Explicitly include DWARF sections when they're present in the build.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20200821194310.3089815-13-keescook@chromium.org

Use the common DISCARDS rule for the linker script in an effort to
regularize the linker script to prepare for warning on orphaned
sections. Additionally clean up left-over no-op macros.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20200821194310.3089815-12-keescook@chromium.org

Avoid .eh_frame* section generation by making sure both CFLAGS and AFLAGS
contain -fno-asychronous-unwind-tables and -fno-unwind-tables.

With all sources of .eh_frame now removed from the build, drop this
DISCARD so we can be alerted in the future if it returns unexpectedly
once orphan section warnings have been enabled.
Suggested-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20200821194310.3089815-11-keescook@chromium.org

Remove last instance of an .eh_frame section by removing the needless Call
Frame Information annotations which were likely leftovers from 32-bit ARM.
Suggested-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20200821194310.3089815-10-keescook@chromium.org

Fix a case of needless quotes in __section(), which Clang doesn't like.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20200821194310.3089815-9-keescook@chromium.org

In preparation for adding --orphan-handling=warn to more architectures,
disable -mbranch-protection, as EFI does not yet support it[1].  This was
noticed due to it producing unwanted .note.gnu.property sections (prefixed
with .init due to the objcopy build step).

However, we must also work around a bug in Clang where the section is
still emitted for code-less object files[2], so also remove the section
during the objcopy.

[1] https://lore.kernel.org/lkml/CAMj1kXHck12juGi=E=P4hWP_8vQhQ+-x3vBMc3TGeRWdQ-XkxQ@mail.gmail.com
[2] https://bugs.llvm.org/show_bug.cgi?id=46480Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20200821194310.3089815-8-keescook@chromium.org

Basically, consider .text.{hot|unlikely|unknown}.* part of .text, too.

When compiling with profiling information (collected via PGO
instrumentations or AutoFDO sampling), Clang will separate code into
.text.hot, .text.unlikely, or .text.unknown sections based on profiling
information. After D79600 (clang-11), these sections will have a
trailing `.` suffix, ie.  .text.hot., .text.unlikely., .text.unknown..

When using -ffunction-sections together with profiling infomation,
either explicitly (FGKASLR) or implicitly (LTO), code may be placed in
sections following the convention:
.text.hot.<foo>, .text.unlikely.<bar>, .text.unknown.<baz>
where <foo>, <bar>, and <baz> are functions.  (This produces one section
per function; we generally try to merge these all back via linker script
so that we don't have 50k sections).

For the above cases, we need to teach our linker scripts that such
sections might exist and that we'd explicitly like them grouped
together, otherwise we can wind up with code outside of the
_stext/_etext boundaries that might not be mapped properly for some
architectures, resulting in boot failures.

If the linker script is not told about possible input sections, then
where the section is placed as output is a heuristic-laiden mess that's
non-portable between linkers (ie. BFD and LLD), and has resulted in many
hard to debug bugs.  Kees Cook is working on cleaning this up by adding
--orphan-handling=warn linker flag used in ARCH=powerpc to additional
architectures. In the case of linker scripts, borrowing from the Zen of
Python: explicit is better than implicit.

Also, ld.bfd's internal linker script considers .text.hot AND
.text.hot.* to be part of .text, as well as .text.unlikely and
.text.unlikely.*. I didn't see support for .text.unknown.*, and didn't
see Clang producing such code in our kernel builds, but I see code in
LLVM that can produce such section names if profiling information is
missing. That may point to a larger issue with generating or collecting
profiles, but I would much rather be safe and explicit than have to
debug yet another issue related to orphan section placement.
Reported-by: Jian Cai <jiancai@google.com>
Suggested-by: Fāng-ruì Sòng <maskray@google.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Luis Lozano <llozano@google.com>
Tested-by: Manoj Gupta <manojgupta@google.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: linux-arch@vger.kernel.org
Cc: stable@vger.kernel.org
Link: https://sourceware.org/git/?p=binutils-gdb.git;a=commitdiff;h=add44f8d5c5c05e08b11e033127a744d61c26aee
Link: https://sourceware.org/git/?p=binutils-gdb.git;a=commitdiff;h=1de778ed23ce7492c523d5850c6c6dbb34152655
Link: https://reviews.llvm.org/D79600
Link: https://bugs.chromium.org/p/chromium/issues/detail?id=1084760
Link: https://lore.kernel.org/r/20200821194310.3089815-7-keescook@chromium.orgDebugged-by: Luis Lozano <llozano@google.com>

