This remoes the code from the COW path to call debug_dma_assert_idle(),
which was added many years ago.

Google shows that it hasn't caught anything in the 6+ years we've had it
apart from a false positive, and Hugh just noticed how it had a very
unfortunate spinlock serialization in the COW path.

He fixed that issue the previous commit (a85ffd59: "dma-debug: fix
debug_dma_assert_idle(), use rcu_read_lock()"), but let's see if anybody
even notices when we remove this function entirely.

NOTE! We keep the dma tracking infrastructure that was added by the
commit that introduced it.  Partly to make it easier to resurrect this
debug code if we ever deside to, and partly because that tracking by pfn
and offset looks quite reasonable.

The problem with this debug code was simply that it was expensive and
didn't seem worth it, not that it was wrong per se.
Acked-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Since commit 2a9127fc ("mm: rewrite wait_on_page_bit_common()
logic") improved unlock_page(), it has become more noticeable how
cow_user_page() in a kernel with CONFIG_DMA_API_DEBUG=y can create and
suffer from heavy contention on DMA debug's radix_lock in
debug_dma_assert_idle().

It is only doing a lookup: use rcu_read_lock() and rcu_read_unlock()
instead; though that does require the static ents[] to be moved
onstack...

...but, hold on, isn't that radix_tree_gang_lookup() and loop doing
quite the wrong thing: searching CACHELINES_PER_PAGE entries for an
exact match with the first cacheline of the page in question?
radix_tree_gang_lookup() is the right tool for the job, but we need
nothing more than to check the first entry it can find, reporting if
that falls anywhere within the page.

(Is RCU safe here? As safe as using the spinlock was. The entries are
never freed, so don't need to be freed by RCU. They may be reused, and
there is a faint chance of a race, with an offending entry reused while
printing its error info; but the spinlock did not prevent that either,
and I agree that it's not worth worrying about. ]

[ Side noe: this patch is a clear improvement to the status quo, but the
  next patch will be removing this debug function entirely.

  But just in case we decide we want to resurrect the debugging code
  some day, I'm first applying this improvement patch so that it doesn't
  get lost    - Linus ]

Fixes: 3b7a6418 ("dma debug: account for cachelines and read-only mappings in overlap tracking")
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull timekeeping updates from Thomas Gleixner:
 "A set of timekeeping/VDSO updates:

   - Preparatory work to allow S390 to switch over to the generic VDSO
     implementation.

     S390 requires that the VDSO data pointer is handed in to the
     counter read function when time namespace support is enabled.
     Adding the pointer is a NOOP for all other architectures because
     the compiler is supposed to optimize that out when it is unused in
     the architecture specific inline. The change also solved a similar
     problem for MIPS which fortunately has time namespaces not yet
     enabled.

     S390 needs to update clock related VDSO data independent of the
     timekeeping updates. This was solved so far with yet another
     sequence counter in the S390 implementation. A better solution is
     to utilize the already existing VDSO sequence count for this. The
     core code now exposes helper functions which allow to serialize
     against the timekeeper code and against concurrent readers.

     S390 needs extra data for their clock readout function. The initial
     common VDSO data structure did not provide a way to add that. It
     now has an embedded architecture specific struct embedded which
     defaults to an empty struct.

     Doing this now avoids tree dependencies and conflicts post rc1 and
     allows all other architectures which work on generic VDSO support
     to work from a common upstream base.

   - A trivial comment fix"

* tag 'timers-urgent-2020-08-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  time: Delete repeated words in comments
  lib/vdso: Allow to add architecture-specific vdso data
  timekeeping/vsyscall: Provide vdso_update_begin/end()
  vdso/treewide: Add vdso_data pointer argument to __arch_get_hw_counter()

Pull more timer updates from Thomas Gleixner:
 "A set of posix CPU timer changes which allows to defer the heavy work
  of posix CPU timers into task work context. The tick interrupt is
  reduced to a quick check which queues the work which is doing the
  heavy lifting before returning to user space or going back to guest
  mode. Moving this out is deferring the signal delivery slightly but
  posix CPU timers are inaccurate by nature as they depend on the tick
  so there is no real damage. The relevant test cases all passed.

