Commit Graph

1266 Commits

Author SHA1 Message Date
Huang, Tao
6ee6d6d68b Merge tag 'lsk-v4.4-17.07-android' of git://git.linaro.org/kernel/linux-linaro-stable.git
LSK 17.07 v4.4-android

* tag 'lsk-v4.4-17.07-android': (402 commits)
  dt/vendor-prefixes: remove redundant vendor
  Linux 4.4.77
  saa7134: fix warm Medion 7134 EEPROM read
  x86/mm/pat: Don't report PAT on CPUs that don't support it
  ext4: check return value of kstrtoull correctly in reserved_clusters_store
  staging: comedi: fix clean-up of comedi_class in comedi_init()
  staging: vt6556: vnt_start Fix missing call to vnt_key_init_table.
  tcp: fix tcp_mark_head_lost to check skb len before fragmenting
  md: fix super_offset endianness in super_1_rdev_size_change
  md: fix incorrect use of lexx_to_cpu in does_sb_need_changing
  perf tools: Use readdir() instead of deprecated readdir_r() again
  perf tests: Remove wrong semicolon in while loop in CQM test
  perf trace: Do not process PERF_RECORD_LOST twice
  perf dwarf: Guard !x86_64 definitions under #ifdef else clause
  perf pmu: Fix misleadingly indented assignment (whitespace)
  perf annotate browser: Fix behaviour of Shift-Tab with nothing focussed
  perf tools: Remove duplicate const qualifier
  perf script: Use readdir() instead of deprecated readdir_r()
  perf thread_map: Use readdir() instead of deprecated readdir_r()
  perf tools: Use readdir() instead of deprecated readdir_r()
  ...

Conflicts:
	Makefile
	drivers/Kconfig
	drivers/Makefile
	drivers/usb/dwc3/gadget.c

Change-Id: Ib4aae2e34ebbf0d7953c748a33f673acb3e744fc
2017-07-26 19:32:04 +08:00
Alex Shi
2120557722 Merge branch 'linux-linaro-lsk-v4.4' into linux-linaro-lsk-v4.4-android
Conflicts:
	arch/arm64/kernel/armv8_deprecated.c
	arch/arm64/kernel/efi.c
	arch/arm64/kernel/entry.S
	arch/arm64/kernel/head.S
	arch/arm64/kernel/hw_breakpoint.c
	arch/arm64/mm/mmu.c
	include/linux/memblock.h
	mm/memblock.c
2017-07-11 16:22:22 +08:00
John Stultz
1fecf3977d time: Fix clock->read(clock) race around clocksource changes
commit ceea5e3771ed2378668455fa21861bead7504df5 upstream.

In tests, which excercise switching of clocksources, a NULL
pointer dereference can be observed on AMR64 platforms in the
clocksource read() function:

u64 clocksource_mmio_readl_down(struct clocksource *c)
{
	return ~(u64)readl_relaxed(to_mmio_clksrc(c)->reg) & c->mask;
}

This is called from the core timekeeping code via:

	cycle_now = tkr->read(tkr->clock);

tkr->read is the cached tkr->clock->read() function pointer.
When the clocksource is changed then tkr->clock and tkr->read
are updated sequentially. The code above results in a sequential
load operation of tkr->read and tkr->clock as well.

If the store to tkr->clock hits between the loads of tkr->read
and tkr->clock, then the old read() function is called with the
new clock pointer. As a consequence the read() function
dereferences a different data structure and the resulting 'reg'
pointer can point anywhere including NULL.

This problem was introduced when the timekeeping code was
switched over to use struct tk_read_base. Before that, it was
theoretically possible as well when the compiler decided to
reload clock in the code sequence:

     now = tk->clock->read(tk->clock);

Add a helper function which avoids the issue by reading
tk_read_base->clock once into a local variable clk and then issue
the read function via clk->read(clk). This guarantees that the
read() function always gets the proper clocksource pointer handed
in.

Since there is now no use for the tkr.read pointer, this patch
also removes it, and to address stopping the fast timekeeper
during suspend/resume, it introduces a dummy clocksource to use
rather then just a dummy read function.

