Until this point vmx.c has been the only consumer and included the
file after many others.  Prepare for multiple consumers, i.e. the
shattering of vmx.c
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

...to prepare for the creation of a "vmx" subdirectory that will contain
a variety of headers.  Clean things up now to avoid making a bigger mess
in the future.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

...and make enable_shadow_vmcs depend on nested.  Aside from the obvious
memory savings, this will allow moving the relevant code out of vmx.c in
the future, e.g. to a nested specific file.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Fixes: 34a1cd60 ("kvm: x86: vmx: move some vmx setting from vmx_init() to hardware_setup()")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

There are two problems with KVM_GET_DIRTY_LOG.  First, and less important,
it can take kvm->mmu_lock for an extended period of time.  Second, its user
can actually see many false positives in some cases.  The latter is due
to a benign race like this:

  1. KVM_GET_DIRTY_LOG returns a set of dirty pages and write protects
     them.
  2. The guest modifies the pages, causing them to be marked ditry.
  3. Userspace actually copies the pages.
  4. KVM_GET_DIRTY_LOG returns those pages as dirty again, even though
     they were not written to since (3).

This is especially a problem for large guests, where the time between
(1) and (3) can be substantial.  This patch introduces a new
capability which, when enabled, makes KVM_GET_DIRTY_LOG not
write-protect the pages it returns.  Instead, userspace has to
explicitly clear the dirty log bits just before using the content
of the page.  The new KVM_CLEAR_DIRTY_LOG ioctl can also operate on a
64-page granularity rather than requiring to sync a full memslot;
this way, the mmu_lock is taken for small amounts of time, and
only a small amount of time will pass between write protection
of pages and the sending of their content.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

When manual dirty log reprotect will be enabled, kvm_get_dirty_log_protect's
pointer argument will always be false on exit, because no TLB flush is needed
until the manual re-protection operation.  Rename it from "is_dirty" to "flush",
which more accurately tells the caller what they have to do with it.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

The first such capability to be handled in virt/kvm/ will be manual
dirty page reprotection.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Merge branch 'khdr_fix' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest into HEAD

Merge topic branch from Shuah.

Commit b2d35fa5 ("selftests: add headers_install to lib.mk") added
khdr target to run headers_install target from the main Makefile. The
logic uses KSFT_KHDR_INSTALL and top_srcdir as controls to initialize
variables and include files to run headers_install from the top level
Makefile. There are a few problems with this logic.

1. Exposes top_srcdir to all tests
2. Common logic impacts all tests
3. Uses KSFT_KHDR_INSTALL, top_srcdir, and khdr in an adhoc way. Tests
   add "khdr" dependency in their Makefiles to TEST_PROGS_EXTENDED in
   some cases, and STATIC_LIBS in other cases. This makes this framework
   confusing to use.

The common logic that runs for all tests even when KSFT_KHDR_INSTALL
isn't defined by the test. top_srcdir is initialized to a default value
when test doesn't initialize it. It works for all tests without a sub-dir
structure and tests with sub-dir structure fail to build.

e.g: make -C sparc64/drivers/ or make -C drivers/dma-buf

../../lib.mk:20: ../../../../scripts/subarch.include: No such file or directory
make: *** No rule to make target '../../../../scripts/subarch.include'.  Stop.

There is no reason to require all tests to define top_srcdir and there is
no need to require tests to add khdr dependency using adhoc changes to
TEST_* and other variables.

Fix it with a consistent use of KSFT_KHDR_INSTALL and top_srcdir from tests
that have the dependency on headers_install.

Change common logic to include khdr target define and "all" target with
dependency on khdr when KSFT_KHDR_INSTALL is defined.

Only tests that have dependency on headers_install have to define just
the KSFT_KHDR_INSTALL, and top_srcdir variables and there is no need to
specify khdr dependency in the test Makefiles.

Fixes: b2d35fa5 ("selftests: add headers_install to lib.mk")
Cc: stable@vger.kernel.org
Signed-off-by: Shuah Khan <shuah@kernel.org>

Pull networking fixes from David Miller:
 "A decent batch of fixes here. I'd say about half are for problems that
  have existed for a while, and half are for new regressions added in
  the 4.20 merge window.

