If seq_file .next function does not change position index,
read after some lseek can generate unexpected output:

    $ dd if=/proc/keys bs=1  # full usual output
    0f6bfdf5 I--Q---     2 perm 3f010000  1000  1000 user      4af2f79ab8848d0a: 740
    1fb91b32 I--Q---     3 perm 1f3f0000  1000 65534 keyring   _uid.1000: 2
    27589480 I--Q---     1 perm 0b0b0000     0     0 user      invocation_id: 16
    2f33ab67 I--Q---   152 perm 3f030000     0     0 keyring   _ses: 2
    33f1d8fa I--Q---     4 perm 3f030000  1000  1000 keyring   _ses: 1
    3d427fda I--Q---     2 perm 3f010000  1000  1000 user      69ec44aec7678e5a: 740
    3ead4096 I--Q---     1 perm 1f3f0000  1000 65534 keyring   _uid_ses.1000: 1
    521+0 records in
    521+0 records out
    521 bytes copied, 0,00123769 s, 421 kB/s

But a read after lseek in middle of last line results in the partial
last line and then a repeat of the final line:

    $ dd if=/proc/keys bs=500 skip=1
    dd: /proc/keys: cannot skip to specified offset
    g   _uid_ses.1000: 1
    3ead4096 I--Q---     1 perm 1f3f0000  1000 65534 keyring   _uid_ses.1000: 1
    0+1 records in
    0+1 records out
    97 bytes copied, 0,000135035 s, 718 kB/s

and a read after lseek beyond end of file results in the last line being
shown:

    $ dd if=/proc/keys bs=1000 skip=1   # read after lseek beyond end of file
    dd: /proc/keys: cannot skip to specified offset
    3ead4096 I--Q---     1 perm 1f3f0000  1000 65534 keyring   _uid_ses.1000: 1
    0+1 records in
    0+1 records out
    76 bytes copied, 0,000119981 s, 633 kB/s

See https://bugzilla.kernel.org/show_bug.cgi?id=206283

Fixes: 1f4aace6 ("fs/seq_file.c: simplify seq_file iteration code ...")
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull EFI fixes from Ingo Molnar:
 "Misc EFI fixes, including the boot failure regression caused by the
  BSS section not being cleared by the loaders"

* tag 'efi-urgent-2020-04-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  efi/x86: Revert struct layout change to fix kexec boot regression
  efi/x86: Don't remap text<->rodata gap read-only for mixed mode
  efi/x86: Fix the deletion of variables in mixed mode
  efi/libstub/file: Merge file name buffers to reduce stack usage
  Documentation/x86, efi/x86: Clarify EFI handover protocol and its requirements
  efi/arm: Deal with ADR going out of range in efi_enter_kernel()
  efi/x86: Always relocate the kernel for EFI handover entry
  efi/x86: Move efi stub globals from .bss to .data
  efi/libstub/x86: Remove redundant assignment to pointer hdr
  efi/cper: Use scnprintf() for avoiding potential buffer overflow

Pull hyperv fixes from Wei Liu:

 - a series from Tianyu Lan to fix crash reporting on Hyper-V

 - three miscellaneous cleanup patches

* tag 'hyperv-fixes-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  x86/Hyper-V: Report crash data in die() when panic_on_oops is set
  x86/Hyper-V: Report crash register data when sysctl_record_panic_msg is not set
  x86/Hyper-V: Report crash register data or kmsg before running crash kernel
  x86/Hyper-V: Trigger crash enlightenment only once during system crash.
  x86/Hyper-V: Free hv_panic_page when fail to register kmsg dump
  x86/Hyper-V: Unload vmbus channel in hv panic callback
  x86: hyperv: report value of misc_features
  hv_debugfs: Make hv_debug_root static
  hv: hyperv_vmbus.h: Replace zero-length array with flexible-array member

Pull btrfs fixes from David Sterba:
 "We have a few regressions and one fix for stable:

   - revert fsync optimization

   - fix lost i_size update

   - fix a space accounting leak

   - build fix, add back definition of a deprecated ioctl flag

   - fix search condition for old roots in relocation"

* tag 'for-5.7-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: re-instantiate the removed BTRFS_SUBVOL_CREATE_ASYNC definition
  btrfs: fix reclaim counter leak of space_info objects
  btrfs: make full fsyncs always operate on the entire file again
  btrfs: fix lost i_size update after cloning inline extent
  btrfs: check commit root generation in should_ignore_root

Pull AFS fixes from David Howells:

 - Fix the decoding of fetched file status records so that the xdr
   pointer is advanced under all circumstances.

