diff --git a/executer/kernel/mcctrl/binfmt_mcexec.c b/executer/kernel/mcctrl/binfmt_mcexec.c
index 971944b2..0685e70b 100644
--- a/executer/kernel/mcctrl/binfmt_mcexec.c
+++ b/executer/kernel/mcctrl/binfmt_mcexec.c
@@ -75,7 +75,7 @@ static int load_elf(struct linux_binprm *bprm
 	char buf[32];
 	int l;
 	int pass;
-	char pbuf[1024];
+	char *pbuf;
 	const char *path;
 
 	if(bprm->envc == 0)
@@ -88,6 +88,11 @@ static int load_elf(struct linux_binprm *bprm
 	if(elf_ex->e_ident[EI_CLASS] != ELFCLASS64)
 		return -ENOEXEC;
 
+	pbuf = kmalloc(1024, GFP_ATOMIC);
+	if (!pbuf) {
+		printk("%s: error: allocating pbuf\n", __FUNCTION__);
+		return -ENOMEM;
+	}
 	path = d_path(&bprm->file->f_path, pbuf, 1024);
 	if(!path || IS_ERR(path))
 		path = bprm->interp;
@@ -96,8 +101,10 @@ static int load_elf(struct linux_binprm *bprm
 	if(!cp ||
 	   !strcmp(cp, "/mcexec") ||
 	   !strcmp(cp, "/ihkosctl") ||
-	   !strcmp(cp, "/ihkconfig"))
+	   !strcmp(cp, "/ihkconfig")) {
+		kfree(pbuf);
 		return -ENOEXEC;
+	}
 
 	cnt[0] = bprm->argc;
 	cnt[1] = bprm->envc;
@@ -124,8 +131,10 @@ static int load_elf(struct linux_binprm *bprm
 				                        bprm->p, 1, 0, 1,
 				                        &page, NULL);
 #endif
-				if(rc <= 0)
+				if(rc <= 0) {
+					kfree(pbuf);
 					return -EFAULT;
+				}
 				addr = kmap_atomic(page
 #if LINUX_VERSION_CODE < KERNEL_VERSION(3,4,0)
 				                   , KM_USER0
@@ -199,21 +208,27 @@ static int load_elf(struct linux_binprm *bprm
 	for(ep = env; ep->name; ep++)
 		if(ep->val)
 			kfree(ep->val);
-	if(rc)
+	if(rc) {
+		kfree(pbuf);
 		return -ENOEXEC;
+	}
 
 	file = open_exec(MCEXEC_PATH);
-	if (IS_ERR(file))
+	if (IS_ERR(file)) {
+		kfree(pbuf);
 		return -ENOEXEC;
+	}
 
 	rc = remove_arg_zero(bprm);
 	if (rc){
 		fput(file);
+		kfree(pbuf);
 		return rc;
 	}
 	rc = copy_strings_kernel(1, &bprm->interp, bprm);
 	if (rc < 0){
 		fput(file);
+		kfree(pbuf);
 		return rc; 
 	}
 	bprm->argc++;
@@ -221,12 +236,14 @@ static int load_elf(struct linux_binprm *bprm
 	rc = copy_strings_kernel(1, &wp, bprm);
 	if (rc){
 		fput(file);
+		kfree(pbuf);
 		return rc; 
 	}
 	bprm->argc++;
 	rc = bprm_change_interp(MCEXEC_PATH, bprm);
 	if (rc < 0){
 		fput(file);
+		kfree(pbuf);
 		return rc;
 	}
 
@@ -236,8 +253,12 @@ static int load_elf(struct linux_binprm *bprm
 
 	rc = prepare_binprm(bprm);
 	if (rc < 0){
+		kfree(pbuf);
 		return rc;
 	}
+
+	kfree(pbuf);
+
 	return search_binary_handler(bprm
 #if LINUX_VERSION_CODE < KERNEL_VERSION(3,8,0)
 	                             , regs
diff --git a/executer/kernel/mcctrl/control.c b/executer/kernel/mcctrl/control.c
index ddef075c..1bd2ffd8 100644
--- a/executer/kernel/mcctrl/control.c
+++ b/executer/kernel/mcctrl/control.c
@@ -77,32 +77,49 @@ int mcctrl_ikc_set_recv_cpu(ihk_os_t os, int cpu);
 static long mcexec_prepare_image(ihk_os_t os,
                                  struct program_load_desc * __user udesc)
 {
-	struct program_load_desc desc, *pdesc;
+	struct program_load_desc *desc, *pdesc;
 	struct ikc_scd_packet isp;
 	void *args, *envs;
 	long ret = 0;
 	struct mcctrl_usrdata *usrdata = ihk_host_os_get_usrdata(os);
 	struct mcctrl_per_proc_data *ppd = NULL;
+	int num_sections;
 
