Changes in 4.9.274 net: ieee802154: fix null deref in parse dev addr HID: hid-sensor-hub: Return error for hid_set_field() failure HID: Add BUS_VIRTUAL to hid_connect logging HID: usbhid: fix info leak in hid_submit_ctrl ARM: OMAP2+: Fix build warning when mmc_omap is not built HID: gt683r: add missing MODULE_DEVICE_TABLE gfs2: Fix use-after-free in gfs2_glock_shrink_scan scsi: target: core: Fix warning on realtime kernels ethernet: myri10ge: Fix missing error code in myri10ge_probe() net: ipconfig: Don't override command-line hostnames or domains rtnetlink: Fix missing error code in rtnl_bridge_notify() net/x25: Return the correct errno code net: Return the correct errno code fib: Return the correct errno code dmaengine: QCOM_HIDMA_MGMT depends on HAS_IOMEM dmaengine: stedma40: add missing iounmap() on error in d40_probe() mm: hwpoison: change PageHWPoison behavior on hugetlb pages batman-adv: Avoid WARN_ON timing related checks net: ipv4: fix memory leak in netlbl_cipsov4_add_std net: rds: fix memory leak in rds_recvmsg udp: fix race between close() and udp_abort() rtnetlink: Fix regression in bridge VLAN configuration netfilter: synproxy: Fix out of bounds when parsing TCP options alx: Fix an error handling path in 'alx_probe()' net: stmmac: dwmac1000: Fix extended MAC address registers definition qlcnic: Fix an error handling path in 'qlcnic_probe()' netxen_nic: Fix an error handling path in 'netxen_nic_probe()' net: cdc_ncm: switch to eth%d interface naming net: usb: fix possible use-after-free in smsc75xx_bind net: ipv4: fix memory leak in ip_mc_add1_src net/af_unix: fix a data-race in unix_dgram_sendmsg / unix_release_sock be2net: Fix an error handling path in 'be_probe()' net: hamradio: fix memory leak in mkiss_close net: cdc_eem: fix tx fixup skb leak net: ethernet: fix potential use-after-free in ec_bhf_remove scsi: core: Put .shost_dev in failure path if host state changes to RUNNING radeon: use memcpy_to/fromio for UVD fw upload can: bcm: fix infoleak in struct bcm_msg_head tracing: Do no increment trace_clock_global() by one PCI: Mark TI C667X to avoid bus reset PCI: Mark some NVIDIA GPUs to avoid bus reset dmaengine: pl330: fix wrong usage of spinlock flags in dma_cyclc net: fec_ptp: add clock rate zero check can: bcm/raw/isotp: use per module netdevice notifier usb: dwc3: core: fix kernel panic when do reboot tracing: Do not stop recording cmdlines when tracing is off tracing: Do not stop recording comms if the trace file is being read x86/fpu: Reset state for all signal restore failures inet: use bigger hash table for IP ID generation i40e: Be much more verbose about what we can and cannot offload ARM: 9081/1: fix gcc-10 thumb2-kernel regression Makefile: Move -Wno-unused-but-set-variable out of GCC only block arm64: perf: Disable PMU while processing counter overflows Revert "PCI: PM: Do not read power state in pci_enable_device_flags()" mac80211: remove warning in ieee80211_get_sband() cfg80211: call cfg80211_leave_ocb when switching away from OCB mac80211: drop multicast fragments ping: Check return value of function 'ping_queue_rcv_skb' inet: annotate date races around sk->sk_txhash net: caif: fix memory leak in ldisc_open net/packet: annotate accesses to po->bind net/packet: annotate accesses to po->ifindex r8152: Avoid memcpy() over-reading of ETH_SS_STATS sh_eth: Avoid memcpy() over-reading of ETH_SS_STATS r8169: Avoid memcpy() over-reading of ETH_SS_STATS net: qed: Fix memcpy() overflow of qed_dcbx_params() net: ll_temac: Avoid ndo_start_xmit returning NETDEV_TX_BUSY nilfs2: fix memory leak in nilfs_sysfs_delete_device_group i2c: robotfuzz-osif: fix control-request directions Linux 4.9.274 Signed-off-by: Greg Kroah-Hartman <gregkh@google.com> Change-Id: I31d1bfc426326657ecc9db939474f25961471552
157 lines
4.1 KiB
C
157 lines
4.1 KiB
C
/*
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* tracing clocks
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*
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* Copyright (C) 2009 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
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*
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* Implements 3 trace clock variants, with differing scalability/precision
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* tradeoffs:
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*
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* - local: CPU-local trace clock
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* - medium: scalable global clock with some jitter
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* - global: globally monotonic, serialized clock
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*
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* Tracer plugins will chose a default from these clocks.
