linux-stable.git/kernel, branch v3.16.63

tracing: Fix memory leak of instance function hash filters

2019-02-11T17:54:24+00:00

commit 2840f84f74035e5a535959d5f17269c69fa6edc5 upstream.

The following commands will cause a memory leak:

 # cd /sys/kernel/tracing
 # mkdir instances/foo
 # echo schedule > instance/foo/set_ftrace_filter
 # rmdir instances/foo

The reason is that the hashes that hold the filters to set_ftrace_filter and
set_ftrace_notrace are not freed if they contain any data on the instance
and the instance is removed.

Found by kmemleak detector.

Fixes: 591dffdade9f ("ftrace: Allow for function tracing instance to filter functions")
Signed-off-by: Steven Rostedt (VMware) 
Signed-off-by: Ben Hutchings

tracing: Fix memory leak in set_trigger_filter()

2019-02-11T17:54:24+00:00

commit 3cec638b3d793b7cacdec5b8072364b41caeb0e1 upstream.

When create_event_filter() fails in set_trigger_filter(), the filter may
still be allocated and needs to be freed. The caller expects the
data->filter to be updated with the new filter, even if the new filter
failed (we could add an error message by setting set_str parameter of
create_event_filter(), but that's another update).

But because the error would just exit, filter was left hanging and
nothing could free it.

Found by kmemleak detector.

Fixes: bac5fb97a173a ("tracing: Add and use generic set_trigger_filter() implementation")
Reviewed-by: Tom Zanussi 
Signed-off-by: Steven Rostedt (VMware) 
Signed-off-by: Ben Hutchings

uprobes: Fix handle_swbp() vs. unregister() + register() race once more

2019-02-11T17:54:10+00:00

commit 09d3f015d1e1b4fee7e9bbdcf54201d239393391 upstream.

Commit:

  142b18ddc8143 ("uprobes: Fix handle_swbp() vs unregister() + register() race")

added the UPROBE_COPY_INSN flag, and corresponding smp_wmb() and smp_rmb()
memory barriers, to ensure that handle_swbp() uses fully-initialized
uprobes only.

However, the smp_rmb() is mis-placed: this barrier should be placed
after handle_swbp() has tested for the flag, thus guaranteeing that
(program-order) subsequent loads from the uprobe can see the initial
stores performed by prepare_uprobe().

Move the smp_rmb() accordingly.  Also amend the comments associated
to the two memory barriers to indicate their actual locations.

Signed-off-by: Andrea Parri 
Acked-by: Oleg Nesterov 
Cc: Alexander Shishkin 
Cc: Andrew Morton 
Cc: Arnaldo Carvalho de Melo 
Cc: Jiri Olsa 
Cc: Linus Torvalds 
Cc: Namhyung Kim 
Cc: Paul E. McKenney 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Cc: Thomas Gleixner 
Cc: Vince Weaver 
Fixes: 142b18ddc8143 ("uprobes: Fix handle_swbp() vs unregister() + register() race")
Link: http://lkml.kernel.org/r/20181122161031.15179-1-andrea.parri@amarulasolutions.com
Signed-off-by: Ingo Molnar 
Signed-off-by: Ben Hutchings

kbuild: fix kernel/bounds.c 'W=1' warning

2019-02-11T17:53:44+00:00

commit 6a32c2469c3fbfee8f25bcd20af647326650a6cf upstream.

Building any configuration with 'make W=1' produces a warning:

kernel/bounds.c:16:6: warning: no previous prototype for 'foo' [-Wmissing-prototypes]

When also passing -Werror, this prevents us from building any other files.
Nobody ever calls the function, but we can't make it 'static' either
since we want the compiler output.

Calling it 'main' instead however avoids the warning, because gcc
does not insist on having a declaration for main.

Link: http://lkml.kernel.org/r/20181005083313.2088252-1-arnd@arndb.de
Signed-off-by: Arnd Bergmann 
Reported-by: Kieran Bingham 
Reviewed-by: Kieran Bingham 
Cc: David Laight 
Cc: Masahiro Yamada 
Cc: Greg Kroah-Hartman 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Ben Hutchings

genirq: Fix race on spurious interrupt detection

2019-02-11T17:53:38+00:00

commit 746a923b863a1065ef77324e1e43f19b1a3eab5c upstream.

Commit 1e77d0a1ed74 ("genirq: Sanitize spurious interrupt detection of
threaded irqs") made detection of spurious interrupts work for threaded
handlers by:

a) incrementing a counter every time the thread returns IRQ_HANDLED, and
b) checking whether that counter has increased every time the thread is
   woken.

However for oneshot interrupts, the commit unmasks the interrupt before
incrementing the counter.  If another interrupt occurs right after
unmasking but before the counter is incremented, that interrupt is
incorrectly considered spurious:

time
 |  irq_thread()
 |    irq_thread_fn()
 |      action->thread_fn()
 |      irq_finalize_oneshot()
 |        unmask_threaded_irq()            /* interrupt is unmasked */
 |
 |                  /* interrupt fires, incorrectly deemed spurious */
 |
 |    atomic_inc(&desc->threads_handled); /* counter is incremented */
 v

This is observed with a hi3110 CAN controller receiving data at high volume
(from a separate machine sending with "cangen -g 0 -i -x"): The controller
signals a huge number of interrupts (hundreds of millions per day) and
every second there are about a dozen which are deemed spurious.

