499586028-7402-1-git-send-email-wanpeng.li@hotmail.com
[ Prettified the changelog. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
philmmanjaro pushed a commit to philmmanjaro/linux-bfq that referenced this pull request Aug 6, 2017
commit 1a3fc2c upstream.

There has been a report about a deadlock in the xenbus driver:

[  247.979498] ======================================================
[  247.985688] WARNING: possible circular locking dependency detected
[  247.991882] 4.12.0-rc4-00022-gc4b25c0 #575 Not tainted
[  247.997040] ------------------------------------------------------
[  248.003232] xenbus/91 is trying to acquire lock:
[  248.007875]  (&u->msgbuffer_mutex){+.+.+.}, at: [<ffff00000863e904>]
xenbus_dev_queue_reply+0x3c/0x230
[  248.017163]
[  248.017163] but task is already holding lock:
[  248.023096]  (xb_write_mutex){+.+...}, at: [<ffff00000863a940>]
xenbus_thread+0x5f0/0x798
[  248.031267]
[  248.031267] which lock already depends on the new lock.
[  248.031267]
[  248.039615]
[  248.039615] the existing dependency chain (in reverse order) is:
[  248.047176]
[  248.047176] -> linusw#1 (xb_write_mutex){+.+...}:
[  248.052943]        __lock_acquire+0x1728/0x1778
[  248.057498]        lock_acquire+0xc4/0x288
[  248.061630]        __mutex_lock+0x84/0x868
[  248.065755]        mutex_lock_nested+0x3c/0x50
[  248.070227]        xs_send+0x164/0x1f8
[  248.074015]        xenbus_dev_request_and_reply+0x6c/0x88
[  248.079427]        xenbus_file_write+0x260/0x420
[  248.084073]        __vfs_write+0x48/0x138
[  248.088113]        vfs_write+0xa8/0x1b8
[  248.091983]        SyS_write+0x54/0xb0
[  248.095768]        el0_svc_naked+0x24/0x28
[  248.099897]
[  248.099897] -> #0 (&u->msgbuffer_mutex){+.+.+.}:
[  248.106088]        print_circular_bug+0x80/0x2e0
[  248.110730]        __lock_acquire+0x1768/0x1778
[  248.115288]        lock_acquire+0xc4/0x288
[  248.119417]        __mutex_lock+0x84/0x868
[  248.123545]        mutex_lock_nested+0x3c/0x50
[  248.128016]        xenbus_dev_queue_reply+0x3c/0x230
[  248.133005]        xenbus_thread+0x788/0x798
[  248.137306]        kthread+0x110/0x140
[  248.141087]        ret_from_fork+0x10/0x40

It is rather easy to avoid by dropping xb_write_mutex before calling
xenbus_dev_queue_reply().

Fixes: fd8aa90 ("xen: optimize xenbus
driver for multiple concurrent xenstore accesses").

Reported-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Tested-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
philmmanjaro pushed a commit to philmmanjaro/linux-bfq that referenced this pull request Aug 6, 2017
commit 2fd1d2c upstream.

Andrei Vagin writes:
FYI: This bug has been reproduced on 4.11.7
> BUG: Dentry ffff895a3dd01240{i=4e7c09a,n=lo}  still in use (1) [unmount of proc proc]
> ------------[ cut here ]------------
> WARNING: CPU: 1 PID: 13588 at fs/dcache.c:1445 umount_check+0x6e/0x80
> CPU: 1 PID: 13588 Comm: kworker/1:1 Not tainted 4.11.7-200.fc25.x86_64 linusw#1
> Hardware name: CompuLab sbc-flt1/fitlet, BIOS SBCFLT_0.08.04 06/27/2015
> Workqueue: events proc_cleanup_work
> Call Trace:
>  dump_stack+0x63/0x86
>  __warn+0xcb/0xf0
>  warn_slowpath_null+0x1d/0x20
>  umount_check+0x6e/0x80
>  d_walk+0xc6/0x270
>  ? dentry_free+0x80/0x80
>  do_one_tree+0x26/0x40
>  shrink_dcache_for_umount+0x2d/0x90
>  generic_shutdown_super+0x1f/0xf0
>  kill_anon_super+0x12/0x20
>  proc_kill_sb+0x40/0x50
>  deactivate_locked_super+0x43/0x70
>  deactivate_super+0x5a/0x60
>  cleanup_mnt+0x3f/0x90
>  mntput_no_expire+0x13b/0x190
>  kern_unmount+0x3e/0x50
>  pid_ns_release_proc+0x15/0x20
>  proc_cleanup_work+0x15/0x20
>  process_one_work+0x197/0x450
>  worker_thread+0x4e/0x4a0
>  kthread+0x109/0x140
>  ? process_one_work+0x450/0x450
>  ? kthread_park+0x90/0x90
>  ret_from_fork+0x2c/0x40
> ---[ end trace e1c109611e5d0b41 ]---
> VFS: Busy inodes after unmount of proc. Self-destruct in 5 seconds.  Have a nice day...
> BUG: unable to handle kernel NULL pointer dereference at           (null)
> IP: _raw_spin_lock+0xc/0x30
> PGD 0

Fix this by taking a reference to the super block in proc_sys_prune_dcache.

The superblock reference is the core of the fix however the sysctl_inodes
list is converted to a hlist so that hlist_del_init_rcu may be used.  This
allows proc_sys_prune_dache to remove inodes the sysctl_inodes list, while
not causing problems for proc_sys_evict_inode when if it later choses to
remove the inode from the sysctl_inodes list.  Removing inodes from the
sysctl_inodes list allows proc_sys_prune_dcache to have a progress
guarantee, while still being able to drop all locks.  The fact that
head->unregistering is set in start_unregistering ensures that no more
inodes will be added to the the sysctl_inodes list.

Previously the code did a dance where it delayed calling iput until the
next entry in the list was being considered to ensure the inode remained on
the sysctl_inodes list until the next entry was walked to.  The structure
of the loop in this patch does not need that so is much easier to
understand and maintain.

Reported-by: Andrei Vagin <avagin@gmail.com>
Tested-by: Andrei Vagin <avagin@openvz.org>
Fixes: ace0c79 ("proc/sysctl: Don't grab i_lock under sysctl_lock.")
Fixes: d6cffbb ("proc/sysctl: prune stale dentries during unregistering")
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
philmmanjaro pushed a commit to philmmanjaro/linux-bfq that referenced this pull request Aug 6, 2017
[ Upstream commit f630c38 ]

When destroying a VRF device we cleanup the slaves in its ndo_uninit()
function, but that causes packets to be switched (skb->dev == vrf being
destroyed) even though we're pass the point where the VRF should be
receiving any packets while it is being dismantled. This causes a BUG_ON
to trigger if we have raw sockets (trace below).
The reason is that the inetdev of the VRF has been destroyed but we're
still sending packets up the stack with it, so let's free the slaves in
the dellink callback as David Ahern suggested.

Note that this fix doesn't prevent packets from going up when the VRF
device is admin down.

[   35.631371] ------------[ cut here ]------------
[   35.631603] kernel BUG at net/ipv4/fib_frontend.c:285!
[   35.631854] invalid opcode: 0000 [linusw#1] SMP
[   35.631977] Modules linked in:
[   35.632081] CPU: 2 PID: 22 Comm: ksoftirqd/2 Not tainted 4.12.0-rc7+ #45
[   35.632247] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140531_083030-gandalf 04/01/2014
[   35.632477] task: ffff88005ad68000 task.stack: ffff88005ad64000
[   35.632632] RIP: 0010:fib_compute_spec_dst+0xfc/0x1ee
[   35.632769] RSP: 0018:ffff88005ad67978 EFLAGS: 00010202
[   35.632910] RAX: 0000000000000001 RBX: ffff880059a7f200 RCX: 0000000000000000
[   35.633084] RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffffffff82274af0
[   35.633256] RBP: ffff88005ad679f8 R08: 000000000001ef70 R09: 0000000000000046
[   35.633430] R10: ffff88005ad679f8 R11: ffff880037731cb0 R12: 0000000000000001
[   35.633603] R13: ffff8800599e3000 R14: 0000000000000000 R15: ffff8800599cb852
[   35.634114] FS:  0000000000000000(0000) GS:ffff88005d900000(0000) knlGS:0000000000000000
[   35.634306] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   35.634456] CR2: 00007f3563227095 CR3: 000000000201d000 CR4: 00000000000406e0
[   35.634632] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   35.634865] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   35.635055] Call Trace:
[   35.635271]  ? __lock_acquire+0xf0d/0x1117
[   35.635522]  ipv4_pktinfo_prepare+0x82/0x151
[   35.635831]  raw_rcv_skb+0x17/0x3c
[   35.636062]  raw_rcv+0xe5/0xf7
[   35.636287]  raw_local_deliver+0x169/0x1d9
[   35.636534]  ip_local_deliver_finish+0x87/0x1c4
[   35.636820]  ip_local_deliver+0x63/0x7f
[   35.637058]  ip_rcv_finish+0x340/0x3a1
[   35.637295]  ip_rcv+0x314/0x34a
[   35.637525]  __netif_receive_skb_core+0x49f/0x7c5
[   35.637780]  ? lock_acquire+0x13f/0x1d7
[   35.638018]  ? lock_acquire+0x15e/0x1d7
[   35.638259]  __netif_receive_skb+0x1e/0x94
[   35.638502]  ? __netif_receive_skb+0x1e/0x94
[   35.638748]  netif_receive_skb_internal+0x74/0x300
[   35.639002]  ? dev_gro_receive+0x2ed/0x411
[   35.639246]  ? lock_is_held_type+0xc4/0xd2
[   35.639491]  napi_gro_receive+0x105/0x1a0
[   35.639736]  receive_buf+0xc32/0xc74
[   35.639965]  ? detach_buf+0x67/0x153
[   35.640201]  ? virtqueue_get_buf_ctx+0x120/0x176
[   35.640453]  virtnet_poll+0x128/0x1c5
[   35.640690]  net_rx_action+0x103/0x343
[   35.640932]  __do_softirq+0x1c7/0x4b7
[   35.641171]  run_ksoftirqd+0x23/0x5c
[   35.641403]  smpboot_thread_fn+0x24f/0x26d
[   35.641646]  ? sort_range+0x22/0x22
[   35.641878]  kthread+0x129/0x131
[   35.642104]  ? __list_add+0x31/0x31
[   35.642335]  ? __list_add+0x31/0x31
[   35.642568]  ret_from_fork+0x2a/0x40
[   35.642804] Code: 05 bd 87 a3 00 01 e8 1f ef 98 ff 4d 85 f6 48 c7 c7 f0 4a 27 82 41 0f 94 c4 31 c9 31 d2 41 0f b6 f4 e8 04 71 a1 ff 45 84 e4 74 02 <0f> 0b 0f b7 93 c4 00 00 00 4d 8b a5 80 05 00 00 48 03 93 d0 00
[   35.644342] RIP: fib_compute_spec_dst+0xfc/0x1ee RSP: ffff88005ad67978

Fixes: 193125d ("net: Introduce VRF device driver")
Reported-by: Chris Cormier <chriscormier@cumulusnetworks.com>
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
philmmanjaro pushed a commit to philmmanjaro/linux-bfq that referenced this pull request Aug 6, 2017
[ Upstream commit 6a146f3 ]

Since the introduction of ULD (Upper-Layer Drivers), the MSI-X
deallocating path changed in cxgb4: the driver frees the interrupts
of ULD when unregistering it or on shutdown PCI handler.

Problem is that if a MSI-X is not freed before deallocated in the PCI
layer, it will trigger a BUG() due to still "alive" interrupt being
tentatively quiesced.

The below trace was observed when doing a simple unbind of Chelsio's
adapter PCI function, like:
  "echo 001e:80:00.4 > /sys/bus/pci/drivers/cxgb4/unbind"

Trace:

  kernel BUG at drivers/pci/msi.c:352!
  Oops: Exception in kernel mode, sig: 5 [linusw#1]
  ...
  NIP [c0000000005a5e60] free_msi_irqs+0xa0/0x250
  LR [c0000000005a5e50] free_msi_irqs+0x90/0x250
  Call Trace:
  [c0000000005a5e50] free_msi_irqs+0x90/0x250 (unreliable)
  [c0000000005a72c4] pci_disable_msix+0x124/0x180
  [d000000011e06708] disable_msi+0x88/0xb0 [cxgb4]
  [d000000011e06948] free_some_resources+0xa8/0x160 [cxgb4]
  [d000000011e06d60] remove_one+0x170/0x3c0 [cxgb4]
  [c00000000058a910] pci_device_remove+0x70/0x110
  [c00000000064ef04] device_release_driver_internal+0x1f4/0x2c0
  ...

This patch fixes the issue by refactoring the shutdown path of ULD on
cxgb4 driver, by properly freeing and disabling interrupts on PCI
remove handler too.

Fixes: 0fbc81b ("Allocate resources dynamically for all cxgb4 ULD's")
Reported-by: Harsha Thyagaraja <hathyaga@in.ibm.com>
Signed-off-by: Guilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
philmmanjaro pushed a commit to philmmanjaro/linux-bfq that referenced this pull request Aug 6, 2017
commit 00c1475 upstream.

This fixes a typo where the wrong loop index was used to index
the kvmppc_xive_vcpu.queues[] array in xive_pre_save_scan().
The variable i contains the vcpu number; we need to index queues[]
using j, which iterates from 0 to KVMPPC_XIVE_Q_COUNT-1.

