linux.git/arch/hexagon, branch v5.12 Linux kernel source tree Merge tag 'io_uring-worker.v3-2021-02-25' of git://git.kernel.dk/linux-block 2021-02-27T16:29:02+00:00 Linus Torvalds torvalds@linux-foundation.org 2021-02-27T16:29:02+00:00 5695e51619745d4fe3ec2506a2f0cd982c5e27a4 Pull io_uring thread rewrite from Jens Axboe: "This converts the io-wq workers to be forked off the tasks in question instead of being kernel threads that assume various bits of the original task identity. This kills > 400 lines of code from io_uring/io-wq, and it's the worst part of the code. We've had several bugs in this area, and the worry is always that we could be missing some pieces for file types doing unusual things (recent /dev/tty example comes to mind, userfaultfd reads installing file descriptors is another fun one... - both of which need special handling, and I bet it's not the last weird oddity we'll find). With these identical workers, we can have full confidence that we're never missing anything. That, in itself, is a huge win. Outside of that, it's also more efficient since we're not wasting space and code on tracking state, or switching between different states. I'm sure we're going to find little things to patch up after this series, but testing has been pretty thorough, from the usual regression suite to production. Any issue that may crop up should be manageable. There's also a nice series of further reductions we can do on top of this, but I wanted to get the meat of it out sooner rather than later. The general worry here isn't that it's fundamentally broken. Most of the little issues we've found over the last week have been related to just changes in how thread startup/exit is done, since that's the main difference between using kthreads and these kinds of threads. In fact, if all goes according to plan, I want to get this into the 5.10 and 5.11 stable branches as well. That said, the changes outside of io_uring/io-wq are: - arch setup, simple one-liner to each arch copy_thread() implementation. - Removal of net and proc restrictions for io_uring, they are no longer needed or useful" * tag 'io_uring-worker.v3-2021-02-25' of git://git.kernel.dk/linux-block: (30 commits) io-wq: remove now unused IO_WQ_BIT_ERROR io_uring: fix SQPOLL thread handling over exec io-wq: improve manager/worker handling over exec io_uring: ensure SQPOLL startup is triggered before error shutdown io-wq: make buffered file write hashed work map per-ctx io-wq: fix race around io_worker grabbing io-wq: fix races around manager/worker creation and task exit io_uring: ensure io-wq context is always destroyed for tasks arch: ensure parisc/powerpc handle PF_IO_WORKER in copy_thread() io_uring: cleanup ->user usage io-wq: remove nr_process accounting io_uring: flag new native workers with IORING_FEAT_NATIVE_WORKERS net: remove cmsg restriction from io_uring based send/recvmsg calls Revert "proc: don't allow async path resolution of /proc/self components" Revert "proc: don't allow async path resolution of /proc/thread-self components" io_uring: move SQPOLL thread io-wq forked worker io-wq: make io_wq_fork_thread() available to other users io-wq: only remove worker from free_list, if it was there io_uring: remove io_identity io_uring: remove any grabbing of context ... 
Pull io_uring thread rewrite from Jens Axboe:
 "This converts the io-wq workers to be forked off the tasks in question
  instead of being kernel threads that assume various bits of the
  original task identity.

  This kills > 400 lines of code from io_uring/io-wq, and it's the worst
  part of the code. We've had several bugs in this area, and the worry
  is always that we could be missing some pieces for file types doing
  unusual things (recent /dev/tty example comes to mind, userfaultfd
  reads installing file descriptors is another fun one... - both of
  which need special handling, and I bet it's not the last weird oddity
  we'll find).

  With these identical workers, we can have full confidence that we're
  never missing anything. That, in itself, is a huge win. Outside of
  that, it's also more efficient since we're not wasting space and code
  on tracking state, or switching between different states.

  I'm sure we're going to find little things to patch up after this
  series, but testing has been pretty thorough, from the usual
  regression suite to production. Any issue that may crop up should be
  manageable.

