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* time: Correct the prototype of ns_to_kernel_old_timeval and ns_to_timespec64Youngmin Nam2022-08-091-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | In ns_to_kernel_old_timeval() definition, the function argument is defined with const identifier in kernel/time/time.c, but the prototype in include/linux/time32.h looks different. - The function is defined in kernel/time/time.c as below: struct __kernel_old_timeval ns_to_kernel_old_timeval(const s64 nsec) - The function is decalared in include/linux/time32.h as below: extern struct __kernel_old_timeval ns_to_kernel_old_timeval(s64 nsec); Because the variable of arithmethic types isn't modified in the calling scope, there's no need to mark arguments as const, which was already mentioned during review (Link[1) of the original patch. Likewise remove the "const" keyword in both definition and declaration of ns_to_timespec64() as requested by Arnd (Link[2]). Fixes: a84d1169164b ("y2038: Introduce struct __kernel_old_timeval") Signed-off-by: Youngmin Nam <youngmin.nam@samsung.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Link: https://lore.kernel.org/all/20220712094715.2918823-1-youngmin.nam@samsung.com Link[1]: https://lore.kernel.org/all/20180310081123.thin6wphgk7tongy@gmail.com/ Link[2]: https://lore.kernel.org/all/CAK8P3a3nknJgEDESGdJH91jMj6R_xydFqWASd8r5BbesdvMBgA@mail.gmail.com/
* posix-timers: Make do_clock_gettime() staticJiri Slaby2022-08-061-1/+2
| | | | | | | | | | | do_clock_gettime() is used only in posix-stubs.c, so make it static. It avoids a compiler warning too: time/posix-stubs.c:73:5: warning: no previous prototype for ‘do_clock_gettime’ [-Wmissing-prototypes] Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20220719085620.30567-1-jslaby@suse.cz
* Merge tag 'net-next-6.0' of ↵Linus Torvalds2022-08-031-0/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next Pull networking changes from Paolo Abeni: "Core: - Refactor the forward memory allocation to better cope with memory pressure with many open sockets, moving from a per socket cache to a per-CPU one - Replace rwlocks with RCU for better fairness in ping, raw sockets and IP multicast router. - Network-side support for IO uring zero-copy send. - A few skb drop reason improvements, including codegen the source file with string mapping instead of using macro magic. - Rename reference tracking helpers to a more consistent netdev_* schema. - Adapt u64_stats_t type to address load/store tearing issues. - Refine debug helper usage to reduce the log noise caused by bots. BPF: - Improve socket map performance, avoiding skb cloning on read operation. - Add support for 64 bits enum, to match types exposed by kernel. - Introduce support for sleepable uprobes program. - Introduce support for enum textual representation in libbpf. - New helpers to implement synproxy with eBPF/XDP. - Improve loop performances, inlining indirect calls when possible. - Removed all the deprecated libbpf APIs. - Implement new eBPF-based LSM flavor. - Add type match support, which allow accurate queries to the eBPF used types. - A few TCP congetsion control framework usability improvements. - Add new infrastructure to manipulate CT entries via eBPF programs. - Allow for livepatch (KLP) and BPF trampolines to attach to the same kernel function. Protocols: - Introduce per network namespace lookup tables for unix sockets, increasing scalability and reducing contention. - Preparation work for Wi-Fi 7 Multi-Link Operation (MLO) support. - Add support to forciby close TIME_WAIT TCP sockets via user-space tools. - Significant performance improvement for the TLS 1.3 receive path, both for zero-copy and not-zero-copy. - Support for changing the initial MTPCP subflow priority/backup status - Introduce virtually contingus buffers for sockets over RDMA, to cope better with memory pressure. - Extend CAN ethtool support with timestamping capabilities - Refactor CAN build infrastructure to allow building only the needed features. Driver API: - Remove devlink mutex to allow parallel commands on multiple links. - Add support for pause stats in distributed switch. - Implement devlink helpers to query and flash line cards. - New helper for phy mode to register conversion. New hardware / drivers: - Ethernet DSA driver for the rockchip mt7531 on BPI-R2 Pro. - Ethernet DSA driver for the Renesas RZ/N1 A5PSW switch. - Ethernet DSA driver for the Microchip LAN937x switch. - Ethernet PHY driver for the Aquantia AQR113C EPHY. - CAN driver for the OBD-II ELM327 interface. - CAN driver for RZ/N1 SJA1000 CAN controller. - Bluetooth: Infineon CYW55572 Wi-Fi plus Bluetooth combo device. Drivers: - Intel Ethernet NICs: - i40e: add support for vlan pruning - i40e: add support for XDP framented packets - ice: improved vlan offload support - ice: add support for PPPoE offload - Mellanox Ethernet (mlx5) - refactor packet steering offload for performance and scalability - extend support for TC offload - refactor devlink code to clean-up the locking schema - support stacked vlans for bridge offloads - use TLS objects pool to improve connection rate - Netronome Ethernet NICs (nfp): - extend support for IPv6 fields mangling offload - add support for vepa mode in HW bridge - better support for virtio data path acceleration (VDPA) - enable TSO by default - Microsoft vNIC driver (mana) - add support for XDP redirect - Others Ethernet drivers: - bonding: add per-port priority support - microchip lan743x: extend phy support - Fungible funeth: support UDP segmentation offload and XDP xmit - Solarflare EF100: add support for virtual function representors - MediaTek SoC: add XDP support - Mellanox Ethernet/IB switch (mlxsw): - dropped support for unreleased H/W (XM router). - improved stats accuracy - unified bridge model coversion improving scalability (parts 1-6) - support for PTP in Spectrum-2 asics - Broadcom PHYs - add PTP support for BCM54210E - add support for the BCM53128 internal PHY - Marvell Ethernet switches (prestera): - implement support for multicast forwarding offload - Embedded Ethernet switches: - refactor OcteonTx MAC filter for better scalability - improve TC H/W offload for the Felix driver - refactor the Microchip ksz8 and ksz9477 drivers to share the probe code (parts 1, 2), add support for phylink mac configuration - Other WiFi: - Microchip wilc1000: diable WEP support and enable WPA3 - Atheros ath10k: encapsulation offload support Old code removal: - Neterion vxge ethernet driver: this is untouched since more than 10 years" * tag 'net-next-6.0' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1890 commits) doc: sfp-phylink: Fix a broken reference wireguard: selftests: support UML wireguard: allowedips: don't corrupt stack when detecting overflow wireguard: selftests: update config fragments wireguard: ratelimiter: use hrtimer in selftest net/mlx5e: xsk: Discard unaligned XSK frames on striding RQ net: usb: ax88179_178a: Bind only to vendor-specific interface selftests: net: fix IOAM test skip return code net: usb: make USB_RTL8153_ECM non user configurable net: marvell: prestera: remove reduntant code octeontx2-pf: Reduce minimum mtu size to 60 net: devlink: Fix missing mutex_unlock() call net/tls: Remove redundant workqueue flush before destroy net: txgbe: Fix an error handling path in txgbe_probe() net: dsa: Fix spelling mistakes and cleanup code Documentation: devlink: add add devlink-selftests to the table of contents dccp: put dccp_qpolicy_full() and dccp_qpolicy_push() in the same lock net: ionic: fix error check for vlan flags in ionic_set_nic_features() net: ice: fix error NETIF_F_HW_VLAN_CTAG_FILTER check in ice_vsi_sync_fltr() nfp: flower: add support for tunnel offload without key ID ...
