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ceph: Use pseudo-random numbers to choose mds#1

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wip-3579
Apr 12, 2013
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ceph: Use pseudo-random numbers to choose mds#1
6uv1s merged 1 commit intotestingfrom
wip-3579

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@6uv1s 6uv1s commented Apr 12, 2013

We don't need to use up entropy to choose an mds,
so use prandom_u32() to get a pseudo-random number.

Also, we don't need to choose a random mds if only
one mds is available, so add special casing for the
common case.

Fixes http://tracker.ceph.com/issues/3579

Signed-off-by: Sam Lang sam.lang@inktank.com

We don't need to use up entropy to choose an mds,
so use prandom_u32() to get a pseudo-random number.

Also, we don't need to choose a random mds if only
one mds is available, so add special casing for the
common case.

Fixes http://tracker.ceph.com/issues/3579

Signed-off-by: Sam Lang <sam.lang@inktank.com>
@6uv1s 6uv1s merged this pull request into testing Apr 12, 2013
@6uv1s 6uv1s deleted the wip-3579 branch April 12, 2013 18:06
alexelder pushed a commit that referenced this pull request Apr 15, 2013
Commit 84c1754 (ext4: move work from io_end to inode) triggered a
regression when running xfstest #270 when the file system is mounted
with dioread_nolock.

The problem is that after ext4_evict_inode() calls ext4_ioend_wait(),
this guarantees that last io_end structure has been freed, but it does
not guarantee that the workqueue structure, which was moved into the
inode by commit 84c1754, is actually finished.  Once
ext4_flush_completed_IO() calls ext4_free_io_end() on CPU #1, this
will allow ext4_ioend_wait() to return on CPU #2, at which point the
evict_inode() codepath can race against the workqueue code on CPU #1
accessing EXT4_I(inode)->i_unwritten_work to find the next item of
work to do.

Fix this by calling cancel_work_sync() in ext4_ioend_wait(), which
will be renamed ext4_ioend_shutdown(), since it is only used by
ext4_evict_inode().  Also, move the call to ext4_ioend_shutdown()
until after truncate_inode_pages() and filemap_write_and_wait() are
called, to make sure all dirty pages have been written back and
flushed from the page cache first.

BUG: unable to handle kernel NULL pointer dereference at   (null)
IP: [<c01dda6a>] cwq_activate_delayed_work+0x3b/0x7e
*pdpt = 0000000030bc3001 *pde = 0000000000000000 
Oops: 0000 [#1] SMP DEBUG_PAGEALLOC
Modules linked in:
Pid: 6, comm: kworker/u:0 Not tainted 3.8.0-rc3-00013-g84c1754-dirty #91 Bochs Bochs
EIP: 0060:[<c01dda6a>] EFLAGS: 00010046 CPU: 0
EIP is at cwq_activate_delayed_work+0x3b/0x7e
EAX: 00000000 EBX: 00000000 ECX: f505fe54 EDX: 00000000
ESI: ed5b697c EDI: 00000006 EBP: f64b7e8c ESP: f64b7e84
 DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068
CR0: 8005003b CR2: 00000000 CR3: 30bc2000 CR4: 000006f0
DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
DR6: ffff0ff0 DR7: 00000400
Process kworker/u:0 (pid: 6, ti=f64b6000 task=f64b4160 task.ti=f64b6000)
Stack:
 f505fe00 00000006 f64b7e9c c01de3d7 f6435540 00000003 f64b7efc c01def1d
 f6435540 00000002 00000000 0000008a c16d0808 c040a10b c16d07d8 c16d08b0
 f505fe00 c16d0780 00000000 00000000 ee153df4 c1ce4a30 c17d0e30 00000000
Call Trace:
 [<c01de3d7>] cwq_dec_nr_in_flight+0x71/0xfb
 [<c01def1d>] process_one_work+0x5d8/0x637
 [<c040a10b>] ? ext4_end_bio+0x300/0x300
 [<c01e3105>] worker_thread+0x249/0x3ef
 [<c01ea317>] kthread+0xd8/0xeb
 [<c01e2ebc>] ? manage_workers+0x4bb/0x4bb
 [<c023a370>] ? trace_hardirqs_on+0x27/0x37
 [<c0f1b4b7>] ret_from_kernel_thread+0x1b/0x28
 [<c01ea23f>] ? __init_kthread_worker+0x71/0x71
Code: 01 83 15 ac ff 6c c1 00 31 db 89 c6 8b 00 a8 04 74 12 89 c3 30 db 83 05 b0 ff 6c c1 01 83 15 b4 ff 6c c1 00 89 f0 e8 42 ff ff ff <8b> 13 89 f0 83 05 b8 ff 6c c1
 6c c1 00 31 c9 83
EIP: [<c01dda6a>] cwq_activate_delayed_work+0x3b/0x7e SS:ESP 0068:f64b7e84
CR2: 0000000000000000
---[ end trace a1923229da53d8a4 ]---

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Jan Kara <jack@suse.cz>
alexelder pushed a commit that referenced this pull request Apr 15, 2013
With git commit c705c78
"acpi: Export the acpi_processor_get_performance_info" we are now
using a different mechanism to access the P-states.

The acpi_processor per-cpu structure is set and filtered by the
core ACPI code which shrinks the per_cpu contents to only online CPUs.
In the past we would call acpi_processor_register_performance()
which would have not tried to dereference offline cpus.

With the new patch and the fact that the loop we take is for
for_all_possible_cpus we end up crashing on some machines.
We could modify the loop to be for online_cpus - but all the other
loops in the code use possible_cpus (for a good reason) - so lets
leave it as so and just check if per_cpu(processor) is NULL.

With this patch we will bypass the !online but possible CPUs.
This fixes:

IP: [<ffffffffa00d13b5>] xen_acpi_processor_init+0x1b6/0xe01 [xen_acpi_processor]
PGD 4126e6067 PUD 4126e3067 PMD 0
Oops: 0002 [#1] SMP
Pid: 432, comm: modprobe Not tainted 3.9.0-rc3+ #28 To be filled by O.E.M. To be filled by O.E.M./M5A97
RIP: e030:[<ffffffffa00d13b5>]  [<ffffffffa00d13b5>] xen_acpi_processor_init+0x1b6/0xe01 [xen_acpi_processor]
RSP: e02b:ffff88040c8a3ce8  EFLAGS: 00010282
.. snip..
Call Trace:
 [<ffffffffa00d11ff>] ? read_acpi_id+0x12b/0x12b [xen_acpi_processor]
 [<ffffffff8100215a>] do_one_initcall+0x12a/0x180
 [<ffffffff810c42c3>] load_module+0x1cd3/0x2870
 [<ffffffff81319b70>] ? ddebug_proc_open+0xc0/0xc0
 [<ffffffff810c4f37>] sys_init_module+0xd7/0x120
 [<ffffffff8166ce19>] system_call_fastpath+0x16/0x1b

on some machines.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
alexelder pushed a commit that referenced this pull request Apr 15, 2013
Booting with 32 TBytes memory hits BUG at mm/page_alloc.c:552! (output
below).

The key hint is "page 4294967296 outside zone".
4294967296 = 0x100000000 (bit 32 is set).

The problem is in include/linux/mmzone.h:

  530 static inline unsigned zone_end_pfn(const struct zone *zone)
  531 {
  532         return zone->zone_start_pfn + zone->spanned_pages;
  533 }

zone_end_pfn is "unsigned" (32 bits).  Changing it to "unsigned long"
(64 bits) fixes the problem.

zone_end_pfn() was added recently in commit 108bcc9 ("mm: add & use
zone_end_pfn() and zone_spans_pfn()")

Output from the failure.

  No AGP bridge found
  page 4294967296 outside zone [ 4294967296 - 4327469056 ]
  ------------[ cut here ]------------
  kernel BUG at mm/page_alloc.c:552!
  invalid opcode: 0000 [#1] SMP
  Modules linked in:
  CPU 0
  Pid: 0, comm: swapper Not tainted 3.9.0-rc2.dtp+ #10
  RIP: free_one_page+0x382/0x430
  Process swapper (pid: 0, threadinfo ffffffff81942000, task ffffffff81955420)
  Call Trace:
    __free_pages_ok+0x96/0xb0
    __free_pages+0x25/0x50
    __free_pages_bootmem+0x8a/0x8c
    __free_memory_core+0xea/0x131
    free_low_memory_core_early+0x4a/0x98
    free_all_bootmem+0x45/0x47
    mem_init+0x7b/0x14c
    start_kernel+0x216/0x433
    x86_64_start_reservations+0x2a/0x2c
    x86_64_start_kernel+0x144/0x153
  Code: 89 f1 ba 01 00 00 00 31 f6 d3 e2 4c 89 ef e8 66 a4 01 00 e9 2c fe ff ff 0f 0b eb fe 0f 0b 66 66 2e 0f 1f 84 00 00 00 00 00 eb f3 <0f> 0b eb fe 0f 0b 0f 1f 84 00 00 00 00 00 eb f6 0f 0b eb fe 49

Signed-off-by: Russ Anderson <rja@sgi.com>
Reported-by: George Beshers <gbeshers@sgi.com>
Acked-by: Hedi Berriche <hedi@sgi.com>
Cc: Cody P Schafer <cody@linux.vnet.ibm.com>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
alexelder pushed a commit that referenced this pull request Apr 15, 2013
We can deadlock (s_active and fcoe_config_mutex) if a
port is being destroyed at the same time one is being created.

[ 4200.503113] ======================================================
[ 4200.503114] [ INFO: possible circular locking dependency detected ]
[ 4200.503116] 3.8.0-rc5+ #8 Not tainted
[ 4200.503117] -------------------------------------------------------
[ 4200.503118] kworker/3:2/2492 is trying to acquire lock:
[ 4200.503119]  (s_active#292){++++.+}, at: [<ffffffff8122d20b>] sysfs_addrm_finish+0x3b/0x70
[ 4200.503127]
but task is already holding lock:
[ 4200.503128]  (fcoe_config_mutex){+.+.+.}, at: [<ffffffffa02f3338>] fcoe_destroy_work+0xe8/0x120 [fcoe]
[ 4200.503133]
which lock already depends on the new lock.

[ 4200.503135]
the existing dependency chain (in reverse order) is:
[ 4200.503136]
-> #1 (fcoe_config_mutex){+.+.+.}:
[ 4200.503139]        [<ffffffff810c7711>] lock_acquire+0xa1/0x140
[ 4200.503143]        [<ffffffff816ca7be>] mutex_lock_nested+0x6e/0x360
[ 4200.503146]        [<ffffffffa02f11bd>] fcoe_enable+0x1d/0xb0 [fcoe]
[ 4200.503148]        [<ffffffffa02f127d>] fcoe_ctlr_enabled+0x2d/0x50 [fcoe]
[ 4200.503151]        [<ffffffffa02ffbe8>] store_ctlr_enabled+0x38/0x90 [libfcoe]
[ 4200.503154]        [<ffffffff81424878>] dev_attr_store+0x18/0x30
[ 4200.503157]        [<ffffffff8122b750>] sysfs_write_file+0xe0/0x150
[ 4200.503160]        [<ffffffff811b334c>] vfs_write+0xac/0x180
[ 4200.503162]        [<ffffffff811b3692>] sys_write+0x52/0xa0
[ 4200.503164]        [<ffffffff816d7159>] system_call_fastpath+0x16/0x1b
[ 4200.503167]
-> #0 (s_active#292){++++.+}:
[ 4200.503170]        [<ffffffff810c680f>] __lock_acquire+0x135f/0x1c90
[ 4200.503172]        [<ffffffff810c7711>] lock_acquire+0xa1/0x140
[ 4200.503174]        [<ffffffff8122c626>] sysfs_deactivate+0x116/0x160
[ 4200.503176]        [<ffffffff8122d20b>] sysfs_addrm_finish+0x3b/0x70
[ 4200.503178]        [<ffffffff8122b2eb>] sysfs_hash_and_remove+0x5b/0xb0
[ 4200.503180]        [<ffffffff8122f3d1>] sysfs_remove_group+0x61/0x100
[ 4200.503183]        [<ffffffff814251eb>] device_remove_groups+0x3b/0x60
[ 4200.503185]        [<ffffffff81425534>] device_remove_attrs+0x44/0x80
[ 4200.503187]        [<ffffffff81425e97>] device_del+0x127/0x1c0
[ 4200.503189]        [<ffffffff81425f52>] device_unregister+0x22/0x60
[ 4200.503191]        [<ffffffffa0300970>] fcoe_ctlr_device_delete+0xe0/0xf0 [libfcoe]
[ 4200.503194]        [<ffffffffa02f1b5c>] fcoe_interface_cleanup+0x6c/0xa0 [fcoe]
[ 4200.503196]        [<ffffffffa02f3355>] fcoe_destroy_work+0x105/0x120 [fcoe]
[ 4200.503198]        [<ffffffff8107ee91>] process_one_work+0x1a1/0x580
[ 4200.503203]        [<ffffffff81080c6e>] worker_thread+0x15e/0x440
[ 4200.503205]        [<ffffffff8108715a>] kthread+0xea/0xf0
[ 4200.503207]        [<ffffffff816d70ac>] ret_from_fork+0x7c/0xb0

[ 4200.503209]
other info that might help us debug this:

[ 4200.503211]  Possible unsafe locking scenario:

[ 4200.503212]        CPU0                    CPU1
[ 4200.503213]        ----                    ----
[ 4200.503214]   lock(fcoe_config_mutex);
[ 4200.503215]                                lock(s_active#292);
[ 4200.503218]                                lock(fcoe_config_mutex);
[ 4200.503219]   lock(s_active#292);
[ 4200.503221]
 *** DEADLOCK ***

[ 4200.503223] 3 locks held by kworker/3:2/2492:
[ 4200.503224]  #0:  (fcoe){.+.+.+}, at: [<ffffffff8107ee2b>] process_one_work+0x13b/0x580
[ 4200.503228]  #1:  ((&port->destroy_work)){+.+.+.}, at: [<ffffffff8107ee2b>] process_one_work+0x13b/0x580
[ 4200.503232]  #2:  (fcoe_config_mutex){+.+.+.}, at: [<ffffffffa02f3338>] fcoe_destroy_work+0xe8/0x120 [fcoe]
[ 4200.503236]
stack backtrace:
[ 4200.503238] Pid: 2492, comm: kworker/3:2 Not tainted 3.8.0-rc5+ #8
[ 4200.503240] Call Trace:
[ 4200.503243]  [<ffffffff816c2f09>] print_circular_bug+0x1fb/0x20c
[ 4200.503246]  [<ffffffff810c680f>] __lock_acquire+0x135f/0x1c90
[ 4200.503248]  [<ffffffff810c463a>] ? debug_check_no_locks_freed+0x9a/0x180
[ 4200.503250]  [<ffffffff810c7711>] lock_acquire+0xa1/0x140
[ 4200.503253]  [<ffffffff8122d20b>] ? sysfs_addrm_finish+0x3b/0x70
[ 4200.503255]  [<ffffffff8122c626>] sysfs_deactivate+0x116/0x160
[ 4200.503258]  [<ffffffff8122d20b>] ? sysfs_addrm_finish+0x3b/0x70
[ 4200.503260]  [<ffffffff8122d20b>] sysfs_addrm_finish+0x3b/0x70
[ 4200.503262]  [<ffffffff8122b2eb>] sysfs_hash_and_remove+0x5b/0xb0
[ 4200.503265]  [<ffffffff8122f3d1>] sysfs_remove_group+0x61/0x100
[ 4200.503273]  [<ffffffff814251eb>] device_remove_groups+0x3b/0x60
[ 4200.503275]  [<ffffffff81425534>] device_remove_attrs+0x44/0x80
[ 4200.503277]  [<ffffffff81425e97>] device_del+0x127/0x1c0
[ 4200.503279]  [<ffffffff81425f52>] device_unregister+0x22/0x60
[ 4200.503282]  [<ffffffffa0300970>] fcoe_ctlr_device_delete+0xe0/0xf0 [libfcoe]
[ 4200.503285]  [<ffffffffa02f1b5c>] fcoe_interface_cleanup+0x6c/0xa0 [fcoe]
[ 4200.503287]  [<ffffffffa02f3355>] fcoe_destroy_work+0x105/0x120 [fcoe]
[ 4200.503290]  [<ffffffff8107ee91>] process_one_work+0x1a1/0x580
[ 4200.503292]  [<ffffffff8107ee2b>] ? process_one_work+0x13b/0x580
[ 4200.503295]  [<ffffffffa02f3250>] ? fcoe_if_destroy+0x230/0x230 [fcoe]
[ 4200.503297]  [<ffffffff81080c6e>] worker_thread+0x15e/0x440
[ 4200.503299]  [<ffffffff81080b10>] ? busy_worker_rebind_fn+0x100/0x100
[ 4200.503301]  [<ffffffff8108715a>] kthread+0xea/0xf0
[ 4200.503304]  [<ffffffff81087070>] ? kthread_create_on_node+0x160/0x160
[ 4200.503306]  [<ffffffff816d70ac>] ret_from_fork+0x7c/0xb0
[ 4200.503308]  [<ffffffff81087070>] ? kthread_create_on_node+0x160/0x160

Signed-off-by: Robert Love <robert.w.love@intel.com>
Tested-by: Jack Morgan <jack.morgan@intel.com>
alexelder pushed a commit that referenced this pull request Apr 15, 2013
The current code makes the assumption that a cpu_base lock won't be
held if the CPU corresponding to that cpu_base is offline, which isn't
always true.

If a hrtimer is not queued, then it will not be migrated by
migrate_hrtimers() when a CPU is offlined. Therefore, the hrtimer's
cpu_base may still point to a CPU which has subsequently gone offline
if the timer wasn't enqueued at the time the CPU went down.

Normally this wouldn't be a problem, but a cpu_base's lock is blindly
reinitialized each time a CPU is brought up. If a CPU is brought
online during the period that another thread is performing a hrtimer
operation on a stale hrtimer, then the lock will be reinitialized
under its feet, and a SPIN_BUG() like the following will be observed:

<0>[   28.082085] BUG: spinlock already unlocked on CPU#0, swapper/0/0
<0>[   28.087078]  lock: 0xc4780b40, value 0x0 .magic: dead4ead, .owner: <none>/-1, .owner_cpu: -1
<4>[   42.451150] [<c0014398>] (unwind_backtrace+0x0/0x120) from [<c0269220>] (do_raw_spin_unlock+0x44/0xdc)
<4>[   42.460430] [<c0269220>] (do_raw_spin_unlock+0x44/0xdc) from [<c071b5bc>] (_raw_spin_unlock+0x8/0x30)
<4>[   42.469632] [<c071b5bc>] (_raw_spin_unlock+0x8/0x30) from [<c00a9ce0>] (__hrtimer_start_range_ns+0x1e4/0x4f8)
<4>[   42.479521] [<c00a9ce0>] (__hrtimer_start_range_ns+0x1e4/0x4f8) from [<c00aa014>] (hrtimer_start+0x20/0x28)
<4>[   42.489247] [<c00aa014>] (hrtimer_start+0x20/0x28) from [<c00e6190>] (rcu_idle_enter_common+0x1ac/0x320)
<4>[   42.498709] [<c00e6190>] (rcu_idle_enter_common+0x1ac/0x320) from [<c00e6440>] (rcu_idle_enter+0xa0/0xb8)
<4>[   42.508259] [<c00e6440>] (rcu_idle_enter+0xa0/0xb8) from [<c000f268>] (cpu_idle+0x24/0xf0)
<4>[   42.516503] [<c000f268>] (cpu_idle+0x24/0xf0) from [<c06ed3c0>] (rest_init+0x88/0xa0)
<4>[   42.524319] [<c06ed3c0>] (rest_init+0x88/0xa0) from [<c0c00978>] (start_kernel+0x3d0/0x434)

As an example, this particular crash occurred when hrtimer_start() was
executed on CPU #0. The code locked the hrtimer's current cpu_base
corresponding to CPU #1. CPU #0 then tried to switch the hrtimer's
cpu_base to an optimal CPU which was online. In this case, it selected
the cpu_base corresponding to CPU #3.

Before it could proceed, CPU #1 came online and reinitialized the
spinlock corresponding to its cpu_base. Thus now CPU #0 held a lock
which was reinitialized. When CPU #0 finally ended up unlocking the
old cpu_base corresponding to CPU #1 so that it could switch to CPU
#3, we hit this SPIN_BUG() above while in switch_hrtimer_base().

CPU #0                            CPU #1
----                              ----
...                               <offline>
hrtimer_start()
lock_hrtimer_base(base #1)
...                               init_hrtimers_cpu()
switch_hrtimer_base()             ...
...                               raw_spin_lock_init(&cpu_base->lock)
raw_spin_unlock(&cpu_base->lock)  ...
<spin_bug>

Solve this by statically initializing the lock.

Signed-off-by: Michael Bohan <mbohan@codeaurora.org>
Link: http://lkml.kernel.org/r/1363745965-23475-1-git-send-email-mbohan@codeaurora.org
Cc: stable@vger.kernel.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
alexelder pushed a commit that referenced this pull request Apr 15, 2013
clk inits on OMAP happen quite early, even before slab is available.
The dependency comes from the fact that the timer init code starts to
use clocks and hwmod and we need clocks to be initialized by then.

There are various problems doing clk inits this early, one is,
not being able to do dynamic clk registrations and hence the
dependency on clk-private.h. The other is, inability to debug
early kernel crashes without enabling DEBUG_LL and earlyprintk.

Doing early clk init also exposed another instance of a kernel
panic due to a BUG() when CONFIG_DEBUG_SLAB is enabled.

[    0.000000] Kernel BUG at c01174f8 [verbose debug info unavailable]
[    0.000000] Internal error: Oops - BUG: 0 [#1] SMP ARM
[    0.000000] Modules linked in:
[    0.000000] CPU: 0    Not tainted  (3.9.0-rc1-12179-g72d48f9 #6)
[    0.000000] PC is at __kmalloc+0x1d4/0x248
[    0.000000] LR is at __clk_init+0x2e0/0x364
[    0.000000] pc : [<c01174f8>]    lr : [<c0441f54>]    psr: 600001d3
[    0.000000] sp : c076ff28  ip : c065cefc  fp : c0441f54
[    0.000000] r10: 0000001c  r9 : 000080d0  r8 : c076ffd4
[    0.000000] r7 : c074b578  r6 : c0794d88  r5 : 00000040  r4 : 00000000
[    0.000000] r3 : 00000000  r2 : c07cac70  r1 : 000080d0  r0 : 0000001c
[    0.000000] Flags: nZCv  IRQs off  FIQs off  Mode SVC_32  ISA ARM  Segment kernel
[    0.000000] Control: 10c53c7d  Table: 8000404a  DAC: 00000017
[    0.000000] Process swapper (pid: 0, stack limit = 0xc076e240)
[    0.000000] Stack: (0xc076ff28 to 0xc0770000)
[    0.000000] ff20:                   22222222 c0794ec8 c06546e8 00000000 00000040 c0794d88
[    0.000000] ff40: c074b578 c076ffd4 c07951c8 c076e000 00000000 c0441f54 c074b578 c076ffd4
[    0.000000] ff60: c0793828 00000040 c0794d88 c074b578 c076ffd4 c0776900 c076e000 c07272ac
[    0.000000] ff80: 2f800000 c074c968 c07f93d0 c0719780 c076ffa0 c076ff98 00000000 00000000
[    0.000000] ffa0: 00000000 00000000 00000000 00000001 c074cd6c c077b1ec 8000406a c0715724
[    0.000000] ffc0: 00000000 00000000 00000000 00000000 00000000 c074c968 10c53c7d c0776974
[    0.000000] ffe0: c074cd6c c077b1ec 8000406a 411fc092 00000000 80008074 00000000 00000000
[    0.000000] [<c01174f8>] (__kmalloc+0x1d4/0x248) from [<c0441f54>] (__clk_init+0x2e0/0x364)
[    0.000000] [<c0441f54>] (__clk_init+0x2e0/0x364) from [<c07272ac>] (omap4xxx_clk_init+0xbc/0x140)
[    0.000000] [<c07272ac>] (omap4xxx_clk_init+0xbc/0x140) from [<c0719780>] (setup_arch+0x15c/0x284)
[    0.000000] [<c0719780>] (setup_arch+0x15c/0x284) from [<c0715724>] (start_kernel+0x7c/0x334)
[    0.000000] [<c0715724>] (start_kernel+0x7c/0x334) from [<80008074>] (0x80008074)
[    0.000000] Code: e5883004 e1a00006 e28dd00c e8bd8ff0 (e7f001f2)
[    0.000000] ---[ end trace 1b75b31a2719ed1c ]---
[    0.000000] Kernel panic - not syncing: Attempted to kill the idle task!

It was a know issue, that slab allocations would fail when common
clock core tries to cache parent pointers for mux clocks on OMAP,
and hence a patch 'clk: Allow late cache allocation for clk->parents,
commit 7975059' was added to work this problem around.
A BUG() within kmalloc() with CONFIG_DEBUG_SLAB enabled was completely
overlooked causing this regression.

More details on the issue reported can be found here,
http://www.mail-archive.com/linux-omap@vger.kernel.org/msg85932.html

With all these issues around clk inits happening way too early, it
makes sense to at least move them to a point where dynamic memory
allocations are possible. So move them to a point just before the
timer code starts using clocks and hwmod.

This should at least pave way for clk inits on OMAP moving to dynamic
clock registrations instead of using the static macros defined in
clk-private.h.

The issue with kernel panic while CONFIG_DEBUG_SLAB is enabled
was reported by Piotr Haber and Tony Lindgren and this patch
fixes the reported issue as well.

Reported-by: Piotr Haber <phaber@broadcom.com>
Reported-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Rajendra Nayak <rnayak@ti.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Reviewed-by: Mike Turquette <mturquette@linaro.org>
Acked-by: Paul Walmsley <paul@pwsan.com>
Cc: stable@vger.kernel.org  # v3.8
Signed-off-by: Tony Lindgren <tony@atomide.com>
alexelder pushed a commit that referenced this pull request Apr 15, 2013
The following issue was reported.

