Module Name: src
Committed By: riastradh
Date: Mon Jul 17 13:35:07 UTC 2023
Modified Files:
src/sys/kern: kern_tc.c
Log Message:
timecounter(9): Ward off interrupts during time_second/uptime update.
Only relevant during 32-bit wraparound, so the potential performance
impact of using splhigh here is negligible; indeed, we would have to
go out of our way to exercise this in tests before it will ever
happen in the next century.
To generate a diff of this commit:
cvs rdiff -u -r1.64 -r1.65 src/sys/kern/kern_tc.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/kern_tc.c
diff -u src/sys/kern/kern_tc.c:1.64 src/sys/kern/kern_tc.c:1.65
--- src/sys/kern/kern_tc.c:1.64 Mon Jul 17 13:29:12 2023
+++ src/sys/kern/kern_tc.c Mon Jul 17 13:35:07 2023
@@ -1,4 +1,4 @@
-/* $NetBSD: kern_tc.c,v 1.64 2023/07/17 13:29:12 riastradh Exp $ */
+/* $NetBSD: kern_tc.c,v 1.65 2023/07/17 13:35:07 riastradh Exp $ */
/*-
* Copyright (c) 2008, 2009 The NetBSD Foundation, Inc.
@@ -40,7 +40,7 @@
#include <sys/cdefs.h>
/* __FBSDID("$FreeBSD: src/sys/kern/kern_tc.c,v 1.166 2005/09/19 22:16:31 andre Exp $"); */
-__KERNEL_RCSID(0, "$NetBSD: kern_tc.c,v 1.64 2023/07/17 13:29:12 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_tc.c,v 1.65 2023/07/17 13:35:07 riastradh Exp $");
#ifdef _KERNEL_OPT
#include "opt_ntp.h"
@@ -172,6 +172,7 @@ setrealuptime(time_t second, time_t upti
{
uint32_t seclo = second & 0xffffffff, sechi = second >> 32;
uint32_t uplo = uptime & 0xffffffff, uphi = uptime >> 32;
+ int s;
KDASSERT(mutex_owned(&timecounter_lock));
@@ -186,6 +187,7 @@ setrealuptime(time_t second, time_t upti
return;
}
+ s = splhigh();
atomic_store_relaxed(&time__second32.hi, 0xffffffff);
atomic_store_relaxed(&time__uptime32.hi, 0xffffffff);
membar_producer();
@@ -194,6 +196,7 @@ setrealuptime(time_t second, time_t upti
membar_producer();
atomic_store_relaxed(&time__second32.hi, sechi);
atomic_store_relaxed(&time__uptime32.hi, uphi);
+ splx(s);
}
time_t
