[PATCH 0/4] tools/bootconfig: Preserve tracing settings during export

[PATCH 0/4] tools/bootconfig: Preserve tracing settings during export

[Eduardo Mucelli Rezende Oliveira]

Hi Masami,

Here are four more fixes for ftrace2bconf.sh, based on bootconfig/fixes.
They address settings that change or fail to restore after export:

- Event filters containing punctuation are quoted as one bootconfig value.
- Generic trigger counts are written in the syntax accepted by tracefs.
- Histogram variable tracking starts fresh for each tracing instance.
- Paused histograms keep their paused state when restored.

The base includes the trigger-filter and underscore fixes you picked up.
The new sed expression also uses POSIX syntax, following your feedback.

I tested each fix and the full series in temporary tracefs instances on
my Ubuntu machine, running kernel 7.0.0-38-generic, with recording
disabled. The patch emails include the individual reproduction details.
The fixture checks also cover each step of the series.

Feedback is welcome.

Thanks,
Eduardo

Eduardo Mucelli Rezende Oliveira (4):
  tools/bootconfig: Quote event filters in ftrace2bconf.sh
  tools/bootconfig: Export replayable event trigger counts
  tools/bootconfig: Reset histogram variable tracking for each instance
  tools/bootconfig: Preserve paused histograms in ftrace2bconf.sh

 tools/bootconfig/scripts/ftrace2bconf.sh | 24 +++++++++++++++++++++---
 1 file changed, 21 insertions(+), 3 deletions(-)


base-commit: 1dc6d173c43e10a1d0ee36b43d0d2f371f4d262a
-- 
2.53.0

[PATCH 1/4] tools/bootconfig: Quote event filters in ftrace2bconf.sh

[Eduardo Mucelli Rezende Oliveira]

ftrace2bconf.sh emits event filters without enclosing bootconfig quotes.
A filter such as prev_comm == "a,b" is therefore parsed as an array,
while a # truncates the value and a semicolon or closing brace can make
the exported configuration invalid.

Quote filters containing bootconfig delimiters so that the complete
expression remains one value. Choose the enclosing quote in the same
way as the bootconfig utility. Leave filters without delimiters as they
are, including expressions that contain both kinds of quote.

Fixes: 2b86062a34a8 ("tools/bootconfig: Add a script to generates bootconfig from ftrace")
Signed-off-by: Eduardo Mucelli Rezende Oliveira <edumucelli@gmail.com>
---
I tested event filters containing a comma, semicolon, # and closing
brace in a temporary tracefs instance on my Ubuntu machine, running
kernel 7.0.0-38-generic, with recording disabled.

The original export split or truncated these filters, or produced a
config that could not be parsed. With the fix, each expression remained
one value and was restored unchanged. A filter containing an ordinary
space worked in both versions.

 tools/bootconfig/scripts/ftrace2bconf.sh | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/tools/bootconfig/scripts/ftrace2bconf.sh b/tools/bootconfig/scripts/ftrace2bconf.sh
index b01297217cf3..8c5889d0420c 100755
--- a/tools/bootconfig/scripts/ftrace2bconf.sh
+++ b/tools/bootconfig/scripts/ftrace2bconf.sh
@@ -126,6 +126,14 @@ per_event_options() { # event-dir
 	fi
 	val=`cat $evdir/filter`
 	if [ "$val" != "none" ]; then
+		case "$val" in
+		*[',;#}']*)
+			case "$val" in
+			*\"*) val="'$val'";;
+			*) val="\"$val\"";;
+			esac
+			;;
+		esac
 		emit_kv $PREFIX.event.$group.$event.filter = "$val"
 	fi
 }
-- 
2.53.0

[PATCH 2/4] tools/bootconfig: Export replayable event trigger counts

[Eduardo Mucelli Rezende Oliveira]

Tracefs displays generic event trigger counts as :unlimited or :count=N.
ftrace2bconf.sh copies these annotations into the exported action, but
the trigger input syntax requires an omitted count or :N. Replaying an
exported traceoff or enable_event action therefore fails.

Remove :unlimited and convert :count=N to :N in the command token before
emitting the action. Keep the filter text unchanged and leave histogram
commands alone, where count can be a variable name.

Fixes: 2b86062a34a8 ("tools/bootconfig: Add a script to generates bootconfig from ftrace")
Signed-off-by: Eduardo Mucelli Rezende Oliveira <edumucelli@gmail.com>
---
I tested traceoff with an unlimited count, traceoff:7 with a filter,
and enable_event with a finite count and filter in a temporary tracefs
instance on my Ubuntu machine, running kernel 7.0.0-38-generic, with
recording disabled.

