The in-kernel afs filesystem ignores ctime because the AFS fileserver
protocol doesn't support ctimes.  This, however, causes various xfstests to
fail.

Work around this by:

 (1) Setting ctime to attr->ia_ctime in afs_setattr().

 (2) Not ignoring ATTR_MTIME_SET, ATTR_TIMES_SET and ATTR_TOUCH settings.

 (3) Setting the ctime from the server mtime when on the target file when
     creating a hard link to it.

 (4) Setting the ctime on directories from their revised mtimes when
     renaming/moving a file.

Found by the generic/221 and generic/309 xfstests.
Signed-off-by: David Howells <dhowells@redhat.com>

When doing a partial writeback, afs_write_back_from_locked_page() may
generate an FS.StoreData RPC request that writes out part of a file when a
file has been constructed from pieces by doing seek, write, seek, write,
... as is done by ld.

The FS.StoreData RPC is given the current i_size as the file length, but
the server basically ignores it unless the data length is 0 (in which case
it's just a truncate operation).  The revised file length returned in the
result of the RPC may then not reflect what we suggested - and this leads
to i_size getting moved backwards - which causes issues later.

Fix the client to take account of this by ignoring the returned file size
unless the data version number jumped unexpectedly - in which case we're
going to have to clear the pagecache and reload anyway.

This can be observed when doing a kernel build on an AFS mount.  The
following pair of commands produce the issue:

  ld -m elf_x86_64 -z max-page-size=0x200000 --emit-relocs \
      -T arch/x86/realmode/rm/realmode.lds \
      arch/x86/realmode/rm/header.o \
      arch/x86/realmode/rm/trampoline_64.o \
      arch/x86/realmode/rm/stack.o \
      arch/x86/realmode/rm/reboot.o \
      -o arch/x86/realmode/rm/realmode.elf
  arch/x86/tools/relocs --realmode \
      arch/x86/realmode/rm/realmode.elf \
      >arch/x86/realmode/rm/realmode.relocs

This results in the latter giving:

	Cannot read ELF section headers 0/18: Success

as the realmode.elf file got corrupted.

The sequence of events can also be driven with:

	xfs_io -t -f \
		-c "pwrite -S 0x58 0 0x58" \
		-c "pwrite -S 0x59 10000 1000" \
		-c "close" \
		/afs/example.com/scratch/a

Fixes: 31143d5d ("AFS: implement basic file write support")
Signed-off-by: David Howells <dhowells@redhat.com>

Fix afs_write_end() to change i_size under vnode->cb_lock rather than
->wb_lock so that it doesn't race with afs_vnode_commit_status() and
afs_getattr().

The ->wb_lock is only meant to guard access to ->wb_keys which isn't
accessed by that piece of code.

Fixes: 4343d008 ("afs: Get rid of the afs_writeback record")
Signed-off-by: David Howells <dhowells@redhat.com>

The mtime on an inode needs to be updated when a write is made into an
mmap'ed section.  There are three ways in which this could be done: update
it when page_mkwrite is called, update it when a page is changed from dirty
to writeback or leave it to the server and fix the mtime up from the reply
to the StoreData RPC.

Found with the generic/215 xfstest.

Fixes: 1cf7a151 ("afs: Implement shared-writeable mmap")
Signed-off-by: David Howells <dhowells@redhat.com>

Pull SafeSetID update from Micah Morton:
 "Add additional LSM hooks for SafeSetID

  SafeSetID is capable of making allow/deny decisions for set*uid calls
  on a system, and we want to add similar functionality for set*gid
  calls.

  The work to do that is not yet complete, so probably won't make it in
  for v5.8, but we are looking to get this simple patch in for v5.8
  since we have it ready.

  We are planning on the rest of the work for extending the SafeSetID
  LSM being merged during the v5.9 merge window"

* tag 'LSM-add-setgid-hook-5.8-author-fix' of git://github.com/micah-morton/linux:
  security: Add LSM hooks to set*gid syscalls

The SafeSetID LSM uses the security_task_fix_setuid hook to filter
set*uid() syscalls according to its configured security policy. In
preparation for adding analagous support in the LSM for set*gid()
syscalls, we add the requisite hook here. Tested by putting print
statements in the security_task_fix_setgid hook and seeing them get hit
during kernel boot.
Signed-off-by: Thomas Cedeno <thomascedeno@google.com>
Signed-off-by: Micah Morton <mortonm@chromium.org>

Pull btrfs updates from David Sterba:
 "This reverts the direct io port to iomap infrastructure of btrfs
  merged in the first pull request. We found problems in invalidate page
  that don't seem to be fixable as regressions or without changing iomap
  code that would not affect other filesystems.

  There are four reverts in total, but three of them are followup
  cleanups needed to revert a43a67a2 cleanly. The result is the
  buffer head based implementation of direct io.

