<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/kernel, branch v5.1-rc6</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2019-04-20T17:10:49+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2019-04-20T17:10:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=e899cc3b3d9813f795c039c0f3c689861d6836da'/>
<id>e899cc3b3d9813f795c039c0f3c689861d6836da</id>
<content type='text'>
Pull timer fixes from Ingo Molnar:
 "Misc clocksource driver fixes, and a sched-clock wrapping fix"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  timers/sched_clock: Prevent generic sched_clock wrap caused by tick_freeze()
  clocksource/drivers/timer-ti-dm: Remove omap_dm_timer_set_load_start
  clocksource/drivers/oxnas: Fix OX820 compatible
  clocksource/drivers/arm_arch_timer: Remove unneeded pr_fmt macro
  clocksource/drivers/npcm: select TIMER_OF
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull timer fixes from Ingo Molnar:
 "Misc clocksource driver fixes, and a sched-clock wrapping fix"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  timers/sched_clock: Prevent generic sched_clock wrap caused by tick_freeze()
  clocksource/drivers/timer-ti-dm: Remove omap_dm_timer_set_load_start
  clocksource/drivers/oxnas: Fix OX820 compatible
  clocksource/drivers/arm_arch_timer: Remove unneeded pr_fmt macro
  clocksource/drivers/npcm: select TIMER_OF
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2019-04-20T17:05:02+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2019-04-20T17:05:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=b25c69b9d5e41159b54ad7cb33f7d9ead8523d33'/>
<id>b25c69b9d5e41159b54ad7cb33f7d9ead8523d33</id>
<content type='text'>
Pull perf fixes from Ingo Molnar:
 "Misc fixes:
   - various tooling fixes
   - kretprobe fixes
   - kprobes annotation fixes
   - kprobes error checking fix
   - fix the default events for AMD Family 17h CPUs
   - PEBS fix
   - AUX record fix
   - address filtering fix"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/kprobes: Avoid kretprobe recursion bug
  kprobes: Mark ftrace mcount handler functions nokprobe
  x86/kprobes: Verify stack frame on kretprobe
  perf/x86/amd: Add event map for AMD Family 17h
  perf bpf: Return NULL when RB tree lookup fails in perf_env__find_btf()
  perf tools: Fix map reference counting
  perf evlist: Fix side band thread draining
  perf tools: Check maps for bpf programs
  perf bpf: Return NULL when RB tree lookup fails in perf_env__find_bpf_prog_info()
  tools include uapi: Sync sound/asound.h copy
  perf top: Always sample time to satisfy needs of use of ordered queuing
  perf evsel: Use hweight64() instead of hweight_long(attr.sample_regs_user)
  tools lib traceevent: Fix missing equality check for strcmp
  perf stat: Disable DIR_FORMAT feature for 'perf stat record'
  perf scripts python: export-to-sqlite.py: Fix use of parent_id in calls_view
  perf header: Fix lock/unlock imbalances when processing BPF/BTF info
  perf/x86: Fix incorrect PEBS_REGS
  perf/ring_buffer: Fix AUX record suppression
  perf/core: Fix the address filtering fix
  kprobes: Fix error check when reusing optimized probes
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull perf fixes from Ingo Molnar:
 "Misc fixes:
   - various tooling fixes
   - kretprobe fixes
   - kprobes annotation fixes
   - kprobes error checking fix
   - fix the default events for AMD Family 17h CPUs
   - PEBS fix
   - AUX record fix
   - address filtering fix"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/kprobes: Avoid kretprobe recursion bug
  kprobes: Mark ftrace mcount handler functions nokprobe
  x86/kprobes: Verify stack frame on kretprobe
  perf/x86/amd: Add event map for AMD Family 17h
  perf bpf: Return NULL when RB tree lookup fails in perf_env__find_btf()
  perf tools: Fix map reference counting
  perf evlist: Fix side band thread draining
  perf tools: Check maps for bpf programs
  perf bpf: Return NULL when RB tree lookup fails in perf_env__find_bpf_prog_info()
  tools include uapi: Sync sound/asound.h copy
  perf top: Always sample time to satisfy needs of use of ordered queuing
  perf evsel: Use hweight64() instead of hweight_long(attr.sample_regs_user)
  tools lib traceevent: Fix missing equality check for strcmp
  perf stat: Disable DIR_FORMAT feature for 'perf stat record'
  perf scripts python: export-to-sqlite.py: Fix use of parent_id in calls_view
  perf header: Fix lock/unlock imbalances when processing BPF/BTF info
  perf/x86: Fix incorrect PEBS_REGS
  perf/ring_buffer: Fix AUX record suppression
  perf/core: Fix the address filtering fix
  kprobes: Fix error check when reusing optimized probes
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2019-04-20T16:53:36+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2019-04-20T16:53:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=2b4cf5850db6acef2bbef52e3011f9bf93484209'/>
<id>2b4cf5850db6acef2bbef52e3011f9bf93484209</id>
<content type='text'>
Pull scheduler fixes from Ingo Molnar:
 "A deadline scheduler warning/race fix, and a cfs_period_us quota
  calculation workaround where the real fix looks too involved to merge
  immediately"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/deadline: Correctly handle active 0-lag timers
  sched/fair: Limit sched_cfs_period_timer() loop to avoid hard lockup
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull scheduler fixes from Ingo Molnar:
 "A deadline scheduler warning/race fix, and a cfs_period_us quota
  calculation workaround where the real fix looks too involved to merge
  immediately"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/deadline: Correctly handle active 0-lag timers
  sched/fair: Limit sched_cfs_period_timer() loop to avoid hard lockup
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2019-04-20T16:38:01+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2019-04-20T16:38:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=de3af9a99013fdb0358bb990e9bed0172c65bba9'/>
<id>de3af9a99013fdb0358bb990e9bed0172c65bba9</id>
<content type='text'>
Pull locking fixes from Ingo Molnar:
 "A lockdep warning fix and a script execution fix when atomics are
  generated"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/atomics: Don't assume that scripts are executable
  locking/lockdep: Make lockdep_unregister_key() honor 'debug_locks' again
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull locking fixes from Ingo Molnar:
 "A lockdep warning fix and a script execution fix when atomics are
  generated"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/atomics: Don't assume that scripts are executable
  locking/lockdep: Make lockdep_unregister_key() honor 'debug_locks' again
</pre>
</div>
</content>
</entry>
<entry>
<title>kernel/watchdog_hld.c: hard lockup message should end with a newline</title>
<updated>2019-04-19T16:46:05+00:00</updated>
<author>
<name>Sergey Senozhatsky</name>
<email>sergey.senozhatsky.work@gmail.com</email>
</author>
<published>2019-04-19T00:50:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=8f4a8c12cafe54535f334a09be7ec7f236134764'/>
<id>8f4a8c12cafe54535f334a09be7ec7f236134764</id>
<content type='text'>
Separate print_modules() and hard lockup error message.

