linux.git/kernel, branch v3.18.111

kdb: make "mdr" command repeat

2018-05-30T05:47:45+00:00

[ Upstream commit 1e0ce03bf142454f38a5fc050bf4fd698d2d36d8 ]

The "mdr" command should repeat (continue) when only Enter/Return
is pressed, so make it do so.

Signed-off-by: Randy Dunlap 
Cc: Daniel Thompson 
Cc: Jason Wessel 
Cc: kgdb-bugreport@lists.sourceforge.net
Signed-off-by: Jason Wessel 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

audit: return on memory error to avoid null pointer dereference

2018-05-30T05:47:44+00:00

[ Upstream commit 23138ead270045f1b3e912e667967b6094244999 ]

If there is a memory allocation error when trying to change an audit
kernel feature value, the ignored allocation error will trigger a NULL
pointer dereference oops on subsequent use of that pointer.  Return
instead.

Passes audit-testsuite.
See: https://github.com/linux-audit/audit-kernel/issues/76

Signed-off-by: Richard Guy Briggs 
[PM: not necessary (other funcs check for NULL), but a good practice]
Signed-off-by: Paul Moore 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

perf/core: Fix perf_output_read_group()

2018-05-30T05:47:42+00:00

[ Upstream commit 9e5b127d6f33468143d90c8a45ca12410e4c3fa7 ]

Mark reported his arm64 perf fuzzer runs sometimes splat like:

  armv8pmu_read_counter+0x1e8/0x2d8
  armpmu_event_update+0x8c/0x188
  armpmu_read+0xc/0x18
  perf_output_read+0x550/0x11e8
  perf_event_read_event+0x1d0/0x248
  perf_event_exit_task+0x468/0xbb8
  do_exit+0x690/0x1310
  do_group_exit+0xd0/0x2b0
  get_signal+0x2e8/0x17a8
  do_signal+0x144/0x4f8
  do_notify_resume+0x148/0x1e8
  work_pending+0x8/0x14

which asserts that we only call pmu::read() on ACTIVE events.

The above callchain does:

  perf_event_exit_task()
    perf_event_exit_task_context()
      task_ctx_sched_out() // INACTIVE
      perf_event_exit_event()
        perf_event_set_state(EXIT) // EXIT
        sync_child_event()
          perf_event_read_event()
            perf_output_read()
              perf_output_read_group()
                leader->pmu->read()

Which results in doing a pmu::read() on an !ACTIVE event.

I _think_ this is 'new' since we added attr.inherit_stat, which added
the perf_event_read_event() to the exit path, without that
perf_event_read_output() would only trigger from samples and for
@event to trigger a sample, it's leader _must_ be ACTIVE too.

Still, adding this check makes it consistent with the @sub case for
the siblings.

Reported-and-Tested-by: Mark Rutland 
Signed-off-by: Peter Zijlstra (Intel) 
Cc: Alexander Shishkin 
Cc: Arnaldo Carvalho de Melo 
Cc: Jiri Olsa 
Cc: Linus Torvalds 
Cc: Stephane Eranian 
Cc: Thomas Gleixner 
Cc: Vince Weaver 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

sched/rt: Fix rq->clock_update_flags < RQCF_ACT_SKIP warning

2018-05-30T05:47:39+00:00

[ Upstream commit d29a20645d5e929aa7e8616f28e5d8e1c49263ec ]

While running rt-tests' pi_stress program I got the following splat:

  rq->clock_update_flags < RQCF_ACT_SKIP
  WARNING: CPU: 27 PID: 0 at kernel/sched/sched.h:960 assert_clock_updated.isra.38.part.39+0x13/0x20

  [...]

  
  enqueue_top_rt_rq+0xf4/0x150
  ? cpufreq_dbs_governor_start+0x170/0x170
  sched_rt_rq_enqueue+0x65/0x80
  sched_rt_period_timer+0x156/0x360
  ? sched_rt_rq_enqueue+0x80/0x80
  __hrtimer_run_queues+0xfa/0x260
  hrtimer_interrupt+0xcb/0x220
  smp_apic_timer_interrupt+0x62/0x120
  apic_timer_interrupt+0xf/0x20
  

  [...]

  do_idle+0x183/0x1e0
  cpu_startup_entry+0x5f/0x70
  start_secondary+0x192/0x1d0
  secondary_startup_64+0xa5/0xb0

We can get rid of it be the "traditional" means of adding an
update_rq_clock() call after acquiring the rq->lock in
do_sched_rt_period_timer().

