commit 2acb5c30 upstream.

Driver core sets "default" pinmux on on probe and CAN driver
sets "sleep" pinmux during register. This causes a small window
where the CAN pins are in "default" state with the DCAN module
being disabled.

Change the "default" state to be like sleep so this glitch is
avoided. Add a new "active" state that is used by the driver
when CAN is actually active.
Signed-off-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

commit 03336519 upstream.

The previous change 3973c526 (net: can: c_can: Disable pins when CAN
interface is down) causes a slight glitch on the pinctrl settings when used.
Since commit ab78029e (drivers/pinctrl: grab default handles from device core),
the device core will automatically set the default pins. This causes the pins
to be momentarily set to the default and then to the sleep state in
register_c_can_dev(). By adding an optional "enable" state, boards can set the
default pin state to be disabled and avoid the glitch when the switch from
default to sleep first occurs. If the "enable" state is not available
c_can_pinctrl_select_state() falls back to using the "default" pinctrl state.

[Roger Q] - Forward port to v4.2 and use pinctrl_get_select().
Signed-off-by: J.D. Schroeder <jay.schroeder@garmin.com>
Signed-off-by: Roger Quadros <rogerq@ti.com>
Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

commit 5e63e6ba upstream.

rcar_can_probe() regards 0 as a wrong IRQ #, despite platform_get_irq() that it
calls returns negative error code in that case. This leads to the following
being printed to the console when attempting to open the device:

error requesting interrupt fffffffa

because  rcar_can_open() calls request_irq() with a negative IRQ #, and that
function naturally fails with -EINVAL.

Check for the negative error codes instead and propagate them upstream instead
of just returning -ENODEV.

Fixes: fd115931 ("can: add Renesas R-Car CAN driver")
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

commit d3efe084 upstream.

When we call btrfs_commit_transaction(), we splice the list "ordered"
of our transaction handle into the transaction's "pending_ordered"
list, but we don't re-initialize the "ordered" list of our transaction
handle, this means it still points to the same elements it used to
before the splice. Then we check if the current transaction's state is
>= TRANS_STATE_COMMIT_START and if it is we end up calling
btrfs_end_transaction() which simply splices again the "ordered" list
of our handle into the transaction's "pending_ordered" list, leaving
multiple pointers to the same ordered extents which results in list
corruption when we are iterating, removing and freeing ordered extents
at btrfs_wait_pending_ordered(), resulting in access to dangling
pointers / use-after-free issues.
Similarly, btrfs_end_transaction() can end up in some cases calling
btrfs_commit_transaction(), and both did a list splice of the transaction
handle's "ordered" list into the transaction's "pending_ordered" without
re-initializing the handle's "ordered" list, resulting in exactly the
same problem.

This produces the following warning on a kernel with linked list
debugging enabled:

[109749.265416] ------------[ cut here ]------------
[109749.266410] WARNING: CPU: 7 PID: 324 at lib/list_debug.c:59 __list_del_entry+0x5a/0x98()
[109749.267969] list_del corruption. prev->next should be ffff8800ba087e20, but was fffffff8c1f7c35d
(...)
[109749.287505] Call Trace:
[109749.288135]  [<ffffffff8145f077>] dump_stack+0x4f/0x7b
[109749.298080]  [<ffffffff81095de5>] ? console_unlock+0x356/0x3a2
[109749.331605]  [<ffffffff8104b3b0>] warn_slowpath_common+0xa1/0xbb
[109749.334849]  [<ffffffff81260642>] ? __list_del_entry+0x5a/0x98
[109749.337093]  [<ffffffff8104b410>] warn_slowpath_fmt+0x46/0x48
[109749.337847]  [<ffffffff81260642>] __list_del_entry+0x5a/0x98
[109749.338678]  [<ffffffffa053e8bf>] btrfs_wait_pending_ordered+0x46/0xdb [btrfs]
[109749.340145]  [<ffffffffa058a65f>] ? __btrfs_run_delayed_items+0x149/0x163 [btrfs]
[109749.348313]  [<ffffffffa054077d>] btrfs_commit_transaction+0x36b/0xa10 [btrfs]
[109749.349745]  [<ffffffff81087310>] ? trace_hardirqs_on+0xd/0xf
[109749.350819]  [<ffffffffa055370d>] btrfs_sync_file+0x36f/0x3fc [btrfs]
[109749.351976]  [<ffffffff8118ec98>] vfs_fsync_range+0x8f/0x9e
[109749.360341]  [<ffffffff8118ecc3>] vfs_fsync+0x1c/0x1e
[109749.368828]  [<ffffffff8118ee1d>] do_fsync+0x34/0x4e
[109749.369790]  [<ffffffff8118f045>] SyS_fsync+0x10/0x14
[109749.370925]  [<ffffffff81465197>] system_call_fastpath+0x12/0x6f
[109749.382274] ---[ end trace 48e0d07f7c03d95a ]---

On a non-debug kernel this leads to invalid memory accesses, causing a
crash. Fix this by using list_splice_init() instead of list_splice() in
btrfs_commit_transaction() and btrfs_end_transaction().

Fixes: 50d9aa99 ("Btrfs: make sure logged extents complete in the current transaction V3"
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

commit 497b4050 upstream.

We were allocating memory with memdup_user() but we were never releasing
that memory. This affected pretty much every call to the ioctl, whether
it deduplicated extents or not.

