linux/kernel
Linus Torvalds a7f2bc8787 RCU updates:
Execution contexts and call_rcu() and call_srcu():
  * Make call_rcu() and call_srcu invocable from NMI handlers and while
    holding scheduler locks (using irq-work handlers).
  * Add rcutorture and BPF tests calling these functions from these
    contexts.
  * Disable rcutorture overload testing for RCU readers that are "fragile",
    that is, that do not either disable preemption or have some form of
    RCU priority boosting.
 
 SRCU updates:
  * Add an atomic SRCU where readers run with preemption disabled and
    grace periods can be invoked from atomic contexts.  David Woodhouse
    has a patch series exploiting this for GPC.
  * Add torture and lockdep tests for atomic SRCU.
  * Add numerous optimizations for atomic SRCU based on the fact that it
    does not have callbacks, for example, eliminating any transition to
    "big" srcu_struct structures even on systems that configure these to
    happen at initialization time.
 
 Additional torture-test updates:
  * Fix a divide-by-zero bug in forward-progress testing.
  * Synchronously wait for all IRQ-queued callbacks to complete.
  * Allow alternative "ssh" commands to be specified for use by
    kvm-remote.sh.
  * Fix kvm-again.sh re-run failure on PowerPC.
  * Add additional lockdep testing for atomic SRCU.
  * Fix error double-counting in srcu_lockdep.sh.
  * Add atomic SRCU cross-CPU IRQ context mismatch testing, with the
  * trick being that the atomic SRCU readers context must be at least as
    strict as that of the atomic SRCU grace-period wait.  So for example,
    if the readers have IRQs disabled, so must the grace-period wait.
 
 Miscellaneous updates:
  * Update stallwarn.rst documentation for the re-implementation of RCU
    Tasks Trace in terms of SRCU.
  * Fix the lazy-callback shrink scanner budget computation so that it
    honors the reclaim budget.
  * Avoid panicking on RCU CPU stalls that end before the warning can
    be printed.
  * Add "running" and "boosted" indications to the RCU task stall warning
    output.
  * People have been (incorrectly) relying on rcu_barrier() to wait for
    kfree_rcu() callbacks and processing.  But it turns out to be easier to
    fix rcu_barrier() to meet their expectations than to fix their code to
    live within the earlier rcu_barrier() specification.  So rcu_barrier()
    now waits on kfree_rcu() callbacks and processing.
  * Disable RCU Tasks console output that track when this RCU flavor
    switches between per-CPU and global callback queuing.  New use cases
    appeared that generated enough console traffic to cause trouble, and
    no one seemed to care about these messages.  For those needing those
    messages, there is a new rcupdate.rcu_task_collapse_debug kernel boot
    parameter.
  * Fix __rcu pointer attribute handling to eliminate false positives.
  * Fix typos and drop redundant #include directives.