Before the patch:

  NMI watchdog: Watchdog detected hard LOCKUP on cpu 1Modules linked in: nls_cp437

Link: http://lkml.kernel.org/r/20190412062557.2700-1-sergey.senozhatsky@gmail.com
Signed-off-by: Sergey Senozhatsky &lt;sergey.senozhatsky@gmail.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Separate print_modules() and hard lockup error message.

Before the patch:

  NMI watchdog: Watchdog detected hard LOCKUP on cpu 1Modules linked in: nls_cp437

Link: http://lkml.kernel.org/r/20190412062557.2700-1-sergey.senozhatsky@gmail.com
Signed-off-by: Sergey Senozhatsky &lt;sergey.senozhatsky@gmail.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>kprobes: Mark ftrace mcount handler functions nokprobe</title>
<updated>2019-04-19T12:26:06+00:00</updated>
<author>
<name>Masami Hiramatsu</name>
<email>mhiramat@kernel.org</email>
</author>
<published>2019-02-23T16:50:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=fabe38ab6b2bd9418350284c63825f13b8a6abba'/>
<id>fabe38ab6b2bd9418350284c63825f13b8a6abba</id>
<content type='text'>
Mark ftrace mcount handler functions nokprobe since
probing on these functions with kretprobe pushes
return address incorrectly on kretprobe shadow stack.

