Add the mds=full,nosmt cmdline option.  This is like mds=full, but with
SMT disabled if the CPU is vulnerable.
Signed-off-by: NJosh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NTyler Hicks <tyhicks@canonical.com>
Acked-by: NJiri Kosina <jkosina@suse.cz>

Add the initial MDS vulnerability documentation.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NJon Masters <jcm@redhat.com>

Move L!TF to a separate directory so the MDS stuff can be added at the
side. Otherwise the all hardware vulnerabilites have their own top level
entry. Should have done that right away.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: NJon Masters <jcm@redhat.com>

In virtualized environments it can happen that the host has the microcode
update which utilizes the VERW instruction to clear CPU buffers, but the
hypervisor is not yet updated to expose the X86_FEATURE_MD_CLEAR CPUID bit
to guests.

Introduce an internal mitigation mode VMWERV which enables the invocation
of the CPU buffer clearing even if X86_FEATURE_MD_CLEAR is not set. If the
system has no updated microcode this results in a pointless execution of
the VERW instruction wasting a few CPU cycles. If the microcode is updated,
but not exposed to a guest then the CPU buffers will be cleared.

That said: Virtual Machines Will Eventually Receive Vaccine
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NBorislav Petkov <bp@suse.de>
Reviewed-by: NJon Masters <jcm@redhat.com>
Tested-by: NJon Masters <jcm@redhat.com>

Add the sysfs reporting file for MDS. It exposes the vulnerability and
mitigation state similar to the existing files for the other speculative
hardware vulnerabilities.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: NBorislav Petkov <bp@suse.de>
Reviewed-by: NJon Masters <jcm@redhat.com>
Tested-by: NJon Masters <jcm@redhat.com>

Now that the mitigations are in place, add a command line parameter to
control the mitigation, a mitigation selector function and a SMT update
mechanism.

This is the minimal straight forward initial implementation which just
provides an always on/off mode. The command line parameter is:

  mds=[full|off]

This is consistent with the existing mitigations for other speculative
hardware vulnerabilities.

The idle invocation is dynamically updated according to the SMT state of
the system similar to the dynamic update of the STIBP mitigation. The idle
mitigation is limited to CPUs which are only affected by MSBDS and not any
other variant, because the other variants cannot be mitigated on SMT
enabled systems.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NBorislav Petkov <bp@suse.de>
Reviewed-by: NJon Masters <jcm@redhat.com>
Tested-by: NJon Masters <jcm@redhat.com>

Add a static key which controls the invocation of the CPU buffer clear
mechanism on idle entry. This is independent of other MDS mitigations
because the idle entry invocation to mitigate the potential leakage due to
store buffer repartitioning is only necessary on SMT systems.

Add the actual invocations to the different halt/mwait variants which
covers all usage sites. mwaitx is not patched as it's not available on
Intel CPUs.

The buffer clear is only invoked before entering the C-State to prevent
that stale data from the idling CPU is spilled to the Hyper-Thread sibling
after the Store buffer got repartitioned and all entries are available to
the non idle sibling.

When coming out of idle the store buffer is partitioned again so each
sibling has half of it available. Now CPU which returned from idle could be
speculatively exposed to contents of the sibling, but the buffers are
flushed either on exit to user space or on VMENTER.

When later on conditional buffer clearing is implemented on top of this,
then there is no action required either because before returning to user
space the context switch will set the condition flag which causes a flush
on the return to user path.

Note, that the buffer clearing on idle is only sensible on CPUs which are
solely affected by MSBDS and not any other variant of MDS because the other
MDS variants cannot be mitigated when SMT is enabled, so the buffer
clearing on idle would be a window dressing exercise.

This intentionally does not handle the case in the acpi/processor_idle
driver which uses the legacy IO port interface for C-State transitions for
two reasons:

 - The acpi/processor_idle driver was replaced by the intel_idle driver
   almost a decade ago. Anything Nehalem upwards supports it and defaults
   to that new driver.

 - The legacy IO port interface is likely to be used on older and therefore
   unaffected CPUs or on systems which do not receive microcode updates
   anymore, so there is no point in adding that.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NBorislav Petkov <bp@suse.de>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: NFrederic Weisbecker <frederic@kernel.org>
Reviewed-by: NJon Masters <jcm@redhat.com>
Tested-by: NJon Masters <jcm@redhat.com>

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

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

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

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

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

Documentation also recommends to use a writable data segment selector:

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

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

This callback was removed some time ago, also remove the documentation.

