CPUs which are affected by L1TF and MDS mitigate MDS with the L1D Flush on
VMENTER when updated microcode is installed.

If a CPU is not affected by L1TF or if the L1D Flush is not in use, then
MDS mitigation needs to be invoked explicitly.

For these cases, follow the host mitigation state and invoke the MDS
mitigation before VMENTER.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Jon Masters <jcm@redhat.com>
Tested-by: Jon Masters <jcm@redhat.com>

Add a static key which controls the invocation of the CPU buffer clear
mechanism on exit to user space and add the call into
prepare_exit_to_usermode() and do_nmi() right before actually returning.

Add documentation which kernel to user space transition this covers and
explain why some corner cases are not mitigated.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Jon Masters <jcm@redhat.com>
Tested-by: Jon Masters <jcm@redhat.com>

The Microarchitectural Data Sampling (MDS) vulernabilities are mitigated by
clearing the affected CPU buffers. The mechanism for clearing the buffers
uses the unused and obsolete VERW instruction in combination with a
microcode update which triggers a CPU buffer clear when VERW is executed.

Provide a inline function with the assembly magic. The argument of the VERW
instruction must be a memory operand as documented:

  "MD_CLEAR enumerates that the memory-operand variant of VERW (for
   example, VERW m16) has been extended to also overwrite buffers affected
   by MDS. This buffer overwriting functionality is not guaranteed for the
   register operand variant of VERW."

Documentation also recommends to use a writable data segment selector:

  "The buffer overwriting occurs regardless of the result of the VERW
   permission check, as well as when the selector is null or causes a
   descriptor load segment violation. However, for lowest latency we
   recommend using a selector that indicates a valid writable data
   segment."

Add x86 specific documentation about MDS and the internal workings of the
mitigation.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Jon Masters <jcm@redhat.com>
Tested-by: Jon Masters <jcm@redhat.com>

X86_FEATURE_MD_CLEAR is a new CPUID bit which is set when microcode
provides the mechanism to invoke a flush of various exploitable CPU buffers
by invoking the VERW instruction.

Hand it through to guests so they can adjust their mitigations.

This also requires corresponding qemu changes, which are available
separately.

[ tglx: Massaged changelog ]
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Jon Masters <jcm@redhat.com>
Tested-by: Jon Masters <jcm@redhat.com>

This bug bit is set on CPUs which are only affected by Microarchitectural
Store Buffer Data Sampling (MSBDS) and not by any other MDS variant.

This is important because the Store Buffers are partitioned between
Hyper-Threads so cross thread forwarding is not possible. But if a thread
enters or exits a sleep state the store buffer is repartitioned which can
expose data from one thread to the other. This transition can be mitigated.

That means that for CPUs which are only affected by MSBDS SMT can be
enabled, if the CPU is not affected by other SMT sensitive vulnerabilities,
e.g. L1TF. The XEON PHI variants fall into that category. Also the
Silvermont/Airmont ATOMs, but for them it's not really relevant as they do
not support SMT, but mark them for completeness sake.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Jon Masters <jcm@redhat.com>
Tested-by: Jon Masters <jcm@redhat.com>

Microarchitectural Data Sampling (MDS), is a class of side channel attacks
on internal buffers in Intel CPUs. The variants are:

 - Microarchitectural Store Buffer Data Sampling (MSBDS) (CVE-2018-12126)
 - Microarchitectural Fill Buffer Data Sampling (MFBDS) (CVE-2018-12130)
 - Microarchitectural Load Port Data Sampling (MLPDS) (CVE-2018-12127)

MSBDS leaks Store Buffer Entries which can be speculatively forwarded to a
dependent load (store-to-load forwarding) as an optimization. The forward
can also happen to a faulting or assisting load operation for a different
memory address, which can be exploited under certain conditions. Store
buffers are partitioned between Hyper-Threads so cross thread forwarding is
not possible. But if a thread enters or exits a sleep state the store
buffer is repartitioned which can expose data from one thread to the other.

MFBDS leaks Fill Buffer Entries. Fill buffers are used internally to manage
L1 miss situations and to hold data which is returned or sent in response
to a memory or I/O operation. Fill buffers can forward data to a load
operation and also write data to the cache. When the fill buffer is
deallocated it can retain the stale data of the preceding operations which
can then be forwarded to a faulting or assisting load operation, which can
be exploited under certain conditions. Fill buffers are shared between
Hyper-Threads so cross thread leakage is possible.

