Add wrappers to get/set status and protect these operations with
cf_mutex to serialize these operations with respect to get/set config
operations.
Signed-off-by: NEli Cohen <elic@nvidia.com>
Link: https://lore.kernel.org/r/20220105114646.577224-4-elic@nvidia.comSigned-off-by: NMichael S. Tsirkin <mst@redhat.com>

Distribute the available rx virtqueues amongst the available RQT
entries.

RQTs require to have a power of two entries. When creating or modifying
the RQT, use the lowest number of power of two entries that is not less
than the number of rx virtqueues. Distribute them in the available
entries such that some virtqueus may be referenced twice.

This allows to configure any number of virtqueue pairs when multiqueue
is used.
Reviewed-by: NSi-Wei Liu <si-wei.liu@oracle.com>
Acked-by: NJason Wang <jasowang@redhat.com>
Signed-off-by: NEli Cohen <elic@nvidia.com>
Link: https://lore.kernel.org/r/20220105114646.577224-3-elic@nvidia.comSigned-off-by: NMichael S. Tsirkin <mst@redhat.com>

Provide an interface to read the negotiated features. This is needed
when building the netlink message in vdpa_dev_net_config_fill().

Also fix the implementation of vdpa_dev_net_config_fill() to use the
negotiated features instead of the device features.

To make APIs clearer, make the following name changes to struct
vdpa_config_ops so they better describe their operations:

get_features -> get_device_features
set_features -> set_driver_features

Finally, add get_driver_features to return the negotiated features and
add implementation to all the upstream drivers.
Acked-by: NJason Wang <jasowang@redhat.com>
Signed-off-by: NEli Cohen <elic@nvidia.com>
Link: https://lore.kernel.org/r/20220105114646.577224-2-elic@nvidia.comSigned-off-by: NMichael S. Tsirkin <mst@redhat.com>

The return type of get_config_size is size_t so it makes
sense to change the type of the variable holding its result.

That said, this already got taken care of (differently, and arguably
not as well) by commit 3ed21c14 ("vdpa: check that offsets are
within bounds").

The added 'c->off > size' test in that commit will be done as an
unsigned comparison on 32-bit (safe due to not being signed).

On a 64-bit platform, it will be done as a signed comparison, but in
that case the comparison will be done in 64-bit, and 'c->off' being an
u32 it will be valid thanks to the extended range (ie both values will
be positive in 64 bits).

So this was a real bug, but it was already addressed and marked for stable.
Signed-off-by: NLaura Abbott <labbott@kernel.org>
Reported-by: NLuo Likang <luolikang@nsfocus.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>

A recently added error path does not mark ring unused when exiting on
OOM, which will lead to BUG on the next entry in debug builds.

TODO: refactor code so we have START_USE and END_USE in the same function.

Fixes: fc6d70f4 ("virtio_ring: check desc == NULL when using indirect with packed")
Cc: "Xuan Zhuo" <xuanzhuo@linux.alibaba.com>
Cc: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Reviewed-by: NXuan Zhuo <xuanzhuo@linux.alibaba.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>

We need free the vqs in .release(), which are allocated in .open().
Signed-off-by: NXianting Tian <xianting.tian@linux.alibaba.com>
Link: https://lore.kernel.org/r/20211228030924.3468439-1-xianting.tian@linux.alibaba.comSigned-off-by: NMichael S. Tsirkin <mst@redhat.com>
Acked-by: NJason Wang <jasowang@redhat.com>

Remove overriding of virtio_version_1_0 which forced the virtqueue
object to version 1.