The original exported count annotations were rejected during replay.
With the fix, the triggers and their filters were restored correctly.
A histogram defining a variable named count also worked unchanged.

 tools/bootconfig/scripts/ftrace2bconf.sh | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/tools/bootconfig/scripts/ftrace2bconf.sh b/tools/bootconfig/scripts/ftrace2bconf.sh
index 8c5889d0420c..82c4fe021fb7 100755
--- a/tools/bootconfig/scripts/ftrace2bconf.sh
+++ b/tools/bootconfig/scripts/ftrace2bconf.sh
@@ -118,6 +118,15 @@ per_event_options() { # event-dir
 	grep -v "^#" $evdir/trigger |
 		sed -e 's/ \[active\]$//' -e 's/ \[paused\]$//' |
 		while IFS= read -r action; do
+		action_cmd=${action%% *}
+		action_rest=${action#"$action_cmd"}
+		case "$action_cmd" in
+		hist:*) ;;
+		*:unlimited)
+			action="${action_cmd%:unlimited}$action_rest";;
+		*:count=*)
+			action="${action_cmd%:count=*}:${action_cmd##*:count=}$action_rest";;
+		esac
 		emit_kv $PREFIX.event.$group.$event.actions += "'$action'"
 	done
 
-- 
2.53.0

[PATCH 3/4] tools/bootconfig: Reset histogram variable tracking for each instance

[Eduardo Mucelli Rezende Oliveira]

Histogram variables are scoped to a trace instance, but ftrace2bconf.sh
keeps DEFINED_VARS across calls to event_options(). If an earlier instance
has defined ts0, a later instance can export a consumer of its own ts0
before exporting that instance's provider. Replaying the configuration
then fails because the local variable has not been defined yet.

Initialize the variable resolver state when starting each instance so
that its consumers are deferred until their local providers are exported.

Fixes: 2b86062a34a8 ("tools/bootconfig: Add a script to generates bootconfig from ftrace")
Signed-off-by: Eduardo Mucelli Rezende Oliveira <edumucelli@gmail.com>
---
I reproduced this with two temporary tracefs instances on my Ubuntu
machine, running kernel 7.0.0-38-generic, with recording disabled. Both
instances defined a histogram variable with the same name. In the second
instance, a consumer sorted before its local provider.

The original exporter put that consumer first and replay failed with an
undefined variable. With the fix, the local provider was exported first
and all three histograms were restored correctly.

 tools/bootconfig/scripts/ftrace2bconf.sh | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/bootconfig/scripts/ftrace2bconf.sh b/tools/bootconfig/scripts/ftrace2bconf.sh
index 82c4fe021fb7..6d36219eb997 100755
--- a/tools/bootconfig/scripts/ftrace2bconf.sh
+++ b/tools/bootconfig/scripts/ftrace2bconf.sh
@@ -84,8 +84,6 @@ synth_event_options() {
 }
 
 # Variables resolver
-DEFINED_VARS=
-UNRESOLVED_EVENTS=
 
 defined_vars() { # event-dir
 	grep "^hist" $1/trigger | grep -o ':[a-zA-Z0-9_]*='
@@ -159,6 +157,8 @@ retry_unresolved() {
 
 event_options() {
 	# PREFIX and INSTANCE must be set
+	DEFINED_VARS=
+	UNRESOLVED_EVENTS=
 	if [ $PREFIX = "ftrace" ]; then
 		# define the dynamic events
 		kprobe_event_options
-- 
2.53.0

[PATCH 4/4] tools/bootconfig: Preserve paused histograms in ftrace2bconf.sh

[Eduardo Mucelli Rezende Oliveira]

The trigger file reports a paused histogram with a trailing [paused]
annotation. Removing that annotation without adding a pause parameter
exports the histogram as an active trigger. Replaying the exported
configuration therefore enables aggregation that was previously paused.

Add the pause parameter after the hist prefix before removing the display
annotation. This keeps the parameter before any filter expression and
preserves both the paused state and the filter.

Fixes: 2b86062a34a8 ("tools/bootconfig: Add a script to generates bootconfig from ftrace")
Signed-off-by: Eduardo Mucelli Rezende Oliveira <edumucelli@gmail.com>
---
I tested paused histograms with and without a filter, plus an active
histogram, in a temporary tracefs instance on my Ubuntu machine, running
kernel 7.0.0-38-generic, with recording disabled.