WARNING: at net/mac80211/util.c:599 ieee80211_can_queue_work.isra.7+0x32/0x40 [mac80211]()
Hardware name: iMac12,1
queueing ieee80211 work while going to suspend
Pid: 0, comm: swapper/0 Tainted: PF          O 3.8.2-206.fc18.x86_64 #1
Call Trace: Mar 16 09:39:17 Parags-iMac kernel: [ 3993.642992]  <IRQ>
[<ffffffff8105e61f>] warn_slowpath_common+0x7f/0xc0
[<ffffffffa0581420>] ? ath_start_rx_poll+0x70/0x70 [ath9k]
<ffffffff8105e716>] warn_slowpath_fmt+0x46/0x50
[<ffffffffa045b542>] ieee80211_can_queue_work.isra.7+0x32/0x40

Fix this by avoiding to queue the work if our device has
already been marked as suspended or stopped.

Reported-by: Parag Warudkar <parag.lkml@gmail.com>
Tested-by: Parag Warudkar <parag.lkml@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@do-not-panic.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
alexelder pushed a commit that referenced this pull request Apr 15, 2013
Op 23-03-13 12:47, Peter Hurley schreef:
> On Tue, 2013-03-19 at 11:13 -0400, Peter Hurley wrote:
>> On vanilla 3.9.0-rc3, I get this 100% repeatable oops after login when
>> the user X session is coming up:
> Perhaps I wasn't clear that this happens on every boot and is a
> regression from 3.8
>
> I'd be happy to help resolve this but time is of the essence; it would
> be a shame to have to revert all of this for 3.9

Well it broke on my system too, so it was easy to fix.

I didn't even need gdm to trigger it!

>8----
This fixes regression caused by 1d7c71a (drm/nouveau/disp: port vblank handling to event interface),

which causes a oops in the following way:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000001
IP: [<0000000000000001>] 0x0
PGD 0
Oops: 0010 [#1] PREEMPT SMP
Modules linked in: ip6table_filter ip6_tables ebtable_nat ebtables ...<snip>...
CPU 3
Pid: 0, comm: swapper/3 Not tainted 3.9.0-rc3-xeon #rc3 Dell Inc. Precision WorkStation T5400  /0RW203
RIP: 0010:[<0000000000000001>]  [<0000000000000001>] 0x0
RSP: 0018:ffff8802afcc3d80  EFLAGS: 00010087
RAX: ffff88029f6e5808 RBX: 0000000000000001 RCX: 0000000000000000
RDX: 0000000000000096 RSI: 0000000000000001 RDI: ffff88029f6e5808
RBP: ffff8802afcc3dc8 R08: 0000000000000000 R09: 0000000000000004
R10: 000000000000002c R11: ffff88029e559a98 R12: ffff8802a376cb78
R13: ffff88029f6e57e0 R14: ffff88029f6e57f8 R15: ffff88029f6e5808
FS:  0000000000000000(0000) GS:ffff8802afcc0000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 0000000000000001 CR3: 000000029fa67000 CR4: 00000000000007e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process swapper/3 (pid: 0, threadinfo ffff8802a355e000, task ffff8802a3535c40)
Stack:
 ffffffffa0159d8a 0000000000000082 ffff88029f6e5820 0000000000000001
 ffff88029f71aa00 0000000000000000 0000000000000000 0000000004000000
 0000000004000000 ffff8802afcc3e38 ffffffffa01843b5 ffff8802afcc3df8
Call Trace:
 <IRQ>
 [<ffffffffa0159d8a>] ? nouveau_event_trigger+0xaa/0xe0 [nouveau]
 [<ffffffffa01843b5>] nv50_disp_intr+0xc5/0x200 [nouveau]
 [<ffffffff816fbacc>] ? _raw_spin_unlock_irqrestore+0x2c/0x50
 [<ffffffff816ff98d>] ? notifier_call_chain+0x4d/0x70
 [<ffffffffa017a105>] nouveau_mc_intr+0xb5/0x110 [nouveau]
 [<ffffffffa01d45ff>] nouveau_irq_handler+0x6f/0x80 [nouveau]
 [<ffffffff810eec95>] handle_irq_event_percpu+0x75/0x260
 [<ffffffff810eeec8>] handle_irq_event+0x48/0x70
 [<ffffffff810f205a>] handle_fasteoi_irq+0x5a/0x100
 [<ffffffff810182f2>] handle_irq+0x22/0x40
 [<ffffffff8170561a>] do_IRQ+0x5a/0xd0
 [<ffffffff816fc2ad>] common_interrupt+0x6d/0x6d
 <EOI>
 [<ffffffff810449b6>] ? native_safe_halt+0x6/0x10
 [<ffffffff8101ea1d>] default_idle+0x3d/0x170
 [<ffffffff8101f736>] cpu_idle+0x116/0x130
 [<ffffffff816e2a06>] start_secondary+0x251/0x258
Code:  Bad RIP value.
RIP  [<0000000000000001>] 0x0
 RSP <ffff8802afcc3d80>
CR2: 0000000000000001
---[ end trace 907323cb8ce6f301 ]---

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
alexelder pushed a commit that referenced this pull request Apr 15, 2013
This reverts commit 6aa9707.

Commit 6aa9707 ("lockdep: check that no locks held at freeze time")
causes problems with NFS root filesystems.  The failures were noticed on
OMAP2 and 3 boards during kernel init:

  [ BUG: swapper/0/1 still has locks held! ]
  3.9.0-rc3-00344-ga937536 #1 Not tainted
  -------------------------------------
  1 lock held by swapper/0/1:
   #0:  (&type->s_umount_key#13/1){+.+.+.}, at: [<c011e84c>] sget+0x248/0x574

  stack backtrace:
    rpc_wait_bit_killable
    __wait_on_bit
    out_of_line_wait_on_bit
    __rpc_execute
    rpc_run_task
    rpc_call_sync
    nfs_proc_get_root
    nfs_get_root
    nfs_fs_mount_common
    nfs_try_mount
    nfs_fs_mount
    mount_fs
    vfs_kern_mount
    do_mount
    sys_mount
    do_mount_root
    mount_root
    prepare_namespace
    kernel_init_freeable
    kernel_init

Although the rootfs mounts, the system is unstable.  Here's a transcript
from a PM test:

  http://www.pwsan.com/omap/testlogs/test_v3.9-rc3/20130317194234/pm/37xxevm/37xxevm_log.txt

Here's what the test log should look like:

  http://www.pwsan.com/omap/testlogs/test_v3.8/20130218214403/pm/37xxevm/37xxevm_log.txt

Mailing list discussion is here:

  http://lkml.org/lkml/2013/3/4/221

Deal with this for v3.9 by reverting the problem commit, until folks can
figure out the right long-term course of action.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Mandeep Singh Baines <msb@chromium.org>
Cc: Jeff Layton <jlayton@redhat.com>
Cc: Shawn Guo <shawn.guo@linaro.org>
Cc: <maciej.rutecki@gmail.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ben Chan <benchan@chromium.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
alexelder pushed a commit that referenced this pull request Apr 15, 2013
Commit b81ea1b (PM / QoS: Fix concurrency issues and memory leaks in
device PM QoS) put calls to pm_qos_sysfs_add_latency(),
pm_qos_sysfs_add_flags(), pm_qos_sysfs_remove_latency(), and
pm_qos_sysfs_remove_flags() under dev_pm_qos_mtx, which was a
mistake, because it may lead to deadlocks in some situations.
For example, if pm_qos_remote_wakeup_store() is run in parallel
with dev_pm_qos_constraints_destroy(), they may deadlock in the
following way:

 ======================================================
 [ INFO: possible circular locking dependency detected ]
 3.9.0-rc4-next-20130328-sasha-00014-g91a3267 #319 Tainted: G        W
 -------------------------------------------------------
 trinity-child6/12371 is trying to acquire lock:
  (s_active#54){++++.+}, at: [<ffffffff81301631>] sysfs_addrm_finish+0x31/0x60

 but task is already holding lock:
  (dev_pm_qos_mtx){+.+.+.}, at: [<ffffffff81f07cc3>] dev_pm_qos_constraints_destroy+0x23/0x250

 which lock already depends on the new lock.

 the existing dependency chain (in reverse order) is:

 -> #1 (dev_pm_qos_mtx){+.+.+.}:
        [<ffffffff811811da>] lock_acquire+0x1aa/0x240
        [<ffffffff83dab809>] __mutex_lock_common+0x59/0x5e0
        [<ffffffff83dabebf>] mutex_lock_nested+0x3f/0x50
        [<ffffffff81f07f2f>] dev_pm_qos_update_flags+0x3f/0xc0
        [<ffffffff81f05f4f>] pm_qos_remote_wakeup_store+0x3f/0x70
        [<ffffffff81efbb43>] dev_attr_store+0x13/0x20
        [<ffffffff812ffdaa>] sysfs_write_file+0xfa/0x150
        [<ffffffff8127f2c1>] __kernel_write+0x81/0x150
        [<ffffffff812afc2d>] write_pipe_buf+0x4d/0x80
        [<ffffffff812af57c>] splice_from_pipe_feed+0x7c/0x120
        [<ffffffff812afa25>] __splice_from_pipe+0x45/0x80
        [<ffffffff812b14fc>] splice_from_pipe+0x4c/0x70
        [<ffffffff812b1538>] default_file_splice_write+0x18/0x30
        [<ffffffff812afae3>] do_splice_from+0x83/0xb0
        [<ffffffff812afb2e>] direct_splice_actor+0x1e/0x20
        [<ffffffff812b0277>] splice_direct_to_actor+0xe7/0x200
        [<ffffffff812b15bc>] do_splice_direct+0x4c/0x70
        [<ffffffff8127eda9>] do_sendfile+0x169/0x300
        [<ffffffff8127ff94>] SyS_sendfile64+0x64/0xb0
        [<ffffffff83db7d18>] tracesys+0xe1/0xe6

 -> #0 (s_active#54){++++.+}:
        [<ffffffff811800cf>] __lock_acquire+0x15bf/0x1e50
        [<ffffffff811811da>] lock_acquire+0x1aa/0x240
        [<ffffffff81300aa2>] sysfs_deactivate+0x122/0x1a0
        [<ffffffff81301631>] sysfs_addrm_finish+0x31/0x60
        [<ffffffff812ff77f>] sysfs_hash_and_remove+0x7f/0xb0
        [<ffffffff813035a1>] sysfs_unmerge_group+0x51/0x70
        [<ffffffff81f068f4>] pm_qos_sysfs_remove_flags+0x14/0x20
        [<ffffffff81f07490>] __dev_pm_qos_hide_flags+0x30/0x70
        [<ffffffff81f07cd5>] dev_pm_qos_constraints_destroy+0x35/0x250
        [<ffffffff81f06931>] dpm_sysfs_remove+0x11/0x50
        [<ffffffff81efcf6f>] device_del+0x3f/0x1b0
        [<ffffffff81efd128>] device_unregister+0x48/0x60
        [<ffffffff82d4083c>] usb_hub_remove_port_device+0x1c/0x20
        [<ffffffff82d2a9cd>] hub_disconnect+0xdd/0x160
        [<ffffffff82d36ab7>] usb_unbind_interface+0x67/0x170
        [<ffffffff81f001a7>] __device_release_driver+0x87/0xe0
        [<ffffffff81f00559>] device_release_driver+0x29/0x40
        [<ffffffff81effc58>] bus_remove_device+0x148/0x160
        [<ffffffff81efd07f>] device_del+0x14f/0x1b0
        [<ffffffff82d344f9>] usb_disable_device+0xf9/0x280
        [<ffffffff82d34ff8>] usb_set_configuration+0x268/0x840
        [<ffffffff82d3a7fc>] usb_remove_store+0x4c/0x80
        [<ffffffff81efbb43>] dev_attr_store+0x13/0x20
        [<ffffffff812ffdaa>] sysfs_write_file+0xfa/0x150
        [<ffffffff8127f71d>] do_loop_readv_writev+0x4d/0x90
        [<ffffffff8127f999>] do_readv_writev+0xf9/0x1e0
        [<ffffffff8127faba>] vfs_writev+0x3a/0x60
        [<ffffffff8127fc60>] SyS_writev+0x50/0xd0
        [<ffffffff83db7d18>] tracesys+0xe1/0xe6

 other info that might help us debug this:

  Possible unsafe locking scenario:

        CPU0                    CPU1
        ----                    ----
   lock(dev_pm_qos_mtx);
                                lock(s_active#54);
                                lock(dev_pm_qos_mtx);
   lock(s_active#54);

  *** DEADLOCK ***

To avoid that, remove the calls to functions mentioned above from
under dev_pm_qos_mtx and introduce a separate lock to prevent races
between functions that add or remove device PM QoS sysfs attributes
from happening.

Reported-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
alexelder pushed a commit that referenced this pull request Apr 15, 2013
Check for the presence of the '/cpus' OF node before dereferencing it
blindly:

[    4.181793] Unable to handle kernel NULL pointer dereference at virtual address 0000001c
[    4.181793] pgd = c0004000
[    4.181823] [0000001c] *pgd=00000000
[    4.181823] Internal error: Oops: 5 [#1] SMP ARM
[    4.181823] Modules linked in:
[    4.181823] CPU: 1    Tainted: G        W     (3.8.0-15-generic #25~hbankD)
[    4.181854] PC is at of_get_next_child+0x64/0x70
[    4.181854] LR is at of_get_next_child+0x24/0x70
[    4.181854] pc : [<c04fda18>]    lr : [<c04fd9d8>]    psr: 60000113
[    4.181854] sp : ed891ec0  ip : ed891ec0  fp : ed891ed4
[    4.181884] r10: c04dafd0  r9 : c098690c  r8 : c0936208
[    4.181884] r7 : ed890000  r6 : c0a63d00  r5 : 00000000  r4 : 00000000
[    4.181884] r3 : 00000000  r2 : 00000000  r1 : 00000000  r0 : c0b2acc8
[    4.181884] Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment kernel
[    4.181884] Control: 10c5387d  Table: adcb804a  DAC: 00000015
[    4.181915] Process swapper/0 (pid: 1, stack limit = 0xed890238)
[    4.181915] Stack: (0xed891ec0 to 0xed892000)
[    4.181915] 1ec0: c09b7b70 00000007 ed891efc ed891ed8 c04daff4 c04fd9c0 00000000 c09b7b70
[    4.181915] 1ee0: 00000007 c0a63d00 ed890000 c0936208 ed891f54 ed891f00 c00088e0 c04dafdc
[    4.181945] 1f00: ed891f54 ed891f10 c006e940 00000000 00000000 00000007 00000007 c08a4914
[    4.181945] 1f20: 00000000 c07dbd30 c0a63d00 c09b7b70 00000007 c0a63d00 000000bc c0936208
[    4.181945] 1f40: c098690c c0986914 ed891f94 ed891f58 c0936a40 c00087bc 00000007 00000007
[    4.181976] 1f60: c0936208 be8bda20 b6eea010 c0a63d00 c064547c 00000000 00000000 00000000
[    4.181976] 1f80: 00000000 00000000 ed891fac ed891f98 c0645498 c09368c8 00000000 00000000
[    4.181976] 1fa0: 00000000 ed891fb0 c0014658 c0645488 00000000 00000000 00000000 00000000
[    4.182006] 1fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[    4.182006] 1fe0: 00000000 00000000 00000000 00000000 00000013 00000000 00000000 00000000
[    4.182037] [<c04fda18>] (of_get_next_child+0x64/0x70) from [<c04daff4>] (cpu0_cpufreq_driver_init+0x24/0x284)
[    4.182067] [<c04daff4>] (cpu0_cpufreq_driver_init+0x24/0x284) from [<c00088e0>] (do_one_initcall+0x130/0x1b0)
[    4.182067] [<c00088e0>] (do_one_initcall+0x130/0x1b0) from [<c0936a40>] (kernel_init_freeable+0x184/0x24c)
[    4.182098] [<c0936a40>] (kernel_init_freeable+0x184/0x24c) from [<c0645498>] (kernel_init+0x1c/0xf4)
[    4.182128] [<c0645498>] (kernel_init+0x1c/0xf4) from [<c0014658>] (ret_from_fork+0x14/0x20)
[    4.182128] Code: f57ff04f e320f004 e89da830 e89da830 (e595001c)
[    4.182128] ---[ end trace 634903a22e8609cb ]---
[    4.182189] Kernel panic - not syncing: Attempted to kill init!  exitcode=0x0000000b
[    4.182189]
[    4.642395] CPU0: stopping

[rjw: Changelog]
Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
alexelder pushed a commit that referenced this pull request Apr 15, 2013
The sched_clock_remote() implementation has the following inatomicity
problem on 32bit systems when accessing the remote scd->clock, which
is a 64bit value.

CPU0			CPU1

sched_clock_local()	sched_clock_remote(CPU0)
...
			remote_clock = scd[CPU0]->clock
			    read_low32bit(scd[CPU0]->clock)
cmpxchg64(scd->clock,...)
			    read_high32bit(scd[CPU0]->clock)

While the update of scd->clock is using an atomic64 mechanism, the
readout on the remote cpu is not, which can cause completely bogus
readouts.

It is a quite rare problem, because it requires the update to hit the
narrow race window between the low/high readout and the update must go
across the 32bit boundary.

The resulting misbehaviour is, that CPU1 will see the sched_clock on
CPU1 ~4 seconds ahead of it's own and update CPU1s sched_clock value
to this bogus timestamp. This stays that way due to the clamping
implementation for about 4 seconds until the synchronization with
CLOCK_MONOTONIC undoes the problem.

The issue is hard to observe, because it might only result in a less
accurate SCHED_OTHER timeslicing behaviour. To create observable
damage on realtime scheduling classes, it is necessary that the bogus
update of CPU1 sched_clock happens in the context of an realtime
thread, which then gets charged 4 seconds of RT runtime, which results
in the RT throttler mechanism to trigger and prevent scheduling of RT
tasks for a little less than 4 seconds. So this is quite unlikely as
well.

The issue was quite hard to decode as the reproduction time is between
2 days and 3 weeks and intrusive tracing makes it less likely, but the
following trace recorded with trace_clock=global, which uses
sched_clock_local(), gave the final hint:

  <idle>-0   0d..30 400269.477150: hrtimer_cancel: hrtimer=0xf7061e80
  <idle>-0   0d..30 400269.477151: hrtimer_start:  hrtimer=0xf7061e80 ...
irq/20-S-587 1d..32 400273.772118: sched_wakeup:   comm= ... target_cpu=0
  <idle>-0   0dN.30 400273.772118: hrtimer_cancel: hrtimer=0xf7061e80

What happens is that CPU0 goes idle and invokes
sched_clock_idle_sleep_event() which invokes sched_clock_local() and
CPU1 runs a remote wakeup for CPU0 at the same time, which invokes
sched_remote_clock(). The time jump gets propagated to CPU0 via
sched_remote_clock() and stays stale on both cores for ~4 seconds.

There are only two other possibilities, which could cause a stale
sched clock:

1) ktime_get() which reads out CLOCK_MONOTONIC returns a sporadic
   wrong value.

2) sched_clock() which reads the TSC returns a sporadic wrong value.

#1 can be excluded because sched_clock would continue to increase for
   one jiffy and then go stale.

#2 can be excluded because it would not make the clock jump
   forward. It would just result in a stale sched_clock for one jiffy.

After quite some brain twisting and finding the same pattern on other
traces, sched_clock_remote() remained the only place which could cause
such a problem and as explained above it's indeed racy on 32bit
systems.

So while on 64bit systems the readout is atomic, we need to verify the
remote readout on 32bit machines. We need to protect the local->clock
readout in sched_clock_remote() on 32bit as well because an NMI could
hit between the low and the high readout, call sched_clock_local() and
modify local->clock.

Thanks to Siegfried Wulsch for bearing with my debug requests and
going through the tedious tasks of running a bunch of reproducer
systems to generate the debug information which let me decode the
issue.

Reported-by: Siegfried Wulsch <Siegfried.Wulsch@rovema.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1304051544160.21884@ionos
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
alexelder pushed a commit that referenced this pull request Apr 15, 2013
The function tracing control loop used by perf spits out a warning
if the called function is not a control function. This is because
the control function references a per cpu allocated data structure
on struct ftrace_ops that is not allocated for other types of
functions.

commit 0a01640 "ftrace: Optimize the function tracer list loop"

Had an optimization done to all function tracing loops to optimize
for a single registered ops. Unfortunately, this allows for a slight
race when tracing starts or ends, where the stub function might be
called after the current registered ops is removed. In this case we
get the following dump:

root# perf stat -e ftrace:function sleep 1
[   74.339105] WARNING: at include/linux/ftrace.h:209 ftrace_ops_control_func+0xde/0xf0()
[   74.349522] Hardware name: PRIMERGY RX200 S6
[   74.357149] Modules linked in: sg igb iTCO_wdt ptp pps_core iTCO_vendor_support i7core_edac dca lpc_ich i2c_i801 coretemp edac_core crc32c_intel mfd_core ghash_clmulni_intel dm_multipath acpi_power_meter pcspk
r microcode vhost_net tun macvtap macvlan nfsd kvm_intel kvm auth_rpcgss nfs_acl lockd sunrpc uinput xfs libcrc32c sd_mod crc_t10dif sr_mod cdrom mgag200 i2c_algo_bit drm_kms_helper ttm qla2xxx mptsas ahci drm li
bahci scsi_transport_sas mptscsih libata scsi_transport_fc i2c_core mptbase scsi_tgt dm_mirror dm_region_hash dm_log dm_mod
[   74.446233] Pid: 1377, comm: perf Tainted: G        W    3.9.0-rc1 #1
[   74.453458] Call Trace:
[   74.456233]  [<ffffffff81062e3f>] warn_slowpath_common+0x7f/0xc0
[   74.462997]  [<ffffffff810fbc60>] ? rcu_note_context_switch+0xa0/0xa0
[   74.470272]  [<ffffffff811041a2>] ? __unregister_ftrace_function+0xa2/0x1a0
[   74.478117]  [<ffffffff81062e9a>] warn_slowpath_null+0x1a/0x20
[   74.484681]  [<ffffffff81102ede>] ftrace_ops_control_func+0xde/0xf0
[   74.491760]  [<ffffffff8162f400>] ftrace_call+0x5/0x2f
[   74.497511]  [<ffffffff8162f400>] ? ftrace_call+0x5/0x2f
[   74.503486]  [<ffffffff8162f400>] ? ftrace_call+0x5/0x2f
[   74.509500]  [<ffffffff810fbc65>] ? synchronize_sched+0x5/0x50
[   74.516088]  [<ffffffff816254d5>] ? _cond_resched+0x5/0x40
[   74.522268]  [<ffffffff810fbc65>] ? synchronize_sched+0x5/0x50
[   74.528837]  [<ffffffff811041a2>] ? __unregister_ftrace_function+0xa2/0x1a0
[   74.536696]  [<ffffffff816254d5>] ? _cond_resched+0x5/0x40
[   74.542878]  [<ffffffff8162402d>] ? mutex_lock+0x1d/0x50
[   74.548869]  [<ffffffff81105c67>] unregister_ftrace_function+0x27/0x50
[   74.556243]  [<ffffffff8111eadf>] perf_ftrace_event_register+0x9f/0x140
[   74.563709]  [<ffffffff816254d5>] ? _cond_resched+0x5/0x40
[   74.569887]  [<ffffffff8162402d>] ? mutex_lock+0x1d/0x50
[   74.575898]  [<ffffffff8111e94e>] perf_trace_destroy+0x2e/0x50
[   74.582505]  [<ffffffff81127ba9>] tp_perf_event_destroy+0x9/0x10
[   74.589298]  [<ffffffff811295d0>] free_event+0x70/0x1a0
[   74.595208]  [<ffffffff8112a579>] perf_event_release_kernel+0x69/0xa0
[   74.602460]  [<ffffffff816254d5>] ? _cond_resched+0x5/0x40
[   74.608667]  [<ffffffff8112a640>] put_event+0x90/0xc0
[   74.614373]  [<ffffffff8112a740>] perf_release+0x10/0x20
[   74.620367]  [<ffffffff811a3044>] __fput+0xf4/0x280
[   74.625894]  [<ffffffff811a31de>] ____fput+0xe/0x10
[   74.631387]  [<ffffffff81083697>] task_work_run+0xa7/0xe0
[   74.637452]  [<ffffffff81014981>] do_notify_resume+0x71/0xb0
[   74.643843]  [<ffffffff8162fa92>] int_signal+0x12/0x17

To fix this a new ftrace_ops flag is added that denotes the ftrace_list_end
ftrace_ops stub as just that, a stub. This flag is now checked in the
control loop and the function is not called if the flag is set.

Thanks to Jovi for not just reporting the bug, but also pointing out
where the bug was in the code.

Link: http://lkml.kernel.org/r/514A8855.7090402@redhat.com
Link: http://lkml.kernel.org/r/1364377499-1900-15-git-send-email-jovi.zhangwei@huawei.com

Tested-by: WANG Chao <chaowang@redhat.com>
Reported-by: WANG Chao <chaowang@redhat.com>
Reported-by: zhangwei(Jovi) <jovi.zhangwei@huawei.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
alexelder pushed a commit that referenced this pull request Apr 15, 2013
do_loopback calls lock_mount(path) and forget to unlock_mount
if clone_mnt or copy_mnt fails.

[   77.661566] ================================================
[   77.662939] [ BUG: lock held when returning to user space! ]
[   77.664104] 3.9.0-rc5+ #17 Not tainted
[   77.664982] ------------------------------------------------
[   77.666488] mount/514 is leaving the kernel with locks still held!
[   77.668027] 2 locks held by mount/514:
[   77.668817]  #0:  (&sb->s_type->i_mutex_key#7){+.+.+.}, at: [<ffffffff811cca22>] lock_mount+0x32/0xe0
[   77.671755]  #1:  (&namespace_sem){+++++.}, at: [<ffffffff811cca3a>] lock_mount+0x4a/0xe0

Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
alexelder pushed a commit that referenced this pull request Apr 15, 2013
In paravirtualized x86_64 kernels, vmalloc_fault may cause an oops
when lazy MMU updates are enabled, because set_pgd effects are being
deferred.

