d/freebsd-skq
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Fix a degenerate case when soisdisconnected() would call soisconnected().

Browse Source 
This happens when closing a socket with upcall, and trace is: soclose()->
... protocol ... -> soisdisconnected() -> socantrcvmore_locked() ->
sowakeup() -> soisconnected().

Right now this case is innocent for two reasons.  First, soisconnected()
doesn't clear SS_ISDISCONNECTED flag.  Second, the mutex to lock the
socket is the socket receive buffer mutex, and sodisconnected() first
disables the receive buffer. But in future code, the mutex to lock
socket is different to buffer mutex, and we would get undesired mutex
recursion.

The fix is to check SS_ISDISCONNECTED flag before calling upcall.
This commit is contained in:
glebius 2017-06-08 06:16:47 +00:00
parent fc98df1a87
commit cc7cb64916
1 changed files with 1 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
sys/kern/uipc_sockbuf.c
View File

@ -322,7 +322,7 @@ sowakeup(struct socket *so, struct sockbuf *sb)
wakeup(&sb->sb_acc);
}
KNOTE_LOCKED(&sb->sb_sel.si_note, 0);
if (sb->sb_upcall != NULL) {
if (sb->sb_upcall != NULL && !(so->so_state & SS_ISDISCONNECTED)) {
ret = sb->sb_upcall(so, sb->sb_upcallarg, M_NOWAIT);
if (ret == SU_ISCONNECTED) {
KASSERT(sb == &so->so_rcv,