The effect of this bug is that things that save the interrupt
controller state, such as "virsh dump", on a VM with more than
8 vCPUs, result in xive_pre_save_queue() getting called on a
bogus queue structure, usually resulting in a crash like this:

[  501.821107] Unable to handle kernel paging request for data at address 0x00000084
[  501.821212] Faulting instruction address: 0xc008000004c7c6f8
[  501.821234] Oops: Kernel access of bad area, sig: 11 [linusw#1]
[  501.821305] SMP NR_CPUS=1024
[  501.821307] NUMA
[  501.821376] PowerNV
[  501.821470] Modules linked in: vhost_net vhost tap xt_CHECKSUM ipt_MASQUERADE nf_nat_masquerade_ipv4 ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 nf_conntrack_ipv6 nf_defrag_ipv6 xt_conntrack ip_set nfnetlink ebtable_nat ebtable_broute bridge stp llc ip6table_mangle ip6table_security ip6table_raw iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack libcrc32c iptable_mangle iptable_security iptable_raw ebtable_filter ebtables ip6table_filter ip6_tables ses enclosure scsi_transport_sas ipmi_powernv ipmi_devintf ipmi_msghandler powernv_op_panel kvm_hv nfsd auth_rpcgss oid_registry nfs_acl lockd grace sunrpc kvm tg3 ptp pps_core
[  501.822477] CPU: 3 PID: 3934 Comm: live_migration Not tainted 4.11.0-4.git8caa70f.el7.centos.ppc64le linusw#1
[  501.822633] task: c0000003f9e3ae80 task.stack: c0000003f9ed4000
[  501.822745] NIP: c008000004c7c6f8 LR: c008000004c7c628 CTR: 0000000030058018
[  501.822877] REGS: c0000003f9ed7980 TRAP: 0300   Not tainted  (4.11.0-4.git8caa70f.el7.centos.ppc64le)
[  501.823030] MSR: 9000000000009033 <SF,HV,EE,ME,IR,DR,RI,LE>
[  501.823047]   CR: 28022244  XER: 00000000
[  501.823203] CFAR: c008000004c7c77c DAR: 0000000000000084 DSISR: 40000000 SOFTE: 1
[  501.823203] GPR00: c008000004c7c628 c0000003f9ed7c00 c008000004c91450 00000000000000ff
[  501.823203] GPR04: c0000003f5580000 c0000003f559bf98 9000000000009033 0000000000000000
[  501.823203] GPR08: 0000000000000084 0000000000000000 00000000000001e0 9000000000001003
[  501.823203] GPR12: c00000000008a7d0 c00000000fdc1b00 000000000a9a0000 0000000000000000
[  501.823203] GPR16: 00000000402954e8 000000000a9a0000 0000000000000004 0000000000000000
[  501.823203] GPR20: 0000000000000008 c000000002e8f180 c000000002e8f1e0 0000000000000001
[  501.823203] GPR24: 0000000000000008 c0000003f5580008 c0000003f4564018 c000000002e8f1e8
[  501.823203] GPR28: 00003ff6e58bdc28 c0000003f4564000 0000000000000000 0000000000000000
[  501.825441] NIP [c008000004c7c6f8] xive_get_attr+0x3b8/0x5b0 [kvm]
[  501.825671] LR [c008000004c7c628] xive_get_attr+0x2e8/0x5b0 [kvm]
[  501.825887] Call Trace:
[  501.825991] [c0000003f9ed7c00] [c008000004c7c628] xive_get_attr+0x2e8/0x5b0 [kvm] (unreliable)
[  501.826312] [c0000003f9ed7cd0] [c008000004c62ec4] kvm_device_ioctl_attr+0x64/0xa0 [kvm]
[  501.826581] [c0000003f9ed7d20] [c008000004c62fcc] kvm_device_ioctl+0xcc/0xf0 [kvm]
[  501.826843] [c0000003f9ed7d40] [c000000000350c70] do_vfs_ioctl+0xd0/0x8c0
[  501.827060] [c0000003f9ed7de0] [c000000000351534] SyS_ioctl+0xd4/0xf0
[  501.827282] [c0000003f9ed7e30] [c00000000000b8e0] system_call+0x38/0xfc
[  501.827496] Instruction dump:
[  501.827632] 419e0078 3b760008 e9160008 83fb000c 83db0010 80fb0008 2f280000 60000000
[  501.827901] 60000000 60420000 419a0050 7be91764 <7d284c2c> 552a0ffe 7f8af040 419e003c
[  501.828176] ---[ end trace 2d0529a5bbbbafed ]---

Fixes: 5af5099 ("KVM: PPC: Book3S HV: Native usage of the XIVE interrupt controller")
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
philmmanjaro pushed a commit to philmmanjaro/linux-bfq that referenced this pull request Aug 6, 2017
commit 609805d upstream.

While punching a hole in a range that is not aligned with the sector size
(currently the same as the page size) we can end up leaving an extent map
in memory with a length that is smaller then the sector size or with a
start offset that is not aligned to the sector size. Both cases are not
expected and can lead to problems. This issue is easily detected
after the patch from commit a7e3b97 ("Btrfs: fix reported number of
inode blocks"), introduced in kernel 4.12-rc1, in a scenario like the
following for example:

  $ mkfs.btrfs -f /dev/sdb
  $ mount /dev/sdb /mnt
  $ xfs_io -c "pwrite -S 0xaa -b 100K 0 100K" /mnt/foo
  $ xfs_io -c "fpunch 60K 90K" /mnt/foo
  $ xfs_io -c "pwrite -S 0xbb -b 100K 50K 100K" /mnt/foo
  $ xfs_io -c "pwrite -S 0xcc -b 50K 100K 50K" /mnt/foo
  $ umount /mnt

After the unmount operation we can see several warnings emmitted due to
underflows related to space reservation counters:

[ 2837.443299] ------------[ cut here ]------------
[ 2837.447395] WARNING: CPU: 8 PID: 2474 at fs/btrfs/inode.c:9444 btrfs_destroy_inode+0xe8/0x27e [btrfs]
[ 2837.452108] Modules linked in: dm_flakey dm_mod ppdev parport_pc psmouse parport sg pcspkr acpi_cpufreq tpm_tis tpm_tis_core i2c_piix4 i2c_core evdev tpm button se
rio_raw sunrpc loop autofs4 ext4 crc16 jbd2 mbcache btrfs raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c crc32c_gene
ric raid1 raid0 multipath linear md_mod sr_mod cdrom sd_mod ata_generic virtio_scsi ata_piix libata virtio_pci virtio_ring virtio e1000 scsi_mod floppy
[ 2837.458389] CPU: 8 PID: 2474 Comm: umount Tainted: G        W       4.10.0-rc8-btrfs-next-43+ linusw#1
[ 2837.459754] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.1-0-gb3ef39f-prebuilt.qemu-project.org 04/01/2014
[ 2837.462379] Call Trace:
[ 2837.462379]  dump_stack+0x68/0x92
[ 2837.462379]  __warn+0xc2/0xdd
[ 2837.462379]  warn_slowpath_null+0x1d/0x1f
[ 2837.462379]  btrfs_destroy_inode+0xe8/0x27e [btrfs]
[ 2837.462379]  destroy_inode+0x3d/0x55
[ 2837.462379]  evict+0x177/0x17e
[ 2837.462379]  dispose_list+0x50/0x71
[ 2837.462379]  evict_inodes+0x132/0x141
[ 2837.462379]  generic_shutdown_super+0x3f/0xeb
[ 2837.462379]  kill_anon_super+0x12/0x1c
[ 2837.462379]  btrfs_kill_super+0x16/0x21 [btrfs]
[ 2837.462379]  deactivate_locked_super+0x30/0x68
[ 2837.462379]  deactivate_super+0x36/0x39
[ 2837.462379]  cleanup_mnt+0x58/0x76
[ 2837.462379]  __cleanup_mnt+0x12/0x14
[ 2837.462379]  task_work_run+0x77/0x9b
[ 2837.462379]  prepare_exit_to_usermode+0x9d/0xc5
[ 2837.462379]  syscall_return_slowpath+0x196/0x1b9
[ 2837.462379]  entry_SYSCALL_64_fastpath+0xab/0xad
[ 2837.462379] RIP: 0033:0x7f3ef3e6b9a7
[ 2837.462379] RSP: 002b:00007ffdd0d8de58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
[ 2837.462379] RAX: 0000000000000000 RBX: 0000556f76a39060 RCX: 00007f3ef3e6b9a7
[ 2837.462379] RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000556f76a3f910
[ 2837.462379] RBP: 0000556f76a3f910 R08: 0000556f76a3e670 R09: 0000000000000015
[ 2837.462379] R10: 00000000000006b4 R11: 0000000000000246 R12: 00007f3ef436ce64
[ 2837.462379] R13: 0000000000000000 R14: 0000556f76a39240 R15: 00007ffdd0d8e0e0
[ 2837.519355] ---[ end trace e79345fe24b30b8d ]---
[ 2837.596256] ------------[ cut here ]------------
[ 2837.597625] WARNING: CPU: 8 PID: 2474 at fs/btrfs/extent-tree.c:5699 btrfs_free_block_groups+0x246/0x3eb [btrfs]
[ 2837.603547] Modules linked in: dm_flakey dm_mod ppdev parport_pc psmouse parport sg pcspkr acpi_cpufreq tpm_tis tpm_tis_core i2c_piix4 i2c_core evdev tpm button serio_raw sunrpc loop autofs4 ext4 crc16 jbd2 mbcache btrfs raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c crc32c_generic raid1 raid0 multipath linear md_mod sr_mod cdrom sd_mod ata_generic virtio_scsi ata_piix libata virtio_pci virtio_ring virtio e1000 scsi_mod floppy
[ 2837.659372] CPU: 8 PID: 2474 Comm: umount Tainted: G        W       4.10.0-rc8-btrfs-next-43+ linusw#1
[ 2837.663359] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.1-0-gb3ef39f-prebuilt.qemu-project.org 04/01/2014
[ 2837.663359] Call Trace:
[ 2837.663359]  dump_stack+0x68/0x92
[ 2837.663359]  __warn+0xc2/0xdd
[ 2837.663359]  warn_slowpath_null+0x1d/0x1f
[ 2837.663359]  btrfs_free_block_groups+0x246/0x3eb [btrfs]
[ 2837.663359]  close_ctree+0x1dd/0x2e1 [btrfs]
[ 2837.663359]  ? evict_inodes+0x132/0x141
[ 2837.663359]  btrfs_put_super+0x15/0x17 [btrfs]
[ 2837.663359]  generic_shutdown_super+0x6a/0xeb
[ 2837.663359]  kill_anon_super+0x12/0x1c
[ 2837.663359]  btrfs_kill_super+0x16/0x21 [btrfs]
[ 2837.663359]  deactivate_locked_super+0x30/0x68
[ 2837.663359]  deactivate_super+0x36/0x39
[ 2837.663359]  cleanup_mnt+0x58/0x76
[ 2837.663359]  __cleanup_mnt+0x12/0x14
[ 2837.663359]  task_work_run+0x77/0x9b
[ 2837.663359]  prepare_exit_to_usermode+0x9d/0xc5
[ 2837.663359]  syscall_return_slowpath+0x196/0x1b9
[ 2837.663359]  entry_SYSCALL_64_fastpath+0xab/0xad
[ 2837.663359] RIP: 0033:0x7f3ef3e6b9a7
[ 2837.663359] RSP: 002b:00007ffdd0d8de58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
[ 2837.663359] RAX: 0000000000000000 RBX: 0000556f76a39060 RCX: 00007f3ef3e6b9a7
[ 2837.663359] RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000556f76a3f910
[ 2837.663359] RBP: 0000556f76a3f910 R08: 0000556f76a3e670 R09: 0000000000000015
[ 2837.663359] R10: 00000000000006b4 R11: 0000000000000246 R12: 00007f3ef436ce64
[ 2837.663359] R13: 0000000000000000 R14: 0000556f76a39240 R15: 00007ffdd0d8e0e0
[ 2837.739445] ---[ end trace e79345fe24b30b8e ]---
[ 2837.745595] ------------[ cut here ]------------
[ 2837.746412] WARNING: CPU: 8 PID: 2474 at fs/btrfs/extent-tree.c:5700 btrfs_free_block_groups+0x261/0x3eb [btrfs]
[ 2837.747955] Modules linked in: dm_flakey dm_mod ppdev parport_pc psmouse parport sg pcspkr acpi_cpufreq tpm_tis tpm_tis_core i2c_piix4 i2c_core evdev tpm button serio_raw sunrpc loop autofs4 ext4 crc16 jbd2 mbcache btrfs raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c crc32c_generic raid1 raid0 multipath linear md_mod sr_mod cdrom sd_mod ata_generic virtio_scsi ata_piix libata virtio_pci virtio_ring virtio e1000 scsi_mod floppy
[ 2837.755395] CPU: 8 PID: 2474 Comm: umount Tainted: G        W       4.10.0-rc8-btrfs-next-43+ linusw#1
[ 2837.756769] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.1-0-gb3ef39f-prebuilt.qemu-project.org 04/01/2014
[ 2837.758526] Call Trace:
[ 2837.758925]  dump_stack+0x68/0x92
[ 2837.759383]  __warn+0xc2/0xdd
[ 2837.759383]  warn_slowpath_null+0x1d/0x1f
[ 2837.759383]  btrfs_free_block_groups+0x261/0x3eb [btrfs]
[ 2837.759383]  close_ctree+0x1dd/0x2e1 [btrfs]
[ 2837.759383]  ? evict_inodes+0x132/0x141
[ 2837.759383]  btrfs_put_super+0x15/0x17 [btrfs]
[ 2837.759383]  generic_shutdown_super+0x6a/0xeb
[ 2837.759383]  kill_anon_super+0x12/0x1c
[ 2837.759383]  btrfs_kill_super+0x16/0x21 [btrfs]
[ 2837.759383]  deactivate_locked_super+0x30/0x68
[ 2837.759383]  deactivate_super+0x36/0x39
[ 2837.759383]  cleanup_mnt+0x58/0x76
[ 2837.759383]  __cleanup_mnt+0x12/0x14
[ 2837.759383]  task_work_run+0x77/0x9b
[ 2837.759383]  prepare_exit_to_usermode+0x9d/0xc5
[ 2837.759383]  syscall_return_slowpath+0x196/0x1b9
[ 2837.759383]  entry_SYSCALL_64_fastpath+0xab/0xad
[ 2837.759383] RIP: 0033:0x7f3ef3e6b9a7
[ 2837.759383] RSP: 002b:00007ffdd0d8de58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
[ 2837.759383] RAX: 0000000000000000 RBX: 0000556f76a39060 RCX: 00007f3ef3e6b9a7
[ 2837.759383] RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000556f76a3f910
[ 2837.759383] RBP: 0000556f76a3f910 R08: 0000556f76a3e670 R09: 0000000000000015
[ 2837.759383] R10: 00000000000006b4 R11: 0000000000000246 R12: 00007f3ef436ce64
[ 2837.759383] R13: 0000000000000000 R14: 0000556f76a39240 R15: 00007ffdd0d8e0e0
[ 2837.777063] ---[ end trace e79345fe24b30b8f ]---
[ 2837.778235] ------------[ cut here ]------------
[ 2837.778856] WARNING: CPU: 8 PID: 2474 at fs/btrfs/extent-tree.c:9825 btrfs_free_block_groups+0x348/0x3eb [btrfs]
[ 2837.791385] Modules linked in: dm_flakey dm_mod ppdev parport_pc psmouse parport sg pcspkr acpi_cpufreq tpm_tis tpm_tis_core i2c_piix4 i2c_core evdev tpm button serio_raw sunrpc loop autofs4 ext4 crc16 jbd2 mbcache btrfs raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c crc32c_generic raid1 raid0 multipath linear md_mod sr_mod cdrom sd_mod ata_generic virtio_scsi ata_piix libata virtio_pci virtio_ring virtio e1000 scsi_mod floppy
[ 2837.797711] CPU: 8 PID: 2474 Comm: umount Tainted: G        W       4.10.0-rc8-btrfs-next-43+ linusw#1
[ 2837.798594] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.1-0-gb3ef39f-prebuilt.qemu-project.org 04/01/2014
[ 2837.800118] Call Trace:
[ 2837.800515]  dump_stack+0x68/0x92
[ 2837.801015]  __warn+0xc2/0xdd
[ 2837.801471]  warn_slowpath_null+0x1d/0x1f
[ 2837.801698]  btrfs_free_block_groups+0x348/0x3eb [btrfs]
[ 2837.801698]  close_ctree+0x1dd/0x2e1 [btrfs]
[ 2837.801698]  ? evict_inodes+0x132/0x141
[ 2837.801698]  btrfs_put_super+0x15/0x17 [btrfs]
[ 2837.801698]  generic_shutdown_super+0x6a/0xeb
[ 2837.801698]  kill_anon_super+0x12/0x1c
[ 2837.801698]  btrfs_kill_super+0x16/0x21 [btrfs]
[ 2837.801698]  deactivate_locked_super+0x30/0x68
[ 2837.801698]  deactivate_super+0x36/0x39
[ 2837.801698]  cleanup_mnt+0x58/0x76
[ 2837.801698]  __cleanup_mnt+0x12/0x14
[ 2837.801698]  task_work_run+0x77/0x9b
[ 2837.801698]  prepare_exit_to_usermode+0x9d/0xc5
[ 2837.801698]  syscall_return_slowpath+0x196/0x1b9
[ 2837.801698]  entry_SYSCALL_64_fastpath+0xab/0xad
[ 2837.801698] RIP: 0033:0x7f3ef3e6b9a7
[ 2837.801698] RSP: 002b:00007ffdd0d8de58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
[ 2837.801698] RAX: 0000000000000000 RBX: 0000556f76a39060 RCX: 00007f3ef3e6b9a7
[ 2837.801698] RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000556f76a3f910
[ 2837.801698] RBP: 0000556f76a3f910 R08: 0000556f76a3e670 R09: 0000000000000015
[ 2837.801698] R10: 00000000000006b4 R11: 0000000000000246 R12: 00007f3ef436ce64
[ 2837.801698] R13: 0000000000000000 R14: 0000556f76a39240 R15: 00007ffdd0d8e0e0
[ 2837.818441] ---[ end trace e79345fe24b30b90 ]---
[ 2837.818991] BTRFS info (device sdc): space_info 1 has 7974912 free, is not full
[ 2837.819830] BTRFS info (device sdc): space_info total=8388608, used=417792, pinned=0, reserved=0, may_use=18446744073709547520, readonly=0

What happens in the above example is the following:

1) When punching the hole, at btrfs_punch_hole(), the variable tail_len
   is set to 2048 (as tail_start is 148Kb + 1 and offset + len is 150Kb).
   This results in the creation of an extent map with a length of 2Kb
   starting at file offset 148Kb, through find_first_non_hole() ->
   btrfs_get_extent().