One instance of this problem is during process mm cleanup with memory
cgroups enabled. The chain of events is as follows:

- zap_pte_range enables lazy MMU updates
- zap_pte_range eventually calls mem_cgroup_charge_statistics,
  which accesses the vmalloc'd mem_cgroup per-cpu stat area
- vmalloc_fault is triggered which tries to sync the corresponding
  PGD entry with set_pgd, but the update is deferred
- vmalloc_fault oopses due to a mismatch in the PUD entries

The OOPs usually looks as so:

------------[ cut here ]------------
kernel BUG at arch/x86/mm/fault.c:396!
invalid opcode: 0000 [#1] SMP
.. snip ..
CPU 1
Pid: 10866, comm: httpd Not tainted 3.6.10-4.fc18.x86_64 #1
RIP: e030:[<ffffffff816271bf>]  [<ffffffff816271bf>] vmalloc_fault+0x11f/0x208
.. snip ..
Call Trace:
 [<ffffffff81627759>] do_page_fault+0x399/0x4b0
 [<ffffffff81004f4c>] ? xen_mc_extend_args+0xec/0x110
 [<ffffffff81624065>] page_fault+0x25/0x30
 [<ffffffff81184d03>] ? mem_cgroup_charge_statistics.isra.13+0x13/0x50
 [<ffffffff81186f78>] __mem_cgroup_uncharge_common+0xd8/0x350
 [<ffffffff8118aac7>] mem_cgroup_uncharge_page+0x57/0x60
 [<ffffffff8115fbc0>] page_remove_rmap+0xe0/0x150
 [<ffffffff8115311a>] ? vm_normal_page+0x1a/0x80
 [<ffffffff81153e61>] unmap_single_vma+0x531/0x870
 [<ffffffff81154962>] unmap_vmas+0x52/0xa0
 [<ffffffff81007442>] ? pte_mfn_to_pfn+0x72/0x100
 [<ffffffff8115c8f8>] exit_mmap+0x98/0x170
 [<ffffffff810050d9>] ? __raw_callee_save_xen_pmd_val+0x11/0x1e
 [<ffffffff81059ce3>] mmput+0x83/0xf0
 [<ffffffff810624c4>] exit_mm+0x104/0x130
 [<ffffffff8106264a>] do_exit+0x15a/0x8c0
 [<ffffffff810630ff>] do_group_exit+0x3f/0xa0
 [<ffffffff81063177>] sys_exit_group+0x17/0x20
 [<ffffffff8162bae9>] system_call_fastpath+0x16/0x1b

Calling arch_flush_lazy_mmu_mode immediately after set_pgd makes the
changes visible to the consistency checks.

Cc: <stable@vger.kernel.org>
RedHat-Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=914737
Tested-by: Josh Boyer <jwboyer@redhat.com>
Reported-and-Tested-by: Krishna Raman <kraman@redhat.com>
Signed-off-by: Samu Kallio <samu.kallio@aberdeencloud.com>
Link: http://lkml.kernel.org/r/1364045796-10720-1-git-send-email-konrad.wilk@oracle.com
Tested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
alexelder pushed a commit that referenced this pull request Apr 15, 2013
e100 uses pci_map_single, but fails to check for a dma mapping error after its
use, resulting in a stack trace:

[   46.656594] ------------[ cut here ]------------
[   46.657004] WARNING: at lib/dma-debug.c:933 check_unmap+0x47b/0x950()
[   46.657004] Hardware name: To Be Filled By O.E.M.
[   46.657004] e100 0000:00:0e.0: DMA-API: device driver failed to check map
error[device address=0x000000007a4540fa] [size=90 bytes] [mapped as single]
[   46.657004] Modules linked in:
[   46.657004]  w83627hf hwmon_vid snd_via82xx ppdev snd_ac97_codec ac97_bus
snd_seq snd_pcm snd_mpu401 snd_mpu401_uart ns558 snd_rawmidi gameport parport_pc
e100 snd_seq_device parport snd_page_alloc snd_timer snd soundcore skge shpchp
k8temp mii edac_core i2c_viapro edac_mce_amd nfsd auth_rpcgss nfs_acl lockd
sunrpc binfmt_misc uinput ata_generic pata_acpi radeon i2c_algo_bit
drm_kms_helper ttm firewire_ohci drm firewire_core pata_via sata_via i2c_core
sata_promise crc_itu_t
[   46.657004] Pid: 792, comm: ip Not tainted 3.8.0-0.rc6.git0.1.fc19.x86_64 #1
[   46.657004] Call Trace:
[   46.657004]  <IRQ>  [<ffffffff81065ed0>] warn_slowpath_common+0x70/0xa0
[   46.657004]  [<ffffffff81065f4c>] warn_slowpath_fmt+0x4c/0x50
[   46.657004]  [<ffffffff81364cfb>] check_unmap+0x47b/0x950
[   46.657004]  [<ffffffff8136522f>] debug_dma_unmap_page+0x5f/0x70
[   46.657004]  [<ffffffffa030f0f0>] ? e100_tx_clean+0x30/0x210 [e100]
[   46.657004]  [<ffffffffa030f1a8>] e100_tx_clean+0xe8/0x210 [e100]
[   46.657004]  [<ffffffffa030fc6f>] e100_poll+0x56f/0x6c0 [e100]
[   46.657004]  [<ffffffff8159dce1>] ? net_rx_action+0xa1/0x370
[   46.657004]  [<ffffffff8159ddb2>] net_rx_action+0x172/0x370
[   46.657004]  [<ffffffff810703bf>] __do_softirq+0xef/0x3d0
[   46.657004]  [<ffffffff816e4ebc>] call_softirq+0x1c/0x30
[   46.657004]  [<ffffffff8101c485>] do_softirq+0x85/0xc0
[   46.657004]  [<ffffffff81070885>] irq_exit+0xd5/0xe0
[   46.657004]  [<ffffffff816e5756>] do_IRQ+0x56/0xc0
[   46.657004]  [<ffffffff816dacb2>] common_interrupt+0x72/0x72
[   46.657004]  <EOI>  [<ffffffff816da1eb>] ?
_raw_spin_unlock_irqrestore+0x3b/0x70
[   46.657004]  [<ffffffff816d124d>] __slab_free+0x58/0x38b
[   46.657004]  [<ffffffff81214424>] ? fsnotify_clear_marks_by_inode+0x34/0x120
[   46.657004]  [<ffffffff811b0417>] ? kmem_cache_free+0x97/0x320
[   46.657004]  [<ffffffff8157fc14>] ? sock_destroy_inode+0x34/0x40
[   46.657004]  [<ffffffff8157fc14>] ? sock_destroy_inode+0x34/0x40
[   46.657004]  [<ffffffff811b0692>] kmem_cache_free+0x312/0x320
[   46.657004]  [<ffffffff8157fc14>] sock_destroy_inode+0x34/0x40
[   46.657004]  [<ffffffff811e8c28>] destroy_inode+0x38/0x60
[   46.657004]  [<ffffffff811e8d5e>] evict+0x10e/0x1a0
[   46.657004]  [<ffffffff811e9605>] iput+0xf5/0x180
[   46.657004]  [<ffffffff811e4338>] dput+0x248/0x310
[   46.657004]  [<ffffffff811ce0e1>] __fput+0x171/0x240
[   46.657004]  [<ffffffff811ce26e>] ____fput+0xe/0x10
[   46.657004]  [<ffffffff8108d54c>] task_work_run+0xac/0xe0
[   46.657004]  [<ffffffff8106c6ed>] do_exit+0x26d/0xc30
[   46.657004]  [<ffffffff8109eccc>] ? finish_task_switch+0x7c/0x120
[   46.657004]  [<ffffffff816dad58>] ? retint_swapgs+0x13/0x1b
[   46.657004]  [<ffffffff8106d139>] do_group_exit+0x49/0xc0
[   46.657004]  [<ffffffff8106d1c4>] sys_exit_group+0x14/0x20
[   46.657004]  [<ffffffff816e3b19>] system_call_fastpath+0x16/0x1b
[   46.657004] ---[ end trace 4468c44e2156e7d1 ]---
[   46.657004] Mapped at:
[   46.657004]  [<ffffffff813663d1>] debug_dma_map_page+0x91/0x140
[   46.657004]  [<ffffffffa030e8eb>] e100_xmit_prepare+0x12b/0x1c0 [e100]
[   46.657004]  [<ffffffffa030c924>] e100_exec_cb+0x84/0x140 [e100]
[   46.657004]  [<ffffffffa030e56a>] e100_xmit_frame+0x3a/0x190 [e100]
[   46.657004]  [<ffffffff8159ee89>] dev_hard_start_xmit+0x259/0x6c0

Easy fix, modify the cb paramter to e100_exec_cb to return an error, and do the
dma_mapping_error check in the obvious place

This was reported previously here:
http://article.gmane.org/gmane.linux.network/257893

But nobody stepped up and fixed it.

CC: Josh Boyer <jwboyer@redhat.com>
CC: e1000-devel@lists.sourceforge.net
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Reported-by: Michal Jaegermann <michal@harddata.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
alexelder pushed a commit that referenced this pull request Apr 15, 2013
This patch attempts to fix:

	https://bugzilla.kernel.org/show_bug.cgi?id=56461

The symptom is a crash and messages like this:

	chrome: Corrupted page table at address 34a03000
	*pdpt = 0000000000000000 *pde = 0000000000000000
	Bad pagetable: 000f [#1] PREEMPT SMP

Ingo guesses this got introduced by commit 611ae8e ("x86/tlb:
enable tlb flush range support for x86") since that code started to free
unused pagetables.

On x86-32 PAE kernels, that new code has the potential to free an entire
PMD page and will clear one of the four page-directory-pointer-table
(aka pgd_t entries).

The hardware aggressively "caches" these top-level entries and invlpg
does not actually affect the CPU's copy.  If we clear one we *HAVE* to
do a full TLB flush, otherwise we might continue using a freed pmd page.
(note, we do this properly on the population side in pud_populate()).

This patch tracks whenever we clear one of these entries in the 'struct
mmu_gather', and ensures that we follow up with a full tlb flush.

BTW, I disassembled and checked that:

	if (tlb->fullmm == 0)
and
	if (!tlb->fullmm && !tlb->need_flush_all)

generate essentially the same code, so there should be zero impact there
to the !PAE case.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Artem S Tashkinov <t.artem@mailcity.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
liewegas pushed a commit that referenced this pull request May 2, 2013
Currently IOP3XX_PERIPHERAL_VIRT_BASE conflicts with PCI_IO_VIRT_BASE:

					address         size
	PCI_IO_VIRT_BASE                0xfee00000      0x200000
	IOP3XX_PERIPHERAL_VIRT_BASE     0xfeffe000      0x2000

Fix by moving IOP3XX_PERIPHERAL_VIRT_BASE below PCI_IO_VIRT_BASE.

The patch fixes the following kernel panic with 3.9-rc1 on iop3xx boards:

[    0.000000] Booting Linux on physical CPU 0x0
[    0.000000] Initializing cgroup subsys cpu
[    0.000000] Linux version 3.9.0-rc1-iop32x (aaro@blackmetal) (gcc version 4.7.2 (GCC) ) #20 PREEMPT Tue Mar 5 16:44:36 EET 2013
[    0.000000] bootconsole [earlycon0] enabled
[    0.000000] ------------[ cut here ]------------
[    0.000000] kernel BUG at mm/vmalloc.c:1145!
[    0.000000] Internal error: Oops - BUG: 0 [#1] PREEMPT ARM
[    0.000000] Modules linked in:
[    0.000000] CPU: 0    Not tainted  (3.9.0-rc1-iop32x #20)
[    0.000000] PC is at vm_area_add_early+0x4c/0x88
[    0.000000] LR is at add_static_vm_early+0x14/0x68
[    0.000000] pc : [<c03e74a8>]    lr : [<c03e1c40>]    psr: 800000d3
[    0.000000] sp : c03ffee4  ip : dfffdf88  fp : c03ffef4
[    0.000000] r10: 00000002  r9 : 000000cf  r8 : 00000653
[    0.000000] r7 : c040eca8  r6 : c03e2408  r5 : dfffdf60  r4 : 00200000
[    0.000000] r3 : dfffdfd8  r2 : feffe000  r1 : ff000000  r0 : dfffdf60
[    0.000000] Flags: Nzcv  IRQs off  FIQs off  Mode SVC_32  ISA ARM  Segment kernel
[    0.000000] Control: 0000397f  Table: a0004000  DAC: 00000017
[    0.000000] Process swapper (pid: 0, stack limit = 0xc03fe1b8)
[    0.000000] Stack: (0xc03ffee4 to 0xc0400000)
[    0.000000] fee0:          00200000 c03fff0c c03ffef8 c03e1c40 c03e7468 00200000 fee00000
[    0.000000] ff00: c03fff2c c03fff10 c03e23e4 c03e1c38 feffe000 c0408ee4 ff000000 c0408f04
[    0.000000] ff20: c03fff3c c03fff30 c03e2434 c03e23b4 c03fff84 c03fff40 c03e2c94 c03e2414
[    0.000000] ff40: c03f8878 c03f6410 ffff0000 000bffff 00001000 00000008 c03fff84 c03f6410
[    0.000000] ff60: c04227e8 c03fffd4 a0008000 c03f8878 69052e30 c02f96eb c03fffbc c03fff88
[    0.000000] ff80: c03e044c c03e268c 00000000 0000397f c0385130 00000001 ffffffff c03f8874
[    0.000000] ffa0: dfffffff a0004000 69052e30 a03f61a0 c03ffff4 c03fffc0 c03dd5cc c03e0184
[    0.000000] ffc0: 00000000 00000000 00000000 00000000 00000000 c03f8878 0000397d c040601c
[    0.000000] ffe0: c03f8874 c0408674 00000000 c03ffff8 a0008040 c03dd558 00000000 00000000
[    0.000000] Backtrace:
[    0.000000] [<c03e745c>] (vm_area_add_early+0x0/0x88) from [<c03e1c40>] (add_static_vm_early+0x14/0x68)

Tested-by: Mikael Pettersson <mikpe@it.uu.se>
Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
liewegas pushed a commit that referenced this pull request May 2, 2013
The following RCU splat indicates lack of RCU protection:

[  953.267649] ===============================
[  953.267652] [ INFO: suspicious RCU usage. ]
[  953.267657] 3.9.0-0.rc6.git2.4.fc19.ppc64p7 #1 Not tainted
[  953.267661] -------------------------------
[  953.267664] include/linux/cgroup.h:534 suspicious rcu_dereference_check() usage!
[  953.267669]
[  953.267669] other info that might help us debug this:
[  953.267669]
[  953.267675]
[  953.267675] rcu_scheduler_active = 1, debug_locks = 0
[  953.267680] 1 lock held by glxgears/1289:
[  953.267683]  #0:  (&sig->cred_guard_mutex){+.+.+.}, at: [<c00000000027f884>] .prepare_bprm_creds+0x34/0xa0
[  953.267700]
[  953.267700] stack backtrace:
[  953.267704] Call Trace:
[  953.267709] [c0000001f0d1b6e0] [c000000000016e30] .show_stack+0x130/0x200 (unreliable)
[  953.267717] [c0000001f0d1b7b0] [c0000000001267f8] .lockdep_rcu_suspicious+0x138/0x180
[  953.267724] [c0000001f0d1b840] [c0000000001d43a4] .perf_event_comm+0x4c4/0x690
[  953.267731] [c0000001f0d1b950] [c00000000027f6e4] .set_task_comm+0x84/0x1f0
[  953.267737] [c0000001f0d1b9f0] [c000000000280414] .setup_new_exec+0x94/0x220
[  953.267744] [c0000001f0d1ba70] [c0000000002f665c] .load_elf_binary+0x58c/0x19b0
...

This commit therefore adds the required RCU read-side critical
section to perf_event_comm().

Reported-by: Adam Jackson <ajax@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: a.p.zijlstra@chello.nl
Cc: paulus@samba.org
Cc: acme@ghostprotocols.net
Link: http://lkml.kernel.org/r/20130419190124.GA8638@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Gustavo Luiz Duarte <gusld@br.ibm.com>
alexelder pushed a commit that referenced this pull request May 16, 2013
commit eb20ff9 upstream.

With deferred setup for SCO, it is possible that userspace closes the
socket when it is in the BT_CONNECT2 state, after the Connect Request is
received but before the Accept Synchonous Connection is sent.

If this happens the following crash was observed, when the connection is
terminated:

[  +0.000003] hci_sync_conn_complete_evt: hci0 status 0x10
[  +0.000005] sco_connect_cfm: hcon ffff88003d1bd800 bdaddr 40:98:4e:32:d7:39 status 16
[  +0.000003] sco_conn_del: hcon ffff88003d1bd800 conn ffff88003cc8e300, err 110
[  +0.000015] BUG: unable to handle kernel NULL pointer dereference at 0000000000000199
[  +0.000906] IP: [<ffffffff810620dd>] __lock_acquire+0xed/0xe82
[  +0.000000] PGD 3d21f067 PUD 3d291067 PMD 0
[  +0.000000] Oops: 0002 [#1] SMP
[  +0.000000] Modules linked in: rfcomm bnep btusb bluetooth
[  +0.000000] CPU 0
[  +0.000000] Pid: 1481, comm: kworker/u:2H Not tainted 3.9.0-rc1-25019-gad82cdd #1 Bochs Bochs
[  +0.000000] RIP: 0010:[<ffffffff810620dd>]  [<ffffffff810620dd>] __lock_acquire+0xed/0xe82
[  +0.000000] RSP: 0018:ffff88003c3c19d8  EFLAGS: 00010002
[  +0.000000] RAX: 0000000000000001 RBX: 0000000000000246 RCX: 0000000000000000
[  +0.000000] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88003d1be868
[  +0.000000] RBP: ffff88003c3c1a98 R08: 0000000000000002 R09: 0000000000000000
[  +0.000000] R10: ffff88003d1be868 R11: ffff88003e20b000 R12: 0000000000000002
[  +0.000000] R13: ffff88003aaa8000 R14: 000000000000006e R15: ffff88003d1be850
[  +0.000000] FS:  0000000000000000(0000) GS:ffff88003e200000(0000) knlGS:0000000000000000
[  +0.000000] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[  +0.000000] CR2: 0000000000000199 CR3: 000000003c1cb000 CR4: 00000000000006b0
[  +0.000000] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  +0.000000] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[  +0.000000] Process kworker/u:2H (pid: 1481, threadinfo ffff88003c3c0000, task ffff88003aaa8000)
[  +0.000000] Stack:
[  +0.000000]  ffffffff81b16342 0000000000000000 0000000000000000 ffff88003d1be868
[  +0.000000]  ffffffff00000000 00018c0c7863e367 000000003c3c1a28 ffffffff8101efbd
[  +0.000000]  0000000000000000 ffff88003e3d2400 ffff88003c3c1a38 ffffffff81007c7a
[  +0.000000] Call Trace:
[  +0.000000]  [<ffffffff8101efbd>] ? kvm_clock_read+0x34/0x3b
[  +0.000000]  [<ffffffff81007c7a>] ? paravirt_sched_clock+0x9/0xd
[  +0.000000]  [<ffffffff81007fd4>] ? sched_clock+0x9/0xb
[  +0.000000]  [<ffffffff8104fd7a>] ? sched_clock_local+0x12/0x75
[  +0.000000]  [<ffffffff810632d1>] lock_acquire+0x93/0xb1
[  +0.000000]  [<ffffffffa0022339>] ? spin_lock+0x9/0xb [bluetooth]
[  +0.000000]  [<ffffffff8105f3d8>] ? lock_release_holdtime.part.22+0x4e/0x55
[  +0.000000]  [<ffffffff814f6038>] _raw_spin_lock+0x40/0x74
[  +0.000000]  [<ffffffffa0022339>] ? spin_lock+0x9/0xb [bluetooth]
[  +0.000000]  [<ffffffff814f6936>] ? _raw_spin_unlock+0x23/0x36
[  +0.000000]  [<ffffffffa0022339>] spin_lock+0x9/0xb [bluetooth]
[  +0.000000]  [<ffffffffa00230cc>] sco_conn_del+0x76/0xbb [bluetooth]
[  +0.000000]  [<ffffffffa002391d>] sco_connect_cfm+0x2da/0x2e9 [bluetooth]
[  +0.000000]  [<ffffffffa000862a>] hci_proto_connect_cfm+0x38/0x65 [bluetooth]
[  +0.000000]  [<ffffffffa0008d30>] hci_sync_conn_complete_evt.isra.79+0x11a/0x13e [bluetooth]
[  +0.000000]  [<ffffffffa000cd96>] hci_event_packet+0x153b/0x239d [bluetooth]
[  +0.000000]  [<ffffffff814f68ff>] ? _raw_spin_unlock_irqrestore+0x48/0x5c
[  +0.000000]  [<ffffffffa00025f6>] hci_rx_work+0xf3/0x2e3 [bluetooth]
[  +0.000000]  [<ffffffff8103efed>] process_one_work+0x1dc/0x30b
[  +0.000000]  [<ffffffff8103ef83>] ? process_one_work+0x172/0x30b
[  +0.000000]  [<ffffffff8103e07f>] ? spin_lock_irq+0x9/0xb
[  +0.000000]  [<ffffffff8103fc8d>] worker_thread+0x123/0x1d2
[  +0.000000]  [<ffffffff8103fb6a>] ? manage_workers+0x240/0x240
[  +0.000000]  [<ffffffff81044211>] kthread+0x9d/0xa5
[  +0.000000]  [<ffffffff81044174>] ? __kthread_parkme+0x60/0x60
[  +0.000000]  [<ffffffff814f75bc>] ret_from_fork+0x7c/0xb0
[  +0.000000]  [<ffffffff81044174>] ? __kthread_parkme+0x60/0x60
[  +0.000000] Code: d7 44 89 8d 50 ff ff ff 4c 89 95 58 ff ff ff e8 44 fc ff ff 44 8b 8d 50 ff ff ff 48 85 c0 4c 8b 95 58 ff ff ff 0f 84 7a 04 00 00 <f0> ff 80 98 01 00 00 83 3d 25 41 a7 00 00 45 8b b5 e8 05 00 00
[  +0.000000] RIP  [<ffffffff810620dd>] __lock_acquire+0xed/0xe82
[  +0.000000]  RSP <ffff88003c3c19d8>
[  +0.000000] CR2: 0000000000000199
[  +0.000000] ---[ end trace e73cd3b52352dd34 ]---

Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@openbossa.org>
Tested-by: Frederic Dalleau <frederic.dalleau@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
alexelder pushed a commit that referenced this pull request May 16, 2013
commit 7fc0357 upstream.

The following issue was reported.

WARNING: at net/mac80211/util.c:599 ieee80211_can_queue_work.isra.7+0x32/0x40 [mac80211]()
Hardware name: iMac12,1
queueing ieee80211 work while going to suspend
Pid: 0, comm: swapper/0 Tainted: PF          O 3.8.2-206.fc18.x86_64 #1
Call Trace: Mar 16 09:39:17 Parags-iMac kernel: [ 3993.642992]  <IRQ>
[<ffffffff8105e61f>] warn_slowpath_common+0x7f/0xc0
[<ffffffffa0581420>] ? ath_start_rx_poll+0x70/0x70 [ath9k]
<ffffffff8105e716>] warn_slowpath_fmt+0x46/0x50
[<ffffffffa045b542>] ieee80211_can_queue_work.isra.7+0x32/0x40

Fix this by avoiding to queue the work if our device has
already been marked as suspended or stopped.

Reported-by: Parag Warudkar <parag.lkml@gmail.com>
Tested-by: Parag Warudkar <parag.lkml@gmail.com>
Signed-off-by: Luis R. Rodriguez <mcgrof@do-not-panic.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
alexelder pushed a commit that referenced this pull request May 16, 2013
commit ff931c8 upstream.

clk inits on OMAP happen quite early, even before slab is available.
The dependency comes from the fact that the timer init code starts to
use clocks and hwmod and we need clocks to be initialized by then.

There are various problems doing clk inits this early, one is,
not being able to do dynamic clk registrations and hence the
dependency on clk-private.h. The other is, inability to debug
early kernel crashes without enabling DEBUG_LL and earlyprintk.

Doing early clk init also exposed another instance of a kernel
panic due to a BUG() when CONFIG_DEBUG_SLAB is enabled.

[    0.000000] Kernel BUG at c01174f8 [verbose debug info unavailable]
[    0.000000] Internal error: Oops - BUG: 0 [#1] SMP ARM
[    0.000000] Modules linked in:
[    0.000000] CPU: 0    Not tainted  (3.9.0-rc1-12179-g72d48f9 #6)
[    0.000000] PC is at __kmalloc+0x1d4/0x248
[    0.000000] LR is at __clk_init+0x2e0/0x364
[    0.000000] pc : [<c01174f8>]    lr : [<c0441f54>]    psr: 600001d3
[    0.000000] sp : c076ff28  ip : c065cefc  fp : c0441f54
[    0.000000] r10: 0000001c  r9 : 000080d0  r8 : c076ffd4
[    0.000000] r7 : c074b578  r6 : c0794d88  r5 : 00000040  r4 : 00000000
[    0.000000] r3 : 00000000  r2 : c07cac70  r1 : 000080d0  r0 : 0000001c
[    0.000000] Flags: nZCv  IRQs off  FIQs off  Mode SVC_32  ISA ARM  Segment kernel
[    0.000000] Control: 10c53c7d  Table: 8000404a  DAC: 00000017
[    0.000000] Process swapper (pid: 0, stack limit = 0xc076e240)
[    0.000000] Stack: (0xc076ff28 to 0xc0770000)
[    0.000000] ff20:                   22222222 c0794ec8 c06546e8 00000000 00000040 c0794d88
[    0.000000] ff40: c074b578 c076ffd4 c07951c8 c076e000 00000000 c0441f54 c074b578 c076ffd4
[    0.000000] ff60: c0793828 00000040 c0794d88 c074b578 c076ffd4 c0776900 c076e000 c07272ac
[    0.000000] ff80: 2f800000 c074c968 c07f93d0 c0719780 c076ffa0 c076ff98 00000000 00000000
[    0.000000] ffa0: 00000000 00000000 00000000 00000001 c074cd6c c077b1ec 8000406a c0715724
[    0.000000] ffc0: 00000000 00000000 00000000 00000000 00000000 c074c968 10c53c7d c0776974
[    0.000000] ffe0: c074cd6c c077b1ec 8000406a 411fc092 00000000 80008074 00000000 00000000
[    0.000000] [<c01174f8>] (__kmalloc+0x1d4/0x248) from [<c0441f54>] (__clk_init+0x2e0/0x364)
[    0.000000] [<c0441f54>] (__clk_init+0x2e0/0x364) from [<c07272ac>] (omap4xxx_clk_init+0xbc/0x140)
[    0.000000] [<c07272ac>] (omap4xxx_clk_init+0xbc/0x140) from [<c0719780>] (setup_arch+0x15c/0x284)
[    0.000000] [<c0719780>] (setup_arch+0x15c/0x284) from [<c0715724>] (start_kernel+0x7c/0x334)
[    0.000000] [<c0715724>] (start_kernel+0x7c/0x334) from [<80008074>] (0x80008074)
[    0.000000] Code: e5883004 e1a00006 e28dd00c e8bd8ff0 (e7f001f2)
[    0.000000] ---[ end trace 1b75b31a2719ed1c ]---
[    0.000000] Kernel panic - not syncing: Attempted to kill the idle task!

