linux-stable.git/kernel, branch v4.10.2

module: fix memory leak on early load_module() failures

2017-03-12T05:44:21+00:00

commit a5544880aff90baf1bd4443ac7ff65182213ffcd upstream.

While looking for early possible module loading failures I was
able to reproduce a memory leak possible with kmemleak. There
are a few rare ways to trigger a failure:

  o we've run into a failure while processing kernel parameters
    (parse_args() returns an error)
  o mod_sysfs_setup() fails
  o we're a live patch module and copy_module_elf() fails

Chances of running into this issue is really low.

kmemleak splat:

unreferenced object 0xffff9f2c4ada1b00 (size 32):
  comm "kworker/u16:4", pid 82, jiffies 4294897636 (age 681.816s)
  hex dump (first 32 bytes):
    6d 65 6d 73 74 69 63 6b 30 00 00 00 00 00 00 00  memstick0.......
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [] kmemleak_alloc+0x4a/0xa0
    [] __kmalloc_track_caller+0x126/0x230
    [] kstrdup+0x31/0x60
    [] kstrdup_const+0x24/0x30
    [] kvasprintf_const+0x7a/0x90
    [] kobject_set_name_vargs+0x21/0x90
    [] dev_set_name+0x47/0x50
    [] memstick_check+0x95/0x33c [memstick]
    [] process_one_work+0x1f3/0x4b0
    [] worker_thread+0x48/0x4e0
    [] kthread+0xc9/0xe0
    [] ret_from_fork+0x1f/0x40
    [] 0xffffffffffffffff

Fixes: e180a6b7759a ("param: fix charp parameters set via sysfs")
Reviewed-by: Miroslav Benes 
Reviewed-by: Aaron Tomlin 
Reviewed-by: Rusty Russell 
Acked-by: Kees Cook 
Signed-off-by: Luis R. Rodriguez 
Signed-off-by: Jessica Yu 
Signed-off-by: Greg Kroah-Hartman

Fix: Disable sys_membarrier when nohz_full is enabled

2017-03-12T05:44:12+00:00

commit 907565337ebf998a68cb5c5b2174ce5e5da065eb upstream.

Userspace applications should be allowed to expect the membarrier system
call with MEMBARRIER_CMD_SHARED command to issue memory barriers on
nohz_full CPUs, but synchronize_sched() does not take those into
account.

Given that we do not want unrelated processes to be able to affect
real-time sensitive nohz_full CPUs, simply return ENOSYS when membarrier
is invoked on a kernel with enabled nohz_full CPUs.

Signed-off-by: Mathieu Desnoyers 
CC: Josh Triplett 
CC: Steven Rostedt 
Signed-off-by: Paul E. McKenney 
Cc: Frederic Weisbecker 
Cc: Chris Metcalf 
Cc: Rik van Riel 
Acked-by: Lai Jiangshan 
Reviewed-by: Josh Triplett 
Signed-off-by: Greg Kroah-Hartman

sigaltstack: support SS_AUTODISARM for CONFIG_COMPAT

2017-03-12T05:44:10+00:00

commit 441398d378f29a5ad6d0fcda07918e54e4961800 upstream.

Currently SS_AUTODISARM is not supported in compatibility mode, but does
not return -EINVAL either.  This makes dosemu built with -m32 on x86_64
to crash.  Also the kernel's sigaltstack selftest fails if compiled with
-m32.

This patch adds the needed support.

Link: http://lkml.kernel.org/r/20170205101213.8163-2-stsp@list.ru
Signed-off-by: Stas Sergeev 
Cc: Milosz Tanski 
Cc: Andy Lutomirski 
Cc: Al Viro 
Cc: Arnd Bergmann 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: Oleg Nesterov 
Cc: Nicolas Pitre 
Cc: Waiman Long 
Cc: Dave Hansen 
Cc: Dmitry Safonov 
Cc: Wang Xiaoqiang 
Cc: Oleg Nesterov 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

mm, devm_memremap_pages: hold device_hotplug lock over mem_hotplug_{begin, done}

2017-03-12T05:44:10+00:00

commit b5d24fda9c3dce51fcb4eee459550a458eaaf1e2 upstream.

The mem_hotplug_{begin,done} lock coordinates with {get,put}_online_mems()
to hold off "readers" of the current state of memory from new hotplug
actions.  mem_hotplug_begin() expects exclusive access, via the
device_hotplug lock, to set mem_hotplug.active_writer.  Calling
mem_hotplug_begin() without locking device_hotplug can lead to
corrupting mem_hotplug.refcount and missed wakeups / soft lockups.