  This lifts the last offender for RT out of the hard interrupt context
  tick handler, but it also has the general benefit that the actual
  heavy work is accounted to the task/process and not to the tick
  interrupt itself.

  Further optimizations are possible to break long sighand lock hold and
  interrupt disabled (on !RT kernels) times when a massive amount of
  posix CPU timers (which are unpriviledged) is armed for a
  task/process.

  This is currently only enabled for x86 because the architecture has to
  ensure that task work is handled in KVM before entering a guest, which
  was just established for x86 with the new common entry/exit code which
  got merged post 5.8 and is not the case for other KVM architectures"

* tag 'timers-core-2020-08-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86: Select POSIX_CPU_TIMERS_TASK_WORK
  posix-cpu-timers: Provide mechanisms to defer timer handling to task_work
  posix-cpu-timers: Split run_posix_cpu_timers()

Pull irq fixes from Thomas Gleixner:
 "Two fixes in the core interrupt code which ensure that all error exits
  unlock the descriptor lock"

* tag 'irq-urgent-2020-08-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  genirq: Unlock irq descriptor after errors
  genirq/PM: Always unlock IRQ descriptor in rearm_wake_irq()

Pull OpenRISC updates from Stafford Horne:
 "A few patches all over the place during this cycle, mostly bug and
  sparse warning fixes for OpenRISC, but a few enhancements too. Note,
  there are 2 non OpenRISC specific fixups.

  Non OpenRISC fixes:

   - In init we need to align the init_task correctly to fix an issue
     with MUTEX_FLAGS, reviewed by Peter Z. No one picked this up so I
     kept it on my tree.

   - In asm-generic/io.h I fixed up some sparse warnings, OK'd by Arnd.
     Arnd asked to merge it via my tree.

  OpenRISC fixes:

   - Many fixes for OpenRISC sprase warnings.

   - Add support OpenRISC SMP tlb flushing rather than always flushing
     the entire TLB on every CPU.

   - Fix bug when dumping stack via /proc/xxx/stack of user threads"

* tag 'for-linus' of git://github.com/openrisc/linux:
  openrisc: uaccess: Add user address space check to access_ok
  openrisc: signal: Fix sparse address space warnings
  openrisc: uaccess: Remove unused macro __addr_ok
  openrisc: uaccess: Use static inline function in access_ok
  openrisc: uaccess: Fix sparse address space warnings
  openrisc: io: Fixup defines and move include to the end
  asm-generic/io.h: Fix sparse warnings on big-endian architectures
  openrisc: Implement proper SMP tlb flushing
  openrisc: Fix oops caused when dumping stack
  openrisc: Add support for external initrd images
  init: Align init_task to avoid conflict with MUTEX_FLAGS
  openrisc: fix __user in raw_copy_to_user()'s prototype

Pull powerpc fix from Michael Ellerman:
 "One fix for a boot crash on some platforms introduced by the recent
  pkey refactoring.

  Thanks to Christian Zigotzky and Aneesh Kumar K.V"

* tag 'powerpc-5.9-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/pkeys: Fix boot failures with Nemo board (A-EON AmigaOne X1000)

Pull more xen updates from Juergen Gross:

 - Remove support for running as 32-bit Xen PV-guest.

   32-bit PV guests are rarely used, are lacking security fixes for
   Meltdown, and can be easily replaced by PVH mode. Another series for
   doing more cleanup will follow soon (removal of 32-bit-only pvops
   functionality).

 - Fixes and additional features for the Xen display frontend driver.

* tag 'for-linus-5.9-rc1b-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  drm/xen-front: Pass dumb buffer data offset to the backend
  xen: Sync up with the canonical protocol definition in Xen
  drm/xen-front: Add YUYV to supported formats
  drm/xen-front: Fix misused IS_ERR_OR_NULL checks
  xen/gntdev: Fix dmabuf import with non-zero sgt offset
  x86/xen: drop tests for highmem in pv code
  x86/xen: eliminate xen-asm_64.S
  x86/xen: remove 32-bit Xen PV guest support

Pull hyper-v fixes from Wei Liu:

 - fix oops reporting on Hyper-V

 - make objtool happy

* tag 'hyperv-fixes-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  x86/hyperv: Make hv_setup_sched_clock inline
  Drivers: hv: vmbus: Only notify Hyper-V for die events that are oops

syzbot found its way in 86_fsgsbase_read_task() and triggered this oops:

   KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
   CPU: 0 PID: 6866 Comm: syz-executor262 Not tainted 5.8.0-syzkaller #0
   RIP: 0010:x86_fsgsbase_read_task+0x16d/0x310 arch/x86/kernel/process_64.c:393
   Call Trace:
     putreg32+0x3ab/0x530 arch/x86/kernel/ptrace.c:876
     genregs32_set arch/x86/kernel/ptrace.c:1026 [inline]
     genregs32_set+0xa4/0x100 arch/x86/kernel/ptrace.c:1006
     copy_regset_from_user include/linux/regset.h:326 [inline]
     ia32_arch_ptrace arch/x86/kernel/ptrace.c:1061 [inline]
     compat_arch_ptrace+0x36c/0xd90 arch/x86/kernel/ptrace.c:1198
     __do_compat_sys_ptrace kernel/ptrace.c:1420 [inline]
     __se_compat_sys_ptrace kernel/ptrace.c:1389 [inline]
     __ia32_compat_sys_ptrace+0x220/0x2f0 kernel/ptrace.c:1389
     do_syscall_32_irqs_on arch/x86/entry/common.c:84 [inline]
     __do_fast_syscall_32+0x57/0x80 arch/x86/entry/common.c:126
     do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:149
     entry_SYSENTER_compat_after_hwframe+0x4d/0x5c

This can happen if ptrace() or sigreturn() pokes an LDT selector into FS
or GS for a task with no LDT and something tries to read the base before
a return to usermode notices the bad selector and fixes it.

The fix is to make sure ldt pointer is not NULL.

Fixes: 07e1d88a ("x86/fsgsbase/64: Fix ptrace() to read the FS/GS base accurately")
Co-developed-by: Jann Horn <jannh@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Acked-by: Andy Lutomirski <luto@kernel.org>
Cc: Chang S. Bae <chang.seok.bae@intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Markus T Metzger <markus.t.metzger@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Shankar <ravi.v.shankar@intel.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull crypto fix from Herbert Xu:
 "This fixes a regression in af_alg"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: algif_aead - fix uninitialized ctx->init

Pull module updates from Jessica Yu:
 "The most important change would be Christoph Hellwig's patch
  implementing proprietary taint inheritance, in an effort to discourage
  the creation of GPL "shim" modules that interface between GPL symbols
  and proprietary symbols.

  Summary:

   - Have modules that use symbols from proprietary modules inherit the
     TAINT_PROPRIETARY_MODULE taint, in an effort to prevent GPL shim
     modules that are used to circumvent _GPL exports. These are modules
     that claim to be GPL licensed while also using symbols from
     proprietary modules. Such modules will be rejected while non-GPL
     modules will inherit the proprietary taint.

   - Module export space cleanup. Unexport symbols that are unused
     outside of module.c or otherwise used in only built-in code"

* tag 'modules-for-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux:
  modules: inherit TAINT_PROPRIETARY_MODULE
  modules: return licensing information from find_symbol
  modules: rename the licence field in struct symsearch to license
  modules: unexport __module_address
  modules: unexport __module_text_address
  modules: mark each_symbol_section static
  modules: mark find_symbol static
  modules: mark ref_module static
  modules: linux/moduleparam.h: drop duplicated word in a comment

Pull Kconfig updates from Masahiro Yamada:

 - remove '---help---' keyword support

 - fix mouse events for 'menuconfig' symbols in search view of qconf

 - code cleanups of qconf

* tag 'kconfig-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (24 commits)
  kconfig: qconf: move setOptionMode() to ConfigList from ConfigView
  kconfig: qconf: do not limit the pop-up menu to the first row
  kconfig: qconf: refactor icon setups
  kconfig: qconf: remove unused voidPix, menuInvPix
  kconfig: qconf: remove ConfigItem::text/setText
  kconfig: qconf: remove ConfigList::addColumn/removeColumn
  kconfig: qconf: remove ConfigItem::pixmap/setPixmap
  kconfig: qconf: drop more localization code
  kconfig: qconf: remove 'parent' from ConfigList::updateMenuList()
  kconfig: qconf: remove unused argument from ConfigView::updateList()
  kconfig: qconf: remove unused argument from ConfigList::updateList()
  kconfig: qconf: omit parent to QHBoxLayout()
  kconfig: qconf: remove name from ConfigSearchWindow constructor
  kconfig: qconf: remove unused ConfigList::listView()
  kconfig: qconf: overload addToolBar() to create and insert toolbar
  kconfig: qconf: remove toolBar from ConfigMainWindow members
  kconfig: qconf: use 'menu' variable for (QMenu *)
  kconfig: qconf: do not use 'menu' variable for (QMenuBar *)
  kconfig: qconf: remove ->addSeparator() to menuBar
  kconfig: add 'static' to some file-local data
  ...

ConfigView::setOptionMode() only gets access to the 'list' member.

Move it to the more relevant ConfigList class.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

If you right-click the first row in the option tree, the pop-up menu
shows up, but if you right-click the second row or below, the event
is ignored due to the following check:

  if (e->y() <= header()->geometry().bottom()) {

Perhaps, the intention was to show the pop-menu only when the tree
header was right-clicked, but this handler is not called in that case.

Since the origin of e->y() starts from the bottom of the header,
this check is odd.

Going forward, you can right-click anywhere in the tree to get the
pop-up menu.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

These icon data are used by ConfigItem, but stored in each instance
of ConfigView. There is no point to keep the same data in each of 3
instances, "menu", "config", and "search".

Move the icon data to the more relevant ConfigItem class, and make
them static members.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

These are initialized, but not used by anyone.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Use QTreeWidgetItem::text/setText directly
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Use QTreeView::showColumn/hideColumn directly.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Use QTreeWidgetItem::icon/setIcon directly.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

This is a remnant of commit 694c49a7 ("kconfig: drop localization
support").

Get it back to the code prior to commit 3b9fa093 ("[PATCH] Kconfig
i18n support").
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

All the call-sites of this function pass 'this' to the first argument.

So, 'parent' is always the 'this' pointer.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Now that ConfigList::updateList() takes no argument, the 'item' argument
ConfigView::updateList() is no longer used.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

This function allocates 'item' before using it, so the argument 'item'
is always shadowed.

Remove the meaningless argument.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Instead of passing 0 (i.e. nullptr), leave it empty.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

This constructor is only called with "search" as the second argument.

Hard-code the name in the constructor, and drop it from the function
argument.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

I do not know how this function can be useful. In fact, it is unsed.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Use the overloaded function, addToolBar(const QString &title)
to create a QToolBar object, setting its window title, and inserts
it into the toolbar area.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

This pointer is only used in the ConfigMainWindow constructor.

Drop it from the private members.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

The variable 'config' for the file menu is inconsistent.

You do not need to use different variables. Use 'menu' for every menu.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

I think it is a bit confusing to use 'menu' to hold a QMenuBar pointer.
I want to use 'menu' for a QMenu pointer.

You do not need to use a local variable here. Use menuBar() directly.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

I do not understand the purpose of this ->addSeparator().
It does not make any difference.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Fix some warnings from sparce like follows:

  warning: symbol '...' was not declared. Should it be static?
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

On menu properties mouse events didn't do anything in search view
(listMode).

As there are no menus in listMode we can add an exception in tests to
always change the value on mouse events if we are in listMode.
Signed-off-by: Maxime Chretien <maxime.chretien@bootlin.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Constify arrays as well as strings.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

This reverts commit 84af7a61.

The conversion is done.

Cc: Ulf Magnusson <ulfalizer@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

The conversion is done. No more user of '---help---'.

Cc: Ulf Magnusson <ulfalizer@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Pull networking fixes from David Miller:
 "Some merge window fallout, some longer term fixes:

   1) Handle headroom properly in lapbether and x25_asy drivers, from
      Xie He.

   2) Fetch MAC address from correct r8152 device node, from Thierry
      Reding.

   3) In the sw kTLS path we should allow MSG_CMSG_COMPAT in sendmsg,
      from Rouven Czerwinski.