In theory with high CPU load and the presence of higher priority tasks, the
number of incorrectly detected spurious interrupts might increase beyond
the 99,900 threshold and cause disablement of the interrupt.

In practice it just increments the spurious interrupt count. But that can
cause people to waste time investigating it over and over.

Fix it by moving the accounting before the invocation of
irq_finalize_oneshot().

[ tglx: Folded change log update ]

Fixes: 1e77d0a1ed74 ("genirq: Sanitize spurious interrupt detection of threaded irqs")
Signed-off-by: Lukas Wunner 
Signed-off-by: Thomas Gleixner 
Cc: Mathias Duckeck 
Cc: Akshay Bhat 
Cc: Casey Fitzpatrick 
Link: https://lkml.kernel.org/r/1dfd8bbd16163940648045495e3e9698e63b50ad.1539867047.git.lukas@wunner.de
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings

printk: Fix panic caused by passing log_buf_len to command line

2019-02-11T17:53:28+00:00

commit 277fcdb2cfee38ccdbe07e705dbd4896ba0c9930 upstream.

log_buf_len_setup does not check input argument before passing it to
simple_strtoull. The argument would be a NULL pointer if "log_buf_len",
without its value, is set in command line and thus causes the following
panic.

PANIC: early exception 0xe3 IP 10:ffffffffaaeacd0d error 0 cr2 0x0
[    0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 4.19.0-rc4-yocto-standard+ #1
[    0.000000] RIP: 0010:_parse_integer_fixup_radix+0xd/0x70
...
[    0.000000] Call Trace:
[    0.000000]  simple_strtoull+0x29/0x70
[    0.000000]  memparse+0x26/0x90
[    0.000000]  log_buf_len_setup+0x17/0x22
[    0.000000]  do_early_param+0x57/0x8e
[    0.000000]  parse_args+0x208/0x320
[    0.000000]  ? rdinit_setup+0x30/0x30
[    0.000000]  parse_early_options+0x29/0x2d
[    0.000000]  ? rdinit_setup+0x30/0x30
[    0.000000]  parse_early_param+0x36/0x4d
[    0.000000]  setup_arch+0x336/0x99e
[    0.000000]  start_kernel+0x6f/0x4ee
[    0.000000]  x86_64_start_reservations+0x24/0x26
[    0.000000]  x86_64_start_kernel+0x6f/0x72
[    0.000000]  secondary_startup_64+0xa4/0xb0

This patch adds a check to prevent the panic.

Link: http://lkml.kernel.org/r/1538239553-81805-1-git-send-email-zhe.he@windriver.com
Cc: rostedt@goodmis.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: He Zhe 
Reviewed-by: Sergey Senozhatsky 
Signed-off-by: Petr Mladek 
Signed-off-by: Ben Hutchings

signal: Always deliver the kernel's SIGKILL and SIGSTOP to a pid namespace init

2019-02-11T17:53:18+00:00

commit 3597dfe01d12f570bc739da67f857fd222a3ea66 upstream.

Instead of playing whack-a-mole and changing SEND_SIG_PRIV to
SEND_SIG_FORCED throughout the kernel to ensure a pid namespace init
gets signals sent by the kernel, stop allowing a pid namespace init to
ignore SIGKILL or SIGSTOP sent by the kernel.  A pid namespace init is
only supposed to be able to ignore signals sent from itself and
children with SIG_DFL.

Fixes: 921cf9f63089 ("signals: protect cinit from unblocked SIG_DFL signals")
Reviewed-by: Thomas Gleixner 
Signed-off-by: "Eric W. Biederman" 
Signed-off-by: Ben Hutchings

timer/debug: Change /proc/timer_list from 0444 to 0400

2019-02-11T17:53:14+00:00

commit 8e7df2b5b7f245c9bd11064712db5cb69044a362 upstream.

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

Suggested-by: Linus Torvalds 
Acked-by: Thomas Gleixner 
Cc: Peter Zijlstra 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar 
Signed-off-by: Ben Hutchings

posix-timers: Sanitize overrun handling

2018-12-16T22:09:45+00:00

commit 78c9c4dfbf8c04883941445a195276bb4bb92c76 upstream.

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 
Signed-off-by: Thomas Gleixner 
Acked-by: John Stultz 
Cc: Peter Zijlstra 
Cc: Michael Kerrisk 
Link: https://lkml.kernel.org/r/20180626132705.018623573@linutronix.de
[bwh: Backported to 3.16: adjust filenames, context]
Signed-off-by: Ben Hutchings

cpuidle: Do not access cpuidle_devices when !CONFIG_CPU_IDLE

2018-12-16T22:09:44+00:00

commit 9bd616e3dbedfc103f158197c8ad93678849b1ed upstream.

The cpuidle_devices per-CPU variable is only defined when CPU_IDLE is
enabled. Commit c8cc7d4de7a4 ("sched/idle: Reorganize the idle loop")
removed the #ifdef CONFIG_CPU_IDLE around cpuidle_idle_call() with the
compiler optimising away __this_cpu_read(cpuidle_devices). However, with
CONFIG_UBSAN && !CONFIG_CPU_IDLE, this optimisation no longer happens
and the kernel fails to link since cpuidle_devices is not defined.

This patch introduces an accessor function for the current CPU cpuidle
device (returning NULL when !CONFIG_CPU_IDLE) and uses it in
cpuidle_idle_call().

Signed-off-by: Catalin Marinas 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Ben Hutchings