parasite: remove code which used for daemonized threads

Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

include/parasite-syscall.h

@@ -10,8 +10,6 @@ struct parasite_thread_ctl
 	pid_t			tid;
 	user_regs_struct_t	regs_orig;				/* original registers */
 
-	bool			daemonized;
-
 	k_rtsigset_t		sig_blocked;
 	bool			use_sig_blocked;
 
@@ -27,6 +25,8 @@ struct parasite_ctl {
 	void			*local_map;
 	unsigned long		map_length;
 
+	bool			daemonized;
+
 	unsigned long		parasite_ip;				/* service routine start ip */
 	unsigned long		syscall_ip;				/* entry point of infection */
 	u8			code_orig[BUILTIN_SYSCALL_SIZE];
@@ -52,11 +52,10 @@ extern int parasite_dump_itimers_seized(struct parasite_ctl *ctl, struct cr_fdse
 void *parasite_args_s(struct parasite_ctl *ctl, int args_size);
 int parasite_execute_daemon(unsigned int cmd, struct parasite_ctl *ctl);
 int parasite_send_fd(struct parasite_ctl *ctl, int fd);
-int __parasite_execute_daemon_by_id(unsigned int cmd,
-					struct parasite_ctl *ctl,
-					int id, bool wait_ack);
+int __parasite_execute_daemon(unsigned int cmd,
+				struct parasite_ctl *ctl, bool wait_ack);
 int __parasite_execute_daemon_wait_ack(unsigned int cmd,
-					struct parasite_ctl *ctl, int id);
+					struct parasite_ctl *ctl);
 
 struct parasite_dump_misc;
 struct vm_area_list;

include/parasite.h

@@ -51,17 +51,16 @@ enum {
 };
 
 struct ctl_msg {
-	unsigned int	id;			/* command recipient */
 	unsigned int	cmd;			/* command itself */
 	unsigned int	ack;			/* ack on command */
 	int		err;			/* error code on reply */
 };
 
-#define ctl_msg_cmd(_id, _cmd)		\
-	(struct ctl_msg){ .id = _id, .cmd = _cmd, }
+#define ctl_msg_cmd(_cmd)		\
+	(struct ctl_msg){.cmd = _cmd, }
 
-#define ctl_msg_ack(_id, _cmd, _err)	\
-	(struct ctl_msg){ .id = _id, .cmd = _cmd, .ack = _cmd, .err = _err, }
+#define ctl_msg_ack(_cmd, _err)	\
+	(struct ctl_msg){.cmd = _cmd, .ack = _cmd, .err = _err, }
 
 struct parasite_init_args {
 	int			id;

mem.c

@@ -373,14 +373,14 @@ static int __parasite_dump_pages_seized(struct parasite_ctl *ctl,
 		pr_debug("PPB: %d pages %d segs %u pipe %d off\n",
 				args->nr_pages, args->nr_segs, ppb->pipe_size, args->off);
 
-		ret = __parasite_execute_daemon_by_id(PARASITE_CMD_DUMPPAGES, ctl, 0, false);
+		ret = __parasite_execute_daemon(PARASITE_CMD_DUMPPAGES, ctl, false);
 		if (ret < 0)
 			goto out_pp;
 		ret = parasite_send_fd(ctl, ppb->p[1]);
 		if (ret)
 			goto out_pp;
 
-		ret = __parasite_execute_daemon_wait_ack(PARASITE_CMD_DUMPPAGES, ctl, 0);
+		ret = __parasite_execute_daemon_wait_ack(PARASITE_CMD_DUMPPAGES, ctl);
 		if (ret < 0)
 			goto out_pp;
 

parasite-syscall.c

@@ -253,7 +253,7 @@ static int __parasite_send_cmd(int sockfd, struct ctl_msg *m)
 
 	ret = send(sockfd, m, sizeof(*m), 0);
 	if (ret == -1) {
-		pr_perror("Failed to send command %d to daemon %d\n", m->cmd, m->id);
+		pr_perror("Failed to send command %d to daemon\n", m->cmd);
 		return -1;
 	} else if (ret != sizeof(*m)) {
 		pr_err("Message to daemon is trimmed (%d/%d)\n",
@@ -261,32 +261,32 @@ static int __parasite_send_cmd(int sockfd, struct ctl_msg *m)
 		return -1;
 	}
 
