| 文件 | 最后提交记录 | 最后更新时间 |
|---|---|---|
clocksource: Loosen clocksource watchdog constraints Currently, MAX_SKEW_USEC is set to 100 microseconds, which has worked reasonably well. However, NTP is willing to tolerate 500 microseconds of skew per second, and a clocksource that is good enough for NTP should be good enough for the clocksource watchdog. The watchdog's skew is controlled by MAX_SKEW_USEC and the CLOCKSOURCE_WATCHDOG_MAX_SKEW_US Kconfig option. However, these values are doubled before being associated with a clocksource's ->uncertainty_margin, and the ->uncertainty_margin values of the pair of clocksource's being compared are summed before checking against the skew. Therefore, set both MAX_SKEW_USEC and the default for the CLOCKSOURCE_WATCHDOG_MAX_SKEW_US Kconfig option to 125 microseconds of skew per second, resulting in 500 microseconds of skew per second in the clocksource watchdog's skew comparison. Suggested-by Rik van Riel <riel@surriel.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> | 3 年前 | |
time: Improve performance of time64_to_tm() The current implementation of time64_to_tm() contains unnecessary loops, branches and look-up tables. The new one uses an arithmetic-based algorithm appeared in [1] and is approximately 3x faster (YMMV). The drawback is that the new code isn't intuitive and contains many 'magic numbers' (not unusual for this type of algorithm). However, [1] justifies all those numbers and, given this function's history, the code is unlikely to need much maintenance, if any at all. Add a KUnit test for it which checks every day in a 160,000 years interval centered at 1970-01-01 against the expected result. [1] Neri, Schneider, "Euclidean Affine Functions and Applications to Calendar Algorithms". https://arxiv.org/abs/2102.06959 Signed-off-by: Cassio Neri <cassio.neri@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20210622213616.313046-1-cassio.neri@gmail.com | 5 年前 | |
alarmtimer: Fix argument order in alarm_timer_forward() commit 5d16467ae56343b9205caedf85e3a131e0914ad8 upstream. alarm_timer_forward() passes arguments to alarm_forward() in the wrong order: alarm_forward(alarm, timr->it_interval, now); However, alarm_forward() is defined as: u64 alarm_forward(struct alarm *alarm, ktime_t now, ktime_t interval); and uses the second argument as the current time: delta = ktime_sub(now, alarm->node.expires); Passing the interval as "now" results in incorrect delta computation, which can lead to missed expirations or incorrect overrun accounting. This issue has been present since the introduction of alarm_timer_forward(). Fix this by swapping the arguments. Fixes: e7561f1633ac ("alarmtimer: Implement forward callback") Signed-off-by: Zhan Xusheng <zhanxusheng@xiaomi.com> Signed-off-by: Thomas Gleixner <tglx@kernel.org> Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260323061130.29991-1-zhanxusheng@xiaomi.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> (cherry picked from commit c9e137c26cd4507f495e0b3319a3188607e764d3) Signed-off-by: Wentao Guan <guanwentao@uniontech.com> | 3 个月前 | |
clockevents: Repair kernel-doc for clockevent_delta2ns() Since the introduction of clockevents, i.e., commit d316c57ff6bf ("clockevents: add core functionality"), there has been a mismatch between the function and the kernel-doc comment for clockevent_delta2ns(). Hence, ./scripts/kernel-doc -none kernel/time/clockevents.c warns about it. Adjust the kernel-doc comment for clockevent_delta2ns() for make W=1 happiness. Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20221102091048.15068-1-lukas.bulwahn@gmail.com | 3 年前 | |
clocksource: Scale the watchdog read retries automatically [ Upstream commit 2ed08e4bc53298db3f87b528cd804cb0cce066a9 ] On a 8-socket server the TSC is wrongly marked as 'unstable' and disabled during boot time on about one out of 120 boot attempts: clocksource: timekeeping watchdog on CPU227: wd-tsc-wd excessive read-back delay of 153560ns vs. limit of 125000ns, wd-wd read-back delay only 11440ns, attempt 3, marking tsc unstable tsc: Marking TSC unstable due to clocksource watchdog TSC found unstable after boot, most likely due to broken BIOS. Use 'tsc=unstable'. sched_clock: Marking unstable (119294969739, 159204297)<-(125446229205, -5992055152) clocksource: Checking clocksource tsc synchronization from CPU 319 to CPUs 0,99,136,180,210,542,601,896. clocksource: Switched to clocksource hpet The reason is that for platform with a large number of CPUs, there are sporadic big or huge read latencies while reading the watchog/clocksource during boot or when system is under stress work load, and the frequency and maximum value of the latency goes up with the number of online CPUs. The cCurrent code already has logic to detect and filter such high latency case by reading the watchdog twice and checking the two deltas. Due to the randomness of the latency, there is a low probabilty that the first delta (latency) is big, but the second delta is small and looks valid. The watchdog code retries the readouts by default twice, which is not necessarily sufficient for systems with a large number of CPUs. There is a command line parameter 'max_cswd_read_retries' which allows to increase the number of retries, but that's not user friendly as it needs to be tweaked per system. As the number of required retries is proportional to the number of online CPUs, this parameter can be calculated at runtime. Scale and enlarge the number of retries according to the number of online CPUs and remove the command line parameter completely. [ tglx: Massaged change log and comments ] Signed-off-by: Feng Tang <feng.tang@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Jin Wang <jin1.wang@intel.com> Tested-by: Paul E. McKenney <paulmck@kernel.org> Reviewed-by: Waiman Long <longman@redhat.com> Reviewed-by: Paul E. McKenney <paulmck@kernel.org> Link: https://lore.kernel.org/r/20240221060859.1027450-1-feng.tang@intel.com Stable-dep-of: f2655ac2c06a ("clocksource: Fix brown-bag boolean thinko in cs_watchdog_read()") Signed-off-by: Sasha Levin <sashal@kernel.org> | 1 年前 | |
