* pm-cpuidle:
  intel_idle: Fix max_cstate for processor models without C-state tables

* pm-sleep:
  PM: sleep: fix typo in kernel/power/process.c

Because sugov_update_next_freq() may skip a frequency update even if
the need_freq_update flag has been set for the policy at hand, policy
limits updates may not take effect as expected.

For example, if the intel_pstate driver operates in the passive mode
with HWP enabled, it needs to update the HWP min and max limits when
the policy min and max limits change, respectively, but that may not
happen if the target frequency does not change along with the limit
at hand.  In particular, if the policy min is changed first, causing
the target frequency to be adjusted to it, and the policy max limit
is changed later to the same value, the HWP max limit will not be
updated to follow it as expected, because the target frequency is
still equal to the policy min limit and it will not change until
that limit is updated.

To address this issue, modify get_next_freq() to let the driver
callback run if the CPUFREQ_NEED_UPDATE_LIMITS cpufreq driver flag
is set regardless of whether or not the new frequency to set is
equal to the previous one.

Fixes: f6ebbcf0 ("cpufreq: intel_pstate: Implement passive mode with HWP enabled")
Reported-by: Zhang Rui <rui.zhang@intel.com>
Tested-by: Zhang Rui <rui.zhang@intel.com>
Cc: 5.9+ <stable@vger.kernel.org> # 5.9+: 1c534352 cpufreq: Introduce CPUFREQ_NEED_UPDATE_LIMITS ...
Cc: 5.9+ <stable@vger.kernel.org> # 5.9+: a62f68f5 cpufreq: Introduce cpufreq_driver_test_flags()
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Add a helper function to test the flags of the cpufreq driver in use
againt a given flags mask.

In particular, this will be needed to test the
CPUFREQ_NEED_UPDATE_LIMITS cpufreq driver flag in the schedutil
governor.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

A semicolon is not needed after a switch statement.
Signed-off-by: Tom Rix <trix@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Fix a typo in a comment in freeze_processes().
Signed-off-by: Jackie Zamow <jackie.zamow@gmail.com>
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Currently intel_idle driver gets the c-state information from ACPI
_CST if the processor model is not recognized by it. However the
c-state in _CST starts with index 1 which is different from the
index in intel_idle driver's internal c-state table.

While intel_idle_max_cstate_reached() was previously introduced to
deal with intel_idle driver's internal c-state table, re-using
this function directly on _CST is incorrect.

Fix this by subtracting 1 from the index when checking max_cstate
in the _CST case.

For example, append intel_idle.max_cstate=1 in boot command line,
Before the patch:
grep . /sys/devices/system/cpu/cpu0/cpuidle/state*/name
POLL
After the patch:
grep . /sys/devices/system/cpu/cpu0/cpuidle/state*/name
/sys/devices/system/cpu/cpu0/cpuidle/state0/name:POLL
/sys/devices/system/cpu/cpu0/cpuidle/state1/name:C1_ACPI

Fixes: 18734958 ("intel_idle: Use ACPI _CST for processor models without C-state tables")
Reported-by: Pengfei Xu <pengfei.xu@intel.com>
Cc: 5.6+ <stable@vger.kernel.org> # 5.6+
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
[ rjw: Changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

If the cpufreq policy max limit is changed when intel_pstate operates
in the passive mode with HWP enabled and the "powersave" governor is
used on top of it, the HWP max limit is not updated as appropriate.

Namely, in the "powersave" governor case, the target P-state
is always equal to the policy min limit, so if the latter does
not change, intel_cpufreq_adjust_hwp() is not invoked to update
the HWP Request MSR due to the "target_pstate != old_pstate" check
in intel_cpufreq_update_pstate(), so the HWP max limit is not
updated as a result.

Also, if the CPUFREQ_NEED_UPDATE_LIMITS flag is not set for the
driver and the target frequency does not change along with the
policy max limit, the "target_freq == policy->cur" check in
__cpufreq_driver_target() prevents the driver's ->target() callback
from being invoked at all, so the HWP max limit is not updated.

