From 19a6baf0b79346deb383bbd2b5b825d59add7d5d Mon Sep 17 00:00:00 2001 From: Sakib Sajal Date: Fri, 17 Jul 2020 17:27:21 +0000 Subject: [PATCH] hwclock: make glibc 2.31 compatible NEWS for glibc version 2.31 =========================== Deprecated and removed features, and other changes affecting compatibility: * The settimeofday function can still be used to set a system-wide time zone when the operating system supports it. This is because the Linux kernel reused the API, on some architectures, to describe a system-wide time-zone-like offset between the software clock maintained by the kernel, and the "RTC" clock that keeps time when the system is shut down. However, to reduce the odds of this offset being set by accident, 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). Callers attempting to set this offset should also be prepared for the call to fail and set errno to ENOSYS; this already happens on the Hurd and on some Linux architectures. The Linux kernel maintainers are discussing a more principled replacement for the reused API. After a replacement becomes available, we will change settimeofday to fail with ENOSYS on all platforms when its 'tzp' argument is not a null pointer. settimeofday itself is obsolescent according to POSIX. Programs that set the system time should use clock_settime and/or the adjtime family of functions instead. We may cease to make settimeofday available to newly linked binaries after there is a replacement for Linux's time-zone-like offset API. hwclock had two calls to settimeofday, in functions to_sys_clock and set_system_clock_timezone, where both the arguments to settimeofday were valid (non-null). Therefore, split the call, once for timezone and once for timeval. Fixes #12756 Upstream-Status: Pending Signed-off-by: Sakib Sajal --- util-linux/hwclock.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/util-linux/hwclock.c b/util-linux/hwclock.c index 29f5102..088ab3b 100644 --- a/util-linux/hwclock.c +++ b/util-linux/hwclock.c @@ -131,8 +131,10 @@ static void to_sys_clock(const char **pp_rtcname, int utc) tv.tv_sec = read_rtc(pp_rtcname, NULL, utc); tv.tv_usec = 0; - if (settimeofday(&tv, &tz)) - bb_perror_msg_and_die("settimeofday"); + if (settimeofday(NULL, &tz)) + bb_perror_msg_and_die("settimeofday: timezone"); + if (settimeofday(&tv, NULL)) + bb_perror_msg_and_die("settimeofday: timeval"); } static void from_sys_clock(const char **pp_rtcname, int utc) @@ -283,8 +285,10 @@ static void set_system_clock_timezone(int utc) gettimeofday(&tv, NULL); if (!utc) tv.tv_sec += tz.tz_minuteswest * 60; - if (settimeofday(&tv, &tz)) - bb_perror_msg_and_die("settimeofday"); + if (settimeofday(NULL, &tz)) + bb_perror_msg_and_die("settimeofday: timezone"); + if (settimeofday(&tv, NULL)) + bb_perror_msg_and_die("settimeofday: timeval"); } //usage:#define hwclock_trivial_usage -- 2.27.0