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There is a problem with the behavior of hwlat in a container,
resulting in incorrect output. A warning message is generated:
"cpumask changed while in round-robin mode, switching to mode none",
and the tracing_cpumask is ignored. This issue arises because
the kernel thread, hwlatd, is not a part of the container, and
the function sched_setaffinity is unable to locate it using its PID.
Additionally, the task_struct of hwlatd is already known.
Ultimately, the function set_cpus_allowed_ptr achieves
the same outcome as sched_setaffinity, but employs task_struct
instead of PID.
Test case:
# cd /sys/kernel/tracing
# echo 0 > tracing_on
# echo round-robin > hwlat_detector/mode
# echo hwlat > current_tracer
# unshare --fork --pid bash -c 'echo 1 > tracing_on'
# dmesg -c
Actual behavior:
[573502.809060] hwlat_detector: cpumask changed while in round-robin mode, switching to mode none
Link: https://lore.kernel.org/linux-trace-kernel/20230316144535.1004952-1-costa.shul@redhat.com
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Fixes: 0330f7aa8e ("tracing: Have hwlat trace migrate across tracing_cpumask CPUs")
Signed-off-by: Costa Shulyupin <costa.shul@redhat.com>
Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Since the commit 36e2c7421f ("fs: don't allow splice read/write
without explicit ops") is applied to the kernel, splice() and
sendfile() calls on the trace file (/sys/kernel/debug/tracing
/trace) return EINVAL.
This patch restores these system calls by initializing splice_read
in file_operations of the trace file. This patch only enables such
functionalities for the read case.
Link: https://lore.kernel.org/linux-trace-kernel/20230314013707.28814-1-sfoon.kim@samsung.com
Cc: stable@vger.kernel.org
Fixes: 36e2c7421f ("fs: don't allow splice read/write without explicit ops")
Signed-off-by: Sung-hun Kim <sfoon.kim@samsung.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
smatch reports several similar warnings
kernel/trace/trace_osnoise.c:220:1: warning:
symbol '__pcpu_scope_per_cpu_osnoise_var' was not declared. Should it be static?
kernel/trace/trace_osnoise.c:243:1: warning:
symbol '__pcpu_scope_per_cpu_timerlat_var' was not declared. Should it be static?
kernel/trace/trace_osnoise.c:335:14: warning:
symbol 'interface_lock' was not declared. Should it be static?
kernel/trace/trace_osnoise.c:2242:5: warning:
symbol 'timerlat_min_period' was not declared. Should it be static?
kernel/trace/trace_osnoise.c:2243:5: warning:
symbol 'timerlat_max_period' was not declared. Should it be static?
These variables are only used in trace_osnoise.c, so it should be static
Link: https://lore.kernel.org/linux-trace-kernel/20230309150414.4036764-1-trix@redhat.com
Signed-off-by: Tom Rix <trix@redhat.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Overwriting the error code with the deletion result may cause the
function to return 0 despite encountering an error. Commit b111545d26
("tracing: Remove the useless value assignment in
test_create_synth_event()") solves a similar issue by
returning the original error code, so this patch does the same.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Link: https://lore.kernel.org/linux-trace-kernel/20230131075818.5322-1-aagusev@ispras.ru
Signed-off-by: Anton Gusev <aagusev@ispras.ru>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
A while ago where the trace events had the following:
rcu_read_lock_sched_notrace();
rcu_dereference_sched(...);
rcu_read_unlock_sched_notrace();
If the tracepoint is enabled, it could trigger RCU issues if called in
the wrong place. And this warning was only triggered if lockdep was
enabled. If the tracepoint was never enabled with lockdep, the bug would
not be caught. To handle this, the above sequence was done when lockdep
was enabled regardless if the tracepoint was enabled or not (although the
always enabled code really didn't do anything, it would still trigger a
warning).
But a lot has changed since that lockdep code was added. One is, that
sequence no longer triggers any warning. Another is, the tracepoint when
enabled doesn't even do that sequence anymore.
The main check we care about today is whether RCU is "watching" or not.
So if lockdep is enabled, always check if rcu_is_watching() which will
trigger a warning if it is not (tracepoints require RCU to be watching).