It was a know issue, that slab allocations would fail when common
clock core tries to cache parent pointers for mux clocks on OMAP,
and hence a patch 'clk: Allow late cache allocation for clk->parents,
commit 7975059' was added to work this problem around.
A BUG() within kmalloc() with CONFIG_DEBUG_SLAB enabled was completely
overlooked causing this regression.

More details on the issue reported can be found here,
http://www.mail-archive.com/linux-omap@vger.kernel.org/msg85932.html

With all these issues around clk inits happening way too early, it
makes sense to at least move them to a point where dynamic memory
allocations are possible. So move them to a point just before the
timer code starts using clocks and hwmod.

This should at least pave way for clk inits on OMAP moving to dynamic
clock registrations instead of using the static macros defined in
clk-private.h.

The issue with kernel panic while CONFIG_DEBUG_SLAB is enabled
was reported by Piotr Haber and Tony Lindgren and this patch
fixes the reported issue as well.

Reported-by: Piotr Haber <phaber@broadcom.com>
Reported-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Rajendra Nayak <rnayak@ti.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Reviewed-by: Mike Turquette <mturquette@linaro.org>
Acked-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
alexelder pushed a commit that referenced this pull request May 16, 2013
commit 1de14c3 upstream.

This patch attempts to fix:

	https://bugzilla.kernel.org/show_bug.cgi?id=56461

The symptom is a crash and messages like this:

	chrome: Corrupted page table at address 34a03000
	*pdpt = 0000000000000000 *pde = 0000000000000000
	Bad pagetable: 000f [#1] PREEMPT SMP

Ingo guesses this got introduced by commit 611ae8e ("x86/tlb:
enable tlb flush range support for x86") since that code started to free
unused pagetables.

On x86-32 PAE kernels, that new code has the potential to free an entire
PMD page and will clear one of the four page-directory-pointer-table
(aka pgd_t entries).

The hardware aggressively "caches" these top-level entries and invlpg
does not actually affect the CPU's copy.  If we clear one we *HAVE* to
do a full TLB flush, otherwise we might continue using a freed pmd page.
(note, we do this properly on the population side in pud_populate()).

This patch tracks whenever we clear one of these entries in the 'struct
mmu_gather', and ensures that we follow up with a full tlb flush.

BTW, I disassembled and checked that:

	if (tlb->fullmm == 0)
and
	if (!tlb->fullmm && !tlb->need_flush_all)

generate essentially the same code, so there should be zero impact there
to the !PAE case.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Artem S Tashkinov <t.artem@mailcity.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
alexelder pushed a commit that referenced this pull request May 16, 2013
commit a1cbcaa upstream.

The sched_clock_remote() implementation has the following inatomicity
problem on 32bit systems when accessing the remote scd->clock, which
is a 64bit value.

CPU0			CPU1

sched_clock_local()	sched_clock_remote(CPU0)
...
			remote_clock = scd[CPU0]->clock
			    read_low32bit(scd[CPU0]->clock)
cmpxchg64(scd->clock,...)
			    read_high32bit(scd[CPU0]->clock)

While the update of scd->clock is using an atomic64 mechanism, the
readout on the remote cpu is not, which can cause completely bogus
readouts.

It is a quite rare problem, because it requires the update to hit the
narrow race window between the low/high readout and the update must go
across the 32bit boundary.

The resulting misbehaviour is, that CPU1 will see the sched_clock on
CPU1 ~4 seconds ahead of it's own and update CPU1s sched_clock value
to this bogus timestamp. This stays that way due to the clamping
implementation for about 4 seconds until the synchronization with
CLOCK_MONOTONIC undoes the problem.

The issue is hard to observe, because it might only result in a less
accurate SCHED_OTHER timeslicing behaviour. To create observable
damage on realtime scheduling classes, it is necessary that the bogus
update of CPU1 sched_clock happens in the context of an realtime
thread, which then gets charged 4 seconds of RT runtime, which results
in the RT throttler mechanism to trigger and prevent scheduling of RT
tasks for a little less than 4 seconds. So this is quite unlikely as
well.

The issue was quite hard to decode as the reproduction time is between
2 days and 3 weeks and intrusive tracing makes it less likely, but the
following trace recorded with trace_clock=global, which uses
sched_clock_local(), gave the final hint:

  <idle>-0   0d..30 400269.477150: hrtimer_cancel: hrtimer=0xf7061e80
  <idle>-0   0d..30 400269.477151: hrtimer_start:  hrtimer=0xf7061e80 ...
irq/20-S-587 1d..32 400273.772118: sched_wakeup:   comm= ... target_cpu=0
  <idle>-0   0dN.30 400273.772118: hrtimer_cancel: hrtimer=0xf7061e80

What happens is that CPU0 goes idle and invokes
sched_clock_idle_sleep_event() which invokes sched_clock_local() and
CPU1 runs a remote wakeup for CPU0 at the same time, which invokes
sched_remote_clock(). The time jump gets propagated to CPU0 via
sched_remote_clock() and stays stale on both cores for ~4 seconds.

There are only two other possibilities, which could cause a stale
sched clock:

1) ktime_get() which reads out CLOCK_MONOTONIC returns a sporadic
   wrong value.

2) sched_clock() which reads the TSC returns a sporadic wrong value.

#1 can be excluded because sched_clock would continue to increase for
   one jiffy and then go stale.

#2 can be excluded because it would not make the clock jump
   forward. It would just result in a stale sched_clock for one jiffy.

After quite some brain twisting and finding the same pattern on other
traces, sched_clock_remote() remained the only place which could cause
such a problem and as explained above it's indeed racy on 32bit
systems.

So while on 64bit systems the readout is atomic, we need to verify the
remote readout on 32bit machines. We need to protect the local->clock
readout in sched_clock_remote() on 32bit as well because an NMI could
hit between the low and the high readout, call sched_clock_local() and
modify local->clock.

Thanks to Siegfried Wulsch for bearing with my debug requests and
going through the tedious tasks of running a bunch of reproducer
systems to generate the debug information which let me decode the
issue.

Reported-by: Siegfried Wulsch <Siegfried.Wulsch@rovema.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1304051544160.21884@ionos
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
alexelder pushed a commit that referenced this pull request May 16, 2013
commit 1160c27 upstream.

In paravirtualized x86_64 kernels, vmalloc_fault may cause an oops
when lazy MMU updates are enabled, because set_pgd effects are being
deferred.

One instance of this problem is during process mm cleanup with memory
cgroups enabled. The chain of events is as follows:

- zap_pte_range enables lazy MMU updates
- zap_pte_range eventually calls mem_cgroup_charge_statistics,
  which accesses the vmalloc'd mem_cgroup per-cpu stat area
- vmalloc_fault is triggered which tries to sync the corresponding
  PGD entry with set_pgd, but the update is deferred
- vmalloc_fault oopses due to a mismatch in the PUD entries

The OOPs usually looks as so:

------------[ cut here ]------------
kernel BUG at arch/x86/mm/fault.c:396!
invalid opcode: 0000 [#1] SMP
.. snip ..
CPU 1
Pid: 10866, comm: httpd Not tainted 3.6.10-4.fc18.x86_64 #1
RIP: e030:[<ffffffff816271bf>]  [<ffffffff816271bf>] vmalloc_fault+0x11f/0x208
.. snip ..
Call Trace:
 [<ffffffff81627759>] do_page_fault+0x399/0x4b0
 [<ffffffff81004f4c>] ? xen_mc_extend_args+0xec/0x110
 [<ffffffff81624065>] page_fault+0x25/0x30
 [<ffffffff81184d03>] ? mem_cgroup_charge_statistics.isra.13+0x13/0x50
 [<ffffffff81186f78>] __mem_cgroup_uncharge_common+0xd8/0x350
 [<ffffffff8118aac7>] mem_cgroup_uncharge_page+0x57/0x60
 [<ffffffff8115fbc0>] page_remove_rmap+0xe0/0x150
 [<ffffffff8115311a>] ? vm_normal_page+0x1a/0x80
 [<ffffffff81153e61>] unmap_single_vma+0x531/0x870
 [<ffffffff81154962>] unmap_vmas+0x52/0xa0
 [<ffffffff81007442>] ? pte_mfn_to_pfn+0x72/0x100
 [<ffffffff8115c8f8>] exit_mmap+0x98/0x170
 [<ffffffff810050d9>] ? __raw_callee_save_xen_pmd_val+0x11/0x1e
 [<ffffffff81059ce3>] mmput+0x83/0xf0
 [<ffffffff810624c4>] exit_mm+0x104/0x130
 [<ffffffff8106264a>] do_exit+0x15a/0x8c0
 [<ffffffff810630ff>] do_group_exit+0x3f/0xa0
 [<ffffffff81063177>] sys_exit_group+0x17/0x20
 [<ffffffff8162bae9>] system_call_fastpath+0x16/0x1b

Calling arch_flush_lazy_mmu_mode immediately after set_pgd makes the
changes visible to the consistency checks.

RedHat-Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=914737
Tested-by: Josh Boyer <jwboyer@redhat.com>
Reported-and-Tested-by: Krishna Raman <kraman@redhat.com>
Signed-off-by: Samu Kallio <samu.kallio@aberdeencloud.com>
Link: http://lkml.kernel.org/r/1364045796-10720-1-git-send-email-konrad.wilk@oracle.com
Tested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
alexelder pushed a commit that referenced this pull request May 16, 2013
commit 852e4a8 upstream.

Since commit 89c8d91 ("tty: localise the lock") I see a dead lock
in one of my dummy_hcd + g_nokia test cases. The first run was usually
okay, the second often resulted in a splat by lockdep and the third was
usually a dead lock.
Lockdep complained about tty->hangup_work and tty->legacy_mutex taken
both ways:
| ======================================================
| [ INFO: possible circular locking dependency detected ]
| 3.7.0-rc6+ #204 Not tainted
| -------------------------------------------------------
| kworker/2:1/35 is trying to acquire lock:
|  (&tty->legacy_mutex){+.+.+.}, at: [<c14051e6>] tty_lock_nested+0x36/0x80
|
| but task is already holding lock:
|  ((&tty->hangup_work)){+.+...}, at: [<c104f6e4>] process_one_work+0x124/0x5e0
|
| which lock already depends on the new lock.
|
| the existing dependency chain (in reverse order) is:
|
| -> #2 ((&tty->hangup_work)){+.+...}:
|        [<c107fe74>] lock_acquire+0x84/0x190
|        [<c104d82d>] flush_work+0x3d/0x240
|        [<c12e6986>] tty_ldisc_flush_works+0x16/0x30
|        [<c12e7861>] tty_ldisc_release+0x21/0x70
|        [<c12e0dfc>] tty_release+0x35c/0x470
|        [<c1105e28>] __fput+0xd8/0x270
|        [<c1105fcd>] ____fput+0xd/0x10
|        [<c1051dd9>] task_work_run+0xb9/0xf0
|        [<c1002a51>] do_notify_resume+0x51/0x80
|        [<c140550a>] work_notifysig+0x35/0x3b
|
| -> #1 (&tty->legacy_mutex/1){+.+...}:
|        [<c107fe74>] lock_acquire+0x84/0x190
|        [<c140276c>] mutex_lock_nested+0x6c/0x2f0
|        [<c14051e6>] tty_lock_nested+0x36/0x80
|        [<c1405279>] tty_lock_pair+0x29/0x70
|        [<c12e0bb8>] tty_release+0x118/0x470
|        [<c1105e28>] __fput+0xd8/0x270
|        [<c1105fcd>] ____fput+0xd/0x10
|        [<c1051dd9>] task_work_run+0xb9/0xf0
|        [<c1002a51>] do_notify_resume+0x51/0x80
|        [<c140550a>] work_notifysig+0x35/0x3b
|
| -> #0 (&tty->legacy_mutex){+.+.+.}:
|        [<c107f3c9>] __lock_acquire+0x1189/0x16a0
|        [<c107fe74>] lock_acquire+0x84/0x190
|        [<c140276c>] mutex_lock_nested+0x6c/0x2f0
|        [<c14051e6>] tty_lock_nested+0x36/0x80
|        [<c140523f>] tty_lock+0xf/0x20
|        [<c12df8e4>] __tty_hangup+0x54/0x410
|        [<c12dfcb2>] do_tty_hangup+0x12/0x20
|        [<c104f763>] process_one_work+0x1a3/0x5e0
|        [<c104fec9>] worker_thread+0x119/0x3a0
|        [<c1055084>] kthread+0x94/0xa0
|        [<c140ca37>] ret_from_kernel_thread+0x1b/0x28
|
|other info that might help us debug this:
|
|Chain exists of:
|  &tty->legacy_mutex --> &tty->legacy_mutex/1 --> (&tty->hangup_work)
|
| Possible unsafe locking scenario:
|
|       CPU0                    CPU1
|       ----                    ----
|  lock((&tty->hangup_work));
|                               lock(&tty->legacy_mutex/1);
|                               lock((&tty->hangup_work));
|  lock(&tty->legacy_mutex);
|
| *** DEADLOCK ***

Before the path mentioned tty_ldisc_release() look like this:

|	tty_ldisc_halt(tty);
|	tty_ldisc_flush_works(tty);
|	tty_lock();

As it can be seen, it first flushes the workqueue and then grabs the
tty_lock. Now we grab the lock first:

|	tty_lock_pair(tty, o_tty);
|	tty_ldisc_halt(tty);
|	tty_ldisc_flush_works(tty);

so lockdep's complaint seems valid.

The earlier version of this patch took the ldisc_mutex since the other
user of tty_ldisc_flush_works() (tty_set_ldisc()) did this.
Peter Hurley then said that it is should not be requried. Since it
wasn't done earlier, I dropped this part.
The code under tty_ldisc_kill() was executed earlier with the tty lock
taken so it is taken again.

I was able to reproduce the deadlock on v3.8-rc1, this patch fixes the
problem in my testcase. I didn't notice any problems so far.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: Bryan O'Donoghue <bryan.odonoghue.lkml@nexus-software.ie>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
alexelder pushed a commit that referenced this pull request May 21, 2013
commit d9b8706 upstream.

usbnet_disconnect() will set intfdata to NULL before calling
the minidriver unbind function.  The cdc_wdm subdriver cannot
know that it is disconnecting until the qmi_wwan unbind
function has called its disconnect function.  This means that
we must be able to support the cdc_wdm subdriver operating
normally while usbnet_disconnect() is running, and in
particular that intfdata may be NULL.

The only place this matters is in qmi_wwan_cdc_wdm_manage_power
which is called from cdc_wdm.  Simply testing for NULL
intfdata there is sufficient to allow it to continue working
at all times.

Fixes this Oops where a cdc-wdm device was closed while the
USB device was disconnecting, causing wdm_release to call
qmi_wwan_cdc_wdm_manage_power after intfdata was set to
NULL by usbnet_disconnect:

[41819.087460] BUG: unable to handle kernel NULL pointer dereference at 00000080
[41819.087815] IP: [<f8640458>] qmi_wwan_manage_power+0x68/0x90 [qmi_wwan]
[41819.088028] *pdpt = 000000000314f001 *pde = 0000000000000000
[41819.088028] Oops: 0002 [#1] SMP
[41819.088028] Modules linked in: qmi_wwan option usb_wwan usbserial usbnet
cdc_wdm nls_iso8859_1 nls_cp437 vfat fat usb_storage bnep rfcomm bluetooth
parport_pc ppdev binfmt_misc iptable_nat nf_nat nf_conntrack_ipv4
nf_conntrack nf_defrag_ipv4 iptable_mangle iptable_filter ip_tables
x_tables dm_crypt uvcvideo snd_hda_codec_realtek snd_hda_intel
videobuf2_core snd_hda_codec joydev videodev videobuf2_vmalloc
hid_multitouch snd_hwdep arc4 videobuf2_memops snd_pcm snd_seq_midi
snd_rawmidi snd_seq_midi_event ath9k mac80211 snd_seq ath9k_common ath9k_hw
ath snd_timer snd_seq_device sparse_keymap dm_multipath scsi_dh coretemp
mac_hid snd soundcore cfg80211 snd_page_alloc psmouse serio_raw microcode
lp parport dm_mirror dm_region_hash dm_log usbhid hid i915 drm_kms_helper
drm r8169 i2c_algo_bit wmi video [last unloaded: qmi_wwan]
[41819.088028]
[41819.088028] Pid: 23292, comm: qmicli Not tainted 3.4.0-5-generic #11-Ubuntu GIGABYTE T1005/T1005
[41819.088028] EIP: 0060:[<f8640458>] EFLAGS: 00010246 CPU: 1
[41819.088028] EIP is at qmi_wwan_manage_power+0x68/0x90 [qmi_wwan]
[41819.088028] EAX: 00000000 EBX: 00000000 ECX: 000000c3 EDX: 00000000
[41819.088028] ESI: c3b27658 EDI: 00000000 EBP: c298bea4 ESP: c298be98
[41819.088028]  DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
[41819.088028] CR0: 8005003b CR2: 00000080 CR3: 3605e000 CR4: 000007f0
[41819.088028] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
[41819.088028] DR6: ffff0ff0 DR7: 00000400
[41819.088028] Process qmicli (pid: 23292, ti=c298a000 task=f343b280 task.ti=c298a000)
[41819.088028] Stack:
[41819.088028]  00000000 c3b27658 e2a80d00 c298beb0 f864051a c3b27600 c298bec0 f9027099
[41819.088028]  c2fd6000 00000008 c298bef0 c1147f96 00000001 00000000 00000000 f4e54790
[41819.088028]  ecf43a00 ecf43a00 c2fd6008 c2fd6000 ebbd7600 ffffffb9 c298bf08 c1144474
[41819.088028] Call Trace:
[41819.088028]  [<f864051a>] qmi_wwan_cdc_wdm_manage_power+0x1a/0x20 [qmi_wwan]
[41819.088028]  [<f9027099>] wdm_release+0x69/0x70 [cdc_wdm]
[41819.088028]  [<c1147f96>] fput+0xe6/0x210
[41819.088028]  [<c1144474>] filp_close+0x54/0x80
[41819.088028]  [<c1046a65>] put_files_struct+0x75/0xc0
[41819.088028]  [<c1046b56>] exit_files+0x46/0x60
[41819.088028]  [<c1046f81>] do_exit+0x141/0x780
[41819.088028]  [<c107248f>] ? wake_up_state+0xf/0x20
[41819.088028]  [<c1053f48>] ? signal_wake_up+0x28/0x40
[41819.088028]  [<c1054f3b>] ? zap_other_threads+0x6b/0x80
[41819.088028]  [<c1047864>] do_group_exit+0x34/0xa0
[41819.088028]  [<c10478e8>] sys_exit_group+0x18/0x20
[41819.088028]  [<c15bb7df>] sysenter_do_call+0x12/0x28
[41819.088028] Code: 04 83 e7 01 c1 e7 03 0f b6 42 18 83 e0 f7 09 f8 88 42
18 8b 43 04 e8 48 9a dd c8 89 f0 8b 5d f4 8b 75 f8 8b 7d fc 89 ec 5d c3 90
<f0> ff 88 80 00 00 00 0f 94 c0 84 c0 75 b7 31 f6 8b 5d f4 89 f0
[41819.088028] EIP: [<f8640458>] qmi_wwan_manage_power+0x68/0x90 [qmi_wwan] SS:ESP 0068:c298be98
[41819.088028] CR2: 0000000000000080
[41819.149492] ---[ end trace 0944479ff8257f55 ]---

Reported-by: Marius Bjørnstad Kotsbak <marius.kotsbak@gmail.com>
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
alexelder pushed a commit that referenced this pull request May 21, 2013
commit 6266230 upstream.

If CONFIG_DM_DEBUG_SPACE_MAPS is enabled and dm_sm_checker_create()
fails, dm_tm_create_internal() would still return success even though it
cleaned up all resources it was supposed to have created.  This will
lead to a kernel crash:

general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC
...
RIP: 0010:[<ffffffff81593659>]  [<ffffffff81593659>] dm_bufio_get_block_size+0x9/0x20
Call Trace:
  [<ffffffff81599bae>] dm_bm_block_size+0xe/0x10
  [<ffffffff8159b8b8>] sm_ll_init+0x78/0xd0
  [<ffffffff8159c1a6>] sm_ll_new_disk+0x16/0xa0
  [<ffffffff8159c98e>] dm_sm_disk_create+0xfe/0x160
  [<ffffffff815abf6e>] dm_pool_metadata_open+0x16e/0x6a0
  [<ffffffff815aa010>] pool_ctr+0x3f0/0x900
  [<ffffffff8158d565>] dm_table_add_target+0x195/0x450
  [<ffffffff815904c4>] table_load+0xe4/0x330
  [<ffffffff815917ea>] ctl_ioctl+0x15a/0x2c0
  [<ffffffff81591963>] dm_ctl_ioctl+0x13/0x20
  [<ffffffff8116a4f8>] do_vfs_ioctl+0x98/0x560
  [<ffffffff8116aa51>] sys_ioctl+0x91/0xa0
  [<ffffffff81869f52>] system_call_fastpath+0x16/0x1b

Fix the space map checker code to return an appropriate ERR_PTR and have
dm_sm_disk_create() and dm_tm_create_internal() check for it with
IS_ERR.

Reported-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
alexelder pushed a commit that referenced this pull request May 21, 2013
commit 60d65f1 upstream.

Don't grab the daemon mutex while holding the message context mutex.
Addresses this lockdep warning:

 ecryptfsd/2141 is trying to acquire lock:
  (&ecryptfs_msg_ctx_arr[i].mux){+.+.+.}, at: [<ffffffffa029c213>] ecryptfs_miscdev_read+0x143/0x470 [ecryptfs]

 but task is already holding lock:
  (&(*daemon)->mux){+.+...}, at: [<ffffffffa029c2ec>] ecryptfs_miscdev_read+0x21c/0x470 [ecryptfs]

 which lock already depends on the new lock.

 the existing dependency chain (in reverse order) is:

 -> #1 (&(*daemon)->mux){+.+...}:
        [<ffffffff810a3b8d>] lock_acquire+0x9d/0x220
        [<ffffffff8151c6da>] __mutex_lock_common+0x5a/0x4b0
        [<ffffffff8151cc64>] mutex_lock_nested+0x44/0x50
        [<ffffffffa029c5d7>] ecryptfs_send_miscdev+0x97/0x120 [ecryptfs]
        [<ffffffffa029b744>] ecryptfs_send_message+0x134/0x1e0 [ecryptfs]
        [<ffffffffa029a24e>] ecryptfs_generate_key_packet_set+0x2fe/0xa80 [ecryptfs]
        [<ffffffffa02960f8>] ecryptfs_write_metadata+0x108/0x250 [ecryptfs]
        [<ffffffffa0290f80>] ecryptfs_create+0x130/0x250 [ecryptfs]
        [<ffffffff811963a4>] vfs_create+0xb4/0x120
        [<ffffffff81197865>] do_last+0x8c5/0xa10
        [<ffffffff811998f9>] path_openat+0xd9/0x460
        [<ffffffff81199da2>] do_filp_open+0x42/0xa0
        [<ffffffff81187998>] do_sys_open+0xf8/0x1d0
        [<ffffffff81187a91>] sys_open+0x21/0x30
        [<ffffffff81527d69>] system_call_fastpath+0x16/0x1b

 -> #0 (&ecryptfs_msg_ctx_arr[i].mux){+.+.+.}:
        [<ffffffff810a3418>] __lock_acquire+0x1bf8/0x1c50
        [<ffffffff810a3b8d>] lock_acquire+0x9d/0x220
        [<ffffffff8151c6da>] __mutex_lock_common+0x5a/0x4b0
        [<ffffffff8151cc64>] mutex_lock_nested+0x44/0x50
        [<ffffffffa029c213>] ecryptfs_miscdev_read+0x143/0x470 [ecryptfs]
        [<ffffffff811887d3>] vfs_read+0xb3/0x180
        [<ffffffff811888ed>] sys_read+0x4d/0x90
        [<ffffffff81527d69>] system_call_fastpath+0x16/0x1b

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
alexelder pushed a commit that referenced this pull request May 21, 2013
…condition

commit 26c1917 upstream.

When holding the mmap_sem for reading, pmd_offset_map_lock should only
run on a pmd_t that has been read atomically from the pmdp pointer,
otherwise we may read only half of it leading to this crash.

PID: 11679  TASK: f06e8000  CPU: 3   COMMAND: "do_race_2_panic"
 #0 [f06a9dd8] crash_kexec at c049b5ec
 #1 [f06a9e2c] oops_end at c083d1c2
 #2 [f06a9e40] no_context at c0433ded
 #3 [f06a9e64] bad_area_nosemaphore at c043401a
 #4 [f06a9e6c] __do_page_fault at c0434493
 #5 [f06a9eec] do_page_fault at c083eb45
 #6 [f06a9f04] error_code (via page_fault) at c083c5d5
    EAX: 01fb470c EBX: fff35000 ECX: 00000003 EDX: 00000100 EBP:
    00000000
    DS:  007b     ESI: 9e201000 ES:  007b     EDI: 01fb4700 GS:  00e0
    CS:  0060     EIP: c083bc14 ERR: ffffffff EFLAGS: 00010246
 #7 [f06a9f38] _spin_lock at c083bc14
 #8 [f06a9f44] sys_mincore at c0507b7d
 #9 [f06a9fb0] system_call at c083becd
                         start           len
    EAX: ffffffda  EBX: 9e200000  ECX: 00001000  EDX: 6228537f
    DS:  007b      ESI: 00000000  ES:  007b      EDI: 003d0f00
    SS:  007b      ESP: 62285354  EBP: 62285388  GS:  0033
    CS:  0073      EIP: 00291416  ERR: 000000da  EFLAGS: 00000286

This should be a longstanding bug affecting x86 32bit PAE without THP.
Only archs with 64bit large pmd_t and 32bit unsigned long should be
affected.

With THP enabled the barrier() in pmd_none_or_trans_huge_or_clear_bad()
would partly hide the bug when the pmd transition from none to stable,
by forcing a re-read of the *pmd in pmd_offset_map_lock, but when THP is
enabled a new set of problem arises by the fact could then transition
freely in any of the none, pmd_trans_huge or pmd_trans_stable states.
So making the barrier in pmd_none_or_trans_huge_or_clear_bad()
unconditional isn't good idea and it would be a flakey solution.