 - Fix the decoding of a fetched file status record that indicates an
   inline abort (ie. an error) so that it sets the flag saying the
   decoder stored the abort code.

 - Fix the decoding of the result of the rename operation so that it
   doesn't skip the decoding of the second fetched file status (ie. that
   of the dest dir) in the case that the source and dest dirs were the
   same as this causes the xdr pointer not to be advanced, leading to
   incorrect decoding of subsequent parts of the reply.

 - Fix the dump of a bad YFSFetchStatus record to dump the full length.

 - Fix a race between local editing of directory contents and accessing
   the dir for reading or d_revalidate by using the same lock in both.

 - Fix afs_d_revalidate() to not accidentally reverse the version on a
   dentry when it's meant to be bringing it forward.

* tag 'afs-fixes-20200413' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
  afs: Fix afs_d_validate() to set the right directory version
  afs: Fix race between post-modification dir edit and readdir/d_revalidate
  afs: Fix length of dump of bad YFSFetchStatus record
  afs: Fix rename operation status delivery
  afs: Fix decoding of inline abort codes from version 1 status records
  afs: Fix missing XDR advance in xdr_decode_{AFS,YFS}FSFetchStatus()

Commit

  0a67361d ("efi/x86: Remove runtime table address from kexec EFI setup data")

removed the code that retrieves the non-remapped UEFI runtime services
pointer from the data structure provided by kexec, as it was never really
needed on the kexec boot path: mapping the runtime services table at its
non-remapped address is only needed when calling SetVirtualAddressMap(),
which never happens during a kexec boot in the first place.

However, dropping the 'runtime' member from struct efi_setup_data was a
mistake. That struct is shared ABI between the kernel and the kexec tooling
for x86, and so we cannot simply change its layout. So let's put back the
removed field, but call it 'unused' to reflect the fact that we never look
at its contents. While at it, add a comment to remind our future selves
that the layout is external ABI.

Fixes: 0a67361d ("efi/x86: Remove runtime table address from kexec EFI setup data")
Reported-by: Theodore Ts'o <tytso@mit.edu>
Tested-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Commit

  d9e3d2c4 ("efi/x86: Don't map the entire kernel text RW for mixed mode")

updated the code that creates the 1:1 memory mapping to use read-only
attributes for the 1:1 alias of the kernel's text and rodata sections, to
protect it from inadvertent modification. However, it failed to take into
account that the unused gap between text and rodata is given to the page
allocator for general use.

If the vmap'ed stack happens to be allocated from this region, any by-ref
output arguments passed to EFI runtime services that are allocated on the
stack (such as the 'datasize' argument taken by GetVariable() when invoked
from efivar_entry_size()) will be referenced via a read-only mapping,
resulting in a page fault if the EFI code tries to write to it:

  BUG: unable to handle page fault for address: 00000000386aae88
  #PF: supervisor write access in kernel mode
  #PF: error_code(0x0003) - permissions violation
  PGD fd61063 P4D fd61063 PUD fd62063 PMD 386000e1
  Oops: 0003 [#1] SMP PTI
  CPU: 2 PID: 255 Comm: systemd-sysv-ge Not tainted 5.6.0-rc4-default+ #22
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
  RIP: 0008:0x3eaeed95
  Code: ...  <89> 03 be 05 00 00 80 a1 74 63 b1 3e 83 c0 48 e8 44 d2 ff ff eb 05
  RSP: 0018:000000000fd73fa0 EFLAGS: 00010002
  RAX: 0000000000000001 RBX: 00000000386aae88 RCX: 000000003e9f1120
  RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000001
  RBP: 000000000fd73fd8 R08: 00000000386aae88 R09: 0000000000000000
  R10: 0000000000000002 R11: 0000000000000000 R12: 0000000000000000
  R13: ffffc0f040220000 R14: 0000000000000000 R15: 0000000000000000
  FS:  00007f21160ac940(0000) GS:ffff9cf23d500000(0000) knlGS:0000000000000000
  CS:  0008 DS: 0018 ES: 0018 CR0: 0000000080050033
  CR2: 00000000386aae88 CR3: 000000000fd6c004 CR4: 00000000003606e0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  Call Trace:
  Modules linked in:
  CR2: 00000000386aae88
  ---[ end trace a8bfbd202e712834 ]---

