linux-stable/kernel
Steven Rostedt (Google) 898127d612 tracing: Use .flush() call to wake up readers
commit e5d7c19165 upstream.

The .release() function does not get called until all readers of a file
descriptor are finished.

If a thread is blocked on reading a file descriptor in ring_buffer_wait(),
and another thread closes the file descriptor, it will not wake up the
other thread as ring_buffer_wake_waiters() is called by .release(), and
that will not get called until the .read() is finished.

The issue originally showed up in trace-cmd, but the readers are actually
other processes with their own file descriptors. So calling close() would wake
up the other tasks because they are blocked on another descriptor then the
one that was closed(). But there's other wake ups that solve that issue.

When a thread is blocked on a read, it can still hang even when another
thread closed its descriptor.

This is what the .flush() callback is for. Have the .flush() wake up the
readers.

Link: https://lore.kernel.org/linux-trace-kernel/20240308202432.107909457@goodmis.org

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linke li <lilinke99@qq.com>
Cc: Rabin Vincent <rabin@rab.in>
Fixes: f3ddb74ad0 ("tracing: Wake up ring buffer waiters on closing of the file")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-04-10 16:18:45 +02:00
..
bpf bpf: report RCU QS in cpumap kthread 2024-03-26 18:21:37 -04:00
cgroup cgroup: Remove duplicates in cgroup v1 tasks file 2023-10-19 23:05:37 +02:00
configs
debug kdb: Fix a potential buffer overflow in kdb_local() 2024-01-25 14:52:54 -08:00
dma dma-mapping: clear dev->dma_mem to NULL after freeing it 2024-01-25 14:52:38 -08:00
entry entry/rcu: Check TIF_RESCHED _after_ delayed RCU wake-up 2023-03-30 12:47:51 +02:00
events perf: Fix the nr_addr_filters fix 2024-02-23 08:54:52 +01:00
futex futex: Don't include process MM in futex key on no-MMU 2023-11-20 11:08:13 +01:00
gcov gcov: add support for checksum field 2022-12-31 13:14:47 +01:00
irq genirq/generic_chip: Make irq_remove_generic_chip() irqdomain aware 2023-11-28 16:56:30 +00:00
kcsan kcsan: Don't expect 64 bits atomic builtins from 32 bits architectures 2023-07-23 13:47:12 +02:00
livepatch livepatch: Fix missing newline character in klp_resolve_symbols() 2023-11-20 11:08:25 +01:00
locking lockdep: Fix block chain corruption 2023-12-03 07:31:23 +01:00
power PM: suspend: Set mem_sleep_current during kernel command line setup 2024-04-10 16:18:36 +02:00
printk serial: Lock console when calling into driver before registration 2024-04-10 16:18:38 +02:00
rcu rcu-tasks: Provide rcu_trace_implies_rcu_gp() 2024-03-26 18:21:11 -04:00
sched sched/fair: Take the scheduling domain into account in select_idle_core() 2024-03-26 18:21:15 -04:00
time timers: Rename del_timer_sync() to timer_delete_sync() 2024-04-10 16:18:33 +02:00
trace tracing: Use .flush() call to wake up readers 2024-04-10 16:18:45 +02:00
.gitignore
acct.c acct: fix potential integer overflow in encode_comp_t() 2022-12-31 13:14:40 +01:00
async.c async: Introduce async_schedule_dev_nocall() 2024-02-23 08:54:25 +01:00
audit.c audit: Send netlink ACK before setting connection in auditd_set 2024-02-23 08:54:37 +01:00
audit.h audit: log AUDIT_TIME_* records only from rules 2022-04-08 14:23:06 +02:00
audit_fsnotify.c audit: fix potential double free on error path from fsnotify_add_inode_mark 2022-08-31 17:16:33 +02:00
