<feed xmlns='http://www.w3.org/2005/Atom'>
<title>user/sven/linux.git/kernel/time, branch v4.9.191</title>
<subtitle>Linux Kernel
</subtitle>
<id>https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v4.9.191</id>
<link rel='self' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v4.9.191'/>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/'/>
<updated>2019-08-04T07:33:21Z</updated>
<entry>
<title>timer_list: Guard procfs specific code</title>
<updated>2019-08-04T07:33:21Z</updated>
<author>
<name>Nathan Huckleberry</name>
<email>nhuck@google.com</email>
</author>
<published>2019-06-14T18:16:04Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=8cc6df3db27df8070f44b7ba3e979e71717550b5'/>
<id>urn:sha1:8cc6df3db27df8070f44b7ba3e979e71717550b5</id>
<content type='text'>
[ Upstream commit a9314773a91a1d3b36270085246a6715a326ff00 ]

With CONFIG_PROC_FS=n the following warning is emitted:

kernel/time/timer_list.c:361:36: warning: unused variable
'timer_list_sops' [-Wunused-const-variable]
   static const struct seq_operations timer_list_sops = {

Add #ifdef guard around procfs specific code.

Signed-off-by: Nathan Huckleberry &lt;nhuck@google.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Reviewed-by: Nick Desaulniers &lt;ndesaulniers@google.com&gt;
Cc: john.stultz@linaro.org
Cc: sboyd@kernel.org
Cc: clang-built-linux@googlegroups.com
Link: https://github.com/ClangBuiltLinux/linux/issues/534
Link: https://lkml.kernel.org/r/20190614181604.112297-1-nhuck@google.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>ntp: Limit TAI-UTC offset</title>
<updated>2019-08-04T07:33:21Z</updated>
<author>
<name>Miroslav Lichvar</name>
<email>mlichvar@redhat.com</email>
</author>
<published>2019-06-18T15:47:13Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=5992cebc8371cac5c1e44e64e0f2a8cbb71eb976'/>
<id>urn:sha1:5992cebc8371cac5c1e44e64e0f2a8cbb71eb976</id>
<content type='text'>
[ Upstream commit d897a4ab11dc8a9fda50d2eccc081a96a6385998 ]

Don't allow the TAI-UTC offset of the system clock to be set by adjtimex()
to a value larger than 100000 seconds.

This prevents an overflow in the conversion to int, prevents the CLOCK_TAI
clock from getting too far ahead of the CLOCK_REALTIME clock, and it is
still large enough to allow leap seconds to be inserted at the maximum rate
currently supported by the kernel (once per day) for the next ~270 years,
however unlikely it is that someone can survive a catastrophic event which
slowed down the rotation of the Earth so much.

Reported-by: Weikang shi &lt;swkhack@gmail.com&gt;
Signed-off-by: Miroslav Lichvar &lt;mlichvar@redhat.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: John Stultz &lt;john.stultz@linaro.org&gt;
Cc: Prarit Bhargava &lt;prarit@redhat.com&gt;
Cc: Richard Cochran &lt;richardcochran@gmail.com&gt;
Cc: Stephen Boyd &lt;sboyd@kernel.org&gt;
Link: https://lkml.kernel.org/r/20190618154713.20929-1-mlichvar@redhat.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>ntp: Allow TAI-UTC offset to be set to zero</title>
<updated>2019-06-22T06:17:14Z</updated>
<author>
<name>Miroslav Lichvar</name>
<email>mlichvar@redhat.com</email>
</author>
<published>2019-04-17T08:48:33Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=5ab0886e03e48abe0ea0e8c9aabbd0ca533dafb3'/>
<id>urn:sha1:5ab0886e03e48abe0ea0e8c9aabbd0ca533dafb3</id>
<content type='text'>
[ Upstream commit fdc6bae940ee9eb869e493990540098b8c0fd6ab ]

The ADJ_TAI adjtimex mode sets the TAI-UTC offset of the system clock.
It is typically set by NTP/PTP implementations and it is automatically
updated by the kernel on leap seconds. The initial value is zero (which
applications may interpret as unknown), but this value cannot be set by
adjtimex. This limitation seems to go back to the original "nanokernel"
implementation by David Mills.

Change the ADJ_TAI check to accept zero as a valid TAI-UTC offset in
order to allow setting it back to the initial value.

