mirros/rockchip-kernel
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity
Files
0114e3e52730b76e0976a43ef496d4925eda1893
rockchip-kernel/kernel
History
John Stultz 78c7b55b36 timekeeping: Fix __ktime_get_fast_ns() regression 
commit 58bfea9532 upstream.

In commit 27727df240 ("Avoid taking lock in NMI path with
CONFIG_DEBUG_TIMEKEEPING"), I changed the logic to open-code
the timekeeping_get_ns() function, but I forgot to include
the unit conversion from cycles to nanoseconds, breaking the
function's output, which impacts users like perf.

This results in bogus perf timestamps like:
 swapper     0 [000]   253.427536:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]   254.426573:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]   254.426687:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]   254.426800:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]   254.426905:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]   254.427022:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]   254.427127:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]   254.427239:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]   254.427346:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]   254.427463:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]   255.426572:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])

Instead of more reasonable expected timestamps like:
 swapper     0 [000]    39.953768:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]    40.064839:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]    40.175956:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]    40.287103:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]    40.398217:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]    40.509324:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]    40.620437:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]    40.731546:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]    40.842654:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]    40.953772:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]    41.064881:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])

Add the proper use of timekeeping_delta_to_ns() to convert
the cycle delta to nanoseconds as needed.

Thanks to Brendan and Alexei for finding this quickly after
the v4.8 release. Unfortunately the problematic commit has
landed in some -stable trees so they'll need this fix as
well.

Many apologies for this mistake. I'll be looking to add a
perf-clock sanity test to the kselftest timers tests soon.

