dump: Return signal mask from parasite on initialization

This mask should be put into sigframe (used by parasite, coming
soon) thus we have to pull one from dumpee early.

Plus, check that signals are blocked for each thread separately
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

arch/arm/crtools.c

@@ -78,7 +78,7 @@ int syscall_seized(struct parasite_ctl *ctl, int nr, unsigned long *ret,
 
 	parasite_setup_regs(ctl->syscall_ip, 0, &regs);
 	err = __parasite_execute_trap(ctl, ctl->pid.real, &regs,
-					&ctl->threads[0].regs_orig);
+					&ctl->threads[0].regs_orig, 0);
 	if (err)
 		return err;
 

arch/x86/crtools.c

@@ -102,7 +102,7 @@ int syscall_seized(struct parasite_ctl *ctl, int nr, unsigned long *ret,
 
 	parasite_setup_regs(ctl->syscall_ip, 0, &regs);
 	err = __parasite_execute_trap(ctl, ctl->pid.real, &regs,
-					&ctl->threads[0].regs_orig);
+					&ctl->threads[0].regs_orig, 0);
 	if (err)
 		return err;
 

cr-dump.c

@@ -655,8 +655,6 @@ static int dump_task_core_all(struct parasite_ctl *ctl,
 
 	strncpy((char *)core->tc->comm, stat->comm, TASK_COMM_LEN);
 	core->tc->flags = stat->flags;
-	BUILD_BUG_ON(sizeof(core->tc->blk_sigset) != sizeof(k_rtsigset_t));
-	memcpy(&core->tc->blk_sigset, &misc->blocked, sizeof(k_rtsigset_t));
 
 	core->tc->task_state = TASK_ALIVE;
 	core->tc->exit_code = 0;
@@ -1080,10 +1078,10 @@ static int collect_file_locks(void)
 static int dump_task_thread(struct parasite_ctl *parasite_ctl,
 				const struct pstree_item *item, int id)
 {
-	int ret = -1, fd_core;
 	struct pid *tid = &item->threads[id];
 	CoreEntry *core = item->core[id];
 	pid_t pid = tid->real;
+	int ret = -1, fd_core;
 
 	pr_info("\n");
 	pr_info("Dumping core for thread (pid: %d)\n", pid);
@@ -1099,8 +1097,6 @@ static int dump_task_thread(struct parasite_ctl *parasite_ctl,
 		goto err;
 	}
 
-	core->thread_core->has_blk_sigset = true;
-
 	ret = dump_sched_info(pid, core->thread_core);
 	if (ret)
 		goto err;

include/parasite-syscall.h

@@ -12,6 +12,9 @@ struct parasite_thread_ctl
 
 	bool			daemonized;
 
+	k_rtsigset_t		sig_blocked;
+	bool			use_sig_blocked;
+
 	void			*rstack;
 };
 
@@ -26,8 +29,6 @@ struct parasite_ctl {
 	unsigned long		syscall_ip;				/* entry point of infection */
 	u8			code_orig[BUILTIN_SYSCALL_SIZE];
 
-	int			signals_blocked;
-
 	unsigned int		*addr_cmd;				/* addr for command */
 	void			*addr_args;				/* address for arguments */
 	unsigned long		args_size;
@@ -102,7 +103,8 @@ int syscall_seized(struct parasite_ctl *ctl, int nr, unsigned long *ret,
 
 extern int __parasite_execute_trap(struct parasite_ctl *ctl, pid_t pid,
 					user_regs_struct_t *regs,
-					user_regs_struct_t *regs_orig);
+					user_regs_struct_t *regs_orig,
+					bool signals_blocked);
 extern bool arch_can_dump_task(pid_t pid);
 
 extern int parasite_fixup_vdso(struct parasite_ctl *ctl, pid_t pid,

include/parasite.h

@@ -73,6 +73,8 @@ struct parasite_init_args {
 	struct sockaddr_un	p_addr;
 
 	int			nr_threads;
+
+	k_rtsigset_t		sig_blocked;
 };
 
 struct parasite_log_args {
@@ -128,7 +130,6 @@ struct parasite_dump_itimers_args {
 
 struct parasite_dump_misc {
 	unsigned long		brk;
-	k_rtsigset_t		blocked;
 
 	u32 pid;
 	u32 sid;

parasite-syscall.c

@@ -65,7 +65,8 @@ static struct vma_area *get_vma_by_ip(struct list_head *vma_area_list, unsigned
 /* we run at @regs->ip */
 int __parasite_execute_trap(struct parasite_ctl *ctl, pid_t pid,
 				user_regs_struct_t *regs,
-				user_regs_struct_t *regs_orig)
+				user_regs_struct_t *regs_orig,
+				bool signals_blocked)
 {
 	siginfo_t siginfo;
 	int status;
@@ -112,7 +113,7 @@ retry_signal:
 		pr_debug("** delivering signal %d si_code=%d\n",
 			 siginfo.si_signo, siginfo.si_code);
 