clocksource: Fix the CPUs' choice in the watchdog per CPU verification [ Upstream commit 08d7becc1a6b8c936e25d827becabfe3bff72a36 ] Right now, if the clocksource watchdog detects a clocksource skew, it might perform a per CPU check, for example in the TSC case on x86. In other words: supposing TSC is detected as unstable by the clocksource watchdog running at CPU1, as part of marking TSC unstable the kernel will also run a check of TSC readings on some CPUs to be sure it is synced between them all. But that check happens only on some CPUs, not all of them; this choice is based on the parameter "verify_n_cpus" and in some random cpumask calculation. So, the watchdog runs such per CPU checks on up to "verify_n_cpus" random CPUs among all online CPUs, with the risk of repeating CPUs (that aren't double checked) in the cpumask random calculation. But if "verify_n_cpus" > num_online_cpus(), it should skip the random calculation and just go ahead and check the clocksource sync between all online CPUs, without the risk of skipping some CPUs due to duplicity in the random cpumask calculation. Tests in a 4 CPU laptop with TSC skew detected led to some cases of the per CPU verification skipping some CPU even with verify_n_cpus=8, due to the duplicity on random cpumask generation. Skipping the randomization when the number of online CPUs is smaller than verify_n_cpus, solves that. Suggested-by: Thadeu Lima de Souza Cascardo <cascardo@igalia.com> Signed-off-by: Guilherme G. Piccoli <gpiccoli@igalia.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Paul E. McKenney <paulmck@kernel.org> Link: https://lore.kernel.org/all/20250323173857.372390-1-gpiccoli@igalia.com Signed-off-by: Sasha Levin <sashal@kernel.org> (cherry picked from commit 1c24a738971cb012ff7f450ca5656a52aeba6de3) | 1 年前 | |
hrtimer: Reduce trace noise in hrtimer_start() [ Upstream commit f2e388a019e4cf83a15883a3d1f1384298e9a6aa ] hrtimer_start() when invoked with an already armed timer traces like: <comm>-.. [032] d.h2. 5.002263: hrtimer_cancel: hrtimer= .... <comm>-.. [032] d.h1. 5.002263: hrtimer_start: hrtimer= .... Which is incorrect as the timer doesn't get canceled. Just the expiry time changes. The internal dequeue operation which is required for that is not really interesting for trace analysis. But it makes it tedious to keep real cancellations and the above case apart. Remove the cancel tracing in hrtimer_start() and add a 'was_armed' indicator to the hrtimer start tracepoint, which clearly indicates what the state of the hrtimer is when hrtimer_start() is invoked: <comm>-.. [032] d.h1. 6.200103: hrtimer_start: hrtimer= .... was_armed=0 <comm>-.. [032] d.h1. 6.200558: hrtimer_start: hrtimer= .... was_armed=1 Fixes: c6a2a1770245 ("hrtimer: Add tracepoint for hrtimers") Signed-off-by: Thomas Gleixner <tglx@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://patch.msgid.link/20260224163430.208491877@kernel.org Signed-off-by: Sasha Levin <sashal@kernel.org> (cherry picked from commit ca2d280b9b380608a710d720683b965c3dee546b) Signed-off-by: Wentao Guan <guanwentao@uniontech.com> | 2 个月前 | |
time: Prevent undefined behaviour in timespec64_to_ns() UBSAN reports: Undefined behaviour in ./include/linux/time64.h:127:27 signed integer overflow: 17179869187 * 1000000000 cannot be represented in type 'long long int' Call Trace: timespec64_to_ns include/linux/time64.h:127 [inline] set_cpu_itimer+0x65c/0x880 kernel/time/itimer.c:180 do_setitimer+0x8e/0x740 kernel/time/itimer.c:245 __x64_sys_setitimer+0x14c/0x2c0 kernel/time/itimer.c:336 do_syscall_64+0xa1/0x540 arch/x86/entry/common.c:295 Commit bd40a175769d ("y2038: itimer: change implementation to timespec64") replaced the original conversion which handled time clamping correctly with timespec64_to_ns() which has no overflow protection. Fix it in timespec64_to_ns() as this is not necessarily limited to the usage in itimers. [ tglx: Added comment and adjusted the fixes tag ] Fixes: 361a3bf00582 ("time64: Add time64.h header and define struct timespec64") Signed-off-by: Zeng Tao <prime.zeng@hisilicon.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/1598952616-6416-1-git-send-email-prime.zeng@hisilicon.com | 5 年前 | |
clocksource: Make clocksource watchdog test safe for slow-HZ systems The clocksource watchdog test sets a local JIFFIES_SHIFT macro and assumes that HZ is >= 100. For smaller HZ values this shift value is too large and causes undefined behaviour. Move the HZ-based definitions of JIFFIES_SHIFT from kernel/time/jiffies.c to kernel/time/tick-internal.h so the clocksource watchdog test can utilize them, which makes it work correctly with all HZ values. [ tglx: Resolved conflicts and massaged changelog ] Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/lkml/20210812000133.GA402890@paulmck-ThinkPad-P17-Gen-1/ | 4 年前 | |