  Reverts are not great, but under current circumstances I don't see
  better options"

* tag 'for-5.8-part2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  Revert "btrfs: switch to iomap_dio_rw() for dio"
  Revert "fs: remove dio_end_io()"
  Revert "btrfs: remove BTRFS_INODE_READDIO_NEED_LOCK"
  Revert "btrfs: split btrfs_direct_IO to read and write part"

Pull networking fixes from David Miller:

 1) Fix cfg80211 deadlock, from Johannes Berg.

 2) RXRPC fails to send norigications, from David Howells.

 3) MPTCP RM_ADDR parsing has an off by one pointer error, fix from
    Geliang Tang.

 4) Fix crash when using MSG_PEEK with sockmap, from Anny Hu.

 5) The ucc_geth driver needs __netdev_watchdog_up exported, from
    Valentin Longchamp.

 6) Fix hashtable memory leak in dccp, from Wang Hai.

 7) Fix how nexthops are marked as FDB nexthops, from David Ahern.

 8) Fix mptcp races between shutdown and recvmsg, from Paolo Abeni.

 9) Fix crashes in tipc_disc_rcv(), from Tuong Lien.

10) Fix link speed reporting in iavf driver, from Brett Creeley.

11) When a channel is used for XSK and then reused again later for XSK,
    we forget to clear out the relevant data structures in mlx5 which
    causes all kinds of problems. Fix from Maxim Mikityanskiy.

12) Fix memory leak in genetlink, from Cong Wang.

13) Disallow sockmap attachments to UDP sockets, it simply won't work.
    From Lorenz Bauer.

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (83 commits)
  net: ethernet: ti: ale: fix allmulti for nu type ale
  net: ethernet: ti: am65-cpsw-nuss: fix ale parameters init
  net: atm: Remove the error message according to the atomic context
  bpf: Undo internal BPF_PROBE_MEM in BPF insns dump
  libbpf: Support pre-initializing .bss global variables
  tools/bpftool: Fix skeleton codegen
  bpf: Fix memlock accounting for sock_hash
  bpf: sockmap: Don't attach programs to UDP sockets
  bpf: tcp: Recv() should return 0 when the peer socket is closed
  ibmvnic: Flush existing work items before device removal
  genetlink: clean up family attributes allocations
  net: ipa: header pad field only valid for AP->modem endpoint
  net: ipa: program upper nibbles of sequencer type
  net: ipa: fix modem LAN RX endpoint id
  net: ipa: program metadata mask differently
  ionic: add pcie_print_link_status
  rxrpc: Fix race between incoming ACK parser and retransmitter
  net/mlx5: E-Switch, Fix some error pointer dereferences
  net/mlx5: Don't fail driver on failure to create debugfs
  net/mlx5e: CT: Fix ipv6 nat header rewrite actions
  ...

This reverts commit a43a67a2.

This patch reverts the main part of switching direct io implementation
to iomap infrastructure. There's a problem in invalidate page that
couldn't be solved as regression in this development cycle.

The problem occurs when buffered and direct io are mixed, and the ranges
overlap. Although this is not recommended, filesystems implement
measures or fallbacks to make it somehow work. In this case, fallback to
buffered IO would be an option for btrfs (this already happens when
direct io is done on compressed data), but the change would be needed in
the iomap code, bringing new semantics to other filesystems.

Another problem arises when again the buffered and direct ios are mixed,
invalidation fails, then -EIO is set on the mapping and fsync will fail,
though there's no real error.

There have been discussions how to fix that, but revert seems to be the
least intrusive option.

Link: https://lore.kernel.org/linux-btrfs/20200528192103.xm45qoxqmkw7i5yl@fiona/Signed-off-by: David Sterba <dsterba@suse.com>

On AM65xx MCU CPSW2G NUSS and 66AK2E/L NUSS allmulti setting does not allow
unregistered mcast packets to pass.

This happens, because ALE VLAN entries on these SoCs do not contain port
masks for reg/unreg mcast packets, but instead store indexes of
ALE_VLAN_MASK_MUXx_REG registers which intended for store port masks for
reg/unreg mcast packets.
This path was missed by commit 9d1f6447 ("net: ethernet: ti: ale: fix
seeing unreg mcast packets with promisc and allmulti disabled").

Hence, fix it by taking into account ALE type in cpsw_ale_set_allmulti().

Fixes: 9d1f6447 ("net: ethernet: ti: ale: fix seeing unreg mcast packets with promisc and allmulti disabled")
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The ALE parameters structure is created on stack, so it has to be reset
before passing to cpsw_ale_create() to avoid garbage values.

Fixes: 93a76530 ("net: ethernet: ti: introduce am65x/j721e gigabit eth subsystem driver")
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Alexei Starovoitov says:

====================
pull-request: bpf 2020-06-12

The following pull-request contains BPF updates for your *net* tree.

We've added 26 non-merge commits during the last 10 day(s) which contain
a total of 27 files changed, 348 insertions(+), 93 deletions(-).

The main changes are:

1) sock_hash accounting fix, from Andrey.

2) libbpf fix and probe_mem sanitizing, from Andrii.

3) sock_hash fixes, from Jakub.

4) devmap_val fix, from Jesper.