| * wireguard: ratelimiter: use hrtimer in selftestJason A. Donenfeld2022-08-021-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Using msleep() is problematic because it's compared against ratelimiter.c's ktime_get_coarse_boottime_ns(), which means on systems with slow jiffies (such as UML's forced HZ=100), the result is inaccurate. So switch to using schedule_hrtimeout(). However, hrtimer gives us access only to the traditional posix timers, and none of the _COARSE variants. So now, rather than being too imprecise like jiffies, it's too precise. One solution would be to give it a large "range" value, but this will still fire early on a loaded system. A better solution is to align the timeout to the actual coarse timer, and then round up to the nearest tick, plus change. So add the timeout to the current coarse time, and then schedule_hrtimer() until the absolute computed time. This should hopefully reduce flakes in CI as well. Note that we keep the retry loop in case the entire function is running behind, because the test could still be scheduled out, by either the kernel or by the hypervisor's kernel, in which case restarting the test and hoping to not be scheduled out still helps. Fixes: e7096c131e51 ("net: WireGuard secure network tunnel") Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* | Merge tag 'rcu.2022.07.26a' of ↵Linus Torvalds2022-08-022-12/+27
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu Pull RCU updates from Paul McKenney: - Documentation updates - Miscellaneous fixes - Callback-offload updates, perhaps most notably a new RCU_NOCB_CPU_DEFAULT_ALL Kconfig option that causes all CPUs to be offloaded at boot time, regardless of kernel boot parameters. This is useful to battery-powered systems such as ChromeOS and Android. In addition, a new RCU_NOCB_CPU_CB_BOOST kernel boot parameter prevents offloaded callbacks from interfering with real-time workloads and with energy-efficiency mechanisms - Polled grace-period updates, perhaps most notably making these APIs account for both normal and expedited grace periods - Tasks RCU updates, perhaps most notably reducing the CPU overhead of RCU tasks trace grace periods by more than a factor of two on a system with 15,000 tasks. The reduction is expected to increase with the number of tasks, so it seems reasonable to hypothesize that a system with 150,000 tasks might see a 20-fold reduction in CPU overhead - Torture-test updates - Updates that merge RCU's dyntick-idle tracking into context tracking, thus reducing the overhead of transitioning to kernel mode from either idle or nohz_full userspace execution for kernels that track context independently of RCU. This is expected to be helpful primarily for kernels built with CONFIG_NO_HZ_FULL=y * tag 'rcu.2022.07.26a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu: (98 commits) rcu: Add irqs-disabled indicator to expedited RCU CPU stall warnings rcu: Diagnose extended sync_rcu_do_polled_gp() loops rcu: Put panic_on_rcu_stall() after expedited RCU CPU stall warnings rcutorture: Test polled expedited grace-period primitives rcu: Add polled expedited grace-period primitives rcutorture: Verify that polled GP API sees synchronous grace periods rcu: Make Tiny RCU grace periods visible to polled APIs rcu: Make polled grace-period API account for expedited grace periods rcu: Switch polled grace-period APIs to ->gp_seq_polled rcu/nocb: Avoid polling when my_rdp->nocb_head_rdp list is empty rcu/nocb: Add option to opt rcuo kthreads out of RT priority rcu: Add nocb_cb_kthread check to rcu_is_callbacks_kthread() rcu/nocb: Add an option to offload all CPUs on boot rcu/nocb: Fix NOCB kthreads spawn failure with rcu_nocb_rdp_deoffload() direct call rcu/nocb: Invert rcu_state.barrier_mutex VS hotplug lock locking order rcu/nocb: Add/del rdp to iterate from rcuog itself rcu/tree: Add comment to describe GP-done condition in fqs loop rcu: Initialize first_gp_fqs at declaration in rcu_gp_fqs() rcu/kvfree: Remove useless monitor_todo flag rcu: Cleanup RCU urgency state for offline CPU ...
| * | context_tracking: Take idle eqs entrypoints over RCUFrederic Weisbecker2022-07-051-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The RCU dynticks counter is going to be merged into the context tracking subsystem. Start with moving the idle extended quiescent states entrypoints to context tracking. For now those are dumb redirections to existing RCU calls. [ paulmck: Apply kernel test robot feedback. ] Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Neeraj Upadhyay <quic_neeraju@quicinc.com> Cc: Uladzislau Rezki <uladzislau.rezki@sony.com> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Nicolas Saenz Julienne <nsaenz@kernel.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Xiongfeng Wang <wangxiongfeng2@huawei.com> Cc: Yu Liao <liaoyu15@huawei.com> Cc: Phil Auld <pauld@redhat.com> Cc: Paul Gortmaker<paul.gortmaker@windriver.com> Cc: Alex Belits <abelits@marvell.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Reviewed-by: Nicolas Saenz Julienne <nsaenzju@redhat.com> Tested-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
| * | context_tracking: Split user tracking KconfigFrederic Weisbecker2022-06-291-11/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Context tracking is going to be used not only to track user transitions but also idle/IRQs/NMIs. The user tracking part will then become a separate feature. Prepare Kconfig for that. [ frederic: Apply Max Filippov feedback. ] Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Neeraj Upadhyay <quic_neeraju@quicinc.com> Cc: Uladzislau Rezki <uladzislau.rezki@sony.com> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Nicolas Saenz Julienne <nsaenz@kernel.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Xiongfeng Wang <wangxiongfeng2@huawei.com> Cc: Yu Liao <liaoyu15@huawei.com> Cc: Phil Auld <pauld@redhat.com> Cc: Paul Gortmaker<paul.gortmaker@windriver.com> Cc: Alex Belits <abelits@marvell.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Reviewed-by: Nicolas Saenz Julienne <nsaenzju@redhat.com> Tested-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
| * | context_tracking: Rename context_tracking_cpu_set() to ct_cpu_track_user()Frederic Weisbecker2022-06-291-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | context_tracking_cpu_set() is called in order to tell a CPU to track user/kernel transitions. Since context tracking is going to expand in to also track transitions from/to idle/IRQ/NMIs, the scope of this function name becomes too broad and needs to be made more specific. Also shorten the prefix to align with the new namespace. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Neeraj Upadhyay <quic_neeraju@quicinc.com> Cc: Uladzislau Rezki <uladzislau.rezki@sony.com> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Nicolas Saenz Julienne <nsaenz@kernel.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Xiongfeng Wang <wangxiongfeng2@huawei.com> Cc: Yu Liao <liaoyu15@huawei.com> Cc: Phil Auld <pauld@redhat.com> Cc: Paul Gortmaker<paul.gortmaker@windriver.com> Cc: Alex Belits <abelits@marvell.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Reviewed-by: Nicolas Saenz Julienne <nsaenzju@redhat.com> Tested-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
* | | timekeeping: contribute wall clock to rng on time changeJason A. Donenfeld2022-07-181-1/+6
| |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The rng's random_init() function contributes the real time to the rng at boot time, so that events can at least start in relation to something particular in the real world. But this clock might not yet be set that point in boot, so nothing is contributed. In addition, the relation between minor clock changes from, say, NTP, and the cycle counter is potentially useful entropic data. This commit addresses this by mixing in a time stamp on calls to settimeofday and adjtimex. No entropy is credited in doing so, so it doesn't make initialization faster, but it is still useful input to have. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
* | fix race between exit_itimers() and /proc/pid/timersOleg Nesterov2022-07-111-5/+14