Fixes: 1a86b377 ("vdpa/mlx5: Add VDPA driver for supported mlx5 devices")
Signed-off-by: NEli Cohen <elic@nvidia.com>
Link: https://lore.kernel.org/r/20211230142024.142979-1-elic@nvidia.comSigned-off-by: NMichael S. Tsirkin <mst@redhat.com>
Reviewed-by: NParav Pandit <parav@nvidia.com>
Acked-by: NJason Wang <jasowang@redhat.com>
Reviewed-by: NSi-Wei Liu <si-wei.liu@oracle.com>

When pci_iomap return NULL, the return value is zero.
Signed-off-by: NPeng Hao <flyingpeng@tencent.com>
Link: https://lore.kernel.org/r/20211222112014.87394-1-flyingpeng@tencent.comSigned-off-by: NMichael S. Tsirkin <mst@redhat.com>
Acked-by: NJason Wang <jasowang@redhat.com>

There is a check for vm->sbm.sb_states before, and it should check
it here as well.
Signed-off-by: NPeng Hao <flyingpeng@tencent.com>
Link: https://lore.kernel.org/r/20211222011225.40573-1-flyingpeng@tencent.comSigned-off-by: NMichael S. Tsirkin <mst@redhat.com>
Fixes: 5f1f79bb ("virtio-mem: Paravirtualized memory hotplug")
Cc: stable@vger.kernel.org # v5.8+

Function name "vp_modern_remove" in comments is written to
"vp_modern_probe" incorrectly. Change it.
Signed-off-by: NDapeng Mi <dapeng1.mi@intel.com>
Link: https://lore.kernel.org/r/20211210073546.700783-1-dapeng1.mi@intel.comSigned-off-by: NMichael S. Tsirkin <mst@redhat.com>
Reviewed-by: NStefano Garzarella <sgarzare@redhat.com>

The error message on the failure of pfn check should tell
virtio-pci rather than virtio-mmio, just fix it.
Signed-off-by: NMichael Wang <yun.wang@linux.alibaba.com>
Suggested-by: NMichael S. Tsirkin <mst@redhat.com>
Link: https://lore.kernel.org/r/ae5e154e-ac59-f0fa-a7c7-091a2201f581@linux.alibaba.comSigned-off-by: NMichael S. Tsirkin <mst@redhat.com>

Explicitly remove the file entries from sysfs before dropping the final
reference for symmetry reasons and for consistency with the rest of the
driver.
Signed-off-by: NJohan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20211201132528.30025-5-johan@kernel.orgSigned-off-by: NMichael S. Tsirkin <mst@redhat.com>

Make sure to always NUL-terminate file names retrieved from the firmware
to avoid accessing data beyond the entry slab buffer and exposing it
through sysfs in case the firmware data is corrupt.

Fixes: 75f3e8e4 ("firmware: introduce sysfs driver for QEMU's fw_cfg device")
Cc: stable@vger.kernel.org      # 4.6
Cc: Gabriel Somlo <somlo@cmu.edu>
Signed-off-by: NJohan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20211201132528.30025-4-johan@kernel.orgSigned-off-by: NMichael S. Tsirkin <mst@redhat.com>

An initialised kobject must be freed using kobject_put() to avoid
leaking associated resources (e.g. the object name).

Commit fe3c6068 ("firmware: Fix a reference count leak.") "fixed"
the leak in the first error path of the file registration helper but
left the second one unchanged. This "fix" would however result in a NULL
pointer dereference due to the release function also removing the never
added entry from the fw_cfg_entry_cache list. This has now been
addressed.

Fix the remaining kobject leak by restoring the common error path and
adding the missing kobject_put().

Fixes: 75f3e8e4 ("firmware: introduce sysfs driver for QEMU's fw_cfg device")
Cc: stable@vger.kernel.org      # 4.6
Cc: Gabriel Somlo <somlo@cmu.edu>
Signed-off-by: NJohan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20211201132528.30025-3-johan@kernel.orgSigned-off-by: NMichael S. Tsirkin <mst@redhat.com>

Commit fe3c6068 ("firmware: Fix a reference count leak.") "fixed"
a kobject leak in the file registration helper by properly calling
kobject_put() for the entry in case registration of the object fails
(e.g. due to a name collision).