5) load_bytes_relative fix, from YiFei.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Looking into the context (atomic!) and the error message should be dropped.
Signed-off-by: Liao Pingfang <liao.pingfang@zte.com.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pull more cifs updates from Steve French:
 "12 cifs/smb3 fixes, 2 for stable.

   - add support for idsfromsid on create and chgrp/chown allowing
     ability to save owner information more naturally for some workloads

   - improve query info (getattr) when SMB3.1.1 posix extensions are
     negotiated by using new query info level"

* tag '5.8-rc-smb3-fixes-part2' of git://git.samba.org/sfrench/cifs-2.6:
  smb3: Add debug message for new file creation with idsfromsid mount option
  cifs: fix chown and chgrp when idsfromsid mount option enabled
  smb3: allow uid and gid owners to be set on create with idsfromsid mount option
  smb311: Add tracepoints for new compound posix query info
  smb311: add support for using info level for posix extensions query
  smb311: Add support for lookup with posix extensions query info
  smb311: Add support for SMB311 query info (non-compounded)
  SMB311: Add support for query info using posix extensions (level 100)
  smb3: add indatalen that can be a non-zero value to calculation of credit charge in smb2 ioctl
  smb3: fix typo in mount options displayed in /proc/mounts
  cifs: Add get_security_type_str function to return sec type.
  smb3: extend fscache mount volume coherency check

Let's keep "git status" happy and quiet.

Fixes: 9762dc14 ("samples: add binderfs sample program
Fixes: fca5e949 ("samples: binderfs: really compile this sample and fix build issues")
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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: Linus Torvalds <torvalds@linux-foundation.org>

Pull more Kbuild updates from Masahiro Yamada:

 - fix build rules in binderfs sample

 - fix build errors when Kbuild recurses to the top Makefile

 - covert '---help---' in Kconfig to 'help'

* tag 'kbuild-v5.8-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  treewide: replace '---help---' in Kconfig files with 'help'
  kbuild: fix broken builds because of GZIP,BZIP2,LZOP variables
  samples: binderfs: really compile this sample and fix build issues

Pull more SCSI updates from James Bottomley:
 "This is the set of changes collected since just before the merge
  window opened. It's mostly minor fixes in drivers.

  The one non-driver set is the three optical disk (sr) changes where
  two are error path fixes and one is a helper conversion.

  The big driver change is the hpsa compat_alloc_userspace rework by Al
  so he can kill the remaining user. This has been tested and acked by
  the maintainer"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (21 commits)
  scsi: acornscsi: Fix an error handling path in acornscsi_probe()
  scsi: storvsc: Remove memset before memory freeing in storvsc_suspend()
  scsi: cxlflash: Remove an unnecessary NULL check
  scsi: ibmvscsi: Don't send host info in adapter info MAD after LPM
  scsi: sr: Fix sr_probe() missing deallocate of device minor
  scsi: sr: Fix sr_probe() missing mutex_destroy
  scsi: st: Convert convert get_user_pages() --> pin_user_pages()
  scsi: target: Rename target_setup_cmd_from_cdb() to target_cmd_parse_cdb()
  scsi: target: Fix NULL pointer dereference
  scsi: target: Initialize LUN in transport_init_se_cmd()
  scsi: target: Factor out a new helper, target_cmd_init_cdb()
  scsi: hpsa: hpsa_ioctl(): Tidy up a bit
  scsi: hpsa: Get rid of compat_alloc_user_space()
  scsi: hpsa: Don't bother with vmalloc for BIG_IOCTL_Command_struct
  scsi: hpsa: Lift {BIG_,}IOCTL_Command_struct copy{in,out} into hpsa_ioctl()
  scsi: ufs: Remove redundant urgent_bkop_lvl initialization
  scsi: ufs: Don't update urgent bkops level when toggling auto bkops
  scsi: qedf: Remove redundant initialization of variable rc
  scsi: mpt3sas: Fix memset() in non-RDPQ mode
  scsi: iscsi: Fix reference count leak in iscsi_boot_create_kobj
  ...

Pull i2c updates from Wolfram Sang:
 "I2C has quite some patches for you this time. I hope it is the move to
  per-driver-maintainers which is now showing results. We will see.

  The big news is two new drivers (Nuvoton NPCM and Qualcomm CCI),
  larger refactoring of the Designware, Tegra, and PXA drivers, the
  Cadence driver supports being a slave now, and there is support to
  instanciate SPD eeproms for well-known cases (which will be
  user-visible because the i801 driver supports it), and some
  devm_platform_ioremap_resource() conversions which blow up the
  diffstat.

