Hostfs was not setting up the backing device information, which means it
uses the noop bdi. The noop bdi does not have the writeback capability
enabled, which in turns means  dirty pages never got written back to
storage.

In other words programs using mmap to write to files on  hostfs never
actually got their data written out...

Fix this by simply setting up the bdi with default settings as all the
required code for writeback is already in place.
Signed-off-by: Sjoerd Simons <sjoerd@collabora.com>
Reviewed-by: Christopher Obbard <chris.obbard@collabora.com>
Tested-by: Ritesh Raj Sarraf <ritesh@collabora.com>
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

Use the macro 'swap()' defined in 'include/linux/minmax.h' to avoid
opencoding it.
Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Yang Guang <yang.guang5@zte.com.cn>
Signed-off-by: Richard Weinberger <richard@nod.at>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>

externs dead since before the initial merge
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>

get_vm(), add_iomem(), phys_offset() dead since 2004;
init_mem_user() and setup_memory() - since before the initial merge.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>

... had been dead for 15 years.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>

unused since 2011
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>

the function had been gone since 2012...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>

we need cpufeatures.h there
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>

Only one extern in there is needed in processor-generic.h, and it's
not needed anywhere else.  So move it over there and get rid of
the include in processor-generic.h, adding includes of registers.h
to the few files that need the declarations in it.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>

... same as the rest of implementations
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>

a bunch of detritus there - definitions that are never expanded or
checked.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>

When creating an external event, the current time needs to
be propagated to other participants of a simulation. This
is done in the places here where we kick a virtq etc.

However, it must be done for _all_ external events, and
that includes making the initial socket connection and
later closing it. Call time_travel_propagate_time() to do
this before making or closing the socket connection.

Apparently, at least for the initial connection creation,
due to the remote side in my use cases using microseconds
(rather than nanoseconds), this wasn't a problem yet; only
started failing between 5.14-rc1 and 5.15-rc1 (didn't test
others much), or possibly depending on the configuration,
where more delays happen before the virtio devices are
initialized.

Fixes: 88ce6424 ("um: Implement time-travel=ext")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

On 32-bit, the first entry might be at 0/NULL, but that's
strange and leads to issues, e.g. where we check "if (ret)".
Use a IOREMAP_BIAS/IOREMAP_MASK of 0x80000000UL to avoid
this. This then requires reducing the number of areas (via
MAX_AREAS), but we still have 128 areas, which is enough.

Fixes: ca2e3342 ("lib: add iomem emulation (logic_iomem)")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

On a 32-bit build, the (unsigned long long) casts throw warnings
(or errors) due to being to a different integer size. Cast to
uintptr_t first (with the __force for sparse) and then further
to get the consistent print on 32 and 64-bit.

Fixes: ca2e3342 ("lib: add iomem emulation (logic_iomem)")
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

There were a few 32-bit compile warnings that of course
turned into errors with -Werror, fix the 32-bit build.

Fixes: 68f5d3f3 ("um: add PCI over virtio emulation driver")
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

This file is generated, we should ignore it.

Fixes: d8fb32f4 ("um: Add support for host CPU flags and alignment")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-By: anton.ivanov@cambridgegreys.com
Signed-off-by: Richard Weinberger <richard@nod.at>

The function names init_registers() and restore_registers() are used
in several net/ethernet/ and gpu/drm/ drivers for other purposes (not
calls to UML functions), so rename them.

This fixes multiple build errors.
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: linux-um@lists.infradead.org
Signed-off-by: Richard Weinberger <richard@nod.at>

Fix the following coccinelle reports:

./arch/um/kernel/mem.c:89:2-5: WARNING: Use BUG_ON instead of if
condition followed by BUG.
Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Changcheng Deng <deng.changcheng@zte.com.cn>
Signed-off-by: Richard Weinberger <richard@nod.at>

The build system has started warning when filechk is called
without FORCE:

arch/x86/um/Makefile:44: FORCE prerequisite is missing

Add FORCE to make sure the file is checked/rebuilt when
necessary (and to quiet up the warning.)
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

Rename set_signals() as there's at least one driver that
uses the same name and can now be built on UM due to PCI
support, and thus we can get symbol conflicts.

Also rename set_signals_trace() to be consistent.
Reported-by: kernel test robot <lkp@intel.com>
Fixes: 68f5d3f3 ("um: add PCI over virtio emulation driver")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

Many places in the kernel use 'udelay' as an identifier, and
are broken with the current "#define udelay um_udelay". Fix
this by adding an argument to the macro, and do the same to
'ndelay' as well, just in case.