   4) Correct fdputs in socket layer, from Miaohe Lin.

   5) Revert troublesome sockptr_t optimization, from Christoph Hellwig.

   6) Fix TCP TFO key reading on big endian, from Jason Baron.

   7) Missing CAP_NET_RAW check in nfc, from Qingyu Li.

   8) Fix inet fastreuse optimization with tproxy sockets, from Tim
      Froidcoeur.

   9) Fix 64-bit divide in new SFC driver, from Edward Cree.

  10) Add a tracepoint for prandom_u32 so that we can more easily
      perform usage analysis. From Eric Dumazet.

  11) Fix rwlock imbalance in AF_PACKET, from John Ogness"

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (49 commits)
  net: openvswitch: introduce common code for flushing flows
  af_packet: TPACKET_V3: fix fill status rwlock imbalance
  random32: add a tracepoint for prandom_u32()
  Revert "ipv4: tunnel: fix compilation on ARCH=um"
  net: accept an empty mask in /sys/class/net/*/queues/rx-*/rps_cpus
  net: ethernet: stmmac: Disable hardware multicast filter
  net: stmmac: dwmac1000: provide multicast filter fallback
  ipv4: tunnel: fix compilation on ARCH=um
  vsock: fix potential null pointer dereference in vsock_poll()
  sfc: fix ef100 design-param checking
  net: initialize fastreuse on inet_inherit_port
  net: refactor bind_bucket fastreuse into helper
  net: phy: marvell10g: fix null pointer dereference
  net: Fix potential memory leak in proto_register()
  net: qcom/emac: add missed clk_disable_unprepare in error path of emac_clks_phase1_init
  ionic_lif: Use devm_kcalloc() in ionic_qcq_alloc()
  net/nfc/rawsock.c: add CAP_NET_RAW check.
  hinic: fix strncpy output truncated compile warnings
  drivers/net/wan/x25_asy: Added needed_headroom and a skb->len check
  net/tls: Fix kmap usage
  ...

Pull i2c updates from Wolfram Sang:

 - bus recovery can now be given a pinctrl handle and the I2C core will
   do all the steps to switch to/from GPIO which can save quite some
   boilerplate code from drivers

 - "fallthrough" conversion

 - driver updates, mostly ID additions

* 'i2c/for-5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (32 commits)
  i2c: iproc: fix race between client unreg and isr
  i2c: eg20t: use generic power management
  i2c: eg20t: Drop PCI wakeup calls from .suspend/.resume
  i2c: mediatek: Fix i2c_spec_values description
  i2c: mediatek: Add i2c compatible for MediaTek MT8192
  dt-bindings: i2c: update bindings for MT8192 SoC
  i2c: mediatek: Add access to more than 8GB dram in i2c driver
  i2c: mediatek: Add apdma sync in i2c driver
  i2c: i801: Add support for Intel Tiger Lake PCH-H
  i2c: i801: Add support for Intel Emmitsburg PCH
  i2c: bcm2835: Replace HTTP links with HTTPS ones
  Documentation: i2c: dev: 'block process call' is supported
  i2c: at91: Move to generic GPIO bus recovery
  i2c: core: treat EPROBE_DEFER when acquiring SCL/SDA GPIOs
  i2c: core: add generic I2C GPIO recovery
  dt-bindings: i2c: add generic properties for GPIO bus recovery
  i2c: rcar: avoid race when unregistering slave
  i2c: tegra: Avoid tegra_i2c_init_dma() for Tegra210 vi i2c
  i2c: tegra: Fix runtime resume to re-init VI I2C
  i2c: tegra: Fix the error path in tegra_i2c_runtime_resume
  ...

To avoid some issues, for example RCU usage warning and double free,
we should flush the flows under ovs_lock. This patch refactors
table_instance_destroy and introduces table_instance_flow_flush
which can be invoked by __dp_destroy or ovs_flow_tbl_flush.

Fixes: 50b0e61b ("net: openvswitch: fix possible memleak on destroy flow-table")
Reported-by: Johan Knöös <jknoos@google.com>
Reported-at: https://mail.openvswitch.org/pipermail/ovs-discuss/2020-August/050489.htmlSigned-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
Reviewed-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>