fd: Handle close-on-exec bits

This bit is not per-file, but per-fd, thus put it on the fdinfo_entry.
Draing these bits from parasite together with the fds themselves, save
into image and restore with fcntl F_SETFD cmd where applicable.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

cr-dump.c

@@ -305,6 +305,7 @@ static int do_dump_gen_file(const struct fd_parms *p, int lfd,
 	e.type	= p->type;
 	e.fd	= p->fd;
 	e.id	= p->id;
+	e.flags = p->fd_flags;
 
 	ret = fd_id_generate(p->pid, &e);
 	if (ret == 1) /* new ID generated */
@@ -368,7 +369,7 @@ static int dump_task_exe_link(pid_t pid, struct mm_entry *mm)
 	return ret;
 }
 
-static int fill_fd_params(pid_t pid, int fd, int lfd, struct fd_parms *p)
+static int fill_fd_params(pid_t pid, int fd, int lfd, char fd_flags, struct fd_parms *p)
 {
 	if (fstat(lfd, &p->stat) < 0) {
 		pr_perror("Can't stat fd %d\n", lfd);
@@ -380,9 +381,10 @@ static int fill_fd_params(pid_t pid, int fd, int lfd, struct fd_parms *p)
 	p->flags	= fcntl(lfd, F_GETFL);
 	p->pid		= pid;
 	p->id		= FD_ID_INVALID;
+	p->fd_flags	= fd_flags;
 
-	pr_info("%d fdinfo %d: pos: %16lx flags: %16o\n",
-		pid, fd, p->pos, p->flags);
+	pr_info("%d fdinfo %d: pos: %16lx flags: %16o/%x\n",
+		pid, fd, p->pos, p->flags, (int)fd_flags);
 
 	return 0;
 }
@@ -411,12 +413,12 @@ static int dump_chrdev(struct fd_parms *p, int lfd, const struct cr_fdset *set)
 	return dump_unsupp_fd(p);
 }
 
-static int dump_one_file(pid_t pid, int fd, int lfd,
+static int dump_one_file(pid_t pid, int fd, int lfd, char fd_flags,
 		       const struct cr_fdset *cr_fdset)
 {
 	struct fd_parms p;
 
-	if (fill_fd_params(pid, fd, lfd, &p) < 0) {
+	if (fill_fd_params(pid, fd, lfd, fd_flags, &p) < 0) {
 		pr_perror("Can't get stat on %d", fd);
 		return -1;
 	}
@@ -439,6 +441,7 @@ static int dump_task_files_seized(struct parasite_ctl *ctl, const struct cr_fdse
 				  int *fds, int nr_fds)
 {
 	int *lfds;
+	char *flags;
 	int i, ret = -1;
 
 	pr_info("\n");
@@ -449,20 +452,27 @@ static int dump_task_files_seized(struct parasite_ctl *ctl, const struct cr_fdse
 	if (!lfds)
 		goto err;
 
-	ret = parasite_drain_fds_seized(ctl, fds, lfds, nr_fds);
+	flags = xmalloc(PARASITE_MAX_FDS * sizeof(char));
+	if (!flags)
+		goto err1;
+
+	ret = parasite_drain_fds_seized(ctl, fds, lfds, nr_fds, flags);
 	if (ret)
-		goto err;
+		goto err2;
 
 	for (i = 0; i < nr_fds; i++) {
-		ret = dump_one_file(ctl->pid, fds[i], lfds[i], cr_fdset);
+		ret = dump_one_file(ctl->pid, fds[i], lfds[i], flags[i], cr_fdset);
 		close(lfds[i]);
 		if (ret)
-			goto err;
+			goto err2;
 	}
 
 	pr_info("----------------------------------------\n");
-err:
+err2:
+	xfree(flags);
+err1:
 	xfree(lfds);
+err:
 	return ret;
 }
 

cr-show.c

@@ -83,8 +83,8 @@ void show_files(int fd_files, struct cr_options *o)
 		if (ret <= 0)
 			goto out;
 
-		pr_msg("type: %5s fd: %5d id: %8x",
-		       fdtype2s(e.type), e.fd, e.id);
+		pr_msg("type: %5s fd: %5d id: %8x flags %x",
+		       fdtype2s(e.type), e.fd, e.id, e.flags);
 
 		pr_msg("\n");
 	}

files.c

@@ -172,6 +172,7 @@ static int collect_fd(int pid, struct fdinfo_entry *e)
 
 	le->pid = pid;
 	le->fd = e->fd;
+	le->flags = e->flags;
 	futex_init(&le->real_pid);
 
 	fdesc = find_file_desc(e);
@@ -344,6 +345,8 @@ static int open_fd(int pid, struct fdinfo_entry *fe,
 	if (reopen_fd_as(fe->fd, tmp))
 		return -1;
 