This should be fully fixed by introducing a pmd_read_atomic that reads
the pmd in order with THP disabled, or by reading the pmd atomically
with cmpxchg8b with THP enabled.

Luckily this new race condition only triggers in the places that must
already be covered by pmd_none_or_trans_huge_or_clear_bad() so the fix
is localized there but this bug is not related to THP.

NOTE: this can trigger on x86 32bit systems with PAE enabled with more
than 4G of ram, otherwise the high part of the pmd will never risk to be
truncated because it would be zero at all times, in turn so hiding the
SMP race.

This bug was discovered and fully debugged by Ulrich, quote:

----
[..]
pmd_none_or_trans_huge_or_clear_bad() loads the content of edx and
eax.

    496 static inline int pmd_none_or_trans_huge_or_clear_bad(pmd_t
    *pmd)
    497 {
    498         /* depend on compiler for an atomic pmd read */
    499         pmd_t pmdval = *pmd;

                                // edi = pmd pointer
0xc0507a74 <sys_mincore+548>:   mov    0x8(%esp),%edi
...
                                // edx = PTE page table high address
0xc0507a84 <sys_mincore+564>:   mov    0x4(%edi),%edx
...
                                // eax = PTE page table low address
0xc0507a8e <sys_mincore+574>:   mov    (%edi),%eax

[..]

Please note that the PMD is not read atomically. These are two "mov"
instructions where the high order bits of the PMD entry are fetched
first. Hence, the above machine code is prone to the following race.

-  The PMD entry {high|low} is 0x0000000000000000.
   The "mov" at 0xc0507a84 loads 0x00000000 into edx.

-  A page fault (on another CPU) sneaks in between the two "mov"
   instructions and instantiates the PMD.

-  The PMD entry {high|low} is now 0x00000003fda38067.
   The "mov" at 0xc0507a8e loads 0xfda38067 into eax.
----

Reported-by: Ulrich Obergfell <uobergfe@redhat.com>
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: Larry Woodman <lwoodman@redhat.com>
Cc: Petr Matousek <pmatouse@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
alexelder pushed a commit that referenced this pull request May 21, 2013
commit 0fde0a8 upstream.

Fix:

BUG: sleeping function called from invalid context at kernel/workqueue.c:2547
in_atomic(): 1, irqs_disabled(): 0, pid: 629, name: wpa_supplicant
2 locks held by wpa_supplicant/629:
 #0:  (rtnl_mutex){+.+.+.}, at: [<c08b2b84>] rtnl_lock+0x14/0x20
 #1:  (&trigger->leddev_list_lock){.+.?..}, at: [<c0867f41>] led_trigger_event+0x21/0x80
Pid: 629, comm: wpa_supplicant Not tainted 3.3.0-0.rc3.git5.1.fc17.i686
Call Trace:
 [<c046a9f6>] __might_sleep+0x126/0x1d0
 [<c0457d6c>] wait_on_work+0x2c/0x1d0
 [<c045a09a>] __cancel_work_timer+0x6a/0x120
 [<c045a160>] cancel_delayed_work_sync+0x10/0x20
 [<f7dd3c22>] rtl8187_led_brightness_set+0x82/0xf0 [rtl8187]
 [<c0867f7c>] led_trigger_event+0x5c/0x80
 [<f7ff5e6d>] ieee80211_led_radio+0x1d/0x40 [mac80211]
 [<f7ff3583>] ieee80211_stop_device+0x13/0x230 [mac80211]

Removing _sync is ok, because if led_on work is currently running
it will be finished before led_off work start to perform, since
they are always queued on the same mac80211 local->workqueue.

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=795176

Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Acked-by: Larry Finger <Larry.Finger@lwfinger.net>
Acked-by: Hin-Tak Leung <htl10@users.sourceforge.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Cc: Josh Boyer <jwboyer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
alexelder pushed a commit that referenced this pull request May 21, 2013
commit d8adde1 upstream.

kswapd_stop() is called to destroy the kswapd work thread when all memory
of a NUMA node has been offlined.  But kswapd_stop() only terminates the
work thread without resetting NODE_DATA(nid)->kswapd to NULL.  The stale
pointer will prevent kswapd_run() from creating a new work thread when
adding memory to the memory-less NUMA node again.  Eventually the stale
pointer may cause invalid memory access.

An example stack dump as below. It's reproduced with 2.6.32, but latest
kernel has the same issue.

  BUG: unable to handle kernel NULL pointer dereference at (null)
  IP: [<ffffffff81051a94>] exit_creds+0x12/0x78
  PGD 0
  Oops: 0000 [#1] SMP
  last sysfs file: /sys/devices/system/memory/memory391/state
  CPU 11
  Modules linked in: cpufreq_conservative cpufreq_userspace cpufreq_powersave acpi_cpufreq microcode fuse loop dm_mod tpm_tis rtc_cmos i2c_i801 rtc_core tpm serio_raw pcspkr sg tpm_bios igb i2c_core iTCO_wdt rtc_lib mptctl iTCO_vendor_support button dca bnx2 usbhid hid uhci_hcd ehci_hcd usbcore sd_mod crc_t10dif edd ext3 mbcache jbd fan ide_pci_generic ide_core ata_generic ata_piix libata thermal processor thermal_sys hwmon mptsas mptscsih mptbase scsi_transport_sas scsi_mod
  Pid: 7949, comm: sh Not tainted 2.6.32.12-qiuxishi-5-default #92 Tecal RH2285
  RIP: 0010:exit_creds+0x12/0x78
  RSP: 0018:ffff8806044f1d78  EFLAGS: 00010202
  RAX: 0000000000000000 RBX: ffff880604f22140 RCX: 0000000000019502
  RDX: 0000000000000000 RSI: 0000000000000202 RDI: 0000000000000000
  RBP: ffff880604f22150 R08: 0000000000000000 R09: ffffffff81a4dc10
  R10: 00000000000032a0 R11: ffff880006202500 R12: 0000000000000000
  R13: 0000000000c40000 R14: 0000000000008000 R15: 0000000000000001
  FS:  00007fbc03d066f0(0000) GS:ffff8800282e0000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
  CR2: 0000000000000000 CR3: 000000060f029000 CR4: 00000000000006e0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
  Process sh (pid: 7949, threadinfo ffff8806044f0000, task ffff880603d7c600)
  Stack:
   ffff880604f22140 ffffffff8103aac5 ffff880604f22140 ffffffff8104d21e
   ffff880006202500 0000000000008000 0000000000c38000 ffffffff810bd5b1
   0000000000000000 ffff880603d7c600 00000000ffffdd29 0000000000000003
  Call Trace:
    __put_task_struct+0x5d/0x97
    kthread_stop+0x50/0x58
    offline_pages+0x324/0x3da
    memory_block_change_state+0x179/0x1db
    store_mem_state+0x9e/0xbb
    sysfs_write_file+0xd0/0x107
    vfs_write+0xad/0x169
    sys_write+0x45/0x6e
    system_call_fastpath+0x16/0x1b
  Code: ff 4d 00 0f 94 c0 84 c0 74 08 48 89 ef e8 1f fd ff ff 5b 5d 31 c0 41 5c c3 53 48 8b 87 20 06 00 00 48 89 fb 48 8b bf 18 06 00 00 <8b> 00 48 c7 83 18 06 00 00 00 00 00 00 f0 ff 0f 0f 94 c0 84 c0
  RIP  exit_creds+0x12/0x78
   RSP <ffff8806044f1d78>
  CR2: 0000000000000000

[akpm@linux-foundation.org: add pglist_data.kswapd locking comments]
Signed-off-by: Xishi Qiu <qiuxishi@huawei.com>
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Acked-by: David Rientjes <rientjes@google.com>
Reviewed-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
alexelder pushed a commit that referenced this pull request May 21, 2013
commit 29f6738 upstream.

memblock_free_reserved_regions() calls memblock_free(), but
memblock_free() would double reserved.regions too, so we could free the
old range for reserved.regions.

Also tj said there is another bug which could be related to this.

| I don't think we're saving any noticeable
| amount by doing this "free - give it to page allocator - reserve
| again" dancing.  We should just allocate regions aligned to page
| boundaries and free them later when memblock is no longer in use.

in that case, when DEBUG_PAGEALLOC, will get panic:

     memblock_free: [0x0000102febc080-0x0000102febf080] memblock_free_reserved_regions+0x37/0x39
  BUG: unable to handle kernel paging request at ffff88102febd948
  IP: [<ffffffff836a5774>] __next_free_mem_range+0x9b/0x155
  PGD 4826063 PUD cf67a067 PMD cf7fa067 PTE 800000102febd160
  Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
  CPU 0
  Pid: 0, comm: swapper Not tainted 3.5.0-rc2-next-20120614-sasha #447
  RIP: 0010:[<ffffffff836a5774>]  [<ffffffff836a5774>] __next_free_mem_range+0x9b/0x155

See the discussion at https://lkml.org/lkml/2012/6/13/469

So try to allocate with PAGE_SIZE alignment and free it later.

Reported-by: Sasha Levin <levinsasha928@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
alexelder pushed a commit that referenced this pull request May 21, 2013
commit 8d657eb upstream.

This can be trivially triggered from userspace by passing in something unexpected.

    kernel BUG at fs/locks.c:1468!
    invalid opcode: 0000 [#1] SMP
    RIP: 0010:generic_setlease+0xc2/0x100
    Call Trace:
      __vfs_setlease+0x35/0x40
      fcntl_setlease+0x76/0x150
      sys_fcntl+0x1c6/0x810
      system_call_fastpath+0x1a/0x1f

Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
alexelder pushed a commit that referenced this pull request May 21, 2013
commit 3cf003c upstream.

[The async read code was broadened to include uncached reads in 3.5, so
the mainline patch did not apply directly. This patch is just a backport
to account for that change.]

Jian found that when he ran fsx on a 32 bit arch with a large wsize the
process and one of the bdi writeback kthreads would sometimes deadlock
with a stack trace like this:

crash> bt
PID: 2789   TASK: f02edaa0  CPU: 3   COMMAND: "fsx"
 #0 [eed63cbc] schedule at c083c5b3
 #1 [eed63d80] kmap_high at c0500ec8
 #2 [eed63db0] cifs_async_writev at f7fabcd7 [cifs]
 #3 [eed63df0] cifs_writepages at f7fb7f5c [cifs]
 #4 [eed63e50] do_writepages at c04f3e32
 #5 [eed63e54] __filemap_fdatawrite_range at c04e152a
 #6 [eed63ea4] filemap_fdatawrite at c04e1b3e
 #7 [eed63eb4] cifs_file_aio_write at f7fa111a [cifs]
 #8 [eed63ecc] do_sync_write at c052d202
 #9 [eed63f74] vfs_write at c052d4ee
#10 [eed63f94] sys_write at c052df4c
#11 [eed63fb0] ia32_sysenter_target at c0409a98
    EAX: 00000004  EBX: 00000003  ECX: abd73b73  EDX: 012a65c6
    DS:  007b      ESI: 012a65c6  ES:  007b      EDI: 00000000
    SS:  007b      ESP: bf8db178  EBP: bf8db1f8  GS:  0033
    CS:  0073      EIP: 40000424  ERR: 00000004  EFLAGS: 00000246

Each task would kmap part of its address array before getting stuck, but
not enough to actually issue the write.

This patch fixes this by serializing the marshal_iov operations for
async reads and writes. The idea here is to ensure that cifs
aggressively tries to populate a request before attempting to fulfill
another one. As soon as all of the pages are kmapped for a request, then
we can unlock and allow another one to proceed.

There's no need to do this serialization on non-CONFIG_HIGHMEM arches
however, so optimize all of this out when CONFIG_HIGHMEM isn't set.

Reported-by: Jian Li <jiali@redhat.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
alexelder pushed a commit that referenced this pull request May 21, 2013
…d reasons

commit 5cf02d0 upstream.

We've had some reports of a deadlock where rpciod ends up with a stack
trace like this:

    PID: 2507   TASK: ffff88103691ab40  CPU: 14  COMMAND: "rpciod/14"
     #0 [ffff8810343bf2f0] schedule at ffffffff814dabd9
     #1 [ffff8810343bf3b8] nfs_wait_bit_killable at ffffffffa038fc04 [nfs]
     #2 [ffff8810343bf3c8] __wait_on_bit at ffffffff814dbc2f
     #3 [ffff8810343bf418] out_of_line_wait_on_bit at ffffffff814dbcd8
     #4 [ffff8810343bf488] nfs_commit_inode at ffffffffa039e0c1 [nfs]
     #5 [ffff8810343bf4f8] nfs_release_page at ffffffffa038bef6 [nfs]
     #6 [ffff8810343bf528] try_to_release_page at ffffffff8110c670
     #7 [ffff8810343bf538] shrink_page_list.clone.0 at ffffffff81126271
     #8 [ffff8810343bf668] shrink_inactive_list at ffffffff81126638
     #9 [ffff8810343bf818] shrink_zone at ffffffff8112788f
    #10 [ffff8810343bf8c8] do_try_to_free_pages at ffffffff81127b1e
    #11 [ffff8810343bf958] try_to_free_pages at ffffffff8112812f
    #12 [ffff8810343bfa08] __alloc_pages_nodemask at ffffffff8111fdad
    #13 [ffff8810343bfb28] kmem_getpages at ffffffff81159942
    #14 [ffff8810343bfb58] fallback_alloc at ffffffff8115a55a
    #15 [ffff8810343bfbd8] ____cache_alloc_node at ffffffff8115a2d9
    #16 [ffff8810343bfc38] kmem_cache_alloc at ffffffff8115b09b
    #17 [ffff8810343bfc78] sk_prot_alloc at ffffffff81411808
    #18 [ffff8810343bfcb8] sk_alloc at ffffffff8141197c
    #19 [ffff8810343bfce8] inet_create at ffffffff81483ba6
    #20 [ffff8810343bfd38] __sock_create at ffffffff8140b4a7
    #21 [ffff8810343bfd98] xs_create_sock at ffffffffa01f649b [sunrpc]
    #22 [ffff8810343bfdd8] xs_tcp_setup_socket at ffffffffa01f6965 [sunrpc]
    #23 [ffff8810343bfe38] worker_thread at ffffffff810887d0
    #24 [ffff8810343bfee8] kthread at ffffffff8108dd96
    #25 [ffff8810343bff48] kernel_thread at ffffffff8100c1ca

rpciod is trying to allocate memory for a new socket to talk to the
server. The VM ends up calling ->releasepage to get more memory, and it
tries to do a blocking commit. That commit can't succeed however without
a connected socket, so we deadlock.

Fix this by setting PF_FSTRANS on the workqueue task prior to doing the
socket allocation, and having nfs_release_page check for that flag when
deciding whether to do a commit call. Also, set PF_FSTRANS
unconditionally in rpc_async_schedule since that function can also do
allocations sometimes.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
alexelder pushed a commit that referenced this pull request May 21, 2013
commit a427b9e upstream.

Fix a number of bugs in the NFS idmapper code:

 (1) Only registered key types can be passed to the core keys code, so
     register the legacy idmapper key type.

     This is a requirement because the unregister function cleans up keys
     belonging to that key type so that there aren't dangling pointers to the
     module left behind - including the key->type pointer.

 (2) Rename the legacy key type.  You can't have two key types with the same
     name, and (1) would otherwise require that.

 (3) complete_request_key() must be called in the error path of
     nfs_idmap_legacy_upcall().

 (4) There is one idmap struct for each nfs_client struct.  This means that
     idmap->idmap_key_cons is shared without the use of a lock.  This is a
     problem because key_instantiate_and_link() - as called indirectly by
     idmap_pipe_downcall() - releases anyone waiting for the key to be
     instantiated.

     What happens is that idmap_pipe_downcall() running in the rpc.idmapd
     thread, releases the NFS filesystem in whatever thread that is running in
     to continue.  This may then make another idmapper call, overwriting
     idmap_key_cons before idmap_pipe_downcall() gets the chance to call
     complete_request_key().

     I *think* that reading idmap_key_cons only once, before
     key_instantiate_and_link() is called, and then caching the result in a
     variable is sufficient.

Bug (4) is the cause of:

BUG: unable to handle kernel NULL pointer dereference at           (null)
IP: [<          (null)>]           (null)
PGD 0
Oops: 0010 [#1] SMP
CPU 1
Modules linked in: ppdev parport_pc lp parport ip6table_filter ip6_tables ebtable_nat ebtables ipt_MASQUERADE iptable_nat nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_state nf_conntrack nfs fscache xt_CHECKSUM auth_rpcgss iptable_mangle nfs_acl bridge stp llc lockd be2iscsi iscsi_boot_sysfs bnx2i cnic uio cxgb4i cxgb4 cxgb3i libcxgbi cxgb3 mdio ib_iser rdma_cm ib_cm iw_cm ib_sa ib_mad ib_core ib_addr iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi snd_hda_codec_realtek snd_usb_audio snd_hda_intel snd_hda_codec snd_seq snd_pcm snd_hwdep snd_usbmidi_lib snd_rawmidi snd_timer uvcvideo videobuf2_core videodev media videobuf2_vmalloc snd_seq_device videobuf2_memops e1000e vhost_net iTCO_wdt joydev coretemp snd soundcore macvtap macvlan i2c_i801 snd_page_alloc tun iTCO_vendor_support microcode kvm_intel kvm sunrpc hid_logitech_dj usb_storage i915 drm_kms_helper drm i2c_algo_bit i2c_core video [last unloaded: scsi_wait_scan]
Pid: 1229, comm: rpc.idmapd Not tainted 3.4.2-1.fc16.x86_64 #1 Gateway DX4710-UB801A/G33M05G1
RIP: 0010:[<0000000000000000>]  [<          (null)>]           (null)
RSP: 0018:ffff8801a3645d40  EFLAGS: 00010246
RAX: ffff880077707e30 RBX: ffff880077707f50 RCX: ffff8801a18ccd80
RDX: 0000000000000006 RSI: ffff8801a3645e75 RDI: ffff880077707f50
RBP: ffff8801a3645d88 R08: ffff8801a430f9c0 R09: ffff8801a3645db0
R10: 000000000000000a R11: 0000000000000246 R12: ffff8801a18ccd80
R13: ffff8801a3645e75 R14: ffff8801a430f9c0 R15: 0000000000000006
FS:  00007fb6fb51a700(0000) GS:ffff8801afc80000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000001a49b0000 CR4: 00000000000027e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process rpc.idmapd (pid: 1229, threadinfo ffff8801a3644000, task ffff8801a3bf9710)
Stack:
 ffffffff81260878 ffff8801a3645db0 ffff8801a3645db0 ffff880077707a90
 ffff880077707f50 ffff8801a18ccd80 0000000000000006 ffff8801a3645e75
 ffff8801a430f9c0 ffff8801a3645dd8 ffffffff81260983 ffff8801a3645de8
Call Trace:
 [<ffffffff81260878>] ? __key_instantiate_and_link+0x58/0x100
 [<ffffffff81260983>] key_instantiate_and_link+0x63/0xa0
 [<ffffffffa057062b>] idmap_pipe_downcall+0x1cb/0x1e0 [nfs]
 [<ffffffffa0107f57>] rpc_pipe_write+0x67/0x90 [sunrpc]
 [<ffffffff8117f833>] vfs_write+0xb3/0x180
 [<ffffffff8117fb5a>] sys_write+0x4a/0x90
 [<ffffffff81600329>] system_call_fastpath+0x16/0x1b
Code:  Bad RIP value.
RIP  [<          (null)>]           (null)
 RSP <ffff8801a3645d40>
CR2: 0000000000000000

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Steve Dickson <steved@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
alexelder pushed a commit that referenced this pull request May 21, 2013
…list

[ Upstream commit 2eebc1e ]

A few days ago Dave Jones reported this oops:

[22766.294255] general protection fault: 0000 [#1] PREEMPT SMP
[22766.295376] CPU 0
[22766.295384] Modules linked in:
[22766.387137]  ffffffffa169f292 6b6b6b6b6b6b6b6b ffff880147c03a90
ffff880147c03a74
[22766.387135] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 00000000000
[22766.387136] Process trinity-watchdo (pid: 10896, threadinfo ffff88013e7d2000,
[22766.387137] Stack:
[22766.387140]  ffff880147c03a10
[22766.387140]  ffffffffa169f2b6
[22766.387140]  ffff88013ed95728
[22766.387143]  0000000000000002
[22766.387143]  0000000000000000
[22766.387143]  ffff880003fad062
[22766.387144]  ffff88013c120000
[22766.387144]
[22766.387145] Call Trace:
[22766.387145]  <IRQ>
[22766.387150]  [<ffffffffa169f292>] ? __sctp_lookup_association+0x62/0xd0
[sctp]
[22766.387154]  [<ffffffffa169f2b6>] __sctp_lookup_association+0x86/0xd0 [sctp]
[22766.387157]  [<ffffffffa169f597>] sctp_rcv+0x207/0xbb0 [sctp]
[22766.387161]  [<ffffffff810d4da8>] ? trace_hardirqs_off_caller+0x28/0xd0
[22766.387163]  [<ffffffff815827e3>] ? nf_hook_slow+0x133/0x210
[22766.387166]  [<ffffffff815902fc>] ? ip_local_deliver_finish+0x4c/0x4c0
[22766.387168]  [<ffffffff8159043d>] ip_local_deliver_finish+0x18d/0x4c0
[22766.387169]  [<ffffffff815902fc>] ? ip_local_deliver_finish+0x4c/0x4c0
[22766.387171]  [<ffffffff81590a07>] ip_local_deliver+0x47/0x80
[22766.387172]  [<ffffffff8158fd80>] ip_rcv_finish+0x150/0x680
[22766.387174]  [<ffffffff81590c54>] ip_rcv+0x214/0x320
[22766.387176]  [<ffffffff81558c07>] __netif_receive_skb+0x7b7/0x910
[22766.387178]  [<ffffffff8155856c>] ? __netif_receive_skb+0x11c/0x910
[22766.387180]  [<ffffffff810d423e>] ? put_lock_stats.isra.25+0xe/0x40
[22766.387182]  [<ffffffff81558f83>] netif_receive_skb+0x23/0x1f0
[22766.387183]  [<ffffffff815596a9>] ? dev_gro_receive+0x139/0x440
[22766.387185]  [<ffffffff81559280>] napi_skb_finish+0x70/0xa0
[22766.387187]  [<ffffffff81559cb5>] napi_gro_receive+0xf5/0x130
[22766.387218]  [<ffffffffa01c4679>] e1000_receive_skb+0x59/0x70 [e1000e]
[22766.387242]  [<ffffffffa01c5aab>] e1000_clean_rx_irq+0x28b/0x460 [e1000e]
[22766.387266]  [<ffffffffa01c9c18>] e1000e_poll+0x78/0x430 [e1000e]
[22766.387268]  [<ffffffff81559fea>] net_rx_action+0x1aa/0x3d0
[22766.387270]  [<ffffffff810a495f>] ? account_system_vtime+0x10f/0x130
[22766.387273]  [<ffffffff810734d0>] __do_softirq+0xe0/0x420
[22766.387275]  [<ffffffff8169826c>] call_softirq+0x1c/0x30
[22766.387278]  [<ffffffff8101db15>] do_softirq+0xd5/0x110
[22766.387279]  [<ffffffff81073bc5>] irq_exit+0xd5/0xe0
[22766.387281]  [<ffffffff81698b03>] do_IRQ+0x63/0xd0
[22766.387283]  [<ffffffff8168ee2f>] common_interrupt+0x6f/0x6f
[22766.387283]  <EOI>
[22766.387284]
[22766.387285]  [<ffffffff8168eed9>] ? retint_swapgs+0x13/0x1b
[22766.387285] Code: c0 90 5d c3 66 0f 1f 44 00 00 4c 89 c8 5d c3 0f 1f 00 55 48
89 e5 48 83
ec 20 48 89 5d e8 4c 89 65 f0 4c 89 6d f8 66 66 66 66 90 <0f> b7 87 98 00 00 00
48 89 fb
49 89 f5 66 c1 c0 08 66 39 46 02
[22766.387307]
[22766.387307] RIP
[22766.387311]  [<ffffffffa168a2c9>] sctp_assoc_is_match+0x19/0x90 [sctp]
[22766.387311]  RSP <ffff880147c039b0>
[22766.387142]  ffffffffa16ab120
[22766.599537] ---[ end trace 3f6dae82e37b17f5 ]---
[22766.601221] Kernel panic - not syncing: Fatal exception in interrupt

It appears from his analysis and some staring at the code that this is likely
occuring because an association is getting freed while still on the
sctp_assoc_hashtable.  As a result, we get a gpf when traversing the hashtable
while a freed node corrupts part of the list.

Nominally I would think that an mibalanced refcount was responsible for this,
but I can't seem to find any obvious imbalance.  What I did note however was
that the two places where we create an association using
sctp_primitive_ASSOCIATE (__sctp_connect and sctp_sendmsg), have failure paths
which free a newly created association after calling sctp_primitive_ASSOCIATE.
sctp_primitive_ASSOCIATE brings us into the sctp_sf_do_prm_asoc path, which
issues a SCTP_CMD_NEW_ASOC side effect, which in turn adds a new association to
the aforementioned hash table.  the sctp command interpreter that process side
effects has not way to unwind previously processed commands, so freeing the
association from the __sctp_connect or sctp_sendmsg error path would lead to a
freed association remaining on this hash table.

I've fixed this but modifying sctp_[un]hash_established to use hlist_del_init,
which allows us to proerly use hlist_unhashed to check if the node is on a
hashlist safely during a delete.  That in turn alows us to safely call
sctp_unhash_established in the __sctp_connect and sctp_sendmsg error paths
before freeing them, regardles of what the associations state is on the hash
list.

I noted, while I was doing this, that the __sctp_unhash_endpoint was using
hlist_unhsashed in a simmilar fashion, but never nullified any removed nodes
pointers to make that function work properly, so I fixed that up in a simmilar
fashion.

I attempted to test this using a virtual guest running the SCTP_RR test from
netperf in a loop while running the trinity fuzzer, both in a loop.  I wasn't
able to recreate the problem prior to this fix, nor was I able to trigger the
failure after (neither of which I suppose is suprising).  Given the trace above
however, I think its likely that this is what we hit.

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Reported-by: davej@redhat.com
CC: davej@redhat.com
CC: "David S. Miller" <davem@davemloft.net>
CC: Vlad Yasevich <vyasevich@gmail.com>
CC: Sridhar Samudrala <sri@us.ibm.com>
CC: linux-sctp@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
alexelder pushed a commit that referenced this pull request May 21, 2013
commit c5dff4f upstream.

