Merge branch 'kcsan-for-tip' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into locking/kcsan

Pull KCSAN updates from Paul McKenney.

Both are safe to be called from uaccess contexts.
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

The __kcsan_{enable,disable}_current() variants only call into KCSAN if
KCSAN is enabled for the current compilation unit. Note: This is
typically not what we want, as we usually want to ensure that even calls
into other functions still have KCSAN disabled.

These variants may safely be used in header files that are shared
between regular kernel code and code that does not link the KCSAN
runtime.
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

Warn about applications of data_race() without a comment, to encourage
documenting the reasoning behind why it was deemed safe.
Suggested-by: Will Deacon <will@kernel.org>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

A spin lock is held in insert_report_filterlist(), so the krealloc()
should use GFP_ATOMIC.  This commit therefore makes this change.
Reviewed-by: Marco Elver <elver@google.com>
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

This commit simplifies and clarifies the highest level KCSAN Kconfig
help text.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

Reporting hides KCSAN runtime functions in the stack trace, with
filtering done based on function names. Currently this included all
functions (or modules) that would match "kcsan_". Make the filter aware
of KCSAN tests, which contain "kcsan_test", and are no longer skipped in
the report.

This is in preparation for adding a KCSAN test module.
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

Pass string length as returned by scnprintf() to strnstr(), since
strnstr() searches exactly len bytes in haystack, even if it contains a
NUL-terminator before haystack+len.
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

Thus far, accesses marked with data_race() would still require the
racing access to be marked in some way (be it with READ_ONCE(),
WRITE_ONCE(), or data_race() itself), as otherwise KCSAN would still
report a data race.  This requirement, however, seems to be unintuitive,
and some valid use-cases demand *not* marking other accesses, as it
might hide more serious bugs (e.g. diagnostic reads).

Therefore, this commit changes data_race() to no longer require marking
racing accesses (although it's still recommended if possible).

The alternative would have been introducing another variant of
data_race(), however, since usage of data_race() already needs to be
carefully reasoned about, distinguishing between these cases likely adds
more complexity in the wrong place.

Link: https://lkml.kernel.org/r/20200331131002.GA30975@willie-the-truck
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Will Deacon <will@kernel.org>
Cc: Qian Cai <cai@lca.pw>
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

Both affect access checks, and should therefore be in kcsan-checks.h.
This is in preparation to use these in compiler.h.
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

Introduce ASSERT_EXCLUSIVE_*_SCOPED(), which provide an intuitive
interface to use the scoped-access feature, without having to explicitly
mark the start and end of the desired scope. Basing duration of the
checks on scope avoids accidental misuse and resulting false positives,
which may be hard to debug. See added comments for usage.

The macros are implemented using __attribute__((__cleanup__(func))),
which is supported by all compilers that currently support KCSAN.
Suggested-by: Boqun Feng <boqun.feng@gmail.com>
Suggested-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

Add explicitly invoked KCSAN check functions to objtool's uaccess
whitelist. This is needed in order to permit calling into
kcsan_check_scoped_accesses() from the fast-path, which in turn calls
__kcsan_check_access().  __kcsan_check_access() is the generic variant
of the already whitelisted specializations __tsan_{read,write}N.
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

This adds support for scoped accesses, where the memory range is checked
for the duration of the scope. The feature is implemented by inserting
the relevant access information into a list of scoped accesses for
the current execution context, which are then checked (until removed)
on every call (through instrumentation) into the KCSAN runtime.

An alternative, more complex, implementation could set up a watchpoint for
the scoped access, and keep the watchpoint set up. This, however, would
require first exposing a handle to the watchpoint, as well as dealing
with cases such as accesses by the same thread while the watchpoint is
still set up (and several more cases). It is also doubtful if this would
provide any benefit, since the majority of delay where the watchpoint
is set up is likely due to the injected delays by KCSAN.  Therefore,
the implementation in this patch is simpler and avoids hurting KCSAN's
main use-case (normal data race detection); it also implicitly increases
scoped-access race-detection-ability due to increased probability of
setting up watchpoints by repeatedly calling __kcsan_check_access()
throughout the scope of the access.

The implementation required adding an additional conditional branch to
the fast-path. However, the microbenchmark showed a *speedup* of ~5%
on the fast-path. This appears to be due to subtly improved codegen by
GCC from moving get_ctx() and associated load of preempt_count earlier.
Suggested-by: Boqun Feng <boqun.feng@gmail.com>
Suggested-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

To avoid deadlock in case watchers can be interrupted, we need to ensure
that producers of the struct other_info can never be blocked by an
unrelated consumer. (Likely to occur with KCSAN_INTERRUPT_WATCHER.)

There are several cases that can lead to this scenario, for example:

	1. A watchpoint A was set up by task T1, but interrupted by
	   interrupt I1. Some other thread (task or interrupt) finds
	   watchpoint A consumes it, and sets other_info. Then I1 also
	   finds some unrelated watchpoint B, consumes it, but is blocked
	   because other_info is in use. T1 cannot consume other_info
	   because I1 never returns -> deadlock.

