tracing/trigger: Fix to return error if failed to alloc snapshot

commit 0958b33ef5a04ed91f61cef4760ac412080c4e08 upstream.

Fix register_snapshot_trigger() to return error code if it failed to
alloc

tracing/trigger: Fix to return error if failed to alloc snapshot

commit 0958b33ef5a04ed91f61cef4760ac412080c4e08 upstream.

Fix register_snapshot_trigger() to return error code if it failed to
allocate a snapshot instead of 0 (success). Unless that, it will register
snapshot trigger without an error.

Link: https://lore.kernel.org/linux-trace-kernel/170622977792.270660.2789298642759362200.stgit@devnote2

Fixes: 0bbe7f719985 ("tracing: Fix the race between registering 'snapshot' event trigger and triggering 'snapshot' operation")
Cc: stable@vger.kernel.org
Cc: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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tracing: Fix kernel-doc warnings in trace_events_trigger.c

Fix kernel-doc warnings:

kernel/trace/trace_events_trigger.c:59: warning: Function parameter
or member 'buffer' not described in 'event_tr

tracing: Fix kernel-doc warnings in trace_events_trigger.c

Fix kernel-doc warnings:

kernel/trace/trace_events_trigger.c:59: warning: Function parameter
or member 'buffer' not described in 'event_triggers_call'
kernel/trace/trace_events_trigger.c:59: warning: Function parameter
or member 'event' not described in 'event_triggers_call'

Link: https://lkml.kernel.org/r/20230724140827.1023266-4-cuigaosheng1@huawei.com

Cc: <mhiramat@kernel.org>
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

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tracing: Do not synchronize freeing of trigger filter on boot up

If a trigger filter on the kernel command line fails to apply (due to
syntax error), it will be freed. The freeing will call
tracepoi

tracing: Do not synchronize freeing of trigger filter on boot up

If a trigger filter on the kernel command line fails to apply (due to
syntax error), it will be freed. The freeing will call
tracepoint_synchronize_unregister(), but this is not needed during early
boot up, and will even trigger a lockdep splat.

Avoid calling the synchronization function when system_state is
SYSTEM_BOOTING.

Link: https://lore.kernel.org/linux-trace-kernel/20221213172429.7774f4ba@gandalf.local.home

Cc: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

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tracing: Have trigger filter parsing errors show up in error_log

It is annoying that the filter parsing of triggers do not show up in the
error_log. Trying to figure out what is incorrect in the inp

tracing: Have trigger filter parsing errors show up in error_log

It is annoying that the filter parsing of triggers do not show up in the
error_log. Trying to figure out what is incorrect in the input is
difficult when it fails for a typo.

Have the errors of filter parsing show up in error_log as well.

Link: https://lore.kernel.org/linux-trace-kernel/20221213095602.083fa9fd@gandalf.local.home

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

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tracing: Fix to check event_mutex is held while accessing trigger list

Since the check_user_trigger() is called outside of RCU
read lock, this list_for_each_entry_rcu() caused a suspicious
RCU usage

tracing: Fix to check event_mutex is held while accessing trigger list

Since the check_user_trigger() is called outside of RCU
read lock, this list_for_each_entry_rcu() caused a suspicious
RCU usage warning.

# echo hist:keys=pid > events/sched/sched_stat_runtime/trigger
# cat events/sched/sched_stat_runtime/trigger
[ 43.167032]
[ 43.167418] =============================
[ 43.167992] WARNING: suspicious RCU usage
[ 43.168567] 5.19.0-rc5-00029-g19ebe4651abf #59 Not tainted
[ 43.169283] -----------------------------
[ 43.169863] kernel/trace/trace_events_trigger.c:145 RCU-list traversed in non-reader section!!
...

However, this file->triggers list is safe when it is accessed
under event_mutex is held.
To fix this warning, adds a lockdep_is_held check to the
list_for_each_entry_rcu().

