selftest/futex: Make the error check more precise for futex_numa_mpol

JIRA: https://issues.redhat.com/browse/RHEL-101190

commit c1c8634
Author: André Almeida <andrealmeid@igalia.com>
Date:   Mon, 15 Sep 2025 23:26:28 +0200

    selftest/futex: Make the error check more precise for futex_numa_mpol

    Instead of just checking if the syscall failed as expected, check as
    well if the returned error code matches the expected error code.

    [ bigeasy: reword the commmit message ]

    Signed-off-by: André Almeida <andrealmeid@igalia.com>
    Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
    Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
    Reviewed-by: Waiman Long <longman@redhat.com>

Signed-off-by: Waiman Long <longman@redhat.com>

Author: Waiman-Long

tools/testing/selftests/futex/functional/futex_numa_mpol.c

@@ -77,7 +77,7 @@ static void join_max_threads(void)
 	}
 }
 
-static void __test_futex(void *futex_ptr, int must_fail, unsigned int futex_flags)
+static void __test_futex(void *futex_ptr, int err_value, unsigned int futex_flags)
 {
 	int to_wake, ret, i, need_exit = 0;
 
@@ -88,11 +88,17 @@ static void __test_futex(void *futex_ptr, int must_fail, unsigned int futex_flag
 
 	do {
 		ret = futex2_wake(futex_ptr, to_wake, futex_flags);
-		if (must_fail) {
-			if (ret < 0)
-				break;
-			ksft_exit_fail_msg("futex2_wake(%d, 0x%x) should fail, but didn't\n",
-					   to_wake, futex_flags);
+
+		if (err_value) {
+			if (ret >= 0)
+				ksft_exit_fail_msg("futex2_wake(%d, 0x%x) should fail, but didn't\n",
+						   to_wake, futex_flags);
+
+			if (errno != err_value)
+				ksft_exit_fail_msg("futex2_wake(%d, 0x%x) expected error was %d, but returned %d (%s)\n",
+						   to_wake, futex_flags, err_value, errno, strerror(errno));
+
+			break;
 		}
 		if (ret < 0) {
 			ksft_exit_fail_msg("Failed futex2_wake(%d, 0x%x): %m\n",
@@ -106,12 +112,12 @@ static void __test_futex(void *futex_ptr, int must_fail, unsigned int futex_flag
 	join_max_threads();
 
 	for (i = 0; i < MAX_THREADS; i++) {
-		if (must_fail && thread_args[i].result != -1) {
+		if (err_value && thread_args[i].result != -1) {
 			ksft_print_msg("Thread %d should fail but succeeded (%d)\n",
 				       i, thread_args[i].result);
 			need_exit = 1;
 		}
-		if (!must_fail && thread_args[i].result != 0) {
+		if (!err_value && thread_args[i].result != 0) {
 			ksft_print_msg("Thread %d failed (%d)\n", i, thread_args[i].result);
 			need_exit = 1;
 		}
@@ -120,14 +126,14 @@ static void __test_futex(void *futex_ptr, int must_fail, unsigned int futex_flag
 		ksft_exit_fail_msg("Aborting due to earlier errors.\n");
 }
 
-static void test_futex(void *futex_ptr, int must_fail)
+static void test_futex(void *futex_ptr, int err_value)
 {
-	__test_futex(futex_ptr, must_fail, FUTEX2_SIZE_U32 | FUTEX_PRIVATE_FLAG | FUTEX2_NUMA);
+	__test_futex(futex_ptr, err_value, FUTEX2_SIZE_U32 | FUTEX_PRIVATE_FLAG | FUTEX2_NUMA);
 }
 
-static void test_futex_mpol(void *futex_ptr, int must_fail)
+static void test_futex_mpol(void *futex_ptr, int err_value)
 {
-	__test_futex(futex_ptr, must_fail, FUTEX2_SIZE_U32 | FUTEX_PRIVATE_FLAG | FUTEX2_NUMA | FUTEX2_MPOL);
+	__test_futex(futex_ptr, err_value, FUTEX2_SIZE_U32 | FUTEX_PRIVATE_FLAG | FUTEX2_NUMA | FUTEX2_MPOL);
 }
 
 static void usage(char *prog)
@@ -184,16 +190,16 @@ int main(int argc, char *argv[])
 
 	/* FUTEX2_NUMA futex must be 8-byte aligned */
 	ksft_print_msg("Mis-aligned futex\n");
-	test_futex(futex_ptr + mem_size - 4, 1);
+	test_futex(futex_ptr + mem_size - 4, EINVAL);
 
 	futex_numa->numa = FUTEX_NO_NODE;
 	mprotect(futex_ptr, mem_size, PROT_READ);
 	ksft_print_msg("Memory, RO\n");
-	test_futex(futex_ptr, 1);
+	test_futex(futex_ptr, EFAULT);
 
 	mprotect(futex_ptr, mem_size, PROT_NONE);
 	ksft_print_msg("Memory, no access\n");
-	test_futex(futex_ptr, 1);
+	test_futex(futex_ptr, EFAULT);
 
 	mprotect(futex_ptr, mem_size, PROT_READ | PROT_WRITE);
 	ksft_print_msg("Memory back to RW\n");