perf test probe_vfs_getname: Add regex for searching probe line

Since commit 6118510 ("fs: dedup handling of struct filename
init and refcounts bumps"), the kernel has been refactored to use a new
inline function initname(), moving name initialization into it.

As a result, the perf probe test can no longer find the source line that
matches the defined regular expressions. This causes the script to fail
when attempting to add probes.

Add a regular expression to search for the call site of initname(). This
provides a valid source line number for adding the probe. Keeps the
older regular expressions for passing test on older kernels.

Fixes: 6118510 ("fs: dedup handling of struct filename init and refcounts bumps")
Suggested-by: Arnaldo Carvalho de Melo <[email protected]>
Signed-off-by: Leo Yan <[email protected]>
Tested-by: Arnaldo Carvalho de Melo <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: Ian Rogers <[email protected]>
Cc: Jakub Brnak <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Kan Liang <[email protected]>
Cc: Mateusz Guzik <[email protected]>
Cc: Namhyung Kim <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

Author: Leo-Yan

tools/perf/tests/shell/lib/probe_vfs_getname.sh

@@ -13,8 +13,16 @@ cleanup_probe_vfs_getname() {
 add_probe_vfs_getname() {
 	add_probe_verbose=$1
 	if [ $had_vfs_getname -eq 1 ] ; then
-		result_filename_re="[[:space:]]+([[:digit:]]+)[[:space:]]+result->uptr.*"
-		line=$(perf probe -L getname_flags 2>&1 | grep -E "$result_filename_re" | sed -r "s/$result_filename_re/\1/")
+		result_initname_re="[[:space:]]+([[:digit:]]+)[[:space:]]+initname.*"
+		line=$(perf probe -L getname_flags 2>&1 | grep -E "$result_initname_re" | sed -r "s/$result_initname_re/\1/")
+
+		# Search the old regular expressions so that this will
+		# pass on older kernels as well.
+		if [ -z "$line" ] ; then
+			result_filename_re="[[:space:]]+([[:digit:]]+)[[:space:]]+result->uptr.*"
+			line=$(perf probe -L getname_flags 2>&1 | grep -E "$result_filename_re" | sed -r "s/$result_filename_re/\1/")
+		fi
+
 		if [ -z "$line" ] ; then
 			result_aname_re="[[:space:]]+([[:digit:]]+)[[:space:]]+result->aname = NULL;"
 			line=$(perf probe -L getname_flags 2>&1 | grep -E "$result_aname_re" | sed -r "s/$result_aname_re/\1/")