[PATCH v3 RESEND 2/2] selftests/mm: Only prepare ptrace_scope when memfd_secret is selected

[PATCH v3 RESEND 2/2] selftests/mm: Only prepare ptrace_scope when memfd_secret is selected

[Tianyi Chen]

From: Tianyi Chen <hi@tychen.cc>
Date: Tue, 08 Sep 2026 11:21:50 +0800

The memfd_secret setup clears ptrace_scope whenever its test binary is
executable, even when a different category was selected. run_test() filters
the test invocation, but it does not protect the preceding setup.

Check the category selection before entering the memfd_secret block so
running unrelated categories does not change ptrace_scope. Keep the
existing executable check and the behavior when memfd_secret is selected.

Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Assisted-by: LLM
Signed-off-by: Tianyi Chen <hi@tychen.cc>
---
 tools/testing/selftests/mm/run_vmtests.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/mm/run_vmtests.sh
b/tools/testing/selftests/mm/run_vmtests.sh
index 9e62ab4c6775..9bbef9410ccc 100755
--- a/tools/testing/selftests/mm/run_vmtests.sh
+++ b/tools/testing/selftests/mm/run_vmtests.sh
@@ -370,7 +370,7 @@ CATEGORY="process_madv" run_test ./process_madv

 CATEGORY="vma_merge" run_test ./merge

-if [ -x ./memfd_secret ]
+if test_selected "memfd_secret" && [ -x ./memfd_secret ]
 then
 if [ -f /proc/sys/kernel/yama/ptrace_scope ]; then
 	(echo 0 > /proc/sys/kernel/yama/ptrace_scope 2>&1) | tap_prefix

[PATCH v3 RESEND 0/2] selftests/mm: Validate selections and scope memfd_secret setup

[Tianyi Chen]

run_vmtests.sh can reach test setup after invalid options or category
selections. Its memfd_secret preparation can also change ptrace_scope
when that category was not selected.

Patch 1 rejects invalid selections before setup. Patch 2 gates
memfd_secret preparation on category selection and executable presence.

The patches and commit messages are unchanged from v3. This resend uses
git send-email through Gmail's SMTP server to send the patches inline.
Before resending, I sent them to my SpaceMail mailbox and verified the
received contents and whitespace. Both patches passed git apply --check
and git am, and the resulting trees matched the original commits.

David, this is my first time setting up Gmail SMTP for patch submission.
I'm very sorry for the formatting problems I caused and for taking up
so much of your time. Thank you for your patience.

Changes in v3:
- Initialize VM_SELFTEST_ITEMS to "default" before getopts, as David
  suggested. Only -t changes the selection.
- Use Assisted-by: LLM in both patches.
- Carry David's Acked-by on patch 2, unchanged from v2.

Tianyi Chen (2):
  selftests/mm: Reject invalid test selections before running tests
  selftests/mm: Only prepare ptrace_scope when memfd_secret is selected

 tools/testing/selftests/mm/run_vmtests.sh | 28 +++++++++++++++++++----
 1 file changed, 23 insertions(+), 5 deletions(-)

-- 
2.55.0

[PATCH v3 RESEND 1/2] selftests/mm: Reject invalid test selections before running tests

[Tianyi Chen]

From: Tianyi Chen <hi@tychen.cc>

getopts reports unknown options and missing arguments, but run_vmtests.sh
ignores its error result and continues with test setup. An empty -t
argument also falls back to the default selection, while unknown category
names can silently select no tests and still reach setup code.

Exit on getopts errors and validate category names against the existing
list in usage() before any test setup. Reject empty and whitespace-only
selections, and normalize category separators so validation and execution
agree. Initialize the default selection before parsing options so only -t
changes the selection.

Fixes: 85463321e726 ("selftests/vm: enable running select groups of tests")
Assisted-by: LLM
Signed-off-by: Tianyi Chen <hi@tychen.cc>
---
 tools/testing/selftests/mm/run_vmtests.sh | 26 +++++++++++++++++++----
 1 file changed, 22 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/mm/run_vmtests.sh b/tools/testing/selftests/mm/run_vmtests.sh
index d09f9f6a384e..9e62ab4c6775 100755
--- a/tools/testing/selftests/mm/run_vmtests.sh
+++ b/tools/testing/selftests/mm/run_vmtests.sh
@@ -96,26 +96,44 @@ separated by spaces:
 
 example: ./run_vmtests.sh -t "hmm mmap ksm"
 EOF
-	exit 0
 }
 
 RUN_ALL=false
 RUN_DESTRUCTIVE=false
 TAP_PREFIX="# "
 
+VM_SELFTEST_ITEMS="default"
+
 while getopts "aht:nd" OPT; do
 	case ${OPT} in
 		"a") RUN_ALL=true ;;
-		"h") usage ;;
+		"h") usage; exit 0 ;;
 		"t") VM_SELFTEST_ITEMS=${OPTARG} ;;
 		"n") TAP_PREFIX= ;;
 		"d") RUN_DESTRUCTIVE=true ;;
+		"?") exit 1 ;;
 	esac
 done
 shift $((OPTIND -1))
 
-# default behavior: run all tests
-VM_SELFTEST_ITEMS=${VM_SELFTEST_ITEMS:-default}
+# Normalize whitespace so validation and test_selected() use the same names.
+read -r -a selected_categories <<< "${VM_SELFTEST_ITEMS//$'\n'/ }"
+VM_SELFTEST_ITEMS="${selected_categories[*]}"
+if [ -z "$VM_SELFTEST_ITEMS" ]; then
+	echo "No test categories specified" >&2
+	exit 1
+fi
+
+if [ "$VM_SELFTEST_ITEMS" != "default" ]; then
+	# Keep the documented category list as the source of valid names.
+	valid_categories=$(usage | sed -n 's/^- //p')
+	for category in "${selected_categories[@]}"; do
+		if ! grep -Fxq -- "$category" <<< "$valid_categories"; then
+			echo "Unknown test category: $category" >&2
+			exit 1
+		fi
+	done
+fi
 
 test_selected() {
 	if [ "$VM_SELFTEST_ITEMS" == "default" ]; then
-- 
2.55.0

[PATCH v3 RESEND 2/2] selftests/mm: Only prepare ptrace_scope when memfd_secret is selected

[Tianyi Chen]

From: Tianyi Chen <hi@tychen.cc>

The memfd_secret setup clears ptrace_scope whenever its test binary is
executable, even when a different category was selected. run_test() filters
the test invocation, but it does not protect the preceding setup.

Check the category selection before entering the memfd_secret block so
running unrelated categories does not change ptrace_scope. Keep the
existing executable check and the behavior when memfd_secret is selected.

Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Assisted-by: LLM
Signed-off-by: Tianyi Chen <hi@tychen.cc>
---
 tools/testing/selftests/mm/run_vmtests.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/mm/run_vmtests.sh b/tools/testing/selftests/mm/run_vmtests.sh
index 9e62ab4c6775..9bbef9410ccc 100755
--- a/tools/testing/selftests/mm/run_vmtests.sh
+++ b/tools/testing/selftests/mm/run_vmtests.sh
@@ -370,7 +370,7 @@ CATEGORY="process_madv" run_test ./process_madv
 
 CATEGORY="vma_merge" run_test ./merge
 
-if [ -x ./memfd_secret ]
+if test_selected "memfd_secret" && [ -x ./memfd_secret ]
 then
 if [ -f /proc/sys/kernel/yama/ptrace_scope ]; then
 	(echo 0 > /proc/sys/kernel/yama/ptrace_scope 2>&1) | tap_prefix
-- 
2.55.0