Current implementation keeps userspace input of CPUID configuration and
cpuid->nent even if kvm_update_cpuid() fails. Reset vcpu->arch.cpuid_nent
to 0 for the case of failure as a simple fix.

Besides, update the doc to explicitly state that if IOCTL SET_CPUID*
fail KVM gives no gurantee that previous valid CPUID configuration is
kept.
Signed-off-by: NXiaoyao Li <xiaoyao.li@intel.com>
Message-Id: <20200708065054.19713-2-xiaoyao.li@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Map "xen_nopvspin" to "nopvspin", fix stale description of "xen_nopvspin"
as we use qspinlock now.
Signed-off-by: NZhenzhong Duan <zhenzhong.duan@oracle.com>
Reviewed-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

There are cases where a guest tries to switch spinlocks to bare metal
behavior (e.g. by setting "xen_nopvspin" on XEN platform and
"hv_nopvspin" on HYPER_V).

That feature is missed on KVM, add a new parameter "nopvspin" to disable
PV spinlocks for KVM guest.

The new 'nopvspin' parameter will also replace Xen and Hyper-V specific
parameters in future patches.

Define variable nopvsin as global because it will be used in future
patches as above.
Signed-off-by: NZhenzhong Duan <zhenzhong.duan@oracle.com>
Reviewed-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krcmar <rkrcmar@redhat.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Wanpeng Li <wanpengli@tencent.com>
Cc: Jim Mattson <jmattson@google.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

More often than not, a failed VM-entry in an x86 production
environment is induced by a defective CPU. To help identify the bad
hardware, include the id of the last logical CPU to run a vCPU in the
information provided to userspace on a KVM exit for failed VM-entry or
for KVM internal errors not associated with emulation. The presence of
this additional information is indicated by a new capability,
KVM_CAP_LAST_CPU.
Signed-off-by: NJim Mattson <jmattson@google.com>
Reviewed-by: NOliver Upton <oupton@google.com>
Reviewed-by: NPeter Shier <pshier@google.com>
Message-Id: <20200603235623.245638-5-jmattson@google.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

I'm not convinced the script makes useful automaed help lines anyway,
but since we're trying to deprecate the use of "---help---" in Kconfig
files, let's fix the doc example code too.

See commit a7f7f624 ("treewide: replace '---help---' in Kconfig
files with 'help'")

Cc: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There's no need to specify 'maxItems' with the same value as the number
of entries in 'items'. A meta-schema update will catch future cases.

Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Anson Huang <Anson.Huang@nxp.com>
Cc: linux-clk@vger.kernel.org
Cc: linux-pwm@vger.kernel.org
Cc: linux-usb@vger.kernel.org
Reviewed-by: Stephen Boyd <sboyd@kernel.org> # clk
Acked-by: NThierry Reding <thierry.reding@gmail.com>
Signed-off-by: NRob Herring <robh@kernel.org>

In some rare cases, for input data over 32 KB, lzo-rle could encode two
different inputs to the same compressed representation, so that
decompression is then ambiguous (i.e.  data may be corrupted - although
zram is not affected because it operates over 4 KB pages).

This modifies the compressor without changing the decompressor or the
bitstream format, such that:

 - there is no change to how data produced by the old compressor is
   decompressed

 - an old decompressor will correctly decode data from the updated
   compressor

 - performance and compression ratio are not affected

 - we avoid introducing a new bitstream format

In testing over 12.8M real-world files totalling 903 GB, three files
were affected by this bug.  I also constructed 37M semi-random 64 KB
files totalling 2.27 TB, and saw no affected files.  Finally I tested
over files constructed to contain each of the ~1024 possible bad input
sequences; for all of these cases, updated lzo-rle worked correctly.

There is no significant impact to performance or compression ratio.
Signed-off-by: NDave Rodgman <dave.rodgman@arm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Dave Rodgman <dave.rodgman@arm.com>
Cc: Willy Tarreau <w@1wt.eu>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: Markus F.X.J. Oberhumer <markus@oberhumer.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Chao Yu <yuchao0@huawei.com>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/20200507100203.29785-1-dave.rodgman@arm.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The examples template is a 'simple-bus' with a size of 1 cell for
had between 2 and 4 cells which really only errors on I2C or SPI type
devices with a single cell.

