[PATCH net-next 2/2] selftests/vsock: fix vsock_test path shadowing in nested VMs

[Bobby Eshleman <bobbyeshleman@gmail.com>]

From: Bobby Eshleman <bobbyeshleman@meta.com>

The /root mount introduced for nested VM support shadows any host paths
under /root. This breaks systems where the outer VM runs as root and the
vsock_test binary path is something like:

/root/linux/tools/testing/selftests/vsock/vsock_test

Fix this by copying vsock_test into the temporary home directory that
gets mounted as /root in the guest, and using a relative path to invoke
it.

Signed-off-by: Bobby Eshleman <bobbyeshleman@meta.com>
---
 tools/testing/selftests/vsock/vmtest.sh | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/vsock/vmtest.sh b/tools/testing/selftests/vsock/vmtest.sh
index c2cfcdf05d99..8182c748f214 100755
--- a/tools/testing/selftests/vsock/vmtest.sh
+++ b/tools/testing/selftests/vsock/vmtest.sh
@@ -393,6 +393,7 @@ handle_build() {
 setup_home() {
 	mkdir -p "$(dirname "${SSH_KEY_PATH}")"
 	ssh-keygen -t ed25519 -f "${SSH_KEY_PATH}" -N "" -q
+	cp "${VSOCK_TEST}" "${TEST_HOME}"/vsock_test
 }
 
 create_pidfile() {
@@ -601,7 +602,7 @@ vm_vsock_test() {
 	# log output and use pipefail to respect vsock_test errors
 	set -o pipefail
 	if [[ "${host}" != server ]]; then
-		vm_ssh "${ns}" -- "${VSOCK_TEST}" \
+		vm_ssh "${ns}" -- ./vsock_test \
 			--mode=client \
 			--control-host="${host}" \
 			--peer-cid="${cid}" \
@@ -609,7 +610,7 @@ vm_vsock_test() {
 			2>&1 | log_guest
 		rc=$?
 	else
-		vm_ssh "${ns}" -- "${VSOCK_TEST}" \
+		vm_ssh "${ns}" -- ./vsock_test \
 			--mode=server \
 			--peer-cid="${cid}" \
 			--control-port="${port}" \

-- 
2.52.0