Signed-off-by: John Stultz <john.stultz@linaro.org>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Stephen Boyd <stephen.boyd@linaro.org>
Cc: Miroslav Lichvar <mlichvar@redhat.com>
Cc: Daniel Mentz <danielmentz@google.com>
Link: http://lkml.kernel.org/r/1496965462-20003-2-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-29 12:48:51 +02:00
Thomas Gleixner
26605a06dd alarmtimer: Rate limit periodic intervals
commit ff86bf0c65f14346bf2440534f9ba5ac232c39a0 upstream.

The alarmtimer code has another source of potentially rearming itself too
fast. Interval timers with a very samll interval have a similar CPU hog
effect as the previously fixed overflow issue.

The reason is that alarmtimers do not implement the normal protection
against this kind of problem which the other posix timer use:

  timer expires -> queue signal -> deliver signal -> rearm timer

This scheme brings the rearming under scheduler control and prevents
permanently firing timers which hog the CPU.

Bringing this scheme to the alarm timer code is a major overhaul because it
lacks all the necessary mechanisms completely.

So for a quick fix limit the interval to one jiffie. This is not
problematic in practice as alarmtimers are usually backed by an RTC for
suspend which have 1 second resolution. It could be therefor argued that
the resolution of this clock should be set to 1 second in general, but
that's outside the scope of this fix.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Kostya Serebryany <kcc@google.com>
Cc: syzkaller <syzkaller@googlegroups.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Link: http://lkml.kernel.org/r/20170530211655.896767100@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-26 07:13:11 +02:00
Thomas Gleixner
aac7fa215e alarmtimer: Prevent overflow of relative timers
commit f4781e76f90df7aec400635d73ea4c35ee1d4765 upstream.

Andrey reported a alartimer related RCU stall while fuzzing the kernel with
syzkaller.

The reason for this is an overflow in ktime_add() which brings the
resulting time into negative space and causes immediate expiry of the
timer. The following rearm with a small interval does not bring the timer
back into positive space due to the same issue.

This results in a permanent firing alarmtimer which hogs the CPU.

Use ktime_add_safe() instead which detects the overflow and clamps the
result to KTIME_SEC_MAX.

Reported-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Kostya Serebryany <kcc@google.com>
Cc: syzkaller <syzkaller@googlegroups.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Link: http://lkml.kernel.org/r/20170530211655.802921648@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-26 07:13:10 +02:00
Huang, Tao
5ed6b099c8 Merge branch 'linux-linaro-lsk-v4.4-android' of git://git.linaro.org/kernel/linux-linaro-stable.git
* linux-linaro-lsk-v4.4-android: (434 commits)
  Linux 4.4.52
  kvm: vmx: ensure VMCS is current while enabling PML
  Revert "usb: chipidea: imx: enable CI_HDRC_SET_NON_ZERO_TTHA"
  rtlwifi: rtl_usb: Fix for URB leaking when doing ifconfig up/down
  block: fix double-free in the failure path of cgwb_bdi_init()
  goldfish: Sanitize the broken interrupt handler
  x86/platform/goldfish: Prevent unconditional loading
  USB: serial: ark3116: fix register-accessor error handling
  USB: serial: opticon: fix CTS retrieval at open
  USB: serial: spcp8x5: fix modem-status handling
  USB: serial: ftdi_sio: fix line-status over-reporting
  USB: serial: ftdi_sio: fix extreme low-latency setting
  USB: serial: ftdi_sio: fix modem-status error handling
  USB: serial: cp210x: add new IDs for GE Bx50v3 boards
  USB: serial: mos7840: fix another NULL-deref at open
  tty: serial: msm: Fix module autoload
  net: socket: fix recvmmsg not returning error from sock_error
  ip: fix IP_CHECKSUM handling
  irda: Fix lockdep annotations in hashbin_delete().
  dccp: fix freeing skb too early for IPV6_RECVPKTINFO
  ...

Conflicts:
	drivers/mmc/core/mmc.c
	drivers/usb/dwc3/ep0.c
	drivers/usb/host/xhci.h

Change-Id: Icf331a68162ab686d01996a3f43fa2e97543f62e
2017-03-01 18:40:28 +08:00
Alex Shi
e30546378e Merge branch 'linux-linaro-lsk-v4.4' into linux-linaro-lsk-v4.4-android 2017-01-13 12:01:52 +08:00
Thomas Gleixner
6053479cbb tick/broadcast: Prevent NULL pointer dereference
commit c1a9eeb938b5433947e5ea22f89baff3182e7075 upstream.