audit_tree.c audit: move put_tree() to avoid trim_trees refcount underflow and UAF 2021-08-24 18:52:36 -04:00
audit_watch.c audit: don't WARN_ON_ONCE(!current->mm) in audit_exe_compare() 2023-11-28 16:56:27 +00:00
auditfilter.c
auditsc.c audit: fix possible soft lockup in __audit_inode_child() 2023-09-19 12:22:39 +02:00
backtracetest.c
bounds.c bounds: support non-power-of-two CONFIG_NR_CPUS 2024-04-10 16:18:35 +02:00
capability.c
cfi.c cfi: Fix __cfi_slowpath_diag RCU usage with cpuidle 2022-06-22 14:22:04 +02:00
compat.c sched_getaffinity: don't assume 'cpumask_size()' is fully initialized 2023-04-05 11:24:53 +02:00
configs.c
context_tracking.c
cpu.c hrtimers: Push pending hrtimers away from outgoing CPU earlier 2023-12-13 18:36:31 +01:00
cpu_pm.c PM: cpu: Make notifier chain use a raw_spinlock_t 2021-08-16 18:55:32 +02:00
crash_core.c kernel/crash_core: suppress unknown crashkernel parameter warning 2021-12-29 12:28:49 +01:00
crash_dump.c
cred.c cred: switch to using atomic_long_t 2023-12-20 15:17:37 +01:00
delayacct.c
dma.c
exec_domain.c
exit.c exit: Use READ_ONCE() for all oops/warn limit reads 2023-02-01 08:27:22 +01:00
extable.c
fail_function.c kernel/fail_function: fix memory leak with using debugfs_lookup() 2023-03-11 13:57:38 +01:00
fork.c kernel/fork: beware of __put_task_struct() calling context 2023-09-23 11:09:55 +02:00
freezer.c
gen_kheaders.sh
groups.c
hung_task.c Merge branch 'akpm' (patches from Andrew) 2021-07-02 12:08:10 -07:00
iomem.c
irq_work.c
jump_label.c jump_label: Fix jump_label_text_reserved() vs __init 2021-07-05 10:46:20 +02:00
kallsyms.c kallsyms: Make kallsyms_on_each_symbol generally available 2023-12-13 18:36:45 +01:00
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks locking/rwlock: Provide RT variant 2021-08-17 17:50:51 +02:00
Kconfig.preempt sched/core: Disable CONFIG_SCHED_CORE by default 2021-06-28 22:43:05 +02:00
kcov.c
kexec.c kernel: kexec: copy user-array safely 2023-11-28 16:56:16 +00:00
kexec_core.c kexec: fix a memory leak in crash_shrink_memory() 2023-07-23 13:46:52 +02:00
kexec_elf.c
kexec_file.c kexec: support purgatories with .text.hot sections 2023-06-21 15:59:14 +02:00
kexec_internal.h panic, kexec: make __crash_kexec() NMI safe 2023-04-20 12:13:57 +02:00
kheaders.c kheaders: Use array declaration instead of char 2023-05-11 23:00:17 +09:00
kmod.c
kprobes.c kprobes: Fix to handle forcibly unoptimized kprobes on freeing_list 2024-01-25 14:52:31 -08:00
ksysfs.c kexec: turn all kexec_mutex acquisitions into trylocks 2023-04-20 12:13:57 +02:00
kthread.c kthread: add the helper function kthread_run_on_cpu() 2023-03-30 12:47:42 +02:00
latencytop.c
Makefile futex: Move to kernel/futex/ 2022-12-31 13:14:04 +01:00
module-internal.h
module.c modules: wait do_free_init correctly 2024-03-26 18:21:31 -04:00
module_signature.c
module_signing.c
notifier.c notifier: Remove atomic_notifier_call_chain_robust() 2021-08-16 18:55:32 +02:00
nsproxy.c memcg: enable accounting for new namesapces and struct nsproxy 2021-09-03 09:58:12 -07:00
padata.c crypto: pcrypt - Fix hungtask for PADATA_RESET 2023-11-28 16:56:18 +00:00
panic.c exit: Use READ_ONCE() for all oops/warn limit reads 2023-02-01 08:27:22 +01:00
params.c params: lift param_set_uint_minmax to common code 2021-08-16 14:42:22 +02:00