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Merge tag 'rcu.2026.10.12b' of git://git.kernel.org/pub/scm/linux/kernel/git/rcu/linux

Pull RCU updates from Paul McKenney:
 "Execution contexts and call_rcu() and call_srcu():
   - Make call_rcu() and call_srcu invocable from NMI handlers and while
     holding scheduler locks (using irq-work handlers)
   - Add rcutorture and BPF tests calling these functions from these
     contexts
   - Disable rcutorture overload testing for RCU readers that are
     "fragile", that is, that do not either disable preemption or have
     some form of RCU priority boosting

  SRCU updates:
   - Add an atomic SRCU where readers run with preemption disabled and
     grace periods can be invoked from atomic contexts. David Woodhouse
     has a patch series exploiting this for GPC
   - Add torture and lockdep tests for atomic SRCU
   - Add numerous optimizations for atomic SRCU based on the fact that
     it does not have callbacks, for example, eliminating any transition
     to "big" srcu_struct structures even on systems that configure
     these to happen at initialization time

  Additional torture-test updates:
   - Fix a divide-by-zero bug in forward-progress testing
   - Synchronously wait for all IRQ-queued callbacks to complete
   - Allow alternative "ssh" commands to be specified for use by
     kvm-remote.sh
   - Fix kvm-again.sh re-run failure on PowerPC
   - Add additional lockdep testing for atomic SRCU
   - Fix error double-counting in srcu_lockdep.sh
   - Add atomic SRCU cross-CPU IRQ context mismatch testing, with the
   - trick being that the atomic SRCU readers context must be at least
     as strict as that of the atomic SRCU grace-period wait. So for
     example, if the readers have IRQs disabled, so must the
     grace-period wait

  Miscellaneous updates:
   - Update stallwarn.rst documentation for the re-implementation of RCU
     Tasks Trace in terms of SRCU
   - Fix the lazy-callback shrink scanner budget computation so that it
     honors the reclaim budget
   - Avoid panicking on RCU CPU stalls that end before the warning can
     be printed
   - Add "running" and "boosted" indications to the RCU task stall
     warning output
   - People have been (incorrectly) relying on rcu_barrier() to wait for
     kfree_rcu() callbacks and processing. But it turns out to be easier
     to fix rcu_barrier() to meet their expectations than to fix their
     code to live within the earlier rcu_barrier() specification. So
     rcu_barrier() now waits on kfree_rcu() callbacks and processing
   - Disable RCU Tasks console output that track when this RCU flavor
     switches between per-CPU and global callback queuing. New use cases
     appeared that generated enough console traffic to cause trouble,
     and no one seemed to care about these messages. For those needing
     those messages, there is a new rcupdate.rcu_task_collapse_debug
     kernel boot parameter
   - Fix __rcu pointer attribute handling to eliminate false positives
   - Fix typos and drop redundant #include directives"

* tag 'rcu.2026.10.12b' of git://git.kernel.org/pub/scm/linux/kernel/git/rcu/linux: (46 commits)
  rcutorture: Add atomic SRCU cross-CPU IRQ context mismatch test
  selftests/rcutorture: Fix double nerrs count in srcu_lockdep.sh
  selftests/rcutorture: Wire atomic SRCU into srcu_lockdep.sh
  rcutorture: Add atomic SRCU lockdep support
  rcutorture: Fix kvm-again.sh re-run failure on ppc64
  torture:  Allow specifying alternative ssh command to kvm-remote.sh
  rcutorture: Synchronously wait for all rcu_torture_irq() callbacks to complete
  rcutorture: Fix divide-by-zero with fwd_progress_div=1
  srcutree: Preserve IRQ state in synchronize_srcu_atomic() callchain
  srcutiny: Add lockdep and early-boot checks to synchronize_srcu_atomic()
  srcutree: Add lockdep and early-boot checks to synchronize_srcu_atomic()
  srcutree: Skip torture to-big transition for atomic SRCU
  srcutree: Don't transition atomic SRCU to big in srcu_gp_end()
  srcutree: Make init_srcu_struct_atomic() prevent transition to big
  srcu: Restrict atomic-SRCU non_block annotation to task context
  srcutree: Remove srcu_barrier() sleep for atomic SRCU
  srcutree: Skip callback scheduling for atomic SRCU grace periods
  srcutree: Add reader-free fastpath to synchronize_srcu_atomic()
  rcutorture: Add atomic-SRCU support to torture.sh
  srcutree: Explicitly note DEFINE_SRCU() needs for srcu_barrier()
  ...
2026-10-21 10:04:13 -10:00
..