   1) Fix 10G SFP phy module detection in mvpp2, from Baruch Siach.

   2) Revert bogus emac driver change, from Benjamin Herrenschmidt.

   3) Handle BPF exported data structure with pointers when building
      32-bit userland, from Daniel Borkmann.

   4) Memory leak fix in act_police, from Davide Caratti.

   5) Check RX checksum offload in RX descriptors properly in aquantia
      driver, from Dmitry Bogdanov.

   6) SKB unlink fix in various spots, from Edward Cree.

   7) ndo_dflt_fdb_dump() only works with ethernet, enforce this, from
      Eric Dumazet.

   8) Fix FID leak in mlxsw driver, from Ido Schimmel.

   9) IOTLB locking fix in vhost, from Jean-Philippe Brucker.

  10) Fix SKB truesize accounting in ipv4/ipv6/netfilter frag memory
      limits otherwise namespace exit can hang. From Jiri Wiesner.

  11) Address block parsing length fixes in x25 from Martin Schiller.

  12) IRQ and ring accounting fixes in bnxt_en, from Michael Chan.

  13) For tun interfaces, only iface delete works with rtnl ops, enforce
      this by disallowing add. From Nicolas Dichtel.

  14) Use after free in liquidio, from Pan Bian.

  15) Fix SKB use after passing to netif_receive_skb(), from Prashant
      Bhole.

  16) Static key accounting and other fixes in XPS from Sabrina Dubroca.

  17) Partially initialized flow key passed to ip6_route_output(), from
      Shmulik Ladkani.

  18) Fix RTNL deadlock during reset in ibmvnic driver, from Thomas
      Falcon.

  19) Several small TCP fixes (off-by-one on window probe abort, NULL
      deref in tail loss probe, SNMP mis-estimations) from Yuchung
      Cheng"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (93 commits)
  net/sched: cls_flower: Reject duplicated rules also under skip_sw
  bnxt_en: Fix _bnxt_get_max_rings() for 57500 chips.
  bnxt_en: Fix NQ/CP rings accounting on the new 57500 chips.
  bnxt_en: Keep track of reserved IRQs.
  bnxt_en: Fix CNP CoS queue regression.
  net/mlx4_core: Correctly set PFC param if global pause is turned off.
  Revert "net/ibm/emac: wrong bit is used for STA control"
  neighbour: Avoid writing before skb->head in neigh_hh_output()
  ipv6: Check available headroom in ip6_xmit() even without options
  tcp: lack of available data can also cause TSO defer
  ipv6: sr: properly initialize flowi6 prior passing to ip6_route_output
  mlxsw: spectrum_switchdev: Fix VLAN device deletion via ioctl
  mlxsw: spectrum_router: Relax GRE decap matching check
  mlxsw: spectrum_switchdev: Avoid leaking FID's reference count
  mlxsw: spectrum_nve: Remove easily triggerable warnings
  ipv4: ipv6: netfilter: Adjust the frag mem limit when truesize changes
  sctp: frag_point sanity check
  tcp: fix NULL ref in tail loss probe
  tcp: Do not underestimate rwnd_limited
  net: use skb_list_del_init() to remove from RX sublists
  ...

Pull x86 fixes from Ingo Molnar:
 "Three fixes: a boot parameter re-(re-)fix, a retpoline build artifact
  fix and an LLVM workaround"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/vdso: Drop implicit common-page-size linker flag
  x86/build: Fix compiler support check for CONFIG_RETPOLINE
  x86/boot: Clear RSDP address in boot_params for broken loaders

Pull kprobes fixes from Ingo Molnar:
 "Two kprobes fixes: a blacklist fix and an instruction patching related
  corruption fix"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  kprobes/x86: Blacklist non-attachable interrupt functions
  kprobes/x86: Fix instruction patching corruption when copying more than one RIP-relative instruction

Pull EFI fixes from Ingo Molnar:
 "Two fixes: a large-system fix and an earlyprintk fix with certain
  resolutions"

* 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/earlyprintk/efi: Fix infinite loop on some screen widths
  x86/efi: Allocate e820 buffer before calling efi_exit_boot_service

Currently, duplicated rules are rejected only for skip_hw or "none",
hence allowing users to push duplicates into HW for no reason.