Fixes: 27727df240 "timekeeping: Avoid taking lock in NMI path with CONFIG_DEBUG_TIMEKEEPING"
Reported-by: Brendan Gregg <bgregg@netflix.com>
Reported-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Tested-and-reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1475636148-26539-1-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-16 17:36:14 +02:00
..
bpf
bpf, inode: disallow userns mounts
2016-06-24 10:18:17 -07:00
configs
kconfig: tinyconfig: provide whole choice blocks to avoid warnings
2016-09-24 10:07:42 +02:00
debug
debug: prevent entering debug mode on panic/exception.
2015-02-19 12:39:03 -06:00
events
perf/core: Fix pmu::filter_match for SW-led groups
2016-10-07 15:23:41 +02:00
gcov
gcov: add support for GCC 5.1
2015-06-30 19:44:57 -07:00
irq
genirq/msi: Fix broken debug output
2016-09-24 10:07:46 +02:00
livepatch
livepatch: x86: fix relocation computation with kASLR
2015-11-11 17:36:04 +01:00
locking
locking/qspinlock: Fix spin_unlock_wait() some more
2016-07-27 09:47:29 -07:00
power
PM / hibernate: Fix rtree_next_node() to avoid walking off list ends
2016-09-30 10:18:39 +02:00
printk
printk: fix parsing of "brl=" option
2016-10-07 15:23:43 +02:00
rcu
Merge branches 'doc.2015.10.06a', 'percpu-rwsem.2015.10.06a' and 'torture.2015.10.06a' into HEAD
2015-10-07 16:06:25 -07:00
sched
sched/core: Fix a race between try_to_wake_up() and a woken up task
2016-09-24 10:07:42 +02:00
time
timekeeping: Fix __ktime_get_fast_ns() regression
2016-10-16 17:36:14 +02:00
trace
tracing: Move mutex to protect against resetting of seq data
2016-09-30 10:18:38 +02:00
.gitignore
certs: add .gitignore to stop git nagging about x509_certificate_list
2015-10-21 15:18:35 +01:00
acct.c
acct: check FMODE_CAN_WRITE
2015-04-11 22:27:55 -04:00
async.c
…
audit_fsnotify.c
audit: clean simple fsnotify implementation
2015-08-06 16:14:53 -04:00
audit_tree.c
audit: audit_tree_match can be boolean
2015-11-04 08:23:51 -05:00
audit_watch.c
audit: fix exe_file access in audit_exe_compare
2016-09-24 10:07:36 +02:00
audit.c
mm, page_alloc: distinguish between being unable to sleep, unwilling to sleep and avoiding waking kswapd
2015-11-06 17:50:42 -08:00
audit.h
audit: audit_tree_match can be boolean
2015-11-04 08:23:51 -05:00
auditfilter.c
audit: fix comment block whitespace
2015-11-04 08:23:51 -05:00
auditsc.c
audit: fix a double fetch in audit_log_single_execve_arg()
2016-08-20 18:09:22 +02:00
backtracetest.c
…
bounds.c
…
capability.c
kernel: Add noaudit variant of ns_capable()
2016-09-15 08:27:50 +02:00
cgroup_freezer.c
cgroup: fix handling of multi-destination migration from subtree_control enabling
2015-12-03 10:18:21 -05:00
cgroup_pids.c
cgroup_pids: don't account for the root cgroup
2015-12-03 10:18:21 -05:00
cgroup.c
cgroup: set css->id to -1 during init
2016-08-10 11:49:27 +02:00
compat.c
compat: cleanup coding in compat_get_bitmap() and compat_put_bitmap()
2015-06-04 23:57:18 +02:00
configs.c
…
context_tracking.c
context_tracking: avoid irq_save/irq_restore on guest entry and exit
2015-11-10 12:06:23 +01:00
cpu_pm.c
kernel/cpu_pm: fix cpu_cluster_pm_exit comment
2015-09-03 02:42:20 +02:00
cpu.c
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2015-11-03 18:03:50 -08:00
cpuset.c
cpuset: handle race between CPU hotplug and cpuset_hotplug_work
2016-10-07 15:23:40 +02:00
crash_dump.c
…
cred.c
cred: Reject inodes with invalid ids in set_create_file_as()
2016-09-15 08:27:49 +02:00
delayacct.c
…
dma.c
…
elfcore.c
…
exec_domain.c
Remove rest of exec domains.
2015-04-12 21:03:31 +02:00
exit.c
wait/ptrace: assume __WALL if the child is traced
2016-06-07 18:14:35 -07:00
extable.c
kernel/extable.c: remove duplicated include
2015-09-10 13:29:01 -07:00
fork.c
kernel/fork: fix CLONE_CHILD_CLEARTID regression in nscd
2016-10-07 15:23:46 +02:00
freezer.c
…
futex_compat.c
ptrace: use fsuid, fsgid, effective creds for fs access checks
2016-02-25 12:01:16 -08:00
futex.c
futex: Acknowledge a new waiter in counter before plist
2016-05-04 14:48:43 -07:00
groups.c
kernel: conditionally support non-root users, groups and capabilities
2015-04-15 16:35:22 -07:00
hung_task.c
kernel/hung_task.c: change hung_task.c to use for_each_process_thread()
2015-04-15 16:35:22 -07:00