MLDPS leaks Load Port Data. Load ports are used to perform load operations
from memory or I/O. The received data is then forwarded to the register
file or a subsequent operation. In some implementations the Load Port can
contain stale data from a previous operation which can be forwarded to
faulting or assisting loads under certain conditions, which again can be
exploited eventually. Load ports are shared between Hyper-Threads so cross
thread leakage is possible.

All variants have the same mitigation for single CPU thread case (SMT off),
so the kernel can treat them as one MDS issue.

Add the basic infrastructure to detect if the current CPU is affected by
MDS.

[ tglx: Rewrote changelog ]
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Jon Masters <jcm@redhat.com>
Tested-by: Jon Masters <jcm@redhat.com>

The CPU vulnerability whitelists have some overlap and there are more
whitelists coming along.

Use the driver_data field in the x86_cpu_id struct to denote the
whitelisted vulnerabilities and combine all whitelists into one.
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Jon Masters <jcm@redhat.com>
Tested-by: Jon Masters <jcm@redhat.com>

Greg pointed out that speculation related bit defines are using (1 << N)
format instead of BIT(N). Aside of that (1 << N) is wrong as it should use
1UL at least.

Clean it up.

[ Josh Poimboeuf: Fix tools build ]
Reported-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Jon Masters <jcm@redhat.com>
Tested-by: Jon Masters <jcm@redhat.com>

Pull ARM SoC fixes from Arnd Bergmann:
 "One more set of simple ARM platform fixes:

   - A boot regression on qualcomm msm8998

   - Gemini display controllers got turned off by accident

   - incorrect reference counting in optee"

* tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc:
  tee: optee: add missing of_node_put after of_device_is_available
  arm64: dts: qcom: msm8998: Extend TZ reserved memory area
  ARM: dts: gemini: Re-enable display controller

Pull x86 fixes from Thomas Gleixner:
 "Two last minute fixes:

   - Prevent value evaluation via functions happening in the user access
     enabled region of __put_user() (put another way: make sure to
     evaluate the value to be stored in user space _before_ enabling
     user space accesses)

   - Correct the definition of a Hyper-V hypercall constant"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/hyper-v: Fix definition of HV_MAX_FLUSH_REP_COUNT
  x86/uaccess: Don't leak the AC flag into __put_user() value evaluation

Pull SCSI fixes from James Bottomley:
 "Nine small fixes.

  The resume fix is a cosmetic removal of a warning with an incorrect
  condition causing it to alarm people wrongly.

  The other eight patches correct a thinko in Christoph Hellwig's DMA
  conversion series. Without it all these drivers end up with 32 bit DMA
  masks meaning they bounce any page over 4GB before sending it to the
  controller.

  Nowadays, even laptops mostly have memory above 4GB, so this can lead
  to significant performance degradation with all the bouncing"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: core: Avoid that system resume triggers a kernel warning
  scsi: hptiop: fix calls to dma_set_mask()
  scsi: hisi_sas: fix calls to dma_set_mask_and_coherent()
  scsi: csiostor: fix calls to dma_set_mask_and_coherent()
  scsi: bfa: fix calls to dma_set_mask_and_coherent()
  scsi: aic94xx: fix calls to dma_set_mask_and_coherent()
  scsi: 3w-sas: fix calls to dma_set_mask_and_coherent()
  scsi: 3w-9xxx: fix calls to dma_set_mask_and_coherent()
  scsi: lpfc: fix calls to dma_set_mask_and_coherent()

Pull networking fixes from David Miller:

 1) Fix refcount leak in act_ipt during replace, from Davide Caratti.

 2) Set task state properly in tun during blocking reads, from Timur
    Celik.

 3) Leaked reference in DSA, from Wen Yang.

 4) NULL deref in act_tunnel_key, from Vlad Buslov.

 5) cipso_v4_erro can reference the skb IPCB in inappropriate contexts
    thus referencing garbage, from Nazarov Sergey.

 6) Don't accept RTA_VIA and RTA_GATEWAY in contexts where those
    attributes make no sense.

 7) Fix hung sendto in tipc, from Tung Nguyen.

 8) Out-of-bounds access in netlabel, from Paul Moore.

 9) Grant reference leak in xen-netback, from Igor Druzhinin.

10) Fix tx stalls with lan743x, from Bryan Whitehead.