Reported-by: Francis Deslauriers &lt;francis.deslauriers@efficios.com&gt;
Tested-by: Andrea Righi &lt;righi.andrea@gmail.com&gt;
Signed-off-by: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Acked-by: Steven Rostedt &lt;rostedt@goodmis.org&gt;
Acked-by: Steven Rostedt (VMware) &lt;rostedt@goodmis.org&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Mathieu Desnoyers &lt;mathieu.desnoyers@efficios.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/155094062044.6137.6419622920568680640.stgit@devbox
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Mark ftrace mcount handler functions nokprobe since
probing on these functions with kretprobe pushes
return address incorrectly on kretprobe shadow stack.

Reported-by: Francis Deslauriers &lt;francis.deslauriers@efficios.com&gt;
Tested-by: Andrea Righi &lt;righi.andrea@gmail.com&gt;
Signed-off-by: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Acked-by: Steven Rostedt &lt;rostedt@goodmis.org&gt;
Acked-by: Steven Rostedt (VMware) &lt;rostedt@goodmis.org&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Mathieu Desnoyers &lt;mathieu.desnoyers@efficios.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/155094062044.6137.6419622920568680640.stgit@devbox
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>signal: use fdget() since we don't allow O_PATH</title>
<updated>2019-04-18T15:35:18+00:00</updated>
<author>
<name>Christian Brauner</name>
<email>christian@brauner.io</email>
</author>
<published>2019-04-18T10:18:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=738a7832d21e3d911fcddab98ce260b79010b461'/>
<id>738a7832d21e3d911fcddab98ce260b79010b461</id>
<content type='text'>
As stated in the original commit for pidfd_send_signal() we don't allow
to signal processes through O_PATH file descriptors since it is
semantically equivalent to a write on the pidfd.

We already correctly error out right now and return EBADF if an O_PATH
fd is passed.  This is because we use file-&gt;f_op to detect whether a
pidfd is passed and O_PATH fds have their file-&gt;f_op set to empty_fops
in do_dentry_open() and thus fail the test.

Thus, there is no regression.  It's just semantically correct to use
fdget() and return an error right from there instead of taking a
reference and returning an error later.

Signed-off-by: Christian Brauner &lt;christian@brauner.io&gt;
Acked-by: Oleg Nesterov &lt;oleg@redhat.com&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: "Eric W. Biederman" &lt;ebiederm@xmission.com&gt;
Cc: Kees Cook &lt;keescook@chromium.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Jann Horn &lt;jann@thejh.net&gt;
Cc: David Howells &lt;dhowells@redhat.com&gt;
Cc: "Michael Kerrisk (man-pages)" &lt;mtk.manpages@gmail.com&gt;
Cc: Andy Lutomirsky &lt;luto@kernel.org&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Oleg Nesterov &lt;oleg@redhat.com&gt;
Cc: Aleksa Sarai &lt;cyphar@cyphar.com&gt;
Cc: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
As stated in the original commit for pidfd_send_signal() we don't allow
to signal processes through O_PATH file descriptors since it is
semantically equivalent to a write on the pidfd.

We already correctly error out right now and return EBADF if an O_PATH
fd is passed.  This is because we use file-&gt;f_op to detect whether a
pidfd is passed and O_PATH fds have their file-&gt;f_op set to empty_fops
in do_dentry_open() and thus fail the test.

Thus, there is no regression.  It's just semantically correct to use
fdget() and return an error right from there instead of taking a
reference and returning an error later.