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*/
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#include <linux/spinlock.h>
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#include <linux/irqflags.h>
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#include <linux/hardirq.h>
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#include <linux/module.h>
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#include <linux/percpu.h>
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#include <linux/sched.h>
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#include <linux/ktime.h>
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#include <linux/trace_clock.h>
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/*
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* trace_clock_local(): the simplest and least coherent tracing clock.
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*
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* Useful for tracing that does not cross to other CPUs nor
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* does it go through idle events.
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*/
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u64 notrace trace_clock_local(void)
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{
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u64 clock;
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/*
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* sched_clock() is an architecture implemented, fast, scalable,
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* lockless clock. It is not guaranteed to be coherent across
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* CPUs, nor across CPU idle events.
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*/
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preempt_disable_notrace();
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clock = sched_clock();
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preempt_enable_notrace();
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return clock;
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}
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EXPORT_SYMBOL_GPL(trace_clock_local);
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/*
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* trace_clock(): 'between' trace clock. Not completely serialized,
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* but not completely incorrect when crossing CPUs either.
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*
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* This is based on cpu_clock(), which will allow at most ~1 jiffy of
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* jitter between CPUs. So it's a pretty scalable clock, but there
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* can be offsets in the trace data.
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*/
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u64 notrace trace_clock(void)
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{
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return local_clock();
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}
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EXPORT_SYMBOL_GPL(trace_clock);
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/*
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* trace_jiffy_clock(): Simply use jiffies as a clock counter.
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* Note that this use of jiffies_64 is not completely safe on
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* 32-bit systems. But the window is tiny, and the effect if
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* we are affected is that we will have an obviously bogus
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* timestamp on a trace event - i.e. not life threatening.
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*/
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u64 notrace trace_clock_jiffies(void)
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{
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return jiffies_64_to_clock_t(jiffies_64 - INITIAL_JIFFIES);
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}
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EXPORT_SYMBOL_GPL(trace_clock_jiffies);
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/*
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* trace_clock_global(): special globally coherent trace clock
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*
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* It has higher overhead than the other trace clocks but is still
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* an order of magnitude faster than GTOD derived hardware clocks.
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*
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* Used by plugins that need globally coherent timestamps.
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*/
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/* keep prev_time and lock in the same cacheline. */
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static struct {
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u64 prev_time;
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arch_spinlock_t lock;
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} trace_clock_struct ____cacheline_aligned_in_smp =
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{
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.lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED,
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};
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u64 notrace trace_clock_global(void)
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{
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unsigned long flags;
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int this_cpu;
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u64 now, prev_time;
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local_irq_save(flags);
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this_cpu = raw_smp_processor_id();
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/*
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* The global clock "guarantees" that the events are ordered
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* between CPUs. But if two events on two different CPUS call
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* trace_clock_global at roughly the same time, it really does
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* not matter which one gets the earlier time. Just make sure
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* that the same CPU will always show a monotonic clock.
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*
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* Use a read memory barrier to get the latest written
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* time that was recorded.
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*/
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smp_rmb();
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prev_time = READ_ONCE(trace_clock_struct.prev_time);
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now = sched_clock_cpu(this_cpu);
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/* Make sure that now is always greater than or equal to prev_time */
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if ((s64)(now - prev_time) < 0)
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now = prev_time;
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/*
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* If in an NMI context then dont risk lockups and simply return
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* the current time.
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*/
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if (unlikely(in_nmi()))
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goto out;
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/* Tracing can cause strange recursion, always use a try lock */
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if (arch_spin_trylock(&trace_clock_struct.lock)) {
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/* Reread prev_time in case it was already updated */
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prev_time = READ_ONCE(trace_clock_struct.prev_time);
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if ((s64)(now - prev_time) < 0)
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now = prev_time;
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trace_clock_struct.prev_time = now;
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/* The unlock acts as the wmb for the above rmb */
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arch_spin_unlock(&trace_clock_struct.lock);
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}
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out:
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local_irq_restore(flags);
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return now;
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}
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EXPORT_SYMBOL_GPL(trace_clock_global);
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static atomic64_t trace_counter;
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/*
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* trace_clock_counter(): simply an atomic counter.
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* Use the trace_counter "counter" for cases where you do not care
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* about timings, but are interested in strict ordering.
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*/
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u64 notrace trace_clock_counter(void)
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{
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return atomic64_add_return(1, &trace_counter);
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}
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