When linking vmlinux with LLD, the synthetic sections .symtab, .strtab,
and .shstrtab are listed as orphaned. Add them to the ELF_DETAILS section
so there will be no warnings when --orphan-handling=warn is used more
widely. (They are added above comment as it is the more common
order[1].)

ld.lld: warning: <internal>:(.symtab) is being placed in '.symtab'
ld.lld: warning: <internal>:(.shstrtab) is being placed in '.shstrtab'
ld.lld: warning: <internal>:(.strtab) is being placed in '.strtab'

[1] https://lore.kernel.org/lkml/20200622224928.o2a7jkq33guxfci4@google.com/Reported-by: Fangrui Song <maskray@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: linux-arch@vger.kernel.org
Link: https://lore.kernel.org/r/20200821194310.3089815-6-keescook@chromium.org

The .comment section doesn't belong in STABS_DEBUG. Split it out into a
new macro named ELF_DETAILS. This will gain other non-debug sections
that need to be accounted for when linking with --orphan-handling=warn.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: linux-arch@vger.kernel.org
Link: https://lore.kernel.org/r/20200821194310.3089815-5-keescook@chromium.org

KASAN (-fsanitize=kernel-address) and KCSAN (-fsanitize=thread)
produce unwanted[1] .eh_frame and .init_array.* sections. Add them to
COMMON_DISCARDS, except with CONFIG_CONSTRUCTORS, which wants to keep
.init_array.* sections.

[1] https://bugs.llvm.org/show_bug.cgi?id=46478Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Marco Elver <elver@google.com>
Cc: linux-arch@vger.kernel.org
Link: https://lore.kernel.org/r/20200821194310.3089815-4-keescook@chromium.org

For vmlinux linking, no architecture uses the .gnu.version* sections,
so remove it via the COMMON_DISCARDS macro in preparation for adding
--orphan-handling=warn more widely. This is a work-around for what
appears to be a bug[1] in ld.bfd which warns for this synthetic section
even when none is found in input objects, and even when no section is
emitted for an output object[2].

[1] https://sourceware.org/bugzilla/show_bug.cgi?id=26153
[2] https://lore.kernel.org/lkml/202006221524.CEB86E036B@keescook/Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Fangrui Song <maskray@google.com>
Cc: linux-arch@vger.kernel.org
Link: https://lore.kernel.org/r/20200821194310.3089815-3-keescook@chromium.org

Collect the common DISCARD sections for architectures that need more
specialized discard control than what the standard DISCARDS section
provides.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: linux-arch@vger.kernel.org
Link: https://lore.kernel.org/r/20200821194310.3089815-2-keescook@chromium.org

Add a linker script check that there are no run-time relocations, and
remove the old one that tries to check via looking for specially-named
sections in the object files.

Drop the tests for -fPIE compiler option and -pie linker option, as they
are available in all supported gcc and binutils versions (as well as
clang and lld).
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Fangrui Song <maskray@google.com>
Reviewed-by: Sedat Dilek <sedat.dilek@gmail.com>
Link: https://lore.kernel.org/r/20200731230820.1742553-8-keescook@chromium.org

The BFD linker generates run-time relocations for z_input_len and
z_output_len, even though they are absolute symbols.

This is fixed for binutils-2.35 [1]. Work around this for earlier
versions by defining two variables input_len and output_len in addition
to the symbols, and use them via position-independent references.

This eliminates the last two run-time relocations in the head code and
allows us to drop the -z noreloc-overflow flag to the linker.

Move the -pie and --no-dynamic-linker LDFLAGS to LDFLAGS_vmlinux instead
of KBUILD_LDFLAGS. There shouldn't be anything else getting linked, but
this is the more logical location for these flags, and modversions might
call the linker if an EXPORT_SYMBOL is left over accidentally in one of
the decompressors.

[1] https://sourceware.org/bugzilla/show_bug.cgi?id=25754Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Fangrui Song <maskray@google.com>
Link: https://lore.kernel.org/r/20200731230820.1742553-7-keescook@chromium.org

The assembly code in head_{32,64}.S, while meant to be
position-independent, generates run-time relocations because it uses
instructions such as:

	leal	gdt(%edx), %eax

which make the assembler and linker think that the code is using %edx as
an index into gdt, and hence gdt needs to be relocated to its run-time
address.

