prepare for inline kernel building
galaxys2 i777: builtin md4 and dns_resover
build: target is kernel
fix 1st stage ramdisk gen for inline building
always build with integrity check code for crypto module
ramdisk: removed lib/modules dir
Build stage2 initramfs into kernel.

Instead of attaching boot and recovery initramfs to the kernel, with a
header which must be scanned for, insert them into the builtin bootstrap
initramfs as cpio images.

Change-Id: Ifbd81a30b8b2fe4f9443804a6421e083355cc5de
i777: build stage2 initramfs into kernel.

Change-Id: Ie85ea18e93a3f9463ae54d64a219d8d2c51ab640
drm/i915/ringbuffer: Exclude last 2 cachlines of ring on 845g

commit 27c1cbd06a7620b354cbb363834f3bb8df4f410d upstream.

The 845g shares the errata with i830 whereby executing a command
within 2 cachelines of the end of the ringbuffer may cause a GPU hang.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drm/radeon: only add the mm i2c bus if the hw_i2c module param is set

commit 46783150a6552f9513f08e62cfcc07125d6e502b upstream.

It seems it can corrupt the monitor EDID in certain cases on certain
boards when running sensors detect.  It's rarely used anyway outside
of AIW boards.

http://lists.lm-sensors.org/pipermail/lm-sensors/2012-April/035847.html
http://lists.freedesktop.org/archives/xorg/2011-January/052239.html

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
rtlwifi: Add missing DMA buffer unmapping for PCI drivers

commit 673f7786e205c87b5d978c62827b9a66d097bebb upstream.

In https://bugzilla.kernel.org/show_bug.cgi?id=42976, a system with driver
rtl8192se used as an AP suffers from "Out of SW-IOMMU space" errors. These
are caused by the DMA buffers used for beacons never being unmapped.

This bug was also reported at
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/961618

Reported-and-Tested-by: Da Xue <da@lessconfused.com>
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>
ARM: 7384/1: ThumbEE: Disable userspace TEEHBR access for !CONFIG_ARM_THUMBEE

commit 078c04545ba56da21567728a909a496df5ff730d upstream.

Currently when ThumbEE is not enabled (!CONFIG_ARM_THUMBEE) the ThumbEE
register states are not saved/restored at context switch. The default state
of the ThumbEE Ctrl register (TEECR) allows userspace accesses to the
ThumbEE Base Handler register (TEEHBR). This can cause unexpected behaviour
when people use ThumbEE on !CONFIG_ARM_THUMBEE kernels, as well as allowing
covert communication - eg between userspace tasks running inside chroot
jails.

This patch sets up TEECR in order to prevent user-space access to TEEHBR
when !CONFIG_ARM_THUMBEE. In this case, tasks are sent SIGILL if they try to
access TEEHBR.

Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Jonathan Austin <jonathan.austin@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Bluetooth: uart-ldisc: Fix memory leak

This is a partial, self-contained, minimal backport of commit
797fe796c4335b35d95d5326824513befdb5d1e9 upstream which fixes the memory
leak:

Bluetooth: uart-ldisc: Fix memory leak and remove destruct cb

We currently leak the hci_uart object if HCI_UART_PROTO_SET is never set
because the hci-destruct callback will then never be called.  This fix
removes the hci-destruct callback and frees the driver internal private
hci_uart object directly on tty-close. We call hci_unregister_dev() here
so the hci-core will never call our callbacks again (except destruct).
Therefore, we can safely free the driver internal data right away and
set the destruct callback to NULL.

Signed-off-by: David Herrmann <dh.herrmann@googlemail.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Bluetooth: hci_ldisc: fix NULL-pointer dereference on tty_close

commit 33b69bf80a3704d45341928e4ff68b6ebd470686 upstream.

Do not close protocol driver until device has been unregistered.

This fixes a race between tty_close and hci_dev_open which can result in
a NULL-pointer dereference.