Link: https://lkml.kernel.org/r/166226474977.223837.1992182913048377113.stgit@devnote2

Cc: stable@vger.kernel.org
Fixes: 7491e2c44278 ("tracing: Add a probe that attaches to trace events")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

show more ...

tracing: Fix comments for event_trigger_separate_filter()

The parameter name in comments of event_trigger_separate_filter() is
inconsistent with actual parameter name, fix it.

Link: https://lkml.ke

tracing: Fix comments for event_trigger_separate_filter()

The parameter name in comments of event_trigger_separate_filter() is
inconsistent with actual parameter name, fix it.

Link: https://lkml.kernel.org/r/20220526072957.165655-1-sunliming@kylinos.cn

Signed-off-by: sunliming <sunliming@kylinos.cn>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

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tracing: Replace usage of found with dedicated list iterator variable

To move the list iterator variable into the list_for_each_entry_*()
macro in the future it should be avoided to use the list ite

tracing: Replace usage of found with dedicated list iterator variable

To move the list iterator variable into the list_for_each_entry_*()
macro in the future it should be avoided to use the list iterator
variable after the loop body.

To *never* use the list iterator variable after the loop it was
concluded to use a separate iterator variable instead of a
found boolean [1].

This removes the need to use a found variable and simply checking if
the variable was set, can determine if the break/goto was hit.

Link: https://lkml.kernel.org/r/20220427170734.819891-4-jakobkoschel@gmail.com

Cc: Ingo Molnar <mingo@redhat.com>
Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ [1]
Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

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tracing: Have existing event_command.parse() implementations use helpers

Simplify the existing event_command.parse() implementations by having
them make use of the helper functions previously introd

tracing: Have existing event_command.parse() implementations use helpers

Simplify the existing event_command.parse() implementations by having
them make use of the helper functions previously introduced.

Link: https://lkml.kernel.org/r/b353e3427a81f9d3adafd98fd7d73e78a8209f43.1644010576.git.zanussi@kernel.org

Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

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tracing: Remove redundant trigger_ops params

Since event_trigger_data contains the .ops trigger_ops field, there's
no reason to pass the trigger_ops separately. Remove it as a param
from functions w

tracing: Remove redundant trigger_ops params

Since event_trigger_data contains the .ops trigger_ops field, there's
no reason to pass the trigger_ops separately. Remove it as a param
from functions whenever event_trigger_data is passed.

Link: https://lkml.kernel.org/r/9856c9bc81bde57077f5b8d6f8faa47156c6354a.1644010575.git.zanussi@kernel.org

Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

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tracing: Remove logic for registering multiple event triggers at a time

Code for registering triggers assumes it's possible to register more
than one trigger at a time. In fact, it's unimplemented

tracing: Remove logic for registering multiple event triggers at a time

Code for registering triggers assumes it's possible to register more
than one trigger at a time. In fact, it's unimplemented and there
doesn't seem to be a reason to do that.

Remove the n_registered param from event_trigger_register() and fix up
callers.

Doing so simplifies the logic in event_trigger_register to the point
that it just becomes a wrapper calling event_command.reg().

It also removes the problematic call to event_command.unreg() in case
of failure. A new function, event_trigger_unregister() is also added
for callers to call themselves.

The changes to trace_events_hist.c simply allow compilation; a
separate patch follows which updates the hist triggers to work
correctly with the new changes.

Link: https://lkml.kernel.org/r/6149fec7a139d93e84fa4535672fb5bef88006b0.1644010575.git.zanussi@kernel.org

Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

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tracing: Uninline trace_trigger_soft_disabled() partly

On a powerpc32 build with CONFIG_CC_OPTIMISE_FOR_SIZE, the inline
keyword is not honored and trace_trigger_soft_disabled() appears
approx 50 ti

tracing: Uninline trace_trigger_soft_disabled() partly

On a powerpc32 build with CONFIG_CC_OPTIMISE_FOR_SIZE, the inline
keyword is not honored and trace_trigger_soft_disabled() appears
approx 50 times in vmlinux.