The original exporter restored the paused histograms as active. With
the fix, both paused histograms kept their state and filters, and the
active histogram still restored as active. One filter contained the
literal string [paused], which was preserved as well.

 tools/bootconfig/scripts/ftrace2bconf.sh | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/bootconfig/scripts/ftrace2bconf.sh b/tools/bootconfig/scripts/ftrace2bconf.sh
index 6d36219eb997..93879181dab9 100755
--- a/tools/bootconfig/scripts/ftrace2bconf.sh
+++ b/tools/bootconfig/scripts/ftrace2bconf.sh
@@ -114,7 +114,8 @@ per_event_options() { # event-dir
 		DEFINED_VARS="$DEFINED_VARS "`defined_vars $evdir`
 	fi
 	grep -v "^#" $evdir/trigger |
-		sed -e 's/ \[active\]$//' -e 's/ \[paused\]$//' |
+		sed -e '/^hist:.* \[paused\]$/s/^hist:/hist:pause:/' \
+			-e 's/ \[active\]$//' -e 's/ \[paused\]$//' |
 		while IFS= read -r action; do
 		action_cmd=${action%% *}
 		action_rest=${action#"$action_cmd"}
-- 
2.53.0

Re: [PATCH 1/4] tools/bootconfig: Quote event filters in ftrace2bconf.sh

[Masami Hiramatsu (Google)]

Hi Eduardo,

On Fri, 30 Oct 2026 13:51:48 +0100, Eduardo Mucelli Rezende Oliveira <edumucelli@gmail.com> wrote:

> diff --git a/tools/bootconfig/scripts/ftrace2bconf.sh b/tools/bootconfig/scripts/ftrace2bconf.sh
> --- a/tools/bootconfig/scripts/ftrace2bconf.sh
> +++ b/tools/bootconfig/scripts/ftrace2bconf.sh
> @@ -126,6 +126,14 @@ per_event_options() { # event-dir
>  	val=`cat $evdir/filter`
>  	if [ "$val" != "none" ]; then
> +		case "$val" in
> +		*[',;#}']*)

This expression is a bit complicated. Could you explictly escape the "#" and "}"
as "*[,;\#\}]*" ?

> +			case "$val" in
> +			*\"*) val="'$val'";;

If an event filter contains delimiters alongside both double and single quotes 
(e.g. `prev_comm == "a,b" && next_comm == 'c'`), matching `*\"*` unconditionally
encloses `$val` in single quotes `'...'`. Because the value itself already contains
single quotes, this produces an unescaped single quote that will break bootconfig
parsing at boot time ("No value delimiter" / "No closing quotes").

Since bootconfig does not support escape sequences, such filters cannot be
represented when delimiters are present. Rather than outputting malformed
bootconfig, please detect expressions containing both quote types
(`*\"*\'*|*\'*\"*`) when delimiters are matched and emit a warning to stderr
(`# WARN: ...`) similar to other unsupported ftrace options in this script.

Thank you,


> +			*) val="\"$val\"";;
> +			esac
> +			;;

-- 
Masami Hiramatsu (Google) <mhiramat@kernel.org>

[PATCH v2 0/4] tools/bootconfig: Preserve tracing settings during export

[Eduardo Mucelli Rezende Oliveira]

Hi Masami,

Thanks for the review. I've updated the event-filter patch to use the
explicit delimiter pattern you suggested. It now warns and skips filters
that contain delimiters and both quote types, since bootconfig cannot
represent them. The other three patches are unchanged.

Changes in v2:
- Patch 1: use explicit escapes in *[,\;\#\}]* for the delimiter check.
  The semicolon also needs escaping for the shell to parse the pattern.
- Patch 1: detect both quote types, warn on stderr and skip the filter.
- Patches 2-4: no changes.

The series keeps event filters, generic trigger counts, histogram
variable ordering and paused histogram state during export. It is still
based on bootconfig/fixes, including the two fixes you picked up earlier.

I retested the filter change in a temporary tracefs instance on my Ubuntu
machine, running kernel 7.0.0-38-generic, with recording disabled. I also
checked the mixed-quote cases against real tracefs filters and added
regression checks for both quote orders and all four delimiters. The
fixture checks cover each fix and the full series.

Feedback is welcome.

Thanks,
Eduardo

Eduardo Mucelli Rezende Oliveira (4):
  tools/bootconfig: Quote event filters in ftrace2bconf.sh
  tools/bootconfig: Export replayable event trigger counts
  tools/bootconfig: Reset histogram variable tracking for each instance
  tools/bootconfig: Preserve paused histograms in ftrace2bconf.sh

 tools/bootconfig/scripts/ftrace2bconf.sh | 29 +++++++++++++++++++++---
 1 file changed, 26 insertions(+), 3 deletions(-)


base-commit: 1dc6d173c43e10a1d0ee36b43d0d2f371f4d262a
-- 
2.53.0

[PATCH v2 1/4] tools/bootconfig: Quote event filters in ftrace2bconf.sh

[Eduardo Mucelli Rezende Oliveira]

ftrace2bconf.sh emits event filters without enclosing bootconfig quotes.
A filter such as prev_comm == "a,b" is therefore parsed as an array,
while a # truncates the value and a semicolon or closing brace can make
the exported configuration invalid.

