commit da25311c upstream.

The Schenker XMG C504 is a rebranded Gigabyte P35 v2 laptop.
Therefore it also needs a keyboard reset to detect the Elantech touchpad.
Otherwise the touchpad appears to be dead.

With this patch the touchpad is detected:

$ dmesg | grep -E "(i8042|Elantech|elantech)"

[    2.675399] i8042: PNP: PS/2 Controller [PNP0303:PS2K,PNP0f13:PS2M] at 0x60,0x64 irq 1,12
[    2.680372] i8042: Attempting to reset device connected to KBD port
[    2.789037] serio: i8042 KBD port at 0x60,0x64 irq 1
[    2.791586] serio: i8042 AUX port at 0x60,0x64 irq 12
[    2.813840] input: AT Translated Set 2 keyboard as /devices/platform/i8042/serio0/input/input4
[    3.811431] psmouse serio1: elantech: assuming hardware version 4 (with firmware version 0x361f0e)
[    3.825424] psmouse serio1: elantech: Synaptics capabilities query result 0x00, 0x15, 0x0f.
[    3.839424] psmouse serio1: elantech: Elan sample query result 03, 58, 74
[    3.911349] input: ETPS/2 Elantech Touchpad as /devices/platform/i8042/serio1/input/input6
Signed-off-by: Patrick Scheuring <patrick.scheuring.dev@gmail.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 6d4952d9 upstream.

hw_random carefully avoids using a stack buffer except in
add_early_randomness().  This causes a crash in virtio_rng if
CONFIG_VMAP_STACK=y.
Reported-by: Matt Mullins <mmullins@mmlx.us>
Tested-by: Matt Mullins <mmullins@mmlx.us>
Fixes: d3cc7996 ("hwrng: fetch randomness only after device init")
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 7cb3f921 upstream.

Satish reported a problem with the perm multicast router ports not getting
reenabled after some series of events, in particular if it happens that the
multicast snooping has been disabled and the port goes to disabled state
then it will be deleted from the router port list, but if it moves into
non-disabled state it will not be re-added because the mcast snooping is
still disabled, and enabling snooping later does nothing.

Here are the steps to reproduce, setup br0 with snooping enabled and eth1
added as a perm router (multicast_router = 2):
1. $ echo 0 > /sys/class/net/br0/bridge/multicast_snooping
2. $ ip l set eth1 down
^ This step deletes the interface from the router list
3. $ ip l set eth1 up
^ This step does not add it again because mcast snooping is disabled
4. $ echo 1 > /sys/class/net/br0/bridge/multicast_snooping
5. $ bridge -d -s mdb show
<empty>

At this point we have mcast enabled and eth1 as a perm router (value = 2)
but it is not in the router list which is incorrect.

After this change:
1. $ echo 0 > /sys/class/net/br0/bridge/multicast_snooping
2. $ ip l set eth1 down
^ This step deletes the interface from the router list
3. $ ip l set eth1 up
^ This step does not add it again because mcast snooping is disabled
4. $ echo 1 > /sys/class/net/br0/bridge/multicast_snooping
5. $ bridge -d -s mdb show
router ports on br0: eth1

Note: we can directly do br_multicast_enable_port for all because the
querier timer already has checks for the port state and will simply
expire if it's in blocking/disabled. See the comment added by
commit 9aa66382 ("bridge: multicast: add a comment to
br_port_state_selection about blocking state")

Fixes: 561f1103 ("bridge: Add multicast_snooping sysfs toggle")
Reported-by: Satish Ashok <sashok@cumulusnetworks.com>
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit a2ed0b39 upstream.

When isofs_mount() is called to mount a device read-write, it returns
EACCES even before it checks that the device actually contains an isofs
filesystem. This may confuse mount(8) which then tries to mount all
subsequent filesystem types in read-only mode.

Fix the problem by returning EACCES only once we verify that the device
indeed contains an iso9660 filesystem.

Fixes: 17b7f7cfReported-by: Kent Overstreet <kent.overstreet@gmail.com>
Reported-by: Karel Zak <kzak@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 3ab7511e upstream.

Commit 49d9e77e ("ALSA: hda - Fix system panic when DMA > 40 bits
for Nvidia audio controllers") simply disabled any DMA exceeding 32
bits for NVidia devices, even though they are capable of performing
DMA up to 40 bits. On some architectures (such as arm64), system memory
is not guaranteed to be 32-bit addressable by PCI devices, and so this
change prevents NVidia devices from working on platforms such as AMD
Seattle.

Since the original commit already mentioned that up to 40 bits of DMA
is supported, and given that the code has been updated in the meantime
to support a 40 bit DMA mask on other devices, revert commit 49d9e77e
and explicitly set the DMA mask to 40 bits for NVidia devices.

Fixes: 49d9e77e ('ALSA: hda - Fix system panic when DMA > 40 bits...')
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 09525a09 upstream.

We don't want to allow negatives here.

Fixes: 36b701fa ('netfilter: nf_tables: validate maximum value of u32 netlink attributes')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 85054035 upstream.

