diff --git a/arch/arm64/kernel/include/syscall_list.h b/arch/arm64/kernel/include/syscall_list.h
index 4747f3a4..b3c56b85 100644
--- a/arch/arm64/kernel/include/syscall_list.h
+++ b/arch/arm64/kernel/include/syscall_list.h
@@ -7,11 +7,7 @@ SYSCALL_DELEGATED(25, fcntl)
 SYSCALL_HANDLED(29, ioctl)
 SYSCALL_DELEGATED(43, statfs)
 SYSCALL_DELEGATED(44, fstatfs)
-#ifdef POSTK_DEBUG_ARCH_DEP_62 /* Absorb the difference between open and openat args. */
 SYSCALL_HANDLED(56, openat)
-#else /* POSTK_DEBUG_ARCH_DEP_62 */
-SYSCALL_DELEGATED(56, openat)
-#endif /* POSTK_DEBUG_ARCH_DEP_62 */
 SYSCALL_HANDLED(57, close)
 SYSCALL_DELEGATED(61, getdents64)
 SYSCALL_DELEGATED(62, lseek)
diff --git a/arch/x86_64/kernel/include/syscall_list.h b/arch/x86_64/kernel/include/syscall_list.h
index 6de0cccc..ce28d52e 100644
--- a/arch/x86_64/kernel/include/syscall_list.h
+++ b/arch/x86_64/kernel/include/syscall_list.h
@@ -133,9 +133,7 @@ SYSCALL_HANDLED(238, set_mempolicy)
 SYSCALL_HANDLED(239, get_mempolicy)
 SYSCALL_HANDLED(247, waitid)
 SYSCALL_HANDLED(256, migrate_pages)
-#ifdef POSTK_DEBUG_ARCH_DEP_62 /* Absorb the difference between open and openat args. */
 SYSCALL_HANDLED(257, openat)
-#endif  /* POSTK_DEBUG_ARCH_DEP_62 */
 SYSCALL_DELEGATED(270, pselect6)
 SYSCALL_DELEGATED(271, ppoll)
 SYSCALL_HANDLED(273, set_robust_list)
diff --git a/kernel/include/xpmem.h b/kernel/include/xpmem.h
index bb4a7772..5c3fb330 100644
--- a/kernel/include/xpmem.h
+++ b/kernel/include/xpmem.h
@@ -19,14 +19,13 @@
 
 #define XPMEM_DEV_PATH  "/dev/xpmem"
 
-#if defined(POSTK_DEBUG_ARCH_DEP_46) || defined(POSTK_DEBUG_ARCH_DEP_62)
-extern int xpmem_open(int, const char*, int, ihk_mc_user_context_t *ctx);
-#else /* POSTK_DEBUG_ARCH_DEP_46 || POSTK_DEBUG_ARCH_DEP_62 */
-extern int xpmem_open(ihk_mc_user_context_t *ctx);
-#endif /* POSTK_DEBUG_ARCH_DEP_46 || POSTK_DEBUG_ARCH_DEP_62 */
-extern int xpmem_remove_process_memory_range(struct process_vm *vm, 
+int xpmem_open(const char *pathname,
+	       int flags, ihk_mc_user_context_t *ctx);
+int xpmem_openat(const char *pathname,
+		 int flags, ihk_mc_user_context_t *ctx);
+int xpmem_remove_process_memory_range(struct process_vm *vm,
 	struct vm_range *vmr);
-extern int xpmem_fault_process_memory_range(struct process_vm *vm, 
+int xpmem_fault_process_memory_range(struct process_vm *vm,
 	struct vm_range *vmr, unsigned long vaddr, uint64_t reason);
 
 #endif /* _XPMEM_H */
diff --git a/kernel/include/xpmem_private.h b/kernel/include/xpmem_private.h
index a12c406a..48d2b6e3 100644
--- a/kernel/include/xpmem_private.h
+++ b/kernel/include/xpmem_private.h
@@ -305,8 +305,8 @@ static int xpmem_pin_page(struct xpmem_thread_group *, struct thread *,
 static void xpmem_unpin_pages(struct xpmem_segment *, struct process_vm *, 
 	unsigned long, size_t);
 
