Instead of producing a too wide table, let's split it per
subsystem, and use a better notation in order to make easier
for the reader to identify how a feature is supported on
multiple architectures.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/9c3e8c813e8146c5c30e10fa75974f8fbfe6016a.1606748711.git.mchehab+huawei@kernel.orgSigned-off-by: Jonathan Corbet <corbet@lwn.net>

The Documentation/features contains a set of parseable files.
It is not worth converting them to ReST format, as they're
useful the way it is. It is, however, interesting to parse
them and produce output on different formats:

1) Output the contents of a feature in ReST format;

2) Output what features a given architecture supports;

3) Output a matrix with features x architectures.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/8b0c1ad06d689283a6d78c4ccd188a02c3acc0de.1606748711.git.mchehab+huawei@kernel.orgSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Document that /proc/PID/smaps shows PROT_MTE settings in VmFlags.
Support for this was introduced in

  commit 9f341931
  arm64: mte: Add PROT_MTE support to mmap() and mprotect()
Signed-off-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: linux-doc@vger.kernel.org
Link: https://lore.kernel.org/r/20201106101940.5777-1-szabolcs.nagy@arm.comSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Use full path to reference writing-schema.rst so that it becomes a
cross-reference.
Signed-off-by: Nícolas F. R. A. Prado <nfraprado@protonmail.com>
Link: https://lore.kernel.org/r/20201123121333.59274-1-nfraprado@protonmail.comSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Sphinx 3.1 introduced namespaces for C cross-references. With this,
each C domain type/function declaration is put inside the namespace that
was active at the time of its declaration.

Add support for automatic cross-referencing inside C namespaces by
checking whether the corresponding source file had a C namespace Sphinx
directive, and if so, try cross-referencing inside of it before going to
the global scope.

This assumes there's only one namespace (if any) per rst file.
Signed-off-by: Nícolas F. R. A. Prado <nfraprado@protonmail.com>
Link: https://lore.kernel.org/r/20201117021107.214704-1-nfraprado@protonmail.comSigned-off-by: Jonathan Corbet <corbet@lwn.net>

The feature lists don't match reality as of v5.10-rc4, update them
accordingly (by features-refresh.sh).
Signed-off-by: Wei Li <liwei391@huawei.com>
Link: https://lore.kernel.org/r/20201119022709.45843-1-liwei391@huawei.comSigned-off-by: Jonathan Corbet <corbet@lwn.net>

This is a Chinese translated version of
 Documentation/arm64/elf_hwcaps.rst
Signed-off-by: Bailu Lin <bailu.lin@vivo.com>
Reviewed-by: Alex Shi <alex.shi@linux.alibaba.com>
Link: https://lore.kernel.org/r/20201124023846.34826-1-bailu.lin@vivo.comSigned-off-by: Jonathan Corbet <corbet@lwn.net>

early_param memmap is only implemented on X86, MIPS and XTENSA. To avoid
wasting users’ time on trying this on platform like ARM, mark it clearly.
Signed-off-by: Barry Song <song.bao.hua@hisilicon.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Link: https://lore.kernel.org/r/20201128195121.2556-1-song.bao.hua@hisilicon.comSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation: dev-tools: kasan.rst: fix typos
Signed-off-by: Andrew Klychkov <andrew.a.klyckov@gmail.com>
Link: https://lore.kernel.org/r/20201129192928.GA5692@ak-VirtualBoxSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Translation for the following patches

