Aren/NetBSD
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fix and cleanup for tvtohz():

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-assume (KASSERT) that the timeval given is normalized, and remove
 some partial fixup which I don't see what it is good for
 (I'm ready to back that out if someone tells a reason)
-catch overflows due to conversion of time_t (from tv_sec) to
 integer -- this function doesn't do 64-bit arithmetics (which makes
 sense because relative times which don't fit into 32 bits can be
 considered nonsense here), and before a huge tv_sec could lead to
 a zero hz result, violating the caller's assumptions (in particular
 trigger a diagnostic panic in abstimeout2timo())
This commit is contained in:
drochner 2011-01-26 19:15:13 +00:00
parent 9e17c3f550
commit cc068f7930
1 changed files with 10 additions and 7 deletions
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17
sys/kern/subr_time.c
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@ -1,4 +1,4 @@
/* $NetBSD: subr_time.c,v 1.7 2010/04/26 16:26:11 rmind Exp $ */
/* $NetBSD: subr_time.c,v 1.8 2011/01/26 19:15:13 drochner Exp $ */
/*
* Copyright (c) 1982, 1986, 1989, 1993
@ -33,7 +33,7 @@
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: subr_time.c,v 1.7 2010/04/26 16:26:11 rmind Exp $");
__KERNEL_RCSID(0, "$NetBSD: subr_time.c,v 1.8 2011/01/26 19:15:13 drochner Exp $");
#include <sys/param.h>
#include <sys/kernel.h>
@ -89,12 +89,15 @@ tvtohz(const struct timeval *tv)
sec = tv->tv_sec;
usec = tv->tv_usec;
if (usec < 0) {
sec--;
usec += 1000000;
}
KASSERT(usec >= 0 && usec < 1000000);
if (sec < 0 || (sec == 0 && usec <= 0)) {
/* catch overflows in conversion time_t->int */
if (tv->tv_sec > INT_MAX)
return INT_MAX;
if (tv->tv_sec < 0)
return 0;
if (sec < 0 || (sec == 0 && usec == 0)) {
/*
* Would expire now or in the past. Return 0 ticks.
* This is different from the legacy tvhzto() interface,