sst-linux/kernel
Steven Rostedt (Google) 3a70b1c932 tracing: Use .flush() call to wake up readers
commit e5d7c1916562f0e856eb3d6f569629fcd535fed2 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>
2024-04-03 15:19:40 +02:00
..
bpf bpf: report RCU QS in cpumap kthread 2024-03-26 18:21:02 -04:00
cgroup cgroup_freezer: cgroup_freezing: Check if not frozen 2023-12-13 18:39:19 +01:00
configs Kbuild: add Rust support 2022-09-28 09:02:20 +02:00
debug kdb: Fix a potential buffer overflow in kdb_local() 2024-01-25 15:27:51 -08:00
dma dma-mapping: clear dev->dma_mem to NULL after freeing it 2024-01-25 15:27:28 -08:00
entry entry/rcu: Check TIF_RESCHED _after_ delayed RCU wake-up 2023-03-30 12:49:13 +02:00
events perf: Fix the nr_addr_filters fix 2024-02-05 20:13:00 +00:00
futex futex: Don't include process MM in futex key on no-MMU 2023-11-20 11:51:50 +01:00
gcov gcov: add support for checksum field 2022-12-31 13:33:11 +01:00
irq genirq/affinity: Move group_cpus_evenly() into lib/ 2024-01-10 17:10:33 +01:00
kcsan kcsan: Don't expect 64 bits atomic builtins from 32 bits architectures 2023-07-19 16:21:37 +02:00
livepatch livepatch: Fix missing newline character in klp_resolve_symbols() 2023-11-20 11:52:10 +01:00
locking lockdep: Fix block chain corruption 2023-12-03 07:32:09 +01:00
module modules: wait do_free_init correctly 2024-03-26 18:20:52 -04:00
power PM: suspend: Set mem_sleep_current during kernel command line setup 2024-04-03 15:19:28 +02:00
printk serial: Lock console when calling into driver before registration 2024-04-03 15:19:31 +02:00
rcu rcu/exp: Handle RCU expedited grace period kworker allocation failure 2024-03-26 18:20:28 -04:00
sched sched/fair: Take the scheduling domain into account in select_idle_core() 2024-03-26 18:20:30 -04:00
time timers: Rename del_timer_sync() to timer_delete_sync() 2024-04-03 15:19:23 +02:00
trace tracing: Use .flush() call to wake up readers 2024-04-03 15:19:40 +02:00
.gitignore
acct.c acct: fix potential integer overflow in encode_comp_t() 2022-12-31 13:32:58 +01:00
async.c async: Introduce async_schedule_dev_nocall() 2024-01-31 16:17:00 -08:00
audit_fsnotify.c audit: fix potential double free on error path from fsnotify_add_inode_mark 2022-08-22 18:50:06 -04:00
audit_tree.c
audit_watch.c audit: don't WARN_ON_ONCE(!current->mm) in audit_exe_compare() 2023-11-28 17:07:08 +00:00
audit.c audit: Send netlink ACK before setting connection in auditd_set 2024-02-05 20:12:47 +00:00
audit.h
auditfilter.c
auditsc.c audit,io_uring: io_uring openat triggers audit reference count underflow 2023-10-25 12:03:04 +02:00
backtracetest.c
bounds.c bounds: support non-power-of-two CONFIG_NR_CPUS 2024-04-03 15:19:27 +02:00
capability.c
cfi.c cfi: Switch to -fsanitize=kcfi 2022-09-26 10:13:13 -07:00
compat.c sched_getaffinity: don't assume 'cpumask_size()' is fully initialized 2023-04-06 12:10:40 +02:00
configs.c proc: convert everything to "struct proc_ops" 2020-02-04 03:05:26 +00:00
context_tracking.c context_tracking: Fix noinstr vs KASAN 2023-03-10 09:33:45 +01:00
cpu_pm.c context_tracking: Take IRQ eqs entrypoints over RCU 2022-07-05 13:32:59 -07:00
cpu.c cpu/SMT: Make SMT control more robust against enumeration failures 2024-01-10 17:10:26 +01:00
crash_core.c
crash_dump.c
cred.c cred: switch to using atomic_long_t 2023-12-20 17:00:20 +01:00
delayacct.c delayacct: support re-entrance detection of thrashing accounting 2022-09-26 19:46:07 -07:00
dma.c proc: introduce proc_create_single{,_data} 2018-05-16 07:23:35 +02:00
exec_domain.c
exit.c exit: Detect and fix irq disabled state in oops 2023-03-10 09:33:45 +01:00
extable.c
fail_function.c kernel/fail_function: fix memory leak with using debugfs_lookup() 2023-03-11 13:55:39 +01:00
fork.c kernel/fork: beware of __put_task_struct() calling context 2023-09-23 11:11:00 +02:00
freezer.c
gen_kheaders.sh kbuild: build init/built-in.a just once 2022-09-29 04:40:15 +09:00
groups.c
hung_task.c sched: Fix more TASK_state comparisons 2022-09-30 16:50:39 +02:00
iomem.c mm/nvdimm: add is_ioremap_addr and use that to check ioremap address 2019-07-12 11:05:40 -07:00
irq_work.c
jump_label.c
kallsyms_internal.h kallsyms: Reduce the memory occupied by kallsyms_seqs_of_names[] 2023-10-25 12:03:16 +02:00
kallsyms.c kallsyms: Add helper kallsyms_on_each_match_symbol() 2023-10-25 12:03:16 +02:00