On 32-bit, with lld Dmitry Golovin reports that this results in a
link-time error with default options (i.e. unless -z notext is
explicitly passed):

  LD      arch/x86/boot/compressed/vmlinux
  ld.lld: error: can't create dynamic relocation R_386_32 against local
  symbol in readonly segment; recompile object files with -fPIC or pass
  '-Wl,-z,notext' to allow text relocations in the output

With the BFD linker, this generates a warning during the build, if
--warn-shared-textrel is enabled, which at least Gentoo enables by
default:

  LD      arch/x86/boot/compressed/vmlinux
  ld: arch/x86/boot/compressed/head_32.o: warning: relocation in read-only section `.head.text'
  ld: warning: creating a DT_TEXTREL in object

On 64-bit, it is not possible to link the kernel as -pie with lld, and
it is only possible with a BFD linker that supports -z noreloc-overflow,
i.e. versions >2.26. This is because these instructions cannot really be
relocated: the displacement field is only 32-bits wide, and thus cannot
be relocated for a 64-bit load address. The -z noreloc-overflow option
simply overrides the linker error, and results in R_X86_64_RELATIVE
relocations that apply a 64-bit relocation to a 32-bit field anyway.
This happens to work because nothing will process these run-time
relocations.

Start fixing this by removing relocations from .head.text:

- On 32-bit, use a base register that holds the address of the GOT and
  reference symbol addresses using @GOTOFF, i.e.
	leal	gdt@GOTOFF(%edx), %eax

- On 64-bit, most of the code can (and already does) use %rip-relative
  addressing, however the .code32 bits can't, and the 64-bit code also
  needs to reference symbol addresses as they will be after moving the
  compressed kernel to the end of the decompression buffer.
  For these cases, reference the symbols as an offset to startup_32 to
  avoid creating relocations, i.e.:

	leal	(gdt-startup_32)(%bp), %eax

  This only works in .head.text as the subtraction cannot be represented
  as a PC-relative relocation unless startup_32 is in the same section
  as the code. Move efi32_pe_entry into .head.text so that it can use
  the same method to avoid relocations.
Reported-by: Dmitry Golovin <dima@golovin.in>
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Fangrui Song <maskray@google.com>
Link: https://lore.kernel.org/r/20200731230820.1742553-6-keescook@chromium.org

GCC puts the main function into .text.startup when compiled with -Os (or
-O2). This results in arch/x86/boot/main.c having a .text.startup
section which is currently not included explicitly in the linker script
setup.ld in the same directory.

The BFD linker places this orphan section immediately after .text, so
this still works. However, LLD git, since [1], is choosing to place it
immediately after the .bstext section instead (this is the first code
section). This plays havoc with the section layout that setup.elf
requires to create the setup header, for eg on 64-bit:

    LD      arch/x86/boot/setup.elf
  ld.lld: error: section .text.startup file range overlaps with .header
  >>> .text.startup range is [0x200040, 0x2001FE]
  >>> .header range is [0x2001EF, 0x20026B]

  ld.lld: error: section .header file range overlaps with .bsdata
  >>> .header range is [0x2001EF, 0x20026B]
  >>> .bsdata range is [0x2001FF, 0x200398]

  ld.lld: error: section .bsdata file range overlaps with .entrytext
  >>> .bsdata range is [0x2001FF, 0x200398]
  >>> .entrytext range is [0x20026C, 0x2002D3]

  ld.lld: error: section .text.startup virtual address range overlaps
  with .header
  >>> .text.startup range is [0x40, 0x1FE]
  >>> .header range is [0x1EF, 0x26B]

  ld.lld: error: section .header virtual address range overlaps with
  .bsdata
  >>> .header range is [0x1EF, 0x26B]
  >>> .bsdata range is [0x1FF, 0x398]

  ld.lld: error: section .bsdata virtual address range overlaps with
  .entrytext
  >>> .bsdata range is [0x1FF, 0x398]
  >>> .entrytext range is [0x26C, 0x2D3]

  ld.lld: error: section .text.startup load address range overlaps with
  .header
  >>> .text.startup range is [0x40, 0x1FE]
  >>> .header range is [0x1EF, 0x26B]

  ld.lld: error: section .header load address range overlaps with
  .bsdata
  >>> .header range is [0x1EF, 0x26B]
  >>> .bsdata range is [0x1FF, 0x398]

  ld.lld: error: section .bsdata load address range overlaps with
  .entrytext
  >>> .bsdata range is [0x1FF, 0x398]
  >>> .entrytext range is [0x26C, 0x2D3]

Add .text.* to the .text output section to fix this, and also prevent
any future surprises if the compiler decides to create other such
sections.