This issue was reported on IRC by Julian Taylor and on the mailing list
by Marcel Ritter, credit goes to them for finding the issue.
Reported-by: Julian Taylor <jtaylor.debian@googlemail.com>
Reported-by: Marcel Ritter <ritter.marcel@gmail.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

commit 370777da upstream.

fpu_activate is called outside of vcpu_load(), which means it should not
touch VMCS, but fpu_activate needs to.  Avoid the call by moving it to a
point where we know that the guest needs eager FPU and VMCS is loaded.

This will get rid of the following trace

 vmwrite error: reg 6800 value 0 (err 1)
  [<ffffffff8162035b>] dump_stack+0x19/0x1b
  [<ffffffffa046c701>] vmwrite_error+0x2c/0x2e [kvm_intel]
  [<ffffffffa045f26f>] vmcs_writel+0x1f/0x30 [kvm_intel]
  [<ffffffffa04617e5>] vmx_fpu_activate.part.61+0x45/0xb0 [kvm_intel]
  [<ffffffffa0461865>] vmx_fpu_activate+0x15/0x20 [kvm_intel]
  [<ffffffffa0560b91>] kvm_arch_vcpu_create+0x51/0x70 [kvm]
  [<ffffffffa0548011>] kvm_vm_ioctl+0x1c1/0x760 [kvm]
  [<ffffffff8118b55a>] ? handle_mm_fault+0x49a/0xec0
  [<ffffffff811e47d5>] do_vfs_ioctl+0x2e5/0x4c0
  [<ffffffff8127abbe>] ? file_has_perm+0xae/0xc0
  [<ffffffff811e4a51>] SyS_ioctl+0xa1/0xc0
  [<ffffffff81630949>] system_call_fastpath+0x16/0x1b

(Note: we also unconditionally activate FPU in vmx_vcpu_reset(), so the
 removed code added nothing.)

Fixes: c447e76b ("kvm/fpu: Enable eager restore kvm FPU for MPX")
Reported-by: Vlastimil Holer <vlastimil.holer@gmail.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

commit d23f47d4 upstream.

Destroy serial_minors IDR on module exit, reclaiming the allocated memory.

This was detected by the following semantic patch (written by Luis
Rodriguez <mcgrof@suse.com>)

<SmPL>
@ defines_module_init @
declarer name module_init, module_exit;
declarer name DEFINE_IDR;
identifier init;
@@

module_init(init);

@ defines_module_exit @
identifier exit;
@@

module_exit(exit);

@ declares_idr depends on defines_module_init && defines_module_exit @
identifier idr;
@@

DEFINE_IDR(idr);

@ on_exit_calls_destroy depends on declares_idr && defines_module_exit @
identifier declares_idr.idr, defines_module_exit.exit;
@@

exit(void)
{
 ...
 idr_destroy(&idr);
 ...
}

@ missing_module_idr_destroy depends on declares_idr && defines_module_exit && !on_exit_calls_destroy @
identifier declares_idr.idr, defines_module_exit.exit;
@@

exit(void)
{
 ...
 +idr_destroy(&idr);
}
</SmPL>
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

commit 1973db0d upstream.

When cpsw's number of slave is set to 1 in device tree and while
accessing second slave ndev and priv in cpsw_tx_interrupt(),
there is a kernel crash. This is due to cpsw_get_slave_priv()
not verifying number of slaves while retriving netdev priv and
returns a invalid memory region. Fixing the issue by introducing
number of slave check in cpsw_get_slave_priv() and
cpsw_get_slave_ndev().