Signed-off-by: Christian Brauner &lt;christian@brauner.io&gt;
Acked-by: Oleg Nesterov &lt;oleg@redhat.com&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: "Eric W. Biederman" &lt;ebiederm@xmission.com&gt;
Cc: Kees Cook &lt;keescook@chromium.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Jann Horn &lt;jann@thejh.net&gt;
Cc: David Howells &lt;dhowells@redhat.com&gt;
Cc: "Michael Kerrisk (man-pages)" &lt;mtk.manpages@gmail.com&gt;
Cc: Andy Lutomirsky &lt;luto@kernel.org&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Oleg Nesterov &lt;oleg@redhat.com&gt;
Cc: Aleksa Sarai &lt;cyphar@cyphar.com&gt;
Cc: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>timers/sched_clock: Prevent generic sched_clock wrap caused by tick_freeze()</title>
<updated>2019-04-18T12:34:53+00:00</updated>
<author>
<name>Chang-An Chen</name>
<email>chang-an.chen@mediatek.com</email>
</author>
<published>2019-03-29T02:59:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=3f2552f7e9c5abef2775c53f7af66532f8bf65bc'/>
<id>3f2552f7e9c5abef2775c53f7af66532f8bf65bc</id>
<content type='text'>
tick_freeze() introduced by suspend-to-idle in commit 124cf9117c5f ("PM /
sleep: Make it possible to quiesce timers during suspend-to-idle") uses
timekeeping_suspend() instead of syscore_suspend() during
suspend-to-idle. As a consequence generic sched_clock will keep going
because sched_clock_suspend() and sched_clock_resume() are not invoked
during suspend-to-idle which can result in a generic sched_clock wrap.

On a ARM system with suspend-to-idle enabled, sched_clock is registered
as "56 bits at 13MHz, resolution 76ns, wraps every 4398046511101ns", which
means the real wrapping duration is 8796093022202ns.

[  134.551779] suspend-to-idle suspend (timekeeping_suspend())
[ 1204.912239] suspend-to-idle resume (timekeeping_resume())
......
[ 1206.912239] suspend-to-idle suspend (timekeeping_suspend())
[ 5880.502807] suspend-to-idle resume (timekeeping_resume())
......
[ 6000.403724] suspend-to-idle suspend (timekeeping_suspend())
[ 8035.753167] suspend-to-idle resume  (timekeeping_resume())
......
[ 8795.786684] (2)[321:charger_thread]......
[ 8795.788387] (2)[321:charger_thread]......
[    0.057226] (0)[0:swapper/0]......
[    0.061447] (2)[0:swapper/2]......

sched_clock was not stopped during suspend-to-idle, and sched_clock_poll
hrtimer was not expired because timekeeping_suspend() was invoked during
suspend-to-idle. It makes sched_clock wrap at kernel time 8796s.

To prevent this, invoke sched_clock_suspend() and sched_clock_resume() in
tick_freeze() together with timekeeping_suspend() and timekeeping_resume().

Fixes: 124cf9117c5f (PM / sleep: Make it possible to quiesce timers during suspend-to-idle)
Signed-off-by: Chang-An Chen &lt;chang-an.chen@mediatek.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
Cc: Matthias Brugger &lt;matthias.bgg@gmail.com&gt;
Cc: John Stultz &lt;john.stultz@linaro.org&gt;
Cc: Kees Cook &lt;keescook@chromium.org&gt;
Cc: Corey Minyard &lt;cminyard@mvista.com&gt;
Cc: &lt;linux-mediatek@lists.infradead.org&gt;
Cc: &lt;linux-arm-kernel@lists.infradead.org&gt;
Cc: Stanley Chu &lt;stanley.chu@mediatek.com&gt;
Cc: &lt;kuohong.wang@mediatek.com&gt;
Cc: &lt;freddy.hsin@mediatek.com&gt;
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/1553828349-8914-1-git-send-email-chang-an.chen@mediatek.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
tick_freeze() introduced by suspend-to-idle in commit 124cf9117c5f ("PM /
sleep: Make it possible to quiesce timers during suspend-to-idle") uses
timekeeping_suspend() instead of syscore_suspend() during
suspend-to-idle. As a consequence generic sched_clock will keep going
because sched_clock_suspend() and sched_clock_resume() are not invoked
during suspend-to-idle which can result in a generic sched_clock wrap.

On a ARM system with suspend-to-idle enabled, sched_clock is registered
as "56 bits at 13MHz, resolution 76ns, wraps every 4398046511101ns", which
means the real wrapping duration is 8796093022202ns.