Commit f436b2ac ("arm64: kernel: fix architected PMU registers
unconditional access") made sure we wouldn't access unimplemented
PMU registers, but also left MDCR_EL2 uninitialized in that case,
leading to trap bits being potentially left set.

Make sure we always write something in that register.

Fixes: f436b2ac ("arm64: kernel: fix architected PMU registers unconditional access")
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit ca006f78 upstream.

This adds support to ftdi_sio for the Infineon TriBoard TC2X7
engineering board for first-generation Aurix SoCs with Tricore CPUs.
Mere addition of the device IDs does the job.
Signed-off-by: Stefan Tauner <stefan.tauner@technikum-wien.at>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 9158cb29 upstream.

Accesses to the rtsx usb device, which is the parent of the rtsx memstick
device, must not be done unless it's runtime resumed. This is currently not
the case and it could trigger various errors.

Fix this by properly deal with runtime PM in this regards. This means
making sure the device is runtime resumed, when serving requests via the
->request() callback or changing settings via the ->set_param() callbacks.

Cc: Ritesh Raj Sarraf <rrs@researchut.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 796aa46a upstream.

Accesses to the rtsx usb device, which is the parent of the rtsx memstick
device, must not be done unless it's runtime resumed.

Therefore when the rtsx_usb_ms driver polls for inserted memstick cards,
let's add pm_runtime_get|put*() to make sure accesses is done when the
rtsx usb device is runtime resumed.
Reported-by: Ritesh Raj Sarraf <rrs@researchut.com>
Tested-by: Ritesh Raj Sarraf <rrs@researchut.com>
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 4f48aa7a upstream.

Accesses of the rtsx sdmmc's parent device, which is the rtsx usb device,
must be done when it's runtime resumed. Currently this isn't case when
changing the led, so let's fix this by adding a pm_runtime_get_sync() and
a pm_runtime_put() around those operations.
Reported-by: Ritesh Raj Sarraf <rrs@researchut.com>
Tested-by: Ritesh Raj Sarraf <rrs@researchut.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 31cf742f upstream.

The rtsx_usb_sdmmc driver may bail out in its ->set_ios() callback when no
SD card is inserted. This is wrong, as it could cause the device to remain
runtime resumed when it's unused. Fix this behaviour.
Tested-by: Ritesh Raj Sarraf <rrs@researchut.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 02265cd6 upstream.

Potentially overflowing expression 1000000 * data->timeout_clks with
type unsigned int is evaluated using 32-bit arithmetic, and then used
in a context that expects an expression of type unsigned long long.

To avoid overflow, cast 1000000U to type unsigned long long.
Special thanks to Coverity.

Fixes: 7f05538a ("mmc: sdhci: fix data timeout (part 2)")
Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit e7cb08e8 upstream.

We accidentally overwrite the original saved value of "flags" so that we
can't re-enable IRQs at the end of the function.  Presumably this
function is mostly called with IRQs disabled or it would be obvious in
testing.

Fixes: aceeffbb ("zfcp: trace full payload of all SAN records (req,resp,iels)")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit a220445f upstream.

The goal of the patch is to fix this scenario:
 ip link add dummy1 type dummy
 ip link set dummy1 up
 ip link set lo down ; ip link set lo up

After that sequence, the local route to the link layer address of dummy1 is
not there anymore.

When the loopback is set down, all local routes are deleted by
addrconf_ifdown()/rt6_ifdown(). At this time, the rt6_info entry still
exists, because the corresponding idev has a reference on it. After the rcu
grace period, dst_rcu_free() is called, and thus ___dst_free(), which will
set obsolete to DST_OBSOLETE_DEAD.

In this case, init_loopback() is called before dst_rcu_free(), thus
obsolete is still sets to something <= 0. So, the function doesn't add the
route again. To avoid that race, let's check the rt6 refcnt instead.

Fixes: 25fb6ca4 ("net IPv6 : Fix broken IPv6 routing table after loopback down-up")
Fixes: a881ae1f ("ipv6: don't call addrconf_dst_alloc again when enable lo")
Fixes: 33d99113 ("ipv6: reallocate addrconf router for ipv6 address when lo device up")
Reported-by: Francesco Santoro <francesco.santoro@6wind.com>
Reported-by: Samuel Gauthier <samuel.gauthier@6wind.com>
CC: Balakumaran Kannan <Balakumaran.Kannan@ap.sony.com>
CC: Maruthi Thotad <Maruthi.Thotad@ap.sony.com>
CC: Sabrina Dubroca <sd@queasysnail.net>
CC: Hannes Frederic Sowa <hannes@stressinduktion.org>
CC: Weilong Chen <chenweilong@huawei.com>
CC: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 02cfb5fc upstream.

Ported from Rex's amdgpu change.
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 559cce69 upstream.

When 'jh->b_transaction == transaction' (asserted by below)

  J_ASSERT_JH(jh, (jh->b_transaction == transaction || ...

'journal->j_list_lock' will be incorrectly unlocked, since
the the lock is aquired only at the end of if / else-if
statements (missing the else case).
Signed-off-by: Taesoo Kim <tsgatesv@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Fixes: 6e4862a5Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit ea720935 upstream.