[dan.j.williams@intel.com: v2]
  Link: http://lkml.kernel.org/r/148728203365.38457.17804568297887708345.stgit@dwillia2-desk3.amr.corp.intel.com
Link: http://lkml.kernel.org/r/148693885680.16345.17802627926777862337.stgit@dwillia2-desk3.amr.corp.intel.com
Fixes: f931ab479dd2 ("mm: fix devm_memremap_pages crash, use mem_hotplug_{begin, done}")
Signed-off-by: Dan Williams 
Reported-by: Ben Hutchings 
Cc: Michal Hocko 
Cc: Toshi Kani 
Cc: Vlastimil Babka 
Cc: Logan Gunthorpe 
Cc: Masayoshi Mizuma 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2017-02-19T01:33:17+00:00

Pull locking fix from Thomas Gleixner:
 "Move the futex init function to core initcall so user mode helper does
  not run into an uninitialized futex syscall"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  futex: Move futex_init() to core_initcall

Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2017-02-19T01:30:36+00:00

Pull timer fixes from Thomas Gleixner:
 "Two small fixes::

   - Prevent deadlock on the tick broadcast lock. Found and fixed by
     Mike.

   - Stop using printk() in the timekeeping debug code to prevent a
     deadlock against the scheduler"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  timekeeping: Use deferred printk() in debug code
  tick/broadcast: Prevent deadlock on tick_broadcast_lock

printk: use rcuidle console tracepoint

2017-02-19T01:27:00+00:00

Use rcuidle console tracepoint because, apparently, it may be issued
from an idle CPU:

  hw-breakpoint: Failed to enable monitor mode on CPU 0.
  hw-breakpoint: CPU 0 failed to disable vector catch

  ===============================
  [ ERR: suspicious RCU usage.  ]
  4.10.0-rc8-next-20170215+ #119 Not tainted
  -------------------------------
  ./include/trace/events/printk.h:32 suspicious rcu_dereference_check() usage!

  other info that might help us debug this:

  RCU used illegally from idle CPU!
  rcu_scheduler_active = 2, debug_locks = 0
  RCU used illegally from extended quiescent state!
  2 locks held by swapper/0/0:
   #0:  (cpu_pm_notifier_lock){......}, at: [] cpu_pm_exit+0x10/0x54
   #1:  (console_lock){+.+.+.}, at: [] vprintk_emit+0x264/0x474

  stack backtrace:
  CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.10.0-rc8-next-20170215+ #119
  Hardware name: Generic OMAP4 (Flattened Device Tree)
    console_unlock
    vprintk_emit
    vprintk_default
    printk
    reset_ctrl_regs
    dbg_cpu_pm_notify
    notifier_call_chain
    cpu_pm_exit
    omap_enter_idle_coupled
    cpuidle_enter_state
    cpuidle_enter_state_coupled
    do_idle
    cpu_startup_entry
    start_kernel

This RCU warning, however, is suppressed by lockdep_off() in printk().
lockdep_off() increments the ->lockdep_recursion counter and thus
disables RCU_LOCKDEP_WARN() and debug_lockdep_rcu_enabled(), which want
lockdep to be enabled "current->lockdep_recursion == 0".

Link: http://lkml.kernel.org/r/20170217015932.11898-1-sergey.senozhatsky@gmail.com
Signed-off-by: Sergey Senozhatsky 
Reported-by: Tony Lindgren 
Tested-by: Tony Lindgren 
Acked-by: Paul E. McKenney 
Acked-by: Steven Rostedt (VMware) 
Cc: Petr Mladek 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: Tony Lindgren 
Cc: Russell King 
Cc:  [3.4+]
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Revert "nohz: Fix collision between tick and other hrtimers"

2017-02-16T20:19:18+00:00

This reverts commit 24b91e360ef521a2808771633d76ebc68bd5604b and commit
7bdb59f1ad47 ("tick/nohz: Fix possible missing clock reprog after tick
soft restart") that depends on it,

Pavel reports that it causes occasional boot hangs for him that seem to
depend on just how the machine was booted.  In particular, his machine
hangs at around the PCI fixups of the EHCI USB host controller, but only
hangs from cold boot, not from a warm boot.

Thomas Gleixner suspecs it's a CPU hotplug interaction, particularly
since Pavel also saw suspend/resume issues that seem to be related.
We're reverting for now while trying to figure out the root cause.