  Note that I applied the Nuvoton driver quite late, so some minor fixup
  patches arrived during the merge window. I chose to apply them right
  away because they were trivial"

* 'i2c/for-5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (109 commits)
  i2c: Drop stray comma in MODULE_AUTHOR statements
  i2c: npcm7xx: npcm_i2caddr[] can be static
  MAINTAINERS: npcm7xx: Add maintainer for Nuvoton NPCM BMC
  i2c: npcm7xx: Fix a couple of error codes in probe
  i2c: icy: Fix build with CONFIG_AMIGA_PCMCIA=n
  i2c: npcm7xx: Remove unnecessary parentheses
  i2c: npcm7xx: Add support for slave mode for Nuvoton
  i2c: npcm7xx: Add Nuvoton NPCM I2C controller driver
  dt-bindings: i2c: npcm7xx: add NPCM I2C controller
  i2c: pxa: don't error out if there's no pinctrl
  i2c: add 'single-master' property to generic bindings
  i2c: designware: Add Baikal-T1 System I2C support
  i2c: designware: Move reg-space remapping into a dedicated function
  i2c: designware: Retrieve quirk flags as early as possible
  i2c: designware: Convert driver to using regmap API
  i2c: designware: Discard Cherry Trail model flag
  i2c: designware: Add Baytrail sem config DW I2C platform dependency
  i2c: designware: slave: Set DW I2C core module dependency
  i2c: designware: Use `-y` to build multi-object modules
  dt-bindings: i2c: dw: Add Baikal-T1 SoC I2C controller
  ...

Pull more media updates from Mauro Carvalho Chehab:

 - a set of atomisp patches. They remove several abstraction layers, and
   fixes clang and gcc warnings (that were hidden via some macros that
   were disabling 4 or 5 types of warnings there). There are also some
   important fixes and sensor auto-detection on newer BIOSes via ACPI
   _DCM tables.

 - some fixes

* tag 'media/v5.8-2' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (95 commits)
  media: rkvdec: Fix H264 scaling list order
  media: v4l2-ctrls: Unset correct HEVC loop filter flag
  media: videobuf2-dma-contig: fix bad kfree in vb2_dma_contig_clear_max_seg_size
  media: v4l2-subdev.rst: correct information about v4l2 events
  media: s5p-mfc: Properly handle dma_parms for the allocated devices
  media: medium: cec: Make MEDIA_CEC_SUPPORT default to n if !MEDIA_SUPPORT
  media: cedrus: Implement runtime PM
  media: cedrus: Program output format during each run
  media: atomisp: improve ACPI/DMI detection logs
  media: Revert "media: atomisp: add Asus Transform T101HA ACPI vars"
  media: Revert "media: atomisp: Add some ACPI detection info"
  media: atomisp: improve sensor detection code to use _DSM table
  media: atomisp: get rid of an iomem abstraction layer
  media: atomisp: get rid of a string_support.h abstraction layer
  media: atomisp: use strscpy() instead of less secure variants
  media: atomisp: set DFS to MAX if sensor doesn't report fps
  media: atomisp: use different dfs failed messages
  media: atomisp: change the detection of ISP2401 at runtime
  media: atomisp: use macros from intel-family.h
  media: atomisp: don't set hpll_freq twice with different values
  ...

Pull libnvdimm updates from Dan Williams:
 "Small collection of cleanups to rework usage of ->queuedata and the
  GUID api"

* tag 'libnvdimm-for-5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  nvdimm/pmem: stop using ->queuedata
  nvdimm/btt: stop using ->queuedata
  nvdimm/blk: stop using ->queuedata
  libnvdimm: Replace guid_copy() with import_guid() where it makes sense

Let's keep "git status" happy and quiet.

Fixes: f5b5a164 ("Add sample notification program")
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull iomap fix from Darrick Wong:
 "A single iomap bug fix for a variable type mistake on 32-bit
  architectures, fixing an integer overflow problem in the unshare
  actor"

* tag 'iomap-5.8-merge-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  iomap: Fix unsharing of an extent >2GB on a 32-bit machine

Pull xfs fix from Darrick Wong:
 "We've settled down into the bugfix phase; this one fixes a resource
  leak on an error bailout path"

* tag 'xfs-5.8-merge-9' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  xfs: Add the missed xfs_perag_put() for xfs_ifree_cluster()

Pull 9p update from Dominique Martinet:
 "Another very quiet cycle... Only one commit: increase the size of the
  ring used for xen transport"

* tag '9p-for-5.8' of git://github.com/martinetd/linux:
  9p/xen: increase XEN_9PFS_RING_ORDER

Pull powerpc fix from Michael Ellerman:
 "One fix for a recent change which broke nested KVM guests on Power9.