[   15.879589] Unable to handle kernel paging request at virtual address 0f0e142c
[   15.888540] pgd = ed374000
[   15.891359] [0f0e142c] *pgd=00000000
[   15.895105] Internal error: Oops: 5 [#1] SMP ARM
[   15.899936] Modules linked in:
[   15.903139] CPU: 0 PID: 593 Comm: udhcpc Tainted: G        W       4.1.0-12205-gfda8b18c-dirty #10
[   15.912386] Hardware name: Generic AM43 (Flattened Device Tree)
[   15.918557] task: ed2a2e00 ti: ed3fe000 task.ti: ed3fe000
[   15.924187] PC is at cpsw_tx_interrupt+0x30/0x44
[   15.929008] LR is at _raw_spin_unlock_irqrestore+0x40/0x44
[   15.934726] pc : [<c048b9cc>]    lr : [<c05ef4f4>]    psr: 20000193
[   15.934726] sp : ed3ffc08  ip : ed2a2e40  fp : 00000000
[   15.946685] r10: c0969ce8  r9 : c0969cfc  r8 : 00000000
[   15.952129] r7 : 000000c6  r6 : ee54ab00  r5 : ee169c64  r4 : ee534e00
[   15.958932] r3 : 0f0e0d0c  r2 : 00000000  r1 : ed3ffbc0  r0 : 00000001
[   15.965735] Flags: nzCv  IRQs off  FIQs on  Mode SVC_32  ISA ARM  Segment user
[   15.973261] Control: 10c5387d  Table: ad374059  DAC: 00000015
[   15.979246] Process udhcpc (pid: 593, stack limit = 0xed3fe218)
[   15.985414] Stack: (0xed3ffc08 to 0xed400000)
[   15.989954] fc00:                   ee54ab00 c009928c c0a9e648 60000193 000032e4 ee169c00
[   15.998478] fc20: ee169c64 ee169c00 ee169c64 ee54ab00 00000001 00000001 ee67e268 ee008800
[   16.006995] fc40: ee534800 c009946c ee169c00 ee169c64 c08bd660 c009c370 c009c2a4 000000c6
[   16.015513] fc60: c08b75c4 c08b0854 00000000 c0098b3c 000000c6 c0098c50 ed3ffcb0 0000003a
[   16.024033] fc80: ed3ffcb0 fa24010c c08b7800 fa240100 ee7e9880 c00094c4 c05ef4e8 60000013
[   16.032556] fca0: ffffffff ed3ffce4 ee7e9880 c05ef964 00000001 ed2a33d8 00000000 ed2a2e00
[   16.041080] fcc0: 60000013 ee536bf8 60000013 ee51b800 ee7e9880 ee67e268 ee7e9880 ee534800
[   16.049603] fce0: c0ad0768 ed3ffcf8 c008e910 c05ef4e8 60000013 ffffffff 00000001 00000001
[   16.058121] fd00: ee536bf8 c0487a04 00000000 00000000 ee534800 00000000 00000156 c048c990
[   16.066645] fd20: 00000000 00000000 c0969f40 00000000 00000000 c05000e8 00000001 00000000
[   16.075167] fd40: 00000000 c051eefc 00000000 ee67e268 00000000 00000000 ee51b800 ed3ffd9c
[   16.083690] fd60: 00000000 ee67e200 ee51b800 ee7e9880 ee67e268 00000000 00000000 ee67e200
[   16.092211] fd80: ee51b800 ee7e9880 ee67e268 ee534800 ee67e200 c051eedc ee67e268 00000010
[   16.100727] fda0: 00000000 00000000 ee7e9880 ee534800 00000000 ee67e268 ee51b800 c05006fc
[   16.109247] fdc0: ee67e268 00000001 c0500488 00000156 ee7e9880 00000000 ed3fe000 fffffff4
[   16.117771] fde0: ed3fff1c ee7e9880 ee534800 00000148 00000000 ed1f8340 00000000 00000000
[   16.126289] fe00: 00000000 c05a9054 00000000 00000000 00000156 c0ab62a8 00000010 ed3e7000
[   16.134812] fe20: 00000000 00000008 edcfb700 ed3fff1c c0fb5f94 ed2a2e00 c0fb5f64 000005d8
[   16.143336] fe40: c0a9b3b8 00000000 ed3e7070 00000000 00000000 00000000 00009f40 00000000
[   16.151858] fe60: 00000000 00020022 00110008 00000000 00000000 43004400 00000000 ffffffff
[   16.160374] fe80: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[   16.168898] fea0: edcfb700 bee5f380 00000014 00000000 ed3fe000 00000000 00004400 c04e2b64
[   16.177415] fec0: 00000002 c04e3b00 ed3ffeec 00000001 0000011a 00000000 00000000 bee5f394
[   16.185937] fee0: 00000148 ed3fff10 00000014 00000001 00000000 00000000 ed3ffee4 00000000
[   16.194459] ff00: 00000000 00000000 00000000 c04e3664 00080011 00000002 06000000 ffffffff
[   16.202980] ff20: 0000ffff ffffffff 0000ffff c008dd54 ee5a6f08 ee636e80 c096972d c0089c14
[   16.211499] ff40: 00000000 60000013 ee5a6f40 60000013 00000000 ee5a6f40 00000002 00000006
[   16.220023] ff60: 00000000 edcfb700 00000001 ed2a2e00 c000f60c 00000001 0000011a c008ea34
[   16.228540] ff80: 00000006 00000000 bee5f380 00000014 bee5f380 00000014 bee5f380 00000122
[   16.237059] ffa0: c000f7c4 c000f5e0 bee5f380 00000014 00000006 bee5f394 00000148 00000000
[   16.245581] ffc0: bee5f380 00000014 bee5f380 00000122 fffffd6e 00004300 00004800 00004400
[   16.254104] ffe0: bee5f378 bee5f36c 000307ec b6f39044 40000010 00000006 ed36fa40 00000000
[   16.262642] [<c048b9cc>] (cpsw_tx_interrupt) from [<c009928c>] (handle_irq_event_percpu+0x64/0x204)
[   16.272076] [<c009928c>] (handle_irq_event_percpu) from [<c009946c>] (handle_irq_event+0x40/0x64)
[   16.281330] [<c009946c>] (handle_irq_event) from [<c009c370>] (handle_fasteoi_irq+0xcc/0x1a8)
[   16.290220] [<c009c370>] (handle_fasteoi_irq) from [<c0098b3c>] (generic_handle_irq+0x20/0x30)
[   16.299197] [<c0098b3c>] (generic_handle_irq) from [<c0098c50>] (__handle_domain_irq+0x64/0xdc)
[   16.308273] [<c0098c50>] (__handle_domain_irq) from [<c00094c4>] (gic_handle_irq+0x20/0x60)
[   16.316987] [<c00094c4>] (gic_handle_irq) from [<c05ef964>] (__irq_svc+0x44/0x5c)
[   16.324779] Exception stack(0xed3ffcb0 to 0xed3ffcf8)
[   16.330044] fca0:                                     00000001 ed2a33d8 00000000 ed2a2e00
[   16.338567] fcc0: 60000013 ee536bf8 60000013 ee51b800 ee7e9880 ee67e268 ee7e9880 ee534800
[   16.347090] fce0: c0ad0768 ed3ffcf8 c008e910 c05ef4e8 60000013 ffffffff
[   16.353987] [<c05ef964>] (__irq_svc) from [<c05ef4e8>] (_raw_spin_unlock_irqrestore+0x34/0x44)
[   16.362973] [<c05ef4e8>] (_raw_spin_unlock_irqrestore) from [<c0487a04>] (cpdma_check_free_tx_desc+0x60/0x6c)
[   16.373311] [<c0487a04>] (cpdma_check_free_tx_desc) from [<c048c990>] (cpsw_ndo_start_xmit+0xb4/0x1ac)
[   16.383017] [<c048c990>] (cpsw_ndo_start_xmit) from [<c05000e8>] (dev_hard_start_xmit+0x2a4/0x4c0)
[   16.392364] [<c05000e8>] (dev_hard_start_xmit) from [<c051eedc>] (sch_direct_xmit+0xf4/0x210)
[   16.401246] [<c051eedc>] (sch_direct_xmit) from [<c05006fc>] (__dev_queue_xmit+0x2ac/0x7bc)
[   16.409960] [<c05006fc>] (__dev_queue_xmit) from [<c05a9054>] (packet_sendmsg+0xc68/0xeb4)
[   16.418585] [<c05a9054>] (packet_sendmsg) from [<c04e2b64>] (sock_sendmsg+0x14/0x24)
[   16.426663] [<c04e2b64>] (sock_sendmsg) from [<c04e3b00>] (SyS_sendto+0xb4/0xe0)
[   16.434377] [<c04e3b00>] (SyS_sendto) from [<c000f5e0>] (ret_fast_syscall+0x0/0x54)
[   16.442360] Code: e5943118 e593303c e3530000 0a000002 (e5930720)
[   16.448716] ---[ end trace a68159f094d85ba6 ]---
[   16.453526] Kernel panic - not syncing: Fatal exception in interrupt
[   16.460149] ---[ end Kernel panic - not syncing: Fatal exception in interrupt
Signed-off-by: Mugunthan V N <mugunthanvnm@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