Let's fix this by remapping text and rodata individually, and leave the
gaps mapped read-write.

Fixes: d9e3d2c4 ("efi/x86: Don't map the entire kernel text RW for mixed mode")
Reported-by: Jiri Slaby <jslaby@suse.cz>
Tested-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200409130434.6736-10-ardb@kernel.org

efi_thunk_set_variable() treated the NULL "data" pointer as an invalid
parameter, and this broke the deletion of variables in mixed mode.
This commit fixes the check of data so that the userspace program can
delete a variable in mixed mode.

Fixes: 8319e9d5 ("efi/x86: Handle by-ref arguments covering multiple pages in mixed mode")
Signed-off-by: Gary Lin <glin@suse.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200408081606.1504-1-glin@suse.com
Link: https://lore.kernel.org/r/20200409130434.6736-9-ardb@kernel.org

Arnd reports that commit

  9302c1bb ("efi/libstub: Rewrite file I/O routine")

reworks the file I/O routines in a way that triggers the following
warning:

  drivers/firmware/efi/libstub/file.c:240:1: warning: the frame size
            of 1200 bytes is larger than 1024 bytes [-Wframe-larger-than=]

We can work around this issue dropping an instance of efi_char16_t[256]
from the stack frame, and reusing the 'filename' field of the file info
struct that we use to obtain file information from EFI (which contains
the file name even though we already know it since we used it to open
the file in the first place)
Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200409130434.6736-8-ardb@kernel.org

The EFI handover protocol was introduced on x86 to permit the boot
loader to pass a populated boot_params structure as an additional
function argument to the entry point. This allows the bootloader to
pass the base and size of a initrd image, which is more flexible
than relying on the EFI stub's file I/O routines, which can only
access the file system from which the kernel image itself was loaded
from firmware.

This approach requires a fair amount of internal knowledge regarding
the layout of the boot_params structure on the part of the boot loader,
as well as knowledge regarding the allowed placement of the initrd in
memory, and so it has been deprecated in favour of a new initrd loading
method that is based on existing UEFI protocols and best practices.

So update the x86 boot protocol documentation to clarify that the EFI
handover protocol has been deprecated, and while at it, add a note that
invoking the EFI handover protocol still requires the PE/COFF image to
be loaded properly (as opposed to simply being copied into memory).
Also, drop the code32_start header field from the list of values that
need to be provided, as this is no longer required.
Reviewed-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200409130434.6736-7-ardb@kernel.org

Commit

  0698fac4 ("efi/arm: Clean EFI stub exit code from cache instead of avoiding it")

introduced a PC-relative reference to 'call_cache_fn' into
efi_enter_kernel(), which lives way at the end of head.S. In some cases,
the ARM version of the ADR instruction does not have sufficient range,
resulting in a build error:

  arch/arm/boot/compressed/head.S:1453: Error: invalid constant (fffffffffffffbe4) after fixup

ARM defines an alternative with a wider range, called ADRL, but this does
not exist for Thumb-2. At the same time, the ADR instruction in Thumb-2
has a wider range, and so it does not suffer from the same issue.

So let's switch to ADRL for ARM builds, and keep the ADR for Thumb-2 builds.
Reported-by: Arnd Bergmann <arnd@arndb.de>
Tested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200409130434.6736-6-ardb@kernel.org

Commit

  d5cdf4cf ("efi/x86: Don't relocate the kernel unless necessary")

tries to avoid relocating the kernel in the EFI stub as far as possible.