commit 0aa78b10 ("Documentation/changes: Raise minimum supported binutils version to 2.23")
commit 7d717887 ("Documentation: include sign off for reverts")
commit 905705a8 ("docs: programming-languages: refresh blurb on clang support")
commit 5ff4aa70 ("docs: submitting-patches: use :doc: for references")
commit 030f066f ("docs: submitting-patches: describe preserving review/test tags")
commit 68e4cd17 ("docs: deprecated.rst: Add zero-length and one-element arrays")
commit 5429ef62 ("compiler/gcc: Raise minimum GCC version for kernel builds to 4.8")
commit 5b5bbb8c ("docs: process: Add an example for creating a fixes tag")
commit 858e6845 ("docs: dt: convert submitting-patches.txt to ReST format")
commit cca73e49 ("docs: Correct the release date of 5.2 stable")
commit c170f2eb ("docs: Document cross-referencing between documentation pages")
commit 7c8b9e30 ("kernel-doc: Update "cross-referencing from rST" section to use automarkup")
commit 27def953 ("docs: deprecated.rst: Expand str*cpy() replacement notes")
commit 17dca050 ("docs: deprecated.rst: Update zero-length/one-element arrays section")
commit 3519c4d6 ("Documentation: add minimum clang/llvm version")
commit 0bddd227 ("Documentation: update for gcc 4.9 requirement")
commit 9f364b60 ("submitting-patches.rst: presume git will be used")
commit 4ebdf7be ("Documentation/maintainer: rehome sign-off process")
commit 7433ff33 ("Documentation/process: expand plain-text advice")
commit eb45fb2f ("docs: process: Add cross-link to security-bugs")
commit bdc48fa1 ("checkpatch/coding-style: deprecate 80-column warning")
commit f67281a7 ("Documentation: process: step 2: Link to email list fixed")
Signed-off-by: Federico Vaga <federico.vaga@vaga.pv.it>
Link: https://lore.kernel.org/r/20201114083342.13935-1-federico.vaga@vaga.pv.itSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Add tmpfs to the index tree while adding tmppfs translation.
Signed-off-by: Wang Qing <wangqing@vivo.com>
Reviewed-by: Alex Shi <alex.shi@linux.alibaba.com>
Link: https://lore.kernel.org/r/1605509272-13770-1-git-send-email-wangqing@vivo.comSigned-off-by: Jonathan Corbet <corbet@lwn.net>

"to into" -> "into"
Reported-by: Sergei Shtylyov <sergei.shtylyov@gmail.com>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Acked-by: Daniel Thompson <daniel.thompson@linaro.org>
Link: https://lore.kernel.org/r/1605519767-25502-1-git-send-email-yangtiezhu@loongson.cnSigned-off-by: Jonathan Corbet <corbet@lwn.net>

This is a Chinese translated version of
 Documentation/arm64/perf.rst
Signed-off-by: Bailu Lin <bailu.lin@vivo.com>
Reviewed-by: Alex Shi <alex.shi@linux.alibaba.com>
Link: https://lore.kernel.org/r/20201030040541.8733-1-bailu.lin@vivo.comSigned-off-by: Jonathan Corbet <corbet@lwn.net>

The commit d38c8cfb ("scripts: kernel-doc: add support for typedef enum")
broke anonymous enum parsing. Restore it by relying on members rather than
its name.

Fixes: d38c8cfb ("scripts: kernel-doc: add support for typedef enum")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/20201102170637.36138-1-andriy.shevchenko@linux.intel.comSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Currently, all diagrams below "Before this framework, the layer is like"
and the text in between are rendered as one monospace text block.
Instead, each individual diagram should be a monospace text block.
Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Link: https://lore.kernel.org/r/20201107183902.1182809-1-j.neuschaefer@gmx.netSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Specifying the .rst extension doesn't cause any problems AFAICT, but
it's uncommon.
Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Link: https://lore.kernel.org/r/20201108132415.1789142-1-j.neuschaefer@gmx.netSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Add the current and cleaned Allwinner H616 datasheet and user manual.
Signed-off-by: Wilken Gottwalt <wilken.gottwalt@posteo.net>
Link: https://lore.kernel.org/r/20201108150104.GA66507@monster.powergraphx.localSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Format the shell commands and output in steps 6 and 8 as code blocks,
for consistency with the rest of the document.
Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Link: https://lore.kernel.org/r/20201108151005.1843666-1-j.neuschaefer@gmx.netSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Translate Documentation/filesystems/tmpfs.rst into Chinese.
Signed-off-by: Wang Qing <wangqing@vivo.com>

Changes in v4:
 - Modify as Alex required.