When a disfunctional timer, e.g. dummy timer, is installed, the tick core
tries to setup the broadcast timer.

If no broadcast device is installed, the kernel crashes with a NULL pointer
dereference in tick_broadcast_setup_oneshot() because the function has no
sanity check.

Reported-by: Mason <slash.tmp@free.fr>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Anna-Maria Gleixner <anna-maria@linutronix.de>
Cc: Richard Cochran <rcochran@linutronix.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>,
Cc: Sebastian Frias <sf84@laposte.net>
Cc: Thibaud Cornic <thibaud_cornic@sigmadesigns.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Link: http://lkml.kernel.org/r/1147ef90-7877-e4d2-bb2b-5c4fa8d3144b@free.fr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-12 11:22:51 +01:00
Huang, Tao
7b2f394bb8 Merge branch 'linux-linaro-lsk-v4.4-android' of git://git.linaro.org/kernel/linux-linaro-stable.git
* linux-linaro-lsk-v4.4-android: (199 commits)
  Linux 4.4.41
  net: mvpp2: fix dma unmapping of TX buffers for fragments
  sg_write()/bsg_write() is not fit to be called under KERNEL_DS
  kconfig/nconf: Fix hang when editing symbol with a long prompt
  target/user: Fix use-after-free of tcmu_cmds if they are expired
  powerpc: Convert cmp to cmpd in idle enter sequence
  powerpc/ps3: Fix system hang with GCC 5 builds
  nfs_write_end(): fix handling of short copies
  libceph: verify authorize reply on connect
  PCI: Check for PME in targeted sleep state
  Input: drv260x - fix input device's parent assignment
  media: solo6x10: fix lockup by avoiding delayed register write
  IB/cma: Fix a race condition in iboe_addr_get_sgid()
  IB/multicast: Check ib_find_pkey() return value
  IPoIB: Avoid reading an uninitialized member variable
  IB/mad: Fix an array index check
  fgraph: Handle a case where a tracer ignores set_graph_notrace
  platform/x86: asus-nb-wmi.c: Add X45U quirk
  ftrace/x86_32: Set ftrace_stub to weak to prevent gcc from using short jumps to it
  kvm: nVMX: Allow L1 to intercept software exceptions (#BP and #OF)
  ...

Change-Id: I8c8467700d5563d9a1121c982737ff0ab6d9cdc9
2017-01-10 16:07:06 +08:00
Alex Shi
7785301d92 Merge branch 'linux-linaro-lsk-v4.4' into linux-linaro-lsk-v4.4-android 2017-01-10 12:01:14 +08:00
Thomas Gleixner
e01b04be3e timekeeping_Force_unsigned_clocksource_to_nanoseconds_conversion
commit 9c1645727b8fa90d07256fdfcc45bf831242a3ab upstream.

The clocksource delta to nanoseconds conversion is using signed math, but
the delta is unsigned. This makes the conversion space smaller than
necessary and in case of a multiplication overflow the conversion can
become negative. The conversion is done with scaled math:

    s64 nsec_delta = ((s64)clkdelta * clk->mult) >> clk->shift;

Shifting a signed integer right obvioulsy preserves the sign, which has
interesting consequences:

 - Time jumps backwards

 - __iter_div_u64_rem() which is used in one of the calling code pathes
   will take forever to piecewise calculate the seconds/nanoseconds part.

This has been reported by several people with different scenarios:

David observed that when stopping a VM with a debugger:

 "It was essentially the stopped by debugger case.  I forget exactly why,
  but the guest was being explicitly stopped from outside, it wasn't just
  scheduling lag.  I think it was something in the vicinity of 10 minutes
  stopped."

 When lifting the stop the machine went dead.

The stopped by debugger case is not really interesting, but nevertheless it
would be a good thing not to die completely.

But this was also observed on a live system by Liav:

 "When the OS is too overloaded, delta will get a high enough value for the
  msb of the sum delta * tkr->mult + tkr->xtime_nsec to be set, and so
  after the shift the nsec variable will gain a value similar to
  0xffffffffff000000."

