user/sven/linux.git/kernel/time/timekeeping.c, branch v5.4.38

timekeeping/vsyscall: Prevent math overflow in BOOTTIME update

2019-08-23T00:12:11Z

The VDSO update for CLOCK_BOOTTIME has a overflow issue as it shifts the nanoseconds based boot time offset left by the clocksource shift. That overflows once the boot time offset becomes large enough. As a consequence CLOCK_BOOTTIME in the VDSO becomes a random number causing applications to misbehave. Fix it by storing a timespec64 representation of the offset when boot time is adjusted and add that to the MONOTONIC base time value in the vdso data page. Using the timespec64 representation avoids a 64bit division in the update code. Fixes: 44f57d788e7d ("timekeeping: Provide a generic update_vsyscall() implementation") Reported-by: Chris Clayton Signed-off-by: Thomas Gleixner Tested-by: Chris Clayton Tested-by: Vincenzo Frascino Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1908221257580.1983@nanos.tec.linutronix.de

timekeeping: Use proper ktime_add when adding nsecs in coarse offset

2019-06-22T10:11:27Z

While this doesn't actually amount to a real difference, since the macro evaluates to the same thing, every place else operates on ktime_t using these functions, so let's not break the pattern. Fixes: e3ff9c3678b4 ("timekeeping: Repair ktime_get_coarse*() granularity") Signed-off-by: Jason A. Donenfeld Signed-off-by: Thomas Gleixner Reviewed-by: Arnd Bergmann Link: https://lkml.kernel.org/r/20190621203249.3909-1-Jason@zx2c4.com

timekeeping: Repair ktime_get_coarse*() granularity

2019-06-14T09:51:44Z

Jason reported that the coarse ktime based time getters advance only once per second and not once per tick as advertised. The code reads only the monotonic base time, which advances once per second. The nanoseconds are accumulated on every tick in xtime_nsec up to a second and the regular time getters take this nanoseconds offset into account, but the ktime_get_coarse*() implementation fails to do so. Add the accumulated xtime_nsec value to the monotonic base time to get the proper per tick advancing coarse tinme. Fixes: b9ff604cff11 ("timekeeping: Add ktime_get_coarse_with_offset") Reported-by: Jason A. Donenfeld Signed-off-by: Thomas Gleixner Tested-by: Jason A. Donenfeld Cc: Arnd Bergmann Cc: Peter Zijlstra Cc: Clemens Ladisch Cc: Sultan Alsawaf Cc: Waiman Long Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1906132136280.1791@nanos.tec.linutronix.de

Merge tag 'audit-pr-20190507' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit

2019-05-08T02:06:04Z

Pull audit updates from Paul Moore: "We've got a reasonably broad set of audit patches for the v5.2 merge window, the highlights are below: - The biggest change, and the source of all the arch/* changes, is the patchset from Dmitry to help enable some of the work he is doing around PTRACE_GET_SYSCALL_INFO. To be honest, including this in the audit tree is a bit of a stretch, but it does help move audit a little further along towards proper syscall auditing for all arches, and everyone else seemed to agree that audit was a "good" spot for this to land (or maybe they just didn't want to merge it? dunno.). - We can now audit time/NTP adjustments. - We continue the work to connect associated audit records into a single event" * tag 'audit-pr-20190507' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit: (21 commits) audit: fix a memory leak bug ntp: Audit NTP parameters adjustment timekeeping: Audit clock adjustments audit: purge unnecessary list_empty calls audit: link integrity evm_write_xattrs record to syscall event syscall_get_arch: add "struct task_struct *" argument unicore32: define syscall_get_arch() Move EM_UNICORE to uapi/linux/elf-em.h nios2: define syscall_get_arch() nds32: define syscall_get_arch() Move EM_NDS32 to uapi/linux/elf-em.h m68k: define syscall_get_arch() hexagon: define syscall_get_arch() Move EM_HEXAGON to uapi/linux/elf-em.h h8300: define syscall_get_arch() c6x: define syscall_get_arch() arc: define syscall_get_arch() Move EM_ARCOMPACT and EM_ARCV2 to uapi/linux/elf-em.h audit: Make audit_log_cap and audit_copy_inode static audit: connect LOGIN record to its syscall record ...