commit 6224beb1 upstream.

Fengguang Wu's tests triggered a bug in the branch tracer's start up
test when CONFIG_DEBUG_PREEMPT set. This was because that config
adds some debug logic in the per cpu field, which calls back into
the branch tracer.

The branch tracer has its own recursive checks, but uses a per cpu
variable to implement it. If retrieving the per cpu variable calls
back into the branch tracer, you can see how things will break.

Instead of using a per cpu variable, use the trace_recursion field
of the current task struct. Simply set a bit when entering the
branch tracing and clear it when leaving. If the bit is set on
entry, just don't do the tracing.

There's also the case with lockdep, as the local_irq_save() called
before the recursion can also trigger code that can call back into
the function. Changing that to a raw_local_irq_save() will protect
that as well.

This prevents the recursion and the inevitable crash that follows.

Link: http://lkml.kernel.org/r/20150630141803.GA28071@wfg-t540p.sh.intel.comReported-by: Fengguang Wu <fengguang.wu@intel.com>
Tested-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

commit e8e94ed6 upstream.

In order to get iio-hwmon support, the lradc must be declared as an
iio provider. So fix this issue by adding the #io-channel-cells property.
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Fixes: bd798f9c ("ARM: dts: mxs: Add iio-hwmon to mx23 soc")
Reviewed-by: Marek Vasut <marex@denx.de>
Reviewed-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

commit bb8bd38b upstream.

bio_integrity_alloc() and bio_integrity_free() assume that if a bio was
allocated from a bioset that that bioset also had its bio_integrity_pool
allocated using bioset_integrity_create().  This is a very bad
assumption given that bioset_create() and bioset_integrity_create() are
completely disjoint.  Not all callers of bioset_create() have been
trained to also call bioset_integrity_create() -- and they may not care
to be.

Fix this by falling back to kmalloc'ing 'struct bio_integrity_payload'
rather than force all bioset consumers to (wastefully) preallocate a
bio_integrity_pool that they very likely won't actually need (given the
niche nature of the current block integrity support).

Otherwise, a NULL pointer "Kernel BUG" with a trace like the following
will be observed (as seen on s390x using zfcp storage) because dm-io
doesn't use bioset_integrity_create() when creating its bioset:

    [  791.643338] Call Trace:
    [  791.643339] ([<00000003df98b848>] 0x3df98b848)
    [  791.643341]  [<00000000002c5de8>] bio_integrity_alloc+0x48/0xf8
    [  791.643348]  [<00000000002c6486>] bio_integrity_prep+0xae/0x2f0
    [  791.643349]  [<0000000000371e38>] blk_queue_bio+0x1c8/0x3d8
    [  791.643355]  [<000000000036f8d0>] generic_make_request+0xc0/0x100
    [  791.643357]  [<000000000036f9b2>] submit_bio+0xa2/0x198
    [  791.643406]  [<000003ff801f9774>] dispatch_io+0x15c/0x3b0 [dm_mod]
    [  791.643419]  [<000003ff801f9b3e>] dm_io+0x176/0x2f0 [dm_mod]
    [  791.643423]  [<000003ff8074b28a>] do_reads+0x13a/0x1a8 [dm_mirror]
    [  791.643425]  [<000003ff8074b43a>] do_mirror+0x142/0x298 [dm_mirror]
    [  791.643428]  [<0000000000154fca>] process_one_work+0x18a/0x3f8
    [  791.643432]  [<000000000015598a>] worker_thread+0x132/0x3b0
    [  791.643435]  [<000000000015d49a>] kthread+0xd2/0xd8
    [  791.643438]  [<00000000005bc0ca>] kernel_thread_starter+0x6/0xc
    [  791.643446]  [<00000000005bc0c4>] kernel_thread_starter+0x0/0xc
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

commit 01447e9f upstream.

legacy setcrtc ioctl does take a 32 bit value which might indeed
overflow

the checks of crtc_req->x > INT_MAX and crtc_req->y > INT_MAX aren't
needed any more with this

v2: -polish the annotation according to Daniel's comment

Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Zhao Junwang <zhjwpku@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

commit 41315b79 upstream.

