char-socket: initialize reconnect timer only when the timer doesn't start

When the disconnect event is triggered in the connecting stage,
the tcp_chr_disconnect_locked may be called twice.

The first call:
    #0  qemu_chr_socket_restart_timer (chr=0x55555582ee90) at chardev/char-socket.c:120
    #1  0x000055555558e38c in tcp_chr_disconnect_locked (chr=<optimized out>) at chardev/char-socket.c:490
    #2  0x000055555558e3cd in tcp_chr_disconnect (chr=0x55555582ee90) at chardev/char-socket.c:497
    #3  0x000055555558ea32 in tcp_chr_new_client (chr=chr@entry=0x55555582ee90, sioc=sioc@entry=0x55555582f0b0) at chardev/char-socket.c:892
    #4  0x000055555558eeb8 in qemu_chr_socket_connected (task=0x55555582f300, opaque=<optimized out>) at chardev/char-socket.c:1090
    #5  0x0000555555574352 in qio_task_complete (task=task@entry=0x55555582f300) at io/task.c:196
    #6  0x00005555555745f4 in qio_task_thread_result (opaque=0x55555582f300) at io/task.c:111
    #7  qio_task_wait_thread (task=0x55555582f300) at io/task.c:190
    #8  0x000055555558f17e in tcp_chr_wait_connected (chr=0x55555582ee90, errp=0x555555802a08 <error_abort>) at chardev/char-socket.c:1013
    #9  0x0000555555567cbd in char_socket_client_reconnect_test (opaque=0x5555557fe020 <client8unix>) at tests/test-char.c:1152
The second call:
    #0  0x00007ffff5ac3277 in raise () from /lib64/libc.so.6
    #1  0x00007ffff5ac4968 in abort () from /lib64/libc.so.6
    #2  0x00007ffff5abc096 in __assert_fail_base () from /lib64/libc.so.6
    #3  0x00007ffff5abc142 in __assert_fail () from /lib64/libc.so.6
    #4  0x000055555558d10a in qemu_chr_socket_restart_timer (chr=0x55555582ee90) at chardev/char-socket.c:125
    #5  0x000055555558df0c in tcp_chr_disconnect_locked (chr=<optimized out>) at chardev/char-socket.c:490
    #6  0x000055555558df4d in tcp_chr_disconnect (chr=0x55555582ee90) at chardev/char-socket.c:497
    #7  0x000055555558e5b2 in tcp_chr_new_client (chr=chr@entry=0x55555582ee90, sioc=sioc@entry=0x55555582f0b0) at chardev/char-socket.c:892
    #8  0x000055555558e93a in tcp_chr_connect_client_sync (chr=chr@entry=0x55555582ee90, errp=errp@entry=0x7fffffffd178) at chardev/char-socket.c:944
    #9  0x000055555558ec78 in tcp_chr_wait_connected (chr=0x55555582ee90, errp=0x555555802a08 <error_abort>) at chardev/char-socket.c:1035
    #10 0x000055555556804b in char_socket_client_test (opaque=0x5555557fe020 <client8unix>) at tests/test-char.c:1023

Run test/test-char to reproduce this issue.

test-char: chardev/char-socket.c:125: qemu_chr_socket_restart_timer: Assertion `!s->reconnect_timer' failed.

Signed-off-by: Li Feng <fengli@smartx.com>
Acked-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20200522025554.41063-1-fengli@smartx.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/chardev/char-socket.c b/chardev/char-socket.c
index 5758d9900f..320aa7c642 100644
--- a/chardev/char-socket.c
+++ b/chardev/char-socket.c
@@ -490,7 +490,7 @@ static void tcp_chr_disconnect_locked(Chardev *chr)
     if (emit_close) {
         qemu_chr_be_event(chr, CHR_EVENT_CLOSED);
     }
-    if (s->reconnect_time) {
+    if (s->reconnect_time && !s->reconnect_timer) {
         qemu_chr_socket_restart_timer(chr);
     }
 }