Changes in v3:
 - Fix patch format issue.
Reviewed-by: Alex Shi <alex.shi@linux.alibaba.com>
Link: https://lore.kernel.org/r/1604887072-12997-1-git-send-email-wangqing@vivo.comSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Remove all trailing whitespace from the ABI documentation.
Most of it was introduced during recent updates.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20201110144033.3278499-1-geert+renesas@glider.beSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Clarify how to pass the field width for bitmaps, and mention the helper
macros that are available to ease printing cpumask and nodemask.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20201110144121.3278667-1-geert+renesas@glider.beSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Provide basic ABI descriptions for the process attribute entries
that are shared between multiple Linux security modules.
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Link: https://lore.kernel.org/r/30c36660-3694-0c0d-d472-8f3b3ca4098e@schaufler-ca.comSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Currently, we do not have any documentation on commit reverts regarding
the requirement of Signed-off-by tag for it. This may be misleading to
the users.

Evaluating MISSING_SIGN_OFF checkpatch warnings on v4.13..v5.8 showed
that 4 out of 11 cases missing a sign-off are revert commits.

Add documentation regarding the same to document the community
consensus and let readers know.
Signed-off-by: Aditya Srivastava <yashsri421@gmail.com>
Link: https://lore.kernel.org/r/20201110174749.32068-1-yashsri421@gmail.comSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Merge tag 'driver-core-5.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core documentation fixes from Greg KH:
 "Some small Documentation fixes that were fallout from the larger
  documentation update we did in 5.10-rc2.

  Nothing major here at all, but all of these have been in linux-next
  and resolve build warnings when building the documentation files"

* tag 'driver-core-5.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  Documentation: remove mic/index from misc-devices/index.rst
  scripts: get_api.pl: Add sub-titles to ABI output
  scripts: get_abi.pl: Don't let ABI files to create subtitles
  docs: leds: index.rst: add a missing file
  docs: ABI: sysfs-class-net: fix a typo
  docs: ABI: sysfs-driver-dma-ioatdma: what starts with /sys

Pull tty/serial fixes from Greg KH:
 "Here are a small number of small tty and serial fixes for some
  reported problems for the tty core, vt code, and some serial drivers.

  They include fixes for:

   - a buggy and obsolete vt font ioctl removal

   - 8250_mtk serial baudrate runtime warnings

   - imx serial earlycon build configuration fix

   - txx9 serial driver error path cleanup issues

   - tty core fix in release_tty that can be triggered by trying to bind
     an invalid serial port name to a speakup console device

  Almost all of these have been in linux-next without any problems, the
  only one that hasn't, just deletes code :)"

* tag 'tty-5.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  vt: Disable KD_FONT_OP_COPY
  tty: fix crash in release_tty if tty->port is not set
  serial: txx9: add missing platform_driver_unregister() on error in serial_txx9_init
  tty: serial: imx: enable earlycon by default if IMX_SERIAL_CONSOLE is enabled
  serial: 8250_mtk: Fix uart_get_baud_rate warning

Pull USB fixes from Greg KH:
 "Here are some small USB fixes and new device ids:

   - USB gadget fixes for some reported issues

   - Fixes for the ever-troublesome apple fastcharge driver, hopefully
     we finally have it right.

   - More USB core quirks for odd devices

   - USB serial driver fixes for some long-standing issues that were
     recently found

   - some new USB serial driver device ids

  All have been in linux-next with no reported issues"

* tag 'usb-5.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  USB: apple-mfi-fastcharge: fix reference leak in apple_mfi_fc_set_property
  usb: mtu3: fix panic in mtu3_gadget_stop()
  USB: serial: option: add Telit FN980 composition 0x1055
  USB: serial: option: add LE910Cx compositions 0x1203, 0x1230, 0x1231
  USB: serial: cyberjack: fix write-URB completion race
  USB: Add NO_LPM quirk for Kingston flash drive
  USB: serial: option: add Quectel EC200T module support
  usb: raw-gadget: fix memory leak in gadget_setup
  usb: dwc2: Avoid leaving the error_debugfs label unused
  usb: dwc3: ep0: Fix delay status handling
  usb: gadget: fsl: fix null pointer checking
  usb: gadget: goku_udc: fix potential crashes in probe
  usb: dwc3: pci: add support for the Intel Alder Lake-S

current->group_leader->exit_signal may change during copy_process() if
current->real_parent exits.