| | | | | | | | | | | | | | | | | | | | | | As Chris explains, the comment above exit_itimers() is not correct, we can race with proc_timers_seq_ops. Change exit_itimers() to clear signal->posix_timers with ->siglock held. Cc: <stable@vger.kernel.org> Reported-by: chris@accessvector.net Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | tick/nohz: unexport __init-annotated tick_nohz_full_setup()Masahiro Yamada2022-06-271-1/+0
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | EXPORT_SYMBOL and __init is a bad combination because the .init.text section is freed up after the initialization. Hence, modules cannot use symbols annotated __init. The access to a freed symbol may end up with kernel panic. modpost used to detect it, but it had been broken for a decade. Commit 28438794aba4 ("modpost: fix section mismatch check for exported init/exit sections") fixed it so modpost started to warn it again, then this showed up: MODPOST vmlinux.symvers WARNING: modpost: vmlinux.o(___ksymtab_gpl+tick_nohz_full_setup+0x0): Section mismatch in reference from the variable __ksymtab_tick_nohz_full_setup to the function .init.text:tick_nohz_full_setup() The symbol tick_nohz_full_setup is exported and annotated __init Fix this by removing the __init annotation of tick_nohz_full_setup or drop the export. Drop the export because tick_nohz_full_setup() is only called from the built-in code in kernel/sched/isolation.c. Fixes: ae9e557b5be2 ("time: Export tick start/stop functions for rcutorture") Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Tested-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge tag 'ptrace_stop-cleanup-for-v5.19' of ↵Linus Torvalds2022-06-031-3/+3
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull ptrace_stop cleanups from Eric Biederman: "While looking at the ptrace problems with PREEMPT_RT and the problems Peter Zijlstra was encountering with ptrace in his freezer rewrite I identified some cleanups to ptrace_stop that make sense on their own and move make resolving the other problems much simpler. The biggest issue is the habit of the ptrace code to change task->__state from the tracer to suppress TASK_WAKEKILL from waking up the tracee. No other code in the kernel does that and it is straight forward to update signal_wake_up and friends to make that unnecessary. Peter's task freezer sets frozen tasks to a new state TASK_FROZEN and then it stores them by calling "wake_up_state(t, TASK_FROZEN)" relying on the fact that all stopped states except the special stop states can tolerate spurious wake up and recover their state. The state of stopped and traced tasked is changed to be stored in task->jobctl as well as in task->__state. This makes it possible for the freezer to recover tasks in these special states, as well as serving as a general cleanup. With a little more work in that direction I believe TASK_STOPPED can learn to tolerate spurious wake ups and become an ordinary stop state. The TASK_TRACED state has to remain a special state as the registers for a process are only reliably available when the process is stopped in the scheduler. Fundamentally ptrace needs acess to the saved register values of a task. There are bunch of semi-random ptrace related cleanups that were found while looking at these issues. One cleanup that deserves to be called out is from commit 57b6de08b5f6 ("ptrace: Admit ptrace_stop can generate spuriuos SIGTRAPs"). This makes a change that is technically user space visible, in the handling of what happens to a tracee when a tracer dies unexpectedly. According to our testing and our understanding of userspace nothing cares that spurious SIGTRAPs can be generated in that case" * tag 'ptrace_stop-cleanup-for-v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: sched,signal,ptrace: Rework TASK_TRACED, TASK_STOPPED state ptrace: Always take siglock in ptrace_resume ptrace: Don't change __state ptrace: Admit ptrace_stop can generate spuriuos SIGTRAPs ptrace: Document that wait_task_inactive can't fail ptrace: Reimplement PTRACE_KILL by always sending SIGKILL signal: Use lockdep_assert_held instead of assert_spin_locked ptrace: Remove arch_ptrace_attach ptrace/xtensa: Replace PT_SINGLESTEP with TIF_SINGLESTEP ptrace/um: Replace PT_DTRACE with TIF_SINGLESTEP signal: Replace __group_send_sig_info with send_signal_locked signal: Rename send_signal send_signal_locked
| * signal: Replace __group_send_sig_info with send_signal_lockedEric W. Biederman2022-05-111-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | The function __group_send_sig_info is just a light wrapper around send_signal_locked with one parameter fixed to a constant value. As the wrapper adds no real value update the code to directly call the wrapped function. Tested-by: Kees Cook <keescook@chromium.org> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Link: https://lkml.kernel.org/r/20220505182645.497868-2-ebiederm@xmission.com Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
* | Merge tag 'random-5.19-rc1-for-linus' of ↵Linus Torvalds2022-05-242-2/+15
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/crng/random Pull random number generator updates from Jason Donenfeld: "These updates continue to refine the work began in 5.17 and 5.18 of modernizing the RNG's crypto and streamlining and documenting its code. New for 5.19, the updates aim to improve entropy collection methods and make some initial decisions regarding the "premature next" problem and our threat model. The cloc utility now reports that random.c is 931 lines of code and 466 lines of comments, not that basic metrics like that mean all that much, but at the very least it tells you that this is very much a manageable driver now. Here's a summary of the various updates: - The random_get_entropy() function now always returns something at least minimally useful. This is the primary entropy source in most collectors, which in the best case expands to something like RDTSC, but prior to this change, in the worst case it would just return 0, contributing nothing. For 5.19, additional architectures are wired up, and architectures that are entirely missing a cycle counter now have a generic fallback path, which uses the highest resolution clock available from the timekeeping subsystem. Some of those clocks can actually be quite good, despite the CPU not having a cycle counter of its own, and going off-core for a stamp is generally thought to increase jitter, something positive from the perspective of entropy gathering. Done very early on in the development cycle, this has been sitting in next getting some testing for a while now and has relevant acks from the archs, so it should be pretty well tested and fine, but is nonetheless the thing I'll be keeping my eye on most closely. - Of particular note with the random_get_entropy() improvements is MIPS, which, on CPUs that lack the c0 count register, will now combine the high-speed but short-cycle c0 random register with the lower-speed but long-cycle generic fallback path. - With random_get_entropy() now always returning something useful, the interrupt handler now collects entropy in a consistent construction. - Rather than comparing two samples of random_get_entropy() for the jitter dance, the algorithm now tests many samples, and uses the amount of differing ones to determine whether or not jitter entropy is usable and how laborious it must be. The problem with comparing only two samples was that if the cycle counter was extremely slow, but just so happened to be on the cusp of a change, the slowness wouldn't be detected. Taking many samples fixes that to some degree. This, combined with the other improvements to random_get_entropy(), should make future unification of /dev/random and /dev/urandom maybe more possible. At the very least, were we to attempt it again today (we're not), it wouldn't break any of Guenter's test rigs that broke when we tried it with 5.18. So, not today, but perhaps down the road, that's something we can revisit. - We attempt to reseed the RNG immediately upon waking up from system suspend or hibernation, making use of the various timestamps about suspend time and such available, as well