2) The second write (first write after the hole punch operation), sets
   the range [50Kb, 152Kb[ to delalloc.

3) The third write, at btrfs_find_new_delalloc_bytes(), sees the extent
   map covering the range [148Kb, 150Kb[ and ends up calling
   set_extent_bit() for the same range, which results in splitting an
   existing extent state record, covering the range [148Kb, 152Kb[ into
   two 2Kb extent state records, covering the ranges [148Kb, 150Kb[ and
   [150Kb, 152Kb[.

4) Finally at lock_and_cleanup_extent_if_need(), immediately after calling
   btrfs_find_new_delalloc_bytes() we clear the delalloc bit from the
   range [100Kb, 152Kb[ which results in the btrfs_clear_bit_hook()
   callback being invoked against the two 2Kb extent state records that
   cover the ranges [148Kb, 150Kb[ and [150Kb, 152Kb[. When called against
   the first 2Kb extent state, it calls btrfs_delalloc_release_metadata()
   with a length argument of 2048 bytes. That function rounds up the length
   to a sector size aligned length, so it ends up considering a length of
   4096 bytes, and then calls calc_csum_metadata_size() which results in
   decrementing the inode's csum_bytes counter by 4096 bytes, so after
   it stays a value of 0 bytes. Then the same happens when
   btrfs_clear_bit_hook() is called against the second extent state that
   has a length of 2Kb, covering the range [150Kb, 152Kb[, the length is
   rounded up to 4096 and calc_csum_metadata_size() ends up being called
   to decrement 4096 bytes from the inode's csum_bytes counter, which
   at that time has a value of 0, leading to an underflow, which is
   exactly what triggers the first warning, at btrfs_destroy_inode().
   All the other warnings relate to several space accounting counters
   that underflow as well due to similar reasons.

A similar case but where the hole punching operation creates an extent map
with a start offset not aligned to the sector size is the following:

  $ mkfs.btrfs -f /dev/sdb
  $ mount /dev/sdb /mnt
  $ xfs_io -f -c "fpunch 695K 820K" $SCRATCH_MNT/bar
  $ xfs_io -c "pwrite -S 0xaa 1008K 307K" $SCRATCH_MNT/bar
  $ xfs_io -c "pwrite -S 0xbb -b 630K 1073K 630K" $SCRATCH_MNT/bar
  $ xfs_io -c "pwrite -S 0xcc -b 459K 1068K 459K" $SCRATCH_MNT/bar
  $ umount /mnt

During the unmount operation we get similar traces for the same reasons as
in the first example.

So fix the hole punching operation to make sure it never creates extent
maps with a length that is not aligned to the sector size nor with a start
offset that is not aligned to the sector size, as this breaks all
assumptions and it's a land mine.

Fixes: d778154 ("btrfs: Avoid trucating page or punching hole in a already existed hole.")
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
philmmanjaro pushed a commit to philmmanjaro/linux-bfq that referenced this pull request Aug 6, 2017
commit 24e52b1 upstream.

When doing an incremental send, while processing an extent that changed
between the parent and send snapshots and that extent was an inline extent
in the parent snapshot, it's possible to access a memory region beyond
the end of leaf if the inline extent is very small and it is the first
item in a leaf.

An example scenario is described below.

The send snapshot has the following leaf:

 leaf 33865728 items 33 free space 773 generation 46 owner 5
 fs uuid ab7090d8-dafd-4fb9-9246-723b6d2e2fb7
 chunk uuid 2d16478c-c704-4ab9-b574-68bff2281b1f
        (...)
        item 14 key (335 EXTENT_DATA 0) itemoff 3052 itemsize 53
                generation 36 type 1 (regular)
                extent data disk byte 12791808 nr 4096
                extent data offset 0 nr 4096 ram 4096
                extent compression 0 (none)
        item 15 key (335 EXTENT_DATA 8192) itemoff 2999 itemsize 53
                generation 36 type 1 (regular)
                extent data disk byte 138170368 nr 225280
                extent data offset 0 nr 225280 ram 225280
                extent compression 0 (none)
        (...)

And the parent snapshot has the following leaf:

 leaf 31272960 items 17 free space 17 generation 31 owner 5
 fs uuid ab7090d8-dafd-4fb9-9246-723b6d2e2fb7
 chunk uuid 2d16478c-c704-4ab9-b574-68bff2281b1f
        item 0 key (335 EXTENT_DATA 0) itemoff 3951 itemsize 44
                generation 31 type 0 (inline)
                inline extent data size 23 ram_bytes 613 compression 1 (zlib)
        (...)

When computing the send stream, it is detected that the extent of inode
335, at file offset 0, and at fs/btrfs/send.c:is_extent_unchanged() we
grab the leaf from the parent snapshot and access the inline extent item.
However, before jumping to the 'out' label, we access the 'offset' and
'disk_bytenr' fields of the extent item, which should not be done for
inline extents since the inlined data starts at the offset of the
'disk_bytenr' field and can be very small. For example accessing the
'offset' field of the file extent item results in the following trace:

[  599.705368] general protection fault: 0000 [linusw#1] PREEMPT SMP
[  599.706296] Modules linked in: btrfs psmouse i2c_piix4 ppdev acpi_cpufreq serio_raw parport_pc i2c_core evdev tpm_tis tpm_tis_core sg pcspkr parport tpm button su$
[  599.709340] CPU: 7 PID: 5283 Comm: btrfs Not tainted 4.10.0-rc8-btrfs-next-46+ linusw#1
[  599.709340] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.1-0-gb3ef39f-prebuilt.qemu-project.org 04/01/2014
[  599.709340] task: ffff88023eedd040 task.stack: ffffc90006658000
[  599.709340] RIP: 0010:read_extent_buffer+0xdb/0xf4 [btrfs]
[  599.709340] RSP: 0018:ffffc9000665ba00 EFLAGS: 00010286
[  599.709340] RAX: db73880000000000 RBX: 0000000000000000 RCX: 0000000000000001
[  599.709340] RDX: ffffc9000665ba60 RSI: db73880000000000 RDI: ffffc9000665ba5f
[  599.709340] RBP: ffffc9000665ba30 R08: 0000000000000001 R09: ffff88020dc5e098
[  599.709340] R10: 0000000000001000 R11: 0000160000000000 R12: 6db6db6db6db6db7
[  599.709340] R13: ffff880000000000 R14: 0000000000000000 R15: ffff88020dc5e088
[  599.709340] FS:  00007f519555a8c0(0000) GS:ffff88023f3c0000(0000) knlGS:0000000000000000
[  599.709340] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  599.709340] CR2: 00007f1411afd000 CR3: 0000000235f8e000 CR4: 00000000000006e0
[  599.709340] Call Trace:
[  599.709340]  btrfs_get_token_64+0x93/0xce [btrfs]
[  599.709340]  ? printk+0x48/0x50
[  599.709340]  btrfs_get_64+0xb/0xd [btrfs]
[  599.709340]  process_extent+0x3a1/0x1106 [btrfs]
[  599.709340]  ? btree_read_extent_buffer_pages+0x5/0xef [btrfs]
[  599.709340]  changed_cb+0xb03/0xb3d [btrfs]
[  599.709340]  ? btrfs_get_token_32+0x7a/0xcc [btrfs]
[  599.709340]  btrfs_compare_trees+0x432/0x53d [btrfs]
[  599.709340]  ? process_extent+0x1106/0x1106 [btrfs]
[  599.709340]  btrfs_ioctl_send+0x960/0xe26 [btrfs]
[  599.709340]  btrfs_ioctl+0x181b/0x1fed [btrfs]
[  599.709340]  ? trace_hardirqs_on_caller+0x150/0x1ac
[  599.709340]  vfs_ioctl+0x21/0x38
[  599.709340]  ? vfs_ioctl+0x21/0x38
[  599.709340]  do_vfs_ioctl+0x611/0x645
[  599.709340]  ? rcu_read_unlock+0x5b/0x5d
[  599.709340]  ? __fget+0x6d/0x79
[  599.709340]  SyS_ioctl+0x57/0x7b
[  599.709340]  entry_SYSCALL_64_fastpath+0x18/0xad
[  599.709340] RIP: 0033:0x7f51945eec47
[  599.709340] RSP: 002b:00007ffc21c13e98 EFLAGS: 00000202 ORIG_RAX: 0000000000000010
[  599.709340] RAX: ffffffffffffffda RBX: ffffffff81096459 RCX: 00007f51945eec47
[  599.709340] RDX: 00007ffc21c13f20 RSI: 0000000040489426 RDI: 0000000000000004
[  599.709340] RBP: ffffc9000665bf98 R08: 00007f519450d700 R09: 00007f519450d700
[  599.709340] R10: 00007f519450d9d0 R11: 0000000000000202 R12: 0000000000000046
[  599.709340] R13: ffffc9000665bf78 R14: 0000000000000000 R15: 00007f5195574040
[  599.709340]  ? trace_hardirqs_off_caller+0x43/0xb1
[  599.709340] Code: 29 f0 49 39 d8 4c 0f 47 c3 49 03 81 58 01 00 00 44 89 c1 4c 01 c2 4c 29 c3 48 c1 f8 03 49 0f af c4 48 c1 e0 0c 4c 01 e8 48 01 c6 <f3> a4 31 f6 4$
[  599.709340] RIP: read_extent_buffer+0xdb/0xf4 [btrfs] RSP: ffffc9000665ba00
[  599.762057] ---[ end trace fe00d7af61b9f49e ]---

This is because the 'offset' field starts at an offset of 37 bytes
(offsetof(struct btrfs_file_extent_item, offset)), has a length of 8
bytes and therefore attemping to read it causes a 1 byte access beyond
the end of the leaf, as the first item's content in a leaf is located
at the tail of the leaf, the item size is 44 bytes and the offset of
that field plus its length (37 + 8 = 45) goes beyond the item's size
by 1 byte.

So fix this by accessing the 'offset' and 'disk_bytenr' fields after
jumping to the 'out' label if we are processing an inline extent. We
move the reading operation of the 'disk_bytenr' field too because we
have the same problem as for the 'offset' field explained above when
the inline data is less then 8 bytes. The access to the 'generation'
field is also moved but just for the sake of grouping access to all
the fields.

Fixes: e1cbfd7 ("Btrfs: send, fix file hole not being preserved due to inline extent")
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
philmmanjaro pushed a commit to philmmanjaro/linux-bfq that referenced this pull request Aug 6, 2017
commit f9279c9 upstream.

The addition of the STARGET_REMOVE state had the side effect of
introducing a race condition that can cause a crash.

scsi_target_reap_ref_release() checks the starget->state to
see if it still in STARGET_CREATED, and if so, skips calling
transport_remove_device() and device_del(), because the starget->state
is only set to STARGET_RUNNING after scsi_target_add() has called
device_add() and transport_add_device().

However, if an rport loss occurs while a target is being scanned,
it can happen that scsi_remove_target() will be called while the
starget is still in the STARGET_CREATED state.  In this case, the
starget->state will be set to STARGET_REMOVE, and as a result,
scsi_target_reap_ref_release() will take the wrong path.  The end
result is a panic:

[ 1255.356653] Oops: 0000 [linusw#1] SMP
[ 1255.360154] Modules linked in: x86_pkg_temp_thermal kvm_intel kvm irqbypass crc32c_intel ghash_clmulni_i
[ 1255.393234] CPU: 5 PID: 149 Comm: kworker/u96:4 Tainted: G        W       4.11.0+ #8
[ 1255.401879] Hardware name: Dell Inc. PowerEdge R320/08VT7V, BIOS 2.0.22 11/19/2013
[ 1255.410327] Workqueue: scsi_wq_6 fc_scsi_scan_rport [scsi_transport_fc]
[ 1255.417720] task: ffff88060ca8c8c0 task.stack: ffffc900048a8000
[ 1255.424331] RIP: 0010:kernfs_find_ns+0x13/0xc0
[ 1255.429287] RSP: 0018:ffffc900048abbf0 EFLAGS: 00010246
[ 1255.435123] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
[ 1255.443083] RDX: 0000000000000000 RSI: ffffffff8188d659 RDI: 0000000000000000
[ 1255.451043] RBP: ffffc900048abc10 R08: 0000000000000000 R09: 0000012433fe0025
[ 1255.459005] R10: 0000000025e5a4b5 R11: 0000000025e5a4b5 R12: ffffffff8188d659
[ 1255.466972] R13: 0000000000000000 R14: ffff8805f55e5088 R15: 0000000000000000
[ 1255.474931] FS:  0000000000000000(0000) GS:ffff880616b40000(0000) knlGS:0000000000000000
[ 1255.483959] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1255.490370] CR2: 0000000000000068 CR3: 0000000001c09000 CR4: 00000000000406e0
[ 1255.498332] Call Trace:
[ 1255.501058]  kernfs_find_and_get_ns+0x31/0x60
[ 1255.505916]  sysfs_unmerge_group+0x1d/0x60
[ 1255.510498]  dpm_sysfs_remove+0x22/0x60
[ 1255.514783]  device_del+0xf4/0x2e0
[ 1255.518577]  ? device_remove_file+0x19/0x20
[ 1255.523241]  attribute_container_class_device_del+0x1a/0x20
[ 1255.529457]  transport_remove_classdev+0x4e/0x60
[ 1255.534607]  ? transport_add_class_device+0x40/0x40
[ 1255.540046]  attribute_container_device_trigger+0xb0/0xc0
[ 1255.546069]  transport_remove_device+0x15/0x20
[ 1255.551025]  scsi_target_reap_ref_release+0x25/0x40
[ 1255.556467]  scsi_target_reap+0x2e/0x40
[ 1255.560744]  __scsi_scan_target+0xaa/0x5b0
[ 1255.565312]  scsi_scan_target+0xec/0x100
[ 1255.569689]  fc_scsi_scan_rport+0xb1/0xc0 [scsi_transport_fc]
[ 1255.576099]  process_one_work+0x14b/0x390
[ 1255.580569]  worker_thread+0x4b/0x390
[ 1255.584651]  kthread+0x109/0x140
[ 1255.588251]  ? rescuer_thread+0x330/0x330
[ 1255.592730]  ? kthread_park+0x60/0x60
[ 1255.596815]  ret_from_fork+0x29/0x40
[ 1255.600801] Code: 24 08 48 83 42 40 01 5b 41 5c 5d c3 66 66 66 2e 0f 1f 84 00 00 00 00 00 66 66 66 66 90
[ 1255.621876] RIP: kernfs_find_ns+0x13/0xc0 RSP: ffffc900048abbf0
[ 1255.628479] CR2: 0000000000000068
[ 1255.632756] ---[ end trace 34a69ba0477d036f ]---

Fix this by adding another scsi_target state STARGET_CREATED_REMOVE
to distinguish this case.