Adding -Winline to the build, the following message appears:

./include/linux/trace_events.h:712:1: error: inlining failed in call to 'trace_trigger_soft_disabled': call is unlikely and code size would grow [-Werror=inline]

That function is rather big for an inlined function:

c003df60 <trace_trigger_soft_disabled>:
c003df60: 94 21 ff f0 stwu r1,-16(r1)
c003df64: 7c 08 02 a6 mflr r0
c003df68: 90 01 00 14 stw r0,20(r1)
c003df6c: bf c1 00 08 stmw r30,8(r1)
c003df70: 83 e3 00 24 lwz r31,36(r3)
c003df74: 73 e9 01 00 andi. r9,r31,256
c003df78: 41 82 00 10 beq c003df88 <trace_trigger_soft_disabled+0x28>
c003df7c: 38 60 00 00 li r3,0
c003df80: 39 61 00 10 addi r11,r1,16
c003df84: 4b fd 60 ac b c0014030 <_rest32gpr_30_x>
c003df88: 73 e9 00 80 andi. r9,r31,128
c003df8c: 7c 7e 1b 78 mr r30,r3
c003df90: 41 a2 00 14 beq c003dfa4 <trace_trigger_soft_disabled+0x44>
c003df94: 38 c0 00 00 li r6,0
c003df98: 38 a0 00 00 li r5,0
c003df9c: 38 80 00 00 li r4,0
c003dfa0: 48 05 c5 f1 bl c009a590 <event_triggers_call>
c003dfa4: 73 e9 00 40 andi. r9,r31,64
c003dfa8: 40 82 00 28 bne c003dfd0 <trace_trigger_soft_disabled+0x70>
c003dfac: 73 ff 02 00 andi. r31,r31,512
c003dfb0: 41 82 ff cc beq c003df7c <trace_trigger_soft_disabled+0x1c>
c003dfb4: 80 01 00 14 lwz r0,20(r1)
c003dfb8: 83 e1 00 0c lwz r31,12(r1)
c003dfbc: 7f c3 f3 78 mr r3,r30
c003dfc0: 83 c1 00 08 lwz r30,8(r1)
c003dfc4: 7c 08 03 a6 mtlr r0
c003dfc8: 38 21 00 10 addi r1,r1,16
c003dfcc: 48 05 6f 6c b c0094f38 <trace_event_ignore_this_pid>
c003dfd0: 38 60 00 01 li r3,1
c003dfd4: 4b ff ff ac b c003df80 <trace_trigger_soft_disabled+0x20>

However it is located in a hot path so inlining it is important.
But forcing inlining of the entire function by using __always_inline
leads to increasing the text size by approx 20 kbytes.

Instead, split the fonction in two parts, one part with the likely
fast path, flagged __always_inline, and a second part out of line.

With this change, on a powerpc32 with CONFIG_CC_OPTIMISE_FOR_SIZE
vmlinux text increases by only 1,4 kbytes, which is partly
compensated by a decrease of vmlinux data by 7 kbytes.

On ppc64_defconfig which has CONFIG_CC_OPTIMISE_FOR_SPEED, this
change reduces vmlinux text by more than 30 kbytes.

Link: https://lkml.kernel.org/r/69ce0986a52d026d381d612801d978aa4f977460.1644563295.git.christophe.leroy@csgroup.eu

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

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tracing: Have traceon and traceoff trigger honor the instance

If a trigger is set on an event to disable or enable tracing within an
instance, then tracing should be disabled or enabled in the insta

tracing: Have traceon and traceoff trigger honor the instance

If a trigger is set on an event to disable or enable tracing within an
instance, then tracing should be disabled or enabled in the instance and
not at the top level, which is confusing to users.

