Module Name: src
Committed By: thorpej
Date: Mon Sep 27 00:40:49 UTC 2021
Modified Files:
src/sys/kern: sys_eventfd.c sys_timerfd.c tty.c
Log Message:
Consistently reference kn->kn_data only within the lock perimeter in
the filtops f_event() callback.
To generate a diff of this commit:
cvs rdiff -u -r1.6 -r1.7 src/sys/kern/sys_eventfd.c
cvs rdiff -u -r1.5 -r1.6 src/sys/kern/sys_timerfd.c
cvs rdiff -u -r1.296 -r1.297 src/sys/kern/tty.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_eventfd.c
diff -u src/sys/kern/sys_eventfd.c:1.6 src/sys/kern/sys_eventfd.c:1.7
--- src/sys/kern/sys_eventfd.c:1.6 Sun Sep 26 03:42:54 2021
+++ src/sys/kern/sys_eventfd.c Mon Sep 27 00:40:49 2021
@@ -1,4 +1,4 @@
-/* $NetBSD: sys_eventfd.c,v 1.6 2021/09/26 03:42:54 thorpej Exp $ */
+/* $NetBSD: sys_eventfd.c,v 1.7 2021/09/27 00:40:49 thorpej Exp $ */
/*-
* Copyright (c) 2020 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: sys_eventfd.c,v 1.6 2021/09/26 03:42:54 thorpej Exp $");
+__KERNEL_RCSID(0, "$NetBSD: sys_eventfd.c,v 1.7 2021/09/27 00:40:49 thorpej Exp $");
/*
* eventfd
@@ -408,6 +408,7 @@ static int
eventfd_filt_read(struct knote * const kn, long const hint)
{
struct eventfd * const efd = ((file_t *)kn->kn_obj)->f_eventfd;
+ int rv;
if (hint & NOTE_SUBMIT) {
KASSERT(mutex_owned(&efd->efd_lock));
@@ -416,12 +417,13 @@ eventfd_filt_read(struct knote * const k
}
kn->kn_data = (int64_t)efd->efd_val;
+ rv = (eventfd_t)kn->kn_data > 0;
if ((hint & NOTE_SUBMIT) == 0) {
mutex_exit(&efd->efd_lock);
}
- return (eventfd_t)kn->kn_data > 0;
+ return rv;
}
static const struct filterops eventfd_read_filterops = {
@@ -445,6 +447,7 @@ static int
eventfd_filt_write(struct knote * const kn, long const hint)
{
struct eventfd * const efd = ((file_t *)kn->kn_obj)->f_eventfd;
+ int rv;
if (hint & NOTE_SUBMIT) {
KASSERT(mutex_owned(&efd->efd_lock));
@@ -453,12 +456,13 @@ eventfd_filt_write(struct knote * const
}
kn->kn_data = (int64_t)efd->efd_val;
+ rv = (eventfd_t)kn->kn_data < EVENTFD_MAXVAL;
if ((hint & NOTE_SUBMIT) == 0) {
mutex_exit(&efd->efd_lock);
}
- return (eventfd_t)kn->kn_data < EVENTFD_MAXVAL;
+ return rv;
}
static const struct filterops eventfd_write_filterops = {
Index: src/sys/kern/sys_timerfd.c
diff -u src/sys/kern/sys_timerfd.c:1.5 src/sys/kern/sys_timerfd.c:1.6
--- src/sys/kern/sys_timerfd.c:1.5 Sun Sep 26 03:42:54 2021
+++ src/sys/kern/sys_timerfd.c Mon Sep 27 00:40:49 2021
@@ -1,4 +1,4 @@
-/* $NetBSD: sys_timerfd.c,v 1.5 2021/09/26 03:42:54 thorpej Exp $ */
+/* $NetBSD: sys_timerfd.c,v 1.6 2021/09/27 00:40:49 thorpej Exp $ */
/*-
* Copyright (c) 2020 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: sys_timerfd.c,v 1.5 2021/09/26 03:42:54 thorpej Exp $");
+__KERNEL_RCSID(0, "$NetBSD: sys_timerfd.c,v 1.6 2021/09/27 00:40:49 thorpej Exp $");
/*
* timerfd
@@ -404,6 +404,7 @@ static int
timerfd_filt_read(struct knote * const kn, long const hint)
{
struct timerfd * const tfd = ((file_t *)kn->kn_obj)->f_timerfd;
+ int rv;
if (hint & NOTE_SUBMIT) {
KASSERT(itimer_lock_held());
@@ -412,12 +413,13 @@ timerfd_filt_read(struct knote * const k
}
kn->kn_data = (int64_t)timerfd_fire_count(tfd);
+ rv = kn->kn_data != 0;
if ((hint & NOTE_SUBMIT) == 0) {
itimer_unlock();
}
- return kn->kn_data != 0;
+ return rv;
}
static const struct filterops timerfd_read_filterops = {
Index: src/sys/kern/tty.c
diff -u src/sys/kern/tty.c:1.296 src/sys/kern/tty.c:1.297
--- src/sys/kern/tty.c:1.296 Sun Sep 26 01:16:10 2021
+++ src/sys/kern/tty.c Mon Sep 27 00:40:49 2021
@@ -1,4 +1,4 @@
-/* $NetBSD: tty.c,v 1.296 2021/09/26 01:16:10 thorpej Exp $ */
+/* $NetBSD: tty.c,v 1.297 2021/09/27 00:40:49 thorpej Exp $ */
/*-
* Copyright (c) 2008, 2020 The NetBSD Foundation, Inc.
@@ -63,7 +63,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: tty.c,v 1.296 2021/09/26 01:16:10 thorpej Exp $");
+__KERNEL_RCSID(0, "$NetBSD: tty.c,v 1.297 2021/09/27 00:40:49 thorpej Exp $");
#ifdef _KERNEL_OPT
#include "opt_compat_netbsd.h"
@@ -1477,14 +1477,16 @@ static int
filt_ttyread(struct knote *kn, long hint)
{
struct tty *tp;
+ int rv;
tp = kn->kn_hook;
if ((hint & NOTE_SUBMIT) == 0)
mutex_spin_enter(&tty_lock);
kn->kn_data = ttnread(tp);
+ rv = kn->kn_data > 0;
if ((hint & NOTE_SUBMIT) == 0)
mutex_spin_exit(&tty_lock);
- return (kn->kn_data > 0);
+ return rv;
}
static void