Unfortunately this has been reintroduced recently with commit 6bd58f09e1d8
("time: Add cycles to nanoseconds translation"). It had been fixed a year
ago already in commit 35a4933a8959 ("time: Avoid signed overflow in
timekeeping_get_ns()").

Though it's not surprising that the issue has been reintroduced because the
function itself and the whole call chain uses s64 for the result and the
propagation of it. The change in this recent commit is subtle:

   s64 nsec;

-  nsec = (d * m + n) >> s:
+  nsec = d * m + n;
+  nsec >>= s;

d being type of cycle_t adds another level of obfuscation.

This wouldn't have happened if the previous change to unsigned computation
would have made the 'nsec' variable u64 right away and a follow up patch
had cleaned up the whole call chain.

There have been patches submitted which basically did a revert of the above
patch leaving everything else unchanged as signed. Back to square one. This
spawned a admittedly pointless discussion about potential users which rely
on the unsigned behaviour until someone pointed out that it had been fixed
before. The changelogs of said patches added further confusion as they made
finally false claims about the consequences for eventual users which expect
signed results.

Despite delta being cycle_t, aka. u64, it's very well possible to hand in
a signed negative value and the signed computation will happily return the
correct result. But nobody actually sat down and analyzed the code which
was added as user after the propably unintended signed conversion.

Though in sensitive code like this it's better to analyze it proper and
make sure that nothing relies on this than hunting the subtle wreckage half
a year later. After analyzing all call chains it stands that no caller can
hand in a negative value (which actually would work due to the s64 cast)
and rely on the signed math to do the right thing.

Change the conversion function to unsigned math. The conversion of all call
chains is done in a follow up patch.

This solves the starvation issue, which was caused by the negative result,
but it does not solve the underlying problem. It merily procrastinates
it. When the timekeeper update is deferred long enough that the unsigned
multiplication overflows, then time going backwards is observable again.

It does neither solve the issue of clocksources with a small counter width
which will wrap around possibly several times and cause random time stamps
to be generated. But those are usually not found on systems used for
virtualization, so this is likely a non issue.

I took the liberty to claim authorship for this simply because
analyzing all callsites and writing the changelog took substantially
more time than just making the simple s/s64/u64/ change and ignore the
rest.

Fixes: 6bd58f09e1d8 ("time: Add cycles to nanoseconds translation")
Reported-by: David Gibson <david@gibson.dropbear.id.au>
Reported-by: Liav Rehana <liavr@mellanox.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Parit Bhargava <prarit@redhat.com>
Cc: Laurent Vivier <lvivier@redhat.com>
Cc: "Christopher S. Hall" <christopher.s.hall@intel.com>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20161208204228.688545601@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-09 08:07:43 +01:00
Huang, Tao
ef179e79e9 Merge branch 'linux-linaro-lsk-v4.4-android' of git://git.linaro.org/kernel/linux-linaro-stable.git
* linux-linaro-lsk-v4.4-android: (61 commits)
  Linux 4.4.36
  scsi: mpt3sas: Unblock device after controller reset
  flow_dissect: call init_default_flow_dissectors() earlier
  mei: fix return value on disconnection
  mei: me: fix place for kaby point device ids.
  mei: me: disable driver on SPT SPS firmware
  drm/radeon: Ensure vblank interrupt is enabled on DPMS transition to on
  mpi: Fix NULL ptr dereference in mpi_powm() [ver #3]
  parisc: Also flush data TLB in flush_icache_page_asm
  parisc: Fix race in pci-dma.c
  parisc: Fix races in parisc_setup_cache_timing()
  NFSv4.x: hide array-bounds warning
  apparmor: fix change_hat not finding hat after policy replacement
  cfg80211: limit scan results cache size
  tile: avoid using clocksource_cyc2ns with absolute cycle count
  scsi: mpt3sas: Fix secure erase premature termination
  Fix USB CB/CBI storage devices with CONFIG_VMAP_STACK=y
  USB: serial: ftdi_sio: add support for TI CC3200 LaunchPad
  USB: serial: cp210x: add ID for the Zone DPMX
  usb: chipidea: move the lock initialization to core file
  ...
2016-12-06 20:58:56 +08:00
Joel Fernandes
bcddfb47bf UPSTREAM: timekeeping: Add a fast and NMI safe boot clock
This boot clock can be used as a tracing clock and will account for
suspend time.

