[PATCH] perf test: probe_vfs_getname add do_getname() probing fallback

[Thomas Richter]

The following tests are skipped for some time now on platforms
s390 and x86_64:

 # perf test vfs_getname
 138: Add vfs_getname probe to get syscall args filenames    : Skip
 140: Use vfs_getname probe to get syscall args filenames    : Skip
 154: Check open filename arg using perf trace + vfs_getname : Skip
 #

This is caused by a change in kernel code of function
getname_flags(), see
  commit 9fa3ec84587c ("allow incomplete imports of filenames")
This commit changed the function getname_flags() implementation.

Now the perf probe 'vfs_getname parameter=xxx' does not match any
more. Extend the test logic to fall back to probing do_getname().
This reflects the updated kernel code.

Output after:
 # perf test vfs_getname
 138: Add vfs_getname probe to get syscall args filenames    : Ok
 140: Use vfs_getname probe to get syscall args filenames    : Ok
 154: Check open filename arg using perf trace + vfs_getname : Ok
 #

Signed-off-by: Thomas Richter <tmricht@xxxxxxxxxxxxx>
Reviewed-by: Sumanth Korikkar <sumanthk@xxxxxxxxxxxxx>
---
 tools/perf/tests/shell/lib/probe_vfs_getname.sh | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/tools/perf/tests/shell/lib/probe_vfs_getname.sh b/tools/perf/tests/shell/lib/probe_vfs_getname.sh
index 88cd0e26d5f6..9156a79212b9 100644
--- a/tools/perf/tests/shell/lib/probe_vfs_getname.sh
+++ b/tools/perf/tests/shell/lib/probe_vfs_getname.sh
@@ -12,6 +12,8 @@ cleanup_probe_vfs_getname() {
 
 add_probe_vfs_getname() {
 	add_probe_verbose=$1
+	do_getname=0
+
 	if [ $had_vfs_getname -eq 1 ] ; then
 		result_initname_re="[[:space:]]+([[:digit:]]+)[[:space:]]+initname.*"
 		line=$(perf probe -L getname_flags 2>&1 | grep -E "$result_initname_re" | sed -r "s/$result_initname_re/\1/")
@@ -28,12 +30,24 @@ add_probe_vfs_getname() {
 			line=$(perf probe -L getname_flags 2>&1 | grep -E "$result_aname_re" | sed -r "s/$result_aname_re/\1/")
 		fi
 
+		if [ -z "$line" ] ; then
+			do_getname=1
+			result_iname_re="[[:space:]]+([[:digit:]]+)[[:space:]]+initname\(result\);"
+			line=$(perf probe -L do_getname 2>&1 | grep -E "$result_iname_re" | sed -r "s/$result_iname_re/\1/")
+		fi
+
 		if [ -z "$line" ] ; then
 			echo "Could not find probeable line"
 			return 2
 		fi
 
-		perf probe -q       "vfs_getname=getname_flags:${line} pathname=result->name:string" || \
+		if [ "$do_getname" -eq 1 ]
+		then
+			param="vfs_getname=do_getname:${line} pathname=result->iname:string"
+			perf probe -q "$param" || perf probe $add_probe_verbose "$param" || return 1
+			return 0
+		fi
+		perf probe -q "vfs_getname=getname_flags:${line} pathname=result->name:string" || \
 		perf probe $add_probe_verbose "vfs_getname=getname_flags:${line} pathname=filename:ustring" || return 1
 	fi
 }
-- 
2.53.0