-	pr_debug("Sent msg to daemon %d %d %d %d\n", m->id, m->cmd, m->ack, m->err);
+	pr_debug("Sent msg to daemon %d %d %d\n", m->cmd, m->ack, m->err);
 	return 0;
 }
 
-static int parasite_wait_ack(int sockfd, int id, unsigned int cmd, struct ctl_msg *m)
+static int parasite_wait_ack(int sockfd, unsigned int cmd, struct ctl_msg *m)
 {
 	int ret;
 
-	pr_debug("Wait for ack %d-%d on daemon socket\n", id, cmd);
+	pr_debug("Wait for ack %d on daemon socket\n", cmd);
 
 	while (1) {
 		memzero(m, sizeof(*m));
 
 		ret = recv(sockfd, m, sizeof(*m), MSG_WAITALL);
 		if (ret == -1) {
-			pr_perror("Failed to read ack from %d", id);
+			pr_perror("Failed to read ack");
 			return -1;
 		} else if (ret != sizeof(*m)) {
 			pr_err("Message reply from daemon is trimmed (%d/%d)\n",
 			       (int)sizeof(*m), ret);
 			return -1;
 		}
-		pr_debug("Fetched ack: %d %d %d %d\n",
-			 m->id, m->cmd, m->ack, m->err);
+		pr_debug("Fetched ack: %d %d %d\n",
+			 m->cmd, m->ack, m->err);
 
-		if (m->id != id || m->cmd != cmd || m->ack != cmd) {
+		if (m->cmd != cmd || m->ack != cmd) {
 			pr_err("Communication error, this is not "
 			       "the ack we expected\n");
 			return -1;
@@ -298,46 +298,41 @@ static int parasite_wait_ack(int sockfd, int id, unsigned int cmd, struct ctl_ms
 }
 
 int __parasite_execute_daemon_wait_ack(unsigned int cmd,
-					struct parasite_ctl *ctl, int id)
+					struct parasite_ctl *ctl)
 {
 	struct ctl_msg m;
 
-	if (parasite_wait_ack(ctl->tsock, id, cmd, &m))
+	if (parasite_wait_ack(ctl->tsock, cmd, &m))
 		return -1;
 
 	if (m.err != 0) {
-		pr_err("Command %d for daemon %d failed with %d\n",
-		       cmd, id, m.err);
+		pr_err("Command %d for daemon failed with %d\n",
+		       cmd, m.err);
 		return -1;
 	}
 
 	return 0;
 }
 
-int __parasite_execute_daemon_by_id(unsigned int cmd,
-				struct parasite_ctl *ctl, int id, bool wait_ack)
+int __parasite_execute_daemon(unsigned int cmd,
+				struct parasite_ctl *ctl, bool wait_ack)
 {
 	struct ctl_msg m;
 
-	m = ctl_msg_cmd(id, cmd);
+	m = ctl_msg_cmd(cmd);
 	if (__parasite_send_cmd(ctl->tsock, &m))
 		return -1;
 
 	if (wait_ack)
-		return __parasite_execute_daemon_wait_ack(cmd, ctl, id);
+		return __parasite_execute_daemon_wait_ack(cmd, ctl);
 
 	return 0;
 }
 
-static int parasite_execute_daemon_by_id(unsigned int cmd,
-					struct parasite_ctl *ctl, int id)
+int parasite_execute_daemon(unsigned int cmd,
+					struct parasite_ctl *ctl)
 {
-	return __parasite_execute_daemon_by_id(cmd, ctl, id, true);
-}
-
-int parasite_execute_daemon(unsigned int cmd, struct parasite_ctl *ctl)
-{
-	return parasite_execute_daemon_by_id(cmd, ctl, 0);
+	return __parasite_execute_daemon(cmd, ctl, true);
 }
 
 static int munmap_seized(struct parasite_ctl *ctl, void *addr, size_t length)
@@ -493,13 +488,13 @@ static int parasite_daemonize(struct parasite_ctl *ctl, int id)
 
 	pr_info("Wait for parasite being daemonized...\n");
 