-	if (copy_from_user(&desc, udesc,
+	desc = kmalloc(sizeof(*desc), GFP_KERNEL);
+	if (!desc) {
+		printk("%s: error: allocating program_load_desc\n",
+			__FUNCTION__);
+		return -ENOMEM;
+	}
+
+	if (copy_from_user(desc, udesc,
 	                    sizeof(struct program_load_desc))) {
+		printk("%s: error: copying program_load_desc\n",
+			__FUNCTION__);
+		kfree(desc);
 		return -EFAULT;
 	}
-	if (desc.num_sections <= 0 || desc.num_sections > 16) {
-		printk("# of sections: %d\n", desc.num_sections);
+
+	num_sections = desc->num_sections;
+
+	if (num_sections <= 0 || num_sections > 16) {
+		printk("# of sections: %d\n", num_sections);
 		return -EINVAL;
 	}
 	pdesc = kmalloc(sizeof(struct program_load_desc) + 
 	                sizeof(struct program_image_section)
-	                * desc.num_sections, GFP_KERNEL);
-	memcpy(pdesc, &desc, sizeof(struct program_load_desc));
+	                * num_sections, GFP_KERNEL);
+	memcpy(pdesc, desc, sizeof(struct program_load_desc));
 	if (copy_from_user(pdesc->sections, udesc->sections,
 	                   sizeof(struct program_image_section)
-	                   * desc.num_sections)) {
+	                   * num_sections)) {
+		kfree(desc);
 		kfree(pdesc);
 		return -EFAULT;
 	}
 
+	kfree(desc);
+
 	pdesc->pid = task_tgid_vnr(current);
 
 	if (reserve_user_space(usrdata, &pdesc->user_start, &pdesc->user_end)) {
@@ -158,7 +175,7 @@ static long mcexec_prepare_image(ihk_os_t os,
 	ppd->rpgtable = pdesc->rpgtable;
 	
 	if (copy_to_user(udesc, pdesc, sizeof(struct program_load_desc) + 
-	             sizeof(struct program_image_section) * desc.num_sections)) {
+	             sizeof(struct program_image_section) * num_sections)) {
 		ret = -EFAULT;	
 		goto free_out;
 	}
@@ -315,33 +332,42 @@ static long mcexec_start_image(ihk_os_t os,
                                struct program_load_desc * __user udesc,
                                struct file *file)
 {
-	struct program_load_desc desc;
+	struct program_load_desc *desc;
 	struct ikc_scd_packet isp;
 	struct mcctrl_channel *c;
 	struct mcctrl_usrdata *usrdata = ihk_host_os_get_usrdata(os);
 	struct handlerinfo *info;
 
-	if (copy_from_user(&desc, udesc,
+	desc = kmalloc(sizeof(*desc), GFP_KERNEL);
+	if (!desc) {
+		printk("%s: error: allocating program_load_desc\n",
+			__FUNCTION__);
+		return -ENOMEM;
+	}
+
+	if (copy_from_user(desc, udesc,
 	                   sizeof(struct program_load_desc))) {
+		kfree(desc);
 		return -EFAULT;
 	}
 
 	info = kmalloc(sizeof(struct handlerinfo), GFP_KERNEL);
-	info->pid = desc.pid;
+	info->pid = desc->pid;
 	ihk_os_register_release_handler(file, release_handler, info);
 
-	c = usrdata->channels + desc.cpu;
+	c = usrdata->channels + desc->cpu;
 
-	mcctrl_ikc_set_recv_cpu(os, desc.cpu);
+	mcctrl_ikc_set_recv_cpu(os, desc->cpu);
 
-	usrdata->last_thread_exec = desc.cpu;
+	usrdata->last_thread_exec = desc->cpu;
 	
 	isp.msg = SCD_MSG_SCHEDULE_PROCESS;
-	isp.ref = desc.cpu;
-	isp.arg = desc.rprocess;
+	isp.ref = desc->cpu;
+	isp.arg = desc->rprocess;
 
-	mcctrl_ikc_send(os, desc.cpu, &isp);
+	mcctrl_ikc_send(os, desc->cpu, &isp);
 
+	kfree(desc);
 	return 0;
 }
 
@@ -502,7 +528,7 @@ int mcexec_syscall(struct mcctrl_usrdata *ud, struct ikc_scd_packet *packet)
 
 	if (unlikely(!ppd)) {
 		kprintf("%s: ERROR: no per-process structure for PID %d, "
-				"syscall nr: %d\n",
+				"syscall nr: %lu\n",
 				__FUNCTION__, pid, packet->req.number);
 		return -1;
 	}
diff --git a/executer/kernel/mcctrl/mcctrl.h b/executer/kernel/mcctrl/mcctrl.h
index 170479c7..d3405a38 100644
--- a/executer/kernel/mcctrl/mcctrl.h
+++ b/executer/kernel/mcctrl/mcctrl.h
@@ -317,7 +317,7 @@ inline struct mcctrl_per_thread_data *mcctrl_get_per_thread_data(
 void __return_syscall(ihk_os_t os, struct ikc_scd_packet *packet, 
 		long ret, int stid);
 
-#define PROCFS_NAME_MAX 1000
+#define PROCFS_NAME_MAX 768
 
 struct procfs_read {
 	unsigned long pbuf;	/* physical address of the host buffer (request) */
diff --git a/kernel/include/syscall.h b/kernel/include/syscall.h
index ae4c0c7f..d60cac26 100644
--- a/kernel/include/syscall.h
+++ b/kernel/include/syscall.h
@@ -331,7 +331,7 @@ void delete_proc_procfs_files(int pid);
 void create_os_procfs_files(void);
 void delete_os_procfs_files(void);
 
-#define PROCFS_NAME_MAX 1000
+#define PROCFS_NAME_MAX 768
 
 struct procfs_read {
 	unsigned long pbuf;	/* physical address of the host buffer (request) */