To prevent that occurring, set the CPUFREQ_NEED_UPDATE_LIMITS flag
in the intel_cpufreq driver structure if HWP is enabled and modify
intel_cpufreq_update_pstate() to do the "target_pstate != old_pstate"
check only in the non-HWP case and let intel_cpufreq_adjust_hwp()
always run in the HWP case (it will update HWP Request only if the
cached value of the register is different from the new one including
the limits, so if neither the target P-state value nor the max limit
changes, the register write will still be avoided).

Fixes: f6ebbcf0 ("cpufreq: intel_pstate: Implement passive mode with HWP enabled")
Reported-by: Zhang Rui <rui.zhang@intel.com>
Cc: 5.9+ <stable@vger.kernel.org> # 5.9+: 1c534352 cpufreq: Introduce CPUFREQ_NEED_UPDATE_LIMITS ...
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Tested-by: Zhang Rui <rui.zhang@intel.com>

Generally, a cpufreq driver may need to update some internal upper
and lower frequency boundaries on policy max and min changes,
respectively, but currently this does not work if the target
frequency does not change along with the policy limit.

Namely, if the target frequency does not change along with the
policy min or max, the "target_freq == policy->cur" check in
__cpufreq_driver_target() prevents driver callbacks from being
invoked and they do not even have a chance to update the
corresponding internal boundary.

This particularly affects the "powersave" and "performance"
governors that always set the target frequency to one of the
policy limits and it never changes when the other limit is updated.

To allow cpufreq the drivers needing to update internal frequency
boundaries on policy limits changes to avoid this issue, introduce
a new driver flag, CPUFREQ_NEED_UPDATE_LIMITS, that (when set) will
neutralize the check mentioned above.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>

Commit 33aa46f2 ("cpufreq: intel_pstate: Use passive mode by
default without HWP") was meant to cause intel_pstate to be used
in the passive mode with the schedutil governor on top of it, but
it missed the case in which either "ondemand" or "conservative"
was selected as the default governor in the existing kernel config,
in which case the previous old governor configuration would be used,
causing the default legacy governor to be used on top of intel_pstate
instead of schedutil.

Address this by preventing "ondemand" and "conservative" from being
configured as the default cpufreq governor in the case when schedutil
is the default choice for the default governor setting.

[Note that the default cpufreq governor can still be set via the
 kernel command line if need be and that choice is not limited,
 so if anyone really wants to use one of the legacy governors by
 default, it can be achieved this way.]

Fixes: 33aa46f2 ("cpufreq: intel_pstate: Use passive mode by default without HWP")
Reported-by: Julia Lawall <julia.lawall@inria.fr>
Cc: 5.8+ <stable@vger.kernel.org> # 5.8+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>

A 'break' following a 'return' statement is pointless, so remove it.
Signed-off-by: Zhang Qilong <zhangqilong3@huawei.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Use a more generic form for __section that requires quotes to avoid
complications with clang and gcc differences.

Remove the quote operator # from compiler_attributes.h __section macro.

Convert all unquoted __section(foo) uses to quoted __section("foo").
Also convert __attribute__((section("foo"))) uses to __section("foo")
even if the __attribute__ has multiple list entry forms.

Conversion done using the script at:

    https://lore.kernel.org/lkml/75393e5ddc272dc7403de74d645e6c6e0f4e70eb.camel@perches.com/2-convert_section.plSigned-off-by: Joe Perches <joe@perches.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@gooogle.com>
Reviewed-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

tid_addr is not a "pointer to (pointer to int in userspace)"; it is in
fact a "pointer to (pointer to int in userspace) in userspace".  So
sparse rightfully complains about passing a kernel pointer to
put_user().
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit 453431a5 ("mm, treewide: rename kzfree() to
kfree_sensitive()") renamed kzfree() to kfree_sensitive(),
but it left a compatibility definition of kzfree() to avoid
being too disruptive.

Since then a few more instances of kzfree() have slipped in.

Just get rid of them and remove the compatibility definition
once and for all.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

If set, use the environment variable GIT_DIR to change the default .git
location of the kernel git tree.

If GIT_DIR is unset, keep using the current ".git" default.

