From d6ea9f404b905ba7351d6b0e9ed611d9d0bf20f7 Mon Sep 17 00:00:00 2001
From: =?utf8?q?Ricardo=20B=2E=20Marli=C3=A8re?= <rbm@suse.com>
Date: Fri, 20 Mar 2026 15:29:19 -0300
Subject: [PATCH] selftests/run_kselftest.sh: Allow choosing per-test log
 directory
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The --per-test-log option currently hard-codes /tmp. However, the system
under test will most likely have tmpfs mounted there. Since it's not clear
which filenames the log files will have, the user should be able to specify
a persistent directory to store the logs. Keeping those logs are important
because the run_kselftest.sh runner will only yield KTAP output, trimming
information that is otherwise available through running individual tests
directly.

Allow --per-test-log to take an optional directory argument. Keep the
existing behaviour when the option is passed without an argument, but if
a directory is provided, create it if needed, reject non-directory paths
and non-writable directories, canonicalize it, and have runner.sh write
per-test logs there instead of /tmp.

This also makes relative paths safe by resolving them before the runner
changes into a collection directory.

Signed-off-by: Ricardo B. Marlière <rbm@suse.com>
Link: https://lore.kernel.org/r/20260320-selftests-fixes-v1-4-79144f76be01@suse.com
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
---
 tools/testing/selftests/kselftest/runner.sh |  3 ++-
 tools/testing/selftests/run_kselftest.sh    | 30 +++++++++++++++++++--
 2 files changed, 30 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/kselftest/runner.sh b/tools/testing/selftests/kselftest/runner.sh
index 3eeec93c9da42..6da3390825fe6 100644
--- a/tools/testing/selftests/kselftest/runner.sh
+++ b/tools/testing/selftests/kselftest/runner.sh
@@ -6,6 +6,7 @@
 export timeout_rc=124
 export logfile=/dev/stdout
 export per_test_logging=
+export per_test_log_dir=/tmp
 export RUN_IN_NETNS=
 
 # Defaults for "settings" file fields:
@@ -196,7 +197,7 @@ run_many()
 		BASENAME_TEST=$(basename $TEST)
 		test_num=$(( test_num + 1 ))
 		if [ -n "$per_test_logging" ]; then
-			logfile="/tmp/$BASENAME_TEST"
+			logfile="$per_test_log_dir/$BASENAME_TEST"
 			cat /dev/null > "$logfile"
 		fi
 		if [ -n "$RUN_IN_NETNS" ]; then
diff --git a/tools/testing/selftests/run_kselftest.sh b/tools/testing/selftests/run_kselftest.sh
index 8fa808e10455e..e11b0e93ba41f 100755
--- a/tools/testing/selftests/run_kselftest.sh
+++ b/tools/testing/selftests/run_kselftest.sh
@@ -22,7 +22,7 @@ usage()
 	cat <<EOF
 Usage: $0 [OPTIONS]
   -s | --summary		Print summary with detailed log in output.log (conflict with -p)
-  -p | --per-test-log		Print test log in /tmp with each test name (conflict with -s)
+  -p | --per-test-log [DIR]	Print test log in /tmp or DIR with each test name (conflict with -s)
   -t | --test COLLECTION:TEST	Run TEST from COLLECTION
   -S | --skip COLLECTION:TEST	Skip TEST from COLLECTION
   -c | --collection COLLECTION	Run all tests from COLLECTION
@@ -50,7 +50,33 @@ while true; do
 			shift ;;
 		-p | --per-test-log)
 			per_test_logging=1
-			shift ;;
+			if [ -n "$2" ] && [ "${2#-}" = "$2" ]; then
+				per_test_log_dir="$2"
+				if [ -e "$per_test_log_dir" ] && [ ! -d "$per_test_log_dir" ]; then
+					echo "Per-test log path is not a dir:" \
+					     "$per_test_log_dir" >&2
+					exit 1
+				fi
+				if [ ! -d "$per_test_log_dir" ] && \
+				   ! mkdir -p "$per_test_log_dir"; then
+					echo "Could not create log dir:" \
+					     "$per_test_log_dir" >&2
+					exit 1
+				fi
+				per_test_log_dir=$(cd "$per_test_log_dir" && pwd -P)
+				if [ -z "$per_test_log_dir" ]; then
+					echo "Could not resolve per-test log directory" >&2
+					exit 1
+				fi
+				if [ ! -w "$per_test_log_dir" ]; then
+					echo "Per-test log dir is not writable:" \
+					     "$per_test_log_dir" >&2
+					exit 1
+				fi
+				shift 2
+			else
+				shift
+			fi ;;
 		-t | --test)
 			TESTS="$TESTS $2"
 			shift 2 ;;
-- 
2.47.3