as the usual inputs such as RDRAND when available. - Batched randomness now falls back to ordinary randomness before the RNG is initialized. This provides more consistent guarantees to the types of random numbers being returned by the various accessors. - The "pre-init injection" code is now gone for good. I suspect you in particular will be happy to read that, as I recall you expressing your distaste for it a few months ago. Instead, to avoid a "premature first" issue, while still allowing for maximal amount of entropy availability during system boot, the first 128 bits of estimated entropy are used immediately as it arrives, with the next 128 bits being buffered. And, as before, after the RNG has been fully initialized, it winds up reseeding anyway a few seconds later in most cases. This resulted in a pretty big simplification of the initialization code and let us remove various ad-hoc mechanisms like the ugly crng_pre_init_inject(). - The RNG no longer pretends to handle the "premature next" security model, something that various academics and other RNG designs have tried to care about in the past. After an interesting mailing list thread, these issues are thought to be a) mainly academic and not practical at all, and b) actively harming the real security of the RNG by delaying new entropy additions after a potential compromise, making a potentially bad situation even worse. As well, in the first place, our RNG never even properly handled the premature next issue, so removing an incomplete solution to a fake problem was particularly nice. This allowed for numerous other simplifications in the code, which is a lot cleaner as a consequence. If you didn't see it before, https://lore.kernel.org/lkml/YmlMGx6+uigkGiZ0@zx2c4.com/ may be a thread worth skimming through. - While the interrupt handler received a separate code path years ago that avoids locks by using per-cpu data structures and a faster mixing algorithm, in order to reduce interrupt latency, input and disk events that are triggered in hardirq handlers were still hitting locks and more expensive algorithms. Those are now redirected to use the faster per-cpu data structures. - Rather than having the fake-crypto almost-siphash-based random32 implementation be used right and left, and in many places where cryptographically secure randomness is desirable, the batched entropy code is now fast enough to replace that. - As usual, numerous code quality and documentation cleanups. For example, the initialization state machine now uses enum symbolic constants instead of just hard coding numbers everywhere. - Since the RNG initializes once, and then is always initialized thereafter, a pretty heavy amount of code used during that initialization is never used again. It is now completely cordoned off using static branches and it winds up in the .text.unlikely section so that it doesn't reduce cache compactness after the RNG is ready. - A variety of functions meant for waiting on the RNG to be initialized were only used by vsprintf, and in not a particularly optimal way. Replacing that usage with a more ordinary setup made it possible to remove those functions. - A cleanup of how we warn userspace about the use of uninitialized /dev/urandom and uninitialized get_random_bytes() usage. Interestingly, with the change you merged for 5.18 that attempts to use jitter (but does not block if it can't), the majority of users should never see those warnings for /dev/urandom at all now, and the one for in-kernel usage is mainly a debug thing. - The file_operations struct for /dev/[u]random now implements .read_iter and .write_iter instead of .read and .write, allowing it to also implement .splice_read and .splice_write, which makes splice(2) work again after it was broken here (and in many other places in the tree) during the set_fs() removal. This was a bit of a last minute arrival from Jens that hasn't had as much time to bake, so I'll be keeping my eye on this as well, but it seems fairly ordinary. Unfortunately, read_iter() is around 3% slower than read() in my tests, which I'm not thrilled about. But Jens and Al, spurred by this observation, seem to be making progress in removing the bottlenecks on the iter paths in the VFS layer in general, which should remove the performance gap for all drivers. - Assorted other bug fixes, cleanups, and optimizations. - A small SipHash cleanup" * tag 'random-5.19-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random: (49 commits) random: check for signals after page of pool writes random: wire up fops->splice_{read,write}_iter() random: convert to using fops->write_iter() random: convert to using fops->read_iter() random: unify batched entropy implementations random: move randomize_page() into mm where it belongs random: remove mostly unused async readiness notifier random: remove get_random_bytes_arch() and add rng_has_arch_random() random: move initialization functions out of hot pages random: make consistent use of buf and len random: use proper return types on get_random_{int,long}_wait() random: remove extern from functions in header random: use static branch for crng_ready() random: credit architectural init the exact amount random: handle latent entropy and command line from random_init() random: use proper jiffies comparison macro random: remove ratelimiting for in-kernel unseeded randomness random: move initialization out of reseeding hot path random: avoid initializing twice in credit race random: use symbolic constants for crng_init states ...
| * | random32: use real rng for non-deterministic randomnessJason A. Donenfeld2022-05-181-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | random32.c has two random number generators in it: one that is meant to be used deterministically, with some predefined seed, and one that does the same exact thing as random.c, except does it poorly. The first one has some use cases. The second one no longer does and can be replaced with calls to random.c's proper random number generator. The relatively recent siphash-based bad random32.c code was added in response to concerns that the prior random32.c was too deterministic. Out of fears that random.c was (at the time) too slow, this code was anonymously contributed. Then out of that emerged a kind of shadow entropy gathering system, with its own tentacles throughout various net code, added willy nilly. Stop👏making👏bespoke👏random👏number👏generators👏. Fortunately, recent advances in random.c mean that we can stop playing with this sketchiness, and just use get_random_u32(), which is now fast enough. In micro benchmarks using RDPMC, I'm seeing the same median cycle count between the two functions, with the mean being _slightly_ higher due to batches refilling (which we can optimize further need be). However, when doing *real* benchmarks of the net functions that actually use these random numbers, the mean cycles actually *decreased* slightly (with the median still staying the same), likely because the additional prandom code means icache misses and complexity, whereas random.c is generally already being used by something else nearby. The biggest benefit of this is that there are many users of prandom who probably should be using cryptographically secure random numbers. This makes all of those accidental cases become secure by just flipping a switch. Later on, we can do a tree-wide cleanup to remove the static inline wrapper functions that this commit adds. There are also some low-ish hanging fruits for making this even faster in the future: a get_random_u16() function for use in the networking stack will give a 2x performance boost there, using SIMD for ChaCha20 will let us compute 4 or 8 or 16 blocks of output in parallel, instead of just one, giving us large buffers for cheap, and introducing a get_random_*_bh() function that assumes irqs are already disabled will shave off a few cycles for ordinary calls. These are things we can chip away at down the road. Acked-by: Jakub Kicinski <kuba@kernel.org> Acked-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