Rather than (incompletely [0]) re-implementing drm_gem_mmap() and
drm_gem_mmap_obj() helpers, call them directly from the rockchip mmap
routines.

Once the core functions return successfully, the rockchip mmap routines
can still use dma_mmap_attrs() to simply mmap the entire buffer.

[0] Previously, we were performing the mmap() without first taking a
reference on the underlying gem buffer.  This could leak ptes if the gem
object is destroyed while userspace is still holding the mapping.
Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

commit f9c87a6f upstream.

If the kernel is compiled with gcc 5.1 and the XZ compression option
the decompress_kernel function calls _sclp_print_early in 64-bit mode
while the content of the upper register half of %r6 is non-zero.
This causes a specification exception on the servc instruction in
_sclp_servc.

The _sclp_print_early function saves and restores the upper registers
halves but it fails to clear them for the 31-bit code of the mini sclp
driver.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

commit 8515bac0 upstream.

Mass storage function created via configfs always reports eight LUNs
to the hosts even if only one LUN has been configured.  Adjust the
number when the USB function is allocated based on LUNs that user
has created.
Tested-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

commit be9d3988 upstream.

Currently, we're calling musb_start() twice for DRD ports
in some situations. This has been observed to cause enumeration
issues after suspend/resume cycles with AM335x.

In order to fix the problem, we just have to fix the check
on musb_has_gadget() so that it only returns true if
current mode is Host and ignore the fact that we have or
not a gadget driver loaded.

Fixes: ae44df2e (usb: musb: call musb_start() only once in OTG mode)
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Tested-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

commit 1c751879 upstream.

Allocate memory using GFP_NOIO when deleting a btree.  dm_btree_del()
can be called via an ioctl and we don't want to recurse into the FS or
block layer.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

commit f98a7aa8 upstream.

Add the USB serial console device ID for Aruba Networks 7xxx series
controllers which have a USB port for their serial console.
Signed-off-by: Peter Sanford <peter@sanford.io>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

commit f6d7fb37 upstream.

Add device Olivetti Olicard 300 (Network Connect: MT6225) - IDs 2020:4000.

T:  Bus=01 Lev=02 Prnt=04 Port=00 Cnt=01 Dev#= 10 Spd=480 MxCh= 0
D:  Ver= 2.00 Cls=ef(misc ) Sub=02 Prot=01 MxPS=64 #Cfgs=  1
P:  Vendor=2020 ProdID=4000 Rev=03.00
S:  Manufacturer=Network Connect
S:  Product=MT6225
C:  #Ifs= 7 Cfg#= 1 Atr=a0 MxPwr=500mA
I:  If#= 0 Alt= 0 #EPs= 1 Cls=02(commc) Sub=0e Prot=00 Driver=cdc_mbim
I:  If#= 1 Alt= 1 #EPs= 2 Cls=0a(data ) Sub=00 Prot=02 Driver=cdc_mbim
I:  If#= 2 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=02 Prot=01 Driver=option
I:  If#= 3 Alt= 0 #EPs= 2 Cls=ff(vend.) Sub=00 Prot=00 Driver=option
I:  If#= 4 Alt= 0 #EPs= 2 Cls=ff(vend.) Sub=00 Prot=00 Driver=option
I:  If#= 5 Alt= 0 #EPs= 2 Cls=ff(vend.) Sub=00 Prot=00 Driver=option
I:  If#= 6 Alt= 0 #EPs= 2 Cls=08(stor.) Sub=06 Prot=50 Driver=usb-storage
Signed-off-by: Claudio Cappelli <claudio.cappelli.linux@gmail.com>
Suggested-by: Lars Melin <larsm17@gmail.com>
[johan: amend commit message with devices info ]
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

commit acb33cc5 upstream.

dma_unmap_sg() is being called twice after completing the
task. Looks like this is a copy paste error when creating
des driver.
With this the following warn appears during boot:

[    4.210457] ------------[ cut here ]------------
[    4.215114] WARNING: CPU: 0 PID: 0 at lib/dma-debug.c:1080 check_unmap+0x710/0x9a0()
[    4.222899] omap-des 480a5000.des: DMA-API: device driver tries to free DMA memory it has not allocated [device address=0x00000000ab2ce000] [size=8 bytes]
[    4.236785] Modules linked in:
[    4.239860] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.14.39-02999-g1bc045a-dirty #182
[    4.247918] [<c001678c>] (unwind_backtrace) from [<c0012574>] (show_stack+0x10/0x14)
[    4.255710] [<c0012574>] (show_stack) from [<c05a37e8>] (dump_stack+0x84/0xb8)
[    4.262977] [<c05a37e8>] (dump_stack) from [<c0046464>] (warn_slowpath_common+0x68/0x8c)
[    4.271107] [<c0046464>] (warn_slowpath_common) from [<c004651c>] (warn_slowpath_fmt+0x30/0x40)
[    4.279854] [<c004651c>] (warn_slowpath_fmt) from [<c02d50a4>] (check_unmap+0x710/0x9a0)
[    4.287991] [<c02d50a4>] (check_unmap) from [<c02d5478>] (debug_dma_unmap_sg+0x90/0x19c)
[    4.296128] [<c02d5478>] (debug_dma_unmap_sg) from [<c04a77d8>] (omap_des_done_task+0x1cc/0x3e4)
[    4.304963] [<c04a77d8>] (omap_des_done_task) from [<c004a090>] (tasklet_action+0x84/0x124)
[    4.313370] [<c004a090>] (tasklet_action) from [<c004a4ac>] (__do_softirq+0xf0/0x20c)
[    4.321235] [<c004a4ac>] (__do_softirq) from [<c004a840>] (irq_exit+0x98/0xec)
[    4.328500] [<c004a840>] (irq_exit) from [<c000f9ac>] (handle_IRQ+0x50/0xb0)
[    4.335589] [<c000f9ac>] (handle_IRQ) from [<c0008688>] (gic_handle_irq+0x28/0x5c)

Removing the duplicate call to dma_unmap_sg().
Reported-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

commit 97709069 upstream.