Use the flower tables to protect for that.
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Paul Blakey <paulb@mellanox.com>
Reported-by: Chris Mi <chrism@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Michael Chan says:

====================
bnxt_en: Bug fixes.

The first patch fixes a regression on CoS queue setup, introduced
recently by the 57500 new chip support patches.  The rest are
fixes related to ring and resource accounting on the new 57500 chips.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

The CP rings are accounted differently on the new 57500 chips.  There
must be enough CP rings for the sum of RX and TX rings on the new
chips.  The current logic may be over-estimating the RX and TX rings.

The output parameter max_cp should be the maximum NQs capped by
MSIX vectors available for networking in the context of 57500 chips.
The existing code which uses CMPL rings capped by the MSIX vectors
works most of the time but is not always correct.
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The new 57500 chips have introduced the NQ structure in addition to
the existing CP rings in all chips.  We need to introduce a new
bnxt_nq_rings_in_use().  On legacy chips, the 2 functions are the
same and one will just call the other.  On the new chips, they
refer to the 2 separate ring structures.  The new function is now
called to determine the resource (NQ or CP rings) associated with
MSIX that are in use.

On 57500 chips, the RDMA driver does not use the CP rings so
we don't need to do the subtraction adjustment.

Fixes: 41e8d798 ("bnxt_en: Modify the ring reservation functions for 57500 series chips.")
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The new 57500 chips use 1 NQ per MSIX vector, whereas legacy chips use
1 CP ring per MSIX vector.  To better unify this, add a resv_irqs
field to struct bnxt_hw_resc.  On legacy chips, we initialize resv_irqs
with resv_cp_rings.  On new chips, we initialize it with the allocated
MSIX resources.
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Recent changes to support the 57500 devices have created this
regression.  The bnxt_hwrm_queue_qportcfg() call was moved to be
called earlier before the RDMA support was determined, causing
the CoS queues configuration to be set before knowing whether RDMA
was supported or not.  Fix it by moving it to the right place right
after RDMA support is determined.

Fixes: 98f04cf0 ("bnxt_en: Check context memory requirements from firmware.")
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pull char/misc driver fixes from Greg KH:
 "Here are some small driver fixes for 4.20-rc6.

  There is a hyperv fix that for some reaon took forever to get into a
  shape that could be applied to the tree properly, but resolves a much
  reported issue. The others are some gnss patches, one a bugfix and the
  two others updates to the MAINTAINERS file to properly match the gnss
  files in the tree.

  All have been in linux-next for a while with no reported issues"

* tag 'char-misc-4.20-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  MAINTAINERS: exclude gnss from SIRFPRIMA2 regex matching
  MAINTAINERS: add gnss scm tree
  gnss: sirf: fix activation retry handling
  Drivers: hv: vmbus: Offload the handling of channels to two workqueues

Pull staging fixes from Greg KH:
 "Here are two staging driver bugfixes for 4.20-rc6.

  One is a revert of a previously incorrect patch that was merged a
  while ago, and the other resolves a possible buffer overrun that was
  found by code inspection.

  Both of these have been in the linux-next tree with no reported
  issues"

* tag 'staging-4.20-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  Revert commit ef9209b6 "staging: rtl8723bs: Fix indenting errors and an off-by-one mistake in core/rtw_mlme_ext.c"
  staging: rtl8712: Fix possible buffer overrun

Pull tty driver fixes from Greg KH:
 "Here are three small tty driver fixes for 4.20-rc6

  Nothing major, just some bug fixes for reported issues. Full details
  are in the shortlog.