In mac80211, multicast A-MSDUs are accepted in many cases that
they shouldn't be accepted in:
 * drop A-MSDUs with a multicast A1 (RA), as required by the
   spec in 9.11 (802.11-2012 version)
 * drop A-MSDUs with a 4-addr header, since the fourth address
   can't actually be useful for them; unless 4-address frame
   format is actually requested, even though the fourth address
   is still not useful in this case, but ignored

Accepting the first case, in particular, is very problematic
since it allows anyone else with possession of a GTK to send
unicast frames encapsulated in a multicast A-MSDU, even when
the AP has client isolation enabled.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit bcd8f2e9 upstream.

This patch fixes one use-after-free report[1] by KASAN.

In __scsi_scan_target(), when a type 31 device is probed,
SCSI_SCAN_TARGET_PRESENT is returned and the target will be scanned
again.

Inside the following scsi_report_lun_scan(), one new scsi_device
instance is allocated, and scsi_probe_and_add_lun() is called again to
probe the target and still see type 31 device, finally
__scsi_remove_device() is called to remove & free the device at the end
of scsi_probe_and_add_lun(), so cause use-after-free in
scsi_report_lun_scan().

And the following SCSI log can be observed:

	scsi 0:0:2:0: scsi scan: INQUIRY pass 1 length 36
	scsi 0:0:2:0: scsi scan: INQUIRY successful with code 0x0
	scsi 0:0:2:0: scsi scan: peripheral device type of 31, no device added
	scsi 0:0:2:0: scsi scan: Sending REPORT LUNS to (try 0)
	scsi 0:0:2:0: scsi scan: REPORT LUNS successful (try 0) result 0x0
	scsi 0:0:2:0: scsi scan: REPORT LUN scan
	scsi 0:0:2:0: scsi scan: INQUIRY pass 1 length 36
	scsi 0:0:2:0: scsi scan: INQUIRY successful with code 0x0
	scsi 0:0:2:0: scsi scan: peripheral device type of 31, no device added
	BUG: KASAN: use-after-free in __scsi_scan_target+0xbf8/0xe40 at addr ffff88007b44a104

This patch fixes the issue by moving the putting reference at
the end of scsi_report_lun_scan().

