The branch main has been updated by glebius: URL: https://cgit.FreeBSD.org/src/commit/?id=bc7605647c7193af7eba4b4af65dc7b66a118a09
commit bc7605647c7193af7eba4b4af65dc7b66a118a09 Author: Gleb Smirnoff <[email protected]> AuthorDate: 2022-07-04 19:40:51 +0000 Commit: Gleb Smirnoff <[email protected]> CommitDate: 2022-07-04 19:40:51 +0000 sockets: use positive flag for file descriptor socket reference Rename SS_NOFDREF to SS_FDREF and flip all bitwise operations. Mark sockets created by socreate() with SS_FDREF. This change is mostly illustrative. With it we see that SS_FDREF is a debugging flag, since: * socreate() takes a reference with soref(). * on accept path solisten_dequeue() takes a reference with soref() and then soaccept() sets SS_FDREF. * soclose() checks SS_FDREF, removes it and does sorele(). Reviewed by: tuexen Differential revision: https://reviews.freebsd.org/D35678 --- sys/kern/uipc_debug.c | 4 ++-- sys/kern/uipc_socket.c | 31 +++++++++++++++++-------------- sys/sys/socketvar.h | 2 +- 3 files changed, 20 insertions(+), 17 deletions(-) diff --git a/sys/kern/uipc_debug.c b/sys/kern/uipc_debug.c index cbc26489d8fa..dee2b12e7cb7 100644 --- a/sys/kern/uipc_debug.c +++ b/sys/kern/uipc_debug.c @@ -158,8 +158,8 @@ db_print_sostate(short so_state) int comma; comma = 0; - if (so_state & SS_NOFDREF) { - db_printf("%sSS_NOFDREF", comma ? ", " : ""); + if (so_state & SS_FDREF) { + db_printf("%sSS_FDREF", comma ? ", " : ""); comma = 1; } if (so_state & SS_ISCONNECTED) { diff --git a/sys/kern/uipc_socket.c b/sys/kern/uipc_socket.c index 5063ae5a56e0..aa0470a51a5f 100644 --- a/sys/kern/uipc_socket.c +++ b/sys/kern/uipc_socket.c @@ -498,8 +498,8 @@ sodealloc(struct socket *so) } /* - * socreate returns a socket with a ref count of 1. The socket should be - * closed with soclose(). + * socreate returns a socket with a ref count of 1 and a file descriptor + * reference. The socket should be closed with soclose(). */ int socreate(int dom, struct socket **aso, int type, int proto, @@ -540,6 +540,7 @@ socreate(int dom, struct socket **aso, int type, int proto, return (ENOBUFS); so->so_type = type; + so->so_state = SS_FDREF; so->so_cred = crhold(cred); if ((prp->pr_domain->dom_family == PF_INET) || (prp->pr_domain->dom_family == PF_INET6) || @@ -740,7 +741,7 @@ sonewconn(struct socket *head, int connstatus) so->so_type = head->so_type; so->so_options = head->so_options & ~SO_ACCEPTCONN; so->so_linger = head->so_linger; - so->so_state = head->so_state | SS_NOFDREF; + so->so_state = head->so_state & ~SS_FDREF; so->so_fibnum = head->so_fibnum; so->so_proto = head->so_proto; so->so_cred = crhold(head->so_cred); @@ -1126,7 +1127,7 @@ solisten_dequeue(struct socket *head, struct socket **ret, int flags) * - There are no outstanding file descriptor references or related consumers * (so_count == 0). * - * - The socket has been closed by user space, if ever open (SS_NOFDREF). + * - The socket has been closed by user space, if ever open (no SS_FDREF). * * - The protocol does not have an outstanding strong reference on the socket * (SS_PROTOREF). @@ -1143,7 +1144,7 @@ sofree(struct socket *so) SOCK_LOCK_ASSERT(so); - if ((so->so_state & (SS_NOFDREF | SS_PROTOREF)) != SS_NOFDREF || + if ((so->so_state & (SS_FDREF | SS_PROTOREF)) != 0 || refcount_load(&so->so_count) != 0 || so->so_qstate == SQ_COMP) { SOCK_UNLOCK(so); return; @@ -1159,7 +1160,7 @@ sofree(struct socket *so) * To solve race between close of a listening socket and * a socket on its incomplete queue, we need to lock both. * The order is first listening socket, then regular. - * Since we don't have SS_NOFDREF neither SS_PROTOREF, this + * Since we don't have SS_FDREF neither SS_PROTOREF, this * function and the listening socket are the only pointers * to so. To preserve so and sol, we reference both and then * relock. @@ -1254,7 +1255,8 @@ soclose(struct socket *so) int error = 0; bool listening, last __diagused; - KASSERT(!(so->so_state & SS_NOFDREF), ("soclose: SS_NOFDREF on enter")); + KASSERT(so->so_state & SS_FDREF, + ("%s: %p no SS_FDREF on enter", __func__, so)); CURVNET_SET(so->so_vnet); funsetown(&so->so_sigio); @@ -1306,8 +1308,9 @@ drop: __func__, so)); } } - KASSERT((so->so_state & SS_NOFDREF) == 0, ("soclose: NOFDREF")); - so->so_state |= SS_NOFDREF; + KASSERT(so->so_state & SS_FDREF, + ("%s: %p no SS_FDREF upon lock", __func__, so)); + so->so_state &= ~SS_FDREF; sorele_locked(so); if (listening) { struct socket *sp, *tsp; @@ -1352,9 +1355,8 @@ soabort(struct socket *so) * current thread is responsible for arranging for no references, but * is as close as we can get for now. */ - KASSERT(so->so_count == 0, ("soabort: so_count")); - KASSERT((so->so_state & SS_PROTOREF) == 0, ("soabort: SS_PROTOREF")); - KASSERT(so->so_state & SS_NOFDREF, ("soabort: !SS_NOFDREF")); + KASSERT((so->so_state & (SS_FDREF | SS_PROTOREF)) == 0 && + so->so_count == 0, ("%s: so %p has references", __func__, so)); VNET_SO_ASSERT(so); if (so->so_proto->pr_usrreqs->pru_abort != NULL) @@ -1369,8 +1371,9 @@ soaccept(struct socket *so, struct sockaddr **nam) int error; SOCK_LOCK(so); - KASSERT((so->so_state & SS_NOFDREF) != 0, ("soaccept: !NOFDREF")); - so->so_state &= ~SS_NOFDREF; + KASSERT((so->so_state & SS_FDREF) == 0, + ("%s: %p has SS_FDREF", __func__, so)); + so->so_state |= SS_FDREF; SOCK_UNLOCK(so); CURVNET_SET(so->so_vnet); diff --git a/sys/sys/socketvar.h b/sys/sys/socketvar.h index 85aa7cbfea0f..d1ce687ac956 100644 --- a/sys/sys/socketvar.h +++ b/sys/sys/socketvar.h @@ -210,7 +210,7 @@ struct socket { * Many fields will be read without locks to improve performance and avoid * lock order issues. However, this approach must be used with caution. */ -#define SS_NOFDREF 0x0001 /* no file table ref any more */ +#define SS_FDREF 0x0001 /* strong file descriptor reference */ #define SS_ISCONNECTED 0x0002 /* socket connected to a peer */ #define SS_ISCONNECTING 0x0004 /* in process of connecting to peer */ #define SS_ISDISCONNECTING 0x0008 /* in process of disconnecting */