The line discipline closes the protocol driver while we may still have
hci_dev_open sleeping on the req_lock mutex resulting in a NULL-pointer
dereference when lock is acquired and hci_init_req called.

Bug is 100% reproducible using hciattach and a disconnected serial port:

0. # hciattach -n ttyO1 any noflow

1. hci_dev_open called from hci_power_on grabs req lock
2. hci_init_req executes but device fails to initialise (times out
   eventually)
3. hci_dev_open is called from hci_sock_ioctl and sleeps on req lock
4. hci_uart_tty_close detaches protocol driver and cancels init req
5. hci_dev_open (1) releases req lock
6. hci_dev_open (3) grabs req lock, calls hci_init_req, which triggers oops
   when request is prepared in hci_uart_send_frame

[  137.201263] Unable to handle kernel NULL pointer dereference at virtual address 00000028
[  137.209838] pgd = c0004000
[  137.212677] [00000028] *pgd=00000000
[  137.216430] Internal error: Oops: 17 [#1]
[  137.220642] Modules linked in:
[  137.223846] CPU: 0    Tainted: G        W     (3.3.0-rc6-dirty #406)
[  137.230529] PC is at __lock_acquire+0x5c/0x1ab0
[  137.235290] LR is at lock_acquire+0x9c/0x128
[  137.239776] pc : [<c0071490>]    lr : [<c00733f8>]    psr: 20000093
[  137.239776] sp : cf869dd8  ip : c0529554  fp : c051c730
[  137.251800] r10: 00000000  r9 : cf8673c0  r8 : 00000080
[  137.257293] r7 : 00000028  r6 : 00000002  r5 : 00000000  r4 : c053fd70
[  137.264129] r3 : 00000000  r2 : 00000000  r1 : 00000000  r0 : 00000001
[  137.270965] Flags: nzCv  IRQs off  FIQs on  Mode SVC_32  ISA ARM  Segment kernel
[  137.278717] Control: 10c5387d  Table: 8f0f4019  DAC: 00000015
[  137.284729] Process kworker/u:1 (pid: 7, stack limit = 0xcf8682e8)
[  137.291229] Stack: (0xcf869dd8 to 0xcf86a000)
[  137.295776] 9dc0:                                                       c0529554 00000000
[  137.304351] 9de0: cf8673c0 cf868000 d03ea1ef cf868000 000001ef 00000470 00000000 00000002
[  137.312927] 9e00: cf8673c0 00000001 c051c730 c00716ec 0000000c 00000440 c0529554 00000001
[  137.321533] 9e20: c051c730 cf868000 d03ea1f3 00000000 c053b978 00000000 00000028 cf868000
[  137.330078] 9e40: 00000000 00000000 00000002 00000000 00000000 c00733f8 00000002 00000080
[  137.338684] 9e60: 00000000 c02a1d50 00000000 00000001 60000013 c0969a1c 60000093 c053b96c
[  137.347259] 9e80: 00000002 00000018 20000013 c02a1d50 cf0ac000 00000000 00000002 cf868000
[  137.355834] 9ea0: 00000089 c0374130 00000002 00000000 c02a1d50 cf0ac000 0000000c cf0fc540
[  137.364410] 9ec0: 00000018 c02a1d50 cf0fc540 00000000 cf0fc540 c0282238 c028220c cf178d80
[  137.372985] 9ee0: 127525d8 c02821cc 9a1fa451 c032727c 9a1fa451 127525d8 cf0fc540 cf0ac4ec
[  137.381561] 9f00: cf0ac000 cf0fc540 cf0ac584 c03285f4 c0328580 cf0ac4ec cf85c740 c05510cc
[  137.390136] 9f20: ce825400 c004c914 00000002 00000000 c004c884 ce8254f5 cf869f48 00000000
[  137.398712] 9f40: c0328580 ce825415 c0a7f914 c061af64 00000000 c048cf3c cf8673c0 cf85c740
[  137.407287] 9f60: c05510cc c051a66c c05510ec c05510c4 cf85c750 cf868000 00000089 c004d6ac
[  137.415863] 9f80: 00000000 c0073d14 00000001 cf853ed8 cf85c740 c004d558 00000013 00000000
[  137.424438] 9fa0: 00000000 00000000 00000000 c00516b0 00000000 00000000 cf85c740 00000000
[  137.433013] 9fc0: 00000001 dead4ead ffffffff ffffffff c0551674 00000000 00000000 c0450aa4
[  137.441589] 9fe0: cf869fe0 cf869fe0 cf853ed8 c005162c c0013b30 c0013b30 00ffff00 00ffff00
[  137.450164] [<c0071490>] (__lock_acquire+0x5c/0x1ab0) from [<c00733f8>] (lock_acquire+0x9c/0x128)
[  137.459503] [<c00733f8>] (lock_acquire+0x9c/0x128) from [<c0374130>] (_raw_spin_lock_irqsave+0x44/0x58)
[  137.469360] [<c0374130>] (_raw_spin_lock_irqsave+0x44/0x58) from [<c02a1d50>] (skb_queue_tail+0x18/0x48)
[  137.479339] [<c02a1d50>] (skb_queue_tail+0x18/0x48) from [<c0282238>] (h4_enqueue+0x2c/0x34)
[  137.488189] [<c0282238>] (h4_enqueue+0x2c/0x34) from [<c02821cc>] (hci_uart_send_frame+0x34/0x68)
[  137.497497] [<c02821cc>] (hci_uart_send_frame+0x34/0x68) from [<c032727c>] (hci_send_frame+0x50/0x88)
[  137.507171] [<c032727c>] (hci_send_frame+0x50/0x88) from [<c03285f4>] (hci_cmd_work+0x74/0xd4)
[  137.516204] [<c03285f4>] (hci_cmd_work+0x74/0xd4) from [<c004c914>] (process_one_work+0x1a0/0x4ec)
[  137.525604] [<c004c914>] (process_one_work+0x1a0/0x4ec) from [<c004d6ac>] (worker_thread+0x154/0x344)
[  137.535278] [<c004d6ac>] (worker_thread+0x154/0x344) from [<c00516b0>] (kthread+0x84/0x90)
[  137.543975] [<c00516b0>] (kthread+0x84/0x90) from [<c0013b30>] (kernel_thread_exit+0x0/0x8)
[  137.552734] Code: e59f4e5c e5941000 e3510000 0a000031 (e5971000)
[  137.559234] ---[ end trace 1b75b31a2719ed1e ]---