vdso/timens: Refactor copy-pasted find_timens_vvar_page() helper into one copy find_timens_vvar_page() is not architecture-specific, as can be seen from how all five per-architecture versions of it are the same. (arm64, powerpc and riscv are exactly the same; x86 and s390 have two characters difference inside a comment, less blank lines, and mark the !CONFIG_TIME_NS version as inline.) Refactor the five copies into a central copy in kernel/time/namespace.c. Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20221130115320.2918447-1-jannh@google.com | 3 年前 | |
ntp: Remove invalid cast in time offset math commit f5807b0606da7ac7c1b74a386b22134ec7702d05 upstream. Due to an unsigned cast, adjtimex() returns the wrong offest when using ADJ_MICRO and the offset is negative. In this case a small negative offset returns approximately 4.29 seconds (~ 2^32/1000 milliseconds) due to the unsigned cast of the negative offset. This cast was added when the kernel internal struct timex was changed to use type long long for the time offset value to address the problem of a 64bit/32bit division on 32bit systems. The correct cast would have been (s32), which is correct as time_offset can only be in the range of [INT_MIN..INT_MAX] because the shift constant used for calculating it is 32. But that's non-obvious. Remove the cast and use div_s64() to cure the issue. [ tglx: Fix white space damage, use div_s64() and amend the change log ] Fixes: ead25417f82e ("timex: use __kernel_timex internally") Signed-off-by: Marcelo Dalmas <marcelo.dalmas@ge.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/all/SJ0P101MB03687BF7D5A10FD3C49C51E5F42E2@SJ0P101MB0368.NAMP101.PROD.OUTLOOK.COM Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 1 年前 | |
ntp: Make the RTC synchronization more reliable Miroslav reported that the periodic RTC synchronization in the NTP code fails more often than not to hit the specified update window. The reason is that the code uses delayed_work to schedule the update which needs to be in thread context as the underlying RTC might be connected via a slow bus, e.g. I2C. In the update function it verifies whether the current time is correct vs. the requirements of the underlying RTC. But delayed_work is using the timer wheel for scheduling which is inaccurate by design. Depending on the distance to the expiry the wheel gets less granular to allow batching and to avoid the cascading of the original timer wheel. See 500462a9de65 ("timers: Switch to a non-cascading wheel") and the code for further details. The code already deals with this by splitting the 660 seconds period into a long 659 seconds timer and then retrying with a smaller delta. But looking at the actual granularities of the timer wheel (which depend on the HZ configuration) the 659 seconds timer ends up in an outer wheel level and is affected by a worst case granularity of: HZ Granularity 1000 32s 250 16s 100 40s So the initial timer can be already off by max 12.5% which is not a big issue as the period of the sync is defined as ~11 minutes. The fine grained second attempt schedules to the desired update point with a timer expiring less than a second from now. Depending on the actual delta and the HZ setting even the second attempt can end up in outer wheel levels which have a large enough granularity to make the correctness check fail. As this is a fundamental property of the timer wheel there is no way to make this more accurate short of iterating in one jiffies steps towards the update point. Switch it to an hrtimer instead which schedules the actual update work. The hrtimer will expire precisely (max 1 jiffie delay when high resolution timers are not available). The actual scheduling delay of the work is the same as before. The update is triggered from do_adjtimex() which is a bit racy but not much more racy than it was before: if (ntp_synced()) queue_delayed_work(system_power_efficient_wq, &sync_work, 0); which is racy when the work is currently executed and has not managed to reschedule itself. This becomes now: if (ntp_synced() && !hrtimer_is_queued(&sync_hrtimer)) queue_work(system_power_efficient_wq, &sync_work, 0); which is racy when the hrtimer has expired and the work is currently executed and has not yet managed to rearm the hrtimer. Not a big problem as it just schedules work for nothing. The new implementation has a safe guard in place to catch the case where the hrtimer is queued on entry to the work function and avoids an extra update attempt of the RTC that way. Reported-by: Miroslav Lichvar <mlichvar@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Miroslav Lichvar <mlichvar@redhat.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Link: https://lore.kernel.org/r/20201206220542.062910520@linutronix.de | 5 年前 | |