The easiest fix in most cases is to change the 'reg' property to 1 cell
for address and size.

Cc: "Heiko Stübner" <heiko@sntech.de>
Cc: Ezequiel Garcia <ezequiel@collabora.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Cc: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Kishon Vijay Abraham I <kishon@ti.com>
Cc: Vinod Koul <vkoul@kernel.org>
Cc: Liam Girdwood <lgirdwood@gmail.com>
Cc: linux-rockchip@lists.infradead.org
Cc: linux-media@vger.kernel.org
Cc: linux-mtd@lists.infradead.org
Cc: netdev@vger.kernel.org
Cc: alsa-devel@alsa-project.org
Acked-by: NMark Brown <broonie@kernel.org>
Signed-off-by: NRob Herring <robh@kernel.org>

The QCom QMP PHY bindings have child nodes with translatable (MMIO)
addresses, so a 'ranges' property is required in the parent node.
Additionally, the examples default to 1 address and size cell, so let's
fix that, too.

Fixes: ccf51c1c ("dt-bindings: phy: qcom,qmp: Convert QMP PHY bindings to yaml")
Cc: Andy Gross <agross@kernel.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Kishon Vijay Abraham I <kishon@ti.com>
Cc: Vinod Koul <vkoul@kernel.org>
Cc: Manu Gautam <mgautam@codeaurora.org>
Cc: linux-arm-msm@vger.kernel.org
Signed-off-by: NRob Herring <robh@kernel.org>

Another round of 'allOf' removals that came in this cycle.

json-schema versions draft7 and earlier have a weird behavior in that
any keywords combined with a '$ref' are ignored (silently). The correct
form was to put a '$ref' under an 'allOf'. This behavior is now changed
in the 2019-09 json-schema spec and '$ref' can be mixed with other
keywords. The json-schema library doesn't yet support this, but the
tooling now does a fixup for this and either way works.

This has been a constant source of review comments, so let's change this
treewide so everyone copies the simpler syntax.
Signed-off-by: NRob Herring <robh@kernel.org>

Document change in required compiler version for KCSAN, and remove the
now redundant note about __no_kcsan and inlining problems with older
compilers.
Signed-off-by: NMarco Elver <elver@google.com>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: NWill Deacon <will@kernel.org>
Link: https://lkml.kernel.org/r/20200521142047.169334-8-elver@google.com

Remove description of non-existing v4l2_subdev.nevents and replace the
undefined flag V4L2_SUBDEV_USES_EVENTS by the correct flag
V4L2_SUBDEV_FL_HAS_EVENTS, which is already documented in v4l2_subdev.flags

Fixes: commit 02adb1cc ("[media] v4l: subdev: Events support")
Signed-off-by: NMichael Rodin <mrodin@de.adit-jv.com>
Signed-off-by: NHans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab+huawei@kernel.org>

A new file snuck into the tree after all existing documentation
was converted to RST. Convert sja1105's devlink info and move
it where the rest of the drivers are documented.
Signed-off-by: NJakub Kicinski <kuba@kernel.org>
Acked-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Tested-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We need an empty line before list stats, otherwise first point
will be smooshed into the paragraph. Inside tables text must
start at the same offset in the cell, otherwise sphinx thinks
it's a new indented block.

Documentation/networking/dsa/sja1105.rst:108: WARNING: Block quote ends without a blank line; unexpected unindent.
Documentation/networking/dsa/sja1105.rst:112: WARNING: Definition list ends without a blank line; unexpected unindent.
Documentation/networking/dsa/sja1105.rst:245: WARNING: Unexpected indentation.
Documentation/networking/dsa/sja1105.rst:246: WARNING: Block quote ends without a blank line; unexpected unindent.
Documentation/networking/dsa/sja1105.rst:253: WARNING: Unexpected indentation.
Documentation/networking/dsa/sja1105.rst:254: WARNING: Block quote ends without a blank line; unexpected unindent.