  There's also a nice series of further reductions we can do on top of
  this, but I wanted to get the meat of it out sooner rather than later.
  The general worry here isn't that it's fundamentally broken. Most of
  the little issues we've found over the last week have been related to
  just changes in how thread startup/exit is done, since that's the main
  difference between using kthreads and these kinds of threads. In fact,
  if all goes according to plan, I want to get this into the 5.10 and
  5.11 stable branches as well.

  That said, the changes outside of io_uring/io-wq are:

   - arch setup, simple one-liner to each arch copy_thread()
     implementation.

   - Removal of net and proc restrictions for io_uring, they are no
     longer needed or useful"

* tag 'io_uring-worker.v3-2021-02-25' of git://git.kernel.dk/linux-block: (30 commits)
  io-wq: remove now unused IO_WQ_BIT_ERROR
  io_uring: fix SQPOLL thread handling over exec
  io-wq: improve manager/worker handling over exec
  io_uring: ensure SQPOLL startup is triggered before error shutdown
  io-wq: make buffered file write hashed work map per-ctx
  io-wq: fix race around io_worker grabbing
  io-wq: fix races around manager/worker creation and task exit
  io_uring: ensure io-wq context is always destroyed for tasks
  arch: ensure parisc/powerpc handle PF_IO_WORKER in copy_thread()
  io_uring: cleanup ->user usage
  io-wq: remove nr_process accounting
  io_uring: flag new native workers with IORING_FEAT_NATIVE_WORKERS
  net: remove cmsg restriction from io_uring based send/recvmsg calls
  Revert "proc: don't allow async path resolution of /proc/self components"
  Revert "proc: don't allow async path resolution of /proc/thread-self components"
  io_uring: move SQPOLL thread io-wq forked worker
  io-wq: make io_wq_fork_thread() available to other users
  io-wq: only remove worker from free_list, if it was there
  io_uring: remove io_identity
  io_uring: remove any grabbing of context
  ...
hexagon: remove CONFIG_EXPERIMENTAL from defconfigs 2021-02-24T21:38:26+00:00 Randy Dunlap rdunlap@infradead.org 2021-02-24T20:00:12+00:00 c79c3c34f75d72a066e292b10aa50fc758c97c89 Since CONFIG_EXPERIMENTAL was removed in 2013, go ahead and drop it from any defconfig files. Link: https://lkml.kernel.org/r/20210115010011.29483-1-rdunlap@infradead.org Fixes: 3d374d09f16f ("final removal of CONFIG_EXPERIMENTAL") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Kees Cook <keescook@chromium.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Brian Cain <bcain@codeaurora.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
Since CONFIG_EXPERIMENTAL was removed in 2013, go ahead and drop it
from any defconfig files.

Link: https://lkml.kernel.org/r/20210115010011.29483-1-rdunlap@infradead.org
Fixes: 3d374d09f16f ("final removal of CONFIG_EXPERIMENTAL")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Brian Cain <bcain@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
arch: setup PF_IO_WORKER threads like PF_KTHREAD 2021-02-22T00:25:22+00:00 Jens Axboe axboe@kernel.dk 2021-02-17T15:48:00+00:00 4727dc20e0422211a0e0c72b1ace4ed6096df8a6 PF_IO_WORKER are kernel threads too, but they aren't PF_KTHREAD in the sense that we don't assign ->set_child_tid with our own structure. Just ensure that every arch sets up the PF_IO_WORKER threads like kthreads in the arch implementation of copy_thread(). Signed-off-by: Jens Axboe <axboe@kernel.dk> 
PF_IO_WORKER are kernel threads too, but they aren't PF_KTHREAD in the
sense that we don't assign ->set_child_tid with our own structure. Just
ensure that every arch sets up the PF_IO_WORKER threads like kthreads
in the arch implementation of copy_thread().

