[PATCH net v2] selftests/vsock: avoid false-positives when checking dmesg

[Bobby Eshleman <bobbyeshleman@gmail.com>]

From: Bobby Eshleman <bobbyeshleman@meta.com>

Sometimes VMs will have some intermittent dmesg warnings that are
unrelated to vsock. Change the dmesg parsing to filter on strings
containing 'vsock' to avoid false positive failures that are unrelated
to vsock. The downside is that it is possible for some vsock related
warnings to not contain the substring 'vsock', so those will be missed.

Fixes: a4a65c6fe08b ("selftests/vsock: add initial vmtest.sh for vsock")
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Bobby Eshleman <bobbyeshleman@meta.com>
---
Previously was part of the series:
https://lore.kernel.org/all/20251022-vsock-selftests-fixes-and-improvements-v1-0-edeb179d6463@meta.com/
---
Changes in v2:
- use consistent quoting for vsock string
- Link to v1: https://lore.kernel.org/r/20251104-vsock-vmtest-dmesg-fix-v1-1-80c8db3f5dfe@meta.com
---
 tools/testing/selftests/vsock/vmtest.sh | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/vsock/vmtest.sh b/tools/testing/selftests/vsock/vmtest.sh
index edacebfc1632..8ceeb8a7894f 100755
--- a/tools/testing/selftests/vsock/vmtest.sh
+++ b/tools/testing/selftests/vsock/vmtest.sh
@@ -389,9 +389,9 @@ run_test() {
 	local rc
 
 	host_oops_cnt_before=$(dmesg | grep -c -i 'Oops')
-	host_warn_cnt_before=$(dmesg --level=warn | wc -l)
+	host_warn_cnt_before=$(dmesg --level=warn | grep -c -i 'vsock')
 	vm_oops_cnt_before=$(vm_ssh -- dmesg | grep -c -i 'Oops')
-	vm_warn_cnt_before=$(vm_ssh -- dmesg --level=warn | wc -l)
+	vm_warn_cnt_before=$(vm_ssh -- dmesg --level=warn | grep -c -i 'vsock')
 
 	name=$(echo "${1}" | awk '{ print $1 }')
 	eval test_"${name}"
@@ -403,7 +403,7 @@ run_test() {
 		rc=$KSFT_FAIL
 	fi
 
-	host_warn_cnt_after=$(dmesg --level=warn | wc -l)
+	host_warn_cnt_after=$(dmesg --level=warn | grep -c -i 'vsock')
 	if [[ ${host_warn_cnt_after} -gt ${host_warn_cnt_before} ]]; then
 		echo "FAIL: kernel warning detected on host" | log_host "${name}"
 		rc=$KSFT_FAIL
@@ -415,7 +415,7 @@ run_test() {
 		rc=$KSFT_FAIL
 	fi
 
-	vm_warn_cnt_after=$(vm_ssh -- dmesg --level=warn | wc -l)
+	vm_warn_cnt_after=$(vm_ssh -- dmesg --level=warn | grep -c -i 'vsock')
 	if [[ ${vm_warn_cnt_after} -gt ${vm_warn_cnt_before} ]]; then
 		echo "FAIL: kernel warning detected on vm" | log_host "${name}"
 		rc=$KSFT_FAIL

---
base-commit: 89aec171d9d1ab168e43fcf9754b82e4c0aef9b9
change-id: 20251104-vsock-vmtest-dmesg-fix-b2c59e1d9c38

Best regards,
-- 
Bobby Eshleman <bobbyeshleman@meta.com>