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ia64: fix futex_atomic_cmpxchg_inatomic()

commit c76f39bddb84f93f70a5520d9253ec0317bec216 upstream.

Michel Lespinasse cleaned up the futex calling conventions in commit
37a9d912b24f ("futex: Sanitize cmpxchg_futex_value_locked API").

But the ia64 implementation was subtly broken.  Gcc does not know that
register "r8" will be updated by the fault handler if the cmpxchg
instruction takes an exception.  So it feels safe in letting the
initialization of r8 slide to after the cmpxchg.  Result: we always
return 0 whether the user address faulted or not.

Fix by moving the initialization of r8 into the __asm__ code so gcc
won't move it.

Reported-by: <emeric.maschino@gmail.com>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=42757
Tested-by: <emeric.maschino@gmail.com>
Acked-by: Michel Lespinasse <walken@google.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/rtc/rtc-pl031.c: enable clock on all ST variants

commit 2f3972168353d355854d6381f1f360ce83b723e5 upstream.

The ST variants of the PL031 all require bit 26 in the control register
to be set before they work properly.  Discovered this when testing on
the Nomadik board where it would suprisingly just stand still.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Mian Yousaf Kaukab <mian.yousaf.kaukab@stericsson.com>
Cc: Alessandro Rubini <rubini@unipv.it>
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>
hugetlb: fix race condition in hugetlb_fault()

commit 66aebce747eaf9bc456bf1f1b217d8db843031d0 upstream.