On reboot or poweroff (machine_shutdown()) a call to smp_send_stop() is
made (to stop the others CPU's) when CONFIG_SMP=y.

arch/arm/kernel/process.c:

void machine_shutdown(void)
{
 #ifdef CONFIG_SMP
       smp_send_stop();
 #endif
}

smp_send_stop() calls the function pointer smp_cross_call(), which is set
on the smp_init_cpus() function for OMAP processors.

arch/arm/mach-omap2/omap-smp.c:

void __init smp_init_cpus(void)
{
...
	set_smp_cross_call(gic_raise_softirq);
...
}

But the ARM setup_arch() function only calls smp_init_cpus()
if CONFIG_SMP=y && is_smp().

arm/kernel/setup.c:

void __init setup_arch(char **cmdline_p)
{
...
 #ifdef CONFIG_SMP
	if (is_smp())
		smp_init_cpus();
 #endif
...
}

Newer OMAP CPU's are SMP machines so omap2plus_defconfig sets
CONFIG_SMP=y. Unfortunately on an OMAP UP machine is_smp()
returns false and smp_init_cpus() is never called and the
smp_cross_call() function remains NULL.

If the machine is rebooted or powered off, smp_send_stop() will
be called (since CONFIG_SMP=y) leading to the following error:

[   42.815551] Restarting system.
[   42.819030] Unable to handle kernel NULL pointer dereference at virtual address 00000000
[   42.827667] pgd = d7a74000
[   42.830566] [00000000] *pgd=96ce7831, *pte=00000000, *ppte=00000000
[   42.837249] Internal error: Oops: 80000007 [#1] SMP ARM
[   42.842773] Modules linked in:
[   42.846008] CPU: 0    Not tainted  (3.5.0-rc3-next-20120622-00002-g62e87ba-dirty #44)
[   42.854278] PC is at 0x0
[   42.856994] LR is at smp_send_stop+0x4c/0xe4
[   42.861511] pc : [<00000000>]    lr : [<c00183a4>]    psr: 60000013
[   42.861511] sp : d6c85e70  ip : 00000000  fp : 00000000
[   42.873626] r10: 00000000  r9 : d6c84000  r8 : 00000002
[   42.879150] r7 : c07235a0  r6 : c06dd2d0  r5 : 000f4241  r4 : d6c85e74
[   42.886047] r3 : 00000000  r2 : 00000000  r1 : 00000006  r0 : d6c85e74
[   42.892944] Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment user
[   42.900482] Control: 10c5387d  Table: 97a74019  DAC: 00000015
[   42.906555] Process reboot (pid: 1166, stack limit = 0xd6c842f8)
[   42.912902] Stack: (0xd6c85e70 to 0xd6c86000)
[   42.917510] 5e60:                                     c07235a0 00000000 00000000 d6c84000
[   42.926177] 5e80: 01234567 c00143d0 4321fedc c00511bc d6c85ebc 00000168 00000460 00000000
[   42.934814] 5ea0: c1017950 a0000013 c1017900 d8014390 d7ec3858 c0498e48 c1017950 00000000
[   42.943481] 5ec0: d6ddde10 d6c85f78 00000003 00000000 d6ddde10 d6c84000 00000000 00000000
[   42.952117] 5ee0: 00000002 00000000 00000000 c0088c88 00000002 00000000 00000000 c00f4b90
[   42.960784] 5f00: 00000000 d6c85ebc d8014390 d7e311c8 60000013 00000103 00000002 d6c84000
[   42.969421] 5f20: c00f3274 d6e00a00 00000001 60000013 d6c84000 00000000 00000000 c00895d4
[   42.978057] 5f40: 00000002 d8007c80 d781f000 c00f6150 d8010cc0 c00f3274 d781f000 d6c84000
[   42.986694] 5f60: c0013020 d6e00a00 00000001 20000010 0001257c ef000000 00000000 c00895d4
[   42.995361] 5f80: 00000002 00000001 00000003 00000000 00000001 00000003 00000000 00000058
[   43.003997] 5fa0: c00130c8 c0012f00 00000001 00000003 fee1dead 28121969 01234567 00000002
[   43.012634] 5fc0: 00000001 00000003 00000000 00000058 00012584 0001257c 00000001 00000000
[   43.021270] 5fe0: 000124bc bec5cc6c 00008f9c 4a2f7c40 20000010 fee1dead 00000000 00000000
[   43.029968] [<c00183a4>] (smp_send_stop+0x4c/0xe4) from [<c00143d0>] (machine_restart+0xc/0x4c)
[   43.039154] [<c00143d0>] (machine_restart+0xc/0x4c) from [<c00511bc>] (sys_reboot+0x144/0x1f0)
[   43.048278] [<c00511bc>] (sys_reboot+0x144/0x1f0) from [<c0012f00>] (ret_fast_syscall+0x0/0x3c)
[   43.057464] Code: bad PC value
[   43.060760] ---[ end trace c3988d1dd0b8f0fb ]---

Add a check so smp_cross_call() is only called when there is more than one CPU on-line.

Signed-off-by: Javier Martinez Canillas <javier at dowhile0.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
alexelder pushed a commit that referenced this pull request May 21, 2013
…bles

commit d833352 upstream.

If a process creates a large hugetlbfs mapping that is eligible for page
table sharing and forks heavily with children some of whom fault and
others which destroy the mapping then it is possible for page tables to
get corrupted.  Some teardowns of the mapping encounter a "bad pmd" and
output a message to the kernel log.  The final teardown will trigger a
BUG_ON in mm/filemap.c.

This was reproduced in 3.4 but is known to have existed for a long time
and goes back at least as far as 2.6.37.  It was probably was introduced
in 2.6.20 by [39dde65: shared page table for hugetlb page].  The messages
look like this;

[  ..........] Lots of bad pmd messages followed by this
[  127.164256] mm/memory.c:391: bad pmd ffff880412e04fe8(80000003de4000e7).
[  127.164257] mm/memory.c:391: bad pmd ffff880412e04ff0(80000003de6000e7).
[  127.164258] mm/memory.c:391: bad pmd ffff880412e04ff8(80000003de0000e7).
[  127.186778] ------------[ cut here ]------------
[  127.186781] kernel BUG at mm/filemap.c:134!
[  127.186782] invalid opcode: 0000 [#1] SMP
[  127.186783] CPU 7
[  127.186784] Modules linked in: af_packet cpufreq_conservative cpufreq_userspace cpufreq_powersave acpi_cpufreq mperf ext3 jbd dm_mod coretemp crc32c_intel usb_storage ghash_clmulni_intel aesni_intel i2c_i801 r8169 mii uas sr_mod cdrom sg iTCO_wdt iTCO_vendor_support shpchp serio_raw cryptd aes_x86_64 e1000e pci_hotplug dcdbas aes_generic container microcode ext4 mbcache jbd2 crc16 sd_mod crc_t10dif i915 drm_kms_helper drm i2c_algo_bit ehci_hcd ahci libahci usbcore rtc_cmos usb_common button i2c_core intel_agp video intel_gtt fan processor thermal thermal_sys hwmon ata_generic pata_atiixp libata scsi_mod
[  127.186801]
[  127.186802] Pid: 9017, comm: hugetlbfs-test Not tainted 3.4.0-autobuild #53 Dell Inc. OptiPlex 990/06D7TR
[  127.186804] RIP: 0010:[<ffffffff810ed6ce>]  [<ffffffff810ed6ce>] __delete_from_page_cache+0x15e/0x160
[  127.186809] RSP: 0000:ffff8804144b5c08  EFLAGS: 00010002
[  127.186810] RAX: 0000000000000001 RBX: ffffea000a5c9000 RCX: 00000000ffffffc0
[  127.186811] RDX: 0000000000000000 RSI: 0000000000000009 RDI: ffff88042dfdad00
[  127.186812] RBP: ffff8804144b5c18 R08: 0000000000000009 R09: 0000000000000003
[  127.186813] R10: 0000000000000000 R11: 000000000000002d R12: ffff880412ff83d8
[  127.186814] R13: ffff880412ff83d8 R14: 0000000000000000 R15: ffff880412ff83d8
[  127.186815] FS:  00007fe18ed2c700(0000) GS:ffff88042dce0000(0000) knlGS:0000000000000000
[  127.186816] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[  127.186817] CR2: 00007fe340000503 CR3: 0000000417a14000 CR4: 00000000000407e0
[  127.186818] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  127.186819] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[  127.186820] Process hugetlbfs-test (pid: 9017, threadinfo ffff8804144b4000, task ffff880417f803c0)
[  127.186821] Stack:
[  127.186822]  ffffea000a5c9000 0000000000000000 ffff8804144b5c48 ffffffff810ed83b
[  127.186824]  ffff8804144b5c48 000000000000138a 0000000000001387 ffff8804144b5c98
[  127.186825]  ffff8804144b5d48 ffffffff811bc925 ffff8804144b5cb8 0000000000000000
[  127.186827] Call Trace:
[  127.186829]  [<ffffffff810ed83b>] delete_from_page_cache+0x3b/0x80
[  127.186832]  [<ffffffff811bc925>] truncate_hugepages+0x115/0x220
[  127.186834]  [<ffffffff811bca43>] hugetlbfs_evict_inode+0x13/0x30
[  127.186837]  [<ffffffff811655c7>] evict+0xa7/0x1b0
[  127.186839]  [<ffffffff811657a3>] iput_final+0xd3/0x1f0
[  127.186840]  [<ffffffff811658f9>] iput+0x39/0x50
[  127.186842]  [<ffffffff81162708>] d_kill+0xf8/0x130
[  127.186843]  [<ffffffff81162812>] dput+0xd2/0x1a0
[  127.186845]  [<ffffffff8114e2d0>] __fput+0x170/0x230
[  127.186848]  [<ffffffff81236e0e>] ? rb_erase+0xce/0x150
[  127.186849]  [<ffffffff8114e3ad>] fput+0x1d/0x30
[  127.186851]  [<ffffffff81117db7>] remove_vma+0x37/0x80
[  127.186853]  [<ffffffff81119182>] do_munmap+0x2d2/0x360
[  127.186855]  [<ffffffff811cc639>] sys_shmdt+0xc9/0x170
[  127.186857]  [<ffffffff81410a39>] system_call_fastpath+0x16/0x1b
[  127.186858] Code: 0f 1f 44 00 00 48 8b 43 08 48 8b 00 48 8b 40 28 8b b0 40 03 00 00 85 f6 0f 88 df fe ff ff 48 89 df e8 e7 cb 05 00 e9 d2 fe ff ff <0f> 0b 55 83 e2 fd 48 89 e5 48 83 ec 30 48 89 5d d8 4c 89 65 e0
[  127.186868] RIP  [<ffffffff810ed6ce>] __delete_from_page_cache+0x15e/0x160
[  127.186870]  RSP <ffff8804144b5c08>
[  127.186871] ---[ end trace 7cbac5d1db69f426 ]---

The bug is a race and not always easy to reproduce.  To reproduce it I was
doing the following on a single socket I7-based machine with 16G of RAM.

$ hugeadm --pool-pages-max DEFAULT:13G
$ echo $((18*1048576*1024)) > /proc/sys/kernel/shmmax
$ echo $((18*1048576*1024)) > /proc/sys/kernel/shmall
$ for i in `seq 1 9000`; do ./hugetlbfs-test; done

On my particular machine, it usually triggers within 10 minutes but
enabling debug options can change the timing such that it never hits.
Once the bug is triggered, the machine is in trouble and needs to be
rebooted.  The machine will respond but processes accessing proc like "ps
aux" will hang due to the BUG_ON.  shutdown will also hang and needs a
hard reset or a sysrq-b.

The basic problem is a race between page table sharing and teardown.  For
the most part page table sharing depends on i_mmap_mutex.  In some cases,
it is also taking the mm->page_table_lock for the PTE updates but with
shared page tables, it is the i_mmap_mutex that is more important.

Unfortunately it appears to be also insufficient. Consider the following
situation

Process A					Process B
---------					---------
hugetlb_fault					shmdt
  						LockWrite(mmap_sem)
    						  do_munmap
						    unmap_region
						      unmap_vmas
						        unmap_single_vma
						          unmap_hugepage_range
      						            Lock(i_mmap_mutex)
							    Lock(mm->page_table_lock)
							    huge_pmd_unshare/unmap tables <--- (1)
							    Unlock(mm->page_table_lock)
      						            Unlock(i_mmap_mutex)
  huge_pte_alloc				      ...
    Lock(i_mmap_mutex)				      ...
    vma_prio_walk, find svma, spte		      ...
    Lock(mm->page_table_lock)			      ...
    share spte					      ...
    Unlock(mm->page_table_lock)			      ...
    Unlock(i_mmap_mutex)			      ...
  hugetlb_no_page									  <--- (2)
						      free_pgtables
						        unlink_file_vma
							hugetlb_free_pgd_range
						    remove_vma_list

In this scenario, it is possible for Process A to share page tables with
Process B that is trying to tear them down.  The i_mmap_mutex on its own
does not prevent Process A walking Process B's page tables.  At (1) above,
the page tables are not shared yet so it unmaps the PMDs.  Process A sets
up page table sharing and at (2) faults a new entry.  Process B then trips
up on it in free_pgtables.

This patch fixes the problem by adding a new function
__unmap_hugepage_range_final that is only called when the VMA is about to
be destroyed.  This function clears VM_MAYSHARE during
unmap_hugepage_range() under the i_mmap_mutex.  This makes the VMA
ineligible for sharing and avoids the race.  Superficially this looks like
it would then be vunerable to truncate and madvise issues but hugetlbfs
has its own truncate handlers so does not use unmap_mapping_range() and
does not support madvise(DONTNEED).

This should be treated as a -stable candidate if it is merged.

Test program is as follows. The test case was mostly written by Michal
Hocko with a few minor changes to reproduce this bug.

==== CUT HERE ====

static size_t huge_page_size = (2UL << 20);
static size_t nr_huge_page_A = 512;
static size_t nr_huge_page_B = 5632;

unsigned int get_random(unsigned int max)
{
	struct timeval tv;

	gettimeofday(&tv, NULL);
	srandom(tv.tv_usec);
	return random() % max;
}

static void play(void *addr, size_t size)
{
	unsigned char *start = addr,
		      *end = start + size,
		      *a;
	start += get_random(size/2);

	/* we could itterate on huge pages but let's give it more time. */
	for (a = start; a < end; a += 4096)
		*a = 0;
}

int main(int argc, char **argv)
{
	key_t key = IPC_PRIVATE;
	size_t sizeA = nr_huge_page_A * huge_page_size;
	size_t sizeB = nr_huge_page_B * huge_page_size;
	int shmidA, shmidB;
	void *addrA = NULL, *addrB = NULL;
	int nr_children = 300, n = 0;

	if ((shmidA = shmget(key, sizeA, IPC_CREAT|SHM_HUGETLB|0660)) == -1) {
		perror("shmget:");
		return 1;
	}

	if ((addrA = shmat(shmidA, addrA, SHM_R|SHM_W)) == (void *)-1UL) {
		perror("shmat");
		return 1;
	}
	if ((shmidB = shmget(key, sizeB, IPC_CREAT|SHM_HUGETLB|0660)) == -1) {
		perror("shmget:");
		return 1;
	}

	if ((addrB = shmat(shmidB, addrB, SHM_R|SHM_W)) == (void *)-1UL) {
		perror("shmat");
		return 1;
	}

fork_child:
	switch(fork()) {
		case 0:
			switch (n%3) {
			case 0:
				play(addrA, sizeA);
				break;
			case 1:
				play(addrB, sizeB);
				break;
			case 2:
				break;
			}
			break;
		case -1:
			perror("fork:");
			break;
		default:
			if (++n < nr_children)
				goto fork_child;
			play(addrA, sizeA);
			break;
	}
	shmdt(addrA);
	shmdt(addrB);
	do {
		wait(NULL);
	} while (--n > 0);
	shmctl(shmidA, IPC_RMID, NULL);
	shmctl(shmidB, IPC_RMID, NULL);
	return 0;
}

[akpm@linux-foundation.org: name the declaration's args, fix CONFIG_HUGETLBFS=n build]
Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
alexelder pushed a commit that referenced this pull request May 21, 2013
commit a2367db upstream.

With the new i.MX clock infrastructure we need to request the dma clocks
seperately: ahb and ipg clocks.

This fixes the following kernel crash and make audio to be functional again:

root@freescale /home$ aplay audio48k16S.wav
Playing WAVE 'audio48k16S.wav' : Signed 16 bit Little Endian, Rate 48000 Hz, Stereo
Unable to handle kernel NULL pointer dereference at virtual address 00000000
pgd = c7b74000
[00000000] *pgd=a7bb5831, *pte=00000000, *ppte=00000000
Internal error: Oops: 17 [#1] PREEMPT ARM
Modules linked in:
CPU: 0    Not tainted  (3.5.0-rc5-next-20120702-00007-g3028b64 #1128)
PC is at snd_dmaengine_pcm_get_chan+0x8/0x10
LR is at snd_imx_pcm_hw_params+0x18/0xdc
pc : [<c02d3cf8>]    lr : [<c02e95ec>]    psr: a0000013
sp : c7b45e30  ip : ffffffff  fp : c7ae58e0
r10: 00000000  r9 : c7ae981c  r8 : c7b88800
r7 : c7ae5a60  r6 : c7ae5b20  r5 : c7ae9810  r4 : c7afa060
r3 : 00000000  r2 : 00000001  r1 : c7b88800  r0 : c7afa060
Flags: NzCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment user
Control: 0005317f  Table: a7b74000  DAC: 00000015
Process aplay (pid: 701, stack limit = 0xc7b44270)
Stack: (0xc7b45e30 to 0xc7b46000)
5e20:                                     00100000 00000029 c7b88800 c02db870
5e40: c7ae5a60 c02d4594 00000010 01ae5a60 c7ae5a60 c7ae9810 c7ae9810 c7afa060
5e60: c7ae5b20 c7ae5a60 c7b88800 c02e3ef0 c02e3e08 c7b1e400 c7afa060 c7b88800
5e80: 00000000 c0014da8 c7b44000 00000000 bec566ac c02cd400 c7afa060 c7afa060
5ea0: bec56800 c7b88800 c0014da8 c02cdd7c c04ee710 c04ee7b8 00000003 c005fc74
5ec0: 00000000 7fffffff c7b45f00 c7afa060 c7b67420 c7ba3070 00000004 c0014da8
5ee0: c7b44000 00000000 bec566ac c02ced88 c04e95f8 b6f5ab04 c7b45fb0 0145a468
5f00: 0145a600 bec566bc bec56800 c7b67420 c7ba3070 c00d499c c7b45f18 c7b45f18
5f20: 0000001a 00000004 00000001 c7b44000 c0527f40 00000009 00000008 00000000
5f40: c7b44000 c002c9ec 00000001 c04f0ab0 c04ebec0 00000101 00000000 0000000a
5f60: 60000093 c7b67420 bec56800 c25c4111 00000004 c0014da8 c7b44000 00000000
5f80: bec566ac c00d4f38 b6ffb658 00000000 c0522d80 0145a468 b6fd5000 0145a418
5fa0: 00000036 c0014c00 0145a468 b6fd5000 00000004 c25c4111 bec56800 00020001
5fc0: 0145a468 b6fd5000 0145a418 00000036 0145a468 0145a600 bec566bc bec566ac
5fe0: 0145a468 bec56388 b6f65ce4 b6dcebec 20000010 00000004 00000000 00000000
[<c02d3cf8>] (snd_dmaengine_pcm_get_chan+0x8/0x10) from [<c02e95ec>] (snd_imx_pcm_hw_params+0x18/0xdc)
[<c02e95ec>] (snd_imx_pcm_hw_params+0x18/0xdc) from [<c02e3ef0>] (soc_pcm_hw_params+0xe8/0x1f0)
[<c02e3ef0>] (soc_pcm_hw_params+0xe8/0x1f0) from [<c02cd400>] (snd_pcm_hw_params+0x124/0x474)
[<c02cd400>] (snd_pcm_hw_params+0x124/0x474) from [<c02cdd7c>] (snd_pcm_common_ioctl1+0x4b4/0xf74)
[<c02cdd7c>] (snd_pcm_common_ioctl1+0x4b4/0xf74) from [<c02ced88>] (snd_pcm_playback_ioctl1+0x30/0x510)
[<c02ced88>] (snd_pcm_playback_ioctl1+0x30/0x510) from [<c00d499c>] (do_vfs_ioctl+0x80/0x5e4)
[<c00d499c>] (do_vfs_ioctl+0x80/0x5e4) from [<c00d4f38>] (sys_ioctl+0x38/0x60)
[<c00d4f38>] (sys_ioctl+0x38/0x60) from [<c0014c00>] (ret_fast_syscall+0x0/0x2c)
Code: e593000c e12fff1e e59030a0 e59330bc (e5930000)
---[ end trace fa518c8ba3a74e97 ]--

Reported-by: Javier Martin <javier.martin@vista-silicon.com>
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
alexelder pushed a commit that referenced this pull request May 21, 2013
commit eb48c07 upstream.

Each page mapped in a process's address space must be correctly
accounted for in _mapcount.  Normally the rules for this are
straightforward but hugetlbfs page table sharing is different.  The page
table pages at the PMD level are reference counted while the mapcount
remains the same.

If this accounting is wrong, it causes bugs like this one reported by
Larry Woodman:

  kernel BUG at mm/filemap.c:135!
  invalid opcode: 0000 [#1] SMP
  CPU 22
  Modules linked in: bridge stp llc sunrpc binfmt_misc dcdbas microcode pcspkr acpi_pad acpi]
  Pid: 18001, comm: mpitest Tainted: G        W    3.3.0+ #4 Dell Inc. PowerEdge R620/07NDJ2
  RIP: 0010:[<ffffffff8112cfed>]  [<ffffffff8112cfed>] __delete_from_page_cache+0x15d/0x170
  Process mpitest (pid: 18001, threadinfo ffff880428972000, task ffff880428b5cc20)
  Call Trace:
    delete_from_page_cache+0x40/0x80
    truncate_hugepages+0x115/0x1f0
    hugetlbfs_evict_inode+0x18/0x30
    evict+0x9f/0x1b0
    iput_final+0xe3/0x1e0
    iput+0x3e/0x50
    d_kill+0xf8/0x110
    dput+0xe2/0x1b0
    __fput+0x162/0x240

During fork(), copy_hugetlb_page_range() detects if huge_pte_alloc()
shared page tables with the check dst_pte == src_pte.  The logic is if
the PMD page is the same, they must be shared.  This assumes that the
sharing is between the parent and child.  However, if the sharing is
with a different process entirely then this check fails as in this
diagram:

  parent
    |
    ------------>pmd
                 src_pte----------> data page
                                        ^
  other--------->pmd--------------------|
                  ^
  child-----------|
                 dst_pte

For this situation to occur, it must be possible for Parent and Other to
have faulted and failed to share page tables with each other.  This is
possible due to the following style of race.

  PROC A                                          PROC B
  copy_hugetlb_page_range                         copy_hugetlb_page_range
    src_pte == huge_pte_offset                      src_pte == huge_pte_offset
    !src_pte so no sharing                          !src_pte so no sharing

  (time passes)

  hugetlb_fault                                   hugetlb_fault
    huge_pte_alloc                                  huge_pte_alloc
      huge_pmd_share                                 huge_pmd_share
        LOCK(i_mmap_mutex)
        find nothing, no sharing
        UNLOCK(i_mmap_mutex)
                                                      LOCK(i_mmap_mutex)
                                                      find nothing, no sharing
                                                      UNLOCK(i_mmap_mutex)
      pmd_alloc                                       pmd_alloc
      LOCK(instantiation_mutex)
      fault
      UNLOCK(instantiation_mutex)
                                                  LOCK(instantiation_mutex)
                                                  fault
                                                  UNLOCK(instantiation_mutex)

These two processes are not poing to the same data page but are not
sharing page tables because the opportunity was missed.  When either
process later forks, the src_pte == dst pte is potentially insufficient.
As the check falls through, the wrong PTE information is copied in
(harmless but wrong) and the mapcount is bumped for a page mapped by a
shared page table leading to the BUG_ON.

This patch addresses the issue by moving pmd_alloc into huge_pmd_share
which guarantees that the shared pud is populated in the same critical
section as pmd.  This also means that huge_pte_offset test in
huge_pmd_share is serialized correctly now which in turn means that the
success of the sharing will be higher as the racing tasks see the pud
and pmd populated together.

Race identified and changelog written mostly by Mel Gorman.

{akpm@linux-foundation.org: attempt to make the huge_pmd_share() comment comprehensible, clean up coding style]
Reported-by: Larry Woodman <lwoodman@redhat.com>
Tested-by: Larry Woodman <lwoodman@redhat.com>
Reviewed-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Ken Chen <kenchen@google.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Hillf Danton <dhillf@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
alexelder pushed a commit that referenced this pull request May 21, 2013
commit bea6832 upstream.

On architectures where cputime_t is 64 bit type, is possible to trigger
divide by zero on do_div(temp, (__force u32) total) line, if total is a
non zero number but has lower 32 bit's zeroed. Removing casting is not
a good solution since some do_div() implementations do cast to u32
internally.