[1] KASAN report
==================================================================
[    3.274597] PM: Adding info for serio:serio1
[    3.275127] BUG: KASAN: use-after-free in __scsi_scan_target+0xd87/0xdf0 at addr ffff880254d8c304
[    3.275653] Read of size 4 by task kworker/u10:0/27
[    3.275903] CPU: 3 PID: 27 Comm: kworker/u10:0 Not tainted 4.8.0 #2121
[    3.276258] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
[    3.276797] Workqueue: events_unbound async_run_entry_fn
[    3.277083]  ffff880254d8c380 ffff880259a37870 ffffffff94bbc6c1 ffff880078402d80
[    3.277532]  ffff880254d8bb80 ffff880259a37898 ffffffff9459fec1 ffff880259a37930
[    3.277989]  ffff880254d8bb80 ffff880078402d80 ffff880259a37920 ffffffff945a0165
[    3.278436] Call Trace:
[    3.278528]  [<ffffffff94bbc6c1>] dump_stack+0x65/0x84
[    3.278797]  [<ffffffff9459fec1>] kasan_object_err+0x21/0x70
[    3.279063] device: 'psaux': device_add
[    3.279616]  [<ffffffff945a0165>] kasan_report_error+0x205/0x500
[    3.279651] PM: Adding info for No Bus:psaux
[    3.280202]  [<ffffffff944ecd22>] ? kfree_const+0x22/0x30
[    3.280486]  [<ffffffff94bc2dc9>] ? kobject_release+0x119/0x370
[    3.280805]  [<ffffffff945a0543>] __asan_report_load4_noabort+0x43/0x50
[    3.281170]  [<ffffffff9507e1f7>] ? __scsi_scan_target+0xd87/0xdf0
[    3.281506]  [<ffffffff9507e1f7>] __scsi_scan_target+0xd87/0xdf0
[    3.281848]  [<ffffffff9507d470>] ? scsi_add_device+0x30/0x30
[    3.282156]  [<ffffffff94f7f660>] ? pm_runtime_autosuspend_expiration+0x60/0x60
[    3.282570]  [<ffffffff956ddb07>] ? _raw_spin_lock+0x17/0x40
[    3.282880]  [<ffffffff9507e505>] scsi_scan_channel+0x105/0x160
[    3.283200]  [<ffffffff9507e8a2>] scsi_scan_host_selected+0x212/0x2f0
[    3.283563]  [<ffffffff9507eb3c>] do_scsi_scan_host+0x1bc/0x250
[    3.283882]  [<ffffffff9507efc1>] do_scan_async+0x41/0x450
[    3.284173]  [<ffffffff941c1fee>] async_run_entry_fn+0xfe/0x610
[    3.284492]  [<ffffffff941a8954>] ? pwq_dec_nr_in_flight+0x124/0x2a0
[    3.284876]  [<ffffffff941d1770>] ? preempt_count_add+0x130/0x160
[    3.285207]  [<ffffffff941a9a84>] process_one_work+0x544/0x12d0
[    3.285526]  [<ffffffff941aa8e9>] worker_thread+0xd9/0x12f0
[    3.285844]  [<ffffffff941aa810>] ? process_one_work+0x12d0/0x12d0
[    3.286182]  [<ffffffff941bb365>] kthread+0x1c5/0x260
[    3.286443]  [<ffffffff940855cd>] ? __switch_to+0x88d/0x1430
[    3.286745]  [<ffffffff941bb1a0>] ? kthread_worker_fn+0x5a0/0x5a0
[    3.287085]  [<ffffffff956dde9f>] ret_from_fork+0x1f/0x40
[    3.287368]  [<ffffffff941bb1a0>] ? kthread_worker_fn+0x5a0/0x5a0
[    3.287697] Object at ffff880254d8bb80, in cache kmalloc-2048 size: 2048
[    3.288064] Allocated:
[    3.288147] PID = 27
[    3.288218]  [<ffffffff940b27ab>] save_stack_trace+0x2b/0x50
[    3.288531]  [<ffffffff9459f246>] save_stack+0x46/0xd0
[    3.288806]  [<ffffffff9459f4bd>] kasan_kmalloc+0xad/0xe0
[    3.289098]  [<ffffffff9459c07e>] __kmalloc+0x13e/0x250
[    3.289378]  [<ffffffff95078e5a>] scsi_alloc_sdev+0xea/0xcf0
[    3.289701]  [<ffffffff9507de76>] __scsi_scan_target+0xa06/0xdf0
[    3.290034]  [<ffffffff9507e505>] scsi_scan_channel+0x105/0x160
[    3.290362]  [<ffffffff9507e8a2>] scsi_scan_host_selected+0x212/0x2f0
[    3.290724]  [<ffffffff9507eb3c>] do_scsi_scan_host+0x1bc/0x250
[    3.291055]  [<ffffffff9507efc1>] do_scan_async+0x41/0x450
[    3.291354]  [<ffffffff941c1fee>] async_run_entry_fn+0xfe/0x610
[    3.291695]  [<ffffffff941a9a84>] process_one_work+0x544/0x12d0
[    3.292022]  [<ffffffff941aa8e9>] worker_thread+0xd9/0x12f0
[    3.292325]  [<ffffffff941bb365>] kthread+0x1c5/0x260
[    3.292594]  [<ffffffff956dde9f>] ret_from_fork+0x1f/0x40
[    3.292886] Freed:
[    3.292945] PID = 27
[    3.293016]  [<ffffffff940b27ab>] save_stack_trace+0x2b/0x50
[    3.293327]  [<ffffffff9459f246>] save_stack+0x46/0xd0
[    3.293600]  [<ffffffff9459fa61>] kasan_slab_free+0x71/0xb0
[    3.293916]  [<ffffffff9459bac2>] kfree+0xa2/0x1f0
[    3.294168]  [<ffffffff9508158a>] scsi_device_dev_release_usercontext+0x50a/0x730
[    3.294598]  [<ffffffff941ace9a>] execute_in_process_context+0xda/0x130
[    3.294974]  [<ffffffff9508107c>] scsi_device_dev_release+0x1c/0x20
[    3.295322]  [<ffffffff94f566f6>] device_release+0x76/0x1e0
[    3.295626]  [<ffffffff94bc2db7>] kobject_release+0x107/0x370
[    3.295942]  [<ffffffff94bc29ce>] kobject_put+0x4e/0xa0
[    3.296222]  [<ffffffff94f56e17>] put_device+0x17/0x20
[    3.296497]  [<ffffffff9505201c>] scsi_device_put+0x7c/0xa0
[    3.296801]  [<ffffffff9507e1bc>] __scsi_scan_target+0xd4c/0xdf0
[    3.297132]  [<ffffffff9507e505>] scsi_scan_channel+0x105/0x160
[    3.297458]  [<ffffffff9507e8a2>] scsi_scan_host_selected+0x212/0x2f0
[    3.297829]  [<ffffffff9507eb3c>] do_scsi_scan_host+0x1bc/0x250
[    3.298156]  [<ffffffff9507efc1>] do_scan_async+0x41/0x450
[    3.298453]  [<ffffffff941c1fee>] async_run_entry_fn+0xfe/0x610
[    3.298777]  [<ffffffff941a9a84>] process_one_work+0x544/0x12d0
[    3.299105]  [<ffffffff941aa8e9>] worker_thread+0xd9/0x12f0
[    3.299408]  [<ffffffff941bb365>] kthread+0x1c5/0x260
[    3.299676]  [<ffffffff956dde9f>] ret_from_fork+0x1f/0x40
[    3.299967] Memory state around the buggy address:
[    3.300209]  ffff880254d8c200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[    3.300608]  ffff880254d8c280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[    3.300986] >ffff880254d8c300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[    3.301408]                    ^
[    3.301550]  ffff880254d8c380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[    3.301987]  ffff880254d8c400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[    3.302396]
==================================================================

Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit aa5f9209 upstream.

Mismatching stream names in DAPM route and widget definitions are
causing compilation errors. Fixing these names allows the cs4270
driver to compile and function.