The race is as follows:

Suppose a multi-threaded task forks a new process (on cpu A), thus
bumping up the ref count on all the pages.  While the fork is occurring
(and thus we have marked all the PTEs as read-only), another thread in
the original process (on cpu B) tries to write to a huge page, taking an
access violation from the write-protect and calling hugetlb_cow().  Now,
suppose the fork() fails.  It will undo the COW and decrement the ref
count on the pages, so the ref count on the huge page drops back to 1.
Meanwhile hugetlb_cow() also decrements the ref count by one on the
original page, since the original address space doesn't need it any
more, having copied a new page to replace the original page.  This
leaves the ref count at zero, and when we call unlock_page(), we panic.

	fork on CPU A				fault on CPU B
	=============				==============
	...
	down_write(&parent->mmap_sem);
	down_write_nested(&child->mmap_sem);
	...
	while duplicating vmas
		if error
			break;
	...
	up_write(&child->mmap_sem);
	up_write(&parent->mmap_sem);		...
						down_read(&parent->mmap_sem);
						...
						lock_page(page);
						handle COW
						page_mapcount(old_page) == 2
						alloc and prepare new_page
	...
	handle error
	page_remove_rmap(page);
	put_page(page);
	...
						fold new_page into pte
						page_remove_rmap(page);
						put_page(page);
						...
				oops ==>	unlock_page(page);
						up_read(&parent->mmap_sem);

The solution is to take an extra reference to the page while we are
holding the lock on it.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.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>
staging: iio: hmc5843: Fix crash in probe function.

commit 62d2feb9803f18c4e3c8a1a2c7e30a54df8a1d72 upstream.

Fix crash after issuing:
	echo hmc5843 0x1e > /sys/class/i2c-dev/i2c-2/device/new_device

