user/sven/linux.git/kernel/time/time.c, branch v5.1.10

timekeeping: Force upper bound for setting CLOCK_REALTIME

2019-05-31T13:43:46Z

[ Upstream commit 7a8e61f8478639072d402a26789055a4a4de8f77 ] Several people reported testing failures after setting CLOCK_REALTIME close to the limits of the kernel internal representation in nanoseconds, i.e. year 2262. The failures are exposed in subsequent operations, i.e. when arming timers or when the advancing CLOCK_MONOTONIC makes the calculation of CLOCK_REALTIME overflow into negative space. Now people start to paper over the underlying problem by clamping calculations to the valid range, but that's just wrong because such workarounds will prevent detection of real issues as well. It is reasonable to force an upper bound for the various methods of setting CLOCK_REALTIME. Year 2262 is the absolute upper bound. Assume a maximum uptime of 30 years which is plenty enough even for esoteric embedded systems. That results in an upper bound of year 2232 for setting the time. Once that limit is reached in reality this limit is only a small part of the problem space. But until then this stops people from trying to paper over the problem at the wrong places. Reported-by: Xiongfeng Wang Reported-by: Hongbo Yao Signed-off-by: Thomas Gleixner Cc: John Stultz Cc: Stephen Boyd Cc: Miroslav Lichvar Cc: Arnd Bergmann Cc: Richard Cochran Cc: Peter Zijlstra Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1903231125480.2157@nanos.tec.linutronix.de Signed-off-by: Sasha Levin

y2038: rename old time and utime syscalls

2019-02-06T23:13:28Z

The time, stime, utime, utimes, and futimesat system calls are only used on older architectures, and we do not provide y2038 safe variants of them, as they are replaced by clock_gettime64, clock_settime64, and utimensat_time64. However, for consistency it seems better to have the 32-bit architectures that still use them call the "time32" entry points (leaving the traditional handlers for the 64-bit architectures), like we do for system calls that now require two versions. Note: We used to always define __ARCH_WANT_SYS_TIME and __ARCH_WANT_SYS_UTIME and only set __ARCH_WANT_COMPAT_SYS_TIME and __ARCH_WANT_SYS_UTIME32 for compat mode on 64-bit kernels. Now this is reversed: only 64-bit architectures set __ARCH_WANT_SYS_TIME/UTIME, while we need __ARCH_WANT_SYS_TIME32/UTIME32 for 32-bit architectures and compat mode. The resulting asm/unistd.h changes look a bit counterintuitive. This is only a cleanup patch and it should not change any behavior. Signed-off-by: Arnd Bergmann Acked-by: Geert Uytterhoeven Acked-by: Heiko Carstens

y2038: syscalls: rename y2038 compat syscalls

2019-02-06T23:13:27Z

A lot of system calls that pass a time_t somewhere have an implementation using a COMPAT_SYSCALL_DEFINEx() on 64-bit architectures, and have been reworked so that this implementation can now be used on 32-bit architectures as well. The missing step is to redefine them using the regular SYSCALL_DEFINEx() to get them out of the compat namespace and make it possible to build them on 32-bit architectures. Any system call that ends in 'time' gets a '32' suffix on its name for that version, while the others get a '_time32' suffix, to distinguish them from the normal version, which takes a 64-bit time argument in the future. In this step, only 64-bit architectures are changed, doing this rename first lets us avoid touching the 32-bit architectures twice. Acked-by: Catalin Marinas Signed-off-by: Arnd Bergmann

timex: change syscalls to use struct __kernel_timex

2019-02-06T23:13:27Z

struct timex is not y2038 safe. Switch all the syscall apis to use y2038 safe __kernel_timex. Note that sys_adjtimex() does not have a y2038 safe solution. C libraries can implement it by calling clock_adjtime(CLOCK_REALTIME, ...). Signed-off-by: Deepa Dinamani Signed-off-by: Arnd Bergmann

timex: use __kernel_timex internally

2019-02-06T23:13:27Z

struct timex is not y2038 safe. Replace all uses of timex with y2038 safe __kernel_timex. Note that struct __kernel_timex is an ABI interface definition. We could define a new structure based on __kernel_timex that is only available internally instead. Right now, there isn't a strong motivation for this as the structure is isolated to a few defined struct timex interfaces and such a structure would be exactly the same as struct timex. The patch was generated by the following coccinelle script: virtual patch @depends on patch forall@ identifier ts; expression e; @@ ( - struct timex ts; + struct __kernel_timex ts; | - struct timex ts = {}; + struct __kernel_timex ts = {}; | - struct timex ts = e; + struct __kernel_timex ts = e; | - struct timex *ts; + struct __kernel_timex *ts; | (memset \| copy_from_user \| copy_to_user \)(..., - sizeof(struct timex)) + sizeof(struct __kernel_timex)) ) @depends on patch forall@ identifier ts; identifier fn; @@ fn(..., - struct timex *ts, + struct __kernel_timex *ts, ...) { ... } @depends on patch forall@ identifier ts; identifier fn; @@ fn(..., - struct timex *ts) { + struct __kernel_timex *ts) { ... } Signed-off-by: Deepa Dinamani Cc: linux-alpha@vger.kernel.org Cc: netdev@vger.kernel.org Signed-off-by: Arnd Bergmann

time: make adjtime compat handling available for 32 bit

2019-02-06T23:13:27Z

We want to reuse the compat_timex handling on 32-bit architectures the same way we are using the compat handling for timespec when moving to 64-bit time_t. Move all definitions related to compat_timex out of the compat code into the normal timekeeping code, along with a rename to old_timex32, corresponding to the timespec/timeval structures, and make it controlled by CONFIG_COMPAT_32BIT_TIME, which 32-bit architectures will then select. Signed-off-by: Arnd Bergmann