  Thanks to Alexey Kardashevskiy"

* tag 'powerpc-5.8-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  KVM: PPC: Fix nested guest RC bits update

Pull ARM fixes from Russell King:

 - fix for "hex" Kconfig default to use 0x0 rather than 0 to allow these
   to be removed from defconfigs

 - fix from Ard Biesheuvel for EFI HYP mode booting

* tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm:
  ARM: 8985/1: efi/decompressor: deal with HYP mode boot gracefully
  ARM: 8984/1: Kconfig: set default ZBOOT_ROM_TEXT/BSS value to 0x0

Pull OpenRISC update from Stafford Horne:
 "One patch found wile I was getting the glibc port ready: fix issue
  with clone TLS arg getting overwritten"

* tag 'for-linus' of git://github.com/openrisc/linux:
  openrisc: Fix issue with argument clobbering for clone/fork

Pull alpha updates from Matt Turner:
 "A few changes for alpha. They're mostly small janitorial fixes but
  there's also a build fix and most notably a patch from Mikulas that
  fixes a hang on boot on the Avanti platform, which required quite a
  bit of work and review"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mattst88/alpha:
  alpha: Fix build around srm_sysrq_reboot_op
  alpha: c_next should increase position index
  alpha: Replace sg++ with sg = sg_next(sg)
  alpha: fix memory barriers so that they conform to the specification
  alpha: remove unneeded semicolon in sys_eiger.c
  alpha: remove unneeded semicolon in osf_sys.c
  alpha: Replace strncmp with str_has_prefix
  alpha: fix rtc port ranges
  alpha: Kconfig: pedantic formatting

Pull x86 RAS updates from Thomas Gleixner:
 "RAS updates from Borislav Petkov:

   - Unmap a whole guest page if an MCE is encountered in it to avoid
     follow-on MCEs leading to the guest crashing, by Tony Luck.

     This change collided with the entry changes and the merge
     resolution would have been rather unpleasant. To avoid that the
     entry branch was merged in before applying this. The resulting code
     did not change over the rebase.

   - AMD MCE error thresholding machinery cleanup and hotplug
     sanitization, by Thomas Gleixner.

   - Change the MCE notifiers to denote whether they have handled the
     error and not break the chain early by returning NOTIFY_STOP, thus
     giving the opportunity for the later handlers in the chain to see
     it. By Tony Luck.

   - Add AMD family 0x17, models 0x60-6f support, by Alexander Monakov.

   - Last but not least, the usual round of fixes and improvements"

* tag 'ras-core-2020-06-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
  x86/mce/dev-mcelog: Fix -Wstringop-truncation warning about strncpy()
  x86/{mce,mm}: Unmap the entire page if the whole page is affected and poisoned
  EDAC/amd64: Add AMD family 17h model 60h PCI IDs
  hwmon: (k10temp) Add AMD family 17h model 60h PCI match
  x86/amd_nb: Add AMD family 17h model 60h PCI IDs
  x86/mcelog: Add compat_ioctl for 32-bit mcelog support
  x86/mce: Drop bogus comment about mce.kflags
  x86/mce: Fixup exception only for the correct MCEs
  EDAC: Drop the EDAC report status checks
  x86/mce: Add mce=print_all option
  x86/mce: Change default MCE logger to check mce->kflags
  x86/mce: Fix all mce notifiers to update the mce->kflags bitmask
  x86/mce: Add a struct mce.kflags field
  x86/mce: Convert the CEC to use the MCE notifier
  x86/mce: Rename "first" function as "early"
  x86/mce/amd, edac: Remove report_gart_errors
  x86/mce/amd: Make threshold bank setting hotplug robust
  x86/mce/amd: Cleanup threshold device remove path
  x86/mce/amd: Straighten CPU hotplug path
  x86/mce/amd: Sanitize thresholding device creation hotplug path
  ...

Pull x86 entry updates from Thomas Gleixner:
 "The x86 entry, exception and interrupt code rework

  This all started about 6 month ago with the attempt to move the Posix
  CPU timer heavy lifting out of the timer interrupt code and just have
  lockless quick checks in that code path. Trivial 5 patches.

  This unearthed an inconsistency in the KVM handling of task work and
  the review requested to move all of this into generic code so other
  architectures can share.

  Valid request and solved with another 25 patches but those unearthed
  inconsistencies vs. RCU and instrumentation.

  Digging into this made it obvious that there are quite some
  inconsistencies vs. instrumentation in general. The int3 text poke
  handling in particular was completely unprotected and with the batched
  update of trace events even more likely to expose to endless int3
  recursion.

  In parallel the RCU implications of instrumenting fragile entry code
  came up in several discussions.

  The conclusion of the x86 maintainer team was to go all the way and
  make the protection against any form of instrumentation of fragile and
  dangerous code pathes enforcable and verifiable by tooling.

  A first batch of preparatory work hit mainline with commit
  d5f744f9 ("Pull x86 entry code updates from Thomas Gleixner")

  That (almost) full solution introduced a new code section
  '.noinstr.text' into which all code which needs to be protected from
  instrumentation of all sorts goes into. Any call into instrumentable
  code out of this section has to be annotated. objtool has support to
  validate this.

  Kprobes now excludes this section fully which also prevents BPF from
  fiddling with it and all 'noinstr' annotated functions also keep
  ftrace off. The section, kprobes and objtool changes are already
  merged.

  The major changes coming with this are:

    - Preparatory cleanups

    - Annotating of relevant functions to move them into the
      noinstr.text section or enforcing inlining by marking them
      __always_inline so the compiler cannot misplace or instrument
      them.

