[src/trunk]: src/sys/dev/ic Don't refer garbage in stack.

[tsutsui <tsutsui%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/68cdf3a0f8bd
branches:  trunk
changeset: 749850:68cdf3a0f8bd
user:      tsutsui <tsutsui%NetBSD.org@localhost>
date:      Fri Dec 11 11:07:04 2009 +0000

description:
Don't refer garbage in stack.
- An argument of struct timeval *tv passed by todr_gettime(9) is used
  for a return value and it doesn't contain valid data. Don't read it.
- Instead, use getmicrotime(9) to get a "reasonable" (i.e. current) time
  to see expected year value (which is not kept by this device).
- If current time is not valid, assume this is the first todr_gettime(9)
  call from inittodr(9) and use file system time for the "reasonable" year.

Fixes silent hangup after mountroot() on sun2.

XXX: MI todr(9) functions seem to get mangled around year ~22000.

diffstat:

 sys/dev/ic/mm58167.c |  16 +++++++++++++---
 1 files changed, 13 insertions(+), 3 deletions(-)

diffs (44 lines):

diff -r a5fd975f67d7 -r 68cdf3a0f8bd sys/dev/ic/mm58167.c
--- a/sys/dev/ic/mm58167.c      Fri Dec 11 09:04:04 2009 +0000
+++ b/sys/dev/ic/mm58167.c      Fri Dec 11 11:07:04 2009 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: mm58167.c,v 1.11 2008/07/06 13:29:50 tsutsui Exp $     */
+/*     $NetBSD: mm58167.c,v 1.12 2009/12/11 11:07:04 tsutsui Exp $     */
 
 /*
  * Copyright (c) 2001 The NetBSD Foundation, Inc.
@@ -34,7 +34,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: mm58167.c,v 1.11 2008/07/06 13:29:50 tsutsui Exp $");
+__KERNEL_RCSID(0, "$NetBSD: mm58167.c,v 1.12 2009/12/11 11:07:04 tsutsui Exp $");
 
 #include <sys/param.h>
 #include <sys/malloc.h>
@@ -84,6 +84,7 @@
        struct mm58167_softc *sc = handle->cookie;
        struct clock_ymdhms dt_hardware;
        struct clock_ymdhms dt_reasonable;
+       struct timeval now;
        int s;
        uint8_t byte_value;
        int leap_year, had_leap_day;
@@ -117,7 +118,16 @@
        splx(s);
 
        /* Convert the reasonable time into a date: */
-       clock_secs_to_ymdhms(tv->tv_sec, &dt_reasonable);
+       getmicrotime(&now);
+       clock_secs_to_ymdhms(now.tv_sec, &dt_reasonable);
+       if (dt_reasonable.dt_year == POSIX_BASE_YEAR) {
+               /*
+                * Not a reasonable year.
+                * Assume called from inittodr(9) on boot and
+                * use file system time set in inittodr(9).
+                */
+               clock_secs_to_ymdhms(handle->base_time, &dt_reasonable);
+       }
 
        /*
         * We need to fake a hardware year.  if the hardware MM/DD