Fixes: f05795d ("scsi: Add intermediate STARGET_REMOVE state to scsi_target_state")
Reported-by: David Jeffery <djeffery@redhat.com>
Signed-off-by: Ewan D. Milne <emilne@redhat.com>
Reviewed-by: Laurence Oberman <loberman@redhat.com>
Tested-by: Laurence Oberman <loberman@redhat.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
philmmanjaro pushed a commit to philmmanjaro/linux-bfq that referenced this pull request Aug 6, 2017
commit c46fc04 upstream.

Zorro reported following crash while having enabled
syscall tracing (CONFIG_FTRACE_SYSCALLS):

  Unable to handle kernel pointer dereference at virtual ...
  Oops: 0011 [linusw#1] SMP DEBUG_PAGEALLOC

  SNIP

  Call Trace:
  ([<000000000024d79c>] ftrace_syscall_enter+0xec/0x1d8)
   [<00000000001099c6>] do_syscall_trace_enter+0x236/0x2f8
   [<0000000000730f1c>] sysc_tracesys+0x1a/0x32
   [<000003fffcf946a2>] 0x3fffcf946a2
  INFO: lockdep is turned off.
  Last Breaking-Event-Address:
   [<000000000022dd44>] rb_event_data+0x34/0x40
  ---[ end trace 8c795f86b1b3f7b9 ]---

The crash happens in syscall_get_arguments function for
syscalls with zero arguments, that will try to access
first argument (args[0]) in event entry, but it's not
allocated.

Bail out of there are no arguments.

Reported-by: Zorro Lang <zlang@redhat.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
philmmanjaro pushed a commit to philmmanjaro/linux-bfq that referenced this pull request Aug 6, 2017
…play

commit 7bc7b77 upstream.

amd_powerplay_destroy() expects a handle pointing to a struct pp_instance.
On chips without PowerPlay, pp_handle points to a struct amdgpu_device. The
resulting attempt to kfree() fields of the wrong struct ends in fire:

[   91.560405] BUG: unable to handle kernel paging request at ffffebe000000620
[   91.560414] IP: kfree+0x57/0x160
[   91.560416] PGD 0
[   91.560416] P4D 0

[   91.560420] Oops: 0000 [linusw#1] SMP
[   91.560422] Modules linked in: tun x86_pkg_temp_thermal crc32_pclmul ghash_clmulni_intel efivarfs amdgpu(-) i2c_algo_bit drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm drm
[   91.560438] CPU: 6 PID: 3598 Comm: rmmod Not tainted 4.12.0-rc5-drm-next-4.13-ttmpatch+ linusw#1
[   91.560443] Hardware name: Gigabyte Technology Co., Ltd. Z97X-UD3H-BK/Z97X-UD3H-BK-CF, BIOS F6 06/17/2014
[   91.560448] task: ffff8805063d6a00 task.stack: ffffc90003400000
[   91.560451] RIP: 0010:kfree+0x57/0x160
[   91.560454] RSP: 0018:ffffc90003403cc0 EFLAGS: 00010286
[   91.560457] RAX: 000077ff80000000 RBX: 00000000000186a0 RCX: 0000000180400035
[   91.560460] RDX: 0000000180400036 RSI: ffffea001418e740 RDI: ffffea0000000000
[   91.560463] RBP: ffffc90003403cd8 R08: 000000000639d201 R09: 0000000180400035
[   91.560467] R10: ffffebe000000600 R11: 0000000000000300 R12: ffff880500530030
[   91.560470] R13: ffffffffa01e70fc R14: 00000000ffffffff R15: ffff880500530000
[   91.560473] FS:  00007f7e500c3700(0000) GS:ffff88051ed80000(0000) knlGS:0000000000000000
[   91.560478] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   91.560480] CR2: ffffebe000000620 CR3: 0000000503103000 CR4: 00000000001406e0
[   91.560483] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   91.560487] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   91.560489] Call Trace:
[   91.560530]  amd_powerplay_destroy+0x1c/0x60 [amdgpu]
[   91.560558]  amdgpu_pp_late_fini+0x44/0x60 [amdgpu]
[   91.560575]  amdgpu_fini+0x254/0x490 [amdgpu]
[   91.560593]  amdgpu_device_fini+0x58/0x1b0 [amdgpu]
[   91.560610]  amdgpu_driver_unload_kms+0x4f/0xa0 [amdgpu]
[   91.560622]  drm_dev_unregister+0x3c/0xe0 [drm]
[   91.560638]  amdgpu_pci_remove+0x19/0x30 [amdgpu]
[   91.560643]  pci_device_remove+0x39/0xc0
[   91.560648]  device_release_driver_internal+0x155/0x210
[   91.560651]  driver_detach+0x38/0x70
[   91.560655]  bus_remove_driver+0x4c/0xa0
[   91.560658]  driver_unregister+0x2c/0x40
[   91.560662]  pci_unregister_driver+0x21/0x90
[   91.560689]  amdgpu_exit+0x15/0x406 [amdgpu]
[   91.560694]  SyS_delete_module+0x1a8/0x270
[   91.560698]  ? exit_to_usermode_loop+0x92/0xa0
[   91.560702]  entry_SYSCALL_64_fastpath+0x13/0x94
[   91.560705] RIP: 0033:0x7f7e4fc118e7
[   91.560708] RSP: 002b:00007fff978ca118 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0
[   91.560713] RAX: ffffffffffffffda RBX: 000055afe21bc200 RCX: 00007f7e4fc118e7
[   91.560716] RDX: 000000000000000a RSI: 0000000000000800 RDI: 000055afe21bc268
[   91.560719] RBP: 0000000000000003 R08: 0000000000000000 R09: 1999999999999999
[   91.560722] R10: 0000000000000883 R11: 0000000000000206 R12: 00007fff978c9100
[   91.560725] R13: 0000000000000000 R14: 0000000000000000 R15: 000055afe21bc200
[   91.560728] Code: 00 00 00 80 ff 77 00 00 48 bf 00 00 00 00 00 ea ff ff 49 01 da 48 0f 42 05 57 33 bd 00 49 01 c2 49 c1 ea 0c 49 c1 e2 06 49 01 fa <49> 8b 42 20 48 8d 78 ff a8 01 4c 0f 45 d7 49 8b 52 20 48 8d 42
[   91.560759] RIP: kfree+0x57/0x160 RSP: ffffc90003403cc0
[   91.560761] CR2: ffffebe000000620
[   91.560765] ---[ end trace 08a9f3cd82223c1d ]---

Fixes: 1c86380 (drm/amd/powerplay: refine powerplay interface.)
Signed-off-by: John Brooks <john@fastquake.com>
Acked-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
philmmanjaro pushed a commit to philmmanjaro/linux-bfq that referenced this pull request Aug 6, 2017
commit 8046e19 upstream.

We unref the man->move fence in ttm_bo_clean_mm() and then call
ttm_bo_force_list_clean() which waits on it, except the refcount is now
zero so a warning is generated (or worse):

[149492.279301] refcount_t: increment on 0; use-after-free.
[149492.279309] ------------[ cut here ]------------
[149492.279315] WARNING: CPU: 3 PID: 18726 at lib/refcount.c:150 refcount_inc+0x2b/0x30
[149492.279315] Modules linked in: vhost_net vhost tun x86_pkg_temp_thermal crc32_pclmul ghash_clmulni_intel efivarfs amdgpu(
-) i2c_algo_bit drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm drm
[149492.279326] CPU: 3 PID: 18726 Comm: rmmod Not tainted 4.12.0-rc5-drm-next-4.13-ttmpatch+ linusw#1
[149492.279326] Hardware name: Gigabyte Technology Co., Ltd. Z97X-UD3H-BK/Z97X-UD3H-BK-CF, BIOS F6 06/17/2014
[149492.279327] task: ffff8804ddfedcc0 task.stack: ffffc90008d20000
[149492.279329] RIP: 0010:refcount_inc+0x2b/0x30
[149492.279330] RSP: 0018:ffffc90008d23c30 EFLAGS: 00010286
[149492.279331] RAX: 000000000000002b RBX: 0000000000000170 RCX: 0000000000000000
[149492.279331] RDX: 0000000000000000 RSI: ffff88051ecccbe8 RDI: ffff88051ecccbe8
[149492.279332] RBP: ffffc90008d23c30 R08: 0000000000000001 R09: 00000000000003ee
[149492.279333] R10: ffffc90008d23bb0 R11: 00000000000003ee R12: ffff88043aaac960
[149492.279333] R13: ffff8805005e28a8 R14: 0000000000000002 R15: ffff88050115e178
[149492.279334] FS:  00007fc540168700(0000) GS:ffff88051ecc0000(0000) knlGS:0000000000000000
[149492.279335] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[149492.279336] CR2: 00007fc3e8654140 CR3: 000000027ba77000 CR4: 00000000001426e0
[149492.279337] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[149492.279337] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[149492.279338] Call Trace:
[149492.279345]  ttm_bo_force_list_clean+0xb9/0x110 [ttm]
[149492.279348]  ttm_bo_clean_mm+0x7a/0xe0 [ttm]
[149492.279375]  amdgpu_ttm_fini+0xc9/0x1f0 [amdgpu]
[149492.279392]  amdgpu_bo_fini+0x12/0x40 [amdgpu]
[149492.279415]  gmc_v7_0_sw_fini+0x32/0x40 [amdgpu]
[149492.279430]  amdgpu_fini+0x2c9/0x490 [amdgpu]
[149492.279445]  amdgpu_device_fini+0x58/0x1b0 [amdgpu]
[149492.279461]  amdgpu_driver_unload_kms+0x4f/0xa0 [amdgpu]
[149492.279470]  drm_dev_unregister+0x3c/0xe0 [drm]
[149492.279485]  amdgpu_pci_remove+0x19/0x30 [amdgpu]
[149492.279487]  pci_device_remove+0x39/0xc0
[149492.279490]  device_release_driver_internal+0x155/0x210
[149492.279491]  driver_detach+0x38/0x70
[149492.279493]  bus_remove_driver+0x4c/0xa0
[149492.279494]  driver_unregister+0x2c/0x40
[149492.279496]  pci_unregister_driver+0x21/0x90
[149492.279520]  amdgpu_exit+0x15/0x406 [amdgpu]
[149492.279523]  SyS_delete_module+0x1a8/0x270
[149492.279525]  ? exit_to_usermode_loop+0x92/0xa0
[149492.279528]  entry_SYSCALL_64_fastpath+0x13/0x94
[149492.279529] RIP: 0033:0x7fc53fcb68e7
[149492.279529] RSP: 002b:00007ffcfbfaabb8 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0
[149492.279531] RAX: ffffffffffffffda RBX: 0000563117adb200 RCX: 00007fc53fcb68e7
[149492.279531] RDX: 000000000000000a RSI: 0000000000000800 RDI: 0000563117adb268
[149492.279532] RBP: 0000000000000003 R08: 0000000000000000 R09: 1999999999999999
[149492.279533] R10: 0000000000000883 R11: 0000000000000206 R12: 00007ffcfbfa9ba0
[149492.279533] R13: 0000000000000000 R14: 0000000000000000 R15: 0000563117adb200
[149492.279534] Code: 55 48 89 e5 e8 77 fe ff ff 84 c0 74 02 5d c3 80 3d 40 f2 a4 00 00 75 f5 48 c7 c7 20 3c ca 81 c6 05 30 f2 a4 00 01 e8 91 f0 d7 ff <0f> ff 5d c3 90 55 48 89 fe bf 01 00 00 00 48 89 e5 e8 9f fe ff
[149492.279557] ---[ end trace 2d4e0ffcb66a1016 ]---

Unref the fence *after* waiting for it.

v2: Set man->move to NULL after dropping the last ref (Christian König)

Fixes: aff98ba (drm/ttm: wait for eviction in ttm_bo_force_list_clean)
Signed-off-by: John Brooks <john@fastquake.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
philmmanjaro pushed a commit to philmmanjaro/linux-bfq that referenced this pull request Aug 6, 2017
commit cdea465 upstream.