[1] https://reviews.llvm.org/D75225Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Fangrui Song <maskray@google.com>
Link: https://lore.kernel.org/r/20200731230820.1742553-5-keescook@chromium.org

In a previous patch, we have eliminated GOT entries from the decompressor
binary and added an assertion that the .got section is empty. This means
that the GOT fixup routines that exist in both the 32-bit and 64-bit
startup routines have become dead code, and can be removed.

While at it, drop the KEEP() from the linker script, as it has no effect
on the contents of output sections that are created by the linker itself.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Arvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200731230820.1742553-4-keescook@chromium.org

Eliminate all GOT entries in the decompressor binary, by forcing hidden
visibility for all symbol references, which informs the compiler that
such references will be resolved at link time without the need for
allocating GOT entries.

To ensure that no GOT entries will creep back in, add an assertion to
the decompressor linker script that will fire if the .got section has
a non-zero size.

[Arvind: move hidden.h to include/linux instead of making a copy]
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Arvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200731230820.1742553-3-keescook@chromium.org

The .got.plt section contains the part of the GOT which is used by PLT
entries, and which gets updated lazily by the dynamic loader when
function calls are dispatched through those PLT entries.

On fully linked binaries such as the kernel proper or the decompressor,
this never happens, and so in practice, the .got.plt section consists
only of the first 3 magic entries that are meant to point at the _DYNAMIC
section and at the fixup routine in the loader. However, since we don't
use a dynamic loader, those entries are never populated or used.

This means that treating those entries like ordinary GOT entries, and
updating their values based on the actual placement of the executable in
memory is completely pointless, and we can just ignore the .got.plt
section entirely, provided that it has no additional entries beyond
the first 3 ones.

So add an assertion in the linker script to ensure that this assumption
holds, and move the contents out of the [_got, _egot) memory range that
is modified by the GOT fixup routines.

While at it, drop the KEEP(), since it has no effect on the contents
of output sections that are created by the linker itself.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Arvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200731230820.1742553-2-keescook@chromium.org

Pull RTC updates from Alexandre Belloni:
 "Not much this cycle - mostly non urgent driver fixes:

   - ds1374: use watchdog core

   - pcf2127: add alarm and pcf2129 support"

* tag 'rtc-5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux:
  rtc: pcf2127: fix alarm handling
  rtc: pcf2127: add alarm support
  rtc: pcf2127: add pca2129 device id
  rtc: max77686: Fix wake-ups for max77620
  rtc: ds1307: provide an indication that the watchdog has fired
  rtc: ds1374: remove unused define
  rtc: ds1374: fix RTC_DRV_DS1374_WDT dependencies
  rtc: cleanup obsolete comment about struct rtc_class_ops
  rtc: pl031: fix set_alarm by adding back call to alarm_irq_enable
  rtc: ds1374: wdt: Use watchdog core for watchdog part
  rtc: Replace HTTP links with HTTPS ones
  rtc: goldfish: Enable interrupt in set_alarm() when necessary
  rtc: max77686: Do not allow interrupt to fire before system resume
  rtc: imxdi: fix trivial typos
  rtc: cpcap: fix range

Pull ceph updates from Ilya Dryomov:
 "Xiubo has completed his work on filesystem client metrics, they are
  sent to all available MDSes once per second now.

  Other than that, we have a lot of fixes and cleanups all around the
  filesystem, including a tweak to cut down on MDS request resends in
  multi-MDS setups from Yanhu and fixups for SELinux symlink labeling
  and MClientSession message decoding from Jeff"

* tag 'ceph-for-5.9-rc1' of git://github.com/ceph/ceph-client: (22 commits)
  ceph: handle zero-length feature mask in session messages
  ceph: use frag's MDS in either mode
  ceph: move sb->wb_pagevec_pool to be a global mempool
  ceph: set sec_context xattr on symlink creation
  ceph: remove redundant initialization of variable mds
  ceph: fix use-after-free for fsc->mdsc
  ceph: remove unused variables in ceph_mdsmap_decode()
  ceph: delete repeated words in fs/ceph/
  ceph: send client provided metric flags in client metadata
  ceph: periodically send perf metrics to MDSes
  ceph: check the sesion state and return false in case it is closed
  libceph: replace HTTP links with HTTPS ones
  ceph: remove unnecessary cast in kfree()
  libceph: just have osd_req_op_init() return a pointer
  ceph: do not access the kiocb after aio requests
  ceph: clean up and optimize ceph_check_delayed_caps()
  ceph: fix potential mdsc use-after-free crash
  ceph: switch to WARN_ON_ONCE in encode_supported_features()
  ceph: add global total_caps to count the mdsc's total caps number
  ceph: add check_session_state() helper and make it global
  ...