bpf vfs-7.4-rc1.idmap 2026-10-19 17:57:49 -10:00
cgroup cgroup: Fixes for v7.3-rc6 2026-10-07 02:19:02 +02:00
configs slab: support for compiler-assisted type-based slab cache partitioning 2026-05-14 10:44:09 +02:00
debug kgdb: update outdated references to kgdb_wait() 2026-04-21 16:41:54 +01:00
dma dma-mapping fixes for Linux 7.3 2026-10-10 00:49:55 +02:00
entry Merge __{get,put}_user() removal branch 2026-10-21 07:19:30 -10:00
events Merge __{get,put}_user() removal branch 2026-10-21 07:19:30 -10:00
futex futex: Fix mm reuse handling for FUT_OFF_MMSHARED 2026-10-14 15:11:48 +02:00
gcov Convert more 'alloc_obj' cases to default GFP_KERNEL arguments 2026-02-21 20:03:00 -08:00
irq Locking updates: 2026-10-20 12:43:05 -10:00
kcsan kcsan: avoid unintended access checking in NMIs 2026-07-20 18:18:37 +02:00
livepatch livepatch: Fix NULL pointer dereference in klp_find_func() 2026-07-07 12:54:37 +02:00
liveupdate kho: make boot time huge page allocation work nicely with KHO 2026-08-23 09:17:38 -07:00
locking Misc locking fixes: 2026-09-06 10:45:46 -07:00
module module: fix lost error code from codetag_load_module() 2026-09-26 13:55:09 -07:00
power Core features: 2026-10-20 07:55:19 -10:00
printk printk: Postpone kthread startup 2026-10-16 17:07:29 +02:00
rcu Merge branches 'misc.2026.10.06a' and 'torture.2026.10.12a' into HEAD 2026-10-12 16:53:20 -07:00
sched Scheduler updates: 2026-10-20 12:35:35 -10:00
tests userns: rename insert_extent() and sort_idmaps() 2026-09-11 15:00:37 +02:00
time Scheduler updates: 2026-10-20 12:35:35 -10:00
trace bpf: Use get_user() for kprobe_multi symbols and uprobe_multi arrays 2026-10-19 19:23:30 -10:00
unwind Convert more 'alloc_obj' cases to default GFP_KERNEL arguments 2026-02-21 20:03:00 -08:00
.gitignore
acct.c fs: move SB_I_USERNS_VISIBLE to FS_USERNS_MOUNT_RESTRICTED 2026-05-11 23:13:01 +02:00
async.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
audit_fsnotify.c audit: fix recursive locking deadlock in audit_dupe_exe() 2026-05-27 19:15:34 -04:00
audit_tree.c Automated merge of 'audit/dev' into 'stable-7.4' 2026-10-16 09:36:00 -04:00
audit_watch.c audit: Fix filter rule accounting after automatic removal 2026-09-01 17:35:19 -04:00
audit.c audit: use copied skb length in kauditd_send_multicast_skb() 2026-08-31 13:52:41 -04:00
audit.h audit: separate file and process capability storage 2026-09-28 18:10:56 -04:00
auditfilter.c audit: Fix filter rule accounting after automatic removal 2026-09-01 17:35:19 -04:00
auditsc.c lsm/stable-7.4 PR 20261016 2026-10-20 20:04:07 -10:00
backtracetest.c
bounds.c x86/asm: Remove ANNOTATE_DATA_SPECIAL usage 2025-12-03 16:53:19 +01:00
capability.c vfs-7.4-rc1.idmap 2026-10-19 17:57:49 -10:00
cfi.c
compat.c compat: use scoped user access in get_compat_sigevent() 2026-10-19 19:23:18 -10:00
configs.c
context_tracking.c context_tracking: Remove rcu_task_trace_heavyweight_{enter,exit}() 2026-01-01 16:39:46 +08:00
cpu_pm.c
cpu.c cpumask: Introduce cpu_preferred_mask 2026-09-28 08:44:41 +02:00
crash_core_test.c
crash_core.c crash: Update stale NR_CPUS_DEFAULT references in elfcorehdr sizing docs 2026-09-02 14:25:16 -07:00
crash_dump_dm_crypt.c crash_dump: release keyring reference at the correct time 2026-07-13 10:04:47 +03:00
