From ee85d3967ea09b215fcea5efdd90bbbf5e74a681 Mon Sep 17 00:00:00 2001 From: Karel Zak Date: Wed, 19 Feb 2020 15:50:47 +0100 Subject: [PATCH] hwclock: fix for glibc 2.31 settimeofday() glibc announce: ... settimeofday can no longer be used to set the time and the offset simultaneously. If both of its two arguments are non-null, the call will fail (setting errno to EINVAL). It means we need to call settimeofday(NULL, tz) and settimeofday(tv, NULL). Unfortunately, settimeofday(NULL, tz) has very special warp-clock semantic if used as the very first settimeofday() call. It means we have to be sure that we do not touch warp-clock if we need only need to modify system TZ. So, let's always call settimeofday(NULL, 0) before settimeofday(NULL, tz) for UTC rtc mode when modify system TZ. Upstream-Status: Backport [https://github.com/karelzak/util-linux/commit/ee85d3967ea09b215fcea5efdd90bbbf5e74a681] CC: J William Piggott Signed-off-by: Karel Zak Addresses: https://github.com/karelzak/util-linux/issues/957 Signed-off-by: Liwei Song --- sys-utils/hwclock.c | 49 ++++++++++++++++++++++++++------------------- 1 file changed, 28 insertions(+), 21 deletions(-) diff --git a/sys-utils/hwclock.c b/sys-utils/hwclock.c index e736da7179f8..16576bc186ff 100644 --- a/sys-utils/hwclock.c +++ b/sys-utils/hwclock.c @@ -658,6 +658,9 @@ display_time(struct timeval hwctime) * PCIL: persistent_clock_is_local, sets the "11 minute mode" timescale. * firsttime: locks the warp_clock function (initialized to 1 at boot). * + * Note that very first settimeofday(NULL, tz) modifies warp-clock as well as + * system TZ. + * * +---------------------------------------------------------------------------+ * | op | RTC scale | settimeofday calls | * |---------|-----------|-----------------------------------------------------| @@ -675,41 +678,45 @@ set_system_clock(const struct hwclock_control *ctl, struct tm broken; int minuteswest; int rc = 0; - const struct timezone tz_utc = { 0 }; localtime_r(&newtime.tv_sec, &broken); minuteswest = -get_gmtoff(&broken) / 60; if (ctl->verbose) { - if (ctl->hctosys && !ctl->universal) - printf(_("Calling settimeofday(NULL, %d) to set " - "persistent_clock_is_local.\n"), minuteswest); - if (ctl->systz && ctl->universal) + if (ctl->universal) puts(_("Calling settimeofday(NULL, 0) " - "to lock the warp function.")); + "to lock the warp function.")); + else + printf(_("Calling settimeofday(NULL, %d) to set " + "persistent_clock_is_local and " + "the kernel timezone.\n"), minuteswest); + + if (ctl->universal && minuteswest) + printf(_("Calling settimeofday(NULL, %d) to set " + "the kernel timezone.\n"), minuteswest); + if (ctl->hctosys) - printf(_("Calling settimeofday(%ld.%06ld, %d)\n"), - newtime.tv_sec, newtime.tv_usec, minuteswest); - else { - printf(_("Calling settimeofday(NULL, %d) "), minuteswest); - if (ctl->universal) - puts(_("to set the kernel timezone.")); - else - puts(_("to warp System time.")); - } + printf(_("Calling settimeofday(%ld.%06ld, 0) to set " + "the kernel time.\n"), newtime.tv_sec, newtime.tv_usec); } if (!ctl->testing) { + const struct timezone tz_utc = { 0 }; const struct timezone tz = { minuteswest }; - if (ctl->hctosys && !ctl->universal) /* set PCIL */ + /* warp-clock */ + if (ctl->universal) + rc = settimeofday(NULL, &tz_utc); /* lock to UTC */ + else + rc = settimeofday(NULL, &tz); /* set PCIL and TZ */ + + /* set timezone */ + if (!rc && ctl->universal && minuteswest) rc = settimeofday(NULL, &tz); - if (ctl->systz && ctl->universal) /* lock warp_clock */ - rc = settimeofday(NULL, &tz_utc); + + /* set time */ if (!rc && ctl->hctosys) - rc = settimeofday(&newtime, &tz); - else if (!rc) - rc = settimeofday(NULL, &tz); + rc = settimeofday(&newtime, NULL); if (rc) { warn(_("settimeofday() failed")); -- 2.17.1