This would however result in a NULL pointer dereference when the
release function tries to remove the never added entry from the
fw_cfg_entry_cache list.

Fix this by moving the list-removal out of the release function.

Note that the offending commit was one of the benign looking umn.edu
fixes which was reviewed but not reverted. [1][2]

[1] https://lore.kernel.org/r/202105051005.49BFABCE@keescook
[2] https://lore.kernel.org/all/YIg7ZOZvS3a8LjSv@kroah.com

Fixes: fe3c6068 ("firmware: Fix a reference count leak.")
Cc: stable@vger.kernel.org      # 5.8
Cc: Qiushi Wu <wu000273@umn.edu>
Cc: Kees Cook <keescook@chromium.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20211201132528.30025-2-johan@kernel.orgSigned-off-by: NMichael S. Tsirkin <mst@redhat.com>

Since vhost_vdpa_mmap checks for its existence before calling it.
Signed-off-by: NEugenio Pérez <eperezma@redhat.com>
Link: https://lore.kernel.org/r/20211104195248.2088904-1-eperezma@redhat.comSigned-off-by: NMichael S. Tsirkin <mst@redhat.com>
Acked-by: NJason Wang <jasowang@redhat.com>
Reviewed-by: NStefano Garzarella <sgarzare@redhat.com>

It has no sense to call get_status twice, since we already have a
variable for that.
Signed-off-by: NEugenio Pérez <eperezma@redhat.com>
Link: https://lore.kernel.org/r/20211104195833.2089796-1-eperezma@redhat.comSigned-off-by: NMichael S. Tsirkin <mst@redhat.com>
Acked-by: NJason Wang <jasowang@redhat.com>
Reviewed-by: NStefano Garzarella <sgarzare@redhat.com>

When 'pcim_enable_device()' is used, some resources become automagically
managed.
There is no need to call 'pci_free_irq_vectors()' when the driver is
removed. The same will already be done by 'pcim_release()'.
Signed-off-by: NChristophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/02045bdcbbb25f79bae4827f66029cfcddc90381.1636301587.git.christophe.jaillet@wanadoo.frSigned-off-by: NMichael S. Tsirkin <mst@redhat.com>
Acked-by: NJason Wang <jasowang@redhat.com>

Make sure to offer VIRTIO_NET_F_MTU since we configure the MTU based on
what was queried from the device.

This allows the virtio driver to allocate large enough buffers based on
the reported MTU.
Signed-off-by: NEli Cohen <elic@nvidia.com>
Link: https://lore.kernel.org/r/20211124170949.51725-1-elic@nvidia.comSigned-off-by: NMichael S. Tsirkin <mst@redhat.com>
Acked-by: NJason Wang <jasowang@redhat.com>
Reviewed-by: NSi-Wei Liu <si-wei.liu@oracle.com>

Let's prepare our fake page onlining code for subblock size smaller than
MAX_ORDER - 1: we might get called for ranges not covering properly
aligned MAX_ORDER - 1 pages. We have to detect the order to use
dynamically.
Signed-off-by: NDavid Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20211126134209.17332-3-david@redhat.comSigned-off-by: NMichael S. Tsirkin <mst@redhat.com>
Reviewed-by: NZi Yan <ziy@nvidia.com>
Reviewed-by: NEric Ren <renzhengeek@gmail.com>

Let's prepare our page onlining code for subblock size smaller than
MAX_ORDER - 1: we'll get called for a MAX_ORDER - 1 page but might have
some subblocks in the range plugged and some unplugged. In that case,
fallback to subblock granularity to properly only expose the plugged
parts to the buddy.
Signed-off-by: NDavid Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20211126134209.17332-2-david@redhat.comSigned-off-by: NMichael S. Tsirkin <mst@redhat.com>
Reviewed-by: NZi Yan <ziy@nvidia.com>
Reviewed-by: NEric Ren <renzhengeek@gmail.com>

`driver_override` allows to control which of the vDPA bus drivers
binds to a vDPA device.