A vendor with a system having more than 128 CPUs occasionally encounters
the following crash during shutdown. This is not an easily reproduceable
event, but the vendor was able to provide the following analysis of the
crash, which exhibits the same footprint each time.

crash> bt
PID: 0      TASK: ffff88017c70ce70  CPU: 5   COMMAND: "swapper/5"
 #0 [ffff88085c143ac8] machine_kexec at ffffffff81059c8b
 linusw#1 [ffff88085c143b28] __crash_kexec at ffffffff811052e2
 #2 [ffff88085c143bf8] crash_kexec at ffffffff811053d0
 #3 [ffff88085c143c10] oops_end at ffffffff8168ef88
 #4 [ffff88085c143c38] no_context at ffffffff8167ebb3
 #5 [ffff88085c143c88] __bad_area_nosemaphore at ffffffff8167ec49
 #6 [ffff88085c143cd0] bad_area_nosemaphore at ffffffff8167edb3
 #7 [ffff88085c143ce0] __do_page_fault at ffffffff81691d1e
 #8 [ffff88085c143d40] do_page_fault at ffffffff81691ec5
 #9 [ffff88085c143d70] page_fault at ffffffff8168e188
    [exception RIP: unknown or invalid address]
    RIP: ffffffffa053c800  RSP: ffff88085c143e28  RFLAGS: 00010206
    RAX: ffff88017c72bfd8  RBX: ffff88017a8dc000  RCX: ffff8810588b5ac8
    RDX: ffff8810588b5a00  RSI: ffffffffa053c800  RDI: ffff8810588b5a00
    RBP: ffff88085c143e58   R8: ffff88017c70d408   R9: ffff88017a8dc000
    R10: 0000000000000002  R11: ffff88085c143da0  R12: ffff8810588b5ac8
    R13: 0000000000000100  R14: ffffffffa053c800  R15: ffff8810588b5a00
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
    <IRQ stack>
    [exception RIP: cpuidle_enter_state+82]
    RIP: ffffffff81514192  RSP: ffff88017c72be50  RFLAGS: 00000202
    RAX: 0000001e4c3c6f16  RBX: 000000000000f8a0  RCX: 0000000000000018
    RDX: 0000000225c17d03  RSI: ffff88017c72bfd8  RDI: 0000001e4c3c6f16
    RBP: ffff88017c72be78   R8: 000000000000237e   R9: 0000000000000018
    R10: 0000000000002494  R11: 0000000000000001  R12: ffff88017c72be20
    R13: ffff88085c14f8e0  R14: 0000000000000082  R15: 0000001e4c3bb400
    ORIG_RAX: ffffffffffffff10  CS: 0010  SS: 0018

This is the corresponding stack trace

It has crashed because the area pointed with RIP extracted from timer
element is already removed during a shutdown process.

The function is smi_timeout().

And we think ffff8810588b5a00 in RDX is a parameter struct smi_info

crash> rd ffff8810588b5a00 20
ffff8810588b5a00:  ffff8810588b6000 0000000000000000   .`.X............
ffff8810588b5a10:  ffff880853264400 ffffffffa05417e0   .D&S......T.....
ffff8810588b5a20:  24a024a000000000 0000000000000000   .....$.$........
ffff8810588b5a30:  0000000000000000 0000000000000000   ................
ffff8810588b5a30:  0000000000000000 0000000000000000   ................
ffff8810588b5a40:  ffffffffa053a040 ffffffffa053a060   @.S.....`.S.....
ffff8810588b5a50:  0000000000000000 0000000100000001   ................
ffff8810588b5a60:  0000000000000000 0000000000000e00   ................
ffff8810588b5a70:  ffffffffa053a580 ffffffffa053a6e0   ..S.......S.....
ffff8810588b5a80:  ffffffffa053a4a0 ffffffffa053a250   ..S.....P.S.....
ffff8810588b5a90:  0000000500000002 0000000000000000   ................

Unfortunately the top of this area is already detroyed by someone.
But because of two reasonns we think this is struct smi_info
 1) The address included in between  ffff8810588b5a70 and ffff8810588b5a80:
  are inside of ipmi_si_intf.c  see crash> module ffff88085779d2c0

 2) We've found the area which point this.
  It is offset 0x68 of  ffff880859df4000

crash> rd  ffff880859df4000 100
ffff880859df4000:  0000000000000000 0000000000000001   ................
ffff880859df4010:  ffffffffa0535290 dead000000000200   .RS.............
ffff880859df4020:  ffff880859df4020 ffff880859df4020    @.Y.... @.Y....
ffff880859df4030:  0000000000000002 0000000000100010   ................
ffff880859df4040:  ffff880859df4040 ffff880859df4040   @@.Y....@@.Y....
ffff880859df4050:  0000000000000000 0000000000000000   ................
ffff880859df4060:  0000000000000000 ffff8810588b5a00   .........Z.X....
ffff880859df4070:  0000000000000001 ffff880859df4078   ........x@.Y....

 If we regards it as struct ipmi_smi in shutdown process
 it looks consistent.

The remedy for this apparent race is affixed below.

Signed-off-by: Tony Camuso <tcamuso@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This was first introduced in 7ea0ed2 ipmi: Make the
message handler easier to use for SMI interfaces
where some code was moved outside of the rcu_read_lock()
and the lock was not added.

Signed-off-by: Corey Minyard <cminyard@mvista.com>
philmmanjaro pushed a commit to philmmanjaro/linux-bfq that referenced this pull request Aug 6, 2017
commit d1aa245 upstream.

generic/361 reports below warning, this is because: once, there is
someone entering into critical region of sbi.cp_lock, if write_end_io.
f2fs_stop_checkpoint is invoked from an triggered IRQ, we will encounter
deadlock.

So this patch changes to use spin_{,un}lock_irq{save,restore} to create
critical region without IRQ enabled to avoid potential deadlock.

 irq event stamp: 83391573
 loop: Write error at byte offset 438729728, length 1024.
 hardirqs last  enabled at (83391573): [<c1809752>] restore_all+0xf/0x65
 hardirqs last disabled at (83391572): [<c1809eac>] reschedule_interrupt+0x30/0x3c
 loop: Write error at byte offset 438860288, length 1536.
 softirqs last  enabled at (83389244): [<c180cc4e>] __do_softirq+0x1ae/0x476
 softirqs last disabled at (83389237): [<c101ca7c>] do_softirq_own_stack+0x2c/0x40
 loop: Write error at byte offset 438990848, length 2048.
 ================================
 WARNING: inconsistent lock state
 4.12.0-rc2+ #30 Tainted: G           O
 --------------------------------
 inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W} usage.
 xfs_io/7959 [HC1[1]:SC0[0]:HE0:SE1] takes:
  (&(&sbi->cp_lock)->rlock){?.+...}, at: [<f96f96cc>] f2fs_stop_checkpoint+0x1c/0x50 [f2fs]
 {HARDIRQ-ON-W} state was registered at:
   __lock_acquire+0x527/0x7b0
   lock_acquire+0xae/0x220
   _raw_spin_lock+0x42/0x50
   do_checkpoint+0x165/0x9e0 [f2fs]
   write_checkpoint+0x33f/0x740 [f2fs]
   __f2fs_sync_fs+0x92/0x1f0 [f2fs]
   f2fs_sync_fs+0x12/0x20 [f2fs]
   sync_filesystem+0x67/0x80
   generic_shutdown_super+0x27/0x100
   kill_block_super+0x22/0x50
   kill_f2fs_super+0x3a/0x40 [f2fs]
   deactivate_locked_super+0x3d/0x70
   deactivate_super+0x40/0x60
   cleanup_mnt+0x39/0x70
   __cleanup_mnt+0x10/0x20
   task_work_run+0x69/0x80
   exit_to_usermode_loop+0x57/0x85
   do_fast_syscall_32+0x18c/0x1b0
   entry_SYSENTER_32+0x4c/0x7b
 irq event stamp: 1957420
 hardirqs last  enabled at (1957419): [<c1808f37>] _raw_spin_unlock_irq+0x27/0x50
 hardirqs last disabled at (1957420): [<c1809f9c>] call_function_single_interrupt+0x30/0x3c
 softirqs last  enabled at (1953784): [<c180cc4e>] __do_softirq+0x1ae/0x476
 softirqs last disabled at (1953773): [<c101ca7c>] do_softirq_own_stack+0x2c/0x40

 other info that might help us debug this:
  Possible unsafe locking scenario:

        CPU0
        ----
   lock(&(&sbi->cp_lock)->rlock);
   <Interrupt>
     lock(&(&sbi->cp_lock)->rlock);

  *** DEADLOCK ***

 2 locks held by xfs_io/7959:
  #0:  (sb_writers#13){.+.+.+}, at: [<c11fd7ca>] vfs_write+0x16a/0x190
  linusw#1:  (&sb->s_type->i_mutex_key#16){+.+.+.}, at: [<f96e33f5>] f2fs_file_write_iter+0x25/0x140 [f2fs]

 stack backtrace:
 CPU: 2 PID: 7959 Comm: xfs_io Tainted: G           O    4.12.0-rc2+ #30
 Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
 Call Trace:
  dump_stack+0x5f/0x92
  print_usage_bug+0x1d3/0x1dd
  ? check_usage_backwards+0xe0/0xe0
  mark_lock+0x23d/0x280
  __lock_acquire+0x699/0x7b0
  ? __this_cpu_preempt_check+0xf/0x20
  ? trace_hardirqs_off_caller+0x91/0xe0
  lock_acquire+0xae/0x220
  ? f2fs_stop_checkpoint+0x1c/0x50 [f2fs]
  _raw_spin_lock+0x42/0x50
  ? f2fs_stop_checkpoint+0x1c/0x50 [f2fs]
  f2fs_stop_checkpoint+0x1c/0x50 [f2fs]
  f2fs_write_end_io+0x147/0x150 [f2fs]
  bio_endio+0x7a/0x1e0
  blk_update_request+0xad/0x410
  blk_mq_end_request+0x16/0x60
  lo_complete_rq+0x3c/0x70
  __blk_mq_complete_request_remote+0x11/0x20
  flush_smp_call_function_queue+0x6d/0x120
  ? debug_smp_processor_id+0x12/0x20
  generic_smp_call_function_single_interrupt+0x12/0x30
  smp_call_function_single_interrupt+0x25/0x40
  call_function_single_interrupt+0x37/0x3c
 EIP: _raw_spin_unlock_irq+0x2d/0x50
 EFLAGS: 00000296 CPU: 2
 EAX: 00000001 EBX: d2ccc51c ECX: 00000001 EDX: c1aacebd
 ESI: 00000000 EDI: 00000000 EBP: c96c9d1c ESP: c96c9d18
  DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
  ? inherit_task_group.isra.98.part.99+0x6b/0xb0
  __add_to_page_cache_locked+0x1d4/0x290
  add_to_page_cache_lru+0x38/0xb0
  pagecache_get_page+0x8e/0x200
  f2fs_write_begin+0x96/0xf00 [f2fs]
  ? trace_hardirqs_on_caller+0xdd/0x1c0
  ? current_time+0x17/0x50
  ? trace_hardirqs_on+0xb/0x10
  generic_perform_write+0xa9/0x170
  __generic_file_write_iter+0x1a2/0x1f0
  ? f2fs_preallocate_blocks+0x137/0x160 [f2fs]
  f2fs_file_write_iter+0x6e/0x140 [f2fs]
  ? __lock_acquire+0x429/0x7b0
  __vfs_write+0xc1/0x140
  vfs_write+0x9b/0x190
  SyS_pwrite64+0x63/0xa0
  do_fast_syscall_32+0xa1/0x1b0
  entry_SYSENTER_32+0x4c/0x7b
 EIP: 0xb7786c61
 EFLAGS: 00000293 CPU: 2
 EAX: ffffffda EBX: 00000003 ECX: 08416000 EDX: 00001000
 ESI: 18b24000 EDI: 00000000 EBP: 00000003 ESP: bf9b36b0
  DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 007b

Fixes: aaec2b1 ("f2fs: introduce cp_lock to protect updating of ckpt_flags")
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
philmmanjaro pushed a commit to philmmanjaro/linux-bfq that referenced this pull request Aug 6, 2017
commit 340d394 upstream.

The driver checks port->exists twice in i8042_interrupt(), first when
trying to assign temporary "serio" variable, and second time when deciding
whether it should call serio_interrupt(). The value of port->exists may
change between the 2 checks, and we may end up calling serio_interrupt()
with a NULL pointer:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000050
IP: [<ffffffff8150feaf>] _spin_lock_irqsave+0x1f/0x40
PGD 0
Oops: 0002 [linusw#1] SMP
last sysfs file:
CPU 0
Modules linked in:

Pid: 1, comm: swapper Not tainted 2.6.32-358.el6.x86_64 linusw#1 QEMU Standard PC (i440FX + PIIX, 1996)
RIP: 0010:[<ffffffff8150feaf>]  [<ffffffff8150feaf>] _spin_lock_irqsave+0x1f/0x40
RSP: 0018:ffff880028203cc0  EFLAGS: 00010082
RAX: 0000000000010000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000282 RSI: 0000000000000098 RDI: 0000000000000050
RBP: ffff880028203cc0 R08: ffff88013e79c000 R09: ffff880028203ee0
R10: 0000000000000298 R11: 0000000000000282 R12: 0000000000000050
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000098
FS:  0000000000000000(0000) GS:ffff880028200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0018 ES: 0018 CR0: 000000008005003b
CR2: 0000000000000050 CR3: 0000000001a85000 CR4: 00000000001407f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process swapper (pid: 1, threadinfo ffff88013e79c000, task ffff88013e79b500)
Stack:
ffff880028203d00 ffffffff813de186 ffffffffffffff02 0000000000000000
<d> 0000000000000000 0000000000000000 0000000000000000 0000000000000098
<d> ffff880028203d70 ffffffff813e0162 ffff880028203d20 ffffffff8103b8ac
Call Trace:
<IRQ>
 [<ffffffff813de186>] serio_interrupt+0x36/0xa0
[<ffffffff813e0162>] i8042_interrupt+0x132/0x3a0
[<ffffffff8103b8ac>] ? kvm_clock_read+0x1c/0x20
[<ffffffff8103b8b9>] ? kvm_clock_get_cycles+0x9/0x10
[<ffffffff810e1640>] handle_IRQ_event+0x60/0x170
[<ffffffff8103b154>] ? kvm_guest_apic_eoi_write+0x44/0x50
[<ffffffff810e3d8e>] handle_edge_irq+0xde/0x180
[<ffffffff8100de89>] handle_irq+0x49/0xa0
[<ffffffff81516c8c>] do_IRQ+0x6c/0xf0
[<ffffffff8100b9d3>] ret_from_intr+0x0/0x11
[<ffffffff81076f63>] ? __do_softirq+0x73/0x1e0
[<ffffffff8109b75b>] ? hrtimer_interrupt+0x14b/0x260
[<ffffffff8100c1cc>] ? call_softirq+0x1c/0x30
[<ffffffff8100de05>] ? do_softirq+0x65/0xa0
[<ffffffff81076d95>] ? irq_exit+0x85/0x90
[<ffffffff81516d80>] ? smp_apic_timer_interrupt+0x70/0x9b
[<ffffffff8100bb93>] ? apic_timer_interrupt+0x13/0x20

To avoid the issue let's change the second check to test whether serio is
NULL or not.

Also, let's take i8042_lock in i8042_start() and i8042_stop() instead of
trying to be overly smart and using memory barriers.

Signed-off-by: Chen Hong <chenhong3@huawei.com>
[dtor: take lock in i8042_start()/i8042_stop()]
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
philmmanjaro pushed a commit to philmmanjaro/linux-bfq that referenced this pull request Aug 6, 2017
commit 0e4097c upstream.

Recent kernels trigger this warning:

 BUG: using smp_processor_id() in preemptible [00000000] code: 99-trinity/181
 caller is debug_smp_processor_id+0x17/0x19
 CPU: 0 PID: 181 Comm: 99-trinity Not tainted 4.12.0-01059-g2a42eb9 linusw#1
 Call Trace:
  dump_stack+0x82/0xb8
  check_preemption_disabled()
  debug_smp_processor_id()
  vtime_delta()
  task_cputime()
  thread_group_cputime()
  thread_group_cputime_adjusted()
  wait_consider_task()
  do_wait()
  SYSC_wait4()
  do_syscall_64()
  entry_SYSCALL64_slow_path()

As Frederic pointed out:

| Although those sched_clock_cpu() things seem to only matter when the
| sched_clock() is unstable. And that stability is a condition for nohz_full
| to work anyway. So probably sched_clock() alone would be enough.