    - Splitting and simplifying the idtentry macro maze so that it is
      now clearly separated into simple exception entries and the more
      interesting ones which use interrupt stacks and have the paranoid
      handling vs. CR3 and GS.

    - Move quite some of the low level ASM functionality into C code:

       - enter_from and exit to user space handling. The ASM code now
         calls into C after doing the really necessary ASM handling and
         the return path goes back out without bells and whistels in
         ASM.

       - exception entry/exit got the equivivalent treatment

       - move all IRQ tracepoints from ASM to C so they can be placed as
         appropriate which is especially important for the int3
         recursion issue.

    - Consolidate the declaration and definition of entry points between
      32 and 64 bit. They share a common header and macros now.

    - Remove the extra device interrupt entry maze and just use the
      regular exception entry code.

    - All ASM entry points except NMI are now generated from the shared
      header file and the corresponding macros in the 32 and 64 bit
      entry ASM.

    - The C code entry points are consolidated as well with the help of
      DEFINE_IDTENTRY*() macros. This allows to ensure at one central
      point that all corresponding entry points share the same
      semantics. The actual function body for most entry points is in an
      instrumentable and sane state.

      There are special macros for the more sensitive entry points, e.g.
      INT3 and of course the nasty paranoid #NMI, #MCE, #DB and #DF.
      They allow to put the whole entry instrumentation and RCU handling
      into safe places instead of the previous pray that it is correct
      approach.

    - The INT3 text poke handling is now completely isolated and the
      recursion issue banned. Aside of the entry rework this required
      other isolation work, e.g. the ability to force inline bsearch.

    - Prevent #DB on fragile entry code, entry relevant memory and
      disable it on NMI, #MC entry, which allowed to get rid of the
      nested #DB IST stack shifting hackery.

    - A few other cleanups and enhancements which have been made
      possible through this and already merged changes, e.g.
      consolidating and further restricting the IDT code so the IDT
      table becomes RO after init which removes yet another popular
      attack vector

    - About 680 lines of ASM maze are gone.

  There are a few open issues:

   - An escape out of the noinstr section in the MCE handler which needs
     some more thought but under the aspect that MCE is a complete
     trainwreck by design and the propability to survive it is low, this
     was not high on the priority list.

   - Paravirtualization

     When PV is enabled then objtool complains about a bunch of indirect
     calls out of the noinstr section. There are a few straight forward
     ways to fix this, but the other issues vs. general correctness were
     more pressing than parawitz.

   - KVM

     KVM is inconsistent as well. Patches have been posted, but they
     have not yet been commented on or picked up by the KVM folks.

   - IDLE

     Pretty much the same problems can be found in the low level idle
     code especially the parts where RCU stopped watching. This was
     beyond the scope of the more obvious and exposable problems and is
     on the todo list.

  The lesson learned from this brain melting exercise to morph the
  evolved code base into something which can be validated and understood
  is that once again the violation of the most important engineering
  principle "correctness first" has caused quite a few people to spend
  valuable time on problems which could have been avoided in the first
  place. The "features first" tinkering mindset really has to stop.

  With that I want to say thanks to everyone involved in contributing to
  this effort. Special thanks go to the following people (alphabetical
  order): Alexandre Chartre, Andy Lutomirski, Borislav Petkov, Brian
  Gerst, Frederic Weisbecker, Josh Poimboeuf, Juergen Gross, Lai
  Jiangshan, Macro Elver, Paolo Bonzin,i Paul McKenney, Peter Zijlstra,
  Vitaly Kuznetsov, and Will Deacon"

* tag 'x86-entry-2020-06-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (142 commits)
  x86/entry: Force rcu_irq_enter() when in idle task
  x86/entry: Make NMI use IDTENTRY_RAW
  x86/entry: Treat BUG/WARN as NMI-like entries
  x86/entry: Unbreak __irqentry_text_start/end magic
  x86/entry: __always_inline CR2 for noinstr
  lockdep: __always_inline more for noinstr
  x86/entry: Re-order #DB handler to avoid *SAN instrumentation
  x86/entry: __always_inline arch_atomic_* for noinstr
  x86/entry: __always_inline irqflags for noinstr
  x86/entry: __always_inline debugreg for noinstr
  x86/idt: Consolidate idt functionality
  x86/idt: Cleanup trap_init()
  x86/idt: Use proper constants for table size
  x86/idt: Add comments about early #PF handling
  x86/idt: Mark init only functions __init
  x86/entry: Rename trace_hardirqs_off_prepare()
  x86/entry: Clarify irq_{enter,exit}_rcu()
  x86/entry: Remove DBn stacks
  x86/entry: Remove debug IDT frobbing
  x86/entry: Optimize local_db_save() for virt
  ...

Since commit 84af7a61 ("checkpatch: kconfig: prefer 'help' over
'---help---'"), the number of '---help---' has been gradually
decreasing, but there are still more than 2400 instances.

This commit finishes the conversion. While I touched the lines,
I also fixed the indentation.