-	if (parasite_wait_ack(ctl->tsock, id, PARASITE_CMD_DAEMONIZE, &m)) {
+	if (parasite_wait_ack(ctl->tsock, PARASITE_CMD_DAEMONIZE, &m)) {
 		pr_err("Can't switch parasite %d to daemon mode %d\n",
 		       pid, m.err);
 		goto err;
 	}
 
-	thread->daemonized = true;
+	ctl->daemonized = true;
 	pr_info("Parasite %d has been switched to daemon mode\n", pid);
 	return 0;
 
@@ -684,8 +679,7 @@ int parasite_drain_fds_seized(struct parasite_ctl *ctl,
 	args = parasite_args_s(ctl, size);
 	memcpy(args, dfds, size);
 
-	ret = __parasite_execute_daemon_by_id(PARASITE_CMD_DRAIN_FDS, ctl,
-					       0, false);
+	ret = __parasite_execute_daemon(PARASITE_CMD_DRAIN_FDS, ctl, false);
 	if (ret) {
 		pr_err("Parasite failed to drain descriptors\n");
 		goto err;
@@ -695,7 +689,7 @@ int parasite_drain_fds_seized(struct parasite_ctl *ctl,
 	if (ret)
 		pr_err("Can't retrieve FDs from socket\n");
 
-	ret |= __parasite_execute_daemon_wait_ack(PARASITE_CMD_DRAIN_FDS, ctl, 0);
+	ret |= __parasite_execute_daemon_wait_ack(PARASITE_CMD_DRAIN_FDS, ctl);
 err:
 	return ret;
 }
@@ -823,8 +817,7 @@ int parasite_get_proc_fd_seized(struct parasite_ctl *ctl)
 {
 	int ret = -1, fd;
 
-	ret = __parasite_execute_daemon_by_id(PARASITE_CMD_GET_PROC_FD, ctl,
-					       0, false);
+	ret = __parasite_execute_daemon(PARASITE_CMD_GET_PROC_FD, ctl, false);
 	if (ret) {
 		pr_err("Parasite failed to get proc fd\n");
 		return ret;
@@ -833,7 +826,7 @@ int parasite_get_proc_fd_seized(struct parasite_ctl *ctl)
 	fd = recv_fd(ctl->tsock);
 	if (fd < 0)
 		pr_err("Can't retrieve FD from socket\n");
-	if (__parasite_execute_daemon_wait_ack(PARASITE_CMD_GET_PROC_FD, ctl, 0)) {
+	if (__parasite_execute_daemon_wait_ack(PARASITE_CMD_GET_PROC_FD, ctl)) {
 		close(fd);
 		return -1;
 	}
@@ -890,39 +883,34 @@ err:
 
 static int parasite_fini_seized(struct parasite_ctl *ctl)
 {
-	int status, ret = 0, i, nr = 0, nr_dmnz = 0;
-
-	/* Start to trace syscalls for each thread */
-	for (i = 0; i < ctl->nr_threads; i++) {
-		pid_t pid = ctl->threads[i].tid;
-
-		if (!ctl->threads[i].daemonized)
-			break;
+	pid_t pid = ctl->pid.real;
+	int status, ret = 0;;
 
-		ptrace(PTRACE_INTERRUPT, pid, NULL, NULL);
+	if (!ctl->daemonized)
+		return 0;
 
-		pr_debug("Waiting for %d to trap\n", pid);
-		if (wait4(pid, &status, __WALL, NULL) != pid) {
-			pr_perror("Waited pid mismatch (pid: %d)", pid);
-			return -1;
-		}
+	/* Start to trace syscalls for each thread */
+	ptrace(PTRACE_INTERRUPT, pid, NULL, NULL);
 
-		pr_debug("Daemon %d exited trapping\n", pid);
-		if (!WIFSTOPPED(status)) {
-			pr_err("Task is still running (pid: %d)\n", pid);
-			return -1;
-		}
+	pr_debug("Waiting for %d to trap\n", pid);
+	if (wait4(pid, &status, __WALL, NULL) != pid) {
+		pr_perror("Waited pid mismatch (pid: %d)", pid);
+		return -1;
+	}
 
-		ret = ptrace(PTRACE_SYSCALL, pid, NULL, NULL);
-		if (ret) {
-			pr_perror("ptrace");
-			return -1;
-		}
+	pr_debug("Daemon %d exited trapping\n", pid);
+	if (!WIFSTOPPED(status)) {
+		pr_err("Task is still running (pid: %d)\n", pid);
+		return -1;
+	}
 