| * | timekeeping: Add raw clock fallback for random_get_entropy()Jason A. Donenfeld2022-05-131-0/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The addition of random_get_entropy_fallback() provides access to whichever time source has the highest frequency, which is useful for gathering entropy on platforms without available cycle counters. It's not necessarily as good as being able to quickly access a cycle counter that the CPU has, but it's still something, even when it falls back to being jiffies-based. In the event that a given arch does not define get_cycles(), falling back to the get_cycles() default implementation that returns 0 is really not the best we can do. Instead, at least calling random_get_entropy_fallback() would be preferable, because that always needs to return _something_, even falling back to jiffies eventually. It's not as though random_get_entropy_fallback() is super high precision or guaranteed to be entropic, but basically anything that's not zero all the time is better than returning zero all the time. Finally, since random_get_entropy_fallback() is used during extremely early boot when randomizing freelists in mm_init(), it can be called before timekeeping has been initialized. In that case there really is nothing we can do; jiffies hasn't even started ticking yet. So just give up and return 0. Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Theodore Ts'o <tytso@mit.edu>
* | | Merge tag 'timers-core-2022-05-23' of ↵Linus Torvalds2022-05-236-42/+121
|\ \ \ | |/ / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer and timekeeping updates from Thomas Gleixner: - Expose CLOCK_TAI to instrumentation to aid with TSN debugging. - Ensure that the clockevent is stopped when there is no timer armed to avoid pointless wakeups. - Make the sched clock frequency handling and rounding consistent. - Provide a better debugobject hint for delayed works. The timer callback is always the same, which makes it difficult to identify the underlying work. Use the work function as a hint instead. - Move the timer specific sysctl code into the timer subsystem. - The usual set of improvements and cleanups * tag 'timers-core-2022-05-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: timers: Provide a better debugobjects hint for delayed works time/sched_clock: Fix formatting of frequency reporting code time/sched_clock: Use Hz as the unit for clock rate reporting below 4kHz time/sched_clock: Round the frequency reported to nearest rather than down timekeeping: Consolidate fast timekeeper timekeeping: Annotate ktime_get_boot_fast_ns() with data_race() timers/nohz: Switch to ONESHOT_STOPPED in the low-res handler when the tick is stopped timekeeping: Introduce fast accessor to clock tai tracing/timer: Add missing argument documentation of trace points clocksource: Replace cpumask_weight() with cpumask_empty() timers: Move timer sysctl into the timer code clockevents: Use dedicated list iterator variable timers: Simplify calc_index() timers: Initialize base::next_expiry_recalc in timers_prepare_cpu()
| * | timers: Provide a better debugobjects hint for delayed worksStephen Boyd2022-05-141-1/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With debugobjects enabled the timer hint for freeing of active timers embedded inside delayed works is always the same, i.e. the hint is delayed_work_timer_fn, even though the function the delayed work is going to run can be wildly different depending on what work was queued. Enabling workqueue debugobjects doesn't help either because the delayed work isn't considered active until it is actually queued to run on a workqueue. If the work is freed while the timer is pending the work isn't considered active so there is no information from workqueue debugobjects. Special case delayed works in the timer debugobjects hint logic so that the delayed work function is returned instead of the delayed_work_timer_fn. This will help to understand which delayed work was pending that got freed. Apply the same treatment for kthread_delayed_work because it follows the same pattern. Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Stephen Boyd <swboyd@chromium.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20220511201951.42408-1-swboyd@chromium.org
| * | time/sched_clock: Fix formatting of frequency reporting codeMaciej W. Rozycki2022-05-021-6/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use flat rather than nested indentation for chained else/if clauses as per coding-style.rst: if (x == y) { .. } else if (x > y) { ... } else { .... } This also improves readability. Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: John Stultz <jstultz@google.com> Link: https://lore.kernel.org/r/alpine.DEB.2.21.2204240148220.9383@angie.orcam.me.uk
| * | time/sched_clock: Use Hz as the unit for clock rate reporting below 4kHzMaciej W. Rozycki2022-05-021-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The kernel uses kHz as the unit for clock rates reported between 1MHz (inclusive) and 4MHz (exclusive), e.g.: sched_clock: 64 bits at 1000kHz, resolution 1000ns, wraps every 2199023255500ns This reduces the amount of data lost due to rounding, but hasn't been replicated for the kHz range when support was added for proper reporting of sub-kHz clock rates. Take the same approach for rates between 1kHz (inclusive) and 4kHz (exclusive), which makes it consistent. Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/alpine.DEB.2.21.2204240106380.9383@angie.orcam.me.uk
| * | time/sched_clock: Round the frequency reported to nearest rather than downMaciej W. Rozycki2022-05-021-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The frequency reported for clock sources are rounded down, which gives misleading figures, e.g.: I/O ASIC clock frequency 24999480Hz sched_clock: 32 bits at 24MHz, resolution 40ns, wraps every 85901132779ns MIPS counter frequency 59998512Hz sched_clock: 32 bits at 59MHz, resolution 16ns, wraps every 35792281591ns Rounding to nearest is more adequate: I/O ASIC clock frequency 24999664Hz sched_clock: 32 bits at 25MHz, resolution 40ns, wraps every 85900499947ns MIPS counter frequency 59999728Hz sched_clock: 32 bits at 60MHz, resolution 16ns, wraps every 35791556599ns Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: John Stultz <jstultz@google.com> Link: https://lore.kernel.org/r/alpine.DEB.2.21.2204240055590.9383@angie.orcam.me.uk
| * | timekeeping: Consolidate fast timekeeperThomas Gleixner2022-05-021-10/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | Provide a inline function which replaces the copy & pasta. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20220415091921.072296632@linutronix.de
| * | timekeeping: Annotate ktime_get_boot_fast_ns() with data_race()Thomas Gleixner2022-05-021-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Accessing timekeeper::offset_boot in ktime_get_boot_fast_ns() is an intended data race as the reader side cannot synchronize with a writer and there is no space in struct tk_read_base of the NMI safe timekeeper. Mark it so. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20220415091920.956045162@linutronix.de
| * | timers/nohz: Switch to ONESHOT_STOPPED in the low-res handler when the tick ↵Nicholas Piggin2022-04-251-2/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | is stopped When tick_nohz_stop_tick() stops the tick and high resolution timers are disabled, then the clock event device is not put into ONESHOT_STOPPED mode. This can lead to spurious timer interrupts with some clock event device drivers that don't shut down entirely after firing. Eliminate these by putting the device into ONESHOT_STOPPED mode at points where it is not being reprogrammed. When there are no timers active, then tick_program_event() with KTIME_MAX can be used to stop the device. When there is a timer active, the device can be stopped at the next tick (any new timer added by timers will reprogram the tick). Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20220422141446.915024-1-npiggin@gmail.com
| * | Merge tag 'tai-for-tracing' into timers/coreThomas Gleixner2022-04-141-0/+17
| |\ \ | | | | | | | | | | | | | | | | Pull in the NMI safe TAI accessor which was provided for the tracing tree to prepare for further changes in this area.