If `driver_override` is not set, the previous behaviour is followed:
devices use the first vDPA bus driver loaded (unless auto binding
is disabled).

Tested on Fedora 34 with driverctl(8):
  $ modprobe virtio-vdpa
  $ modprobe vhost-vdpa
  $ modprobe vdpa-sim-net

  $ vdpa dev add mgmtdev vdpasim_net name dev1

  # dev1 is attached to the first vDPA bus driver loaded
  $ driverctl -b vdpa list-devices
    dev1 virtio_vdpa

  $ driverctl -b vdpa set-override dev1 vhost_vdpa

  $ driverctl -b vdpa list-devices
    dev1 vhost_vdpa [*]

  Note: driverctl(8) integrates with udev so the binding is
  preserved.
Suggested-by: NJason Wang <jasowang@redhat.com>
Acked-by: NJason Wang <jasowang@redhat.com>
Signed-off-by: NStefano Garzarella <sgarzare@redhat.com>
Link: https://lore.kernel.org/r/20211126164753.181829-3-sgarzare@redhat.comSigned-off-by: NMichael S. Tsirkin <mst@redhat.com>

Add missing documentation of sysfs ABI for vDPA bus in
the new Documentation/ABI/testing/sysfs-bus-vdpa file.
Signed-off-by: NStefano Garzarella <sgarzare@redhat.com>
Link: https://lore.kernel.org/r/20211126164753.181829-2-sgarzare@redhat.comSigned-off-by: NMichael S. Tsirkin <mst@redhat.com>
Acked-by: NJason Wang <jasowang@redhat.com>

This commit fixes a misuse of virtio-net device config size issue
for virtio-block devices.

A new member config_size in struct ifcvf_hw is introduced and would
be initialized through vdpa_dev_add() to record correct device
config size.

To be more generic, rename ifcvf_hw.net_config to ifcvf_hw.dev_config,
the helpers ifcvf_read/write_net_config() to ifcvf_read/write_dev_config()
Signed-off-by: NZhu Lingshan <lingshan.zhu@intel.com>
Reported-and-suggested-by: NStefano Garzarella <sgarzare@redhat.com>
Reviewed-by: NStefano Garzarella <sgarzare@redhat.com>
Fixes: 6ad31d16 ("vDPA/ifcvf: enable Intel C5000X-PL virtio-block for vDPA")
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20211201081255.60187-1-lingshan.zhu@intel.comSigned-off-by: NMichael S. Tsirkin <mst@redhat.com>

This free action should be moved into caller 'vduse_ioctl' in
concert with the allocation.

No functional change.
Signed-off-by: NGuanjun <guanjun@linux.alibaba.com>
Link: https://lore.kernel.org/r/1638780498-55571-1-git-send-email-guanjun@linux.alibaba.comSigned-off-by: NMichael S. Tsirkin <mst@redhat.com>

unregister after reset is clearly wrong - device
can be used while it's reset. There's an attempt to
protect against that using hwrng_removed but it
seems racy since access can be in progress
when the flag is set.

Just unregister, then reset seems simpler and cleaner.
NB: we might be able to drop hwrng_removed in a follow-up patch.
Signed-off-by: NLaurent Vivier <lvivier@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>

This will enable cleanups down the road.
The idea is to disable cbs, then add "flush_queued_cbs" callback
as a parameter, this way drivers can flush any work
queued after callbacks have been disabled.
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Link: https://lore.kernel.org/r/20211013105226.20225-1-mst@redhat.comSigned-off-by: NMichael S. Tsirkin <mst@redhat.com>

Merge tag 'perf-tools-fixes-for-v5.16-2022-01-02' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux

Pull perf tools fixes from Arnaldo Carvalho de Melo:

 - Fix TUI exit screen refresh race condition in 'perf top'.

 - Fix parsing of Intel PT VM time correlation arguments.

 - Honour CPU filtering command line request of a script's switch events
   in 'perf script'.