	[   37.180999] device: '2-001e': device_add
	[   37.188293] bus: 'i2c': add device 2-001e
	[   37.194549] PM: Adding info for i2c:2-001e
	[   37.200958] bus: 'i2c': driver_probe_device: matched device 2-001e with driver hmc5843
	[   37.210815] bus: 'i2c': really_probe: probing driver hmc5843 with device 2-001e
	[   37.224884] HMC5843 initialized
	[   37.228759] ------------[ cut here ]------------
	[   37.233612] kernel BUG at mm/slab.c:505!
	[   37.237701] Internal error: Oops - BUG: 0 [#1] PREEMPT
	[   37.243103] Modules linked in:
	[   37.246337] CPU: 0    Not tainted  (3.3.1-gta04+ #28)
	[   37.251647] PC is at kfree+0x84/0x144
	[   37.255493] LR is at kfree+0x20/0x144
	[   37.259338] pc : [<c00b408c>]    lr : [<c00b4028>]    psr: 40000093
	[   37.259368] sp : de249cd8  ip : 0000000c  fp : 00000090
	[   37.271362] r10: 0000000a  r9 : de229eac  r8 : c0236274
	[   37.276855] r7 : c09d6490  r6 : a0000013  r5 : de229c00  r4 : de229c10
	[   37.283691] r3 : c0f00218  r2 : 00000400  r1 : c0eea000  r0 : c00b4028
	[   37.290527] Flags: nZcv  IRQs off  FIQs on  Mode SVC_32  ISA ARM  Segment user
	[   37.298095] Control: 10c5387d  Table: 9e1d0019  DAC: 00000015
	[   37.304107] Process sh (pid: 91, stack limit = 0xde2482f0)
	[   37.309844] Stack: (0xde249cd8 to 0xde24a000)
	[   37.314422] 9cc0:                                                       de229c10 de229c00
	[   37.322998] 9ce0: de229c10 ffffffea 00000005 c0236274 de140a80 c00b4798 dec00080 de140a80
	[   37.331573] 9d00: c032f37c dec00080 000080d0 00000001 de229c00 de229c10 c048d578 00000005
	[   37.340148] 9d20: de229eac 0000000a 00000090 c032fa40 00000001 00000000 00000001 de229c10
	[   37.348724] 9d40: de229eac 00000029 c075b558 00000001 00000003 00000004 de229c10 c048d594
	[   37.357299] 9d60: 00000000 60000013 00000018 205b0007 37332020 3432322e 5d343838 c0060020
	[   37.365905] 9d80: de251600 00000001 00000000 de251600 00000001 c0065a84 de229c00 de229c48
	[   37.374481] 9da0: 00000006 0048d62c de229c38 de229c00 de229c00 de1f6c00 de1f6c20 00000001
	[   37.383056] 9dc0: 00000000 c048d62c 00000000 de229c00 de229c00 de1f6c00 de1f6c20 00000001
	[   37.391632] 9de0: 00000000 c048d62c 00000000 c0330164 00000000 de1f6c20 c048d62c de1f6c00
	[   37.400207] 9e00: c0330078 de1f6c04 c078d714 de189b58 00000000 c02ccfd8 de1f6c20 c0795f40
	[   37.408782] 9e20: c0238330 00000000 00000000 c02381a8 de1b9fc0 de1f6c20 de1f6c20 de249e48
	[   37.417358] 9e40: c0238330 c0236bb0 decdbed8 de7d0f14 de1f6c20 de1f6c20 de1f6c54 de1f6c20
	[   37.425933] 9e60: 00000000 c0238030 de1f6c20 c078d7bc de1f6c20 c02377ec de1f6c20 de1f6c28
	[   37.434509] 9e80: dee64cb0 c0236138 c047c554 de189b58 00000000 c004b45c de1f6c20 de1f6cd8
	[   37.443084] 9ea0: c0edfa6c de1f6c00 dee64c68 de1f6c04 de1f6c20 dee64cb8 c047c554 de189b58
	[   37.451690] 9ec0: 00000000 c02cd634 dee64c68 de249ef4 de23b008 dee64cb0 0000000d de23b000
	[   37.460266] 9ee0: de23b007 c02cd78c 00000002 00000000 00000000 35636d68 00333438 00000000
	[   37.468841] 9f00: 00000000 00000000 001e0000 00000000 00000000 00000000 00000000 0a10cec0
	[   37.477416] 9f20: 00000002 de249f80 0000000d dee62990 de189b40 c0234d88 0000000d c010c354
	[   37.485992] 9f40: 0000000d de210f28 000acc88 de249f80 0000000d de248000 00000000 c00b7bf8
	[   37.494567] 9f60: de210f28 000acc88 de210f28 000acc88 00000000 00000000 0000000d c00b7ed8
	[   37.503143] 9f80: 00000000 00000000 0000000d 00000000 0007fa28 0000000d 000acc88 00000004
	[   37.511718] 9fa0: c000e544 c000e380 0007fa28 0000000d 00000001 000acc88 0000000d 00000000
	[   37.520294] 9fc0: 0007fa28 0000000d 000acc88 00000004 00000001 00000020 00000002 00000000
	[   37.528869] 9fe0: 00000000 beab8624 0000ea05 b6eaebac 600d0010 00000001 00000000 00000000
	[   37.537475] [<c00b408c>] (kfree+0x84/0x144) from [<c0236274>] (device_add+0x530/0x57c)
	[   37.545806] [<c0236274>] (device_add+0x530/0x57c) from [<c032fa40>] (iio_device_register+0x8c8/0x990)
	[   37.555480] [<c032fa40>] (iio_device_register+0x8c8/0x990) from [<c0330164>] (hmc5843_probe+0xec/0x114)
	[   37.565338] [<c0330164>] (hmc5843_probe+0xec/0x114) from [<c02ccfd8>] (i2c_device_probe+0xc4/0xf8)
	[   37.574737] [<c02ccfd8>] (i2c_device_probe+0xc4/0xf8) from [<c02381a8>] (driver_probe_device+0x118/0x218)
	[   37.584777] [<c02381a8>] (driver_probe_device+0x118/0x218) from [<c0236bb0>] (bus_for_each_drv+0x4c/0x84)
	[   37.594818] [<c0236bb0>] (bus_for_each_drv+0x4c/0x84) from [<c0238030>] (device_attach+0x78/0xa4)
	[   37.604125] [<c0238030>] (device_attach+0x78/0xa4) from [<c02377ec>] (bus_probe_device+0x28/0x9c)
	[   37.613433] [<c02377ec>] (bus_probe_device+0x28/0x9c) from [<c0236138>] (device_add+0x3f4/0x57c)
	[   37.622650] [<c0236138>] (device_add+0x3f4/0x57c) from [<c02cd634>] (i2c_new_device+0xf8/0x19c)
	[   37.631805] [<c02cd634>] (i2c_new_device+0xf8/0x19c) from [<c02cd78c>] (i2c_sysfs_new_device+0xb4/0x130)
	[   37.641754] [<c02cd78c>] (i2c_sysfs_new_device+0xb4/0x130) from [<c0234d88>] (dev_attr_store+0x18/0x24)
	[   37.651611] [<c0234d88>] (dev_attr_store+0x18/0x24) from [<c010c354>] (sysfs_write_file+0x10c/0x140)
	[   37.661193] [<c010c354>] (sysfs_write_file+0x10c/0x140) from [<c00b7bf8>] (vfs_write+0xb0/0x178)
	[   37.670410] [<c00b7bf8>] (vfs_write+0xb0/0x178) from [<c00b7ed8>] (sys_write+0x3c/0x68)
	[   37.678833] [<c00b7ed8>] (sys_write+0x3c/0x68) from [<c000e380>] (ret_fast_syscall+0x0/0x3c)
	[   37.687683] Code: 1593301c e5932000 e3120080 1a000000 (e7f001f2)
	[   37.700775] ---[ end trace aaf805debdb69390 ]---