Note, that old sequence did add a bit of overhead when lockdep was enabled,
and with the latest kernel updates, would cause the system to slow down
enough to trigger kernel "stalled" warnings.
Link: http://lore.kernel.org/lkml/20140806181801.GA4605@redhat.com
Link: http://lore.kernel.org/lkml/20140807175204.C257CAC5@viggo.jf.intel.com
Link: https://lore.kernel.org/lkml/20230307184645.521db5c9@gandalf.local.home/
Link: https://lore.kernel.org/linux-trace-kernel/20230310172856.77406446@gandalf.local.home
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Fixes: e6753f23d9 ("tracepoint: Make rcuidle tracepoint callers use SRCU")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
KASAN reported follow problem:
BUG: KASAN: use-after-free in lookup_rec
Read of size 8 at addr ffff000199270ff0 by task modprobe
CPU: 2 Comm: modprobe
Call trace:
kasan_report
__asan_load8
lookup_rec
ftrace_location
arch_check_ftrace_location
check_kprobe_address_safe
register_kprobe
When checking pg->records[pg->index - 1].ip in lookup_rec(), it can get a
pg which is newly added to ftrace_pages_start in ftrace_process_locs().
Before the first pg->index++, index is 0 and accessing pg->records[-1].ip
will cause this problem.
Don't check the ip when pg->index is 0.
Link: https://lore.kernel.org/linux-trace-kernel/20230309080230.36064-1-chenzhongjin@huawei.com
Cc: stable@vger.kernel.org
Fixes: 9644302e33 ("ftrace: Speed up search by skipping pages by address")
Suggested-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The function hist_field_name() cannot handle being passed a NULL field
parameter. It should never be NULL, but due to a previous bug, NULL was
passed to the function and the kernel crashed due to a NULL dereference.
Mark Rutland reported this to me on IRC.
The bug was fixed, but to prevent future bugs from crashing the kernel,
check the field and add a WARN_ON() if it is NULL.
Link: https://lkml.kernel.org/r/20230302020810.762384440@goodmis.org
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Reported-by: Mark Rutland <mark.rutland@arm.com>
Fixes: c6afad49d1 ("tracing: Add hist trigger 'sym' and 'sym-offset' modifiers")
Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
In the case of keeping the system running, the preferred method for
tracing the kernel is dynamic tracing (kprobe), but the drawback of
this method is that events are lost, especially when tracing packages
in the network stack.
Livepatching provides a potential solution, which is to reimplement the
function you want to replace and insert a static tracepoint.
In such a way, custom stable static tracepoints can be expanded without
rebooting the system.
Link: https://lkml.kernel.org/r/20221102160236.11696-1-iecedge@gmail.com
Signed-off-by: Jianlin Lv <iecedge@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The canonical location for the tracefs filesystem is at /sys/kernel/tracing.
But, from Documentation/trace/ftrace.rst:
Before 4.1, all ftrace tracing control files were within the debugfs
file system, which is typically located at /sys/kernel/debug/tracing.
For backward compatibility, when mounting the debugfs file system,
the tracefs file system will be automatically mounted at:
/sys/kernel/debug/tracing
Many comments and Kconfig help messages in the tracing code still refer
to this older debugfs path, so let's update them to avoid confusion.
Link: https://lore.kernel.org/linux-trace-kernel/20230215223350.2658616-2-zwisler@google.com
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Mukesh Ojha <quic_mojha@quicinc.com>
Signed-off-by: Ross Zwisler <zwisler@google.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The current code will always use the current stacktrace as a key even
if a stacktrace contained in a specific event field was specified.
For example, we expect to use the 'unsigned long[] stack' field in the
below event in the histogram:
# echo 's:block_lat pid_t pid; u64 delta; unsigned long[] stack;' > /sys/kernel/debug/tracing/dynamic_events
# echo 'hist:keys=delta.buckets=100,stack.stacktrace:sort=delta' > /sys/kernel/debug/tracing/events/synthetic/block_lat/trigger
But in fact, when we type out the trigger, we see that it's using the
plain old global 'stacktrace' as the key, which is just the stacktrace
when the event was hit and not the stacktrace contained in the event,
which is what we want:
# cat /sys/kernel/debug/tracing/events/synthetic/block_lat/trigger
hist:keys=delta.buckets=100,stacktrace:vals=hitcount:sort=delta.buckets=100:size=2048 [active]
And in fact, there's no code to actually retrieve it from the event,
so we need to add HIST_FIELD_FN_STACK and hist_field_stack() to get it
and hook it into the trigger code. For now, since the stack is just
using dynamic strings, this could just use the dynamic string
function, but it seems cleaner to have a dedicated function an be able
to tweak independently as necessary.
