Pull objtool fixes from Ingo Molnar:
 "These are objtool fixes and updates by Josh Poimboeuf, centered around
  the fallout from the new CONFIG_OBJTOOL_WERROR=y feature, which,
  despite its default-off nature, increased the profile/impact of
  objtool warnings:

   - Improve error handling and the presentation of warnings/errors

   - Revert the new summary warning line that some test-bot tools
     interpreted as new regressions

   - Fix a number of objtool warnings in various drivers, core kernel
     code and architecture code. About half of them are potential
     problems related to out-of-bounds accesses or potential undefined
     behavior, the other half are additional objtool annotations

   - Update objtool to latest (known) compiler quirks and objtool bugs
     triggered by compiler code generation

   - Misc fixes"

* tag 'objtool-urgent-2025-04-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits)
  objtool/loongarch: Add unwind hints in prepare_frametrace()
  rcu-tasks: Always inline rcu_irq_work_resched()
  context_tracking: Always inline ct_{nmi,irq}_{enter,exit}()
  sched/smt: Always inline sched_smt_active()
  objtool: Fix verbose disassembly if CROSS_COMPILE isn't set
  objtool: Change "warning:" to "error: " for fatal errors
  objtool: Always fail on fatal errors
  Revert "objtool: Increase per-function WARN_FUNC() rate limit"
  objtool: Append "()" to function name in "unexpected end of section" warning
  objtool: Ignore end-of-section jumps for KCOV/GCOV
  objtool: Silence more KCOV warnings, part 2
  objtool, drm/vmwgfx: Don't ignore vmw_send_msg() for ORC
  objtool: Fix STACK_FRAME_NON_STANDARD for cold subfunctions
  objtool: Fix segfault in ignore_unreachable_insn()
  objtool: Fix NULL printf() '%s' argument in builtin-check.c:save_argv()
  objtool, lkdtm: Obfuscate the do_nothing() pointer
  objtool, regulator: rk808: Remove potential undefined behavior in rk806_set_mode_dcdc()
  objtool, ASoC: codecs: wcd934x: Remove potential undefined behavior in wcd934x_slim_irq_handler()
  objtool, Input: cyapa - Remove undefined behavior in cyapa_update_fw_store()
  objtool, panic: Disable SMAP in __stack_chk_fail()
  ...

sched_smt_active() can be called from noinstr code, so it should always
be inlined.  The CONFIG_SCHED_SMT version already has __always_inline.
Do the same for its !CONFIG_SCHED_SMT counterpart.

Fixes the following warning:

  vmlinux.o: error: objtool: intel_idle_ibrs+0x13: call to sched_smt_active() leaves .noinstr.text section

Fixes: 321a874a7ef8 ("sched/smt: Expose sched_smt_present static key")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/1d03907b0a247cf7fb5c1d518de378864f603060.1743481539.git.jpoimboe@kernel.org
Closes: https://lore.kernel.org/r/202503311434.lyw2Tveh-lkp@intel.com/

Pull timer core updates from Thomas Gleixner:

 - Fix a memory ordering issue in posix-timers

   Posix-timer lookup is lockless and reevaluates the timer validity
   under the timer lock, but the update which validates the timer is not
   protected by the timer lock. That allows the store to be reordered
   against the initialization stores, so that the lookup side can
   observe a partially initialized timer. That's mostly a theoretical
   problem, but incorrect nevertheless.

 - Fix a long standing inconsistency of the coarse time getters

   The coarse time getters read the base time of the current update
   cycle without reading the actual hardware clock. NTP frequency
   adjustment can set the base time backwards. The fine grained
   interfaces compensate this by reading the clock and applying the new
   conversion factor, but the coarse grained time getters use the base
   time directly. That allows the user to observe time going backwards.

   Cure it by always forwarding base time, when NTP changes the
   frequency with an immediate step.

 - Rework of posix-timer hashing

   The posix-timer hash is not scalable and due to the CRIU timer
   restore mechanism prone to massive contention on the global hash
   bucket lock.

   Replace the global hash lock with a fine grained per bucket locking
   scheme to address that.

 - Rework the proc/$PID/timers interface.

   /proc/$PID/timers is provided for CRIU to be able to restore a timer.
   The printout happens with sighand lock held and interrupts disabled.
   That's not required as this can be done with RCU protection as well.

 - Provide a sane mechanism for CRIU to restore a timer ID

   CRIU restores timers by creating and deleting them until the kernel
   internal per process ID counter reached the requested ID. That's
   horribly slow for sparse timer IDs.

   Provide a prctl() which allows CRIU to restore a timer with a given
   ID. When enabled the ID pointer is used as input pointer to read the
   requested ID from user space. When disabled, the normal allocation
   scheme (next ID) is active as before. This is backwards compatible
   for both kernel and user space.

 - Make hrtimer_update_function() less expensive.

   The sanity checks are valuable, but expensive for high frequency
   usage in io/uring. Make the debug checks conditional and enable them
   only when lockdep is enabled.