-static struct xpmem_thread_group * __xpmem_tg_ref_by_tgid_nolock_internal(
-	pid_t, int, int);
+static struct xpmem_thread_group *__xpmem_tg_ref_by_tgid_nolock_internal(
+	pid_t tgid, int index, int return_destroying);
 
 static inline struct xpmem_thread_group *__xpmem_tg_ref_by_tgid(
 	pid_t tgid,
@@ -355,16 +355,16 @@ static inline struct xpmem_thread_group *__xpmem_tg_ref_by_tgid_nolock(
 #define xpmem_tg_ref_by_tgid_nolock(t)      __xpmem_tg_ref_by_tgid_nolock(t, 0)
 #define xpmem_tg_ref_by_tgid_all_nolock(t)  __xpmem_tg_ref_by_tgid_nolock(t, 1)
 
-static struct xpmem_thread_group * xpmem_tg_ref_by_segid(xpmem_segid_t);
-static struct xpmem_thread_group * xpmem_tg_ref_by_apid(xpmem_apid_t);
-static void xpmem_tg_deref(struct xpmem_thread_group *);
+static struct xpmem_thread_group *xpmem_tg_ref_by_segid(xpmem_segid_t);
+static struct xpmem_thread_group *xpmem_tg_ref_by_apid(xpmem_apid_t);
+static void xpmem_tg_deref(struct xpmem_thread_group *tg);
 static struct xpmem_segment *xpmem_seg_ref_by_segid(struct xpmem_thread_group *,
 	xpmem_segid_t);
-static void xpmem_seg_deref(struct xpmem_segment *);
+static void xpmem_seg_deref(struct xpmem_segment *seg);
 static struct xpmem_access_permit * xpmem_ap_ref_by_apid(
-	struct xpmem_thread_group *, xpmem_apid_t);
-static void xpmem_ap_deref(struct xpmem_access_permit *);
-static void xpmem_att_deref(struct xpmem_attachment *);
+	struct xpmem_thread_group *ap_tg, xpmem_apid_t apid);
+static void xpmem_ap_deref(struct xpmem_access_permit *ap);
+static void xpmem_att_deref(struct xpmem_attachment *att);
 static int xpmem_validate_access(struct xpmem_access_permit *, off_t, size_t,
 	int, unsigned long *);
 
diff --git a/kernel/syscall.c b/kernel/syscall.c
index 67dc258d..6f3e698f 100644
--- a/kernel/syscall.c
+++ b/kernel/syscall.c
@@ -3486,66 +3486,67 @@ SYSCALL_DECLARE(ioctl)
 
 SYSCALL_DECLARE(open)
 {
-	const char *pathname = (const char *)ihk_mc_syscall_arg0(ctx);
+	const char *_pathname = (const char *)ihk_mc_syscall_arg0(ctx);
+	int flags = (int)ihk_mc_syscall_arg1(ctx);
 	int len;
-	char *xpmem_wk;
+	char *pathname;
 	long rc;
 
-	len = strlen_user(pathname);
+	len = strlen_user(_pathname);
 	if (len < 0)
 		return len;
-	if (!(xpmem_wk = kmalloc(len + 1, IHK_MC_AP_NOWAIT)))
-		return -ENOMEM;
-	if (copy_from_user(xpmem_wk, pathname, len + 1)) {
-		kfree(xpmem_wk);
-		return -EFAULT;
-	}
-	dkprintf("open(): pathname=%s\n", xpmem_wk);
-	rc = strcmp(xpmem_wk, XPMEM_DEV_PATH);
-#ifdef POSTK_DEBUG_ARCH_DEP_62 /* Absorb the difference between open and openat args. */
-	if (!rc) {
-		rc = xpmem_open(__NR_open, xpmem_wk, (int)ihk_mc_syscall_arg1(ctx), ctx);
-	}
-	else {
-		rc = syscall_generic_forwarding(__NR_open, ctx);
-	}
-	kfree(xpmem_wk);
-#else /* POSTK_DEBUG_ARCH_DEP_62 */
-	kfree(xpmem_wk);
-	if (!rc) {
-		rc = xpmem_open(ctx);
-	}
-	else {
-		rc = syscall_generic_forwarding(__NR_open, ctx);
-	}
-#endif /* POSTK_DEBUG_ARCH_DEP_62 */
-
-	return rc;
-}
-
-#ifdef POSTK_DEBUG_ARCH_DEP_62 /* Absorb the difference between open and openat args. */
-SYSCALL_DECLARE(openat)
-{
-	const char *pathname_user = (const char *)ihk_mc_syscall_arg1(ctx);
-	int flags = (int)ihk_mc_syscall_arg2(ctx);
-	char *pathname;
-	int len = strlen_user(pathname_user) + 1;
-	long rc;
+	len++;
 