Link: https://lkml.kernel.org/r/c5e23b45562373d632fccb8bc04e563abba4dd1d.camel@perches.comSigned-off-by: Joe Perches <joe@perches.com>
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull timer fixes from Thomas Gleixner:
 "A time namespace fix and a matching selftest. The futex absolute
  timeouts which are based on CLOCK_MONOTONIC require time namespace
  corrected. This was missed in the original time namesapce support"

* tag 'timers-urgent-2020-10-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  selftests/timens: Add a test for futex()
  futex: Adjust absolute futex timeouts with per time namespace offset

Pull scheduler fixes from Thomas Gleixner:
 "Two scheduler fixes:

   - A trivial build fix for sched_feat() to compile correctly with
     CONFIG_JUMP_LABEL=n

   - Replace a zero lenght array with a flexible array"

* tag 'sched-urgent-2020-10-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/features: Fix !CONFIG_JUMP_LABEL case
  sched: Replace zero-length array with flexible-array

Pull perf fix from Thomas Gleixner:
 "A single fix to compute the field offset of the SNOOPX bit in the data
  source bitmask of perf events correctly"

* tag 'perf-urgent-2020-10-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf: correct SNOOPX field offset

Pull locking fix from Thomas Gleixner:
 "Just a trivial fix for kernel-doc warnings"

* tag 'locking-urgent-2020-10-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/seqlocks: Fix kernel-doc warnings

Pull NTB fixes from Jon Mason.

* tag 'ntb-5.10' of git://github.com/jonmason/ntb:
  NTB: Use struct_size() helper in devm_kzalloc()
  ntb: intel: Fix memleak in intel_ntb_pci_probe
  NTB: hw: amd: fix an issue about leak system resources

Pull i2c fix from Wolfram Sang:
 "Regression fix for rc1 and stable kernels as well"

* 'i2c/for-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: core: Restore acpi_walk_dep_device_list() getting called after registering the ACPI i2c devs

Pull more cifs updates from Steve French:
 "Add support for stat of various special file types (WSL reparse points
  for char, block, fifo)"

* tag '5.10-rc-smb3-fixes-part2' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: update internal module version number
  smb3: add some missing definitions from MS-FSCC
  smb3: remove two unused variables
  smb3: add support for stat of WSL reparse points for special file types

Pull more parisc updates from Helge Deller:

 - During this merge window O_NONBLOCK was changed to become 000200000,
   but we missed that the syscalls timerfd_create(), signalfd4(),
   eventfd2(), pipe2(), inotify_init1() and userfaultfd() do a strict
   bit-wise check of the flags parameter.

   To provide backward compatibility with existing userspace we
   introduce parisc specific wrappers for those syscalls which filter
   out the old O_NONBLOCK value and replaces it with the new one.

 - Prevent HIL bus driver to get stuck when keyboard or mouse isn't
   attached

 - Improve error return codes when setting rtc time

 - Minor documentation fix in pata_ns87415.c

* 'parisc-5.10-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  ata: pata_ns87415.c: Document support on parisc with superio chip
  parisc: Add wrapper syscalls to fix O_NONBLOCK flag usage
  hil/parisc: Disable HIL driver when it gets stuck
  parisc: Improve error return codes when setting rtc time

Pull more xen updates from Juergen Gross:

 - a series for the Xen pv block drivers adding module parameters for
   better control of resource usge

 - a cleanup series for the Xen event driver

* tag 'for-linus-5.10b-rc1c-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  Documentation: add xen.fifo_events kernel parameter description
  xen/events: unmask a fifo event channel only if it was masked
  xen/events: only register debug interrupt for 2-level events
  xen/events: make struct irq_info private to events_base.c
  xen: remove no longer used functions
  xen-blkfront: Apply changed parameter name to the document
  xen-blkfront: add a parameter for disabling of persistent grants
  xen-blkback: add a parameter for disabling of persistent grants

Pull SafeSetID updates from Micah Morton:
 "The changes are mostly contained to within the SafeSetID LSM, with the
  exception of a few 1-line changes to change some ns_capable() calls to
  ns_capable_setid() -- causing a flag (CAP_OPT_INSETID) to be set that
  is examined by SafeSetID code and nothing else in the kernel.