[Errors must be at probe time not compile time -- broonie]
Signed-off-by: Murray Foster <mrafoster@gmail.com>
Acked-by: Paul Handrigan <Paul.Handrigan@cirrus.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 3f2d2664 upstream.

Commit f68381a7 (mmc: block: fix packed command header endianness)
correctly fixed endianness handling of packed_cmd_hdr in
mmc_blk_packed_hdr_wrq_prep.

But now, sparse complains about incorrect types:
drivers/mmc/card/block.c:1613:27: sparse: incorrect type in assignment (different base types)
drivers/mmc/card/block.c:1613:27:    expected unsigned int [unsigned] [usertype] <noident>
drivers/mmc/card/block.c:1613:27:    got restricted __le32 [usertype] <noident>
...

So annotate cmd_hdr properly using __le32 to make everyone happy.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Fixes: f68381a7 (mmc: block: fix packed command header endianness)
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 89f39af1 upstream.

Change thaw_super() to check frozen != SB_FREEZE_COMPLETE rather than
frozen == SB_UNFROZEN, otherwise it can race with freeze_super() which
drops sb->s_umount after SB_FREEZE_WRITE to preserve the lock ordering.

In this case thaw_super() will wrongly call s_op->unfreeze_fs() before
it was actually frozen, and call sb_freeze_unlock() which leads to the
unbalanced percpu_up_write(). Unfortunately lockdep can't detect this,
so this triggers misc BUG_ON()'s in kernel/rcu/sync.c.
Reported-and-tested-by: Nikolay Borisov <kernel@kyup.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 24df1483 upstream.

Cleanup some missing mem frees on some cifs ioctls, and
clarify others to make more obvious that no data is returned.
Signed-off-by: Steve French <smfrench@gmail.com>
Acked-by: Sachin Prabhu <sprabhu@redhat.com>
[bwh: Backported to 3.16:
 - Drop changes to smb2_duplicate_extents(), smb3_set_integrity()
 - Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 18dd8e1a upstream.

[CIFS] We had cases where we sent a SMB2/SMB3 setinfo request with all
timestamp (and DOS attribute) fields marked as 0 (ie do not change)
e.g. on chmod or chown.
Signed-off-by: Steve French <steve.french@primarydata.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 3afca265 upstream.

Remove the global file_list_lock to simplify cifs/smb3 locking and
have spinlocks that more closely match the information they are
protecting.

Add new tcon->open_file_lock and file->file_info_lock spinlocks.
Locks continue to follow a heirachy,
	cifs_socket --> cifs_ses --> cifs_tcon --> cifs_file
where global tcp_ses_lock still protects socket and cifs_ses, while the
the newer locks protect the lower level structure's information
(tcon and cifs_file respectively).
Signed-off-by: Steve French <steve.french@primarydata.com>
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Reviewed-by: Germano Percossi <germano.percossi@citrix.com>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit fa70b87c upstream.

GUIDs although random, and 16 bytes, need to be generated as
proper uuids.
Signed-off-by: Steve French <steve.french@primarydata.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Reported-by: David Goebels <davidgoe@microsoft.com>
[bwh: Backported to 3.16: drop changes to create_durable_v2_buf()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit c2afb814 upstream.
Signed-off-by: Steve French <steve.french@primarydata.com>
Reported-by: David Goebel <davidgoe@microsoft.com>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 7d414f39 upstream.

The kernel client requests 2 credits for many operations even though
they only use 1 credit (presumably to build up a buffer of credit).
Some servers seem to give the client as much credit as is requested.  In
this case, the amount of credit the client has continues increasing to
the point where (server->credits * MAX_BUFFER_SIZE) overflows in
smb2_wait_mtu_credits().

Fix this by throttling the credit requests if an set limit is reached.
For async requests where the credit charge may be > 1, request as much
credit as what is charged.
The limit is chosen somewhat arbitrarily. The Windows client
defaults to 128 credits, the Windows server allows clients up to
512 credits (or 8192 for Windows 2016), and the NetApp server
(and at least one other) does not limit clients at all.
Choose a high enough value such that the client shouldn't limit
performance.

This behavior was seen with a NetApp filer (NetApp Release 9.0RC2).
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Signed-off-by: Steve French <smfrench@gmail.com>
[bwh: Backported to 3.16: drop changes to smb2_async_{read,write}v()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 9742805d upstream.

In debugging smb3, it is useful to display the number
of credits available, so we can see when the server has not granted
sufficient operations for the client to make progress, or alternatively
the client has requested too many credits (as we saw in a recent bug)
so we can compare with the number of credits the server thinks
we have.

Add a /proc/fs/cifs/DebugData line to display the client view
on how many credits are available.
Signed-off-by: Steve French <steve.french@primarydata.com>
Reported-by: Germano Percossi <germano.percossi@citrix.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 74f1077b upstream.

Currently regs_return_value always negates reg[2] if it determines
the syscall has failed, but when called in kernel context this check is
invalid and may result in returning a wrong value.