+	fcntl(tmp, F_SETFD, fe->flags);
+
 	sock = socket(PF_UNIX, SOCK_DGRAM, 0);
 	if (sock < 0) {
 		pr_perror("Can't create socket");
@@ -369,6 +372,8 @@ static int open_fd(int pid, struct fdinfo_entry *fe,
 				return -1;
 			}
 
+			fcntl(fle->fd, F_SETFD, fle->flags);
+
 			continue;
 		}
 
@@ -402,7 +407,11 @@ static int receive_fd(int pid, struct fdinfo_entry *fe, struct file_desc *d)
 	}
 	close(fe->fd);
 
-	return reopen_fd_as(fe->fd, tmp);
+	if (reopen_fd_as(fe->fd, tmp) < 0)
+		return -1;
+
+	fcntl(tmp, F_SETFD, fe->flags);
+	return 0;
 }
 
 static int open_fdinfo(int pid, struct fdinfo_entry *fe, int *fdinfo_fd, int state)

include/files.h

@@ -12,6 +12,7 @@ struct fd_parms {
 	unsigned long	pos;
 	unsigned int	flags;
 	unsigned int	type;
+	char		fd_flags;
 	struct stat	stat;
 	u32		id;
 	pid_t		pid;
@@ -29,6 +30,7 @@ struct fdinfo_list_entry {
 	struct list_head	list;
 	int			fd;
 	int			pid;
+	int			flags;
 	futex_t			real_pid;
 };
 

include/image.h

@@ -58,6 +58,7 @@ struct reg_file_entry {
 struct fdinfo_entry {
 	u32	fd;
 	u8	type;
+	u8	flags;
 	u32	id;
 } __packed;
 

include/parasite-syscall.h

@@ -41,7 +41,7 @@ struct parasite_dump_tid_addr;
 extern int parasite_dump_tid_addr_seized(struct parasite_ctl *ctl,
 					 pid_t pid, unsigned int **tid_add);
 
-extern int parasite_drain_fds_seized(struct parasite_ctl *ctl, int *fds, int *lfds, int nr_fds);
+extern int parasite_drain_fds_seized(struct parasite_ctl *ctl, int *fds, int *lfds, int nr_fds, char *flags);
 
 extern int parasite_cure_seized(struct parasite_ctl *ctl);
 extern struct parasite_ctl *parasite_infect_seized(pid_t pid,

parasite-syscall.c

@@ -547,7 +547,7 @@ out:
 	return ret;
 }
 
-int parasite_drain_fds_seized(struct parasite_ctl *ctl, int *fds, int *lfds, int nr_fds)
+int parasite_drain_fds_seized(struct parasite_ctl *ctl, int *fds, int *lfds, int nr_fds, char *flags)
 {
 	struct parasite_drain_fd *args;
 	parasite_status_t *st;
@@ -583,7 +583,7 @@ int parasite_drain_fds_seized(struct parasite_ctl *ctl, int *fds, int *lfds, int
 		goto err;
 	}
 
-	ret = recv_fds(sock, lfds, nr_fds, NULL);
+	ret = recv_fds(sock, lfds, nr_fds, flags);
 	if (ret) {
 		pr_err("Can't retrieve FDs from socket\n");
 		goto err;

parasite.c

@@ -373,7 +373,7 @@ static int drain_fds(struct parasite_drain_fd *args)
 	int ret;
 
 	ret = send_fds(tsock, &args->saddr, args->sun_len,
-		       args->fds, args->nr_fds, false);
+		       args->fds, args->nr_fds, true);
 	if (ret) {
 		sys_write_msg("send_fds failed\n");
 		SET_PARASITE_RET(st, ret);

sockets.c

@@ -307,6 +307,7 @@ static int dump_one_inet(struct socket_desc *_sk, struct fd_parms *p,
 	fe.fd = p->fd;
 	fe.type = FDINFO_INETSK;
 	fe.id = sk->sd.ino;
+	fe.flags = p->fd_flags;
 
 	if (write_img(fdset_fd(cr_fdset, CR_FD_FDINFO), &fe))
 		goto err;
@@ -378,6 +379,7 @@ static int dump_one_unix(const struct socket_desc *_sk, struct fd_parms *p,
 	fe.fd = p->fd;
 	fe.type = FDINFO_UNIXSK;
 	fe.id = sk->sd.ino;
+	fe.flags = p->fd_flags;
 
 	if (write_img(fdset_fd(cr_fdset, CR_FD_FDINFO), &fe))
 		goto err;