Move the assignment inside tasklist_lock to avoid the race.
Signed-off-by: Eddy Wu <eddy_wu@trendmicro.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

It's buggy:

On Fri, Nov 06, 2020 at 10:30:08PM +0800, Minh Yuan wrote:
> We recently discovered a slab-out-of-bounds read in fbcon in the latest
> kernel ( v5.10-rc2 for now ).  The root cause of this vulnerability is that
> "fbcon_do_set_font" did not handle "vc->vc_font.data" and
> "vc->vc_font.height" correctly, and the patch
> <https://lkml.org/lkml/2020/9/27/223> for VT_RESIZEX can't handle this
> issue.
>
> Specifically, we use KD_FONT_OP_SET to set a small font.data for tty6, and
> use  KD_FONT_OP_SET again to set a large font.height for tty1. After that,
> we use KD_FONT_OP_COPY to assign tty6's vc_font.data to tty1's vc_font.data
> in "fbcon_do_set_font", while tty1 retains the original larger
> height. Obviously, this will cause an out-of-bounds read, because we can
> access a smaller vc_font.data with a larger vc_font.height.

Further there was only one user ever.
- Android's loadfont, busybox and console-tools only ever use OP_GET
  and OP_SET
- fbset documentation only mentions the kernel cmdline font: option,
  not anything else.
- systemd used OP_COPY before release 232 published in Nov 2016

Now unfortunately the crucial report seems to have gone down with
gmane, and the commit message doesn't say much. But the pull request
hints at OP_COPY being broken

https://github.com/systemd/systemd/pull/3651

So in other words, this never worked, and the only project which
foolishly every tried to use it, realized that rather quickly too.

Instead of trying to fix security issues here on dead code by adding
missing checks, fix the entire thing by removing the functionality.

Note that systemd code using the OP_COPY function ignored the return
value, so it doesn't matter what we're doing here really - just in
case a lone server somewhere happens to be extremely unlucky and
running an affected old version of systemd. The relevant code from
font_copy_to_all_vcs() in systemd was:

	/* copy font from active VT, where the font was uploaded to */
	cfo.op = KD_FONT_OP_COPY;
	cfo.height = vcs.v_active-1; /* tty1 == index 0 */
	(void) ioctl(vcfd, KDFONTOP, &cfo);

Note this just disables the ioctl, garbage collecting the now unused
callbacks is left for -next.

v2: Tetsuo found the old mail, which allowed me to find it on another
archive. Add the link too.
Acked-by: Peilin Ye <yepeilin.cs@gmail.com>
Reported-by: Minh Yuan <yuanmingbuaa@gmail.com>
References: https://lists.freedesktop.org/archives/systemd-devel/2016-June/036935.html
References: https://github.com/systemd/systemd/pull/3651
Cc: Greg KH <greg@kroah.com>
Cc: Peilin Ye <yepeilin.cs@gmail.com>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://lore.kernel.org/r/20201108153806.3140315-1-daniel.vetter@ffwll.chSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Pull xfs fixes from Darrick Wong:

 - Fix an uninitialized struct problem

 - Fix an iomap problem zeroing unwritten EOF blocks

 - Fix some clumsy error handling when writeback fails on filesystems
   with blocksize < pagesize

 - Fix a retry loop not resetting loop variables properly

 - Fix scrub flagging rtinherit inodes on a non-rt fs, since the kernel
   actually does permit that combination

 - Fix excessive page cache flushing when unsharing part of a file

* tag 'xfs-5.10-fixes-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  xfs: only flush the unshared range in xfs_reflink_unshare
  xfs: fix scrub flagging rtinherit even if there is no rt device
  xfs: fix missing CoW blocks writeback conversion retry
  iomap: clean up writeback state logic on writepage error
  iomap: support partial page discard on writeback block mapping failure
  xfs: flush new eof page on truncate to avoid post-eof corruption
  xfs: set xefi_discard when creating a deferred agfl free log intent item

Merge procfs splice read fixes from Christoph Hellwig:
 "Greg reported a problem due to the fact that Android tests use procfs
  files to test splice, which stopped working with the changes for
  set_fs() removal.

  This series adds read_iter support for seq_file, and uses those for
  various proc files using seq_file to restore splice read support"

[ Side note: Christoph initially had a scripted "move everything over"
  patch, which looks fine, but I personally would prefer us to actively
  discourage splice() on random files.  So this does just the minimal
  basic core set of proc file op conversions.