Pull more parisc updates from Helge Deller:

 - Oscar Carter contributed a patch which fixes parisc's usage of
   dereference_function_descriptor() and thus will allow using the
   -Wcast-function-type compiler option in the top-level Makefile

 - Sven Schnelle fixed a bug in the SBA code to prevent crashes during
   kexec

 - John David Anglin provided implementations for __smp_store_release()
   and __smp_load_acquire barriers() which avoids using the sync
   assembler instruction and thus speeds up barrier paths

 - Some whitespace cleanups in parisc's atomic.h header file

* 'parisc-5.9-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Implement __smp_store_release and __smp_load_acquire barriers
  parisc: mask out enable and reserved bits from sba imask
  parisc: Whitespace cleanups in atomic.h
  parisc/kernel/ftrace: Remove function callback casts
  sections.h: dereference_function_descriptor() returns void pointer

Pull more KVM updates from Paolo Bonzini:
 "PPC:
   - Improvements and bugfixes for secure VM support, giving reduced
     startup time and memory hotplug support.

   - Locking fixes in nested KVM code

   - Increase number of guests supported by HV KVM to 4094

   - Preliminary POWER10 support

  ARM:
   - Split the VHE and nVHE hypervisor code bases, build the EL2 code
     separately, allowing for the VHE code to now be built with
     instrumentation

   - Level-based TLB invalidation support

   - Restructure of the vcpu register storage to accomodate the NV code

   - Pointer Authentication available for guests on nVHE hosts

   - Simplification of the system register table parsing

   - MMU cleanups and fixes

   - A number of post-32bit cleanups and other fixes

  MIPS:
   - compilation fixes

  x86:
   - bugfixes

   - support for the SERIALIZE instruction"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (70 commits)
  KVM: MIPS/VZ: Fix build error caused by 'kvm_run' cleanup
  x86/kvm/hyper-v: Synic default SCONTROL MSR needs to be enabled
  MIPS: KVM: Convert a fallthrough comment to fallthrough
  MIPS: VZ: Only include loongson_regs.h for CPU_LOONGSON64
  x86: Expose SERIALIZE for supported cpuid
  KVM: x86: Don't attempt to load PDPTRs when 64-bit mode is enabled
  KVM: arm64: Move S1PTW S2 fault logic out of io_mem_abort()
  KVM: arm64: Don't skip cache maintenance for read-only memslots
  KVM: arm64: Handle data and instruction external aborts the same way
  KVM: arm64: Rename kvm_vcpu_dabt_isextabt()
  KVM: arm: Add trace name for ARM_NISV
  KVM: arm64: Ensure that all nVHE hyp code is in .hyp.text
  KVM: arm64: Substitute RANDOMIZE_BASE for HARDEN_EL2_VECTORS
  KVM: arm64: Make nVHE ASLR conditional on RANDOMIZE_BASE
  KVM: PPC: Book3S HV: Rework secure mem slot dropping
  KVM: PPC: Book3S HV: Move kvmppc_svm_page_out up
  KVM: PPC: Book3S HV: Migrate hot plugged memory
  KVM: PPC: Book3S HV: In H_SVM_INIT_DONE, migrate remaining normal-GFNs to secure-GFNs
  KVM: PPC: Book3S HV: Track the state GFNs associated with secure VMs
  KVM: PPC: Book3S HV: Disable page merging in H_SVM_INIT_START
  ...

Pull more clk updates from Stephen Boyd:
 "Here's some more updates that missed the last pull request because I
  happened to tag the tree at an earlier point in the history of
  clk-next. I must have fat fingered it and checked out an older version
  of clk-next on this second computer I'm using.