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt Revert "signal, x86: Delay calling signals in atomic on RT enabled kernels" 2022-03-31 10:36:55 +02:00
kcov.c kcov: kmsan: unpoison area->list in kcov_remote_area_put() 2022-10-03 14:03:23 -07:00
kexec_core.c kexec: fix a memory leak in crash_shrink_memory() 2023-07-19 16:21:08 +02:00
kexec_elf.c
kexec_file.c kexec: support purgatories with .text.hot sections 2023-06-21 16:00:55 +02:00
kexec_internal.h panic, kexec: make __crash_kexec() NMI safe 2022-09-11 21:55:06 -07:00
kexec.c kernel: kexec: copy user-array safely 2023-11-28 17:06:57 +00:00
kheaders.c kheaders: Use array declaration instead of char 2023-05-11 23:03:02 +09:00
kmod.c
kprobes.c kprobes: consistent rcu api usage for kretprobe holder 2023-12-13 18:39:17 +01:00
ksysfs.c kexec: turn all kexec_mutex acquisitions into trylocks 2022-09-11 21:55:06 -07:00
kthread.c signal: break out of wait loops on kthread_stop() 2022-10-09 16:01:59 -07:00
latencytop.c latencytop: use the last element of latency_record of system 2022-09-11 21:55:12 -07:00
Makefile cfi: Fix CFI failure with KASAN 2022-12-31 13:33:08 +01:00
module_signature.c module: harden ELF info handling 2021-01-19 10:24:45 +01:00
notifier.c notifier: Add blocking/atomic_notifier_chain_register_unique_prio() 2022-05-19 19:30:30 +02:00
nsproxy.c Revert "fs/exec: allow to unshare a time namespace on vfork+exec" 2022-09-13 10:38:43 -07:00
padata.c crypto: pcrypt - Fix hungtask for PADATA_RESET 2023-11-28 17:06:58 +00:00
panic.c panic: Reenable preemption in WARN slowpath 2023-09-23 11:11:09 +02:00
params.c
pid_namespace.c rcu-tasks: Fix synchronize_rcu_tasks() VS zap_pid_ns_processes() 2023-03-10 09:32:52 +01:00
pid.c
profile.c kernel/profile.c: simplify duplicated code in profile_setup() 2022-09-11 21:55:12 -07:00
ptrace.c
range.c
reboot.c kernel/reboot: emergency_restart: Set correct system_state 2023-11-28 17:07:13 +00:00
regset.c
relay.c relayfs: fix out-of-bounds access in relay_file_read 2023-05-11 23:03:03 +09:00
resource_kunit.c
resource.c PCI: Allow drivers to request exclusive config regions 2023-09-13 09:42:46 +02:00
rseq.c rseq: Use pr_warn_once() when deprecated/unknown ABI flags are encountered 2022-11-14 09:58:32 +01:00
scftorture.c scftorture: Forgive memory-allocation failure if KASAN 2023-09-23 11:11:00 +02:00
scs.c
seccomp.c
signal.c mm: suppress mm fault logging if fatal signal already pending 2023-08-03 10:24:01 +02:00
smp.c smp,csd: Throw an error if a CSD lock is stuck for too long 2023-11-28 17:06:55 +00:00
smpboot.c smpboot: use atomic_try_cmpxchg in cpu_wait_death and cpu_report_death 2022-09-11 21:55:10 -07:00
smpboot.h
softirq.c
stackleak.c
stacktrace.c
static_call_inline.c
static_call.c static_call: Don't make __static_call_return0 static 2022-04-05 09:59:38 +02:00
stop_machine.c
sys_ni.c
sys.c getrusage: use sig->stats_lock rather than lock_task_sighand() 2024-03-15 10:48:22 -04:00
sysctl-test.c kernel/sysctl-test: use SYSCTL_{ZERO/ONE_HUNDRED} instead of i_{zero/one_hundred} 2022-09-08 16:56:45 -07:00
sysctl.c proc: proc_skip_spaces() shouldn't think it is working on C strings 2022-12-05 12:09:06 -08:00
task_work.c task_work: use try_cmpxchg in task_work_add, task_work_cancel_match and task_work_run 2022-09-11 21:55:10 -07:00
taskstats.c
torture.c torture: Fix hang during kthread shutdown phase 2023-03-10 09:34:07 +01:00
tracepoint.c tracepoint: Optimize the critical region of mutex_lock in tracepoint_module_coming() 2022-09-26 13:01:18 -04:00
tsacct.c
ucount.c
uid16.c
uid16.h kernel: provide ksys_*() wrappers for syscalls called by kernel/uid16.c 2018-04-02 20:15:30 +02:00
umh.c freezer,umh: Fix call_usermode_helper_exec() vs SIGKILL 2023-02-22 12:59:50 +01:00
up.c
user_namespace.c ucounts: Split rlimit and ucount values and max values 2022-10-09 16:24:05 -07:00
user-return-notifier.c
user.c
usermode_driver.c
utsname_sysctl.c kernel/utsname_sysctl.c: Fix hostname polling 2022-10-23 12:01:01 -07:00
utsname.c
watch_queue.c kernel: watch_queue: copy user-array safely 2023-11-28 17:06:57 +00:00
watchdog_hld.c watchdog/perf: more properly prevent false positives with turbo modes 2023-07-19 16:21:08 +02:00
watchdog.c watchdog: move softlockup_panic back to early_param 2023-11-28 17:07:09 +00:00
workqueue_internal.h workqueue: Assign a color to barrier work items 2021-08-17 07:49:10 -10:00
workqueue.c workqueue: Provide one lock class key per work_on_cpu() callsite 2023-11-28 17:06:55 +00:00