There are a variety of indentation styles found.

  a) 4 spaces + '---help---'
  b) 7 spaces + '---help---'
  c) 8 spaces + '---help---'
  d) 1 space + 1 tab + '---help---'
  e) 1 tab + '---help---'    (correct indentation)
  f) 1 tab + 1 space + '---help---'
  g) 1 tab + 2 spaces + '---help---'

In order to convert all of them to 1 tab + 'help', I ran the
following commend:

  $ find . -name 'Kconfig*' | xargs sed -i 's/^[[:space:]]*---help---/\thelp/'
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Merge tag 'notifications-20200601' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

Pull notification queue from David Howells:
 "This adds a general notification queue concept and adds an event
  source for keys/keyrings, such as linking and unlinking keys and
  changing their attributes.

  Thanks to Debarshi Ray, we do have a pull request to use this to fix a
  problem with gnome-online-accounts - as mentioned last time:

     https://gitlab.gnome.org/GNOME/gnome-online-accounts/merge_requests/47

  Without this, g-o-a has to constantly poll a keyring-based kerberos
  cache to find out if kinit has changed anything.

  [ There are other notification pending: mount/sb fsinfo notifications
    for libmount that Karel Zak and Ian Kent have been working on, and
    Christian Brauner would like to use them in lxc, but let's see how
    this one works first ]

  LSM hooks are included:

   - A set of hooks are provided that allow an LSM to rule on whether or
     not a watch may be set. Each of these hooks takes a different
     "watched object" parameter, so they're not really shareable. The
     LSM should use current's credentials. [Wanted by SELinux & Smack]

   - A hook is provided to allow an LSM to rule on whether or not a
     particular message may be posted to a particular queue. This is
     given the credentials from the event generator (which may be the
     system) and the watch setter. [Wanted by Smack]

  I've provided SELinux and Smack with implementations of some of these
  hooks.

  WHY
  ===

  Key/keyring notifications are desirable because if you have your
  kerberos tickets in a file/directory, your Gnome desktop will monitor
  that using something like fanotify and tell you if your credentials
  cache changes.

  However, we also have the ability to cache your kerberos tickets in
  the session, user or persistent keyring so that it isn't left around
  on disk across a reboot or logout. Keyrings, however, cannot currently
  be monitored asynchronously, so the desktop has to poll for it - not
  so good on a laptop. This facility will allow the desktop to avoid the
  need to poll.

  DESIGN DECISIONS
  ================

   - The notification queue is built on top of a standard pipe. Messages
     are effectively spliced in. The pipe is opened with a special flag:

        pipe2(fds, O_NOTIFICATION_PIPE);

     The special flag has the same value as O_EXCL (which doesn't seem
     like it will ever be applicable in this context)[?]. It is given up
     front to make it a lot easier to prohibit splice&co from accessing
     the pipe.

     [?] Should this be done some other way?  I'd rather not use up a new
         O_* flag if I can avoid it - should I add a pipe3() system call
         instead?

     The pipe is then configured::

        ioctl(fds[1], IOC_WATCH_QUEUE_SET_SIZE, queue_depth);
        ioctl(fds[1], IOC_WATCH_QUEUE_SET_FILTER, &filter);

     Messages are then read out of the pipe using read().

   - It should be possible to allow write() to insert data into the
     notification pipes too, but this is currently disabled as the
     kernel has to be able to insert messages into the pipe *without*
     holding pipe->mutex and the code to make this work needs careful
     auditing.

   - sendfile(), splice() and vmsplice() are disabled on notification
     pipes because of the pipe->mutex issue and also because they
     sometimes want to revert what they just did - but one or more
     notification messages might've been interleaved in the ring.

   - The kernel inserts messages with the wait queue spinlock held. This
     means that pipe_read() and pipe_write() have to take the spinlock
     to update the queue pointers.

   - Records in the buffer are binary, typed and have a length so that
     they can be of varying size.

     This allows multiple heterogeneous sources to share a common
     buffer; there are 16 million types available, of which I've used
     just a few, so there is scope for others to be used. Tags may be
     specified when a watchpoint is created to help distinguish the
     sources.

   - Records are filterable as types have up to 256 subtypes that can be
     individually filtered. Other filtration is also available.

   - Notification pipes don't interfere with each other; each may be
     bound to a different set of watches. Any particular notification
     will be copied to all the queues that are currently watching for it
     - and only those that are watching for it.

   - When recording a notification, the kernel will not sleep, but will
     rather mark a queue as having lost a message if there's
     insufficient space. read() will fabricate a loss notification
     message at an appropriate point later.

   - The notification pipe is created and then watchpoints are attached
     to it, using one of:

        keyctl_watch_key(KEY_SPEC_SESSION_KEYRING, fds[1], 0x01);
        watch_mount(AT_FDCWD, "/", 0, fd, 0x02);
        watch_sb(AT_FDCWD, "/mnt", 0, fd, 0x03);

     where in both cases, fd indicates the queue and the number after is
     a tag between 0 and 255.

   - Watches are removed if either the notification pipe is destroyed or
     the watched object is destroyed. In the latter case, a message will
     be generated indicating the enforced watch removal.

