diff --git a/arch/x86/kernel/include/syscall_list.h b/arch/x86/kernel/include/syscall_list.h
index 505cd03b..5b88646e 100644
--- a/arch/x86/kernel/include/syscall_list.h
+++ b/arch/x86/kernel/include/syscall_list.h
@@ -61,11 +61,14 @@ SYSCALL_HANDLED(97, getrlimit)
 SYSCALL_HANDLED(101, ptrace)
 SYSCALL_DELEGATED(102, getuid)
 SYSCALL_DELEGATED(104, getgid)
+SYSCALL_HANDLED(105, setuid)
 SYSCALL_DELEGATED(107, geteuid)
 SYSCALL_DELEGATED(108, getegid)
 SYSCALL_HANDLED(109, setpgid)
 SYSCALL_HANDLED(110, getppid)
 SYSCALL_DELEGATED(111, getpgrp)
+SYSCALL_HANDLED(113, setreuid)
+SYSCALL_HANDLED(117, setresuid)
 SYSCALL_HANDLED(127, rt_sigpending)
 SYSCALL_HANDLED(128, rt_sigtimedwait)
 SYSCALL_HANDLED(129, rt_sigqueueinfo)
diff --git a/arch/x86/kernel/syscall.c b/arch/x86/kernel/syscall.c
index 5873b1cb..f897f69d 100644
--- a/arch/x86/kernel/syscall.c
+++ b/arch/x86/kernel/syscall.c
@@ -932,6 +932,17 @@ do_kill(int pid, int tid, int sig, siginfo_t *info, int ptracecont)
 		return 0;
 	}
 
+	if(sig != SIGCONT &&
+	   proc->ftn->euid != 0 &&
+	   proc->ftn->ruid != tproc->ftn->ruid &&
+	   proc->ftn->euid != tproc->ftn->ruid &&
+	   proc->ftn->ruid != tproc->ftn->suid &&
+	   proc->ftn->euid != tproc->ftn->suid){
+		ihk_mc_spinlock_unlock_noirq(savelock);
+		cpu_restore_interrupt(irqstate);
+		return -EPERM;
+	}
+
 	doint = 0;
 	if(tid == -1){
 		ihk_mc_spinlock_lock_noirq(&tproc->sigshared->lock);
diff --git a/executer/include/uprotocol.h b/executer/include/uprotocol.h
index a3181d8c..e79a3d76 100644
--- a/executer/include/uprotocol.h
+++ b/executer/include/uprotocol.h
@@ -80,6 +80,9 @@ struct program_load_desc {
 	int err;
 	int stack_prot;
 	int pgid;
+	int ruid;
+	int euid;
+	int suid;
 	unsigned long entry;
 	unsigned long user_start;
 	unsigned long user_end;
diff --git a/executer/user/mcexec.c b/executer/user/mcexec.c
index 50741229..cce5e4ab 100644
--- a/executer/user/mcexec.c
+++ b/executer/user/mcexec.c
@@ -150,6 +150,9 @@ struct program_load_desc *load_elf(FILE *fp, char **interp_pathp)
 	int load_addr_set = 0;
 	static char interp_path[PATH_MAX];
 	ssize_t ss;
+	uid_t ruid;
+	uid_t euid;
+	uid_t suid;
 
 	*interp_pathp = NULL;
 
@@ -233,6 +236,10 @@ struct program_load_desc *load_elf(FILE *fp, char **interp_pathp)
 	}
 	desc->pid = getpid();
 	desc->pgid = getpgid(0);
+	getresuid(&ruid, &euid, &suid);
+	desc->ruid = ruid;
+	desc->euid = euid;
+	desc->suid = suid;
 	desc->entry = hdr.e_entry;
 
 	desc->at_phdr = load_addr + hdr.e_phoff;
diff --git a/kernel/host.c b/kernel/host.c
index 037eb1c6..61d06b85 100644
--- a/kernel/host.c
+++ b/kernel/host.c
@@ -349,6 +349,9 @@ static int process_msg_prepare_process(unsigned long rphys)
 	}
 	proc->ftn->pid = pn->pid;
 	proc->ftn->pgid = pn->pgid;
+	proc->ftn->ruid = pn->ruid;
+	proc->ftn->euid = pn->euid;
+	proc->ftn->suid = pn->suid;
 	proc->vm->region.user_start = pn->user_start;
 	proc->vm->region.user_end = pn->user_end;
 	proc->vm->region.map_start = (USER_END / 3) & LARGE_PAGE_MASK;
diff --git a/kernel/include/process.h b/kernel/include/process.h
index f4a5cae2..a0377975 100644
--- a/kernel/include/process.h
+++ b/kernel/include/process.h
@@ -279,6 +279,9 @@ struct fork_tree_node {
 	int pid;
 	int tid;
 	int pgid;
+	int ruid;
+	int euid;
+	int suid;
 	