[  134.551779] suspend-to-idle suspend (timekeeping_suspend())
[ 1204.912239] suspend-to-idle resume (timekeeping_resume())
......
[ 1206.912239] suspend-to-idle suspend (timekeeping_suspend())
[ 5880.502807] suspend-to-idle resume (timekeeping_resume())
......
[ 6000.403724] suspend-to-idle suspend (timekeeping_suspend())
[ 8035.753167] suspend-to-idle resume  (timekeeping_resume())
......
[ 8795.786684] (2)[321:charger_thread]......
[ 8795.788387] (2)[321:charger_thread]......
[    0.057226] (0)[0:swapper/0]......
[    0.061447] (2)[0:swapper/2]......

sched_clock was not stopped during suspend-to-idle, and sched_clock_poll
hrtimer was not expired because timekeeping_suspend() was invoked during
suspend-to-idle. It makes sched_clock wrap at kernel time 8796s.

To prevent this, invoke sched_clock_suspend() and sched_clock_resume() in
tick_freeze() together with timekeeping_suspend() and timekeeping_resume().

Fixes: 124cf9117c5f (PM / sleep: Make it possible to quiesce timers during suspend-to-idle)
Signed-off-by: Chang-An Chen &lt;chang-an.chen@mediatek.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
Cc: Matthias Brugger &lt;matthias.bgg@gmail.com&gt;
Cc: John Stultz &lt;john.stultz@linaro.org&gt;
Cc: Kees Cook &lt;keescook@chromium.org&gt;
Cc: Corey Minyard &lt;cminyard@mvista.com&gt;
Cc: &lt;linux-mediatek@lists.infradead.org&gt;
Cc: &lt;linux-arm-kernel@lists.infradead.org&gt;
Cc: Stanley Chu &lt;stanley.chu@mediatek.com&gt;
Cc: &lt;kuohong.wang@mediatek.com&gt;
Cc: &lt;freddy.hsin@mediatek.com&gt;
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/1553828349-8914-1-git-send-email-chang-an.chen@mediatek.com
</pre>
</div>
</content>
</entry>
<entry>
<title>sched/deadline: Correctly handle active 0-lag timers</title>
<updated>2019-04-16T14:54:58+00:00</updated>
<author>
<name>luca abeni</name>
<email>luca.abeni@santannapisa.it</email>
</author>
<published>2019-03-25T13:15:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=1b02cd6a2d7f3e2a6a5262887d2cb2912083e42f'/>
<id>1b02cd6a2d7f3e2a6a5262887d2cb2912083e42f</id>
<content type='text'>
syzbot reported the following warning:

   [ ] WARNING: CPU: 4 PID: 17089 at kernel/sched/deadline.c:255 task_non_contending+0xae0/0x1950

line 255 of deadline.c is:

	WARN_ON(hrtimer_active(&amp;dl_se-&gt;inactive_timer));

in task_non_contending().

Unfortunately, in some cases (for example, a deadline task
continuosly blocking and waking immediately) it can happen that
a task blocks (and task_non_contending() is called) while the
0-lag timer is still active.

In this case, the safest thing to do is to immediately decrease
the running bandwidth of the task, without trying to re-arm the 0-lag timer.

Signed-off-by: luca abeni &lt;luca.abeni@santannapisa.it&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Acked-by: Juri Lelli &lt;juri.lelli@redhat.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: chengjian (D) &lt;cj.chengjian@huawei.com&gt;
Link: https://lkml.kernel.org/r/20190325131530.34706-1-luca.abeni@santannapisa.it
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
syzbot reported the following warning:

   [ ] WARNING: CPU: 4 PID: 17089 at kernel/sched/deadline.c:255 task_non_contending+0xae0/0x1950

line 255 of deadline.c is:

	WARN_ON(hrtimer_active(&amp;dl_se-&gt;inactive_timer));

in task_non_contending().

Unfortunately, in some cases (for example, a deadline task
continuosly blocking and waking immediately) it can happen that
a task blocks (and task_non_contending() is called) while the
0-lag timer is still active.