crash_reserve.c kernel/crash: remove inclusion of crypto/sha1.h 2026-03-27 21:19:46 -07:00
cred.c cred: prevent slab cache merging for cred_jar 2026-09-09 17:48:37 -04:00
delayacct.c sysctl: remove CONFIG_PROC_SYSCTL, it just mirrors CONFIG_SYSCTL 2026-08-05 15:28:23 +02:00
dma.c
elfcorehdr.c
exec_domain.c
exec_state.c exec_state: relocate dumpable information 2026-05-26 11:02:01 +02:00
exit.c vfs-7.4-rc1.sync_close 2026-10-19 21:03:21 -10:00
exit.h
extable.c
fail_function.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
fork.c vfs-7.4-rc1.sync_close 2026-10-19 21:03:21 -10:00
freezer.c
gen_kheaders.sh
groups.c treewide: Replace kmalloc with kmalloc_obj for non-scalar types 2026-02-21 01:02:28 -08:00
hung_task.c hung_task: explicitly report I/O wait state in log output 2026-03-27 21:19:40 -07:00
iomem.c
irq_work.c irq_work: Flush lazy work CPU down on PREEMPT_RT 2026-10-01 14:00:35 +02:00
jump_label.c treewide: refresh kmalloc_obj() conversions 2026-09-04 21:37:00 -07:00
kallsyms_internal.h kallsyms: Get rid of kallsyms relative base 2026-01-22 15:58:22 -07:00
kallsyms_selftest.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
kallsyms_selftest.h
kallsyms.c mm.git review status for linus..mm-nonmm-stable 2026-02-12 12:13:01 -08:00
kcmp.c fs: add real_fs to track task's actual fs_struct 2026-06-29 10:43:45 +02:00
Kconfig.freezer
Kconfig.hz
Kconfig.kexec crash: Update stale NR_CPUS_DEFAULT references in elfcorehdr sizing docs 2026-09-02 14:25:16 -07:00
Kconfig.locks locking/qspinlock: Add contended_release tracepoint 2026-08-07 17:58:10 +02:00
Kconfig.preempt cpumask: Introduce cpu_preferred_mask 2026-09-28 08:44:41 +02:00
kcov.c mm.git review status for master..mm-nonmm-stable 2026-08-23 08:07:11 -07:00
kexec_core.c liveupdate: skip serialization for context-preserving kexec 2026-06-01 09:19:38 +03:00
kexec_elf.c
kexec_file.c kexec_file: skip checksum verification when safe 2026-07-01 13:01:08 +03:00
kexec_internal.h
kexec.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
kheaders.c
kprobes.c kprobes: Skip disarmed probes when checking optkprobe overlap 2026-10-02 15:51:57 +09:00
kstack_erase.c
ksyms_common.c
ksysfs.c kernel: ksysfs: initialize kernel_kobj earlier 2026-04-03 19:39:52 +02:00
kthread.c vfs-7.4-rc1.coredump 2026-10-19 17:21:24 -10:00
latencytop.c
Makefile userns: Add KUnit test suite for uid_gid_map 2026-09-09 09:45:01 +02:00
module_signature.c module: Give 'enum pkey_id_type' a more specific name 2026-03-24 21:42:37 +00:00
notifier.c
nscommon.c lsm: add LSM blob and hooks for namespaces 2026-08-31 16:14:10 -04:00
nsproxy.c lsm/stable-7.4 PR 20261016 2026-10-20 20:04:07 -10:00
nstree.c nstree: check listing permission before taking a namespace reference 2026-09-09 10:03:15 +02:00
padata.c padata: Put CPU offline callback in ONLINE section to allow failure 2026-03-22 11:17:59 +09:00
panic.c bug/kunit: Core support for suppressing warning backtraces 2026-05-14 10:50:00 -06:00
params.c mm.git review status for master..mm-nonmm-stable 2026-08-23 08:07:11 -07:00
pid_namespace.c kernel-7.4-rc1.signal 2026-10-19 16:22:15 -10:00
pid_sysctl.h
pid.c pid: use READ_ONCE() in pid_alive() 2026-10-12 11:13:01 +02:00
profile.c
ptrace.c Merge __{get,put}_user() removal branch 2026-10-21 07:19:30 -10:00
range.c