Fixes: 0bc8fb4d ("um: Implement ndelay/udelay in time-travel mode")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

Pull HID fixes from Jiri Kosina:

 - NULL pointer dereference fix in Vivaldi driver (Jiasheng Jiang)

 - regression fix for device probing in Holtek driver (Benjamin
   Tissoires)

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/hid/hid:
  HID: potential dereference of null pointer
  HID: holtek: fix mouse probing

Pull rdma fixes from Jason Gunthorpe:
 "Last fixes before holidays. Nothing very exciting:

   - Work around a HW bug in HNS HIP08

   - Recent memory leak regression in qib

   - Incorrect use of kfree() for vmalloc memory in hns"

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma:
  RDMA/hns: Replace kfree() with kvfree()
  IB/qib: Fix memory leak in qib_user_sdma_queue_pkts()
  RDMA/hns: Fix RNR retransmission issue for HIP08

Pull spi fix from Mark Brown:
 "One small fix for a long standing issue with error handling on probe
  in the Armada driver"

* tag 'spi-fix-v5.16-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi:
  spi: change clk_disable_unprepare to clk_unprepare

Merge tag 'regulator-fix-v5.16-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator

Pull regulator fix from Mark Brown:
 "Binding fix for v5.16

  This fixes problems validating DT bindings using op_mode which wasn't
  described as it should have been when converting to DT schema"

* tag 'regulator-fix-v5.16-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator:
  regulator: dt-bindings: samsung,s5m8767: add missing op_mode to bucks

Merge xen fixes from Juergen Gross:
 "Fixes for two issues related to Xen and malicious guests:

   - Guest can force the netback driver to hog large amounts of memory

   - Denial of Service in other guests due to event storms"

* 'xsa' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/netback: don't queue unlimited number of packages
  xen/netback: fix rx queue stall detection
  xen/console: harden hvc_xen against event channel storms
  xen/netfront: harden netfront against event channel storms
  xen/blkfront: harden blkfront against event channel storms

The return value of devm_kzalloc() needs to be checked.
To avoid hdev->dev->driver_data to be null in case of the failure of
alloc.

Fixes: 14c9c014 ("HID: add vivaldi HID driver")
Cc: stable@vger.kernel.org
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Link: https://lore.kernel.org/r/20211215083605.117638-1-jiasheng@iscas.ac.cn

An overlook from the previous commit: we don't even parse or start the
device, meaning that the device is not presented to user space.

Fixes: 93020953 ("HID: check for valid USB device for many HID drivers")
Cc: stable@vger.kernel.org
Link: https://bugs.archlinux.org/task/73048
Link: https://bugzilla.kernel.org/show_bug.cgi?id=215341
Link: https://lore.kernel.org/r/e4efbf13-bd8d-0370-629b-6c80c0044b15@leemhuis.info/Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>

Pull kvm fixes from Paolo Bonzini:
 "Two small fixes, one of which was being worked around in selftests"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: x86: Retry page fault if MMU reload is pending and root has no sp
  KVM: selftests: vmx_pmu_msrs_test: Drop tests mangling guest visible CPUIDs
  KVM: x86: Drop guest CPUID check for host initiated writes to MSR_IA32_PERF_CAPABILITIES

Pull block revert from Jens Axboe:
 "It turns out that the fix for not hammering on the delayed work timer
  too much caused a performance regression for BFQ, so let's revert the
  change for now.

  I've got some ideas on how to fix it appropriately, but they should
  wait for 5.17"

* tag 'block-5.16-2021-12-19' of git://git.kernel.dk/linux-block:
  Revert "block: reduce kblockd_mod_delayed_work_on() CPU consumption"

Pull irq fixes from Borislav Petkov:

 - Clear the PCI_MSIX_FLAGS_MASKALL bit too on the error path so that it
   is restored to its reset state

 - Mask MSI-X vectors late on the init path in order to handle
   out-of-spec Marvell NVME devices which apparently look at the MSI-X
   mask even when MSI-X is disabled

* tag 'irq_urgent_for_v5.16_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  PCI/MSI: Clear PCI_MSIX_FLAGS_MASKALL on error
  PCI/MSI: Mask MSI-X vectors only on success

Pull timer fix from Borislav Petkov:

 - Make sure the CLOCK_REALTIME to CLOCK_MONOTONIC offset is never
   positive

* tag 'timers_urgent_for_v5.16_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  timekeeping: Really make sure wall_to_monotonic isn't positive

Pull locking fix from Borislav Petkov:

 - Fix the rtmutex condition checking when the optimistic spinning of a
   waiter needs to be terminated

* tag 'locking_urgent_for_v5.16_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/rtmutex: Fix incorrect condition in rtmutex_spin_on_owner()