Fixes: a20bc43b ("docs: net: dsa: sja1105: document the best_effort_vlan_filtering option")
Signed-off-by: NJakub Kicinski <kuba@kernel.org>
Acked-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Sphinx appears to get upset at extra spaces at the end of a literal:

Documentation/networking/ethtool-netlink.rst:1032: WARNING: Inline literal start-string without end-string.
Documentation/networking/ethtool-netlink.rst:1034: WARNING: Inline literal start-string without end-string.
Documentation/networking/ethtool-netlink.rst:1036: WARNING: Inline literal start-string without end-string.
Documentation/networking/ethtool-netlink.rst:1089: WARNING: Inline literal start-string without end-string.
Documentation/networking/ethtool-netlink.rst:1091: WARNING: Inline literal start-string without end-string.
Documentation/networking/ethtool-netlink.rst:1093: WARNING: Inline literal start-string without end-string.

Fixes: f2bc8ad3 ("net: ethtool: Allow PHY cable test TDR data to configured")
Fixes: a331172b ("net: ethtool: Add attributes for cable test TDR data")
Signed-off-by: NJakub Kicinski <kuba@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The improved paragraph about line lengths contains a sentence with a
duplicate word: there is one "are" at the end of a line, followed by a
second one at the beginning of the next line.

Drop the first one, as that one is part of the longest line.

Fixes: bdc48fa1 ("checkpatch/coding-style: deprecate 80-column warning")
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The include file for input clock in the example was missing, breaking the
validation.
Signed-off-by: NLubomir Rintel <lkundrak@v3.sk>
Reported-by: NRob Herring <robh+dt@kernel.org>
Link: https://lore.kernel.org/r/20200605065258.567858-1-lkundrak@v3.skAcked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NStephen Boyd <sboyd@kernel.org>

Convert comments that reference mmap_sem to reference mmap_lock instead.

[akpm@linux-foundation.org: fix up linux-next leftovers]
[akpm@linux-foundation.org: s/lockaphore/lock/, per Vlastimil]
[akpm@linux-foundation.org: more linux-next fixups, per Michel]
Signed-off-by: NMichel Lespinasse <walken@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Reviewed-by: NVlastimil Babka <vbabka@suse.cz>
Reviewed-by: NDaniel Jordan <daniel.m.jordan@oracle.com>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Laurent Dufour <ldufour@linux.ibm.com>
Cc: Liam Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ying Han <yinghan@google.com>
Link: http://lkml.kernel.org/r/20200520052908.204642-13-walken@google.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Convert comments that reference old mmap_sem APIs to reference
corresponding new mmap locking APIs instead.
Signed-off-by: NMichel Lespinasse <walken@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Reviewed-by: NVlastimil Babka <vbabka@suse.cz>
Reviewed-by: NDavidlohr Bueso <dbueso@suse.de>
Reviewed-by: NDaniel Jordan <daniel.m.jordan@oracle.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Laurent Dufour <ldufour@linux.ibm.com>
Cc: Liam Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ying Han <yinghan@google.com>
Link: http://lkml.kernel.org/r/20200520052908.204642-12-walken@google.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch adds another way to attach bio flags to node writes.

Description:   Give a way to attach REQ_META|FUA to node writes
               given temperature-based bits. Now the bits indicate:
               *      REQ_META     |      REQ_FUA      |
               *    5 |    4 |   3 |    2 |    1 |   0 |
               * Cold | Warm | Hot | Cold | Warm | Hot |
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Starting from v4.19 commit 29ef680a ("memcg, oom: move out_of_memory
back to the charge path") cgroup oom killer is no longer invoked only
from page faults.  Now it implements the same semantics as global OOM
killer: allocation context invokes OOM killer and keeps retrying until
success.

[akpm@linux-foundation.org: fixes per Randy]
Signed-off-by: NKonstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Acked-by: NMichal Hocko <mhocko@suse.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Link: http://lkml.kernel.org/r/158894738928.208854.5244393925922074518.stgit@buzzSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Patch series "vhost, docs: convert to pin_user_pages(), new "case 5""

It recently became clear to me that there are some get_user_pages*()
callers that don't fit neatly into any of the four cases that are so far
listed in pin_user_pages.rst.  vhost.c is one of those.

Add a Case 5 to the documentation, and refer to that when converting
vhost.c.

Thanks to Jan Kara for helping me (again) in understanding the
interaction between get_user_pages() and page writeback [1].

This is based on today's mmotm, which has a nearby patch to
pin_user_pages.rst that rewords cases 3 and 4.

Note that I have only compile-tested the vhost.c patch, although that
does also include cross-compiling for a few other arches.  Any run-time
testing would be greatly appreciated.