11) Fix interrupt storm with mv88e6xxx, from Hein Kallweit.

12) Memory leak in sit on device registry failure, from Mao Wenan.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (44 commits)
  net: sit: fix memory leak in sit_init_net()
  net: dsa: mv88e6xxx: Fix statistics on mv88e6161
  geneve: correctly handle ipv6.disable module parameter
  net: dsa: mv88e6xxx: prevent interrupt storm caused by mv88e6390x_port_set_cmode
  bpf: fix sanitation rewrite in case of non-pointers
  ipv4: Add ICMPv6 support when parse route ipproto
  MIPS: eBPF: Fix icache flush end address
  lan743x: Fix TX Stall Issue
  net: phy: phylink: fix uninitialized variable in phylink_get_mac_state
  net: aquantia: regression on cpus with high cores: set mode with 8 queues
  selftests: fixes for UDP GRO
  bpf: drop refcount if bpf_map_new_fd() fails in map_create()
  net: dsa: mv88e6xxx: power serdes on/off for 10G interfaces on 6390X
  net: dsa: mv88e6xxx: Fix u64 statistics
  xen-netback: don't populate the hash cache on XenBus disconnect
  xen-netback: fix occasional leak of grant ref mappings under memory pressure
  sctp: chunk.c: correct format string for size_t in printk
  net: netem: fix skb length BUG_ON in __skb_to_sgvec
  netlabel: fix out-of-bounds memory accesses
  ipv4: Pass original device to ip_rcv_finish_core
  ...

Pull more crypto fixes from Herbert Xu:
 "This fixes a couple of issues in arm64/chacha that was introduced in
  5.0"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: arm64/chacha - fix hchacha_block_neon() for big endian
  crypto: arm64/chacha - fix chacha_4block_xor_neon() for big endian

If register_netdev() is failed to register sitn->fb_tunnel_dev,
it will go to err_reg_dev and forget to free netdev(sitn->fb_tunnel_dev).

BUG: memory leak
unreferenced object 0xffff888378daad00 (size 512):
  comm "syz-executor.1", pid 4006, jiffies 4295121142 (age 16.115s)
  hex dump (first 32 bytes):
    00 e6 ed c0 83 88 ff ff 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
backtrace:
    [<00000000d6dcb63e>] kvmalloc include/linux/mm.h:577 [inline]
    [<00000000d6dcb63e>] kvzalloc include/linux/mm.h:585 [inline]
    [<00000000d6dcb63e>] netif_alloc_netdev_queues net/core/dev.c:8380 [inline]
    [<00000000d6dcb63e>] alloc_netdev_mqs+0x600/0xcc0 net/core/dev.c:8970
    [<00000000867e172f>] sit_init_net+0x295/0xa40 net/ipv6/sit.c:1848
    [<00000000871019fa>] ops_init+0xad/0x3e0 net/core/net_namespace.c:129
    [<00000000319507f6>] setup_net+0x2ba/0x690 net/core/net_namespace.c:314
    [<0000000087db4f96>] copy_net_ns+0x1dc/0x330 net/core/net_namespace.c:437
    [<0000000057efc651>] create_new_namespaces+0x382/0x730 kernel/nsproxy.c:107
    [<00000000676f83de>] copy_namespaces+0x2ed/0x3d0 kernel/nsproxy.c:165
    [<0000000030b74bac>] copy_process.part.27+0x231e/0x6db0 kernel/fork.c:1919
    [<00000000fff78746>] copy_process kernel/fork.c:1713 [inline]
    [<00000000fff78746>] _do_fork+0x1bc/0xe90 kernel/fork.c:2224
    [<000000001c2e0d1c>] do_syscall_64+0xc8/0x580 arch/x86/entry/common.c:290
    [<00000000ec48bd44>] entry_SYSCALL_64_after_hwframe+0x49/0xbe
    [<0000000039acff8a>] 0xffffffffffffffff
Signed-off-by: Mao Wenan <maowenan@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Despite what the datesheet says, the silicon implements the older way
of snapshoting the statistics. Change the op.

Reported-by: Chris.Healy@zii.aero
Tested-by: Chris.Healy@zii.aero
Fixes: 0ac64c39 ("net: dsa: mv88e6xxx: mv88e6161 uses mv88e6320 stats snapshot")
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

When IPv6 is compiled but disabled at runtime, geneve_sock_add returns
-EAFNOSUPPORT. For metadata based tunnels, this causes failure of the whole
operation of bringing up the tunnel.