ntp: Audit NTP parameters adjustment

2019-04-15T22:14:01Z

Emit an audit record every time selected NTP parameters are modified from userspace (via adjtimex(2) or clock_adjtime(2)). These parameters may be used to indirectly change system clock, and thus their modifications should be audited. Such events will now generate records of type AUDIT_TIME_ADJNTPVAL containing the following fields: - op -- which value was adjusted: - offset -- corresponding to the time_offset variable - freq -- corresponding to the time_freq variable - status -- corresponding to the time_status variable - adjust -- corresponding to the time_adjust variable - tick -- corresponding to the tick_usec variable - tai -- corresponding to the timekeeping's TAI offset - old -- the old value - new -- the new value Example records: type=TIME_ADJNTPVAL msg=audit(1530616044.507:7): op=status old=64 new=8256 type=TIME_ADJNTPVAL msg=audit(1530616044.511:11): op=freq old=0 new=49180377088000 The records of this type will be associated with the corresponding syscall records. An overview of parameter changes that can be done via do_adjtimex() (based on information from Miroslav Lichvar) and whether they are audited: __timekeeping_set_tai_offset() -- sets the offset from the International Atomic Time (AUDITED) NTP variables: time_offset -- can adjust the clock by up to 0.5 seconds per call and also speed it up or slow down by up to about 0.05% (43 seconds per day) (AUDITED) time_freq -- can speed up or slow down by up to about 0.05% (AUDITED) time_status -- can insert/delete leap seconds and it also enables/ disables synchronization of the hardware real-time clock (AUDITED) time_maxerror, time_esterror -- change error estimates used to inform userspace applications (NOT AUDITED) time_constant -- controls the speed of the clock adjustments that are made when time_offset is set (NOT AUDITED) time_adjust -- can temporarily speed up or slow down the clock by up to 0.05% (AUDITED) tick_usec -- a more extreme version of time_freq; can speed up or slow down the clock by up to 10% (AUDITED) Signed-off-by: Ondrej Mosnacek Reviewed-by: Richard Guy Briggs Reviewed-by: Thomas Gleixner Signed-off-by: Paul Moore

timekeeping: Audit clock adjustments

2019-04-15T22:10:17Z

Emit an audit record whenever the system clock is changed (i.e. shifted by a non-zero offset) by a syscall from userspace. The syscalls than can (at the time of writing) trigger such record are: - settimeofday(2), stime(2), clock_settime(2) -- via do_settimeofday64() - adjtimex(2), clock_adjtime(2) -- via do_adjtimex() The new records have type AUDIT_TIME_INJOFFSET and contain the following fields: - sec -- the 'seconds' part of the offset - nsec -- the 'nanoseconds' part of the offset Example record (time was shifted backwards by ~15.875 seconds): type=TIME_INJOFFSET msg=audit(1530616049.652:13): sec=-16 nsec=124887145 The records of this type will be associated with the corresponding syscall records. Signed-off-by: Ondrej Mosnacek Reviewed-by: Richard Guy Briggs Reviewed-by: Thomas Gleixner [PM: fixed a line width problem in __audit_tk_injoffset()] Signed-off-by: Paul Moore

timekeeping: Force upper bound for setting CLOCK_REALTIME

2019-03-28T12:41:06Z

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

timekeeping: Consistently use unsigned int for seqcount snapshot

2019-03-23T10:43:56Z

The timekeeping code uses a random mix of "unsigned long" and "unsigned int" for the seqcount snapshots (ratio 14:12). Since the seqlock.h API is entirely based on unsigned int, use that throughout. Signed-off-by: Rasmus Villemoes Signed-off-by: Thomas Gleixner Cc: Frederic Weisbecker Cc: John Stultz Cc: Stephen Boyd Link: https://lkml.kernel.org/r/20190318195557.20773-1-linux@rasmusvillemoes.dk

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

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()