Repository files (latest commit first)

Filename	Latest commit message	Latest commit date
Paul E. McKenney 4661cfd3f0 UPSTREAM: rcu-tasks: Add an RCU Tasks Trace to simplify protection of tracing hooks ... Because RCU does not watch exception early-entry/late-exit, idle-loop, or CPU-hotplug execution, protection of tracing and BPF operations is needlessly complicated. This commit therefore adds a variant of Tasks RCU that: o Has explicit read-side markers to allow finite grace periods in the face of in-kernel loops for PREEMPT=n builds. These markers are rcu_read_lock_trace() and rcu_read_unlock_trace(). o Protects code in the idle loop, exception entry/exit, and CPU-hotplug code paths. In this respect, RCU-tasks trace is similar to SRCU, but with lighter-weight readers. o Avoids expensive read-side instruction, having overhead similar to that of Preemptible RCU. There are of course downsides: o The grace-period code can send IPIs to CPUs, even when those CPUs are in the idle loop or in nohz_full userspace. This is mitigated by later commits. o It is necessary to scan the full tasklist, much as for Tasks RCU. o There is a single callback queue guarded by a single lock, again, much as for Tasks RCU. However, those early use cases that request multiple grace periods in quick succession are expected to do so from a single task, which makes the single lock almost irrelevant. If needed, multiple callback queues can be provided using any number of schemes. Perhaps most important, this variant of RCU does not affect the vanilla flavors, rcu_preempt and rcu_sched. The fact that RCU Tasks Trace readers can operate from idle, offline, and exception entry/exit in no way enables rcu_preempt and rcu_sched readers to do so. The memory ordering was outlined here: https://lore.kernel.org/lkml/20200319034030.GX3199@paulmck-ThinkPad-P72/ This effort benefited greatly from off-list discussions of BPF requirements with Alexei Starovoitov and Andrii Nakryiko. At least some of the on-list discussions are captured in the Link: tags below. In addition, KCSAN was quite helpful in finding some early bugs. Link: https://lore.kernel.org/lkml/20200219150744.428764577@infradead.org/ Link: https://lore.kernel.org/lkml/87mu8p797b.fsf@nanos.tec.linutronix.de/ Link: https://lore.kernel.org/lkml/20200225221305.605144982@linutronix.de/ Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com> Cc: Andrii Nakryiko <andriin@fb.com> [ paulmck: Apply feedback from Steve Rostedt and Joel Fernandes. ] [ paulmck: Decrement trc_n_readers_need_end upon IPI failure. ] [ paulmck: Fix locking issue reported by rcutorture. ] Change-Id: Ieccaadffa9dad8b0c1162b225e440b82338ed1e7 Signed-off-by: Paul E. McKenney <paulmck@kernel.org>		2026-01-14 18:12:26 -08:00
..
bpf	UPSTREAM: bpf: Relax max_entries check for most of the inner map types	2026-01-14 18:12:24 -08:00
cgroup	UPSTREAM: bpf: Refactor bpf_link update handling	2025-12-23 13:36:15 -08:00
configs
debug	kdb: Use the passed prompt in kdb_position_cursor()	2024-08-19 05:33:40 +02:00
dma	Merge tag 'ASB-2024-10-05_11-5.4' of https://android.googlesource.com/kernel/common into android13-5.4-lahaina	2024-10-09 18:08:17 +00:00
events	UPSTREAM: bpf: Fail PERF_EVENT_IOC_SET_BPF when bpf_get_[stack|stackid] cannot work	2026-01-14 18:12:08 -08:00
gcov	gcov: add support for GCC 15	2025-12-03 12:45:19 +01:00
irq	Merge branch 'android11-5.4-lts' of https://android.googlesource.com/kernel/common into android13-5.4-lahaina	2025-10-08 15:23:13 +03:00