Signed-off-by: Jens Axboe <axboe@kernel.dk>
arch: hexagon: Don't select HAVE_OPROFILE 2021-01-22T06:42:08+00:00 Viresh Kumar viresh.kumar@linaro.org 2021-01-14T11:35:17+00:00 ccbcf16174e15ca6be28e04a3248d61a59d23072 The "oprofile" user-space tools don't use the kernel OPROFILE support any more, and haven't in a long time. User-space has been converted to the perf interfaces. Don't select HAVE_OPROFILE for hexagon anymore. Suggested-by: Christoph Hellwig <hch@infradead.org> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Robert Richter <rric@kernel.org> Acked-by: Brian Cain <bcain@codeaurora.org> Acked-by: William Cohen <wcohen@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Acked-by: Thomas Gleixner <tglx@linutronix.de> 
The "oprofile" user-space tools don't use the kernel OPROFILE support
any more, and haven't in a long time. User-space has been converted to
the perf interfaces.

Don't select HAVE_OPROFILE for hexagon anymore.

Suggested-by: Christoph Hellwig <hch@infradead.org>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Robert Richter <rric@kernel.org>
Acked-by: Brian Cain <bcain@codeaurora.org>
Acked-by: William Cohen <wcohen@redhat.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
local64.h: make <asm/local64.h> mandatory 2020-12-29T23:36:49+00:00 Randy Dunlap rdunlap@infradead.org 2020-12-29T23:14:49+00:00 87dbc209ea04645fd2351981f09eff5d23f8e2e9 Make <asm-generic/local64.h> mandatory in include/asm-generic/Kbuild and remove all arch/*/include/asm/local64.h arch-specific files since they only #include <asm-generic/local64.h>. This fixes build errors on arch/c6x/ and arch/nios2/ for block/blk-iocost.c. Build-tested on 21 of 25 arch-es. (tools problems on the others) Yes, we could even rename <asm-generic/local64.h> to <linux/local64.h> and change all #includes to use <linux/local64.h> instead. Link: https://lkml.kernel.org/r/20201227024446.17018-1-rdunlap@infradead.org Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Suggested-by: Christoph Hellwig <hch@infradead.org> Reviewed-by: Masahiro Yamada <masahiroy@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Ley Foon Tan <ley.foon.tan@intel.com> Cc: Mark Salter <msalter@redhat.com> Cc: Aurelien Jacquiot <jacquiot.aurelien@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
Make <asm-generic/local64.h> mandatory in include/asm-generic/Kbuild and
remove all arch/*/include/asm/local64.h arch-specific files since they
only #include <asm-generic/local64.h>.

This fixes build errors on arch/c6x/ and arch/nios2/ for
block/blk-iocost.c.

Build-tested on 21 of 25 arch-es.  (tools problems on the others)

Yes, we could even rename <asm-generic/local64.h> to
<linux/local64.h> and change all #includes to use
<linux/local64.h> instead.