To keep it NMI safe since we're accessing from tracing, we're not using a
separate timekeeper with updates to monotonic clock and boot offset
protected with seqlocks. This has the following minor side effects:

(1) Its possible that a timestamp be taken after the boot offset is updated
but before the timekeeper is updated. If this happens, the new boot offset
is added to the old timekeeping making the clock appear to update slightly
earlier:
   CPU 0                                        CPU 1
   timekeeping_inject_sleeptime64()
   __timekeeping_inject_sleeptime(tk, delta);
                                                timestamp();
   timekeeping_update(tk, TK_CLEAR_NTP...);

(2) On 32-bit systems, the 64-bit boot offset (tk->offs_boot) may be
partially updated.  Since the tk->offs_boot update is a rare event, this
should be a rare occurrence which postprocessing should be able to handle.

Bug: b/33184060

Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Joel Fernandes <joelaf@google.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2016-12-01 15:18:44 +05:30
Huang, Tao
f9ae5d202b Merge branch 'linux-linaro-lsk-v4.4-android' of git://git.linaro.org/kernel/linux-linaro-stable.git
* linux-linaro-lsk-v4.4-android: (1362 commits)
  Linux 4.4.30
  Revert "fix minor infoleak in get_user_ex()"
  Revert "x86/mm: Expand the exception table logic to allow new handling options"
  Linux 4.4.29
  ARM: pxa: pxa_cplds: fix interrupt handling
  powerpc/nvram: Fix an incorrect partition merge
  mpt3sas: Don't spam logs if logging level is 0
  perf symbols: Fixup symbol sizes before picking best ones
  perf symbols: Check symbol_conf.allow_aliases for kallsyms loading too
  perf hists browser: Fix event group display
  clk: divider: Fix clk_divider_round_rate() to use clk_readl()
  clk: qoriq: fix a register offset error
  s390/con3270: fix insufficient space padding
  s390/con3270: fix use of uninitialised data
  s390/cio: fix accidental interrupt enabling during resume
  x86/mm: Expand the exception table logic to allow new handling options
  dmaengine: ipu: remove bogus NO_IRQ reference
  power: bq24257: Fix use of uninitialized pointer bq->charger
  staging: r8188eu: Fix scheduling while atomic splat
  ASoC: dapm: Fix kcontrol creation for output driver widget
  ...
2016-11-04 14:30:24 +08:00
Alex Shi
a66f9577c6 Merge branch 'linux-linaro-lsk-v4.4' into linux-linaro-lsk-v4.4-android 2016-10-18 12:31:07 +08:00
John Stultz
78c7b55b36 timekeeping: Fix __ktime_get_fast_ns() regression
commit 58bfea9532552d422bde7afa207e1a0f08dffa7d upstream.

In commit 27727df240c7 ("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: 27727df240c7 "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
Christopher S. Hall
9b57d91c03 time: Add cycles to nanoseconds translation
commit 6bd58f09e1d8cc6c50a824c00bf0d617919986a1 upstream.

The timekeeping code does not currently provide a way to translate
externally provided clocksource cycles to system time. The cycle count
is always provided by the result clocksource read() method internal to
the timekeeping code. The added function timekeeping_cycles_to_ns()
calculated a nanosecond value from a cycle count that can be added to
tk_read_base.base value yielding the current system time. This allows
clocksource cycle values external to the timekeeping code to provide a
cycle count that can be transformed to system time.

Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: kevin.b.stanton@intel.com
Cc: kevin.j.clarke@intel.com
Cc: hpa@zytor.com
Cc: jeffrey.t.kirsher@intel.com
Cc: netdev@vger.kernel.org
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Christopher S. Hall <christopher.s.hall@intel.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-16 17:36:14 +02:00
Douglas Anderson
886a7d9ca9 FROMLIST: timers: Fix usleep_range() in the context of wake_up_process()
Users of usleep_range() expect that it will _never_ return in less time
than the minimum passed parameter.  However, nothing in any of the code
ensures this.  Specifically:

usleep_range() => do_usleep_range() => schedule_hrtimeout_range() =>
schedule_hrtimeout_range_clock() just ends up calling schedule() with an
appropriate timeout set using the hrtimer.  If someone else happens to
wake up our task then we'll happily return from usleep_range() early.

msleep() already has code to handle this case since it will loop as long
as there was still time left.  usleep_range() had no such loop.