irq_work.c
treewide: Remove old email address
2015-11-23 09:44:58 +01:00
jump_label.c
locking/static_key: Fix concurrent static_key_slow_inc()
2016-07-27 09:47:29 -07:00
kallsyms.c
…
kcmp.c
ptrace: use fsuid, fsgid, effective creds for fs access checks
2016-02-25 12:01:16 -08:00
Kconfig.freezer
…
Kconfig.hz
…
Kconfig.locks
locking/qrwlock: Rename QUEUE_RWLOCK to QUEUED_RWLOCKS
2015-05-12 09:46:00 +02:00
Kconfig.preempt
…
kexec_core.c
kexec: use file name as the output message prefix
2015-11-06 17:50:42 -08:00
kexec_file.c
kexec: fix double-free when failing to relocate the purgatory
2016-09-24 10:07:36 +02:00
kexec_internal.h
kexec: split kexec_file syscall code to kexec_file.c
2015-09-10 13:29:01 -07:00
kexec.c
kexec: use file name as the output message prefix
2015-11-06 17:50:42 -08:00
kmod.c
kmod: don't run async usermode helper as a child of kworker thread
2015-10-23 17:55:10 +09:00
kprobes.c
perf/x86/hw_breakpoints: Disallow kernel breakpoints unless kprobe-safe
2015-08-04 10:16:54 +02:00
ksysfs.c
kexec: split kexec_load syscall from kexec core code
2015-09-10 13:29:01 -07:00
kthread.c
kernel/kthread.c:kthread_create_on_node(): clarify documentation
2015-09-04 16:54:41 -07:00
latencytop.c
…
Makefile
sys_membarrier(): system-wide memory barrier (generic, x86)
2015-09-11 15:21:34 -07:00
membarrier.c
sys_membarrier(): system-wide memory barrier (generic, x86)
2015-09-11 15:21:34 -07:00
memremap.c
devm_memremap: Fix error value when memremap failed
2016-03-03 15:07:08 -08:00
module_signing.c
KEYS: Merge the type-specific data with the payload data
2015-10-21 15:18:36 +01:00
module-internal.h
…
module.c
module: Invalidate signatures on force-loaded modules
2016-08-20 18:09:27 +02:00
notifier.c
Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2015-09-01 08:40:25 -07:00
nsproxy.c
…
padata.c
…
panic.c
printk: do cond_resched() between lines while outputting to consoles
2016-02-17 12:30:57 -08:00
params.c
Merge tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux
2015-11-09 15:53:39 -08:00
pid_namespace.c
…
pid.c
pidns: fix NULL dereference in __task_pid_nr_ns()
2015-11-24 12:03:55 -08:00
profile.c
mm: rename alloc_pages_exact_node() to __alloc_pages_node()
2015-09-08 15:35:28 -07:00
ptrace.c
ptrace: use fsuid, fsgid, effective creds for fs access checks
2016-02-25 12:01:16 -08:00
range.c
…
reboot.c
kexec: split kexec_load syscall from kexec core code
2015-09-10 13:29:01 -07:00
relay.c
kernel/relay.c: use kvfree() in relay_free_page_array()
2015-06-30 19:44:59 -07:00
resource.c
kernel/resource.c: fix muxed resource handling in __request_region()
2016-03-03 15:07:29 -08:00
seccomp.c
seccomp: always propagate NO_NEW_PRIVS on tsync
2016-03-03 15:07:25 -08:00
signal.c
kernel/signal.c: unexport sigsuspend()
2015-11-20 16:17:32 -08:00
smp.c
mm, page_alloc: distinguish between being unable to sleep, unwilling to sleep and avoiding waking kswapd
2015-11-06 17:50:42 -08:00
smpboot.c
stop_machine: Kill smp_hotplug_thread->pre_unpark, introduce stop_machine_unpark()
2015-10-20 10:23:55 +02:00
smpboot.h
…
softirq.c
…
stacktrace.c
…
stop_machine.c
kernel: remove stop_machine() Kconfig dependency
2015-12-12 10:15:34 -08:00
sys_ni.c
mm: mlock: add new mlock system call
2015-11-05 19:34:48 -08:00
sys.c
prctl: take mmap sem for writing to protect against others
2016-02-25 12:01:25 -08:00
sysctl_binary.c
fs/coredump: prevent fsuid=0 dumps into user-controlled directories
2016-04-12 09:08:58 -07:00
sysctl.c
sysctl: handle error writing UINT_MAX to u32 fields
2016-10-07 15:23:46 +02:00
task_work.c
task_work: remove fifo ordering guarantee
2015-09-05 13:46:58 -07:00
taskstats.c
…
test_kprobes.c
…
torture.c
torture: Consolidate cond_resched_rcu_qs() into stutter_wait()
2015-10-06 11:25:01 -07:00
tracepoint.c
tracepoint: Give priority to probes of tracepoints
2015-10-25 21:33:54 -04:00
tsacct.c
…
uid16.c
…
up.c
…
user_namespace.c
capabilities: ambient capabilities
2015-09-04 16:54:41 -07:00
user-return-notifier.c
…
user.c
…
utsname_sysctl.c
…
utsname.c
…
watchdog.c
watchdog: don't run proc_watchdog_update if new value is same as old
2016-04-12 09:08:54 -07:00
workqueue_internal.h
…
workqueue.c
workqueue: fix rebind bound workers warning
2016-05-18 17:06:50 -07:00