This patch fixes it by replacing sched_clock_cpu() with sched_clock() to
avoid calling smp_processor_id() in a preemptible context.

Reported-by: Xiaolong Ye <xiaolong.ye@intel.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1499586028-7402-1-git-send-email-wanpeng.li@hotmail.com
[ Prettified the changelog. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
philmmanjaro pushed a commit to philmmanjaro/linux-bfq that referenced this pull request Aug 15, 2017
While I was testing the upcoming adv7533 CEC support with my Dragonboard c410
I encountered this NULL pointer dereference:

[   17.912822] Unable to handle kernel NULL pointer dereference at virtual address 000000e8
[   17.917191] user pgtable: 4k pages, 48-bit VAs, pgd = ffff800030e9f000
[   17.925249] [00000000000000e8] *pgd=00000000b0daf003, *pud=0000000000000000
[   17.931650] Internal error: Oops: 96000005 [linusw#1] PREEMPT SMP
[   17.938395] Modules linked in: btqcomsmd btqca arc4 wcn36xx mac80211 bluetooth cfg80211 ecdh_generic r8152 snd_soc_hdmi_codec adv7511 cec
qcom_wcnss_pil msm mdt_loader drm_kms_helper msm_rng rng_core drm
[   17.943967] CPU: 0 PID: 1684 Comm: Xorg Tainted: G        W       4.13.0-rc1-dragonboard #111
[   17.962005] Hardware name: Qualcomm Technologies, Inc. APQ 8016 SBC (DT)
[   17.970685] task: ffff800031236c00 task.stack: ffff800033fbc000
[   17.977582] PC is at msm_gem_unmap_vma+0x20/0x80 [msm]
[   17.983213] LR is at put_iova+0x60/0xb8 [msm]
[   17.988303] pc : [<ffff000000ac2d58>] lr : [<ffff000000ac07c8>] pstate: 20000145
[   17.992733] sp : ffff800033fbfb30
[   18.000193] x29: ffff800033fbfb30 x28: ffff800030b5f000
[   18.003407] x27: 00000000000000b4 x26: ffff0000009f8cd8
[   18.008789] x25: 0000000000000004 x24: dead000000000100
[   18.014085] x23: dead000000000200 x22: ffff800030b5fd40
[   18.019379] x21: ffff800030b5fc00 x20: 0000000000000000
[   18.024675] x19: ffff80003082bf00 x18: 0000000000000000
[   18.029970] x17: 0000ffffb3347e70 x16: ffff000008207638
[   18.035265] x15: 0000000000000053 x14: 0000000000000000
[   18.040560] x13: 0000000000000038 x12: 0101010101010101
[   18.045855] x11: 7f7f7f7f7f7f7f7f x10: 0000000000000040
[   18.051150] x9 : ffff800030b5f038 x8 : ffff800031657b50
[   18.056446] x7 : ffff800031657b78 x6 : 0000000000000000
[   18.061740] x5 : 0000000000000000 x4 : 00000000b5c01000
[   18.067036] x3 : 0000000000000000 x2 : ffff8000337bf300
[   18.072330] x1 : ffff80003082bf00 x0 : 0000000000000000
[   18.077629] Process Xorg (pid: 1684, stack limit = 0xffff800033fbc000)
[   18.082925] Stack: (0xffff800033fbfb30 to 0xffff800033fc0000)
[   18.089262] fb20:                                   ffff800033fbfb60 ffff000000ac07c8
[   18.095081] fb40: ffff80003082bf00 ffff800030b5fc90 ffff800030b5fc00 ffff000000abf4a0
[   18.102893] fb60: ffff800033fbfba0 ffff000000ac16b0 ffff800030b5fc00 ffff8000338ff870
[   18.110706] fb80: ffff8000338ff800 ffff800030b5fc00 ffff800030b5fda8 ffff800033fbfd80
[   18.118518] fba0: ffff800033fbfbe0 ffff0000009d4244 ffff800030b5fc00 ffff800030b5f038
[   18.126332] fbc0: ffff800033fbfbd0 ffff800030b5fc00 ffff800030b5f038 ffff0000009d4840
[   18.134144] fbe0: ffff800033fbfbf0 ffff0000009d4858 ffff800033fbfc10 ffff0000009d48e4
[   18.141955] fc00: ffff800030b5fc00 ffff8000338ffd98 ffff800033fbfc30 ffff0000009d49a4
[   18.149768] fc20: ffff800030b5fc00 ffff800030b5f000 ffff800033fbfc60 ffff0000009d4a4c
[   18.157581] fc40: ffff800030b5f050 ffff800030b5f000 0000000000000001 ffff800030b5fc00
[   18.165394] fc60: ffff800033fbfca0 ffff0000009d4ab0 0000000000000018 ffff800030b5f000
[   18.173206] fc80: ffff0000009efd28 ffff800033fbfd80 ffff8000338ff800 ffff0000009d56a8
[   18.181019] fca0: ffff800033fbfcb0 ffff0000009efd54 ffff800033fbfcc0 ffff0000009d56c8
[   18.188831] fcc0: ffff800033fbfd00 ffff0000009d58e0 ffff0000009fa6e0 00000000c00464b4
[   18.196643] fce0: 0000000000000004 ffff80003082b400 0000ffffea1f0e00 0000000000000000
[   18.204456] fd00: ffff800033fbfe00 ffff000008206f0c ffff80000335caf8 ffff80003082b400
[   18.212269] fd20: 0000ffffea1f0e00 ffff80003082b400 00000000c00464b4 0000ffffea1f0e00
[   18.220081] fd40: 0000000000000124 000000000000001d ffff0000089d2000 ffff800031236c00
[   18.227894] fd60: ffff800033fbfd80 0000000000000004 ffff0000009efd28 ffff800033fbfd80
[   18.235706] fd80: 0000000100000001 0000008000000001 0000001800000020 0000000000000001
[   18.243518] fda0: 0000000100000000 0000000100000001 0000ffff00000000 0000ffff00000000
[   18.251331] fdc0: 0000000000000124 0000000000000038 ffff0000089d2000 ffff800031236c00
[   18.259144] fde0: ffff800033fbfe40 ffff000008214124 ffff800033fbfe30 ffff000008203290
[   18.266956] fe00: ffff800033fbfe80 ffff0000082076b4 0000000000000000 ffff800030d8a000
[   18.274768] fe20: ffff80003082b400 0000000000000016 ffff800033fbfe50 ffff0000081f0488
[   18.282581] fe40: ffff800033fbfe80 ffff000008207678 0000000000000000 ffff80003082b400
[   18.290393] fe60: ffff800033fbfe70 ffff0000082138b0 ffff800033fbfe80 ffff000008207658
[   18.298207] fe80: 0000000000000000 ffff000008082f84 0000000000000000 0000800034a16000
[   18.306017] fea0: ffffffffffffffff 0000ffffb3347e7c 0000000000000000 0000000000000015
[   18.313832] fec0: 0000000000000016 00000000c00464b4 0000ffffea1f0e00 0000000000000001
[   18.321643] fee0: 0000000000000020 0000000000000080 0000000000000001 0000000000000000
[   18.329456] ff00: 000000000000001d 000000012692c5b0 0101010101010101 7f7f7f7f7f7f7f7f
[   18.337269] ff20: 0101010101010101 0000000000000038 0000000000000000 0000000000000053
[   18.345082] ff40: 0000ffffb368b2b8 0000ffffb3347e70 0000000000000000 0000ffffb3847000
[   18.352894] ff60: 0000ffffea1f0e00 00000000c00464b4 0000000000000016 0000ffffea1f0edc
[   18.360705] ff80: 000000012692ad20 0000000000000003 00000001214282e4 0000000121428388
[   18.368518] ffa0: 0000000000000000 0000ffffea1f0da0 0000ffffb367185c 0000ffffea1f0da0
[   18.376332] ffc0: 0000ffffb3347e7c 0000000000000000 0000000000000016 000000000000001d
[   18.384142] ffe0: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
[   18.391953] Call trace:
[   18.399760] Exception stack(0xffff800033fbf950 to 0xffff800033fbfa80)
[   18.402023] f940:                                   ffff80003082bf00 0001000000000000
[   18.408622] f960: ffff800033fbfb30 ffff000000ac2d58 0000000020000145 ffff8000338ffa78
[   18.416435] f980: 0000000000000000 0000000000000000 ffff800033fbf9e0 ffff0000089afcf0
[   18.424248] f9a0: ffff80000348f230 ffff8000338ffa78 0000000000000000 0000000000000000
[   18.432060] f9c0: ffff8000338ffaa8 0000000000000001 ffff800033fbfb80 ffff0000009e8f38
[   18.439872] f9e0: ffff800033fbfa10 ffff0000089a9ff8 0000000000000027 ffff80003082b918
[   18.447684] fa00: 0000000000000000 ffff80003082bf00 ffff8000337bf300 0000000000000000
[   18.455497] fa20: 00000000b5c01000 0000000000000000 0000000000000000 ffff800031657b78
[   18.463310] fa40: ffff800031657b50 ffff800030b5f038 0000000000000040 7f7f7f7f7f7f7f7f
[   18.471122] fa60: 0101010101010101 0000000000000038 0000000000000000 0000000000000053
[   18.479062] [<ffff000000ac2d58>] msm_gem_unmap_vma+0x20/0x80 [msm]
[   18.486862] [<ffff000000ac07c8>] put_iova+0x60/0xb8 [msm]
[   18.492938] [<ffff000000ac16b0>] msm_gem_free_object+0x60/0x198 [msm]
[   18.498432] [<ffff0000009d4244>] drm_gem_object_free+0x1c/0x58 [drm]
[   18.504854] [<ffff0000009d4858>] drm_gem_object_put_unlocked+0x90/0xa0 [drm]
[   18.511273] [<ffff0000009d48e4>] drm_gem_object_handle_put_unlocked+0x64/0xd0 [drm]
[   18.518300] [<ffff0000009d49a4>] drm_gem_object_release_handle+0x54/0x98 [drm]
[   18.525679] [<ffff0000009d4a4c>] drm_gem_handle_delete+0x64/0xb8 [drm]
[   18.532968] [<ffff0000009d4ab0>] drm_gem_dumb_destroy+0x10/0x18 [drm]
[   18.539479] [<ffff0000009efd54>] drm_mode_destroy_dumb_ioctl+0x2c/0x40 [drm]
[   18.545992] [<ffff0000009d56c8>] drm_ioctl_kernel+0x68/0xe0 [drm]
[   18.553105] [<ffff0000009d58e0>] drm_ioctl+0x178/0x3b0 [drm]
[   18.558970] [<ffff000008206f0c>] do_vfs_ioctl+0xa4/0x7d0
[   18.564694] [<ffff0000082076b4>] SyS_ioctl+0x7c/0x98
[   18.569992] [<ffff000008082f84>] el0_svc_naked+0x38/0x3c
[   18.574941] Code: a90153f3 aa0003f4 f90013f5 aa0103f3 (f9407400)
[   18.580502] ---[ end trace b1ac6888ec40b0be ]---

It turns out that the aspace argument in msm_gem_unmap_vma() is NULL.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
[Note: this case gets hit with !IOMMU config]
Signed-off-by: Rob Clark <robdclark@gmail.com>
philmmanjaro pushed a commit to philmmanjaro/linux-bfq that referenced this pull request Aug 15, 2017
syzkaller was able to trigger a divide by 0 in TCP stack [1]

Issue here is that keepalive timer needs to be updated to not attempt
to send a probe if the connection setup was deferred using
TCP_FASTOPEN_CONNECT socket option added in linux-4.11

[1]
 divide error: 0000 [linusw#1] SMP
 CPU: 18 PID: 0 Comm: swapper/18 Not tainted
 task: ffff986f62f4b040 ti: ffff986f62fa2000 task.ti: ffff986f62fa2000
 RIP: 0010:[<ffffffff8409cc0d>]  [<ffffffff8409cc0d>] __tcp_select_window+0x8d/0x160
 Call Trace:
  <IRQ>
  [<ffffffff8409d951>] tcp_transmit_skb+0x11/0x20
  [<ffffffff8409da21>] tcp_xmit_probe_skb+0xc1/0xe0
  [<ffffffff840a0ee8>] tcp_write_wakeup+0x68/0x160
  [<ffffffff840a151b>] tcp_keepalive_timer+0x17b/0x230
  [<ffffffff83b3f799>] call_timer_fn+0x39/0xf0
  [<ffffffff83b40797>] run_timer_softirq+0x1d7/0x280
  [<ffffffff83a04ddb>] __do_softirq+0xcb/0x257
  [<ffffffff83ae03ac>] irq_exit+0x9c/0xb0
  [<ffffffff83a04c1a>] smp_apic_timer_interrupt+0x6a/0x80
  [<ffffffff83a03eaf>] apic_timer_interrupt+0x7f/0x90
  <EOI>
  [<ffffffff83fed2ea>] ? cpuidle_enter_state+0x13a/0x3b0
  [<ffffffff83fed2cd>] ? cpuidle_enter_state+0x11d/0x3b0

Tested:

Following packetdrill no longer crashes the kernel

`echo 0 >/proc/sys/net/ipv4/tcp_timestamps`

// Cache warmup: send a Fast Open cookie request
    0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
   +0 fcntl(3, F_SETFL, O_RDWR|O_NONBLOCK) = 0
   +0 setsockopt(3, SOL_TCP, TCP_FASTOPEN_CONNECT, [1], 4) = 0
   +0 connect(3, ..., ...) = -1 EINPROGRESS (Operation is now in progress)
   +0 > S 0:0(0) <mss 1460,nop,nop,sackOK,nop,wscale 8,FO,nop,nop>
 +.01 < S. 123:123(0) ack 1 win 14600 <mss 1460,nop,nop,sackOK,nop,wscale 6,FO abcd1234,nop,nop>
   +0 > . 1:1(0) ack 1
   +0 close(3) = 0
   +0 > F. 1:1(0) ack 1
   +0 < F. 1:1(0) ack 2 win 92
   +0 > .  2:2(0) ack 2

   +0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 4
   +0 fcntl(4, F_SETFL, O_RDWR|O_NONBLOCK) = 0
   +0 setsockopt(4, SOL_TCP, TCP_FASTOPEN_CONNECT, [1], 4) = 0
   +0 setsockopt(4, SOL_SOCKET, SO_KEEPALIVE, [1], 4) = 0
 +.01 connect(4, ..., ...) = 0
   +0 setsockopt(4, SOL_TCP, TCP_KEEPIDLE, [5], 4) = 0
   +10 close(4) = 0

`echo 1 >/proc/sys/net/ipv4/tcp_timestamps`

Fixes: 19f6d3f ("net/tcp-fastopen: Add new API support")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Wei Wang <weiwan@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
philmmanjaro pushed a commit to philmmanjaro/linux-bfq that referenced this pull request Aug 15, 2017
This reverts commit bc4f65e.