This fixes errors reported by CONFIG_KPROBES_SANITY_TEST

Fixes: d7e7528b ("Audit: push audit success and retcode into arch ptrace.h")
Signed-off-by: Marcin Nowakowski <marcin.nowakowski@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14381/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 5864a2fd upstream.

Commit 6d07b68c ("ipc/sem.c: optimize sem_lock()") introduced a
race:

sem_lock has a fast path that allows parallel simple operations.
There are two reasons why a simple operation cannot run in parallel:
 - a non-simple operations is ongoing (sma->sem_perm.lock held)
 - a complex operation is sleeping (sma->complex_count != 0)

As both facts are stored independently, a thread can bypass the current
checks by sleeping in the right positions.  See below for more details
(or kernel bugzilla 105651).

The patch fixes that by creating one variable (complex_mode)
that tracks both reasons why parallel operations are not possible.

The patch also updates stale documentation regarding the locking.

With regards to stable kernels:
The patch is required for all kernels that include the
commit 6d07b68c ("ipc/sem.c: optimize sem_lock()") (3.10?)

The alternative is to revert the patch that introduced the race.

The patch is safe for backporting, i.e. it makes no assumptions
about memory barriers in spin_unlock_wait().

Background:
Here is the race of the current implementation:

Thread A: (simple op)
- does the first "sma->complex_count == 0" test

Thread B: (complex op)
- does sem_lock(): This includes an array scan. But the scan can't
  find Thread A, because Thread A does not own sem->lock yet.
- the thread does the operation, increases complex_count,
  drops sem_lock, sleeps

Thread A:
- spin_lock(&sem->lock), spin_is_locked(sma->sem_perm.lock)
- sleeps before the complex_count test

Thread C: (complex op)
- does sem_lock (no array scan, complex_count==1)
- wakes up Thread B.
- decrements complex_count

Thread A:
- does the complex_count test

Bug:
Now both thread A and thread C operate on the same array, without
any synchronization.

Fixes: 6d07b68c ("ipc/sem.c: optimize sem_lock()")
Link: http://lkml.kernel.org/r/1469123695-5661-1-git-send-email-manfred@colorfullife.com
Reported-by: <felixh@informatik.uni-bremen.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: <1vier1@web.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[bwh: Backported to 3.16:
 - We missed out on some earlier memory barrier changes
 - Use set_mb instead of smp_store_mb]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 7f032d6e upstream.

The seq_printf return value, because it's frequently misused,
will eventually be converted to void.

See: commit 1f33c41c ("seq_file: Rename seq_overflow() to
     seq_has_overflowed() and make public")
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 536fa402 upstream.

CPUs without single-byte and double-byte loads and stores place some
"interesting" requirements on concurrent code.  For example (adapted
from Peter Hurley's test code), suppose we have the following structure:

	struct foo {
		spinlock_t lock1;
		spinlock_t lock2;
		char a; /* Protected by lock1. */
		char b; /* Protected by lock2. */
	};
	struct foo *foop;

Of course, it is common (and good) practice to place data protected
by different locks in separate cache lines.  However, if the locks are
rarely acquired (for example, only in rare error cases), and there are
a great many instances of the data structure, then memory footprint can
trump false-sharing concerns, so that it can be better to place them in
the same cache cache line as above.

But if the CPU does not support single-byte loads and stores, a store
to foop->a will do a non-atomic read-modify-write operation on foop->b,
which will come as a nasty surprise to someone holding foop->lock2.  So we
now require CPUs to support single-byte and double-byte loads and stores.
Therefore, this commit adjusts the definition of __native_word() to allow
these sizes to be used by smp_load_acquire() and smp_store_release().
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 54c721b8 upstream.

Daniel Walker reported problems which happens when
crash_kexec_post_notifiers kernel option is enabled
(https://lkml.org/lkml/2015/6/24/44).

In that case, smp_send_stop() is called before entering kdump routines
which assume other CPUs are still online.  As the result, kdump
routines fail to save other CPUs' registers.  Additionally for MIPS
OCTEON, it misses to stop the watchdog timer.

To fix this problem, call a new kdump friendly function,
crash_smp_send_stop(), instead of the smp_send_stop() when
crash_kexec_post_notifiers is enabled.  crash_smp_send_stop() is a
weak function, and it just call smp_send_stop().  Architecture
codes should override it so that kdump can work appropriately.
This patch provides MIPS version.

Fixes: f06e5153 (kernel/panic.c: add "crash_kexec_post_notifiers" option)
Link: http://lkml.kernel.org/r/20160810080950.11028.28000.stgit@sysi4-13.yrl.intra.hitachi.co.jpSigned-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Reported-by: Daniel Walker <dwalker@fifo99.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Daniel Walker <dwalker@fifo99.com>
Cc: Xunlei Pang <xpang@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: David Daney <david.daney@cavium.com>
Cc: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: "Steven J. Hill" <steven.hill@cavium.com>
Cc: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 0ee59413 upstream.

Daniel Walker reported problems which happens when
crash_kexec_post_notifiers kernel option is enabled
(https://lkml.org/lkml/2015/6/24/44).

In that case, smp_send_stop() is called before entering kdump routines
which assume other CPUs are still online.  As the result, for x86, kdump
routines fail to save other CPUs' registers and disable virtualization
extensions.