Link: https://lkml.kernel.org/r/20201227024446.17018-1-rdunlap@infradead.org
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Suggested-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Masahiro Yamada <masahiroy@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Aurelien Jacquiot <jacquiot.aurelien@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge tag 'tif-task_work.arch-2020-12-14' of git://git.kernel.dk/linux-block 2020-12-16T20:33:35+00:00 Linus Torvalds torvalds@linux-foundation.org 2020-12-16T20:33:35+00:00 005b2a9dc819a1265a8c765595f8f6d88d6173d9 Pull TIF_NOTIFY_SIGNAL updates from Jens Axboe: "This sits on top of of the core entry/exit and x86 entry branch from the tip tree, which contains the generic and x86 parts of this work. Here we convert the rest of the archs to support TIF_NOTIFY_SIGNAL. With that done, we can get rid of JOBCTL_TASK_WORK from task_work and signal.c, and also remove a deadlock work-around in io_uring around knowing that signal based task_work waking is invoked with the sighand wait queue head lock. The motivation for this work is to decouple signal notify based task_work, of which io_uring is a heavy user of, from sighand. The sighand lock becomes a huge contention point, particularly for threaded workloads where it's shared between threads. Even outside of threaded applications it's slower than it needs to be. Roman Gershman <romger@amazon.com> reported that his networked workload dropped from 1.6M QPS at 80% CPU to 1.0M QPS at 100% CPU after io_uring was changed to use TIF_NOTIFY_SIGNAL. The time was all spent hammering on the sighand lock, showing 57% of the CPU time there [1]. There are further cleanups possible on top of this. One example is TIF_PATCH_PENDING, where a patch already exists to use TIF_NOTIFY_SIGNAL instead. Hopefully this will also lead to more consolidation, but the work stands on its own as well" [1] https://github.com/axboe/liburing/issues/215 * tag 'tif-task_work.arch-2020-12-14' of git://git.kernel.dk/linux-block: (28 commits) io_uring: remove 'twa_signal_ok' deadlock work-around kernel: remove checking for TIF_NOTIFY_SIGNAL signal: kill JOBCTL_TASK_WORK io_uring: JOBCTL_TASK_WORK is no longer used by task_work task_work: remove legacy TWA_SIGNAL path sparc: add support for TIF_NOTIFY_SIGNAL riscv: add support for TIF_NOTIFY_SIGNAL nds32: add support for TIF_NOTIFY_SIGNAL ia64: add support for TIF_NOTIFY_SIGNAL h8300: add support for TIF_NOTIFY_SIGNAL c6x: add support for TIF_NOTIFY_SIGNAL alpha: add support for TIF_NOTIFY_SIGNAL xtensa: add support for TIF_NOTIFY_SIGNAL arm: add support for TIF_NOTIFY_SIGNAL microblaze: add support for TIF_NOTIFY_SIGNAL hexagon: add support for TIF_NOTIFY_SIGNAL csky: add support for TIF_NOTIFY_SIGNAL openrisc: add support for TIF_NOTIFY_SIGNAL sh: add support for TIF_NOTIFY_SIGNAL um: add support for TIF_NOTIFY_SIGNAL ... 
Pull TIF_NOTIFY_SIGNAL updates from Jens Axboe:
 "This sits on top of of the core entry/exit and x86 entry branch from
  the tip tree, which contains the generic and x86 parts of this work.

  Here we convert the rest of the archs to support TIF_NOTIFY_SIGNAL.

  With that done, we can get rid of JOBCTL_TASK_WORK from task_work and
  signal.c, and also remove a deadlock work-around in io_uring around
  knowing that signal based task_work waking is invoked with the sighand
  wait queue head lock.

  The motivation for this work is to decouple signal notify based
  task_work, of which io_uring is a heavy user of, from sighand. The
  sighand lock becomes a huge contention point, particularly for
  threaded workloads where it's shared between threads. Even outside of
  threaded applications it's slower than it needs to be.

  Roman Gershman <romger@amazon.com> reported that his networked
  workload dropped from 1.6M QPS at 80% CPU to 1.0M QPS at 100% CPU
  after io_uring was changed to use TIF_NOTIFY_SIGNAL. The time was all
  spent hammering on the sighand lock, showing 57% of the CPU time there
  [1].