| | * | timekeeping: Introduce fast accessor to clock taiKurt Kanzenbach2022-04-141-0/+17
| | |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce fast/NMI safe accessor to clock tai for tracing. The Linux kernel tracing infrastructure has support for using different clocks to generate timestamps for trace events. Especially in TSN networks it's useful to have TAI as trace clock, because the application scheduling is done in accordance to the network time, which is based on TAI. With a tai trace_clock in place, it becomes very convenient to correlate network activity with Linux kernel application traces. Use the same implementation as ktime_get_boot_fast_ns() does by reading the monotonic time and adding the TAI offset. The same limitations as for the fast boot implementation apply. The TAI offset may change at run time e.g., by setting the time or using adjtimex() with an offset. However, these kind of offset changes are rare events. Nevertheless, the user has to be aware and deal with it in post processing. An alternative approach would be to use the same implementation as ktime_get_real_fast_ns() does. However, this requires to add an additional u64 member to the tk_read_base struct. This struct together with a seqcount is designed to fit into a single cache line on 64 bit architectures. Adding a new member would violate this constraint. Signed-off-by: Kurt Kanzenbach <kurt@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Steven Rostedt <rostedt@goodmis.org> Link: https://lore.kernel.org/r/20220414091805.89667-2-kurt@linutronix.de
| * | clocksource: Replace cpumask_weight() with cpumask_empty()Yury Norov2022-04-101-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | clocksource_verify_percpu() calls cpumask_weight() to check if any bit of a given cpumask is set. This can be done more efficiently with cpumask_empty() because cpumask_empty() stops traversing the cpumask as soon as it finds first set bit, while cpumask_weight() counts all bits unconditionally. Signed-off-by: Yury Norov <yury.norov@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20220210224933.379149-24-yury.norov@gmail.com
| * | timers: Move timer sysctl into the timer codetangmeng2022-04-101-15/+38
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is part of the effort to reduce kernel/sysctl.c to only contain the core logic. Signed-off-by: tangmeng <tangmeng@uniontech.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20220215065019.7520-1-tangmeng@uniontech.com
| * | clockevents: Use dedicated list iterator variableJakob Koschel2022-04-101-4/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To move the list iterator variable into the list_for_each_entry_*() macro in the future it should be avoided to use the list iterator variable after the loop body. To *never* use the list iterator variable after the loop it was concluded to use a separate iterator variable. Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ Link: https://lore.kernel.org/r/20220331215707.883957-1-jakobkoschel@gmail.com
| * | timers: Simplify calc_index()Thomas Gleixner2022-04-091-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The level granularity round up of calc_index() does: (x + (1 << n)) >> n which is obviously equivalent to (x >> n) + 1 but compilers can't figure that out despite the fact that the input range is known to not cause an overflow. It's neither intuitive to read. Just write out the obvious. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/87h778j46c.ffs@tglx
| * | timers: Initialize base::next_expiry_recalc in timers_prepare_cpu()Anna-Maria Behnsen2022-04-091-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When base::next_expiry_recalc is not initialized to false during cpu bringup in HOTPLUG_CPU and is accidently true and no timer is queued in the meantime, the loop through the wheel to find __next_timer_interrupt() might be done for nothing. Therefore initialize base::next_expiry_recalc to false in timers_prepare_cpu(). Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/20220405191732.7438-2-anna-maria@linutronix.de
* | | timekeeping: Mark NMI safe time accessors as notraceKurt Kanzenbach2022-04-291-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Mark the CLOCK_MONOTONIC fast time accessors as notrace. These functions are used in tracing to retrieve timestamps, so they should not recurse. Fixes: 4498e7467e9e ("time: Parametrize all tk_fast_mono users") Fixes: f09cb9a1808e ("time: Introduce tk_fast_raw") Reported-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Kurt Kanzenbach <kurt@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20220426175338.3807ca4f@gandalf.local.home/ Link: https://lore.kernel.org/r/20220428062432.61063-1-kurt@linutronix.de
* | | tick/sched: Fix non-kernel-doc commentJiapeng Chong2022-04-101-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fixes the following W=1 kernel build warning: kernel/time/tick-sched.c:1563: warning: This comment starts with '/**', but isn't a kernel-doc comment. Reported-by: Abaci Robot <abaci@linux.alibaba.com> Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20220214084739.63228-1-jiapeng.chong@linux.alibaba.com
* | | tick/nohz: Use WARN_ON_ONCE() to prevent console saturationPaul Gortmaker2022-04-101-1/+1
|/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While running some testing on code that happened to allow the variable tick_nohz_full_running to get set but with no "possible" NOHZ cores to back up that setting, this warning triggered: if (unlikely(tick_do_timer_cpu == TICK_DO_TIMER_NONE)) WARN_ON(tick_nohz_full_running); The console was overwhemled with an endless stream of one WARN per tick per core and there was no way to even see what was going on w/o using a serial console to capture it and then trace it back to this. Change it to WARN_ON_ONCE(). Fixes: 08ae95f4fd3b ("nohz_full: Allow the boot CPU to be nohz_full") Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20211206145950.10927-3-paul.gortmaker@windriver.com
* / timers: Fix warning condition in __run_timers()Anna-Maria Behnsen2022-04-091-4/+7
|/ | | | | | | | | | | | | | | | | | | When the timer base is empty, base::next_expiry is set to base::clk + NEXT_TIMER_MAX_DELTA and base::next_expiry_recalc is false. When no timer is queued until jiffies reaches base::next_expiry value, the warning for not finding any expired timer and base::next_expiry_recalc is false in __run_timers() triggers. To prevent triggering the warning in this valid scenario base::timers_pending needs to be added to the warning condition. Fixes: 31cd0e119d50 ("timers: Recalculate next timer interrupt only when necessary") Reported-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/20220405191732.7438-3-anna-maria@linutronix.de
* Merge tag 'ptrace-cleanups-for-v5.18' of ↵Linus Torvalds2022-03-281-0/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull ptrace cleanups from Eric Biederman: "This set of changes removes tracehook.h, moves modification of all of the ptrace fields inside of siglock to remove races, adds a missing permission check to ptrace.c The removal of tracehook.h is quite significant as it has been a major source of confusion in recent years. Much of that confusion was around task_work and TIF_NOTIFY_SIGNAL (which I have now decoupled making the semantics clearer). For people who don't know tracehook.h is a vestiage of an attempt to implement uprobes like functionality that was never fully merged, and was later superseeded by uprobes when uprobes was merged. For many years now we have been removing what tracehook functionaly a little bit at a time. To the point where anything left in tracehook.h was some weird strange thing that was difficult to understand" * tag 'ptrace-cleanups-for-v5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: ptrace: Remove duplicated include in ptrace.c ptrace: Check PTRACE_O_SUSPEND_SECCOMP permission on PTRACE_SEIZE ptrace: Return the signal to continue with from ptrace_stop ptrace: Move setting/clearing ptrace_message into ptrace_stop tracehook: Remove tracehook.h resume_user_mode: Move to resume_user_mode.h resume_user_mode: Remove #ifdef TIF_NOTIFY_RESUME in set_notify_resume signal: Move set_notify_signal and clear_notify_signal into sched/signal.h task_work: Decouple TIF_NOTIFY_SIGNAL and task_work task_work: Call tracehook_notify_signal from get_signal on all architectures task_work: Introduce task_work_pending task_work: Remove unnecessary include from posix_timers.h ptrace: Remove tracehook_signal_handler ptrace: Remove arch_syscall_{enter,exit}_tracehook ptrace: Create ptrace_report_syscall_{entry,exit} in ptrace.h ptrace/arm: Rename tracehook_report_syscall report_syscall ptrace: Move ptrace_report_syscall into ptrace.h
