Eliminate a useless task_work on execve by moving the call to
rseq_set_notify_resume() from sched_mm_cid_after_execve() to the error
path of bprm_execve().

The call to rseq_set_notify_resume() from sched_mm_cid_after_execve() is
pointless in the success case, because rseq_execve() will clear the rseq
pointer before returning to userspace.

sched_mm_cid_after_execve() is called from both the success and error
paths of bprm_execve(). The call to rseq_set_notify_resume() is needed
on error because the mm_cid may have changed.

Also move the rseq_execve() to right after sched_mm_cid_after_execve()
in bprm_execve().

[ mingo: Merged to a recent upstream kernel, extended the changelog. ]

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20250327132945.1558783-1-mathieu.desnoyers@efficios.com

Pull latency tracing updates from Steven Rostedt:

 - Add some trace events to osnoise and timerlat sample generation

   This adds more information to the osnoise and timerlat tracers as
   well as allows BPF programs to be attached to these locations to
   extract even more data.

 - Fix to DECLARE_TRACE_CONDITION() macro

   It wasn't used but now will be and it happened to be broken causing
   the build to fail.

 - Add scheduler specification monitors to runtime verifier (RV)

   This is a continuation of Daniel Bristot's work.

   RV allows monitors to run and react concurrently. Running the
   cumulative model is equivalent to running single components using the
   same reactors, with the advantage that it's easier to point out which
   specification failed in case of error.

   This update introduces nested monitors to RV, in short, the sysfs
   monitor folder will contain a monitor named sched, which is nothing
   but an empty container for other monitors. Controlling the sched
   monitor (enable, disable, set reactors) controls all nested monitors.

   The following scheduling monitors are added:

     - sco: scheduling context operations
       Monitor to ensure sched_set_state happens only in thread context

     - tss: task switch while scheduling
       Monitor to ensure sched_switch happens only in scheduling context

     - snroc: set non runnable on its own context
       Monitor to ensure set_state happens only in the respective task's context

     - scpd: schedule called with preemption disabled
       Monitor to ensure schedule is called with preemption disabled

     - snep: schedule does not enable preempt
       Monitor to ensure schedule does not enable preempt

     - sncid: schedule not called with interrupt disabled
       Monitor to ensure schedule is not called with interrupt disabled

* tag 'trace-latency-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  tools/rv: Allow rv list to filter for container
  Documentation/rv: Add docs for the sched monitors
  verification/dot2k: Add support for nested monitors
  tools/rv: Add support for nested monitors
  rv: Add scpd, snep and sncid per-cpu monitors
  rv: Add snroc per-task monitor
  rv: Add sco and tss per-cpu monitors
  rv: Add option for nested monitors and include sched
  sched: Add sched tracepoints for RV task model
  rv: Add license identifiers to monitor files
  tracing: Fix DECLARE_TRACE_CONDITION
  trace/osnoise: Add trace events for samples

Pull timer cleanups from Thomas Gleixner:
 "A treewide hrtimer timer cleanup

  hrtimers are initialized with hrtimer_init() and a subsequent store to
  the callback pointer. This turned out to be suboptimal for the
  upcoming Rust integration and is obviously a silly implementation to
  begin with.

  This cleanup replaces the hrtimer_init(T); T->function = cb; sequence
  with hrtimer_setup(T, cb);

  The conversion was done with Coccinelle and a few manual fixups.

  Once the conversion has completely landed in mainline, hrtimer_init()
  will be removed and the hrtimer::function becomes a private member"

* tag 'timers-cleanups-2025-03-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (100 commits)
  wifi: rt2x00: Switch to use hrtimer_update_function()
  io_uring: Use helper function hrtimer_update_function()
  serial: xilinx_uartps: Use helper function hrtimer_update_function()
  ASoC: fsl: imx-pcm-fiq: Switch to use hrtimer_setup()
  RDMA: Switch to use hrtimer_setup()
  virtio: mem: Switch to use hrtimer_setup()
  drm/vmwgfx: Switch to use hrtimer_setup()
  drm/xe/oa: Switch to use hrtimer_setup()
  drm/vkms: Switch to use hrtimer_setup()
  drm/msm: Switch to use hrtimer_setup()
  drm/i915/request: Switch to use hrtimer_setup()
  drm/i915/uncore: Switch to use hrtimer_setup()
  drm/i915/pmu: Switch to use hrtimer_setup()
  drm/i915/perf: Switch to use hrtimer_setup()
  drm/i915/gvt: Switch to use hrtimer_setup()
  drm/i915/huc: Switch to use hrtimer_setup()
  drm/amdgpu: Switch to use hrtimer_setup()
  stm class: heartbeat: Switch to use hrtimer_setup()
  i2c: Switch to use hrtimer_setup()
  iio: Switch to use hrtimer_setup()
  ...