However, when systemd-boot is used to boot a unified kernel image [1],
the image is constructed by embedding the bzImage as a .linux section in
a PE executable that contains a small stub loader from systemd that will
call the EFI stub handover entry, together with additional sections and
potentially an initrd. When this image is constructed, by for example
dracut, the initrd is placed after the bzImage without ensuring that at
least init_size bytes are available for the bzImage. If the kernel is
not relocated by the EFI stub, this could result in the compressed
kernel's startup code in head_{32,64}.S overwriting the initrd.

To prevent this, unconditionally relocate the kernel if the EFI stub was
entered via the handover entry point.

[1] https://systemd.io/BOOT_LOADER_SPECIFICATION/#type-2-efi-unified-kernel-images

Fixes: d5cdf4cf ("efi/x86: Don't relocate the kernel unless necessary")
Reported-by: Sergey Shatunov <me@prok.pw>
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200406180614.429454-2-nivedita@alum.mit.edu
Link: https://lore.kernel.org/r/20200409130434.6736-5-ardb@kernel.org

Commit

  3ee372cc ("x86/boot/compressed/64: Remove .bss/.pgtable from bzImage")

removed the .bss section from the bzImage.

However, while a PE loader is required to zero-initialize the .bss
section before calling the PE entry point, the EFI handover protocol
does not currently document any requirement that .bss be initialized by
the bootloader prior to calling the handover entry.

When systemd-boot is used to boot a unified kernel image [1], the image
is constructed by embedding the bzImage as a .linux section in a PE
executable that contains a small stub loader from systemd together with
additional sections and potentially an initrd. As the .bss section
within the bzImage is no longer explicitly present as part of the file,
it is not initialized before calling the EFI handover entry.
Furthermore, as the size of the embedded .linux section is only the size
of the bzImage file itself, the .bss section's memory may not even have
been allocated.

In particular, this can result in efi_disable_pci_dma being true even
when it was not specified via the command line or configuration option,
which in turn causes crashes while booting on some systems.

To avoid issues, place all EFI stub global variables into the .data
section instead of .bss. As of this writing, only boolean flags for a
few command line arguments and the sys_table pointer were in .bss and
will now move into the .data section.

[1] https://systemd.io/BOOT_LOADER_SPECIFICATION/#type-2-efi-unified-kernel-images

Fixes: 3ee372cc ("x86/boot/compressed/64: Remove .bss/.pgtable from bzImage")
Reported-by: Sergey Shatunov <me@prok.pw>
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200406180614.429454-1-nivedita@alum.mit.edu
Link: https://lore.kernel.org/r/20200409130434.6736-4-ardb@kernel.org

The pointer hdr is being assigned a value that is never read and
it is being updated later with a new value. The assignment is
redundant and can be removed.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200402102537.503103-1-colin.king@canonical.com
Link: https://lore.kernel.org/r/20200409130434.6736-3-ardb@kernel.org

Since snprintf() returns the would-be-output size instead of the
actual output size, the succeeding calls may go beyond the given
buffer limit.  Fix it by replacing with scnprintf().
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200311072145.5001-1-tiwai@suse.de
Link: https://lore.kernel.org/r/20200409130434.6736-2-ardb@kernel.org

The cleanup in commit 630f289b ("asm-generic: make more
kernel-space headers mandatory") did not take into account the recently
added line for hardirq.h in commit acc45648 ("m68k: Switch to
asm-generic/hardirq.h"), leading to the following message during the
build:

    scripts/Makefile.asm-generic:25: redundant generic-y found in arch/m68k/include/asm/Kbuild: hardirq.h

Fix this by dropping the now redundant line.

Fixes: 630f289b ("asm-generic: make more kernel-space headers mandatory")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

If a dentry's version is somewhere between invalid_before and the current
directory version, we should be setting it forward to the current version,
not backwards to the invalid_before version.  Note that we're only doing
this at all because dentry::d_fsdata isn't large enough on a 32-bit system.

