[src/trunk]: src/sys/arch/arm/allwinner Sanity-check the date before storing ...

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

details:   https://anonhg.NetBSD.org/src/rev/3d4855104fca
branches:  trunk
changeset: 333281:3d4855104fca
user:      martin <martin%NetBSD.org@localhost>
date:      Mon Oct 27 08:51:59 2014 +0000

description:
Sanity-check the date before storing it in the RTC, error out for non
representable dates.

diffstat:

 sys/arch/arm/allwinner/awin_rtc.c |  34 +++++++++++++++++++++++++++++-----
 1 files changed, 29 insertions(+), 5 deletions(-)

diffs (64 lines):

diff -r 485831969177 -r 3d4855104fca sys/arch/arm/allwinner/awin_rtc.c
--- a/sys/arch/arm/allwinner/awin_rtc.c Mon Oct 27 07:49:25 2014 +0000
+++ b/sys/arch/arm/allwinner/awin_rtc.c Mon Oct 27 08:51:59 2014 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: awin_rtc.c,v 1.2 2014/10/12 17:20:58 jmcneill Exp $ */
+/* $NetBSD: awin_rtc.c,v 1.3 2014/10/27 08:51:59 martin Exp $ */
 
 /*-
  * Copyright (c) 2014 Jared D. McNeill <jmcneill%invisible.ca@localhost>
@@ -27,7 +27,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: awin_rtc.c,v 1.2 2014/10/12 17:20:58 jmcneill Exp $");
+__KERNEL_RCSID(0, "$NetBSD: awin_rtc.c,v 1.3 2014/10/27 08:51:59 martin Exp $");
 
 #include <sys/param.h>
 #include <sys/bus.h>
@@ -135,18 +135,42 @@
 awin_rtc_settime(todr_chip_handle_t tch, struct clock_ymdhms *dt)
 {
        struct awin_rtc_softc *sc = tch->cookie;
-       uint32_t yymmdd, hhmmss, losc;
+       uint32_t yymmdd, hhmmss, losc, maxyear;
 
        losc = RTC_READ(sc, sc->sc_loscctrl_reg);
        if (losc & AWIN_LOSC_CTRL_BUSY)
                return EBUSY;
 
-       yymmdd = 0;
-       yymmdd |= __SHIFTIN(dt->dt_year - POSIX_BASE_YEAR,
+       /*
+        * Sanity check the date before writing it back
+        */
+       if (dt->dt_year < POSIX_BASE_YEAR) {
+               aprint_normal_dev(sc->sc_dev, "year pre the epoch: %llu, "
+                   "not writing back time\n", dt->dt_year);
+               return EIO;
+       }
+       maxyear = __SHIFTOUT(0xffffffff, 
+           awin_chip_id() == AWIN_CHIP_ID_A31 ?
+           AWIN_A31_RTC_YY_MM_DD_YEAR : AWIN_RTC_YY_MM_DD_YEAR)
+           + POSIX_BASE_YEAR;
+       if (dt->dt_year > maxyear) {
+               aprint_normal_dev(sc->sc_dev, "year exceeds avialable field:"
+                   " %llu, not writing back time\n", dt->dt_year);
+               return EIO;
+       }
+
+       yymmdd = __SHIFTIN(dt->dt_year - POSIX_BASE_YEAR,
            awin_chip_id() == AWIN_CHIP_ID_A31 ?
            AWIN_A31_RTC_YY_MM_DD_YEAR : AWIN_RTC_YY_MM_DD_YEAR);
+
+       KASSERT(__SHIFTOUT(yymmdd,
+           awin_chip_id() == AWIN_CHIP_ID_A31 ?
+           AWIN_A31_RTC_YY_MM_DD_YEAR : AWIN_RTC_YY_MM_DD_YEAR) +
+           POSIX_BASE_YEAR == dt->dt_year);
+
        yymmdd |= __SHIFTIN(dt->dt_mon, AWIN_RTC_YY_MM_DD_MONTH);
        yymmdd |= __SHIFTIN(dt->dt_day, AWIN_RTC_YY_MM_DD_DAY);
+
        hhmmss = 0;
        hhmmss |= __SHIFTIN(dt->dt_wday, AWIN_RTC_HH_MM_SS_WK_NO);
        hhmmss |= __SHIFTIN(dt->dt_hour, AWIN_RTC_HH_MM_SS_HOUR);