From f3d964673b2f1c5d5c68c77273efcf7103eed03b Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Mon, 29 Apr 2019 15:19:37 +0200 Subject: y2038: Make CONFIG_64BIT_TIME unconditional As Stepan Golosunov points out, there is a small mistake in the get_timespec64() function in the kernel. It was originally added under the assumption that CONFIG_64BIT_TIME would get enabled on all 32-bit and 64-bit architectures, but when the conversion was done, it was only turned on for 32-bit ones. The effect is that the get_timespec64() function never clears the upper half of the tv_nsec field for 32-bit tasks in compat mode. Clearing this is required for POSIX compliant behavior of functions that pass a 'timespec' structure with a 64-bit tv_sec and a 32-bit tv_nsec, plus uninitialized padding. The easiest fix for linux-5.1 is to just make the Kconfig symbol unconditional, as it was originally intended. As a follow-up, the #ifdef CONFIG_64BIT_TIME can be removed completely.. Note: for native 32-bit mode, no change is needed, this works as designed and user space should never need to clear the upper 32 bits of the tv_nsec field, in or out of the kernel. Fixes: 00bf25d693e7 ("y2038: use time32 syscall names on 32-bit") Signed-off-by: Arnd Bergmann Signed-off-by: Thomas Gleixner Cc: Joseph Myers Cc: libc-alpha@sourceware.org Cc: linux-api@vger.kernel.org Cc: Deepa Dinamani Cc: Lukasz Majewski Cc: Stepan Golosunov Link: https://lore.kernel.org/lkml/20190422090710.bmxdhhankurhafxq@sghpc.golosunov.pp.ru/ Link: https://lkml.kernel.org/r/20190429131951.471701-1-arnd@arndb.de --- arch/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/Kconfig b/arch/Kconfig index 33687dddd86a..9092e0ffe4d3 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -764,7 +764,7 @@ config COMPAT_OLD_SIGACTION bool config 64BIT_TIME - def_bool ARCH_HAS_64BIT_TIME + def_bool y help This should be selected by all architectures that need to support new system calls with a 64-bit time_t. This is relevant on all 32-bit -- cgit From fdc6bae940ee9eb869e493990540098b8c0fd6ab Mon Sep 17 00:00:00 2001 From: Miroslav Lichvar Date: Wed, 17 Apr 2019 10:48:33 +0200 Subject: ntp: Allow TAI-UTC offset to be set to zero The ADJ_TAI adjtimex mode sets the TAI-UTC offset of the system clock. It is typically set by NTP/PTP implementations and it is automatically updated by the kernel on leap seconds. The initial value is zero (which applications may interpret as unknown), but this value cannot be set by adjtimex. This limitation seems to go back to the original "nanokernel" implementation by David Mills. Change the ADJ_TAI check to accept zero as a valid TAI-UTC offset in order to allow setting it back to the initial value. Fixes: 153b5d054ac2 ("ntp: support for TAI") Suggested-by: Ondrej Mosnacek Signed-off-by: Miroslav Lichvar Signed-off-by: Thomas Gleixner Cc: John Stultz Cc: Richard Cochran Cc: Prarit Bhargava Link: https://lkml.kernel.org/r/20190417084833.7401-1-mlichvar@redhat.com --- kernel/time/ntp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c index 92a90014a925..f43d47c8c3b6 100644 --- a/kernel/time/ntp.c +++ b/kernel/time/ntp.c @@ -690,7 +690,7 @@ static inline void process_adjtimex_modes(const struct __kernel_timex *txc, time_constant = max(time_constant, 0l); } - if (txc->modes & ADJ_TAI && txc->constant > 0) + if (txc->modes & ADJ_TAI && txc->constant >= 0) *time_tai = txc->constant; if (txc->modes & ADJ_OFFSET) -- cgit