Fixes: 1b6dd556 ("net: dsa: Remove prepare phase for FDB")
Signed-off-by: NHauke Mehrtens <hauke@hauke-m.de>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Update the section about switchdev drivers having to implement a
switchdev_port_attr_get() function to return
SWITCHDEV_ATTR_ID_PORT_PARENT_ID since that is no longer valid after
commit bccb3025 ("net: Get rid of
SWITCHDEV_ATTR_ID_PORT_PARENT_ID").

Fixes: bccb3025 ("net: Get rid of SWITCHDEV_ATTR_ID_PORT_PARENT_ID")
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

MSG_ZEROCOPY implementation for UDP was merged in v5.0,
6e360f73 ("Merge branch 'udp-msg_zerocopy'").
Signed-off-by: NPetr Vorel <pvorel@suse.cz>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As linux-5.0.x is coming up soon, the documentation should match,
in particular the README.rst file, so change all 4.x references
accordingly. There was a mix of lowercase and uppercase X here,
which I changed to using lowercase consistently.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

Netlink has moved from bitmasks to group numbers long ago.
Signed-off-by: NJouke Witteveen <j.witteveen@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix a grammatical error in the dentry-state text and clarify the usage
of negative dentries.

Fixes: af0c9af1 ("fs/dcache: Track & report number of negative dentries")
Signed-off-by: NWaiman Long <longman@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

"Resource Control" is a very broad term for this CPU feature, and a term
that is also associated with containers, cgroups etc. This can easily
cause confusion.

Make the user prompt more specific. Match the config symbol name.

 [ bp: In the future, the corresponding ARM arch-specific code will be
   under ARM_CPU_RESCTRL and the arch-agnostic bits will be carved out
   under the CPU_RESCTRL umbrella symbol. ]
Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Cc: Babu Moger <Babu.Moger@amd.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Morse <james.morse@arm.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: linux-doc@vger.kernel.org
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Pu Wen <puwen@hygon.cn>
Cc: Reinette Chatre <reinette.chatre@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190130195621.GA30653@cmpxchg.org

The current dentry number tracking code doesn't distinguish between
positive & negative dentries.  It just reports the total number of
dentries in the LRU lists.

As excessive number of negative dentries can have an impact on system
performance, it will be wise to track the number of positive and
negative dentries separately.

This patch adds tracking for the total number of negative dentries in
the system LRU lists and reports it in the 5th field in the
/proc/sys/fs/dentry-state file.  The number, however, does not include
negative dentries that are in flight but not in the LRU yet as well as
those in the shrinker lists which are on the way out anyway.

The number of positive dentries in the LRU lists can be roughly found by
subtracting the number of negative dentries from the unused count.

Matthew Wilcox had confirmed that since the introduction of the
dentry_stat structure in 2.1.60, the dummy array was there, probably for
future extension.  They were not replacements of pre-existing fields.
So no sane applications that read the value of /proc/sys/fs/dentry-state
will do dummy thing if the last 2 fields of the sysctl parameter are not
zero.  IOW, it will be safe to use one of the dummy array entry for
negative dentry count.
Signed-off-by: NWaiman Long <longman@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit 765b6a98 ("iommu/vt-d: Enumerate the scalable
mode capability") enables VT-d scalable mode if hardware
advertises the capability. As we will bring up different
features and use cases to upstream in different patch
series, it will leave some intermediate kernel versions
which support partial features. Hence, end user might run
into problems when they use such kernels on bare metals
or virtualization environments.

This leaves scalable mode default off and end users could
turn it on with "intel-iommu=sm_on" only when they have
clear ideas about which scalable features are supported
in the kernel.

Cc: Liu Yi L <yi.l.liu@intel.com>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Suggested-by: NAshok Raj <ashok.raj@intel.com>
Suggested-by: NKevin Tian <kevin.tian@intel.com>
Signed-off-by: NLu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

The mlxreg-io for the merge window assumed 4.21 as the next kernel
version. Replace 4.21 with 5.0.
Signed-off-by: NDarren Hart (VMware) <dvhart@infradead.org>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>

Each GPU core only uses one interrupt so we don't to look up
an interrupt by name and thereby we don't need interrupt-names.
Signed-off-by: NJordan Crouse <jcrouse@codeaurora.org>
Reviewed-by: NRob Herring <robh@kernel.org>
Signed-off-by: NRob Clark <robdclark@gmail.com>

Turns out this is not such a great idea. Once the SP clock is disabled,
it's not sufficient to just enable in order to bring the SP core back up.