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

* tag 'tty-4.20-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  kgdboc: fix KASAN global-out-of-bounds bug in param_set_kgdboc_var()
  tty: serial: 8250_mtk: always resume the device in probe.
  tty: do not set TTY_IO_ERROR flag if console port

Pull USB fixes from Greg KH:
 "Here are some small USB fixes for 4.20-rc6

  The "largest" here are some xhci fixes for reported issues. Also here
  is a USB core fix, some quirk additions, and a usb-serial fix which
  required the export of one of the tty layer's functions to prevent
  code duplication. The tty maintainer agreed with this change.

  All of these have been in linux-next with no reported issues"

* tag 'usb-4.20-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  xhci: Prevent U1/U2 link pm states if exit latency is too long
  xhci: workaround CSS timeout on AMD SNPS 3.0 xHC
  USB: check usb_get_extra_descriptor for proper size
  USB: serial: console: fix reported terminal settings
  usb: quirk: add no-LPM quirk on SanDisk Ultra Flair device
  USB: Fix invalid-free bug in port_over_current_notify()
  usb: appledisplay: Add 27" Apple Cinema Display

Pull cifs fixes from Steve French:
 "Three small fixes: a fix for smb3 direct i/o, a fix for CIFS DFS for
  stable and a minor cifs Kconfig fix"

* tag '4.20-rc5-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  CIFS: Avoid returning EBUSY to upper layer VFS
  cifs: Fix separator when building path from dentry
  cifs: In Kconfig CONFIG_CIFS_POSIX needs depends on legacy (insecure cifs)

Pull dax fixes from Dan Williams:
 "The last of the known regression fixes and fallout from the Xarray
  conversion of the filesystem-dax implementation.

  On the path to debugging why the dax memory-failure injection test
  started failing after the Xarray conversion a couple more fixes for
  the dax_lock_mapping_entry(), now called dax_lock_page(), surfaced.
  Those plus the bug that started the hunt are now addressed. These
  patches have appeared in a -next release with no issues reported.

  Note the touches to mm/memory-failure.c are just the conversion to the
  new function signature for dax_lock_page().

  Summary:

   - Fix the Xarray conversion of fsdax to properly handle
     dax_lock_mapping_entry() in the presense of pmd entries

   - Fix inode destruction racing a new lock request"

* tag 'dax-fixes-4.20-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  dax: Fix unlock mismatch with updated API
  dax: Don't access a freed inode
  dax: Check page->mapping isn't NULL

Pull libnvdimm fixes from Dan Williams:
 "A regression fix for the Address Range Scrub implementation, yes
  another one, and support for platforms that misalign persistent memory
  relative to the Linux memory hotplug section constraint. Longer term,
  support for sub-section memory hotplug would alleviate alignment
  waste, but until then this hack allows a 'struct page' memmap to be
  established for these misaligned memory regions.

  These have all appeared in a -next release, and thanks to Patrick for
  reporting and testing the alignment padding fix.

  Summary:

   - Unless and until the core mm handles memory hotplug units smaller
     than a section (128M), persistent memory namespaces must be padded
     to section alignment.

     The libnvdimm core already handled section collision with "System
     RAM", but some configurations overlap independent "Persistent
     Memory" ranges within a section, so additional padding injection is
     added for that case.

   - The recent reworks of the ARS (address range scrub) state machine
     to reduce the number of state flags inadvertantly missed a
     conversion of acpi_nfit_ars_rescan() call sites. Fix the regression
     whereby user-requested ARS results in a "short" scrub rather than a
     "long" scrub.

   - Fixup the unit tests to handle / test the 128M section alignment of
     mocked test resources.

* tag 'libnvdimm-fixes-4.20-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  acpi/nfit: Fix user-initiated ARS to be "ARS-long" rather than "ARS-short"
  libnvdimm, pfn: Pad pfn namespaces relative to other regions
  tools/testing/nvdimm: Align test resources to 128M

rx_ppp and tx_ppp can be set between 0 and 255, so don't clamp to 1.