Client data was assigned to iio_dev structure in probe but in
hmc5843_init_client function casted to private driver data structure which
is wrong. Possibly calling mutex_init(&data->lock); corrupt data
which the lead to above crash.

Signed-off-by: Marek Belisko <marek.belisko@open-nandra.com>
Acked-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty: serial: altera_uart: Check for NULL platform_data in probe.

commit acede70d6561f2d042d9dbb153d9a3469479c0ed upstream.

Follow altera_jtag_uart.  This fixes a crash if there is a mistake in the DTS.

Signed-off-by: Yuriy Kozlov <ykozlov@ptcusa.com>
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
sparc64: Eliminate obsolete __handle_softirq() function

commit 3d3eeb2ef26112a200785e5fca58ec58dd33bf1e upstream.

The invocation of softirq is now handled by irq_exit(), so there is no
need for sparc64 to invoke it on the trap-return path.  In fact, doing so
is a bug because if the trap occurred in the idle loop, this invocation
can result in lockdep-RCU failures.  The problem is that RCU ignores idle
CPUs, and the sparc64 trap-return path to the softirq handlers fails to
tell RCU that the CPU must be considered non-idle while those handlers
are executing.  This means that RCU is ignoring any RCU read-side critical
sections in those handlers, which in turn means that RCU-protected data
can be yanked out from under those read-side critical sections.

The shiny new lockdep-RCU ability to detect RCU read-side critical sections
that RCU is ignoring located this problem.

The fix is straightforward: Make sparc64 stop manually invoking the
softirq handlers.

Reported-by: Meelis Roos <mroos@linux.ee>
Suggested-by: David Miller <davem@davemloft.net>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Meelis Roos <mroos@linux.ee>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>