It seems that the kernel has no business managing this clock. Just let
the firmware keep it enabled.

This reverts commit ed22cee9.

Link: https://lore.kernel.org/lkml/154783267051.169631.3197836544646625747@swboyd.mtv.corp.google.com/Signed-off-by: NLubomir Rintel <lkundrak@v3.sk>
Acked-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: NStephen Boyd <sboyd@kernel.org>

On in tree builds, subsequent builds will incorrectly include
the intermediate file 'processed-schema.yaml' with the input schema
files resulting in a build error. Update the find command to ignore
processed-schema.yaml.
Signed-off-by: NRob Herring <robh@kernel.org>

Fix "reference to nonexisting document" warnings.

Fixes: b255e500 ("net: documentation: build a directory structure for drivers")
Signed-off-by: NOtto Sabart <ottosabart@seberm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net_tstamp.h is an UAPI header, so it was moved under include/uapi.
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix few trivial language typos in bindings.
Signed-off-by: NKrzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: NRob Herring <robh@kernel.org>

The cp110-system-controller0.txt file was renamed to
cp110-system-controller.txt.

Fixes: 4aa54969 ("dt-bindings: cp110: rename cp110 syscon file")
Signed-off-by: NOtto Sabart <ottosabart@seberm.com>
Signed-off-by: NRob Herring <robh@kernel.org>

A command line option is much more flexible than a config option and
the supporting code is small. Gets rid of #ifdefs in the code too...
Suggested-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: NPeter Rosin <peda@axentia.se>
Signed-off-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

add document for below counters:
TcpEstabResets
TcpAttemptFails
TcpOutRsts
TcpExtTCPSACKDiscard
TcpExtTCPDSACKIgnoredOld
TcpExtTCPDSACKIgnoredNoUndo
TcpExtTCPSackShifted
TcpExtTCPSackMerged
TcpExtTCPSackShiftFallback
TcpExtTCPWantZeroWindowAdv
TcpExtTCPToZeroWindowAdv
TcpExtTCPFromZeroWindowAdv
TcpExtDelayedACKs
TcpExtDelayedACKLocked
TcpExtDelayedACKLost
TcpExtTCPLossProbes
TcpExtTCPLossProbeRecovery
Signed-off-by: Nyupeng <yupeng0921@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The changes introduced to allow rxrpc calls to be retried creates an issue
when it comes to refcounting afs_call structs.  The problem is that when
rxrpc_send_data() queues the last packet for an asynchronous call, the
following sequence can occur:

 (1) The notify_end_tx callback is invoked which causes the state in the
     afs_call to be changed from AFS_CALL_CL_REQUESTING or
     AFS_CALL_SV_REPLYING.

 (2) afs_deliver_to_call() can then process event notifications from rxrpc
     on the async_work queue.

 (3) Delivery of events, such as an abort from the server, can cause the
     afs_call state to be changed to AFS_CALL_COMPLETE on async_work.

 (4) For an asynchronous call, afs_process_async_call() notes that the call
     is complete and tried to clean up all the refs on async_work.

 (5) rxrpc_send_data() might return the amount of data transferred
     (success) or an error - which could in turn reflect a local error or a
     received error.

Synchronising the clean up after rxrpc_kernel_send_data() returns an error
with the asynchronous cleanup is then tricky to get right.

Mostly revert commit c038a58c.  The two API
functions the original commit added aren't currently used.  This makes
rxrpc_kernel_send_data() always return successfully if it queued the data
it was given.

Note that this doesn't affect synchronous calls since their Rx notification
function merely pokes a wait queue and does not refcounting.  The
asynchronous call notification function *has* to do refcounting and pass a
ref over the work item to avoid the need to sync the workqueue in call
cleanup.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The primecell.txt and cpus.txt files were converted into YAML. This
patch updates old references with new ones.