The case for the RT task throttling (which this workload also hits)
can be ignored in that the skip_update call is actually bogus and
quite the contrary (the request bits are removed/reverted).

By setting RQCF_UPDATED we really don't care if the skip is happening
or not and will therefore make the assert_clock_updated() check happy.

Signed-off-by: Davidlohr Bueso 
Reviewed-by: Matt Fleming 
Acked-by: Peter Zijlstra (Intel) 
Cc: Linus Torvalds 
Cc: Mike Galbraith 
Cc: Thomas Gleixner 
Cc: dave@stgolabs.net
Cc: linux-kernel@vger.kernel.org
Cc: rostedt@goodmis.org
Link: http://lkml.kernel.org/r/20180402164954.16255-1-dave@stgolabs.net
Signed-off-by: Ingo Molnar 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

kernel/relay.c: limit kmalloc size to KMALLOC_MAX_SIZE

2018-05-30T05:47:34+00:00

[ Upstream commit 88913bd8ea2a75d7e460a4bed5f75e1c32660d7e ]

chan->n_subbufs is set by the user and relay_create_buf() does a kmalloc()
of chan->n_subbufs * sizeof(size_t *).

kmalloc_slab() will generate a warning when this fails if
chan->subbufs * sizeof(size_t *) > KMALLOC_MAX_SIZE.

Limit chan->n_subbufs to the maximum allowed kmalloc() size.

Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1802061216100.122576@chino.kir.corp.google.com
Fixes: f6302f1bcd75 ("relay: prevent integer overflow in relay_open()")
Signed-off-by: David Rientjes 
Reviewed-by: Andrew Morton 
Cc: Jens Axboe 
Cc: Dave Jiang 
Cc: Al Viro 
Cc: Dan Carpenter 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

x86/power: Fix swsusp_arch_resume prototype

2018-05-30T05:47:31+00:00

[ Upstream commit 328008a72d38b5bde6491e463405c34a81a65d3e ]

The declaration for swsusp_arch_resume marks it as 'asmlinkage', but the
definition in x86-32 does not, and it fails to include the header with the
declaration. This leads to a warning when building with
link-time-optimizations:

kernel/power/power.h:108:23: error: type of 'swsusp_arch_resume' does not match original declaration [-Werror=lto-type-mismatch]
 extern asmlinkage int swsusp_arch_resume(void);
                       ^
arch/x86/power/hibernate_32.c:148:0: note: 'swsusp_arch_resume' was previously declared here
 int swsusp_arch_resume(void)

This moves the declaration into a globally visible header file and fixes up
both x86 definitions to match it.

Signed-off-by: Arnd Bergmann 
Signed-off-by: Thomas Gleixner 
Cc: Len Brown 
Cc: Andi Kleen 
Cc: Nicolas Pitre 
Cc: linux-pm@vger.kernel.org
Cc: "Rafael J. Wysocki" 
Cc: Pavel Machek 
Cc: Bart Van Assche 
Link: https://lkml.kernel.org/r/20180202145634.200291-2-arnd@arndb.de
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

kernel/signal.c: avoid undefined behaviour in kill_something_info

2018-05-30T05:47:29+00:00

commit 4ea77014af0d6205b05503d1c7aac6eace11d473 upstream.

When running kill(72057458746458112, 0) in userspace I hit the following
issue.

  UBSAN: Undefined behaviour in kernel/signal.c:1462:11
  negation of -2147483648 cannot be represented in type 'int':
  CPU: 226 PID: 9849 Comm: test Tainted: G    B          ---- -------   3.10.0-327.53.58.70.x86_64_ubsan+ #116
  Hardware name: Huawei Technologies Co., Ltd. RH8100 V3/BC61PBIA, BIOS BLHSV028 11/11/2014
  Call Trace:
    dump_stack+0x19/0x1b
    ubsan_epilogue+0xd/0x50
    __ubsan_handle_negate_overflow+0x109/0x14e
    SYSC_kill+0x43e/0x4d0
    SyS_kill+0xe/0x10
    system_call_fastpath+0x16/0x1b

Add code to avoid the UBSAN detection.