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 RCU updates from Boqun Feng:
 "Documentation:
   - Add broken-timing possibility to stallwarn.rst
   - Improve discussion of this_cpu_ptr(), add raw_cpu_ptr()
   - Document self-propagating callbacks
   - Point call_srcu() to call_rcu() for detailed memory ordering
   - Add CONFIG_RCU_LAZY delays to call_rcu() kernel-doc header
   - Clarify RCU_LAZY and RCU_LAZY_DEFAULT_OFF help text
   - Remove references to old grace-period-wait primitives

  srcu:
   - Introduce srcu_read_{un,}lock_fast(), which is similar to
     srcu_read_{un,}lock_lite(): avoid smp_mb()s in lock and unlock
     at the cost of calling synchronize_rcu() in synchronize_srcu()

     Moreover, by returning the percpu offset of the counter at
     srcu_read_lock_fast() time, srcu_read_unlock_fast() can avoid
     extra pointer dereferencing, which makes it faster than
     srcu_read_{un,}lock_lite()

     srcu_read_{un,}lock_fast() are intended to replace
     rcu_read_{un,}lock_trace() if possible

  RCU torture:
   - Add get_torture_init_jiffies() to return the start time of the test
   - Add a test_boost_holdoff module parameter to allow delaying
     boosting tests when building rcutorture as built-in
   - Add grace period sequence number logging at the beginning and end
     of failure/close-call results
   - Switch to hexadecimal for the expedited grace period sequence
     number in the rcu_exp_grace_period trace point
   - Make cur_ops->format_gp_seqs take buffer length
   - Move RCU_TORTURE_TEST_{CHK_RDR_STATE,LOG_CPU} to bool
   - Complain when invalid SRCU reader_flavor is specified
   - Add FORCE_NEED_SRCU_NMI_SAFE Kconfig for testing, which forces SRCU
     uses atomics even when percpu ops are NMI safe, and use the Kconfig
     for SRCU lockdep testing

  Misc:
   - Split rcu_report_exp_cpu_mult() mask parameter and use for tracing
   - Remove READ_ONCE() for rdp->gpwrap access in __note_gp_changes()
   - Fix get_state_synchronize_rcu_full() GP-start detection
   - Move RCU Tasks self-tests to core_initcall()
   - Print segment lengths in show_rcu_nocb_gp_state()
   - Make RCU watch ct_kernel_exit_state() warning
   - Flush console log from kernel_power_off()
   - rcutorture: Allow a negative value for nfakewriters
   - rcu: Update TREE05.boot to test normal synchronize_rcu()
   - rcu: Use _full() API to debug synchronize_rcu()

  Make RCU handle PREEMPT_LAZY better:
   - Fix header guard for rcu_all_qs()
   - rcu: Rename PREEMPT_AUTO to PREEMPT_LAZY
   - Update __cond_resched comment about RCU quiescent states
   - Handle unstable rdp in rcu_read_unlock_strict()
   - Handle quiescent states for PREEMPT_RCU=n, PREEMPT_COUNT=y
   - osnoise: Provide quiescent states
   - Adjust rcutorture with possible PREEMPT_RCU=n && PREEMPT_COUNT=y
     combination
   - Limit PREEMPT_RCU configurations
   - Make rcutorture senario TREE07 and senario TREE10 use
     PREEMPT_LAZY=y"

* tag 'rcu-next-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/rcu/linux: (59 commits)
  rcutorture: Make scenario TREE07 build CONFIG_PREEMPT_LAZY=y
  rcutorture: Make scenario TREE10 build CONFIG_PREEMPT_LAZY=y
  rcu: limit PREEMPT_RCU configurations
  rcutorture: Update ->extendables check for lazy preemption
  rcutorture: Update rcutorture_one_extend_check() for lazy preemption
  osnoise: provide quiescent states
  rcu: Use _full() API to debug synchronize_rcu()
  rcu: Update TREE05.boot to test normal synchronize_rcu()
  rcutorture: Allow a negative value for nfakewriters
  Flush console log from kernel_power_off()
  context_tracking: Make RCU watch ct_kernel_exit_state() warning
  rcu/nocb: Print segment lengths in show_rcu_nocb_gp_state()
  rcu-tasks: Move RCU Tasks self-tests to core_initcall()
  rcu: Fix get_state_synchronize_rcu_full() GP-start detection
  torture: Make SRCU lockdep testing use srcu_read_lock_nmisafe()
  srcu: Add FORCE_NEED_SRCU_NMI_SAFE Kconfig for testing
  rcutorture: Complain when invalid SRCU reader_flavor is specified
  rcutorture: Move RCU_TORTURE_TEST_{CHK_RDR_STATE,LOG_CPU} to bool
  rcutorture: Make cur_ops->format_gp_seqs take buffer length
  rcutorture: Add ftrace-compatible timestamp to GP# failure/close-call output
  ...

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
  ...

Add the following tracepoints:
* sched_entry(bool preempt, ip)
    Called while entering __schedule
* sched_exit(bool is_switch, ip)
    Called while exiting __schedule
* sched_set_state(task, curr_state, state)
    Called when a task changes its state (to and from running)

These tracepoints are useful to describe the Linux task model and are
adapted from the patches by Daniel Bristot de Oliveira
(https://bristot.me/linux-task-model/).

Cc: Ingo Molnar <mingo@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Link: https://lore.kernel.org/20250305140406.350227-2-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

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

With CONFIG_SCHED_DEBUG becoming unconditional, remove the
extra 'const_debug' indirection towards __read_mostly.

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/20250317104257.3496611-3-mingo@kernel.org

The scheduler has this special SCHED_WARN() facility that
depends on CONFIG_SCHED_DEBUG.

Since CONFIG_SCHED_DEBUG is getting removed, convert
SCHED_WARN() to WARN_ON_ONCE().

Note that the warning output isn't 100% equivalent:

   #define SCHED_WARN_ON(x)      WARN_ONCE(x, #x)

Because SCHED_WARN_ON() would output the 'x' condition
as well, while WARN_ONCE() will only show a backtrace.

Hopefully these are rare enough to not really matter.

If it does, we should probably introduce a new WARN_ON()
variant that outputs the condition in stringified form,
or improve WARN_ON() itself.

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/20250317104257.3496611-2-mingo@kernel.org