Merge tag 'y2038-for-4.21' of ssh://gitolite.kernel.org:/pub/scm/linux/kernel/git/arnd/playground

2018-12-28T20:45:04Z

Pull y2038 updates from Arnd Bergmann: "More syscalls and cleanups This concludes the main part of the system call rework for 64-bit time_t, which has spread over most of year 2018, the last six system calls being - ppoll - pselect6 - io_pgetevents - recvmmsg - futex - rt_sigtimedwait As before, nothing changes for 64-bit architectures, while 32-bit architectures gain another entry point that differs only in the layout of the timespec structure. Hopefully in the next release we can wire up all 22 of those system calls on all 32-bit architectures, which gives us a baseline version for glibc to start using them. This does not include the clock_adjtime, getrusage/waitid, and getitimer/setitimer system calls. I still plan to have new versions of those as well, but they are not required for correct operation of the C library since they can be emulated using the old 32-bit time_t based system calls. Aside from the system calls, there are also a few cleanups here, removing old kernel internal interfaces that have become unused after all references got removed. The arch/sh cleanups are part of this, there were posted several times over the past year without a reaction from the maintainers, while the corresponding changes made it into all other architectures" * tag 'y2038-for-4.21' of ssh://gitolite.kernel.org:/pub/scm/linux/kernel/git/arnd/playground: timekeeping: remove obsolete time accessors vfs: replace current_kernel_time64 with ktime equivalent timekeeping: remove timespec_add/timespec_del timekeeping: remove unused {read,update}_persistent_clock sh: remove board_time_init() callback sh: remove unused rtc_sh_get/set_time infrastructure sh: sh03: rtc: push down rtc class ops into driver sh: dreamcast: rtc: push down rtc class ops into driver y2038: signal: Add compat_sys_rt_sigtimedwait_time64 y2038: signal: Add sys_rt_sigtimedwait_time32 y2038: socket: Add compat_sys_recvmmsg_time64 y2038: futex: Add support for __kernel_timespec y2038: futex: Move compat implementation into futex.c io_pgetevents: use __kernel_timespec pselect6: use __kernel_timespec ppoll: use __kernel_timespec signal: Add restore_user_sigmask() signal: Add set_user_sigmask()

timekeeping: remove timespec_add/timespec_del

2018-12-18T15:13:05Z

The last users were removed a while ago since everyone moved to ktime_t, so we can remove the two unused interfaces for old timespec structures. With those two gone, set_normalized_timespec() is also unused, so remove that as well. Signed-off-by: Arnd Bergmann Acked-by: John Stultz

time: Add SPDX license identifiers

2018-11-23T10:51:20Z

Update the time(r) core files files with the correct SPDX license identifier based on the license text in the file itself. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This work is based on a script and data from Philippe Ombredanne, Kate Stewart and myself. The data has been created with two independent license scanners and manual inspection. The following files do not contain any direct license information and have been omitted from the big initial SPDX changes: timeconst.bc: The .bc files were not touched time.c, timer.c, timekeeping.c: Licence was deduced from EXPORT_SYMBOL_GPL As those files do not contain direct license references they fall under the project license, i.e. GPL V2 only. Signed-off-by: Thomas Gleixner Acked-by: Kees Cook Acked-by: Ingo Molnar Acked-by: John Stultz Acked-by: Corey Minyard Cc: Peter Zijlstra Cc: Kate Stewart Cc: Philippe Ombredanne Cc: Russell King Cc: Richard Cochran Cc: Nicolas Pitre Cc: David Riley Cc: Colin Cross Cc: Mark Brown Cc: H. Peter Anvin Cc: Paul E. McKenney Link: https://lkml.kernel.org/r/20181031182252.879109557@linutronix.de

time: Remove useless filenames in top level comments

2018-11-23T10:51:20Z

Remove the pointless filenames in the top level comments. They have no value at all and just occupy space. While at it tidy up some of the comments and remove a stale one. Signed-off-by: Thomas Gleixner Acked-by: Nicolas Pitre Acked-by: Kees Cook Acked-by: Ingo Molnar Acked-by: John Stultz Acked-by: Corey Minyard Cc: Peter Zijlstra Cc: Kate Stewart Cc: Philippe Ombredanne Cc: Peter Anvin Cc: Russell King Cc: Richard Cochran Cc: "Paul E. McKenney" Cc: David Riley Cc: Colin Cross Cc: Mark Brown Link: https://lkml.kernel.org/r/20181031182252.794898238@linutronix.de