To fix this problem, call a new kdump friendly function,
crash_smp_send_stop(), instead of the smp_send_stop() when
crash_kexec_post_notifiers is enabled.  crash_smp_send_stop() is a weak
function, and it just call smp_send_stop().  Architecture codes should
override it so that kdump can work appropriately.  This patch only
provides x86-specific version.

For Xen's PV kernel, just keep the current behavior.

NOTES:

- Right solution would be to place crash_smp_send_stop() before
  __crash_kexec() invocation in all cases and remove smp_send_stop(), but
  we can't do that until all architectures implement own
  crash_smp_send_stop()

- crash_smp_send_stop()-like work is still needed by
  machine_crash_shutdown() because crash_kexec() can be called without
  entering panic()

Fixes: f06e5153 (kernel/panic.c: add "crash_kexec_post_notifiers" option)
Link: http://lkml.kernel.org/r/20160810080948.11028.15344.stgit@sysi4-13.yrl.intra.hitachi.co.jpSigned-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Reported-by: Daniel Walker <dwalker@fifo99.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Daniel Walker <dwalker@fifo99.com>
Cc: Xunlei Pang <xpang@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: David Daney <david.daney@cavium.com>
Cc: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: "Steven J. Hill" <steven.hill@cavium.com>
Cc: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 1a34439e upstream.

Debugging a data corruption issue with virtio-net/vhost-net led to
the observation that __copy_tofrom_user was occasionally returning
a value 16 larger than it should.  Since the return value from
__copy_tofrom_user is the number of bytes not copied, this means
that __copy_tofrom_user can occasionally return a value larger
than the number of bytes it was asked to copy.  In turn this can
cause higher-level copy functions such as copy_page_to_iter_iovec
to corrupt memory by copying data into the wrong memory locations.

It turns out that the failing case involves a fault on the store
at label 79, and at that point the first unmodified byte of the
destination is at R3 + 16.  Consequently the exception handler
for that store needs to add 16 to R3 before using it to work out
how many bytes were not copied, but in this one case it was not
adding the offset to R3.  To fix it, this moves the label 179 to
the point where we add 16 to R3.  I have checked manually all the
exception handlers for the loads and stores in this code and the
rest of them are correct (it would be excellent to have an
automated test of all the exception cases).

This bug has been present since this code was initially
committed in May 2002 to Linux version 2.5.20.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 05af40e8 upstream.

This commit fixes a stack corruption in the pseries specific code dealing
with the huge pages.

In __pSeries_lpar_hugepage_invalidate() the buffer used to pass arguments
to the hypervisor is not large enough. This leads to a stack corruption
where a previously saved register could be corrupted leading to unexpected
result in the caller, like the following panic:

  Oops: Kernel access of bad area, sig: 11 [#1]
  SMP NR_CPUS=2048 NUMA pSeries
  Modules linked in: virtio_balloon ip_tables x_tables autofs4
  virtio_blk 8139too virtio_pci virtio_ring 8139cp virtio
  CPU: 11 PID: 1916 Comm: mmstress Not tainted 4.8.0 #76
  task: c000000005394880 task.stack: c000000005570000
  NIP: c00000000027bf6c LR: c00000000027bf64 CTR: 0000000000000000
  REGS: c000000005573820 TRAP: 0300   Not tainted  (4.8.0)
  MSR: 8000000000009033 <SF,EE,ME,IR,DR,RI,LE>  CR: 84822884  XER: 20000000
  CFAR: c00000000010a924 DAR: 420000000014e5e0 DSISR: 40000000 SOFTE: 1
  GPR00: c00000000027bf64 c000000005573aa0 c000000000e02800 c000000004447964
  GPR04: c00000000404de18 c000000004d38810 00000000042100f5 00000000f5002104
  GPR08: e0000000f5002104 0000000000000001 042100f5000000e0 00000000042100f5
  GPR12: 0000000000002200 c00000000fe02c00 c00000000404de18 0000000000000000
  GPR16: c1ffffffffffe7ff 00003fff62000000 420000000014e5e0 00003fff63000000
  GPR20: 0008000000000000 c0000000f7014800 0405e600000000e0 0000000000010000
  GPR24: c000000004d38810 c000000004447c10 c00000000404de18 c000000004447964
  GPR28: c000000005573b10 c000000004d38810 00003fff62000000 420000000014e5e0
  NIP [c00000000027bf6c] zap_huge_pmd+0x4c/0x470
  LR [c00000000027bf64] zap_huge_pmd+0x44/0x470
  Call Trace:
  [c000000005573aa0] [c00000000027bf64] zap_huge_pmd+0x44/0x470 (unreliable)
  [c000000005573af0] [c00000000022bbd8] unmap_page_range+0xcf8/0xed0
  [c000000005573c30] [c00000000022c2d4] unmap_vmas+0x84/0x120
  [c000000005573c80] [c000000000235448] unmap_region+0xd8/0x1b0
  [c000000005573d80] [c0000000002378f0] do_munmap+0x2d0/0x4c0
  [c000000005573df0] [c000000000237be4] SyS_munmap+0x64/0xb0
  [c000000005573e30] [c000000000009560] system_call+0x38/0x108
  Instruction dump:
  fbe1fff8 fb81ffe0 7c7f1b78 7ca32b78 7cbd2b78 f8010010 7c9a2378 f821ffb1
  7cde3378 4bfffea9 7c7b1b79 41820298 <e87f0000> 48000130 7fa5eb78 7fc4f378

Most of the time, the bug is surfacing in a caller up in the stack from
__pSeries_lpar_hugepage_invalidate() which is quite confusing.