 - Fix printing of switch events in Intel PT python script.

 - Fix duplicate alias events list printing in 'perf list', noticed on
   heterogeneous arm64 systems.

 - Fix return value of ids__new(), users expect NULL for failure, not
   ERR_PTR(-ENOMEM).

* tag 'perf-tools-fixes-for-v5.16-2022-01-02' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux:
  perf top: Fix TUI exit screen refresh race condition
  perf pmu: Fix alias events list
  perf scripts python: intel-pt-events.py: Fix printing of switch events
  perf script: Fix CPU filtering of a script's switch events
  perf intel-pt: Fix parsing of VM time correlation arguments
  perf expr: Fix return value of ids__new()

Pull i2c fixes from Wolfram Sang:
 "Better input validation for compat ioctls and a documentation bugfix
  for 5.16"

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  Docs: Fixes link to I2C specification
  i2c: validate user data in compat ioctl

Pull x86 fix from Borislav Petkov:

 - Use the proper CONFIG symbol in a preprocessor check.

* tag 'x86_urgent_for_v5.16_rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/build: Use the proper name CONFIG_FW_LOADER

When the following command is executed several times, a coredump file is
generated.

	$ timeout -k 9 5 perf top -e task-clock
	*******
	*******
	*******
	0.01%  [kernel]                  [k] __do_softirq
	0.01%  libpthread-2.28.so        [.] __pthread_mutex_lock
	0.01%  [kernel]                  [k] __ll_sc_atomic64_sub_return
	double free or corruption (!prev) perf top --sort comm,dso
	timeout: the monitored command dumped core

When we terminate "perf top" using sending signal method,
SLsmg_reset_smg() called. SLsmg_reset_smg() resets the SLsmg screen
management routines by freeing all memory allocated while it was active.

However SLsmg_reinit_smg() maybe be called by another thread.

SLsmg_reinit_smg() will free the same memory accessed by
SLsmg_reset_smg(), thus it results in a double free.

SLsmg_reinit_smg() is called already protected by ui__lock, so we fix
the problem by adding pthread_mutex_trylock of ui__lock when calling
SLsmg_reset_smg().
Signed-off-by: NWenyu Liu <liuwenyu7@huawei.com>
Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: wuxu.wu@huawei.com
Link: http://lore.kernel.org/lkml/a91e3943-7ddc-f5c0-a7f5-360f073c20e6@huawei.comSigned-off-by: NHewenliang <hewenliang4@huawei.com>
Signed-off-by: Nyaowenbin <yaowenbin1@huawei.com>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Commit 0e0ae874 ("perf list: Display hybrid PMU events with cpu
type") changes the event list for uncore PMUs or arm64 heterogeneous CPU
systems, such that duplicate aliases are incorrectly listed per PMU
(which they should not be), like:

  # perf list
  ...
  unc_cbo_cache_lookup.any_es
  [Unit: uncore_cbox L3 Lookup any request that access cache and found
  line in E or S-state]
  unc_cbo_cache_lookup.any_es
  [Unit: uncore_cbox L3 Lookup any request that access cache and found
  line in E or S-state]
  unc_cbo_cache_lookup.any_i
  [Unit: uncore_cbox L3 Lookup any request that access cache and found
  line in I-state]
  unc_cbo_cache_lookup.any_i
  [Unit: uncore_cbox L3 Lookup any request that access cache and found
  line in I-state]
  ...

Notice how the events are listed twice.

The named commit changed how we remove duplicate events, in that events
for different PMUs are not treated as duplicates. I suppose this is to
handle how "Each hybrid pmu event has been assigned with a pmu name".

Fix PMU alias listing by restoring behaviour to remove duplicates for
non-hybrid PMUs.