ptp: Add PHC file mode checks. Allow RO adjtime() without FMODE_WRITE. [ Upstream commit b4e53b15c04e3852949003752f48f7a14ae39e86 ] Many devices implement highly accurate clocks, which the kernel manages as PTP Hardware Clocks (PHCs). Userspace applications rely on these clocks to timestamp events, trace workload execution, correlate timescales across devices, and keep various clocks in sync. The kernel’s current implementation of PTP clocks does not enforce file permissions checks for most device operations except for POSIX clock operations, where file mode is verified in the POSIX layer before forwarding the call to the PTP subsystem. Consequently, it is common practice to not give unprivileged userspace applications any access to PTP clocks whatsoever by giving the PTP chardevs 600 permissions. An example of users running into this limitation is documented in [1]. Additionally, POSIX layer requires WRITE permission even for readonly adjtime() calls which are used in PTP layer to return current frequency offset applied to the PHC. Add permission checks for functions that modify the state of a PTP device. Continue enforcing permission checks for POSIX clock operations (settime, adjtime) in the POSIX layer. Only require WRITE access for dynamic clocks adjtime() if any flags are set in the modes field. [1] https://lists.nwtime.org/sympa/arc/linuxptp-users/2024-01/msg00036.html Changes in v4: - Require FMODE_WRITE in ajtime() only for calls modifying the clock in any way. Acked-by: Richard Cochran <richardcochran@gmail.com> Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev> Signed-off-by: Wojtek Wasko <wwasko@nvidia.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> (cherry picked from commit 4fbfc6bca4e37c0b4c3ea521c196c7f9db2e2f14) Signed-off-by: Wentao Guan <guanwentao@uniontech.com> | 5 个月前 | |
posix-cpu-timers: Prevent UAF caused by non-leader exec() race commit 920f893f735e92ba3a1cd9256899a186b161928d upstream. Wongi and Jungwoo decoded and reported a non-leader exec() related race which can result in an UAF: sys_timer_delete() exec() posix_cpu_timer_del() // Observes old leader p = pid_task(pid, pid_type); de_thread() switch_leader(); release_task(old_leader) __exit_signal(old_leader) sighand = lock(old_leader, sighand); posix_cpu_timers*_exit(); sighand = lock_task_sighand(p) unhash_task(old_leader); sh = lock(p, sighand) old_leader->sighand = NULL; unlock(sighand); (p->sighand == NULL) unlock(sh) return NULL; // Returns without action if(!sighand) return 0; free_posix_timer(); This is "harmless" unless the deleted timer was armed and enqueued in p->signal because on exec() a TGID targeted timer is inherited. As sys_timer_delete() freed the underlying posix timer object run_posix_cpu_timers() or any timerqueue related add/delete operations on other timers will access the freed object's timerqueue node, which results in an UAF. There is a similar problem vs. posix_cpu_timer_set(). For regular posix timers it just transiently returns -ESRCH to user space, but for the use case in do_cpu_nanosleep() it's the same UAF just that the k_itimer is allocated on the stack. Also posix_cpu_timer_rearm() fails to rearm the timer, which means it stops to expire. While debating solutions Frederic pointed out another problem: posix_cpu_timer_del(tmr) __exit_signal(p) posix_cpu_timers*_exit(p); unhash_task(p); p->sighand = NULL; sh = lock_task_sighand(p) sighand = p->sighand; if (!sighand) return NULL; lock(sighand); if (!sh) WARN_ON_ONCE(timer_queued(tmr)); On weakly ordered architectures it is not guaranteed that posix_cpu_timer_del() will observe the stores in posix_cpu_timers*_exit() when p->sighand is observed as NULL, which means the WARN() can be a false positive. Solve these issues by: 1) Changing the store in __exit_signal() to smp_store_release(). 2) Adding a smp_acquire__after_ctrl_dep() into the !sighand path of lock_task_sighand(). 3) Creating a helper function for looking up the task and locking sighand which does not return when sighand == NULL. Instead it retries the task lookup and only if that fails it gives up. 4) Using that helper in the three affected functions. #1/#2 ensures that the reader side which observes sighand == NULL also observes all preceeding stores, i.e. the stores in posix_cpu_timers*_exit() and the ones in unhash_task(). #3 ensures that the above described non-leader exec() situation is handled gracefully. When the task lookup returns the old leader, but sighand == NULL then it retries. In the non-leader exec() case the subsequent task lookup will observe the new leader due to #1/#2. In normal exit() scenarios the subsequent lookup fails. When the task lookup fails, the function also checks whether the timer is still enqueued and issues a warning if that's the case. Unfortunately there is nothing which can be done about it, but as the task is already not longer visible the timer should not be accessed anymore. This check also requires memory ordering, which is not provided when the first lookup fails. To achieve that the check is preceeded by a smp_rmb() which pairs with the smp_wmb() in write_seqlock() in __exit_signal(). That ensures that the stores in posix_cpu_timers*_exit() are visible. The history of the non-leader exec() issue goes back to the early days of posix CPU timers, which stored a pointer to the group leader task in the timer. That obviously fails when a non-leader exec() switches the leader. commit e0a70217107e ("posix-cpu-timers: workaround to suppress the problems with mt exec") added a temporary workaround for that in 2010 which survived about 10 years. The fix for the workaround changed the task pointer to a pid pointer, but failed to see the subtle race described above. So the Fixes tag picks that commit, which seems to be halfways accurate. Thanks to Frederic Weissbecker, Oleg Nesterov and Peter Zijlstra for review, feedback and suggestions and to Wongi and Jungwoo for the excellent bug report and analysis! Fixes: 55e8c8eb2c7b ("posix-cpu-timers: Store a reference to a pid not a task") Reported-by: Wongi Lee <qw3rtyp0@gmail.com> Reported-by: Jungwoo Lee <jwlee2217@gmail.com> Signed-off-by: Thomas Gleixner <tglx@kernel.org> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Sasha Levin <sashal@kernel.org> (cherry picked from commit 12a891c773aeb5823d63dbd0cb2ab931d6c21c9b) Signed-off-by: Wentao Guan <guanwentao@uniontech.com> | 4 天前 | |