  This time it actually includes more code for Qualcomm SoCs, the AT91
  major updates, and some Rockchip SoC clk driver updates as well. I've
  corrected this flow so this shouldn't happen again"

* tag 'clk-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux: (83 commits)
  clk: bcm2835: Do not use prediv with bcm2711's PLLs
  clk: drop unused function __clk_get_flags
  clk: hsdk: Fix bad dependency on IOMEM
  dt-bindings: clock: Fix YAML schemas for LPASS clocks on SC7180
  clk: mmp: avoid missing prototype warning
  clk: sparx5: Add Sparx5 SoC DPLL clock driver
  dt-bindings: clock: sparx5: Add bindings include file
  clk: qoriq: add LS1021A core pll mux options
  clk: clk-atlas6: fix return value check in atlas6_clk_init()
  clk: tegra: pll: Improve PLLM enable-state detection
  clk: X1000: Add support for calculat REFCLK of USB PHY.
  clk: JZ4780: Reformat the code to align it.
  clk: JZ4780: Add functions for enable and disable USB PHY.
  clk: Ingenic: Add RTC related clocks for Ingenic SoCs.
  dt-bindings: clock: Add tabs to align code.
  dt-bindings: clock: Add RTC related clocks for Ingenic SoCs.
  clk: davinci: Use fallthrough pseudo-keyword
  clk: imx: Use fallthrough pseudo-keyword
  clk: qcom: gcc-sdm660: Fix up gcc_mss_mnoc_bimc_axi_clk
  clk: qcom: gcc-sdm660: Add missing modem reset
  ...

Pull watchdog updates from Wim Van Sebroeck:

 - f71808e_wdt imporvements

 - dw_wdt improvements

 - mlx-wdt: support new watchdog type with longer timeout period

 - fallthrough pseudo-keyword replacements

 - overall small fixes and improvements

* tag 'linux-watchdog-5.9-rc1' of git://www.linux-watchdog.org/linux-watchdog: (35 commits)
  watchdog: rti-wdt: balance pm runtime enable calls
  watchdog: rti-wdt: attach to running watchdog during probe
  watchdog: add support for adjusting last known HW keepalive time
  watchdog: use __watchdog_ping in startup
  watchdog: softdog: Add options 'soft_reboot_cmd' and 'soft_active_on_boot'
  watchdog: pcwd_usb: remove needless check before usb_free_coherent()
  watchdog: Replace HTTP links with HTTPS ones
  dt-bindings: watchdog: renesas,wdt: Document r8a774e1 support
  watchdog: initialize device before misc_register
  watchdog: booke_wdt: Add common nowayout parameter driver
  watchdog: scx200_wdt: Use fallthrough pseudo-keyword
  watchdog: Use fallthrough pseudo-keyword
  watchdog: f71808e_wdt: do stricter parameter validation
  watchdog: f71808e_wdt: clear watchdog timeout occurred flag
  watchdog: f71808e_wdt: remove use of wrong watchdog_info option
  watchdog: f71808e_wdt: indicate WDIOF_CARDRESET support in watchdog_info.options
  docs: watchdog: codify ident.options as superset of possible status flags
  dt-bindings: watchdog: Add compatible for QCS404, SC7180, SDM845, SM8150
  dt-bindings: watchdog: Convert QCOM watchdog timer bindings to YAML
  watchdog: dw_wdt: Add DebugFS files
  ...

Pull VFIO updates from Alex Williamson:

 - Inclusive naming updates (Alex Williamson)

 - Intel X550 INTx quirk (Alex Williamson)

 - Error path resched between unmaps (Xiang Zheng)

 - SPAPR IOMMU pin_user_pages() conversion (John Hubbard)

 - Trivial mutex simplification (Alex Williamson)

 - QAT device denylist (Giovanni Cabiddu)

 - type1 IOMMU ioctl refactor (Liu Yi L)

* tag 'vfio-v5.9-rc1' of git://github.com/awilliam/linux-vfio:
  vfio/type1: Refactor vfio_iommu_type1_ioctl()
  vfio/pci: Add QAT devices to denylist
  vfio/pci: Add device denylist
  PCI: Add Intel QuickAssist device IDs
  vfio/pci: Hold igate across releasing eventfd contexts
  vfio/spapr_tce: convert get_user_pages() --> pin_user_pages()
  vfio/type1: Add conditional rescheduling after iommu map failed
  vfio/pci: Add Intel X550 to hidden INTx devices
  vfio: Cleanup allowed driver naming

Pull drm fixes from Dave Airlie:
 "This has a few vmwgfx regression fixes we hit from the merge window
  (one in TTM), it also has a bunch of amdgpu fixes along with a
  scattering everywhere else.