Fixes: 0e0ae874 ("perf list: Display hybrid PMU events with cpu type")
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Tested-by: NZhengjun Xing <zhengjun.xing@linux.intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/1640103090-140490-1-git-send-email-john.garry@huawei.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Pull input fixes from Dmitry Torokhov:
 "Two small fixups for spaceball joystick driver and appletouch touchpad
  driver"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: spaceball - fix parsing of movement data packets
  Input: appletouch - initialize work before device registration

Hugh Dickins reported the following

	My tmpfs swapping load (tweaked to use huge pages more heavily
	than in real life) is far from being a realistic load: but it was
	notably slowed down by your throttling mods in 5.16-rc, and this
	patch makes it well again - thanks.

	But: it very quickly hit NULL pointer until I changed that last
	line to

        if (first_pgdat)
                consider_reclaim_throttle(first_pgdat, sc);

The likely issue is that huge pages are a major component of the test
workload.  When this is the case, first_pgdat may never get set if
compaction is ready to continue due to this check

        if (IS_ENABLED(CONFIG_COMPACTION) &&
            sc->order > PAGE_ALLOC_COSTLY_ORDER &&
            compaction_ready(zone, sc)) {
                sc->compaction_ready = true;
                continue;
        }

If this was true for every zone in the zonelist, first_pgdat would never
get set resulting in a NULL pointer exception.

Link: https://lkml.kernel.org/r/20211209095453.GM3366@techsingularity.net
Fixes: 1b4e3f26 ("mm: vmscan: Reduce throttling due to a failure to make progress")
Signed-off-by: NMel Gorman <mgorman@techsingularity.net>
Reported-by: NHugh Dickins <hughd@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Rik van Riel <riel@surriel.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Darrick J. Wong <djwong@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Mike Galbraith, Alexey Avramov and Darrick Wong all reported similar
problems due to reclaim throttling for excessive lengths of time.  In
Alexey's case, a memory hog that should go OOM quickly stalls for
several minutes before stalling.  In Mike and Darrick's cases, a small
memcg environment stalled excessively even though the system had enough
memory overall.

Commit 69392a40 ("mm/vmscan: throttle reclaim when no progress is
being made") introduced the problem although commit a19594ca
("mm/vmscan: increase the timeout if page reclaim is not making
progress") made it worse.  Systems at or near an OOM state that cannot
be recovered must reach OOM quickly and memcg should kill tasks if a
memcg is near OOM.

To address this, only stall for the first zone in the zonelist, reduce
the timeout to 1 tick for VMSCAN_THROTTLE_NOPROGRESS and only stall if
the scan control nr_reclaimed is 0, kswapd is still active and there
were excessive pages pending for writeback.  If kswapd has stopped
reclaiming due to excessive failures, do not stall at all so that OOM
triggers relatively quickly.  Similarly, if an LRU is simply congested,
only lightly throttle similar to NOPROGRESS.

Alexey's original case was the most straight forward

	for i in {1..3}; do tail /dev/zero; done

On vanilla 5.16-rc1, this test stalled heavily, after the patch the test
completes in a few seconds similar to 5.15.

Alexey's second test case added watching a youtube video while tail runs
10 times.  On 5.15, playback only jitters slightly, 5.16-rc1 stalls a
lot with lots of frames missing and numerous audio glitches.  With this
patch applies, the video plays similarly to 5.15.

[lkp@intel.com: Fix W=1 build warning]

Link: https://lore.kernel.org/r/99e779783d6c7fce96448a3402061b9dc1b3b602.camel@gmx.de
Link: https://lore.kernel.org/r/20211124011954.7cab9bb4@mail.inbox.lv
Link: https://lore.kernel.org/r/20211022144651.19914-1-mgorman@techsingularity.net
Link: https://lore.kernel.org/r/20211202150614.22440-1-mgorman@techsingularity.net
Link: https://linux-regtracking.leemhuis.info/regzbot/regression/20211124011954.7cab9bb4@mail.inbox.lv/Reported-and-tested-by: NAlexey Avramov <hakavlad@inbox.lv>
Reported-and-tested-by: NMike Galbraith <efault@gmx.de>
Reported-and-tested-by: NDarrick J. Wong <djwong@kernel.org>
Reported-by: Nkernel test robot <lkp@intel.com>
Acked-by: NHugh Dickins <hughd@google.com>
Tracked-by: NThorsten Leemhuis <regressions@leemhuis.info>
Fixes: 69392a40 ("mm/vmscan: throttle reclaim when no progress is being made")
Signed-off-by: NMel Gorman <mgorman@techsingularity.net>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Merge misc mm fixes from Andrew Morton:
 "2 patches.