posix-timers: Get rid of [COMPAT_]SYS_NI() uses [ Upstream commit a4aebe936554dac6a91e5d091179c934f8325708 ] Only the posix timer system calls use this (when the posix timer support is disabled, which does not actually happen in any normal case), because they had debug code to print out a warning about missing system calls. Get rid of that special case, and just use the standard COND_SYSCALL interface that creates weak system call stubs that return -ENOSYS for when the system call does not exist. This fixes a kCFI issue with the SYS_NI() hackery: CFI failure at int80_emulation+0x67/0xb0 (target: sys_ni_posix_timers+0x0/0x70; expected type: 0xb02b34d9) WARNING: CPU: 0 PID: 48 at int80_emulation+0x67/0xb0 Reported-by: kernel test robot <oliver.sang@intel.com> Reviewed-by: Sami Tolvanen <samitolvanen@google.com> Tested-by: Sami Tolvanen <samitolvanen@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Borislav Petkov <bp@alien8.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> | 2 年前 | |
posix-timers: Add cond_resched() to posix_timer_add() search loop [ Upstream commit 5f2909c6cd13564a07ae692a95457f52295c4f22 ] With a large number of POSIX timers the search for a valid ID might cause a soft lockup on PREEMPT_NONE/VOLUNTARY kernels. Add cond_resched() to the loop to prevent that. [ tglx: Split out from Eric's series ] Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/all/20250214135911.2037402-2-edumazet@google.com Link: https://lore.kernel.org/all/20250308155623.635612865@linutronix.de Signed-off-by: Sasha Levin <sashal@kernel.org> (cherry picked from commit 6df3855868eb889e72b116242fef32d6cb29d4d4) | 1 年前 | |
posix-clocks: Introduce clock_get_ktime() callback The callsite in common_timer_get() has already a comment: /* * The timespec64 based conversion is suboptimal, but it's not * worth to implement yet another callback. */ kc->clock_get(timr->it_clock, &ts64); now = timespec64_to_ktime(ts64); The upcoming support for time namespaces requires to have access to: - The time in a task's time namespace for sys_clock_gettime() - The time in the root name space for common_timer_get() That adds a valid reason to finally implement a separate callback which returns the time in ktime_t format. Suggested-by: Thomas Gleixner <tglx@linutronix.de> Co-developed-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Andrei Vagin <avagin@gmail.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20191112012724.250792-10-dima@arista.com | 6 年前 | |
time/sched_clock: Provide sched_clock_noinstr() With the intent to provide local_clock_noinstr(), a variant of local_clock() that's safe to be called from noinstr code (with the assumption that any such code will already be non-preemptible), prepare for things by providing a noinstr sched_clock_noinstr() function. Specifically, preempt_enable_*() calls out to schedule(), which upsets noinstr validation efforts. As such, pull out the preempt_{dis,en}able_notrace() requirements from the sched_clock_read() implementations by explicitly providing it in the sched_clock() function. This further requires said sched_clock_read() functions to be noinstr themselves, for ARCH_WANTS_NO_INSTR users. See the next few patches. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Michael Kelley <mikelley@microsoft.com> # Hyper-V Link: https://lore.kernel.org/r/20230519102715.302350330@infradead.org | 3 年前 | |
time/debug: Fix memory leak with using debugfs_lookup() When calling debugfs_lookup() the result must have dput() called on it, otherwise the memory will leak over time. To make things simpler, just call debugfs_lookup_and_remove() instead which handles all of the logic at once. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20230202151214.2306822-1-gregkh@linuxfoundation.org | 3 年前 | |
time/tick-broadcast: Remove RCU_NONIDLE() usage No callers left that have already disabled RCU. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Tested-by: Tony Lindgren <tony@atomide.com> Tested-by: Ulf Hansson <ulf.hansson@linaro.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/20230112195540.927904612@infradead.org | 3 年前 | |
tick/broadcast: Move per CPU pointer access into the atomic section commit 6881e75237a84093d0986f56223db3724619f26e upstream. The recent fix for making the take over of the broadcast timer more reliable retrieves a per CPU pointer in preemptible context. This went unnoticed as compilers hoist the access into the non-preemptible region where the pointer is actually used. But of course it's valid that the compiler keeps it at the place where the code puts it which rightfully triggers: BUG: using smp_processor_id() in preemptible [00000000] code: caller is hotplug_cpu__broadcast_tick_pull+0x1c/0xc0 Move it to the actual usage site which is in a non-preemptible region. Fixes: f7d43dd206e7 ("tick/broadcast: Make takeover of broadcast hrtimer reliable") Reported-by: David Wang <00107082@163.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Yu Liao <liaoyu15@huawei.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/all/87ttg56ers.ffs@tglx Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 1 年前 | |