Link: https://lkml.kernel.org/r/11aa614c82976adbfa4ea763dbe885b5fb01d59c.1676063532.git.zanussi@kernel.org
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
[ Fixed 32bit build warning reported by kernel test robot <lkp@intel.com> ]
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Currently, there are a few problems when printing hist triggers and
trace output when using stacktrace variables. This fixes the problems
seen below:
# echo 'hist:keys=delta.buckets=100,stack.stacktrace:sort=delta' > /sys/kernel/debug/tracing/events/synthetic/block_lat/trigger
# cat /sys/kernel/debug/tracing/events/synthetic/block_lat/trigger
hist:keys=delta.buckets=100,stacktrace:vals=hitcount:sort=delta.buckets=100:size=2048 [active]
# echo 'hist:keys=next_pid:ts=common_timestamp.usecs,st=stacktrace if prev_state == 2' >> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
hist:keys=next_pid:vals=hitcount:ts=common_timestamp.usecs,st=stacktrace.stacktrace:sort=hitcount:size=2048:clock=global if prev_state == 2 [active]
and also in the trace output (should be stack.stacktrace):
{ delta: ~ 100-199, stacktrace __schedule+0xa19/0x1520
Link: https://lkml.kernel.org/r/60bebd4e546728e012a7a2bcbf58716d48ba6edb.1676063532.git.zanussi@kernel.org
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The max string length for a histogram variable is 256 bytes. The max depth
of a stacktrace is 16. With 8byte words, that's 16 * 8 = 128. Which can
easily fit in the string variable. The histogram stacktrace is being
stored in the string value (with the given max length), with the
assumption it will fit. To make sure that this is always the case (in the
case that the stack trace depth increases), add a BUILD_BUG_ON() to test
this.
Link: https://lore.kernel.org/linux-trace-kernel/20230214002418.0103b9e765d3e5c374d2aa7d@kernel.org/
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Because stacktraces are saved in dynamic strings,
trace_event_raw_event_synth() uses strlen to determine the length of
the stack. Stacktraces may contain 0-bytes, though, in the saved
addresses, so the length found and passed to reserve() will be too
small.
Fix this by using the first unsigned long in the stack variables to
store the actual number of elements in the stack and have
trace_event_raw_event_synth() use that to determine the length of the
stack.
Link: https://lkml.kernel.org/r/1ed6906cd9d6477ef2bd8e63c61de20a9ffe64d7.1676063532.git.zanussi@kernel.org
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
smatch reports this representative issue
samples/ftrace/ftrace-ops.c:15:14: warning: symbol 'nr_function_calls' was not declared. Should it be static?
The nr_functions_calls and several other global variables are only
used in ftrace-ops.c, so they should be static.
Remove the instances of initializing static int to 0.
Link: https://lore.kernel.org/linux-trace-kernel/20230130193708.1378108-1-trix@redhat.com
Signed-off-by: Tom Rix <trix@redhat.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Calculating the average period requires a 64-bit division that leads
to a link failure on 32-bit architectures:
x86_64-linux-ld: samples/ftrace/ftrace-ops.o: in function `ftrace_ops_sample_init':
ftrace-ops.c:(.init.text+0x23b): undefined reference to `__udivdi3'
Use the div_u64() helper to do this instead. Since this is an init function that
is not called frequently, the runtime overhead is going to be acceptable.
Link: https://lore.kernel.org/linux-trace-kernel/20230130130246.247537-1-arnd@kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Fixes: b56c68f705 ("ftrace: Add sample with custom ops")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
When other architectures without the nospec functionality write their
direct-call functions of samples/ftrace/*.c, the including of
asm/nospec-branch.h must be taken care to fix the no header file found
error in building process.