 - Small updates, cleanups and improvements

* tag 'timers-core-2025-03-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (27 commits)
  selftests/timers: Improve skew_consistency by testing with other clockids
  timekeeping: Fix possible inconsistencies in _COARSE clockids
  posix-timers: Drop redundant memset() invocation
  selftests/timers/posix-timers: Add a test for exact allocation mode
  posix-timers: Provide a mechanism to allocate a given timer ID
  posix-timers: Dont iterate /proc/$PID/timers with sighand:: Siglock held
  posix-timers: Make per process list RCU safe
  posix-timers: Avoid false cacheline sharing
  posix-timers: Switch to jhash32()
  posix-timers: Improve hash table performance
  posix-timers: Make signal_struct:: Next_posix_timer_id an atomic_t
  posix-timers: Make lock_timer() use guard()
  posix-timers: Rework timer removal
  posix-timers: Simplify lock/unlock_timer()
  posix-timers: Use guards in a few places
  posix-timers: Remove SLAB_PANIC from kmem cache
  posix-timers: Remove a few paranoid warnings
  posix-timers: Cleanup includes
  posix-timers: Add cond_resched() to posix_timer_add() search loop
  posix-timers: Initialise timer before adding it to the hash table
  ...

Pull scheduler updates from Ingo Molnar:
 "Core & fair scheduler changes:

   - Cancel the slice protection of the idle entity (Zihan Zhou)
   - Reduce the default slice to avoid tasks getting an extra tick
     (Zihan Zhou)
   - Force propagating min_slice of cfs_rq when {en,de}queue tasks
     (Tianchen Ding)
   - Refactor can_migrate_task() to elimate looping (I Hsin Cheng)
   - Add unlikey branch hints to several system calls (Colin Ian King)
   - Optimize current_clr_polling() on certain architectures (Yujun
     Dong)

  Deadline scheduler: (Juri Lelli)
   - Remove redundant dl_clear_root_domain call
   - Move dl_rebuild_rd_accounting to cpuset.h

  Uclamp:
   - Use the uclamp_is_used() helper instead of open-coding it (Xuewen
     Yan)
   - Optimize sched_uclamp_used static key enabling (Xuewen Yan)

  Scheduler topology support: (Juri Lelli)
   - Ignore special tasks when rebuilding domains
   - Add wrappers for sched_domains_mutex
   - Generalize unique visiting of root domains
   - Rebuild root domain accounting after every update
   - Remove partition_and_rebuild_sched_domains
   - Stop exposing partition_sched_domains_locked

  RSEQ: (Michael Jeanson)
   - Update kernel fields in lockstep with CONFIG_DEBUG_RSEQ=y
   - Fix segfault on registration when rseq_cs is non-zero
   - selftests: Add rseq syscall errors test
   - selftests: Ensure the rseq ABI TLS is actually 1024 bytes

  Membarriers:
   - Fix redundant load of membarrier_state (Nysal Jan K.A.)

  Scheduler debugging:
   - Introduce and use preempt_model_str() (Sebastian Andrzej Siewior)
   - Make CONFIG_SCHED_DEBUG unconditional (Ingo Molnar)

  Fixes and cleanups:
   - Always save/restore x86 TSC sched_clock() on suspend/resume
     (Guilherme G. Piccoli)
   - Misc fixes and cleanups (Thorsten Blum, Juri Lelli, Sebastian
     Andrzej Siewior)"

* tag 'sched-core-2025-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (40 commits)
  cpuidle, sched: Use smp_mb__after_atomic() in current_clr_polling()
  sched/debug: Remove CONFIG_SCHED_DEBUG
  sched/debug: Remove CONFIG_SCHED_DEBUG from self-test config files
  sched/debug, Documentation: Remove (most) CONFIG_SCHED_DEBUG references from documentation
  sched/debug: Make CONFIG_SCHED_DEBUG functionality unconditional
  sched/debug: Make 'const_debug' tunables unconditional __read_mostly
  sched/debug: Change SCHED_WARN_ON() to WARN_ON_ONCE()
  rseq/selftests: Fix namespace collision with rseq UAPI header
  include/{topology,cpuset}: Move dl_rebuild_rd_accounting to cpuset.h
  sched/topology: Stop exposing partition_sched_domains_locked
  cgroup/cpuset: Remove partition_and_rebuild_sched_domains
  sched/topology: Remove redundant dl_clear_root_domain call
  sched/deadline: Rebuild root domain accounting after every update
  sched/deadline: Generalize unique visiting of root domains
  sched/topology: Wrappers for sched_domains_mutex
  sched/deadline: Ignore special tasks when rebuilding domains
  tracing: Use preempt_model_str()
  xtensa: Rely on generic printing of preemption model
  x86: Rely on generic printing of preemption model
  s390: Rely on generic printing of preemption model
  ...

Pull sched_ext updates from Tejun Heo:

 - Add mechanism to count and report internal events. This significantly
   improves visibility on subtle corner conditions.

 - The default idle CPU selection logic is revamped and improved in
   multiple ways including being made topology aware.