ARC kernels have historically been built with -O3, despite top level
Makefile defaulting to -O2. This was facilitated by implicitly ordering
of arch makefile include AFTER top level assigned -O2.

An upstream fix to top level a1c48bb1 ("Makefile: Fix unrecognized
cross-compiler command line options") changed the ordering, making ARC
-O3 defunct.

Fix that by NOT relying on any ordering whatsoever and use the proper
arch override facility now present in kbuild (ARCH_*FLAGS)

Depends-on: ("kbuild: Allow arch Makefiles to override {cpp,ld,c}flags")
Suggested-by: Michal Marek <mmarek@suse.cz>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

commit 61754c18 upstream.

Since commit a1c48bb1 (Makefile: Fix unrecognized cross-compiler command
line options), the arch Makefile is included earlier by the main
Makefile, preventing the arc architecture to set its -O3 compiler
option. Since there might be more use cases for an arch Makefile to
fine-tune the options, add support for ARCH_CPPFLAGS, ARCH_AFLAGS and
ARCH_CFLAGS variables that are appended to the respective kbuild
variables. The user still has the final say via the KCPPFLAGS, KAFLAGS
and KCFLAGS variables.
Reported-by: Vineet Gupta <Vineet.Gupta1@synopsys.com>
Signed-off-by: Michal Marek <mmarek@suse.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

commit a822c83e upstream.

Given the pool's cell_sort_array holds 8192 pointers it triggers an
order 5 allocation via kmalloc.  This order 5 allocation is prone to
failure as system memory gets more fragmented over time.

Fix this by allocating the cell_sort_array using vmalloc.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

commit 4c7e3093 upstream.

redistribute3() shares entries out across 3 nodes.  Some entries were
being moved the wrong way, breaking the ordering.  This manifested as a
BUG() in dm-btree-remove.c:shift() when entries were removed from the
btree.

For additional context see:
https://www.redhat.com/archives/dm-devel/2015-May/msg00113.htmlSigned-off-by: Dennis Yang <shinrairis@gmail.com>
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

commit 8d05abfa upstream.

only SAMP_FREQ is writable

Will lead to SAMP_FREQ being written by any attempt to write
to the other exported attributes and hence a rather unexpected
result!
Signed-off-by: Peter Meerwald <pmeerw@pmeerw.net>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

commit 0689a86a upstream.

The Steinberg MI2 and MI4 interfaces are compatible with the USB class
audio spec, but the MIDI part of the devices is reported as a vendor
specific interface.

This patch adds entries to quirks-table.h to recognize the MIDI
endpoints. Audio functionality was already working and is unaffected by
this change.
Signed-off-by: Dominic Sacré <dominic.sacre@gmx.de>
Signed-off-by: Albert Huitsing <albert@huitsing.nl>
Acked-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

commit 33361e56 upstream.

the millisecond values in tcs3414_times should be checked against
val2, not val, which is always zero.
Signed-off-by: Peter Meerwald <pmeerw@pmeerw.net>
Reported-by: Stephan Kleisinger <stephan.kleisinger@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

commit 2ab5f39b upstream.

The DT-Property "atmel,adc-startup-time" is stored in an u8 for a microsecond
value. When trying to increase the value of STARTUP in Register AT91_ADC_MR
some higher values can't be reached.

Change the type in function parameter and private structure field from u8 to
u32.
Signed-off-by: Jan Leupold <leupold@rsi-elektrotechnik.de>
[nicolas.ferre@atmel.com: change commit message, increase u16 to u32 for startup time]
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

commit adfa9698 upstream.

The value sent on the SPI bus is shifted by an erroneous number of bits.
The shift value was already computed in the iio_chan_spec structure and
hence subtracting this argument to 16 yields an erroneous data position
in the SPI stream.
Signed-off-by: JM Friedt <jmfriedt@femto-st.fr>
Acked-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

commit 6a3c45bb upstream.

The gyroscope needs IIO_VAL_INT_PLUS_NANO for the scale channel and
unless specified write returns MICRO by default.
This needs to be properly specified so that write operations into scale
have the expected behaviour.
Signed-off-by: Adriana Reus <adriana.reus@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

commit 6c0d48cb upstream.

Since commit 1c6c6952 ("genirq: Reject bogus threaded irq requests")
threaded IRQs without a primary handler need to be requested with
IRQF_ONESHOT, otherwise the request will fail.

So pass the IRQF_ONESHOT flag in this case.

The semantic patch that makes this change is available
in scripts/coccinelle/misc/irqf_oneshot.cocci.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

commit dc7b8d98 upstream.

The module-data is currently missing. This includes the license-information
which makes the driver taint the kernel and miss symbols when compiled as
module.