livepatch	UPSTREAM: ftrace: Introduce PERMANENT ftrace_ops flag	2025-12-23 13:35:45 -08:00
locking	Merge tag 'ASB-2025-06-05_11-5.4' of https://android.googlesource.com/kernel/common into android13-5.4-lahaina	2025-06-30 10:49:17 +03:00
power	Merge tag 'ASB-2025-10-06_11-5.4' of https://android.googlesource.com/kernel/common into android13-5.4-lahaina	2025-10-08 15:17:54 +03:00
printk	BACKPORT: sysctl: pass kernel pointers to ->proc_handler	2025-12-23 13:36:15 -08:00
rcu	UPSTREAM: rcu-tasks: Add an RCU Tasks Trace to simplify protection of tracing hooks	2026-01-14 18:12:26 -08:00
sched	BACKPORT: sysctl: pass kernel pointers to ->proc_handler	2025-12-23 13:36:15 -08:00
time	BACKPORT: sysctl: pass kernel pointers to ->proc_handler	2025-12-23 13:36:15 -08:00
trace	UPSTREAM: bpf: Add d_path helper	2026-01-14 18:12:23 -08:00
.gitignore
acct.c	acct: perform last write from workqueue	2025-03-13 12:43:26 +01:00
async.c	treewide: Remove uninitialized_var() usage	2023-06-09 10:29:01 +02:00
audit.c	audit: Send netlink ACK before setting connection in auditd_set	2024-02-23 08:24:54 +01:00
audit.h	audit: log AUDIT_TIME_* records only from rules	2022-04-15 14:18:04 +02:00
audit_fsnotify.c	audit: fix potential double free on error path from fsnotify_add_inode_mark	2022-09-05 10:27:38 +02:00
audit_tree.c	audit: move put_tree() to avoid trim_trees refcount underflow and UAF	2021-09-03 10:08:16 +02:00
audit_watch.c	audit: don't WARN_ON_ONCE(!current->mm) in audit_exe_compare()	2023-11-28 16:50:18 +00:00
auditfilter.c
auditsc.c	audit: fix possible soft lockup in __audit_inode_child()	2023-09-23 10:59:46 +02:00
backtracetest.c	treewide: Replace DECLARE_TASKLET() with DECLARE_TASKLET_OLD()	2023-04-20 12:07:32 +02:00
bounds.c	bounds: Use the right number of bits for power-of-two CONFIG_NR_CPUS	2024-05-02 16:18:37 +02:00
capability.c
cfi.c
compat.c	sched_getaffinity: don't assume 'cpumask_size()' is fully initialized	2023-04-05 11:16:42 +02:00
configs.c
context_tracking.c
cpu.c	hrtimers: Handle CPU state correctly on hotplug	2025-02-01 18:18:51 +01:00
cpu_pm.c
crash_core.c
crash_dump.c
cred.c	Revert "cred: switch to using atomic_long_t"	2024-01-03 17:00:08 +00:00
delayacct.c
dma.c
exec_domain.c
exit.c	UPSTREAM: umd: Track user space drivers with struct pid	2026-01-14 18:12:15 -08:00
extable.c	UPSTREAM: bpf: Remove bpf_image tree	2025-12-23 13:36:07 -08:00
fail_function.c	kernel/fail_function: fix memory leak with using debugfs_lookup()	2023-03-11 16:44:15 +01:00
fork.c	UPSTREAM: rcu-tasks: Add an RCU Tasks Trace to simplify protection of tracing hooks	2026-01-14 18:12:26 -08:00
freezer.c
futex.c	Merge 5.4.246 into android11-5.4-lts	2023-06-20 19:13:58 +00:00
gen_kheaders.sh	Merge tag 'ASB-2025-03-05_11-5.4' into android13-5.4-lahaina	2025-04-12 09:31:28 +00:00
groups.c	BACKPORT: mm: remove the pgprot argument to __vmalloc	2026-01-14 17:48:09 -08:00
hung_task.c
iomem.c
irq_work.c	UPSTREAM: irq_work: Convert flags to atomic_t	2025-12-23 13:35:39 -08:00
jump_label.c
kallsyms.c
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kcov.c
kexec.c
kexec_core.c	kexec: fix a memory leak in crash_shrink_memory()	2023-07-27 08:37:10 +02:00
kexec_elf.c	kexec: initialize ELF lowest address to ULONG_MAX	2025-04-10 14:29:41 +02:00
kexec_file.c	kexec: support purgatories with .text.hot sections	2023-06-21 15:44:10 +02:00
kexec_internal.h