Fixes: 153b5d054ac2 ("ntp: support for TAI")
Suggested-by: Ondrej Mosnacek &lt;omosnace@redhat.com&gt;
Signed-off-by: Miroslav Lichvar &lt;mlichvar@redhat.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: John Stultz &lt;john.stultz@linaro.org&gt;
Cc: Richard Cochran &lt;richardcochran@gmail.com&gt;
Cc: Prarit Bhargava &lt;prarit@redhat.com&gt;
Link: https://lkml.kernel.org/r/20190417084833.7401-1-mlichvar@redhat.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>timer/debug: Change /proc/timer_stats from 0644 to 0600</title>
<updated>2019-05-10T15:52:11Z</updated>
<author>
<name>Ben Hutchings</name>
<email>ben@decadent.org.uk</email>
</author>
<published>2019-05-07T19:04:04Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=c9257238740ee492574cf686313037be7470e7ec'/>
<id>urn:sha1:c9257238740ee492574cf686313037be7470e7ec</id>
<content type='text'>
The timer_stats facility should filter and translate PIDs if opened
from a non-initial PID namespace, to avoid leaking information about
the wider system.  It should also not show kernel virtual addresses.
Unfortunately it has now been removed upstream (as redundant)
instead of being fixed.

For stable, fix the leak by restricting access to root only.  A
similar change was already made for the /proc/timer_list file.

Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>timekeeping: Use proper seqcount initializer</title>
<updated>2019-02-12T18:44:54Z</updated>
<author>
<name>Bart Van Assche</name>
<email>bvanassche@acm.org</email>
</author>
<published>2018-11-28T23:43:09Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=b6fc5a5108b410d7cb1a160b40845c943427b7d2'/>
<id>urn:sha1:b6fc5a5108b410d7cb1a160b40845c943427b7d2</id>
<content type='text'>
[ Upstream commit ce10a5b3954f2514af726beb78ed8d7350c5e41c ]

tk_core.seq is initialized open coded, but that misses to initialize the
lockdep map when lockdep is enabled. Lockdep splats involving tk_core seq
consequently lack a name and are hard to read.

Use the proper initializer which takes care of the lockdep map
initialization.

[ tglx: Massaged changelog ]

Signed-off-by: Bart Van Assche &lt;bvanassche@acm.org&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: peterz@infradead.org
Cc: tj@kernel.org
Cc: johannes.berg@intel.com
Link: https://lkml.kernel.org/r/20181128234325.110011-12-bvanassche@acm.org
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>timer/debug: Change /proc/timer_list from 0444 to 0400</title>
<updated>2018-12-21T13:11:30Z</updated>
<author>
<name>Ingo Molnar</name>
<email>mingo@kernel.org</email>
</author>
<published>2017-11-13T06:15:41Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=1098aad93c4a05a0165fd008e13be99201a9e621'/>
<id>urn:sha1:1098aad93c4a05a0165fd008e13be99201a9e621</id>
<content type='text'>
[ Upstream commit 8e7df2b5b7f245c9bd11064712db5cb69044a362 ]

While it uses %pK, there's still few reasons to read this file
as non-root.

Suggested-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Acked-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>posix-timers: Sanitize overrun handling</title>
<updated>2018-11-10T15:43:01Z</updated>
<author>
<name>Thomas Gleixner</name>
<email>tglx@linutronix.de</email>
</author>
<published>2018-11-01T20:02:38Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=65cb24de03f1c8e00a4fedf416b80a4e8f8a6ef2'/>
<id>urn:sha1:65cb24de03f1c8e00a4fedf416b80a4e8f8a6ef2</id>
<content type='text'>
[ Upstream commit 78c9c4dfbf8c04883941445a195276bb4bb92c76 ]

The posix timer overrun handling is broken because the forwarding functions
can return a huge number of overruns which does not fit in an int. As a
consequence timer_getoverrun(2) and siginfo::si_overrun can turn into
random number generators.

The k_clock::timer_forward() callbacks return a 64 bit value now. Make
k_itimer::ti_overrun[_last] 64bit as well, so the kernel internal
accounting is correct. 3Remove the temporary (int) casts.

Add a helper function which clamps the overrun value returned to user space
via timer_getoverrun(2) or siginfo::si_overrun limited to a positive value
between 0 and INT_MAX. INT_MAX is an indicator for user space that the
overrun value has been clamped.

Reported-by: Team OWL337 &lt;icytxw@gmail.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Acked-by: John Stultz &lt;john.stultz@linaro.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Michael Kerrisk &lt;mtk.manpages@gmail.com&gt;
Link: https://lkml.kernel.org/r/20180626132705.018623573@linutronix.de
[florian: Make patch apply to v4.9.135]
Signed-off-by: Florian Fainelli &lt;f.fainelli@gmail.com&gt;
Reviewed-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>time: Introduce jiffies64_to_nsecs()</title>
<updated>2018-10-10T06:53:18Z</updated>
<author>
<name>Frederic Weisbecker</name>
<email>fweisbec@gmail.com</email>
</author>
<published>2017-01-31T03:09:17Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=e7038f8eca7d2b62256d3ea9307791ca9b3e4555'/>
<id>urn:sha1:e7038f8eca7d2b62256d3ea9307791ca9b3e4555</id>
<content type='text'>
commit 07e5f5e353aaa61696c8353d87050994a0c4648a upstream.