As reported by Andreas, this commit is causing unrecoverable SLB misses in the
system call exit path:

  Unrecoverable exception 4100 at c00000000000a1ec
  Oops: Unrecoverable exception, sig: 6 [linusw#1]
  SMP NR_CPUS=2 PowerMac
  ...
  CPU: 0 PID: 18626 Comm: rm Not tainted 4.13.0-rc3 linusw#1
  task: c00000018335e080 task.stack: c000000139e50000
  NIP: c00000000000a1ec LR: c00000000000a118 CTR: 0000000000000000
  REGS: c000000139e53bb0 TRAP: 4100   Not tainted  (4.13.0-rc3)
  MSR: 9000000000001030 <SF,HV,ME,IR,DR> CR: 24000044  XER: 20000000 SOFTE: 1
  GPR00: 0000000000000000 c000000139e53e30 c000000000abb500 fffffffffffffffe
  GPR04: c0000001eb866298 0000000000000000 0000000000000000 c00000018335e080
  GPR08: 900000000000d032 0000000000000000 0000000000000002 fffffffffffff001
  GPR12: c000000139e50000 c00000000ffff000 00003fffa8c0dca0 00003fffa8c0dc88
  GPR16: 0000000010000000 0000000000000001 00003fffa8c0eaa0 0000000000000000
  GPR20: 00003fffa8c27528 00003fffa8c27b00 0000000000000000 0000000000000000
  GPR24: 00003fffa8c0d918 00003ffff1b3efa0 00003fffa8c26d68 0000000000000000
  GPR28: 00003fffa8c249e8 00003fffa8c263d0 00003fffa8c27550 00003ffff1b3ef10
  NIP [c00000000000a1ec] system_call_exit+0xc0/0x21c
  LR [c00000000000a118] system_call+0x58/0x6c
  Call Trace:
  [c000000139e53e30] [c00000000000a118] system_call+0x58/0x6c (unreliable)
  Instruction dump:
  64a51000 7c6300d0 f8a101a0 4bffff9c 3c000000 60000006 780007c6 64000000
  60000000 7c004039 4082001c e8ed0170 <88070b78> 88c70b79 7c003214 2c200000

This is caused by us trying to load THREAD_LOAD_FP with MSR_RI=0, and taking an
SLB miss on the thread struct.

Reported-by: Andreas Schwab <schwab@linux-m68k.org>
Diagnosed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
philmmanjaro pushed a commit to philmmanjaro/linux-bfq that referenced this pull request Aug 15, 2017
Dean Jenkins says:

====================
asix: Improve robustness

Please consider taking these patches to improve the robustness of the ASIX USB
to Ethernet driver.

Failures prompting an ASIX driver code review
=============================================

On an ARM i.MX6 embedded platform some strange one-off and two-off failures were
observed in and around the ASIX USB to Ethernet driver. This was observed on a
highly modified kernel 3.14 with the ASIX driver containing back-ported changes
from kernel.org up to kernel 4.8 approximately.

a) A one-off failure in asix_rx_fixup_internal():

There was an occurrence of an attempt to write off the end of the netdev buffer
which was trapped by skb_over_panic() in skb_put().

[20030.846440] skbuff: skb_over_panic: text:7f2271c0 len:120 put:60 head:8366ecc0 data:8366ed02 tail:0x8366ed7a end:0x8366ed40 dev:eth0
[20030.863007] Kernel BUG at 8044ce38 [verbose debug info unavailable]

[20031.215345] Backtrace:
[20031.217884] [<8044cde0>] (skb_panic) from [<8044d50c>] (skb_put+0x50/0x5c)
[20031.227408] [<8044d4bc>] (skb_put) from [<7f2271c0>] (asix_rx_fixup_internal+0x1c4/0x23c [asix])
[20031.242024] [<7f226ffc>] (asix_rx_fixup_internal [asix]) from [<7f22724c>] (asix_rx_fixup_common+0x14/0x18 [asix])
[20031.260309] [<7f227238>] (asix_rx_fixup_common [asix]) from [<7f21f7d4>] (usbnet_bh+0x74/0x224 [usbnet])
[20031.269879] [<7f21f760>] (usbnet_bh [usbnet]) from [<8002f834>] (call_timer_fn+0xa4/0x1f0)
[20031.283961] [<8002f790>] (call_timer_fn) from [<80030834>] (run_timer_softirq+0x230/0x2a8)
[20031.302782] [<80030604>] (run_timer_softirq) from [<80028780>] (__do_softirq+0x15c/0x37c)
[20031.321511] [<80028624>] (__do_softirq) from [<80028c38>] (irq_exit+0x8c/0xe8)
[20031.339298] [<80028bac>] (irq_exit) from [<8000e9c8>] (handle_IRQ+0x8c/0xc8)
[20031.350038] [<8000e93c>] (handle_IRQ) from [<800085c8>] (gic_handle_irq+0xb8/0xf8)
[20031.365528] [<80008510>] (gic_handle_irq) from [<8050de80>] (__irq_svc+0x40/0x70)

Analysis of the logic of the ASIX driver (containing backported changes from
kernel.org up to kernel 4.8 approximately) suggested that the software could not
trigger skb_over_panic(). The analysis of the kernel BUG() crash information
suggested that the netdev buffer was written with 2 minimal 60 octet length
Ethernet frames (ASIX hardware drops the 4 octet FCS field) and the 2nd Ethernet
frame attempted to write off the end of the netdev buffer.

Note that the netdev buffer should only contain 1 Ethernet frame so if an
attempt to write 2 Ethernet frames into the buffer is made then that is wrong.
However, the logic of the asix_rx_fixup_internal() only allows 1 Ethernet frame
to be written into the netdev buffer.

Potentially this failure was due to memory corruption because it was only seen
once.

b) Two-off failures in the NAPI layer's backlog queue:

There were 2 crashes in the NAPI layer's backlog queue presumably after
asix_rx_fixup_internal() called usbnet_skb_return().

[24097.273945] Unable to handle kernel NULL pointer dereference at virtual address 00000004

[24097.398944] PC is at process_backlog+0x80/0x16c

[24097.569466] Backtrace:
[24097.572007] [<8045ad98>] (process_backlog) from [<8045b64c>] (net_rx_action+0xcc/0x248)
[24097.591631] [<8045b580>] (net_rx_action) from [<80028780>] (__do_softirq+0x15c/0x37c)
[24097.610022] [<80028624>] (__do_softirq) from [<800289cc>] (run_ksoftirqd+0x2c/0x84)

and

[ 1059.828452] Unable to handle kernel NULL pointer dereference at virtual address 00000000

[ 1059.953715] PC is at process_backlog+0x84/0x16c

[ 1060.140896] Backtrace:
[ 1060.143434] [<8045ad98>] (process_backlog) from [<8045b64c>] (net_rx_action+0xcc/0x248)
[ 1060.163075] [<8045b580>] (net_rx_action) from [<80028780>] (__do_softirq+0x15c/0x37c)
[ 1060.181474] [<80028624>] (__do_softirq) from [<80028c38>] (irq_exit+0x8c/0xe8)
[ 1060.199256] [<80028bac>] (irq_exit) from [<8000e9c8>] (handle_IRQ+0x8c/0xc8)
[ 1060.210006] [<8000e93c>] (handle_IRQ) from [<800085c8>] (gic_handle_irq+0xb8/0xf8)
[ 1060.225492] [<80008510>] (gic_handle_irq) from [<8050de80>] (__irq_svc+0x40/0x70)

The embedded board was only using an ASIX USB to Ethernet adaptor eth0.

Analysis suggested that the doubly-linked list pointers of the backlog queue had
been corrupted because one of the link pointers was NULL.

Potentially this failure was due to memory corruption because it was only seen
twice.

Results of the ASIX driver code review
======================================

During the code review some weaknesses were observed in the ASIX driver and the
following patches have been created to improve the robustness.

Brief overview of the patches
-----------------------------

1. asix: Add rx->ax_skb = NULL after usbnet_skb_return()

The current ASIX driver sends the received Ethernet frame to the NAPI layer of
the network stack via the call to usbnet_skb_return() in
asix_rx_fixup_internal() but retains the rx->ax_skb pointer to the netdev
buffer. The driver no longer needs the rx->ax_skb pointer at this point because
the NAPI layer now has the Ethernet frame.

This means that asix_rx_fixup_internal() must not use rx->ax_skb after the call
to usbnet_skb_return() because it could corrupt the handling of the Ethernet
frame within the network layer.

Therefore, to remove the risk of erroneous usage of rx->ax_skb, set rx->ax_skb
to NULL after the call to usbnet_skb_return(). This avoids potential erroneous
freeing of rx->ax_skb and erroneous writing to the netdev buffer.  If the
software now somehow inappropriately reused rx->ax_skb, then a NULL pointer
dereference of rx->ax_skb would occur which makes investigation easier.

2. asix: Ensure asix_rx_fixup_info members are all reset

This patch creates reset_asix_rx_fixup_info() to allow all the
asix_rx_fixup_info structure members to be consistently reset to initial
conditions.

Call reset_asix_rx_fixup_info() upon each detectable error condition so that the
next URB is processed from a known state.

Otherwise, there is a risk that some members of the asix_rx_fixup_info structure
may be incorrect after an error occurred so potentially leading to a
malfunction.

3. asix: Fix small memory leak in ax88772_unbind()

This patch creates asix_rx_fixup_common_free() to allow the rx->ax_skb to be
freed when necessary.

asix_rx_fixup_common_free() is called from ax88772_unbind() before the parent
private data structure is freed.

Without this patch, there is a risk of a small netdev buffer memory leak each
time ax88772_unbind() is called during the reception of an Ethernet frame that
spans across 2 URBs.

Testing
=======

The patches have been sanity tested on a 64-bit Linux laptop running kernel
4.13-rc2 with the 3 patches applied on top.

The ASIX USB to Adaptor used for testing was (output of lsusb):
ID 0b95:772b ASIX Electronics Corp. AX88772B

Test linusw#1
-------

The test ran a flood ping test script which slowly incremented the ICMP Echo
Request's payload from 0 to 5000 octets. This eventually causes IPv4
fragmentation to occur which causes Ethernet frames to be sent very close to
each other so increases the probability that an Ethernet frame will span 2 URBs.
The test showed that all pings were successful. The test took about 15 minutes
to complete.

Test #2
-------

A script was run on the laptop to periodically run ifdown and ifup every second
so that the ASIX USB to Adaptor was up for 1 second and down for 1 second.

From a Linux PC connected to the laptop, the following ping command was used
ping -f -s 5000 <ip address of laptop>

The large ICMP payload causes IPv4 fragmentation resulting in multiple
Ethernet frames per original IP packet.

Kernel debug within the ASIX driver was enabled to see whether any ASIX errors
were generated. The test was run for about 24 hours and no ASIX errors were
seen.

Patches
=======

The 3 patches have been rebased off the net-next repo master branch with HEAD
fbbeefd net: fec: Allow reception of frames bigger than 1522 bytes
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
philmmanjaro pushed a commit to philmmanjaro/linux-bfq that referenced this pull request Aug 15, 2017
qmi_wwan_disconnect is called twice when disconnecting devices with
separate control and data interfaces.  The first invocation will set
the interface data to NULL for both interfaces to flag that the
disconnect has been handled.  But the matching NULL check was left
out when qmi_wwan_disconnect was added, resulting in this oops:

  usb 2-1.4: USB disconnect, device number 4
  qmi_wwan 2-1.4:1.6 wwp0s29u1u4i6: unregister 'qmi_wwan' usb-0000:00:1d.0-1.4, WWAN/QMI device
  BUG: unable to handle kernel NULL pointer dereference at 00000000000000e0
  IP: qmi_wwan_disconnect+0x25/0xc0 [qmi_wwan]
  PGD 0
  P4D 0
  Oops: 0000 [linusw#1] SMP
  Modules linked in: <stripped irrelevant module list>
  CPU: 2 PID: 33 Comm: kworker/2:1 Tainted: G            E   4.12.3-nr44-normandy-r1500619820+ linusw#1
  Hardware name: LENOVO 4291LR7/4291LR7, BIOS CBET4000 4.6-810-g50522254fb 07/21/2017
  Workqueue: usb_hub_wq hub_event [usbcore]
  task: ffff8c882b716040 task.stack: ffffb8e800d84000
  RIP: 0010:qmi_wwan_disconnect+0x25/0xc0 [qmi_wwan]
  RSP: 0018:ffffb8e800d87b38 EFLAGS: 00010246
  RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
  RDX: 0000000000000001 RSI: ffff8c8824f3f1d0 RDI: ffff8c8824ef6400
  RBP: ffff8c8824ef6400 R08: 0000000000000000 R09: 0000000000000000
  R10: ffffb8e800d87780 R11: 0000000000000011 R12: ffffffffc07ea0e8
  R13: ffff8c8824e2e000 R14: ffff8c8824e2e098 R15: 0000000000000000
  FS:  0000000000000000(0000) GS:ffff8c8835300000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00000000000000e0 CR3: 0000000229ca5000 CR4: 00000000000406e0
  Call Trace:
   ? usb_unbind_interface+0x71/0x270 [usbcore]
   ? device_release_driver_internal+0x154/0x210
   ? qmi_wwan_unbind+0x6d/0xc0 [qmi_wwan]
   ? usbnet_disconnect+0x6c/0xf0 [usbnet]
   ? qmi_wwan_disconnect+0x87/0xc0 [qmi_wwan]
   ? usb_unbind_interface+0x71/0x270 [usbcore]
   ? device_release_driver_internal+0x154/0x210

Reported-and-tested-by: Nathaniel Roach <nroach44@gmail.com>
Fixes: c6adf77 ("net: usb: qmi_wwan: add qmap mux protocol support")
Cc: Daniele Palmas <dnlplm@gmail.com>
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>
philmmanjaro pushed a commit to philmmanjaro/linux-bfq that referenced this pull request Aug 15, 2017
Commit 65d8fc7 ("futex: Remove requirement for lock_page() in
get_futex_key()") removed an unnecessary lock_page() with the
side-effect that page->mapping needed to be treated very carefully.

Two defensive warnings were added in case any assumption was missed and
the first warning assumed a correct application would not alter a
mapping backing a futex key.  Since merging, it has not triggered for
any unexpected case but Mark Rutland reported the following bug
triggering due to the first warning.

  kernel BUG at kernel/futex.c:679!
  Internal error: Oops - BUG: 0 [linusw#1] PREEMPT SMP
  Modules linked in:
  CPU: 0 PID: 3695 Comm: syz-executor1 Not tainted 4.13.0-rc3-00020-g307fec773ba3 #3
  Hardware name: linux,dummy-virt (DT)
  task: ffff80001e271780 task.stack: ffff000010908000
  PC is at get_futex_key+0x6a4/0xcf0 kernel/futex.c:679
  LR is at get_futex_key+0x6a4/0xcf0 kernel/futex.c:679
  pc : [<ffff00000821ac14>] lr : [<ffff00000821ac14>] pstate: 80000145

The fact that it's a bug instead of a warning was due to an unrelated
arm64 problem, but the warning itself triggered because the underlying
mapping changed.