  The changes to SafeSetID internally allow for setting up GID
  transition security policies, as already existed for UIDs"

* tag 'safesetid-5.10' of git://github.com/micah-morton/linux:
  LSM: SafeSetID: Fix warnings reported by test bot
  LSM: SafeSetID: Add GID security policy handling
  LSM: Signal to SafeSetID when setting group IDs

Pull random32 updates from Willy Tarreau:
 "Make prandom_u32() less predictable.

  This is the cleanup of the latest series of prandom_u32
  experimentations consisting in using SipHash instead of Tausworthe to
  produce the randoms used by the network stack.

  The changes to the files were kept minimal, and the controversial
  commit that used to take noise from the fast_pool (f227e3ec) was
  reverted. Instead, a dedicated "net_rand_noise" per_cpu variable is
  fed from various sources of activities (networking, scheduling) to
  perturb the SipHash state using fast, non-trivially predictable data,
  instead of keeping it fully deterministic. The goal is essentially to
  make any occasional memory leakage or brute-force attempt useless.

  The resulting code was verified to be very slightly faster on x86_64
  than what is was with the controversial commit above, though this
  remains barely above measurement noise. It was also tested on i386 and
  arm, and build- tested only on arm64"

Link: https://lore.kernel.org/netdev/20200808152628.GA27941@SDF.ORG/

* tag '20201024-v4-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/wtarreau/prandom:
  random32: add a selftest for the prandom32 code
  random32: add noise from network and scheduling activity
  random32: make prandom_u32() output unpredictable

Commit 21653a41 ("i2c: core: Call i2c_acpi_install_space_handler()
before i2c_acpi_register_devices()")'s intention was to only move the
acpi_install_address_space_handler() call to the point before where
the ACPI declared i2c-children of the adapter where instantiated by
i2c_acpi_register_devices().

But i2c_acpi_install_space_handler() had a call to
acpi_walk_dep_device_list() hidden (that is I missed it) at the end
of it, so as an unwanted side-effect now acpi_walk_dep_device_list()
was also being called before i2c_acpi_register_devices().

Move the acpi_walk_dep_device_list() call to the end of
i2c_acpi_register_devices(), so that it is once again called *after*
the i2c_client-s hanging of the adapter have been created.

This fixes the Microsoft Surface Go 2 hanging at boot.

Fixes: 21653a41 ("i2c: core: Call i2c_acpi_install_space_handler() before i2c_acpi_register_devices()")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=209627Reported-by: Rainer Finke <rainer@finke.cc>
Reported-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Suggested-by: Maximilian Luz <luzmaximilian@gmail.com>
Tested-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Pull block fixes from Jens Axboe:

 - NVMe pull request from Christoph
     - rdma error handling fixes (Chao Leng)
     - fc error handling and reconnect fixes (James Smart)
     - fix the qid displace when tracing ioctl command (Keith Busch)
     - don't use BLK_MQ_REQ_NOWAIT for passthru (Chaitanya Kulkarni)
     - fix MTDT for passthru (Logan Gunthorpe)
     - blacklist Write Same on more devices (Kai-Heng Feng)
     - fix an uninitialized work struct (zhenwei pi)"

 - lightnvm out-of-bounds fix (Colin)

 - SG allocation leak fix (Doug)

 - rnbd fixes (Gioh, Guoqing, Jack)

 - zone error translation fixes (Keith)

 - kerneldoc markup fix (Mauro)

 - zram lockdep fix (Peter)

 - Kill unused io_context members (Yufen)

 - NUMA memory allocation cleanup (Xianting)

 - NBD config wakeup fix (Xiubo)

* tag 'block-5.10-2020-10-24' of git://git.kernel.dk/linux-block: (27 commits)
  block: blk-mq: fix a kernel-doc markup
  nvme-fc: shorten reconnect delay if possible for FC
  nvme-fc: wait for queues to freeze before calling update_hr_hw_queues
  nvme-fc: fix error loop in create_hw_io_queues
  nvme-fc: fix io timeout to abort I/O
  null_blk: use zone status for max active/open
  nvmet: don't use BLK_MQ_REQ_NOWAIT for passthru
  nvmet: cleanup nvmet_passthru_map_sg()
  nvmet: limit passthru MTDS by BIO_MAX_PAGES
  nvmet: fix uninitialized work for zero kato
  nvme-pci: disable Write Zeroes on Sandisk Skyhawk
  nvme: use queuedata for nvme_req_qid
  nvme-rdma: fix crash due to incorrect cqe
  nvme-rdma: fix crash when connect rejected
  block: remove unused members for io_context
  blk-mq: remove the calling of local_memory_node()
  zram: Fix __zram_bvec_{read,write}() locking order
  skd_main: remove unused including <linux/version.h>
  sgl_alloc_order: fix memory leak
  lightnvm: fix out-of-bounds write to array devices->info[]
  ...