[1] https://lore.kernel.org/r/20200529070343.GL14550@quack2.suse.cz

This patch (of 2):

There are four cases listed in pin_user_pages.rst.  These are intended
to help developers figure out whether to use get_user_pages*(), or
pin_user_pages*().  However, the four cases do not cover all the
situations.  For example, drivers/vhost/vhost.c has a "pin, write to
page, set page dirty, unpin" case.

Add a fifth case, to help explain that there is a general pattern that
requires pin_user_pages*() API calls.

[jhubbard@nvidia.com: v2]
  Link: http://lkml.kernel.org/r/20200601052633.853874-2-jhubbard@nvidia.comSigned-off-by: NJohn Hubbard <jhubbard@nvidia.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Jan Kara <jack@suse.cz>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Souptick Joarder <jrdr.linux@gmail.com>
Cc: "Michael S . Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Link: http://lkml.kernel.org/r/20200529234309.484480-1-jhubbard@nvidia.com
Link: http://lkml.kernel.org/r/20200529234309.484480-2-jhubbard@nvidia.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Update case 3 so that it covers the use of mmu notifiers, for hardware
that does, or does not have replayable page faults.

Also, elaborate case 4 slightly, as it was quite cryptic.
Signed-off-by: NJohn Hubbard <jhubbard@nvidia.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Jan Kara <jack@suse.cz>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Link: http://lkml.kernel.org/r/20200527194953.11130-1-jhubbard@nvidia.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Usually when the kernel reaches an oops condition, it's a point of no
return; in case not enough debug information is available in the kernel
splat, one of the last resorts would be to collect a kernel crash dump
and analyze it.  The problem with this approach is that in order to
collect the dump, a panic is required (to kexec-load the crash kernel).
When in an environment of multiple virtual machines, users may prefer to
try living with the oops, at least until being able to properly shutdown
their VMs / finish their important tasks.

This patch implements a way to collect a bit more debug details when an
oops event is reached, by printing all the CPUs backtraces through the
usage of NMIs (on architectures that support that).  The sysctl added
(and documented) here was called "oops_all_cpu_backtrace", and when set
will (as the name suggests) dump all CPUs backtraces.

Far from ideal, this may be the last option though for users that for
some reason cannot panic on oops.  Most of times oopses are clear enough
to indicate the kernel portion that must be investigated, but in virtual
environments it's possible to observe hypervisor/KVM issues that could
lead to oopses shown in other guests CPUs (like virtual APIC crashes).
This patch hence aims to help debug such complex issues without
resorting to kdump.
Signed-off-by: NGuilherme G. Piccoli <gpiccoli@canonical.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Reviewed-by: NKees Cook <keescook@chromium.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Matthew Wilcox <willy@infradead.org>
Link: http://lkml.kernel.org/r/20200327224116.21030-1-gpiccoli@canonical.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit 401c636a ("kernel/hung_task.c: show all hung tasks before
panic") introduced a change in that we started to show all CPUs
backtraces when a hung task is detected _and_ the sysctl/kernel
parameter "hung_task_panic" is set.  The idea is good, because usually
when observing deadlocks (that may lead to hung tasks), the culprit is
another task holding a lock and not necessarily the task detected as
hung.

The problem with this approach is that dumping backtraces is a slightly
expensive task, specially printing that on console (and specially in
many CPU machines, as servers commonly found nowadays).  So, users that
plan to collect a kdump to investigate the hung tasks and narrow down
the deadlock definitely don't need the CPUs backtrace on dmesg/console,
which will delay the panic and pollute the log (crash tool would easily
grab all CPUs traces with 'bt -a' command).

Also, there's the reciprocal scenario: some users may be interested in
seeing the CPUs backtraces but not have the system panic when a hung
task is detected.  The current approach hence is almost as embedding a
policy in the kernel, by forcing the CPUs backtraces' dump (only) on
hung_task_panic.

