lib/pty: make sure we not use closed FD

Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/lib/pty-session.c b/lib/pty-session.c
index a7fb7d40b5cf52c82462a7eb818a6e97cdd451ca..87d8e58b5eafd8ffd177bc2165bf5972970c4f09 100644 (file)
--- a/lib/pty-session.c
+++ b/lib/pty-session.c
@@ -312,11 +312,16 @@ static void write_eof_to_child(struct ul_pty *pty)
 
 static int mainloop_callback(struct ul_pty *pty)
 {
+       int rc;
+
        if (!pty->callbacks.mainloop)
                return 0;
 
        DBG(IO, ul_debugobj(pty, "calling mainloop callback"));
-       return pty->callbacks.mainloop(pty->callback_data);
+       rc = pty->callbacks.mainloop(pty->callback_data);
+
+       DBG(IO, ul_debugobj(pty, " callback done [rc=%d]", rc));
+       return rc;
 }
 
 static int handle_io(struct ul_pty *pty, int fd, int *eof)
@@ -565,14 +570,16 @@ int ul_pty_proxy_master(struct ul_pty *pty)
                        if (pfd[i].revents == 0)
                                continue;
 
-                       DBG(IO, ul_debugobj(pty, " active pfd[%s].fd=%d %s %s %s",
+                       DBG(IO, ul_debugobj(pty, " active pfd[%s].fd=%d %s %s %s %s",
                                                i == POLLFD_STDIN  ? "stdin" :
                                                i == POLLFD_MASTER ? "master" :
                                                i == POLLFD_SIGNAL ? "signal" : "???",
                                                pfd[i].fd,
                                                pfd[i].revents & POLLIN  ? "POLLIN" : "",
                                                pfd[i].revents & POLLHUP ? "POLLHUP" : "",
-                                               pfd[i].revents & POLLERR ? "POLLERR" : ""));
+                                               pfd[i].revents & POLLERR ? "POLLERR" : "",
+                                               pfd[i].revents & POLLNVAL ? "POLLNVAL" : ""));
+
                        switch (i) {
                        case POLLFD_STDIN:
                        case POLLFD_MASTER:
@@ -581,8 +588,11 @@ int ul_pty_proxy_master(struct ul_pty *pty)
                                        rc = handle_io(pty, pfd[i].fd, &eof);
                                /* EOF maybe detected by two ways:
                                 *      A) poll() return POLLHUP event after close()
-                                *      B) read() returns 0 (no data) */
-                               if ((pfd[i].revents & POLLHUP) || eof) {
+                                *      B) read() returns 0 (no data)
+                                *
+                                * POLLNVAL means that fd is closed.
+                                */
+                               if ((pfd[i].revents & POLLHUP) || (pfd[i].revents & POLLNVAL) || eof) {
                                        DBG(IO, ul_debugobj(pty, " ignore FD"));
                                        pfd[i].fd = -1;
                                        if (i == POLLFD_STDIN) {