[akpm@linux-foundation.org: tweak comment]
Link: http://lkml.kernel.org/r/1496670008-59084-1-git-send-email-zhongjiang@huawei.com
Signed-off-by: zhongjiang 
Cc: Oleg Nesterov 
Cc: Michal Hocko 
Cc: Vlastimil Babka 
Cc: Xishi Qiu 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Cc: Guenter Roeck 
Signed-off-by: Greg Kroah-Hartman

tick/broadcast: Use for_each_cpu() specially on UP kernels

2018-05-25T08:54:54+00:00

commit 5596fe34495cf0f645f417eb928ef224df3e3cb4 upstream.

for_each_cpu() unintuitively reports CPU0 as set independent of the actual
cpumask content on UP kernels. This causes an unexpected PIT interrupt
storm on a UP kernel running in an SMP virtual machine on Hyper-V, and as
a result, the virtual machine can suffer from a strange random delay of 1~20
minutes during boot-up, and sometimes it can hang forever.

Protect if by checking whether the cpumask is empty before entering the
for_each_cpu() loop.

[ tglx: Use !IS_ENABLED(CONFIG_SMP) instead of #ifdeffery ]

Signed-off-by: Dexuan Cui 
Signed-off-by: Thomas Gleixner 
Cc: Josh Poulson 
Cc: "Michael Kelley (EOSG)" 
Cc: Peter Zijlstra 
Cc: Frederic Weisbecker 
Cc: stable@vger.kernel.org
Cc: Rakib Mullick 
Cc: Jork Loeser 
Cc: Greg Kroah-Hartman 
Cc: Andrew Morton 
Cc: KY Srinivasan 
Cc: Linus Torvalds 
Cc: Alexey Dobriyan 
Cc: Dmitry Vyukov 
Link: https://lkml.kernel.org/r/KL1P15301MB000678289FE55BA365B3279ABF990@KL1P15301MB0006.APCP153.PROD.OUTLOOK.COM
Link: https://lkml.kernel.org/r/KL1P15301MB0006FA63BC22BEB64902EAA0BF930@KL1P15301MB0006.APCP153.PROD.OUTLOOK.COM
Signed-off-by: Greg Kroah-Hartman

kernel/exit.c: avoid undefined behaviour when calling wait4()

2018-05-25T08:54:53+00:00

commit dd83c161fbcc5d8be637ab159c0de015cbff5ba4 upstream.

wait4(-2147483648, 0x20, 0, 0xdd0000) triggers:
UBSAN: Undefined behaviour in kernel/exit.c:1651:9

The related calltrace is as follows:

  negation of -2147483648 cannot be represented in type 'int':
  CPU: 9 PID: 16482 Comm: zj Tainted: G    B          ---- -------   3.10.0-327.53.58.71.x86_64+ #66
  Hardware name: Huawei Technologies Co., Ltd. Tecal RH2285          /BC11BTSA              , BIOS CTSAV036 04/27/2011
  Call Trace:
    dump_stack+0x19/0x1b
    ubsan_epilogue+0xd/0x50
    __ubsan_handle_negate_overflow+0x109/0x14e
    SyS_wait4+0x1cb/0x1e0
    system_call_fastpath+0x16/0x1b

Exclude the overflow to avoid the UBSAN warning.

Link: http://lkml.kernel.org/r/1497264618-20212-1-git-send-email-zhongjiang@huawei.com
Signed-off-by: zhongjiang 
Cc: Oleg Nesterov 
Cc: David Rientjes 
Cc: Aneesh Kumar K.V 
Cc: Kirill A. Shutemov 
Cc: Xishi Qiu 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

tracing/uprobe_event: Fix strncpy corner case

2018-05-16T08:05:18+00:00

commit 50268a3d266ecfdd6c5873d62b2758d9732fc598 upstream.

Fix string fetch function to terminate with NUL.
It is OK to drop the rest of string.

Signed-off-by: Masami Hiramatsu 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Song Liu 
Cc: Thomas Gleixner 
Cc: security@kernel.org
Cc: 范龙飞 
Fixes: 5baaa59ef09e ("tracing/probes: Implement 'memory' fetch method for uprobes")
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman