[PATCH v3] perf test probe_vfs_getname: Skip if no suitable line detected

[Jakub Brnak <jbrnak@redhat.com>]

In some cases when calling function add_probe_vfs_getname, line number
can't be detected by perf probe -L getname_flags:

  78         atomic_set(&result->refcnt, 1);

	     // one of the following lines should have line number
	     // but sometimes it does not because of optimization
	     result->uptr = filename;
             result->aname = NULL;

  81         audit_getname(result);

To prevent false failures, skip the affected tests
if no suitable line numbers can be detected.

Signed-off-by: Jakub Brnak <jbrnak@redhat.com>
---
v3:
- ensure POSIX compliance

v2: 
https://lore.kernel.org/linux-perf-users/Z9tKat6vvC1XUj0U@google.com/
- check if return from add_vfs_getname equals to 1
sice it is only option in case of fail 

v1:
 https://lore.kernel.org/linux-perf-users/Z8pAep0GJsMFTyEi@google.com/T/#t
---
 tools/perf/tests/shell/lib/probe_vfs_getname.sh          | 8 +++++++-
 tools/perf/tests/shell/probe_vfs_getname.sh              | 8 +++++++-
 .../perf/tests/shell/record+script_probe_vfs_getname.sh  | 8 +++++++-
 tools/perf/tests/shell/trace+probe_vfs_getname.sh        | 9 +++++++--
 4 files changed, 28 insertions(+), 5 deletions(-)

diff --git a/tools/perf/tests/shell/lib/probe_vfs_getname.sh b/tools/perf/tests/shell/lib/probe_vfs_getname.sh
index 5c33ec7a5a63..89f72a4c818c 100644
--- a/tools/perf/tests/shell/lib/probe_vfs_getname.sh
+++ b/tools/perf/tests/shell/lib/probe_vfs_getname.sh
@@ -19,8 +19,14 @@ add_probe_vfs_getname() {
 			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/$result_aname_re/\1/")
 		fi
+
+		if [ -z "$line" ] ; then
+			echo "Could not find probeable line"
+			return 2
+		fi
+
 		perf probe -q       "vfs_getname=getname_flags:${line} pathname=result->name:string" || \
-		perf probe $add_probe_verbose "vfs_getname=getname_flags:${line} pathname=filename:ustring"
+		perf probe $add_probe_verbose "vfs_getname=getname_flags:${line} pathname=filename:ustring" || return 1
 	fi
 }
 
diff --git a/tools/perf/tests/shell/probe_vfs_getname.sh b/tools/perf/tests/shell/probe_vfs_getname.sh
index c51a32931af6..0f52654c914a 100755
--- a/tools/perf/tests/shell/probe_vfs_getname.sh
+++ b/tools/perf/tests/shell/probe_vfs_getname.sh
@@ -13,7 +13,13 @@ skip_if_no_perf_probe || exit 2
 # shellcheck source=lib/probe_vfs_getname.sh
 . "$(dirname $0)"/lib/probe_vfs_getname.sh
 
-add_probe_vfs_getname || skip_if_no_debuginfo
+add_probe_vfs_getname
 err=$?
+
+if [ $err -eq 1 ] ; then
+	skip_if_no_debuginfo
+	err=$?
+fi
+
 cleanup_probe_vfs_getname
 exit $err
diff --git a/tools/perf/tests/shell/record+script_probe_vfs_getname.sh b/tools/perf/tests/shell/record+script_probe_vfs_getname.sh
index fd5b10d46915..1ad252f0d36e 100755
--- a/tools/perf/tests/shell/record+script_probe_vfs_getname.sh
+++ b/tools/perf/tests/shell/record+script_probe_vfs_getname.sh
@@ -35,8 +35,14 @@ perf_script_filenames() {
 	grep -E " +touch +[0-9]+ +\[[0-9]+\] +[0-9]+\.[0-9]+: +probe:vfs_getname[_0-9]*: +\([[:xdigit:]]+\) +pathname=\"${file}\""
 }
 
-add_probe_vfs_getname || skip_if_no_debuginfo
+add_probe_vfs_getname
 err=$?
+
+if [ $err -eq 1 ] ; then
+        skip_if_no_debuginfo
+        err=$?
+fi
+
 if [ $err -ne 0 ] ; then
 	exit $err
 fi
diff --git a/tools/perf/tests/shell/trace+probe_vfs_getname.sh b/tools/perf/tests/shell/trace+probe_vfs_getname.sh
index 60fccb62c540..5d5019988d61 100755
--- a/tools/perf/tests/shell/trace+probe_vfs_getname.sh
+++ b/tools/perf/tests/shell/trace+probe_vfs_getname.sh
@@ -25,9 +25,14 @@ trace_open_vfs_getname() {
 	grep -E " +[0-9]+\.[0-9]+ +\( +[0-9]+\.[0-9]+ ms\): +touch/[0-9]+ open(at)?\((dfd: +CWD, +)?filename: +\"?${file}\"?, +flags: CREAT\|NOCTTY\|NONBLOCK\|WRONLY, +mode: +IRUGO\|IWUGO\) += +[0-9]+$"
 }
 
-
-add_probe_vfs_getname || skip_if_no_debuginfo
+add_probe_vfs_getname
 err=$?
+
+if [ $err -eq 1 ] ; then
+        skip_if_no_debuginfo
+        err=$?
+fi
+
 if [ $err -ne 0 ] ; then
 	exit $err
 fi
-- 
2.48.1