This is an application issue but from a kernel perspective it's a
recoverable situation and the warning is unnecessary so this patch
removes the warning.  The warning may potentially be triggered with the
following test program from Mark although it may be necessary to adjust
NR_FUTEX_THREADS to be a value smaller than the number of CPUs in the
system.

    #include <linux/futex.h>
    #include <pthread.h>
    #include <stdio.h>
    #include <stdlib.h>
    #include <sys/mman.h>
    #include <sys/syscall.h>
    #include <sys/time.h>
    #include <unistd.h>

    #define NR_FUTEX_THREADS 16
    pthread_t threads[NR_FUTEX_THREADS];

    void *mem;

    #define MEM_PROT  (PROT_READ | PROT_WRITE)
    #define MEM_SIZE  65536

    static int futex_wrapper(int *uaddr, int op, int val,
                             const struct timespec *timeout,
                             int *uaddr2, int val3)
    {
        syscall(SYS_futex, uaddr, op, val, timeout, uaddr2, val3);
    }

    void *poll_futex(void *unused)
    {
        for (;;) {
            futex_wrapper(mem, FUTEX_CMP_REQUEUE_PI, 1, NULL, mem + 4, 1);
        }
    }

    int main(int argc, char *argv[])
    {
        int i;

        mem = mmap(NULL, MEM_SIZE, MEM_PROT,
               MAP_SHARED | MAP_ANONYMOUS, -1, 0);

        printf("Mapping @ %p\n", mem);

        printf("Creating futex threads...\n");

        for (i = 0; i < NR_FUTEX_THREADS; i++)
            pthread_create(&threads[i], NULL, poll_futex, NULL);

        printf("Flipping mapping...\n");
        for (;;) {
            mmap(mem, MEM_SIZE, MEM_PROT,
                 MAP_FIXED | MAP_SHARED | MAP_ANONYMOUS, -1, 0);
        }

        return 0;
    }

Reported-and-tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org # 4.7+
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
philmmanjaro pushed a commit to philmmanjaro/linux-bfq that referenced this pull request Aug 15, 2017
This patch fixes a generate_node_acls = 1 + cache_dynamic_acls = 0
regression, that was introduced by

  commit 01d4d67
  Author: Nicholas Bellinger <nab@linux-iscsi.org>
  Date:   Wed Dec 7 12:55:54 2016 -0800

which originally had the proper list_del_init() usage, but was
dropped during list review as it was thought unnecessary by HCH.

However, list_del_init() usage is required during the special
generate_node_acls = 1 + cache_dynamic_acls = 0 case when
transport_free_session() does a list_del(&se_nacl->acl_list),
followed by target_complete_nacl() doing the same thing.

This was manifesting as a general protection fault as reported
by Justin:

kernel: general protection fault: 0000 [linusw#1] SMP
kernel: Modules linked in:
kernel: CPU: 0 PID: 11047 Comm: iscsi_ttx Not tainted 4.13.0-rc2.x86_64.1+ #20
kernel: Hardware name: Intel Corporation S5500BC/S5500BC, BIOS S5500.86B.01.00.0064.050520141428 05/05/2014
kernel: task: ffff88026939e800 task.stack: ffffc90007884000
kernel: RIP: 0010:target_put_nacl+0x49/0xb0
kernel: RSP: 0018:ffffc90007887d70 EFLAGS: 00010246
kernel: RAX: dead000000000200 RBX: ffff8802556ca000 RCX: 0000000000000000
kernel: RDX: dead000000000100 RSI: 0000000000000246 RDI: ffff8802556ce028
kernel: RBP: ffffc90007887d88 R08: 0000000000000001 R09: 0000000000000000
kernel: R10: ffffc90007887df8 R11: ffffea0009986900 R12: ffff8802556ce020
kernel: R13: ffff8802556ce028 R14: ffff8802556ce028 R15: ffffffff88d85540
kernel: FS:  0000000000000000(0000) GS:ffff88027fc00000(0000) knlGS:0000000000000000
kernel: CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
kernel: CR2: 00007fffe36f5f94 CR3: 0000000009209000 CR4: 00000000003406f0
kernel: DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
kernel: DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
kernel: Call Trace:
kernel:  transport_free_session+0x67/0x140
kernel:  transport_deregister_session+0x7a/0xc0
kernel:  iscsit_close_session+0x92/0x210
kernel:  iscsit_close_connection+0x5f9/0x840
kernel:  iscsit_take_action_for_connection_exit+0xfe/0x110
kernel:  iscsi_target_tx_thread+0x140/0x1e0
kernel:  ? wait_woken+0x90/0x90
kernel:  kthread+0x124/0x160
kernel:  ? iscsit_thread_get_cpumask+0x90/0x90
kernel:  ? kthread_create_on_node+0x40/0x40
kernel:  ret_from_fork+0x22/0x30
kernel: Code: 00 48 89 fb 4c 8b a7 48 01 00 00 74 68 4d 8d 6c 24 08 4c
89 ef e8 e8 28 43 00 48 8b 93 20 04 00 00 48 8b 83 28 04 00 00 4c 89
ef <48> 89 42 08 48 89 10 48 b8 00 01 00 00 00 00 ad de 48 89 83 20
kernel: RIP: target_put_nacl+0x49/0xb0 RSP: ffffc90007887d70
kernel: ---[ end trace f12821adbfd46fed ]---

To address this, go ahead and use proper list_del_list() for all
cases of se_nacl->acl_list deletion.

Reported-by: Justin Maggard <jmaggard01@gmail.com>
Tested-by: Justin Maggard <jmaggard01@gmail.com>
Cc: Justin Maggard <jmaggard01@gmail.com>
Cc: stable@vger.kernel.org # 4.1+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
philmmanjaro pushed a commit to philmmanjaro/linux-bfq that referenced this pull request Aug 15, 2017
…r has

Some Alpine Ridge LP DROMs (there might be others) erroneusly list more
ports than the controller actually has. Most probably because DROM of
the full Dual/Single port Thunderbolt controller was reused for LP
version. The current DROM parser does not check the upper bound thus it
leads to crash when sw->ports[] is accessed over bounds:

 BUG: unable to handle kernel NULL pointer dereference at 00000000000002ec
 IP: tb_drom_read+0x383/0x890 [thunderbolt]
 PGD 0
 P4D 0
 Oops: 0000 [linusw#1] SMP
 CPU: 3 PID: 12248 Comm: systemd-udevd Not tainted 4.13.0-rc1-next-20170719 linusw#1
 Hardware name: LENOVO 20HF000YGE/20HF000YGE, BIOS N1WET32W (1.11 ) 05/23/2017
 task: ffff8a293e4bcd80 task.stack: ffffa698027a8000
 RIP: 0010:tb_drom_read+0x383/0x890 [thunderbolt]
 RSP: 0018:ffffa698027ab990 EFLAGS: 00010246
 RAX: 0000000000000000 RBX: ffff8a2940af7800 RCX: 0000000000000000
 RDX: ffff8a2940ebb400 RSI: 0000000000000000 RDI: ffffa698027ab9a0
 RBP: ffffa698027ab9d0 R08: 0000000000000001 R09: 0000000000000002
 R10: ffff8a2940ebb5b0 R11: 0000000000000000 R12: ffff8a293bfa968c
 R13: 000000000000002c R14: 0000000000000056 R15: 0000000000000056
 FS:  00007f0a945a38c0(0000) GS:ffff8a2961580000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 00000000000002ec CR3: 000000043e785000 CR4: 00000000003606e0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 Call Trace:
  tb_switch_add+0x9d/0x730 [thunderbolt]
  ? tb_switch_alloc+0x3cd/0x4d0 [thunderbolt]
  icm_start+0x5a/0xa0 [thunderbolt]
  tb_domain_add+0xc3/0xf0 [thunderbolt]
  nhi_probe+0x19e/0x310 [thunderbolt]
  local_pci_probe+0x42/0xa0
  pci_device_probe+0x18d/0x1a0
  driver_probe_device+0x2ff/0x450
  __driver_attach+0xa4/0xe0
  ? driver_probe_device+0x450/0x450
  bus_for_each_dev+0x6e/0xb0
  driver_attach+0x1e/0x20
  bus_add_driver+0x1d0/0x270
  ? 0xffffffffc0bbb000
  driver_register+0x60/0xe0
  ? 0xffffffffc0bbb000
  __pci_register_driver+0x4c/0x50
  nhi_init+0x28/0x1000 [thunderbolt]
  do_one_initcall+0x50/0x190
  ? __vunmap+0x81/0xb0
  ? _cond_resched+0x1a/0x50
  ? kmem_cache_alloc_trace+0x15f/0x1c0
  ? do_init_module+0x27/0x1e9
  do_init_module+0x5f/0x1e9
  load_module+0x24e7/0x2a60
  ? vfs_read+0x115/0x130
  SYSC_finit_module+0xfc/0x120
  ? SYSC_finit_module+0xfc/0x120
  SyS_finit_module+0xe/0x10
  do_syscall_64+0x67/0x170
  entry_SYSCALL64_slow_path+0x25/0x25

Fix this by making sure we only enumerate DROM port entries the hardware
actually has.

Reported-by: Christian Kellner <ckellner@redhat.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Lukas Wunner <lukas@wunner.de>
Tested-by: Christian Kellner <ckellner@redhat.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
philmmanjaro pushed a commit to philmmanjaro/linux-bfq that referenced this pull request Aug 15, 2017
huge_add_to_page_cache->add_to_page_cache implicitly unlocks the page
before returning in case of errors.

The error returned was -EEXIST by running UFFDIO_COPY on a non-hole
offset of a VM_SHARED hugetlbfs mapping.  It was an userland bug that
triggered it and the kernel must cope with it returning -EEXIST from
ioctl(UFFDIO_COPY) as expected.

  page dumped because: VM_BUG_ON_PAGE(!PageLocked(page))
  kernel BUG at mm/filemap.c:964!
  invalid opcode: 0000 [linusw#1] SMP
  CPU: 1 PID: 22582 Comm: qemu-system-x86 Not tainted 4.11.11-300.fc26.x86_64 linusw#1
  RIP: unlock_page+0x4a/0x50
  Call Trace:
    hugetlb_mcopy_atomic_pte+0xc0/0x320
    mcopy_atomic+0x96f/0xbe0
    userfaultfd_ioctl+0x218/0xe90
    do_vfs_ioctl+0xa5/0x600
    SyS_ioctl+0x79/0x90
    entry_SYSCALL_64_fastpath+0x1a/0xa9

Link: http://lkml.kernel.org/r/20170802165145.22628-2-aarcange@redhat.com
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Tested-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Alexey Perevalov <a.perevalov@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
philmmanjaro pushed a commit to philmmanjaro/linux-bfq that referenced this pull request Aug 15, 2017
We saw many list corruption warnings on shmem shrinklist:

  WARNING: CPU: 18 PID: 177 at lib/list_debug.c:59 __list_del_entry+0x9e/0xc0
  list_del corruption. prev->next should be ffff9ae5694b82d8, but was ffff9ae5699ba960
  Modules linked in: intel_rapl sb_edac edac_core x86_pkg_temp_thermal coretemp iTCO_wdt iTCO_vendor_support crct10dif_pclmul crc32_pclmul ghash_clmulni_intel raid0 dcdbas shpchp wmi hed i2c_i801 ioatdma lpc_ich i2c_smbus acpi_cpufreq tcp_diag inet_diag sch_fq_codel ipmi_si ipmi_devintf ipmi_msghandler igb ptp crc32c_intel pps_core i2c_algo_bit i2c_core dca ipv6 crc_ccitt
  CPU: 18 PID: 177 Comm: kswapd1 Not tainted 4.9.34-t3.el7.twitter.x86_64 linusw#1
  Hardware name: Dell Inc. PowerEdge C6220/0W6W6G, BIOS 2.2.3 11/07/2013
  Call Trace:
    dump_stack+0x4d/0x66
    __warn+0xcb/0xf0
    warn_slowpath_fmt+0x4f/0x60
    __list_del_entry+0x9e/0xc0
    shmem_unused_huge_shrink+0xfa/0x2e0
    shmem_unused_huge_scan+0x20/0x30
    super_cache_scan+0x193/0x1a0
    shrink_slab.part.41+0x1e3/0x3f0
    shrink_slab+0x29/0x30
    shrink_node+0xf9/0x2f0
    kswapd+0x2d8/0x6c0
    kthread+0xd7/0xf0
    ret_from_fork+0x22/0x30

  WARNING: CPU: 23 PID: 639 at lib/list_debug.c:33 __list_add+0x89/0xb0
  list_add corruption. prev->next should be next (ffff9ae5699ba960), but was ffff9ae5694b82d8. (prev=ffff9ae5694b82d8).
  Modules linked in: intel_rapl sb_edac edac_core x86_pkg_temp_thermal coretemp iTCO_wdt iTCO_vendor_support crct10dif_pclmul crc32_pclmul ghash_clmulni_intel raid0 dcdbas shpchp wmi hed i2c_i801 ioatdma lpc_ich i2c_smbus acpi_cpufreq tcp_diag inet_diag sch_fq_codel ipmi_si ipmi_devintf ipmi_msghandler igb ptp crc32c_intel pps_core i2c_algo_bit i2c_core dca ipv6 crc_ccitt
  CPU: 23 PID: 639 Comm: systemd-udevd Tainted: G        W       4.9.34-t3.el7.twitter.x86_64 linusw#1
  Hardware name: Dell Inc. PowerEdge C6220/0W6W6G, BIOS 2.2.3 11/07/2013
  Call Trace:
    dump_stack+0x4d/0x66
    __warn+0xcb/0xf0
    warn_slowpath_fmt+0x4f/0x60
    __list_add+0x89/0xb0
    shmem_setattr+0x204/0x230
    notify_change+0x2ef/0x440
    do_truncate+0x5d/0x90
    path_openat+0x331/0x1190
    do_filp_open+0x7e/0xe0
    do_sys_open+0x123/0x200
    SyS_open+0x1e/0x20
    do_syscall_64+0x61/0x170
    entry_SYSCALL64_slow_path+0x25/0x25

The problem is that shmem_unused_huge_shrink() moves entries from the
global sbinfo->shrinklist to its local lists and then releases the
spinlock.  However, a parallel shmem_setattr() could access one of these
entries directly and add it back to the global shrinklist if it is
removed, with the spinlock held.

The logic itself looks solid since an entry could be either in a local
list or the global list, otherwise it is removed from one of them by
list_del_init().  So probably the race condition is that, one CPU is in
the middle of INIT_LIST_HEAD() but the other CPU calls list_empty()
which returns true too early then the following list_add_tail() sees a
corrupted entry.

list_empty_careful() is designed to fix this situation.

[akpm@linux-foundation.org: add comments]
Link: http://lkml.kernel.org/r/20170803054630.18775-1-xiyou.wangcong@gmail.com
Fixes: 779750d ("shmem: split huge pages beyond i_size under memory pressure")
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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