Fix this by using a separate variable for invalid_before so that we don't
accidentally clobber the current dir version.

Fixes: a4ff7401 ("afs: Keep track of invalid-before version for dentry coherency")
Signed-off-by: David Howells <dhowells@redhat.com>

AFS directories are retained locally as a structured file, with lookup
being effected by a local search of the file contents.  When a modification
(such as mkdir) happens, the dir file content is modified locally rather
than redownloading the directory.

The directory contents are accessed in a number of ways, with a number of
different locks schemes:

 (1) Download of contents - dvnode->validate_lock/write in afs_read_dir().

 (2) Lookup and readdir - dvnode->validate_lock/read in afs_dir_iterate(),
     downgrading from (1) if necessary.

 (3) d_revalidate of child dentry - dvnode->validate_lock/read in
     afs_do_lookup_one() downgrading from (1) if necessary.

 (4) Edit of dir after modification - page locks on individual dir pages.

Unfortunately, because (4) uses different locking scheme to (1) - (3),
nothing protects against the page being scanned whilst the edit is
underway.  Even download is not safe as it doesn't lock the pages - relying
instead on the validate_lock to serialise as a whole (the theory being that
directory contents are treated as a block and always downloaded as a
block).

Fix this by write-locking dvnode->validate_lock around the edits.  Care
must be taken in the rename case as there may be two different dirs - but
they need not be locked at the same time.  In any case, once the lock is
taken, the directory version must be rechecked, and the edit skipped if a
later version has been downloaded by revalidation (there can't have been
any local changes because the VFS holds the inode lock, but there can have
been remote changes).

Fixes: 63a4681f ("afs: Locally edit directory data for mkdir/create/unlink/...")
Signed-off-by: David Howells <dhowells@redhat.com>

Fix the length of the dump of a bad YFSFetchStatus record.  The function
was copied from the AFS version, but the YFS variant contains bigger fields
and extra information, so expand the dump to match.
Signed-off-by: David Howells <dhowells@redhat.com>

The afs_deliver_fs_rename() and yfs_deliver_fs_rename() functions both only
decode the second file status returned unless the parent directories are
different - unfortunately, this means that the xdr pointer isn't advanced
and the volsync record will be read incorrectly in such an instance.

Fix this by always decoding the second status into the second
status/callback block which wasn't being used if the dirs were the same.

The afs_update_dentry_version() calls that update the directory data
version numbers on the dentries can then unconditionally use the second
status record as this will always reflect the state of the destination dir
(the two records will be identical if the destination dir is the same as
the source dir)

Fixes: 260a9803 ("[AFS]: Add "directory write" support.")
Fixes: 30062bd1 ("afs: Implement YFS support in the fs client")
Signed-off-by: David Howells <dhowells@redhat.com>

If we're decoding an AFSFetchStatus record and we see that the version is 1
and the abort code is set and we're expecting inline errors, then we store
the abort code and ignore the remaining status record (which is correct),
but we don't set the flag to say we got a valid abort code.

This can affect operation of YFS.RemoveFile2 when removing a file and the
operation of {,Y}FS.InlineBulkStatus when prospectively constructing or
updating of a set of inodes during a lookup.

Fix this to indicate the reception of a valid abort code.

Fixes: a38a7558 ("afs: Fix unlink to handle YFS.RemoveFile2 better")
Signed-off-by: David Howells <dhowells@redhat.com>

If we receive a status record that has VNOVNODE set in the abort field,
xdr_decode_AFSFetchStatus() and xdr_decode_YFSFetchStatus() don't advance
the XDR pointer, thereby corrupting anything subsequent decodes from the
same block of data.

This has the potential to affect AFS.InlineBulkStatus and
YFS.InlineBulkStatus operation, but probably doesn't since the status
records are extracted as individual blocks of data and the buffer pointer
is reset between blocks.

It does affect YFS.RemoveFile2 operation, corrupting the volsync record -
though that is not currently used.

Other operations abort the entire operation rather than returning an error
inline, in which case there is no decoding to be done.