 - sched_ext was disabling ttwu_queue for simplicity, which can be
   costly when hardware topology is more complex. Implement
   SCX_OPS_ALLOWED_QUEUED_WAKEUP so that BPF schedulers can selectively
   enable ttwu_queue.

 - tools/sched_ext updates to improve compatibility among others.

 - Other misc updates and fixes.

 - sched_ext/for-6.14-fixes were pulled a few times to receive
   prerequisite fixes and resolve conflicts.

* tag 'sched_ext-for-6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext: (42 commits)
  sched_ext: idle: Refactor scx_select_cpu_dfl()
  sched_ext: idle: Honor idle flags in the built-in idle selection policy
  sched_ext: Skip per-CPU tasks in scx_bpf_reenqueue_local()
  sched_ext: Add trace point to track sched_ext core events
  sched_ext: Change the event type from u64 to s64
  sched_ext: Documentation: add task lifecycle summary
  tools/sched_ext: Provide a compatible helper for scx_bpf_events()
  selftests/sched_ext: Add NUMA-aware scheduler test
  tools/sched_ext: Provide consistent access to scx flags
  sched_ext: idle: Fix scx_bpf_pick_any_cpu_node() behavior
  sched_ext: idle: Introduce scx_bpf_nr_node_ids()
  sched_ext: idle: Introduce node-aware idle cpu kfunc helpers
  sched_ext: idle: Per-node idle cpumasks
  sched_ext: idle: Introduce SCX_OPS_BUILTIN_IDLE_PER_NODE
  sched_ext: idle: Make idle static keys private
  sched/topology: Introduce for_each_node_numadist() iterator
  mm/numa: Introduce nearest_node_nodemask()
  nodemask: numa: reorganize inclusion path
  nodemask: add nodes_copy()
  tools/sched_ext: Sync with scx repo
  ...

In architectures that use the polling bit, current_clr_polling() employs
smp_mb() to ensure that the clearing of the polling bit is visible to
other cores before checking TIF_NEED_RESCHED.

However, smp_mb() can be costly. Given that clear_bit() is an atomic
operation, replacing smp_mb() with smp_mb__after_atomic() is appropriate.

Many architectures implement smp_mb__after_atomic() as a lighter-weight
barrier compared to smp_mb(), leading to performance improvements.
For instance, on x86, smp_mb__after_atomic() is a no-op. This change
eliminates a smp_mb() instruction in the cpuidle wake-up path, saving
several CPU cycles and thereby reducing wake-up latency.

Architectures that do not use the polling bit will retain the original
smp_mb() behavior to ensure that existing dependencies remain unaffected.

Signed-off-by: Yujun Dong <yujundong@pascal-lab.net>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20241230141624.155356-1-yujundong@pascal-lab.net

All the big Linux distros enable CONFIG_SCHED_DEBUG, because
the various features it provides help not just with kernel
development, but with system administration and user-space
software development as well.

Reflect this reality and enable this functionality
unconditionally.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ben Segall <bsegall@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Valentin Schneider <vschneid@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20250317104257.3496611-4-mingo@kernel.org

dl_rebuild_rd_accounting() is defined in cpuset.c, so it makes more
sense to move related declarations to cpuset.h.

Implement the move.

Suggested-by: Waiman Long <llong@redhat.com>
Signed-off-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Waiman Long <llong@redhat.com>
Reviewed-by: Valentin Schneider <vschneid@redhat.com>
Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Tested-by: Waiman Long <longman@redhat.com>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Link: https://lore.kernel.org/r/Z9MSOVMpU7jpVrMU@jlelli-thinkpadt14gen4.remote.csb

The are no callers of partition_sched_domains_locked() outside
topology.c.

Stop exposing such function.

Suggested-by: Waiman Long <llong@redhat.com>
Signed-off-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <vschneid@redhat.com>
Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Tested-by: Waiman Long <longman@redhat.com>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Link: https://lore.kernel.org/r/Z9MSC96a8FcqWV3G@jlelli-thinkpadt14gen4.remote.csb

Rebuilding of root domains accounting information (total_bw) is
currently broken on some cases, e.g. suspend/resume on aarch64. Problem
is that the way we keep track of domain changes and try to add bandwidth
back is convoluted and fragile.

Fix it by simplify things by making sure bandwidth accounting is cleared
and completely restored after root domains changes (after root domains
are again stable).

To be sure we always call dl_rebuild_rd_accounting while holding
cpuset_mutex we also add cpuset_reset_sched_domains() wrapper.

Fixes: 53916d5fd3c0 ("sched/deadline: Check bandwidth overflow earlier for hotplug")
Reported-by: Jon Hunter <jonathanh@nvidia.com>
Co-developed-by: Waiman Long <llong@redhat.com>
Signed-off-by: Waiman Long <llong@redhat.com>
Signed-off-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Link: https://lore.kernel.org/r/Z9MRfeJKJUOyUSto@jlelli-thinkpadt14gen4.remote.csb