[PATCH v7 12/13] selftests/mm: move hwpoison setup into run_test() and silence modprobe output for memory-failure category

[Sayali Patil]

run_vmtests.sh contains special handling to ensure the hwpoison_inject
module is available for the memory-failure tests. This logic was
implemented outside of run_test(), making the setup category-specific
but managed globally.

Move the hwpoison_inject handling into run_test() and restrict it
to the memory-failure category so that:
1. the module is checked and loaded only when memory-failure tests run,
2. the test is skipped if the module or the debugfs interface
(/sys/kernel/debug/hwpoison/) is not available.
3. the module is unloaded after the test if it was loaded by the script.

This localizes category-specific setup and makes the test flow
consistent with other per-category preparations.

While updating this logic, fix the module availability check.
The script previously used:

        modprobe -R hwpoison_inject

The -R option prints the resolved module name to stdout, causing every
run to print:

        hwpoison_inject

in the test output, even when no action is required, introducing
unnecessary noise.

Replace this with:

        modprobe -n hwpoison_inject

which verifies that the module is loadable without producing output,
keeping the selftest logs clean and consistent.

Also, ensure that skipped tests do not override a previously recorded
failure. A skipped test currently sets exitcode to ksft_skip even if a
prior test has failed, which can mask failures in the final exit status.
Update the logic to only set exitcode to ksft_skip when no failure has
been recorded.

Fixes: ff4ef2fbd101 ("selftests/mm: add memory failure anonymous page test")
Reviewed-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Tested-by: Venkat Rao Bagalkote <venkat88@xxxxxxxxxxxxx>
Signed-off-by: Sayali Patil <sayalip@xxxxxxxxxxxxx>
---
 tools/testing/selftests/mm/run_vmtests.sh | 62 +++++++++++++++--------
 1 file changed, 41 insertions(+), 21 deletions(-)

diff --git a/tools/testing/selftests/mm/run_vmtests.sh b/tools/testing/selftests/mm/run_vmtests.sh
index 043aa3ed2596..8c296dedf047 100755
--- a/tools/testing/selftests/mm/run_vmtests.sh
+++ b/tools/testing/selftests/mm/run_vmtests.sh
@@ -180,6 +180,9 @@ pretty_name() {
 # Usage: run_test [test binary] [arbitrary test arguments...]
 run_test() {
 	if test_selected ${CATEGORY}; then
+		local skip=0
+		local LOADED_HWPOISON_INJECT_MOD=0
+
 		# On memory constrainted systems some tests can fail to allocate hugepages.
 		# perform some cleanup before the test for a higher success rate.
 		if [ ${CATEGORY} == "thp" -o ${CATEGORY} == "hugetlb" ]; then
@@ -194,13 +197,45 @@ run_test() {
 			fi
 		fi
 
+		# Ensure hwpoison_inject is available for memory-failure tests
+		if [ "${CATEGORY}" = "memory-failure" ]; then
+			# Try to load hwpoison_inject if not present.
+			HWPOISON_DIR=/sys/kernel/debug/hwpoison/
+			if [ ! -d "$HWPOISON_DIR" ]; then
+				if ! modprobe -n hwpoison_inject > /dev/null 2>&1; then
+					echo "Module hwpoison_inject not found, skipping..." \
+						| tap_prefix
+					skip=1
+				else
+					modprobe hwpoison_inject > /dev/null 2>&1
+					LOADED_HWPOISON_INJECT_MOD=1
+					if [ ! -d "$HWPOISON_DIR" ]; then
+						echo "hwpoison debugfs interface not present" \
+							| tap_prefix
+						skip=1
+					fi
+				fi
+			fi
+
+		fi
+
 		local test=$(pretty_name "$*")
 		local title="running $*"
 		local sep=$(echo -n "$title" | tr "[:graph:][:space:]" -)
 		printf "%s\n%s\n%s\n" "$sep" "$title" "$sep" | tap_prefix
 
-                ("$@" 2>&1) | tap_prefix
-                local ret=${PIPESTATUS[0]}
+		if [ $skip -eq 1 ]; then
+			local ret=$ksft_skip
+		else
+			("$@" 2>&1) | tap_prefix
+			local ret=${PIPESTATUS[0]}
+		fi
+
+		# Unload hwpoison_inject if we loaded it
+		if [ "${LOADED_HWPOISON_INJECT_MOD}" = "1" ]; then
+			modprobe -r hwpoison_inject > /dev/null 2>&1
+		fi
+
 		count_total=$(( count_total + 1 ))
 		if [ $ret -eq 0 ]; then
 			count_pass=$(( count_pass + 1 ))
@@ -210,7 +245,9 @@ run_test() {
 			count_skip=$(( count_skip + 1 ))
 			echo "[SKIP]" | tap_prefix
 			echo "ok ${count_total} ${test} # SKIP" | tap_output
-			exitcode=$ksft_skip
+			if [ $exitcode -eq 0 ]; then
+				exitcode=$ksft_skip
+			fi
 		else
 			count_fail=$(( count_fail + 1 ))
 			echo "[FAIL]" | tap_prefix
@@ -422,24 +459,7 @@ CATEGORY="page_frag" run_test ./test_page_frag.sh nonaligned
 
 CATEGORY="rmap" run_test ./rmap
 
-# Try to load hwpoison_inject if not present.
-HWPOISON_DIR=/sys/kernel/debug/hwpoison/
-if [ ! -d "$HWPOISON_DIR" ]; then
-	if ! modprobe -q -R hwpoison_inject; then
-		echo "Module hwpoison_inject not found, skipping..."
-	else
-		modprobe hwpoison_inject > /dev/null 2>&1
-		LOADED_MOD=1
-	fi
-fi
-
-if [ -d "$HWPOISON_DIR" ]; then
-	CATEGORY="memory-failure" run_test ./memory-failure
-fi
-
-if [ -n "${LOADED_MOD}" ]; then
-	modprobe -r hwpoison_inject > /dev/null 2>&1
-fi
+CATEGORY="memory-failure" run_test ./memory-failure
 
 echo "SUMMARY: PASS=${count_pass} SKIP=${count_skip} FAIL=${count_fail}" | tap_prefix
 echo "1..${count_total}" | tap_output
-- 
2.52.0