reboot.c Merge branch 'for-7.3-hotfix' into for-linus 2026-10-16 17:38:25 +02:00
regset.c
relay.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
resource_kunit.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
resource.c resource: downgrade "resource sanity check" warning to debug level 2026-08-03 21:10:05 -07:00
rseq.c rseq: Reenable performance optimizations conditionally 2026-05-06 17:40:27 +02:00
scftorture.c smp_call_function() torture-test updates: 2026-08-23 19:28:04 -07:00
scs.c
seccomp.c seccomp, treewide: Rename and convert __secure_computing() to return boolean 2026-07-12 12:38:02 +02:00
signal.c Merge __{get,put}_user() removal branch 2026-10-21 07:19:30 -10:00
smp.c irq_work: Flush lazy work CPU down on PREEMPT_RT 2026-10-01 14:00:35 +02:00
smpboot.c smpboot: Don't park the thread if work is pending 2026-10-01 14:00:36 +02:00
smpboot.h
softirq.c interrupt: Disable interrupt before modifying hardirq_disable counter 2026-08-30 08:39:04 +02:00
stacktrace.c
static_call_inline.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
static_call.c
stop_machine.c stop_machine: Make stop_one_cpu_nowait() return void 2026-07-31 12:35:26 +02:00
sys_ni.c time: Respect COMPAT_32BIT_TIME for old time type functions 2026-07-07 23:52:53 +02:00
sys.c prctl: fix PR_SET_MM_AUXV losing the forced AT_NULL terminator 2026-08-19 19:55:05 -07:00
sysctl-test.c
sysctl.c sysctl: Negate before converting in the int read path 2026-09-29 09:25:14 +02:00
task_work.c
taskstats.c taskstats: fold the two cpumask handlers into one 2026-08-13 15:42:05 -07:00
torture.c torture: Don't leak shuffle_tmp_mask when shuffler kthread fails to start 2026-08-14 14:59:21 -07:00
tracepoint.c tracepoint: balance regfunc() on func_add() failure in tracepoint_add_func() 2026-04-14 05:17:02 -04:00
tsacct.c tsacct: skip all kernel threads 2026-01-26 19:07:13 -08:00
ucount.c binfmt_misc: correctly account pre-opened interpreters 2026-08-03 23:36:18 +02:00
uid16.c
uid16.h
umh.c fs: add umh argument to struct kernel_clone_args 2026-06-29 10:54:41 +02:00
up.c smp: Refactor remote CPU selection in smp_call_function_any() 2026-07-16 09:24:55 +02:00
user_namespace.c vfs-7.4-rc1.idmap 2026-10-19 17:57:49 -10:00
user-return-notifier.c
user.c binfmt_misc: use RCU for the handler lookup 2026-08-03 10:08:36 +02:00
utsname_sysctl.c sysctl: remove CONFIG_PROC_SYSCTL, it just mirrors CONFIG_SYSCTL 2026-08-05 15:28:23 +02:00
utsname.c uts: drop BUG_ON() in copy_utsname() 2026-09-04 12:46:45 +02:00
vhost_task.c vhost_task_create: kill unnecessary .exit_signal initialization 2026-06-10 02:17:00 -04:00
vmcore_info.c mm.git review status for linus..mm-nonmm-stable 2026-04-16 20:11:56 -07:00
watch_queue.c watch_queue: Fix note pool publication race in watch_queue_set_size() 2026-10-14 22:08:02 +02:00
watchdog_buddy.c watchdog/hardlockup: improve buddy system detection timeliness 2026-03-27 21:19:47 -07:00
watchdog_perf.c watchdog/hardlockup: simplify perf event probe and remove per-cpu dependency 2026-02-08 00:13:35 -08:00
watchdog.c watchdog/softlockup: fix softlockup typos 2026-08-03 21:10:06 -07:00
workqueue_internal.h workqueue: Show in-flight work item duration in stall diagnostics 2026-03-05 07:27:48 -10:00
workqueue.c workqueue: Fix NULL current_pwq deref in mem-reclaim helper 2026-10-07 07:57:17 -10:00