Fixes: 44d6f2ef ("iio: adc: add driver for Rockchip saradc")
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

commit 0f4f2afd upstream.

While proving lock, the following warning happens
and it is fixed after initializing lock in the setup
function

INFO: trying to register non-static key.
the code is fine but needs lockdep annotation.
turning off the locking correctness validator.
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.10.27-02861-g39df285-dirty #33
[<c00154ac>] (unwind_backtrace+0x0/0xf4) from [<c0011b50>] (show_stack+0x10/0x14)
[<c0011b50>] (show_stack+0x10/0x14) from [<c00689ac>] (__lock_acquire+0x900/0xb14)
[<c00689ac>] (__lock_acquire+0x900/0xb14) from [<c0069394>] (lock_acquire+0x68/0x7c)
[<c0069394>] (lock_acquire+0x68/0x7c) from [<c04958f8>] (_raw_spin_lock_irqsave+0x48/0x5c)
[<c04958f8>] (_raw_spin_lock_irqsave+0x48/0x5c) from [<c0381e6c>] (clk_gate_endisable+0x28/0x88)
[<c0381e6c>] (clk_gate_endisable+0x28/0x88) from [<c0381ee0>] (clk_gate_enable+0xc/0x14)
[<c0381ee0>] (clk_gate_enable+0xc/0x14) from [<c0386c68>] (flexgen_enable+0x28/0x40)
[<c0386c68>] (flexgen_enable+0x28/0x40) from [<c037f260>] (__clk_enable+0x5c/0x9c)
[<c037f260>] (__clk_enable+0x5c/0x9c) from [<c037f558>] (clk_enable+0x18/0x2c)
[<c037f558>] (clk_enable+0x18/0x2c) from [<c064a1dc>] (st_lpc_of_register+0xc0/0x248)
[<c064a1dc>] (st_lpc_of_register+0xc0/0x248) from [<c0649e44>] (clocksource_of_init+0x34/0x58)
[<c0649e44>] (clocksource_of_init+0x34/0x58) from [<c0637ddc>] (sti_timer_init+0x10/0x18)
[<c0637ddc>] (sti_timer_init+0x10/0x18) from [<c06343f8>] (time_init+0x20/0x30)
[<c06343f8>] (time_init+0x20/0x30) from [<c0632984>] (start_kernel+0x20c/0x2e8)
[<c0632984>] (start_kernel+0x20c/0x2e8) from [<40008074>] (0x40008074)
Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: Gabriel Fernandez <gabriel.fernandez@linaro.org>
Fixes: b1165170 ("clk: st: STiH407: Support for Flexgen Clocks")
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

commit 398f7456 upstream.

John Stultz reports an RCU splat on boot with ARM ipi trace
events enabled.

===============================
[ INFO: suspicious RCU usage. ]
4.1.0-rc7-00033-gb5bed2f #153 Not tainted
-------------------------------
include/trace/events/ipi.h:68 suspicious rcu_dereference_check() usage!

other info that might help us debug this:

RCU used illegally from idle CPU!
rcu_scheduler_active = 1, debug_locks = 0
RCU used illegally from extended quiescent state!
no locks held by swapper/0/0.

stack backtrace:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.1.0-rc7-00033-gb5bed2f #153
Hardware name: Qualcomm (Flattened Device Tree)
[<c0216b08>] (unwind_backtrace) from [<c02136e8>] (show_stack+0x10/0x14)
[<c02136e8>] (show_stack) from [<c075e678>] (dump_stack+0x70/0xbc)
[<c075e678>] (dump_stack) from [<c0215a80>] (handle_IPI+0x428/0x604)
[<c0215a80>] (handle_IPI) from [<c020942c>] (gic_handle_irq+0x54/0x5c)
[<c020942c>] (gic_handle_irq) from [<c0766604>] (__irq_svc+0x44/0x7c)
Exception stack(0xc09f3f48 to 0xc09f3f90)
3f40:                   00000001 00000001 00000000 c09f73b8 c09f4528 c0a5de9c
3f60: c076b4f0 00000000 00000000 c09ef108 c0a5cec1 00000001 00000000 c09f3f90
3f80: c026bf60 c0210ab8 20000113 ffffffff
[<c0766604>] (__irq_svc) from [<c0210ab8>] (arch_cpu_idle+0x20/0x3c)
[<c0210ab8>] (arch_cpu_idle) from [<c02647f0>] (cpu_startup_entry+0x2c0/0x5dc)
[<c02647f0>] (cpu_startup_entry) from [<c099bc1c>] (start_kernel+0x358/0x3c4)
[<c099bc1c>] (start_kernel) from [<8020807c>] (0x8020807c)

At this point in the IPI handling path we haven't called
irq_enter() yet, so RCU doesn't know that we're about to exit
idle and properly warns that we're using RCU from an idle CPU.
Use trace_ipi_entry_rcuidle() instead of trace_ipi_entry() so
that RCU is informed about our exit from idle.

Fixes: 365ec7b1 ("ARM: add IPI tracepoints")
Reported-by: John Stultz <john.stultz@linaro.org>
Tested-by: John Stultz <john.stultz@linaro.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

commit 3be6d8ce upstream.

This patch fixes the mux bit-setting for ClockgenA9.
Signed-off-by: Gabriel Fernandez <gabriel.fernandez@linaro.org>
Fixes: 13e6f2da ("clk: st: STiH407: Support for A9 MUX Clocks")
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

commit 56551da9 upstream.