This patch decouples the panic event on hung task from the CPUs
backtraces dump, by creating (and documenting) a new sysctl called
"hung_task_all_cpu_backtrace", analog to the approach taken on soft/hard
lockups, that have both a panic and an "all_cpu_backtrace" sysctl to
allow individual control.  The new mechanism for dumping the CPUs
backtraces on hung task detection respects "hung_task_warnings" by not
dumping the traces in case there's no warnings left.
Signed-off-by: NGuilherme G. Piccoli <gpiccoli@canonical.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Reviewed-by: NKees Cook <keescook@chromium.org>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Link: http://lkml.kernel.org/r/20200327223646.20779-1-gpiccoli@canonical.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

After a recent change introduced by Vlastimil's series [0], kernel is
able now to handle sysctl parameters on kernel command line; also, the
series introduced a simple infrastructure to convert legacy boot
parameters (that duplicate sysctls) into sysctl aliases.

This patch converts the watchdog parameters softlockup_panic and
{hard,soft}lockup_all_cpu_backtrace to use the new alias infrastructure.
It fixes the documentation too, since the alias only accepts values 0 or
1, not the full range of integers.

We also took the opportunity here to improve the documentation of the
previously converted hung_task_panic (see the patch series [0]) and put
the alias table in alphabetical order.

[0] http://lkml.kernel.org/r/20200427180433.7029-1-vbabka@suse.czSigned-off-by: NGuilherme G. Piccoli <gpiccoli@canonical.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Cc: Kees Cook <keescook@chromium.org>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Link: http://lkml.kernel.org/r/20200507214624.21911-1-gpiccoli@canonical.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We can now handle sysctl parameters on kernel command line and have
infrastructure to convert legacy command line options that duplicate
sysctl to become a sysctl alias.

This patch converts the hung_task_panic parameter.  Note that the sysctl
handler is more strict and allows only 0 and 1, while the legacy
parameter allowed any non-zero value.  But there is little reason anyone
would not be using 1.
Signed-off-by: NVlastimil Babka <vbabka@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Reviewed-by: NKees Cook <keescook@chromium.org>
Acked-by: NMichal Hocko <mhocko@suse.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: "Eric W . Biederman" <ebiederm@xmission.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Guilherme G . Piccoli" <gpiccoli@canonical.com>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Ivan Teterevkov <ivan.teterevkov@nutanix.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20200427180433.7029-4-vbabka@suse.czSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Patch series "support setting sysctl parameters from kernel command line", v3.

This series adds support for something that seems like many people
always wanted but nobody added it yet, so here's the ability to set
sysctl parameters via kernel command line options in the form of
sysctl.vm.something=1

The important part is Patch 1.  The second, not so important part is an
attempt to clean up legacy one-off parameters that do the same thing as
a sysctl.  I don't want to remove them completely for compatibility
reasons, but with generic sysctl support the idea is to remove the
one-off param handlers and treat the parameters as aliases for the
sysctl variants.

I have identified several parameters that mention sysctl counterparts in
Documentation/admin-guide/kernel-parameters.txt but there might be more.
The conversion also has varying level of success:

 - numa_zonelist_order is converted in Patch 2 together with adding the
   necessary infrastructure. It's easy as it doesn't really do anything
   but warn on deprecated value these days.

 - hung_task_panic is converted in Patch 3, but there's a downside that
   now it only accepts 0 and 1, while previously it was any integer
   value

 - nmi_watchdog maps to two sysctls nmi_watchdog and hardlockup_panic,
   so there's no straighforward conversion possible

 - traceoff_on_warning is a flag without value and it would be required
   to handle that somehow in the conversion infractructure, which seems
   pointless for a single flag

This patch (of 5):

A recently proposed patch to add vm_swappiness command line parameter in
addition to existing sysctl [1] made me wonder why we don't have a
general support for passing sysctl parameters via command line.

Googling found only somebody else wondering the same [2], but I haven't
found any prior discussion with reasons why not to do this.

Settings the vm_swappiness issue aside (the underlying issue might be
solved in a different way), quick search of kernel-parameters.txt shows
there are already some that exist as both sysctl and kernel parameter -
hung_task_panic, nmi_watchdog, numa_zonelist_order, traceoff_on_warning.

A general mechanism would remove the need to add more of those one-offs
and might be handy in situations where configuration by e.g.
/etc/sysctl.d/ is impractical.

Hence, this patch adds a new parse_args() pass that looks for parameters
prefixed by 'sysctl.' and tries to interpret them as writes to the
corresponding sys/ files using an temporary in-kernel procfs mount.
This mechanism was suggested by Eric W.  Biederman [3], as it handles
all dynamically registered sysctl tables, even though we don't handle
modular sysctls.  Errors due to e.g.  invalid parameter name or value
are reported in the kernel log.