Fixes: 6e8814ce ("net/mlx4_en: Fix mixed PFC and Global pause user control requests")
Signed-off-by: Tarick Bedeir <tarick@google.com>
Reviewed-by: Eran Ben Elisha <eranbe@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pull thermal SoC fixes from Eduardo Valentin:
 "Fixes for armada and broadcom thermal drivers"

* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/evalenti/linux-soc-thermal:
  thermal: broadcom: constify thermal_zone_of_device_ops structure
  thermal: armada: constify thermal_zone_of_device_ops structure
  thermal: bcm2835: Switch to SPDX identifier
  thermal: armada: fix legacy resource fixup
  thermal: armada: fix legacy validity test sense

Pull asm-generic fix from Arnd Bergmann:
 "Multiple people reported a bug I introduced in asm-generic/unistd.h in
  4.20, this is the obvious bugfix to get glibc and others to correctly
  build again on new architectures that no longer provide the old
  fstatat64() family of system calls"

* tag 'asm-generic-4.20' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
  asm-generic: unistd.h: fixup broken macro include.

Pull clk fixes from Stephen Boyd:
 "A few clk driver fixes this time:

   - Introduce protected-clock DT binding to fix breakage on qcom
     sdm845-mtp boards where the qspi clks introduced this merge window
     cause the firmware on those boards to take down the system if we
     try to read the clk registers

   - Fix a couple off-by-one errors found by Dan Carpenter

   - Handle failure in zynq fixed factor clk driver to avoid using
     uninitialized data"

* tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux:
  clk: zynqmp: Off by one in zynqmp_is_valid_clock()
  clk: mmp: Off by one in mmp_clk_add()
  clk: mvebu: Off by one bugs in cp110_of_clk_get()
  arm64: dts: qcom: sdm845-mtp: Mark protected gcc clocks
  clk: qcom: Support 'protected-clocks' property
  dt-bindings: clk: Introduce 'protected-clocks' property
  clk: zynqmp: handle fixed factor param query error

Pull xfs fixes from Darrick Wong:
 "Here are hopefully the last set of fixes for 4.20.

  There's a fix for a longstanding statfs reporting problem with project
  quotas, a correction for page cache invalidation behaviors when
  fallocating near EOF, and a fix for a broken metadata verifier return
  code.

  Finally, the most important fix is to the pipe splicing code (aka the
  generic copy_file_range fallback) to avoid pointless short directio
  reads by only asking the filesystem for as much data as there are
  available pages in the pipe buffer. Our previous fix (simulated short
  directio reads because the number of pages didn't match the length of
  the read requested) caused subtle problems on overlayfs, so that part
  is reverted.

  Anyhow, this series passes fstests -g all on xfs and overlay+xfs, and
  has passed 17 billion fsx operations problem-free since I started
  testing

  Summary:

   - Fix broken project quota inode counts

   - Fix incorrect PAGE_MASK/PAGE_SIZE usage

   - Fix incorrect return value in btree verifier

   - Fix WARN_ON remap flags false positive

   - Fix splice read overflows"

* tag 'xfs-4.20-fixes-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  iomap: partially revert 4721a601 (simulated directio short read on EFAULT)
  splice: don't read more than available pipe space
  vfs: allow some remap flags to be passed to vfs_clone_file_range
  xfs: fix inverted return from xfs_btree_sblock_verify_crc
  xfs: fix PAGE_MASK usage in xfs_free_file_space
  fs/xfs: fix f_ffree value for statfs when project quota is set

This reverts commit 89c83fb5.

This should have been done as part of 2f0799a0 ("mm, thp: restore
node-local hugepage allocations").  The movement of the thp allocation
policy from alloc_pages_vma() to alloc_hugepage_direct_gfpmask() was
intended to only set __GFP_THISNODE for mempolicies that are not
MPOL_BIND whereas the revert could set this regardless of mempolicy.

While the check for MPOL_BIND between alloc_hugepage_direct_gfpmask()
and alloc_pages_vma() was racy, that has since been removed since the
revert.  What is left is the possibility to use __GFP_THISNODE in
policy_node() when it is unexpected because the special handling for
hugepages in alloc_pages_vma()  was removed as part of the consolidation.