Link: https://lkml.kernel.org/r/20220223223837.14f94ec3@rorschach.local.home

Cc: stable@vger.kernel.org
Fixes: ae63b31e4d0e2 ("tracing: Separate out trace events from global variables")
Tested-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

show more ...

tracing: Dump stacktrace trigger to the corresponding instance

The stacktrace event trigger is not dumping the stacktrace to the instance
where it was enabled, but to the global "instance."

Use the

tracing: Dump stacktrace trigger to the corresponding instance

The stacktrace event trigger is not dumping the stacktrace to the instance
where it was enabled, but to the global "instance."

Use the private_data, pointing to the trigger file, to figure out the
corresponding trace instance, and use it in the trigger action, like
snapshot_trigger does.

Link: https://lkml.kernel.org/r/afbb0b4f18ba92c276865bc97204d438473f4ebc.1645396236.git.bristot@kernel.org

Cc: stable@vger.kernel.org
Fixes: ae63b31e4d0e2 ("tracing: Separate out trace events from global variables")
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Tested-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

show more ...

tracing: Add helper functions to simplify event_command.parse() callback handling

The event_command.parse() callback is responsible for parsing and
registering triggers. The existing command implem

tracing: Add helper functions to simplify event_command.parse() callback handling

The event_command.parse() callback is responsible for parsing and
registering triggers. The existing command implementions for this
callback duplicate a lot of the same code, so to clean up and
consolidate those implementations, introduce a handful of helper
functions for implementors to use.

This also makes it easier for new commands to be implemented and
allows them to focus more on the customizations they provide rather
than obscuring and complicating it with boilerplate code.

Link: https://lkml.kernel.org/r/c1ff71f594d45177706571132bd3119491097221.1641823001.git.zanussi@kernel.org

Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

show more ...

tracing: Remove ops param from event_command reg()/unreg() callbacks

The event_trigger_ops for an event_command are already accessible via
event_trigger_data.ops so remove the redundant ops from the

tracing: Remove ops param from event_command reg()/unreg() callbacks

The event_trigger_ops for an event_command are already accessible via
event_trigger_data.ops so remove the redundant ops from the callback.

Link: https://lkml.kernel.org/r/4c6f2a41820452f9cacddc7634ad442928aa2aa6.1641823001.git.zanussi@kernel.org

Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

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tracing: Change event_trigger_ops func() to trigger()

The name of the func() callback on event_trigger_ops is too generic
and is easily confused with other callbacks with that name, so change
it to

tracing: Change event_trigger_ops func() to trigger()

The name of the func() callback on event_trigger_ops is too generic
and is easily confused with other callbacks with that name, so change
it to something that reflects its actual purpose.

In this case, the main purpose of the callback is to implement an
event trigger, so call it trigger() instead.

Also add some more documentation to event_trigger_ops describing the
callbacks a bit better.

Link: https://lkml.kernel.org/r/36ab812e3ee74ee03ae0043fda41a858ee728c00.1641823001.git.zanussi@kernel.org

Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

show more ...

tracing: Change event_command func() to parse()

The name of the func() callback on event_command is too generic and is
easily confused with other callbacks with that name, so change it to
something

tracing: Change event_command func() to parse()

The name of the func() callback on event_command is too generic and is
easily confused with other callbacks with that name, so change it to
something that reflects its actual purpose.

In this case, the main purpose of the callback is to parse an event
command, so call it parse() instead.

Link: https://lkml.kernel.org/r/7784e321840752ed88aac0b349c0c685fc9247b1.1641823001.git.zanussi@kernel.org

Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

show more ...

tracing: Fix to check event_mutex is held while accessing trigger list

commit cecf8e128ec69149fe53c9a7bafa505a4bee25d9 upstream.

Since the check_user_trigger() is called outside of RCU
read lock, t

tracing: Fix to check event_mutex is held while accessing trigger list

commit cecf8e128ec69149fe53c9a7bafa505a4bee25d9 upstream.