-		nr_dmnz++;
+	ret = ptrace(PTRACE_SYSCALL, pid, NULL, NULL);
+	if (ret) {
+		pr_perror("ptrace");
+		return -1;
 	}
 
-	ret = __parasite_execute_daemon_by_id(PARASITE_CMD_FINI, ctl, 0, false);
+	ret = __parasite_execute_daemon(PARASITE_CMD_FINI, ctl, false);
 	if (ret)
 		return -1;
 
@@ -950,11 +938,8 @@ static int parasite_fini_seized(struct parasite_ctl *ctl)
 
 		pr_debug("%d is going to execute the syscall %lx\n", pid, regs.orig_ax);
 		if (regs.orig_ax == __NR_rt_sigreturn) {
-			nr++;
 			pr_debug("%d was stopped\n", pid);
-			if (nr == nr_dmnz)
-				break;
-			continue;
+			break;
 		}
 
 		ret = ptrace(PTRACE_SYSCALL, pid, NULL, NULL);
@@ -964,31 +949,23 @@ static int parasite_fini_seized(struct parasite_ctl *ctl)
 		}
 	}
 
-	/* Stop all threads on the exit point from sys_rt_sigreturn */
-	for (i = 0; i < ctl->nr_threads; i++) {
-		pid_t pid = ctl->threads[i].tid;
-
-		if (!ctl->threads[i].daemonized)
-			break;
-
-		ctl->threads[i].use_sig_blocked = false;
+	ctl->threads[0].use_sig_blocked = false;
 
-		ret = ptrace(PTRACE_SYSCALL, pid, NULL, NULL);
-		if (ret) {
-			pr_perror("ptrace");
-			return -1;
-		}
+	ret = ptrace(PTRACE_SYSCALL, pid, NULL, NULL);
+	if (ret) {
+		pr_perror("ptrace");
+		return -1;
+	}
 
-		if (wait4(pid, &status, __WALL, NULL) != pid) {
-			pr_perror("wait4 failed");
-			return -1;
-		}
+	if (wait4(pid, &status, __WALL, NULL) != pid) {
+		pr_perror("wait4 failed");
+		return -1;
+	}
 
-		pr_debug("Trap %d\n", pid);
-		if (!WIFSTOPPED(status)) {
-			pr_err("%d\n", status);
-			return -1;
-		}
+	pr_debug("Trap %d\n", pid);
+	if (!WIFSTOPPED(status)) {
+		pr_err("%d\n", status);
+		return -1;
 	}
 
 	return ret;

pie/parasite.c

@@ -20,22 +20,7 @@
 
 static int tsock = -1;
 
-static struct tid_state_s {
-	int		id;
-
-	futex_t		cmd;
-	int		ret;
-
-	struct rt_sigframe *sigframe;
-} *tid_state;
-
-static unsigned int nr_tid_state;
-static unsigned int next_tid_state;
-
-#define TID_STATE_SIZE(n)	\
-	(ALIGN(sizeof(struct tid_state_s) * n, PAGE_SIZE))
-
-#define thread_leader	(&tid_state[0])
+static struct rt_sigframe *sigframe;
 
 #ifndef SPLICE_F_GIFT
 #define SPLICE_F_GIFT	0x08
@@ -197,12 +182,6 @@ static int init_daemon_thread(struct parasite_init_args *args)
 	k_rtsigset_t to_block;
 	int ret;
 
-	if (args->id != next_tid_state)
-		return -EINVAL;
-
-	if (next_tid_state >= nr_tid_state)
-		return -ENOMEM;
-
 	ksigfillset(&to_block);
 	ret = sys_sigprocmask(SIG_SETMASK, &to_block,
 			      &args->sig_blocked,
@@ -210,12 +189,7 @@ static int init_daemon_thread(struct parasite_init_args *args)
 	if (ret)
 		return -1;
 
-	tid_state[next_tid_state].id = next_tid_state;
-	tid_state[next_tid_state].sigframe = args->sigframe;
-
-	futex_set(&tid_state[next_tid_state].cmd, PARASITE_CMD_IDLE);
-
-	next_tid_state++;
+	sigframe = args->sigframe;
 
 	return ret;
 }
@@ -254,45 +228,10 @@ static int fini_thread(struct parasite_dump_thread *args)
 				NULL, sizeof(k_rtsigset_t));
 }
 