 	pathname = kmalloc(len, IHK_MC_AP_NOWAIT);
 	if (!pathname) {
-		dkprintf("%s: error allocating pathname\n", __FUNCTION__);
+		dkprintf("%s: error allocating pathname\n", __func__);
 		return -ENOMEM;
 	}
-	if (copy_from_user(pathname, pathname_user, len)) {
-		dkprintf("%s: error: copy_from_user pathname\n", __FUNCTION__);
+	if (copy_from_user(pathname, _pathname, len)) {
+		dkprintf("%s: error: copy_from_user pathname\n", __func__);
+		rc = -EFAULT;
+		goto out;
+	}
+
+	dkprintf("open(): pathname=%s\n", pathname);
+	if (!strncmp(pathname, XPMEM_DEV_PATH, len)) {
+		rc = xpmem_open(pathname, flags, ctx);
+	} else {
+		rc = syscall_generic_forwarding(__NR_open, ctx);
+	}
+
+ out:
+	kfree(pathname);
+	return rc;
+}
+
+SYSCALL_DECLARE(openat)
+{
+	const char *_pathname = (const char *)ihk_mc_syscall_arg1(ctx);
+	int flags = (int)ihk_mc_syscall_arg2(ctx);
+	char *pathname;
+	int len;
+	long rc;
+
+	len = strlen_user(_pathname);
+	if (len < 0)
+		return len;
+	len++;
+
+	pathname = kmalloc(len, IHK_MC_AP_NOWAIT);
+	if (!pathname) {
+		dkprintf("%s: error allocating pathname\n", __func__);
+		return -ENOMEM;
+	}
+	if (copy_from_user(pathname, _pathname, len)) {
+		dkprintf("%s: error: copy_from_user pathname\n", __func__);
 		rc = -EFAULT;
 		goto out;
 	}
 
 	dkprintf("openat(): pathname=%s\n", pathname);
-	if (!strcmp(pathname, XPMEM_DEV_PATH)) {
-		rc = xpmem_open(__NR_openat, pathname, flags, ctx);
+	if (!strncmp(pathname, XPMEM_DEV_PATH, len)) {
+		rc = xpmem_openat(pathname, flags, ctx);
 	} else {
 		rc = syscall_generic_forwarding(__NR_openat, ctx);
 	}
@@ -3554,7 +3555,6 @@ out:
 	kfree(pathname);
 	return rc;
 }
-#endif /* POSTK_DEBUG_ARCH_DEP_62 */
 
 SYSCALL_DECLARE(close)
 {
diff --git a/kernel/xpmem.c b/kernel/xpmem.c
index 8419409d..4de99832 100644
--- a/kernel/xpmem.c
+++ b/kernel/xpmem.c
@@ -36,9 +36,7 @@
 
 struct xpmem_partition *xpmem_my_part = NULL;  /* pointer to this partition */
 
-
-#if defined(POSTK_DEBUG_ARCH_DEP_46) || defined(POSTK_DEBUG_ARCH_DEP_62)
-int xpmem_open(int num, const char *pathname,
+static int do_xpmem_open(int syscall_num, const char *pathname,
 		int flags, ihk_mc_user_context_t *ctx)
 {
 	int ret;
@@ -48,23 +46,8 @@ int xpmem_open(int num, const char *pathname,
 	struct mckfd *mckfd;
 	long irqstate;
 
-	XPMEM_DEBUG("call: syscall_num=%d, pathname=%s, flags=%d", num, pathname, flags);
-#else /* POSTK_DEBUG_ARCH_DEP_46 || POSTK_DEBUG_ARCH_DEP_62 */
-int xpmem_open(
-	ihk_mc_user_context_t *ctx)
-{
-	const char *pathname = (const char *)ihk_mc_syscall_arg0(ctx);
-	int flags = (int)ihk_mc_syscall_arg1(ctx);
-	int ret;
-	struct thread *thread = cpu_local_var(current);
-	struct process *proc = thread->proc;
-	struct syscall_request request IHK_DMA_ALIGN;
-	int fd;
-	struct mckfd *mckfd;
-	long irqstate;
-
-	XPMEM_DEBUG("call: pathname=%s, flags=%d", pathname, flags);
-#endif /* POSTK_DEBUG_ARCH_DEP_46 || POSTK_DEBUG_ARCH_DEP_62 */
+	XPMEM_DEBUG("call: syscall_num=%d, pathname=%s, flags=%d",
+		syscall_num, pathname, flags);
 
 	if (!xpmem_my_part) {
 		ret = xpmem_init();
@@ -73,22 +56,11 @@ int xpmem_open(
 		}
 	}
 