Since the check_user_trigger() is called outside of RCU
read lock, this list_for_each_entry_rcu() caused a suspicious
RCU usage warning.

# echo hist:keys=pid > events/sched/sched_stat_runtime/trigger
# cat events/sched/sched_stat_runtime/trigger
[ 43.167032]
[ 43.167418] =============================
[ 43.167992] WARNING: suspicious RCU usage
[ 43.168567] 5.19.0-rc5-00029-g19ebe4651abf #59 Not tainted
[ 43.169283] -----------------------------
[ 43.169863] kernel/trace/trace_events_trigger.c:145 RCU-list traversed in non-reader section!!
...

However, this file->triggers list is safe when it is accessed
under event_mutex is held.
To fix this warning, adds a lockdep_is_held check to the
list_for_each_entry_rcu().

Link: https://lkml.kernel.org/r/166226474977.223837.1992182913048377113.stgit@devnote2

Cc: stable@vger.kernel.org
Fixes: 7491e2c44278 ("tracing: Add a probe that attaches to trace events")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

tracing: Have traceon and traceoff trigger honor the instance

commit 302e9edd54985f584cfc180098f3554774126969 upstream.

If a trigger is set on an event to disable or enable tracing within an
instan

tracing: Have traceon and traceoff trigger honor the instance

commit 302e9edd54985f584cfc180098f3554774126969 upstream.

If a trigger is set on an event to disable or enable tracing within an
instance, then tracing should be disabled or enabled in the instance and
not at the top level, which is confusing to users.

Link: https://lkml.kernel.org/r/20220223223837.14f94ec3@rorschach.local.home

Cc: stable@vger.kernel.org
Fixes: ae63b31e4d0e2 ("tracing: Separate out trace events from global variables")
Tested-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

tracing: Dump stacktrace trigger to the corresponding instance

commit ce33c845b030c9cf768370c951bc699470b09fa7 upstream.

The stacktrace event trigger is not dumping the stacktrace to the instance
w

tracing: Dump stacktrace trigger to the corresponding instance

commit ce33c845b030c9cf768370c951bc699470b09fa7 upstream.

The stacktrace event trigger is not dumping the stacktrace to the instance
where it was enabled, but to the global "instance."

Use the private_data, pointing to the trigger file, to figure out the
corresponding trace instance, and use it in the trigger action, like
snapshot_trigger does.

Link: https://lkml.kernel.org/r/afbb0b4f18ba92c276865bc97204d438473f4ebc.1645396236.git.bristot@kernel.org

Cc: stable@vger.kernel.org
Fixes: ae63b31e4d0e2 ("tracing: Separate out trace events from global variables")
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Tested-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

tracing: Add a probe that attaches to trace events

A new dynamic event is introduced: event probe. The event is attached
to an existing tracepoint and uses its fields as arguments. The user
can spec

tracing: Add a probe that attaches to trace events

A new dynamic event is introduced: event probe. The event is attached
to an existing tracepoint and uses its fields as arguments. The user
can specify custom format string of the new event, select what tracepoint
arguments will be printed and how to print them.
An event probe is created by writing configuration string in
'dynamic_events' ftrace file:
e[:[SNAME/]ENAME] SYSTEM/EVENT [FETCHARGS] - Set an event probe
-:SNAME/ENAME - Delete an event probe

Where:
SNAME - System name, if omitted 'eprobes' is used.
ENAME - Name of the new event in SNAME, if omitted the SYSTEM_EVENT is used.
SYSTEM - Name of the system, where the tracepoint is defined, mandatory.
EVENT - Name of the tracepoint event in SYSTEM, mandatory.
FETCHARGS - Arguments:
<name>=$<field>[:TYPE] - Fetch given filed of the tracepoint and print
it as given TYPE with given name. Supported
types are:
(u8/u16/u32/u64/s8/s16/s32/s64), basic type
(x8/x16/x32/x64), hexadecimal types
"string", "ustring" and bitfield.