  For completeness, and in case people care, that script was

     sed -i -e 's/\.proc_read\(\s*=\s*\)seq_read/\.proc_read_iter\1seq_read_iter/g'

  but I'll wait and see if somebody has a strong argument for using
  splice on random small /proc files before I'd run it on the whole
  kernel.   - Linus ]

* emailed patches from Christoph Hellwig <hch@lst.de>:
  proc "seq files": switch to ->read_iter
  proc "single files": switch to ->read_iter
  proc/stat: switch to ->read_iter
  proc/cpuinfo: switch to ->read_iter
  proc: wire up generic_file_splice_read for iter ops
  seq_file: add seq_read_iter

Pull x86 fixes from Thomas Gleixner:
 "A set of x86 fixes:

   - Use SYM_FUNC_START_WEAK in the mem* ASM functions instead of a
     combination of .weak and SYM_FUNC_START_LOCAL which makes LLVMs
     integrated assembler upset

   - Correct the mitigation selection logic which prevented the related
     prctl to work correctly

   - Make the UV5 hubless system work correctly by fixing up the
     malformed table entries and adding the missing ones"

* tag 'x86-urgent-2020-11-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/platform/uv: Recognize UV5 hubless system identifier
  x86/platform/uv: Remove spaces from OEM IDs
  x86/platform/uv: Fix missing OEM_TABLE_ID
  x86/speculation: Allow IBPB to be conditionally enabled on CPUs with always-on STIBP
  x86/lib: Change .weak to SYM_FUNC_START_WEAK for arch/x86/lib/mem*_64.S

Pull perf fix from Thomas Gleixner:
 "A single fix for the perf core plugging a memory leak in the address
  filter parser"

* tag 'perf-urgent-2020-11-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/core: Fix a memory leak in perf_event_parse_addr_filter()

Pull futex fix from Thomas Gleixner:
 "A single fix for the futex code where an intermediate state in the
  underlying RT mutex was not handled correctly and triggering a BUG()
  instead of treating it as another variant of retry condition"

* tag 'locking-urgent-2020-11-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  futex: Handle transient "ownerless" rtmutex state correctly

Pull irq fixes from Thomas Gleixner:
 "A set of fixes for interrupt chip drivers:

   - Fix the fallout of the IPI as interrupt conversion in Kconfig and
     the BCM2836 interrupt chip driver

   - Fixes for interrupt affinity setting and the handling of
     hierarchical irq domains in the SiFive PLIC driver

   - Make the unmapped event handling in the TI SCI driver work
     correctly

   - A few minor fixes and cleanups in various chip drivers and Kconfig"

* tag 'irq-urgent-2020-11-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  dt-bindings: irqchip: ti, sci-inta: Fix diagram indentation for unmapped events
  irqchip/ti-sci-inta: Add support for unmapped event handling
  dt-bindings: irqchip: ti, sci-inta: Update for unmapped event handling
  irqchip/renesas-intc-irqpin: Merge irlm_bit and needs_irlm
  irqchip/sifive-plic: Fix chip_data access within a hierarchy
  irqchip/sifive-plic: Fix broken irq_set_affinity() callback
  irqchip/stm32-exti: Add all LP timer exti direct events support
  irqchip/bcm2836: Fix missing __init annotation
  irqchip/mips: Drop selection of IRQ_DOMAIN_HIERARCHY
  irqchip/mst: Make mst_intc_of_init static
  irqchip/mst: MST_IRQ should depend on ARCH_MEDIATEK or ARCH_MSTARV7
  genirq: Let GENERIC_IRQ_IPI select IRQ_DOMAIN_HIERARCHY

Pull entry code fix from Thomas Gleixner:
 "A single fix for the generic entry code to correct the wrong
  assumption that the lockdep interrupt state needs not to be
  established before calling the RCU check"

* tag 'core-urgent-2020-11-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  entry: Fix the incorrect ordering of lockdep and RCU check

Pull powerpc fixes from Michael Ellerman:

 - fix miscompilation with GCC 4.9 by using asm_goto_volatile for put_user()

 - fix for an RCU splat at boot caused by a recent lockdep change

 - fix for a possible deadlock in our EEH debugfs code

 - several fixes for handling of _PAGE_ACCESSED on 32-bit platforms

 - build fix when CONFIG_NUMA=n

Thanks to Andreas Schwab, Christophe Leroy, Oliver O'Halloran, Qian Cai,
and Scott Cheloha.

