[PATCH 3/5] tools/bootconfig: Ignore filter strings when resolving histogram variables

[Eduardo Mucelli Rezende Oliveira <edumucelli@gmail.com>]

The histogram variable resolver scans the entire trigger line, including
its filter. A literal string such as "$not_a_variable" is consequently
read as a variable reference and the histogram is deferred and omitted.
Conversely, a filter containing ":dep0=" looks like a definition and can
cause a consumer to be exported before its real provider.

Remove the filter portion before looking for variable definitions and
references. Leave the complete filter intact when exporting the action.

Fixes: 2b86062a34a8 ("tools/bootconfig: Add a script to generates bootconfig from ftrace")
Signed-off-by: Eduardo Mucelli Rezende Oliveira <edumucelli@gmail.com>
---
I tested literal dollar signs and assignment-looking strings in
histogram filters in a temporary tracefs instance on my Ubuntu machine,
running kernel 7.0.0-38-generic, with recording disabled.

The original exporter omitted the dollar-sign cases and treated text
inside another filter as a provider, putting a consumer first. With
the fix, the literal filters were retained and the real provider was
exported before its consumer.

 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 77ec17c94a17..8ba1a698611e 100755
--- a/tools/bootconfig/scripts/ftrace2bconf.sh
+++ b/tools/bootconfig/scripts/ftrace2bconf.sh
@@ -86,10 +86,10 @@ synth_event_options() {
 # Variables resolver
 
 defined_vars() { # event-dir
-	grep "^hist" $1/trigger | grep -o ':[a-zA-Z0-9_]*='
+	grep "^hist" $1/trigger | sed 's/ if .*//' | grep -o ':[a-zA-Z0-9_]*='
 }
 referred_vars() {
-	grep "^hist" $1/trigger | grep -o '$[a-zA-Z0-9_]*'
+	grep "^hist" $1/trigger | sed 's/ if .*//' | grep -o '$[a-zA-Z0-9_]*'
 }
 
 event_is_enabled() { # enable-file
-- 
2.53.0