The processing is hooked right before the init process is loaded, as
some handlers might be more complicated than simple setters and might
need some subsystems to be initialized.  At the moment the init process
can be started and eventually execute a process writing to /proc/sys/
then it should be also fine to do that from the kernel.

Sysctls registered later on module load time are not set by this
mechanism - it's expected that in such scenarios, setting sysctl values
from userspace is practical enough.

[1] https://lore.kernel.org/r/BL0PR02MB560167492CA4094C91589930E9FC0@BL0PR02MB5601.namprd02.prod.outlook.com/
[2] https://unix.stackexchange.com/questions/558802/how-to-set-sysctl-using-kernel-command-line-parameter
[3] https://lore.kernel.org/r/87bloj2skm.fsf@x220.int.ebiederm.org/Signed-off-by: NVlastimil Babka <vbabka@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Reviewed-by: NLuis Chamberlain <mcgrof@kernel.org>
Reviewed-by: NMasami Hiramatsu <mhiramat@kernel.org>
Acked-by: NKees Cook <keescook@chromium.org>
Acked-by: NMichal Hocko <mhocko@suse.com>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Ivan Teterevkov <ivan.teterevkov@nutanix.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: "Eric W . Biederman" <ebiederm@xmission.com>
Cc: "Guilherme G . Piccoli" <gpiccoli@canonical.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Link: http://lkml.kernel.org/r/20200427180433.7029-1-vbabka@suse.cz
Link: http://lkml.kernel.org/r/20200427180433.7029-2-vbabka@suse.czSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Analogously to the introduction of panic_on_warn, this patch introduces
a kernel option named panic_on_taint in order to provide a simple and
generic way to stop execution and catch a coredump when the kernel gets
tainted by any given flag.

This is useful for debugging sessions as it avoids having to rebuild the
kernel to explicitly add calls to panic() into the code sites that
introduce the taint flags of interest.

For instance, if one is interested in proceeding with a post-mortem
analysis at the point a given code path is hitting a bad page (i.e.
unaccount_page_cache_page(), or slab_bug()), a coredump can be collected
by rebooting the kernel with 'panic_on_taint=0x20' amended to the
command line.

Another, perhaps less frequent, use for this option would be as a means
for assuring a security policy case where only a subset of taints, or no
single taint (in paranoid mode), is allowed for the running system.  The
optional switch 'nousertaint' is handy in this particular scenario, as
it will avoid userspace induced crashes by writes to sysctl interface
/proc/sys/kernel/tainted causing false positive hits for such policies.

[akpm@linux-foundation.org: tweak kernel-parameters.txt wording]
Suggested-by: NQian Cai <cai@lca.pw>
Signed-off-by: NRafael Aquini <aquini@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Reviewed-by: NLuis Chamberlain <mcgrof@kernel.org>
Cc: Dave Young <dyoung@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kees Cook <keescook@chromium.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Adrian Bunk <bunk@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Laura Abbott <labbott@redhat.com>
Cc: Jeff Mahoney <jeffm@suse.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Takashi Iwai <tiwai@suse.de>
Link: http://lkml.kernel.org/r/20200515175502.146720-1-aquini@redhat.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Instead of enabling dynamic debug globally with CONFIG_DYNAMIC_DEBUG,
CONFIG_DYNAMIC_DEBUG_CORE will only enable core function of dynamic
debug.  With the DYNAMIC_DEBUG_MODULE defined for any modules, dynamic
debug will be tied to them.

This is useful for people who only want to enable dynamic debug for
kernel modules without worrying about kernel image size and memory
consumption is increasing too much.