 	struct fork_tree_node *parent;
 	struct list_head children;
diff --git a/kernel/include/syscall.h b/kernel/include/syscall.h
index 483805bf..c9095099 100644
--- a/kernel/include/syscall.h
+++ b/kernel/include/syscall.h
@@ -140,6 +140,9 @@ struct program_load_desc {
 	int err;
 	int stack_prot;
 	int pgid;
+	int ruid;
+	int euid;
+	int suid;
 	unsigned long entry;
 	unsigned long user_start;
 	unsigned long user_end;
diff --git a/kernel/process.c b/kernel/process.c
index 41abcf0a..4a1e5ded 100644
--- a/kernel/process.c
+++ b/kernel/process.c
@@ -106,6 +106,10 @@ void init_fork_tree_node(struct fork_tree_node *ftn,
 	ftn->parent = NULL;
 	if (parent) {
 		ftn->parent = parent;
+		ftn->pgid = parent->pgid;
+		ftn->ruid = parent->ruid;
+		ftn->euid = parent->euid;
+		ftn->suid = parent->suid;
 	}
 	INIT_LIST_HEAD(&ftn->children);
 	INIT_LIST_HEAD(&ftn->siblings_list);
diff --git a/kernel/syscall.c b/kernel/syscall.c
index 872febe4..89e129f0 100644
--- a/kernel/syscall.c
+++ b/kernel/syscall.c
@@ -104,6 +104,7 @@ int copy_to_user(void *, const void *, size_t);
 int patch_process_vm(struct process_vm *, void *, const void *, size_t);
 void do_setpgid(int, int);
 extern long alloc_debugreg(struct process *proc);
+extern int num_processors;
 
 int prepare_process_ranges_args_envs(struct process *proc, 
 		struct program_load_desc *pn,
@@ -1871,8 +1872,6 @@ unsigned long do_fork(int clone_flags, unsigned long newsp,
 		return -ENOMEM;
 	}
 
-	new->ftn->pgid = cpu_local_var(current)->ftn->pgid;
-
 	cpu_set(cpuid, &new->vm->cpu_set, &new->vm->cpu_set_lock);
 
 	if (clone_flags & CLONE_VM) {
@@ -2034,6 +2033,91 @@ SYSCALL_DECLARE(tgkill)
 	return do_kill(tgid, tid, sig, &info, 0);
 }
 
+void
+do_setresuid(int ruid, int euid, int suid)
+{
+	struct process *proc = cpu_local_var(current);
+	int pid = proc->ftn->pid;
+	struct cpu_local_var *v;
+	struct process *p;
+	int i;
+	unsigned long irqstate;
+
+	for(i = 0; i < num_processors; i++){
+		v = get_cpu_local_var(i);
+		irqstate = ihk_mc_spinlock_lock(&(v->runq_lock));
+		list_for_each_entry(p, &(v->runq), sched_list){
+			if(p->ftn->pid == pid){
+				if(ruid != -1)
+					p->ftn->ruid = ruid;
+				if(euid != -1)
+					p->ftn->euid = euid;
+				if(suid != -1)
+					p->ftn->suid = suid;
+			}
+		}
+		ihk_mc_spinlock_unlock(&(v->runq_lock), irqstate);
+	}
+}
+
+SYSCALL_DECLARE(setresuid)
+{
+	int ruid = ihk_mc_syscall_arg0(ctx);
+	int euid = ihk_mc_syscall_arg1(ctx);
+	int suid = ihk_mc_syscall_arg2(ctx);
+	int rc;
+
+	rc = syscall_generic_forwarding(__NR_setresuid, ctx);
+	if(rc == 0){
+		do_setresuid(ruid, euid, suid);
+	}
+	return rc;
+}
+
+SYSCALL_DECLARE(setreuid)
+{
+	int ruid = ihk_mc_syscall_arg0(ctx);
+	int euid = ihk_mc_syscall_arg1(ctx);
+	int suid = -1;
+	int rc;
+	struct process *proc = cpu_local_var(current);
+//	int euid_bak = proc->ftn->euid;
+	int ruid_bak = proc->ftn->ruid;
+
+	rc = syscall_generic_forwarding(__NR_setreuid, ctx);
+	if(rc == 0){
+		if(euid != -1){
+			if(euid != ruid_bak){
+				suid = euid;
+			}
+		}
+		else if(ruid != -1){
+		}
+		do_setresuid(ruid, euid, suid);
+	}
+	return rc;
+}
+
+SYSCALL_DECLARE(setuid)
+{
+	int euid = ihk_mc_syscall_arg0(ctx);
+	int ruid = -1;
+	int suid = -1;
+	long rc;
+	struct process *proc = cpu_local_var(current);
+	int euid_bak = proc->ftn->euid;
+
+	rc = syscall_generic_forwarding(__NR_setuid, ctx);
+	if(rc == 0){
+		if(euid_bak == 0){
+			ruid = euid;
+			suid = euid;
+		}
+		do_setresuid(ruid, euid, suid);
+	}
+	return rc;
+}
+
 SYSCALL_DECLARE(setpgid)
 {
 	int pid = ihk_mc_syscall_arg0(ctx);