timekeeping: Add a lockdep override in tick_freeze() [ Upstream commit 92e250c624ea37fde64bfd624fd2556f0d846f18 ] tick_freeze() acquires a raw spinlock (tick_freeze_lock). Later in the callchain (timekeeping_suspend() -> mc146818_avoid_UIP()) the RTC driver acquires a spinlock which becomes a sleeping lock on PREEMPT_RT. Lockdep complains about this lock nesting. Add a lockdep override for this special case and a comment explaining why it is okay. Reported-by: Borislav Petkov <bp@alien8.de> Reported-by: Chris Bainbridge <chris.bainbridge@gmail.com> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/all/20250404133429.pnAzf-eF@linutronix.de Closes: https://lore.kernel.org/all/20250330113202.GAZ-krsjAnurOlTcp-@fat_crate.local/ Closes: https://lore.kernel.org/all/CAP-bSRZ0CWyZZsMtx046YV8L28LhY0fson2g4EqcwRAVN1Jk+Q@mail.gmail.com/ Signed-off-by: Sasha Levin <sashal@kernel.org> (cherry picked from commit dc18c5b1301a6fede7b26bebf621816f1a3a0fff) | 1 年前 | |
clocksource: Make clocksource watchdog test safe for slow-HZ systems The clocksource watchdog test sets a local JIFFIES_SHIFT macro and assumes that HZ is >= 100. For smaller HZ values this shift value is too large and causes undefined behaviour. Move the HZ-based definitions of JIFFIES_SHIFT from kernel/time/jiffies.c to kernel/time/tick-internal.h so the clocksource watchdog test can utilize them, which makes it work correctly with all HZ values. [ tglx: Resolved conflicts and massaged changelog ] Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/lkml/20210812000133.GA402890@paulmck-ThinkPad-P17-Gen-1/ | 4 年前 | |
timekeeping: remove xtime_update There are no more users of xtime_update aside from legacy_timer_tick(), so fold it into that function and remove the declaration. update_process_times() is now only called inside of the kernel/time/ code, so the declaration can be moved there. Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org> Tested-by: Geert Uytterhoeven <geert@linux-m68k.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de> | 5 年前 | |
time: Fix various kernel-doc problems Clean up kernel-doc complaints about function names and non-kernel-doc comments in kernel/time/. Fixes these warnings: kernel/time/time.c:479: warning: expecting prototype for set_normalized_timespec(). Prototype was for set_normalized_timespec64() instead kernel/time/time.c:553: warning: expecting prototype for msecs_to_jiffies(). Prototype was for __msecs_to_jiffies() instead kernel/time/timekeeping.c:1595: warning: contents before sections kernel/time/timekeeping.c:1705: warning: This comment starts with '/**', but isn't a kernel-doc comment. * We have three kinds of time sources to use for sleep time kernel/time/timekeeping.c:1726: warning: This comment starts with '/**', but isn't a kernel-doc comment. * 1) can be determined whether to use or not only when doing kernel/time/tick-oneshot.c:21: warning: missing initial short description on line: * tick_program_event kernel/time/tick-oneshot.c:107: warning: expecting prototype for tick_check_oneshot_mode(). Prototype was for tick_oneshot_mode_active() instead Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20230103032849.12723-1-rdunlap@infradead.org | 3 年前 | |
sched/fair: Fix external p->on_rq users mainline inclusion from mainline-v6.12-rc4 category: feature note: patch series end in ("sched/eevdf: Fix se->slice being set to U64_MAX and resulting crash"), in middle may boot crash! Sean noted that ever since commit 152e11f6df29 ("sched/fair: Implement delayed dequeue") KVM's preemption notifiers have started mis-classifying preemption vs blocking. Notably p->on_rq is no longer sufficient to determine if a task is runnable or blocked -- the aforementioned commit introduces tasks that remain on the runqueue even through they will not run again, and should be considered blocked for many cases. Add the task_is_runnable() helper to classify things and audit all external users of the p->on_rq state. Also add a few comments. Fixes: 152e11f6df29 ("sched/fair: Implement delayed dequeue") Reported-by: Sean Christopherson <seanjc@google.com> Tested-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lkml.kernel.org/r/20241010091843.GK33184@noisy.programming.kicks-ass.net (cherry picked from commit cd9626e9ebc77edec33023fe95dab4b04ffc819d) Signed-off-by: Wentao Guan <guanwentao@uniontech.com> Conflicts: virt/kvm/kvm_main.c | 10 个月前 | |
tick: Move got_idle_tick away from common flags [ Upstream commit 3ce74f1a8566dbbc9774f85fb0ce781fe290fd32 ] tick_nohz_idle_got_tick() is called by cpuidle_reflect() within the idle loop with interrupts enabled. This function modifies the struct tick_sched's bitfield "got_idle_tick". However this bitfield is stored within the same mask as other bitfields that can be modified from interrupts. Fortunately so far it looks like the only race that can happen is while writing ->got_idle_tick to 0, an interrupt fires and writes the ->idle_active field to 0. It's then possible that the interrupted write to ->got_idle_tick writes back the old value of ->idle_active back to 1. However if that happens, the worst possible outcome is that the time spent between that interrupt and the upcoming call to tick_nohz_idle_exit() is accounted as idle, which is negligible quantity. Still all the bitfield writes within this struct tick_sched's shadow mask should be IRQ-safe. Therefore move this bitfield out to its own storage to avoid further suprises. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20240225225508.11587-12-frederic@kernel.org Signed-off-by: Sasha Levin <sashal@kernel.org> | 1 年前 | |