| * task_work: Remove unnecessary include from posix_timers.hEric W. Biederman2022-03-101-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Break a header file circular dependency by removing the unnecessary include of task_work.h from posix_timers.h. sched.h -> posix-timers.h posix-timers.h -> task_work.h task_work.h -> sched.h Add missing includes of task_work.h to: arch/x86/mm/tlb.c kernel/time/posix-cpu-timers.c Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lkml.kernel.org/r/20220309162454.123006-6-ebiederm@xmission.com Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
* | Merge tag 'prlimit-tasklist_lock-for-v5.18' of ↵Linus Torvalds2022-03-241-3/+9
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull tasklist_lock optimizations from Eric Biederman: "prlimit and getpriority tasklist_lock optimizations The tasklist_lock popped up as a scalability bottleneck on some testing workloads. The readlocks in do_prlimit and set/getpriority are not necessary in all cases. Based on a cycles profile, it looked like ~87% of the time was spent in the kernel, ~42% of which was just trying to get *some* spinlock (queued_spin_lock_slowpath, not necessarily the tasklist_lock). The big offenders (with rough percentages in cycles of the overall trace): - do_wait 11% - setpriority 8% (done previously in commit 7f8ca0edfe07) - kill 8% - do_exit 5% - clone 3% - prlimit64 2% (this patchset) - getrlimit 1% (this patchset) I can't easily test this patchset on the original workload for various reasons. Instead, I used the microbenchmark below to at least verify there was some improvement. This patchset had a 28% speedup (12% from baseline to set/getprio, then another 14% for prlimit). This series used to do the setpriority case, but an almost identical change was merged as commit 7f8ca0edfe07 ("kernel/sys.c: only take tasklist_lock for get/setpriority(PRIO_PGRP)") so that has been dropped from here. One interesting thing is that my libc's getrlimit() was calling prlimit64, so hoisting the read_lock(tasklist_lock) into sys_prlimit64 had no effect - it essentially optimized the older syscalls only. I didn't do that in this patchset, but figured I'd mention it since it was an option from the previous patch's discussion" micobenchmark.c: --------------- int main(int argc, char **argv) { pid_t child; struct rlimit rlim[1]; fork(); fork(); fork(); fork(); fork(); fork(); for (int i = 0; i < 5000; i++) { child = fork(); if (child < 0) exit(1); if (child > 0) { usleep(1000); kill(child, SIGTERM); waitpid(child, NULL, 0); } else { for (;;) { setpriority(PRIO_PROCESS, 0, getpriority(PRIO_PROCESS, 0)); getrlimit(RLIMIT_CPU, rlim); } } } return 0; } Link: https://lore.kernel.org/lkml/20211213220401.1039578-1-brho@google.com/ [v1] Link: https://lore.kernel.org/lkml/20220105212828.197013-1-brho@google.com/ [v2] Link: https://lore.kernel.org/lkml/20220106172041.522167-1-brho@google.com/ [v3] * tag 'prlimit-tasklist_lock-for-v5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: prlimit: do not grab the tasklist_lock prlimit: make do_prlimit() static
| * | prlimit: do not grab the tasklist_lockBarret Rhoden2022-03-081-3/+9
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Unnecessarily grabbing the tasklist_lock can be a scalability bottleneck for workloads that also must grab the tasklist_lock for waiting, killing, and cloning. The tasklist_lock was grabbed to protect tsk->sighand from disappearing (becoming NULL). tsk->signal was already protected by holding a reference to tsk. update_rlimit_cpu() assumed tsk->sighand != NULL. With this commit, it attempts to lock_task_sighand(). However, this means that update_rlimit_cpu() can fail. This only happens when a task is exiting. Note that during exec, sighand may *change*, but it will not be NULL. Prior to this commit, the do_prlimit() ensured that update_rlimit_cpu() would not fail by read locking the tasklist_lock and checking tsk->sighand != NULL. If update_rlimit_cpu() fails, there may be other tasks that are not exiting that share tsk->signal. However, the group_leader is the last task to be released, so if we cannot update_rlimit_cpu(group_leader), then the entire process is exiting. The only other caller of update_rlimit_cpu() is selinux_bprm_committing_creds(). It has tsk == current, so update_rlimit_cpu() cannot fail (current->sighand cannot disappear until current exits). This change resulted in a 14% speedup on a microbenchmark where parents kill and wait on their children, and children getpriority, setpriority, and getrlimit. Signed-off-by: Barret Rhoden <brho@google.com> Link: https://lkml.kernel.org/r/20220106172041.522167-4-brho@google.com Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* | tick/rcu: Stop allowing RCU_SOFTIRQ in idleFrederic Weisbecker2022-03-071-10/+40
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | RCU_SOFTIRQ used to be special in that it could be raised on purpose within the idle path to prevent from stopping the tick. Some code still prevents from unnecessary warnings related to this specific behaviour while entering in dynticks-idle mode. However the nohz layout has changed quite a bit in ten years, and the removal of CONFIG_RCU_FAST_NO_HZ has been the final straw to this safe-conduct. Now the RCU_SOFTIRQ vector is expected to be raised from sane places. A remaining corner case is admitted though when the vector is invoked in fragile hotplug path. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Paul Menzel <pmenzel@molgen.mpg.de>
* | tick/rcu: Remove obsolete rcu_needs_cpu() parametersFrederic Weisbecker2022-03-071-6/+4
| | | | | | | | | | | | | | | | | | | | | | With the removal of CONFIG_RCU_FAST_NO_HZ, the parameters in rcu_needs_cpu() are not necessary anymore. Simply remove them. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Paul Menzel <pmenzel@molgen.mpg.de>
* | tick: Detect and fix jiffies update stallFrederic Weisbecker2022-03-072-0/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On some rare cases, the timekeeper CPU may be delaying its jiffies update duty for a while. Known causes include: * The timekeeper is waiting on stop_machine in a MULTI_STOP_DISABLE_IRQ or MULTI_STOP_RUN state. Disabled interrupts prevent from timekeeping updates while waiting for the target CPU to complete its stop_machine() callback. * The timekeeper vcpu has VMEXIT'ed for a long while due to some overload on the host. Detect and fix these situations with emergency timekeeping catchups. Original-patch-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de>
* | clocksource: Add a Kconfig option for WATCHDOG_MAX_SKEWWaiman Long2022-02-012-1/+16
|/ | | | | | | | | | | A watchdog maximum skew of 100us may still be too small for some systems or archs. It may also be too small when some kernel debug config options are enabled. So add a new Kconfig option CLOCKSOURCE_WATCHDOG_MAX_SKEW_US to allow kernel builders to have more control on the threshold for marking clocksource as unstable. Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
* Merge tag 'bitmap-5.17-rc1' of git://github.com/norov/linuxLinus Torvalds2022-01-231-2/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull bitmap updates from Yury Norov: - introduce for_each_set_bitrange() - use find_first_*_bit() instead of find_next_*_bit() where possible - unify for_each_bit() macros * tag 'bitmap-5.17-rc1' of git://github.com/norov/linux: vsprintf: rework bitmap_list_string lib: bitmap: add performance test for bitmap_print_to_pagebuf bitmap: unify find_bit operations mm/percpu: micro-optimize pcpu_is_populated() Replace for_each_*_bit_from() with for_each_*_bit() where appropriate find: micro-optimize for_each_{set,clear}_bit() include/linux: move for_each_bit() macros from bitops.h to find.h cpumask: replace cpumask_next_* with cpumask_first_* where appropriate tools: sync tools/bitmap with mother linux all: replace find_next{,_zero}_bit with find_first{,_zero}_bit where appropriate cpumask: use find_first_and_bit() lib: add find_first_and_bit() arch: remove GENERIC_FIND_FIRST_BIT entirely include: move find.h from asm_generic to linux bitops: move find_bit_*_le functions from le.h to find.h bitops: protect find_first_{,zero}_bit properly