	2. A watchpoint A was set up by task T1, but interrupted by
	   interrupt I1, which also sets up a watchpoint B. Some other
	   thread finds watchpoint A, and consumes it and sets up
	   other_info with its information. Similarly some other thread
	   finds watchpoint B and consumes it, but is then blocked because
	   other_info is in use. When I1 continues it sees its watchpoint
	   was consumed, and that it must wait for other_info, which
	   currently contains information to be consumed by T1. However, T1
	   cannot unblock other_info because I1 never returns -> deadlock.

To avoid this, we need to ensure that producers of struct other_info
always have a usable other_info entry. This is obviously not the case
with only a single instance of struct other_info, as concurrent
producers must wait for the entry to be released by some consumer (which
may be locked up as illustrated above).

While it would be nice if producers could simply call kmalloc() and
append their instance of struct other_info to a list, we are very
limited in this code path: since KCSAN can instrument the allocators
themselves, calling kmalloc() could lead to deadlock or corrupted
allocator state.

Since producers of the struct other_info will always succeed at
try_consume_watchpoint(), preceding the call into kcsan_report(), we
know that the particular watchpoint slot cannot simply be reused or
consumed by another potential other_info producer. If we move removal of
a watchpoint after reporting (by the consumer of struct other_info), we
can see a consumed watchpoint as a held lock on elements of other_info,
if we create a one-to-one mapping of a watchpoint to an other_info
element.

Therefore, the simplest solution is to create an array of struct
other_info that is as large as the watchpoints array in core.c, and pass
the watchpoint index to kcsan_report() for producers and consumers, and
change watchpoints to be removed after reporting is done.

With a default config on a 64-bit system, the array other_infos consumes
~37KiB. For most systems today this is not a problem. On smaller memory
constrained systems, the config value CONFIG_KCSAN_NUM_WATCHPOINTS can
be reduced appropriately.

Overall, this change is a simplification of the prepare_report() code,
and makes some of the checks (such as checking if at least one access is
a write) redundant.

Tested:
$ tools/testing/selftests/rcutorture/bin/kvm.sh \
	--cpus 12 --duration 10 --kconfig "CONFIG_DEBUG_INFO=y \
	CONFIG_KCSAN=y CONFIG_KCSAN_ASSUME_PLAIN_WRITES_ATOMIC=n \
	CONFIG_KCSAN_REPORT_VALUE_CHANGE_ONLY=n \
	CONFIG_KCSAN_REPORT_ONCE_IN_MS=100000 CONFIG_KCSAN_VERBOSE=y \
	CONFIG_KCSAN_INTERRUPT_WATCHER=y CONFIG_PROVE_LOCKING=y" \
	--configs TREE03
=> No longer hangs and runs to completion as expected.
Reported-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

Improve readability by introducing access_info and other_info structs,
and in preparation of the following commit in this series replaces the
single instance of other_info with an array of size 1.

No functional change intended.
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

Resolve these conflicts:

	arch/x86/Kconfig
	arch/x86/kernel/Makefile

Do a minor "evil merge" to move the KCSAN entry up a bit by a few lines
in the Kconfig to reduce the probability of future conflicts.
Signed-off-by: Ingo Molnar <mingo@kernel.org>

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>

Another brown paper bag moment. pnfs_alloc_ds_commits_list() is leaking
the RCU lock.

Fixes: a9901899 ("pNFS: Add infrastructure for cleaning up per-layout commit structures")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

Two types of #AC can be generated in Intel CPUs:
 1. legacy alignment check #AC
 2. split lock #AC

Reflect #AC back into the guest if the guest has legacy alignment checks
enabled or if split lock detection is disabled.

If the #AC is not a legacy one and split lock detection is enabled, then
invoke handle_guest_split_lock() which will either warn and disable split
lock detection for this task or force SIGBUS on it.

[ tglx: Switch it to handle_guest_split_lock() and rename the misnamed
  helper function. ]
Suggested-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Link: https://lkml.kernel.org/r/20200410115517.176308876@linutronix.de

Emulate split-lock accesses as writes if split lock detection is on
to avoid #AC during emulation, which will result in a panic(). This
should never occur for a well-behaved guest, but a malicious guest can
manipulate the TLB to trigger emulation of a locked instruction[1].

More discussion can be found at [2][3].

[1] https://lkml.kernel.org/r/8c5b11c9-58df-38e7-a514-dc12d687b198@redhat.com
[2] https://lkml.kernel.org/r/20200131200134.GD18946@linux.intel.com
[3] https://lkml.kernel.org/r/20200227001117.GX9940@linux.intel.comSuggested-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Link: https://lkml.kernel.org/r/20200410115517.084300242@linutronix.de

Without at least minimal handling for split lock detection induced #AC,
VMX will just run into the same problem as the VMWare hypervisor, which
was reported by Kenneth.