Fix this by unconditionally advancing the xdr pointer.

Fixes: 684b0f68 ("afs: Fix AFSFetchStatus decoder to provide OpenAFS compatibility")
Signed-off-by: David Howells <dhowells@redhat.com>

This sorts the actual field names too, potentially causing even more
chaos and confusion at merge time if you have edited the MAINTAINERS
file.  But the end result is a more consistent layout, and hopefully
it's a one-time pain minimized by doing this just before the -rc1
release.

This was entirely scripted:

  ./scripts/parse-maintainers.pl --input=MAINTAINERS --output=MAINTAINERS --order
Requested-by: Joe Perches <joe@perches.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

They are all supposed to be sorted, but people who add new entries don't
always know the alphabet.  Plus sometimes the entry names get edited,
and people don't then re-order the entry.

Let's see how painful this will be for merging purposes (the MAINTAINERS
file is often edited in various different trees), but Joe claims there's
relatively few patches in -next that touch this, and doing it just
before -rc1 is likely the best time.  Fingers crossed.

This was scripted with

  /scripts/parse-maintainers.pl --input=MAINTAINERS --output=MAINTAINERS

but then I also ended up manually upper-casing a few entry names that
stood out when looking at the end result.
Requested-by: Joe Perches <joe@perches.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull x86 fixes from Thomas Gleixner:
 "A set of three patches to fix the fallout of the newly added split
  lock detection feature.

  It addressed the case where a KVM guest triggers a split lock #AC and
  KVM reinjects it into the guest which is not prepared to handle it.

  Add proper sanity checks which prevent the unconditional injection
  into the guest and handles the #AC on the host side in the same way as
  user space detections are handled. Depending on the detection mode it
  either warns and disables detection for the task or kills the task if
  the mode is set to fatal"

* tag 'x86-urgent-2020-04-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  KVM: VMX: Extend VMXs #AC interceptor to handle split lock #AC in guest
  KVM: x86: Emulate split-lock access as a write in emulator
  x86/split_lock: Provide handle_guest_split_lock()

Pull time(keeping) updates from Thomas Gleixner:

 - Fix the time_for_children symlink in /proc/$PID/ so it properly
   reflects that it part of the 'time' namespace

 - Add the missing userns limit for the allowed number of time
   namespaces, which was half defined but the actual array member was
   not added. This went unnoticed as the array has an exessive empty
   member at the end but introduced a user visible regression as the
   output was corrupted.

 - Prevent further silent ucount corruption by adding a BUILD_BUG_ON()
   to catch half updated data.

* tag 'timers-urgent-2020-04-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  ucount: Make sure ucounts in /proc/sys/user don't regress again
  time/namespace: Add max_time_namespaces ucount
  time/namespace: Fix time_for_children symlink

Pull scheduler fixes/updates from Thomas Gleixner:

 - Deduplicate the average computations in the scheduler core and the
   fair class code.

 - Fix a raise between runtime distribution and assignement which can
   cause exceeding the quota by up to 70%.

 - Prevent negative results in the imbalanace calculation

 - Remove a stale warning in the workqueue code which can be triggered
   since the call site was moved out of preempt disabled code. It's a
   false positive.

 - Deduplicate the print macros for procfs

 - Add the ucmap values to the SCHED_DEBUG procfs output for completness

* tag 'sched-urgent-2020-04-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/debug: Add task uclamp values to SCHED_DEBUG procfs
  sched/debug: Factor out printing formats into common macros
  sched/debug: Remove redundant macro define
  sched/core: Remove unused rq::last_load_update_tick
  workqueue: Remove the warning in wq_worker_sleeping()
  sched/fair: Fix negative imbalance in imbalance calculation
  sched/fair: Fix race between runtime distribution and assignment
  sched/fair: Align rq->avg_idle and rq->avg_scan_cost

Pull perf fixes from Thomas Gleixner:
 "Three fixes/updates for perf:

   - Fix the perf event cgroup tracking which tries to track the cgroup
     even for disabled events.

