On 11/12/17(Mon) 08:55, Martin Pieuchot wrote:
> Diff below shuffle the socket buffer definition to "properly" memset()
> all required fields in sorflush(). It also gets rid of the sbrelease()
> abstraction since zeroing out `sb_hiwat' and `sb_mbmax' is required in
> only one place.
Simpler diff that just do the zeroing, anyone?
Index: kern/uipc_socket.c
===================================================================
RCS file: /cvs/src/sys/kern/uipc_socket.c,v
retrieving revision 1.212
diff -u -p -r1.212 uipc_socket.c
--- kern/uipc_socket.c 19 Dec 2017 09:29:37 -0000 1.212
+++ kern/uipc_socket.c 27 Dec 2017 15:08:58 -0000
@@ -1052,12 +1052,8 @@ sorflush(struct socket *so)
sbunlock(so, sb);
aso.so_proto = pr;
aso.so_rcv = *sb;
- memset(sb, 0, sizeof (*sb));
- /* XXX - the memset stomps all over so_rcv */
- if (aso.so_rcv.sb_flagsintr & SB_KNOTE) {
- sb->sb_sel.si_note = aso.so_rcv.sb_sel.si_note;
- sb->sb_flagsintr = SB_KNOTE;
- }
+ memset(&sb->sb_startzero, 0,
+ (caddr_t)&sb->sb_endzero - (caddr_t)&sb->sb_startzero);
if (pr->pr_flags & PR_RIGHTS && pr->pr_domain->dom_dispose)
(*pr->pr_domain->dom_dispose)(aso.so_rcv.sb_mb);
sbrelease(&aso, &aso.so_rcv);
Index: sys/socketvar.h
===================================================================
RCS file: /cvs/src/sys/sys/socketvar.h,v
retrieving revision 1.80
diff -u -p -r1.80 socketvar.h
--- sys/socketvar.h 18 Dec 2017 10:07:55 -0000 1.80
+++ sys/socketvar.h 27 Dec 2017 15:07:10 -0000
@@ -98,6 +98,8 @@ struct socket {
* Variables for socket buffering.
*/
struct sockbuf {
+/* The following fields are all zeroed on flush. */
+#define sb_startzero sb_cc
u_long sb_cc; /* actual chars in buffer */
u_long sb_datacc; /* data only chars in buffer */
u_long sb_hiwat; /* max actual char count */
@@ -109,10 +111,12 @@ struct socket {
struct mbuf *sb_mbtail; /* the last mbuf in the chain */
struct mbuf *sb_lastrecord;/* first mbuf of last record in
socket buffer */
- struct selinfo sb_sel; /* process selecting read/write */
- int sb_flagsintr; /* flags, changed during interrupt */
- short sb_flags; /* flags, see below */
u_short sb_timeo; /* timeout for read/write */
+ short sb_flags; /* flags, see below */
+/* End area that is zeroed on flush. */
+#define sb_endzero sb_flags
+ int sb_flagsintr; /* flags, changed atomically */
+ struct selinfo sb_sel; /* process selecting read/write */
} so_rcv, so_snd;
#define SB_MAX (2*1024*1024) /* default for max chars in
sockbuf */
#define SB_LOCK 0x01 /* lock on data queue */