Ignore failure of IPv6 socket creation for metadata based tunnels caused by
IPv6 not being available.

This is the same fix as what commit d074bf96 ("vxlan: correctly handle
ipv6.disable module parameter") is doing for vxlan.

Note there's also commit c0a47e44 ("geneve: should not call rt6_lookup()
when ipv6 was disabled") which fixes a similar issue but for regular
tunnels, while this patch is needed for metadata based tunnels.
Signed-off-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Alexei Starovoitov says:

====================
pull-request: bpf 2019-03-01

The following pull-request contains BPF updates for your *net* tree.

The main changes are:

1) fix sanitation rewrite, from Daniel.

2) fix error path on map_new_fd, from Peng.

3) fix icache flush address, from Paul.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

When debugging another issue I faced an interrupt storm in this
driver (88E6390, port 9 in SGMII mode), consisting of alternating
link-up / link-down interrupts. Analysis showed that the driver
wanted to set a cmode that was set already. But so far
mv88e6390x_port_set_cmode() doesn't check this and powers down
SERDES, what causes the link to break, and eventually results in
the described interrupt storm.

Fix this by checking whether the cmode actually changes. We want
that the very first call to mv88e6390x_port_set_cmode() always
configures the registers, therefore initialize port.cmode with
a value that is different from any supported cmode value.
We have to take care that we only init the ports cmode once
chip->info->num_ports is set.

v2:
- add small helper and init the number of actual ports only

Fixes: 364e9d77 ("net: dsa: mv88e6xxx: Power on/off SERDES on cmode change")
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Marek reported that he saw an issue with the below snippet in that
timing measurements where off when loaded as unpriv while results
were reasonable when loaded as privileged:

    [...]
    uint64_t a = bpf_ktime_get_ns();
    uint64_t b = bpf_ktime_get_ns();
    uint64_t delta = b - a;
    if ((int64_t)delta > 0) {
    [...]

Turns out there is a bug where a corner case is missing in the fix
d3bd7413 ("bpf: fix sanitation of alu op with pointer / scalar
type from different paths"), namely fixup_bpf_calls() only checks
whether aux has a non-zero alu_state, but it also needs to test for
the case of BPF_ALU_NON_POINTER since in both occasions we need to
skip the masking rewrite (as there is nothing to mask).

Fixes: d3bd7413 ("bpf: fix sanitation of alu op with pointer / scalar type from different paths")
Reported-by: Marek Majkowski <marek@cloudflare.com>
Reported-by: Arthur Fabre <afabre@cloudflare.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/netdev/CAJPywTJqP34cK20iLM5YmUMz9KXQOdu1-+BZrGMAGgLuBWz7fg@mail.gmail.com/T/Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

For ip rules, we need to use 'ipproto ipv6-icmp' to match ICMPv6 headers.
But for ip -6 route, currently we only support tcp, udp and icmp.

Add ICMPv6 support so we can match ipv6-icmp rules for route lookup.

v2: As David Ahern and Sabrina Dubroca suggested, Add an argument to
rtm_getroute_parse_ip_proto() to handle ICMP/ICMPv6 with different family.
Reported-by: Jianlin Shi <jishi@redhat.com>
Fixes: eacb9384 ("ipv6: support sport, dport and ip_proto in RTM_GETROUTE")
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The MIPS eBPF JIT calls flush_icache_range() in order to ensure the
icache observes the code that we just wrote. Unfortunately it gets the
end address calculation wrong due to some bad pointer arithmetic.

The struct jit_ctx target field is of type pointer to u32, and as such
adding one to it will increment the address being pointed to by 4 bytes.
Therefore in order to find the address of the end of the code we simply
need to add the number of 4 byte instructions emitted, but we mistakenly
add the number of instructions multiplied by 4. This results in the call
to flush_icache_range() operating on a memory region 4x larger than
intended, which is always wasteful and can cause crashes if we overrun
into an unmapped page.

Fix this by correcting the pointer arithmetic to remove the bogus
multiplication, and use braces to remove the need for a set of brackets
whilst also making it obvious that the target field is a pointer.
Signed-off-by: Paul Burton <paul.burton@mips.com>
Fixes: b6bd53f9 ("MIPS: Add missing file for eBPF JIT.")
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Yonghong Song <yhs@fb.com>
Cc: netdev@vger.kernel.org
Cc: bpf@vger.kernel.org
Cc: linux-mips@vger.kernel.org
Cc: stable@vger.kernel.org # v4.13+
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

It has been observed that tx queue stalls while downloading
from certain web sites (example www.speedtest.net)

The cause has been tracked down to a corner case where
dma descriptors where not setup properly. And there for a tx
completion interrupt was not signaled.