This bug is pending since v3.11 but was hidden if a caller of the
caller of __pSeries_lpar_hugepage_invalidate() has pushed the corruped
register (r18 in this case) in the stack and is not using it until
restoring it. GCC 6.2.0 seems to raise it more frequently.

This commit also change the definition of the parameter buffer in
pSeries_lpar_flush_hash_range() to rely on the global define
PLPAR_HCALL9_BUFSIZE (no functional change here).

Fixes: 1a527286 ("powerpc: Optimize hugepage invalidate")
Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit c2a9737f upstream.

We triggered a deadloop in truncate_inode_pages_range() on 32 bits
architecture with the test case bellow:

	...
	fd = open();
	write(fd, buf, 4096);
	preadv64(fd, &iovec, 1, 0xffffffff000);
	ftruncate(fd, 0);
	...

Then ftruncate() will not return forever.

The filesystem used in this case is ubifs, but it can be triggered on
many other filesystems.

When preadv64() is called with offset=0xffffffff000, a page with
index=0xffffffff will be added to the radix tree of ->mapping.  Then
this page can be found in ->mapping with pagevec_lookup().  After that,
truncate_inode_pages_range(), which is called in ftruncate(), will fall
into an infinite loop:

 - find a page with index=0xffffffff, since index>=end, this page won't
   be truncated

 - index++, and index become 0

 - the page with index=0xffffffff will be found again

The data type of index is unsigned long, so index won't overflow to 0 on
64 bits architecture in this case, and the dead loop won't happen.

Since truncate_inode_pages_range() is executed with holding lock of
inode->i_rwsem, any operation related with this lock will be blocked,
and a hung task will happen, e.g.:

  INFO: task truncate_test:3364 blocked for more than 120 seconds.
  ...
     call_rwsem_down_write_failed+0x17/0x30
     generic_file_write_iter+0x32/0x1c0
     ubifs_write_iter+0xcc/0x170
     __vfs_write+0xc4/0x120
     vfs_write+0xb2/0x1b0
     SyS_write+0x46/0xa0

The page with index=0xffffffff added to ->mapping is useless.  Fix this
by checking the read position before allocating pages.

Link: http://lkml.kernel.org/r/1475151010-40166-1-git-send-email-fangwei1@huawei.comSigned-off-by: Wei Fang <fangwei1@huawei.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 082d5b6b upstream.

In dissolve_free_huge_pages(), free hugepages will be dissolved without
making sure that there are enough of them left to satisfy hugepage
reservations.

Fix this by adding a return value to dissolve_free_huge_pages() and
checking h->free_huge_pages vs.  h->resv_huge_pages.  Note that this may
lead to the situation where dissolve_free_huge_page() returns an error
and all free hugepages that were dissolved before that error are lost,
while the memory block still cannot be set offline.

Fixes: c8721bbb ("mm: memory-hotplug: enable memory hotplug to handle hugepage")
Link: http://lkml.kernel.org/r/20160926172811.94033-3-gerald.schaefer@de.ibm.comSigned-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Rui Teng <rui.teng@linux.vnet.ibm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 2247bb33 upstream.

Patch series "mm/hugetlb: memory offline issues with hugepages", v4.

This addresses several issues with hugepages and memory offline.  While
the first patch fixes a panic, and is therefore rather important, the
last patch is just a performance optimization.

The second patch fixes a theoretical issue with reserved hugepages,
while still leaving some ugly usability issue, see description.

This patch (of 3):

dissolve_free_huge_pages() will either run into the VM_BUG_ON() or a
list corruption and addressing exception when trying to set a memory
block offline that is part (but not the first part) of a "gigantic"
hugetlb page with a size > memory block size.

When no other smaller hugetlb page sizes are present, the VM_BUG_ON()
will trigger directly.  In the other case we will run into an addressing
exception later, because dissolve_free_huge_page() will not work on the
head page of the compound hugetlb page which will result in a NULL
hstate from page_hstate().

To fix this, first remove the VM_BUG_ON() because it is wrong, and then
use the compound head page in dissolve_free_huge_page().  This means
that an unused pre-allocated gigantic page that has any part of itself
inside the memory block that is going offline will be dissolved
completely.  Losing an unused gigantic hugepage is preferable to failing
the memory offline, for example in the situation where a (possibly
faulty) memory DIMM needs to go offline.

Fixes: c8721bbb ("mm: memory-hotplug: enable memory hotplug to handle hugepage")
Link: http://lkml.kernel.org/r/20160926172811.94033-2-gerald.schaefer@de.ibm.comSigned-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Rui Teng <rui.teng@linux.vnet.ibm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>