  Subsystems affected by this patch series: mm (userfaultfd and damon)"

* akpm:
  mm/damon/dbgfs: fix 'struct pid' leaks in 'dbgfs_target_ids_write()'
  userfaultfd/selftests: fix hugetlb area allocations

Pull SCSI fixes from James Bottomley:
 "Three fixes, all in drivers. The lpfc one doesn't look exploitable,
  but nasty things could happen in string operations if mybuf ends up
  with an on stack unterminated string"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: vmw_pvscsi: Set residual data length conditionally
  scsi: libiscsi: Fix UAF in iscsi_conn_get_param()/iscsi_conn_teardown()
  scsi: lpfc: Terminate string in lpfc_debugfs_nvmeio_trc_write()

DAMON debugfs interface increases the reference counts of 'struct pid's
for targets from the 'target_ids' file write callback
('dbgfs_target_ids_write()'), but decreases the counts only in DAMON
monitoring termination callback ('dbgfs_before_terminate()').

Therefore, when 'target_ids' file is repeatedly written without DAMON
monitoring start/termination, the reference count is not decreased and
therefore memory for the 'struct pid' cannot be freed.  This commit
fixes this issue by decreasing the reference counts when 'target_ids' is
written.

Link: https://lkml.kernel.org/r/20211229124029.23348-1-sj@kernel.org
Fixes: 4bc05954 ("mm/damon: implement a debugfs-based user space interface")
Signed-off-by: NSeongJae Park <sj@kernel.org>
Cc: <stable@vger.kernel.org>	[5.15+]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Currently, userfaultfd selftest for hugetlb as run from run_vmtests.sh
or any environment where there are 'just enough' hugetlb pages will
always fail with:

  testing events (fork, remap, remove):
		ERROR: UFFDIO_COPY error: -12 (errno=12, line=616)

The ENOMEM error code implies there are not enough hugetlb pages.
However, there are free hugetlb pages but they are all reserved.  There
is a basic problem with the way the test allocates hugetlb pages which
has existed since the test was originally written.

Due to the way 'cleanup' was done between different phases of the test,
this issue was masked until recently.  The issue was uncovered by commit
8ba6e864 ("userfaultfd/selftests: reinitialize test context in each
test").

For the hugetlb test, src and dst areas are allocated as PRIVATE
mappings of a hugetlb file.  This means that at mmap time, pages are
reserved for the src and dst areas.  At the start of event testing (and
other tests) the src area is populated which results in allocation of
huge pages to fill the area and consumption of reserves associated with
the area.  Then, a child is forked to fault in the dst area.  Note that
the dst area was allocated in the parent and hence the parent owns the
reserves associated with the mapping.  The child has normal access to
the dst area, but can not use the reserves created/owned by the parent.
Thus, if there are no other huge pages available allocation of a page
for the dst by the child will fail.

Fix by not creating reserves for the dst area.  In this way the child
can use free (non-reserved) pages.

Also, MAP_PRIVATE of a file only makes sense if you are interested in
the contents of the file before making a COW copy.  The test does not do
this.  So, just use MAP_ANONYMOUS | MAP_HUGETLB to create an anonymous
hugetlb mapping.  There is no need to create a hugetlb file in the
non-shared case.

Link: https://lkml.kernel.org/r/20211217172919.7861-1-mike.kravetz@oracle.comSigned-off-by: NMike Kravetz <mike.kravetz@oracle.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>