Reported-bisected-and-tested-by: Pavel Machek 
Acked-by: Frederic Weisbecker 
Cc: Wanpeng Li 
Cc: Peter Zijlstra 
Cc: Rik van Riel 
Cc: Thomas Gleixner 
Cc: stable@kernel.org  # reverted commits were marked for stable
Signed-off-by: Linus Torvalds

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2017-02-16T16:37:18+00:00

Pull networking fixes from David Miller:

 1) In order to avoid problems in the future, make cgroup bpf overriding
    explicit using BPF_F_ALLOW_OVERRIDE. From Alexei Staovoitov.

 2) LLC sets skb->sk without proper skb->destructor and this explodes,
    fix from Eric Dumazet.

 3) Make sure when we have an ipv4 mapped source address, the
    destination is either also an ipv4 mapped address or
    ipv6_addr_any(). Fix from Jonathan T. Leighton.

 4) Avoid packet loss in fec driver by programming the multicast filter
    more intelligently. From Rui Sousa.

 5) Handle multiple threads invoking fanout_add(), fix from Eric
    Dumazet.

 6) Since we can invoke the TCP input path in process context, without
    BH being disabled, we have to accomodate that in the locking of the
    TCP probe. Also from Eric Dumazet.

 7) Fix erroneous emission of NETEVENT_DELAY_PROBE_TIME_UPDATE when we
    aren't even updating that sysctl value. From Marcus Huewe.

 8) Fix endian bugs in ibmvnic driver, from Thomas Falcon.

[ This is the second version of the pull that reverts the nested
  rhashtable changes that looked a bit too scary for this late in the
  release  - Linus ]

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (27 commits)
  rhashtable: Revert nested table changes.
  ibmvnic: Fix endian errors in error reporting output
  ibmvnic: Fix endian error when requesting device capabilities
  net: neigh: Fix netevent NETEVENT_DELAY_PROBE_TIME_UPDATE notification
  net: xilinx_emaclite: fix freezes due to unordered I/O
  net: xilinx_emaclite: fix receive buffer overflow
  bpf: kernel header files need to be copied into the tools directory
  tcp: tcp_probe: use spin_lock_bh()
  uapi: fix linux/if_pppol2tp.h userspace compilation errors
  packet: fix races in fanout_add()
  ibmvnic: Fix initial MTU settings
  net: ethernet: ti: cpsw: fix cpsw assignment in resume
  kcm: fix a null pointer dereference in kcm_sendmsg()
  net: fec: fix multicast filtering hardware setup
  ipv6: Handle IPv4-mapped src to in6addr_any dst.
  ipv6: Inhibit IPv4-mapped src address on the wire.
  net/mlx5e: Disable preemption when doing TC statistics upcall
  rhashtable: Add nested tables
  tipc: Fix tipc_sk_reinit race conditions
  gfs2: Use rhashtable walk interface in glock_hash_walk
  ...

timekeeping: Use deferred printk() in debug code

2017-02-15T10:46:08+00:00

We cannot do printk() from tk_debug_account_sleep_time(), because
tk_debug_account_sleep_time() is called under tk_core seq lock.
The reason why printk() is unsafe there is that console_sem may
invoke scheduler (up()->wake_up_process()->activate_task()), which,
in turn, can return back to timekeeping code, for instance, via
get_time()->ktime_get(), deadlocking the system on tk_core seq lock.

[   48.950592] ======================================================
[   48.950622] [ INFO: possible circular locking dependency detected ]
[   48.950622] 4.10.0-rc7-next-20170213+ #101 Not tainted
[   48.950622] -------------------------------------------------------
[   48.950622] kworker/0:0/3 is trying to acquire lock:
[   48.950653]  (tk_core){----..}, at: [] retrigger_next_event+0x4c/0x90
[   48.950683]
               but task is already holding lock:
[   48.950683]  (hrtimer_bases.lock){-.-...}, at: [] retrigger_next_event+0x38/0x90
[   48.950714]
               which lock already depends on the new lock.