  There are further cleanups possible on top of this. One example is
  TIF_PATCH_PENDING, where a patch already exists to use
  TIF_NOTIFY_SIGNAL instead. Hopefully this will also lead to more
  consolidation, but the work stands on its own as well"

[1] https://github.com/axboe/liburing/issues/215

* tag 'tif-task_work.arch-2020-12-14' of git://git.kernel.dk/linux-block: (28 commits)
  io_uring: remove 'twa_signal_ok' deadlock work-around
  kernel: remove checking for TIF_NOTIFY_SIGNAL
  signal: kill JOBCTL_TASK_WORK
  io_uring: JOBCTL_TASK_WORK is no longer used by task_work
  task_work: remove legacy TWA_SIGNAL path
  sparc: add support for TIF_NOTIFY_SIGNAL
  riscv: add support for TIF_NOTIFY_SIGNAL
  nds32: add support for TIF_NOTIFY_SIGNAL
  ia64: add support for TIF_NOTIFY_SIGNAL
  h8300: add support for TIF_NOTIFY_SIGNAL
  c6x: add support for TIF_NOTIFY_SIGNAL
  alpha: add support for TIF_NOTIFY_SIGNAL
  xtensa: add support for TIF_NOTIFY_SIGNAL
  arm: add support for TIF_NOTIFY_SIGNAL
  microblaze: add support for TIF_NOTIFY_SIGNAL
  hexagon: add support for TIF_NOTIFY_SIGNAL
  csky: add support for TIF_NOTIFY_SIGNAL
  openrisc: add support for TIF_NOTIFY_SIGNAL
  sh: add support for TIF_NOTIFY_SIGNAL
  um: add support for TIF_NOTIFY_SIGNAL
  ...
Merge tag 'asm-generic-timers-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic 2020-12-16T08:07:17+00:00 Linus Torvalds torvalds@linux-foundation.org 2020-12-16T08:07:17+00:00 7a932e5702886e872a545d64605c06a51ee17973 Pull asm-generic cross-architecture timer cleanup from Arnd Bergmann: "This cleans up two ancient timer features that were never completed in the past, CONFIG_GENERIC_CLOCKEVENTS and CONFIG_ARCH_USES_GETTIMEOFFSET. There was only one user left for the ARCH_USES_GETTIMEOFFSET variant of clocksource implementations, the ARM EBSA110 platform. Rather than changing to use modern timekeeping, we remove the platform entirely as Russell no longer uses his machine and nobody else seems to have one any more. The conditional code for using arch_gettimeoffset() is removed as a result. For CONFIG_GENERIC_CLOCKEVENTS, there are still a couple of platforms not using clockevent drivers: parisc, ia64, most of m68k, and one Arm platform. These all do timer ticks slighly differently, and this gets cleaned up to the point they at least all call the same helper function. Instead of most platforms using 'select GENERIC_CLOCKEVENTS' in Kconfig, the polarity is now reversed, with the few remaining ones selecting LEGACY_TIMER_TICK instead" * tag 'asm-generic-timers-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: timekeeping: default GENERIC_CLOCKEVENTS to enabled timekeeping: remove xtime_update m68k: remove timer_interrupt() function m68k: change remaining timers to legacy_timer_tick m68k: m68328: use legacy_timer_tick() m68k: sun3/sun3c: use legacy_timer_tick m68k: split heartbeat out of timer function m68k: coldfire: use legacy_timer_tick() parisc: use legacy_timer_tick ARM: rpc: use legacy_timer_tick ia64: convert to legacy_timer_tick timekeeping: add CONFIG_LEGACY_TIMER_TICK timekeeping: remove arch_gettimeoffset net: remove am79c961a driver ARM: remove ebsa110 platform 
Pull asm-generic cross-architecture timer cleanup from Arnd Bergmann:
 "This cleans up two ancient timer features that were never completed in
  the past, CONFIG_GENERIC_CLOCKEVENTS and CONFIG_ARCH_USES_GETTIMEOFFSET.

  There was only one user left for the ARCH_USES_GETTIMEOFFSET variant
  of clocksource implementations, the ARM EBSA110 platform. Rather than
  changing to use modern timekeeping, we remove the platform entirely as
  Russell no longer uses his machine and nobody else seems to have one
  any more.

  The conditional code for using arch_gettimeoffset() is removed as a
  result.