-		if (ctl->signals_blocked) {
+		if (signals_blocked) {
 			pr_err("Unexpected %d task interruption, aborting\n", pid);
 			goto err;
 		}
@@ -210,7 +211,8 @@ static int parasite_execute_trap_by_id(unsigned int cmd, struct parasite_ctl *ct
 
 	parasite_setup_regs(ctl->parasite_ip, thread->rstack, &regs);
 
-	ret = __parasite_execute_trap(ctl, pid, &regs, &thread->regs_orig);
+	ret = __parasite_execute_trap(ctl, pid, &regs, &thread->regs_orig,
+					thread->use_sig_blocked);
 	if (ret == 0)
 		ret = (int)REG_RES(regs);
 
@@ -432,6 +434,9 @@ static int parasite_init(struct parasite_ctl *ctl, pid_t pid, int nr_threads)
 		goto err;
 	}
 
+	ctl->threads[0].sig_blocked = args->sig_blocked;
+	ctl->threads[0].use_sig_blocked = true;
+
 	if (connect(sock, (struct sockaddr *)&args->p_addr, args->p_addr_len) < 0) {
 		pr_perror("Can't connect a transport socket");
 		goto err;
@@ -498,7 +503,6 @@ int parasite_dump_thread_seized(struct parasite_ctl *ctl, int id,
 
 	ret = parasite_execute_daemon_by_id(PARASITE_CMD_DUMP_THREAD, ctl, id);
 
-	memcpy(&core->thread_core->blk_sigset, &args->blocked, sizeof(args->blocked));
 	CORE_THREAD_ARCH_INFO(core)->clear_tid_addr = encode_pointer(args->tid_addr);
 	tid->virt = args->tid;
 	core_put_tls(core, args->tls);
@@ -820,6 +824,9 @@ int parasite_init_threads_seized(struct parasite_ctl *ctl, struct pstree_item *i
 			goto err;
 		}
 
+		ctl->threads[i].sig_blocked = args->sig_blocked;
+		ctl->threads[i].use_sig_blocked = true;
+
 		if (parasite_daemonize(ctl, i))
 			goto err;
 	}
@@ -911,7 +918,6 @@ int parasite_cure_remote(struct parasite_ctl *ctl)
 	int ret = 0;
 
 	if (ctl->parasite_ip) {
-		ctl->signals_blocked = 0;
 		ret = parasite_fini_threads_seized(ctl);
 		parasite_fini_seized(ctl);
 	}
@@ -1122,8 +1128,6 @@ struct parasite_ctl *parasite_infect_seized(pid_t pid, struct pstree_item *item,
 		goto err_restore;
 	}
 
-	ctl->signals_blocked = 1;
-
 	ret = parasite_set_logfd(ctl, pid);
 	if (ret) {
 		pr_err("%d: Can't set a logging descriptor\n", pid);
@@ -1137,6 +1141,19 @@ struct parasite_ctl *parasite_infect_seized(pid_t pid, struct pstree_item *item,
 	if (ret)
 		goto err_restore;
 
+	for (i = 0; i < item->nr_threads; i++) {
+		struct parasite_thread_ctl *thread = &ctl->threads[i];
+
+		if (i == 0)
+			memcpy(&item->core[i]->tc->blk_sigset,
+				&thread->sig_blocked, sizeof(k_rtsigset_t));
+		else {
+			memcpy(&item->core[i]->thread_core->blk_sigset,
+				&thread->sig_blocked, sizeof(k_rtsigset_t));
+			item->core[i]->thread_core->has_blk_sigset = true;
+		}
+	}
+
 	return ctl;
 
 err_restore:

pie/parasite.c

@@ -120,7 +120,6 @@ static int dump_itimers(struct parasite_dump_itimers_args *args)
 static int dump_misc(struct parasite_dump_misc *args)
 {
 	args->brk = sys_brk(0);
-	args->blocked = thread_leader->sig_blocked;
 
 	args->pid = sys_getpid();
 	args->sid = sys_getsid();
@@ -179,18 +178,13 @@ static int drain_fds(struct parasite_drain_fd *args)
 
 static int dump_thread(struct parasite_dump_thread *args)
 {
-	struct tid_state_s *s = &tid_state[args->id];
 	pid_t tid = sys_gettid();
 	int ret;
 
-	if (!s->use_sig_blocked)
-		return -EINVAL;
-
 	ret = sys_prctl(PR_GET_TID_ADDRESS, (unsigned long) &args->tid_addr, 0, 0, 0);
 	if (ret)
 		return ret;
 
-	args->blocked = s->sig_blocked;
 	args->tid = tid;
 	args->tls = arch_get_tls();
 
@@ -212,8 +206,11 @@ static int init_thread(struct parasite_init_args *args)
 	ret = sys_sigprocmask(SIG_SETMASK, &to_block,
 			      &tid_state[next_tid_state].sig_blocked,
 			      sizeof(k_rtsigset_t));
-	if (ret >= 0)
-		tid_state[next_tid_state].use_sig_blocked = true;
+	if (ret)
+		return -1;
+
+	tid_state[next_tid_state].use_sig_blocked = true;
+	args->sig_blocked = tid_state[next_tid_state].sig_blocked;
 
 	tid_state[next_tid_state].id = next_tid_state;