In this case, the safest thing to do is to immediately decrease
the running bandwidth of the task, without trying to re-arm the 0-lag timer.

Signed-off-by: luca abeni &lt;luca.abeni@santannapisa.it&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Acked-by: Juri Lelli &lt;juri.lelli@redhat.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: chengjian (D) &lt;cj.chengjian@huawei.com&gt;
Link: https://lkml.kernel.org/r/20190325131530.34706-1-luca.abeni@santannapisa.it
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>sched/fair: Limit sched_cfs_period_timer() loop to avoid hard lockup</title>
<updated>2019-04-16T14:50:05+00:00</updated>
<author>
<name>Phil Auld</name>
<email>pauld@redhat.com</email>
</author>
<published>2019-03-19T13:00:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=2e8e19226398db8265a8e675fcc0118b9e80c9e8'/>
<id>2e8e19226398db8265a8e675fcc0118b9e80c9e8</id>
<content type='text'>
With extremely short cfs_period_us setting on a parent task group with a large
number of children the for loop in sched_cfs_period_timer() can run until the
watchdog fires. There is no guarantee that the call to hrtimer_forward_now()
will ever return 0.  The large number of children can make
do_sched_cfs_period_timer() take longer than the period.

 NMI watchdog: Watchdog detected hard LOCKUP on cpu 24
 RIP: 0010:tg_nop+0x0/0x10
  &lt;IRQ&gt;
  walk_tg_tree_from+0x29/0xb0
  unthrottle_cfs_rq+0xe0/0x1a0
  distribute_cfs_runtime+0xd3/0xf0
  sched_cfs_period_timer+0xcb/0x160
  ? sched_cfs_slack_timer+0xd0/0xd0
  __hrtimer_run_queues+0xfb/0x270
  hrtimer_interrupt+0x122/0x270
  smp_apic_timer_interrupt+0x6a/0x140
  apic_timer_interrupt+0xf/0x20
  &lt;/IRQ&gt;

To prevent this we add protection to the loop that detects when the loop has run
too many times and scales the period and quota up, proportionally, so that the timer
can complete before then next period expires.  This preserves the relative runtime
quota while preventing the hard lockup.

A warning is issued reporting this state and the new values.

Signed-off-by: Phil Auld &lt;pauld@redhat.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Cc: Anton Blanchard &lt;anton@ozlabs.org&gt;
Cc: Ben Segall &lt;bsegall@google.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Link: https://lkml.kernel.org/r/20190319130005.25492-1-pauld@redhat.com
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
With extremely short cfs_period_us setting on a parent task group with a large
number of children the for loop in sched_cfs_period_timer() can run until the
watchdog fires. There is no guarantee that the call to hrtimer_forward_now()
will ever return 0.  The large number of children can make
do_sched_cfs_period_timer() take longer than the period.

 NMI watchdog: Watchdog detected hard LOCKUP on cpu 24
 RIP: 0010:tg_nop+0x0/0x10
  &lt;IRQ&gt;
  walk_tg_tree_from+0x29/0xb0
  unthrottle_cfs_rq+0xe0/0x1a0
  distribute_cfs_runtime+0xd3/0xf0
  sched_cfs_period_timer+0xcb/0x160
  ? sched_cfs_slack_timer+0xd0/0xd0
  __hrtimer_run_queues+0xfb/0x270
  hrtimer_interrupt+0x122/0x270
  smp_apic_timer_interrupt+0x6a/0x140
  apic_timer_interrupt+0xf/0x20
  &lt;/IRQ&gt;

To prevent this we add protection to the loop that detects when the loop has run
too many times and scales the period and quota up, proportionally, so that the timer
can complete before then next period expires.  This preserves the relative runtime
quota while preventing the hard lockup.

A warning is issued reporting this state and the new values.

Signed-off-by: Phil Auld &lt;pauld@redhat.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Cc: Anton Blanchard &lt;anton@ozlabs.org&gt;
Cc: Ben Segall &lt;bsegall@google.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Link: https://lkml.kernel.org/r/20190319130005.25492-1-pauld@redhat.com
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