Pull io_uring fixes from Jens Axboe:

 - fsize was missed in previous unification of work flags

 - Few fixes cleaning up the flags unification creds cases (Pavel)

 - Fix NUMA affinities for completely unplugged/replugged node for io-wq

 - Two fallout fixes from the set_fs changes. One local to io_uring, one
   for the splice entry point that io_uring uses.

 - Linked timeout fixes (Pavel)

 - Removal of ->flush() ->files work-around that we don't need anymore
   with referenced files (Pavel)

 - Various cleanups (Pavel)

* tag 'io_uring-5.10-2020-10-24' of git://git.kernel.dk/linux-block:
  splice: change exported internal do_splice() helper to take kernel offset
  io_uring: make loop_rw_iter() use original user supplied pointers
  io_uring: remove req cancel in ->flush()
  io-wq: re-set NUMA node affinities if CPUs come online
  io_uring: don't reuse linked_timeout
  io_uring: unify fsize with def->work_flags
  io_uring: fix racy REQ_F_LINK_TIMEOUT clearing
  io_uring: do poll's hash_node init in common code
  io_uring: inline io_poll_task_handler()
  io_uring: remove extra ->file check in poll prep
  io_uring: make cached_cq_overflow non atomic_t
  io_uring: inline io_fail_links()
  io_uring: kill ref get/drop in personality init
  io_uring: flags-based creds init in queue

Pull libata fixes from Jens Axboe:
 "Two minor libata fixes:

   - Fix a DMA boundary mask regression for sata_rcar (Geert)

   - kerneldoc markup fix (Mauro)"

* tag 'libata-5.10-2020-10-24' of git://git.kernel.dk/linux-block:
  ata: fix some kernel-doc markups
  ata: sata_rcar: Fix DMA boundary mask

Pull misc vfs updates from Al Viro:
 "Assorted stuff all over the place (the largest group here is
  Christoph's stat cleanups)"

* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fs: remove KSTAT_QUERY_FLAGS
  fs: remove vfs_stat_set_lookup_flags
  fs: move vfs_fstatat out of line
  fs: implement vfs_stat and vfs_lstat in terms of vfs_fstatat
  fs: remove vfs_statx_fd
  fs: omfs: use kmemdup() rather than kmalloc+memcpy
  [PATCH] reduce boilerplate in fsid handling
  fs: Remove duplicated flag O_NDELAY occurring twice in VALID_OPEN_FLAGS
  selftests: mount: add nosymfollow tests
  Add a "nosymfollow" mount option.

Pull dma-mapping fixes from Christoph Hellwig:

 - document the new dma_{alloc,free}_pages() API

 - two fixups for the dma-mapping.h split

* tag 'dma-mapping-5.10-1' of git://git.infradead.org/users/hch/dma-mapping:
  dma-mapping: document dma_{alloc,free}_pages
  dma-mapping: move more functions to dma-map-ops.h
  ARM/sa1111: add a missing include of dma-map-ops.h

Pull KVM fixes from Paolo Bonzini:
 "Two fixes for this merge window, and an unrelated bugfix for a host
  hang"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: ioapic: break infinite recursion on lazy EOI
  KVM: vmx: rename pi_init to avoid conflict with paride
  KVM: x86/mmu: Avoid modulo operator on 64-bit value to fix i386 build

Pull x86 SEV-ES fixes from Borislav Petkov:
 "Three fixes to SEV-ES to correct setting up the new early pagetable on
  5-level paging machines, to always map boot_params and the kernel
  cmdline, and disable stack protector for ../compressed/head{32,64}.c.
  (Arvind Sankar)"

* tag 'x86_seves_fixes_for_v5.10_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/boot/64: Explicitly map boot_params and command line
  x86/head/64: Disable stack protection for head$(BITS).o
  x86/boot/64: Initialize 5-level paging variables earlier

Given that this code is new, let's add a selftest for it as well.
It doesn't rely on fixed sets, instead it picks 1024 numbers and
verifies that they're not more correlated than desired.