-static void __parasite_daemon_thread_ack(struct tid_state_s *s, int ret)
-{
-	s->ret = ret;
-	futex_set_and_wake(&s->cmd, PARASITE_CMD_IDLE);
-}
-
-static int fini_daemon_thread(struct tid_state_s *s)
-{
-	unsigned long new_sp;
-
-	new_sp = (long)s->sigframe + SIGFRAME_OFFSET;
-	pr_debug("%ld: new_sp=%lx ip %lx\n", sys_gettid(),
-		 new_sp, s->sigframe->uc.uc_mcontext.rip);
-
-	__parasite_daemon_thread_ack(s, 0);
-
-	ARCH_RT_SIGRETURN(new_sp);
-
-	BUG();
-
-	return 0;
-}
-
 static int init(struct parasite_init_args *args)
 {
 	int ret;
 
-	if (!args->nr_threads)
-		return -EINVAL;
-
-	tid_state = (void *)sys_mmap(NULL, TID_STATE_SIZE(args->nr_threads),
-				     PROT_READ | PROT_WRITE,
-				     MAP_PRIVATE | MAP_ANONYMOUS,
-				     -1, 0);
-	if ((unsigned long)tid_state > TASK_SIZE)
-		return -ENOMEM;
-
-	nr_tid_state = args->nr_threads;
-
 	ret = init_daemon_thread(args);
 	if (ret < 0)
 		return ret;
@@ -459,12 +398,12 @@ static int parasite_check_vdso_mark(struct parasite_vdso_vma_entry *args)
 	return 0;
 }
 
-static int __parasite_daemon_reply_ack(unsigned int id, unsigned int cmd, int err)
+static int __parasite_daemon_reply_ack(unsigned int cmd, int err)
 {
 	struct ctl_msg m;
 	int ret;
 
-	m = ctl_msg_ack(id, cmd, err);
+	m = ctl_msg_ack(cmd, err);
 	ret = sys_sendto(tsock, &m, sizeof(m), 0, NULL, 0);
 	if (ret != sizeof(m)) {
 		pr_err("Sent only %d bytes while %d expected\n",
@@ -472,8 +411,8 @@ static int __parasite_daemon_reply_ack(unsigned int id, unsigned int cmd, int er
 		return -1;
 	}
 
-	pr_debug("__sent ack msg: %d %d %d %d\n",
-		 m.id, m.cmd, m.ack, m.err);
+	pr_debug("__sent ack msg: %d %d %d\n",
+		 m.cmd, m.ack, m.err);
 
 	return 0;
 }
@@ -493,88 +432,25 @@ static int __parasite_daemon_wait_msg(struct ctl_msg *m)
 			return 0;
 		}
 
-		pr_debug("__fetched msg: %d %d %d %d\n",
-			 m->id, m->cmd, m->ack, m->err);
+		pr_debug("__fetched msg: %d %d %d\n",
+			 m->cmd, m->ack, m->err);
 		return 0;
 	}
 
 	return -1;
 }
 
-static int __parasite_daemon_thread_wait_cmd(struct tid_state_s *s)
-{
-	futex_wait_while_eq(&s->cmd, PARASITE_CMD_IDLE);
-	return futex_get(&s->cmd);
-}
-
-static void noinline __used
-__parasite_daemon_thread(void *args, struct tid_state_s *s)
-{
-	pr_debug("Running daemon thread %d\n", s->id);
-
-	/* Reply we're alive */
-	if (__parasite_daemon_reply_ack(s->id, PARASITE_CMD_DAEMONIZE, 0))
-		return;
-
-	while (1) {
-		int ret, cmd;
-
-		cmd = __parasite_daemon_thread_wait_cmd(s);
-
-		pr_debug("Command %d in daemon thread %d\n", cmd, s->id);
-
-		switch (cmd) {
-		case PARASITE_CMD_DUMP_THREAD:
-			ret = dump_thread(args);
-			break;
-		case PARASITE_CMD_FINI_THREAD:
-			fini_daemon_thread(s);
-			return;
-		default:
-			pr_err("Unknown command in parasite daemon thread: %d\n", cmd);
-			ret = -1;
-			break;
-		}
-		__parasite_daemon_thread_ack(s, ret);
-	}
-
-	pr_err("The thread %d trys to escape!!!", s->id);
-	BUG();
-	return;
-}
-
-static int __parasite_execute_thread(struct ctl_msg *m)
-{
-	struct tid_state_s *s = &tid_state[m->id];
-
-	pr_debug("Wake thread %d daemon with command %d\n", s->id, m->cmd);
-	futex_set_and_wake(&s->cmd, m->cmd);
-
-	pr_debug("Wait thread %d for PARASITE_CMD_IDLE\n", s->id);
-	futex_wait_until(&s->cmd, PARASITE_CMD_IDLE);
-
-	return s->ret;
-}
-
-static int fini(struct tid_state_s *s)
+static int fini()
 {
 	unsigned long new_sp;
-	int i;
 