* tag 'powerpc-5.10-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/numa: Fix build when CONFIG_NUMA=n
  powerpc/8xx: Manage _PAGE_ACCESSED through APG bits in L1 entry
  powerpc/8xx: Always fault when _PAGE_ACCESSED is not set
  powerpc/40x: Always fault when _PAGE_ACCESSED is not set
  powerpc/603: Always fault when _PAGE_ACCESSED is not set
  powerpc: Use asm_goto_volatile for put_user()
  powerpc/smp: Call rcu_cpu_starting() earlier
  powerpc/eeh_cache: Fix a possible debugfs deadlock

Pull block fixes from Jens Axboe:

 - NVMe pull request from Christoph:
    - revert a nvme_queue size optimization (Keith Bush)
    - fabrics timeout races fixes (Chao Leng and Sagi Grimberg)"

 - null_blk zone locking fix (Damien)

* tag 'block-5.10-2020-11-07' of git://git.kernel.dk/linux-block:
  null_blk: Fix scheduling in atomic with zoned mode
  nvme-tcp: avoid repeated request completion
  nvme-rdma: avoid repeated request completion
  nvme-tcp: avoid race between time out and tear down
  nvme-rdma: avoid race between time out and tear down
  nvme: introduce nvme_sync_io_queues
  Revert "nvme-pci: remove last_sq_tail"

Pull io_uring fixes from Jens Axboe:
 "A set of fixes for io_uring:

   - SQPOLL cancelation fixes

   - Two fixes for the io_identity COW

   - Cancelation overflow fix (Pavel)

   - Drain request cancelation fix (Pavel)

   - Link timeout race fix (Pavel)"

* tag 'io_uring-5.10-2020-11-07' of git://git.kernel.dk/linux-block:
  io_uring: fix link lookup racing with link timeout
  io_uring: use correct pointer for io_uring_show_cred()
  io_uring: don't forget to task-cancel drained reqs
  io_uring: fix overflowed cancel w/ linked ->files
  io_uring: drop req/tctx io_identity separately
  io_uring: ensure consistent view of original task ->mm from SQPOLL
  io_uring: properly handle SQPOLL request cancelations
  io-wq: cancel request if it's asking for files and we don't have them

Gratian managed to trigger the BUG_ON(!newowner) in fixup_pi_state_owner().
This is one possible chain of events leading to this:

Task Prio       Operation
T1   120	lock(F)
T2   120	lock(F)   -> blocks (top waiter)
T3   50 (RT)	lock(F)   -> boosts T1 and blocks (new top waiter)
XX   		timeout/  -> wakes T2
		signal
T1   50		unlock(F) -> wakes T3 (rtmutex->owner == NULL, waiter bit is set)
T2   120	cleanup   -> try_to_take_mutex() fails because T3 is the top waiter
     			     and the lower priority T2 cannot steal the lock.
     			  -> fixup_pi_state_owner() sees newowner == NULL -> BUG_ON()

The comment states that this is invalid and rt_mutex_real_owner() must
return a non NULL owner when the trylock failed, but in case of a queued
and woken up waiter rt_mutex_real_owner() == NULL is a valid transient
state. The higher priority waiter has simply not yet managed to take over
the rtmutex.

The BUG_ON() is therefore wrong and this is just another retry condition in
fixup_pi_state_owner().

Drop the locks, so that T3 can make progress, and then try the fixup again.

Gratian provided a great analysis, traces and a reproducer. The analysis is
to the point, but it confused the hell out of that tglx dude who had to
page in all the futex horrors again. Condensed version is above.

[ tglx: Wrote comment and changelog ]

Fixes: c1e2f0ea ("futex: Avoid violating the 10th rule of futex")
Reported-by: Gratian Crisan <gratian.crisan@ni.com>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/87a6w6x7bb.fsf@ni.com
Link: https://lore.kernel.org/r/87sg9pkvf7.fsf@nanos.tec.linutronix.de