The problem is is easily demonstrated with a small bit of test code:

  static int usleep_test_task(void *data)
  {
    atomic_t *done = data;
    ktime_t start, end;

    start = ktime_get();
    usleep_range(50000, 100000);
    end = ktime_get();
    pr_info("Requested 50000 - 100000 us.  Actually slept for %llu us\n",
      (unsigned long long)ktime_to_us(ktime_sub(end, start)));
    atomic_set(done, 1);

    return 0;
  }

  static void run_usleep_test(void)
  {
    struct task_struct *t;
    atomic_t done;

    atomic_set(&done, 0);

    t = kthread_run(usleep_test_task, &done, "usleep_test_task");
    while (!atomic_read(&done)) {
      wake_up_process(t);
      udelay(1000);
    }
    kthread_stop(t);
  }

If you run the above code without this patch you get things like:
  Requested 50000 - 100000 us.  Actually slept for 967 us

If you run the above code _with_ this patch, you get:
  Requested 50000 - 100000 us.  Actually slept for 50001 us

Presumably this problem was not detected before because:
- It's not terribly common to use wake_up_process() directly.
- Other ways for processes to wake up are not typically mixed with
  usleep_range().
- There aren't lots of places that use usleep_range(), since many people
  call either msleep() or udelay().

Change-Id: Ibb93ce0dd9fb9688d4a8d10447c098c1dfbd7a1d
Reported-by: Tao Huang <huangtao@rock-chips.com>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Brian Norris <briannorris@chromium.org>
Reviewed-by: Andreas Mohr <andim2@users.sf.net>
(am from https://patchwork.kernel.org/patch/9369963/)
2016-10-12 10:34:40 +08:00
Alex Shi
5f87c475f8 Merge branch 'linux-linaro-lsk-v4.4' into linux-linaro-lsk-v4.4-android
Conflicts:
	in fs/proc/task_mmu.c:
	looks like vma_get_anon_name() want have a name for anonymous
	vma when there is no name used in vma. commit: 586278d78b
	The name show is after any other names, so it maybe covered.
	but anyway, it just a show here.
2016-09-20 15:18:54 +08:00
John Stultz
4eca11dbd2 timekeeping: Avoid taking lock in NMI path with CONFIG_DEBUG_TIMEKEEPING
commit 27727df240c7cc84f2ba6047c6f18d5addfd25ef upstream.

When I added some extra sanity checking in timekeeping_get_ns() under
CONFIG_DEBUG_TIMEKEEPING, I missed that the NMI safe __ktime_get_fast_ns()
method was using timekeeping_get_ns().

Thus the locking added to the debug checks broke the NMI-safety of
__ktime_get_fast_ns().

This patch open-codes the timekeeping_get_ns() logic for
__ktime_get_fast_ns(), so can avoid any deadlocks in NMI.

Fixes: 4ca22c2648 "timekeeping: Add warnings when overflows or underflows are observed"
Reported-by: Steven Rostedt <rostedt@goodmis.org>
Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/1471993702-29148-2-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-15 08:27:52 +02:00
John Stultz
42ef9015e0 timekeeping: Cap array access in timekeeping_debug
commit a4f8f6667f099036c88f231dcad4cf233652c824 upstream.

It was reported that hibernation could fail on the 2nd attempt, where the
system hangs at hibernate() -> syscore_resume() -> i8237A_resume() ->
claim_dma_lock(), because the lock has already been taken.

However there is actually no other process would like to grab this lock on
that problematic platform.

Further investigation showed that the problem is triggered by setting
/sys/power/pm_trace to 1 before the 1st hibernation.

Since once pm_trace is enabled, the rtc becomes unmeaningful after suspend,
and meanwhile some BIOSes would like to adjust the 'invalid' RTC (e.g, smaller
than 1970) to the release date of that motherboard during POST stage, thus
after resumed, it may seem that the system had a significant long sleep time
which is a completely meaningless value.

Then in timekeeping_resume -> tk_debug_account_sleep_time, if the bit31 of the
sleep time happened to be set to 1, fls() returns 32 and we add 1 to
sleep_time_bin[32], which causes an out of bounds array access and therefor
memory being overwritten.