This commit (ee3e2469b3 "x86/ftrace: Make it call depth tracking aware")
file-globally includes asm/nospec-branch.h providing CALL_DEPTH_ACCOUNT
for only x86 direct-call functions.
It seems better to move the including to `#ifdef CONFIG_X86_64`.
Link: https://lore.kernel.org/linux-trace-kernel/20230130085954.647845-1-suagrfillet@gmail.com
Signed-off-by: Song Shuai <suagrfillet@gmail.com>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
there is one dwc3 trace event declare as below,
DECLARE_EVENT_CLASS(dwc3_log_event,
TP_PROTO(u32 event, struct dwc3 *dwc),
TP_ARGS(event, dwc),
TP_STRUCT__entry(
__field(u32, event)
__field(u32, ep0state)
__dynamic_array(char, str, DWC3_MSG_MAX)
),
TP_fast_assign(
__entry->event = event;
__entry->ep0state = dwc->ep0state;
),
TP_printk("event (%08x): %s", __entry->event,
dwc3_decode_event(__get_str(str), DWC3_MSG_MAX,
__entry->event, __entry->ep0state))
);
the problem is when trace function called, it will allocate up to
DWC3_MSG_MAX bytes from trace event buffer, but never fill the buffer
during fast assignment, it only fill the buffer when output function are
called, so this means if output function are not called, the buffer will
never used.
add __get_buf(len) which acquiree buffer from iter->tmp_seq when trace
output function called, it allow user write string to acquired buffer.
the mentioned dwc3 trace event will changed as below,
DECLARE_EVENT_CLASS(dwc3_log_event,
TP_PROTO(u32 event, struct dwc3 *dwc),
TP_ARGS(event, dwc),
TP_STRUCT__entry(
__field(u32, event)
__field(u32, ep0state)
),
TP_fast_assign(
__entry->event = event;
__entry->ep0state = dwc->ep0state;
),
TP_printk("event (%08x): %s", __entry->event,
dwc3_decode_event(__get_buf(DWC3_MSG_MAX), DWC3_MSG_MAX,
__entry->event, __entry->ep0state))
);.
Link: https://lore.kernel.org/linux-trace-kernel/1675065249-23368-1-git-send-email-quic_linyyuan@quicinc.com
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Linyu Yuan <quic_linyyuan@quicinc.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Allow a stacktrace from one event to be displayed by the end event of a
synthetic event. This is very useful when looking for the longest latency
of a sleep or something blocked on I/O.
# cd /sys/kernel/tracing/
# echo 's:block_lat pid_t pid; u64 delta; unsigned long[] stack;' > dynamic_events
# echo 'hist:keys=next_pid:ts=common_timestamp.usecs,st=stacktrace if prev_state == 1||prev_state == 2' > events/sched/sched_switch/trigger
# echo 'hist:keys=prev_pid:delta=common_timestamp.usecs-$ts,s=$st:onmax($delta).trace(block_lat,prev_pid,$delta,$s)' >> events/sched/sched_switch/trigger
The above creates a "block_lat" synthetic event that take the stacktrace of
when a task schedules out in either the interruptible or uninterruptible
states, and on a new per process max $delta (the time it was scheduled
out), will print the process id and the stacktrace.
# echo 1 > events/synthetic/block_lat/enable
# cat trace
# TASK-PID CPU# ||||| TIMESTAMP FUNCTION
# | | | ||||| | |
kworker/u16:0-767 [006] d..4. 560.645045: block_lat: pid=767 delta=66 stack=STACK:
=> __schedule
=> schedule
=> pipe_read
=> vfs_read
=> ksys_read
=> do_syscall_64
=> 0x966000aa
<idle>-0 [003] d..4. 561.132117: block_lat: pid=0 delta=413787 stack=STACK:
=> __schedule
=> schedule
=> schedule_hrtimeout_range_clock
=> do_sys_poll
=> __x64_sys_poll
=> do_syscall_64
=> 0x966000aa
<...>-153 [006] d..4. 562.068407: block_lat: pid=153 delta=54 stack=STACK:
=> __schedule
=> schedule
=> io_schedule
=> rq_qos_wait
=> wbt_wait
=> __rq_qos_throttle
=> blk_mq_submit_bio
=> submit_bio_noacct_nocheck
=> ext4_bio_write_page
=> mpage_submit_page
=> mpage_process_page_bufs
=> mpage_prepare_extent_to_map
=> ext4_do_writepages
=> ext4_writepages
=> do_writepages
=> __writeback_single_inode
Link: https://lkml.kernel.org/r/20230117152236.010941267@goodmis.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: Ross Zwisler <zwisler@google.com>
Cc: Ching-lin Yu <chinglinyu@google.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Allow to save stacktraces into a histogram variable. This will be used by
synthetic events to allow a stacktrace from one event to be passed and
displayed by another event.