pid.c kernel/pid.c: implement additional checks upon pidfd_create() parameters 2021-08-10 12:53:07 +02:00
pid_namespace.c rcu-tasks: Fix synchronize_rcu_tasks() VS zap_pid_ns_processes() 2023-03-10 09:39:09 +01:00
profile.c profiling: fix shift too large makes kernel panic 2022-08-17 14:24:04 +02:00
ptrace.c ptrace: Reimplement PTRACE_KILL by always sending SIGKILL 2022-06-09 10:22:29 +02:00
range.c
reboot.c kernel/reboot: emergency_restart: Set correct system_state 2023-11-28 16:56:31 +00:00
regset.c
relay.c relayfs: fix out-of-bounds access in relay_file_read 2023-05-11 23:00:18 +09:00
resource.c dax/kmem: Fix leak of memory-hotplug resources 2023-03-10 09:40:08 +01:00
resource_kunit.c
rseq.c rseq: Remove broken uapi field layout on 32-bit little endian 2022-04-08 14:23:10 +02:00
scftorture.c scftorture: Forgive memory-allocation failure if KASAN 2023-09-23 11:09:55 +02:00
scs.c scs: Release kasan vmalloc poison in scs_free process 2021-11-18 19:16:29 +01:00
seccomp.c seccomp: Invalidate seccomp mode to catch death failures 2022-02-16 12:56:38 +01:00
signal.c signal handling: don't use BUG_ON() for debugging 2022-07-21 21:24:42 +02:00
smp.c locking/csd_lock: Change csdlock_debug from early_param to __setup 2022-08-17 14:24:24 +02:00
smpboot.c smpboot: Replace deprecated CPU-hotplug functions. 2021-08-10 14:57:42 +02:00
smpboot.h
softirq.c timers/nohz: Last resort update jiffies on nohz_full IRQ entry 2023-08-16 18:22:04 +02:00
stackleak.c gcc-plugins/stackleak: Use noinstr in favor of notrace 2022-02-23 12:03:07 +01:00
stacktrace.c stacktrace: move filter_irq_stacks() to kernel/stacktrace.c 2022-04-13 20:59:28 +02:00
static_call.c static_call: Don't make __static_call_return0 static 2022-04-13 20:59:28 +02:00
static_call_inline.c static_call: Don't make __static_call_return0 static 2022-04-13 20:59:28 +02:00
stop_machine.c
sys.c getrusage: use sig->stats_lock rather than lock_task_sighand() 2024-03-15 10:48:22 -04:00
sys_ni.c kernel/sys_ni: add compat entry for fadvise64_64 2022-08-31 17:16:33 +02:00
sysctl-test.c
sysctl.c sched/rt: Disallow writing invalid values to sched_rt_period_us 2024-03-01 13:21:43 +01:00
task_work.c
taskstats.c
test_kprobes.c
torture.c torture: Fix hang during kthread shutdown phase 2023-08-30 16:18:19 +02:00
tracepoint.c tracepoint: Fix kerneldoc comments 2021-08-16 11:39:51 -04:00
tsacct.c taskstats: Cleanup the use of task->exit_code 2022-01-27 11:05:35 +01:00
ucount.c ucounts: Handle wrapping in is_ucounts_overlimit 2022-02-23 12:03:20 +01:00
uid16.c
uid16.h
umh.c
up.c
user-return-notifier.c
user.c fs/epoll: use a per-cpu counter for user's watches count 2021-09-08 11:50:27 -07:00
user_namespace.c ucounts: Fix systemd LimitNPROC with private users regression 2022-03-08 19:12:42 +01:00
usermode_driver.c Merge branch 'work.namei' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2021-07-03 11:41:14 -07:00
utsname.c
utsname_sysctl.c
watch_queue.c kernel: watch_queue: copy user-array safely 2023-11-28 16:56:16 +00:00
watchdog.c watchdog: move softlockup_panic back to early_param 2023-11-28 16:56:28 +00:00
watchdog_hld.c watchdog/perf: more properly prevent false positives with turbo modes 2023-07-23 13:46:52 +02:00
workqueue.c Revert "workqueue: remove unused cancel_work()" 2023-12-08 08:48:03 +01:00
workqueue_internal.h workqueue: Assign a color to barrier work items 2021-08-17 07:49:10 -10:00