This problem can be triggered in practice on very long lived processes:

  PID: 2331   TASK: ffff880472814b00  CPU: 2   COMMAND: "oraagent.bin"
   #0 [ffff880472a51b70] machine_kexec at ffffffff8103214b
   #1 [ffff880472a51bd0] crash_kexec at ffffffff810b91c2
   #2 [ffff880472a51ca0] oops_end at ffffffff814f0b00
   #3 [ffff880472a51cd0] die at ffffffff8100f26b
   #4 [ffff880472a51d00] do_trap at ffffffff814f03f4
   #5 [ffff880472a51d60] do_divide_error at ffffffff8100cfff
   #6 [ffff880472a51e00] divide_error at ffffffff8100be7b
      [exception RIP: thread_group_times+0x56]
      RIP: ffffffff81056a16  RSP: ffff880472a51eb8  RFLAGS: 00010046
      RAX: bc3572c9fe12d194  RBX: ffff880874150800  RCX: 0000000110266fad
      RDX: 0000000000000000  RSI: ffff880472a51eb8  RDI: 001038ae7d9633dc
      RBP: ffff880472a51ef8   R8: 00000000b10a3a64   R9: ffff880874150800
      R10: 00007fcba27ab680  R11: 0000000000000202  R12: ffff880472a51f08
      R13: ffff880472a51f10  R14: 0000000000000000  R15: 0000000000000007
      ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
   #7 [ffff880472a51f00] do_sys_times at ffffffff8108845d
   #8 [ffff880472a51f40] sys_times at ffffffff81088524
   #9 [ffff880472a51f80] system_call_fastpath at ffffffff8100b0f2
      RIP: 0000003808caac3a  RSP: 00007fcba27ab6d8  RFLAGS: 00000202
      RAX: 0000000000000064  RBX: ffffffff8100b0f2  RCX: 0000000000000000
      RDX: 00007fcba27ab6e0  RSI: 000000000076d58e  RDI: 00007fcba27ab6e0
      RBP: 00007fcba27ab700   R8: 0000000000000020   R9: 000000000000091b
      R10: 00007fcba27ab680  R11: 0000000000000202  R12: 00007fff9ca41940
      R13: 0000000000000000  R14: 00007fcba27ac9c0  R15: 00007fff9ca41940
      ORIG_RAX: 0000000000000064  CS: 0033  SS: 002b

Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20120808092714.GA3580@redhat.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
alexelder pushed a commit that referenced this pull request May 21, 2013
…lock

[ Upstream commit 4acd494 ]

Cong Wang reports that lockdep detected suspicious RCU usage while
enabling IPV6 forwarding:

 [ 1123.310275] ===============================
 [ 1123.442202] [ INFO: suspicious RCU usage. ]
 [ 1123.558207] 3.6.0-rc1+ #109 Not tainted
 [ 1123.665204] -------------------------------
 [ 1123.768254] include/linux/rcupdate.h:430 Illegal context switch in RCU read-side critical section!
 [ 1123.992320]
 [ 1123.992320] other info that might help us debug this:
 [ 1123.992320]
 [ 1124.307382]
 [ 1124.307382] rcu_scheduler_active = 1, debug_locks = 0
 [ 1124.522220] 2 locks held by sysctl/5710:
 [ 1124.648364]  #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff81768498>] rtnl_trylock+0x15/0x17
 [ 1124.882211]  #1:  (rcu_read_lock){.+.+.+}, at: [<ffffffff81871df8>] rcu_lock_acquire+0x0/0x29
 [ 1125.085209]
 [ 1125.085209] stack backtrace:
 [ 1125.332213] Pid: 5710, comm: sysctl Not tainted 3.6.0-rc1+ #109
 [ 1125.441291] Call Trace:
 [ 1125.545281]  [<ffffffff8109d915>] lockdep_rcu_suspicious+0x109/0x112
 [ 1125.667212]  [<ffffffff8107c240>] rcu_preempt_sleep_check+0x45/0x47
 [ 1125.781838]  [<ffffffff8107c260>] __might_sleep+0x1e/0x19b
[...]
 [ 1127.445223]  [<ffffffff81757ac5>] call_netdevice_notifiers+0x4a/0x4f
[...]
 [ 1127.772188]  [<ffffffff8175e125>] dev_disable_lro+0x32/0x6b
 [ 1127.885174]  [<ffffffff81872d26>] dev_forward_change+0x30/0xcb
 [ 1128.013214]  [<ffffffff818738c4>] addrconf_forward_change+0x85/0xc5
[...]

addrconf_forward_change() uses RCU iteration over the netdev list,
which is unnecessary since it already holds the RTNL lock.  We also
cannot reasonably require netdevice notifier functions not to sleep.

Reported-by: Cong Wang <amwang@redhat.com>
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
alexelder pushed a commit that referenced this pull request May 21, 2013
commit a849088 upstream.

Murali Nalajala reports a regression that ioremapping address zero
results in an oops dump:

Unable to handle kernel paging request at virtual address fa200000
pgd = d4f80000
[fa200000] *pgd=00000000
Internal error: Oops: 5 [#1] PREEMPT SMP ARM
Modules linked in:
CPU: 0    Tainted: G        W (3.4.0-g3b5f728-00009-g638207a #13)
PC is at msm_pm_config_rst_vector_before_pc+0x8/0x30
LR is at msm_pm_boot_config_before_pc+0x18/0x20
pc : [<c0078f84>]    lr : [<c007903c>]    psr: a0000093
sp : c0837ef0  ip : cfe00000  fp : 0000000d
r10: da7efc17  r9 : 225c4278  r8 : 00000006
r7 : 0003c000  r6 : c085c824  r5 : 00000001  r4 : fa101000
r3 : fa200000  r2 : c095080c  r1 : 002250fc  r0 : 00000000
Flags: NzCv  IRQs off  FIQs on  Mode SVC_32  ISA ARM Segment kernel
Control: 10c5387d  Table: 25180059  DAC: 00000015
[<c0078f84>] (msm_pm_config_rst_vector_before_pc+0x8/0x30) from [<c007903c>] (msm_pm_boot_config_before_pc+0x18/0x20)
[<c007903c>] (msm_pm_boot_config_before_pc+0x18/0x20) from [<c007a55c>] (msm_pm_power_collapse+0x410/0xb04)
[<c007a55c>] (msm_pm_power_collapse+0x410/0xb04) from [<c007b17c>] (arch_idle+0x294/0x3e0)
[<c007b17c>] (arch_idle+0x294/0x3e0) from [<c000eed8>] (default_idle+0x18/0x2c)
[<c000eed8>] (default_idle+0x18/0x2c) from [<c000f254>] (cpu_idle+0x90/0xe4)
[<c000f254>] (cpu_idle+0x90/0xe4) from [<c057231c>] (rest_init+0x88/0xa0)
[<c057231c>] (rest_init+0x88/0xa0) from [<c07ff890>] (start_kernel+0x3a8/0x40c)
Code: c0704256 e12fff1e e59f2020 e5923000 (e5930000)

This is caused by the 'reserved' entries which we insert (see
19b52ab - ARM: 7438/1: fill possible PMD empty section gaps)
which get matched for physical address zero.

Resolve this by marking these reserved entries with a different flag.

Tested-by: Murali Nalajala <mnalajal@codeaurora.org>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
alexelder pushed a commit that referenced this pull request May 21, 2013
commit 8d54db7 upstream.

The hypervisor is in charge of allocating the proper "NUMA" memory
and dealing with the CPU scheduler to keep them bound to the proper
NUMA node. The PV guests (and PVHVM) have no inkling of where they
run and do not need to know that right now. In the future we will
need to inject NUMA configuration data (if a guest spans two or more
NUMA nodes) so that the kernel can make the right choices. But those
patches are not yet present.

In the meantime, disable the NUMA capability in the PV guest, which
also fixes a bootup issue. Andre says:

"we see Dom0 crashes due to the kernel detecting the NUMA topology not
by ACPI, but directly from the northbridge (CONFIG_AMD_NUMA).

This will detect the actual NUMA config of the physical machine, but
will crash about the mismatch with Dom0's virtual memory. Variation of
the theme: Dom0 sees what it's not supposed to see.

This happens with the said config option enabled and on a machine where
this scanning is still enabled (K8 and Fam10h, not Bulldozer class)

We have this dump then:
NUMA: Warning: node ids are out of bound, from=-1 to=-1 distance=10
Scanning NUMA topology in Northbridge 24
Number of physical nodes 4
Node 0 MemBase 0000000000000000 Limit 0000000040000000
Node 1 MemBase 0000000040000000 Limit 0000000138000000
Node 2 MemBase 0000000138000000 Limit 00000001f8000000
Node 3 MemBase 00000001f8000000 Limit 0000000238000000
Initmem setup node 0 0000000000000000-0000000040000000
  NODE_DATA [000000003ffd9000 - 000000003fffffff]
Initmem setup node 1 0000000040000000-0000000138000000
  NODE_DATA [0000000137fd9000 - 0000000137ffffff]
Initmem setup node 2 0000000138000000-00000001f8000000
  NODE_DATA [00000001f095e000 - 00000001f0984fff]
Initmem setup node 3 00000001f8000000-0000000238000000
Cannot find 159744 bytes in node 3
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: [<ffffffff81d220e6>] __alloc_bootmem_node+0x43/0x96
Pid: 0, comm: swapper Not tainted 3.3.6 #1 AMD Dinar/Dinar
RIP: e030:[<ffffffff81d220e6>]  [<ffffffff81d220e6>] __alloc_bootmem_node+0x43/0x96
.. snip..
  [<ffffffff81d23024>] sparse_early_usemaps_alloc_node+0x64/0x178
  [<ffffffff81d23348>] sparse_init+0xe4/0x25a
  [<ffffffff81d16840>] paging_init+0x13/0x22
  [<ffffffff81d07fbb>] setup_arch+0x9c6/0xa9b
  [<ffffffff81683954>] ? printk+0x3c/0x3e
  [<ffffffff81d01a38>] start_kernel+0xe5/0x468
  [<ffffffff81d012cf>] x86_64_start_reservations+0xba/0xc1
  [<ffffffff81007153>] ? xen_setup_runstate_info+0x2c/0x36
  [<ffffffff81d050ee>] xen_start_kernel+0x565/0x56c
"

so we just disable NUMA scanning by setting numa_off=1.

Reported-and-Tested-by: Andre Przywara <andre.przywara@amd.com>
Acked-by: Andre Przywara <andre.przywara@amd.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
alexelder pushed a commit that referenced this pull request May 21, 2013
commit ab04c8b upstream.

This patch fixes an oops which occurs when unloading the driver, while the
network interface is still up. The problem is that first the io mapping is
teared own, then the CAN device is unregistered, resulting in accessing the
hardware's iomem:

[  172.744232] Unable to handle kernel paging request at virtual address c88b0040
[  172.752441] pgd = c7be4000
[  172.755645] [c88b0040] *pgd=87821811, *pte=00000000, *ppte=00000000
[  172.762207] Internal error: Oops: 807 [#1] PREEMPT ARM
[  172.767517] Modules linked in: ti_hecc(-) can_dev
[  172.772430] CPU: 0    Not tainted  (3.5.0alpha-00037-g3554cc0 #126)
[  172.778961] PC is at ti_hecc_close+0xb0/0x100 [ti_hecc]
[  172.784423] LR is at __dev_close_many+0x90/0xc0
[  172.789123] pc : [<bf00c768>]    lr : [<c033be58>]    psr: 60000013
[  172.789123] sp : c5c1de68  ip : 00040081  fp : 00000000
[  172.801025] r10: 00000001  r9 : c5c1c000  r8 : 00100100
[  172.806457] r7 : c5d0a48c  r6 : c5d0a400  r5 : 00000000  r4 : c5d0a000
[  172.813232] r3 : c88b0000  r2 : 00000001  r1 : c5d0a000  r0 : c5d0a000
[  172.820037] Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment user
[  172.827423] Control: 10c5387d  Table: 87be4019  DAC: 00000015
[  172.833404] Process rmmod (pid: 600, stack limit = 0xc5c1c2f0)
[  172.839447] Stack: (0xc5c1de68 to 0xc5c1e000)
[  172.843994] de60:                   bf00c6b8 c5c1dec8 c5d0a000 c5d0a000 00200200 c033be58
[  172.852478] de80: c5c1de44 c5c1dec8 c5c1dec8 c033bf2c c5c1de90 c5c1de90 c5d0a084 c5c1de44
[  172.860992] dea0: c5c1dec8 c033c098 c061d3dc c5d0a000 00000000 c05edf28 c05edb34 c000d724
[  172.869476] dec0: 00000000 c033c2f8 c5d0a084 c5d0a084 00000000 c033c370 00000000 c5d0a000
[  172.877990] dee0: c05edb00 c033c3b8 c5d0a000 bf00d3ac c05edb00 bf00d7c8 bf00d7c8 c02842dc
[  172.886474] df00: c02842c8 c0282f90 c5c1c000 c05edb00 bf00d7c8 c0283668 bf00d7c8 00000000
[  172.894989] df20: c0611f98 befe2f80 c000d724 c0282d10 bf00d804 00000000 00000013 c0068a8c
[  172.903472] df40: c5c538e8 685f6974 00636365 c61571a8 c5cb9980 c61571a8 c6158a20 c00c9bc4
[  172.911987] df60: 00000000 00000000 c5cb9980 00000000 c5cb9980 00000000 c7823680 00000006
[  172.920471] df80: bf00d804 00000880 c5c1df8c 00000000 000d4267 befe2f80 00000001 b6d90068
[  172.928985] dfa0: 00000081 c000d5a0 befe2f80 00000001 befe2f80 00000880 b6d90008 00000008
[  172.937469] dfc0: befe2f80 00000001 b6d90068 00000081 00000001 00000000 befe2eac 00000000
[  172.945983] dfe0: 00000000 befe2b18 00023ba4 b6e6addc 60000010 befe2f80 a8e00190 86d2d344
[  172.954498] [<bf00c768>] (ti_hecc_close+0xb0/0x100 [ti_hecc]) from [<c033be58>] (__dev__registered_many+0xc0/0x2a0)
[  172.984161] [<c033c098>] (rollback_registered_many+0xc0/0x2a0) from [<c033c2f8>] (rollback_registered+0x20/0x30)
[  172.994750] [<c033c2f8>] (rollback_registered+0x20/0x30) from [<c033c370>] (unregister_netdevice_queue+0x68/0x98)
[  173.005401] [<c033c370>] (unregister_netdevice_queue+0x68/0x98) from [<c033c3b8>] (unregister_netdev+0x18/0x20)
[  173.015899] [<c033c3b8>] (unregister_netdev+0x18/0x20) from [<bf00d3ac>] (ti_hecc_remove+0x60/0x80 [ti_hecc])
[  173.026245] [<bf00d3ac>] (ti_hecc_remove+0x60/0x80 [ti_hecc]) from [<c02842dc>] (platform_drv_remove+0x14/0x18)
[  173.036712] [<c02842dc>] (platform_drv_remove+0x14/0x18) from [<c0282f90>] (__device_release_driver+0x7c/0xbc)

Tested-by: Jan Luebbe <jlu@pengutronix.de>
Cc: Anant Gole <anantgole@ti.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
alexelder pushed a commit that referenced this pull request May 21, 2013
commit a85d0d7 upstream.

When call_crda() is called we kick off a witch hunt search
for the same regulatory domain on our internal regulatory
database and that work gets kicked off on a workqueue, this
is done while the cfg80211_mutex is held. If that workqueue
kicks off it will first lock reg_regdb_search_mutex and
later cfg80211_mutex but to ensure two CPUs will not contend
against cfg80211_mutex the right thing to do is to have the
reg_regdb_search() wait until the cfg80211_mutex is let go.

The lockdep report is pasted below.

cfg80211: Calling CRDA to update world regulatory domain

======================================================
[ INFO: possible circular locking dependency detected ]
3.3.8 #3 Tainted: G           O
-------------------------------------------------------
kworker/0:1/235 is trying to acquire lock:
 (cfg80211_mutex){+.+...}, at: [<816468a4>] set_regdom+0x78c/0x808 [cfg80211]

but task is already holding lock:
 (reg_regdb_search_mutex){+.+...}, at: [<81646828>] set_regdom+0x710/0x808 [cfg80211]

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #2 (reg_regdb_search_mutex){+.+...}:
       [<800a8384>] lock_acquire+0x60/0x88
       [<802950a8>] mutex_lock_nested+0x54/0x31c
       [<81645778>] is_world_regdom+0x9f8/0xc74 [cfg80211]

-> #1 (reg_mutex#2){+.+...}:
       [<800a8384>] lock_acquire+0x60/0x88
       [<802950a8>] mutex_lock_nested+0x54/0x31c
       [<8164539c>] is_world_regdom+0x61c/0xc74 [cfg80211]

-> #0 (cfg80211_mutex){+.+...}:
       [<800a77b8>] __lock_acquire+0x10d4/0x17bc
       [<800a8384>] lock_acquire+0x60/0x88
       [<802950a8>] mutex_lock_nested+0x54/0x31c
       [<816468a4>] set_regdom+0x78c/0x808 [cfg80211]

other info that might help us debug this:

Chain exists of:
  cfg80211_mutex --> reg_mutex#2 --> reg_regdb_search_mutex

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(reg_regdb_search_mutex);
                               lock(reg_mutex#2);
                               lock(reg_regdb_search_mutex);
  lock(cfg80211_mutex);

 *** DEADLOCK ***

3 locks held by kworker/0:1/235:
 #0:  (events){.+.+..}, at: [<80089a00>] process_one_work+0x230/0x460
 #1:  (reg_regdb_work){+.+...}, at: [<80089a00>] process_one_work+0x230/0x460
 #2:  (reg_regdb_search_mutex){+.+...}, at: [<81646828>] set_regdom+0x710/0x808 [cfg80211]

stack backtrace:
Call Trace:
[<80290fd4>] dump_stack+0x8/0x34
[<80291bc4>] print_circular_bug+0x2ac/0x2d8
[<800a77b8>] __lock_acquire+0x10d4/0x17bc
[<800a8384>] lock_acquire+0x60/0x88
[<802950a8>] mutex_lock_nested+0x54/0x31c
[<816468a4>] set_regdom+0x78c/0x808 [cfg80211]

Reported-by: Felix Fietkau <nbd@openwrt.org>
Tested-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Luis R. Rodriguez <mcgrof@do-not-panic.com>
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
alexelder pushed a commit that referenced this pull request May 21, 2013
commit 01bb650 upstream.

Fixes the following NULL pointer dereference:
[    7.740000] ohci_hcd: USB 1.1 'Open' Host Controller (OHCI) Driver
[    7.810000] Unable to handle kernel NULL pointer dereference at virtual address 00000028
[    7.810000] pgd = c3a38000
[    7.810000] [00000028] *pgd=23a8c831, *pte=00000000, *ppte=00000000
[    7.810000] Internal error: Oops: 17 [#1] PREEMPT ARM
[    7.810000] Modules linked in: ohci_hcd(+) regmap_i2c snd_pcm usbcore snd_page_alloc at91_cf snd_timer pcmcia_rsrc snd soundcore gpio_keys regmap_spi pcmcia_core usb_common nls_base
[    7.810000] CPU: 0    Not tainted  (3.6.0-rc6-mpa+ #264)
[    7.810000] PC is at __gpio_to_irq+0x18/0x40
[    7.810000] LR is at ohci_hcd_at91_overcurrent_irq+0x24/0xb4 [ohci_hcd]
[    7.810000] pc : [<c01392d4>]    lr : [<bf08f694>]    psr: 40000093
[    7.810000] sp : c3a11c40  ip : c3a11c50  fp : c3a11c4c
[    7.810000] r10: 00000000  r9 : c02dcd6e  r8 : fefff400
[    7.810000] r7 : 00000000  r6 : c02cc928  r5 : 00000030  r4 : c02dd168
[    7.810000] r3 : c02e7350  r2 : ffffffea  r1 : c02cc928  r0 : 00000000
[    7.810000] Flags: nZcv  IRQs off  FIQs on  Mode SVC_32  ISA ARM  Segment user
[    7.810000] Control: c000717f  Table: 23a38000  DAC: 00000015
[    7.810000] Process modprobe (pid: 285, stack limit = 0xc3a10270)
[    7.810000] Stack: (0xc3a11c40 to 0xc3a12000)
[    7.810000] 1c40: c3a11c6c c3a11c50 bf08f694 c01392cc c3a11c84 c2c38b00 c3806900 00000030
[    7.810000] 1c60: c3a11ca4 c3a11c70 c0051264 bf08f680 c3a11cac c3a11c80 c003e764 c3806900
[    7.810000] 1c80: c2c38b00 c02cb05c c02cb000 fefff400 c3806930 c3a11cf4 c3a11cbc c3a11ca8
[    7.810000] 1ca0: c005142c c005123c c3806900 c3805a00 c3a11cd4 c3a11cc0 c0053f24 c00513e4
[    7.810000] 1cc0: c3a11cf4 00000030 c3a11cec c3a11cd8 c005120c c0053e88 00000000 00000000
[    7.810000] 1ce0: c3a11d1c c3a11cf0 c00124d0 c00511e0 01400000 00000001 00000012 00000000
[    7.810000] 1d00: ffffffff c3a11d94 00000030 00000000 c3a11d34 c3a11d20 c005120c c0012438
[    7.810000] 1d20: c001dac4 00000012 c3a11d4c c3a11d38 c0009b08 c00511e0 c00523fc 60000013
[    7.810000] 1d40: c3a11d5c c3a11d50 c0008510 c0009ab4 c3a11ddc c3a11d60 c0008eb4 c00084f0
[    7.810000] 1d60: 00000000 00000030 00000000 00000080 60000013 bf08f670 c3806900 c2c38b00
[    7.810000] 1d80: 00000030 c3806930 00000000 c3a11ddc c3a11d88 c3a11da8 c0054190 c00523fc
[    7.810000] 1da0: 60000013 ffffffff c3a11dec c3a11db8 00000000 c2c38b00 bf08f670 c3806900
[    7.810000] 1dc0: 00000000 00000080 c02cc928 00000030 c3a11e0c c3a11de0 c0052764 c00520d8
[    7.810000] 1de0: c3a11dfc 00000000 00000000 00000002 bf090f61 00000004 c02cc930 c02cc928
[    7.810000] 1e00: c3a11e4c c3a11e10 bf090978 c005269c bf090f61 c02cc928 bf093000 c02dd170
[    7.810000] 1e20: c3a11e3c c02cc930 c02cc930 bf0911d0 bf0911d0 bf093000 c3a10000 00000000
[    7.810000] 1e40: c3a11e5c c3a11e50 c0155b7c bf090808 c3a11e7c c3a11e60 c0154690 c0155b6c
[    7.810000] 1e60: c02cc930 c02cc964 bf0911d0 c3a11ea0 c3a11e9c c3a11e80 c015484c c01545e8
[    7.810000] 1e80: 00000000 00000000 c01547e4 bf0911d0 c3a11ec4 c3a11ea0 c0152e58 c01547f4
[    7.810000] 1ea0: c381b88c c384ab10 c2c10540 bf0911d0 00000000 c02d7518 c3a11ed4 c3a11ec8
[    7.810000] 1ec0: c01544c0 c0152e0c c3a11efc c3a11ed8 c01536cc c01544b0 bf091075 c3a11ee8
[    7.810000] 1ee0: bf049af0 bf09120c bf0911d0 00000000 c3a11f1c c3a11f00 c0154e9c c0153628
[    7.810000] 1f00: bf049af0 bf09120c 000ae190 00000000 c3a11f2c c3a11f20 c0155f58 c0154e04
[    7.810000] 1f20: c3a11f44 c3a11f30 bf093054 c0155f1c 00000000 00006a4f c3a11f7c c3a11f48
[    7.810000] 1f40: c0008638 bf093010 bf09120c 000ae190 00000000 c00093c4 00006a4f bf09120c
[    7.810000] 1f60: 000ae190 00000000 c00093c4 00000000 c3a11fa4 c3a11f80 c004fdc4 c000859c
[    7.810000] 1f80: c3a11fa4 000ae190 00006a4f 00016eb8 000ad018 00000080 00000000 c3a11fa8
[    7.810000] 1fa0: c0009260 c004fd58 00006a4f 00016eb8 000ae190 00006a4f 000ae100 00000000
[    7.810000] 1fc0: 00006a4f 00016eb8 000ad018 00000080 000adba0 000ad208 00000000 000ad3d8
[    7.810000] 1fe0: beaf7ae8 beaf7ad8 000172b8 b6e4e940 20000010 000ae190 00000000 00000000
[    7.810000] Backtrace:
[    7.810000] [<c01392bc>] (__gpio_to_irq+0x0/0x40) from [<bf08f694>] (ohci_hcd_at91_overcurrent_irq+0x24/0xb4 [ohci_hcd])
[    7.810000] [<bf08f670>] (ohci_hcd_at91_overcurrent_irq+0x0/0xb4 [ohci_hcd]) from [<c0051264>] (handle_irq_event_percpu+0x38/0x1a8)
[    7.810000]  r6:00000030 r5:c3806900 r4:c2c38b00
[    7.810000] [<c005122c>] (handle_irq_event_percpu+0x0/0x1a8) from [<c005142c>] (handle_irq_event+0x58/0x7c)
[    7.810000] [<c00513d4>] (handle_irq_event+0x0/0x7c) from [<c0053f24>] (handle_simple_irq+0xac/0xd8)
[    7.810000]  r5:c3805a00 r4:c3806900
[    7.810000] [<c0053e78>] (handle_simple_irq+0x0/0xd8) from [<c005120c>] (generic_handle_irq+0x3c/0x48)
[    7.810000]  r4:00000030
[    7.810000] [<c00511d0>] (generic_handle_irq+0x0/0x48) from [<c00124d0>] (gpio_irq_handler+0xa8/0xfc)
[    7.810000]  r4:00000000
[    7.810000] [<c0012428>] (gpio_irq_handler+0x0/0xfc) from [<c005120c>] (generic_handle_irq+0x3c/0x48)
[    7.810000] [<c00511d0>] (generic_handle_irq+0x0/0x48) from [<c0009b08>] (handle_IRQ+0x64/0x88)
[    7.810000]  r4:00000012
[    7.810000] [<c0009aa4>] (handle_IRQ+0x0/0x88) from [<c0008510>] (at91_aic_handle_irq+0x30/0x38)
[    7.810000]  r5:60000013 r4:c00523fc
[    7.810000] [<c00084e0>] (at91_aic_handle_irq+0x0/0x38) from [<c0008eb4>] (__irq_svc+0x34/0x60)
[    7.810000] Exception stack(0xc3a11d60 to 0xc3a11da8)
[    7.810000] 1d60: 00000000 00000030 00000000 00000080 60000013 bf08f670 c3806900 c2c38b00
[    7.810000] 1d80: 00000030 c3806930 00000000 c3a11ddc c3a11d88 c3a11da8 c0054190 c00523fc
[    7.810000] 1da0: 60000013 ffffffff
[    7.810000] [<c00520c8>] (__setup_irq+0x0/0x458) from [<c0052764>] (request_threaded_irq+0xd8/0x134)
[    7.810000] [<c005268c>] (request_threaded_irq+0x0/0x134) from [<bf090978>] (ohci_hcd_at91_drv_probe+0x180/0x41c [ohci_hcd])
[    7.810000] [<bf0907f8>] (ohci_hcd_at91_drv_probe+0x0/0x41c [ohci_hcd]) from [<c0155b7c>] (platform_drv_probe+0x20/0x24)
[    7.810000] [<c0155b5c>] (platform_drv_probe+0x0/0x24) from [<c0154690>] (driver_probe_device+0xb8/0x20c)
[    7.810000] [<c01545d8>] (driver_probe_device+0x0/0x20c) from [<c015484c>] (__driver_attach+0x68/0x88)
[    7.810000]  r7:c3a11ea0 r6:bf0911d0 r5:c02cc964 r4:c02cc930
[    7.810000] [<c01547e4>] (__driver_attach+0x0/0x88) from [<c0152e58>] (bus_for_each_dev+0x5c/0x9c)
[    7.810000]  r6:bf0911d0 r5:c01547e4 r4:00000000
[    7.810000] [<c0152dfc>] (bus_for_each_dev+0x0/0x9c) from [<c01544c0>] (driver_attach+0x20/0x28)
[    7.810000]  r7:c02d7518 r6:00000000 r5:bf0911d0 r4:c2c10540
[    7.810000] [<c01544a0>] (driver_attach+0x0/0x28) from [<c01536cc>] (bus_add_driver+0xb4/0x22c)
[    7.810000] [<c0153618>] (bus_add_driver+0x0/0x22c) from [<c0154e9c>] (driver_register+0xa8/0x144)
[    7.810000]  r7:00000000 r6:bf0911d0 r5:bf09120c r4:bf049af0
[    7.810000] [<c0154df4>] (driver_register+0x0/0x144) from [<c0155f58>] (platform_driver_register+0x4c/0x60)
[    7.810000]  r7:00000000 r6:000ae190 r5:bf09120c r4:bf049af0
[    7.810000] [<c0155f0c>] (platform_driver_register+0x0/0x60) from [<bf093054>] (ohci_hcd_mod_init+0x54/0x8c [ohci_hcd])
[    7.810000] [<bf093000>] (ohci_hcd_mod_init+0x0/0x8c [ohci_hcd]) from [<c0008638>] (do_one_initcall+0xac/0x174)
[    7.810000]  r4:00006a4f
[    7.810000] [<c000858c>] (do_one_initcall+0x0/0x174) from [<c004fdc4>] (sys_init_module+0x7c/0x1a0)
[    7.810000] [<c004fd48>] (sys_init_module+0x0/0x1a0) from [<c0009260>] (ret_fast_syscall+0x0/0x2c)
[    7.810000]  r7:00000080 r6:000ad018 r5:00016eb8 r4:00006a4f
[    7.810000] Code: e24cb004 e59f3028 e1a02000 e7930180 (e5903028)
[    7.810000] ---[ end trace 85aa37ed128143b5 ]---
[    7.810000] Kernel panic - not syncing: Fatal exception in interrupt

Commit 6fffb77 (USB: ohci-at91: fix PIO handling in relation with number of
ports) started setting unused pins to EINVAL. But this exposed a bug in the
ohci_hcd_at91_overcurrent_irq function where the gpio was used without being
checked to see if it is valid.