Link: https://lore.kernel.org/netdev/20200808152628.GA27941@SDF.ORG/
Cc: George Spelvin <lkml@sdf.org>
Cc: Amit Klein <aksecurity@gmail.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: tytso@mit.edu
Cc: Florian Westphal <fw@strlen.de>
Cc: Marc Plumb <lkml.mplumb@gmail.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>

With the removal of the interrupt perturbations in previous random32
change (random32: make prandom_u32() output unpredictable), the PRNG
has become 100% deterministic again. While SipHash is expected to be
way more robust against brute force than the previous Tausworthe LFSR,
there's still the risk that whoever has even one temporary access to
the PRNG's internal state is able to predict all subsequent draws till
the next reseed (roughly every minute). This may happen through a side
channel attack or any data leak.

This patch restores the spirit of commit f227e3ec ("random32: update
the net random state on interrupt and activity") in that it will perturb
the internal PRNG's statee using externally collected noise, except that
it will not pick that noise from the random pool's bits nor upon
interrupt, but will rather combine a few elements along the Tx path
that are collectively hard to predict, such as dev, skb and txq
pointers, packet length and jiffies values. These ones are combined
using a single round of SipHash into a single long variable that is
mixed with the net_rand_state upon each invocation.

The operation was inlined because it produces very small and efficient
code, typically 3 xor, 2 add and 2 rol. The performance was measured
to be the same (even very slightly better) than before the switch to
SipHash; on a 6-core 12-thread Core i7-8700k equipped with a 40G NIC
(i40e), the connection rate dropped from 556k/s to 555k/s while the
SYN cookie rate grew from 5.38 Mpps to 5.45 Mpps.

Link: https://lore.kernel.org/netdev/20200808152628.GA27941@SDF.ORG/
Cc: George Spelvin <lkml@sdf.org>
Cc: Amit Klein <aksecurity@gmail.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: tytso@mit.edu
Cc: Florian Westphal <fw@strlen.de>
Cc: Marc Plumb <lkml.mplumb@gmail.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>

Non-cryptographic PRNGs may have great statistical properties, but
are usually trivially predictable to someone who knows the algorithm,
given a small sample of their output.  An LFSR like prandom_u32() is
particularly simple, even if the sample is widely scattered bits.

It turns out the network stack uses prandom_u32() for some things like
random port numbers which it would prefer are *not* trivially predictable.
Predictability led to a practical DNS spoofing attack.  Oops.

This patch replaces the LFSR with a homebrew cryptographic PRNG based
on the SipHash round function, which is in turn seeded with 128 bits
of strong random key.  (The authors of SipHash have *not* been consulted
about this abuse of their algorithm.)  Speed is prioritized over security;
attacks are rare, while performance is always wanted.

Replacing all callers of prandom_u32() is the quick fix.
Whether to reinstate a weaker PRNG for uses which can tolerate it
is an open question.

Commit f227e3ec ("random32: update the net random state on interrupt
and activity") was an earlier attempt at a solution.  This patch replaces
it.
Reported-by: Amit Klein <aksecurity@gmail.com>
Cc: Willy Tarreau <w@1wt.eu>
Cc: Eric Dumazet <edumazet@google.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: tytso@mit.edu
Cc: Florian Westphal <fw@strlen.de>
Cc: Marc Plumb <lkml.mplumb@gmail.com>
Fixes: f227e3ec ("random32: update the net random state on interrupt and activity")
Signed-off-by: George Spelvin <lkml@sdf.org>
Link: https://lore.kernel.org/netdev/20200808152628.GA27941@SDF.ORG/
[ willy: partial reversal of f227e3ec; moved SIPROUND definitions
  to prandom.h for later use; merged George's prandom_seed() proposal;
  inlined siprand_u32(); replaced the net_rand_state[] array with 4
  members to fix a build issue; cosmetic cleanups to make checkpatch
  happy; fixed RANDOM32_SELFTEST build ]
Signed-off-by: Willy Tarreau <w@1wt.eu>

Pull powerpc fixes from Michael Ellerman:

 - A fix for undetected data corruption on Power9 Nimbus <= DD2.1 in the
   emulation of VSX loads. The affected CPUs were not widely available.