  For CONFIG_GENERIC_CLOCKEVENTS, there are still a couple of platforms
  not using clockevent drivers: parisc, ia64, most of m68k, and one Arm
  platform. These all do timer ticks slighly differently, and this gets
  cleaned up to the point they at least all call the same helper
  function.

  Instead of most platforms using 'select GENERIC_CLOCKEVENTS' in
  Kconfig, the polarity is now reversed, with the few remaining ones
  selecting LEGACY_TIMER_TICK instead"

* tag 'asm-generic-timers-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
  timekeeping: default GENERIC_CLOCKEVENTS to enabled
  timekeeping: remove xtime_update
  m68k: remove timer_interrupt() function
  m68k: change remaining timers to legacy_timer_tick
  m68k: m68328: use legacy_timer_tick()
  m68k: sun3/sun3c: use legacy_timer_tick
  m68k: split heartbeat out of timer function
  m68k: coldfire: use legacy_timer_tick()
  parisc: use legacy_timer_tick
  ARM: rpc: use legacy_timer_tick
  ia64: convert to legacy_timer_tick
  timekeeping: add CONFIG_LEGACY_TIMER_TICK
  timekeeping: remove arch_gettimeoffset
  net: remove am79c961a driver
  ARM: remove ebsa110 platform
Merge tag 'asm-generic-mmu-context-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic 2020-12-16T07:58:04+00:00 Linus Torvalds torvalds@linux-foundation.org 2020-12-16T07:58:04+00:00 157807123c94acc8dcddd08a2335bd0173c5d68d Pull asm-generic mmu-context cleanup from Arnd Bergmann: "This is a cleanup series from Nicholas Piggin, preparing for later changes. The asm/mmu_context.h header are generalized and common code moved to asm-gneneric/mmu_context.h. This saves a bit of code and makes it easier to change in the future" * tag 'asm-generic-mmu-context-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: (25 commits) h8300: Fix generic mmu_context build m68k: mmu_context: Fix Sun-3 build xtensa: use asm-generic/mmu_context.h for no-op implementations x86: use asm-generic/mmu_context.h for no-op implementations um: use asm-generic/mmu_context.h for no-op implementations sparc: use asm-generic/mmu_context.h for no-op implementations sh: use asm-generic/mmu_context.h for no-op implementations s390: use asm-generic/mmu_context.h for no-op implementations riscv: use asm-generic/mmu_context.h for no-op implementations powerpc: use asm-generic/mmu_context.h for no-op implementations parisc: use asm-generic/mmu_context.h for no-op implementations openrisc: use asm-generic/mmu_context.h for no-op implementations nios2: use asm-generic/mmu_context.h for no-op implementations nds32: use asm-generic/mmu_context.h for no-op implementations mips: use asm-generic/mmu_context.h for no-op implementations microblaze: use asm-generic/mmu_context.h for no-op implementations m68k: use asm-generic/mmu_context.h for no-op implementations ia64: use asm-generic/mmu_context.h for no-op implementations hexagon: use asm-generic/mmu_context.h for no-op implementations csky: use asm-generic/mmu_context.h for no-op implementations ... 
Pull asm-generic mmu-context cleanup from Arnd Bergmann:
 "This is a cleanup series from Nicholas Piggin, preparing for later
  changes. The asm/mmu_context.h header are generalized and common code
  moved to asm-gneneric/mmu_context.h.

  This saves a bit of code and makes it easier to change in the future"