time: Fix off-by-one in compat settimeofday() usec validation commit 269f2b43fae692d1f3988c9f888a6301aa537b82 upstream. The compat version of settimeofday() uses '>' instead of '>=' when validating tv_usec against USEC_PER_SEC, allowing the value 1000000 to pass the check. After the subsequent conversion to nanoseconds (tv_nsec *= NSEC_PER_USEC), this results in tv_nsec == NSEC_PER_SEC, which violates the timespec invariant that tv_nsec must be strictly less than NSEC_PER_SEC. The native settimeofday() was already fixed in commit ce4abda5e126 ("time: Fix off-by-one in settimeofday() usec validation"), but the compat counterpart was missed. Fix it by using '>=' to reject tv_usec values outside the valid range [0, USEC_PER_SEC - 1]. Fixes: 5e0fb1b57bea ("y2038: time: avoid timespec usage in settimeofday()") Signed-off-by: Wang Yan <wangyan01@kylinos.cn> Signed-off-by: Thomas Gleixner <tglx@kernel.org> Acked-by: Arnd Bergmann <arnd@arndb.de> Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260622103348.120255-1-wangyan01@kylinos.cn Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> (cherry picked from commit 64b4197d013bf24b563ab57bd3fcdc6529a5a0b6) Signed-off-by: Wentao Guan <guanwentao@uniontech.com> | 7 天前 | |
time: test: Fix incorrect format specifier [ Upstream commit 133e267ef4a26d19c93996a874714e9f3f8c70aa ] 'days' is a s64 (from div_s64), and so should use a %lld specifier. This was found by extending KUnit's assertion macros to use gcc's __printf attribute. Fixes: 276010551664 ("time: Improve performance of time64_to_tm()") Signed-off-by: David Gow <davidgow@google.com> Tested-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Justin Stitt <justinstitt@google.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> | 2 年前 | |
time: Add SPDX license identifiers 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 <tglx@linutronix.de> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Ingo Molnar <mingo@kernel.org> Acked-by: John Stultz <john.stultz@linaro.org> Acked-by: Corey Minyard <cminyard@mvista.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: Philippe Ombredanne <pombredanne@nexb.com> Cc: Russell King <rmk+kernel@armlinux.org.uk> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Nicolas Pitre <nicolas.pitre@linaro.org> Cc: David Riley <davidriley@chromium.org> Cc: Colin Cross <ccross@android.com> Cc: Mark Brown <broonie@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Link: https://lkml.kernel.org/r/20181031182252.879109557@linutronix.de | 7 年前 | |
time: Improve performance of time64_to_tm() The current implementation of time64_to_tm() contains unnecessary loops, branches and look-up tables. The new one uses an arithmetic-based algorithm appeared in [1] and is approximately 3x faster (YMMV). The drawback is that the new code isn't intuitive and contains many 'magic numbers' (not unusual for this type of algorithm). However, [1] justifies all those numbers and, given this function's history, the code is unlikely to need much maintenance, if any at all. Add a KUnit test for it which checks every day in a 160,000 years interval centered at 1970-01-01 against the expected result. [1] Neri, Schneider, "Euclidean Affine Functions and Applications to Calendar Algorithms". https://arxiv.org/abs/2102.06959 Signed-off-by: Cassio Neri <cassio.neri@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20210622213616.313046-1-cassio.neri@gmail.com | 5 年前 | |
time/timecounter: Mark 1st argument of timecounter_cyc2time() as const The timecounter is not modified in this function. Mark it as const. Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20210303103544.994855-1-mkl@pengutronix.de | 5 年前 | |
timekeeping: Fix bogus clock_was_set() invocation in do_adjtimex() commit 5916be8a53de6401871bdd953f6c60237b47d6d3 upstream. The addition of the bases argument to clock_was_set() fixed up all call sites correctly except for do_adjtimex(). This uses CLOCK_REALTIME instead of CLOCK_SET_WALL as argument. CLOCK_REALTIME is 0. As a result the effect of that clock_was_set() notification is incomplete and might result in timers expiring late because the hrtimer code does not re-evaluate the affected clock bases. Use CLOCK_SET_WALL instead of CLOCK_REALTIME to tell the hrtimers code which clock bases need to be re-evaluated. Fixes: 17a1b8826b45 ("hrtimer: Add bases argument to clock_was_set()") Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/all/877ccx7igo.ffs@tglx Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 1 年前 | |
