blaster4385/linux-IllusionX/kernel/time, branch v6.12.10

clocksource: Make negative motion detection more robust

2024-12-14T19:04:16Z

commit 76031d9536a076bf023bedbdb1b4317fc801dd67 upstream. Guenter reported boot stalls on a emulated ARM 32-bit platform, which has a 24-bit wide clocksource. It turns out that the calculated maximal idle time, which limits idle sleeps to prevent clocksource wrap arounds, is close to the point where the negative motion detection triggers. max_idle_ns: 597268854 ns negative motion tripping point: 671088640 ns If the idle wakeup is delayed beyond that point, the clocksource advances far enough to trigger the negative motion detection. This prevents the clock to advance and in the worst case the system stalls completely if the consecutive sleeps based on the stale clock are delayed as well. Cure this by calculating a more robust cut-off value for negative motion, which covers 87.5% of the actual clocksource counter width. Compare the delta against this value to catch negative motion. This is specifically for clock sources with a small counter width as their wrap around time is close to the half counter width. For clock sources with wide counters this is not a problem because the maximum idle time is far from the half counter width due to the math overflow protection constraints. For the case at hand this results in a tripping point of 1174405120ns. Note, that this cannot prevent issues when the delay exceeds the 87.5% margin, but that's not different from the previous unchecked version which allowed arbitrary time jumps. Systems with small counter width are prone to invalid results, but this problem is unlikely to be seen on real hardware. If such a system completely stalls for more than half a second, then there are other more urgent problems than the counter wrapping around. Fixes: c163e40af9b2 ("timekeeping: Always check for negative motion") Reported-by: Guenter Roeck Signed-off-by: Thomas Gleixner Tested-by: Guenter Roeck Link: https://lore.kernel.org/all/8734j5ul4x.ffs@tglx Closes: https://lore.kernel.org/all/387b120b-d68a-45e8-b6ab-768cd95d11c2@roeck-us.net Signed-off-by: Greg Kroah-Hartman

timekeeping: Remove CONFIG_DEBUG_TIMEKEEPING

2024-12-14T19:04:16Z

commit d44d26987bb3df6d76556827097fc9ce17565cb8 upstream. Since 135225a363ae timekeeping_cycles_to_ns() handles large offsets which would lead to 64bit multiplication overflows correctly. It's also protected against negative motion of the clocksource unconditionally, which was exclusive to x86 before. timekeeping_advance() handles large offsets already correctly. That means the value of CONFIG_DEBUG_TIMEKEEPING which analyzed these cases is very close to zero. Remove all of it. Signed-off-by: Thomas Gleixner Acked-by: John Stultz Link: https://lore.kernel.org/all/20241031120328.536010148@linutronix.de Signed-off-by: Greg Kroah-Hartman

timekeeping: Always check for negative motion

2024-12-14T19:03:38Z

[ Upstream commit c163e40af9b2331b2c629fd4ec8b703ed4d4ae39 ] clocksource_delta() has two variants. One with a check for negative motion, which is only selected by x86. This is a historic leftover as this function was previously used in the time getter hot paths. Since 135225a363ae timekeeping_cycles_to_ns() has unconditional protection against this as a by-product of the protection against 64bit math overflow. clocksource_delta() is only used in the clocksource watchdog and in timekeeping_advance(). The extra conditional there is not hurting anyone. Remove the config option and unconditionally prevent negative motion of the readout. Signed-off-by: Thomas Gleixner Acked-by: John Stultz Link: https://lore.kernel.org/all/20241031120328.599430157@linutronix.de Signed-off-by: Sasha Levin

ntp: Remove invalid cast in time offset math

2024-12-14T19:03:12Z

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 Signed-off-by: Thomas Gleixner Cc: stable@vger.kernel.org Link: https://lore.kernel.org/all/SJ0P101MB03687BF7D5A10FD3C49C51E5F42E2@SJ0P101MB0368.NAMP101.PROD.OUTLOOK.COM Signed-off-by: Greg Kroah-Hartman

timers: Add missing READ_ONCE() in __run_timer_base()

2024-12-05T13:01:22Z

[ Upstream commit 1d4199cbbe95efaba51304cfd844bd0ccd224e61 ] __run_timer_base() checks base::next_expiry without holding base::lock. That can race with a remote CPU updating next_expiry under the lock. This is an intentional and harmless data race, but lacks a READ_ONCE(), so KCSAN complains about this. Add the missing READ_ONCE(). All other places are covered already. Fixes: 79f8b28e85f8 ("timers: Annotate possible non critical data race of next_expiry") Reported-by: kernel test robot Signed-off-by: Thomas Gleixner Reviewed-by: Frederic Weisbecker Link: https://lore.kernel.org/all/87a5emyqk0.ffs@tglx Closes: https://lore.kernel.org/oe-lkp/202410301205.ef8e9743-lkp@intel.com Signed-off-by: Sasha Levin

time: Fix references to _msecs_to_jiffies() handling of values

2024-12-05T13:01:22Z

[ Upstream commit 92b043fd995a63a57aae29ff85a39b6f30cd440c ] The details about the handling of the "normal" values were moved to the _msecs_to_jiffies() helpers in commit ca42aaf0c861 ("time: Refactor msecs_to_jiffies"). However, the same commit still mentioned __msecs_to_jiffies() in the added documentation. Thus point to _msecs_to_jiffies() instead. Fixes: ca42aaf0c861 ("time: Refactor msecs_to_jiffies") Signed-off-by: Miguel Ojeda Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/all/20241025110141.157205-2-ojeda@kernel.org Signed-off-by: Sasha Levin

time: Partially revert cleanup on msecs_to_jiffies() documentation

2024-12-05T13:01:22Z

[ Upstream commit b05aefc1f5886c8aece650c9c1639c87b976191a ] The documentation's intention is to compare msecs_to_jiffies() (first sentence) with __msecs_to_jiffies() (second sentence), which is what the original documentation did. One of the cleanups in commit f3cb80804b82 ("time: Fix various kernel-doc problems") may have thought the paragraph was talking about the latter since that is what it is being documented. Thus revert that part of the change. Fixes: f3cb80804b82 ("time: Fix various kernel-doc problems") Signed-off-by: Miguel Ojeda Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/all/20241025110141.157205-1-ojeda@kernel.org Signed-off-by: Sasha Levin