-	for (i = 1; i < next_tid_state; i++) {
-		struct ctl_msg m = {.cmd = PARASITE_CMD_FINI_THREAD, .id = i};
-		__parasite_execute_thread(&m);
-	}
-
-	new_sp = (long)s->sigframe + SIGFRAME_OFFSET;
+	new_sp = (long)sigframe + SIGFRAME_OFFSET;
 	pr_debug("%ld: new_sp=%lx ip %lx\n", sys_gettid(),
-		  new_sp, s->sigframe->uc.uc_mcontext.rip);
+		  new_sp, sigframe->uc.uc_mcontext.rip);
 
 	sys_close(tsock);
 	log_set_fd(-1);
 
-	sys_munmap(tid_state, TID_STATE_SIZE(nr_tid_state));
-
 	ARCH_RT_SIGRETURN(new_sp);
 
 	BUG();
@@ -582,8 +458,7 @@ static int fini(struct tid_state_s *s)
 	return -1;
 }
 
-static void noinline __used
-__parasite_daemon_thread_leader(void *args, struct tid_state_s *s)
+static noinline __used int noinline parasite_daemon(void *args)
 {
 	struct ctl_msg m = { };
 	int ret = -1;
@@ -591,7 +466,7 @@ __parasite_daemon_thread_leader(void *args, struct tid_state_s *s)
 	pr_debug("Running daemon thread leader\n");
 
 	/* Reply we're alive */
-	if (__parasite_daemon_reply_ack(0, PARASITE_CMD_DAEMONIZE, 0))
+	if (__parasite_daemon_reply_ack(PARASITE_CMD_DAEMONIZE, 0))
 		goto out;
 
 	while (1) {
@@ -600,17 +475,14 @@ __parasite_daemon_thread_leader(void *args, struct tid_state_s *s)
 
 		switch (m.cmd) {
 		case PARASITE_CMD_FINI:
-			ret = fini(s);
+			ret = fini();
 			sys_close(tsock);
 			/*
 			 * No ACK here since we're getting out.
 			 */
 			break;
-		case PARASITE_CMD_FINI_THREAD:
-			ret = __parasite_execute_thread(&m);
-			break;
 		case PARASITE_CMD_DUMP_THREAD:
-			ret = __parasite_execute_thread(&m);
+			ret = dump_thread(args);
 			break;
 		case PARASITE_CMD_DUMPPAGES:
 			ret = dump_pages(args);
@@ -648,31 +520,12 @@ __parasite_daemon_thread_leader(void *args, struct tid_state_s *s)
 			break;
 		}
 
-		if (__parasite_daemon_reply_ack(m.id, m.cmd, ret))
+		if (__parasite_daemon_reply_ack(m.cmd, ret))
 			break;
 	}
 
 out:
-	fini(&tid_state[0]);
-
-	return;
-}
-
-static int noinline parasite_daemon(struct parasite_init_args *args)
-{
-	struct tid_state_s *s;
-	bool is_leader = (args->id == 0);
-
-	s = &tid_state[args->id];
-
-	pr_info("Parasite entering daemon mode for %d\n", s->id);
-
-	if (is_leader)
-		__parasite_daemon_thread_leader(args, s);
-	else
-		__parasite_daemon_thread(args, s);
-
-	pr_info("Parasite leaving daemon mode for %d\n", s->id);
+	fini();
 
 	return 0;
 }