Quote filters containing bootconfig delimiters so that the complete
expression remains one value. Choose an enclosing quote that does
not occur in the expression. When both quote types occur alongside a
delimiter, bootconfig cannot represent the filter because it does not
support escape sequences. Warn and skip that filter instead of emitting
invalid bootconfig. Leave filters without delimiters unchanged.

Fixes: 2b86062a34a8 ("tools/bootconfig: Add a script to generates bootconfig from ftrace")
Signed-off-by: Eduardo Mucelli Rezende Oliveira <edumucelli@gmail.com>
---
I tested event filters containing a comma, semicolon, # and closing
brace in a temporary tracefs instance on my Ubuntu machine, running
kernel 7.0.0-38-generic, with recording disabled.

The original export split or truncated these filters, or produced a
config that could not be parsed. With the fix, each expression remained
one value and was restored unchanged. A filter containing an ordinary
space worked in both versions.

I also checked the mixed-quote cases from your review. These now produce
a warning and are skipped, while filters without delimiters still export.

 tools/bootconfig/scripts/ftrace2bconf.sh | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/tools/bootconfig/scripts/ftrace2bconf.sh b/tools/bootconfig/scripts/ftrace2bconf.sh
index b01297217cf3..8f3edea79ca0 100755
--- a/tools/bootconfig/scripts/ftrace2bconf.sh
+++ b/tools/bootconfig/scripts/ftrace2bconf.sh
@@ -126,6 +126,19 @@ per_event_options() { # event-dir
 	fi
 	val=`cat $evdir/filter`
 	if [ "$val" != "none" ]; then
+		case "$val" in
+		*[,\;\#\}]*)
+			case "$val" in
+			*\"*\'*|*\'*\"*)
+				cat 1>&2 << EOF
+# WARN: $PREFIX.event.$group.$event.filter cannot be quoted for bootconfig. Skip it.
+EOF
+				return;;
+			*\"*) val="'$val'";;
+			*) val="\"$val\"";;
+			esac
+			;;
+		esac
 		emit_kv $PREFIX.event.$group.$event.filter = "$val"
 	fi
 }
-- 
2.53.0

[PATCH v2 2/4] tools/bootconfig: Export replayable event trigger counts

[Eduardo Mucelli Rezende Oliveira]

Tracefs displays generic event trigger counts as :unlimited or :count=N.
ftrace2bconf.sh copies these annotations into the exported action, but
the trigger input syntax requires an omitted count or :N. Replaying an
exported traceoff or enable_event action therefore fails.

Remove :unlimited and convert :count=N to :N in the command token before
emitting the action. Keep the filter text unchanged and leave histogram
commands alone, where count can be a variable name.

Fixes: 2b86062a34a8 ("tools/bootconfig: Add a script to generates bootconfig from ftrace")
Signed-off-by: Eduardo Mucelli Rezende Oliveira <edumucelli@gmail.com>
---
I tested traceoff with an unlimited count, traceoff:7 with a filter,
and enable_event with a finite count and filter in a temporary tracefs
instance on my Ubuntu machine, running kernel 7.0.0-38-generic, with
recording disabled.

The original exported count annotations were rejected during replay.
With the fix, the triggers and their filters were restored correctly.
A histogram defining a variable named count also worked unchanged.

 tools/bootconfig/scripts/ftrace2bconf.sh | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/tools/bootconfig/scripts/ftrace2bconf.sh b/tools/bootconfig/scripts/ftrace2bconf.sh
index 8f3edea79ca0..9100ebcd5af6 100755
--- a/tools/bootconfig/scripts/ftrace2bconf.sh
+++ b/tools/bootconfig/scripts/ftrace2bconf.sh
@@ -118,6 +118,15 @@ per_event_options() { # event-dir
 	grep -v "^#" $evdir/trigger |
 		sed -e 's/ \[active\]$//' -e 's/ \[paused\]$//' |
 		while IFS= read -r action; do
+		action_cmd=${action%% *}
+		action_rest=${action#"$action_cmd"}
+		case "$action_cmd" in
+		hist:*) ;;
+		*:unlimited)
+			action="${action_cmd%:unlimited}$action_rest";;
+		*:count=*)
+			action="${action_cmd%:count=*}:${action_cmd##*:count=}$action_rest";;
+		esac
 		emit_kv $PREFIX.event.$group.$event.actions += "'$action'"
 	done
 