Fixes: d3c207ee ("dt-bindings: arm: Convert primecell binding to json-schema")
Fixes: 672951cb ("dt-bindings: arm: Convert cpu binding to json-schema")
Signed-off-by: NOtto Sabart <ottosabart@seberm.com>
Signed-off-by: NRob Herring <robh@kernel.org>

A pair of rather trivial ones.
Signed-off-by: NLubomir Rintel <lkundrak@v3.sk>
Signed-off-by: NRob Herring <robh@kernel.org>

The URL of [api-spec] in Documentation/virtual/kvm/amd-memory-encryption.rst
is no longer valid, replaced space with underscore.
Signed-off-by: NChristophe de Dinechin <dinechin@redhat.com>
Reviewed-by: NBrijesh Singh <brijesh.singh@amd.com>
Signed-off-by: NRadim Krčmář <rkrcmar@redhat.com>

Of the tunables available for the bfq I/O scheduler, the only one
missing from the documentation in 'Documentation/block/bfq-iosched.txt'
is slice_idle_us. Add this tunable to the documentation and a short
explanation of its purpose.
Acked-by: NPaolo Valente <paolo.valente@linaro.org>
Signed-off-by: NJohn Pittman <jpittman@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Old cpuidle/sysfs.txt file was replaced in aa5eee35. So, refer to
an updated file.

Fixes: aa5eee35 (Documentation: admin-guide: PM: Add cpuidle document)
Signed-off-by: NOtto Sabart <ottosabart@seberm.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

CONFIG_RESCTRL is too generic. The final goal is to have a generic
option called like this which is selected by the arch-specific ones
CONFIG_X86_RESCTRL and CONFIG_ARM64_RESCTRL. The generic one will
cover the resctrl filesystem and other generic and shared bits of
functionality.
Signed-off-by: NBorislav Petkov <bp@suse.de>
Suggested-by: NIngo Molnar <mingo@kernel.org>
Requested-by: NLinus Torvalds <torvalds@linux-foundation.org>
Cc: Babu Moger <babu.moger@amd.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: James Morse <james.morse@arm.com>
Cc: Reinette Chatre <reinette.chatre@intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: x86@kernel.org
Link: http://lkml.kernel.org/r/20190108171401.GC12235@zn.tnic

This patch includes some fixes and cleanup for idle-page writeback.

1. writeback_limit interface

Now writeback_limit interface is rather conusing.  For example, once
writeback limit budget is exausted, admin can see 0 from
/sys/block/zramX/writeback_limit which is same semantic with disable
writeback_limit at this moment.  IOW, admin cannot tell that zero came
from disable writeback limit or exausted writeback limit.

To make the interface clear, let's sepatate enable of writeback limit to
another knob - /sys/block/zram0/writeback_limit_enable

* before:
  while true :
    # to re-enable writeback limit once previous one is used up
    echo 0 > /sys/block/zram0/writeback_limit
    echo $((200<<20)) > /sys/block/zram0/writeback_limit
    ..
    .. # used up the writeback limit budget

* new
  # To enable writeback limit, from the beginning, admin should
  # enable it.
  echo $((200<<20)) > /sys/block/zram0/writeback_limit
  echo 1 > /sys/block/zram/0/writeback_limit_enable
  while true :
    echo $((200<<20)) > /sys/block/zram0/writeback_limit
    ..
    .. # used up the writeback limit budget

It's much strightforward.

2. fix condition check idle/huge writeback mode check

The mode in writeback_store is not bit opeartion any more so no need to
use bit operations.  Furthermore, current condition check is broken in
that it does writeback every pages regardless of huge/idle.

3. clean up idle_store

No need to use goto.

[minchan@kernel.org: missed spin_lock_init]
  Link: http://lkml.kernel.org/r/20190103001601.GA255139@google.com
Link: http://lkml.kernel.org/r/20181224033529.19450-1-minchan@kernel.orgSigned-off-by: NMinchan Kim <minchan@kernel.org>
Suggested-by: NJohn Dias <joaodias@google.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: John Dias <joaodias@google.com>
Cc: Srinivas Paladugu <srnvs@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We are getting rid of the "raw" BUS_ATTR() macro, so fix up the
documentation to not refer to it anymore.

Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Update the bpf_design_QA.rst to also reflect recent changes in
6c4fc209 ("bpf: remove useless version check for prog load").
Suggested-by: NQuentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>

Add compatible strings for reset control of AHCI core implemented in
UniPhier SoCs. The reset control belongs to AHCI glue layer.
Signed-off-by: NKunihiko Hayashi <hayashi.kunihiko@socionext.com>
Reviewed-by: NRob Herring <robh@kernel.org>
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

Replace the expression of "USB3 glue layer" with the glue layer of the
generic peripherals to allow other devices to use it. The reset control
belongs to this glue layer.
Signed-off-by: NKunihiko Hayashi <hayashi.kunihiko@socionext.com>
Reviewed-by: NRob Herring <robh@kernel.org>
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>