   - Add Ice Lake server support for uncore events

   - Disable pagefaults when retrieving the physical address in the
     sampling code"

* tag 'perf-urgent-2020-04-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/core: Disable page faults when getting phys address
  perf/x86/intel/uncore: Add Ice Lake server uncore support
  perf/cgroup: Correct indirection in perf_less_group_idx()
  perf/core: Fix event cgroup tracking

Pull locking fixes from Thomas Gleixner:
 "Three small fixes/updates for the locking core code:

   - Plug a task struct reference leak in the percpu rswem
     implementation.

   - Document the refcount interaction with PID_MAX_LIMIT

   - Improve the 'invalid wait context' data dump in lockdep so it
     contains all information which is required to decode the problem"

* tag 'locking-urgent-2020-04-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/lockdep: Improve 'invalid wait context' splat
  locking/refcount: Document interaction with PID_MAX_LIMIT
  locking/percpu-rwsem: Fix a task_struct refcount

Pull cifs fixes from Steve French:
 "Ten cifs/smb fixes:

   - five RDMA (smbdirect) related fixes

   - add experimental support for swap over SMB3 mounts

   - also a fix which improves performance of signed connections"

* tag '5.7-rc-smb3-fixes-part2' of git://git.samba.org/sfrench/cifs-2.6:
  smb3: enable swap on SMB3 mounts
  smb3: change noisy error message to FYI
  smb3: smbdirect support can be configured by default
  cifs: smbd: Do not schedule work to send immediate packet on every receive
  cifs: smbd: Properly process errors on ib_post_send
  cifs: Allocate crypto structures on the fly for calculating signatures of incoming packets
  cifs: smbd: Update receive credits before sending and deal with credits roll back on failure before sending
  cifs: smbd: Check send queue size before posting a send
  cifs: smbd: Merge code to track pending packets
  cifs: ignore cached share root handle closing errors

Pull NFS client bugfix from Trond Myklebust:
 "Fix an RCU read lock leakage in pnfs_alloc_ds_commits_list()"

* tag 'nfs-for-5.7-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  pNFS: Fix RCU lock leakage

Pull nios2 updates from Ley Foon Tan:

 - Remove nios2-dev@lists.rocketboards.org from MAINTAINERS

 - remove 'resetvalue' property

 - rename 'altr,gpio-bank-width' -> 'altr,ngpio'

 - enable the common clk subsystem on Nios2

* tag 'nios2-v5.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/lftan/nios2:
  MAINTAINERS: Remove nios2-dev@lists.rocketboards.org
  arch: nios2: remove 'resetvalue' property
  arch: nios2: rename 'altr,gpio-bank-width' -> 'altr,ngpio'
  arch: nios2: Enable the common clk subsystem on Nios2

Pull dma-mapping fixes from Christoph Hellwig:

 - fix an integer truncation in dma_direct_get_required_mask
   (Kishon Vijay Abraham)

 - fix the display of dma mapping types (Grygorii Strashko)

* tag 'dma-mapping-5.7-1' of git://git.infradead.org/users/hch/dma-mapping:
  dma-debug: fix displaying of dma allocation type
  dma-direct: fix data truncation in dma_direct_get_required_mask()

Pull more Kbuild updates from Masahiro Yamada:

 - raise minimum supported binutils version to 2.23

 - remove old CONFIG_AS_* macros that we know binutils >= 2.23 supports

 - move remaining CONFIG_AS_* tests to Kconfig from Makefile

 - enable -Wtautological-compare warnings to catch more issues

 - do not support GCC plugins for GCC <= 4.7

 - fix various breakages of 'make xconfig'

 - include the linker version used for linking the kernel into
   LINUX_COMPILER, which is used for the banner, and also exposed to
   /proc/version

 - link lib-y objects to vmlinux forcibly when CONFIG_MODULES=y, which
   allows us to remove the lib-ksyms.o workaround, and to solve the last
   known issue of the LLVM linker

 - add dummy tools in scripts/dummy-tools/ to enable all compiler tests
   in Kconfig, which will be useful for distro maintainers

 - support the single switch, LLVM=1 to use Clang and all LLVM utilities
   instead of GCC and Binutils.