This patches fixed the issue by adding the gpio valid check.

Signed-off-by: Joachim Eastwood <joachim.eastwood@jotron.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
alexelder pushed a commit that referenced this pull request May 21, 2013
commit 2d838bb upstream.

When b43legacy is loaded without the firmware being available, a following
unload generates a kernel NULL pointer dereference BUG as follows:

[  214.330789] BUG: unable to handle kernel NULL pointer dereference at 0000004c
[  214.330997] IP: [<c104c395>] drain_workqueue+0x15/0x170
[  214.331179] *pde = 00000000
[  214.331311] Oops: 0000 [#1] SMP
[  214.331471] Modules linked in: b43legacy(-) ssb pcmcia mac80211 cfg80211 af_packet mperf arc4 ppdev sr_mod cdrom sg shpchp yenta_socket pcmcia_rsrc pci_hotplug pcmcia_core battery parport_pc parport floppy container ac button edd autofs4 ohci_hcd ehci_hcd usbcore usb_common thermal processor scsi_dh_rdac scsi_dh_hp_sw scsi_dh_emc scsi_dh_alua scsi_dh fan thermal_sys hwmon ata_generic pata_ali libata [last unloaded: cfg80211]
[  214.333421] Pid: 3639, comm: modprobe Not tainted 3.6.0-rc6-wl+ #163 Source Technology VIC 9921/ALI Based Notebook
[  214.333580] EIP: 0060:[<c104c395>] EFLAGS: 00010246 CPU: 0
[  214.333687] EIP is at drain_workqueue+0x15/0x170
[  214.333788] EAX: c162ac40 EBX: cdfb8360 ECX: 0000002a EDX: 00002a2a
[  214.333890] ESI: 00000000 EDI: 00000000 EBP: cd767e7c ESP: cd767e5c
[  214.333957]  DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
[  214.333957] CR0: 8005003b CR2: 0000004c CR3: 0c96a000 CR4: 00000090
[  214.333957] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
[  214.333957] DR6: ffff0ff0 DR7: 00000400
[  214.333957] Process modprobe (pid: 3639, ti=cd766000 task=cf802e90 task.ti=cd766000)
[  214.333957] Stack:
[  214.333957]  00000292 cd767e74 c12c5e09 00000296 00000296 cdfb8360 cdfb9220 00000000
[  214.333957]  cd767e90 c104c4fd cdfb8360 cdfb9220 cd682800 cd767ea4 d0c10184 cd682800
[  214.333957]  cd767ea4 cba31064 cd767eb8 d0867908 cba31064 d087e09c cd96f034 cd767ec4
[  214.333957] Call Trace:
[  214.333957]  [<c12c5e09>] ? skb_dequeue+0x49/0x60
[  214.333957]  [<c104c4fd>] destroy_workqueue+0xd/0x150
[  214.333957]  [<d0c10184>] ieee80211_unregister_hw+0xc4/0x100 [mac80211]
[  214.333957]  [<d0867908>] b43legacy_remove+0x78/0x80 [b43legacy]
[  214.333957]  [<d083654d>] ssb_device_remove+0x1d/0x30 [ssb]
[  214.333957]  [<c126f15a>] __device_release_driver+0x5a/0xb0
[  214.333957]  [<c126fb07>] driver_detach+0x87/0x90
[  214.333957]  [<c126ef4c>] bus_remove_driver+0x6c/0xe0
[  214.333957]  [<c1270120>] driver_unregister+0x40/0x70
[  214.333957]  [<d083686b>] ssb_driver_unregister+0xb/0x10 [ssb]
[  214.333957]  [<d087c488>] b43legacy_exit+0xd/0xf [b43legacy]
[  214.333957]  [<c1089dde>] sys_delete_module+0x14e/0x2b0
[  214.333957]  [<c110a4a7>] ? vfs_write+0xf7/0x150
[  214.333957]  [<c1240050>] ? tty_write_lock+0x50/0x50
[  214.333957]  [<c110a6f8>] ? sys_write+0x38/0x70
[  214.333957]  [<c1397c55>] syscall_call+0x7/0xb
[  214.333957] Code: bc 27 00 00 00 00 a1 74 61 56 c1 55 89 e5 e8 a3 fc ff ff 5d c3 90 55 89 e5 57 56 89 c6 53 b8 40 ac 62 c1 83 ec 14 e8 bb b7 34 00 <8b> 46 4c 8d 50 01 85 c0 89 56 4c 75 03 83 0e 40 80 05 40 ac 62
[  214.333957] EIP: [<c104c395>] drain_workqueue+0x15/0x170 SS:ESP 0068:cd767e5c
[  214.333957] CR2: 000000000000004c
[  214.341110] ---[ end trace c7e90ec026d875a6 ]---Index: wireless-testing/drivers/net/wireless/b43legacy/main.c

The problem is fixed by making certain that the ucode pointer is not NULL
before deregistering the driver in mac80211.

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
alexelder pushed a commit that referenced this pull request May 21, 2013
commit 00d4e73 upstream.

In ext4_nonda_switch(), if the file system is getting full we used to
call writeback_inodes_sb_if_idle().  The problem is that we can be
holding i_mutex already, and this causes a potential deadlock when
writeback_inodes_sb_if_idle() when it tries to take s_umount.  (See
lockdep output below).

As it turns out we don't need need to hold s_umount; the fact that we
are in the middle of the write(2) system call will keep the superblock
pinned.  Unfortunately writeback_inodes_sb() checks to make sure
s_umount is taken, and the VFS uses a different mechanism for making
sure the file system doesn't get unmounted out from under us.  The
simplest way of dealing with this is to just simply grab s_umount
using a trylock, and skip kicking the writeback flusher thread in the
very unlikely case that we can't take a read lock on s_umount without
blocking.

Also, we now check the cirteria for kicking the writeback thread
before we decide to whether to fall back to non-delayed writeback, so
if there are any outstanding delayed allocation writes, we try to get
them resolved as soon as possible.

   [ INFO: possible circular locking dependency detected ]
   3.6.0-rc1-00042-gce894ca #367 Not tainted
   -------------------------------------------------------
   dd/8298 is trying to acquire lock:
    (&type->s_umount_key#18){++++..}, at: [<c02277d4>] writeback_inodes_sb_if_idle+0x28/0x46

   but task is already holding lock:
    (&sb->s_type->i_mutex_key#8){+.+...}, at: [<c01ddcce>] generic_file_aio_write+0x5f/0xd3

   which lock already depends on the new lock.

   2 locks held by dd/8298:
    #0:  (sb_writers#2){.+.+.+}, at: [<c01ddcc5>] generic_file_aio_write+0x56/0xd3
    #1:  (&sb->s_type->i_mutex_key#8){+.+...}, at: [<c01ddcce>] generic_file_aio_write+0x5f/0xd3

   stack backtrace:
   Pid: 8298, comm: dd Not tainted 3.6.0-rc1-00042-gce894ca #367
   Call Trace:
    [<c015b79c>] ? console_unlock+0x345/0x372
    [<c06d62a1>] print_circular_bug+0x190/0x19d
    [<c019906c>] __lock_acquire+0x86d/0xb6c
    [<c01999db>] ? mark_held_locks+0x5c/0x7b
    [<c0199724>] lock_acquire+0x66/0xb9
    [<c02277d4>] ? writeback_inodes_sb_if_idle+0x28/0x46
    [<c06db935>] down_read+0x28/0x58
    [<c02277d4>] ? writeback_inodes_sb_if_idle+0x28/0x46
    [<c02277d4>] writeback_inodes_sb_if_idle+0x28/0x46
    [<c026f3b2>] ext4_nonda_switch+0xe1/0xf4
    [<c0271ece>] ext4_da_write_begin+0x27/0x193
    [<c01dcdb0>] generic_file_buffered_write+0xc8/0x1bb
    [<c01ddc47>] __generic_file_aio_write+0x1dd/0x205
    [<c01ddce7>] generic_file_aio_write+0x78/0xd3
    [<c026d336>] ext4_file_write+0x480/0x4a6
    [<c0198c1d>] ? __lock_acquire+0x41e/0xb6c
    [<c0180944>] ? sched_clock_cpu+0x11a/0x13e
    [<c01967e9>] ? trace_hardirqs_off+0xb/0xd
    [<c018099f>] ? local_clock+0x37/0x4e
    [<c0209f2c>] do_sync_write+0x67/0x9d
    [<c0209ec5>] ? wait_on_retry_sync_kiocb+0x44/0x44
    [<c020a7b9>] vfs_write+0x7b/0xe6
    [<c020a9a6>] sys_write+0x3b/0x64
    [<c06dd4bd>] syscall_call+0x7/0xb

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
alexelder pushed a commit that referenced this pull request May 21, 2013
commit 7d9b110 upstream.

Do not kfree() the mtd_info; it is handled in the mtd subsystem and
already freed by nand_release(). Instead kfree() the struct
omap_nand_info allocated in omap_nand_probe which was not freed before.

This patch fixes following error when unloading the omap2 module:

---8<---
~ $ rmmod omap2
------------[ cut here ]------------
kernel BUG at mm/slab.c:3126!
Internal error: Oops - BUG: 0 [#1] PREEMPT ARM
Modules linked in: omap2(-)
CPU: 0    Not tainted  (3.6.0-rc3-00230-g155e36d-dirty #3)
PC is at cache_free_debugcheck+0x2d4/0x36c
LR is at kfree+0xc8/0x2ac
pc : [<c01125a0>]    lr : [<c0112efc>]    psr: 200d0193
sp : c521fe08  ip : c0e8ef90  fp : c521fe5c
r10: bf0001fc  r9 : c521e000  r8 : c0d99c8c
r7 : c661ebc0  r6 : c065d5a4  r5 : c65c4060  r4 : c78005c0
r3 : 00000000  r2 : 00001000  r1 : c65c4000  r0 : 00000001
Flags: nzCv  IRQs off  FIQs on  Mode SVC_32  ISA ARM  Segment user
Control: 10c5387d  Table: 86694019  DAC: 00000015
Process rmmod (pid: 549, stack limit = 0xc521e2f0)
Stack: (0xc521fe08 to 0xc5220000)
fe00:                   c008a874 c00bf44c c515c6d0 200d0193 c65c4860 c515c240
fe20: c521fe3c c521fe30 c008a9c0 c008a854 c521fe5c c65c4860 c78005c0 bf0001fc
fe40: c780ff40 a00d0113 c521e000 00000000 c521fe84 c521fe60 c0112efc c01122d8
fe60: c65c4860 c0673778 c06737ac 00000000 00070013 00000000 c521fe9c c521fe88
fe80: bf0001fc c0112e40 c0673778 bf001ca8 c521feac c521fea0 c02ca11c bf0001ac
fea0: c521fec4 c521feb0 c02c82c4 c02ca100 c0673778 bf001ca8 c521fee4 c521fec8
fec0: c02c8dd8 c02c8250 00000000 bf001ca8 bf001ca8 c0804ee0 c521ff04 c521fee8
fee0: c02c804c c02c8d20 bf001924 00000000 bf001ca8 c521e000 c521ff1c c521ff08
ff00: c02c950c c02c7fbc bf001d48 00000000 c521ff2c c521ff20 c02ca3a4 c02c94b8
ff20: c521ff3c c521ff30 bf001938 c02ca394 c521ffa4 c521ff40 c009beb4 bf001930
ff40: c521ff6c 70616d6f b6fe0032 c0014f84 70616d6f b6fe0032 00000081 60070010
ff60: c521ff84 c521ff70 c008e1f4 c00bf328 0001a004 70616d6f c521ff94 0021ff88
ff80: c008e368 0001a004 70616d6f b6fe0032 00000081 c0015028 00000000 c521ffa8
ffa0: c0014dc0 c009bcd0 0001a004 70616d6f bec2ab38 00000880 bec2ab38 00000880
ffc0: 0001a004 70616d6f b6fe0032 00000081 00000319 00000000 b6fe1000 00000000
ffe0: bec2ab30 bec2ab20 00019f00 b6f539c0 60070010 bec2ab38 aaaaaaaa aaaaaaaa
Backtrace:
[<c01122cc>] (cache_free_debugcheck+0x0/0x36c) from [<c0112efc>] (kfree+0xc8/0x2ac)
[<c0112e34>] (kfree+0x0/0x2ac) from [<bf0001fc>] (omap_nand_remove+0x5c/0x64 [omap2])
[<bf0001a0>] (omap_nand_remove+0x0/0x64 [omap2]) from [<c02ca11c>] (platform_drv_remove+0x28/0x2c)
 r5:bf001ca8 r4:c0673778
[<c02ca0f4>] (platform_drv_remove+0x0/0x2c) from [<c02c82c4>] (__device_release_driver+0x80/0xdc)
[<c02c8244>] (__device_release_driver+0x0/0xdc) from [<c02c8dd8>] (driver_detach+0xc4/0xc8)
 r5:bf001ca8 r4:c0673778
[<c02c8d14>] (driver_detach+0x0/0xc8) from [<c02c804c>] (bus_remove_driver+0x9c/0x104)
 r6:c0804ee0 r5:bf001ca8 r4:bf001ca8 r3:00000000
[<c02c7fb0>] (bus_remove_driver+0x0/0x104) from [<c02c950c>] (driver_unregister+0x60/0x80)
 r6:c521e000 r5:bf001ca8 r4:00000000 r3:bf001924
[<c02c94ac>] (driver_unregister+0x0/0x80) from [<c02ca3a4>] (platform_driver_unregister+0x1c/0x20)
 r5:00000000 r4:bf001d48
[<c02ca388>] (platform_driver_unregister+0x0/0x20) from [<bf001938>] (omap_nand_driver_exit+0x14/0x1c [omap2])
[<bf001924>] (omap_nand_driver_exit+0x0/0x1c [omap2]) from [<c009beb4>] (sys_delete_module+0x1f0/0x2ec)
[<c009bcc4>] (sys_delete_module+0x0/0x2ec) from [<c0014dc0>] (ret_fast_syscall+0x0/0x48)
 r8:c0015028 r7:00000081 r6:b6fe0032 r5:70616d6f r4:0001a004
Code: e1a00005 eb0d9172 e7f001f2 e7f001f2 (e7f001f2)
---[ end trace 6a30b24d8c0cc2ee ]---
Segmentation fault
--->8---

This error was introduced in 67ce04b which
was the first commit of this driver.

Signed-off-by: Andreas Bießmann <andreas@biessmann.de>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
alexelder pushed a commit that referenced this pull request May 21, 2013
commit 35c2a7f upstream.

Fuzzing with trinity oopsed on the 1st instruction of shmem_fh_to_dentry(),
	u64 inum = fid->raw[2];
which is unhelpfully reported as at the end of shmem_alloc_inode():

BUG: unable to handle kernel paging request at ffff880061cd3000
IP: [<ffffffff812190d0>] shmem_alloc_inode+0x40/0x40
Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
Call Trace:
 [<ffffffff81488649>] ? exportfs_decode_fh+0x79/0x2d0
 [<ffffffff812d77c3>] do_handle_open+0x163/0x2c0
 [<ffffffff812d792c>] sys_open_by_handle_at+0xc/0x10
 [<ffffffff83a5f3f8>] tracesys+0xe1/0xe6

Right, tmpfs is being stupid to access fid->raw[2] before validating that
fh_len includes it: the buffer kmalloc'ed by do_sys_name_to_handle() may
fall at the end of a page, and the next page not be present.

But some other filesystems (ceph, gfs2, isofs, reiserfs, xfs) are being
careless about fh_len too, in fh_to_dentry() and/or fh_to_parent(), and
could oops in the same way: add the missing fh_len checks to those.

Reported-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Sage Weil <sage@inktank.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
alexelder pushed a commit that referenced this pull request May 21, 2013
commit 1a7bbda upstream.

We actually do not do anything about it. Just return a default
value of zero and if the kernel tries to write anything but 0
we BUG_ON.

This fixes the case when an user tries to suspend the machine
and it blows up in save_processor_state b/c 'read_cr8' is set
to NULL and we get:

kernel BUG at /home/konrad/ssd/linux/arch/x86/include/asm/paravirt.h:100!
invalid opcode: 0000 [#1] SMP
Pid: 2687, comm: init.late Tainted: G           O 3.6.0upstream-00002-gac264ac-dirty #4 Bochs Bochs
RIP: e030:[<ffffffff814d5f42>]  [<ffffffff814d5f42>] save_processor_state+0x212/0x270

.. snip..
Call Trace:
 [<ffffffff810733bf>] do_suspend_lowlevel+0xf/0xac
 [<ffffffff8107330c>] ? x86_acpi_suspend_lowlevel+0x10c/0x150
 [<ffffffff81342ee2>] acpi_suspend_enter+0x57/0xd5

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
alexelder pushed a commit that referenced this pull request May 21, 2013
commit 9e33ce4 upstream.

IPVS should not reset skb->nf_bridge in FORWARD hook
by calling nf_reset for NAT replies. It triggers oops in
br_nf_forward_finish.

[  579.781508] BUG: unable to handle kernel NULL pointer dereference at 0000000000000004
[  579.781669] IP: [<ffffffff817b1ca5>] br_nf_forward_finish+0x58/0x112
[  579.781792] PGD 218f9067 PUD 0
[  579.781865] Oops: 0000 [#1] SMP
[  579.781945] CPU 0
[  579.781983] Modules linked in:
[  579.782047]
[  579.782080]
[  579.782114] Pid: 4644, comm: qemu Tainted: G        W    3.5.0-rc5-00006-g95e69f9 #282 Hewlett-Packard  /30E8
[  579.782300] RIP: 0010:[<ffffffff817b1ca5>]  [<ffffffff817b1ca5>] br_nf_forward_finish+0x58/0x112
[  579.782455] RSP: 0018:ffff88007b003a98  EFLAGS: 00010287
[  579.782541] RAX: 0000000000000008 RBX: ffff8800762ead00 RCX: 000000000001670a
[  579.782653] RDX: 0000000000000000 RSI: 000000000000000a RDI: ffff8800762ead00
[  579.782845] RBP: ffff88007b003ac8 R08: 0000000000016630 R09: ffff88007b003a90
[  579.782957] R10: ffff88007b0038e8 R11: ffff88002da37540 R12: ffff88002da01a02
[  579.783066] R13: ffff88002da01a80 R14: ffff88002d83c000 R15: ffff88002d82a000
[  579.783177] FS:  0000000000000000(0000) GS:ffff88007b000000(0063) knlGS:00000000f62d1b70
[  579.783306] CS:  0010 DS: 002b ES: 002b CR0: 000000008005003b
[  579.783395] CR2: 0000000000000004 CR3: 00000000218fe000 CR4: 00000000000027f0
[  579.783505] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  579.783684] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[  579.783795] Process qemu (pid: 4644, threadinfo ffff880021b20000, task ffff880021aba760)
[  579.783919] Stack:
[  579.783959]  ffff88007693cedc ffff8800762ead00 ffff88002da01a02 ffff8800762ead00
[  579.784110]  ffff88002da01a02 ffff88002da01a80 ffff88007b003b18 ffffffff817b26c7
[  579.784260]  ffff880080000000 ffffffff81ef59f0 ffff8800762ead00 ffffffff81ef58b0
[  579.784477] Call Trace:
[  579.784523]  <IRQ>
[  579.784562]
[  579.784603]  [<ffffffff817b26c7>] br_nf_forward_ip+0x275/0x2c8
[  579.784707]  [<ffffffff81704b58>] nf_iterate+0x47/0x7d
[  579.784797]  [<ffffffff817ac32e>] ? br_dev_queue_push_xmit+0xae/0xae
[  579.784906]  [<ffffffff81704bfb>] nf_hook_slow+0x6d/0x102
[  579.784995]  [<ffffffff817ac32e>] ? br_dev_queue_push_xmit+0xae/0xae
[  579.785175]  [<ffffffff8187fa95>] ? _raw_write_unlock_bh+0x19/0x1b
[  579.785179]  [<ffffffff817ac417>] __br_forward+0x97/0xa2
[  579.785179]  [<ffffffff817ad366>] br_handle_frame_finish+0x1a6/0x257
[  579.785179]  [<ffffffff817b2386>] br_nf_pre_routing_finish+0x26d/0x2cb
[  579.785179]  [<ffffffff817b2cf0>] br_nf_pre_routing+0x55d/0x5c1
[  579.785179]  [<ffffffff81704b58>] nf_iterate+0x47/0x7d
[  579.785179]  [<ffffffff817ad1c0>] ? br_handle_local_finish+0x44/0x44
[  579.785179]  [<ffffffff81704bfb>] nf_hook_slow+0x6d/0x102
[  579.785179]  [<ffffffff817ad1c0>] ? br_handle_local_finish+0x44/0x44
[  579.785179]  [<ffffffff81551525>] ? sky2_poll+0xb35/0xb54
[  579.785179]  [<ffffffff817ad62a>] br_handle_frame+0x213/0x229
[  579.785179]  [<ffffffff817ad417>] ? br_handle_frame_finish+0x257/0x257
[  579.785179]  [<ffffffff816e3b47>] __netif_receive_skb+0x2b4/0x3f1
[  579.785179]  [<ffffffff816e69fc>] process_backlog+0x99/0x1e2
[  579.785179]  [<ffffffff816e6800>] net_rx_action+0xdf/0x242
[  579.785179]  [<ffffffff8107e8a8>] __do_softirq+0xc1/0x1e0
[  579.785179]  [<ffffffff8135a5ba>] ? trace_hardirqs_off_thunk+0x3a/0x6c
[  579.785179]  [<ffffffff8188812c>] call_softirq+0x1c/0x30

The steps to reproduce as follow,

1. On Host1, setup brige br0(192.168.1.106)
2. Boot a kvm guest(192.168.1.105) on Host1 and start httpd
3. Start IPVS service on Host1
   ipvsadm -A -t 192.168.1.106:80 -s rr
   ipvsadm -a -t 192.168.1.106:80 -r 192.168.1.105:80 -m
4. Run apache benchmark on Host2(192.168.1.101)
   ab -n 1000 http://192.168.1.106/

ip_vs_reply4
  ip_vs_out
    handle_response
      ip_vs_notrack
        nf_reset()
        {
          skb->nf_bridge = NULL;
        }

Actually, IPVS wants in this case just to replace nfct
with untracked version. So replace the nf_reset(skb) call
in ip_vs_notrack() with a nf_conntrack_put(skb->nfct) call.

Signed-off-by: Lin Ming <mlin@ss.pku.edu.cn>
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Acked-by: David Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
alexelder pushed a commit that referenced this pull request May 21, 2013
…tation

commit 3f509c6 upstream.

We're hitting bug while trying to reinsert an already existing
expectation:

kernel BUG at kernel/timer.c:895!
invalid opcode: 0000 [#1] SMP
[...]
Call Trace:
 <IRQ>
 [<ffffffffa0069563>] nf_ct_expect_related_report+0x4a0/0x57a [nf_conntrack]
 [<ffffffff812d423a>] ? in4_pton+0x72/0x131
 [<ffffffffa00ca69e>] ip_nat_sdp_media+0xeb/0x185 [nf_nat_sip]
 [<ffffffffa00b5b9b>] set_expected_rtp_rtcp+0x32d/0x39b [nf_conntrack_sip]
 [<ffffffffa00b5f15>] process_sdp+0x30c/0x3ec [nf_conntrack_sip]
 [<ffffffff8103f1eb>] ? irq_exit+0x9a/0x9c
 [<ffffffffa00ca738>] ? ip_nat_sdp_media+0x185/0x185 [nf_nat_sip]

We have to remove the RTP expectation if the RTCP expectation hits EBUSY
since we keep trying with other ports until we succeed.

Reported-by: Rafal Fitt <rafalf@aplusc.com.pl>
Acked-by: David Miller <davem@davemloft.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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