Module Name: src
Committed By: riastradh
Date: Sat Apr 9 23:52:05 UTC 2022
Modified Files:
src/sys/kern: sys_select.c
Log Message:
select(9): Use membar_acquire/release and atomic_store_release.
No store-before-load ordering here -- this was obviously always
intended to be load-before-load/store all along.
To generate a diff of this commit:
cvs rdiff -u -r1.58 -r1.59 src/sys/kern/sys_select.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/kern/sys_select.c
diff -u src/sys/kern/sys_select.c:1.58 src/sys/kern/sys_select.c:1.59
--- src/sys/kern/sys_select.c:1.58 Sat Feb 12 15:51:29 2022
+++ src/sys/kern/sys_select.c Sat Apr 9 23:52:05 2022
@@ -1,4 +1,4 @@
-/* $NetBSD: sys_select.c,v 1.58 2022/02/12 15:51:29 thorpej Exp $ */
+/* $NetBSD: sys_select.c,v 1.59 2022/04/09 23:52:05 riastradh Exp $ */
/*-
* Copyright (c) 2007, 2008, 2009, 2010, 2019, 2020 The NetBSD Foundation, Inc.
@@ -84,7 +84,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: sys_select.c,v 1.58 2022/02/12 15:51:29 thorpej Exp $");
+__KERNEL_RCSID(0, "$NetBSD: sys_select.c,v 1.59 2022/04/09 23:52:05 riastradh Exp $");
#include <sys/param.h>
#include <sys/systm.h>
@@ -282,7 +282,7 @@ sel_do_scan(const char *opname, void *fd
l->l_selflag = SEL_SCANNING;
}
ncoll = sc->sc_ncoll;
- membar_exit();
+ membar_release();
if (opname == selop_select) {
error = selscan((char *)fds, nf, ni, retval);
@@ -653,7 +653,7 @@ selrecord(lwp_t *selector, struct selinf
* barrier to ensure that we access sel_lwp (above) before
* other fields - this guards against a call to selclear().
*/
- membar_enter();
+ membar_acquire();
sip->sel_lwp = selector;
SLIST_INSERT_HEAD(&selector->l_selwait, sip, sel_chain);
/* Copy the argument, which is for selnotify(). */
@@ -872,9 +872,8 @@ selclear(void)
* globally visible.
*/
next = SLIST_NEXT(sip, sel_chain);
- membar_exit();
/* Release the record for another named waiter to use. */
- sip->sel_lwp = NULL;
+ atomic_store_release(&sip->sel_lwp, NULL);
}
mutex_spin_exit(lock);
}