-#ifdef POSTK_DEBUG_ARCH_DEP_62 /* Absorb the difference between open and openat args. */
-	fd = syscall_generic_forwarding(num, ctx);
+	fd = syscall_generic_forwarding(syscall_num, ctx);
 	if(fd < 0){
-		XPMEM_DEBUG("syscall_num=%d error: fd=%d", num, fd);
+		XPMEM_DEBUG("syscall_num=%d error: fd=%d", syscall_num, fd);
 		return fd;
 	}
-#else /* POSTK_DEBUG_ARCH_DEP_62 */
-	request.number = __NR_open;
-	request.args[0] = (unsigned long)pathname;
-	request.args[1] = flags;
-	fd = do_syscall(&request, ihk_mc_get_processor_id());
-	if (fd < 0) {
-		XPMEM_DEBUG("__NR_open error: fd=%d", fd);
-		return fd;
-	}
-#endif /* POSTK_DEBUG_ARCH_DEP_62 */
 
 	ret = __xpmem_open();
 	if (ret) {
@@ -129,6 +101,17 @@ int xpmem_open(
 	return mckfd->fd;
 }
 
+int xpmem_open(const char *pathname,
+		int flags, ihk_mc_user_context_t *ctx)
+{
+	return do_xpmem_open(__NR_open, pathname, flags, ctx);
+}
+
+int xpmem_openat(const char *pathname,
+		int flags, ihk_mc_user_context_t *ctx)
+{
+	return do_xpmem_open(__NR_openat, pathname, flags, ctx);
+}
 
 static int xpmem_ioctl(
 	struct mckfd *mckfd,
@@ -2127,7 +2110,7 @@ static void xpmem_unpin_pages(
 }
 
 
-static struct xpmem_thread_group * __xpmem_tg_ref_by_tgid_nolock_internal(
+static struct xpmem_thread_group *__xpmem_tg_ref_by_tgid_nolock_internal(
 	pid_t tgid,
 	int index,
 	int return_destroying)
@@ -2152,7 +2135,7 @@ static struct xpmem_thread_group * __xpmem_tg_ref_by_tgid_nolock_internal(
 }
 
 
-static struct xpmem_thread_group * xpmem_tg_ref_by_segid(
+static struct xpmem_thread_group *xpmem_tg_ref_by_segid(
 	xpmem_segid_t segid)
 {
 	struct xpmem_thread_group *tg;
@@ -2163,7 +2146,7 @@ static struct xpmem_thread_group * xpmem_tg_ref_by_segid(
 }
 
 
-static struct xpmem_thread_group * xpmem_tg_ref_by_apid(
+static struct xpmem_thread_group *xpmem_tg_ref_by_apid(
 	xpmem_apid_t apid)
 {
 	struct xpmem_thread_group *tg;
@@ -2215,8 +2198,7 @@ static struct xpmem_segment * xpmem_seg_ref_by_segid(
 }
 
 
-static void xpmem_seg_deref(
-	struct xpmem_segment *seg)
+static void xpmem_seg_deref(struct xpmem_segment *seg)
 {
 	DBUG_ON(ihk_atomic_read(&seg->refcnt) <= 0);
 	if (ihk_atomic_dec_return(&seg->refcnt) != 0) {
@@ -2262,8 +2244,7 @@ static struct xpmem_access_permit * xpmem_ap_ref_by_apid(
 }
 
 
-static void xpmem_ap_deref(
-	struct xpmem_access_permit *ap)
+static void xpmem_ap_deref(struct xpmem_access_permit *ap)
 {
 	DBUG_ON(ihk_atomic_read(&ap->refcnt) <= 0);
 	if (ihk_atomic_dec_return(&ap->refcnt) != 0) {
@@ -2278,8 +2259,7 @@ static void xpmem_ap_deref(
 }
 
 
-static void xpmem_att_deref(
-	struct xpmem_attachment *att)
+static void xpmem_att_deref(struct xpmem_attachment *att)
 {
 	DBUG_ON(ihk_atomic_read(&att->refcnt) <= 0);
 	if (ihk_atomic_dec_return(&att->refcnt) != 0) {