 - Two fixes for machine check handling in guests under PowerVM.

 - A fix for our recent changes to SMP setup, when
   CONFIG_CPUMASK_OFFSTACK=y.

 - Three fixes for races in the handling of some of our powernv sysfs
   attributes.

 - One change to remove TM from the set of Power10 CPU features.

 - A couple of other minor fixes.

Thanks to: Aneesh Kumar K.V, Christophe Leroy, Ganesh Goudar, Jordan
Niethe, Mahesh Salgaonkar, Michael Neuling, Oliver O'Halloran, Qian Cai,
Srikar Dronamraju, Vasant Hegde.

* tag 'powerpc-5.10-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/pseries: Avoid using addr_to_pfn in real mode
  powerpc/uaccess: Don't use "m<>" constraint with GCC 4.9
  powerpc/eeh: Fix eeh_dev_check_failure() for PE#0
  powerpc/64s: Remove TM from Power10 features
  selftests/powerpc: Make alignment handler test P9N DD2.1 vector CI load workaround
  powerpc: Fix undetected data corruption with P9N DD2.1 VSX CI load emulation
  powerpc/powernv/dump: Handle multiple writes to ack attribute
  powerpc/powernv/dump: Fix race while processing OPAL dump
  powerpc/smp: Use GFP_ATOMIC while allocating tmp mask
  powerpc/smp: Remove unnecessary variable
  powerpc/mce: Avoid nmi_enter/exit in real mode on pseries hash
  powerpc/opal_elog: Handle multiple writes to ack attribute

Pull more RISC-V updates from Palmer Dabbelt:
 "Just a single patch set: the remainder of Christoph's work to remove
  set_fs, including the RISC-V portion"

* tag 'riscv-for-linus-5.10-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  riscv: remove address space overrides using set_fs()
  riscv: implement __get_kernel_nofault and __put_user_nofault
  riscv: refactor __get_user and __put_user
  riscv: use memcpy based uaccess for nommu again
  asm-generic: make the set_fs implementation optional
  asm-generic: add nommu implementations of __{get,put}_kernel_nofault
  asm-generic: improve the nommu {get,put}_user handling
  uaccess: provide a generic TASK_SIZE_MAX definition

Pull ARM SoC defconfig updates from Olof Johansson:
 "We keep this in a separate branch to avoid cross-branch conflicts, but
  most of the material here is fairly boring -- some new drivers turned
  on for hardware since they were merged, and some refreshed files due
  to time having moved a lot of entries around"

* tag 'armsoc-defconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (33 commits)
  ARM: multi_v7_defconfig: add FMC2 EBI controller support
  arm64: defconfig: enable Qualcomm ASoC modules
  arm64: defconfig: qcom: enable GPU clock controller for SM8[12]50
  arm64: defconfig: enable INTERCONNECT for Qualcomm chipsets
  arm64: defconfig: enable the sl28cpld board management controller
  arm64: defconfig: Enable the eLCDIF and Raydium RM67191 drivers
  arm64: defconfig: Enable Qcom SNPS Femto PHY
  ARM: configs: Update Realview defconfig
  ARM: configs: Update Versatile defconfig
  ARM: config: aspeed_g5: Enable IBM OP Panel driver
  ARM: config: aspeed-g5: Enable I2C GPIO mux driver
  ARM: config: aspeed: Fix selection of media drivers
  arm64: defconfig: Enable Samsung S3FWRN5 NFC driver
  ARM: omap2plus_defconfig: enable generic net options
  ARM: omap2plus_defconfig: enable twl4030_madc as a loadable module
  arm64: defconfig: Enable clock driver for ROHM BD718x7 PMIC
  arm64: defconfig: Build ADMA and ACONNECT driver
  arm64: defconfig: Build AHUB component drivers
  arm64: defconfig: Enable Lontium LT9611 driver
  arm64: defcondfig: Enable USB ACM and FTDI drivers
  ...