* tag 'asm-generic-mmu-context-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: (25 commits)
  h8300: Fix generic mmu_context build
  m68k: mmu_context: Fix Sun-3 build
  xtensa: use asm-generic/mmu_context.h for no-op implementations
  x86: use asm-generic/mmu_context.h for no-op implementations
  um: use asm-generic/mmu_context.h for no-op implementations
  sparc: use asm-generic/mmu_context.h for no-op implementations
  sh: use asm-generic/mmu_context.h for no-op implementations
  s390: use asm-generic/mmu_context.h for no-op implementations
  riscv: use asm-generic/mmu_context.h for no-op implementations
  powerpc: use asm-generic/mmu_context.h for no-op implementations
  parisc: use asm-generic/mmu_context.h for no-op implementations
  openrisc: use asm-generic/mmu_context.h for no-op implementations
  nios2: use asm-generic/mmu_context.h for no-op implementations
  nds32: use asm-generic/mmu_context.h for no-op implementations
  mips: use asm-generic/mmu_context.h for no-op implementations
  microblaze: use asm-generic/mmu_context.h for no-op implementations
  m68k: use asm-generic/mmu_context.h for no-op implementations
  ia64: use asm-generic/mmu_context.h for no-op implementations
  hexagon: use asm-generic/mmu_context.h for no-op implementations
  csky: use asm-generic/mmu_context.h for no-op implementations
  ...
Merge branch 'regset.followup' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-12-16T03:09:44+00:00 Linus Torvalds torvalds@linux-foundation.org 2020-12-16T03:09:44+00:00 37373d9c37a3401c08f22b61de1726b4f584b2e7 Pull regset updates from Al Viro: "Dead code removal, mostly. The only exception is a bit of cleanups on itanic (getting rid of redundant stack unwinds - each access_uarea() call does it and we call that 7 times in a row in ptrace_[sg]etregs(), *after* having done it ourselves in the caller; location where the user registers have been spilled won't change under us, and we can bloody well just call access_elf_reg() directly, giving it the unw_frame_info we'd calculated for our own purposes)" * 'regset.followup' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: c6x: kill ELF_CORE_COPY_FPREGS whack-a-mole: USE_ELF_CORE_DUMP [ia64] ptrace_[sg]etregs(): use access_elf_reg() instead of access_uarea() [ia64] missed cleanups from switch to regset coredumps arm: kill dump_task_regs() 
Pull regset updates from Al Viro:
 "Dead code removal, mostly.

  The only exception is a bit of cleanups on itanic (getting rid of
  redundant stack unwinds - each access_uarea() call does it and we call
  that 7 times in a row in ptrace_[sg]etregs(), *after* having done it
  ourselves in the caller; location where the user registers have been
  spilled won't change under us, and we can bloody well just call
  access_elf_reg() directly, giving it the unw_frame_info we'd
  calculated for our own purposes)"

* 'regset.followup' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  c6x: kill ELF_CORE_COPY_FPREGS
  whack-a-mole: USE_ELF_CORE_DUMP
  [ia64] ptrace_[sg]etregs(): use access_elf_reg() instead of access_uarea()
  [ia64] missed cleanups from switch to regset coredumps
  arm: kill dump_task_regs()
sched/idle: Fix arch_cpu_idle() vs tracing 2020-11-24T15:47:35+00:00 Peter Zijlstra peterz@infradead.org 2020-11-20T10:50:35+00:00 58c644ba512cfbc2e39b758dd979edd1d6d00e27 We call arch_cpu_idle() with RCU disabled, but then use local_irq_{en,dis}able(), which invokes tracing, which relies on RCU. Switch all arch_cpu_idle() implementations to use raw_local_irq_{en,dis}able() and carefully manage the lockdep,rcu,tracing state like we do in entry. (XXX: we really should change arch_cpu_idle() to not return with interrupts enabled) Reported-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Link: https://lkml.kernel.org/r/20201120114925.594122626@infradead.org 
We call arch_cpu_idle() with RCU disabled, but then use
local_irq_{en,dis}able(), which invokes tracing, which relies on RCU.

Switch all arch_cpu_idle() implementations to use
raw_local_irq_{en,dis}able() and carefully manage the
lockdep,rcu,tracing state like we do in entry.

(XXX: we really should change arch_cpu_idle() to not return with
interrupts enabled)

Reported-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lkml.kernel.org/r/20201120114925.594122626@infradead.org