The special keyword "stacktrace" is to be used to trigger a stack
trace for the event that the histogram trigger is attached to.
echo 'hist:keys=pid:st=stacktrace" > events/sched/sched_waking/trigger
Currently nothing can get access to the "$st" variable above that contains
the stack trace, but that will soon change.
Link: https://lkml.kernel.org/r/20230117152235.856323729@goodmis.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: Ross Zwisler <zwisler@google.com>
Cc: Ching-lin Yu <chinglinyu@google.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
In a previous commit 7433632c9f, buffer, buffer->buffers and
buffer->buffers[cpu] in ring_buffer_wake_waiters() can be NULL,
and thus the related checks are added.
However, in the same call stack, these variables are also used in
ring_buffer_free_read_page():
tracing_buffers_release()
ring_buffer_wake_waiters(iter->array_buffer->buffer)
cpu_buffer = buffer->buffers[cpu] -> Add checks by previous commit
ring_buffer_free_read_page(iter->array_buffer->buffer)
cpu_buffer = buffer->buffers[cpu] -> No check
Thus, to avod possible null-pointer derefernces, the related checks
should be added.
These results are reported by a static tool designed by myself.
Link: https://lkml.kernel.org/r/20230113125501.760324-1-baijiaju1990@gmail.com
Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
There's been several times where an event records a function address in
its field and I needed to filter on that address for a specific function
name. It required looking up the function in kallsyms, finding its size,
and doing a compare of "field >= function_start && field < function_end".
But this would change from boot to boot and is unreliable in scripts.
Also, it is useful to have this at boot up, where the addresses will not
be known. For example, on the boot command line:
trace_trigger="initcall_finish.traceoff if func.function == acpi_init"
To implement this, add a ".function" prefix, that will check that the
field is of size long, and the only operations allowed (so far) are "=="
and "!=".
Link: https://lkml.kernel.org/r/20221219183213.916833763@goodmis.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: Zheng Yejian <zhengyejian1@huawei.com>
Reviewed-by: Ross Zwisler <zwisler@google.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Use the 'struct' keyword for a struct's kernel-doc notation and
use the correct function parameter name to eliminate kernel-doc
warnings:
kernel/trace/trace_events_filter.c:136: warning: cannot understand function prototype: 'struct prog_entry '
kerne/trace/trace_events_filter.c:155: warning: Excess function parameter 'when_to_branch' description in 'update_preds'
Also correct some trivial punctuation problems.
Link: https://lkml.kernel.org/r/20230108021238.16398-1-rdunlap@infradead.org
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
list_for_each_entry_rcu() has built-in RCU and lock checking.
Pass cond argument to list_for_each_entry_rcu() to silence false lockdep
warning when CONFIG_PROVE_RCU_LIST is enabled.
Execute as follow:
[tracing]# echo osnoise > current_tracer
[tracing]# echo 1 > tracing_on
[tracing]# echo 0 > tracing_on
The trace_types_lock is held when osnoise_tracer_stop() or
timerlat_tracer_stop() are called in the non-RCU read side section.
So, pass lockdep_is_held(&trace_types_lock) to silence false lockdep
warning.
Link: https://lkml.kernel.org/r/20221227023036.784337-1-nashuiliang@gmail.com
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Fixes: dae181349f ("tracing/osnoise: Support a list of trace_array *tr")
Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Chuang Wang <nashuiliang@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
