[LTP] [PATCH v2] vma05: Fix false positives from stripped system libraries

[Ben Copeland]

The vma05 test was producing false positive failures by flagging any
"??" symbols in gdb backtraces as vDSO kernel bugs, including those
from normal stripped system libraries.

This caused widespread false failures in production environments where
system libraries like libc.so.6 are typically stripped of debug symbols.

The fix filters out "??" symbols that originate from system libraries
(paths containing "/lib/" or "/usr/lib/") while still detecting genuine
unresolved symbols in application code that could indicate real vDSO bugs.

Signed-off-by: Ben Copeland <ben.copeland@linaro.org>
Reviewed-by: Petr Vorel <pvorel@suse.cz>
---
 testcases/kernel/mem/vma/vma05.sh | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/testcases/kernel/mem/vma/vma05.sh b/testcases/kernel/mem/vma/vma05.sh
index c560eecbc..1546342a8 100755
--- a/testcases/kernel/mem/vma/vma05.sh
+++ b/testcases/kernel/mem/vma/vma05.sh
@@ -64,8 +64,10 @@ tst_test()
 	TRACE=$(gdb -silent -ex="thread apply all backtrace" -ex="quit"\
 		vma05_vdso ./core* 2> /dev/null)
 
-	if echo "$TRACE" | grep -qF "??"; then
-		tst_res TFAIL "[vdso] bug not patched"
+	# Only check for ?? symbols in application code, not system libraries
+	APP_UNKNOWN=$(echo "$TRACE" | grep -F "??" | grep -v -e "from /lib/" -e "from /usr/lib/")
+	if [ -n "$APP_UNKNOWN" ]; then
+		tst_res TFAIL "[vdso] bug not patched - unknown symbols in application code"
 	else
 		tst_res TPASS "[vdso] backtrace complete"
 	fi
-- 
2.50.1