[orson.zhai@unisoc.com: v2]
  Link: http://lkml.kernel.org/r/1587408228-10861-1-git-send-email-orson.unisoc@gmail.comSigned-off-by: NOrson Zhai <orson.zhai@unisoc.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: NPetr Mladek <pmladek@suse.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Link: http://lkml.kernel.org/r/1586521984-5890-1-git-send-email-orson.unisoc@gmail.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Translate this commit to Korean:

  39323c64 ("smp_mb__{before,after}_atomic(): update Documentation")
Signed-off-by: NSeongJae Park <sjpark@amazon.de>
Reviewed-by: NYunjae Lee <lyj7694@gmail.com>
Link: https://lore.kernel.org/r/20200606083746.20869-1-sjpark@amazon.deSigned-off-by: NJonathan Corbet <corbet@lwn.net>

The devm_platform_get_and_ioremap_resource() should be documented in
devres.rst. Add the missing entry.
Signed-off-by: NDejin Zheng <zhengdejin5@gmail.com>
Link: https://lore.kernel.org/r/20200527144531.9376-1-zhengdejin5@gmail.comSigned-off-by: NJonathan Corbet <corbet@lwn.net>

Rationale:
Reduces attack surface on kernel devs opening the links for MITM
as HTTPS traffic is much harder to manipulate.

Deterministic algorithm:
For each file:
  For each line:
    If doesn't contain `\bxmlns\b`:
      For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`:
        If both the HTTP and HTTPS versions
        return 200 OK and serve the same content:
          Replace HTTP with HTTPS.
Signed-off-by: NAlexander A. Klimov <grandmaster@al2klimov.de>
Link: https://lore.kernel.org/r/20200526060544.25127-1-grandmaster@al2klimov.deSigned-off-by: NJonathan Corbet <corbet@lwn.net>

Documentation generation warns:

  it_IT/kernel-hacking/hacking.rst:
    WARNING: unknown document: ../core-api/symbol/namespaces

  it_IT/process/5.Posting.rst:
    WARNING: undefined label: it_email_clients

  it_IT/process/submitting-patches.rst:
    WARNING: undefined label: it_email_clients

  it_IT/process/howto.rst:
     WARNING: undefined label: it_managementstyle

Refer to English documentation, as Italian translation does not exist,
and add labels for Italian process documents to resolve label references.
Signed-off-by: NLukas Bulwahn <lukas.bulwahn@gmail.com>
Link: https://lore.kernel.org/r/20200531185618.7099-1-lukas.bulwahn@gmail.comSigned-off-by: NJonathan Corbet <corbet@lwn.net>

Documentation generation warns:

  Documentation/translations/zh_CN/filesystems/debugfs.rst:5:
  WARNING: undefined label: debugfs_index

Use doc reference for files rather than introducing a label to refer to.
This resolves the warning above.
Signed-off-by: NLukas Bulwahn <lukas.bulwahn@gmail.com>
Reviewed-by: NAlex Shi <alex.shi@linux.alibaba.com>
Link: https://lore.kernel.org/r/20200531183556.5751-1-lukas.bulwahn@gmail.comSigned-off-by: NJonathan Corbet <corbet@lwn.net>

The link to the Linux Foundation NDA program got broken in one of their
web-site thrashups; now that the information is back online, point to its
current location.  This should last until the next thrashup...
Reported-by: NLukas Bulwahn <lukas.bulwahn@gmail.com>
Reviewed-by: NLukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

Underline lengths should match the lengths of headings to avoid build
warnings with Sphinx.
Signed-off-by: NHeinrich Schuchardt <xypron.glpk@gmx.de>
Acked-by: NJulia Lawall <julia.lawall@inria.fr>
Link: https://lore.kernel.org/r/20200605030405.6479-1-xypron.glpk@gmx.deSigned-off-by: NJonathan Corbet <corbet@lwn.net>

Qualcomm APCS global block provides a bunch of generic properties which
are required in a device tree. Add YAML schema for these properties.
Reviewed-by: NRob Herring <robh@kernel.org>
Signed-off-by: NSivaprakash Murugesan <sivaprak@codeaurora.org>
Signed-off-by: NJassi Brar <jaswinder.singh@linaro.org>

In the files:

- regulatory.rst
- mac80211-injection.rst

the wiki url is still the old "wireless.kernel.org"
instead of the new "wireless.wiki.kernel.org"
Signed-off-by: NFlavio Suligoi <f.suligoi@asem.it>
Link: https://lore.kernel.org/r/20200605154112.16277-2-f.suligoi@asem.itSigned-off-by: NJohannes Berg <johannes.berg@intel.com>

Commit d503ac53 ("kbuild: rename LDFLAGS to KBUILD_LDFLAGS") missed
to update the documentation.
Signed-off-by: NMasahiro Yamada <masahiroy@kernel.org>