This fix corrects the problem by properly marking the end of
a multi descriptor transmission.

Fixes: 23f0703c ("lan743x: Add main source files for new lan743x driver")
Signed-off-by: Bryan Whitehead <Bryan.Whitehead@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When debugging an issue I found implausible values in state->pause.
Reason in that state->pause isn't initialized and later only single
bits are changed. Also the struct itself isn't initialized in
phylink_resolve(). So better initialize state->pause and other
not yet initialized fields.

v2:
- use right function name in subject
v3:
- initialize additional fields

Fixes: 9525ae83 ("phylink: add phylink infrastructure")
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Recently the maximum number of queues was increased up to 8, but
NIC was not fully configured for 8 queues. In setups with more than 4 CPU
cores parts of TX traffic gets lost if the kernel routes it to queues 4th-8th.

This patch sets a tx hw traffic mode with 8 queues.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=202651

Fixes: 71a963cf ("net: aquantia: increase max number of hw queues")
Reported-by: Nicholas Johnson <nicholas.johnson@outlook.com.au>
Signed-off-by: Dmitry Bogdanov <dmitry.bogdanov@aquantia.com>
Signed-off-by: Igor Russkikh <igor.russkikh@aquantia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The current implementation for UDP GRO tests is racy: the receiver
may flush the RX queue while the sending is still transmitting and
incorrectly report RX errors, with a wrong number of packet received.

Add explicit timeouts to the receiver for both connection activation
(first packet received for UDP) and reception completion, so that
in the above critical scenario the receiver will wait for the
transfer completion.

Fixes: 3327a9c4 ("selftests: add functionals test for UDP GRO")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pull IOMMU fix from Joerg Roedel:
 "One important fix for a memory corruption issue in the Intel VT-d
  driver that triggers on hardware with deep PCI hierarchies"

* tag 'iommu-fix-v5.0-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
  iommu/dmar: Fix buffer overflow during PCI bus notification

Merge misc fixes from Andrew Morton:
 "2 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  hugetlbfs: fix races and page leaks during migration
  kasan: turn off asan-stack for clang-8 and earlier

hugetlb pages should only be migrated if they are 'active'.  The
routines set/clear_page_huge_active() modify the active state of hugetlb
pages.

When a new hugetlb page is allocated at fault time, set_page_huge_active
is called before the page is locked.  Therefore, another thread could
race and migrate the page while it is being added to page table by the
fault code.  This race is somewhat hard to trigger, but can be seen by
strategically adding udelay to simulate worst case scheduling behavior.
Depending on 'how' the code races, various BUG()s could be triggered.

To address this issue, simply delay the set_page_huge_active call until
after the page is successfully added to the page table.

Hugetlb pages can also be leaked at migration time if the pages are
associated with a file in an explicitly mounted hugetlbfs filesystem.
For example, consider a two node system with 4GB worth of huge pages
available.  A program mmaps a 2G file in a hugetlbfs filesystem.  It
then migrates the pages associated with the file from one node to
another.  When the program exits, huge page counts are as follows:

  node0
  1024    free_hugepages
  1024    nr_hugepages

  node1
  0       free_hugepages
  1024    nr_hugepages

  Filesystem                         Size  Used Avail Use% Mounted on
  nodev                              4.0G  2.0G  2.0G  50% /var/opt/hugepool

That is as expected.  2G of huge pages are taken from the free_hugepages
counts, and 2G is the size of the file in the explicitly mounted
filesystem.  If the file is then removed, the counts become:

  node0
  1024    free_hugepages
  1024    nr_hugepages

  node1
  1024    free_hugepages
  1024    nr_hugepages

  Filesystem                         Size  Used Avail Use% Mounted on
  nodev                              4.0G  2.0G  2.0G  50% /var/opt/hugepool

Note that the filesystem still shows 2G of pages used, while there
actually are no huge pages in use.  The only way to 'fix' the filesystem
accounting is to unmount the filesystem

If a hugetlb page is associated with an explicitly mounted filesystem,
this information in contained in the page_private field.  At migration
time, this information is not preserved.  To fix, simply transfer
page_private from old to new page at migration time if necessary.