Merge tag 'asm-generic-timers-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic Pull asm-generic cross-architecture timer cleanup from Arnd Bergmann: "This cleans up two ancient timer features that were never completed in the past, CONFIG_GENERIC_CLOCKEVENTS and CONFIG_ARCH_USES_GETTIMEOFFSET. There was only one user left for the ARCH_USES_GETTIMEOFFSET variant of clocksource implementations, the ARM EBSA110 platform. Rather than changing to use modern timekeeping, we remove the platform entirely as Russell no longer uses his machine and nobody else seems to have one any more. The conditional code for using arch_gettimeoffset() is removed as a result. For CONFIG_GENERIC_CLOCKEVENTS, there are still a couple of platforms not using clockevent drivers: parisc, ia64, most of m68k, and one Arm platform. These all do timer ticks slighly differently, and this gets cleaned up to the point they at least all call the same helper function. Instead of most platforms using 'select GENERIC_CLOCKEVENTS' in Kconfig, the polarity is now reversed, with the few remaining ones selecting LEGACY_TIMER_TICK instead" * tag 'asm-generic-timers-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: timekeeping: default GENERIC_CLOCKEVENTS to enabled timekeeping: remove xtime_update m68k: remove timer_interrupt() function m68k: change remaining timers to legacy_timer_tick m68k: m68328: use legacy_timer_tick() m68k: sun3/sun3c: use legacy_timer_tick m68k: split heartbeat out of timer function m68k: coldfire: use legacy_timer_tick() parisc: use legacy_timer_tick ARM: rpc: use legacy_timer_tick ia64: convert to legacy_timer_tick timekeeping: add CONFIG_LEGACY_TIMER_TICK timekeeping: remove arch_gettimeoffset net: remove am79c961a driver ARM: remove ebsa110 platform | 5 年前 | |
timekeeping/debug: No need to check return value of debugfs_create functions When calling debugfs functions, there is no need to ever check the return value. The function can work or not, but the code logic should never do something different based on this. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: John Stultz <john.stultz@linaro.org> Cc: Stephen Boyd <sboyd@kernel.org> Link: https://lkml.kernel.org/r/20190122152151.16139-43-gregkh@linuxfoundation.org | 7 年前 | |
timekeeping/vsyscall: Provide vdso_update_begin/end() Architectures can have the requirement to add additional architecture specific data to the VDSO data page which needs to be updated independent of the timekeeper updates. To protect these updates vs. concurrent readers and a conflicting update through timekeeping, provide helper functions to make such updates safe. vdso_update_begin() takes the timekeeper_lock to protect against a potential update from timekeeper code and increments the VDSO sequence count to signal data inconsistency to concurrent readers. vdso_update_end() makes the sequence count even again to signal data consistency and drops the timekeeper lock. [ Sven: Add interrupt disable handling to the functions ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200804150124.41692-3-svens@linux.ibm.com | 5 年前 | |
timekeeping: Remove the now superfluous sentinel elements from ctl_table array mainline inclusion from mainline-v6.10-rc1 category: performance This commit comes at the tail end of a greater effort to remove the empty elements at the end of the ctl_table arrays (sentinels) which will reduce the overall build time size of the kernel and run time memory bloat by ~64 bytes per sentinel (further information Link : https://lore.kernel.org/all/ZO5Yx5JFogGi%2FcBo@bombadil.infradead.org/) Remove sentinel element from time_sysctl Signed-off-by: Joel Granados <j.granados@samsung.com> (cherry picked from commit fe6fc8e11b5a118a299c0d8f06407794173e6aa9) Signed-off-by: Wentao Guan <guanwentao@uniontech.com> | 1 个月前 | |
timer_list: Don't use %pK through printk() [ Upstream commit a52067c24ccf6ee4c85acffa0f155e9714f9adce ] This reverts commit f590308536db ("timer debug: Hide kernel addresses via %pK in /proc/timer_list") The timer list helper SEQ_printf() uses either the real seq_printf() for procfs output or vprintk() to print to the kernel log, when invoked from SysRq-q. It uses %pK for printing pointers. In the past %pK was prefered over %p as it would not leak raw pointer values into the kernel log. Since commit ad67b74d2469 ("printk: hash addresses printed with %p") the regular %p has been improved to avoid this issue. Furthermore, restricted pointers ("%pK") were never meant to be used through printk(). They can still unintentionally leak raw pointers or acquire sleeping looks in atomic contexts. Switch to the regular pointer formatting which is safer, easier to reason about and sufficient here. Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/lkml/20250113171731-dc10e3c1-da64-4af0-b767-7c7070468023@linutronix.de/ Link: https://lore.kernel.org/all/20250311-restricted-pointers-timer-v1-1-6626b91e54ab@linutronix.de Signed-off-by: Sasha Levin <sashal@kernel.org> (cherry picked from commit da36c3ad7c1772ac9338632a0698cb8c29a3c927) | 1 年前 | |
timekeeping, clocksource: Fix various typos in comments Fix ~56 single-word typos in timekeeping & clocksource code comments. Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: John Stultz <john.stultz@linaro.org> Cc: Stephen Boyd <sboyd@kernel.org> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: linux-kernel@vger.kernel.org | 5 年前 |
| 文件 | 最后提交记录 | 最后更新时间 |
|---|---|---|
| 3 年前 | ||
| 5 年前 | ||
| 3 个月前 | ||
| 3 年前 | ||
| 1 年前 | ||
| 1 年前 | ||
| 2 个月前 | ||
| 5 年前 | ||
| 4 年前 | ||
| 3 年前 | ||
| 1 年前 | ||
| 5 年前 | ||
| 5 个月前 | ||
| 4 天前 | ||
| 2 年前 | ||
| 1 年前 | ||
| 6 年前 | ||
| 3 年前 | ||
| 3 年前 | ||
| 3 年前 | ||
| 1 年前 | ||
| 1 年前 | ||
| 4 年前 | ||
| 5 年前 | ||
| 3 年前 | ||
| 10 个月前 | ||
| 1 年前 | ||
| 7 天前 | ||
| 2 年前 | ||
| 7 年前 | ||
| 5 年前 | ||
| 5 年前 | ||
| 1 年前 | ||
| 5 年前 | ||
| 7 年前 | ||
| 5 年前 | ||
| 1 个月前 | ||
| 1 年前 | ||
| 5 年前 |