 - support LLVM_IAS=1 to enable the integrated assembler, which is still
   experimental

* tag 'kbuild-v5.7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (36 commits)
  kbuild: fix comment about missing include guard detection
  kbuild: support LLVM=1 to switch the default tools to Clang/LLVM
  kbuild: replace AS=clang with LLVM_IAS=1
  kbuild: add dummy toolchains to enable all cc-option etc. in Kconfig
  kbuild: link lib-y objects to vmlinux forcibly when CONFIG_MODULES=y
  MIPS: fw: arc: add __weak to prom_meminit and prom_free_prom_memory
  kbuild: remove -I$(srctree)/tools/include from scripts/Makefile
  kbuild: do not pass $(KBUILD_CFLAGS) to scripts/mkcompile_h
  Documentation/llvm: fix the name of llvm-size
  kbuild: mkcompile_h: Include $LD version in /proc/version
  kconfig: qconf: Fix a few alignment issues
  kconfig: qconf: remove some old bogus TODOs
  kconfig: qconf: fix support for the split view mode
  kconfig: qconf: fix the content of the main widget
  kconfig: qconf: Change title for the item window
  kconfig: qconf: clean deprecated warnings
  gcc-plugins: drop support for GCC <= 4.7
  kbuild: Enable -Wtautological-compare
  x86: update AS_* macros to binutils >=2.23, supporting ADX and AVX2
  crypto: x86 - clean up poly1305-x86_64-cryptogams.S by 'make clean'
  ...

I do not longer work for credativ Germany.

Please, use my private email address instead.

This is for the case when people want to CC me on
patches sent from my old business email address.
Signed-off-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

When oops happens with panic_on_oops unset, the oops
thread is killed by die() and system continues to run.
In such case, guest should not report crash register
data to host since system still runs. Check panic_on_oops
and return directly in hyperv_report_panic() when the function
is called in the die() and panic_on_oops is unset. Fix it.

Fixes: 7ed4325a ("Drivers: hv: vmbus: Make panic reporting to be more useful")
Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20200406155331.2105-7-Tianyu.Lan@microsoft.comSigned-off-by: Wei Liu <wei.liu@kernel.org>

When sysctl_record_panic_msg is not set, the panic will
not be reported to Hyper-V via hyperv_report_panic_msg().
So the crash should be reported via hyperv_report_panic().

Fixes: 81b18bce ("Drivers: HV: Send one page worth of kmsg dump over Hyper-V during panic")
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
Link: https://lore.kernel.org/r/20200406155331.2105-6-Tianyu.Lan@microsoft.comSigned-off-by: Wei Liu <wei.liu@kernel.org>

We want to notify Hyper-V when a Linux guest VM crash occurs, so
there is a record of the crash even when kdump is enabled.   But
crash_kexec_post_notifiers defaults to "false", so the kdump kernel
runs before the notifiers and Hyper-V never gets notified.  Fix this by
always setting crash_kexec_post_notifiers to be true for Hyper-V VMs.

Fixes: 81b18bce ("Drivers: HV: Send one page worth of kmsg dump over Hyper-V during panic")
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
Link: https://lore.kernel.org/r/20200406155331.2105-5-Tianyu.Lan@microsoft.comSigned-off-by: Wei Liu <wei.liu@kernel.org>

When a guest VM panics, Hyper-V should be notified only once via the
crash synthetic MSRs.  Current Linux code might write these crash MSRs
twice during a system panic:
1) hyperv_panic/die_event() calling hyperv_report_panic()
2) hv_kmsg_dump() calling hyperv_report_panic_msg()

Fix this by not calling hyperv_report_panic() if a kmsg dump has been
successfully registered.  The notification will happen later via
hyperv_report_panic_msg().

Fixes: 7ed4325a ("Drivers: hv: vmbus: Make panic reporting to be more useful")
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
Link: https://lore.kernel.org/r/20200406155331.2105-4-Tianyu.Lan@microsoft.comSigned-off-by: Wei Liu <wei.liu@kernel.org>