There is a related race with removing a huge page from a file and
migration.  When a huge page is removed from the pagecache, the
page_mapping() field is cleared, yet page_private remains set until the
page is actually freed by free_huge_page().  A page could be migrated
while in this state.  However, since page_mapping() is not set the
hugetlbfs specific routine to transfer page_private is not called and we
leak the page count in the filesystem.

To fix that, check for this condition before migrating a huge page.  If
the condition is detected, return EBUSY for the page.

Link: http://lkml.kernel.org/r/74510272-7319-7372-9ea6-ec914734c179@oracle.com
Link: http://lkml.kernel.org/r/20190212221400.3512-1-mike.kravetz@oracle.com
Fixes: bcc54222 ("mm: hugetlb: introduce page_huge_active")
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: <stable@vger.kernel.org>
[mike.kravetz@oracle.com: v2]
  Link: http://lkml.kernel.org/r/7534d322-d782-8ac6-1c8d-a8dc380eb3ab@oracle.com
[mike.kravetz@oracle.com: update comment and changelog]
  Link: http://lkml.kernel.org/r/420bcfd6-158b-38e4-98da-26d0cd85bd01@oracle.comSigned-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Building an arm64 allmodconfig kernel with clang results in over 140
warnings about overly large stack frames, the worst ones being:

  drivers/gpu/drm/panel/panel-sitronix-st7789v.c:196:12: error: stack frame size of 20224 bytes in function 'st7789v_prepare'
  drivers/video/fbdev/omap2/omapfb/displays/panel-tpo-td028ttec1.c:196:12: error: stack frame size of 13120 bytes in function 'td028ttec1_panel_enable'
  drivers/usb/host/max3421-hcd.c:1395:1: error: stack frame size of 10048 bytes in function 'max3421_spi_thread'
  drivers/net/wan/slic_ds26522.c:209:12: error: stack frame size of 9664 bytes in function 'slic_ds26522_probe'
  drivers/crypto/ccp/ccp-ops.c:2434:5: error: stack frame size of 8832 bytes in function 'ccp_run_cmd'
  drivers/media/dvb-frontends/stv0367.c:1005:12: error: stack frame size of 7840 bytes in function 'stv0367ter_algo'

None of these happen with gcc today, and almost all of these are the
result of a single known issue in llvm.  Hopefully it will eventually
get fixed with the clang-9 release.

In the meantime, the best idea I have is to turn off asan-stack for
clang-8 and earlier, so we can produce a kernel that is safe to run.

I have posted three patches that address the frame overflow warnings
that are not addressed by turning off asan-stack, so in combination with
this change, we get much closer to a clean allmodconfig build, which in
turn is necessary to do meaningful build regression testing.

It is still possible to turn on the CONFIG_ASAN_STACK option on all
versions of clang, and it's always enabled for gcc, but when
CONFIG_COMPILE_TEST is set, the option remains invisible, so
allmodconfig and randconfig builds (which are normally done with a
forced CONFIG_COMPILE_TEST) will still result in a mostly clean build.

Link: http://lkml.kernel.org/r/20190222222950.3997333-1-arnd@arndb.de
Link: https://bugs.llvm.org/show_bug.cgi?id=38809Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Qian Cai <cai@lca.pw>
Reviewed-by: Mark Brown <broonie@kernel.org>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Kostya Serebryany <kcc@google.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull drm fixes from Dave Airlie:
 "Three final fixes, one for a feature that is new in this kernel, one
  bochs fix for qemu riscv and one atomic modesetting fix.

  I've left a few of the other late fixes until next as I didn't want to
  throw in anything that wasn't really necessary"

* tag 'drm-fixes-2019-03-01' of git://anongit.freedesktop.org/drm/drm:
  drm/bochs: Fix the ID mismatch error
  drm: Block fb changes for async plane updates
  drm/amd/display: Use vrr friendly pageflip throttling in DC.

In bpf/syscall.c, map_create() first set map->usercnt to 1, a file
descriptor is supposed to return to userspace. When bpf_map_new_fd()
fails, drop the refcount.