As depicted by System.map:
0xffffffff81c9d080 b sleep_time_bin
0xffffffff81c9d100 B dma_spin_lock
the dma_spin_lock.val is set to 1, which caused this problem.

This patch adds a sanity check in tk_debug_account_sleep_time()
to ensure we don't index past the sleep_time_bin array.

[jstultz: Problem diagnosed and original patch by Chen Yu, I've solved the
 issue slightly differently, but borrowed his excelent explanation of the
 issue here.]

Fixes: 5c83545f24 "power: Add option to log time spent in suspend"
Reported-by: Janek Kozicki <cosurgi@gmail.com>
Reported-by: Chen Yu <yu.c.chen@intel.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: linux-pm@vger.kernel.org
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Xunlei Pang <xpang@redhat.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Zhang Rui <rui.zhang@intel.com>
Link: http://lkml.kernel.org/r/1471993702-29148-3-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-15 08:27:52 +02:00
Vitaly Kuznetsov
a2350f3d82 clocksource: Allow unregistering the watchdog
[ Upstream commit bbf66d897adf2bb0c310db96c97e8db6369f39e1 ]

Hyper-V vmbus module registers TSC page clocksource when loaded. This is
the clocksource with the highest rating and thus it becomes the watchdog
making unloading of the vmbus module impossible.
Separate clocksource_select_watchdog() from clocksource_enqueue_watchdog()
and use it on clocksource register/rating change/unregister.

After all, lobotomized monkeys may need some love too.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Dexuan Cui <decui@microsoft.com>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Link: http://lkml.kernel.org/r/1453483913-25672-1-git-send-email-vkuznets@redhat.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-15 08:27:47 +02:00
John Stultz
1db396648c ntp: Fix ADJ_SETOFFSET being used w/ ADJ_NANO
[ Upstream commit dd4e17ab704269bce71402285f5e8b9ac24b1eff ]

Recently, in commit 37cf4dc3370f I forgot to check if the timeval being passed
was actually a timespec (as is signaled with ADJ_NANO).

This resulted in that patch breaking ADJ_SETOFFSET users who set
ADJ_NANO, by rejecting valid timespecs that were compared with
valid timeval ranges.

This patch addresses this by checking for the ADJ_NANO flag and
using the timepsec check instead in that case.

Reported-by: Harald Hoyer <harald@redhat.com>
Reported-by: Kay Sievers <kay@vrfy.org>
Fixes: 37cf4dc3370f "time: Verify time values in adjtimex ADJ_SETOFFSET to avoid overflow"
Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: David Herrmann <dh.herrmann@gmail.com>
Link: http://lkml.kernel.org/r/1453417415-19110-2-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-15 08:27:47 +02:00
John Stultz
e79e7333c3 time: Verify time values in adjtimex ADJ_SETOFFSET to avoid overflow
[ Upstream commit 37cf4dc3370fbca0344e23bb96446eb2c3548ba7 ]

For adjtimex()'s ADJ_SETOFFSET, make sure the tv_usec value is
sane. We might multiply them later which can cause an overflow
and undefined behavior.

This patch introduces new helper functions to simplify the
checking code and adds comments to clarify

Orginally this patch was by Sasha Levin, but I've basically
rewritten it, so he should get credit for finding the issue
and I should get the blame for any mistakes made since.

Also, credit to Richard Cochran for the phrasing used in the
comment for what is considered valid here.

Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Reported-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-15 08:27:47 +02:00
Marc Zyngier
4fc2942b6e hrtimer: Catch illegal clockids
[ Upstream commit 9006a01829a50cfd6bbd4980910ed46e895e93d7 ]

It is way too easy to take any random clockid and feed it to
the hrtimer subsystem. At best, it gets mapped to a monotonic
base, but it would be better to just catch illegal values as
early as possible.

This patch does exactly that, mapping illegal clockids to an
illegal base index, and panicing when we detect the illegal
condition.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Tomasz Nowicki <tn@semihalf.com>
Cc: Christoffer Dall <christoffer.dall@linaro.org>
Link: http://lkml.kernel.org/r/1452879670-16133-3-git-send-email-marc.zyngier@arm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-15 08:27:44 +02:00