Secondly, prior to 89c83fb5, alloc_pages_vma() implemented a somewhat
different policy for hugepage allocations, which were allocated through
alloc_hugepage_vma().  For hugepage allocations, if the allocating
process's node is in the set of allowed nodes, allocate with
__GFP_THISNODE for that node (for MPOL_PREFERRED, use that node with
__GFP_THISNODE instead).  This was changed for shmem_alloc_hugepage() to
allow fallback to other nodes in 89c83fb5 as it did for new_page() in
mm/mempolicy.c which is functionally different behavior and removes the
requirement to only allocate hugepages locally.

So this commit does a full revert of 89c83fb5 instead of the partial
revert that was done in 2f0799a0.  The result is the same thp
allocation policy for 4.20 that was in 4.19.

Fixes: 89c83fb5 ("mm, thp: consolidate THP gfp handling into alloc_hugepage_direct_gfpmask")
Fixes: 2f0799a0 ("mm, thp: restore node-local hugepage allocations")
Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This reverts commit 624ca9c3.

This commit is completely bogus. The STACR register has two formats, old
and new, depending on the version of the IP block used. There's a pair of
device-tree properties that can be used to specify the format used:

	has-inverted-stacr-oc
	has-new-stacr-staopc

What this commit did was to change the bit definition used with the old
parts to match the new parts. This of course breaks the driver on all
the old ones.

Instead, the author should have set the appropriate properties in the
device-tree for the variant used on his board.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Stefano Brivio says:

====================
Fix slab out-of-bounds on insufficient headroom for IPv6 packets

Patch 1/2 fixes a slab out-of-bounds occurring with short SCTP packets over
IPv4 over L2TP over IPv6 on a configuration with relatively low HEADER_MAX.

Patch 2/2 makes sure we avoid writing before the allocated buffer in
neigh_hh_output() in case the headroom is enough for the unaligned hardware
header size, but not enough for the aligned one, and that we warn if we hit
this condition.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

While skb_push() makes the kernel panic if the skb headroom is less than
the unaligned hardware header size, it will proceed normally in case we
copy more than that because of alignment, and we'll silently corrupt
adjacent slabs.

In the case fixed by the previous patch,
"ipv6: Check available headroom in ip6_xmit() even without options", we
end up in neigh_hh_output() with 14 bytes headroom, 14 bytes hardware
header and write 16 bytes, starting 2 bytes before the allocated buffer.

Always check we're not writing before skb->head and, if the headroom is
not enough, warn and drop the packet.

v2:
 - instead of panicking with BUG_ON(), WARN_ON_ONCE() and drop the packet
   (Eric Dumazet)
 - if we avoid the panic, though, we need to explicitly check the headroom
   before the memcpy(), otherwise we'll have corrupted slabs on a running
   kernel, after we warn
 - use __skb_push() instead of skb_push(), as the headroom check is
   already implemented here explicitly (Eric Dumazet)
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Even if we send an IPv6 packet without options, MAX_HEADER might not be
enough to account for the additional headroom required by alignment of
hardware headers.

On a configuration without HYPERV_NET, WLAN, AX25, and with IPV6_TUNNEL,
sending short SCTP packets over IPv4 over L2TP over IPv6, we start with
100 bytes of allocated headroom in sctp_packet_transmit(), end up with 54
bytes after l2tp_xmit_skb(), and 14 bytes in ip6_finish_output2().

Those would be enough to append our 14 bytes header, but we're going to
align that to 16 bytes, and write 2 bytes out of the allocated slab in
neigh_hh_output().

KASan says:

[  264.967848] ==================================================================
[  264.967861] BUG: KASAN: slab-out-of-bounds in ip6_finish_output2+0x1aec/0x1c70
[  264.967866] Write of size 16 at addr 000000006af1c7fe by task netperf/6201
[  264.967870]
[  264.967876] CPU: 0 PID: 6201 Comm: netperf Not tainted 4.20.0-rc4+ #1
[  264.967881] Hardware name: IBM 2827 H43 400 (z/VM 6.4.0)
[  264.967887] Call Trace:
[  264.967896] ([<00000000001347d6>] show_stack+0x56/0xa0)
[  264.967903]  [<00000000017e379c>] dump_stack+0x23c/0x290
[  264.967912]  [<00000000007bc594>] print_address_description+0xf4/0x290
[  264.967919]  [<00000000007bc8fc>] kasan_report+0x13c/0x240
[  264.967927]  [<000000000162f5e4>] ip6_finish_output2+0x1aec/0x1c70
[  264.967935]  [<000000000163f890>] ip6_finish_output+0x430/0x7f0
[  264.967943]  [<000000000163fe44>] ip6_output+0x1f4/0x580
[  264.967953]  [<000000000163882a>] ip6_xmit+0xfea/0x1ce8
[  264.967963]  [<00000000017396e2>] inet6_csk_xmit+0x282/0x3f8
[  264.968033]  [<000003ff805fb0ba>] l2tp_xmit_skb+0xe02/0x13e0 [l2tp_core]
[  264.968037]  [<000003ff80631192>] l2tp_eth_dev_xmit+0xda/0x150 [l2tp_eth]
[  264.968041]  [<0000000001220020>] dev_hard_start_xmit+0x268/0x928
[  264.968069]  [<0000000001330e8e>] sch_direct_xmit+0x7ae/0x1350
[  264.968071]  [<000000000122359c>] __dev_queue_xmit+0x2b7c/0x3478
[  264.968075]  [<00000000013d2862>] ip_finish_output2+0xce2/0x11a0
[  264.968078]  [<00000000013d9b14>] ip_finish_output+0x56c/0x8c8
[  264.968081]  [<00000000013ddd1e>] ip_output+0x226/0x4c0
[  264.968083]  [<00000000013dbd6c>] __ip_queue_xmit+0x894/0x1938
[  264.968100]  [<000003ff80bc3a5c>] sctp_packet_transmit+0x29d4/0x3648 [sctp]
[  264.968116]  [<000003ff80b7bf68>] sctp_outq_flush_ctrl.constprop.5+0x8d0/0xe50 [sctp]
[  264.968131]  [<000003ff80b7c716>] sctp_outq_flush+0x22e/0x7d8 [sctp]
[  264.968146]  [<000003ff80b35c68>] sctp_cmd_interpreter.isra.16+0x530/0x6800 [sctp]
[  264.968161]  [<000003ff80b3410a>] sctp_do_sm+0x222/0x648 [sctp]
[  264.968177]  [<000003ff80bbddac>] sctp_primitive_ASSOCIATE+0xbc/0xf8 [sctp]
[  264.968192]  [<000003ff80b93328>] __sctp_connect+0x830/0xc20 [sctp]
[  264.968208]  [<000003ff80bb11ce>] sctp_inet_connect+0x2e6/0x378 [sctp]
[  264.968212]  [<0000000001197942>] __sys_connect+0x21a/0x450
[  264.968215]  [<000000000119aff8>] sys_socketcall+0x3d0/0xb08
[  264.968218]  [<000000000184ea7a>] system_call+0x2a2/0x2c0

[...]

Just like ip_finish_output2() does for IPv4, check that we have enough
headroom in ip6_xmit(), and reallocate it if we don't.

This issue is older than git history.
Reported-by: Jianlin Shi <jishi@redhat.com>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

tcp_tso_should_defer() can return true in three different cases :

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

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

Fix this by properly populating the is_cwnd_limited and
is_rwnd_limited booleans.

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

The same move for EOR bit will be handled in net-next,
since commit 1c09f7d0 ("tcp: do not try to defer skbs
with eor mark (MSG_EOR)") is scheduled for linux-4.21

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

Fixes: 41727549 ("tcp: Do not underestimate rwnd_limited")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Suggested-by: Neal Cardwell <ncardwell@google.com>
Reviewed-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Reviewed-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pull vhost/virtio fixes from Michael Tsirkin:
 "A couple of last-minute fixes"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  vhost/vsock: fix use-after-free in network stack callers
  virtio/s390: fix race in ccw_io_helper()
  virtio/s390: avoid race on vcdev->config
  vhost/vsock: fix reset orphans race with close timeout

Pull arm64 fix from Catalin Marinas:
 "Avoid sending IPIs with interrupts disabled"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: hibernate: Avoid sending cross-calling with interrupts disabled