The following commit has been merged in the linux branch: commit 978d7eb31d44de34a7f71e04ed4158f3f854688d Author: Benjamin Herrenschmidt benh@kernel.crashing.org Date: Sun Nov 1 19:11:03 2009 +0000
powerpc: Avoid giving out RTC dates below EPOCH
Doing so causes xtime to be negative which crashes the timekeeping code in funny ways when doing suspend/resume
Signed-off-by: Benjamin Herrenschmidt benh@kernel.crashing.org
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c index 92dc844..a136a11 100644 --- a/arch/powerpc/kernel/time.c +++ b/arch/powerpc/kernel/time.c @@ -777,7 +777,7 @@ int update_persistent_clock(struct timespec now) return ppc_md.set_rtc_time(&tm); }
-void read_persistent_clock(struct timespec *ts) +static void __read_persistent_clock(struct timespec *ts) { struct rtc_time tm; static int first = 1; @@ -800,10 +800,23 @@ void read_persistent_clock(struct timespec *ts) return; } ppc_md.get_rtc_time(&tm); + ts->tv_sec = mktime(tm.tm_year+1900, tm.tm_mon+1, tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec); }
+void read_persistent_clock(struct timespec *ts) +{ + __read_persistent_clock(ts); + + /* Sanitize it in case real time clock is set below EPOCH */ + if (ts->tv_sec < 0) { + ts->tv_sec = 0; + ts->tv_nsec = 0; + } + +} + /* clocksource code */ static cycle_t rtc_read(struct clocksource *cs) {