  core:
   - Fix drm_dp_mst_port refcount leaks in drm_dp_mst_allocate_vcpi
   - Remove null check for kfree in drm_dev_release.
   - Fix DRM_FORMAT_MOD_AMLOGIC_FBC definition.
   - re-added docs for drm_gem_flink_ioctl()
   - add orientation quirk for ASUS T103HAF

  ttm:
   - ttm: fix page-offset calculation within TTM
   - revert patch causing vmwgfx regressions

  fbcon:
   - Fix a fbcon OOB read in fbdev, found by syzbot.

  vga:
   - Mark vga_tryget static as it's not used elsewhere.

  amdgpu:
   - Re-add spelling typo fix
   - Sienna Cichlid fixes
   - Navy Flounder fixes
   - DC fixes
   - SMU i2c fix
   - Power fixes

  vmwgfx:
   - regression fixes for modesetting crashes
   - misc fixes

  xlnx:
   - Small fixes to xlnx.

  omap:
   - Fix mode initialization in omap_connector_mode_valid().
   - force runtime PM suspend on system suspend

  tidss:
   - fix modeset init for DPI panels"

* tag 'drm-next-2020-08-12' of git://anongit.freedesktop.org/drm/drm: (70 commits)
  drm/ttm: revert "drm/ttm: make TT creation purely optional v3"
  drm/vmwgfx: fix spelling mistake "Cant" -> "Can't"
  drm/vmwgfx: fix spelling mistake "Cound" -> "Could"
  drm/vmwgfx/ldu: Use drm_mode_config_reset
  drm/vmwgfx/sou: Use drm_mode_config_reset
  drm/vmwgfx/stdu: Use drm_mode_config_reset
  drm/vmwgfx: Fix two list_for_each loop exit tests
  drm/vmwgfx: Use correct vmw_legacy_display_unit pointer
  drm/vmwgfx: Use struct_size() helper
  drm/amdgpu: Fix bug where DPM is not enabled after hibernate and resume
  drm/amd/powerplay: put VCN/JPEG into PG ungate state before dpm table setup(V3)
  drm/amd/powerplay: update swSMU VCN/JPEG PG logics
  drm/amdgpu: use mode1 reset by default for sienna_cichlid
  drm/amdgpu/smu: rework i2c adpater registration
  drm/amd/display: Display goes blank after inst
  drm/amd/display: Change null plane state swizzle mode to 4kb_s
  drm/amd/display: Use helper function to check for HDMI signal
  drm/amd/display: AMD OUI (DPCD 0x00300) skipped on some sink
  drm/amd/display: Fix logger context
  drm/amd/display: populate new dml variable
  ...

Merge more updates from Andrew Morton:

 - most of the rest of MM (memcg, hugetlb, vmscan, proc, compaction,
   mempolicy, oom-kill, hugetlbfs, migration, thp, cma, util,
   memory-hotplug, cleanups, uaccess, migration, gup, pagemap),

 - various other subsystems (alpha, misc, sparse, bitmap, lib, bitops,
   checkpatch, autofs, minix, nilfs, ufs, fat, signals, kmod, coredump,
   exec, kdump, rapidio, panic, kcov, kgdb, ipc).

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (164 commits)
  mm/gup: remove task_struct pointer for all gup code
  mm: clean up the last pieces of page fault accountings
  mm/xtensa: use general page fault accounting
  mm/x86: use general page fault accounting
  mm/sparc64: use general page fault accounting
  mm/sparc32: use general page fault accounting
  mm/sh: use general page fault accounting
  mm/s390: use general page fault accounting
  mm/riscv: use general page fault accounting
  mm/powerpc: use general page fault accounting
  mm/parisc: use general page fault accounting
  mm/openrisc: use general page fault accounting
  mm/nios2: use general page fault accounting
  mm/nds32: use general page fault accounting
  mm/mips: use general page fault accounting
  mm/microblaze: use general page fault accounting
  mm/m68k: use general page fault accounting
  mm/ia64: use general page fault accounting
  mm/hexagon: use general page fault accounting
  mm/csky: use general page fault accounting
  ...

After the cleanup of page fault accounting, gup does not need to pass
task_struct around any more.  Remove that parameter in the whole gup
stack.
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Link: http://lkml.kernel.org/r/20200707225021.200906-26-peterx@redhat.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Here're the last pieces of page fault accounting that were still done
outside handle_mm_fault() where we still have regs==NULL when calling
handle_mm_fault():

arch/powerpc/mm/copro_fault.c:   copro_handle_mm_fault
arch/sparc/mm/fault_32.c:        force_user_fault
arch/um/kernel/trap.c:           handle_page_fault
mm/gup.c:                        faultin_page
                                 fixup_user_fault
mm/hmm.c:                        hmm_vma_fault
mm/ksm.c:                        break_ksm

Some of them has the issue of duplicated accounting for page fault
retries.  Some of them didn't do the accounting at all.