kheaders.c	kheaders: Use array declaration instead of char	2023-05-17 11:35:33 +02:00
kmod.c
kprobes.c	BACKPORT: sysctl: pass kernel pointers to ->proc_handler	2025-12-23 13:36:15 -08:00
ksysfs.c
kthread.c	This is the 5.4.285 stable release	2024-11-09 11:29:17 +00:00
latencytop.c	BACKPORT: sysctl: pass kernel pointers to ->proc_handler	2025-12-23 13:36:15 -08:00
Makefile	UPSTREAM: bpf: Add kernel module with user mode driver that populates bpffs.	2026-01-14 18:12:16 -08:00
module-internal.h
module.c	BACKPORT: mm: remove the pgprot argument to __vmalloc	2026-01-14 17:48:09 -08:00
module_signature.c
module_signing.c
notifier.c
nsproxy.c
padata.c	padata: Reset next CPU when reorder sequence wraps around	2025-10-29 14:00:01 +01:00
panic.c	panic: Flush kernel log buffer at the end	2024-04-13 12:51:37 +02:00
params.c	module: ensure that kobject_put() is safe for module type kobjects	2025-06-04 14:32:27 +02:00
pid.c	Merge tag 'ASB-2025-12-01_11-5.4' of https://android.googlesource.com/kernel/common into android13-5.4-lahaina	2025-12-04 19:21:35 +02:00
pid_namespace.c	BACKPORT: sysctl: pass kernel pointers to ->proc_handler	2025-12-23 13:36:15 -08:00
profile.c	profiling: fix shift too large makes kernel panic	2022-08-25 11:18:02 +02:00
ptrace.c	ptrace: Reimplement PTRACE_KILL by always sending SIGKILL	2022-06-14 18:11:24 +02:00
range.c
reboot.c	This is the 5.4.262 stable release	2023-11-29 10:18:14 +00:00
relay.c	relayfs: fix out-of-bounds access in relay_file_read	2023-05-17 11:35:58 +02:00
resource.c	resource: fix region_intersects() vs add_memory_driver_managed()	2024-11-08 16:20:46 +01:00
rseq.c
scs.c
seccomp.c	BACKPORT: sysctl: pass kernel pointers to ->proc_handler	2025-12-23 13:36:15 -08:00
signal.c	Merge tag 'ASB-2024-12-05_11-5.4' of https://android.googlesource.com/kernel/common into android13-5.4-lahaina	2024-12-17 03:24:53 +02:00
smp.c	Merge tag 'ASB-2024-11-05_11-5.4' of https://android.googlesource.com/kernel/common into android13-5.4-lahaina	2024-11-08 15:36:32 +00:00
smpboot.c
smpboot.h
softirq.c	Revert "tasklet: Introduce new initialization API"	2025-03-13 17:21:46 +00:00
stackleak.c
stacktrace.c
stop_machine.c
sys.c	Merge 5.4.272 into android11-5.4-lts	2024-04-05 12:37:33 +00:00
sys_ni.c	BACKPORT: epoll: wire up syscall epoll_pwait2	2025-12-22 07:42:50 +02:00
sysctl-test.c
sysctl.c	BACKPORT: bpf: Sharing bpf runtime stats with BPF_ENABLE_STATS	2025-12-23 13:36:17 -08:00
sysctl_binary.c
task_work.c
taskstats.c	taskstats: properly account NR_KERNEL_MISC_RECLAIMABLE	2021-07-01 06:18:34 -07:00
test_kprobes.c
torture.c
tracepoint.c	tracepoint: Add tracepoint_probe_register_may_exist() for BPF tracing	2021-07-14 16:53:08 +02:00
tsacct.c	taskstats: Cleanup the use of task->exit_code	2022-02-23 11:59:57 +01:00
ucount.c
uid16.c
uid16.h
umh.c	BACKPORT: umh: Separate the user mode driver and the user mode helper support	2026-01-14 18:12:14 -08:00
up.c
user-return-notifier.c
user.c
user_namespace.c
usermode_driver.c	UPSTREAM: umd: Track user space drivers with struct pid	2026-01-14 18:12:15 -08:00
utsname.c
utsname_sysctl.c	BACKPORT: sysctl: pass kernel pointers to ->proc_handler	2025-12-23 13:36:15 -08:00
watchdog.c	BACKPORT: sysctl: pass kernel pointers to ->proc_handler	2025-12-23 13:36:15 -08:00
watchdog_hld.c	watchdog/perf: properly initialize the turbo mode timestamp and rearm counter	2024-08-19 05:33:39 +02:00
workqueue.c	Merge android11-5.4.259+ (81334f2) into msm-5.4	2023-12-18 15:40:18 +05:30
workqueue_internal.h