  Things I want to avoid:

   - Introducing features that make the core VFS dependent on the
     network stack or networking namespaces (ie. usage of netlink).

   - Dumping all this stuff into dmesg and having a daemon that sits
     there parsing the output and distributing it as this then puts the
     responsibility for security into userspace and makes handling
     namespaces tricky. Further, dmesg might not exist or might be
     inaccessible inside a container.

   - Letting users see events they shouldn't be able to see.

  TESTING AND MANPAGES
  ====================

   - The keyutils tree has a pipe-watch branch that has keyctl commands
     for making use of notifications. Proposed manual pages can also be
     found on this branch, though a couple of them really need to go to
     the main manpages repository instead.

     If the kernel supports the watching of keys, then running "make
     test" on that branch will cause the testing infrastructure to spawn
     a monitoring process on the side that monitors a notifications pipe
     for all the key/keyring changes induced by the tests and they'll
     all be checked off to make sure they happened.

        https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/keyutils.git/log/?h=pipe-watch

   - A test program is provided (samples/watch_queue/watch_test) that
     can be used to monitor for keyrings, mount and superblock events.
     Information on the notifications is simply logged to stdout"

* tag 'notifications-20200601' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
  smack: Implement the watch_key and post_notification hooks
  selinux: Implement the watch_key security hook
  keys: Make the KEY_NEED_* perms an enum rather than a mask
  pipe: Add notification lossage handling
  pipe: Allow buffers to be marked read-whole-or-error for notifications
  Add sample notification program
  watch_queue: Add a key/keyring notification facility
  security: Add hooks to rule on setting a watch
  pipe: Add general notification queue support
  pipe: Add O_NOTIFICATION_PIPE
  security: Add a hook for the point of notification insertion
  uapi: General notification queue definitions

EFI on ARM only supports short descriptors, and given that it mandates
that the MMU and caches are on, it is implied that booting in HYP mode
is not supported.

However, implementations of EFI exist (i.e., U-Boot) that ignore this
requirement, which is not entirely unreasonable, given that it makes
HYP mode inaccessible to the operating system.

So let's make sure that we can deal with this condition gracefully.
We already tolerate booting the EFI stub with the caches off (even
though this violates the EFI spec as well), and so we should deal
with HYP mode boot with MMU and caches either on or off.

- When the MMU and caches are on, we can ignore the HYP stub altogether,
  since we can carry on executing at HYP. We do need to ensure that we
  disable the MMU at HYP before entering the kernel proper.

- When the MMU and caches are off, we have to drop to SVC mode so that
  we can set up the page tables using short descriptors. In this case,
  we need to install the HYP stub as usual, so that we can return to HYP
  mode before handing over to the kernel proper.
Tested-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

ZBOOT_ROM_TEXT and ZBOOT_ROM_BSS are defined as 'hex' but had a default
of "0". Kconfig will helpfully expand a text entry of 0 to 0x0 but
because this is not the same as the default value it was treated as
being explicitly set when running 'make savedefconfig' so most arm
defconfigs have CONFIG_ZBOOT_ROM_TEXT=0x0 and CONFIG_ZBOOT_ROM_BSS=0x0.

Change the default to 0x0 which will mean next time the defconfigs are
re-generated the spurious config entries will be removed.
Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

The patch introducing the struct was probably never compile tested,
because it sets a handler with a wrong function signature. Wrap the
handler into a functions with the correct signature to fix the build.

Fixes: 0f1c9688 ("tty/sysrq: alpha: export and use __sysrq_get_key_op()")
Cc: Emil Velikov <emil.l.velikov@gmail.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Matt Turner <mattst88@gmail.com>

Signed-off-by: Matt Turner <mattst88@gmail.com>

Replace sg++ with sg = sg_next(sg).
Signed-off-by: Xu Wang <vulab@iscas.ac.cn>
Signed-off-by: Matt Turner <mattst88@gmail.com>

The commits cd0e00c1 and 92d7223a broke boot on the Alpha Avanti
platform. The patches move memory barriers after a write before the write.
The result is that if there's iowrite followed by ioread, there is no
barrier between them.

The Alpha architecture allows reordering of the accesses to the I/O space,
and the missing barrier between write and read causes hang with serial
port and real time clock.

This patch makes barriers confiorm to the specification.

1. We add mb() before readX_relaxed and writeX_relaxed -
   memory-barriers.txt claims that these functions must be ordered w.r.t.
   each other. Alpha doesn't order them, so we need an explicit barrier.
2. We add mb() before reads from the I/O space - so that if there's a
   write followed by a read, there should be a barrier between them.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Fixes: cd0e00c1 ("alpha: io: reorder barriers to guarantee writeX() and iowriteX() ordering")
Fixes: 92d7223a ("alpha: io: reorder barriers to guarantee writeX() and iowriteX() ordering #2")
Cc: stable@vger.kernel.org      # v4.17+
Acked-by: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Reviewed-by: Maciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: Matt Turner <mattst88@gmail.com>