Add dummy syscall sched_getaffinity

regression/apps/Makefile

@@ -12,6 +12,7 @@ REGRESSION_BUILD_DIR ?= $(INITRAMFS)/regression
 TEST_APPS := \
 	alarm \
 	clone3 \
+	cpu_affinity \
 	eventfd2 \
 	execve \
 	file_io \

regression/apps/cpu_affinity/Makefile

@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: MPL-2.0
+
+include ../test_common.mk
+
+EXTRA_C_FLAGS :=

regression/apps/cpu_affinity/sched_getaffinity.c

@@ -0,0 +1,35 @@
+// SPDX-License-Identifier: MPL-2.0
+
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <unistd.h>
+#include <syscall.h>
+#include <errno.h>
+#include <sched.h> // Include sched.h for CPU_SETSIZE
+
+int main()
+{
+	// Create a mask for CPU_SETSIZE number of CPUs
+	unsigned long mask[CPU_SETSIZE / sizeof(unsigned long)];
+	int mask_size = sizeof(mask);
+
+	// Call the raw syscall to retrieve the CPU affinity mask of the current process
+	long res = syscall(__NR_sched_getaffinity, 0, mask_size, &mask);
+
+	if (res < 0) {
+		perror("Error calling sched_getaffinity");
+		return errno;
+	}
+
+	// Print the CPUs that are part of the current process's affinity mask
+	printf("Process can run on: ");
+	for (int i = 0; i < CPU_SETSIZE; ++i) {
+		if (mask[i / (8 * sizeof(long))] &
+		    (1UL << (i % (8 * sizeof(long))))) {
+			printf("%d ", i);
+		}
+	}
+	printf("\n");
+
+	return 0;
+}