Example, attach an event probe on openat system call and print name of the
file that will be opened:
echo "e:esys/eopen syscalls/sys_enter_openat file=\$filename:string" >> dynamic_events
A new dynamic event is created in events/esys/eopen/ directory. It
can be deleted with:
echo "-:esys/eopen" >> dynamic_events

Filters, triggers and histograms can be attached to the new event, it can
be matched in synthetic events. There is one limitation - an event probe
can not be attached to kprobe, uprobe or another event probe.

Link: https://lkml.kernel.org/r/20210812145805.2292326-1-tz.stoyanov@gmail.com
Link: https://lkml.kernel.org/r/20210819152825.142428383@goodmis.org

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Co-developed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

show more ...

tracing: Have dynamic events have a ref counter

As dynamic events are not created by modules, if something is attached to
one, calling "try_module_get()" on its "mod" field, is not going to keep
the

tracing: Have dynamic events have a ref counter

As dynamic events are not created by modules, if something is attached to
one, calling "try_module_get()" on its "mod" field, is not going to keep
the dynamic event from going away.

Since dynamic events do not need the "mod" pointer of the event structure,
make a union out of it in order to save memory (there's one structure for
each of the thousand+ events in the kernel), and have any event with the
DYNAMIC flag set to use a ref counter instead.

Link: https://lore.kernel.org/linux-trace-devel/20210813004448.51c7de69ce432d338f4d226b@kernel.org/
Link: https://lkml.kernel.org/r/20210817035027.174869074@goodmis.org

Suggested-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

show more ...

tracing: Fix set_named_trigger_data() kernel-doc comment

Fix the description of the parameters.

Link: https://lkml.kernel.org/r/20210515105735.52785-1-hqjagain@gmail.com

Signed-off-by: Qiujun Huan

tracing: Fix set_named_trigger_data() kernel-doc comment

Fix the description of the parameters.

Link: https://lkml.kernel.org/r/20210515105735.52785-1-hqjagain@gmail.com

Signed-off-by: Qiujun Huang <hqjagain@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

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tracing: Pass buffer of event to trigger operations

The ring_buffer_event_time_stamp() is going to be updated to extract the
time stamp for the event without needing it to be set to have absolute
va

tracing: Pass buffer of event to trigger operations

The ring_buffer_event_time_stamp() is going to be updated to extract the
time stamp for the event without needing it to be set to have absolute
values for all events. But to do so, it needs the buffer that the event is
on as the buffer saves information for the event before it is committed to
the buffer.

If the trace buffer is disabled, a temporary buffer is used, and there's
no access to this buffer from the current histogram triggers, even though
it is passed to the trace event code.

Pass the buffer that the event is on all the way down to the histogram
triggers.

Link: https://lkml.kernel.org/r/20210316164113.542448131@goodmis.org

Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

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tracing: Fix event trigger to accept redundant spaces

Fix the event trigger to accept redundant spaces in
the trigger input.

For example, these return -EINVAL

echo " traceon" > events/ftrace/print

tracing: Fix event trigger to accept redundant spaces

Fix the event trigger to accept redundant spaces in
the trigger input.

For example, these return -EINVAL

echo " traceon" > events/ftrace/print/trigger
echo "traceon if common_pid == 0" > events/ftrace/print/trigger
echo "disable_event:kmem:kmalloc " > events/ftrace/print/trigger

But these are hard to find what is wrong.

To fix this issue, use skip_spaces() to remove spaces
in front of actual tokens, and set NULL if there is no
token.

Link: http://lkml.kernel.org/r/159262476352.185015.5261566783045364186.stgit@devnote2

Cc: Tom Zanussi <zanussi@kernel.org>
Cc: stable@vger.kernel.org
Fixes: 85f2b08268c0 ("tracing: Add basic event trigger framework")
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

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