Incorrect register offset used for sthi407 clockgenC
Signed-off-by: Pankaj Dev <pankaj.dev@st.com>
Signed-off-by: Gabriel Fernandez <gabriel.fernandez@linaro.org>
Fixes: 51306d56 ("clk: st: STiH407: Support for clockgenC0")
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

commit 6d451367 upstream.

Since the parent rate has been recalculated, pixel RCG clock
should rely on it to find the correct M/N values during set_rate,
instead of calling __clk_round_rate() to its parent again.
Signed-off-by: Hai Li <hali@codeaurora.org>
Tested-by: Archit Taneja <architt@codeaurora.org>
Fixes: 99cbd064 ("clk: qcom: Support display RCG clocks")
[sboyd@codeaurora.org: Silenced unused parent variable warning]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
[ kamal: backport to 3.19-stable: context ]
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

commit 75a6f82a upstream.

	Normally opening a file, unlinking it and then closing will have
the inode freed upon close() (provided that it's not otherwise busy and
has no remaining links, of course).  However, there's one case where that
does *not* happen.  Namely, if you open it by fhandle with cold dcache,
then unlink() and close().

	In normal case you get d_delete() in unlink(2) notice that dentry
is busy and unhash it; on the final dput() it will be forcibly evicted from
dcache, triggering iput() and inode removal.  In this case, though, we end
up with *two* dentries - disconnected (created by open-by-fhandle) and
regular one (used by unlink()).  The latter will have its reference to inode
dropped just fine, but the former will not - it's considered hashed (it
is on the ->s_anon list), so it will stay around until the memory pressure
will finally do it in.  As the result, we have the final iput() delayed
indefinitely.  It's trivial to reproduce -

void flush_dcache(void)
{
        system("mount -o remount,rw /");
}

static char buf[20 * 1024 * 1024];

main()
{
        int fd;
        union {
                struct file_handle f;
                char buf[MAX_HANDLE_SZ];
        } x;
        int m;

        x.f.handle_bytes = sizeof(x);
        chdir("/root");
        mkdir("foo", 0700);
        fd = open("foo/bar", O_CREAT | O_RDWR, 0600);
        close(fd);
        name_to_handle_at(AT_FDCWD, "foo/bar", &x.f, &m, 0);
        flush_dcache();
        fd = open_by_handle_at(AT_FDCWD, &x.f, O_RDWR);
        unlink("foo/bar");
        write(fd, buf, sizeof(buf));
        system("df .");			/* 20Mb eaten */
        close(fd);
        system("df .");			/* should've freed those 20Mb */
        flush_dcache();
        system("df .");			/* should be the same as #2 */
}

will spit out something like
Filesystem     1K-blocks   Used Available Use% Mounted on
/dev/root         322023 303843      1131 100% /
Filesystem     1K-blocks   Used Available Use% Mounted on
/dev/root         322023 303843      1131 100% /
Filesystem     1K-blocks   Used Available Use% Mounted on
/dev/root         322023 283282     21692  93% /
- inode gets freed only when dentry is finally evicted (here we trigger
than by remount; normally it would've happened in response to memory
pressure hell knows when).
Acked-by: J. Bruce Fields <bfields@fieldses.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[ kamal: backport to 3.19-stable: no fast_dput() ]
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

commit 0a73d0a2 upstream.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

commit 01ab6057 upstream.

The increased use of pdtlb/pitlb instructions seemed to increase the
frequency of random segmentation faults building packages. Further, we
had a number of cases where TLB inserts would repeatedly fail and all
forward progress would stop. The Haskell ghc package caused a lot of
trouble in this area. The final indication of a race in pte handling was
this syslog entry on sibaris (C8000):

 swap_free: Unused swap offset entry 00000004
 BUG: Bad page map in process mysqld  pte:00000100 pmd:019bbec5
 addr:00000000ec464000 vm_flags:00100073 anon_vma:0000000221023828 mapping: (null) index:ec464
 CPU: 1 PID: 9176 Comm: mysqld Not tainted 4.0.0-2-parisc64-smp #1 Debian 4.0.5-1
 Backtrace:
  [<0000000040173eb0>] show_stack+0x20/0x38
  [<0000000040444424>] dump_stack+0x9c/0x110
  [<00000000402a0d38>] print_bad_pte+0x1a8/0x278
  [<00000000402a28b8>] unmap_single_vma+0x3d8/0x770
  [<00000000402a4090>] zap_page_range+0xf0/0x198
  [<00000000402ba2a4>] SyS_madvise+0x404/0x8c0

Note that the pte value is 0 except for the accessed bit 0x100. This bit
shouldn't be set without the present bit.

It should be noted that the madvise system call is probably a trigger for many
of the random segmentation faults.

In looking at the kernel code, I found the following problems:

1) The pte_clear define didn't take TLB lock when clearing a pte.
2) We didn't test pte present bit inside lock in exception support.
3) The pte and tlb locks needed to merged in order to ensure consistency
between page table and TLB. This also has the effect of serializing TLB
broadcasts on SMP systems.

The attached change implements the above and a few other tweaks to try
to improve performance. Based on the timing code, TLB purges are very
slow (e.g., ~ 209 cycles per page on rp3440). Thus, I think it
beneficial to test the split_tlb variable to avoid duplicate purges.
Probably, all PA 2.0 machines have combined TLBs.

I dropped using __flush_tlb_range in flush_tlb_mm as I realized all
applications and most threads have a stack size that is too large to
make this useful. I added some comments to this effect.

Since implementing 1 through 3, I haven't had any random segmentation
faults on mx3210 (rp3440) in about one week of building code and running
as a Debian buildd.
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>