From fbd28b3b40701f1fda29707dfa09d1e481c4162c Mon Sep 17 00:00:00 2001
From: hexiaowen<hexiaowen@huawei.com>
Date: Tue, 9 Jul 2019 19:13:43 +0800
Subject: [PATCH] delete clock_apply_epoch

resolved: apply epoch to system time from PID 1

For use in timesyncd we already defined a compile-time "epoch" value, which is based on the mtime of the NEWS file, and
specifies a point in time we know lies in the past at runtime. timesyncd uses this to filter out nonsensical timestamp
file data, and bump the system clock to a time that is after the build time of systemd. This patch adds similar bumping
code to earliest PID 1 initialization, so that the system never continues operation with a clock that is in the 1970ies
or even 1930s. we think it is ok when current system time is before build time.

And, don't restore time when systemd-timesyncd started.

---
 src/core/main.c          | 12 ------------
 src/timesync/timesyncd.c |  8 --------
 2 files changed, 20 deletions(-)

diff --git a/src/core/main.c b/src/core/main.c
index 4051a91..c6d16b2 100644
--- a/src/core/main.c
+++ b/src/core/main.c
@@ -1627,18 +1627,6 @@ static void initialize_clock(void) {
                  */
                 (void) clock_reset_timewarp();
 
-        ClockChangeDirection change_dir;
-        r = clock_apply_epoch(&change_dir);
-        if (r > 0 && change_dir == CLOCK_CHANGE_FORWARD)
-                log_info("System time before build time, advancing clock.");
-        else if (r > 0 && change_dir == CLOCK_CHANGE_BACKWARD)
-                log_info("System time is further ahead than %s after build time, resetting clock to build time.",
-                         FORMAT_TIMESPAN(CLOCK_VALID_RANGE_USEC_MAX, USEC_PER_DAY));
-        else if (r < 0 && change_dir == CLOCK_CHANGE_FORWARD)
-                log_error_errno(r, "Current system time is before build time, but cannot correct: %m");
-        else if (r < 0 && change_dir == CLOCK_CHANGE_BACKWARD)
-                log_error_errno(r, "Current system time is further ahead %s after build time, but cannot correct: %m",
-                                FORMAT_TIMESPAN(CLOCK_VALID_RANGE_USEC_MAX, USEC_PER_DAY));
 }
 
 static void apply_clock_update(void) {
diff --git a/src/timesync/timesyncd.c b/src/timesync/timesyncd.c
index e60742c..efe56fd 100644
--- a/src/timesync/timesyncd.c
+++ b/src/timesync/timesyncd.c
@@ -121,14 +121,6 @@ static int load_clock_timestamp(uid_t uid, gid_t gid) {
         if (ct > min)
                 return 0;
 
-        /* Not that it matters much, but we actually restore the clock to n+1 here rather than n, simply
-         * because we read n as time previously already and we want to progress here, i.e. not report the
-         * same time again. */
-        if (clock_settime(CLOCK_REALTIME, TIMESPEC_STORE(min+1)) < 0) {
-                log_warning_errno(errno, "Failed to restore system clock, ignoring: %m");
-                return 0;
-        }
-
         log_struct(LOG_INFO,
                    "MESSAGE_ID=" SD_MESSAGE_TIME_BUMP_STR,
                    "REALTIME_USEC=" USEC_FMT, min+1,
-- 
2.33.0