This patch cleans all these up by letting handle_mm_fault() to do per-task
page fault accounting even if regs==NULL (though we'll still skip the perf
event accountings).  With that, we can safely remove all the outliers now.

There's another functional change in that now we account the page faults
to the caller of gup, rather than the task_struct that passed into the gup
code.  More information of this can be found at [1].

After this patch, below things should never be touched again outside
handle_mm_fault():

  - task_struct.[maj|min]_flt
  - PERF_COUNT_SW_PAGE_FAULTS_[MAJ|MIN]

[1] https://lore.kernel.org/lkml/CAHk-=wj_V2Tps2QrMn20_W0OJF9xqNh52XSGA42s-ZJ8Y+GyKw@mail.gmail.com/Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200707225021.200906-25-peterx@redhat.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Use the general page fault accounting by passing regs into
handle_mm_fault().  It naturally solve the issue of multiple page fault
accounting when page fault retry happened.

Remove the PERF_COUNT_SW_PAGE_FAULTS_[MAJ|MIN] perf events because it's
now also done in handle_mm_fault().

Move the PERF_COUNT_SW_PAGE_FAULTS event higher before taking mmap_sem for
the fault, then it'll match with the rest of the archs.
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Max Filippov <jcmvbkbc@gmail.com>
Cc: Chris Zankel <chris@zankel.net>
Link: http://lkml.kernel.org/r/20200707225021.200906-24-peterx@redhat.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Use the general page fault accounting by passing regs into
handle_mm_fault().
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/r/20200707225021.200906-23-peterx@redhat.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Use the general page fault accounting by passing regs into
handle_mm_fault().  It naturally solve the issue of multiple page fault
accounting when page fault retry happened.
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: David S. Miller <davem@davemloft.net>
Link: http://lkml.kernel.org/r/20200707225021.200906-22-peterx@redhat.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Use the general page fault accounting by passing regs into
handle_mm_fault().  It naturally solve the issue of multiple page fault
accounting when page fault retry happened.
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: David S. Miller <davem@davemloft.net>
Link: http://lkml.kernel.org/r/20200707225021.200906-21-peterx@redhat.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Use the general page fault accounting by passing regs into
handle_mm_fault().  It naturally solve the issue of multiple page fault
accounting when page fault retry happened.
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Link: http://lkml.kernel.org/r/20200707225021.200906-20-peterx@redhat.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Use the general page fault accounting by passing regs into
handle_mm_fault().  It naturally solve the issue of multiple page fault
accounting when page fault retry happened.
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Acked-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Link: http://lkml.kernel.org/r/20200707225021.200906-19-peterx@redhat.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Use the general page fault accounting by passing regs into
handle_mm_fault().  It naturally solve the issue of multiple page fault
accounting when page fault retry happened.
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Pekka Enberg <penberg@kernel.org>
Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Link: http://lkml.kernel.org/r/20200707225021.200906-18-peterx@redhat.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Use the general page fault accounting by passing regs into
handle_mm_fault().
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Link: http://lkml.kernel.org/r/20200707225021.200906-17-peterx@redhat.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Use the general page fault accounting by passing regs into
handle_mm_fault().  It naturally solve the issue of multiple page fault
accounting when page fault retry happened.

Add the missing PERF_COUNT_SW_PAGE_FAULTS perf events too.  Note, the
other two perf events (PERF_COUNT_SW_PAGE_FAULTS_[MAJ|MIN]) were done in
handle_mm_fault().
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Helge Deller <deller@gmx.de>
Link: http://lkml.kernel.org/r/20200707225021.200906-16-peterx@redhat.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Use the general page fault accounting by passing regs into
handle_mm_fault().  It naturally solve the issue of multiple page fault
accounting when page fault retry happened.

Add the missing PERF_COUNT_SW_PAGE_FAULTS perf events too.  Note, the
other two perf events (PERF_COUNT_SW_PAGE_FAULTS_[MAJ|MIN]) were done in
handle_mm_fault().
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Stafford Horne <shorne@gmail.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Link: http://lkml.kernel.org/r/20200707225021.200906-15-peterx@redhat.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>