It will inject the #AC blindly into the guest whether the guest is
prepared or not.

Provide a function for guest mode which acts depending on the host
SLD mode. If mode == sld_warn, treat it like user space, i.e. emit a
warning, disable SLD and mark the task accordingly. Otherwise force
SIGBUS.

 [ bp: Add a !CPU_SUP_INTEL stub for handle_guest_split_lock(). ]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Link: https://lkml.kernel.org/r/20200410115516.978037132@linutronix.de
Link: https://lkml.kernel.org/r/20200402123258.895628824@linutronix.de

The keyword here is 'twice' to explain the trick.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Merge yet more updates from Andrew Morton:

 - Almost all of the rest of MM (memcg, slab-generic, slab, pagealloc,
   gup, hugetlb, pagemap, memremap)

 - Various other things (hfs, ocfs2, kmod, misc, seqfile)

* akpm: (34 commits)
  ipc/util.c: sysvipc_find_ipc() should increase position index
  kernel/gcov/fs.c: gcov_seq_next() should increase position index
  fs/seq_file.c: seq_read(): add info message about buggy .next functions
  drivers/dma/tegra20-apb-dma.c: fix platform_get_irq.cocci warnings
  change email address for Pali Rohár
  selftests: kmod: test disabling module autoloading
  selftests: kmod: fix handling test numbers above 9
  docs: admin-guide: document the kernel.modprobe sysctl
  fs/filesystems.c: downgrade user-reachable WARN_ONCE() to pr_warn_once()
  kmod: make request_module() return an error when autoloading is disabled
  mm/memremap: set caching mode for PCI P2PDMA memory to WC
  mm/memory_hotplug: add pgprot_t to mhp_params
  powerpc/mm: thread pgprot_t through create_section_mapping()
  x86/mm: introduce __set_memory_prot()
  x86/mm: thread pgprot_t through init_memory_mapping()
  mm/memory_hotplug: rename mhp_restrictions to mhp_params
  mm/memory_hotplug: drop the flags field from struct mhp_restrictions
  mm/special: create generic fallbacks for pte_special() and pte_mkspecial()
  mm/vma: introduce VM_ACCESS_FLAGS
  mm/vma: define a default value for VM_DATA_DEFAULT_FLAGS
  ...

Pull Documentation fixes from Jonathan Corbet:
 "A handful of late-arriving fixes for the documentation tree"

* tag 'docs-5.7-2' of git://git.lwn.net/linux:
  Documentation: android: binderfs: add 'stats' mount option
  Documentation: driver-api/usb/writing_usb_driver.rst Updates documentation links
  docs: driver-api: address duplicate label warning
  Documentation: sysrq: fix RST formatting
  docs: kernel-parameters.txt: Fix broken references
  docs: kernel-parameters.txt: Remove nompx
  docs: filesystems: fix typo in qnx6.rst

Pull orangefs updates from Mike Marshall:
 "A fix and two cleanups.

  Fix:

   - Christoph Hellwig noticed that some logic I added to
     orangefs_file_read_iter introduced a race condition, so he sent a
     reversion patch. I had to modify his patch since reverting at this
     point broke Orangefs.

  Cleanups:

   - Christoph Hellwig noticed that we were doing some unnecessary work
     in orangefs_flush, so he sent in a patch that removed the un-needed
     code.

   - Al Viro told me he had trouble building Orangefs. Orangefs should
     be easy to build, even for Al :-).

     I looked back at the test server build notes in orangefs.txt, just
     in case that's where the trouble really is, and found a couple of
     typos and made a couple of clarifications"

* tag 'for-linus-5.7-ofs1' of git://git.kernel.org/pub/scm/linux/kernel/git/hubcap/linux:
  orangefs: clarify build steps for test server in orangefs.txt
  orangefs: don't mess with I_DIRTY_TIMES in orangefs_flush
  orangefs: get rid of knob code...

Pull xtensa updates from Max Filippov:

 - replace setup_irq() by request_irq()

 - cosmetic fixes in xtensa Kconfig and boot/Makefile

* tag 'xtensa-20200410' of git://github.com/jcmvbkbc/linux-xtensa:
  arch/xtensa: fix grammar in Kconfig help text
  xtensa: remove meaningless export ccflags-y
  xtensa: replace setup_irq() by request_irq()

Pull more xen updates from Juergen Gross:

 - two cleanups

 - fix a boot regression introduced in this merge window

 - fix wrong use of memory allocation flags

* tag 'for-linus-5.7-rc1b-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  x86/xen: fix booting 32-bit pv guest
  x86/xen: make xen_pvmmu_arch_setup() static
  xen/blkfront: fix memory allocation flags in blkfront_setup_indirect()
  xen: Use evtchn_type_t as a type for event channels