Merge tag 'net-6.12-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2024-10-24T23:43:50Z

Pull networking fixes from Paolo Abeni: "Including fixes from netfiler, xfrm and bluetooth. Oddly this includes a fix for a posix clock regression; in our previous PR we included a change there as a pre-requisite for networking one. That fix proved to be buggy and requires the follow-up included here. Thomas suggested we should send it, given we sent the buggy patch. Current release - regressions: - posix-clock: Fix unbalanced locking in pc_clock_settime() - netfilter: fix typo causing some targets not to load on IPv6 Current release - new code bugs: - xfrm: policy: remove last remnants of pernet inexact list Previous releases - regressions: - core: fix races in netdev_tx_sent_queue()/dev_watchdog() - bluetooth: fix UAF on sco_sock_timeout - eth: hv_netvsc: fix VF namespace also in synthetic NIC NETDEV_REGISTER event - eth: usbnet: fix name regression - eth: be2net: fix potential memory leak in be_xmit() - eth: plip: fix transmit path breakage Previous releases - always broken: - sched: deny mismatched skip_sw/skip_hw flags for actions created by classifiers - netfilter: bpf: must hold reference on net namespace - eth: virtio_net: fix integer overflow in stats - eth: bnxt_en: replace ptp_lock with irqsave variant - eth: octeon_ep: add SKB allocation failures handling in __octep_oq_process_rx() Misc: - MAINTAINERS: add Simon as an official reviewer" * tag 'net-6.12-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (40 commits) net: dsa: mv88e6xxx: support 4000ps cycle counter period net: dsa: mv88e6xxx: read cycle counter period from hardware net: dsa: mv88e6xxx: group cycle counter coefficients net: usb: qmi_wwan: add Fibocom FG132 0x0112 composition hv_netvsc: Fix VF namespace also in synthetic NIC NETDEV_REGISTER event net: dsa: microchip: disable EEE for KSZ879x/KSZ877x/KSZ876x Bluetooth: ISO: Fix UAF on iso_sock_timeout Bluetooth: SCO: Fix UAF on sco_sock_timeout Bluetooth: hci_core: Disable works on hci_unregister_dev posix-clock: posix-clock: Fix unbalanced locking in pc_clock_settime() r8169: avoid unsolicited interrupts net: sched: use RCU read-side critical section in taprio_dump() net: sched: fix use-after-free in taprio_change() net/sched: act_api: deny mismatched skip_sw/skip_hw flags for actions created by classifiers net: usb: usbnet: fix name regression mlxsw: spectrum_router: fix xa_store() error checking virtio_net: fix integer overflow in stats net: fix races in netdev_tx_sent_queue()/dev_watchdog() net: wwan: fix global oob in wwan_rtnl_policy netfilter: xtables: fix typo causing some targets not to load on IPv6 ...

posix-clock: posix-clock: Fix unbalanced locking in pc_clock_settime()

2024-10-23T14:05:01Z

If get_clock_desc() succeeds, it calls fget() for the clockid's fd, and get the clk->rwsem read lock, so the error path should release the lock to make the lock balance and fput the clockid's fd to make the refcount balance and release the fd related resource. However the below commit left the error path locked behind resulting in unbalanced locking. Check timespec64_valid_strict() before get_clock_desc() to fix it, because the "ts" is not changed after that. Fixes: d8794ac20a29 ("posix-clock: Fix missing timespec64 check in pc_clock_settime()") Acked-by: Richard Cochran Signed-off-by: Jinjie Ruan Acked-by: Anna-Maria Behnsen [pabeni@redhat.com: fixed commit message typo] Signed-off-by: Paolo Abeni

Merge tag 'sched_urgent_for_v6.12_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2024-10-20T18:30:56Z

Pull scheduling fixes from Borislav Petkov: - Add PREEMPT_RT maintainers - Fix another aspect of delayed dequeued tasks wrt determining their state, i.e., whether they're runnable or blocked - Handle delayed dequeued tasks and their migration wrt PSI properly - Fix the situation where a delayed dequeue task gets enqueued into a new class, which should not happen - Fix a case where memory allocation would happen while the runqueue lock is held, which is a no-no - Do not over-schedule when tasks with shorter slices preempt the currently running task - Make sure delayed to deque entities are properly handled before unthrottling - Other smaller cleanups and improvements * tag 'sched_urgent_for_v6.12_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: MAINTAINERS: Add an entry for PREEMPT_RT. sched/fair: Fix external p->on_rq users sched/psi: Fix mistaken CPU pressure indication after corrupted task state bug sched/core: Dequeue PSI signals for blocked tasks that are delayed sched: Fix delayed_dequeue vs switched_from_fair() sched/core: Disable page allocation in task_tick_mm_cid() sched/deadline: Use hrtick_enabled_dl() before start_hrtick_dl() sched/eevdf: Fix wakeup-preempt by checking cfs_rq->nr_running sched: Fix sched_delayed vs cfs_bandwidth