[   48.950714]
               the existing dependency chain (in reverse order) is:
[   48.950714]
               -> #5 (hrtimer_bases.lock){-.-...}:
[   48.950744]        _raw_spin_lock_irqsave+0x50/0x64
[   48.950775]        lock_hrtimer_base+0x28/0x58
[   48.950775]        hrtimer_start_range_ns+0x20/0x5c8
[   48.950775]        __enqueue_rt_entity+0x320/0x360
[   48.950805]        enqueue_rt_entity+0x2c/0x44
[   48.950805]        enqueue_task_rt+0x24/0x94
[   48.950836]        ttwu_do_activate+0x54/0xc0
[   48.950836]        try_to_wake_up+0x248/0x5c8
[   48.950836]        __setup_irq+0x420/0x5f0
[   48.950836]        request_threaded_irq+0xdc/0x184
[   48.950866]        devm_request_threaded_irq+0x58/0xa4
[   48.950866]        omap_i2c_probe+0x530/0x6a0
[   48.950897]        platform_drv_probe+0x50/0xb0
[   48.950897]        driver_probe_device+0x1f8/0x2cc
[   48.950897]        __driver_attach+0xc0/0xc4
[   48.950927]        bus_for_each_dev+0x6c/0xa0
[   48.950927]        bus_add_driver+0x100/0x210
[   48.950927]        driver_register+0x78/0xf4
[   48.950958]        do_one_initcall+0x3c/0x16c
[   48.950958]        kernel_init_freeable+0x20c/0x2d8
[   48.950958]        kernel_init+0x8/0x110
[   48.950988]        ret_from_fork+0x14/0x24
[   48.950988]
               -> #4 (&rt_b->rt_runtime_lock){-.-...}:
[   48.951019]        _raw_spin_lock+0x40/0x50
[   48.951019]        rq_offline_rt+0x9c/0x2bc
[   48.951019]        set_rq_offline.part.2+0x2c/0x58
[   48.951049]        rq_attach_root+0x134/0x144
[   48.951049]        cpu_attach_domain+0x18c/0x6f4
[   48.951049]        build_sched_domains+0xba4/0xd80
[   48.951080]        sched_init_smp+0x68/0x10c
[   48.951080]        kernel_init_freeable+0x160/0x2d8
[   48.951080]        kernel_init+0x8/0x110
[   48.951080]        ret_from_fork+0x14/0x24
[   48.951110]
               -> #3 (&rq->lock){-.-.-.}:
[   48.951110]        _raw_spin_lock+0x40/0x50
[   48.951141]        task_fork_fair+0x30/0x124
[   48.951141]        sched_fork+0x194/0x2e0
[   48.951141]        copy_process.part.5+0x448/0x1a20
[   48.951171]        _do_fork+0x98/0x7e8
[   48.951171]        kernel_thread+0x2c/0x34
[   48.951171]        rest_init+0x1c/0x18c
[   48.951202]        start_kernel+0x35c/0x3d4
[   48.951202]        0x8000807c
[   48.951202]
               -> #2 (&p->pi_lock){-.-.-.}:
[   48.951232]        _raw_spin_lock_irqsave+0x50/0x64
[   48.951232]        try_to_wake_up+0x30/0x5c8
[   48.951232]        up+0x4c/0x60
[   48.951263]        __up_console_sem+0x2c/0x58
[   48.951263]        console_unlock+0x3b4/0x650
[   48.951263]        vprintk_emit+0x270/0x474
[   48.951293]        vprintk_default+0x20/0x28
[   48.951293]        printk+0x20/0x30
[   48.951324]        kauditd_hold_skb+0x94/0xb8
[   48.951324]        kauditd_thread+0x1a4/0x56c
[   48.951324]        kthread+0x104/0x148
[   48.951354]        ret_from_fork+0x14/0x24
[   48.951354]
               -> #1 ((console_sem).lock){-.....}:
[   48.951385]        _raw_spin_lock_irqsave+0x50/0x64
[   48.951385]        down_trylock+0xc/0x2c
[   48.951385]        __down_trylock_console_sem+0x24/0x80
[   48.951385]        console_trylock+0x10/0x8c
[   48.951416]        vprintk_emit+0x264/0x474
[   48.951416]        vprintk_default+0x20/0x28
[   48.951416]        printk+0x20/0x30
[   48.951446]        tk_debug_account_sleep_time+0x5c/0x70
[   48.951446]        __timekeeping_inject_sleeptime.constprop.3+0x170/0x1a0
[   48.951446]        timekeeping_resume+0x218/0x23c
[   48.951477]        syscore_resume+0x94/0x42c
[   48.951477]        suspend_enter+0x554/0x9b4
[   48.951477]        suspend_devices_and_enter+0xd8/0x4b4
[   48.951507]        enter_state+0x934/0xbd4
[   48.951507]        pm_suspend+0x14/0x70
[   48.951507]        state_store+0x68/0xc8
[   48.951538]        kernfs_fop_write+0xf4/0x1f8
[   48.951538]        __vfs_write+0x1c/0x114
[   48.951538]        vfs_write+0xa0/0x168
[   48.951568]        SyS_write+0x3c/0x90
[   48.951568]        __sys_trace_return+0x0/0x10
[   48.951568]
               -> #0 (tk_core){----..}:
[   48.951599]        lock_acquire+0xe0/0x294
[   48.951599]        ktime_get_update_offsets_now+0x5c/0x1d4
[   48.951629]        retrigger_next_event+0x4c/0x90
[   48.951629]        on_each_cpu+0x40/0x7c
[   48.951629]        clock_was_set_work+0x14/0x20
[   48.951660]        process_one_work+0x2b4/0x808
[   48.951660]        worker_thread+0x3c/0x550
[   48.951660]        kthread+0x104/0x148
[   48.951690]        ret_from_fork+0x14/0x24
[   48.951690]
               other info that might help us debug this:

[   48.951690] Chain exists of:
                 tk_core --> &rt_b->rt_runtime_lock --> hrtimer_bases.lock

[   48.951721]  Possible unsafe locking scenario:

[   48.951721]        CPU0                    CPU1
[   48.951721]        ----                    ----
[   48.951721]   lock(hrtimer_bases.lock);
[   48.951751]                                lock(&rt_b->rt_runtime_lock);
[   48.951751]                                lock(hrtimer_bases.lock);
[   48.951751]   lock(tk_core);
[   48.951782]
                *** DEADLOCK ***

[   48.951782] 3 locks held by kworker/0:0/3:
[   48.951782]  #0:  ("events"){.+.+.+}, at: [] process_one_work+0x1f8/0x808
[   48.951812]  #1:  (hrtimer_work){+.+...}, at: [] process_one_work+0x1f8/0x808
[   48.951843]  #2:  (hrtimer_bases.lock){-.-...}, at: [] retrigger_next_event+0x38/0x90
[   48.951843]   stack backtrace:
[   48.951873] CPU: 0 PID: 3 Comm: kworker/0:0 Not tainted 4.10.0-rc7-next-20170213+
[   48.951904] Workqueue: events clock_was_set_work
[   48.951904] [] (unwind_backtrace) from [] (show_stack+0x10/0x14)
[   48.951934] [] (show_stack) from [] (dump_stack+0xac/0xe0)
[   48.951934] [] (dump_stack) from [] (print_circular_bug+0x1d0/0x308)
[   48.951965] [] (print_circular_bug) from [] (validate_chain+0xf50/0x1324)
[   48.951965] [] (validate_chain) from [] (__lock_acquire+0x468/0x7e8)
[   48.951995] [] (__lock_acquire) from [] (lock_acquire+0xe0/0x294)
[   48.951995] [] (lock_acquire) from [] (ktime_get_update_offsets_now+0x5c/0x1d4)
[   48.952026] [] (ktime_get_update_offsets_now) from [] (retrigger_next_event+0x4c/0x90)
[   48.952026] [] (retrigger_next_event) from [] (on_each_cpu+0x40/0x7c)
[   48.952056] [] (on_each_cpu) from [] (clock_was_set_work+0x14/0x20)
[   48.952056] [] (clock_was_set_work) from [] (process_one_work+0x2b4/0x808)
[   48.952087] [] (process_one_work) from [] (worker_thread+0x3c/0x550)
[   48.952087] [] (worker_thread) from [] (kthread+0x104/0x148)
[   48.952087] [] (kthread) from [] (ret_from_fork+0x14/0x24)

Replace printk() with printk_deferred(), which does not call into
the scheduler.

Fixes: 0bf43f15db85 ("timekeeping: Prints the amounts of time spent during suspend")
Reported-and-tested-by: Tony Lindgren 
Signed-off-by: Sergey Senozhatsky 
Cc: Petr Mladek 
Cc: Sergey Senozhatsky 
Cc: Peter Zijlstra 
Cc: "Rafael J . Wysocki" 
Cc: Steven Rostedt 
Cc: John Stultz 
Cc: "[4.9+]" 
Link: http://lkml.kernel.org/r/20170215044332.30449-1-sergey.senozhatsky@gmail.com
Signed-off-by: Thomas Gleixner