-- 
2.53.0

[PATCH v2 3/4] tools/bootconfig: Reset histogram variable tracking for each instance

[Eduardo Mucelli Rezende Oliveira]

Histogram variables are scoped to a trace instance, but ftrace2bconf.sh
keeps DEFINED_VARS across calls to event_options(). If an earlier instance
has defined ts0, a later instance can export a consumer of its own ts0
before exporting that instance's provider. Replaying the configuration
then fails because the local variable has not been defined yet.

Initialize the variable resolver state when starting each instance so
that its consumers are deferred until their local providers are exported.

Fixes: 2b86062a34a8 ("tools/bootconfig: Add a script to generates bootconfig from ftrace")
Signed-off-by: Eduardo Mucelli Rezende Oliveira <edumucelli@gmail.com>
---
I reproduced this with two temporary tracefs instances on my Ubuntu
machine, running kernel 7.0.0-38-generic, with recording disabled. Both
instances defined a histogram variable with the same name. In the second
instance, a consumer sorted before its local provider.

The original exporter put that consumer first and replay failed with an
undefined variable. With the fix, the local provider was exported first
and all three histograms were restored correctly.

 tools/bootconfig/scripts/ftrace2bconf.sh | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/bootconfig/scripts/ftrace2bconf.sh b/tools/bootconfig/scripts/ftrace2bconf.sh
index 9100ebcd5af6..b63e04bf9400 100755
--- a/tools/bootconfig/scripts/ftrace2bconf.sh
+++ b/tools/bootconfig/scripts/ftrace2bconf.sh
@@ -84,8 +84,6 @@ synth_event_options() {
 }
 
 # Variables resolver
-DEFINED_VARS=
-UNRESOLVED_EVENTS=
 
 defined_vars() { # event-dir
 	grep "^hist" $1/trigger | grep -o ':[a-zA-Z0-9_]*='
@@ -164,6 +162,8 @@ retry_unresolved() {
 
 event_options() {
 	# PREFIX and INSTANCE must be set
+	DEFINED_VARS=
+	UNRESOLVED_EVENTS=
 	if [ $PREFIX = "ftrace" ]; then
 		# define the dynamic events
 		kprobe_event_options
-- 
2.53.0

[PATCH v2 4/4] tools/bootconfig: Preserve paused histograms in ftrace2bconf.sh

[Eduardo Mucelli Rezende Oliveira]

The trigger file reports a paused histogram with a trailing [paused]
annotation. Removing that annotation without adding a pause parameter
exports the histogram as an active trigger. Replaying the exported
configuration therefore enables aggregation that was previously paused.

Add the pause parameter after the hist prefix before removing the display
annotation. This keeps the parameter before any filter expression and
preserves both the paused state and the filter.

Fixes: 2b86062a34a8 ("tools/bootconfig: Add a script to generates bootconfig from ftrace")
Signed-off-by: Eduardo Mucelli Rezende Oliveira <edumucelli@gmail.com>
---
I tested paused histograms with and without a filter, plus an active
histogram, in a temporary tracefs instance on my Ubuntu machine, running
kernel 7.0.0-38-generic, with recording disabled.

The original exporter restored the paused histograms as active. With
the fix, both paused histograms kept their state and filters, and the
active histogram still restored as active. One filter contained the
literal string [paused], which was preserved as well.

 tools/bootconfig/scripts/ftrace2bconf.sh | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/bootconfig/scripts/ftrace2bconf.sh b/tools/bootconfig/scripts/ftrace2bconf.sh
index b63e04bf9400..31702be0c68d 100755
--- a/tools/bootconfig/scripts/ftrace2bconf.sh
+++ b/tools/bootconfig/scripts/ftrace2bconf.sh
@@ -114,7 +114,8 @@ per_event_options() { # event-dir
 		DEFINED_VARS="$DEFINED_VARS "`defined_vars $evdir`
 	fi
 	grep -v "^#" $evdir/trigger |
-		sed -e 's/ \[active\]$//' -e 's/ \[paused\]$//' |
+		sed -e '/^hist:.* \[paused\]$/s/^hist:/hist:pause:/' \
+			-e 's/ \[active\]$//' -e 's/ \[paused\]$//' |
 		while IFS= read -r action; do
 		action_cmd=${action%% *}
 		action_rest=${action#"$action_cmd"}
-- 
2.53.0