This will be needed for the cputime_t to nsec conversion.

Signed-off-by: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: Paul Mackerras &lt;paulus@samba.org&gt;
Cc: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: Heiko Carstens &lt;heiko.carstens@de.ibm.com&gt;
Cc: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
Cc: Tony Luck &lt;tony.luck@intel.com&gt;
Cc: Fenghua Yu &lt;fenghua.yu@intel.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Rik van Riel &lt;riel@redhat.com&gt;
Cc: Stanislaw Gruszka &lt;sgruszka@redhat.com&gt;
Cc: Wanpeng Li &lt;wanpeng.li@hotmail.com&gt;
Link: http://lkml.kernel.org/r/1485832191-26889-2-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Signed-off-by: Ivan Delalande &lt;colona@arista.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>alarmtimer: Prevent overflow for relative nanosleep</title>
<updated>2018-10-04T00:01:45Z</updated>
<author>
<name>Thomas Gleixner</name>
<email>tglx@linutronix.de</email>
</author>
<published>2018-07-02T07:34:29Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=747128e772dc2c413763050c52c55edcacf7f60c'/>
<id>urn:sha1:747128e772dc2c413763050c52c55edcacf7f60c</id>
<content type='text'>
[ Upstream commit 5f936e19cc0ef97dbe3a56e9498922ad5ba1edef ]

Air Icy reported:

  UBSAN: Undefined behaviour in kernel/time/alarmtimer.c:811:7
  signed integer overflow:
  1529859276030040771 + 9223372036854775807 cannot be represented in type 'long long int'
  Call Trace:
   alarm_timer_nsleep+0x44c/0x510 kernel/time/alarmtimer.c:811
   __do_sys_clock_nanosleep kernel/time/posix-timers.c:1235 [inline]
   __se_sys_clock_nanosleep kernel/time/posix-timers.c:1213 [inline]
   __x64_sys_clock_nanosleep+0x326/0x4e0 kernel/time/posix-timers.c:1213
   do_syscall_64+0xb8/0x3a0 arch/x86/entry/common.c:290

alarm_timer_nsleep() uses ktime_add() to add the current time and the
relative expiry value. ktime_add() has no sanity checks so the addition
can overflow when the relative timeout is large enough.

Use ktime_add_safe() which has the necessary sanity checks in place and
limits the result to the valid range.

Fixes: 9a7adcf5c6de ("timers: Posix interface for alarm-timers")
Reported-by: Team OWL337 &lt;icytxw@gmail.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: John Stultz &lt;john.stultz@linaro.org&gt;
Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1807020926360.1595@nanos.tec.linutronix.de
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>timers: Clear timer_base::must_forward_clk with timer_base::lock held</title>
<updated>2018-09-19T20:47:13Z</updated>
<author>
<name>Gaurav Kohli</name>
<email>gkohli@codeaurora.org</email>
</author>
<published>2018-08-02T08:51:03Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=05cb385f95f39151b47baa8cf8d486cba05354f5'/>
<id>urn:sha1:05cb385f95f39151b47baa8cf8d486cba05354f5</id>
<content type='text'>
[ Upstream commit 363e934d8811d799c88faffc5bfca782fd728334 ]

timer_base::must_forward_clock is indicating that the base clock might be
stale due to a long idle sleep.

The forwarding of the base clock takes place in the timer softirq or when a
timer is enqueued to a base which is idle. If the enqueue of timer to an
idle base happens from a remote CPU, then the following race can happen:

  CPU0					CPU1
  run_timer_softirq			mod_timer

					base = lock_timer_base(timer);
  base-&gt;must_forward_clk = false
					if (base-&gt;must_forward_clk)
				       	    forward(base); -&gt; skipped

					enqueue_timer(base, timer, idx);
					-&gt; idx is calculated high due to
					   stale base
					unlock_timer_base(timer);
  base = lock_timer_base(timer);
  forward(base);

The root cause is that timer_base::must_forward_clk is cleared outside the
timer_base::lock held region, so the remote queuing CPU observes it as
cleared, but the base clock is still stale. This can cause large
granularity values for timers, i.e. the accuracy of the expiry time
suffers.

Prevent this by clearing the flag with timer_base::lock held, so that the
forwarding takes place before the cleared flag is observable by a remote
CPU.

Signed-off-by: Gaurav Kohli &lt;gkohli@codeaurora.org&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: john.stultz@linaro.org
Cc: sboyd@kernel.org
Cc: linux-arm-msm@vger.kernel.org
Link: https://lkml.kernel.org/r/1533199863-22748-1-git-send-email-gkohli@codeaurora.org
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
</feed>