Fixes: bd5f5f4e ("bpf: Add BPF_MAP_GET_FD_BY_ID")
Signed-off-by: Peng Sun <sironhide0null@gmail.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Merge tag 'qcom-fixes-for-5.0-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/agross/linux into arm/fixes

Qualcomm ARM64 Fixes for 5.0-rc8

* Fix TZ memory area size to avoid crashes during boot

* tag 'qcom-fixes-for-5.0-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/agross/linux:
  arm64: dts: qcom: msm8998: Extend TZ reserved memory area

Merge tag 'tee-fix-for-v5.0' of https://git.linaro.org/people/jens.wiklander/linux-tee into arm/fixes

OP-TEE driver
- add missing of_node_put after of_device_is_available

* tag 'tee-fix-for-v5.0' of https://git.linaro.org/people/jens.wiklander/linux-tee:
  tee: optee: add missing of_node_put after of_device_is_available

Pull MIPS fixes from Paul Burton:
 "A few more MIPS fixes:

   - Fix 16b cmpxchg() operations which could erroneously fail if bits
     15:8 of the old value are non-zero. In practice I'm not aware of
     any actual users of 16b cmpxchg() on MIPS, but this fixes the
     support for it was was introduced in v4.13.

   - Provide a struct device to dma_alloc_coherent for Lantiq XWAY
     systems with a "Voice MIPS Macro Core" (VMMC) device.

   - Provide DMA masks for BCM63xx ethernet devices, fixing a regression
     introduced in v4.19.

   - Fix memblock reservation for the kernel when the system has a
     non-zero PHYS_OFFSET, correcting the memblock conversion performed
     in v4.20"

* tag 'mips_fixes_5.0_4' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux:
  MIPS: fix memory setup for platforms with PHYS_OFFSET != 0
  MIPS: BCM63XX: provide DMA masks for ethernet devices
  MIPS: lantiq: pass struct device to DMA API functions
  MIPS: fix truncation in __cmpxchg_small for short values

Pull orangefs fixlet from Mike Marshall:
 "Remove two un-needed BUG_ONs"

* tag 'for-linus-5.0-ofs1' of git://git.kernel.org/pub/scm/linux/kernel/git/hubcap/linux:
  orangefs: remove two un-needed BUG_ONs...

Upon setting the cmode on 6390 and 6390X, the associated serdes
interfaces must be powered off/on.

Both 6390X and 6390 share code to do so, but it currently uses the 6390
specific helper mv88e6390_serdes_power() to disable and enable the
serdes interface.

This call will fail silently on 6390X when trying so set a 10G interface
such as XAUI or RXAUI, since mv88e6390_serdes_power() internally grabs
the lane number based on modes supported by the 6390, and returns 0 when
getting -ENODEV as a lane number.

Using mv88e6390x_serdes_power() should be safe here, since we explicitly
rule-out all ports but the 9 and 10, and because modes supported by 6390
ports 9 and 10 are a subset of those supported on 6390X.

This was tested on 6390X using RXAUI mode.

Fixes: 364e9d77 ("net: dsa: mv88e6xxx: Power on/off SERDES on cmode change")
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

The switch maintains u64 counters for the number of octets sent and
received. These are kept as two u32's which need to be combined.  Fix
the combing, which wrongly worked on u16's.

Fixes: 80c4627b ("dsa: mv88x6xxx: Refactor getting a single statistic")
Reported-by: Chris Healy <Chris.Healy@zii.aero>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

Occasionally, during the disconnection procedure on XenBus which
includes hash cache deinitialization there might be some packets
still in-flight on other processors. Handling of these packets includes
hashing and hash cache population that finally results in hash cache
data structure corruption.

In order to avoid this we prevent hashing of those packets if there
are no queues initialized. In that case RCU protection of queues guards
the hash cache as well.
Signed-off-by: Igor Druzhinin <igor.druzhinin@citrix.com>
Reviewed-by: Paul Durrant <paul.durrant@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Zero-copy callback flag is not yet set on frag list skb at the moment
xenvif_handle_frag_list() returns -ENOMEM. This eventually results in
leaking grant ref mappings since xenvif_zerocopy_callback() is never
called for these fragments. Those eventually build up and cause Xen
to kill Dom0 as the slots get reused for new mappings:

"d0v0 Attempt to implicitly unmap a granted PTE c010000329fce005"

That behavior is observed under certain workloads where sudden spikes
of page cache writes coexist with active atomic skb allocations from
network traffic. Additionally, rework the logic to deal with frag_list
deallocation in a single place.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Signed-off-by: Igor Druzhinin <igor.druzhinin@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>