| * cpumask: replace cpumask_next_* with cpumask_first_* where appropriateYury Norov2022-01-151-2/+2
| | | | | | | | | | | | | | | | | | | | | | cpumask_first() is a more effective analogue of 'next' version if n == -1 (which means start == 0). This patch replaces 'next' with 'first' where things look trivial. There's no cpumask_first_zero() function, so create it. Signed-off-by: Yury Norov <yury.norov@gmail.com> Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
* | Merge tag 'timers-core-2022-01-13' of ↵Linus Torvalds2022-01-131-10/+42
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer updates from Thomas Gleixner: "Updates for the time(r) subsystem: Core: - Make the clocksource watchdog more robust by better validation checks of the measurement. Drivers: - New drivers for MStar and SSD20xd SOCs - The usual cleanups and improvements all over the place" * tag 'timers-core-2022-01-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: dt-bindings: timer: Add Mstar MSC313e timer devicetree bindings documentation clocksource/drivers/msc313e: Add support for ssd20xd-based platforms clocksource/drivers: Add MStar MSC313e timer support clocksource/drivers/pistachio: Fix -Wunused-but-set-variable warning clocksource/drivers/timer-imx-sysctr: Set cpumask to cpu_possible_mask clocksource/drivers/imx-sysctr: Mark two variable with __ro_after_init clocksource/drivers/renesas,ostm: Make RENESAS_OSTM symbol visible clocksource/drivers/renesas-ostm: Add RZ/G2L OSTM support dt-bindings: timer: renesas: ostm: Document Renesas RZ/G2L OSTM clocksource/drivers/exynos_mct: Fix silly typo resulting in checkpatch warning clocksource: Reduce the default clocksource_watchdog() retries to 2 clocksource: Avoid accidental unstable marking of clocksources dt-bindings: timer: tpm-timer: Add imx8ulp compatible string reset: Add of_reset_control_get_optional_exclusive() clocksource/drivers/exynos_mct: Refactor resources allocation dt-bindings: timer: remove rockchip,rk3066-timer compatible string from rockchip,rk-timer.yaml dt-bindings: timer: cadence_ttc: Add power-domains
| * Merge branch 'clocksource' of ↵Thomas Gleixner2022-01-101-10/+42
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into timers/core Pull clocksource watchdog updates from Paul McKenney: - Avoid accidental unstable marking of clocksources by rejecting clocksource measurements where the source of the skew is the delay reading reference clocksource itself. This change avoids many of the current false positives caused by epic cache-thrashing workloads. - Reduce the default clocksource_watchdog() retries to 2, thus offsetting the increased overhead due to #1 above rereading the reference clocksource. Link: https://lore.kernel.org/lkml/20220105001723.GA536708@paulmck-ThinkPad-P17-Gen-1
| | * clocksource: Reduce the default clocksource_watchdog() retries to 2Waiman Long2021-11-301-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With the previous patch, there is an extra watchdog read in each retry. Now the total number of clocksource reads is increased to 4 per iteration. In order to avoid increasing the clock skew check overhead, the default maximum number of retries is reduced from 3 to 2 to maintain the same 12 clocksource reads in the worst case. Suggested-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
| | * clocksource: Avoid accidental unstable marking of clocksourcesWaiman Long2021-11-301-9/+41
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since commit db3a34e17433 ("clocksource: Retry clock read if long delays detected") and commit 2e27e793e280 ("clocksource: Reduce clocksource-skew threshold"), it is found that tsc clocksource fallback to hpet can sometimes happen on both Intel and AMD systems especially when they are running stressful benchmarking workloads. Of the 23 systems tested with a v5.14 kernel, 10 of them have switched to hpet clock source during the test run. The result of falling back to hpet is a drastic reduction of performance when running benchmarks. For example, the fio performance tests can drop up to 70% whereas the iperf3 performance can drop up to 80%. 4 hpet fallbacks happened during bootup. They were: [ 8.749399] clocksource: timekeeping watchdog on CPU13: hpet read-back delay of 263750ns, attempt 4, marking unstable [ 12.044610] clocksource: timekeeping watchdog on CPU19: hpet read-back delay of 186166ns, attempt 4, marking unstable [ 17.336941] clocksource: timekeeping watchdog on CPU28: hpet read-back delay of 182291ns, attempt 4, marking unstable [ 17.518565] clocksource: timekeeping watchdog on CPU34: hpet read-back delay of 252196ns, attempt 4, marking unstable Other fallbacks happen when the systems were running stressful benchmarks. For example: [ 2685.867873] clocksource: timekeeping watchdog on CPU117: hpet read-back delay of 57269ns, attempt 4, marking unstable [46215.471228] clocksource: timekeeping watchdog on CPU8: hpet read-back delay of 61460ns, attempt 4, marking unstable Commit 2e27e793e280 ("clocksource: Reduce clocksource-skew threshold"), changed the skew margin from 100us to 50us. I think this is too small and can easily be exceeded when running some stressful workloads on a thermally stressed system. So it is switched back to 100us. Even a maximum skew margin of 100us may be too small in for some systems when booting up especially if those systems are under thermal stress. To eliminate the case that the large skew is due to the system being too busy slowing down the reading of both the watchdog and the clocksource, an extra consecutive read of watchdog clock is being done to check this. The consecutive watchdog read delay is compared against WATCHDOG_MAX_SKEW/2. If the delay exceeds the limit, we assume that the system is just too busy. A warning will be printed to the console and the clock skew check is skipped for this round. Fixes: db3a34e17433 ("clocksource: Retry clock read if long delays detected") Fixes: 2e27e793e280 ("clocksource: Reduce clocksource-skew threshold") Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
* | | timekeeping: Really make sure wall_to_monotonic isn't positiveYu Liao2021-12-171-2/+1
|/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Even after commit e1d7ba873555 ("time: Always make sure wall_to_monotonic isn't positive") it is still possible to make wall_to_monotonic positive by running the following code: int main(void) { struct timespec time; clock_gettime(CLOCK_MONOTONIC, &time); time.tv_nsec = 0; clock_settime(CLOCK_REALTIME, &time); return 0; } The reason is that the second parameter of timespec64_compare(), ts_delta, may be unnormalized because the delta is calculated with an open coded substraction which causes the comparison of tv_sec to yield the wrong result: wall_to_monotonic = { .tv_sec = -10, .tv_nsec = 900000000 } ts_delta = { .tv_sec = -9, .tv_nsec = -900000000 } That makes timespec64_compare() claim that wall_to_monotonic < ts_delta, but actually the result should be wall_to_monotonic > ts_delta. After normalization, the result of timespec64_compare() is correct because the tv_sec comparison is not longer misleading: wall_to_monotonic = { .tv_sec = -10, .tv_nsec = 900000000 } ts_delta = { .tv_sec = -10, .tv_nsec = 100000000 } Use timespec64_sub() to ensure that ts_delta is normalized, which fixes the issue. Fixes: e1d7ba873555 ("time: Always make sure wall_to_monotonic isn't positive") Signed-off-by: Yu Liao <liaoyu15@huawei.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20211213135727.1656662-1-liaoyu15@huawei.com
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-19 01:21:49 +0000